TW201446911A - Optical adhesive composition, optical adhesive sheet and method for producing the same - Google Patents

Abstract

The present invention relates to an optical adhesive composition comprising (A) 100 part by weight of an acrylic copolymer substantially not containing carboxy group, (B) 0.3 part by weight or more and 20 part by weight or less of a compound having 2 or more cyclopropyl groups and having a molecular weight of 1000 or less.

Description

Optical adhesive composition, optical adhesive sheet and method of producing the same

The present invention relates to an optical adhesive composition, an optical adhesive sheet, and a method for producing the same.

In recent years, image display devices have been used under a variety of uses and conditions, for example, not only at room temperature, at high temperatures, but also under severe conditions of high temperature and high humidity. The use in high temperature or high temperature and high humidity conditions may be, for example, use in a tropical area, inside a vehicle or inside an outdoor measuring instrument.

The optical film constituting the image display device shrinks in a high-temperature, high-humidity environment to cause dimensional change. When the optical film is dimensionally deformed, for example, even if the temperature condition or the humidity condition is changed, it is difficult to completely return to the original size. As a result, the adhesive layer may be cracked, peeled, and floated due to the influence of the stress generated by the dimensional change of the optical film.

Further, in recent years, for example, a metal oxide such as an ITO layer used in a transparent electrode has been used for an image display device. When the adherend contains a metal oxide, the metal oxide is corroded by the acid component, and the resistance value becomes high. The problem.

[Previous Technical Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2007-169329

The present invention provides an optical adhesive composition, an optical adhesive sheet, and a method for producing the same, which exhibit excellent durability under high temperature and high humidity conditions without corroding the adherend.

In order to solve such a problem, the inventors of the present invention have found that an adhesive composition having a specific component can be used, and an adhesive layer having excellent durability without corroding the adherend can be obtained.

1. An optical adhesive composition according to an aspect of the present invention, comprising: (A) 100 parts by mass of an acrylic polymer substantially free of a carboxyl group; and (B) having 2 or more propylene oxides in 1 molecule. The compound having a molecular weight of 1,000 or less has a mass ratio of 0.3 parts by mass or more and 20 parts by mass or less.

2. The optical adhesive composition according to the above 1, wherein the (A) acrylic polymer is a copolymer (A ₁ ) containing a monomer mixture of the following (a1) and (a2): A1) 60% by mass or more and 85% by mass or less of the (meth)acrylic acid alkyl ester monomer; (a2) 15% by mass or more and 40% by mass or less of the hydroxyl group-containing monomer (herein, the monomer mixture is set to be When the amount is 100% by mass, the total amount of the (a1) alkyl (meth)acrylate monomer and the (a2) hydroxyl group-containing monomer is 75 mass% or more and 100 mass% or less.

3. The optical adhesive composition according to the above 1 or 2, which further contains (C) an isocyanate crosslinking agent.

4. The optical adhesive composition according to the above 1, wherein the (A) acrylic polymer is a partial polymer (A ₂ ) containing a monomer mixture of the following (a1) and (a2): (a1) 60% by mass or more and 85% by mass or less of the (meth)acrylic acid alkyl ester monomer; (a2) 15% by mass or more and 40% by mass or less of the hydroxyl group-containing monomer (here, the monomer mixture is provided) When it is 100% by mass, the total amount of the (a1) alkyl (meth)acrylate monomer and the (a2) hydroxyl group-containing monomer is 75 mass% or more and 100 mass% or less.

5. The optical adhesive composition according to the above 4, wherein the composition containing the partial polymer (A ₂ ) further contains (E) a polyfunctional monomer, and the (A) acrylic polymer may be used. It is obtained from the above composition containing the above partial polymer (A ₂ ) and the above (E) polyfunctional monomer.

The optical adhesive composition according to any one of the above-mentioned items, wherein the monomer mixture further contains 0.1% by mass or more and 5% by mass or less of the (a3) nitrogen atom-containing monomer.

7. The optical adhesive composition according to any one of the above 1 to 6, wherein the gel fraction may be 20% or more and 95% or less.

8. The optical adhesive according to any one of the above 1 to 7 The composition of the composition can be used in the bonding of the members constituting the touch panel type input and output device.

9. The optical adhesive sheet according to another aspect of the invention, comprising the adhesive layer obtained from the optical adhesive composition according to any one of the above 1 to 7.

10. A method of producing an optical adhesive sheet according to another aspect of the present invention, comprising the steps of: applying an adhesive composition to a surface of a separator to obtain a coating liquid layer; and coating from the foregoing The liquid layer is removed from the solvent layer and cured to obtain an optical adhesive sheet; wherein the adhesive composition contains (A) 100 parts by mass of the acrylic polymer substantially free of carboxyl groups and 2 molecules of (B) 1 molecule The compound having a molecular weight of 1,000 or less of the above epoxy propylene is 0.3 parts by mass or more and 20 parts by mass or less.

11. The method for producing an optical adhesive sheet according to the above 10, wherein the adhesive composition further contains (C) an isocyanate crosslinking agent.

12. A method of producing an optical adhesive sheet according to another aspect of the present invention, comprising the steps of: applying a coating liquid to a surface of a separator to obtain a coating liquid layer; and irradiating the coating liquid layer The step of obtaining an optical adhesive sheet containing 60% by mass or more and 85% by mass or less of the (a1) alkyl (meth) acrylate monomer and (a2) a hydroxyl group-containing monomer 15 100 parts by mass of the partial polymer (A ₂ ) of the monomer mixture of the mass% or more and 40% by mass or less (here, when the monomer mixture is 100% by mass, the aforementioned (a1) alkyl (meth)acrylate The total amount of the monomer and the (a2) hydroxyl group-containing monomer is 75 mass% or more and 100 mass% or less), and (B) the compound having two or more epoxy propyl groups having a molecular weight of 1,000 or less in a molecule of 0.3 parts by mass or less. The above and 20 parts by mass or less and (D) a photopolymerization initiator.

13. The method for producing an optical adhesive sheet according to the above 12, wherein the coating liquid further contains (E) a polyfunctional monomer.

The optical adhesive composition according to any one of the above 1 to 8, which comprises (A) 100 parts by mass of the acrylic polymer having substantially no carboxyl group, and (B) a molecular weight of 2 or more epoxy propyl groups in one molecule. 0.3 parts by mass or more and 20 parts by mass or less of the compound of 1,000 or less, and coating which has moderate adhesion, does not corrode the adherend, and exhibits excellent durability (moisture resistance) under high temperature conditions or high temperature and high humidity conditions is obtained. Liquid layer.

Moreover, since the optical adhesive sheet according to the above-mentioned item 9 has the adhesive layer obtained from the optical adhesive composition according to any one of the above 1 to 7, it has excellent durability and does not corrode the adherend. Therefore, the above-mentioned optical adhesive sheet can be suitably used for an image display device or an input/output device.

The method for producing an optical adhesive sheet according to the above 10 and 11 can be carried out by performing the following steps to carry out intramolecular and/or intermolecular reaction of the epoxy propyl groups with each other to obtain excellent durability without corroding the adherend. The optical adhesive sheet, the steps of: applying the adhesive composition to the surface of the separator to obtain a coating liquid layer; and removing the solvent from the coating liquid layer and aging to obtain an optical adhesive sheet Wherein the adhesive composition contains (A) an acrylic polymer 100 substantially free of carboxyl groups (B) a compound having a molecular weight of 1,000 or less having two or more epoxy propyl groups in one molecule, 0.3 parts by mass or more and 20 parts by mass or less, and an optional (C) isocyanate crosslinking agent.

Further, the method for producing an optical adhesive sheet according to any of the above 12 to 13 can be carried out by performing the following steps to carry out intramolecular and/or intermolecular reaction of the epoxy propyl groups with each other to obtain excellent durability without corrosion. An optical adhesive sheet for adhering a body, the steps of: applying a mixture to a surface of a separator to obtain a coating liquid layer; and irradiating the coating liquid layer to obtain an optical adhesive sheet, wherein The mixture contains a portion of a monomer mixture containing 60% by mass or more and 85% by mass or less of the (a1) alkyl (meth) acrylate monomer and 15% by mass or more and 40% by mass or less of the (a2) hydroxyl group-containing monomer. 100 parts by mass of the polymer (A ₂ ) (herein, when the monomer mixture is 100% by mass, the total of the (a1) alkyl (meth)acrylate monomer and the (a2) hydroxyl group-containing monomer described above (B) a compound having a molecular weight of 1,000 or less having two or more epoxy propyl groups in one molecule of 0.3 parts by mass or more and 20 parts by mass or less and (D) photopolymerization initiation in an amount of 7 mass% or more and 100 mass% or less. Agent.

10‧‧‧Liquid Crystal Display Unit (LCD)

11, 15‧‧‧ polarizing plate

12, 14, 17‧‧ ‧ adhesive layer

13‧‧‧LCD panel

16‧‧‧Smashproof film

18‧‧‧ITO layer

19‧‧‧ glass panel

20‧‧‧Touch Panel Department

30‧‧‧Adhesive layer

100‧‧‧Touch panel type input and output device

Fig. 1 is a cross-sectional view schematically showing the configuration of an input/output device (touch panel type input/output device) according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to the drawings. In the present invention, "parts" means "parts by mass", "%" unless otherwise specified. Means "% by mass".

Optical adhesive composition

An optical adhesive composition according to an embodiment of the present invention (hereinafter also referred to simply as "adhesive composition") contains: (A) an acrylic polymer substantially free of a carboxyl group (hereinafter, also In the case of "(A) component"), (B) a compound having two or more glycidyl groups having a molecular weight of 1,000 or less in one molecule (hereinafter, simply referred to as "(B) component") ) 0.3 parts by mass or more and 20 parts by mass or less.

In the present invention, the "acrylic polymer" refers to a polymerization in which at least one selected from the group consisting of acrylic acid, acrylate, acrylate, methacrylic acid, methacrylic acid salt, and methacrylic acid ester is contained in a constituent unit of 50% by mass or more. Things. Further, the "hydroxyl group-free acrylate monomer" means an acrylate monomer having no hydroxyl group in its molecular structure.

