JPH054763B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention forms a non-glare conductive film with excellent scratch resistance and durability on a transparent substrate such as glass or plastic at a low temperature without impairing the transparency of the substrate. The present invention relates to a transparent conductive coating liquid composition and a transparent substrate on which a conductive film is formed using the same. [Prior Art] Glass or plastic is a base material with particularly excellent transparency, and is therefore widely used as a material for display devices, such as cathode ray tubes (CRTs), liquid crystal display (LCD) substrates, and display windows. However, glass or plastic itself is an insulator and tends to accumulate static electricity on its surface, making it difficult to view images due to the accumulation of dirt and dust. Furthermore, electrostatic displays such as LCDs sometimes malfunction due to static electricity. Methods of making glass or plastic conductive and preventing static electricity include applying a conductive paint containing conductive powder and binder resin dispersed in a solvent, and spraying organic tin such as tin chloride or tin alkoxide. , vapor phase methods such as PVD and CVD (electronic conductivity), and methods of spraying surfactants, silicon alkoxide, etc. (ionic conductivity). However, although electronically conductive materials have sufficient conductivity, they have poor transparency, scratch resistance, solvent resistance (the binder resin is attacked by solvents and the coating surface turns white), and water resistance (the film peels off).・
The transparency is good, but the acid resistance, alkali resistance,
The water resistance is poor (the film peels off in all three cases), and the material that forms the film itself has a high refractive index, and the film surface is smooth, creating a glare that makes it difficult to see the image. Furthermore, if a Patsushipacin membrane is not used in combination, the alkali ions in the glass will migrate to the membrane during firing, reducing the conductivity, or the firing temperature will exceed 500°C.
If the temperature is below 0.degree. C., the alkali resistance decreases and the conductivity deteriorates. Also, the odor and corrosiveness of gas (droplets)
Explosiveness poses problems in the working environment, and in addition to poor abrasion resistance, the cost is high, and if the base material has a curved surface or a large area, a body-shaped device is required. The conductivity of ion conductive materials changes depending on the temperature and humidity environment, and their scratch resistance, alkali resistance (the film dissolves), and water resistance (peeling off) are poor. [Problems to be Solved by the Invention] The present invention attempts to solve the above-mentioned problems associated with the prior art. On the other hand, a non-glare conductive coating with excellent scratch resistance, acid resistance, alkali resistance, solvent resistance, and water resistance (hereinafter referred to as durability) without impairing the transparency of the base material can be produced at low temperatures. The object of the present invention is to provide a transparent conductive coating liquid composition to be formed and a transparent base material on which a transparent conductive coating obtained by coating and curing the same is formed. [Means for Solving the Problems] The present invention involves uniformly dispersing a zirconium oxysalt, non-precipitating silica, and conductive tin oxide colloid in water, a growth inhibitor, and a diluent to form a transparent substrate such as glass. scratch resistance and scratch resistance without impairing the transparency of the base material.
A transparent conductive coating liquid composition that forms a highly durable and non-glare conductive film at low temperatures, and a transparent substrate having a transparent conductive film obtained by coating and curing the same. In the present invention, a matrix is made of a mixture of zirconia obtained from a zirconium oxysalt and silica obtained from a non-precipitated silica, and conductive tin oxide colloidal particles are dispersed in the matrix to form a transparent coating with conductivity. This is a transparent conductive coating liquid composition that forms a transparent conductive coating composition. The glare of a coating depends on the reflectance of the coating. The reflectance of a coating is determined by its refractive index and the shape of its surface, which in turn depends on the material that makes up the coating and the density of the coating. Therefore, in order to lower the reflectance, it is sufficient to use only a substance with a low refractive index, or to mix a substance with a high refractive index with a substance with a low refractive index, or to reduce the density of the coating. Next, regarding the shape of the coating surface, the higher the smoothness, the higher the reflectance, so it is best to reduce the smoothness, but if the smoothness decreases too much, the transparency of the coating will also decrease at the same time.
Therefore, in the present invention, silica (refractive index 1.5) is added to zirconia (refractive index 2.2) to eliminate glare from the coating.
