KR20000059808A - Method for the preparation of the diffused reflection film with high hardness - Google Patents

Abstract

PURPOSE: A method for preparing a diffused reflection film is provided, which film has high hardness and good scratch-resistance and is used to an LCD, a Braun tube, or a plasma display. CONSTITUTION: The method comprises the steps of preparing the UV curing composition consisting of 20-50 parts by weight of polyfunctional acrylate oligomers and monomers, 0.1-10 parts by weight of polyfunctional thiols, 0.1-10 parts by weight of a photopolymerization initiator, a sensitizer, a thermopolymerization inhibiting agent, and 10-70 parts by weight of an organic solvent; preparing the silica dispersion composition which is obtained by mixing the compound by prepared by reacting 5-30 parts by weight of hydrophilic silica particle and 0.2-10 parts by weight of a silane coupling agent, 0.1-5 parts by weight of a dispersing agent and 10-75 parts by weight of a solvent; preparing the coating solution by mixing 100 parts by weigh of the UV curing composition, 10-70 parts by weight of the silica dispersion composition, and 65-95 parts by weight of a diluting agent; coating a substrate film with the coating solution; drying it; and exposing the film to UV light to cure it.

Description

METHOD FOR THE PREPARATION OF THE DIFFUSED REFLECTION FILM WITH HIGH HARDNESS}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a diffuse reflection film having excellent properties of diffuse reflection effect and high hardness, which is used in a liquid crystal display, a cathode ray tube, a plasma display, and the like.

In general, the diffuse reflection film has a function of preventing glare due to reflected light by scattering light incident from the outside. In particular, since the diffuse reflection film used in the liquid crystal display device is placed on the front surface of the liquid crystal display device, it is necessary to have resistance to external stimuli and environmental changes, so it is important to have scratch resistance along with the diffuse reflection property.

Conventional diffuse reflection workpieces include rollers with unevenness, mat-like workpieces (1) that give irregularities on the surface of substrates to produce diffuse reflection effects, and diffused workpieces (2) utilizing differences in compatibility or crystallinity of resins, and inorganic compounds. Workpieces 3, etc. made from a thin layer coating are known. However, in order to manufacture (1) of the above workpieces, the film surface must be flexible, so that scratch resistance of the surface of the substrate is inferior, and (2) changes in compatibility and crystallization characteristics of the resin depending on temperature change and solvent. There are disadvantages that can occur. In addition, the workpiece of (3) is formed by forming a thin monolayer or a multilayer inorganic thin layer on the surface of the substrate in accordance with the wavelength of the light beam, and the substrate that can be used is limited, and the process of thinning the inorganic substance requires additional apparatus and complexity. There is a disadvantage of losing.

An object of the present invention is to provide a method for producing a diffused reflection film that can be mass-produced by a simple method and excellent in diffuse reflection effect and scratch resistance, and a UV curable resin composition, a silica dispersion composition and a diluent are mixed in an appropriate ratio. The method of apply | coating a composition on a base film and drying, irradiating an ultraviolet-ray, and hardening a coating film is used.

The present invention is a silica dispersion composition composed of a UV curable resin composition containing an ultraviolet curable acrylic monomer, a photopolymerization initiator, a solvent, and the like, a hydrophilic silica, a predetermined water, and an acid catalyst to hydrolyze a silane coupling agent, a dispersant, a solvent, and the like. The present invention relates to a method for producing a diffuse reflection film by applying a composition containing a diluent of an organic solvent added in order to adjust the viscosity of the composition to adjust the solid content in an appropriate ratio on a base film.

Hereinafter, the present invention will be described in detail.

