Granted Patent
Utility
US 4,266,987 · App. 05/790,498
Process for providing acid-resistant oxide layers on alloys
Inventor:
Chih-Chung Wang
Patented Case
View Patent ↗
Granted: May 12, 1981
Filed: Apr 25, 1977
Inventor
Chih-Chung Wang
Assignee (at issue)
Kennecott Copper 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.