MULTIPLE OXIDE GREEN PIGMENT AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To produce a chromium-free multiple oxide green pigment similar in hue and characteristics to a chromium-contg. multiple oxide green pigment. SOLUTION: The hydroxides or carbonates of aluminum and titanium are precipitated from an aq.soln. of a mixture of aluminum and titanium salts and an aq. alkali soln. to prepare a precipitate slurry. The hydroxide or carbonate of cobalt is precipitated in the slurry from an aq. cobalt salt soln. and an aq. alkali soln. The coexistent hydroxides or carbonates are heated, aged, separated by filtration, washed and fired to produce the objective multiple oxide green pigment.