KR20190085723A - Coating composition, polarizer protecting film, manufacturing method of polarizer protecting film, polarizing plate comprising same and liquid crystal display device comprising same - Google Patents

Abstract

The present invention relates to a polarizer protective film comprising a base film; and a coating layer provided on one side or both sides of the base film. The present invention specifically relates to a polarizer protective film and a liquid crystal display including the same, wherein the coating layer comprises a thermosetting resin; at least one additive selected from the group consisting of reactive or non-reactive silicone additives and reactive or non-reactive fluorine additives; and a heat initiator, and at least one of the additives includes a reactive silicone additive or a reactive fluorine additive.

Description

TECHNICAL FIELD [0001] The present invention relates to a coating composition, a polarizer protective film, a method for producing a polarizer protective film, a polarizing plate including the same, and a liquid crystal display device including the polarizer protective film. SAME}

The present invention relates to a coating composition, a polarizer protective film, a method for producing a polarizer protective film, a polarizing plate including the same, and a liquid crystal display device including the polarizing plate and the polarizing plate, which can exhibit excellent physical and optical characteristics, To a polarizer protective film.

BACKGROUND ART [0002] Liquid crystal display devices are widely used from cellular phones and portable electronic devices to personal computers and large-sized electronic devices such as televisions, and their use is one of the ever-expanding flat panel displays. Since such a liquid crystal display device is not a self-luminous type device, a light source such as a backlight unit is usually placed on the back of a lower polarizer plate provided on the lower side of the liquid crystal cell, and the light emitted from the light source is transmitted through the liquid crystal cell, So that an image is displayed.

In recent years, a large load has been applied to the central portion of the liquid crystal cell, and a sagging phenomenon of the lower polarizer is generated. Thus, the polarizer protective film of the lower polarizer attached to the liquid crystal cell And the lower polarizing plate is caught by the diffusion sheet on the surface of the backlight unit. To solve this problem, a method of coating a hard coating layer on a protective film of a lower polarizer plate has been proposed, but there is a problem of an increase in process cost.

According to this necessity, development of a method of preventing the lower polarizer plate from being damaged while reducing the cost of the process and having price competitiveness is required.

Korean Laid-Open Publication No. 2012-0107256

Disclosed is a polarizer protective film of a lower polarizer. The polarizer protective film has excellent coating properties, a high surface hardness and a scratch resistance, a polarizer having excellent physical and optical properties, A liquid crystal display device is provided.

One embodiment of the present application relates to a substrate film; And a coating layer provided on one surface or both surfaces of the base film, wherein the coating layer comprises a thermosetting resin; One or more additives selected from the group consisting of reactive or non-reactive silicone additives and reactive or non-reactive fluoric additives; And a thermal initiator, wherein at least one of the additives includes the reactive silicon-based additive or the reactive fluorine-based additive.

Another embodiment includes a thermosetting resin; One or more additives selected from the group consisting of reactive or non-reactive silicone additives and reactive or non-reactive fluoric additives; And a thermal initiator, wherein at least one of the additives comprises the reactive silicon-based additive or the reactive fluorine-based additive.

Another embodiment provides a method of manufacturing a semiconductor device, comprising: preparing a substrate film; Applying a coating composition according to one embodiment of the present application on at least one side of a substrate film; And a step of stretching the base film coated with the coating composition.

Another embodiment includes a polarizer; And a polarizer protective film according to an embodiment of the present application on at least one side of the polarizer.

Finally, one embodiment of the present application relates to a liquid crystal cell comprising: a liquid crystal cell; An upper polarizer provided on an upper portion of the liquid crystal cell; A lower polarizer disposed on a lower portion of the liquid crystal cell; And a backlight unit provided on a lower portion of the lower polarizer, wherein the lower polarizer comprises a polarizer; And a polarizer protective film according to an embodiment of the present application disposed on one side or both sides of the polarizer.

Disclosed is a polarizer protective film of a lower polarizer. The polarizer protective film has excellent coating properties, a high surface hardness and a scratch resistance, a polarizer having excellent physical and optical properties, A liquid crystal display device is provided.

Particularly, at least one of the additives of the polarizer protective film of the present invention comprises a reactive silicon additive or a reactive fluorine-based additive, and the polarizer protective film of the present invention is excellent in stability of the film, coating property, anti- And slip property to give excellent coating and breaking properties.

In addition, the coating composition of the present invention can include a thermal initiator to enable curing to be induced in a stretching process without the need for a specific thermosetting or UV curing process in the later production of the polarizer protective film, .

In addition, since the polarizer protective film including the coating composition is used as a protective film of the lower polarizer, the polarizer protective film is damaged by abutting against the diffusion sheet on the surface of the backlight unit due to deflection of the lower polarizer, And can exhibit excellent optical properties.

1 is a view illustrating a liquid crystal display device according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described. However, the embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. Further, the embodiments of the present invention are provided to explain the present invention in more detail to those skilled in the art.

The present invention relates to a polarizer protective film adjacent to a backlight unit of a lower polarizer plate provided in a lower layer portion of a liquid crystal cell in a liquid crystal display device, wherein at least one of the additives of the polarizer protective film is an acrylate- And a hydroxyl group, the polarizer protective film of the present invention imparts stability, coating property, anti-blocking property and slip property of the thermosetting resin to the thermosetting resin, It is excellent in cutting characteristics.

In addition, the polarizer protective film made of the coating composition of the present invention can prevent damage that may occur due to the sagging phenomenon of the lower polarizer.

1 shows an embodiment of a liquid crystal display device according to the present invention. The liquid crystal display device shown in Fig. 1 includes a liquid crystal cell 20; An upper polarizer plate 10 provided on an upper portion of the liquid crystal cell 20; A lower polarizer plate 30 provided on a lower portion of the liquid crystal cell 20; And a backlight unit 40 provided on a lower portion of the lower polarizer plate. The polarizer protection film 34 is provided on the lower polarizer plate 30 adjacent to the backlight unit.

In the present invention, the terms 'upper surface' and 'upper' mean a surface or a direction arranged toward a viewer side, that is, a viewer side when a polarizing plate is mounted on a device such as a liquid crystal display device. Conversely, 'under' and 'under' mean the face or direction opposite the viewer, that is, facing the backlight unit when the polarizer is mounted on the device.

