Granted Patent
Utility
US 4,714,481 · App. 06/530,598
Gas separation membrane
Inventors:
Junichi Matsuura, Munehisa Okada
Patented Case
View Patent ↗
Granted: Dec 22, 1987
Filed: Jul 20, 1983
Inventors
Junichi Matsuura
Munehisa Okada
Assignee (at issue)
Mitsubishi Chemical Industries, Ltd.
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.