Showa Denko K.k.

Showa Denko Kabushiki Kaisha

Tadashi Hiraiwa

Tetsuo Hatanaka

Fumiyoshi Ono

Kunihiro Miyazaki

Mitsuru Hasegawa

Eizi Ando

Yoshitaka Kimura

Yuji Furuta

Tomoyuki Masuda

Naoki Bessho

Norimichi Aoki

Minoru Matsukura

Shoichi Imai

The present invention provides a cerium oxide-based abrasive ensuring high removal rate, less generation of scratches, high-precision polished surface with small surface roughness, and a safe, simple and low-cost production process. Further, the present invention provides a method for producing such an abrasive. The method of the present invention comprises (a) adding a precipitant to an aqueous cerium-containing light rare-earth salt solution to precipitate a light rare-earth salt, thereby obtaining a first slurry containing a light rare-earth salt particle; (b) adding a fluorinating agent to a slurry containing a light rare-earth salt particle to react the light rare-earth salt with the fluorinating agent, thereby obtaining a second slurry containing a light rare-earth fluoride particle; (c) mixing the first slurry and the second slurry to obtain a mixed slurry; and (d) drying and firing the mixed slurry, and a cerium oxide-based abrasive obtained by this method. The abrasive of the present invention is produced by the method of the present invention.

Cerium oxide-based abrasive, and production method and use thereof

Fused alumina particles are covered with a coating of aluminum titanate which is formed by applying a Ti-containing compound to the surface of the fused alumina particles and firing the same to cause a reaction between the Ti-containing compound and the alumina.

Coated fused alumina particles and production process thereof

Sintered alumina abrasive grain and abrasive products

An abrasive grain for use as a grinding material comprising alpha-alumina crystal particles substantially smaller than 0.5 microns, solidly dissolved with at least one of Ti, Mn, V, Ga, Zn and Rh, and with an a-axis length of the hexagonal unit cell of the alpha-Al.sub.2 O.sub.3 from 4.75892 to 4.76340 angstroms when measured by a powder X-ray diffraction method, and a density of more than 90% of the theoretical value, and an abrasive grain for a grinding material, comprising alpha-alumina crystal particles substantially less than 0.5 microns, solidly dissolved with at least one of Mg, Ni and Co, and with an a-axis length of the hexagonal unit cell of the alpha-Al.sub.2 O.sub.3 from 4.75930 to 4.76340 .ANG. when measured by a powder X-ray diffraction method, and a density of more than 90% of the theoretical value, and further, a grinding wheel and coated cloth manufactured from these abrasive grains.

Abrasive grain and manufacture for the same

Alumina-based ceramics materials, abrasive materials and method for the

An abrasive grain for use as a grinding material characterized by alpha-corundum crystal particles substantially smaller than 0.5 micron, solidly dissolved with at least one element out of Ti, Mn, V, Ga, Zn and Rh, and with an a-axis length of the hexagonal unit cell of the alpha-Al.sub.2 O.sub.3 at 4.75892 to 4.76340 angstrom when measured by a powder X-ray diffraction method, and a density of more than 90% of the theoretical value, and an abrasive grain for a grinding material, characterized by alpha-corundum crystal particles substantially less than 0.5 micron, solidly dissolved with at least one element out of Mg, Ni and Co, and with an a-axis length of the hexagonal unit cell of the alpha-Al.sub.2 O.sub.3 at 4.75930 to 4.76340 A when measured by a powder X-ray diffraction method, and a density of more than 90% of the theoretical value, and further, a grindstone and grinding cloth manufactured that these abrasive grains.

Abrasive grain and method for manufacturing the same

A composition for use in forming a hard tissue substitute comprising (A) a powder ingredient mainly comprised of Ca.sub.n+2 (PO.sub.4).sub.2 O.sub.n-1, where n is from 1.9 to 4.9 and (B) an aqueous solution of an organic acid, preferably of the TCA cycle, or a polymer of an organic acid. This composition has a good affinity with living organisms, a high compressive strength, and a low disintegration rate.

Hard tissue substitute composition

Mullite of high purity is obtained by neutralizing an aqueous solution containing a basic aluminum salt and colloidal silica thereby causing formation of a precipitate in the aqueous solution, and subsequently heating the precipitate.

Method for production of mullite of high purity

From a composition of a fine powder and water, a fine powder minimally susceptible of agglomeration is obtained by a method which comprises adding to the composition of a fine powder and water a water-insoluble organic solvent at least in an amount enough for consequently forming an azeotropic composition with respect to the amount of the water involved, converting the resulting mixed liquid into a W/O type emulsion, and removing the water and the organic solvent from the emulsion.

Growing community of inventors

Shiojiri, Japan

Tadashi Hiraiwa