Patents by Inventor Masayuki Koishi

Masayuki Koishi 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: 5849660
    Abstract: A catalyst (3) for purifying an automotive exhaust gas, in which inner and outer catalytic layers (5,6), each of which has a base material and a catalytic material held by the base material, are stratified on a honeycomb-type carrier (4). In the catalyst (3), the inner catalytic layer (5) contains a palladium component as the catalytic component. Further the inner catalytic layer (5) contains a nickel oxide component for preventing poisoning of the palladium component. On the other hand, though the outer catalytic layer (6) contains a rhodium component as the catalytic component, it does not contain a palladium component nor a nickel oxide component.
    Type: Grant
    Filed: February 26, 1996
    Date of Patent: December 15, 1998
    Assignee: Mazda Motor Corporation
    Inventors: Takashi Takemoto, Kazunari Komatsu, Taeko Shimizu, Hiroshi Yamada, Hiroshi Murakami, Masayuki Koishi, Yuki Koda, Keiko Matsui
  • Patent number: 5494878
    Abstract: A three-way catalyst is generally used in an automotive exhaust system. This catalyst has a sufficient total content of noble metal active species and is prevented from heat deterioration so that the activity of the noble metal active species can be well utilized at low temperatures to enable the catalyst to exhibit improved purification performance at the low temperatures. The catalyst comprises a first catalyst layer formed on the surface of a honeycomb-shaped carrier and containing Pd (palladium) and alumina (.gamma.-Al.sub.2 O.sub.3), and a second catalyst layer formed on the outer surface of the first catalyst layer and containing Pd and ceria (CeO.sub.2).
    Type: Grant
    Filed: January 27, 1994
    Date of Patent: February 27, 1996
    Assignee: Mazda Motor Corporation
    Inventors: Hiroshi Murakami, Yasuto Watanabe, Naoko Sakatani, Masayuki Koishi
  • Patent number: 5019546
    Abstract: A catalyst for purifying exhaust gas, comprising a catalyst carrier, a first coating layer formed on a surface of the catalyst carrier and mainly consisting of active alumina oxide containing platinum and rhodium and a second coating layer formed on a surface of the first coating layer and mainly consisting of palladium and composite powder including zirconium oxide and lanthanum oxide fixed on a surface of cerium oxide, and a method of manufacturing the catalyst.
    Type: Grant
    Filed: February 5, 1990
    Date of Patent: May 28, 1991
    Assignee: Mazda Motor Corporation
    Inventors: Hiroshi Murakami, Masayuki Koishi, Shoko Yatagai, Kazuko Yamagata