JP4373996B2 - Conductive anti-glare film forming composition, conductive anti-glare film and display - Google Patents

Description

  The present invention relates to a composition for forming a conductive anti-glare film, a conductive anti-glare film, and a display having a conductive anti-glare film on a display surface, and more particularly, the surface of various transparent substrates, particularly LCDs and plasma displays By applying or printing on the display surface, and drying, it has a high anti-glare effect and an excellent antistatic effect, and there is no hue absorption, so the visible light transmittance of the film is very high and the hue of the transmitted image is natural. The present invention relates to a composition capable of forming a conductive antiglare film, a conductive antiglare film, and a display having such a conductive antiglare film on a display surface.

  A cathode ray tube used as a TV cathode ray tube or a computer display projects characters and images on a display screen by colliding an electron beam against a fluorescent screen emitting red, green, and blue light. Visibility is reduced due to dust adhering to static electricity. Recently, the generation of static electricity has been pointed out in plasma displays that are being applied as wall-mounted televisions. As a countermeasure, there is a demand for a function of imparting electrical conductivity to the optical film attached to the FPD display surface and preventing the adhesion of dust. In addition, there is a problem that an image is difficult to see due to reflection of external light such as a fluorescent lamp, and as a countermeasure, it has been required to provide an antiglare function while maintaining high transmittance.

  In order to solve these problems, conventionally, a coating liquid in which fine particles such as silver and gold are uniformly dispersed in the liquid is applied on the display surface of the display device and dried, or by sputtering or vapor deposition. A conductive transparent metal thin film is formed, and a transparent layer having a different refractive index is laminated on the upper layer and / or the lower layer of the transparent metal thin film in order to prevent charging and reflection. For example, as a transparent conductive film excellent in electromagnetic wave shielding effect and antireflection effect, a transparent conductive fine particle layer composed of metal fine particles having an average particle diameter of 2 to 200 nm and a transparent film having a refractive index different from this are proposed. (For example, refer to Patent Document 1). Furthermore, what laminated | stacked the film | membrane which added organic or inorganic particle | grains, such as a silica, an acryl, a urethane bead, and gave the glare-proof property is proposed (for example, refer patent document 2).

  In addition, an oxide semiconductor transparent film generally exhibits high light transmittance with respect to visible light, and has low resistance and strong film strength. Therefore, a transparent electrode such as a liquid crystal display, a window material for a solar cell, a heat ray reflective film, It is used in various fields such as antistatic film. As such an oxide semiconductor, tin oxide, tin oxide containing antimony (hereinafter referred to as ATO), indium oxide containing tin (hereinafter referred to as ITO), and the like are known (for example, patents). References 3-8).

  Conventionally, a metal or semiconducting metal oxide is deposited on an insulator by a vapor phase method such as vacuum deposition, sputtering, or ion plating, or a dispersion in which a binder component (binder) is dispersed in a resin solution. There is known a coating method or the like for applying or printing as a paint or ink.

JP-A-8-77832 Japanese Patent Laid-Open No. 11-115087 Japanese Patent Laid-Open No. 5-289313 JP-A-6-295666 Japanese Patent Laid-Open No. 7-242844 JP-A-8-143792 JP-A-8-199096 JP-A-11-181335

  However, in the conductive film obtained when silver is used as the metal fine particles, absorption occurs in transmitted light of 400 to 500 nm depending on the light transmission spectrum of silver, the conductive film is colored yellow, and the hue of the transmission image is There was a problem that it changed unnaturally, and since the average visible light transmittance of the film was low, unevenness in the transmitted color due to the film thickness distribution was easily noticeable, and there was a problem that productivity deteriorated to prevent it.

