KR101956788B1

KR101956788B1 - Method for manufacturing polarizing plate and polarizing plate using the same

Info

Publication number: KR101956788B1
Application number: KR1020150135703A
Authority: KR
Inventors: 김경원; 장응진; 박준욱; 박기성
Original assignee: 주식회사 엘지화학
Priority date: 2015-09-24
Filing date: 2015-09-24
Publication date: 2019-03-11
Also published as: KR20170036482A

Abstract

The present invention relates to a method for producing an optical film and a polarizing plate using the same.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a polarizing plate,

The present invention relates to a method for producing a polarizing plate and a polarizing plate using the same.

The polarizing plate is applied to various display devices such as a liquid crystal display device, an organic electroluminescence device, and the like. A large number of polarizing plates that have been put into practical use for display devices at present are a polarizing film (polarizer) formed by dyeing and adsorbing a dichroic material such as iodine or a dichroic dye to a base film made of a polyvinyl alcohol film, And a protective film having optical transparency and mechanical strength are bonded to each other.

The acrylic polarizing plate protective film was complemented by introducing a primer layer on the surface of the film because adhesive strength was insufficient when the polarizing plate was bonded with a polarizing element alone. However, in the present plywood process, sufficient drying time is required for the adhesive force. In order to improve the yield, curling of the polarizing plate is caused due to a decrease in the drying time and a rise in the drying temperature.

Japanese Patent Laid-Open No. 2002-258051

The present invention provides a method of manufacturing a polarizing plate and a polarizing plate using the same.

One embodiment of the present invention relates to a method of manufacturing an acrylic film, comprising: forming a primer layer on at least one surface of an acrylic film using a primer composition; Treating the acrylic film formed with the primer layer with an alkaline aqueous solution; Bonding the polarizer to the acrylic film treated with the alkaline aqueous solution using an adhesive layer; And a step of hot-air drying the adhesive layer.

Another embodiment of the present invention provides a polarizing plate produced by the above method.

Another embodiment of the present disclosure relates to a display panel; And the polarizing plate attached to one surface or both surfaces of the display panel.

The polarizing plate according to one embodiment of the present invention can obtain an effect of improving the adhesive force even in a shorter time than the conventional drying time by pretreating the acrylic film coated with the primer layer.

Hereinafter, the present specification will be described in detail.

An embodiment of the present invention relates to a method of manufacturing an acrylic film, comprising: forming a primer layer on at least one surface of an acrylic film using a primer composition; Treating the acrylic film formed with the primer layer with an alkaline aqueous solution; Bonding the polarizer to the acrylic film treated with the alkaline aqueous solution using an adhesive layer; And a step of hot-air drying the adhesive layer.

The polarizer can be, but is not limited to, a film made of polyvinyl alcohol (PVA) comprising a polarizer well known in the art, for example, iodine or a dichroic dye. The polarizer can be produced by saponifying iodine or a dichroic dye to a polyvinyl alcohol film, but the production method is not particularly limited.

In the present specification, a polarizer means a state not including a protective layer (or a protective film), and a polarizer means a state including a polarizer and a protective layer (or a protective film).

On the other hand, the polarizer may have a thickness of about 5 탆 to 40 탆, specifically about 5 탆 to 25 탆. If the thickness of the polarizer is thinner than the above range, the optical characteristics may be deteriorated. If the thickness is larger than the above range, the amount of shrinkage of the polarizer at low temperature (about -30 캜) becomes large, which may cause problems with the durability of the entire polarizer plate.

When the polarizer is a polyvinyl alcohol-based film, the polyvinyl alcohol-based film can be used without particular limitation, provided that it contains a polyvinyl alcohol resin or a derivative thereof. At this time, derivatives of the polyvinyl alcohol resin include, but are not limited to, polyvinyl formal resins and polyvinyl acetal resins. Alternatively, the polyvinyl alcohol-based film may be a commercially available polyvinyl alcohol-based film commonly used in the art for producing polarizers such as P30, PE30 and PE60 of Kuraray Co., Ltd., M2000, M3000, It can also be used.

The polyvinyl alcohol-based film is not limited to this, but preferably has a degree of polymerization of about 1,000 to 10,000, and preferably about 1,500 to 5,000. When the degree of polymerization is within the above range, the molecular movement is free, and it is possible to mix with iodine or dichromatic dye or the like in a flexible manner.

