EP4231988A1

EP4231988A1 - Agents for oxidatively changing the color of keratin fibers, containing a complexing agent, an activator and an oxidant

Info

Publication number: EP4231988A1
Application number: EP21763371.8A
Authority: EP
Inventors: Konstantin Goutsis; Daniela Kessler-Becker
Original assignee: Henkel AG and Co KGaA
Current assignee: Henkel AG and Co KGaA
Priority date: 2020-10-22
Filing date: 2021-08-23
Publication date: 2023-08-30
Also published as: DE102020213334A1; WO2022083922A1

Abstract

The present invention relates to agents for oxidatively changing the color of keratin fibers, in particular human hair, containing: (a) at least one complexing agent of general formula (I); (b) at least one activator from the group of amino acids, protein hydrolysates and radical scavengers; and (c) at least one oxidant.

Description

Means for the oxidative color change of keratin fibers with complexing agent, activator and oxidizing agent

The present invention is in the field of cosmetics and relates to agents for the oxidative color change of keratin fibers, in particular human hair. These agents are characterized in that they contain at least one complexing agent (a) of the formula (I), at least one activator (b) from the group consisting of amino acids, protein hydrolysates and free-radical scavengers and also at least one oxidizing agent (c).

A second subject matter of the present invention relates to a method for the oxidative color change of keratin fibers, in particular human hair, wherein an agent of the first subject matter of the invention is applied to the keratin fibers and rinsed out again after an exposure time.

Changing the shape and color of the hair is an important area of modern cosmetics. In addition to coloring, many consumers want their hair to be lightened or bleached, since a blonde hair color is considered attractive and desirable from a fashion point of view . Various bleaching agents with different bleaching performance are available on the market for this purpose.

The oxidizing agents contained in bleaching agents are able to lighten the hair fiber through the oxidative destruction of the hair's own pigment, melanin. For a moderate bleaching effect, the use of hydrogen peroxide - optionally with the use of ammonia or other alkalizing agents - as the oxidizing agent alone is sufficient. A mixture of hydrogen peroxide and peroxodisulfate salts and/or peroxomonosulfate salts is usually used to achieve a stronger bleaching effect.

If the original hair is dark, longer application times and/or repeated bleaching processes are usually necessary in order to lighten the hair over several shades. However, this is also accompanied by greater damage to the hair, since not only the dyes of the hair but also the other structural components of the hair are damaged by oxidation. Depending on the extent of the damage, it ranges from rough, brittle hair that is difficult to comb through to reduced resistance and tear resistance of the hair to hair breakage. The use of complexing agents in the case of oxidative color changes in keratin fibers is known in the prior art. The complexing agents should, among other things, prevent the decomposition of the hydrogen peroxide by metal ions accumulated in the hair fibers.

Thus, EP 1714634 A1 describes a hair treatment kit for coloring human hair, comprising a first compartment containing a complexing agent and a second compartment containing agents for coloring. The use of a complexing agent is intended to prevent unwanted reactions on and with the hair, which lead to unwanted heating.

In many bleaching products on the market, HEDP (etidronic acid) or its salts or EDTA (ethylenediamine tetraacetate) or its salts are used as complexing agents. Both HEDP and EDTA stabilize hydrogen peroxide in an effective manner and complex existing metal ions so efficiently that an undesirable temperature increase occurring during use is almost completely avoided. However, the major disadvantage of HEDP and EDTA is their poor biodegradability. Particularly in recent times, users have been paying increasing attention to the ecological profile of the cosmetic products they use. The user prefers cosmetics that are as sustainable as possible with biodegradable ingredients.

The use of substances of natural origin as complexing agents is also already known in the literature. For example, EP 1462090 A1 describes agents for bleaching, coloring or shaping hair, which contain the combination of at least one oxidizing agent and at least one polyhydroxycarboxylic acid.

Furthermore, EP 1602356 B1 describes bleaching agents or bleaching agents in which the biodegradable complexing agent ethylenediamine-N,N'-disuccinic acid is used in combination with a persulfate.

However, the performance properties of the agents described in the documents mentioned above are still in need of improvement, and the bleaching performance in particular cannot yet be regarded as optimal. The temperature development that occurs on the head during application still needs further improvement.

The object of the present invention was to find hair treatment agents, in particular bleaching agents or agents for oxidative color change, with biodegradable complexing agents which are as superior as possible to the bleaching or lightening agents known from the prior art in terms of their bleaching performance. Furthermore, the bleaching agents should have a sufficiently high stability and also when used on hair with a higher Do not overheat the metal or heavy metal content. In addition, when using the complexing agents in lightening or bleaching agents, the damage to the hair should be reduced and the feel or feel of the hair should be improved as far as possible.

Surprisingly, it has now been found that this problem can be solved in full if an agent is used on the keratin fibers which, in addition to the oxidizing agent (c) responsible for the lightening, also contains at least one special complexing agent (a) of the formula (I) and an activator from a specific group (b).

A first object of the present invention is an agent for the oxidative color change of keratin fibers, in particular human hair, containing

(a) at least one complexing agent of the general formula (I) whereby

R1, R2 independently represent a carboxyl group or a physiologically acceptable salt thereof, a hydrogen atom, a Ci-Ce-alkyl group, a hydroxy-C2-Ce-alkyl group, a hydroxy group, a carboxy-Ci-Ce-alkyl group or a physiologically acceptable salt thereof,

R3, R4 independently represent a hydrogen atom, a Ci-Ce-alkyl group, a hydroxy-02-Ce-alkyl group, a carboxy-Ci-Ce-alkyl group or a physiologically tolerable salt thereof,

R5 is a hydrogen atom, a Ci-Ce-alkyl group, a hydroxy-C2-Ce-alkyl group, a carboxy-Ci-Ce-alkyl group or a physiologically tolerable salt thereof, m is an integer from 0 to 6, and

M1, M2 independently represent a hydrogen atom or an equivalent of an alkali, alkaline earth or metal ion, preferably sodium, potassium, % magnesium, % calcium, % zinc, or an ammonium ion (NH4 ⁺ ), and

(b) at least one activator from the group consisting of amino acids, protein hydrolysates and radical scavengers and

(c) at least one oxidizing agent. keratin fibers

Keratin fibers or keratin fibers are to be understood as meaning fur, wool, feathers and, in particular, human hair. Although the agents are primarily suitable for treating or lightening keratin fibers, in particular human hair, there is nothing in principle to prevent their use in other areas as well.

Agent for the oxidative color change of keratin fibers

The term “oxidative color change” used according to the invention comprises in principle any possible form of treatment in which the color of the keratin fiber is changed using at least one oxidizing agent. Included in particular in this invention are agents for oxidative coloring, for lightening coloring, for lightening nuances and for lightening, where the lightening can alternatively also be referred to as blonding or bleaching. A lightening is to be understood as meaning any form of color change in the fibers in which the keratin fibers have a lighter color compared to the color present before the application of the agent. The hair is lightened by at least one oxidizing agent present in the composition. In addition to the oxidizing agent or agents, the agents according to the invention can also contain coloring components, such as oxidation dye precursors and/or substantive dyes, for the purpose of lightening. The coloring components can be used to slightly modify the color of the resulting coloring when lightening. However, these coloring components are preferably present in the agent in such small amounts that the color impression of the keratin fibers treated with the agent is nevertheless lighter than their original color. Corresponding coloring techniques can also be referred to as coloring bleaching or as nuanced bleaching.

The agent contains the components (a), (b) and (c) essential to the invention, preferably in a cosmetic carrier. For example, a suitable aqueous, alcoholic or aqueous-alcoholic carrier can be used as a cosmetic carrier for the agent. For the purpose of hair coloring, such carriers are, for example, creams, emulsions, gels, pastes or foaming solutions containing surfactants, such as shampoos, foam aerosols, foam formulations or other preparations which are suitable for use on the hair.

The agent according to the invention is therefore preferably an agent for the oxidative color change of keratin fibers, in particular human hair, contained in a cosmetic carrier

(a) at least one complexing agent of the general formula (I) whereby

R3, R4 independently represent a hydrogen atom, a Ci-Ce-alkyl group, a hydroxy-C2-Ce-alkyl group, a carboxy-Ci-Ce-alkyl group or a physiologically tolerable salt thereof,

(c) at least one oxidizing agent.

This agent according to the invention is a ready-to-use agent that can be applied to the keratin fibers in this form for the purpose of bleaching or lightening or oxidative coloring.

complexing agent (a)

As the first ingredient essential to the invention, the agent according to the invention contains at least one complexing agent (a) of the general formula (I), whereby R1, R2 independently represent a carboxyl group or a physiologically acceptable salt thereof, a hydrogen atom, a Ci-Ce-alkyl group, a hydroxy-C2-Ce-alkyl group, a hydroxy group, a carboxy-Ci-Ce-alkyl group or a physiologically acceptable salt thereof,

M1, M2 independently represent a hydrogen atom or an equivalent of an alkali metal, alkaline earth metal or metal ion, preferably sodium, potassium, % magnesium, % calcium, % zinc, or an ammonium ion (NH4 ⁺ ),

The complexing agents of the formula (I) are described as being biodegradable and therefore represent an ecologically advantageous replacement for HEDP and EDTA. Surprisingly, it has been found that the use of these special complexing agents (a) in the agent according to the invention can also massively improve the bleaching performance .

Examples of the substituents R1 to R5 mentioned in formula (I) are given below by way of example:

Examples of Ci-C6-alkyl radicals are _-CH3 , _-CH2CH3 , -CH2CH2CH3, -CH(CH3) ₂ , -CH2CH(CH3 ₎ ₂ , -CH(CH3)CH2CH3, -C(CH3)3, -(CH2)4CH3, -(CH2)SCH3. Particularly preferred alkyl radicals are methyl and ethyl. Examples of Ci-Ce-hydroxyalkyl groups are -CH2OH, CH2CH2OH, _-CH2CH2CH2OH , -CH2CH(OH)CH3, _{-CH2CH2CH2CH2OH} , with -CH2CH2OH being preferred.

