JPS624328B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a conductive alkali metal titanate having an excellent reinforcing effect on plastics and the like.

Non-metal powders with metal coatings are not only advantageous in terms of resource conservation compared to powders obtained by pulverizing metal lumps, but depending on the material of the core, they are less dispersible in plastics. , it has excellent stability after dispersion, reinforcing effect, etc.

The present inventor has focused on the excellent properties of alkali metal titanate as a material for the core, and has already found that titanate crystals can be easily coated with metal by electroless plating. We have confirmed that it can be used as a titanate and have filed an application. However, the electroless plating method is not only used when coating reduced titanate crystals with metal to make it conductive, but also when making the well-known crystalline alkali metal titanate salt conductive. There was a problem in that the crystalline alkali metal titanate salt had to be activated first.

The present inventor has developed the present invention as a result of intensive research based on the idea of depositing a compound of a conductive element on an alkali metal titanate, instead of directly forming a metal coating on an alkali metal titanate. Reached.

That is, the present invention provides an aqueous dispersion of an alkali metal titanate, (a) a solution of one or more compounds selected from the group of compounds of tin, indium, antimony, copper, and nickel, and (b) hydroxide. An aqueous solution of an alkali or an alkali halide, characterized in that both solutions are added at the same time, and the water-insoluble component produced by the reaction of the (a) solution and (b) solution is deposited on the surface of the alkali metal titanate salt. The present invention relates to a method for producing a conductive alkali metal titanate.

Here, the alkali metal titanate is
A well-known crystalline substance represented by the general formula M ₂ O・nTiO ₂・mH ₂ O (wherein M is an alkali metal, n is an integer from 2 to 12, and m is 0 or a positive real number of 4 or less). Refers to an alkali metal titanate salt.

Among the alkali metal titanate salts, especially the general formula
Potassium titanate, represented by K ₂ O・n′TiO ₂・mH ₂ O (in the formula, n′ is an integer from 2 to 8, and m means the same as above), has excellent heat resistance and is relatively Since its production has been established, it is advantageous as a material for obtaining the object of the present invention.

In addition, potassium titanate is produced not only in powder form but also in fibrous form, and this fibrous potassium titanate is particularly desirable as a material for the present invention because it has excellent reinforcing properties as a filler. be.

Examples of compounds of tin, indium, antimony, copper, or nickel (hereinafter referred to as conductive elements) include those that exhibit acidity when made into an aqueous solution, such as halogenated salts, sulfates, and oxides of conductive elements. It will be done.

Preferred examples of conductive element compounds include chlorides such as stannous chloride, stannic chloride, indium chloride, antimony chloride, cupric chloride, nickel chloride, and nickel chloride. Other examples include cuprous sulfate, cupric sulfate, antimony oxide, and the like.

Compounds of these conductive elements are important for occupational safety,
From the perspective of saving resources, it is desirable to use it as an aqueous solution, but alcohols with 3 or less carbon atoms, acetone, ethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol, polyoxyethylene, oxypropylene block copolymers, dioxane , water-soluble organic solvents such as glycerin, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate are also used alone,
They can also be used together.

Examples of the alkali hydroxide and alkali halide include those that exhibit alkalinity when made into an aqueous solution, such as lithium hydroxide, sodium hydroxide, potassium hydroxide, lithium iodide, sodium iodide, and potassium iodide.

When preparing an aqueous dispersion of alkali metal titanate, the concentration is 0.01 to 50% by weight, preferably
The content should be 0.1 to 20% by weight.

A solution of a compound of a conductive element [liquid (a)] and an aqueous solution of an alkali hydroxide or alkali halide [(b)] to be added to an aqueous dispersion of an alkali metal titanate.
The concentration of the liquid] is not particularly limited, but if the concentration is too low, the amount of liquid will increase and it will be inconvenient to handle.
In addition, since the size of the equipment increases, the temperature must be adjusted to below the solubility. Conductive alkali metal titanates can be obtained even if a liquid containing a compound of a conductive element or alkali hydroxide or alkali halide is added above the solubility, but the increase in the amount added is This is unsuitable because it does not improve the conductivity of the target object and on the contrary prevents the homogeneous deposition of water-insoluble components into the alkali metal titanate.

