| 摘要 |
PURPOSE:To obtain the title product providing flexural fatigue resistance, providing transmission belt having high strength and high elongation by making twisted yarn from polyacrylonitrile-based carbon yarn subjected to specific surface treatment and providing the twisted yarn with a thermoplastic polyurethane resin. CONSTITUTION:First, polyacrylonitrile-based carbon yarn is subjected to electrolytic surface treatment in a solution of nitric acid (nitrate)-based electrolyte. Then the fiber bundle of carbon yarn subjected to electrolytic surface treatment is preliminarily twisted, plural twisted yarns are properly arranged and twisted. Successively the prepared twisted yarn is provided with a solution or dispersion of a thermoplastic polyurethane resin, dried and shaped by a die to give the objective product which comprises the twisted yarn of carbon yarn coated with the thermoplastic polyurethane resin not to expose the carbon yarn to the outer peripheral part, has 8-30wt.% based on the whole amounts of thermoplastic polyurethane and a ratio of apparent density to true density of >=0.65. |
