Patent ID: 10138593

Abstract:
Sizing agent-coated carbon fibers includes: a sizing agent including an aliphatic epoxy compound (A) and at least containing an aromatic epoxy compound (B1) as an aromatic compound (B); and carbon fibers coated with the sizing agent, wherein the sizing agent-coated carbon fibers have an (a)/(b) ratio of 0.50 to 0.90 where (a) is a height (cps) of a component at a binding energy (284.6 eV) assigned to CHx, C—C, and C═C and (b) is a height (cps) of a component at a binding energy (286.1 eV) assigned to C—O in a C1s core spectrum of a surface of the sizing agent applied onto the carbon fibers analyzed by X-ray photoelectron spectroscopy using AlKα1,2 as an X-ray source at a photoelectron takeoff angle of 15°.