In the aqueous dispersion of alkali metal titanate, (a) liquid, (b)
When adding the liquid, while stirring the aqueous dispersion of alkali metal titanate, and keeping the pH value at 6 to 9 so as not to shift too much to the strongly alkaline or strongly acidic range, It is preferable to do it gradually.

(a) The total amount of liquid added should be within the range of approximately 300 parts by weight or less per 100 parts by weight of the alkali metal titanate in terms of the weight of the conductive element to obtain the desired conductive object. Bye. In reality, even if more than 300 parts by weight of liquid (a) is added, a water-insoluble component can be produced by adding liquid (b) correspondingly. This is because the components often adhere so weakly to the surface of the alkali metal titanate that they can be removed by washing with water. Although it varies to some extent depending on the specific combination of liquids (a) and (b), if it is within the above 300 parts by weight, the water-insoluble component produced by the reaction of liquid (a) and liquid (b) Not only can it firmly adhere to the surface of the alkali metal titanate salt, but also the waste liquid (
This is extremely advantageous since no conductive element compounds remain in the liquid.

The total amount of liquid (b) to be added is determined by
If it is a liquid and the addition is terminated at pH 7.0±0.5, it can be naturally determined from the total amount of liquid (a) added.

The reaction between liquid (a) and liquid (b) may be allowed to proceed at room temperature.

After the above operations, the object of the present invention is obtained by filtration, but in order to further improve the conductivity of the object, it is desirable to further perform firing or reduction treatment. In this firing treatment, the filtered material is fired at, for example, 600 to 800°C for 1 to 5 hours. Also,
In the reduction treatment, the filtrate is directly reduced with a reducing gas such as hydrogen gas or carbon monoxide, or the filtered material mixed with carbon powder etc. is placed in a non-oxidizing gas atmosphere, for example,
It may be heated to 200 to 1000°C in an atmosphere containing 90% by weight or more of nitrogen gas, helium gas, or carbon dioxide gas.

Note that the present invention does not specifically exclude the addition of commonly thought of additives such as surfactants, antifoaming agents, and doping agents to increase conductivity in order to stabilize the system. .

As is clear from the above description, the present invention does not require any special equipment to carry out, and therefore can be easily industrialized. In particular, convert the total amount of liquid (a) added into the weight of the conductive element, and calculate the amount of alkali titanate 100
When carrying out the present invention appropriately within a range of approximately 30 parts by weight or less, the conductive element is firmly adhered to the surface of the alkali metal titanate as a water-insoluble component with almost no loss. Therefore, there is no problem of waste liquid treatment, making it extremely useful for industry.

Example 1 Fibrous potassium titanate (TISMO-L) 5
g was dispersed in 500 c.c. of water and stirred for 5 minutes using a stirrer. Next, while continuing to stir this dispersion, 7.5 g of stannous chloride (SnCl ₂ 2H ₂ O) was added to ethanol.
A solution dissolved in 50 c.c. is placed in a dispersion liquid,
Neutralization reaction was carried out by simultaneously dropping a 5W% potassium hydroxide solution, which was added dropwise over about 20 minutes while maintaining the pH value at 6 to 7. Finally, the pH value of the dispersion was adjusted to 7, and stirring was continued for 10 minutes. After that, another
It was washed and dried at 100°C for one day and night. Then 800℃
It was baked for 4 hours. The yield after baking was 9.9g. The result of measuring the resistance value of this powder is 3×
A value of 10 ⁴ Ω·cm was obtained.

2 Using a solution of 15 g of stannous chloride (SnCl ₂ 2H ₂ O) dissolved in 100 c.c. of ethanol solution, Example 1
A similar operation was performed. Yield after baking is 14.8g
It was hot. Results of measuring the resistance value of this powder 2
A value of ×10 ³ Ω·cm was obtained.

3 Add 7.5 g of stannous chloride (SnCl ₂ 2H ₂ O) and 0.4 g of antimony chloride (SbCl ₃ ) to 100 c.c. of ethanol.
The same operation as in Example 1 was carried out using a solution dissolved in . The yield after firing was 9.9 g, and the color was slightly bluish. As a result of measuring the resistance value of this powder, a value of 1.5×10 ⁴ Ω·cm was obtained.

