Granted Patent
Utility
US 4,470,900 · App. 06/148,876
Solids precipitation and polymerization of asphaltenes in coal-derived liquids
Inventor:
Paul H. Kydd
Patented Case
View Patent ↗
Granted: Sep 11, 1984
Filed: May 12, 1980
Inventor
Paul H. Kydd
Assignee (at issue)
HRI
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.