JP5299804B2 - Adhesive sheet for attaching metal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure-sensitive adhesive sheet for application to metals, a pressure-sensitive adhesive sheet for a deposited metal film, and a deposited metal film label which prevent the corrosion of a metallic layer and the foaming of a pressure-sensitive adhesive layer and enhance the cohesive force and adhesiveness of a pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer. <P>SOLUTION: The pressure-sensitive adhesive sheet for application to metals, the pressure-sensitive adhesive sheet for a deposited metal film, the deposited metal film label, a pressure-sensitive adhesive sheet for a touch panel, a touch panel member, and a touch panel have a pressure-sensitive adhesive layer obtained by crosslinking a pressure-sensitive adhesive composition comprising specific amounts of a specific acrylic copolymer (A) and benzotriazole and/or its derivative (B) with the use of an epoxy crosslinking agent (C) having a functional group Z capable of reacting with the carboxy group X in the above acrylic copolymer (A) in such an amount so as to render the ratio of X:Z (equivalent ratio) in a specific range. This pressure-sensitive adhesive layer excels in the balance of the anticorrosion of metals and the adhesion to metals, does not cause peeling, foaming of the pressure-sensitive adhesive layer and the like even over long-term use in a high temperature and humidity environment, and can effectively prevent the corrosion of a metallic layer such as a deposited metal layer and an electrode. <P>COPYRIGHT: (C)2006,JPO&amp;NCIPI

Description

  The present invention relates to an adhesive sheet, a metal vapor deposition film label, a touch panel member, and a touch panel. More specifically, the present invention relates to a metal sticking pressure-sensitive adhesive sheet, a metal vapor-deposited film pressure-sensitive adhesive sheet, a metal vapor-deposited film label, a touch panel pressure-sensitive adhesive sheet, a touch panel member, and a touch panel.

  Conventionally, sticking an adhesive sheet to a metal surface has been widely performed for metal protection and surface decoration. In the pressure-sensitive adhesive layer constituting the pressure-sensitive adhesive sheet, a triazole-based compound such as benzotriazole is added in anticipation of a metal corrosion prevention effect (see Patent Documents 1 and 2).

  For example, Patent Literature 1 discloses a pressure-sensitive adhesive tape for copper piping having a pressure-sensitive adhesive layer obtained by crosslinking a pressure-sensitive adhesive composition obtained by adding a triazole-based compound to an acrylic copolymer with an isocyanate-based crosslinking agent. However, in the pressure-sensitive adhesive tape, since the isocyanate-based crosslinking agent reacts with the triazole-based compound, the pressure-sensitive adhesive may not be sufficiently crosslinked and the cohesive force of the pressure-sensitive adhesive may be reduced.

  In Patent Document 2, a crosslinking agent and a triazole compound as a heavy metal deactivator are added to an acrylic copolymer comprising 80 to 99% by weight of an acrylic acid alkyl ester and 1 to 20% by weight of a hydroxyl group-containing monomer. A pressure-sensitive adhesive sheet for metal sticking having a pressure-sensitive adhesive layer is described. However, in the pressure-sensitive adhesive sheet, since the hydroxyl group-containing monomer reacts with the benzotriazole derivative, there is a risk that the cohesive force of the pressure-sensitive adhesive will be lowered without being sufficiently crosslinked, while a large amount is required for sufficient crosslinking. When a hydroxyl group-containing monomer is used, there is a problem that the adhesive strength is lowered and the pressure-sensitive adhesive sheet is easily peeled off from the adherend metal.

  Conventionally, metal vapor deposition films are used in various fields such as packaging materials and building materials because of their reflectivity and light shielding properties. In particular, a metal vapor-deposited film label in which a pressure-sensitive adhesive layer made of an acrylic copolymer is formed on the metal layer of the metal vapor-deposited film is convenient for handling and excellent in workability, and the pressure-sensitive adhesive layer itself has good transparency. Widely used.

  However, since the metal layer of the metal-deposited film is usually a metal such as Al, Cu, Ag or the like deposited with a thickness of about 500 mm, depending on the use conditions, particularly in a high temperature and high humidity environment, Due to corrosion and foaming of the pressure-sensitive adhesive layer, its reflectivity and light-shielding properties may be impaired.Furthermore, there are problems such as the occurrence of peeling due to a decrease in cohesive force due to insufficient crosslinking of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer, It has been difficult to use a metal-deposited film label in a stable state for a long time in a high-temperature and high-humidity environment.

  On the other hand, in order to prevent the corrosion of the metal layer of the metal vapor-deposited film in anticipation of the anti-corrosion effect of the triazole-based compound, it is possible to use an adhesive obtained by adding a triazole-based compound to an acrylic copolymer. It has been proposed (see Patent Documents 3 to 4).

For example, Patent Document 3 describes an aluminum vapor-deposited film label having a pressure-sensitive adhesive composition obtained by adding benzotriazole to an acrylic copolymer, and a pressure-sensitive adhesive layer obtained by crosslinking the pressure-sensitive adhesive composition with an isocyanate-based crosslinking agent. Yes. However, what is specifically described as the acrylic copolymer is obtained by copolymerizing a monomer mixture containing 7 parts by weight of a carboxyl group-containing monomer with respect to 93 parts by weight of an acrylic ester. Since the amount of the carboxyl group-containing monomer is relatively large, the effect of preventing corrosion of the metal layer is not sufficient, and since the isocyanate crosslinking agent reacts with benzotriazole, the pressure-sensitive adhesive is not sufficiently crosslinked. The cohesive strength of the agent may be reduced.

  Patent Document 4 discloses that benzotriazole-based metal corrosion prevention is carried out on an acrylic polymer obtained by copolymerizing a monomer mixture containing (meth) acrylic acid alkyl ester as a main component and a carboxyl group-containing monomer in an amount of 3 to 20% by weight. An acrylic pressure-sensitive adhesive layer formed by adding a functional group-containing compound having a functional group that reacts with the carboxyl group of the acrylic polymer so that the equivalent ratio is 0.8 or more. A releasable pressure-sensitive adhesive tape is disclosed. However, the releasable pressure-sensitive adhesive tape is intended to protect the surface of the adherend during the etching process, and is premised on being used for temporary adhesion that is peeled off immediately after completion of etching. It is difficult to say that the cohesive strength and adhesive strength of the adhesive are sufficient.

  Also in the field of so-called touch panels, the electrodes and routing circuits provided on the upper electrode plate and the lower electrode plate are made of a metal layer containing a corrosive metal such as Ag. Adhesion and bonding with the opposite electrode plate via an insulating layer such as an adhesive layer, so that corrosion of the metal layer due to the adhesive, peeling due to adhesive cohesive strength or insufficient adhesive strength is a problem It had been.

