| 摘要 |
<p>1,161,939. Polyacrylonitrile filaments. JAPAN EXLAN CO. Ltd. 25 Aug., 1967 [27 Aug., 1966], No. 39327/67. Heading B5B. Filaments of polyacrylonitrile, or a copolymer of at least 91% by weight of acrylonitrile with one or more ethylenically unsaturated monomers copolymerizable therewith, having a high degree of whiteness and being well compacted and densified, are prepared by subjecting wet spun filaments to washing, stretching, and orientation steps, these operations being carried out without drying the filaments and while they are still in a swollen gel state, and then subjecting the filaments containing at least 40% of their weight of water, to a wet-heat relaxation treatment in hot water or steam at 60-100‹ C. in the non-tensioned state, and then drying the thus treated filaments under temperature and humidity conditions lying on or within the boundaries of the area HIJK of Fig. 1. Preferably the relaxation treatment is carried out for a period of from 5 to 15 minutes. Examples of monomers copolymerizable with acrylonitrile are methyl acrylate, vinyl acetate, allyl sulphonic acid, vinylidene chloride, and diethylaminoethylmethacrylate.</p> |
