KR20170050277A - Adhesive composition and polarizing plate comprising adhesive layer formed by using the same - Google Patents

Abstract

The present invention relates to an adhesive composition comprising a compound represented by chemical formula 1, (X1)_n-Ti-(-O-L1-NH-L2-NH-X2)_m, and a polarizing plate comprising an adhesive layer formed by using the same. The adhesive composition according to embodiments of the present application is easy to form a covalent bond with a polarizer, and thus an excellent adhesive force can be secured.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polarizing plate comprising an adhesive composition and an adhesive layer formed using the adhesive composition.

The present invention relates to an adhesive composition and a polarizing plate comprising an adhesive layer formed using the adhesive composition.

The polarizing plate has been used as a structure in which a protective film is laminated on one or both sides of a polarizer made of polyvinyl alcohol (PVA) resin dyed with a dichroic dye or iodine. Conventionally, a triacetyl cellulose (TAC) film has been mainly used as a polarizer protective film. However, such a TAC film has a problem that it is easily deformed in a high temperature and high humidity environment. Recently, protective films of various materials capable of replacing TAC films have been developed. For example, protective films such as polyethylene terephthalate (PET), cycloolefin polymer (COP) Or a mixture thereof.

At this time, as an adhesive used for attaching the polarizer and the protective film, an aqueous adhesive mainly composed of an aqueous solution of a polyvinyl alcohol resin is used. However, in the case of the water-based adhesive, when an acrylic film or a COP film other than TAC is used as a protective film, the adhesive strength is weak, so that the use thereof is limited depending on the film material. In addition, in the case of the water-based adhesive, in addition to the problem of defective adhesive force depending on the material, when the material of the protective film applied to both surfaces of the PVA element is different, a problem of curling of the polarizer due to the drying process of the water- Problems such as lowering of physical properties occur. Furthermore, in the case of using the water-based adhesive, a drying process is indispensable. In such a drying process, a difference in moisture permeability, thermal expansion, As an alternative to the above-mentioned problems, a method of using a non-aqueous adhesive instead of an aqueous adhesive has been proposed.

Until now, the non-aqueous adhesive for a polarizing plate can be divided into a radical-curing adhesive and a cation-curing adhesive according to the curing method. Cation-curable adhesives have the advantage of having excellent adhesion to films of various materials, but they have many disadvantages in the manufacturing process due to the slow curing rate and low curing degree. In order to solve the problems of the cation-curable adhesive, a radical-curable adhesive containing an acrylamide-based compound as a main component has been proposed.

Among the UV curable adhesives, the radical curing type adhesive is very vulnerable to moisture because the adhesion with the polarizer is mainly composed of hydrogen bonding. Therefore, it is difficult to secure stable physical properties because there are cases where the kind of the base material is changed or the adhesive force is different depending on the moisture content of the polarizer, humidity change, and the like.

The present application provides a polarizer comprising an adhesive composition comprising a metal-containing compound and an adhesive layer formed using the adhesive composition.

One embodiment of the present application provides an adhesive composition comprising a compound of formula (1).

 [Chemical Formula 1]

In formula (1)

X1 is hydrogen, hydroxy, substituted or unsubstituted alkoxy, or substituted or unsubstituted aryloxy,

이며, X2 is hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, or

Lt;

L1 to L3 are the same or different and each independently represents a substituted or unsubstituted alkylene, a substituted or unsubstituted arylene, a substituted or unsubstituted alkylarylene, or a substituted or unsubstituted arylalkylene,

R is hydrogen or substituted or unsubstituted alkyl,

n is an integer of 0 to 3, m is an integer of 1 to 4, and n + m is 4.

According to another embodiment of the present application, the formula (1) may be represented by the following formula (3) or (4).

(3)

[Chemical Formula 4]

In the above formulas (3) and (4), the substituent is as defined in formula (1).

According to another embodiment of the present application, the adhesive composition further comprises a polymerizable compound and a radical initiator.

According to another embodiment of the present application, the adhesive composition further comprises an epoxy compound.

According to another embodiment of the present application, the adhesive composition further comprises at least one of an acid or photoacid generator.

Another embodiment of the present application is a polarizer comprising: a polarizer; An adhesive layer formed on at least one surface of the polarizer; And a polarizer protective film formed on the adhesive layer, wherein the adhesive layer is formed using an adhesive composition according to the above-described embodiments.

The adhesive composition according to the embodiments of the present application includes the compound of formula (1) including titanium, so that it is easy to form a covalent bond with the polarizer, thereby securing an excellent adhesive force and increasing the bonding force between the adhesives. In general, the addition of a monomer that helps increase the adhesive strength causes a decrease in the glass transition temperature, but when the compound of the above formula (1) is added, the glass transition temperature rises and an adhesive layer having excellent durability can be provided .

Fig. 1 shows the confirmation data of the synthesis of the compound of the formula 1-2.

One embodiment of the present application provides an adhesive composition comprising a compound of formula (I) as described above.

As used herein, "substituted or unsubstituted" means substituted or unsubstituted with alkyl, aryl, hydroxy, alkoxy or aryloxy.

In the present specification, alkyl includes straight chain or branched chain alkyl, for example, alkyl having 1 to 20 carbon atoms, specifically having 1 to 6 carbon atoms, such as methyl, ethyl, propyl, and the like.

