Granted Patent
Utility
US 4,303,549 · App. 06/135,478
Liquid defoamer and defoaming process
Inventor:
Francis J. Boylan
Patented Case
View Patent ↗
Granted: Dec 1, 1981
Filed: Mar 31, 1980
Inventor
Francis J. Boylan
Assignee (at issue)
Drew Chemical 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.