Patents by Inventor Yoshifumi Tsujimoto

Yoshifumi Tsujimoto 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).

  • Non-aqueous electrolyte battery separator
    Patent number: 6447958
    Abstract: A non-aqueous electrolyte battery separator comprising a heat-resistant nitrogen-containing aromatic polymer and a ceramic powder.
    Type: Grant
    Filed: April 26, 1999
    Date of Patent: September 10, 2002
    Assignee: Sumitomo Chemical Co., Ltd.
    Inventors: Yasuo Shinohara, Yoshifumi Tsujimoto, Tsuyoshi Nakano
  • Prepreg process for producing the same and printed circuit substrate/board using the same
    Patent number: 6033765
    Abstract: The present invention provides a printed circuit substrate comprising a lightweight prepreg and a conductive layer. The prepeg having uniform formation, low linear thermal expansion coefficient and good mechanical strength, comprising a porous para-oriented aromatic polyamide film and a thermoplastic resin and/or a thermosetting resin, the porous para-oriented aromatic polyamide film being impregnated with the thermoplastic resin and/or the thermosetting resin, a process for producing the same, and a printed circuit substrate/board using the same.
    Type: Grant
    Filed: June 23, 1998
    Date of Patent: March 7, 2000
    Assignee: Sumitomo Chemical Company, Limited
    Inventors: Tsutomu Takahashi, Yoshifumi Tsujimoto, Hiroaki Kumada, Hiroyuki Sato
  • Para-oriented aromatic polyamide porous film
    Patent number: 5856426
    Abstract: A para-oriented polyamide porous film comprising a fibril having a diameter of not more than 1.mu., with fibrils planarly arranged as a network or nonwoven fabric and laminated in a layer, the thermal linear expansion coefficient at 200.degree.-300.degree. C. within .+-.50.times.10.sup.-6 /.degree.C. and 30-95% vacant spaces. Also, a battery separator using the porous film. Also, a production process of: (a) forming a film-like material from a solution containing 1-10% of a para-oriented aromatic polyamide having an inherent viscosity of 1.0-2.8 dl/g and 1-10% of a chloride of an alkali metal or an alkali earth metal in a polar amide or polar urea solvent; (b) maintaining the film-like material at not less than 20.degree. C. and not more than -5.degree. C.
    Type: Grant
    Filed: November 25, 1996
    Date of Patent: January 5, 1999
    Assignee: Sumitomo Chemical Company, Limited
    Inventors: Tsutomu Takahashi, Tatsuo Tateno, Yoshifumi Tsujimoto
  • Prepreg, process for producing the same and printed circuit substrate/board using the same
    Patent number: 5851646
    Abstract: The present invention provides a lightweight prepreg having uniform formation, low linear thermal expansion coefficient and good mechanical strength, comprising a porous para-oriented aromatic polyamide film and a thermoplastic resin and/or a thermosetting resin, the porous para-oriented aromatic polyamide film being impregnated with the thermoplastic resin and/or the thermosetting resin, a process for producing the same, and a printed circuit substrate/board using the same.
    Type: Grant
    Filed: October 15, 1996
    Date of Patent: December 22, 1998
    Assignee: Sumitomo Chemical Company, Limited
    Inventors: Tsutomu Takahashi, Yoshifumi Tsujimoto, Hiroaki Kumada, Hiroyuki Sato