FR3067598A1 - METHOD FOR COLORING KERATIN FIBERS USING AT LEAST ONE PROTECTED FLUORESCENT, THIOL OR THIOL DYE AND AT LEAST ONE ACTIVATOR COMPRISING A REDUCER AND LESS THAN TWO DIFFERENT ALKALI AGENTS - Google Patents

Abstract

The present invention relates to a process for dyeing and / or lightening keratinous fibers, in particular human keratinous fibers such as the hair, using a) one or more direct dyes fluorescent disulfides, thiols or protected thiols and b) a an activating agent comprising i) at least one reducing agent and ii) at least two alkaline agents different from each other. The present invention further relates to a cosmetic composition comprising the dyes a) as defined above, i) at least one reducing agent, and ii) at least two alkaline agents different from each other, as well as on a multi-compartment device containing ingredients a) and b). The combination of the activating agent (s) b) and the direct fluorescent dye (s), disulfide (s), thiol (s), or protected thiol (s) (s) ) a) makes it possible in particular to obtain very chromatic and particularly visible colorations having good coloring properties, especially in terms of chromaticity, intensity, and color rise.

Description

The present invention relates to a process for dyeing and / or lightening keratin fibers, in particular human keratin fibers such as the hair, using a) one or more fluorescent direct dyes disulfides, thiols or thiols protected and b ) an activating agent comprising i) at least one reducing agent and ii) at least two different alkaline agents from one another.

The present invention further relates to a cosmetic composition comprising the dyes a) as defined above, i) at least one reducing agent, and ii) at least two alkaline agents different from each other, as well as a device with several compartments containing the ingredients a) and b).

The combination of activating agent (s) b) and fluorescent direct dye (s) disulfide (s), thiol (s), or protected thiol (s) ) a) in particular makes it possible to obtain very chromatic and particularly visible colorings having good coloring properties, in particular in terms of chromaticity, intensity, and color enhancement.

Process for coloring keratin fibers using at least one disulfide, thiol or thiol protected fluorescent dye and at least one activator comprising a reducing agent and at least two different alkaline agents

The present invention relates to a process for coloring and / or lightening human keratin fibers such as the hair, using a) one or more fluorescent direct dyes disulfides, thiols or protected thiols and b) an activating agent comprising i) to at least one reducing agent and ii) at least two different alkaline agents.

The present invention further relates to a cosmetic composition comprising the dyes a) as defined above, i) at least one reducing agent, and ii) at least two alkaline agents different from each other, as well as a device with several compartments containing the ingredients a) and b).

Many people have long sought to change the color of their hair, and in particular to mask their gray hair.

It is notably known to dye keratin fibers, in particular human keratin fibers, with dye compositions containing oxidation dye precursors, generally called oxidation bases. These oxidation bases are colorless or weakly colored compounds which, associated with oxidizing products, can give rise, through an oxidative condensation process, to colored compounds.

The shades obtained with these oxidation bases can be modified by associating them with couplers or color modifiers. The variety of molecules involved in the oxidation bases and couplers provides a rich palette of colors.

Another well-known method consists in obtaining so-called semipermanent or fleeting dyes by applying to the keratin fibers direct dyes which are colored and coloring molecules having an affinity for said fibers.

The direct dyes conventionally used are chosen from benzene, anthraquinone, nitropyridine, azo, xanthene, acridine, azine or triarylmethane direct dyes. Chemical species can be non-ionic, anionic (acid dyes) or cationic (basic dyes). Direct dyes can also be natural dyes.

Conventional direct dyeing methods consist in applying to the keratin fibers, dye compositions comprising direct dyes. After application, a pause time is observed in order to allow the coloring molecules to penetrate by diffusion inside the fibers. At the end of the process, the fibers are rinsed.

Unlike oxidative stains, these direct staining processes tend to better protect the integrity of keratin materials. The resulting colorings are generally chromatic but are however only semi-temporary. The nature of the interactions which bind the direct dyes to the keratin fibers, as well as their desorption from the surface and / or from the core of the fiber are responsible for their low persistence on the fiber.

In applications EP 1 647 580, WO 2005/097051, EP 2 004 759, EP 2 075 289, WO 2007/110541, WO 2007/110540, WO 2007/110539, WO 2007/110538, WO 2007/110537, WO 2007 / 110536, WO 2007/110535, WO 2007/110534, WO 2007/110533, WO 2007/110532, WO 2007/110531, EP 2 070 988, WO 2009/040354, and WO 2009/034059, there are described direct dyes with disulfide, thiol or protected thiol function for coloring the hair. The colors obtained are not always sufficiently satisfactory, in particular in terms of intensity of coloration, rise in color, selectivity of the color between the root and the tip, and / or chromaticity of the color.

Another aim of these inventions is also to provide new systems for coloring dark keratin materials, making it possible to lighten them, even without the use of chemical oxidants, making it possible to obtain improved colorings, in particular in terms of toughness vis-à-vis external agents, uniformity of coloring (low selectivity between the root and tip of keratin fibers), chromaticity, intensity, and / or which do not alter the cosmetic properties of keratin fibers.

These colors are not always sufficiently chromatic, and the color does not always rise sufficiently well and / or are not always sufficiently tenacious in the face of external agents such as light or perspiration. Furthermore, in the case of an optical lightening of the keratin fibers, in particular dark, the systems of the prior art are not always satisfactory in terms of the visibility of this lightening.

Thus, there is a real need to implement direct dyeing processes for keratin fibers, in particular human fibers such as the hair, which do not have the drawbacks mentioned above, ie which in particular make it possible to produce dyes exhibiting good properties, in particular in terms of chromaticity, power, intensity, shine and selectivity, color rise, and / or which are persistent especially in shampoos, in particular on light keratin fibers, or which in particular make it possible to conduct to visible optical lightening, in particular on dark keratin fibers.

Another object of the present invention is therefore to be able to color and / or lighten human keratin fibers such as the hair, preferably only with direct dyes a) as defined above without necessarily having to add an oxidizing agent.

The Applicant has surprisingly discovered that a process for coloring keratin fibers, in particular human fibers such as the hair, using

a) one or more disulfide fluorescent dyes, thiols or thiols protected and b) an activating agent comprising at least one reducing agent and at least two different alkaline agents, made it possible to achieve the objectives set out above .

Thus the main object of the present invention relates to a process for dyeing keratin fibers, in particular human fibers such as the hair, consisting in applying to said fibers:

a) one or more disulfide fluorescent direct dyes, thiols or protected thiols;

b) one or more activating agents comprising:

i) at least one reducing agent; and ii) at least two different alkaline agents from each other;

it being understood that a) the disulfide fluorescent direct dye (s), thiols or thiols protected, and b) the activating agent (s) are applied to said keratin fibers jointly or sequentially.

Another object of the invention is a cosmetic composition comprising:

a) one or more disulfide fluorescent direct dyes, thiols or protected thiols;

b) one or more activating agents comprising:

i) at least one reducing agent; and ii) at least two different alkaline agents from each other;

c) optionally the pH of said composition is inclusive between 7 and 12, preferably between 8 and 11, more preferably between 8.5 and 10.5.

The combination of activating agent (s) b) and fluorescent direct dye (s) disulfide (s), thiol (s), or protected thiol (s) ) a) in particular makes it possible to obtain very chromatic and particularly visible colorings having good coloring properties, in particular in terms of persistence, power, intensity, shine and / or selectivity, in particular on light hair; preferably making it possible to obtain colorings having good coloring properties, in particular in terms of chromaticity, intensity, and rise in color. The combination according to the invention also makes it possible to lighten the dark keratin fibers visibly. In addition, under UV radiation, the phenomenon of fluorescence associated with color effects is particularly marked and aesthetic,

Furthermore, the colorings obtained by the process and the composition according to the invention resist well to the various aggressions that the hair can undergo, such as light, bad weather, washing, perspiration. They are in particular persistent in shampoos, and in particular after at least 3 shampoos.

On the other hand, the lightening obtained in particular on dark hair by the process and the composition according to the invention resist well to the various aggressions that the hair can undergo, such as light, bad weather, washing, sweating.

The present invention also relates to a device with several compartment (s) comprising a first compartment containing a) one or more fluorescent dye (s) disulfide (s), thiol (s) or thiol (s) protected (s) ), as defined above and in one or more other compartments containing, together or separately, i) one or more reducing agent (s), ii) two or more alkaline agent (s) ( s) different from each other.

The present invention also relates to the use of the activating agent b) associated with the dye (s) a) as defined above for the coloring and / or brightening of light or dark keratin fibers, and in particular for improving the rise in color, intensity and / or chromaticity.

The process and the composition of the invention make it possible to obtain, with the fluorescent dyes of the invention, a lightening of the dark keratin fibers. In particular, the process of the invention makes it possible to obtain a lightening of keratin fibers such as the hair, chromatic, with a good rise in color, and / or tenacious to shampoos, to common aggressions (sun, perspiration), and to the others. hair treatments without degrading the keratin fiber.

Within the meaning of the invention, the term “dark fiberkeratin” is understood to mean that which has a luminance L * encrypted in the C.I.E. system. L * a * b *, less than or equal to 45 and preferably less than or equal to 40, knowing moreover that L * = 0 is equivalent to black and L * = 100 to white.

For the purposes of the invention, the term "dark hair" means hair whose pitch is less than or equal to 6 (dark blonde) and preferably less than or equal to 4 (chestnut).

The lightening of the hair is evaluated by the "height of tone" which characterizes the degree or the level of lightening. The concept "tone" is based on the European classification of natural shades, a tone separating each shade from the one that immediately follows or precedes it. This definition and classification of natural shades is well known to hair professionals and published in the book "Science of hair treatments" by Charles ZVIAK 1988, Ed. Masson, p. 215 and 278.

The pitch of the tone ranges from 1 (black) to 10 (light light blonde), a unit corresponding to a tone; the higher the number, the lighter the shade.

An artificially colored keratin fiber is a fiber whose color has been modified by a coloring treatment, for example a coloring with direct dyes or oxidation dyes.

The lightening properties of the composition of the invention after application to dark keratinous keratin fibers, for example chestnut fibers, can be evaluated by reflectance:

- The fibers are irradiated with visible light in the wavelength range from 400 to 700 nanometers;

- The reflectance curves are then compared as a function of the wavelength, of the fibers treated with the composition of the invention and of the untreated fibers;

- the curve corresponding to the treated fibers must show a reflectance in the wavelength range from 450 to 700 nanometers greater than the curve corresponding to the untreated fibers;

This means that, in the wavelength range from 450 to 700 nanometers, there is at least one range where the reflectance curve corresponding to the treated fibers is greater than the reflectance curve corresponding to the untreated fibers. By superior is meant a difference of at least 0.05% reflectance, and preferably at least 0.1%. This does not prevent that it can exist in the wavelength range from 450 to 700 nanometers, at least one range where the reflectance curve corresponding to the treated fibers is superimposable, or less than the reflectance curve corresponding to the untreated hair.

Preferably, the wavelength where the difference is maximum between the reflectance curve of the treated hair and that of the untreated hair, lies in the wavelength range from 450 to 650 nanometers, and preferably in the wavelength range from 450 to 620 nanometers.

Other objects, characteristics, aspects and advantages of the invention will appear even more clearly on reading the description and the examples which follow.

Within the meaning of the present invention, and unless a different indication is given:

• “direct dye” means, within the meaning of the present invention, natural and / or synthetic dyes, soluble in the cosmetic medium, different from the oxidation dyes which absorb color in the visible spectrum ie which appear visually colored; these are dyes which will diffuse superficially on the keratin fibers;

• by way of visual color and wavelength of absorption of the direct dyes of the invention associated with said color, the following colors may be mentioned "yellow" = At _max > 400 nm up to 440 nm including terminal, "orange "= At _max > 440 nm up to 490 nm terminal included," red "= At _max > 490 at up to 520 nm terminal included," purple to purple "= At _max > 520 nm and 560 nm terminal included," purple ”= At _max > 560 nm at 580 nm including terminal,“ blue ”= At _max > 580 nm up to 620 nm including terminal,“ blue-green ”= X _max > 620 nm up to 650 nm including terminal, and "green" At _max > 650 nm up to 780 nm including terminal; preferably the dyes the fluorescent dyes a) are yellow, orange or red;

• a direct fluorescent dye “with disulfide function” is a direct dye comprising one or more fluorescent chromophores as defined below, and comprising a disulfide bond: -SS- between two carbon atoms and which is preferably indirectly connected to ( x) chromophore (s) of the dye ie between the chromophores and the function -SS- is at least one methylene group;

• a “direct dye with a protected thiol function” is a direct dye comprising a chromophore, comprising a protected thiol function -SY where Y is a protective group known by a person skilled in the art, for example those described in the works “Protective Groups in Organic Synthesis ”, TW Greene, John Willey & Sons ed., NY, 1981, pp.193-217; “Protecting Groups”, P. Kocienski, Thieme, 3 ^rd ed., 2005, chap. 5; and Ullmann's Encyclopedia, "Peptide Synthesis", p. 4-5, 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 10.1002 / 14356007.a19 157; it being understood that said protected thiol function is preferably indirectly linked to the chromophore of the dye, ie between the chromophore and the -SY function, there is at least one methylene group;

• a “direct dye with a thiol function” is a direct dye comprising a chromophore, and comprising a thiol function -SY 'where Y' is i) a hydrogen atom; ii) an alkali metal; iii) an alkaline earth metal; iv) an ammonium group: N ⁺ R ^a R ^b R ⁹ R ^d or a phosphonium group: P ⁺ R ^a R ^b R ⁹ R ^d with R ^a , R ^b , R ⁹ and R ^d , identical or different, representing a hydrogen atom or a (Ci-C ₄ ) alkyl group preferably comprising a thiol function -SH it being understood that said thiol function is indirectly linked to the chromophore of the dye ie between the chromophore and the function -SY 'is at least one group methylene;

• a “fluorescent chromophore” is a radical resulting from a fluorescent dye, that is to say a radical resulting from a molecule absorbing the light in the visible field of the radiation visually perceptible by the man and which appear with l colored eyes ie absorbing light at an absorption wavelength λ _abs preferably inclusive between 300 and 700 nm; said chromophore is furthermore capable of re-emitting in the visible range at an emission wavelength 7 _em comprised greater than the absorption wavelength, preferably preferably 7 _em re-inclusive between 400 and 800 nm; the difference in the absorption and emission wavelength also called Stoke's shift or Stoke's shift is inclusive between 1 nm and 100 nm; more preferably the fluorescent chromophores are capable of absorbing at a wavelength _{λ abs} inclusive between 420 nm and 550 nm and of re-emitting in the visible at a wavelength 7 _em inclusive between 470 and 600 nm;

• a “chromophore” is said to be “quaternized cationic” or “carrier of a quaternized cationic group” if it comprises in its structure at least one permanent cationic charge consisting of at least one atom of quaternized nitrogen (ammonium) or quaternized phosphorus (phosphonium), preferably nitrogen;

• a group is said to "bear a quaternizable cationic group" when it comprises at least one tertiary amine or a tertiary phosphine at the end of a hydrocarbon chain, preferably C1-C10 alkyl, such as - (CR 'R ”) pN (R _a ) -R _b with R' and R” identical or different representing a hydrogen atom or a (Ci-C ₆ ) alkyl group; R _a and R _b , identical or different representing a (poly) (hydroxy) (Ci-C ₆ ) alkyl group or else R _a and R _b form together with the nitrogen atom which carry them a heterocycloalkyl group such as morpholino , piperidino or piperazino; and p representing an integer inclusive between 1 and 10; preferably R 'and R ”represent a hydrogen atom, R _a and R _b represent a (Ci-C ₄ ) alkyl group and p is between 2 and 5;

• the dyes according to the invention contain one or more colored and fluorescent chromophores as defined above, in particular they are capable of absorbing light at a wavelength _{λ abs} inclusive between 300 and 700 nm and of reemitting in the visible at a longer wavelength than the absorption wavelength, in particular 7 _em inclusive between 400 and 800 nm: the difference of the absorption and emission wavelength also called Stoke displacement or Stoke's shift is inclusive between 1 nm and 100 nm; more preferably the fluorescent dyes of the invention are dyes capable of absorbing at a wavelength λ _bs inclusive between 420 nm and 550 nm and re-emitting in the visible at a wavelength _{λ em} inclusive inclusive between 470 and 600 nm;

• the chromophores are said to be “different” when they differ in their chemical structure and can be chromophores from different families or from the same family provided that they have different chemical structures: for example, the chromophores can be chosen from the family of azo dyes but differ by the chemical structure of the radicals constituting it or by the respective position of these radicals;

• an “alkylene chain” represents a divalent C1-C20 acyclic hydrocarbon chain; particularly in Ci-C ₆ , more particularly in C1-C2 when the chain is linear; optionally substituted by one or more groups, identical or different, chosen from i) hydroxy, ii) (Ci-C ₂ ) alkoxy, iii) (poly) hydroxy (C ₂ -C ₄ ) alkoxy (di) (Ci-C ₂ ) (alkyl) amino, iv) R ^a -Z ^a -C (Z ^b ) -Z ^c -, and v) R ^a -Z ^a -S (O) t ~ Z ^c - with Z ^a , Z ^b , identical or different, representing an oxygen, sulfur, or NR ^a ', Z ^c is a bond, oxygen, sulfur, or NR ^a; R ^a , representing an alkali metal, a hydrogen atom, an alkyl group or else is absent if another part of the cationic molecule and R ^a 'representing a hydrogen atom or an alkyl group and t is 1 or 2; more particularly the groups iv) are chosen from carboxylate -C (O) O 'or -C (O) OMetal (Metal = alkali metal), carboxyl -C (O) -OH, guanidino H2H-C (NH ₂ ) -NH -, amidino H ₂ HC (NH ₂ ) -, (thio) ureo H ₂ NC (O) -NH- and H ₂ NC (S) -NH-, aminocarbonyl -C (O) -NRa ' ₂ or aminothiocarbonyl -C (S) -NRa '₂; carbamoyl Ra'-C (O) -NRa'- or thiocarbamoyl Ra'-C (S) -NRa'- with Ra ', identical or different, representing a hydrogen atom or a (Ci-C ₄ ) alkyl group;

