Patent ID: 7842757

Claim:
A solid pigment preparation in the form of granules, powder, pellets or tablets, the solid pigment preparation comprising pigment particles and a dispersant resin, wherein the preparation comprises at least 35% by weight of the pigment particles and at most 65% by weight of the dispersant resin, calculated on the combined weight of pigment particles and dispersant resin, wherein the dispersant resin comprises a polymer backbone produced by chain-reaction polymerization having pendent hydrophilic alkylene oxide side groups and wherein the pigment dispersant resin is prepared by the reaction of (i) a hydrophilic alkylene oxide monoamine monoalkylether of the formula wherein R is hydrogen, R 1 is selected from C 1 to C 4 alkyl groups, n is 0 to 25, m is 1 to 50, with the proviso that n+m≦50, and, (ii) a polymer backbone having cyclic carboxylic anhydride groups, wherein in a first reaction step the cyclic carboxylic anhydride is opened by the amine group of the hydrophilic alkylene oxide monoamine monoalkylether to form an amide group and a carboxylic acid group (amic acid group), and wherein at least part of the amic acid forms an imide in a second reaction step, wherein the pigment particles within the preparation have an average particle size in the range of 50 nm to 5,000 nm.