KR101270218B1 - Adhesive compositions and optical films using the same - Google Patents

Abstract

The present invention provides an adhesive film comprising a compound having an azetidinium functional group and a silane compound having an epoxy functional group, and an optical film and a polarizing plate including the adhesive layer formed using the same.

Adhesive, Optical Film

Description

Adhesive composition and optical film using same {ADHESIVE COMPOSITIONS AND OPTICAL FILMS USING THE SAME}

The present invention provides an adhesive composition and an optical film using the same. Specifically, the present invention provides an adhesive composition and an optical film using the same, which can be usefully used for an optical film having excellent adhesion and requiring transparency.

The polarizing plate generally has a structure in which a triacetyl cellulose (TAC) film is laminated on both surfaces of a polarizer (polarizing film) of polyvinyl alcohol (PVA) component with an aqueous adhesive made of a PVA-based aqueous solution (FIG. 1). When the polarizing plate having such a structure is applied to the liquid crystal display device in the IPS (In-Plane Switching) mode without a compensation film, the viewing angle characteristic is weak. Therefore, one of two conventional TAC films used in the thickness direction and in-plane ( It is also used to improve the viewing angle by replacing the Zero Retardation TAC (TA-TAC) film with little retardation in-plane.

However, Z-TAC basically causes the durability problem due to dimensional change in long-term use due to the vulnerability to moisture of TAC film. In order to compensate for this disadvantage, attempts have been made to apply a film of a composition having high resistance to moisture and low retardation properties, such as cyclo olefin (Cyclic Olefin) resin or acrylic resin. In particular, it is known that an acrylic film may have advantages in terms of cost as well as optical properties and durability.

When manufacturing a polarizing plate using a TAC film as a protective film, an aqueous PVA adhesive has been mainly used for adhesion | attachment with the polarizer of a PVA component. At this time, the TAC film surface is subjected to alkali treatment or corona treatment to improve adhesion. However, when the acrylic film and the water-based PVA adhesive are used in the production of the polarizing plate, it is difficult to easily secure the adhesive force by alkali treatment or corona treatment. In the case of conventional TAC film, the hydrophilic group such as hydroxy group is introduced to the surface of the film through alkali treatment or corona treatment, and the adhesive force is easily secured through hydrogen bonding with PVA-based adhesive, but acrylic film is corona treated. Alternatively, the amount of hydrophilic groups introduced even by plasma treatment is small, and the hydrogen bonding with the PVA-based adhesive is insufficient, and sufficient adhesion between the acrylic film and the polarizer of the PVA component is not secured.

An acrylic UV curable adhesive may be used to attach the acrylic film and the polarizer, but some problems have been identified as follows. (1) Since a water-based adhesive is used in a general polarizing plate manufacturing process, when using a UV-curable adhesive, a separate UV curing process is required, and an explosion-proof equipment is additionally required by using a volatile flammable monomer, and (2) existing water-based PVA adhesives While the adhesive thickness can be thinned to about 100 nm through solid content control and process control, the acrylic UV curable adhesive is generally difficult to control the thickness of the adhesive layer to 1 mm or less, and thus the polarizing plate is broken due to the increase in brittleness of the adhesive layer. Problems may occur, and (3) adhesion with the acrylic film side is easy, but securing the adhesive force with the polarizer side is not easy. Although a large amount of acidic reactors are included in order to secure adhesion with the polarizer, it is not preferable in terms of acid corrosion and working environment.

Therefore, in order to manufacture a polarizing plate using an acrylic film as a polarizer protective film, the application of a water-based adhesive, which is relatively easy to provide an existing process and stable polarizing plate properties, has a relatively large number of advantages. Accordingly, development of a water-based adhesive suitable for an optical film including a polarizing plate is required.

