Patent ID: 7939572

Claim:
An aqueous dispersion of polymeric particles, said particles comprising: from 5% to 80% by weight, based on the weight of said polymeric particles, of a first polymer comprising at least one copolymerized ethylenically unsaturated monomer and formed by polymerization at a temperature of 78° C. to 92° C.; and substantially encapsulating said first polymer, from 20% to 95% by weight, based on the weight of said polymeric particles, of a second polymer comprising at least one copolymerized ethylenically unsaturated monomer, said second polymer having Tg of from −40° C. to 30° C., wherein polymerization of the second polymer is begun at a temperature of from 5° C. to 40° C. and the temperature is allowed to rise during the reaction such that at least 90 weight % of said second polymer is formed by polymerization at a temperature of from 5° C. to 65° C.