KR20160140778A - Adhesive and adhesive sheet - Google Patents

Abstract

A sticky composition containing a (meth) acrylic acid ester polymer (A) containing 8 to 30 mass% of a monomer having a reactive functional group and an abietic acid ester-based adhesive liquid (B) as monomer units constituting the polymer A pressure-sensitive adhesive comprising a crosslinked gel having a gel fraction of 30 to 95%. Such a pressure-sensitive adhesive is excellent in both blister resistance and step-wise followability.

Description

[0001] ADHESIVE AND ADHESIVE SHEET [0002]

The present invention relates to a pressure-sensitive adhesive and a pressure-sensitive adhesive sheet which can be used for a touch panel or the like.

2. Description of the Related Art Various types of mobile electronic devices such as mobile phones and tablet terminals have a display using a display module having a liquid crystal element, a light emitting diode (LED element), an organic electroluminescence (organic EL) The display becomes a touch panel.

In such a display, a protective panel is usually formed on the surface side of the display module. Along with the reduction in thickness and weight of electronic devices, the protective panel has been changed from a conventional glass plate to a plastic plate such as an acrylic plate or a polycarbonate plate.

Between the protective panel and the display body module, a gap is formed so that the deformed protective panel does not hit the display body module even when the protective panel is deformed by an external force.

However, if such air gaps are present, there is a problem that the reflection loss of light due to the refractive index difference between the protective panel and the air layer and the refractive index difference between the air layer and the display module is large, thereby degrading the display quality.

Therefore, it has been proposed to improve the image quality of the display by filling the gap between the protective panel and the display module with the adhesive layer. However, on the side of the display body module of the protective panel, the printed layer of the frame shape may exist as a step difference. If the pressure-sensitive adhesive layer does not follow the step, the pressure-sensitive adhesive layer is excited near the step, thereby causing reflection loss of light. Therefore, the pressure-sensitive adhesive layer is required to follow the step.

In order to solve the above problem, Patent Document 1 discloses a pressure-sensitive adhesive layer for filling a gap between a protective panel and a display module, wherein a shear storage modulus (G ') at 25 ° C and 1 Hz is 1.0 × 10 ⁵ Pa or less, And a pressure-sensitive adhesive layer having a gel fraction of 40% or more.

Patent Document 1; Japanese Laid-Open Patent Publication No. 2010-97070

In Patent Document 1, it is intended to improve the step-following ability by lowering the storage modulus at room temperature in the pressure-sensitive adhesive layer. However, if the storage elastic modulus at room temperature is lowered as described above, the storage elastic modulus at high temperature is lowered more than necessary, and a problem occurs under the durability condition. For example, when high-temperature and high-humidity conditions are applied, bubbles are generated in the vicinity of the stepped portion, out gas is generated from the plastic plate as a protective panel, and blisters such as bubbles, lifting and peeling occur. On the other hand, if the pressure-sensitive adhesive layer is hardened to improve the blister resistance, the step-wise followability deteriorates.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a pressure-sensitive adhesive and a pressure-sensitive adhesive sheet excellent in both blister resistance and step-wise followability.

In order to achieve the above object, first, the present invention provides a process for producing a polymer, which comprises, as a monomer unit constituting a polymer, a (meth) acrylic acid ester polymer (A) containing 8 to 30 mass% of a monomer having a reactive functional group, A pressure-sensitive adhesive comprising a pressure-sensitive adhesive composition obtained by crosslinking a pressure-sensitive adhesive composition containing a vulcanizable liquid (B), wherein the pressure-sensitive adhesive has a gel fraction of 30 to 95% (Invention 1).

In the above invention (Invention 1), the wettability improvement effect of the abietic acid ester-based adhesive resin liquid (B) and the effect of improving the wettability of the (meth) acrylic acid ester polymer (A) with the reactive functional group and the abietic acid ester- (B) improves the adhesion of the pressure-sensitive adhesive to the adherend, and the blister resistance is excellent. Further, the pressure-sensitive adhesive does not need to be hardened to improve the blister resistance, and further, the gel fraction is in the above range, so that the pressure-sensitive adhesive layer made of the pressure-sensitive adhesive is excellent in step-wise followability.

In the above invention (Invention 1), it is preferable that the (meth) acrylic acid ester polymer (A) contains a hard monomer having a glass transition temperature of 70 ° C or more as a homopolymer as a monomer unit constituting the polymer ).

In the above invention (Invention 1 or 2), the (meth) acrylic acid ester polymer (A) preferably contains 2-ethylhexyl (meth) acrylate as the monomer unit constituting the polymer (Invention 3).

In the above invention (Inventions 1 to 3), the weight average molecular weight of the (meth) acrylic acid ester polymer (A) is preferably 200,000 to 120,000 (Invention 4).

In the above invention (Invention 1 to 4), it is preferable that the adhesive composition further contains a crosslinking agent (C) (Invention 5).

Secondly, the present invention provides a pressure-sensitive adhesive sheet comprising two release sheets and a pressure-sensitive adhesive layer sandwiched between the release sheets so as to contact the release surfaces of the two release sheets, wherein the pressure-sensitive adhesive layer comprises the pressure- (Invention 6).

In the above invention (Invention 6), it is preferable that the pressure-sensitive adhesive layer is disposed between two patterned transparent conductive films or between the patterned transparent conductive film and the cover material or the display module.

The pressure-sensitive adhesive and pressure-sensitive adhesive sheet according to the present invention are excellent both in resistance to blistering and in step-wise followability.

1 is a cross-sectional view of a pressure-sensitive adhesive sheet according to an embodiment of the present invention.
2 is a cross-sectional view showing a configuration example of a touch panel.

Hereinafter, embodiments of the present invention will be described.

〔adhesive〕

The pressure-sensitive adhesive relating to this embodiment is a pressure-sensitive adhesive comprising a (meth) acrylic acid ester polymer (A) containing 8 to 30 mass% of a monomer having a reactive functional group (reactive functional group-containing monomer) as a monomer unit constituting the polymer, A pressure-sensitive adhesive comprising a pressure-sensitive adhesive composition (hereinafter also referred to as "pressure-sensitive adhesive composition (P)") containing a pressure-sensitive adhesive liquid (B) in a crosslinked state and having a gel fraction of 30 to 95%. The sticky composition (P) preferably further contains a cross-linking agent (C).

