Process for improving the behavior in the filament stretching a polymer conjugates and a polyurethane hard elastomerica

摘要

1427889 Polyurethane conjugate filaments MONSANTO CO 19 April 1974 [20 April 1973] 17226/74 Heading B5B Conjugate filaments of a hard polymer (e.g. nylon, polyesters or polyolefins) and an elastomeric polyurethane comprise a polyurethane which is the reaction product of (i) a diol of mol. wt. between 800-3000, (ii) a polyol composed primarily of a diol of mol. wt. below 500 and (iii) a diisocyanate, in which the content of unreacted isocyanate groups prior to spinning is 1-45 microequivalents per gm. of polymer. Preferably the concentration is 10 to 120 microequivalents/gm. after 4À8 hours and the polymer is stored until the concentration is reduced to 1-45. The polyol may additionally comprise a multifunctional compound containing three or more hydroxyl groups per mol., in small amounts. The time T, in hours, at which the polymer is spinnable can be calculated using the following formula in which NCO m is the isocyanate concentration in microequivalents/gm. after reaction for T m hours, and X is the final desired isocyanate concentration, i.e. X may be 1-45:-