Patents by Inventor Tetsuro Tohma
Tetsuro Tohma 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: 8921249Abstract: The production method of the present invention is a method for producing porous aluminum magnesium titanate by forming a mixture containing Al source powder, Mg source powder, Ti source powder and Si source powder as well as a pore-forming agent to obtain a molded body; presintering the obtained molded body; and then sintering the presintered molded body, wherein the content of the pore-forming agent to a total of 100 parts by mass for the Al source powder, Mg source powder, Ti source powder and Si source powder is 5 to 30 parts by mass, the melting point of the Si source powder is 600 to 1300° C., when the elemental composition ratio of Al, Mg, Ti and Si in the mixture is represented by compositional formula (1): Al2(1?x)MgxTi(1+x)O5+aAl2O3+bSiO2 ??(1), x satisfies 0.05?x?0.15, a satisfies 0?a?0.1 and b satisfies 0.05?b?0.15, and the presintered molded body is sintered at 1300 to 1560° C.Type: GrantFiled: March 4, 2011Date of Patent: December 30, 2014Assignee: Sumitomo Chemical Company, LimitedInventors: Tetsuro Tohma, Kentaro Iwasaki
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Publication number: 20140208706Abstract: A honeycomb structure 100 has a plurality of flow paths 110a and 110b which are partitioned by partition walls 120 and are substantially parallel to each other; and one end of the flow path 110a is plugged by a plugging part 130 at one end surface 100a of the honeycomb structure 100, and one end of the flow path 110b is plugged by a plugging part 130 at the other end surface 100b of the honeycomb structure 100, wherein, in an image of the partition walls 120 obtained by X-ray CT measurement, when the number of communicating holes detected when resolution of the image is 1.5 ?m/pixel is defined as X, and the number of communicating holes detected when resolution of the image is 2.5 ?m/pixel is defined as Y, Y/X is 0.58 or more.Type: ApplicationFiled: March 27, 2014Publication date: July 31, 2014Applicant: SUMITOMO CHEMICAL COMPANY, LIMITEDInventors: Yasuharu KOBASHI, Tetsuro TOHMA, Kentaro IWASAKI
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Publication number: 20140202125Abstract: A method of manufacturing a honeycomb structure comprises a step of forming a molded article by molding a raw material containing a ceramic powder and a pore-forming agent; and a step of manufacturing a honeycomb structure by sintering the molded article, wherein the pore-forming agent is powder formed of a material that disappears at a sintering temperature or less where the molded article is sintered, the powder is obtained by mixing a small particle size powder and a large particle size powder, a median particle size of which a ratio of a cumulative mass with respect to a total mass of the small particle size powder is 50% is 5 to 20 ?m, a median particle size of which a ratio of a cumulative mass with respect to a total mass of the large particle size powder is 50% is 30 ?m or more, and a ninety-percentage particle size of which a ratio of a cumulative mass with respect to a total mass of the large particle size powder is 90% is 80 ?m or less.Type: ApplicationFiled: March 27, 2014Publication date: July 24, 2014Applicant: SUMITOMO CHEMICAL COMPANY, LIMITEDInventors: Yasuharu KOBASHI, Tetsuro TOHMA, Kentaro IWASAKI
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Publication number: 20140065350Abstract: A honeycomb structure 100 has a plurality of flow paths 110a and 110b which are partitioned by partition walls 120 and are substantially parallel to each other; and one end of the flow path 110a is plugged by a plugging part 130 at one end surface 100a of the honeycomb structure 100, and one end of the flow path 110b is plugged by a plugging part 130 at the other end surface 100b of the honeycomb structure 100, wherein, in an image of the partition walls 120 obtained by X-ray CT measurement, when the number of communicating holes detected when resolution of the image is 1.5 ?m/pixel is defined as X, and the number of communicating holes detected when resolution of the image is 2.5 ?am/pixel is defined as Y, Y/X is 0.58 or more.Type: ApplicationFiled: March 9, 2012Publication date: March 6, 2014Applicant: SUMITOMO CHEMICAL COMPANY, LIMITEDInventors: Yasuharu Kobashi, Tetsuro Tohma, Kentaro Iwasaki