Further, the transparent conductive film obtained from the conductive film-forming composition using indium oxide containing tin also has the problem that the color of the transmitted image changes unnaturally in the same manner as yellow or blue. An oxide semiconductor transparent film of ATO or ITO is bluish due to steep absorption in the infrared region, particularly the near infrared region. Further, even in an oxide semiconductor transparent film that does not absorb in the infrared region such as tin oxide, the light transmittance near 400 nm is low and yellowish. Therefore, the conventional oxide semiconductor transparent film has a problem that the spectral curve in the visible light region is not flat, and the hue of transmitted light changes unnaturally (wavelength and light transmittance in the case of ITO in FIG. 1). And the graph showing the correlation between the wavelength and the light transmittance in the case of SnO ₂ ). Therefore, even when a transparent substrate is used, it has been difficult to obtain a transparent conductive film having high transparency and having film properties such as conductivity reaching a level necessary for practical purposes. In addition, until now there have been those that have been provided with an anti-glare effect by combining an oxide semiconductor such as ATO or ITO and translucent fine particles, but there is a conductive anti-glare film that has color and high transparency. It was difficult to get.

  The present invention has been made to solve the above-described problems, and has an excellent antistatic effect and no hue absorption, so that the visible light transmittance of the film is very high and the hue of the transmitted image is natural. Furthermore, it is possible to provide a composition capable of forming a conductive antiglare film having a high antiglare effect, such a conductive antiglare film, and a display having such a conductive antiglare film on a display surface. It is an object.

As a result of diligent investigations to achieve the above object, the present inventors have dispersed tin hydroxide [Sn (OH) ₄ ] powder and translucent fine particles in a specific quantitative ratio in the binder component. We have found that desirable results can be obtained and have reached the present invention.

  That is, the conductive anti-glare film forming composition of the present invention comprises a binder component, tin hydroxide powder and translucent fine particles dispersed in the binder component, and the total of the tin hydroxide powder and the binder component. When the mass is X and the mass of the translucent fine particles is Y, the mass ratio of X / Y is in the range of 99.9 / 0.1 to 50/50.

  The conductive antiglare film of the present invention is obtained by applying or printing the above composition for forming a conductive antiglare film and drying it.

  Furthermore, the display of the present invention is characterized by having the above-described conductive antiglare film on the display surface.

The composition for forming a conductive antiglare film of the present invention can form a conductive antiglare film on a substrate by applying or printing it on a substrate as a paint or ink and drying it. Therefore, the present invention can be applied to a resin substrate having a relatively low heat resistance and substrates having various shapes, and the conductive anti-glare film can be continuously mass-produced, and the area can be easily increased. About the conductive anti-glare film obtained, for example, the surface resistance value is preferably 10 ⁷ to 10 ¹² Ω / □, more preferably 10 ⁷ to 10 ¹¹ Ω / □, by adjusting the film forming conditions. A conductive anti-glare film excellent in all of transparency, conductivity, and anti-glare properties, with a rate of preferably 85% or more, a haze of preferably 3 to 50%, and more preferably 8 to 40%. Therefore, the composition for forming a conductive antiglare film of the present invention is used in a wide range of fields such as transparent electrodes such as liquid crystals, solar cell window materials, infrared reflective films, antistatic films, touch panels, surface heating elements, and electrophotographic recording. It can be used in various fields and can exhibit excellent performance in each field.

  In the composition for forming an electroconductive antiglare film of the present invention, a tin hydroxide powder and translucent fine particles are dispersed in a binder component, and as the tin hydroxide powder, a powder of tin hydroxide itself or Tin hydroxide powder containing at least one of P, Al, In, Zn and Sb can be used as the dopant.

As shown in FIG. 1, the tin hydroxide powder that can be used in the present invention has excellent light transmittance over a wide range of wavelengths. Alternatively, it can also be produced by a known method (for example, an acidic solution in which tin chloride is dissolved is neutralized with an alkali to coprecipitate a hydroxide, and the coprecipitate is dried). The tin hydroxide powder is preferably ultrafine particles having an average primary particle size of 0.2 μm or less. When the particle diameter is 0.2 μm or less, a transparent film is obtained, but when it exceeds 0.2 μm, the transparency of the obtained film tends to be lowered. However, for applications in which the transparency of the resulting transparent film is not important, tin hydroxide powder having a particle size larger than 0.2 μm can also be used. In addition, although the crystallinity of the tin hydroxide used is judged by X-ray diffraction analysis and is preferably in an amorphous state, a part thereof may be crystallized. The green compact resistance of tin hydroxide is preferably 1 × 10 ⁹ Ω · cm or less.

