Granted Patent
Utility
US 4,492,749 · App. 06/532,302
Diazotype materials with 2-hydroxy-naphthalene having sulfonamide substituent as coupler
Inventor:
Siegfried Scheler
Patented Case
View Patent ↗
Granted: Jan 8, 1985
Filed: Sep 15, 1983
Inventor
Siegfried Scheler
Assignee (at issue)
Hoechst GmbH
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.