CN105513716B - Inorganic light color conductive powder preparation method - Google Patents

Abstract

The invention provides an inorganic light color conductive powder preparation method, which obtains inorganic light color conductive powder with better conductivity and lighter colors through secondary coating and primary heat treatment processes. The method simultaneously improves the conductivity and whiteness of conductive powder through controlling different Sn-Sb ratios and covering amounts of internal and external coating layers, thereby realizing perfect unification of colors and conductivity of light color conductive powder, and reducing the usage of Sn and Sb and production costs.

Description

A kind of preparation method of inorganic light-color conductive powder

technical field

The invention relates to the technical field of inorganic functional materials, in particular to a preparation method of an inorganic coated conductive powder.

Background technique

Conductive powder has antistatic, conductive, shielding electromagnetic wave and other functions. It can be added as conductive filler in coating, chemical fiber, plastic, rubber and other materials, and can be made into various conductive and electromagnetic shielding products. It is widely used in electronics, automobiles, building materials, and chemical industry. , military and other fields have a wide range of applications.

Inorganic light-colored conductive powder is mainly divided into two categories: ①It is a coated conductive material, which is generally coated with titanium oxide, sepiolite, mica, potassium titanate, barite, etc. as nuclei on its surface. Tin oxide conductive layer of Sb, In, P, etc. Industrial conductive products are mainly tin oxide doped with Sb. The production cost of coated conductive products is low, but their volume resistivity is high. How to prepare products with lower volume resistivity under the same coating amount is urgently needed. solved problem. ② It is a doped conductive oxide powder. The common ones are conductive sepiolite and conductive tin oxide. The production process is to dope the oxide at high temperature to form a defect solid solution. This type of conductive powder has a lower volume resistivity, but its production cost is higher.

At present, conductivity and whiteness are the main factors that limit the wide application of this type of conductive powder, so it is an inevitable trend to develop light-colored conductive powder with light color and good conductivity.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the deficiencies in the background technology and provide a method for improving the whiteness and conductivity of inorganic light-colored conductive powder.

The technical scheme of the present invention is: disperse the nuclei into a suspension, uniformly deposit inner and outer layers of conductive precursor compound on its surface by chemical co-precipitation method, and improve the whiteness and conductivity.

The following characteristic steps that the present invention adopts:

(1) Preparation of nucleosome dispersion: add nucleosomes to deionized water and stir evenly to obtain a nucleosome dispersion, wherein the mass ratio of nucleosomes to deionized water is 1:4-1:20.

(2) Preparation of tin-antimony hydrochloric acid mixed solution: Add tin tetrachloride pentahydrate and antimony trichloride to 1-3mol/L hydrochloric acid solution, stir until all solids are dissolved, transfer to a volumetric flask, and prepare dihydrochloride at constant volume A mixed solution of hydrochloric acid with different ratios of tin to antimony.

(3) Primary coating: heat the nucleosome dispersion in step (1) to 50-90°C, adjust its pH to 0.5-5, and add tin in a ratio described in step (2) dropwise while stirring antimony hydrochloric acid mixed solution, while adding dropwise alkaline solution to keep the pH constant, wherein the mass ratio of SnCl ₄ ·5H ₂ O to potassium titanate is 0.4-1.0:1. After the tin-antimony hydrochloric acid mixed solution is added dropwise, continue the heat preservation reaction for 0.5-1 hour, then filter the suspension and wash it with deionized water until the conductivity of the filtrate is ≤200 μS/cm to obtain a primary-coated nucleosome filter cake.

(4) Secondary coating: disperse the nuclei filter cake which is coated once in step (3) in deionized water to obtain a dispersion, wherein the mass ratio of powder to deionized water is 1:4～1: 20. Adjust the pH value of the dispersion to 0.5-5, raise the temperature to 50-90°C, add dropwise a mixed solution of tin-antimony hydrochloric acid different from the tin-antimony ratio added dropwise in step (3) while stirring, and add dropwise an alkaline solution at the same time. Keep the pH constant, and the mass ratio of SnCl ₄ ·5H ₂ O to nuclei is 0.4-1.0:1. After the tin-antimony hydrochloric acid mixed solution is added dropwise, continue the heat preservation reaction for 0.5-1 hour, then filter the suspension and wash it with deionized water until the conductivity of the filtrate is ≤200 μS/cm to obtain a secondary coated nucleosome filter cake.

(5) Heat treatment: dry and pulverize the secondary coated nucleosome filter cake obtained in step (4), and then heat-preserve and solid-state reaction at 400-700°C for 0.5-2.5h to obtain the good conductivity prepared by the present invention , Light-colored conductive powder with high whiteness.

The nuclei in the step (1) can be one of rod-shaped potassium titanate, titanium dioxide, mica powder, silicon dioxide, attapulgite, sepiolite, halloysite and pyrophyllite;

The mass concentration of the tin-antimony hydrochloric acid mixed solution in the step (2) is 0.2-0.6 g/mL (calculated as SnCl ₄ ·5H ₂ O);

The mass ratio of tin tetrachloride pentahydrate and antimony trichloride in the tin-antimony hydrochloric acid mixed solution in the step (3) is m(SnCl ₄ ·5H ₂ O): m(SbCl ₃ )=4～7: 1;

The mass ratio of tin tetrachloride pentahydrate and antimony trichloride in the tin-antimony hydrochloric acid mixed solution in the step (4) is m(SnCl ₄ ·5H ₂ O): m(SbCl ₃ )=8～20: 1;

The alkaline solution in described step (3) and step (4) is sodium hydroxide, ammoniacal liquor, potassium hydroxide solution, sodium bicarbonate, ammonium bicarbonate, ammonium carbonate, and wherein the substance mass concentration of alkaline solution is 1 ~4mol/L.

