Patents by Inventor Yoshihiro Tamba

Yoshihiro Tamba 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: 7462386
    Abstract: The leather-like sheet of the invention comprises a napped part of ultrafine fibers and a grainy part of nonporous elastic polymer randomly existing in the surface of a substrate prepared by infiltrating a porous polymer elastomer into a three-dimensionally intermingled nonwoven fabric of ultrafine fibers of not more than 0.5 dtex, and this is characterized in that the nonporous elastic polymer is infiltrated into the substrate to a depth thereof of from 5 to 20 ?m from the surface of the substrate. The production method of the invention is for producing a nubuck-type leather-like sheet of good surface abrasion resistance. A grainy part of resin and ultrafine fibers and a part of the ultrafine fibers are mingled on the surface of the substrate, and the sheet has an elegant and three-dimensional appearance like natural leather.
    Type: Grant
    Filed: July 23, 2002
    Date of Patent: December 9, 2008
    Assignee: Kuraray Co., Ltd.
    Inventors: Tsuyoshi Yamasaki, Hidekazu Andoh, Yoshihiro Tamba
  • Publication number: 20050125907
    Abstract: The substrate for artificial leathers of the invention comprises an entangled nonwoven fabric which is mainly made of bundles of polyamide microfine fibers and an elastic polymer which is impregnated into intervening spaces in the entangled nonwoven fabric. The single fiber fineness of polyamide microfine fibers is 0.2 dtex or less. The bundles of polyamide microfine fibers have an average tenacity of 3.5 cN/dtex or more and an average elongation of 60% or less. Despite its extremely low apparent specific gravity of 0.30 or less, the substrate for artificial leathers exhibits high mechanical properties as evidenced by a tear strength of 50 N/mm or more. Thus, the substrate for artificial leathers is well balanced between the mechanical properties, feel and light weight which are required particularly in sport shoes applications to an extent not conventionally attained.
    Type: Application
    Filed: December 2, 2004
    Publication date: June 16, 2005
    Applicant: Kuraray Co., Ltd.
    Inventors: Tsuyoshi Yamasaki, Norio Makiyama, Yoshihiro Tamba
  • Publication number: 20040224122
    Abstract: The leather-like sheet of the invention comprises a napped part of ultrafine fibers and a grainy part of nonporous elastic polymer randomly existing in the surface of a substrate prepared by infiltrating a porous polymer elastomer into a three-dimensionally intermingled nonwoven fabric of ultrafine fibers of not more than 0.5 dtex, and this is characterized in that the nonporous elastic polymer is infiltrated into the substrate to a depth thereof of from 5 to 20 &mgr;m from the surface of the substrate.
    Type: Application
    Filed: January 30, 2004
    Publication date: November 11, 2004
    Inventors: Tsuyoshi Yamasaki, Hidekazu Andoh, Yoshihiro Tamba
  • Patent number: 6767853
    Abstract: A fibrous substrate for artificial leather, containing microfine fiber bundles, each of which is composed of 3-50 microfine fibers (A) containing an elastic polymer and having an average fineness of 0.5 denier or less and 15 or more microfine fibers (B) containing a non-elastic polymer and having an average fineness of 0.2 denier or less. The microfine fiber bundles satisfy the following conditions (1)-(3): (1) the ratio of the number of strands of the A to the number of strands of the B in cross sections of the bundles (A/B) is 1/5 or less, (2) the ratio of the weight of the A to the weight of the B in the bundles (A/B) is 10/90-60/40, and (3) the microfine fibers (B) containing the non-elastic polymer encircle each of the microfine fibers (A) comprising the elastic polymer.
    Type: Grant
    Filed: July 3, 2000
    Date of Patent: July 27, 2004
    Assignee: Kuraray Co., Ltd.
    Inventors: Kimio Nakayama, Tsuyoshi Yamasaki, Yoshihiro Tamba
  • Patent number: 6517938
    Abstract: An artificial leather sheet substrate comprising: a fiber entangled nonwoven fabric composed of bundles of a polyamide-based microfine fibers comprising a polyamide or a polyamide composition having a hot toluene swelling degree of 2 to 10%, and having a fineness of 0.1 decitex or less; and an elastic polymer and a releasing agent between the bundles, the releasing agent being also added to the inside of the bundles. This leather-like sheet substrate is soft and is excellent in denseness, dyeability and color fastness. The sheet is suitable, as a suede-like artificial leather or a grain surface like artificial leather, for fields for which high quality is required, for example, for clothing. The sheet is high in denseness of surface napped fiber and is excellent in hand touch, writing effect and draping ability, especially as a suede-like artificial leather.
    Type: Grant
    Filed: March 16, 2000
    Date of Patent: February 11, 2003
    Assignee: Kurray Co., Ltd.
    Inventors: Hidekazu Andoh, Tsuyoshi Yamasaki, Yoshihiro Tamba
  • Patent number: 6322851
    Abstract: In a process for making a leather-like sheet by impregnating a fibrous substrate with a polyurethane emulsion, heat gellable polyurethane emulsion having a specific modulus of elasticity is employed as the polyurethane emulsion, and either of following methods (1) and (2) is also employed: (1) before impregnation of the polyurethane emulsion, the fibrous substrates are pretreated with a surfactant having a function of inhibiting adhesion between fibers and polyurethane (2) in addition to the above modulus of elasticity, the polyurethane emulsion has a specific &agr; dispersion temperature, the fibrous substrates are composed of microfine fiber-forming fibers, and after coagulation of polyurethane emulsion, the fibers are converted to microfine fibers. The leather-like sheets obtained according to this invention exhibits natural leather-like softness and hand touchness as well as excellent physical properties such as bending fatigue resistance.
    Type: Grant
    Filed: June 11, 1999
    Date of Patent: November 27, 2001
    Assignee: Kuraray Co., Ltd.
    Inventors: Hideaki Adachi, Mitsuru Kato, Yoshihiro Tamba