The refractive index of the matrix itself is lowered by mixing these materials, the coating is made porous to lower its apparent refractive index, and the surface of the coating is made uneven to the extent that transparency is not reduced to eliminate glare.
However, in general, when a coating becomes porous, its surface area increases compared to a smooth coating, resulting in poor durability. Zirconia is a highly durable material, and zirconia coatings are generally obtained using zirconium alkoxide. However, since zirconium alkoxide has a fast hydrolysis rate, it is difficult to control the rate, and when it is applied as a coating liquid to a transparent substrate, it is easily affected by humidity, and the properties of the film vary depending on the humidity. It is difficult to continuously obtain a film with constant properties. Furthermore, since it is hydrolyzed by a small amount of water, the coating solution cannot be stored for a long period of time. Furthermore, zirconium alkoxide is expensive and therefore costs high as a raw material for industrial products. The present invention solves the conventional problems by using a zirconium salt. As the zirconium salt according to the present invention, an oxy salt is used, and zirconium oxychloride and zirconium oxynitrate are particularly preferred. Even if a zirconium oxysalt is applied in the form of an aqueous solution to a substrate such as glass, the aqueous solution is repelled and no film is formed. This is caused by the low film-forming properties of the zirconium oxysalt and the high surface tension of the aqueous solution with respect to the substrate. First, non-precipitating silica was added to improve the film-forming properties. In order to lower the surface tension, it is necessary to mix an organic solvent with a low surface tension, or to remove part of the water from the system after mixing. However, with ordinary organic solvents, zirconium oxysalts and non-precipitated silica become unstable when the water content decreases, and may decompose to cause gelation or promote polymerization. In the present invention, as a result of examining the above-mentioned zirconium oxysalts and organic solvents that can act as growth inhibitors by preventing the decomposition and gelation of non-precipitated silica, we have selected zirconium oxysalts from among various organic solvents. The above problems can be solved by mixing a specific organic solvent with a mixed aqueous solution of non-sedimentable silica and conductive tin oxide colloidal particles, or by dehydrating part of the water from the system after mixing. I found a headline. The coating liquid composition prepared in this manner is stable even when the water content is low because the zirconium oxysalt and non-precipitating silica do not gel or polymerize because the organic solvent acts as a growth inhibitor. Moreover, at the same time, it is possible to improve film-forming properties and reduce the surface tension of the coating liquid composition. When it is further diluted with a diluent and applied to the substrate, the diluent, water and some of the growth inhibitors evaporate, and the remaining growth inhibitor decomposes and gels the zirconium oxysalt and non-precipitating silica. and when polymerization is suppressed and the remaining growth inhibitor gradually evaporates,
Polymerization of the zirconium oxysalt and non-precipitating silica occurs to form a film. The reason why the film-forming property is improved by non-precipitated silica is probably that when the growth inhibitor gradually evaporates, the hydroxyl groups of non-precipitated silica promote polymerization with zirconium oxysalt. I think it's for a reason. The conductive tin oxide colloid particles according to the present invention are:
These are colloidal particles in which tin oxide, tin oxide doped with a different element, or both are dispersed in water or an organic solvent. Production method"
These are conductive tin oxide colloidal particles obtained by the invention of (Japanese Patent Application No. 61-75283). The average particle size of the colloidal particles is preferably in the range of 0.01 to 0.1 μm. If it is less than 0.01 μm, the film cannot be made porous, and if it exceeds 0.1 μm, the resulting film will have a high haze value (hereinafter referred to as haze), impairing the transparency of the substrate. However, even if the average particle size is 0.1 μm or less, if there are many particles exceeding 0.1 μm, the haze of the coating will increase and the transparency of the substrate will decrease. It is preferable that at least % is occupied by particles with a particle size of 0.1 μm or less. The non-precipitating silica according to the present invention is obtained by exchanging alkali and hydrogen in an aqueous alkali silicate solution by a method such as an ion exchange method or a _dialysis method. of
When centrifuged at 250,000 G for 1 hour, the amount of precipitate is 30 parts by weight, preferably 10 parts by weight or less, based on the total SiO ₂ in the aqueous solution. Preferably, "Non-precipitating silica composition for coating and method for producing the same" previously filed by the present applicant (Japanese Patent Application No. 187835/1983)
