KR20240062715A - Adhesive composition, adhesive sheet and image display device prepared from the same - Google Patents

Abstract

The present invention relates to an adhesive composition, and more specifically, to an adhesive composition that includes an acrylic copolymer and a compound containing at least one aromatic ring and has a high refractive index, and has a high refractive index when formed as an adhesive layer. The adhesive sheet formed from the adhesive composition of the present invention has a low glass transition temperature and a high refractive index, so an image display device may not include a separate high refractive index pattern layer.

Description

Adhesive composition, adhesive sheet manufactured therefrom, and image display device {ADHESIVE COMPOSITION, ADHESIVE SHEET AND IMAGE DISPLAY DEVICE PREPARED FROM THE SAME}

The present invention relates to an adhesive composition, an adhesive sheet manufactured therefrom, and an image display device. More specifically, the present invention relates to a pressure-sensitive adhesive composition containing an acrylic copolymer, a pressure-sensitive adhesive sheet manufactured therefrom, and an image display device.

For example, an adhesive or an adhesive sheet may be used to bond a display panel of an image display device such as a liquid crystal display (LCD) device, an organic light emitting display (OLED) device, and various optical structures or circuit structures. The adhesive needs to have improved transparency and excellent adhesive strength so as not to deteriorate the optical properties of the image display device.

For example, the adhesive may be provided between the display panel and/or touch panel and the optical structure to adhere the two devices.

However, a step is generated due to the patterning of the sensing electrode included in the display panel or the touch sensor layer, so an encapsulation layer is required to be placed on the display panel or the touch sensor.

A silicon-nitrogen material with a refractive index of about 2.0 can be used as a material for the encapsulation layer. However, in this case, the encapsulation layer has a large refractive index difference from the adhesive for a polarizing plate, which has a refractive index of about 1.47, so the interfacial reflectance may increase and luminance may decrease.

To solve this problem, a process of separately coating a high refractive index layer between the encapsulation layer and the adhesive for the polarizer is widely used. However, in this case, problems such as increased thickness of the image display device and complicated process conditions may occur.

Accordingly, there is a demand for the development of an adhesive for polarizing plates with high refractive properties so that a separate high refractive layer is not required.

For example, Korean Patent Publication No. 2010-0039274 discloses an adhesive for a polarizing plate applied to an image display device, but does not secure the high refractive properties described above.

Korean Patent Publication No. 2010-0039274

One object of the present invention is to provide an adhesive composition capable of forming an adhesive layer with improved high refractive properties.

One object of the present invention is to provide an adhesive sheet having high refractive properties and an image display device including the same.

1. Acrylic copolymer; and a compound containing at least one aromatic ring and having a refractive index of 1.55 or higher, wherein the adhesive layer formed from the adhesive composition has a refractive index of 1.50 or higher.

2. The adhesive composition of 1 above, wherein the acrylic copolymer includes a repeating unit derived from an acrylic monomer, and the homopolymer of the acrylic monomer has a refractive index of 1.50 or more.

3. In 2 above, the acrylic monomer is pentabromophenyl (meth)acrylate, 2-(naphthalen-2-yloxy)ethyl (meth)acrylate, 2-(naphthalen-2-ylthio)ethyl ( Meth)acrylate, 1-ethoxylated phenol (meth)acrylate, biphenylmethyl (meth)acrylate, phenylphenol ethoxy (meth)acrylate, phenoxybenzyl (meth)acrylate, phenoxyethyl ( An adhesive composition comprising at least one of meth)acrylate and 1-pyrenemethyl (meth)acrylate.

4. The adhesive composition of 1 above, wherein the compound includes a compound having a molecular weight of 150 to 10,000 g/mol.

5. The adhesive composition of 1 above, wherein the compound includes a compound represented by the following formula (1):

[Formula 1]

R ₁ -L-Ar ₁

In Formula 1, L is a direct bond, a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, an ether group, a sulfide group, an amide group, or a substituted or unsubstituted group containing 1 to 10 carbon atoms including an ether group, a sulfide group, or an amide group. is a hydrocarbon group, and R ₁ is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms; A substituted or unsubstituted hydrocarbon group having 1 to 10 carbon atoms, including an ether group, a sulfide group, or an amide group; A substituted or unsubstituted cycloalkyl group having 3 to 12 carbon atoms; A substituted or unsubstituted heteroaryl group having 4 to 12 carbon atoms; (meth)acrylate group; or -Ar ₂ , and Ar ₁ and Ar ₂ are each independently a substituted or unsubstituted aryl group having 6 to 14 carbon atoms or a C 4 to 12 aryl group substituted with at least one aromatic ring or fused with at least one aromatic ring. It is a heteroaryl group.

6. The method of claim 5 above, wherein Ar ₁ and Ar ₂ each independently include two or more substituted or unsubstituted aromatic rings,

Two or more aromatic rings are directly bonded; or fused together; An adhesive composition linked to a substituted or unsubstituted hydrocarbon group having 1 to 10 carbon atoms, including a substituted or unsubstituted alkylene group, an ether group, a sulfide group, an amide group or an ether group, a sulfide group or an amide group.

7. In 5 above, Ar ₁ and Ar ₂ are each independently a substituted or unsubstituted naphthyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted carbazole group, or a substituted or unsubstituted phenoxy group. Phenyl group, adhesive composition.

8. The adhesive composition of 1 above, wherein the compound includes at least one of the compounds represented by the following formulas 2 to 10:

[Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

[Formula 6]

[Formula 7]

[Formula 8]

[Formula 9]

[Formula 10]

9. The adhesive composition of 1 above, wherein the compound is contained in an amount of 0.1 to 20 parts by weight based on 100 parts by weight of the acrylic copolymer.

10. The adhesive composition according to 1 above, further comprising at least one of a photoinitiator and a heat curing agent.

11. An adhesive sheet comprising an adhesive layer formed from the adhesive composition of 1 above.

12. Display panel; a touch sensor layer disposed on the display panel; A polarizing plate disposed on the touch sensor layer; and an adhesive layer formed between the touch sensor layer and the polarizing plate and made of the adhesive composition of 1 above.

