Process for the production of water-insoluble fibers of cellulose monoesters of maleic acid, succinic acid and phthalic acid, having an extremely high absorbability for water and physiological liquids
First Claim
1. Process for the production of water-insoluble fibers of cellulose monoesters of maleic acid, succinic acid or phthalic acid having an extremely high absorption ability of water and physiological liquids, comprising, in order:
- (a) preparing a solution of activated cellulose in dimethylacetamide or 1-methyl-3-pyrrolidon,(b) reacting the so-dissolved cellulose while extensively maintaining average degree of polymerization of 300-800, with a dicarboxylic acid anhydride in a mol ratio from 1 ;
0.20 up to 1 ;
4 at 20°
to 120°
C. and in the presence of a known esterification catalyst, over a period from 5 minutes to 20 hours to obtain a degree of esterification,(c) spinning the obtained cellulose monoester solution by means of wet spinning into a coagulation agent to form water-insoluble fibers of cellulose monoesters of maleic acid, succinic acid, or phthalic acid, and converting said fibers partially or completely into corresponding fiber-shaped salts of the cellulose monoesters of phthalic acid, maleic acid, or succinic acid in a substantially organic solvent by reaction with alkali metal hydroxide and/or alkali metal alcoholate or ammonia or primary or secondary amine.
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Abstract
Water-insoluble fibers of cellulose monoester of maleic acid, succinic acid, or phthalic acid having an extremely high absorption ability for water and physiological liquids are produced by (a) preparing at 20° to 80° C. a solution of activated cellulose in dimethylacetamide or 1-methyl-2-pyrrolidon containing 5 to 30% by weight activated cellulose of an average degree of polymerization from 300 to 800 and 3 to 20% by weight LiCl, (b) reacting the solution with a corresponding carboxylic acid anhydride in a mol ratio from 1:0.20 to 1:4 at 20° to 120° C. in the presence of known esterification catalyst until a degree of esterification from 0.1 to 1.7, (c) wet-spinning the cellulose monoester solution into a coagulation agent, with or without (d) converting the fibers of cellulose monoester of phthalic acid and, if necessary, the of cellulose monoester of maleic acid or succinic acid, in a substantially organic solvent by means of reaction with alkali metal hydroxide, alkali metal alcoholate, ammonia, primary or secondary amines, partially or completely into fiber-shaped salts.
18 Citations
11 Claims
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1. Process for the production of water-insoluble fibers of cellulose monoesters of maleic acid, succinic acid or phthalic acid having an extremely high absorption ability of water and physiological liquids, comprising, in order:
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(a) preparing a solution of activated cellulose in dimethylacetamide or 1-methyl-3-pyrrolidon, (b) reacting the so-dissolved cellulose while extensively maintaining average degree of polymerization of 300-800, with a dicarboxylic acid anhydride in a mol ratio from 1 ;
0.20 up to 1 ;
4 at 20°
to 120°
C. and in the presence of a known esterification catalyst, over a period from 5 minutes to 20 hours to obtain a degree of esterification,(c) spinning the obtained cellulose monoester solution by means of wet spinning into a coagulation agent to form water-insoluble fibers of cellulose monoesters of maleic acid, succinic acid, or phthalic acid, and converting said fibers partially or completely into corresponding fiber-shaped salts of the cellulose monoesters of phthalic acid, maleic acid, or succinic acid in a substantially organic solvent by reaction with alkali metal hydroxide and/or alkali metal alcoholate or ammonia or primary or secondary amine. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. Process for the production of water-insoluble fibers of cellulose monoesters of maleic acid or succinic acid having an extremely high absorption ability for water and physiological liquids, comprising, in order:
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(a) preparing a solution of activated cellulose in dimethylacetamide or 1-methyl-3-pyrrolidon, (b) reacting the so-dissolved cellulose while extensively maintaining average degree of polymerization of 300-800, with a dicarboxylic acid anhydride in a mol ratio from 1 ;
0.20 up to 1;
4 at 20°
to 120°
C. and in the presence of a known esterification catalyst, over a period from 5 minutes to 20 hours to obtain a degree of esterification of from 0.4 to 1.3 for a monoester solution of maleic acid, or a degree of esterification of from 0.3 to b 1. 7 for a monoester solution of succinic acid,(c) spinning the obtained cellulose monoester solution by means of wet spinning into a coagulation agent to form water-insoluble fibers of cellulose monoesters of maleic acid or succinic acid, without any subsequent neutralization of the obtained fibers.
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Specification