| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject fibers with high hygroscopicity and biodegradability by reacting a liquid containing a mixture of a specific urethane prepolymer, a chain extender and a terminal blocking agent, and during or after the reaction, by adding a butyryl chitin solution to the reaction system followed by spinning and then alkali treatment of the fibers thus formed. SOLUTION: The modified polyurethane elastic fibers are obtained by the following process: a mixed dimethylacetamide solution of a urethane prepolymer, a chain extender having two active hydrogens reactive with isocyanate groups, and a terminal terminator having the above one active hydrogen, is subjected to reaction, and during or after the reaction, a butyryl chitin solution prepared by dissolving 5-40 wt.% of butyryl chitin in dimethylacetamide is added to the above reaction system to prepare a spinning dope, which, in turn, is put to dry spinning to form polyurethane elastic fibers containing 3-15 wt.% of butyryl chitin, and the polyurethane elastic fibers thus formed are treated with an alkali; wherein the urethane prepolymer is produced by reaction of a polydiol 1,000-2,500 in number-average molecular weight such as polyoxytetramethylene glycol with 110-210 mol% of an organic diisocyanate such as 4,4'- diphenylmethane diisocyanate. |
