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. 01, 2002
Filed:
Nov. 09, 1998
Applicant:
Inventors:
Ralph Newton Miller, Newark, DE (US);
Chien-Ping Chai Kao, Newark, DE (US);
Barry Asher Mahler, Glen Mills, PA (US);
Assignee:
E. I. du Pont de Nemours and Company, Wilmington, DE (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B01D 3/34 ; C01B 2/104 ; C07C 1/7386 ;
U.S. Cl.
CPC ...
B01D 3/34 ; C01B 2/104 ; C07C 1/7386 ;
Abstract
Nitrogen trifluoride (NF ) containing less than 10 parts-per-million molar impurities, e.g., tetrafluoromethane (PFC-14), is disclosed. Azeotropic and extractive distillation processes using entraining agents for separating NF and PFC-14 from each other and from mixtures with other electronics industry materials are disclosed.