Patents by Inventor Jun Birukawa

Jun Birukawa 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).

  • Publication number: 20230088053
    Abstract: An object of the present invention is to provide a film for a capacitor such that the film excels in high-temperature dielectric breakdown voltage (high-temperature BDV) and has blocking resistance, and bleeding-out of, for instance, a nucleating agent is suppressed even after long-term storage. The present invention pertains to a multilayer polypropylene film for a capacitor, the film including a base layer composed of a propylene polymer composition containing a propylene homopolymer (X) and 0.0001 to 0.05 mass % of a polymer-based ?-crystal nucleating agent (C), and a front layer or a back layer composed of a propylene-based polymer (Y) on at least one surface of the base layer, wherein the base layer and the front layer or back layer are stretched.
    Type: Application
    Filed: February 3, 2021
    Publication date: March 23, 2023
    Applicant: PRIME POLYMER CO., LTD.
    Inventors: Jun BIRUKAWA, Satoshi TAMURA, Hiroki SHIMIZU
  • Patent number: 10256041
    Abstract: A polypropylene (F) for film condensers having the following requirements: (1) an MFR (JIS K 7210, 230° C., 2.16 kg load) in the range of 1-10 (g/10 min), (2) an mmmm fraction that is at least 93%, (3) a <2,1>erythro position defect amount as measured using 13C-NMR that is less than 0.1 mol %, (4) ash content obtained by complete combustion in atmosphere that is at most 50 ppm, (5) chlorine content as measured by ion chromatography that is at most 5 ppm; and (6) is obtained by including a propylene homopolymer for which Mw/Mn as measured via GPC is 6.5-12 and an ?-crystal nucleating agent with a melting point of at most 290° C.
    Type: Grant
    Filed: March 30, 2016
    Date of Patent: April 9, 2019
    Assignee: PRIME POLYMER CO., LTD.
    Inventors: Satoshi Tamura, Jun Birukawa, Hiroki Shimizu
  • Publication number: 20180286588
    Abstract: A polypropylene (F) for film condensers having the following requirements: (1) an MFR (JIS K 7210, 230° C., 2.16 kg load) in the range of 1-10 (g/10 min), (2) an mmmm fraction that is at least 93%, (3) a <2,1>erythro position defect amount as measured using 13C-NMR that is less than 0.1 mol %, (4) ash content obtained by complete combustion in atmosphere that is at most 50 ppm, (5) chlorine content as measured by ion chromatography that is at most 5 ppm; and (6) is obtained by including a propylene homopolymer for which Mw/Mn as measured via GPC is 6.5-12 and an ?-crystal nucleating agent with a melting point of at most 290° C.
    Type: Application
    Filed: March 30, 2016
    Publication date: October 4, 2018
    Applicant: PRIME POLYMER CO., LTD.
    Inventors: Satoshi TAMURA, Jun BIRUKAWA, Hiroki SHIMIZU
  • Patent number: 8257822
    Abstract: Provided is a film for thermal sterilization packaging which is excellent in a total balance of characteristics such a transparency, an impact resistance, a heat sealing property, a blocking resistance, a heat resistance and the like. The film for thermal sterilization packaging according to the present invention is characterized by comprising: an outer layer containing a propylene/ethylene block copolymer (A) which has a melt flow rate (MFR; ASTM D1238, 230° C., load: 2.16 kg) in the range of 1 to 10 g/10 minutes and a melting point in the range of 150 to 170° C. measured by means of a differential scanning colorimeter.
    Type: Grant
    Filed: February 6, 2009
    Date of Patent: September 4, 2012
    Assignees: Mitsui Chemicals, Inc., Prime Polymer Co., Ltd.
    Inventors: Mitsuo Kawata, Jun Birukawa, Kunihiko Takesue, Keita Itakura, Tokutaro Kimura