JPH10338846A - Pressure-sensitive adhesive sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sheet having good cuttability and transfer to an application pressure-sensitive adhesive sheet by laying release paper on a pressure- sensitive adhesive and forming a silicone resin release agent, a non-reactive release controlling agent and a reactive release controlling agent in a specified ratio on the surface of the release paper. SOLUTION: This sheet has a structure formed by laying a pressure-sensitive adhesive and release paper on one surface of a synthetic resin in the given order. The release agent laid on the surface of the release paper comprises 100 pts.wt. silicone resin of formula I, 0.05-2 pts.wt. non-reactive release controlling agent represented by formula II and having a weight-average molecular weight of 100-10,000 and 0.02-10 pts.wt. reactive release controlling agent of formula III. The synthetic resin sheet is desirably a vinyl chloride resin sheet for use as a sheet for decoration. The pressure-sensitive adhesive is desirably an acrylic one based on an acrylic copolymer. The sheet is produced by applying a solution of the pressure-sensitive adhesive to a synthetic resin sheet, drying the wet film to form a pressure-sensitive adhesive layer and laminating the assemblage with release paper.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-sensitive adhesive sheet which is excellent in cuttability by a cutting machine and excellent in transferability to an application pressure-sensitive adhesive sheet and is suitable for indoor or outdoor decoration or marking.

[0002]

2. Description of the Related Art Conventionally, an adhesive layer has been laminated on one surface of a synthetic resin sheet such as a vinyl chloride resin sheet, an acrylic resin sheet, a fluorine resin sheet, etc., which is transparent, translucent and opaque mainly containing a pigment. 2. Description of the Related Art A decorative pressure-sensitive adhesive sheet is known. This decorative adhesive sheet is used to apply a decorative effect to the material to be decorated by using an adhesive layer, and to exert a decorative effect by the color and pattern on the surface side. It is used in the field of display such as types, public notices and signs, and the field of fleet marking such as vehicle decoration.

The above-mentioned conventional decorative adhesive sheet has a structure in which an adhesive layer and a release paper are sequentially laminated on the back surface of a synthetic resin sheet, and this is usually provided by a computer-controlled cutting machine or manually. After cutting into shapes such as figures and letters, peeling off unnecessary parts in advance and leaving only necessary parts, it is further transferred to an application adhesive sheet and transferred to the adherend to be decorated It is constructed by the method.

[0004] However, the conventional decorative adhesive sheet has a problem that a necessary part is removed in a scrap removing operation after cutting by a cutting machine or a manual operation. A method of changing to a heavy peeling type and increasing the peeling strength between the adhesive and the release paper has been adopted.

In addition to the above, Japanese Patent Application Laid-Open No. 2-84476
In the gazette, in the dynamic peel resistance between the pressure-sensitive adhesive layer and the release layer of the release paper, by giving a speed dependence by limiting the peel strength at low speed peeling and high speed peeling respectively to a specific range, There is disclosed a pressure-sensitive adhesive sheet for a cutting machine in which "turn-up" generated near a cut portion is prevented.

However, the above-mentioned method of increasing the peel strength has a problem that the transferability is remarkably reduced when only the necessary portion is transferred to the application pressure-sensitive adhesive sheet after the unnecessary portion is peeled in advance. JP-A-2-84
The pressure-sensitive adhesive sheet for a cutting machine described in Japanese Patent No. 476 does not completely solve the same problem.

Further, there is a problem in that the adhesive strength after aging is reduced due to the adhesion of the bleed material to the surface of the pressure-sensitive adhesive with the silicone release agent. Is also desired.

The present invention has been made to solve the above problems, and as a result of intensive studies, it has been found that by adding a specific amount of a non-reactive release control agent to a release agent used for release paper, It was made by finding that the non-reactive release control agent attached to the cutter blade when the adhesive sheet was cut covered the cut surface of the adhesive and suppressed re-adhesion of the cut surface of the adhesive. is there.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a cut material and a good transfer property to an application pressure-sensitive adhesive sheet, and to have good stability over time without a decrease in the residual adhesive ratio, which is suitable for decoration. It is to provide an excellent adhesive sheet.

