Granted Patent
Utility
US 4,659,642 · App. 06/663,607
Positive working naphthoquinone diazide color proofing transfer process
Inventors:
Stephan J. W. Platzer, Gabor I. Koletar, Richard L. Shadrach
Patented Case
View Patent ↗
Granted: Apr 21, 1987
Filed: Oct 22, 1984
Inventors
Stephan J. W. Platzer
Gabor I. Koletar
Richard L. Shadrach
Assignee (at issue)
American Hoechst 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.