TWI805861B - Adhesive composition, adhesive agent, adhesive sheet and display body - Google Patents

Abstract

（在化學式中，R¹ 係可以具有氮原子的2價烴基。在化學式中，R² ～R⁷ 係各自獨立地為烷基。）Problem: To provide an adhesive composition, an adhesive, an adhesive sheet, and a display body capable of suppressing changes in the resistance value of electrodes. Solution: an adhesive composition comprising: (meth)acrylate polymer (A); and a silane coupling agent (B) having alkoxysilyl groups at both ends. Preferably, the silane coupling agent (B) is a compound represented by the following general formula (I).

(In the chemical formula, R ¹ is a divalent hydrocarbon group that may have a nitrogen atom. In the chemical formula, R ² to R ⁷ are each independently an alkyl group.)

Description

Adhesive composition, adhesive agent, adhesive sheet and display body

The present invention relates to an adhesive composition, an adhesive, and an adhesive sheet that can be used for displays such as touch panels, and a display using the adhesive composition, adhesive, and adhesive sheet.

In recent years, in various mobile electronic devices such as smart phones and tablet devices, a large number of touch panels have been used as displays. Touch panel technologies include resistive film type, capacitive type, etc., and in the above-mentioned mobile electronic devices, capacitive type is mainly used.

Usually, a transparent conductive film made of a metal oxide such as indium tin oxide (ITO) is used as an electrode for a touch panel. Recently, it has been proposed to use a metal electrode made of a mesh-shaped metal wiring, such as a silver electrode. However, when conventional adhesives are used in contact with the electrodes as described above, the electrodes may be corroded and the resistance value may change due to the passage of time or high-temperature and high-humidity environments, resulting in poor drive of the touch panel. .

Therefore, Patent Document 1 discloses an adhesive film for polarizing plates, which is composed of an adhesive composition for polarizing plates containing a non-carboxylic acid (meth)acrylic copolymer, an isocyanate hardening agent, and an epoxy hardening agent. In Patent Document 1, by using a non-carboxylic acid (meth)acrylic copolymer to lower the acid value, it was found that there is an effect of inhibiting corrosion, and an attempt was made to reduce the rate of change of the resistance value. [Prior art literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 2017-031406

[Problem to be solved by the invention]

However, only by using a non-carboxylic acid (meth)acrylic copolymer as described in Patent Document 1, it is difficult to suppress a change in resistance value under severe durability conditions.

The present invention was made in view of the above circumstances, and an object of the present invention is to provide an adhesive composition, an adhesive, an adhesive sheet, and a display body capable of suppressing changes in the resistance value of electrodes. [means used to solve a problem]

In order to achieve the above object, firstly, the present invention provides an adhesive composition, comprising: (meth)acrylate polymer (A); and a silane coupling agent (B) having alkoxysilyl groups at both ends ( Invention 1).

When the adhesive obtained by the adhesive composition according to the above-mentioned invention (Invention 1) is used in contact with an electrode composed of a metal or a metal oxide, even under durable conditions (for example, at 85°C 85 %RH humidity environment or after 1000 hours of durability conditions in a high temperature environment of 95°C) can suppress the resistance of electrodes made of metal (especially silver wiring) or metal oxide (especially ITO thin film) value changes.

（在化學式中，R¹ 係可以具有氮原子的2價烴基。在化學式中，R² ～R⁷ 係各自獨立地為烷基。）In the above invention (Invention 1), it is preferable that the silane coupling agent (B) is a compound represented by the following general formula (I) (Invention 2). [chemical formula 1]

(In the chemical formula, R ¹ is a divalent hydrocarbon group that may have a nitrogen atom. In the chemical formula, R ² to R ⁷ are each independently an alkyl group.)

In the above-mentioned invention (invention 2), it is preferable (invention 3) that ^R in the aforementioned general formula (I) is an alkylene group (alkylene) containing 1 to 10 carbon atoms.

In the above inventions (Inventions 2 and 3), it is preferred that ^R in the aforementioned general formula (I) is a divalent hydrocarbon group without a sulfur atom on the main chain (Invention 4).

In the above inventions (Inventions 1 to 4), it is preferable to include a crosslinking agent (C) (Invention 5).

In the above inventions (Inventions 1 to 5), it is preferable that the (meth)acrylate polymer (A) does not contain a carboxyl group-containing monomer as a monomer unit constituting the polymer (Invention 6).

In the above inventions (Inventions 1 to 6), the (meth)acrylate polymer (A) contains 6% by mass to 35% by mass of a hydroxyl group-containing monomer as a monomer unit constituting the polymer. Good (Invention 7).

Among the above inventions (Inventions 1 to 7), it is preferable to use an adhesive composition for forming an adhesive contacting an electrode made of a metal or a metal oxide (Invention 8).

Second, the present invention provides an adhesive (Invention 9) obtained by crosslinking the aforementioned adhesive composition (Inventions 1 to 8).

Thirdly, the present invention provides an adhesive sheet comprising two release sheets and an adhesive layer interposed between the release sheets in such a manner as to contact the release surfaces of the two release sheets, wherein the adhesive layer is formed by the adhesive agent (Invention 9) constituted (Invention 10).

Fourth, the present invention provides a display body, which includes a first display body structural part, a second display body structural part, and a bonding device for bonding the aforementioned first display body structural part and the aforementioned second display body structural part. A display with an adhesive layer, wherein the first display structural member and/or the second display structural member have electrodes made of metal or metal oxide on at least the surface of the bonding side, and wherein the adhesive An adhesive layer (Invention 11) layered on the above-mentioned adhesive sheet (Invention 10). [Effect of the present invention]

According to the adhesive composition, adhesive agent, adhesive sheet, and display body of the present invention, changes in the resistance value of electrodes can be suppressed.

Embodiments of the present invention will be described below. [adhesive composition] The adhesive composition (hereinafter sometimes referred to as "adhesive composition P") according to the present embodiment contains a (meth)acrylate polymer (A) and a silane dioxide having alkoxysilyl groups at both terminals. mixture (B), and preferably further contain a crosslinking agent (C). In this specification, (meth)acrylic acid means both acrylic acid and methacrylic acid. The same applies to other similar expressions. Furthermore, "polymer" also includes the concept of "copolymer".

The adhesive composition P according to this embodiment is preferably used to form an adhesive for contacting an electrode made of a metal or a metal oxide. Adhesive composition P can be used even under durable conditions (for example, in 85°C 85%RH humidity environment or after 1000 hours of durability conditions at 95°C high temperature environment) can also suppress the formation of metal (especially silver wiring) or metal oxide (especially ITO film) Changes in the resistance value of the electrodes. Therefore, if the above-mentioned electrodes are electrodes of a touch panel, the reliability of the touch panel can be improved. The above effects are considered to be mainly due to the alkoxysilyl groups present at both ends of the silane coupling agent (B) functioning to prevent moisture from entering adjacent electrodes.

Furthermore, since the alkoxysilyl groups existing at both ends of the above-mentioned silane coupling agent (B) function, the obtained adhesive becomes highly hydrophilic. It can be inferred that this highly hydrophilic adhesive, even if it is placed in a high-temperature and high-humidity environment, the moisture that enters the adhesive when it is in a high-temperature and high-humidity environment becomes easy to dissipate from the adhesive when it returns to normal temperature and normal humidity. As a result, whitening of the adhesive can be suppressed. Therefore, the adhesive obtained by crosslinking the adhesive composition P according to this embodiment also has excellent heat-and-moisture whitening resistance.

Furthermore, the above-mentioned silane coupling agent (B) will not adversely affect the (meth)acrylate polymer (A) and its crosslinked product. The adhesive obtained from the adhesive composition P containing the above-mentioned silane coupling agent (B) exhibits good adhesiveness to adherends, especially glass parts. Thereby, the obtained adhesive has excellent durability, for example, even after 1,000 hours in a humid heat environment of 85°C 85%RH or in a high temperature environment of 95°C, it is possible to prevent contact between the adhesive and the adherend. Problems such as floating or peeling occur on the interface.

In addition, the adhesive obtained from the adhesive composition P according to this embodiment may be an active energy ray-curable adhesive that is cured by irradiation with active energy rays, or may be an adhesive that does not harden when irradiated with active energy rays. Active dose ray non-hardening adhesive. In the case of an active energy ray-curable adhesive, it is preferable that the adhesive composition P further contains an active energy ray-curable component (D).

(1) Ingredients (1-1) (meth)acrylate polymer (A) The (meth)acrylate polymer (A) preferably includes a reactive functional group-containing monomer having a reactive functional group in the molecule as a monomer constituting the polymer. By containing the reactive functional group-containing monomer, the reactive functional group derived from the reactive functional group-containing monomer reacts with the cross-linking agent (C) described later to form a cross-linked structure (three-dimensional network shape structure) to obtain an adhesive with predetermined cohesion.

In the (meth)acrylate polymer (A), monomers containing reactive functional groups included in the monomer units constituting the polymer include monomers having hydroxyl groups in the molecule (monomers containing hydroxyl groups) Body), monomers with carboxyl groups in the molecule (carboxyl-containing monomers), monomers with amine groups in the molecule (amine-containing monomers), etc. are preferred. These reactive functional group-containing monomers may be used alone or in combination of two or more.

Among the above reactive functional group-containing monomers, a hydroxyl-containing monomer having excellent reactivity with the crosslinking agent (C) and moisture-heat whitening resistance and having little adverse effect on electrodes is particularly preferred.

Examples of hydroxyl-containing monomers include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 2-hydroxypropyl (meth)acrylate. Hydroxyalkyl (meth)acrylates such as -hydroxybutyl, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, etc. Among them, 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate are preferable from the viewpoint of reactivity with crosslinking agents, and 2-hydroxyethyl acrylate and acrylic acid 4-Hydroxybutyl ester is preferred. These materials may be used alone or in combination of two or more.

In the (meth)acrylate polymer (A), as monomer units constituting the polymer, monomers containing reactive functional groups (especially monomers containing hydroxyl groups) preferably contain 6% by mass or more, It is especially preferable to contain 9 mass % or more, and it is more preferable to contain 12 mass % or more. Furthermore, in the (meth)acrylate polymer (A), as a monomer unit constituting the polymer, a reactive functional group-containing monomer (especially a hydroxyl-containing monomer) is contained in an amount of 35% by mass or less Preferably, it contains 30 mass % or less, and it is more preferable to contain 25 mass % or less.