13. The method of 12 above, wherein the touch sensor layer includes a base layer and touch sensing electrodes arranged on the base layer, and the adhesive layer fills the space between the touch sensing electrodes and is in direct contact with the polarizing plate. , image display device.

The adhesive composition according to embodiments of the present invention includes a compound containing at least one aromatic ring and having a refractive index of 1.55 or more. For example, the compound may reduce the elastic modulus and glass transition temperature (Tg) of the adhesive composition, while maintaining or increasing high refractive index characteristics by containing an aromatic ring. In this case, a separate high refractive index pattern layer for correcting the difference in refractive index between the sensing electrode and the optical member (eg, polarizer) in the image display device to be described later may be unnecessary. Accordingly, the process is simplified, process costs are reduced, and the thickness of the image display device can be reduced.

In some embodiments, the acrylic copolymer may include a repeating unit derived from an acrylic monomer having a homopolymer refractive index of 1.50 or more. Accordingly, high refractive index characteristics of the adhesive composition containing the acrylic copolymer can be realized.

1 is a schematic cross-sectional view illustrating an adhesive sheet according to example embodiments.
Figure 2 is a schematic cross-sectional view for explaining an image display device according to example embodiments.

Embodiments of the present invention provide an adhesive composition that includes an acrylic copolymer and a compound containing at least one aromatic ring and having a refractive index of 1.55 or more, and maintains or improves the elastic modulus and glass transition temperature while realizing high refractive index characteristics. Additionally, a pressure-sensitive adhesive sheet and an image display device formed from the pressure-sensitive adhesive composition are provided.

Hereinafter, the present invention will be described in detail.

<Adhesive composition>

The adhesive composition according to embodiments of the present invention includes an acrylic copolymer. For example, excellent adhesive properties and durability can be achieved through the acrylic copolymer.

In some embodiments, the acrylic copolymer includes a repeating unit derived from an acrylic monomer, and the refractive index of the homopolymer of the acrylic monomer may be 1.50 or more or 1.51 or more. Accordingly, high refractive index characteristics of the adhesive composition containing the acrylic copolymer can be realized.

For example, the acrylic monomer may be a (meth)acrylate monomer, but is not limited thereto. As used in this application, the term “(meth)acrylate” is used to encompass acrylate or methacrylate.

In some embodiments, the acrylic monomer having a homopolymer refractive index of 1.50 or more is pentabromophenyl (meth)acrylate, 2-(naphthalen-2-yloxy)ethyl (meth)acrylate, 2-(naphthalene- 2-ylthio)ethyl (meth)acrylate, 1-ethoxylated phenol (meth)acrylate, phenylphenol ethoxy (meth)acrylate, phenoxybenzyl (meth)acrylate, phenoxyethyl (meth) It may include at least one of acrylate, biphenylmethyl (meth)acrylate, and 1-pyrenemethyl (meth)acrylate.

In some embodiments, the acrylic monomer may include an acrylic monomer having a hydrocarbon group of 1 to 20 carbon atoms. The acrylic monomer having a hydrocarbon group having 1 to 20 carbon atoms may be a (meth)acrylate monomer.

The hydrocarbon group may include, for example, an aliphatic hydrocarbon group and an aromatic hydrocarbon group. The hydrogen atom contained in the hydrocarbon group may be substituted with an alkyl group, halogen atom, alkoxy group, phenoxy group, etc., and -CH ₂ - contained in the hydrocarbon group may be a hetero atom such as an oxygen atom, a sulfur atom, a nitrogen atom, or the like. It may be substituted with -(CH ₂ CH ₂ O)m-. In this case, m may be 1 to 4.

In some embodiments, the acrylic monomer having a hydrocarbon group having 1 to 20 carbon atoms is methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, and isopropyl (meth)acrylate. , n-butyl (meth)acrylate, sec-butyl (meth)acrylate, t-butyl (meth)acrylate, isobutyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, isobornyl acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n -Decyl (meth)acrylate, isodecyl (meth)acrylate, n-dodecyl (meth)acrylate, n-tridecyl (meth)acrylate, n-tetradecyl (meth)acrylate, pentafluorooctyl Contains at least one selected from the group consisting of acrylate, 2-ethylhexyldiglycol acrylate, nonylphenol (4 moles of ethylene oxide modified) acrylate, and 6-(1-naphthyloxy)-1-hexyl acrylate. It may be, and in terms of ease of availability, 2-ethylhexyl (meth)acrylate is preferable.

In some embodiments, the acrylic monomer may be included in 80 to 99 parts by weight based on 100 parts by weight of the total monomers used to produce the acrylic copolymer. Accordingly, it is possible to secure sufficient adhesion and adhesion of the adhesive composition and prevent degradation of durability due to reduced cohesion.

In some embodiments, the acrylic copolymer may further include a crosslinkable monomer copolymerizable with the acrylic monomer.

For example, the crosslinkable monomers include sulfonic acid group-containing monomers, phosphoric acid group-containing monomers, cyano group-containing monomers, vinyl esters, aromatic vinyl compounds, carboxyl group-containing monomers, acid anhydride group-containing monomers, hydroxy group-containing monomers, amide group-containing monomers, It may include an amine group-containing monomer, an imide group-containing monomer, an epoxy group-containing monomer, or an ether group-containing monomer. These may be used alone or in combination of two or more. Examples of the sulfonic acid group-containing monomer include styrenesulfonic acid, allylsulfonic acid, 2-(meth)acrylamido-2-methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, sulfopropyl (meth)acrylate, (meth)acrylate. ) Acryloyloxynaphthalenesulfonic acid, sodium vinylsulfonate, etc. can be mentioned.

Examples of the phosphoric acid group-containing monomer include 2-hydroxyethyl acryloyl phosphate.

Examples of the cyano group-containing monomer include (meth)acrylonitrile.

Examples of the vinyl esters include vinyl acetate, vinyl propionate, and vinyl laurate.

Examples of the aromatic vinyl compounds include styrene, chlorostyrene, chloromethylstyrene, α-methylstyrene, and other substituted styrenes.