• a “divalent saturated or unsaturated, optionally substituted CrC ₃₀ hydrocarbon chain, optionally” represents a hydrocarbon chain, particularly in C ₁ -C ₈ , optionally comprising one or more p double bonds, conjugated or not, particularly the hydrocarbon chain is saturated; said chain is optionally substituted by one or more, identical or different, groups chosen from i) hydroxy, ii) (Ci-C ₂ ) alkoxy, iii) (poly) hydroxy (C ₂ -C ₄ ) alkoxy (di) (Ci -C ₂ ) (alkyl) amino, iv) R ^a -Z ^a -C (Z ^b ) -Z ^c -, and v) R ^a -Z ^a -S (O) _t -Z ^c - with Z ^a , Z ^b, identical or different, representing an oxygen, sulfur, or NR ^a ', Z ^c is a bond, oxygen, sulfur, or NR ^a; R ^a , representing an alkali metal, a hydrogen atom, an alkyl group or else is absent if another part of the cationic molecule and R ^a 'representing a hydrogen atom or an alkyl group and t is 1 or 2; more particularly the groups iv) are chosen from carboxylate -C (O) O 'or -C (O) OMetal (Metal = alkali metal), carboxyl -C (O) -OH, guanidino H ₂ HC (NH ₂ ) -NH -, amidino H ₂ HC (NH ₂ ) -, (thio) ureo H ₂ NC (O) -NH- and H ₂ NC (S) -NH-, aminocarbonyl -C (O) -NR _a ' ₂ or aminothiocarbonyl - C (S) -NR _a '₂; carbamoyl R _a '-C (O) -NR _a ' - or thiocarbamoyl R _a '-C (S) -NR _a ' - with Ra ', identical or different, representing a hydrogen atom or a group (Ci-C ₄ ) alkyl;

• "fluorescent dyes" according to the present invention are to be distinguished from optical lightening agents. Optical lightening agents generally called "optical brighteners", or "brighteners", or "fluorescent brighteners" or "fluorescent brightening agents", or "fluorescent whitening agents or FWA", or "whiteners" or even "fluorescent whiteners" in English terminology , are compounds which are colorless to the eye, which do not color and are therefore not dyes since they do not absorb in visible light, but only absorb in Ultra-Violet (wavelength ranging from 200 at 400 nanometers) and transform the energy absorbed into fluorescent light of longer wavelength emitted in the visible part of the spectrum in blue. The color impression is then only generated by purely fluorescent light predominantly blue;

• “(hetero) aryl” means, in general, the aryl and heteroaryl groups;

• the “aryl” or “heteroaryl” radicals or the aryl or heteroaryl part of a radical can be substituted by at least one substituent carried by a carbon atom, chosen from:

- an alkyl radical Ci-C _6, preferably Ci-C _{4 alkyl} optionally substituted by one or more radicals chosen from the hydroxy, alkoxy C _2, (poly) hydroxyalkoxy, C ₂ -C ₄ acylamino amino substituted with two alkyl radicals, identical or different Ci-C _4, optionally bearing at least one hydroxyl group, or the two radicals to form, with the nitrogen atom to which they are attached, a heterocycle comprising 5 to 7 members, preferably 5 or 6 members, saturated or unsaturated optionally substituted optionally comprising another heteroatom identical or different from nitrogen;

- a halogen atom such as chlorine;

- a hydroxy or thiol group;

- an alkoxy radical Ci-C ₆ alkylthio or C _6;

- a C ₂ -C ₆ (poly) hydroxyalkoxy radical;

- an amino radical;

- a 5- or 6-membered heterocycloalkyl radical, preferably morpholino, piperazino, piperidino, or pyrolidino optionally substituted by a (Cr C ₄ ) alkyl radical, preferably methyl;

- a 5 or 6-membered heteroaryl radical, preferably imidazolyl, and optionally substituted by a (Ci-C ₄ ) alkyl radical, preferably methyl;

- an amino radical substituted by one or two alkyl radicals, identical or different Ci-C _{6 alkyl} optionally bearing at least:

i) a hydroxy group, ii) an amino group optionally substituted by one or two optionally substituted C1-C3 alkyl radicals, said alkyl radicals being able to form, with the nitrogen atom to which they are attached, a heterocycle comprising from 5 to 7 chain links, saturated or unsaturated optionally substituted optionally comprising at least one other heteroatom different or not from nitrogen, iii) a quaternary ammonium group -N ⁺ R'R "R"", Y 'for which R', R", R '”, Identical or different, represent a C1-C4 alkyl group; and Y 'represents an anionic counterion, iv) or a 5- or 6-membered heteroaryl radical optionally cationic, preferably imidazolium, and optionally substituted by a (Ci-C ₄ ) alkyl radical, preferably methyl;

- acylamino (-N (R) -C (O) -R ') wherein the radical R is a hydrogen atom, an alkyl Ci-C ₄ alkyl radical optionally bearing at least one hydroxyl group and the radical R 'is a C1-C2 alkyl radical;

- a carbamoyl radical ((R) ₂ NC (O) -) wherein the radicals R, identical or different, represent a hydrogen atom, an alkyl Ci-C ₄ alkyl radical optionally bearing at least one hydroxyl group;

> Alkylsulfonylamino radical (R'-S (O) ₂ -N (R) -) wherein the radical R represents a hydrogen atom, an alkyl Ci-C ₄ alkyl radical optionally bearing at least one hydroxy group and the radical R 'represents an alkyl radical Ci-C _4, a phenyl radical;

> An aminosulfonyl radical ((R) ₂ NS (O) ₂ -) wherein the radicals R, identical or different, represent a hydrogen atom, an alkyl Ci-C ₄ alkyl radical optionally bearing at least one hydroxyl group ,> a carboxylic radical in acid or salified form (preferably with an alkali metal or ammonium, substituted or not);

> a cyano group;

> a nitro or nitroso group;

> a polyhaloalkyl group, preferably trifluoromethyl;

• the cyclic or heterocyclic part of a non-aromatic radical can be substituted by at least one substituent chosen from groups:

- hydroxy;

- alkoxy -C ₄ (poly) hydroxyalkoxy, C ₂ -C ₄ alkyl;

- alkyl-C _4;

- alkylcarbonylamino (RC (O) -N (R ') -) wherein the radical R' is a hydrogen atom, an alkyl Ci-C ₄ alkyl radical optionally bearing at least one hydroxyl group and the radical R is an alkyl radical _C-2, amino optionally substituted by one or two identical or different alkyl groups C1-C4 themselves optionally bearing at least one hydroxy group, said alkyl radicals possibly forming with the nitrogen atom to which they are attached, a heterocycle comprising from 5 to 7 members, saturated or unsaturated optionally substituted optionally comprising at least one other heteroatom different or not from nitrogen;

- alkylcarbonyloxy (RC (O) O-) wherein the radical R is an alkyl radical Ci-C _4, amino group optionally substituted by one or two alkyl groups are identical or different Ci-C ₄ themselves optionally bearing d '' at least one hydroxy group, said alkyl radicals being able to form, with the nitrogen atom to which they are attached, a heterocycle comprising from 5 to 7 members, saturated or unsaturated optionally substituted optionally comprising at least one other heteroatom different or not from l 'nitrogen;

- alkoxycarbonyl (RX _r C (O) -) in which the radical R is a C ₁ -C ₄ alkoxy radical, Xi is an oxygen atom, or an amino group optionally substituted by a C ₁ -C ₄ alkyl group -even possibly carrying at least one hydroxy group, said alkyl radical possibly forming with the nitrogen atom to which they are attached, a heterocycle comprising from 5 to 7 members, saturated or unsaturated optionally substituted optionally comprising at least one other heteroatom different or not from nitrogen;

• a cyclic, heterocyclic radical, or a non-aromatic part of an aryl or heteroaryl radical, can also be substituted by one or more oxo groups;

• an “aryl” radical generally represents a mono or polycyclic carbon group, condensed or not, comprising from 6 to 22 carbon atoms, and of which at least one ring is aromatic; preferably the aryl radical is a phenyl, biphenyl, naphthyl, indenyl, anthracenyl, or tetrahydronaphthyl;

• a “cationic heteroaryl radical” is a heteroaryl group as defined above which comprises an endocyclic or exocyclic cationic group;

- when the charge is endocyclic, it is taken up in the electronic delocalization by mesomeric effect, for example it is a pyridinium, imidazolium or indolinium group:

with R and R 'being a heteroraryl substituent as defined above and particularly a (hydroxy) (Ci-C ₈ ) alkyl group such as methyl;

- when the charge is exocyclic, it is not taken up in the electronic delocalization by mesomeric effect, for example it is a substituent R ⁺ ammonium, phosphonium such as trimethylammonium, found outside of the heteroaryl such as pyridinyle, indolyle, imidazolyle, or naphthalimidyle in question:

with R a heteroaryl substituent as defined below and R ⁺ an ammonium group RaRbRcN ⁺ -, phosphonium RaR _b R _c P ⁺ - or ammonium RaRbRcN ⁺ - (C1C6) alkylamino, R _a R _b R _c N ⁺ - (C1-C6) alkyl or RaRbRcN ⁺ - (C1-C ₆ ) alkoxy with R _a , R _b and R _c identical or different represent a group (Ci-C ₈ ) alkyl such as methyl;

a “heteroaryl radical” represents, in general, a mono or polycyclic group, condensed or not, comprising from 5 to 22 links, from 1 to 6 heteroatoms chosen from the nitrogen, oxygen and sulfur atoms, and at least one cycle of which is aromatic; preferably heteroaryl is selected from acridinyl, benzimidazolyl, benzobistriazolyl, benzopyrazolyl, benzopyridazinyle, benzoquinolyl, benzothiazolyl, benzotriazolyl, benzoxazolyl, pyridinyl, tetrazolyl, dihydrothiazolyl, imidazopyridinyl, imidazolyl, indolyl, isoquinolyl, naphthoimidazolyle, naphthooxazolyle, naphthopyrazolyle, oxadiazolyl, oxazolyl, oxazolopyridyl , phenazinyl, phenooxazolyl, pyrazinyl, pyrazolyl, pyrilyl, pyrazoyltriazyle, pyridyle, pyridinoimidazolyle, pyrrolyle, quinolyle, tétrazolyle, thiadiazolyle, thiazolyle, thiazolopyridinyle, thiazoylimidazolyle, thiopyyylly, thiopyrylyyl, thiopyryyl

• a “heterocyclic radical” is a radical which may contain one or two unsaturations but not aromatic, mono or polycyclic, condensed or not, containing from 5 to 22 links, comprising from 1 to 6 heteroatoms chosen from the nitrogen atom, d oxygen, and sulfur;

• a “heterocycloalkyl radical” is a heterocyclic radical comprising at least one saturated ring;

• an “alkyl radical” is a linear or branched Ci to C ₂ o hydrocarbon radical, preferably to Ci to Cw, more preferably to Ci to C ₈ , better to Ci to C ₆ , and better still to Ci to C ₄ ;

• the expression "optionally substituted" assigned to the alkyl radical implies that said alkyl radical may be substituted by one or more radicals chosen from the radicals: i) hydroxy, ii) alkoxy-C _4, iii) RZ (X) -Y- with X, Y and Z representing an oxygen, sulfur or N (R ') atom, or else X and / or Z represents (s) a bond, R and R', identical or different, represent a hydrogen atom or an (Ci-C ₆ ) alkyl group, preferably X represents an oxygen atom, iv) amino optionally substituted by one or two alkyl radicals, identical or different, in C1-C4, said alkyl radicals possibly form with the nitrogen atom which carries them a heterocycle comprising from 5 to 7 members, optionally comprising another heteroatom different or not from nitrogen; v) a quaternary ammonium group N ⁺ R'R "R '", M' for which R ', R ", R'", identical or different, represent or a C1-C4 alkyl group, or else -N ⁺ R ' R ”R '” forms a 5 or 6-membered heteroaryl such as imidazolium optionally substituted by a C1-C4 alkyl group, and M' represents the anionic counterion, vi) carboxy C (O) OH, vii) carboxylate C ( O) O ', M ⁺ with M ⁺ representing a cationic counterion such as an alkali or alkaline earth metal, viii) sulfonic -SO3H, ix) sulfonate -SO3', M ⁺ with M ⁺ as defined above, x) cyano, and xi) a carbamoyl radical ((R) 2N-C (O) -) wherein R, identical or different, represent a hydrogen atom, an alkyl radical -C ₄ optionally bearing at least one hydroxyl group ;

• a "alkoxy radical" is generally an alkyl-oxy radical for which the alkyl radical is a hydrocarbon radical, linear or branched Ci to C _8, preferably C, to C _6;

• when the alkoxy group is optionally substituted, this implies that the alkyl group is optionally substituted as defined above;

• “organic or mineral acid salt” means more particularly the salts chosen from a salt derived from i) hydrochloric acid HCl, ii) hydrobromic acid HBr, iii) sulfuric acid H ₂ SO ₄ , iv ) alkylsulfonic acids: Alk-S (O) ₂ OH such as methylsulfonic acid and ethylsulfonic acid; v) arylsulfonic acids: Ar-S (O) ₂ OH such as benzene sulfonic acid and toluene sulfonic acid; vi) citric acid; vii) succinic acid; viii) tartaric acid; ix) lactic acid, x) alkoxysulfinic acids: Alk-OS (O) -OH such as methoxysulfinic acid and ethoxysulfinic acid; xi) aryloxysulfinic acids such as tolueneoxysulfinic acid and phenoxysulfinic acid; xii) phosphoric acid H ₃ PO ₄ ; xiii) acetic acid CH ₃ C (O) -OH; xiv) triflic acid CF ₃ SO ₃ H and xv) tetrafluoroboric acid HBF ₄ ;

• “anionic counterion or anion” means an anion or a cosmetically acceptable anionic group, organic or inorganic, derived from organic or mineral acid salt associated with the cationic charge of the dye; more particularly the anion is chosen from i) halides such as chloride, bromide; ii) nitrates; iii) sulfonates including Ci-C ₆ alkylsulfonates: Alk-S (O) ₂ O 'such as methylsulfonate or mesylate and ethylsulfonate; iv) arylsulfonates: Ar-S (O) ₂ O 'such as benzenesulfonate and toluenesulfonate or tosylate; v) the carboxylates Alk-C (O) -OH with Alk representing a (Ci-C ₆ ) alkyl group optionally substituted by one or more hydroxy or carboxylate groups such as citrate; vi) succinate; vii) tartrate; viii) lactate; ix) alkyl sulphates: Alk-OS (O) O 'such as methyl sulphate and ethyl sulphate; x) arylsulfates: Ar-OS (O) O 'such as benzenesulfate and toluenesulfate; xi) alkoxysulfates: Alk-OS (O) ₂ O 'such as methoxy sulfate and ethoxysulfate; xii) aryloxysulfates: Ar-OS (O) ₂ O ', xiii) phosphates O = P (OH) ₂ -O', O = P (O ') ₂ -OH O = P (O') ₃ , HO - [P (O) (O ')] _W -P (O) (O') ₂ with w being an integer; xiv) acetate; xv) triflate; xvi) borates such as tetrafluoroborate; xvii) S (O) ₂ O ₂ 'or SO ₄ ² 'sulfate; xviii) ₄ 'HSO hydrogen sulfate; xix) carbonate; xx) hydrogen carbonate; xxi) perchlorate (CIO ₄ ') and xxii) inorganic dianionic salts such as zinc tetrachloride; the anionic counter ion, derived from organic or mineral acid salt, ensures the electroneutrality of the molecule: thus it is understood that when the anion comprises several anionic charges then the same anion can be used for the electroneutrality of several cationic groups in the same molecule or can be used for the electroneutrality of several molecules; for example a dye which contains two cationic groups can contain either two anionic counter ions "monoloaded" or either contains an anionic counterion "bicharged" such as (O =) ₂ S (O ') ₂ or O = P (O') ₂ -OH;

In particular, the anionic counterions are chosen from halides such as chloride, bromide, fluoride, iodide; a hydroxide; a sulfate; a hydrogen sulfate; alkyl sulfate Ci-C ₆ linear or branched, such as methyl sulfate ion or ethyl sulfate; carbonates and hydrogen carbonates; salts of carboxylic acids such as formate, acetate, citrate, tartrate, oxalate; alkylsulfonates Ci-C ₆ linear or branched such as methylsulfonate ion; arylsulfonates for which the aryl part, preferably phenyl, is optionally substituted by one or more C ₁ -C ₄ alkyl radicals such as, for example, 4-toluylsulfonate; alkyl sulfonyls such as mesylate;

• By “cationic counter ion” is meant the alkaline, alkaline-earth cations or organic cations such as ammoniums, preferably the anionic counterions of the invention are chosen from alkalis such as N ⁺ , or K ⁺ ;

• “Chemical oxidizing agent” means any oxidizing agent other than oxygen in the air conventionally used in the field. Thus, mention may be made of hydrogen peroxide, urea peroxide, alkali metal bramates, persalts such as perborates and persulfates, as well as the enzymes among which mention may be made of peroxidases, oxidoreductases with 2 electrons such as uricases and oxygenases with 4 electrons such as laccases; preferably, the chemical oxidizing agent is hydrogen peroxide;

• Furthermore, the addition salts which can be used in the context of the invention are in particular chosen from addition salts with a cosmetically acceptable base such as the basifying agents as defined below such as the alkali metal hydroxides such as soda, potash, ammonia, amines or alkanolamines;

• the expression "at least one" is equivalent to "one or more";

• the limits of a domain of values are included in this domain, in particular in the expressions "included between" and "going from ... to ..."; and • the expression "inclusive" to mean that the limits of the range are part of the defined interval.

a) The disulfide fluorescent dyes, thiols or protected thiols

The process for dyeing keratin fibers and the composition according to the present invention use, or further comprise b) one or more fluorescent dye (s) disulfide (s), thiol (s) or thiol (s) protected (s).

