Granted Patent
Utility
US 5,146,041 · App. 07/753,502
Method of separating isobutylene from a C-4 hydrocarbon fraction using montmorillonite catalysts
Inventor:
John F. Knifton
Patented Case
View Patent ↗
Granted: Sep 8, 1992
Filed: Sep 3, 1991
Inventor
John F. Knifton
Assignee (at issue)
Texaco Chemical 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.