JPH10168408A - Self-adhesive tape or sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a self-adhesive tape or sheet which is excellent in light resistance, does not stain an adherend, and is free from degradation in self- adhesiveness due to a plasticizer by incorporating a specific ultraviolet-absorbing graft copolymer into a self-adhesive layer mainly comprising a rubber and an acrylic ester copolymer. SOLUTION: An ultraviolet absorbent incorporated into the self-adhesive layer is an ultraviolet-absorbing graft copolymer obtd. by the graft polymn. of a vinyl compd. onto a macromer having ultraviolet-absorbing monomer units and/or an ultraviolet-absorbing graft copolymer obtd. by the graft polymn. of an ultraviolet-absorbing monomer onto a macromer. A graft copolymer having side chains contg. ultraviolet-absorbing monomer units is pref. in terms of the desired effects. 2-[2'-Hydroxy-5'-(methacryloxy)phenyl]benzotriazole and 2-[2'-hydroxy-5'-(acryloyloxy)phenyl]benzotriazole are examples of the ultraviolet-absorbing monomer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive tape or sheet. More specifically, the present invention relates to a pressure-sensitive adhesive tape or sheet having excellent light fastness, no adherend contamination, and excellent plasticizer resistance.

[0002]

2. Description of the Related Art It is generally known that, among the rays of sunlight, the shorter the wavelength of light, the greater the energy thereof. Ultraviolet rays contained in a wavelength range of about 10 to 400 nm are more visible than long-wavelength visible rays and infrared rays. Has a large energy, for example, has enough energy to excite or break molecular bonds of plastics and organic compounds. Therefore, ultraviolet rays cause discoloration of various industrial products made of, for example, decorative steel plates, signboards, color photographs, or polymer materials, or cause their strength and performance to decrease. In order to protect or maintain the performance of industrial products by cutting or absorbing such ultraviolet rays, generally, an inorganic ultraviolet shielding film is provided on the surface of the industrial products, or an organic ultraviolet ray is contained in the products. A method of adding and mixing an absorbent has been used.

The latter method is generally used for pressure-sensitive adhesives. However, in the method of adding and mixing a low-molecular-weight organic UV absorber, an effective UV-shielding effect is required for the pressure-sensitive adhesive. It is necessary to increase the amount of the ultraviolet absorber added, and, with time, the ultraviolet absorber bleeds on the surface of the adherend of the adhesive, and the shielding effect is not maintained,
There is a problem that the surface of the adherend is contaminated.

[0004] Further, the pressure-sensitive adhesive sheet used for outdoor use often uses a soft polyvinyl chloride film, and includes a substrate or a pressure-sensitive adhesive in which a plasticizer is added. Due to the influence of these plasticizers, there is a problem in that the pressure-sensitive adhesive changes over time, and the adhesive strength is reduced.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a pressure-sensitive adhesive tape or sheet having excellent light fastness, no contamination on adherends, excellent plasticizer resistance and no decrease in adhesive strength. I have.

[0006]

The pressure-sensitive adhesive tape or sheet according to the present invention is a pressure-sensitive adhesive tape or sheet having a pressure-sensitive adhesive layer containing a rubber and / or an acrylate copolymer as a main component on one surface of a substrate. , The pressure-sensitive adhesive layer,
(A) an ultraviolet-absorbing graft copolymer obtained by graft-polymerizing a vinyl compound copolymerizable with the macromer to a macromer having an ultraviolet-absorbing monomer unit, and / or (b) at least an ultraviolet-absorbing monomer, A UV-absorbing graft copolymer obtained by graft polymerization.