In another embodiment of the present disclosure, the adhesive layer may comprise a polyvinyl alcohol (PVA) based resin. However, the present invention is not limited thereto, and the adhesive layer may include an adhesive used in the art. When the adhesive layer is hot-air dried after the adhesive layer is formed, the efficiency of the drying step can be increased and the drying time can be shortened.

In another embodiment of the present invention, the primer composition comprises a water-dispersible resin; And water-dispersed fine particles.

In one embodiment of the present invention, the primer composition further comprises a solvent capable of dispersing the water-dispersed fine particles.

In the present specification, water dispersion means a phenomenon in which other materials float in the aqueous solution in the form of fine particles. For example, the water-dispersible resin and the water-dispersed fine particles may be dispersed non-uniformly in a fine particle state in an aqueous solution such as water.

In one embodiment of the present invention, from 100 parts by weight of the primer composition, 70 to 99 parts by weight of a solvent capable of dispersing the water dispersion resin and the water dispersed fine particles may be contained, preferably 85 to 95 parts by weight And more preferably 90 to 93 parts by weight.

When the solvent is contained in an amount of more than 99 parts by weight based on 100 parts by weight of the primer composition, it is difficult to secure the thickness of the coating layer. When the amount of the solvent is less than 70 parts by weight, viscosity may be increased.

The primer composition may include 0.1 to 25 parts by weight of the water-dispersed fine particles based on 100 parts by weight of the water-dispersible resin.

When the water-dispersed fine particles are contained within the above-mentioned range, it is possible to prevent the problem that the film is not slipped between the films at the time of winding to cause breakage. In general, when the water-dispersed fine particles form a concavo-convex structure in the coating film, the slip property is improved, and this concavo-convex structure causes haze. Therefore, when the particle size increases, the concavo-convex structure also increases, and accordingly, the haze generally increases.

According to the present invention, even when water-dispersed fine particles of 50 nm or more are used, it is possible to prevent the haze value from rising by adjusting the content, thereby making it possible to produce a transparent film having a low haze.

In one embodiment of the present invention, the primer composition may further include not more than 30 parts by weight, preferably not less than 30 parts by weight, of the thermosetting cross-linking agent per 100 parts by weight of the water dispersion resin, Preferably not less than 0.1 and not more than 30 parts by weight.

When the thermosetting crosslinking agent is contained in the primer composition, the adhesion and durability of the primer composition can be improved. For example, the crosslinking agent can form a crosslinked structure with the water-dispersible resin or the water-dispersed fine particles while improving the adhesion with the acrylic film through the functional group, thereby providing a more dense internal structure.

The content of the thermosetting crosslinking agent is preferably within the above range. When the content is less than 0.1 part by weight, the cohesive force becomes small due to insufficient cross-linking, which may deteriorate the durability of the adhesive durability and cutability. If the content exceeds 30 parts by weight, a problem may occur in the residual stress relaxation due to the excessive cross-linking reaction.

In another embodiment of the present invention, the average diameter of the water-dispersed fine particles may be 50 nm to 500 nm, and may be specifically 100 nm to 300 nm. When the average diameter of the water-dispersed microparticles is within the above-mentioned range, stable surface energy is obtained, so that aggregation of silica in the primer solution occurs and precipitation can be prevented, thereby improving the stability of the solution.

In still another embodiment of the present invention, the water-dispersed fine particles may be at least one inorganic oxide selected from the group consisting of silica, titania, alumina, zirconia and antimony-based fine particles.

In still another embodiment of the present invention, the water-dispersible resin is composed of a urethane resin, an ester resin, an acrylic resin, a silicone resin, a fluorine resin, a crosslinked polyvinyl alcohol and a melamine resin, or a copolymerized or blended composite resin thereof Group, but is not limited thereto. Specifically, the urethane resin, the ester resin, and the acrylic resin may be polyurethane, polyester, or polyacrylic, respectively.

The water-dispersed fine particles may be any suitable fine particles and are preferably blended with an aqueous dispersion.

The water-dispersed fine particles are preferably silica, and the silica may be colloidal silica. Silica is excellent in blocking inhibition ability, excellent in transparency, low in haze occurrence, and free from coloration, so that the effect on the optical characteristics of the polarizing plate can be smaller. In addition, since silica has good dispersion and dispersion stability with respect to the primer composition, it has an advantage of excellent workability in forming a primer layer.