The non-precipitating silica obtained by the invention of No. 1) is used. The non-sedimented silica thus obtained is inherently unstable and prone to regelation in which colloidal particles are produced, but is stabilized by the growth inhibitor in the coating composition. Furthermore, this non-precipitating silica does not gel when mixed with zirconium oxysalts, nor does it gel zirconium oxysalts. The growth inhibitor according to the present invention is one that does not gel zirconium oxysalt and non-precipitated silica or does not promote polymerization, preferably N-methyl-2-pyrrolidone, N,N
Dimethylformamide, morpholine, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol, etc., and their derivatives can be used singly or in combination of two or more. The diluent according to the present invention may be any diluent that does not cause gelation of the zirconium oxysalt and non-precipitating silica, such as methanol, ethanol, n
- One or more alcohols such as propanol, i-propanol, n-butanol, i-butanol, and t-butanol, acidic esters such as methyl acetate and ethyl acetate, ethers such as diethyl ether, and ketones such as acetone. Can be used in combination. The composition ratio of ZrO ₂ , SiO ₂ , conductive tin oxide colloidal particles, moisture, growth inhibitor, and diluent is as follows: First, the growth inhibitor is 1≦( as a molar ratio to the total of ZrO ₂ and SiO ₂ Growth inhibitor)/ZrO ₂ +SiO ₂ )≦25
is good. Preferably the number is 2 or more. If it is less than 1, the pot life (usable period) of the coating solution will be shortened and it cannot be stored for a long time. If it exceeds 25, when the coating liquid composition is applied and cured, the curing becomes uneven and the durability of the coating deteriorates. Second, water has a weight ratio of 0.1≦H ₂ O/ZrO ₂ to ZrO ₂ .
After satisfying the condition of ≦40, it is preferably 50 wt% or less based on the total weight of the coating liquid composition (hereinafter referred to as the total weight). If it is less than 0.1, gelation of the zirconium oxysalt will occur, and if the weight ratio exceeds 40 or 50 wt% of the total weight, the growth inhibitor will be ineffective and the coating composition will be repelled on the transparent substrate. be. Thirdly, the total weight of ZrO ₂ , SiO ₂ and conductive tin oxide colloid is relative to the total weight,
It is preferably 0.1 to 20 wt%, and 0.1 to 10 wt% is good in terms of long-term storage stability of the coating solution. This is because if it exceeds 20 wt%, the stability of the coating solution deteriorates and it easily gels. Fourth, the ratio of conductive tin oxide colloidal particles, zirconium oxysalt, and non-precipitating silica,
1≦(conductive tin oxide colloidal particles)/(ZrO ₂ +
SiO ₂ )≦5 (weight ratio) is preferable. If it is less than 1, the conductivity of the film will be poor or the film will not become porous, and if it exceeds 5, the adhesion of the film will be reduced. Fifth, the ratio of non-precipitating silica to zirconium oxysalt is preferably 0.05≦SiO ₂ /ZrO ₂ ≦1 (weight ratio). This is because if it is less than 0.05, the adhesion of the film will be poor, and if it exceeds 1, the durability of the film will be poor. The diluent may be added so that the transparent conductive coating composition of the present invention has a viscosity suited to the coating method or a desired film thickness. The method for producing the transparent conductive coating liquid composition of the present invention includes:
As a preferred but not particularly limited method, a portion of the water is dehydrated from a mixed solution in which zirconium oxysalt, non-precipitating silica, and conductive tin oxide colloidal particles are dispersed in water and a growth inhibitor, or without dehydration. A diluent may be added to the water, and a distillation method or an ultrafiltration method can be used to dehydrate the water. The transparent conductive coating composition of the present invention can be applied to a substrate such as glass by a conventionally known coating method, such as a spinner method, a barcode method, a dip method, a spray method, a roll coating method, or a printing method. A film with good durability and mechanical strength can be obtained by applying the coating with a 300°C or higher temperature and below the glass transition point of the base material. It should be fired at a certain temperature. The film obtained in this way has a total light transmittance (T _t ) of 90% or more and a haze (H) of 5 or less, so it does not impair the transparency of the transparent substrate and has a surface resistance of 10 ⁴ to 10 ⁹ Ω/□
Therefore, it has an excellent antistatic effect and prevents glare. Also, it is not affected by acids and alkalis, and is resistant to water,
It can withstand salt water and has excellent adhesion, with no change in the film. Suitable transparent substrates include processed glass products such as glass plates and CRTs, sheets of polyethylene terephthalate, polycarbonate, poly(meth)acrylate, etc., and processed products thereof. Note that when applied to a colored substrate, a film can be formed without changing the color tone of the substrate. The conductive glass or plastic obtained using the conductive coating liquid composition of the present invention can be applied to antistatic display panels, copy glass, instrument display panels, transparent digitizers, telewriting terminals, etc. EXAMPLES The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples. [Example] Example 1 316 g of potassium stannate and 38.4 g of tartarite were mixed with 686 g of water.
