JP2016190326A - Release sheet and adhesive sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a release sheet and an adhesive sheet, in which increase in a release force can be suppressed even when the sheet is stored under a severe (high temperature) condition.SOLUTION: A release sheet 1 of the present invention includes a substrate 12 and a release agent layer 11, in which the release agent layer 11 is formed of a release agent composition comprising a diene polymer (A) and a poly(4-methyl-1-pentene) resin (B); the content of the poly(4-methyl-1-pentene) resin (B) in the release agent composition is 0.01 part by mass or more and 15.0 parts by mass or less with respect to 100 parts by mass of the diene polymer (A); and the poly(4-methyl-1-pentene) resin (B) has a melting point of 199°C or lower. Preferably, the release agent layer has a surface free energy of 32 mJ/mor less measured by a contact angle method.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a release sheet and an adhesive sheet.

  Electrical components such as relays, various switches, connectors, motors, and hard disks are widely used in various products.

  An adhesive sheet is attached to such an electrical component for the purpose of temporary fixing during assembly, content display of the component, and the like.

  Such an adhesive sheet is normally comprised by the adhesive sheet base material and the adhesive layer, and is affixed on the peeling sheet before adhering to an electrical component.

  A release agent layer is provided on the surface of the release sheet (contact surface with the pressure-sensitive adhesive layer) for the purpose of improving peelability. Conventionally, a silicone resin has been used as a constituent material of the release agent layer (see, for example, Patent Document 1).

  However, it is known that when such a release sheet is attached to an adhesive sheet, a silicone compound such as a low molecular weight silicone resin, siloxane, or silicone oil in the release sheet moves to the adhesive layer of the adhesive sheet. Moreover, although the said peeling sheet is wound up in roll shape after manufacture, the back surface and release agent layer of a peeling sheet contact at this time, and the silicone compound in silicone resin transfers to the back surface of a peeling sheet. It is also known that the silicone compound transferred to the back surface of the release sheet is transferred again to the surface of the pressure-sensitive adhesive sheet when the pressure-sensitive adhesive body is wound into a roll at the time of manufacturing the pressure-sensitive adhesive body. For this reason, when the adhesive sheet stuck to such a peeling sheet is stuck to the said electrical component, the silicone compound which moved to the surface of this adhesive layer or an adhesive sheet will vaporize gradually after that. The vaporized silicone compound is deposited on the surface of the electrical contact portion by, for example, an arc generated in the vicinity of the electrical contact portion of the electrical component to form a fine silicone compound layer or a silicon oxide compound layer derived from the silicone compound. It is known to do.

  Thus, when a silicon compound or a silicon oxide-based compound derived from a silicone compound is deposited on the surface of the electrical contact portion, poor conductivity may be caused.

  In particular, when adhered to a hard disk device, the silicone compound transferred to the surface of the pressure-sensitive adhesive layer or pressure-sensitive adhesive sheet gradually vaporizes, and the silicon compound or the silicon oxide compound derived from the silicone compound becomes the surface of the magnetic head or disk. The deposition of such fine silicone compounds and silicon oxide compounds may adversely affect the reading and writing of the hard disk.

  In order to solve such problems, development of a non-silicone release agent that does not contain a silicone compound has been attempted (for example, see Patent Document 2). However, a release sheet composed of a conventional non-silicone release agent has a tendency to undergo heavy release.

  For the purpose of improving such heavy release, a release sheet using a polybutadiene compound has been developed (see, for example, Patent Document 3).

  However, the release sheet of Patent Document 3 has a problem of heavy release when stored under high temperature conditions in order to confirm durability, storage stability, and the like after being bonded to the pressure-sensitive adhesive layer.

JP-A-6-336574 JP 2004-162048 A Patent No. 5043025

  An object of the present invention is to provide a release sheet and an adhesive sheet that can suppress an increase in peel force even when stored under durable (high temperature) conditions.

Such an object is achieved by the present inventions (1) to (12) below.
(1) A release sheet having a substrate and a release agent layer,
The release agent layer is formed of a release agent composition containing a diene polymer (A) and a poly (4-methyl-1-pentene) resin (B),
The content of the poly (4-methyl-1-pentene) resin (B) in the release agent composition is 0.01 parts by mass or more and 15 parts by mass with respect to 100 parts by mass of the diene polymer (A). 0.0 parts by mass or less,
The release sheet, wherein the poly (4-methyl-1-pentene) resin (B) has a melting point of 199 ° C. or lower.

(2) The release sheet according to (1), wherein the surface free energy of the release agent layer measured by a contact angle method is 32 mJ / m ² or less.

  (3) The release sheet according to (1) or (2), wherein the ratio of C element on the surface of the release agent layer in XPS surface elemental analysis is 90 atomic% or more.

  (4) The release sheet according to any one of (1) to (3), wherein a ratio of Si element on the surface of the release agent layer in XPS surface elemental analysis is 0.5 atomic% or less.

  (5) The release sheet according to any one of (1) to (4), wherein an average thickness of the release agent layer is 0.01 μm or more and 1.0 μm or less.

  (6) The melt flow rate of the poly (4-methyl-1-pentene) resin (B) measured under the conditions of a heating temperature of 230 ° C. and a load of 2.16 kgf in accordance with ASTM D1238 is 0.00. The release sheet according to any one of (1) to (5), which is 1 g / 10 min or more and 100.0 g / 10 min or less.

  (7) The release sheet according to any one of (1) to (6), wherein a primer layer is provided between the substrate and the release agent layer.

