Granted Patent
Utility
US 4,904,773 · App. 07/023,619
Process for extracting methylxanthines from aqueous solutions containing same
Inventors:
Ernest K. C. Yu, Wayne R. Bellamy, Alexander Michael Sills
Patented Case
View Patent ↗
Granted: Feb 27, 1990
Filed: Mar 9, 1987
Inventors
Ernest K. C. Yu
Wayne R. Bellamy
Alexander Michael Sills
Assignee (at issue)
Allelix 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.