Patents by Inventor Kohei Imai
Kohei Imai has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 10696022Abstract: A composite plate having a thickness of no more than 2 mm, and having laminated therein a zirconia sintered body, an adhesive layer, and a base material, the elasticity of the base material being no more than 100 GPa, and the apparent density of the composite plate being no more than 4.3 g/cm3.Type: GrantFiled: June 26, 2013Date of Patent: June 30, 2020Assignee: TOSOH CORPORATIONInventors: Isao Yamashita, Kohei Imai, Shoichi Yamauchi, Koji Tsukuma
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Patent number: 10682831Abstract: A composite plate has a thickness of 2 mm or less, which is obtained by laminating and closely fixing a zirconia sintered body and a fiber-reinforced plastic with each other, and the thickness ratio of the zirconia sintered body to the fiber-reinforced plastic is 0.01 to 1, and the apparent density of the composite plate is 4.3 g/cm3 or less. A composite plate has a thickness of 2 mm or less, which is obtained by laminating and closely fixing a zirconia sintered body and a fiber-reinforced plastic with each other, and the maximum roughness depth of the surface of the zirconia sintered body is 50 ?m or less per 1 cm2.Type: GrantFiled: December 5, 2013Date of Patent: June 16, 2020Assignee: TOSOH CORPORATIONInventors: Isao Yamashita, Kohei Imai, Shoichi Yamauchi, Koji Tsukuma
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Patent number: 9309157Abstract: A subject of the invention relates to providing a powder for a translucent zirconia sintered body which is necessary for the production of a zirconia sintered body having a high sintered-body density and high strength and giving an excellent sense of translucency, without conducting any special sintering, such as HIP sintering. The invention relates to a technique for obtaining, through normal-pressure sintering, a translucent zirconia sintered body characterized by comprising zirconia which contains 2-4 mol % yttria as a stabilizer and has an alumina content of 0.2 wt % or lower, and by having a relative density of 99.8% or higher and a total light transmittance, as measured at a thickness of 1.0 mm, of 35% or higher. It is preferred that a powder containing 0-0.2 wt % alumina with a particle diameter of 0.01-0.5 ?m, having a BET specific surface area of 5-16 m2/g and an average particle diameter of 0.3-0.7 ?m, and having a rate of sintering shrinkage in normal-pressure sintering (??/?T; g/cm3·° C.) of 0.Type: GrantFiled: August 29, 2014Date of Patent: April 12, 2016Assignee: TOSOH CORPORATIONInventors: Hiroyuki Fujisaki, Kiyotaka Kawamura, Kohei Imai
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Patent number: 9249056Abstract: A zirconia sintered body having not only high strength but also excellent aesthetic properties. A colored translucent zirconia sintered body, characterized by containing an iron compound and from 2 to 4 mol % of yttria, showing a lightness L* of from 51 to 80 in L*a*b* color system, and having a relative density of at least 99.80%. The colored zirconia sintered body preferably has a total light transmittance of at least 20% as measured at a sample thickness of 1 mm and with a D65 light source. The colored translucent zirconia sintered body has aesthetic properties equivalent to those of natural teeth and is particularly suitable for a zirconia sintered body to be used for dental applications, and further, suitable for a mill blank such as an artificial tooth material or the like, and an orthodontic bracket.Type: GrantFiled: July 27, 2012Date of Patent: February 2, 2016Assignee: TOSOH CORPORATIONInventors: Hiroyuki Fujisaki, Kiyotaka Kawamura, Kohei Imai
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Publication number: 20150283791Abstract: A composite plate has a thickness of 2 mm or less, which is obtained by laminating and closely fixing a zirconia sintered body and a fiber-reinforced plastic with each other, and the thickness ratio of the zirconia sintered body to the fiber-reinforced plastic is 0.01 to 1, and the apparent density of the composite plate is 4.3 g/cm3 or less. A composite plate has a thickness of 2 mm or less, which is obtained by laminating and closely fixing a zirconia sintered body and a fiber-reinforced plastic with each other, and the maximum roughness depth of the surface of the zirconia sintered body is 50 ?m or less per 1 cm2.Type: ApplicationFiled: December 5, 2013Publication date: October 8, 2015Applicant: TOSOH CORPORATIONInventors: Isao Yamashita, Kohei Imai, Shoichi Yamauchi, Koji Tsukuma
