| abstract |
This invention relates to stable, aqueous polymeric dispersions comprised of graft copolymers of at least one vinyl monomer and a derivatized and thinned amylopectin starch, that is, a starch wherein the starch is made up entirely or almost entirely of amylopectin units such as waxy maize starch. The amylopectin starch is derivatized to a degree of substitution of at least about 0.01 and thinned to an intrinsic viscosity of not less than about 0.12 deciliters per gram. The graft copolymers have a starch/monomer ratio of less than about 100/25 by weight. The dispersions have high solids contents (25% by weight or greater) and are stable (show no excessive increase in viscosity and remain homogeneous) over extended periods of time. This invention also relates to processes for the production of the dispersions. |