In the present specification, alkoxy includes linear or branched alkoxy, and includes, for example, alkoxy having 1 to 20 carbon atoms, specifically 1 to 6 carbon atoms, such as methoxy, ethoxy, propoxy, and the like.

In the present specification, aryl includes monocyclic or polycyclic aryl, for example, aryl having 6 to 20 carbon atoms, specifically 6 to 12 carbon atoms such as phenyl, biphenyl, naphthyl, anthryl and the like.

In the present specification, aryloxy is an oxy group having a monocyclic or polycyclic aryl, for example, an aryl group having 6 to 20 carbon atoms, specifically 6 to 12 carbon atoms such as phenyl, biphenyl, naphthyl, anthryl and the like Lt; / RTI >

In the present specification, alkylene includes straight chain or branched alkylene, for example, alkylene having 1 to 20 carbon atoms, specifically 1 to 6 carbon atoms, such as methylene, ethylene, propylene and the like.

In the present specification, the arylene includes monocyclic or polycyclic arylene, and includes, for example, arylene having 6 to 20 carbon atoms, specifically 6 to 12 carbon atoms such as phenylene, biphenylene, naphthylene, anthrylene and the like have.

In the present specification, the alkylarylene includes a monocyclic or polycyclic arylene substituted by a straight chain or branched alkyl, and includes, for example, an alkylene group having 6 to 20 carbon atoms substituted with alkyl having 1 to 20 carbon atoms, specifically 1 to 6 carbon atoms, Specifically, there is arylene having 6 to 12 carbon atoms.

In the present specification, the arylalkylene includes a linear or branched alkylene substituted with a monocyclic or polycyclic aryl, and includes, for example, an alkylene group having 1 to 20 carbon atoms substituted with aryl having 6 to 20 carbon atoms, specifically 6 to 12 carbon atoms, And specifically includes alkylene having 1 to 6 carbon atoms.

According to another embodiment of the present application, the formula (1) may be represented by the following formula (3) or (4).

(3)

[Chemical Formula 4]

In the above formulas (3) and (4), the substituent is as defined in formula (1).

According to another embodiment of the present application, X1 is alkoxy.

According to another embodiment of the present application, L1 and L2 are the same or different and each independently alkylene, such as ethylene.

According to another embodiment of the present application, L3 is alkylene, such as ethylene.

According to another embodiment of the present application, R is hydrogen or methyl.

According to another embodiment of the present application, m is 3.

According to another embodiment of the present application, the compound of formula 1 may be selected from the following structural formulas.

[Formula 1-1] [Formula 1-2]

Formula 1-1 is KR44 (Titanium IV 2-propanolato, tris (3,6-diaza) hexanolato) from Kenrich Petrochemicals.

Formula 1-2 may be prepared from Formula 1-1 (KR44, Kenrich Petrochemicals). Concretely, Formula 1-1 and 2-isocyanatoethyl acrylate (Karenz AOI, Showa Denko) are prepared at a molar ratio of 1: 6.1. The molar ratio can be from 1: 4 to 1: 6.1, preferably 1: 6.1. Add THF (tetrahydrol furam) to a round bottom flask at a ratio of KR44 by weight, and dissolve KR44. The 2-isocyanatoethyl acrylate is slowly added dropwise thereto. At this time, the temperature can be maintained at room temperature by using an ice water bath. After stirring for 24 hours, the reaction was terminated using IR. The 1 H NMR spectrum of the compound is shown in FIG. The synthesized material may be referred to herein as KR44-acrylate.

The compound of Formula 1 has a structure in which an ester group containing two amines in the titanium is chelated. When compared with a compound not containing an amine group, for example, a titanium compound having a tetraalkoxy group, the adhesion to PVA polarizers can be greatly improved. Specifically, the two amines in the compound of formula (1) can act as a binding aid by pulling the -OH of the PVA polarizer physically close to each other as shown in FIG. 1, The adhesive strength can be improved.

[Figure 1]

[Figure 2]

As a result of the calculation chemical analysis, the pKa of each of the two amines of the compound of the formula (1-1) is as shown in the following table, so that it can play a role of pulling the -OH group of the PVA polarizer and the compound of the formula It can help to gather around the -OH of the PVA polarizer. The computational chemical analysis is based on quantum chemistry (DFT) calculations such as binding energy of the substrate and adhesive, and the chemical reaction is calculated by the COSMOtherm program, which calculates thermodynamic properties based on quantum chemistry for calculating pKa. Was used.

pKa pKa1 8.7 pKa2 8.8

In addition, as a result of calculation chemical analysis, the reaction energy with the polarizer of formula 1-1 is 1.54 kcal / mol, which is not a spontaneous reaction, but can easily react with the polarizer with the help of heat energy or catalyst. Herein, the role of the amine is analyzed by collecting the -OH of the PVA-based polarizer and making the reaction more likely to occur. Specifically, physical bonding by an amine having a high pKa, that is, hydrogen bonding with -OH of a PVA polarizer is formed, and bonding due to the proximity of -OH and Ti-OC of the PVA polarizer Is formed.

