Patents by Inventor Takashi Yokomatsu

Takashi Yokomatsu 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).

  • Process for the preparation of phosphonite compounds
    Patent number: 6437164
    Abstract: Biphenyl and phosphorus trichloride are reacted in the presence of aluminum chloride, a hydrogen chloride gas generated is removed, a pyridine is added, excess phosphorus trichloride is removed, a resulting reaction product containing the obtained phosphine compound of the formula: and a phenol compound of the formula: wherein R is a hydrogen atom or methyl and R1 and R2 are each a hydrogen atom or alkyl having 1 to 5 carbon atoms, are reacted in the presence of a base as a deacidifying agent, and hydrochloride of this base and a pyridine-aluminum chloride complex are removed. By this method, a high quality phosphonite compound containing phosphinobiphenylene of the formula: can be produced safely in a high yield.
    Type: Grant
    Filed: July 6, 2001
    Date of Patent: August 20, 2002
    Assignee: Yoshitomi Fine Chemicals, Ltd.
    Inventors: Masataka Yamamoto, Masahiro Kasagi, Takashi Yokomatsu, Akio Mishima, Yoshihiro Ozaki