Granted Patent
Utility
US 4,480,140 · App. 06/475,719
Process for alkylating phenolic compounds to produce ortho or para-monoalkylated or 2,4- or 2,6-dialkylated phenols
Inventor:
Gerd Leston
Patented Case
View Patent ↗
Granted: Oct 30, 1984
Filed: Mar 16, 1983
Inventor
Gerd Leston
Assignee (at issue)
KOPPERS, 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.