Examples of the carboxyl group-containing monomer include monobasic acids such as (meth)acrylic acid, crotonic acid, isocrotonic acid, carboxyethyl (meth)acrylate, and carboxypentyl (meth)acrylate; Dibasic acids such as maleic acid, itaconic acid, and fumaric acid, and their monoalkyl esters; 3-(meth)acryloylpropionic acid; Succinic anhydride ring-opening adduct of 2-hydroxyalkyl (meth)acrylate having 2 to 3 carbon atoms in the alkyl group, and succinic anhydride ring-opening adduct of hydroxyalkylene glycol (meth)acrylate having 2 to 4 carbon atoms in the alkylene group. , a compound obtained by ring-opening addition of succinic anhydride to a caprolactone adduct of 2-hydroxyalkyl (meth)acrylate having 2 to 3 carbon atoms in the alkyl group, and preferably (meth)acrylic acid.

Examples of the acid anhydride-containing monomer include maleic anhydride, itaconic anhydride, and acid anhydrides thereof.

Examples of the hydroxy group-containing monomers include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 6-hydroxyhexyl (meth)acrylate. , 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, (4-hydroxymethylcyclohexyl)methyl acrylate, N- Examples include methylol (meth)acrylamide, vinyl alcohol, allyl alcohol, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, and diethylene glycol monovinyl ether.

Examples of the amine group-containing monomer include aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl (meth)acrylate, and (meth)acryloylmorpholine. etc. can be mentioned.

Examples of the imide group-containing monomer include cyclohexylmaleimide, isopropylmaleimide, N-cyclohexylmaleimide, and itaconimide.

Examples of the epoxy group-containing monomer include glycidyl (meth)acrylate, methylglycidyl (meth)acrylate, and allyl glycidyl ether.

Examples of the ether group-containing monomer include 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, phenoxyethyl (meth)acrylate, and acrylate. Ilmorphorin, etc. can be mentioned.

The crosslinkable monomer may be included in 0 to 10 parts by weight or 0.05 to 10 parts by weight, preferably 1 to 8 parts by weight, based on 100 parts by weight of total monomers used in the production of the acrylic copolymer.

For example, when the crosslinkable monomer includes 2-hydroxyethyl (meth)acrylate, the crosslinkable monomer may be included in an amount of 0 to 10 parts by weight based on 100 parts by weight of the total monomers used in the production of the acrylic copolymer. there is.

Additionally, for example, when the crosslinkable monomer includes (meth)acrylic acid, the crosslinkable monomer may be included in an amount of 0 to 5 parts by weight based on 100 parts by weight of the total monomers used in the production of the acrylic copolymer.

Within the above range, the adhesive composition may have excellent adhesion and cohesion, and the adhesive durability of the cured product may be improved.

In addition, in addition to the above monomers, other polymerizable monomers known in the art may be further included in a range that does not reduce adhesion, for example, 10 parts by weight or less out of 100 parts by weight of the total monomers used in the production of the acrylic copolymer.

The method for producing the acrylic copolymer is not particularly limited, and may be produced using methods commonly used in the art such as bulk polymerization, solution polymerization, emulsion polymerization, suspension polymerization, or UV polymerization, preferably solution polymerization. It can be manufactured using a method or UV polymerization method. In addition, solvents commonly used during polymerization, polymerization initiators, chain transfer agents for molecular weight control, etc. may be further used.

In some embodiments, a polymerization initiator may be used to polymerize the acrylic monomer and/or crosslinkable monomer.

The polymerization initiator is, for example, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, 1-hydroxycyclohexyl. -1-phenylmethanone, hydroxydimethylacetophenone, dimethylaminoacetophenone, dimethoxy-2-phenylacetophenone, 3-methylacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2- Diethoxy-2-phenylacetophenone, 4-chronolocetophenone, 4,4-dimethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 4-hydroxycyclophenyl ketone , 1-hydroxycyclohexylphenylketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one, oligo[2-hydroxy-2-methyl-1 -(4-(1-methylvinyl)phenyl)propanone], 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)ketone, benzophenone, p-phenylbenzophenone, 4 ,4-diaminobenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, anthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 2-aminoanthra Quinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethylketal, diphenylketonebenzyl Dimethyl ketal, acetophenone dimethyl ketal, p-dimethylaminobenzoic acid ester, 2,4,6-trimethylbenzoyldiphenylphosphine oxide (TPO), fluorene, triphenylamine, carbazole, azobisisobutyronitrile (AIBN) ), etc. may be included. These can be used individually or in combination of two or more types.

In some embodiments, the polymerization initiator may be included in an amount of 0.01 to 3 parts by weight, preferably 0.01 to 1 part by weight, based on 100 parts by weight of the total weight of the acrylic monomer and/or crosslinkable monomer.

In some embodiments, the acrylic copolymer may have a weight average molecular weight (polystyrene conversion, Mw) of 50,000 to 2,000,000 as measured by gel permeation chromatography (GPC). Preferably, the weight average molecular weight may be 300,000 to 1,700,000. If the weight average molecular weight of the acrylic copolymer is less than 50,000, the adhesive durability may be reduced due to insufficient cohesion between the copolymers. If it exceeds 2,000,000, a large amount of diluting solvent may be required to ensure fairness during coating.

In exemplary embodiments, the adhesive composition may include a compound that includes at least one aromatic ring and has a refractive index of 1.55 or more. Preferably, the refractive index of the compound may be 1.55 or more, 1.56 or more, 1.57 or more, 1.58 or more, 1.59 or more, 1.60 or more, 1.61 or more, 1.62 or more, or 1.63 or more.

If the refractive index of the compound is less than 1.55, the refractive index of the adhesive sheet is lowered and the adhesive sheet cannot function as a refractive index relaxation layer between the sensing electrode and the optical member.

As used herein, “aromatic ring” is the structure of a benzene ring. The compound may include a structure in which at least one aromatic ring is substituted or unsubstituted, or is fused to another benzene ring, cycloalkyl group, or heterocycloalkyl group.

For example, the compound may reduce the elastic modulus and glass transition temperature (Tg) of the adhesive composition, while maintaining or increasing high refractive properties by containing at least one aromatic ring. In this case, there may be no need to form a separate high refractive index pattern layer to correct the difference in refractive index between the sensing electrode and the optical member (eg, polarizer) in the image display device. Accordingly, the process is simplified, process costs are reduced, and the thickness of the image display device can be reduced.

