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. 06, 1998
Filed:
Jun. 03, 1997
Ralph Newton Miller, Newark, DE (US);
V N Rao, Wilmington, DE (US);
Allen Capron Sievert, Elkton, MD (US);
E. I. du Pont de Nemours and Company, Wilmington, DE (US);
Abstract
A process is disclosed for producing 1,12,2,3,3,4,4-octafluorobutane. The process involves chlorination of 2,2,3,3-tetrafluorobutane to form a mixture of chloro-compounds wherein compounds of the formula C.sub.4 H.sub.4 Cl.sub.6-x F.sub.4 (where x is 0 or 1) comprise at least 50 mole % of the mixture of chloro-compounds, followed by hydrofluorination, then hydrogenolysis, and sufficient recycle to provide a selectivity to CHF.sub.2 CF.sub.2 CF.sub.2 CHF.sub.2 of at least about 75% based upon the moles of CH.sub.3 CF.sub.2 CF.sub.2 CH.sub.3 reacted. Also disclosed is a multi-distillation process for the purification of CHF.sub.2 CF.sub.2 CF.sub.2 CHF.sub.2 from a mixture of HF and the compound(s). Also disclosed are certain new halogenated butanes containing fluorine, and a composition which contains HF in combination with an effective amount of CHF.sub.2 CF.sub.2 CF.sub.2 CHF.sub.2 to form an azeotrope or azeotrope-like composition with hydrogen fluoride.