JPH10204392A - Self-adhesive sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a self-adhesive sheet that makes the self-adhesive layer formable without requiring a complicated process and that is excellent in cuttability, self-adhesive properties, stickability, etc. SOLUTION: This self-adhesive sheet comprises a synthetic resin film, a self-adhesive layer formed on one side thereof, and a release paper stuck to the surface thereof with a peeling strength of 40-200g/50mm-width. The self-adhesive layer is formed from an acrylic copolymer produced from 60-95wt.% (4-14C)- alkyl (meth)acrylate and 5-40wt.% vinyl acetate and having a wt. average mol.wt. of 200,000-600,000 and has been cross-linked so that its gel fraction is 40-65wt.%.

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 using an acrylic pressure-sensitive adhesive, and more particularly, to a pressure-sensitive adhesive sheet formed by laminating an acrylic pressure-sensitive adhesive and release paper on a synthetic resin film substrate. The present invention relates to an adhesive sheet cut into a shape and used for decoration and marking.

[0002]

2. Description of the Related Art Conventionally, an adhesive sheet has been used for decorating or marking indoors and outdoors. This type of pressure-sensitive adhesive sheet has a structure in which a release paper is laminated on a pressure-sensitive adhesive film in which an acrylic pressure-sensitive adhesive layer is formed on one surface of a film substrate so as to cover the pressure-sensitive adhesive layer.

With respect to the acrylic pressure-sensitive adhesive, various studies have been made on the monomer composition, molecular weight, and the like in order to enhance durability and the like. In addition, the pressure-sensitive adhesive sheet used for decoration and marking is required to have not only sufficient adhesiveness to various adherends but also appropriate cutting properties. That is, in the pressure-sensitive adhesive sheet used for decoration and marking, in a state where the release paper is laminated, cut into various shapes using a cutting machine, a punching machine, or a cutter, and then,
Often affixed to adherends. Therefore, there is a strong demand that even when cutting is performed by such various cutting methods, it is easy to cut into a desired shape, and it is difficult for the adhesive to protrude.

Japanese Patent Application Laid-Open No. 4-173890 discloses a pressure-sensitive adhesive which has good cutting properties as described above, and in which the pressure-sensitive adhesive does not easily protrude, and a pressure-sensitive adhesive member using the pressure-sensitive adhesive. Have been. Here, a pressure-sensitive adhesive containing, as a main component, an acrylic acid-based alkyl ester having 4 to 18 carbon atoms in an alkyl group and containing polymer particles cross-linked within the particles is disclosed, and the acrylic cross-linked acrylic particles within the particles are disclosed. It is said that the polymer particles exhibit good cut properties and easy transfer properties.

[0005]

However, in the pressure-sensitive adhesive and the pressure-sensitive adhesive member described in the above prior art, when the acrylic polymer particles crosslinked in the particles are contained,
A complicated process is required. That is, it is necessary to carry out complicated steps such as a method of pulverizing the crosslinked acrylic polymer or a method of polymerizing in a medium to obtain a dispersion of the polymer, and the manufacturing process of the adhesive is complicated. There was a problem.

An object of the present invention is to solve the above-mentioned disadvantages of the prior art, and to provide a pressure-sensitive adhesive sheet which can be produced without performing complicated steps such as blending various components and which can exhibit good cutting performance. To provide.

[0007]

Means for Solving the Problems The present invention has been made to achieve the above-mentioned object, and the pressure-sensitive adhesive sheet according to the present invention has an alkyl group having 4 to 4 carbon atoms on one surface of a synthetic resin film. 14 alkyl (meth) acrylates 60-
Acrylic pressure-sensitive adhesive composed of an acrylic copolymer having a weight average molecular weight of 200,000 to 600,000 and consisting of 95% by weight and 5 to 40% by weight of vinyl acetate and having a gel fraction of 40 to 65% by weight A pressure-sensitive adhesive film on which a layer is laminated; and a release paper laminated on the surface of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive film such that a peeling force from the pressure-sensitive adhesive film is 40 to 200 g / 50 mm in width. .

Hereinafter, the present invention will be described in detail. For the synthetic resin film that can be used in the present invention, it is possible to use a suitable synthetic resin film base conventionally used for decorative sheets, marking films, and the like,
There is no particular limitation. Examples of such synthetic resin films include films made of soft polyvinyl chloride, urethane-based resin, acrylic resin, and the like.

