Granted Patent
Utility
US 5,264,539 · App. 07/866,160
Thermally stable oligomeric ultraviolet stabilizers
Inventor:
James P. Shepherd
Patented Case
View Patent ↗
Granted: Nov 23, 1993
Filed: Apr 9, 1992
Inventor
James P. Shepherd
Assignee (at issue)
Hoechst Celanese 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.