The present invention is an adhesive composition which is excellent in adhesiveness and does not inhibit the optical properties and durability of the optical film when applied to the optical film, and particularly, when the acrylic film is used as the polarizer protective film, it gives excellent adhesion with the polarizer and is produced as a result. It is an object of the present invention to provide an adhesive composition which does not impair optical properties and durability of the polarizing plate. In addition, an object of the present invention is to provide an optical film and a polarizing plate produced using the adhesive composition.

In order to achieve the above object, the present invention provides an adhesive composition comprising a compound having an azetidinium functional group and a silane compound having an epoxy functional group.

In addition, the present invention after the addition of a compound having an azetidinium functional group, polyvinyl alcohol-based resin and a basic compound, and then stirring for 3 to 24 hours at a temperature of 60 to 90 ℃ and a silane compound having an epoxy functional group It provides a method for producing an adhesive composition comprising the step of injecting.

In addition, the present invention is an optical film having a structure in which two or more films are laminated, using an adhesive composition comprising a compound having an azetidinium functional group and at least one interface between the films and a silane-based compound having an epoxy functional group. Provided is an optical film characterized in that the adhesive layer formed is provided.

In addition, the present invention is a polarizing plate having a structure in which a first film, a polarizer and a second film are sequentially laminated, the compound and epoxy having an azetidinium functional group between at least one of the first film and the second film and the polarizer The adhesive layer formed using the adhesive composition containing the silane type compound which has a functional group is provided, The polarizing plate characterized by the above-mentioned.

In addition, the present invention provides an electronic device comprising the optical film or the polarizing plate.

The adhesive composition according to the present invention is excellent in adhesiveness, and can be applied to an existing optical film process of a laminated structure without any additional process or equipment as it is without impairing the transparency of the optical film, and thus can be usefully used for the manufacture of an optical film. have. In addition, the optical film including the adhesive layer prepared using the adhesive composition according to the present invention is excellent in durability. In particular, the adhesive composition according to the present invention provides excellent adhesion with the polarizer when the acrylic film is used as a polarizer protective film and does not impair the optical properties and durability of the resulting polarizing plate.

The optical film according to the present invention is characterized in that it comprises an adhesive layer formed by using an adhesive composition comprising a compound having an azetidinium functional group and a silane compound having an epoxy functional group.

The compound having an azetidinium functional group can react with a functional group such as a carboxyl group on the surface of the optical film, and has a positive (+) charge so that the azetidinium functional group has a hydrophilic group or a corona treatment or plasma treatment. The wettability to an optical film rich in negative (-) charges on the film surface is excellent. In addition, the azetidinium functional group may be opened to form a hydrophilic group, and the hydrophilic group may be hydrogen-bonded with a hydroxyl group on the surface of an optical film such as a polarizer. In this regard, the compound having an azetidinium functional group may further include a hydrophilic group such as a hydroxy group, a carboxyl group, an amine group, and an amide group in addition to the azetidinium functional group. For this reason, a compound having an azetidinium functional group can provide excellent adhesion as compared to conventional adhesives such as PVA-based adhesives. In addition, since the compound having the azetidinium functional group can self-crosslink in the adhesive layer, thereby improving the water resistance of the adhesive layer, optical films including the polarizing plate using the same have improved durability, and the film between films in harsh environments. Peeling can be prevented.

As the compound having an azetidinium functional group, a compound of Formula 1 may be used:

In Formula 1,

X and Y are aliphatic hydrocarbon groups, at least one of X and Y is an aliphatic hydrocarbon group including at least one of an amine group, an amide group, and a ketone group, and X and Y may be linked to each other to form a ring,

R1 to R6 are each selected from the group consisting of hydrogen, a hydroxyl group, a C ₁ to C ₂₀ aliphatic hydrocarbon group, an alkylcarboxylic acid ester group and a cyan group,

A ^- is a monovalent anion,

n is 30 to 7,000.

At least one of X and Y preferably includes a hydrophilic group. It is preferable that the compound of Formula 1 has a weight average molecular weight of 10,000 to 2 million.