Further, an ultraviolet absorber, a plasticizer, a heat stabilizer and the like may be added to the synthetic resin film in order to improve various performances. The ultraviolet absorber can be added to enhance the weather resistance, and the ultraviolet absorber that can be used is not particularly limited. For example, a known ultraviolet light such as a benzophenone-based, benzotriazole-based, or cyanoacrylate-based ultraviolet absorber can be used. An absorbent can be used.

[0010] The plasticizer is also added to enhance the flexibility of the synthetic resin film, but is not particularly limited. For example, a known plasticizer such as a polyester plasticizer can be used. .

The heat stabilizer is used to enhance the heat resistance of the pressure-sensitive adhesive sheet according to the present invention, and the type of the heat stabilizer is not particularly limited. Known heat stabilizers such as Ba-Zn type can be used.

Although the thickness of the synthetic resin film 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 film is too thin, it will lose its stiffness and the workability when used as a decorative sheet or a marking film may be reduced. If it is too thick, it is attached to an adherend having a three-dimensional curved surface. Followability may be reduced.

The synthetic resin film is often colored when used as a decorative sheet or a marking film, and therefore may contain an appropriate pigment or dye. The pigments and dyes that can be used are not particularly limited, but, for example, quinacridone red pigments, titanium oxide pigments, cyanine blue pigments, and the like can be used.

In the pressure-sensitive adhesive sheet according to the present invention, the specific acrylic pressure-sensitive adhesive layer is laminated on one surface of the synthetic resin film. The acrylic pressure-sensitive adhesive layer is formed of the specific acrylic copolymer. It is only crosslinked so as to be in the specific gel fraction range described above, without going through the step of blending or dispersing various components such as the acrylic pressure-sensitive adhesive described in the prior art described above. Obtainable.

Examples of the alkyl (meth) acrylate having an alkyl group having 4 to 14 carbon atoms include butyl acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, and isooctyl ( Meth) acrylate, n-
Nonyl (meth) acrylate, isononyl (meth) acrylate, lauryl (meth) acrylate, myristyl (meth) acrylate, etc., may be used alone or in combination of two or more. 2
When more than one kind of alkyl (meth) acrylate is used, the total is copolymerized at a ratio of 60 to 95% by weight as described above.

If the alkyl group has less than 4 carbon atoms, the glass transition temperature becomes high, making it difficult to obtain an initial adhesive strength. If it exceeds 15, the copolymerizability decreases. In the acrylic copolymer, the alkyl (meth) acrylate and vinyl acetate are copolymerized so as to contain 60 to 95% by weight of the alkyl (meth) acrylate and 5 to 40% by weight of vinyl acetate.

If the amount of vinyl acetate is less than 5% by weight, the cutting properties are not sufficient, and if it exceeds 40% by weight, the adhesive performance of the acrylic pressure-sensitive adhesive decreases.

The above-mentioned acrylic copolymer may be copolymerized with another vinyl monomer other than the above-mentioned alkyl (meth) acrylate and vinyl acetate. For example, (meth) acrylic acid, itaconic acid, crotonic acid, ( Anhydride) maleic acid, fumaric acid, carboxyl group-containing vinyl monomers such as carboxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, modified caprolactone (meth) acrylate, polyethylene glycol ( Hydroxyl-containing vinyl monomers such as (meth) acrylate and polypropylene glycol (meth) acrylate, (meth) acrylonitrile, N-vinylpyrrolidone, N-vinylcaprolactam, N-vinyllaurylolactam, (meth) acryloylmorpholine, ) Acrylamide, dimethyl (meth) acrylamide, N- methylol (meth) acrylamide, N- butoxymethyl (meth) acrylamide,
Nitrogen-containing vinyl monomers such as dimethylaminopropyl (meth) acrylamide, dimethylaminomethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, diethylaminoethyl (meth) acrylate, vinyl propionate, and styrene , Isobornyl (meth) acrylate and the like, which may be used alone or in combination of two or more.

The copolymerization ratio of the other vinyl monomers is as follows:
When the amount is increased, the glass transition temperature becomes high and it becomes difficult to obtain initial adhesiveness. Therefore, the amount is preferably 20 parts by weight or less based on 100 parts by weight of the total amount of the alkyl (meth) acrylate and vinyl acetate.

