Patents by Inventor Shigenobu Yamaguchi

Shigenobu Yamaguchi 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 for production of 2-chloropyridine and 2,6-dichloropyridine
    Patent number: 5536376
    Abstract: A method for producing 2-chloropyridine and 2,6-dichloropyridine by the steps of mixing vaporized chlorine and vaporized water to obtain dilute chlorine; introducing the dilute chlorine and vaporized pyridine into a reactor; and reacting the vaporized pyridine with the dilute chlorine in a gas phase under ultraviolet rays irradiation. By the method, 2-chloropyridine and 2,6-dichloropyridine can be produced in high yields. The present invention is also directed to a method for separating 2,6-dichloropyridine from a mixture containing 2,6-dichloropyridine, 2-chloropyridine and pyridine by the step of carrying out distillation of the mixture containing 2,6-dichloropyridine, 2-chloropyridine and pyridine in the presence of water while adding sulfuric acid to a distillation column. Highly purified 2,6-dichloropyridine can be separated by the method.
    Type: Grant
    Filed: December 28, 1993
    Date of Patent: July 16, 1996
    Assignee: Sumitomo Seika Chemicals Co., Ltd.
    Inventors: Shigenobu Yamaguchi, Johji Ogasahara, Hiroyuki Hata, Ryoichi Tokura, Hiromoto Shigeta