  As a dopant that can be used in the present invention, a tin hydroxide powder containing at least one of P, Al, In, Zn, and Sb can be obtained as a commercial product, and a known method (for example, each of phosphorus and tin). An acidic solution in which a chloride is dissolved is neutralized with an alkali to coprecipitate phosphorus / tin hydroxide, and the coprecipitate is dried. In the tin hydroxide powder containing at least one of P, Al, In, Zn and Sb as the dopant, the amount of dopant relative to (dopant + Sn) is preferably in the range of 0.1 to 20 at%, More preferably, it is within the range of 15 at%. When the dopant content is out of this range, the resistance of the dopant-containing tin hydroxide particles themselves increases, so that the conductivity of the formed film tends to decrease. The tin hydroxide powder containing at least one of P, Al, In, Zn, and Sb as the dopant is preferably ultrafine particles having an average primary particle diameter of 0.2 μm or less as described above.

  In the composition for forming an electroconductive antiglare film of the present invention, it is selected from the group consisting of tin hydroxide powder itself and tin hydroxide powder containing at least one of P, Al, In, Zn and Sb as a dopant. The mass ratio of tin hydroxide powder (hereinafter simply referred to as tin hydroxide powder) and binder component (tin hydroxide powder / binder component) is preferably in the range of 5/95 to 95/5. More preferably, it is in the range of 15/85 to 90/10, most preferably in the range of 25/75 to 85/15. When the amount of tin hydroxide powder is less than 5/95 in the above mass ratio, the resulting film tends to be poor in conductivity even if the film has sufficient transparency. On the contrary, when the tin hydroxide powder is more than 95/5 in the above mass ratio, the dispersibility of the powder is deteriorated, the transparency of the obtained conductive film and the adhesion to the substrate are lowered, and the film performance is reduced. There is a tendency to decrease.

  In the composition for forming a conductive antiglare film of the present invention, as the light-transmitting fine particles, for example, at least one selected from the group consisting of an inorganic filler and a resin filler can be used. Examples of the inorganic filler include a filler made of silica, alumina, talc, zirconia, zinc oxide, or titanium oxide. An inorganic filler with poor translucency can be made translucent by atomization. Moreover, as a resin filler, the filler which consists of an acrylic resin, a polystyrene resin, a polyethylene resin, an epoxy resin, or a silicone resin can be mentioned, for example. Commercially available products can be used as such translucent fine particles. The shape of the translucent fine particles is preferably spherical. Moreover, it is preferable that the particle diameter of a translucent fine particle is 0.1-10 micrometers, and it is more preferable that it is 2-8 micrometers. By using these particles to form a film having a uniform concavo-convex shape, or by forming a film having internal haze using a finely divided inorganic filler or a resin filler, Antiglare property can be imparted. Further, when the total mass of the tin hydroxide powder and the binder component is X and the mass of the light-transmitting fine particles is Y, the mass ratio of X / Y is within the range of 99.9 / 0.1 to 50/50. It is necessary to be within the range of 99/1 to 80/20. When the amount of the light-transmitting fine particles is less than the above X / Y mass ratio range, the resulting conductive anti-glare film is insufficient in the effect of diffusing light, so that high transparency and conductivity are obtained. However, it is difficult to obtain a sufficient antiglare effect. Further, when the amount of the light-transmitting fine particles is larger than the above X / Y mass ratio range, the anti-glare property is improved in the obtained conductive anti-glare film, but the haze value becomes too high and the transmitted image is The sharpness is lowered and the light transmittance is lowered.

  In the composition for forming an electroconductive antiglare film of the present invention, any binder component that can be dissolved in a solvent used, can disperse tin hydroxide powder and translucent fine particles, and can form a film is generally used. Any binder component used in paints can be used without particular limitation. For example, alkyd resin, polyester resin, unsaturated polyester resin, polyurethane resin, acrylic resin, epoxy resin, phenol resin, vinyl resin, silicone resin, fluorine resin, phthalic acid resin, amino resin, polyamide resin, polyacryl silicone resin, melamine A resin, a urea resin, or a binder resin obtained by modifying these can be used alone or in combination of two or more.

