The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 02, 1991
Filed:
Mar. 30, 1990
Hirozo Segawa, Kitakanbara, JP;
Norio Ishikawa, Takaishi, JP;
Katsuji Yoguchi, Takaishi, JP;
Morimasa Kuragano, Sakai, JP;
Minoru Koshibe, Sakai, JP;
Mitsui Toatsu Chemicals, Inc., Tokyo, JP;
Kuraray Company, Ltd., Kurashiki, JP;
Abstract
A purification process for methyl methacrylate (MMA) and a recovery process for methanol are disclosed. A mixture, which contains water, methanol and methyl methacrylate (MMA) as principal components along with at least one of methyl acrylate, methyl propionate and methacrylic acid, is azeotropically distilled together with hexane to obtain MMA in a form substantially free of water, methanol methyl acrylate, methyl propionate and hexane and a low boiling-point fraction. The low boiling-point fraction is cooled and separated into a water phase and an oil phase. Methanol can be recovered from the water phase by adding an alkaline substance to it and then distilling the resultant mixture. A preparation process of MMA is also disclosed. MMA can be prepared by esterifying methacrylic acid or methacrylamide with methanol and then applying the above purification process.