Patents by Inventor Hiroshi Narukawa

Hiroshi Narukawa 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: 5133916
    Abstract: Provided are a polyvinyl alcohol fiber having a specific higher order structure, obtained by having the orientation and arrangement of molecular chains forming the fiber which comprises a crystalline region and an amorphous region lie in specific ranges to thereby making the fiber have a break-ing temperature in hot water of at least 125.degree. C., or further at least 130.degree. C. and be excellent in abrasion resistance, while maintaining the tenacity and the modulus of the fiber at high levels; and a process for producing the same.
    Type: Grant
    Filed: April 20, 1989
    Date of Patent: July 28, 1992
    Assignee: Kuraray Co., Ltd.
    Inventors: Hirofumi Sano, Akitsugu Akiyama, Hiroshi Narukawa
  • Patent number: 5110678
    Abstract: Provided is a high-performance PVA fiber and its production.Each filament of the PVA fiber of the present invention having a structure comprising an aggregate of substantially innumerable fibrils, the fiber has high strength, elastic modulus, and resistances to fatigue, hot water and chemicals and can be pulpified while keeping its excellent features such as high strength. The PVA fiber of the present invention cannot, even drawn to a high ratio, be readily whitened by virtue of its fibril-aggregate structure, and can hence be made still higher in performances. The PVA fiber can be obtained by adding to a PVA solution a relatively large amount of surface active agent, and wet or dry-jet-wet spinning the thus prepared dope solution into an aqueous alkaline coagulating bath.
    Type: Grant
    Filed: April 20, 1990
    Date of Patent: May 5, 1992
    Assignee: Kuraray Company Limited
    Inventors: Hiroshi Narukawa, Akio Mizobe, Fumio Nakahara, Akira Kubotsu, Akitsugu Akiyama, Masakazu Nishiyama, Kenji Nagamatu, Hirotoshi Miyazaki
  • Patent number: 4604441
    Abstract: Polypropylene sheets of high impact resistance at low temperature and of improved formability characterized by specific parameters are described. Such polypropylene sheets are produced by spreading under pressure polypropylene sheets at a temperature within a very narrow range in the vicinity of the melting point of the propylene-based polymer.
    Type: Grant
    Filed: March 20, 1985
    Date of Patent: August 5, 1986
    Assignee: Kuraray Company, Ltd.
    Inventors: Ryuhei Ueeda, Kiyonobu Fujii, Hiroshi Narukawa
  • Patent number: 4555439
    Abstract: According to the present invention, rolled sheet-like materials having superior mechanical properties, in particular toughness and high-impact properties, as well as superior heat resistance and showing no whitening can be provided.Such rolled sheet-like materials are manufactured by isotropically rolling sheet-like materials, which were obtained by melting, blending and forming the mixture consisting of thermoplastic resin having the degree of crystallinity of 10% or more of 20 to 90% by weight and flaky fillers of 10 to 80% by weight, to orientate a part of crystals after it was melted at the melting point of said sheet-like materials and then recrystallizing the melted crystals under the rolled condition.
    Type: Grant
    Filed: January 13, 1984
    Date of Patent: November 26, 1985
    Assignee: Kuraray Company, Ltd.
    Inventors: Ryuhei Ueeda, Kiyonobu Fujii, Hiroshi Narukawa
  • Patent number: 4504531
    Abstract: An aluminum atom- and monocarboxylic acid residue-containing polyester is provided. Using the polyester as an adhesive or a base, laminates and laminated hollow vessels which comprise, as the constituent elements, the polyester and an ethylene-vinyl alcohol copolymer can be produced. The laminates and laminated hollow vessels are suitable for use as packaging materials or containers for food and drink.
    Type: Grant
    Filed: May 30, 1984
    Date of Patent: March 12, 1985
    Assignee: Kuraray Co., Ltd.
    Inventors: Yoshifumi Murata, Keishiro Igi, Hiroshi Narukawa, Masao Uetsuki, Satoshi Bando, Shuji Kawai, Kenji Shirano
  • Patent number: 4496714
    Abstract: An aluminum atom- and monocarboxylic acid residue-containing polyester is provided. Using the polyester as an adhesive or a base, laminates and laminated hollow vessels which comprise, as the constituent elements, the polyester and an ethylene-vinyl alcohol copolymer can be produced. The laminates and laminated hollow vessels are suitable for use as packaging materials or containers for food and drink.
    Type: Grant
    Filed: December 15, 1983
    Date of Patent: January 29, 1985
    Assignee: Kuraray Co., Ltd.
    Inventors: Yoshifumi Murata, Keishiro Igi, Hiroshi Narukawa, Masao Uetsuki, Satoshi Bando, Shuji Kawai, Kenji Shirano
  • Patent number: 4433020
    Abstract: A sheet-like material having excellent fire resistance and bending workability comprises 80 to 97% by weight of a non-flammable fibrous substance, and 3 to 20% by weight of a binder consisting essentially of a thermoplastic resin. The fibrous substance is orientated at an angle of 3.degree. to 80.degree.. The material has an intermediate layer containing at least 2% by weight of the binder and at least 25% of the average quantity of the binder in the material. A heat insulating material comprising such sheet-like materials is also disclosed. The sheet-like material, and the heat insulating material are manufactured by a wet sheet forming process in which a slurry containing the fibrous substance and the binder is fed to a carrier net or sheet at an angle of 5.degree. to 60.degree. thereto, whereby the fibers are orientated. Alternatively, the slurry is fed to the carrier net or sheet at an angle of 20.degree. to 45.degree., while a fluid is blown into the slurry to create turbulence therein.
    Type: Grant
    Filed: October 21, 1982
    Date of Patent: February 21, 1984
    Assignee: Kuraray Co., Ltd.
    Inventors: Hiroshi Narukawa, Rentaro Tada, Yasuhira Takeuchi, Osamu Ohara
  • Patent number: 4148781
    Abstract: A flexible building sheet product is prepared by dry molding a slurry comprising predominantly at least one binder component selected from the group consisting of thermoplastic resin emulsions and aqueous solutions of water-soluble polymers, said solutions containing cross-linking agents for said water-soluble polymers, and a matrix component comprising a calcium sulfate dihydrate powder.
    Type: Grant
    Filed: July 27, 1977
    Date of Patent: April 10, 1979
    Assignee: Kuraray Co., Ltd.
    Inventors: Hiroshi Narukawa, Yasuhira Takeuchi, Koichi Saito, Yoshio Ohfuji