The pressure-sensitive adhesive tape or sheet according to the present invention comprises a pressure-sensitive adhesive tape or sheet having a pressure-sensitive adhesive layer formed on one surface of a substrate, wherein the pressure-sensitive adhesive layer comprises, as a main component, (c)
An adhesive UV-absorbing graft copolymer obtained by graft-polymerizing at least 2-ethylhexyl acrylate or butyl acrylate onto a macromer having a UV-absorbing monomer unit, and / or (d) a UV-absorbing monomer and at least 2-ethylhexyl acrylate Alternatively, it is characterized by containing an adhesive UV-absorbing graft copolymer obtained by graft-polymerizing butyl acrylate with a macromer.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION In order to solve the above-mentioned problems, as a result of intensive studies on an ultraviolet absorber used for an adhesive layer, (a) a macromer having an ultraviolet-absorbing monomer unit, By using an ultraviolet-absorbing graft copolymer obtained by graft-polymerizing a copolymerizable vinyl compound, or (b) an ultraviolet-absorbing graft copolymer obtained by graft-polymerizing at least an ultraviolet-absorbing monomer to a macromer, Excellent light fastness,
It has been found that a pressure-sensitive adhesive tape or sheet having no adherend contamination and having excellent plasticizer resistance and no decrease in adhesive strength can be obtained. As the pressure-sensitive adhesive of the present invention, a rubber-based pressure-sensitive adhesive or a pressure-sensitive adhesive mainly containing an acrylate-based copolymer is used.

The graft copolymer containing an ultraviolet-absorbing monomer unit used in the present invention includes a graft copolymer containing an ultraviolet-absorbing monomer unit in a side chain and a graft copolymer containing an ultraviolet-absorbing monomer unit in a main chain. These can be used in combination. From the viewpoint of the effect, those containing an ultraviolet absorbing monomer in the side chain are preferably used. By using the ultraviolet-absorbing graft copolymer of the present invention, there is no adherend contamination, and the reason why excellent effects such as light resistance and plasticizer resistance can be obtained cannot be described unconditionally. It is considered that by having a polymerized portion made of a vinyl compound having good compatibility with the agent at the terminal, the polymer is present more uniformly and it is difficult to form crystals or the like for a long period of time.

As a method for polymerizing the graft copolymer in the present invention, for example, when an ultraviolet absorbing monomer unit is contained in a side chain, first, an ultraviolet absorbing monomer and, if necessary, other monomers are polymerized to obtain a known method. As a result, a macromer having a vinyl group at only one end is obtained, and the copolymerization monomer is polymerized in the presence of the macromer. When the main chain contains an ultraviolet-absorbing monomer unit, first, a copolymerized monomer is polymerized to form a macromer having a vinyl group only at one end, and the ultraviolet-absorbing monomer and another monomer as necessary are polymerized in the presence of the macromer. I do.

As a method for producing a macromer, for example, a copolymerizable vinyl compound is polymerized together with a chain transfer agent having an alcoholic hydroxyl group or a carboxyl group to obtain a polymer (or oligomer) having a functional group at one terminal, Reacted with an isocyanate compound such as isocyanate, and further, hydroxyethyl (meth) acrylate,
By reacting with a vinyl compound such as (meth) acrylic acid, a macromer having a (meth) acryloyl group at one end can be obtained. Also, by using an ultraviolet-absorbing monomer in the copolymerized vinyl compound, an ultraviolet-absorbing macromer having a vinyl group at one end can be obtained in the same manner as described above.

The UV-absorbing monomer used in the present invention includes 2- [2'-hydroxy-5 '-(methacryloxy) phenyl] benzotriazole,
[2′-Hydroxy-5 ′-(acryloyloxy) phenyl] benzotriazole, 2- [2′-hydroxy-3′-t-butyl-5 ′-(methacryloyloxy)
Phenyl] benzotriazole, 2- [2′-hydroxy-3′-methyl-5 ′-(acryloyloxy) phenyl] benzotriazole, 2- [2′-hydroxy-
5 '-(methacryloyloxypropyl) phenyl]-
5-chlorobenzotriazole, 2- [2'-hydroxy-5 '-(methacryloyloxyethyl) phenyl]
Benzotriazole, 2-[-hydroxy-5 '-(acryloyloxyethyl) phenyl] benzotriazole, 2- [2'-hydroxy-3'-t-butyl-5'
-(Methacryloyloxyethyl) phenyl] benzotriazole, 2- [2'-hydroxy-3'-methyl-
5 '-(acryloyloxyethyl) phenyl] benzotriazole, 2- [2'-hydroxy-5'-(methacryloyloxypropyl) phenyl] -5-chlorobenzotriazole, 2- [2'-hydroxy-5'-
Benzotriazoles such as (acryloyloxybutyl) phenyl] -5-methylbenzotriazole and [2-hydroxy-3-t-butyl-5- (acryloyloxyethoxycarbonylethyl) phenyl] benzotriazole can be exemplified.

