Showa Denko K.k.

Showa Denko Kabushiki Kaisha

Tomoyuki Masuda

Kousuke Shioi

Hiroshi Saegusa

Katsura Ito

Tadashi Hiraiwa

Yutaka Yamauchi

Naoki Bessho

Nobuhiko Ohara

Fumio Imai

Hidefumi Nakano

Hiroshi Mizukami

A cerium-based abrasive that achieves a high polishing rate and suppresses the occurrence of surface defects such as scratches and pits and the deposition of the abrasive particles on the polished surface in surface polishing of glass substrates or the like, at low cost with a high production efficiency. The cerium-based abrasive includes a cubic composite rare earth oxide and a composite rare earth oxyfluoride, containing 95.0 to 99.5 mass % of total rare earth elements in terms of oxides, containing 54.5 to 95.0 mass % of cerium in terms of oxide, 4.5 to 45.0 mass % of lanthanum in terms of oxide, and 0.5 to 2.0 mass % of neodymium in terms of oxide relative to the total rare earth elements in terms of oxides, containing 0.5 to 4.0 mass % of fluorine atoms, and containing 0.001 to 0.50 mass % of sodium atoms relative to the total rare earth elements in terms of oxides.

Cerium-based abrasive material and process for producing same

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

By providing an abrasive having a ratio of volume-cumulative (95%) average particle size (D95) to volume-cumulative (50%) average particle size (D50) (D95/D50) falling within a range of 1.2 to 3.0 or an abrasive having a volume-cumulative (95%) average particle size (D95) falling within a range of 0.1-1.5 &#x3bc;m and containing coarse particles having a size more than 10 times the volume-cumulative (50%) average particle size (D50) in an amount, based on the total mass of all the particles, of 1 mass % or less, there can be provided an abrasive, an abrasive slurry, a method for producing an abrasive, and a polishing method which attain, during accurate polishing of substrates such as electronics substrates, a high removal rate and a high-quality surface; i.e., a surface having a high flatness, low surface roughness, and substantially no microscratches or micropits.

Polishing particle and method for producing polishing particle

Cubic boron nitride composite particles containing hard microparticles dispersed in cubic boron nitride particles. The hard microparticles have an average particle size of about 10 nm to about 10 &mgr;m and a particle size equal to or smaller than one-third of the particle size of any of the cubic boron nitride particles, and the amount of the hard microparticles dispersed in the cubic boron nitride particles is from about 1% to about 50% by volume.

Cubic boron nitride composite particle

An abrasive composition for polishing glass, containing a basic salt of magnesium. Also disclosed is a method for polishing glass with the abrasive composition.

Composition for polishing glass and polishing method

hBN is converted to cBN by keeping it under temperature and pressure conditions within the range of stability of cubic boron nitride, in the presence of at least one compound selected from carbides of alkali metals and alkaline earth metals, or in the presence both of at least one compound selected from carbides of alkali metals and alkaline earth metals and of at least one compound selected from amides and imides of alkali metals and alkaline earth metals.

Growing community of inventors

Nagano, Japan

Tomoyuki Masuda