In addition, since a general tetraalkoxy titanium compound does not contain a photo-curable functional group, bonding force between adhesives is weak, or unreacted Ti material after curing may affect durability. However, in the case of the formula (4), since the photo-curable functional group is contained, the bonding force between the adhesives is excellent and the amount of the unreacted material remains or remains unaffected or has little or no effect on durability.

According to one embodiment of the present application, at least one of the compounds of the compound of Formula 1 may be used in an amount of 1 to 50 parts by weight based on 100 parts by weight of the adhesive composition. Within this range, there is an advantage that the adhesive strength to the polarizer and the glass transition temperature increase.

According to another embodiment of the present application, the adhesive composition further comprises a polymerizable compound and a radical initiator.

The polymerizable compound is a component capable of improving the adhesive force of the adhesive.

The content of the polymerizable compound may be about 5 to 95 parts by weight, preferably about 7 to 93 parts by weight, and more preferably about 9 to 91 parts by weight, based on 100 parts by weight of the total adhesive composition. When such a content is included, it is possible to realize excellent adhesive force.

The radical polymerizable monomer may be used without limitation as long as it is a compound having a radical reactive functional group, and examples thereof include (meth) acrylates having at least one (meth) acryloyl group in the molecule, acrylates , (Meth) acrylamides, (meth) acrylamides, maleimides, (meth) acrylic acid, maleic acid, itaconic acid, (meth) acrylaldehyde, - pyrrolidone, triallyl isocyanurate and the like can be used.

Specific examples of the (meth) acrylates having one (meth) acryloyl group in the molecule include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl Acrylates such as butyl (meth) acrylate, isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, isooctyl Stearyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxyphenyl

Acrylate, isobornyl (meth) acrylate, 1,4-cyclohexanedimethylol (meth) acrylate, 4-hydroxybutyl (meth) acrylate, cyclohexyl (Meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (Meth) acrylate of a phenol alkylene oxide adduct, a (meth) acrylate of a p-cumylphenol alkylene oxide adduct, a (meth) acrylate of an o-phenylphenol alkylene oxide adduct, a nonylphenol alkylene oxide adduct (Meth) acrylate of an alkylene oxide adduct of 2-methoxyethyl (meth) acrylate, ethoxyethoxyethyl (meth) acrylate and 2-ethylhexyl alcohol of water, Mono (meth) acrylate of mono (meth) acrylate, propylene glycol mono (meth) acrylate, pentanediol mono (meth) acrylate, hexanediol mono (meth) acrylate, diethylene glycol, mono Mono (meth) acrylate of dipentaerythritol, mono (meth) acrylate of tetraethylene glycol, mono (meth) acrylate of polyethylene glycol, mono (meth) Hydroxypropyl (meth) acrylate, propyleneglycol mono (meth) acrylate, propyleneglycol mono (meth) acrylate, 2-hydroxy- (Meth) acrylate, 2-ethyl-2-methyl-1,3-dioxolan-4-yl) methyl (meth) acrylate, (2-isobutyl- -1,3-dioxane (Meth) acrylate, glycidyl (meth) acrylate, 3, 4-dioxaspiro [4,5] decan- (Meth) acrylate, allyl (meth) acrylate, N (meth) acryloyloxymethyl isocyanate, 2- (meth) acryloyloxyethylhexahydrophthalimide, N- (meth) acryloyloxyethyltetrahydrophthalimide, 2- (meth) acryloyloxyethylhexahydrophthalic acid, 2- Acryloyloxyethyl succinic acid, ω-carboxy-polycaprolactone mono (meth) acrylate, 2- (meth) acryloyloxyethyl acid phosphate, polyethylene glycol-o-phenylphenyl ether acrylate and the like have.

Specific examples of the (meth) acrylamides include (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, Amide, N- (3-N, N-dimethylaminopropyl) (meth) acrylamide, N- (butoxymethyl) acrylamide, N-methyl- Bis (meth) acrylamide, N, N-diallyl (meth) acrylamide and the like.

Specific examples of the maleimide include N-methylmaleimide, N-hydroxyethylmaleimide, N-hydroxyethyl citraconimide, N-hydroxyethyl citraconimide and isophorone diisocyanate urethane acrylate And the like.

Specific examples of the (meth) acrylates having two (meth) acryloyl groups in the molecule include 1,3-butanediol di (meth) acrylate, 1,6-hexane diol (meth) Butanediol di (meth) acrylate, 2-methacryloyloxyethyl acrylate, ethylenebis (meth) acrylate, 2-methacryloyloxyethyl acrylate, Acrylate, diethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, neopentyl glycol di Acrylate, polyethylene glycol di (meth) acrylate, polyethylene glycol (di) (meth) acrylate, polyethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, cyclohexanedimethanol di Polyethylene glue (400) di (meth) acrylate, polyethylene glycol (600) di (meth) acrylate, glycerin di (meth) acrylate, 2- Methyl (meth) acrylate (kayard R604), dimethylol tricyclo < RTI ID = 0.0 > (Meth) acrylate, and the like.

Specific examples of the (meth) acrylates having three (meth) acryloyl groups in the molecule include propoxylate (6) trimethylolpropane tri (meth) acrylate, trimethylolpropane tri (meth) (3) a polyfunctional monomer such as trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tri (meth) acrylate, trimethylpropane tri (meth) acrylate, tri (2-hydroxyethyl) isocyanurate triacrylate, (2-hydroxyethyl) isocyanate, pentaerythritol triacrylate, ethoxylate trimethylolpropane tri (meth) acrylate, and proxylate trimethylolpropane tri (meth) acrylate.