Further, 2-hydroxy-4-acryloyloxybenzophenone, 2-hydroxy-4-methacryloyloxybenzophenone, 2-hydroxy-4-
(2-acryloyloxy) ethoxybenzophenone,
Benzophenones such as 2-hydroxy-4- (2-methacryloyloxy) ethoxy benzophenone and 2-hydroxy-4- (2-methyl-2-acryloyloxy) ethoxybenzophenone can be exemplified.

In the present invention, the copolymerizable vinyl compound used for forming the main chain or side chain of the graft copolymer includes (meth) acrylic acid such as alkyl acrylate and alkyl methacrylate. Examples include vinyl monomers such as esters, alkyl vinyl ethers, alkyl vinyl esters, acrylonitrile, styrene, and vinyl acetate (hereinafter, copolymerized monomers), and these can be used alone or in combination. Specific examples of (meth) acrylates include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, lauryl acrylate, stearyl acrylate, methyl methacrylate, butyl methacrylate, t-butyl methacrylate, and 2-ethyl Hekyl methacrylate, lauryl methacrylate, stearyl methacrylate and the like are shown. Among these, monomers preferably used include methyl methacrylate, acrylonitrile, which have a relatively high glass transition point (Tg), good plasticizer resistance, and are easily copolymerized.
There are styrene and the like. The ratio of the UV-absorbing monomer to the copolymerizable monomer cannot be determined unconditionally depending on the required light resistance and the degree of plasticizer resistance, but the ratio of the UV-absorbing monomer / copolymerizing monomer is 10/100 to 80/100, Preferably, it is 30/100 to 50/100.

The copolymerization of the macromer and the monomer can be performed by a known method. For example, a macromer, a monomer, and a polymerization initiator are dissolved in a solvent such as toluene, ethyl acetate, tetrahydrofuran, and methyl ethyl ketone, and polymerization is started by heating to obtain a graft copolymer.
As the polymerization initiator, known azo compounds such as azobisisobutylnitrile and peroxides such as benzoyl peroxide can be used.

In the present invention, a rubber-based or acrylate-based copolymer is used as a main component of the pressure-sensitive adhesive, and examples thereof include natural rubber, isoprene rubber, styrene-butadiene rubber, styrene-butadiene block copolymer,
A rubber-based pressure-sensitive adhesive composed of a styrene-isoprene block copolymer or the like, and 2-ethylhexyl acrylate;
(Co) of vinyl monomers such as butyl acrylate, ethyl acrylate, vinyl acetate and methyl methacrylate
An acrylic ester-based pressure-sensitive adhesive made of a polymer can be exemplified. These pressure-sensitive adhesive base agents can be used in combination as appropriate, and if necessary, a tackifier resin, a softener, various pigments,
It is used by adding an auxiliary agent such as a viscosity modifier.

As the tackifier resin, generally known resins are used, and are appropriately selected from rosin ester resins having a softening point of 75 ° C. or higher, polyterpene resins, petroleum resins and the like. For example, disproportionated rosin esters such as superesters A-75, A-100, A-115, and A-125 manufactured by Arakawa Chemical Industries, Ltd., Clearon P-85, P manufactured by Yasuhara Yushi Kogyo Co., Ltd. -105, P-115, P-125
Hydrogenated polyterpene resin, such as Alcon P-90, P-100, P-115, P-1 manufactured by Arakawa Chemical Industries, Ltd.
And hydrogenated aliphatic cyclic petroleum resins such as P. 135 and P-135. These tackifier resins can be used alone or in combination.

