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:
Feb. 23, 2016
Filed:
Jul. 11, 2013
Rhodia Operations, Paris, FR;
Pierre Marcel Ardaud, Ste Foy les Lyon, FR;
Rabih Julien Rached, Millery, FR;
Thierry Alban Marcel Vidal, Lyons, FR;
Rhodia Operations, Paris, FR;
Abstract
The present invention relates to a process for preparing an anhydride of formula A-C(═O)—O—(O═)C-A, where A is —CR═CH2 and R is —H or —CH3, comprising: a) a step of reacting an anhydride B—C(═O)—O—(O═)C—B with an acid A-COOH, A being as defined above, wherein the step results in the formation of an anhydride A-C(═O)—O—(O═)C—B and of an acid B—COOH, A and B being such that said acid B—COOH is more volatile than said acid A-COOH, and b) a step of reacting said anhydride A-C(═O)—O—(O═)C—B with the acid A-COOH under conditions such that the amount of acid B—COOH is less than the amount of acid A-COOH, resulting in the formation of the anhydride A-C(═O)—O—(O═)C-A, in which said reaction steps are carried out in the presence of an acid catalyst which is more volatile than said anhydride A-C(═O)—O—(O═)C-A.