CN100378870C - A kind of nano oxide conductive powder and preparation method thereof - Google Patents

Abstract

The present invention relates to a method for preparing nanometer oxide conductive powder, which belongs to the technical field of a conductive material. The conductive powder is nanometer oxide conductive powder of which the surface is wrapped by stannum oxide mixing antimony. A prepared acidic solution containing stannum and the antimony and a precipitating agent of alkaline liquor are simultaneously dropped in stirred oxide slurry by a liquid distributor, the flow capacity of the acidic solution and the alkaline liquor is regulated to control the pH value of a system between 1.5 and 5 and carry out a smooth reaction, and the hydrolysate of the stannum and the antimony is co-deposited on the particle surface of oxide powder; after the standing operation of the coating product of the deposition is carried out, light-colored oxide conductive powder is obtained by washing, filtration, drying, calcination and pulverization. The present invention has the advantages of large yield, high automation degree, stable quality, low cost, etc., and the obtained product has the advantages of low antimony content, light-colored powder, low resistance, easy dispersion, heat resistance, corrosion resistance, high stability and good wave penetrating property; permanent conductive additive agents with various colours, which are close to white, etc. The present invention has wide application prospect.

Description

A kind of nano oxide conductive powder and preparation method thereof

technical field

The invention relates to a nano-oxide conductive powder and a preparation method thereof, belonging to the technical field of conductive materials.

Background technique

Conductive powder is widely used in petroleum, chemical industry, electronics, communication, automobile, papermaking, textile, ceramics, aerospace and other industrial sectors and people's daily life. When added to paint, ink, plastic, rubber, fiber, it can be made Into anti-static products.

Traditionally commonly used conductive powders include metal powder, carbon powder, organic powder and metal oxide powder. Organic conductive fillers are not resistant to high temperature, corrosion, water resistance, oil resistance, poor durability and unstable antistatic properties. They can only be used in environments with relative humidity greater than 60%, and the surface resistivity is generally greater than 100 megohm; black conductive graphite , the dispersion of carbon black is poor, the color of the product is dark, it is not easy to color, and the production and use are easy to stain the working environment; silver, aluminum, copper, nickel and other metal powders are easy to oxidize, have poor corrosion resistance, and have the defects of interfering with radio waves. deep.

The research on light-colored conductive powder is mainly concentrated in Japan and Europe, and there are also some in China. Japanese Patent No. 63-233016, its rights and characteristic requirements are needle-shaped titanium dioxide, the length is 1-10um, and the aspect ratio is greater than three, and the pre-acid-alkali treatment of titanium dioxide is too cumbersome and the cost is high. Moreover, Sb ₂ O ₃ /SnO ₂ mass ratio is as high as 21.87%, and the antimony content determines the depth of the powder color. British Patent No.2252551 discloses a preparation method of silicon dioxide and antimony-containing tin oxide conductive powder. In this method, silicon dioxide is used to coat titanium dioxide to form an intermediate layer, and then the hydrolysis product of tin and antimony is deposited under controlled conditions. It is obtained by washing the surface of the particles, drying and calcining. The powder obtained by this method has a high resistance (300-400Ω.cm), and there are too many steps. The claim and feature of domestic patent 03115830.7 is that the nitrate solution of tin and antimony and ammonia water are added into distilled water in parallel, and the precipitate is heat-treated to obtain conductive powder. Although the conductivity is good, the amount of tin and antimony is large, the color is too dark, and the cost higher. The claims and features of Chinese patent 0111881.X are that in the production, the solution of antimony salt and tin salt is added to the slurry of titanium dioxide respectively, or the antimony salt and tin salt are mixed and then added to the titanium dioxide slurry, and there is no online constant control of pH value in the middle. The pH value of the end point is 7～13, and the strong alkaline environment will definitely cause the non-co-precipitation of antimony and tin, the doping effect of antimony is affected, and the antimony content is too high (in its embodiment, the mass ratio of Sb ₂ O ₃ /SnO ₂ is as high as 25%).

