| 摘要 |
1,168,574. Producing elastic woven and knitted fabric. KURASHIKI RAYON K.K. 16 Feb., 1968 [16 Feb., 1967], No. 7808/68. Heading DIP. Elastic woven or knitted fabrics are produced by applying to the surface of polyurethane continuous elastic filaments an aqueous solution of polyvinyl alcohol having a degree of saponification of 50-100%, heating and drying them while stretched to at least 150% of their original length to produce polyurethane filaments whose elongation is not greater than 100% and whose Young's modulus, expressed in terms of tenacity at 50% elongation, is at least 0.4 gram per denier, making woven or knitted fabric from these filaments with a non-elastic yarn and treating the resulting fabric with water at 60‹-100‹C to remove the polyvinyl alcohol and cause shrinkage of the fabric. The polyvinyl alcohol which may have a degree of polymerization of 300-4,000 may be applied to the filaments as a 1-30% by weight aqueous solution by dipping, spraying or by means of rollers, 5-200% by weight of the polyvinyl alcohol preferably being applied to the filaments. Stretching may be effected prior to, during or after application of the polyvinyl alcohol to the filaments, the filaments being maintained in the stretched condition during drying, e.g. at between room temperature and 100‹C. The filaments are preferably given a heat treatment at a temperature of from 60‹C to a temperature just below the decomposition temperature of the filaments during at least a certain period before the completion of the' step of drying in a stretched state. As a result of the treatment with hot water the woven or knitted fabric may shrink by 20-80%. The polyurethane continuous elastic filaments may be produced by dry-spinning, melt-spinning or wetspinning a polyurethane polymer obtained by the reaction of a polymer glycol having a melting point of not more than 80‹C, e.g. a polyether glycol, polyester glycol or polyether ester glycol, with an organic disocyanate, e.g. ethylene or hexamethylene diisocyanate, cyclohexane 1, 4-diisocyanate, tolylene diisocyanate, biphenylene 4, 4'-diisocyanate, diphenyl methane 4, 4'-diisocyanate and 1, 5-naphthylene diisocyanate, and a chain extender, e.g. hydrazine, ethylene diamine, tetramethylene diamine, hexamethylene diamine, 1, 5-naphthylene diamine, p-phenylene diamine, ethanol, aminoethylethanolamine, ethylene glycol, propylene glycol, 1, 4-butanediol, 1, 5-pentanediol and water. Suitable non-elastic fibres yarns which may have been subjected to a bulking treatment are polyester, polyamide, polyacrylonitrile, polyethylene, viscose rayon, and cotton fibre yarns. The polyurethane filaments and non-elastic fibre yarns may be in the form of blended yarns, core yarns or plied yarns when made up into woven knitted fabrics. |
