Granted Patent
Utility
US 4,207,142 · App. 05/917,777
Paper sizing agents
Inventor:
David Shepherd
Patented Case
View Patent ↗
Granted: Jun 10, 1980
Filed: Jun 21, 1978
Inventor
David Shepherd
Assignee (at issue)
Tenneco Chemicals, 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.