The compound of Formula 1 includes a compound of Formula 2 below.

In Formula 2,

X ', X "and Y' are each C ₁ to C ₂₀ aliphatic hydrocarbon group,

R1 to R6 are each selected from the group consisting of hydrogen, a hydroxyl group, a C ₁ to C ₂₀ aliphatic hydrocarbon group, an alkylcarboxylic acid ester group and a cyan group,

A ^- is a monovalent anion,

n is 30 to 7,000.

The compound of Formula 2 includes polyaminoamide-Epichlorohydrin (PAE) of Formula 3 below.

In Chemical Formula 3, n is 30 to 7,000.

The adhesive composition according to the present invention may further include a solvent such as water to form an adhesive layer. At this time, the concentration of the compound having the azetidinium (azetidinium) functional group is preferably 0.1 to 30% by weight, preferably 0.5 to 10% by weight.

The silane compound having the epoxy functional group can improve the adhesion with an optical film such as a polyvinyl alcohol polarizer or a TAC film. As the silane compound having the epoxy functional group, a compound of Formula 4 may be used.

In Formula 4,

R7 to R9 are methyl group or methoxy, ethoxy simultaneously or independently of each other,

X is an alkyl group of C ₁ to C _5.

Specific examples of the silane compound having an epoxy functional group include beta- (3,4-epoxycyclohexyl) -ethyltmethoxy silane, 3-glycidoxy propylmethyldiethoxysilane, 3-glycidoxy propyltrimethoxysilane Etc., but is not necessarily limited thereto.

The silane-based compound having the epoxy functional group is preferably included in 1% by weight or more, more preferably in 1 to 5% by weight based on the total weight of the adhesive composition. When the content is less than 1% by weight, the adhesive strength of the adhesive composition may be lowered.

The adhesive composition according to the invention preferably has a pH of 2 to 11, more preferably 4 to 10. When the pH is less than 2, the adhesion may be reduced, and when the pH is greater than 11, the polarizing plate may be degraded in optical properties. Adhesive composition according to the present invention can be adjusted pH using a method such as adding a basic compound. A basic compound is not specifically limited, but preferred examples may include NaOH, KOH, NH ₄ OH.

The adhesive composition according to the present invention may further include a polyvinyl alcohol (PVA) -based resin. By further including a polyvinyl alcohol-based resin, the adhesion with an optical film such as a polyvinyl alcohol polarizer or a TAC film can be further improved. In particular, the use of modified PVA containing an acetoacetyl group or the like is advantageous for adhesiveness and crosslinking with a compound having the azetidinium functional group. As a specific example, Japan Synthetic Chemicals Gohsefimer (trade name) Z-100, Z-200, Z-200H, Z-210, Z-220, Z-320 and the like can be used, but are not limited thereto. At this time, the weight ratio of the polyvinyl alcohol-based resin is not particularly limited, and its range may vary slightly depending on the type of the film to be bonded. For example, when adhering a polyvinyl alcohol polarizer and an acrylic film, it is preferable to use 10 weight part or more and 1,000 weight part or less with respect to 100 weight part of compounds which have an azetidinium functional group. When the polyvinyl alcohol-based resin is less than 10 parts by weight, the adhesive strength with the polyvinyl alcohol polarizing element or TAC film is poor, and when it exceeds 1,000 parts by weight, there is a problem that the adhesive strength with the acrylic film is poor.

In addition, the adhesive composition according to the present invention preferably has a viscosity of 6 to 20 cP, more preferably 9 to 13 cP. When the viscosity is less than 9, the flow of the adhesive composition may occur and the thickness of the final adhesive layer may be thin, and when it exceeds 20 cP, staining may occur due to drying delay when laminating the polarizer.

In the adhesive composition according to the present invention, it is preferable that the change over time of the viscosity and pH over 7 days is less than 5%. When the viscosity and pH change of 5 days or more of the adhesive composition is 5% or more, it is difficult to obtain a desired thickness and adhesive strength of the adhesive layer.

