Vinyl ester copolymer dispersions, method for their manufacture and use

摘要

Aqueous vinyl ester copolymer dispersion (A), stabilized with at least a protective colloid comprises at least an emulsifying agent and a polymer with a glass transition temperature of -30[deg] C to 15[deg] C, where the emulsifying agent exhibits: a viscosity of less than 8000 mPas, a weight average particle size of 0.5-10 mu m and a ratio of weight average particle size to number average particle size of at least 2.5. An independent claim is included for the preparation of (A) by the emulsion polymerization of at least a vinyl ester of an aliphatic carboxylic acid comprising providing 2-10 wt.% of at least a polyvinyl alcohol with a viscosity of at least 18 mPas, measured according to Hoppler with a 4% aqueous solution at 20[deg] C and/or at least another protective colloid that is not a polyvinyl alcohol and has a viscosity of 1000 mPas measured according to Hoppler with a 2% aqueous solution at 20[deg] C, 0.05-5 wt.% of at least a non-ionic and/or ionic emulsifier and 0-60 wt.% of the monomer(s) to obtain vinyl ester copolymer dispersion, and adding at least a vinyl ester of a carboxylic acid and at least an initiator of the radical emulsion polymerization to the mixture, where the nature and quantity of the monomers are selected in such a manner that a vinyl ester copolymer dispersion with a glass transition temperature between -30[deg] C to +15[deg] C is formed.