Colored aluminum pigments having a color pigment adhered closely, uniformly and firmly thereto through inorganic acid radical adsorbed on the surface of the aluminum pigment are suitable for use in paints, inks and molded resins. Color fading, poor chroma and processing complications commonly encountered with conventional aluminum pigments are avoided.

In order to provide a color metallic pigment capable of implementing diverse colors, excellent in finished appearance and weather resistance and manufacturable by a safe and simple manufacturing method, a color metallic pigment comprising metal particles and a single-layer or multilayer coat covering the surface of each metal particle characterized in that at least one layer of the single-layer or multilayer coat is a cobalt coat consisting of an anhydrous oxide film elementally containing cobalt is provided. This cobalt coat preferably contains a compound in composition expressed by at least one type of composition selected from a group consisting of CoO, Co.sub.2O.sub.3, Co.sub.3O.sub.4, nCoO.mAl.sub.2O.sub.3 and nCoO.mSiO.sub.2 (n, m: arbitrary positive real numbers).

The invention relates to a collection of composite plateletlike particles comprising a core and at least one coating layer consisting essentially of a compound having from 60 to 95% by weight of carbon and from 5 to 25% by weight of nitrogen, the balance to 100% being selected from elements of the group consisting of hydrogen, oxygen and sulfur. The invention also relates to processes for the manufacture thereof, to polymer compositions containing it, and to the use thereof as effect pigments. Preferably, the process for preparing the instant collection of particles comprises the steps of (a) suspending plateletlike particles in a liquid; (b) optionally adding a surface modifier, a polymerisation catalyst or both; (c) before or after step (b), adding one or more polymers containing nitrogen and carbon atoms, or one or more monomers which are capable to polymerize to said polymer; (d) effecting a polymeric coating layer to be formed on the surface of said plateletlike particles from the polymers or monomers added at step (c); (e) isolating said plateletlike particles having said polymeric coating layer from the suspension; and (f) heating said plateletlike particles having said polymeric coating layer to a temperature of from 100.degree. C. to 1000.degree. C. in a gaseous environment.

The invention concerns colored aluminum pigments comprising flake-form aluminum substrates which are coated with a metal oxide layer. The pigments are produced by a process which involves the steps of mixing a ground color pigment with a flake-form aluminum in the presence of a solvent. A metal acid ester is then added to the mixture and is then hydrolyzed to form a metal oxide layer on the aluminum substrate, followed by removal of the solvent and drying of the pigment. The pigments are useful as special-effect pigments in paints, lacquers, coatings, plastic materials, printing inks and cosmetic preparation.

Goniochromatic luster pigments based on multiply coated platelet-shaped metallic substrates comprising at least one layer packet of A) a layer consisting essentially of silicon oxide, silicon oxide hydrate, aluminum oxide and/or aluminum oxide hydrate, and B) a nonselectively absorbing, silicon-containing layer which is at least partially transparent to visible light, and also, if desired, additionally C) an outer layer which consists essentially of colorless or selectively absorbing metal oxide, are useful for coloring paints, inks, including printing inks, plastics, glasses, ceramic products and decorative cosmetic preparations.