In addition, the present invention after the addition of a compound having an azetidinium functional group, polyvinyl alcohol-based resin and a basic compound, and then stirring for 3 to 24 hours at a temperature of 60 to 90 ℃ and a silane compound having an epoxy functional group It provides a method for producing an adhesive composition comprising the step of injecting.

The present invention also provides an optical film having a structure in which two or more films are laminated, using an adhesive composition comprising a compound having an azetidinium functional group and at least one interface between the films and a silane compound having an epoxy functional group. It provides an optical film, characterized in that provided with an adhesive layer formed. In the present invention, the optical film collectively refers to a film that performs an optical function, and if the film is a film for performing a specific optical function such as a polarizing plate as well as a narrow transparent film having a light transmittance of 80% or more, the light transmittance is 50% or less. It also includes an optical film.

The film to be laminated is not particularly limited, but an acrylic film, a PET film, in particular, an acrylic primer-treated PET film, a TAC film, a COP film, a PC (polycarbonate) film, a PNB (polynorbornene) film, or the like may be used. In particular, in the case of an acrylic film and an acrylic primer-treated PET film, the adhesive force is further improved as compared with the case of using a conventional polyvinyl alcohol-based adhesive. The laminated films may be made of the same or different materials.

The laminated films may be surface treated to improve adhesion if necessary. For example, alkali treatment, corona treatment, plasma treatment, primer treatment, and the like can be made.

The present invention also relates to a polarizing plate having a structure in which a first film, a polarizer and a second film are sequentially stacked, wherein at least one of the first film and the second film and a compound having an azetidinium functional group between the polarizer and an epoxy functional group Provided is an adhesive layer formed using an adhesive composition comprising a silane compound having a polarizing plate. At this time, the first film or the second film may also be subjected to the surface treatment as described above.

As the first film and the second film, an acrylic film, a PET film, especially an acrylic primer-treated PET film, a TAC film, a COP film, a PC (polycarbonate) film, a PNB (polynorbornene) film, or the like may be used. have. The first film and the second film may be made of the same material, or may be made of different materials. For example, both the first film and the second film may be an acrylic film or a TAC film (FIG. 2), either one may be an acrylic film and the other may be a TAC film (FIG. 3).

The adhesive layer is formed by using the adhesive composition according to the present invention described above, specifically, the adhesive composition is applied directly onto a film and dried, or the adhesive composition is applied between two or more films and pressed using a compression roll. And then dried. The thickness of the adhesive layer is preferably 10 nm to 500 nm, more preferably 20 nm to 200 nm.

The polarizing plate according to the present invention preferably has a light transmittance of 35 to 45% and a polarization degree of 98 or more.

As described above, the optical article such as the optical film and the polarizing plate according to the present invention can maintain excellent optical properties without deteriorating the light transmittance of the manufactured optical article due to the excellent light transmittance of the adhesive composition containing a compound having an azetidinium functional group. And it can improve the durability of the optical article manufactured with excellent adhesion.

In particular, when applied to a polarizing plate, the optical properties of the polarizer by the adhesive composition, such as transmittance, polarization degree, color, etc. are almost the same as when using a conventional polyvinyl alcohol-based adhesive, so that the production line without changing the process conditions There is an advantage that can be applied alternatively.

The present invention provides an electronic device comprising the optical film or the polarizing plate. Examples of the electronic device include a liquid crystal display device and the like, but the electronic device is not particularly limited as long as it requires the optical film or the polarizing plate. The electronic device has a configuration known in the art except that it includes an adhesive layer formed using the adhesive composition according to the present invention described above. For example, the electronic device may be a liquid crystal display device including a liquid crystal cell, a polarizing plate according to the present invention provided on both sides of the liquid crystal cell, and a backlight unit.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the following examples are intended to illustrate the invention, whereby the scope of the invention is not limited.

