Method of improving storage stability of pigments
AssigneeCiba-Geigy Corporation
InventorsPhilippe Bugnon, Abul Iqbal, Alison MacLennan, Iain F. Fraser
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Abstract
A method of improving the storage stability of a coloured organic pigment in powder form which comprises coating pigment particles with a solid polymer which is a polar group-containing vinyl polymer, said polar group being a hydroxy, carboxyl, carboxylic ester, anhydride or carboxamide group, or a cellulosic polymer, thereby inhibiting reduction of tinting strength of the pigment on storage.
Claims20
A method of improving the storage stability of a colored organic pigment in powder form which comprises coating pigment particles with a solid polymer which is a polar group-containing vinyl polymer, said polar group being a hydroxy, carboxyl, carboxylic ester, anhydride or carboxamide group, and crosslinking the polymer coating on the pigment by treating the polymer with a crosslinking agent therefor, thereby inhibiting reduction of tinting strength of the pigment on storage.
A particulate pigment composition comprising particles of a colored organic pigment coated with a crosslinked solid polar group-containing vinyl polymer.
Dependencies are inferred from the claim text.