Granted Patent
Utility
US 6,790,553 · App. 09/889,971
Method for producing bridged polymer membrane and fuel cell
Inventor:
Tetsu Yamamoto
Patented Case
View Patent ↗
Granted: Sep 14, 2004
Filed: Sep 6, 2001
Inventor
Tetsu Yamamoto
Assignee (at issue)
Celanese Ventures GmbH
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.