In some embodiments, the compound may include two or more aromatic rings and at least one hetero atom selected from N, S, and O. For example, the compound may include 2 to 6 aromatic rings and at least one O (oxygen).

According to exemplary embodiments, the compound may include a compound represented by Formula 1 below.

[Formula 1]

R ₁ -L-Ar ₁

In Formula 1, L is a direct bond, a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, an ether group, a sulfide group, an amide group, or a substituted or unsubstituted group containing 1 to 10 carbon atoms including an ether group, a sulfide group, or an amide group. is a hydrocarbon group, and R ₁ is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms; A substituted or unsubstituted hydrocarbon group having 1 to 10 carbon atoms, including an ether group, a sulfide group, or an amide group; A substituted or unsubstituted cycloalkyl group having 3 to 12 carbon atoms; A substituted or unsubstituted heteroaryl group having 4 to 12 carbon atoms; (meth)acrylate group; or -Ar ₂ , and Ar ₁ and Ar ₂ are each independently a substituted or unsubstituted aryl group having 6 to 14 carbon atoms or a C 4 to 12 aryl group substituted with at least one aromatic ring or fused with at least one aromatic ring. It is a heteroaryl group.

The “substitution” refers to a halogen atom, an alkyl group of C1-C6, an alkenyl group of C2-C6, an alkynyl group of C2-C6, an alkoxy group of C1-C6, a phenoxy group of C6-C12, a hydroxy group, a nitro group, and a cyano group. It may mean being replaced with at least one of.

The (meth)acrylate group may mean an acrylate group or a methacrylate group.

For example, Ar ₁ and Ar ₂ may each independently include two or more substituted or unsubstituted aromatic rings. The two or more aromatic rings are directly bonded; or fused together; It may be connected to a substituted or unsubstituted alkylene group, an ether group, a sulfide group, an amide group, or a substituted or unsubstituted hydrocarbon group having 1 to 10 carbon atoms, including an ether group, a sulfide group, or an amide group.

When the compound includes Ar ₁ or Ar ₁ and Ar ₂ as shown in Formula 1, for example, the elastic modulus and glass transition temperature of the adhesive composition may be sufficiently reduced. Accordingly, the adhesive properties and flexibility of the adhesive sheet formed from the adhesive composition can be secured. In addition, the above-mentioned elastic modulus and glass transition temperature can be reduced while maintaining or improving the refractive index of the adhesive composition.

The heteroaryl group may refer to a ring structure in which hetero atoms and carbon form a skeleton. The heteroatoms may include N, S, O, P, etc., and may be included in a heteroaryl group alone or in combination of two or more. The heteroaryl group may contain 1 to 3 heteroatoms of the same type. Alternatively, the heteroaryl group may each contain 1 to 3 heteroatoms of two or more types.

The compound represented by Formula 1 may include at least two aromatic rings, or may include at least four aromatic rings. For example, Ar ₁ and Ar ₂ may each independently be a substituted or unsubstituted naphthyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted carbazole group, or a substituted or unsubstituted phenoxyphenyl group. there is.

In Formula 1, L is a direct bond, a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, an ether group, a sulfide group, an amide group, or a substituted or unsubstituted carbon number of 1 including an ether group, a sulfide group, or an amide group. It may be from 10 to 10 hydrocarbon groups.

The hydrocarbon group may include, for example, an aliphatic hydrocarbon group and an aromatic hydrocarbon group. The hydrogen atom contained in the hydrocarbon group may be substituted with an alkyl group, halogen atom, alkoxy group, phenoxy group, hydroxy group, etc., and -CH ₂ - contained in the hydrocarbon group may be substituted with a hetero atom such as an oxygen atom, a sulfur atom, or a nitrogen atom. It may be substituted with an atom or -(CH ₂ O)m-. In this case, m may be 1 to 4.

For example, L is a methylene group (*-CH ₂ -*), a hexylene group (*-CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ -*), an ether group (*-O-*), * -O-CH ₂ CH ₂ -O-*, *-O-CH ₂ CH ₂ -*, *-CH ₂ CH ₂ -O-*, *-CH ₂ -O-CH ₂ -* or *-CH ₂ It may be -O-CH ₂ CH(OH)CH ₂ -O-CH ₂ -*. The “*” indicates the bonding point with R ₁ and Ar ₁ .

According to one embodiment, the compound may include at least one of the compounds represented by Formulas 2 to 10 below.

[Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

[Formula 6]

[Formula 7]

[Formula 8]

[Formula 9]

[Formula 10]

In some embodiments, the compound may be included in an amount of 0.1 to 20 parts by weight based on 100 parts by weight of the acrylic copolymer described above. Alternatively, the compound may be included in an amount of 5 to 10 parts by weight based on 100 parts by weight of the acrylic copolymer described above.

In this case, the elastic modulus and glass transition temperature of the pressure-sensitive adhesive composition can be sufficiently reduced to improve step absorption while preventing deterioration of mechanical stability and high-temperature reliability due to excessive addition of the above-mentioned compounds.

In some embodiments, the compound may include a compound having a molecular weight of 200 to 10,000 g/mol, 200 to 1,000 g/mol, or 200 to 500 g/mol. Accordingly, it is possible to sufficiently reduce the elastic modulus and glass transition temperature of the above-described adhesive composition while preventing a decrease in flexibility due to an excessively high molecular weight.

In some embodiments, the adhesive composition may use a photoinitiator and/or a heat curing agent to crosslink the acrylic copolymer.

The photoinitiator is, for example, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, 1-hydroxycyclohexyl- 1-phenylmethanone, hydroxydimethylacetophenone, dimethylaminoacetophenone, dimethoxy-2-phenylacetophenone, 3-methylacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-die Toxy-2-phenylacetophenone, 4-chronolocetophenone, 4,4-dimethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 4-hydroxycyclophenyl ketone, 1-Hydroxycyclohexylphenylketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one, oligo[2-hydroxy-2-methyl-1- (4-(1-methylvinyl)phenyl)propanone], 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)ketone, benzophenone, p-phenylbenzophenone, 4, 4-Diaminobenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, anthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 2-aminoanthraquinone , 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethylketal, diphenylketonebenzyldimethyl Ketal, acetophenone dimethyl ketal, p-dimethylaminobenzoic acid ester, 2,4,6-trimethylbenzoyldiphenylphosphine oxide (TPO), fluorene, triphenylamine, carbazole, azobisisobutyronitrile (AIBN) It may include etc. These can be used individually or in combination of two or more types.

