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:
Aug. 19, 1997
Filed:
Jun. 19, 1995
Jacqueline Bessalem, Saint-Avold, FR;
Michel Fauconet, Valmont, FR;
Christian Lacroix, Folkling, FR;
Nathalie Hess, Saint-Avold, FR;
Elf Atochem S.A., Puteaux, FR;
Abstract
An acrylic acid ester is manufactured by reaction of the said acid and an alcohol chosen from C.sub.5 or above primary and secondary aliphatic monoalcohols, in the presence of an acid as esterification catalyst and of a polymerization inhibitor, the alcohol being capable of forming a heteroazeotrope with water, the water formed by the esterification reaction being entrained by distillation in a column in the form of a heteroazeotropic mixture with the alcohol, which mixture, containing an amount of unreacted acrylic acid, is then subjected, after condensation, to a separation in order to give an upper organic phase which is recycled to the head of the distillation column and a lower aqueous phase which is withdrawn; according to the invention, an extraction (for example in an extraction column EC) of the acrylic acid contained in the condensed heteroazeotropic mixture (M) intended for phase separation with an esterifying-alcohol-rich mixture, and the acrylic acid thus extracted is returned to the head of the distillation column (DC), as a constituent of the recycled organic phase, with an increase in the level of reflux into the distillation column (DC) relative to the natural reflux.