TW201500487A - Photocurable coating composition, coating film and polarizing plate using the same - Google Patents

Abstract

The present invention provides a photocurable coating composition having a storage modulus (G') of 4.0E+07 to 7.0E+07 Pa, a coating film formed using the photocurable coating composition, and a polarizing plate or a display device including the coating film. The coating film formed using the photocurable coating composition of the present invention shows excellent crack, optical and mechanical properties, and can be used as a protective film of the polarizing plate.

Description

Photocurable coating composition, coating film and polarizing plate using the same

The present invention relates to a photocurable coating composition, a coating film, a polarizing plate, and a display device using the same. In particular, the present invention provides a photocurable coating composition which can be used to produce a coating film exhibiting excellent crack, optical and mechanical properties, a coating film formed using the photocurable coating composition, and a polarizing film including the coating film Board or display device.

The polarizing film is generally used in a display device such as a liquid crystal display, an electroluminescence (EL) display, a plasma display (PD), and a field emission display (FED), and is adsorbed on a polyvinyl alcohol-based resin film. It is produced by orienting a dichroic colorant such as iodine or a dichroic dye. The polarizing film may be coated on the adhesive layer on at least one side thereof, and then a protective film containing triacetyl cellulose (TAC) or the like may be attached to the adhesive layer to form a polarizing plate for a liquid crystal display or the like.

The polarizing plate may include a coating film (for example, a hard coating film, an anti-glare film, and an anti-reflection film) to improve the properties of the polarizing plate. The coating film preferably has high transparency, low haze, high hardness, good scratch resistance, and no cracking during the process or after the process.

Korean Patent Publication No. 10-1127952 discloses an optical hard coat film which exhibits improved flexibility and optical and mechanical properties. The disclosed optical hard coat film is composed of a substrate layer or substrate of a transparent plastic film and a hard coat layer on at least one side of the substrate layer. The hard coat layer comprises a cured UV curable resin composition, and the UV curable resin composition contains two or more functional groups of ethylene glycol-containing acrylate monomers, polyfunctional acrylate monomers, and polyfunctional urethane groups. At least one of the ester acrylate oligomers and the cerium oxide microparticles. However, the disclosed optical hard coat film has a problem in that its physical properties are degraded on the acrylic film substrate.

SUMMARY OF THE INVENTION An object of the present invention is to provide a photocurable coating composition which can be used to produce a coating film which exhibits excellent crack, optical and mechanical properties even when an acrylic film substrate is used.

Another object of the present invention is to provide a coating film formed using the photocurable coating composition.

Another object of the present invention is to provide a polarizing plate comprising the coating film.

Another object of the present invention is to provide a display device including the coating film.

The present invention provides a photocurable coating composition having a storage modulus (G') of from 4.0E+07 to 7.0E+07 Pa.

The present invention further provides a coating film comprising a coating layer comprising a cured product of a photocurable coating composition on at least one side of a transparent substrate.

The present invention further provides a polarizing plate comprising the coating film.

The present invention further provides a display device including the coating film.

The coating film formed using the photocurable coating composition of the present invention has good crack properties, high transparency, low haze, high hardness, and good scratch resistance. Therefore, the coating film can be effectively used as a protective film for a polarizing plate.

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The invention is illustrated in more detail below.

One embodiment of the present invention relates to a photocurable coating composition having a storage modulus (G') of from 4.0E+07 to 7.0E+07 Pa.

In the present invention, the storage modulus (G') is measured in a state in which the photocurable coating composition is semi-hardened. Specifically, it is measured before UV light irradiation is about to be completed before the light curable coating composition is irradiated with UV light until the hardening of the composition is about to be completed. In the present invention, the method of measuring the storage modulus (G') of the photocurable coating composition is not specifically limited. For example, it can be measured by the method presented in the experimental examples described below.

In one embodiment of the present invention, the storage modulus (G') of the semi-hardenable photocurable coating composition is adjusted to a range of 4.0E+07 to 7.0E+07 Pa to be modified from the photocurable coating. The crack, optical and mechanical properties of the coating film formed by the composition.

