Granted Patent
Utility
US 4,923,940 · App. 07/324,530
Polycarboxylic acids with higher thickening capacity and better clarity
Inventor:
Chin C. Hsu
Patented Case
View Patent ↗
Granted: May 8, 1990
Filed: Mar 16, 1989
Inventor
Chin C. Hsu
Assignee (at issue)
B. F. Goodrich 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.