Patents by Inventor Tadakazu Ishiwata
Tadakazu Ishiwata 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: 11961683Abstract: A biaxially stretched polypropylene film which has a thickness of from 1.0 ?m to 3.5 ?m, a tensile fracture stress at 135° C. of 70 MPa or more in a first direction, and a difference between the tensile fracture stress at 125° C. in the first direction and the tensile fracture stress at 135° C. in the first direction of from 0 MPa to 15 MPa (inclusive).Type: GrantFiled: August 28, 2019Date of Patent: April 16, 2024Assignee: Oji Holdings CorporationInventors: Yoshimune Okuyama, Takeshi Tominaga, Yoshikazu Fujishiro, Tadakazu Ishiwata
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Patent number: 11926730Abstract: A polypropylene film which is capable of suppressing blocking in a rolled polypropylene film. The polypropylene film has a first surface and a second surface, contains a polypropylene resin as a main component, and is configured such that: the Svk value (SvkA) of the first surface is 0.005 ?m or more and 0.030 ?m or less; the Spk value (SpkA) of the first surface is more than 0.035 ?m and 0.080 ?m or less; the Svk value (SvkB) of the second surface is 0.005 ?m or more and 0.030 ?m or less; and the Spk value (SpkB) of the second surface is 0.015 ?m or more and 0.035 ?m or less.Type: GrantFiled: April 17, 2023Date of Patent: March 12, 2024Assignee: Oji Holdings CorporationInventors: Tatsuji Ishida, Yoshimune Okuyama, Masahiro Nakata, Tadakazu Ishiwata
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Publication number: 20230416479Abstract: Provided is a polypropylene film having a high dielectric breakdown strength at high temperatures. Provided is a polypropylene film in which a polypropylene resin constituting the polypropylene film has a molecular-weight distribution (Mw/Mn) of the weight-average molecular weight Mw to the number-average molecular weight Mn of has a Z-average molecular weight Mz of 950,000-1,500,000, and has a weight proportion w of 2.6-4.2% in an integral molecular-weight distribution curve when the logarithmic molecular weight Log(M) is 4.0.Type: ApplicationFiled: November 15, 2021Publication date: December 28, 2023Inventors: Tatsuji ISHIDA, Takeshi TOMINAGA, Tadakazu ISHIWATA
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Publication number: 20230340245Abstract: A polypropylene film which is capable of suppressing blocking in a rolled polypropylene film. The polypropylene film has a first surface and a second surface, contains a polypropylene resin as a main component, and is configured such that: the Svk value (SvkA) of the first surface is 0.005 ?m or more and 0.030 ?m or less; the Spk value (SpkA) of the first surface is more than 0.035 ?m and 0.080 ?m or less; the Svk value (SvkB) of the second surface is 0.005 ?m or more and 0.030 ?m or less; and the Spk value (SpkB) of the second surface is 0.015 ?m or more and 0.035 ?m or less.Type: ApplicationFiled: April 17, 2023Publication date: October 26, 2023Inventors: Tatsuji ISHIDA, Yoshimune OKUYAMA, Masahiro NAKATA, Tadakazu ISHIWATA
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Patent number: 11661507Abstract: A polypropylene film which is capable of suppressing blocking in a rolled polypropylene film. The polypropylene film has a first surface and a second surface, contains a polypropylene resin as a main component, and is configured such that: the Svk value (SvkA) of the first surface is 0.005 ?m or more and 0.030 ?m or less; the Spk value (SpkA) of the first surface is more than 0.035 ?m and 0.080 ?m or less; the Svk value (SvkB) of the second surface is 0.005 ?m or more and 0.030 ?m or less; and the Spk value (SpkB) of the second surface is 0.015 ?m or more and 0.035 ?m or less.Type: GrantFiled: September 9, 2022Date of Patent: May 30, 2023Assignee: Oji Holdings CorporationInventors: Tatsuji Ishida, Yoshimune Okuyama, Masahiro Nakata, Tadakazu Ishiwata
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Publication number: 20230044276Abstract: A polypropylene film which is capable of suppressing blocking in a rolled polypropylene film. The polypropylene film has a first surface and a second surface, contains a polypropylene resin as a main component, and is configured such that: the Svk value (SvkA) of the first surface is 0.005 ?m or more and 0.030 ?m or less; the Spk value (SpkA) of the first surface is more than 0.035 ?m and 0.080 ?m or less; the Svk value (SvkB) of the second surface is 0.005 ?m or more and 0.030 ?m or less; and the Spk value (SpkB) of the second surface is 0.015 ?m or more and 0.035 ?m or less.Type: ApplicationFiled: September 9, 2022Publication date: February 9, 2023Inventors: Tatsuji ISHIDA, Yoshimune OKUYAMA, Masahiro NAKATA, Tadakazu ISHIWATA
