Patents by Inventor Tateyo Sasaki

Tateyo Sasaki 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: 5840389
    Abstract: A molded article obtained by blow molding a propylene having a substantially syndiotactic structure or a resin composition comprising a polypropylene having a substantially syndiotactic structure and a copolymer of ethylene and propylene, and a multi-layer molded article obtained from this resin composition in which at least one surface of the molded article is a polypropylene layer having the substantially syndiotactic structure.
    Type: Grant
    Filed: February 18, 1997
    Date of Patent: November 24, 1998
    Assignee: Mitsui Chemicals, Inc.
    Inventors: Tadashi Asanuma, Tateyo Sasaki, Shosuke Nakanishi
  • Patent number: 5759469
    Abstract: A molded article of a syndiotactic polypropylene having excellent transparency in which a melting point attributed to the polypropylene having the syndiotactic structure measured at a heating rate of 10.degree. C./minute by differential scanning thermal analysis is represented by a substantially single peak, the aforesaid molded article being prepared by heating, melting and then hot-molding a homopolymer of propylene or a copolymer of propylene and a small amount of another olefin, which have a substantially syndiotactic structure, or a mixture of the homopolymer or the copolymer and a small amount of a polypropylene having a substantially isotactic structure, followed by quenching, or, after these steps, additionally subjecting the above molded article to a heat treatment at a temperature of less than its melting point. A method for preparing the above molded article is also disclosed here.
    Type: Grant
    Filed: September 25, 1996
    Date of Patent: June 2, 1998
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Tadashi Asanuma, Tateyo Sasaki, Mitsuru Ito, Tetusnosuke Shiomura
  • Patent number: 5637367
    Abstract: A molded article obtained by blow molding a propylene having a substantially syndiotactic structure or a resin composition comprising a polypropylene having a substantially syndiotactic structure and a copolymer of ethylene and propylene, and a multi-layer molded article obtained from this resin composition in which at least one surface of the molded article is a polypropylene layer having the substantially syndiotactic structure.
    Type: Grant
    Filed: September 22, 1993
    Date of Patent: June 10, 1997
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Tadashi Asanuma, Tateyo Sasaki, Shosuke Nakanishi, Takeo Inoue
  • Patent number: 5591817
    Abstract: A molded article of a syndiotactic polypropylene having excellent transparency in which a melting point attributed to the polypropylene having the syndiotactic structure measured at a heating rate of 10.degree. C./minute by differential scanning thermal analysis is represented by a substantially single peak, the aforesaid molded article being prepared by heating, melting and then hot-molding a homopolymer of propylene or a copolymer of propylene and a small amount of another olefin, which have a substantially syndiotactic structure, or a mixture of the homopolymer or the copolymer and a small amount of a polypropylene having a substantially isotactic structure, followed by quenching, or, after these steps, additionally subjecting the above molded article to a heat treatment at a temperature of less than its melting point. A method for preparing the above molded article is also disclosed here.
    Type: Grant
    Filed: March 18, 1994
    Date of Patent: January 7, 1997
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Tadashi Asanuma, Tateyo Sasaki, Mitsuru Ito, Tetusnosuke Shiomura
  • Patent number: 5534595
    Abstract: Disclosed is a syndiotactic propylene copolymer containing 0.01 to 40 mol % of olefin units containing --OH group in the side chain. Of absorption peaks attributed to the methyl groups of the propylene units on an absorption spectrum by .sup.13 C-NMR of the copolymer, the intensity of an absorption peak observed at about 20.2 ppm is 0.3 or more of the intensity of absorption peaks of all the methyl groups attributed to the propylene units. The copolymer is produced by copolymerizing propylene and an alkenylsilane or alkenylborane compound in the presence of a catalyst system comprising an asymmetric ligands-having transition metal compound and an aluminoxane, followed by heat-treating the resulting propylene-alkenylsilane copolymer in the presence of a trialkylamine oxide and KF.HF or oxidizing and decomposing the resulting propylene-alkenylborane compound copolymer. Also disclosed is a resin composition comprising the copolymer and other polyolefin(s).
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: July 9, 1996
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Tadashi Asanuma, Hiroshi Matsuzawa, Tateyo Sasaki, Kaoru Kawanishi
  • 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: 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: 5260395
    Abstract: A method for molding a polypropylene or a propylene copolymer having a syndiotactic structure which comprises the steps of melting, molding, if desired, quenching and then stretching a propylene homopolymer or a copolymer of propylene and a small amount of ethylene or another .alpha.-olefin which has a substantially syndiotactic structure, or a mixture of the same and a small amount of a polypropylene having a substantially isotactic structure. The molded and stretched article can be heated at a temperature of a molding temperature or more, while a load is applied to the article. Furthermore, the molded and stretched article, if desired, can be treated with a hydrocarbon vapor, while a load is applied to the article. The molded article obtained by the method of the present invention has a novel crystalline structure.
    Type: Grant
    Filed: August 11, 1992
    Date of Patent: November 9, 1993
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Tadashi Asanuma, Tateyo Sasaki, Mitsuru Ito, Shigeru Kimura, Takeo Inoue
  • 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: 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: 5200131
    Abstract: A method for molding a polypropylene or a propylene copolymer having a syndiotactic structure which comprises the steps of melting, molding, if desired, quenching and then stretching a propylene homopolymer or a copolymer of propylene and a small amount of ethylene or another .alpha.-olefin which has a substantially syndiotactic structure, or a mixture of the same and a small amount of a polypropylene having a substantially isotactic structure. The molded and stretched article can be heated at a temperature of a molding temperature or more, while a load is applied to the article. Furthermore, the molded and stretched article, if desired, can be treated with a hydrocarbon vapor, while a load is applied to the article. The molded article obtained by the method of the present invention has a novel crystalline structure.
    Type: Grant
    Filed: April 2, 1991
    Date of Patent: April 6, 1993
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Tadashi Asanuma, Tateyo Sasaki, Mitsuru Ito, Shigeru Kimura, Takeo Inoue
  • 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: 5132157
    Abstract: A stretched film of polypropylene which is excellent in transparency, substantially free of an antiblocking agent and at least uniaxially stretched and which is characterized in that it has uniformly distributed projections having a height ranging from 0.05 to 0.50 .mu. and a width ranging from 10 to 100 .mu. at least on the surface thereof as well as a method for preparing the foregoing stretched film of polypropylene which comprises the steps of forming, into a sheet, polypropylene which comprises a nucleating agent in an amount selected so that the crystallization temperature of polypropylene is increased by 1.degree.to 10.degree. C. by the addition thereof and then stretching the sheet at a temperature ranging from 140.degree. to 165.degree. C. are herein disclosed.
    Type: Grant
    Filed: May 21, 1990
    Date of Patent: July 21, 1992
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Tadashi Asanuma, Kazuhiko Yamamoto, Tateyo Sasaki, Takeo Inoue, Takayuki Yamada
  • Patent number: 4439567
    Abstract: There is provided a polyolefin resin composition for injection molding which comprises adding to polyolefin a condensate of sorbitol with an aldehyde compound and a lubricant of 1/20 to 1/2 parts by weight based on 1.0 part by weight of said condensate. Thereby polyolefin injection moldings with good transparency are obtained without bringing a foaming phenomenon.
    Type: Grant
    Filed: July 8, 1982
    Date of Patent: March 27, 1984
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Takeo Inoue, Jun Otsu, Tateyo Sasaki, Hiroyuki Doi, Keigo Suehiro