Patent ID: 8013085

Claim:
A process for preparing an aqueous polymer dispersion, the process comprising: either (1) preparing polymer particles A having a weight average particle diameter of ≧1 nm from at least one ethylenically unsaturated monomer A by a polymerization initiated by at least one free-radical initiator and then polymerizing at least one ethylenically unsaturated monomer B in an aqueous medium in the presence of said polymer particles A and at least one dispersant, and initiated by at least one hydrolysis-stable transition metal complex, or (2) preparing polymer particles A having a weight average particle diameter of ≧1 nm from at least one ethylenically unsaturated monomer A by a polymerization initiated by at least one hydrolysis-stable transition metal complex and then polymerizing at least one ethylenically unsaturated monomer B in an aqueous medium in the presence of said polymer particles A and at least one dispersant, and initiated by at least one free-radical initiator.