The ultraviolet curing composition of the present invention is prepared by containing a polyfunctional acrylate monomer, a polyfunctional thiol compound, a photopolymerization initiator and a sensitizer, a thermal polymerization inhibitor, an organic solvent and the like. Examples of the polyfunctional acrylate monomers include ethylene glycol diacrylate, triethylene glycol acrylate, triethylene glycol diacrylate, 1,3-butanediol diacrylate, 1,4-cyclohexanediacrylate and trimethylol Triacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol tetraacrylate, sorbitol triacrylate, sorbitol tetraacrylate, sorbitol pentaacrylate, sorbitol hexaacrylate, tetramethylene glycoldi Methacrylate, triethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimetha Acrylate, dipentaerythritol, dimethacrylate, sorbitol Trimethacrylate, sorbitol tetramethacrylate, 2-ethylhexacrylate, 2-hydroxyethyl acrylate, acrylic acid, methacrylic acid, itaconic acid, 2-methacryloyloxyethyl succinic acid, 2-acrylic Royloxyethyl succinic acid, 2-methacryloyloxyethylhexahydrophthalic acid, 2-methacrylooxyethylhexahydrophthalic acid, acryloyloxyethyl monophthalate, acryloyloxyethyl monomethyltetrahydrophthalate, 2 -Acryloyloxyethyl hydrogen phthalate, 2-acryloyloxypropyl hydrogen phthalate, 2-acryloyloxypropyl hexahydrogen phthalate, 2-acryloyloxypropyl hydrogen phthalate, methyl methacrylate, ethyl Methacrylate, propyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, stearyl methacrylate, methoxyethyl meth Acrylate, ethoxyethyl methacrylate, butoxyethyl methacrylate, cyclohexyl methacrylate, glycidyl methacrylate, methylamino methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acryl Rate, 2-ethylhexyl acrylate, lauryl acrylate, stearyl acrylate, methoxy ethyl acrylate, ethoxy ethyl acrylate, butoxy ethyl acrylate, cyclohexyl acrylate, glycidyl acrylate, methylamino Acrylate, acrylonitrile, phenyl acrylate, 2 or 4-chlorophenylacrylate, 2 or 4-nitrophenylacrylate, 2 or 4-dimethylaminophenylacrylate, benzylacrylate, 2 or 4-chlorobenzylacrylic Latex, 2 or 4-nitrobenzyl acrylate, 2 or 4-dimethylaminobenzyl acrylate, phenylmethac Rate, 2 or 4-2 chlorophenyl methacrylate, 2 or 4-nitrophenyl methacrylate, 2 or 4-dimethylaminophenyl methacrylate, benzyl methacrylate, 2 or 4-nitrobenzyl methacrylate, 2 or 4-dimethylaminobenzyl methacrylate, 2-hydroxybutyl (meth) acrylate, 2-methacryloyloxyethyl-2-hydroxypropyl phthalate, 2-acrylooxyethyl-2-hydroxypropyl Phthalate, 2-hydroxy-3-acryloyloxypropyl methacrylate, 2-hydroxy-3-phenoxypropyl acrylate, 3-chloro-2-hydroxypropyl methacrylate, 2-hydroxyethyl ( Meta) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxyoctyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2 -Hydroxypropyl (meth) acrylate, 2-hydroxyoctyl (meth Ta) acrylate, glycerin di (meth) acrylate, 2-methacryloyloxyethyl-2-hydroxypropylphthalate, 2-acryloyloxyethyl-2-hydroxypropylphthalate, 2-hydroxy-3 -Acryloyloxypropyl methacrylate, 2-hydroxy-3-phenoxypropyl acrylate, 3-chloro-2-hydroxypropyl methacrylate, cinnamil alcohol, pentaerythritol triacrylate, acrylamido Glycolic acid, 2-cyano-4'-hydroxycinnamic acid, p-hydroxycinnamonitrile, p-hydroxybenzylidene malononitrile, p-hydroxycinnamic acid, 2-hydroxycinnamic acid, 3- Hydroxycinnamic acid, 3-hydroxy-4-methoxycinnamic acid, trans-4-hydroxy-3-methoxycinnamic acid, and the like. In addition to these monomers, prepolymers such as dimers and trimers can be effectively used. .

In the present invention, high sensitivity is realized by using a multifunctional thiol-based compound. That is, a photocurable resin composition using a thiol-based compound is influenced by oxygen during curing even when using a general aromatic ketone or other kinds of radical photoinitiators. UV curable resin composition of very excellent physical properties can be prepared. Such polyfunctional thiol compounds, that is, those containing one or more thiol groups (SH groups), for example, glycol dimercaptoacetate, trimethylolpropane tris (3-mercaptopropionate), trimethylolpropane tris (2-mercaptopropionate), trimethylolpropane tris (2-mercaptoacetate), pentaerythritol tetramis (thioglycolate), pentaerythritol tetrakis (2-mercaptoacetate), allyl mercaptan, Ethylene glycol dimercaptopropionate, trithiocyanuric acid (1,3,5-triazine-2,4,6-tritriol), 3-dithiophenyl ether, 1,3-dimethiomethylbenzene, Pentaerythritol tetrakis mercapto propionate, 1,4-butanedithiol, 1,5-pentanedithiol, 1,6-pentanedithiol, tetramethylene glycol-bis-mercapto propionate, 1,6 -Hexyldiol-bis-mercapto propionate, pentaerythritol bis mercap Propionate, pentaerythritol tris mercapto propionate, trimethylolpropane bismercapto propionate, trimethylolpropane trismercapto propionate, dipentaerythritol trismercapto propionate, sorbitol trismercapto propionate Cypionate, sorbitol tetrakis mercapto propionate, sorbitol hexakis mercapto propionate, dithioethyl terephthalate, 1,5-hexanediol dithioethyl ether, 1,5-pentanediol dithioethyl ether, penta Erythritol-tetra- (beta-thioethylether) and the like. As the cross-linking mechanism of the thiol-based compound, the polyfunctional polythiol and the polyene compound in the exposed portion react to form a linear and three-dimensional network structure. Mars can be realized.

