Toda Kogyo Corporation

Toda Kogyo Cororation

Yoshiro Okuda

Tosiharu Harada

Akio Mishima

Mamoru Tanihara

Hideaki Sadamura

Kenji Okinaka

Tomoyuki Imai

Norimichi Nagai

Yasutaka Ota

Kohji Mori

Hirofumi Kawasaki

Katsunori Fujimoto

Akira Mukaizaka

Kazuyuki Hayashi

Hiroko Morii

Keisuke Iwasaki

Akihisa Kajiyama

Tatsuya Nakamura

Mitsuaki Hatatani

A process for producing lithium-cobalt oxide, comprises: mixing cobalt oxide having a BET specific surface area of 30 to 200 m.sup.2 /g or an average particle size of not more than 0.1 .mu.m, with a lithium compound; and calcining the obtained mixture at a temperature of 500 to 850.degree. C. Such a process for producing lithium-cobalt oxide particles is useful especially as a cathode active substance for lithium ion batteries, which particles can be produced by calcination in a short time, and have a narrow particle size distribution and a uniform small particle size.

Process for producing lithium-cobalt oxide

Rectangular parallelopipedic lepidocrocite particles of the present invention have a minor axial diameter of 0.045 to 0.5 .mu.m, a major axial diameter of 0.05 to 1.0 .mu.m, and a thickness of 0.001 to 0.3 .mu.m, which are individual. Such rectangular parallelopipedic lepidocrocite particles according to the present invention are firstly used as a coloring pigment for paints, resin moldings, printing ink, road asphalt, cosmetics, etc., and secondly used as a non-magnetic material for non-magnetic undercoat layers which are formed on non-magnetic substrates which constitute a substrate for magnetic recording media, and which have an excellent surface smoothness and a high strength.

Rectangular parallelopipedic lepidocrocite particles and magnetic

Disclosed herein are spindle-shaped magnetic iron based alloy particles containing at least one selected from the group consisting of Ni, Al, Si, P, Co, Mg, B and Zn, which have a particle length of 0.05 to 0.40 .mu.m, a crystallite size of 110 to 180 .ANG., a specific surface area of 30 to 60 m.sup.2 /g, a coercive force of 1,300 to 1,700 Oe and a saturation magnetization (.sigma.s) of not less than 100 emu/g and a process for producing the same.

Spindle-shaped magnetic iron based alloy particles and process for

Spindle-shaped magnetic iron based alloy particles

Plate-like magnetite particles, plate-like maghemite particles and the processes for producing these particles are herein disclosed. The plate-like magnetite particles and the plate-like maghemite particles provided according to the present invention are fine plate-like particles which are poreless and non-sintered as the plate-like magnetite particles are produced directly from an aqueous solution and these plate-like magnetite particles are oxidized by heating to produce the plate-like maghemite particles. Therefore, these particles can be filled to a high density in a vehicle or resin, have good dispersibility and orientability and are also high in a degree of particle contact, so that they are suited for use as electromagnetic wave absorbing and shielding material, magnetic material for magnetic recording, black or brown pigment for paints and colorant for rubber and plastic products.

Process for producing plate-like magnetite particles and plate-like

Disclosed herein is acicular ferromagnetic alloy particles for magnetic recording, containing Si, Cr, Ni and P and optionally Mg impregnated with phosphorus compound and silicon compound and process for producing the same.

Acicular ferromagnetic alloy particles for magnetic recording and

Acicular ferromagnetic alloy particles doped with silicon, chromium and nickel and optionally magnesium and a process for producing said particles comprising heating at 300.degree. to 500.degree. C. under reducing atmosphere acicular particles of .alpha.-iron(III) oxide hydroxide doped with silicon, chromium and nickel and optionally magnesium or acicular particles of .alpha.-ferric oxide doped with silicon, chromium and nickel and optionally magnesium obtained by dehydrating the acicular particles of .alpha.-iron(III) oxide hydroxide doped with silicon, chromium and nickel and optionally magnesium are disclosed herein.

Acicular ferromagnetic alloy particles and process for producing said

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Hiroshima, Japan

Yoshiro Okuda