Granted Patent
Utility
US 4,550,213 · App. 06/625,942
Method of manufacture for paraformaldehyde prills
Inventors:
Hubert H. Thigpen, Richard Clos
Patented Case
View Patent ↗
Granted: Oct 29, 1985
Filed: Jun 29, 1984
Inventors
Hubert H. Thigpen
Richard Clos
Assignee (at issue)
Celanese GmbH
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.