Granted Patent
Utility
US 4,358,321 · App. 06/272,084
Lead-free ceramic pink-coloring material consisting of chromium-tin-calcium-silicon-alkali metal oxide plus bismuth and/or phosphorus oxide and process
Inventors:
Robert Fischer, Heinz-Dieter DeAhna
Patented Case
View Patent ↗
Granted: Nov 9, 1982
Filed: Jun 10, 1981
Inventors
Robert Fischer
Heinz-Dieter DeAhna
Assignee (at issue)
Degussa AG
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.