TW201634642A - Pressure-sensitive adhesive composition and pressure-sensitive adhesive sheet - Google Patents

Abstract

To provide an adhesive composition that has excellent dispersibility of metal oxide particles, excellent optical characteristics (including haze and total light transmittance), and excellent adhesiveness. An adhesive composition that contains a (meth)acrylic resin (A), a dispersant (B), and metal oxide particles (C), wherein the dispersant (B) is a (meth)acrylic resin that contains an ionic group and has a weight-average molecular weight of 200 to 50000.

Description

Adhesive composition and adhesive sheet

The present invention relates to an adhesive composition and an adhesive sheet, and more particularly to an adhesive composition formed by dispersing metal oxide particles by a dispersing agent, and an adhesive sheet obtained by using the adhesive composition. .

Conventionally, an optical element such as a protective film has passed through an adhesive layer and is laminated on the surface of various display devices, touch panel devices, and the like. Generally, adhesion and optical properties (haze, total light transmittance, etc.) are required for the adhesive layer.

In the case of such an adhesive layer, it is a bonding composition containing metal oxide particles, a polymer resin, and a dispersing agent, and more specifically, for example, a metal oxide particle or a polymer resin. And an adhesive composition of a dispersing agent, an adhesive composition and a sheet-like adhesive obtained by using the adhesive composition, wherein the metal oxide particles are made of titanium oxide, zirconium oxide, zinc oxide, and pentoxide It is composed of at least one of a group consisting of cerium and a titanic acid compound, and has an average particle diameter of 20 to 150 nm, and the content of the metal oxide particles accounts for 50 to 80% by mass of the adhesive composition, and further The number average molecular weight of the polymer resin is 10,000 to 50,000 (see Patent Document 1). [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2014-172960

[Problems to be Solved by the Invention] However, in order to ensure excellent adhesion of the adhesive composition, optical characteristics, particularly haze values, are required to be improved.

Accordingly, an object of the present invention is to provide an adhesive composition which is excellent in dispersibility and optical properties (haze value, total light transmittance) of metal oxide particles, and also excellent in adhesion, and use of the adhesive The adhesive sheet obtained by the composition. [Means for solving the problem]

The adhesive composition of the present invention comprises: (A) a (meth)acrylic resin, (B) a dispersing agent, and (C) a metal oxide particle, wherein the (B) dispersing agent has an ionic group It is composed of a (meth)acrylic resin having a weight average molecular weight of 200 or more and 50,000 or less.

Meanwhile, in the adhesive composition of the present invention, preferably, the ionic group is a phosphate group, and the (C) metal oxide particles are zirconia and/or titanium oxide.

Meanwhile, in the adhesive composition of the present invention, preferably, the ionic group is a tertiary amine group, and the (C) metal oxide particles are doped with antimony tin oxide.

Meanwhile, the adhesive sheet of the present invention is formed by forming the above-mentioned adhesive composition into a layer.

The adhesive composition of the present invention contains: (A) a (meth)acrylic resin, (B) a dispersing agent, (C) a metal oxide particle, and because the (B) dispersing agent has an ionic group and Since the weight average molecular weight is composed of a (meth)acrylic resin having a molecular weight of 200 or more and 50,000 or less, the (C) metal oxide particles can be appropriately dispersed, and excellent adhesiveness and optical properties can be obtained.

Meanwhile, since the adhesive sheet of the present invention is obtained by using the adhesive composition of the present invention, the metal oxide particles in the adhesive sheet are excellent in dispersibility and excellent in adhesion and optical properties.

The adhesive composition of the present invention contains (A) a (meth)acrylic resin, (B) a dispersing agent, and (C) a metal oxide particle.

(A) The (meth)acrylic resin may be a monomer component containing a (meth)acrylic acid alkyl ester (monomer) (hereinafter, the monomer component of the (A) (meth)acrylic resin raw material is called It is obtained by polymerization of the first monomer component).

Further, the mark of (meth)acrylic acid represents acrylic acid and/or methacrylic acid.

As the alkyl (meth)acrylate, for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, or isopropyl (meth)acrylate , n-butyl (meth)acrylate, isobutyl (meth)acrylate, second butyl (meth)acrylate, tert-butyl (meth)acrylate, amyl (meth)acrylate, (methyl) ) neopentyl acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, (a) 2-ethylhexyl acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, thirteen (meth) acrylate Ester, tetradecyl (meth)acrylate, 1-methyltridecyl (meth)acrylate, hexadecyl (meth)acrylate, octadecyl (meth)acrylate (stearic acid stearic acid) Ester), (meth)acrylic acid isostearate, hexadecyl (meth) acrylate, behenyl (meth) acrylate (behenyl (meth) acrylate), (meth) acrylate Tetraester, 30% (meth) acrylate, ( Yl) acrylate, and cyclohexyl acrylate carbon number of 1 to 35 of a linear, branched or cyclic alkyl group of the (meth) acrylate. These (meth)acrylic acid alkyl esters may be used alone or in combination of two or more. As the alkyl (meth)acrylate, for example, n-butyl (meth)acrylate or 2-ethylhexyl (meth)acrylate is preferred.

Meanwhile, the first monomer component may include a copolymerizable monomer (hereinafter, referred to as a first copolymerizable monomer) copolymerizable with an alkyl (meth)acrylate.

The first copolymerizable monomer is, for example, a nitrogen-containing monomer, a hydroxyl group-containing monomer, an acidic group-containing monomer, or the like.

As the monomer containing nitrogen, for example, N-vinylpyrrolidone, N-vinyl caprolactam, (meth) propylene morpholine, N, N-dimethyl (meth) propylene Amidoxime and the like. In addition, examples of the monomer containing nitrogen include, for example, a monomer containing a tertiary amino group described later, a monomer containing a quaternary ammonium group described later, and the like. These nitrogen-containing monomers may be used singly or in combination of two or more. As the monomer containing nitrogen, for example, (meth) propylene morpholine or N, N-dimethyl (meth) acrylamide is preferable.

In the case of using a monomer containing nitrogen, the content ratio is, for example, 0.5% by mass or more, preferably 1% by mass based on the total mass of the first monomer component from the viewpoint of improving the adhesion. The above is, for example, 30% by mass or less, preferably 15% by mass or less.

As the monomer having a hydroxyl group, for example, 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, Caprolactone is modified with (meth) acrylate, polyethylene glycol acrylate, and the like. These hydroxyl group-containing monomers may be used singly or in combination of two or more. As the monomer having a hydroxyl group, for example, 2-hydroxyethyl (meth) acrylate is preferable.

In the case of using a monomer having a hydroxyl group, the content ratio is, for example, 0.1% by mass or more, and for example, 5% by mass or less based on the total mass of the first monomer component from the viewpoint of improving the adhesion. It is preferably 2% by mass or less.

As the monomer having an acidic group, for example, acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, ethylene oxide modified succinic acid, acrylate or the like The monomer having a carboxyl group, and, for example, a monomer having a sulfonic acid group such as 2-propenylamine-2-methylpropanesulfonic acid. These acidic group-containing monomers may be used singly or in combination of two or more. As the monomer having an acidic group, for example, a monomer having a carboxyl group is preferred, and acrylic acid is more preferred.

In the case of using a monomer having an acidic group, the content ratio is, for example, 0.1% by mass or more, more preferably 0.5, based on the total mass of the first monomer component from the viewpoint of improving the adhesion. The mass% or more is, for example, 20% by mass or less, preferably 10% by mass or less.

Meanwhile, as the first copolymerizable monomer, for example, an alkane polyol poly(meth)acrylate.

In the case of an alkane polyol poly (meth) acrylate, for example, neopentyl glycol di(meth)acrylate, 1,6 hexanediol di(methyl) ) acrylate, propylene glycol di(meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylol methane tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, etc. (meth) acrylates of polyhydric alcohols, and the like. These alkane polyol poly(meth)acrylates may be used alone or in combination of two or more. As the alkane polyol poly(meth) acrylate, for example, 1,6 hexanediol di(meth) acrylate is preferable.

In the case of using the alkane polyol poly(meth) acrylate, the content ratio is, for example, 0.01% by mass or more based on the total mass of the first monomer component, from the viewpoint of improving the adhesion. For example, it is 2 mass% or less, preferably 1 mass% or less.

In addition, the first copolymerizable monomer is, for example, a monomer containing a saturated alicyclic group having two or more rings.

Examples of the monomer having a saturated alicyclic group having two or more rings include, for example, a (cyclo) group-containing (meth) acrylate, a tricyclic group-containing (meth) acrylate, The (meth) acrylate or the like containing a tetracyclic group is preferably, for example, a (meth) acrylate containing a bicyclo group or a (meth) acrylate containing a tricyclic group.

Examples of the (meth) acrylate containing a bicyclic group include, for example, borneol-based (meth) acrylate, isobornyl (meth) acrylate, dicyclopentyl (meth) acrylate, and the like. . These (meth) acrylates containing a bicyclic group may be used alone or in combination of two or more.

Examples of the (meth) acrylate containing a tricyclic group include, for example, adamantyl (meth) acrylate, dimethyl adamantyl (meth) acrylate, and the like. These trimethyl group-containing (meth) acrylates may be used alone or in combination of two or more.

These monomers containing a saturated alicyclic group having two or more rings may be used singly or in combination of two or more.

Further, as the first copolymerizable monomer, for example, an aromatic vinyl monomer such as styrene, vinyltoluene or α-methylstyrene, and for example, (meth)acrylonitrile or the like. a vinyl cyanide monomer, and, for example, a itaconate such as Itaconic acid benzyl, a maleate such as dimethyl maleate, or a dimethyl fumarate A horse carboxylate, acrylonitrile, methacrylonitrile, vinyl acetate or the like is exemplified by vinyl acetate.

These first copolymerizable monomers may be used singly or in combination of two or more.

The first monomer component preferably contains a first copolymerizable monomer.

In the case where the first monomer component contains the first copolymerizable monomer, the content of the alkyl (meth)acrylate is, for example, 60% by mass or more, preferably, based on the total mass of the first monomer component. 70% by mass or more, and for example, 98% by mass or less, preferably 95% by mass or less. Meanwhile, the content ratio of the first copolymerizable monomer is, for example, 2% by mass or more, preferably 5% by mass or more, and preferably 40% by mass or less, and preferably 30%, based on the total mass of the first monomer component. Below mass%.

Meanwhile, although it is described in detail later, the monomer type as the selected first monomer component is preferably repeated at least in part with the monomer species which will be described as the second monomer component to be described later.

(A) The case where the (meth)acrylic resin is present in the presence of a polymerization initiator, for example, by polymerization using a conventional polymerization method such as solution polymerization, bulk polymerization, suspension polymerization, etc. (using the first copolymerizable monomer) The situation is obtained by co-polymerization.

