	US 12,290,584 B2
	Hair dyeing method using natural dyes and metal salt
Lusine Sargsyan, Hamburg (DE); Hartmut Manneck, Barnitz (DE); Thomas Hippe, Appen (DE); and Volkmar Vill, Hamburg (DE)
Assigned to HENKEL AG & CO. KGAA, Duesseldorf (DE)
Appl. No. 18/254,355
Filed by Henkel AG & Co. KGaA, Duesseldorf (DE)
PCT Filed Oct. 5, 2021, PCT No. PCT/EP2021/077389 § 371(c)(1), (2) Date May 24, 2023, PCT Pub. No. WO2022/111890, PCT Pub. Date Jun. 2, 2022.
Claims priority of application No. 102020214790.6 (DE), filed on Nov. 25, 2020.
Prior Publication US 2024/0016714 A1, Jan. 18, 2024
Int. Cl. A61Q 5/10 (2006.01); A61K 8/19 (2006.01); A61K 8/34 (2006.01); A61K 8/362 (2006.01); A61K 8/9789 (2017.01); A61Q 5/06 (2006.01)

CPC A61K 8/19 (2013.01) [A61K 8/34 (2013.01); A61K 8/362 (2013.01); A61K 8/9789 (2017.08); A61Q 5/065 (2013.01)]

20 Claims

1. A method for the non-oxidative dyeing of keratinous fibers with natural dyes, comprising the following method steps in the order indicated:

a) applying an aqueous composition (T) to the keratinous fibers, the aqueous composition (T) having a pH in the range from about 4.6 to about 5.6, measured at 20° C., said aqueous composition (T) comprising:

i. a polyphenol, wherein the polyphenol;

is available on the Shikimate biosynthesis pathway and

has at least 2 hydroxy groups in the molecule and

has a molecular weight in the range from about 170 to about 20,000 g/mol; wherein said aqueous composition (T) further comprises;

ii. a buffer system selected from a mixture of a moderately strong or weak acid with one or more of a conjugate base of the moderately strong or weak acid, a corresponding base, or a salt of the conjugate base, and a mixture of a moderately strong or weak base with its conjugated or corresponding acid,

b) allowing the aqueous composition (T) to act on the keratinous fibers for a time of from about 30 seconds to about 60 minutes,

c) rinsing the keratinous fibers with water,

d) optionally drying of the keratinous fibers,

e) directly thereafter applying to the keratinouos fibers an aqueous composition (M) having a pH in the range from about 2.5 to about 6.4, measured at 20° C., said aqueous composition (M) comprising:

iii. at least one salt of the divalent iron cation Fe(II) in an amount of about 0.001 to about 3.0 wt. %, based on the weight of the aqueous composition (M),

iv. optionally a buffer system selected from a mixture of a moderately strong or weak acid with one or more of a conjugate base of the moderately strong or weak acid, a corresponding base, or a salt of the conjugate base, and a mixture of a moderately strong or weak base with its conjugated or corresponding acid,

f) allowing the aqueous composition (M) to act on the keratinous fibers for a time of about 30 seconds to about 60 minutes,

g) rinsing the keratinous fibers with water,

h) optional drying of the keratin fibers,

whereby no elemental iron, sponge iron, copper salts or aluminum salts are used in the method, and

wherein the keratinous fibers have not been treated with an oxidizing agent and have not been treated with a keratin reducing agent for a period of at least about 7 days prior to the application of the aqueous composition (T).