JPH03234771A - Inorganic conductive coating composition and manufacture of conductive coating - Google Patents

Abstract

PURPOSE:To improve the conductivity, transparency, solvent resistance and marring resistance by mixing a specific reaction product, a siloxane polymer and a solvent. CONSTITUTION:An at least equimolar amount of a lower alcohol is dropped into a mixture of SnCl4 and SnCl2 or a mixture of 1mol of the mixture and 0.001-1.0mol of a mixture of SbCl3 and SbCl5 to react, thereby producing a reaction product (A). 1mol of tetraalkoxysilane and 0.01-1mol of ZrCl4 are subjected to hydrolytic condensation in the presence of 0.01-8mol of water to produce a siloxane polymer (B). Then, 100 pts.wt. (solid component) component (A) is mixed with 5-2000 pts.wt. (solid component) component (B) and a solvent (e.g. ethyl alcohol) to obtain an inorganic conductive coating composition having a solid content of 0.01wt.% or more. The composition is applied to the surface of a base material, heated at 120 deg.C or above for 10min or more to cure, thereby obtaining a conductive coating having a film thickness of 40mum or more.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an inorganic conductive coating composition, and more specifically, it is suitable for forming a highly transparent conductive film on a substrate surface such as glass or ceramic. The present invention relates to an inorganic conductive coating composition and a method for producing a conductive coating film using the same.

(Prior Art) In recent years, conductive coating films have been formed on the glass surfaces of television cathode ray tubes and displays of various office automation equipment for the purpose of preventing static electricity.

This method involves applying organic substances such as alcohol polymers, higher alcohols, and surfactants, but this method has poor solvent resistance and scratch resistance, so the antistatic effect has a short lifespan and is not practical. Not. As another method, attempts have been made to form antistatic films using inorganic materials. For example, in Japanese Patent Application Laid-open No. 62-187188,
After hydrolyzing a hydrolyzable tin compound or an antimony-doped tin compound to obtain fine particles, water is removed.

A method of dispersing in ethanol and firing is disclosed. However, this method has the drawbacks of limited transparency because fine particles are dispersed, and poor scratch resistance because it does not contain the traditional binder resin. Also, JP-A-6
2-252481 discloses a method using conductive tin oxide powder and a binder resin, but this method also uses fine powder, resulting in poor transparency, and the binder resin is organic. Since it is a polymer, it has the disadvantage of poor solvent resistance and scratch resistance.

In such conventional methods, tin oxide or antimony-doped tin oxide powder, which serves as a conductive component, is mechanically or chemically dissolved to form fine particles and die, making it difficult to convert them into primary particles. be.

Furthermore, even if it can be made into primary particles, there is a limit to its transparency and it is difficult to prevent reagglomeration.

In addition, since an organic resin is used as a binder, it has poor scratch resistance and solvent resistance.In addition, as an inorganic binder, monomers such as tetraethoxysilane, ethyl silicate 40 (trade name manufactured by Colcoat Co., Ltd., siloxane oligomer, Even when oligomers such as those having a weight average molecular weight of 1000 or siloxane polymers having a molecular weight of 1000 or more are used, the scratch resistance cannot be said to be sufficient.

(Problems to be Solved by the Invention) An object of the present invention is to solve the problems of the prior art described above and to provide an inorganic conductive coating composition that has excellent conductivity, transparency, solvent resistance, and scratch resistance. It is in.

(Means for Solving the Problems) The present invention provides (A) tin chloride! or a reaction product obtained by reacting a mixture of tin chloride and antimony chloride with a lower alcohol in an amount equal to or more than the same mole relative to the tin chloride case or the mixture, (B) hydrolytic condensation of tetraalkoxysilane and zirconium chloride. The siloxane-based polymer button obtained by
) An inorganic conductive coating composition comprising a solvent.

The reactant used in the present invention is obtained by reacting tin chloride or a mixture of tin chloride and antimony chloride with a lower alcohol in an amount equal to or more than the same mole relative to the tin chloride case or the mixture.

