Granted Patent
Utility
US 4,939,192 · App. 07/339,545
Building composition containing 3-alkoxy-2-hydroxypropylhydroxyethyl cellulose
Inventor:
Harald E. t'Sas
Patented Case
View Patent ↗
Granted: Jul 3, 1990
Filed: Apr 17, 1989
Inventor
Harald E. t'Sas
Assignee (at issue)
Aqualon 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.