Granted Patent
Utility
US 5,239,053 · App. 07/834,968
Purification of vinyl lactam polymers
Inventors:
Susan Y. Tseng, William L. Mandella, Terry E. Smith, Robert B. Login, Paul D. Taylor
Patented Case
View Patent ↗
Granted: Aug 24, 1993
Filed: Feb 14, 1992
Inventors
Susan Y. Tseng
William L. Mandella
Terry E. Smith
Robert B. Login
Paul D. Taylor
Assignee (at issue)
ISP INVESTMENTS LLC
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.