Granted Patent
Utility
US 4,975,259 · App. 07/382,788
Method of liquefying and condensing nitrogen trifluoride and a method of purifying nitrogen trifluoride
Inventors:
Hiroyuki Hyakutake, Isao Harada, Naruyuki Iwanaga, Toshihiko Nishitsuji
Patented Case
View Patent ↗
Granted: Dec 4, 1990
Filed: Jun 26, 1989
Inventors
Hiroyuki Hyakutake
Isao Harada
Naruyuki Iwanaga
Toshihiko Nishitsuji
Assignee (at issue)
Mitsui Toatsu Chemicals, Incorporated
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.