Particularly the fluorescent dye (s) disulfide (s), thiol (s) or thiol (s) protected (b) of the invention are (are) dyes which absorb light in the range of yellow, orange and red, particularly red, preferably in the absorption wavelength AA _bs inclusively between 400 nm and 500 nm.

Preferably, the disulfide fluorescent dye (s), thiols or thiols protected by the invention are chosen from those formula (la): A - (X) _p - C _sa t - S - U as well as its acid or organic or mineral base, its optical, geometric, tautomeric isomers and their solvates such as hydrates, formula (la), in which:

• U represents a radical chosen from:

a) -S-C ' _sat - (X') _p -A '; and

b) -Y ', • A and A ’, which may be identical or different, represent a radical containing at least one quaternized cationic fluorescent chromophore or at least one fluorescent chromophore carrying a quaternized or quaternizable cationic group;

• Y represents i) a hydrogen atom; or ii) a thiol protecting group;

• X and X ', identical or different, represent a divalent Ci-C ₃₀ hydrocarbon chain, linear or branched, saturated or unsaturated, optionally interrupted and / or possibly terminated at one or both of its ends by one or more groups divalent or combinations thereof chosen from:

> -N (R) -, -N ⁺ (R) (R) -, -O-, -S-, -C (O) -, -S (O) -, -SO ₂ - with R, identical or different, selected from hydrogen, C1-C4 alkyl, hydroxyalkyl, aminoalkyl;

> a (hetero) cyclic radical, aromatic or not, saturated or unsaturated, condensed or not, optionally comprising one or more identical or not identical heteroatoms, optionally substituted;

• p and p ’, identical or different, are worth 0 or 1;

• Csat and C'sat, identical or different, represent a linear or branched, or cyclic, Ci-Ci ₈ alkylene chain, and optionally substituted.

According to a particular embodiment of the invention the dyes (la) are disulfide dyes ie for which U represents the following radical a) -S-C ' _sa t- (X') p'-A ', and more particularly the dyes of formulas (la) are symmetrical ie are such that A = A ', Csat = C'sat, X = X' and p = p '.

According to another particular embodiment of the invention, the dyes of formula (la) with a thiol function are as defined above i.e. U representing the radical b) Y.

Another particular embodiment of the invention is concerned with fluorescent dyes with disulfide, thiol or protected thiol function.

According to a particular embodiment of the invention, the fluorescent dye of formula (lb) is a thiol dye i.e. Y represents i) a hydrogen atom.

In accordance with another particular embodiment of the invention, in the above formula (lb), Y is a protective group known to those skilled in the art, for example those described in the works "Protective Groups in Organic Synthesis", TW Greene, John Willey & Sons ed., NY, 1981, pp. 193-217; “Protecting Groups”, P. Kocienski, Thieme, 3 ^rd ed., 2005, chap. 5,. And Ullmann's Encyclopedia, “Peptide Synthesis”, p. 4-5, 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 10.1002 / 14356007.a19 157.

In particular, Y represents a protective group for the thiol function chosen from the following radicals:

(Ci-C ₄ ) alkylcarbonyl;

(Ci-C ₄ ) alkylthiocarbonyl;

(Ci-C ₄ ) alkoxycarbonyl;

(Ci-C ₄ ) alkoxythiocarbonyl;

(Ci-C ₄ ) alkylthio-thiocarbonyl;

(di) (Ci-C ₄₎ (alkyl) aminocarbonyl;

(di) (Ci-C ₄₎ (alkyl) aminothiocarbonyl;

arylcarbonyl such as phenylcarbonyl;

aryloxycarbonyl;

aryl (Ci-C ₄₎ alkcoxycarbonyle;

(di) (Ci-C ₄₎ (alkyl) aminocarbonyl such as dimethylaminocarbonyl;

(Ci-C ₄ ) (alkyl) arylaminocarbonyl;

carboxy;

SO ₃ '; M ⁺ with M ⁺ representing an alkali metal such as sodium or potassium, or else a counterion of the cationic chromophore A and M ⁺ are absent;

optionally substituted aryl such as phenyl, dibenzosuberyl, or 1,3,5cycloheptatrienyl;

optionally substituted heteroaryl;

heterocycloalkyl optionally substituted, optionally cationic, the heterocycloalkyl group represents in particular a saturated or partially saturated monocyclic group with 5, 6 or 7 members comprising from 1 to 4 heteroatoms chosen from oxygen, sulfur and nitrogen, such as di / tetrahydrofuranyl , di / tetrahydrothiophenyl, di / tetrahydropyrrolyl, dihydropyridyl, morpholinyl, groups being di / tetrahydropyranyl, di / tetra / hexa-hydrothiopyranyl, piperazinyl, piperidinyl, tetramethylpiperidinyl di / tetra / hexahydroidyridyridyridetyride / hexahydroidyridyrazet) (C1-C4) alkyl, oxo or thioxo; where the heterocycle represents the following grouping:

inclusive between 1 and 3; preferably R of hydrogen; and An ’” 'represents a counterion;

-C (NR ' ^c R' ^d ) = N ⁺ R ' ^e R'^f; An ”” with R ' ^c , R' ^d , R ' ^e and represent a hydrogen atom or preferably R' ^c to R ' ^f represent an a represents a counterion;

in which R ′ ^c , R ′ ^d , R ′ ^e , R ′ ^f , R ′ ⁹ and R ′ ^h , which are identical or different, represent a hydrogen atom or a (Ci-C ₄ ) alkyl group, or else two groups R ' ⁹ with R' ^h , and / or R ' ^e with Reform an oxo or thioxo group, or else R' ⁹ with R ' ^e together form a cycloalkyl; and v represents an integer included in R ' ^h represent an atom

R ' ^f , identical or different (Ci-C ₄ ) alkyl group; adorned with hydrogen; and An '”'

-C (NR ' ^c R' ^d ) = NR '^e; with R ' ^c , R' ^d and R ' ^e are as defined above;

(di) aryl (Ci-C ₄ ) optionally substituted alkyl such as 9-anthracenyl-methyl, phenylmethyl or diphenylmethyl optionally substituted by a number of groups in particular chosen from (Ci-C ₄ ) alkyl, (Ci-C ₄ ) alkoxy such as methoxy, hydroxylated, alkylcarbonyl, (di) (Ci-C ₄ ) (alkyl) amino such as dimethylamino;

(di) heteroaryl (Ci-C ₄ ) optionally substituted akyl, the heteroaryl group is in particular, cationic or not, monocyclic, comprising 5 or 6 members and from 1 to 4 heteroatoms chosen from nitrogen, oxygen and sulfur, such as pyrrolyl, furanyl, thiophenyl, pyridyl, pyridyl N-oxide such as 4pyridyl or 2-pyridyl-N-oxide, pyrylium, pyridinium, triazinyl, optionally substituted by one or more groups such as particularly methyl alkyl, advantageously the (di) heteroaryl (Ci-C ₄₎ akyle is (di) heteroarylmethyl or (di) heteroarylethyl;

-CR ¹ R ² R ³ with R ¹ , R ² and R ³ identical or different, representing a halogen atom or a group chosen from:

- (Ci-C ₄ ) alkyl;

- (Ci-C ₄ ) alkoxy;

- optionally substituted aryl such as phenyl optionally substituted by one or more groups such as (Ci-C ₄ ) alkyl, (Ci-C ₄ ) alkoxy, hydroxyl;

- optionally substituted heteroaryl such as thiophenyl, furanyl, pyrrolyl, pyranyl, pyridyl, optionally substituted by a (Ci-C ₄ ) alkyl group;

- P (Z ¹ ) R ' ¹ R' ² R ' ³ with R' ¹ , and R ' ² identical or different represent a hydroxyl group, (Ci-C4) alkoxy or alkyl, R' ³ represents a hydroxyl group or ( C1-C4) alkoxy, and Z ¹ represents an oxygen or sulfur atom;

cyclically sterically congested; and optionally substituted alkoxyalkyl such as methoxymethyl (MOM), ethoxyethyl (EOM) and isobutoxymethyl.

In particular, the fluorescent dye (s) of formula (Ia) are such that Y represents a protective group such as:

> (Ci-C ₄ ) alkylcarbonyl such as methylcarbonyl or ethylcarbonyl;

> arylcarbonyl as phenylcarbonyl;

> (Ci-C ₄ ) alkoxycarbonyl;

> aryloxycarbonyl;

> aryl (Ci-C ₄ ) alkoxycarbonyl;

> (di) (Ci-C ₄ ) (alkyl) aminocarbonyl as dimethylaminocarbonyl;

> (Ci-C ₄ ) (alkyl) arylaminocarbonyl;

> optionally substituted aryl such as phenyl;

> 5- or 6-membered monocyclic heteroaryl such as imidazolyl or pyridyl;

> cationic 5-6 membered monocyclic heteroaryl such as pyrylium, pyridinium, pyrimidinium, pyrazinium, pyridazinium, triazinium, imidazolium; these groups being optionally substituted by one or more, identical or different, (Ci-C ₄ ) alkyl groups such as methyl;

> cationic 8 to 11-membered bicyclic heteroaryl such as benzoimidazolium or benzoxazolium; these groups being optionally substituted by one or more, identical or different, (Ci-C ₄ ) alkyl groups such as methyl;

> cationic heterocycle of the following formula:

Me

Me _An ">> -C (NH ₂ ) = N ⁺ H ₂ ; Year'"'; with An '”' an anionic counter ion as defined above;

> -C (NH ₂ ) = NH; and> SO ₃ ', M ⁺ with M ⁺ representing an alkali metal such as sodium or potassium. As indicated before, in the fluorescent dye (s) of formula (la),

Csat C'sat and, independently of one another represent an alkylene chain Ci-Ci ₈ linear or branched or cyclic, optionally substituted.

As a substituent of said alkylene chain Ci-Ci ₈ ,, there may be mentioned the groups i) amino, ii) (Ci-C ₄₎ alkylamino, iii) (Ci-C ₄₎ dialkylamino, or the group iv) R ^a -Z ^a -C (Z ^b ) 18

Z ^c -, in which Z ^a , Z ^b , identical or different, represent an oxygen atom, sulfur, or a group NRæ, Z ^c , representing a bond, an oxygen atom, sulfur, or a group NR ^a and R ^a represents an alkali metal, a hydrogen atom, or a C1-C4 alkyl group and R ^a 'represents a hydrogen atom or a Cr C ₄ alkyl group; more particularly the groups iv) are chosen from carboxylate C (O) O 'or -C (O) O Metal (Metal = alkali metal), carboxyl -C (O) -OH, guanidino H ₂ HC (NH ₂ ) -NH -, amidino H ₂ HC (NH ₂ ) -, (thio) ureo H ₂ NC (O) -NH- and H ₂ NC (S) -NH-, aminocarbonyl -C (O) -NRa ' ₂ or aminothiocarbonyl -C (S) -NRa '₂; carbamoyl Ra'C (O) -NRa'- or thiocarbamoyl Ra'-C (S) -NRa'- with Ra ', identical or different, representing a hydrogen atom or a (Ci-C ₄ ) alkyl group; the said substituent (s) are preferably present on the carbon in beta or gamma position of the sulfur atoms of the disulfide, thiol or thiol protected group. Preferably, the fluorescent dye (s) formulas (la) are such that C _sa t and C ' _sa t, represent a chain - (CH ₂ ) _k with integer k, inclusive between 1 and 8.

In accordance with a particular embodiment of the invention, the fluorescent dye (s) formulas (la) are such that when p and p 'is equal to 1, X and X', identical or different, represent the following sequence: - ( T) _t - (Z) _z - (T ') v- said sequence being linked in formulas (la) symmetrically as follows: - C _sa t (or C' _S at) - (T) t- (Z ) _z - (A or A '); in which :

• T and T ', identical or different, represent one or more radicals or their combinations chosen from: -O-; -S-; -N (R) -; -N ⁺ (R) (R °) -; -S (O) -; -S (O) ₂ -; -C (O) -; with R, R °, identical or different, representing a hydrogen atom, an alkyl radical Ci-C ₄ hydroxyalkyl, _Ci-C4 or an aryl (Ci-C ₄₎ alkyl; and a heterocycloalkyl or heteroaryl radical, cationic or not, preferentially monocyclic, preferentially containing two heteroatoms (more preferentially two nitrogen atoms) and preferably comprising from 5 to 7 members, more preferentially imidazolium;

the indices t and t ’, identical or different, are worth 0 or 1;

• Z represents:

> - (CH ₂ ) _m - with an integer between 1 and 8;

> - (CH ₂ CH ₂ O) _q - or - (OCH ₂ CH ₂ ) q- in which q is an integer between 1 and 5 inclusive;

> an aryl, alkylaryl or arylalkyl radical in which the alkyl radical is in C ₁ -C ₄ and the aryl radical is preferably in C ₆ , being optionally substituted by at least one SO ₃ M group with M representing a hydrogen atom, a alkali metal or an ammonium group substituted by one or more alkyl radicals, identical or not, linear or branched, in Ci-Cie optionally carrying at least one hydroxyl • z is 0 or 1.

Furthermore, according to a particular embodiment of the invention, Z represents:

SO ₃ M) _0. ,

O ₃ M),

0-4

V'x / 'y vfV where M represents a hydrogen atom, an alkali metal or an ammonium group or an ammonium group substituted by one or more alkyl radicals, identical or not, linear or branched, in C1-C10 optionally carrying 'at least one hydroxyl; 0-4 represents an integer from 0 to 4 inclusive, and q represents an integer from 1 to 6 inclusive.

The fluorescent dye (s) formulas (la) are such that A and / or A ′ represent a quaternized cationic fluorescent chromophore or at least one chromophore carrying a quaternized or quaternizable cationic group. According to a preferred embodiment of the invention, the dyes (la) according to the invention are disulfides and comprise identical and cationic quaternized chromophores A and A ′. More particularly, the dyes of formula (la) according to the invention are disulfides and symmetrical ie contain an axis of symmetry C ₂ , ie the formula (lb) is such that:

A - (X) _p - C _sat - S - S - C ' _sat - (X') _p . - A 'with A = A', X = X ', p = p', C _sat = C ' _sat .

According to a variant, A and / or A ′ of the formulas (la) contain at least one cationic radical carried by or included in at least one of the fluorescent chromophores.

Preferably, the cationic radical is a quaternary ammonium, more preferably the cationic charge is endocyclic. These cationic radicals are for example a cationic radical:

- with exocyclic charge (di / tri) (Ci-C ₈ ) alkylammonium, or

- with an endocyclic charge such as the following cationic heteroaryl groups: acridinium, benzimidazolium, benzobistriazolium, benzopyrazolium, benzopyridazinium, benzoquinolium, benzothiazolium, benzotriazolium, bi-pyridinium, bis-tetrazolium, imidazolium, imidazolium, imidazolium, indidolazolium dihydrothiazolium, naphthoimidazolium, oxadiazolium, phénooxazolium, pyridinoimidazolium, oxazolium, pyrazinium, pyrrolium, naphthopyrazolium, oxonium, phenazinium, pyrazolium, pyrazoyltriazolium, pyridinium, pyrylium, quinolium, tetrazolium, thiadiazolium, thiazolium, thiazolopyridinium, thiazoylimidazolium, thiopyrylium, triazolium or xanthylium.

According to one embodiment of the invention, the fluorescent dye (s) are of formula (la) in which A and / or A 'represents (s) a chromophore chosen from those derived from fluorescent dyes acridines, acridones, benzanthrones, benzimidazoles, benzimidazolones , benzindoles, benzoxazoles, benzopyranes, benzothiazoles, coumarins, difluoro {2 - [(2/7-pyrrol-2-ylidene-kN) methyl] -1H-pyrrolato-kN} bores (BODIPY®), diketopyrrolo-pyrroles, fluorindines, (poly) methines (in particular cyanines and styryles / hemicyanins), naphthalimides, naphthanilides, naphthylamine (like dansyles), oxadiazoles, oxazines, perilones, perinones, perylenes, polyenes / carotenoids, squaranes, stilbenes, and xanthenes; preferably (poly) methines such as styryl or naphthalimides, more particularly of formula (IIa) and (Ilia) or of formula (IVa) and (Va) as defined below.