Examples of carboxy-Ci-Ce-alkyl groups are HOOC-CH2-, HOOC-CH2-CH2-, HOOC-CH2-CH2-CH2-, HOOC-CH2-CH2-CH2-CH2-, the group HOOC-CH2- being preferred is.

In the complexing agents of the general formula (I), the radicals R1 and R2 independently represent a carboxyl group or a physiologically tolerable salt thereof, a hydrogen atom, a C 1 -C 4 alkyl group, a hydroxy-C 2 -C 4 alkyl group, a hydroxy group, a carboxy-Ci-Ce-alkyl group or a physiologically tolerable salt thereof.

Physiologically tolerable salts are understood as meaning the salts which can be used in cosmetics under physiological conditions without any adverse effect. Examples of a physiologically acceptable salt of a carboxyl group are sodium salt, potassium salt and ammonium salt. Examples of a physiologically tolerable salt of a carboxy-Ci-Ce- Alkyl groups are, for example, the sodium salt, the potassium salt and the ammonium salt of the carboxy-Ci-Ce-Al ky Ig ru ppe.

A particularly strong improvement in bleaching performance was observed when using agents containing at least one complexing agent (a) of the general formula (I), where the radicals R1 and R2 independently represent a carboxyl group or a physiologically tolerable salt thereof.

In a particularly preferred embodiment, an agent according to the invention is characterized in that it contains at least one complexing agent (a) of the general formula (I), where

R1, R2 independently represent a carboxyl group or a physiologically tolerable salt thereof.

If R1 and R2 independently represent a carboxyl group or a physiologically tolerable salt thereof, the complexing agent (a) has the general structural formula (la) whereby

R5 represents a hydrogen atom, a Ci-Ce-alkyl group, a hydroxy-C2-Ce-alkyl group, a carboxy-Ci-Ce-alkyl group or a physiologically tolerable salt thereof, m represents an integer from 0 to 6,

M1, M2 independently represent a hydrogen atom or an equivalent of an alkali, alkaline earth or metal ion, preferably sodium, potassium, % magnesium, % calcium, % zinc, or an ammonium ion (NH4 ⁺ ), and M3, M4 independently from one another are a hydrogen atom or an equivalent of an alkali, alkaline earth or metal ion, preferably sodium, potassium, % magnesium, % calcium, % zinc, or an ammonium ion (NH4 ⁺ ). In the complexing agents of the general formula (I), the radicals R3 and R4 independently represent a hydrogen atom, a Ci-Ce-alkyl group, a hydroxy-C2-Ce-alkyl group, a carboxy-Ci-Ce-alkyl group or a physiologically tolerable one salt of this.

In bleaching experiments, particularly good results were also achieved when at least one complexing agent (a) of the formula (I) was used in the agent according to the invention, in which the radicals R3 and R4 independently represent a hydrogen atom, a carboxy-Ci-Ce-alkyl group or stand for a physiologically tolerable salt thereof. Very particularly preferably, both radicals R3 and R4 are a hydrogen atom.

In a further particularly preferred embodiment, an agent according to the invention is characterized in that it contains at least one complexing agent (a) of the general formula (I), where

R3, R4 independently represent a hydrogen atom, a carboxy-Ci-Ce-alkyl group or a physiologically tolerable salt thereof, particularly preferably a hydrogen atom.

Accordingly, the agents are particularly preferred which contain (a) at least one complexing agent of the general formula (Ib) whereby

M3, M4 independently represent a hydrogen atom or an equivalent of an alkali, alkaline earth or metal ion, preferably sodium, potassium, % magnesium, % calcium, % zinc, or an ammonium ion (NH4 ⁺ ), and (b) at least an activator from the group consisting of amino acids, protein hydrolysates and radical scavengers and (c) at least one oxidizing agent.

In the complexing agents of the general formula (I), the index number m stands for an integer from 0 to 0. The index number indicates the number of structural units -CH2-CH2-NR5- which are located between the nitrogen atom (or the unit -NR3 -) and the initially adjacent carbon atom of the ethylenediamine.

When m is 1, the complexing agent includes a -CH2-CH2-NR5- moiety. When m is 2, the complexing agent includes two structural units -CH2-CH2-NR5-. When m is 3, the complexing agent includes three structural units -CH2-CH2-NR5-. When m is 4, the complexing agent includes four structural units -CH2-CH2-NR5-. When m is 5, the complexing agent includes five structural units -CH2-CH2-NR5-. Finally, when m is 6, the complexing agent includes six structural units -CH2-CH2-NR5-.

If several structural units --CH.sub.2--CH.sub.2--NR.sub.5-- are present in the complexing agents of the formula (I), the radicals R.sup.5 of each structural unit can in principle be chosen independently of the radicals R.sup.5 of the other structural unit(s).

If m is 0, the complexing agent does not contain a structural unit -CH2-CH2-NR5-, in which case the complexing agent (a) has the general structural formula (Ic) where the radicals R1, R2, R3, R4, M1 and M2 are defined as described above.

The very best results were obtained when a complexing agent (a) of the formula (I) was used in the agents according to the invention, in which the number 0 or 1, very particularly preferably the number 0, stands for this.

In a particularly preferred embodiment, an agent according to the invention is characterized in that it contains at least one complexing agent (a) of the general formula (I), where m is the number 0 or 1, preferably the number 0. Within the scope of a further embodiment, an agent containing is therefore particularly preferred

(a) at least one complexing agent of the general formula (Ic)

(c) at least one oxidizing agent.

Within the scope of a further explicitly very particularly preferred embodiment, an agent according to the invention is accordingly characterized in that it contains

(a) at least one complexing agent of the general formula (Id) whereby M1, M2 independently represent a hydrogen atom or an equivalent of an alkali metal, alkaline earth metal or metal ion, preferably sodium, potassium, % magnesium, % calcium, % zinc, or an ammonium ion (NH?),

M3, M4 independently represent a hydrogen atom or an equivalent of an alkali, alkaline earth or metal ion, preferably sodium, potassium, % magnesium, % calcium, % zinc, or an ammonium ion (NH?).

(b) at least one activator from the group consisting of amino acids, protein hydrolyzates and radical scavengers, and

(c) at least one oxidizing agent.

An explicitly very particularly preferred complexing agent (a) of this embodiment is ethylenediamine disuccinate, which can be used, for example, as a monosodium salt, as a disodium salt, as a trisodium salt or as a tetrasodium salt. The corresponding potassium salts can also be used and are particularly preferred.

The trisodium salt of ethylenediamine disuccinate is alternatively referred to in its (S,S) form as ethylenediamine N,N' disuccinic acid trisodium salt *(S,S), has the CAS number 178949-82-1, and can be found, for example, under commercially available under the trade name Natrlquest E 30 from Innospec Limited. Another alternative name for the trisodium salt of ethylenediamine disuccinate is N,N'-1,2-Ethanediylbis-L-Aspartic acid, trisodium salt. The substance can also be purchased from Innospec under the trade names Enviomet C 140 and Octaquest E 30.

The free acid of this compound is called ethylenediamine disuccinic acid. Ethylenediamine disuccinic acid has the CAS number 20846-91-7 and can alternatively also be referred to as /V,/V-1,2-ethanediylbis-L-aspartic acid or as ethylenediamine disuccinic acid.

Ethylenediamine disuccinic acid or the salts thereof are often also abbreviated as EDDS in the literature.

Ethylenediamine disuccinate has two stereogenic centers. Both the (S,S) form and the (R,R) form as well as the (R,S) form and the (S,R) form are according to the invention.

To further optimize the bleaching or lightening effect, the complexing agent(s) (a) is/are preferably used in specific quantity ranges in the agent according to the invention. It is very particularly preferred if the agent - based on the total weight of the agent - contains one or more complexing agents (a) of the formula (I) in a total amount of from 0.05 to 10.0% by weight, preferably from 0 .05 to 7.5% by weight, more preferably from 0.05 to 2.5% by weight and very particularly preferably from 0.05 to 1.5% by weight. In a particularly preferred embodiment, an agent according to the invention is characterized in that it contains one or more complexing agents (a) of the formula (I) in a total amount of from 0.05 to 10.0% by weight, based on the total weight of the agent. , preferably from 0.05 to 7.5% by weight, more preferably from 0.05 to 2.5% by weight and very particularly preferably from 0.05 to 1.5% by weight.

In a further particularly preferred embodiment, an agent according to the invention is characterized in that it contains one or more complexing agents (a) of the formula (Ia) in a total amount of from 0.05 to 10.0% by weight, based on the total weight of the agent. %, preferably from 0.05 to 7.5% by weight, more preferably from 0.05 to 2.5% by weight and very particularly preferably from 0.05 to 1.5% by weight.

In a further particularly preferred embodiment, an agent according to the invention is characterized in that it contains one or more complexing agents (a) of the formula (Ib) in a total amount of from 0.05 to 10.0% by weight, based on the total weight of the agent. %, preferably from 0.05 to 7.5% by weight, more preferably from 0.05 to 2.5% by weight and very particularly preferably from 0.05 to 1.5% by weight.

In a further particularly preferred embodiment, an agent according to the invention is characterized in that it contains one or more complexing agents (a) of the formula (Ic) in a total amount of from 0.05 to 10.0% by weight, based on the total weight of the agent. %, preferably from 0.05 to 7.5% by weight, more preferably from 0.05 to 2.5% by weight and very particularly preferably from 0.05 to 1.5% by weight.

In a further particularly preferred embodiment, an agent according to the invention is characterized in that it contains one or more complexing agents (a) of the formula (Id) in a total amount of from 0.05 to 10.0% by weight, based on the total weight of the agent. , preferably from 0.05 to 7.5% by weight, more preferably from 0.05 to 2.5% by weight and very particularly preferably from 0.05 to 1.5% by weight.

activator (b)

The agent according to the invention contains at least one activator (b) from the group consisting of amino acids, protein hydrolysates and free-radical scavengers as the second essential component of the invention.

