Sizing agent for carbon fiber, aqueous dispersion thereof, carbon fiber treated by sizing sheet-form object comprising the carbon fiber, and carbon fiber-reinforced composite material

摘要

The present invention provides a sizing agent capable of imparting superior resin impregnation and adhesion with resin, and more particularly, a carbon fiber sizing agent that have satisfactory emulsification stability having stable process throughput and minimizes the changes over time in the sized carbon fibers. The carbon fiber sizing agent contains (A) a compound having at least one epoxy group per molecule, (B) an anionic surfactant having an ammonium ion as the counter ion, and (C) a nonionic surfactant wherein, the nonionic surfactant (C) is contained at {fraction (1/50)} to ½ (weight ratio) relative to the anionic surfactant (B).