BLACK-COLORED PIGMENT PREPARATION METHOD Russian patent published in 2003 - IPC

FIELD: varnish-and-paint industry. SUBSTANCE: preparation of black pigment consists in crushing carbon-containing material, in particular anthracite with ash value no higher than 2-3%, sulfur content 0.5-0.8%, and carbon content 91.5-93.5%, followed by heat treatment for 10-30 min at 1200-1300 C. Density of resulting product is 1.8-1.9 g/cu.cm. EFFECT: improved spreading capacity and solubility in different solvents, improved homogeneity of pigment suspensions and increased their separation stability. 1 tbl, 8 ex