4 The same operation as in Example 1 was carried out using a solution in which 8 g of indium chloride (InCl ₃ ) was dissolved in 50 cc of water. The yield after baking was 9.9g. The resistance value of this powder was measured and was 1.2×10 ⁴ Ω. cm
obtained the value of

5 A solution of 8 g of indium chloride (InCl ₃ ) dissolved in 50 c.c. of water and stannous chloride (SnCl ₂ 2H ₂ O)
Using a solution of 0.4 g dissolved in 10 c.c. of ethanol, operate while paying attention to the amount of the tin chloride solution added so that the dropwise addition to the dispersion of the indium chloride solution and the stannous chloride solution is uniform. did. Other operations such as maintaining the pH value of the dispersion using 5W% potassium hydroxide were carried out in the same manner as in Example 1. The yield after firing is
It was 9.9g. As a result of measuring the resistance value of this powder, a value of 2.6×10 ² Ω·cm was obtained.

6 TISMO-L5g and 6W% sulfite 36g with water
It was dispersed in a solution weighing 500 g and stirred for 5 minutes using a stirrer. Next, while continuing to stir this dispersion, a solution of 6.6 g of copper sulfate (CuSO ₄ .5H ₂ O) dissolved in 100 c.c. of water and 8.7 g of potassium iodide (KI) were added to the water.
A solution dissolved in 100 c.c. was simultaneously added dropwise in equal amounts over about 20 minutes. Thereafter, stirring was continued until the color of this dispersion liquid became pale yellow. Next, it was washed separately and dried at 50°C for one day and night. Yield: 9.8g
It was pale yellow in color. As a result of measuring the resistance value, a value of 1.8×10 ⁵ Ω·cm was obtained.

7 Same as Example 6 using a solution of 13.2 g of copper sulfate (CuSO ₄ 5H ₂ O) dissolved in 150 c.c. of water and a solution of 17.4 g of potassium iodide (KI) dissolved in 150 c.c. of water. I performed the following operations. The yield was 14.5 g, with a pale orange-yellow color. Resistance measurement results
A value of 8.7×10 ² Ω·cm was obtained.

8 5 g of TISMO-L was dispersed in 50 c.c. of water and stirred for 5 minutes using a stirrer. Next, while continuing to stir this dispersion, 13.4 g of copper chloride (CuCl ₂ 2 H ₂ O) was added to 100 ml of water.
cc solution was simultaneously added dropwise to the dispersion liquid to cause a neutralization reaction, and the solution was added dropwise over about 20 minutes while maintaining the pH value at 6 to 7. Finally, the pH value of the dispersion was adjusted to 7, and stirring was continued for 10 minutes. Then wash separately 100
After drying at ℃ for 1 day, a yellow-green powder was obtained. Next, this powder was calcined at 400°C for 1 hour to obtain a black-brown powder. The yield was 11.2g. This powder was packed in a quartz tube and hydrogen-reduced at 350°C for 30 minutes while passing H ₂ gas through it. The obtained powder had a copper color. As a result of measuring the resistance value, a value of 1.5×10 ³ Ω·cm was obtained.

9 The same operation as in Example 8 was carried out using a solution in which 26.8 g of copper chloride (CuCl ₂ .2H ₂ O) was dissolved in 150 cc of water. Yield after baking at 400℃ for 1 hour is 17.4
It was hot at g. A part of this powder was reduced with hydrogen in the same manner as in Example 8, and a resistance value of 1.7×10 ² Ω·cm was obtained.

10 Add 20.2g of nickel chloride (NiCl _{2.6H 2} O) to water.
The same operation as in Example 8 was carried out using a solution dissolved in 100 c.c. The yield after firing was 11.2 g, which had a slightly gray-green color. Next, hydrogen reduction was performed in the same manner as in Example 8, and a resistance value of 1.9×10 ³ Ω·cm was obtained.

Claims (1)

[Scope of Claims] 1. In an aqueous dispersion of an alkali metal titanate, (a) a solution of one or more compounds selected from the group of compounds of tin, indium, antimony, copper, and nickel; (b) water; An aqueous solution of an alkali oxide or an alkali halide is added at the same time, and the water-insoluble component produced by the reaction between the (a) solution and (b) solution is deposited on the surface of the alkali metal titanate salt. do,
Method for producing conductive alkali metal titanate.