The beneficial effects of the present invention are:

1. By controlling the different tin-antimony ratios and coating amounts of the inner and outer coating layers, the conductivity and whiteness of the conductive powder can be improved at the same time, and the perfect unity of color and conductivity of the light-colored conductive powder can be realized.

2. Reasonable control of the ratio of tin to antimony can not only reduce the amount of tin and antimony to reduce production costs, but also prepare conductive powder with high whiteness and good conductivity.

detailed description

Example 1:

Below in conjunction with specific embodiment, further illustrate the present invention, should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention, after having read the present invention, those skilled in the art will understand various equivalent forms of the present invention All modifications fall within the scope defined by the appended claims of the present application.

The mensuration of powder volume resistivity of the present invention:

Put 10g of conductive attapulgite into a graduated polyacrylate glass tube, press the conductive powder between the two metal sheets with a pressure of 9.81×10 ⁵ Pa, measure the resistance between the two metal sheets with a multimeter, according to The thickness and cross-sectional area of the powder layer are used to calculate the resistivity of the powder according to the following formula:

Rsp=R×A/L where Rsp is the volume resistivity (Ω·cm), R is the actual measured resistance (Ω), A is the cross-sectional area of the inner diameter of the glass tube (cm ² ), L is the height of the conductive powder layer (cm) .

The mensuration of powder whiteness of the present invention:

The whiteness is measured according to the national standard GB/T 23774-2009, standard name: general method for the determination of whiteness of inorganic chemical products.

Example 1

(1) Preparation of potassium titanate dispersion: Take 1.0 kg of potassium titanate powder and add it to 6.67 kg of deionized water, and stir evenly to obtain a potassium titanate dispersion, which is set aside.

(2) Preparation of mixed solution of tin-antimony hydrochloric acid: ① Preparation of mixed solution of tin-antimony hydrochloric acid coated once: add 0.7kg tin tetrachloride pentahydrate and 0.175kg antimony trichloride to 3mol/L hydrochloric acid solution, stir until solid Dissolve it completely, transfer it to a volumetric flask, and prepare a 0.4g/mL tin-antimony hydrochloric acid mixed solution for later use; Add antimony trichloride to 3mol/L hydrochloric acid solution, stir until all solids are dissolved, transfer to a volumetric flask, and constant volume to prepare 0.4g/mL tin-antimony hydrochloric acid mixed solution, set aside.

(3) Primary coating: Heat the potassium titanate dispersion prepared in step (1) to 90°C, adjust its pH value to 2.75, add 1.75L of 0.4g/mL tin-antimony hydrochloric acid mixed solution ① dropwise while stirring, and at the same time Add 2.5 mol/L ammonia solution dropwise to keep the pH constant. After the tin-antimony hydrochloric acid mixed solution was added dropwise, the heat preservation reaction was continued for 0.5 h, and then the suspension was filtered and washed with deionized water until the conductivity of the filtrate was 125 μS/cm to obtain a primary coated potassium titanate filter cake.

(4) Secondary coating: disperse the primary coated potassium titanate filter cake obtained in step (4) in deionized water to prepare a dispersion, wherein the mass ratio of powder to deionized water is 1:6.67. Adjust the pH value of the dispersion to 2.75, raise the temperature to 90°C, add 2.5L 0.4g/mL tin-antimony hydrochloric acid mixed solution ② dropwise while stirring, and add 2.5mol/L ammonia solution dropwise to keep the pH constant. After the tin-antimony hydrochloric acid mixed solution was added dropwise, the heat preservation reaction was continued for 0.5 h, and then the suspension was filtered and washed with deionized water until the conductivity of the filtrate was 135 μS/cm to obtain a secondary coated potassium titanate filter cake.

(5) Heat treatment: dry and pulverize the secondary coated potassium titanate filter cake obtained in step (4), then place the powder in a muffle furnace, raise the temperature to 400°C, and hold it at 400°C for solidification The phase reaction was carried out for 2.5 hours, and a light-colored potassium titanate conductive powder was prepared. The volume resistivity of the powder was 3.7Ω·cm, and the whiteness was 86.0.

Example 2

(1) Preparation of titanium dioxide dispersion: Take 1.0 kg of rutile titanium dioxide powder with an average particle size of 0.25 μm and add it to 4 kg of deionized water, stir evenly to obtain a titanium dioxide dispersion, which is set aside.

(2) Preparation of mixed solution of tin-antimony hydrochloric acid: ① Preparation of mixed solution of tin-antimony hydrochloric acid coated once: add 0.4kg tin tetrachloride pentahydrate and 0.073kg antimony trichloride to 2mol/L hydrochloric acid solution, stir until solid Dissolve it completely, transfer it to a volumetric flask, and make a 0.2g/mL tin-antimony hydrochloric acid mixed solution for later use; Add antimony trichloride to 2mol/L hydrochloric acid solution, stir until the solids are completely dissolved, transfer to a volumetric flask, and constant volume to prepare a 0.2g/mL tin-antimony hydrochloric acid mixed solution for later use.

