Patent ID: 7528194

Claim:
A method for the preparation of a comb copolymer comprising the steps a) polymerizing an ethylenically unsaturated monomer to an oligomer, cooligomer, polymer or copolymer in the presence of an initiator/regulator of formula (I) wherein L is a linking group selected from the group consisting of C 1 -C 18 alkylene, phenylene, C 1 -C 18 alkylene-oxy substituted with a phenyl group, phenylene-C 1 -C 18 alkylene, C 1 -C 18 alkylene-phenylene, C 1 -C 18 alkylene-phenylene-oxy and C 5 -C 12 cycloalkylene; R p and R q are independently tertiary bound C 4 -C 28 alkyl groups or C 3 -C 17 secondary bound alkyl groups which are unsubstituted or substitituted by one or more electron withdrawing groups or by phenyl; or R p and R q together form a 5, 6 or 7 membered heterocyclic ring which is substituted at least by 4 C 1 -C 4 alkyl groups and which may be interrupted by a further nitrogen or oxygen atom; and in a second step b) reacting the oligomer, cooligomer, polymer or copolymer prepared under a) together with a grafted copolymer, which grafted copolymer functional groups X in the graft structure, where X is selected from the group consisting of —COOH, —NH 2 , —NHR′, —C(O)—NHR′, and where R′ is C 1 -C 18 alkyl, in the melt in an apparatus suitable for mixing a polymer melt.