[0010]

Means for Solving the Problems The pressure-sensitive adhesive sheet of the present invention comprises:
An adhesive and release paper are laminated on one side of the synthetic resin sheet in this order, and the release agent laminated on the surface of the release paper is 100% by weight of a silicone resin having a specific structure. Parts, weight average molecular weight 100 to
10,000 non-reactive release control agent 0.05-
2 parts by weight and a reactive release control agent 0.2 to 10
It is characterized by consisting of parts by weight.

Hereinafter, the present invention will be described in detail. Synthetic Resin Sheet As the synthetic resin sheet used in the present invention, a general synthetic resin sheet base material conventionally used for a decorative sheet, a marking film or the like can be used, and is not particularly limited. Examples of such a synthetic resin sheet include, for example, a vinyl chloride resin sheet, an acrylic resin sheet, a urethane resin sheet, a fluorine resin sheet, and the like, but for decorative applications requiring flexibility and weather resistance. As such, a vinyl chloride resin sheet is preferable.

The synthetic resin sheet may be added with a plasticizer, an ultraviolet absorber, a heat stabilizer, a filler, a coloring agent, etc. in order to improve various performances.

The plasticizer is added for the purpose of imparting flexibility to the synthetic resin sheet. For example, phthalic acid-based plasticizers such as dioctyl phthalate, diisononyl phthalate, octyldecyl phthalate, and diisodecyl phthalate are used. Adipic acid plasticizers such as di-2-ethylhexyl adipate, diisononyl adipate, diisodecyl adipate, di-2-ethylhexyl azelate, di-2-ethylhexyl sebacate, tricresyl phosphate,
Trixylyl phosphate, tributyl phosphate, tri-phosphate
2-ethylhexyl, octyldiphenyl phosphate, chlorinated paraffin, chlorinated fatty acid esters, epoxidized soybean oil, and the like. Among them, epoxidized soybean oil also has the function of a heat stabilizer, and is suitable for producing a synthetic resin sheet by extrusion molding or calendering.

Examples of the ultraviolet absorber include salicylate-based, benzophenone-based, benzotriazole-based, and cyanoacrylate-based ultraviolet absorbers.

Examples of the heat stabilizer include metal soap heat stabilizers, organotin heat stabilizers, lead heat stabilizers, antimony heat stabilizers, and nonmetal heat stabilizers.
Examples of the metal soap-based heat stabilizer include Pb, C
Metal soaps composed of d, Ba, Zn, Ca and the like and stearic acid, lauric acid, ricinoleic acid, naphthenic acid, 2-ethylhexoic acid and the like, and specifically, Cd
/ Ba heat stabilizer, Ba / Zn heat stabilizer, Ca / Zn
Heat stabilizer, Ba / Pb heat stabilizer, Cd / Ba / Zn
Heat stabilizers, Cd / Mg / Zn heat stabilizers, and the like.

As the above-mentioned organotin heat stabilizer, for example, dibutyltin dilaurate, dibutyltin maleate, dibutyltin mercaptide and the like can be mentioned. Examples of the lead-based heat stabilizer include, for example, lead white, basic lead sulfite, tribasic lead sulfate, dibasic lead phosphite, dibasic lead phthalate, tribasic lead maleate, silica gel coprecipitated. Examples include lead silicate, dibasic lead stearate, lead stearate and the like.