If the weight average molecular weight of the acrylic copolymer is too small, the cohesive force of the acrylic pressure-sensitive adhesive itself will not be sufficiently large, and if it is too large, the cutting properties will be reduced. Therefore, the weight average molecular weight of the acrylic copolymer is in the range of 200,000 to 600,000, and more preferably in the range of 250,000 to 450,000.

The acrylic copolymer is crosslinked so as to have a gel fraction of 40 to 65% by weight. Regarding a crosslinking agent that can be used, an appropriate crosslinking agent capable of crosslinking the acrylic copolymer is used. For example, an isocyanate-based crosslinking agent, an epoxy-based crosslinking agent, or the like can be used. About the compounding ratio of the cross-linking agent, the gel fraction is determined so as to be within the above specific range, and this compounding ratio cannot be uniquely determined because it differs depending on the type of the acrylic copolymer or the cross-linking agent. .

When the gel fraction is less than 40% by weight, the cohesive strength of the acrylic pressure-sensitive adhesive itself is hardly obtained, and when it exceeds 65% by weight, the initial adhesive strength is hardly obtained. Therefore, it is necessary that the crosslinking is performed so that the gel fraction is 40 to 65% by weight.

With respect to the thickness of the acrylic pressure-sensitive adhesive layer, if the thickness is too small, the adhesive strength and holding power may be insufficient, and if the thickness is too large, the pressure-sensitive adhesive may easily overflow. Accordingly, the thickness of the acrylic pressure-sensitive adhesive varies depending on the composition of the acrylic pressure-sensitive adhesive, but usually ranges from 15 to 70.
It is preferable that the thickness be about μm.

The method of laminating the acrylic pressure-sensitive adhesive layer on one surface of the synthetic resin film is not particularly limited, and an acrylic pressure-sensitive adhesive solution is applied to one surface of the synthetic resin film using an appropriate coating machine and dried. Can be used.

As the release paper to be laminated on the surface of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive film, an appropriate release paper agent conventionally used for a pressure-sensitive adhesive sheet for this kind of application, for example, high-quality paper, glassine paper or the like can be used. . However, release paper is
Peeling force with the adhesive film is 40 to 200 g / 50 m
It is necessary that the peeling force be adjusted so as to have an m width. If the release force of the release paper is less than 40 g, the cutting property is reduced, and if it exceeds 200 g / 50 mm width, the transfer property to the application sheet is deteriorated.

In order to adjust the release force of the release paper as described above, the surface of the release paper is usually coated with a release agent,
Release processing is performed by aging. The type of the release agent is not particularly limited, but examples thereof include a release agent containing a silicone resin and a release force control agent. Specifically, addition of a low-molecular-weight dimethylsiloxane to a silicone resin as a release force control agent may be mentioned. The release force can be adjusted by adjusting the type of the release agent and the aging conditions after the release agent is applied.

If the release paper is too thin, it may be difficult to handle the entire sheet, and if it is too thick, the workability when peeling the release paper may be reduced. Therefore, the release paper usually has a thickness of 80 to 300 μm, preferably 1 to 300 μm.
It is set to 00 to 200 μm.

[0028] In such a pressure-sensitive adhesive sheet to effect the present invention, such as the above-mentioned specific alkyl (meth) acrylate and a vinyl acetate made by copolymerizing at a rate specified above acrylic copolymer the specific gel fraction An acrylic pressure-sensitive adhesive layer is formed using an acrylic pressure-sensitive adhesive that is cross-linked. That is, the acrylic pressure-sensitive adhesive layer is constituted only by cross-linking the acrylic copolymer, and because the specific cross-linked acrylic copolymer is used, as will be apparent from the examples described later. Not only can exhibit sufficient adhesive performance, but also have good cutting properties. In addition, since the acrylic pressure-sensitive adhesive layer is composed of the crosslinked acrylic copolymer, the pressure-sensitive adhesive layer can be formed without obtaining a complicated manufacturing process.

Further, since the release force of the release paper falls within the above-mentioned specific range, cutting properties are good and transferability to an application sheet is good.