Specific examples of the (meth) acrylates having 4 or 5 (meth) acryloyl groups in the molecule include pentaerythritol tetra (meth) acrylate, ditrimethylol propranetetra (meth) acrylate, dipentaerythritol penta (Meth) acrylate, epoxylated pentaerythritol tetra (meth) acrylate, and pentaacrylate ester.

Specific examples of the (meth) acrylates having six (meth) acryloyl groups in the molecule include dipentaerythritol hexa (meth) acrylate.

As an example of the polymerizable compound, a radically polymerizable compound containing at least two hydroxy groups in the molecule may be used. Such a compound has at least two hydroxyl groups in the molecule, thereby achieving excellent adhesion by hydrogen bonding with the polarizer, increasing the hydroxyl value of the adhesive composition, and also having at least one radically polymerizable group, For example, if radical polymerization is possible by having a carbon-carbon unsaturated double bond, it can be used without any particular limitation. The radically polymerizable compound containing at least two hydroxy groups in the molecule is preferably a radically polymerizable group and includes a (meth) acryloyl group. In this case, radical polymerization can be more excellent. Here, the (meth) acryloyl group means a radically polymerizable group represented by the following formula (A).

(A)

In the above formula (A), X is hydrogen or methyl, and is linked to other atoms in the radically polymerizable first compound, such as carbon, oxygen, sulfur, nitrogen and the like, in *.

The radically polymerizable compound containing at least two hydroxy groups in the molecule may be at least one selected from the group consisting of compounds represented by the following formulas (A1) to (A18).

(A1)

(A2)

(A3)

(A4)

(A5)

[Formula A6]

(A7)

(A8)

(A9)

(A10)

(A11)

(A12)

(A13)

(A14)

(A15)

 (A16)

(A17)

(A18)

The radically polymerizable compound having at least two hydroxyl groups in the molecule may be thermosetting. In this case, since the adhesive composition containing the radical polymerizing compound can be cured by thermal curing, a separate photo-radical initiator is not required There is an advantage that a thermally more stable adhesive layer can be formed.

Examples of the polymerizable compound include a radically polymerizable compound containing at least one carboxyl group in a molecule conjugated with a carbon-carbon unsaturated double bond present in the side chain, And a compound represented by the formula [A35].

[A31]

(A32)

(A33)

(A34)

(A35)

Another example of the radically polymerizable compound may further include a compound having an acid value of 100 to 1000 mg KOH / g.

Here, the compound having an acid value of 100 to 1000 mg KOH / g may be at least one compound selected from the group consisting of compounds represented by the following formulas (A19) to (A30).

(A19)

(A20)

(A21)

또는

이고, p는 1 내지 5의 정수임)(Wherein R 'is

or

And p is an integer of 1 to 5)

(A22)

(A23)

[A24]

(A25)

(A26)

(A27)

(A28)

(A29)

(A30)

The radical initiator is used for promoting radical polymerization to improve the curing rate. As the radical initiator, radical initiators generally used in the art may be used without limitation.

More specifically, the radical initiator can be, for example, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy- (2-hydroxy-2-methyl-1-phenyl-1-propanone) Methyl-2-methyl-1-propanone, methylbenzoylformate, oxy-phenyl-acetic acid -2- [2-oxo-2- Phenyl-acetoxy-ethoxy] -ethyl ester, oxy-phenyl-acetic acid 2- [2-hydroxy- 2-hydroxy-ethoxy] -ethyl ester, alpha-dimethoxy-alpha-phenylacetophenone, 2- Benzyl-2- (dimethylamino) -1- [4- (4-morpholinyl) phenyl] -1- -1-butanone), 2-methyl-1- [4- ( (Methylthio) phenyl] -2- (4-morpholinyl) -1-propanone), di (2,4,6-trimethylbenzoyl) -phosphine oxide, phosphine oxide, phenylbis (2,4,6-trimethylbenzoyl) -phosphine oxide, ) -Phosphine oxide (phenylbis (2,4,6-trimethylbenzoyl) -phosphine oxide). Particularly, in the present invention, phenylbis (2,4,6-trimethylbenzoyl) -phosphine oxide may be preferably used.

The radical initiator may be used in an amount of about 0.5 to 20 parts by weight, preferably about 0.5 to 15 parts by weight, more preferably about 0.5 to 10 parts by weight, based on 100 parts by weight of the whole adhesive composition. When the content of the radical initiator satisfies the above-described numerical range, the adhesive can be cured smoothly.

According to another embodiment of the present application, the adhesive composition further comprises an epoxy compound. The epoxy compound can further improve the water resistance.

The epoxy compound means a compound containing at least one epoxy group in the molecule. The epoxy compound is not particularly limited as long as it has at least one epoxy group in the molecule, and examples thereof include an aromatic epoxy compound, a hydrogenated epoxy compound, an alicyclic epoxy compound, and an epoxy group-containing (meth) acrylic compound . These may be used alone or in combination of two or more.

