Granted Patent
Utility
US 5,837,797 · App. 08/753,436
Process for preparing a sulfur-containing urethane-based plastic lens and the lens prepared thereby
Inventors:
Koju Okazaki, Yoshinobu Kanemura, Teruyuki Nagata
Patented Case
View Patent ↗
Granted: Nov 17, 1998
Filed: Nov 25, 1996
Inventors
Koju Okazaki
Yoshinobu Kanemura
Teruyuki Nagata
Assignee (at issue)
Mitsui Toatsu Chemicals, Incorporated
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.