Patents by Inventor Nobutaka Uchikawa

Nobutaka Uchikawa 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).

  • Patent number: 6255425
    Abstract: A syndiotactic polypropylene copolymer is disclosed which comprises 70 to 99.9 mole % of propylene and 0.1 to 30 mole % of an olefin other than propylene; in the 13C-NMR spectrum of the syndiotactic polypropylene copolymer, a ratio of the intensity of a peak at about 20.2 ppm to the sum of the intensities of the total peaks attributable to methyl groups in propylene units at about 19-22 ppm being 0.3 or more. Also disclosed are extrusion-molded high-transparency articles, especially films and sheets and blown films, obtained by the extrusion of a polypropylene substantially having a syndiotactic structure.
    Type: Grant
    Filed: January 18, 1994
    Date of Patent: July 3, 2001
    Assignee: Mitsui Chemicals, Inc.
    Inventors: Tadashi Asanuma, Tetsunosuke Shiomura, Nobutaka Uchikawa, Tateyo Sasaki, Osamu Uchida, Tutomu Iwatani, Shigeru Kimura, Takeo Inoue
  • Patent number: 5656371
    Abstract: An insulating composition comprising a syndiotactic polypropylene (s-PP) having a syndiotactic pentad ratio of not less than 0.7 and an MFR of 0.05-2.0 g/10 min. The composition of the present invention comprising a specific s-PP can provide an article having superior electric properties and mechanical properties. In particular, the article can retain superior electric properties and mechanical properties even after rapid cooling or gradual cooling for re-processing of said article. Accordingly, the composition of the present invention can be suitable used for insulating layer, coating layer of various power cables inclusive of high voltage wires and low voltage wires, coating layer of optical fibers and insulator of wire-connecting structures.
    Type: Grant
    Filed: June 27, 1995
    Date of Patent: August 12, 1997
    Assignees: Mitsubishi Cable Industries, Ltd., Mitsui Toatsu Chemicals, Inc.
    Inventors: Masaki Kawahigashi, Hiroshi Kato, Ryuichi Sugimoto, Nobutaka Uchikawa, Katsumi Yoshino
  • Patent number: 5624621
    Abstract: A fiber excellent in strength and having an average size of 10,000-0.1 denier can be obtained by extruding a new material composed mainly of a polypropylene having a syndiotactic pentad fraction of 0.7 or more and optionally stretching the resulting extruded material. By using as the raw material a composition consisting of two kinds of polypropylenes each having an intrinsic viscosity .eta..sub.1 or .eta..sub.2, the log(.eta..sub.2 /.eta..sub.1) being more than 0.05 or less than -0.05, and a syndiotactic pentad traction of 0.7 or more at a weight ratio of 95:5-5:95 or a composition consisting of at least 50 parts by weight of a syndiotactic polypropylene having the intrinsic viscosity .eta..sub.1 and a syndiotactic pentad fraction of 0.7 or above and at most 50 parts by weight of an isotactic polypropylene having the intrinsic viscosity .eta..sub.2, the extrudability is improved and the fiber stretching conditions are broadened.
    Type: Grant
    Filed: August 24, 1995
    Date of Patent: April 29, 1997
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Tadashi Asanuma, Tetsunosuke Shiomura, Shigeru Kimura, Nobutaka Uchikawa, Yoichi Kawai, Keigo Suehiro, Satoshi Fukushima
  • Patent number: 5548007
    Abstract: A radiation-resistant polypropylene resin composition is disclosed which comprises a polypropylene having a substantially syndiotactic structure, and if desired, a phosphorus-containing anti-oxidant, an amine-containing anti-oxidant and/or a nucleating agent. Molded articles obtained from this resin composition can be utilized as containers for foods and medicines, and their physical properties scarcely deteriorate during sterilization by radiation.
    Type: Grant
    Filed: March 7, 1995
    Date of Patent: August 20, 1996
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Tadashi Asanuma, Shigeru Kimura, Nobutaka Uchikawa, Tetsunosuke Shiomura
  • Patent number: 5548008
    Abstract: A radiation-resistant polypropylene resin composition is disclosed which comprises a polypropylene having a substantially syndiotactic structure, and if desired, a phosphorus-containing anti-oxidant, an amine-containing anti-oxidant and/or a nucleating agent. Molded articles obtained from this resin composition can be utilized as containers for foods and medicines, and their physical properties scarcely deteriorate during sterilization by radiation.
