KR102223918B1 - Adhesive film for polarizing plate, polarizing plate comprising the same and optical display apparatus comprising the same - Google Patents

Abstract

It is formed of a pressure-sensitive adhesive composition for a polarizing plate comprising a (meth)acrylic copolymer, a curing agent, a tackifying resin, and an ionic liquid, and the curing agent is included in an amount of 1 to 20 parts by weight based on 100 parts by weight of the (meth)acrylic copolymer. In addition, the adhesive film for a polarizing plate is provided with an adhesive film for a polarizing plate having a value of 100 Pa/° C. or more, a polarizing plate including the same, and an optical display device including the same.

Description

Adhesive film for a polarizing plate, a polarizing plate including the same, and an optical display device including the same {ADHESIVE FILM FOR POLARIZING PLATE, POLARIZING PLATE COMPRISING THE SAME AND OPTICAL DISPLAY APPARATUS COMPRISING THE SAME}

The present invention relates to an adhesive film for a polarizing plate, a polarizing plate including the same, and an optical display device including the same. More specifically, the present invention relates to an adhesive film for a polarizing plate, a polarizing plate including the same, and an optical display device including the same, which improves panel warpage at high temperature or high temperature and high humidity, and has excellent durability at high temperature or high temperature and high humidity.

A liquid crystal display device includes a liquid crystal panel and polarizing plates attached to both surfaces of the liquid crystal panel. The polarizing plate includes a polarizer and a protective film formed on one or both sides of the polarizer to protect the polarizer. The polarizing plate is attached to the liquid crystal panel by an adhesive film for a polarizing plate.

The adhesive film for polarizing plates is formed by curing an adhesive composition for polarizing plates containing a (meth)acrylic copolymer and a curing agent under predetermined conditions. However, when the curing agent is included, there is a problem that it is cumbersome because the content of the monomer reacting with the curing agent in the (meth)acrylic copolymer must be adjusted to secure desired physical properties.

An adhesive film having a high modulus even at a high temperature may cause a decrease in durability such as lifting, drag, or bubble generation of the polarizing plate, or a panel warpage. The decrease in durability occurs due to shrinkage due to heat and/or moisture of the polarizer.

The background technology of the present invention is disclosed in Japanese Laid-Open Patent No. 2014-032270.

The problem to be solved by the present invention is to provide an adhesive film for a polarizing plate that can improve panel warpage at high temperature or high temperature and high humidity.

Another problem to be solved by the present invention is to provide an adhesive film for a polarizing plate having excellent durability at high temperature or high temperature and high humidity.

The adhesive film for a polarizing plate of the present invention is formed of a pressure-sensitive adhesive composition for a polarizing plate comprising a (meth)acrylic copolymer, a curing agent, a tackifying resin, and an ionic liquid, and the curing agent is based on 100 parts by weight of the (meth)acrylic copolymer. It is included in an amount of 1 to 20 parts by weight, and the adhesive film for a polarizing plate may have a value of 100Pa/°C or more:

<Equation 1>

||G'(70)-G'(100)|/(100℃-70℃)| -||G'(25)-G'(70)|/(70℃-25℃)|

(In Equation 1, G'(25) is the modulus at 25° C. of the adhesive film for a polarizing plate (unit: Pa),

G'(70) is the modulus of the adhesive film for the polarizing plate at 70°C (unit: Pa),

G'(100) is the modulus (unit: Pa) at 100° C. of the adhesive film for the polarizing plate).

The polarizing plate of the present invention may include the adhesive film for the polarizing plate of the present invention.

The optical display device of the present invention may include the polarizing plate of the present invention.

The present invention provides an adhesive film for a polarizing plate capable of improving panel warpage at high temperature or high temperature and high humidity.

The present invention provides an adhesive film for a polarizing plate having excellent durability at high temperature or high temperature and high humidity.

1 shows the aspect of tanδ according to the temperature of the adhesive film for a polarizing plate according to an embodiment of the present invention.
2 is a plan view of a specimen for measuring panel warpage in an experimental example.

With reference to the accompanying drawings, embodiments will be described in detail so that those of ordinary skill in the art may easily implement the present invention. The present invention may be implemented in various different forms and is not limited to the embodiments described herein.

In the present specification, “adhesive film for polarizing plate” and “adhesive composition for polarizing plate” may be respectively referred to as “adhesive film” and “adhesive composition”. In the present specification, "(meth)acrylic" means acrylic and/or methacrylic.

In the present specification, the "modulus" of the adhesive film is a storage modulus (G').

In the present specification, "tanδ" of the adhesive film is the ratio of the loss modulus (G") to the storage modulus (G').

Hereinafter, an adhesive film for a polarizing plate according to an embodiment of the present invention will be described.

The adhesive film for a polarizing plate may have a value of 100 Pa/° C. or higher in the following formula:

<Equation 1>

||G'(70)-G'(100)|/(100℃-70℃)| -||G'(25)-G'(70)|/(70℃-25℃)|

(In Equation 1, G'(25) is the modulus at 25° C. of the adhesive film for a polarizing plate (unit: Pa),

G'(70) is the modulus of the adhesive film for the polarizing plate at 70°C (unit: Pa),

G'(100) is the modulus (unit: Pa) at 100° C. of the adhesive film for the polarizing plate).

In Equation 1, G'(25), G'(70), and G'(100) are measured under the same conditions for the adhesive film for a polarizing plate, but are values obtained at 25°C, 70°C, and 100°C, respectively.

Equation 1 is an adhesive film having a high modulus with a modulus of 1 x 10 ⁵ Pa or more at 25°C. When the modulus increases or decreases with an increase in temperature, the modulus decreases as the temperature increases, but from about 65° C. to about 85° C. It is to evaluate whether the modulus is rapidly lowered and the adhesive film can minimize panel warpage at high temperature or high temperature and high humidity while maintaining adhesive strength at high temperature or high temperature and high humidity. When an adhesive film having a modulus of 1 x 10 ⁵ Pa or more of an adhesive film at 25°C has a value of 100Pa/°C or more, it is possible to minimize panel warpage at high temperature or high temperature and high humidity while maintaining adhesive strength at high temperature or high temperature and high humidity. . Preferably, the value of Equation 1 may be 100Pa/℃ to 500Pa/℃, more preferably 100Pa/℃ to 350Pa/℃.

In Equation 1, G'(25)> G'(70)> G'(100).

In Equation 1, |G'(70)-G'(100)| may be ^{greater than 2.0 x 10 4} Pa, for example, 2.1 x 10 ⁴ Pa to 10 x 10 ⁴ Pa. In the above range, it is possible to satisfy Equation 1 and minimize panel warpage at high temperature or high humidity.

