JP6511317B2 - Release sheet and adhesive sheet - Google Patents

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.

  A pressure-sensitive adhesive sheet is attached to such an electric component for the purpose of temporarily fixing at the time of assembly or displaying the content of the component.

  Such a pressure-sensitive adhesive sheet is usually composed of a pressure-sensitive adhesive sheet substrate and a pressure-sensitive adhesive layer, and is attached to a release sheet before being attached to an electrical component.

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

  However, when such a release sheet is attached to a pressure-sensitive adhesive sheet, it is known that silicone compounds such as low molecular weight silicone resin, siloxane and silicone oil in the release sheet transfer to the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet. The release sheet is wound into a roll after production, but at this time, the back surface of the release sheet comes in contact with the release agent layer, and the silicone compound in the silicone resin is transferred to the back surface of the release sheet. It is also known that the silicone compound transferred to the back surface of the release sheet transfers again to the surface of the pressure-sensitive adhesive sheet when the pressure-sensitive adhesive body is wound up in a roll at the time of producing the pressure-sensitive adhesive body. For this reason, when the pressure-sensitive adhesive sheet attached to such a release sheet is attached to the electric component, thereafter, the silicone compound transferred to the surface of the pressure-sensitive adhesive layer or the adhesive sheet is gradually vaporized. The vaporized silicone compound is deposited, for example, on the surface of the electrical contact portion by an arc or the like generated in the vicinity of the electrical contact portion of the electrical component to form a minute silicone compound layer or a silicon oxide compound layer derived from the silicone compound. It is known to do.

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

  In particular, when sticking to a hard disk drive, the silicone compound transferred to the surface of the pressure-sensitive adhesive layer or pressure-sensitive adhesive sheet gradually evaporates, and the silicon compound derived from the silicone compound or silicone compound becomes the magnetic head or disk surface Deposits of the minute 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 non-silicone release agents not containing a silicone compound has been attempted (see, for example, Patent Document 2). However, release sheets composed of conventional non-silicone release agents tend to be heavy release.

  In order to improve such heavy peeling, a release sheet using a polybutadiene compound has been developed (see, for example, Patent Document 3).

  However, in the release sheet of Patent Document 3, there is a problem that when it is stored under high temperature conditions to confirm durability, storage stability, and the like after bonding to the pressure-sensitive adhesive layer, heavy peeling may occur.

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

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

Such an object is achieved by the present invention of the following (1) to (12).
(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 diene polymer (A) contains 90 mol% or more of cis 1,4-butadiene as a monomer,
The content of the poly (4-methyl-1-pentene) -based resin (B) in the release agent composition is 0.01 parts by mass or more to 15 parts by mass with respect to 100 parts by mass of the diene-based polymer (A). .0 parts by mass or less,
The melting point of the poly (4-methyl-1-pentene) based resin (B) is 199 ° C. or less.

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

  (3) The release sheet according to (1) or (2) above, wherein the ratio of the 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 the above (1) to (3), wherein the 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 the above (1) to (4), wherein the 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. The release sheet according to any one of the above (1) to (5), which is 1 g / 10 min to 100.0 g / 10 min.

  (7) The release sheet according to any one of the above (1) to (6), which has a primer layer between the substrate and the release agent layer.

(8) Adhesive sheet substrate,
A pressure-sensitive adhesive layer laminated on one side of the pressure-sensitive adhesive sheet substrate;
And a release sheet laminated on the pressure-sensitive adhesive surface of the pressure-sensitive adhesive layer,
A pressure-sensitive adhesive sheet, characterized in that the release sheet is the release sheet according to any one of the above (1) to (7).

(9) Adhesive sheet substrate,
Two pressure-sensitive adhesive layers laminated on both sides of the pressure-sensitive adhesive sheet substrate;
And two release sheets laminated on the adhesive surface of the two adhesive layers,
A pressure-sensitive adhesive sheet characterized in that at least one of the two release sheets is the release sheet according to any one of the above (1) to (7).

