COMPOSITION A BASE D'UN SULFURE DE TERRE RARE A STABILITE CHIMIQUE AMELIOREE, SON PROCEDE DE PREPARATION ET SON UTILISATION COMME PIGMENT

摘要

The present invention concerns a composition based on a rare earth sulphide with improved stability, a process for its preparation and to use as a colouring pigment. The composition of the invention is characterized in that it contains a support based on a rare earth sulphide and a layer based on at least one salt of said rare earth sulphide, a hydroxide, an oxide of said rare earth or an oxy and/or hydroxy derivative thereof, the salt, hydroxide, oxide and derivative being insoluble in water and/or in alcohols. Said composition is obtained by acid attack of the surface of said support optionally followed by neutralisation.