Patent ID: 8754163

Claim:
Process for preparing a cross-linkable aqueous copolymer dispersion of a water-dilutable copolymer A, comprising the steps: 1. polymerizing by radical copolymerization a. 5 to 64% by weight of a reaction product of at least one fatty acid having at least one ethylenic double bond and one hydroxyl group in the molecule with a polyalcohol having a hydroxyl functionality of 2 to 8 and b. 36 to 95% by weight of at least one additional unsaturated monomer b), wherein the at least one additional unsaturated monomer b) contains hydrophilic ionic groups and wherein the % by weight of monomers a) and b) are adding up to 100%, 2. neutralizing the hydrophilic ionic groups of the copolymer A before and/or during dispersing or dissolving the copolymer A in an aqueous carrier, 3. dispersing or dissolving the neutralized copolymer A in an aqueous carrier, wherein the at least one additional unsaturated monomer b) is polymerized in presence of at least 20% by weight of the total amount of the reaction product a), thereby forming a copolymer A) having an acid number of at least 10 mg KOH/g solids.