Patent ID: 8222362

Claim:
A polymer latex made by free-radical polymerization comprising polymer particles comprising: (a) structural units derived from: at least one conjugated diene monomer, and at least one aromatic vinyl monomer, and (b) at least one chain transfer agent having the general formula RSH, wherein R is a linear alkyl group having 3 to 20 carbon atoms, wherein: no vinyl pyridine is used in the polymerization, the polymer latex is polymerized in the presence of said at least one chain transfer agent, the polymer latex does not comprise structural units based on unsaturated carboxylic acids and/or does not comprise carboxylic groups, the polymer latex comprises a solids content of from 55% to 85%, and the dried latex polymer has a Mooney viscosity measured according to DIN 53 523 of 85 to 155.