A raw material solution was prepared by dissolving it in g. The above raw material solution was added over 12 hours together with nitric acid to 1000 g of water heated to 50° C. and stirred, and the system was hydrolyzed while maintaining the pH at 8.5 to obtain a sol. Colloidal particles were filtered from this sol, washed to remove by-product salts, and then dried, calcined in air at 350℃ for 3 hours, and further calcined in air at 650℃ for 2 hours to obtain a fine powder. Ta. 400 g of the obtained powder was added to 1600 g of an aqueous potassium hydroxide solution (containing 40 g of KOH), and the mixture was stirred in a sand mill for 3 hours while maintaining the mixture at 30° C. to obtain a conductive tin oxide colloid. Next, this conductive tin oxide colloid was treated with an ion exchange resin to obtain a dealkalized conductive tin oxide colloid (conductive sol). The dealkalized conductive tin oxide colloid here does not contain precipitates,
The solid content concentration was 20 wt%, and the average particle size of the colloid particles was 0.07 μm. The amount of particles of 0.1 μm or less was 87% of the total particles. 5wt% sodium silicate as SiO ₂ (SiO ₂ /Na ₂ O=
3 mol/mol) was passed through a hydrogen type ion exchange resin column at a space velocity of SV=5 while maintaining the temperature at 15°C (non-precipitating silica liquid). 50g of this non-precipitating silica liquid and 50g of the conductive sol are
-20g of methyl-2-pyrrolidone and 10g of 25wt% zirconium oxychloride aqueous solution converted to _ZrO2
g and 170 g of MeOH/BuOH (weight ratio 1/1) were added and thoroughly mixed to obtain a transparent conductive coating liquid composition. Example 2 50g of the non-sedimentable silica liquid obtained in Example 1
To 200 g of the conductive sol, add 10 g of N-methyl-2-pyrrolidone, 40 g of a 25 wt% zirconium oxychloride aqueous solution in terms of ZrO ₂ and 1400 g of MeOH/EtOH (weight ratio 1/1) and disperse thoroughly. A transparent conductive coating liquid composition was obtained. Example 3 10g of N-methyl-2-pyrrolidone and MeOH/
A transparent conductive coating liquid composition was obtained under the same conditions as in Example 1 except that 380 g of BuOH (weight ratio 1/1) was used. Example 4 50 g of the non-precipitating silica liquid obtained in Example 1, 220 g of conductive sol, 110 g of N-methyl-2-pyrrolidone, 100 g of 25 wt% zirconium oxychloride aqueous solution in terms of ZrO ₂ and MeOH /EtOH (weight ratio 1/1) was added and sufficiently dispersed to obtain a transparent conductive coating composition. Example 5 After homogeneously mixing 50 g of the non-precipitating silica liquid obtained in Example 1, 100 g of the conductive sol, 150 g of N,N dimethylformamide, and 30 g of a 25 wt% zirconium oxynitrate aqueous solution in terms of ZrO ₂ The mixture was heated to 80° C. under reduced pressure using a rotary evaporator, and 135 g of water was distilled out. This liquid was cooled, and 405 g of MeOH/BuOH (weight ratio 1/1) was added and sufficiently dispersed to obtain a transparent conductive coating liquid composition. Example 6 A transparent conductive coating liquid composition was obtained under the same conditions as in Example 1 except that 20 g of ethylene glycol monomethyl ether was used. Example 7 A transparent conductive coating liquid composition was obtained under the same conditions as in Example 1 except that morpholine was replaced with 20 g. Comparative Example 1 200g of non-sedimentable silica liquid obtained in Example 1
