Granted Patent
Utility
US 5,120,521 · App. 07/637,833
Method of producing colored precipitated calcium carbonate
Inventors:
Osamu Ebinuma, Takashi Sakaguchi, Akira Yokoi, Yoshiki Saitoh
Patented Case
View Patent ↗
Granted: Jun 9, 1992
Filed: Jan 7, 1991
Inventors
Osamu Ebinuma
Takashi Sakaguchi
Akira Yokoi
Yoshiki Saitoh
Assignee (at issue)
Oji Paper Co., Ltd.
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.