Patents by Inventor Hisanao Tosaka
Hisanao Tosaka 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: 7573008Abstract: A PTC element comprising a PTC element body containing a polymer matrix and conductive particles, a pair of electrodes in contact with the PTC element body, and a protective layer composed of a cured epoxy resin composition containing an epoxy resin and a thiol-based curing agent, and covering the PTC element body so as to seal the PTC element body.Type: GrantFiled: December 22, 2006Date of Patent: August 11, 2009Assignee: TDK CorporationInventors: Masaaki Yamashita, Yasuhide Yamashita, Tsuyoshi Sugiyama, Hisanao Tosaka
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Patent number: 7414515Abstract: An object is to provide a PTC element capable of preventing lead terminals from delaminating from an element body. This PTC element 1 is a PTC element comprising an element body 10 in which an electroconductive filler is dispersed in a crystalline polymer, and a pair of terminal electrodes 12, 14 thermocompression-bonded with the element body 10 in between, wherein each of the pair of terminal electrodes 12, 14 has an overlapping region 121, 141 overlapping with the element body 10, and a nonoverlapping region 122, 142 not overlapping with the element body 10, and wherein the nonoverlapping region 122, 142 of each of the pair of terminal electrodes 12, 14 is constructed of a succession of a wide portion 122a a width of which is large across a direction in which the terminal electrode 12, 14 extends from the element body 10, and a narrow portion 122b a width of which is smaller than the width of the wide portion 122a.Type: GrantFiled: August 24, 2006Date of Patent: August 19, 2008Assignee: TDK CorporationInventors: Noriaki Hirano, Kunio Mogi, Tsutomu Hatakeyama, Tsukasa Kon, Tokuhiko Handa, Hisanao Tosaka
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Patent number: 7368069Abstract: In a PTC thermistor comprising at least a pair of electrodes disposed so as to face each other and a thermistor element disposed between the electrodes and having a positive resistance-temperature characteristic, the thermistor element is a molded body constituted by a high molecular matrix, a low molecular organic compound, and conductive particles having electric conductivity, the molecular weight of the high molecular matrix is between 10,000 and 400,000, the molecular weight of the low molecular organic compound is between 100 and 3,000, and the high molecular matrix is an olefin-type high molecular compound having a melting start temperature of between 85 and 95° C.Type: GrantFiled: February 7, 2003Date of Patent: May 6, 2008Assignee: TDK CorporationInventors: Hisanao Tosaka, Yasuhide Yamashita
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Patent number: 7326889Abstract: A method of manufacturing a PTC element comprising a pair of lead terminals bonded together by thermocompression with a matrix held therebetween comprises a matrix preparing step of preparing a matrix constructed by dispersing a conductive filler into a crystalline polymer; a terminal preparing step of preparing a pair of lead terminals holding the matrix therebetween, a surface of each lead terminal facing the matrix being formed with a plurality of anchor protrusions separated from each other; a flattening step of flattening the anchor protrusions formed in respective nonoverlapping areas in the pair of lead terminals kept from overlapping the matrix; and a thermocompression bonding step of holding the matrix between respective overlapping areas in the pair of lead terminals overlapping the matrix, and securing the pair of lead terminals and the matrix together by thermocompression bonding.Type: GrantFiled: September 15, 2006Date of Patent: February 5, 2008Assignee: TDK CorporationInventors: Hisanao Tosaka, Tokuhiko Handa, Hirokazu Satoh, Tsutomu Hatakeyama
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Publication number: 20070151968Abstract: A PTC element comprising a PTC element body containing a polymer matrix and conductive particles, a pair of electrodes in contact with the PTC element body, and a protective layer composed of a cured epoxy resin composition containing an epoxy resin and a thiol-based curing agent, and covering the PTC element body so as to seal the PTC element body.Type: ApplicationFiled: December 22, 2006Publication date: July 5, 2007Applicant: TDK CORPORATIONInventors: Masaaki Yamashita, Yasuhide Yamashita, Tsuyoshi Sugiyama, Hisanao Tosaka
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Publication number: 20070069848Abstract: A method of manufacturing a PTC element comprising a pair of lead terminals bonded together by thermocompression with a matrix held therebetween comprises a matrix preparing step of preparing a matrix constructed by dispersing a conductive filler into a crystalline polymer; a terminal preparing step of preparing a pair of lead terminals holding the matrix therebetween, a surface of each lead terminal facing the matrix being formed with a plurality of anchor protrusions separated from each other; a flattening step of flattening the anchor protrusions formed in respective nonoverlapping areas in the pair of lead terminals kept from overlapping the matrix; and a thermocompression bonding step of holding the matrix between respective overlapping areas in the pair of lead terminals overlapping the matrix, and securing the pair of lead terminals and the matrix together by thermocompression bonding.Type: ApplicationFiled: September 15, 2006Publication date: March 29, 2007Applicant: TDK CORPORATIONInventors: Hisanao Tosaka, Tokuhiko Handa, Hirokazu Satoh, Tsutomu Hatakeyama
