Granted Patent
Utility
US 4,886,866 · App. 07/312,331
Contact lenses based on biocompatible polyurethane and polyurea-urethane hydrated polymers
Inventors:
James A. Braatz, Clifton L. Kehr
Patented Case
View Patent ↗
Granted: Dec 12, 1989
Filed: Feb 16, 1989
Inventors
James A. Braatz
Clifton L. Kehr
Assignee (at issue)
W.R. Grace & Co. Conn.
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.