For the purposes of the present invention, an activator is a substance which is able to further improve the performance, in particular the bleaching performance, of the complexing agent (a). The work carried out within the scope of this invention has shown that as activators (b) Compounds from the group of amino acids, protein hydrolysates and radical scavengers have a good effect.

The agents for oxidative color change that contained at least one activator (b) from the group of amino acids have shown particularly good performance.

In a further embodiment, a very particularly preferred agent according to the invention is characterized in that it contains at least one activator (b) from the group of amino acids, preferably from the group of glycine, lysine, arginine, histidine, asparagine, glutamine, cysteine, methionine, tryptophan, serine, alanine, aspartic acid, glutamic acid, isoleucine, leucine, phenylalanine, proline, threonine, tyrosine and valine.

Accordingly, preference is given to agents for the agents for the oxidative color change of keratin fibers containing,

(a) at least one complexing agent of the general formula (I), preferably of the formula (Ia), (Ib), (Ic) and/or (Id),

(b) at least one amino acid from the group consisting of glycine, lysine, arginine, histidine, asparagine, glutamine, cysteine, methionine, tryptophan, serine, alanine, aspartic acid, glutamic acid, isoleucine, leucine, phenylalanine, proline, threonine, tyrosine and valine, and

(c) at least one oxidizing agent.

An amino acid means a chemical compound with an amino group and a carboxylic acid group. The class of amino acids includes organic compounds that contain at least one amino group (-NH2 or substituted -NR2) and one carboxy group (-COOH) as functional groups, i.e. have structural features of amines and carboxylic acids. Chemically, they can be distinguished according to the position of their amino group in relation to the carboxy group - if the amino group on the Ca atom is immediately adjacent to the terminal carboxy group, this is called a-position and is referred to as a-amino acids. Preference is given to using carboxylic acids having a total number of carbon atoms from C2-C20, more preferably from C2-C15, particularly preferably from C2-C10.

In a further particularly preferred embodiment, an agent according to the invention is characterized in that it contains at least one amino acid (b) from the group consisting of glycine, lysine, arginine, histidine, asparagine, glutamine, cysteine, methionine, tryptophan, serine, alanine, aspartic acid, Glutamic acid, isoleucine, leucine, phenylalanine, proline, threonine, tyrosine and valine

When using the agents according to the invention, compared to the original hair, a particularly high color shift (ie a particularly high delta-E value) can be achieved if the agents according to the invention contain at least one amino acid (b) from the group consisting of glycine, lysine and contained arginine.

Agents containing at least one amino acid (b) from the group consisting of glycine, lysine and arginine are therefore very particularly preferred with a view to improving the lightening performance.

If the amino acids lysine and/or glycine were used in the agent according to the invention, it was also possible to have a particularly positive influence on the temperature profile occurring during use. For this reason, the amino acids lysine and glycine are most preferred.

Explicitly most of all and very particularly preferred are therefore agents for the oxidative color change of keratin fibers containing

(b) at least one amino acid from the group consisting of glycine and lysine, and

(c) at least one oxidizing agent.

Chiral amino acids have a sterogenic center and can occur in mirror image forms. For example, arginine occurs in the form of L-arginine and D-arginine. Both the L-form of an amino acid and its D-form and mixtures thereof are encompassed by the present invention. Accordingly, within the scope of the present invention, both possible enantiomers can be used equally as a specific compound or mixtures thereof, in particular as racemates. However, it is particularly advantageous to use the naturally occurring isomer form, usually in the L configuration.

Accordingly, a particularly preferred agent according to the invention is characterized in that it contains at least one amino acid (b) from the group consisting of glycine, L-lysine, L-arginine, L-histidine, L-asparagine, L-glutamine, L-cysteine, L -Methionine, L-Tryptophan, L-Serine, L-Alanine, L-Aspartic Acid, L-Glutamic Acid, L-Isoleucine, L-Leucine, L-Phenylalanine, L-Proline, L-Threonine, L-Tyrosine and L-Valine contains.

In order to achieve the best possible results, in particular good lightening results, the amino acid(s) (b) are preferably used in specific quantity ranges. It has proven to be particularly advantageous if the agent - based on its total weight - contains one or more amino acids (b) in a total amount of 0.1 to 10.0% by weight, preferably 0.1 to 5.0% by weight. -% contains, more preferably from 0.1 to 2.5% by weight and very particularly preferably from 0.1 to 1.0% by weight.

Another particularly preferred embodiment is one according to the invention Agent characterized in that it contains one or more amino acids (b) in a total amount of 0.1 to 10.0% by weight, preferably 0.1 to 5.0% by weight, based on the total weight of the agent , more preferably from 0.1 to 2.5% by weight and very particularly preferably from 0.1 to 1.0% by weight.

Furthermore, good results could be obtained if on average at least one protein hydrolyzate was used as activator (b).

According to the invention, protein hydrolyzates are degradation products of proteins which are produced by acidic, basic or enzymatic reactions. Due to the manufacturing process, protein hydrolysates have a distribution of molecular weights. The protein hydrolyzates according to the invention also include oligopeptides, since these can also be produced from proteins by appropriate reactions. According to the invention, individual amino acids which are present as discrete individual compounds are not among the protein hydrolyzates in the context of this invention. According to the invention, protein hydrolyzates of both plant and animal or marine or synthetic origin can be used.

For the purposes of the present invention, protein hydrolyzates are understood to mean at most oligomeric compounds composed of a maximum of 10 amino acids.

Animal protein hydrolysates are, for example, elastin, collagen, keratin, silk and milk protein hydrolysates, which can also be present in the form of salts. Such products are sold, for example, under the trademarks Dehylan® (Cognis), Promois® (Interorgana), Collapuron® (Cognis), Nutrilan® (Cognis), Gelita-Sol® (Deutsche Gelatine Fabriken Stoess & Co), Lexein® (Inolex), ProSina® (Croda) and Kerasol® (Croda).

Furthermore, vegetable protein hydrolysates which are preferred according to the invention are, for example, soybean, almond, pea, moringa, potato and wheat protein hydrolysates. Such products are available, for example, under the trademarks Gluadin® (Cognis), DiaMin® (Diamalt), Lexein® (Inolex), Hydrosoy® (Croda), Hydrolupin® (Croda), Hydrosesame® (Croda), Hydrotritium® (Croda), Crotein ® (Croda) and Puricare® LS 9658 from Laboratoires Serobiologiques.

Another particularly well suited vegetable protein hydrolyzate is the raw material Gluadin®Kera-P LM, which is a “hydrolyzed vegetable protein” and can be purchased commercially, for example, from the company BASF.

Further protein hydrolyzates preferred according to the invention are of maritime origin. These include, for example, collagen hydrolysates from fish or algae and protein hydrolysates from mussels or pearl hydrolysates. Examples of pearl extracts according to the invention are the commercial products Pearl Protein Extract BG® or Crodarom® Pearl.

Furthermore, cationized protein hydrolyzates are among the protein hydrolyzates, the underlying protein hydrolyzate from animals, for example from collagen, milk or keratin, from plants, for example from wheat, corn, rice, potatoes, soybeans or almonds, from marine life forms, for example from fish collagen or algae, or biotechnologically obtained protein hydrolyzates. Typical examples of the cationic protein hydrolyzates and derivatives according to the invention are those under the INCI designations in the "International Cosmetic Ingredient Dictionary and Handbook", (seventh edition 1997, The Cosmetic, ^Toiletry , and Fragrance Association 1101 17th Street, NW, Suite 300 , Washington, DC 20036-4702) and commercially available products.

Good results were observed when the agent according to the invention contained at least one protein hydrolyzate selected from the group consisting of vegetable protein hydrolyzates, protein hydrolyzates of elastin, collagen, keratin, silk, milk protein, soya, almond, pea , moringa, potato and wheat protein hydrolysates.

In a further particularly preferred embodiment, an agent according to the invention is characterized in that it contains at least one protein hydrolyzate (b), which is preferably selected from the group of vegetable protein hydrolyzates, protein hydrolyzates of elastin, collagen, keratin, and silk , milk protein, soy, almond, pea, moringa, potato and wheat protein hydrolysates.

In the context of this embodiment, agents according to the invention that are particularly preferred are characterized in that they contain

(b) at least one protein hydrolyzate from the group of vegetable protein hydrolysates, elastin, collagen, keratin, silk, milk protein, soy, almond, pea, moringa, potato and wheat protein hydrolysates, and

(c) at least one oxidizing agent.

In order to achieve the best possible results, in particular good lightening results, the protein hydrolyzates (b) are preferably used in specific quantity ranges. It has proven to be particularly advantageous if the agent - based on the total weight of the agent - one or more protein hydrolyzates (b) in a total amount of 0.1 to 10.0 wt .-%, preferably 0.1 to 5.0 % by weight, more preferably from 0.1 to 2.5% by weight and most particularly preferably from 0.1 to 1.0% by weight.

Within the scope of a further particularly preferred embodiment, an agent according to the invention is characterized in that it contains one or more protein hydrolyzates (b) in a total amount of from 0.1 to 10.0% by weight, preferably 0, based on the total weight of the agent. 1 to 5.0% by weight, more preferably from 0.1 to 2.5% by weight and very particularly preferably from 0.1 to 1.0% by weight.

Protein hydrolyzates according to the invention are also oligopeptides. Oligopeptides can be preferred in the hair treatment agents according to the invention because of their defined amino acid sequence.

An oligopeptide having at least one amino acid sequence Glu-Glu-Glu has, where the amino group can be free or profaned and the carboxy groups can be free or deprotonated, can be particularly preferred according to the invention. In this, as in all the following formulas, the bracketed hydrogen atom of the amino group as well as the bracketed hydroxy group of the acid function means that the relevant groups can be present as such (then it is an oligopeptide with the relevant number of amino acids as in the above formula, or that the amino acid sequence is present in an oligopeptide which comprises further amino acids - depending on where the further amino acid(s) is/are bound, the bracketed components of the above formula are replaced by the further amino acid residue(s). ) replaced.