  Further, the binder component may contain a cross-linking agent as required. For example, basic functional groups such as amino groups, neutral functional groups such as OH groups, acidic functional groups such as carboxyl groups, isocyanates, etc. Any crosslinking agent having two or more reactive functional groups such as a group in one molecule can be used.

  The binder component may be a radical polymerizable monomer, and may be a basic group such as an amino group as long as it is a monomer having a radical polymerizable unsaturated group (α, β-ethylenically unsaturated group). Any of those having a functional group, those having a neutral functional group such as an OH group, those having an acidic functional group such as a carboxyl group, or those not having such a functional group may be used.

  Furthermore, you may mix | blend various conventional additives in the composition for conductive anti-glare film formation of this invention in the range which does not impair the objective. Examples of such additives include a dispersant, a dispersion aid, a polymerization inhibitor, a curing catalyst, an antioxidant, and a leveling agent.

  In the composition for forming a conductive antiglare film of the present invention, the binder component can be dissolved or dispersed, and tin hydroxide powder and translucent fine particles can be dispersed, but the solvent does not attack the substrate. For example, any solvent generally used in paints can be used without particular limitation. For example, hydrocarbons such as hexane, heptane, cyclohexane, toluene and m-xylene, halogenated hydrocarbons such as tetrachloromethane and trichloroethylene, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, isophorone and cyclohexane, diethyl ether , Ethers such as dioxane and tetrahydrofuran, esters such as ethyl acetate, butyl acetate and isoamyl acetate, methanol, ethanol, n-propanol, isopropanol, n-butanol, n-pentanol, 2-ethylhexanol, cyclohexanol, diacetone alcohol , Alcohol such as ethylene glycol, propylene glycol, diethylene glycol, glycerin, ethylene glycol monoethyl ether, ethylene glycol Use ether / alcohol or ether / ester such as coal monobutyl ether, ethylene glycol monoethyl ether acetate, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, or a mixture thereof. Can do. About the usage-amount of such a solvent, it adjusts so that the viscosity of the composition finally obtained by disperse | distributing a tin hydroxide powder and translucent fine particles may become a thing suitable for application | coating or printing. In the composition for forming a conductive antiglare film of the present invention, the viscosity is preferably in the range of 2 to 10000 cps (E-type viscometer: 20 ° C.).

  The composition for forming an electroconductive antiglare film of the present invention comprises, for example, dispersing tin hydroxide powder and translucent fine particles in a binder component solution diluted by adding an organic solvent to the binder component as necessary. Can be manufactured. Moreover, it can manufacture also by disperse | distributing a tin hydroxide powder and translucent microparticles | fine-particles in an organic solvent, and adding and dispersing the said binder component after that. Of course, it can also be produced by simultaneously mixing and dispersing the four components of the binder component, tin hydroxide powder, translucent fine particles and organic solvent. Such a dispersion operation can be performed by a conventional method using a paint shaker, a ball mill, a sand mill, a sentry mill, a triple roll or the like. Of course, it can also be dispersed by a normal stirring operation.

  As a substrate on which the composition for forming a conductive antiglare film of the present invention is applied to form the conductive antiglare film of the present invention, various synthetic materials widely used in various fields including electric and electronic devices are used. Resins, glass, ceramics and the like can be mentioned, and these can be any shape such as a sheet shape, a film shape, and a plate shape. Specific examples of the synthetic resin include, but are not limited to, polyethylene, polypropylene, polycarbonate, acrylic resin, methacrylic resin, polyvinyl chloride, polyester resin, polyamide resin, and phenol resin.

  Application or printing of the composition for forming a conductive antiglare film of the present invention on a substrate can be performed by a conventional method such as roll coating, spin coating, or screen printing. Thereafter, the coating film is cured. The binder component is polymerized to form a conductive antiglare film in which tin hydroxide powder and translucent fine particles are bonded with a resin. In general, the thickness of the conductive antiglare film is preferably in the range of 0.5 to 10 μm, and more preferably in the range of 2 to 8 μm.

