Granted Patent
Utility
US 4,997,599 · App. 07/394,348
Preparation of water soluble cellulose acetate microspheres
Inventors:
Thomas L. Steiner, Dana T. Minnick, Kenneth A. Domeshek, Donald H. Lester, Jr.
Patented Case
View Patent ↗
Granted: Mar 5, 1991
Filed: Aug 15, 1989
Inventors
Thomas L. Steiner
Dana T. Minnick
Kenneth A. Domeshek
Donald H. Lester, Jr.
Assignee (at issue)
Celanese Fibers, 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.