For the purposes of the present application, oligopeptides are condensation products of amino acids linked by peptide bonds in the manner of acid amides, which comprise at least 3 and at most 25 amino acids. In hair treatment compositions preferred according to the invention, the oligopeptide comprises 5 to 15 amino acids, preferably 6 to 13 amino acids, particularly preferably 7 to 12 amino acids and in particular 8, 9 or 10 amino acids. Depending on whether other amino acids are bound to the Glu-Glu-Glu sequence and depending on the type of these amino acids, the molar mass of the oligopeptide contained in the agents according to the invention can vary. Hair treatment agents that are preferred according to the invention are characterized in that the oligopeptide has a molar mass of 650 to 3000 Da, preferably 750 to 2500 Da, particularly preferably 850 up to 2000 Da and in particular from 1000 to 1600 Da. As can be seen from the preferred number of amino acids in the oligopeptides and the preferred molar mass range, oligopeptides are preferably used which do not consist solely of the three glutamic acids but also have other amino acids bound to this sequence. These further amino acids are preferably selected from certain amino acids, while certain other representatives are less preferred according to the invention. A particularly preferred oligopeptide additionally contains tyrosine, which is preferably linked to the Glu-Glu-Glu sequence via its acid function. Hair treatment agents which are preferred according to the invention are therefore characterized in that the oligopeptide contained in them contains at least one amino acid sequence Tyr-Glu-Glu-Glu has, wherein the amino group can be free or profaned and the carboxy groups can be free or deprotonated.

Another particularly preferred oligopeptide additionally contains isoleucine, which is preferably bound to the Glu-Glu-Glu sequence via its amino function. Preferred according to the invention

Hair treatment agents are therefore characterized in that the contained in them

Oligopeptide having at least one amino acid sequence Glu-Glu-Glu-Ile has, wherein the amino group can be free or profaned and the carboxy groups can be free or deprotonated.

According to the invention, preference is given to oligopeptides which contain both of the aforementioned amino acids (tyrosine and isoleucine). Hair treatment agents according to the invention in which the oligopeptide contained in them has at least one amino acid sequence Tyr-Glu-Glu-Glu-Ile

has, wherein the amino group can be free or profaned and the carboxy groups can be free or deprotonated.

Further preferred oligopeptides additionally contain arginine, which is preferably present bound to isoleucine

Even more preferred oligopeptides additionally contain valine, which is preferably bound to the arginine. Hair treatment agents that are further preferred according to the invention are therefore characterized in that the oligopeptide contained in them contains at least one amino acid sequence Tyr-Glu-Glu-Glu-Glu-Ile-Arg-Val

Groups can be free or profaned and the carboxy groups can be free or deprotonated.

Even more preferred oligopeptides additionally contain leucine, which is preferably bound to the valine. Hair treatment agents which are further preferred according to the invention are characterized in that the oligopeptide contained in them contains at least one amino acid sequence Tyr-Glu-Glu-Glu-Ile-Arg-Val-Leu where the amino groups can be free or profaned and the carboxy groups can be free or deprotonated.

Particularly preferred oligopeptides also contain leucine, which is preferably attached to the bound to tyrosine. Hair treatment agents which are further preferred according to the invention are characterized in that the oligopeptide contained in them contains at least one amino acid sequence Leu-Tyr-Glu-Glu-Glu-Ile-Arg-Val-Leu has, wherein the amino groups can be free or profaned and the carboxy groups can be free or deprotonated.

In the course of further work leading to this invention, it was found that free-radical scavengers are also very suitable as activator (b).

A free-radical scavenger for the purposes of the present invention is understood to mean substances that react with reactive free radicals, such as hydroxy radicals, and convert them into less reactive species through a series of rapid reactions, thereby interrupting the free radical chain reaction.

The radical scavengers suitable for use in cosmetics can be assigned to specific groups. The use of one or more radical scavengers from the group consisting of unsaturated organic compounds, antioxidants, quinones and thiols has proven to be particularly suitable for use in the lightening or bleaching agents according to the invention.

In a further particularly preferred embodiment, an agent according to the invention is characterized in that it contains at least one activator (b) from the group of free-radical scavengers, preferably from the group of unsaturated organic compounds, antioxidants, quinones and thiols.

It has proven to be very particularly preferred for solving the task according to the invention to use at least one free-radical scavenger (b) from the group of unsaturated organic compounds in the agent according to the invention. Under an unsaturated organic Compound means an organic compound with at least one carbon-carbon double bond.

The use of at least one mono- or polyunsaturated Cs-Cso-fatty acid and/or the derivative of a mono- or polyunsaturated Cs-Cso-fatty acid has proved particularly advantageous.

According to the invention, unsaturated fatty acids are mono- or polyunsaturated, unbranched or branched, unsubstituted or substituted Cs-Cs0-carboxylic acids. Unsaturated fatty acids can be monounsaturated or polyunsaturated. In the case of an unsaturated fatty acid, its C-C double bond(s) can have the cis or trans configuration.

Within the scope of a further very particularly preferred embodiment, an agent according to the invention is characterized in that it contains at least one free-radical scavenger (b) from the group of unsaturated Cs-Cso-fatty acids and their derivatives.

Examples of an unsaturated Cs-Cso fatty acid are petroselinic acid [(Z)-6-octadecenoic acid], palmitoleic acid [(9Z)-hexadec-9-enoic acid], oleic acid [(9Z)-octadec-9-enoic acid], elaidic acid [( 9E)-octadec-9-enoic acid], erucic acid [(13Z)-docos-13-enoic acid], linoleic acid [(9Z,12Z)-octadeca-9,12-dienoic acid, linolenic acid [(9Z,12Z,15Z)-octadeca -9,12,15-trienoic acid, elaeostearic acid [(9Z,11E,13E)-octadeca-9,11,3-trienoic acid], arachidonic acid [(5Z,8Z,11Z,14Z)-lcosa-5,8 ,11,14-tetraenoic acid] and/or nervonic acid [(15Z)-tetracos-15-enoic acid], very particularly preferably unsaturated Cs-Cso-fatty acids are linoleic acid [(9Z, 12Z)-octadeca-9,12-dienoic acid, Linolenic acid [(9Z,12Z,15Z)-octadeca-9,12,15-trienoic acid.

In a further particularly preferred embodiment, an agent according to the invention is characterized in that it contains at least one free-radical scavenger (b) selected from the group consisting of petroselinic acid [(Z)-6-octadecenoic acid], palmitoleic acid [(9Z)-hexadec-9- enoic acid], oleic acid [(9Z)-octadec-9-enoic acid], elaidic acid [(9E)-octadec-9-enoic acid], erucic acid [(13Z)-docos-13-enoic acid], linoleic acid [(9Z, 12Z)- Octadeca-9,12-dienoic acid, linolenic acid [(9Z,12Z,15Z)-octadeca-9,12,15-trienoic acid, elaeostearic acid [(9Z,11E,13E)-octadeca-9,11,3-trienoic acid], Arachidonic acid [(5Z,8Z,11Z,14Z)-cosa-5,8,11,14-tetraenoic acid] and/or nervonic acid [(15Z)-tetracos-15-enoic acid] are very particularly preferably unsaturated Cs-Cso fatty acids linoleic acid [(9Z,12Z)-octadeca-9,12-dienoic acid, linolenic acid [(9Z,12Z,15Z)-octadeca-9,12,15-trienoic acid.

Examples of very particularly suitable unsaturated Cs-Cso fatty acids are linoleic acid and linolenic acid. These are essential fatty acids, which are also known in the literature under the name vitamin F. In another very particularly preferred embodiment, an agent according to the invention is characterized in that it contains at least one free-radical scavenger (b) selected from the group consisting of linoleic acid and linolenic acid.

Particularly suitable derivatives of Cs-Cso fatty acids are their esters.

An ester of an unsaturated Cs-Cso fatty acid is characterized by the presence of an ester functional group, which is obtained by esterification of the acid function of the fatty acid with an alcohol. This alcohol can be a monohydric alcohol or polyhydric alcohol, which can optionally also carry other functional groups or substituents.

Examples of monohydric alcohols are methanol, ethanol, n-propanol, isopropanol, n-butanol, n-pentanol, n-hexanol, n-heptanol, n-octanol, n-nonanol, n-decanol, n-undecanol, n -dodecanol, n-tetradecanol, n-hexadecanol and n-octadecanol.

Examples of polyhydric alcohols are 1,2-propanediol, 1,3-propanediol and glycerol. Glycerin is particularly preferred.

Further examples of the esters of unsaturated Cs-Cso-fatty acids are corresponding fatty acid monoglycerides, fatty acid diglycerides and fatty acid triglycerides.

A Cs-Cso-fatty acid monoglyceride is understood as meaning the monoester of the trihydric alcohol glycerol with one equivalent of unsaturated Cs-Cso-fatty acid. Here, either the central hydroxy group of the glycerol or the terminal hydroxy group of the glycerol can be esterified with the fatty acid.

The Ci2-C30 fatty acid monoglycerides are particularly suitable in which a hydroxy group of the glycerol is esterified with a fatty acid, the fatty acids being selected from petroselinic acid [(Z)-6-octadecenoic acid], palmitoleic acid [(9Z)-hexadec -9-enoic acid], oleic acid [(9Z)-octadec-9-enoic acid], elaidic acid [(9E)-octadec-9-enoic acid], erucic acid [(13Z)-docos-13-enoic acid], linoleic acid [(9Z, 12Z)-octadeca-9,12-dienoic acid, linolenic acid [(9Z,12Z,15Z)-octadeca-9,12,15-trienoic acid, elaeostearic acid [(9Z,11E,13E)-octadeca-9,11,3- trienoic acid], arachidonic acid [(5Z,8Z,11Z,14Z)-cosa-5,8,11,14-tetraenoic acid] or nervonic acid [(15Z)-tetracos-15-enoic acid],

A Ci2-C3o-fatty acid diglyceride is understood to mean the diester of the trihydric alcohol glycerol with two equivalents of Cs-Cso-fatty acid, with at least one fatty acid being one unsaturated Cs-Cso fatty acid must act. Here, either the central and one terminal hydroxy group of the glycerol can be esterified with two equivalents of fatty acid, or both terminal hydroxy groups of the glycerol are each esterified with one fatty acid. The glycerol can be esterified either with two structurally identical fatty acids or with two different fatty acids, with the proviso that at least one fatty acid is an unsaturated Cs-Cso-fatty acid.