The polymerization initiator is not particularly limited and can be appropriately selected depending on the purpose. As the polymerization initiator, specifically, for example, a radical polymerization initiator.

Examples of the radical polymerization initiator include, for example, an azo compound, a peroxide compound, a sulfide, a sulfine, a sulfinic acid, a diazo compound, and a redox compound. Wait. For example, an azo compound or a peroxide compound is preferred.

As the azo compound, for example, azobisisobutyronitrile, azobis(dimethylvaleronitrile), azobiscyclohexanenitrile, 1,1'-azobis(1-acetonitrile) 1,1'-azobis (1-acetoxy-1-phenylethane), 2,2'-azobis(2-methylbutyronitrile) (alias: 2,2' - dimethyl azobisisobutyrate), 4,4'-azobis-4-cyanovaleric acid, and the like.

As the peroxide compound, for example, benzammonium peroxide, lauric acid peroxide, acetoxy peroxide, octyl peroxide, perylene-2,4-dichlorobenzamide, peroxidation Isobutyl hydrazine, ethoxylated cyclohexyl sulfonium oxyhydroxide, tert-butyl peroxypivalate, tert-butyl peroxy-2-ethylhexanoate, 1,1-di-tertiary butyl peroxidation Cyclohexane, 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane, 1,1-di-t-hexylperoxy-3,3,5-trimethyl Cyclohexane, isopropyl peroxydicarbonate, isobutyl peroxydicarbonate, dibutyl peroxydicarbonate, n-butyl peroxydicarbonate, 2-ethylhexyl peroxydicarbonate, Bis(4-t-butylcyclohexyl) peroxydicarbonate, third amyl peroxy-2-ethylhexanoate, 2-ethylhexanoic acid-1,1,3,3-tetramethyl 1,1,3,3-Tetramethylbutyl peroxy-2-ethylhexanoate, peroxy-2-ethylhexanoic acid-1,1,2-trimethylpropyl ester, isopropyl peroxycarbonate Butyl ester, third amyl isopropyl carbonate, tert-butyl peroxy-2-ethylhexyl carbonate, peroxyallyl carbonate Tributyl ester, butyl isopropyl peroxycarbonate, 1,1,3,3-tetramethylbutyl isopropyl carbonate, isopropyl carbonate-1,1,2-three Methyl propyl ester, 1,1,3,3-tetramethylbutyl peroxyisophthalate, 1,1,2-trimethylpropyl peroxyisophthalate, tert-butyl peroxybenzoate, etc. Peroxidic compound.

These polymerization initiators may be used singly or in combination of two or more.

The content ratio of the polymerization initiator to the total mass of 100 parts by mass of the first monomer component is, for example, 0.1 part by mass or more, preferably 0.5 part by mass or more, and for example, 13 parts by mass or less, preferably 10 parts by mass. the following.

In the case of solution polymerization, suspension polymerization, or the like, the solvent is not particularly limited as long as it is stable relative to the first monomer component, and for example, a petroleum hydrocarbon solvent such as hexane or mineral oil, for example, An aromatic hydrocarbon solvent such as benzene, toluene or xylene; for example, a ketone solvent such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone or cyclohexanone, for example, methyl acetate or ethyl acetate An ester solvent such as ester, butyl acetate, γ-butyrolactone or propylene glycol monomethyl ether acetate, such as N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl An organic solvent such as an aprotic polar solvent such as hydrazine, N-methylpyrrolidone or pyridine.

Meanwhile, as the solvent, for example, water, for example, an alcohol solvent such as methanol, ethanol, n-propanol, isopropanol or butanol, for example, a glycol ether solvent such as ethylene glycol monoethyl ether or propylene glycol monomethyl ether Water solvent.

In addition, as a petroleum-based hydrocarbon solvent, for example, AF solvent No. 4-7 (manufactured by Nippon Oil Co., Ltd.), for example, is used as an aromatic hydrocarbon solvent. For example, Ink Solvent No. 0 manufactured by Nippon Oil Corporation, Solvesso 100 manufactured by Exxon Chemical Co., Ltd., 150, 200, and the like.

These solvents may be used singly or in combination of two or more.

The mixing ratio of the solvent is not particularly limited and can be appropriately selected depending on the purpose.

The polymerization conditions of the first monomer component vary depending on the type of the first monomer component, the polymerization initiator, the solvent, etc., but the polymerization temperature is, for example, 30 ° C or higher, preferably 60 ° C or higher, and for example, 150 ° C or lower. Preferably, it is 120 ° C or less. Meanwhile, the polymerization time is, for example, 2 hours or longer, preferably 4 hours or longer, and for example, 20 hours or shorter, preferably 8 hours or shorter.

Furthermore, the first monomer component may be added in one portion or in a stepwise manner.

The weight average molecular weight (in terms of polystyrene) of the (A) (meth)acrylic resin thus obtained is, for example, 200,000 or more, preferably 250,000 or more, and for example, 500,000 or less, preferably 450,000 or less.

(A) The weight average molecular weight of the (meth)acrylic resin can provide excellent adhesion as long as it is in the above range.

Meanwhile, the number average molecular weight (in terms of polystyrene) of the (A) (meth)acrylic resin is, for example, 10,000 or more, preferably 12,000 or more, and for example, 50,000 or less, preferably 30,000 or less.

The number average molecular weight of the (A) (meth)acrylic resin can be excellent in adhesion as long as it is in the above range.

Further, the method for measuring the weight average molecular weight and the number average molecular weight is based on the examples described later.

Meanwhile, from the viewpoint of adhesion, the glass transition temperature of the (A) (meth)acrylic resin is, for example, -55 ° C or higher, preferably -40 ° C or higher, and for example, 20 ° C or lower, preferably 10 ° C or lower. .

Further, the glass transition temperature can be calculated by the Fox equation.

The content ratio of the (A) (meth)acrylic resin is, for example, 15% by mass or more, preferably 20% by mass or more, and for example, 90% by mass or less, preferably 80% by mass based on the total mass of the adhesive composition. %the following.

(B) The dispersant is composed of a (meth)acrylic resin having an ionic group.

The ionic group is, for example, an anionic group such as a carboxyl group or a phosphoric acid group; for example, a cationic group such as a tertiary amino group or a quaternary ammonium group.

The tertiary amine group is not particularly limited, but examples thereof include, for example, N,N-dimethylamino group, N,N-diethylamino group, N,N-dipropylamino group, N,N-diisopropylamino, N,N-dibutylamino, N,N-di-isobutylamino, N,N-di-t-butylamino, N,N- An N,N-dialkylamino group such as a di-t-butylamino group or the like.

The tertiary amine group is included in the ionic group for protonation.

Meanwhile, as for the quaternary ammonium group, for example, a quaternizing agent such as an epihalo hydrin, a halogenated benzyl group or a halogenated alkyl group acts on the above tertiary amino group.

These ionic groups may be used alone or in combination of two or more.

Further, the ionic group is preferably selected depending on the type of the metal oxide particles (C) to be described later.

Specifically, in the case of the (C) metal oxide particles-based zirconia and/or titanium oxide described later, the ionic group is preferably a phosphate group.

By using the above combination, the dispersibility of the (C) metal oxide particles can be further improved, and the optical characteristics can be further improved.

Meanwhile, in the case where the metal oxide particles (C) described later are doped with tin oxide of antimony, the ionic group is preferably a tertiary amino group, for example.

By using the above combination, the dispersibility of the (C) metal oxide particles can be further improved, and the optical characteristics can be further improved.

In this way, by selecting an ionic group in accordance with the type of the (C) metal oxide particles described later, the effect of the (C) metal oxide particles can be efficiently found.

The (meth)acrylic resin having such an ionic group can be, for example, a monomer component containing a monomer having an ionic group (hereinafter, a raw material of a (meth)acrylic resin having an ionic group; The monomer component is referred to as a second monomer component).

Examples of the monomer having an ionic group include, for example, a monomer having a carboxyl group, a monomer having a phosphate group, a monomer having a tertiary amino group, a monomer having a quaternary ammonium group, and the like.

As the monomer having a carboxyl group, for example, an α,β-unsaturated carboxylic acid such as (meth)acrylic acid, itaconic acid, maleic acid or fumaric acid or a salt thereof, for example, the above (methyl group) The hydroxyalkyl acrylate and the half esterified product of the acid anhydride and the like are, for example, an α,β-unsaturated carboxylic acid, more preferably (meth)acrylic acid.

For the monomer having a phosphate group, for example, acid phosphoxyethyl (meth)acrylate, acid dioxyphosphoryl polyoxypropylene glycol monomethyl Acid phosphoxy polyoxypropylene glycol monomethacrylate, mono(2-hydroxyethyl (meth)acrylate) phosphate (meth)acrylic acid The ester, for example, is preferably mono(2-hydroxyethyl (meth)acrylic acid) phosphate.

For the monomer having a tertiary amino group, for example, N,N-dimethylaminoethyl (meth)acrylate (alias: 2-dimethylaminoethyl (meth) acrylate) (2-dimethyl amino ethyl methacrylate), N,N-diethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl (meth)acrylate, (meth)acrylic acid N An N,N-dialkylaminoalkyl (meth)acrylate, such as N-di-t-butylaminoethyl ester or N,N-dimethylaminobutyl (meth)acrylate, For example, N,N-dimethylaminoethyl(meth)acrylamide, N,N-diethylaminoethyl(meth)acrylamide, N,N-dimethylaminopropyl N,N-dialkylaminoalkyl(meth)acrylamide or the like of (meth)acrylamide or the like, preferably N,N-dialkylaminoalkyl (meth)acrylate, More preferred is N,N-dimethylaminoethyl (meth)acrylate.

In the case of a monomer containing a quaternary ammonium group, for example, a quaternizing agent (for example, a halogenated propylene oxide, a halogenated benzyl group, a halogenated alkyl group, or the like) is allowed to act on the above-described tertiary group-containing monomer. Specifically, for example, 2-(methacryloxy)ethyltrimethylammonium chloride, 2-(methacryloxy)ethyltrimethylammonium bromide, dimethyl group a (meth) propylene oxyalkyl trialkylammonium salt such as 2-(methacryloxy)ethyltrimethylammonium phosphate, such as methacrylamidopropylpropyltrimethyl chloride a (meth)acryloylaminoalkylalkyltrialkylammonium salt such as ammonium or bromomethylaminopropylpropyltrimethylammonium bromide, such as tetrabutylammonium (meth)acrylate a tetraalkyl acrylate, such as trialkylbenzylammonium (meth) acrylate such as trimethylbenzylammonium (meth) acrylate, etc., preferably exemplified by (meth) propylene decyloxyalkyl The alkylammonium salt is more preferably 2-(methacryloxy)ethyltrimethylammonium chloride.

These monomers having an ionic group may be used singly or in combination of two or more.

