Granted Patent
Utility
US 4,740,291 · App. 06/684,139
Upgrading of pyrolysis tar using acidic catalysts
Inventors:
Rostislav Didchenko, Eric M. Dickinson
Patented Case
View Patent ↗
Granted: Apr 26, 1988
Filed: Dec 20, 1984
Inventors
Rostislav Didchenko
Eric M. Dickinson
Assignee (at issue)
Union Carbide 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.