That is, the pressure-sensitive adhesive sheet according to the present invention comprises:
By composing the acrylic pressure-sensitive adhesive layer using the specific cross-linked acrylic copolymer that is easy to produce, while eliminating the complexity of the manufacturing process, and exhibiting the desired adhesive performance and cutting performance, By controlling the release force of the release paper within the above-mentioned specific range, cutting characteristics and transfer performance are improved.

[0031]

The present invention will be clarified below by describing non-limiting examples of the present invention.

Example 1 An acrylic copolymer reactor was charged with 100 parts by weight of a main monomer mixture composed of 22.3% by weight of vinyl acetate, 55.7% by weight of butyl acrylate, and 22% by weight of 2-ethylhexyl acrylate. 11.1 parts by weight of acrylic acid, 0.33 parts by weight of hydroxyethyl methacrylate, 100 parts by weight of ethyl acetate and 0.002 parts by weight of dodecyl mercaptan were added, and 3 parts by weight were added.
Bubbling was performed with nitrogen gas for 0 minutes to substantially remove dissolved oxygen. Next, the mixture was heated to 80 ° C. under a nitrogen atmosphere, charged with 0.03 parts by weight of azobisisobutyronitrile, reacted for 7 hours, and diluted with toluene after completion of the reaction to obtain a solid content of 35% by weight. An acrylic copolymer solution was obtained.

When the molecular weight of the acrylic copolymer solution was measured by gel permeation chromatography, the weight average molecular weight was 450,000, and the ratio Mw / Mn of the weight average molecular weight to the number average molecular weight was 4.5. there were.

Colored flexible polyvinyl chloride film Vinyl chloride resin (manufactured by Kanegafuchi Chemical Co., Ltd., product number: PSH-10)
100 parts by weight, 30 parts by weight of polyester plasticizer (manufactured by Asahi Denka, part number: P-300), 5 parts by weight of metal stabilizer (manufactured by Asahi Denka, part number: MARKAR-551), ultraviolet absorber (manufactured by Asahi Denka) , Part number: MARK1413) 1 part by weight, solvent (manufactured by Mitsubishi Yuka Co., trade name: Solvesso) 60 parts by weight, titanium oxide pigment (manufactured by Dainichi Seika, part number: VT-7)
71) A colored PVC organosol prepared by mixing 40 parts by weight was prepared, coated on a process paper to a thickness of 60 μm, and cured to obtain a colored flexible polyvinyl chloride film.

The above-mentioned acrylic copolymer and isocyanate-based crosslinking agent (manufactured by Nippon Polyurethane Co., Ltd., product number: L) are coated on the surface of the colored flexible polyvinyl chloride film obtained as described above.
-28) with a solid content ratio of 100: 1.5 (weight ratio), and then applied so that the thickness after drying becomes 30 μm to form an acrylic pressure-sensitive adhesive layer. A release paper of high quality paper, the surface of which was release-treated with a silicone resin and a dimethylsiloxane low molecular weight material and whose release force was adjusted, was laminated to obtain a marking film. The pressure-sensitive adhesive layer containing the acrylic pressure-sensitive adhesive and the isocyanate-based curing agent had a gel fraction of 55% by weight, and the release force of the release paper was 70 g / 50 mm width.

Example 2 The monomer composition for obtaining the acrylic copolymer was a main monomer consisting of 17.7% by weight of vinyl acetate, 58.8% by weight of butyl acrylate and 23.5% by weight of 2-ethylhexyl acrylate. Except that 17.3 parts by weight of acrylic acid and 0.35 parts by weight of hydroxyethyl methacrylate were added to 100 parts by weight of the mixture, a weight average molecular weight of 550,000 and Mw / Mn = 3 were obtained in the same manner as in Example 1. Acrylic copolymer of 0.8 was obtained.

A marking film was prepared in the same manner as in Example 1 except that the above acrylic copolymer was used. The acrylic adhesive layer containing the crosslinking agent had a gel fraction of 50% by weight, and the release force of the release paper was 90 g /.
The width was 50 mm.

Example 3 11.1% by weight of vinyl acetate
As in Example 1, except that acrylic acid 11.1 parts by weight was added to 100 parts by weight of the main monomer mixture consisting of 55.6% by weight of butyl acrylate and 33.3% by weight of 2-ethylhexyl acrylate. An acrylic copolymer having a weight average molecular weight of 550,000 and Mw / Mn = 3.8 was obtained.

