abstract |
Aqueous vinyl ester/acrylate copolymer emulsions possessing enhanced wet pick strength in paper coating compositions comprise a vinyl ester/acrylate copolymer colloidally dispersed in an aqueous medium, the copolymer consisting essentially of (a) a vinyl ester of a C1-C12 alkanoic acid, (b) 2 to 50 wt % of an alkyl acrylate, and (c) 0.1 to 10 wt % of an ethylenically unsaturated mono- or dicarboxylic acid or half ester thereof. The copolymer is prepared by an aqueous emulsion polymerization process comprising the use of a stabilizer system consisting essentially of an alkylphenoxy polyethoxy ethanol and an anionic surfactant and, in the preferred embodiment, the use of a seeding procedure. |