CN107148350B - Laminated film coil and method for producing same - Google Patents

Laminated film coil and method for producing same Download PDF

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Publication number
CN107148350B
CN107148350B CN201580071024.9A CN201580071024A CN107148350B CN 107148350 B CN107148350 B CN 107148350B CN 201580071024 A CN201580071024 A CN 201580071024A CN 107148350 B CN107148350 B CN 107148350B
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refractive index
index layer
ultra
low refractive
present
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CN107148350A (en
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春田裕宗
武本博之
服部大辅
中村恒三
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Nitto Denko Corp
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Nitto Denko Corp
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D7/00—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials
    • B05D7/24—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials for applying particular liquids or other fluent materials
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J7/00—Chemical treatment or coating of shaped articles made of macromolecular substances
    • C08J7/04—Coating
    • C08J7/043—Improving the adhesiveness of the coatings per se, e.g. forming primers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B37/00—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding
    • B32B37/14—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the properties of the layers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
    • B32B5/18—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by features of a layer of foamed material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
    • B32B7/02—Physical, chemical or physicochemical properties
    • B32B7/023—Optical properties
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J7/00—Chemical treatment or coating of shaped articles made of macromolecular substances
    • C08J7/04—Coating
    • C08J7/0427—Coating with only one layer of a composition containing a polymer binder
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J7/00—Chemical treatment or coating of shaped articles made of macromolecular substances
    • C08J7/04—Coating
    • C08J7/046—Forming abrasion-resistant coatings; Forming surface-hardening coatings
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
    • G02B1/10—Optical coatings produced by application to, or surface treatment of, optical elements
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
    • G02B1/10—Optical coatings produced by application to, or surface treatment of, optical elements
    • G02B1/11—Anti-reflection coatings
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2551/00—Optical elements
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2483/00—Characterised by the use of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen, or carbon only; Derivatives of such polymers
    • C08J2483/04—Polysiloxanes

Abstract

The object of the present invention is to provide a novel member that can replace an air layer and exhibits low refractivity, for example. The laminated film coil of the present invention is a long laminated film coil obtained by laminating an ultra-low refractive index layer having a refractive index of 1.20 or less on a resin film. The method for manufacturing a long laminated film roll according to the present invention includes, for example, the steps of: a step of preparing a liquid containing fine-pore particles; coating the resin film with the liquid; and a step of drying the applied liquid.

Description

Laminated film coil and method for producing same
Technical Field
The present invention relates to a laminated film roll and a method for manufacturing the same.
Background
When 2 substrates are arranged with a constant gap, the gap between the two substrates becomes an air layer. In this manner, the air layer formed between the substrates functions as, for example, a low refractive layer that totally reflects light. Therefore, in the case of an optical film, for example, a prism, a polarizing film, a polarizing plate, and other members are arranged at a predetermined distance from each other, and an air layer serving as a low refractive index layer is provided between the members. However, since the members must be arranged at a certain distance to form the air layer, the members cannot be stacked one on another, which requires a lot of time and effort in manufacturing.
In order to solve such a problem, attempts are being made to develop a member such as a film exhibiting low refractivity, instead of an air layer formed by a gap between members. As an example of the above members, there is an application example of a reflection layer for an anti-lens as an example of the member having both high porosity and strength (for example, refer to patent documents 1 to 4). This method is a method in which after a void layer is formed on a lens, the lens is baked at a high temperature of 150 ℃ or higher for a long time, but the obtained void layer has poor flexibility and thus cannot be formed on a flexible resin film, and there is a problem in that continuous production in a roll cannot be performed. On the other hand, there is an application example of a void layer in which a firing process is not performed (for example, see non-patent document 1). However, this method has a problem that impact resistance cannot be imparted because the film strength of the obtained void layer is poor, and continuous production in a roll cannot be carried out.
Further, there is disclosed an example of a method for forming a silicone-oxygen gel film on a long resin support (see, for example, patent documents 5 and 6). However, the refractive index of the silica aerogel film obtained here exceeds 1.30, and therefore, the film cannot replace the air layer.
Documents of the prior art
Patent document
Patent document 1: japanese laid-open patent publication No. 2006-297329
Patent document 2: japanese laid-open patent application No. 2006-221144
Patent document 3: japanese patent laid-open No. 2006 and 011175
Patent document 4: japanese patent laid-open No. 2008-040171
Patent document 5: japanese laid-open patent publication No. 2006-096019
Patent document 6: japanese patent laid-open publication No. 2006 and 096967
Non-patent document
Non-patent document 1: mate chem, 2011,21,14830-
Disclosure of Invention
Problems to be solved by the invention
There has been no report of a long laminated film roll containing an ultra-low refractive index layer, which can achieve both flexibility and film strength and can be continuously produced in a roll. Accordingly, an object of the present invention is to provide a long laminated film roll including, for example, an ultra-low refractive index layer having a refractive index of 1.20 or less which can be a substitute for an air layer.
Means for solving the problems
In order to achieve the above object, a laminated film roll according to the present invention is characterized in that an ultra-low refractive index layer having a refractive index of 1.20 or less is laminated on a resin film.
The laminated film of the present invention is characterized in that an ultra-low refractive index layer having a refractive index of 1.20 or less is laminated on a resin film, and the ultra-low refractive index layer has a scratch resistance of 60 to 100% by Bemcot (registered trademark) which indicates the film strength, and a folding endurance of 100 times or more by MIT test which indicates the flexibility.
The method for manufacturing a laminated film roll according to the present invention includes the steps of: a step of preparing a liquid containing one or more constituent units forming a fine pore structure; coating the liquid on a resin film; and a step of drying the applied liquid.
The optical member of the present invention is characterized by containing the above-described laminated film coil or the ultralow refractive index layer in the laminated film of the present invention.
Effects of the invention
The laminated film coil of the present invention can realize, for example, an ultralow refractive index of 1.20 or less which can be substituted for an air layer by exhibiting the above-described characteristics, and can be continuously produced in a roll form. Therefore, it is not necessary to provide an air layer by disposing a plurality of members at a certain distance in order to obtain an ultra-low refractive index, and the ultra-low refractive index layer of the present invention can be disposed at a desired position to impart an ultra-low refractive index property, and continuous production at low cost can be realized. Therefore, the laminated film roll of the present invention is very useful for an optical member or the like requiring an ultra-low refractive index, for example.
Drawings
Fig. 1 is a process cross-sectional view schematically showing an example of a method for forming an ultra-low refractive index layer 20 on a resin film 10 in the present invention.
Fig. 2 is a view schematically showing an example of a part of the steps in the method for producing a laminated film roll of the present invention and an apparatus used in the method.
Fig. 3 is a view schematically showing a part of the steps in the method for producing a laminated film roll of the present invention and another example of an apparatus used in the method.
Fig. 4 is a process cross-sectional view schematically showing another example of the method for forming an ultra-low refractive index layer on a substrate in the present invention.
Fig. 5 is a view schematically showing a part of the steps in the method for producing an ultralow refractive index layer according to the present invention and yet another example of an apparatus used in the method.
Fig. 6 is a view schematically showing a part of the steps in the method for producing an ultra-low refractive index layer according to the present invention and yet another example of an apparatus used in the method.
Fig. 7 is a process cross-sectional view schematically showing still another example of the method for forming an ultra-low refractive index layer on a substrate in the present invention.
Fig. 8 is a view schematically showing a part of the steps in the method for producing an ultra-low refractive index layer according to the present invention and yet another example of an apparatus used in the method.
Fig. 9 is a view schematically showing a part of the steps in the method for producing an ultra-low refractive index layer according to the present invention and yet another example of an apparatus used in the method.
Detailed Description
In the ultra-low refractive index layer, for example, the multilayer film coil of the present invention has a scratch resistance of 60 to 100% by a Bemcot (registered trademark) indicating the film strength, and a folding endurance of 100 or more by an MIT test indicating flexibility.
In the laminated film roll of the present invention, for example, one or more kinds of constituent units forming a fine void structure in the ultra-low refractive index layer may be chemically bonded to each other. The constituent units may contain, for example, a direct bond or an indirect bond. Further, in the above-mentioned ultralow refractive index layer of the laminated film roll of the present invention, the above-mentioned one or more kinds of constituent units may be chemically bonded to each other, for example, at least partially. Specifically, for example, there may be a portion where the constituent units are not chemically bonded even when they are in contact with each other. In the present invention, "indirectly bonding" the constituent units to each other means that the constituent units are bonded to each other with a small amount of an adhesive component equal to or less than the amount of the constituent units. The "direct bonding" of the constituent units to each other means that the constituent units are directly bonded to each other without interposing a binder component or the like.
In the ultra-low refractive index layer of the laminated film roll of the present invention, for example, the bonding of the constituent units may include a hydrogen bond or a covalent bond. The constituent unit may be configured to have at least one shape selected from a particle shape, a fiber shape, and a flat plate shape, for example. The particulate and flat plate-like constituent elements may be made of an inorganic material, for example. The constituent element of the particulate constituent unit may contain at least one element selected from the group consisting of Si, Mg, Al, Ti, Zn, and Zr, for example. The particulate structure (constituent unit) may be a solid particle or a hollow particle, and specifically, a silicone particle or a silicone particle having a fine pore, a silica hollow nanoparticle or a silica hollow nanosphere (nanoballoon), or the like can be mentioned. The fibrous constituent unit is, for example, a nanofiber having a diameter of nanometer, and specific examples thereof include a cellulose nanofiber, an alumina nanofiber and the like. Examples of the tabular constituent unit include nanoclay, specifically, nano-sized bentonite (e.g., Kunipia F (trade name)), and the like. The fibrous constituent unit is not particularly limited, and may be at least one fibrous material selected from the group consisting of carbon nanofibers, cellulose nanofibers, alumina nanofibers, chitin nanofibers, chitosan nanofibers, polymer nanofibers, glass nanofibers, and silica nanofibers, for example.
The laminated film coil of the present invention is, for example, a porous body in which the ultra-low refractive index layer contains fine-pore particles. In the present invention, the shape of the "particle" (for example, the fine pore particle) is not particularly limited, and may be, for example, a spherical shape or a non-spherical shape. In the present invention, the fine-pore particles may be sol-gel beads, nanoparticles (hollow nano-silica/nano-sphere particles), nanofibers, or the like, for example, as described above.
In the laminated film roll of the present invention, for example, the ultralow refractive index layer has a porosity of 40% or more.
In the laminated film coil of the present invention, for example, the size of the voids of the holes is 2 to 200 nm.
The laminated film roll of the present invention has a thickness of, for example, 0.01 to 100 μm.
In the laminated film roll of the present invention, the haze indicating transparency is, for example, less than 5%.
The method for producing a laminated film roll according to the present invention further includes, for example, a step of adding a catalyst for chemically bonding the fine-pore particles to the liquid in the step of producing the liquid.
In the method for producing a laminated film roll of the present invention, for example, the catalyst is a catalyst that promotes crosslinking and bonding of fine pore particles.
In the method for manufacturing a laminated film roll according to the present invention, the ultra-low refractive index layer is formed by directly bonding the constituent units to each other, for example.
In the method for manufacturing a laminated film roll according to the present invention, the ultra-low refractive index layer is formed by, for example, indirectly bonding the constituent units to each other.
In the method for producing a laminated film roll of the present invention, the ultra-low refractive index layer is formed such that, for example, the bonding of the constituent units contains a hydrogen bond or a covalent bond.
In the method for producing a laminated film roll according to the present invention, for example, the constituent unit is a constituent unit having at least one shape selected from the group consisting of a particle shape, a fiber shape, and a flat plate shape. The particulate and flat plate-like constituent elements may be made of an inorganic material, for example. For example, the constituent elements of the particulate constituent unit may contain at least one element selected from the group consisting of Si, Mg, Al, Ti, Zn, and Zr. The constituent elements may be fine-pore particles, for example.
The present invention will be described in more detail below by way of examples. However, the present invention is not limited to the following description.
[1. laminated film roll ]
As described above, the laminated film roll of the present invention is obtained by laminating the ultra-low refractive index layer having a refractive index of 1.20 or less on the resin film. Alternatively, the present invention may be replaced with a laminated film in which an ultra-low refractive index layer having a refractive index of 1.20 or less is laminated on a resin film as described above, and the scratch resistance of the laminated film obtained by a Bemcot (registered trademark) indicating the film strength is 60 to 100%, and the number of times of folding resistance of the laminated film obtained by an MIT test indicating flexibility is 100 or more.