Further, the monomer having an ionic group is preferably selected in accordance with the type of the metal oxide particles (C) to be described later.

Specifically, in the case of the (C) metal oxide particles-based zirconia and/or titanium oxide described later, the monomer having an ionic group is preferably a monomer having a phosphate group, for example.

By using the above combination, the dispersibility of the (C) metal oxide particles can be further improved, and the optical characteristics can be further improved.

Meanwhile, in the case where the (C) metal oxide particles are doped with antimony tin oxide, as the monomer having an ionic group, for example, a monomer having a tertiary amino group is preferable.

By using the above combination, the dispersibility of the (C) metal oxide particles can be further improved, and the optical characteristics can be further improved.

In this way, by selecting a monomer having an ionic group in accordance with the type of the (C) metal oxide particles described later, the effect of the (C) metal oxide particles can be efficiently found.

Meanwhile, the second monomer component may further include a copolymerizable monomer (hereinafter, referred to as a second copolymerizable monomer) copolymerizable with a monomer having an ionic group.

As the second copolymerizable monomer, for example, the above-mentioned alkyl (meth)acrylate, the above-mentioned nitrogen-containing monomer (except for the monomer having a tertiary amino group and a quaternary ammonium group) The monomer other than the monomer, the above-mentioned hydroxyl group-containing monomer, the above-described alkane polyol poly(meth)acrylate, the above-mentioned saturated alicyclic group-containing monomer, and the above aromatic vinyl monomer, and further, The above itaconate, the above-mentioned maleate, fumarate, acrylonitrile, methacrylonitrile, vinyl acetate, and the like.

These second copolymerizable monomers may be used singly or in combination of two or more.

As the second copolymerizable monomer, for example, an alkyl (meth)acrylate is preferred.

In the case where the second monomer component contains an alkyl (meth)acrylate, the content of the alkyl (meth)acrylate is, for example, 20% by mass or more, preferably, based on the total mass of the second monomer component. It is 40% by mass or more, more preferably 60% by mass or more, and for example, 98% by mass or less, preferably 95% by mass or less.

Meanwhile, the second copolymerizable monomer preferably contains other copolymerizable monomers (second copolymerizable monomers other than alkyl (meth)acrylate).

In the case where the second monomer component contains another copolymerizable monomer (second copolymerizable monomer other than the alkyl (meth) acrylate), the total mass of the second monomer component is the same as the total mass of the second monomer component. The content ratio of the copolymerizable monomer is, for example, 1% by mass or more, preferably 2% by mass or more, more preferably 5% by mass or more, and for example, 40% by mass or less, preferably 30% by mass or less.

Meanwhile, in the second monomer component, the content ratio of the monomer having an ionic group to the total mass of the second monomer component is, for example, 0.1% by mass or more, preferably 1% by mass or more, and for example 80% by mass or less, preferably 70% by mass or less, more preferably 60% by mass or less.

At the same time, it is preferred that the monomer selected in the second monomer component is at least partially repeated with the monomer species contained in the first monomer component.

Specifically, the second monomer component preferably contains the same kind of alkyl (meth)acrylate as the alkyl (meth)acrylate contained in the first monomer component.

Meanwhile, the second monomer component preferably contains the same kind of monomer as the first copolymerizable monomer contained in the first monomer component.

As a result, once the monomer type as the selected second monomer component is partially overlapped with the monomer type of the selected first monomer component, the dispersibility can be improved.

In the case where a polymerization initiator is present, the (meth)acrylic resin having an ionic group can be obtained by copolymerization by a conventional polymerization method such as solution polymerization, bulk polymerization, or suspension polymerization.

Although not particularly limited, for example, the polymerization initiator is the same as the polymerization initiator used in the above synthetic (A) (meth)acrylic resin.

The content ratio of the polymerization initiator to the total mass of 100 parts by mass of the second monomer component is, for example, 0.1 part by mass or more, preferably 2 parts by mass or more, and for example, 13 parts by mass or less, preferably 10 parts by mass. the following.

Meanwhile, in the case of using solution polymerization, suspension polymerization, or the like, the solvent is, for example, not particularly limited as long as it is stable relative to the second monomer component, for example, the above synthesis (A) (methyl) The solvent used in the acrylic resin.

Further, the mixing ratio of the solvent is not particularly limited and can be appropriately selected depending on the purpose.

The polymerization conditions of the second monomer component vary depending on the type of the second monomer component, the polymerization initiator, the solvent, etc., but the polymerization temperature is, for example, 30 ° C or higher, preferably 60 ° C or higher, and for example, 150 ° C or lower. Preferably, it is 120 ° C or less. Meanwhile, the polymerization time is, for example, 2 hours or longer, preferably 4 hours or longer, and for example, 20 hours or shorter, preferably 8 hours or shorter.

Furthermore, the second monomer component may be added in one portion or in a stepwise manner.

The weight average molecular weight (in terms of polystyrene) of the (meth)acrylic resin having an ionic group obtained in this manner is 200 or more, preferably 1,000 or more, more preferably 4,000 or more, and is preferably 50,000 or less. It is 15,000 or less, more preferably 8,000 or less.

When the weight average molecular weight of the (meth)acrylic resin having an ionic group is in the above range, excellent dispersibility can be obtained.

Meanwhile, the number average molecular weight (in terms of polystyrene) of the (meth)acrylic resin having an ionic group is, for example, 100 or more, preferably 650 or more, and for example, 33,000 or less, preferably 10,000 or less.

When the number average molecular weight of the (meth)acrylic resin having an ionic group is in the above range, excellent adhesion can be obtained.

Further, the method for measuring the weight average molecular weight and the number average molecular weight is based on the examples described later.

The content ratio of the (B) dispersant is, for example, 2% by mass or more, preferably 5% by mass or more, and preferably 30% by mass or less, preferably 20% by mass, based on the total mass (solid content) of the adhesive composition. %the following.

Meanwhile, the content ratio of the (B) dispersant is, for example, 5 parts by mass or more, preferably 8 parts by mass or more, and for example, 50 parts by mass or less, based on 100 parts by mass of the total mass of the (A) (meth)acrylic resin. It is preferably 30 parts by mass or less.

As the (C) metal oxide particles, for example, aluminum oxide, titanium oxide, zinc oxide, zirconium oxide, tin oxide, antimony oxide, antimony oxide, antimony oxide, antimony oxide, indium oxide, antimony pentoxide a metal oxide particle (for example, doped with germanium) obtained by doping a heterogeneous element such as a metal oxide particle or a heterogeneous element such as gallium, germanium, tin, fluorine, phosphorus, or aluminum. Further, for example, a tin oxide compound (barium titanate, calcium titanate, barium titanate) or the like is used as a composite oxide. The crystal structure of the metal oxide is not particularly limited, and may be, for example, any one of a cubic system, a tetragonal system, an orthorhombic system, a monoclinic system, a triclinic system, a hexagonal system, and a trigonal system.

These (C) metal oxide particles may be used singly or in combination of two or more.

At the same time, (C) the metal oxide particles can be appropriately selected in accordance with the physical properties required for the adhesive composition. From the viewpoint of improving the refractive index, for example, titanium oxide or zirconium oxide is preferred. Meanwhile, from the viewpoint of seeking an improvement in the heat insulating effect, for example, tin oxide doped with antimony is preferred.

Meanwhile, the (C) metal oxide particles can be surface-treated by a conventional method as necessary.

These (C) metal oxide particles may be used singly or in combination of two or more.

Although the shape of the (C) metal oxide particles is not particularly limited, for example, a block shape, a spherical shape, a hollow shape, a porous shape, a rod shape, a plate shape, a fiber shape, an indefinite shape, and a mixture thereof Wait.

Meanwhile, the particle diameter of the (C) metal oxide particles is measured by a primary particle diameter (distinguish from the average particle diameter described later), and is, for example, 1 nm or more, preferably 3 nm or more, and for example, 200 nm or less, preferably 90 nm or less. .

In addition, the primary particle diameter is determined by measuring the particle diameters of 100 metal oxide particles using an electron microscope such as a scanning electron microscope (SEM) or a transmission electron microscope (TEM), and calculating an average value.

As long as the primary particle diameter of the (C) metal oxide particles is in the above range, it is easy to handle, and the dispersibility and optical properties of the metal oxide particles can be improved.

The content ratio of the (C) metal oxide particles is, for example, 2% by mass or more, preferably 5% by mass or more, more preferably 10% by mass or more, and for example, 80% by mass or less based on the total mass of the adhesive composition. It is preferably 50% by mass or less, more preferably 40% by mass or less.

Meanwhile, the content ratio of the (C) metal oxide particles is, for example, 5 parts by mass or more, preferably 8 parts by mass or more, and for example, 80 masses, based on 100 parts by mass of the total mass of the (A) (meth)acrylic resin. The amount is preferably 70 parts by mass or less.

Further, the adhesive composition can be obtained by mixing and mixing (A) (meth)acrylic resin, (B) dispersant, and (C) metal oxide particles in the above ratio.

The mixing method is not particularly limited, and a conventional method such as wet mixing or dry mixing may be employed, and wet mixing is preferred.

In the wet mixing, the dispersion medium is not particularly limited, and a conventional dispersion medium can be used, specifically, for example, with (A) (meth)acrylic resin and (B) dispersant. The solvent used in the synthesis is the same solvent, and for example, the above organic solvent is preferred.

These dispersion media may be used alone or in combination of two or more.

From the viewpoint of improving the work efficiency, it is preferred to use a solvent used for preparation of the (A) (meth)acrylic resin and/or (B) dispersant as a dispersion medium.

The mixing ratio of the dispersion medium is appropriately set according to the purpose and use.

Meanwhile, the order of mixing is not particularly limited, and for example, (A) (meth)acrylic resin, (B) dispersant, and (C) metal oxide particles may be mixed at once.

At the same time, (A) (meth)acrylic resin, (B) dispersing agent may be first mixed, and then the obtained mixture may be mixed with (C) metal oxide particles.

Meanwhile, (A) (meth)acrylic resin, (C) metal oxide particles may be first mixed, and then the obtained mixture may be mixed with (B) a dispersing agent.

Meanwhile, the (B) dispersant and the (C) metal oxide particles may be first mixed, and then the resulting mixture may be mixed with the (A) (meth)acrylic resin.

Preferably, the (B) dispersant and (C) metal oxide particles are first mixed, and then the resulting mixture is mixed with (A) (meth)acrylic resin.

More specifically, in this method, a dispersion of metal oxide particles is obtained by mixing and dispersing (B) a dispersing agent and (C) metal oxide particles in the presence of the above-mentioned dispersion medium.

Since (C) metal oxide particles have primary particles and secondary particles, and the particle size of the (C) metal oxide particles in the obtained dispersion is measured by the average particle diameter of the particles, the measurement result usually exceeds 0 nm. For example, it is 200 nm or less, preferably 90 nm or less, more preferably 20 nm or less.