In Equation 1, |G'(25)-G'(70)| may be 3.5 x 10 ⁴ Pa or more, for example, 3.6 x 10 ⁴ Pa to 10 x 10 ⁴ Pa. In the above range, it is possible to satisfy Equation 1 and minimize panel warpage at high temperature or high humidity.

In the adhesive film according to the present embodiment, the modulus decreases as the temperature increases, but the modulus decrease slope (based on a positive value) increases rapidly at about 65°C to about 85°C.

As an adhesive film having a value of Equation 1 of 100Pa/°C or higher, the adhesive film of an embodiment of the present invention may have a minimum tanδ value of 65°C to 85°C among 25°C to 100°C. 1 shows tan δ according to the temperature of an adhesive film according to an embodiment of the present invention. Referring to Figure 1, the adhesive film at 25 ℃ to 100 ℃, tanδ decreases as the temperature increases at 25 ℃, there is a minimum value at 65 ℃ to 85 ℃, U-shaped or V-shaped that increases again after 85 ℃. It can be seen that it represents. The pressure-sensitive adhesive film may have a minimum value of tanδ of 0.10 to 0.20 at 65°C to 85°C, for example 70°C. In the above range, it may be effective to improve warpage due to a change in stress of the pressure-sensitive adhesive.

The pressure-sensitive adhesive film may be formed of the pressure-sensitive adhesive composition for a polarizing plate of the present invention comprising a (meth)acrylic copolymer, a curing agent, a tackifying resin, and an ionic liquid. This will be described in detail.

The (meth)acrylic copolymer forms a matrix of an adhesive film and imparts adhesive force. The (meth)acrylic copolymer may form a semi-IPN (interpenetrating polymer network) structure by a curing agent. By adding a curing agent, a tackifier resin, and an ionic liquid to the semi IPN structure, the value according to Equation 1 above can be expressed.

The (meth)acrylic copolymer is a (meth)acrylate having an alkyl group; And a (meth)acrylate having a hydroxyl group, a monomer having a carboxylic acid group, a monomer having an aromatic group, a monomer having an alicyclic group, and a monomer having a heteroalicyclic group. Preferably, the (meth)acrylic copolymer may include a (meth)acrylic copolymer having a hydroxyl group.

(Meth)acrylate having an alkyl group is a (meth)acrylate having an unsubstituted C1 to C20 alkyl group, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (Meth)acrylate, t-butyl (meth)acrylate, iso-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, heptyl ( It may include at least one of meth) acrylate, octyl (meth) acrylate, iso-octyl (meth) acrylate, nonyl (meth) acrylate, and decyl (meth) acrylate, but is not limited thereto. These may be included alone or in combination of two or more. The (meth)acrylate having an alkyl group may be included in an amount of 65% to 99% by weight, specifically 90% to 99% by weight of the monomer mixture. In the above range, it is possible to provide mechanical strength to the adhesive film and have excellent adhesive properties.

The (meth)acrylate having a hydroxyl group may include a (meth)acrylate having one or more hydroxyl groups, a C1 to C20 alkyl group, a C3 to C10 cycloalkyl group, or a C6 to C20 aryl group. Specifically, the (meth)acrylate having a hydroxyl group is 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (Meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 1,4-cyclohexanedimethanol mono (meth)acrylate, 1-chloro-2-hydroxypropyl (meth)acrylate, diethylene glycol At least one of mono (meth) acrylate, 2-hydroxy-3-phenyloxypropyl (meth) acrylate, 4-hydroxycyclopentyl (meth) acrylate, and 4-hydroxycyclohexyl (meth) acrylate Can include. These may be included alone or in combination of two or more. The (meth)acrylate having a hydroxyl group may be included in an amount of 1% to 35% by weight, specifically 1% to 10% by weight of the monomer mixture. In the above range, the degree of crosslinking of the adhesive film may be high and the adhesive force of the adhesive film to the protective film may be good.

Monomers having a carboxylic acid group are (meth)acrylic acid, 2-carboxyethyl (meth)acrylate, 3-carboxypropyl (meth)acrylate, 4-carboxybutyl (meth)acrylate, itaconic acid, crotonic acid, maleic acid, fumaric acid. And maleic anhydride. These may be included alone or in combination of two or more. The (meth)acrylate having a carboxylic acid group may be included in an amount of 0% to 5% by weight, specifically 1.5% to 2.5% by weight of the monomer mixture. In the above range, the degree of crosslinking of the adhesive film may be high and the adhesive force of the adhesive film to the protective film may be good.

The monomer having an alicyclic group may include (meth)acrylate having an alicyclic group having 3 to 10 carbon atoms, specifically cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, and the like.

The monomer having a hetero alicyclic group may include a (meth)acrylate having a heteroalicyclic group having 2 to 10 carbon atoms having oxygen, nitrogen or sulfur, specifically (meth)acryloylmorpholine.

In one embodiment, the (meth)acrylic copolymer is 65% to 99% by weight of (meth)acrylate having an alkyl group, specifically 90% to 99% by weight, and 1% by weight of (meth)acrylate having a hydroxyl group It may be a copolymer of 35% by weight, specifically 1% to 10% by weight.

The (meth)acrylic copolymer may have a weight average molecular weight (Mw) of 1.5 million or more, specifically 1.5 million to 3 million. In the above range, since the modulus of the adhesive film is high at 25° C., durability reliability of the adhesive film can be secured even if the modulus decreases at high temperature or high temperature and humidity according to Equation 1 above. The weight average molecular weight may be a value obtained by conversion of polystyrene in a gel permeation chromatography method. The (meth)acrylic copolymer may have a glass transition temperature of -30°C or less, specifically -65°C to -30°C. In the above range, it can have adhesive performance with excellent wetting properties. The (meth)acrylic copolymer may have a polydispersity of 2.0 to 10.0, specifically 3.0 to 7.0. In the above range, it is possible to ensure durability at high temperatures. The (meth)acrylic copolymer may have an acid value of 0.5 mgKOH/g or less, more specifically 0.1 mgKOH/g to 0.5 mgKOH/g. Within the above range, it is possible to directly or indirectly implement a corrosion preventing effect on the adherend.

The (meth)acrylic copolymer can be prepared by polymerizing a monomer mixture by a conventional polymerization method. The polymerization method may include conventional methods known to those skilled in the art. For example, the (meth)acrylic copolymer can be prepared by adding an initiator to the monomer mixture, and then by conventional copolymer polymerization, such as suspension polymerization, emulsion polymerization, solution polymerization, or the like. The polymerization temperature may be 65°C to 70°C, and the polymerization time may be 6 hours to 8 hours. The initiator is an azo polymerization initiator; And/or a conventional one containing a peroxide such as benzoyl peroxide or acetyl peroxide may be used.

