BUNDLING AGENT FOR CARBON FIBER, BUNDLING AGENT-ATTACHED CARBON FIBER, AND CARBON FIBER-REINFORCED RESIN COMPOSITION EMPLOYING THE CARBON FIBER AS REINFORCING MATERIAL

摘要

PURPOSE:To provide the subject bundling agent having an improved carbon fiber- bundling property, giving carbon fiber-reinforced resin composite materials having improved mechanical characteristics and having good safety and accident-preventing property by compounding the aqueous emulsion of a polyurethane resin comprising specific compositional components and having a specified crosslinking density. CONSTITUTION:A polyurethane resin having a crosslinked site density of 0.02-0.06 site/100 atomic weight is emulsified in water to provide a bundling agent which is applied to carbon fibers in an amount of 0.5-10wt.% to highly bundle the carbon fibers. The polyurethane resin is prepared from (A) one kind or more of polyols or polyamines having a mol. wt. of =10000 and containing active hydrogen atoms comprising two or more hydroxyl groups at the end of the molecule, (B) one kind or more of polyisocyanates, (C) a compound having an active hydrogen atom capable of reacting the NCO group and forming a salt (e.g. a glycolic acid or a compound having a sulfon ic acid group) and (D) a compound capable of forming a salt with the compound C.