The conductive antiglare film of the present invention formed on the substrate from the composition for forming a conductive antiglare film of the present invention has, for example, a surface resistance value of preferably 10 ⁷ to 10 ¹² Ω / □, more preferably 10 ⁷ to 10 ¹¹ Ω / □, light transmittance is preferably 85% or more, haze is preferably 3 to 50%, more preferably 8 to 40%, and any of transparency, conductivity, and antiglare properties It becomes an excellent conductive antiglare film. Such a conductive antiglare film can be used as a dust prevention film for electrophotographic recording or as an antistatic film, and can be used, for example, on a display surface of a display.

The present invention will be specifically described below with reference to examples and comparative examples. The tin hydroxide powder used in the examples is particles having an average primary particle diameter of 0.05 μm, the powder resistance is 1 × 10 ⁷ Ω · cm, and the tin hydroxide powder containing phosphorus as a dopant is The amount of P with respect to Sn + P was 5.0 at%, and the average primary particle size was 0.05 μm. In Examples and Comparative Examples, “parts” are all “parts by mass”.

Example 1
230 parts of an acrylic resin solution (Dianar LR-90, solid content 30%, trade name, manufactured by Mitsubishi Rayon Co., Ltd.) as a binder component, 30 parts of tin hydroxide powder, 150 parts of isopropyl alcohol as a solvent, and glass beads 250 The mixture was placed in a container together with the part, and kneaded for 5 hours with a paint shaker while confirming the dispersion state with a particle gauge. After kneading, the glass beads were removed to obtain a viscous liquid. Furthermore, translucent fine particle dispersion obtained by dispersing silophobic # 200 (inorganic filler, particle diameter: 4.0 μm, manufactured by Fuji Silysia Co., Ltd.), which is a translucent fine particle, in isopropyl alcohol. 50 parts of a liquid (NV. 20%) was added. Thereafter, the viscous liquid material was applied onto a 75 μm-thick PET film (Toyobo A4300, light transmittance 91%, haze 0.7%) using a roll coater, and the organic solvent was evaporated. A conductive antiglare film having a thickness of 3 μm was produced by drying at 10 ° C. for 10 minutes.

Example 2
An organic filler MX-300 (particle size: 2.8 μm, manufactured by Soken Chemical Co., Ltd.) is used in place of 50 parts of a light-transmitting fine particle dispersion (NV. 20%) in which silophobic # 200 is dispersed in isopropyl alcohol. A conductive antiglare film having a thickness of 2.5 μm was prepared in the same manner as in Example 1 except that 100 parts of a light transmissive fine particle dispersion (NV. 10%) dispersed in alcohol was added.

Example 3
A thickness of 3 μm was processed in the same manner as in Example 1 except that the addition amount of translucent fine particle dispersion (NV. 20%) in which Silo Hovic # 200 was dispersed in isopropyl alcohol was changed from 50 parts to 100 parts. A conductive antiglare film was prepared.

Example 4
A conductive antiglare film having a thickness of 3 μm was produced in the same manner as in Example 1 except that 30 parts of tin hydroxide powder containing phosphorus was added as the above dopant instead of 30 parts of tin hydroxide powder.

Example 5
30 parts of tin hydroxide powder, 200 parts of butyl acetate as a solvent and 250 parts of glass beads were placed in a container and kneaded for 5 hours while confirming the dispersion state with a particle gauge using a paint shaker. After kneading, the glass beads are removed, and the dispersion is 70 parts acrylic resin (Dianar HR-633, solid content 50%, trade name, manufactured by Mitsubishi Rayon Co., Ltd.) as a binder component and melamine resin (Uban 225, solid content). 60%, Mitsui Chemicals Co., Ltd. product name) 58 parts and mixed with a disperser while sufficiently stirring to obtain a viscous liquid. Furthermore, 50 parts of a translucent fine particle dispersion (NV. 20%) in which the above-described silophobic # 200, which is a translucent fine particle, was dispersed in isopropyl alcohol was added to the viscous liquid. Thereafter, the viscous liquid material was applied onto a 75 μm-thick PET film (Toyobo A4300, light transmittance 91%, haze 0.7%) using a roll coater, and the organic solvent was evaporated. A conductive antiglare film having a thickness of 3 μm was produced by drying at 15 ° C. for 15 minutes.