As the lower alcohol, methyl alcohol, ethyl alcohol, phthyl alcohol, isopropyl alcohol, etc. are used. Two or more of these may be used in combination. Ethyl alcohol is preferably used from the viewpoint of reactivity and smoothness of the coating film.

As tin chloride, tetravalent tin chloride (5nC14) or a mixture of tetravalent tin chloride and divalent tin chloride (SnC/z) is used, but from the viewpoint of conductivity and scratch resistance, Tetravalent tin chloride is a good choice. In addition, as antimony chloride, trivalent antimony chloride (5bC1s) button and 5
Antimony (8bC2s) can be used alone or in combination.

In the present invention, it is preferable to use a mixture of tin chloride and antimony chloride from the viewpoint of the electrical conductivity of the coating film.

The proportion of tin chloride and antimony chloride to be used is preferably in the range of 0.001 mol to 1.0 mol of antimony chloride per 1 mol of tin chloride from the viewpoint of the conductivity and transparency of the coating film.

The bottom of the reactant container is generally prepared by dropping excess ethanol into a mixture of tin chloride and antimony chloride to remove generated hydrogen chloride.

The siloxane polymer CB) used in the present invention is a polymer obtained by hydrolyzing and condensing tetraalkoxysilane and zirconium chloride. In this hydrolytic condensation, tetraalkoxysilane and zirconium chloride are dissolved in a solvent with good compatibility such as ethylalnyl, water is added thereto in a range of 0.01 to 8 moles per mole of tetraalkoxysilane, and the mixture is heated. It is done by stirring. The heating temperature is set to a temperature that does not exceed the boiling point of the solvent. As the tetraalkoxysilane, one having an alkoxide having 1 to 5 carbon atoms is used. Zirconium chloride is blended in an amount of 0.01 to 1 mole per mole of tetraalkoxysilane. 0
．． If it is less than 0.01 mole, scratch resistance will be insufficient, and if it exceeds 1 mole, transparency will be poor.

From the viewpoint of scratch resistance and conductivity, the blending ratio of the components (A) and (B) is such that the solid content of the Bl component is 5 to 5 parts by weight per 100 parts by weight of the solid content of the component (A). It is light and heavy to use within the range of 2000 parts by weight.

Solvents (C) used in the present invention include alcoholic solvents such as methyl alcohol, ethyl alcohol, isopropyl alcohol, butyl alcohol, diacetone alcohol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, calpitol, ethylene glycol, diethylene glycol, acetone, methyl ethyl ketone,
Ketone solvents such as methyl isobutyl ketone, ethyl acetate.

Examples include ester solvents such as butyl acetate, various halogen solvents, and these can be used alone or in combination. Among these, ethyl alcohol is preferred.

The solid content of the inorganic conductive coating composition of the present invention is preferably 0.01% by weight or more from the viewpoint of conductivity. It is blended so that the weight coefficient is 0.01 or more.

The inorganic conductive coating composition of the present invention is a spin code.

It is applied onto a substrate surface such as glass or ceramic using a general coating method such as spray coating, roll coating, or dip coating, and is cured for 10 minutes or more at a temperature of 120°C or higher to form a conductive coating. . The film thickness at this time is preferably 40 μm or less from the viewpoint of crack resistance.

(Example) The present invention will be explained in detail below using nine examples.

Parts in the examples mean parts by weight.

(1) Synthesis of conductive liquid A 5nC1425g and 5b (J's 39 to 500-
The mixture was placed in three flasks and stirred. After stirring at room temperature for 5 minutes, 300 g of ethyl alcohol was added dropwise over about 1 hour, and hydrogen chloride was removed while purging with nitrogen.

After the dropwise addition was completed, conductive liquid A was obtained by stirring for about 30 minutes.

