Granted Patent
Utility
US 5,521,052 · App. 08/365,659
Metal ion reduction in novolak resin using an ion exchange catalyst in a polar solvent and photoresists compositions therefrom
Inventors:
M. Dalil Rahman, Daniel P. Aubin, Dinesh N. Khanna, Douglas McKenzie
Patented Case
View Patent ↗
Granted: May 28, 1996
Filed: Dec 30, 1994
Inventors
M. Dalil Rahman
Daniel P. Aubin
Dinesh N. Khanna
Douglas McKenzie
Assignee (at issue)
Hoechst Celanese Corporation
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.