JP5508779B2 - Release sheet and manufacturing method thereof - Google Patents

Description

  The present invention relates to a release sheet and a method for producing the same. More specifically, the present invention relates to a release sheet and a method for producing the same that are suitably used in applications in which silicon compounds that have migrated to the pressure-sensitive adhesive surface are problematic, such as adhesion of electronic parts and labeling, and pressure-sensitive adhesive sheets for processing semiconductor wafers. Is.

  In recent years, pressure-sensitive adhesive sheets have been used in various stages and types of manufacturing processes for precision electronic devices such as ceramic capacitors, hard disk drives, and semiconductor devices. In pressure-sensitive adhesive sheets used in the manufacturing process of such precision electronic devices, silicone-based pressure-sensitive adhesives may cause troubles in electronic parts due to the low molecular weight silicon compound contained therein. For example, an acrylic adhesive, a polyester adhesive, a urethane adhesive, or the like is used. In order to protect the pressure-sensitive adhesive layer until use, this non-silicone-based pressure-sensitive adhesive sheet is laminated with a release sheet provided with a release agent layer on a substrate.

Currently, silicone release agents are mainly used for this release sheet, but it is said that when a pressure sensitive adhesive sheet is bonded to a silicone release agent, transfer of the silicon compound to the pressure sensitive adhesive surface occurs. When a simple adhesive sheet is used as a label for, for example, a hard disk (HDD), it is said that there is a problem that a minute silicon compound transferred to the adhesive surface causes a malfunction in the disk. For this reason, examination which reduces transfer of the silicon compound from a peeling sheet is performed. Further, alkyd resins known as non-silicone release agents (see, for example, Patent Document 1), long-chain alkyl resins (see, for example, Patent Document 2) and polyolefin resins (see, for example, Patent Document 3) Attempts have been made to use for the release agent layer.
However, when these resins are used in the release agent layer, there is a problem that the release force from the adhesive layer is high and the adhesive layer and the release agent layer may not be released. In the field of electronic materials, it is often required to form a release agent layer at a low temperature and to be resistant to an organic solvent because of the relationship with the base material.

Japanese Unexamined Patent Publication No. 57-49585 JP 2002-249757 A JP 2002-59515 A

  Under such circumstances, the present invention is non-silicone, has good peelability from the pressure-sensitive adhesive layer, can form the release agent layer at a low temperature, and does not drop off the release agent layer. An object of the present invention is to provide a release sheet having solvent resistance.

As a result of intensive studies to achieve the above object, the present inventors have determined that an olefin-based uncrosslinked rubber containing a monomer that induces an unsaturated bond in a molecule at a predetermined ratio is an electron-withdrawing group-containing polyfunctional monomer. The uncrosslinked rubber can be efficiently cross-linked by irradiating with active energy rays in the presence of, and the release sheet using the thus cured product as a release agent layer has a good release force. And having excellent adhesion between the release agent layer and the substrate. The present invention has been completed based on such findings.
That is, the present invention
(1) A release sheet used to protect an adhesive layer of an adhesive sheet, which has a base sheet and a release agent layer, and the release agent layer is (A) an unsaturated bond in the molecule. Irradiation of active energy rays to an uncrosslinked rubber material layer containing an olefin-based uncrosslinked rubber obtained by polymerizing 0.005 to 1.5 mol% of a monomer for deriving water and (B) an electron withdrawing group-containing polyfunctional monomer A release sheet characterized by being a cured layer formed by
(2) The release sheet according to (1), wherein the active energy ray is ultraviolet light, and the uncrosslinked rubber material layer further contains a photopolymerization initiator,
(3) The uncrosslinked rubber material layer contains the photopolymerization initiator in a proportion of 0.01 to 20 parts by mass with respect to 100 parts by mass of the olefin-based uncrosslinked rubber as the component (A). Release sheet,
(4) The non-crosslinked rubber material layer includes any of (1) to (3) above, wherein the component (B) is contained in an amount of 0.1 to 30 parts by mass with respect to 100 parts by mass of the component (A). The release sheet as described,
(5) The release sheet according to any one of (1) to (4) above, wherein the release agent layer has a thickness of 0.02 to 5.0 μm.
(6) On the base sheet, (A) an olefin-based uncrosslinked rubber obtained by polymerizing 0.005 to 1.5 mol% of a monomer that induces an unsaturated bond in the molecule, and (B) containing an electron withdrawing group Applying a drying agent layer-forming coating solution containing a polyfunctional monomer, drying to provide an uncrosslinked rubber material layer, and then irradiating with active energy rays to cure, and a method for producing a release sheet, and (7) The method for producing a release sheet according to (6) above, wherein the active energy ray is ultraviolet light, and the release agent layer forming coating solution further contains a photopolymerization initiator,
Is to provide.