In the present specification, the term "(meth) acrylate" means both of an acrylate ester and a methacrylate ester. Other similar terms are also the same. The term " polymer " includes the concept of " copolymer ".

The abietic acid ester-based adhesive liquid (B) is liquid at room temperature. The pressure-sensitive adhesive obtained by crosslinking the pressure-sensitive adhesive composition (P) containing the abietic acid ester-based adhesive liquid (B) improves the wettability and improves the adhesion to the adherend. In addition, the (meth) acrylic acid ester polymer (A) contains a relatively large amount of the reactive functional group-containing monomer as the monomer unit constituting the polymer, so that the reactive functional group and the abietic acid ester- So that the adhesion to the adherend is further improved. As a result, the pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive is excellent in blister resistance. Further, the pressure-sensitive adhesive does not need to be hardened to improve blister resistance, and further, the gel fraction is within the above-mentioned range, so that the pressure-sensitive adhesive layer made of the pressure-sensitive adhesive is excellent in step-wise followability. That is, according to the pressure-sensitive adhesive relating to the present embodiment, it is possible to achieve compatibility between blister resistance and step-wise followability in a trade-off relationship.

Therefore, for example, when the pressure-sensitive adhesive layer made of the pressure-sensitive adhesive is applied to the side of the plastic plate where the step is present, the pressure-sensitive adhesive layer follows the step, so that there is no lifting or bubbling in the vicinity of the step. Further, even when the laminated body of the pressure-sensitive adhesive layer and the plastic plate is subjected to durability conditions, bubbles are prevented from being generated in the vicinity of the step, and even if out gas is generated from the plastic plate, blisters such as bubbles, .

(1) (Meth) acrylic acid ester polymer (A)

(Meth) acrylic acid ester polymer (A) as a monomer unit constituting the polymer is preferably a monomer having a hydroxyl group in the molecule (a hydroxyl group-containing monomer), a monomer having a carboxyl group in the molecule (a monomer having a carboxyl group ), A monomer having an amino group in the molecule (an amino group-containing monomer), and the like. Among them, a hydroxyl group-containing monomer and a carboxyl group-containing monomer are preferable, and a hydroxyl group-containing monomer is particularly preferable. By using a hydroxyl group-containing monomer, in particular, by using a combination of a hydroxyl group-containing monomer and an isocyanate-based cross-linking agent as a cross-linking agent (C) to be described later, the resulting pressure-sensitive adhesive has better blister resistance.

Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (Meth) acrylic acid hydroxyalkyl esters such as 3-hydroxybutyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate. Among them, 2-hydroxyethyl (meth) acrylate is preferable in view of reactivity of the hydroxyl group in the obtained (meth) acrylic acid ester polymer (A) with the crosslinking agent (C) and copolymerization with other monomers. These may be used alone or in combination of two or more.

Examples of the carboxyl group-containing monomer include ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid and citraconic acid. Among them, acrylic acid is preferable in view of the reactivity of the carboxyl group in the resulting (meth) acrylic acid ester polymer (A) with the crosslinking agent (C) and the copolymerization with other monomers. These may be used alone or in combination of two or more.

Examples of the amino group-containing monomer include aminoethyl (meth) acrylate and n-butylaminoethyl (meth) acrylate. These may be used alone or in combination of two or more.

As described above, the (meth) acrylic acid ester polymer (A) contains 8 to 30 mass% of a monomer having a reactive functional group as a monomer unit constituting the polymer. If the content of the reactive functional group-containing monomer is less than 8% by mass, interaction with the abietic acid ester-based adhesive liquid (B) does not occur easily, and the resultant pressure-sensitive adhesive becomes inferior in blister resistance. On the other hand, if the content of the reactive functional group-containing monomer exceeds 30 mass%, the desired tackiness can not be obtained.

When the (meth) acrylic acid ester polymer (A) contains a hydroxyl group-containing monomer as the reactive functional group-containing monomer constituting the polymer, the content thereof is preferably 10 to 25 mass%, more preferably 15 to 20 mass% Do. When the (meth) acrylic acid ester polymer (A) contains a carboxyl group-containing monomer as the reactive functional group-containing monomer constituting the polymer, the content thereof is preferably 8 to 25 mass%, more preferably 10 to 15 mass% .

Here, when the touch panel or the like is placed under an environment of high temperature and high humidity, there is a problem of "wet heat whitening" in which the pressure-sensitive adhesive layer is whitened and transparency is lowered when moisture penetrates into the pressure sensitive adhesive layer and the touch panel or the like returns to room temperature. When the (meth) acrylic acid ester polymer (A) contains the reactive functional group-containing monomer within the above-mentioned range, a predetermined amount of reactive functional groups remain in the pressure-sensitive adhesive layer. The reactive functional group is usually a hydrophilic group. When such a hydrophilic group is present in a predetermined amount of the pressure-sensitive adhesive layer, even when the pressure-sensitive adhesive layer is placed under high temperature and high humidity conditions, compatibility with moisture penetrated into the pressure- Whitening of the pressure-sensitive adhesive layer is suppressed, and the pressure-sensitive adhesive layer is excellent in anti-wet heat and whitening resistance.

The (meth) acrylic acid ester polymer (A) preferably contains a (meth) acrylic acid alkyl ester having 1 to 20 carbon atoms in the alkyl group as the monomer unit constituting the polymer. As a result, the resulting pressure-sensitive adhesive can exhibit desirable tackiness. Further, the hard monomer to be described later is excluded from the (meth) acrylic acid alkyl ester.

Examples of the (meth) acrylic acid alkyl ester having 1 to 20 carbon atoms in the alkyl group include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (Meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl Myristyl, palmityl (meth) acrylate, stearyl (meth) acrylate, and the like. Among them, (meth) acrylic acid esters having 1 to 8 carbon atoms in the alkyl group are preferable from the standpoint of further improving the tackiness, particularly preferable are n-butyl (meth) acrylate and 2-ethylhexyl (meth) ) 2-ethylhexyl acrylate is more preferred. By using 2-ethylhexyl (meth) acrylate, the dielectric constant of the obtained pressure sensitive adhesive can be lowered, and the response precision of the touch panel can be improved. These may be used alone or in combination of two or more.

