Patents by Inventor Hiroaki Ohgi

Hiroaki Ohgi 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: 6777528
    Abstract: A process for producing a polycarbonate resin which comprises performing melt polycondensation of pentacyclopentadecanedimethanol or pentacyclopentadecanedimethanol and diol with carbonic acid diester in the presence of a catalyst containing at least one compound selected from the group consisting of zinc compounds, tin compounds, lead compounds, zirconium compounds and hafnium compounds.
    Type: Grant
    Filed: March 8, 2002
    Date of Patent: August 17, 2004
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Takayasu Fujimori, Hiroaki Ohgi, Masamichi Mizukami
  • Publication number: 20020132968
    Abstract: A process for producing a polycarbonate resin which comprises performing melt polycondensation of pentacyclopentadecanedimethanol or pentacyclopentadecanedimethanol and diol with carbonic acid diester in the presence of a catalyst containing at least one compound selected from the group consisting of zinc compounds, tin compounds, lead compounds, zirconium compounds and hafnium compounds.
    Type: Application
    Filed: March 8, 2002
    Publication date: September 19, 2002
    Applicant: MITSUBISHI GAS CHEMICAL COMPANY, INC.
    Inventors: Takayasu Fujimori, Hiroaki Ohgi, Masamichi Mizukami
  • Patent number: 6169197
    Abstract: A process for separation between dialkyl carbonate and alkyl carbamate which comprises adding an aromatic hydroxy compound to a liquid comprising alkyl carbamate having an alkyl group having 3 to 6 carbon atoms and dialkyl carbonate having alkyl group having 3 to 6 carbon atoms to obtain a mixed liquid, and distilling the mixed liquid thus obtained in a distillation column to obtain a mixture comprising the dialkyl carbonate and the aromatic hydroxy compound from a top section of the distillation column and a liquid comprising the alkyl carbamate from a bottom section of the distillation column.
    Type: Grant
    Filed: June 15, 1999
    Date of Patent: January 2, 2001
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Takuo Ohshida, Hiroaki Ohgi, Yoshihisa Arai, Masamichi Mizukami
  • Patent number: 6031122
    Abstract: A process for producing a dialkyl carbonate which comprises reacting at least one member selected from the group consisting of urea and alkyl carbamate with alcohol in the presence of both a catalyst and a high boiling point organic compound having a boiling point of 180.degree. C. or above.
    Type: Grant
    Filed: March 12, 1998
    Date of Patent: February 29, 2000
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Masamichi Mizukami, Yoshihisa Arai, Hidefumi Harada, Takuo Ohshida, Hiroaki Ohgi
  • Patent number: 5980445
    Abstract: A process for producing diaryl carbonate which comprises (A) a step for producing dialkyl carbonate represented by the general formula RO--CO--OR by reacting urea with alkyl alcohol represented by the general formula ROH, (B) a step for producing both alkyl aryl carbonate represented by the general formula RO--CO--OAr and diaryl carbonate represented by the general formula ArO--CO--OAr by reacting dialkyl carbonate produced in the above step (A) with an aromatic hydroxy compound represented by the general formula ArOH, and (C) a step for producing diaryl carbonate represented by the general formula ArO--CO--OAr by allowing to conduct disproportionation reaction of unreacted alkyl aryl carbonate produced in the above step (B), wherein R shows an alkyl group and Ar shows a non-substituted phenyl group or a phenyl group substituted by alkyl group, alkoxy group, aryl group, aryloxy group or halogen.
    Type: Grant
    Filed: November 6, 1997
    Date of Patent: November 9, 1999
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Masamichi Mizukami, Yoshihisa Arai, Hidefumi Harada, Takuo Ohshida, Hiroaki Ohgi
  • Patent number: 5714627
    Abstract: A process for producing an aromatic carbonate which comprises: reacting a dialkyl carbonate represented by general formula (1) with an aromatic carboxylic acid aryl ester represented by general formula (2) in the presence of a catalyst to produce an aromatic carbonate represented by one or both of general formulae (3) and (4):R--OCOO--R (1)Ar'--COO--Ar (2)Ar--OCOO--R (3)Ar--OCOO--Ar (4)wherein R represents an alkyl group having from 1 to 4 carbon atoms, and Ar and Ar' each represents an unsubstituted phenyl group or a phenyl group substituted by a substituent selected from the group consisting of alkyl, alkoxy, aryl, aryloxy and a halogen atom.
    Type: Grant
    Filed: August 27, 1996
    Date of Patent: February 3, 1998
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Masamichi Mizukami, Takuo Ohshida, Hiroaki Ohgi, Hidefumi Harada