Granted Patent
Utility
US 4,404,239 · App. 06/404,243
Treatment of wood with water repellent compositions
Inventor:
John F. Grunewalder
Patented Case
View Patent ↗
Granted: Sep 13, 1983
Filed: Aug 2, 1982
Inventor
John F. Grunewalder
Assignee (at issue)
PPG 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.