USE AS A COLORING PIGMENT OF A RARE EARTH SULFIDE OF BETA FORM AND PROCESS FOR THE PREPARATION THEREOF

摘要

The invention concerns the use of a beta rare earth sulphide as colouring pigment and its method of preparation. A beta rare earth sulphide is used, the rare earth being lanthanum, cerium, praseodymium, samarium or neodymium. The sulphide consists of whole crystallites, said crystallites forming medium-sized aggregates of not more than 1.5 mu m. The method of preparation of this rare earth sulphide is characterised in that a rare earth compound is reacted with at least one sulphidising gas selected among hydrogen sulphide or carbon sulphide. The pigment can be part of compositions of the following types: plastic, paint, surface coating, rubber, ceramic, glazing, paper, ink, cosmetic products, dyes, leather, laminated coating or other types of compositions with a base of at least one mineral binder or obtained therefrom.