In one embodiment of the present invention, the thermosetting cross-linking agent is selected from the group consisting of an oxazoline cross-linking agent, a carbodiimide cross-linking agent, an aziridine cross-linking agent, a silane cross-linking agent, a melamine cross-linking agent epoxy cross-linking agent, a titanate cross- , But the present invention is not limited thereto.

The method for producing the acrylate-based resin film is not particularly limited. For example, an acrylate-based resin and other polymers and additives may be thoroughly mixed by any appropriate mixing method to prepare a thermoplastic resin composition, Alternatively, an acrylate resin and other polymers, additives and the like may be prepared as separate solutions and mixed to form a homogeneous mixture solution, followed by film formation.

The thermoplastic resin composition is prepared by pre-blending the film raw material with any suitable mixer such as an omni mixer, and then extruding and kneading the resulting mixture. In this case, the mixer used for the extrusion kneading is not particularly limited, and any suitable mixer such as an extruder such as a single screw extruder, a twin screw extruder, or a press kneader can be used.

The film forming method is not particularly limited, but any suitable film forming method such as solution casting method (solution casting method), melt extrusion method, calender method, compression molding method, and the like can be used. The extrusion method is preferable.

Examples of the solvent used in the solution casting method (solution casting method) include aromatic hydrocarbons such as benzene, toluene and xylene; Aliphatic hydrocarbons such as cyclohexane and decalin; Esters such as ethyl acetate and butyl acetate; Ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; Alcohols such as methanol, ethanol, isopropanol, butanol, isobutanol, methyl cellosolve, ethyl cellosolve and butyl cellosolve; Ethers such as tetrahydrofuran and dioxane; Halogenated hydrocarbons such as dichloromethane, chloroform and carbon tetrachloride; Dimethylformamide; Dimethyl sulfoxide and the like. These solvents may be used alone or in combination of two or more.

Examples of the apparatus for carrying out the solution casting method (solution casting method) include a drum casting machine, a band casting machine and a spin coater. Examples of the melt extrusion method include a T-die method and an inflation method. The molding temperature is preferably 150 to 350 占 폚, more preferably 200 to 300 占 폚.

When a film is formed by the T-die method, a T-die is attached to the tip of a known single-screw extruder or a twin-screw extruder, and a rolled film is obtained by winding a film extruded in a film form. At this time, uniaxial stretching can also be performed by stretching in the extrusion direction by appropriately adjusting the temperature of the winding roll. Further, simultaneous biaxial stretching, sequential biaxial stretching, and the like can also be carried out by stretching the film in a direction perpendicular to the extrusion direction.

The acrylic film may be either an unoriented film or a stretched film. In the case of a stretched film, it may be a uniaxially stretched film or a biaxially stretched film, and in the case of a biaxially stretched film, it may be a simultaneous biaxially stretched film or a sequential biaxially stretched film. When biaxially stretched, the mechanical strength is improved and the film performance is improved. By mixing other thermoplastic resins, the acrylic film can suppress an increase in retardation even when stretching, and can maintain optical isotropy.

The stretching temperature is preferably in the vicinity of the glass transition temperature of the thermoplastic resin composition as the raw material of the film and is preferably (glass transition temperature-30 占 폚) to (glass transition temperature + 100 占 폚) Temperature -20 占 폚) to (glass transition temperature + 80 占 폚). If the stretching temperature is lower than (glass transition temperature -30 占 폚), there is a possibility that a sufficient stretching ratio may not be obtained. On the other hand, if the stretching temperature exceeds (glass transition temperature + 100 deg. C), the resin composition may flow (flow), and stable drawing may not be performed.

The stretching ratio defined by the area ratio is preferably 1.1 to 25 times, more preferably 1.3 to 10 times. If the draw ratio is less than 1.1 times, there is a possibility that the toughness accompanying the draw may not be improved. If the stretching magnification exceeds 25 times, there is a possibility that the effect of increasing the stretching magnification may not be recognized.

The stretching speed is preferably 10 to 20,000% / min, more preferably 100 to 10.000% / min in one direction. When the drawing speed is less than 10% / min, it takes a long time to obtain a sufficient drawing magnification, which may increase the manufacturing cost. If the stretching speed is higher than 20,000% / min, the stretched film may be broken.

