To provide a high bulk density powder of a fine carbon fiber having improved dispersibility and kneadability in forming a composite of a polymer and the powder, and giving a composite having excellent processability, and excellent in development of functions such as electrical conductivity, thermal conductivity, sliding property and reinforcing effect, and provide a method for producing the powder in high efficiency.

The high bulk-density powder of the fine carbon fiber is produced by applying an impact compression stress to the fine carbon fiber, in which a graphite-net plane consisting of carbon atoms alone forms a campanulate structural unit comprising a closed head-top part and a body-part with opened lower-end, where the angle θ formed by the generatrix of the body-part and the fiber axis is 0°<θ<15°, the 2 to 30 campanulate structural units are stacked sharing the central axis to form an aggregate, and several to several tens of the aggregates are connected in head-to-tail style.

COPYRIGHT: (C)2011,JPO&INPIT