Also, the above-mentioned acrylic copolymer and isocyanate-based crosslinking agent (manufactured by Nippon Polyurethane Co., Ltd., product number: L-2) were added to the colored flexible polyvinyl chloride film prepared in Example 1.
8) was applied at a solid content ratio of 100: 4.5 to form a mixed solution having a thickness after drying of 30 μm, and release paper was laminated in the same manner as in Example 1. A marking film was obtained. The gel fraction of the acrylic pressure-sensitive adhesive layer is 55
% By weight, the release force of the release paper was 80 g / 50 mm width.

Example 4 The procedure of Example 1 was repeated except that the amount of dodecyl mercaptan was changed from 0.002 parts by weight to 0.004 parts by weight when obtaining the acrylic copolymer. A marking film was obtained. The weight average molecular weight of the acrylic pressure-sensitive adhesive obtained in Example 4 was 300,000 and Mw / Mn = 4.0, the gel fraction of the acrylic pressure-sensitive adhesive layer was 48% by weight, and the release force of the release paper was 110g / 5
The width was 0 mm.

(Comparative Example 1) The monomer composition was changed to 3.6% by weight of vinyl acetate, 72.3% by weight of butyl acrylate,
100 parts by weight of a main monomer mixture consisting of 24.1% by weight of ethylhexyl acrylate,
1 part by weight and hydroxyethyl methacrylate 0.36
An acrylic copolymer having a weight-average molecular weight of 500,000 and Mw / Mn = 4.1 was obtained in the same manner as in Example 1 except that part by weight was added. A marking film was obtained in the same manner as in Example 1 except that the acrylic copolymer was used. The gel fraction of the acrylic pressure-sensitive adhesive layer was 53% by weight, and the release force of the release paper was 95 g / 50 m.
m width.

Comparative Example 2 The monomer composition was 45.9% by weight of vinyl acetate, 30.6% by weight of butyl acrylate,
To 100 parts by weight of the main monomer mixture consisting of 23.5% by weight of 2-ethylhexyl acrylate, 1 part of acrylic acid was added.
73 parts by weight and hydroxyethyl methacrylate 0.3
An acrylic copolymer having a weight average molecular weight of 530,000 and Mw / Mn = 4.1 was obtained in the same manner as in Example 1, except that the amount was changed to parts by weight. A marking film was obtained in the same manner as in Example 1 except that the acrylic pressure-sensitive adhesive was used. The gel fraction of the acrylic pressure-sensitive adhesive layer was 4
7% by weight, the release force of the release paper was 83 g / 50 mm width.

Comparative Example 3 Example 1 was repeated except that the amount of dodecyl mercaptan was changed from 0.002 parts by weight to 0.01 parts by weight when obtaining an acrylic copolymer.
A marking film was obtained in the same manner as described above. The weight average molecular weight of the acrylic copolymer was 180,000, and Mw / Mn =
The gel fraction of the acrylic pressure-sensitive adhesive layer was 49% by weight, and the release force of the release paper was 105 g / 50 mm width.

Comparative Example 4 A marking film was prepared in the same manner as in Example 1 except that the amount of dodecyl mercaptan was changed from 0.002 parts by weight to no addition when obtaining an acrylic copolymer. Obtained. The weight average molecular weight of the acrylic copolymer was 880,000, Mw / Mn = 4.5, the gel fraction of the acrylic pressure-sensitive adhesive layer was 61% by weight, and the release force of the release paper was 82 g / 50 mm width. there were.

Comparative Example 5 A marking film was obtained in the same manner as in Example 1 except that the acrylic copolymer and the isocyanate-based crosslinking agent were mixed at a solid content ratio of 100: 5. . The weight average molecular weight of the acrylic copolymer is 450,000, Mw / Mn = 4.5, the gel fraction of the acrylic pressure-sensitive adhesive layer is 68% by weight, and the release force of the release paper is 75 g / 50 mm width. there were.

Comparative Example 6 An acrylic copolymer and an isocyanate-based cross-linking agent were mixed at a solid content ratio of 100: 0.5, and then applied with a dry thickness of 30 μm, and a release paper was laminated. Then, a marking film was obtained in the same manner as in Example 1. The weight average molecular weight of the acrylic copolymer is 450,000, Mw / Mn = 4.5, the gel fraction of the acrylic pressure-sensitive adhesive layer is 33% by weight, and the release force of the release paper is 88 g / 50 mm width. there were.

