ALEXANDRIA, Va., July 16 -- United States Patent no. 12,357,550, issued on July 15, was assigned to KAO Corp. (Tokyo).
"Hair dyeing composition with improved durability" was invented by Bernd Nocker (Darmstadt, Germany), Steven Breakspear (Darmstadt, Germany), Fariba Ghiasi (Darmstadt, Germany) and Niu Jian (Darmstadt, Germany).
According to the abstract* released by the U.S. Patent & Trademark Office: "A dyeing composition for keratin fibers, including one or more first direct dyes selected from HC Blue 18, HC Red 18, HC Yellow 16, and salts thereof, one or more second direct dyes selected from Disperse Black 9, Acid Yellow 1, 2-amino-6-chloro-4-nitrophenol and salts thereof, and one or more alkalizing agents."
The patent was filed on S...