National Starch and Chemical Corporation

National Starch and Chemical Investment Holding Corporation

Teresa A Dirscherl

Martin M Tessler

Otto B Wurzburg

Daniel B Solarek

Wadym Jarowenko

Henry R Hernandez

Peter T Trzasko

Improved non-crosslinked and non-degraded amphoteric starch derivatives containing tertiary amino or quaternary ammonium groups and anionic phosphate groups are disclosed. The derivatives which are defined by a minimum bound phosphorus content, a minimum viscosity and other criteria have use as wet-end additives and provide improved drainage properties in the manufacture of paper.

Amphoteric starches and process for their preparation

Improved amphoteric starch derivatives containing tertiary amino or quaternary ammonium groups and anionic phosphate groups are disclosed. The derivatives which are defined by a minimum bound phosphorus content, a minimum viscosity and other criteria have use as wet-end additives and provide improved drainage properties in the manufacture of paper.

Starch derivatives capable of forming reversible gels are provided. Aqueous dispersions or solutions of the derivatives form thermally reversible hot gels at temperatures above 70.degree. C. and a pH of 3-8, in addition to exhibiting substantial increases in viscosity upon cooling from 95.degree. to 70.degree. C. The starch derivative may be alkali gelatinized at a pH 13 or above and the gel formed at a pH of from 1-10. The gelling agents are starch ethers or starch esters having an amylose content of at least 17% by weight with the ether or ester substituent comprising a linear saturated or unsaturated hydrocarbon chain of at least 12 carbon atoms.

Starch derivatives forming reversible gels

Sulfosuccinate polygalactomannan half-esters, as well as the alkyl- and alkenyl-sulfosuccinates thereof, are prepared by reacting the gum with sulfosuccinic anhydride or a C.sub.1 -C.sub.22 -alkyl- or C.sub.3 -C.sub.22 -alkenyl sulfosuccinic anhydride. The reactions are carried out at about pH 7.5 in a two-phase system of solid gum slurried in an aqueous medium containing a water-miscible solvent. Sulfomaleate half-esters are prepared in a similar manner using sulfomaleic anhydride. Disulfosuccinate half-esters are prepared by reacting the sulfomaleate gum half-ester with sulfurous acid or a bisulfite salt such as sodium bisulfite.

Sulfosuccinate, alkyl- and alkenyl sulfosuccinate, sulfomaleate, and

Novel C.sub.1 -C.sub.22 alkyl- and C.sub.3 -C.sub.22 alkenyl-sulfosuccinate starch half-esters are prepared by reacting a starch base or a modified starch base containing anionic, cationic, and/or nonionic substituent groups with about 0.1 to 100% by weight of the corresponding alkyl- or alkenyl-sulfosuccinic anhydride. The reaction is carried out at pH 5-9 and at 5.degree.-90.degree. C. for 0.5-20 hours or at pH 9-11 at 5.degree.-30.degree. C. for about 0.5-3 hours. This one-step method may also be used to prepare sulfosuccinate half-esters. The long chain derivatives (e.g. octyl-, octadecyl-, octenyl-, and dodecenyl-sulfosuccinate half-esters) are hydrophobic.

Alkyl- and alkenyl-sulfosuccinate starchhalf-esters, a method for the

Novel starch sulfomaleate half-esters are prepared by reacting a starch base or a modified starch containing anionic, cationic, and/or nonionic substituent groups with about 0.1 to 100% by weight of sulfomaleic anhydride or its salts. The reaction is carried out at pH 5-9 and at 5.degree.-90.degree. C. for 0.5-20 hours or at pH 9-11 and at 5.degree.-30.degree. C. for about 0.5-3 hours. The starch sulfomaleates may be reacted with sulfurous acid or its acid salts (e.g. sodium bisulfite) to form the novel starch disulfosuccinate.

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Netcong, NJ, United States of America

Teresa A Dirscherl