Abstract: 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: mixing a Si compound, a carbon precursor, and, as appropriate, graphite powder; performing granulation/compaction; pulverizing the mixture to form composite particles; firing the composite particles in an inert gas atmosphere; and subjecting the pulverized and conglobated composite powder or the fired powder to air classification.

Abstract: 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: mixing a Si compound, a carbon precursor, and, as appropriate, graphite powder; performing granulation/compaction; pulverizing the mixture to form composite particles; firing the composite particles in an inert gas atmosphere; and subjecting the pulverized and conglobated composite powder or the fired powder to air classification.

Abstract: 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° 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.

Abstract: 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° C. to 1,300° 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 ?m, and thereafter subjecting the sintered body to an HIP treatment at a temperature of 1,200° C. to 1,350° 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.

Abstract: 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 mm?1 for 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° C. to 1,300° 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 ?m, and thereafter subjecting the sintered body to an HIP treatment at a temperature of from 1,200° C. to 1,350° 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.

Abstract: 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° 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.

Abstract: 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° C. to 1,300° 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 ?m, and thereafter subjecting the sintered body to an HIP treatment at a temperature of 1,200° C. to 1,350° 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.

Abstract: Provided is an orthodontic bracket with high strength and high translucency, which can be processed into a complicated shape, which can be made in a shape closer to that of a metal bracket, and which maintains excellent translucency. The 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 mm?1 for 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 to 1,300° 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 ?m, and thereafter subjecting the sintered body to an HIP treatment at a temperature of from 1,200 to 1,350° C. and under a pressure of at least 50 MPa.

Abstract: 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.

Abstract: 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.