Further, the method for measuring the average particle diameter is based on the examples described later.

The dispersion method is not particularly limited, and for example, a conventional dispersing machine such as a paint shaker, a roll mill, a ball mill, an attritor, a sand mill, a bead mill, or an ultrasonic disperser can be used.

In the case of using a bead mill as a dispersing machine, a conventional dispersion medium such as zirconia beads or glass beads can be used.

The bead diameter of the dispersion medium is not particularly limited, but may be, for example, 10 μm or more, and is, for example, 500 μm or less, preferably 100 μm or less. Furthermore, the filling rate of the dispersion medium can be appropriately set depending on the purpose and use.

Meanwhile, in the case where a bead mill or a ball mill is used as the disperser, the metal oxide particles may be pulverized by the dispersion medium, and the average particle diameter thereof may be adjusted to the above range. In this case, metal oxide particles having an average particle diameter larger than the above range can be charged into the dispersing machine.

Next, in this method, a dispersion of the adhesive composition is obtained by mixing the dispersion of the metal oxide particles obtained above with the (A) (meth)acrylic resin.

The concentration of the nonvolatile component (solid content) in the dispersion of the adhesive composition is, for example, 10% by mass or more, preferably 20% by mass or more, and for example, 50% by mass or less, preferably 40% by mass or less.

Meanwhile, from the viewpoint of adhesion, the glass transition temperature of the nonvolatile component (solid content) of the adhesive composition is, for example, -55 ° C or higher, preferably -40 ° C or higher, and for example, 20 ° C or lower, preferably Below 10 °C.

Further, the glass transition temperature can be calculated by the Fox equation.

Meanwhile, although the adhesive composition can be used as it is, it is preferable to add a hardener.

As the hardener, for example, a crosslinking agent or the like which crosslinks the (A) (meth)acrylic resin, for example, specifically, for example, a polyisocyanate compound.

The polyisocyanate compound is not particularly limited as long as it is a compound having two or more isocyanate groups in the molecule, and examples thereof include, for example, toluene diisocyanate or a hydrogenated product thereof, triphenylmethane triisocyanate, and cyclohexane. A conventional polyisocyanate such as an isocyanate. Meanwhile, as the polyisocyanate compound, for example, a derivative of the above polyisocyanate (for example, a polyol adduct or the like) and a polymer may be used.

These polyisocyanate compounds may be used alone or in combination of two or more.

The blending ratio of the curing agent is, for example, 0.1 part by mass or more, preferably 0.3 part by mass or more, and for example 2 parts by mass or less, preferably 1 part by mass or less, based on 100 parts by mass of the total mass of the adhesive composition.

Meanwhile, the blending ratio of the curing agent is, for example, 0.5 parts by mass or more, preferably 1 part by mass or more, and preferably 10 parts by mass or less, based on 100 parts by mass of the total mass of the (A) (meth)acrylic resin. It is 5 parts by mass or less.

By adding a hardener, it is possible to increase the adhesion of the adhesive composition.

Further, such an adhesive composition contains: (A) a (meth)acrylic resin; (B) a dispersing agent; (C) a metal oxide particle, and because (B) an ionic group in the dispersing agent ( Since the weight average molecular weight of the methyl)acrylic resin is 200 or more and 50,000 or less, the (C) metal oxide particles can be appropriately dispersed, and excellent adhesiveness and optical properties can be obtained.

Therefore, the adhesive composition can be suitably used as an adhesive composition used in optical devices such as various display devices and touch panel devices.

The adhesive composition can be used as it is, and it can also be formed into a layer shape or a sheet shape and used as an adhesive sheet.

That is, the present invention comprises an adhesive sheet formed into a layered shape from the above-mentioned adhesive composition.

The method for producing the adhesive sheet is not particularly limited, and if necessary, for example, after adding a curing agent to the above-mentioned adhesive composition, it is applied to a substrate and dried.

The coating method is not particularly limited, and for example, a roll coater, a bar coater, a knife coater, a Meyer bar coater, an air knife coater can be used. For coating, etc., coating by a machine, or a known coating method such as screen printing, pattern printing, quick-drying printing, brush coating, spray coating, gravure coating, reverse gravure coating, or the like is usually used.

The drying temperature is, for example, 40 ° C or higher, preferably 60 ° C or higher, and is, for example, 180 ° C or lower, preferably 140 ° C or lower, and the drying time is, for example, 1 minute or longer, preferably 3 minutes or longer. Further, for example, it is 60 minutes or shorter, preferably 30 minutes or shorter.

Meanwhile, the film thickness after drying is, for example, 50 nm or more, preferably 500 nm or more, and is, for example, 30 μm or less, preferably 20 μm or less.

In this way, an adhesive sheet can be obtained.

At the same time, in the adhesive sheet, the substrate can be removed as necessary, and at the same time, a conventional release substrate can be laminated on the layer formed of the adhesive composition.

Further, the adhesive sheet can be cured. In such a case, the temperature condition is, for example, 10 ° C or higher, preferably 20 ° C or higher, and for example, 50 ° C or lower, preferably 40 ° C or lower. Meanwhile, the aging time is, for example, 12 hours or longer, preferably 24 hours or longer. And it is, for example, 170 hours or less, preferably 120 hours or less.

Further, since the adhesive sheet is obtained by using the above-described adhesive composition, the adhesive sheet thus obtained is excellent in dispersibility of metal oxide particles, and at the same time, adhesiveness and optical properties (haze value, total light transmittance) ) is also excellent.

Therefore, the adhesive sheet can be suitably used as an adhesive sheet used in optical devices such as various display devices and touch panel devices.

The application is filed in the Japanese Patent Application No. 2015-28031, filed on Jan. 27,,,,,,, [Examples]

Next, the present invention will be described based on examples and comparative examples, but the present invention is not limited by the following examples. In addition, "parts" and "%" are based on quality unless otherwise mentioned. Meanwhile, the numerical values of the examples shown below may be substituted for the numerical values (i.e., the upper limit value or the lower limit value) described in the embodiment.

The measurement method of the physical properties used in the examples, comparative examples, preparation examples, and the like is as follows.

<Average particle diameter> The measurement was carried out under the following conditions using a laser light scattering scattering type particle size distribution measuring apparatus Nanotrac UPA-EX150 (manufactured by Nikkiso Co., Ltd.). Number of measurements: 1 time Measurement time: 180 seconds Measurement temperature: 23 ° C Average particle diameter: cumulative 50% of the volume average particle diameter Determination solvent: Dispersion medium used in the preparation of the dispersion liquid CI value: 0.4 to 0.8 Particle shape: Non-spherical particle penetration: Through sensitivity: Standard filter: Standard (Stand): Normal (Norm) Nano-grade correction: Ineffective <Using the weight average molecular weight (Mw) and number average molecular weight of gel permeation chromatography ( Mn) Measurement > The sample was dissolved in tetrahydrofuran, and the sample concentration was set to 1.0 g/L by a gel permeation chromatography apparatus (GPC, Gel Permeation equipped with a Refractive Index Detector (RID)). Chromatograph) was carried out to obtain a molecular weight distribution of the sample.

Thereafter, based on the obtained chromatogram (chart), standard polystyrene was used as a calibration curve, and the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the sample were calculated. The measurement device and measurement conditions are as follows. Data processing device: Model HLC-8220GPC (manufactured by Tosoh Corporation) Differential refractive index detector: RI detector column built in model HLC-8220GPC: Model TSKgel SuperHZM-H (manufactured by Tosoh Corporation) 2 mobile phases: Flow rate of tetrahydrofuran column: 0.35 mL/min Sample concentration: 1.0 g/L Injection amount: 10 μL Measurement temperature: 40 ° C Molecular weight marker: Standard polystyrene (standard substance manufactured by POLYMER LABORATORIES LTD.) (using polystyrene) Medium-Molecular Weight Calibration Kit (POLYSTYRENE-MEDIUM MOLECULAR WEIGHT CALIBRATION KIT) Preparation of Dispersant (B) Preparation Example 1 (Preparation of Dispersant (B1)) Agitator, condenser, thermometer, inert gas introduction tube, and dropping funnel Into the flask, 100.0 parts of isopropyl alcohol was placed, and after introducing an inert gas (nitrogen gas), the temperature was raised to 65 °C.

Thereafter, a mixture containing the following materials was added dropwise from the funnel with stirring for 2 hours: 7.0 parts of isopropanol as a solvent, 62.0 parts of n-butyl acrylate as a second monomer component, 2-ethylhexyl acrylate 31.0 parts, acid diphosphoryl polyoxypropylene glycol monomethacrylate (monomer having an ionic group, manufactured by Uni-Chemical Co., Ltd., trade name Phosmer PP), 7.0 parts, as a polymerization initiator 5.0 parts of 2-ethylhexanoic acid-1,1,3,3-tetramethylbutyl peroxide (manufactured by Nippon Oil Co., Ltd., trade name PEROCTA® O). Further, 1.3 parts of isopropyl alcohol was added after the mixture was added dropwise. After 1 hour, 0.06 parts of 2-ethylhexanoic acid-1,1,3,3-tetramethylbutyl peroxide (manufactured by Nippon Oil Co., Ltd., trade name PEROCTA® O) was added as a polymerization initiator. One hour later, 0.06 parts of 2-ethylhexanoic acid-1,1,3,3-tetramethylbutyl ester and 1.3 parts of isopropyl alcohol were added, and the mixture was allowed to react for 2 hours. Thereby, a dispersing agent (B1) having a weight average molecular weight of 6,000 and a nonvolatile content of 50% by mass was obtained.

Preparation Example 2 (Preparation of Dispersant (B2)) In addition to using 46.5 parts of n-butyl acrylate, 46.5 parts of 2-ethylhexyl acrylate, and acid diphosphoryl polyoxypropylene glycol monomethacrylate (having ions In the same manner as in Preparation Example 1, a weight average molecular weight of 6,000 and a nonvolatile content of 50% by mass were obtained in the same manner as in Preparation Example 1 except that the monomer of the group was used as a second monomer component. Dispersant (B2).

Preparation Example 3 (Preparation of Dispersant (B3)) In a flask equipped with a stirrer, a condenser, a thermometer, an inert gas introduction tube, and a dropping funnel, 100.0 parts of propylene glycol monomethyl ether acetate (PMA) was placed and introduced into inertia. After the gas (nitrogen), the temperature was raised to 90 °C.