Hereinafter, the coating composition, the polarizer protective film, the method for producing the polarizer protective film, the polarizer including the polarizer protective film, and the liquid crystal display including the polarizer will be described in detail.

One embodiment of the present application is a thermosetting resin composition comprising: a thermosetting resin; One or more additives selected from the group consisting of reactive or non-reactive silicone additives and reactive or non-reactive fluoric additives; And a thermal initiator, wherein at least one of the additives comprises a reactive silicon-based additive or a reactive fluorinated additive.

In one embodiment of the present application, the thermosetting resin may be a cationic thermosetting resin.

In one embodiment of the present application, the thermosetting resin comprises an epoxy-based compound.

According to one embodiment of the present application, the weight average molecular weight of the epoxy compound is not particularly limited, but may be about 100 to 5,000 g / mol, or about 200 to 5,000 g / mol. If the weight average molecular weight of the epoxy compound is too large, the viscosity may be high and the coating property may be poor. If the weight average molecular weight is too small, the hardness is low.

The epoxy compound includes at least one epoxy group, and examples thereof include an aromatic epoxy compound, a hydrogenated epoxy compound, an alicyclic epoxy compound, and an aliphatic epoxy compound, and preferably an alicyclic epoxy compound .

In one embodiment of the present application, the epoxy compound is an alicyclic epoxy compound.

The aromatic epoxy compound refers to an epoxy compound containing at least one aromatic hydrocarbon ring in the molecule and includes, for example, diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F , Bisphenol-type epoxy resins such as diglycidyl ether of bisphenol S; Phenol novolak epoxy resin, cresol novolak epoxy resin, and hydroxybenzaldehyde phenol novolak epoxy resin, glycidyl ether of tetrahydroxyphenylmethane, glycidyl ether of tetrahydroxybenzophenone, epoxy And polyvinylphenol, and the like.

The hydrogenated epoxy compound refers to an epoxy compound obtained by selectively hydrogenating the aromatic epoxy compound under a pressure in the presence of a catalyst, but is not limited thereto. Of these, the hydrogenated bisphenol A It is preferable to use diglycidyl ether.

The alicyclic epoxy compound means an epoxy compound in which an epoxy group is formed between adjacent two carbon atoms constituting an aliphatic hydrocarbon ring, but is not limited thereto. For example, 2- (3, Epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4,5- Epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6-methylcyclohexanecarboxylate, vinylcyclohexanedioxide, bis (3,4-epoxycyclohexylmethyl) adipate, bis Epoxycyclohexylmethyl) adipate, exo-exobis (2,3-epoxycyclopentyl) ether, endo-exobis (2,3-epoxycyclopentyl) ether, 2,2-bis [4 - (2,3-epoxypropoxy) cyclohexyl] propane, 2,6-bis (2,3-epoxypropoxycyclohexyl-p-dioxane), 2,6- Bis (3,4-epoxycyclohexyl) propane, dicyclopentadienedioxide, 1,2-epoxy-6- (2,3-epoxypropoxy) (2,3-epoxy) cyclopentylphenyl-2,3-epoxypropyl ether, 1- (2,3-epoxypropoxy) phenyl-5,6- (2,3-epoxy) cyclopentylphenyl-2,3-epoxypropyl ether), 1,2-bis [5- (1,2-epoxy) -4 Ethanocyclopentenyl phenyl glycidyl ether, methylene bis (3,4-epoxycyclohexane) ethylene glycol di (3,4-epoxycyclohexylmethyl) ether, ethylene bis (3, Epoxycyclohexanecarboxylate), ε-caprolactone (1 to 10 mol) adduct of 3,4-epoxycyclohexanemethanol and poly (3 to 20) alcohol (GR, TMP, PE, DPE, Hexapentaerythritol), and the like. Among them, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate is particularly preferably used from the viewpoint of reactivity.

In one embodiment of the present application, the thermal initiator may be a cationic demethanizer.

In one embodiment of the present application, the thermal initiator preferably has a thermal curing initiation temperature of 100 ° C or more and 180 ° C or less.

The thermal initiator means a compound which produces a cation or a Lewis acid by heat treatment and acts on a cationic polymerizable group such as an epoxy group to initiate a cationic polymerization reaction.

At this time, thermal initiators generally used in the art can be used without limitation. For example, a sulfonium salt, an ammonium salt, a phosphonium salt, an onium salt, an iodonium salt, an iodonium salt, and the like. Specific examples thereof include ammonium / antimony hexafluoride, triarylsulfonium hexafluoroantimonate salts, trianylsulfonium hexafluoroantimonate, (Tolylumil) iodonium tetrakis (pentafluorophenyl) borate, Bis (dodecylphenyl) iodonium hexafluoroantimonate, iodonium (4-methylphenyl) (4- (2-methylpropyl) phenyl) hexafluorophosphate, octyldiphenyliodonium hexafluoroantimonate Benzylpyridinium salts, N-benzylpyridinium salts, N-benzylammonium salts, phosphonium salts, hydrazinium salts, ammonium borate salts, triaryl iodonium salts, benzylsulfonium salts, phenacylsulfonium salts, Phenylmethyl chloride, and mixtures thereof, preferably ammonium / antimony hexafluoride, trianylsulfonium hexafluoroantimonate, triphenylmethyl chloride, and the like.

In one embodiment of the present application, the thermal initiator may comprise a sulfonium salt or an iodonium salt.

In one embodiment of the present application, the thermal initiator is a sulfonium salt or an iodonium salt TEPB ^- may be included in addition ^-, SbF6 ^-, or PF6.

In the above-mentioned case, SI-80 ((4-hydroxyphenyl) 2-methylbenzyl) methylsulfonium hexafluoroantimonate), SI-100 ( Benzyltetramethylenesulfonium hexafluoroantimonate), SI-150 (4-Acetoxyphenyldimethylsulfonium hexafluoroantimonate), SI-B2A ((4) -acetoxyphenyldimethylsulfonium hexafluoroantimonate) (4-acetoxyphenyl) 2-methylbenzyl (methyl) sulfonium, tetrakis (pentafluorophenyl) borate (1: 1: 1), SI-B3 (benzyl (4-hydroxyphenyl) methylsulfonium, tetrakis (pentafluorophenyl) (4-acetoxyphenyl) benzyl (methyl) sulfonium, tetrakis (pentafluorophenyl) borate (1: 1) (acetyloxy) phenyl] benzylmethylsulfonium, hexafluorophosphate [4- (acetyloxy) phenyl] benzenesulfonate, tetrakis (pentafluorophenyl) benzylmethylsulfonium, hexafluorophosphate, SI-360 ((4-hydroxyphenyl) methyl (1-naphthalenylmethyl) sulfonium, 4-hydroxyphenyl, methyl (1-naphthalenylmethyl) sulfonium and hexafluorophosphate) .

