SIZING-AGENT-COATED CARBON FIBERS, PROCESS FOR PRODUCING SIZING-AGENT-COATED CARBON FIBERS, CARBON-FIBER-REINFORCED COMPOSITE MATERIAL, AND PROCESS FOR PRODUCING CARBON-FIBER-REINFORCED COMPOSITE MATERIAL

摘要

Sizing agent coated carbon fibers obtained by coating carbon fibers with a sizing agent comprising at least one of (A) to (C) in a total amount of 80 mass% or more with respect to the whole sizing agent, the carbon fibers each having a surface layer which has a thickness of 10 nm or larger and has an oxygen content of 4% or higher with respect to all the elements, wherein when the sizing agent coated carbon fibers are subjected three times to a 10-minute ultrasonic treatment in an acetone solvent, then the amount of the remaining sizing agent is 0.1-0.25 parts by mass per 100 parts by mass of the sizing agent coated carbon fibers. (A) At least one polymer selected from the group consisting of polyimides, polyetherimides, and polysulfones (B) A compound having a terminal unsaturated group and a polar group in the molecule (C) A polyether-type aliphatic epoxy compound and/or a polyol-type aliphatic epoxy compound which each have an epoxy equivalent of 250 g/eq or less and have two or more epoxy groups in the molecule