The resin film is not particularly limited, and examples of the resin include thermoplastic resins having excellent transparency such as polyethylene terephthalate (PET), acrylic acid, Cellulose Acetate Propionate (CAP), cycloolefin polymer (COP), Triacetate (TAC), polyethylene naphthalate (PEN), Polyethylene (PE), and polypropylene (PP).
The ultralow refractive index layer (hereinafter also referred to as "ultralow refractive index layer of the present invention") in the laminated film roll or the laminated film of the present invention may be directly laminated on the resin film, or may be laminated on the resin film via another layer, for example.
When the ultralow refractive index layer of the present invention is formed on the resin film, for example, the present invention may be referred to as a low refractive material which contains the ultralow refractive index layer and the resin film, and in which the ultralow refractive index layer is laminated on the resin film and has the above-described characteristics.
As described above, the ultralow refractive index layer of the present invention has a scratch resistance of 60 to 100% as measured by Bemcot (registered trademark), which indicates the film strength. The present invention has such film strength, and therefore can withstand physical impact during winding or use during production. The lower limit of the scratch resistance is, for example, 60% or more, 80% or more, and 90% or more, and the upper limit thereof is, for example, 100% or less, 99% or less, and 98% or less, and ranges from 60 to 100%, 80 to 99%, and 90 to 98%, for example.
In the laminated film coil or the laminated film of the present invention, for example, in the ultra-low refractive index layer, the scratch resistance obtained by Bemcot (registered trademark) indicating the film strength is 60 to 100%, and the number of times of bending resistance obtained by MIT test indicating flexibility is 100 or more. The scratch resistance can be measured by the following method, for example, when the ultra-low refractive index layer contains silicon (Si). When the ultra-low refractive index layer contains an element other than silicon (Si), the measurement can be performed, for example, by the following method.
(evaluation of scratch resistance)
(1) The void layer (ultra-low refractive index layer of the present invention) coated and formed on the acrylic film was sampled in a circular shape having a diameter of about 15 mm.
(2) Next, the silicon was identified by fluorescent X-ray (ZSXPrimusII, manufactured by Shimadzu corporation) with respect to the above-mentioned sample to determine the Si coating amount (Si coating amount)0). Next, the void layer on the acrylic film was cut into 50mm × 100mm from the vicinity of the sampling, fixed to a glass plate (thickness: 3mm), and then subjected to a sliding test by Bemcot (registered trademark). The sliding condition was set to 100g of weight and 10 reciprocations.
(3) The amount of Si remaining (Si remaining) after the scratch test was measured by sampling and fluorescence X measurement from the sliding-completed void layer in the same manner as in the above (1)1). The scratch resistance is defined as the residual Si ratio (%) before and after the sliding test by Bemcot (registered trademark), and can be represented by the following formula.
Scratch resistance (%) ([ amount of remaining Si (Si))1) Amount of Si applied (Si)0)]×100(％)
As described above, the ultra-low refractive index layer of the present invention has a folding endurance number of 100 or more, which is obtained by an MIT test and shows flexibility. The present invention has such flexibility, and therefore, has excellent handling properties during winding or use in continuous production.
The folding endurance is not particularly limited at its lower limit, for example, 100 times or more, 500 times or more, 1000 times or more, and at its upper limit, for example, 10000 times or less, and ranges, for example, from 100 to 10000 times, from 500 to 10000 times, and from 1000 to 10000 times.
The flexibility refers to, for example, the ease of deformation of the material. The number of folding endurance tests obtained by the MIT test can be measured by the following method, for example.
(evaluation of folding endurance test)
The above-mentioned void layer (ultra-low refractive index layer of the present invention) was cut into a 20mm × 80mm strip, and then mounted on an MIT bending resistance TESTER (manufactured by TESTER SANGYO corporation: BE-202), and a load of 1.0N was applied. The collet part enclosing the above-mentioned void layer was used at R2.0mm, and the folding endurance was conducted at most 10000 times, and the number of times at the time point when the above-mentioned void layer was broken was regarded as the folding endurance.
In the ultra-low refractive index layer of the present invention, the film density is not particularly limited, and the lower limit thereof is, for example, 1g/cm3Above, 10g/cm3Above, 15g/cm3Above, its upper limit is, for example, 50g/cm3Below, 40g/cm3Below, 30g/cm32.1g/cm below3The range of the amount is, for example, 5 to 50g/cm3、10～40g/cm3、15～30g/cm3、1～2.1g/cm3. In the ultra-low refractive index layer of the present invention, the lower limit of the porosity based on the film density is, for example, 50% or more, 70% or more, and 85% or more, and the upper limit thereof is, for example, 98% or less and 95% or less, and ranges from, for example, 50 to 98%, 70 to 95%, and 85 to 95%.
The film density can be measured, for example, by the following method, and the porosity can be calculated, for example, as follows based on the film density.
(evaluation of film Density and porosity)
After a void layer (the ultra-low refractive index layer of the present invention) was formed on a substrate (acrylic film), the X-ray reflectance of the total reflection region was measured with respect to the void layer in the laminate by using an X-ray diffraction apparatus (manufactured by RIGAKU corporation: RINT-2000). Then, after the Intensity and 2 θ were fitted, the film density (g/cm) was calculated from the critical angle of total reflection of the laminate (void layer/substrate)3) Further, the porosity (P%) was calculated by the following equation.
The porosity (P%) -45.48 times the film density (g/cm)3)+100(％)
The ultra-low refractive index layer of the present invention has a pore structure, and the pore size of the pores refers to the diameter of the long axis out of the diameter of the long axis and the diameter of the short axis of the pores (pores). The preferred pore size is, for example, 2nm to 500 nm. The lower limit of the above-mentioned void size is, for example, 2nm or more, 5nm or more, 10nm or more, and 20nm or more, and the upper limit thereof is, for example, 500nm or less, 200nm or less, and 100nm or less, and the ranges thereof are, for example, 2nm to 500nm, 5nm to 500nm, 10nm to 200nm, and 20nm to 100 nm. Since the preferable void size is determined according to the application in which the void structure is used, for example, the void size needs to be adjusted to a desired one according to the purpose. The void size can be evaluated by the following method, for example.
(evaluation of void size)
In the present invention, the above-mentioned void size can be quantified by the BET test method. Specifically, 0.1g of a sample (the ultra-low refractive index layer of the present invention) was put into a capillary of a specific surface area measuring apparatus (product name: ASAP2020, Micromeritics), and then dried under reduced pressure at room temperature for 24 hours to degas the gas in the void structure. Then, nitrogen gas was adsorbed on the sample to draw an adsorption isotherm, and the pore distribution was determined. The void size can thus be evaluated.
The ultralow refractive index layer of the present invention may have, for example, a pore structure (porous structure) as described above, and may be, for example, a porous structure in which the pore structure is continuous. The above-mentioned open-cell structure means, for example, a state in which the pore structures are three-dimensionally connected in the ultra-low refractive index layer (e.g., silicone porous body) of the present invention, and the internal voids of the pore structures are continuous. When the porous body has an open pore structure, the porosity occupied in the bulk body can be increased by this, but when closed-pore particles such as hollow silica are used, the open pore structure cannot be formed. In contrast, in the case where, for example, silica sol particles (a pulverized product of a gel-like silicon compound forming a sol) are used in the ultra-low refractive index layer of the present invention, since the particles have a three-dimensional dendritic structure, an open pore structure can be easily formed in a coating film (a coating film of a sol containing a pulverized product of a gel-like silicon compound) by precipitation and deposition of the dendritic particles. In addition, the ultra-low refractive index layer of the present invention more preferably forms a bulk (monolithih) structure having an open pore structure with a plurality of fine pore distributions. The monolithic structure is, for example, a structure in which nano-sized fine voids are present and a layered structure in which the fine voids are present as an open pore structure in which the same nano voids are aggregated. In forming the monolithic structure, for example, the membrane strength can be imparted by fine pores, and the high porosity can be imparted by coarse open pores, so that the membrane strength and the high porosity can be satisfied at the same time. In order to form these monolith structures, for example, it is preferable to control the pore distribution of the generated void structure in the gel (gel-like silicon compound) at the previous stage of pulverization into the silica sol particles. Further, for example, when the gel-like silicon compound is pulverized, the monolithic structure can be formed by controlling the particle size distribution of the pulverized silica sol particles to a desired size.
In the ultra-low refractive index layer of the present invention, the haze representing transparency is not particularly limited, and the upper limit thereof is, for example, less than 5%, preferably less than 3%. The lower limit is, for example, 0.1% or more and 0.2% or more, and the range is, for example, 0.1% or more and less than 5%, and 0.2% or more and less than 3%.
The haze can be measured, for example, by the following method.
(evaluation of haze)
The void layer (ultra-low refractive index layer of the present invention) was cut into a size of 50mm × 50mm and mounted on a haze meter (HM-150, manufactured by Nippon color technology research institute, Inc.) to measure haze. The haze value can be calculated by the following equation.
Haze (%) (% diffusion transmittance)/(% total light transmittance) ]. times.100 (%)
The refractive index is generally referred to as a refractive index of a medium as a ratio of a propagation speed of light in a wave surface in a vacuum to a propagation speed in the medium. The ultra-low refractive index layer of the present invention has a refractive index of, for example, 1.20 or less and 1.15 or less, a lower limit of, for example, 1.05 or more, 1.06 or more, and 1.07 or more, and ranges of, for example, 1.05 or more and 1.20 or less, 1.06 or more and 1.20 or less, and 1.07 or more and 1.15 or less.
In the present invention, the refractive index refers to a refractive index measured at a wavelength of 550nm, unless otherwise specified. The method for measuring the refractive index is not particularly limited, and the refractive index can be measured by the following method, for example.
(evaluation of refractive index)
After a void layer (ultra-low refractive index layer of the present invention) was formed on the acrylic film, the resultant was cut into a size of 50mm × 50mm, and the resultant was bonded to the surface of a glass plate (thickness: 3mm) with an adhesive layer. A central portion (diameter of about 20 mm) of the rear surface of the glass plate was filled with a black universal pen to prepare a sample which did not reflect on the rear surface of the glass plate. The sample was mounted on an ellipsometer (VASE, manufactured by J.A. Woollam Japan) and the refractive index was measured at a wavelength of 500nm and at an incident angle of 50 to 80 degrees, and the average value was used as the refractive index.
The ultra-low refractive index layer of the present invention is formed on the resin film, for example, and the adhesive peel strength indicating the adhesion to the resin film is not particularly limited, and the lower limit thereof is, for example, 1N/25mm or more, 2N/25mm or more, and 3N/25mm or more, and the upper limit thereof is, for example, 30N/25mm or less, 20N/25mm or less, and 10N/25mm or less, and ranges thereof are, for example, 1 to 30N/25mm, 2 to 20N/25mm, and 3 to 10N/25 mm.
The method for measuring the adhesive peel strength is not particularly limited, and can be measured, for example, by the following method.
(evaluation of peeling Strength)
After a void layer (ultra-low refractive index layer of the present invention) was formed on the resin film (e.g., acrylic film), the sample was sampled into a short strip of 50mm × 140mm and fixed to a stainless steel plate with a double-sided tape. An acrylic pressure-sensitive adhesive layer (thickness: 20 μm) was bonded to a PET film (T100: manufactured by Mitsubishi resin film Co., Ltd.), and an adhesive tape piece cut to 25 mm. times.100 mm was bonded to the above-mentioned void layer, followed by lamination with the above-mentioned PET film. Next, the sample was clamped on a tensile tester (AG-Xplus, Shimadzu corporation) so that the distance between chucks was 100mm, and then a tensile test was carried out at a tensile rate of 0.3 m/min. The average test force after the 50mm peel test was performed was taken as the peel strength.
The thickness of the ultralow refractive index layer of the present invention is not particularly limited, and the lower limit thereof is, for example, 0.01 μm or more, 0.05 μm or more, 0.1 μm or more, and 0.3 μm or more, and the upper limit thereof is, for example, 100 μm or less, 80 μm or less, 50 μm or less, and 10 μm or less, and the range thereof is, for example, 0.01 to 100 μm.
The ultra-low refractive index layer of the present invention contains pulverized products of a gel-like compound as described above, for example, and the pulverized products are chemically bonded to each other. In the ultra-low refractive index layer of the present invention, the form of chemical bonding (chemical bond) between the pulverized materials is not particularly limited, and specific examples of the chemical bond include a cross-linking bond and the like. The method of chemically bonding the pulverized materials to each other will be described in detail in the production method of the present invention.