In one embodiment of the present application, the thermal initiator is selected from the group consisting of benzyl (4-hydroxyphenyl) methylsulfonium, tetrakis (pentafluorophenyl) methylsulfonium, tetrakis (pentafluorophenyl) borate : 1)).

In one embodiment of the present application, the coating composition may further comprise a photoinitiator.

In one embodiment of the present application, the photoinitiator may be a cationic photoinitiator.

In one embodiment of the present application, the photoinitiator refers to a compound that produces a cationic species or Lewis acid by irradiation with an active energy ray such as ultraviolet rays, and acts on a cationic polymerizable group such as an epoxy group to initiate cationic polymerization reaction .

In one embodiment of the present application, the photoinitiator is for improving the curing rate by promoting the polymerizability. As the photoinitiator, photoinitiators commonly used in the art can be used without limitation.

In one embodiment of the present application, the photoinitiator may comprise a sulfonium salt.

In one embodiment of the present application, the photoinitiator may be Diphenyl [(phenylthio) phenyl] sulfonium hexafluorophosphate (1-).

When the thermal initiator and the photoinitiator are used together in the coating layer of the polarizer protective film according to one embodiment of the present application, the surface hardness is improved and the breaking property is particularly excellent.

The coating composition according to one embodiment of the present application may contain one or more additives selected from the group consisting of reactive or non-reactive silicone additives and reactive or non-reactive fluoric additives.

The coating composition according to still another embodiment may comprise one or two additives selected from the group consisting of reactive or non-reactive silicon-based additives and reactive or non-reactive fluorinated additives.

In particular, at least one of the additives includes a reactive silicon-based additive or a reactive fluorine-based additive.

The coating composition according to one embodiment of the present application comprises a reactive silicon-based additive and a non-reactive silicon-based additive.

The coating composition according to one embodiment of the present application may include a reactive silicon-based additive alone.

The coating composition according to one embodiment of the present application may contain a reactive fluorine-based additive alone.

When the reactive type additive and the non-reactive type additive are used simultaneously, the non-reactive additive improves the coating property and the shattering property, and at the same time, the reactive additive improves the extrusion of the additive, .

In addition, when only the reactive additive is used alone as the additive, the additive reacts directly with the thermosetting resin to prevent the additive from leaching out from the surface.

The reactive silicon-based additive is an additive containing a functional group capable of cationic polymerization to an additive at the time of cationic polymerization, and includes at least one of an acrylate-based, epoxy-based, and hydroxyl- Means a silicone-based additive.

Examples of the reactive silicone additives include KF-102, KF-6002, KF-6003, X-22-169B, X-22-170BX, X-22-170DX, X-22-4015, Slimer OHT DI-10, Slimer OHT DI-50, Slimer EP J10, TEGO Protect 5000N, TEGO Protect 5001, TEGO Protect 5100N, TEGO LAG 876 and the like can be used. It does not.

The KF-102, KF-6002, KF-6003, X-22-169B, X-22,170BX, X-22-170DX, X-22-4015 and X-22-4039 are reaction- Slimer OH C50, Slimer OHT DI-10, Slimer OHT DI-50, and Slimer EP J10 are the reaction type silicone additives of Siltech, and the TEGO Protect 5000N, TEGO Protect 5001 , TEGO Protect 5100N and TEGO LAG 876 are reactive silicon-based additives of TEGO, and the reactive silicon-based additives include at least one of acrylate, epoxy and hydroxyl-based reactors.

The reactive fluorine-based additive is an additive containing a functional group capable of cationic polymerization to the additive when cationic polymerization is carried out, and includes at least one of an acrylate-based, epoxy-based, and hydroxyl- Means a fluorine-based additive.

Examples of the reactive fluorine-based additive include MEGAFACE RS-56, Fluorosil OH ACR C7-F, and the like.

The MEGAFACE RS-56 is a reactive fluorinated additive of DIC, the Fluorosil OH ACR C7-F is a reactive fluorinated additive of Siltech, and the reactive fluorinated additive is at least one of an acrylate, epoxy, Or more.

The non-reactive silicon-based additive is an additive that does not contain a functional group capable of cationic polymerization to the additive at the time of cationic polymerization and has a silicon group such as dimethylsiloxane or methylsiloxane, Polyether groups and the like.

Examples of the non-reactive silicone additive include, but are not limited to, TEGO RAD 2100 and TEGORAD 2200N.

The above-mentioned TEGO RAD 2100 and TEGORAD 2200N are non-reactive silicone additives of TEGO Co., which are silicon group-containing additives such as dimethylsiloxane and methylsiloxane.

The non-reactive fluorine-based additive may have a fluorine group such as a fluoroalkyl group.

In one embodiment of the present application, the coating composition comprises, based on 100 parts by weight of the thermosetting resin, 0.1 to 10 parts by weight of the additive; And 0.01 to 5 parts by weight of the thermal initiator.

In one embodiment of the present application, the additive may be added in an amount of 0.1 to 10 parts by weight, preferably 0.2 to 5 parts by weight, more preferably 0.3 to 2 parts by weight, based on 100 parts by weight of the thermosetting resin.

When the additive falls within the above-mentioned range, the coating property and the shattering property of the polarizer protective film are improved and the additive dissolution phenomenon can be prevented. In other words, when the amount exceeds the above range, the caking property can be greatly improved, but the additive dissolution phenomenon occurs.

In one embodiment of the present application, the heat initiator may be used in an amount of 0.01 to 5 parts by weight, preferably 0.05 to 4 parts by weight, more preferably 0.08 to 3 parts by weight, based on 100 parts by weight of the thermosetting resin .

When the thermal initiator is used in the above-described range at an elevated temperature, it is possible to use an optimal amount, thereby obtaining a desired molecular weight at a minimum price and also capable of maintaining a proper curing rate .

According to one embodiment of the present invention, the coating composition may further comprise an oxetane-based compound as a thermosetting resin.