The softener adjusts the wettability and flexibility of the pressure-sensitive adhesive. For example, polybutenes HV-50, HV-100, HV-300, HV manufactured by Nippon Petrochemical Co., Ltd.
Polybutene such as -1000 and liquid polyisobutylene, Diana Process Oil PW manufactured by Idemitsu Kosan Co., Ltd.
90, AC-460 and other paraffinic or aromatic process oils, Superester L and Superester A-18 manufactured by Arakawa Chemical Industry Co., Ltd., and Daimalon manufactured by Yasuhara Yushi Kogyo Co., Ltd. have a softening point of 20. Rosin esters or polyterpenes below ℃ can be used.

In the present invention, the blending ratio of the ultraviolet-absorbing graft copolymer and the pressure-sensitive adhesive cannot be specified unconditionally due to the required light resistance and plasticizer resistance. / 100 to 50/100, preferably 1
0/100 to 30/100.

The crosslinking agent blended for the purpose of improving the cohesive strength of the pressure-sensitive adhesive composition of the present invention or improving the anchoring property with the substrate includes:
Known ones in the art are used, for example, (1) isocyanate compounds: diisocyanates such as tolylene diisocyanate, xylene diisocyanate, hexamethylene dissocyanate, adducts of these diisocyanates with trimethylolpropane, and diisocyanates (2) Epoxy compounds: sorbitol polyglycidyl ether, pentaerythritol polyglycidyl ether, trimethylolpropane polyglycidyl ether, 1,6-hexane diglycidyl ether, etc. And (3) metal chelate compounds: various alkoxides of aluminum or titanium, and (4) melamine compounds: trimethylolmelamine, hexamethylolmelamine, and the like. The pressure-sensitive adhesive composition in the present invention is preferably used for pressure-sensitive adhesive sheets and tapes of a transparent substrate, and generally does not contain a filler such as a pigment, but if necessary, in a range that does not impair the effects of the present invention. , A pigment and the like can be appropriately compounded.

As a result of further study, it has been found that, in a pressure-sensitive adhesive tape or sheet having a pressure-sensitive adhesive layer formed on one surface of a substrate, at least 2-ethylhexyl is added to (c) a macromer having an ultraviolet absorbing monomer unit as a pressure-sensitive adhesive component of the pressure-sensitive adhesive layer. Adhesive UV-absorbing graft copolymer obtained by graft-polymerizing acrylate or butyl acrylate, or adhesive UV-absorbing polymer obtained by graft-polymerizing (d) a UV-absorbing monomer and at least 2-ethylhexyl acrylate or butyl acrylate to a macromer By using the graft copolymer, the adhesive property can be easily controlled, the light resistance is excellent, the adherend is not contaminated, and the adhesive tape or sheet which is excellent in the plasticizer resistance and has no decrease in the adhesive strength can be obtained. It has been found. Where the macromer,
Alternatively, a macromer having an ultraviolet absorbing monomer unit can be obtained in the same manner as in the case of the above-mentioned ultraviolet absorbing graft copolymer. In addition, by appropriately selecting a vinyl compound and increasing the glass transition point of the macromer portion, it is possible to improve the plasticizer resistance of the resulting tacky ultraviolet ray absorbing graft copolymer.

That is, the adhesive UV-absorbing graft copolymer comprises a UV-absorbing monomer and 2-ethylhexyl acrylate and / or butyl acrylate as essential components, and, if necessary, methyl methacrylate, methyl acrylate, ethyl acrylate and styrene. And other functionalizable monomers such as vinyl acetate and other copolymerizable monomers, carboxyl group-containing monomers, hydroxyl group-containing monomers, amino group-containing monomers and glycidyl group-containing monomers. The ultraviolet-absorbing monomer unit may be contained in either the main chain or the side chain of the graft polymer, but is preferably contained in the side chain from the viewpoint of adhesive properties and control of polymerization.

As the UV-absorbing monomer, the same UV-absorbing monomer as used in the above-mentioned UV-absorbing graft copolymer is used. The compounding ratio of the UV-absorbing monomer in the adhesive UV-absorbing graft copolymer is as follows: Usually 1-3
0% by weight, preferably 3 to 15% by weight. If the compounding ratio is less than 1% by weight, the effect of absorbing ultraviolet light is insufficient, and if it exceeds 30% by weight, it becomes difficult to control the adhesive properties and the cost becomes high.