For example, Comparative Example 3 of Patent Document 4 includes 100 parts by weight of n-butyl acrylate, 7 parts by weight of acrylic acid, 1 part by weight of a plasticizer, 3 parts by weight of a benzotriazole-based metal corrosion inhibitor, an epoxy-based crosslinking agent (tetraglycidyl). An example of an adhesive tape using xylenediamine) is shown, and the equivalent ratio of polyfunctional compound to carboxyl group in this adhesive tape is 0.5. By using this pressure-sensitive adhesive tape, it is described that there is a certain effect regarding the occurrence of metal corrosion, but according to the study by the present inventors, when such a pressure-sensitive adhesive tape is used for a touch panel, for example, The balance between corrosion resistance and adhesion to metals, especially Ag, is poor, the upper and lower electrode plates cannot be firmly bonded, and when used under harsh conditions for a long time, they may corrode from the bonded portion of the Ag electrode. I found out.
JP-A-5-163473 Japanese Unexamined Patent Publication No. 01-256582 Japanese Patent Application Laid-Open No. 07-242863 JP 2001-19915 A

An object of the present invention is to provide a pressure-sensitive adhesive sheet for attaching metal , which prevents corrosion of the metal layer and foaming of the pressure-sensitive adhesive layer, and increases the cohesive force and pressure-sensitive adhesive force of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer. Yes.

Furthermore, the present invention prevents adhesion of a metal layer such as an electrode and a routing circuit, and also has a pressure-sensitive adhesive layer having a pressure-sensitive adhesive layer having an increased cohesive force and pressure-sensitive adhesive, and can be suitably used for a touch panel. It also aims to provide a seat .

The adhesive sheet for attaching metal according to the present invention is
Acrylic copolymer having an alkyl (meth) acrylate as a main monomer component, a carboxyl group-containing monomer being copolymerized in an amount of 1% by weight or more and less than 3% by weight, and substantially free of a hydroxyl group-containing monomer. Benzotriazole, 4-methylbenzotriazole, 5-methylbenzotriazole, 5-chlorobenzotriazole, tolyltriazole, tolyltriazole K salt and 3- (N-salicyloyl) amino-to 100 parts by weight of compound (A) An adhesive composition comprising at least one benzotriazole (B) selected from the group consisting of 1,2,4-triazole in an amount of 1 to 10 parts by weight;
An epoxy crosslinking agent (C) having a functional group Z capable of reacting with the carboxyl group X in the acrylic copolymer (A),
The equivalent ratio (X: Z) of the functional group Z in the epoxy crosslinking agent (C) to the carboxyl group X in the acrylic copolymer (A) is 1: 0.01 to 1: 0.4. A small amount of carboxyl groups remain in the acrylic copolymer after the crosslinking reaction without using up all the carboxyl groups X in the crosslinking reaction with the epoxy crosslinking agent (C). A small amount of the carboxyl group is dissociated into H ⁺ and —COO ⁻ — in a moist heat environment, and the remaining small amount of H ⁺ is stabilized by benzotriazole and / or its derivative (B). Is formed on at least one side of the support.

In the metal sticking pressure-sensitive adhesive sheet, the pressure-sensitive adhesive layer may be formed on both surfaces of the support.
The pressure-sensitive adhesive sheet for metal vapor deposition film according to the present invention is
Acrylic copolymer having an alkyl (meth) acrylate as a main monomer component, a carboxyl group-containing monomer being copolymerized in an amount of 1% by weight or more and less than 3% by weight, and substantially free of a hydroxyl group-containing monomer. A pressure-sensitive adhesive composition comprising benzotriazole and / or its derivative (B) in an amount of 1 to 10 parts by weight with respect to 100 parts by weight of the union (A);
An epoxy crosslinking agent (C) having a functional group Z capable of reacting with the carboxyl group X in the acrylic copolymer (A),
The equivalent ratio (X: Z) of the functional group Z in the epoxy crosslinking agent (C) to the carboxyl group X in the acrylic copolymer (A) is 1: 0.01 to 1: 0.4. The pressure-sensitive adhesive layer obtained by crosslinking in an appropriate amount is formed on at least one side of the support.

  In the pressure-sensitive adhesive sheet for metal vapor-deposited film, (1) the pressure-sensitive adhesive layer may be formed on one side of the support and the support may be a release material, or (2) the pressure-sensitive adhesive layer. May be formed on both sides of the support.

  Moreover, the metal vapor deposition film label which concerns on this invention is the adhesive sheet for metal vapor deposition films of said (1) or (2) on the metal vapor deposition layer of the metal vapor deposition film which has a metal vapor deposition layer on the single side | surface of a base material. However, the pressure-sensitive adhesive layer is stuck so as to be in contact with the metal vapor deposition layer.

Moreover, the pressure-sensitive adhesive sheet for a touch panel according to the present invention comprises:
Acrylic copolymer having an alkyl (meth) acrylate as a main monomer component, a carboxyl group-containing monomer being copolymerized in an amount of 1% by weight or more and less than 3% by weight, and substantially free of a hydroxyl group-containing monomer. A pressure-sensitive adhesive composition comprising benzotriazole and / or its derivative (B) in an amount of 1 to 10 parts by weight with respect to 100 parts by weight of the union (A);
An epoxy crosslinking agent (C) having a functional group Z capable of reacting with the carboxyl group X in the acrylic copolymer (A),
The equivalent ratio (X: Z) of the functional group Z in the epoxy crosslinking agent (C) to the carboxyl group X in the acrylic copolymer (A) is 1: 0.01 to 1: 0.4. The pressure-sensitive adhesive layer obtained by crosslinking in an appropriate amount is formed on at least one side of the support.

  In the pressure-sensitive adhesive sheet for a touch panel, (1) the pressure-sensitive adhesive layer may be formed on one side of a support and the support may be a release material, or (2) the pressure-sensitive adhesive layer is supported. It may be formed on both sides of the body.

  According to the pressure-sensitive adhesive sheet for metal sticking, the pressure-sensitive adhesive sheet for metal vapor-deposited film and the pressure-sensitive adhesive sheet for touch panel of the present invention, it has an excellent balance between metal corrosion prevention and adhesiveness, even when used for a long time in a high-temperature and high-humidity environment. Peeling or foaming of the adhesive layer does not occur, and corrosion of the metal layer can be effectively prevented. Therefore, the pressure-sensitive adhesive sheet for metal sticking, the pressure-sensitive adhesive sheet for metal vapor-deposited film, and the pressure-sensitive adhesive sheet for touch panel of the present invention used a sticking material for a metal such as highly corrosive Ag and a metal such as highly corrosive Ag, respectively. It can apply suitably for a metal vapor deposition film label, the member for touch panels, and a touch panel.

  Moreover, since the metal vapor deposition film label of the present invention, the touch panel member, and the touch panel are each provided with a specific pressure-sensitive adhesive layer, even when used over a long period of time in a high-temperature and high-humidity environment, peeling, foaming of the pressure-sensitive adhesive layer, etc. Even when highly corrosive Ag or the like is used, corrosion of a metal layer such as a metal vapor deposition layer or a metal circuit can be effectively prevented.

Hereinafter, the present invention will be specifically described.
<Adhesive sheet for attaching metal, adhesive sheet for metal vapor deposition film, and adhesive sheet for touch panel>
The pressure-sensitive adhesive sheet for attaching metal, the pressure-sensitive adhesive sheet for metal vapor deposition film or the pressure-sensitive adhesive sheet for touch panel,
Acrylic copolymer having an alkyl (meth) acrylate as a main monomer component, a carboxyl group-containing monomer being copolymerized in an amount of 1% by weight or more and less than 3% by weight, and substantially free of a hydroxyl group-containing monomer. A pressure-sensitive adhesive composition comprising benzotriazole and / or its derivative (B) in an amount of 1 to 10 parts by weight with respect to 100 parts by weight of the union (A);
An epoxy crosslinking agent (C) having a functional group Z capable of reacting with the carboxyl group X in the acrylic copolymer (A),
The equivalent ratio (X: Z) of the functional group Z in the epoxy crosslinking agent (C) to the carboxyl group X in the acrylic copolymer (A) is 1: 0.01 to 1: 0.4. The pressure-sensitive adhesive layer obtained by crosslinking in an appropriate amount is formed on at least one side of the support.

