Processes for producing coke, artificial graphite and carbon material for negative electrode of non-aqueous solvent type secondary battery and pitch composition used therefor

A process for producing a carbon material for a negative electrode of a non-aqueous solvent type secondary battery, comprising:

• (1) mixing 100 parts by weight of mesophase pitch which is produced by polymerizing a condensed polycyclic hydrocarbon or a substance containing the condensed polycyclic hydrocarbon in the presence of hydrogen fluoride-boron trifluoride, with 10 to 1,000 parts by weight of coal tar pitch which contains substantially no quinoline insolubles (QI) to produce a pitch composition having an optically anisotropic content of 1 to 99% by volume,
• (2) further mixing 1 to 30 parts by weight of sulfur per 100 parts by weight of the pitch composition obtained in step (1),
• (3) heat-treating the pitch composition obtained in step (2) at a temperature of 500° C. or higher,
• (4) pulverizing the coke produced in step (3) to provide a coke powder, and
• (5) graphitizing the coke powder at a temperature of 2000° C. or higher to form a graphite powder adapted to be used for the carbon material for the negative electrode of the non-aqueous solvent type secondary battery.