Granted Patent
Utility
US 4,985,078 · App. 07/357,999
Thermostable zinc ferrite color pigments containing 0.05-0.5 wt % lithium, a process for their preparation and their use
Inventors:
Jakob Rademachers, Volker Wilhelm, Siegfried Keifer, Wilfried Burow
Patented Case
View Patent ↗
Granted: Jan 15, 1991
Filed: May 30, 1989
Inventors
Jakob Rademachers
Volker Wilhelm
Siegfried Keifer
Wilfried Burow
Assignee (at issue)
Bayer Aktiengesellschaft
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.