The acrylic film may be subjected to a heat treatment (annealing) after the stretching treatment so as to stabilize its optical isotropy or mechanical properties. The heat treatment conditions are not particularly limited and any suitable conditions known in the art can be employed.

In one embodiment of the present invention, the step of forming the primer layer may further include the step of modifying the acrylic film having the primer layer formed thereon.

In one embodiment of the present disclosure, the surface modification may be a plasma or corona treatment. The plasma treatment may be carried out as atmospheric _{plasma, 12V, N 2 2501pm, CDA} (Clean Dry Air) , but may be of 50 mm / sec under a 0.51pm, not limited to this, and appropriate changes.

The corona treatment may be performed at 60 V and at an ampere of 240 mm / sec. However, the present invention is not limited thereto and may be suitably modified.

Since the step of performing the surface modification such as plasma or corona treatment is carried out after forming the primer layer, the hydrogen bonding with the adhesive due to the hydroxyl group formation on the surface of the primer layer and the anchoring effect due to the etching of the surface of the primer layer There is an advantage that the adhesive liquid is well coated on the primer layer and adhesion with the adhesive resin is increased.

In one embodiment of the present invention, the acrylic film may include an alkyl (meth) acrylate-based unit. For example, the acrylic film may refer to a film containing acrylic resin or methacrylic resin as a main component.

In the present specification, the alkyl may be an alkyl group, and may be linear or branched. The number of carbon atoms is not particularly limited, but is preferably 1 to 40. Specific examples include methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec- N-pentyl, 3-dimethylbutyl, 2-ethylbutyl, heptyl, n-hexyl, N-octyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethyl Heptyl, 1-ethyl-propyl, 1,1-dimethyl-propyl, isohexyl, 2-methylpentyl, 4-methylhexyl, 5-methylhexyl and the like.

In this specification, the thickness of the primer layer may be 50 nm to 2000 nm, specifically 100 nm to 800 nm, more specifically 200 nm to 500 nm. The primer layer may be formed by applying the primer composition onto the optical film and drying the primer composition. The coating may be performed using a bar coating, a gravure, a slot die coater or the like commonly used in the art. When the thickness of the primer layer is within the above range, the adhesive force is sufficient and drying is sufficient. Therefore, the problem that the water dispersible fine particles are embedded in the primer layer and the slip property can not be properly applied can be prevented.

In one embodiment of the present invention, the alkaline aqueous solution may contain at least one alkaline agent selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide and ammonium hydroxide. When the acrylic film on which the primer layer is formed is treated with an alkaline aqueous solution, a swelling phenomenon of the primer coating layer occurs, and the alkaline component penetrates to the surface of the film to partially erode the surface, thereby widening the surface area. As a result, the contact area between the film surface and the primer is widened to increase the adhesion force between the primer layer and the primer. Further, when the film is peeled off at 90 degrees after the water-based adhesion, the acrylic interface is further broken, thereby improving the adhesion between the primer layer and the protective film.

In one embodiment of the present specification, the alkaline aqueous solution may be an aqueous solution of potassium hydroxide. When the aqueous potassium hydroxide solution is used as the alkaline aqueous solution, the concentration can be adjusted over a wide range by a simple method.

On the other hand, the solvent used for the alkaline aqueous solution may be a mixture of an alcohol having a small carbon number such as methanol and ethanol, and water. However, since the acrylate resin has a very low solubility in alcohol, On the contrary, if the content of alcohol is increased, there is a possibility that the appearance defect of the film surface may occur. When a mixed solvent of alcohol and water is used in an amount of about 10 wt% as a solvent used in an alkaline aqueous solution, defective appearance on the surface of the film can be prevented, and more preferably only water can be used.

In another embodiment of the present invention, the concentration of the alkaline aqueous solution may be 30 wt% or less, specifically 20 wt% or less, more specifically 10 wt% or less, based on 100 wt% of the alkaline aqueous solution. Meanwhile, the concentration of the alkaline aqueous solution may be more than 1 wt%.

The concentration of the alkaline aqueous solution may be a concentration at which an alkaline substance is dissolved in deionized water. For example, when the concentration of the aqueous solution of potassium hydroxide is 10 wt%, deionized water and potassium hydroxide may be prepared at a weight ratio of 9: 1.

