Granted Patent
Utility
US 4,909,810 · App. 07/301,826
Vapor permselective membrane
Inventors:
Makoto Nakao, Yoshio Sugaya, Hiroshi Mori, Hirofumi Horie, Hirokazu Wakabayashi
Patented Case
View Patent ↗
Granted: Mar 20, 1990
Filed: Jan 26, 1989
Inventors
Makoto Nakao
Yoshio Sugaya
Hiroshi Mori
Hirofumi Horie
Hirokazu Wakabayashi
Assignee (at issue)
ASAHI GLASS CO., 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.