Here, the aromatic epoxy compound means an epoxy compound containing at least one aromatic hydrocarbon ring in the molecule, and examples thereof include, but are not limited to, diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F Bisphenol-type epoxy resins such as diglycidyl ether of diester ether and bisphenol S; Novolak type epoxy resins such as phenol novolak epoxy resin, cresol novolak epoxy resin and hydroxybenzaldehyde phenol novolac epoxy resin; Glycidyl ethers of tetrahydroxyphenylmethane, glycidyl ethers of tetrahydroxybenzophenone, and epoxy polyvinylphenols, and the like.

The hydrogenated epoxy compound refers to an epoxy compound obtained by selectively hydrogenating the aromatic epoxy compound under pressure in the presence of a catalyst.

The alicyclic epoxy compound means an epoxy compound in which an epoxy group is formed between adjacent two carbon atoms constituting an aliphatic hydrocarbon ring, but is not limited thereto. For example, 2- (3, Epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4,5- Epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6-methylcyclohexanecarboxylate, vinylcyclohexanedioxide, bis (3,4-epoxycyclohexylmethyl) adipate, bis Epoxycyclohexylmethyl) adipate, exo-exobis (2,3-epoxycyclopentyl) ether, endo-exobis (2,3-epoxycyclopentyl) ether, 2,2-bis [4 - (2,3-epoxypropoxy) cyclohexyl] propane, 2,6-bis (2,3-epoxypropoxycyclohexyl-p-dioxane), 2,6- Bis (3,4-epoxycyclohexyl) propane, dicyclopentadienedioxide, 1,2-epoxy-6- (2,3-epoxypropoxy) ), Hexahydro-4,7-methanoindane, p- (2,3-epoxy) cyclopentylphenyl-2,3-epoxypropyl ether, 1- (2,3-epoxypropoxy) (2,3-epoxy) cyclopentylphenyl-2,3-epoxypropyl ether), 1,2-bis [5- (1,2-epoxy) (3,4-epoxycyclohexane) ethylene glycol di (3,4-epoxycyclohexylmethyl) ether, ethylenebis (3,4-epoxycyclohexylmethyl) ethanocyclopentenylphenyl glycidyl ether, 3,4-epoxycyclohexanecarboxylate), and the like.

The epoxy group-containing (meth) acrylic compound means a compound containing both an epoxy group and a (meth) acryloyloxy group in the molecule, and includes, for example, glycidyl acrylate, 2-methyl Glycidyl acrylate, 3,4-epoxybutyl acrylate, 6,7-epoxyheptyl acrylate, 3,4-epoxycyclohexyl acrylate, glycidyl methacrylate, 2-methylglycidyl methacrylate , 3,4-epoxybutyl methacrylate, 6,7-epoxyheptyl methacrylate, 3,4-epoxycyclohexyl methacrylate, and 4-hydroxybutyl acrylate glycidyl ether.

On the other hand, the epoxy compound preferably contains at least one selected from the group consisting of an alicyclic epoxy compound and an epoxy group-containing (meth) acrylic compound. At this time, the alicyclic epoxy compound is an epoxy compound having at least two epoxy groups and at least two alicyclic rings in the molecule, for example, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (Meth) acryl-based compound is particularly preferable. Among them, glycidyl (meth) acryl-based compounds such as glycidyl acrylate and glycidyl methacrylate are particularly preferable. In this case, the effect of improving the water resistance of the adhesive composition of the present invention is excellent.

The content of the epoxy compound may be about 1 to 30 parts by weight, preferably about 4 to 25 parts by weight, and more preferably about 5 to 20 parts by weight based on 100 parts by weight of the total adhesive composition. When the epoxy compound satisfies the above content range, the adhesive composition can secure excellent adhesive force and water resistance.

According to one embodiment of the present application, the adhesive composition may further comprise an acid or photoacid generator.

According to one embodiment of the present application, the adhesive composition may further comprise an acid. When the composition contains an acid, the coordination bond to the central metal may be broken, and the adhesion of the polarizer to the hydroxyl group may be increased.

Acids that can be used include, but are not limited to, acetic acid, acrylic acid, p- TSA, acryloyloxyethyl phosphate and the like. The pH is adjusted to between 1 and 7 using the indicated acid. The pH is preferably 1 to 6, more preferably 2 to 6.

The photoacid generator means a compound which generates an acid (H < + >) by an active energy ray. As the photoacid generator that can be used in the present invention, for example, a sulfonium salt or an iodonium salt is preferably included. Specific examples of the photoacid generator containing a sulfonium salt or an iodonium salt include diphenyl (4-phenylthio) phenylsulfonium hexafluoroantimonate (Diphenyl (4- phenylthio) phenylsulfonium hexafluoroantimonate), diphenyl (4-phenylthio) phenylsulfonium hexafluorophosphate, phenyl (4- (2-methylpropyl) phenyl] -iodonium hexa (2-methylpropyl) phenyl] -iodonium hexafluorophosphate, (thiodi-4,1-phenylene) bis (diphenylsulfonium) dihexafluoroantimonate ((Thiodi- 4,1-phenylene) bis (diphenylsulfonium) dihexafluoroantimonate and thiodi-4,1-phenylene bis (diphenylsulfonium) bis (diphenylsulfonium) dihexafluoroantimonate) dihexafluorophosphate), but is limited to at least one selected from the group consisting of is.