(3) Primary coating: Heat the titanium oxide dispersion prepared in step (1) to 50°C, adjust its pH value to 5, add 2L of 0.2g/mL tin-antimony hydrochloric acid mixed solution ① dropwise while stirring, and add dropwise 1 mol/L sodium hydroxide solution to maintain the pH constant. After the tin-antimony hydrochloric acid mixed solution was added dropwise, the heat preservation reaction was continued for 1 h, and then the suspension was filtered and washed with deionized water until the conductivity of the filtrate was 176 μS/cm to obtain a primary coated titanium oxide filter cake.

(4) Secondary coating: disperse the primary coated titanium oxide filter cake obtained in step (3) in deionized water to prepare a dispersion liquid, wherein the mass ratio of powder to deionized water is 1:4. Adjust the pH value of the dispersion to 5, raise the temperature to 50°C, add dropwise 3.5L of 0.2g/mL tin antimony hydrochloric acid mixed solution② while stirring, and at the same time add dropwise 1mol/L sodium hydroxide solution to keep the pH constant. After the tin-antimony hydrochloric acid mixed solution was added dropwise, the heat preservation reaction was continued for 1 h, and then the suspension was filtered and washed with deionized water until the conductivity of the filtrate was 134 μS/cm to obtain a secondary coated titanium oxide filter cake.

(5) Heat treatment: dry and pulverize the secondary coated titanium oxide filter cake obtained in step (4), then place the powder in a muffle furnace, raise the temperature to 700°C, and keep the solid phase at 700°C After reacting for 0.5h, a light-colored titanium oxide conductive powder was prepared, the volume resistivity of the powder was 2.6Ω·cm, and the whiteness was 84.5.

Example 3

(1) Preparation of mica dispersion: 1.0 kg of 325-mesh sericite powder was added to 20 kg of deionized water, stirred evenly to obtain a mica dispersion, and set aside.

(2) Preparation of mixed solution of tin-antimony hydrochloric acid: ① Preparation of mixed solution of tin-antimony hydrochloric acid coated once: add 1kg tin tetrachloride pentahydrate and 0.143kg antimony trichloride to 2mol/L hydrochloric acid solution, stir until all solids dissolved, transferred to a volumetric flask, and made to a constant volume to prepare a mixed solution of 0.6g/mL tin-antimony hydrochloric acid, and set aside; Add antimony chloride to 2mol/L hydrochloric acid solution, stir until the solids are completely dissolved, transfer to a volumetric flask, and constant volume to prepare a 0.6g/mL tin-antimony hydrochloric acid mixed solution for later use.

(3) Primary coating: Heat the prepared mica dispersion in step (1) to 70°C, adjust its pH value to 0.5, add 1.67L 0.6g/mL tin-antimony hydrochloric acid mixed solution ① dropwise while stirring, and add dropwise 4 mol/L potassium hydroxide solution was used to maintain the pH constant. After the tin-antimony hydrochloric acid mixed solution was added dropwise, the heat preservation reaction was continued for 0.75 h, and then the suspension was filtered and washed with deionized water until the conductivity of the filtrate was 155 μS/cm, and a primary coated mica filter cake was obtained.

(4) Secondary coating: disperse the primary coated mica filter cake obtained in step (3) in deionized water to prepare a dispersion liquid, wherein the mass ratio of powder to deionized water is 1:6.67. Adjust the pH value of the dispersion to 0.5, raise the temperature to 70°C, add dropwise 0.67L 0.6g/mL tin-antimony hydrochloric acid mixed solution② while stirring, and add dropwise 4mol/L potassium hydroxide solution to keep the pH constant. After the tin-antimony hydrochloric acid mixed solution was added dropwise, the heat preservation reaction was continued for 0.75 h, and then the suspension was filtered and washed with deionized water until the conductivity of the filtrate was 115 μS/cm to obtain a secondary coated mica filter cake.

(5) Heat treatment: dry and pulverize the secondary coated mica filter cake obtained in step (4), then place the powder in a muffle furnace, raise the temperature to 550°C, and conduct a solid-state reaction at 550°C After 1.5 hours, a light-colored mica conductive powder was prepared, the volume resistivity of the powder was 4.2Ω·cm, and the whiteness was 85.0.

Example 4

(1) Preparation of potassium titanate dispersion: Take 1.0 kg of needle-shaped potassium octatitanate powder and add it to 10 kg of deionized water, and stir evenly to obtain a potassium titanate dispersion, which is set aside.

(2) Preparation of mixed solution of tin-antimony hydrochloric acid: ① Preparation of mixed solution of tin-antimony hydrochloric acid coated once: add 0.4kg tin tetrachloride pentahydrate and 0.1kg antimony trichloride to 3mol/L hydrochloric acid solution, stir until solid Dissolve it completely, transfer it to a volumetric flask, and prepare a 0.4g/mL tin-antimony hydrochloric acid mixed solution for later use; Add antimony trichloride to 3mol/L hydrochloric acid solution, stir until all solids are dissolved, transfer to a volumetric flask, and constant volume to prepare 0.4g/mL tin-antimony hydrochloric acid mixed solution, set aside.