In some embodiments, the photoinitiator may be included in an amount of 0.01 to 3 parts by weight, preferably 0.2 to 2 parts by weight, based on 100 parts by weight of the acrylic copolymer.

The heat curing agent is not particularly limited as long as it is a component that can strengthen the cohesion of the adhesive composition by appropriately crosslinking the acrylic copolymer, but isocyanate crosslinking agents, organometallic compounds, such as metal chelate crosslinking agents, etc. can be used. .

The isocyanate-based crosslinking agent is, for example, tolylene diisocyanate, xylene diisocyanate, hexamethylene diisocyanate, 2,4-diphenylmethane diisocyanate, 4,4-diphenylmethane diisocyanate, isophorone diisocyanate, tetra Examples include addition trimers such as methylxylene diisocyanate, naphthalene diisocyanate, and 2,4-toluene diisocyanate addition trimers, or isocyanurate trimers.

The heat curing agent is preferably included in an amount of 0.1 to 1 part by weight, more preferably 0.1 to 0.5 parts by weight, based on 100 parts by weight of the acrylic copolymer.

In some embodiments, the adhesive composition includes a crosslinking agent, a tackifying resin, an antioxidant, a corrosion inhibitor, and a leveling agent in order to adjust the adhesion, cohesion, viscosity, elastic modulus, glass transition temperature, antistatic properties, etc. required depending on the application. It may further contain additives such as additives, surface lubricants, anti-foaming agents, fillers, light stabilizers, reaction initiators, and solvents.

In some embodiments, the refractive index of the adhesive layer formed from the adhesive composition may be 1.50 or more. Alternatively, the refractive index of the adhesive layer formed from the adhesive composition may be 1.52 or more, 1.54 or more, 1.56 or more, 1.58 or more, or 1.60 or more.

In this case, a high refractive index can be secured while the adhesive layer has a low glass transition temperature and elastic modulus. Accordingly, in an image display device, the difference in refractive index between the sensing electrode and the optical member can be alleviated while a separate high refractive index pattern layer cannot be formed.

For example, the glass transition temperature of the adhesive composition may be -20°C or lower. Accordingly, an adhesive sheet can be formed while sufficiently realizing the adhesive properties of the adhesive composition.

<Adhesive sheet and image display device>

Below, an adhesive sheet and an image display device including an adhesive layer formed from the above-described adhesive composition will be described.

1 is a schematic cross-sectional view illustrating an adhesive sheet according to example embodiments.

Referring to FIG. 1, the adhesive sheet includes a base film 120 and an adhesive layer 110 formed on one surface of the base film 120. For example, the adhesive layer 110 may be formed by applying the above-described adhesive composition to one surface of the base film 120.

The base film 120 is not particularly limited, and a release film commonly used in adhesive sheets may be used. For example, the base film 120 may be made of polyester resin such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate; polyimide resin; Acrylic resin; Styrene-based resins such as polystyrene and acrylonitrile-styrene; polycarbonate resin; polylactic acid resin; polyurethane resin; polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymer; Vinyl resins such as polyvinyl chloride and polyvinylidene chloride; polyamide resin; Sulfone resin; polyether-etherketone-based resin; Allylate resin; Alternatively, it may be a release film formed from a mixture of the above resins.

The adhesive layer 110 may be formed by applying the adhesive composition of exemplary embodiments to one surface of the base film 120 and drying and/or curing it. For example, the adhesive layer 110 can be formed by applying the adhesive composition on the base film 120 using a coating method such as roll coating, gravure coating, reverse coating, spray coating, air knife coating, or die coater. .

For example, the adhesive layer 110 can be formed by drying the applied adhesive composition, photocuring it by irradiating light, or heat curing it by heating. The adhesive layer 110 can be formed by combining one or more of the drying, photocuring, or thermal curing methods.

In some embodiments, the base film 120 may be formed on the upper and lower surfaces of the adhesive layer 110, respectively. For example, the base film 120 formed on the lower surface of the adhesive layer 110 may be removed and the exposed surface of the adhesive layer 110 may be attached to the object. Afterwards, the base film 120 formed on the upper surface is removed and another object is attached to the exposed surface of the adhesive layer 110 to form a laminate (for example, an image display device).

In some embodiments, the refractive index of the adhesive layer 110 may be 1.50 or more. Alternatively, the refractive index of the adhesive layer 110 may be 1.52 or more, 1.54 or more, 1.56 or more, 1.58 or more, or 1.60 or more.

In this case, the adhesive layer 110 can secure a high refractive index while having a low glass transition temperature and elastic modulus. Accordingly, in an image display device, the difference in refractive index between the sensing electrode and the optical member can be alleviated while a separate high refractive index pattern layer cannot be formed.

Figure 2 is a schematic cross-sectional view for explaining an image display device according to example embodiments.

Referring to FIG. 2, the image display device includes a display panel 130, a touch sensor layer 140 disposed on the display panel, a polarizer 150 disposed on the touch sensor layer 140, and the touch sensor layer ( 140) and the polarizing plate 150 and may include an adhesive layer 110 formed of the adhesive composition according to the above-described embodiments.

In this case, the adhesive layer 110, which has a high refractive index and excellent adhesive properties, is disposed between the touch sensor layer 140 and the polarizer 150 to alleviate the difference in refractive index between the two layers. Accordingly, the refractive index difference can be alleviated only with the adhesive layer 110 without forming a separate refractive index alleviating layer. Accordingly, the thickness of the image display device can be reduced, the process can be simplified, and the process cost can be reduced.

The display panel 130 may be, for example, a liquid crystal display panel (LCD) or an organic light emitting display panel (OLED).

For example, the polarizing plate 150 may include a polarizer and a protective film bonded to at least one surface of the polarizer. For example, the adhesive layer may be formed by bonding an adhesive sheet to a protective film, or may be coated directly on the protective film.

