Graft copolymer with a urethane/urea group as a pigment dispersant

A composition suitable for use as a pigment dispersant, comprising a graft copolymer, wherein the graft copolymer has a weight average molecular weight of about 3,000-150,000 and comprises about 10-90% by weight of a polymeric backbone and correspondingly about 90-10% by weight of macromonomer side chains attached to the backbone wherein

• (1) the polymeric backbone is formed from polymerized ethylenically unsaturated monomers and
• (2) the side chains are macromonomers are attached to the backbone at a single terminal point and are formed from polymerized ethylenically unsaturated monomers and have a weight average molecular weight of about 1,000-30,000;
• wherein the graft copolymer contains about 2 to 70% by weight, based on the total weight of the graft copolymer, of polymerized ethylenically unsaturated monomers containing functional hydroxyl groups that are polymerized into the backbone, the side chains or both, wherein the hydroxyl groups of the copolymer are reacted with a compound bearing at least two isocyanate groups and the isocyanate compound is further reacted with ammonia or a compound bearing a primary or secondary amine to form at least one urea group on the graft copolymer attached through a urethane linkage.