The adhesive composition of the present embodiment is (B) relative to the content of the component (A) from the viewpoint of imparting more excellent durability to the adhesive sheet formed using the adhesive composition of the present embodiment. The component content is preferably 0.3 parts by mass or more and 15 parts by mass or less, more preferably 0.3 parts by mass or more and 10 parts by mass or less based on 100 parts by mass of the component (A).

In the adhesive composition of the present embodiment, the content of the component (B) relative to the content of the component (A) is more than 20 parts by mass or less than 0.3 parts by mass based on 100 parts by mass of the component (A). When there is a situation where durability is poor.

1.1. (A) ingredients

In the present invention, the term "substantially free of a carboxyl group" means that the acid value is 1 or less, and more specifically, the monomer mixture of the raw material of the component (A) does not contain a monomer having a carboxyl group (the raw material of the component (A) The content of the carboxyl group-containing monomer in the monomer mixture is 0.1% by mass or less, preferably 0% by mass.

When the component (A) does not substantially contain a carboxyl group, it does not have corrosive properties to the adherend. In particular, since it does not corrode an adherend containing a metal such as ITO, it can be used for an output device such as an image display device or a touch panel without eroding a paste containing a metal such as ITO.

Further, the component (A) may contain a hydroxyl group. More specifically, when the monomer mixture of the raw material of the component (A) contains a hydroxyl group-containing monomer, the component (A) may contain a hydroxyl group. It is confirmed that the component (A) contains a hydroxyl group by, for example, adsorption in the range of 3400 cm ^-1 to 3200 cm ^-1 in the IR spectrum related to the component (A). When the component (A) contains a hydroxyl group and the hydroxyl group reacts with the component (C) described later, durability can be improved.

The component (A) may have (a1) an alkyl (meth)acrylate monomer as a main monomer. Here, the "alkyl (meth) acrylate monomer as a main monomer" means that the monomer contained in the monomer mixture of the raw material of the component (A) has the highest content of the alkyl (meth) acrylate monomer. By.

Further, the first copolymer and the second copolymer or any of them may be used as the component (A). The first copolymer is a copolymer (A ₁ ) containing a monomer mixture of a (meth)acrylic acid alkyl ester monomer as a main monomer, and the second copolymer contains a (meth)acrylic acid alkyl ester monomer as a main monomer. a partial copolymer (A ₂ ) of the monomer mixture.

1.1.1. (A ₁ ) component

The component (A ₁ ) may contain 60% by mass or more and 85% by mass or less (preferably 65% by mass or more and 84.9% by mass or less) of the (a1) alkyl (meth) acrylate monomer, and (a2) a hydroxyl group-containing one. a copolymer (A ₁ ) of a monomer mixture of 15% by mass or more and 40% by mass or less (preferably 15% by mass or more and 35% by mass or less) of the monomer (here, the monomer mixture is set to 100% by mass) In the case, the total amount of the (a1) alkyl (meth)acrylate monomer and the (a2) hydroxyl group-containing monomer is 75 mass% or more and 100 mass% or less.

The component (A ₁ ) can be used, for example, when the optical adhesive composition of the present embodiment is dissolved or dispersed in a solvent (H) (hereinafter, simply referred to as "(H) component"). Details (H) ingredients). In addition, when the (O ₁ ) component is contained in the optical adhesive composition of the present embodiment, the (C) isocyanate crosslinking agent (hereinafter referred to as "(C) component") may be further contained. .

When the composition of the present embodiment patterns of adhesive, a (A ₁₎ component as the component (A), with respect to 100 parts by mass of the composition according to the present embodiment patterns of adhesive compositions, the present embodiment patterns of adhesive in the The content of the component (A ₁ ) may be 80 parts by mass or more and 99.7 parts by mass or less, preferably 90 parts by mass or more and 99.5 parts by mass or less.

1.1.2. (A ₂ ) component

The component (A ₂ ) is contained in an amount of 60% by mass or more and 85% by mass or less based on the (a1) alkyl (meth) acrylate monomer (hereinafter, simply referred to as "(a1) component"). 65% by mass or more and 84.9% by mass or less) and (a2) a monomer having a hydroxyl group (hereinafter, abbreviated as "the component (a2)") is 15% by mass or more and 40% by mass or less (preferably 15 mass%) The composition of the partial polymer (A ₂ ) of the monomer mixture of % or more and 35% by mass or less) (here, when the monomer mixture is 100% by mass, the above (a1) (meth)acrylic acid The total amount of the alkyl ester monomer and the (a2) hydroxyl group-containing monomer is 75 mass% or more and 100 mass% or less.

The component (A ₂ ) can be used, for example, when the optical adhesive composition of the present embodiment is applied in a state where it is substantially free of a solvent. In the present invention, the "application of the optical adhesive composition in a state where the solvent is substantially not contained" means that the content of the solvent in the coating liquid containing the optical adhesive composition is 1% by mass or less. Specifically, it means a case where the solvent is not formulated in the coating liquid. The coating liquid containing the optical adhesive composition of the present embodiment can form a thick film adhesive layer easily without substantially containing a solvent.

In the adhesive composition of the present embodiment, when the component (A) is obtained from the component (A ₂ ), it is in the adhesive composition of the present embodiment with respect to 100 parts by mass of the adhesive composition of the present embodiment. The content of the component (A ₂ ) may be 80 parts by mass or more and 99.7 parts by mass or less, preferably 90 parts by mass or more and 99.5 parts by mass or less.

Further, from the viewpoint that the (A ₂ ) component can have an appropriate viscosity, the monomer content in the (A ₂ ) component (the ratio of the monomer remaining unpolymerized in the monomer used) is preferably 30% by mass. The above is 95% by mass or less, and more preferably 40% by mass or more and 80% by mass or less. Further, the polymer component contained in the component (A ₂ ) is preferably 5% by mass or more and 70% by mass or less, more preferably 20% by mass or more and 60% by mass or less.

Further, when the optical adhesive composition of the present embodiment contains the component (A ₂ ), the (C) isocyanate crosslinking agent (hereinafter referred to as "(C) component") may be substantially excluded. situation). In the present invention, the content of the component (C) in the optical adhesive composition is 0.1% by mass or less, and more specifically, Refers to the case where the component (C) is not formulated in the optical adhesive composition.

In addition, the monomer mixture which is a raw material of the (A ₂ ) component may further contain (a3) a monomer containing a nitrogen atom (hereinafter, abbreviated as "(a3) component)" 0.1% by mass or more and 5% by mass. the following. By the inclusion of the component (a3) in the monomer mixture, the whitening resistance of the adhesive layer formed by the adhesive composition of the present invention can be enhanced.

1.1.3. (a1) ingredients

The component (a1) contained in the monomer mixture of the raw material of the (A ₁ ) component and the (A ₂ ) component contributes to the adhesion and durability of the adhesive composition of the present embodiment.

(a1) The (meth)acrylic acid alkyl ester monomer may, for example, be methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-propyl acrylate, n-propyl methacrylate or acrylic acid. Butyl ester, n-butyl methacrylate, n-hexyl acrylate, n-hexyl methacrylate, n-amyl acrylate, n-octyl acrylate, n-octyl methacrylate, n-decyl acrylate, n-hexadecyl acrylate, methyl N-hexadecyl acrylate, stearyl acrylate, stearyl methacrylate, n-lauryl methacrylate, n-lauryl acrylate, n-tetradecyl methacrylate, etc. (meth)acrylic acid having a linear alkyl group Alkyl ester monomer; isopropyl acrylate, isobutyl acrylate, tert-butyl acrylate, isopropyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, isooctyl acrylate, methyl Isooctyl acrylate, C a (meth)acrylic acid alkyl ester monomer having a branched alkyl group such as 2-ethylhexyl olefin or 2-ethylhexyl methacrylate; cyclohexyl acrylate, cyclohexyl methacrylate, isophthalic acid acrylate The alkyl (meth) acrylate monomer having an alicyclic group such as an ester or isodecyl methacrylate; one of them may be used alone or two or more of them may be used in combination. Among them, the (a1) component is preferably a linear or branched alkane of an alkyl (meth)acrylate from the point that the durability of the adhesive sheet formed using the adhesive composition of the present embodiment is excellent. The alkyl (meth) acrylate monomer is more preferably a branched alkyl group. In this case, it is more preferable that the carbon number of the alkyl group is 1 or more and 20 or less (preferably 1 or more) from the viewpoint that the durability of the pressure-sensitive adhesive sheet formed using the pressure-sensitive adhesive composition of the present embodiment is more excellent. 10 or less, more preferably 1 or more and 8 or less.

1.1.4. (a2) ingredients

By the monomer mixture as a component of raw materials (A ₁₎ and the component (A ₂₎ contained in the component (a2), (A ₁₎ and the component (A ₂₎ may contain hydroxyl component. In this case, the hydroxyl group contained in the (A ₁ ) component and the (A ₂ ) component reacts with the isocyanate group contained in the component (C) described later, whereby a crosslinked structure can be formed.

The component (a2) may, for example, be 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate or cyclohexane. A hydroxyl group-containing (meth) acrylate monomer such as dimethanol monoacrylate or N-methylol acrylamide or N-hydroxyethyl acrylamide, wherein one type or two or more types may be used in combination. use. Among them, a (meth) acrylate monomer having a hydroxyalkyl group having 1 or more and 4 or less carbon atoms is preferred.

1.1.5. (a3) ingredients

By starting material monomer mixture of (A ₁₎ and the component (A ₂₎ component containing component (a3), (A ₁₎ and the component (A ₂₎ component may contain a nitrogen atom. The component (a3) may, for example, be a monomer containing a nitrogen atom containing at least one group selected from the group consisting of a nitrile group, an amine group, an imido group and a guanamine group.