The above existing inventions have the problem of high resistivity of the conductive powder, the amount of doping element antimony used is large, the cost is high, and the color of the conductive powder is likely to be dark and the whiteness is insufficient. In addition, the above-mentioned method is suitable for the preparation of conductive powder with a particle size of titanium oxide powder larger than microns, while nano-powder needs to be fully dispersed before coating.

Contents of the invention

The object of the present invention is to overcome the deficiencies of the prior art, and provide a light-colored conductive powder of nano oxide with excellent whiteness and conductivity and its industrial production method.

The technical scheme of the present invention is: the nano-oxide conductive powder is a nano-oxide conductive powder coated with antimony-doped tin oxide on the surface, and the nano-oxide is a stable nano-metal oxide or a mixture of multiple nano-metal oxides , the nano metal oxide with stable performance can be nano TiO ₂ , SiO ₂ , Al ₂ O ₃ powder, etc. The volume resistance of the conductive powder is 10-400Ω.cm, the whiteness index is L=70-86, the mass ratio of Sb ₂ O ₃ to SnO ₂ is 0.03-0.15, and the mass ratio of SnO ₂ to oxide carrier is 0.1-0.3 .

The preparation method of the nano oxide conductive powder comprises the following steps in sequence:

1.1 A metal oxide or a mixture of multiple metal oxides with an average particle size of less than 200nm and stable performance, such as TiO ₂ or SiO ₂ , Al ₂ O ₃ , etc., or a mixture of two or more of them, in the range of 50 to The amount of 200g/L is stirred with deionized water or distilled water in a heatable reactor, and polyphosphoric acid or polyphosphate is added as a dispersant to disperse the oxide powder evenly. Polyphosphoric acid or polyphosphate is polyphosphoric acid with n≥3 and its various salts, such as lithium, sodium, potassium, ammonium salt, etc., and the molar concentration of it is 0.001-0.02mol/L. The dispersant can eliminate the agglomeration of nano-oxide powder, make the tin oxide coating layer more uniform, and cover the surface of the oxide primary particles densely.

1.2 Prepare an acidic mixed solution composed of hydrochloric acid, nitrate, or sulfate of tin and antimony, the concentration of tin in the acidic mixed solution is 0.1-2mol/L, and the mass ratio of Sb ₂ O ₃ to SnO ₂ is 0.03-0.15 . The preparation of the acidic mixed solution is to add nitric acid or sulfuric acid, or hydrochloric acid dropwise into the mixture of tin powder and antimony powder at a temperature of 30-90°C, the equivalent of nitric acid or sulfuric acid, or hydrochloric acid is 2-10N, or tin salt and Antimony salts are dissolved in 2-8N nitric acid or sulfuric acid, or hydrochloric acid. The tin salt is one or more of tin sulfate, tin chloride, stannous chloride, tin nitrate or tin salt with crystal water, and the antimony salt is one or more of antimony sulfate, antimony nitrate or antimony chloride kind. The chelating agent tartaric acid or tartrate, which promotes the co-deposition of antimony and tin, can also be added to the acidic mixed solution. The molar ratio of tartrate and antimony of the added chelating agent is 1 to 6, and the chelating agent can make the antimony energy more effective during co-precipitation. The doping of tin on the crystal lattice significantly reduces the amount of antimony and makes the resulting nano-oxide conductive powder lighter in color.