The gel form of the gel-like silicon compound is not particularly limited. "gel" generally refers to a state in which a solute has a structure aggregated by losing independent mobility due to interaction, and is solidified. In addition, in the gel, in general, a wet gel is a gel containing a dispersion medium and having a uniform solute structure in the dispersion medium, and a dry gel is a gel in which a solvent is removed and the solute has a mesh structure with voids. In the present invention, the gel-like compound may be, for example, a wet gel or a dry gel.
Examples of the gel-like compound include a gel-like compound obtained by gelling a monomer compound. Specifically, the gel-like silicon compound includes, for example, a gelled product in which silicon compounds of the monomers are bonded to each other, and a gelled product in which silicon compounds of the monomers are hydrogen-bonded or intermolecular force-bonded to each other is exemplified as a specific example. Examples of the above-mentioned bonding include bonding by dehydration condensation. The above-mentioned gelling method is described later in the production method of the present invention.
In the ultra-low refractive index layer of the present invention, the volume average particle diameter showing the particle size unevenness of the pulverized material is not particularly limited, and the lower limit thereof is, for example, 0.10 μm or more, 0.20 μm or more, and 0.40 μm or more, and the upper limit thereof is, for example, 2.00 μm or less, 1.50 μm or less, and 1.00 μm or less, and ranges thereof are, for example, 0.10 μm to 2.00 μm, 0.20 μm to 1.50 μm, and 0.40 μm to 1.00 μm. The particle size distribution can be measured by, for example, a particle size distribution evaluation device such as a dynamic light scattering method or a laser diffraction method, an electron microscope such as a Scanning Electron Microscope (SEM) or a Transmission Electron Microscope (TEM), or the like.
The particle size distribution showing the particle size unevenness of the pulverized product is not particularly limited, and for example, the particle size distribution is 50 to 99.9 wt%, 80 to 99.8 wt%, 90 to 99.7 wt% for particles having a particle size of 0.4 to 1 μm, or 0.1 to 50 wt%, 0.2 to 20 wt%, 0.3 to 10 wt% for particles having a particle size of 1 to 2 μm. The particle size distribution can be measured, for example, by a particle size distribution evaluating apparatus or an electron microscope.
In the ultra-low refractive index layer of the present invention, the kind of the gel-like compound is not particularly limited. As the gel-like compound, for example, a gel-like silicon compound can be exemplified. Hereinafter, a case where the gel-like compound is a gel-like silicon compound will be described as an example, but the present invention is not limited thereto.
The aforementioned crosslinking bond is, for example, a siloxane bond. Examples of the siloxane bond include a bond of T2, a bond of T3, and a bond of T4, which are shown below. When the ultra-low refractive index layer of the present invention has a siloxane bond, for example, it may have any one type of bond, any two types of bonds, or all three types of bonds. Among the siloxane bonds, the larger the ratio of T2 and T3, the more flexible the film, the more the original characteristics of the gel can be expected, but the film strength becomes weak. On the other hand, when the ratio of T4 in the siloxane bond is large, the film strength is easily exhibited, but the void size is small and the flexibility is brittle. Therefore, it is preferable to change the T2, T3, T4 ratios according to, for example, the use.
Figure BDA0001331726870000111
When the ultra-low refractive index layer of the present invention has the siloxane bond, the ratio of T2, T3, and T4 is, for example, T2 when T2 is relatively represented by "1": t3: t4 ═ 1: [ 1-100 ]: [0 to 50], 1: [ 1-80 ]: [ 1-40 ], 1: [ 5-60 ]: [1 to 30 ].
In addition, the ultra-low refractive index layer of the present invention preferably has, for example, silicon atoms contained therein to perform siloxane bonding. As a specific example, the ratio of unbonded silicon atoms (i.e., residual silanols) in the total silicon atoms contained in the ultra-low refractive index layer is, for example, less than 50%, 30% or less, or 15% or less.
When the gel-like compound is the gel-like silicon compound, the silicon compound of the monomer is not particularly limited. Examples of the silicon compound of the monomer include compounds represented by the following formula (1). When the gel-like silicon compound is a gel in which silicon compounds of the monomers are hydrogen-bonded or intermolecular force-bonded as described above, the monomers of formula (1) may be hydrogen-bonded through each hydroxyl group, for example.
Figure BDA0001331726870000121
In the above formula (1), for example, X is 2, 3 or 4, R1Is a straight chain alkyl or branched alkyl. R is as defined above1The number of carbon atoms is, for example, 1 to 6, 1 to 4, 1 to 2. Examples of the linear alkyl group include methyl, ethyl, propyl, butyl, pentyl and hexyl, and examples of the branched alkyl group include isopropyl and isobutyl. X is, for example, 3 or 4.
As the type (1) shown in the silicon compounds specific examples, for example can be mentionedA compound represented by the following formula (1') wherein X is 3 is mentioned. In the following formula (1'), R1The same as the above formula (1), for example, methyl. When R is1When the silicon compound is a methyl group, the silicon compound is tris (hydroxy) methylsilane. When X is 3, the silicon compound is, for example, a 3-functional silane having 3 functional groups.
Figure BDA0001331726870000122
Further, as a specific example of the silicon compound represented by the above formula (1), for example, a compound in which X is 4 is exemplified. In this case, the silicon compound is, for example, a 4-functional silane having 4 functional groups.
The silicon compound of the monomer may be a hydrolysate of a silicon compound precursor, for example. The silicon compound precursor may be any one that can produce the silicon compound by hydrolysis, and specific examples thereof include compounds represented by the following formula (2).
Figure BDA0001331726870000131
In the above formula (2), for example, X is 2, 3 or 4,
R1and R2Respectively, a straight chain alkyl group or a branched chain alkyl group,
R1and R2Which may be the same or different from each other,
R1when X is 2, they may be the same or different from each other,
R2may be the same or different from each other.
X and R are as defined above1For example, X and R in the above formula (1)1The same is true. Further, the above R2For example, R in the formula (1) can be cited1Examples of (a).
Specific examples of the silicon compound precursor represented by the above formula (2) include a compound represented by the following formula (2') wherein X is 3. In the following formula (2'), R1And R2Are respectively provided withThe same as the above formula (2). When R is1And R2In the case of a methyl group, the silicon compound precursor is trimethoxy (methyl) silane (hereinafter also referred to as "MTMS").
Figure BDA0001331726870000132
The silicon compound of the monomer is preferably the 3-functional silane, for example, in view of excellent low refractive index properties. The silicon compound of the monomer is preferably the 4-functional silane, for example, in view of excellent strength (e.g., scratch resistance). The gel-like silicon compound may be used alone or in combination of two or more kinds, for example. As a specific example, the silicon compound of the monomer may contain, for example, only the 3-functional silane, only the 4-functional silane, both the 3-functional silane and the 4-functional silane, or another silicon compound. When two or more silicon compounds are used as the silicon compound of the monomer, the ratio thereof is not particularly limited and may be appropriately set.
The ultra-low refractive index layer of the present invention may contain, for example, a catalyst for chemically bonding one or more kinds of constituent units forming the fine pore structure to each other. The content of the catalyst is not particularly limited, and is, for example, 0.01 to 20 wt%, 0.05 to 10 wt%, or 0.1 to 5 wt% based on the weight of the one or more types of constituent units forming the fine pore structure.
The ultra-low refractive index layer of the present invention may further contain a crosslinking assistant for indirectly bonding the one or more kinds of constituent units forming the fine pore structure to each other, for example. The content of the crosslinking assistant is not particularly limited, and is, for example, 0.01 to 20 wt%, 0.05 to 15 wt%, or 0.1 to 10 wt% based on the weight of the one or more types of constituent units forming the fine pore structure.
The form of the ultralow refractive index layer of the present invention is not particularly limited, and is generally in the form of a film.
The ultralow refractive index layer of the present invention is, for example, a roll material. The ultralow refractive index layer of the present invention may further contain a resin film as described above, and the ultralow refractive index layer may be formed on the long-sized resin film. In this case, another long film may be laminated on the laminated film of the present invention, or another long resin film (for example, an interleaving paper, a release film, a surface protection film, or the like) may be laminated on the laminated film of the present invention including the resin film and the ultralow refractive index layer, and then wound into a roll.
The method for producing the laminated film roll of the present invention is not particularly limited, and for example, the laminated film roll can be produced by the production method of the present invention described below.
[2. method for producing laminated film coil ]
As described above, the method for producing a laminated film roll of the present invention preferably includes the steps of: a step of preparing a liquid containing fine-pore particles; coating the resin film with the liquid; and a step of drying the applied liquid, but not limited thereto. The liquid containing fine pore particles (hereinafter, may be referred to as "fine pore particle-containing liquid") is not particularly limited, and is, for example, a suspension containing the fine pore particles. In the following description, the case where the fine-pore particles are a pulverized product of a gel-like compound and the ultra-low refractive index layer is a porous body (preferably, a silicone porous body) containing the pulverized product of the gel-like compound will be mainly described. However, the present invention can be similarly carried out even in cases other than the above-mentioned case where the fine-pore particles are pulverized products of gel-like compounds. In the method for producing a laminated film roll according to the present invention, the ultra-low refractive index layer is, for example, a porous body in which fine-pore particles are chemically bonded to each other, and in the ultra-low refractive index layer forming step, for example, the fine-pore particles are chemically bonded to each other. The fine-pore particles are, for example, fine-pore particles of a silicon compound, and the porous body is a silicone porous body. The fine-pore particles of the silicon compound contain, for example, a pulverized product of a gel-like silica compound. In another embodiment of the ultra-low refractive index layer, the spacer layer is formed of a fibrous material such as nanofibers and is formed in a form containing spaces where the fibrous material is entangled with each other. The production method is the same as that of the fine pore particles. In addition, other examples include a void layer using hollow nanoparticles or nanoclay, and a void layer formed using hollow nanospheres or magnesium fluoride. These ultra-low refractive index layers may be a void layer made of a single constituent material or a void layer made of a plurality of constituent materials. The form of the void layer may be a single form as described above, or may be a void layer composed of a plurality of forms as described above. The following mainly describes the void layer of the porous body in which the fine pore particles are chemically bonded to each other.
According to the manufacturing method of the present invention, an ultra-low refractive index layer exhibiting an excellent low refractive index can be formed. The reason for this is presumed to be as follows, for example, but the present invention is not limited to this presumption.
Since the pulverized material used in the production method of the present invention is a material obtained by pulverizing the gel-like silicon compound, the three-dimensional structure of the gel-like silicon compound before pulverization is dispersed in a three-dimensional basic structure. In the production method of the present invention, the ground gel-like silicon compound is applied to the base material to form a precursor of a porous structure based on the three-dimensional basic structure. That is, according to the production method of the present invention, a novel porous structure formed of the pulverized material having the three-dimensional basic structure, which is different from the three-dimensional structure of the gel-like silicon compound, can be formed. Therefore, the finally obtained ultra-low refractive index layer can produce, for example, a low refractive index that functions to the same extent as an air layer. In the production method of the present invention, the novel three-dimensional structure is fixed in order to further chemically bond the pulverized products to each other. Therefore, the finally obtained ultra-low refractive index layer has a structure having voids, but can maintain sufficient strength and flexibility. As described above, the ultra-low refractive index layer obtained by the production method of the present invention is useful, for example, as a substitute for the air layer in terms of the function of low refractive index, strength, and flexibility. In the case of the air layer, for example, the member and the member must be laminated with a gap interposed therebetween, so that the air layer is formed between the members. However, the ultra-low refractive index layer obtained by the production method of the present invention is arranged only on a target site, for example, and can exhibit low refractive index that functions to the same extent as the above-described air layer. Therefore, as described above, it is possible to more easily and simply provide, for example, an optical member with low refractive index that functions to the same extent as the air layer, as compared with the formation of the air layer.
The method for producing the ultra-low refractive index layer of the present invention can be described with reference to the above-mentioned ultra-low refractive index layer of the present invention unless otherwise specified.
In the production method of the present invention, the gel-like compound and the pulverized product thereof, and the monomer compound and the precursor of the monomer compound can be applied to the description of the porous structure of the present invention.
The production method of the present invention has a step of preparing a liquid containing fine-pore particles as described above. When the fine-pore particles are a pulverized product of a gel-like compound, the pulverized product can be obtained by, for example, pulverizing the gel-like compound. As described above, by pulverizing the gel-like compound, the three-dimensional structure of the gel-like compound is broken and dispersed into a three-dimensional basic structure.
The formation of the gel-like compound by gelation of the monomer compound and the preparation of the pulverized product of the gel-like compound by pulverization will be described below, but the present invention is not limited to the following examples.