According to a preferred variant of the invention, the disulfide fluorescent dye (s), thiols or protected thiols of formula (la) are such that A and / or A ’is (are) of formula (llb) and (lllb) below:

W ⁺ - [C (R ^c ) = C (R ^d )] _m -Ar '- (*) Q (lla)

Ar- [C (R ^d ) = C (R ^c )] _m -W ' ⁺ - (*) Q (llla) formulas (lia) or (IHa) with:

• W ⁺ representing a cationic heterocyclic or heteroaryl group, particularly comprising a quaternary ammonium optionally substituted by one or more (Ci-C ₈ ) alkyl groups optionally substituted in particular by one or more hydroxyl groups;

• W ' ⁺ representing a bivalent heterocyclic or heteroaryl radical as defined for W ⁺ ;

• Ar representing an aryl group such as phenyl or naphthyl, optionally preferably substituted by i) one or more halogen atoms, such as chlorine, fluorine; ii) one or more groups (Ci-C ₈₎ alkyl, preferably C1-C4 alkyl such as methyl; iii) one or more hydroxyl groups; iv) one or more (Ci-C ₈ ) alkoxy groups such as methoxy; v) one or more hydroxy (Ci-C ₈₎ alkyl such as hydroxyethyl, vi) one or more amino or (di) (Ci-C ₈₎ alkylamino, preferably with the alkyl part by Ci-C _{4 alkyl} optionally substituted by one or more hydroxyls such as (di) hydroxyethylamino, vii) by one or more acylamino groups; viii) one or more heterocycloalkyl groups such as piperazinyl, pyperidinyl or 5- or 6-membered heteroaryl such as pyrrolidinyl, pyridinyl and imidazolinyl;

• Ar ’is an arylene radical i.e. bivalent aryl as defined for Ar;

• m 'represents an integer inclusive between 1 and 4, particularly m is 1 or 2; more preferably 1;

• R ^c , R ^d , identical or different, represent a hydrogen atom or a group (Ci-C ₈ ) alkyl optionally substituted, preferably in Ci-C ₄ , or then R ^c contiguous to W ⁺ or W ' ⁺ and / or R ^d contiguous to Ar or Ar 'form with the atoms which carry them a (hetero) cycloalkyl, particularly R ^c is contiguous with W ⁺ or W' ⁺ and forms a (hetero) cycloalkyl such as cyclohexyl;

• Q is an organic or mineral anionic counterion as defined above;

• (*) represents the part of the chromophore connected to the rest of the formula (la).

According to another variant, the disulfide dye (s), thiol or thiol protected from the invention are quaternized or quaternizable fluorescent dyes of formula (la) with A and / or A ′ representing a naphthalimidyl chromophore optionally carrying an exocyclic cationic charge of formula (IVa) or (Va):

Ο Μ Ο

R (IVa) or ρ μ η

(Va) formulas (IVa) and (Va) in which:

• R ^e, R ^f, R ^9, and R ^h, identical or different, represent a hydrogen atom or an alkyl group Ci-C ₆ preferably optionally substituted by di (Ci-C6) alkylamino or tri (C -C6) alkylammonium such as trimethylammonium;

• I representing the bond which connects the naphthalimydyle radical to the rest of the molecule by X or X ', if p = 1 or p' = 1 or then by C _sa t or C _sa r if p = 0 or p '= 0.

According to a particular embodiment of the invention the disulfide dye (s), thiol or thiol protected are fluorescent dyes of formula (la) of the invention are such that A and / or A 'is (are) of formula (IIa ) and (Ilia) as defined above, X and X ', identical or different, represent the following sequence - (T) _t - (Z) _z - (T') v- with p = 1, z = t '= O, t = 1 and T represents -N (R) -, preferably in the para position on Ar with respect to the olefin function -C (R ^c ) = C (R ^d ) -. Particularly in a variant p = 1, z = t '= 0, t = 1 and T represents -N (R) -, preferably in the para position on Ar with respect to the styryl function -C (R ^c ) = C ( R ^d ) - and T 'represents a group -N (R) -, -N ⁺ (R) (R °) - or an imidazolium. Preferably, A and / or A 'is (are) of formula (IIa) and (Ilia) as defined above with W ⁺ or W' ⁺ representing a group chosen from imidazolium, pyridinium, benzimidazolium, pyrazolium, benzothiazolium and quinolinium optionally substituted by one or more alkyl radicals, identical or not, C1-C4.

According to a particularly preferred embodiment of the invention the disulfide dye (s), thiol or thiol protected from the invention are quaternized fluorescent dyes of formula (la) such that A and / or A ′ represent the chromophore (IIIb) as as defined above, m '= 1, Ar representing a phenyl group substituted in para of the styryl group -C (R ^d ) = C (R ^c ) - by a (di) (hydroxy) (Ci-C6) (alkyl) group amino such as dihydroxy (Ci-C ₄ ) alkylamino, Q- is as defined previously and W ' ⁺ representing an imidazolium or pyridinium group, preferably ortho or para pyridinium.

According to another preferred embodiment, the disulfide dye (s), thiol or protected thiol (s) are fluorescent dyes of formula (la) in which A and / or A ′ represent a styryl pyridinium group of the following formula:

α β γ

With

R _a , Rb and R _c representing a hydrogen atom or (Ci-C ₆ ) alkyl group, preferably (Ci-C ₆ ) alkyl group such as methyl;

^v representing the bond which connects the styryl radical to the rest of the molecule and An represents an anionic counterion as defined above. Preferably A and A 'represent a β group.

According to a particular embodiment of the invention, the disulfide fluorescent dye (s), thiols or thiols protected with formula (la) are chosen from the following dyes formulas (Via) to (X’a):

h / SS T _b

N- (CR ₁ R ₂ ) _m ' ^X ' (CR3R4) n \ cR'3R'4) n, ^X (CR 'r ·) _ _N

(Via)

N-CCR.R ^ NCR ₃ R ₄ ) _n , s — Y (Vl'a), SS.

HéW- (CR ₁ R ₂ ) _m ^ '(CR ₃ R ₄ ) _n © CR ^ RX ^ CR' ^ VN® ^

M '(VI la) / ^{S — Y}

Hét N-iCR ^^ CF ^

(Vll'a)

(CRiR ₂ ) _m (CRjR ^ a ^ (CR ' ₃ R' ₄ ) _n . ^X (CR 'R')

(Villa)

( ^CR 1 ^R 2) m ' ^X (CRX) _n

-S-Y

, N- (CR ₁ R ₂ ) _m ^ _(CR -; _{R4) n} ^& - (CR'3R'4) n, ^bx '(CR'1R' ₂ ) —N

(IXa)

(IX'a)

-s-Y

R

R-h

M ' ^c c

(Xa)

R

R-h

M 'c

VS

S-Y

R, (X’a) as well as their organic or mineral acid or base salts, its optical, geometric, tautomeric isomers and their solvates such as hydrates, formulas (Via) to (X’a) in which:

• G and G ', identical or different, represent a group -NR _c Rd, -NR' _c R ' _d , or Ci-C ₆ alkoxy optionally substituted, preferably unsubstituted; preferably G and G 'represent a group -NR _c Rd and -NR' _c R'd respectively;

• R _a and R ' _a , identical or different, represent an aryl (Ci-C ₄ ) alkyl group or a Ci-C ₆ alkyl group optionally substituted by a hydroxyl or amino group, Ci-C ₄ alkylamino, Ci-C ₄ dialkylamino, said alkyl radicals being able to form, with the nitrogen atom which carries them, a heterocyle comprising from 5 to 7 members, optionally comprising another heteroatom different or not from nitrogen; preferably R _a and R _'a represents a C ₃ alkyl group optionally substituted by a hydroxyl group, or a benzyl group;

• R _b and R ' _b , identical or different, represent a hydrogen atom, an aryl (Ci-C ₄ ) alkyl group or an optionally substituted Ci-C ₆ alkyl group; preferably R _b and R _b represent a hydrogen atom or a Ci-C ₃ alkyl group or benzyl;

• R _c , R'c, Rd and R'd, identical or different, represent a hydrogen atom, an aryl (Ci-C ₄ ) alkyl, Ci-C ₆ alkoxy group or a Ci-C ₆ alkyl group optionally substituted; R _c , R ' _c , Rd and R'd preferably represent a hydrogen atom, a hydroxyl group, Ci-C ₃ alkoxy, amino, Ci-C ₃ (di) alkylamino, or a Ci-C ₃ alkyl group optionally substituted by i) a hydroxyl group, ii) amino, iii) Ci-C ₃ (di) alkylamino, or iv) quaternary ammonium (R ”) (R '”) (R ””) N ⁺ -;

or two adjacent radicals R _c and R _d , R ' _c and R'd carried by the same nitrogen atom together form a heterocyclic or heteroaryl group; preferably the heterocycle or heteroaryl is monocyclic and comprises between 5 and 7 links; more preferably, the groups are chosen from imidazolyl and pyrrolidinyl;

• R _e and R _e, identical or different, represent a hydrocarbon chain-C ₆ alkylene or C ₂ -C ₆ alkenylene, linear or branched;

• R _f and R ' _f , identical or different, represent a di (CiC ₄ ) alkylamino group, (R ”) (R'”) N- or quaternary ammonium (R ”) (R” ') (R ””) N ⁺ - where R ”, R '” and R ””, identical or different, represent a hydrogen atom or a C1-C4 alkyl group or then (R ”) (R'”) (R ””) N ⁺ - represents a cationic heteroaryl group optionally substituted preferentially an imidazolinium group optionally substituted by a C1-C3 alkyl group;

• R _g , R ' _g , R ” _g R”' _g R _h , R'h, R ”h, and R” 'h, identical or different, represent a hydrogen atom, a halogen atom, a amino, Ci-C ₄ alkylamino, Ci-C ₄ dialkylamino, cyano, carboxyl, hydroxyl, trifluoromethyl, acylamino, alkoxy -C ₄ (poly) hydroxyalkoxy, C ₂ -C ₄ alkoxycarbonyl alkylcarbonyloxy, alkylcarbonylamino, an acylamino, carbamoyl, alkylsulfonylamino radical, an amino-sulfonyl radical, or a Ci-Cw alkyl radical optionally substituted by a group chosen from Ci-Ci ₂ alkoxy, hydroxyl, cyano, carboxy, amino, Ci-C ₄ alkylamino and Ci- C ₄ dialkylamino, or then the two alkyl radicals carried by the nitrogen atom of the amino group form a heterocycle comprising from 5 to 7 members and optionally comprising another heteroatom identical or different to that of the nitrogen atom; preferably R _g , R ' _g , R ” _g , R” ” _g , R _h , R'h, R” h, and R ”' h represent a hydrogen, halogen atom or a Ci-C _{3 group} alkyl;

or then two groups R _g and R '_g; R ” _g and R '” _g ; R _h , and R '_h; R ”h and R '” _h carried by two adjacent carbon atoms, together form a benzo, indeno ring, a fused heterocycloalkyl or fused heteroaryl group; the benzo, indeno, heterocycloalkyl or heteroaryl ring being optionally substituted by a halogen atom, an amino group, Ci-C ₄ alkylamino, Cr C ₄ dialkylamino, nitro, cyano, carboxy, hydroxyl, trifluoromethyl, an acylamino, alkoxy radical in Ci-C ₄ , (poly) hydroxyC ₂ -C ₄ alkoxy, alkylcarbonyloxy alkoxycarbonyl, alkylcarbonylamino, an acylamino, carbamoyl, alkylsulfonylamino radical, an amino-sulfonyl radical, or a Ci-Cw alkyl radical optionally substituted by: a group chosen from Ci-Ci ₂ alkoxy, hydroxyl, cyano, carboxy, amino, Ci-C ₄ alkylamino, Ci-C ₄ dialkylamino, or the two alkyl radicals carried by the nitrogen atom of the amino group form a heterocycle comprising from 5 to 7 links and optionally comprising another heteroatom identical or different to that of the nitrogen atom; preferably R _g and R '_g; R ” _g and R” ' _g together form a benzo group;

or then two groups R, and R _g ; R '”and R” ” _g ; R ', and R'_h; and / or R ”and R” _h together form a fused (hetero) cycloalkyl, preferably cycloalkyl such as cyclohexyl;

or when G represents -NR _c Rd and G 'represents -NR' _c R'd two groups R _c and R '_g; R ' _c and R ” _g ; R _d and R _g ; R _'d and R'_"g together form a heteroaryl or saturated heterocyclic ring, optionally substituted by one or more ether, Ci-C ₆ alkyl, preferably a heterocycle containing one or two heteroatoms selected from nitrogen and oxygen and comprising between 5 and 7 links; more preferably, the heterocycle is chosen from the morpholinyl, piperazinyl, pyperidinyl and pyrrolidinyl groups;

• R ,, R ’,, R” i, and R ’” j, identical or different, represent a hydrogen atom, or a C1-C4 alkyl group;

• Ri, R ₂ , R ₃ , R ₄ , R'i, R'2, R'3, and R ' ₄ , identical or different, represent a hydrogen atom or a Ci-C ₄ alkyl, Ci- Ci ₂ alkoxy, hydroxyl, cyano, carboxy, amino, Ci-C ₄ alkylamino, Ci-C ₄ dialkylamino, said alkyl radicals being able to form with the nitrogen atom which carry them a heterocyle comprising from 5 to 7 members, optionally comprising another heteroatom different or not from nitrogen; preferably R ^ R ₂ , R ₃ , R ₄ , Rj, R ' ₂ , R' ₃ , and R ' ₄ are hydrogen atoms, a (Ci-C ₄ ) alkyl or amino group; more preferably R ^ R ₂ , R ₃ , R ₄ , Rj, R ' ₂ , R' ₃ , and R ' ₄ represent a hydrogen atom;

• T _a , and T _b , identical or different, represent i) either a covalent bond s, ii) either one or more radicals or their combinations chosen from -SO ₂ -, -O-, -S-, -N (R ) -, -N ⁺ (R) (R °) -, -CO-, with R, R °, identical or different, representing a hydrogen atom, a C1-C4 alkyl radical, C1-C4 hydroxyalkyl; or an aryl (Ci-C4) alkyl, preferably Ta is identical to Tb and represent a covalent bond s or a group chosen from -N (R) -, -C (O) -N (R) -, -N (R ) C (O) -, -OC (O) -, -C (O) -O- and -N ⁺ (R) (R °) -, with R, R ° identical or different representing a hydrogen atom or a C1-C4 alkyl group; more preferably T _a and T _b represent a bond; iii) either a heterocycloalkyl or heteroaryl radical, cationic or not, preferentially monocyclic, preferentially identical, preferentially containing two heteroatoms (more preferentially two nitrogen atoms) and preferably comprising from 5 to 7 members such as imidazolium;

Hét N— - N Hét ’n- 'or identical or different, represent an optionally substituted group; preferably the heterocycles are identical, monocyclic, saturated, and comprise a total of two nitrogen atoms and from 5 to 8 members:

• represent an aryl or heteroaryl group fused to the imidazolium or phenyl ring; or else is absent from the imidazolium or phenyl ring; preferably when the cycle is present the cycle is a benzo;

• m, m ’, n and n’, identical or different, represent an integer inclusive between 0 and 6 with m + n, m ’+ rï, identical or different, represents an integer inclusive between 1 and 10; preferably m + n = m ’+ n’ = an integer inclusive between 2 and 4; more preferably m + n = m ’+ n’ = an integer equal to 2;

• Y is as defined above; particularly Y represents a hydrogen atom, or a protective group such as:

> (Ci-C ₄ ) alkylcarbonyl such as methylcarbonyl or ethylcarbonyl;

> arylcarbonyl as phenylcarbonyl;

> (Ci-C ₄ ) alkoxycarbonyl;

> aryloxycarbonyl;

> aryl (Ci-C ₄ ) alkoxycarbonyl;

> (di) (Ci-C ₄ ) (alkyl) aminocarbonyl as dimethylaminocarbonyl;

> (Ci-C ₄ ) (alkyl) arylaminocarbonyl;

> optionally substituted aryl such as phenyl;

> 5- or 6-membered monocyclic heteroaryl such as imidazolyl or pyridyl;

> cationic 5-6 membered monocyclic heteroaryl such as pyrylium, pyridinium, pyrimidinium, pyrazinium, pyridazinium, triazinium, imidazolium; these groups being optionally substituted by one or more, identical or different, (Ci-C ₄ ) alkyl groups such as methyl;

> cationic 8 to 11-membered bicyclic heteroaryl such as benzoimidazolium, or benzoxazolium; these groups being optionally substituted by one or more, identical or different, (Cr C ₄ ) alkyl groups such as methyl;

> cationic heterocycle of the following formula:

> -C (NH ₂ ) = N ⁺ H ₂ ; Year'"'; with An '”' an anionic counter ion as defined above;

> -C (NH ₂ ) = NH;

> SO ₃ ', M ⁺ with M ⁺ representing an alkali metal such as sodium or potassium; and • M'representant anionic counterion, derived from organic or mineral acid salt, or from an organic or mineral base ensuring the electroneutrality of the molecule.

In particular, the dyes of formula (la) are chosen from dyes with chromophore naphthalimidyl disulphides, thiols or protected thiols, chosen from formulas (Villa), (VIIl'a), (IXa) and (IX'a) as defined above. .

