JPS62216105A - Conductive mica and manufacture of the same - 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 relates to a conductive mica that has an excellent reinforcing effect on plastics and can be used for conductive composite materials, paints, inks, etc., and a method for producing the same.

(Conventional FuvFI) In recent years, with the significant development of the NIC industry, there has been a desire for the development of conductive materials as related materials. Although mica powder has a layered VT structure and has excellent heat resistance, it is electrically insulating, and it has been desired to modify it into a conductive reinforcing material, but there is no suitable method, and electroless At present, attempts are being made to make the material conductive by plating.

(Problems to be Solved by the Invention) An object of the present invention is to provide a white or pale colored conductive mica with excellent heat resistance and an advantageous method for producing the same.

(Means for Solving the Problems) The present invention provides the surface of a mica powder containing 0.1 to 20i11% by weight of one or more of a mixture of two or more of the metal group consisting of antimony, indium, and niobium, and the remaining The present invention relates to a conductive mica coated with a coating II layer consisting essentially of tin oxide with a total weight of 5 to 70 weight of 11 rlL, and a method for producing the same.

In the present invention, the mica substance has the general formula X. ,,~1. .

Y, ~, 240. . (A) Represented by 2. In the formula, X is Na+, K+, Cn", Ba", Rb", Sr"
; Y is Mg", Fe", Ni", Mn", AI
"+Fe", Li", Z as S i", Ge",
A I''1゜)'e2+, 133+, etc. are exemplified,
A represents fluorine or a hydroxyl group. Specific examples include natural minerals such as muscovite, soda mica, phlogopite, biotite, and lepidolite, and synthetic micas such as fluorine phlogopite, 7-tetrasilicon mica, and duolite. In addition, in the present invention, the above-mentioned millet grains are used as one kind or a mixture of two or more kinds, and furthermore, ammonia, organic amines, and other arbitrary components are adsorbed or introduced into the mica grains. good.

When muscovite or phlogopite-based mica is used as the mica in the present invention, a white conductive mica is obtained, which is excellent in post-usability.

In the present invention, cloud [U-quality powder may be of any particle size, but if it is too fine, the reinforcing properties will be poor, and if it is too large, the non-uniformity will increase when it is made into a composite material, and the surface will become rough. Since harmful effects may occur, a particle size of approximately 2 μm 0 to 30 mm is preferable, and a particle size of approximately 10 μIll to 10+ua is particularly preferable.

The conductive mica of the present invention is obtained by adding a tin compound and a metal compound (hereinafter simply referred to as metal compound) consisting of one or more metals from the metal group consisting of antimony, indium, and niobium to an aqueous dispersion of mica powder. 1) Obtained by adding each in a solution state, then separating the insoluble matter, and heat-treating this.

The tin compounds and metal compounds of the present invention may be those that are soluble in water or water-soluble organic solvents, such as acidic or alkaline water-soluble compounds such as halogen mares, oxides, metal alcoholades, and metal compounds. Examples include those soluble in water-soluble organic solvents such as acetyl 7cetonate.

Specifically, S nC12, S IIC14, 8bC13
゜5ljCI5. InCl, NbCl□ Water-soluble compounds such as sodium stannate, tin oxide, antimony oxide, niobium oxide, and water-soluble organic solvents such as methylate, methylate, propionate, butyrate, and acetylacetonate of tin, antimony, indium, and niobium. Examples include soluble compounds.

These tin compounds and metal compounds are
rA Kasa's point of view, it is desirable to use it as an aqueous solution from α, but water-soluble organic solvents, such as alcohols with 3 or less carbon atoms, acetone, ethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol, polyoxyethylene glycol, etc. propylene block copolymer, nooxane, glycerin, methyl cellosolve, methyl cellosolve, butyl cellosolve, ethyl cellosolve acetate, ethyl cellosolve acetate,
Butyl cellosolve acetate, noacetone alcohol,
Examples include one or more mixed solvents such as 7-cetyl-7-cetonate, and aqueous solutions thereof.

In the present invention, either a solution in which the tin compound and the metal compound are dissolved separately, or a solution in which the tin compound and the metal compound are dissolved simultaneously can be used.

When preparing an aqueous dispersion of micaceous powder, the apparent concentration is about 0.01 to 50% (weight %, the same applies hereinafter), preferably about 0.1 to 30%.

- The concentration of the tin compound and metal compound solution added to the aqueous dispersion of micaceous powder can be freely selected, but if the concentration is too low, the amount of liquid increases, making it inconvenient to handle and reducing productivity. On the other hand, if a solution containing tin compounds and metal compounds with a higher solubility is used, the hydrolyzate of these compounds will be deposited non-uniformly on the micaceous powder, and the desired conductive cloud will be formed by the conductivity of the powder. There is a risk that variations may occur.

In the present invention, the coating dust on the surface of the micaceous powder contains 0.1 to 20% of one or a mixture of two or more of the genus consisting of antimony, indium, and niobium, and the remainder is substantially oxidized. Composed of tin.

