Granted Patent
Utility
US 5,856,588 · App. 08/774,339
Two-stage etherification of tertiary butyl alcohol using second stage zeolite catalysts for the intermediate preparation of isobutylene
Inventors:
Pei-Shing E. Dai, John F. Knifton
Patented Case
View Patent ↗
Granted: Jan 5, 1999
Filed: Dec 30, 1996
Inventors
Pei-Shing E. Dai
John F. Knifton
Assignee (at issue)
Huntsman Specialty Chemicals 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.