  The release sheet of the present invention does not migrate the silicon compound to the pressure-sensitive adhesive layer surface and has excellent peelability. Moreover, in the manufacturing method of the peeling sheet of this invention, since it is possible to form a releasing agent layer at low temperature, it is possible to form a releasing agent layer on a substrate having poor heat resistance. Furthermore, the release sheet of the present invention has characteristics such as excellent resistance to organic solvents such as toluene, ethyl acetate, and methyl ethyl ketone (MEK), and can also cope with transfer coating of an adhesive. Therefore, the release sheet of the present invention can be suitably used in applications where adhesion of electronic parts and labels, and silicon compounds that have migrated to the surface of the pressure-sensitive adhesive layer are problematic, such as pressure-sensitive adhesive sheets for processing semiconductor wafers.

First, the release sheet of the present invention will be described.
The release sheet of the present invention has a base sheet and a release agent layer, and the release agent layer (A) contains 0.005 to 1.5 mol% of a monomer that induces an unsaturated bond in the molecule. It is a cured layer formed by irradiating an active energy ray to an uncrosslinked rubber material layer containing a polymerized olefinic uncrosslinked rubber and (B) an electron-withdrawing group-containing polyfunctional monomer. .

[Base material sheet]
Although there is no restriction | limiting in particular as a base material sheet used for the peeling sheet of this invention, According to the intended purpose of the said peeling sheet, it selects suitably. For example, various types of paper such as fine paper, art paper, coated paper, glassine paper, laminated paper obtained by laminating a thermoplastic resin such as polyethylene on these paper base materials, various synthetic papers, aluminum foil, copper foil and iron foil Porous materials such as metal foil, nonwoven fabric, and the like, and polyolefin resins such as polyethylene resin and polypropylene resin, polyester resins such as polybutylene terephthalate resin and polyethylene terephthalate resin, acetate resin, ABS resin, polystyrene resin, vinyl chloride resin, etc. Examples thereof include a plastic film, a sheet, and a plastic film or sheet made of a mixture or laminate of these resins. The substrate sheet such as a plastic film or sheet may be unstretched, or may be stretched in a uniaxial direction or a biaxial direction such as longitudinal or lateral.

  When a plastic film or sheet is used as the substrate sheet, a surface treatment such as an oxidation method or a concavo-convex method may be applied as desired in order to improve adhesion to the release agent layer provided on the sheet. it can. Examples of the oxidation method include, but are not limited to, corona discharge treatment method, chromic acid oxidation (wet), flame treatment, hot air treatment, ozone / ultraviolet irradiation treatment, and the like. Is not limited, and examples thereof include a sand blasting method and a solvent processing method. These surface treatment methods are appropriately selected depending on the type of the base sheet, but generally, a corona discharge treatment method is preferably used from the viewpoints of effects and operability. Moreover, primer treatment can also be performed.

Further, a sealing layer may be provided as desired between the base sheet and the release agent layer. In addition to preventing the release agent from penetrating into the base sheet, this sealing layer is used for the purpose of further improving the adhesion between the base sheet and the release agent layer, and when the base sheet is too flexible with paper. Is provided for the purpose of imparting rigidity. Such a sealing layer is not particularly limited, for example, a styrene-butadiene copolymer, an acrylic resin, a polyester resin, a polyurethane resin, a polystyrene resin, etc. as a main component, if necessary, clay, Examples thereof include a layer made of a material to which a filler such as silica, calcium carbonate, titanium oxide, or zinc oxide is added. The thickness of the sealing layer is not particularly limited, but is usually about 0.001 to 5.0 μm.
The thickness of the base sheet is not particularly limited, but is usually 10 to 250 μm.