The (meth) acrylic acid ester polymer (A) preferably contains 30 to 90 mass% of a (meth) acrylic acid alkyl ester having 1 to 20 carbon atoms in the alkyl group as the monomer unit constituting the polymer, By mass, more preferably from 50 to 65% by mass.

The (meth) acrylic acid ester polymer (A) preferably contains a hard monomer having a glass transition temperature (Tg) of 70 ° C or more as a homopolymer as a monomer unit constituting the polymer. By containing the hard monomer as a monomer unit constituting the (meth) acrylic acid ester polymer (A), the resulting pressure sensitive adhesive exhibits further improved cohesion and better blister resistance. Particularly, when 2-ethylhexyl (meth) acrylate is used as the monomer unit constituting the (meth) acrylic acid ester polymer (A), the cohesive force tends to be lowered. Therefore, it is preferable to use the hard monomer. The homopolymer of the hard monomer preferably has a glass transition temperature (Tg) of 75 to 200 캜, particularly 80 to 180 캜.

Examples of the hard monomer include methyl methacrylate (Tg 105 ° C), isobornyl acrylate (Tg 94 ° C), isobornyl methacrylate (Tg 180 ° C), acryloylmorpholine (Tg 145 (Tg 115 ° C), adamantyl methacrylate (Tg 141 ° C), dimethylacrylamide (Tg 89 ° C), and acrylamide (Tg 165 ° C). These may be used alone or in combination of two or more.

Among the above hard monomers, methyl methacrylate, isobornyl acrylate and acryloyl morpholine are more preferable, and metha-methyl acrylate is more preferable from the viewpoint of exhibiting the performance of the hard monomer while preventing adverse effects on other properties such as adhesiveness and transparency. Methyl acrylate is particularly preferred.

The (meth) acrylic acid ester polymer (A) preferably contains the hard monomer in an amount of 10 to 45 mass%, particularly preferably 15 to 30 mass%, as the monomer unit constituting the polymer. By containing the hard monomer in an amount of 10% by mass or more, the effect of improving the blister resistance by the monomer unit can be expected. On the other hand, by setting the content of the hard monomer to 45 mass% or less, it is possible to prevent the relative lack of other monomer units in the (meth) acrylic acid ester polymer (A), and to obtain excellent tackiness and step traceability .

The (meth) acrylic acid ester polymer (A) may contain other monomers as monomer units constituting the polymer as desired. As other monomers, monomers that do not contain a reactive functional group are preferable, in order not to interfere with the action of the reactive functional group-containing monomer. Examples of such other monomers include (meth) acrylic acid esters having an aliphatic ring such as (meth) acrylic acid alkoxyalkyl esters such as (meth) acrylic acid methoxyethyl and (meth) (Meth) acrylic acid esters having a non-crosslinkable tertiary amino group such as (meth) acrylic acid, N, N-dimethylaminoethyl (meth) acrylate and N, N-dimethylaminopropyl (meth) acrylate, vinyl acetate and styrene have. These may be used alone or in combination of two or more.

The polymerization of the (meth) acrylic acid ester polymer (A) may be a random copolymer or a block copolymer.

The weight average molecular weight of the (meth) acrylic acid ester polymer (A) is preferably from 200,000 to 120,000, particularly preferably from 300,000 to 900,000, further preferably from 400,000 to 700,000. The weight average molecular weight in the present specification is a value in terms of polystyrene measured by gel permeation chromatography (GPC).

Since the weight average molecular weight of the (meth) acrylic acid ester polymer (A) is within a relatively low range as described above, a pressure sensitive adhesive excellent in both blister resistance and stepwise followability can be obtained. If the weight average molecular weight of the (meth) acrylic ester polymer (A) is less than 200,000, the blister resistance may deteriorate. When the weight average molecular weight of the (meth) acrylic acid ester polymer (A) There is a possibility that it will deteriorate.

In the sticky composition (P), the (meth) acrylic acid ester polymer (A) may be used singly or in combination of two or more.

(2) Abies acid ester-based adhesive liquid (B)

In the present embodiment, the abietic acid ester-based adhesive liquid (B) is an abietic acid ester having a melting point of 20 캜 or lower. As a result, the abietic acid ester-based adhesive liquid (B) becomes liquid at room temperature, and the adhesion improving effect based on the above-mentioned action of improving the wettability and the interaction with the reactive functional group of the (meth) acrylic acid ester polymer As a result, excellent blister resistance is achieved. From this viewpoint, it is preferable that the melting point of the abietic acid ester-based adhesive liquid (B) is 0 DEG C or lower.

For example, "Fine Crystal ME-G" (trade name) manufactured by Arakawa Chemical Industry Co., Ltd. and the like can be used as the abietic acid ester-based adhesive liquid (B) having the melting point as described above. Further, the abietic acid ester-based adhesive liquid (B) may be used singly or in combination of two or more kinds.

The content of the abietic acid ester-based adhesive liquid (B) in the viscous composition (P) is preferably 5 to 25 parts by mass, more preferably 7 to 20 parts by mass based on 100 parts by mass of the (meth) acrylic acid ester polymer (A) 20 parts by mass, and more preferably 10 to 15 parts by mass. When the content of the abietic acid ester-based adhesive liquid (B) is 5 parts by mass or more, the above-mentioned adhesiveness improving effect is exhibited, and the resultant pressure-sensitive adhesive has excellent blister resistance. When the content of the abietic acid ester-based adhesive liquid (B) is 25 parts by mass or less, the cohesive force of the obtained pressure sensitive adhesive is preferable, and the obtained pressure sensitive adhesive has durability.

(3) Crosslinking agent (C)

The sticky composition (P) preferably further contains a cross-linking agent (C). When the sticky composition (P) is heated, the cross-linking agent (C) reacts with the reactive functional group of the (meth) acrylic acid ester polymer (A). As a result, the (meth) acrylic acid ester polymer (A) is crosslinked by the crosslinking agent (C), and the resulting pressure sensitive adhesive exhibits improved cohesion and better blister resistance.

