Patent ID: 11390720

Abstract:
Provided are a sizing agent coated carbon fiber bundle that has excellent mechanical characteristics when used as a carbon fiber reinforced composite material, as well as excellent ease of handling; a method for manufacturing the same; and a prepreg and carbon fiber reinforced composite material of excellent mechanical characteristics, employing the fiber bundle. The carbon fiber bundle is coated with a sizing agent that includes a polyether aliphatic epoxy compound having two or more epoxy groups per molecule and/or a polyol aliphatic epoxy compound or a non-water-soluble compound having a glass transition temperature of −100-50° C., wherein the sizing agent coated carbon fiber bundle is characterized in that the flatness ratio (width/thickness) of the carbon fiber bundle cross section is 10-150, and a two edge part/center part sizing agent deposition ratio, obtained by dividing the carbon fiber bundle in the width direction along the fiber direction into three equal parts by mass, and computing the ratio from the ratio of the mass of the sizing agent to the mass of the carbon fiber bundle in the center part and in both end parts, is 1.05-1.5.