More specifically, the component (a3) may, for example, be N,N-dimethylaminoethyl acrylate, N,N-dimethylaminoethyl methacrylate or N,N-diethyl methacrylate. Amino group-containing monomer such as arylaminoethyl ester, acrylamide, N,N-dimethyl decylamine, N,N-diethyl acrylamide, acryloyl morpholine, N-methoxy a guanamine-containing monomer such as methacrylamide, N-butoxymethyl acrylamide, N-tert-butyl acrylamide, N,N-dimethylaminopropyl acrylamide, and the like Acrylonitrile may be used alone or in combination of two or more. Among them, the (a3) component is more preferably a guanamine-containing monomer from the viewpoint of improving the whitening resistance of the adhesive layer formed of the adhesive composition of the present invention.

1.1.6. (a4) ingredients

Further, in order to obtain the monomer mixture as the polymer of the component (A), the monomer (a4) other than the component (a1), the component (a2) and the component (a3) may be further contained (hereinafter, simply referred to as " (a4) Ingredients"). The component (a4) may, for example, be vinyl acetate, styrene or a macromonomer.

1.1.7. Total amount of (a1) component, (a2) component and (a3) component

In the adhesive composition of the present embodiment, in order to obtain a good adhesion and durability more reliably, in order to obtain the aforementioned monomer mixture of the (A ₁ ) component or the (A ₂ ) component ( The total amount of the a1) component, the (a2) component, and the (a3) component (when the monomer mixture is 100% by mass) may be 90% by mass or more and 100% by mass or less, preferably 95% by mass or more and 100% by mass. Below mass%.

1.1.8. Polymerization method of (A ₁ ) component

The polymerization method of the component (A ₁ ) is not particularly limited, and it can be polymerized by a known method such as solution polymerization, emulsion polymerization or suspension polymerization, and a mixture of the copolymers obtained by polymerization can be used to produce the adhesive composition of the present invention. The treatment step is relatively simple and can be polymerized by solution polymerization from the viewpoint of carrying out in a short period of time.

The solution polymerization is generally carried out by feeding a specific organic solvent, each monomer, a polymerization initiator, and a chain transfer agent or the like as needed, in a polymerization tank, and stirring at a reflux temperature of a nitrogen stream or an organic solvent. The heating reaction is carried out for several hours.

Further, in this case, at least a part of the organic solvent, the monomer, and/or the polymerization initiator may be added one by one. Examples of the organic solvent include benzene, toluene, ethylbenzene, n-propylbenzene, t-butylbenzene, o-xylene, m-xylene, p-xylene, tetrahydronaphthalene, decahydronaphthalene, and aromatic petroleum brain. Aromatic hydrocarbons; for example, n-hexane, n-heptane, n-octane, isooctane, n-decane, dipentene, petroleum spirit, petroleum brain, turpentine, and the like, or aliphatic or alicyclic hydrocarbons; For example, ethyl acetate, n-butyl acetate, n-amyl acetate, 2-hydroxyethyl acetate, 2-butoxyethyl acetate, 3-methoxybutyl acetate, methyl benzoate, etc.; a ketone such as methyl ethyl ketone, methyl isobutyl ketone, isophorone, cyclohexanone or methylcyclohexanone; for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl a glycol ether such as ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether or diethylene glycol monobutyl ether; For example, alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, second butanol, and third butanol; and the like. These organic solvents may be used alone or in combination of two or more.

In the polymerization of the (A ₁ ) component in the organic solvent for polymerization, it is preferred to use an organic solvent which is less likely to cause chain transfer during the polymerization reaction, such as an ester or a ketone, and in particular, the solubility of the component (A ₁ ). From the viewpoints of easiness of polymerization reaction, etc., ethyl acetate, methyl ethyl ketone, acetone or the like is preferably used.

As the polymerization initiator, an organic peroxide, an azo compound or the like which can be used in general solution polymerization can be used. Such an organic peroxide may, for example, be a tert-butyl hydroperoxide, cumene hydroperoxide, dicumyl peroxide, benzammonium peroxide, laurel peroxide, hexanyl peroxide, or Diisopropyl oxydicarbonate, di-2-ethylhexyl peroxydicarbonate, tert-butyl peroxytrimethylacetate, 2,2-bis(4,4-di-t-butylperoxy) Cyclohexyl)propane, 2,2-bis(4,4-di-p-pentylperoxycyclohexyl)propane, 2,2-bis(4,4-di-t-octylperoxycyclohexyl)propane 2,2-bis(4,4-di-α-isopropylphenylperoxycyclohexyl)propane, 2,2-bis(4,4-di-tert-butylperoxycyclohexyl)butane, 2,2-bis(4,4-di-th-octylperoxycyclohexyl)butane, etc., and an azo compound, for example, 2,2'-azobis-isobutyronitrile, 2,2'- Azobis-2,4-dimethylvaleronitrile, 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, and the like.

The amount of the polymerization initiator to be used is usually 0.01 parts by mass or more and 2 parts by mass or less, preferably 0.02 parts by mass or more and 1.0 parts by mass or less, based on 100 parts by mass of the total of the monomers.

Further, when the (A ₁ ) component contained in the adhesive composition of the present invention is produced, a chain transfer agent may be used as needed within the range not impairing the object and effect of the present invention.

Such a chain transfer agent may, for example, be cyanoacetic acid; an alkyl ester having a carbon number of 1 or more and 8 or less; a bromoacetic acid; an alkyl ester having a carbon number of 1 or more and 8 or less; An aromatic compound such as 9-phenylindole; an aromatic nitro group such as p-nitroaniline, nitrobenzene, dinitrobenzene, p-nitrobenzoic acid, p-nitrophenol or p-nitrotoluene a compound; a benzoquinone derivative such as benzoquinone, 2,3,5,6-tetramethyl-p-benzoquinone; a borane derivative such as tributylborane; carbon tetrabromide, carbon tetrachloride, 1 , 1,2,2-tetrabromoethane, tribromoethylene, trichloroethylene, bromotrichloromethane, tribromomethane, 3-chloro-1-propene and other halogenated hydrocarbons; aldehydes such as chloral and furfural; carbon number Alkyl mercaptans of 1 to 18; aromatic thiols such as thiophenol and toluene thiol; alkyl esters having 1 or more and 10 or less carbon atoms of thioglycolic acid and thioglycolic acid; and hydroxyalkanes having 1 or more and 12 or less carbon atoms Base thiols; terpenes such as pinene and terpinolen;

The polymerization temperature of the component (A ₁ ) is usually about 30 ° C or more and 180 ° C or less, preferably 40 ° C or more and 150 ° C or less, more preferably 50 ° C or more and 100 ° C or less. Further, when the polymer obtained by the solution polymerization method or the like contains an unreacted monomer, it may be purified by a reprecipitation method using methanol or the like to remove the monomer.

1.1.9. Polymerization method of (A ₂ ) component

A part of the polymer as the component (A ₂ ) can be obtained by partially polymerizing in such a manner as to become a viscosity of the coatable monomer mixture. For example, Japanese Laid-Open Patent Publication No. 2001-181589, the (A ₂ ) component can be produced by the method described in JP-A-2001-181589.

More specifically, the production of the (A ₂ ) component is preferably carried out using bulk polymerization. In the bulk polymerization for producing a partial polymer as the component (A ₂ ), the monomer mixture is reacted substantially without using a solvent. In this case, in the bulk polymerization, it is preferred to polymerize using the specific polymerization initiator shown below. The polymerization initiator used herein is as follows. It is preferred to use a polymerization initiator having a 10-hour half-life temperature of 41.0 ° C or less, preferably 20 ° C or more and 37.0 ° C or less.

Examples of such a polymerization initiator include isobutyl sulfoxide (10-hour half-life temperature: 32.7 ° C) and α, α'-bis (peroxide neodymium) diisopropylbenzene (10-hour half-life temperature: 35.9 ° C), cumene peroxy neodecanoate (10-hour half-life temperature: 36.5 ° C), di-n-propyl peroxydicarbonate (10-hour half-life temperature: 40.3 ° C), diisopropyl peroxydicarbonate ( 10-hour half-life temperature: 40.5 ° C), dibutyl peroxydicarbonate (10-hour half-life temperature: 40.5 ° C), peroxy neodecanoic acid 1,1,3,3-tetramethylbutyl ester (10-hour half-life) Temperature: 40.7 ° C), bis(4-butylcyclohexyl)peroxydicarbonate (10-hour half-life temperature: 40.8 ° C) and 2,2'-azobis(4-methoxy-2,4-di Methylvaleronitrile) (10 hour half-life temperature: 30.0 ° C). These polymerization initiators may be used singly or in combination. Among these, it is preferred to use isobutyl sulfoxide (10-hour half-life temperature: 32.7 ° C), α, α'-bis (peroxidized neodymium) diisopropylbenzene (10-hour half-life temperature: 35.9 ° C) , cumene peroxy neodecanoate (10-hour half-life temperature: 36.5 ° C), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) (10-hour half-life temperature) : 30.0 ° C).

In such a method, when the polymerization initiator is formulated, the monomer mixture is heated or warmed to a temperature at which polymerization can be carried out, and the above-mentioned specific amount of the above specific reaction initiator is added to the monomer mixture to carry out a polymerization reaction. The temperature of the monomer mixture when the polymerization initiator is added is usually 20° C. or higher and 80° C. or lower, preferably 35° C. or higher and 70° C. or lower, and particularly preferably 40° C. or higher and 65° C. or lower. In the thus heated or warmed monomer mixture, a polymerization initiator is generally added under stirring.

By reacting in this manner, a part of the polymer polymerized in an amount of 5 mass% or more and 70 mass% or less of the monomer in the monomer mixture of the feed can be obtained.

1.1.10. Tg

In the adhesive composition of the present embodiment, the Tg of the component (A ₁ ) is preferably -70 ° C or more and 0 ° C or less from the viewpoint of more reliably achieving good adhesion and durability, and more preferably and less than -60 ℃ 0 ℃, Tg (A ₂₎ of the component (obtained from the polymerization of the polymer (A ₂₎ component Tg) less than -70 ℃ preferred based and 0 ℃, more preferably above -60 ℃ based And below 0 °C.

