KR101285163B1 - Adhesive compositions and optical films using the same - Google Patents

Abstract

The present invention comprises an adhesive composition comprising a compound having an azetidinium functional group, a polyvinyl alcohol-based resin and a basic compound and having a change in viscosity and pH over time for less than 5% for 7 days, and an adhesive layer formed using the same. It provides an optical film and a polarizing plate.

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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 can be usefully used for an optical film having excellent storage stability, excellent adhesiveness, and requiring transparency, and provides an adhesive composition and an optical film using the same.

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 moisture vulnerability of the 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, a separate UV curing process is required when using a UV-curable adhesive, and an explosion-proof equipment is additionally required by using a volatile flammable monomer. (2) Existing water-based PVA The adhesive can be thinned to about 100 nm by adjusting the solids content and controlling the process, whereas the acrylic UV curable adhesive is generally difficult to control the thickness of the adhesive layer to 1 mm or less, resulting in increased brittleness of the adhesive layer. Problems such as breakage of the polarizing plate may occur, and (3) adhesion to the acrylic film side is easy, but securing of 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 has excellent storage stability, excellent adhesion, and does not impair the optical properties and durability of the optical film when applied to the optical film, as an adhesive composition, especially when using an acrylic film as a polarizer protective film excellent An object of the present invention is to provide an adhesive composition having excellent storage stability without imparting adhesiveness and not impairing optical properties and durability of the resulting 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, a polyvinyl alcohol-based resin, and a basic compound, wherein the change over time in viscosity and pH over 7 days is less than 5%.

In addition, the present invention is an adhesive comprising a step of sequentially injecting a compound having an azetidinium functional group, a polyvinyl alcohol-based resin and a basic compound, followed by stirring for 3 to 24 hours at a temperature of 60 to 90 ℃ Provided are methods for preparing the composition.

In addition, the present invention is prepared by a method comprising the step of sequentially adding a compound having an azetidinium functional group, a polyvinyl alcohol-based resin and a basic compound, followed by stirring at a temperature of 60 to 90 ℃ for 3 to 24 hours. It provides an adhesive composition, characterized in that.

In addition, the present invention is an optical film having a structure in which two or more films are laminated, comprising a compound having an azetidinium functional group, a polyvinyl alcohol-based resin and a basic compound at least one interface between the films and viscosity for 7 days And it provides an optical film, characterized in that the adhesive layer formed using an adhesive composition having a time-dependent change in pH is less than 5%.

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 having an azetidinium functional group between at least one of the first film and the second film and the polarizer, poly Provided is a polarizing plate comprising a vinyl alcohol-based resin and a basic compound, and having an adhesive layer formed using an adhesive composition having a change in viscosity and pH over time for less than 5% for 7 days.

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 has excellent storage stability, excellent adhesion, and can be applied as it is without additional processes or facilities to the existing laminated optical film process without impairing the transparency of the optical film. It can be usefully used for manufacturing. 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 imparts excellent adhesion with the polarizer when the acrylic film is used as a polarizer protective film and does not inhibit the optical properties and durability of the resulting polarizing plate.

The optical film according to the present invention comprises an adhesive layer formed using an adhesive composition containing an azetidinium functional group, a polyvinyl alcohol-based resin and a basic compound and having a change in viscosity and pH over time for less than 5% for 7 days. It is characterized by including.

The compound having an azetidinium functional group can react with an azetidinium functional group such as a carboxyl group on the surface of the optical film, and has a positive (+) charge, and thus has a hydrophilic group, a corona treatment, or a plasma treatment. Through this, the wettability to the optical film rich in negative (-) charge 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 basic compound may serve to adjust the pH of the adhesive composition. The basic compound may be NaOH, KOH or NH ₄ OH, etc., but is not necessarily limited thereto.

The basic compound is preferably contained in 5 to 10 parts by weight based on 100 parts by weight of the compound having an azetidinium functional group represented by the formula (1).

It is preferable that the pH of the adhesive composition according to the present invention is adjusted to 2 to 11, more preferably 4 to 10 by adding the basic compound. 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.

The polyvinyl alcohol (PVA) resin may further improve the adhesiveness with an optical film such as a polyvinyl alcohol polarizer or a TAC film. 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. If 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. If the viscosity is greater than 20 cP, staining may occur due to drying delay when laminating the polarizing plate.

In addition, the present invention is an adhesive comprising a step of sequentially injecting a compound having an azetidinium functional group, a polyvinyl alcohol-based resin and a basic compound, followed by stirring for 3 to 24 hours at a temperature of 60 to 90 ℃ Provided are methods for preparing the composition.

If the stirring temperature is less than 60 ℃ the storage stability of the adhesive composition may be lowered, the viscosity and pH of the adhesive composition may be lowered, and if it exceeds 90 ℃ may be accelerated thermal decomposition of the compound having an azetidinium functional group. .