Hereinafter, first, the acrylic copolymer (A) and the benzotriazole and / or derivative (B) constituting the pressure-sensitive adhesive composition, and the epoxy cross-linking agent (C) for cross-linking the pressure-sensitive adhesive composition are sequentially described. explain.

≪Acrylic copolymer (A) ≫
The acrylic copolymer (A) used in the present invention comprises an alkyl (meth) acrylate as a main monomer component, and a carboxyl group-containing monomer is copolymerized in an amount of 1 wt% or more and less than 3 wt%, and is substantially In particular, it is a polymer in which a hydroxyl group-containing monomer is not copolymerized.

  Specific examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, and isobutyl (meth) ) Acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, methoxyethyl (meth) acrylate and And ethoxyethyl (meth) acrylate. These monomers can be used alone or in combination.

  Among these, alkyl (meth) acrylates having 1 to 8 carbon atoms in the alkyl group are preferable. Specifically, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl acrylate, 2-ethylhexyl ( (Meth) acrylate is preferred.

  The alkyl (meth) acrylate is used as a main monomer component for copolymerization in an amount of usually 50 to 99% by weight, preferably 80 to 98% by weight when the total amount of monomers is 100% by weight.

  Examples of the carboxyl group-containing monomer include (meth) acrylic acid, β-carboxyethyl acrylate, itaconic acid, crotonic acid, fumaric acid, maleic acid, maleic anhydride, and butyl maleate. These monomers can be used alone or in combination, and among these, (meth) acrylic acid is preferable.

  The carboxyl group-containing monomer is used for copolymerization in an amount of usually 1 wt% or more and less than 3 wt%, preferably 1.5 to 2.5 wt% when the total amount of the monomers is 100 wt%. The carboxyl group of the carboxyl group-containing monomer corresponds to the carboxyl group X in the acrylic copolymer (A) described later.

  Furthermore, the acrylic copolymer (A) includes 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, chloro-2-hydroxypropyl (meth) acrylate, diethylene glycol mono (meth) acrylate and A hydroxyl group-containing monomer such as allyl alicol is not substantially copolymerized.

Thus, when the alkyl (meth) acrylate and the carboxyl group-containing monomer are copolymerized in an amount within the above range, and the hydroxyl group-containing monomer is not substantially copolymerized, the resulting acrylic copolymer (A) When benzotriazole and / or its derivative (B) is blended with and crosslinked with an epoxy crosslinking agent (C), the metal corrosion prevention effect of benzotriazole and / or its derivative (B) is effectively exhibited. The acrylic copolymer (A) can be sufficiently cross-linked by the epoxy cross-linking agent (C), and it is possible to ensure both the metal corrosion preventing ability, the cohesive force and the adhesive force of the pressure-sensitive adhesive.

Regarding securing of the former ability to prevent metal corrosion, since no hydroxyl group-containing monomer is used in the production of the acrylic copolymer (A), hydroxyl groups may be introduced into the acrylic copolymer (A). The hydroxyl group does not react with benzotriazole and / or its derivative (B) to impair its metal corrosion prevention effect, and the carboxyl group-containing monomer is used in an amount within a specific range. It is considered that the metal corrosion preventing ability of the component (B) is sufficiently exhibited even for the acrylic copolymer (A) having a carboxyl group introduced therein.

Further, regarding the securing of cohesive strength and adhesive strength of the latter pressure-sensitive adhesive, since no hydroxyl group-containing monomer is used in the production of the acrylic copolymer (A), a hydroxyl group is contained in the acrylic copolymer (A). Is not introduced, and the hydroxyl group reacts with benzotriazole and / or its derivative (B), whereby the hydroxyl group involved in the crosslinking reaction is reduced and crosslinking is not insufficient, and sufficient cohesive force is obtained. Can be secured. Moreover, it is considered that the problem of a decrease in adhesive force due to the use of a large amount of a hydroxyl group-containing monomer does not occur.

  Further, as will be described in detail later, in the present invention, the epoxy crosslinking agent (C) is used in an amount within a specific range in relation to the carboxyl group X in the acrylic copolymer (A). Excellent balance between metal corrosion prevention ability and adhesion of layer.

  In the production of the acrylic copolymer (A), other monomers may be used as necessary. Such other monomers include styrene, methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, diethyl styrene, triethyl styrene, propyl styrene, butyl styrene, hexyl styrene, heptyl styrene and octyl styrene, fluorostyrene, chlorostyrene, Examples thereof include styrene monomers such as bromostyrene, dibromostyrene and iodostyrene nitrostyrene, acetylstyrene and methoxystyrene; vinyl monomers such as vinylpyrrolidone, vinylcarbazole, divinylbenzene, vinyl acetate and acrylonitrile. These monomers can be used alone or in combination.

  The above-mentioned other monomers can be used within a range not impairing the object of the present invention. Specifically, the other monomers are used in an amount within the range of 0 to 50% by weight, preferably 0 to 20% by weight. can do.

  The acrylic copolymer (A) can be produced by copolymerization by a known method and is not particularly limited. For example, the monomer described above is charged into a reaction solvent, and the air in the reaction system is nitrogen gas. After replacement with an inert gas such as, it can be produced by heating and stirring to cause a polymerization reaction in the presence of a reaction initiator if necessary.

  As the reaction solvent used here, an organic solvent is used. Specifically, aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as n-hexane, esters such as ethyl acetate and butyl acetate. And aliphatic alcohols such as n-propyl alcohol and isopropyl alcohol, and ketones such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone.

  Moreover, when using a reaction initiator, azobisisobutyronitrile, benzoyl peroxide, di-tert-butyl peroxide, cumene hydroperoxide, etc. can be used as a reaction initiator, for example.

The reaction temperature of the above polymerization reaction is usually 50 to 90 ° C., and the reaction time is usually 2 to 20 hours, preferably 4 to 12 hours.
In the reaction as described above, each monomer can be blended according to the amount of each repeating unit in the acrylic copolymer to be obtained. The reaction solvent is used in an amount of 50 to 300 parts by weight with respect to 100 parts by weight of the total amount of monomers, and the reaction initiator is usually used in an amount of 0.01 to 10 parts by weight.

  The weight average molecular weight (measured by gel permeation chromatography) of the acrylic copolymer (A) in terms of polystyrene is preferably in the range of 300,000 to 1,500,000. When the polymerization average molecular weight is within the above range, the cohesive force of the finally obtained pressure-sensitive adhesive layer can be adjusted within a preferable range, and the adherend is in the form of a metal vapor-deposited film pressure-sensitive adhesive sheet or metal vapor-deposited film label. It can prevent peeling for a long time when it is attached to, and also prevents peeling for a long time even when the upper electrode plate and the lower electrode plate are attached and bonded as the adhesive layer of the touch panel described later. Can do.