(3) Primary coating: Heat the potassium titanate dispersion prepared in step (1) to 70°C, adjust its pH value to 2.75, add 1L of 0.4g/mL tin-antimony hydrochloric acid mixed solution ① dropwise while stirring, and drop at the same time Add 2.5mol/L ammonia solution to keep the pH constant. After the tin-antimony hydrochloric acid mixed solution was added dropwise, the heat preservation reaction was continued for 0.5 h, and then the suspension was filtered and washed with deionized water until the conductivity of the filtrate was 105 μS/cm to obtain a primary coated potassium titanate filter cake.

(4) Secondary coating: disperse the primary coated potassium titanate filter cake obtained in step (3) in deionized water to prepare a dispersion liquid, wherein the mass ratio of powder to deionized water is 1:10. Adjust the pH value of the dispersion to 2.75, raise the temperature to 70°C, add 1L of 0.4g/mL tin-antimony hydrochloric acid mixed solution ② dropwise while stirring, and at the same time add dropwise 2.5mol/L ammonia solution to keep the pH constant. After the tin-antimony hydrochloric acid mixed solution was added dropwise, the heat preservation reaction was continued for 0.5 h, and then the suspension was filtered and washed with deionized water until the conductivity of the filtrate was 183 μS/cm to obtain a secondary coated potassium titanate filter cake.

(5) Heat treatment: dry and pulverize the secondary coated potassium titanate filter cake obtained in step (4), then place the powder in a muffle furnace, raise the temperature to 550°C, and hold it at 550°C for solidification The phase reaction was carried out for 1.5 hours, and a light-colored potassium titanate conductive powder was prepared. The volume resistivity of the powder was 3.9Ω·cm, and the whiteness was 85.5.

Example 5

(1) Preparation of sepiolite dispersion: Take 1.0 kg of 325-mesh sepiolite powder and add it to 6.67 kg of deionized water, stir evenly to obtain sepiolite dispersion, and set aside.

(2) Preparation of mixed solution of tin-antimony hydrochloric acid: ① Preparation of mixed solution of tin-antimony hydrochloric acid coated once: add 1kg tin tetrachloride pentahydrate and 0.25kg antimony trichloride to 2mol/L hydrochloric acid solution, stir until all solids dissolved, transferred to a volumetric flask, and made to a constant volume to prepare a mixed solution of 0.6g/mL tin-antimony hydrochloric acid, and set aside; Add antimony chloride to 2mol/L hydrochloric acid solution, stir until the solids are completely dissolved, transfer to a volumetric flask, and constant volume to prepare a 0.6g/mL tin-antimony hydrochloric acid mixed solution for later use.

(3) Primary coating: heat the spare sepiolite dispersion in step (1) to 90°C, adjust its pH value to 5, add 1.67L 0.6g/mL tin-antimony hydrochloric acid mixed solution ① dropwise while stirring, and at the same time Add 4 mol/L ammonium bicarbonate solution dropwise to maintain the pH. After the tin-antimony hydrochloric acid mixed solution was added dropwise, the heat preservation reaction was continued for 0.75 h, and then the suspension was filtered and washed with deionized water until the conductivity of the filtrate was 185 μS/cm to obtain a primary coated sepiolite filter cake.

(4) Secondary coating: disperse the primary coated sepiolite filter cake obtained in step (3) in deionized water to prepare a dispersion, wherein the mass ratio of powder to deionized water is 1:6.67. Adjust the pH value of the dispersion to 5, raise the temperature to 90°C, add 1.67L 0.6g/mL tin-antimony hydrochloric acid mixed solution ② dropwise while stirring, and add 4mol/L ammonium bicarbonate solution dropwise to keep the pH constant. After the tin-antimony hydrochloric acid mixed solution was added dropwise, the heat preservation reaction was continued for 0.75 h, and then the suspension was filtered and washed with deionized water until the conductivity of the filtrate was 127 μS/cm to obtain a secondary coated sepiolite filter cake.

(5) Heat treatment: dry and pulverize the secondary coated sepiolite filter cake obtained in step (4), then place the powder in a muffle furnace, raise the temperature to 700°C, and keep it solid at 700°C The phase reaction was carried out for 0.5h, and a light-colored sepiolite conductive powder was prepared. The volume resistivity of the powder was 5.8Ω·cm, and the whiteness was 87.0.

Example 6

(1) Preparation of mica titanium dispersion: Take 1.0 kg of 800-mesh muscovite titanium powder and add it to 4 kg of deionized water, stir evenly to obtain a mica titanium dispersion, which is set aside.

(2) Preparation of mixed solution of tin-antimony hydrochloric acid: ① Preparation of mixed solution of tin-antimony hydrochloric acid coated once: add 1kg tin tetrachloride pentahydrate and 0.25kg antimony trichloride to 1mol/L hydrochloric acid solution, stir until all solids dissolved, transferred to a volumetric flask, and made to a constant volume to prepare a mixed solution of 0.2g/mL tin-antimony hydrochloric acid, and set aside; Add antimony chloride to 1mol/L hydrochloric acid solution, stir until the solids are completely dissolved, transfer to a volumetric flask, and constant volume to prepare a 0.2g/mL tin-antimony hydrochloric acid mixed solution for later use.

(3) Primary coating: Heat the prepared mica-titanium dispersion in step (1) to 70°C, adjust its pH value to 2.75, add 5L 0.42/mL tin-antimony hydrochloric acid mixed solution ① dropwise while stirring, and simultaneously add 2.5 mol/L sodium hydroxide solution to maintain the pH constant. After the tin-antimony hydrochloric acid mixed solution was added dropwise, the reaction was continued for 0.75 h, and then the suspension was filtered and washed with deionized water until the conductivity of the filtrate was 145 μS/cm to obtain a primary coated mica titanium filter cake.

