Granted Patent
Utility
US 4,250,079 · App. 06/037,600
Process for the manufacture of a perylene-3,4,9,10-tetracarboxylic dianhydride pigment with improved properties
Inventor:
Fridolin Babler
Patented Case
View Patent ↗
Granted: Feb 10, 1981
Filed: May 10, 1979
Inventor
Fridolin Babler
Assignee (at issue)
Ciba-Geigy
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.