Granted Patent
Utility
US 5,449,658 · App. 08/163,448
Biocidal compositions comprising polyhexamethylene biguanide and EDTA, and methods for treating commercial and recreational water
Inventors:
Michael J. Unhoch, Peter S. K. Lee, David G. Chasin
Patented Case
View Patent ↗
Granted: Sep 12, 1995
Filed: Dec 7, 1993
Inventors
Michael J. Unhoch
Peter S. K. Lee
David G. Chasin
Assignee (at issue)
Zeneca Limited
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.