(10) With an adhesive layer,
And two release sheets laminated on both sides of the pressure-sensitive adhesive layer,
A pressure-sensitive adhesive sheet characterized in that at least one of the two release sheets is the release sheet according to any one of the above (1) to (7).

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

  ADVANTAGE OF THE INVENTION According to this invention, even when it preserve | saves on high temperature conditions in order to confirm durability, storage stability, etc., it provides the peeling sheet and adhesive sheet which can suppress the raise of peeling force. Can.

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 drawings is referred to as "upper" or "upper", and the lower side is referred to as "lower" or "lower".

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

The base 12 has a function of supporting the release agent layer 11.
The substrate 12 is, for example, a polyester film such as a polyethylene terephthalate film, a polybutylene terephthalate film, a polyethylene naphthalate, a polyolefin film such as polyethylene, a polypropylene film or a polymethylpentene film, a plastic film such as a polycarbonate film, aluminum, stainless steel, etc. It is composed of paper such as metal foil, glassine paper, high-quality paper, coated paper, impregnated paper, synthetic paper, etc., paper in which a thermoplastic resin such as polyethylene is laminated on these paper substrates, and the like.

  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. 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 for forming a release agent layer comprises a diene polymer (A) and a poly (4-methyl-1-pentene) resin (B). It is.

  Further, 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. relative to 100 parts by mass of the diene based polymer. More than 01 parts by mass and less than 15.0 parts by mass.

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

  By having the characteristics as described above, an increase in peel strength 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 of 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 interaction which arises at the interface of an adhesive layer and a release agent layer can be reduced by the fall of this surface free energy, and peeling force raise under high temperature conditions can be suppressed.

Each component will be described in detail below.
[Diene-based polymer (A)]
The release agent composition forming 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 (especially 1,4-polybutadiene rubber). Thereby, the peeling performance of the peeling sheet 1 can be made higher. In addition, it is possible to provide the release sheet 1 that is less likely to adversely affect electrical components such as relays, various switches, connectors, and motors.

  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.

  The mass average molecular weight of the diene polymer before curing is preferably 100,000 or more, and more preferably 300,000 or more. The mass average molecular weight of the diene polymer before curing is preferably 600,000 or less, 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 forming the release agent layer 11 contains a poly (4-methyl-1-pentene) based resin (B).

  The poly (4-methyl-1-pentene) based resin (B) used in the present invention is a resin having a poly (4-methyl-1-pentene) skeleton, and its melting point is 199 ° C. or less. By adding a predetermined amount of such poly (4-methyl-1-pentene) resin (B) to the diene polymer (A), poly (4-methyl-1-pentene) resin (B) Can be appropriately localized 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 of 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 release force under high temperature conditions can be suppressed.

  The melting point of the poly (4-methyl-1-pentene) based resin (B) used in the present invention is 199 ° C. or less, and more preferably 190 ° C. or less. When the melting point of the poly (4-methyl-1-pentene) resin (B) exceeds the above upper limit value, the solubility in components constituting the release agent composition such as the diene polymer (A) and the solvent decreases. As a result, 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 applying a release agent composition can be improved.

  In addition, 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 / hour. It is preferably 10 min or more, more preferably 1.0 g / 10 min or more, and still more preferably 2.0 g / 10 min or more. Further, 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, and 10 More preferably, it is not more than 0 g / 10 min.

  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). The content 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), It 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 value, it is not possible to suppress an increase in peel force under high temperature conditions. On the other hand, when the content of the poly (4-methyl-1-pentene) -based resin (B) exceeds the above upper limit value, the peeling force of the release agent layer 11 at the normal time is increased, and the application to the substrate sheet is performed. When dried, there is a problem that the resin precipitates and whitens.

