Mitsubishi Gas Chemical Company, Inc.

Hiroaki Ohgi

Masamichi Mizukami

Takuo Ohshida

Hidefumi Harada

Yoshihisa Arai

Takayasu Fujimori

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.

Process for producing polycarbonate resin

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.

Process for separation between dialkyl carbonate and alkyl carbamate

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.

Process for producing dialkyl carbonate

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.

Process for producing diaryl carbonate

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):

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Tsukuba, Japan

Hiroaki Ohgi