1.3 The acidic mixed solution and the alkali precipitation agent are dropped into the reactor containing the uniformly dispersed oxide powder carrier and kept stirring through the liquid distributor with fine droplets at the same time, and the flow rate of the acid and alkali is controlled. The system reacts stably at a temperature of 30-90°C and maintains a pH value in the range of 1.5-5, so that tin and antimony are hydrolyzed and co-deposited, and evenly coated on the surface of oxide powder particles. The liquid distributor is a filter with pores, the diameter of the pores is 1-5mm, and the interval is 1-5cm (selected according to actual needs); the lye precipitant is ammonia water, ammonium carbonate, ammonium bicarbonate, sodium bicarbonate, carbonic acid One or more mixtures of sodium and sodium hydroxide, the equivalent of which is 2-10N; the flow adjustment of acid and lye can use the online PH value control system, and the mixed acid and lye can be adjusted through the quantitative adjustment switch or The solenoid valve is added to the liquid distributor, the pH probe is inserted into the reactor to collect the signal, the pH meter is compared with the set pH value, and the quantitative adjustment switch or solenoid valve is feedback controlled to control the amount of mixed acid and lye; Online pH value control reaction time is 0.5-4 hours.

1.4 Let the precipitated coated product stand for more than 0.5 hours, then wash, filter, dry, calcinate, and pulverize to obtain light-colored oxide conductive powder. The calcination temperature is 350-650°C and the time is 1-3 hours; it can be filtered 2-5 times, drying can be carried out at 80-120°C.

The stable nano-metal oxide powder (carrier) can also be mica, barite, calcium carbonate and other light-colored mineral powders, and one or more of them can be used as a carrier for the deposition of antimony-doped tin oxide.

In the present invention, through in-depth research on the conductivity of antimony-doped tin dioxide and its Zeta potential diagram, and the Zeta potential diagram of oxide carrier powder, polyphosphoric acid or polyphosphate is used as a dispersant for oxides to make the oxides before coating Nanopowder is dispersed into individual particles, so that the conductive layer can be coated on the surface of individual particles, and a powder with low resistivity is obtained; tartaric acid and its salts are used as antimony chelating agents to control the co-precipitation process of antimony and tin, so that antimony can More effective doping on the tin lattice, reducing the amount of antimony; at the same time, using precise online control method to control the process parameters in the most favorable narrow range, so that the antimony-doped tin dioxide is more firmly and uniformly covered Coated on the surface of highly dispersed titanium dioxide or other stable oxides, a film is formed, and the thickness of the film is controllable, and the conductivity is also adjustable. Therefore, the method has the advantages of large output, high degree of automation, very stable _quality , and low cost; the product obtained by the method has low antimony content ( _Sb2O3 / _SnO2 mass ratio is less than 15%), light powder color, The advantage of low resistance has broad industrial prospects.

The invention also has the characteristics of easy dispersion, heat resistance, high stability, corrosion resistance, good wave permeability, good conductivity, etc., and can be easily modulated into permanent conductive additives of various colors such as near white.

Description of drawings

The present invention will be further described below in conjunction with drawings and embodiments.

Fig. 1 is a process flow diagram of the present invention:

Fig. 2 is the titanium dioxide conductive powder XRD spectrum of embodiment 3 of the present invention;

Fig. 3 is the titanium dioxide conductive powder XRD spectrum of embodiment 5 of the present invention;

Fig. 4 is a TEM image of the titanium dioxide conductive powder in Example 5 of the present invention.

Detailed ways

Embodiment 1: The nano-oxide conductive powder is nano- _TiO2 conductive powder coated with antimony-doped tin oxide on the surface, its volume resistance is 400Ω.cm, and the whiteness index is L= _84.2 , the quality of _Sb2O3 and _SnO2 The ratio is 0.03, and the mass ratio of SnO ₂ to TiO ₂ is 0.2.

The preparation method of the nano oxide conductive powder comprises the following steps in sequence:

1.1 Add 10g of TiO ₂ with an average particle size of 130nm into 200mL of distilled water in the reactor, then add polyphosphoric acid with a molar concentration of 0.001mol/L and stir to make the TiO ₂ uniformly dispersed.

