Granted Patent
Utility
US 5,137,983 · App. 07/551,597
Surface-modified polyacrylonitrile beads
Inventors:
Laurence W. Chang, Larry S. Anderson, David A. Ley
Patented Case
View Patent ↗
Granted: Aug 11, 1992
Filed: Jul 11, 1990
Inventors
Laurence W. Chang
Larry S. Anderson
David A. Ley
Assignee (at issue)
American Cyanamid Company
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.