TWI643910B - Organic-inorganic hybrid hard coating film and polarizing plate using the same - Google Patents

Abstract

The invention provides an organic-inorganic hybrid hard coating film, comprising: a hard coating layer formed by coating a composition for forming a hard coating layer on a surface of a transparent base film, the composition including a The acrylic resin has an average number of functional groups of 5 to 15, an inorganic particle, an ultraviolet reactive group, and a photoinitiator. The acrylic resin contains 10% by weight or more of a trifunctional or lower acrylic resin, and the inorganic particles are contained in an amount of 80 to 120 parts by weight based on 100 parts by weight of the acrylic resin.

Description

Organic-inorganic hybrid hard coating film and polarizing plate using the same material

The invention relates to an organic-inorganic hybrid hard coating film and a polarizing plate using the same material.

A hard coating layer is widely used to protect the surface of various flat display panels, such as thin film transistor-liquid crystal displays, plasma display panels, organic light emitting diodes, cathode ray tubes, and the like.

The glass substrate used in the display panel is weak in impact resistance and difficult to reduce weight. In order to replace these display panels or make up for their shortcomings, a thin film with a high hardness hard coating layer formed on the surface of a plastic transparent substrate has been widely used.

Meanwhile, there is a known composition for forming an organic-inorganic hybrid hard coating layer, which contains an inorganic particle and an organic resin to improve the hardness and abrasion resistance of the hard coating layer.

In particular, Korean Patent Publication No. 2009-0044089 discloses a composition for forming an organic-inorganic mixed hard coating layer, including a urethane acrylate oligomer having a molecular weight of 500 to 10,000, and a multifunctional Acrylate monomer and silicon dioxide.

However, since the pencil hardness of the hard coating layer is only 2H ~ 3H, it does not have sufficient protection performance, and sufficient protection performance is necessary for a good hard coating layer. So one has The organic-inorganic hybrid hard coating film has excellent optical characteristics, and excellent surface hardness and abrasion resistance, and has seen its needs.

Therefore, the present invention has been used to solve the above-mentioned problems occurring in the conventional technology, and an object of the present invention is to provide an organic-inorganic hybrid hard coating film having high surface hardness and excellent scratch resistance and abrasion resistance. Destructive.

In order to achieve this purpose, an organic-inorganic hybrid hard coating film is provided, which comprises: a hard coating layer formed by coating a composition for forming a hard coating layer on a surface of a transparent base film, The composition includes an acrylic resin, an average number of functional groups of 5 to 15, an inorganic particle, an ultraviolet reactive group, and a photoinitiator. The acrylic resin contains 10% by weight or more of a trifunctional or lower acrylic resin, and the inorganic particles are contained in an amount of 80 to 120 parts by weight based on 100 parts by weight of the acrylic resin.

The average number of functional groups of the acrylic resin may be 6 to 14.

The inorganic particles may have an average particle diameter of 1 to 100 nm.

The hard coating layer may have a thickness of 17 to 30 μm.

The hard coating layer may have a surface hardness of 7H or higher.

According to an aspect of the present invention, there is provided a polarizing plate including an organic-inorganic hybrid hard coating film according to any one of claims 1 to 5 of a patent application.

An organic-inorganic hybrid hard coating film of the present invention includes a hard coating layer formed by coating a composition for forming a hard coating layer on a surface of a transparent base film. The composition includes an acrylic The resin has an average number of functional groups of 5 to 15, an inorganic particle, an ultraviolet-reactive group, and a photoinitiator. The acrylic resin contains 10% by weight or more of a trifunctional or lower acrylic resin. The inorganic particles are contained in an amount of 80 to 120 parts by weight based on 100 parts by weight of the acrylic resin.

Hereinafter, the present invention will be described in further detail, but the description is only used to illustrate the present invention and is not intended to limit the scope of the present invention.

The composition for forming a hard coating layer includes an acrylic resin having an average number of functional groups of 5 to 15, an inorganic particle, an ultraviolet-reactive group, and a photoinitiator.

The acrylic resin having an average number of functional groups of 5 to 15 is a photocurable resin, and may include a photocurable (meth) acrylate oligomer and a monomer.

