Granted Patent
Utility
US 4,529,665 · App. 06/565,249
Ammonium salts of sulfocarboxylic acid esters as acid catalysts
Inventors:
Suryya K. Das, Samuel Porter, Jr., William P. Blackburn, Karl F. Schimmel, Rostyslaw Dowbenko
Patented Case
View Patent ↗
Granted: Jul 16, 1985
Filed: Dec 23, 1983
Inventors
Suryya K. Das
Samuel Porter, Jr.
William P. Blackburn
Karl F. Schimmel
Rostyslaw Dowbenko
Assignee (at issue)
PPG Industries, 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.