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. 11, 2010
Filed:
Mar. 14, 2007
Dirk Broell, Langen, DE;
Hermann Siegert, Seeheim-Jugenheim, DE;
Dirk Broell, Langen, DE;
Hermann Siegert, Seeheim-Jugenheim, DE;
Evonik Roehm GmbH, Darmstadt, DE;
Abstract
The invention relates to a method for the continuous production of unsaturated carboxylic acid anhydrides of general formula (I): R—C(O)—O—C(O)—R (I), wherein R is an unsaturated organic group with 2 to 12 C atoms, by reaction of a ketene with an unsaturated carboxylic acid of general formula (II): R—COOH (II), wherein R is defined as above, in an apparatus which has a reaction zone () for the reaction of a ketene with an unsaturated carboxylic acid of general formula (II), and a reaction zone () for the subsequent reaction of the crude anhydride mixture and a rectification column with an upper, a middle and a lower zone, in the sump of which an inert boiling oil is present.