According to a preferred embodiment of the invention, the dyes of formula (la) are chosen from disulfide dyes, thiols or protected thiols, chosen from the formulas (Xla) and (Xl’a)

_z (CH ₂ ) —R ^X (CH ₂ ) -R 'as well as their acid or base salts, organic or mineral, optical isomers, geometric isomers, and solvates such as hydrates; formulas (Xla) and (Xl'a) in which:

> R and R '”, identical or different, represent a hydroxyl group, an amino group (NR _a R _b ) or ammonium (N ⁺ R _a R _b R _c ), An'; preferably hydroxyl; with R _a , R _b and R _c , identical or different, representing a hydrogen atom or a (Ci-C ₄ ) alkyl group;

or then two alkyl groups R _a and R _b of the amino or ammonium group form a heterocycle comprising from 5 to 7 members and optionally comprising another heteroatom identical or different to that of the nitrogen atom such as morpholinyl, piperazinyl, piperidinyl, pyrrolyl, morpholinium, piperazinium, piperidinium, pyrrolinium, and An 'representing an anionic counterion;

> R ’and R”, identical or different, represent a hydrogen atom or a group as defined for R and R ’” respectively;

> R _g , R ' _g , R ” _g , R'” _g , R _h , R'h, R ”h and R '” _h , identical or different, represent a hydrogen, halogen atom, a group amino, (di) (Ci-C ₄₎ alkylamino, cyano, carboxy, hydroxyl, trifluoromethyl, acylamino, alkoxy -C ₄ (poly) hydroxyalkoxy, C ₂ -C _4, (Ci-C ₄₎ alkylcarbonyloxy, ( Ci-C ₄ ) alkoxycarbonyl, (Ci-C ₄ ) alkylcarbonylamino, acylamino, carbamoyl, (Ci-C ₄ ) alkylsulfonylamino, an aminosulfonyl radical, or a (Ci-Ci ₆ ) alkyl radical optionally substituted by a group chosen from (Ci -Ci ₂ ) alkoxy, hydroxyl, cyano, carboxy, amino, (di) (Ci-C ₄ ) alkylamino, or then the two alkyl radicals carried by the nitrogen atom of the amino group form a heterocycle comprising from 5 to 7 chain links and optionally comprising another heteroatom identical or different to that of the nitrogen atom; in particular R _g , R ' _g , R ” _g , R”' _g , R _h , R'h, R ”h and R '” h represent a hydrogen atom or a (Ci-C ₄ ) alkyl group;

>R'i, R ”j, R” 'j and R ”” j, identical or different, represent a hydrogen atom, or a (Ci-C ₄ ) alkyl group; particularly R ',, R ”,, R'” ,, and R ””, represents a hydrogen atom;

> m, and m ’, identical or different, represent an integer inclusive between 1 and 10; particularly an integer inclusive between 2 and 4; preferably m and m are worth 2;

> p, p ’, q and q’, identical or different, represent an integer inclusive between 1 and 6;

> Representing an anionic counterion; and> Y is as defined above;

it being understood that when the compound of formula (Xla) or (Xl'a) contains other cationic parts, it is found associated with one or more anionic counterions making it possible to achieve the electroneutrality of the formula (Xla) or (Xl'a).

According to a particular embodiment of the invention, the disulfide fluorescent dyes, thiols or protected thiols b) belong to the formula (Xlla) or (Xll’a) which have an ethylene group linking the pyridinium part to the phenyl in the ortho or para position of the

_z (CH ₂ ) —R ^X (CH ₂ ) -R 'as well as their organic or inorganic acid or base salts, its optical, geometric, tautomeric isomers and their solvates such as hydrates, formula (Xlla) and ( Xll'a) in which R, R ', R ”, R'”, R _g , R ' _g , R ” _g , R'” _g , R _h , R ' _h , R ” _h , R'” _h , R'i, R ”,, R '” ,, R ”” ,, m, m', p, p ', q, q', Y and M 'are as defined above in the formulas (Xla) and ( Xl'a). Particularly R _h , R ” _h are found ortho to the pyridinium group and R ' _h , R” _h represent a hydrogen atom. Another aspect of the invention relates to dyes of formula (Xlla) or (Xll'a) having groups R _g , R ” _g in the 3 'position and R' _g / R” _g which represent a hydrogen atom.

advantageously the dyes of formula (Xlla) and (Xlla'a) have their ethylene group in para of the phenyl carrying the amino group: R '(CH ₂ ) pN- (CH ₂ ) qR and / or R ”(CH ₂ ) p '-N- (CH ₂ ) qR ”', ie in position 4 ', preferably have an ethylene or styryl group connecting the pyridinium part to the phenyl in ortho position of the pyridinium either in 2-4'.

According to another particular embodiment of the invention, the disulfide fluorescent dyes, thiols or protected thiols b) belong to the following formula (XIIla) or (Xlll’a):

as well as their organic or mineral acid or base salts, its optical, geometric, tautomeric isomers and their solvates such as hydrates, formulas (Xllla) or (Xllla’a) in which:

• ι R-represents an alkyl group Ci-C _{6 alkyl} substituted by one or more hydroxy or -C (O) OR 'with R' representing a hydrogen atom, an alkyl group C1-C4 or a group then -C (O) -O 'and in the latter case an anionic counterion An' is absent, particularly R! represents a C ₁ -C ₆ alkyl group substituted by one or more hydroxyl groups and more specifically by a single hydroxyl group;

• R ₂ represents an alkyl group Ci-C _{6 alkyl} optionally substituted by one or more hydroxyl groups;

• or then the R groups! and R ₂ form together with the nitrogen atom which carry them a saturated heterocyclic radical substituted at least by a hydroxyl group, (poly) hydroxy (Ci-C ₄ ) alkyl, and / or -C (O) OR 'with R 'representing a hydrogen atom, an alkyl group or _4-C then -C (O) -O' and in this case against an anionic ion is absent; such as pyrrolidinyl and piperidyl;

• R ₃ represents a hydrogen atom or a -C (O) OR "with R" representing a hydrogen atom, an alkali metal, an alkyl group or Ci-C ₆ then R ₃ is -C (O) -O 'and in this case an anionic counterion An' is absent;

• Z represents a divalent amido group -C (O) -N (R) -, -N (R) -C (O) -, or a divalent C1-C10 alkylene group interrupted by an amido group -C (O) -N (R) -, -N (R) C (O) -so that - (CH ₂ ) _n -C (O) -N (R) - (CH ₂ ) _p -, - (CH ₂ ) _n . -N (R) -C (O) - (CH ₂ ) p-, with n 'representing an integer between 0 and 3 inclusive, preferably n' is 0, 2, 3; p representing an integer inclusive between 0 and 4, n ”representing an integer inclusive between 0 and 3 and in particular n '= n” = p = 0 and R representing a hydrogen atom or a C 1-6 alkyl group

C ₆ ;

• An represents an anionic counter ion;

• Y is as defined above;

it being understood that when the compound of formula (Xllla) or (Xlll'a) contains other cationic parts, it is found associated with one or more anionic counterions making it possible to achieve the electroneutrality of the formula (Xllla) or (Xlll'a).

According to a particular embodiment of the invention, the dyes of the invention belong to the following formula (XVIa) or (XVI ”” a):

j f 2 '

R _a - ° as well as their organic or mineral acid or base salts, its optical, geometric, tautomeric isomers and their solvates such as hydrates, formulas (XVIa) or (XVI ”” a) with:

• R '!, represents a C1-C4 alkyl group substituted by one or more hydroxyl groups, particularly by a single hydroxyl group or -C (O) OR' with R 'representing a hydrogen atom, a C1 alkyl group -C ₄ then -C (O) -O and in the latter case one against an anionic ion is absent, preferably R'-ι, represents an alkyl group Ci-C _{4 alkyl} substituted by a hydroxyl group;

• R _'2 represents an alkyl group Ci-C _{4 alkyl} optionally substituted by one or more hydroxyl groups; particularly by a single hydroxyl group; more particularly Rj and R ' ₂ are identical;

• R _a , Rb and R _c represent a group (Ci-C ₆ ) alkyl such as methyl, in particular they are in position 3 ', 4' and 5 ', or 2', 4 'and 5' or 2 ' , 4 'and 6', preferably they are in position 2 ', 4' and 5 ', • An represents an anionic counter ion as defined above;

• B, represent a bond or a divalent amido group -C (O) -N (R) -, -N (R) -C (O), with R representing a hydrogen atom or a group (Ci-C ₆ ) alkyl; preferably R = H;

• n and m, identical or different, represent an integer inclusive between 1 and 4, preferably n is 3 and m is 2;

• Y is as defined above;

it being understood that the bond between the pyridinium ring and the double bond of the ethylene or styryl group is positioned in position 2 or 4 of the pyridinium, preferably in 4. According to one embodiment B represents an amido group -C (O) -N ( R) -, -N (R) 10 C (O) -, According to another particular embodiment B represents a bond.

According to another preferred embodiment of the invention, the dyes of the invention belong to the formula (XIla) or (XIl’a) as defined above. By way of example, the direct disulfide dyes, thiols and protected thiols of the invention b) have the following chemical structures:

\ ss ^ _ç ^{N + =} ^ ^2M 8 HO \ 'sS ^ z ^N ~ Ç ~ ^ - ^2M OH 9 10 ^HO A ^ ^{+ <} ~ A_ / ^ S ^- S \ _ / ^N ~ Ç ~ ^ - / = \ ₊ ^2M AA ^ OH 11 ^4M ' 16 s \ / N \ \ = / A — TA_ _N ^{Z s} '»// ^N ~ 4M' 17 fAn ^s -s -— nA OO ⁿ '= \ \ = ⁿ / MH) - 2M' 18

OH <7 ^OH N— ¹ λΛ / TT ₊ e. fN— ” _/ ___, ^S oh An- IU ° O / = \ An- HO ? NOT- HO JT TT + τ Γ \ J— '' ^ = ⁷ '—SH An- /-NOT HO ^ G ^ OH 75 76 HO 'f®N—. V ^{Λ = Λ} ^ ^ν · _o ^ ~~ OMe H N- <, _k co, -, - / \ <= + 1 RR © \ J ^ ^ss i _O2 . V >> ~ N OH JT OMe * O “ ⁿ Ùî OH 77 Me * represents an alkali or% alkaline earth metal; or a methyl HO Ί®n—. 7 \ = / l_ -o ^X ° Bone z ^{s' s} IU ° / = \ Z- ^ ^OH o = \ o 78 Î ¹ ° ^ ^Ν ΥΊ ₊ ° ^H 1 ' ^S T HN ^ O 'N ⁺ ~ 1 O 0 81

with Απ 'and M', identical or different, preferably identical, representing anionic counterions. More particularly, the anionic counter ion is chosen from halides such as chloride, alkyl sulphate such as methyl sulphate, mesylate and ^1/2 (O =) 2SO ² 'or ^1/2 SO ₄ ² '.

More preferably, the disulfide fluorescent dyes, thiols or thiole protected a) as defined above are chosen from compounds 31, 44, 49, 49bis and 55, 56, 56bis in particular 44, and 56, 56bis.

According to a particularly advantageous embodiment of the invention the disulfide fluorescent dye (s), thiols, or protected thiols (a) is a dye comprising a so-called “permanent” cationic charge, that is to say having in its structure at least one atom of quaternized nitrogen (ammonium) or quaternized phosphorus (phosphonium); preferably quaternized nitrogen.

The composition according to the invention contains in a cosmetic medium, an amount of fluorescent dye (s) disulfide (s), thiol (s) or thiol (s) protected (s) as defined (s) previously especially of formula (lb) as defined above, in general inclusive between 0.001 and 30% relative to the total weight of the composition which contains it.

Preferably, the amount of fluorescent dye (s) disulfide (s), thiol (s) or protected thiol (s) as defined above, in particular of formula (lb) is included. inclusive between 0.005 and 5% by weight relative to the total weight of the composition. By way of example, the dye (s) is (are) in an amount inclusive between 0.01% and 2% relative to the total weight of the composition comprising it.

b) The activating agent

The method of the invention uses at least one activating agent. The activating agent is a cosmetic composition which comprises i) at least one reducing agent, and ii) at least two different alkaline agents from each other.

il 7® ou_ your reducing agents

The reducing agent (s) i), which are useful for the present invention, are advantageously chosen from the compounds of formula (i) below, as well as their addition salts and their mixtures:

H _s (X) _q (Rio) t (i) formula (i), in which,

- X represents P, S or SO ₂ ,

- q represents an integer equal to 0 or 1 or 2, preferably 1 or 2 with X = S

- s represents an integer equal to 0 or 1

-1 represents an integer equal to 1 or 2, and

R ₁₀ represents an alkyl radical, linear or branched, saturated or unsaturated in Ci to C ₂ o, optionally interrupted by one or more heteroatoms, and / or optionally substituted by one or more radicals chosen from hydroxy, halogenated, amine radicals, carboxy, ((C 1 -C ₃₀ ) alkoxy) -carbonyl, amido, ((C 1 -C ₃₀ ) alkyl) -amino carbonyl, (C 1 -C ₃₀ ) acyl) -amino, mono or dialkylamino, and mono or dihydroxylamino.

Preferably the reducing agent or agents of the invention are thiolated.

More particularly, the reducing agent (s) present in the activating agent (s) used according to the invention are chosen from organic compounds comprising one or more mercapto groups (-SH or -S-), or disulfide (-SS-), preferably -SH (thiol) and at least one other function chosen from the carboxylic acid, amine, amide, ester and alcohol functions and their mixtures.

According to a particular embodiment of the invention, the reducing agent (s) used in the invention are chosen from those of formulas i-1 and i-2, as well as their acid, or base, organic or mineral salts, their optical isomers, their tautomers, and solvates such as hydrates:

R-SH R’-S-R ”i-1 i-2

Formulas i-1 and i-2 in which;

• R represents:

- a (Ci-C ₈ ) alkyl group, preferably (Ci-C ₆ ) alkyl, linear or branched, optionally substituted, preferably substituted, by one or more groups chosen from carboxy C (O) OH, (di) ( Ci-C ₄ ) (alkyl) amino, hydroxy -OH, thiol -SH; and / or possibly interrupted by one or more heteroatoms or groups chosen from -O-, and -S-, -N (R '”) -, C (O) or their associations such as -OC (O) -, —C (O) —O—, -N (R '”) - C (O) -, or -C (O) -N (R'”) -; with R '”representing a hydrogen atom or a (Ci-C ₆ ) alkyl group; or

- a (hetero) aryl group optionally substituted in particular by one or more hydroxy, thiol or carboxy groups;

• R 'and R ”, identical or different, represent a (Ci-C ₈ ) alkyl group, preferably (Ci-C ₆ ) alkyl, preferably substituted by one or more groups chosen from hydroxy, thiol, and carboxy;

or then R 'and R ”together form with the sulfur atom which carry them a heterocyclic group, comprising from 5 to 7, preferably saturated links, comprising from 1 to 3 heteroatoms, optionally substituted (in particular by one or more groups ( Ci-C ₆ ) alkyl optionally substituted by a group or more hydroxy, thiol or carboxy group), more preferably the heterocyclic group is a dithiolane group optionally substituted by a group (Ci-C ₆ ) alkyl optionally substituted by a group or more groups carboxy.

According to a particular embodiment of the invention, the reducing agents are of formula i-1, in particular those for which R represents a (Ci-C ₈ ) alkyl group, preferably (Ci-C ₆ ) alkyl, linear or branched ,

- preferably substituted, by one or more groups chosen from carboxy C (O) OH, amino, hydroxy -OH, thiol -SH; and or

- possibly interrupted by one or more heteroatoms or groups chosen from -O-, -N (R ”') -, C (O) or their associations such as -OC (O) -, -C (O) -O-, -N (R '”) - C (O) -, or -C (O) -N (R”') -. Preferably R represents an (Cr C ₈ ) alkyl group, preferably (Ci-C ₆ ) alkyl, linear or branched uninterrupted.

According to another particular embodiment of the invention, the reducing agents are of formula i-1 for which R represents:

- a phenyl group optionally substituted by one or more hydroxy, thiols or carboxy groups; or

- heteroaryl comprising from 5 to 10 links, preferably bicyclic to 9 or 10 links, comprising from 1 to 4 heteroatoms chosen from O, S or N, preferably N, optionally substituted by one or more hydroxy or thiol groups.

According to another particular embodiment of the invention, the reducing agents are of formula i-2, in particular those for which R ′ and R ″, identical or different, represent a (Ci-C ₈ ) alkyl group, preferably ( Ci-C ₆ ) alkyl, preferably substituted by one or more groups chosen from hydroxy, thiol, and carboxy.

According to another particular embodiment of the invention, the reducing agents are of formula i-2, in particular those for which R ′ and R ″ together with the sulfur atom which carry them form a heterocyclic group, comprising from 5 to 7, preferably saturated links, comprising from 1 to 3 heteroatoms, optionally substituted by one or more (Ci-C ₆ ) alkyl groups optionally substituted by one or more hydroxy, thiol or carboxy group, more preferably the heterocyclic group is a group dithiolane optionally substituted by a (Cr C ₆ ) alkyl group optionally substituted by a group or more hydroxy, thiol or carboxy groups.

Preferably, the reducing agents comprising at least one mercapto or disulfide group of the invention are chosen from thioglycolic acid, thiolactic acid or 2-mercaptopropionic acid, cysteine, cysteamine, homocysteine, glutathione , thioglycerol, thiomalic acid, 3-mercaptopropionic acid, thiodiglycol, 2mercaptoethanol, dithiothreitol, thioxanthine, thiosalicylic acid, thiodiglycolic acid, lipoic acid, / V-acetyl-cysteine , esters and amides of thioglycolic or thiolactic acids, in particular glycerol monothioglycolate, their salts and mixtures of these compounds.

More particularly, the reducing agents comprising at least one mercapto or disulfide group of the invention are chosen from thioglycolic acid, thiolactic acid or 2-mercaptopropionic acid, cysteine, cysteamine, homocysteine, glutathione , thioglycerol, thiomalic acid, 3-mercaptopropionic acid, thiodiglycol, 2-mercaptoethanol, dithiothreitol, thioxanthine, thiosalicylic acid, thiodiglycolic acid, lipoic acid, / V-acetyl -cysteine, the esters and amides of thioglycolic or thiolactic acids, in particular glycerol monothioglycolate, their salts and mixtures of these compounds.

