Granted Patent
Utility
US 5,194,561 · App. 07/563,498
Process for the preparation of an aromatic polyether in the presence of finely divided condensation auxiliaries
Inventors:
Hartmut Fischer, Arnold Schneller
Patented Case
View Patent ↗
Granted: Mar 16, 1993
Filed: Aug 7, 1990
Inventors
Hartmut Fischer
Arnold Schneller
Assignee (at issue)
Hoechst 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.