The content of Sly, In, and Nb in the M layer is 0.
If it is less than 1%, the doping effect is poor and high conductivity cannot be expected.

There is no particular upper limit, but if it exceeds 20%, it becomes a gray or bluish chromatic color, which tends to reduce the white skin, reducing its utility as a white conductive material. In addition, it generally tends to be expensive (industrial applicability decreases).

Regarding the amount of coating on the surface of the mica powder, if the coating amount is too small, the wave crests will not be uniform and conductivity will not be developed, or the conductivity will be low.On the other hand, if the coating amount is too large, the conductive coating will not be effectively effective. Since a single layer is sufficient, a single layer of conductivity cannot be expected, and furthermore, particulate matter will adhere, reducing the homogeneity and easily reducing the shape characteristics of mica-based rice. Therefore, the total proportion of coating waste should be approximately 5. ~
A range of 70% is preferred.

A tin compound and metal compound solution (
Hereinafter, it is abbreviated as "both metal compound solution"). 1
need to be adjusted.

The first method of hydrolysis is to use organic compounds such as alcolade and acetylacetonate as the tin compound and metal compound, and to add these dissolved in a water-soluble organic solvent to an aqueous dispersion of micaceous powder. As a result, the tin compound and the metal compound are hydrolyzed and deposited on the surface of the micaceous powder. Since these hydrolysis reactions are accelerated under heating or in the presence of an alkaline substance, it is preferable to heat the aqueous mica dispersion to a temperature of 50°C or higher and lower than the boiling point to carry out the reaction. As these pH feather W agents, alkali metal hydroxides, carbonates, nitrates, ammonia, etc. can be used.

The second method of hydrolysis is to use a halide as a tin compound and a metal compound, and add an alcohol solution of these to an aqueous dispersion of micaceous powder, and the hydrolysis occurs under heating and in the presence of an alkali. The method promoted is the same as method 11.

The third method of hydrolysis is a method of adding an aqueous solution of a tin compound and a metal compound to an aqueous dispersion of micaceous powder,
Labor safety, environmental health, and
This method has high industrial applicability in terms of disaster prevention and economic efficiency. However, many tin compounds and metal compounds are hydrolyzed or altered when they are fused with water, and it is often difficult to obtain a stable aqueous solution, but a stable solution can be obtained by using an acidic or alkaline aqueous solution. In particular, tin compounds and halides of metal compounds are stable in an acidic aqueous solution of hydrochloric acid, and therefore are suitable for forming the solution of both metal compounds of the present invention.

When using these two metal compound solutions, if both metal compounds are in an acidic solution, the hydrolysis reaction can proceed with an alkaline substance, and conversely, if the two metal compounds are in an alkaline solution, they can be neutralized with an acidic substance to allow the hydrolysis reaction to proceed. Hydrolysis is accelerated by heating, as in the methods of ml and 12.

In the present invention, all the types and amounts of the tin compound solution and the metal compound solution may be mixed and added at the same time, but in order to adjust the composition of the deposited layer, each solution may be added separately or partially mixed. There are no particular restrictions on the method of addition, such as adding .

Through the above hydrolysis reaction, a water-insoluble hydrolyzate produced from the tin compound and the metal compound is deposited on the surface of the micaceous powder. Therefore, the solid matter in the slurry liquid is separated using means such as filtration, decantation, or centrifugation W1, and then washed with water and dried.

Next, to improve the conductivity and stability of the object,
About 200-1000°C, preferably about 400-800°C
Heat treated with During this heat treatment, reduction treatment can be performed as necessary to improve the conductivity. In this reduction treatment, a reducing gas such as hydrogen gas, ammonia gas, or carbon oxide may be used alone or in combination, or the separated product may be heat-treated in an inert gas atmosphere with carbon powder present or mixed. +11° (Example) An example will be given and explained below. Note that % simply indicates weight %.

Example 1 Phlogopite powder (80% passing through 60-200 meshes) 10
g in water and stirred for 30 minutes with a stirrer to form a slurry.Next, 2N aqueous potassium hydroxide solution was added to this dispersed slurry and heated to 80°C, and in this hot slurry A solution of 41 g of tetrabutoxytin and antimony-tribroboquine 38 dissolved in 50 g of propalol was added dropwise over about 1 hour.

After dropping, the solid matter was taken out, washed with water, dried, and then
The mixture was heated at 00° C. for 2 hours to obtain 25 g of conductive mica.

This conductive mica has a surface of phlogopite containing S containing 8% sb.
homogeneously coated with n O2, the coating layer accounts for 60% of the total composition
It was white and had good electrical conductivity with a volume resistivity of 1.2×10'Ω·ca+ under a pressure of 100 kgf/c+I+2.