Preferably, the reducing agent (s) according to the invention are chosen by the reducing agents comprising at least one -SH (thiol) group, also called thiol reducing agents.

The thiol-reducing agent (s) can be used in particular in the form of salts, in particular the alkali metal salts such as the sodium and potassium salts, the alkaline earth metal salts, for example the magnesium and calcium salts, the ammonium salts, the amine salts and the amino alcohol salts. It is thus possible to use, as thiol reducing agent, ammonium thioglycolate.

In a particularly preferred manner, the reducing agent (s) i) of the invention are chosen from thioglycolic acid and its salts, thiolactic acid and its salts, cysteamine and its salts, and their mixtures .

Even more preferably, the reducing agent (s) i) of the invention are chosen from thioglycolic acid and thiolactic acid and their salts.

The reducing agent (s) i) preferably thiolated (s) according to the invention, are preferably present in an amount ranging from 1 to 30% by weight, preferably from 5 to 20% by weight, better from 7 to 15% by weight relative to the total weight of the activating agent b) containing it (s).

ii) Jes_aqent_s_ al_c_aji_n_s

The coloring process of the invention uses an activating agent comprising at least two different alkaline agents from one another. In other words, the activating agent comprises two or more of two alkaline agents of which at least two alkaline agents are different: for example the first can be a mineral alkaline agent such as a bicarbonate or a mineral hydroxide and the second can be an organic alkaline agent such as an alkanolamine, or the two alkalis can be mineral alkaline agents the first being a bicarbonate and the second a mineral hydroxide such as ammonium hydroxide, or the two alkaline agents can be organic the first being an alkanolamine and the second a different organic base.

By "alkaline agent" is meant compounds making it possible to increase the pH of the composition or compositions containing it. The alkaline agent is a base of Bronsted, Lowry or Lewis. It can be mineral or organic. The alkaline agent (s) are chosen from mineral, organic and hybrid alkaline agents.

Preferably, the pKa of each alkaline agent is inclusive between 6 and 11.5, more particularly between 9.5 and 11, at room temperature, said alkaline agent being able to present several pKa when it comprises several basic functions. sodium bicarbonate which has two pKa (pKa1 = 6.33 and pKa2 = 10.33). Thus preferably each alkaline agent has one or more pKa which are inclusive between 6 and 11.5, or better between 9.5 and 11 ie each pKa must be preferably between 6 and 11.5, or better between 9, 5 and 11.

The mineral alkaline agent (s) are preferably chosen from alkali (bi) carbonates such as ammonium, sodium or potassium carbonates or bicarbonates, and alkali metal hydroxides, alkaline earth metal hydroxides or hydroxides of ammonium, and silicates, preferably hydroxides of ammonium or ammonia, sodium or potassium.

By "(bi) carbonates" means:

a) carbonates of alkali metal (Met ⁺ 2, CO ₃ ² '), of alkaline earth metal (Met' ²⁺ , CO3 ² ') of ammonium ((R ”4N ⁺ ) 2, CO3 ² ') or of phosphonium ((R ”4P ⁺ ) 2, CO3 ² 'with Met' representing an alkaline earth metal and Met representing an alkali metal, and R”, identical or different, represent a hydrogen atom, a group (Ci- C6) optionally substituted alkyl such as hydroxyethyl), and

b) bicarbonates, also called hydrogen carbonates, of the following formulas:

> R ' ⁺ , HCO3' with R 'representing a hydrogen atom, an alkali metal, an ammonium group R ”4N ⁺ - or phosphonium R” 4P ⁺ - where R ”, identical or different, represent a hydrogen atom , an optionally substituted (Ci-C ₆ ) alkyl group such as hydroxyethyl and when R ′ represents a hydrogen atom the hydrogen carbonate is then called dihydrogen carbonate (CO ₂ , H ₂ O); and> Met ' ²⁺ (HCO ₃ ') ₂ with Met 'representing an alkaline earth metal.

Among the carbonates and bicarbonates suitable for the present invention, there may be mentioned the carbonates and bicarbonates (also called hydrogen carbonates) of Na, K, Mg, Ca and their mixtures, and in particular the carbonate and bicarbonate of Na. These bicarbonates can come from natural water, for example spring water from the Vichy basin, from La Roche Posay, water from Badoit (cf. patent for example the document FR 2 814 943). Particular mention may be made of sodium carbonate [497-19-8] = Na ₂ CO ₃ , sodium hydrogen carbonate or sodium bicarbonate [144-55-8] = NaHCO ₃ , and sodium dihydrogen carbonate = Na (HCO ₃ ) ₂ .

The organic alkaline agent (s) of the invention are preferably chosen from organic amines whose pKb at 25 ° C (pKb = 14 - pKa) is less than 12, and preferably less than 10, even more advantageously less than 6 ,. It should be noted that this is the pKb corresponding to the highest basicity function. In addition, organic amines do not include a fatty chain, alkyl or alkenyl, comprising more than ten carbon atoms.

The organic alkaline agent (s) are preferably chosen from alkanolamines, in particular mono-, di- or tri-hydroxy (Ci-C6) alkylamines such as triethanolamine, oxyethylenated and / or oxypropylenated ethylenediamines, amino acids, polyamines of formula (lb) below and their mixtures:

R.

N-W-N

R, ¹ (Ib) formula (Ib), in which,

W is a divalent C1 to C ₆ alkylene radical optionally substituted by one or more hydroxyl groups or a C1 to C ₆ alkyl radical, and / or optionally interrupted by one or more heteroatoms such as O, or NR _U ; R _x, R _y, R _z, R _t and R _u are identical or different, represent a hydrogen atom, an alkyl radical -C ₆ hydroxyalkyl or -C ₆ aminoalkyl or C, to C _6.

As examples of amines of formula (Ib), there may be mentioned 1,3-diaminopropane, 1,3-diamino-2-propanol, spermine, spermidine.

By “alkanolamine” is meant an organic amine comprising a primary, secondary or tertiary amine function, and one or more alkyl groups, linear or branched, in Ci to C ₈ carrying one or more hydroxy radicals.

Are particularly suitable for the embodiment of the invention the organic amines selected from alkanolamines such as mono-, di- or tri-alkanolamine having one to three hydroxy radicals, identical or different, C l -C _4.

Among compounds of this type, there may be mentioned monoethanolamine (MEA), diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, Ν, Ν-dimethylethanolamine, 2-amino-2-methyl-1-propanol, triisopropanol -amine, 2-amino-2-methyl-1,3-propanediol, 3-amino-1,2-propanediol, 3-dimethylamino1,2-propanediol, tris-hydroxymethylamino-methane.

According to a preferred variant of the invention, the amino acids are of natural or synthetic origin, in their L, D or racemic form and comprise at least one acid function chosen more particularly from the carboxylic, sulfonic, phosphonic or phosphoric. Amino acids can be in neutral or ionic form. As amino acids which can be used in the present invention, mention may in particular be made of aspartic acid, glutamic acid, alanine, arginine, ornithine, citrulline, asparagine, carnitine, cysteine , glutamine, glycine, histidine, lysine, isoleucine, leucine, methionine, N-phenylalanine, proline, serine, taurine threonine, tryptophan, tyrosine and valine.

Advantageously, the amino acids are basic amino acids comprising an additional amine function possibly included in a cycle or in a ureido function. Such basic amino acids are preferably chosen from those corresponding to the following formula (llb):

R-CH ₂ -CH (NH ₂ ) -C (O) -OH, as well as their salts, of acid or base, organic or mineral formula (llb), in which, R represents a group chosen from imidazolyl, of preferably imidazolyl-4-yl; aminopropyl; aminoethyl; - (CH ₂ ) 2N (H) -C (O) -NH ₂ ; and - (CH ₂ ) ₂ -N (H) -C (NH) -NH ₂ . The compounds corresponding to the formula (Ile) are histidine, lysine, arginine, ornithine, citrulline.

The organic amine can also be chosen from organic amines of heterocyclic type. Mention may in particular be made, in addition to the histidine already mentioned in the amino acids, pyridine, piperidine, imidazole, triazole, tetrazole, benzimidazole.

The organic amine can also be chosen from the amino acid dipeptides. As amino acid dipeptides which can be used in the present invention, mention may in particular be made of carnosine, anserine and balenine

The organic amine can also be chosen from compounds comprising a guanidine function. As amines of this type which can be used in the present invention, there may be mentioned in addition to the arginine already mentioned as amino acid, creatine, creatinine, 1,1-dimethylguanidine, 1,1-diethylguanidine, glycocyamine, metformin, agmatine, n-amidinoalanine, 3-guanidino-propionic acid, 4guanidinobutyric acid and 2 - ([amino (imino) methyl] amino) -ethane-1-sulfonic acid .

Mention may be made, as hybrid compounds, of the salts of the amines mentioned above with acids such as carbonic acid, hydrochloric acid.

One can in particular use guanidine carbonate or monoethanolamine hydrochloride.

Preferably, the alkaline agents of the invention are chosen from (bi) carbonates, in particular ammonium bicarbonate, hydroxides, in particular ammonium hydroxide (also called ammonia), alkanolamines, in particular mono-, di - or tri-hydroxy (Ci-C ₆ ) alkylamines, such as lamonoethanolamine.

The alkaline agent (s) are preferably present in a total amount ranging from 0.5 to 30% by weight, more preferably from 1 to 20% by weight, better still from 5 to 15% by weight relative to the total point activating agent b) the container (s).

In particular, the alkaline agents of the invention are chosen from the following mixtures:

1) hydroxide (s) + (bi) carbonate (s), particularly hydroxide (s) + bicarbonate (s), and preferably ammonium hydroxide + ammonium bicarbonate;

2) alkanolamine (s) + (bi) carbonate (s), particularly alkanolamine (s) + bicarbonate (s), and preferably monoethanolamine + ammonium bicarbonate.

According to a particular embodiment of the invention, the number of moles of hydroxides, in particular of ammonium hydroxide contained in the activating agent b) is inclusive between 1. 10 ' ² and 10' ¹ mole, preferably between 2 10 ' ² and 7.10' ² mole, and preferably between 2.5.10 ^-2 and 4.10 ^-2 mole.

According to a particular embodiment of the invention, the activator comprises a mixture of (bi) carbonate (s) and hydroxide (s), more particularly the ratio R by weight (mass) of 1) (bi) carbonate ( s) / hydroxide (s) is greater than or equal to 0.50, preferably R is greater than or equal to 0.60, more preferably R is greater than or equal to 0.70, in particular R is inclusive between 1 and 10, more particularly R is inclusive between 0.60 and 7 and preferably R is inclusive between 1.50 and 5.50.

According to another particular embodiment of the invention, the activator comprises a mixture of (bi) carbonate (s) and alkanolamin (s), more particularly the ratio R ′ by weight of 2) (bi) carbonate (s) ) / alkanolamine (s) is greater than or equal to 0.50, preferably R 'is greater than or equal to 0.70, more preferably R' is greater than or equal to 0.80, in particular R 'is inclusive between 0, 50 and 10, more particularly R 'is inclusive between 0.60 and 7 and preferably R' is inclusive between 0.70 and 5.

According to a particular embodiment of the invention, the mass ratio of the alkaline reducing agent (s) / agent (s) is inclusive between 0.1 and 3.0, preferably between 0.5 and 2.5 and more particularly between 0.7 and 2 or even between 0.8 and 1.5.

Oxidizing agents c)

The process for dyeing keratin fibers and the cosmetic composition according to the present invention can optionally use, or also comprise one or more oxidizing agents c).

By "oxidizing agent" is meant a chemical oxidizing agent i.e. different from oxygen in the air.

More particularly, the oxidizing agent or agents c) are chosen from hydrogen peroxide, systems generating hydrogen peroxide, urea peroxide, bramates or ferricyanides of alkali metals, peroxygenated salts such as, for example, persulfates , perborates, peracids and their precursors and percarbonates of alkali or alkaline earth metals, and mixtures thereof.

Preferably, the oxidizing agent (s) c) are chosen from hydrogen peroxide or systems generating hydrogen peroxide.

According to a preferred embodiment, the system or systems generating hydrogen peroxide are chosen from urea peroxide; the polymer complexes which can release hydrogen peroxide, chosen from polyvinylpyrrolidone / H ₂ O2; oxidases; perborates; and percarbonates.

Preferably, the oxidizing agent (s) c) are hydrogen peroxide, and more preferably hydrogen peroxide in aqueous solution (hydrogen peroxide).

The oxidizing agent (s) c) are advantageously applied in the form of an aqueous composition the total content of chemical oxidizing agents of which is preferably between 0.05 and 5% by weight, and more preferably between 0.1 and 2% by weight, relative to the total weight of the aqueous solution.

According to one embodiment of the invention, the coloring process does not use a chemical oxidizing agent.

According to a preferred embodiment of the invention, the coloring process uses one or more oxidizing agent (s) chemical (s).

According to a preferred embodiment of the invention, the cosmetic composition comprising the ingredients a) and b) and does not include an oxidizing agent.

The cosmetic medium and solvents

The disulfide fluorescent direct dye (s), thiols or thiols protected a), as defined above, the activating agent (s) b) as defined above as well as, when they are present, the oxidizing agent (s) c), can beforehand be dissolved before being applied to the keratin fibers.

In other words, the ingredients used in the coloring process of the present invention may be present in one or more compositions.

The composition or compositions comprising the ingredients according to the present invention are cosmetic compositions, that is to say that they are preferably aqueous. Besides water, they may include one or more organic solvents, or mixtures thereof.

As organic solvent, mention may, for example, be made of C ₂ to C ₄ alkanols, linear or branched, such as ethanol and isopropanol; glycerol; polyols and polyol ethers such as 2-butoxyethanol, propylene glycol, hexylene glycol, dipropylene glycol, propylene glycol monomethyl ether, monoethyl ether and monomethyl ether of diethylene glycol, as well as aromatic alcohols or ethers such as benzyl alcohol or phenoxyethanol, and mixtures thereof.

PH

The pH of the composition (s) used in the coloring process of the invention and of the composition of the invention comprising the ingredients a) and b) as defined above, is preferably between 2 and 12, and more preferably between 3 and 11. It can be adjusted to the desired value by means of acidifying or alkaline agents usually used in dyeing keratin fibers or even using conventional buffer systems.

The pH of the composition which comprises the ingredients a) and / or b) and that of the composition or compositions used in the dyeing process of the invention, (in particular the composition which comprises the reducing agent (s) (s)) is preferably inclusive between 2 and 12, more preferably between 7 and 12, and better still between 8 and 11, such as between 8.5 and 10.5. Among the acidifying agents, the mineral and organic acids as defined above, there may be mentioned, by way of example, the mineral or organic acids such as hydrochloric acid, orthophosphoric acid, sulfuric acid, carboxylic acids such as l acetic acid, tartaric acid, citric acid, lactic acid, sulfonic acids.

Among the alkaline agents, mention may be made of the alkaline agents ii) defined above.

Types of composition

The composition (s) comprising the disulfide fluorescent dye (s), thiols or thiols protected a) and / or the activating agent b) as defined above, can (can) be present in various galenical forms, such as in the form of liquids, lotions, creams, gels, or in any other form suitable for dyeing keratin fibers.

It (s) can also be packaged under pressure in an aerosol can in the presence of a propellant or in a non-aerosol can and form a foam.

additives

When the ingredients used in the coloring process according to the present invention are present in one or more compositions, said composition or said compositions may optionally further comprise one or more additives, different from the ingredients of the invention and among which mention may be made fatty substances, cationic, anionic, non-ionic, amphoteric or zwitterionic surfactants, cationic, anionic, non-ionic, amphoteric polymers or their mixtures, dandruff agents, antiseborrheic agents, hair loss and / or hair regrowth agents , vitamins and pro-vitamins including panthenol, sunscreens, mineral or organic pigments, sequestering agents, plasticizing agents, solubilizing agents, acidifying agents, mineral or organic thickening agents, in particular polymeric thickening agents, opacifying or pearlescent agents, anti- oxidants, hydroxy acids, perfumes, preservatives, pigments and ceramides.

Of course, those skilled in the art will take care to choose this or these optional additional compounds in such a way that the advantageous properties intrinsically attached to the composition (s) according to the invention are not, or not substantially, affected by the planned additions.

The above additives can generally be present in an amount for each of them between 0 and 20% by weight, relative to the total weight of the composition comprising them.

The coloring process

The process for coloring keratin fibers, in particular human fibers such as the hair, according to the present invention comprises applying the following ingredients to said keratin fibers:

a) one or more fluorescent dye (s) disulfide (s), thiol (s) or thiol (s) protected (s), as defined above;

b) one or more activating agent (s) comprising:

i) at least one reducing agent as defined above; and ii) at least two different alkaline agents from each other as defined above;

it being understood that a) the disulfide fluorescent direct dye (s), thiols or thiols protected, and b) the activating agent (s) are applied to said keratin fibers jointly or sequentially.

In other words, the coloring process according to the present invention can be carried out in one or more stages.

According to a preferred embodiment, the disulfide fluorescent direct dye (s), thiols or thiols protected a), as defined above, and the activating agent (s) b) as defined above, are applied jointly (or jointly), that is to say simultaneously, on the keratin fibers. According to this embodiment, the coloring process is carried out in one step.

According to this one-step embodiment, the method comprises a step of applying to said keratin fibers a cosmetic composition according to the invention which comprises one or more disulfide fluorescent direct dyes, thiols or thiols protected a), as defined previously and the activating agent (s) b) as defined above.