[Other ingredients]
In addition, the release agent composition which forms the release agent layer 11 is various resin components other than the above, and various additives, such as an antioxidant, a plasticizer, a stabilizer, a crosslinking agent, a sensitizer, a radical initiator, etc. May be included.

  In addition, it does not specifically limit as a curing method of the above-mentioned release agent composition, For example, methods, such as irradiation of active energy rays, such as an ultraviolet-ray and an electron beam, heating, etc. 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 still more 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 still more preferably 0.5 μm or less. When peeling off an adhesive sheet from a peeling sheet as the average thickness of the peeling agent layer 11 is less than the said lower limit, sufficient peeling performance may not be obtained. On the other hand, when the average thickness of the release agent layer 11 exceeds the above upper limit, the release agent layer 11 when the release sheet is wound in a roll is likely to be blocked with the back surface of the release sheet, and the release agent layer 11 is peeled off. Performance may be degraded 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 preferred. Thereby, the wettability of the 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 preferred. Thereby, repelling of the pressure-sensitive adhesive solution can be suppressed when the pressure-sensitive adhesive solution is applied.

  In the present specification, a contact angle meter (DM-701 manufactured by Kyowa Interface Science Co., Ltd.) was used for contact angle measurement by the contact angle method. Then, the contact angles to water, diiodomethane and dibromonaphthalene were measured (23 ° C., 50% RH), and the surface free energy was calculated by the Kitazaki-Hata method.

  Further, the ratio of the C element on the surface of the release agent layer 11 in XPS surface elemental analysis is preferably 90 atomic% or more, more preferably 95 atomic% or more, and still more preferably 98 atomic% or more . Thereby, the interaction generated at the interface between the pressure-sensitive adhesive layer and the release agent layer 11 can be more effectively reduced, and the increase in the peeling force under high temperature conditions can be more effectively suppressed.

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

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

Second Embodiment of Release Sheet
Next, a second embodiment of the release sheet of the present invention will be 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 drawings is referred to as “upper” or “upper”, and the lower side is referred to as “lower” or “lower”.

  In addition, in the following description, it demonstrates centering on difference with embodiment mentioned above regarding the peeling sheet | seat of 2nd Embodiment, and the description is abbreviate | omitted regarding the same matter. Further, in FIG. 2, the same components as those in the first embodiment described above are denoted by the same reference numerals.

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

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

  Examples of the material constituting the primer layer 13 include polyurethane resins such as polyurethane elastomer and modified polyurethane elastomer, acrylic resins such as (meth) acrylate, polyolefin resins such as ethylene vinyl acetate copolymer, 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, from the viewpoint of having solvent resistance to the organic solvent used in the release agent composition and excellent rubber elasticity, it is particularly preferable to use a polyurethane resin.

  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. The average thickness of the primer layer 13 is preferably 3 μm or less, more preferably 1 μm or less. The adhesion 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 above lower limit value or more. Moreover, the blocking at the time of winding up the base material with a primer layer can be suppressed by making the average thickness of the primer layer 13 below the said upper limit.

First Embodiment of Adhesive Sheet
Hereinafter, a first embodiment of the pressure-sensitive adhesive sheet will be 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 substrate 22 and a pressure-sensitive adhesive sheet main body 2 formed of a pressure-sensitive adhesive layer 21 laminated on one side of the pressure-sensitive adhesive sheet substrate 22. It is a single-sided pressure-sensitive adhesive sheet having the release sheet 1 laminated on the pressure-sensitive adhesive surface.

  The pressure-sensitive adhesive sheet substrate 22 has a function of supporting the pressure-sensitive adhesive layer 21 and is, for example, a plastic film such as a polyethylene terephthalate film, a polybutylene terephthalate film, a polyethylene film, a polypropylene film, a polymethylpentene film, a polycarbonate film, It is made of a single substance or a composite of paper 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 adhesive sheet substrate 22 is made 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 with little dust (for example, Japanese Patent Publication No. 6-11959). It is preferable that Since the adhesive sheet substrate 22 is made of a plastic film or dust-free paper, dust and the like are less likely to be generated during processing, use and the like, and it is less likely to adversely affect electronic devices such as relays. In addition, when the pressure-sensitive adhesive sheet substrate 22 is made of a plastic film or dust-free paper, cutting or punching, etc. 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. Polyethylene terephthalate film has the advantages of less dust generation and less gas generation during heating.