The oxetane-based compound contains at least one oxetane group, and is cured by cations generated from a thermal initiator by heat treatment. The binder is not limited to any particular kind.

The oxetane-based compound can lower the viscosity of the coating composition and can further improve the curing rate.

More specifically, the oxetane-based compound may be, for example, 3-ethyl-3 - [(3-ethyloxetan-3-yl) methoxymethyl] oxetane, 1,4-bis [ 3-yl) methoxy] benzene, 1,3-bis [(3-ethyloxetan-3-yl) Methoxy] benzene, 4,4'-bis [(3-ethyloxetan-3-yl) methoxy] biphenyl, Bis [(3-ethyloxetan-3-yl) methoxy] biphenyl, 3,3 ', 5,5'-tetramethyl-4,4'- 3-yl) methoxy] biphenyl, 2,7-bis [(3-ethyloxetan-3- yl) methoxy] naphthalene, bis {4- [ Methoxy] phenyl} methane, 2,2-bis {4 - [(3-ethyloxetan-3-yl) methane] Ethoxy] phenyl} propane, 3-chloromethyl-3-ethyloxetane etherified product of novolac phenol-formaldehyde resin, 3 (4) Yl) methoxymethyl] -tricyclo [5. 2.1.0 2,6] decane, 2,3-bis [(3-ethyloxetan-3-yl) methoxymethyl] norborane, 1,1,1-tris [ (Methoxymethyl) propane, 1-butoxy-2,2-bis [(3-ethyloxetan-3- yl) methoxymethyl] Ethyl} oxetan-3-yl) methoxy] ethylthio} ethane, bis {[4- Cetan-3-yl) methoxy] -2,2,3,3,4,4,5,5-octafluorohexane.

According to one embodiment of the present invention, there is provided a process for preparing 3-ethyl-3- (hydroxymethyl) oxetane, m-tetramethyl-xylene diisocyanate azelaic chloride, terephthaloyl chloride and 1,3,5- And tricarbonyl trichloride can be used as the compound of the present invention.

When the oxetane-based compound is further included, the content thereof may be about 5 to about 80 parts by weight, and preferably about 10 to about 60 parts by weight based on 100 parts by weight of the epoxy compound. When the oxetane-based compound is contained in an excessively large amount, the hardness of the coating layer after curing may be lowered. When the content of the oxetane-based compound is too small, the effect of addition of the oxetane-based compound is insignificant.

According to one embodiment of the present invention, the coating composition may comprise a photocurable binder. If the coating composition comprises a photocurable binder, a UV curing process may be added during curing of the coating composition. At this time, the ultraviolet irradiation amount of the UV curing process may be 20 to 800 mJ / cm ² . The light source for ultraviolet irradiation is not particularly limited as long as it can be used in the technical field to which the present technology belongs. For example, a high pressure mercury lamp, a metal halide lamp, a black light fluorescent lamp and the like can be used.

The coating composition of the present invention is low in viscosity and good in coatability and can be used in a solvent-free type without a solvent. However, it does not exclude the use of an organic solvent, and may contain a small amount of an organic solvent generally used in the art if necessary. At this time, the organic solvent may be used in an amount of about 20 parts by weight or less based on 100 parts by weight of the coating composition for the entire polarizer protective film.

Examples of usable organic solvents include alcohol solvents such as methanol, ethanol, isopropyl alcohol and butanol, alkoxy alcohol solvents such as 2-methoxyethanol, 2-ethoxyethanol and 1-methoxy-2-propanol, , Ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, methyl propyl ketone and cyclohexanone, propylene glycol monopropyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl Ether-based solvents such as ether, diethylene glycol monomethyl ether, diethyl glycol monoethyl ether, diethyl glycol monopropyl ether, diethyl glycol monobutyl ether and diethylene glycol-2-ethylhexyl ether, benzene, toluene, Aromatic solvents such as rhenium, and the like may be used alone or in combination.

According to an embodiment of the present invention, the coating composition may further include organic fine particles or inorganic fine particles to improve the hardness of the drawn coating layer. The particle size of the organic or inorganic fine particles may be 10 mu m or less in terms of proper haze and coating thickness, more specifically 10 nm to 10 mu m, preferably 50 nm to 5 mu m, more preferably 100 nm to 3 mu m Lt; / RTI >

The organic fine particles or the inorganic fine particles are not limited as long as they are used for forming a coating layer.

The organic fine particles may be at least one selected from organic fine particles made of an acrylic resin, a styrene resin, an epoxy resin and a nylon resin.

More specifically, the organic fine particles may be at least one selected from the group consisting of methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl Acrylate, stearyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, n-octyl (meth) acrylate, Acrylates such as polyethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, glycidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl But are not limited to, methylstyrene, m-methylstyrene, p-ethylstyrene, m-ethylstyrene, p-chlorostyrene, m- chlorostyrene, p- chloromethylstyrene, m- chloromethylstyrene, styrenesulfonic acid, m-butoxystyrene, vinyl acetic acid (Meth) acrylonitrile, (meth) acrylonitrile, vinyltoluene, vinyltoluene, vinyltoluene, vinyl propionate, vinyl butyrate, vinyl ether, allyl butyl ether, allyl glycityl ether, (meth) acrylic acid, maleic acid, And (meth) acrylate, but the present invention is not limited thereto.

The organic fine particles may be selected from the group consisting of polystyrene, polymethyl methacrylate, polymethyl acrylate, polyacrylate, polyacrylate-co-styrene, polymethyl acrylate-co-styrene, polymethyl methacrylate- Polyvinyl chloride resin, polycarbonate resin, polyvinyl chloride resin, polybutylene terephthalate, polyethylene terephthalate, polyamide resin, polyimide resin, polysulfone, polyphenylene oxide, polyacetal, epoxy resin, phenol resin, silicone resin, melamine resin, One or more members selected from the group consisting of amine, polydivinylbenzene, polydivinylbenzene-co-styrene, polydivinylbenzene-co-acrylate, polydiallyl phthalate and triallyl isocyanurate polymer, A copolymer may be used, but the present invention is not limited thereto.

The inorganic fine particles may be at least one selected from the group consisting of inorganic fine particles of silicon oxide, titanium dioxide, indium oxide, tin oxide, zirconium oxide and aluminum oxide, but the present invention is not limited thereto.