(4) Secondary coating: disperse the primary coated mica titanium filter cake obtained in step (3) in deionized water to prepare a dispersion liquid, wherein the mass ratio of powder to deionized water is 1:4. Adjust the pH value of the dispersion to 2.75, raise the temperature to 70°C, add dropwise 5L of 0.2g/mL tin-antimony hydrochloric acid mixed solution② while stirring, and at the same time add dropwise 2.5mol/L sodium hydroxide solution to keep the pH constant. After the tin-antimony hydrochloric acid mixed solution was added dropwise, the heat preservation reaction was continued for 0.75h, and then the suspension was filtered and washed with deionized water until the conductivity of the filtrate was 169 μS/cm to obtain a secondary coated mica-titanium filter cake.

(5) Heat treatment: dry and pulverize the secondary coated mica titanium filter cake obtained in step (4), then place the powder in a muffle furnace to raise the temperature to 400°C, and conduct a solid-state reaction at 400°C for 2.5 h, light-colored mica-titanium conductive powder was prepared, the volume resistivity of the powder was 3.4Ω·cm, and the whiteness was 84.0.

Comparative example 1

In the comparative example, the ratio of tin and antimony in the secondary coating in the embodiment 1 is interchanged, and other operating conditions are the same as in the embodiment 1, and the specific operations are as follows:

(1) Preparation of potassium titanate dispersion: Take 1.0 kg of potassium hexatitanate powder and add it into 6.67 kg of deionized water, and stir evenly to obtain a potassium titanate dispersion, which is set aside.

(2) Preparation of mixed solution of tin-antimony hydrochloric acid: ① Preparation of mixed solution of tin-antimony hydrochloric acid coated once: add 1.0kg tin tetrachloride pentahydrate and 0.07kg antimony trichloride to 3mol/L hydrochloric acid solution, stir until all solids Dissolve, transfer to a volumetric flask, and make a 0.4g/mL tin-antimony hydrochloric acid mixed solution at constant volume for later use; ②Preparation of the tin-antimony hydrochloric acid mixed solution for secondary coating: 0.7kg tin tetrachloride pentahydrate and 0.175kg trichlorohydrin Add antimony trichloride to 3mol/L hydrochloric acid solution, stir until the solids are completely dissolved, transfer to a volumetric flask, and constant volume to prepare a 0.4g/mL tin-antimony hydrochloric acid mixed solution for later use.

(3) Primary coating: Heat the potassium titanate dispersion prepared in step (1) to 90°C, adjust its pH value to 2.75, add 1.5L of 0.4g/mL tin-antimony hydrochloric acid mixed solution ① dropwise while stirring, and at the same time Add 2.5 mol/L ammonia solution dropwise to keep the pH constant. After the tin-antimony hydrochloric acid mixed solution was added dropwise, the heat preservation reaction was continued for 0.5 h, and then the suspension was filtered and washed with deionized water until the conductivity of the filtrate was 125 μS/cm to obtain a primary coated potassium titanate filter cake.

(4) Secondary coating: the primary coated potassium titanate filter cake obtained in step (3) was dispersed in deionized water to prepare a dispersion liquid, wherein the mass ratio of powder to deionized water was 1:6.67. Adjust the pH value of the dispersion to 2.75, raise the temperature to 90°C, add 1.75L 0.4g/mL tin-antimony hydrochloric acid mixed solution ② dropwise while stirring, and at the same time add dropwise 2.5mol/L ammonia solution to keep the pH constant. After the tin-antimony hydrochloric acid mixed solution was added dropwise, the heat preservation reaction was continued for 0.5 h, and then the suspension was filtered and washed with deionized water until the conductivity of the filtrate was 148 μS/cm to obtain a secondary coated potassium titanate filter cake.

(5) Heat treatment: dry and pulverize the secondary coated potassium titanate filter cake obtained in step (4), then place the powder in a muffle furnace to raise the temperature to 400°C, and keep the solid phase at 400°C After reacting for 2.5 hours, a light-colored potassium titanate conductive powder was prepared, the volume resistivity of the powder was 87Ω·cm, and the whiteness was 65.5.

Comparative example 2

In the comparative example, the tin-antimony ratio in the secondary coating in Example 1 is all coated by the tin-antimony ratio of the primary coating in Example 1, and other operating conditions are the same as in Example 1, and the specific operations are as follows:

(1) Preparation of potassium titanate dispersion: Take 1.0 kg of potassium hexatitanate powder and add it into 6.67 kg of deionized water, and stir evenly to obtain a potassium titanate dispersion, which is set aside.

(2) Preparation of mixed solution of tin-antimony hydrochloric acid: ① Preparation of mixed solution of tin-antimony hydrochloric acid coated once: add 0.7kg tin tetrachloride pentahydrate and 0.175kg antimony trichloride to 3mol/L hydrochloric acid solution, stir until solid Dissolve it completely, transfer it to a volumetric flask, and make a 0.4g/mL tin-antimony hydrochloric acid mixed solution for later use; Add antimony trichloride to 3mol/L hydrochloric acid solution, stir until all solids are dissolved, transfer to a volumetric flask, and constant volume to prepare 0.4g/mL tin-antimony hydrochloric acid mixed solution, set aside.