[(A) Uncrosslinked rubber having an unsaturated bond in the molecule]
In the release sheet of the present invention, an olefin obtained by polymerizing 0.005 to 1.5 mol% of a monomer that induces an unsaturated bond in the molecule used as the component (A) of the release agent layer provided on the base sheet. The non-crosslinked rubber is not particularly limited. For example, natural rubber, ethylene-propylene-diene copolymer rubber (EPDM rubber), butyl rubber, styrene-isoprene copolymer rubber, styrene-butadiene copolymer rubber, styrene-butadiene-butylene- Examples thereof include styrene copolymer rubber, styrene-isoprene-styrene copolymer rubber, and styrene-butadiene-styrene copolymer rubber. These uncrosslinked rubbers may be used alone or in combination of two or more.
In the present invention, the olefin-based uncrosslinked rubber is required to be obtained by polymerizing 0.005 to 1.5 mol% of a monomer that induces an unsaturated bond in the polymer chain. Those obtained by polymerization of ˜1.3 mol% are preferred.
Specifically, EPDM rubber, styrene-isoprene copolymer rubber, and styrene-butadiene copolymer rubber obtained by polymerizing 0.005 to 1.5 mol% of a monomer that induces an unsaturated bond in the polymer chain are preferable. EPDM Rubber is more preferred.
In the present invention, even an EPDM rubber having a low crosslinking rate can be effectively crosslinked.
Examples of the monomer that induces an unsaturated bond include isoprene, 1,3-butadiene, ethylidene norbornene, 1,4-hexadiene, and dicyclopentadiene.

[(B) Electron withdrawing group-containing polyfunctional monomer]
Examples of the electron withdrawing group in the polyfunctional monomer include groups such as —NO ₂ , —CN, —COR (R represents an alkyl group; the same applies hereinafter), —CONR ₂ , —CONHR, —COOR and the like. .
The electron withdrawing group is preferably in the vicinity of a carbon-carbon double bond (hereinafter referred to as a functional double bond) of the functional group in the polyfunctional monomer, and in particular, directly on the carbon atom constituting the functional double bond. Bonding is preferred.
Although there is no restriction | limiting in particular in the electron withdrawing group containing polyfunctional monomer used by this invention, From viewpoints, such as availability and reactivity, a (meth) acrylic-acid type polyfunctional monomer is preferable.

Examples of the (meth) acrylic acid-based polyfunctional monomer include tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, ethylene oxide-added bisphenol A di (meth) acrylate, and propylene oxide-added bisphenol A di (meta). ) Acrylate, 1,10-decanediol di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, ethylene oxide-added 2-methyl-1,3-propanediol di (meth) acrylate, neopentyl glycol di (meth) ) Acrylate, 2-hydroxy-3-acryloyloxypropyl methacrylate, propylene oxide / ethylene oxide-added bisphenol A di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonane Di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, ethylene oxide-added isocyanuric acid tri (meth) acrylate, ethylene oxide-added trimethylolpropane tri (meth) ) Acrylate, trimethylolpropane tri (meth) acrylate, propylene oxide-added trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, ethylene oxide-added pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate , Propylene oxide-added pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate , Cyclohexanedimethanol di (meth) acrylate, ethylene oxide addition cyclohexanedimethanol di (meth) acrylate and ethylene oxide addition glycerin tri (meth) acrylate. In addition, (meth) acrylate means both acrylate and methacrylate.
In the present invention, these (meth) acrylic acid polyfunctional monomers may be used alone or in combination of two or more.
The amount of the (B) component electron-withdrawing group-containing polyfunctional monomer is usually about 0.1 to 30 parts by mass with respect to 100 parts by mass of the (A) component olefinic uncrosslinked rubber.
If the amount is less than 0.1 parts by mass, the crosslinking cannot be sufficiently performed. If the amount exceeds 30 parts by mass, components that are not compatible with the uncrosslinked rubber increase, or the number of unreacted polyfunctional monomers increases. Ingredients increase, causing problems with the adhesive sheet.

