Granted Patent
Utility
US 4,918,247 · App. 07/361,711
Process for the preparation of 2,2-dimethylpropanediol-1,3
Inventors:
Norbert Breitkopf, Wolfgang Hofs, Heinz Kalbfell, Franz Thonnessen, Peter Lappe, Helmut Springer
Patented Case
View Patent ↗
Granted: Apr 17, 1990
Filed: May 26, 1989
Inventors
Norbert Breitkopf
Wolfgang Hofs
Heinz Kalbfell
Franz Thonnessen
Peter Lappe
Helmut Springer
Assignee (at issue)
Ruhrchemie Aktiengesellschaft
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.