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Patent number: 11492475Abstract: A polypropylene film which is capable of suppressing blocking in a rolled polypropylene film. The polypropylene film has a first surface and a second surface, contains a polypropylene resin as a main component, and is configured such that: the Svk value (SvkA) of the first surface is 0.005 ?m or more and 0.030 ?m or less; the Spk value (SpkA) of the first surface is more than 0.035 ?m and 0.080 ?m or less; the Svk value (SvkB) of the second surface is 0.005 ?m or more and 0.030 ?m or less; and the Spk value (SpkB) of the second surface is 0.015 ?m or more and 0.035 ?m or less.Type: GrantFiled: December 26, 2018Date of Patent: November 8, 2022Assignee: OJI HOLDINGS CORPORATIONInventors: Tatsuji Ishida, Yoshimune Okuyama, Masahiro Nakata, Tadakazu Ishiwata
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Patent number: 11142618Abstract: A biaxially stretched polypropylene film including a polypropylene resin and satisfying the following: (a) the crystallite size Sa, which is determined using the Scherrer equation from the full width at half maximum of the ?-crystal (040) plane reflection peak as measured by wide-angle x-ray diffraction after treatment for 200 hours at 105° C., is not more than 12.9 nm; and (b) the planar orientation coefficient ?Pa, which is calculated from the birefringence values ?Nyz and ?Nxz with respect to the thickness direction as determined by optical birefringence measurement after treatment for 200 hours at 105° C., is at least 0.013 (?Pa=(?Nyz+?Nxz)/2).Type: GrantFiled: September 22, 2017Date of Patent: October 12, 2021Assignee: Oji Holdings CorporationInventors: Takeshi Tominaga, Michiko Sueyoshi, Yoshimune Okuyama, Masahiro Nakata, Tadakazu Ishiwata
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Publication number: 20210291427Abstract: A biaxially stretched polypropylene film which has a thickness of from 1.0 ?m to 3.5 ?m, a tensile fracture stress at 135° C. of 70 MPa or more in a first direction, and a difference between the tensile fracture stress at 125° C. in the first direction and the tensile fracture stress at 135° C. in the first direction of from 0 MPa to 15 MPa (inclusive).Type: ApplicationFiled: August 28, 2019Publication date: September 23, 2021Inventors: Yoshimune OKUYAMA, Takeshi TOMINAGA, Yoshikazu FUJISHIRO, Tadakazu ISHIWATA
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Patent number: 10910164Abstract: The present invention relates to a biaxially stretched polypropylene film for capacitor. The biaxially stretched polypropylene film for capacitor of the present invention can suppress an increase in tan ? and a decrease in the electrostatic capacitance even when the capacitor is used at a high voltage and an elevated temperature for a long duration.Type: GrantFiled: March 31, 2016Date of Patent: February 2, 2021Assignee: OJI HOLDINGS CORPORATIONInventors: Yoshimune Okuyama, Yoshikazu Fujishiro, Masahiro Nakata, Tadakazu Ishiwata, Akihiro Kakehi
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Publication number: 20200377706Abstract: A polypropylene film which is capable of suppressing blocking in a rolled polypropylene film. The polypropylene film has a first surface and a second surface, contains a polypropylene resin as a main component, and is configured such that: the Svk value (SvkA) of the first surface is 0.005 ?m or more and 0.030 ?m or less; the Spk value (SpkA) of the first surface is more than 0.035 ?m and 0.080 ?m or less; the Svk value (SvkB) of the second surface is 0.005 ?m or more and 0.030 ?m or less; and the Spk value (SpkB) of the second surface is 0.015 ?m or more and 0.035 ?m or less.Type: ApplicationFiled: December 26, 2018Publication date: December 3, 2020Inventors: Tatsuji ISHIDA, Yoshimune OKUYAMA, Masahiro NAKATA, Tadakazu ISHIWATA
