Patents by Inventor Kiyoshi Yukawa
Kiyoshi Yukawa 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: 8957166Abstract: A method for producing a propylene-based polymer, including polymerizing propylene or propylene and an ?-olefin except propylene in the presence of a catalyst with a horizontal polymerization reactor equipped with stirring vanes rotating around a horizontal axis therein by a continuous vapor-phase polymerization, which removes heat of polymerization by heat of vaporization of a liquefied propylene, wherein the reactor can set a plurality of area sections different in temperature in a horizontal direction inside the reactor, and satisfies at least one of i) a temperature difference, ?T1=T??T?, between an area section including an upstream end of the reactor (T?) and a downstream end (T?) thereof is 0.1 to 20° C. and ii) a temperature difference, ?T2=Tx?Tz, between an area section including a catalyst feed part (Tx) and dew point (Tz) of a mix gas in the reactor is 0 to 5° C.Type: GrantFiled: October 29, 2010Date of Patent: February 17, 2015Assignee: Japan Polypropylene CorporationInventors: Yoshitaka Kobayashi, Takanori Nakashima, Kiyoshi Yukawa, Yusuke Yamada, Hajime Aoyama, Nobuhiro Iwai
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Publication number: 20120302716Abstract: A method for producing a propylene-based polymer, including polymerizing propylene or propylene and an ?-olefin except propylene in the presence of a catalyst with a horizontal polymerization reactor equipped with stirring vanes rotating around a horizontal axis therein by a continuous vapor-phase polymerization, which removes heat of polymerization by heat of vaporization of a liquefied propylene, wherein the reactor can set a plurality of area sections different in temperature in a horizontal direction inside the reactor, and satisfies at least one of i) a temperature difference, ?T1=T??T?, between an area section including an upstream end of the reactor (T?) and a downstream end (T?) thereof is 0.1 to 20° C. and ii) a temperature difference, ?T2=Tx?Tz, between an area section including a catalyst feed part (Tx) and dew point (Tz) of a mix gas in the reactor is 0 to 5° C.Type: ApplicationFiled: October 29, 2010Publication date: November 29, 2012Applicant: JAPAN POLYPROPYLENE CORPORATIONInventors: Yoshitaka Kobayashi, Takanori Nakashima, Kiyoshi Yukawa, Yusuke Yamada, Hajime Aoyama, Nobuhiro Iwai
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Patent number: 7875682Abstract: Disclosed is a propylene block copolymer having excellent flexibility and impact resistance and showing a good polymer powder form. Also disclosed is a process for producing the copolymer. More specifically, the copolymer is a novel propylene block copolymer which satisfies a specific requirement and is produced by a process comprising continuously performing a multi-step polymerization composed of a former step in which a propylene homopolymer component or a specific propylene copolymer component is produced in the presence of a metallocene catalyst carried on a support and a latter step in which propylene and a specific copolymer component are produced by gas phase polymerization.Type: GrantFiled: July 28, 2006Date of Patent: January 25, 2011Assignee: Japan Polypropylene CorporationInventors: Kiyoshi Yukawa, Takehiro Sagae
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Publication number: 20100144990Abstract: Disclosed is a propylene block copolymer having excellent flexibility and impact resistance and showing a good polymer powder form. Also disclosed is a process for producing the copolymer. More specifically, the copolymer is a novel propylene block copolymer which satisfies a specific requirement and is produced by a process comprising continuously performing a multi-step polymerization composed of a former step in which a propylene homopolymer component or a specific propylene copolymer component is produced in the presence of a metallocene catalyst carried on a support and a latter step in which propylene and a specific copolymer component are produced by gas phase polymerization.Type: ApplicationFiled: July 28, 2006Publication date: June 10, 2010Applicant: Japan Polypropylene CorporationInventors: Kiyoshi Yukawa, Takehiro Sagae
