Patent ID: 8048524
Filing Date: 2011-11-01
Classification: C08F,C08L,Y10T

Abstract:
1. A multilayer polymer latex comprising: a seed; a rubbery core surrounding the seed; and a shell surrounding the rubbery core, wherein the seed comprises a copolymer of a vinyl monomer and a hydrophilic monomer, the copolymer containing: i) 65-99.0 parts by weight of a vinyl unit, ii) 0.5-30 parts by weight of a hydrophilic unit, and iii) 0.5-5 parts by weight of a crosslinker unit, the parts by weight being based on the sum of the seed units taken as 100 parts by weight, wherein the rubbery core surrounding the seed comprises: i) 97.0-99.9 parts by weight of alkyl acrylate where the alkyl group contains 1 to 8 carbon atoms, and ii) 0.1-3.0 parts by weight of a crosslinker unit, the parts by weight being based on the sum of the core units taken as 100 parts by weight, wherein the shell surrounding the rubbery core comprises at least one unit selected from an alkyl methacrylate unit where the alkyl group contains 1 to 4 carbon atoms, and an aromatic vinyl unit, and wherein the seed is present at an amount of 0.3-10 parts by weight, the rubbery core at 89.7-94.7 parts by weight, and the shell at 0.3-10 parts by weight, the parts by weight being based on the sum of the polymer latex units taken as 100 parts by weight.