JPS63143706A - Transparent conducting coat liquid composition and base material having transparent conducting film - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a method for producing transparent substrates such as glass or plastic that has excellent scratch resistance and durability without impairing the transparency of the substrate and is free from glare. The present invention relates to a transparent conductive coating liquid composition that forms a conductive film at low temperatures, and a transparent substrate on which a transparent conductive film is formed using the same.

[Conventional technology]

Glass or plastic is a base material with particularly excellent transparency, and is used as a material for display devices, such as cathode ray tubes (cRT).
It is widely used in liquid crystal display (LCD) substrates, show windows, etc.

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, electro-displays such as LCDs rarely malfunction due to static electricity. Methods of making glass or plastic conductive and preventing static electricity include: ■ Applying conductive paint containing conductive powder and binder resin dispersed in a solvent; ■ Spraying organic tin such as tin chloride or tin alkoxide. ■Methods such as vapor phase methods such as PVD and OVD (electronic conductivity) ■Methods of spraying surfactants, silicon alkoxide, etc. (ionic conductivity)
There is.

However, electronically conductive materials have sufficient conductivity, but in ■, 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).
For ■ and ■, the transparency is good, but the acid resistance, alkali resistance, and water resistance (the film peels off in all three categories) are poor, and the refractive index of the material itself that forms the film is high, and the film surface is Because it's smooth, there's a glare that makes it difficult to see the image.

Furthermore, if a passivation film is not used in conjunction with ■, the alkali ions in the glass will move into the film during firing and reduce the conductivity.If the firing temperature is below SOO℃, the alkali resistance will decrease and the conductivity will decrease. becomes worse. In addition, there are problems in the working environment due to the odor, corrosiveness, and explosiveness of the gas (droplets).
However, it has poor scratch resistance and is expensive, and requires large equipment if the base material has a curved surface or a large area. The conductivity of the ionic conductive material (■) changed depending on the environment such as temperature and humidity, and its scratch resistance, alkali resistance (the film melted), and water resistance (peeled off) were poor.

[Problem that the invention seeks to solve]

The present invention aims to solve the problems associated with the prior art as described above, and is aimed at reducing the transparency of a transparent base material such as glass or plastic (hereinafter referred to as glass). A transparent conductive coating liquid composition that forms a glare-free conductive film at low temperatures with excellent scratch resistance, acid resistance, alkali resistance, solvent resistance, and water resistance (the above four points are hereinafter referred to as durability). Another object of the present invention is to provide a transparent substrate having a transparent conductive film obtained by applying and curing the same.

[Means for solving problems]

The present invention improves the transparency of a transparent substrate such as glass by uniformly dispersing zirconium oxyacid, non-precipitating silica, and conductive oxide particles in water, a growth inhibitor, and a diluent. A transparent conductive coating liquid composition that forms a non-glare conductive film with excellent abrasion resistance and durability at low temperatures without impairing the properties, and a transparent substrate having a transparent conductive film obtained by applying and curing the same. It is.

In the present invention, a mixture of zirconia obtained from zirconium oxyacid salt and silica obtained from non-precipitated silica is used as a matrix, and conductive oxide particles are dispersed in the matrix, thereby creating a transparent and conductive material. This is a transparent conductive coating liquid composition that forms a film. The glare of a coating depends on the reflectance of the coating. The reflectance of a coating depends on 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 small refractive index, or to mix a substance with a large refractive index with a substance with a small 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, in order to eliminate glare from the coating, zirconia (refractive index 2.2) is mixed with 7 Lika (refractive index L5) to lower the refractive index of the matrix itself, and the coating is made porous. The apparent refractive index is lowered, and the coating surface 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 substance, and zirconia coatings are generally obtained using zircon alkoxide. However, since zircon 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 can be affected by humidity. It is difficult to continuously obtain a film with constant properties.

In addition, the coating liquid, which is hydrolyzed by trace amounts of water, cannot be stored for a long period of time. Furthermore, zircon alkoxide is expensive, so it is expensive to use as a raw material for industrial products. In the present invention, 11 conventional problems have been solved by using a zirconium salt.

As the zirconium salt according to the present invention, an oxyacid salt is used, and zirconium oxychloride and zirconium oxynitrate are particularly preferred.