The gelation of the monomer compounds can be performed by, for example, hydrogen bonding or intermolecular force bonding of the monomer compounds.
Examples of the monomer compound include the silicon compound represented by the formula (1) described above in the ultra-low refractive index layer of the present invention.
Figure BDA0001331726870000161
Since the silicon compound of the formula (1) has a hydroxyl group, the monomers of the formula (1) can be hydrogen-bonded or intermolecular force-bonded via the respective hydroxyl groups, for example.
The silicon compound may be a hydrolysate of the silicon compound precursor as described above, and may be generated by hydrolyzing the silicon compound precursor represented by the formula (2) described in the ultra-low refractive index layer of the present invention.
Figure BDA0001331726870000162
The hydrolysis method of the monomer compound precursor is not particularly limited, and may be carried out by a chemical reaction in the presence of a catalyst, for example. Examples of the catalyst include acids such as oxalic acid and acetic acid. The hydrolysis reaction can be performed, for example, by slowly adding an aqueous solution of oxalic acid dropwise to a mixed solution (e.g., a suspension) of the silicon compound and dimethyl sulfoxide at room temperature, and then stirring the mixture for about 30 minutes. When the silicon compound precursor is hydrolyzed, for example, the alkoxy group of the silicon compound precursor can be completely hydrolyzed, whereby the subsequent gelation, aging, and formation of a void structure can be more efficiently expressed, and then heating and fixation can be performed.
The gelation of the monomer compound can be performed by, for example, a dehydration condensation reaction between the monomers. The dehydration condensation reaction is preferably carried out in the presence of a catalyst, and examples of the catalyst include acid catalysts such as hydrochloric acid, oxalic acid and sulfuric acid, and dehydration condensation catalysts such as basic catalysts such as ammonia, potassium hydroxide, sodium hydroxide and ammonium hydroxide. The dehydration condensation catalyst is particularly preferably a basic catalyst. In the dehydration condensation reaction, the amount of the catalyst added to the monomer compound is not particularly limited, and the amount of the catalyst is, for example, 0.1 to 10 moles, 0.05 to 7 moles, or 0.1 to 5 moles based on 1 mole of the monomer compound.
The gelation of the monomer compound is preferably performed in a solvent, for example. The ratio of the monomer compound in the solvent is not particularly limited. Examples of the solvent include dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP), N-dimethylacetamide (DMAc), Dimethylformamide (DMF), γ -butyrolactone (GBL), acetonitrile (MeCN), and Ethylene Glycol Ethyl Ether (EGEE). The solvent may be used in combination of, for example, 1 kind or 2 or more kinds. The solvent used for the above gelation is hereinafter also referred to as "gelation solvent".
The conditions for the above-mentioned gelation are not particularly limited. The treatment temperature of the solvent containing the monomer compound is, for example, 20 to 30 ℃, 22 to 28 ℃, 24 to 26 ℃, and the treatment time is, for example, 1 to 60 minutes, 5 to 40 minutes, 10 to 30 minutes. The conditions for the dehydration condensation reaction are not particularly limited, and those exemplified above can be used. By the gelation, for example, a siloxane bond grows to form silica primary particles, and further, the reaction progresses, whereby the primary particles are connected to each other in a moniliform form to form a gel having a three-dimensional structure.
The gel-like compound obtained by the gelation is preferably subjected to aging treatment after the gelation reaction. By the aging treatment, for example, primary particles of a gel having a three-dimensional structure obtained by gelation are further grown, and the size of the particles themselves can be increased, and as a result, the contact state of the neck portions where the particles are in contact with each other can be expanded from point contact to surface contact. The gel subjected to the aging treatment as described above has, for example, an increased strength of the gel itself, and as a result, the strength of the three-dimensional basic structure after pulverization can be improved. Thus, for example, in the drying step after the pulverized material is applied, the pore size of the void structure formed by the deposition of the three-dimensional basic structure can be suppressed from shrinking due to the volatilization of the solvent in the drying process.
The aging treatment can be performed, for example, by culturing the gel-like compound at a predetermined temperature for a predetermined time. The predetermined temperature is not particularly limited, but the lower limit is, for example, 30 ℃ or more, 35 ℃ or more, and 40 ℃ or more, and the upper limit is, for example, 80 ℃ or less, 75 ℃ or less, and 70 ℃ or less, and the range is, for example, 30 to 80 ℃, 35 to 75 ℃, and 40 to 70 ℃. The predetermined time is not particularly limited, and the lower limit is, for example, 5 hours or more, 10 hours or more, and 15 hours or more, and the upper limit is, for example, 50 hours or less, 40 hours or less, and 30 hours or less, and the range is, for example, 5 to 50 hours, 10 to 40 hours, and 15 to 30 hours. Further, regarding the optimum conditions for the aging, the main purpose of the conditions is to obtain the above-mentioned increase in the size of the primary particle of silica and the increase in the neck contact area, for example. Furthermore, considering the boiling point of the solvent used, for example, if the aging temperature is too high, the solvent may be excessively volatilized, and there may be a problem that the pore of the three-dimensional pore structure is closed by concentration of the coating liquid (gel liquid). On the other hand, if the curing temperature is too low, the effects of the curing cannot be sufficiently obtained, and the temperature unevenness with time in the mass production process increases, which may result in poor quality products.
The aging treatment may be performed using, for example, the same solvent as the gelling treatment, and specifically, the reaction product after the gelling treatment (i.e., the solvent containing the gel-like compound) is preferably directly performed. The number of moles of the residual silanol groups contained in the gel (the gel-like compound, for example, the gel-like silicon compound) after completion of the aging treatment after gelation is, for example, a ratio of the residual silanol groups to 100 moles of alkoxy groups of the added raw material (for example, the monomer compound precursor), and the upper limit thereof is, for example, 50% or less, 40% or less, and 30% or less, the lower limit thereof is, for example, 1% or more, 3% or more, and 5% or more, and the range thereof is, for example, 1 to 50%, 3 to 40%, and 5 to 30%. In order to increase the hardness of the gel, for example, the lower the number of moles of residual silanol groups, the more preferable. If the number of moles of silanol groups is too high, for example, the void structure may not be maintained until the precursor of the silicone porous body is crosslinked. On the other hand, if the number of moles of silanol groups is too low, for example, in the step of preparing the fine pore particle-containing liquid (for example, suspension) and/or in the subsequent steps, the pulverized product of the gel-like compound may not be crosslinked, and sufficient film strength may not be imparted. In addition, the above is an example of the silanol group, and for example, when a silicon compound of a monomer is modified with various reactive functional groups, the same phenomenon can be applied to each functional group.
The monomer compound is gelled in the gelling solvent, and the resultant gelled compound is pulverized. The pulverization may be performed, for example, by directly pulverizing the gel-like compound in the gelling solvent, or by replacing the gelling solvent with another solvent and then pulverizing the gel-like compound in the other solvent. Further, for example, since the catalyst used and the solvent used in the gelation reaction remain even after the aging step, when gelation (pot life) of the liquid occurs with time and the drying efficiency in the drying step is lowered, it is preferable to replace the catalyst with another solvent. The other solvent is hereinafter also referred to as a "solvent for pulverization".
The solvent for pulverization is not particularly limited, and an organic solvent can be used, for example. Examples of the organic solvent include solvents having a boiling point of 130 ℃ or lower, a boiling point of 100 ℃ or lower, and a boiling point of 85 ℃ or lower. Specific examples thereof include isopropyl alcohol (IPA), ethanol, methanol, butanol, Propylene Glycol Monomethyl Ether (PGME), methyl cellosolve, acetone, and Dimethylformamide (DMF). The above-mentioned pulverizing solvents may be used in combination of, for example, 1 kind or 2 or more kinds.
The combination of the gelling solvent and the pulverizing solvent is not particularly limited, and examples thereof include a combination of DMSO and IPA, a combination of DMSO and ethanol, a combination of DMSO and methanol, and a combination of DMSO and butanol. By replacing the gelling solvent with the pulverizing solvent in this manner, a more uniform coating film can be formed in the coating film formation described later, for example.
The method for pulverizing the gel-like compound is not particularly limited, and for example, it can be performed by an ultrasonic homogenizer, a high-speed rotary homogenizer, another pulverizing device utilizing cavitation, a pulverizing device in which liquids are obliquely impacted at high pressure, or the like. While a device for media pulverization such as a ball mill physically breaks the pore structure of the gel during pulverization, for example, a cavitation type pulverizing device preferable in the present invention such as a homogenizer is a media-free type, and therefore, the bonding surface of the silica particles having relatively weak bonding already included in the three-dimensional structure of the gel can be peeled off by a high-speed shearing force. The three-dimensional structure of the sol thus obtained can retain a void structure having a particle size distribution in a certain range, for example, and can be reformed by deposition at the time of coating and drying. The conditions for the above-mentioned pulverization are not particularly limited, and for example, it is preferable to pulverize the gel without volatilizing the solvent by instantaneously imparting a high-speed flow. For example, it is preferable to pulverize the material so as to have a particle size variation (for example, volume average particle size or particle size distribution) as described above. If the amount of work such as grinding time and strength is insufficient, coarse particles may remain and dense fine pores may not be formed, and appearance defects may increase, and high quality may not be obtained. On the other hand, if the work amount is too large, for example, sol particles finer than a desired particle size distribution may be formed, and the pore size deposited after coating and drying may become fine, which may fail to satisfy a desired porosity.
A liquid (for example, a suspension) containing the fine-pore particles can be prepared as described above. Further, after or during the production of the liquid containing the fine-pore particles, a catalyst for chemically bonding the fine-pore particles to each other may be added to produce a liquid containing the fine-pore particles and the catalyst. The amount of the catalyst to be added is not particularly limited, and is, for example, 0.01 to 20 wt%, 0.05 to 10 wt%, or 0.1 to 5 wt% based on the weight of the fine-pore particles (for example, a pulverized product of a gel-like silicon compound). The catalyst can chemically bond the fine pore particles to each other in, for example, a bonding step described later. The catalyst may be, for example, a catalyst that promotes the crosslinking and bonding of the fine-pore particles. The chemical reaction for chemically bonding the fine-pore particles to each other is preferably a dehydration condensation reaction of residual silanol groups contained in the silica sol molecules. By promoting the reaction of the hydroxyl groups of the silanol groups with each other by the catalyst, a continuous film formation in which the void structure is cured in a short time can be realized. Examples of the catalyst include a photoactive catalyst and a thermally active catalyst. According to the above-mentioned photoactive catalyst, the above-mentioned fine pore particles can be chemically bonded (e.g., cross-linked) to each other, for example, without heating. This makes it difficult for shrinkage to occur due to heating, for example, and therefore a higher porosity can be maintained. In addition to the above-described catalyst, a substance capable of generating a catalyst (catalyst generator) may be used instead. For example, it may be: the catalyst is a crosslinking reaction accelerator, and the catalyst generator is a substance that generates the crosslinking reaction accelerator. For example, in addition to the above-mentioned photoactive catalyst, or instead of it, a substance that generates a catalyst by light (photocatalyst generator) may be used; instead of the above-described thermally active catalyst, a substance that generates a catalyst by heat (thermal catalyst generator) may be used. The photocatalyst generator is not particularly limited, and examples thereof include a photobase generator (a catalyst that generates a basic catalyst by irradiation with light), a photoacid generator (a substance that generates an acidic catalyst by irradiation with light), and the like, and a photobase generator is preferable. Examples of the photobase generator include: 9-Anthranylmethyl N, N-diethylcarbamate (9-anthracylmethyl N, N-diethylcarbamatee, tradename WPBG-018), (E) -1- [3- (2-hydroxyphenyl) -2-acryloyl ] piperidine ((E) -1- [3- (2-hydroxyphenyl) -2-propenoyl ] piperidine, tradename WPBG-027), 1- (anthraquinone-2-yl) ethylimidazolyl carboxylate (1- (anthracquinon-2-yl) ethylimidazolyl ester, tradename WPBG-140), 2-nitrophenylmethyl 4-methacryloyloxypiperidine-1-carboxylate (tradename WPBG-165), 1, 2-diisopropyl-3- [ bis (dimethylamino) methylene ] guanidinium 2- (3-benzoylphenyl) propionate (tradename WPBG-266), 1, 2-dicyclohexyl-4, 4,5, 5-tetramethylbiguanidinium n-butyltriphenylborate (trade name: WPBG-300), 2- (9-oxaxanthen-2-yl) propionic acid 1,5, 7-triazabicyclo [4.4.0] dec-5-ene (Tokyo chemical Co., Ltd.), a 4-piperidinemethanol-containing compound (trade name: HDPD-PB 100: manufactured by Heraeus corporation), and the like. The trade name of "WPBG" is the same as that of Wako pure chemical industries, Ltd. Examples of the photoacid generator include an aromatic sulfonium salt (trade name SP-170: ADEKA), a triarylsulfonium salt (trade name CPI 101A: San-Apro), and an aromatic iodonium salt (trade name Irgacure 250: Ciba Japan). The catalyst for chemically bonding the fine-pore particles to each other is not limited to the above-mentioned photoactive catalyst, and may be a thermally active catalyst such as urea, for example. Examples of the catalyst for chemically bonding the fine pore particles to each other include basic catalysts such as potassium hydroxide, sodium hydroxide, and ammonium hydroxide, and acid catalysts such as hydrochloric acid, acetic acid, and oxalic acid. Among them, a basic catalyst is preferable. The catalyst for chemically bonding the fine-pore particles to each other may be added to a sol particle liquid (e.g., suspension) containing the pulverized product (fine-pore particles) immediately before coating, or may be used as a mixed liquid obtained by mixing the catalyst into a solvent. The mixed solution may be, for example: a coating solution obtained by dissolving the catalyst in a solvent, a solution obtained by dissolving the catalyst in a solvent, and a dispersion obtained by dispersing the catalyst in a solvent are directly added. The solvent is not particularly limited, and examples thereof include various organic solvents, water, and buffers.