The protective film included in the polarizing plate 150 is not particularly limited as long as it has excellent transparency, mechanical strength, thermal stability, moisture shielding, isotropy, etc. Specifically, the protective film includes polyester-based films such as polyethylene terephthalate, polyethylene isophthalate, and polybutylene terephthalate; Cellulose-based films such as diacetylcellulose and triacetylcellulose; polycarbonate-based film; Acrylic films such as polymethyl (meth)acrylate and polyethyl (meth)acrylate; Styrene-based films such as polystyrene and acrylonitrile-styrene copolymer; polyolefin-based film; Vinyl chloride-based film; Polyamide-based films such as nylon and aromatic polyamide; imide-based film; Sulfone-based film; polyether ketone-based film; Sulfated polyphenylene-based film; Vinyl alcohol-based film; Vinylidene chloride-based film; Vinyl butyral-based film; Allylate-based film; polyoxymethylene-based film; Urethane-based film; Epoxy-based film; Silicone-based films, etc. can be mentioned.

The polarizer may be a polarizer known in the art and, for example, may be manufactured through processes such as swelling, dyeing, cross-linking, stretching, washing, and drying of a polyvinyl alcohol-based film.

In some embodiments, the touch sensor layer 140 includes a base layer 142 and touch sensing electrodes 144 arranged on the base layer 142, and the adhesive layer 110 includes a touch sensing electrode 144. ) can be in direct contact with the polarizer 150 by filling the space between them. In this case, the adhesion between the touch sensor layer 140 and the polarizing plate 150 can be improved by removing the step caused by the patterning of the touch sensing electrodes 144. Accordingly, the mechanical stability of the image display device can be improved.

For example, the image display device may further include other configurations known in the art in addition to the above configurations. For example, retardation film, hard coating film, protective film, window film, touch panel, etc. may be further included.

As shown in FIG. 2, the image display device may further include, for example, a cover window 170 on the polarizer 150. The polarizer 150 and the cover window 170 may be bonded through the upper adhesive layer 160.

The cover window 170 may be used without limitation as long as it is employed in the art to protect the internal structure of an image display device, and may be, for example, glass.

For example, the display panel 130, the touch sensor layer 140, and the optical members can be stacked using the adhesive layer 110 formed from the adhesive composition described above. In this case, the adhesive layer 110 itself alleviates the difference in refractive index between the display panel 130 and the optical member (e.g., polarizer 150), so there is no need to form a separate high-refractive pattern layer in the image display device. You can. Accordingly, the thickness can be reduced while the luminance of the image display device is improved, and fairness can be improved.

Hereinafter, experimental examples including specific examples and comparative examples are presented to aid understanding of the present invention, but this is only illustrative of the present invention and does not limit the scope of the appended claims, and does not limit the scope and technology of the present invention. It is obvious to those skilled in the art that various changes and modifications to the embodiments are possible within the scope of the spirit, and it is natural that such changes and modifications fall within the scope of the appended patent claims.

Example 1

In a 1 L reactor equipped with a cooling device to reflux nitrogen gas and facilitate temperature control, 70 parts by weight of biphenylmethyl acrylate, 20 parts by weight of phenoxybenzyl acrylate, 9 parts by weight of 4-hydroxybutylacrylate, and 1 part by weight of acrylic acid. After adding the monomer mixture consisting of parts by weight, 300 parts by weight of methyl ethyl ketone was added as a solvent. Afterwards, nitrogen gas was introduced for 1 hour to remove oxygen, and the temperature was maintained at 70°C. After stirring the monomer mixture uniformly, 0.07 parts by weight of azobisisobutyronitrile (AIBN) was added as a reaction initiator and reacted for 8 hours to prepare an acrylic copolymer with a weight average molecular weight of 1,120,000.

An adhesive composition was prepared by adding 5 parts by weight of a compound represented by Formula 2 of the present specification to the prepared acrylic copolymer, and further adding 0.5 parts by weight of an isocyanate-based crosslinking agent (AK75, Aekyung Chemical Co., Ltd.). At this time, the molecular weight of the added compound is 270.3 g/mol and the refractive index is 1.63.

The adhesive composition was coated on a 75 ㎛ thick polyethylene terephthalate (PET) film that had been treated with a release coating solution using a bar coater. Afterwards, it was dried at 100°C for 5 minutes and cured at room temperature for 7 days to prepare an adhesive sheet with an adhesive layer thickness of 25 ㎛.

Example 2

An adhesive composition and an adhesive sheet were prepared in the same manner as in Example 1, except that 10 parts by weight of the compound represented by Formula 2 was added.

Example 3

An adhesive composition and an adhesive sheet were prepared in the same manner as in Example 1, except that 5 parts by weight of the compound represented by Formula 3 was added instead of the compound represented by Formula 2.

At this time, the molecular weight of the added compound is 314.4 g/mol and the refractive index is 1.61.

Example 4

An adhesive composition and an adhesive sheet were prepared in the same manner as in Example 1, except that 5 parts by weight of the compound represented by Formula 4 was added instead of the compound represented by Formula 2.

At this time, the molecular weight of the added compound is 366.5 g/mol and the refractive index is 1.60.

Example 5

An adhesive composition and an adhesive sheet were prepared in the same manner as in Example 1, except that 5 parts by weight of the compound represented by Formula 5 was added instead of the compound represented by Formula 2.

At this time, the molecular weight of the added compound is 350.5 g/mol and the refractive index is 1.62.

Example 6

An adhesive composition and an adhesive sheet were prepared in the same manner as in Example 1, except that phenoxyethyl acrylate was used instead of phenoxybenzyl acrylate, and 5 parts by weight of the compound represented by Formula 6 was added instead of the compound represented by Formula 2. was manufactured.

At this time, the weight average molecular weight of the prepared acrylic copolymer was 1,350,000 g/mol, the molecular weight of the added compound was 426.5 g/mol, and the refractive index was 1.59.

Example 7

An adhesive composition and an adhesive sheet were prepared in the same manner as in Example 1, except that phenoxyethyl acrylate was used instead of phenoxybenzyl acrylate, and 5 parts by weight of the compound represented by Formula 7 was added instead of the compound represented by Formula 2. was manufactured.

At this time, the weight average molecular weight of the prepared acrylic copolymer was 1,350,000 g/mol, the molecular weight of the added compound was 416.6 g/mol, and the refractive index was 1.58.

