Granted Patent
Utility
US 5,879,441 · App. 08/530,627
Very highly transparent yellow iron oxide pigments, a process for their production and their use
Inventor:
Ulrike Pitzer
Patented Case
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Granted: Mar 9, 1999
Filed: Sep 20, 1995
Inventor
Ulrike Pitzer
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.