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. 12, 1990
Filed:
Oct. 24, 1989
Makoto Aritsuka, Yamaguchi, JP;
Naruyuki Iwanaga, Yamaguchi, JP;
Mitsui Toatsu Chemicals, Incorporated, Tokyo, JP;
Abstract
There is here disclosed a method for removing nitrous oxide (N.sub.2 O), carbon dioxide (CO.sub.2) and dinitrogen difluoride (N.sub.2 F.sub.2) from a nitrogen trifluoride gas. The present invention is directed to a method for purifying a nitrogen trifluoride gas which comprises the steps of thermally treating, at a temperature of 250.degree. to 700.degree. C., a zeolite selected from the group consisting of analcime, clinoptilolite, mordenite, ferrierite, phillipsite, chabazite, erionite and laumotite; forming a packed bed of the treated zeolite; and passing the nitrogen trifluoride gas containing the gaseous impurities at a temperature of -125.degree. to 50.degree. C. through the filler layer.