Granted Patent
Utility
US 4,277,620 · App. 06/126,174
Byproduct recovery from a pentaerythritol waste stream
Inventors:
B. Frank Gupton, Harry E. Ulmer
Patented Case
View Patent ↗
Granted: Jul 7, 1981
Filed: Feb 29, 1980
Inventors
B. 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.