Even when a zirconium oxyacid salt is applied in the form of an aqueous solution to a base material 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 oxy-acid salt and the high surface tension of the aqueous solution to the substrate, but first, non-precipitating silica was added to improve 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, when the amount of water is reduced, the zirconium oxyacid salt and the non-precipitated silica become unstable, and may decompose, causing gelation and promoting polymerization. In the present invention, as a result of examining the above-mentioned zirconium oxyacid salts and organic solvents that can act as growth inhibitors by preventing the decomposition and gelation of non-precipitated silica, we found that The above problems can be solved by mixing a specific organic solvent with a mixed solution of acid salts, non-precipitating silica, and conductive oxide powder, or by dehydrating some of the water from the system as if mixed. I found a headline. The coating liquid composition prepared in this way is stable even when the amount of water is reduced because the organic solvent acts as a growth inhibitor, without causing gelation or polymerization of the zirconium oxyacid salt and non-precipitating silica. At the same time, it is possible to improve film-forming properties and reduce the surface tension of the coating liquid composition. Furthermore, when diluted with a diluent and applied to a substrate, even if the diluent, water, and some of the growth inhibitor evaporate, the remaining growth inhibitor decomposes and decomposes the zirconium oxyacid and non-precipitating silica. When gelation and polymerization are suppressed and the remaining growth inhibitor gradually evaporates, polymerization of the zirconium oxyalt salt and the 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 the polymerization with zirconium oxyacid. I think so.

The conductive oxide powder according to the present invention is tin oxide or sb
Conventionally known materials such as tin oxide doped with p, etc., indium oxide or indium oxide doped with Sn, etc. can be used, but preferably, an aqueous solution of a tin compound or an indium compound is maintained under a pH condition of 8 to 12. By gradually hydrolyzing the compound during the night, a sol containing colloidal particles of metal oxide and/or hydrous oxide is generated, and then this sol is dried and fired to obtain a conductive fine powder. It is preferable to use a powder that has been pulverized to an average particle size of (L4 μm or less). This can be obtained by the invention of ``Method for producing conductive fine powder'' (Patent Application No. 50253/1989) previously filed by the present applicant. Furthermore, CRT+
For applications that require high transparency with low haze, such as front glass of display devices such as LOD and copy glass of copy machines, the average particle size of the conductive fine powder is 1101 to α1 μm.
It is best to use the powder after pulverizing it.

(If it is less than 101 μm, the film cannot be made porous, and if it is less than 11 μm,
If it exceeds this value, the haze value (hereinafter referred to as haze) of the resulting film increases, impairing the transparency of the substrate. However, the flat grain size is 1
Even if the particle size is 1 μm or less, if the particle size exceeds α1 μm, the haze of the coating will increase and the transparency of the substrate will decrease.
It is preferable that at least 0 mm be occupied by particles having a particle size of 111 μm or less.

The conductive fine particles may be pulverized before being mixed with other components such as zirconium oxyacid, or after being mixed with other components such as zirconium oxyacid. The pulverization method Fi can be carried out by a conventionally known pulverization method, and for example, equipment such as an attritor, a ball mill, and a three-roll mill can be used.

The non-precipitable 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, and 2.
Owt% (810, conversion) aqueous solution 25QOQOG
, when the sediment was centrifuged for 1 hour, the total 8% of the sediment in the aqueous solution was
10! 30 parts by weight, preferably 10 parts by weight or less. Preferably, non-sedimenting silica obtained by the invention of "Non-sedimenting silica composition for coating and method for producing the same" (Japanese Patent Application Laid-open No. 187835/1983) previously filed by the present applicant is used. The non-sedimentable silica obtained in this manner is inherently unstable and tends to form colloidal particles and gelatinize, but is stabilized by the growth inhibitor in the coating composition. Furthermore, this non-precipitating silica
Even when mixed with zirconium oxyacid, it does not gel, nor does zirconium oxyacid.

The growth inhibitor according to the present invention is one that does not gel or promote polymerization of silconium oxysalt and non-precipitated silica, preferably h,n-methyl-2-pyrrolidone, 11,N dimethyl Formamide, morpholine, ethylene clyful monoethyl ether, ethylene clyful monoethyl ether, ethylene glycol, etc., and their derivatives can be used singly or in combination of two or more types.

The diluent according to the present invention may be any diluent that does not cause gelation of the zirconium oxyacid salt and non-precipitating silica, such as methanol, ethanol, n-propanol, i-
7' Lovanol, n-butanol, 1-butanol, t
-Alcohols such as butanol, acidic esters such as methyl acetate and ethyl acetate, ethers such as diethyl ether, and acetone can be used alone or in combination of two or more.

