Polyvinyl alcohol derivatives containing pendant (meth)acryloyl units bound through urethane groups and crosslinked hydrogel contact lenses made therefrom

Granted: Jan 19, 1988 Filed: Jan 8, 1987

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.