Treatment of elastic artificial filaments

摘要

1,102,887. Treating elastic synthetic filaments. CELANESE CORPORATION OF AMERICA. 9 June, 1965 [22 June, 1964], No. 24357/65. Heading B5B. Filaments exhibiting elastic stretch and made from synthetic elastomeric polymers are treated to reduce their permanent set with a swelling agent and then dried or allowed to dry spontaneously, whereby substantially all the swelling agent is removed. The filaments can be stretched during the treatment, e.g. by 450 to 500% of their original length, but preferably by not more than 200% of their original length. Throughout the Specification, the stretch percentages are the increase in length of the filaments as a percentage of the original length. In some cases the filaments are treated while held taut without stretch or even while completely relaxed and thus free to shrink. The filaments may particularly be made from elastomeric segmented copolymers comprising segments derived from essentially amorphous low melting point soft polymers such as polyesters, polyethers or polyhydrocarbons alternating in the chemical chain with hard high melting point polymers such as polyureas, polyurethanes or polyamides. The filaments may advantageously be made from blends of segmented copolymers. The swelling agents used may be the lower mol. wt. monohydric alkyl alcohols, the lower mol. wt. halogenated aliphatic hydrocarbons, substituted aromatic hydrocarbons, the lower mol. wt. ketones, methanol-methylene chloride blends and mixtures of acetone and water. The filaments after treating with the swelling agent and drying are preferably subjected to a heat treatment, preferably at 100‹ to 150‹ C. The filament may be stretched by 200 to 500%, preferably 250 to 400% at room temperature and relaxed to a length less than the stretched length before being contacted with the swelling agent. The filaments used in the examples are made from polyester-urethane copolymers obtained by reacting hydroxyl poly-(tetramethylene adipate), butanediol-1,4, and diphenyl methane - p,p1 - di - isocyanate by dry-spinning a 30% solution in acetone of the copolymer or of a blend of two such copolymers.