Here are several hair color patents that were recently awarded by the US Patent Office.
Procter & Gamble Company has patented an oxidative hair coloring composition (Patent No. 8,382,854 B2) comprising a non-ammonia alkalizing agent selected from the group consisting of monoethanolamine, diethanolamine, triethanolamine, monopropanolamine, dipropanolamine, tripropanolamine, 2-amino-2-methyl-1,3-propanediol, 2-amino-2-methyl-1-propanol, 2-amino-2-hydroxymethyl-1,3-propanediol and mixtures thereof; hydrogen peroxide; and oxidative primary dyes.
The weight ratio of said non-ammonia alkalizing agent to hydrogen peroxide is higher than or equal to 1.10, with the proviso that the composition does not comprise a quaternized copolymer of dimethyldiallylammonium and acrylic acid, a quaternized silicone and an acrylate-itaconate copolymer esterified with at least one fatty alcohol.
Kao Corp. has patented a method of oxidative coloring (Patent No. 8,382,855 B2) wherein two compositions (A and B) are mixed prior to application onto hair. Composition A is an acidic composition having a pH between 2 and 5 and comprising at least one oxidizing agent. Composition B is an alkaline composition having a pH between 8 and 12 and comprises one or more oxidative dye precursors, optionally one or more coupling agents and optionally one or more direct dyes.Composition A and/or B comprises one or more surfactants selected from anionic, nonionic and amphoteric ones and their mixtures at a concentration between 1 and 30% by weight calculated to total of compositions A or B and the mixture has a pH below or equal to 7.0. It is applied onto hair from a vessel delivering its content in the form of a foam and is processed for one to 45 minutes at a temperature in the range of 20 to 45°C. It is then rinsed off from hair.
Fujifilm Corporation, Tokyo, has also patented a hair dye (US Patent No. 8,382,856 B2). The dye is comprised of a combination of a first agent containing a substance reacting with iron to develop color and an ultraviolet absorbent having a 2-hydroxybenzophenone skeleton, and a second agent containing iron salt.