Example 8

An adhesive composition and an adhesive sheet were prepared in the same manner as in Example 1, except that 5 parts by weight of the compound represented by Formula 8 was added instead of the compound represented by Formula 2.

At this time, the molecular weight of the added compound is 238.3 g/mol and the refractive index is 1.60.

Example 9

An adhesive composition and an adhesive sheet were prepared in the same manner as in Example 1, except that 5 parts by weight of the compound represented by Formula 9 was added instead of the compound represented by Formula 2.

At this time, the molecular weight of the added compound is 254.3 g/mol and the refractive index is 1.61.

Example 10

An adhesive composition and an adhesive sheet were prepared in the same manner as in Example 1, except that 5 parts by weight of the compound represented by Formula 10 was added instead of the compound represented by Formula 2.

At this time, the molecular weight of the added compound is 268.3 g/mol and the refractive index is 1.61.

Example 11

An adhesive composition and an adhesive sheet were prepared in the same manner as in Example 1, except that 0.05 parts by weight of the compound represented by Formula 2 was added.

Example 12

An adhesive composition and an adhesive sheet were prepared in the same manner as Example 1, except that 21 parts by weight of the compound represented by Formula 2 was added.

Comparative Example 1

An adhesive composition and an adhesive sheet were prepared in the same manner as in Example 1, except that phenoxyethyl acrylate was used instead of phenoxybenzyl acrylate and the compound represented by Formula 2 was not added.

Comparative Example 2

An adhesive composition and an adhesive sheet were prepared in the same manner as in Example 1, except that 5 parts by weight of di(2-ethylhexyl) adipate was added instead of the compound represented by Formula 2.

The molecular weight of di(2-ethylhexyl)adipate is 370.0 g/mol and the refractive index is 1.446.

Tables 1 and 2 below show the formulations of the adhesive compositions of Examples 1 to 10, Examples 11, 12, and Comparative Examples 1 to 3, respectively.

Unit: parts by weight Example One 2 3 4 5 6 7 8 9 10 Acrylic type
copolymer A1 70 70 70 70 70 70 70 70 70 70 A2 20 20 20 20 20 20 20 20 A3 20 20 B1 9 9 9 9 9 9 9 9 9 9 B2 One One One One One One One One One One compound C1 5 10 C2 5 C3 5 C4 5 C5 5 C6 5 C7 5 C8 5 C9 5 thermosetting agent D1 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 A1: Biphenylmethyl acrylate (homopolymer refractive index: 1.636, Tg: 20℃) (Miwon Specialty Chemical Co., Ltd.)
A2: Phenoxybenzyl acrylate (homopolymer refractive index: 1.597, Tg: 22℃) (Miwon Specialty Chemicals)
A3: Phenoxyethyl acrylate (homopolymer refractive index: 1.550, Tg: -1℃)
B1: 4-hydroxybutylacrylate (homopolymer refractive index: 1.493, Tg: -32℃) (Gongyoungsa)
B2: Acrylic acid
C1: Compound represented by Formula 2 (molecular weight: 270.3 g/mol, refractive index: 1.63)
C2: Compound represented by Formula 3 (molecular weight: 314.4 g/mol, refractive index: 1.61)
C3: Compound represented by formula 4 (molecular weight: 366.5/mol, refractive index: 1.60)
C4: Compound represented by Formula 5 (molecular weight: 350.5 g/mol, refractive index: 1.62)
C5: Compound represented by Formula 6 (molecular weight: 426.5/mol, refractive index: 1.59)
C6: Compound represented by Formula 7 (molecular weight: 416.6 g/mol, refractive index: 1.58)
C7: Compound represented by Formula 8 (molecular weight: 238.3 g/mol, refractive index: 1.60) (Miwon Specialty Chemicals)
C8: Compound represented by Formula 9 (molecular weight: 254.3 g/mol, refractive index: 1.57) (Miwon Special Chemicals)
C9: Compound represented by formula 10 (molecular weight: 268.3 g/mol, refractive index: 1.58) (Miwon Special Chemicals)
D1: Isocyanate-based crosslinking agent (AK75) (Aekyung Chemical)

Unit: parts by weight Example Comparative example 11 12 One 2 Acrylic type
copolymer A1 70 70 70 70 A2 20 20 20 A3 20 B1 9 9 9 9 B2 One One One One compound C1 0.05 21 C10 5 heat hardener D1 0.5 0.5 0.5 0.5 A1 to A3, B1, B2, C1 and D1 are as listed in Table 1
C10: di(2-ethylhexyl) adipate (molecular weight: 370.0 g/mol, refractive index: 1.446)

Experiment example

(1) Transparency evaluation

In the adhesive sheets according to the above-mentioned examples and comparative examples, the adhesive layer was peeled from the PET film and bonded to a slide glass (manufactured by Matsunami Glass Kogyo, model number: S1111).

The haze value (%) was measured in accordance with JISK-7136 at 25°C using a “Reflection/Transmittance Meter HR-100 Type” manufactured by Murakami Shiki Saigijutsu Kenkyu Shosha Co., Ltd.

The haze value of the adhesive layer was evaluated by subtracting the haze value (0.2%) of the glass slide from the measured value. The evaluation results are shown in Table 3 below.

○: Haze value is less than 2%

Χ: Haze value of 2% or more

(2) Refractive index evaluation

The adhesive layers according to the above-mentioned examples and comparative examples were irradiated with sodium D-rays in an atmosphere of 25° C. and the refractive index was measured with an Abbe refractometer (DMM4, manufactured by ATAGO). The measurement results are shown in Table 3 below.

◎: Refractive index is 1.60 or more.

○: Refractive index is 1.58 or more and less than 1.60.

△: Refractive index is 1.56 or more and less than 1.58.

Χ: Refractive index is less than 1.56.

(3) Evaluation of step absorbency

The adhesive sheets according to the above-described examples and comparative examples were bonded to glass with a printing step of 3 μm. At this time, the size of the glass on the inside is 5 cmХ10 cmХ0.7 cm.

After that, it was left to stand at 85°C, 40°C, and room temperature (23°C) for 24 hours, respectively, and the lifting state of the surface to which the adhesive layer was bonded was visually observed and evaluated. The evaluation results are shown in Table 3 below.