(8) an adhesive sheet substrate;
An adhesive layer laminated on one side of the adhesive sheet substrate;
A release sheet laminated on the adhesive surface of the adhesive layer,
The pressure-sensitive adhesive sheet, wherein the release sheet is the release sheet according to any one of (1) to (7).

(9) an adhesive sheet substrate;
Two adhesive layers laminated on both sides of the adhesive sheet substrate;
Two release sheets laminated on the adhesive surfaces of the two adhesive layers,
At least one of the two release sheets is the release sheet according to any one of (1) to (7).

(10) an adhesive layer;
Two release sheets laminated on both sides of the pressure-sensitive adhesive layer,
At least one of the two release sheets is the release sheet according to any one of (1) to (7).

  (11) The pressure-sensitive adhesive sheet according to any one of (8) to (10), wherein the pressure-sensitive adhesive layer is composed of an acrylic pressure-sensitive adhesive.

  (12) The pressure-sensitive adhesive sheet according to (11), wherein the acrylic pressure-sensitive adhesive has a carboxy group.

  According to the present invention, it is possible to provide a release sheet and an adhesive sheet that can suppress an increase in peel force even when stored under high temperature conditions in order to confirm durability, storage stability, and the like. Can do.

It is a longitudinal cross-sectional view which shows 1st Embodiment of the peeling sheet of this invention. It is a longitudinal cross-sectional view which shows 2nd Embodiment of the peeling sheet of this invention. It is sectional drawing which shows 1st Embodiment of the adhesive sheet of this invention. It is a longitudinal cross-sectional view which shows 2nd Embodiment of the adhesive sheet of this invention. It is a longitudinal cross-sectional view which shows 3rd Embodiment of the adhesive sheet of this invention.

Hereinafter, the present invention will be described in detail based on preferred embodiments.
<First embodiment of release sheet>
FIG. 1 is a longitudinal sectional view showing a first embodiment of the release sheet of the present invention. In the following description, the upper side in the figure is referred to as “upper” or “upper”, and the lower side is referred to as “lower” or “lower”.

Hereinafter, each sheet will be described in detail.
As shown in FIG. 1, the release sheet 1 has a configuration in which a release agent layer 11 is formed on a substrate 12.

The substrate 12 has a function of supporting the release agent layer 11.
The substrate 12 is made of, for example, polyethylene terephthalate film, polybutylene terephthalate film, polyester film such as polyethylene naphthalate, polyolefin film such as polyethylene, polypropylene film or polymethylpentene film, plastic film such as polycarbonate film, aluminum, stainless steel, etc. It is composed of metal foil, glassine paper, fine paper, coated paper, impregnated paper, synthetic paper, and other paper, and paper obtained by laminating a thermoplastic resin such as polyethylene on these paper base materials.

  The average thickness of the substrate 12 is not particularly limited, but is preferably 5 μm or more, and more preferably 10 μm or more. Further, the average thickness of the substrate 12 is not particularly limited, but is preferably 300 μm or less, and more preferably 200 μm or less.

By providing the release agent layer 11 on the substrate 12, the pressure-sensitive adhesive layer can be released from the release sheet 1.
The release agent layer 11 is formed by curing the release agent composition.

  In the release sheet of the present invention, the release agent composition forming the release agent layer comprises a diene polymer (A) and a poly (4-methyl-1-pentene) resin (B). It is.

  In the release sheet of the present invention, the content of the poly (4-methyl-1-pentene) -based resin (B) in the release agent composition is 0. 0 parts by mass with respect to 100 parts by mass of the diene polymer. 01 parts by mass or more and 15.0 parts by mass or less.

  Furthermore, in the release sheet of the present invention, the poly (4-methyl-1-pentene) resin (B) has a melting point of 199 ° C. or lower.

  By having the characteristics as described above, an increase in peeling force can be suppressed even when stored under high temperature conditions in order to confirm durability, storage stability, and the like. That is, the surface free energy on the surface of the release agent layer can be reduced by adding a predetermined amount of the poly (4-methyl-1-pentene) resin (B) to the diene polymer (A). And the fall of this surface free energy can reduce the interaction which arises in the interface of an adhesive layer and a releasing agent layer, and can suppress the peeling force raise in high temperature conditions.

Hereinafter, each component will be described in detail.
[Diene polymer (A)]
The release agent composition that forms the release agent layer 11 contains a diene polymer (A). Thereby, the peeling performance of the peeling sheet 1 can be made high.

  Examples of the diene polymer (A) include polybutadiene rubber, polyisoprene rubber, styrene-butadiene rubber, and styrene-isoprene rubber. Among these, it is particularly preferable to use polybutadiene rubber (particularly 1,4-polybutadiene rubber). Thereby, the peeling performance of the peeling sheet 1 can be made higher. Moreover, the peeling sheet 1 which does not have a bad influence on electrical components, such as a relay, various switches, a connector, a motor, can be provided.

  The diene polymer (A) preferably contains cis 1,4-butadiene as a monomer. Thereby, the peeling performance of the peeling sheet 1 can further be improved.

  Further, the content of cis 1,4-butadiene as a monomer of the diene polymer (A) is preferably 90 mol% or more, and more preferably 93 mol% or more. Further, the content of cis 1,4-butadiene as a monomer of the diene polymer (A) is more preferably 99 mol% or less. Thereby, the peeling performance of the peeling sheet 1 can be made higher.

  Further, the mass average molecular weight of the diene polymer before curing is preferably 100,000 or more, and more preferably 300,000 or more. Further, the mass average molecular weight of the diene polymer before curing is preferably 600,000 or less, and more preferably 550,000 or less. Thereby, the peeling performance of the peeling sheet 1 can be improved more effectively.