In one embodiment of the present invention, the step of treating with the alkaline aqueous solution may be carried out at 30 ° C to 70 ° C, specifically at 40 ° C to 60 ° C. When the temperature to be treated with the alkaline aqueous solution is within the above range, it is possible to prevent the decomposition of the primer, to reduce the line-speed of the plant or to increase the length of the alkaline bath to secure sufficient immersion time .

In another embodiment of the present disclosure, the step of treating with the alkaline aqueous solution may be to immerse the acrylic film in an alkaline aqueous solution for 10 seconds to 2 minutes. Specifically, the acrylic film may be immersed in an alkaline aqueous solution for 30 seconds to 1 minute. When the acrylic film is immersed for the above-mentioned period of time, suitable primer swelling and partial erosion of the film surface can proceed, and there is an advantage that the appearance defect phenomenon due to foreign matters on the film surface can be minimized.

In still another embodiment of the present invention, the method may further include washing the acrylic film after the step of treating with the alkaline aqueous solution. The washing step is not limited as long as it is a method known in the art, and for example, it may be a method of immersing in a water bath.

In one embodiment of the present invention, the hot air drying step may be performed at 40 ° C to 90 ° C, specifically, 50 ° C to 80 ° C, more specifically, 50 ° C to 70 ° C. The drying time in the drying step may be 30 seconds to 2 minutes, and may be 30 seconds to 1 minute, but is not limited thereto.

When the drying temperature and the drying time are within the above range, the drying efficiency can be maximized without damaging the primer layer without lowering the orientation of the oriented acrylate film.

In the present specification, hot air drying means a drying method using heated air or gas as a drying medium. Since hot air drying does not require direct heating of the sample, there is little fear of local overheating, and since the newly heated dry air is introduced, a new gas phase equilibrium is always established, not a static equilibrium. .

In one embodiment of the present invention, the step of treating the acrylic film with an alkaline aqueous solution may further include a step of hot air-drying the acrylic film, but the present invention is not limited thereto.

The drying may be carried out at the time of preparing the acrylic film or after coating the coating liquid (primer solution). The method may further include a step of alkali-treating the optical film into which the primer layer has been introduced, washing it with water, and then performing hot-air drying. The alkali-treated film is laminated with the PVA element and other films and an aqueous adhesive, But is not limited thereto.

In one embodiment of the present invention, the polarizing plate manufacturing method includes the manufacturing method of the acrylic film described above.

One embodiment of the present invention provides a polarizing plate produced by the method for producing a polarizing plate.

An embodiment of the present invention is a display panel comprising: a display panel; And the polarizing plate attached to one surface or both surfaces of the display panel.

The display panel may be a liquid crystal panel, a plasma panel, and an organic light emitting panel. The image display device may be a liquid crystal display (LCD), a plasma display panel (PDP), and an organic light emitting display (OLED).

Specifically, the image display device may be a liquid crystal display device including a liquid crystal panel and polarizing plates respectively provided on both surfaces of the liquid crystal panel. At least one of the polarizing plates may be a polarizing plate according to the above- Lt; / RTI >

At this time, the type of the liquid crystal panel included in the liquid crystal display device is not particularly limited. A passive matrix type panel such as a twisted nematic (TN) type, a super twisted nematic (STN) type, a ferroelectic (F) type or a polymer dispersed (PD) type; An active matrix type panel such as a two terminal or a three terminal; A known panel such as an in-plane switching (IPS) panel and a vertical alignment (VA) panel may be used. Further, the other constituent elements constituting the liquid crystal display device, for example, the types of the upper and lower substrates (for example, a color filter substrate or an array substrate) are not particularly limited and the structures known in this field are not limited Can be employed.

Hereinafter, the present invention will be described in detail by way of examples to illustrate the present invention. However, the embodiments according to the present disclosure can be modified in various other forms, and the scope of the present specification is not construed as being limited to the above-described embodiments. Embodiments of the present disclosure are provided to more fully describe the present disclosure to those of ordinary skill in the art.