The fatty acid diglycerides are particularly suitable if at least one of the ester groups is formed from glycerol with a fatty acid selected from petroselinic acid [(Z)-6-octadecenoic acid], palmitoleic acid [(9Z)-hexadec-9- enoic acid], oleic acid [(9Z)-octadec-9-enoic acid], elaidic acid [(9E)-octadec-9-enoic acid], erucic acid [(13Z)-docos-13-enoic acid], linoleic acid [(9Z, 12Z)- Octadeca-9,12-dienoic acid, linolenic acid [(9Z,12Z,15Z)-octadeca-9,12,15-trienoic acid, elaeostearic acid [(9Z,11E,13E)-octadeca-9,11,3-trienoic acid], arachidonic acid [(5Z,8Z,11Z,14Z)-cosa-5,8,11,14-tetraenoic acid] or nervonic acid [(15Z)-tetracos-15-enoic acid],

A C 2 -C 30 fatty acid triglyceride is understood as meaning the triester of the trihydric alcohol glycerol with three equivalents of C s -C 50 fatty acid, where at least one fatty acid must be an unsaturated C s -C 50 fatty acid. The glycerol can be esterified either with three structurally identical or with different fatty acids, with the proviso that at least one fatty acid is an unsaturated Cs-Cso-fatty acid.

Fatty acid triglycerides are particularly suitable if at least one of the ester groups is formed from glycerol with a fatty acid selected from petroselinic acid [(Z)-6-octadecenoic acid], palmitoleic acid [(9Z)-hexadec-9- enoic acid], oleic acid [(9Z)-octadec-9-enoic acid], elaidic acid [(9E)-octadec-9-enoic acid], erucic acid [(13Z)-docos-13-enoic acid], linoleic acid [(9Z, 12Z)- Octadeca-9,12-dienoic acid, linolenic acid [(9Z,12Z,15Z)-octadeca-9,12,15-trienoic acid, elaeostearic acid [(9Z,11E,13E)-octadeca-9,11,3-trienoic acid], arachidonic acid [(5Z,8Z,11Z,14Z)-lcosa-5,8,11,14-tetraenoic acid] or nervonic acid [(15Z)-tetracos-15-enoic acid],

The free-radical scavengers (b) from the group of phosphoglycerides have proven to be explicitly very particularly well suited for solving the task according to the invention. Phosphoglycerides fall under the group of esters of Cs-Cso fatty acids.

In this context, phosphoglycerides according to the invention are substances which can alternatively also be referred to as glycerophospholipids/phosphoglycerolipids. Phosphoglycerides according to the present invention are made up of glycerol which is esterified with two Cs-Cso fatty acids on two of the hydroxy groups (OH groups) of the glycerol, with the proviso that at least one fatty acid is an unsaturated Cs-Cso fatty acid . A phosphate group is bound to one of the third, terminal OH groups. This phosphate group is in turn esterified with different alcohols. The phosphate group forms a phosphoric acid diester.

The radical scavengers (b) from the group of lecithins are explicitly very particularly preferred.

Within the scope of a further explicitly very particularly preferred embodiment, an agent according to the invention is characterized in that it contains at least one free-radical scavenger (b) of the general formula (II).

0

_H2C - ₀ -U-R6

₀ hi — o — U — _R7 o CH3

H2 - o J - ₀ - _CH2 - CH CH ₃

1 © 1 ö CH

0 ₃ (II) where

R6, R7 independently represent a saturated or unsaturated C11-C29 alkyl group, with the proviso that at least one of R6 and R7 represents an unsaturated Cn-C29 alkyl group.

The radicals R6 and/or R7 can preferably represent the following radicals. Together with the carbonyl group adjacent to the R6 or R7 radical, this radical forms the esterified form of the fatty acid given in the table:

At least one of the radicals R6 and/or R7 is preferably an at least monounsaturated C 16 -C 20 -alkyl group, particularly preferably an at least doubly unsaturated C 16 -C 20 -alkyl group and explicitly very particularly preferably an at least threefold unsaturated C 16 -C 20 - Alky Ig roup .

In a further explicitly very particularly preferred embodiment, an agent according to the invention is characterized in that it contains at least one free-radical scavenger (b) of the general formula (II), where at least one of the radicals R6 and/or R7 is an at least monounsaturated C15-C21 -alkyl group, particularly preferably an at least doubly unsaturated cis-C2i-alkyl group and explicitly very particularly preferably an at least tri-unsaturated cis-C2i-alkyl group.

In a further explicitly very particularly preferred embodiment, an agent according to the invention is characterized in that it contains at least one free-radical scavenger (b) of the general formula (II), where at least one of the radicals R6 and/or R7 is a diunsaturated Cv-alkyl group or stands for a tri-unsaturated Cv-alkyl group.

If one of the remaining radicals R6 or R7 is a saturated Cn-C29-alkyl group, this group can preferably be a saturated Cn-alkyl group, a saturated C13-alkyl group, a saturated Cis-alkyl group, a saturated Cv-alkyl group, a saturated C19 alkyl group or a saturated C2i alkyl group.

Soybean lecithin, which can be purchased commercially under the trade name Lipoid P20 from Lipoid GmbH, can be used as an explicitly very particularly suitable lecithin of the formula (II). This raw material has a phosphatidylcholine (=lecithin) content of at least 20% by weight, with at least 61% by weight of the fatty acids being linoleic acid or linolenic acid, based on the total content of the fatty acids obtained after hydrolysis of the lecithin .

Agents according to the invention that are very particularly preferred within the scope of this embodiment are characterized in that they contain

(b) at least one radical scavenger of the general formula (II), and

(c) at least one oxidizing agent.

Vitamin F, vitamin E, vitamin C, vitamin A, vitamin B and vitamin H have proven to be well suited as radical scavengers (b) from the group of antioxidants.

Vitamin F: As already described above, the term vitamin F usually means essential fatty acids, in particular linoleic acid, linolenic acid.

Vitamin E: Vitamin E is a collective term for fat-soluble substances with mostly antioxidant effects. The most common forms of vitamin E are called tocopherols and tocotrienols. A-tocopherol can be used as a particularly well suited vitamin E. Alternatively, a-tocopherol is also known as (2/?)-2,5,7,8-tetramethyl-2-[(4R,8/?)-4,8,12-trimethyltridecyl]-

3.4-dihydro-2/7-chromen-6-ol or E 307 and has the CAS number 10191-41-0.

The group of substances known as vitamin A includes retinol (vitamin Ai) and

3.4-didehydroretinol (vitamin A2). ß-carotene is the provitamin of retinol. According to the invention, suitable vitamin A components are, for example, vitamin A acid and its esters, vitamin A aldehyde and vitamin A alcohol and its esters such as palmitate and acetate.

Vitamin C (ascorbic acid) and its esters, in particular ascorbyl palmitate, are also suitable according to the invention.

The vitamin B group or vitamin B complex includes u.

• Vitamin Bi (thiamine)

• Vitamin B2 (riboflavin)

• Vitamin B3. The compounds nicotinic acid and nicotinamide (niacinamide) are often referred to under this name, among which nicotinamide is particularly preferred according to the invention.

• Vitamin Bs (pantothenic acid and panthenol). Within this group, preference is given to using panthenol. Derivatives of panthenol that can be used according to the invention are, in particular, the esters and ethers of panthenol, cationically derivatized panthenols and pantolactone.

• Vitamin Be (pyridoxine as well as pyridoxamine and pyridoxal).

Vitamin H. The compound (3aS,4S,6aR)-2-oxohexahydrothienol[3,4-cf]imidazole-4-valeric acid is known as vitamin H, for which the trivial name biotin has meanwhile prevailed.

In a further preferred embodiment, an agent according to the invention is characterized in that it contains at least one radical scavenger (b) from the group consisting of vitamin F, vitamin E, vitamin C, vitamin A, vitamin B and vitamin H.

In a further particularly preferred embodiment, an agent according to the invention is characterized in that it contains at least one radical scavenger (b) from the group consisting of vitamin F, vitamin E, vitamin C and vitamin A.

Compounds from the group of quinones are also suitable as radical scavengers (b). Quinones are understood as meaning organic compounds which have a quinoid system. Suitable representatives from the group of quinones are 1,4-benzoquinone, 1,4-naphthoquinone and 2-hydroxy-1,4-naphthoquinone. Also 1,4-benzoquinones and1,4-naphthoquinones, such as at least a substituent such as a hydroxy group, an amino group, a nitro group, a carboxylic acid group, a Ci-Ce-alkyl group, a Ci-Ce-alkoxy group are suitable.

Examples of suitable radical scavengers (b) from the group of thiols are thiolactic acid, ammonium thioglycolate and ammonium thiolactate.

Thiolactic acid is understood to mean D-thiolactic acid, L-thiolactic acid and/or a mixture thereof. Cysteine is understood to mean D-cysteine, L-cysteine and/or a mixture thereof.

Ammonium thioglycolate is the ammonium salt of thiglycolic acid (ie

ammonium salt of sulfanylacetic acid) (formula thiol-I)

.coo-

[ ( _NH4 )+

^SH (Formula Thiol-I)

Ammonium thiolactate is the ammonium salt of thiolactic acid (ie the ammonium salt of 2-sulfanylpropionic acid) (formula Thiol-II). (Formula Thiol-II)

The definition of ammonium thiolactate also includes both the ammonium salts of D-thiolactic acid and the salts of L-thiolactic acid and mixtures thereof.

