Patent ID: 6896726

Claim:
A surface-treated pigment of formula wherein Ar 1 and Ar 2 are each independently of the other a phenyl or naphthalene group. n is an integer 1 or 2, n1 and n2 denote a value from 0 to 0.15, the sum of n1 and n2 being a value from 0.01 to 0.15, X 1 is a branched or unbranched alkyl radical or alkenyl radical having from 1 to 25 carbon atoms, the said alkyl radical is interrupted by one or more S or O atoms, or is a group —Y—(CH 2 ) m —R 1 , wherein Y is a group —CH 2 —, —O—, —S—, —C(O)O—, —C(O)—, —C(O)—NH—, —SO 2 NH— or —SO 2 — and R 1 is a hydrogen atom or a group —NR 2 R 3 , wherein R 2 and R 3 are each independently of the other a hydrogen atom or a C 1-6 alkyl radical, and m is an integer from 1 to 24, X 2 is a group —COOH, —SO 3 H or —P(O)OX 3 OX 4 , wherein X 3 and X 4 are each independently of the other a hydrogen atom or a C 1-6 alkyl radical, and pigment denotes an organic pigment, a mixture of organic pigments, a solid solution of organic pigments or a crystalline solid solution of organic pigments.