For example, when the fine-pore particles are pulverized products of a gel-like silicon compound obtained from a silicon compound containing at least a saturated bond functional group having a 3-or less function, a crosslinking assistant for indirectly bonding the fine-pore particles to each other may be further added after or during the production of the liquid containing the fine-pore particles. The crosslinking assistant penetrates between the particles, and the particles and the crosslinking assistant interact or bond with each other, whereby the particles slightly separated from each other can be bonded to each other, and the strength can be efficiently improved. As the crosslinking assistant, a multi-crosslinking silane monomer is preferable. Specifically, the multi-crosslinkable silane monomer has, for example, 2 to 3 alkoxysilyl groups, and the chain length between the alkoxysilyl groups may be 1 to 10 carbon atoms and may contain an element other than carbon. Examples of the crosslinking assistant include: bis (trimethoxysilyl) ethane, bis (triethoxysilyl) ethane, bis (trimethoxysilyl) methane, bis (triethoxysilyl) propane, bis (trimethoxysilyl) propane, bis (triethoxysilyl) butane, bis (trimethoxysilyl) butane, bis (triethoxysilyl) pentane, bis (trimethoxysilyl) pentane, bis (triethoxysilyl) hexane, bis (trimethoxysilyl) -N-butyl-N-propyl-ethane-1, 2-diamine, tris- (3-trimethoxysilylpropyl) isocyanurate, tris- (3-triethoxysilylpropyl) isocyanurate, and the like. The amount of the crosslinking assistant added is not particularly limited, and is, for example, 0.01 to 20 wt%, 0.05 to 15 wt%, or 0.1 to 10 wt% based on the weight of the fine-pore particles of the silicon compound.
Next, the production method of the present invention includes a step of coating the fine pore particle-containing liquid (e.g., suspension) on the resin film as described above. The coating may be performed by various coating methods described below, for example, and is not limited thereto. Further, the precursor (coating film) of the porous body can be formed by directly coating the solvent containing the pulverized product on the base material. The porous body precursor may be referred to as a coating layer, for example. The porous body precursor, that is, the precursor of the porous body before the bonding step described later, may be referred to as a precursor film (or precursor layer) for the ultra-low refractive index layer of the present invention. By forming the precursor (coating film) of the porous body, a new three-dimensional structure can be constructed by, for example, settling and depositing the pulverized material after the three-dimensional structure is broken.
The solvent (hereinafter also referred to as "coating solvent") is not particularly limited, and an organic solvent may be used, for example. Examples of the organic solvent include solvents having a boiling point of 130 ℃ or lower. Specific examples thereof include IPA, ethanol, methanol, butanol, and the like, and the same solvents as those for pulverization can be used. In the case where the present invention includes the step of pulverizing the gel-like compound, the solvent for pulverization containing the pulverized product of the gel-like compound may be used as it is, for example, in the step of forming the precursor of the porous body.
In the coating step, for example, the pulverized product in a sol state (hereinafter also referred to as "sol particle solution") dispersed in the solvent is preferably coated on the substrate. The sol particle solution of the present invention can be coated on a substrate, dried, and then chemically crosslinked in a bonding step to continuously form a void layer having a film strength of a certain level or more. The "sol" in the present invention means a state in which silica sol particles having a nano three-dimensional structure, which maintain a part of a void structure, are dispersed in a solvent by pulverizing the three-dimensional structure of a gel to exhibit fluidity.
The concentration of the pulverized material in the solvent is not particularly limited, and is, for example, 0.3 to 50% (v/v), 0.5 to 30% (v/v), or 1.0 to 10% (v/v). If the concentration of the pulverized material is too high, for example, the fluidity of the sol particle solution may be significantly reduced, and aggregates and coating streaks may occur during coating. On the other hand, if the concentration of the pulverized material is too low, for example, not only a considerable amount of time is required for drying the solvent of the sol particle solution, but also the residual solvent immediately after drying is increased, and thus the porosity may be decreased.
The physical properties of the sol are not particularly limited. The shear viscosity of the sol is, for example, 100 cPa.s or less, 10 cPa.s or less, or 1 cPa.s or less at a shear rate of 10001/s. If the shear viscosity is too high, for example, a coating streak may occur, and a problem such as a decrease in transfer rate of gravure coating may be observed. Conversely, when the shear viscosity is too low, for example, the wet coating thickness during coating may not be increased and a desired thickness may not be obtained after drying.
The coating amount of the ground product to the base material is not particularly limited, and may be appropriately set according to, for example, a desired thickness of the silicone porous body. As a specific example, the silicone porous body having a thickness of 0.1 to 1000 μm is formedIn the case, the amount of the pulverized material to be coated on the base material is 1m per the base material2The area is, for example, 0.01 to 60000. mu.g, 0.1 to 5000. mu.g, 1 to 50. mu.g. The preferable coating amount of the sol particle solution is not easily defined because it depends on, for example, the concentration of the solution or the coating method, and it is preferable to coat as thin a layer as possible in consideration of productivity. If the coating amount is too large, the possibility of drying in a drying oven before the solvent is volatilized, for example, increases. Thus, before the nano-sized sol particles are precipitated and deposited in the solvent to form a void structure, the solvent may be dried to inhibit formation of voids, thereby significantly reducing the porosity. On the other hand, if the coating amount is too small, there is a possibility that the risk of occurrence of coating dents due to unevenness of the substrate and variation in hydrophilicity and hydrophobicity is increased.
Further, the production method of the present invention has a step of drying the fine pore particle-containing liquid (precursor of the porous body (coating film)) after coating as described above. The drying treatment can remove, for example, not only the solvent (solvent contained in the sol particle solution) from the precursor of the porous body, but also the sol particles are precipitated and deposited in the drying treatment to form a void structure. The temperature of the drying treatment is, for example, 50 to 250 ℃, 60 to 150 ℃, 70 to 130 ℃, and the time of the drying treatment is, for example, 0.1 to 30 minutes, 0.2 to 10 minutes, 0.3 to 3 minutes. As for the drying treatment temperature and time, for example, in the connection with continuous productivity or high porosity, a lower temperature and a shorter time are preferable. If the conditions are too severe, for example, in the case where the substrate is a resin film, the substrate may be stretched in a drying furnace due to the approach of the glass transition temperature of the substrate, and a defect such as a crack may occur in the formed void structure immediately after coating. On the other hand, if the conditions are too mild, for example, the solvent remains at the time of leaving the drying oven, and therefore, there is a possibility that defects in appearance such as scratches may occur when rubbing against the roller in the next step.
The drying treatment may be, for example, natural drying, heat drying, or reduced pressure drying. The drying method is not particularly limited, and a general heating mechanism can be used, for example. Examples of the heating means include a hot air blower, a heating roller, and a far infrared heater. Among them, in the case of assuming industrial continuous production, it is preferable to use heat drying. The solvent used is preferably a solvent having a low surface tension in order to suppress the shrinkage stress caused by the volatilization of the solvent during drying and the crack phenomenon of the void layer (the silicone porous body) caused by the shrinkage stress. Examples of the solvent include, but are not limited to, lower alcohols typified by isopropyl alcohol (IPA), hexane, perfluorohexane, and the like.
The drying treatment may be, for example, natural drying, heating drying, or drying under reduced pressure. The drying method is not particularly limited, and a general heating mechanism can be used, for example. Examples of the heating means include a hot air blower, a heating roller, and a far infrared heater. Among them, in the case of assuming industrial continuous production, it is preferable to use heat drying. In addition, the solvent used is preferably a solvent having a low surface tension in order to suppress the shrinkage stress caused by the volatilization of the solvent during drying and the crack phenomenon of the void layer (the silicone porous body) caused by the shrinkage stress. Examples of the solvent include, but are not limited to, lower alcohols typified by isopropyl alcohol (IPA), hexane, perfluorohexane, and the like. Further, for example, a small amount of a perfluoro surfactant or a silicon surfactant may be added to the IPA or the like to reduce the surface tension.
According to the production method of the present invention, for example, the three-dimensional structure of the pulverized material in the precursor of the porous body is fixed. In the case of immobilization by conventional sintering, dehydration condensation of silanol groups and formation of siloxane bonds are induced by, for example, high-temperature treatment at 200 ℃ or higher. In the present invention, by reacting various additives that catalyze the dehydration condensation reaction, for example, in the case where the substrate is a resin film, a void structure can be formed and fixed continuously at a low drying temperature of about 100 ℃ and a short treatment time of less than several minutes without causing damage to the substrate.
The method of chemically bonding is not particularly limited, and may be appropriately determined according to the type of the gel-like silicon compound. As a specific example, the chemical bonding may be performed by chemical cross-linking bonding of the pulverized materials, and when inorganic particles such as titanium oxide are added to the pulverized materials, it is also considered that the inorganic particles and the pulverized materials may be chemically cross-linked. In addition, in the case of carrying a biocatalyst such as an enzyme, a site different from the catalytic active site may be chemically cross-linked to the pulverized product. Therefore, the present invention is not limited to the above-described void layer (silicone porous body) formed by the sol particles, but may be applied to an organic-inorganic hybrid void layer, a host-guest void layer, and the like.
The bonding may be performed by, for example, a chemical reaction in the presence of a catalyst that chemically bonds the pulverized products (fine pore particles) to each other, depending on the type of the pulverized product of the gel-like compound. The catalyst may be, for example, a catalyst that promotes the crosslinking and bonding of the fine-pore particles to each other. The chemical reaction in the present invention is preferably a dehydration condensation reaction of residual silanol groups contained in the silica sol molecules. By promoting the reaction of the hydroxyl groups of the silanol groups with each other by the catalyst, continuous film formation for curing the void structure can be performed in a short time. Examples of the catalyst include, but are not limited to, basic catalysts such as potassium hydroxide, sodium hydroxide, and ammonium hydroxide, and acid catalysts such as hydrochloric acid, acetic acid, and oxalic acid. The catalyst for the dehydration condensation reaction is particularly preferably a basic catalyst. Further, a photoacid generating catalyst, a photobase generating catalyst, a photoacid generator, a photobase generator, or the like, which exhibits catalytic activity by irradiation with light (e.g., ultraviolet light), may also be preferably used. The photoacid generating catalyst, the photobase generating catalyst, the photoacid generator, and the photobase generator are not particularly limited, and examples thereof include those described above. The catalyst may be added to the fine particle-containing liquid (for example, a suspension of the pulverized product (fine particles)) in the step of preparing the fine particle-containing liquid, for example, as described above. More specifically, for example, the catalyst is preferably added to a sol particle solution (for example, a suspension) containing the pulverized product (fine pore particles) immediately before coating, or is preferably used as a mixed solution obtained by mixing the catalyst into a solvent. The mixed solution may be, for example: a coating solution obtained by dissolving the catalyst in a solvent, a solution obtained by dissolving the catalyst in a solvent, and a dispersion obtained by dispersing the catalyst in a solvent are directly added. The solvent is not particularly limited, and examples thereof include water and a buffer solution as described above.
