IMPROVEMENTS IN LUBRICATING SPANDEX YARNS

摘要

1,224,501. Wet-spinning spandex yarn. UNION CARBIDE CORP. 12 Feb., 1968 [23 Feb., 1967], No. 6755/68. Heading B5B. In a process for wet-spinning spandex yarn wherein the newly formed filaments are passed through an aqueous bath to extract excess solvent the improvement comprises employing in the aqueous bath at least 0À01% by weight of the bath of a water-soluble, non-hydrolysable siloxane-oxyalkylene block copolymer comprising (a) at least one siloxane block containing at least two siloxane units represented by the formula wherein each R group is a monovalent hydrocarbon group, a halogen-substituted monovalent group or a divalent hydrocarbon group and b is 1, 2 or 3, said siloxane block containing at least one of said siloxane units wherein at least one R group is a divalent hydrocarbon group, and (b) at least one oxyalkylene block containing at least one oxyalkylene group represented by the formula -R1O-, wherein R1 is an alkylene group containing from 2 to 10 carbon atoms, said siloxane and oxyalkylene blocks being interconnected by said divalent hydrocarbon group. Among the siloxane-oxyalkylene block copolymers those of the following formula are especially suited wherein Me is a methyl group, m is 0 to 72, n is 1 to 10, x is 3 to 25, y is 0 to 29, z is 2 to 3 inclusive and R11 is an alkyl group containing from 1 to 4 carbon atoms inclusive. In the examples spandex yarn of 140 denier was spun from a DMF solution containing 20% by weight of a polyester-based polyurethaneurea spandex polymer, pigmented with TiO 2 . The spandex polymer was made from polycaprolactone diol, p,p1-methylene diphenyl diisocyanate and ethylenediamine. The yarn was spun into a coagulation bath of water and DMF and then passed into a hot aqueous wash bath containing 0À1 wt. per cent of the said siloxaneoxyalkylene block copolymer. The yarn was then dried over a heated roll and then lubricated with a kiss roll with a finish of 3À6% wt. consisting of 84 wt. per cent of a commercial mineral oil and 16% isopropanolamine oleate prior to final winding on to a take-up package.