[Poly (4-methyl-1-pentene) resin (B)]
The release agent composition for forming the release agent layer 11 contains a poly (4-methyl-1-pentene) resin (B).

  The poly (4-methyl-1-pentene) resin (B) used in the present invention is a resin having a poly (4-methyl-1-pentene) skeleton and has a melting point of 199 ° C. or lower. By adding a predetermined amount of such a poly (4-methyl-1-pentene) resin (B) to the diene polymer (A), a poly (4-methyl-1-pentene) resin (B ) Can be appropriately unevenly distributed on the surface of the release agent layer 11 (the surface of the release agent layer 11 opposite to the substrate 12), and the surface free energy on the surface of the release agent layer 11 can be reduced. As a result, the interaction generated at the interface between the pressure-sensitive adhesive layer and the release agent layer 11 can be reduced, and an increase in the peel force under high temperature conditions can be suppressed.

  The melting point of the poly (4-methyl-1-pentene) resin (B) used in the present invention is 199 ° C. or lower, more preferably 190 ° C. or lower. When the melting point of the poly (4-methyl-1-pentene) -based resin (B) exceeds the upper limit, the solubility in components constituting the release agent composition such as a diene polymer (A) or a solvent is lowered. In addition, it becomes difficult to form the release agent layer 11. Moreover, it is preferable that melting | fusing point of poly (4-methyl- 1-pentene) type-resin (B) is 110 degreeC or more. Thereby, the storage stability at the time of apply | coating a releasing agent composition can be improved.

  The melt flow rate of the poly (4-methyl-1-pentene) resin (B) measured under the conditions of a heating temperature of 230 ° C. and a load of 2.16 kgf in accordance with ASTM D1238 is 0.1 g / It is preferably 10 min or more, more preferably 1.0 g / 10 min or more, and even more preferably 2.0 g / 10 min or more. The melt flow rate of the poly (4-methyl-1-pentene) resin (B) is preferably 100.0 g / 10 min or less, more preferably 50.0 g / 10 min or less. More preferably, it is 0.0 g / 10 min or less.

  In the present invention, the content of the poly (4-methyl-1-pentene) resin (B) is 0.01 parts by mass or more with respect to 100 parts by mass of the diene polymer (A). It is preferably 05 parts by mass or more, more preferably 0.1 parts by mass or more, and particularly preferably 0.5 parts by mass or more. In the present invention, the content of the poly (4-methyl-1-pentene) resin (B) is 15.0 parts by mass or less with respect to 100 parts by mass of the diene polymer (A). The amount is preferably 12.0 parts by mass or less, more preferably 9.0 parts by mass or less, and particularly preferably 7.0 parts by mass or less. When the content of the poly (4-methyl-1-pentene) -based resin (B) is less than the lower limit, an increase in peeling force cannot be suppressed under high temperature conditions. On the other hand, when the content of the poly (4-methyl-1-pentene) -based resin (B) exceeds the upper limit value, the peeling force of the release agent layer 11 in a normal state increases, and it is applied to the base sheet. When dried, there is a problem that the resin precipitates and whitens.

[Other ingredients]
In addition to the above, the release agent composition for forming the release agent layer 11 includes other additives such as other resin components, antioxidants, plasticizers, stabilizers, crosslinking agents, sensitizers, radical initiators, and the like. May be included.

  In addition, it does not specifically limit as a hardening method of the above releasing agent composition, For example, methods, such as irradiation of active energy rays, such as an ultraviolet-ray and an electron beam, a heating, can be used.

  The average thickness of the release agent layer 11 is not particularly limited, but is preferably 0.01 μm or more, more preferably 0.03 μm or more, and further preferably 0.05 μm or more. The average thickness of the release agent layer 11 is preferably 1.0 μm or less, more preferably 0.8 μm or less, and further preferably 0.5 μm or less. When the average thickness of the release agent layer 11 is less than the lower limit, sufficient release performance may not be obtained when the pressure-sensitive adhesive sheet is peeled from the release sheet. On the other hand, when the average thickness of the release agent layer 11 exceeds the above upper limit value, the release agent layer 11 when the release sheet is rolled up becomes easy to block the back side of the release sheet, and the release agent layer 11 is peeled off. Performance may be reduced due to blocking.

Moreover, surface free energy measured release agent layer 11, the contact angle method is preferably at 32 mJ / ^{m 2} or less, more preferably at 30 mJ / ^{m 2} or less, is 28 mJ / ^{m 2} or less Is more preferable. Thereby, the wettability of an adhesive is suppressed. As a result, heavy peeling can be prevented.

Moreover, surface free energy measured release agent layer 11, the contact angle method is preferably at 10 mJ / ^{m 2} or more, more preferably 15 mJ / ^{m 2} or more, at 20 mJ / ^{m 2} or more Is more preferable. Thereby, the repelling of an adhesive solution at the time of apply | coating an adhesive solution can be suppressed.

  In the present specification, a contact angle meter (manufactured by Kyowa Interface Science Co., Ltd., DM-701) was used for contact angle measurement by the contact angle method. And the contact angle with respect to three liquids of water, diiodomethane, and dibromonaphthalene was measured (23 degreeC50% RH), and the surface free energy was computed by the Kitazaki and the field method.

  Further, the ratio of the C element on the surface of the release agent layer 11 in the XPS surface elemental analysis is preferably 90 atomic% or more, more preferably 95 atomic% or more, and further preferably 98 atomic% or more. . Thereby, the interaction which arises in the interface of an adhesive layer and the releasing agent layer 11 can be reduced more effectively, and the peeling force raise in high temperature conditions can be suppressed more effectively.