Also, 2-ethylhexyl acrylate,
And butyl acrylate are used alone or in combination, and the blending ratio in the adhesive UV-absorbing graft copolymer varies depending on the required adhesiveness, the glass transition point of other copolymerizable monomers, and the like. Although it cannot be said, the total amount of both monomers is usually 50% by weight or more, preferably 60 to 85% by weight. If the amount is less than 50% by weight, the adhesive strength becomes insufficient, and a desired adhesive UV-absorbing graft copolymer may not be obtained.

The adhesive UV-absorbing graft copolymer of the present invention can be cross-linked by adding the above-mentioned functional group-containing monomer as an active site by adding a cross-linking agent.
Especially for applications requiring re-peelability and high cohesion,
It is preferable to add a crosslinking agent. For example, the above-mentioned (1) isocyanate compound, (2) epoxy compound, (3) metal chelate compound, (4) melamine compound and the like are used. Furthermore, as long as the effects of the present invention are not impaired,
It is also possible to add auxiliary agents such as the above-mentioned tackifier resin, softener, various pigments, viscosity modifier and the like.

As the substrate which can be used in the present invention, in addition to paper, non-woven fabric and plastic film, a sheet or tape such as metal foil or plastic or rubber foam can be used. Materials include polyvinyl chloride, polyethylene terephthalate,
Transparent base materials such as polypropylene and polyethylene are mentioned, and among them, a soft polyvinyl chloride film is more preferably used. In the case of a transparent substrate, the constitution of the present invention also prevents yellowing of the pressure-sensitive adhesive sheet.

As a method for processing the pressure-sensitive adhesive of the present invention into the above-mentioned base material, each component is stirred and dissolved in a solvent such as toluene, ethyl acetate, or a mixed solution of toluene and n-hexane, and the solid content is reduced to 10%. Prepared as ~ 70% by weight adhesive liquid. In the case of a single-sided pressure-sensitive adhesive tape, the pressure-sensitive adhesive composition thus prepared is applied to a dry thickness of 0.01 to 0.2 mm on the surface of the base material subjected to the release treatment on the back surface, and is wound after drying. It is manufactured by In the case of a double-sided pressure-sensitive adhesive tape, the pressure-sensitive adhesive composition is dried on the release layer surface of the release sheet at a dry thickness of 0.01 to
After applying to a thickness of 0.2 mm and drying, the adhesive is transferred to both the front and back surfaces of the substrate by a conventional method to produce. In the case of a pressure-sensitive adhesive sheet, the pressure-sensitive adhesive composition is applied to a dry thickness of 0.01 to 0.1 mm on the release layer surface of the release sheet, and after drying, is laminated and wound on a substrate without a release treatment. To manufacture.

[0028]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but it is needless to say that the present invention is not limited to these Examples. “Parts” and “%” in the following Examples and Comparative Examples represent “parts by weight” and “% by weight” unless otherwise specified.

A graph containing an ultraviolet absorbing monomer unit
Synthetic example of ft copolymer Production Example 1 UV-absorbing monomer 2- (hydroxy-5-methacryloyloxyphenyl) -2H-benzotriazole 6
0 parts, 40 parts of styrene, and mercaptoethanol 1
Was dissolved in 100 parts of ethyl acetate to prepare a monomer mixture. Dissolve 0.2 parts of azobisisobutylnitrile in 200 parts of ethyl acetate, heat to 75 ° C., stir and reflux.
The above monomer mixed solution was gradually added over 2 hours, and O
An oligomer containing an ultraviolet absorber having an H group was obtained. Furthermore, after adding 2.3 parts of tolylene diisocyanate and reacting for 3 hours, 1.8 parts of 2-hydroxyethyl methacrylate was added and reacted for 2 hours to obtain an ultraviolet absorbing macromer. 30 parts of the UV-absorbing macromer synthesized above and 70 parts of methyl methacrylate were dissolved in 100 parts of ethyl acetate to prepare a mixed solution. Separately, 0.2 part of azobisisobutylnitrile is dissolved in 200 parts of ethyl acetate, and the mixture is heated to 75 ° C., stirred and refluxed, and gradually added to the mixture over 3 hours. Was obtained.

