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:
Oct. 27, 1998
Filed:
Dec. 22, 1993
Eric Paumard, Cappel, FR;
Atochem, Paris, FR;
Abstract
Use of at least one heteropolyacid H.sub.n A.sub.a D.sub.c O.sub.y.xH.sub.2 O where A is phosphorus, boron, silicon, germanium, tin, arsenic, antimony, copper, nickel, cobalt, iron, cerium, thorium, chromium and mixtures thereof; D is molybdenum, tungsten, vanadium and combinations thereof; a is 0.1-10; c is 6-18; n is the number of acidic hydrogens in the heteropolyacid and is a number above 1; y is the number of oxygens in the heteropolyacid and is a number of 10-70; and x is the number of moles of water of crystal-lisation and is a number of 0-40, as catalyst in the preparation of esters of unsaturated carboxylic acids by direct esterification of acids with alcohols or by transesterification, these reactions being carried out in the liquid phase.