Patents by Inventor Keiji Shimoda

Keiji Shimoda 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 preparing prilled bisphenol A
    Patent number: 5371302
    Abstract: The invention relates to a process for preparing prilled bisphenol A by granulation which comprises adding compounds soluble in molten bisphenol A, not affecting adversely the melt color of bisphenol A to any significant extent, and have a melting point of 60.degree. C. or more to bisphenol A and granulating and also to a process which comprises adding the reaction mother liquor or cyrstallization mother liquor produced in the manufacturing step of bisphenol A to bisphenol A or the adduct of bispheol A and phenol or a mixture of bispheol A and phenol, removing the phenol, and granulating. The processes yield prilled bispheol A which have high strength and resist powdering.
    Type: Grant
    Filed: April 13, 1993
    Date of Patent: December 6, 1994
    Assignees: Nippon Steel Chemical Co., Ltd., Chiyoda Corp.
    Inventors: Hiroshi Yanai, Tadayoshi Matsuo, Masanori Nagase, Tsohikazu Maruyama, Toshihiko Furukawa, Katsuhiko Sakura, Yoshiaki Matsui, Takamasa Minami, Nobuo Moriya, Sachio Asaoka, Kouji Sakashita, Nobuyuki Suda, Keiji Shimoda, Susumu Yamamoto, Makoto Nomura
  • Process for the production of crystalline adduct of bisphenol A and phenol and apparatus therefor
    Patent number: 5368827
    Abstract: High purity, crystalline adduct of bisphenol A and phenol is produced multi-stage crystallization of a phenolic slurry of bisphenol A with a crystal separation and washing step being interposed between each of the two stages. Each of the crystallization stage includes a series of crystallization towers operated at decreasing temperatures. The crystallization of the slurry is performed by continuously discharging a portion of the slurry from each of the crystallization towers, introducing the discharged slurry into one or more coolers and then recycling the cooled slurry to the tower. Another portion of the slurry in each crystallization slurry is continuously discharged, heated for dissolving fine crystals of the adduct and then recycled to the crystallization tower so that large crystals are grown in each of the crystallization steps. An apparatus having a plurality of coolers and suitable for effecting the above crystallization is also disclosed.
    Type: Grant
    Filed: October 28, 1992
    Date of Patent: November 29, 1994
    Assignee: Chiyoda Corporation
    Inventors: Nobuo Moriya, Keiji Shimoda, Kouji Sakashita, Hiroaki Nishijima, Nobuhiro Onda, Takeshi Kouzaki
  • Process for the production of crystalline adduct of bisphenol A and phenol and apparatus therefor
    Patent number: 5345000
    Abstract: High purity, crystalline adduct of bisphenol A and phenol is produced multi-stage crystallization of a phenolic slurry of bisphenol A with a crystal separation and washing step being interposed between each of the two stages. Each of the crystallization stage includes a series of crystallization towers operated at decreasing temperatures. The crystallization of the slurry is performed by continuously discharging a portion of the slurry from each of the crystallization towers, introducing the discharged slurry into one or more coolers and then recycling the cooled slurry to the tower. Another portion of the slurry in each crystallization slurry is continuously discharged, heated for dissolving fine crystals of the adduct and then recycled to the crystallization tower so that large crystals are grown in each of the crystallization steps. An apparatus having a plurality of coolers and suitable for effecting the above crystallization is also disclosed.
    Type: Grant
    Filed: March 3, 1993
    Date of Patent: September 6, 1994
    Assignee: Chiyoda Corporation
    Inventors: Nobuo Moriya, Keiji Shimoda, Sachio Asaoka, Takao Kameda, Kouji Sakashita, Tetsuo Maejima, Makoto Yasui, Hiroaki Nishijima, Nobuhiro Onda, Takeshi Kouzaki