When the (meth)acrylate polymer (A) includes the above-mentioned reactive functional group-containing monomer as a monomer unit, the silane coupling agent (B) tends to segregate in the obtained adhesive layer The tendency of the surface layer, the aforementioned effect of suppressing the change in resistance value becomes more excellent. Furthermore, when the (meth)acrylate polymer (A) includes the above-mentioned reactive functional group-containing monomer as a monomer unit, the obtained adhesive has a good balance between the adhesive force and the cohesive force . Further, when the (meth)acrylate polymer (A) includes 6% by mass or more of hydroxyl group-containing monomers as monomer units, a predetermined amount of hydrophilic groups remains in the obtained adhesive. The hydroxyl group. As a result, due to the synergistic effect with the silane coupling agent (B) having alkoxysilyl groups at both ends, the obtained adhesive has excellent heat-and-moisture whitening resistance.

The (meth)acrylate polymer (A) preferably does not contain a carboxyl group-containing monomer as a monomer unit constituting the polymer. The reason for this is that the carboxyl group is an acid component and usually causes a change in the resistance value of the electrode in contact with the adhesive. However, the above-mentioned "does not contain a carboxyl group-containing monomer" means that it is permissible to include a carboxyl group-containing monomer to such an extent that the electrode to which the obtained adhesive is in contact will not be adversely affected. Specifically, in the (meth)acrylate polymer (A), the content of the carboxyl group-containing monomer as a monomer unit is preferably not more than 0.1% by mass, particularly preferably not more than 0.01% by mass, and More preferably, it is 0.001 mass % or less.

Furthermore, the (meth)acrylate polymer (A) preferably includes an alkyl (meth)acrylate as a monomer unit constituting the polymer. Thereby, good adhesiveness can be expressed.

In particular, in the (meth)acrylate polymer (A), as monomer units constituting this polymer, in addition to the above-mentioned reactive functional group-containing monomers, to include glass transition temperature as a homopolymer Alkyl (meth)acrylate having a (Tg) of 0°C or lower and an alkyl group having 2 to 20 carbon atoms, and a monomer having a glass transition temperature (Tg) exceeding 0°C as a homopolymer are preferable.

The (meth)acrylate polymer (A) is obtained by including an alkyl (meth)acrylate ( Hereinafter, it may be referred to as "low Tg alkyl acrylate.") As a monomer unit constituting this polymer, it can exhibit good adhesiveness. From the above point of view, in the (meth)acrylate polymer (A), as a monomer unit constituting the polymer, the low Tg alkyl acrylate preferably contains 30% by mass or more, and preferably contains 40% by mass The above is particularly preferable, and it is more preferable to contain 50 mass % or more. Furthermore, in the (meth)acrylate polymer (A), as the monomer unit constituting the polymer, the upper limit of the above-mentioned low Tg alkyl acrylate is preferably 90% by mass or less, preferably 80% by mass. It is especially preferable to contain it by mass % or less, and it is more preferable to contain it by 70 mass % or less. When the upper limit of the content of the low-Tg alkyl acrylate is as described above, an appropriate amount of other monomer components can be added to the (meth)acrylate polymer (A).

Examples of low Tg alkyl acrylates include ethyl acrylate (Tg-20°C), n-butyl acrylate (Tg-55°C), isobutyl acrylate (Tg-26°C), n-octyl acrylate (Tg-65°C), isooctyl acrylate (Tg-58°C), 2-ethylhexyl acrylate (Tg-70°C), 2-ethylhexyl methacrylate (Tg-10°C ), isononyl acrylate (Tg-58°C), isodecyl acrylate (Tg-60°C), isodecyl methacrylate (Tg-41°C), n-dodecyl acrylate (Tg- 23°C), n-dodecyl methacrylate (Tg-65°C), tridecyl acrylate (Tg-55°C), tridecyl methacrylate (-40°C) , Isostearyl acrylate (Tg-18°C) is preferred. Among them, as the low-Tg alkyl acrylate, from the viewpoint of more efficiently imparting adhesiveness, the Tg of the homopolymer is preferably -40°C or lower, and particularly preferably -50°C or lower. Specifically, n-butyl acrylate and 2-ethylhexyl acrylate are particularly preferred. These materials may be used alone or in combination of two or more. In addition, the alkyl group in the alkyl (meth)acrylate having 2 to 20 carbon atoms in the alkyl group refers to a linear, branched or cyclic alkyl group.

Furthermore, the above-mentioned low Tg alkyl acrylate is composed of at least a part of the carbon atoms of the above-mentioned alkyl group from the viewpoint of suppressing changes in the resistance value of the electrode under durability conditions by increasing the hydrophobicity of the obtained adhesive layer. It is preferably composed of an alkyl (meth)acrylate having 5 or more carbon atoms, and at least a part thereof is preferably composed of an alkyl (meth)acrylate having 7 or more carbon atoms in the alkyl group. Specifically, 2-ethylhexyl acrylate is particularly preferred. Furthermore, from the viewpoint of suppressing changes in the resistance value of the electrode, among the low Tg alkyl acrylates, alkyl (meth)acrylates with an alkyl group having 5 or more carbon atoms (preferably 7 or more) The ratio of the content is preferably 40% by mass or more, more preferably 60% by mass or more, particularly preferably 80% by mass or more, and most preferably 100% by mass.

Furthermore, the (meth)acrylate polymer (A) includes a homopolymer having a glass transition temperature (Tg) exceeding 0° C. (hereinafter sometimes referred to as “hard monomer”). ) as a monomer unit constituting the polymer, making it easy for the obtained adhesive to have appropriate cohesion and adhesiveness. As a result, the obtained adhesive layer becomes easily durable even under durability conditions (for example, after 1000 hours of durability conditions in a humid-heat environment of 85°C 85%RH or in a high-temperature environment of 95°C). Suppress problems such as floating and peeling at the interface with the adherend.

Examples of the hard monomers include methyl acrylate (Tg 10°C), methyl methacrylate (Tg 105°C), ethyl methacrylate (Tg 65°C), n-butyl methacrylate ( Tg 20°C), isobutyl methacrylate (Tg 48°C), tertiary butyl methacrylate (Tg 107°C), n-octadecyl acrylate (Tg 30°C), methacrylic acid n-octadecyl ester (Tg 38°C), cyclohexyl acrylate (Tg 15°C), cyclohexyl methacrylate (Tg 66°C), phenoxyethyl acrylate (Tg 5°C), formazan Phenoxyethyl acrylate (Tg 54°C), Benzyl methacrylate (Tg 54°C), Isocamyl acrylate (Tg 94°C), Isocamyl methacrylate (Tg 180°C), Propylene Amadantyl acrylate (Tg 145°C), adamantyl acrylate (Tg 115°C), adamantyl methacrylate (Tg 141°C), dimethylacrylamide (Tg 89°C), Acrylic monomers such as acrylamide (Tg 165°C), vinyl acetate (Tg 32°C), and styrene (Tg 80°C) are preferable, and from the viewpoint of compatibility, acrylic monomers such as Body is better. These materials may be used alone or in combination of two or more.

In particular, from the viewpoint of imparting appropriate cohesive force and adhesiveness to the obtained adhesive and effectively suppressing problems such as floating or peeling at the interface with the adherend, the glass transition temperature of the above-mentioned hard monomer (Tg) is preferably 60°C or higher, and particularly preferably 90°C or higher. Furthermore, considering the miscibility and copolymerization with other monomers constituting the (meth)acrylate polymer (A), the glass transition temperature (Tg) of the above-mentioned hard monomers is preferably below 250°C, preferably 200°C Below is preferred, and below 150°C is particularly preferred.

Among the above-mentioned hard monomers, from the viewpoint of further exerting the performance of the hard monomer while preventing adverse effects on other characteristics such as miscibility with the silane coupling agent (B), a group selected from the group consisting of methyl methacrylate At least one selected from the group consisting of ester, isocamphoryl acrylate and acryloylmorphin. In particular, it is preferable to use methyl methacrylate alone or to use isocamphoryl acrylate and acryloylmorphin in combination.

From the viewpoint of imparting appropriate cohesive force and adhesiveness to the obtained adhesive, in the (meth)acrylate polymer (A), as a monomer constituting the polymer, the above-mentioned hard monomer contains 5 mass % or more, more preferably 10% by mass or more, and particularly preferably 15% by mass or more.

Furthermore, from the viewpoint of excellent mutual solubility between the obtained (meth)acrylate polymer (A) and the silane coupling agent (B), as monomers constituting the polymer, the above-mentioned hard monomers are It is preferably at most 50% by mass, more preferably at most 40% by mass, and particularly preferably at most 30% by mass.

The (meth)acrylate polymer (A) may contain other monomers as monomer units constituting the polymer as required. As other monomers, in order not to interfere with the action of monomers containing reactive functional groups, it is preferable not to include reactive functional groups. Examples of the above-mentioned other monomers include alkoxyalkyl (meth)acrylates such as methoxyethyl (meth)acrylate and ethoxyethyl (meth)acrylate. These materials may be used alone or in combination of two or more.

The (meth)acrylate polymer (A) is preferably a solution polymer obtained by a solution polymerization method. Because it is a solution polymer, it is easy to obtain a polymer with a high molecular weight, and can obtain excellent durability (for example, even after 1000 hours in a humid heat environment of 85°C 85%RH or in a high temperature environment of 95°C, There will be no problems such as floating or peeling on the interface with the adherend, etc.) Adhesives.

The polymerization form of the (meth)acrylate polymer (A) may be a random (random) copolymer or a block (block) copolymer.

The lower limit of the weight average molecular weight of the (meth)acrylate polymer (A) is preferably at least 200,000, particularly preferably at least 300,000, and more preferably at least 400,000. When the lower limit value of the weight-average molecular weight of the (meth)acrylate polymer (A) is as described above, the resulting adhesive becomes excellent in durability (for example, even under moist heat of 85°C 85%RH environment or in a high temperature environment of 95°C for 1000 hours, there will be no problems such as floating or peeling at the interface with the adherend). In addition, in this specification, a weight average molecular weight is the value of standard polystyrene conversion measured by the gel permeation chromatography (gel permeation chromatography, GPC) method.

Furthermore, the upper limit of the weight average molecular weight of the (meth)acrylate polymer (A) is preferably at most 1,200,000, particularly preferably at most 900,000, and more preferably at most 750,000. When the upper limit of the weight average molecular weight of the (meth)acrylate polymer (A) is as described above, the obtained adhesive can exhibit appropriate adhesiveness.

In addition, in the adhesive composition P, one type of (meth)acrylate polymer (A) may be used individually, or may be used in combination of 2 or more types.

(1-2) Silane coupling agent (B) According to the adhesive composition P of the present embodiment, by including the silane coupling agent (B) having alkoxysilyl groups at both ends, as described above, the resistance value of the electrode that the obtained adhesive is in contact with can be suppressed. Variety. Furthermore, the obtained adhesive has improved adhesion to adherends, especially glass parts, and becomes excellent in durability (for example, even in a humid heat environment of 85° C. 85% RH or at 95 After 1000 hours in a high temperature environment of ℃, there will be no problems such as floating or peeling at the interface with the adherend).

