Granted Patent
Utility
US 4,457,874 · App. 06/396,698
Condensation products of substituted phenol sulfonic acid and formaldehyde
Inventors:
John G. Papalos, Arpad Savoly
Patented Case
View Patent ↗
Granted: Jul 3, 1984
Filed: Jul 9, 1982
Inventors
John G. Papalos
Arpad Savoly
Assignee (at issue)
Diamond Shamrock Chemicals Company
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.