Example 6
The amount of acrylic resin solution (Dianar LR-90, solid content 30%, trade name, manufactured by Mitsubishi Rayon Co., Ltd.) as a binder component was changed from 230 parts to 100 parts, and the amount of tin hydroxide powder was changed from 30 parts. A conductive antiglare film having a thickness of 5 μm was produced in the same manner as in Example 1 except that the amount was changed to 70 parts.

Comparative Example 1
A conductive antiglare film having a thickness of 5 μm was prepared in the same manner as in Example 1 except that 30 parts of ITO powder was used instead of 30 parts of tin hydroxide powder.

Comparative Example 2
A conductive antiglare film having a thickness of 5 μm was prepared in the same manner as in Example 1 except that 30 parts of tin oxide powder was used instead of 30 parts of tin hydroxide powder.

Comparative Example 3
A conductive antiglare film having a thickness of 3 μm was prepared in the same manner as in Example 1 except that the light-transmitting fine particle dispersion was not added.

Comparative Example 4
A conductive antiglare film having a thickness of 3 μm was prepared in the same manner as in Example 1 except that the addition amount of the translucent fine particle dispersion (NV. 20%) was changed from 50 parts to 600 parts.

Comparative Example 5
A conductive antiglare film having a thickness of 3 μm was prepared in the same manner as in Example 1 except that the addition amount of the translucent fine particle dispersion (NV. 20%) was changed from 50 parts to 0.25 parts.

  About the electroconductive glare-proof film | membrane obtained by the Example and the comparative example, the whole line light transmittance and haze were measured by TC-HIII DPK by Tokyo Denshoku Technical Center. The measured value is a value including the base material. Further, the surface resistance value was measured with a Hiresta IP MCP-HT260 surface resistor manufactured by Mitsubishi Chemical Corporation. The measurement results are summarized in Table 1.

  In Table 1, P means conductive powder (such as tin hydroxide powder), B means binder component, X means total mass of conductive powder and binder component, and Y means It means the mass of translucent fine particles.

As is clear from the data shown in Table 1, when the composition for forming a conductive antiglare film of the present invention containing tin hydroxide powder and translucent fine particles was applied (Examples 1 to 6). Has a surface resistivity of 10 ⁷ to 10 ¹² Ω / □, a light transmittance of 85% or more, and a haze of 3 to 50%, which is excellent in transparency, conductivity, and antiglare properties. A film was obtained, which sufficiently satisfied the functions of the optical film for FPD. When the composition for electrically conductive film formation containing the ITO powder or the tin oxide powder was applied (Comparative Examples 1-2), the light transmittance was less than 85%. Moreover, when the addition amount of the translucent fine particles was not in an appropriate range (Comparative Examples 3 to 5), the desired antiglare function was not obtained.

It is a graph which shows the correlation with the wavelength and light transmittance of various electroconductive powder.

Claims (8)

It consists of a binder component and tin hydroxide [Sn (OH) ₄ ] powder and translucent fine particles dispersed in the binder component. The total mass of the tin hydroxide powder and the binder component is X, A composition for forming a conductive antiglare film, wherein the mass ratio of X / Y is in the range of 99.9 / 0.1 to 50/50 when the mass is Y.   The composition for forming a conductive antiglare film according to claim 1, wherein the mass ratio of the tin hydroxide powder / binder component is in the range of 5/95 to 95/5.   The composition for forming an antiglare film according to claim 1 or 2, wherein the translucent fine particles are at least one selected from the group consisting of an inorganic filler and a resin filler.   The conductive antiglare film according to any one of claims 1 to 3, wherein the tin hydroxide powder is a tin hydroxide powder containing at least one of P, Al, In, Zn and Sb as a dopant. Forming composition.   The amount of at least one dopant of P, Al, In, Zn, and Sb is 0.1 to 20 at% with respect to (dopant + Sn), for forming a conductive antiglare film according to claim 4 Composition.   A conductive antiglare film obtained by applying or printing the composition for forming a conductive antiglare film according to claim 1, and drying the composition. 7. The conductive antiglare film according to claim 6, having a surface resistance value of 10 ⁷ to 10 ¹² Ω / □, a light transmittance of 85% or more, and a haze of 3 to 50%.   A display comprising the conductive antiglare film according to claim 6 on a display surface.

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