Thereafter, a mixture containing the following materials was added dropwise from the funnel under stirring for 3 hours: 20.0 parts of n-butyl acrylate as a second monomer component, 1.90 parts of isobornyl acrylate, and 18.1 parts of methyl methacrylate, 60.0 parts of 2-dimethylaminoethyl methacrylate (monomer having an ionic group), and 5.0 parts of 2,2'-azobis(2-methylbutyronitrile) as a polymerization initiator Made by Japan Fine Chemical Co., Ltd., trade name ABN-E). After adding the mixture for 30 minutes, 0.3 parts of 2-ethylhexanoic acid-1,1,3,3-tetramethylbutyl peroxide as a polymerization initiator was added, and after 30 minutes, additional peroxide 2 was added. -ethylhexanoic acid-1,1,3,3-tetramethylbutyl ester 0.3 parts, and after 30 minutes, additional 2-ethylhexanoic acid-1,1,3,3-tetramethylbutyl ester 0.3 parts and allowed to react for 2 hours. Thereby, a dispersing agent (B3) having a weight average molecular weight of 6,000 and a nonvolatile content of 50% by mass was obtained.

Preparation Example 4 (Preparation of Dispersant (B4)) In a flask equipped with a stirrer, a condenser, a thermometer, an inert gas introduction tube, and a dropping funnel, 100.0 parts of propylene glycol monomethyl ether was placed and introduced into an inert gas (nitrogen). , heat up to 60 ° C.

In addition to the use of 0.3 parts of 2-ethylhexanoic acid-1,1,3,3-tetramethylbutyl ester (manufactured by Nippon Oil Co., Ltd., trade name PEROCTA® O) as a polymerization initiator, In the same manner as in Example 1, a dispersant (B4) having a weight average molecular weight of 26,000 and a nonvolatile content of 50% by mass was obtained.

Preparation Example 5 (Preparation of Dispersant (B5)) In a flask equipped with a stirrer, a condenser, a thermometer, an inert gas introduction tube, and a dropping funnel, 100.0 parts of propylene glycol monomethyl ether was placed, and an inert gas (nitrogen) was introduced. , heat up to 95 ° C.

In the same manner as in Preparation Example 1, except that 0.5 part of 2,2'-azobis(2-methylbutyronitrile) (manufactured by Nippon Fine Chemical Co., Ltd., trade name: ABN-E) was used as a polymerization initiator. A dispersant (B5) having a weight average molecular weight of 18,000 and a nonvolatile content of 50% by mass was obtained.

Preparation Example 6 (Preparation of Dispersant (B6)) In a flask equipped with a stirrer, a condenser, a thermometer, an inert gas introduction tube, and a dropping funnel, 100.0 parts of propylene glycol monomethyl ether was placed and introduced into an inert gas (nitrogen). , heat up to 110 ° C.

Except that 2,2'-azobis(2-methylbutyronitrile) 1.0 part (manufactured by Nippon Fine Chemical Co., Ltd., trade name ABN-E) was used as a polymerization initiator, in the same manner as in Preparation Example 1. A dispersant (B6) having a weight average molecular weight of 13,000 and a nonvolatile content of 50% by mass was obtained.

Preparation Example 7 (Preparation of Dispersant (B7)) In a flask equipped with a stirrer, a condenser, a thermometer, an inert gas introduction tube, and a dropping funnel, 100.0 parts of propylene glycol monomethyl ether was placed, and an inert gas (nitrogen) was introduced. , heat up to 115 ° C.

In the same manner as in Preparation Example 1, except that 10.0 parts of 2,2'-azobis(2-methylbutyronitrile) (manufactured by Nippon Fine Chemical Co., Ltd., trade name: ABN-E) was used as a polymerization initiator. A dispersant (B7) having a weight average molecular weight of 4,000 and a nonvolatile content of 50% by mass was obtained.

Preparation Example 8 (Preparation of Dispersant (B8)) In a flask equipped with a stirrer, a condenser, a thermometer, an inert gas introduction tube, and a dropping funnel, 300.0 parts of propylene glycol monomethyl ether was placed and introduced into an inert gas (nitrogen). , heat up to 115 ° C.

A weight average molecular weight of 1,000 was obtained in the same manner as in Preparation Example 1, except that 10.0 parts of a third hexyl peroxide benzoate (trade name: PERBUTYL® Z, manufactured by Nippon Oil Co., Ltd.) was used as a polymerization initiator. 50% by mass of a dispersant (B8).

Preparation Example 9 (Preparation of Dispersant (B9)) In addition to 62.0 parts of n-butyl acrylate, 31.0 parts of 2-ethylhexyl acrylate, and ethyl 2-dimethylaminoacrylate (monomer having an ionic group) In the same manner as in Preparation Example 1, 7.0 parts of a dispersant (B9) having a weight average molecular weight of 6,000 and a nonvolatile content of 50% by mass was obtained in the same manner as in Preparation Example 1.

Preparation Example 10 (Preparation of Dispersant (B10)) In addition to using 62.0 parts of n-butyl acrylate, 31.0 parts of 2-ethylhexyl acrylate, and 7.0 parts of methacrylic acid (monomer having an ionic group) as a second single In the same manner as in Preparation Example 1, a dispersant (B10) having a weight average molecular weight of 6,000 and a nonvolatile content of 50% by mass was obtained in the same manner as in Preparation Example 1.

Preparation Example 11 (Preparation of Dispersant (B11)) In a flask equipped with a stirrer, a condenser, a thermometer, an inert gas introduction tube, and a dropping funnel, 60.0 parts of propylene glycol monomethyl ether was placed, and an inert gas (nitrogen) was introduced. , heat up to 75 ° C.

A mixture containing the following materials was added dropwise for 3 hours: 26.4 parts of n-butyl acrylate as a second monomer component, 1.14 parts of isobornyl acrylate, 16.3 parts of methyl methacrylate, 2-dimethylaminoethyl group 16.2 parts of a acrylate (monomer having an ionic group) and 2 parts of 2,2'-azobis(2-methylbutyronitrile) as a polymerization initiator (manufactured by Nippon Fine Chemical Co., Ltd., a product Name ABN-E). After the completion of the dropwise addition, the temperature was raised to 100 ° C, and the following materials were added dropwise for 3 hours: propylene glycol monomethyl ether 40.0 parts, n-butyl acrylate 17.6 parts, isobornyl acrylate 0.76 parts, methyl methacrylate 10.8 parts, 2 - 10.8 parts of dimethylaminoethyl methacrylate (monomer having an ionic group), 2 parts of 2,2'-azobis(2-methylbutyronitrile) as a polymerization initiator (Japan) Fine Chemical Co., Ltd., trade name ABN-E). After 30 minutes, 0.3 parts of 2-ethylhexanoic acid-1,1,3,3-tetramethylbutyl peroxide as a polymerization initiator was added, and after 30 minutes, 2-ethylhexanoic acid peroxide was added. -1,3,3-tetramethylbutyl ester 0.3 parts, and after 30 minutes, additional 2-ethylhexanoic acid-1,1,3,3-tetramethylbutylate as a polymerization initiator The ester was 0.3 parts and allowed to react for 2 hours. Thus, a dispersing agent (B11) having a weight average molecular weight of 48,000 and a nonvolatile content of 50% by mass was obtained.

Preparation Example 12 (Preparation of Dispersant (B12)) In a flask equipped with a stirrer, a condenser, a thermometer, an inert gas introduction tube, and a dropping funnel, 40.0 parts of propylene glycol monomethyl ether was placed, and an inert gas (nitrogen) was introduced. , heat up to 75 ° C.

A mixture containing the following materials was added dropwise for 3 hours: 16.0 parts of n-butyl acrylate as a second monomer component, 0.76 parts of isobornyl acrylate, 10.2 parts of methyl methacrylate, 2-dimethylaminoethyl group 13.0 parts of a acrylate (monomer having an ionic group) and 2 parts of 2,2'-azobis(2-methylbutyronitrile) as a polymerization initiator (manufactured by Nippon Fine Chemical Co., Ltd., a product Name ABN-E). After the completion of the dropwise addition, the temperature was raised to 100 ° C, and the following materials were added dropwise for 3 hours: propylene glycol monomethyl ether 60.0 parts, n-butyl acrylate 24.0 parts, isobornyl acrylate 1.14 parts, methyl methacrylate 15.4 parts, 2 - 19.5 parts of dimethylaminoethyl methacrylate (monomer having an ionic group), 2 parts of 2,2'-azobis(2-methylbutyronitrile) as a polymerization initiator (Japan) Fine Chemical Co., Ltd., trade name ABN-E). After 30 minutes, 0.3 parts of 2-ethylhexanoic acid-1,1,3,3-tetramethylbutyl peroxide as a polymerization initiator was added, and after 30 minutes, 2-ethylhexanoic acid peroxide was added. -1,3,3-tetramethylbutyl ester 0.3 parts, and after 30 minutes, additional 2-ethylhexanoic acid-1,1,3,3-tetramethylbutylate as a polymerization initiator The ester was 0.3 parts and allowed to react for 2 hours. Thus, a dispersing agent (B12) having a weight average molecular weight of 38,000 and a nonvolatile content of 50% by mass was obtained.

Preparation Example 13 (Preparation of Dispersant (B13)) In a flask equipped with a stirrer, a condenser, a thermometer, an inert gas introduction tube, and a dropping funnel, 100.0 parts of propylene glycol monomethyl ether (PM) was placed, and an inert gas was introduced ( After nitrogen gas, the temperature was raised to 85 °C.

In addition to the use of 0.4 parts of 2-ethylhexanoic acid-1,1,3,3-tetramethylbutyl ester (manufactured by Nippon Oil Co., Ltd., trade name PEROCTA® O) as a polymerization initiator, In the same manner as in Example 3, a dispersing agent (B13) having a weight average molecular weight of 30,000 and a nonvolatile content of 50% by mass was obtained.

Preparation Example 14 (Preparation of Dispersant (B14)) In a flask equipped with a stirrer, a condenser, a thermometer, an inert gas introduction tube, and a dropping funnel, 100.0 parts of propylene glycol monomethyl ether (PM) was placed, and an inert gas was introduced ( After nitrogen gas, the temperature was raised to 100 °C.

In addition to using 1.0 part of 2-ethylhexanoic acid-1,1,3,3-tetramethylbutyl ester (manufactured by Nippon Oil Co., Ltd., trade name PEROCTA® O) as a polymerization initiator, In the same manner as in Example 3, a dispersant (B14) having a weight average molecular weight of 13,000 and a nonvolatile content of 50% by mass was obtained.

Preparation Example 15 (Preparation of Dispersant (B15)) In addition to the use of peracetic acid 2-ethylhexanoic acid-1,1,3,3-tetramethylbutyl ester 10.0 parts (manufactured by Nippon Oil Co., Ltd., trade name PEROCTA® O) A dispersant (B15) having a weight average molecular weight of 800 and a nonvolatile content of 50% by mass was obtained in the same manner as in Preparation Example 3 except for the polymerization initiator.