    Type: Grant
    Filed: March 24, 1995
    Date of Patent: August 20, 1996
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Tadashi Asanuma, Shigeru Kimura, Nobutaka Uchikawa, Tetsunosuke Shiomura
  • Patent number: 5478646
    Abstract: A fiber excellent in strength and having an average size of 10,000-0.1 denier can be obtained by extruding a raw material composed mainly of a polypropylene having a syndiotactic pentad fraction of 0.7 or more and optionally stretching the resulting extruded material.By using as the raw material a composition consisting of two kinds of polypropylenes each having an intrinsic viscosity .eta..sub.1 or .eta..sub.2, the log(.eta..sub.2 /.eta..sub.1) being more than 0.05 or less than -0.05, and a syndiotactic pentad fraction of 0.7 or more at a weight ratio of 95:5-5:95 or a composition consisting of at least 50 parts by weight of a syndiotactic polypropylene having the intrinsic viscosity .eta..sub.1 and a syndiotactic pentad fraction of 0.7 or above and at most 50 parts by weight of an isotactic polypropylene having the intrinsic viscosity .eta..sub.2, the extrudability is improved and the fiber stretching conditions are broadened.
    Type: Grant
    Filed: February 8, 1993
    Date of Patent: December 26, 1995
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Tadashi Asanuma, Tetsunosuke Shiomura, Shigeru Kimura, Nobutaka Uchikawa, Yoichi Kawai, Keigo Suehiro, Satoshi Fukushima
  • Patent number: 5428127
    Abstract: Disclosed herein is a process for preparing a syndiotactic polypropylene comprising washing with a hydrocarbon solvent a polymer obtained by polymerizing propylene in the presence of a catalyst comprising a transition metal compound having an asymmetric ligand. The slurry of the polymer obtained by the polymerization is treated with a .beta.-dicarboxy compound and an alcohol or with an alcohol containing hydrochloric acid gasunder non-aqueous conditions prior to the washing with a hydrocarbon solvent so that the residue of the catalyst used in the polymerization reaction may be rendered soluble in the hydrocarbon solvent, the properties of the resulting syndiotactic polypropylene are improved greatly.
    Type: Grant
    Filed: November 10, 1994
    Date of Patent: June 27, 1995
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Tadashi Asanuma, Tetsunosuke Shiomura, Nobutaka Uchikawa, Tateyo Sasaki, Norihide Inoue, Osamu Uchida, Tutomu Iwatani
  • Patent number: 5340848
    Abstract: A radiation-resistant polypropylene resin composition is disclosed which comprises a polypropylene having a substantially syndiotactic structure, and if desired, a phosphorus-containing anti-oxidant, an amine-containing anti-oxidant and/or a nucleating agent. Molded articles obtained from this resin composition can be utilized as containers for foods and medicines, and their physical properties scarcely deteriorate during sterilization by radiation.
    Type: Grant
    Filed: June 9, 1993
    Date of Patent: August 23, 1994
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Tadashi Asanuma, Shigeru Kimura, Nobutaka Uchikawa, Tetsunosuke Shiomura
  • Patent number: 5314956
    Abstract: Disclosed herein is a polypropylene resin composition of a high syndiotacticity comprising a substantial homopolymer of propylene, in which the ratio of the intensity of the peak attributable to the syndiotactic pentad bonds to the sum of the intensities of all the peaks attributable to the methyl groups in the spectrum of the methyl groups measured by .sup.13 C-NMR is 0.7 or more, and a copolymer of ethylene and propylene, and a preparation process thereof.
    Type: Grant
    Filed: January 29, 1993
    Date of Patent: May 24, 1994
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Tadashi Asanuma, Tetsunosuke Shiomura, Nobutaka Uchikawa, Tutomu Iwatani, Katsumi Takeuchi
  • Patent number: 5278216
    Abstract: A syndiotactic polypropylene resin composition comprising a polypropylene having a substantially syndiotactic structure and a nucleating agent. The syndiotactic polypropylene may be a homopolymer of the propylene, a copolymer of the propylene and a smaller amount of another olefin or a mixture of the above-mentioned (co)polymer and an isotactic polypropylene. The resin composition preferably has a higher crystallization temperature than a polypropylene containing no nucleating agent by 5.degree. C. or more, as measurement is made by a differential scanning thermal analysis.