The non-metallic heat stabilizer includes, for example,
(I) epoxidized vegetable oils such as epoxidized soybean oil and epoxidized linseed oil, epoxidized fatty acid esters, epoxidized alicyclic compounds, epoxy compounds such as bisphenol A diglycidyl ether and epoxidized polybutadiene;
(Ii) Trialkyl phosphites such as tributyl phosphite, triisooctyl phosphite, triisodecyl phosphite, trilauryl phosphite, monoisooctyl diphenyl phosphite, monoisodecyl diphenyl phosphite, diisooctyl monophenyl phosphite Phosphites such as alkylaryl phosphites such as phytite, triphenyl phosphite, tris (p-phenylphenyl) phosphite, and tris (o-cyclohexylphenyl) phosphite; and (iii) acetylacetone, benzoylacetone, benzoylpropionylmethane and the like. β-diketone and the like.

Examples of the filler include calcium carbonate, talc (basic magnesium silicate), kaolin (aluminum silicate), silica, titanium oxide and the like.

Examples of the colorant include organic pigments such as azo, phthalocyanine, sulene and dye lakes, oxides, molybdate chromate, sulfide / selenide, ferrocyanide, etc. And inorganic pigments.

As the method of producing the synthetic resin sheet, any conventionally known method is employed. In the case of a vinyl chloride resin, for example, a vinyl chloride resin sol is obtained by dispersing constituent components in an organic solvent, and A sol-casting method in which the composition is heated and cured after coating and drying on paper, and a calendering method in which the constituent components are heated and melted to form a sheet are exemplified. Examples of the organic solvent serving as a dispersion medium used in the sol casting method include toluene, xylene, methyl ethyl ketone, methyl amyl ketone, methyl isobutyl ketone, cyclohexanone, and the like,
Examples of commercially available products include “Solvesso” (manufactured by Mitsubishi Chemical Corporation).

Although the thickness of the synthetic resin sheet is not particularly limited, it is usually about 30 to 200 μm, more preferably about 40 to 100 μm. If the thickness of the synthetic resin sheet is too thin, it will lose its stiffness and the workability when used as a decorative sheet or a marking film may be reduced. In some cases, the ability to adhere to an adherend may be reduced.

Pressure-Sensitive Adhesives The pressure-sensitive adhesives used in the present invention include, for example, acrylic pressure-sensitive adhesives, rubber-based pressure-sensitive adhesives such as natural rubbers and synthetic rubbers, urethane-based pressure-sensitive adhesives, and silicone-based pressure-sensitive adhesives. In particular, an acrylic pressure-sensitive adhesive is preferably used because it has good weather resistance.

Hereinafter, a case where an acrylic pressure-sensitive adhesive is used will be described in detail. The acrylic pressure-sensitive adhesive contains an acrylic copolymer as a main component, and is preferably crosslinked with a crosslinking agent.

The acrylic copolymer is usually obtained by copolymerizing a mixed monomer mainly composed of an alkyl (meth) acrylate and a polar group-containing vinyl monomer.

The alkyl (meth) acrylate is preferably an alkyl (meth) acrylate having 4 to 14 carbon atoms in the alkyl group. Since the homopolymer has a glass transition temperature of -50 ° C. or lower, it can be used as a main component. Thus, the balance of pressure-sensitive adhesiveness and shear strength of the resulting acrylic pressure-sensitive adhesive can be kept high. Examples of the alkyl (meth) acrylate include n-butyl acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and n
-Octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl (meth) acrylate,
Examples include isononyl (meth) acrylate and lauryl (meth) acrylate, which may be used alone or in combination of two or more.

When the content of the alkyl (meth) acrylate is small, the cohesive strength is increased and sufficient pressure-sensitive adhesiveness is hardly obtained, and when the content is large, the cohesive strength is low and sufficient shear strength is hardly obtained. Therefore, in the mixed monomer, preferably 50 to 98% by weight, more preferably 70 to 98% by weight.
~ 95% by weight.

