06.01.18
US Patent No. 9,956,155 B2; The Procter & Gamble Company, Cincinnati, OH, has been awarded a patent for a method to straighten naturally curly hair fibers. It is comprised of a crosslinking composition that is comprised of an active agent (wherein the active agent is an amine or diamine and wherein the amine or diamine is selected from the group consisting of 1,7-diaminoheptane, 1,4-diaminobutane, 6-aminohexan-1-ol, 6-amino hexanoic acid, 2-aminoacetic acid, 2-amino-2-oxo-ethanoic acid, 4-aminobutanoic acid, and mixtures thereof); a photocatalyst which is a mixture of 8-hydroxyquinoline and 8-quinolinol-1-oxide; a cosmetically-acceptable carrier. This crosslinking composition has not been exposed to electromagnetic radiation having a wavelength of 750nm or less for 30 minutes or more.
Then, the method entails applying the crosslinking composition to said hair, drying hair and then mechanically straightening the hair fibers with a straightening iron, and exposing the composition to electromagnetic radiation having a wavelength of from about 300nm to about 750nm.
The method, which entails elevating the temperature of the hair straightening iron to a temperature of from about 50°C to about 180°C; does not comprise a rinsing step between steps, according to the patent literature.
Then, the method entails applying the crosslinking composition to said hair, drying hair and then mechanically straightening the hair fibers with a straightening iron, and exposing the composition to electromagnetic radiation having a wavelength of from about 300nm to about 750nm.
The method, which entails elevating the temperature of the hair straightening iron to a temperature of from about 50°C to about 180°C; does not comprise a rinsing step between steps, according to the patent literature.