Asahi Glass Company, Limited

Yoshihisa Beppu

Kazuo Sunahara

Hiroyuki Tomonaga

Tomohiro Sakai

Satoshi Kashiwabara

Katsuaki Miyatani

Kumiko Takahashi

Yuzuru Tanabe

Otojiro Kida

Hiroshi Usui

Iori Yoshida

Toshihiro Ishino

Yoshinori Kon

Osamu Miyahara

Shinji Kondoh

Mitsuru Horie

The present invention relates to a process for producing lithium iron phosphate particles, wherein the process has a step of obtaining a melt containing, as represented by mol % based on oxides, from 1 to 50% of LiO, from 20 to 50% of FeOand from 30 to 60% of PO; a step of cooling and solidifying the melt; a step of pulverizing the solidified product into a desired particle shape; and a step of heating the pulverized product in the air or under oxidizing conditions (0.21&#x3c;oxygen partial pressure&#x3c;1.0) at from 350 to 800&#xb0; C. to precipitate crystals of LiFe(PO)(0&#x3c;n&#x3c;3), in this order.

Process for producing lithium iron phosphate particles and method for producing secondary cell

To provide a process for producing ceria-zirconia solid solution crystal fine particles having high crystallinity, being excellent in uniformity of composition and particle size, having a small particle size and a high specific surface area and being excellent in heat resistance, and such solid solution crystal fine particles. A process comprises a step of obtaining a melt containing, as represented by mol % based on oxides, from 5 to 50% of (ZrO+CeO), from 10 to 60% of RO (wherein R is at least one member selected from the group consisting of Mg, Ca, Sr and Ba) and from 25 to 70% of BO, a step of quenching the melt to obtain an amorphous material, a step of heating the amorphous material at a temperature of from 550 to 1000&#xb0; C. to precipitate a ceria-zirconia solid solution crystal in the amorphous material, and a step of separating components other than the ceria-zirconia solid solution crystal from the obtained precipitates to obtain the ceria-zirconia solid solution crystal fine particles, in this order.

Ceria-zirconia solid solution crystal fine particles and their production process

Provided is a process for readily producing fine particles of a solid solution having a small particle size, comprising a solid solution of zirconia, ceria and a rare earth oxide in a desired composition, and being highly crystalline. The process for producing the fine particles of the solid solution comprises the following steps in the order named: obtaining a melt comprising, in terms of mol % on an oxide basis, from 5 to 50% ZrO, CeOand REO(where RE is at least one member selected from rare earth elements other than Ce) in total, from 10 to 50% RO (where R is at least one member selected from the group consisting of Mg, Ca, Sr, Ba and Zn), and from 30 to 75% BO; quenching the melt to obtain an amorphous material; heating the amorphous material to obtain precipitates containing crystals of a solid solution with ZrO, CeOand REO; and separating the crystals of the solid solution from the precipitates to obtain fine particles of the solid solution.

Process for producing fine particles of solid solution

A method for producing a glass substrate for a magnetic disk by polishing a circular glass plate, which comprises a step of polishing the principal plane of the circular glass plate by using a slurry containing a CeOcrystal powder, the CeOcrystal powder being obtained in such a manner that a melt containing CeOis quenched to obtain an amorphous material, and the amorphous material is subjected to heat treatment to obtain a CeOcrystals-precipitated amorphous material, which is subjected to acid treatment to separate and extract the CeOcrystal powder from the CeOcrystals-precipitated amorphous material.

Method for producing glass substrate for magnetic disk, and magnetic disk

To provide a process for producing CeOfine particles having high crystallinity, being excellent in uniformity of composition and particle size and having a small particle size, and a polishing slurry containing such fine particles. A process for producing CeOfine particles, which comprises a step of obtaining a melt containing, as represented by mol % based on oxides, from 5 to 50% of CeO, from 10 to 50% of RO (wherein R is at least one member selected from the group consisting of Mg, Ca, Sr and Ba) and from 30 to 75% of BO, a step of quenching the melt to obtain an amorphous material, a step of precipitating CeOcrystals from the amorphous material, and a step of separating the CeOcrystals from the obtained crystallized product, in this order. A polishing slurry containing from 0.1 to 20 mass % of such fine particles.