The curing agent cures the (meth)acrylic copolymer. The curing agent is a polyfunctional curing agent, for example, an isocyanate-based curing agent, a metal chelate-based curing agent, an epoxy-based curing agent, an amine-based curing agent, and a carbodiimide-based curing agent. Preferably, the curing agent may be an isocyanate-based curing agent.

Specifically, the isocyanate-based curing agent may include a bifunctional or more, for example, a tri- to 6-functional isocyanate-based curing agent, and at this time, the modulus of the adhesive film can be easily increased. Specifically, the isocyanate-based curing agent is a trifunctional isocyanate curing agent including a trifunctional trimethylolpropane-modified toluene diisocyanate adduct, a trifunctional toluene diisocyanate trimer, and a trimethylolpropane-modified xylene diisocyanate adduct, 6 It may include at least one of functional trimethylolpropane-modified toluene diisocyanate and hexafunctional isocyanurate-modified toluene diisocyanate. These may be included alone or in combination of two or more.

In the pressure-sensitive adhesive film of the present invention, the curing agent is included in the pressure-sensitive adhesive composition in an excess amount compared to the prior art, thereby increasing the crosslinking density of the (meth)acrylic copolymer, thereby increasing the modulus of the adhesive film at 25°C. The curing agent may be included in an amount of 1 to 20 parts by weight, specifically 1 to 10 parts by weight, based on 100 parts by weight of the (meth)acrylic copolymer. In the above range, it is possible to increase the crosslinking density of the adhesive film and increase the modulus at 25° C. to satisfy the value of Equation 1, and to secure durability reliability even at high temperature or high temperature and high humidity.

The tackifying resin may be included in the pressure-sensitive adhesive composition so that the value of Formula 1 can be obtained together with the ionic liquid. Typically, the tackifier resin is included to increase the adhesion of the adhesive film. However, in the present invention, when the (meth)acrylic copolymer is cured to a high crosslinking density, the tackifying resin and the ionic liquid are included together, so that the value of Formula 1 can be obtained. In addition, in the present invention, it is possible to increase the modulus of the adhesive film at 25° C. by adjusting the content between the tackifying resin and the isocyanate-based curing agent. Specifically, the tackifying resin may be included in an amount of 50 parts by weight to 1000 parts by weight, specifically 100 parts by weight to 1000 parts by weight, based on 100 parts by weight of the curing agent. In the above range, it is possible to increase the modulus of the adhesive film at 25° C., and there may be an effect of increasing flexibility at high temperatures.

The tackifying resin may have a softening point of 50°C or higher, for example, 50°C to 200°C, 50°C to 150°C. In the above range, there may be an effect of imparting flexibility in modulus. The tackifying resin may have a weight average molecular weight of 2,000 g/mol to 20,000 g/mol, for example, 5,000 g/mol to 20,000 g/mol, and 8,000 g/mol to 20,000 g/mol. In the above range, there may be an effect of imparting flexibility in modulus.

The tackifying resin is an oligomer and may include a non-hydrogenated oligomer that is not hydrogenated. For example, the tackifying resin may include one or more oligomers of terpene phenol-based, styrene-based, and rosin-based oligomers.

The tackifying resin may be included in an amount of 10 parts by weight to 50 parts by weight, for example, 10 parts by weight to 20 parts by weight, based on 100 parts by weight of the (meth)acrylic copolymer. In the above range, it is possible to increase the crosslinking density of the adhesive film, increase the modulus at 25°C, and increase flexibility at high temperatures.

The ionic liquid may be included in the pressure-sensitive adhesive composition so that the value of Formula 1 can be obtained together with the tackifying resin. The ionic liquid is included in the pressure-sensitive adhesive composition having a high crosslinking density due to the curing agent and the tackifying resin, so that the modulus of the pressure-sensitive adhesive film decreases as the temperature increases, but the modulus rapidly decreases at about 65°C to about 85°C. When looking at the modulus change with temperature, the modulus decrease slope (positive value basis) in the temperature range of about 65°C or less and about 85°C or more is smaller than the modulus decrease slope (positive value basis) at about 65°C to about 85°C. Accordingly, in the present invention, panel warpage occurs due to shrinkage of polarizers at high temperature or high temperature and high humidity, and the use of an ionic liquid improves panel warpage at high temperature or high temperature and high humidity.

The ionic liquid may have a melting point of 25°C to 35°C, for example 26°C to 30°C. In the above range, the value according to Equation 1 can be obtained from the pressure-sensitive adhesive composition of the present invention.

The ionic liquid comprises non-polymeric or polymeric organic nitrogen, sulfonium or phosphonium onium cations and weakly coordinating organic anions.

The weakly coordinating anion is at least a hydrocarbon sulfonic acid (e.g., a hydrocarbon sulfonic acid having 1 to about 20 carbon atoms, e.g., an alkane, aryl or alkaryl sulfonic acid having 1 to about 8 carbon atoms, specific examples, methane or p-toluene sulfonic acid, most preferably p-toluene sulfonic acid).

Examples of weakly coordinating anions include organic anions such as alkanes, aryls and alkaryl sulfonates; Alkanes, aryls and alkaryl sulfates; Fluorinated and non-fluorinated tetraarylborates; And fluoroorganic anions such as fluorinated arylsulfonate, perfluoroalkanesulfonate, cyanoperfluoroalkanesulfonylamide, bis(cyano)perfluoroalkanesulfonylmethide, bis(perfluoro Roalkanesulfonyl)imide, cyanobis(perfluoroalkanesulfonyl)methide, bis(perfluoroalkanesulfonyl)methide, tris(perfluoroalkanesulfonyl)methide, and the like.

Examples of suitable weakly coordinating fluoroorganic anions include the following structures:

[Formula I]

[Formula II]

[Formula III]

(Wherein, each R ₆ may be independently, cyclic or bicyclic, saturated or unsaturated and optionally a chain (“in-chain”) or a terminal heteroatom such as N, O and S (E.g., -SF ₄ -or -SF ₅ ) is a fluorinated alkyl or aryl group, which may contain; Q is independently a SO ₂ or CO linking group; Y is QR ₆ , CN, halogen, H, alkyl, Is selected from aryl, Q-alkyl and Q-aryl; any two adjacent R ₆ groups may be joined to form a ring. Preferably, R ₆ is a perfluoroalkyl group, Q is SO ₂ , and each Y is QR ₆ ).

