| 摘要 |
1477793 Carbon fibres JAPAN EXLAN CO Ltd 7 Feb 1975 [15 Feb 1974] 5394/75 Heading C1A Carbon fibres are made by spinning acrylic fibres in a water-swollen state from an inorganic solvent solution of an acrylonitrile homopolymer or copolymer containing at least 85 mole percent acrylonitrile and having a degree of orientation of at least 50% and a water content of 5-150%, drying the fibres at a temperature below 70‹ C to reduce the water content to below 4% thus devitrifying the fibres and then carbonizing the dried and devitrified fibres. The dried fibres are preferally thermally stabilized by heating in an oxidizing atmosphere, e.g. air at 150- 400‹ C prior to carbonization in a non-oxidizing atmosphere, e.g. N 2 at 800-2000‹ C. The carbon fibres may be subsequently graphitized in a non-oxidizing atmosphere at 2000-3500‹ C. The acrylic fibres may be spun from a solution of the acrylonitrile polymer in a thiocyanate, e.g. Li, K, Na or HN 4 <SP>+</SP>, zinc chloride or perchlorate or a concentrated solution of an inorganic acid such as H 2 SO 4 or HNO 3 . The solution preferably contains 5-30% by weight of the polymer and is preferably spun into air or an inert, non-coagulating gas then led into a coagulating bath. The coagulated fibres are preferably washed and stretched from 3-25 times their original length before drying. The drying is preferably performed at below 60‹ C to produce fibres of water content less than 2%.
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