  Moreover, in the case of the single-sided pressure-sensitive adhesive sheet, among the above-mentioned, as the pressure-sensitive adhesive sheet substrate 22, it is preferable to use one having printability and printability on the surface.

  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 a surface treatment for the purpose of improving 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. The average thickness of the pressure-sensitive adhesive sheet substrate 22 is preferably 300 μm or less, more preferably 200 μm 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 adhesives, polyester-based pressure-sensitive adhesives, and urethane-based pressure-sensitive adhesives.

  For example, when the pressure-sensitive adhesive is an acrylic pressure-sensitive adhesive, it is mainly composed of a main monomer component that gives tackiness, a comonomer component that gives adhesiveness and cohesion, and a functional group-containing monomer component for improving crosslinking point and adhesiveness. It can be composed of a coalesced or copolymer.

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

  As the main monomer component, for example, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, pentyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, And (meth) acrylic acid alkyl esters such as octyl (meth) acrylate and the like.

  As a comonomer component, for example, methyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, tridecyl (meth) acrylate, benzyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, cyclohexyl (meth) 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 and 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 which has a tendency of heavy peeling is used, the effect of the peeling sheet 1 (peeling 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, and more preferably 0.5% by mass, relative to the total constituent units (100% by mass) of the acrylic polymer constituting the acrylic pressure-sensitive adhesive. % Or more, more preferably 1% by mass or more, still more preferably 2% by mass or more. Further, the content of the functional group-containing monomer component is preferably 50% by mass or less, more preferably 40% by mass or less, based on the total structural units (100% by mass) of the acrylic polymer constituting the acrylic pressure-sensitive adhesive. More preferably, it is 30% by mass or less, still more preferably 20% by mass or less.

  By including these components, the adhesion and cohesion of the pressure-sensitive adhesive composition are improved. Moreover, since such an acrylic adhesive does not generally have an unsaturated bond in a molecule | numerator, the improvement with respect to light or oxygen can be aimed at. Furthermore, the adhesive composition provided with the quality and the characteristic according to a use can be obtained by selecting the kind and molecular weight of a monomer suitably.

  Although such a pressure-sensitive adhesive composition may be any of a crosslinked type that is subjected to a crosslinking treatment and a non-crosslinked type that is not subjected to a crosslinking treatment, a crosslinked type is more preferable. In the case of using a crosslinkable type, the pressure-sensitive adhesive layer 21 having more excellent cohesion can be formed.

  As a crosslinking agent used for a crosslinking-type adhesive composition, an epoxy-type compound, an isocyanate compound, a metal chelate compound, a metal alkoxide, a metal salt, an amine compound, a hydrazine compound, an aldehyde compound etc. are mentioned.

  Moreover, in the pressure-sensitive adhesive composition used in the present invention, various additives such as a plasticizer, a tackifier, and a stabilizer may be contained, as necessary.

  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. The average thickness of the pressure-sensitive adhesive layer 21 is preferably 200 μm or less, more preferably 100 μm or less.

Second Embodiment of Adhesive Sheet
Next, a second embodiment of the pressure-sensitive adhesive sheet of the present invention will be 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 drawings is referred to as “upper” or “upper”, and the lower side is referred to as “lower” or “lower”.

  In the following description, regarding the pressure-sensitive adhesive sheet of the second embodiment, differences from the above-described embodiment will be mainly described, and the description of the same matters will be omitted. Further, in FIG. 4, the same components as those in the above-described embodiment are denoted by the same reference numerals.