The fluoroorganic anion can be fully fluorinated, i.e. perfluorinated, or partially fluorinated (in its organic portion). Preferred fluoroorganic anions include those containing one or more highly fluorinated alkanesulfonyl groups, i.e., perfluoroalkanesulfonyl groups or partially fluorinated alkanesulfonyl groups, wherein all non-fluorine carbon-bonding substituents are sulfonyl It is bonded to a carbon atom rather than a carbon atom directly bonded to the group (preferably, all non-fluorine carbon-bonded substituents are bonded to a carbon atom three or more carbon atoms away from the sulfonyl group).

The nitrogen onium cation may be cyclic (i.e., the nitrogen atom(s) of the cation is a ring atom) or bicyclic (i.e., the nitrogen atom of the cation is not a ring atom(s), but may have a cyclic substituent). . Cyclic cations may be saturated or aromatic, which may have a degree of saturation, and bicyclic cations may be saturated or unsaturated. Cyclic cations may contain ring heteroatoms other than nitrogen (e.g., oxygen or sulfur), and the ring atoms may contain substituents (e.g., hydrogen, halogen, or alkyl, alicyclic, aryl, alkalicyclic, alkya). Organic groups such as reel, alicyclicalkyl, aralkyl, aralicyclic and alicyclic aryl groups). Separate alkyl substituents may be bonded to form one alkylene radical of 2 to 4 carbon atoms to form a ring structure that is collected on nitrogen.

Ionic liquids are a group of novel non-polymeric or polymeric compounds represented by the following general formula:

[Formula IV]

^{_{(R 1) t- v G +}} [(CH 2) q OR 2] v X -

(Wherein, each R ₁ includes an alkyl, alicyclic, aryl, alkalicyclic, alkaryl, alicyclicalkyl, aralkyl, aralicyclic or alicyclic aryl moiety, wherein the moiety is one It may contain more than one hetero atom, such as nitrogen, oxygen, sulfur, or may contain phosphorus or halogen (and thus may be a fluoroorganic in nature);

Each R ₂ contains hydrogen or the moiety described above for ^{R 1;}

G is nitrogen, sulfur or phosphorus; If G is sulfur, t is 3, if G is nitrogen or phosphorus, t is 4; If G is sulfur, v is an integer from 1 to 3, and if F is nitrogen or phosphorus, v is an integer from 1 to 4; q is an integer from 1 to 4; X is a weakly coordinating organic anion such as a fluoroorganic anion).

R ₁ is preferably alkyl, and R ₂ is preferably hydrogen, alkyl or acyl (more preferably hydrogen or acyl, most preferably hydrogen).

In the present invention, representative examples of useful ionic liquids include:

Octyldimethyl-2-hydroxyethylammonium bis(trifluoromethylsulfonyl)imide:

[C ₈ H ₁₇ N ⁺ (CH ₃ ) ₂ CH ₂ CH ₂ OH][ ^- N(SO ₂ CF ₃ ) ₂ ],

Octyldimethyl-2-hydroxyethylammonium perfluorobutanesulfonate:

[C ₈ H ₁₇ N ⁺ (CH ₃ ) ₂ CH ₂ CH ₂ OH][ ^- OSO ₂ C ₄ H ₉ ],

Octyldimethyl-2-hydroxyethylammonium trifluoromethanesulfonate:

[C ₈ H ₁₇ N ⁺ (CH ₃ ) ₂ CH ₂ CH ₂ OH][ ^- OSO ₂ CF ₃ ],

Octyldimethyl-2-hydroxyethylammonium tris(trifluoromethanesulfonyl)methide:

[C ₈ H ₁₇ N ⁺ (CH ₃ ) ₂ CH ₂ CH ₂ OH][ ^- C(SO ₂ CF ₃ ) ₃ ],

Trimethyl-2-acetoxyethylammonium bis(trifluoromethylsulfonyl)imide:

[(CH ₃ ) ₃ N ⁺ CH ₂ CH ₂ OC(O)CH ₃ ][ ^- N(SO ₂ CF ₃ ) ₂ ],

Trimethyl-2-hydroxyethylammonium bis(perfluorobutanesulfonyl)imide:

[(CH ₃ ) ₃ N ⁺ CH ₂ CH ₂ OH][ ^- N(SO ₂ C ₄ F ₉ ) ₂ ],

Triethylammonium bis(perfluoroethanesulfonyl)imide: [Et ₃ N ⁺ H][ ^- N(SO ₂ C ₂ F ₅ ) ₂ ],

With tetraethylammonium _{^{trifluoromethanesulfonate: [N + Et 4] [}} CF 3 SO 3 -],

Tetraethyl imide ammonium bis (trifluoromethane _{^{sulfonyl): [N + Et 4]}} [(CF 3 SO 2) 2 N -],

Tetramethylammonium tris(trifluoromethanesulfonyl)methide: [(CH ₃ ) ₄ N ⁺ ][ ^- C(SO ₂ CF ₃ ) ₃ ],

Tetrabutylammonium bis (trifluoromethane sulfonyl) _{imide: [(C 4 H 9)} 4 N +] [- N (SO 2 CF 3) 2],

Trimethyl-3-perfluorooctylsulfonamidopropylammonium bis(trifluoromethanesulfonyl)imide: [C ₈ F ₁₇ SO ₂ NH(CH ₂ ) ₃ N ⁺ (CH ₃ ) ₃ ][ ^- N( SO ₂ CF ₃ ) ₂ ],

1-hexadecyl to silpi bipyridinium bis (perfluoro-ethanesulfonyl) _{imide: [nC 16 H 33 - cyc} -N + C 5 H 5] [- N (SO 2 C 2 F 5) 2],

1-hexadecylpyridinium perfluorobutanesulfonate: [nC ₁₆ H ₃₃ - cyc -N ⁺ C ₅ H ₅ ][ ^- OSO ₂ C ₄ F ₉ ],

1-hexadecylpyridinium perfluorooctanesulfonate: [nC ₁₆ H ₃₃ - cyc -N ⁺ C ₅ H ₅ ][ ^- OSO ₂ C ₈ F ₁₇ ],

n- butyl-pyridinium bis (trifluoromethane sulfonyl) _{^{imide: - [- 2 N (SO}} 2 CF 3)], [nC 4 H 9 cyc -N + C 5 H 5]

n-butylpyridinium perfluorobutanesulfonate: [nC ₄ H ₉ - cyc -N ⁺ C ₅ H ₅ ][ ^- OSO ₂ C ₄ F ₉ ],

1, 3-ethyl-methylimidazolium (trifluoromethanesulfonyl) imidazolium _{bis-imide: [CH 3 - cyc - (} N + C 2 H 2 NCH) CH 2 CH 3] [- N (SO 2 CF 3) ₂ ],

