Granted Patent
Utility
US 4,957,908 · App. 07/461,720
Chitosan pyrithione as antimicrobial agent useful in personal care products
Inventor:
John D. Nelson
Patented Case
View Patent ↗
Granted: Sep 18, 1990
Filed: Jan 8, 1990
Inventor
John D. Nelson
Assignee (at issue)
Olin Corporation
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.