  Further, the ratio of the Si element on the surface of the release agent layer 11 in the XPS surface elemental analysis is preferably 0.5 atomic% or less. This more reliably prevents the silicone compound and the like from transferring from the release sheet 1 to the pressure-sensitive adhesive layer. As a result, after the pressure-sensitive adhesive layer is adhered to the adherend, the silicone compound and the like are more reliably prevented from being released from the pressure-sensitive adhesive layer. Therefore, even if the adherend is an electronic device such as a relay, the pressure-sensitive adhesive layer is particularly difficult to adversely affect the adherend.

  In the present specification, PHI Quantera SXM (manufactured by ULVAC-PHI) was used for XPS measurement on the surface of the release agent layer 11. Measurement is performed at a photoelectron take-off angle of 45 ° using monochromatic Al Kα as the X-ray source, and the element ratio of carbon, oxygen and silicon existing on the surface is calculated.

<Second embodiment of release sheet>
Next, 2nd Embodiment of the peeling sheet of this invention is described.

  FIG. 2 is a longitudinal sectional view showing a second embodiment of the release sheet of the present invention. In the following description, the upper side in the figure is referred to as “upper” or “upper”, and the lower side is referred to as “lower” or “lower”.

  In the following description, the release sheet of the second embodiment will be described with a focus on differences from the above-described embodiment, and description of similar matters will be omitted. Moreover, in FIG. 2, the same code | symbol is attached | subjected about the structure similar to 1st Embodiment mentioned above.

  As shown in FIG. 2, the release sheet 10 of the present embodiment includes a release agent layer 11, a base material 12, and a primer layer 13 provided between the release agent layer 11 and the base material 12. ing.

  By providing the primer layer 13, the adhesion between the release agent layer 11 and the substrate 12 can be improved.

  Examples of the material constituting the primer layer 13 include polyurethane resins such as polyurethane elastomers and modified polyurethane elastomers, acrylic resins such as (meth) acrylate esters, polyolefin resins such as ethylene vinyl acetate copolymers, and styrene butadiene. Examples thereof include styrene resins such as rubber, rubber resins such as butyl rubber, polyisobutylene rubber and polyisoprene rubber, and natural resins such as natural rubber. Among these, it is particularly preferable to use a polyurethane-based resin because it has solvent resistance to the organic solvent used in the release agent composition and excellent rubber elasticity.

  The average thickness of the primer layer 13 is not particularly limited, but is preferably 0.01 μm or more, and more preferably 0.05 μm or more. Further, the average thickness of the primer layer 13 is preferably 3 μm or less, and more preferably 1 μm or less. Adhesiveness between the release agent layer 11 and the substrate 12 can be improved by setting the average thickness of the primer layer 13 to the lower limit value or more. Moreover, the blocking at the time of winding a base material with a primer layer once can be suppressed by making average thickness of the primer layer 13 below the said upper limit.

<First embodiment of adhesive sheet>
Hereinafter, 1st Embodiment of an adhesive sheet is described.
FIG. 3 is a cross-sectional view showing a first embodiment of the pressure-sensitive adhesive sheet of the present invention.

  As shown in FIG. 3, the pressure-sensitive adhesive sheet 100 includes a pressure-sensitive adhesive sheet main body 2 composed of a pressure-sensitive adhesive sheet base material 22, and a pressure-sensitive adhesive layer 21 laminated on one side of the pressure-sensitive adhesive sheet base material 22. It is the single-sided adhesive sheet which has the said peeling sheet 1 laminated | stacked on the adhesive surface.

  The pressure-sensitive adhesive sheet substrate 22 has a function of supporting the pressure-sensitive adhesive layer 21, for example, a polyethylene terephthalate film, a polybutylene terephthalate film, a polyethylene film, a polypropylene film, a polymethylpentene film, a plastic film such as a polycarbonate film, It is composed of a simple substance or a composite such as metal foil such as aluminum and stainless steel, synthetic paper, dust-free paper, high-quality paper, art paper, coated paper, glassine paper and the like.

  Among them, in particular, the pressure-sensitive adhesive sheet substrate 22 is composed of a polyester film such as a polyethylene terephthalate film or a polybutylene terephthalate film, a plastic film such as a polypropylene film, or a so-called dust-free paper (for example, Japanese Patent Publication No. 6-11959) with less dust generation. It is preferable. When the pressure-sensitive adhesive sheet base material 22 is made of a plastic film or dust-free paper, dust and the like are hardly generated during processing and use, and electronic devices such as relays are hardly adversely affected. Further, when the pressure-sensitive adhesive sheet substrate 22 is made of a plastic film or dust-free paper, cutting or punching during processing becomes easy. Moreover, when using a plastic film for a base material, it is more preferable that this plastic film is a polyethylene terephthalate film. The polyethylene terephthalate film has the advantages that it generates less dust and generates less gas during heating.

  In the case of a single-sided pressure-sensitive adhesive sheet, among those described above, it is preferable to use a material having printability / printability on the surface as the pressure-sensitive adhesive sheet substrate 22.

  In the case of a single-sided pressure-sensitive adhesive sheet, the surface of the pressure-sensitive adhesive sheet substrate 22 is preferably subjected to surface treatment for the purpose of improving the adhesion of printing and printing.

  The average thickness of the pressure-sensitive adhesive sheet substrate 22 is not particularly limited, but is preferably 5 μm or more, and more preferably 10 μm or more. Moreover, it is preferable that the average thickness of the adhesive sheet base material 22 is 300 micrometers or less, and it is more preferable that it is 200 micrometers or less.

