INORGANIC PIGMENT ON THE BASE OF SULFIDE OF METAL AND METHOD FOR ITS PRODUCTION Russian patent published in 1998 - IPC

FIELD: paint and varnish production; production of plastics, ceramics; building materials production. SUBSTANCE: pigments on the base of sulfides having formula (AS)_x(A¹BS₂)_1-x, where A is rare-earth metal, A¹ is alkaline metal, B is rare-earth metal having atomic number 57-71 or B is yttrium if x=0.1-0.95 are proposed. If A is calcium or strontium, A¹ is sodium or potassium, B is cerium and x=0.4-0.95, then desired pigments are colored from dark-red to yellow. Applying of protective transparent layer of metal oxide on the surface of sulfide particles is proposed to carry out together with feeding of fluorine ions into surface layer to increase thermal resistance and to improve coloring respectively. Proposed pigments are prepared by interaction of carbonates of alkaline-earth metal and alkaline metal with oxide of rare-earth metal and with sulfur-containing agent which takes place at 600-1200 C. Applying of layer of metal oxide and fluorination are carried out by commonly used technique. Proposed pigments are ecologically safety, they have high chemical and thermal resistance. EFFECT: improved quality of desired product, improved efficiency of the method. 14 cl