The crosslinking agent (C) is not particularly limited as long as it can react with the reactive functional group possessed by the (meth) acrylic acid ester polymer (A). Examples thereof include isocyanate crosslinking agents, epoxy crosslinking agents, amine crosslinking agents, melamine crosslinking agents, aziridine crosslinking agents, Based crosslinking agent, an aldehyde-based crosslinking agent, an oxazoline-based crosslinking agent, a metal alkoxide-based crosslinking agent, a metal chelating-type crosslinking agent, a metal salt-based crosslinking agent, and an ammonium salt-based crosslinking agent. When the reactive functional group contained in the (meth) acrylic acid ester polymer (A) is a hydroxyl group, it is preferable to use an isocyanate-based crosslinking agent having excellent reactivity with the hydroxyl group. When the reactive functional group of the (meth) acrylic acid ester polymer (A) , It is preferable to use an epoxy crosslinking agent having excellent reactivity with a carboxyl group. The crosslinking agent (C) may be used singly or in combination of two or more.

The isocyanate-based crosslinking agent contains at least a polyisocyanate compound. Examples of the polyisocyanate compound include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate and xylylene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane Alicyclic polyisocyanates such as diisocyanate and the like, and reaction products thereof with low-molecular active hydrogen-containing compounds such as burette, isocyanurate, and furthermore, ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, And duct bodies. Among them, trimethylolpropane-modified aromatic polyisocyanates, especially trimethylolpropane-modified tolylene diisocyanate and trimethylolpropane-modified xylylene diisocyanate are preferable from the viewpoint of reactivity with hydroxyl groups.

Examples of the epoxy crosslinking agent include 1,3-bis (N, N'-diglycidylaminomethyl) cyclohexane, N, N, N ', N'-tetraglycidyl-m- Diamine, ethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylol propane diglycidyl ether, diglycidyl aniline, diglycidyl amine, and the like.

The content of the crosslinking agent (C) in the adhesive composition (P) is preferably 0.001 to 10 parts by mass, more preferably 0.01 to 5 parts by mass, per 100 parts by mass of the (meth) acrylic acid ester polymer (A) Is preferably 0.02 to 1 part by mass.

When the content of the crosslinking agent (C) is in the above-mentioned range, the blister resistance can be improved without impairing the stepwise followability of the obtained pressure-sensitive adhesive.

(4) Various additives

To the sticky composition (P), various additives commonly used in acrylic pressure sensitive adhesives such as a silane coupling agent, a refractive index adjusting agent, an antistatic agent, a tackifier, an antioxidant, a UV absorbent, a light stabilizer, a softener, Can be added.

(5) Production of sticky composition

The sticky composition (P) is obtained by preparing a (meth) acrylic acid ester polymer (A) and then adding the resulting (meth) acrylic acid ester polymer (A) to the obtained abietic acid ester-based adhesive liquid (B) C) and an additive.

The (meth) acrylic acid ester polymer (A) can be produced by polymerizing a mixture of monomer units constituting the polymer by a conventional radical polymerization method. The polymerization of the (meth) acrylic acid ester polymer (A) is preferably carried out by a solution polymerization method or the like using a polymerization initiator as desired. As the polymerization solvent, for example, ethyl acetate, n-butyl acetate, isobutyl acetate, toluene, acetone, hexane, methyl ethyl ketone and the like may be used.

Examples of the polymerization initiator include an azo compound, an organic peroxide, and the like, and two or more of them may be used in combination. Examples of the azo compound include azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 1,1'-azobis (cyclohexane- (2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethyl-4-methoxy valeronitrile), dimethyl 2,2 ' Azobis (2-methylpropionate), 4,4'-azobis (4-cyanovaleric acid), 2,2'-azobis (2-hydroxymethylpropionitrile) -Azobis [2- (2-imidazolin-2-yl) propane].

Examples of the organic peroxide include organic peroxides such as benzoyl peroxide, t-butyl perbenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di (2-ethoxyethyl) Carbonate, t-butyl peroxyneodecanoate, t-butyl peroxypivalate, (3,5,5-trimethylhexanoyl) peroxide, dipropionyl peroxide, and diacetyl peroxide.

In addition, the weight average molecular weight of the resulting polymer can be controlled by blending a chain transfer agent such as 2-mercaptoethanol in the polymerization step.

(B) and, if desired, a cross-linking agent (C), an additive and a diluent (B) are added to the solution of the (meth) acrylic acid ester polymer (A) A solvent is added and sufficiently mixed to obtain a sticky composition (P) (coating solution) diluted with a solvent.

Examples of the diluting agent include aliphatic hydrocarbons such as hexane, heptane and cyclohexane, aromatic hydrocarbons such as toluene and xylene, halogenated hydrocarbons such as methylene chloride and ethylene chloride, alcohols such as methanol, ethanol, propanol, Propanol, and the like; ketones such as acetone, methyl ethyl ketone, 2-pentanone, isophorone, and cyclohexanone; esters such as ethyl acetate and butyl acetate; and cellosolve solvents such as ethyl cellosolve Etc. are used.

The concentration and viscosity of the coating solution thus prepared are not particularly limited and may be suitably selected according to the circumstances. For example, it is diluted such that the concentration of the sticky composition (P) is 10 to 60% by mass. Addition of a diluting solvent or the like is not a necessary condition for obtaining a coating solution, and it is not necessary to add a diluting solvent if the viscosity of the adhesive composition (P) is such that it can be coated. In this case, the adhesive composition (P) becomes a coating solution containing the polymerization solvent of the (meth) acrylic acid ester polymer (A) as it is as a diluent solvent.

(6) Production of pressure-sensitive adhesive

The pressure-sensitive adhesive relating to the present embodiment is obtained by crosslinking the pressure-sensitive adhesive composition (P). The crosslinking of the adhesive composition (P) can be usually carried out by heat treatment. The heat treatment may also be performed by a drying treatment to volatilize a diluting solvent or the like of the adhesive composition (P).

