Silicates based on alkaline earth metals, copper and optionally titanium, blue or purple pigments based on these silicates, processes for their preparation and their use

摘要

PCT No. PCT/FR95/00140 Sec. 371 Date Nov. 7, 1996 Sec. 102(e) Date Nov. 7, 1996 PCT Filed Feb. 6, 1995 PCT Pub. No. WO95/21791 PCT Pub. Date Aug. 17, 1995Alkaline-earth metal- and copper- and optionally titanium-based silicates in the form of agglomerates consisting either of monocrystalline grains or of aggregates themselves consisting of monocrystalline particles. These silicates are prepared by a process including the following stages: a silica sol or a silicate and optionally a titanium sol is mixed with salts of the other constituent elements of the silicate with the exception of oxygen; the mixture thus obtained is dried, preferably by spraying, and the product obtained is calcined. The silicates may be employed as colored pigments in plastics, paints, varnishes, rubbers, ceramics, glazes, papers, inks, cosmetic products, dyes and laminated coatings.