Zr01・810!・The composition ratio of the conductive oxide powder, water, growth inhibitor, and diluent is as follows: The growth inhibitor is Z
r01 and 810! As a molar ratio to the total of 1≦(growth inhibitor) / (zro, +sto,)≦2
5 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 long-term storage will not be possible. If it exceeds 25, the coating composition will not be uniformly cured when it is applied and cured, resulting in poor durability of the coating. Second, water satisfies the condition α1≦H2O/Z r OH≦40 in terms of weight ratio with Zr01, and is 50 wt4 relative to the total weight of the coating liquid composition (hereinafter referred to as the total weight). The following is good. If α is less than 1, gelation of the zirconium oxyacid will occur, and if the weight ratio exceeds 40 or 50 wtn of the total weight, the growth inhibitor will lose its effectiveness and the coating composition will repel on the transparent substrate. be. Third, ZrO2 and Sin
The total weight of the powder and the conductive oxide powder is preferably 1 to 20 wt% of the total weight, and from the viewpoint of long-term storage of the coating solution, it is preferably α1 to 10%, 20 wt.
This is because if the amount is exceeded, the stability of the coating solution deteriorates and it easily gels. Fourth, the ratio of conductive oxide particles, zirconium oxyacid salt, and non-precipitating silica is preferably 1≦conductive oxide powder/(Zr01 +810)≦5 (weight ratio). If the value exceeds 5, the adhesion of the film will decrease because the conductivity of the film will be poor and the film will not become porous.

Fifth, the ratio of non-precipitated silica and zirconium oxyacid is α05≦8101/ZrO≦1 (weight ratio)
is good. If it is less than 0.005, 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 in such a manner that the transparent conductive coating composition of the present invention has a viscosity or a desired film thickness depending on the coating method.

The method for producing the transparent conductive coating liquid composition of the present invention is preferably, but not particularly limited to, a method in which zirconium oxyacid, non-precipitating silica, and conductive oxide powder are dispersed in water and a growth inhibitor in advance. A portion of the water may be dehydrated from the mixture, or a diluent may be added without dehydration, and a distillation method or an ultrapolar process can be used to dehydrate the water.

The transparent conductive coating liquid composition according to 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 tip method, a spray method, a roll foot method, a printing method, etc. If the film is coated and then dried, a film with good cracking resistance and mechanical strength can be obtained. However, for applications that require a coating film with even higher durability and mechanical strength, it is necessary to dry the film at a temperature of 300°C or higher and below the glass transition point of the base material. All you have to do is bake it.

The film obtained in this way has a total light transmittance (Tt) so
%, the haze (H) is 10 or less, so the transparency of the transparent substrate is not impaired, and the surface resistance is 104 to 109 Ω/cm, which has an excellent antistatic effect and prevents glare. It is not attacked by alkalis, is resistant to water and salt water, has excellent adhesion, and does not change its coating.

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. In addition, when coating on a colored base material, a film can be formed without changing the color tone of the base material.

The conductive glass or plastic obtained using the conductive coating liquid composition of the present invention can be applied to antistatic display panels, plastic glass, instrument display panels, transparent digitizers, ten lighting terminals, and the like.

Hereinafter, the present invention will be explained with reference to examples, but the present invention is not limited to these examples.

Example 1 Potassium stannate 316? and tartar stone 5a49, water 686
A raw material solution was prepared by dissolving it in t. The raw material liquid was added to 1000F water heated to 50°C and stirred over 12 hours together with nitric acid, and the system was maintained at pHia 5 for hydrolysis to obtain a sol solution. Colloidal particles were separated from this sol solution, washed to remove by-product salts, dried, and calcined in air at 350°C for 3 hours.
A fine powder (powder I) was obtained by firing at 50c for 2 hours. The obtained powder 12,000F and water were placed in a B o o yl sand mill and ground for 3 hours using a 1 to 2 mm diameter media. (
The average particle diameter of the particles in the pulverizing liquid 11 was LL 25 μm. ) 5 wt% sodium silicate as SiO snow (810 mol/Na, O = 3 mol/mol'l)
2000 f was passed through a hydrogen form ion exchange resin column at a space velocity of 7=5 while being maintained at 15° C. (non-precipitating silica liquid). 50f of this non-precipitating silica liquid, 50PK of the pulverized liquid 1, 20t of N-methyl-2-pyrrolidone and 25 wt% zirconium oxychloride aqueous solution 1r converted to Zr01, 10f and MeOH/EuO
H (weight ratio 1/1) 170P1 was added and thoroughly mixed to obtain a transparent conductive coating liquid composition.