Preparation Example 16 (Preparation of Dispersant (B16)) In a flask equipped with a stirrer, a condenser, a thermometer, an inert gas introduction tube, and a dropping funnel, 100.0 parts of propylene glycol monomethyl ether (PM) was placed, and an inert gas was introduced ( After nitrogen gas, the temperature was raised to 110 °C.

In addition to using 20.0 parts of n-butyl acrylate, 1.90 parts of isobornyl acrylate, 18.1 parts of methyl methacrylate, acid diphosphoryl polyoxypropylene glycol monomethacrylate (monomer having an ionic group) , made by Uni-Chemical Co., Ltd., trade name Phosmer PP), 60.0 parts as the second monomer component, and 5.0 parts of 2,2'-azobis(2-methylbutyronitrile) (Japan Fine Chemical Co., Ltd.) System, trade name ABN-E), 2-ethylhexanoic acid-1,1,3,3-tetramethylbutyl ester 5.0 parts (manufactured by Nippon Oil Co., Ltd., trade name PEROCTA®O) as polymerization A dispersing agent (B16) having a weight average molecular weight of 6,000 and a nonvolatile content of 50% by mass was obtained in the same manner as in Preparation Example 3 except for the starting agent.

Preparation Example 17 (Preparation of Dispersant (B17)) In a flask equipped with a stirrer, a condenser, a thermometer, an inert gas introduction tube, and a dropping funnel, 150.0 parts of propylene glycol monomethyl ether (PM) was placed, and an inert gas was introduced ( After nitrogen gas, the temperature was raised to 110 °C.

In addition to 20.0 parts of n-butyl acrylate, 1.90 parts of isobornyl acrylate, 18.1 parts of methyl methacrylate, 60.0 parts of methacrylic acid as a second monomer component, and 2-ethylhexanoic acid-1 was used. A weight average molecular weight of 6,000, non-volatile, was obtained in the same manner as in Preparation Example 3 except that 3.0 parts of 1,3,3-tetramethylbutyl ester (trade name: PEROCTA® O, manufactured by Nippon Oil Co., Ltd.) was used as a polymerization initiator. 40% by mass of a dispersant (B17).

Preparation Example 18 (Preparation of Dispersant (B18)) In addition to using 46.5 parts of n-butyl acrylate, 46.5 parts of 2-ethylhexyl acrylate, and ethyl 2-dimethylamino acrylate (monomer having an ionic group) 7.0 In the same manner as in Preparation Example 2, a dispersant (B18) having a weight average molecular weight of 6,000 and a nonvolatile content of 50% by mass was obtained in the same manner as in Preparation Example 2.

Preparation Example 19 (Preparation of Dispersant (B19)) In addition to using 46.5 parts of n-butyl acrylate, 46.5 parts of 2-ethylhexyl acrylate, and 7.0 parts of methacrylic acid (monomer having an ionic group) as a second single In the same manner as in Preparation Example 2, a dispersant (B19) having a weight average molecular weight of 6,000 and a nonvolatile content of 50% by mass was obtained in the same manner as in Preparation Example 2.

‧ (B) Preparation of a mixture of a dispersant and (C) metal oxide particles (dispersion) Preparation Example 20 (Preparation of ZrO ₂ dispersion) 18 parts of the dispersant (B1) obtained in Preparation Example 1 10 parts by weight of volatile components, zirconia (Ishihara Sangyo Co., Ltd., trade name: PCS90) as metal oxide particles, 10 parts of isopropanol as a solvent, and 300 parts of 50 μm zirconia beads as a dispersion medium The mixture was placed in a 300 mL bottle, and zirconia was pulverized and dispersed at 60 Hz for 6 hours using a disperser (rocking shaker RS-05W manufactured by Seiwa Giken Co., Ltd.).

Thereafter, the zirconia beads were removed by filtration to obtain a zirconia-dispersed dispersion (ZrO ₂ dispersion).

The nonvolatile content of the obtained ZrO ₂ dispersion was 19.0% by mass, and the average particle diameter of the metal oxide particles was 39 nm.

Further, the content ratio of the dispersing agent (B1) to the dispersion liquid was 9% by mass, and the content ratio of the metal oxide particles (ZrO ₂ ) to the dispersion liquid was 10% by mass.

Preparation Example 21 (Preparation of TiO ₂ dispersion) The dispersant (B2) obtained in Preparation Example 2 was used as a dispersant, and titanium oxide (trade name: MT-05, manufactured by TAYCA Co., Ltd.) was used as the metal oxide particles. A dispersion (TiO ₂ dispersion) in which titanium oxide was dispersed was obtained in the same manner as in Preparation Example 20.

The non-volatile component in the obtained TiO ₂ dispersion was 19.0% by mass, and the average particle diameter of the metal oxide particles was 50 nm.

In addition, the content ratio of the dispersing agent (B2) in the dispersion liquid was 9% by mass, and the content ratio of the metal oxide particles (TiO ₂ ) in the dispersion liquid was 10% by mass.

Preparation Example 22 (Preparation of ATO dispersion) 12 parts of the dispersant (B3) obtained in Preparation Example 3 (6 parts in terms of nonvolatile content), and tin oxide doped as a metal oxide particle (Ishihara Industry Co., Ltd.) Co., Ltd., abbreviation: ATO, trade name SN-100P) 20 parts, 68 parts of isopropanol as a solvent, 300 parts of 100 μm zirconia beads as a dispersion medium were charged into a 300 mL bottle, using a dispersing machine (Seiwa Giken The company's rocking shaker (RS-05W) pulverized and dispersed the metal oxide particles at 60 Hz for 6 hours. Thereafter, the zirconia beads were removed by filtration to obtain a dispersion (ATO dispersion) in which tin oxide doped with antimony was dispersed.

The nonvolatile content in the obtained ATO dispersion was 26.0% by mass, and the average particle diameter of the metal oxide particles (ATO) was 34 nm.

Further, the content ratio of the dispersing agent (B3) to the dispersion liquid was 6% by mass, and the content ratio of the metal oxide particles (ATO) to the dispersion liquid was 20% by mass.

‧ (A) Preparation of (meth)acrylic resin Preparation Example 23 (Preparation of (meth)acrylic resin (A1)) In a flask equipped with a stirrer, a condenser, a thermometer, an inert gas introduction tube, and a dropping funnel, 567.0 parts of ethyl acetate and 544.8 parts of toluene were added as a solvent.

550.1 parts of n-butyl acrylate, 149.4 parts of 2-ethylhexyl acrylate, 72.0 parts of acrylic acid, 50.5 parts of vinyl acetate, 0.18 parts of 1,6-hexanediol diacrylate, 2- as a first monomer component A mixture of 4.2 parts of hydroxyethyl acrylate and 18.1 parts of N,N-dimethylpropenylamine and 13.5 parts of toluene as a solvent (1) was placed in the flask, and an inert gas (nitrogen) was introduced, and the temperature was raised to 80 °C.

Thereafter, a mixture containing the following materials was added dropwise from the funnel with stirring for 1 hour: 229.4 parts of ethyl acetate as a solvent, and 1.35 parts of a third butyl peroxy-2-ethylhexanoate as a polymerization initiator (made by Nippon Oil Co., Ltd., trade name PERBUTYL® O). Thereafter, the temperature was raised to 90 ° C, and after 1 hour, 13.0 parts of toluene as a solvent, 35.0 parts of 2-ethylhexyl acrylate as a first monomer component, and 4.20 parts of 2-hydroxyethyl acrylate were added dropwise over 1 hour. A mixture (2) of 1.3 parts of perbutyl 2-ethylhexanoate as a polymerization initiator. After 1 hour and 45 minutes, 4.06 parts of tert-butyl peroxy-2-ethylhexanoate as a polymerization initiator was added, and after 1 hour, 4.06 parts of tert-butyl peroxy-2-ethylhexanoate was added. And allowed to react for 1 hour and 30 minutes. Thus, a (meth)acrylic resin (A1) having a weight average molecular weight of 290,000, a number average molecular weight of 170,000, and a nonvolatile content of 39% by mass was obtained.

Preparation Example 24 (Preparation of (meth)acrylic resin (A2)) The solvent of the mixture (1) was changed to 512.7 parts of ethyl acetate and 492.6 parts of toluene, and the first monomer component was changed to n-butyl acrylate 568.0. Portion, 166.0 parts of 2-ethylhexyl acrylate, 17.5 parts of acrylic acid, 52.5 parts of vinyl acetate, 0.2 parts of 1,6-hexanediol diacrylate, 4.5 parts of 2-hydroxyethyl acrylate and 17.5 parts of propylene morpholine Further, the toluene as a solvent was changed to 13.45 parts, and the solvent of the mixture (2) was changed to 14.4 parts of toluene, and the first monomer component was changed to 41.5 parts of 2-ethylhexyl acrylate and 2-hydroxy acrylate. A weight average molecular weight of 340,000 and a number average molecular weight of 14,000 were obtained in the same manner as in Preparation Example 23 except that the ethyl ester was changed to 4.5 parts by weight and the polymerization initiator was changed to 1.27 parts of tert-butyl peroxy-2-ethylhexanoate. The (meth)acrylic resin (A2) having a volatile component of 40% by mass.

Preparation Example 25 (Preparation of (meth)acrylic resin (A3)) The solvent of the mixture (1) was changed to 456.5 parts of ethyl acetate and 438.6 parts of toluene, and the first monomer component was changed to n-butyl acrylate 544.4. , 146.9 parts of 2-ethylhexyl acrylate, 15.8 parts of acrylic acid, 47.8 parts of vinyl acetate, 0.17 parts of 1,6-hexanediol diacrylate and 4.0 parts of 2-hydroxyethyl acrylate, and toluene as a solvent Changed to 13.45 parts, and the solvent of the mixture (2) was changed to 14.9 parts of toluene, and the first monomer component was changed to 36.7 parts of 2-ethylhexyl acrylate and 4.0 parts of 2-hydroxy acrylate. A weight average molecular weight of 310,000, a number average molecular weight of 21,000, and a nonvolatile content of 39% by mass were obtained in the same manner as in Preparation Example 23 except that the polymerization initiator was changed to 1.45 parts of dibutyl peroxy-2-ethylhexanoate ( Methyl) acrylic resin (A3).

‧Adhesive Composition and Adhesive Sheet Production Example 1 53 parts of ZrO ₂ dispersion obtained in Preparation Example 20 (4.77 parts of dispersant (B1), 5.3 parts of ZrO ₂ ), and (meth)acrylic acid obtained in Preparation Example 23 47 parts of resin (A1) (18.33 parts in terms of non-volatile content), and CORONATE HL (manufactured by Nippon Polyurethane Industry Co., Ltd., an adduct containing hexamethylene diisocyanate and trimethylolpropane) The mixture was stirred and mixed with 0.2 parts of a 75% ethyl acetate solution to prepare an adhesive composition.

