Granted Patent
Utility
US 4,203,923 · App. 05/667,760
Method for promotion of phenol hydrogenation
Inventors:
Chuen Y. Yeh, Harry E. Ulmer
Patented Case
View Patent ↗
Granted: May 20, 1980
Filed: Mar 17, 1976
Inventors
Chuen Y. Yeh
Harry E. Ulmer
Assignee (at issue)
Allied Chemical Corporation
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.