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Patent number: 7485686Abstract: A large-scale and efficient industrialization of olefin polymerization by metallocene catalysts is realized by, in olefin polymerization by metallocene-based catalysts, increasing catalytic activity and polymerization efficiency to sufficiently bring out the performances of the metallocene catalysts and maintain a stable polymerization reaction. The amount of a halogen-containing compound is controlled so that the gram-atomic amount ratio to a transition metal of a halogen atom in a halogen-containing compound in solvents and materials other than a halogen atom in a catalyst component is 0.8 or less, in manufacturing plants of commercial level in an olefin polymerization by a metallocene catalyst.Type: GrantFiled: July 29, 2004Date of Patent: February 3, 2009Assignee: Japan Polypropylene CorporationInventors: Kazuhiro Yamamoto, Kiyoshi Yukawa, Yasuhiro Kashiwagi, Yoichi Maeda
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Publication number: 20050032993Abstract: A large-scale and efficient industrialization of olefin polymerization by metallocene catalysts is realized by, in olefin polymerization by metallocene-based catalysts, increasing catalytic activity and polymerization efficiency to sufficiently bring out the performances of the metallocene catalysts and maintain a stable polymerization reaction. The amount of a halogen-containing compound is controlled so that the gram-atomic amount ratio to a transition metal of a halogen atom in a halogen-containing compound in solvents and materials other than a halogen atom in a catalyst component is 0.8 or less, in manufacturing plants of commercial level in an olefin polymerization by a metallocene catalyst.Type: ApplicationFiled: July 29, 2004Publication date: February 10, 2005Applicant: JAPAN POLYPROPYLENE CORPORATIONInventors: Kazuhiro Yamamoto, Kiyoshi Yukawa, Yasuhiro Kashiwagi, Yoichi Maeda
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Patent number: 6756463Abstract: A propylene polymer is characterized by satisfying the following (1) to (5): (1) a melt flow rate (MFR) measured at 230° C. under a 2.16 kg load of from 0.1 to 1000 g/10 min; (2) an isotactic triad traction (mm) measured by 13C-NMR of 99.0 % or above; (3) a Q value measured by gel permeation chromatography (GPC) of from 2.0 to 6.0; (4) a relation between melt flow rate (MFR: g/10 min) measured at 230° C. under a 2.16 kg load and a memory effect (ME) measured at 190° C. at an orifice diameter of 1.0 mm satisfying the following formula (I): 1.75≧(ME)+0.26×log(MFR)≧1.40 (I); and (5) a relation of the cold xylene solubles at 23° C. (CXS) satisfying the following formula (II) CXS≦0.5×[C2]+0.2×log(MFR)+0.5 (II) wherein [C2] represents the ethylene unit content (% by weight) in the polymer.Type: GrantFiled: May 16, 2002Date of Patent: June 29, 2004Assignee: Japan Polychem CorporationInventors: Toshihiko Sugano, Masaaki Ito, Kiyoshi Yukawa
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Publication number: 20030216527Abstract: A propylene polymer is characterized by satisfying the following (1) to (5):Type: ApplicationFiled: May 16, 2002Publication date: November 20, 2003Applicant: Japan PolyChem CorporationInventors: Toshihiko Sugano, Masaaki Ito, Kiyoshi Yukawa
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Patent number: 6466875Abstract: A concentration distribution of a rubber component in block copolymer particles is computed based on the operating conditions of a polymerization apparatus, a growth model equation of polymer particles on a solid catalyst component, and a residence time distribution of the particles in each of a homopolymerization stage and a copolymerization stage, and the gel content of the block copolymer is estimated based on the computation. The gel content of a propylene block copolymer can thereby be estimated precisely.Type: GrantFiled: December 28, 1999Date of Patent: October 15, 2002Assignee: Mitsubishi Chemical CorporationInventors: Kenji Mitsutani, Glen H. Ko, Kiyoshi Yukawa, Fuminao Watanabe
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Patent number: 6191232Abstract: The present invention provides a propylene block copolymer comprising polymer particles whose rubber-like component contents are 50% by weight or more, in an amount less than 1.0% by weight of the whole polymer particles finally discharged from a polymerization system.Type: GrantFiled: October 2, 1998Date of Patent: February 20, 2001Assignee: Mitsubishi Chemical CorporationInventors: Kenji Mitsutani, Kiyoshi Yukawa, Fumihiko Shimizu, Glen H. Ko, Eiji Tanaka, Fuminao Watanabe