Granted Patent
Utility
US 4,778,634 · App. 07/110,916
Process for the manufacture of porous film
Inventor:
Noel L. Douglas
Patented Case
View Patent ↗
Granted: Oct 18, 1988
Filed: Oct 21, 1987
Inventor
Noel L. Douglas
Assignee (at issue)
El Paso Products Company
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.