To optimize the desired effect, the free-radical scavengers (b) are also preferably used in specific quantity ranges in the composition according to the invention.

It has been found to be particularly advantageous if the agent - based on the total weight of the agent - one or more radical scavengers (b) in a total amount of 0.01 to 10.0 wt .-%, preferably 0.25 to 7. 0% by weight, more preferably from 0.25 to 6.0% by weight and most preferably from 0.25 to 2.5% by weight.

Weight ratio (a)/(b)

The work leading to this invention has shown that there appears to be a synergistic effect between components (a) and (b). When both components (a) and (b) are used in an agent for oxidative color change, it has been shown that (a) and (b) together improve the lightening performance particularly greatly when they average in a specific weight ratio to one another available. For this reason it has turned out to be very particularly preferred if the weight ratio of all complexing agents (a) of the formula (I) present in the agent to all activators (b) present in the agent, ie the weight ratio (a)/(b), is from 0.1 to 10, preferably from 0.2 to 5, more preferably from 0.25 to 4.0, and very particularly preferably from 0.3 to 1.0.

In a further preferred embodiment, an agent according to the invention is characterized in that the weight ratio of all the complexing agents (a) contained in the agent to all the activators (b) contained in the agent, i.e. the weight ratio (a)/(b), has a value of 0.1 to 10, preferably from 0.2 to 5, more preferably from 0.25 to 4.0, and very particularly preferably from 0.3 to 1.0.

It is preferred if the weight ratio of all complexing agents (a) contained in the average to all amino acids (b) contained in the average, i.e. the weight ratio (a)/(b), has a value of from 0.1 to 10, preferably from 0 .2 to 5, more preferably from 0.25 to 4.0, and very particularly preferably from 0.3 to 1.0.

It is preferred if the weight ratio of all complexing agents (a) contained in the average to all protein hydrolyzates (b) contained in the average, i.e. the weight ratio (a)/(b), has a value of from 0.1 to 10, preferably from 0 .2 to 5, more preferably from 0.25 to 4.0, and very particularly preferably from 0.3 to 1.0.

It is preferred if the weight ratio of all complexing agents (a) contained in the agent to all free-radical scavengers (b) contained in the agent, i.e. the weight ratio (a)/(b), has a value of from 0.1 to 10, preferably from 0 .2 to 5, more preferably from 0.25 to 4.0, and very particularly preferably from 0.3 to 1.0.

Composition for lightening keratin fibers with oxidizing agent (c)

The combination of ingredients (a) and (b) shows its potential in agents for oxidative color change, in particular for lightening or bleaching hair. For this reason, the agent according to the invention contains at least one oxidizing agent (c) as the third component essential to the invention.

The person skilled in the art understands an oxidizing agent to be a substance or a compound which can oxidize other substances and is itself reduced in the process. Oxidizing agents can accept electrons while reducing agents donate electrons. Oxidizing agents customary in hair treatment can be selected from the group of inorganic and/or organic peroxo compounds. To achieve moderate whitening effects, hydrogen peroxide is the oxidizing agent of choice. As bleaching and bleaching agents, preferred agents are further characterized in that they contain hydrogen peroxide and/or one of its solid adducts with organic or inorganic compounds. However, if stronger lightening or bleaching is desired, hydrogen peroxide is used together with stronger oxidizing agents such as persulphates (sodium persulphate, potassium persulphate or ammonium persulphate).

In a particularly preferred embodiment, an agent according to the invention is characterized in that it

(c) contains at least one oxidizing agent from the group consisting of hydrogen peroxide, ammonium peroxodisulphate, potassium peroxodisulphate and sodium peroxodisulphate.

Within the scope of this embodiment, a composition for the oxidative color change of keratin fibers, in particular human hair, contained in a cosmetic carrier is therefore particularly preferred

(b) at least one amino acid, and

(c) at least one oxidizing agent from the group consisting of hydrogen peroxide, ammonium peroxodisulphate, potassium peroxodisulphate and sodium peroxodisulphate.

(b) at least one protein hydrolyzate, and

(b) at least one radical scavenger, and

(c) at least one oxidizing agent from the group consisting of hydrogen peroxide, ammonium peroxodisulphate, potassium peroxodisulphate and sodium peroxodisulphate. Ammonium peroxodisulphate, which can alternatively also be referred to as ammonium persulphate, is understood as meaning the persulphate with the molecular formula (NH4)2S2Os.

Potassium peroxodisulfate, which can alternatively also be referred to as potassium persulfate, means the persulfate with the molecular formula K2S2O8.

Sodium peroxodisulphate, which can alternatively also be referred to as sodium persulphate, means the persulphate with the empirical formula Na2S2Os.

In the context of a particularly preferred embodiment, an agent according to the invention is characterized in that it contains

(c1) hydrogen peroxide and

(c2) at least one persulphate from the group consisting of ammonium persulphate, potassium persulphate and sodium persulphate.

In another preferred embodiment, hydrogen peroxide itself is used as an aqueous solution. The concentration of a hydrogen peroxide solution in the agent according to the invention is determined on the one hand by the legal requirements and on the other hand by the desired effect; preferably 3 to 12% by weight solutions in water are used. Agents preferred according to the invention of the first subject matter of the invention are characterized in that, based on the total weight of the agent, they contain (a) 0.1 to 12.0% by weight, preferably 0.5 to 10.5% by weight, more preferably 1 0 to 8.5% by weight, more preferably from 1.5 to 7.0% by weight and very particularly preferably 1.5 to 6.0% by weight, of hydrogen peroxide.

In a particularly preferred embodiment, a composition according to the invention is characterized in that it contains (c) 0.1 to 12.0% by weight, preferably 0.5 to 10.5% by weight, based on the total weight of the composition preferably 1.0 to 8.5% by weight, even more preferably from 1.5 to 7.0% by weight and very particularly preferably 1.5 to 6.0% by weight hydrogen peroxide.

The persulfate or persulfates are also preferably used in specific quantity ranges in the agent according to the invention. It has been found to be preferred if the agent - based on the total weight of the agent - (c) one or more persulfates from the group consisting of ammonium peroxodisulfate, potassium peroxodisulfate and sodium peroxodisulfate in a total amount of 2.0 to 40.0% by weight, preferably from 4.0 to 30.0% by weight, more preferably from 6.0 to 20.0% by weight and most particularly from 8.0 to 15.0% by weight.

Within the scope of a particularly preferred embodiment is an agent according to the invention characterized in that - based on the total weight of the agent - (c) one or more persulfates from the group consisting of ammonium peroxodisulfate, potassium peroxodisulfate and sodium peroxodisulfate in a total amount of 2.0 to 40.0% by weight, preferably 4.0 to 30.0% by weight, more preferably from 6.0 to 20.0% by weight and most preferably from 8.0 to 15.0% by weight.

(a) at least one complexing agent of the general formula (I), preferably of the formula (Ia), (Ib), (Ic) and/or (Id), and

(b) at least one amino acid and/or a protein hydrolyzate, and

(c1) 1.5 to 6.0% by weight hydrogen peroxide, and

(c2) one or more persulphates from the group consisting of ammonium peroxodisulphate, potassium peroxodisulphate and sodium peroxodisulphate in a total amount of 8.0 to 15.0% by weight, all amounts in % by weight being based on the total weight of the composition.

alkalizing agents

As already described above, the agent according to the first subject matter of the invention is a ready-to-use agent for lightening or bleaching keratin fibers. In order to achieve an adequate bleaching effect, such agents are usually made alkaline to strongly alkaline. Such high pH values are necessary in order to ensure that the outer cuticle layer (cuticle) opens and thus allows penetration of the active species (hydrogen peroxide and persulphates) into the hair.

For this reason it has turned out to be very particularly preferred if the agent according to the invention additionally contains at least one alkalizing agent.

Within the scope of a further preferred embodiment, an agent according to the invention is characterized in that it contains at least one alkalizing agent.

Preferred alkalizing agents are, for example, ammonia, alkanolamines, basic amino acids, and inorganic alkalizing agents such as (earth) alkali metal hydroxides (earth) - alkali metal metasilicates (earth) alkali metal silicates (earth) alkali metal phosphates and (earth) - alkali metal hydrogen phosphates. Lithium, sodium and/or potassium preferably serve as metal ions. Preferred alkalizing agents are (earth) alkali metal metasilicates and (earth) alkali metal silicates. Suitable inorganic alkalizing agents are preferably selected from sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide, sodium phosphate, potassium phosphate, sodium silicate, potassium silicate, magnesium silicate, sodium carbonate and potassium carbonate. Sodium hydroxide and/or potassium hydroxide are particularly preferred.

Alkanolamines used as alkalizing agents are preferably selected from primary, secondary or tertiary amines with a C2-Ce-alkyl skeleton which carries at least one hydroxyl group. Particularly preferred alkanolamines are selected from the group formed from 2-aminoethan-1-ol (monoethanolamine), 3-aminopropan-1-ol, 4-aminobutan-1-ol, 5-aminopentan-1-ol, 1 -aminopropan-2-ol (monoisopropanolamine), 1-aminobutan-2-ol, 1-aminopentan-2-ol, 1-aminopentan-3-ol, 1-aminopentan-4-ol, 2-amino-2-methyl- propanol, 2-amino-2-methylbutanol, 3-amino-2-methylpropan-1-ol, 1-amino-2-methylpropan-2-ol, 3-aminopropan-1,2-diol, 2-amino-2- methylpropane-1,3-diol, 2-amino-2-ethyl-1,3-propanediol, N,N-dimethylethanolamine, methylglucamine, triethanolamine, diethanolamine and triisopropanolamine. Particularly preferred alkanolamines are monoethanolamine, 2-amino-2-methylpropanol and triethanolamine.

