Granted Patent
Utility
US 4,061,724 · App. 05/615,557
Crystalline silica
Inventors:
Robert W. Grose, Edith M. Flanigen
Patented Case
View Patent ↗
Granted: Dec 6, 1977
Filed: Sep 22, 1975
Inventors
Robert W. Grose
Edith M. Flanigen
Assignee (at issue)
Union Carbide 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.