Further, in the present invention, the Tg of the (A ₁ ) component and the (A ₂ ) component is a value calculated by the following formula (1) (FOX formula).

1/Tg _A = W _a1 /Tg _a1 +W _a2 /Tg _a2 +W _a3 /Tg _a3 +W _a4 /Tg _a4 ......(1)

(wherein, Tg _A represents the glass transition temperature (K) of the component (A), and Tg _a1 , Tg _a2 , Tg _a3 , and Tg _a4 represent the constituent units (a1), (a2), (a3), and (a4), respectively. The glass transition temperature (Tg(K)) of the prepared homopolymer, W _a1 , W _a2 , W _a3 , W _a4 respectively represent the constituent units (a1), (a2), (a3) contained in the component (A). ), (a4) weight fraction)

Further, the Tg _A system is calculated from the above formula (1) in the form of an absolute temperature (K), and is converted to Celsius temperature (° C.) as necessary.

Further, the glass transition temperature of the homopolymer prepared by the representative monomer is shown in the following Table 1, and more specifically, it is described, for example, in the Polymer Handbook Fourth Edition (Wiley-Interscience 2003). Wait.

1.1.11. Weight average molecular weight (Mw)

Further, in the adhesive composition of the present embodiment, the (A ₁ ) component preferably has a weight average molecular weight (Mw) of 100,000 or more and 150 from the viewpoint of more reliably achieving good adhesion and durability. More preferably, the amount of the polymer component in the component (A ₂ ) is preferably 10,000 or more and 1,000,000 or less, more preferably 30,000 or more and 50 or less. Less than 10,000. Here, the weight average molecular weight (Mw) of the (A ₁ ) component and the (A ₂ ) component is determined by GPC (gel permeation chromatography), and the weight average molecular weight (Mw) in terms of styrene is determined under the following conditions.

<GPC measurement conditions>

Measuring device: HLC-8120GPC (manufactured by TOSOH Co., Ltd.)

GPC column structure: the following 5 connected columns (all manufactured by TOSOH)

(1) TSK-GEL HXL-H (guard column)

(2)TSK-GEL G7000HXL

(3)TSK-GEL GMHXL

(4)TSK-GEL GMHXL

(5)TSK-GEL G2500HXL

Sample concentration: diluted with tetrahydrofuran to 1.0 mg/cm ³

Mobile phase solvent: tetrahydrofuran

Flow rate: 1.0cm ³ / minute

Column temperature: 40 ° C

1.2. (B) ingredients

By constructing a crosslinked structure more reliably in the molecule and/or between the molecules of the component (B), from the viewpoint of imparting superior durability to the adhesive sheet formed using the adhesive composition of the present embodiment, , (B) component 1 molecule The number of the epoxy propyl groups to be contained is preferably 2 or more and 8 or less, more preferably 2 or more and 6 or less.

Further, the molecular weight of the component (B) is preferably 100 or more and 1,000 or less, and may be, for example, 100 or more and 600 or less. When the molecular weight of the compound having two or more epoxy propyl groups in one molecule exceeds 1,000, the compatibility between the component (B) and the component (A) is deteriorated, and the density of the epoxy propyl group is further reduced to cause the epoxy. The propyl groups are difficult to react with each other, and as a result, it is difficult to form a crosslinked structure, so that durability is poor.

The component (B) may, for example, be 1,6-hexanediolepoxypropyl ether or 1,4-butanediol diepoxypropyl ether. The commercially available component (B) may, for example, be TETRAD C (Mitsubishi Gas Chemical Co., Ltd.), TETRAD X (Mitsubishi Gas Chemical Co., Ltd.), DENACOL (Nagase ChemteX Co., Ltd.), or the like.

1.3. (C) ingredients

In the adhesive composition of the present embodiment, the isocyanate-based crosslinking agent as the component (C) is not particularly limited as long as it is a crosslinking agent which can be crosslinked with the component (A) at normal temperature or under heating, and examples thereof include benzene. Dimethyl diisocyanate, toluene diisocyanate, chlorophenyl diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane An isocyanate compound such as an isocyanate or an isocyanate compound or an isomeric cyanurate compound which is subjected to an addition reaction with an alcohol compound having two or more members such as trimethylolpropane. The commercially available component (C) may, for example, be CORONATE L (Japan Polyurethane Industry Co., Ltd.), DURANATE 24A-100 (Asahi Kasei Co., Ltd.), TAKENATE D-120N (Mitsui Chemical Co., Ltd.), MITEC NY260A (Mitsubishi Chemical Co., Ltd.), etc.

Further, a known urethane prepolymer which is subjected to an addition reaction with an isocyanate compound, such as a polyether polyol or a polyester polyol, an acrylic polyol, a polybutadiene polyol, or a polyisoprene polyol, may be mentioned. Type of isocyanate and the like. Among these, phthalic diisocyanate, a derivative thereof and the like are preferably used.

From the viewpoint of achieving a specific gel fraction (for example, 20% or more and 95% or less), the content of the component (C) in the adhesive composition of the present embodiment is 100 parts by mass of the component (A). It may be 0.1 part by mass or more and 5 parts by mass or less, preferably 0.1 part by mass or more and 3 parts by mass or less.

1.4. (D) ingredients

The photopolymerization initiator as the component (D) is contained in an adhesive composition containing the component (A ₂ ) and the component (B) described later, and has a reaction initiation when the adhesive composition is used to form an adhesive sheet. The function of the agent. The content of the component (D) in the optical adhesive composition of the present embodiment is preferably 0.05 parts by mass or more and 5 parts by mass or less, more preferably 0.1 parts by mass or more, based on 100 parts by mass of the (A ₂ ) component. And 3 parts by mass or less. The component (D) is preferably, for example, an ultraviolet polymerization initiator which starts polymerization by ultraviolet rays.

The component (D) may, for example, be 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl ketone, 2-hydroxy-1-{4 -[4-(2-hydroxy-2-methyl-propenyl)-benzyl]phenyl}-2-methyl-propan-1-one, 2-hydroxy-2-methyl-1-benzene Base-propan-1-one, 1-[4-(2-hydroxyethoxy)-benzene 2-hydroxy-2-methyl-1-propan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-(N-morpholinyl)propane 1- Ketone, 2-Benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butanone-1,6-trimethylbenzimidyldiphenylphosphine oxide , benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1, 2-diphenylethane-1-one, anisole methyl ether, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1- Hydroxycyclohexyl phenyl ketone, 4-phenoxydichloroacetophenone, 4-tert-butyl-dichloroacetophenone, 2-naphthalenesulfonium chloride, 1-phenyl-1,1-propanedione -2-o-ethoxycarbonyl)-indole, benzoin, diphenylethylenedione, benzophenone, benzhydrylbenzoic acid, 3,3'-dimethyl-4-methoxy Benzene, polyethylene benzophenone, α-hydroxycyclohexyl phenyl ketone, benzyl dimethyl ketal, thioxanthone, 2-chlorothioxanthone, 2-methyl thioxanthone, 2, 4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, ten Dialkyl thio Ketones. Such photopolymerization initiators may be used singly or in combination.

1.5. (E) component

The component (E) is a monomer having two or more (meth) acrylonitrile groups. The polyfunctional monomer as the component (E) may be contained in the adhesive composition containing the component (A ₂ ) and the component (B). The adhesive composition comprises the component (E), and in the adhesive layer formed by the adhesive composition, the component (E) reacts with the monomer in the component (A ₂ ) to form a crosslinked structure. This makes it possible to obtain an adhesive sheet which is more excellent in durability. The content of the component (E) in the optical adhesive composition of the present embodiment is preferably 0.01 parts by mass or more and 10 parts by mass or less, more preferably 0.01 parts by mass or more, based on 100 parts by mass of the (A ₂ ) component. And 5 parts by mass or less.

The component (E) may, for example, be neopentyl alcohol di(meth)acrylate, neopentyl alcohol tri(meth)acrylate, neopentyltetrakis(meth)acrylate or dipentaerythritol. (Meth) acrylate, 1,2-ethanediol di(meth) acrylate, 1,6-hexanediol di(meth) acrylate, 1,12-dodecanediol di(methyl) ) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylol methane tri (meth) acrylate, divinyl benzene, urethane acrylate, butyl di(meth) acrylate, Hexyl (meth) acrylate and the like. These may be used alone or in combination.

1.6. Other ingredients

The optical adhesive composition of the present embodiment may further contain components other than the component (A), the component (B), the component (C), the component (D), and the component (E), as needed. For example, the adhesive composition of the present embodiment can be blended with a (F) decane coupling agent (hereinafter, also referred to as "(F) component"), (G) ion, within a range that does not impair the effects of the present invention. Compound (hereinafter also referred to as "(G) component)", (H) solvent (hereinafter also referred to as "(H) component)", antioxidant, ultraviolet absorber, tackifier , plasticizers, etc.

1.6.1. (F) decane coupling agent

In the optical adhesive composition of the present embodiment, the adhesive layer formed of the optical adhesive composition of the present embodiment and the adherend can be kept good by containing the component (F). The component (F) may be a fluorene compound containing a polymerizable unsaturated group such as vinyl trimethoxy decane, vinyl triethoxy decane or (meth) propylene methoxy propyl trimethoxy decane; oxygen Propyloxypropyltrimethoxydecane, 3-glycidoxypropylmethyldimethoxydecane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxydecane have epoxy Structure of hydrazine compound; 3-aminopropyltrimethoxydecane, N-(2-aminoethyl)-3-aminopropyltrimethoxydecane and N-(2-aminoethyl)-3 - an amine group-containing oxime compound such as aminopropylmethyldimethoxydecane; and 3-chloropropyltrimethoxydecane; an oligomer type decane coupling agent, etc., wherein the component (A) has The decane coupling agent containing the functional group and the epoxy group-reactive functional group contained in the component (B) is preferred from the viewpoint that peeling is less likely to occur in a hot and humid environment.

