Granted Patent
Utility
US 4,542,191 · App. 06/312,197
Rubber additives derived from guayule resins and compositions containing them
Inventors:
Edward L. Kay, Richard Gutierrez
Patented Case
View Patent ↗
Granted: Sep 17, 1985
Filed: Oct 19, 1981
Inventors
Edward L. Kay
Richard Gutierrez
Assignee (at issue)
The Firestone Tire & Rubber Company
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.