Production Example 2 50 parts of methyl methacrylate and 2 parts of mercaptoacetic acid were dissolved in 50 parts of ethyl acetate to prepare a monomer mixed solution.
Separately, 0.1 part of benzoyl peroxide was dissolved in 200 parts of ethyl acetate, and the above-mentioned monomer mixed solution was gradually added thereto under heating, stirring and refluxing at 65 ° C over 2 hours, and 3.1 parts of glycidyl methacrylate was further added. Was added to obtain methyl methacrylate macromer. Next, 40 parts of the synthesized methyl methacrylate macromer, 40 parts of an ultraviolet absorbing monomer 2-hydroxy-4-acryloyloxybenzophenone, 30 parts of acrylonitrile, and 30 parts of methyl methacrylate were dissolved in 100 parts of ethyl acetate and mixed. A solution was prepared. Separately, 0.2 parts of benzoyl peroxide was added to 200 parts of ethyl acetate.
2 parts were dissolved, and the above mixed solution was gradually added thereto under heating, stirring and refluxing at 65 ° C. over 2 hours to obtain a graft copolymer containing an ultraviolet absorbing monomer unit in the main chain.

Production Example 3 UV-absorbing macromer 15 obtained in the same manner as in Production Example 1.
Part, 2-ethylhexyl acrylate 35 parts, butyl acrylate 35 parts, methyl methacrylate 14 parts,
One part of 2-hydroxyethyl methacrylate was dissolved in 100 parts of ethyl acetate to prepare a mixed solution. Separately, 0.3 parts of benzoyl peroxide was dissolved in 200 parts of ethyl acetate,
The mixed solution was gradually added over 2 hours under heating, stirring and refluxing at 5 ° C. to obtain an adhesive graft copolymer containing an ultraviolet absorbing monomer unit in a side chain.

Examples of the pressure-sensitive adhesive film produced using the above-mentioned graft copolymer containing an ultraviolet absorber are shown below. Example of Production of Adhesive Film Example 1 Acrylic solvent-type adhesive (trademark: BPS) as an adhesive main agent
-5626, manufactured by Toyo Ink Mfg. Co., Ltd., solid content concentration 45
%) And an isocyanate-based crosslinking agent (trademark:
1.8 parts of BXX-5627 (manufactured by Toyo Ink Mfg. Co., Ltd., solid content concentration: 50%), and the ultraviolet-absorbing graft copolymer solution obtained in Production Example 1 (solid content concentration: 19.0%)
50 parts was added to prepare a pressure-sensitive adhesive coating solution, which was coated on a release paper using an applicator to a dry thickness of 0.02 mm, dried, and then coated with a pressure-sensitive adhesive layer having a thickness of 0.07 mm.
It was laminated with a transparent soft polyvinyl chloride film having a thickness, and an adhesive layer was formed on this film to obtain a film adhesive sheet.

Example 2 65 parts of 2-ethylhexyl acrylate, 35 parts of butyl acrylate, and 3 parts of 2-hydroxyethyl methacrylate were dissolved in 200 parts of a mixed solvent of toluene / ethyl acetate = 1/1, and a polymerization initiator was further added. Azobisisobutylnitrile was added and polymerized to obtain a main adhesive. 100 parts of this pressure-sensitive adhesive base material (solid content, 34%) is mixed with an isocyanate-based crosslinking agent (trade name: Coronate L, manufactured by Nippon Polyurethane Co., Ltd., solid content concentration, 75%).
And 50 parts of the UV-absorbing graft copolymer solution (solid content, 21.9%) obtained in Production Example 2 were added to prepare an adhesive coating solution, and a dry thickness of 0.02 mm was formed on a release paper.
After applying and drying using an applicator so as to obtain a film, a pressure-sensitive adhesive sheet is formed by laminating a 0.07 mm-thick soft polyvinyl chloride film on the surface of the formed pressure-sensitive adhesive layer, forming a pressure-sensitive adhesive layer on the film. I got

