Patents by Inventor Taizo Nagahiro

Taizo Nagahiro 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: 5258441
    Abstract: A polyimide-based friction material which is excellent in heat resistance, abrasion resistance, stability of friction coefficient, can be readily obtained by molding, and is comprised of:(a) from 30 to 96 parts by weight of a thermoplastic polyimide resin essentially consisting of recurring units of the formula: ##STR1## (b) from 2 to 30 parts by weight of fluoro resin, and (c) from 2 to 40 parts by weight of calcium carbonate wherein the sum of components (a), (b) and (c) is 100 parts by weight.
    Type: Grant
    Filed: May 21, 1992
    Date of Patent: November 2, 1993
    Assignees: Mitsui Toatsu Chemicals, Inc., NTN-Rulon Corp.
    Inventors: Taizo Nagahiro, Noboru Umemoto
  • Patent number: 5206340
    Abstract: Integrated circuit sockets for use in a burn-in test are disclosed. The IC sockets are produced by injection molding of a specific polyimide having an inherent viscosity of 0.35 to 0.65 dl/g and essentially consisting of recurring units represented by the formula (I): ##STR1## wherein X is a radical selected from the group consisting of a bond, divalent hydrocarbon having from 1 to 10 carbon atoms, etc. and R is a tetravalent radical selected from the group consisting of an aliphatic radical having two or more carbon atoms, cycloaliphatic radical, monoaromatic radical etc.
    Type: Grant
    Filed: December 19, 1989
    Date of Patent: April 27, 1993
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Toshihiko Tsutsumi, Toshiyuki Nakakura, Taizo Nagahiro, Shuithi Morikawa, Nobuhito Koga
  • Patent number: 5098627
    Abstract: The present invention relates to a paper releasing guide-claw for a copying machine and a method for producing the same including molding a material containing from about 50-90% by weight of a polyimide consisting essentially of recurring units of the formula: ##STR1## from about 5 to about 40% by weight of a fibrous reinforcing material, and from about 5 to about 30% by weight of a solid lubricant, wherein the sum of the content of the fibrous reinforcing material and the solid lubricant is from about 10 to about 50% by weight, heat treating the molded guide-claw at a temperature of from about 250.degree. C. to about 340.degree. C. for a time sufficient to increase the density of the polyimide component by 1.5%.
    Type: Grant
    Filed: August 30, 1990
    Date of Patent: March 24, 1992
    Assignees: NTN-Rulon Industries Company Ltd., Mitsui Toatsu Chemicals, Inc.
    Inventors: Masao Yoshikawa, Taizo Nagahiro
  • Patent number: 4994544
    Abstract: A process for the production of polyimide fibers and polyimide fibers obtained by the process. The process includes thermal or chemical imidation of a polyamic acid which has been obtained by reacting a specific diamine and a particular tetracarboxylic dianhydride in the presence of a dicarboxylic anhydride represented by the following formula: ##STR1## wherein Z represents a divalent group selected from the group consisting of monocyclic aromatic groups, fused polycyclic aromatic groups and non-fused polycyclic aromatic groups with aromatic rings bonded together directly or via a crosslinking member.
    Type: Grant
    Filed: November 6, 1989
    Date of Patent: February 19, 1991
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Taizo Nagahiro, Masahiro Ohta, Shuichi Morikawa, Nubohito Koga, Shoji Tamai
  • Patent number: 4787993
    Abstract: This invention provides lubricants which perform stable operation even at high temperatures and under heavy loading. The lubricants are prepared by dispersing at least one of finely powdered resin selected from aromatic resin and polyimide resin into the fluid fats and oils. The flowable fats and oils may further contain molybdenum disulfide, organic molybdenum, boron nitride, or PTFE.
    Type: Grant
    Filed: July 2, 1987
    Date of Patent: November 29, 1988
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventor: Taizo Nagahiro