(3) Primary coating: Heat the potassium titanate dispersion prepared in step (1) to 90°C, adjust its pH value to 2.75, add 1.75L of 0.4g/mL tin-antimony hydrochloric acid mixed solution ① dropwise while stirring, and at the same time Add 2.5 mol/L ammonia solution dropwise to keep the pH constant. After the tin-antimony hydrochloric acid mixed solution was added dropwise, the heat preservation reaction was continued for 0.5 h, and then the suspension was filtered and washed with deionized water until the conductivity of the filtrate was 125 μS/cm to obtain a primary coated potassium titanate filter cake.

(4) Secondary coating: the primary coated potassium titanate filter cake obtained in step (3) was dispersed in deionized water to prepare a dispersion liquid, wherein the mass ratio of powder to deionized water was 1:6.67. Adjust the pH value of the dispersion to 2.75, raise the temperature to 90°C, add 2.5L 0.4g/mL tin-antimony hydrochloric acid mixed solution ② dropwise while stirring, and add 2.5mol/L ammonia solution dropwise to keep the pH constant. After the tin-antimony hydrochloric acid mixed solution was added dropwise, the heat preservation reaction was continued for 0.5 h, and then the suspension was filtered and washed with deionized water until the conductivity of the filtrate was 146 μS/cm to obtain a secondary coated potassium titanate filter cake.

(5) Heat treatment: dry and pulverize the secondary coated potassium titanate filter cake obtained in step (4), then place the powder in a muffle furnace to raise the temperature to 400°C, and keep the solid phase at 400°C After reacting for 2.5 hours, a light-colored potassium titanate conductive powder was prepared. The volume resistivity of the powder was 76Ω·cm, and the whiteness was 62.5.

Comparative example 3

In the comparative example, the tin-antimony ratio in the secondary coating in Example 1 is all coated by the tin-antimony ratio of the secondary coating in Example 1, and other operating conditions are the same as in Example 1, and the specific operations are as follows:

(1) Preparation of potassium titanate dispersion: Take 1.0 kg of potassium hexatitanate powder and add it into 6.67 kg of deionized water, and stir evenly to obtain a potassium titanate dispersion, which is set aside.

(2) Preparation of mixed solution of tin-antimony hydrochloric acid: ① Preparation of mixed solution of tin-antimony hydrochloric acid coated once: add 0.7kg tin tetrachloride pentahydrate and 0.05kg antimony trichloride to 3mol/L hydrochloric acid solution, stir until solid Dissolve it completely, transfer it to a volumetric flask, and prepare a 0.4g/mL tin-antimony hydrochloric acid mixed solution for later use; Add antimony trichloride to 3mol/L hydrochloric acid solution, stir until all solids are dissolved, transfer to a volumetric flask, and constant volume to prepare 0.4g/mL tin-antimony hydrochloric acid mixed solution, set aside.

(3) Primary coating: Heat the potassium titanate dispersion prepared in step (1) to 90°C, adjust its pH value to 2.75, add 1.75L of 0.4g/mL tin-antimony hydrochloric acid mixed solution ① dropwise while stirring, and at the same time Add 2.5 mol/L ammonia solution dropwise to keep the pH constant. After the tin-antimony hydrochloric acid mixed solution was added dropwise, the heat preservation reaction was continued for 0.5 h, and then the suspension was filtered and washed with deionized water until the conductivity of the filtrate was 125 μS/cm to obtain a primary coated potassium titanate filter cake.

(4) Secondary coating: the primary coated potassium titanate filter cake obtained in step (3) was dispersed in deionized water to prepare a dispersion liquid, wherein the mass ratio of powder to deionized water was 1:6.67. Adjust the pH value of the dispersion to 2.75, raise the temperature to 90°C, add 2.5L 0.4g/mL tin-antimony hydrochloric acid mixed solution ② dropwise while stirring, and add 2.5mol/L ammonia solution dropwise to keep the pH constant. After the tin-antimony hydrochloric acid mixed solution was added dropwise, the heat preservation reaction was continued for 0.5 h, and then the suspension was filtered and washed with deionized water until the conductivity of the filtrate was 192 μS/cm to obtain a secondary coated potassium titanate filter cake.

(5) Heat treatment: dry and pulverize the secondary coated potassium titanate filter cake obtained in step (4), then place the powder in a muffle furnace to raise the temperature to 400°C, and keep the solid phase at 400°C After reacting for 2.5 hours, a light-colored potassium titanate conductive powder was prepared. The volume resistivity of the powder was 74Ω·cm, and the whiteness was 70.0.

Comparative example 4

In the comparative example, the tin-antimony ratio in the secondary coating in Example 1 is coated by the arithmetic mean value of the tin-antimony ratio in the secondary coating in Example 1, and other operating conditions are the same as in Example 1, and the specific operations are as follows :

(1) Preparation of potassium titanate dispersion: Take 1.0 kg of needle-shaped potassium hexatitanate powder and add it into 6.67 kg of deionized water, and stir evenly to obtain a potassium titanate dispersion, which is set aside.

