Patent ID: 8163207

Claim:
Isolated microcapsules comprising a capsule core, a polymeric capsule wall and, disposed on the outer surface of the polymeric capsule wall, a polyelectrolyte having an average molecular weight in the range from 500 g/mol to 10 million g/mol, wherein (1) the polymeric capsule wall contains units obtained by the polymerization of the following monomers: 10% to 100% by weight of at least one C 1 -C 24 -alkyl ester of acrylic and/or methacrylic acid, 0% to 80% by weight of a water-insoluble or sparingly water-soluble bi- or polyfunctional monomer, and 0% to 90% by weight of other monomers, all based on the total weight of the monomers, (2) the microcapsules contain from 0.1% to 10% by weight of the polyelectrolyte based on the total weight of the microcapsules, (3) the microcapsules have an average particle size of 1.5-2.5 μm, and (4) 90% of the microcapsules have a particle size ≦4μm.