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Patent number: 10759929Abstract: A main object is to provide a biaxially stretched polypropylene film for capacitors that has high voltage resistance at high temperatures and excellent dielectric breakdown properties and that can be formed into an ultrathin film. Furthermore, a capacitor obtained by using the biaxially stretched polypropylene film for capacitors described above is provided. The biaxially stretched polypropylene film for capacitors, includes a polypropylene resin, and the film has a spacing value of (040) face of ?-crystal measured by X-ray diffraction of 0.525 to 0.530 nm.Type: GrantFiled: March 31, 2015Date of Patent: September 1, 2020Assignee: OJI HOLDINGS CORPORATIONInventors: Toshiaki Taniike, Minoru Terano, Ikki Katada, Tadakazu Ishiwata, Masahiro Nakata
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Publication number: 20190315047Abstract: A biaxially oriented polypropylene film containing a polypropylene resin, the film having a thickness of 1.0 to 3.0 ?m, and a molecular orientation coefficient ?Nx of 0.013 to 0.016, as calculated according to ?Nx=(?Nxy+?Nxz)/2 on the basis of a birefringence value ?Nxy in the slow axis direction with respect to the fast axis direction and a birefringence value ?Nxz in the slow axis direction with respect to the thickness direction, as measured via optical birefringence measurement.Type: ApplicationFiled: December 28, 2017Publication date: October 17, 2019Inventors: Takeshi TOMINAGA, Michiko SUEYOSHI, Yoshimune OKUYAMA, Yoshikazu FUJISHIRO, Masahiro NAKATA, Tadakazu ISHIWATA
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Patent number: 10431380Abstract: Provided is a biaxially stretched polypropylene film for capacitors having a thin thickness and having excellent initial voltage resistance and excellent long-term heat resistance and voltage resistance, and also provided is a metallized polypropylene film for capacitors. The polypropylene film for capacitors is obtained by biaxially stretching a polypropylene resin, the polypropylene film having a crystallite size of 122 ? or less as determined by the Scherrer's equation from the half width of the reflection peak from (040) plane of ?-crystal measured by a wide angle X-ray diffraction method, and the polypropylene film having a value of birefringence ?Nyz with respect to a thickness direction of 7.0×10?3 or more and 10.0×10?3 or less as measured by an optical birefringence measurement.Type: GrantFiled: September 30, 2014Date of Patent: October 1, 2019Assignee: OJI HOLDINGS CORPORATIONInventors: Masahiro Nakata, Kazuo Ikeda, Tadakazu Ishiwata, Akihiro Kakehi, Yoshinori Matsuo, Yuichi Shishido, Shigeo Murase
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Publication number: 20190284354Abstract: A biaxially stretched polypropylene film including a polypropylene resin and satisfying the following: (a) the crystallite size Sa, which is determined using the Scherrer equation from the full width at half maximum of the ?-crystal (040) plane reflection peak as measured by wide-angle x-ray diffraction after treatment for 200 hours at 105° C., is not more than 12.9 nm; and (b) the planar orientation coefficient ?Pa, which is calculated from the birefringence values ?Nyz and ?Nxz with respect to the thickness direction as determined by optical birefringence measurement after treatment for 200 hours at 105° C., is at least 0.013 (?Pa=(?Nyz+?Nxz)/2).Type: ApplicationFiled: September 20, 2017Publication date: September 19, 2019Inventors: Takeshi TOMINAGA, Michiko SUEYOSHI, Yoshimune OKUYAMA, Masahiro NAKATA, Tadakazu ISHIWATA
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Patent number: 10294356Abstract: The present invention addresses the problem of providing a biaxially stretched polypropylene film for capacitors, which has high voltage resistance and excellent breakdown properties. The present invention also addresses the problem of providing a biaxially stretched polypropylene film for capacitors, which can be used suitably in a high-capacity capacitor to which a high voltage is to be applied under a higher temperature, and which preferably has a small thickness. The present invention relates to a biaxially stretched polypropylene film for capacitors, wherein a polypropylene resin which constitutes the polypropylene film has a number average molecular weight of 40,000 to 100,000 inclusive and a Z average molecular weight of 950,000 to 1,500,000 includes wherein, in a molecular weight distribution curve, the value of the difference obtained by subtracting a differential distribution value at a logarithmic molecular weight Log (M) of 6.Type: GrantFiled: August 31, 2018Date of Patent: May 21, 2019Assignee: OJI HOLDINGS CORPORATIONInventors: Tatsuji Ishida, Masahiro Nakata, Tadakazu Ishiwata, Akihiro Kakehi, Yoshinori Matsuo, Masahiro Yoda
