Granted Patent
Utility
US 4,938,846 · App. 06/939,200
Preparation of anhydrous alkanesulfonic acid
Inventors:
Perry D. Comstock, Karen M. Keys
Patented Case
View Patent ↗
Granted: Jul 3, 1990
Filed: Dec 8, 1986
Inventors
Perry D. Comstock
Karen M. Keys
Assignee (at issue)
Atochem North America, Inc.
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.