The content of the photoacid generator may be about 0.5 to 15 parts by weight, preferably about 0.5 to 12 parts by weight, more preferably about 0.5 to 10 parts by weight, based on 100 parts by weight of the whole adhesive composition. When the photoacid generator satisfies the above content range, it is advantageous not only to cure the adhesive smoothly, but also to impart excellent water resistance.

As described above, the pH can be controlled by using an acid or a photoacid generator, and thereby the binding with the polarizer can be made more excellent. In particular, when a photoacid generator is used, the adhesive force may increase. Specifically, in the case of a structure in which an alkoxy group is chelated in Ti, control of the acidity results in an increase in adhesive force based on the result of the experiment based on the possibility that the chelated functional group can be covalently bonded while falling off.

According to one embodiment of the present application, the adhesive composition may further comprise a photosensitizer. Examples of the photosensitizer include a carbonyl compound, an organic sulfur compound, a persulfate compound, a redox compound, an azo compound and a diazo compound, an anthracene compound, a halogen compound, a light reducing pigment and the like. no. The content of the photosensitizer may be 0.1 to 10 parts by weight, preferably 0.1 to 5 parts by weight, more preferably 0.1 to 3 parts by weight, based on 100 parts by weight of the total adhesive composition.

Another embodiment of the present application is a polarizer comprising: a polarizer; An adhesive layer formed on at least one surface of the polarizer; And a polarizer protective film formed on the adhesive layer, wherein the adhesive layer is formed using an adhesive composition according to the above-described embodiments.

The adhesive strength between the polarizer and the polarizer protective film adhered by the adhesive layer formed using the adhesive composition comprising the compound of Formula 1 is 1.5 N / 2 cm to 3.0 N / 2 cm.

Hereinafter, the polarizer and the optical member including the adhesive composition of the present invention will be described in detail.

Polarizer

First, a polarizing plate according to the present invention will be described.

The polarizer of the present invention comprises a polarizer; An adhesive layer formed on at least one surface of the polarizer; And a protective film formed on the adhesive layer, wherein the adhesive layer is formed using an adhesive composition according to the above-described embodiments.

Polarizer

First, the polarizer is not particularly limited, and a film made of polyvinyl alcohol (PVA) including a polarizer well known in the art, for example, iodine or a dichroic dye, can be used. The polarizer may be prepared by saponifying iodine or a dichroic dye to a PVA film, but the production method thereof is not particularly limited. In the present specification, the polarizer means a state not including a protective film, and the polarizer means a state including a polarizer and a protective film.

Adhesive layer

Next, the adhesive layer is formed using an adhesive composition according to the above-described embodiments of the present invention, and can be formed by a method well known in the art. For example, the adhesive composition may be applied to one side of the polarizer or the protective film to form an adhesive layer, and then the polarizer and the protective film are laminated and cured. At this time, the application may be performed by coating methods well known in the art, for example, spin coating, bar coating, roll coating, gravure coating, blade coating and the like.

On the other hand, the curing can be performed by irradiating an active energy ray such as an ultraviolet ray, a visible ray, an electron ray, or the like. For example, a method of irradiating ultraviolet light of about 10 to 2500 mJ / cm ² using a metal halide lamp.

Alternatively, the curing may be performed by thermal curing, more specifically by thermal curing at a curing temperature of 80 or more. At this time, if necessary, a known amine-based initiator may be further added to the composition in order to accelerate the curing rate upon thermal curing.

Alternatively, the curing may be to further perform thermosetting after the photo-curing, or may be to further perform photo-curing after thermosetting.

On the other hand, the thickness of the adhesive layer is preferably in the range of more than 0 to 20 μm or less, more preferably 0 to 10 μm or less, preferably 0.1 to 10 μm or 0.1 to 5 μm or so. If the thickness of the adhesive layer is too thin, the uniformity of the adhesive layer and the adhesive force may be lowered. If the thickness of the adhesive layer is too thick, the appearance of the polarizer may be wrinkled.

Protective film

The protective film is used for supporting and protecting the polarizer, and may be formed of protective films of various materials commonly known in the art, for example, a cellulose-based film, a polyethylene terephthalate (PET) film, a cycloolefin polymer COP, cycloolefin polymer) film, acrylic film, and the like. Of these, it is particularly preferable to use an acrylic film in consideration of optical characteristics, durability, economical efficiency and the like.

On the other hand, the acrylic film usable in the present invention can be obtained by molding a molding material containing a (meth) acrylate resin as a main component by extrusion molding. In this case, the (meth) acrylate-based resin contains a resin containing a (meth) acrylate-based unit as a main component, and includes not only a homopolymer resin composed of a (meth) acrylate- But also a copolymer resin in which other monomer units are copolymerized and a blend resin in which another resin is blended with the above (meth) acrylate resin.

On the other hand, the (meth) acrylate-based unit may be, for example, an alkyl (meth) acrylate-based unit. Here, the alkyl (meth) acrylate-based unit means both an alkyl acrylate-based unit and an alkyl methacrylate-based unit, and the alkyl (meth) acrylate-based alkyl group preferably has 1 to 10 carbon atoms , More preferably from 1 to 4 carbon atoms.