≪Benzotriazole and / or its derivative (B) ≫
Examples of benzotriazole and / or its derivative (B) used in the present invention include benzotriazole, 4-methylbenzotriazole, 5-methylbenzotriazole, 5-chlorobenzotriazole, tolyltriazole, tolyltriazole K salt, 3- is either (N- salicyloyl) amino-1,2,4-triazole. These can be used alone or in combination, but among these, benzotriazole is preferred from the viewpoint of easy handling and the effect of preventing metal corrosion.

The benzotriazole and / or its derivative (B) is an acrylic copolymer (
A) It is desirably used in an amount of 1 to 10 parts by weight, preferably 2 to 7 parts by weight with respect to 100 parts by weight so as to be included in the pressure-sensitive adhesive composition.

When the benzotriazole and / or derivative (B) is used in an amount within the above-mentioned range, the content of the component (B) in the finally obtained pressure-sensitive adhesive layer effectively exhibits the metal corrosion preventing ability. The amount is sufficient.

≪Epoxy crosslinking agent (C) ≫
The acrylic copolymer (A) and the benzotriazole and / or its derivative (
And an epoxy crosslinking agent (C) having a functional group Z that can react with the carboxyl group X in the acrylic copolymer (A). ,
The film is added in such an amount that the equivalent ratio (X: Z) of the functional group Z in the epoxy crosslinking agent (C) to the carboxyl group X in the acrylic copolymer (A) becomes a specific ratio. The final pressure-sensitive adhesive layer can be obtained by crosslinking after film formation or film formation.

The pressure-sensitive adhesive composition can be obtained by mixing at least the acrylic copolymer (A) and the benzotriazole and / or its derivative (B) by a normal mixing technique, It is not limited. The pressure-sensitive adhesive composition may contain a solvent, and examples of the solvent include the reaction solvents described above.

  Further, the method of adding and mixing the epoxy crosslinking agent (C) to the pressure-sensitive adhesive composition and the conditions for crosslinking can be appropriately selected from known addition, mixing method and crosslinking conditions, and are not particularly limited.

  In the present invention, since the epoxy crosslinking agent (C) is used as the crosslinking agent as described above, the crosslinking agent and benzotriazoles react to inhibit the crosslinking reaction as in the case of using the isocyanate crosslinking agent. The acrylic copolymer (A) can be sufficiently crosslinked even with a relatively small amount of the epoxy crosslinking agent (C), and the cohesive strength of the adhesive in the finally obtained adhesive layer is improved. Can do.

The epoxy crosslinking agent (C) used in the present invention has a functional group Z that can react with the carboxyl group X in the acrylic copolymer (A). an epoxy group, such as grayed glycidyl group.

Examples of the epoxy crosslinking agent (C) include bisphenol A, epichlorohydrin type epoxy resin, ethylene glycol glycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, and 1,6-hexanediol diester. Glycidyl ether, trimethylolpropane triglycidyl ether, diglycidyl aniline, diglycidyl amine, N, N, N ', N'-tetraglycidyl-m-xylenediamine and 1,3-bis (N, N'-diglycidylamino Mention may be made of methyl) cyclohexane.

  The epoxy crosslinking agent (C) has an equivalent ratio (X: Z) of the functional group Z in the epoxy crosslinking agent (C) to the carboxyl group X in the acrylic copolymer (A), usually 1: It is used in an amount of 0.01 to 1: 0.4, preferably 1: 0.015 to 1: 0.1, more preferably 1: 0.015 to 1: 0.05.

  In the present invention, the epoxy crosslinking agent (C) is used in an amount within the above range with respect to the carboxyl group X in the acrylic copolymer (A), whereby the carboxyl group X is combined with the epoxy crosslinking agent (C). The crosslinking reaction is not used up completely, and a small amount of carboxyl groups remain in the acrylic copolymer (A) after the crosslinking reaction in the pressure-sensitive adhesive layer.

The carboxyl group remaining in the acrylic copolymer (A) after the crosslinking reaction is dissociated into H ⁺ and —COO ^{− in} a wet heat environment. Among these, H ⁺ is benzotriazole and / or Because of its small amount relative to its derivative (B), it is stabilized by benzotriazole and / or its derivative (B). Therefore, even if the pressure-sensitive adhesive layer and the metal are left in contact with each other for a long time, the metal corrosion hardly occurs. Furthermore, since —COO 2 ^— is present in the pressure-sensitive adhesive layer, a hydrogen bond is formed with an electron withdrawing group such as hydrogen on the surface of the adherend, and strong adhesion to the adherend is generated.

≪Manufacture of pressure-sensitive adhesive sheet for metal bonding, pressure-sensitive adhesive sheet for metal vapor deposition film and pressure-sensitive adhesive sheet for touch panel≫
The pressure-sensitive adhesive sheet for metal sticking, the pressure-sensitive adhesive sheet for metal vapor-deposited film or the pressure-sensitive adhesive sheet for touch panel of the present invention is characterized in that the pressure-sensitive adhesive layer obtained as described above is formed on at least one side of the support. .

  As a support body, what is normally used as a support body of an adhesive sheet or an adhesive tape is mentioned. Examples thereof include polycycloolefins such as polynorbornene, polyethylene, polyethylene terephthalate, polypropylene, polyvinyl chloride, polyimide, polycarbonate, cellulose triacetate resin films, paper, and nonwoven fabric.

  Furthermore, in the case of the pressure-sensitive adhesive sheet for metal vapor deposition film or the pressure-sensitive adhesive sheet for touch panel of the present invention, the support is preferably one that is generally used as a release material for pressure-sensitive adhesive sheets or pressure-sensitive adhesive tapes. The above-described resin film, paper, nonwoven fabric, or the like with one or both surfaces coated with a release agent such as a silicone resin can be used as appropriate.

What added the epoxy crosslinking agent (C) to the adhesive composition containing the said (A) component and (B) component on the one or both surfaces of such a support, for example, a doctor blade, a knife coater, By applying with a comma coater, reverse roll coater or gravure coater and removing the solvent, an adhesive layer is formed on one side or both sides of the support, and the pressure-sensitive adhesive sheet for metal sticking of the present invention, pressure-sensitive adhesive for metal vapor deposition film A sheet or an adhesive sheet for a touch panel can be obtained.

The support usually has a thickness of 4 to 100 μm, and the pressure-sensitive adhesive layer usually has a thickness of 5 to 100 μm, preferably 10 to 50 μm.
Thus, in order to protect these adhesive layers at the time of storage, the adhesive material for metal sticking obtained, the adhesive sheet for metal vapor deposition films, or the adhesive sheet for touch panels is obtained on this adhesive layer. It is preferable to paste them together. The release material is peeled off from the pressure-sensitive adhesive layer during use.
<Metal vapor deposition film label>
Next, the metal vapor deposition film label of this invention is demonstrated.

  The metal vapor-deposited film label of the present invention is formed on the metal vapor-deposited layer of the metal vapor-deposited film having a metal vapor-deposited layer on one side of the substrate, and the pressure-sensitive adhesive layer for the metal vapor-deposited film is used as the metal vapor-deposited layer. It is characterized by being stuck so as to abut.

  Specifically, (1) The pressure-sensitive adhesive layer is formed on one side of a support, and the pressure-sensitive adhesive sheet for metal vapor-deposited film in which the support is a release material, Or (2) a pressure-sensitive adhesive sheet for a metal vapor-deposited film in which the pressure-sensitive adhesive layer is formed on both sides of the support. It has a structure in which it is stuck so as to abut on the metal vapor deposition layer of the film.