[object Object]

It is an object to provide fine particles of bismuth titanate having excellent dielectric characteristics, high crystallinity and a small particle diameter, and a process for their production. The object is accomplished by a process which comprises a step of obtaining a melt comprising, as represented by mol % based on oxides, from 23 to 72% of BiO, from 4 to 64% of TiOand from 6 to 50% of BO, a step of quickly quenching this melt to obtain an amorphous material, a step of crystallization of bismuth titanate crystals from the above amorphous material, and a step of separating the bismuth titanate crystals from the obtained crystallized material, in this order.

Process for producing fine particles of bismuth titanate

To provide a composition for forming a dielectric layer excellent in dielectric constant and withstand voltage properties, a MIM capacitor and a process for its production. A composition for forming a dielectric layer, which comprises fine particles of perovskite type dielectric crystal, glass frit, and a hydrolysable silicon compound or its oligomer, and a MIM capacitor comprising a substrate, and a bottom electrode layer, a dielectric layer having a structure such that fine particles of perovskite type dielectric crystal are dispersed in a silicon oxide matrix containing glass-forming ions and a top electrode, formed on the substrate in this order.

Composition for forming dielectric layer, MIM capacitor and process for its production

It is an object to provide a liquid composition for forming a thin film, with which a ferroelectric thin film having excellent characteristics can be prepared even by baking at a low temperature, and a process for producing a ferroelectric thin film using it. The above object is achieved by use of a liquid composition for forming a ferroelectric thin film, characterized in that in a liquid medium, ferroelectric oxide particles being plate or needle crystals, which are represented by the formula ABO3 (wherein A is at least one member selected from the group consisting of Ba, Sr, Ca, Pb, La, Kand Na, and B is at least one member selected from the group consisting of Ti, Zr, Nb, Taand Fe) and have a Perovskite structure and which have an average primary particle size of at most 100 nm and an aspect ratio of at least 2, are dispersed, and a soluble metal compound which forms a ferroelectric oxide by heating, is dissolved.

Liquid composition for forming ferroelectric thin film and process for producing ferroelectric thin film

A process for preparing a silicate porous product, which comprises a step of forming a clay mineral into a dispersion by means of a dispersant, a step of removing gases dissolved in the dispersion, a step of freezing the dispersion and drying it in its frozen state under reduced pressure, and a step of firing the dried product obtained by the drying.

Process for preparing silicate porous product

A fused-cast-alumina-zirconia-silica refractory consisting essentially of corundum crystals, baddeleyite crystals and a matrix glass phase and having a chemical composition comprising (a) from 30 to 70 wt % of Al.sub.2 O.sub.3, (b) from 20 to 59 wt % of ZrO.sub.2, (c) from 5 to 12 wt % of SiO.sub.2, (d) from 0.15 to 0.60 wt % of Na.sub.2 O, (e) from 0 to 0.50 wt % of K.sub.2 O, (f) from 0 to 0.40 wt % of Li.sub.2 O, (g) from 0.05 to 0.80 wt % of B.sub.2 O.sub.3, (h) from 0.05 to 0.80 wt % of P.sub.2 O.sub.5, and (i) from 0.05 to 0.50 wt % in total of at least one member selected from the group consisting of SnO.sub.2, ZnO, CuO and MnO.sub.2.

Fused-cast-alumina-zirconia-silica refractory, methods of making it and

High zirconia fused cast refractories which include as chemical components of refractories in weight %, 85 through 91% of ZrO.sub.2, 7.0 through 11.2% of SiO.sub.2, 0.85 through 3.0% of Al.sub.2 O.sub.3, 0.05 through 1.0% of P.sub.2 O.sub.5, 0.05 through 1.0% of B.sub.2 O.sub.3 and 0.01 through 0.12% of a summed amount of K.sub.2 O and Na.sub.2 O, wherein the weight % of K.sub.2 O is not smaller than the weight % of Na.sub.2 O.

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Yokohama, Japan

Yoshihisa Beppu