In this embodiment, the cosmetic composition comprising the disulfide fluorescent direct dye (s), thiols or thiols protected a), as defined above, and the activating agent (s) b) as defined above can result from the mixture of at least one composition (A) comprising said disulfide fluorescent direct dye (s), thiols or thiols protected a) and at least one composition (B) comprising said activating agent (s) b). According to another embodiment, the direct dye (s) disulfide fluorescents, thiols or protected thiols a), as defined above, and the activating agent or agents b) as defined above are applied to said keratin fibers sequentially, that is to say successively. According to this other embodiment, the coloring process is carried out in at least two steps.

According to a first embodiment in at least two steps, the direct dye (s) fluorescent (s) disulfide (s), thiol (s) or thiol (s) protected (s) a), such as defined above, is (are) applied to the keratin fibers after or to the activating agent (s) b), as defined above. In other words, the direct dye (s) fluorescent (s) disulfide (s), thiol (s) or thiol (s) protected (s) a), as defined ) previously, is (are) applied after the activating agent (s) b), as defined above.

According to this first embodiment, the process for dyeing keratin fibers comprises at least the following two successive steps:

- A first step of applying to said keratin fibers a cosmetic composition comprising one or more activating agent (s) b) comprising i) at least one reducing agent as defined above; and ii) at least two different alkaline agents as defined above, followed by

a second step of application to said keratin fibers of a cosmetic composition which comprises one or more dye (s) fluorescent (s) disulfide (s), thiol (s) or thiol (s) protected (s) a), as defined above.

According to another embodiment in at least two steps, the activating agent (s) b), as defined above, is (are) applied to the keratin fibers posteriorly with direct dye (s) fluorescent (s) disulfide (s), thiol (s) or thiol (s) protected (a), as defined above. In other words, the activating agent (s) b), as defined above, is (are) applied after the fluorescent dye (s) ) disulfide (s), thiol (s) or protected thiol (s) a), as defined above.

According to this embodiment, the process for coloring keratin fibers comprises at least the following two successive steps:

a first step of application to said keratin fibers of a cosmetic composition comprising one or more direct dye (s) fluorescent (s) disulfide (s), thiol (s) or thiol (s) protected (s) a), as defined above, followed by

- a second stage of application to said keratin fibers of a cosmetic composition comprising one or more activating agent (s) b) as defined above.

A rinsing step, preferably with water, can take place after the step of application to the keratin fibers of the composition comprising the activating agent or agents b) as defined above.

Preferably after the keratin fibers are treated with the activating agent or agents b), they are rinsed with water.

The keratin fibers, in particular human fibers such as the hair, which are treated with the process of the invention, can also be pretreated with a detergent composition, i.e. comprising at least one anionic and / or amphoteric surfactant.

Clean hair can be towel-dried or dried before applying the dyes a) and / or the activating agents b).

According to a particular embodiment of the process of the invention the direct dye (s) fluorescent (s) disulfide (s), thiol (s) or thiol (s) protected (s) a), such ( s) as defined above, and the activating agent (s) b) as defined above are applied jointly to the keratin fibers; preferably the method comprises a step of applying to the keratin fibers a cosmetic composition which comprises one or more direct dye (s) fluorescent (s) disulfide (s), thiol (s) or thiol (s) protected (a), as defined above, and i) at least one reducing agent as defined above; and ii) at least two different alkaline agents from each other as defined above.

Preferably, the ingredients a) and b) are applied to the keratin materials in a bath ratio which can range from 0.1 to 10, and more particularly from. From 1 to 5 By “bath ratio” is meant within the meaning of the present invention the ratio between the total weight of composition comprising the ingredient a) and / or b) and the total weight of keratin fibers to be treated.

When the coloring process is carried out in one step, the ingredients a) and b) are advantageously left in place on the keratin fibers for a period ranging from 1 to 60 minutes, preferably greater than 30 minutes and more preferably for a period ranging from 15 to 45 minutes. When the coloring process is carried out in at least two stages, each of the ingredients a) and b) can advantageously be left in place on the keratin materials for a period ranging from 1 to 60 minutes, and more preferably for a period ranging from 5 at 50 minutes better from 10 to 30 minutes At the end of the coloring process according to the invention, in one or at least two steps, the keratin fibers are advantageously rinsed with water. They can optionally be washed with shampoo, followed by rinsing with water, before being dried or left to dry.

When the coloring process is carried out in at least two stages, the keratin fibers are advantageously rinsed with water between each stage. In other words, the coloring process may include an intermediate rinsing step between the application of the first ingredient and the application of the second ingredient. During this intermediate rinsing step, the keratin fibers can optionally be washed with a shampoo, followed by rinsing with water, before being dried or left to dry.

The coloring process according to the present invention can be carried out at room temperature (25 ° C) or under heating.

The reducing agent (s) are found in a cosmetic composition also called activating agent b) comprising i) at least one reducing agent, preferably a thiol-reducing agent and ii) at least two different alkaline agents, particularly one of the alkaline agents is a bicabonate, more particularly an ammonium bicabonate.

According to a particular embodiment of the invention, the dyeing process implements an additional so-called fixing step using a composition comprising one or more oxidizing agents.

when present, the oxidizing agent (s) are applied after application of ingredients a) and b).

The dyeing method according to the present invention can be applied to dry or wet keratin materials, in particular dry or wet keratin fibers, and preferably dry.

According to a particular embodiment of the invention, the method of the invention implements a step of application to the keratin fibers of one or more disulfide fluorescent dyes, thiol (s) or thiol (s) protected (s) ) a) as defined above and at least one activator b) as defined above ie a cosmetic composition preferably comprising as reducing agent i) thioglycolic acid and / or one of its salts, and at least two alkaline agents different from each other ii) as defined above, preferably at least one bicarbonate, followed by a rinsing step, then the application of an oxidizing composition containing at least one oxidizing agent preferably hydrogen peroxide H ₂ O ₂ or Bromate.

According to another particular embodiment of the invention, the method of the invention implements step 1) of application of at least one activator b) as defined above ie a cosmetic composition preferably comprising as agent reducing agent i) thioglycolic acid and / or one of its salts, then 2) the application of a coloring composition comprising one or more fluorescent disulfide dyes, thiol (s) or protected thiol (s) a) as defined above, then 3) the application of an oxidizing composition containing at least one oxidizing agent preferably hydrogen peroxide H ₂ O ₂ or Bromate.

According to a particular embodiment of the invention, the coloring method of the invention is such that, taken together or separately:

(1) the activating agent comprises i) at least one reducing agent as defined above and ii) at least two different alkaline agents from one another as defined above, of which one of the two alkaline agents is a preferably bicarbonate of ammonium bicarbonate;

(2) the pause time on hair (of the mixture) is greater than or equal to 10 minutes;

(3) before applying the mixture, any detergent pre-treatment with a composition comprising at least one anionic and / or amphoteric surfactant; clean hair can be damp or dry before applying the mixture; and (4) optionally, the method implements a finishing step with a postque defined above, preferably hydrogen peroxide or bromate derivative.

According to a particular embodiment of the invention, the method is a dyeing process implemented on discolored keratin fibers in particular of tone height greater than 6, preferably of tone height between 7 and 8, more preferably between 8 and 9. The colors obtained are then very tenacious vis-à-vis external agents, in particular vis-à-vis light and shampoos.

In a preferred variant of the invention, the method implements a pretreatment step with a detergent composition comprising at least one anionic and / or amphoteric surfactant. Preferably said pretreatment with the detergent composition is carried out between 1 second and 1 hour, particularly between 1 minute and 30 minutes, more particularly between 5 minutes and 15 minutes, before the application of the ingredients a) and b) as defined above.

The device with several compartments

The present invention also relates to a device with several compartments comprising a first compartment containing one or more disulfide fluorescent direct dyes, thiols or thiols protected a), as defined above, a second compartment comprising one or more activating agents b) as defined previously, and optionally another compartment comprising one or more oxidizing agent c) as defined above.

use

The present invention also relates to the use of one or more direct dye (s) fluorescent (s) disulfide (s), thiol (s) or thiol (s) protected (s) a), such ( s) as defined above, associated with one or more activating agent (s) b) as defined above, for dyeing keratin fibers, in particular human fibers, such as hair, in intense, chromatic color and / or with a good color boost, without using an additional dye other than a).

The present invention also relates to the use of one or more direct dye (s) fluorescent (s) thiol (s) or thiol (s) protected (s) a), as (s) as defined ( s) previously, associated with one or more activating agent (s) b) as defined above, for the coloring and / or lightening of dark keratin fibers, in particular human keratin fibers, such as hair with a pitch less than 6, preferably less than or equal to 4, without using an additional dye other than a).

The present invention also relates to the use of one or more direct dye (s) fluorescent (s) thiol (s) or thiol (s) protected (s) a), as (s) as defined ( s) previously, associated with one or more activating agent (s) b) as defined above, for the coloring of discolored keratin fibers in particular with a tone height greater than 6 , preferably with a pitch between 7 and 8, more preferably between 8 and 9. The colorings obtained on discolored keratin fibers are particularly tenacious vis-à-vis external agents such as shampoos or light.

The following examples serve to illustrate the invention without, however, being limiting in nature.

EXAMPLES

In the examples which follow, all the quantities are indicated in percentage

- Heating table thermostatically controlled at 27 ° C

- Natural chestnut hair, tone height 4 (HT4)

- Application of the mixture 90% coloring formula comprising dye A or dye B + 10% of activating agent, at a rate of 5 g of mixture per g of hair

- Pause time 30 minutes then Rinse

- Application of the oxidizing composition at a rate of 5 g of composition per g of hair

-Pause time 5 minutes then Rinse and dry in the open air or hair dryer

The amounts of the compositions in the tables below are indicated by weight of active material (g per 100 g unless otherwise stated)

Activating agents: reducing agent + ammonia:

Agent activator 1 2 3 4 5 6 7 Hydroxide ammonium 1.152 3.94 (0.11 mol) 1,152 (0.03 mol) 2.06 2.88 3.29 3.7 Bicarbonate ammonium 0 0 6.3 (0.08 mol) 6.3 6.3 6.3 6.3 thioglycolate ammonium 11.15 11.15 11.15 11.15 11.15 11.15 11.15 EDTA 0.092 0.092 0.092 0.092 0.092 0.092 0.092 Oleth-20 3 3 3 3 3 3 3 Water qs 100 qs 100 qs 100 qs 100 qs 100 qs 100 qs 100

Activating agents: reducing agent + alkanolamine: monoethanolamine:

Agent activator 8 9 10 11 12 13 14 MEA 2 6.84 (0.11 mol) 2 (0.03 mol) 3.57 5 5.71 6.43 Bicarbonate ammonium 0 0 6.3 (0.08 mol) 6.3 6.3 6.3 6.3 thioglycolate ammonium 11.15 11.15 11.15 11.15 11.15 11.15 11.15 EDTA 0.092 0.092 0.092 0.092 0.092 0.092 0.092 Oleth-20 3 3 3 3 3 3 3 Water qs 100 qs 100 qs 100 qs 100 qs 100 qs 100 qs 100

Coloring composition Composition A Composition B Cetearyl Alcohol 6 6 Steareth-20 0.74 0.74 phenoxyethanol 0.7 0.7 conservative qs qs

Cetrimonium Chloride 0.75 0.75 hydroxyethylcellulose 0.25 0.25 Polyurethane-39 1 1 monoethanolamine 0.01 0.01 Perfume 0.8 0.8 Dye A 0.5 - Dye B - 0.5 Water Qsp 100 Qsp 100

Oxidizing composition / Ingredients Composition C Hydrogen peroxide 0.24 Stabilizers, sequestrants qs Polyquaternium-6 0.05 Polyquaternium-37 2.5 Mineral oil 1.75 PPG-1 trideceth-6 0.3 Phosphoric acid Qs pH = 2.8 + - 0.2 Water Qsp 100

Visual observation:

The combination according to the invention therefore makes it possible to obtain more intense shades, with an excellent rise in color.

Spectrocolorimetric results

The color of the locks was evaluated in the L * a * b * system using a MINOLTA® CM 3600D spectrocolorimeter, (Illuminant D65).

In this system L * a * b *, L * represents the brightness, a * indicates the green / red color axis and b * the blue / yellow color axis. The higher the value of L, the lighter or less intense the color. Conversely, the lower the value of L, the darker or very intense the color. The higher the value of a * the more the shade is red and the higher the value of b * the more the shade is yellow.

The rise in color on hair corresponds to the variation in coloring between the locks of non-colored hair and colored hair is measured by (ΔΕ) according to the following equation:

Δ E = V (L * - L „*) ² + (a * - a ₀ *) ² + (b * - b„ *) ²

In this equation, L *, a * and b * represent the values measured after coloring the hair and L _o *, a ₀ * and b ₀ * represent the values measured before coloring the hair.

The higher the value of ΔΕ, the better the hair color rise.

The chromaticity is calculated according to the following formula:

C * = 7 (a *) ² + (b *) ²

The higher the value of chromaticity C *, the more the color of the treated keratin fibers is chromatic.

EXAMPLE 1 Composition A with Dye A / activating agent 9 (1 single alkaline agent = MEA) vs. activating agent 10 (2 alkaline agents = MEA + ammonium bicarbonate) with equivalent total molar amount of alkaline agent (s) The application carried out on Caucasian hair HT4:

L * at* b * Uncolored control wick 17 3 3

Mixed at* b * VS* \ E * A + 9 comparison 6.46 6.84 9.41 6.92 A + 10 invention 8.82 8.3 12,11 9.22

In this comparison, for an identical total alkalinity (in moles), it appears that the rise in the color ΔΕ and the chromaticity C * are significantly higher when an activating agent comprising a reducing agent with two alkaline agents is applied rather than a reducing agent with a single alkaline agent.

EXAMPLE 2 Composition A with Colorant A / activating agent 2 (1 single alkaline agent = NH ₄ OH) vs. activating agent 3 (2 alkaline agents = NH ₄ OH + ammonium bicarbonate) with a total molar amount of equivalent alkaline agent (s)

The application carried out on Caucasian hair HT4 with an acid pretreatment on the hair (sweat simulation, care (acid) not rinsed) without pre-treatment shampoo

Mixed L * \ E * A + 2 comparison 21.42 5.31 A + 3 invention 23.73 7.51

In this comparison, acidity was applied to the hair to simulate sweat (lactic acid) or the presence of an acid rinse-out treatment.

We don't do shampoo pre-treatment

For an identical total alkalinity (in moles), it appears that the wick appears significantly lighter the rise in color ΔΕ are significantly higher when an activating agent comprising a reducing agent with two alkaline agents is applied rather than a reducing agent with a only alkaline agent.

EXAMPLE 3: Composition B with Dye B / activating agent 9 (1 single alkaline agent = MEA) vs. activating agent 10 (2 alkaline agents = MEA + ammonium bicarbonate) with a total molar amount of equivalent alkaline agent (s).

The application carried out on Caucasian hair HT4 with a pretreatment of acidity on the hair (sweat simulation, care (acid) not rinsed). The hair is then washed with a shampoo before treatment

Mixed at* b * VS* \ E * A + 9 comparison 8.53 6.7 10.85 7.89 A + 10 invention 10.4 8.04 13.15 9.98

In this comparison, for an identical total alkalinity (in moles), it appears that the rise in the color ΔΕ and the chromaticity C * are significantly higher when an activating agent comprising a reducing agent with two alkaline agents is applied rather than a reducing agent with a single alkaline agent.

EXAMPLE 3 Composition A with colorant A / Comparison of normal hair vs. hair with acidity to simulate sweat (lactic acid) or the presence of an acid rinse. Application of the same activating agent 12 (2 alkaline agents = MEA + ammonium bicarbonate)

Wick treated at* b * VS* \ E * Pretreated acid 4.24 4.99 6.55 4.94 Acid pre-treated + shampoo 6.67 7.11 9.75 7.23

In this comparison, acidity was applied to the hair to simulate sweat (lactic acid) or the presence of an acid rinse-out treatment. We perform a shampoo vs. pre-treatment no shampoo pre-treatment with the same activating agent 12.

It appears that the shampoo pre-treatment makes it possible to eliminate the acidity present on the hair well, which makes it possible to obtain an even better ΔΕ and chromaticity C * vs the process without shampoo pre-treatment on acid hair.

EXAMPLE 4 Composition B with Colorant B / Comparison of Normal Hair vs.

hair with acidity to simulate sweat (lactic acid) or the presence of an acid rinse. Application of the same activating agent 3 (2 alkaline agents = NH ₄ OH + ammonium bicarbonate).

Wick treated at* b * VS* \ E * Pretreated acid 4.36 4.12 6.00 3.94 Acid pre-treated + shampoo 8.47 7.15 11.08 8.04

In this comparison, acidity was applied to the hair to simulate sweat (lactic acid) or the presence of an acid rinse-off treatment. We perform a shampoo vs. pre-treatment no shampoo pre-treatment with the same activating agent 3.

It appears that the shampoo pre-treatment makes it possible to eliminate the acidity present on the hair well, which makes it possible to obtain an even more improved ΔΕ and chromaticity C * vs the process without shampoo pre-treatment on acid hair.

EXAMPLE 5: Composition B with Colorant B / Comparison of normal hair vs. 5 hair with acidity to simulate sweat (lactic acid) or the presence of a leave-in acid treatment. Application of the same activating agent 5 (2 alkaline agents = NH ₄ OH +

Ammonium bicarbonate).

