Patent ID: 6361595
Filing Date: 2002-03-26
Classification: C09B,C09D

Abstract:
A process for the preparation of stabilised pigment compositions, which comprises mixing a water-miscible quaternary ammonium compound of formula III whereinR1, R2, R3 and R4 independently of each other stand for C1-C22alkyl, C2-C22alkenyl, benzyl, pyridyl, quinolyl, isoquinolyl or polyoxyalkylenyl, Xnâˆ’ is an anion, and n is 1, if the anion is monovalent, 2, if the anion is di-, or 3, if the anion is trivalent, and a water-immiscible organic solvent and a pigment, wherein the ratio by weight of pigment to water-miscible quaternary ammonium compound is from 50:50 to 99.5:0.5, and wherein the ratio by weight of pigment to water-immiscible organic solvent is from 90:10 to 99.5:0.5.