As the photopolymerization initiator and the sensitizer, one or more compounds such as benzophenone, acetophenone and thioxanthone can be mixed and used. Specific examples thereof include benzyl, benzoin, benzoylmethyl ether, benzoin ethyl ether and benzoin. Isopropyl ether, benzoin isobutyl ether, 4,4-dimethoxybenzyl (p-anisyl), 1,4-dibenzoylbenzene, 4-benzoylbiphenyl, 2-benzoylnaphthalene, 1-hydroxycyclohexylphenyl Ketone, benzyldimethyl ketal, benzyldiethyl ketal, benzyldimethoxyethyl ketal, 2,2'-diethoxyacetophenone, 2,2'-dibutoxyacetophenone, 2-hydroxy-2-methylproriophenone, pt Butyl trichloroacetophenone, pt-butyldichloroacetophenone, benzophenone, 4-chloroacetophenone, α, α-dimethoxy-α-hydroxy acetophenone, 1- (4-isopropylphenyl) -2-hydride Oxy-2-methyl-propan-1-one, 1- [4- (2-hydroxyethoxy) phenyl] -2-methyl-propan-1-one, oli [2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] -propanone, methyldiethanolamine, triethanolamine, 4,4'-dichlorobenzophenone, methyl o-benzoylbenzoate, 3,3'-dimethyl-2-methoxybenzophenone, 4-benzoyl-4 'methylphenyl, thioxanthone, 2-chlorothioxanthone, 2-methyl thioxanthone, 2-isobutyl thioxanthone, 2- Dodecyl thioxanthone, 2,4-dimethyl thioxanthone, 2,4-diethyl thioxanthone, 2-ethylanthraquinone, 2-propylanthraquinone, 2,2-dichloro-4-phenoxyacetophenone, 2 -Methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-monolinophenyl) -butan-1-one, p-dimethylaminobenzoic acid isoamyl ester, p-dimethylaminobenzoic acid, p-dimethylaminobenzoic acid methyl ester, p-dimethylaminobenzoic acid ethyl ester, p-dimethylaminobenzoic acid butyl ester, p-dimethylaminobenzoic acid isopentyl ester, o -dimethyl Minobenzoic acid ethyl ester, p-dimethylaminoacetophenone, 4,4-dimethylaminobenzophenone, 4,4'-diethylaminobenzophenone, 9-fluorolenone, 2-chloro-9-fluorenone, 2-methyl -9-fluorenone, 9-anthrone, 2-bromo-9-anthrone, 9,10-anthraquinone, 2-ethyl-9,10-anthraquinone, 2-t-butyl-9,10-anthra Quinone, 2,6-dichloro-9,10-anthraquinone, xanthone, 2-methyl-xanthone, 2-methoxyxanthone, dibenzaxlactone, p- (dimethylamino) phenylstyrylketone, p- ( Dimethylamino) phenyl-p-methylstyrylketone, p- (dimethylamino) benzophenone (or micelle ketone), p- (diethylamino) benzophenone, benzanthrone, benzothiazole compound, 10-butyl-2 -Chloroacridone, 2,2'-bis (o-chlorophenyl) -4,5,4 ', 5'-tetraphenyl-1,2'-biimidazole, and the like; By adding a small amount of phosphate-based compounds, the photopolymerization rate can be effectively increased. Specific examples thereof include tri-o-tolylphosphine, tri-m-tolylphosphine, tri-p-tolylphosphine, and tritolylphosphate. In particular, the compounds have a great influence on the improvement of the mechanical properties of the cured resin, that is, the glass transition temperature of the cured resin is significantly increased, as well as the ability to almost completely eliminate the photopolymerization inhibitory effect of oxygen. On the other hand, it is also possible to use an acid generating photoinitiator, for example, onium salts, triazine derivatives. In addition, hydroquinone, hydroquinone monomethyl ether, etc. may be added as a polymerization inhibitor for the storage stability, or benzimidazole, 2-mercapto benzimidazole, benzthiazole, and 2-mercapto benzthiazole as an adhesion improving agent. , Benzoxazole, 2-mercapto benzoxazole, benztriazole and the like may be added in small amounts. The effect of using the above-described adhesive improver has the advantage of improving the adhesion to the substrate after the coating, drying, exposure process.