    Type: Grant
    Filed: June 17, 1992
    Date of Patent: January 11, 1994
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Tadashi Asanuma, Tetsunosuke Shiomura, Nobutaka Uchikawa, Tateyo Sasaki, Takeo Inoue
  • Patent number: 5266641
    Abstract: Copolymers of butene-1 and propylene, having specific physical properties and substantially a syndiotactic structure; and easily heat-sealable polypropylene resin compositions comprising 5-50 parts by weight of one of the copolymers and 95-50 parts by weight of a stereoregular crystalline propylene-ethylene copolymer or propylene ethylene-C.sub.4-12 -.alpha.-olefin copolymer having specific compositions and melt flow index.
    Type: Grant
    Filed: January 29, 1993
    Date of Patent: November 30, 1993
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Tadashi Asanuma, Tetsunosuke Shiomura, Tateyo Sasaki, Tutomu Iwatani, Nobutaka Uchikawa, Kouji Kitabayashi
  • Patent number: 5232992
    Abstract: According to the present invention, molded articles can be provided in which a melting point attributed to a syndiotactic polypropylene and measured at a temperature rise rate of 10.degree. C./minute by differential scanning thermal analysis is indicated by a substantially single peak, the aforesaid molded articles being obtained by heating, melting and molding a substantially syndiotactic homopolymer of propylene, a substantially syndiotactic copolymer of propylene and a small amount of another olefin, or a mixture of these polymers and a small amount of a substantially isotactic polypropylene, and then subjecting the molded products to a heat treatment. Furthermore, a method for preparing the above-mentioned molded articles is also provided. The molded articles have high stiffness and impact resistance.
    Type: Grant
    Filed: October 5, 1990
    Date of Patent: August 3, 1993
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Tadashi Asanuma, Tetsunosuke Shiomura, Nobutaka Uchikawa, Tateyo Sasaki, Takeo Inoue
  • Patent number: 5212247
    Abstract: Disclosed herein is a polypropylene resin composition of a high syndiotacticity comprising a substantial homopolymer of propylene, in which the ratio of the intensity of the peak attributable to the syndiotactic pentad bonds to the sum of the intensities of all the peaks attributable to the methyl groups in the spectrum of the methyl groups measured by .sup.13 C-NMR is 0.7 or more, and a copolymer of ethylene and propylene, and a preparation process thereof.
    Type: Grant
    Filed: June 6, 1990
    Date of Patent: May 18, 1993
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Tadashi Asanuma, Tetsunosuke Shiomura, Nobutaka Uchikawa, Tutomu Iwatani, Katsumi Takeuchi
  • Patent number: 5206324
    Abstract: Copolymers of butene-1 and propylene, having specific physical properties and substantially a syndiotactic structure; and easily heat-sealable polypropylene resin compositions comprising 5-50 parts by weight of one of the copolymers and 95-50 parts by weight of a stereoregular crystalline propylene-ethylene copolymer or propylene-ethylene-C.sub.4-12 -.alpha.-olefin copolymer having specific compositions and melt flow index.
    Type: Grant
    Filed: October 3, 1990
    Date of Patent: April 27, 1993
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Tadashi Asanuma, Tetsunosuke Shiomura, Tateyo Sasaki, Tutomu Iwatani, Nobutaka Uchikawa, Kouji Kitabayashi
  • Patent number: 5187250
    Abstract: A poly-.alpha.-olefin of novel structure which is an addition polymer of an .alpha.-olefin having 4 carbon atoms or more, wherein (a) by the analysis of the peaks attributable to the side chain methylene groups directly bonded to the main chain in the .sup.13 C-NMR spectrum produced by the measurement in 1,2,4-trichloro-benzene, (i) a novel main peak not attributable to the isotactic structure thereof is positioned on the side of higher magnetic field than is the peak attributable to the isotactic structure, and (ii) the intensity of said main peak is 0.3 or more relative to the sum of the intensities of the total peaks attributable to the side chain methylene groups directly bonded to the main chain, and (b) the molecular weight measured by gel permeation chromatography and calculated as polypropylene is not less than 1,000.