(2) Preparation of mixed solution of tin-antimony hydrochloric acid: ① Preparation of mixed solution of tin-antimony hydrochloric acid coated once: add 0.7kg tin tetrachloride pentahydrate and 0.078kg antimony trichloride to 3mol/L hydrochloric acid solution, stir until solid Dissolve it completely, transfer it to a volumetric flask, and make a 0.4g/mL tin-antimony hydrochloric acid mixed solution for later use; Add antimony trichloride to 3mol/L hydrochloric acid solution, stir until all solids are dissolved, transfer to a volumetric flask, and constant volume to prepare 0.4g/mL tin-antimony hydrochloric acid mixed solution, set aside.

(3) Primary coating: Heat the potassium titanate dispersion prepared in step (1) to 90°C, adjust its pH value to 2.75, add 1.75L of 0.4g/mL tin-antimony hydrochloric acid mixed solution ① dropwise while stirring, and at the same time Add 2.5 mol/L ammonia solution dropwise to keep the pH constant. After the tin-antimony hydrochloric acid mixed solution was added dropwise, the heat preservation reaction was continued for 0.5 h, and then the suspension was filtered and washed with deionized water until the conductivity of the filtrate was 125 μS/cm to obtain a primary coated potassium titanate filter cake.

(4) Secondary coating: disperse the primary coated potassium titanate filter cake obtained in step (4) in deionized water to prepare a dispersion, wherein the mass ratio of powder to deionized water is 1:6.67. Adjust the pH value of the dispersion to 2.75, raise the temperature to 90°C, add 2.5L 0.4g/mL tin-antimony hydrochloric acid mixed solution ② dropwise while stirring, and add 2.5mol/L ammonia solution dropwise to keep the pH constant. After the tin-antimony hydrochloric acid mixed solution was added dropwise, the heat preservation reaction was continued for 0.5 h, and then the suspension was filtered and washed with deionized water until the conductivity of the filtrate was 135 μS/cm to obtain a secondary coated potassium titanate filter cake.

(5) Heat treatment: dry and pulverize the secondary coated potassium titanate filter cake obtained in step (4), then place the powder in a muffle furnace and heat up to to 400°C, and kept at 400°C for solid-state reaction for 2.5 hours to prepare a light-colored potassium titanate conductive powder with a volume resistivity of 67Ω·cm and a whiteness of 69.5.

Comparative example 5

In the comparative example, the secondary coating in Example 1 is simplified into primary coating. Under the same coating amount, the tin-antimony ratio in the coating process is coated according to the tin-antimony ratio of the primary coating in Example 1. Other operations Condition is the same as embodiment 1, and concrete operation is as follows:

(1) Preparation of potassium titanate dispersion: Take 1.0 kg of potassium titanate powder and add it to 6.67 kg of deionized water, and stir evenly to obtain a potassium titanate dispersion, which is set aside.

(2) Preparation of tin-antimony hydrochloric acid mixed solution: add 1.7kg tin tetrachloride pentahydrate and 0.425kg antimony trichloride to 3mol/L hydrochloric acid solution, stir until all solids are dissolved, transfer to volumetric flask, and prepare Obtain 0.4g/mL tin antimony hydrochloric acid mixed solution, set aside;

(3) Coating: Heat the potassium titanate dispersion prepared in step (1) to 90°C, adjust its pH value to 2.75, add 4.25L 0.4g/mL tin-antimony hydrochloric acid mixed solution dropwise while stirring, and add dropwise 2.5mol/L ammonia solution to maintain the pH constant. After the tin-antimony hydrochloric acid mixed solution was added dropwise, the heat preservation reaction was continued for 0.5 h, and then the suspension was filtered and washed with deionized water until the conductivity of the filtrate was 125 μS/cm to obtain a coated potassium titanate filter cake.

(4) Heat treatment: dry and pulverize the secondary coated potassium titanate filter cake obtained in step (3), then place the powder in a muffle furnace, raise the temperature to 400°C, and hold it at 400°C for solidification The phase reaction was carried out for 2.5 hours, and a light-colored potassium titanate conductive powder was prepared. The volume resistivity of the powder was 79Ω·cm, and the whiteness was 66.0.

Comparative example 6

In the comparative example, the secondary coating in Example 1 is simplified to primary coating, and the tin-antimony ratio in the coating process is covered according to the tin-antimony ratio in the secondary coating in Example 1 under the same coating amount, and other operations Condition is the same as embodiment 1, and concrete operation is as follows:

(1) Preparation of potassium titanate dispersion: Take 1.0 kg of potassium titanate powder and add it to 6.67 kg of deionized water, and stir evenly to obtain a potassium titanate dispersion, which is set aside.

(2) Preparation of tin-antimony hydrochloric acid mixed solution: add 1.7kg tin tetrachloride pentahydrate and 0.121kg antimony trichloride to 3mol/L hydrochloric acid solution, stir until all solids are dissolved, transfer to volumetric flask, and prepare Obtain 0.4g/mL tin-antimony hydrochloric acid mixed solution, set aside.

(3) Coating: Heat the potassium titanate dispersion prepared in step (1) to 90°C, adjust its pH value to 2.75, add 4.25L 0.4g/mL tin-antimony hydrochloric acid mixed solution dropwise while stirring, and add dropwise 2.5mol/L ammonia solution to maintain the pH constant. After the tin-antimony hydrochloric acid mixed solution was added dropwise, the heat preservation reaction was continued for 0.5 h, and then the suspension was filtered and washed with deionized water until the conductivity of the filtrate was 125 μS/cm to obtain a coated potassium titanate filter cake.