In one embodiment of the present invention, the photocurable coating composition may comprise a plurality of components as long as the composition has a storage modulus (G') of 4.0E+07 to 7.0E+07 Pa.

In one embodiment of the invention, the photocurable coating composition can include a photocurable (meth) acrylate oligomer.

The photocurable (meth) acrylate oligomer may be one or more selected from the group consisting of epoxy (meth) acrylate, urethane (meth) acrylate, and polyester ( Methyl) acrylate. For example, the photocurable (meth) acrylate oligomer may comprise a mixture of urethane (meth) acrylate and polyester (meth) acrylate, or two polyesters (methyl) a mixture of acrylates.

The urethane (meth) acrylate can be produced by reacting a polyfunctional (meth) acrylate having a hydroxyl group with a compound having an isocyanate group in the presence of a catalyst according to a method known in the art. Examples of the polyfunctional (meth) acrylate having a hydroxyl group may be one or more selected from the group consisting of 2-hydroxyethyl (meth) acrylate, 2-hydroxyisopropyl (meth) acrylate Ester, 4-hydroxybutyl (meth) acrylate, caprolactone ring-opening hydroxy acrylate, pentaerythritol tri/tetra (meth) acrylate mixture and dipentaerythritol penta/hexa (methyl) Acrylate mixture. Also, examples of the compound having an isocyanate group may be one or more selected from the group consisting of 1,4-diisocyanatobutane, 1,6-diisocyanatohexane, 1,8- Diisocyanatooctane, 1,12-diisocyanatodecane, 1,5-diisocyanate Root-2-methylpentane, trimethyl-1,6-diisocyanatohexane, 1,3-bis(isocyanatomethyl)cyclohexane, trans-1,4-cyclohexene Diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), isophorone diisocyanate, toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, xylene-1,4- Diisocyanate, tetramethylxylene-1,3-diisocyanate, 1-chloromethyl-2,4-diisocyanate, 4,4'-methylenebis(2,6-dimethylphenylisocyanate) 4,4'-oxybis(phenylisocyanate), a trifunctional isocyanate derived from hexamethylene diisocyanate and a trimethane propanol adduct of toluene diisocyanate.

The polyester (meth) acrylate can be produced by reacting a polyester polyol with acrylic acid according to methods known in the art. For example, the polyester (meth) acrylate may be, but is not limited to, one or more selected from the group consisting of polyester acrylate, polyester diacrylate, polyester tetraacrylate, polyester hexa Acrylate Ester, polyester pentaerythritol triacrylate, polyester pentaerythritol tetraacrylate and polyester pentaerythritol hexaacrylate.

The photocurable coating composition of the present invention may comprise a photocurable (meth) acrylate oligomer in an amount of from 92 to 99 parts by weight, based on 100 parts by weight of the solids of the photocurable coating composition. If the photocurable coating composition comprises an amount of less than 92 parts by weight of the oligomer, cracking may occur due to excessive hardening. If the photocurable coating composition comprises an amount of oligomers greater than 99 parts by weight, the physical properties may be lowered by uncured.

The photocurable coating composition according to one embodiment of the present invention may comprise a mixture of a tetrafunctional polyester (meth) acrylate and a hexafunctional polyester (meth) acrylate or a tetrafunctional polyester (meth) acrylate. A mixture with a tetra-hexafunctional urethane (meth) acrylate is used as a photocurable (meth) acrylate oligomer.

The photocurable coating composition may include a tetrafunctional polyester (meth) acrylate in an amount of 20 to 50 parts by weight based on 100 parts by weight of the solid of the photocurable coating composition. If the photocurable coating composition comprises less than 20 parts by weight of the tetrafunctional polyester (meth) acrylate, the crack properties can be reduced, and if the photocurable coating composition comprises more than 50 parts by weight Functional polyester (meth) acrylate, mechanical properties reduce.

Likewise, the photocurable coating composition may comprise from 45 to 75 parts by weight, based on 100 parts by weight of the solids of the photocurable coating composition, of a hexafunctional polyester (meth) acrylate. If the photocurable coating composition comprises less than 45 parts by weight of hexafunctional polyester (meth) acrylate, the mechanical properties may be reduced, and if the photocurable coating composition comprises more than 75 parts by weight Functional polyester (meth) acrylate, the crack properties can be reduced.

