Patent ID: 7683120

Claim:
A composition comprising (i) a particulate solid, wherein the particulate solid is a pigment, (ii) an organic medium, wherein the organic medium is an organic liquid or a plastics material; and (iii) a compound of Formula (1) and salts thereof: B—CO-Z-R Formula (1) wherein B comprises a hydrophobic alkyl chain, based on polyisobutylene with a number average molecular weight of 300-5000 which together with the —CO— group is the residue of a polyisobutylene succinic anhydride; Z is a divalent bridging group which is attached to the carbonyl group through an oxygen or nitrogen atom and represented by the formula: —N(T)-A- or —O-A-; wherein T is a hydrogen, or a C1-18 hydrocarbyl radical, or a group represented by A or the residue of the polyisobutylene succinic anhydride; A is an alkylene or hydroxyalkylene radical containing from 2-6 carbon atoms; R is a quaternary ammonium group represented by the formula: —N + (T 2 )(T 3 )(T 4 )W − wherein T 2 , T 3 and T 4 are each independently hydrogen, optionally substituted alkyl alkaryl or cycloalkyl groups, or R is a N-oxide functionalized quaternary ammonium group; and W − is a colourless or coloured anion.