The content of the component (F) in the optical adhesive composition of the present embodiment may be 0.01 parts by mass or more based on 100 parts by mass of the component (A). 1 part by mass or less is preferably 0.05 part by mass or more and 1 part by mass or less.

1.6.2. (G) ionic compounds

Further, the adhesive composition of the present embodiment may contain an ionic compound (G). The adhesive composition of the present embodiment can effectively prevent the adhering body from being charged by containing the (G) component. The component (G) is, for example, an ionic compound containing an anion and a cation and being liquid or solid at 25 ° C, and specific examples thereof include an alkali metal salt, an ionic liquid (liquid at 25 ° C), and interfacial activity. Agents, etc.

The alkali metal salt may, for example, be a compound containing an alkali metal cation such as lithium, sodium or potassium and an anion, and specific examples thereof include sodium chloride, potassium chloride, lithium chloride, lithium perchlorate, potassium chlorate, and potassium nitrate. , sodium nitrate, sodium carbonate, sodium thiocyanate, LiBr, LiI, LiBF ₄ , LiPF ₆ , LiSCN, sodium acetate, sodium alginate, sodium lignosulfonate, sodium toluenesulfonate, LiCF ₃ SO ₃ , Li (CF ₃ SO ₂ ) ₂ N, Li(CF ₃ SO ₂ )IN, Li(C ₂ F ₅ SO ₂ ) ₂ N, Li(C ₂ F ₅ SO ₂ )IN, Li(CF ₃ SO ₂ ) ₃ C, or the like.

Examples of the cation constituting the ionic liquid include a piperidinium cation, a pyrrolidinium cation, a cation having a pyrroline skeleton, a cation having a pyrrole skeleton, an imidazolium cation, a tetrahydropyrimidinium cation, and dihydropyrimidinium. Examples of the anion of the ionic liquid, such as a cation, a pyrazolium cation, a pyrazolinium cation, a tetraalkylammonium cation, a trialkylphosphonium cation, a tetraalkylphosphonium cation, etc., may be exemplified by Cl ^- and Br ^- , I ^- , AlCl ₄ ^- , Al ₂ Cl ₇ ^- , BF ₄ ^- , PF ₆ ^- , ClO ₄ ^- , NO ₃ ^- , CH ₃ COO ^- , CF ₃ COO ^- , CH ₃ SO ₃ ^- , CF ₃ SO ₃ ^- , (CF ₃ SO ₂ ) ₂ N ^- , (CF ₃ SO ₂ ) ₃ C ^- , AsF ₆ ^- , SbF ₆ ^- , NbF ₆ ^- , TaF ₆ ^- , F(HF) _n ^- (n = 2 to 3 ), (CN) ₂ N ^- , C ₄ F ₉ SO ₃ ^- , (C ₂ F ₅ SO ₂ ) ₂ N ^- , C ₃ F ₇ COO ^- , (CF ₃ SO ₂ )(CF ₃ CO)N ^- .

Then, the ionic compound may be an ionic compound which is composed of the cations and anions and which is liquid at 25 ° C. Specific examples of such an ionic compound include 2-methyl-1-pyrroline tetrafluoroborate, 1-ethyl-2-phenylindole tetrafluoroborate, and 1,2-dimethylhydrazine. Fluoroborate, 1-ethyloxazole tetrafluoroborate, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium acetate, 1-ethyl- 3-methylimidazolium trifluoroacetate, 1-ethyl-3-methylimidazolium heptafluorobutyrate, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-ethyl 3-methylimidazolium perfluorobutane sulfonate, 1-ethyl-3-methylimidazolium dicyandiamide, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl) Imine, 1-ethyl-3-methylimidazolium bis(pentafluoroethanesulfonyl)imide, 1-ethyl-3- Methylimidazolium (trifluoromethanesulfonyl) methide, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium hexafluorophosphate, 1 -butyl-3-methylimidazolium trifluoroacetate, 1-butyl-3-methylimidazolium heptafluorobutyrate, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazolium perfluorobutane sulfonate, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-hexyl-3-methyl Imidazolium bromide, 1-hexyl-3-methylimidazolium chloride, 1-hexyl-3-methylimidazolium tetrafluoroborate, 1-hexyl-3-methylimidazolium hexafluorophosphate, 1- Hexyl-3-methylimidazolium trifluoromethanesulfonate, 1-octyl-3-methylimidazolium tetrafluoroborate, 1-octyl-3-methylimidazolium hexafluorophosphate, 1-hexyl -2,3-dimethylimidazolium tetrafluoroborate, 1,2-dimethyl-3-propylimidazolium bis(trifluoromethanesulfonyl)imide, 1-methylpyrazolinium tetramine Fluoroborate, 3-methylpyrazolium tetrafluoroborate, tetrahexylammonium bis(trifluoromethanesulfonyl)imide, diallyldimethylammonium tetrafluoroborate, diallyl Dimethylammonium trifluoromethanesulfonate, diallyldimethylammonium bis(trifluoromethanesulfonyl)imide, diallyldimethylammonium bis(pentafluoroethanesulfonyl) Amine, N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium tetrafluoroborate, N,N-diethyl-N-methyl-N-(2- Methoxyethyl)ammonium trifluoromethanesulfonate, N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium bis(trifluoromethanesulfonyl)imide , N,N-Diethyl-N-methyl-N-(2-methoxyethyl)ammonium bis(pentafluoroethanesulfonyl)imide, epoxypropyltrimethylammonium trifluoromethane Sulfonic acid salt, epoxypropyltrimethylammonium bis(trifluoromethanesulfonyl)imide, epoxypropyltrimethylammonium bis(pentafluoroethanesulfonyl)imide, 1-butylpyridine Lanthanum (trifluoromethanesulfonyl) trifluoroacetamide, 1-butyl-3-methylpyridinium (trifluoromethanesulfonyl) Fluoroacetamide, 1-ethyl-3-methylimidazolium (trifluoromethanesulfonyl) trifluoroacetamide, N,N-diethyl-N-methyl-N-(2-methoxy Ethyl ethyl) ammonium (trifluoromethanesulfonyl) trifluoroacetamide, diallyldimethylammonium (trifluoromethanesulfonyl) trifluoroacetamide, epoxypropyltrimethylammonium ( Trifluoromethanesulfonyl)trifluoroacetamide, N,N-dimethyl-N-ethyl-N-propylammonium bis(trifluoromethanesulfonyl)imide, N,N-dimethyl -N-ethyl-N-butylammonium bis(trifluoromethanesulfonyl)imide, N,N-dimethyl-N-ethyl-N-amylammonium bis(trifluoromethanesulfonyl) Imine, N,N-dimethyl-N-ethyl-N-hexyl ammonium bis(trifluoromethanesulfonyl)imide, N,N-dimethyl-N-ethyl-N-heptyl ammonium Bis(trifluoromethanesulfonyl)imide, N,N-dimethyl-N-ethyl-N-methylammonium bis(trifluoromethanesulfonyl)imide, N,N-dimethyl- N,N-dipropylammonium bis(trifluoromethanesulfonyl)imide, N,N-dimethyl-N-propyl-N-butylammonium bis(trifluoromethanesulfonyl)imide, N,N-Dimethyl-N-propyl-N-pentyl ammonium bis(trifluoromethanesulfonyl)imide, N,N-dimethyl-N-propyl-N-hexylammonium double (three Fluoromethanesulfonyl)imide, N,N-dimethyl- N-propyl-N-heptyl ammonium bis(trifluoromethanesulfonyl)imide, N,N-dimethyl-N-butyl-N-hexylammonium bis(trifluoromethanesulfonyl)imide , N,N-dimethyl-N-butyl-N-heptyl ammonium bis(trifluoromethanesulfonyl)imide, N,N-dimethyl-N-pentyl-N-hexylammonium bis ( Trifluoromethanesulfonyl)imide, N,N-dimethyl-N,N-dihexylammonium bis(trifluoromethanesulfonyl)imide, trimethylheptylammonium bis(trifluoromethanesulfonate) Imine, N,N-diethyl-N-methyl-N-propylammonium bis(trifluoromethanesulfonyl)imide, N,N-diethyl-N-methyl-N- Amyl ammonium bis(trifluoromethanesulfonyl)imide, N,N-diethyl-N-methyl-N-heptyl ammonium bis(trifluoromethanesulfonyl)imide, N,N-di Ethyl-N-propyl-N-pentyl ammonium bis(trifluoromethanesulfonyl)imide, triethylpropylammonium bis(trifluoro Methanesulfonyl)imide, triethylammonium bis(trifluoromethanesulfonyl)imide, triethylheptylammonium bis(trifluoromethanesulfonyl)imide, N,N-dipropyl --N-methyl-N-ethylammonium bis(trifluoromethanesulfonyl)imide, N,N-dipropyl-N-methyl-N-amylammonium bis(trifluoromethanesulfonyl) Imine, N,N-dipropyl-N-butyl-N-hexylammonium bis(trifluoromethanesulfonyl)imide, N,N-dipropyl-N,N-dihexylammonium bis ( Trifluoromethanesulfonyl)imide, N,N-dibutyl-N-methyl-N-amylammonium bis(trifluoromethanesulfonyl)imide, N,N-dibutyl-N- Methyl-N-hexyl ammonium bis(trifluoromethanesulfonyl)imide, trioctylmethylammonium bis(trifluoromethanesulfonyl)imide, N-methyl-N-ethyl-N-propyl Base-N-amyl ammonium bis(trifluoromethanesulfonyl)imide and the like.

As the surfactant, any of a nonionic surfactant, a cationic surfactant, an anionic surfactant, and an amphoteric surfactant can be used.

Examples of the nonionic surfactant include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether and polyoxyethylene stearyl ether; polyoxyethylene octylphenyl ether and polyoxyethylene fluorenyl group; Polyoxyethylene alkylphenyl ethers such as phenyl ether; sorbitan higher fatty acid esters such as sorbitan monolaurate, sorbitan monostearate, sorbitan trioleate Polyoxyethylene sorbitan monolaurate and other polyoxyethylene sorbitan higher fatty acid esters; polyoxyethylene monolaurate, polyoxyethylene monostearate and other polyoxyethylene higher fatty acid esters; For example, higher fatty acid glycerides such as oleic acid monoglyceride and stearic acid monoglyceride; polyoxyalkylenes such as polyoxyethylene, polyoxypropylene, and polyoxybutylene; and these block copolymers.