Example

Example 1

11 g of Kymene-557H (Hercules Korea, 12.5 wt%), 25 g of modified polyvinyl alcohol resin Gohsefimer Z-200 (Japan Synthetic Chemical), and 2.5 wt% NaOH aqueous solution 1 were added in order to obtain a pH of 7, followed by a temperature of 60 ° C. The mixture was stirred for 24 hours. Thereafter, 0.37 g of Z-6040 (manufactured by Dow corning) was added as a silane compound having an epoxy functional group to prepare an adhesive composition.

The adhesive composition was then injected between one side of the polarizer and the N resin composition corona-treated under the condition of 50 W / m ² / min between the acrylic film drawn in the TD direction, and the other side of the polarizer and the alkali pretreated TAC film. Then, after laminating using a laminator, dried for 5 minutes by hot air to prepare a polarizing plate.

Comparative Example 1

11 g of Kymene-557H (Hercules Korea, 12.5 wt%), 25 g of modified polyvinyl alcohol resin Gohsefimer Z-200 (Japan Synthetic Chemical), and then 1 g of 2.5 wt% NaOH aqueous solution so that the pH is 7 The mixture was stirred for 24 hours to prepare an adhesive composition.

The adhesive composition was then injected between one side of the polarizer and the N resin composition corona-treated under the condition of 50 W / m ² / min between the acrylic film drawn in the TD direction, and the other side of the polarizer and the alkali pretreated TAC film. Then, after laminating using a laminator, dried for 5 minutes by hot air to prepare a polarizing plate.

Assessment Methods

1. Adhesion

After peeling the surface of the polarizing plates prepared in Example 1 and Comparative Example 1 using a cutter blade, the degree of peeling around the sheath was shown as a percentage (FIG. 4). The lower the value, the better the adhesion.

2. Peeling force

The peeling force of the polarizers prepared in Example 1 and Comparative Example 1 was measured using a 90 degree peel measurement mode of the texture analyzer.

3. Water resistance

After attaching one side of the polarizing plates prepared in Example 1 and Comparative Example 1 to the glass plate using the pressure-sensitive adhesive, and left in an immersed in a thermostatic chamber of 60 ℃ temperature 4 hours and 48 hours after the shrinkage of the polarizer and the protective film Water resistance was evaluated by peeling.

Evaluation results

Protective film Adhesive force (sheath peeling)
Water resistance Peel force [N]
2cm in width Water resistance
60 degrees Stretched N TAC cotton Stretched N TAC cotton 4 hours Example 1 A / TAC 100% none 1.5 3 none Comparative Example 1 A / TAC none none 0.3 3 none

* A: acrylic film

1 illustrates a conventional polarizing plate structure.

2 illustrates a structure of a polarizing plate according to an example of the present invention.

3 illustrates a structure of a polarizing plate according to an example of the present invention.

4 is a photograph showing a sheath peeling evaluation method for evaluating the adhesive force.

Claims (31)

An adhesive composition comprising a compound having an azetidinium functional group represented by Formula 1 and a silane compound having an epoxy functional group: [Formula 1]

In Formula 1, X and Y are aliphatic hydrocarbon groups, at least one of X and Y is an aliphatic hydrocarbon group including at least one of an amine group, an amide group, and a ketone group, and X and Y may be linked to each other to form a ring, R1 to R6 are each selected from the group consisting of hydrogen, a hydroxyl group, a C ₁ to C ₂₀ aliphatic hydrocarbon group, an alkylcarboxylic acid ester group and a cyan group, A ^- is a monovalent anion, n is 30 to 7,000. The adhesive composition of claim 1, wherein the compound of Formula 1 is a compound of Formula 2: [Formula 2]

