Patent ID: 6375732
Filing Date: 2002-04-23
Classification: C09B

Abstract:
A process for the preparation of coprecipitated hybrid pigments consisting ofa) diketopyrrolo[3,4-c]pyrrole pigments according to the formula (I) â€ƒwhere A and B are each, independently of the other, a radical of the formula (II) â€ƒin which R1 and R2 are each, independently of the other, hydrogen, halogen, C1-C5alkyl, nitrile or phenyl; and b) of pigments bearing â€”NH, â€”OH or â€”CONHâ€” groups, comprising mixing a diketopyrrolo[3,4-c]pyrrole alkali salt suspension with a crude pigment bearing â€”NH, â€”OH or â€”CONHâ€” groups in the presence of an excess of base and precipitating the formed mixture of metal salts together.