Process for the preparation of stable water based stock solutions of crosslinked lower alkyl vinyl ether and maleic anhydride copolymers and hydrogel product of the process

Granted: Jul 23, 1996 Filed: Dec 19, 1994

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.