Method for producing sizing agent-coated carbon fibers, and sizing agent-coated carbon fibers

Sizing agent-coated carbon fibers, in which 0.001 to 3 parts by mass of at least one or more tertiary amine compounds and/or tertiary amine salts (B1) with a molecular weight of 100 g/mol or higher of the following Formula (IX) are included with the sizing agent and are deposited on 100 parts by mass of carbon fibers,

• wherein a di- or higher functional epoxy compound (A1) selected from the group consisting of phenol novolac type epoxy resin, a cresol novolac type epoxy resin, bisphenol A diglycidyl ether, and tetraglycidyldiaminodiphenylmethane and/or a mono- or higher functional epoxy compound (A2) selected from the group consisting of sorbitol type polyglycidyl ether, glycidyl phthalimide, and urea modified epoxy resin are included in the sizing agent and deposited as component (A),
• wherein the tertiary amine compound and/or tertiary amine salt (B1) is mixed by 0.1 to 25 parts by mass per 100 parts by mass of the epoxy component (A),
• wherein the thickness of the sizing agent applied to the carbon fibers and dried is in a range from 2 to 20 nm,
• wherein a compound represented by the general formula (IX) has at least one or more branched structures and contains at least one or more hydroxyl groups;
• wherein R32 to R34 donate any one of a hydrocarbon group with 1 to 22 carbon atoms, a group containing a hydrocarbon with 1 to 22 carbon atoms and an ester structure, and a group containing a hydrocarbon with 1 to 22 carbon atoms and a hydroxyl group;
• and any one of R32 to R34 contains a branched structure represented by general formula (X) or (XI);
• wherein R35 and R36 denote any one of a hydrocarbon group with 1 to 22 carbon atoms, a group containing a hydrocarbon with 1 to 22 carbon atoms and an ester group, a group containing a hydrocarbon with 1 to 22 carbon atoms and a hydroxyl group, and a hydroxyl group;
• wherein R37 to R39 denote any one of a hydrocarbon group with 1 to 22 carbon atoms, a group containing a hydrocarbon with 1 to 22 carbon atoms and an ester structure, a group containing a hydrocarbon with 1 to 22 carbon atoms and a hydroxyl group, and a hydroxyl group.