BISMUTH OXYCHLORIDE GLOSSY PIGMENT HAVING IMPROVED WEATHER FASTNESS AND PREPARATION THEREOF

摘要

PURPOSE: To obtain a glossy pigment composition which is excellent in light stability and useful for toiletry, etc., by reacting a cerium salt solution with a bismuth oxychloride pigment suspension under specified conditions. ;CONSTITUTION: The solution of a cerium salt such as cerium hydroxide is added into the first suspension of a bismuth oxychloride pigment to prepare the second suspension containing the bismuth oxychloride pigment and cerium hydroxide. In this process, the pH value of the second suspension is kept at a pH value or below where cerium hydroxide is precipitated, next the pH value of the second suspension is increased to at least a pH value where cerium hydroxide is precipitated to precipitate the cerium hydroxide, which is coated with the bismuth oxychloride pigment to obtain an intended glossy pigment composition. The amount of the cerium compound for the coating is preferably 1-7.5 wt.% of the total weight of the pigment.;COPYRIGHT: (C)1993,JPO