1.2 Dissolve 4.653g SnCl ₄ 5H2O and 0.094g SbCl ₃ in 60ml 8N hydrochloric acid at 60°C to obtain an acidic mixed solution (the concentration of tin is 0.22mol/L, the mass of Sb ₂ O ₃ and SnO ₂ ratio is 0.03);

1.3 Put the acidic mixed solution and the ammonia water precipitant with an equivalent of 2N, through a liquid distributor with a micropore diameter of 1 mm and an interval of 1 cm, and drop them into the reactor filled with uniformly dispersed TiO ₂ at the same time and kept stirring , adjust the flow of acid and lye through the online pH value control system, and control the system to maintain a pH value of 1.5 at a temperature of 60 ° C for 1 hour to react stably, so that tin and antimony can be hydrolyzed and co-deposited, and evenly coated on TiO ₂ On the surface. The online PH value control system is to add the mixed acid and lye into the liquid distributor through a quantitative adjustment switch or a solenoid valve, insert a PH probe into the reactor to collect signals, compare with the set PH value through the PH meter, and feedback control Quantitative adjustment switch or solenoid valve to control the amount of mixed acid and lye added.

1.4 Let the precipitated coated product stand for 0.5 hours, then wash and filter 5 times (so that no chloride ions can be detected in the silver chloride solution), dry it at 80°C, calcinate it at 650°C for 1 hour, and then pulverize it. Obtain light-colored _TiO2 conductive powder.

Embodiment 2: The nano-oxide conductive powder is nano- _SiO2 conductive powder coated with antimony-doped tin oxide on the surface, its volume resistance is 180Ω.cm, and the whiteness index is the mass of L= _71.3 , _Sb2O3 and _SnO2 The ratio is 0.15, and the mass ratio of SnO ₂ to SiO ₂ is 0.3.

The preparation method of the nano oxide conductive powder comprises the following steps in sequence:

1.1 Add 40g of SiO ₂ with an average particle size of 200nm into 200mL of distilled water in the reactor, then add sodium polyphosphate with a molar concentration of 0.01mol/L and stir, so that SiO ₂ is evenly dispersed.

1.2 Dissolve 27.92g SnCl ₄ ·H2O and 2.82g SbCl ₃ in 70ml 2N hydrochloric acid at 30°C to obtain an acidic mixed solution (the concentration of tin is 1.138mol/L, the mass of Sb ₂ O ₃ and SnO ₂ ratio is 0.15);

1.3 Put the acidic mixed solution and the ammonia water precipitant with an equivalent of 10N, through a liquid distributor with a micropore diameter of 5mm and an interval of 5cm, drop them into the reactor filled with uniformly dispersed _SiO2 and keep stirring , through the online pH value control system, adjust the flow of acid and lye, control the system at a temperature of 30 ° C, maintain a pH value of 5 and react for 4 hours, so that tin and antimony are hydrolyzed and co-deposited, evenly coated on SiO ₂ On the surface. The online PH value control system is to add the mixed acid and lye into the liquid distributor through a quantitative adjustment switch or a solenoid valve, insert a PH probe into the reactor to collect signals, compare with the set PH value through the PH meter, and feedback control Quantitative adjustment switch or solenoid valve to control the amount of mixed acid and lye added.

1.4 Let the precipitated coated product stand for 3 hours, then wash and filter twice (so that no chloride ions can be detected in the silver chloride solution), dry it at 120°C, calcinate it at 350°C for 3 hours, and then pulverize it. Obtain light-colored _SiO2 conductive powder.

Embodiment 3: this nano-oxide conductive powder is nano- _TiO2 conductive powder coated with antimony-doped tin oxide on the surface, its volume resistance is 28Ω.cm, and the whiteness index is L= _84.5 , _Sb2O3 and _SnO2 quality The ratio is 0.1, and the mass ratio of SnO ₂ to TiO ₂ is 0.25.

The preparation method of the nano oxide conductive powder comprises the following steps in sequence:

1.1 Add 1165g of TiO ₂ with an average particle size of 50nm into 11.65L of distilled water in the reactor, and then add potassium polyphosphate with a molar concentration of 0.002mol/L and stir to make the TiO ₂ uniformly dispersed.

