Granted Patent
Utility
US 4,612,389 · App. 06/376,933
Treatment of waste stream from pentaerythritol manufacture
Inventors:
Frank Gupton, Harry E. Ulmer
Patented Case
View Patent ↗
Granted: Sep 16, 1986
Filed: May 10, 1982
Inventors
Frank Gupton
Harry E. Ulmer
Assignee (at issue)
Virginia Chemicals Inc.
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.