The total content of the organic and inorganic fine particles may be in the range of 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the cationically curable coating composition. When the total content of the organic and inorganic fine particles is less than 0.1 part by weight based on 100 parts by weight of the cationically curable composition, the effect of improving the hardness and scratch resistance is insignificant. When the total content of the organic and inorganic fine particles is more than 20 parts by weight, The coating property becomes poor and the haze value due to the internal scattering becomes too large and the contrast ratio may be lowered.

Meanwhile, the coating composition of the present invention can be used in a wide range of applications such as surfactants, antioxidants, UV stabilizers, leveling agents, antifouling agents, antistatic agents, UV absorbers, antifoaming agents, It may further comprise an additive. The content can be varied within a range that does not deteriorate the physical properties of the coating composition of the present invention. Therefore, it may be included in an amount of about 0.1 to about 10 parts by weight based on 100 parts by weight of the total coating composition, have.

In one embodiment of the present application, a substrate film; And a coating layer provided on one surface or both surfaces of the base film, wherein the coating layer comprises a thermosetting resin; One or more additives selected from the group consisting of reactive or non-reactive silicone additives and reactive or non-reactive fluoric additives; And a thermal initiator, wherein at least one of the additives comprises a reactive silicon-based additive or a reactive fluorine-based additive.

In one embodiment of the present application, the thermosetting resin comprises an epoxy compound.

The weight average molecular weight of the epoxy compound may be 100 to 5,000 g / mol.

Wherein the epoxy compound is an alicyclic epoxy compound.

In one embodiment of the present application, the thermal initiator comprises a sulfonium salt or an iodonium salt.

In one embodiment of the present application, the polarizer protective film may further comprise a photoinitiator.

In one embodiment of the present application, the coating layer comprises, based on 100 parts by weight of the thermosetting resin, 0.1 to 10 parts by weight of the additive; And 0.01 to 5 parts by weight of the thermal initiator.

In one embodiment of the present application, the thickness of the coating layer is 50 nm or more and 10 m or less.

In still another embodiment, the thickness of the coating layer may be 50 nm or more and 9 占 퐉 or less, preferably 60 nm or more and 8 占 퐉 or less.

When the coating layer has the above-mentioned thickness range, it is possible to provide a polarizer protective film which is excellent in coating adhesion to the base film and has excellent coating-breaking property and diffusing plate-breaking property. Also, when the coating layer has the above-mentioned thickness range, the curing speed is increased, and the surface hardness can be improved and the breaking performance can be further improved. As described above, the polarizer protective film can be manufactured in a thin shape and exhibits sufficient strength. In addition, even a single coating layer can exhibit sufficient hardness and scratch resistance, and exhibits high adhesiveness to a substrate without a primer layer, so that workability and productivity of the manufacturing process are high.

According to an embodiment of the present application, Applying a coating composition according to one embodiment of the present application on at least one side of a substrate film; And a step of stretching the base film coated with the coating composition.

The method of applying the coating composition is not particularly limited as long as it can be used in the technical field to which the present technology belongs. Examples of the coating method include bar coating method, knife coating method, roll coating method, blade coating method, die coating method, micro gravure coating method , A comma coating method, a slot die coating method, a lip coating method, or a solution casting method.

In one embodiment of the present application, the stretching ratio in the step of stretching the base film is 1.05 to 10 times the length in the stretching direction.

In one embodiment of the present application, the stretching temperature in the step of stretching the base film may be 100 占 폚 or more and 180 占 폚 or less, preferably 110 占 폚 or more and 160 占 폚 or less, more preferably 120 占 폚 or more and 140 占 폚 or less .

In the production method according to one embodiment of the present application, the coating composition according to one embodiment of the present application includes a curing agent so that curing can be induced in the drawing process within the range of temperature without a specific curing process, And the curing of the coating composition is simultaneously carried out in the drawing step.

That is, after the stretching process, a thermosetting process or a UV irradiation process is not added, so that the process cost can be further reduced.

In one embodiment of the present application, the method further comprises a step of stretching the base film before the step of applying the coating composition on one side of the base film.

The coating can be minimized by coating the substrate film before the final step through the step of uniaxially stretching the base film before the step of applying the coating composition so that the roll film can be prevented from being contaminated with the roll.

When the base film is uniaxially stretched before application of the coating composition, it is preferable that the stretching direction after the coating is stretched in the direction perpendicular to the stretching direction before coating the coating composition. For example, if the base film is stretched in the MD direction before application of the coating composition, it may be stretched in the width direction (TD) after application of the coating composition.

When the coating composition is stretched before and after coating, the total stretching ratio is at least 1.1 times, or at least 1.2 times, or at least 1.5 times, at least 25 times, or at most 10 times the total stretching area of the substrate film, Fold or less, or 7 times or less. When the stretching ratio is less than 1.1 times, the effect of stretching may not be sufficiently achieved, and when the stretching ratio is more than 25 times, the coating layer may be cracked.

Before the stretching, the coating surface of the coating composition may be planarized and dried to volatilize the solvent contained in the coating composition.

The polarizer protective film of the present invention is used for protecting the polarizer from the outside, and at least one surface of the polarizer , Preferably as a lower protective film of the polarizer.

On the other hand, as the liquid crystal display device becomes larger and slimmer, a sagging phenomenon of the lower polarizer plate occurs, and the lower protective film of the lower polarizer plate comes into contact with the backlight unit, causing scratches.

Accordingly, the polarizer protective film obtained by the production method of the present invention exhibits excellent physical properties such as scratch resistance and hardness due to the stretched coating layer, thereby effectively protecting the lower polarizer, and being applicable to a polarizer for a liquid crystal display device .

The base film is not particularly limited, but may be a polyester, a polyethylene, a cyclic olefin polymer (COP), a cyclic olefin copolymer (COC), a polyacrylate , PAC), polycarbonate (PC), polymethylmethacrylate (PMMA), polyimide (PI), or cellulose.

The thickness of the base film is not particularly limited, but a film having a thickness of about 50 to 1,000 占 퐉, specifically 100 to 500 占 퐉 may be used in consideration of the subsequent stretching process.

The method for forming the base film is not particularly limited, and an unstretched base film can be prepared by a suitable film forming method such as a solution casting method, a melt extrusion method, a calendering method, and a compression molding method.