Examples of the monomer unit copolymerizable with the (meth) acrylate-based unit include a styrene-based unit, a maleic anhydride-based unit, and a maleimide-based unit. Examples of the styrene-based unit include, but are not limited to, styrene,? -Methylstyrene, and the like; Examples of the maleic anhydride monomer include, but are not limited to, maleic anhydride, methylmaleic anhydride, cyclohexylmaleic anhydride, phenylmaleic anhydride and the like; Examples of the maleimide-based monomer include, but are not limited to, maleimide, N-methylmaleimide, N-cyclohexylmaleimide, and N-phenylmaleimide. These may be used alone or in combination.

On the other hand, the acrylic film may be a film containing a (meth) acrylate resin having a lactone ring structure. Specific examples of the (meth) acrylate resin having a lactone ring structure include, for example, lactones described in Japanese Unexamined Patent Application Publication No. 2000-230016, Japanese Unexamined Patent Application Publication No. 2001-151814, Japanese Unexamined Patent Application Publication No. 2002-120326, (Meth) acrylate-based resin having a cyclic structure.

The method for producing the acrylic film is not particularly limited and, for example, a (meth) acrylate resin and other polymers and additives may be thoroughly mixed by any suitable mixing method to prepare a thermoplastic resin composition, Or a (meth) acrylate resin, other polymers, additives and the like may be prepared as separate solutions and then mixed to form a homogeneous mixture solution, and then the mixture may be formed into a film. The acrylic film may be either an unstretched film or a stretched film. In the case of a stretched film, it may be a uniaxially stretched film or a biaxially stretched film, and in the case of a biaxially stretched film, it may be a simultaneous biaxially stretched film or a sequential biaxially stretched film.

Meanwhile, the polarizing plate of the present invention may further include a primer layer between the adhesive layer and the protective film to further improve the adhesive force. At this time, the primer layer may be formed by applying a coating liquid containing a water-dispersible polymer resin and water on a protective film by using a bar coating method, a gravure coating method, and drying. The water-dispersible polymer resin may be, for example, a water-dispersed polyurethane resin, a water-dispersed acrylic resin, a water-dispersed polyester resin or a combination thereof. The coating liquid may further include water-dispersible fine particles. The water-dispersible fine particles may be inorganic fine particles such as silica, titania, alumina and zirconia, organic fine particles made of a silicone resin, a fluorine resin, a (meth) acrylic resin, a crosslinked polyvinyl alcohol and a melamine resin or a combination thereof. The present invention is not limited thereto. However, the following examples are intended to illustrate the present invention and are not intended to limit the scope of the present invention.

Composition A

3 parts by weight of a radical initiator irgacure-819 (Ciba) was added to 100 parts by weight of a resin composition prepared by adding 90% by weight of hydroxyethyl acrylate and 10% by weight of KR44 (Kenrich Petrochemicals) Composition A was prepared.

Composition B

3 parts by weight of a radical initiator irgacure-819 (Ciba) was added to 100 parts by weight of a resin composition prepared by adding 90% by weight of hydroxyethyl acrylate and 10% by weight of KR44-acrylate (synthetic) to prepare an adhesive composition B for a polarizer Respectively.

Composition C

3 parts by weight of a radical initiator irgacure-819 (Ciba) was added to 100 parts by weight of a resin composition prepared by adding 90% by weight of BMAA (N- (butoxymethyl) acrylamide) and 10% by weight of KR44 (Kenrich Petrochemicals) Composition C was prepared.

Composition D

3 parts by weight of a radical initiator irgacure-819 (Ciba) was added to 100 parts by weight of a resin composition prepared by adding 90% by weight of BMAA (N- (butoxymethyl) acrylamide) and 10% by weight of KR44-acrylate Composition D was prepared.

Composition E

To 100 parts by weight of a resin composition prepared by adding 80% by weight of hydroxyethyl acrylate and 20% by weight of KR44-acrylate (synthetic), 3 parts by weight of a radical initiator irgacure-819 (Ciba) was added to prepare an adhesive composition E for a polarizer Respectively.

Composition F

3 parts by weight of a radical initiator irgacure-819 (Ciba) was added to 100 parts by weight of a resin composition prepared by adding 80% by weight of BMAA (N- (butoxymethyl) acrylamide) and 20% by weight of KR44-acrylate Composition F was prepared.

Composition G

3 parts by weight of a radical initiator irgacure-819 (Ciba), 10 parts by weight of CPI 100P (Sanapro), 5 parts by weight of a photo acid generator, 10 parts by weight of a resin composition prepared by adding 90% by weight of hydroxyethyl acrylate and 10% by weight of KR44 (Kenrich Petrochemicals) Was added to prepare an adhesive composition G for a polarizing plate.

Composition H

3 parts by weight of a radical initiator irgacure-819 (Ciba), 10 parts by weight of CPI 100P (Sanapro), which is a photo acid generator, and 5 parts by weight of a photoacid generator were added to 100 parts by weight of a resin composition prepared by adding 90% by weight of hydroxyethyl acrylate and 10% by weight of KR44- Was added to prepare an adhesive composition H for a polarizing plate.

