Mitsubishi Gas Chemical Company, Inc.

Futoshi Kawataka

Kenichi Nakamura

Yoshikazu Shima

Kazuhiro Yamada

Wataru Ueno

Process for preparing &agr;-hydroxycarboxylate

A process for continuously producing an alkyl ester of acrylic or methacrylic acid by ester interchange reaction represented by the following reaction scheme: ##STR1## wherein R.sup.1 is hydrogen or methyl, R.sup.2 is an alkyl having 1 to 6 carbon atoms, R.sup.3 is an alkyl having 2 to 20 carbon atoms or a mono- or polyhydroxyalkyl having 2 to 20 carbon atoms such that R.sup.2 OH has a boiling point lower than that of R.sup.3 OH. The reaction is continuously carried out in a continuous multi-stage distillation column while simultaneously removing the low-boiling R.sup.2 OH from the reaction zone by distillation, thereby shifting the equilibrium toward the product side to enhance the production of the target alkyl ester.

Process for continuously producing ester of acrylic or methacrylic acid

Provided is a process for producing acetic acid by carrying out reaction of methyl formate in the presence of a Group VIII metal catalyst, at least one iodine compound, acetic acid and carbon monoxide, continuously drawing a reaction mixture from a reactor, introducing the reaction mixture into a flash distillation zone, separating an evaporated component and an unevaporated component, recycling the unevaporated component to the reaction zone, and obtaining acetic acid from the evaporated component, wherein formic acid and methyl formate are allowed to coexist in the flash distillation zone and/or the recycling zone. According to this process, no loss of methyl formate and formic acid is caused and only methyl formate is used as a starting material with basically requiring no supply of carbon monoxide.

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Ibaraki-ken, Japan

Futoshi Kawataka