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US 5,441,689 AGranted
Process of making regenerated cellulose articles
AssigneeCourtaulds Limited
InventorPeter R. Laity
Life of this patent
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Abstract
Aqueous solutions of an amine N-oxide such as N-methyl morpholine N-oxide used in the manufacture of regenerated cellulose can be purified by passage through a strongly basic anion-exchange resin. The resin is regenerated by treatment with (1) an aqueous solution of a strong inorganic acid such as hydrochloric or sulphuric acid and (2) an aqueous solution of sodium hydroxide.
Claims18
A process for the manufacture of a regenerated cellulose article comprising the steps of:
- (a) dissolving cellulose in a tertiary amine N-oxide to form a solution;
- (b) contacting the solution with an aqueous bath to precipitate said regenerated cellulose article and to form spent bath;
- (c) purifying the spent bath by treatment with a strongly basic anion-exchange resin in hydroxide form,
- in which process the resin is regenerated by successive treatment with:
- (1) an aqueous solution of a strong inorganic acid;
- and
- (2) an aqueous solution of sodium hydroxide.
4 more elements
Dependencies are inferred from the claim text.