As the above cationic surfactant, chlorine is exemplified. An alkyltrimethylammonium chloride, a dialkyldimethylammonium chloride, a benzalkonium chloride salt, an alkyldimethylammonium ethylsulfate or the like.

Examples of the anionic surfactant include sodium laurate, sodium oleate, sodium N-nonyl-N-methylglycine, and sodium carboxylate lauryl ether carboxylate. Sodium sulfonate, dialkyl sulfosuccinate salt, sulfonate such as sodium dimethyl-5-sulfonate isophthalate, sodium lauryl sulfate, sodium polyoxyethylene lauryl ether sulfate And a sulfate salt such as polyoxyethylene nonylphenyl ether sulfate, a phosphate salt such as polyoxyethylene sodium lauryl phosphate or polyoxyethylene nonylphenyl ether phosphate.

Examples of the amphoteric surfactant include a carboxybetaine type surfactant, an aminocarboxylate, an imidazolium betaine, a lecithin, an alkylamine oxide, and the like. Further, other conductive polymers, conductive carbon, ammonium chloride, aluminum chloride, copper chloride, iron chloride, ammonium sulfate, or the like can be used.

1.6.3. (H) component

The solvent of the (H) component is exemplified by an organic solvent. The organic solvents may be used alone of the above-described "1.1.8. (A ₁₎ component of the polymerization process" column exemplified by, or a mixture of two or more.

1.7. Gel fraction

In the optical adhesive composition of the present embodiment, the gel fraction is preferably 20% or more and 95% or less, more preferably 50, from the viewpoint of the adhesive sheet which is excellent in adhesion and durability. More than % and less than 95%.

In the optical adhesive composition of this embodiment, the gel fraction can be used, for example, by using a monomer used in preparing the adhesive composition. The type or amount of the component (a2) in the mixture and the type or amount of the component (C) are adjusted. Further, the above gel fraction can be obtained by adding a dry weight of 0.1 g (dry weight (1)) of the crosslinked adhesive to the sample vial, further adding 30 cc of ethyl acetate to the vial, shaking for 24 hours, The contents of the sample vial were filtered by a stainless steel metal gauze of 200 mesh, and the residue on the metal mesh was dried at 100 ° C for 2 hours, and the dry weight (dry weight (2)) was measured, from the following formula (2). Seek.

Gel fraction (%) = (dry weight (2) / dry weight (1)) × 100... (2)

1.8. Method of manufacturing an adhesive sheet using the first adhesive composition

(first manufacturing method)

The first production method according to an embodiment of the present invention is a method for producing an adhesive sheet using the first adhesive composition, which is obtained by applying a first adhesive composition to a surface of a separator and drying it. More specifically, the first production method includes the steps of: applying a first adhesive composition to a surface of a separator to obtain a coating liquid layer; and removing a solvent from the coating liquid layer and aging it to obtain The step of using an adhesive sheet for optics. That is, the first manufacturing method differs from the second manufacturing method in that an adhesive sheet is produced using an adhesive composition containing a (H) solvent. In other words, the first adhesive composition contains, for example, 100 parts by mass of the component (A ₁ ), 0.3 parts by mass or more and 20 parts by mass or less of the component (B), and 0.1 parts by mass or more and 5 parts by mass or less of the component (C) and ( H) The solvent is 50 parts by mass or more and 300 parts by mass or less. In this case, when the (A ₁ ) component of the first adhesive composition contains a hydroxyl group, in addition to the reaction of the epoxy propyl groups in the component (B), the hydroxyl group in the (A ₁ ) component can be used ( The reaction of the isocyanate group in the component C) forms a crosslinked structure, so that an adhesive layer having more excellent durability can be obtained.

1.9. Method of manufacturing adhesive sheet using the second adhesive composition

(Second manufacturing method)

In the second manufacturing method of one embodiment of the present invention, a method of producing an adhesive sheet using the second adhesive composition is used. The second production method differs from the first production method in that an adhesive sheet is produced using an adhesive composition that does not substantially contain a solvent. In other words, the second adhesive composition contains, for example, 100 parts by mass of the component (A ₂ ) and 0.3 parts by mass or more and 20 parts by mass or less of the component (B), and substantially no (H) solvent. The second adhesive composition contains substantially 100 parts by mass of the component (A ₂ ) and 0.3 parts by mass or more and 20 parts by mass or less of the component (B), and substantially no (H) solvent, and substantially no solvent is present. The adhesive layer is formed in the state. In this case, when the (A ₂ ) component of the second adhesive composition contains a hydroxyl group, in addition to the reaction of the epoxy propyl groups in the component (B), it may be formed by the addition of the component (C) (A _{2 )} The crosslinked structure of the hydroxyl group in the component and the isocyanate group in the component (C) provides an adhesive layer which is more excellent in durability.

More specifically, the second manufacturing method includes the steps of: applying a coating liquid to the surface of the separator to obtain a coating liquid layer; and irradiating the coating liquid layer with light (for example, ultraviolet ray) to obtain optical a step of using an adhesive sheet, wherein the coating liquid contains: (a1) 60% by mass or more and 85% by mass or less of the (meth)acrylic acid alkyl ester monomer, and (a2) a hydroxyl group-containing monomer of 15% by mass or more and 100 parts by mass of the partial copolymer (A ₂ ) of the monomer mixture of 40% by mass or less (here, the above (a1) alkyl (meth) acrylate monomer with respect to 100% by mass of the above (A) acrylic polymer And (a2) the total amount of the hydroxyl group-containing monomer is 75 mass% or more and 100 mass% or less), (B) component 0.3 mass part or more, 20 mass parts or less, and (D) component.

The coating liquid may be prepared by adding the component (D) to the second adhesive composition. Further, the coating liquid may be one which does not substantially contain a solvent. Here, the content of the solvent contained in the coating liquid is 1% by mass or less, and specifically means that the solvent is not blended in the coating liquid. According to the second production method, the coating liquid is produced by using the coating liquid containing the composition, if the coating liquid contains the component (A ₂ ), the component (B), and the component (D) and does not substantially contain a solvent. In the case of the adhesive sheet, the film thickness is hardly changed before and after the step of irradiating the coating liquid layer formed using the coating liquid, so that not only the film thickness of the obtained adhesive sheet can be predicted in advance, but also the step of removing the solvent can be omitted. Therefore, the simplification of the manufacturing steps can be achieved.

Further, in the second production method, the coating liquid may further contain the component (E) and the component (C) or any of them. In other words, in this case, the component (E) and the component (C) or any of them are added to the second adhesive composition.

In addition, the coating liquid layer obtained by applying the coating liquid to the surface of the separator is irradiated with light such as ultraviolet rays to polymerize the polymerizable component in the coating liquid layer. That is, the monomer contained in the component (A ₂ ) (when the component (E) and the component (C) are contained, or the component (E) and the component (C) or any of them )reaction. In this case, the irradiation time of light such as ultraviolet rays is usually 1 second or longer and 300 seconds or shorter, preferably 1 second or longer and 180 seconds or shorter.

The monomer in the (A ₂ ) component is polymerized by irradiating light, and the epoxy propyl groups in the component (B) are reacted with each other (again, when the (A ₂ ) component contains a hydroxyl group and further contains (C) In the case of a component, the hydroxyl group reacts with the isocyanate group in the component (C), and when the component (E) is contained, the crosslinked structure is formed by the reaction of the monomer in the component (A ₂ ) with the component (E). An adhesive layer excellent in durability can be obtained. Further, since the second adhesive composition does not substantially contain a solvent, when the adhesive sheet is produced using the composition, the film thickness hardly changes before and after the step of irradiating the coating liquid layer formed using the composition. Therefore, the film thickness of the obtained adhesive sheet can be predicted in advance.

1.10. Use

The optical adhesive composition of the present embodiment can be used for bonding a member constituting the touch panel type input/output device, and the member to be bonded to the optical adhesive composition of the present embodiment can be optical. a member (for example, an optical film selected from the group consisting of a polarizing film, a retardation film, an elliptically polarizing film, an antireflection film, a brightness enhancement film, a light diffusion film, and a hard coating film), a metal layer such as an ITO layer, or a glass containing Or a plastic substrate. More specifically, the optical adhesive composition of the present embodiment can be suitably used for bonding of members constituting the touch panel type input/output device.

An example in which the optical adhesive composition of the present embodiment is used for bonding a member constituting the touch panel type input/output device will be described with reference to Fig. 1 . Fig. 1 is a cross-sectional view schematically showing the configuration of an input/output device (touch panel type input/output device 100) according to an embodiment of the present invention. The touch panel type input/output device 100 of the present embodiment includes a liquid crystal display device (LCD) 10, a touch panel portion 20, and an adhesive layer 30 disposed between the LCD 10 and the touch panel portion 20. The adhesive layer 30 causes the LCD 10 to be followed by the touch panel portion 20.

In the adhesive layer 30, for example, according to the first manufacturing method of the present embodiment, the first optical adhesive composition of the present embodiment is applied onto the surface of a separator (not shown), and the obtained adhesive sheet is dried. The separator is peeled off and disposed between the LCD 10 and the touch panel portion 20.

Alternatively, the adhesive layer 30 may be added with the component (D) in the second optical adhesive composition of the present embodiment, for example, according to the second manufacturing method of the present embodiment. The coating liquid of the component (C) or any of them is applied to the surface of a separator (not shown) to form a coating liquid layer, and the coating liquid layer is irradiated with light (for example, ultraviolet rays) to form an adhesive sheet. Then, the adhesive sheet is peeled off from the separator and disposed between the LCD 10 and the touch panel portion 20.