(2) Synthesis of Siloxane Polymer Solution B Three 109-buttons of tetraethoxysilane and 109-buttons of ethyl alcohol were placed in a flask and stirred.

A solution prepared by dissolving 0.4 g of zirconium chloride in ethyl alcohol 109 was added dropwise to this solution over a period of about 10 minutes with stirring. Next, a solution prepared by dissolving 3.5 g of water in 20 g of ethyl alcohol was added dropwise over about 10 minutes.

Thereafter, the temperature was raised to 70° C. and stirred for 1 hour to obtain a siloxane polymer solution B having a weight average molecular weight of 7,000. The weight average molecular weight was determined by high performance liquid chromatography (Pump: C-6000, RI detector: C-3300, manufactured by Hitachi, Ltd.).
Data processor: Measured using a low-molecular column (from D-2520) (polystyrene equivalent).

Conductive liquid A289. obtained above. Paint A was obtained by mixing and stirring a siloxane polymer solution Bio, sg> and 60 g of ethyl alcohol.

Comparative Example 1 Antimony-doped tin oxide powder T-1 (trade name manufactured by Mitsubishi Metals Co., Ltd.) 309 and ethyl alcohol 3009 were charged into an attritor filled with 300 mg of glass beads having a diameter of 1.0 mm, and mixed for about 10 hours. A T-1 dispersion was obtained.

15 g of this T-1 dispersion, 11.59 g of the siloxane polymer solution B of Example 1, and 73.59 g of ethyl alcohol.
Paint B was obtained by mixing and stirring.

Comparative Example 2 Conductive liquid A289 of Example 1. Paint C was obtained by mixing and stirring 1.5 g of tetraethoxysilane and 70.59 g of ethyl alcohol.

Comparative Example 3 28 g of conductive liquid A, ethyl silicate 40 (trade name manufactured by Colcoat, siloxane oligomer, weight average molecular weight 10)
00) 39 button and ethyl alcohol 699 were mixed and stirred to obtain a paint.

<Test example> The obtained paints A-D were applied on a glass plate at 30 Orpm.
Spin coded for 0 seconds and then cured at 160° C. for 30 minutes. 1 surface resistance, 550 nm using the obtained test piece
The transmittance, pencil hardness and ethyl alcohol resistance were evaluated. The results are shown in Table 1.

Table 1 *x Measured using a Yokogawa Hewlett resistance meter manufactured by Tsukard.

*2 Absorbance was measured at 550 nm using a UV spectrophotometer.

*3 Conducted according to JIS C3003.

*4 Soaked in ethyl alcohol for 24 hours at room temperature.

Changes in appearance were visually observed.

Table 1 shows that the inorganic conductive coating composition of the present invention has low surface resistance, high transparency, and high pencil hardness, so it has excellent scratch resistance and solvent resistance.

(Effects of the Invention) The inorganic conductive coating composition of the present invention has excellent transparency because the conductive component is not a dispersion of metal oxide particles, and is scratch resistant because it uses a zircon-based siloxane polymer as the binder. A conductive coating film with excellent properties and solvent resistance can be obtained.

Claims (1)

[Claims] 1. (A) A reaction product obtained by reacting tin chloride or a mixture of tin chloride and antimony chloride with a lower alcohol in an amount equal to or more than the same molar amount as the tin chloride or the mixture; (B) An inorganic conductive coating composition comprising a siloxane-based polymer obtained by hydrolyzing and condensing tetraalkoxysilane and zirconium chloride, and (C) a solvent. 2. 0.0 antimony chloride for 1 mole of tin chloride
The inorganic conductive coating composition according to claim 1, wherein the amount is 01 to 1.0 mol. 3. The inorganic conductive coating composition according to claim 1, wherein the solid content of component (B) is 5 to 2000 parts by weight relative to 100 parts by weight of component (A). 4. A method for producing a conductive coating film, which comprises coating the inorganic conductive coating composition according to claim 1 on a substrate surface and curing the composition.