When the heat treatment is carried out, the heating temperature is preferably 50 to 150 占 폚, particularly preferably 70 to 120 占 폚. The heating time is preferably 30 seconds to 10 minutes, more preferably 50 seconds to 2 minutes. After the heat treatment, a curing period of about 1 to 2 weeks may be provided at room temperature (for example, 23 DEG C, 50% RH) as needed. If the curing period is necessary, after the curing period has elapsed, if the curing period is not necessary, the pressure-sensitive adhesive is formed after the heat treatment is finished.

By the above-mentioned heat treatment (and curing), the (meth) acrylic acid ester polymer (A) is sufficiently crosslinked to exhibit excellent blister resistance.

(7) Gel fraction

The gel fraction of the pressure-sensitive adhesive relating to the present embodiment is 30 to 95%, preferably 40 to 80%, particularly preferably 45 to 70%. If the gel fraction is less than 30%, the cohesive force of the pressure-sensitive adhesive is insufficient and the blister resistance is lowered. On the other hand, when the gel fraction exceeds 95%, the adhesive strength is excessively lowered, resulting in lowering of durability and deterioration in step-following performance. The method of measuring the gel fraction is as shown in the following test examples.

[Adhesive sheet]

1, the pressure-sensitive adhesive sheet 1 according to the present embodiment includes two peeling sheets 12a and 12b and two peeling sheets 12a and 12b in contact with the peeling surfaces of the two peeling sheets 12a and 12b, And a pressure-sensitive adhesive layer 11 sandwiched between the sheets 12a and 12b. The release surface of the release sheet in the present specification means a surface having release properties in the release sheet and includes both the surface subjected to the release treatment and the surface exhibiting the release property without performing the release treatment.

(1) Pressure-sensitive adhesive layer

The pressure-sensitive adhesive layer 11 is composed of the pressure-sensitive adhesive described above, that is, the pressure-sensitive adhesive comprising the pressure-sensitive adhesive composition (P) crosslinked.

Although the thickness of the pressure-sensitive adhesive layer 11 (measured according to JIS K 7130) varies depending on the height of the level difference, it is preferably 10 to 400 占 퐉, more preferably 20 to 300 占 퐉, Mu] m. When the thickness of the pressure-sensitive adhesive layer 11 is 10 占 퐉 or more, good step traceability is exhibited, and the thickness of the pressure-sensitive adhesive layer 11 is 400 占 퐉 or less. Further, the pressure-sensitive adhesive layer 11 may be formed as a single layer, or a plurality of layers may be laminated.

(2) Peeling sheet

The release sheets 12a and 12b are not particularly limited, and a known plastic film can be used. Examples of the film include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polyethylene naphthalate film, polybutylene terephthalate (Meth) acrylic acid copolymer film, an ethylene / (meth) acrylic acid ester copolymer film, a polystyrene film, a polycarbonate film, a polyimide film, a fluororesin Film or the like is used. These crosslinked films are also used. These films may be laminated films.

It is preferable that the release surface of the release sheets 12a and 12b (particularly, the surface in contact with the pressure-sensitive adhesive layer 11) is subjected to a release treatment. As the releasing agent used in the peeling treatment, for example, an alkyd type, a silicone type, a fluorine type, an unsaturated polyester type, a polyolefin type, and a wax type releasing agent may be mentioned. It is also preferable that one of the release sheets 12a and 12b is a heavy release type release sheet having a large release force and the other release sheet is a light release type release sheet having a small release force.

The thickness of the release sheets 12a, 12b is not particularly limited, but is usually about 20 to 150 mu m.

(3) Production of pressure-sensitive adhesive sheet

In one production example of the adhesive sheet 1, the application liquid of the adhesive composition (P) is applied to the release surface of one of the release sheets 12a (or 12b) And the release layer of the other release sheet 12b (or 12a) is superimposed on the release layer. When a curing period is required, a curing period is provided, and when the curing period is unnecessary, the applied layer becomes the pressure-sensitive adhesive layer (11). Thus, the pressure-sensitive adhesive sheet (1) is obtained. The conditions of the heat treatment and curing are as described above.

In another production example of the adhesive sheet 1, the application liquid of the adhesive composition (P) is applied to the release surface of one release sheet (12a) and heat treatment is performed to crosslink the adhesive composition (P) A release layer is formed to obtain a release sheet 12a on which a coating layer is formed. The application liquid of the adhesive composition (P) is applied to the release surface of the other release sheet (12b), and the adhesive composition (P) is crosslinked by heat treatment to form a coating layer, So that the release sheet 12b is obtained. Then, the release sheet 12a on which the application layer is formed and the release sheet 12b on which the application layer is formed are bonded so that the both application layers come into contact with each other. When the curing period is required, the curing period is provided, and when the curing period is unnecessary, the laminated coating layer becomes the pressure-sensitive adhesive layer (11). Thus, the pressure-sensitive adhesive sheet (1) is obtained. According to this production example, even when the pressure-sensitive adhesive layer 11 is thick, it can be stably produced.

As a method of applying the coating liquid of the adhesive composition (P), for example, a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, a gravure coating method and the like can be used.

(4) Hayes

The pressure-sensitive adhesive layer 11 in the present embodiment preferably has a haze value (value measured according to JIS K 7136: 2000) of 3% or less, more preferably 2% or less, further preferably 1% or less Do. When the haze value is 3% or less, the transparency is very high, which is preferable for optical use.

(5) Total light transmittance

The pressure-sensitive adhesive layer 11 in the present embodiment preferably has a total light transmittance (value measured according to JIS K 7105: 1981) of 90% or more, more preferably 95% or more, further preferably 98% Do. When the total light transmittance is 98% or more, transparency is very high, which is preferable for optical use.

(6) Use of adhesive sheet

By using the pressure-sensitive adhesive sheet 1, for example, the touch panel 2 of the capacitance type shown in Fig. 2 can be manufactured. The touch panel 2 includes a display element module 3, a first film sensor 5a laminated thereon with a pressure sensitive adhesive layer 4a interposed therebetween, and a second film sensor 5b laminated thereon with a pressure sensitive adhesive layer 4b interposed therebetween A second film sensor 5b, and a cover material 6 laminated thereon with a pressure-sensitive adhesive layer 11 interposed therebetween.