The photocurable (meth) acrylate oligomer, epoxy (meth) acrylate, urethane (meth) acrylate, or the like may be conventionally used, preferably urethane (formaldehyde) Based) acrylate. The urethane (meth) acrylate can be prepared by using a polyfunctional (meth) acrylate having a hydroxyl group in its molecule and a compound having a monoisocyanate group in the presence of a catalyst. Specific examples of (meth) acrylic acid having a hydroxyl group in its molecule may be one or more selected from the group consisting of 2-hydroxyethyl (meth) acrylate, 2-hydroxyisopropyl (meth) acrylic acid, 4- Hydroxybutyl (meth) acrylate, caprolactone ring-opening hydroxyacrylic acid, pentaerythritol tri / tetra (meth) acrylate mixture, and a double pentaerythritol pentaerythritol pentaerythritol pentaerythritol pentaerythritol pentaerythritol pentaerythritol pentaerythritol pentaerythritol pentaerythritol pentaerythritol pentaerythritol pentaerythritol pentaerythritol tri / tetrakis (meth) acrylate mixture Group) consisting of acrylate) mixtures. In addition, specific examples of the compound having a monoisocyanate group may be one or more selected from the group consisting of 1,4-diisocyanatobutane, 1,6-diisocyanate, 1,8-diisocyanatooctane, 1,12-diisocyanatodecane, 1,5-isocyanato-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, xylyl-1,4-diisocyanate, tetramethyl-1,3-diisocyanate, 1-chloromethyl-1,4-diisocyanate, 4 , 4'-methylenebis (2,6-dimethylphenyl isocyanate), 4,4'-oxybis (phenyl isocyanate), trifunctional diisocyanate from hexamethylene diisocyanate A group of acids and trimethylolpropane adducts of toluene diisocyanate.

The photocurable monomer has an unsaturated group, for example, a (meth) acrylfluorenyl group, a vinyl group, a styryl group, an allyl group or the like, and is used as a photocurable in its molecule. The functional group is preferably a (meth) acrylfluorenyl group.

Specific examples of the monomer having a (meth) acrylfluorenyl group may be one or more selected from the group consisting of neopentyl glycol diacrylate, 1,6-hexanediol (meth) acrylate, and propylene glycol di (methyl). Acrylate, triethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylic acid, trimethylol Propane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, 1,2,4-cyclohexane tetra (meth) acrylate, pentaglycerol tri (meth) acrylate, Pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol Hexa (meth) acrylate, tripentaerythritol tri (meth) acrylate, three quarter Pentaerythritol hexatris (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 (methyl ) A group of acrylates, phenoxyethyl (meth) acrylates, and isobornyl (meth) acrylates.

Among the acrylic resins exemplified, the photocurable (meth) acrylate oligomer and the photocurable monomer may be used alone or in a combination of two or more.

The average number of functional groups of the acrylic resin of the present invention is 5 to 15. If the average number of functional groups is less than 5, the curing density may be low and fail to show sufficient hardness. If the average number of functional groups is more than 15, reactivity may be reduced, resulting in defects in curing characteristics, or curing shrinkage may become severe, although there are sufficient curing steps, resulting in cracking of the film.

In addition, the acrylic resin of the present invention includes 10% or more of a trifunctional or lower acrylic resin. If the trifunctional or lower acrylic resin is contained in an amount of less than 10% based on the total acrylic resin, the curing reactivity may be reduced, and sufficient hardness may not be exhibited.

Examples of trifunctional or lower acrylic resins may include caprolactone acrylate, octyl acrylate, isooctyl acrylate, lauryl acrylate, ethoxyethoxyethyl acrylate, stearyl acrylate, hexanediol di Acrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, trimethylolpropane triacrylate, and pentaerythritol triacrylate Acrylate.

The inorganic particles having an ultraviolet-reactive group may be metal oxides, sulfides, or the like. Specific examples may include titanium dioxide (rutile, rutile / anatase mixed Crystal, or anatase type amorphous structure), silicon oxide, indium oxide, tin oxide, zirconia, zinc oxide, and zinc sulfide. Inorganic oxide colloids can also be used. Examples thereof may include colloidal titanium dioxide, colloidal alumina, colloidal zirconia, colloidal vanadium oxide, colloidal chromium oxide, colloidal iron oxide, colloidal tin oxide, or a mixture thereof. Silicon dioxide is preferred.

Inorganic particles have an optimal average particle diameter of 1 to 10 nm. If the average particle diameter of the particles is less than 1 nm, the hardness may be lower. If the average particle diameter of the particles is more than 100 nm, transparency may be reduced.

