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Abstract

The invention relates to starch phosphates exhibiting improved properties with regard to application techniques, to a method for the production thereof, and to their use. Based on the disadvantages of the known prior art, the aim of the invention is to produce starch phosphates which have a high degree of substitution, which are resistant to hydrolysis, and which can be produced using phosphorylating agents comprising only a low level of toxicity. To this end, starch phosphates are provided in which the anhydroglucose units are substituted by phosphate ester groups and carbamide groups, and the average degree of substitution DS of the carbamide groups and of the phosphate ester groups is in a range, each time, that is greater than 0.01. The starting materials are used in a mol ratio of anhydroglucose units of the starch:phosphorus of the phosphorylating agent:urea of 1:0.1 to 1.5:0.3 to 4, and the reaction is carried out in a vacuum under a pressure of.ltoreq.100 torr and at reaction temperatures ranging from 90.degree. C. to 140.degree. C. Starch phosphates exhibiting different properties are obtained by reacting at different reaction temperatures, are distinguished by a good biodegradability, and are resistant to hydrolysis under normal conditions.

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First Claim