Mitsui Minings & Melting Co., Ltd.

Kyushu University

Yasuhide Yamaguchi

Takao Hayashi

Yoshiharu Toshima

Hiroyuki Shimamura

Takayuki Araki

Yunosuke Nakahara

Kiyoshi Yamagishi

Kazuo Moriya

Kenji Suzuoka

Akiko Sugimoto

Takahito Asanuma

Mikimasa Horiuchi

Masahiko Nakano

Masatoshi Yamazaki

Ryutaro Kuroda

Yukio Nobe

Yutaka Anzai

Yasuhiro Kawase

Osamu Ohnishi

Syuhei Kurokawa

Tadashi Hasegawa

The present invention provides an abrasive material capable of polishing difficult-to-polish silicon carbide at a high degree of surface precision. The present invention relates to an abrasive material including manganese dioxide particles having a non-needle-like shape possessing a ratio of the longitudinal axis to the transverse axis of the particles observed with a scanning electron microscope of 3.0 or less. The abrasive material is preferable if the average particle size Dof the longitudinal axis of the observed particles is 1.0 &#x3bc;m or less, and if the particle size Dof the volume-based cumulative fraction of 50% in laser diffraction/scattering particle size distribution measurement is 2.0 &#x3bc;m or less.

Abrasive material

Provided is an exhaust-gas-purification catalyst carrier that contains a ceria-zirconia complex oxide having a pyrochlore phase and a novel exhaust-gas-purification catalyst carrier that exhibit excellent OSC performance at any temperature region of a low temperature (around 400&#xb0; C.) and a high temperature (around 800&#xb0; C.). Proposed is the exhaust-gas-purification catalyst carrier containing a ceria-zirconia complex oxide which has a pyrochlore phase and is 7.0 m/g or more in specific surface area and in the range of 100 &#x212b; to 700 &#x212b; in crystallite size.

Exhaust-gas-purification catalyst carrier

Nickel powder includes, on the basis of the total number of particles, not less than 10% of particles whose particle size is not less than 1.2 times the average particle size, as determined by the SEM observation; and not less than 10% of particles whose particle size is not more than 0.8 times the average particle size, as determined by the SEM observation. The nickel powder can be prepared by, for instance, precipitating nickel particles from an aqueous solution containing a nickel salt and a hydrazine reducing agent, without forming any hydroxide of nickel as an intermediate. A conductive paste containing the nickel powder can be applied onto an internal or external electrode for electronic parts.

Nickel powder, method for preparing the same and paste for use in making electrodes for electronic parts

Nickel powder and conductive paste

The composite nickel fine powder includes surface-oxidized nickel fine particles and at least one member selected from the group consisting of oxides and complex oxides of at least one metal element having an atomic number ranging from 12 to 56 or 82 and belonging to Group 2 to 14 of the Periodic Table on the surface of the surface-oxidized nickel fine particles.

Composite nickel fine powder and method for preparing the same

The promoter includes (A) particulate aluminum oxide and (B) a double oxide of (i) cerium and (ii) at least one member selected from the group consisting of zirconium, yttrium, strontium, barium and rare earth elements, supported on the particulate aluminum oxide. A solution of (i) a water-soluble salt of cerium and (ii) a water-soluble salt of at least one member selected from the group consisting of zirconium, yttrium, strontium, barium and rare earth elements is formed. Particulate aluminum oxide is added to the solution to form a dispersion. An aqueous solution of ammonium hydrogen carbonate is added to the dispersion to obtain particulate aluminum oxide coated with a reaction product. The particulate aluminum oxide coated with the reaction product is fired. Alternatively, an aqueous solution containing (i) the water-soluble salt of cerium and (ii) the water-soluble salt of the at least one member dissolved therein is adhered onto particulate aluminum oxide. The particulate aluminum oxide provided thereon with the aqueous solution adhered thereto is brought into contact with an aqueous solution of ammonium hydrogen carbonate to cause a reaction between these solutions and to thus deposit a reaction product on the particulate aluminum oxide. The particulate aluminum oxide with the reaction product deposit is fired.

Promoter for purifying internal engine exhaust and method for preparing the same

Nickel powder herein disclosed has an average particle size, as determined by the observation with SEM, of not more than 1 &mgr;m, a particle density of not less than 8.0 g/cm , and an average diameter of crystallites present in the nickel particles of not more than 550 &angst;. Moreover, a conductive paste for a multilayer ceramic capacitor comprises the foregoing nickel powder. The nickel powder and the conductive paste containing the same can control heat shrinkage while inhibiting any rapid oxidation and permit the production of a thin, uniform internal electrode for a multilayer ceramic capacitor without being accompanied by any crack formation and delamination during firing.

Composite nickel fine powder comprises metal nickel fine particles, at least one member attached to the surface of the fine particles and selected from the group consisting of oxides and double oxides containing at least one metal element selected from the group consisting of the Groups 2 to 14 of the Periodic Table and whose atomic number falls within the range of from 12 to 82, and a saturated or unsaturated fatty acid supported on the surface of the nickel fine particles provided thereon with the oxide and/or double oxide attached thereto. The composite nickel fine powder is excellent in resistance to heat shrinkage, has a high tap density, and has characteristic properties suitable for use as a material for making a conductive paste.

Composite nickel fine powder

Nickel fine powder comprises nickel and phosphorus dispersed in the nickel in an amount ranging from 0.01 to 2% by weight on the basis of the weight of the nickel and having a particle size of not more than 0.5 &mgr;m. The nickel fine powder can be prepared by a method comprising the step of reducing nickel hydroxide in the presence of phosphorus ions in such an amount that the molar ratio of phosphorus ions to nickel ions falls within the range of from 0.01 to 2.

Nickel fine powder and method for preparing the same

A zinc oxide fine particle-adhered composite material consists essentially of a substrate and zinc oxide fine particles adhered thereto. The composite material is characterized in that the zinc oxide fine particles deposited, from an aqueous medium, on the surface of the substrate are firmly adhered to the surface without using any binder and the zinc oxide fine particles are substantially exposed on the surface. The composite material is prepared by, for instance, a method which comprises the step of coming an aqueous suspension of zinc oxide fine particle in contact with a substrate to thus deposit the zinc oxide fine particles on the surface of the substrate. The composite material allows for the zinc oxide particles to sufficiently show their antibacterial, deodorizing, UV absorbing, photocatalytic, stain-proofing and purifying activities without any delay.

Composite material carrying zinc oxide fine particles adhered thereto

In a method for manufacturing forsterite single crystals containing tetravalent chromium as luminescent ions, the method which comprises the use of chromium dioxide or comprises the use of a sintered body obtained either by sintering in a non-reducing atmosphere chromium trioxide or a mixture of at least 30 wt. % of chromium trioxide with up to 70 wt. % of dichromium trioxide, together with other oxide materials for forsterite, or by firing in an oxidizing atmosphere a mixture of more than 70 wt. % of dichromium trioxide with less than 30 wt. % of chromium trioxide, together with other oxide materials for forsterite. This invention also relates to forsterite single crystals obtained by each of the above methods.

Forsterite single crystal and method for the manufacture of the same

A chrysoberyl solid laser host which comprises a chrysoberyl matrix doped with trivalent titanium ions for luminescence is described. This host ensures a lasing operation over a wide wavelength range and is highly producible and high in quality.

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Yamaguchi, Japan

Yasuhide Yamaguchi