SIZING AGENT FOR CARBON FIBER, WATER DISPERSION THEREOF, CARBON FIBER, AND CARBON FIBER-REINFORCED COMPOSITE MATERIAL

摘要

PROBLEM TO BE SOLVED: To provide a sizing agent for a carbon fiber, which provides the carbon fiber with excellent matrix resin impregnability and obtains a carbon fiber having stable process passage properties and property improving effect. SOLUTION: The sizing agent for a carbon fiber comprises≥50 mass% of a mixture composed of (A) 20-80 mass% of a compound that contains at least one epoxy group in the molecule and has a surface free energy value EAat 125°C of 21-24 mJ/m2, (B) 10-50 mass% of a compound that contains at least one epoxy group in the molecule and has a surface free energy value EBat 125°C of 28-34 mJ/m2and (C) 10-40 mass% of a compound that contains at least one epoxy group in the molecule and has a surface free energy value ECat 125°C of 37-42 mJ/m2. COPYRIGHT: (C)2009,JPO&INPIT