The pressure-sensitive adhesive layer 21 is composed of a pressure-sensitive adhesive composition mainly containing a pressure-sensitive adhesive.
Examples of the pressure sensitive adhesive include acrylic pressure sensitive adhesive, polyester pressure sensitive adhesive, and urethane pressure sensitive adhesive.

  For example, when the pressure-sensitive adhesive is an acrylic pressure-sensitive adhesive, the main monomer component that provides tackiness, the comonomer component that provides adhesiveness and cohesion, and the functional group-containing monomer component for improving the cross-linking point and adhesion are mainly used. It can be composed of a polymer or a copolymer.

  In the following, for example, “(meth) acrylic acid” indicates both “acrylic acid” and “methacrylic acid”, and the same applies to other similar terms.

  Examples of the main monomer component include ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, pentyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, Examples include (meth) acrylic acid alkyl esters such as octyl (meth) acrylate.

  Examples of comonomer components include methyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, tridecyl (meth) acrylate, benzyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, and cyclohexyl (meth). Examples include acrylate, benzyl (meth) acrylate, vinyl acetate, styrene, acrylonitrile and the like.

  Examples of the functional group-containing monomer component include monomers having a carboxy group such as (meth) acrylic acid, maleic acid, itaconic acid, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4- Monomers having a hydroxy group such as hydroxybutyl (meth) acrylate and N-methylol (meth) acrylamide, (meth) acrylamide, glycidyl (meth) acrylate and the like can be mentioned. Among these, when the monomer which has a carboxy group with the tendency to make heavy peeling is used, the effect of the peeling sheet 1 (release sheet of this invention) is exhibited more notably.

  The content of the functional group-containing monomer component is preferably 0.1% by mass or more, more preferably 0.5% by mass with respect to all the structural units (100% by mass) of the acrylic polymer constituting the acrylic pressure-sensitive adhesive. % Or more, more preferably 1% by mass or more, and still more preferably 2% by mass or more. The content of the functional group-containing monomer component is preferably 50% by mass or less, more preferably 40% by mass or less, with respect to the total structural units (100% by mass) of the acrylic polymer constituting the acrylic pressure-sensitive adhesive. More preferably, it is 30 mass% or less, More preferably, it is 20 mass% or less.

  By including these components, the adhesive force and cohesive force of the pressure-sensitive adhesive composition are improved. Moreover, since such an acrylic adhesive normally does not have an unsaturated bond in a molecule | numerator, the improvement with respect to light or oxygen can be aimed at. Furthermore, a pressure-sensitive adhesive composition having quality and characteristics according to the application can be obtained by appropriately selecting the type and molecular weight of the monomer.

  As such a pressure-sensitive adhesive composition, any of a crosslinked type that undergoes crosslinking treatment and a non-crosslinked type that does not undergo crosslinking treatment may be used, but a crosslinked type is more preferred. When the cross-linked type is used, the pressure-sensitive adhesive layer 21 having a better cohesive force can be formed.

  Examples of the crosslinking agent used in the crosslinking adhesive composition include an epoxy compound, an isocyanate compound, a metal chelate compound, a metal alkoxide, a metal salt, an amine compound, a hydrazine compound, and an aldehyde compound.

  Moreover, in the adhesive composition used for this invention, various additives, such as a plasticizer, a tackifier, and a stabilizer, may be contained as needed.

  The average thickness of the pressure-sensitive adhesive layer 21 is not particularly limited, but is preferably 1 μm or more, more preferably 5 μm or more, and particularly preferably 10 μm or more. Moreover, it is preferable that the average thickness of the adhesive layer 21 is 200 micrometers or less, and it is more preferable that it is 100 micrometers or less.

<Second Embodiment of Adhesive Sheet>
Next, 2nd Embodiment of the adhesive sheet of this invention is described.

  FIG. 4 is a longitudinal sectional view showing a second embodiment of the pressure-sensitive adhesive sheet of the present invention. In the following description, the upper side in the figure is referred to as “upper” or “upper”, and the lower side is referred to as “lower” or “lower”.

  In the following description, the pressure-sensitive adhesive sheet of the second embodiment will be described with a focus on the differences from the above-described embodiment, and the description of the same matters will be omitted. Moreover, in FIG. 4, the same code | symbol is attached | subjected about the structure similar to embodiment mentioned above.

  As shown in FIG. 4, the pressure-sensitive adhesive sheet 110 of this embodiment is a double-sided pressure-sensitive adhesive sheet having a pressure-sensitive adhesive sheet body 2 ′, a release sheet 1, and a release sheet 1 ′.

  The pressure-sensitive adhesive sheet main body 2 ′ has a pressure-sensitive adhesive sheet base material 22 ′, and a pressure-sensitive adhesive layer 21 </ b> A and a pressure-sensitive adhesive layer 21 </ b> B laminated on both surfaces of the pressure-sensitive adhesive sheet base material 22 ′.

  The pressure-sensitive adhesive sheet base material 22 ′ has a function of supporting the pressure-sensitive adhesive layers 21 </ b> A and B, and can be made of the same material as the pressure-sensitive adhesive sheet base material 22 described above.

  The average thickness of the pressure-sensitive adhesive sheet substrate 22 ′ is not particularly limited, but is preferably 2 μm or more, more preferably 5 μm or more, and particularly preferably 10 μm or more. The average thickness of the pressure sensitive adhesive sheet base material 22 'is preferably 300 μm or less, and more preferably 200 μm or less.

