| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a carbon fiber bundle which can be formed into a complicated shape by obtaining a base material having high isotropy through papermaking, and which shows high adhesiveness to thermoplastic resins, exerts good composite properties stably and is excellent in convergence properties and water dispersibility.SOLUTION: A method of producing a carbon fiber bundle comprises: immersing a carbon fiber bundle in a thermoplastic sizing bath containing 1.0-5.0 mass% of a thermoplastic sizing; subjecting the carbon fiber bundle to a drying step of heat-treating the carbon fiber bundle at 200-240°C to a weight loss ratio of the thermoplastic sizing adhered to the carbon fiber bundle of 30-70 mass%; and being adhered the thermoplastic sizing to the carbon fiber bundle in an amount of 0.3-2.5 mass%. The thermoplastic sizing contains a water-soluble polyurethane or a water-soluble polyamide and more specifically a thermoplastic material comprising 73.0-98.0 mass% of polyoxyalkylene units, 0.5-15.0 mass% of aromatic ester units and 1.5-10.0 mass% of aromatic urethane units.</p> |