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Publication number: 20070046420Abstract: An object is to provide a PTC element capable of preventing lead terminals from delaminating from an element body. This PTC element 1 is a PTC element comprising an element body 10 in which an electroconductive filler is dispersed in a crystalline polymer, and a pair of terminal electrodes 12, 14 thermocompression-bonded with the element body 10 in between, wherein each of the pair of terminal electrodes 12, 14 has an overlapping region 121, 141 overlapping with the element body 10, and a nonoverlapping region 122, 142 not overlapping with the element body 10, and wherein the nonoverlapping region 122, 142 of each of the pair of terminal electrodes 12, 14 is constructed of a succession of a wide portion 122a a width of which is large across a direction in which the terminal electrode 12, 14 extends from the element body 10, and a narrow portion 122b a width of which is smaller than the width of the wide portion 122a.Type: ApplicationFiled: August 24, 2006Publication date: March 1, 2007Applicant: TDK CORPORATIONInventors: Noriaki Hirano, Kunio Mogi, Tsutomu Hatakeyama, Tsukasa Kon, Tokuhiko Handa, Hisanao Tosaka
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Publication number: 20060231807Abstract: In a first aspect of the present invention, a PTC composition contains (a) a crosslinked polymer matrix having a gel fraction of at least 10%, and (b) an electrically conductive substance. An article shaped therefrom yields an electric resistance of at least 50 m? at 25° C. after being placed in an environment repeating 200 times of a temperature change between ?40° C. and +85° C., and exhibits no thermal deformation when placed on a hot plate at 200° C. for 5 minutes.Type: ApplicationFiled: June 20, 2006Publication date: October 19, 2006Applicant: TDK CORPORATIONInventors: Hisanao Tosaka, Yasuhide Yamashita, Tokuhiko Handa, Katsumi Kobayashi
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Patent number: 7019613Abstract: A PTC thermistor 10 comprises, at least, a pair of electrodes 2, 3 and a thermistor body 1, disposed between the electrodes 2, 3, having a positive resistance vs. temperature characteristic. The thermistor body includes, at least, a thermoplastic resin and an electrically conductive particle made of a metal powder. The thermoplastic resin and electrically conductive particle have respective contents and a state of dispersion adjusted so as to yield a magnetization of 4.0×10?5 to 6.0×10?5 Wb·m·kg?1 when a magnetic field of 3.98×105 A·m?1 is applied to the thermistor body.Type: GrantFiled: June 18, 2003Date of Patent: March 28, 2006Assignee: TDK CorporationInventors: Yoshito Nihira, Noriaki Hirano, Hisanao Tosaka
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Publication number: 20050116808Abstract: In a PTC thermistor comprising at least a pair of electrodes 2 and 3 disposed so as to face each other and a thermistor element disposed between the electrodes 2 and 3 and having a positive resistance-temperature characteristic, the thermistor element is a molded body constituted by a high molecular matrix, a low molecular organic compound, and conductive particles having electric conductivity, the molecular weight of the high molecular matrix is between 10,000 and 400,000, the molecular weight of the low molecular organic compound is between 100 and 3,000, and the high molecular matrix is an olefin-type high molecular compound having a melting start temperature of between 85 and 95° C.Type: ApplicationFiled: February 7, 2003Publication date: June 2, 2005Inventors: Hisanao Tosaka, Yasuhide Yamashita
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Publication number: 20040041683Abstract: In a first aspect of the present invention, a PTC composition contains (a) a crosslinked polymer matrix having a gel fraction of at least 10%, and (b) an electrically conductive substance. An article shaped therefrom yields an electric resistance of at least 50 m&OHgr; at 25° C. after being placed in an environment repeating 200 times of a temperature change between −40° C. and +85° C., and exhibits no thermal deformation when placed on a hot plate at 200° C. for 5 minutes.Type: ApplicationFiled: May 27, 2003Publication date: March 4, 2004Applicant: TDK CorporationInventors: Hisanao Tosaka, Yasuhide Yamashita, Tokuhiko Handa, Katsumi Kobayashi
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Publication number: 20030234717Abstract: A PTC thermistor 10 comprises, at least, a pair of electrodes 2, 3 and a thermistor body 1, disposed between the electrodes 2, 3, having a positive resistance vs. temperature characteristic. The thermistor body includes, at least, a thermoplastic resin and an electrically conductive particle made of a metal powder. The thermoplastic resin and electrically conductive particle have respective contents and a state of dispersion adjusted so as to yield a magnetization of 4.0×10−5 to 6.0×10−5 Wb·m·kg−1 when a magnetic field of 3.98×105 A·m−1 is applied to the thermistor body.Type: ApplicationFiled: June 18, 2003Publication date: December 25, 2003Applicant: TDK CORPORATIONInventors: Yoshito Nihira, Noriaki Hirano, Hisanao Tosaka
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Publication number: 20020153992Abstract: A polymer PTC element includes:Type: ApplicationFiled: April 18, 2002Publication date: October 24, 2002Applicant: TDK CORPORATIONInventors: Katsumi Kobayashi, Hisanao Tosaka
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Patent number: 5793276Abstract: An organic PTC thermistor having a positive temperature coefficient of resistivity, which comprises a PTC composition comprising an organic polymer having dispersed therein a conductive substance, and at least one pair of electrodes, wherein the conductive substance is tungsten carbide powder; or the electrodes each comprise a metal mesh and a metal layer.Type: GrantFiled: July 17, 1996Date of Patent: August 11, 1998Assignee: TDK CorporationInventors: Hisanao Tosaka, Minoru Takaya, Shigeru Moriya, Hisashi Kobuke, Munemitsu Hamada