1,3-ethylmethylimidazolium nonafluorobutanesulfonate: [CH ₃ -cyc -(N ⁺ C ₂ H ₂ NCH)CH ₂ CH ₃ ][ ^- OSO ₂ C ₄ F ₉ ],

1,3-ethyl methyl imidazolium methane sulfonate as trifluoroacetic _{carbonate: [CH 3 - cyc - (} N + C 2 H 2 NCH) CH 2 CH 3] [- OSO 2 CF 3],

Dodecylmethyl-bis(2-hydroxyethyl)ammonium bis(trifluoromethylsulfonyl)imide: [C ₁₂ H ₂₅ N ⁺ (CH ₃ )(CH ₂ CH ₂ OH) ₂ ][ ^- N(SO ₂ CF ₃ ) ₂ ],

1,2-dimethyl-3-propylimidazolium bis(trifluoromethanesulfonyl)imide,

1,2-dimethyl-3-propylimidazolium tris(trifluoromethanesulfonyl)methide,

1,2-dimethyl-3-propylimidazolium trifluoromethanesulfonyl perfluorobutanesulfonylimide,

1-ethyl-3-methylimidazolium cyanotrifluoromethanesulfonylamide,

1-ethyl-3-methylimidazolium bis(cyano)trifluoromethanesulfonylmethide,

1-ethyl-3-methylimidazolium trifluoromethanesulfonylperfluorobutanesulfonylimide,

Octyldimethyl-2-hydroxyethylammonium trifluoromethylsulfonylperfluorobutanesulfonylimide,

2-hydroxyethyltrimethyl trifluoromethylsulfonylperfluorobutanesulfonylimide,

2-methoxyethyltrimethylammonium bis(trifluoromethanesulfonyl)imide,

Octyldimethyl-2-hydroxyethylammonium bis(cyano)trifluoromethanesulfonylmethide,

Trimethyl-2-acetoxyethylammonium trifluoromethylsulfonylperfluorobutanesulfonylimide,

1-butylpyridinium trifluoromethylsulfonylperfluorobutanesulfonylimide,

2-ethoxyethyltrimethylammonium trifluoromethanesulfonate,

1-butyl-3-methylimidazolium perfluorobutanesulfonate,

Perfluoro-1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide,

1-ethyl-2-methylpyrazolium perfluorobutanesulfonate,

1-butyl-2-ethylpyrazolium trifluoromethanesulfonate,

N-ethylthiazolium bis(trifluoromethanesulfonyl)imide,

N-ethyloxazolium bis(trifluoromethanesulfonyl)imide,

1-butylpyrimidinium perfluorobutanesulfonylbis(trifluoromethanesulfonyl)methide,

Octyldimethyl-2-hydroxyethylammonium trifluoromethanesulfonate:

[C ₈ H ₁₇ N ⁺ (CH ₃ ) ₂ CH ₂ CH ₂ OH][ ^- OSO ₂ CF ₃ ],

Octyldimethyl-2-hydroxyethylammonium bis(trifluoromethylsulfonyl)imide:

[C ₈ H ₁₇ N ⁺ (CH ₃ ) ₂ CH ₂ CH ₂ OH][ ^- N(SO ₂ CF ₃ ) ₂ ],

Dodecylmethyl-bis(2-hydroxyethyl)ammonium bis(trifluoromethylsulfonyl)imide:[C ₁₂ H ₂₅ N ⁺ (CH ₃ )(CH ₂ CH ₂ OH) ₂ ][ ^- N(SO ₂ CF ₃ ) ₂ ],

Octyldimethyl-2-hydroxyethylammonium methanesulfonate,

Triethylammonium bis[(trifluoromethyl)sulfonyl]imide,

[(nC ₄ H ₉ ) ₃ (CH ₃ )N] ⁺ -[N(SO ₂ CF ₃ ) ₂ ] ^- , tri-n-butylmethylammonium bis(trifluoromethanesulfonyl)imide

In the present invention, the ionic liquid particularly useful for obtaining the value of Equation 1 is [(nC ₄ H ₉ ) ₃ (CH ₃ )N] ⁺ -[N(SO ₂ CF ₃ ) ₂ ] ^- , tri-n-butylmethylammonium Bis(trifluoromethanesulfonyl)imide, and the like.

Another specific group of ionic salts useful in preparing the ionic liquids of the present invention are novel non-polymeric or polymeric compounds having one or more cations having one or more polyoxyalkylene moieties bonded to one or more cationic nitrogen centers. Polymer salts have one or more weakly coordinating organic anions.

Polyoxyalkylene ammonium compounds contain cations. Further, this polyoxyalkylene ammonium compound contains an ammonium group bonded to the end of the polyoxyalkylene chain. Polyoxyalkylene chains are generally based on propylene oxide, ethylene oxide, or mixed ethylene/propylene oxide. Polyoxyalkylene ammonium compounds include mono-ammonium, di-ammonium and tri-ammonium compounds having a molecular weight of about 200 to about 10,000.

Particularly representative polyoxyalkylene ammonium compounds are those in which the cation is represented by the following general formula, wherein the number of repeating units in the polyoxyalkylene moiety is approximate:

[Formula V]

[Formula VI]

[Formula VII]

[Formula VIII]

[Formula IX]

[Formula X]

기이고, x, y 및 z는 동일하거나 상이하고, x+y+z가 5 이상이 되도록 하는 1 내지 30의 정수이고, POA는 식 ((CH₂)_mCH(R₃)O)로 나타내어지는 2 내지 50 유닛(각 유닛은 독립적으로 1 내지 4의 정수인 m 및 R₃을 가짐)을 포함한다. R₃은 독립적으로 수소 또는 저급 알킬기(즉, 1 내지 4의 탄소 원자를 함유)이다. R₄는 독립적으로, 임의로 하나 이상의 헤테로원자(예, 황, 질소, 산소), 염소, 브롬 또는 불소를 함유하는 알킬, 알리시클릭, 아릴, 알크알리시클릭, 아릴알리시클릭 또는 알리시클릭아릴기이다. R₅는 독립적으로, 임의로 하나 이상의 헤테로원자(예, 황, 질소, 산소), 염소, 브롬 또는 불소를 함유하는 수소, 알킬, 알리시클릭, 아릴, 알크알리시클릭, 아릴알리시클릭 또는 알리시클릭아릴기이다. d는 1 내지 4의 정수이다).(Where n is an integer of 3 to 50, b is an integer of 5 to 150, a and c are the same or different, and each is an integer of 0 to 5 (a + c is an integer of 2 to 5), A Is CH≡, CH ₃ C≡, CH ₃ CH ₂ C≡ or

Is a group, x, y and z are the same or different, and x+y+z is an integer of 1 to 30 such that it is 5 or more, and POA is represented by the formula ((CH ₂ ) _m CH(R ₃ )O) Ji contains 2 to 50 units (each unit independently _{has m and R 3,} which are integers from 1 to 4). R ₃ is independently hydrogen or a lower alkyl group (ie, containing 1 to 4 carbon atoms). R ₄ is independently, optionally one or more heteroatoms (e.g., sulfur, nitrogen, oxygen), chlorine, bromine or fluorine containing alkyl, alicyclic, aryl, alkalicyclic, arylalicyclic or alicyclic It is an aryl group. R ₅ is independently, optionally one or more heteroatoms (e.g., sulfur, nitrogen, oxygen), chlorine, bromine or fluorine containing hydrogen, alkyl, alicyclic, aryl, alkalicyclic, arylalicyclic or ali It is a cyclic aryl group. d is an integer from 1 to 4).