（在化學式中，R¹ 係可以具有氮原子的2價烴基。在化學式中，R² ～R⁷ 係各自獨立地為烷基。）The silane coupling agent (B) is an organosilicon compound having alkoxysilyl groups at both ends, preferably a compound represented by the following general formula (I). [chemical formula 2]

(In the chemical formula, R ¹ is a divalent hydrocarbon group that may have a nitrogen atom. In the chemical formula, R ² to R ⁷ are each independently an alkyl group.)

The number of carbon atoms in the divalent hydrocarbon group of ^R1 above is preferably 1 to 10, particularly preferably 3 to 9, and more preferably 4 to 8, in order to suppress the effect on the resistance value of metal electrodes (especially silver electrodes). From the point of view, 5~7 is the best. Furthermore, the above-mentioned hydrocarbon group is preferably a saturated hydrocarbon group, and is particularly preferably a chain-like saturated hydrocarbon group. Furthermore, the above-mentioned hydrocarbon group preferably contains an alkylene, and is particularly preferably an alkylene itself. The number of carbon atoms of the above-mentioned alkylene group is preferably 1 to 10, particularly preferably 3 to 9, and more preferably 4 to 8. From the viewpoint of the effect of suppressing the resistance value of metal electrodes (especially silver electrodes) Look, 5~7 is the best.

When the above-mentioned R ¹ has a nitrogen atom, this nitrogen atom may also exist in the side chain of the above-mentioned hydrocarbon group, but is preferably present in the main chain of the above-mentioned hydrocarbon group. When the above-mentioned R ¹ has a nitrogen atom, the number of nitrogen atoms contained in R ¹ is preferably 1-5, and particularly preferably 2-3. The above-mentioned nitrogen atom is preferably an amine group or an amide group, particularly preferably an amine group, and is more preferably present in the main chain of the above-mentioned hydrocarbon group as a secondary amine or a tertiary amine.

In the case where ^R1 above has a nitrogen atom, ^R1 preferably has a skeleton of -(CH) _m -NH-, more preferably a skeleton of -(CH) _m -NH-(CH) _n- , and The skeleton containing -(CH) _m -NH-(CH) _n -NH- is particularly preferred, and the skeleton containing -(CH) _m -NH-(CH) _n -NH-(CH)p- is more preferable . The aforementioned m, n, and p are positive integers, preferably 1-5, and particularly preferably 2-4.

The above-mentioned R ¹ preferably does not have a sulfur atom in the main chain. When the main chain has sulfur atoms, it becomes easy to dissociate from adhesives and metals (especially silver) in the durability test environment (for example, in a humid heat environment of 85°C 85%RH or in a high temperature environment of 95°C). ) or metal oxides (especially ITO) at the interface between electrodes began to generate metal sulfides. Therefore, there may be a fear of hindering the aforementioned effect of suppressing changes in resistance value.

The number of carbon atoms of the above-mentioned alkyl groups of R ² to R ⁷ is preferably 1-6, particularly preferably 1-4, more preferably 1-2, and most preferably 1. All of the above-mentioned R ² to R ⁷ are preferably the same alkyl group, and most preferably all are methyl groups.

The lower limit of the content of the silane coupling agent (B) in the adhesive composition P is preferably at least 0.01 parts by mass, preferably 0.1 parts by mass, relative to 100 parts by mass of the (meth)acrylate polymer (A). The above is preferable, especially preferably at least 0.16 parts by mass, and more preferably at least 0.22 parts by mass. Furthermore, the upper limit of the content is preferably 1.5 parts by mass or less, particularly preferably 1 part by mass or less, and more preferably 0.6 parts by mass or less. When the content of the silane coupling agent (B) is within the above range, the effect of the silane coupling agent (B) can be effectively exerted, the change in the resistance value of the electrode can be more effectively suppressed, and the heat-and-moisture whitening resistance and durability can be improved. become more excellent.

(1-3) Crosslinking agent (C) The adhesive composition P preferably includes a crosslinking agent (C). The adhesive composition P includes a cross-linking agent (C), so that the (meth)acrylate polymer (A) is cross-linked to form a three-dimensional network structure, and the cohesion of the obtained adhesive can be improved, and the durability.

As the crosslinking agent (C), any one can react with the reactive functional group of the (meth)acrylate polymer (A), for example, isocyanate crosslinking agents, epoxy-based Crosslinking agent, amine crosslinking agent, melamine crosslinking agent, aziridine crosslinking agent, hydrazine crosslinking agent, aldehyde crosslinking agent, oxazoline crosslinking agent, metal alkoxide crosslinking agent agent, metal chelating crosslinking agent, metal salt crosslinking agent, ammonium salt crosslinking agent, etc. In the case where the (meth)acrylate polymer (A) includes a hydroxyl group-containing monomer as a monomer unit constituting the polymer, it is preferable to use an isocyanate crosslinking agent having excellent reactivity with hydroxyl groups. In addition, as the crosslinking agent (C), one type may be used alone, or two or more types may be used in combination.

The isocyanate-based crosslinking agent includes at least polyisocyanate (polyisocyanate) compounds. Examples of the polyisocyanate compound include aromatic polyisocyanates such as toluene diisocyanate, diphenylmethane diisocyanate, and xylylene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, and isophorone diisocyanate. Isocyanate (isophorone diisocyanate), alicyclic polyisocyanate such as hydrogenated diphenylmethane diisocyanate, etc., as well as the above-mentioned biuret, isocyanurate (isocyanurate) and ethylene glycol, propylene glycol, new Adducts of reactants such as pentylene glycol, trimethylolpropane, castor oil, etc., reacted with low-molecular active hydrogen-containing compounds, etc. Among them, trimethylolpropane-modified aromatic polyisocyanate is preferable from the viewpoint of reactivity with hydroxyl groups, and trimethylolpropane-modified toluene diisocyanate is particularly preferable.

The lower limit of the content of the crosslinking agent (C) in the adhesive composition P is preferably at least 0.001 parts by mass, preferably 0.01 parts by mass, relative to 100 parts by mass of the (meth)acrylate polymer (A). Above is especially preferable, and 0.1 mass part or more is more preferable. Furthermore, the upper limit of the content is preferably at most 10 parts by mass, particularly preferably at most 5 parts by mass, and more preferably at most 1 part by mass. When the content of the crosslinking agent (C) is within the above-mentioned range, the obtained adhesive has appropriate cohesive force, and an adhesive having excellent durability can be obtained. Furthermore, from the viewpoint of more effectively suppressing changes in the resistance value of the electrode, the upper limit of the content of the crosslinking agent (C) is preferably 0.5 parts by mass or less.

(1-4) Active energy ray-curing component (D) When the adhesive obtained from the adhesive composition P according to this embodiment is an active energy ray-curable adhesive, the adhesive composition P preferably includes an active energy ray-curable component (D). When the adhesive composition P contains the active energy ray-curable component (D), the adhesive obtained by crosslinking (thermally crosslinking) the adhesive composition P becomes an active energy ray-curable adhesive. It is presumed that in this active energy ray-curable adhesive, the active energy ray-curable components (D) are mutually polymerized by hardening by irradiating the adherend with active energy rays after the adherend is attached, and the polymerized active energy The radiation curable component (D) is intertwined with the crosslinked structure (three-dimensional network structure) of the (meth)acrylate polymer (A). Adhesives with such an advanced structure exhibit high cohesive force, high coating film strength, and thus become more excellent in durability.

The active energy ray-curing component (D) is not particularly limited as long as it can be cured by irradiation of active energy rays and can obtain the above-mentioned effects, and may be any of monomers, oligomers, or polymers, or may be is a mixture of the above. Among them, polyfunctional acrylate-based monomers capable of obtaining a more excellent durable adhesive are preferable.

Examples of polyfunctional acrylate monomers include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, (Meth)acrylate, Polyethylene Glycol Di(meth)acrylate, Neopentyl Glycol Adipate Di(meth)acrylate, Hydroxypivalate Neopentyl Glycol Di(meth)acrylate, Dicyclopentane di(meth)acrylate, caprolactone-modified dicyclopentene di(meth)acrylate, ethylene oxide-modified di(meth)acrylate, di(acryloxy ethyl) isocyanurate, allylated cyclohexyl di(meth)acrylate, ethoxylated bisphenol A diacrylate, 9,9-bis[4-(2-acryloxy Difunctional type of ethoxy)phenyl]fluorene, etc.; trimethylolpropane tri(meth)acrylate, dipenteoerythritol tri(meth)acrylate, propionic acid modified dipentapentyl tetra Alcohol tri(meth)acrylate, neopentylitol tri(meth)acrylate, propylene oxide modified trimethylolpropane tri(meth)acrylate, ginseng(acryloxyethyl)iso Trifunctional type of cyanurate, ε-caprolactone-modified ginseng-(2-(meth)acryloxyethyl)isocyanurate, etc.; diglyceryl tetra(meth)acrylate 4-functional group type such as , neopentylthritol tetra(meth)acrylate, etc.; 5-functional group type such as propionic acid-modified diperythritol penta(meth)acrylate; diperythritol hexa( Hexafunctional type such as meth)acrylate, caprolactone-modified diperythritol hexa(meth)acrylate, etc. Among them, from the viewpoint of imparting appropriate cohesive force and adhesiveness to the obtained adhesive and effectively suppressing problems such as floating or peeling at the interface with the adherend, bis(acryloxyethyl) ) isocyanurate, ginseng (acryloxyethyl) isocyanurate, ε-caprolactone modified ginseng (2-(meth)acryloxyethyl) isocyanurate Polyfunctional acrylate monomers containing an isocyanurate structure in the molecule are preferred, and polyfunctional acrylate monomers with more than three functional groups and an isocyanurate structure in the molecule are more preferred. Best, and ε-caprolactone-modified ginseng (2-(meth)acryloxyethyl) isocyanurate is particularly preferred. The above materials may be used alone or in combination of two or more. In addition, the molecular weight of the polyfunctional acrylate monomer is preferably less than 1,000 from the viewpoint of compatibility with the (meth)acrylate copolymer (A).

As the active energy ray curable component (D), an active energy ray curable acrylate oligomer can also be used. Examples of such acrylate oligomers include polyester acrylates, epoxy acrylates, urethane acrylates, polyether acrylates, polybutadiene acrylates, silicon Oxyalkylene acrylates, etc.

The weight average molecular weight of the above-mentioned acrylate oligomer is preferably 50,000 or less, particularly preferably 1,000-50,000, and more preferably 3,000-40,000. These acrylate oligomers may be used alone or in combination of two or more.