(4) Heat treatment: dry and pulverize the secondary coated potassium titanate filter cake obtained in step (4), then place the powder in a muffle furnace, raise the temperature to 400°C, and hold it at 400°C for solidification The phase reaction was carried out for 2.5 hours, and a light-colored potassium titanate conductive powder was prepared. The volume resistivity of the powder was 77Ω·cm, and the whiteness was 73.0.

The electrical conductivity and whiteness of the embodiments of the present invention and comparative examples are shown in Table 1 below: From the examples and comparative examples and the following table, it can be seen that the present invention can improve the whiteness and electrical conductivity of the conductive powder.

Table 1 is the test of the conductive powder properties prepared by embodiments of the present invention and its comparative examples

Conductivity (Ω·cm) BaiDu Example 1 3.7 86.0 Example 2 2.6 84.5 Example 3 4.2 85.0 Example 4 3.9 85.5 Example 5 5.8 87.0 Example 6 3.4 84.0 Comparative example 1 87 65.5 Comparative example 2 76 62.5 Comparative example 3 74 70.0 Comparative example 4 67 69.5 Comparative example 5 79 66.0 Comparative example 6 77 73.0

Claims (7)

1. A preparation method for an inorganic light-colored conductive powder, characterized in that: the powder is prepared in the following steps: (1) Preparation of nucleosome dispersion: add nucleosome to deionized water, stir to obtain nucleosome dispersion; (2) Preparation of tin-antimony hydrochloric acid mixed solution: Add tin tetrachloride pentahydrate and antimony trichloride to 1-3mol/L hydrochloric acid solution, stir until all solids are dissolved, transfer to a volumetric flask, and prepare dihydrochloride at constant volume A mixed solution of hydrochloric acid with different tin-antimony ratios; (3) Primary coating: heat the nucleosome dispersion in step (1) to 50-90°C, adjust its pH to 0.5-5, and add tin in a ratio described in step (2) dropwise while stirring Antimony hydrochloric acid mixed solution, add alkaline solution dropwise at the same time to keep the pH constant, after the tin antimony hydrochloric acid mixed solution is added dropwise, continue to keep warm for 0.5~1h, then filter the suspension and wash it with deionized water until the conductivity of the filtrate is ≤200μS /cm, to obtain a coated nucleosome filter cake; (4) Secondary coating: disperse the primary coated nucleus filter cake obtained in step (3) in deionized water to obtain a dispersion, adjust the pH value of the dispersion to 0.5-5, and heat up to 50-50 90°C, while stirring, add dropwise a tin-antimony hydrochloric acid mixed solution different from the tin-antimony ratio added dropwise in step (3), and add an alkaline solution dropwise at the same time to keep the pH constant. After the tin-antimony hydrochloric acid mixed solution is added dropwise, continue Insulate and react for 0.5-1h, then filter the suspension and wash with deionized water until the conductivity of the filtrate is ≤200μS/cm to obtain a secondary coated nucleosome filter cake; (5) Heat treatment: dry and pulverize the nucleosome filter cake of the secondary coating obtained in step (4), and then heat-preserve and solid-phase reaction to obtain the light-colored conductive powder with good conductivity and high whiteness prepared by the present invention . 2. the preparation method of a kind of inorganic light-colored conductive powder as claimed in claim 1 is characterized in that: the mass ratio of nucleus body and deionized water in the described nucleus body dispersion liquid of step (1) is 1:4～ 1:20; the nucleus is one of potassium hexatitanate, potassium octatitanate, titanium dioxide, mica powder, silicon dioxide, attapulgite, sepiolite, halloysite and pyrophyllite. 3 . The preparation method of an inorganic light-colored conductive powder according to claim 1 , wherein the mass concentration of the tin-antimony hydrochloric acid mixed solution in the step (2) is 0.2-0.6 g/mL. 4 . 4. the preparation method of a kind of inorganic light-colored conductive powder as claimed in claim 1 is characterized in that: tin tetrachloride pentahydrate and three The mass ratio of antimony chloride is m(SnCl ₄ ·5H ₂ O):m(SbCl ₃ )=4-7:1, and the mass ratio of SnCl ₄ ·5H ₂ O to nuclei is 0.4-1.0:1. 5. the preparation method of a kind of inorganic light-colored conductive powder as claimed in claim 1 is characterized in that: in the tin-antimony hydrochloric acid mixed solution in the described step (4), tin tetrachloride pentahydrate and trichloride The mass ratio of antimony is m(SnCl ₄ 5H ₂ O):m(SbCl ₃ )=8～20:1; the mass ratio of powder to deionized water in the nucleus filter cake dispersion is 1:4～1: 20. The mass ratio of SnCl ₄ ·5H ₂ O to nuclei in the mixed solution of tin-antimony hydrochloric acid is 0.4-1.0:1. 6. the preparation method of a kind of inorganic light-colored conductive powder as claimed in claim 1 is characterized in that: the alkaline solution in described step (3) and step (4) is sodium hydroxide, ammoniacal liquor, hydrogen Potassium oxide solution, sodium bicarbonate, ammonium bicarbonate, ammonium carbonate, wherein the mass concentration of the alkaline solution is 1-4 mol/L. 7. The preparation method of an inorganic light-colored conductive powder as claimed in claim 1, characterized in that: in the step (5), the heat preservation solid-phase reaction temperature is 400-700°C, and the time is 0.5-2.5h .