Verfahren zur Herstellung von zusammengesetzten Acrylfasern

申请公布号：: DE1660411(A1)
申请号：: DE19671660411
申请日期：: 1967.10.17
申请公布日期：: 1971.08.12
申请人：: JAPAN EXLAN CO.,LTD.
发明人：: SEKIGUCHI,HIDETO;TSUTSUI,NOBUHIRO;SUMI,TAKEHIKO
分类号：: D01F8/08
主分类号：: D01F8/08
摘要：: 1,207,990. Acrylic composite fibres. JAPAN EXLAN CO. Ltd. 17 Oct., 1967 [17 Oct., 1966 (3)], No. 47374/67. Heading B5B. A spirally crimped composite acrylic filament consisting of two acrylonitrile polymers or copolymers in lamellar longitudinal arrangement is produced by wet spinning two different acrylonitrile polymer or copolymer spinning solutions to form a composite filament which is washed and stretched to produce a swollen gel filament having a moisture content of at least 40%, and, without intermediate drying, relaxing the swollen gel filament in hot water or steam at 60‹ to 130‹ C. whilst free from tension and then drying the filament to fully develop its latent spiral crimp, the composition of the spinning solutions being chosen so that the polymer forming the inner element of the crimp is the higher shrinking component and has a degree of irreversible swelling of from 0À05 to 3 greater than that of the lower shrinking component. The acrylonitrile content of the more shrinkable polymer may be up to 10% by weight greater than that of the less shrinkable polymer. In particular the outer less shrinkable polymer may contain at least 88% of acrylonitrile, this content being at least 2% lower than that of the inner polymer. However the two acrylonitrile polymers may differ in acrylonitrile content by not more than 0À5% providing there is a concentration of strongly acidic groups in the inner more shrinkable polymer greater than that in the less shrinkable polymer by 10 to 30 milliequivalents per kilogram of polymer, or that there is a content of neutral or weakly acidic hydrophilic groups in the more shrinkable which is greater by 3 to 10% than that in the less shrinkable polymer, or that the concentration of polymer in the spinning solution which is to provide the more shrinkable polymer is lower by 0À3-5% than that in the spinning solution which is to provide the less shrinkable polymer, or that the molecular weight of the more shrinkable polymer is lower than that of the less shrinkable polymer by at least 0À1 unit when measured in terms of intrinsic viscosity in dimethylformamide at 30‹ C. Finally, the difference in the degree of irreversible swelling may be brought about by difference in the comonomer content of the polymers.