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:
Nov. 08, 1994
Filed:
Jul. 06, 1993
Hiroyuki Niijima, Himeji, JP;
Kazuyuki Akita, Himeji, JP;
Daicel Chemical Industries, Ltd., Sakai, JP;
Abstract
Acetic acid and/or acetic anhydride containing methyl crotonate, vinyl acetate, or both as impurities, is contacted with ozone in an amount of excess molar to the carbon-carbon double bond in said methyl crotonate and/or vinyl acetate and the impurities produced by ozone-treatment are removed off by distillation. A large quantity of impurities such as aldehydes are produced after treatment by treating acetic acid and/or acetic anhydride containing much amount of unsaturated compounds as impurities with ozone. Distilling the ozone-treated acetic acid and/or acetic anhydride make it possible to remove methyl crotonate and vinyl acetate, which are unsaturated compounds difficult to remove by the conventional separation methods, to give high-quality acetic acid and/or acetic anhydride excellent in the residence time in the potassium permanganate test.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile