Granted Patent
Utility
US 4,549,973 · App. 06/488,159
Decolorization of calcium bromide brines
Inventor:
Warren B. Kirsch
Patented Case
View Patent ↗
Granted: Oct 29, 1985
Filed: Apr 25, 1983
Inventor
Warren B. Kirsch
Assignee (at issue)
Ethyl 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.