1.2 Dissolve 677.5g SnCl ₄ 5H2O and 45.58g SbCl ₃ in 6.991 liters of 6N hydrochloric acid at a temperature of 40°C to obtain an acidic mixed solution (the concentration of tin is 0.276mol/L, the concentration of Sb ₂ O ₃ and SnO ₂ Mass ratio is 0.1), add a certain amount of chelating agent tartaric acid in acid mixed solution again, make the mol ratio of tartrate radical and antimony be 2;

1.3 Put the acidic mixed solution and the ammonia water precipitant with an equivalent of 6N into the reactor filled with uniformly dispersed _TiO2 and keep stirring through the liquid distributor with a micropore diameter of 2mm and an interval of 2cm at the same time. , adjust the flow of acid and lye through the online pH value control system, and control the system to maintain a pH value of 2.2 at a temperature of 40 ° C for 1.5 hours to react smoothly, so that tin and antimony are hydrolyzed and co-deposited, and evenly coated on TiO ₂ On the surface. The online PH value control system is to add the mixed acid and lye into the liquid distributor through a quantitative adjustment switch or a solenoid valve, insert a PH probe into the reactor to collect signals, compare with the set PH value through the PH meter, and feedback control Quantitative adjustment switch or solenoid valve to control the amount of mixed acid and lye added.

1.4 Let the precipitated coated product stand for 3 hours, then wash and filter 3 times (so that no chloride ions can be detected in the silver chloride solution), dry it at 100°C, calcinate it at 500°C for 1.5 hours, and then pulverize it. Obtain light-colored _TiO2 conductive powder.

Embodiment 4: The nano oxide conductive powder is nano-TiO ₂ and SiO ₂ conductive powder coated with antimony-doped tin oxide on the surface, its volume resistance is 25Ω.cm, and the whiteness index is L=81.2, Sb ₂ O ₃ and SnO The mass ratio of ₂ is 0.05, and the mass ratio of SnO ₂ to TiO ₂ and SiO ₂ mixed oxides is 0.2.

The preparation method of the nano oxide conductive powder comprises the following steps in sequence:

1.1 Add 665g of TiO ₂ with an average particle size of 130nm and 500g of SiO ₂ with an average particle size of less than 200nm into 11.65L of distilled water in the reactor, then add sodium polyphosphate with a molar concentration of 0.002mol/L and stir to make the mixed oxide Disperse evenly.

1.2 Dissolve 542.03g SnCl ₄ ·H2O and 18.23g SbCl ₃ in 3 liters of 6N hydrochloric acid at a temperature of 45°C to obtain an acidic mixed solution (the concentration of tin is 0.52mol/L, the concentration of Sb ₂ O ₃ and SnO ₂ Mass ratio is 0.05), then add a certain amount of chelating agent tartaric acid in acid mixed solution, make the mol ratio of tartrate radical and antimony be 4;

1.3 Put the acidic mixed solution and the ammonia water precipitant with an equivalent of 7N, through a liquid distributor with a micropore diameter of 3 mm and an interval of 3 cm, drop them into the uniformly dispersed TiO ₂ and SiO ₂ at the same time and keep stirring. In the reactor, through the online pH value control system, the flow rate of acid and lye is adjusted, and the control system maintains a pH value of 3.5 at a temperature of 50 ° C for 1.2 hours to react stably, so that tin and antimony are hydrolyzed and co-deposited and evenly coated on mixed oxide surfaces. The online PH value control system is to add the mixed acid and lye into the liquid distributor through a quantitative adjustment switch or a solenoid valve, insert a PH probe into the reactor to collect signals, compare with the set PH value through the PH meter, and feedback control Quantitative adjustment switch or solenoid valve to control the amount of mixed acid and lye added.