The inorganic particles are contained in an amount of 80 to 120 parts by weight based on 100 parts by weight of the acrylic resin. If the content of the inorganic particles is less than 80 parts by weight, the hardness may be reduced. If the content of the inorganic particles exceeds 120% by weight, the reaction rate may decrease and the transparency may decrease.

As the photoinitiator, any of the photoinitiators used in the previous examples can be used. Particularly at least one selected from the group consisting of 2-methyl-1-4- (methylthio) phenyl] -2-morpholinylpropane-1, benzophenone benzyldimethylketal, 2-hydroxy-2 -Methyl-1-phenylpropane-1-one, 4-hydroxycyclohexylphenyl ketone, dimethoxy-2-phenylacetophenone, anthraquinone, triphenylamine, carbazole, pyrene, 3-methyl Acetophenone, 4-chloroacetophenone, 4,4-dimethoxyacetophenone, 4,4-diaminobenzophenone, 1-hydroxycyclohexylphenyl ketone and benzophenone Groups can be used.

The photoinitiator may be used in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the entire composition used to form a hard coating layer. If the content of the photoinitiator is less than 0.1 part by weight, the curing rate may be slowed. If the content of the photoinitiator is more than 10 parts by weight, cracks may occur in an anti-glare hard coating layer due to excessive curing.

The composition for forming a hard coating layer may include a solvent. As the solvent, Any of the solvents known for forming a coating layer used in the foregoing examples can be used without limitation.

In particular, at least one selected from the group consisting of alcohols (methanol, ethanol, isopropanol, butanol, methyl cellosolve, ethyl cellosolve, etc.), ketones (methyl ethyl ketone, methyl butyl ketone, methyl alcohol) Isobutyl ketone, diethyl ketone, dipropyl ketone, cyclohexanone, etc.), hexanes (hexane, heptane, octane, etc.) and benzenes (benzene, toluene, xylene, etc.) Groups can be used.

The solvent may be contained in an amount of 10 to 95 parts by weight based on 100 parts by weight of the entire composition for forming a hard coating layer. If the weight content of the solvent is less than 10 parts by weight based on 100 parts by weight of the composition for forming an anti-glare hard coating layer, the viscosity may be high and thus processability may be deteriorated. If it exceeds 95 parts by weight, the drying process is very time-consuming and thus economic feasibility may be reduced.

The present invention provides a hard coating layer including a hard coating layer formed by using the above composition for forming a hard coating layer. That is, an anti-glare film of the present invention includes a hard coating layer formed by coating a composition for forming a hard coating layer on at least one surface of a transparent base and then curing.

As a transparent base, any film having transparency can be used without limitation. An example of a transparent base may be a cycloolefin derivative selected from a cyclic olefin derivative, including a cyclic olefin, such as a norbornene ring or a polycyclic norbornene-based monomer, cellulose (diethyl cellulose, triethyl cellulose Ethyl cellulose, ethyl cellulose, isobutyl cellulose, propyl cellulose, butyl cellulose, and ethyl acetate cellulose), ethylene-vinyl acetate copolymer, polyester, polystyrene, polyfluorene Amines, polyetherimide, polyacrylic acid, polyimide, polyetherimide, polyfluorene, polyethylene, polypropylene, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyimide Vinyl acetal, polyether ketone, polyether Ether ketone, polyether fluorene, polymethyl methacrylate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyurethane and ring Oxygen resin. Unstretched or uniaxially or biaxially stretched films can also be used. The best case is to use a uniaxially or biaxially stretched polyester fiber film having excellent transparency and heat resistance, or a triethyl cellulose film having neither transparency nor optical anisotropy.

The thickness of the transparent base may be about 8 to 1000 μm, preferably 40 to 100 μm.

The method of coating the composition for forming an anti-glare layer on the transparent base is not particularly limited, but die coating, air knife, reverse roll, spray coating, blade, casting, gravure, spin-coating, or the like The method can be adopted.

Regarding the hard coating layer formed by coating the composition for forming an anti-glare layer on the transparent base, the thickness of the hard coating layer after curing is preferably 17 to 30 μm.

The method for curing the composition for forming a hard coating layer may be performed by photo-curing. Here, the irradiation amount of ultraviolet light may be about 0.01 to 10 J / cm2, and preferably 0.1 to 2 J / cm2.

The hard coating layer prepared by the aforementioned treatment may have a hardness of 7H or higher. An organic-inorganic hybrid hard coating film including the hard coating layer may be included in a polarizing plate or a display device.