An example of a more specific structure of the metal vapor-deposited film label (in the case of (1) above) will be described below with reference to FIG.
In FIG. 1, a metal vapor deposition film label 1 has an adhesive on one side of a support (release material) 3 on a metal vapor deposition layer 7 of a metal vapor deposition film 8 having a metal vapor deposition layer 7 on one side of a substrate 9. The pressure-sensitive adhesive sheet 4 for metal vapor-deposited film in which the layer 5 is formed is characterized by being stuck so that the pressure-sensitive adhesive layer 5 is in contact with the metal vapor-deposited layer 7.

  The metal vapor-deposited layer 7 can be formed by vapor-depositing a metal such as Al, Cu, Ag or the like on the substrate 9 in a thickness of about 500 mm, specifically 200 to 700 mm. The base material 9 is required to have transparency in order to make use of the reflectivity and light shielding properties of the metal vapor-deposited layer 7, and from such a viewpoint, polycycloolefin such as polynorbornene, polyethylene, polyethylene terephthalate, Preferred examples include resin films such as polypropylene, polyvinyl chloride, polycarbonate and cellulose triacetate, and the thickness is usually 10 to 200 μm.

  The metal vapor-deposited film label obtained by sticking the pressure-sensitive adhesive sheet for metal vapor-deposited film on the metal vapor-deposited layer of such a metal vapor-deposited film so as to contact the pressure-sensitive adhesive layer constitutes the pressure-sensitive adhesive layer. Since the cohesive strength and adhesive strength of the adhesive to be used are excellent, peeling from the adherend does not occur even when used for a long period of time, and problems such as foaming do not occur when used under high temperature and high humidity. Furthermore, because of its excellent ability to prevent metal corrosion, there is no harmful effect such as so-called vapor deposition loss due to corrosion of the metal layer, and it can be suitably used for applications such as building materials and packaging materials that require a metal layer. .

In addition, when the metal vapor deposition film label obtained in this way has the structure of said (2), in order to protect an adhesive layer at the time of storage, the release material mentioned above is bonded together on this adhesive layer. It is preferable to keep it. The release material is peeled off from the pressure-sensitive adhesive layer during use.
<Touch panel materials>
Next, the member for touch panels of this invention is demonstrated.

  The touch panel member of the present invention is characterized in that the touch panel pressure-sensitive adhesive sheet is attached to an electrode plate having a metal circuit on one side of a substrate so that the pressure-sensitive adhesive layer is in contact with the metal circuit. It is said.

  Specifically, (1) The pressure-sensitive adhesive sheet for the touch panel in which the pressure-sensitive adhesive layer is formed on one side of the support and the support is a release material, the pressure-sensitive adhesive layer is used as the metal of the electrode plate. Or (2) a pressure-sensitive adhesive sheet for a touch panel in which the pressure-sensitive adhesive layer is formed on both sides of a support, and the pressure-sensitive adhesive layer is placed on the metal circuit of the electrode plate. It has the structure stuck so that it may contact | abut.

  In addition, when the member for touch panels obtained in this way has the structure of said (2), in order to protect an adhesive layer at the time of storage, the release material mentioned above is bonded together on this adhesive layer. It is preferable. The release material is peeled off from the pressure-sensitive adhesive layer during use.

The substrate and metal circuit constituting the electrode plate will be described in detail in the following touch panel section.
<Touch panel>
Next, the touch panel of the present invention will be described.

In the touch panel of the present invention, in the resistive film type touch panel including the upper electrode plate and the lower electrode plate, the adhesive layer that joins the upper electrode plate and the lower electrode plate,
An acrylic copolymer comprising an alkyl (meth) acrylate as a main component, a carboxyl group-containing monomer being copolymerized in an amount of 1% by weight or more and less than 3% by weight, and substantially free of a hydroxyl group-containing monomer. (A) benzotriazole and / or 100 parts by weight
Or a pressure-sensitive adhesive composition comprising the derivative (B) in an amount of 1 to 10 parts by weight;
An epoxy crosslinking agent (C) having a functional group Z capable of reacting with the carboxyl group X in the acrylic copolymer (A),
The equivalent ratio (X: Z) of the functional group Z in the epoxy crosslinking agent (C) to the carboxyl group X in the acrylic copolymer (A) is 1: 0.01 to 1: 0.4. It is characterized by being obtained by cross-linking using a small amount.

  As a resistive film type touch panel provided with an upper electrode plate and a lower electrode plate, known ones can be mentioned, and the structure and manufacturing method thereof are not particularly limited. Specifically, for example, ITO or the like is formed on the entire surface of one side. The transparent conductive film of the outer peripheral portion is removed as necessary, and the parallel electrodes made of a metal layer such as Ag and a routing circuit are provided on the outer peripheral portion as necessary. An upper electrode plate and a lower electrode plate having an insulating layer provided accordingly are opposed to each other so that these parallel electrodes are perpendicular to each other, and are joined via an adhesive layer. The touch panel comprised by joining a wiring board with an anisotropic conductive adhesive is mentioned. In addition, it is preferable that this touch panel has a dot spacer in the part which has the transparent conductive film of a lower electrode.

An example of a more specific configuration of such a touch panel will be described along with its manufacturing method based on FIG. 2 and FIG.
FIG. 3A is a schematic view of the upper electrode plate 13 as viewed from the transparent conductive film surface side. The upper electrode plate 13 has a transparent conductive film layer 27 such as ITO provided on the entire surface of one side of the substrate 12. Then, the outer peripheral portion is etched to remove the transparent conductive film layer 27 on the outer peripheral portion, and a metal paste containing a metal such as Ag is printed on the outer peripheral portion, and the parallel electrodes made of the metal layer and the routing circuit (wiring portion 15) Further, the insulating layer 17 is formed by printing insulating ink on the wiring portion 15 and other outer peripheral portions. The substrate 12 is preferably provided with a hard coat film or an antireflection film (not shown) on the surface opposite to the transparent conductive film surface, because high transparency and mobility by pressing are required. The substrate 12 is preferably a resin film such as polycycloolefin such as polynorbornene, polyethylene, polyethylene terephthalate, polypropylene, polyvinyl chloride, polycarbonate, cellulose triacetate, and the thickness thereof is usually 10 to 200 μm. Moreover, a well-known thing can be used as said metal paste and insulating ink.

  FIG. 3B shows a double-sided adhesive tape 19. The double-sided pressure-sensitive adhesive tape 19 is obtained by providing pressure-sensitive adhesive layers on both sides of a core material for double-sided pressure-sensitive adhesive tape (not shown) and punching it into a frame shape with a press or the like. As such a double-sided adhesive tape 19, the adhesive sheet for touchscreens of this invention can be used preferably.

  FIG. 3C is a schematic view of the lower electrode plate 21 as viewed from the transparent conductive film surface side. The lower electrode plate 21 is provided with a transparent conductive film layer 27 such as ITO on the entire surface of one side of the substrate 20. The outer peripheral portion is etched to remove the transparent conductive film layer 27 on the outer peripheral portion, a metal paste containing a metal such as Ag is printed on the outer peripheral portion, and the parallel electrodes made of the metal layer and the routing circuit (wiring portion 15) are provided. Furthermore, an insulating ink is printed on the wiring portion 15 and other outer peripheral portions to form an insulating layer 17, and an anisotropic conductive adhesive is applied to the FRP connecting portion provided in a part of the routing circuit. It is obtained by printing to form the anisotropic conductive adhesive layer 23. In addition, it is preferable that the lower electrode plate 21 has a dot spacer (not shown) in a portion having the transparent conductive film layer 27.