The polar group-containing vinyl monomer includes:
For example, carboxyl group-containing vinyl monomers such as (meth) acrylic acid, itaconic acid, crotonic acid, (anhydrous) maleic acid, fumaric acid, carboxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl Hydroxyl-containing vinyl monomers such as (meth) acrylate, caprolactone modified (meth) acrylate, polyethylene glycol (meth) acrylate, and polypropylene glycol (meth) acrylate, (meth) acrylonitrile, N-vinylpyrrolidone, N-vinylcaprolactam, N-vinyl Lauriloractam, (meth) acryloylmorpholine, (meth) acrylamide, dimethyl (meth) acrylamide, N-
Methylol (meth) acrylamide, N-butoxymethyl (meth) acrylamide, dimethylaminopropyl (meth) acrylamide, dimethylaminomethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, diethylaminoethyl ( Examples thereof include nitrogen-containing vinyl monomers such as meth) acrylate, and these may be used alone or in combination of two or more.

If the content of the polar group-containing vinyl monomer is low, the cohesive strength is reduced and it is difficult to obtain a shear strength, and if the content is too large, the cohesive force is high and it is difficult to obtain pressure-sensitive adhesiveness. Medium, preferably 2
-50% by weight, more preferably 5-30% by weight.

The mixed monomer may contain another vinyl monomer in addition to the alkyl (meth) acrylate and the polar group-containing vinyl monomer, and may be copolymerized. For example, vinyl acetate, vinyl propionate, styrene, Isobornyl (meth) acrylate;

When the content of the above-mentioned other vinyl monomer increases, the cohesive strength becomes high, and it becomes difficult to obtain sufficient pressure-sensitive adhesiveness. It is at most 50% by weight, more preferably at most 30% by weight.

Examples of the method for copolymerizing the above-mentioned mixed monomer include all polymerization methods such as solution polymerization, emulsion polymerization, suspension polymerization and bulk polymerization, and include (meth) acrylic acid and hydroxyalkyl (meth) acrylate. Solution polymerization is preferred because the carboxyl group-containing vinyl monomer has good copolymerizability, is easy to control the coating viscosity, and is easily mixed with a crosslinking agent, a tackifying resin and the like.

In the above solution polymerization, a thermal polymerization initiator is generally used. Examples of the thermal polymerization initiator include ketone peroxides such as methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide and cyclohexanone peroxide, isobutyryl peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, and P-chloro. Diacyl peroxides such as benzoyl peroxide, diisopropylbenzene hydroperoxide, hydroperoxides such as t-butyl hydroperoxide,
Dialkyl peroxides such as 2,5-dimethyl-2,5-di- (t-butylperoxy) hexane, 1,3-bis- (t-butylperoxyisopropyl) benzene, and di-t-butyl peroxide , 1,1-di-
(T-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-di- (t-butylperoxy)
Peroxyketals such as cyclohexane, t-butylperoxypivalate, t-butylperoxy-2-
Alkyl peresters such as ethylhexanoate and t-butylperoxyisobutyrate, di-2-ethylhexylperoxydicarbonate, bis- (4-t-
In addition to organic peroxides such as percarbonates such as butylcyclohexyl) peroxydicarbonate,
2'-azobis-isobutyronitrile, 2,2'-azobis-2-methylbutyronitrile, 2,2'-azobis-2,4-dimethylvaleronitrile, 1,1'-azobis-1-cyclohexanecarbo Nitrile, dimethyl-
Examples include azobis compounds such as 2,2'-azobisisobutyrate, 4,4'-azobis-4-cyanovaleric acid, and 2,2'-azobis- (2-aminopropane) dihydrochloride.

When the acrylic copolymer is obtained, a chain transfer agent may be added to the mixed monomer for the purpose of suppressing the dispersion of the polymerization reaction and appropriately controlling the molecular weight.
Examples of the chain transfer agent include n-dodecyl mercaptan, 2-mercaptoethanol, β-mercaptopropionic acid, octyl β-mercaptopropionate, β
-Methoxybutyl mercaptopropionate, trimethylolpropane tris (β-thiopropionate), butyl thioglycolate, thiol compounds such as propanethiols, butanethiols, thiophosphites, and halogen compounds such as carbon tetrachloride. Is mentioned.