Example 2 The non-sedimentable silica solution obtained in Example 1 was mixed with 502, the pulverized liquid (■) was mixed with 2002, ethylene glycol monomethyl ether (10f) and Zr0B (converted into 25 wtl), and the aqueous solution of zirconium oxychloride (4Of and MaOH/EtO)
1400f of I (weight ratio 1/1) was added and sufficiently dispersed to obtain a transparent conductive coating liquid composition.

Example 3 Powder obtained in Example 1! Of these, 10 are classified to 1 μm or less. and water 40f into a sand mill, 13~1
N-methyl-2 was crushed for 3 hours in a medium with a diameter of φ (the average particle size of the particles in the liquid of the crusher was 18 μm, and the amount of particles of 11 μm or less was more than 65 of the total particles). -Pyrrolidone 10f and Meal! / BuOH (weight ratio t/1
) A transparent conductive coating liquid composition was obtained under the same conditions as in Example 1 except that 3802 was used.

Example 4 Indium nitrate 79.9 f to water 686? A solution of potassium stannate (12.7 F) dissolved in 10 wtl potassium hydroxide aqueous solution was prepared. The above-mentioned indium nitrate solution and potassium stannate solution are added over 2 hours to 1000 f water heated to 50°C and stirred, and the pH in the system is maintained at 11 to perform hydrolysis and form a sol solution. I got it.

The colloidal particles are separated from this sol solution, washed to remove by-product salts, dried, and calcined in the air at 350°C for 3 hours, and further calcined in the air at 650°C for 2 hours to form a fine powder.
Powder ■) was obtained.

A transparent coating liquid composition was obtained under the same conditions as in Example 1, except that 10 f of the obtained powder (1) and 40 tons of water were used.

Example 5 50t of non-sedimentable silica liquid obtained in Example ffIJ 1
and 220 f of the pulverizing liquid, 110 t of N-methyl-2-pyrrolidone, and 25 Wt in terms of ZrOH.
(weight ratio 1/1) 345 ft- was added and sufficiently dispersed to obtain a transparent conductive coating liquid composition.

Example 6 The non-precipitating silica solution obtained in Example 1 was added to 502, and the grinding solution was added to 1002! ! , la dimethylformamide 15
After uniformly mixing 0t and 25wt96 zirconium oxynitrate aqueous solution 30F in terms of ZrOH, the water was heated to 80℃ under reduced pressure using a rotary evaporator to
52 was distilled out.

This liquid was cooled and further MeOH/BuOIII (weight ratio 1/1) 405F was added and sufficiently dispersed to obtain a transparent conductive coating liquid composition.

Comparative Example 1 20 ports of the non-sedimented silica liquid obtained in Example 1, 125 ports of the pulverizing liquid I, and 50 ports of N-methyl-2-pyrrolidone.
After uniformly mixing 25 wtJ zirconium oxychloride aqueous solution 102 in terms of ZrO2, the mixture was heated to 80°C under reduced pressure in a rotary evaporator and water was heated to 1210°C.
I let it drain out. This liquid is cooled and further MeOH/EuO
H (weight ratio 1/1) 10752 was added and sufficiently dispersed to obtain a transparent conductive coating liquid composition.

Comparative Example 2 The non-precipitating silica liquid obtained in Example 1 was crushed with 1002! 251, 40t of N-methyl-2-pyrrolidone and 2s wtl aqueous zirconium oxychloride solution in terms of 2Of and Mean/Eu0)! (1/1 weight ratio) was added and sufficiently dispersed to obtain a transparent conductive coating liquid composition.

Comparative Example 3 The non-sedimented silica obtained in Example 1 was added to 100r and the grinding liquid 11 was added to 550f, and 1l-1f & -2-pyrrolidone aa
After homogeneously mixing 20 f of zirconium oxynitrate aqueous solution (25 wt in terms of t and ZrO2), heat the water to 80 C while reducing the pressure using a rotary evaporator to reduce the water to 25 wtl.
I let it drain out.

This liquid was cooled and further mixed with MsOH/EuOH (weight ratio 1
/1) 1340f was added and sufficiently dispersed to obtain a transparent conductive coating liquid composition.

Comparative Example 4 N-methyl-2-pyrrolidone 6 was added to 5002 of the non-precipitating silica solution obtained in Example 1 and 500f of the grinding solution
After uniformly mixing 100f'i of 25wt1L zirconium oxynitrate aqueous solution in terms of Zr01 and Zr01, rotary
Heat the water to 80℃ while reducing the pressure with an evaporator and add 9.
00? When distilled, it turned into a gel.

