Granted Patent
Utility
US 4,444,928 · App. 06/405,114
Polymeric malonic acid derivatives
Inventor:
Friedrich Karrer
Patented Case
View Patent ↗
Granted: Apr 24, 1984
Filed: Aug 4, 1982
Inventor
Friedrich Karrer
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.