Patents by Inventor Akira Kubotsu

Akira Kubotsu 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: 6066396
    Abstract: A vinyl-alcohol-based polymer and vinyl-halide-based polymer are dissolved in a common organic solvent for them, a typical example of which is dimethylsulfoxide, to obtain a dope wherein a solution of the vinyl-halide-based polymer having a particle size of 1-50 .mu.m is present in the solution of the vinyl-alcohol-based polymer. This dope is spun into a low temperature solidifying bath comprising a solidifying solvent such as methanol, and the organic solvent. The resultant is subjected to extraction, drying, dry heat drawing, and optional heat shrinking or acetalization to obtain fiber. In the fiber thus obtained, the vinyl-alcohol-based polymer makes sea phases, and the vinyl-halide-based polymer makes island phases whose size is 0.1-3 .mu.m. The crystallinity degree of the vinyl-alcohol-based polymer is 65-85%.The polyvinyl-alcohol-based flame retardant fiber is useful for clothes, industrial materials, living materials and the like.
    Type: Grant
    Filed: June 7, 1999
    Date of Patent: May 23, 2000
    Assignee: Kuraray Co., Ltd.
    Inventors: Shinya Inada, Masahiro Satoh, Hayami Yoshimochi, Akio Ohmory, Isao Tokunaga, Akira Kubotsu, Masakazu Nishiyama, Tomoyuki Sano
  • Patent number: 5431794
    Abstract: A metal film high in reflectivity and excellent in adhesion to a synthetic resin substrate even in the case where the metal film is sufficiently thin, is formed on a surface of the substrate by sputtering a metal target by ions through an inert gas plasma in a vacuum vessel, wherein the substrate is covered with an electrostatic shield during the sputtering.
    Type: Grant
    Filed: November 5, 1993
    Date of Patent: July 11, 1995
    Assignees: Nissin Electric Co.,, Kuraray Co., Ltd.
    Inventors: Shigeo Matsumaru, Toru Watanabe, Akira Kubotsu, Shuichi Nogawa, Kiyoshi Ogata, Daisuke Inoue
  • Patent number: 5283095
    Abstract: A metal film high in reflectivity and excellent in adhesion to a synthetic resin substrate even in the case where the metal film is sufficiently thin, is formed on a surface of the substrate by sputtering a metal target through an inert gas ion beam drawn out of an ion source in a vacuum vessel. An aluminum film coated matter formed by coating a surface of a synthetic resin substrate with an aluminum film, is characterized in that the aluminum film contains aluminum crystals at a portion in the film at a depth of not more than 600 .ANG. from a film surface thereof which contacts with the substrate. The aluminum crystals has a relation in which a crystal axis <111> perpendicular to a (111) plane is perpendicular or substantially perpendicular to the film surface. Also, the aluminum crystals exhibits a diffraction X-ray spectrum of a (111) plane when measured by X-ray diffraction according to a diffractometer method under the following conditions: target: Cu, X-ray type: K.alpha.
    Type: Grant
    Filed: April 10, 1992
    Date of Patent: February 1, 1994
    Assignees: Nissin Electric Co., Ltd., Kuraray Co., Ltd.
    Inventors: Shigeo Matsumaru, Toru Watanabe, Akira Kubotsu, Shuichi Nogawa, Kiyoshi Ogata, Daisuke Inoue
  • 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: 4560715
    Abstract: Incorporation in a thermoplastic resin of a mass of mica flakes having a median shape factor of not less than 0.76, an average particle size of not more than 2,000 .mu.m and an average aspect ratio of not less than 10 followed by molding gives moldings which are high not only in mechanical strength but also in strength at weld parts. Incorporation of said mica flake mass in a thermosetting resin followed by molding affords moldings very high in strength as well as in modulus of elasticity.
    Type: Grant
    Filed: March 14, 1984
    Date of Patent: December 24, 1985
    Assignee: Kuraray Co., Ltd.
    Inventors: Ryuhei Ueeda, Kiyonobu Fujii, Akira Kubotsu, Shunji Kaneda, Kenji Okuno
  • Patent number: 4522873
    Abstract: A fibrous structure having a roughened surface and a process for producing the same are disclosed. Upon dying, the fibrous structure is greatly improved in color depth. In addition, it gives one a more scrooping feeling than silk does.The fibrous structure has surface irregularities whose structure is such that the distance between the adjacent projections is 0.01 to 0.7 micrometer and the area of the concave portions is 0.1 to 0.8 square micrometer in 1 square micrometer of the irregularities.The fibrous structure is produced by the steps of attaching fine particles to the fiber surface in an amount of 0.001 to 10 wt % based on the fiber, said fine particles having an average primary particle diameter smaller than 0.