The obtained adhesive composition was applied to a 25 μm polyethylene terephthalate film as a substrate: PET (manufactured by Toray Industries, Inc., trade name Lumilar, (trademark) T-60), and dried. The film thickness after that was 15 μm.

Thereafter, the film was dried in the air at 100 ° C for 5 minutes, and the film was attached using a 75 μm PET film (manufactured by PANAC Co., Ltd., trade name SPPET7501BU) which had been subjected to a release treatment on the surface of the film, and was 40. The mixture was aged for 3 days at ° C to obtain an adhesive sheet 1.

At the same time, the adhesive sheet 2 was produced in the same manner as described above except that the 25 μm PET film as the substrate was replaced with a 50 μm PET film which was subjected to release treatment (trade name: SPPET5003BU, manufactured by PANAC Co., Ltd.).

Example 2 (meth)acrylic resin (A2) obtained by using the TiO ₂ dispersion obtained in Preparation Example 21 (part dispersant (B2) 4.77 parts, TiO ₂ 5.3 parts) as a dispersion liquid and using Preparation Example 24 The adhesive composition, the adhesive sheet 1, and the adhesive sheet 2 were obtained in the same manner as in Example 1 except that 47 parts (18.8 parts in terms of nonvolatile content) were used as the (meth)acrylic resin.

Example 3 A (meth)acrylic resin (A3) 47 obtained by using the ATO dispersion liquid of Preparation Example 22, 53 parts (Dispersant (B3) 3.18 parts, ATO 10.6 parts) as a dispersion liquid, and Preparation Example 25 was used. The adhesive composition, the adhesive sheet 1, and the adhesive sheet 2 were obtained in the same manner as in Example 1 except that the (meth)acrylic resin was used as the (meth)acrylic resin.

Example 4 A ZrO ₂ dispersion liquid was obtained in the same manner as in Preparation Example 20 except that the dispersant (B4) obtained in Preparation Example 4 was blended in an amount of 9 parts in terms of a nonvolatile content.

The nonvolatile content of the obtained ZrO ₂ dispersion was 19.0% by mass, and the average particle diameter of the metal oxide particles was 260 nm.

Further, the content ratio of the dispersant to the dispersion was 9% by mass, and the content of the metal oxide particles (ZrO ₂ ) in the dispersion was 10% by mass.

In addition, 53 parts of the (meth)acrylic resin (A3) obtained by using the ZrO ₂ dispersion obtained above (the dispersing agent (B4) 4.77 parts, ZrO ₂ 5.3 parts) and the preparation example 25 were used. The adhesive composition, the adhesive sheet 1, and the adhesive sheet 2 were obtained in the same manner as in Example 1 except that the volatile component was converted to 18.33 parts.

Example 5 A ZrO ₂ dispersion liquid was obtained in the same manner as in Preparation Example 20 except that the dispersant (B5) obtained in Preparation Example 5 was blended in an amount of 9 parts in terms of a nonvolatile content.

The nonvolatile content of the obtained ZrO ₂ dispersion was 19% by mass, and the average particle diameter of the metal oxide particles was 190 nm.

Further, the content ratio of the dispersant to the dispersion was 9% by mass, and the content of the metal oxide particles (ZrO ₂ ) in the dispersion was 10% by mass.

Further, in place of the use of 53 parts of the ZrO ₂ dispersion obtained above (4.77 parts of dispersant (B5), 5.3 parts of ZrO ₂ ), and 47 parts of (meth)acrylic resin (A3) obtained in Preparation Example 25 (by non- The adhesive composition, the adhesive sheet 1, and the adhesive sheet 2 were obtained in the same manner as in Example 1 except that the volatile component was converted to 18.33 parts.

(Example 6) A ZrO ₂ dispersion liquid was obtained in the same manner as in Preparation Example 20 except that the dispersant (B6) obtained in Preparation Example 6 was blended in an amount of 9 parts in terms of a nonvolatile content.

The nonvolatile content of the obtained ZrO ₂ dispersion was 19.0% by mass, and the average particle diameter of the metal oxide particles was 50 nm.

Further, the content ratio of the dispersant to the dispersion was 9% by mass, and the content of the metal oxide particles (ZrO ₂ ) in the dispersion was 10% by mass.

Further, in place of the use of 53 parts of the ZrO ₂ dispersion obtained above (4.77 parts of dispersant (B6), 5.3 parts of ZrO ₂ ), and 47 parts of (meth)acrylic resin (A3) obtained in Preparation Example 25 (by non- The adhesive composition, the adhesive sheet 1, and the adhesive sheet 2 were obtained in the same manner as in Example 1 except that the volatile component was converted to 18.33 parts.

Example 7 In addition to the use of the ZrO ₂ dispersion obtained in Preparation Example 20, 53 parts (dispersing agent (B1) 4.77 parts, ZrO ₂ 5.3 parts), and the (meth)acrylic resin (A3) obtained in Preparation Example 25 (47 parts) ( The adhesive composition, the adhesive sheet 1, and the adhesive sheet 2 were obtained in the same manner as in Example 1 except that the (meth)acrylic resin was used as the (meth)acrylic resin.

(Example 8) A ZrO ₂ dispersion liquid was obtained in the same manner as in Preparation Example 20 except that the dispersant (B7) obtained in Preparation Example 7 was blended in an amount of 9 parts in terms of a nonvolatile content.

The nonvolatile content of the obtained ZrO ₂ dispersion was 19.0% by mass, and the average particle diameter of the metal oxide particles was 50 nm.

Further, the content ratio of the dispersant to the dispersion was 9% by mass, and the content of the metal oxide particles (ZrO ₂ ) in the dispersion was 10% by mass.

Further, in place of the use of 53 parts of the ZrO ₂ dispersion obtained above (4.77 parts of dispersant (B7), 5.3 parts of ZrO ₂ ), and 47 parts of (meth)acrylic resin (A3) obtained in Preparation Example 25 (by non- The adhesive composition, the adhesive sheet 1, and the adhesive sheet 2 were obtained in the same manner as in Example 1 except that the volatile component was converted to 18.33 parts.

(Example 9) A ZrO ₂ dispersion liquid was obtained in the same manner as in Preparation Example 20 except that the dispersant (B8) obtained in Preparation Example 8 was blended in an amount of 9 parts in terms of a nonvolatile content.

The nonvolatile content of the obtained ZrO ₂ dispersion was 19.0% by mass, and the average particle diameter of the metal oxide particles was 70 nm.

Further, the content ratio of the dispersant to the dispersion was 9% by mass, and the content of the metal oxide particles (ZrO ₂ ) in the dispersion was 10% by mass.

Further, in place of the use of 53 parts of the ZrO ₂ dispersion obtained above (4.77 parts of dispersant (B8), 5.3 parts of ZrO ₂ ), and 47 parts of (meth)acrylic resin (A3) obtained in Preparation Example 25 (by non- The adhesive composition, the adhesive sheet 1, and the adhesive sheet 2 were obtained in the same manner as in Example 1 except that the volatile component was converted to 18.33 parts.

(Example 10) A ZrO ₂ dispersion liquid was obtained in the same manner as in Preparation Example 20 except that the dispersant (B9) obtained in Preparation Example 9 was blended in an amount of 9 parts in terms of a nonvolatile content.

The nonvolatile content of the obtained ZrO ₂ dispersion was 19.0% by mass, and the average particle diameter of the metal oxide particles was 40 nm.

Further, the content ratio of the dispersant to the dispersion was 9% by mass, and the content of the metal oxide particles (ZrO ₂ ) in the dispersion was 10% by mass.

Further, in place of the use of 53 parts of the ZrO ₂ dispersion obtained above (4.77 parts of dispersant (B9), 5.3 parts of ZrO ₂ ), and 47 parts of (meth)acrylic resin (A3) obtained in Preparation Example 25 (by non- The adhesive composition, the adhesive sheet 1, and the adhesive sheet 2 were obtained in the same manner as in Example 1 except that the volatile component was converted to 18.33 parts.

Example 11 A ZrO ₂ dispersion liquid was obtained in the same manner as in Preparation Example 20 except that the dispersant (B10) obtained in Preparation Example 10 was blended in an amount of 9 parts in terms of a nonvolatile content.

The nonvolatile content of the obtained ZrO ₂ dispersion was 19.0% by mass, and the average particle diameter of the metal oxide particles was 40 nm.

Further, the content ratio of the dispersant to the dispersion was 9% by mass, and the content of the metal oxide particles (ZrO ₂ ) in the dispersion was 10% by mass.

In addition, 53 parts of the (meth)acrylic resin (A3) obtained by using the ZrO ₂ dispersion obtained above (the dispersing agent (B10) 4.77 parts, ZrO ₂ 5.3 parts) and the preparation example 25 were used. The adhesive composition, the adhesive sheet 1, and the adhesive sheet 2 were obtained in the same manner as in Example 1 except that the volatile component was converted to 18.33 parts.

[Example 12] An ATO dispersion liquid was obtained in the same manner as in Preparation Example 22 except that the dispersant (B11) obtained in Preparation Example 11 was blended in an amount of 6 parts in terms of a nonvolatile content.

The nonvolatile content in the obtained ATO dispersion was 15.0% by mass, and the average particle diameter of the metal oxide particles (ATO) was 50 nm.

Further, the content ratio of the dispersant to the dispersion was 5% by mass, and the content of the metal oxide particles (ATO) in the dispersion was 10% by mass.

Further, in addition to the use of 54 parts of the ATO dispersion obtained above (2.7 parts of dispersant (B11), 5.4 parts of ATO), and 46 parts of (meth)acrylic resin (A3) obtained using Preparation Example 25 (non-volatile The adhesive composition, the adhesive sheet 1, and the adhesive sheet 2 were obtained in the same manner as in Example 1 except that the composition was changed to 17.94 parts.

(Example 13) An ATO dispersion liquid was obtained in the same manner as in Preparation Example 22 except that the dispersant (B12) obtained in Preparation Example 12 was blended in an amount of 6 parts in terms of a nonvolatile content.

The nonvolatile content in the obtained ATO dispersion was 14.0% by mass, and the average particle diameter of the metal oxide particles (ATO) was 50 nm.

Further, the content ratio of the dispersant to the dispersion was 4% by mass, and the content of the metal oxide particles (ATO) in the dispersion was 10% by mass.

Further, in addition to the use of 54 parts of the ATO dispersion obtained above (2.16 parts of dispersant (B12), 5.4 parts of ATO), and 46 parts of (meth)acrylic resin (A3) obtained using Preparation Example 25 (nonvolatile The adhesive composition, the adhesive sheet 1, and the adhesive sheet 2 were obtained in the same manner as in Example 1 except that the composition was changed to 17.94 parts.

[Example 14] An ATO dispersion liquid was obtained in the same manner as in Preparation Example 22 except that the dispersant (B13) obtained in Preparation Example 13 was blended in an amount of 6 parts in terms of a nonvolatile content.

