Patents by Inventor Akiyoshi Yokota

Akiyoshi Yokota 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).

  • Method of producing biphenyltetracarboxylic esters
    Patent number: 4338456
    Abstract: A biphenyltetracarboxylic tetraester, especially, 3,3',4,4'-biphenyltetracarboxylic tetraalkyl ester, is produced by bringing an orthophthalic diester, especially, orthophthalic dialkylester, into contact with a molecular oxygen-containing gas in the presence of a catalyst consisting of a mixture of a palladium salt with 2,2'-bipyridyl or a chelating reaction product of a palladium salt with 2,2'-bipyridyl, so as to promote oxidative coupling of the orthophthalic diester.
    Type: Grant
    Filed: February 18, 1981
    Date of Patent: July 6, 1982
    Assignee: Ube Industries, Ltd.
    Inventors: Hiroshi Itatani, Akinori Shiotani, Akiyoshi Yokota
  • Process for producing biphenyl compounds
    Patent number: 4294976
    Abstract: A biphenyl compound is produced from a corresponding aromatic monocyclic compound at a high yield thereof and a high percent selectivity thereto, by dehydrogenatively dimerizing the aromatic monocyclic compound with molecular oxygen in the presence of oxalic acid together with a organic palladium salt catalyst, under a pressure higher than the atmospheric pressure.
    Type: Grant
    Filed: August 31, 1979
    Date of Patent: October 13, 1981
    Assignee: UBE Industries, Ltd.
    Inventors: Hiroshi Itatani, Hataaki Yoshimoto, Akinori Shiotani, Akiyoshi Yokota, Motozoh Yoshikiyo
  • Method of producing biphenyltetracarboxylic esters
    Patent number: 4292435
    Abstract: A biphenyltetracarboxylic tetraester, especially, 3,3',4,4'-biphenyltetracarboxylic tetraalkyl ester, is produced by oxidative coupling an orthophthalic diester, especially, orthophthalic dialkylester, in a molecular oxygen-containing atmosphere in the presence of a catalyst consisting of a mixture of a palladium salt with 1,10-phenanthroline and/or 2,2'-bipyridyl or a chelating reaction product of a palladium salt with 1,10-phenanthroline or 2,2'-bipyridyl.
    Type: Grant
    Filed: May 21, 1980
    Date of Patent: September 29, 1981
    Assignee: Ube Industries, Ltd.
    Inventors: Hiroshi Itatani, Akinori Shiotani, Akiyoshi Yokota