Granted Patent
Utility
US 5,605,569 · App. 08/555,552
Precipitated silica having high sodium sulfate content
Inventors:
James L. Boyer, Thomas G. Krivak, Harold E. Swift, Robert C. Wang
Patented Case
View Patent ↗
Granted: Feb 25, 1997
Filed: Nov 8, 1995
Inventors
James L. Boyer
Thomas G. Krivak
Harold E. Swift
Robert C. Wang
Assignee (at issue)
PPG Industries, Inc.
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.