Granted Patent
Utility
US 5,230,833 · App. 07/932,284
Low sodium, low metals silica polishing slurries
Inventors:
John A. Romberger, Charles C. Payne
Patented Case
View Patent ↗
Granted: Jul 27, 1993
Filed: Aug 19, 1992
Inventors
John A. Romberger
Charles C. Payne
Assignee (at issue)
Nalco Chemical Company
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.