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Publication number: 20150174863Abstract: [Problem] To provide a composite plate comprising a zirconia sintered body and a base material, or a zirconia sintered body and a base material comprising at least one among a group includes strengthened glass, Bakelite, aluminum, and magnesium, said composite plate being capable of being suitably used in a case or a watch member, etc, for a mobile electronic device that is light weight and has excellent shock resistance and abrasion resistance. [Solution] A composite plate having a thickness of no more than 2 mm, and having laminated therein a zirconia sintered body, an adhesive layer, and a base material, the elasticity of the base material being no more than 100 GPa, and the apparent density of the composite plate being no more than 4.Type: ApplicationFiled: June 26, 2013Publication date: June 25, 2015Inventors: Isao Yamashita, Kohei Imai, Shoichi Yamauchi, Koji Tsukuma
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Publication number: 20140370453Abstract: A subject of the invention relates to providing a powder for a translucent zirconia sintered body which is necessary for the production of a zirconia sintered body having a high sintered-body density and high strength and giving an excellent sense of translucency, without conducting any special sintering, such as HIP sintering. The invention relates to a technique for obtaining, through normal-pressure sintering, a translucent zirconia sintered body characterized by comprising zirconia which contains 2-4 mol % yttria as a stabilizer and has an alumina content of 0.2 wt % or lower, and by having a relative density of 99.8% or higher and a total light transmittance, as measured at a thickness of 1.0 mm, of 35% or higher. It is preferred that a powder containing 0-0.2 wt % alumina with a particle diameter of 0.01-0.5 ?m, having a BET specific surface area of 5-16 m2/g and an average particle diameter of 0.3-0.7 ?m, and having a rate of sintering shrinkage in normal-pressure sintering (??/?T; g/cm3·° C.) of 0.Type: ApplicationFiled: August 29, 2014Publication date: December 18, 2014Applicant: TOSOH CORPORATIONInventors: Hiroyuki Fujisaki, Kiyotaka Kawamura, Kohei Imai
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Publication number: 20140227654Abstract: A zirconia sintered body having not only high strength but also excellent aesthetic properties. A colored translucent zirconia sintered body, characterized by containing an iron compound and from 2 to 4 mol % of yttria, showing a lightness L* of from 51 to 80 in L*a*b* color system, and having a relative density of at least 99.80%. The colored zirconia sintered body preferably has a total light transmittance of at least 20% as measured at a sample thickness of 1 mm and with a D65 light source. The colored translucent zirconia sintered body has aesthetic properties equivalent to those of natural teeth and is particularly suitable for a zirconia sintered body to be used for dental applications, and further, suitable for a mill blank such as an artificial tooth material or the like, and an orthodontic bracket.Type: ApplicationFiled: July 27, 2012Publication date: August 14, 2014Applicant: TOSOH CORPORATIONInventors: Hiroyuki Fujisaki, Kiyotaka Kawamura, Kohei Imai
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Publication number: 20110027742Abstract: A subject of the invention relates to providing a powder for a translucent zirconia sintered body which is necessary for the production of a zirconia sintered body having a high sintered-body density and high strength and giving an excellent sense of translucency, without conducting any special sintering, such as HIP sintering. The invention relates to a technique for obtaining, through normal-pressure sintering, a translucent zirconia sintered body characterized by comprising zirconia which contains 2-4 mol % yttria as a stabilizer and has an alumina content of 0.2 wt % or lower, and by having a relative density of 99.8% or higher and a total light transmittance, as measured at a thickness of 1.0 mm, of 35% or higher. It is preferred that a powder containing 0-0.2 wt % alumina with a particle diameter of 0.01-0.5 ?m, having a BET specific surface area of 5-16 m2/g and an average particle diameter of 0.3-0.7 ?m, and having a rate of sintering shrinkage in normal-pressure sintering (??/?T; g/cm3·° C.) of 0.Type: ApplicationFiled: April 8, 2009Publication date: February 3, 2011Applicant: TOSOH CORPORATIONInventors: Hiroyuki Fujisaki, Kiyotaka Kawamura, Kohei Imai
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Publication number: 20090253884Abstract: Disclosed is a simplified method for producing a polysiloxane in which wastes discharged during the production are reduced. This method for producing a polysiloxane is characterized in that a mixture of a silicon-containing compound represented by the following average composition formula (A): R1a(R2O)bSiO[(4-a-b)/2] (where R1s represent the same or different substituted or unsubstituted monovalent hydrocarbon groups; R2 represents a monovalent hydrocarbon group having 4 or less carbon atoms; and a and b satisfy 0?a?3; 0<b?4; and 0<a+b?4) and water is subjected to a hydrolysis-condensation reaction at a temperature of not less than 200° C. under a pressure of not less than 2.5 MPa.Type: ApplicationFiled: July 19, 2006Publication date: October 8, 2009Inventors: Takuya Ogawa, Kohei Imai, Yoshito Oshima