Tosoh Corporation

Toru Tsuyoshi

Koji Tsukuma

Kenichi Takahashi

Isao Yamashita

Kohei Iwanaga

Masanori Kohgo

Masanori Ichida

Masanori Abe

Hidehiko Misaki

Shuji Takato

Kazuyuki Chiba

Taichi Arakawa

Provided are: an anode active material for a lithium ion secondary battery with which high initial efficiency and battery capacity can be maintained and excellent cycling characteristics are achieved; and a method for producing such an active material. The anode active material for a lithium ion secondary battery, the active material comprising a Si compound and a carbonaceous material or a carbonaceous material and graphite, is obtained by a method comprising the steps of:

Composite active material for lithium ion secondary batteries and method for producing same

The invention relates to the use of a sintered body obtained by subjecting a primary sintered body having a relative density of 95% or higher produced from a fine yttria-containing zirconia powder to HIP sintering at a temperature of 1,200-1,600&#xb0; C. and a pressure of 50 MPa or higher. This sintered body is either a sintered body which has a total light transmittance, as measured at a thickness of 0.5 mm, of 43% or higher and a three-point bending strength of 1,700 MPa or higher or a zirconia sintered body which has a total light transmittance, as measured at a thickness of 1 mm, of 40% or higher and a three-point bending strength of 500 MPa or higher and which combines high strength and total light transmission.

Zirconia sintered bodies with high total light transmission and high strength, uses of the same, and process for producing the same

A method for producing an orthodontic bracket is comprised of sintering a molded body of highly-pure alumina fine powder at a temperature of 1,200&#xb0; C. to 1,300&#xb0; C. to obtain a sintered body composed of crystals having a relative density of 96% to 99.5% and an average crystal grain size of at most 1 &#x3bc;m, and thereafter subjecting the sintered body to an HIP treatment at a temperature of 1,200&#xb0; C. to 1,350&#xb0; C., under a pressure of at least 50 MPa. Such an orthodontic bracket has high strength and high translucency, can be processed into a complicated shape, similar to that of a metal bracket, and maintains excellent translucency.

Process for producing an orthodontic bracket

An orthodontic bracket is comprised of a translucent ceramic containing at least 99.5 wt % of alumina, and having an absorption/scattering coefficient of at most 2.8 mmfor visible light at a wavelength of 550 nm and a bending strength of, at least 700 MPa. This bracket is obtained, for example, by sintering a molded body of highly-pure alumina fine powder at a temperature of from 1,200&#xb0; C. to 1,300&#xb0; C. to obtain a sintered body composed of crystals having a relative density of from 96% to 99.5% and an average crystal grain size of at most 1 &#x3bc;m, and thereafter subjecting the sintered body to an HIP treatment at a temperature of from 1,200&#xb0; C. to 1,350&#xb0; C. and under a pressure of at least 50 MPa. Such an orthodontic bracket has high strength and high translucency, can be processed into a complicated shape, similar to that of a metal bracket, and maintains excellent translucency.

Orthodontic bracket and process for producing the same

A powder of electrolytic manganese dioxide and a process for producing the same are disclosed. The powder has a maximum particle diameter of 100 &mgr;m or smaller, a content of 1 &mgr;m and smaller particles of lower than 15% by number, and a median diameter of from 20 to 60 &mgr;m, and which has a potential of 270 mV or higher in terms of the potential of a suspension of the powder in 40% aqueous KOH solution as measured using a mercury/mercury oxide reference electrode as a base.

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Sagamihara, Japan

Toru Tsuyoshi