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

  The pressure-sensitive adhesive sheet main body 2 'includes a pressure-sensitive adhesive sheet base 22', and a pressure-sensitive adhesive layer 21A and a pressure-sensitive adhesive layer 21B laminated on both sides of the pressure-sensitive adhesive sheet base 22 '.

  The pressure-sensitive adhesive sheet substrate 22 'has a function of supporting the pressure-sensitive adhesive layers 21A and 21B, and can be made of the same material as the pressure-sensitive adhesive sheet substrate 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. Moreover, it is preferable that it is 300 micrometers or less, and, as for the average thickness of adhesive sheet base 22 ', it is more preferable that it is 200 micrometers or less.

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

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

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

  The release sheets 1 and 1 ′ have release agent layers 11 and 11 ′ and substrates 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 above-described release agent composition, or the release agent composition different from the above-described release agent composition may be cured. 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 above-described release agent composition, the release force of the release sheet 1 from the pressure-sensitive adhesive layer 21A is the same as that of the release sheet 1 ′. It is preferable to be different from the peeling force from the adhesive layer 21B. Thereby, when peeling off peeling sheet 1 ', it can prevent that peeling sheet 1 peels off from pressure-sensitive adhesive layer 21A unintentionally.

  In addition, even when the release agent compositions constituting the release agent layer 11 and the release agent layer 11 ′ are the same or different, the release force of the release sheet 1 and the release sheet 1 ′ to the pressure-sensitive adhesive layer The difference is preferably 50 mN / 20 mm or more, more preferably 80 mN / 20 mm or more, and still more preferably 100 mN / 20 mm or more. The difference in the peeling force is more preferably 700 mN / 20 mm or less, and particularly preferably 450 mN / 20 mm or less. In this way, when the release sheet with the smaller release force is removed, it is possible to more effectively prevent the other release sheet from being inadvertently removed from the pressure-sensitive adhesive layer.

  Further, the peeling force of each of the release sheet 1 and the release sheet 1 'to each pressure-sensitive adhesive layer is preferably 1000 mN / 20 mm or less, more preferably 800 mN / 20 mm or less, and further preferably 600 mN / 20 mm or less preferable. The peel strength is more preferably 10 mN / 20 mm or more, and particularly preferably 30 mN / 20 mm or more. This makes it possible to peel the release sheet more easily.

  In addition, the measurement of peeling force specifically cut | judges a double-sided adhesive sheet in width 20 mm and length 200 mm in the environment of 23 degreeC 50% RH, and using a tension tester, one side is a double-sided tape Etc., and the release sheet is pulled at a speed of 0.3 m / min in the direction of 180 °.

<Third Embodiment of Adhesive Sheet>
Next, a third embodiment of the pressure-sensitive adhesive sheet of the present invention will be 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 drawings is referred to as “upper” or “upper”, and the lower side is referred to as “lower” or “lower”.

  In the following description, regarding the pressure-sensitive adhesive sheet of the third embodiment, differences from the above-described embodiment will be mainly described, and the description of the same matters will be omitted. Further, in FIG. 5, the same components as those in the above-described embodiment are denoted by the same reference numerals.

  The pressure-sensitive adhesive sheet 120 according to the present 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. In this respect, the present embodiment is different from the embodiment described above.

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

<Method of Manufacturing Adhesive Sheet 100>
Next, an example of a method of manufacturing the pressure-sensitive adhesive sheet 100 according to the first embodiment will be described.

  The release sheet 1 can be prepared by preparing the base material 12 and applying the above-mentioned release agent composition onto the base material 12 and curing it to form the release agent layer 11.

  The curing method of the release agent composition is not particularly limited. For example, methods such as irradiation of 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 substrate 12 include existing methods such as gravure coating, bar coating, spray coating, spin coating, knife coating, roll coating, and die coating. It 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. It can be used.

