Granted Patent
Utility
US 4,450,047 · App. 06/461,776
Process for recovering anhydrous alkanesulfonic acids by reduced pressure, falling film evaporation
Inventor:
Dale E. Malzahn
Patented Case
View Patent ↗
Granted: May 22, 1984
Filed: Jan 28, 1983
Inventor
Dale E. Malzahn
Assignee (at issue)
Penwalt Corporation
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.