Examples of polyoxyalkylene amine compounds useful as precursors of the ionic liquid of the present invention are shown below. The number of repeating units in the polyoxyalkyrene moiety is approximate.

(Where x+y+z is ~5-6)

(Where b is ~8.5 and a+c is ~2.5)

(Where b is ~15.5 and a+c is ~2.5)

(Where x+y+z is ~30)

And

The polyoxyalkylene ammonium compound of the present invention can be prepared using methods known in the art.

Specific examples of polyoxyalkylene ammonium compounds useful as precursors of the ionic liquid of the present invention are as follows:

Examples of polyoxyalkylene ammonium compounds useful as the ionic liquid of the present invention are shown below. The number of repeating units in the polyoxyalkyrene moiety is approximate.

Examples of difunctional or trifunctional amine terminated polyethylene oxides useful as precursors of the ionic liquids of the present invention include, but are limited to, ^{JEFFAMINE™ polyalkylene amines available from Huntsman Corporation, Salt Lake City, Utah.} It is not. JEFFAMINE ^™ polyalkylene amines are generally described as containing primary amino groups attached to the ends of the polyether backbone. The polyether backbone is based on propylene oxide, ethylene oxide or mixed propylene oxide/ethylene oxide.

Quaternary polyoxyalkylene ammonium salts for example, are useful as ionic liquid or a precursor of an ionic liquid of the present invention of the present invention is ETHOQUAD ^TM C / 25 is ^{_{C 12 H 25 N + (CH}} 3) [(CH 2 CH 2 O _{) m H] [(CH 2} CH 2 O) n H] - Cl (m + n = 15) and ETHOQUAD ^TM 18/25 is ^{_{C 18 H 37 n + (CH}} 3) [(CH 2 CH 2 O) m include Cl (m + n = 15) ( both Illinois available from Akzo Nobel surface chemistry El elssi of ^{_{Chicago,) - H] [(CH 2}} CH 2 O) n H]. _{C 12} H ₂₅ N ⁺ (CH ₃ )[(CH ₂ CH ₂ O) _m H][(CH ₂ ) derived from the reaction of ETHOMEEN ^TM C/15 (available from Akzo Nobel Surface Chemistry LLC) with dimethylsulfate ^{_{CH 2 O) n H] -}} OSO 3 CH 3 (m + n = 5) may also be a useful ionic liquids and, other precursors of the ionic liquid of the present invention of the present invention.

Further examples include ionic liquids with polyoxyalkylene moieties:

Specific examples, the following cations:

Including, organic or fluoroorganic anions (preferably, alkane sulfonate, aryl sulfonate, alkaryl sulfonate, perfluoroalkanesulfonate, bis(perfluoroalkanesulfonyl)imide and tris( Perfluoroalkanesulfonyl)methide, more preferably alkane sulfonate, perfluoroalkanesulfonate and bis(perfluoroalkanesulfonyl)imide, most preferably perfluoroalkanesulfonate and bis( Particularly preferred are ionic liquids having a polyoxyalkylene moiety having an anion selected from the group consisting of perfluoroalkanesulfonyl) imides:

Specific examples of ionic liquids include the following, which are cations containing imide anions:

However, an ionic liquid suitable for this adhesive system should be selected by finding a balance of the properties of the cations and anions that make up the ionic liquid to achieve solubility in a particular adhesive composition after curing.

The ionic liquid may be contained in an amount of 0.1 parts by weight to 10 parts by weight, for example, 0.5 parts by weight to 5 parts by weight, 0.5 parts by weight to 2.5 parts by weight, based on 100 parts by weight of the (meth)acrylic copolymer. In the above range, it is possible to bring about a change in modulus of the adhesive film at 70°C.

The pressure-sensitive adhesive composition may further include a silane coupling agent.

The silane coupling agent can increase the adhesion of the adhesive film to an adherend such as glass. The silane coupling agent may include a conventional silane coupling agent known to those skilled in the art. For example, the silane coupling agent is 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclo Silicon compounds having an epoxy structure such as hexyl)ethyltrimethoxysilane; Polymerizable unsaturated group-containing silicon compounds such as vinyl trimethoxysilane, vinyl triethoxysilane, and (meth)acryloxypropyl trimethoxysilane; 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyl Amino group-containing silicon compounds such as dimethoxysilane; And at least one selected from the group consisting of 3-chloropropyl trimethoxysilane, and the like, but is not limited thereto.

The silane coupling agent may be included in an amount of 0.01 parts by weight to 5 parts by weight, specifically 0.02 parts by weight to 1 part by weight, based on 100 parts by weight of the (meth)acrylic copolymer. Within the above range, durability reliability can also be secured with excellent adhesion performance.

The pressure-sensitive adhesive composition may further include conventional additives such as antioxidants, UV absorbers, and plasticizers. The additive may be included in an amount of 0.01 parts by weight to 10 parts by weight based on 100 parts by weight of the (meth)acrylic copolymer. In the above range, it is possible to produce an additive effect without affecting the above effect of the adhesive film.

The pressure-sensitive adhesive composition may have a viscosity of 500 cPs to 2,500 cPs at 25°C. In the above range, it is possible to easily adjust the thickness of the adhesive film, there is no stain on the adhesive film, and the coating surface may have a uniform effect.

The adhesive film may be prepared by coating an adhesive composition to a predetermined thickness and aging at 20°C to 30°C.

The adhesive film may have a modulus of 1 x 10 ⁵ Pa or more, for example, 1 x 10 ⁵ Pa to 1 x 10 ⁶ Pa at 25°C. In the above range, even if the modulus of the pressure-sensitive adhesive film is lowered at high temperature or high temperature and high humidity, durability reliability may be high.

