Patent ID: 7964057

Claim:
A method for forming a cold seal on a polymer film; said method comprising: (a) applying to the polymer film a layer of a polymer latex comprising a polymer having a first phase and a second phase, where the first phase has a T g from −55° C. to −30° C., from 1% to 5% carboxylic acid monomer residues, and at least 65% of residues of C 4 -C 8 alkyl acrylates; and the second phase has a T g of at least 80° C., at least 90% of residues of styrene and at least 1% less carboxylic acid monomer residue than the first phase; wherein the first phase is from 80% to 95% of the polymer, and the polymer is substantially free of monomer residues having more than one carboxyl group; and (b) forming a seal by contacting two polymer film surfaces comprising a layer of polymer latex to form a seal without heating.