Abstract: Carboxylic acid functional branched polyester having an acid number of at least 77 mg KOH/g, being the reaction product of a polybasic organic carboxylic acid and/or its anhydride and a branched hydroxyl functional polyester obtained from (i) 70 to 100 mole % of terephthalic acid and/or isophtalic acid and, optionally, from 0 to 30 mole % of another polycarboxylic acid, referring to the polyacid constituents, (ii) 10 to 50 mole % of ethylene glycol, 50 to 88.5 mole % of at least one other aliphatic or cycloaliphatic diol and 1.5 to 15 mole % of at least one polyol having at least 3 hydroxyl groups, referring to the polyol constituents.