1.4 Let the precipitated coated product stand for 2 hours, then wash and filter 4 times (so that no chloride ions can be detected in the silver chloride solution), dry it at 80°C, calcinate it at 600°C for 1.2 hours, and then pulverize it. Obtain light-colored oxide conductive powder.

Example 5: The nano-oxide conductive powder is nano-TiO ₂ conductive powder coated with SnO ₂ and Sb ₂ O ₃ co-deposits on the surface, its volume resistance is 250Ω.cm, and the whiteness index is L=86, Sb ₂ O 3 The mass ratio of ₃ to SnO ₂ is 0.05, and the mass ratio of SnO ₂ to TiO ₂ is 0.25.

The preparation method of the nano oxide conductive powder comprises the following steps in sequence:

1.1 Add 20g of TiO ₂ with an average particle size of 50nm into 200mL of distilled water in the reactor, then add sodium polyphosphate with a molar concentration of 0.001mol/L and stir to make the TiO ₂ uniformly dispersed.

1.2 Dissolve 11.63g SnCl ₄ ·H2O and 0.39g SbCl ₃ in 30ml 8N hydrochloric acid at 75°C to obtain an acidic mixed solution (the concentration of tin is 1.1mol/L, the mass of Sb ₂ O ₃ and SnO ₂ ratio is 0.05);

1.3 Put the acidic mixed solution and the ammonia water precipitant with an equivalent of 8N into the reactor filled with uniformly dispersed _TiO2 and keep stirring through the liquid distributor with a micropore diameter of 3mm and an interval of 2.5cm at the same time. Inside, through the online pH value control system, the flow rate of acid and alkali is adjusted, and the control system maintains a pH value of 1.9 at a temperature of 75 ° C for 1 hour to react stably, so that tin and antimony are hydrolyzed and co-deposited, and evenly coated on TiO ₂ on the surface. The online PH value control system is to add the mixed acid and lye into the liquid distributor through a quantitative adjustment switch or a solenoid valve, insert a PH probe into the reactor to collect signals, compare with the set PH value through the PH meter, and feedback control Quantitative adjustment switch or solenoid valve to control the amount of mixed acid and lye added.

1.4 Let the precipitated coated product stand for 2.5 hours, then wash and filter 4 times (so that the silver chloride solution cannot detect chloride ions), dry it at 60°C, calcinate it at 400°C for 2 hours, and then pulverize it. Obtain light-colored _TiO2 conductive powder.

Embodiment 6: The nano-oxide conductive powder is nano Al ₂ O ₃ conductive powder coated with SnO ₂ and Sb ₂ O ₃ co-deposits on the surface, its volume resistance is 200Ω.cm, and the whiteness index is L=85, Sb The mass ratio of ₂ O ₃ to SnO ₂ is 0.1, and the mass ratio of SnO ₂ to Al ₂ O ₃ is 0.1.

The preparation method of the nano oxide conductive powder comprises the following steps in sequence:

1.1 Add 100g of Al ₂ O ₃ with an average particle size of 100nm to 1L of distilled water in the reactor, then add sodium polyphosphate with a molar concentration of 0.015mol/L and stir to make the Al ₂ O ₃ evenly dispersed.

1.2 At a temperature of 90°C, add 10N sulfuric acid dropwise to a mixture of 7.88g tin powder and 0.835g antimony powder to obtain an acidic mixed solution (the concentration of tin is 2mol/L, and the mass ratio of Sb ₂ O ₃ to SnO ₂ is 0.04), add a certain amount of chelating agent tartaric acid in acid mixed solution, make the mol ratio of tartrate radical and antimony be 6;

1.3 Mix the precipitant with the acidic mixed solution, ammonia water and ammonium carbonate with an equivalent of 10N, and drop them into the evenly dispersed Al ₂ O ₃ at the same time through a liquid distributor with a micropore diameter of 1.5 mm and an interval of 1 cm. And keep stirring in the reactor, adjust the flow of acid and lye through the online pH value control system, control the system at a temperature of 90 ° C, maintain a pH value of 5 and react stably for 1 hour, so that tin and antimony are hydrolyzed and co-deposition, uniformly coated on the surface of Al ₂ O ₃ . The online PH value control system is to add the mixed acid and lye into the liquid distributor through a quantitative adjustment switch or a solenoid valve, insert a PH probe into the reactor to collect signals, compare with the set PH value through the PH meter, and feedback control Quantitative adjustment switch or solenoid valve to control the amount of mixed acid and lye added.