When the base film is stretched, if the polymer is rearranged in the stretching process and a functional coating layer or the like is further formed on the stretched base film, there is a problem that the adhesion is reduced. Therefore, there is a method of adding a separate process such as forming a primer layer for securing adhesion or adding a functional compound capable of improving adhesion to the coating layer. In this case, a separate process is added in the manufacturing process, There is a problem in that the development of universal primers is difficult due to physical and chemical properties of each film. Further, adding a functional compound to the coating layer may also cause a problem of cost increase and other property deterioration.

Accordingly, the present invention has been made to solve the above problems, and it is possible to provide a polarizer protective film having sufficient scratch resistance and thinness even without a separate primer layer according to an embodiment of the present invention.

According to one embodiment of the present invention, the base film can apply the coating composition on one side thereof in an unstretched state.

In another embodiment, the substrate film may be subjected to uniaxial stretching prior to application of the coating composition.

At this time, the stretching direction is not particularly limited, and it may be stretched in the width direction (TD) direction or the length (MD) direction, and may be uniaxially stretched or biaxially stretched. The stretching ratio can be stretched so as to be 1.1 times or more, 1.2 times or 1.5 times or more, 5 times or less, or 3 times or less based on the length in the stretching direction.

The coating composition for a polarizer protective film according to one embodiment of the present application is applied on at least one side of the unstretched or uniaxially stretched base film.

Generally, in order to form a functional coating layer such as a hard coating layer on a polarizer protective film, a method of applying a coating composition on a base film, drying and curing it is used. However, in the case of the base film, since the polymer is rearranged in the stretching process, there is a problem that the coating layer does not adhere well to the base film. There is a method of forming a primer layer in order to ensure adhesion, however, there is a problem that productivity is lowered due to the addition of a separate step in the manufacturing process, and there is a problem that development of a general purpose primer is difficult.

According to the production method of the present invention, the coating composition is applied onto the base film and simultaneously stretched and cured to form a coating layer, whereby adhesion to the stretched base film is high without requiring a separate primer layer, It is possible to provide a polarizer protective film as much as possible.

On the other hand, when the coating composition is too rigid, there is a problem that the coating layer becomes uneven or the drawing is not performed properly in the drawing process after coating. On the contrary, when the coating composition is flexible and the drawing rate is too high, And scratch resistance can not be ensured.

Therefore, in order to exhibit sufficient scratch resistance after a uniform stretching process and curing, it is important to appropriately adjust the flexibility and strength of the coating composition in addition to the control of the draw ratio of the base film.

Thus, according to the production method of the present invention, it is possible to provide a polarizer protective film that satisfies the above-mentioned requirements by optimizing the composition of the coating composition and the stretching process.

The coating layer may be formed on only one side of the base film, or may be formed on both sides of the base film.

When the coating layer is formed only on one side of the stretched base film, the other side may further include another photocurable coating layer and / or a thermosetting coating layer or other layers, films, or films for imparting functionality have. It is also possible to further form another functional layer on the coating layer.

As such, when the protective film of the present invention includes another layer, film or film or the like on the other surface of the stretched base film, the forming method and the step are not limited. For example, a method of coating the base film before stretching and curing after stretching, a method of coating and curing after stretching the base film, a method of coating a layer, a film, or a film formed separately using an adhesive, Film or film may be laminated on the other surface of the stretched substrate film by various methods known in the art, such as a method of laminating the stretched substrate film to the substrate.

The polarizer protective film of the present invention is obtained by connecting a sample to a vibration generator and superimposing the sample and the diffusion sheet in contact with each other so that the vibration is applied for a predetermined time in a state of applying a load and then checking the surface of the polarizer protective film, Can be evaluated.

Further, the polarizer protective film obtained by the production method of the present invention may have a pencil hardness of H or higher at a load of 500 g.

In one embodiment of the present application, a polarizer; And a polarizer protective film according to an embodiment of the present application on at least one side of the polarizer.

At this time, the polarizer is not particularly limited, and a film made of polyvinyl alcohol (PVA) including a polarizer well-known in the related art, for example, iodine or a dichroic dye, is used.

The polarizer vibrates in various directions and exhibits a characteristic of extracting only light vibrating in one direction from the incident light. This property can be achieved by stretching polyvinyl alcohol (PVA) absorbing iodine with a strong tension. For example, more specifically, there is a method comprising swelling a PVA film by swelling in an aqueous solution, dyeing the swollen PVA film with a dichroic material imparting polarizing properties, stretching the dyed PVA film, ) To align the dichroic dye materials in the stretching direction, and a polarizing step for correcting the color of the PVA film after the stretching step. However, the polarizing plate of the present invention is not limited thereto.

According to an embodiment of the present invention, the polarizer protective film may be attached to both surfaces of the polarizer.

When the polarizer protective film of the present invention is laminated on the polarizer and adhered, it is preferable that the base film is attached to the polarizer.

According to another embodiment of the present invention, the polarizer protective film is provided on only one side of the polarizer, and the general protective film commonly used for protecting the polarizer may be provided on the other side.

At this time, the polarizing plate can be used as a lower polarizing plate of an LCD, and the polarizing plate protective film of the present invention can be positioned at a lower position in a laminated structure in an LCD.

As described above, when the polarizer protective film is laminated on the LCD and the polarizer is laminated on the LCD, the lower protective film of the polarizer is damaged by abutting against the backlight unit provided under the polarizer, thereby preventing the haze from increasing, have.

The polarizer and the polarizer protective film can be bonded by lamination using an adhesive or the like. Usable adhesives are not particularly limited as long as they are known in the art. For example, a water-based adhesive, a one-component or two-component polyvinyl alcohol (PVA) adhesive, a polyurethane adhesive, an epoxy adhesive, a styrene butadiene rubber adhesive (SBR adhesive), a hot melt adhesive, The present invention is not limited to these examples.

When the polarizer protective film of the present invention is laminated on the polarizer and adhered to the polarizer, it is preferable that the stretched coating layer is laminated so as to be attached to the polarizer on the surface on which the stretched coating layer is not formed and the stretched coating layer is positioned outside the polarizer.