In addition, the photocurable coating composition may comprise from 45 to 85 parts by weight, based on 100 parts by weight of the solids of the photocurable coating composition, of four to six functional urethane (meth) acrylates. ester. If the photocurable coating composition comprises less than 45 parts by weight of the tetra- to hexafunctional urethane (meth) acrylate, the mechanical properties can be reduced, and if the photocurable coating composition comprises more than 85 weight The fraction of the four to hexafunctional urethane (meth) acrylate can reduce the crack properties.

The photocurable coating composition according to one embodiment of the present invention may include a photocurable monomer.

As the photocurable monomer, any monomer having an unsaturated group (for example, (meth)acrylonitrile group, vinyl group, styryl group, and allyl group) as a photocurable functional group known in the art can be used. According to one embodiment, a monomer having a (meth) acrylonitrile group can be used.

For example, the monomer having a (meth) acrylonitrile group may be, but not limited to, one or more selected from the group consisting of neopentyl glycol acrylate, 1,6-hexanediol (A) Acrylate, propylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol Di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, 1,2,4-cyclohexanetetra(meth)acrylic acid Ester, pentapolyglycerol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, Dipentaerythritol penta (meth) acrylate, two new Pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth) acrylate, tripentyltetraol tri(meth) acrylate, tripentenol hexa(meth) acrylate, Bis(2-hydroxyethyl)isocyanurate di(meth)acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate , isooctyl (meth) acrylate, isodecyl (meth) acrylate, stearyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, phenoxy ethyl (methyl Acrylate and isodecyl (meth) acrylate.

In one embodiment where the photocurable (meth) acrylate oligomer comprises a mixture of a tetrafunctional polyester (meth) acrylate and another (meth) acrylate, a certain amount of the other (methyl) The acrylate can be replaced by a photocurable monomer. In this case, the resulting photocurable coating composition can have improved processability and compatibility and equivalent properties.

The photocurable coating composition according to one embodiment of the present invention may optionally include a photoinitiator and a solvent.

Any photoinitiator known in the art can be used without limitation. In particular, the photoinitiator may be one or more selected from the group consisting of hydroxyketones, aminoketones, and hydrogen recapture types.

For example, the photoinitiator may be one or more selected from the group consisting of 2-methyl-1-[4-(methylthio)phenyl]2-morpholinylacetone-1, two Phenyl ketone, benzyl dimethyl ketal, 2-hydroxy-2-methyl-1-phenyl-1-one, 4-hydroxycyclophenyl ketone, 2,2-dimethoxy-2-benzene Acetophenone, anthracene, anthracene, triphenylamine, carbazole, 3-methylacetophenone, 4-chloroacetophenone, 4,4-dimethoxyacetophenone, 4,4-diamine Diphenyl ketone, 1-hydroxycyclohexyl phenyl ketone, diphenyl ketone and diphenyl (2,4,6-trimethylbenzylidene) phosphine oxide.

The photoinitiator may be contained in the photocurable coating composition in an amount of from 0.05 to 10 parts by weight based on 100 parts by weight of the photocurable coating composition. If the amount of the photoinitiator is less than 0.05 parts by weight, the curing rate of the composition is slowed down and the composition is not completely cured, whereby mechanical properties can be lowered. If the amount of the photoinitiator is more than 10 parts by weight, the crack of the composition may occur due to excessive hardening of the composition.

Any solvent known in the art can be used without limitation in the present invention. For example, the solvent may be a ketone such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and diacetone alcohol; an ester such as methyl formate, methyl acetate, ethyl acetate, lactate B Esters and butyl acetate; nitrogen-containing compounds such as nitromethane, N-methylpyrrolidone and N,N-dimethylformamide; ethers such as diisopropyl ether, tetrahydrofuran, dioxane and Oxolane; halogenated hydrocarbons such as dichloromethane, chloroform, trichloroethane and tetrachloroethane; other solvents such as dimethyl hydrazine, propylene carbonate and 2-methoxyethanol. One of the above solvents or a mixture of at least two may be used. For example, the solvent may be one or more selected from the group consisting of methyl acetate, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and 2- Methoxyethanol.