1.4 Let the precipitated coated product stand for 2 hours, then wash and filter 5 times (so that sulfate ions cannot be detected in the washing liquid), dry at 90°C, calcinate at 500°C for 1.5 hours, and then pulverize , to obtain light-colored oxide conductive powder.

Example 7: The nano-oxide conductive powder is nano-TiO ₂ conductive powder coated with SnO ₂ and Sb ₂ O ₃ co-deposits on the surface, its volume resistance is 10Ω.cm, and the whiteness index is L=83.5, Sb ₂ O 3 The mass ratio of ₃ to SnO ₂ is 0.06, and the mass ratio of SnO ₂ to TiO ₂ is 0.3.

The preparation method of the nano oxide conductive powder comprises the following steps in sequence:

1.1 Add 100g of TiO ₂ with an average particle size of 200nm into 1L of distilled water in the reactor, and then add lithium polyphosphate with a molar concentration of 0.015mol/L and stir to make the TiO ₂ uniformly dispersed.

1.2 At a temperature of 30°C, add 2N sulfuric acid and nitric acid dropwise into a mixture of 23.62g tin powder and 1.5g antimony powder to obtain an acidic mixed solution (the concentration of tin is 0.1mol/L, the concentration of Sb ₂ O ₃ and SnO ₂ Mass ratio is 0.06), add a certain amount of chelating agent tartaric acid in acid mixed solution, make the mol ratio of tartrate radical and antimony be 1;

1.3 Mix the acidic mixed solution with the equivalent of 2N ammonium bicarbonate and sodium bicarbonate as a precipitant, and drop them into the uniformly dispersed TiO ₂ at the same time through a liquid distributor with a micropore diameter of 4 mm and an interval of 4 cm. And keep stirring in the reactor, adjust the flow of acid and lye through the online pH value control system, control the system at a temperature of 30 ° C, maintain a pH value of 1.5 and react stably for 4 hours, so that tin and antimony are hydrolyzed and co-deposition, uniformly coated on the _TiO2 surface. The online PH value control system is to add the mixed acid and lye into the liquid distributor through a quantitative adjustment switch or a solenoid valve, insert a PH probe into the reactor to collect signals, compare with the set PH value through the PH meter, and feedback control Quantitative adjustment switch or solenoid valve to control the amount of mixed acid and lye added.

1.4 Let the precipitated coated product stand for 3 hours, then wash and filter twice (so that sulfuric acid and nitrate ions cannot be detected in the washing liquid), dry it at 80°C, and calcinate it at 550°C for 1.8 hours, then After crushing, a light-colored _TiO2 conductive powder is obtained.

The resistance measurement of the light-colored titanium dioxide conductive powder produced by the present invention is to pack 5 grams of conductive powder into a PVC plastic pipe, apply a pressure of 10Mpa at both ends to measure the volume resistance R, and calculate by formula=R(A/L) to obtain . In the formula, A is the cross-sectional area of the plastic pipe, and L is the height of the conductive powder block after compression. The whiteness measurement is carried out on a whiteness meter according to GB/T5950-1996.

Claims (8)

1. nano-oxide conducting powder, it is characterized in that this conducting powder is the nano-oxide conducting powder that is coated with antimony doped tin oxide, nano-oxide is a kind of nano-metal-oxide of stable performance or the mixture of multiple nano-metal-oxide, the nano-metal-oxide of stable performance can be nano TiO 2, SiO2, Al2O3 powder, the volume resistance of conducting powder is 10-400 Ω cm, the whiteness index is L=70-86, the mass ratio of Sb2O3 and SnO2 is 0.03-0.15, and the mass ratio of SnO2 and oxide carrier is 0.1-0.3.

