Granted Patent
Utility
US 4,153,680 · App. 05/852,758
Hydrous silica gel containing dentifrice
Inventor:
Earl K. Seybert
Patented Case
View Patent ↗
Granted: May 8, 1979
Filed: Nov 18, 1977
Inventor
Earl K. Seybert
Assignee (at issue)
W. R. Grace & Co.
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.