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:
May. 15, 2018
Filed:
Jan. 20, 2015
Rhodia Operations, Paris, FR;
Rhodia Operations, Paris, FR;
Abstract
The invention relates to a method for producing a (meth)acrylic anhydride A-C(═O)—O—(O═)C-A, comprising the following steps: a) a step of reacting an anhydride B—C(═O)—O—(O═)C—B with an acid A-COOH, resulting in the formation of mixed anhydride A-C(═O)—O—(O═)C—B and acid B—COOH; and b) a step of reacting the mixed anhydride with A-COOH, resulting in the (meth)acrylic anhydride. According to the invention, reaction steps (a) and (b) are carried out in the presence of hydrated triflic acid, and the anhydride A-C(═O)—O—(O═)C-A is isolated from the reaction medium produced in step (b) as follows: e1) heavy compounds having a volatility less than or equal to that of the anhydride A-C(═O)—O—(O═)C-A are separated from the reaction medium, said compounds including the anhydride and the hydrated triflic acid; e2) the anhydride is separated from the heavy compounds by difference in volatility.