Granted Patent
Utility
US 4,820,740 · App. 06/925,779
Process and catalyst for production of bisphenol-A
Inventor:
Simon M. Li
Patented Case
View Patent ↗
Granted: Apr 11, 1989
Filed: Oct 30, 1986
Inventor
Simon M. Li
Assignee (at issue)
SHELL OIL 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.