In addition, an adduct acrylate polymer (adduct acrylate polymer) in which a group having a (meth)acryloyl group is introduced into a side chain can also be used as the active energy ray curable component (D). This adduct acrylate polymer can be made by using a copolymer of (meth)acrylate and a monomer having a crosslinkable functional group in the molecule, and a part of the crosslinkable functional group of the copolymer can be combined with It is obtained by reacting a compound having a group that reacts with a (meth)acryl group and a crosslinkable functional group.

The weight average molecular weight of the above-mentioned adduct acrylate polymer is preferably about 50,000 to 900,000, and particularly preferably about 100,000 to 500,000.

The active energy ray-curing component (D) can be used by selecting one of the above-mentioned polyfunctional acrylate monomers, acrylate oligomers, and adduct acrylate polymers, or by combining two of them. The above-mentioned use may be used in combination with active energy ray-curable components other than the above.

When the adhesive composition P includes the active energy ray-curable component (D), the content of the active-energy ray-curable component (D) is It is preferably at least 2 parts by mass, more preferably at least 3 parts by mass, and particularly preferably at least 4 parts by mass. Furthermore, the above content is preferably not more than 20 parts by mass, more preferably not more than 10 parts by mass, particularly preferably not more than 8 parts by mass, and more preferably not more than 6 parts by mass. When the content of the active energy ray-curable component (D) is within the above range, the adhesive cured by active energy ray can have more excellent durability.

(1-5) Photopolymerization initiator (E) In the case where the adhesive obtained from the adhesive composition P according to the present embodiment is an active energy ray-curable adhesive, when ultraviolet rays are used as the active energy ray, the adhesive composition P further includes a photopolymerization initiator Agent (E) is preferred. By including the photopolymerization initiator (E) as described above, the active energy ray-curable component (D) can be efficiently polymerized, and the polymerization hardening time and the irradiation amount of the active energy ray can be reduced.

Examples of such photopolymerization initiators (E) include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylamino Acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-benzene Propan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morphine propane, 4-(2-hydroxyethyl oxy)phenyl-2-(hydroxy-2-propyl)ketone, benzophenone, p-phenylbenzophenone, 4,4'-diethylaminobenzophenone, dichlorodi Benzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tertiary butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone (2-methylthioxanthone), 2-ethylanthraquinone Benzyl thioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal , p-dimethylaminobenzoate, oligo[2-hydroxy-2-methyl-1[4-(1-methylvinyl)phenyl]acetone], 2,4,6-trimethyl Benzoyl-diphenyl-phosphine oxide, etc. These materials may be used alone or in combination of two or more.

When the adhesive composition P includes an active energy ray-curable component (D) and a photopolymerization initiator (E), the photopolymerization initiator (E) is The lower limit of the content of (E) is preferably at least 0.1 parts by mass, particularly preferably at least 1 part by mass, and more preferably at least 5 parts by mass. Furthermore, the upper limit is preferably at most 30 parts by mass, particularly preferably at most 20 parts by mass, and more preferably at most 15 parts by mass.

(1-6) Various additives Various additives commonly used in acrylic adhesives, such as antirust agents, antistatic agents, tackifiers, antioxidants, light stabilizers, softeners, fillers, and refractive index modifiers, can be added to the adhesive composition P according to requirements wait.

In addition, the adhesive composition P represents a mixture of various components remaining in the adhesive layer in the original state or in a reacted state, and the adhesive composition P does not include components removed in the drying step, etc., For example, a polymerization solvent and a dilution solvent described later.

In the adhesive composition P according to the present embodiment, by including the silane coupling agent (B) having alkoxysilyl groups at both ends, the obtained adhesive can exhibit an excellent effect of suppressing changes in resistance value, Furthermore, by further including a rust inhibitor, the effect of suppressing the change in resistance value (especially the effect of suppressing the change in resistance value in a humid heat environment of 85° C. 85% RH) can be made more excellent.

Examples of rust inhibitors include azole compounds having a hydroxyl group, triazole compounds, benzotriazole compounds, thiazole compounds, benzothiazole compounds, imidazole compounds, benzimidazole compounds, phosphorus Compounds, amine compounds, nitrite compounds, surfactants, etc. Among them, benzotriazole-based rust inhibitors are preferable from the viewpoint of anti-corrosion performance. Moreover, a rust preventive agent may be used individually by 1 type, and may use it in combination of 2 or more types.

Examples of benzotriazole-based rust inhibitors include 1H benzotriazole, tolylbenzotriazole, 1-[N,N-bis(2-ethylhexyl)aminomethyl]benzo Triazole, 1-[N,N-bis(2-ethylhexyl)aminomethyl]methylbenzotriazole, etc.

The content of the antirust agent in the adhesive composition P is preferably at least 0.001 parts by mass, more preferably at least 0.005 parts by mass, and preferably at least 0.01 parts by mass relative to 100 parts by mass of the (meth)acrylate polymer (A). Parts by mass or more are particularly preferred, and parts by mass or more are more preferably 0.1 parts by mass or more. Furthermore, the above-mentioned content is preferably not more than 1.0 parts by mass, particularly preferably not more than 0.7 parts by mass, and more preferably not more than 0.5 parts by mass. With the content of the antirust agent within the above range, the effect of promoting the effect of suppressing the change of the resistance value (especially the effect of suppressing the change of the resistance value in a humid heat environment of 85° C. 85% RH) can be exerted well, and the effect is not will hinder adhesion.

(2) Preparation of adhesive composition By preparing the (meth)acrylate polymer (A), and mixing the obtained (meth)acrylate polymer (A) with the silane coupling agent (B), at the same time adding a crosslinking agent (C ), an active energy ray hardening component (D), a photopolymerization initiator (E), additives, etc., and then an adhesive composition P is prepared.

The (meth)acrylate polymer (A) can be produced by polymerizing a mixture of monomer units constituting the polymer by a general radical polymerization method. The (meth)acrylate polymer (A) can be polymerized by a solution polymerization method or the like using a polymerization initiator as needed. Examples of the polymerization solvent include ethyl acetate, n-butyl acetate, isobutyl acetate, toluene, acetone, hexane, methyl ethyl ketone, and the like, and two or more of them may be used in combination.

As a polymerization initiator, an azo compound, an organic peroxide, etc. are mentioned, and 2 or more types may be used in combination. Examples of azo compounds include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane Alkane 1-carbonitrile) (1,1'-azobis(cyclohexane-1-carbonitrile)), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-Dimethyl-4-methoxyvaleronitrile), 2,2'-Azobismethyl (2-methylpropionate), 4,4'-Azobis(4-cyano valeric acid), 2,2'-azobis(2-hydroxymethylpropionitrile), 2,2'-azobis[2-(2-imidazolin-2-yl)propane], etc.

Examples of organic peroxides include benzoyl peroxide, tertiary butyl perbenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, peroxydicarbonate, and peroxydicarbonate. Bis(2-ethoxyethyl)oxydicarbonate, tertiary butyl peroxyneodecanoate, tertiary butyl peroxypivalate, (3,5,5-trimethylhexyl)peroxy oxides, diacryl peroxide, diacetyl peroxide, etc.

In addition, in the above-mentioned polymerization step, the weight average molecular weight of the obtained polymer can be adjusted by preparing a chain transfer agent such as 2-mercaptoethanol.

After obtaining (meth)acrylate polymer (A), add silane coupling agent (B) to the solution of (meth)acrylate polymer (A), and add crosslinking agent (C), active energy The radiation-curable component (D), photopolymerization initiator (E), additives, diluting solvent, etc. are mixed well to obtain an adhesive composition P (coating solution) diluted with a solvent.

As the diluting solvent, for example, aliphatic hydrocarbons such as hexane, heptane, and cyclohexane, aromatic hydrocarbons such as toluene and xylene, halogenated hydrocarbons such as methane chloride and vinyl chloride, methanol, ethanol, propanol, butane, etc. Alcohols, alcohols such as 1-methoxy-2-propanol, ketones such as acetone, methyl ethyl ketone, 2-pentanone, isophorone, cyclohexanone, etc., ethyl acetate, butyl acetate, etc. Cellosolve solvents such as ester and ethyl cellosolve, etc.

The concentration and viscosity of the coating solution prepared in the above manner are not particularly limited as long as they are within the range where coating is possible, and can be appropriately selected depending on the situation. For example, it is diluted so that the concentration of the adhesive composition P may be 10 to 40% by mass. In addition, when obtaining a coating solution, addition of a diluent solvent etc. is not essential, and the diluent solvent does not need to be added as long as the adhesive composition P has the viscosity etc. which can be applied. In this case, the adhesive composition P is a coating solution in which the polymerization solvent of the (meth)acrylate polymer (A) is directly used as a dilution solvent.

〔adhesive〕 The adhesive according to this embodiment is obtained by crosslinking the aforementioned adhesive composition P. Crosslinking of the adhesive composition P can be performed by heat treatment. In addition, this heat treatment can also be used as a drying treatment at the time of volatilizing the diluent solvent and the like of the applied adhesive composition P.

In the case of heat treatment, the heating temperature is preferably 50 to 150°C, and particularly preferably 70 to 120°C. Furthermore, the heating time is preferably 30 seconds to 10 minutes, and particularly preferably 50 seconds to 2 minutes. After the heat treatment, an aging period of about 1 to 2 weeks at normal temperature (for example, 23° C., 50% RH) may also be provided as needed. When this aging period is required, the adhesive layer is formed after the aging period has elapsed, and when the aging period is not required, the adhesive layer is formed after the heat treatment is completed.

The lower limit of the gel fraction of the adhesive of this embodiment is preferably at least 30%, particularly preferably at least 40%, and more preferably at least 45%. When the lower limit of the gel fraction of the adhesive agent is as described above, the cohesive force can be improved and the durability will become higher. Furthermore, the upper limit of the above-mentioned gel fraction is preferably 85% or less, more preferably 80% or less, particularly preferably 75% or less, and more preferably 73% or less. When the upper limit of the gel fraction of the adhesive is as described above, the adhesive does not become too hard, and the adhesive force becomes higher. The measurement method of the gel fraction of this adhesive is shown in the test example described later.

〔adhesive sheet〕 As shown in FIG. 1, according to the adhesive sheet 1 of the present embodiment, two release sheets 12a and 12b and an adhesive sandwiched between the two release sheets 12a and 12b are in contact with the release surfaces of the two release sheets 12a and 12b. layer 11. However, the release sheets 12a and 12b in the adhesive sheet 1 are not essential structural elements, and are peeled off and removed when the adhesive sheet 1 is used. In addition, the release surface of the release sheet in this specification refers to the surface having releasability in the release sheet, and also includes the surface after the release treatment and the surface that exhibits the releasability even without the release treatment.

