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:
Jun. 17, 2003
Filed:
Jul. 07, 2000
Roland Kotwica, Pontpoint, FR;
André Marbach, Verneuil en Halatte, FR;
Elf Atochem, S.A., Puteau, FR;
Abstract
For the purification of the norbornene obtained by the reaction of dicyclopentadiene or cyclopentadiene and ethylene, the crude reaction mixture containing light impurities having boiling temperatures lower than that of norbornene; medium-heavy impurities having the boiling temperatures between that of norbornene and that of ethylnorbornene; and heavy impurities containing ethylnorbornene and compounds boiling higher than ethylnorbornene, boiling temperatures greater than that ethylnorbornene, a first distillation of the crude reaction mixture is carried out in a tailing column (C ), removing a portion of the heavy impurities and a portion of the medium-heavy impurities; then a second distillation of the crude mixture, thus tailed, is carried out in a topping column (C ), removing the light impurities; and a third distillation of the mixture, thus topped, is subsequently carried out in a tailing column (C ), removing the remainder of the heavy and medium-heavy impurities.