◎: No lifting at 85°C.

○: No lifting at 40°C.

△: No heaving at room temperature.

Χ: Excited at room temperature.

(4) High temperature reliability evaluation

) 및 습열 환경(60 ℃, 90 %) 하에서 500시간 방치한 후, 육안으로 기포 및/또는 박리 발생 여부를 관찰하여 고온 신뢰성을 평가하였다. 평가 결과를 하기 표 3에 나타내었다.A laminate was manufactured by plying the adhesive sheets according to the above-described examples and comparative examples between a polarizing plate and glass. The laminate was heated at a high temperature (80

) and left in a moist heat environment (60°C, 90%) for 500 hours, the high-temperature reliability was evaluated by visually observing whether bubbles and/or peeling occurred. The evaluation results are shown in Table 3 below.

ⓞ: No bubbles or peeling.

○: Less than 5 bubbles or peeling.

△: 5 to 10 bubbles or peeling.

Χ: 10 or more bubbles or peeling.

division Example Comparative example One 2 3 4 5 6 7 8 9 10 11 12 One 2 transparency ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ refractive index ⓞ ⓞ ⓞ ⓞ ⓞ ○ ⓞ ⓞ ⓞ ⓞ ○ ⓞ ○ △ Step absorbency ○ ⓞ ○ ○ ○ ⓞ ⓞ ⓞ ⓞ ⓞ △ ⓞ X ○ High temperature reliability ⓞ ○ ⓞ ⓞ ⓞ ○ △ ○ ○ ○ ○ △ ○ ⓞ

Referring to Table 3 above, the adhesive layers and adhesive sheets of the Examples manufactured with an adhesive composition prepared by adding a compound with a refractive index of 1.55 or more and containing at least one aromatic ring have excellent transparency, refractive index, step absorption, and high temperature reliability. This was implemented.

Accordingly, it is possible to implement an adhesive composition, adhesive layer, and adhesive sheet that have both excellent adhesive properties and high refractive properties.

However, the adhesive layer and adhesive sheet according to Comparative Example 1 had reduced step absorption and reduced adhesion. The adhesive layer and adhesive sheet according to Comparative Example 2 have a significantly reduced refractive index and cannot function as a refractive index relaxation layer between the sensing electrode and the optical member.

110: Adhesive layer 120: Base film
130: Display panel 140: Touch sensor layer
142: base layer 144: touch sensing electrode
150: Polarizer 160: Upper adhesive layer
170: cover window

Claims (13)

Acrylic copolymer; and
An adhesive composition comprising a compound containing at least one aromatic ring and having a refractive index of 1.55 or more,
The adhesive layer formed from the adhesive composition has a refractive index of 1.50 or more. The pressure-sensitive adhesive composition according to claim 1, wherein the acrylic copolymer includes a repeating unit derived from an acrylic monomer, and the homopolymer of the acrylic monomer has a refractive index of 1.50 or more. The method of claim 2, wherein the acrylic monomer is pentabromophenyl (meth)acrylate, 2-(naphthalen-2-yloxy)ethyl (meth)acrylate, 2-(naphthalen-2-ylthio)ethyl (meth) Acrylate, 1-ethoxylated phenol (meth)acrylate, biphenylmethyl (meth)acrylate, phenylphenol ethoxy (meth)acrylate, phenoxybenzyl (meth)acrylate, phenoxyethyl (meth) An adhesive composition comprising at least one of acrylate and 1-pyrenemethyl (meth)acrylate. The adhesive composition of claim 1, wherein the compound includes a compound having a molecular weight of 150 to 10,000 g/mol. The adhesive composition according to claim 1, wherein the compound includes a compound represented by the following formula (1):
[Formula 1]
R ₁ -L-Ar ₁
(In Formula 1, L is a direct bond, a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, an ether group, a sulfide group, an amide group, or a substituted or unsubstituted group containing 1 to 10 carbon atoms including an ether group, a sulfide group, or an amide group. It is a hydrocarbon group of 10,
R ₁ is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms; A substituted or unsubstituted hydrocarbon group having 1 to 10 carbon atoms, including an ether group, a sulfide group, or an amide group; A substituted or unsubstituted cycloalkyl group having 3 to 12 carbon atoms; A substituted or unsubstituted heteroaryl group having 4 to 12 carbon atoms; (meth)acrylate group; or -Ar ₂ ,
Ar ₁ and Ar ₂ are each independently a substituted or unsubstituted aryl group having 6 to 14 carbon atoms or a heteroaryl group having 4 to 12 carbon atoms substituted with at least one aromatic ring or fused with at least one aromatic ring. The method of claim 5, wherein Ar ₁ and Ar ₂ each independently include two or more substituted or unsubstituted aromatic rings,
Two or more aromatic rings are directly bonded; fused together; An adhesive composition linked to a substituted or unsubstituted hydrocarbon group having 1 to 10 carbon atoms, including a substituted or unsubstituted alkylene group, an ether group, a sulfide group, an amide group or an ether group, a sulfide group or an amide group. The method of claim 5, wherein Ar ₁ and Ar ₂ are each independently a substituted or unsubstituted naphthyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted carbazole group, or a substituted or unsubstituted phenoxyphenyl group. , adhesive composition. The adhesive composition of claim 1, wherein the compound includes at least one of the compounds represented by the following formulas 2 to 10:
[Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

[Formula 6]

[Formula 7]

[Formula 8]

[Formula 9]

[Formula 10]
. The adhesive composition according to claim 1, wherein the compound is included in an amount of 0.1 to 20 parts by weight based on 100 parts by weight of the acrylic copolymer. The adhesive composition of claim 1, further comprising at least one of a photoinitiator and a heat curing agent. An adhesive sheet comprising an adhesive layer formed from the adhesive composition of claim 1. display panel;
a touch sensor layer disposed on the display panel;
A polarizing plate disposed on the touch sensor layer; and
An image display device comprising an adhesive layer formed between the touch sensor layer and the polarizing plate and made of the adhesive composition of claim 1. The method of claim 12, wherein the touch sensor layer includes a base layer and touch sensing electrodes arranged on the base layer,
The adhesive layer fills the space between the touch sensing electrodes and is in direct contact with the polarizing plate.