The pressure sensitive adhesive layer 11 in the touch panel 2 is the pressure sensitive adhesive layer 11 of the pressure sensitive adhesive sheet 1.

Examples of the display module 3 include a liquid crystal (LCD) module, a light emitting diode (LED) module, an organic electroluminescence (organic EL) module, and an electronic paper.

The pressure-sensitive adhesive layers 4a and 4b may be formed of the pressure-sensitive adhesive layer 11 of the pressure-sensitive adhesive sheet 1, or may be formed of another pressure-sensitive adhesive or pressure-sensitive adhesive sheet. In the latter case, examples of the pressure sensitive adhesive constituting the pressure sensitive adhesive layer 4 include an acrylic pressure sensitive adhesive, a rubber pressure sensitive adhesive, a silicone pressure sensitive adhesive, a urethane pressure sensitive adhesive, a polyester pressure sensitive adhesive and a polyvinyl ether pressure sensitive adhesive. Do.

The first film sensor 5a and the second film sensor 5b are generally composed of a base film 51 and a patterned transparent conductive film 52, respectively. The base film 51 is not particularly limited, and for example, a polyethylene terephthalate film, an acrylic film, a polycarbonate film, or the like is used.

As the transparent conductive film 52, for example, a metal such as platinum, gold, silver or copper, an oxide such as tin oxide, indium oxide, cadmium oxide, zinc oxide or zinc dioxide, indium tin oxide (ITO) A non-oxidizing compound such as zinc oxide, zinc oxide, indium oxide, indium oxide, indium fluoride, indium oxide, antimony doped tin oxide, fluorine doped tin oxide or aluminum oxide doped with zinc oxide, chalcogenide, lanthanum hexafluoride, Among them, it is preferable to be made of tin-doped indium oxide (ITO).

The transparent conductive film 52 of the first film sensor 5a and the transparent conductive film 52 of the second film sensor 5b usually constitute a circuit pattern in the X axis direction and the other of them forms the Y axis direction Thereby constituting a circuit pattern.

The transparent conductive film 52 of the second film sensor 5b in this embodiment is located on the upper side of the second film sensor 5b in Fig. 2, but the present invention is not limited to this, (5b). The transparent conductive film 52 of the first film sensor 5a is located on the upper side of the first film sensor 5a in Fig. 2, but the present invention is not limited thereto. It may be located on the lower side.

The cover member 6 is usually made of a glass plate or a plastic plate. The glass plate is not particularly limited, and examples of the glass plate include chemical-tempered glass, alkali-free glass, quartz glass, soda lime glass, barium-strontium glass, aluminosilicate glass, lead glass, borosilicate glass, barium borosilicate glass, . The plastic plate is not particularly limited, and examples thereof include an acrylic plate and a polycarbonate plate made of polymethyl methacrylate or the like.

In addition, functional layers such as a hard coat layer, an antireflection layer, and an antiglare layer may be formed on one side or both sides of the glass plate or the plastic plate, or an optical member such as a hard coat film, an antireflection film and an antiglare film may be laminated do.

In the present embodiment, the cover material 6 has a step on the side of the pressure-sensitive adhesive layer 11, specifically, a step due to the presence or absence of the print layer 7. [ The print layer 7 is generally formed in a frame shape on the side of the pressure-sensitive adhesive layer 11 in the cover material 6.

The material constituting the print layer 7 is not particularly limited, and known materials for printing are used. The thickness of the printing layer 7, that is, the height of the step is preferably 3 to 45 占 퐉, more preferably 5 to 35 占 퐉, particularly preferably 7 to 25 占 퐉, and even more preferably 7 to 15 占 퐉 .

The thickness (step height) of the print layer 7 is preferably 3 to 30%, more preferably 3.2 to 20%, and further preferably 3.5 to 15% of the thickness of the pressure-sensitive adhesive layer 11 . As a result, the pressure-sensitive adhesive layer 11 is easy to follow the stepped portion by the printed layer 7, and the occurrence of lifting, bubbling, or the like in the vicinity of the stepped portion is suppressed.

An example of a method of manufacturing the touch panel 2 will be described below.

One of the release sheets 12a is peeled from the pressure sensitive adhesive sheet 1 and the exposed pressure sensitive adhesive layer 11 is brought into contact with the patterned transparent conductive film 52 of the second film sensor 5b, (5b). On the other hand, the pressure sensitive adhesive layer 4b formed on the release sheet is bonded to the first film sensor 5a so as to be in contact with the patterned transparent conductive film 52 of the first film sensor 5a.

The peeling film remaining on the pressure-sensitive adhesive layer 4b is peeled off and the exposed pressure-sensitive adhesive layer 4b is peeled off from the side opposite to the side where the pressure-sensitive adhesive layer 11 of the second film sensor 5b is laminated (The exposed surface of the base film 51 of the second film sensor 5b). Thereby, a laminate comprising a release sheet 12b, a pressure-sensitive adhesive layer 11, a second film sensor 5b, a pressure-sensitive adhesive layer 4b and a first film sensor 5a successively laminated is obtained.

Next, the pressure-sensitive adhesive layer 4a formed on the release sheet is applied to the surface of the laminate on the side of the first film sensor 5a (the exposed surface of the base film 51 of the first film sensor 5a) . Subsequently, the other release sheet 12b is peeled off from the laminate, and the exposed portion of the pressure-sensitive adhesive layer 11 is brought into contact with the pressure-sensitive adhesive layer 11 on the side of the print layer 7 of the cover material 6 And the cover material 6 is bonded. As a result, the cover member 6, the pressure sensitive adhesive layer 11, the second film sensor 5b, the pressure sensitive adhesive layer 4b, the first film sensor 5a, the pressure sensitive adhesive layer 4a, Is obtained.

Finally, the release sheet is peeled off from the constituent body, and the constituent body is attached to the display module 3 so that the exposed pressure-sensitive adhesive layer 4a contacts the display module 3. Thus, the touch panel 2 shown in Fig. 2 is manufactured.

