Granted Patent
Utility
US 4,861,914 · App. 07/048,261
Discoloration inhibitors for aromatic amines
Inventor:
Charles F. Weidig
Patented Case
View Patent ↗
Granted: Aug 29, 1989
Filed: May 11, 1987
Inventor
Charles F. Weidig
Assignee (at issue)
Ethyl 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.