SU1213051A1 - Method of producing inorganic blue-green pigments - Google Patents

Description

The invention relates to the field of the production of inorganic pigment-1H1P, in particular blue-green pigments used for the preparation of artistic paints, paints for ceramic products and glass.

The purpose of the invention is to improve the vitality of inorganic blue-green pigments by increasing the dispersion and simplifying the process of their production.

Example 1. A nitrate solution of cobalt, aluminum, and chromium nitrates is prepared at a molar ratio of Co: A1: Cr 1: 1: 1 (Co:: A1 + Cg 1: 2) by mixing a solution of 1.85 kg of chromium nitrate 9- water in 2.8 l-water, a solution of 1.3 kg of cobalt 6-water nitrate in 2.5 water and a solution of 1.75 kg of aluminum nitrate 9-water in 2.5 l of water. The resulting solution is precipitated with a solution of sodium hydroxide (NaOH) prepared from 1.15 kg of NaOH in 5 l of water to a pH of 8.75. The precipitated hydroxide product is separated from the solution by centrifugation for 20 minutes, dried at 95 ° C, washed with water to obtain pure hydroxides, and then calcined at 950 ° C for 1.5 hours in air. The resulting pigment has a blue-green color, an opacity of 15 g / m and a particle size of 0.6 microns.

Example 2. The preparation of a pigment was carried out analogously to Example 1, but when the initial solution was precipitated with alkali to a pH of 8.2. The pigment contains an admixture of unreacted cobalt oxide of dark brown color, has an opacity of 42 g / m and a particle size of 1.9 microns.

Example 3. The preparation of a pigment was carried out analogously to example 1, but at a precipitation pH of 9.3. The resulting product also contains a mixture of cobalt, which impairs pigment color, a particle size of 0.7 µm and an opacity of 22 g / m.

Example .4. The preparation of the pigment is carried out as in Example 1, but by calcining at 1120 C. The pigment c. As a result, it has the following characteristics: blue-green color, opacity 26 g / M, particle size 2.2 microns.

Example 5. The preparation of pigment was carried out as in Example 1, but by calcining at 850 ° C. With such

temperature, the decomposition of the hydroxide product does not complete; the pigment contains the microheterogeneity of the chemical

composition.

Example 6. A nitrate solution is prepared at a molar ratio of Co: A1: 1: 2 by mixing a plant, a thief, 3.5 kg of 9-water aluminum nitrate in 5 liters of water and a solution of 1.3 kg of cobalt 6-water nitrate in 1 liter of water. The resulting solution is precipitated with alkali to a pH of 8.75, after which the precipitate is separated from the solution

centrifuge, dry and wash with water and calcined at. As a result, a blue-color pigment is obtained with a yield of 20 g / m and a particle size of 0.1 μm.

Example 7. Preparing aqueous solutions of 2.8 kg of chromium nitrate 9-water in 4.2 liters of water, 2.6 kg of aluminum nitrate 9-water in 3.8 liters of water, cobalt nitrate 6-water in 1 liter of water, they are mixed and the resulting solution at a molar ratio of Co:: A1: Cr 1.0: 1.5: 1.5 is precipitated with sodium hydroxide solution prepared with a solution of 1.58 kg of alkali in 7 liters of water to a pH of 8.75.

The precipitated hydroxide product is separated from the solution, dried, washed with water, and then calcined at. The resulting pigment has a blue-green color, ukrishistos 15 g / m. And a particle size of 0.1 microns. I Example 8. A nitric acid aqueous solution is obtained with a molar

Co: A1 ratio, 0: 0.9: 0.9. The pigment obtained from it as in Example 7 contains an admixture of cobalt, a yield of 19 g / m, and a particle size of 0.1 μm.

Example 9. A pigment is prepared, as in Example 7, from a solution with a molar ratio of Co: A1: Cr 1.0:: 1.75: 1.75. The pigment has a green color, ukrishistosti 15 g / m, size

particles of 0.1 microns.

Pigment production under conditions

The proposed method of cobalt nitrate, aluminum and chromium provide

It is obtained in a highly dispersed form with a particle size of 0.1–1.0 μm of a spinel structure with a gamma coverage. .

31213051 I

Simplification of the process of obtaining pigment — the disaggregation of pigment and cops according to the proposed method of reducing the calcination temperature to is provided by eliminating 870-1100 C.

Compiled by L.Romantseva Editor A.Sabo Tehred T.Tulik Proofreader O.Lugova

Order 726/36 Edition 644 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Branch PPP Patent, Uzhgorod, Proektna St., 4

Claims (3)

1. METHOD FOR PRODUCING INORGANIC PIGMENTS BLUE-GREEN. COLORS from a solution of cobalt, aluminum and chromium salts, including precipitation with an alkaline agent, separation of the precipitated hydroxide product by centrifugation, washing and drying it, and subsequent calcination, characterized in that, in order to improve the hiding power of the target pigment by increasing the dispersion and simplifying the process, in As the initial salt solution, a nitric acid solution is taken at a molar ratio of cobalt and chromium or the sum of aluminum and chromium is 1: 2-3 and its deposition is carried out at pH 8.5-9.0. 2. The method according to claim 1, characterized in that the calcined precipitated hydroxide product is carried out at 870-1100 ° C for 1-2 hours 3. The method according to claim 1, with the fact that aluminum and chromium in the initial solution are taken in an equimolar ratio.