Standard Brands Incorporated

Edwin L Speakman

Adrian P Kightlinger

Grant T Van Duzee

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.

Stable liquid, amylopectin starch graft copolymer compositions

This invention discloses stable, aqueous polymeric dispersions comprised of at least 25% solids, dry basis, of a starch graft copolymer of a thinned and derivatized starch and at least one vinyl monomer. The starch has a degree of substitution of at least about 0.05 and an intrinsic viscosity of not less than about 0.12 deciliters per gram. The starch graft copolymers have a starch/monomer ratio of less than about 100/25. The dispersions are stable over extended periods of time at normal storage temperatures. Processes for the production of the dispersions are also disclosed.

Stable, liquid starch graft copolymer composition

This invention relates to removal of cerium, used as a free-radical initiator, from aqueous polymeric dispersions, particularly starch graft copolymer dispersions, by adsorbing cerium (III) onto a strong cation exchange resin, to separation of the adsorbed cerium (III) from the resin using a solution such as sodium sulfate or sodium oxalate to form a cerium (III) precipitate, and to oxidation of the separated cerium (III) to cerium (IV).

Recovery of cerium from polymer dispersions

Acid modified oxidized hydroxyalkyl starch is prepared by the sequential steps of:

Method for preparing an acid modified oxidized hydroxyalkyl starch

Granular starch is partially depolymerized by reaction with hydrogen peroxide in the presence of a salt selected from the group consisting of alkali metal chlorides, ammonium chlorides and mixtures thereof, and cupric ions while maintaining the pH of the reaction mixture in the range of from about 5.5 to about 7 by the addition of alkali thereto.

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Clinton, IA, United States of America

Edwin L Speakman