Showa Denko K.k.

So Miyaishi

Satoshi Iinou

Shinichiro Tomikawa

Yasushi Kuroda

Yasuhiro Hosogi

Ding Li

Satoshi Yamaoka

Kazuaki Takano

A precursor of an alumina sintered compact including aluminum, yttrium, and at least one metal selected from iron, zinc, cobalt, manganese, copper, niobium, antimony, tungsten, silver, and gallium. The aluminum content is 98.0% by mass or more as an oxide (AlO) in 100% by mass of the precursor of an alumina sintered compact; the yttrium content is 0.01 to 1.35 parts by mass as an oxide (YO) based on 100 parts by mass of the content of the aluminum as an oxide; the total content of the metals selected from the foregoing group is 0.02 to 1.55 parts by mass as an oxide based on 100 parts by mass of the content of aluminum as an oxide; and the aluminum is contained as &#x3b1;-alumina. Also disclosed is an alumina sintered compact, and a method for producing an alumina sintered compact and for producing abrasive grains.

Precursor of alumina sintered body, method for producing alumina sintered body, method for producing abrasive grains, and alumina sintered body

An alumina sintered body including an inner layer in which alumina crystal grains contained have an average aspect ratio of 1.0 to 2.0 and an outer layer which covers at least a part of the inner layer from outside and in which alumina crystal grains contained have an average aspect ratio of more than 2.0, the alumina sintered body being free from silicon except unavoidable impurities.

Alumina sintered body, abrasive grain, and grinding wheel

A method for producing an alumina sintered body, including: a step of applying an alkaline earth metal compound onto a surface of an alumina raw material which is an unsintered alumina compact or an alumina sintered body; and a step of subjecting the alumina raw material to which the alkaline earth metal compound has been applied to heat treatment at a temperature of 1200&#xb0; C. or more for 5 minutes or more and 300 minutes or less.

Method for producing alumina sintered body

To provide an alumina sintered body, abrasive grains, and a grinding wheel having high hardness and excellent wear resistance. An alumina sintered body comprising: an inner layer comprising alumina crystal grains; and an outer layer covering at least a part of the inner layer from outside, having a higher content of an alkaline earth metal than the inner layer, and comprising alumina crystal grains, wherein the content of the alkaline earth metal in the outer layer is 1.0 to 30.0 mass % in terms of oxide, the alumina sintered body being free from silicon except unavoidable impurities.

The Cu- and Ti-containing composition of the present invention contains titanium oxide having a rutile-type titanium oxide content of 15 mol % or more, and at least one divalent copper compound represented by the following formula (1). The Cu- and Ti-containing composition production method of the present invention is characterized by including stirring a mixture containing titanium oxide having a rutile-type titanium oxide content of 15 mol % or more, a divalent copper compound raw material represented by formula (2), water, and an alkaline compound, to thereby cause precipitation. The composition of the present invention exhibits excellent anti-viral property under light and in the dark, and excellent organic compound decomposition activity under light.

Copper-and-titanium-containing composition and production method therefor

The Cu- and Ti-containing composition of the present invention contains titanium oxide including rutile-crystal-type titanium oxide, and a divalent copper compound, wherein the rutile-crystal-type titanium oxide exhibits the most intense diffraction peak attributed to rutile-type titanium oxide having a full width at half maximum of 0.65&#xb0; or less, in a Cu&#x2014;K&#x3b1; line X-ray diffraction pattern, which is obtained by plotting intensity of diffraction line with respect to diffraction angle 2&#x3b8;. The composition exhibits excellent anti-viral property under light and in the dark, and excellent organic compound degradability under light.

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Kawasaki, Japan

So Miyaishi