Abstract: The present invention is directed to a process for the preparation of modified copolymers as a pigment dispersant for coating compositions comprising the steps ofa) polymerizingi) an ethylenically unsaturated monomer containing an isocyanate group withii) ethylenically unsaturated monomer having no functional group capable of undergoing a reaction with said isocyanate group to form a copolymer with isocyanate andb) reating stepwise or simultaneously said isocyanate groups withiii) a polyalkylenglycol monoalkyl ether or amine andiv) optionally, a compound having one primary or one secondary amino group or another alcohol.