Further, as shown in Fig. 1, the LCD 10 is composed of a polarizing plate 11, an adhesive layer 12, a liquid crystal panel 13, an adhesive layer 14, and a polarizing plate 15 in this order. The adhesive layer 12 is followed by the polarizing plate 11 and the liquid crystal panel 13, and the adhesive layer 14 is followed by the liquid crystal panel 13 and the polarizing plate 15.

Further, as shown in FIG. 1, the touch panel portion 20 is formed by sequentially stacking a shatterproof film 16, an adhesive layer 17, an ITO layer 18, and a glass panel 19. The adhesive layer 17 is followed by the shatterproof film 16 and the ITO layer 18.

The adhesive layers 12, 14, and 17 are the same as the adhesive layer 30, and the optical adhesive composition of the present embodiment is produced by the first manufacturing method or the second manufacturing method.

1.11. Effect

The optical adhesive composition of the present embodiment contains the component (A) When 100 parts by mass and (B) component are used in an amount of 0.3 parts by mass or more and 20 parts by mass or less, and the adhesive sheet is produced by using the optical adhesive composition, the epoxy propyl groups in the component (B) react with each other (again, when When the component (A) contains a hydroxyl group, the hydroxyl group reacts with the isocyanate group in the component (C) by the addition of the component (C) to form a crosslinked structure, so that the adhesive layer is less likely to float under high humidity conditions or Exfoliation, excellent durability. In particular, the optical adhesive composition of the present embodiment is suitable for use as a member of a touch panel type input/output device comprising a metal such as ITO because the component (A) does not substantially contain a carboxyl group and does not have a property of corroding a metal. fit.

2. Adhesive sheet

The adhesive sheet (optical adhesive sheet) of the present embodiment is obtained by using, for example, the first adhesive composition or the second adhesive composition according to the first production method or the second production method. The thickness of the adhesive sheet is usually 10 μm or more and 500 μm or less, preferably 20 μm or more and 300 μm or less.

More specifically, the first adhesive composition may be applied onto a substrate by a gravure coater, a Meyer bar coater, an air knife coater, a roll coater or the like. The adhesive sheet of this embodiment is produced by drying at room temperature or by heating as needed.

Alternatively, the coating liquid containing the second adhesive composition may be applied by a gravure coater, a wire bar coater, an air knife coater, a roll coater or the like, and the coating liquid may be applied. The layer is irradiated with light to form an adhesive sheet of this embodiment.

According to the adhesive sheet of the present embodiment, the adhesive composition (the first adhesive composition or the second adhesive group) of the above embodiment is used. The formation of the product is excellent in adhesion and durability, so that the floating or peeling generated under high humidity conditions is reduced, and the metal is not corroded. Therefore, the adhesive sheet of the present embodiment can be suitably used for bonding of optical members, and more specifically, can be suitably used for bonding of members constituting the touch panel type input and output device.

3. Image display device and input and output device

An image display device according to another embodiment of the present invention includes the optical adhesive sheet of the above embodiment. The image display device of this embodiment may, for example, be a liquid crystal display device. Further, the input/output device according to another embodiment of the present invention includes the optical adhesive sheet of the above-described embodiment. In this case, the input/output device may be, for example, a touch panel type input/output device of a capacitance type.

4. Examples

Hereinafter, the present invention will be described based on the following examples, but the present invention is not limited to the examples.

4.1. Example 1 (Production of adhesive sheet of the first method for producing the adhesive composition by containing (A ₁₎ of the component)

4.1.1. Preparation Example 1 (Modulation of Acrylic Polymer)

In a reaction apparatus equipped with a stirrer, a reflux condenser, a thermometer, and a nitrogen gas introduction tube, a monomer mixture having a mixing ratio shown in Table 2 below was fed, and then the concentration of the monomer mixture was adjusted to 30% by mass. Feed equal amounts of ethyl acetate and toluene. Then, 0.1 part by mass of azobisisobutyronitrile was added, and the air in the reaction vessel was stirred while substituting the air in the reaction vessel, and the mixture was heated to 70 ° C, and then reacted for 6 hours. After the reaction, the acetic acid The ester was diluted to obtain acrylic polymers 1 to 5.

4.1.2. Manufacturing Example 1 (Production of Adhesive Sheet)

Using the acrylic polymers 1 to 5 obtained in the above 4.1.1, the components were added in the following Table 3 (solid formulation) to obtain solutions of the adhesive compositions of Examples 1 to 10 and Comparative Examples 1 to 4. . A solution of the adhesive composition was applied onto the surface of the release-treated polyester film and dried to obtain an adhesive sheet having an adhesive layer thickness of 50 μm. An adhesive sheet for evaluation was obtained by laminating a polyethylene terephthalate film having a thickness of 100 μm on the side of the adhesive layer of the obtained adhesive sheet.

4.2. Example 2 (Manufacture of Adhesive Sheet by Second Manufacturing Method Using Adhesive Composition Containing (A ₂ ) Component)

4.2.1. Preparation Example 2 (Modulation of Acrylic Polymer)

With a blender, reflux cooler, thermometer and nitrogen inlet tube In the reaction apparatus, a monomer mixture having a blending ratio shown in Table 4 below and (for the polymer 6, 7, 9 0.05 parts by mass, for the polymer 8 series 1 part by mass) of the chain transfer agent were fed into the positive ten The dialkyl mercaptan was stirred while replacing the air with nitrogen, and the temperature was raised to 50 °C. Then, 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) is added in an appropriate amount so that the reaction liquid is heated to 120 ° C or more and 140 ° C or less, and polymerization is carried out. Acrylic polymer 6 to 9 (partial polymer of 25% or more and 60% or less of the polymer part). In addition, the polymer part of the acrylic polymer is a ratio (% by mass) of the solid content remaining when the acrylic polymer (partial polymer) is heated at 150 ° C for 1 hour. Further, the "Tg" of each polymer shown in Table 4 represents the Tg value assuming that all of the monomer mixtures used are polymerized.

4.2.2. Manufacturing Example 2 (Production of Adhesive Sheet)

Using the acrylic polymers 6 to 9 obtained in the above 4.2.1., the components were added in the following formulation (solid content formulation) to obtain the adhesive compositions of Examples 11 to 19 and Comparative Examples 5 to 8. Coating solution. After applying the coating liquid to the surface of the release-treated polyester film, the release-treated polyester film was covered to sandwich the coating liquid layer, and the strength was 30 mW/cm ² from the upper and lower sides of the coating liquid layer. Black light was irradiated for 180 seconds, whereby an adhesive sheet having an adhesive layer thickness of 150 μm was obtained. The polyester film on one side of the obtained adhesive sheet was peeled off, and a polyethylene terephthalate film having a thickness of 100 μm was attached to obtain an evaluation adhesive sheet.

For each of the adhesive sheets, the heat resistance and the metal corrosion resistance shown in Tables 3 and 5 above were evaluated by the following methods. Further, the gel fraction of each of the adhesive compositions was measured. Further, regarding the adhesive sheet of Example 2, the haze change after the damp heat test was evaluated. Further, it is confirmed that the acrylic polymers 1 to 4 and 6 to 8 have a hydroxyl group by the appearance of adsorption of 3400 to 3200 cm ^-1 in, for example, the IR spectra of the respective acrylic polymers 1 to 4 and 6 to 8.

4.3. Evaluation method

4.3.1. Gel fraction

The gel fraction of each of the adhesive compositions was measured by the method described in the column of the above embodiment.

4.3.2. Damp heat cycle test (durability)

The evaluation adhesive sheet prepared in the above 4.2.2. was cut (50 mm × 60 mm), and the peeled polyester film was peeled off, so that the adhesive layer was attached to the polycarbonate sheet by using a laminated roller. One side of a polycarbonate plate with a thickness of 2.0 mm. After the attachment, the autoclave (manufactured by Kurihara Seisakusho Co., Ltd.) was pressure-treated at 0.5 MPa, 50 ° C, and 20 minutes to obtain a test plate. The test plate thus obtained was placed at 60 ° C / 95% RH for 24 hours and placed in a dry environment at 85 ° C for 24 hours. The cycle test was carried out 100 times. After the end of the test, the test plate was taken out from the test environment, and after standing at 23 ° C / 50% RH for 1 hour, the wet heat cycle test (durability) of the adhesive layer was evaluated visually according to the following evaluation criteria.

(assessment)

○: no floating, peeling, foaming, etc.

×: There are float, peeling, foaming, etc.

4.3.3. Metal corrosivity

The adhesive sheet obtained by the use of the compositions of Examples 1 to 14 and Comparative Examples 1 to 5 obtained in Production Example 1 was cut into 10 mm × 60 mm and attached to an ITO vapor-deposited PET film cut to 10 mm × 100 mm at 50 ° C × 5 atm was subjected to autoclave treatment for 20 minutes. Then, after standing at room temperature for 1 hour, it was allowed to stand in an environment of 60 ° C and 90% RH for 500 hours, and after standing at 23 ° C and a humidity of 65% RH for 1 hour, the resistance value of the ITO vapor-deposited film was measured, and The resistance value before the test was compared, and the rate of change of the resistance value with respect to the resistance value before the test was obtained.

When the resistance value change rate of the resistance value before the test was 115% or more, it was judged that ITO corrosion property (×), and when the resistance value change rate with respect to the resistance value before the test was less than 115%, it was judged that there was no ITO. Corrosive (○). Further, the resistance value was measured by using a testing machine (manufactured by Sanhe Electric Meter Co., Ltd., Digital Multimeter PC510).

4.3.4. Haze after damp heat test

The adhesive sheet for evaluation prepared in the above 4.2.2. was peeled off, and the release-treated polyester film was peeled off so that the adhesive layer was in contact with the glass substrate, and a measurement sample was prepared by using a haze meter (model number) The "HM-150", manufactured by Murakami Color Technology Research Co., Ltd.) measures the haze (initial haze). Then, the sample was placed under a condition of 60 ° C to 95% RH for 500 hours, and then moved to 23 ° C to 50% RH for 10 minutes, and then the haze (haze after the damp heat test) was measured. The haze (haze change value) after the initial haze-damp heat test is preferably 0.5 or less.