Example 3 An isocyanate crosslinking agent (trade name: Coronate L, manufactured by Nippon Polyurethane Co., Ltd.) was added to 300 parts of the adhesive UV-absorbing graft copolymer solution (solid content, 22%) obtained in Production Example 3. , Solid content concentration, 75%) to prepare a pressure-sensitive adhesive coating solution by adding 1 part thereof, apply it on a release paper using an applicator so as to have a dry thickness of 25 μm, dry, and then apply 50 μm to the formed pressure-sensitive adhesive layer surface And a pressure-sensitive adhesive layer was formed on the film to obtain a film pressure-sensitive adhesive sheet.

Comparative Example 1 In preparing the adhesive coating solution, a benzotriazole-based UV absorber (trade name: Seesorb 709, manufactured by Cipro Kasei Co., Ltd.) was used instead of the UV-absorbing graft copolymer solution obtained in Production Example 1. ) A film adhesive sheet was obtained in the same manner as in Example 1 except that 5 parts were dissolved in 10 parts of toluene.

Comparative Example 2 Example 1 was repeated except that the UV-absorbing graft copolymer solution obtained in Production Example 1 was omitted in the preparation of the adhesive coating solution.
A film adhesive sheet was obtained in the same manner as described above.

Evaluation The release sheet of the film adhesive sheet obtained in each of Examples 1 to 3 and Comparative Examples 1 and 2 was removed, the film was adhered to a glass plate, and UV irradiation was performed from the film side with a sunshine weather meter for 300 hours. The degree of yellowing of the subsequent sample, the presence or absence of contamination on the surface of the glass plate as an adherend, and the presence or absence of a decrease in adhesive strength were evaluated as follows, and the results are shown in Table 1. (1) The yellowing of the film adhesive sheet was visually evaluated according to the following criteria. ：: No yellowing of the sample. Δ: The sample has some yellowing. ×: The sample is significantly yellowed. (2) The contamination of the glass plate surface (the adherend) was visually evaluated according to the following criteria. ：: No contamination on the glass plate surface. Δ: Slight contamination on the glass plate surface. ×: The contamination of the glass plate surface is remarkable. (3) The adhesive strength of the adhesive layer of the film adhesive sheet is JI.
The adhesive strength was measured based on SZ2037, and the decrease in adhesive strength before and after UV irradiation was evaluated according to the following criteria. Δ: There is a slight decrease in adhesive strength. X: The adhesive strength is significantly reduced. In the above evaluation criteria, the ○ level is suitable for practical use, but the 以下 level or less is not suitable for practical use.

[0038]

[Table 1]

[0039]

Industrial Applicability According to the present invention, it is possible to practically use an adhesive tape or sheet which is excellent in light resistance, has no contamination of adherends, has excellent plasticizer resistance and hardly decreases in adhesive strength. It greatly contributes to

Claims (2)

[Claims] 1. A pressure-sensitive adhesive tape or sheet having a pressure-sensitive adhesive layer having a rubber and / or acrylate-based copolymer as a main component on one surface of a substrate, wherein the pressure-sensitive adhesive layer comprises: A UV-absorbing graft copolymer obtained by graft-polymerizing a vinyl compound copolymerizable with the macromer to a macromer having a monomer unit, and / or (b) at least a UV-absorbing monomer;
A pressure-sensitive adhesive tape or sheet comprising an ultraviolet-absorbing graft copolymer obtained by graft-polymerizing a macromer. 2. A pressure-sensitive adhesive tape or sheet in which a pressure-sensitive adhesive layer is formed on one surface of a substrate, wherein the pressure-sensitive adhesive layer has at least 2-ethylhexyl acrylate or (c) a macromer having a UV-absorbing monomer unit as a main component. Adhesive UV-absorbing graft copolymer obtained by graft-polymerizing butyl acrylate, and / or (d) Adhesive UV-ray obtained by graft-polymerizing a UV-absorbing monomer and at least 2-ethylhexyl acrylate or butyl acrylate to a macromer A pressure-sensitive adhesive tape or sheet comprising an absorption graft copolymer.