Granted Patent
Utility
US 5,494,607 · App. 08/235,050
Alkyl substituted phenol-polyethylenepolyamine-formaldehyde resins as asphaltene dispersants
Inventors:
Maria B. Manek, Kailash Sawhney
Patented Case
View Patent ↗
Granted: Feb 27, 1996
Filed: Apr 29, 1994
Inventors
Maria B. Manek
Kailash Sawhney
Assignee (at issue)
Nalco Chemical 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.