Granted Patent
Utility
US 6,042,814 · App. 09/061,541
Sulphonic acids and their use as UV absorbers
Inventors:
Oskar Koch, Roland Langner, Alfred Krempel
Patented Case
View Patent ↗
Granted: Mar 28, 2000
Filed: Apr 16, 1998
Inventors
Oskar Koch
Roland Langner
Alfred Krempel
Assignee (at issue)
Haarmann & Reimer 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.