[Photopolymerization initiator]
In the release sheet of the present invention, the uncrosslinked rubber material layer is crosslinked by irradiation with active energy rays to form a release agent layer. The active energy rays include the viewpoints of equipment, productivity, economy, and the like. Therefore, ultraviolet rays are preferably used.
When ultraviolet rays are used as the active energy rays, a photopolymerization initiator can be used as necessary. In addition, when using an electron beam, it is not necessary to use a photoinitiator.
In the present invention, the photopolymerization initiator that can be used is not particularly limited. For example, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy 2-methyl-1-phenyl-propan-1-one, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy- 1- [4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl] -2-methyl-propan-1-one, 2-methyl-1- (4-methylthiophenyl) -2- Morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2- (dimethylamino) -2-[(4-methylphenyl) methyl] Alkylphenone-based photopolymerization initiators such as -1- [4- (4-morpholinyl) phenyl] -1-butanone, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis (2,4,6-trimethyl) Acylphosphine oxide photopolymerization initiators such as benzoyl) -phenylphosphine oxide, bis (η5-2,4-cyclopentadien-1-yl) -bis [2,6-difluoro-3- (1H-pyrrole-1- Yl) -phenyl] titanium and other titanocene-based photopolymerization initiators, 1,2-octanedione-1- [4- (phenylthio) -2- (O-benzoyloxime)], ethanone-1- [9-ethyl- Oxime ester photopolymerization initiators such as 6- (2-methylbenzoyl) -9H-carbazol-3-yl] -1- (O-acetyloxime), benzophenone, p-chloroben Phenone, benzoylbenzoic acid, methyl o-benzoylbenzoate, 4-methylbenzophenone, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4'-methyl-diphenylsulfide, 3,3'-dimethyl-4 Benzophenone photopolymerization initiators such as -methoxybenzophenone, 2,4,6-trimethylbenzophenone, 4- (13-acryloyl-1,4,7,10,13-pentaoxatridecyl) -benzophenone, thioxanthone, 2- Chlorothioxanthone, 3-methylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diisopropylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, 2-methylthioxanthone, 2-isopropyl Examples thereof include thioxanthone photopolymerization initiators such as thioxanthone and 4-isopropylthioxanthone.

These photoinitiators may be used individually by 1 type, and may be used in combination of 2 or more type. The photopolymerization initiator may be used in combination with a photopolymerization initiation assistant such as triisopropanolamine or 4,4′-diethylaminobenzophenone.
The amount of the photopolymerization initiator used is usually 0.01 to 20 parts by mass, preferably 0.1 to 100 parts by mass (solid content) of the olefin-based uncrosslinked rubber (A) described above as a solid content. It is selected in the range of 5 to 10 parts by mass. When the amount of the photopolymerization initiator used is less than 0.01 parts by mass, sufficient crosslinking cannot be performed. On the other hand, when the amount exceeds 20 parts by mass, the main component of the olefin-based uncrosslinked rubber which is the component (A) at the time of ultraviolet irradiation. The decomposition of the skeleton is promoted.

[Other ingredients]
The release sheet of the present invention preferably contains an antioxidant. There is no restriction | limiting in particular as antioxidant, Well-known phosphite type antioxidant, organic sulfur type antioxidant, hindered phenolic antioxidant, etc. are mentioned.

[Organic solvent]
The release agent layer-forming coating solution is preferably prepared by dissolving the components described above in an organic solvent. The organic solvent used at this time can be appropriately selected from known solvents having good solubility in the olefin-based uncrosslinked rubber of the component (A). Examples of such an organic solvent include toluene, xylene, methanol, ethanol, isobutanol, n-butanol, acetone, methyl ethyl ketone, and tetrahydrofuran. These may be used individually by 1 type and may be used in combination of 2 or more type.
The solid content concentration of the coating solution is preferably about 0.1 to 15% by mass.

Next, the manufacturing method of the peeling sheet of this invention is demonstrated.
[Method for producing release sheet]
In the method for producing a release sheet of the present invention, 0.005 to 1.5 mol% of a monomer that induces an unsaturated bond in the molecule (A) prepared as described above is polymerized on a base sheet. After applying an olefin-based uncrosslinked rubber and (B) a release agent layer-forming coating solution containing an electron-withdrawing group-containing polyfunctional monomer and drying to provide an uncrosslinked rubber material layer, irradiation with active energy rays is performed. The release sheet is manufactured by curing. In addition, as above-mentioned, when using an ultraviolet-ray as an active energy ray, the said peeling agent layer forming coating liquid contains a photoinitiator normally as mentioned above.

