| abstract |
A carbon fiber coated with a sizing agent is provided. This carbon fiber exhibits excellent adhesion to a matrix resin, ensures excellent stability of composite physical properties of a prepreg even after long-term storage, and is excellent in high-order processability. A process for producing the carbon fiber coated with a sizing agent, a prepreg, and a carbon fiber reinforced composite material are also provided. A carbon fiber coated with a sizing agent which comprises (A) an aliphatic epoxy compound and (B) an aromatic compound that contains (B1) an aromatic epoxy compound as the essential component, characterized in that the (a)/(b) ratio is 0.50 to 0.90 wherein (a) is the height (cps) of the peak at a binding energy of 284.6eV assignable to CH x, C-C and C=C in the C 1S core spectrum as determined by subjecting the surface of the sizing agent to X-ray photoelectron spectroscopy using AlKα 1.2 as the X-ray source at a photoelectron emission angel of 15°, and (b) is the height (cps) of the peak at a binding energy of 286.1eV assignable to C-O therein. |