The pressure-sensitive adhesive layers 21A and B are composed of a pressure-sensitive adhesive composition containing a pressure-sensitive adhesive as a main ingredient.
As the pressure-sensitive adhesive composition, the pressure-sensitive adhesive composition described in the column of the first embodiment of the pressure-sensitive adhesive sheet can be used.

  The average thickness of the pressure-sensitive adhesive layers 21A and B is not particularly limited, but is preferably 1 μm or more, more preferably 5 μm or more, and particularly preferably 10 μm or more. In addition, the average thickness of the pressure-sensitive adhesive layers 21A and 21B is preferably 200 μm or less, and more preferably 100 μm or less.

  As shown in FIG. 4, the release sheet 1 and the release sheet 1 'are laminated on the pressure-sensitive adhesive layer 21A and the pressure-sensitive adhesive layer 21B, respectively.

  The release sheets 1 and 1 ′ have release agent layers 11 and 11 ′ and base materials 12 and 12 ′, respectively.

  The release agent layer 11 is formed of a cured product of the release agent composition described above. On the other hand, the release agent layer 11 ′ of the release sheet 1 ′ may be formed of a cured product of the release agent composition described above, or may be cured by a release agent composition different from the release agent composition described above. It may be formed of an object.

  When the release agent layer 11 ′ is formed of a cured product of a release agent composition different from the release agent composition described above, the release force of the release sheet 1 from the pressure-sensitive adhesive layer 21A is that of the release sheet 1 ′. It is preferably different from the peeling force from the pressure-sensitive adhesive layer 21B. Thereby, it is possible to prevent the release sheet 1 from being unintentionally peeled off from the pressure-sensitive adhesive layer 21 </ b> A when the release sheet 1 ′ is peeled off.

  Moreover, even if it is the case where the release agent composition which comprises release agent layer 11 and release agent layer 11 'is the same or different, the peeling force with respect to the said adhesive layer of release sheet 1 and release sheet 1' The difference is preferably 50 mN / 20 mm or more, more preferably 80 mN / 20 mm or more, and further preferably 100 mN / 20 mm or more. Further, the difference in the peeling force is more preferably 700 mN / 20 mm or less, and particularly preferably 450 mN / 20 mm or less. Thereby, when peeling a peeling sheet with the smaller peeling force, it can prevent more effectively that the other peeling sheet peels off from an adhesive layer unintentionally.

  Moreover, the peeling force with respect to each adhesive layer of release sheet 1 and release sheet 1 ′ is preferably 1000 mN / 20 mm or less, more preferably 800 mN / 20 mm or less, and even more preferably 600 mN / 20 mm or less. preferable. The peeling force is more preferably 10 mN / 20 mm or more, and particularly preferably 30 mN / 20 mm or more. Thereby, it becomes possible to peel a peeling sheet more easily.

  Specifically, the peel force is measured by cutting a double-sided pressure-sensitive adhesive sheet into a width of 20 mm and a length of 200 mm in an environment of 23 ° C. and 50% RH, and using a tensile tester to attach one side of the double-sided tape. Etc., and the peeling sheet is pulled by 180 ° at a speed of 0.3 m / min.

<Third embodiment of the pressure-sensitive adhesive sheet>
Next, 3rd Embodiment of the adhesive sheet of this invention is described.

  FIG. 5 is a longitudinal sectional view showing a third embodiment of the pressure-sensitive adhesive sheet of the present invention. In the following description, the upper side in the figure is referred to as “upper” or “upper”, and the lower side is referred to as “lower” or “lower”.

  In the following description, the pressure-sensitive adhesive sheet according to the third embodiment will be described with a focus on differences from the above-described embodiment, and description of similar matters will be omitted. Moreover, in FIG. 5, the same code | symbol is attached | subjected about the structure similar to embodiment mentioned above.

  The pressure-sensitive adhesive sheet 120 according to this embodiment is the same as the second embodiment described above in that it is a double-sided pressure-sensitive adhesive sheet as shown in FIG. This is different from the above-described embodiment.

  Even if it is a double-sided adhesive sheet which does not have such an adhesive sheet base material, heavy peeling can be suppressed.

<The manufacturing method of the adhesive sheet 100>
Next, an example of the manufacturing method of the adhesive sheet 100 according to the first embodiment will be described.

  The release sheet 1 can be prepared by preparing the base material 12, applying the above-described release agent composition on the base material 12, and then curing the base material 12 to form the release agent layer 11.

  The curing method of the release agent composition is not particularly limited, and for example, methods such as irradiation with active energy rays such as ultraviolet rays and electron beams, heating, and the like can be used. Thereby, the release agent layer 11 can be formed more easily.

  Examples of the method for applying the release agent composition onto the base material 12 include existing methods such as gravure coating, bar coating, spray coating, spin coating, knife coating, roll coating, and die coating. Can be used.

  Next, the pressure-sensitive adhesive composition is applied to the release agent layer 11 of the release sheet 1 to form the pressure-sensitive adhesive layer 21.

  Examples of the method for applying the pressure-sensitive adhesive composition to the release agent layer 11 include existing methods such as gravure coating, bar coating, spray coating, spin coating, knife coating, roll coating, and die coating. Can be used.

  Examples of the form of the pressure-sensitive adhesive composition in this case include a solvent type, an emulsion type, and a hot melt type.

  Then, the adhesive sheet 100 can be obtained by bonding the adhesive sheet substrate 22 to the formed adhesive layer 21.

<The manufacturing method of the adhesive sheet 110>
Next, an example of the manufacturing method of the adhesive sheet 110 according to the second embodiment will be described.

