Granted Patent
Utility
US 4,820,773 · App. 07/067,233
Water absorbent resins prepared by polymerization in the presence of styrene-maleic anhydride copolymers
Inventors:
William Alexander, Mark Anderson, Barbara R. Regan
Patented Case
View Patent ↗
Granted: Apr 11, 1989
Filed: Jun 25, 1987
Inventors
William Alexander
Mark Anderson
Barbara R. Regan
Assignee (at issue)
American Colloid Company
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.