(1) Adhesive layer The adhesive layer 11 is composed of the aforementioned adhesive. The lower limit of the thickness of the adhesive layer 11 (value measured according to JIS K7130) is preferably at least 10 μm, particularly preferably at least 25 μm, and more preferably at least 45 μm. When the lower limit of the thickness of the adhesive layer 11 is as described above, the excellent adhesive force can fully be exhibited. Furthermore, the upper limit of the thickness of the adhesive layer 11 is preferably 300 μm or less, more preferably 250 μm or less, particularly preferably 100 μm or less, and more preferably 70 μm or less. When the upper limit value of the thickness of the adhesive layer 11 is as mentioned above, workability becomes favorable. In addition, the adhesive layer 11 may be formed as a single layer, or may be laminated and formed as a plurality of layers.

(2) Peeling sheet The release sheets 12a and 12b are not particularly limited, and known plastic films can be used. For example, 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 film, polyurethane film, ethylene vinyl acetate film, ionomer resin film, ethylene-(meth)acrylic acid copolymer film, ethylene- (Meth)acrylate copolymer film, polystyrene film, polycarbonate film, polyimide film, fluororesin film, etc. Furthermore, crosslinked films of the above materials may also be used. Furthermore, laminated films of the above materials can also be used.

The release surfaces of the release sheets 12a and 12b (particularly, the surfaces in contact with the adhesive layer 11) are preferably subjected to release treatment. Examples of the release agent used in the release treatment include alkyd-based, silicone-based, fluorine-based, unsaturated polyester-based, polyolefin-based, and wax-based release agents. In addition, among the release sheets 12a and 12b, it is preferable that one of the release sheets is a heavy-release type release sheet with a large release force and the other is a light-release type release sheet with a small release force.

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

(3) Manufacture of adhesive sheets As one of the production examples of the adhesive sheet 1, the above-mentioned coating solution of the adhesive composition P is coated on the peeling surface of a peeling sheet 12a (or 12b), and heat treatment is performed so that the adhesive composition P is exchanged. Link, and after the coating layer is formed, the release surface of another release sheet 12b (or 12a) is superimposed on this coating layer. If a curing period is required, the adhesive layer 11 is formed by placing the above-mentioned coating layer for a period of curing time, and if the curing period is not required, the above-mentioned coating layer is directly used as the adhesive layer 11 . In this way, the above-mentioned adhesive sheet 1 can be obtained. The conditions for heat treatment and aging are as described above.

As another production example of the adhesive sheet 1, the above-mentioned coating solution of the adhesive composition P is coated on the peeling surface of one peeling sheet 12a, and heat treatment is performed so that the adhesive composition P is cross-linked and the coating is formed. Cloth layer, and then obtain the release sheet 12a with coating layer. Furthermore, on the peeling surface of the other peeling sheet 12b, the coating solution of the above-mentioned adhesive composition P is coated, and heat treatment is carried out so that the adhesive composition P is cross-linked, and a coating layer is formed, and the adhesive composition P is further obtained. Release sheet 12b with coating layer. Next, the peeling sheet 12a with a coating layer and the peeling sheet 12b with a coating layer are bonded together so that both coating layers may contact each other. In the case where a curing period is required, the adhesive layer 11 is formed by placing the above-mentioned laminated coating layer for a period of curing period, and when the curing period is not required, the above-mentioned laminated coating layer is directly used as the adhesive layer 11 . In this way, the above-mentioned adhesive sheet 1 can be obtained. According to this manufacturing example, even if the adhesive layer 11 is relatively thick, it is possible to stably manufacture the adhesive layer 11 .

As a coating method of the above-mentioned coating solution of the adhesive composition P, for example, a bar coating method, a knife coating method, a roll coating method, or a blade coating method can be used. Coating method, die coating method, gravure coating method, etc.

(4) Physical properties of the adhesive sheet (adhesive force) The lower limit of the adhesive force of the adhesive sheet 1 according to the present embodiment to soda-lime glass is preferably 10 N/25 mm or more, particularly preferably 13 N/25 mm or more, and more preferably 15 N/25 mm or more. When the lower limit of the adhesive force is as described above, the durability of the adhesive layer 11 becomes more excellent. Furthermore, the upper limit of the adhesive force is preferably 45 N/25 mm or less, more preferably 40 N/25 mm or less, particularly preferably 30 N/25 mm or less, and more preferably 24 N/25 mm or less. When the upper limit of the above-mentioned adhesive force is as described above, good reworkability can be obtained, and re-pasting can be achieved even if an adhesion error occurs.

The above-mentioned adhesive force is basically the adhesive force measured according to the 180-degree peeling method of JIS Z0237:2009. The width of the measurement sample is set to 25mm and the length is set to 100mm. After pressurizing at 50° C. for 20 minutes, it was left to stand at normal pressure, 23° C., and 50% RH for 24 hours, and then measured at a peeling speed of 300 mm/min.

〔display body〕 The display body according to this embodiment includes a first display body structural member, a second display body structural member, and an adhesive layer for bonding the first display body structural member and the second display body structural member to each other. The above-mentioned adhesive layer is composed of the above-mentioned adhesive of the present embodiment. Here, the first display component and/or the second display component has an electrode made of metal or metal oxide at least on the surface of the bonded side (adhesive layer side). It is preferable that the second display structure member has the above-mentioned electrodes on at least the surface of the bonding side.

Examples of the display body include liquid crystal (LCD) displays, light emitting diode (LED) displays, organic electroluminescence (organic EL) displays, electronic paper, and the like, and may be touch panels. In addition, as a display body, the member which comprises a part of the example mentioned above may be sufficient.

Preferably, the first display structural member is a protective panel composed of a laminate including glass plates, plastic plates, and the like in addition to glass plates, plastic plates, and the like. The first display constituent member may have a step on the surface on the side of the adhesive layer. In this case, specifically, it is preferable to have a level difference due to the printed layer. This printed layer is usually formed in a frame shape.

The above-mentioned glass plate is not particularly limited, and examples thereof include chemically strengthened glass, alkali-free glass, quartz glass, soda-lime glass, glass containing barium and strontium, aluminosilicate glass, lead glass, and borosilicate glass. , barium borosilicate glass, etc. The thickness of the glass plate is not particularly limited, usually 0.1 to 5 mm, preferably 0.2 to 2 mm.

It does not specifically limit as said plastic board, For example, an acrylic board, a polycarbonate board, etc. are mentioned. The thickness of the plastic plate is not particularly limited, usually 0.2-5mm, preferably 0.4-3mm.

In addition, various functional layers (electrode layer, silicon dioxide layer, hard coat layer, anti-glare layer, etc.) .

The material constituting the printing layer is not particularly limited, and known printing materials can be used. The lower limit of the thickness of the printing layer (that is, the height of the step) is preferably 3 μm or more, more preferably 5 μm or more, particularly preferably 7 μm or more, and most preferably 10 μm or more. When the lower limit is equal to or greater than the above-mentioned numerical value, it is possible to sufficiently ensure concealment of the electrical wiring such as being invisible from the side of a viewer. Furthermore, the upper limit is preferably not more than 50 μm, more preferably not more than 35 μm, particularly preferably not more than 25 μm, and more preferably not more than 20 μm. When the upper limit value is below the above-mentioned numerical value, deterioration of the step compliance of the adhesive layer with respect to the said printing layer can be prevented.

The second display structure components include optical components that should be attached to the first display structure components, display modules (such as liquid crystal (LCD) modules, light emitting diode (LED) modules, organic electroluminescent ( organic EL) module, etc.), an optical component that is a part of a display module, or a laminate including a display module, and has electrodes made of metal or metal oxide on at least the surface on the side of the adhesive layer better.

As said optical member, a film sensor, an electrode film, a metal nanowire film, a wire grid polarizing film, etc. are mentioned, for example.

Examples of electrodes made of metal include metal wirings (including mesh-like, grid-like, and nanowire-like) made of silver, silver alloys, copper, copper alloys, and the like. In particular, an electrode constituting a touch panel is a preferable example, and specifically, a metal wiring included in a film sensor is a preferable example. Among the above-mentioned metal wirings, metal wirings made of silver or silver alloy nanoparticles are preferable, and the excellent effect of suppressing changes in resistance value by the adhesive layer 11 can be easily exhibited for this metal wiring. .

Examples of electrodes made of the metal oxides include electrodes obtained by patterning a transparent conductive film made of metal oxides such as indium tin oxide (ITO) and zinc oxide. Among the above, an electrode obtained by patterning a transparent conductive film made of ITO is particularly preferable. With this ITO transparent conductive film, it is easy to exhibit the suppression of resistance change by the adhesive layer 11 excellent effect.

As an example of the display body according to this embodiment, FIG. 2 shows a capacitive touch panel 2 . The touch panel 2 includes a display module 3, a first film sensor 5a laminated on the display module 3 via an adhesive layer 4, and a first film sensor 5a laminated on the first film sensor via a first adhesive layer 11. The second film sensor 5b on the device 5a, and the cover material 6 laminated on the second film sensor 5b via the second adhesive layer 11. Since the printed layer 7 is formed on the surface of the cover material 6 on the side of the second adhesive layer 11 , there are steps depending on whether the printed layer 7 is formed or not. In this embodiment, the cover material 6 corresponds to the above-mentioned first display component, and the second film sensor 5b corresponds to the above-mentioned second display component, or the second film sensor 5b corresponds to the above-mentioned second display component. 1. The structural member of the display body and the first film sensor 5a correspond to the above-mentioned second structural member of the display body.

Considering the effect of suppressing the change of the resistance value, both the first adhesive layer 11 and the second adhesive layer 11 in the touch panel 2 are preferably the adhesive layer 11 of the adhesive sheet 1 . In addition, when the first adhesive layer 11 or the second adhesive layer 11 is not the adhesive layer 11 of the above-mentioned adhesive sheet 1, examples of the adhesive constituting the above-mentioned adhesive layer include acrylic adhesives, rubber-based adhesives, etc. Adhesives, silicone adhesives, urethane adhesives, polyester adhesives, polyvinyl ether adhesives, etc., among which acrylic adhesives are preferred.

The adhesive layer 4 may be formed by the adhesive layer 11 of the above-mentioned adhesive sheet 1, or may be formed by other kinds of adhesive or adhesive sheet. In the latter case, examples of the adhesive constituting the adhesive layer 4 include acrylic adhesives, rubber adhesives, silicone adhesives, urethane adhesives, polyester adhesives, Polyvinyl ether adhesives, etc., among which acrylic adhesives are preferred.

The first film sensor 5 a and the second film sensor 5 b in this embodiment include a base film 51 and electrodes 52 formed on the base film 51 , respectively. It does not specifically limit as the base film 51, For example, a polyethylene terephthalate film, an acrylic film, a polycarbonate film etc. can be used.

The electrodes 52 are exemplified by the aforementioned electrodes. Usually, one of the electrodes 52 of the first film sensor 5a and the electrode 52 of the second film sensor 5b forms a circuit pattern in the X-axis direction, and the other forms a circuit pattern in the Y-axis direction.