The step of carrying out (causing) the chemical reaction in the presence of the catalyst in the production method of the present invention is not particularly limited. The above chemical reaction may be carried out, for example, by: irradiating or heating the coating film containing the catalyst added in advance to the sol particle solution (for example, suspension); or spraying the catalyst on the coating film and then irradiating or heating; or irradiating or heating while spraying the catalyst. For example, when the catalyst is an optically active catalyst, the fine pore particles may be chemically bonded to each other by light irradiation to form the ultra-low refractive index layer. In addition, when the catalyst is a thermally active catalyst, the ultra-low refractive index layer may be formed by chemically bonding the fine pore particles to each other by heating. The accumulated light amount in the above light irradiation is not particularly limited, and is, for example, 200 to 800mJ/cm in terms of a @ 360nm2、250～600mJ/cm2Or 300 to 400mJ/cm2. From the viewpoint of preventing the effect of insufficient irradiation amount and failure to progress decomposition of light absorption by the catalyst generator, 200mJ/cm2The above accumulated light amount is preferable. In addition, from the viewpoint of preventing the substrate under the void layer from being damaged to generate thermal wrinkles, 800mJ/cm2The following accumulated light amount is preferable. The conditions of the heat treatment are not particularly limited, and the heating temperature is, for example, 50 to 250 ℃, 60 to 150 ℃, and 70 to 130 ℃, and the heating time is, for example, 0.1 to 30 minutes, 0.2 to 10 minutes, and 0.3 to 3 minutes.Alternatively, the step of drying the coated sol particle solution (e.g., suspension) may also be performed as a step of performing a chemical reaction in the presence of the catalyst. That is, in the step of drying the sol particle liquid (for example, suspension) after coating, the pulverized products (fine pore particles) may be chemically bonded to each other by a chemical reaction in the presence of the catalyst. In this case, the pulverized products (fine pore particles) may be further strongly bonded to each other by further heating the coating film after the drying step. Further, it is presumed that the chemical reaction in the presence of the catalyst may be caused in the step of preparing the fine particle-containing liquid (for example, suspension) and the step of coating the fine particle-containing liquid. However, this presumption does not set any limit to the present invention. The solvent used is preferably a solvent having a low surface tension in order to suppress, for example, shrinkage stress caused by volatilization of the solvent during drying and a crack phenomenon of the void layer caused by the shrinkage stress. Examples thereof include, but are not limited to, lower alcohols typified by isopropyl alcohol (IPA), hexane, perfluorohexane, and the like.
The ultralow refractive index layer (laminated film roll) of the present invention can be produced as described above, but the production method of the present invention is not limited thereto.
The obtained ultralow refractive index layer (laminated film roll) of the present invention may be subjected to a strength-improving step (hereinafter, also referred to as "aging step") of improving the strength by, for example, heat aging. For example, when the ultralow refractive index layer of the present invention is laminated on a resin film, the strength-improving step (aging step) can improve the adhesion peel strength to the resin film. In the strength-improving step (aging step), for example, the ultralow refractive index layer of the present invention may be heated. The temperature in the aging step is, for example, 40 to 80 ℃, 50 to 70 ℃, 55 to 65 ℃. The reaction time is, for example, 5 to 30hr, 7 to 25hr or 10 to 20 hr. In the aging step, for example, by setting the heating temperature to a low temperature, the adhesive peel strength can be improved while suppressing shrinkage of the ultra-low refractive index layer, and both high porosity and strength can be achieved.
The phenomenon and mechanism caused in the strength-improving step (aging step) are not clear, but it is considered that the strength is improved by further progressing the chemical bonding (for example, crosslinking reaction) of the fine-pore particles with each other by the catalyst contained in the ultra-low refractive index layer of the present invention. As a specific example, it is considered that when the fine-pore particles are fine-pore particles of a silicon compound (for example, a pulverized product of a gel-like silica compound) and residual silanol groups (OH groups) are present in the ultra-low refractive index layer, the residual silanol groups are chemically bonded to each other by a crosslinking reaction. The catalyst contained in the ultralow refractive index layer of the present invention is not particularly limited, and may be, for example, a catalyst used in the bonding step, a basic substance generated by irradiation of light with the base photocatalyst used in the bonding step, an acidic substance generated by irradiation of light with the acid photocatalyst used in the bonding step, or the like. However, the description is illustrative and not restrictive.
Further, an adhesive layer may be further formed on the ultralow refractive index layer of the present invention (adhesive layer forming step). Specifically, for example, the adhesive layer may be formed by applying (painting) an adhesive or bonding agent to the ultralow refractive index layer of the present invention. The adhesive layer may be formed on the ultralow refractive index layer of the present invention by bonding the adhesive layer side of an adhesive tape or the like in which the adhesive layer is laminated on a substrate to the ultralow refractive index layer of the present invention. In this case, the substrate such as the pressure-sensitive adhesive tape may be in a state of being directly bonded to the pressure-sensitive adhesive layer or may be peeled from the pressure-sensitive adhesive layer. In the present invention, the "pressure-sensitive adhesive" and the "pressure-sensitive adhesive layer" refer to, for example, an agent or a layer on the assumption that an adherend is peeled off again. In the present invention, the "adhesive agent" and the "adhesive layer" refer to, for example, an agent or a layer that is not premised on re-peeling of an adherend. However, in the present invention, "adhesive" and "binder" are not clearly distinguishable, and "adhesive layer" are not clearly distinguishable either. In the present invention, the adhesive or bonding agent for forming the adhesive bonding layer is not particularly limited, and for example, a general adhesive or bonding agent can be used. Examples of the adhesive or bonding agent include polymer adhesives such as acrylic, vinyl alcohol, silicone, polyester, polyurethane, and polyether adhesives, and rubber adhesives. Further, an adhesive agent composed of a water-soluble crosslinking agent of a vinyl alcohol polymer such as glutaraldehyde, melamine, oxalic acid, or the like may be mentioned. These binders and adhesives may be used alone in 1 kind, or may be used in combination (for example, by mixing, laminating, or the like). The thickness of the adhesive layer is not particularly limited, and is, for example, 0.1 to 100 μm, 5 to 50 μm, 10 to 30 μm or 12 to 25 μm.
Further, the ultralow refractive index layer of the present invention may be reacted with the adhesive layer to form an intermediate layer disposed between the ultralow refractive index layer of the present invention and the adhesive layer (intermediate layer forming step). The interlayer can prevent the ultra-low refractive index layer of the present invention from easily peeling off from the adhesive layer, for example. The reason (mechanism) is not clear, but it is presumed that the reason is due to, for example, the anchoring property (anchoring effect) of the intermediate layer. The anchoring property (anchoring effect) is a phenomenon (effect) in which the interface is firmly fixed because the intermediate layer forms a structure that crosses the inside of the void layer in the vicinity of the interface between the void layer and the intermediate layer. However, the reason (mechanism) is an example of the reason (mechanism) presumed, and the present invention is not limited thereto. The reaction between the ultralow refractive index layer of the present invention and the adhesive layer is not particularly limited, and may be a reaction utilizing a catalytic action, for example. The catalyst may be, for example, a catalyst contained in the ultralow refractive index layer of the present invention. Specifically, for example, the catalyst used in the bonding step may be a basic substance generated by irradiation of light with the base photocatalyst used in the bonding step, an acidic substance generated by irradiation of light with the acid photocatalyst used in the bonding step, or the like. The reaction between the ultra-low refractive index layer of the present invention and the adhesive bonding layer may be a reaction (for example, a crosslinking reaction) that can form a new chemical bond. The temperature of the reaction is, for example, 40 to 80 ℃, 50 to 70 ℃, 55 to 65 ℃. The reaction time is, for example, 5 to 30hr, 7 to 25hr or 10 to 20 hr. The intermediate layer forming step may also serve as the strength-improving step (aging step) for improving the strength of the ultralow refractive index layer of the present invention.
The ultralow refractive index layer of the present invention obtained as described above can be further laminated with another film (layer) to produce a laminated structure containing the porous structure. In this case, in the laminated structure, the respective components may be laminated via an adhesive or bonding agent, for example.
From the viewpoint of efficiency, the above-mentioned components may be laminated by a continuous process using a long film (so-called Roll to Roll) or the like, or when the substrate is a molded article, a member or the like, those subjected to a batch process may be laminated.
Hereinafter, a method of forming the ultra-low refractive index layer of the present invention on a substrate will be described as an example of a continuous treatment process with reference to fig. 1 to 3. Fig. 2 shows a step of forming the silicone porous body (ultra-low refractive index layer) and then laminating a protective film and winding it, and when another functional film is laminated, the above method may be used, or after another functional film is coated and dried, the formed silicone porous body (ultra-low refractive index layer) may be laminated immediately before winding. The film formation method shown in the drawings is merely an example, and is not limited thereto.
In addition, the substrate may be a resin film described in the description of the ultralow refractive index layer of the present invention. In this case, the ultralow refractive index layer of the present invention can be obtained by forming the ultralow refractive index layer on the substrate. The ultralow refractive index layer of the present invention can also be obtained by forming the ultralow refractive index layer on the substrate and then laminating the ultralow refractive index layer on the resin film described in the description of the ultralow refractive index layer of the present invention.
Fig. 1 is a cross-sectional view schematically showing an example of a process in the method of forming the ultra-low refractive index layer on the substrate. In fig. 1, the method for forming the ultra-low refractive index layer includes: a coating step (1) of coating a substrate 10 with a sol particle solution 20 ″ of a pulverized product of the gel-like compound; a coating film forming step (drying step) (2) of drying the sol particle solution 20 ″ to form a coating film 20' as a precursor layer of the ultra-low refractive index layer; and a chemical treatment step (e.g., a crosslinking treatment step) (3) of chemically treating (e.g., crosslinking treatment) the coating film 20' to form the ultra-low refractive index layer 20. This allows the formation of ultra-low refractive index layer 20 on substrate 10 as shown. The method for forming the ultra-low refractive index layer may or may not include any steps other than the steps (1) to (3).
In the coating step (1), the coating method of the sol particle solution 20 ″ is not particularly limited, and a general coating method can be employed. Examples of the coating method include a slot die (slot die) method, a reverse gravure coating method, a microgravure coating method (microgravure coating method), a dipping method (dip coating method), a spin coating method, a brush coating method, a roll coating method, a flexographic printing method, a wire bar coating method, a spray coating method, an extrusion coating method, a curtain coating method, and a reverse coating method. Among them, from the viewpoint of productivity, smoothness of the coating film, and the like, extrusion coating, curtain coating, roll coating, micro-gravure coating, and the like are preferable. The coating amount of the sol particle solution 20 ″ is not particularly limited, and may be appropriately set so that the ultra-low refractive index layer 20 has an appropriate thickness, for example. The thickness of the ultra-low refractive index layer 20 is not particularly limited, and may be, for example, as described above.
In the drying step (2), the sol particle solution 20 ″ is dried (i.e., the dispersion medium contained in the sol particle solution 20 ″ is removed) to form a coating film (precursor layer) 20'. The conditions of the drying treatment are not particularly limited, and are as described above.
Further, in the chemical treatment step (3), the coating film 20 'containing the catalyst (for example, a photoactive catalyst or a thermally active catalyst such as KOH) added before coating is irradiated with light or heated, and the pulverized materials in the coating film 20' are chemically bonded (for example, crosslinked) to each other, thereby forming the ultra-low refractive index layer 20. The light irradiation or heating conditions in the chemical treatment step (3) are not particularly limited, and are as described above. As the substrate 10, for example, the resin film may be used, and the ultra-low refractive index layer 20 may be directly laminated on the resin film (substrate 10).
Next, fig. 2 schematically shows an example of a coating apparatus of the slit die method and a method for forming the ultra-low refractive index layer using the same. Fig. 2 is a cross-sectional view, but the pattern filling is omitted for easy visibility.
As shown in the drawing, each step in the method using this apparatus is performed while conveying the substrate 10 in one direction by a roller. The conveying speed is not particularly limited, and is, for example, 1 to 100 m/min, 3 to 50 m/min, or 5 to 30 m/min.
First, the coating step (1) of coating the sol particle solution 20 ″ on the substrate 10 is performed on the coating roller 102 while the substrate 10 is discharged from the delivery roller 101 and conveyed, and then the process proceeds to the drying step (2) in the oven zone 110. In the coating apparatus of fig. 2, a pre-drying step is performed after the coating step (1) and before the drying step (2). The preliminary drying step may be performed at room temperature without heating. The heating mechanism 111 is used in the drying step (2). As described above, the heating mechanism 111 may be suitably used in a hot air blower, a heating roller, a far infrared heater, or the like. For example, the drying step (2) may be divided into a plurality of steps, and the drying temperature may be increased as the subsequent drying step proceeds.