The solvent may be contained in the photocurable coating composition of the present invention in an amount of from 0.1 to 85 parts by weight based on 100 parts by weight of the photocurable coating composition. If the amount of the solvent is less than 0.1 part by weight, the processability of the composition may be lowered due to high viscosity, and if the amount of the solvent is more than 85 parts by weight, the drying and curing process may take a longer time.

The photocurable coating composition according to one embodiment of the present invention may optionally include other components known in the art, such as antioxidants, UV absorbers, light stabilizers, thermal polymerization inhibitors, leveling agents, surfactants, Lubricants and antifouling agents.

One embodiment of the present invention relates to a coating film formed using the above photocurable coating composition. The coating film according to one embodiment of the present invention may comprise a transparent substrate; and a coating formed on one or both sides of the transparent substrate and comprising a cured product of the photocurable coating composition.

The transparent substrate can be any transparent plastic film. For example, the transparent substrate may be selected from the group consisting of a cyclic olefin derivative having a monomer unit containing a cyclic olefin (for example, a norbornene or a polycyclic norbornene monomer), cellulose (diacetyl cellulose, three Ethylcellulose, Ethylcellulose Butyrate, Isobutyl Cellulose, Propylene Cellulose, Butylcellulose, Ethyl Acetate Cellulose, Ethylene Vinyl Acetate Copolymer, Polyester, Poly Styrene, polyamine, polyether Yttrium, polypropylene, polyimine, polyether, polyfluorene, polyethylene, polypropylene, polymethylpentane, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetal , polyether ketone, polyether ether ketone, polyether oxime, polymethyl methacrylate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate , polyurethane and epoxy resin. Further, the transparent substrate can be a film that is unoriented or uniaxially or biaxially oriented.

In one embodiment of the present invention, the transparent substrate may be a uniaxially or biaxially oriented polyester film having high transparency and heat resistance; a cyclic olefin derivative film having high transparency and heat resistance and corresponding to the film Magnification; triacetyl cellulose film, which has transparency and no optical anisotropy; or an acrylic copolymer film, which has high transparency and low price.

The thickness of the transparent substrate is not limited, but it may be 8 to 1000 μm, especially 20 to 150 μm. If the thickness of the transparent substrate is less than 8 μm, the film strength is lowered, so that handleability is deteriorated. If the thickness of the transparent substrate is more than 1000 μm, the transparency may be lowered or the weight of the polarizing plate may be higher.

The coating film according to one embodiment of the present invention can be produced by applying a coating formed by applying a photocurable coating composition on one side or both sides of a transparent substrate and curing the applied composition.

The photocurable coating composition according to one embodiment of the present invention can be applied to a transparent substrate using methods known in the art, such as die coaters, air knives, reverse rolls, spray coating, knife coating, casting, gravure Coating, micro gravure coating and spin coating.

After the photocurable coating composition is applied to the transparent substrate, it can be dried by vaporizing the volatile material at 30 to 150 ° C for 10 seconds to 1 hour or 30 seconds to 30 minutes, and then by using UV Light is irradiated to cure. The dose of UV light can be, for example, from about 0.01 to 10 J/cm ² or from about 0.1 to ² J/cm ² .

The thickness of the coating to be formed may be, for example, 2 to 30 μm or 3 to 15 μm. In this case, a coating having excellent hardness properties can be obtained.

One embodiment of the present invention relates to a polarizing plate comprising the above coating film. According to this issue The polarizing plate of one embodiment can be produced by laminating a coating film on at least one side of the polarizing film.

For example, the polarizing film may include, but is not limited to, two-color adsorption such as iodine or dichroic dye on a hydrophilic polymer film such as a polyvinyl alcohol film and a partially hydrolyzed ethylene-vinyl acetate copolymer film. The uniaxially oriented film produced by the material, and the oriented polyene film (for example, dehydrated polyvinyl alcohol and dehydrochlorinated polyvinyl chloride). One embodiment of the polarizing film may include a polyvinyl alcohol film and a two-color material such as iodine. The thickness of the polarizing film may be, but is not limited to, about 5 to 80 μm.