As the silane coupling agent used in the silica dispersion composition in the present invention, vinyltrimethoxysilane, vinyl-tris- (2-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, and the like are used. Hydrochloric acid and a small amount of water are added to the compound of hydrochloric acid, nitric acid, and the like in an equivalent ratio and reacted for several hours in a range of 100 ° C. at room temperature. In order to prevent gelation of the compound produced by this reaction, an appropriate amount of ion exchange resin is added to remove residual acid, thereby securing storage stability. The amine value is 10 to 60 (mgKOH / g) and the acid value is 8 to 80 (mgKOH / A polyacrylic or polyurethane-based dispersant having g) is added in the range of 1 part by weight to 20 parts by weight based on 100 parts by weight of silica.

In this invention, unevenness | corrugation is formed in a hardened film using a silica particle, and a diffuse reflection effect is provided by this unevenness. The silica particles used in the silica dispersion composition are composed of silicon dioxide, have amorphous, porous properties, and have a spherical shape with a refractive index of about 1.46. And it is suitable that the size of a silica particle is 50 nm-10 micrometers. If the particle size is less than 1 μm, the surface area is larger than the volume of the particle, and thus the surface energy increases, so that aggregation occurs easily. When the size of the silica particle is larger than 10 μm, the coating property is poor, the surface state of the coating film is rough, and the sharpness is high. There is a problem that becomes poor. As a method used to improve the dispersibility of silica particles, there are milling methods such as a ball mill and a sand mill. The solvent used for a silica dispersion composition can be used individually or in mixture with isopropyl alcohol, methyl ethyl ketone, toluene, ethyl acetate, butyl acetate, etc.

The diluent used in the present invention is an organic solvent added to adjust the viscosity and solids content of the coating liquid, and toluene, ethyl acetate, methyl ethyl ketone, or the like is used alone or in combination.

The manufacturing method of the high hardness diffuse reflection film provided by this invention is demonstrated more concretely. First, an ultraviolet curable resin composition is manufactured so that it may become a ratio of 20-50 weight part of ultraviolet curable polyfunctional acrylic monomers, 0.1-10 weight part of polyfunctional thiol type compounds, 0.1-10 weight part of photoinitiators, and 10-70 weight part of solvents. The silica dispersion composition was 0.2-10 parts by weight of the silane coupling agent, 5-30 parts by weight of the hydrophilic silica particles, 1-10 parts by weight of ultrapure water adjusted to pH 4 or less with hydrochloric acid or nitric acid, and reacted at 60 ° C. for several hours. It is prepared by adding the resin so that the dispersant is 0.1 to 5 parts by weight and the solvent is 10 to 75 parts by weight. Subsequently, the mixing ratio of the silica dispersion composition to the ultraviolet curable resin composition is determined according to the degree of diffuse reflection effect of the desired transparent film, and the amount of the diluent is determined so as to have a viscosity and solid content of the desired composition, and the composition is mixed with the base film. The coating method is gravure coater, reverse coater, spray coater, slot coater, etc., which are common solution coating methods, and is usually applied so that the thickness of the film after drying is 1 to 10 μm, and ultraviolet rays after heat drying are applied. Irradiation hardens the film. As the base film, any film having good transparency and UV resistance such as polyester film, polycarbonate film, polyacryl film, and polyamide film can be used, and triacetate in which a polarizing plate, which is a part of a liquid crystal display device, is used as a protective film. Cellulose (TAC) films are also possible.

The following Examples and Comparative Examples are intended to illustrate the present invention in more detail, wherein the physical property evaluation of the film used the following method. That is, Haze indicating the transmittance of the film and the degree of diffuse reflection effect was measured by Haze-Meta (NH20D model manufactured by Nippon Color Industries, Ltd.), and the clearness of the film was also measured by the same device. Glossiness was measured at a gloss measuring device (manufactured by Yasuda Seiki, Japan; No. 556) at a 60 ° / 60 ° angle, and the surface hardness of the cured film was measured with a pencil hardness meter (JIS K 5410). Evaluation of the adhesion (adhesiveness) was measured by the cellophane adhesive tape according to JIS K 5400.