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Publication number: 20130062275Abstract: A method of manufacturing a honeycomb structure comprises a step of forming a molded article by molding a raw material containing a ceramic powder and a pore-forming agent; and a step of manufacturing a honeycomb structure by sintering the molded article, wherein the pore-forming agent is powder formed of a material that disappears at a sintering temperature or less where the molded article is sintered, the powder is obtained by mixing a small particle size powder and a large particle size powder, a median particle size of which a ratio of a cumulative mass with respect to a total mass of the small particle size powder is 50% is 5 to 20 ?m, a median particle size of which a ratio of a cumulative mass with respect to a total mass of the large particle size powder is 50% is 30 ?m or more, and a ninety-percentage particle size of which a ratio of a cumulative mass with respect to a total mass of the large particle size powder is 90% is 80 ?m or less.Type: ApplicationFiled: March 16, 2011Publication date: March 14, 2013Applicant: SUMITOMO CHEMICAL COMPANY, LIMITEDInventors: Yasuharu Kobashi, Tetsuro Tohma, Kentaro Iwasaki
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Publication number: 20130048905Abstract: The production method of the present invention is a method for producing porous aluminum magnesium titanate by forming a mixture containing Al source powder, Mg source powder, Ti source powder and Si source powder as well as a pore-forming agent to obtain a molded body; presintering the obtained molded body; and then sintering the presintered molded body, wherein the content of the pore-forming agent to a total of 100 parts by mass for the Al source powder, Mg source powder, Ti source powder and Si source powder is 5 to 30 parts by mass, the melting point of the Si source powder is 600 to 1300° C., when the elemental composition ratio of Al, Mg, Ti and Si in the mixture is represented by compositional formula (1): Al2(1?x)MgxTi(1+x)O5+aAl2O3+bSiO2 ??(1), x satisfies 0.05?x?0.15, a satisfies 0?a?0.1 and b satisfies 0.05?b?0.15, and the presintered molded body is sintered at 1300 to 1560° C.Type: ApplicationFiled: March 4, 2011Publication date: February 28, 2013Inventors: Tetsuro Tohma, Kentaro Iwasaki
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Patent number: 8383534Abstract: The invention is to provide a process capable of producing aluminium magnesium titanate having a small coefficient of thermal expansion at a firing temperature lower than 1500° C. The production process of the invention comprises maintaining a pre-mixture containing a titania source powder, an alumina source powder, a magnesia source powder and a silica source powder within a temperature range of from 1100° C. to 1350° C. for at least 3 hours, followed by heating up to a temperature not lower than 1400° C. and firing at the temperature. The silica source powder is preferably a powder of alkali feldspar. Aluminium magnesium titanate is prepared according to the production process of the invention, and the resulting aluminium magnesium titanate is ground to give an aluminium magnesium titanate powder.Type: GrantFiled: January 19, 2009Date of Patent: February 26, 2013Assignees: Sumitomo Chemical Company, Limited, E.I. du Pont de Nemours and CompanyInventors: Tetsuro Tohma, Keiichiro Suzuki, Satoko Iwato, Rina Yamanaka
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Publication number: 20120311985Abstract: The present invention is a process for producing an aluminum titanate-based ceramics comprising a step of firing a starting material mixture containing a titanium source powder, an aluminum source powder, and a copper source.Type: ApplicationFiled: December 24, 2010Publication date: December 13, 2012Applicant: SUMITOMO CHEMICAL COMPANY, LIMITEDInventors: Kentaro Iwasaki, Tetsuro Tohma
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Publication number: 20120275986Abstract: The present invention is a glass frit comprising 60 to 80% by weight of SiO2, 9 to 20% by weight of Al2O3, 3 to 12% by weight of K2O, and 3 to 12% by weight of Na2O, expressed on oxide basis.Type: ApplicationFiled: September 28, 2010Publication date: November 1, 2012Applicant: SUMITOMO CHEMICAL COMPANY, LIMITEDInventors: Kentaro Iwasaki, Akiyoshi Nemoto, Tetsuro Tohma