The adhesive film may have a modulus at 70° C. of 0.5 x 10 ⁵ Pa or more, for example, 0.5 x 10 ⁵ Pa to 1 x 10 ⁶ Pa. In the above range, even if the modulus of the pressure-sensitive adhesive film is lowered at high temperature or high temperature and high humidity, durability reliability may be high.

The adhesive film may have a modulus of 0.2 x 10 ⁵ Pa or more at 100°C, for example, 0.2 x 10 ⁵ Pa to 1 x 10 ⁶ Pa. In the above range, since the adhesive film has high modulus at high temperature or high temperature and high humidity, durability reliability is high, and panel warpage can be improved at high temperature or high temperature and high humidity.

The adhesive film may have a thickness of 3 μm to 50 μm, for example 5 μm to 30 μm. It can be used for a polarizing plate in the above range.

The polarizing plate of the present invention may include the adhesive film for the polarizing plate of the present invention. In one embodiment, the polarizing plate may include a polarizing film, an adhesive film for a polarizing plate of the present invention formed on at least one surface of the polarizing film. Accordingly, the polarizing plate may improve panel warpage at high temperature or high temperature and high humidity, and may have excellent durability reliability at high temperature or high temperature and high humidity.

The polarizing film may include a polarizer alone or a protective layer formed on at least one surface of the polarizer.

The polarizer can polarize external or internal light. The polarizer may include a polyvinyl alcohol-based polarizer dyed with iodine or the like on a polyvinyl alcohol-based film. For example, a polyvinyl alcohol polarizer is manufactured by dyeing iodine or a dichroic dye on a polyvinyl alcohol film and stretching it in a predetermined direction. Specifically, it is manufactured through a swelling process, a dyeing step, and a stretching step. How to carry out each step is commonly known to those skilled in the art. The polarizer may have a thickness of 5 μm to 50 μm. It can be used for a polarizing plate in the above range.

The protective layer may include one or more of optically transparent, protective film or protective coating layer. The protective film includes a cellulose ester resin including triacetylcellulose, a cyclic polyolefin resin including a cyclic olefin polymer (COP), a polycarbonate resin, polyethylene terephthalate (PET), etc. Polyacrylate resins including polyester resins, polyethersulfone resins, polysulfone resins, polyamide resins, polyimide resins, non-cyclic-polyolefin resins, polymethyl methacrylate resins, etc. It may be a resin film including at least one of a polyvinyl alcohol-based resin, a polyvinyl chloride-based resin, and a polyvinylidene chloride-based resin. The protective coating layer may be formed of an active energy ray-curable resin composition containing an epoxy compound, a (meth)acrylic radical polymerizable compound, or may be a liquid crystal layer.

The protective layer may have a thickness of 5 μm to 200 μm, specifically, 30 μm to 120 μm, in the case of a protective film type, 50 μm to 100 μm, and in the case of a protective coating layer type, it may be 5 μm to 50 μm. In the above range, it can be used for a light emitting display device.

An optical display device according to an exemplary embodiment of the present invention may include a polarizing plate according to exemplary embodiments of the present invention. For example, the optical display device may include a liquid crystal display device, an organic light emitting display device, and the like, but is not limited thereto.

Hereinafter, the configuration and operation of the present invention will be described in more detail through preferred embodiments of the present invention. However, this has been presented as a preferred example of the present invention and cannot be construed as limiting the present invention in any sense.

Manufacturing example

A monomer mixture containing 99 parts by weight of n-butyl acrylate (BA) and 1 part by weight of 2-hydroxyethyl methacrylate (2-HEMA) in a 1 L reactor equipped with a cooling device so that nitrogen gas is refluxed and temperature control is easy 100 parts by weight were prepared. To the monomer mixture, 60 parts by weight of ethyl acetate and 25 parts by weight of methyl ethyl ketone were added as solvents. The monomer mixture was purged with nitrogen at 65° C. for 30 minutes, and 0.04 parts by weight of azobisisobutyronitrile (AIBN) as a reaction initiator was diluted and added to 2 parts by weight of ethyl acetate. The temperature of the reactor was maintained at 65° C., reacted for 6 hours, and further reacted at 70° C. for 2 hours. After completion of the reaction, 130 parts by weight of ethyl acetate was added to prepare a methacrylic copolymer solution.

The methacrylic copolymer may have a weight average molecular weight of 1.5 million g/mol, a glass transition temperature of -30°C, and an acid value of 0.5 mg KOH/g.

Specific specifications of the components used in the following Examples and Comparative Examples are as follows.

①(meth)acrylic copolymer: methacrylic copolymer of Preparation Example

② Hardener: Toluene diisocyanate trimethylolpropane adduct (Colonate L, Nippon Urethane)

③Tackifying resin: YS polyester (Yashara, terpenephenol oligomer, molecular weight 8000g/mol ~ 20000g/mol, softening point: 145℃)

④Ionic liquid: FC4400(3M, melting point:27.5℃, [(nC ₄ H ₉ ) ₃ (CH ₃ )N] ⁺ -[N(SO ₂ CF ₃ ) ₂ ] ^- , tri-n-butylmethylammonium bis (Trifluoromethanesulfonyl)imide)

Example One

A pressure-sensitive adhesive composition was prepared by mixing ① (meth)acrylic copolymer, ② hardener, ③ tackifying resin, and ④ ionic liquid in the amounts shown in Table 1 below.

Example 2 and Comparative example 1 to Comparative example 2

In Example 1, a pressure-sensitive adhesive composition was prepared in the same manner as in Example 1, except that the content of ① (meth)acrylic copolymer, ② hardener, ③ adhesive imparting resin, and ④ ionic liquid were changed to the contents of Table 1 below.

For the pressure-sensitive adhesive compositions of Examples and Comparative Examples, the physical properties of Table 1 were evaluated, and the results are shown in Table 1 below.

(1) Storage Modulus (Pa): A pressure-sensitive adhesive is coated on a release film (eg, a polyethylene terephthalate film) and aged at 35° C. and a relative humidity of 45% to prepare an adhesive layer for a polarizing plate with a thickness of 20 μm to 25 μm. A specimen of an adhesive film for a polarizing plate having a thickness of 600 µm to 650 µm was made in layers, sampled on an 8 mm disk, and measured at 25° C. to 120° C. and 1 Hz using a rheometer (Physica MCR501, Anton Parr), and 25 The modulus at °C, 70°C, and 100°C was determined.

(2) tanδ: Modulus was calculated in the same manner as in (1). The minimum value of tan δ is described in the range of 25 to 100°C. In Example 1 and Example 2, the minimum tanδ value was obtained at 70°C.