<Example>

(1) Preparation of UV-curable resin composition: polyfunctional acrylic monomer (40 parts by weight of dipentaerythritol hexaacrylate, 8 parts by weight of pentaerythritol-triacrylate), polyfunctional thiol-based compound {pentaerythritol tetrakis ( 3-mercaptopropionate)} 5 weight part, 3 weight part of photoinitiators (1-hydroxycyclohexylphenyl ketone), and 44 weight part of toluene as a solvent are mixed uniformly, and an ultraviolet curable resin composition is manufactured.

(2) Preparation of Silica Dispersion Composition: 5 parts by weight of methacryloxypropyltrimethoxysilane, 20 parts by weight of silica particles (manufactured by Fuji Silysia; Silysia 310), and a dispersant (manufactured by Efka Chemicals; Yeff Keai-451 ) 4 parts by weight, 2 parts by weight of water (ultra pure water, pH 2) and 69 parts by weight of toluene were uniformly mixed and reacted at 60 ° C. for 3 hours, followed by addition of an ion exchange resin and stirring for 2 hours, followed by filtering to prepare a silica dispersion composition. do.

(3) Preparation of coating liquid: Toluene was uniformly mixed in the ratio shown in Table 1 with the silica dispersion composition prepared in (2) and the diluent based on 100 parts by weight of the ultraviolet curable resin composition prepared in (1), which was 50 µm. It was passed through a filter to prepare a coating solution. The viscosity of the coating solution thus prepared was 5-10 cps (25 ° C) with a Brookfield viscometer.

The coating solution prepared in (3) above was coated on a triacetate cellulose film at a line speed of 10 to 30mpm using a gravure coater, dried at 80 to 90 ° C., and then to an ultraviolet lamp (high pressure mercury lamp; 80 to 160 W / cm). Ultraviolet rays were irradiated to prepare a transparent film having a cured coating film. The physical properties of the film were evaluated and shown in Table 1.

<Comparative Example>

The physical properties of the film prepared under the same conditions as in Example 1 were evaluated except that methacryloxypropyltrimethoxysilane was not added in the preparation of the silica dispersion composition and the composition ratio was shown in Table 1. It is shown in Table 1.

division Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Furtherance UV curable resin composition 100 100 100 100 100 100 Silica dispersion composition 10 30 50 70 10 30 Diluent 65 75 85 95 65 75 Properties Transmittance (%) 92 91 90 89 92 91 Haze (%) 10 27 37 45 10 26 Glossiness 55 30 23 20 55 30 Surface hardness 3H 4H 4H 5H 2H 2H Sharpness 59 55 50 43 60 55 Adhesion Good Good Very good Very good usually usually

As can be seen from the above examples and comparative examples, the diffuse reflection film obtained according to the present invention has excellent surface hardness and the like, and exhibits high hardness properties, and separately prepares and mixes an ultraviolet curable resin composition and a silica dispersion composition separately. It is possible to obtain the diffuse reflection property of the desired film, and because acrylic resin is used as the cured film, it shows excellent properties in terms of chemical resistance and durability, so that it can be applied to various fields where diffuse reflection effect and high hardness are required such as liquid crystal display device. It can be useful.

Claims (3)

Hydrophilic silica particles and silane coupling agent were added to 100 parts by weight of the UV curable composition prepared by adding a polyfunctional acrylate oligomer and monomer, a polyfunctional thiol compound, a photopolymerization initiator and a sensitizer, a thermal polymerization inhibitor, and an organic solvent. A coating solution comprising 10 to 70 parts by weight of a silica dispersion composition containing a dispersant and a solvent and 65 to 95 parts by weight of a diluent is applied onto the base film and irradiated with ultraviolet rays after drying to harden the coating film. The manufacturing method of a diffusely reflective film of conductiveness. According to claim 1, wherein the ultraviolet curable composition is 20 to 50 parts by weight of the ultraviolet curable acrylic monomer, 0.1 to 10 parts by weight of a thiol-based compound, 0.1 to 10 parts by weight of the photoinitiator, characterized in that the mixture of 10 to 70 parts by weight of the solvent Method of producing a high hardness diffuse reflection film. The dispersion composition of claim 1, wherein the silica dispersion composition comprises 0.1 to 10 parts by weight of hydrophilic silica particles and 0.2 to 10 parts by weight of the silane coupling agent together with 1 to 10 parts by weight of ultrapure water, which is formed at pH 4 or less under an acid catalyst. 5 parts by weight and a solvent containing 10 to 75 parts by weight of a method for producing a high hardness diffuse reflection film, characterized in that the composition.