  First, the release sheet 1 and the release sheet 1 ′ are produced in the same manner as in the method for manufacturing the pressure-sensitive adhesive sheet 100.

  Next, an adhesive composition is applied to the release agent layer 11 of the release sheet 1 to form an adhesive layer 21A.

Next, adhesive sheet base material 22 'is bonded to the formed adhesive layer 21A.
Next, in the same manner as described above, the pressure-sensitive adhesive composition is applied to the release agent layer 11 ′ of the release sheet 1 ′ to form the pressure-sensitive adhesive layer 21B.

  Thereafter, the pressure-sensitive adhesive sheet 110 can be obtained by bonding the side of the pressure-sensitive adhesive sheet substrate 22 ′ on which the pressure-sensitive adhesive layer 21 </ b> A is not laminated and the pressure-sensitive adhesive layer 21 </ b> B formed on the release sheet 1 ′.

<Method for producing adhesive sheet 120>
Next, an example of the manufacturing method of the adhesive sheet 120 according to the third embodiment will be described.

  First, the release sheet 1 and the release sheet 1 ′ are produced in the same manner as in the method for manufacturing the pressure-sensitive adhesive sheet 100.

  Next, an adhesive composition is applied to the release agent layer 11 of the release sheet 1 to form an adhesive sheet body 2 ″.

  Then, the adhesive sheet 120 can be obtained by bonding the release sheet 1 ′ to the formed adhesive sheet body 2 ″.

  As mentioned above, although preferable embodiment of the peeling sheet and adhesive sheet of this invention was described, this invention is not limited to these.

  In the above-described embodiment, the release sheet has been described as being composed of a release agent layer and a base material. However, the release agent layer has a function as a base material like a resin film. Also good.

Moreover, the manufacturing method of the adhesive sheet of this invention is not limited to the manufacturing method mentioned above.
Moreover, the uses of the release sheet and the adhesive sheet of the present invention are not limited to electrical components such as the relay, various switches, connectors, motors, and hard disks as described above.

Next, specific examples of the present invention will be described.
1. Production of release sheet (Example 1)
(Preparation of primer layer)
Polyester polyol (manufactured by DIC Corporation, trade name: Crisbon 5150S, solid content 50 mass%) 100 mass on a polyethylene terephthalate film (Mitsubishi Resin Co., Ltd., trade name: Diafoil T-100), thickness: 50 μm) And a solution obtained by diluting 5 parts by mass of an isocyanate compound (manufactured by DIC Corporation, trade name: Crisbon NX) with a methyl ethyl ketone solvent to a solid content concentration of 1% by mass so that the film thickness after drying is about 0.1 μm It was applied to.

  Thereafter, the formed coating film was dried at 100 ° C. for 1 minute to form a primer layer composed of a polyurethane resin.

(Preparation of release agent layer)
Poly (4-methyl-1) dissolved in 100 parts by mass of polybutadiene (manufactured by Ube Industries, Ltd., trade name: UBEPOL-BR150, mass average molecular weight: 540,000) in a mixed solvent of methylcyclohexane / methylisobutylketone = 80/20 -Solid content of a pentene) resin (Mitsui Chemicals Co., Ltd., melting point: 180 ° C., melt flow rate: 4 g / 10 min measured under a heating temperature of 230 ° C. and a load of 2.16 kgf in accordance with ASTM D1238) 1.0 parts by weight of a 10% concentration solution (0.10 parts by weight as a solid content) and 1 part by weight of a hindered phenol antioxidant (Ciba Specialty Chemicals, trade name: Irganox HP2251) A release agent composition diluted with a toluene solvent to a solid content concentration of 1.5% by mass was obtained.

  The obtained release agent composition was applied on the primer layer and dried at 100 ° C. for 1 minute.

Next, an ultraviolet ray is applied to the coating layer at a conveyor speed of 40 m / min (ultraviolet irradiation condition: 100 mJ / cm ² ) by a belt conveyor type ultraviolet irradiation apparatus with one fusion H bulb 240 w / cm as an electrodeless lamp. Irradiation and curing were performed to obtain a release sheet having a release agent layer having a thickness of 0.1 μm.

  The content of cis 1,4-butadiene as a monomer in the polybutadiene of this example was 98 mol%. The monomer content was measured by an infrared absorption spectrum method (ATR method).

(Examples 2-6, Comparative Examples 1-3)
A release sheet was prepared in the same manner as in Example 1 except that the types and amounts of each component were changed as shown in Table 1.

  In Comparative Example 2, since a poly (4-methyl-1-pentene) -based resin was deposited at the time of producing the release sheet, the release sheet could not be produced.

  In Comparative Example 3, the poly (4-methyl-1-pentene) -based resin was not dissolved in the methylcyclohexane / methylisobutyl ketone = 80/20 mixed solvent, and thus a release sheet could not be produced.

  Table 1 shows the type and amount of each component of the release agent composition in each Example and each Comparative Example.

  In Table 1, polybutadiene was indicated as “PB”, poly (4-methyl-1-pentene) resin as “PMP”, and melt flow rate as “MFR”.

2. Preparation of pressure-sensitive adhesive sheet A pressure-sensitive adhesive solution was applied on the release sheet using an applicator on the release agent layer of the release sheet obtained in each example and each comparative example.

  In addition, as an adhesive solution, 100 mass parts (solid content density | concentration containing a carboxy group containing acrylic copolymer containing a brand name "AS665", the product name "AS665" by a company oil and fat industry Co., Ltd.) 100 mass parts (solid The amount obtained by adding 1.0 part by mass (in terms of solid content) of an isocyanate-based crosslinking agent (trade name “Coronate L”, solid content concentration: 75% by mass, manufactured by Nippon Polyurethane Co., Ltd.) was used.