In Formula 2, X ', X "and Y' are each C ₁ to C ₂₀ aliphatic hydrocarbon group, R1 to R6 are each selected from the group consisting of hydrogen, a hydroxyl group, a C ₁ to C ₂₀ aliphatic hydrocarbon group, an alkylcarboxylic acid ester group and a cyan group, A ^- is a monovalent anion, n is 30 to 7,000. The adhesive composition of claim 2, wherein the compound of Formula 2 is a compound of Formula 3: (3)

In Chemical Formula 3, n is 30 to 7,000. The adhesive composition of claim 1, wherein the silane compound having an epoxy functional group is a compound of Formula 4 below: [Formula 4]

In Formula 4, R7 to R9 are methyl group or methoxy, ethoxy simultaneously or independently of each other, X is an alkyl group of C ₁ to C _5. The method of claim 1, wherein the silane compound having an epoxy functional group is a beta- (3,4-epoxycyclohexyl) -ethyl methoxy silane, 3-glycidoxy propylmethyl diethoxysilane and 3-glycidoxy propyltrimeth Adhesive composition of at least one selected from the group consisting of oxysilane. The adhesive composition according to claim 1, wherein the silane compound having an epoxy functional group is included in an amount of 1% by weight or more based on the total weight of the adhesive composition. The adhesive composition of claim 1, wherein the adhesive composition has a pH of 4 to 10. The adhesive composition of claim 1, wherein the adhesive composition further comprises a basic compound. The adhesive composition of claim 1, wherein the adhesive composition further comprises a polyvinyl alcohol-based resin. The adhesive composition of claim 1, wherein the adhesive composition has a viscosity of 6 to 20 cP. The adhesive composition of claim 1, wherein the adhesive composition has a change of viscosity and pH over time for less than 5% for 7 days. And adding a compound having an azetidinium functional group, a polyvinyl alcohol-based resin, and a basic compound in sequence, followed by stirring at a temperature of 60 to 90 ° C. for 3 to 24 hours, and adding a silane compound having an epoxy functional group. Method for producing an adhesive composition, characterized in that. The method of claim 12, wherein the compound having an azetidinium functional group is a compound represented by Formula 1 below: [Formula 1]

In Formula 1, X and Y are aliphatic hydrocarbon groups, at least one of X and Y is an aliphatic hydrocarbon group including at least one of an amine group, an amide group, and a ketone group, and X and Y may be linked to each other to form a ring, R1 to R6 are each selected from the group consisting of hydrogen, a hydroxyl group, a C ₁ to C ₂₀ aliphatic hydrocarbon group, an alkylcarboxylic acid ester group and a cyan group, A ^- is a monovalent anion, n is 30 to 7,000. The method of claim 13, wherein the compound of Formula 1 is a compound of Formula 2: [Formula 2]

In Formula 2, X ', X "and Y' are each C ₁ to C ₂₀ aliphatic hydrocarbon group, R1 to R6 are each selected from the group consisting of hydrogen, a hydroxyl group, a C ₁ to C ₂₀ aliphatic hydrocarbon group, an alkylcarboxylic acid ester group and a cyan group, A ^- is a monovalent anion, n is 30 to 7,000. The method of claim 14, wherein the compound of Formula 2 is a compound of Formula 3 below: (3)

In Chemical Formula 3, n is 30 to 7,000. The method of claim 12, wherein the silane compound having an epoxy functional group is a compound of Formula 4 below: [Formula 4]

In Formula 4, R7 to R9 are methyl group or methoxy, ethoxy simultaneously or independently of each other, X is an alkyl group of C ₁ to C _5. An optical film having a structure in which two or more films are laminated, wherein an adhesive layer formed by using the adhesive composition according to any one of claims 1 to 11 is provided on at least one interface between the films. Optical film. The optical film of claim 17, wherein the compound having an azetidinium functional group is a compound represented by Formula 1 below: [Formula 1]