One embodiment of the present invention relates to a display device having the above coating film. The display device may include a polarizing plate having the coating film of the present invention, which exhibits excellent visibility. In another embodiment, the coating film of the present invention can be attached to a window of a display device.

The coating film according to one embodiment of the present invention can be used in a reflective, transmissive or semi-transmissive LCD, or TN type, STN type, OCB type, HAN type, VA type or IPS type LCD. Also, the coating film according to an embodiment of the present invention can be used in various display devices such as a plasma display, a field emission display, an organic EL display, an inorganic EL display, and an electronic paper (E-paper).

The invention is further illustrated by the following examples, comparative examples and experimental examples, which are not intended to limit the scope of the invention.

Examples 1 to 7 and Comparative Examples 1 to 6: Preparation of a photocurable coating composition.

The photocurable coating composition was prepared by mixing the components in the ratios (unit: % by weight) listed in Table 1 below.

Each of the components in Table 1 above is as follows.

Urethane acrylate: urethane hexaacrylate (PU610)

Polyester acrylate (hexafunctional): polyester hexaacrylate (PS610)

Polyester acrylate (tetrafunctional): polyester tetraacrylate (PS420)

Monomer: pentaerythritol triacrylate (M340)

Solvent: methyl ethyl ketone, 2-methoxyethanol

Photoinitiator: 1-hydroxycyclohexyl phenyl ketone

Additive: Modified ruthenium polymer (BYK-3530)

Experimental example 1:

Each of the photocurable coating compositions of Examples 1-7 and Comparative Examples 1-6 was stirred for 1 hour, and applied to a transparent substrate film (80 μm, PMMA) with a Mayer bar (a gravure coater) at a thickness of 6 μm. The film was dried at 70 ° C for 1 minute and cured at 500 mJ / cm ² to produce a coating film.

(1) Storage modulus (G')

When the photocurable coating composition was cured under UV, the storage modulus (G') of the composition was measured using a rheometer (Physica MCR-3xx, Anton Paar).

Specifically, the photocurable coating composition was placed in a furnace at 100 ° C for 2 hours to completely dry the solvent, and the residue was placed as a sample on the bottom plate of the rheometer system, and the rotating member (diameter 8 mm) was measured and The bottom plates are separated by about 100 μm. Then, the spot UV irradiation was fixed at 33.3 MW/cm ² (irradiation distance 57 mm, point UV output 30%), and the storage modulus (G') value was at a frequency of 10 Hz and 0.01 before the curing was about to be completed. Obtained for 20 seconds (20 points / 12 seconds) for 20 points under % strain conditions.

(2) Total transmittance

The total transmittance and total turbidity of the coating film were measured using a spectrophotometer (HZ-1, SGA, Japan) toward the PMMA side of the light source (D65).

(3) Pencil hardness

The pencil hardness of the coating film was measured on a surface of the coating film under a load of 500 g using a pencil hardness tester (PHT, Sukbo Science, Korea). The pencil was obtained from Mitsubishi and the pencil hardness was measured 5 times with each pencil. Two or more scratches were determined as defects, and the hardness of the pencil used before the occurrence of the defect was recorded as the pencil hardness.

Scratch 0: Qualified

Scratch 1: Qualified

Two or more scratches: bad

(4) Scratch resistance

The scratch resistance of the coating film was tested using a steel wool tester (WT-LCM100, Protec, Korea) with 10 reciprocation cycles at 1 kg/(2 cm x 2 cm). Use #0000 as steel wool.

A: The scratch is zero.

A`: scratches are 1 to 10

B: The scratch is 11 to 20

C: scratches are 21 to 30

D: The scratch is 31 or more.

(5) Adhesion

After preparing 100 squares by vertically and horizontally drawing eleven (11) lines at intervals of one (1) mm on the application side of the coating film, the belt (CT-24, Nichiban, Japan) was used for 3 times. Detachment test. The 100 squares were tested three times to determine the average adhesion value.