  Next, the formed coating film was dried by heating at 100 ° C. for 1 minute to form an adhesive layer having a thickness of 25 μm. A polyethylene terephthalate film (trade name: Diafoil T-100, manufactured by Mitsubishi Plastics Co., Ltd., thickness: 50 μm) was bonded to this to obtain an adhesive sheet.

3. Evaluation [XPS measurement]
PHI Quantera SXM (manufactured by ULVAC-PHI) was used for XPS measurement on the surface of the release agent layer of the release sheet of each Example and each Comparative Example. Measurement was performed using a monochromated Al Kα as an X-ray source at a photoelectron extraction angle of 45 °, and the element ratio of carbon, silicon and oxygen existing on the surface was calculated.

[Surface free energy measurement]
Using a contact angle meter (DM-701, manufactured by Kyowa Interface Science Co., Ltd.), the contact angle of the surface of the release agent layer of the release sheet of each Example and each Comparative Example to three liquids of water, diiodomethane and dibromonaphthalene was 23. It measured in the environment of 50 degreeCRH, and calculated the surface free energy by the Kitazaki field method.

[Peeling force test]
Each pressure-sensitive adhesive sheet provided with the release sheet of each Example and each Comparative Example was aged in an environment of 23 ° C. and 50% RH for 1 week.

  Thereafter, the peel strength of the pressure-sensitive adhesive sheet after being left for 1 day in an environment of 23 ° C. and 50% RH and the pressure-sensitive adhesive sheet after being left for 1 day in an environment of 70 ° C. were measured.

  The peel force was measured by cutting the pressure-sensitive adhesive body into a width of 20 mm and a length of 200 mm in an environment of 23 ° C. and 50% RH, fixing the release sheet using a tensile tester, and peeling the pressure-sensitive adhesive sheet to a peeling speed of 0.3 m. The peel force was measured by pulling in the 180 ° direction at / min.

Further, the peel force of the pressure-sensitive adhesive sheet after being left for 1 day in an environment of 70 ° C. was divided by the peel force of the pressure-sensitive adhesive sheet after being left for 1 day in an environment of 23 ° C. and 50% RH to obtain a change rate of the peel force. .
These results are shown in Table 2.

  As is clear from Table 2, the release sheet of the present invention suppressed the increase in peel force even when stored under high temperature conditions. On the other hand, the release sheet of Comparative Example 1 did not give satisfactory results. Moreover, since the release sheet (adhesive sheet) of the present invention does not contain a silicone compound, it was difficult to adversely affect electrical components such as relays.

100, 110, 120 Adhesive sheet 1, 1 ', 10 Release sheet 11, 11' Release agent layer 12, 12 'Base material 13 Primer layer 2, 2', 2 "Adhesive sheet body 21, 21A, 21B Adhesive layer 22 , 22 'Adhesive sheet base material

Claims (12)

A release sheet having a substrate and a release agent layer,
The release agent layer is formed of a release agent composition containing a diene polymer (A) and a poly (4-methyl-1-pentene) resin (B),
The content of the poly (4-methyl-1-pentene) resin (B) in the release agent composition is 0.01 parts by mass or more and 15 parts by mass with respect to 100 parts by mass of the diene polymer (A). 0.0 parts by mass or less,
The release sheet, wherein the poly (4-methyl-1-pentene) resin (B) has a melting point of 199 ° C. or lower. The release sheet according to claim 1, wherein the surface free energy of the release agent layer measured by a contact angle method is 32 mJ / m ² or less.   The release sheet according to claim 1 or 2, wherein a ratio of C element on the surface of the release agent layer in XPS surface element analysis is 90 atomic% or more.   The release sheet according to any one of claims 1 to 3, wherein a ratio of Si element on the surface of the release agent layer in XPS surface elemental analysis is 0.5 atomic% or less.   The release sheet according to any one of claims 1 to 4, wherein an average thickness of the release agent layer is 0.01 µm or more and 1.0 µm or less.   The melt flow rate of the poly (4-methyl-1-pentene) resin (B) measured under the conditions of a heating temperature of 230 ° C. and a load of 2.16 kgf in accordance with ASTM D1238 is 0.1 g / 10 min. The release sheet according to any one of claims 1 to 5, which is 100.0 g / 10 min or less.   The release sheet according to any one of claims 1 to 6, further comprising a primer layer between the substrate and the release agent layer. An adhesive sheet substrate;
An adhesive layer laminated on one side of the adhesive sheet substrate;
A release sheet laminated on the adhesive surface of the adhesive layer,
The pressure-sensitive adhesive sheet, wherein the release sheet is the release sheet according to any one of claims 1 to 7. An adhesive sheet substrate;
Two adhesive layers laminated on both sides of the adhesive sheet substrate;
Two release sheets laminated on the adhesive surfaces of the two adhesive layers,
The pressure-sensitive adhesive sheet, wherein at least one of the two release sheets is the release sheet according to any one of claims 1 to 7. An adhesive layer;
Two release sheets laminated on both sides of the pressure-sensitive adhesive layer,
The pressure-sensitive adhesive sheet, wherein at least one of the two release sheets is the release sheet according to any one of claims 1 to 7.   The pressure-sensitive adhesive sheet according to any one of claims 8 to 10, wherein the pressure-sensitive adhesive layer is composed of an acrylic pressure-sensitive adhesive.   The pressure-sensitive adhesive sheet according to claim 11, wherein the acrylic pressure-sensitive adhesive has a carboxy group.

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