Patent ID: 7687554

Claim:
A concentrated aqueous polymer dispersion of particles with an average particle size of less than 1000 nm said particles comprising a) a polymer carrier prepared by heterophase oil in water radical polymerization of at least one ethylenically unsaturated monomer selected from the group consisting of C 1 -C 18 acrylates, C 1 -C 18 methacrylates, acrylic acid, (meth)acrylic acid, styrene, vinyltoluene, hydroxy-functional acrylates, hydroxy-functional (meth)acrylates, acrylates derived from alkoxylated alcohols, (meth)acrylates derived from alkoxylated alcohols, multifunctional acrylates and multifunctional (meth)acrylates in the presence of b) a non-polar organic light stabilizer, 1 wherein the non-polar organic light stabilizer has a water solubility of less than 1% by weight at room temperature and atmospheric pressure, wherein the weight ratio of non-polar organic light stabilizer to polymer carrier is greater than 100 parts of light stabilizer per 100 parts of carrier and particle content of the aqueous polymer dispersion is more than 20% by weight based on the total weight of the aqueous polymer dispersion.