Granted Patent
Utility
US 4,997,605 · App. 07/425,911
Zirconia mullite/boron nitride composites
Inventor:
Gregory W. Shaffer
Patented Case
View Patent ↗
Granted: Mar 5, 1991
Filed: Oct 24, 1989
Inventor
Gregory W. Shaffer
Assignee (at issue)
Union Carbide 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.