After homogeneously mixing 125 g of conductive sol, 50 g of N-methyl-2-pyrrolidone, and 10 g of a 25 wt% oxysalt zirconium aqueous solution in terms of ZrO ₂ , the mixture was heated to 80°C under reduced pressure using a rotary evaporator and water was added. 210g of was distilled out. Cool this liquid and further
1075 g of MeOH/BuOH (weight ratio 1/1) was added and sufficiently dispersed to obtain a transparent conductive coating composition. Comparative Example 2 100g of non-sedimentable silica liquid obtained in Example 1
Add 25 g of conductive sol, 40 g of N-methyl-2-pyrrolidone, 20 g of 25 wt% zirconium oxychloride aqueous solution in terms of ZrO ₂ and 115 g of MeOH/BuOH (weight ratio 1/1) and disperse thoroughly. A transparent conductive coating liquid composition was obtained. Comparative Example 3 100g of the non-precipitating silica liquid obtained in Example 1
After homogeneously mixing 350 g of conductive sol, 40 g of N-methyl-2-pyrrolidone, and 20 g of a 25 wt% zirconium oxynitrate aqueous solution in terms of ZrO ₂ , the mixture was heated to 80°C under reduced pressure using a rotary evaporator and water was added. 250g was distilled out. This liquid was cooled, and 1340 g of MeOH/BuOH (weight ratio 1/1) was added and sufficiently dispersed to obtain a transparent conductive coating liquid composition. Comparative Example 4 500g of non-sedimentable silica liquid obtained in Example 1
to 500g of the conductive sol, N-methyl-2-
After uniformly mixing 6 g of pyrrolidone and 100 g of a 25 wt% zirconium oxynitrate aqueous solution in terms of ZrO ₂ , the mixture was heated to 80°C under reduced pressure using a rotary evaporator.
When heated to 900g to distill out 900g of water, it turned into a gel. Comparative Example 5 100g of non-sedimentable silica liquid obtained in Example 1
To 100 g of the conductive sol, add 25 g of N-methyl-2-pyrrolidone, 100 g of a 5 wt% zirconium oxychloride aqueous solution in terms of ZrO ₂ and 75 g of MeOH/BuOH (weight ratio 1/1) and disperse thoroughly. A transparent conductive coating liquid composition was obtained. The liquid compositions and composition ratios of Examples and Comparative Examples are shown below.
Shown in 1. Using a spinner, the coating liquid compositions obtained in Examples 1 to 5 and Comparative Examples 1 to 3 and 5 were applied to a glass plate, and the transparent conductive coating liquid compositions obtained in Examples 6 and 7 were applied to an acrylic plate. It was applied at 2000r.pm. The glass plate is 110
After drying at 110°C for 10 minutes, it was fired at 300°C for 30 minutes, and the acrylic plate was dried at 110°C for 30 minutes to obtain a coating. In addition, 20ml/20ml of the transparent conductive coating composition obtained in Example 1 was sprayed onto a 14-inch cathode ray tube panel maintained at 60°C at a spray supply air pressure of 1.5Kg/ ^cm2 .
Sprayed in minutes. Then dry at 110℃ for 10 minutes.
