Multi-tonal one step dyeing with thickening pre-treatment solution
A method for dyeing keratin fibers, in particular human hair, in which, after a thickened pretreatment agent (M1) including at least one oxidation dye precursor has been applied and left to act, directly thereafter and without rinsing a coloring agent (M2) is applied and left to act. By virtue of this method, in one dyeing step the hair can be colored and at the same time a multi-tonal dyeing with lighter (“highlights”) or darker (“lowlights”) sections (strands) can be produced.
1. A method for oxidatively dyeing keratin fibers, wherein the method comprises the following method steps in the specified order:
a) applying a cosmetic agent (M1) to the keratin fibers,
b) leaving the agent (M1) to act on the keratin fibers for a duration of from 30 seconds to 40 minutes,
c) applying a cosmetic agent (M2) to the keratin fibers to which the cosmetic agent (M1) was applied,
d) leaving the cosmetic agents (M1) and (M2) to act on the keratin fibers for a duration of from 1 to 70 minutes, and
e) rinsing out the cosmetic agents (M1) and (M2),
wherein
the cosmetic agent (M1) includes
at least one oxidation dye precursor of the developer type (M1-1),
at least one oxidation dye precursor of the coupler type (M1-2),
at least one substantive dye (M1-3), and
at least one thickening agent (M1-4), and
the cosmetic agent (M2) includes
at least one oxidation dye precursor (M2-1), and
at least one oxidizing agent (M2-2).
2. The method according to claim 1 , wherein cosmetic agent (M1) in method step b) is left to act on the keratin fibers for a duration of from 30 seconds to 30 minutes.
3. The method according to claim 1 , wherein cosmetic agent (M1) in method step a) is applied only to individual strands.
4. The method according to claim 1 , wherein cosmetic agents (M1) and (M2) in method step d) are left to act for a duration of from 1 to 60 minutes.
5. The method according to claim 1 , wherein cosmetic agent (M1) includes the at least one oxidation dye precursor of the developer type (M1-1) in a total amount of from 0.002 to 6.0% by weight based on the total weight of the cosmetic agent (M1).
6. The method according to claim 1 , wherein cosmetic agent (M1) includes the at least one oxidation dye precursor of the coupler type (M1-2) in a total amount of from 0.002 to 4.0% by weight based on the total weight of the cosmetic agent (M1).
7. The method according to claim 1 , wherein cosmetic agent (M1) includes the at least one substantive dye (M1-3) in a total amount of from 0.00001 to 5.0% by weight based on the total weight of the cosmetic agent (M1).
8. The method according to claim 1 , wherein the at least one thickening agent (M1-4) is selected from the group consisting of cellulose, cellulose derivatives, xanthan, crosslinked homopolymers or copolymers of acrylic acid, methacrylic acid and salts thereof, crosslinked copolymers of ethoxylated alkyl esters of methacrylic acid and sulfonated acrylamides and salts thereof, crosslinked copolymers of methacrylic acid, acrylamides and sulfonated acrylamides and salts thereof, and mixtures of said thickening agents.
9. The method according to claim 1 , wherein the cosmetic agent (M1) includes the at least one thickening agent (M1-4) in a total amount of from 0.1 to 5.0% by weight, based on the total weight of the cosmetic agent (M1).
10. The method according to claim 1 , wherein the cosmetic agent (M1) has a dynamic viscosity of from 5000 to 90,000 mPa*s measured using a Brookfield RDV II+, spindle no. 4, 4 rpm, 20° C.
11. The method according to claim 1 , wherein cosmetic agent (M1) has a pH of from 7.0 to 14.0.
12. The method according to claim 1 , wherein cosmetic agent (M2) includes as oxidation dye precursor (M2-1) at least one oxidation dye precursor of the developer and/or coupler type.
13. The method according to claim 1 , wherein a ratio of the substance amount of all oxidation dye precursors of the developer type (M1-1) in the cosmetic agent (M1) to the total amount of all oxidation dye precursors (M2-1) in the cosmetic agent (M2) has a value (M1 1):(M2 1) of from 1:5 to 1:2.
14. The method according to claim 1 , wherein a ratio of the substance amount of all oxidation dye precursors of the developer type (M1-1) in the cosmetic agent (M1) to the total amount of all oxidation dye precursors (M2-1) in the cosmetic agent (M2) has a value (M1 1):(M2 1) of from 400:1 to 600:1.
15. The method according to claim 1 , wherein the cosmetic agent (M1) and the cosmetic agent (M2) have identical pH values.
16. The method according to claim 1 , wherein the cosmetic agent (M2) includes at least one oxidizing agent (M2-2) selected from the group consisting of persulfates, peroxodisulfates, chlorites, hypochlorites, hydrogen peroxide and the solid addition products thereof with urea, melamine, polyvinylpyrrolidone and sodium borate, in a total amount of from 0.5 to 10% by weight based on the total weight of the cosmetic agent (M2).