Granted Patent
Utility
US 4,231,986 · App. 06/027,819
Grease compatible mineral oil extended polyurethane
Inventors:
Melvin Brauer, Thaddeus F. Kroplinski
Patented Case
View Patent ↗
Granted: Nov 4, 1980
Filed: Apr 6, 1979
Inventors
Melvin Brauer
Thaddeus F. Kroplinski
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.