  As a form of the adhesive composition in this case, a solvent type, an emulsion type, a hot-melt type etc. are mentioned.

  Thereafter, the pressure-sensitive adhesive sheet base 22 is bonded to the formed pressure-sensitive adhesive layer 21 to obtain the pressure-sensitive adhesive sheet 100.

<Method of Manufacturing Adhesive Sheet 110>
Next, an example of the manufacturing method of the adhesive sheet 110 which concerns on 2nd Embodiment is demonstrated.

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

  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 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 21A is not laminated, and the pressure-sensitive adhesive layer 21B formed on the release sheet 1'.

<Method of Manufacturing Adhesive Sheet 120>
Next, an example of the manufacturing method of the adhesive sheet 120 which concerns on 3rd Embodiment is demonstrated.

  First, release sheet 1 and release sheet 1 ′ are produced in the same manner as the method for producing 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 main body 2 ′ ′.

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

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

  In the embodiment described above, the release sheet is described as being composed of the release agent layer and the base material, but the release agent layer also has a function as the base material like a resin film, It is also good.

Moreover, the manufacturing method of the adhesive sheet of this invention is not limited to the manufacturing method mentioned above.
Moreover, the use of the peeling sheet and the adhesive sheet of this invention is not limited to electrical parts, such as a relay which was mentioned above, various switches, a connector, a motor, a hard disk.

Next, specific examples of the present invention will be described.
1. Preparation of Release Sheet (Example 1)
(Preparation of primer layer)
On a polyethylene terephthalate film (Mitsubishi resin Co., Ltd., trade name: Diafoil T-100, thickness: 50 μm), polyester polyol (made by DIC Corp., trade name: Klissona 5150 S, solid content 50% by mass) 100 mass The film thickness becomes about 0.1 μm after drying a solution obtained by diluting 1 part and 5 parts by mass of an isocyanate compound (made by DIC Corporation, trade name: Klisbon NX) to a solid content concentration of 1% by mass with methyl ethyl ketone solvent 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 methylcyclohexane / methyl isobutyl ketone = 80/20 mixed solvent in 100 parts by mass of polybutadiene (manufactured by Ube Industries, Ltd., trade name: UBEPOL-BR150, mass average molecular weight: 540,000) -Penten) Solid content of resin (Mitsui Chemical Co., Ltd., Melting point: 180 ° C, Melt flow rate measured under conditions of heating temperature 230 ° C, load 2.16 kgf according to ASTM D 1238: 4 g / 10 min) Add 1.0 part by weight of a 10% solution (0.10 parts by weight as solid content) and 1 part by weight of a hindered phenol-based antioxidant (Ciba Specialty Chemicals, trade name: Irganox HP 2251), The release agent composition diluted to a solid content concentration of 1.5% by mass with a toluene solvent was obtained.

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

Next, UV light is applied to the coating layer at a conveyor speed of 40 m / min (ultraviolet irradiation condition: 100 mJ / cm ² ) by means of a belt conveyor type ultraviolet irradiation device with one fusion H bulb 240 w / cm which is an electrodeless lamp. It was irradiated and cured 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 infrared absorption spectroscopy (ATR method).

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

  In addition, in the comparative example 2, since poly (4-methyl- 1-pentene) type | system | group resin deposited at the time of peeling sheet preparation, the peeling sheet was not able to be produced.

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

  Table 1 shows the types, addition amounts and the like of the components of the release agent composition in each of the examples and the comparative examples.

  In Table 1, polybutadiene is shown 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 onto the release sheet using the 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 parts by mass (solid content concentration: 40 mass% solid content concentration containing an acrylic adhesive (trade name “AS665”, a carboxyl group-containing acrylic copolymer, product name: One-company Fat and Oil Industry Co., Ltd.) What added 1.0 mass part (solid content conversion) of isocyanate type crosslinking agent (The Nippon Polyurethane Co., Ltd. make, brand name "Coronato L", solid content concentration 75 mass%) was added to minute conversion.

