Patent ID: 8236905

Claim:
A hyperbranched polyester comprising ethylenically unsaturated groups, obtained by a method, comprising: (c) reacting at least one compound having at least one ethylenic double bond with at least one hyperbranched polyester to obtain the hyperbranched polyester comprising ethylenically unsaturated groups, wherein the at least one compound having at least one ethylenic double bond is bonded to the hyperbranched polyester, and the hyperbranched polyester is obtained by condensing; (a) at least one dicarboxylic acid or derivative thereof with at least one at least trifunctional alcohol; or (b) at least one tricarboxylic or higher polycarboxylic acid or derivative thereof with at least one diol, wherein a molar ratio of hydroxyl groups of the at least one at least trifunctional alcohol or at least one diol to carboxyl groups of the at least one dicarboxylic acid or at least one tricarboxylic or higher polycarboxylic acid, respectively, is from 1.5/1 to 1/1.5.