Granted Patent
Utility
US 4,426,313 · App. 06/435,135
Preparation of surfactants by sulfonating derivatives of depolymerized coal
Inventor:
Raymond J. Swedo
Patented Case
View Patent ↗
Granted: Jan 17, 1984
Filed: Oct 18, 1982
Inventor
Raymond J. Swedo
Assignee (at issue)
UOP LLC
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.