The compound having an azetidinium functional group contains an amide group in the main chain, and has a characteristic of changing viscosity and pH as the amide group is broken under the condition of weak acid as the storage time elapses. As a result, the adhesive composition has a reduced viscosity as the storage time is cured, resulting in the flow of the adhesive composition during the manufacture of the optical film, the thickness of the final adhesive layer may be thin, and the pH decreases the adhesive strength of the prepared optical film. This can be degraded.

As described above, as the amide bond of the compound having an azetidinium functional group breaks over time, a change in viscosity and pH occurs over time. Therefore, in the preparation of the adhesive composition, by applying heat and a base to break the amide bond of the compound having an azetidinium functional group in advance, it is possible to prepare an adhesive composition having a controlled pH and a certain viscosity.

In general, when the viscosity of the adhesive composition changes by 5% or more, a thickness difference of the final adhesive occurs, and thus it is difficult to obtain a desired thickness of the adhesive layer.

In addition, the present invention is prepared by a method comprising the step of sequentially adding a compound having an azetidinium functional group, a polyvinyl alcohol-based resin and a basic compound, followed by stirring at a temperature of 60 to 90 ℃ for 3 to 24 hours. It provides an adhesive composition characterized in that.

The present invention also provides an optical film having a structure in which two or more films are laminated, wherein an optical film is formed on at least one interface between the films using an adhesive composition according to the present invention. to provide. 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%. The following optical film is also included.

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 the polarizer are formed using the adhesive composition according to the present invention. The polarizing plate provided with the adhesive bond layer is provided. 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 chemistry, 3 wt%), and 1 g of 2.5 wt% NaOH aqueous solution so that the pH is 7 To 60 ° C. and stirred for 24 hours to prepare an adhesive composition.

After injecting the adhesive composition between one side of the polarizer and the acrylic resin of N resin composition treated with corona treatment at 50 W / m ² / min and the other side of the polarizer and the alkali pretreated TAC film, After laminating, it was dried for 5 minutes with hot air to prepare a polarizing plate.

Example 2

11 g of Kymene-557H (Hercules Korea, 12.5 wt%), 25 g of modified polyvinyl alcohol resin Gohsefimer Z-200 (Japan synthetic chemistry, 3 wt%), and 1 g of 2.5 wt% NaOH aqueous solution to pH 7 The temperature was raised to 80 ° C. and stirred for 6 hours to prepare an adhesive composition.

After injecting the adhesive composition between one side of the polarizer and the acrylic resin of N resin composition treated with corona treatment at 50 W / m ² / min and the other side of the polarizer and the alkali pretreated TAC film, After laminating, it was dried for 5 minutes with hot air to prepare a polarizing plate.

Example 3

11 g of Kymene-557H (Hercules Korea, 12.5 wt%), 25 g of modified polyvinyl alcohol resin Gohsefimer Z-200 (Japan synthetic chemistry, 3 wt%), and 1 g of 2.5 wt% NaOH aqueous solution so that the pH is 7 The temperature was raised to 90 ° C. and stirred for 3 hours to prepare an adhesive composition.

After injecting the adhesive composition between one side of the polarizer and the acrylic resin of N resin composition treated with corona treatment at 50 W / m ² / min and the other side of the polarizer and the alkali pretreated TAC film, After laminating, it was dried for 5 minutes with 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 Chemistry, 3 wt%), and 1 g of 2.5 wt% NaOH aqueous solution so that the pH is 7 After stirring the temperature at 25 ℃ 0.5 hours to prepare an adhesive composition.

After injecting the adhesive composition between one side of the polarizer and the acrylic resin of N resin composition treated with corona treatment at 50 W / m ² / min and the other side of the polarizer and the alkali pretreated TAC film, After laminating, it was dried for 5 minutes with hot air to prepare a polarizing plate.

Comparative Example 2

11 g of Kymene-557H (Hercules Korea, 12.5 wt%) and 1 g of a 2.5 wt% NaOH aqueous solution were sequentially added so as to have a pH of 7, and then the temperature was stirred at 25 ° C. for 0.5 hour to prepare an adhesive composition.

After injecting the adhesive composition between one side of the polarizer and the acrylic resin of N resin composition treated with corona treatment at 50 W / m ² / min and the other side of the polarizer and the alkali pretreated TAC film, After laminating, it was dried for 5 minutes with hot air to prepare a polarizing plate.

Comparative Example 3

11 g of Kymene-557H (Hercules Korea, 12.5 wt%) was added and then heated at 80 ° C. for 6 hours. Then, 13 g of modified polyvinyl alcohol resin Gohsefimer Z-200 (Japan Synthetic Chemical, 3 wt%) and 1.5 g of 2.5 wt% NaOH aqueous solution were sequentially added so as to have a pH of 7, and then the temperature was stirred at 25 ° C. for 0.5 hour. Was prepared.

