Granted Patent
Utility
US 6,558,591 · App. 09/729,209
Process of making microporous film
Inventor:
Gijsbertus Hendrikus Maria Calis
Patented Case
View Patent ↗
Granted: May 6, 2003
Filed: Dec 5, 2000
Inventor
Gijsbertus Hendrikus Maria Calis
Assignee (at issue)
DSM N.V.
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.