After the drying process (2), a chemical treatment process (3) is performed in the chemical treatment zone 120. In the chemical treatment step (3), for example, when the dried coating film 20' contains a photoactive catalyst, light irradiation is performed by lamps (light irradiation means) 121 disposed above and below the substrate 10. Alternatively, for example, when the dried coating film 20' contains a thermally active catalyst, a heat gun (heating means) is used instead of the lamp (light irradiation device) 121, and the heat gun 121 disposed above and below the substrate 10 heats the substrate 10. By this crosslinking treatment, the above pulverized materials in the coating film 20' are chemically bonded to each other, and the ultra-low refractive index layer 20 is cured and strengthened. In the present example, the chemical treatment step (3) is performed after the drying step (2), but as described above, there is no particular limitation on the stage of the production method of the present invention at which the chemical bonding between the pulverized materials occurs. For example, as described above, the drying step (2) may also serve as the chemical treatment step (3). Even when the chemical bonding occurs in the drying step (2), the chemical treatment step (3) may be further performed to make the chemical bonding between the pulverized materials stronger. The chemical bonding between the pulverized materials may be caused in a step (e.g., a pre-drying step, a coating step (1), a step of preparing a coating liquid (e.g., a suspension), etc.) preceding the drying step (2). After the chemical treatment step (3), the laminate having the ultra-low refractive index layer 20 formed on the substrate 10 is wound by the winding roll 105. As the substrate 10, for example, the resin film may be used, and the ultra-low refractive index layer 20 may be directly laminated on the resin film (substrate 10). In fig. 2, the ultra-low refractive index layer 20 of the laminate is covered and protected by a protective sheet released from the roller 106. Here, instead of the protective sheet, another layer formed of a long film may be laminated on the ultra-low refractive index layer 20.
Fig. 3 schematically shows an example of a coating apparatus of a micro-gravure method (micro-gravure coating method) and a method for forming the ultra-low refractive index layer using the same. Although this figure is a cross-sectional view, the pattern filling is omitted for ease of viewing.
As shown in the drawing, each step in the method using this apparatus is performed while conveying the substrate 10 in one direction by a roller, as in fig. 2. The conveying speed is not particularly limited, and is, for example, 1 to 100 m/min, 3 to 50 m/min, or 5 to 30 m/min.
First, the coating step (1) of coating the sol particle solution 20 ″ on the substrate 10 is performed while the substrate 10 is discharged from the delivery roller 201 and conveyed. As shown in the figure, the sol particle solution 20 ″ is coated by a reservoir 202, a doctor blade (doctor knife)203, and a micro-relief 204. Specifically, the sol particle solution 20 ″ stored in the reservoir 202 is attached to the surface of the micro-relief 204, and the surface of the base material 10 is coated with the micro-relief 204 while controlling the thickness to a predetermined value by the doctor blade 203. The micro-recessed plate 204 is an example, and any other coating mechanism may be used without being limited thereto.
Then, the drying step (2) is performed. Specifically, as shown in the figure, the substrate 10 coated with the sol particle solution 20 ″ is conveyed in the oven zone 210, and heated by the heating means 211 in the oven zone 210 to dry the sol particle solution 20 ″. The heating mechanism 211 may be the same as that shown in fig. 2, for example. For example, the drying process (2) may be divided into a plurality of processes by dividing the oven area 210 into a plurality of blocks, and the drying temperature may be increased as the subsequent drying process proceeds. After the drying process (2), a chemical treatment process (3) is performed in the chemical treatment zone 220. In the chemical treatment step (3), for example, when the dried coating film 20' contains a photoactive catalyst, light irradiation is performed by lamps (light irradiation means) 221 disposed above and below the substrate 10. Alternatively, for example, when the dried coating film 20' contains a thermally active catalyst, a heat gun (heating means) is used instead of the lamp (light irradiation device) 221, and the heat gun (heating means) 221 disposed below the substrate 10 heats the substrate 10. By this crosslinking treatment, the above pulverized materials in the coating film 20' are chemically bonded to each other, and the ultra-low refractive index layer 20 is formed.
After the chemical treatment step (3), the laminate having the porous structure 20 formed on the substrate 10 is wound by the winding roll 251. As the substrate 10, for example, the resin film may be used, and the ultra-low refractive index layer 20 may be directly laminated on the resin film (substrate 10). Thereafter, another layer may be laminated on the laminate. Further, for example, other layers may be stacked on the laminate before the laminate is wound by the winding roll 251.
Fig. 4 to 6 show another example of the continuous treatment step in the method for forming the ultra-low refractive index layer of the present invention. This method is similar to the method shown in fig. 1 to 3 except that the strength-increasing step (aging step) (4) is performed after the chemical treatment step (e.g., crosslinking treatment step) (3) of forming the ultra-low refractive index layer 20, as shown in the cross-sectional view of fig. 4. As shown in fig. 4, in the strength-increasing step (aging step) (4), the strength of the ultra-low refractive index layer 20 is increased to produce an ultra-low refractive index layer 21 having increased strength. The strength-improving step (aging step) (4) is not particularly limited, and is, for example, as described above.
Fig. 5 is a schematic view showing another example of a slit die method coating apparatus different from that of fig. 2 and a method for forming the ultra-low refractive index layer using the same. As shown in the drawing, this coating apparatus is the same as the apparatus of fig. 2 except that the strength-increasing zone (aging zone) 130 in which the strength-increasing step (aging step) (4) is performed is provided immediately after the chemical treatment zone 120 in which the chemical treatment step (3) is performed. That is, after the chemical treatment step (3), the strength-increasing step (aging step) (4) is performed in the strength-increasing region (aging region) 130 to increase the adhesive peel strength of the ultralow refractive index layer 20 with respect to the resin film 10, thereby forming the ultralow refractive index layer 21 having an increased adhesive peel strength. The strength-improving step (aging step) (4) may be performed by heating the ultra-low refractive index layer 20 in the above-described manner using, for example, the heat gun (heating means) 131 disposed above and below the substrate 10. The heating temperature, time, and the like are not particularly limited, and are, for example, as described above. Thereafter, the laminated film having the ultra-low refractive index layer 21 formed on the substrate 10 is wound by the winding roll 105 in the same manner as in fig. 3.
Fig. 6 is a schematic view showing another example of a coating apparatus of a micro-gravure method (micro-gravure coating method) different from fig. 3 and a method for forming the porous structure using the same. As shown in the drawing, this coating apparatus is the same as the apparatus of fig. 3 except that it has a strength-increasing zone (aging zone) 230 in which a strength-increasing step (aging step) (4) is performed immediately after a chemical treatment zone 220 in which a chemical treatment step (3) is performed. That is, after the chemical treatment step (3), the strength-increasing step (aging step) (4) is performed in the strength-increasing region (aging region) 230 to increase the adhesive peel strength of the ultralow refractive index layer 20 with respect to the resin film 10, thereby forming the ultralow refractive index layer 21 having an increased adhesive peel strength. The strength-improving step (aging step) (4) may be performed by heating the ultra-low refractive index layer 20 in the above-described manner using, for example, the heat gun (heating means) 231 disposed above and below the substrate 10. The heating temperature, time, and the like are not particularly limited, and are, for example, as described above. Thereafter, the laminated film having the ultra-low refractive index layer 21 formed on the substrate 10 is wound up by the winding roll 251 in the same manner as in fig. 3.
Fig. 7 to 9 show another example of the continuous processing step in the method for forming the ultra-low refractive index layer of the present invention. As shown in the cross-sectional view of fig. 7, this method includes, after a chemical treatment step (e.g., a crosslinking treatment step) (3) of forming the ultra-low refractive index layer 20: an adhesive bonding layer coating step (adhesive bonding layer forming step) (4) of coating an adhesive bonding layer (30) on the ultra-low refractive index layer (20), and an intermediate layer forming step (5) of forming an intermediate layer (22) by reacting the ultra-low refractive index layer (20) with the adhesive bonding layer (30). Except for these, the method of FIGS. 7 to 9 is the same as the method shown in FIGS. 4 to 6. In fig. 7, the intermediate layer forming step (5) also serves as a step of increasing the strength of the ultralow refractive index layer 20 (strength increasing step), and the ultralow refractive index layer 20 is changed to the ultralow refractive index layer 21 having increased strength after the intermediate layer forming step (5). However, the present invention is not limited to this, and the ultra-low refractive index layer 20 may not be changed after the intermediate layer forming step (5), for example. The adhesive layer coating step (adhesive layer forming step) (4) and the intermediate layer forming step (5) are not particularly limited, and are, for example, as described above.
Fig. 8 is a schematic view showing still another example of the slit die method coating apparatus and the method of forming the ultra-low refractive index layer using the same. As shown in the drawing, the coating apparatus is the same as the apparatus of fig. 5 except that the coating apparatus has an adhesive layer coating area 130a for performing an adhesive layer coating step (4) immediately after the chemical treatment area 120 for performing the chemical treatment step (3). In this figure, the intermediate layer forming zone (aging zone) 130 disposed immediately after the adhesive layer coating zone 130a is bonded can be subjected to the same heat treatment as the strength-improving zone (aging zone) 130 of fig. 5 by the heat blowers (heating means) 131 disposed above and below the substrate 10. That is, in the apparatus of fig. 8, after the chemical treatment step (3), a bonding adhesive layer coating step (bonding adhesive layer forming step) (4) is performed, in which an adhesive or bonding agent is applied (coated) on the ultra-low refractive index layer 20 by the bonding adhesive layer coating means 131a in the bonding adhesive layer coating region 130a to form the bonding adhesive layer 30. As described above, instead of applying (painting) an adhesive or an adhesive, bonding (attaching) of an adhesive tape or the like having the adhesive layer 30 may be performed. Further, an intermediate layer forming step (aging step) (5) is performed in the intermediate layer forming region (aging region) 130, and the ultra-low refractive index layer 20 and the adhesive layer 30 are reacted to form the intermediate layer 22. As described above, in this step, the ultra-low refractive index layer 20 becomes the ultra-low refractive index layer 21 having an increased strength. The heating temperature, time, and the like of the heat gun (heating means) 131 are not particularly limited, and are, for example, as described above.
Fig. 9 is a schematic view showing still another example of a coating apparatus of a micro-gravure method (micro-gravure coating method) and a method for forming the porous structure using the same. As shown in the figure, the coating apparatus is the same as the apparatus of fig. 6 except that it has an adhesive layer coating area 230a for performing an adhesive layer coating step (4) immediately after a chemical treatment area 220 for performing a chemical treatment step (3). In this figure, the intermediate layer forming zone (aging zone) 230 disposed immediately after the adhesive layer coating zone 230a is bonded can be subjected to the same heat treatment as the strength-improving zone (aging zone) 230 of fig. 6 by the heat blowers (heating means) 231 disposed above and below the substrate 10. That is, in the apparatus of fig. 9, after the chemical treatment step (3), a bonding adhesive layer coating step (bonding adhesive layer forming step) (4) is performed, in which an adhesive or bonding agent is applied (coated) on the ultra-low refractive index layer 20 by the bonding adhesive layer coating means 231a in the bonding adhesive layer coating region 230a to form the bonding adhesive layer 30. As described above, instead of applying (painting) an adhesive or an adhesive, bonding (attaching) of an adhesive tape or the like having the adhesive layer 30 may be performed. Further, an intermediate layer forming step (aging step) (5) is performed in the intermediate layer forming region (aging region) 230, and the ultra-low refractive index layer 20 and the adhesive layer 30 are reacted to form the intermediate layer 22. As described above, in this step, the ultra-low refractive index layer 20 becomes the ultra-low refractive index layer 21 having an increased strength. The heating temperature, time, and the like by the heat gun (heating means) 231 are not particularly limited, and are, for example, as described above.
[3. optical Member ]
As described above, the optical member of the present invention is characterized by containing the ultralow refractive index layer of the present invention. The optical member of the present invention is characterized by containing the ultralow refractive index layer of the present invention, and the other constitution is not limited at all. The optical member of the present invention may further contain another layer in addition to the ultra-low refractive index layer of the present invention.
As described above, the optical member of the present invention is characterized by containing the ultralow refractive index layer of the present invention as a low reflection layer. The optical member of the present invention is characterized by containing the low reflection layer of the present invention, and the other constitution is not limited at all. The optical member of the present invention may further contain another layer in addition to the ultra-low refractive index layer of the present invention. The optical member of the present invention is, for example, a roll.