After injecting the adhesive composition between one side of the polarizer and the acrylic resin of N resin composition treated with corona treatment at 50 W / m ² / min and the other side of the polarizer and the alkali pretreated TAC film, After laminating, it was dried for 5 minutes with hot air to prepare a polarizing plate.

Assessment Methods

1. Viscosity change

The viscosity of the adhesive composition prepared according to Examples 1 to 3 and Comparative Examples 1 to 3 by using a Brookfield viscometer (Brookfield) was measured, and the viscosity was once again left at room temperature for 7 days. The amount of change thereof was measured and described in Table 1 below.

2. pH change

The pH of the adhesive composition prepared according to Examples 1 to 3 and Comparative Examples 1 to 3 by using a pH meter (meter), and after leaving for 7 days at room temperature to measure the pH once again The amount of change is shown in Table 1 below.

3. Adhesion

After peeling using a cutter blade on the surface of the polarizing plates prepared according to Examples 1 to 3 and Comparative Examples 1 to 3, the degree of peeling around the sheath was shown as a percentage (FIG. 4). The lower the value, the better the adhesion.

4. Water resistance

After attaching one side of the polarizing plates prepared according to Examples 1 to 3 and Comparative Examples 1 to 3 to the glass plate using the pressure-sensitive adhesive, it was left to be immersed in a thermostat at 60 ℃ temperature for 4 hours and 48 Water resistance was evaluated by shrinkage of the polarizer after time and peeling of the protective film.

Evaluation results

Protective film Viscosity Change
7 days later pH
7 days later Adhesion
(Sheath peeling) Water resistance
60 degrees Acrylic cotton TAC cotton After 4hr Example 1 A / TAC Within 5% Within 5% none none No peeling Example 2 A / TAC Within 5% Within 5% none none No peeling Example 3 A / TAC Within 5% Within 5% none none No peeling Comparative Example 1 A / TAC 30% or more 15% or more none none No peeling Comparative Example 2 A / TAC 30% or more Within 5% none none No peeling Comparative Example 3 A / TAC Within 5% Within 5% Exfoliation none No peeling

* 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 (24)

An adhesive composition comprising a compound having an azetidinium functional group, a polyvinyl alcohol-based resin, and a basic compound, wherein the adhesive composition has a change in viscosity and pH over 7 days over 5%. The adhesive composition of claim 1, wherein the compound having an azetidinium functional group is a compound represented by the following Formula 1. [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 2, 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 3, 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 adhesive composition has a pH of 4 to 10. The adhesive composition of claim 1, wherein the basic compound is at least one selected from NaOH, KOH, and NH ₄ OH. The method of claim 1, wherein the polyvinyl alcohol-based resin is at least one selected from Japan Synthetic Chemicals Gohsefimer (trade name) Z-100, Z-200, Z-200H, Z-210, Z-220 and Z-320. Adhesive composition. The adhesive composition of claim 1, wherein the adhesive composition has a viscosity of 6 to 20 cP. Method of preparing an adhesive composition comprising the step of injecting a compound having an azetidinium functional group, a polyvinyl alcohol-based resin and a basic compound, and then for 3 to 24 hours at a temperature of 60 to 90 ℃. The method of claim 9, wherein the compound having an azetidinium functional group is a compound represented by the following Formula 1. [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 10, wherein the compound of Formula 1 is a compound of Formula 2 below: [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 11, 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 9, wherein the adhesive composition has a pH of 4 to 10. The method of claim 9, wherein the basic compound is at least one selected from NaOH, KOH, and NH ₄ OH. The method of claim 9, wherein the polyvinyl alcohol-based resin is at least one selected from Japan Synthetic Chemicals Gohsefimer (trade name) Z-100, Z-200, Z-200H, Z-210, Z-220 and Z-320. The manufacturing method of the adhesive composition. After adding a compound having an azetidinium functional group, a polyvinyl alcohol-based resin and a basic compound in sequence, it is prepared by a manufacturing method comprising the step of stirring for 3 to 24 hours at a temperature of 60 to 90 ℃ Adhesive composition. The adhesive composition according to claim 16, wherein the adhesive composition has a change of viscosity and pH over time for less than 5% for 7 days. 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 8, 16 and 17 is provided on at least one interface between the films. An optical film, characterized in that. The method according to claim 18, 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 18, 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 any one of claims 1 to 8, 16, and 17 is disposed between at least one of the first film and the second film and the polarizer. An adhesive layer formed using the adhesive composition according to claim is provided. The method according to claim 21, 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 21, wherein at least one surface of the first or second film is subjected to at least one surface treatment selected from an alkali treatment, a corona treatment, a plasma treatment, and a primer treatment. An electronic device comprising the polarizing plate of claim 21.

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