Composition I

Epoxycyclohexylmethyl-3,4'-epoxycyclohexanecarboxylate (manufactured by Dicel) was added to 100 parts by weight of a resin composition prepared by adding 90% by weight of hydroxyethyl acrylate and 10% by weight of KR44-acrylate 3 parts by weight of a radical initiator irgacure-819 (Ciba) and 5 parts by weight of a photo acid generator, CPI 100P (Sanapro) were added to prepare an adhesive composition H for a polarizing plate.

Composition J

Irgacure-819 (manufactured by Ciba) as a radical initiator was added to 100 parts by weight of a resin composition prepared by adding 81.8% by weight of hydroxyethyl acrylate, 9.1% by weight of KR44-acrylate (synthetic) and 9.1% by weight of dimethylol tricyclodecane di- 3 parts by weight were added to prepare an adhesive composition J for a polarizing plate.

Composition K

3 parts by weight of a radical initiator irgacure-819 (manufactured by Ciba) was added to 100 parts by weight of a resin composition prepared by adding 100% by weight of hydroxyethyl acrylate to prepare an adhesive composition K for a polarizing plate.

Composition L

100 parts by weight of BMAA (N- (butoxymethyl) acrylamide) was added to 100 parts by weight of the resin composition, and 3 parts by weight of a radical initiator irgacure-819 (Ciba) was added to prepare an adhesive composition L for a polarizing plate.

Composition M

To 100 parts by weight of a resin composition prepared by adding 90% by weight of hydroxyethyl acrylate and 10% by weight of 2-isocyanatoethyl acrylate (Karenz AOI, Showa Denko) was added 3 parts by weight of a radical initiator irgacure-819 Was added to prepare an adhesive composition M for a polarizing plate.

Composition R

To 100 parts by weight of phenoxyl benzyl acrylate (Miramer M1122, Miwon Specialty Chemical), 3 parts by weight of a radical initiator irgacure-819 (Ciba) was added to prepare an adhesive composition R for a polarizing plate.

Experimental Example  1 - Adhesion evaluation

The adhesion of the composition to the polarizer was measured and shown in Table 2 below. Specifically, a polarizer (PVA element) was laminated on the polarizer (PVA element) at a thickness of 2 to 3 占 퐉, the laminate was passed through a laminator, and then irradiated with ultraviolet rays at 200 mJ / cm < ² > to prepare a peel force sample composed of a polarizer / adhesive / polarizer. The prepared samples were cut to a width of 20 mm and a length of 100 mm and peel strengths were measured at a speed of 300 m / min and 90 degrees with a Texture Analyzer (Stable Micro Systems TA-XT Plus). At this time, the peeling force was indicated. ?, 2.0 when the peeling force is 2.5 N / 2 cm or more,?, When the peeling force is 2.0 to 2.5 N / 2 cm, and when the peeling force is 1.5 N / 2 cm or less,

Experimental Example  2 - Evaluation of bonding strength of adhesive

The glass transition temperature was measured to confirm the bonding force between the adhesives. After the adhesive composition applied to 5㎛ between the PET film with a release force and hardened to 200mJ / cm ² was measured for a glass transition temperature of the cured product formed by using the (DSC823 model METTLER TOLEDO社) DSC. The temperature range was -30 ~ 200 ℃ and 2 ^nd run Tg was used as a reference.

division Adhesive composition Peel force [N / 2cm] Glass Transition Temperature [캜] Example 1 A 2.0 43 Example 2 B 3.0 50 Example 3 C 1.6 120 Example 4 D 2.0 121 Example 5 E 2.6 51 Example 6 F 1.7 119 Example 7 G 2.5 50 Example 8 H 3.2 55 Example 9 I 3.3 61 Example 10 J 2.0 57 Comparative Example 1 K 2.0 14 Comparative Example 2 L 0.1 118 Comparative Example 3 M 1.1 20 Comparative Example 4 R 0.4 8

As shown in Table 2, the adhesive layers prepared in Examples 1 to 10 exhibited excellent peel strength or glass transition temperature as compared with Comparative Examples.

Claims (6)

An adhesive composition comprising a compound of formula
[Chemical Formula 1]

In formula (1)
X1 is hydrogen, hydroxy, substituted or unsubstituted alkoxy, or substituted or unsubstituted aryloxy,
X2 is hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, or

Lt;
L1 to L3 are the same or different and each independently represents a substituted or unsubstituted alkylene, a substituted or unsubstituted arylene, a substituted or unsubstituted alkylarylene, or a substituted or unsubstituted arylalkylene,
R is hydrogen or substituted or unsubstituted alkyl,
n is an integer of 0 to 3, m is an integer of 1 to 4, and n + m is 4. The adhesive composition according to claim 1, wherein the formula (1) is represented by the following formula (3) or (4):
(3)

[Chemical Formula 4]

In the above formulas (3) and (4), the substituent is as defined in formula (1). The adhesive composition of claim 1, further comprising a polymerizable compound and a radical initiator. The adhesive composition according to claim 1, further comprising an epoxy compound. The adhesive composition according to claim 1, further comprising an acid or photoacid generator. A polarizer; An adhesive layer formed on at least one surface of the polarizer; And a polarizer protective film formed on the adhesive layer, wherein the adhesive layer is formed using the adhesive composition according to any one of claims 1 to 5.

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