Granted Patent
Utility
US 4,677,186 · App. 06/895,603
Polyimides and a process for their preparation
Inventor:
Josef Pfeifer
Patented Case
View Patent ↗
Granted: Jun 30, 1987
Filed: Aug 7, 1986
Inventor
Josef Pfeifer
Assignee (at issue)
Ciba-Geigy
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.