Patent ID: 11440978

Abstract:
A multistage emulsion polymerization process comprises polymerizing a first monomer composition comprising from 50 to 95 weight percent of vinyl acetate, from 5 to 40 weight percent of at least one vinyl ester of a C5 to C18 unsaturated carboxylic acid, and optionally up to 40 weight percent of ethylene, all based on the total weight of monomers in the first monomer composition, to produce a first stage polymer. A second monomer composition comprising 40 to 89.95 weight percent of at least one ester of methacrylic acid or a vinyl aromatic monomer, 10 to 59.95 weight percent of at least one ester of acrylic acid, and from 0.05 to 10 weight percent of at least one comonomer with acid functionality, based on the total weight of monomers in the second monomer composition, is then polymerized in the presence of the first stage polymer to produce a second stage polymer.