Granted Patent
Utility
US 5,981,681 · App. 09/098,363
Silicone aminopolyalkyleneoxide block copolymers
Inventor:
Anna Czech
Patented Case
View Patent ↗
Granted: Nov 9, 1999
Filed: Jun 17, 1998
Inventor
Anna Czech
Assignee (at issue)
Witco Corporation
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.