The pressure sensitive adhesive layer 11 has excellent step traceability when the pressure sensitive adhesive layer 11 and the cover material 6 are bonded to each other in the above step so that the gap between the stepped portion by the print layer 7 and the pressure sensitive adhesive layer 11 The pores are not easily formed, and the pressure-sensitive adhesive layer 11 can fill the step. Also, even when the touch panel 2 is placed under the high-temperature and high-humidity conditions, bubbling, lifting, peeling, and the like are prevented from occurring near the step.

In the case where the cover material 6 is a plastic plate, even if outgas is generated from the plastic plate under high temperature and high humidity conditions, the pressure-sensitive adhesive layer 11 has excellent blister resistance, The occurrence of blisters, such as < / RTI >

Since the pressure-sensitive adhesive layer 11 is excellent in anti-wet heat and whitening property, whitening is suppressed when the touch panel 2 is returned to a normal temperature after putting the touch panel 2 in a high temperature and high humidity condition.

The above-described embodiments are described for the purpose of facilitating understanding of the present invention and are not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design modifications and equivalents falling within the technical scope of the present invention.

For example, either one of the release sheets 12a and 12b in the adhesive sheet 1 may be omitted.

Example

Hereinafter, the present invention will be described in more detail with reference to Examples and the like, but the scope of the present invention is not limited to these Examples and the like.

[Example 1]

1. Preparation of (meth) acrylic acid ester polymer

60 parts by mass of 2-ethylhexyl acrylate, 20 parts by mass of methyl methacrylate and 20 parts by mass of 2-hydroxyethyl acrylate were copolymerized to prepare a (meth) acrylic acid ester polymer (A). The molecular weight of the (meth) acrylic acid ester polymer (A) was measured by a method described later, and as a result, the weight average molecular weight (Mw) was 60,000.

2. Preparation of adhesive composition

100 parts by mass of the (meth) acrylic acid ester polymer (A) obtained in the above step (1) (in terms of solid content; hereinafter the same) and abietic acid as the abietic acid ester- 10 parts by mass of an ester compound (Fine Crystal ME-G, product of Arakawa Chemical Industries, Ltd.) and 0.25 parts by mass of a tolylene diisocyanate compound (trade name: BHS8515, manufactured by Toyochem Co., Ltd.) as a crosslinking agent (C) And diluted with methyl ethyl ketone to obtain a coating solution of a sticky composition having a solid content concentration of 36 mass%.

Table 1 shows the composition of the adhesive composition. Details of the abbreviations, etc. shown in Table 1 are as follows.

[(Meth) acrylic acid ester polymer (A)]

2EHA: 2-ethylhexyl acrylate

MMA: methyl methacrylate

HEA: 2-hydroxyethyl acrylate

BA: n-butyl acrylate

AA: Acrylic acid

MA: methyl acrylate

[Crosslinking agent (C)]

Isocyanate-based: tolylene diisocyanate-based compound (product name: " BHS8515 "

Epoxy system: 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane (product name: TC-5, manufactured by Taisei Pharmaceutical Co., Ltd.)

3. Production of adhesive sheet

The coating solution of the obtained sticky composition was applied to a release treatment surface of a heavy-duty release sheet (product name: "SP-PET752150" manufactured by LINTEC CO., LTD.) In which one surface of a polyethylene terephthalate film was subjected to release treatment with a silicone- Coated with a coater, and then heat-treated at 90 캜 for 1 minute to form a coated layer. Similarly, a coating solution of the obtained sticky composition was applied to the release treatment surface of a lightly receding type release sheet (trade name: SP-PET382120, manufactured by LINTEC CO., LTD.) In which one surface of a polyethylene terephthalate film was subjected to release treatment with a silicone- By a knife coater, and then heat-treated at 90 DEG C for 1 minute to form a coated layer.

Next, a heavy-duty releasing sheet having the above-obtained coating layer formed thereon and a lightly curved releasing sheet having the coating layer obtained as described above were cemented so as to be in contact with each other and cured for 7 days under conditions of 23 캜 and 50% RH Sensitive adhesive layer (thickness: 50 占 퐉) / light-weight recyclable release sheet. The thickness of the pressure-sensitive adhesive layer is a value measured using a constant pressure thickness gauge (product name: " PG-02 " manufactured by Teclock Co., Ltd.) in accordance with JIS K 7130.

[Examples 2 to 3, Comparative Examples 1 to 4]

The ratio of each monomer constituting the (meth) acrylic acid ester polymer (A), the weight average molecular weight (Mw) of the (meth) acrylic acid ester polymer (A), the kind and amount of the tackifier, A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1, except that the blending amount was changed as shown in Table 1.

The weight average molecular weight (Mw) described above is a weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC) under the following conditions (GPC measurement).

<Measurement Conditions>

· GPC measuring apparatus: HLC-8020 manufactured by Tosoh Corporation

· GPC column (pass in the following order): Tosa

 TSK guard column HXL-H

 TSK gel GMHXL (× 2)

 TSK gel G2000HXL

Measurement solvent: tetrahydrofuran

· Measuring temperature: 40 ℃

[Test Example 1] (Measurement of gel fraction)

The pressure-sensitive adhesive sheet obtained in Examples and Comparative Examples was cut into a size of 80 mm x 80 mm, the pressure-sensitive adhesive layer was wrapped in a mesh made of polyester (mesh size 200), the mass thereof was weighed with a precision balance, The mass of the adhesive alone was calculated by subtracting the mass. The mass at this time is denoted by M1.

Next, the pressure-sensitive adhesive wrapped in the polyester mesh was immersed in ethyl acetate at room temperature (23 DEG C) for 24 hours. Then, the pressure-sensitive adhesive was taken out and air-dried for 24 hours under an environment of a temperature of 23 DEG C and a relative humidity of 50%, and then dried in an oven at 80 DEG C for 12 hours. After drying, the mass was weighed with a precision balance, and the mass of the adhesive alone was calculated by subtracting the mass of the mesh alone. The mass at this time is M2. The gel fraction (%) is expressed by (M2 / M1) x100. The results are shown in Table 2.