  In addition, since the substrate 20 is required to have high transparency, a resin film such as polycycloolefin such as polynorbornene, polyethylene, polyethylene terephthalate, polypropylene, polyvinyl chloride, polycarbonate, cellulose triacetate, glass, or the like is preferably used. The thickness is usually 10 to 200 μm. Moreover, a well-known thing can be used as said metal paste, insulating ink, and anisotropic conductive adhesive.

  2A and 2B, the upper electrode plate 13 and the lower electrode plate 21 of FIGS. 3A and 3C are laminated via the double-sided adhesive tape 19 of FIG. II ′ line schematic cross-sectional view of the touch panel 11, which is an embodiment of the touch panel of the present invention, which is configured by thermocompression bonding of the FRP 25 via the anisotropic conductive adhesive layer 23 at the same time as bonding and bonding by the above. It is. In addition, as FRP25, a well-known thing can be used.

In the touch panel of the present invention, in the touch panel having such a configuration, the pressure-sensitive adhesive layer joining the upper electrode plate and the lower electrode plate includes the acrylic copolymer (A), the benzotriazole and / or a derivative thereof. An epoxy crosslinking agent (C) having a functional group Z capable of reacting with the carboxyl group X in the acrylic copolymer (A) in the pressure-sensitive adhesive composition comprising (B) in an amount within the above-described range. Is used in such an amount that the equivalent ratio (X: Z) of the functional group Z in the epoxy crosslinking agent (C) to the carboxyl group X in the acrylic copolymer (A) becomes a specific ratio. It is the thing obtained by doing.

As such an adhesive layer, what was demonstrated as an adhesive layer of the adhesive sheet for metal vapor deposition films of this invention is mentioned.
EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to these Examples. In the following examples, parts and% are based on weight unless otherwise specified.

The nonvolatile content and viscosity of the acrylic copolymer solution and the weight average molecular weight of the acrylic copolymer were determined by the following methods.
<Nonvolatile content of acrylic copolymer solution>
About 1 g of the acrylic copolymer solution was put into a precisely weighed tin plate (n1), and the total weight (n2) was precisely weighed, followed by heating at 105 ° C. for 3 hours. Thereafter, this tin plate was allowed to stand in a desiccator at room temperature for 1 hour, and then precisely weighed again to measure the total weight (n3) after heating.

The nonvolatile content was calculated from the following formula using the obtained weight measurement values (n1 to n3).
Nonvolatile content (%) = 100 × [weight after heating (n3−n1) / weight before heating (n2−n1)]
<Measurement of viscosity of acrylic copolymer solution>
It measured at room temperature using Viscometer model BM (made by Toki Sangyo Co., Ltd.).
<Molecular weight measurement of acrylic copolymer>
Using HLC-8120 (manufactured by Tosoh Corporation), the weight average molecular weight was measured under the following conditions using polystyrene as a standard substance.

Column used: G7000HXL × 1, GMHXL × 2, G2000HXL × 1, solvent; THF, flow rate;
1.0 ml / min, measuring temperature; 40 ° C

<Polymerization of acrylic copolymer>
In a four-necked flask capable of nitrogen substitution, 98.5 parts of butyl acrylate (hereinafter abbreviated as BA), 1.5 parts of acrylic acid (hereinafter abbreviated as AA), and 150 parts of ethyl acetate were placed under nitrogen substitution. To 68 ° C., 0.15 part of azobisisobutyronitrile (hereinafter abbreviated as AIBN) was added, and polymerization was started. 2,5,5 hours after the start of polymerization, 0.15 parts of AIBN was added, and 150 parts of ethyl acetate was further added 6 hours and 30 minutes after the start of polymerization to complete the polymerization.

  The obtained acrylic copolymer solution had a non-volatile content of 24.8% and a viscosity of 3.0 Pa · s. Moreover, the polystyrene conversion weight average molecular weight of the acrylic copolymer (nonvolatile content) was 800,000.

<Creation of pressure-sensitive adhesive sheet for metal vapor deposition film and metal vapor deposition film label>
5 parts of metal deactivator BTZM (manufactured by Kyodo Kagaku Co., Ltd.) and epoxy hardener Tetrad X (Mitsubishi Gas Chemical ( 0.05 parts) is mixed to prepare a coating material (the equivalent ratio (X: Z) of the functional group Z in the epoxy crosslinking agent to the carboxyl group X in the acrylic copolymer is 1: 0.026), a pressure-sensitive adhesive by applying the coating agent on a release-treated surface of a release polyethylene terephthalate film PET3811 (manufactured by Lintec Corporation) with a doctor blade so that the film thickness after drying is 25 μm and drying. The layer was formed and the adhesive sheet A for metal vapor deposition films was obtained. Thereafter, the adhesive layer of the pressure-sensitive adhesive sheet for metal-deposited film A was bonded to the aluminum-deposited surface made of 25 μm-thick aluminum-deposited PET (Toray Industries, Inc.), and aged for one week at room temperature. The vapor deposition film label A was created.

<Mounting test>
The metal vapor-deposited film label A is cut to a width of 50 mm × a length of 120 mm, and after PET3811 is peeled off, it is bonded to a glass plate having a width of 70 mm × a length of 150 mm × a thickness of 2 mm through the exposed adhesive layer, The mixture was autoclaved at 50 ° C. × 5 kg / cm ² × 20 minutes, and allowed to stand in an environment of 60 ° C. and relative humidity of 95% for 500 hours. Thereafter, when the change in appearance was visually observed, no change in appearance was observed as shown in Table 1, and good reflectivity and light shielding properties were exhibited.

Example 1 except that BA was changed to 97.7 parts and AA was changed to 2.3 parts according to the blending ratio in Table 1.
In the same manner as above, an acrylic copolymer solution was obtained. The acrylic copolymer solution had a nonvolatile content of 24.9% and a viscosity of 4 Pa · s. Moreover, the polystyrene conversion weight average molecular weight of the acrylic copolymer (non-volatile content) was 820,000.

  5 parts of metal deactivator BTZM (manufactured by Kyodo Kagaku Co., Ltd.) and epoxy hardener Tetrad X (Mitsubishi Gas Chemical ( 0.05 parts) is mixed to prepare a coating material (the equivalent ratio (X: Z) of the functional group Z in the epoxy crosslinking agent to the carboxyl group X in the acrylic copolymer is 1: 0) 0.017), a metal vapor-deposited film pressure-sensitive adhesive sheet B and a metal vapor-deposited film label B were prepared in the same manner as in Example 1.

  When the mounting test was performed in the same manner as in Example 1 using the metal vapor-deposited film label B, the appearance was not changed even after being left in an environment of 60 ° C. and a relative humidity of 95% for 500 hours. Showed good reflectivity and light shielding properties.

  For 100 parts of the nonvolatile content of the acrylic copolymer solution prepared in Example 2, 1.5 parts of a metal deactivator BTZM (manufactured by Kyodo Kagaku Co., Ltd.) and an epoxy curing agent Tetrad X as an epoxy crosslinking agent 0.05 parts (Mitsubishi Gas Chemical Co., Ltd.) are mixed to prepare a coating material (equivalent ratio of functional group Z in the epoxy crosslinking agent to carboxyl group X in the acrylic copolymer (X: Z)) Were prepared in the same manner as in Example 1, except that the ratio was 1: 0.017).