The electrode 52 of the 2nd film sensor 5b in this embodiment is located in the upper side of the 2nd film sensor 5b in FIG. On the other hand, the electrodes 52 of the first film sensor 5a are located above the first film sensor 5a in FIG. 2 , but are not limited thereto, and may be located below the first film sensor 5a.

An example of the manufacturing method of the touch panel 2 is described below. As the adhesive sheet 1, the first adhesive sheet 1 and the second adhesive sheet 1 were prepared. One of the peeling sheets 12a is peeled off from the first adhesive sheet 1, and the exposed adhesive layer 11 (first adhesive layer) is bonded to the above-mentioned first film sensor 5a so as to be in contact with the electrode 52 of the first film sensor 5a. 1 film sensor 5a. Furthermore, one of the release sheets 12a is peeled off from the second adhesive sheet 1, and the exposed adhesive layer 11 (second adhesive layer) is bonded so as to be in contact with the electrode 52 of the second film sensor 5b. to the aforementioned second film sensor 5b.

After that, the other release sheet 12b in the first adhesive sheet 1 is peeled off, and the exposed first adhesive layer 11 is brought into contact with the laminated layer of the second adhesive layer 11 in the second film sensor 5b. The side is the opposite surface (the exposed surface of the base film 51 of the second film sensor 5b), so that both are bonded to each other. In this way, a laminate formed by sequentially laminating the release sheet 12b, the second adhesive layer 11, the second film sensor 5b, the first adhesive layer 11, and the first film sensor 5a can be obtained.

Next, the adhesive layer 4 provided on the release sheet was bonded to the surface of the laminate on the first film sensor 5 a side (exposed surface of the base film 51 of the first film sensor 5 a ). After that, the peeling sheet 12b is peeled off from the above-mentioned laminate, and the above-mentioned covering material 6 is bonded on the exposed second adhesive layer 11 so that the side of the printed layer 7 of the covering material 6 is in contact with the second adhesive layer 11. . Through the above bonding, the covering material 6, the second adhesive layer 11, the second film sensor 5b, the first adhesive layer 11, the first film sensor 5a, the adhesive layer 4 and the release sheet can be obtained. A structure formed by stacking layers sequentially.

After that, the peeling sheet is peeled off from the above structure, and the exposed adhesive layer 4 is bonded to the display module 3 so that the above structure is in contact with the display module 3 . In this way, the touch panel 2 shown in FIG. 2 can be manufactured.

Here, when the first adhesive layer 11 and/or the second adhesive layer 11 are composed of an active energy ray-curable adhesive, the above-mentioned structure or the adhesive layer 11 in the touch panel 2 is irradiated with active energy. energy ray. In this way, the active energy ray-curable component (D) in the adhesive layer 11 is polymerized, and the adhesive layer 11 is cured to become a cured adhesive layer. Usually, the energy ray is irradiated to the adhesive layer 11 from the surface of one side of the structure or the touch panel 2 , preferably from the side of the surface of the cover material 6 .

In addition, the term "active energy ray" refers to those having energy quanta in electromagnetic waves or charged particle beams, and specific examples thereof include ultraviolet rays, electron beams, and the like. Among active energy rays, ultraviolet rays, which are easily obtained, are particularly preferable.

Ultraviolet radiation can be irradiated by high-pressure mercury lamps, fusion-H lamps, xenon lamps, etc., and the irradiation amount of ultraviolet rays is preferably 50~1000mW/cm ² , preferably 100~600mW/cm ² . Furthermore, the amount of light is preferably 50 to 10000 mJ/cm ² or less, more preferably 80 to 5000 mJ/cm ² or less, and particularly preferably 200 to 2000 mJ/cm ² or less. On the other hand, electron beam irradiation can be performed using an electron beam accelerator or the like, and the irradiation dose of electron beam is preferably about 10 to 1000 krad.

The lower limit of the gel fraction of the adhesive (adhesive after active energy ray irradiation) constituting the hardened adhesive layer is preferably 35% or more, particularly preferably 50% or more, and 65% or more. better. When the lower limit of the gel fraction of the adhesive after active energy ray irradiation is as described above, durability becomes higher. Furthermore, the upper limit of the gel fraction is preferably at most 85%, particularly preferably at most 80%, and more preferably at most 75%. When the upper limit of the gel fraction of the adhesive after active energy ray irradiation is as described above, it is possible to prevent a reduction in adhesive force and deterioration in durability of the adhesive layer after hardening. The measurement method of the gel fraction of the adhesive after this active energy ray irradiation is as shown in the test example described later.

The lower limit of the adhesive force of the adhesive sheet having the hardened adhesive layer to soda lime glass is preferably 10N/25mm or more, particularly preferably 20N/25mm or more, and more preferably 30N/25mm or more. When the lower limit of the adhesive force is as described above, the resulting product (touch panel 2 ) has high durability. Furthermore, the upper limit of the above-mentioned adhesive force is not particularly limited, but it is usually preferably below 60N/25mm, particularly preferably below 50N/25mm, and more preferably below 45N/25mm.

The above-mentioned adhesive force is basically the adhesive force measured according to the 180-degree peeling method of JIS Z0237:2009. The width of the measurement sample is set to 25mm and the length is set to 100mm. , pressurized at 50°C for 20 minutes, irradiated with active energy rays (ultraviolet rays) under the conditions shown in the test examples described later, and left to stand at normal pressure, 23°C, 50%RH for 24 hours, and then The measurement was performed at a peel speed of 300 mm/min.

The above-mentioned touch panel 2, even under durability conditions (for example, under the conditions of durability of 1000 hours after being placed in a humid heat environment of 85° C. 85% RH or in a high temperature environment of 95° C.), by combining The adhesive layer 11 in contact with the electrode 52 includes a silane coupling agent (B) having alkoxysilyl groups at both ends, which can also effectively suppress the change of the resistance value of the electrode 52 .

Here, the change in the resistance value of the electrode 52 will be specifically described. Using the adhesive layer 11 of the adhesive sheet 1 according to this embodiment, the soda-lime glass and the ITO vapor-deposited film were bonded together, and the durability test (under a humid heat environment of 85° C. 85% RH or After 1000 hours in a high temperature environment of 95°C), the resistance value change rate of the ITO vapor-deposited film calculated by the following formula is preferably less than 400%, particularly preferably less than 350%, and less than 350%. 300% is better. In addition, the lower limit is not particularly limited, but is particularly preferably 0% or more. Similarly, the soda lime glass was bonded to the silver wiring electrode plate through the adhesive layer 11 of the adhesive sheet 1 according to the present embodiment, and the durability test (damp heat at 85°C and 85%RH) was performed on the obtained laminate. After 1000 hours in a high-temperature environment or a high-temperature environment of 95°C), the resistance value change rate of the silver wiring electrode plate calculated by the following formula is preferably less than 50%, and more preferably less than 30%. And it is better to be less than 10%. In addition, the lower limit is not particularly limited, but is particularly preferably 0% or more. Resistance value change rate (%)={(RR ⁰ )/R ⁰ }×100 (where R ⁰ is the initial resistance value (Ω) before the durability test, and R is the resistance value after the durability test (Ω ).) The details of the method for measuring the rate of change of the above-mentioned resistance value are shown in Test Examples described later.

Moreover, since the above-mentioned adhesive layer 11 has excellent resistance to wet heat and whitening, after the touch panel 2 is placed under high-temperature and high-humidity conditions (for example, 85° C., 85% RH), even after returning to normal temperature and Even in the case of normal humidity, whitening of the adhesive layer 11 can be suppressed.

The heat-and-moisture whitening resistance of the adhesive layer 11 in this embodiment can be quantitatively evaluated by the haze value. Specifically, through the adhesive layer 11 of the adhesive sheet 1 according to the present embodiment, the alkali-free glass with a thickness of 1.1 mm is bonded to an acrylic resin plate made of polymethyl methacrylate with a thickness of 1 mm, to obtain laminates. The above-mentioned laminate was stored under humid heat conditions of 85°C and 85%RH for 120 hours, and then the haze value (%) after being stored for 24 hours at room temperature and normal humidity conditions of 23°C and 50%RH (according to From the value measured in JIS K7136:2000, the same applies hereinafter) to calculate the increase in haze value (point) by subtracting the haze value (%) before the hot and humid condition. The increase in the haze value is preferably less than 5 points, particularly preferably less than 3 points, and more preferably less than 1 point. When the increase in the haze value is as described above, even after being left under hot and humid conditions, the degree of increase in the haze value is small, and whitening of the adhesive layer can be suppressed.

Furthermore, since the above-mentioned adhesive layer 11 has excellent durability, even if the touch panel 2 is placed in a humid heat environment of 85° C. 85% RH or in a high temperature environment of 95° C. for 1000 hours, adhesion can be suppressed. Problems such as floating and peeling occur at the interface between the agent layer 11 and the adherend.

The embodiments described above are described for easy understanding of the present invention, and are not described for limiting the present invention. Therefore, each element disclosed in the above-mentioned embodiments also covers all design changes and equivalents belonging to 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. In addition, in the touch panel 2 , the printed layer 7 may not be formed on the cover material 6 .

[Example] Hereinafter, the present invention will be described more specifically through 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)acrylate polymer (A) By solution polymerization, 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 (meth)acrylic acid Ester polymer (A). The molecular weight of this (meth)acrylate polymer (A) was measured by the method described later, and it was found that the weight average molecular weight (Mw) was 700,000.

