Granted Patent
Utility
US 4,614,762 · App. 06/620,977
Water soluble linear polyethyleneimine derivative from water-insoluble polyethyleneimine, polyvinyl alcohol and aldehyde
Inventors:
Nelson S. Marans, Stephen M. Pulford
Patented Case
View Patent ↗
Granted: Sep 30, 1986
Filed: Jun 15, 1984
Inventors
Nelson S. Marans
Stephen M. Pulford
Assignee (at issue)
W. R. Grace & Co.
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.