The weight average molecular weight (Mw) of the acrylic copolymer obtained above is measured as a standard polystyrene equivalent molecular weight by a gel permeation chromatography (GPC) method. Specifically, the acrylic copolymer before cross-linking is referred to as tetrahydrofuran (hereinafter referred to as “THF”).
To make a 0.5-1.0% by weight solution,
It is separated by a gel packed column using F as a dispersion medium, and is determined from the relationship between the elution time and the refractive index of the elution solution.

When the weight average molecular weight (Mw) of the acrylic copolymer is small, it is difficult to obtain a sufficient cohesive force, and when the weight average molecular weight (Mw) is large, the initial adhesiveness is reduced, and it is difficult to press and adhere to a corrugated plate or the like. Therefore, 400,000 to 1,000,000 is preferable.

The crosslinking agent used for crosslinking the acrylic copolymer varies depending on the type of the polar group-containing vinyl monomer copolymerized in the acrylic copolymer. When a carboxyl group-containing vinyl monomer is copolymerized as a polar group-containing vinyl monomer, an epoxy-based cross-linking agent, an aziridine-based cross-linking agent, or the like is suitably used. It is preferably used.

As the epoxy-based crosslinking agent, for example,
Examples include ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, and 1,6-hexanediol diglycidyl ether. Examples of the aziridine-based crosslinking agent include N, N-hexamethylene-1,6-bis (1 -Aziridinecarboxamide) and the like, and as the isocyanate-based crosslinking agent, for example, tolylene diisocyanate (TDI),
Naphthylene-1,5-diisocyanate, diphenylmethane diisocyanate (MDI), hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), xylene diisocyanate (XD
I) and trimethylolpropane modified TDI.

When the amount of the cross-linking agent is small, it is difficult to obtain a sufficient degree of cross-linking. For this reason, it is difficult to obtain a sufficient shear strength with a decrease in cohesive force. Is impaired, and it becomes difficult to obtain sufficient pressure-sensitive adhesiveness. For this reason, the addition amount is preferably 0.01 to 5 parts by weight, more preferably 0.05 to 5 parts by weight, based on 100 parts by weight of the solid content of the acrylic copolymer.
3 parts by weight.

If the gel fraction of the acrylic pressure-sensitive adhesive is too low, no cohesive strength can be obtained, and particularly when the acrylic pressure-sensitive adhesive is applied to a curved plate or the like, peeling or swelling tends to occur. Therefore, it is preferable to crosslink so as to be 40 to 65% by weight.

Other additives may be added to the acrylic pressure-sensitive adhesive as needed as long as other physical properties are not reduced, and examples thereof include a tackifier resin and a filler.

As the tackifying resin, for example, C5
-Based and C9-based petroleum resins, rosin resins, rosin ester resins, terpene resins, terpene phenol resins, cumarone-indene resins, disproportionated rosin resins, disproportionated rosin ester resins, polymerized rosin resins, polymerized rosin ester resins, or a mixture thereof. All tackifying resins such as hydrogenated products are included. The above tackifier resins may be used alone or in combination of two or more.

Since the tackifying resin is an uncrosslinked component in the acrylic pressure-sensitive adhesive, if the amount of addition is large, the cohesive strength is reduced, and sufficient shear strength cannot be obtained. For this reason, the addition amount is preferably 30 parts by weight or less based on 100 parts by weight of the acrylic copolymer.

Examples of the filler include calcium carbonate, talc (basic magnesium silicate), kaolin (aluminum silicate), silica and the like.

When the glass transition temperature of the acrylic pressure-sensitive adhesive is low, the glass has a sticky feeling during construction in summer, and when the glass transition temperature is high, the adhesiveness in winter decreases, and the glass transition temperature of the release agent laminated on the surface of the release paper described later is reduced. The temperature is preferably −20 to 10 ° C. because the non-reactive release control agent bleeds out, resulting in a large decrease in the residual adhesion rate.