    Type: Grant
    Filed: December 23, 1991
    Date of Patent: February 16, 1993
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Tadashi Asanuma, Tetsunosuke Shiomura, Yukari Nishimori, Nobutaka Uchikawa
  • Patent number: 5175208
    Abstract: An improved method for preparing block copolymers of propylene which comprises providing a polymerizer composed of at least two reaction vessels connected to one another, substantially homopolymerizing propylene in a first step and then copolymerizing ethylene and propylene in a second step in the presence of a stereoregular catalyst, characterized by carrying out the homopolymerization of propylene in the polymerizer composed of at least two reaction vessels connected to one another in series, then introducing the resulting polymer slurry into a countercurrent washing column and countercurrently washing the slurry with propylene, introducing the washed slurry withdrawn from the lower part of the washing column into a reaction vessel in the second step connected to the washing column and performing the polymerization of ethylene and propylene, of which ratio ranges from 15/85 to 95/5. According to this method, a block copolymer of propylene exhibiting excellent physical properties can be obtained efficiently.
    Type: Grant
    Filed: July 10, 1989
    Date of Patent: December 29, 1992
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Tadashi Asanuma, Mitsuru Ito, Tutomu Iwatani, Kaoru Kawanishi, Nobutaka Uchikawa, Shigeru Kimura, Ryuichi Sugimoto
  • Patent number: 5169924
    Abstract: A copolymer of propylene and butene-1, the constituent monomer units of which comprise 20-63 wt. % of propylene and 37-80 wt. % of butene-1, and which exhibits 0.5 or more in the ratio of the sum of the intensities of absorptions observed at about 20.0-21.0 ppm to the sum of the intensities of total absorptions attributable to the methyl groups in the propylene units observed at about 19.0-22.0 ppm in the .sup.13 C-NMR spectrum measured in a 1,2,4-trichlorobenzene solution and 0.05 or more in the intrinsic viscosity measured at 135.degree. C. in a tetralin solution.
    Type: Grant
    Filed: July 25, 1990
    Date of Patent: December 8, 1992
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Tadashi Asanuma, Tetsunosuke Shiomura, Tateyo Sasaki, Tutomu Iwatani, Nobutaka Uchikawa
  • Patent number: 5157092
    Abstract: A polymer of 4-methylpentene-1 having a substantially syndiotactic structure, which polymer contains 0 to 30 mol % of the .alpha.-olefin unit other than the 4-methylpentene-1 unit and has excellent physical properties.
    Type: Grant
    Filed: June 11, 1990
    Date of Patent: October 20, 1992
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Tadashi Asanuma, Tetsunosuke Shiomura, Nobutaka Uchikawa, Yukari Tamai, Tateyo Sasaki, Tutomu Iwatani
  • Patent number: 5098967
    Abstract: Disclosed herein is a method for controlling the molecular weight of a propylene homo- or co-polymer at a constant level upon subjecting propylene alone or a mixture of propylene and another .alpha.-olefin copolymerizable with propylene as a monomer or monomer mixture to bulk polymerization in the presence of hydrogen as a molecular weight modifier in a reaction tank equipped with a reflux condenser.
    Type: Grant
    Filed: October 17, 1988
    Date of Patent: March 24, 1992
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Tadashi Asanuma, Ichiro Fujio, Nobutaka Uchikawa
  • Patent number: 4772661
    Abstract: A block copolymer of propylene is produced by using propylene itself as a liquid medium, conducting continuous polymerization (former-stage polymerization) of propylene alone or propylene and a small amount of ethylene at first and then conducting batchwise copolymerization (latter-stage polymerization) of ethylene and propylene. The amount of an activity improver to be added to a polymerization tank for the latter-stage polymerization and/or the polymerization time of the latter-stage polymerization are controlled in accordance with the amount of a slurry transferred from a polymerization tank for the former-stage polymerization to the polymerization tank for the latter-stage polymerization so as to maintain the ratio of the amount of the polymer polymerized by the former-stage polymerization to the amount of the polymer polymerized by the latter-stage polymerization constant in the block copolymer.
    Type: Grant
    Filed: November 25, 1986
    Date of Patent: September 20, 1988
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Tadashi Asanuma, Mitsuru Ito, Kaneo Ito, Shigeru Kimura, Nobutaka Uchikawa, Ichiro Fujio