2. the preparation method of the described nano-oxide conducting powder of claim 1 is characterized in that may further comprise the steps successively:

1.1 with particle mean size less than a kind of metal oxide of 200nm and stable performance or the mixture carrier of multiple metal oxide, amount by 50-200g/L stirs in the reactor that can heat with deionized water or distilled water, and add polyphosphoric acid or polyphosphate is made dispersant, oxide powder is uniformly dispersed;

1.2 the acidic mixed solution that preparation is made up of the hydrochloric acid of tin, antimony or nitrate or sulfate, the concentration of tin is 0.1-2mol/L in this acidic mixed solution, and the mass ratio of Sb2O3 and SnO2 is 0.03-0.15;

1.3 with acidic mixed solution and alkali lye precipitation reagent, splash in the reactor that fills homodisperse oxide powder and keep stirring simultaneously with tiny drop by liquid distribution trough, by regulating the flow of acid, alkali lye, the hierarchy of control under 30-90 ℃ of temperature, keep pH value smooth reaction in the 1.5-5 scope, make the hydrolysis of tin antimony and produce codeposition, be coated on the oxidate powder surface equably;

1.4 the coating product that will precipitate left standstill more than 0.5 hour, washed then, filter, and drying, calcining is pulverized, and obtains light oxide conductive powder, and calcining heat is that 350-650 ℃, time are 1-3 hour.

3. the preparation method of nano-oxide conducting powder as claimed in claim 2 is characterized in that polyphosphoric acid or polyphosphate are the polyphosphoric acid acid and the various salt thereof of n 〉=3, and the molar concentration of its adding is 0.001-0.02mol/L.

4. the preparation method of nano-oxide conducting powder as claimed in claim 2, the preparation that it is characterized in that acidic mixed solution is under 30-90 ℃ of temperature, nitric acid or sulfuric acid or hydrochloric acid are added dropwise in the mixture of glass putty and antimony powder, and the equivalent of nitric acid or sulfuric acid or hydrochloric acid is 2-10N; Or pink salt and antimonic salt be dissolved in the nitric acid or sulfuric acid or hydrochloric acid of 2-8N.

5. as the preparation method of claim 2 or 3 described nano-oxide conducting powders, it is characterized in that pink salt is one or more in STANNOUS SULPHATE CRYSTALLINE, stannic chloride, stannous chloride, nitric acid tin or the pink salt of being with the crystallization water, antimonic salt is one or more in antimony sulfate, nitric acid antimony or the antimony chloride.

6. as the preparation method of claim 2 or 3 described nano-oxide conducting powders, it is characterized in that adding chelating agent tartaric acid or the tartrate that promotes antimony, tin codeposition in acidic mixed solution, the tartrate anion of the chelating agent of adding and the mol ratio of antimony are 1-6.

7. the preparation method of nano-oxide conducting powder as claimed in claim 2 is characterized in that the alkali lye precipitation reagent is one or more the mixed liquor in ammoniacal liquor, carbonic acid ammonia, ammonium hydrogencarbonate, sodium acid carbonate, sodium carbonate, the NaOH, and its equivalent is 2-10N.

8. the preparation method of nano-oxide conducting powder as claimed in claim 2, the Flow-rate adjustment that it is characterized in that acid, alkali lye can adopt online pH value control system, mix acid liquor and alkali lye are added liquid distribution trough by quantitative by-pass cock or electromagnetically operated valve, in reactor, insert PH probe acquired signal, by PH meter with set pH value and compare, and quantitative by-pass cock of FEEDBACK CONTROL or electromagnetically operated valve, the addition of control mix acid liquor and alkali lye; The online reaction time is 0.5-4 hour.

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