Further, the abbreviations in Tables 2 to 5 are as follows.

AA: Acrylic

AM: acrylamide

BA: n-butyl acrylate

t-BA: tert-butyl acrylate

DMAEA: dimethylaminoethyl acrylate

2-EHA: 2-ethylhexyl acrylate

2-HEA: 2-hydroxyethyl acrylate

MA: Methyl acrylate

TMPTA: Trimethylolpropane triacrylate

TETRAD C: 1,3-bis(N,N-diepoxypropylaminomethyl)cyclohexane (molecular weight 385, the number of epoxy propyl groups contained in 1 molecule is 4, Mitsubishi Gas Chemical Co., Ltd. Company system)

TETRAD X: N, N, N', N'-tetraepoxypropyl-m-xylenediamine (molecular weight 380, the number of epoxy propyl groups contained in 1 molecule is 4, manufactured by Mitsubishi Gas Chemical Co., Ltd. )

DENACOL EX212L: 1,6-hexanediol epoxy propyl ether (molecular weight 260, 2 molecules of epoxy propyl group contained in 2 molecules, manufactured by Nagase ChemteX Co., Ltd.)

jER1004: (Molecular weight 1,650, the number of epoxy propyl groups contained in 1 molecule is 2, manufactured by Mitsubishi Chemical Corporation)

CORONATE L: Trimethylolpropane adduct of toluene diisocyanate (made by Japan Polyurethane Industry Co., Ltd.)

DURANATE 24A-100: Biuret type isocyanate compound (made by Asahi Kasei Co., Ltd.)

DAROCUR 1173: 2-hydroxy-2-methyl-1-phenyl-propan-1-one (BASF Japan Co., Ltd.)

As a result of the results of Table 3, the composition of the above Examples 1 to 10 contains 100 parts by mass of the component (A) and 0.3 parts by mass or more and 20 parts by mass or less of the component (B), and the epoxy resin contained in the component (B) The propyl group reacts intramolecularly and/or intermolecularly, and the hydroxyl group contained in the component (A) reacts with the isocyanate group contained in the component (C) to form a crosslinked structure, so that the adhesive layer formed using the composition is It is not easy to cause floating or peeling under high humidity conditions, and high adhesion and excellent durability can be achieved. Further, since the component (A) does not substantially have a carboxyl group, it does not have the property of corroding a metal.

In the composition of the above-mentioned Comparative Examples 1 and 2, the ratio of the component (B) is not in the range of 0.3 part by mass or more and 20 parts by mass or less based on 100 parts by mass of the component (A), and the composition is used. The formed adhesive layer is drastically changed under high temperature and high humidity conditions to a high temperature and low humidity condition, which may cause floating or peeling, and the durability is poor.

Further, in the composition of the above Comparative Example 3, it is inferred that the epoxy group having a molecular weight of more than 1,000 in the (B) component is small because the compound having two or more epoxy propyl groups in one molecule has a molecular weight of more than 1,000, and the epoxy is caused. It is difficult for the propyl groups to crosslink each other, and as a result, the durability is poor.

Further, in the composition of Comparative Example 4, it is inferred that the substitution of the (A) component by the acrylic polymer having a carboxyl group but having no carboxyl group is more intrinsic and/or intermolecular reaction than the component (B). The reaction between the epoxypropyl group in the component (B) and the carboxyl group in the component (A) is preferentially carried out, and the reaction is excessively reacted, the crosslinking is excessively dense and the durability is poor, and the metal is corrosive due to the presence of the carboxyl group.

As a result of the results of Table 5, the composition of the above Examples 11 to 19 contains 100 parts by mass of the component (A) (component (A ₂ )) and 0.3 parts by mass or more and 20 parts by mass or less of the component (B). The epoxy propyl group contained in the component is reacted intramolecularly and/or intermolecularly, and the monomer in the (A ₂ ) component is reacted with the component (E) to form a crosslinked structure by containing the component (E), so that it is used. The adhesive layer formed of the composition is less likely to float or peel under high humidity conditions, and high adhesion and excellent durability can be achieved.

Further, since the component (A) does not substantially have a carboxyl group, it does not have the property of corroding a metal. Further, since the compositions of the above-described Embodiments 11 to 19 are substantially free of a solvent, when the adhesive sheet is produced using the coating liquid containing the composition, the coating liquid layer formed using the coating liquid is irradiated with light. There is almost no change in film thickness before and after the step, so the film thickness of the obtained adhesive sheet can be predicted in advance.

In the composition of the above-mentioned Comparative Examples 5 and 6, the ratio of the component (B) is not in the range of 1 part by mass or more and 20 parts by mass or less based on 100 parts by mass of the component (A). The adhesive layer formed by the object may float or peel under high humidity conditions, and the durability is poor.

Further, in the composition of Comparative Example 7, it is inferred that since a compound having two or more epoxy propyl groups in one molecule but having a molecular weight of more than 1,000 is used, the density of the epoxy propyl group in the component (B) is small, resulting in an epoxy. It is difficult for the propyl groups to crosslink each other, and as a result, the durability is poor.

Further, in the composition of Comparative Example 8, it is inferred that the substitution of the (A) component by the acrylic polymer having a carboxyl group but having no carboxyl group is more intrinsic and/or intermolecular reaction than the component (B). Prefer the reaction between the epoxypropyl group in the component (B) and the carboxyl group in the component (A) The degree of reaction makes the crosslinking excessively dense and the durability is poor, and the metal is corrosive due to the presence of the carboxyl group.

10‧‧‧Liquid Crystal Display Unit (LCD)

11, 15‧‧‧ polarizing plate

12, 14, 17‧‧ ‧ adhesive layer

13‧‧‧LCD panel

16‧‧‧Smashproof film

18‧‧‧ITO layer

19‧‧‧ glass panel

20‧‧‧Touch Panel Department

30‧‧‧Adhesive layer

100‧‧‧Touch panel type input and output device

Claims (13)

An optical adhesive composition comprising: (A) 100 parts by mass of an acrylic polymer substantially free of a carboxyl group; and (B) a compound having a molecular weight of 1,000 or less having two or more epoxy propyl groups in one molecule. More than or equal to 20 parts by mass. The optical adhesive composition according to the first aspect of the invention, wherein the (A) acrylic polymer contains a copolymer (A ₁ ) of a monomer mixture of the following (a1) and (a2): (a1) 60% by mass or more and 85% by mass or less of the (meth)acrylic acid alkyl ester monomer; (a2) 15% by mass or more and 40% by mass or less of the hydroxyl group-containing monomer (herein, the monomer mixture is set to When the amount is 100% by mass, the total amount of the (a1) alkyl (meth)acrylate monomer and the (a2) hydroxyl group-containing monomer is 75 mass% or more and 100 mass% or less. The optical adhesive composition according to claim 1 or 2, further comprising (C) an isocyanate crosslinking agent. The optical adhesive composition according to claim 1, wherein the (A) acrylic polymer is a partial polymer comprising a monomer mixture containing the following (a1) and (a2) (A) ₂ ) The composition of the composition: (a1) 60% by mass or more and 85% by mass or less of the (meth)acrylic acid alkyl ester monomer; (a2) 15% by mass or more and 40% by mass or less of the hydroxyl group-containing monomer When the monomer mixture is 100% by mass, the total amount of the (a1) alkyl (meth)acrylate monomer and the (a2) hydroxyl group-containing monomer is 75 mass% or more and 100 mass% or less. ). The optical adhesive composition according to claim 4, wherein the composition containing the partial polymer (A ₂ ) further contains (E) a polyfunctional monomer, and the (A) acrylic polymerization. The material is obtained from the above-mentioned composition containing the above partial polymer (A ₂ ) and the above (E) polyfunctional monomer. The optical adhesive composition according to any one of claims 2 to 5, wherein the monomer mixture further contains (a3) a nitrogen atom-containing monomer in an amount of 0.1% by mass or more and 5% by mass. the following. The optical adhesive composition according to any one of claims 1 to 6, wherein the gel fraction is 20% or more and 95% or less. The optical adhesive composition according to any one of claims 1 to 7, which can be used for bonding a member constituting a touch panel type input/output device. An adhesive sheet for optical use, which is an adhesive layer obtained from the optical adhesive composition according to any one of claims 1 to 7. A method for producing an optical adhesive sheet comprising the steps of: applying an adhesive composition to a surface of a separator to obtain a coating liquid layer; and removing a solvent from the coating liquid layer and aging to obtain an optical a step of adhering a sheet, wherein the adhesive composition contains (A) 100 parts by mass of an acrylic polymer substantially free of a carboxyl group and 2 in a molecule of (B) The compound having a molecular weight of 1,000 or less of the above-mentioned glycidyl group is 0.3 parts by mass or more and 20 parts by mass or less. The method for producing an optical adhesive sheet according to claim 10, wherein the adhesive composition further contains (C) an isocyanate crosslinking agent. A method for producing an optical adhesive sheet comprising the steps of: applying a coating liquid to a surface of a separator to obtain a coating liquid layer; and irradiating the coating liquid layer with light to obtain an optical adhesive sheet. In the step, the coating liquid contains 60% by mass or more and 85% by mass or less of the (a1) alkyl (meth) acrylate monomer, and 15% by mass or more and 40% by mass of the (a2) hydroxyl group-containing monomer. 100 parts by mass of the partial polymer (A ₂ ) of the following monomer mixture (here, when the monomer mixture is 100% by mass, the (a1) alkyl (meth) acrylate monomer and the aforementioned (a2) The total amount of the hydroxyl group-containing monomers is 75 mass% or more and 100 mass% or less, and (B) the compound having two or more epoxy propylene having a molecular weight of 1,000 or less in one molecule is 0.3 parts by mass or more and 20 parts by mass or less. And (D) a photopolymerization initiator. The method for producing an optical adhesive sheet according to claim 12, wherein the coating liquid further contains (E) a polyfunctional monomer.