| abstract |
An aqueous copolymer dispersion is formed by emulsion polymerization of a monomer mixture comprising (a) 20 to 80 wt.% of one or more (meth) acrylic acid esters A, whose homopolymer(s) have a Tg > 25°C and at least one has a biorenewable carbon content of at least 50 wt.% of the total carbon content of the ester; (b) 19 to 79 wt.% of one or more (meth)acrylic acid esters B whose homopolymer(s) have a Tg < 25°C; (c) 0.5 to 10 wt.% of at least one monomer selected from unsaturated sulfonic, phosphoric and phosphonic acids, and unsaturated carboxylic acids, anhydrides and amides thereof; (d) up to 10% by weight of one or more functional monomers selected from hydrolysable silane compounds, epoxy-containing compounds, ureido-containing compounds and carbonyl-containing compounds, and (e) less than 5 wt.% of one or more further monomers, wherein the total percentages of comonomers (a) to (e) equals 100%. |