    Type: Grant
    Filed: February 28, 1984
    Date of Patent: June 11, 1985
    Assignee: Kuraray Co., Ltd.
    Inventors: Takao Akagi, Shinji Yamaguchi, Akira Kubotsu
  • Patent number: 4385094
    Abstract: There is provided a hollow fiber membrane of ethylene-vinyl alcohol copolymer which is produced by a process comprising extruding a spinning solution of an ethylene-vinyl alcohol copolymer in a solvent selected from the group consisting of dimethylsulfoxide, dimethylacetamide, pyrrolidone, N-methylpyrrolidone and mixtures thereof through a hollow fiber spinneret while a liquid coagulant is introduced into a central aperture of said spinneret, passing the spun fiber through a gaseous atmosphere in a manner such that the fiber is drawn 0.5 to 20 times its extrusion rate and then coagulating said fiber in a coagulating bath at a temperature within the range satisfying the following relationship:when 15.ltoreq.C.ltoreq.40, 1/4C+20.ltoreq.T.ltoreq.1/4C+57wherein C denotes the copolymer concentration of the spinning solution (wt. %) and T denotes the coagulation temperature (.degree.C.).
    Type: Grant
    Filed: April 21, 1980
    Date of Patent: May 24, 1983
    Assignee: Kuraray Co., Ltd.
    Inventors: Taku Tanaka, Shuzo Yamashita, Hirokuni Tanii, Akira Kubotsu, Syuji Kawai
  • Patent number: 4362677
    Abstract: A hollow fiber membrane made of an ethylene-vinyl alcohol copolymer is provided, which is characterized in that, when observed in a dry state with an electron microscope, the hollow fiber membrane has at least one dense, active layer (or skin layer) on the inside and/or outside surface thereof and further a three-layered structure comprising two layers respectively contacting the inside and outside surfaces and each consisting of a plurality of particles bonded together and having particle sizes of 0.01 to 2 microns and a substantially particle-free homogeneous layer lying between the two layers.
    Type: Grant
    Filed: June 4, 1981
    Date of Patent: December 7, 1982
    Assignee: Kuraray Co., Ltd.
    Inventors: Shuzo Yamashita, Taku Tanaka, Hirokuni Tanii, Akira Kubotsu, Syuji Kawai
  • Patent number: 4317729
    Abstract: A hollow fiber membrane made of an ethylene-vinyl alcohol copolymer is provided, which is characterized in that, when observed in a dry state with an electron microscope, the hollow fiber membrane has at least one dense, active layer (or skin layer) on the inside and/or outside surface thereof and further a three-layered structure comprising two layers respectively contacting the inside and outside surfaces and each consisting of a plurality of particles bonded together and having particle sizes of 0.01 to 2 microns and a substantially particle-free homogeneous layer lying between the two layers.
    Type: Grant
    Filed: April 21, 1980
    Date of Patent: March 2, 1982
    Assignee: Kuraray Co., Ltd.
    Inventors: Shuzo Yamashita, Taku Tanaka, Hirokuni Tanii, Akira Kubotsu, Syuji Kawai
  • Patent number: 4254182
    Abstract: A polyester fiber having an irregularly uneven random surface, having nonuniform recesses and projections forming said surface satisfying the requirement 0.2 micron<X<0.7 micron where X is the planar distance from the deepest point of a recess to the deepest point of another recess located adjacently thereof in the circumferential direction perpendicular to the fiber axis and being present at the density of 10 to 50 in each planar distance of 10 microns in the circumferential direction perpendicular to the fiber axis. Said recesses and projections constituting the random surface have additional microfine recesses and projections within the size range of 50 to 200 millimicrons. A method for producing a polyester synthetic fiber having the above surface structure is also described. The fiber thus obtained features excellent dyeability, i.e. the development and depth of color, and an excellent surface hand.
    Type: Grant
    Filed: March 2, 1979
    Date of Patent: March 3, 1981
    Assignee: Kuraray Co., Ltd.
    Inventors: Shinji Yamaguchi, Takao Akagi, Takaakira Tsuji, Katsura Maeda, Masao Kawamoto, Akira Kubotsu