2. Preparation of adhesive composition 100 parts by mass (calculated by solid content, the same below) of (meth)acrylate polymer (A) obtained in the above step 1, 0.25 parts by mass as silane mixture (B) and an organosilicon compound represented by the following structural formula (II), and 0.23 parts by mass of trimethylolpropane-modified toluene diisocyanate (manufactured by Toyo Chemical Co., Ltd., The product name is "BHS8515") mixed and fully stirred, and diluted with methyl ethyl ketone to obtain a coating solution of the adhesive composition. [chemical formula 3]

環氧基類：3-環氧丙氧基丙基三甲氧基矽烷（由信越矽利光公司所製造，產品名為「KBM-403」 巰基類：具有巰基的多官能基型矽烷偶合劑（由信越化學工業公司所製造，產品名為「X-12-1156」 [交聯劑（C）] 三羥甲基丙烷改性的甲苯二異氰酸酯（由東洋化學公司所製造，產品名為「BHS8515」 [活性能量射線硬化性成分（D）] ε-己內酯改性的參-（2-丙烯醯氧基乙基）異氰脲酸酯（由新中村化學公司所製造，產品名為「NK Ester A-9300-1CL」） [光聚合起始劑（E）] 1-羥基-環己基-苯基-酮和二苯甲酮的1：1（質量比）混合物 [防鏽劑] 1-[N，N-雙（2-乙基己基）胺基甲基]甲基苯并三唑Here, when the (meth)acrylate polymer (A) is set to 100 parts by mass (calculated by solid content), the various formulation amounts (calculated by solid content) of the adhesive composition are shown in Table 1 . In addition, details of the abbreviations, components, etc. described in Table 1 are as follows. [(Meth)acrylate polymer (A)] 2EHA: 2-ethylhexyl acrylate MMA: methyl methacrylate HEA: 2-hydroxyethyl acrylate IBXA: isocamphoryl acrylate ACMO: N-acryloyl mol Folin [silane coupling agent (B)] Structural formula (II): organosilicon compound represented by the above structural formula (II) Structural formula (III): organosilicon compound represented by the following structural formula (III) [Chemical formula 4]

Epoxy groups: 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Silicone Corporation, product name "KBM-403") Mercapto groups: multifunctional silane coupling agents with mercapto groups (manufactured by Shin-Etsu Chemical Co., Ltd., product name "X-12-1156" [Crosslinking agent (C)] Trimethylolpropane-modified toluene diisocyanate (manufactured by Toyo Chemical Co., Ltd., product name "BHS8515" [Active energy ray-curing component (D)] ε-caprolactone-modified ginseng-(2-acryloxyethyl) isocyanurate (manufactured by Shin-Nakamura Chemical Co., Ltd., product name "NK Ester A-9300-1CL") [Photopolymerization initiator (E)] 1:1 (mass ratio) mixture of 1-hydroxy-cyclohexyl-phenyl-ketone and benzophenone [rust inhibitor] 1- [N,N-bis(2-ethylhexyl)aminomethyl]methylbenzotriazole

3. Manufacture of adhesive sheet The coating solution of the adhesive composition obtained in the above step 2 is applied to one surface of the polyethylene terephthalate film using a silicone-based release agent using a knife coater. The peeling surface of the heavy-peeling type peeling sheet (manufactured by Lintec, product name "SP-PET 752150", thickness: 38 μm) obtained by the treatment was carried out at 80°C for 1 minute, and the Heat treatment was performed at 110° C. for 1 minute to form a coating layer (thickness: 50 μm).

Next, the coating layer on the heavy release type release sheet obtained above, and the light release type release sheet obtained by peeling one surface of the polyethylene terephthalate film using a silicone release agent Sheets (manufactured by Lintec Corporation, product name "SP-PET 381130") were attached to each other in such a way that the release-treated surface of the above-mentioned light-release type release sheet contacts the coating layer, and heated at 23°C, 50%RH Under the condition of aging for 7 days, an adhesive sheet with a structure of heavy release type release sheet/adhesive layer (thickness: 50 μm)/light release type release sheet was produced.

[Examples 2-8, Comparative Examples 1-4] In addition to the types and ratios of various monomers constituting the (meth)acrylate polymer (A), the weight average molecular weight of the (meth)acrylate polymer (A), the type and amount of the silane coupling agent (B), And the preparation amount of the crosslinking agent (C) was changed as shown in Table 1, and the adhesive sheet was manufactured in the same manner as in Example 1. In addition, in Examples 3 and 7, a rust preventive agent was further added, and in Examples 4, 5, 8, and Comparative Example 4, an active energy ray-curable component (D) and a photopolymerization initiator (E) were further added.

Here, the aforementioned weight average molecular weight (Mw) is a polystyrene-equivalent weight average molecular weight (GPC measurement) measured by gel permeation chromatography (GPC) under the following conditions. >Measurement conditions> ． GPC measuring device: manufactured by Tosoh Corporation, HLC-8020 ． GPC column (pass through in the following order): manufactured by Tosoh TSK guard column (guard column) HXL-H TSK gel GMHXL (×2) TSK gel G2000 HXL ． Measurement solvent: tetrahydrofuran (tetrahydrofuran) ． Measuring temperature: 40°C

[Test Example 1] (Measurement of Gel Fraction) The adhesive sheets obtained in the examples and comparative examples were cut into a size of 80mm×80mm, and the adhesive layer was wrapped in a polyester net (mesh size was 200), and its mass was weighed with a precision balance. And by deducting the mass of the polyester net itself, the mass of only the adhesive is calculated. The mass at this time is set to M1.

Next, the adhesive wrapped in the polyester mesh was immersed in ethyl acetate at room temperature (23° C.) for 24 hours. Afterwards, the adhesive was taken out, air-dried for 24 hours in an environment with a temperature of 23° C. and a relative humidity of 50%, and further dried in an oven at 80° C. for 12 hours. After drying, weigh its mass with a precision balance, and calculate the mass of only the adhesive by subtracting the mass of the polyester net itself. The mass at this time is set to M2. The gel fraction (%) is represented by (M2/M1)×100. The results are shown in Table 2.

In addition, for the adhesive sheets of Examples 4, 5, 8, and Comparative Example 4, the gel fractions before and after irradiating the adhesive layer with ultraviolet rays (UV) (irradiation from the side of the heavy-release type release sheet) were measured. The irradiation conditions of ultraviolet rays are as follows.

>UV irradiation conditions> . Use high pressure mercury lamps. The illuminance is 200mW/cm ² , and the light quantity is 1000mJ/cm ² . UV illumination. Using "UVPF-A1" manufactured by Eye Graphics

[Test Example 2] (Evaluation of resistance value change) >Production of silver wiring electrode plate> On an easy-adhesive treatment surface of a polyethylene terephthalate (PET) film (manufactured by Toray, product name "Lumirror U48", thickness: 125μm) with an easy-adhesive treatment, Silver paste (manufactured by Toyo Chemical Co., Ltd., product name "RA FS 088") was coated into the pattern shown in Figure 3 by screen printing. Thereafter, the silver paste was hardened by heat treatment at 135° C. for 30 minutes, and an electrode plate (a silver wiring electrode plate) having silver wiring was obtained.

As shown in FIG. 3 , the silver wiring is formed of a first silver wiring 9 a having six comb-tooth portions 91 a and a second silver wiring 9 b also having six comb-tooth portions 91 b on the PET film 8 . Here, the gap part 92a is formed between the six comb-tooth parts 91a in the 1st silver wiring 9a, and the gap part 92b is formed between the six comb-tooth parts 91b of the 2nd silver wiring 9b similarly. The five comb-tooth portions 91a in the first silver wiring 9a are each located in the gap portion 92b of the second silver wiring 9b, and the five comb-tooth portions 91b in the second silver wiring 9b are each located in the first silver wiring 9a. The first silver wiring 9a and the second silver wiring 9b are formed in the gap portion 92a. The six comb-tooth portions 91a in the first silver wiring 9a are connected by a connection portion 93a, and electrode pads 94a serving as terminals are provided on the connection portion 93a. Similarly, the six comb-tooth portions 91b in the second silver wiring 9b are connected by a connection portion 93b, and electrode pads 94b serving as terminals are provided on the connection portion 93b.

The line widths of the six comb-tooth portions 91a in the first silver wiring 9a and the line widths of the six comb-tooth portions 91b in the second silver wiring 9b are each 40 μm, and the adjacent comb-tooth portions 91a and comb teeth The distance between the portions 91b is 40 μm.

>Manufacturing of measurement samples> Soda-lime glass (length 70 mm x width 150 mm x thickness 1.0 mm; manufactured by Nippon Plate Glass Co., Ltd.), and ITO vapor-deposited film (by Tai The product name is "Tetrait TCF KH150NMH2-125-U6/T2" manufactured by Iike Industry Co., Ltd., and the side of the ITO vapor-deposited film is in contact with the adhesive layer) and bonded together. Thereafter, autoclaving was performed for 20 minutes under the conditions of 50° C. and 0.5 MPa to obtain a measurement sample A (ITO vapor-deposited film sample).

Furthermore, soda lime glass (length 70 mm x width 150 mm x thickness 1.0 mm; manufactured by Nippon Plate Glass Co., Ltd.), and the above-mentioned The silver wirings of the silver wiring electrode plate obtained in the step are bonded to each other. At this time, the bonding is performed so that the electrode pads 94a and 94b of the silver wirings 9a and 9b are exposed. Thereafter, autoclaving was performed for 20 minutes under conditions of 50° C. and 0.5 MPa to obtain a measurement sample B (silver wiring electrode plate sample).

In addition, for the adhesive sheets of Examples 4, 5, 8 and Comparative Example 4, after the above-mentioned autoclaving treatment, under the same conditions as Test Example 1, the adhesive layer was irradiated with ultraviolet rays from the soda lime glass side, and the This serves as a measurement sample.

For the above measurement sample A, an initial resistance value R ⁰ (Ω) was measured using a non-contact resistance measuring device (manufactured by Napson Corporation, product name "EC-80"). On the other hand, for the above-mentioned measurement sample B, an initial resistance value R ⁰ (Ω) was measured by applying a voltage of 5 V between the electrode pads 94 a and 94 b of the silver wirings 9 a and 9 b.

Next, the above measurement samples A and B were left in a humid heat environment of 85° C. 85% RH or in a high temperature environment of 95° C. for 1000 hours. Thereafter, it was allowed to stand for 24 hours under a normal temperature and normal humidity environment of 23° C. 50% RH, and a resistance value (Ω) was measured in the same manner as the initial resistance value described above. Let this be the resistance value R after the durability test. From the measured values obtained, the resistance value change rate (%) was calculated by the following formula. The results are shown in Table 2. Resistance value change rate (%)={(RR ⁰ )/R ⁰ }×100

Next, with respect to the rate of change in resistance value calculated as described above, the rate of change in resistance value was evaluated on the basis of the following criteria. The results are shown in Table 2. >Evaluation criteria for ITO vapor-deposited film samples> ◎: Resistance value change rate is less than 300% ○: Resistance value change rate is more than 300% and less than 350% △: Resistance value change rate is more than 350% and less than 400% ×: Resistance value change rate is 400% or more >Evaluation criteria for silver wiring electrode plate samples> ◎: Resistance value change rate is less than 10% ○: Resistance value change rate is 10% or more and less than 30% △: Resistance value change rate is more than 30% and less than 50% ×: Resistance value change rate is 50% or more

[Test Example 3] (Measurement of Adhesive Force) The light-peeling release sheet was peeled off from the adhesive sheets obtained in Examples and Comparative Examples, and the thus exposed adhesive layer was bonded to a polyethylene terephthalate (PET) film having an easy-adhesive layer ( Manufactured by Toyobo Co., Ltd., product name "PET A 4300"), thickness: 100μm) easy-adhesive layer, and then obtain a laminate of release sheet/adhesive layer/PET film. The obtained laminate was cut into a width of 25 mm and a length of 100 mm, and this was used as a sample.