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Publication number: 20120198805Abstract: The present invention is a process for producing an aluminum titanate ceramics, comprising firing a starting material mixture containing a titanium source powder and an aluminum source powder, wherein a content of niobium, expressed on the oxide basis, is not less than 0.2 parts by mass and not more than 2.5 parts by mass in 100 parts by mass of the starting material mixture.Type: ApplicationFiled: August 10, 2010Publication date: August 9, 2012Applicant: SUMITOMO CHEMICAL COMPANY ,LIMITEDInventors: Kentaro Iwasaki, Tetsuro Tohma, Kousuke Uoe
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Patent number: 8217256Abstract: The present invention provides a thermoelectric material useful for a thermoelectric converter having excellent energy conversion efficiency, and a method for producing the thermoelectric material. The thermoelectric material comprising an oxide containing Ti, M, and O and the oxide is represented by Formula (1). Ti1-xMxOy??(1) M represents at least one selected from the group consisting of V, Nb, and Ta, x is not less than 0.05 and not more than 0.5, and y is not less than 1.90 and not more than 2.02.Type: GrantFiled: August 13, 2007Date of Patent: July 10, 2012Assignee: Sumitomo Chemical Company, LimitedInventors: Yoshio Uchida, Tetsuro Tohma, Kazuo Sadaoka
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Publication number: 20120034446Abstract: The invention is to provide a process for producing an aluminum titanate-based ceramics capable of realizing low thermal expansion and high mechanical strength and having little dimensional change in firing, at a low firing temperature of lower than 1500° C. The invention is a process for producing an aluminum titanate-based ceramics fired body comprising a step of shaping a ceramic plastic rammed earth containing a precursor mixture and an organic-based binder into a predetermined shape, wherein the starting material mixture containing a titanium source powder, an aluminum source powder and a silicon source powder, and a step of maintaining the shaped ceramics plastic rammed earth within a temperature range of from 900 to 1350° C. at a temperature change per hour of from ?50 to +50° C./hr for 3 hours or more, followed by heating up to a temperature of 1400° C. or higher and firing at the temperature.Type: ApplicationFiled: February 24, 2010Publication date: February 9, 2012Applicant: SUMITOMO CHEMICAL COMPANY, LIMITEDInventors: Tetsuro Tohma, Kousuke Uoe, Hajime Yoshino
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Patent number: 7959833Abstract: A thermoelectric conversion material contains a metal oxide comprising M1, M2 and oxygen, wherein M1 is at least one selected from the group consisting of Ca, Sr and Ba and may contain an element selected from the group consisting of Li, Na, K, Mg, La, Ce, Nd, Sm, Bi and Pb, and wherein M2 comprises Cu as an essential element and may contain an element selected from the group consisting of Ti, V, Cr, Mn, Fe, Co and Ni. The mole ratio of M2 to M1 (M2/M1) is 1.2 to 2.2.Type: GrantFiled: April 11, 2006Date of Patent: June 14, 2011Assignee: Sumitomo Chemical Co., Ltd.Inventors: Tetsuro Tohma, Kazuo Sadaoka, Yoshio Uchida
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Publication number: 20110097582Abstract: An object of the invention is to provide a ceramic having a small thermal expansion coefficient and having more excellent mechanical strength. The invention is an aluminum magnesium titanate-alumina composite ceramic containing aluminum magnesium titanate and alumina and, the elemental composition ratio of Al, Mg and Ti therein is represented by a compositional formula (1): Al2(1?x)MgxTi(1+x)O5+aAl2O3 ??(1), wherein coefficient x satisfies 0<x?1, and coefficient a satisfies 0.4x?a<2x.Type: ApplicationFiled: January 20, 2009Publication date: April 28, 2011Applicant: Sumitomo Chemical Company, LimitedInventors: Tetsuro Tohma, Satoko Iwato, Rina Hatemata
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Publication number: 20110077143Abstract: The invention is to provide a process capable of producing aluminium magnesium titanate having a small coefficient of thermal expansion at a firing temperature lower than 1500° C. The production process of the invention comprises maintaining a pre-mixture containing a titania source powder, an alumina source powder, a magnesia source powder and a silica source powder within a temperature range of from 1100° C. to 1350° C. for at least 3 hours, followed by heating up to a temperature not lower than 1400° C. and firing at the temperature. The silica source powder is preferably a powder of alkali feldspar. Aluminium magnesium titanate is prepared according to the production process of the invention, and the resulting aluminium magnesium titanate is ground to give an aluminium magnesium titanate powder.Type: ApplicationFiled: January 19, 2009Publication date: March 31, 2011Applicant: SUMITOMO CHEMICAL COMPANY, LIMITEDInventors: Tetsuro Tohma, Keiichiro Suzuki, Satoko Iwato, Rina Yamanaka