In Formula 1, X and Y are aliphatic hydrocarbon groups, at least one of X and Y is an aliphatic hydrocarbon group including at least one of an amine group, an amide group, and a ketone group, and X and Y may be linked to each other to form a ring, R1 to R6 are each selected from the group consisting of hydrogen, a hydroxyl group, a C ₁ to C ₂₀ aliphatic hydrocarbon group, an alkylcarboxylic acid ester group and a cyan group, A ^- is a monovalent anion, n is 30 to 7,000. The optical film of claim 18, wherein the compound of Formula 1 is a compound of Formula 2: [Formula 2]

In Formula 2, X ', X "and Y' are each C ₁ to C ₂₀ aliphatic hydrocarbon group, R1 to R6 are each selected from the group consisting of hydrogen, a hydroxyl group, a C ₁ to C ₂₀ aliphatic hydrocarbon group, an alkylcarboxylic acid ester group and a cyan group, A ^- is a monovalent anion, n is 30 to 7,000. The optical film of claim 19, wherein the compound of Formula 2 is a compound of Formula 3: (3)

In Chemical Formula 3, n is 30 to 7,000. The optical film of claim 17, wherein the silane compound having an epoxy functional group is a compound of Formula 4 below. [Formula 4]

In Formula 4, R7 to R9 are methyl group or methoxy, ethoxy simultaneously or independently of each other, X is an alkyl group of C ₁ to C _5. The method according to claim 17, wherein at least one of the film is selected from acrylic film, PET film, acrylic primer treated PET film, TAC film, COP film, PC (polycarbonate) film and PNB (polynorbornene) -based film Optical film. The optical film of claim 17, wherein at least one of the films has at least one surface treated with at least one surface selected from an alkali treatment, a corona treatment, a plasma treatment, and a primer treatment. A polarizing plate having a structure in which a first film, a polarizer and a second film are sequentially laminated, wherein the adhesive composition according to any one of claims 1 to 11 is disposed between at least one of the first film and the second film and the polarizer. The adhesive layer formed using is provided, The polarizing plate characterized by the above-mentioned. The polarizing plate of claim 24, wherein the compound having an azetidinium functional group is a compound represented by Chemical Formula 1 below: [Formula 1]

In Formula 1, X and Y are aliphatic hydrocarbon groups, at least one of X and Y is an aliphatic hydrocarbon group including at least one of an amine group, an amide group, and a ketone group, and X and Y may be linked to each other to form a ring, R1 to R6 are each selected from the group consisting of hydrogen, a hydroxyl group, a C ₁ to C ₂₀ aliphatic hydrocarbon group, an alkylcarboxylic acid ester group and a cyan group, A ^- is a monovalent anion, n is 30 to 7,000. The polarizing plate of claim 25, wherein the compound of Formula 1 is a compound of Formula 2: [Formula 2]

In Formula 2, X ', X "and Y' are each C ₁ to C ₂₀ aliphatic hydrocarbon group, R1 to R6 are each selected from the group consisting of hydrogen, a hydroxyl group, a C ₁ to C ₂₀ aliphatic hydrocarbon group, an alkyl carboxylic acid ester group and a cyan group, A ^- is a monovalent anion, n is 30 to 7,000. The polarizer of claim 26, wherein the compound of Formula 2 is a compound of Formula 3: (3)

In Chemical Formula 3, n is 30 to 7,000. The polarizing plate of claim 24, wherein the silane compound having an epoxy functional group is a compound represented by Formula 4 below: [Formula 4]

In Formula 4, R7 to R9 are methyl group or methoxy, ethoxy simultaneously or independently of each other, X is an alkyl group of C ₁ to C _5. The method according to claim 24, wherein the first or second film is selected from acrylic film, PET film, acrylic primer treated PET film, TAC film, COP film, PC (polycarbonate) film and PNB (polynorbornene) -based film The polarizing plate will be. The polarizing plate according to claim 24, wherein at least one surface of the first or second film is subjected to at least one surface treatment selected from alkali treatment, corona treatment, plasma treatment, and primer treatment. An electronic device comprising the polarizing plate of claim 24.

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