  When the mounting test was performed in the same manner as in Example 1 using the metal vapor-deposited film label C, no change in appearance was observed even after standing in an environment of 60 ° C. and a relative humidity of 95% for 500 hours. Showed good reflectivity and light shielding properties.

  5 parts of metal deactivator BTZM (manufactured by Kyodo Yakuhin Co., Ltd.) and epoxy type curing agent Tetrad X (Mitsubishi) as an epoxy crosslinking agent with respect to 100 parts of the nonvolatile content of the acrylic copolymer solution prepared in Example 1 0.7 parts of Gas Chemical Co., Ltd.) was mixed to prepare a coating material (the equivalent ratio (X: Z) of the functional group Z in the epoxy crosslinking agent to the carboxyl group X in the acrylic copolymer) 1: 0.37) A metal vapor-deposited film pressure-sensitive adhesive sheet D and a metal vapor-deposited film label D were prepared in the same manner as in Example 1.

  When the mounting test was performed in the same manner as in Example 1 using the metal vapor-deposited film label D, the appearance was not changed even after being left in an environment of 60 ° C. and a relative humidity of 95% for 500 hours. Showed good reflectivity and light shielding properties.

  10 parts of a metal deactivator BTZM (manufactured by Kyodo Kagaku Co., Ltd.) with respect to 100 parts of the nonvolatile content of the acrylic copolymer solution prepared in Example 1, and an epoxy curing agent Tetrad X (Mitsubishi) as an epoxy crosslinking agent 0.7 parts of Gas Chemical Co., Ltd.) was mixed to prepare a coating material (the equivalent ratio (X: Z) of the functional group Z in the epoxy crosslinking agent to the carboxyl group X in the acrylic copolymer) 1: 0.37) A metal vapor-deposited film pressure-sensitive adhesive sheet E and a metal vapor-deposited film label E were prepared in the same manner as in Example 1.

  When the mounting test was performed in the same manner as in Example 1 using the metal vapor-deposited film label E, the appearance was not changed even after being left in an environment of 60 ° C. and a relative humidity of 95% for 500 hours. Showed good reflectivity and light shielding properties.

[Comparative Example 1]
According to the blending ratio in Table 1, an acrylic copolymer solution was used in the same manner as in Example 2 except that 2.3 parts of 2-hydroxyethyl acrylate (hereinafter abbreviated as HEA) was used instead of 2.3 parts of AA. Got. The acrylic copolymer solution had a nonvolatile content of 24.8% and a viscosity of 3.5 Pa · s. Moreover, the polystyrene conversion weight average molecular weight of the acrylic copolymer (non-volatile content) was 850,000.

  5.0 parts of metal deactivator BTZM (manufactured by Kyodo Chemical Co., Ltd.) and epoxy hardener Tetrad X (Mitsubishi Gas Chemical Co., Ltd.) with respect to 100 parts of the non-volatile content of the obtained acrylic copolymer solution In addition to 2.0 parts of an isocyanate-based cross-linking agent Coronate L (manufactured by Nippon Polyurethane Co., Ltd.), and a coating agent was prepared in place of And the metal vapor deposition film label F was created.

  When the mounting test was performed in the same manner as in Example 1 using the metal vapor-deposited film label F, the foam was formed on the entire surface of the metal vapor-deposited film label F after being left in an environment of 60 ° C. and a relative humidity of 95% for 500 hours. Produced and did not show good reflectivity.

[Comparative Example 2]
According to the blending ratio of Table 1, an acrylic copolymer solution was obtained in the same manner as in Example 1 except that BA was changed from 98.5 parts to 93 parts and AA 1.5 parts was changed to 7 parts. The acrylic copolymer solution had a nonvolatile content of 24.8% and a viscosity of 6.0 Pa · s. Moreover, the polystyrene conversion weight average molecular weight of the acrylic copolymer (non-volatile content) was 820,000.

  5.0 parts of metal deactivator BTZM (manufactured by Kyodo Chemical Co., Ltd.) and epoxy hardener Tetrad X (Mitsubishi Gas Chemical Co., Ltd.) with respect to 100 parts of the non-volatile content of the obtained acrylic copolymer solution 0.05 parts) and a coating agent was prepared (the equivalent ratio (X: Z) of the functional group Z in the epoxy crosslinking agent to the carboxyl group X in the acrylic copolymer was 1: 0.006). The metal-deposited film pressure-sensitive adhesive sheet G and the metal-deposited film label G were prepared in the same manner as in Example 1.

  When the mounting test was performed in the same manner as in Example 1 using the metal vapor-deposited film label G, the sample was left in an environment of 60 ° C. and a relative humidity of 95% for 500 hours, and then the metal vapor-deposited film label G was completely deposited on the entire surface. (Corrosion of the metal layer) occurred, and good reflectivity and light shielding properties were not exhibited.

[Comparative Example 3]
For 100 parts of the non-volatile content of the acrylic copolymer solution prepared in Comparative Example 2, 3.0 parts of metal deactivator BTZM (manufactured by Kyodo Chemical Co., Ltd.) and epoxy type curing agent Tetrad X (Mitsubishi Gas Chemical) 8.65 parts of Co., Ltd. was mixed to prepare a coating material (the equivalent ratio (X: Z) of the functional group Z in the epoxy crosslinking agent to the carboxyl group X in the acrylic copolymer was 1: 0.991), a metal vapor-deposited film pressure-sensitive adhesive sheet H and a metal vapor-deposited film label H were prepared in the same manner as in Example 1.

  When the mounting test was performed in the same manner as in Example 1 using the metal vapor-deposited film label H, the metal vapor-deposited film label H was peeled off after being left in an environment of 60 ° C. and a relative humidity of 95% for 500 hours. It did not show good reflectivity and shading.

[ Reference Examples 1 to 5 and Comparative Reference Examples 1 to 3 ]
<Creation of adhesive sheet for touch panel>
In the same manner as in Examples 1 to 5 and Comparative Examples 1 to 3, a coating agent was prepared, and using these coating agents, a doctor blade was applied to the release-treated surface of a release polyethylene terephthalate film PET3811 (manufactured by Lintec Corporation). The first pressure-sensitive adhesive layer was formed by coating and drying the coating agent so that the film thickness after drying was 25 μm, and then a 25 μm-thick PET film (Toray Industries, Inc.) was formed on the pressure-sensitive adhesive layer. ), Product name; Lumirror) was laminated to create an adhesive sheet.

  Next, the same coating material used for the preparation of the pressure-sensitive adhesive sheet is applied to the release-treated surface of the release polyethylene terephthalate film PET3801 (manufactured by Lintec Corporation) so that the film thickness after drying with a doctor blade is 25 μm. After coating and drying, a second pressure-sensitive adhesive layer is formed, and the pressure-sensitive adhesive layer and the 25 μm-thick PET film surface of the pressure-sensitive adhesive sheet prepared above are laminated so as to come into contact with each other at room temperature. Aged for 7 days, double-sided adhesive tape thickness 75 μm (first adhesive layer thickness 25 μm + 25 μm thick PET film (double-sided adhesive tape core material) + second adhesive layer thickness 25 μm = 75 μm) (Corresponding to the coating agents used in Examples 1 to 5 and Comparative Examples 1 to 3, respectively).