When the thickness of the pressure-sensitive adhesive layer is small, sufficient adhesion to an adherend cannot be obtained, and when the thickness is large, cohesive failure occurs in the side stick or the pressure-sensitive adhesive layer.
μm is preferred.

Release Paper The release paper used in the present invention is a paper in which a release agent is laminated on at least one surface of a usual base material. In particular, the release agent is a silicone resin represented by the following formula (1). 100 parts by weight,
Weight average molecular weight of 100 to 10,000 represented by the following formula (2)
A non-reactive release control agent represented by the following formula (3): 0.05 to 2 parts by weight and a reactive release control agent represented by the following formula (3): 0.2 to 10 parts by weight.

[0047]

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Examples of the base material include paper base materials such as high-quality paper, kraft paper, and glassine paper; woven fabric; nonwoven fabric; synthetic fiber; net; plastic film; Things.

The release agent comprises a silicone resin having a specific structure, a non-reactive release control agent and a reactive release control agent, and the silicone resin represented by the following formula (1) is used. Used.

[0050]

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Commercial products of the above silicone resins include:
"Shin-Etsu Silicone KS-770", "Shin-Etsu Silicone K
S-775 "," Shin-Etsu Silicone KS-776A ",
"Shin-Etsu Silicone KS-778", "Shin-Etsu Silicone K
S-843 "(all manufactured by Shin-Etsu Chemical Co., Ltd.).

The non-reactive release control agent is added to control the release strength of the release paper, and has a weight average molecular weight of 100 to 10,000 represented by the following formula (2).
0 is used.

[0053]

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Commercially available non-reactive release control agents include Shin-Etsu Silicone X-92-128 (Shin-Etsu Chemical Co., Ltd., weight average molecular weight: about 2000).

The amount of the non-reactive release control agent added is
If the amount is small, the peel strength is reduced, the scrap removal property is reduced, and if the amount is large, the residual adhesive rate is reduced, and the initial adhesive strength at the time of the application is reduced. 2 parts by weight, preferably 0.1
To 1 part by weight, more preferably 0.5 to 0.9 part by weight.

The reactive release control agent is added in order to reduce the amount of the non-reactive release control agent which tends to cause a decrease in the residual adhesion rate to a small amount.
One represented by the following formula (3) is given.

[0057]

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As a commercially available reactive release control agent, “Shin-Etsu Silicone X-92-183” (the following formula (4))
Shin-Etsu Silicone K-380)
0 "(corresponding to the following formula (5), manufactured by Shin-Etsu Chemical Co., Ltd.).

[0059]

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When the amount of the reactive release control agent is small, the peel strength is low, and the debris removing property is reduced. When the amount is large, the peel strength is high, and the sheet is liable to be cut during the debris removal. 0.2 to 10 parts by weight, preferably 0.1 to 10 parts by weight, based on 100 parts by weight of the silicone resin.
It is 5 to 7 parts by weight, more preferably 1 to 5 parts by weight.

The silicone resin needs to be applied to a substrate as a mixture with a non-reactive release control agent and a reactive release control agent, dried, and then cured by heating. System catalyst,
A commercially available product of the platinum-based catalyst includes a product number “CAT-PL-50T” (manufactured by Shin-Etsu Chemical Co., Ltd.).

Examples of the method of applying the release agent having the above constitutional requirements to the substrate include all ordinary methods for applying a liquid material, such as a gravure coater, a Meyer bar coater, a multi-stage roll, and an air knife coater. And the like.

The heating conditions for curing are as follows:
The temperature is preferably 60 ° C. or more at 0 ° C., 40 seconds or more at 100 ° C., and 30 seconds or more at 120 ° C.

