Granted Patent
Utility
US 5,331,068 · App. 08/109,415
Adducts of diaminodiphenyl sulfone compounds as hardeners for epoxy resins
Inventor:
Yefim Blyakhman
Patented Case
View Patent ↗
Granted: Jul 19, 1994
Filed: Aug 19, 1993
Inventor
Yefim Blyakhman
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.