<Electrode corrosion test>
A conductive paste containing Ag powder filler (manufactured by Toyobo Co., Ltd., trade name: DW-259H-) on one side of a 188 μm thick PET film (trade name; Lumirror, manufactured by Toray Industries, Inc.) having a width of 50 mm and a length of 100 mm 5) was applied so that the thickness of the conductive layer after drying and thermosetting was 5 μm, width 2 mm × length 100 mm, and sample a was prepared.

The sample a was cut into a width of 20 mm and a length of 100 mm so that the conductive layer (width 2 mm × length 100 mm) was located at the center of the test piece, thereby preparing a test piece a.
Next, the PET 3801 is peeled off from the pressure-sensitive adhesive sheet A for touch panel, and a 25 μm thick PET film (trade name: Lumirror) manufactured by Toray Industries, Inc. is bonded to the second pressure-sensitive adhesive layer instead. Cut to 90 mm. The PET 3811 is peeled off from the cut adhesive sheet A for touch panel, and the adhesive sheet A for touch panel is tested so as to cover the other conductive layer part while leaving both ends of the conductive layer through the first adhesive layer. It stuck on the center part of the piece a.

After measuring the electrical resistance R0 at both ends of the conductive layer of this test piece a with a tester (manufactured by Sanwa Denki Keiki Co., Ltd .; Digital Multimeter PC510), the test piece a is set to 80 ° C. and relative humidity 90%. And placed in a constant temperature and humidity chamber for 500 hours. Then, the electrical resistance value R1 of the both ends of the conductive layer of the test piece a was measured with the above tester.

In addition, also about the adhesive sheets B-H for touchscreens, the electrical resistance values R0 and R1 were measured in the same manner as described above.
The electrode corrosivity of the pressure-sensitive adhesive sheets A to H for the touch panel was evaluated using the R1 / R0 value obtained from the measured values of R0 and R1 as the resistance value change rate. The results are summarized in Table 2.

<Peeling resistance test>
Anti-glare hard coat resin solution a (Nippon Kayaku Co., Ltd., KAYANOVA FOP-1100) and b (Nippon Kayaku Co., Ltd.) on one side of a 188 μm thick PET film (trade name: Lumirror, manufactured by Toray Industries, Inc.) Manufactured by KAYANOVA FOP-200A) at a solid weight ratio of 50/50, and dried so that the thickness of the antiglare hard coat layer after UV curing is 5 μm. It cut | judged to 70 mm x length 150mm, and created the sample b.

  Touch panel adhesive sheet A cut to 2 mm width on four sides of a glass plate measuring 70 mm wide x 150 mm long x 2 mm thick, and the PET 3811 is peeled off from the pressure sensitive adhesive sheet A for touch panel via the first adhesive layer Further, the PET 3801 is peeled off from the pressure-sensitive adhesive sheet A for touch panel, and the second adhesive layer is bonded to the surface opposite to the anti-glare hard coat layer surface of the sample b. Piece b was created.

After putting this test piece b into an 85 degreeC thermostat for 500 hours, the change of the external appearance was observed visually.
In addition, about the adhesive sheet BH for touchscreens, the change of the external appearance was observed similarly to the above.

  The results are summarized in Table 2.

FIG. 1 is a schematic view showing an example of a metal vapor deposition film label of the present invention. FIG. 2 is a schematic cross-sectional view showing one embodiment of the touch panel of the present invention. FIG. 3 is a schematic view of members constituting one aspect of the touch panel of the present invention.

Explanation of symbols

1: Metal vapor deposition film label 3: Support (peeling material)
4: Adhesive sheet for metal vapor deposition film 5: Adhesive layer 7: Metal vapor deposition layer 8: Metal vapor deposition film 9: Base material 11: Touch panel 12: Upper substrate 13: Upper electrode plate 15: Wiring part 17: Insulating layer 19: Both sides Adhesive tape (adhesive layer)
20: Lower substrate 21: Lower electrode plate 23: Anisotropic conductive adhesive layer 25: FRP
27: Transparent conductive film layer

Claims (11)

Acrylic copolymer having an alkyl (meth) acrylate as a main monomer component, a carboxyl group-containing monomer being copolymerized in an amount of 1% by weight or more and less than 3% by weight, and substantially free of a hydroxyl group-containing monomer. polymer (a) with respect to 100 parts by weight, benzotriazole, 4-methylbenzotriazole, 5-methylbenzotriazole, at least one kind selected 5-chloro-benzotriazole, from Li Cheng group by K salt of tolyltriazole and tolyltriazole Benzotriazole (B) in an amount of 1 to 10 parts by weight,
An epoxy crosslinking agent (C) having a functional group Z capable of reacting with the carboxyl group X in the acrylic copolymer (A),
The equivalent ratio (X: Z) of the functional group Z in the epoxy crosslinking agent (C) to the carboxyl group X in the acrylic copolymer (A) is 1: 0.01 to 1: 0.4. A small amount of carboxyl groups remain in the acrylic copolymer after the crosslinking reaction without using up all of the carboxyl groups X in the crosslinking reaction with the epoxy crosslinking agent (C). a small amount of the carboxyl group of, H ⁺ and -COO under wet heat environment ^- - dissociated into and was stabilized adhesive layer with a small amount of H ⁺ is benzotriazole Le of residuum (B) is the support A metal sticking pressure-sensitive adhesive sheet, which is formed on at least one side.   The pressure-sensitive adhesive sheet for metal sticking according to claim 1, wherein the pressure-sensitive adhesive layer is formed on both surfaces of the support.   It is used for sticking to a metal vapor deposition film, The adhesive sheet for metal sticking of Claim 1 characterized by the above-mentioned.   The pressure-sensitive adhesive sheet for metal sticking according to claim 3, wherein the pressure-sensitive adhesive layer is formed on one side of a support, and the support is a release material. The pressure-sensitive adhesive sheet for metal sticking according to claim 2 or 4 abuts the pressure-sensitive adhesive layer on the metal vapor-deposited layer on the metal vapor-deposited layer of the metal vapor-deposited film having a metal vapor-deposited layer on one side of the substrate. label for metallized film you characterized in that it is stuck by way.   The metal-bonding pressure-sensitive adhesive sheet according to claim 1, wherein the metal-bonding pressure-sensitive adhesive sheet is used for bonding to an electrode plate provided with a metal circuit of a touch panel.   The pressure-sensitive adhesive sheet for metal sticking according to claim 6, wherein the pressure-sensitive adhesive layer is formed on one side of a support, and the support is a release material.   The said adhesive layer is formed in both surfaces of a support body, The adhesive sheet for metal sticking of Claim 6 characterized by the above-mentioned. The electrode plate formed comprises a metal circuit on one surface of the substrate, that metal sticking pressure-sensitive adhesive sheet according to claim 7 or 8, are adhered to the adhesive layer so as to contact with the metal circuit touch panel member, wherein.   The pressure-sensitive adhesive sheet for metal sticking according to claim 6, which is used for joining the upper electrode plate and the lower electrode plate of a resistive film type touch panel including an upper electrode plate and a lower electrode plate. The said adhesive layer is formed in both surfaces of a support body, The metal sticking adhesive sheet of Claim 10 characterized by the above-mentioned.

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