Granted Patent
Utility
US 5,428,136 · App. 08/099,715
Water-insoluble azo colorants having two azo groups and a 1,4-bis (acetoacetylamino) benzene coupling component
Inventors:
Rudiger Jung, Joachim Weide, Hans Joachim Metz
Patented Case
View Patent ↗
Granted: Jun 27, 1995
Filed: Jul 29, 1993
Inventors
Rudiger Jung
Joachim Weide
Hans Joachim Metz
Assignee (at issue)
Hoechst GmbH
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.