[Example 1]

An unoriented film having a width of 800 mm was prepared by using an acrylic resin (MR1000 resin manufactured by Nippon Catalyst Co., Ltd.) under 250 rpm at 250 rpm using a T-die shaker and stretched 1.8 times in the MD direction at a temperature of 140 캜, A film was prepared.

2.33 g of water-dispersed polyurethane resin (CK-PUD Coating paint: 30% aqueous solution of solid content), 0.7 g of water-dispersed silica (average particle diameter 90 nm, aqueous 20% solid solution) and 6.97 g of pure water were mixed to prepare a primer composition Respectively.

The prepared primer composition was coated on a longitudinally oriented (MD direction) stretched acrylic film with a Mayer bar, dried at 95 ° C, and then stretched 2.5 times in the TD direction at 140 ° C.

The obtained film was immersed in a 10% aqueous solution of KOH at 50 DEG C for 25 seconds, rinsed with DI water at room temperature for 1 minute, and then dried with an air shower and an oven at 60 DEG C.

The pretreated acrylic film and the TAC film were laminated on both sides of the polarizing element using a PVA water-based adhesive, and then dried by hot air at 80 ° C and 1000 rpm in a Matis oven to produce a polarizing plate.

[Example 2]

A polarizing plate was prepared in the same manner as in Example 1, except that the corona treatment was performed before the KOH aqueous solution treatment. At this time, the corona was treated at 60 V, ampere at 240 mm / sec.

[Example 3]

A polarizing plate was prepared in the same manner as in Example 1, except that the plasma treatment was performed before the KOH aqueous solution treatment. At this time, the plasma was treated with atmospheric plasma at 12 V, N ₂ 250 lpm, CDA 0.5 lpm, and 50 mm / sec.

[Example 4]

A polarizing plate was prepared in the same manner as in Example 1 except that a crosslinking agent was added to the primer composition. 2.33 g of a water-dispersed polyurethane resin (CK-PUD Coating Paint: 30% aqueous solution of solid content), 0.14 g of a thermosetting crosslinking agent (WS-700 solid content 25% by Nippon Catalyst Co., Ltd. (oxazoline crosslinking agent) 0.7 g of water-dispersed silica (average particle diameter 90 nm, aqueous 20% solid solution), and 7.33 g of pure water.

[Example 5]

A polarizing plate was prepared in the same manner as in Example 4 except that the type of the crosslinking agent was changed to the primer composition. The primer composition contained 0.033 g of a thermosetting crosslinking agent (SV-02, solid content: 40% (carbodiimide-based crosslinking agent)), 2.33 g of water-dispersed polyurethane resin (CK- , 0.7 g of water-dispersed silica (average particle size of 90 nm, aqueous 20% solid solution) and 7.38 g of pure water.

[ Comparative Example One]

A polarizing plate was prepared in the same manner as in Example 1, except for the step of immersing in KOH aqueous solution in Example 1.

[ Comparative Example 2]

A polarizing plate was prepared in the same manner as in Example 2, except that it was immersed in a KOH aqueous solution in Example 2.

[ Comparative Example 3]

A polarizing plate was prepared in the same manner as in Example 3, except for the step of immersing in KOH aqueous solution in Example 3.

[ Comparative Example 4]

A polarizing plate was prepared in the same manner as in Example 4, except that in Example 4, the substrate was immersed in a KOH aqueous solution.

[ Comparative Example 5]

A polarizing plate was prepared in the same manner as in Example 5, except that it was immersed in a KOH aqueous solution in Example 5.

[ Experimental Example ] - Evaluation of adhesion of polarizer

A polarizer is prepared by laminating an acrylic film coated with a primer, a PVA polarizer, and another protective film (TAC film) with an adhesive (aqueous adhesive of PVA base). The prepared polarizer plate was cut to a width of 2 cm, and the acrylic film surface was fixed to the texture analyzer. Then, the PVA polarizer attached to the TAC film was pulled for 6 seconds at a speed of 90 °, 0.05 N, 0.5 cm / Was evaluated. The results are shown in Table 1 below.

○ (Phase): The broken area of the acrylic base film on the adhesive surface is over 70%.

△ (middle): The breakdown area of acrylic base film at the adhesive surface is between 30 and 70%.

X (bottom): Less than 30% of the area of the acrylic base film is broken at the bonding surface.

