Granted Patent
Utility
US 5,891,326 · App. 08/986,593
Process for removing impurities from kaolin clays
Inventors:
Joseph C. S. Shi, Jorge L. Yordan
Patented Case
View Patent ↗
Granted: Apr 6, 1999
Filed: Dec 8, 1997
Inventors
Joseph C. S. Shi
Jorge L. Yordan
Assignee (at issue)
Thiele Kaolin 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.