Examples
Next, an embodiment of the present invention will be explained. However, the present invention is not limited to the following examples.
(example 1)
In this example, the ultra-low refractive index layer of the present invention was produced as follows.
(1) Gelling of silicon compounds
MTMS (0.95 g) which is a precursor of the silicon compound was dissolved in DMSO (2.2 g). 0.5g of 0.01mol/L oxalic acid aqueous solution was added to the mixture, and MTMS was hydrolyzed by stirring at room temperature for 30 minutes to produce tris (hydroxy) methylsilane.
0.38g of 28% aqueous ammonia and 0.2g of pure water were added to 5.5g of DMSO, and the mixture was further added to the above mixture subjected to hydrolysis treatment, and stirred at room temperature for 15 minutes to gel tris (hydroxy) methylsilane, thereby obtaining a gel-like silicon compound.
(2) Aging treatment
The above-mentioned gelled mixture was directly cultured at 40 ℃ for 20 hours to effect maturation.
(3) Pulverizing treatment
Next, the aged gel-like silicon compound is pulverized into particles having a size of several mm to several cm by using a spatula. 40g of IPA was added thereto, the mixture was allowed to stand at room temperature for 6 hours with gentle stirring, and the solvent and the catalyst in the gel were decanted. After the same decantation process was repeated 3 times, the solvent replacement was completed. Then, the gel-like silicon compound in the mixed solution is subjected to pulverization treatment (high-pressure, media-free pulverization). The pulverization treatment (high-pressure media-free pulverization) was carried out by weighing 1.18g of the gel and 1.14g of IPA in 5cc of a screw bottle using a homogenizer (trade name: UH-50, manufactured by SMT) and then pulverizing the gel for 2 minutes under conditions of 50W and 20 kHz.
The gel-like silicon compound in the mixed solution is pulverized by the pulverization treatment, whereby the mixed solution becomes a sol solution of the pulverized product. The volume average particle diameter showing the particle size unevenness of the pulverized material contained in the mixed solution was confirmed by a dynamic light scattering Nanotrac particle size analyzer (model UPA-EX150, manufactured by Nikkiso Co., Ltd.), and was 0.50 to 0.70. Further, a 0.3 wt% KOH aqueous solution was prepared, and 0.02g KOH was added to 0.5g of the sol solution to prepare a coating solution.
(4) Forming coating film and forming organosilicon porous body coil
Then, the coating liquid was applied to the surface of a polyethylene terephthalate (PET) resin film (length 100m) by a bar coating method to form a coating film. The coating is set to 1mm per surface of the substrate26. mu.L of the above sol solution. The coating film was treated at a temperature of 100 ℃ for 1 minute to complete the film formation of the precursor of the silicone porous body and the crosslinking reaction between the pulverized materials in the precursor, and a roll body was obtained in the winding step. Thereby, a coil of a silicone porous body having a thickness of 1 μm, in which the pulverized materials are chemically bonded to each other, was formed on the base material.
(5) Confirmation of the characteristics of the ultra-low refractive index layer
The porous body formed on the substrate was confirmed to have a refractive index, haze, strength (scratch resistance by Bemcot (registered trademark)), and pore size by the above-described method.
(example 2)
In the gelation of the silicon compound precursor MTMS as a raw material, the conditions were relaxed as follows: a silicone porous body was formed and various properties were confirmed by the same method as in example 1, except that the amount of ammonia water added as a catalyst was reduced to 0.09g, and the culture in the aging step was changed to 40 ℃ for 20 hours and room temperature for 2 hours.
Comparative example 1
A porous body was formed and various properties were confirmed in the same manner as in comparative example 1, except that KOH was not added to the coating solution.
These results are shown in table 1 below.
TABLE 1
Figure BDA0001331726870000361
As shown in table 1 above, it was confirmed that the obtained ultra-low refractive index layer of example 1 having a thickness of 1 μm had a refractive index of 1.3 or less and was equal to that of the air layer, unlike the comparative example. By further performing the bonding treatment, the occurrence of scratches when the roll body is wound can be suppressed, and a long film having a good roll appearance can be obtained. In addition, it was confirmed that the ultra-low refractive index layer had sufficient strength and transparency in spite of having voids due to the porous structure.
(example 3)
In this example, the ultra-low refractive index layer of the present invention was produced as follows.
First, the above "(1) gelation of silicon compound" and "(2) aging treatment" were carried out in the same manner as in example 1. The "(3) pulverization treatment" was carried out in the same manner as in example 1 except that an IPA (isopropyl alcohol) solution of 1.5 wt% of a photobase catalyst (and WPBG266, trade name, manufactured by wako pure chemical industries, ltd.) was added to the sol particle solution instead of the 0.3 wt% KOH aqueous solution to prepare a coating solution. The amount of the IPA solution of the photobase catalyst added was set to 0.031g relative to 0.75g of the sol particle solution. Thereafter, the above "(4) formation of a coating film and formation of a coil of a silicone porous body" were carried out in the same manner as in example 1. The dried porous body obtained as described above was irradiated with UV. The UV irradiation was performed with light having a wavelength of 360nm, and the amount of light irradiation (energy) was set to 500 mJ. Further, after UV irradiation, the ultra-low refractive index layer (silicone porous body coil) of the present example was formed by heat aging at 60 ℃ for 22 hr.
(example 4)
The same operation as in example 2 was carried out except that heat aging was not carried out after UV irradiation, to form an ultra-low refractive index layer of this example.
(example 5)
An ultra-low refractive index layer of the present example was formed in the same manner as in example 2, except that 0.018g of 5 wt% bis (trimethoxy) silane was added to 0.75g of the above sol solution to prepare a coating solution.
(example 6)
An ultra-low refractive index layer according to this example was formed in the same manner as in example 2, except that the amount of the IPA solution of the photobase catalyst added was changed to 0.054g relative to 0.75g of the sol solution.
(example 7)
After the dried porous body was irradiated with UV in the same manner as in example 2, the adhesive side of the PET film coated with an adhesive (adhesive bonding layer) on one side was attached to the porous body at room temperature before heat aging, and then heat aging was carried out at 60 ℃ for 22 hr. Except for this, the same operation as in example 2 was performed to form the ultralow refractive index layer of the present example.
(example 8)
An ultra-low refractive index layer of this example was formed in the same manner as in example 6, except that heat aging was not performed after attaching the PET film.
(example 9)
An ultra-low refractive index layer according to the present example was formed in the same manner as in example 6, except that 0.018g of 5 wt% bis (trimethoxy) silane was added to 0.75g of the above sol solution to prepare a coating solution.
(example 10)
An ultra-low refractive index layer according to this example was formed in the same manner as in example 6, except that the amount of the IPA solution of the photobase catalyst added was changed to 0.054g relative to 0.75g of the sol solution.
The refractive index, adhesive peel strength, and haze of the ultra-low refractive index layers of examples 3 to 10 were measured by the methods described above, and the measurement results are shown in tables 2 and 3 below. However, in the measurement of the adhesive peel strength in examples 7 to 10, since the PET film and the adhesive layer were already laminated on the laminated film rolls, the adhesion of the PET film and the acrylic adhesive agent was omitted.
TABLE 2
Figure BDA0001331726870000381
TABLE 3
Figure BDA0001331726870000382
As shown in tables 2 and 3, the refractive index of the obtained ultra-low refractive index layers of examples 3 to 10 having a thickness of 1 μm was extremely low and 1.14 to 1.16. Further, since the haze values of these ultra-low refractive index layers also showed an extremely low value of 0.4, it was confirmed that the transparency was also extremely high. Further, the ultra-low refractive index layers of examples 3 to 10 were confirmed to have high strength such that they were not easily peeled from other layers of the laminated film roll even when the rolled material body was produced by winding, since the adhesive peel strength was high. Further, it was confirmed that the ultralow refractive index layers of examples 3 to 10 were excellent in scratch resistance and extremely unlikely to be damaged. In examples 3 to 10, since no change was observed by visual observation after the coating solution was stored for 1 week, it was also confirmed that the coating solution was excellent in storage stability, and a stable quality laminated film coil could be efficiently produced.
Industrial applicability
As described above, the ultralow refractive index layer of the present invention exhibits the above-described characteristics, and thus can easily realize a low refractive index that can be a substitute for an air layer, for example. Therefore, it is not necessary to provide an air layer by disposing a plurality of members at a constant distance in order to obtain a low refractive index, and the ultra-low refractive index layer of the present invention can be disposed at a desired position to provide low refractive index. Therefore, the ultralow refractive index layer of the present invention is useful for, for example, an optical member or the like requiring a low refractive index.
Description of the symbols
10 base material
20 ultra low refractive index layer
20' coating film (precursor layer)
20' sol particle liquid
21 ultra low refractive index layer with improved strength
101 delivery roller
102 coating roller
110 oven zone
111 air heater (heating mechanism)
120 chemical treatment zone
121 lamp (light irradiation mechanism) or air heater (heating mechanism)
130a bonding adhesive layer coating area
130 intermediate formation zone
131a adhesive layer coating mechanism
131 air heater (heating mechanism)
105 take-up roll
106 rolls
201 delivery roller
202 reservoir
203 scraper (sector knife)
204 micro-gravure
210 oven zone
211 heating mechanism
220 chemical treatment zone
221 lamp (light irradiation mechanism) or air heater (heating mechanism)
230a bonding adhesive layer coating area
230 intermediate formation zone
231a bonding adhesive layer coating mechanism
231 air heater (heating mechanism)
251 take-up roll

Claims (8)

1. A long laminated film coil characterized by being obtained by laminating an ultra-low refractive index layer having a refractive index of 1.20 or less on a resin film,
the ultra-low refractive index layer has a fine void structure in which particulate constituent units are cross-linked and bonded by a catalyst for performing a dehydration condensation reaction of residual silanol groups,
the particulate constituent unit is a fine-pore particle of a silicon compound,
the ultra-low refractive index layer has a scratch resistance of 60 to 100% by a Bemcot, which is a registered trademark and shows flexibility, and a folding endurance number of 100 times or more by an MIT test.
2. The laminated film roll according to claim 1, wherein the pore has a void size of 2 to 200 nm.
3. The laminated film roll according to claim 1, wherein the ultralow refractive index layer has a void ratio of 40% or more.
4. The laminated film roll as claimed in claim 1, wherein the thickness of the ultra-low refractive index layer is 0.01 to 100 μm.
5. The laminate film roll of claim 1, wherein the ultra-low refractive index layer has a haze representing transparency of less than 5%.
6. The long laminated film roll according to claim 1, wherein the ultralow refractive index layer contains an acid or a base that acts to increase the strength of the ultralow refractive index layer by at least one of light irradiation and heating.
7. A method for manufacturing a long laminated film coil, the method being a method for manufacturing a long laminated film coil in which an ultra-low refractive index layer having a refractive index of 1.20 or less is laminated on a resin film, the method comprising:
a step of preparing a liquid containing a particulate constituent unit forming a fine pore structure;
applying the liquid to a resin film; and
a step of drying the applied liquid,
the particulate constituent unit is a fine-pore particle of a silicon compound,
the step of preparing a liquid further comprises a step of adding a catalyst for causing the constituent units to undergo a dehydration condensation reaction of residual silanol groups to each other to the liquid,
the ultra-low refractive index layer is formed by crosslinking and bonding the particulate constituent units to each other,
the ultra-low refractive index layer has a scratch resistance of 60 to 100% by a Bemcot, which is a registered trademark and shows flexibility, and a folding endurance number of 100 times or more by an MIT test.
8. An optical member comprising the ultralow refractive index layer in the laminated film roll according to any one of claims 1 to 6.
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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1646947A (en) * 2002-04-08 2005-07-27 日东电工株式会社 Light-diffusing sheet, optical device, and image display
JP2014046518A (en) * 2012-08-30 2014-03-17 Asahi Kasei Chemicals Corp Laminate, polarizing plate, optical material, display device and touch panel

Family Cites Families (4)

* Cited by examiner, † Cited by third party
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CN102186668B (en) * 2008-10-17 2014-07-30 日立化成株式会社 Film having low refractive index and method for producing the same, anti-reflection film and method for producing the same, coating liquid set for film having low refractive index, substrate having microparticle-laminated thin film, and optical component
JP2014206702A (en) * 2013-04-16 2014-10-30 富士フイルム株式会社 Polarizing plate and image display device

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1646947A (en) * 2002-04-08 2005-07-27 日东电工株式会社 Light-diffusing sheet, optical device, and image display
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