| 摘要 |
PURPOSE:To suppress orientation relaxing in flameproofing and obtain the titled precursor, having a specific strength, maximum draw ratio and maximum developing tension, by finally drawing fibers consisting of acrylonitrile, etc., heat-setting the drawn fibers and relaxing the fibers in, before and after the above-mentioned treatment. CONSTITUTION:A polymer, having at least 5.5g/d strength and containing >=90wt% acrylonitrile is spun, drawn and finally drawn to give a precursor, which is then subjected to heat-setting treatment at the maximum temperature of 150-220 deg.C and relaxed in, before and after the heat-setting treatment within the range of 3-10% to afford the aimed precursor, having 5.5-7g/d strength, 115-140% maximum draw ratio during residence in hot air at 240 deg.C for 2min and 0.3-0.4g/d maximum developing tension when treated in hot air at 240 deg.C for 2min and useful for carbon fibers.
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