GRAPHITIZED SHORT FIBERS AND COMPOSITION THEREOF

摘要

Pitch-based graphitized short fibers formed from mesophase pitch as a raw material, the fibers having an average fiber diameter of 5-20 µm, a percentage of fiber diameter dispersion to the average fiber diameter, CV value, of 8-15%, a number-average fiber length of 20-500 µm, and a crystallite size in the growth direction of the hexagonal net plane, La, of 30 nm or larger.  When an end of the filler is examined with a transmission electron microscope, the graphene sheets are closed.  When examined with a scanning electron microscope, the surface is substantially flat.  The fibers have an R value in the range of 0.01 to 0.07, the value being the relative-intensity ratio between the intensity of a Raman band around 1,360 cm-1 (ID) and the intensity of a Raman band around 1,580 cm-1 (IG), (ID)/(IG), determined by laser Raman spectroscopy.  The fibers can be incorporated into a rubber composition in a large amount without inhibiting the curing of the composition.