Adhesion = n/100

n: The number of squares not detached.

100: total number of squares

Therefore, a value of 100/100 indicates that 100 squares have not been detached.

(6) Crack resistance

Using the bending resistance test (mandrel bar) according to JIS-K5600-5-1, the occurrence of cracks was measured according to the mandrel Φ (diameter, mm). The sample size was 2.5 cm x 20 cm (width x length), and it was measured by positioning the composition side of the coating film toward the outside.

The crack resistance of the coating film is measured by a confining mandrel Φ in which no crack occurs.

The results of the above tests are shown in Table 2 below.

As shown in Table 2 above, the coatings produced from the photocurable coating compositions of Examples 1 to 7 The film exhibits excellent crack resistance while maintaining optical and mechanical properties.

In contrast, the coating film produced from the photocurable coating composition of Comparative Examples 1 to 6 had a storage modulus of less than 4.0E+07 Pa or more than 7.0E+07 Pa, and its mechanical strength and crack properties were remarkably deteriorated.

While the invention has been shown and described with respect to the embodiments of the present invention And a variety of changes and modifications are made in the context of the scope.

Therefore, the scope of the invention is intended to be defined by the scope of the appended claims

Claims (17)

A photocurable coating composition having a storage modulus (G') of 4.0E+07 to 7.0E+07 Pa. The photocurable coating composition of claim 1, wherein the photocurable coating composition comprises a photocurable (meth) acrylate oligomer. The photocurable coating composition of claim 2, wherein the photocurable (meth) acrylate oligomer comprises a mixture of a urethane (meth) acrylate and a polyester (meth) acrylate, Or a mixture of two types of polyester (meth) acrylates. The photocurable coating composition according to claim 2, wherein the photocurable coating composition comprises the component in an amount of from 92 to 99 parts by weight based on 100 parts by weight of the solid of the photocurable coating composition. Photocurable (meth) acrylate oligomer. The photocurable coating composition of claim 2, wherein the photocurable (meth) acrylate oligomer comprises a mixture of a tetrafunctional polyester (meth) acrylate and a hexafunctional polyester (meth) acrylate . The photocurable coating composition of claim 5, wherein the photocurable coating composition comprises 20 parts by weight to 50 parts by weight relative to 100 parts by weight of the solids of the photocurable coating composition. The tetrafunctional polyester (meth) acrylate and the hexafunctional polyester (meth) acrylate in an amount of from 45 to 75 parts by weight. The photocurable coating composition of claim 2, wherein the photocurable (meth) acrylate oligomer comprises a tetrafunctional polyester (meth) acrylate and a tetra-hexafunctional urethane (methyl) a mixture of acrylates. The photocurable coating composition of claim 7, wherein the photocurable coating composition comprises 20 parts by weight to 50 parts by weight relative to 100 parts by weight of the solids of the photocurable coating composition. The tetrafunctional polyester (meth) acrylate and the tetra-hexafunctional urethane (meth) acrylate in an amount of from 45 to 85 parts by weight. A photocurable coating composition according to claim 2, which further comprises a photocurable monomer. The photocurable coating composition of claim 9, wherein the photocurable monomer comprises a monomer having a (meth) acrylonitrile group. A photocurable coating composition according to claim 6 wherein some of the hexafunctional polyester (meth) acrylate in the mixture is replaced by a photocurable monomer. A photocurable coating composition according to claim 8 wherein some of the tetra-hexafunctional urethane (meth) acrylate in the mixture is replaced by a photocurable monomer. The photocurable coating composition of claim 2, further comprising a photoinitiator and a solvent. The photocurable coating composition of claim 13, wherein the photocurable coating composition comprises the photoinitiator in an amount of from 0.05 to 10 parts by weight relative to 100 parts by weight of the photocurable coating composition. And the amount is from 0.1 to 85 parts by weight of the solvent. A coating film comprising: a transparent substrate; and a coating formed on one or both sides of the transparent substrate, the coating comprising the curing of the photocurable coating composition according to any one of claims 1 to 14. product. A polarizing plate comprising the coating film of claim 15. A display device comprising the coating film of claim 15.