Herstellen von Polyurethanfaeden

摘要

1,051,024. Polyurethane filaments. ASAHI KASEI KOGYO KABUSHIKI KAISHA. July 4, 1963 [July 7, 1962], No. 26540/63. Heading B6B. [Also in Division C3] Polyurethane elastic yarn is produced by dissolving in dimethylformamide or dimethylacetamide a prepolymer produced by reacting a diol of M.W. 700-4,000 which is a hydroxy terminated polyether, polyester, polylactone or poly(oxyalkylene carboxyalkylene) with 150- 300 mole per cent of an organic diisocyanate based on the amount of diol polymer and 3 to 30 mole per cent of water based on the amount of diisocyanate, adding water to the resulting solution at room temperature to cause the solution to gel, heating the resulting gel to 120- 180‹C. to form a viscous solution, and subjecting the solution to wet or dry spinning. The solution may be subjected to spinning in air, water, aqueous ammonia, an aqueous solution of an inorganic salt, glycerine or an alcohol. The polyether may be polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polypentamethylene glycol, polyhexamethylene glycol, polyoctamethylene glycol or a copolymer of ethylene and propylene oxides. The poly- (oxyalkylene carboxyalkylene) may be poly(dimethyl-#-caprolactone, ethylene glycol), poly- (#-methyl-#-caprolactone, tetramethylene glycol), poly(#-caprolactone, ethylene glycol), poly- (#-caprolactone propylene glycol), poly(8-valerolactone ethylene glycol) and poly(#-valerolactone propylene glycol). The polylactone may be poly(#-valerolactone), poly(#-caprolactone), poly(α-methyl-caprolactone) and poly((#,γ,#-trimethyl-#-caprolactone). In a typical example (1) 1 mole of polytetramethylene glycol of M.W. 1200 was reacted with 2 moles of diphenylmethane 4,41-diisocyanate in the presence of 5 mole per cent of water based on one diisocyanate and triethylene diamine at 120‹ C. for 1 hour. Dimethylformamide was added to form a homogeneous solution at 20‹ C. and then water mixed with dimethylformamide was added. After foaming the gel was heated to yield a solution which was extruded from a spinneret.