(3) Durability: A polyvinyl alcohol film was stretched three times at 60° C., adsorbed iodine, and then stretched 2.5 times in a boric acid aqueous solution at 40° C. to prepare a polarizer (thickness: 23 μm).

A triacetylcellulose film (KC2UAW, Konica Minolta Opto, Inc., thickness: 40 μm) was adhered to one side of the polarizer with an epoxy-based UV adhesive for a polarizing plate as a protective layer. A triacetylcellulose film (KC2UAW, Konica Minolta Opto, Inc., thickness: 1 μm) was adhered to the other side of the polarizer with an epoxy-based UV adhesive for a polarizing plate.

The pressure-sensitive adhesive compositions of Examples and Comparative Examples were applied to one surface of the triacetylcellulose film to a predetermined thickness, dried at 90° C. for 4 minutes, and aged at room temperature for 1 hour to form an adhesive film having a thickness of 20 μm.

The polarizing plate on which the adhesive film was formed was cut into length x width (100mm x 75mm), laminated on a glass substrate, and a pressure of 4kg to 5kg was applied to prepare a specimen. The specimen was allowed to stand at 85° C. for 500 hours and then again at 25° C. for 1 hour, and heat resistance was evaluated with a visual or microscope according to the following criteria. In addition, the specimen was allowed to stand at 65° C. and 95% relative humidity for 500 hours, then again at 25° C. for 1 hour, and the heat and moisture resistance durability was evaluated by visual or microscope according to the following criteria.

○: No air bubbles or peeling phenomenon.

△: There are some bubbles or peeling phenomenon.

X: There are many bubbles and peeling phenomenon.

(4) Panel bending: The polarizing plates prepared in Examples and Comparative Examples were cut in width x length (400 mm x 250 mm) with a Thompson Carter to prepare a polarizing plate sample. 2 is a point for measuring warpage in a sample in an experimental example. Referring to FIG. 2, the prepared polarizing plate sample was laminated to a 0.5 mm-thick glass plate to prepare a warpage measurement sample. After leaving the warpage measurement sample at 85℃ for 100 hours, slowly cool it at room temperature for more than 1 hour, fix the height of 9 points (① to ⑨) in Fig. 2 on the stone table, measure the vernier caliper and measure the height of each position from the stone table. Was obtained. Panel warpage was described as the average value of all 9 points.

division Example 1 Example 2 Comparative Example 1 Comparative Example 2 (Meth)acrylic copolymer
(Part by weight) 100 100 100 100 Hardener (parts by weight) 10 One 10 10 Ionic liquid (parts by weight) 2 0.5 - 2 Tackifier resin
(Part by weight) 10 10 10 - Modulus
(x 10 ⁴ Pa) @25℃ 14.1 10 14.5 8.6 @70℃ 10.5 5.9 10.1 5.7 @100℃ 7.1 2.8 8.1 5.4 Value of Equation 1
(Pa/℃) 333 122 -311 -544 tan δ 0.12 0.13 0.22 0.25 durability @85℃ ○ ○ ○ ○ @65℃ and 95% relative humidity ○ ○ ○ ○ Panel deflection (mm) 0.9 One 2 2.2

As can be seen from the results of Table 1, in the case of the composition of the present invention, it was confirmed that the composition of the present invention not only exhibited an excellent panel bending effect, but also had excellent durability.

In particular, compared to Comparative Example 1 not containing an ionic liquid, Example 1 reduced the panel warpage value by 55%, and the panel warpage value was reduced by 59% compared to Comparative Example 2 without the tackifier resin, resulting in panel warpage. The effect was great.

In addition, it can be seen that the modulus of Example 1 was sharply decreased at 70° C. compared to Comparative Example 1 that did not contain an ionic liquid.

Simple modifications or changes of the present invention can be easily implemented by those of ordinary skill in the art, and all such modifications or changes can be considered to be included in the scope of the present invention.

Claims (15)

A polarizing plate formed of a pressure-sensitive adhesive composition for a polarizing plate comprising 100 parts by weight of a (meth)acrylic copolymer, 1 part by weight to 20 parts by weight of a curing agent, 10 parts by weight to 50 parts by weight of a tackifier resin, and 0.1 parts by weight to 10 parts by weight of an ionic liquid It is an adhesive film for,
The adhesive film for a polarizing plate has a value of 100Pa/°C or higher in the following formula 1,
<Equation 1>
||G'(70)-G'(100)|/(100℃-70℃)| -||G'(25)-G'(70)|/(70℃-25℃)|
(In Equation 1, G'(25) is the modulus at 25° C. of the adhesive film for a polarizing plate (unit: Pa),
G'(70) is the modulus of the adhesive film for the polarizing plate at 70°C (unit: Pa),
G'(100) is the modulus of the adhesive film for the polarizing plate at 100°C (unit: Pa)),
The tackifying resin has a softening point of 50° C. or higher,
The ionic liquid is a melting point of 25 ℃ to 35 ℃, the adhesive film for a polarizing plate.
The adhesive film for a polarizing plate according to claim 1, wherein in Equation 1, |G'(70)-G'(100)| is more than 2.0 x 10 ^{4 Pa.}
The adhesive film for a polarizing plate according to claim 1, wherein the adhesive film for a polarizing plate has a modulus of 1 x 10 ⁵ Pa or more at 25°C.
The pressure-sensitive adhesive film for a polarizing plate according to claim 1, wherein the pressure-sensitive adhesive film has a minimum value of tanδ in the range of 25°C to 100°C at 65°C to 85°C.
The pressure-sensitive adhesive film for a polarizing plate according to claim 4, wherein the minimum value of tan δ is 0.10 to 0.20.
The adhesive film for a polarizing plate according to claim 1, wherein the (meth)acrylic copolymer has a weight average molecular weight (Mw) of 1.5 million to 3 million, and a glass transition temperature of -30°C or less.
The pressure-sensitive adhesive film for a polarizing plate according to claim 1, wherein the (meth)acrylic-based copolymer is a (meth)acrylic-based copolymer having a hydroxyl group, and the curing agent includes an isocyanate-based curing agent.
The adhesive film of claim 1, wherein the tackifying resin has a weight average molecular weight of 2,000g/mol to 20,000g/mol.
The adhesive film for a polarizing plate according to claim 1, wherein the tackifying resin comprises a non-hydrogenated oligomer.
The adhesive film for a polarizing plate according to claim 1, wherein the tackifying resin comprises at least one oligomer of terpene phenol-based, styrene-based, and rosin-based.
delete delete delete A polarizing plate comprising the adhesive film for a polarizing plate according to any one of claims 1 to 10.
An optical display device comprising the polarizing plate of claim 14.

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