Granted Patent
Utility
US 4,645,538 · App. 06/739,978
Asphaltic compositions
Inventors:
William E. Wright, Edward F. Zaweski
Patented Case
View Patent ↗
Granted: Feb 24, 1987
Filed: May 31, 1985
Inventors
William E. Wright
Edward F. Zaweski
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.