Coating of the coating liquid on the base sheet is conventionally known, for example, bar coating method, reverse roll coating method, knife coating method, roll knife coating method, gravure coating method, air doctor coating method, doctor blade coating method, etc. The coating method can be used.
In the present invention, the release agent layer is thus formed by applying the coating liquid onto the substrate sheet, and irradiating active energy rays after drying. Examples of the active energy ray used include an electron beam and ultraviolet rays, and ultraviolet rays are preferable from the viewpoint of the absorption wavelength of the photoinitiator used and damage due to deterioration of the base material.
Conventionally known high-pressure mercury lamps, metal halide lamps, high-power metal halide lamps, electrodeless lamps and the like can be used as ultraviolet lamps used for ultraviolet irradiation, but there are no electrodes in terms of curability of the uncrosslinked rubber of component (A). A lamp is most suitable.
The amount of UV irradiation is preferably in the range of 10 to 300 mJ / cm ² in terms of the amount of light from the viewpoint of obtaining high adhesion between the base sheet and the release agent layer and obtaining light release.

The thickness of the release agent layer thus formed is preferably 0.02 to 5.0 μm in a state where the coating liquid is applied onto the base film, dried and cured, and Preferably it is 0.05-1.5 micrometers. When the thickness is 0.02 μm or more, sufficient peelability is obtained, and when the thickness is 5.0 μm or less, there is no possibility of causing problems such as blocking between the back surface of the release sheet and the release agent layer.
There is no restriction | limiting in particular as an adhesive applied to the peeling sheet of this invention, For example, selecting suitably from conventionally well-known adhesives, such as an acrylic adhesive, a polyester-type adhesive, a urethane type adhesive, for example, for example. Can do.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
<Measurement of peel force>
An adhesive sheet [“31B tape” manufactured by Nitto Denko Co., Ltd.] is bonded to the release agent layer, and the release force after standing for 30 minutes under the conditions of a temperature of 23 ° C. and a relative humidity of 50% is based on JIS Z 0237, A 180 ° peel test was performed under the condition of a peeling speed of 0.3 m / min.

<Evaluation of curability>
The surface of the release sheet on which the release agent layer was provided was rubbed 10 times with a finger and visually checked for cloudiness (smear). In addition, the adhesive tape is applied to the rubbed part, the peel force is measured by measuring the peel force, and the presence or absence of the coating film is removed (rub off) by the change in peel force before and after rubbing. The following evaluation criteria It was evaluated by.
[Smear evaluation criteria]
◯: Smear is not confirmed at all or even if it is slightly confirmed, it is within the practical range.
Δ: Smear is slightly confirmed (practical problems may occur).
X: Smear is remarkably confirmed.
[Evaluation criteria for love-off]
○: No rub-off is confirmed, or even if it is confirmed slightly, it is within the practical range.
Δ: Some rub-off is confirmed (a problem may occur in practice).
X: Love-off is remarkably confirmed.

Example 1
(A) Ethylene-propylene-diene copolymer rubber [manufactured by JSR, product name “JSR EP43”, polymerization ratio of monomer that induces unsaturated bond: 0.01 mol%] as olefin-based uncrosslinked rubber of component (A) 100 3 parts by mass (solid content), 3 parts by mass (solid content) of benzophenone [manufactured by Tokyo Chemical Industry Co., Ltd.] as a photopolymerization initiator, and trimethylolpropane triacrylate [B] as an electron withdrawing group-containing polyfunctional monomer 5 parts by mass of product name “NK Ester A-TMPT” manufactured by Shin-Nakamura Chemical Co., Ltd. was diluted with toluene so that the solid content concentration was about 0.5% by mass. The release agent solution was applied to one side of a polyethylene terephthalate (PET) film [trade name “PET38T-100” manufactured by Mitsubishi Chemical Polyester Film Co., Ltd.] as a base sheet using a Mayer bar, and then at 90 ° C. for about 1 minute. The solvent was dried to provide an uncrosslinked rubber material layer, which was irradiated with ultraviolet rays (about 200 mJ / cm ² ) with an electrodeless lamp and cured to obtain a release sheet having a release agent layer with a thickness of 0.1 μm. Table 1 shows the peel force measurement results and the curability evaluation results.

Examples 2-11 and Comparative Examples 1-10
Except for changing the composition and blending of the uncrosslinked rubber, the electron-withdrawing group-containing polyfunctional monomer and the photopolymerization initiator according to Table 1, a release sheet was prepared in the same manner as in Example 1, and the peel force was measured and cured. Evaluation was performed. The results are shown in Table 1.

