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:
Apr. 23, 1996
Filed:
Jan. 27, 1994
Michel Fauconet, Valmont, FR;
Norbert Richard, Creutz Wald, FR;
Marc Esch, Frey Ming - Merlebach, FR;
Nadine Colin, Saint-Avold, FR;
Elf Atochem S.A., Puteaux, FR;
Abstract
An alkyl (meth)acrylate is prepared by a direct esterification (in 1) of (meth)acrylic acid by the corresponding alcohol, catalysed by H.sub.2 SO.sub.4. To the crude reaction mixture (C.sub.1) comprising the desired ester, alcohol, (meth)acrylic acid, alkyl hydrogen sulphate and traces of H.sub.2 SO.sub.4, there is added (in 3) a base to neutralize the acidic species, the resulting salts passing into the aqueous phase (A.sub.1), which is separated from the organic phase (O.sub.1) containing the desired ester. The light products (L.sub.1) containing the alcohol are recovered (in 4) from the aqueous phase, and the waste waters (W.sub.2) are expelled. A hydrolysis is carried out (in 8) of the alkyl hydrogen sulphate present in the aqueous phase (A.sub.1) obtained after the separation which is carried out after neutralization (in 3), to form the alcohol and H.sub.2 SO.sub.4 in this phase, the acidic species resulting from the hydrolysis are neutralized by introduction of a base .into the medium, and the resulting aqueous phase (A.sub.3) is directed to the step for recovery of the alcohol. Pollution of the waters (W.sub.2), attributable to the alkyl hydrogen sulphate, is thus avoided.