Granted Patent
Utility
US 4,904,713 · App. 07/293,532
Bituminous composition
Inventors:
Willem C. Vonk, Hendrik-Jan Brouwer, Anthony L. Bull
Patented Case
View Patent ↗
Granted: Feb 27, 1990
Filed: Dec 30, 1988
Inventors
Willem C. Vonk
Hendrik-Jan Brouwer
Anthony L. Bull
Assignee (at issue)
SHELL OIL 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.