In an environment of 23°C and 50% RH, the heavy peeling type release sheet was peeled from the above laminate, and the adhesive layer thus exposed was attached to soda lime glass (manufactured by Nippon Plate Glass Co., Ltd.) using Kurihara An autoclave manufactured by Seisakusho Co., Ltd. was pressurized at 0.5 MPa and 50° C. for 20 minutes. After that, after standing at 23°C and 50% RH for 24 hours, the adhesion was measured at a peeling speed of 300 mm/min and a peeling angle of 180 degrees using a tensile tester (Tensilon manufactured by ORIENTEC Co., Ltd.) Force (N/25mm). Conditions other than those described here were measured in accordance with JIS Z0237:2009. The results are shown in Table 2.

In addition, for the adhesive sheets of Examples 4, 5, 8 and Comparative Example 4, the adhesive force after ultraviolet (UV) irradiation was also separately measured. Specifically, after the above-mentioned autoclaving treatment, under the same conditions as in Test Example 1, the adhesive layer was irradiated with ultraviolet rays from the side of the soda lime glass. Thereafter, it was allowed to stand under the conditions of 23° C. and 50% RH for 24 hours, and the adhesive force (N/25 mm; after UV irradiation) was measured in the same manner as above. The results are shown in Table 2.

[Test Example 4] (Evaluation of Humid Heat Whitening Resistance) The adhesive layers of the adhesive sheets obtained in Examples and Comparative Examples were interposed between alkali-free glass with a thickness of 1.1 mm and an acrylic resin plate made of polymethyl methacrylate (PMMA) with a thickness of 1 mm. (manufactured by Mitsubishi Rayon Corporation, the product name is "Acrylite MR-200") to obtain a laminate.

The obtained laminate (sample) was autoclaved at 50° C. and 0.5 MPa for 20 minutes, and then left to stand at normal pressure at 23° C. and 50% RH for 24 hours. For this laminate, a haze value (%) was measured in accordance with JIS K7136:2000 using a haze meter (manufactured by Nippon Denshoku Kogyo Co., Ltd., product name "NDH2000"). In addition, for the adhesive sheets of Examples 4, 5, 8 and Comparative Example 4, ultraviolet rays were irradiated to the adhesive layer from the alkali-free glass side under the same conditions as in Test Example 1 after the above-mentioned autoclaving treatment.

Next, the above laminate was stored in a humid heat environment of 85° C. and 85% RH for 120 hours. Thereafter, it was allowed to stand at room temperature at 23° C., 50% RH, and normal humidity for 24 hours. For this laminate, a haze value (%) was measured in accordance with JIS K7136:2000 using a haze meter (manufactured by Nippon Denshoku Kogyo Co., Ltd., product name "NDH2000").

Based on the above results, the haze value before the damp heat condition was subtracted from the haze value after the damp heat condition to calculate the increase (percentage point) of the haze value after the damp heat condition. Based on this result, the moist heat whitening resistance was evaluated according to the following criteria. The results are shown in Table 2. ◎: Increase in haze value is less than 1.0 percentage points ○: Increase in haze value is 1.0% or more and less than 3.0% △: The increase of the haze value is more than 3.0 percentage points and less than 5.0 percentage points ×: The increase in the haze value is 5.0% or more

[Test Example 5] (Evaluation of Durability) The measurement samples A and B obtained in the above Test Example 2 (evaluation of resistance value change) were left in a humid heat environment of 85°C and 85%RH or in a high temperature environment of 95°C for 1000 hours. Thereafter, it was left to stand for 24 hours under a normal temperature and normal humidity environment of 23° C. 50% RH. Thereafter, whether bubbles, floating, or peeling occurred at the interface between the adhesive layer and the adherend was visually checked, and the durability was evaluated according to the following criteria. The results are shown in Table 2. ⊚: There are no bubbles, floating or peeling at all. ◯: Bubbles with a diameter of 0.1 mm or less are slightly generated. Δ: Many bubbles with a diameter of 0.1 mm or less are generated. ×: Bubbles, floating or peeling with a diameter of more than 0.1 mm were generated.

[Table 1] (meth)acrylate polymer (A) Silane coupling agent (B) Crosslinking agent (C) Active energy ray hardening ingredient (D) Photopolymerization initiator (E) Rust inhibitor Element mw type parts by mass parts by mass parts by mass parts by mass parts by mass Example 1 2EHA/MMA/HEA=60/20/20 700,000 Structural formula (II) 0.25 0.23 - - - Example 2 0.50 0.23 - - - Example 3 0.25 0.60 - - 0.30 Example 4 2EHA/IBXA/ACMO/HEA=65/15/5/15 500000 0.28 0.15 5.0 0.50 - Example 5 0.56 0.15 5.0 0.50 - Example 6 2EHA/MMA/HEA=60/20/20 700,000 Structural formula (Ⅲ) 0.25 0.23 - - - Example 7 0.25 0.60 - - 0.30 Example 8 2EHA/IBXA/ACMO/HEA=65/15/5/15 500000 0.25 0.15 5.0 0.50 - Comparative example 1 2EHA/MMA/HEA=60/20/20 700,000 - - 0.23 - - - Comparative example 2 Epoxy 0.25 0.23 - - - Comparative example 3 Thiols 0.25 0.23 - - - Comparative example 4 2EHA/IBXA/ACMO/HEA=65/15/5/15 500000 - - 0.15 5.0 0.5 -

[Table 2] Gel fraction (%) Change of resistance value Adhesion (N/25mm) Moisture and heat whitening resistance Durability ITO evaporation film Silver wiring electrode plate ITO evaporation film Silver wiring electrode plate UV not irradiated After UV irradiation 85°C. 85%RH 95°C 85°C. 85%RH 95°C UV not irradiated After UV irradiation 85°C. 85%RH 95°C 85°C. 85%RH 95°C Change rate (%) evaluate Change rate (%) evaluate Change rate (%) evaluate Change rate (%) evaluate Example 1 73 - 280 ◎ 10 ◎ >10 ◎ >10 ◎ 20 - ◎ ◎ ◎ ◎ ◎ Example 2 73 - 280 ◎ 20 ◎ >10 ◎ >10 ◎ 19 - ◎ ◎ ◎ ◎ ◎ Example 3 72 - 240 ◎ 70 ◎ >10 ◎ 20 ○ 20 - ◎ ◎ ◎ ◎ ○ Example 4 52 70 210 ◎ 10 ◎ >10 ◎ >10 ◎ 40 44 ◎ ◎ ◎ ◎ ◎ Example 5 52 69 200 ◎ 10 ◎ >10 ◎ >10 ◎ 40 43 ◎ ◎ ◎ ◎ ◎ Example 6 72 - 280 ◎ 10 ◎ 10 ○ >10 ◎ twenty two - ◎ ◎ ◎ ◎ ◎ Example 7 73 - 250 ◎ 50 ◎ 20 ○ 30 △ 20 - ◎ ◎ ◎ ◎ ○ Example 8 52 70 230 ◎ 20 ◎ 10 ○ >10 ◎ 40 44 ◎ ◎ ◎ ◎ ◎ Comparative example 1 72 - >400 x 10 ◎ 60 x 40 △ 25 - △ ○ ○ △ △ Comparative example 2 73 - >400 x 50 ◎ 40 △ 20 ○ 25 - ○ ○ ◎ ○ ◎ Comparative example 3 74 - >400 x 20 ◎ >400 x >400 x 27 - ○ ○ ◎ ○ ◎ Comparative example 4 53 70 >400 x 90 ◎ 190 x 20 ○ 41 46 △ ○ ○ ○ ○

As can be seen from Table 2, according to the adhesive sheet obtained in the example, the change in the resistance value of the ITO vapor-deposited film and the silver wiring electrode plate can be suppressed. Furthermore, the adhesive sheet obtained in the examples has excellent heat-and-moisture whitening resistance and durability. [Industrial Utilization]

The adhesive composition, adhesive and adhesive sheet according to the present invention can be applied to, for example, a capacitive touch panel. Furthermore, the display body according to the present invention is suitable as, for example, a capacitive touch panel.

1: Adhesive sheet 11: Adhesive layer 12a, 12b: Peeling sheet 2: Touch panel 3: Display body module 4: Adhesive layer 5a: 1st membrane sensor 5b: Second membrane sensor 51: Substrate film 52: electrode 6: Covering material 7: Printing layer 8: PET film 9a: 1st silver wiring 9b: 2nd silver wiring 91a, 91b: comb teeth 92a, 92b: gap part 93a, 93b: connection part 94a, 94b: electrode pads

[ Fig. 1 ] is a cross-sectional view of an adhesive sheet according to an embodiment of the present invention. [FIG. 2] is a schematic cross-sectional view of a structure example of a touch panel. [ Fig. 3 ] It is a plan view of a silver wiring electrode plate used in Test Example 2.

1: Adhesive sheet

11: Adhesive layer

12a, 12b: Peeling sheet

Claims (8)

An adhesive composition comprising: a (meth)acrylate polymer (A); and a silane coupling agent (B) having an alkoxysilyl group at both ends, wherein the aforementioned (meth)acrylate polymer ( A) including 12% by mass to 35% by mass of hydroxyl-containing monomers as monomer units constituting the aforementioned polymer, wherein the aforementioned silane coupling agent (B) is a compound represented by the following general formula (I):

In the formula, R ¹ is a divalent hydrocarbon group that may have a nitrogen atom; in the formula, R ² ~ R ⁷ are each independently an alkyl group, and R ¹ in the aforementioned general formula (I) is one that does not have a sulfur atom on the main chain. 2-valent hydrocarbon group. The adhesive composition as described in Claim 1, wherein ^R in the aforementioned general formula (I) is an alkylene group containing 1 to 10 carbon atoms. The adhesive composition according to claim 1, comprising a crosslinking agent (C). The adhesive composition according to claim 1, wherein the (meth)acrylate polymer (A) does not include a carboxyl group-containing monomer as a monomer unit constituting the polymer. The adhesive composition as described in Claim 1 is an adhesive composition for forming an adhesive contacting an electrode made of metal or metal oxide. Obtained by cross-linking the adhesive composition described in any one of Claims 1 to 5 to the adhesive. An adhesive sheet, comprising: two peeling sheets; and an adhesive layer interposed between the aforementioned peeling sheets in a manner of contacting the peeling surfaces of the aforementioned two peeling sheets, wherein the aforementioned adhesive layer is the one described in item 6 of claim composed of adhesives. A display body comprising a first display structure component, a second display structure component, and an adhesive layer for bonding the first display structure component and the second display structure component together, Wherein the aforementioned first display structural member and/or the aforementioned second display structural member have electrodes made of metal or metal oxide on at least the surface of the bonding side, and wherein the aforementioned adhesive layer is as claimed in Claim 7 The adhesive layer of the adhesive sheet.

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