The polarizing plate having the polarizer protective film of the present invention is applied to an LCD, but the present invention is not limited thereto and can be used in various fields. For example, mobile communication terminals, smart phones, other mobile devices, display devices, electronic blackboards, outdoor electronic signboards, and various displays. According to an embodiment of the present invention, the polarizing plate may be a TN (Twisted Nematic) or STN (Super Twisted Nematic) liquid crystal polarizing plate, and may be an IPS (In-Plane Switching), a Super-IPS, a Fringe Field Switching Or a polarizing plate for the vertical alignment mode.

In one embodiment of the present application, a liquid crystal cell; An upper polarizer provided on an upper portion of the liquid crystal cell; A lower polarizer disposed on a lower portion of the liquid crystal cell; And a backlight unit provided on a lower portion of the lower polarizer, wherein the lower polarizer comprises a polarizer; And a polarizer protective film according to an embodiment of the present application disposed on one side or both sides of the polarizer.

In one embodiment of the present application, the polarizer protective film is disposed to face the backlight unit.

1 is a diagram showing a liquid crystal display device including a polarizer protective film obtained by the production method of the present invention.

The backlight unit includes a light source that emits light from the back surface of the liquid crystal panel. The type of the light source is not particularly limited, and a general LCD light source such as CCFL, HCFL, or LED can be used.

Best Mode for Carrying Out the Invention Hereinafter, the function and effect of the present invention will be described in more detail through specific examples of the present invention. It is to be understood, however, that these embodiments are merely illustrative of the invention and are not intended to limit the scope of the invention.

< Example >

Preparation of coating compositions

Table 1 below shows the composition and content of the coating composition according to the present invention. A coating composition was prepared according to the composition and contents shown in Table 1 below.

Suzy Initiator additive Kinds content Kinds content Kinds content Production Example 1 S-28 100 SIB3 0.1 X-22-169B
+
TEGO RAD 2100 0.5
+
0.5 Production Example 2 S-28 100 SIB3 0.1 X-22-170DX
+
TEGO RAD 2100 0.5
+
0.5 Production Example 3 S-28 100 SIB3 0.1 X-22-4039
+
TEGO RAD 2100 0.5
+
0.5 Production Example 4 S-28 100 SIB3 0.1 X-22-169B 0.5 Production Example 5 S-28 100 SIB3 0.1 X-22-170DX 0.5 Production Example 6 S-28 100 SIB3 0.1 X-22-4039 0.5 Production Example 7 S-28 100 SIB3 + CPI-100p 0.1 + 2.0 Fluorosil
OH ACR C7-F 0.5 Production Example 8 S-28 100 SIB3 + CPI-100p 0.1 + 2.0 MEGAFACE RS-56 0.5 Production Example 9 S-28 100 SIB3 0.1 TEGO RAD 2100 1.0 Production Example 10 S-28 100 SIB3 0.1 TEGO RAD 2200N 1.0 Production Example 11 S-28 100 CPI-100p 2.0 TEGO RAD 2100 1.0

S-28 used as a resin in Table 1 was a resin of an alicyclic epoxy compound as a cationic thermosetting resin, and SI-B3 (benzyl (4- hydroxyphenyl) methylsulfonium and tetrakis (pentafluorophenyl) borate (1: 1) were used as the photoinitiator and CPI-100p (Diphenyl [(phenylthio) phenyl] sulfonium hexafluorophosphate (1-) was used as the photoinitiator.

In Table 1, X-22-169B, X-22-170DX, X-22-4039, X-22-169B, X-22-170DX and X-22-4039 are reaction type silicon- ACR C7-F and MEGAFACE RS-56 were used as reactive fluorinated additives from Siltech and DIC, respectively.

In Table 1 above, TEGO RAD 2100 and TEGO RAD 2200N were used as non-reactive silicone additives for TEGO.

Polarizer  Manufacture of protective film

Example  One.

The polymethyl methacrylate resin was subjected to a T-die-peeling process under the condition of 250 占 폚 to prepare an undrawn film having a width of 800 mm and a thickness of 200 占 퐉. The unstretched film was stretched 1.8 times in the length (MD) direction at a temperature of 135 캜 to prepare a uniaxially stretched film.

The coating composition of Production Example 1 was coated on the uniaxially stretched film by bar coating method and then stretched 2.5 times in the width direction (TD) at a temperature of 135 ° C to form a coating layer having a thickness of 2 μm. A protective film was prepared.

Example  2.

A polarizer protective film was prepared in the same manner as in Example 1, except that the coating composition of Production Example 2 was used in place of the coating composition of Production Example 1.

Example  3.

A polarizer protective film was prepared in the same manner as in Example 1, except that the coating composition of Production Example 3 was used in place of the coating composition of Production Example 1.

Example  4.

A polarizer protective film was prepared in the same manner as in Example 1, except that the coating composition of Production Example 4 was used in place of the coating composition of Production Example 1.

Example  5.

A polarizer protective film was prepared in the same manner as in Example 1, except that the coating composition of Production Example 5 was used in place of the coating composition of Production Example 1.

Example  6.

A polarizer protective film was prepared in the same manner as in Example 1, except that the coating composition of Production Example 6 was used in place of the coating composition of Production Example 1.

Example  7.

The polymethyl methacrylate resin was subjected to a T-die-peeling process under the condition of 250 占 폚 to prepare an undrawn film having a width of 800 mm and a thickness of 200 占 퐉. The unstretched film was stretched 1.8 times in the length (MD) direction at a temperature of 135 캜 to prepare a uniaxially stretched film.

The coating composition of Preparation Example 7 was coated on the uniaxially stretched film by bar coating method and then stretched 2.5 times in the width direction (TD) at a temperature of 135 ° C. Thereafter, a UV lamp (H or D bulb) was used to cure at about 500 Mj to prepare a polarizer protective film having a coating layer having a thickness of 2 탆.

Example  8.

A polarizer protective film was prepared in the same manner as in Example 7 except that the coating composition of Production Example 8 was used in place of the coating composition of Production Example 7. [

Comparative Example  One.

A polarizer protective film was prepared in the same manner as in Example 1, except that the coating composition of Production Example 9 was used in place of the coating composition of Production Example 1.

Comparative Example  2.

A polarizer protective film was prepared in the same manner as in Example 1, except that the coating composition of Production Example 10 was used in place of the coating composition of Production Example 1.

Comparative Example  3.

A polarizer protective film was prepared in the same manner as in Example 1, except that the coating composition of Production Example 11 was used in place of the coating composition of Production Example 1.

< Experimental Example >

<Measurement method>

The properties of the polarizer protective film of the examples were measured by the following methods.