[note]
A-1: Ethylene-propylene-diene copolymer rubber [manufactured by JSR, product name “JSR EP43”, polymerization ratio of monomer that induces unsaturated bond: 0.01 mol%]
A-2: Ethylene-propylene-diene copolymer rubber [manufactured by JSR, product name “JSR EP21”, polymerization ratio of monomer that induces unsaturated bond: 0.07 mol%]
A-3: Ethylene-propylene-diene copolymer rubber [manufactured by JSR, product name “JSR EP33”, polymerization ratio of monomer that induces unsaturated bond: 0.04 mol%]
A-4: Styrene-isoprene copolymer [manufactured by Zeon Corporation, product name “Quintac 3520”, polymerization ratio of monomer that induces unsaturated bond: 1.24 mol%]
A-5: Styrene-butadiene copolymer [manufactured by Kraton Polymer Co., Ltd., product name “Kraton D1101”, polymerization ratio of monomer that induces unsaturated bond: 1.28 mol%]
A-6: Polyisobutylene rubber [manufactured by BASF, product name “Opanol B30”, polymerization ratio of monomer that induces unsaturated bond: 0%]
A-7: Butyl rubber [manufactured by JSR, product name “Butyl 365”, polymerization ratio of monomer that induces unsaturated bond: 2 mol%]
B-1: Benzophenone [manufactured by Tokyo Chemical Industry Co., Ltd.]
B-2: 1-hydroxy-cyclohexyl-phenyl-ketone [manufactured by Ciba Specialty Chemicals, product name “IRGACURE184”]
C-1: Trimethylolpropane triacrylate [manufactured by Shin-Nakamura Chemical Co., Ltd., product name “NK Ester A-TMPT”]
C-2: Trimethylolpropane trimethacrylate [manufactured by Shin-Nakamura Chemical Co., Ltd., product name “NK ester TMPT”]

  As can be seen from Table 1, a polyfunctional monomer is added to an olefin rubber obtained by polymerizing 0.005 to 1.5 mol% of a monomer that induces an unsaturated bond, followed by crosslinking by irradiation with ultraviolet rays. The release sheets of Examples 1 to 11 had a peel force in the range of 100 to 700 mN, and the curability test was good. On the other hand, Comparative Examples 1 to 8, which were not crosslinked, were poor in both peel strength and curability. In addition, Comparative Example 9 in which a polyfunctional monomer is added to an olefin rubber obtained by polymerization of 0 mol% and 2.0 mol% of a monomer that induces an unsaturated bond, and is crosslinked by irradiation with ultraviolet rays. No. 10 had very good curability but was very bad with a peel strength of 2300 mN / 25 mm or more.

  The release sheet of the present invention has no migration of the silicon compound to the pressure-sensitive adhesive layer surface, has excellent releasability, and migrates to the pressure-sensitive adhesive surface such as an adhesive sheet for electronic parts, label application, and semiconductor wafer processing pressure-sensitive adhesive sheet. The silicon compound is preferably used in applications where there is a problem.

Claims (7)

A release sheet used for protecting an adhesive layer of an adhesive sheet, which has a base sheet and a release agent layer, and the release agent layer induces an unsaturated bond in the molecule (A). Formed by irradiating active energy rays to an uncrosslinked rubber material layer containing an olefinic uncrosslinked rubber obtained by polymerizing 0.005 to 1.5 mol% of a monomer and (B) an electron withdrawing group-containing polyfunctional monomer. A release sheet, which is a cured layer.   The release sheet according to claim 1, wherein the active energy ray is ultraviolet rays, and the uncrosslinked rubber material layer further contains a photopolymerization initiator.   The release sheet according to claim 2, wherein the uncrosslinked rubber material layer contains a photopolymerization initiator in a proportion of 0.01 to 20 parts by mass with respect to 100 parts by mass of the olefin-based uncrosslinked rubber as the component (A).   The release sheet according to any one of claims 1 to 3, wherein the uncrosslinked rubber material layer comprises 0.1 to 30 parts by mass of component (B) with respect to 100 parts by mass of component (A).   The release sheet according to any one of claims 1 to 4, wherein the release agent layer has a thickness of 0.02 to 5.0 µm.   An olefin-based uncrosslinked rubber obtained by polymerizing 0.005 to 1.5 mol% of a monomer that induces an unsaturated bond in the molecule on the base sheet, and (B) a polyfunctional monomer containing an electron withdrawing group A method for producing a release sheet, comprising: applying a coating solution for forming a release agent layer containing, drying and providing an uncrosslinked rubber material layer;   The method for producing a release sheet according to claim 6, wherein the active energy ray is ultraviolet light, and the release agent layer forming coating solution further contains a photopolymerization initiator.