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. 06, 1993
Filed:
Sep. 13, 1991
Mitsubishi Gas Chemical Company, Inc., Tokyo, JP;
Abstract
A process for producing methacrylic acid which comprises: (I) producing acetonecyanohydrin from prussic acid and acetone; (II) hydrating the acetonecyanohydrin obtained in step (I) to form .alpha.-hydroxyisobutyric acid amide; (III) reacting the .alpha.-hydroxyisobutyric acid amide obtained in step (II) with methyl formate or with methanol and carbon monoxide to form methyl .alpha.-hydroxyisobutyrate and formamide; (IV) hydrolyzing the methyl .alpha.-hydroxyisobutyrate obtained in step (III) to form .alpha.-hydroxyisobutyric acid; (V) dehydrating the .alpha.-hydroxyisobutyric acid obtained in step (IV) to form methacrylic acid; and (VI) dehydrating the formamide separated from the products obtained in step (III) to form prussic acid and recycling the prussic acid to step (I) as a starting material. The process is capable of producing methacrylic acid from readily available starting materials with a high yield and selectivity, without forming undesirable by-product or waste materials, such as ammonium sulfate.