Method for manufacturing high-cationic starch solutions
AssigneeCiba Specialty Chemicals Corporation
InventorsAntti Likitalo, Jouko Käki
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Abstract
The invention relates to a method for producing starch solutions of high cation equivalent value (with a DS of 0.1-1.0). The starch to be cationized, advantageously an oxidized starch, is slurried to form a suspension of about 10-80% solids content in an aqueous mixture of a cationizing agent. In the cationization 2,3-epoxypropyltrimethylammonium chloride or an equivalent chlorohydrin-functional cationizing agent is used by about 90-1100 g per kg starch solids, and a catalyst is added to the slurry. The reaction is carried out at a high solids content of 40-80%, preferably 50-60%, in at least two successive steps, in the first of which a temperature of about 5-40° C. is maintained, and in the second step a temperature of about 70-180° C.
Claims12
A method for preparing highly cationized starch solutions having a degree of substitution (DS) of from 0.1 to 1.0, the method comprising:
- providing an aqueous mixture with a solids content of 40 to 80%, said mixture comprising starch, a cationizing agent in an amount of 90 to 1100 g per kg starch solids, a catalyst and water;
- and
- reacting said mixture in at least two successive steps, whereby —during the first step temperature is maintained in a range of 5 to 40° C., and —during the second step temperature of the reaction mixture is rapidly elevated to a temperature of 70 to 180° C. which increases the yield of the reaction and brings the reaction mixture into a solution form.
Dependencies are inferred from the claim text.