The nonvolatile content in the obtained ATO dispersion was 13.00% by mass, and the average particle diameter of the metal oxide particles (ATO) was 60 nm.

Further, the content ratio of the dispersant to the dispersion was 3% by mass, and the content of the metal oxide particles (ATO) in the dispersion was 10% by mass.

Further, in addition to the use of 53 parts of the ATO dispersion obtained above (1.59 parts of dispersant (B13), 5.3 parts of ATO), and 47 parts of (meth)acrylic resin (A3) obtained using Preparation Example 25 (nonvolatile The adhesive composition, the adhesive sheet 1, and the adhesive sheet 2 were obtained in the same manner as in Example 1 except that the composition was converted to 18.33 parts.

[Example 15] An ATO dispersion liquid was obtained in the same manner as in Preparation Example 22 except that the dispersant (B14) obtained in Preparation Example 14 was blended in an amount of 6 parts in terms of a nonvolatile content.

The nonvolatile content in the obtained ATO dispersion was 13.00% by mass, and the average particle diameter of the metal oxide particles (ATO) was 50 nm.

Further, the content ratio of the dispersant to the dispersion was 3% by mass, and the content of the metal oxide particles (ATO) in the dispersion was 10% by mass.

Further, in addition to the use of 53 parts of the ATO dispersion obtained above (1.59 parts of dispersant (B14), 5.3 parts of ATO), and 47 parts of (meth)acrylic resin (A3) obtained using Preparation Example 25 (non-volatile The adhesive composition, the adhesive sheet 1, and the adhesive sheet 2 were obtained in the same manner as in Example 1 except that the composition was converted to 18.33 parts.

[Example 16] An ATO dispersion liquid was obtained in the same manner as in Preparation Example 22 except that the dispersant (B15) obtained in Preparation Example 15 was blended in an amount of 6 parts in terms of a nonvolatile content.

The nonvolatile content in the obtained ATO dispersion was 13.00% by mass, and the average particle diameter of the metal oxide particles (ATO) was 50 nm.

Further, the content ratio of the dispersant to the dispersion was 3% by mass, and the content of the metal oxide particles (ATO) in the dispersion was 10% by mass.

Further, in addition to the use of 53 parts of the ATO dispersion obtained above (1.59 parts of dispersant (B15), 5.3 parts of ATO), and 47 parts of (meth)acrylic resin (A3) obtained using Preparation Example 25 (non-volatile The adhesive composition, the adhesive sheet 1, and the adhesive sheet 2 were obtained in the same manner as in Example 1 except that the composition was converted to 18.33 parts.

(Example 17) An ATO dispersion liquid was obtained in the same manner as in Preparation Example 22 except that the dispersant (B16) obtained in Preparation Example 16 was blended in an amount of 6 parts in terms of a nonvolatile content.

The nonvolatile content in the obtained ATO dispersion was 13.00% by mass, and the average particle diameter of the metal oxide particles (ATO) was 300 nm.

Further, the content ratio of the dispersant to the dispersion was 3% by mass, and the content of the metal oxide particles (ATO) in the dispersion was 10% by mass.

Further, in addition to the use of 53 parts of the ATO dispersion obtained above (1.59 parts of dispersant (B16), 5.3 parts of ATO), and 47 parts of (meth)acrylic resin (A3) obtained using Preparation Example 25 (non-volatile The adhesive composition, the adhesive sheet 1, and the adhesive sheet 2 were obtained in the same manner as in Example 1 except that the composition was converted to 18.33 parts.

[Example 18] An ATO dispersion liquid was obtained in the same manner as in Preparation Example 22 except that the dispersant (B17) obtained in Preparation Example 17 was blended in an amount of 6 parts in terms of a nonvolatile content.

The nonvolatile content in the obtained ATO dispersion was 13.00% by mass, and the average particle diameter of the metal oxide particles (ATO) was 300 nm.

Further, the content ratio of the dispersant to the dispersion was 3% by mass, and the content of the metal oxide particles (ATO) in the dispersion was 10% by mass.

Further, in addition to the use of 53 parts of the ATO dispersion obtained above (1.59 parts of dispersant (B17), 5.3 parts of ATO), and 47 parts of (meth)acrylic resin (A3) obtained using Preparation Example 25 (non-volatile The adhesive composition, the adhesive sheet 1, and the adhesive sheet 2 were obtained in the same manner as in Example 1 except that the composition was converted to 18.33 parts.

Example 19 A TiO ₂ dispersion liquid was obtained in the same manner as in Preparation Example 21 except that the dispersing agent (B18) obtained in Preparation Example 18 was used as a dispersing agent.

The non-volatile component in the obtained TiO ₂ dispersion was 19% by mass, and the average particle diameter of the metal oxide particles was 40 nm.

Further, the content ratio of the dispersant to the dispersion was 9% by mass, and the content of the metal oxide particles (TiO ₂ ) in the dispersion was 10% by mass.

Further, in addition to the use of 53 parts of the TiO ₂ dispersion obtained above (4.77 parts of dispersant (B18), 5.3 parts of TiO ₂ ), and 47 parts of (meth)acrylic resin (A3) obtained in Preparation Example 25 (by non- The adhesive composition, the adhesive sheet 1, and the adhesive sheet 2 were obtained in the same manner as in Example 1 except that the volatile component was converted to 18.33 parts.

Example 20 A TiO ₂ dispersion liquid was obtained in the same manner as in Preparation Example 21 except that the dispersant (B19) obtained in Preparation Example 19 was used as a dispersant.

The non-volatile component in the obtained TiO ₂ dispersion was 19% by mass, and the average particle diameter of the metal oxide particles was 50 nm.

Further, the content ratio of the dispersant to the dispersion was 9% by mass, and the content of the metal oxide particles (TiO ₂ ) in the dispersion was 10% by mass.

In addition, 53 parts of the (meth)acrylic resin (A3) obtained by using the TiO ₂ dispersion obtained above (the dispersing agent (B19) 4.77 parts, TiO ₂ 5.3 parts) and the preparation example 25 were used. The adhesive composition, the adhesive sheet 1, and the adhesive sheet 2 were obtained in the same manner as in Example 1 except that the volatile component was converted to 18.33 parts.

Comparative Example 1 A commercially available dispersant (trade name: Solsperse 56000, polyester resin-based dispersant, manufactured by Avecia, melting point: 55 ° C, acid value: 23 mg KOH/g) was blended in an amount of 9 parts in terms of nonvolatile content, and was dispersed. A ZrO ₂ dispersion liquid was obtained in the same manner as in Preparation Example 20 except for the agent.

Further, the content ratio of the dispersant to the dispersion was 9% by mass, and the content of the metal oxide particles (ZrO ₂ ) in the dispersion was 10% by mass.

Further, in the same manner as in Example 1, except that 53 parts of the ZrO ₂ dispersion obtained above (4.77 parts of a commercially available dispersant and 5.3 parts of ZrO ₂ ) was used, an adhesive composition, an adhesive sheet 1 and adhesion were obtained. Slice 2.

Evaluation The adhesive strength of the adhesive sheet 1 was evaluated as shown in the following method. At the same time, the optical properties of the adhesive sheet 2 were evaluated. Further, the dispersibility when the adhesive composition (the composition before the formation of the adhesive sheet) was used was evaluated. The results of the evaluation are shown in Tables 1 and 2. (1) Adhesive strength of the adhesive sheet The PET film after the 75 μm peeling treatment of the adhesive sheet 1 was peeled off, and the adhesive force of the adhesive sheet was measured based on JIS Z0237 (2009).

That is, the obtained adhesive sheet is cut into 25mm x 100mm, and then placed on a stainless steel plate (SUS304BA plate), and it is used twice by using a 2kg rubber roller in an atmosphere of 23° C. and a relative humidity of 50%. It is crimped to make a test piece.

Further, the test piece was allowed to stand in the same atmosphere for 30 minutes, and then subjected to a 180-degree peeling test under the conditions of a peeling speed of 0.3 m/min.

At the same time, it was confirmed that the adhesion failure (that is, the interface peeling) was ○ at the time of peeling, and the adhesion was confirmed to be ╳ at the time of peeling. (2) Optical characteristics (haze value and transmittance) The PET film after the 75 μm peeling treatment of the adhesive sheet 2 was peeled off, and then the adhesive sheet 2 was attached to the glass plate, and the adhesive sheet 2 was peeled off by 50 μm. The PET film was peeled off, and then the haze value and the total light transmittance were measured using a haze value meter. The measurement was carried out using a haze value meter NDH2000 manufactured by Nippon Denshoku Industries Co., Ltd. The results obtained are shown together in the table.

In addition, the haze value is ○ when it is 2% or less, Δ when it is more than 2% but less than 4%, and ╳ when it is 4% or more. (3) Dispersibility The adhesive composition was allowed to stand at 25 ° C for 2 weeks, and its dispersibility was evaluated by visual observation. The results are shown in Tables 1 and 2.

In addition, the evaluation criteria are as follows: ◎・・・The precipitation of metal oxide particles was not confirmed after 6 months. ○・・・The precipitation of metal oxide particles was not confirmed after one month. △・・・The precipitation of metal oxide particles was not confirmed after 2 weeks. ╳・・・The precipitation of metal oxide particles was confirmed after 2 weeks.

Table 1

Table 2

Further, the single system containing a phosphate group shown in the table represents an acidic diphosphorus oxide polyoxypropylene glycol monomethacrylate (a monomer having an ionic group, manufactured by Uni-Chemical Co., Ltd.) , the trade name Phosmer PP).

From the above results, it is understood that when a dispersant of a (meth)acrylic resin having an ionic group is used as the adhesive composition, the use is ionic compared to the case of using a polyester resin-based dispersant. The dispersing agent of the (meth)acrylic resin of the group can increase the haze value of the adhesive composition. It is presumed that this is because a dispersant of a (meth)acrylic resin having an ionic group and a dispersant of a (meth)acrylic resin having an ionic group are compared with a dispersant of a polyester resin. A) The compatibility of the (meth)acrylic resin is high, and the metal oxide particles are more preferably dispersed in the adhesive composition.

no.

no

no.

Claims (4)

An adhesive composition comprising: (A) a (meth)acrylic resin; (B) a dispersing agent; (C) a metal oxide particle; wherein the (B) dispersing agent has an ionic group and The (meth)acrylic resin having a weight average molecular weight of 200 or more and 50,000 or less is composed. The adhesive composition according to claim 1, wherein the ionic group is a phosphate group, and the (C) metal oxide particles are zirconia and/or titanium oxide. The adhesive composition according to claim 1, wherein the ionic group is a tertiary amine group, and the (C) metal oxide particles are doped with antimony tin oxide. An adhesive sheet formed by forming the adhesive composition according to any one of claims 1 to 3 into a layer.