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Publication number: 20180371223Abstract: The present invention addresses the problem of providing a biaxially stretched polypropylene film for capacitors, which has high voltage resistance and excellent breakdown properties. The present invention also addresses the problem of providing a biaxially stretched polypropylene film for capacitors, which can be used suitably in a high-capacity capacitor to which a high voltage is to be applied under a higher temperature, and which preferably has a small thickness. The present invention relates to a biaxially stretched polypropylene film for capacitors, wherein a polypropylene resin which constitutes the polypropylene film has a number average molecular weight of 40,000 to 100,000 inclusive and a Z average molecular weight of 950,000 to 1,500,000 includes wherein, in a molecular weight distribution curve, the value of the difference obtained by subtracting a differential distribution value at a logarithmic molecular weight Log (M) of 6.Type: ApplicationFiled: August 31, 2018Publication date: December 27, 2018Applicant: OJI HOLDINGS CORPORATIONInventors: Tatsuji ISHIDA, Masahiro NAKATA, Tadakazu ISHIWATA, Akihiro KAKEHI, Yoshinori MATSUO, Masahiro YODA
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Patent number: 10093792Abstract: The present invention addresses the problem of providing a biaxially stretched polypropylene film for capacitors, which has high voltage resistance and excellent breakdown properties. The present invention also addresses the problem of providing a biaxially stretched polypropylene film for capacitors, which can be used suitably in a high-capacity capacitor to which a high voltage is to be applied under a higher temperature, and which preferably has a small thickness. The present invention relates to a bi-axially stretched polypropylene film for capacitors, wherein a polypropylene resin which constitutes the polypropylene film has a number average molecular weight of 40,000 to 100,000 inclusive and a Z average molecular weight of 950,000 to 1,500,000 inclusive, wherein, in a molecular weight distribution curve, the value of the difference obtained by subtracting a differential distribution value at a logarithmic molecular weight Log (M) of 6.Type: GrantFiled: February 10, 2015Date of Patent: October 9, 2018Assignee: OJI HOLDINGS CORPORATIONInventors: Tatsuji Ishida, Masahiro Nakata, Tadakazu Ishiwata, Akihiro Kakehi, Yoshinori Matsuo, Masahiro Yoda
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Publication number: 20180208751Abstract: A main object is to provide a biaxially stretched polypropylene film for capacitors that has high voltage resistance at high temperatures and excellent dielectric breakdown properties and that can be formed into an ultrathin film. Furthermore, a capacitor obtained by using the biaxially stretched polypropylene film for capacitors described above is provided. The biaxially stretched polypropylene film for capacitors, includes a polypropylene resin, and the film has a spacing value of (040) face of ?-crystal measured by X-ray diffraction of 0.525 to 0.530 nm.Type: ApplicationFiled: March 31, 2015Publication date: July 26, 2018Applicant: OJI HOLDINGS CORPORATIONInventors: Toshiaki TANIIKE, Minoru TERANO, Ikki KATADA, Tadakazu ISHIWATA, Masahiro NAKATA
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Publication number: 20180118904Abstract: A chief object is to provide a biaxially stretched polypropylene film for capacitors that is excellent in dielectric breakdown resistance at high temperatures and that can be formed into an ultra-thin film. This relates to a biaxially stretched polypropylene film for capacitors that contains a polypropylene resin having ethylene units, wherein the content of the ethylene units is 7.5 mol % or less based on the total amount of propylene units and ethylene units detected from the film.Type: ApplicationFiled: April 14, 2016Publication date: May 3, 2018Applicant: OJI HOLDINGS CORPORATIONInventors: Masahiro YODA, Tatsuji ISHIDA, Tadakazu ISHIWATA, Masahiro NAKATA