Ube Industries, Inc.

Hirofumi Ii

Shuji Tanaka

Ryoji Sugise

Keigo Nishihira

Takashi Doi

Katsumasa Harada

Satoru Fujitsu

Koichi Kashiwagi

Yuki Nishida

Kazuaki Mii

Masayuki Nishio

Shinichi Yoshida

Yuya Fukui

Kohichi Kashiwagi

Yoichi Imbe

Tomoyuki Itou

Yoshiki Kawamura

Toshiyuki Matsushita

Akira Hino

Yutaka Asada

Naoto Nakao

Koji Takebayashi

Koji Okano

Yohei Shimasaki

Takamasa Miyazaki

Tomoyuki Ito

Tadaaki Kaneko

Katsuyoshi Kudou

Kazuki Yamamoto

Kazuo Miyamoto

Tatsuya Naitou

A carbonate ester purification apparatus including a first distillation column in which an alcohol and a first solution containing a carbonate ester and formaldehyde, or a first solution containing a carbonate ester, formaldehyde and an alcohol is supplied to obtain a distillate containing the formaldehyde and the alcohol from a column top part while obtaining a carbonate ester solution with a lower content of formaldehyde than in the first solution from a column bottom part, a reactor having a catalyst for producing an acetal and/or a hemiacetal by reacting the formaldehyde to the alcohol and a reflux part refluxing a fluid containing the acetal and/or the hemiacetal to the first distillation column.

Carbonate ester purification method, carbonate ester solution production method, and carbonate ester purification apparatus

A method manufactures diethyl carbonate by reaction distillation where transesterification and distillation are simultaneously performed in a multistage reaction distillation column provided with a catalyst introduction port and a raw material introduction port located below the catalyst introduction port, wherein: (a) the reaction is performed in a countercurrent flow format in which contact is brought about between a transesterification catalyst, dimethyl carbonate, and ethanol; (e) 1 to 250 mmol of catalyst is used per mole of dimethyl carbonate; (f) the ratio of the volume of air in the catalyst introduction port and the raw material introduction port regarding the volume of air in the reaction distillation part is 0.1 to 0.9; (g) the recirculation ratio in the reaction distillation column is 0.5 to 10; and (h) the temperature of the top part of the column and the reaction distillation part is 60 to 100&#xb0; C.

Method of manufacturing diethyl carbonate

Disclosed is a process for preparing a diaryl oxalate which comprises the step of transesterifying a dialkyl oxalate or/and an alkylaryl oxalate with an aryl alcohol in the presence of a tetra(aryloxy)titanium as a catalyst, wherein the tetra(aryloxy)titanium is fed into a reaction system of the transesterification as an aryl alcohol solution of the tetra(aryloxy)titanium which is prepared by reacting a tetraalkoxy titanium and an excess amount of the aryl alcohol and removing a by-producing alkyl alcohol.

Process for preparing diaryl oxalate

A method is provided for producing highly pure 1,6-hexanediol in which the contents of impurities such as 1,4-cyclohexanediol, 1,5-hexanediol, 1,2-cyclohexanediol, 1,7-pentanediol, 1,5-pentanediol and high boiling point components are significantly reduced. The process contains the steps of (1) treating an aqueous extraction concentrate of a reaction mixture obtained by oxidation of cyclohexane with a lower alcohol to esterify monocarboxylic acids and dicarboxylic acids contained in the extract, and simultaneously removing and separating by distillation water, excess lower alcohols and carboxylic acid esters; (2) converting oligomer esters contained in the bottom liquid to carboxylic acid esters by depolymerizing the oligomer esters at a high temperature and high pressure in the presence of a lower alcohol and a catalyst; and (3) hydrogenating the carboxylic acid esters distilled off in step (1) and the carboxylic acid esters obtained in step (2) either respectively or collectively to convert to 1,6-hexanediol.

Production process of 1,6-hexanediol

An alkyl nitrite is produced with high efficiency by bringing a nitrogen monoxide gas into contact with an aqueous solution of an alkyl alcohol and nitric acid in a reactor, which aqueous solution may be a liquid fraction generated in an alkyl nitrite-production process in which an alkyl alcohol is reacted with nitrogen monoxide and oxygen in a reaction column

Process for producing alkyl nitrite

An alkyl nitrite is produced with high efficiency by bringing a nitrogen monoxide gas into contact with an aqueous solution of an alkyl alcohol and nitric acid in a reactorwhich aqueous solution may be a liquid fraction generated in an alkyl nitrite-production process in which an alkyl alcohol is reacted with nitrogen monoxide and oxygen in a reaction column

A composition consisting essentially of a diaryl carbonate and contains a furan ring-containing compound in an amount of not more than 1 ppm is favorably employable for producing less colored polycarbonate.

Diaryl carbonate product and production of polycarbonate

A process for preparing a diaryl carbonate from a diaryl oxalate in a liquid phase by decarbonylation is conducted by the steps of:

Process for preparing diaryl carbonate

A diaryl carbonate with a high degree of purity is produced at a high yield by (A) subjecting (a) a diaryl oxalate and a phenol compound or (b) an alkylaryl oxalate to transesterification reaction in one or two stages in the presence of a catalyst to prepare a diaryl oxalate, while removing a by-product from the reaction system; (B) collecting the diaryl oxalate from the resultant reaction product mixture of the step (A); (C) subjecting the diaryl oxalate to a decarbonylation reaction, preferably in the presence of a phosphorous compound-containing catalyst, to convert the diaryl oxalate to a corresponding diaryl carbonate, while removing a reaction by-product comprising carbon monoxide from the reaction system; and (D) collecting the diaryl carbonate from the reaction product mixture of the step (C).

Process for producing a diaryl carbonate

A novel crystalline adduct of diphenyl oxalate and phenol in a molar ratio of 1:2 and having a high purity is produced by melting a mixture containing diphenyl oxalate and phenol at a temperature of 100.degree. C. or more; cooling the melt to a temperature of less than 100.degree. C. to allow a resultant adduct of diphenyl oxalate and phenol in a molar ratio of 1:2 to crystallize and deposit from the melt; and collecting the crystalline adduct. Diphenyl oxalate with a high purity is produced by melting the crystalline adduct to dissociate it into diphenyl oxalate and phenol, and evaporating away the dissociated phenol from the melt to collect the dissociated diphenyl oxalate.

Diphenyl oxalate-phenol adduct, process for producing the adduct and

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Ube, Japan

Hirofumi Ii