Comparative Example 5 The non-precipitating silica liquid obtained in Example 1 was added to 1002, the pulverized liquid I was added to 100f, and N-methyl-2-pyrrolidone was added to 25f.
1100 f of a 5 wt* zirconium oxychloride aqueous solution and 75 F of MeOH/BuOH (weight ratio 1/1) were added and sufficiently dispersed to obtain a transparent conductive coating liquid composition.

Table 1 shows the liquid compositions and composition ratios of Examples and Comparative Examples.

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 composition obtained in Example fI16 was applied to an acrylic plate using a spinner at 2000 r.
, p, m. The glass plate was dried at 110°C for 10 minutes and then fired at 300°C for 30 minutes, and the acrylic plate was dried at 110°C for 30 minutes.
A film was obtained by drying at ℃ for 30 minutes. The nine films obtained were evaluated as follows. The results are shown in Tables 2 and 3.

■Transparency: Total light transmittance (TI, ) 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 J Engineering 817105-81.

(2) Adhesion: A part of a commercially available 12-width cellophane tape was attached to the film, and while keeping the residue at right angles to the film, it was instantly peeled off and the presence or absence of the film on the glass was visually observed.

■Hardness 1i: Measured by the pencil hardness test of Tl8DO202-71.

0 Surface resistance: Measured with an electrode cell (manufactured by YHP).

■Durability 2 After soaking in the following four types of liquids, adhesion (same as ■) was evaluated, and glossiness and surface resistance (same as ■ and ■) before and after the test were compared.

1) 15wt% ammonia water at room temperature 120 hours.

2) 10 wt96 NaC! into an aqueous solution at room temperature
20 hours.

3) Submerge in boiling water for 30 minutes.

4) Sowts acetic acid aqueous solution at room temperature. 120 hours.

〔Effect of the invention〕

The coating liquid composition of the present invention is a coating liquid composition in which a zirconium oxyacid salt and conductive oxide particles are uniformly dispersed in water, a stabilizer, and a diluent. A conductive film with excellent scratch resistance, durability, and no glare can be formed at low temperatures without compromising transparency. In addition, the pot life (usable period) of the coating liquid composition of the present invention
Stored at room temperature in the dark for 3 months or more.

In addition, for applications where surface smoothness is required, or when it is desired to reduce the surface friction coefficient, resins such as polyester, acrylic, silicone, polypropynon, polyethylene, volistine, epoxy, etc. may be used on the coating of the present invention. A transparent protective film of inorganic material such as silica may be provided.

Claims (1)

[Claims] (1) A transparent product characterized by uniformly dispersing zirconium oxyacid, non-precipitating silica, and conductive oxide powder in a dispersion medium consisting of water, a growth inhibitor, and a diluent. Conductive coating liquid composition. (2) As a growth inhibitor, one 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 liquid composition according to claim 1, which is used in the present invention. (3) Add an aqueous solution of a tin compound or an indium compound to 8 to
A sol containing colloidal particles of metal oxides and/or hydrous oxides is produced by gradually hydrolyzing the compounds in the solution while maintaining the solution at a pH of 12, and then this sol is dried and calcined. The transparent conductive coating liquid composition according to claim 1 or 2, characterized in that a fine powder obtained by pulverizing the product obtained by pulverizing the product is used as the conductive oxide powder. (4) Convert zirconium oxyacid to ZrO_2, convert non-precipitated silica to SiO_2, and set the composition ratio of conductive oxide powder, moisture, growth inhibitor, and diluent to 1≦(growth inhibitor )/(ZrO_2+SiO_2)≦2
5 (mol ratio) 0.1≦H_2O/ZrO_2≦40 (weight ratio) H_2O/(total weight of coating liquid composition)≦0.5 (weight ratio) 0.001≦(ZrO_2+SiO_2+conductive oxide powder)/ (Total weight of coating liquid composition)≦0.2 (weight ratio) 1≦(conductive oxide powder)/(ZrO_2+SiO_2
)≦5 (weight ratio) 0.05≦SiO_2/ZrO_2≦1 (weight ratio) Composition. (5) A coating solution in which zirconium oxysalt, non-precipitating silica, and conductive oxide powder are uniformly dispersed in a dispersion medium consisting of water, a growth inhibitor, and a diluent is applied to the substrate and then cured. A base material with a transparent conductive coating.