Basic amino acids as alkalizing agents are preferably selected from the group consisting of L-arginine, D-arginine, D/L-arginine, L-lysine, D-lysine, D/L-lysine, L-ornithine, D-ornithine , D/L-ornithine, L-histidine, D-histidine and/or D/L-histidine. L-arginine, D-arginine and/or D/L-arginine are particularly preferably used as an alkalizing agent. In the context of this embodiment, a basic amino acid is used as ingredient (b) which both—in combination with the complexing agent (a)—improves the lightening performance and is also responsible for setting the particularly suitable alkaline pH values.

Particularly suitable agents according to the invention have a pH in the range from 7.5 to 11.5, preferably from 8.0 to 11.5, more preferably from 8.5 to 11.5 and very particularly preferably from 9.0 to 11.0. The pH values for the purposes of the present invention are pH values measured at a temperature of 22.degree. The pH value can be measured, for example, with a commercially available glass electrode.

In a particularly preferred embodiment, an agent according to the invention is characterized in that it contains water and has a pH of 7.5 to 11.5, preferably 8.0 to 11.5, more preferably 8.5 to 11 .5 and very particularly preferably from 9.0 to 11.0.

No HEPP or EDTA

The aim of the present application is in particular to dispense with the non-biodegradable complexing agents HEDP and EDTA. For this reason, the agents according to the invention preferably contain these two complexing agents in particularly small amounts. are very particularly preferred the funds devoid of these two substances. Most preferably, the agent is also essentially free of the salts of HEDP and EDTA.

In a further preferred embodiment, an agent according to the invention is characterized in that the total content of the substances contained in the agent from the group consisting of etidronic acid and the salts of etidronic acid is less than 0.2% by weight, based on the total weight of the agent below 0.1% by weight, more preferably below 0.05% by weight and very particularly preferably below 0.001% by weight.

In a further preferred embodiment, an agent according to the invention is characterized in that the total content of the substances contained in the agent from the group consisting of EDTA and the salts of EDTA is less than 0.2% by weight, based on the total weight of the agent below 0.1% by weight, more preferably below 0.05% by weight and very particularly preferably below 0.001% by weight

Etidronic acid is alternatively also referred to as hydroxyethane-1,1-diphosphonic acid and has the CAS number 2809-21-4.

EDTA is alternatively referred to as ethylenediamine tetraacetate and has CAS numbers 6381-92-6 and 139-33-3 (anhydrous). other ingredients

In addition to the ingredients (a), (b) and (c) that are essential to the invention—and optionally the alkalizing agents—the agent according to the invention can also contain other active ingredients and auxiliaries as optional ingredients. These are described below.

The agents can also contain other active ingredients, auxiliaries and additives, such as solvents, fatty components such as Cs-Cso fatty alcohols, Cs-Cso fatty acid triglycerides, Cs-Cso fatty acid monoglycerides, Cs-Cso- fatty acid diglycerides and/or hydrocarbons; nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric and/or zwitterionic surfactants, polymers; structurants such as glucose, maleic acid and lactic acid, hair conditioning compounds such as phospholipids, e.g. lecithin and cephalins; perfume oils, dimethylisosorbide and cyclodextrins; fiber structure-improving active ingredients, in particular mono-, di- and oligosaccharides such as glucose, galactose, fructose, fructose and lactose; dyes for coloring the agent; anti-dandruff agents such as Piroctone Olamine, Zinc Omadine and Climbazole; vegetable oils; sunscreens and UV blockers; Active ingredients such as panthenol, pantothenic acid, pantolactone, allantoin, pyrrolidinone carboxylic acids and their salts, and bisabolol; Polyphenols, in particular hydroxycinnamic acids, 6,7-dihydroxycoumarins, hydroxybenzoic acids, plant extracts; fats and waxes such as fatty alcohols, beeswax, montan wax and paraffins; Swelling and penetrating substances such as glycerol, propylene glycol monoethyl ether, carbonates, hydrogen carbonates, guanidines, ureas and primary, secondary and tertiary phosphates; opacifiers such as latex, styrene/PVP and styrene/acrylamide copolymers; pearlescent agents such as ethylene glycol mono- and distearate and PEG-3 distearate; Oxidation dye precursors, direct dyes and propellants such as propane-butane mixtures, N2O, dimethyl ether, CO2 and air.

The person skilled in the art will select these further substances in accordance with the desired properties of the agents. With regard to other optional components and the amounts of these components used, express reference is made to the relevant handbooks known to those skilled in the art. The additional active ingredients and auxiliaries are preferably used in the preparations according to the invention in amounts of 0.0001 to 25% by weight, in particular 0.0005 to 15% by weight, based on the total weight of the respective composition.

Process oxidative color change of keratin fibers

As already described above, the agent of the first subject of the invention is an agent for the oxidative color change of keratin fibers. The agent is very particularly preferably a lightening or bleaching agent. This lightening bleaching agent is a ready-to-use agent. Accordingly, the agents can be used in a process for oxidative color change, in particular for lightening the keratin fibers.

A second subject of the present invention is a method for oxidatively changing the color of keratin fibers, in particular human hair, in which an agent, as disclosed in detail in the description of the first subject of the invention, is applied to the keratin fibers and rinsed out again after an exposure time.

Oxidizing agents such as hydrogen oxide and persulfates are highly reactive compounds that have only limited stability, especially in an alkaline environment. For this reason, the ready-to-use bleaching agent is usually produced shortly before use by mixing two or more separately packaged preparations.

The oxidizing agent (c) and the alkalizing agent are usually made up separately from one another. Various types of packaging are conceivable for the complexing agent (a) and the activators (b).

For example, complexing agent (a) and activator (b) can be formulated together with one or more persulfates and separately from the hydrogen peroxide. This embodiment is particularly preferred when only two different preparations are to be mixed together to produce the ready-to-use agent. In a preferred embodiment, a method for the oxidative color change of keratin fibers is characterized in that at least two separately packaged preparations (A) and (B) are mixed to form an application mixture, which is applied to the fibers and rinsed off again after an exposure time, wherein

- the preparation (A) contains hydrogen peroxide (c1), and

- the preparation (B) contains

- at least one complexing agent (a) of general formula (I), and

- at least one activator (b), and

- at least one persulfate (c2) from the group consisting of ammonium peroxodisulfate, potassium peroxodisulfate and sodium peroxodisulfate, the complexing agent (a) and the activator (b) having already been disclosed in detail in the description of the first subject of the invention.

The preparations (A) and (B) can be mixed either with each other or with other separately packaged preparations immediately before use to form an application mixture.

If three different preparations are to be mixed together to produce the ready-to-use agent, it may be preferable to provide the first oxidizing agent hydrogen peroxide (c1) separately in a first preparation (A), and the persulfates (c2) as the second oxidizing agent separately in a second To provide preparation (B) and furthermore to provide a third preparation (C) which comprises complexing agent (a) and activator (b).

In a further preferred embodiment, a method for the oxidative color change of keratinic fibers is characterized in that at least three separately packaged preparations (A) and (B) and (C) are mixed to form an application mixture, which is applied to the fibers and after an exposure time is rinsed off again, whereby

- the preparation (A) contains hydrogen peroxide (c1), and

- the preparation (B) contains at least one persulfate (c2) from the group consisting of ammonium peroxodisulfate, potassium peroxodisulfate and sodium peroxodisulfate, and

- the preparation (C) contains at least one complexing agent (a) of the general formula (I) and at least one activator (b), the complexing agent (a) and the activator (b) already being disclosed in detail in the description of the first subject of the invention became.

The preparations (B) containing the persulfates are preferably in powder form. Powders made from solid components with different particle sizes can be used here. It can usually be preferred if the powders have a grain size that is as homogeneous as possible in particular to facilitate uniform dispersion or dissolution of the powders in the preparations (B).

Furthermore, the preparations (B) can also contain the persulfates in a solid cosmetic carrier. A solid cosmetic carrier can contain salts of silicic acid, in particular salts of silicates and metasilicates with ammonium, alkali metals and alkaline earth metals. In particular, metasilicates, which are characterized by the formula (SiO2)n(M2Ö) _m , where M is an ammonium ion, an alkali metal or half the stoichiometry equivalent of an alkaline earth metal, by the ratio between n and m of <1 and are characterized as chain-like polymeric structures of the Anions [SiCh] ^2- can be used with preference. Sodium metasilicate of the formula [Na2SiO3]~ is particularly preferred. Equally preferred are those silicates which are formed from a silicate of the formula (SiO2)n(Na2O)m(K2Ö)p, where n is a positive rational number and m and p are independently a positive rational number or 0, with the proviso that at least one of the parameters m or p is different from 0 and the ratio between n and the sum of m and p is between 2:1 and 4:1.

Furthermore, the solid preparations (B) can contain so-called flow aids, which are intended to prevent the powder components from clumping or caking. Such flow aids are preferably water-insoluble, hydrophobic or moisture-absorbing powders of kieselguhr, pyrogenic silica, calcium phosphate, calcium silicates, aluminum oxide, magnesium oxide, magnesium carbonate, zinc oxide, stearates, fatty amines and the like.

Finally, preparations (B) can additionally contain a dedusting agent, which prevents the formation of dust from the pulverulent components. In particular, inert oils can be used for this purpose. The solid cosmetic carriers preferably contain ester oils or mineral oils, preferably hydrocarbon oils, such as liquid paraffin oil, as dust-removing agents.

The ready-to-use agents are prepared immediately before use on the hair by mixing the two preparations (A) and (B) or by mixing the three preparations (A) and (B) and (C). In the case of ready-to-use agents that are mixed from more than two preparations to form a ready-to-use mixture, it may be irrelevant whether two preparations are first mixed together and then the third preparation is added and mixed in, or whether all preparations are brought together and then mixed. Mixing can be accomplished by stirring in a bowl or beaker, or by shaking in a sealable container.

