Granted Patent
Utility
US 6,238,542 · App. 09/394,839
Water soluble brighteners for zinc and zinc alloy electrolytes
Inventor:
Thomas Helden
Patented Case
View Patent ↗
Granted: May 29, 2001
Filed: Sep 13, 1999
Inventor
Thomas Helden
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.