A film was obtained by firing at 450°C for 30 minutes. Example of this
Let it be 1′. The obtained film was evaluated as follows. The results are shown in Tables 2 and 3. Transparency: total light transmittance (T _t ) and haze (H)
was measured using a haze computer (manufactured by Suga Test Instruments). Glossiness: Glossiness (G) was evaluated at a measurement angle of 60° according to the glossiness measurement method of JISK 7105-81. Adhesion: A part of commercially available cellophane tape with a width of 12 mm was attached to the film, the rest was held at right angles to the film, and it was instantly peeled off, and the presence or absence of the film on the glass was visually observed. Hardness: Measured using JISDO 202-71 pencil hardness test. Surface resistance: The glass plate and acrylic plate were measured using an electrode cell (manufactured by YHP). In addition, the 14-inch panel was measured using Hiresta (manufactured by Mitsubishi Yuka). Durability: After soaking in the following four types of liquids, adhesion (same as) was evaluated, and gloss and surface resistance (same as .) were compared before and after the test. (1) 120 hours at room temperature in 15wt% ammonia water. (2) 120 hours at room temperature in 10wt% NaCl aqueous solution. (3) Place in boiling water for 30 minutes. (4) 120 hours at room temperature in 50 wt% acetic acid aqueous solution. [Effects of the Invention] By adopting the above configuration, the present invention can provide a conductive coating with excellent durability, mechanical strength, and adhesion to transparent substrates such as glass without impairing the transparency of the substrate. It can be formed at low temperatures. Furthermore, the pot life (usable period) of the coating liquid composition of the present invention is as follows:
Stored at room temperature in the dark for 3 months or more. In addition, when surface smoothness is required for a base material having a transparent conductive coating, or when it is desired to reduce the surface friction coefficient, polyester,
A transparent protective film made of a resin such as acrylic, silicone, polypropylene, polyethylene, polystyrene, or epoxy, or an inorganic material such as silica can be provided.

【table】

【table】

[Table] Adhesion: ○ if the film does not peel off;
If it peeled off, it was marked as ×. Comparative example
In No. 5, the transparent conductive coating liquid composition was repelled and no film was obtained.

【table】

【table】

Claims (1)

[Claims] 1. A transparent conductive material characterized by uniformly dispersing a zirconium oxysalt, non-precipitating silica, and conductive tin oxide colloidal particles in a dispersion medium consisting of water, a growth inhibitor, and a diluent. Coating liquid composition. 2. As a growth inhibitor, use one type or a combination of two or more of N-methyl-2-pyrrolidone, N,N dimethylformamide, morpholine, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol, and their derivatives. The transparent conductive coating composition according to claim 1, characterized in that: 3. A patent claim characterized in that conductive tin oxide colloidal particles obtained by hydrotreating conductive tin oxide powder and/or conductive tin oxide powder doped with a different element in an acid aqueous solution or an alkaline aqueous solution are used. The transparent conductive coating liquid composition according to item 1 or 2. 4 Convert zirconium oxysalt to ZrO ₂ ,
Non-precipitated silica is converted to SiO ₂ and the composition of conductive tin oxide colloidal particles, water, growth inhibitor and diluent is calculated as follows: 1≦(growth inhibitor)/(ZrO ₂ +SiO ₂ )≦25 (mol)
ratio) 0.1≦H ₂ O / ZrO ₂ ≦40 (weight ratio) H ₂ O / (total weight of coating liquid composition) ≦0.5 (weight ratio) 0.001≦ (ZrO ₂ + SiO ₂ conductive tin oxide colloidal particles) / (Total weight of coating liquid composition)≦0.2 (weight ratio) 1≦(conductive tin oxide colloidal particles)/(ZrO ₂ +
The transparent conductive coating according to claim 1, 2 or 3, characterized in that SiO ₂ )≦5 (weight ratio) 0.05≦SiO ₂ /ZrO ₂ ≦1 (weight ratio) liquid composition. 5 A transparent coating made by coating a substrate with a coating solution in which zirconium oxysalt, non-precipitating silica, and conductive tin oxide colloid are uniformly dispersed in a dispersion medium consisting of water, a growth inhibitor, and a diluent, and then hardening the coating solution. A base material having a conductive coating.