The two preparations (A) and (B) can be mixed, for example, in a ratio of 1:5 to 5:1, preferably 1:3 to 3:1 and particularly 1:2 to 2:1. Become three preparations If (A), (B) and (C) are mixed together, different mixing ratios are also possible, which can range, for example, from 1:1:1 to 3:1:1 to 1:3:1 to 1:1:3.

The term "immediately" is to be understood as a period of a few seconds to an hour, preferably up to 30 minutes, in particular up to 15 minutes.

The preparations (A), (B) and optionally (C) are used in a method for lightening keratin fibers, in particular human hair, in which the agent is applied to the keratin-containing fibers for an exposure time of 10 to 60 minutes on the Leave the fiber and then rinse it out with water or wash it out with a shampoo.

The exposure time of the ready-to-use lightening agent is preferably 10 to 60 minutes, in particular 15 to 50 minutes, particularly preferably 20 to 45 minutes. While the agent is acting on the fiber, it can be advantageous to support the lightening process by applying little heat. The heat can be supplied by an external heat source, such as with the aid of a warm air blower, and also, particularly in the case of hair lightening on living subjects, by the subject's body temperature. With the latter option, the area to be lightened is usually covered with a hood. An exposure phase at room temperature is preferred. After the exposure time has ended, the remaining lightening preparation is rinsed out of the hair with water or a cleaning agent. In particular, commercial shampoo can be used as the cleaning agent, in which case the cleaning agent can be dispensed with and the rinsing process can be carried out with tap water if the lightening agent has a carrier with a high surfactant content.

The preferred embodiments of the agent described above also apply mutatis mutandis to the method.

examples

1. Preparation of the ready-to-use lightening agent by mixing three preparations

(A), (B) and (C)

The following preparations were produced (all data in % by weight unless otherwise stated). purchased under the trade name Natrlguest E30 from Innospec Limited 2. Application to strands of hair

Hair tresses (Kerling, Euro natural hair 4-0) were colorimetrically measured (Datacolor Spectraflash SF 450) (L=21.69, a=3.79, b=4.36), preshampooed and dried.

To produce the ready-to-use lightening or bleaching agent, 60 g of preparation (A) were mixed with 20 g of preparation (B) and 60 g of preparation (C). The application mixture obtained in this way was applied to the strands of hair, left there for 45 minutes and then rinsed out again with water. The hair tresses were then measured colorimetrically again. Each application mixture was applied to two strands of hair.

The higher the AE value, the greater the color shift of the strands compared to untreated hair. The dE value used for the assessment results from the measured L*a*b* color values as follows: dE = [ (Li - Lo) ² + (a> - a ₀ ) ² + (bi - bo)] ^{1 /2}

Lo, ao and bo = measurements of the strand before bleaching

Li, ai and bi = measurements of the strand after bleaching

The greater the AC value, the greater the difference in chroma compared to untreated hair, where the chroma is calculated as C=(a ² +b ² ) ^1/2 .

In the strands of hair that were bleached using the preparations (C2), (C3) and (C4), particularly high AE values and increased AC values could be measured, i.e. with these formulations the color shift or color change compared to the exit hair largest.

3. Measurement of the temperature profile during the brightening Strands with a high metal content were used to measure the temperatures occurring during bleaching. To create this hair, strands of hair were treated as follows:

Strands of hair (Kerling, European natural hair white, 6-0) were pre-shampooed and then pre-bleached once with a commercially available bleaching agent. The pre-bleaching was done to increase the copper uptake in the hair. The pre-bleached strand was doped with copper:

For this purpose, 1 g strand was dipped into 20 g of a copper solution (50 ppm copper in water, 16.8° dH) and left there for 1 minute. Then the tress was taken out of the solution, squeezed out slightly and dried at room temperature. This dipping process was repeated three times for each tress.

Thereafter, the copper content of each strand of hair was determined analytically. The determination was made after mineralization of the sample (one strand each) in the microwave digestion system with HNO3/HCL using atomic emission spectrometry (ICP-OES). The average was formed from 12 measurements. The average copper content of each strand of hair was 1900 mg/kg.

The application mixtures described under point 2 were applied to the hair treated in this way. The strands were fitted with a Pt100 sensor and wrapped in aluminum foil. The reaction temperature was measured and documented after an exposure time of 2, 4, 6, 8, 10, 12 and 14 minutes.

If the reaction temperature measured on the hair exceeded 40 °C, the corresponding temperature profile was classified as unacceptable. Recipes that show an unacceptable temperature profile are out of the question for use on the living end of the sample. The application mixtures (A) + (B) + (C2) and (A) + (B) + (C4) are particularly well suited for use on the human head, as they both improve the lightening performance and optimize it of the temperature profile occurring during the application.

4. further formulation examples

Production of the ready-to-use lightening agent by mixing two preparations (A) and (B)

The ready-to-use bleaching agents were prepared by mixing preparation (A) with one of each of preparations (B1) to (B8) in a proportion of 1:1.

5. Brightening colorants made by mixing two formulations (A) and (B).

Preparation (A) was mixed with preparation (B) in a ratio of 1:1 in each case.

Claims

patent claims

1 . Containing agent for the oxidative color change of keratin fibers, in particular human hair

(a) at least one complexing agent of the general formula (I) whereby

R1, R2 independently for a carboxyl group or for a physiologically acceptable salt thereof, a hydrogen atom, a Ci-Ce-alkyl group, a hydroxy-C2-Ce-alkyl group, a hydroxy group, a carboxy-Ci-Ce-alkyl group or for a physiologically acceptable salt thereof,

(b) at least one activator from the group consisting of amino acids, protein hydrolyzates and

radical scavengers and

(c) at least one oxidizing agent.

2. Means according to claim 1, characterized in that there is at least one complexing agent

(a) of the general formula (I), wherein

3. Agent according to one of claims 1 to 2, characterized in that it contains at least one complexing agent (a) of the general formula (I), wherein 46

R3, R4 independently represent a hydrogen atom, a carboxy-Ci-Ce-alkyl group or a physiologically tolerable salt thereof, particularly preferably a hydrogen atom. Agent according to one of Claims 1 to 3, characterized in that it contains at least one complexing agent (a) of the general formula (I), where m is the number 0 or 1, preferably the number 0. Agent according to one of claims 1 to 4, characterized in that - based on the total weight of the agent - one or more complexing agents (a) of the formula (I) in a total amount of 0.05 to 10.0 wt .-%, preferably from 0.05 to 7.5% by weight, more preferably from 0.05 to 2.5% by weight and very particularly preferably from 0.05 to 1.5% by weight. Agent according to one of Claims 1 to 5, characterized in that it contains at least one activator (b) from the group of amino acids, preferably from the group of glycine, lysine, arginine, histidine, asparagine, glutamine, cysteine, methionine, tryptophan, serine , alanine, aspartic acid, glutamic acid, isoleucine, leucine, phenylalanine, proline, threonine, tyrosine and valine, very particularly preferably from the group consisting of glycine and lysine. Agent according to Claim 6, characterized in that - based on the total weight of the agent - one or more amino acids (b) in a total amount of 0.1 to 10.0% by weight, preferably 0.1 to 5 0% by weight, more preferably from 0.1 to 2.5% by weight and very particularly preferably from 0.1 to 1.0% by weight. Agent according to one of Claims 1 to 7, characterized in that it contains at least one activator (b) from the group of protein hydrolysates, preferably from the group of vegetable protein hydrolysates, protein hydrolysates of elastin, collagen, keratin, silk, milk protein , soy, almond, pea, moringa, potato and wheat protein hydrolysates. Agent according to Claim 8, characterized in that - based on the total weight of the agent - one or more protein hydrolyzates (b) in a total amount of 0.1 to 10.0% by weight, preferably 0.1 to 5 0% by weight, more preferably from 0.1 to 2.5% by weight and very particularly preferably from 0.1 to 1.0% by weight. Agent according to one of Claims 1 to 9, characterized in that it contains at least one activator (b) from the group of free-radical scavengers, preferably from the group of unsaturated organic compounds, antioxidants, quinones and thiols. Agent according to one of Claims 1 to 10, characterized in that it contains at least one activator (b) of the general formula (II). whereby

R6, R7 independently represent a saturated or unsaturated C11-C29 alkyl group, with the proviso that at least one of R6 and R7 represents an unsaturated Cn-C29 alkyl group. Agent according to Claim 11, characterized in that it contains at least one activator (b) of the general formula (II), where at least one of the radicals R6 and/or R7 is an at least monounsaturated cis-C2i-alkyl group, particularly preferably at least one doubly unsaturated cis-C2i-alkyl group and very particularly preferably an at least tri-unsaturated cis-C2i-alkyl group. Agent according to one of claims 10 to 12, characterized in that - based on the total weight of the agent - one or more radical scavengers (b) in a total amount of 0.01 to 10.0 wt .-%, preferably 0.25 to 7.0% by weight, more preferably from 0.25 to 6.0% by weight and most preferably from 0.25 to 2.5% by weight. Agent according to one of Claims 1 to 13, characterized in that the weight ratio of all complexing agents (a) contained in the agent to all activators (b) contained in the agent, i.e. the weight ratio (a)/(b), has a value of 0 1 to 10, preferably from 0.2 to 5, more preferably from 0.25 to 4.0, and very particularly preferably from 0.3 to 1.0. Agent according to one of claims 1 to 14, characterized in that it (c) contains at least one oxidizing agent from the group consisting of hydrogen peroxide, ammonium peroxodisulphate, potassium peroxodisulphate and sodium peroxodisulphate. Agent according to one of Claims 1 to 15, characterized in that it contains water and a pH of 7.5 to 11.5, preferably 8.0 to 11.5, more preferably 8.5 to 11.5 and very particularly preferably from 9.0 to 11.0. Process for the oxidative color change of keratin fibers, in particular human hair, in which an agent according to any one of claims 1 to 16 is applied to the keratin fibers and rinsed out again after an exposure time.