The thickness of the release agent layer is preferably 0.5 to 2 μm, because if it is thin, it will be difficult to obtain release performance, and if it is thick, the release agent layer will easily fall off due to poor curing.

If the total thickness of the release paper after laminating the release agent layer is too thin, it may be difficult to handle the entire sheet, and if it is too thick, the workability when peeling off the release paper may be reduced. There is. Therefore, the thickness of the release paper is usually 80
To 300 μm, preferably 100 to 200 μm.

Method for Producing a Pressure-Sensitive Sheet The pressure-sensitive adhesive sheet of the present invention has a pressure-sensitive adhesive and release paper laminated on one surface of a synthetic resin sheet in this order. The method for producing the pressure-sensitive adhesive sheet is not particularly limited, and after applying a pressure-sensitive adhesive solution to one surface of a synthetic resin sheet, the pressure-sensitive adhesive layer may be laminated by drying, and then laminated with a release paper. Alternatively, an adhesive solution may be applied to one side of the release paper, dried, and laminated with a synthetic resin sheet.

[0067]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail with reference to the following non-limiting examples. (Examples 1 to 4 and Comparative Examples 1 to 4) Synthetic resin sheet (vinyl chloride resin sheet) Vinyl chloride resin (trade name "PSH-1" manufactured by Kaneka Chemical Co., Ltd. )
0 ", degree of polymerization 1,200) 100 parts by weight, adipic acid-based plasticizer (trade name" PN-250 ", manufactured by Asahi Denka Co., Ltd.) 30 parts by weight, benzotriazole-based ultraviolet absorber (Ciba Geigy," Tinuvin P ") 1) 1 part by weight of xylene and 100 parts by weight of xylene are uniformly mixed and then coated on process paper.
After drying, heat and cure at 200 ° C for 5 minutes to a thickness of 50μ.
m was obtained.

Acrylic pressure-sensitive adhesive In a separable flask equipped with a reflux condenser, a thermometer and a stirrer, 70 parts by weight of n-butyl acrylate, 16.8 parts by weight of 2-ethylhexyl acrylate, 1 part of acrylic acid
3 parts by weight, 2-hydroxyethyl methacrylate 0.2
Parts by weight and 0.01 parts by weight of n-dodecyl mercaptan were added together with 80 parts by weight of ethyl acetate, and the temperature was raised to reflux while purging with nitrogen gas and held. Next, a 5% by weight solution of benzoyl peroxide in ethyl acetate was added.
First, 0.1 part by weight, 0.1 part by weight after 30 minutes, 0.2 part by weight after 1 hour and 30 minutes, and then 3 parts by weight
After the time, 0.8 parts by weight was added dropwise over 30 minutes, and after the entire amount was added, the mixture was polymerized for further 5 hours to obtain a solution of an acrylic copolymer. The weight average molecular weight (Mw) of each of the acrylic copolymers was determined by gel permeation chromatography (GPC), and the molecular weight was 800,000.

The acrylic copolymer has a solid content of 1%.
To 100 parts by weight of an acrylic pressure-sensitive adhesive, an isocyanate-based crosslinking agent (manufactured by Nippon Polyurethane Co., Ltd., trade name "Coronate L-55E") was added at a solid content of 1.5 parts by weight and uniformly mixed. A solution was obtained. The solution of the acrylic pressure-sensitive adhesive was applied to the release surface of a release substrate, and the glass transition temperature of the dried acrylic pressure-sensitive adhesive determined by a viscoelastic spectrum method was 5.0 ° C.

Release paper In accordance with the composition shown in Table 1, a non-reactive release control agent (manufactured by Shin-Etsu Chemical Co., Ltd., product number "Shin-Etsu Silicone X-92-") was added to a silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd .; 128 ", weight average molecular weight 2,000)
And / or a reactive release control agent (manufactured by Shin-Etsu Chemical Co., Ltd., product number “Shin-Etsu Silicone X-92-183”, weight average molecular weight 5,000), and a curing catalyst (manufactured by Shin-Etsu Chemical Co., product number “CAT”) -PL-50T ") at a ratio of 100: 1 in terms of solid content to obtain a solution of a release agent.

