Patent ID: 8530591

Claim:
A latex composition comprising sequentially polymerized polymer particles formed in at least two polymerization stages so as to form a first phase polymer, which results from a first polymerization stage, and a second phase polymer, which results from a second polymerization stage, wherein: the first phase polymer is made from a first set of constituent monomers, has a number average molecular weight greater than about 100,000 Daltons, has a glass transition temperature from 10° C. to 16° C. and at least 10° C. higher than the glass transition temperature of the second phase polymer, and optionally comprises a first crosslinkable monomer; the second phase polymer is made from a second set of constituent monomers, has a number average molecular weight between about 7,000 to 80,000 Daltons, has a glass transition temperature below about 5° C., and comprises a second crosslinkable monomer; and wherein the second phase polymer comprises between about 30% to about 50% of the total weight of the polymer, and wherein the glass transition temperature is calculated using Fox's law.