SIZING AGENT FOR CARBON FIBER, SIZING OF CARBON FIBER, SIZING-TREATED CARBON FIBER, SHEETS FROM THE SIZED CARBON FIBER, AND FIBER-REINFORCED COMPOSITE MATERIAL

摘要

PROBLEM TO BE SOLVED: To obtain a sizing agent for carbon fiber that shows good impregnation, when an epoxy resin is used as a matrix resin, needless to say; further even when the matrix resin is a radically polymerized resin, and shows excellent adhesion. SOLUTION: A sizing agent mainly comprising a compound represented by formula I [A and B are each an organic residue bearing one functional group selected from vinyl, (meth)acryloyl, (alicyclic)epoxy, carboxyl and phenolic hydroxyl; X is a hydrocarbon group represented by formulas II, III, IV or the like (R is H or an alkyl; n is 0-12)] is dissolved or dispersed in water and the solution or dispersion is applied to carbon fiber in an amount of 0.1-5 wt.% based on the fiber to form sheets of carbon fiber. This carbon fiber sheet is used as a reinforcing material to form fiber-reinforced resin composition thereby producing the objective carbon fiber-reinforced composite material.