[Test Example 2] (Blister resistance evaluation)

The pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet obtained in Examples and Comparative Examples was changed to a transparent conductive film of a polyethylene terephthalate film (ITO film, thickness: 125 μm, manufactured by OIKE INDUSTRIAL CO., LTD.) Having a transparent conductive film formed of indium tin oxide Film was sandwiched between an acrylic plate made of polymethylmethacrylate (PMMA) (manufactured by Mitsubishi Gas Chemical Co., Ltd., U.Philon sheet MR200, thickness: 1 mm) to obtain a laminate.

The obtained laminate was subjected to autoclave treatment at 50 캜 under 0.5 MPa for 30 minutes and then left at normal pressure, 23 캜, and 50% RH for 24 hours. Then, it was stored for 72 hours under the conditions of 85 DEG C and 85% RH. Thereafter, whether the pressure-sensitive adhesive layer was free from bubbles, lifting or peeling was visually confirmed, and the blister resistance was evaluated by the following criteria. The results are shown in Table 2.

◎ ... There was no bubble, lifting and peeling.

○ ... Only air bubbles having a diameter of 0.1 mm or less were generated.

× ... Bubbles exceeding 0.1 mm in diameter, lifting or peeling occurred.

[Test Example 3] (Step following property evaluation)

(a) Preparation of sample for evaluation

POS-911 black (trade name, manufactured by Teikoku Ink Kabushiki Kaisha) was coated on the surface of a glass plate (manufactured by NSG Precision, product name: Corning Glass Eagle XG, length 90 mm x width 50 mm x thickness 0.5 mm) ) Was screen-printed in a frame shape (outer shape: length 90 mm × width 50 mm, width 5 mm) such that the coating thickness was any one of 5 μm, 10 μm, 15 μm and 20 μm. Subsequently, the printed ultraviolet curable ink was cured by irradiating ultraviolet rays (80 W / cm 2, a metal halide lamp 2 lamp, lamp height 15 cm, belt speed 10 to 15 m / min) Height: 5 mu m, 10 mu m, 15 mu m, and 20 mu m).

The lightly peelable release sheet was peeled off from the pressure-sensitive adhesive sheet obtained in the examples and the comparative example and the exposed pressure-sensitive adhesive layer was bonded to a layer for easy adhesion of a polyethylene terephthalate film (Toyobo Co., Ltd., PET A4300, thickness: Respectively. Subsequently, the heavy-duty release sheet was peeled off to expose the pressure-sensitive adhesive layer. The laminate was laminated on each stepped glass plate so that the pressure-sensitive adhesive layer covers the entire printed surface in the form of a frame by using a laminator (product of Fuji Plastic Co., Ltd., product name "LPD3214").

(b) Evaluation of sample for evaluation

The obtained evaluation sample was subjected to autoclave treatment at 50 캜 under 0.5 MPa for 30 minutes and then left at normal pressure, 23 캜, and 50% RH for 24 hours. Subsequently, the sample was stored under a moist heat condition of 85 ° C and 85% RH for 72 hours, and then the step traceability was evaluated. It is judged that the step following property can not follow the printed step difference when a gap or bubble is observed at the interface between the printed step and the pressure-sensitive adhesive layer, by judging whether or not the printed step is completely filled with the pressure-sensitive adhesive layer. Herein, the step following ability was evaluated as a step following rate (%) according to the following criteria. The results are shown in Table 2.

(%) = {(Height of printed steps without gap or bubble (占 퐉) / (thickness of pressure-sensitive adhesive layer: 50 占 퐉)) 占 100

◎: Step following rate 40%

○: Step-to-step follow-up rate 10% to 30%

X: Less than 10% follow-up rate

[Test Example 4] (Measurement of optical properties)

Sensitive adhesive layer of the pressure-sensitive adhesive sheet obtained in Examples and Comparative Examples was evaluated for haze value (%) and total light ray (%) using a haze meter (product name: "NDH-2000" manufactured by Nippon Denshoku Industries Co., Ltd.) according to JIS K 7361-1: 1997 The transmittance (%) was measured. The results are shown in Table 2.

As can be seen from Table 2, the pressure-sensitive adhesive sheet obtained in Examples had excellent step traceability and blister resistance, and had good optical characteristics.

Industrial availability

The pressure-sensitive adhesive and the pressure-sensitive adhesive sheet according to the present invention can be suitably used, for example, for bonding a cover material having a step to a display body module in a touch panel, in particular, a plastic plate.

One … Adhesive sheet
11 ... The pressure-
12a, 12b ... Peeling sheet
2 … Touch panel
3 ... Display module
4a, 4b ... The pressure-
5a ... The first film sensor
5b ... The second film sensor
51 ... Base film
52 ... Transparent conductive film
6 ... Cover material
7 ... Printing layer

Claims (7)

A sticky composition containing a (meth) acrylic acid ester polymer (A) containing 8 to 30 mass% of a monomer having a reactive functional group and an abietic acid ester-based adhesive liquid (B) as monomer units constituting the polymer A pressure-sensitive adhesive comprising a cross-linked adhesive, wherein the gel fraction is 30 to 95%. The pressure-sensitive adhesive according to claim 1, wherein the (meth) acrylic acid ester polymer (A) contains a hard monomer having a glass transition temperature of 70 占 폚 or higher as a homopolymer as a monomer unit constituting the polymer. 3. The pressure-sensitive adhesive according to claim 1 or 2, wherein the (meth) acrylic acid ester polymer (A) contains 2-ethylhexyl (meth) acrylate as a monomer unit constituting the polymer. The pressure-sensitive adhesive according to any one of claims 1 to 3, wherein the (meth) acrylic acid ester polymer (A) has a weight average molecular weight of 200,000 to 120,000. The pressure-sensitive adhesive according to any one of claims 1 to 4, wherein the pressure-sensitive adhesive composition further comprises a cross-linking agent (C). And a pressure-sensitive adhesive layer sandwiched between the release sheets so as to come into contact with the release surfaces of the two release sheets, wherein the pressure-sensitive adhesive layer comprises the pressure-sensitive adhesive according to any one of claims 1 to 5 Wherein the pressure-sensitive adhesive sheet is a pressure-sensitive adhesive sheet. The pressure-sensitive adhesive sheet according to claim 6, wherein the pressure-sensitive adhesive layer is disposed between the two patterned transparent conductive films, or between the patterned transparent conductive film and the cover material or the display module.

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