Granted Patent
Utility
US 4,539,428 · App. 06/376,478
Preparation of diaminodiphenyl ethers
Inventors:
Philip H. Merrell, Michael Ellis
Patented Case
View Patent ↗
Granted: Sep 3, 1985
Filed: May 10, 1982
Inventors
Philip H. Merrell
Michael Ellis
Assignee (at issue)
MALLINCKRODT 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.