Film type Primer composition Processing order Adhesion by drying time corona plasma KOH soaking 1 minute 1.5 minutes 2 minutes 3 minutes 5 minutes Example 1 acryl PU /
Silica - - ○ X △ ○ ○ ○ Example 2 ○ - ○ X ○ ○ ○ ○ Example 3 - ○ ○ X ○ ○ ○ ○ Example 4 PU /
Cross-linking agent / silica - - ○ X △ ○ ○ ○ Example 5 - - ○ X △ ○ ○ ○ Comparative Example 1 PU /
Silica - - - X X X △ △ Comparative Example 2 ○ - - X △ △ △ △ Comparative Example 3 - ○ - X △ △ △ △ Comparative Example 4 PU /
Cross-linking agent / silica - - - X X X △ △ Comparative Example 5 - - - X X X △ △

As can be seen from Table 1, when the acryl film coated with the primer layer of the present invention was subjected to corona or plasma treatment and immersed in KOH, initial adhesion and final adhesion were improved. Also, it can be confirmed that the adhesive strength is excellent even in a short drying time.

Claims

Forming a primer layer on at least one side of the acrylic film using a primer composition;
Treating the acrylic film formed with the primer layer with an alkaline aqueous solution after the step of forming the primer layer, after the surface modification of the acrylic film having the primer layer formed thereon;
Bonding the polarizer to the acrylic film treated with the alkaline aqueous solution using an adhesive layer; And
And drying the adhesive layer by hot air.

The method according to claim 1, wherein the alkaline aqueous solution comprises at least one alkali agent selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide and ammonium hydroxide.

The method of manufacturing a polarizing plate according to claim 1, wherein the alkaline aqueous solution is an aqueous solution of potassium hydroxide.

The method for producing a polarizing plate according to claim 1, wherein the concentration of the alkaline aqueous solution is 30 wt% or less.

The method of manufacturing a polarizing plate according to claim 1, wherein the treatment with the alkaline aqueous solution is performed at 20 캜 to 70 캜.

The method of manufacturing a polarizing plate according to claim 1, wherein in the step of treating with the alkaline aqueous solution, the acrylic film is immersed in an alkaline aqueous solution for 5 seconds to 2 minutes.

The method of manufacturing a polarizing plate according to claim 1, further comprising washing the acrylic film after the step of treating with the alkaline aqueous solution.

The method of manufacturing a polarizing plate according to claim 1, further comprising a step of subjecting the acrylic film to hot air drying after the acrylic film is treated with an alkaline aqueous solution.

The method of manufacturing a polarizing plate according to claim 1, wherein the hot air drying step is performed at 40 ° C to 100 ° C.

The method of manufacturing a polarizing plate according to claim 1, wherein the primer composition comprises a water-dispersible resin.

11. The polarizing plate according to claim 10, wherein the water-dispersible resin is at least one selected from the group consisting of a urethane resin, an ester resin, a silicone resin, a fluorine resin, a (meth) acrylic resin, a crosslinked polyvinyl alcohol and a melamine resin Way.

[Claim 11] The method according to claim 10, wherein the primer composition further comprises 0 to 30 parts by weight of a thermosetting crosslinking agent per 100 parts by weight of the water dispersion resin.

[12] The thermosetting resin composition according to claim 12, wherein the thermosetting crosslinking agent is selected from the group consisting of an oxazoline crosslinking agent, a carbodiimide crosslinking agent, an aziridine crosslinking agent, a silane crosslinking agent, a melamine crosslinking agent, an epoxy crosslinking agent, a titanate crosslinking agent and a zirconate crosslinking agent Wherein the polarizing plate is at least one selected from the group consisting of a polarizing plate and a polarizing plate.

The method according to claim 1, wherein the thickness of the primer layer is 50 nm to 2000 nm.

delete

The method of manufacturing a polarizing plate according to claim 1, wherein the surface modification is a plasma or corona treatment.

The method of manufacturing a polarizing plate according to claim 1, wherein the adhesive layer comprises a polyvinyl alcohol (PVA) -based resin.

The method of manufacturing a polarizing plate according to claim 1, wherein the acrylic film comprises an alkyl (meth) acrylate-based unit.

A polarizing plate produced by the manufacturing method according to any one of claims 1 to 14 and 16 to 18.

Display panel; And a polarizing plate according to claim 19 attached to one or both surfaces of the display panel.