Example 2 Muscovite powder (80% passing through 60-200 meshes) IO
, i was dispersed in water and stirred for 30 minutes using a stirrer to form a slurry. Next, this dispersion slurry was heated to 80°C in an oil bath, and this heated slurry [1 month of stannous chloride (SIICI2 .2 H2O) 22.5g%5bC
A solution of I, (4.5 g) dissolved in 100 parts of ethanol + 1 part of ethanol was added dropwise over 1 hour. After the dropwise addition was completed, the solid material was filtered, washed with water, dried, and heat treated in the same manner as in Example 1 to obtain 29 g of conductive mica. This conductive mica is
homogeneously coated with SnO, containing 15.7% SIJ,
Covering waste accounts for 65% of the total composition, and is white and weighs 100 kgf/
Volume resistivity 7.4×102Ω・ct under pressure of cta2
It had good conductivity.

Example 3 The same phlogopite powder used in Example 1 was dispersed and slurried in the same manner as in Example 1. This dispersed slurry was then heated to 80°C in an oil bath. In this hot slurry was dissolved 45% of 5IICI2 in water (!27 g, S 11c l.

(2.5 g) was dissolved in 25 ml of 3.7N hydrochloric acid, and an aqueous solution of antimony chloride in hydrochloric acid and a 3.7N aqueous sodium hydroxide solution from 75 companies were simultaneously added in equal amounts over an hour. After further heating and aging at 80°C for 1 hour, the solid matter was taken out in the same manner as in Example 1, washed with water, and dried.
Heating at 0°C for 1 hour yielded a conductive cloud IJ20.5H.

This conductive mica contains S n 0 with 12.3% SIJ
2, the 11th layer accounts for 51% of the total composition, is white and has a volume resistivity (hereinafter measured using the same method as in Example 1) of 2.
．． It had good conductivity of 5×10”Ω·ell+.

Example 4 In Example 3, the phlogopite powder was changed to synthetic phlogopite (Topy Industries, Ltd., Guimonai PDM-7), and the firing conditions were set to 50%.
The process was carried out in the same manner as in Example 3 except that the temperature was changed to 0°C for 12 hours, and the coating layer had almost the same composition as in Example 3, and the volume resistivity was 3. 19. White conductive mica with good conductivity of lXIO2Ω·eta. I got sg.

Example 5 15 g of the phlogopite powder used in Example 1 was dispersed in 100 g of water to form a slurry, and then heated to 90° C. to obtain a thermal slurry.

Then 17ml of 3.7N hydrochloric acid 11m S bCIs
(1,511) dissolved and 50% of 5nC1,
Aqueous solution 18 and homogeneously mixed solution of both metal compounds and 3.7
Using a metering pump, 75 + a l of a specified aqueous sodium hydroxide solution was added quantitatively and simultaneously to the hot slurry over a period of 1 hour, and then maintained at 90"C for another 1 hour to ripen.
Thereafter, the solid matter was removed, washed with water, and dried in the same manner as in Example 1.
Heating at 700°C for 1 hour, conductive mica 21. I got it.

This conductive mica is homogeneously coated with S n O2 containing 13% SI+, the coating layer is 29% of the total, and is white with a volume resistivity of 4. It exhibited a conductivity of lXl0'Ω·cIll.

Example 6 In Example 5, 3g of 5bC1 was dissolved in 3.7N hydrochloric acid 35 +ne, 5nC12.2H,O
35g of 45% water-soluble fi, 3.7N hydroxide) I
Conductive mica 27 was obtained in the same manner except that Jum 105 was used. This conductive mica contains S containing 13% Sb.
Ili is uniformly covered at l+02, and the coating layer accounts for 45% of the total.
It is white and has a volume resistance rp7,3X10'Ω・cIl
It showed a conductivity of 1.

Example 7 Conductive mica 20,511 was obtained in the same manner as in Example 6 except that S L CI 3 was changed to the same amount of innoum chloride (InCI). This conductive cloud 1 old soil 12.
Homogeneously coated with S n O2 containing 5% In,
The fi layer accounts for 44% of the total, is white and has a volume resistivity of 1.2.
It exhibited a conductivity of X 102Ω·cn.

Example 8 Conductive mica 21 was obtained in the same manner as in Example 6 except that the same amount of niobium chloride (NbCl) was used instead of S be I 3. This conductive cloud 1u contains 12.5% N
Homogeneously coated with SnO2 containing t+, the coating layer accounts for 27.5% of the total, is white, and has a volume resistivity of 4.3X 10
It was 2Ω·elQ.

(Effects of the Invention) According to the present invention, it is possible to obtain conductive mica that has an excellent reinforcing effect on plastics and is useful for industrial use and can be applied to conductive paints, inks, composite materials, and the like.

(that's all)

Claims (2)

[Claims] (1) The surface of the mica powder is coated with a coating layer containing 0.1 to 20% by weight of one or a mixture of two or more of the metal group consisting of antimony, indium, and niobium, with the remainder consisting essentially of tin oxide. 5 to 70% by weight of the total composition is coated with conductive mica. (2) A tin compound and a metal compound consisting of one or more of the metal group consisting of antimony, indium, and niobium are added in a solution state to an aqueous dispersion of micaceous powder, and then insoluble materials are separated. , a method for producing conductive mica, which is characterized by heat-treating the same.