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Publication number: 20100317508Abstract: The invention is to provide a process for producing an aluminium titanate ceramic by firing a pre-mixture of a titania source powder, an alumina source powder and a magnesia source powder, for a short period of time. The production process of the invention comprises mixing a titania source powder and an alumina source powder followed by dry process grinding in the presence of grinding media under a grinding condition of an acceleration of at least 2G to give a pre-mixture, and firing the resulting pre-mixture. The titania source powder and the alumina source powder may be mixed together with a magnesia source powder and a silica source powder. Preferably, a vibration mill is used for the grinding. Grinding the aluminium titanate ceramic produced according to the production process of the invention gives an aluminium titanate ceramic powder.Type: ApplicationFiled: December 25, 2008Publication date: December 16, 2010Inventors: Hajime Maki, Tetsuro Tohma, Keiichiro Suzuki
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Publication number: 20100298114Abstract: The invention is for obtaining aluminium titanate-based ceramics having a small BET specific surface area and having, when ground into powder, a small pore volume, by effective utilization of particulate aluminium titanate-based ceramics. A pre-mixture prepared by mixing a particulate aluminium titanate-based ceramics with a titania source and an alumina source and optionally further with a magnesia source and a silica source, or particulates of aluminium titanate-based ceramics is, as such or preferably after shaped, fired as the powder or as the molded body to produce an aluminium titanate-based ceramics.Type: ApplicationFiled: January 6, 2009Publication date: November 25, 2010Applicant: SUMITOMO CHEMICAL COMPANY, LIMITEDInventors: Hajime Maki, Tetsuro Tohma, Masayuki Narumi
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Publication number: 20100175735Abstract: The present invention provides a thermoelectric material useful for a thermoelectric converter having excellent energy conversion efficiency, and a method for producing the thermoelectric material. The thermoelectric material comprising an oxide containing Ti, M, and O and the oxide is represented by Formula (1). Ti1-xMxOy??(1) M represents at least one selected from the group consisting of V, Nb, and Ta, x is not less than 0.05 and not more than 0.5, and y is not less than 1.90 and not more than 2.02.Type: ApplicationFiled: August 13, 2007Publication date: July 15, 2010Applicant: Sumitomo Chemical Company, LimitedInventors: Yoshio Uchida, Tetsuro Tohma, Kazuo Sadaoka
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Publication number: 20100140568Abstract: A thermoelectric conversion material, a method for producing the same, and a thermoelectric conversion device are provided. The thermoelectric conversion material includes an oxide represented by formula (1): M1Oy (1), where M1 is at least one selected from the group consisting of V, Nb and Ta, and 1.90?y?2.10 or an oxide represented by formula (2): M11?xM2xOy (2), where M1 and y are as in formula (1), M2 is selected from the group consisting of Ti, Cr, Mn, Fe, Co, Zr, Hf, Mo and W, and 0?x?0.5.Type: ApplicationFiled: April 10, 2009Publication date: June 10, 2010Applicant: SUMITOMO CHEMICAL COMPANY, LIMITEDInventors: Tetsuro Tohma, Kazuo Sadaoka, Yoshio Uchida
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Publication number: 20100140567Abstract: A thermoelectric conversion material contains a metal oxide comprising M1, M2 and oxygen, wherein M1 is at least one selected from the group consisting of Ca, Sr and Ba and may contain an element selected from the group consisting of Li, Na, K, Mg, La, Ce, Nd, Sm, Bi and Pb, and wherein M2 comprises Cu as an essential element and may contain an element selected from the group consisting of Ti, V, Cr, Mn, Fe, Co and Ni. The mole ratio of M2 to M (M2/M1) is 1.2 to 2.2.Type: ApplicationFiled: April 11, 2006Publication date: June 10, 2010Applicant: SUMITOMO CHEMICAL COMPANY ,LIMITEDInventors: Tetsuro Tohma, Kazuo Sadaoka, Yoshio Uchida