(Comparative Example 7) The release force of the release paper was set to 20 g / 5.
A marking film was obtained in the same manner as in Example 1 except that the release paper was changed to have a width of 0 mm.

Comparative Example 8 The release force of the release paper was 250 g /
A marking film was obtained in the same manner as in Example 1, except that the release paper was changed to have a width of 50 mm.

(Evaluation of Examples and Comparative Examples) Each of the marking films obtained in Examples and Comparative Examples was evaluated for cutability, adhesive property, cohesion and application tape transferability in the following manner. .

Evaluation of cutability: The marking film was cut in half from the surface opposite to the release paper, that is, from the colored soft polyvinyl chloride film side to the adhesive layer, and
After being left for 0 minutes, the state of stringing of the pressure-sensitive adhesive layer when the release paper was peeled was visually evaluated on a 5-point scale. The evaluation criteria are as follows.

5: No stringing of the pressure-sensitive adhesive is observed at all. 4: Stringing occurred at a very small part of the adhesive (less than 5%). 3: Threading occurred in part of the adhesive (5 to 20%). 2: Stringiness was observed in the adhesive (20 to 50%). 1: The stringing of the pressure-sensitive adhesive was remarkable (50% or more).

Evaluation of Adhesive Properties: Marking film 2
After slitting to a width of 5 mm and peeling the release paper, it was pasted on a steel plate and pressed back and forth by a 2 kg roller from the back side. After 24 hours, the marking film was peeled at a rate of 300 mm / min in the direction of 180 °, The adhesive properties were evaluated by measuring the peel strength.

Evaluation of cohesion: Marking sheet 25 m
After slitting the release paper and pasting it on a steel plate, a 2 kg roller is reciprocated from the back side and pressed, and after 1 hour, the steel plate is leveled and the marking film is positioned on the lower surface. The marking film was rolled in the direction of 90 ° from the steel plate, a 200 g weight was hung, and the peeling length (mm) of the marking sheet after 3 hours had elapsed was measured.

Application tape transferability: A character having a size of 20 mm × 20 mm was cut out from the marking film and applied to an application tape (adhesive strength: 80 g / 2).
(5 mm), the transferred state was evaluated in three steps.
The evaluation criteria are as follows.

3: The transfer was successfully performed. 2: It took time to transfer. 1: Could not be transferred.

The results are shown in Table 1 below.

[0057]

[Table 1]

[0058]

According to the present invention, 60 to 95% by weight of the above-mentioned specific alkyl (meth) acrylate and 5 to 40% by weight of vinyl acetate are copolymerized, and the weight average molecular weight is 20%.
10,000 to 600,000 acrylic copolymers having a gel fraction of 40 to 6
Since the acrylic pressure-sensitive adhesive layer crosslinked to 5% by weight is used, the acrylic pressure-sensitive adhesive is excellent not only in adhesive strength and cohesive strength, but also can exhibit excellent adhesive physical properties. Since the layer and the release paper having a release force of 40 to 200 g / 50 mm width are laminated, the cutting performance is good, and the transfer performance when using an application tape or the like is also excellent. I have.

Specifically, when used as a decorative sheet or a marking film, it can be easily cut into a desired shape by various cutting methods, and in that case, the adhesive does not easily protrude. The adhesive sheet cut in the shape of the above can be easily and reliably stuck to various adherend surfaces.

In addition, since the above-mentioned acrylic pressure-sensitive adhesive layer is merely constituted by using the above-mentioned specific cross-linked acrylic copolymer, various components which are complicated in production may be blended, There is no need to perform complicated steps such as dispersing.

Claims (1)

[Claims] An alkyl (meth) acrylate having an alkyl group of 4 to 14 carbon atoms on one surface of a synthetic resin film.
Acrylic copolymer composed of an acrylic copolymer having a weight average molecular weight of 200,000 to 600,000 and comprising 0 to 95% by weight and 5 to 40% by weight of vinyl acetate, and having a gel fraction of 40 to 65% by weight. An adhesive film on which an adhesive layer is laminated, and a release paper laminated on the surface of the adhesive layer of the adhesive film such that a peeling force from the adhesive film is 40 to 200 g / 50 mm width. Adhesive sheet.