FINE PARTICLE-TYPE COBALT BLUE-BASED PIGMENT WITH RED TONE AND ITS PREPARATION

摘要

PROBLEM TO BE SOLVED: To provide a fine particle-type cobalt blue-based pigment which is transparent and which has good dispersibility, high coloring power and redder tone and also provide a method of preparing the pigment without generation of a nitrogen source such as urea. ;SOLUTION: This fine particle-type cobalt blue-based pigment has a specific surface area of 40-60 m2/g by the BET method and comprises aluminum oxide and cobalt oxide and contains 0.2-1.0 wt.% of a phosphorus compound in terms of phosphorus. A preparation method of the pigment is to form precipitates of hydroxides and/or carbonates of aluminum and cobalt in succession in two steps in the absence or presence of the phosphorus compound and to calcine the precipitates.;COPYRIGHT: (C)2000,JPO