03.04.19
US Patent No. 10,166,175 B1 (Yuri Lvov, Abhishek Panchal, Rawil Fakhrullin); Louisiana Tech Research Corporation, Ruston, LA, has patented a method of coloring hair that entails applying to the hair a coloring mixture for at least one minute. The coloring mixture is comprised of an aqueous-based carrier liquid which is at least 75% by weight water and alumino-silicate micro-tubes having an insoluble hair dye agent loaded into a lumen of the micro-tubes to at least a four weight percent dye loading efficiency. The micro-tubes are present in the carrier liquid in a concentration of between about 5 mg/ml and about 50 mg/ml; and the mixture has a pH of between about 4.0 and about 6.0.