  Next, the formed coating film was dried by heating at 100 ° C. for 1 minute to form a 25 μm-thick pressure-sensitive adhesive layer. A polyethylene terephthalate film (manufactured by Mitsubishi Resins Co., Ltd., trade name: Diafoil T-100, thickness: 50 μm) was laminated thereon to form a pressure-sensitive adhesive sheet.

3. Evaluation [XPS Measurement]
The XPS measurement of the release agent layer surface of the release sheet of each Example and each comparative example used PHI Quantera SXM (made by ULVAC-PHI company). Measurement was performed at a photoelectron take-off angle of 45 ° using monochromatic Al K α as an X-ray source to calculate an element ratio of carbon, silicon and oxygen present on the surface.

[Surface free energy measurement]
The contact angles of the release agent layer surface of the release sheet of each example and each comparative example to water, diiodomethane and dibromonaphthalene were measured using a contact angle meter (DM-701 manufactured by Kyowa Interface Science Co., Ltd.) 23 The surface free energy was calculated by the Kitazaki-Hata method by measurement under an environment of 50% RH.

[Peel force test]
Each adhesive sheet provided with the release sheet of each example and each comparative example was aged for 1 week in an environment of 23 ° C. and 50% RH.

  Then, the peeling force was measured about the adhesive sheet after 1-day leaving-to-stand in 23 degreeC 50% RH environment, and the adhesive sheet after leaving-to-date 1 day in 70 degreeC environment.

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

The rate of change in peel strength was determined by dividing the peel strength of the pressure-sensitive adhesive sheet after standing for 1 day in an environment of 70 ° C. by the peel strength of the pressure-sensitive adhesive sheet after standing for 1 day in an environment of 23 ° C. and 50% RH. .
These results are shown in Table 2.

  As apparent from Table 2, in the release sheet of the present invention, an increase in the peel strength was suppressed even when stored under high temperature conditions. On the other hand, the release sheet of Comparative Example 1 did not give a satisfactory result. Moreover, since the release sheet (adhesive sheet) of this invention did not contain a silicone compound, it was a thing which is hard to give a bad influence to electrical components, such as a relay.

DESCRIPTION OF SYMBOLS 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 main body 21, 21A, 21B Adhesive layer 22 , 22 'adhesive sheet substrate

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 diene polymer (A) contains 90 mol% or more of cis 1,4-butadiene as a monomer,
The content of the poly (4-methyl-1-pentene) -based resin (B) in the release agent composition is 0.01 parts by mass or more to 15 parts by mass with respect to 100 parts by mass of the diene-based polymer (A). .0 parts by mass or less,
The melting point of the poly (4-methyl-1-pentene) based resin (B) is 199 ° C. or less. The release sheet according to claim 1, wherein the surface free energy of the release agent layer measured by the contact angle method is 32 mJ / m ² or less.   The release sheet according to claim 1, wherein a ratio of the C element on the surface of the release agent layer in XPS surface elemental 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 the 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 according to 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. Adhesive sheet substrate,
A pressure-sensitive adhesive layer laminated on one side of the pressure-sensitive adhesive sheet substrate;
And a release sheet laminated on the pressure-sensitive adhesive surface of the pressure-sensitive adhesive layer,
The pressure-sensitive adhesive sheet, wherein the release sheet is the release sheet according to any one of claims 1 to 7. Adhesive sheet substrate,
Two pressure-sensitive adhesive layers laminated on both sides of the pressure-sensitive adhesive sheet substrate;
And two release sheets laminated on the adhesive surface of the two adhesive layers,
An adhesive sheet characterized in that at least one of the two release sheets is the release sheet according to any one of claims 1 to 7. An adhesive layer,
And two release sheets laminated on both sides of the pressure-sensitive adhesive layer,
An adhesive sheet characterized in that 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 made 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.

Images