The present invention provides a polarizing plate having an organic-inorganic hybrid hard coating film according to the present invention. That is, the polarizing plate of the present invention can be manufactured by laminating the aforementioned anti-glare film according to the present invention to one or both surfaces of a conventional polarizer. The polarizer may be provided with a protective film on at least one surface thereof.

Hereinafter, the present invention will be described in more detail through the following examples and comparative examples. Described. The following examples are merely illustrative and illustrative, and should not be construed as limiting or limiting the scope of the invention.

Examples and Comparative Examples

(1) Preparation of a composition for forming a hard coating layer

Each composition for forming a hard coating layer having a branched structure and its content (parts by weight), as shown in Table 1, was screened by using a PP-material filter, and then coated at 80 μm. -The upper surface of the triethylammonium cellulose film (base film) is thick so that its thickness becomes 20 μm after curing.

In each composition used to form a hard coating layer, it was prepared in Preparation Examples 1 to 6 and Comparative Preparation Examples 1 to 5, with an average number of functional groups equal to the trifunctional or lower resin content of the acrylic resin. The calculation and table of the content of inorganic particles based on the weight of 100 parts of acrylic resin are shown in Table 2 below.

(2) Preparation of hard coating film with hard coating layer

A hard coating layer is formed by coating a composition for forming a hard coating layer on an 80 μm-thick cellulose triacetate film, drying the solvent for 2 minutes, and applying ultraviolet curing to a mosaic light of 500 mJ / cm2. For each example, the composition used to form a hard coating layer and the thickness of the hard coating layer after hardening are shown in Table 3.

[table 3]

Experimental example

The physical properties of the organic-inorganic hybrid hard coating film having a hard coating layer were measured by the methods described below in Preparation Examples and Comparative Preparation Examples, and the results are shown in Table 4. The measurement and evaluation scenarios are as follows.

(1) Evaluation of pencil hardness

The measurement was performed by using a pencil hardness tester (SukBo Scientific Corporation) based on JIS K5600. Under a load of 500g, the pencil is fixed at a 45-degree angle, and then the surface is scratched according to the hardness of the pencil, and whether the surface is scratched is determined with the naked eye.

(2) Evaluation of scratch resistance

The steel wool was installed on a friction tester (KPD-301, Kipae). Under a load of 1 kg, the steel wool was moved 10 times, and the number of scratches was calculated.

(3) Fog measurement

Haze was measured using an HZ-1 haze meter manufactured by Sga.

(4) Transmittance-sharpness measurement

The measurement was performed by using a light transmittance-definition meter (ICM-1T, Suga Corporation). The transmittance definition is measured by increasing the transmittance definition values for the slit intervals of 0.01 mm, 0.5 mm, 1.0 mm, and 2.0 mm.

As shown in Table 4 above, the organic-inorganic materials according to Examples 1 to 10 of the present invention can be confirmed. The mixed hard coating film has excellent transparency, low haze and excellent hardness and scratch resistance.

The organic-inorganic hybrid hard coating film according to the present invention can have low haze, high reflection sharpness and excellent optical characteristics, high surface hardness, excellent abrasion resistance, and excellent abrasion resistance.

Claims (5)

An organic-inorganic hybrid hard coating film includes: a hard coating layer formed by coating a composition for forming a hard coating layer on a surface of a transparent base film, the composition including an acrylic resin An average number of functional groups of 5 to 15, an inorganic particle, an ultraviolet reactive group, and a photoinitiator, wherein the acrylic resin contains 10% by weight or more of trifunctional or lower Acrylic resin, wherein the inorganic particles having the ultraviolet-reactive group are nano silica sol, and the inorganic particles having the ultraviolet-reactive group are contained in 80 to 120 parts by weight based on 100 parts by weight of the acrylic resin Content, and the hard coating layer therein has a surface hardness of 7H or higher. The organic-inorganic hybrid hard coating film according to item 1 of the scope of the patent application, wherein the average number of functional groups of the acrylic resin is 6 to 14. The organic-inorganic hybrid hard coating film according to item 1 of the scope of patent application, wherein the inorganic particles have an average particle diameter of 1 to 100 nm. The organic-inorganic hybrid hard coating film according to item 1 of the patent application scope, wherein the hard coating layer has a thickness of 17 to 30 μm. A polarizing plate includes the organic-inorganic hybrid hard coating film according to any one of claims 1 to 4 in the scope of patent application.