Granted Patent
Utility
US 4,394,273 · App. 06/329,350
Defoamers for aqueous liquids containing soluble zinc salts
Inventor:
Michael H. Hoff
Patented Case
View Patent ↗
Granted: Jul 19, 1983
Filed: Dec 10, 1981
Inventor
Michael H. Hoff
Assignee (at issue)
NL Industries, Inc.
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.