Then, 25 μm on both sides of 120 μm high quality paper
After laminating polyethylene having a thickness of 1 μm, the solution of the release agent was dried using a gravure coater to a thickness of 1 μm.
After coating on both sides so that it becomes
Each release paper subjected to a double-sided release treatment was obtained.

[0072] According to the pressure-sensitive adhesive sheet table 1, a thickness after drying a solution of the acrylic pressure-sensitive adhesive to the release paper was coated with a 30 [mu] m, 120 ° C.
After drying in an oven for 5 minutes, the above-mentioned vinyl chloride-based resin sheet was adhered to this adhesive surface using a heating roll at 40 ° C. to obtain each adhesive sheet.

(Evaluation of Examples and Comparative Examples) With respect to the pressure-sensitive adhesive sheets obtained in the above Examples and Comparative Examples, cutability, application pressure-sensitive adhesive sheet transferability, peel strength between release paper and pressure-sensitive adhesive were measured by the methods described below. And the residual adhesion ratio between the release paper and the adhesive after heat aging was measured.

The adhesive sheet thus obtained was cut into a cutting machine “CG-4”.
Using "5" (manufactured by Mimaki), four sets of characters "Sekisui Chemical" in 30 mm x 30 mm size were cut in a total of 24 characters, and after 1 minute, 30 minutes, and 3 hours, debris was removed and required. The cutability was evaluated by determining the number of remaining characters.

Application Adhesive Sheet Transfer Property The obtained adhesive sheet was sufficiently pressed with an application adhesive sheet (product number: AP217, manufactured by Sekisui Chemical Co., Ltd.) using a squeegee for the 12 characters remaining on the release paper due to scrap removal. Then, the state of transfer at the time of peeling after standing for 10 minutes was evaluated in the following five stages. [Evaluation criteria] 5: Transfer all 12 characters 4: Transfer 11 characters or not transfer dots etc. 3: Transfer 7 to 10 characters 2: Transfer 1 to 6 characters 1: Do not transfer characters

Peel strength between release paper and adhesive The obtained adhesive sheet was cut into a 50 mm width, and the peel strength between the release paper and the adhesive at a peel speed of 1000 mm / min was measured using a tensile tester. .

Residual contact between release paper and adhesive after heat aging
The obtained pressure-sensitive adhesive sheet is cut into a width of 50 mm, heat-aged in a constant temperature room at 70 ° C. for 10 days, and then peeled off between the release paper and the adhesive at a peeling speed of 1000 mm / min using a tensile tester. The strength was measured, and the residual adhesion rate (%) was calculated from “peel strength after heat aging / peel strength before heat aging”.

[0078]

[Table 1]

[0079]

According to the present invention, the release agent laminated on the release paper contains a specific amount of a specific silicone resin, a non-reactive release control agent and a reactive release control agent, respectively. After cutting at high speed with a computer-controlled cutting machine, re-adhesion of the adhesive cut surface is unlikely to occur even when left unattended. The transferability is also good. In addition, since the content of the non-reactive release control agent was suppressed by using the reactive release control agent in combination, a decrease in the residual adhesion rate did not easily occur, and the stability over time was excellent.

Claims (1)

[Claims] 1. A pressure-sensitive adhesive sheet in which a pressure-sensitive adhesive and release paper are laminated on one surface of a synthetic resin sheet in this order, wherein the release agent laminated on the surface of the release paper is represented by the following formula (1). 100 parts by weight of a silicone resin, and a weight average molecular weight of 100 to 10,000 represented by the following formula (2)
And 0.05 to 2 parts by weight of a non-reactive release control agent and a reactive release control agent represented by the following formula (3):
An adhesive sheet comprising 2 to 10 parts by weight. Embedded image