Granted Patent
Utility
US 4,929,707 · App. 07/305,905
Polyurethane base lens resin, plastic lens comprising the resin and preparation method of the lens
Inventors:
Teruyuki Nagata, Koju Okazaki, Nobuyuki Kajimoto, Tohru Miura, Yoshinobu Kanemura, Katsuyoshi Sasagawa
Patented Case
View Patent ↗
Granted: May 29, 1990
Filed: Feb 3, 1989
Inventors
Teruyuki Nagata
Koju Okazaki
Nobuyuki Kajimoto
Tohru Miura
Yoshinobu Kanemura
Katsuyoshi Sasagawa
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.