1) Surface Hardness

A standard pencil (Mitsubishi) was changed from 6B to 9H under a load of 500 g according to ASTM 3363-74, and the surface of the coating layer was scratched by keeping the angle of 45 degrees.

After three measurements, the surface damage was judged and the measured value was described as an average value.

H is the level of pencil hardness.

2) Extraction of additive

After the sample is prepared, it is judged that the additive has eluted when the surface is rubbed off with no spots and when stains or marks are generated.

In Table 2 below, when the additive is eluted, it is labeled "Elution" and when it is not eluted it is marked "O".

3) Coating property

In the following Table 2, "OO" means a state in which the coating is very good, and "O" means in the case where the coating property is good.

4) Surface hardness

If the surface is viscous after coating curing, it is judged to be uncured, and if there is no viscosity, it is judged to be cured. In Table 2, "O" means that the surface is not viscous after curing and "X" means that the surface is viscous after curing.

5) Characteristics

The exciter is a part of a vibration tester and is used mainly for durability evaluation by applying vibration to the structure. It is possible to apply vibration of a specific intensity or frequency and to apply vibration at any frequency within a specified range. The evaluation method is as follows.

- Assessment Methods

Sample / diffusion plate / jig. At this time, the oscillator and the sample are fixed, and the diffuser plate and the jig are fixed or not.

Apply a load of 100g ~ 300g including the jig, and apply vibration of 2V, frequency 20 ~ 60Hz, 240sec.

The surface of the sample and the diffuser plate is visually observed to evaluate the crush strength.

As a result of the measurement of the fracture characteristics, "OO" represents a case where the fracture property is very excellent, "O" represents an excellent case, and "X"

The results of the physical properties measurement are shown in Table 2 below.

Surface hardness Extraction of additive Coating property Surface hardness Shattering Characteristics Example 1 H ○ Xx ○ Xx Example 2 H ○ Xx ○ ○ Example 3 H ○ Xx ○ ○ Example 4 H ○ ○ ○ ○ Example 5 H ○ ○ ○ ○ Example 6 H ○ ○ ○ ○ Example 7 H ○ ○ ○ Xx Example 8 H ○ ○ ○ Xx Comparative Example 1 H Dissolution - ○ X Comparative Example 2 H Dissolution - X ○ Comparative Example 3 Less than H Dissolution ○ ○ X

As can be seen from the above Table 2, Examples 1 to 8 containing at least one reactive type additive were improved in terms of additive dissolution as compared with Comparative Examples 1 to 3 using non-reactive additive. It was also confirmed that the flame retardant properties were improved particularly in Examples 7 and 8 using the fluorine-based reactive additive and the heat initiator and the photoinitiator at the same time.

In the case of Comparative Example 3, only the photoinitiator was used as the initiator. Compared with Examples 1 to 6 using the heat initiator, the use of the thermal initiator was effective in reducing the process cost because curing occurred in the drawing process itself, And the surface hardness was excellent.

10: Upper polarizer
20: liquid crystal cell
30: Lower polarizer plate
34: polarizer protective film
40: Backlight unit

Claims (22)

A base film; And
A polarizer protective film comprising a coating layer provided on one side or both sides of the base film,
Wherein the coating layer comprises a thermosetting resin; One or more additives selected from the group consisting of reactive or non-reactive silicone additives and reactive or non-reactive fluoric additives; And a thermal initiator,
Wherein at least one of the additives includes the reactive silicon-based additive or the reactive fluorine-based additive. The method according to claim 1,
Wherein the thermosetting resin comprises an epoxy compound. The method of claim 2,
Wherein the weight average molecular weight of the epoxy compound is 100 to 5,000 g / mol. The method of claim 2,
Wherein the epoxy compound is an alicyclic epoxy compound. The method according to claim 1,
Wherein the coating layer further comprises a photoinitiator. The method according to claim 1,
Wherein the thermal initiator comprises a sulfonium salt or an iodonium salt. The method according to claim 1,
Wherein the thickness of the coating layer is 50 nm or more and 5 占 퐉 or less. The method according to claim 1,
Wherein the coating layer contains, relative to 100 parts by weight of the thermosetting resin,
0.1 to 10 parts by weight of the additive; And
And 0.01 to 5 parts by weight of the thermal initiator. Thermosetting resin;
One or more additives selected from the group consisting of reactive or non-reactive silicone additives and reactive or non-reactive fluoric additives; And
With a coating composition comprising a thermal initiator,
Wherein at least one of the additives comprises the reactive silicon-based additive or the reactive fluorine-based additive. The method of claim 9,
Wherein the thermosetting resin comprises an epoxy compound. The method of claim 10,
Wherein the weight average molecular weight of the epoxy compound is 100 to 5,000 g / mol. The method of claim 10,
Wherein the epoxy compound is an alicyclic epoxy compound. The method of claim 9,
&Lt; / RTI &gt; further comprising a photoinitiator. The method of claim 9,
Wherein the thermal initiator comprises a sulfonium salt or an iodonium salt. The method of claim 9,
The coating composition contains, per 100 parts by weight of the thermosetting resin,
0.1 to 10 parts by weight of the additive; And
0.01 to 5 parts by weight of the thermal initiator. Preparing a base film;
Applying the coating composition of any one of claims 9 to 15 on at least one side of the substrate film; And
And stretching the base film to which the coating composition is applied. 18. The method of claim 16,
Wherein the stretching ratio in the step of stretching the base film is 1.05 to 10 times the length in the stretching direction. 18. The method of claim 16,
Wherein the stretching temperature in the step of stretching the base film is 100 占 폚 or more and 180 占 폚 or less. 18. The method of claim 16,
Further comprising a step of stretching the base film before applying the coating composition on at least one side of the base film. A polarizer; And
And a polarizer protective film according to any one of claims 1 to 8 on at least one surface of the polarizer. A liquid crystal cell;
An upper polarizer provided on an upper portion of the liquid crystal cell;
A lower polarizer disposed on a lower portion of the liquid crystal cell; And
And a backlight unit provided on a lower portion of the lower polarizer plate,
Wherein the lower polarizer comprises a polarizer; And a polarizer protective film according to any one of claims 1 to 8 disposed on one side or both sides of the polarizer. 23. The method of claim 21,
And the polarizer protective film is disposed to face the backlight unit.

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