Coated acicular fine particulate materials, processes for preparing same and use thereof

摘要

PCT No. PCT/JP94/00242 Sec. 371 Date Oct. 18, 1994 Sec. 102(e) Date Oct. 18, 1994 PCT Filed Feb. 17, 1994 PCT Pub. No. WO94/19276 PCT Pub. Date Sep. 1, 1994An acicular fine particulate material which is coated with a compound containing at least one element selected from among elements of Groups III and IV of the Periodic Table in Periods 5 and 6, the acicular fine particulate material being one of (i) an acicular fine particulate material containing iron carbide, (ii) an acicular fine particulate material containing iron carbide, metallic iron and carbon, and (iii) an acicular fine particulate metallic iron containing carbon, is prepared by a promoted reduction reaction while being effectively prevented from sintering and consequently affords magnetic recording media having a high recording density.