Wick treated at* b * VS* \ E * Pretreated acid 6.37 6.13 8.84 6.07 Acid pre-treated + shampoo 10.7 8.18 13.47 10,30

In this comparison, acidity was applied to the hair to simulate sweat (lactic acid) or the presence of an acid rinse-off treatment. We perform a shampoo vs. pre-treatment no shampoo pre-treatment with the same activating agent 5.

It appears that the shampoo pre-treatment makes it possible to eliminate the acidity present on the hair well, which makes it possible to obtain an even more improved ΔΕ and chromaticity C * vs the process without shampoo pre-treatment on acid hair.

Claims (2)

1. Process for dyeing keratin fibers, in particular human fibers such as the hair, consisting in applying to said fibers: > a) one or more disulfide fluorescent direct dyes, thiols or protected thiols; > b) one or more activating agents comprising: i) at least one reducing agent; and ii) at least two different alkaline agents from each other; it being understood that a) the disulfide fluorescent direct dye (s), thiols or thiols protected, and b) the activating agent (s) are applied to said keratin fibers in a joint or sequential manner, 2. Method according to any one of the preceding claims, in which the fluorescent dye (s) disulfide (s), thiol (s) or thiol (s) protected (s) a) is (are) chosen (s) among the dyes which absorb light in the range of yellow, orange and red, particularly red, preferably in the absorption wavelength X _ab s inclusive between 400 nm and 500 nm. 3. Method according to any one of the preceding claims in which the fluorescent dye (s) disulfide (s), thiol (s) or thiol (s) protected (s) a) is (are) chosen (s) among those of formula (la): A - (X) _p - C _sa t - S - U as well as its organic or mineral acid or base salts, its optical, geometric, tautomeric isomers and their solvates such as hydrates , formula (la), in which: > U represents a radical chosen from: a) - S - C ' _S at - (X') p'- A '; and b) -Y; > A and A ’, identical or different, represent a radical containing at least one quaternized cationic fluorescent chromophore or at least one fluorescent chromophore carrying a quaternized or quaternizable cationic group; > Y represents i) a hydrogen atom; or ii) a protective group of thiol function, in particular hydrogen; > X and X ', identical or different, represent a divalent C1-C30 hydrocarbon chain, linear or branched, saturated or unsaturated, optionally interrupted and / or possibly terminated at one or both of its ends by one or more divalent groups or their combinations chosen from: • -N (R) -, -N ⁺ (R) (R) -, -O-, -S-, -C (O) -, -S (O) -, -SO ₂ - with R, identical or different, selected from hydrogen, alkyl Ci-C ₄ hydroxyalkyl, aminoalkyl; • a (hetero) cyclic radical, aromatic or not, saturated or unsaturated, condensed or not, optionally comprising one or more identical or not identical heteroatoms, optionally substituted; > p and p ’, identical or different, are worth 0 or 1; > Csat and C’sat, identical or different, represent a C1-C18 alkylene chain, linear or branched, or cyclic, and optionally substituted; preferably the dyes (la) are disulfide dyes ie for which U represents the following radical a) -S-C ' _S at- (X') p'-A ', and more particularly the dyes of formulas (la) are symmetrical ie are such that A = A ', C _sa t = C' _sa t, X = X 'and p = p'. 4. Method according to the preceding claim in which the fluorescent dye (s) of formula (la) is (are) such (s) that when p and / or p 'is equal to 1, X and / or X ', identical or different, represent the following sequence: - (T) r (Z) z- (T') v- said sequence being linked in formulas (la) symmetrically as follows: - Csat (or C ' sat) - (T) _t - (Z) z- (A or A ') in which: • T and T ', identical or different, represent one or more radicals or their combinations chosen from: -O-; -S-; -N (R) -; -N ⁺ (R) (R °) -; -S (O) -; -S (O) 2-; -C (O) -; with R, R °, identical or different, representing a hydrogen atom, an alkyl radical Ci-C ₄ hydroxyalkyl, _Ci-C4 or an aryl (Ci-C ₄₎ alkyl; and a heterocycloalkyl or heteroaryl radical, cationic or not, preferentially monocyclic, preferentially containing two heteroatoms (more preferentially two nitrogen atoms) and preferably comprising from 5 to 7 members, more preferentially imidazolium; the indices t and t ’, identical or different, are worth 0 or 1; • Z represents: - - (CH ₂ ) _m - with integer m between 1 and 8; - - (CH ₂ CH ₂ O) _q - or - (OCH ₂ CH ₂ ) _q - in which q is an integer between 1 and 5 inclusive; - an aryl radical, alkylaryl or arylalkyl in which the alkyl moiety is Ci-C ₄ and the aryl radical is preferably Ce, optionally substituted by at least one SO ₃ M group with M representing hydrogen, a metal alkaline or an ammonium group substituted by one or more alkyl radicals, identical or not, linear or branched, in Ci-Ci ₈ optionally carrying at least one hydroxyl; • z is 0 or 1. 5. Method according to any one of claims 3 or 4 wherein the fluorescent dye (s) disulfide (s), thiol (s) or thiol (s) protected (s) of formula (la) is (are) such (s) as A and / or A 'is (are) chosen (s) from the chromophores derived from fluorescent dyes (poly) methine or naphthalimides; and preferably chosen from among: > of the following formulas (llb) and (Illb): W ⁺ - [C (R ^c ) = C (R ^d )] _m '—Ar' - (*) Q (Ha) Ar- [C (R ^d ) = C (R ^c )] m'-W ' ⁺ - (*) Q' (Hla) formulas (lia) or (Ilia) with: • W * representing a cationic heterocyclic or heteroaryl group, particularly comprising a quaternary ammonium optionally substituted by one or more (Ci-C ₈ ) alkyl groups optionally substituted in particular by one or more hydroxyl groups; • W ' ⁺ representing a bivalent heterocyclic or heteroaryl radical as defined for W ⁺ ; • Ar representing an aryl group such as phenyl or naphthyl, optionally preferably substituted by i) one or more halogen atoms, such as chlorine, fluorine; ii) one or more (Ci-C ₈ ) alkyl groups, preferably Ci-C ₄ such as methyl; iii) one or more hydroxyl groups; iv) one or more (Ci-Ce) alkoxy groups such as methoxy; v) one or more hydroxy (Ci-C ₈₎ alkyl such as hydroxyethyl, vi) one or more amino or (di) (Ci-C ₈₎ alkylamino, preferably with the alkyl part by Ci-C _{4 alkyl} optionally substituted by one or more hydroxyls such as (di) hydroxyethylamino, vii) by one or more acylamino groups; viii) one or more heterocycloalkyl groups such as piperazinyl, pyperidinyl or 5 or 6-membered heteroaryl such as pyrrolidinyl, pyridinyl and imidazolinyl Af is an arylene radical ie divalent aryl as defined for Ar; • m 'represents an integer inclusive between 1 and 4, particularly m is 1 or 2; more preferably 1; • R ^c , R ^d , identical or different, represent a hydrogen atom or a group (Ci-C ₈ ) alkyl optionally substituted, preferably in Ci-C ₄ , or then R ^c contiguous to VIT or W ' ⁺ and / or R ^d contiguous to Ar or Ar * form with the atoms which carry them a (hetero) cycloalkyle, particularly R ^c is contiguous with W ⁺ or W ' ⁺ and forms a (hetero) cycloalkyle such as cyclohexyle; • Q is an organic or mineral anionic counterion as defined above; • (*) represents the part of the chromophore connected to the rest of the formula (la); preferably, W ⁺ or W ⁺ is an imidazolium, pyridinium, benzimidazolium, pyrazolium, benzothiazolium or quinolinium radical optionally substituted with a radical or more identical or different C1-C4 alkyl radicals; preferably the fluorescent chromophore (s) are chosen from those with m '= 1, Ar representing a phenyl group substituted para for the styryl group -C (R ^d ) = C (R ^c ) - with a group (di) (hydroxy) (Ci-C6) (alkyl) amino such as dihydroxy (Ci-C4) alkylamino, and W ′ ⁺ representing an imidazolium or pyridinium group, preferably ortho- or para-pyridinium; > of formula (IVa) or (Va): R ⁹ formulas (IVa) and (Va) in which: • R ^e , R ^f , R ⁹ , and R ^h , which may be identical or different, represent a hydrogen atom or a C1-C6 alkyl group optionally preferably substituted by a di (Ci-C6) alkylamino or tri (Ci- C ₆ ) alkylammonium such as trimethylammonium; representing the bond which connects the naphthalimydyl radical to the rest of the molecule by X or X ’, if p = 1 or p’ = 1 or then by Csat or Csar if p = 0 or p ’= 0. 6. Method according to any one of the preceding claims, in which the fluorescent dye (s) disulfide (s), thiol (s) or thiol (s) protected (s) a) is (are) chosen (s) from the following colorants formulas (Via) to (X'a): l \ Æ R "| \\ ^ ^Ta \ ^ ^S " ^S \ - Vn (CR ^^ h, (CR ₃ R ₄ ) _n (CR'aR'Jrt ^ iCR ^ Ry — N R '; (Via) N-iCR.R ^ \ CR ₃ R ₄ ) _n , S — Y, s — s _v (Vl'a) Je ^ N-iCR.R ^ ( _C R ₃ R ₄ ) _n Vr ^ J ^ cR ^ R ^ NJ ^ (Vlla) (Vll'a), S — Y (Villa) -S-Y N-iCR.R ^ ^ (CR ₃ R ₄ ) _n ^b yCR ' ₃ R' ₄ ) _rf % CRjR ' ₂ ) —N (IXa) -s-Y -s-s. (Xa) (X'a) as well as their organic or mineral acid or base salts, its optical, geometric, tautomeric isomers and their solvates such as hydrates, formulas (Via) to (X'a) in which : • G and G ', identical or different, represent a group -NR _c Rd, -NR'cR'd, or Ci-C ₆ alkoxy optionally substituted, preferably unsubstituted; preferably G and G 'represent a group -NR _c Rd and -NR'cR'd respectively; • R _a and R ′ _a , identical or different, represent an aryl (Ci-C4) alkyl group or a Ci-Ce alkyl group optionally substituted by a hydroxyl or amino group, Ci-C ₄ alkylamino, C1-C4 dialkylamino, said alkyl radicals which can form, with the nitrogen atom which carries them, a heterocyle comprising from 5 to 7 members, optionally comprising another heteroatom different or not from nitrogen; preferably R _a and R ' _a represent a C1-C3 alkyl group optionally substituted by a hydroxyl group, or a benzyl group; • Rb and R'b, identical or different, represent a hydrogen atom, an aryl (Ci-C ₄ ) alkyl group or an optionally substituted Ci-Ce alkyl group; preferably Rb and R'b represent a hydrogen atom or a C1-C3 alkyl or benzyl group; • Rc, R'c, Rd and R'd, identical or different, represent a hydrogen atom, an aryl (CiC ₄ ) alkyl group, CrCe alkoxy or an optionally substituted Ci-Ce alkyl group; R _c , R ' _c , Rd and R' _d preferably represent a hydrogen atom, a hydroxyl group, C1-C3 alkoxy, amino, C1-C3 (di) alkylamino, or a C1-C3 alkyl group optionally substituted by i ) a hydroxyl group, ii) amino, iii) C1-C3 (di) alkylamino, or iv) quaternary ammonium (R ”) (R '”) (R ””) N ⁺ -; or then two adjacent radicals R _c and Rd, R'c and R'd carried by the same nitrogen atom together form a heterocyclic or heteroaryl group; preferably the heterocycle or heteroaryl is monocyclic and comprises between 5 and 7 links; more preferably, the groups are chosen from imidazolyl and pyrrolidinyl; • Re and R’e, identical or different, represent a Α-Οβ alkylene or C2-C6 alkenylene hydrocarbon chain, linear or branched; • Rf and R'f, identical or different, represent a group di (CiC ^ alkylamino, (R ”) (R” ') N- or quaternary ammonium (R ”) (R'”) (R ””) N ⁺ - where R ”, R '” and R ””, identical or different, represent a hydrogen atom or a C1-C4 alkyl group or else (R ”) (R'”) (R ””) N ⁺ - represents a cationic heteroaryl group optionally substituted preferentially an imidazolinium group optionally substituted by a C1-C3 alkyl group; • R _g , R'g, R ” _g , R '” g, Rh, R'h, R ”h, and R'” h, identical or different, represent a hydrogen atom, a halogen atom, an amino group, C1-C4 alkylamino, C1-C4 dialkylamino, cyano, carboxy, hydroxyl, trifluoromethyl, an acylamino radical, C1-C4 alkoxy, (poly) hydroxy C2-C4 alkoxy, alkylcarbonyloxy alkoxycarbonyl, alkylcarbonylamino, acylamino radical, carbamoyl, alkylsulfonylamino, an amino-sulfonyl radical, or a C1-C16 alkyl radical optionally substituted by a group chosen from C1-C12 alkoxy, hydroxyl, cyano, carboxy, amino, C1-C4 alkylamino and C1-C4 dialkylamino, or so two alkyl radicals carried by the nitrogen atom of the amino group form a heterocycle comprising from 5 to 7 members and optionally comprising another heteroatom identical or different to that of the nitrogen atom; preferably R _g , R ' _g , R ” _a , R” ” _g , Rh, R'h, R” h, and R' ”h represent a hydrogen atom, a halogen atom or a C1-C3 alkyl group; or then two groups R _g and R '_g; R ” _g and R '” _g ; Rh, and R '_h; R ”h and R '” _h carried by two adjacent carbon atoms, together form a benzo, indeno ring, a fused heterocycloalkyl or fused heteroaryl group; the benzo, indeno, heterocycloalkyl or heteroaryl ring being optionally substituted by a halogen atom, an amino group, C1-C4 alkylamino, C1C ₄ dialkylamino, nitro, cyano, carboxy, hydroxyl, trifluoromethyl, an acylamino, C1-alkoxy radical C4 (poly) hydroxyalkoxy, C2-C4 alkylcarbonyloxy alkoxycarbonyl, alkylcarbonylamino, acylamino, carbamoyl, alkylsulfonylamino, amino-sulfonyl group, or a C ₁₆ alkyl radical optionally substituted by a group selected from C1-C12 alkoxy , hydroxyl, cyano, carboxy, amino, C1-C4 alkylamino, C1-C4 dialkylamino, or the two alkyl radicals carried by the nitrogen atom of the amino group form a heterocycle comprising from 5 to 7 members and possibly including another heteroatom identical or different to that of the nitrogen atom; preferably R _g and R '_g; R ” _g and R '” _g together form a benzo group; or then two groups R, and R _g ; R '”and R” ” _g ; R ', and RV; and / or R ”, and R” h together form a fused (hetero) cycloalkyl preferably cycloalkyl such as cyclohexyl; or when G represents -NRcRd and G 'represents -NR' _c R ' _d two groups R _c and R'_g; R ' _c and R ” _g ; R _d and R _g ; R ' _d and R' ” _g together form a saturated heteroaryl or heterocycle, optionally substituted by one or more C1-C6 alkyl group, preferably a heterocycle containing one or two heteroatoms chosen from nitrogen and oxygen and comprising between 5 and 7 links; more preferably, the heterocycle is chosen from the morpholinyl, piperazinyl, pyperidinyl and pyrrolidinyl groups; • Ri, R'i, R ”i, and R” 'i, identical or different, represent a hydrogen atom, or a Ci-C ₄ alkyl group; Ri, R2, R3, R4, R'i, R'2, R'3, and R'4, identical or different, represent a hydrogen atom or a Ci-C ₄ alkyl, C1-C12 alkoxy group, hydroxyl, cyano, carboxy, amino, C1-C4 alkylamino, Ci-C. ”dialkylamino, said alkyl radicals being able to form with the nitrogen atom which carry them a heterocyle comprising from 5 to 7 members, optionally comprising another different heteroatom or not nitrogen; preferably Ri, R ₂ , R3, R ₄ , R'i, R'2, R'3, and R ' ₄ are hydrogen atoms, a (Ci-C ₄ ) alkyl or amino group; more preferably Ri, R ₂ , R3, R ₄ , R'i, R'2, R'3, and R ' ₄ represent a hydrogen atom; • T _a , and T _b , identical or different, represent i) either a covalent bond s, ii) either one or more radicals or their combinations chosen from -SO ₂ -, -O-, -S-, -N (R ) -, -N ⁺ (R) (R °) -, -CO-, with R, R °, identical or different, representing a hydrogen atom, a C1-C4 alkyl radical, C1-C4 hydroxyalkyl; or an aryl (Ci-C4) alkyl, preferably Ta is identical to Tb and represent a covalent bond s or a group chosen from -N (R) -, -C (O) -N (R) -, -N (R ) C (O) -, -OC (O) -, -C (O) -O- and -N ⁺ (R) (R °) -, with R, R ° identical or different representing a hydrogen atom or a C1-C4 alkyl group; more preferably T _a and Tb represent a bond; iii) either a heterocycloalkyl or heteroaryl radical, cationic or not, preferentially monocyclic, preferentially identical, preferentially containing two heteroatoms (more preferentially two nitrogen atoms) and preferably comprising from 5 to 7 members such as imidazolium; or identical or different, represent an optionally substituted group; preferably the heterocycles are identical, monocyclic, saturated, and comprise in total two nitrogen atoms and from 5 to 8 members; represent an aryl or heteroaryl group fused to the imidazolium or phenyl ring; or else is absent from the imidazolium or phenyl ring; preferably when the cycle is present the cycle is a benzo; • m, m ’, n and n’, identical or different, represent an integer inclusive between 0 and 6 with m + n, m ’+ rï, identical or different, represents an integer inclusive between 1 and 10; preferably m + n = m ’+ n’ = an integer inclusive between 2 and 4; more preferably m + n = m ’+ ri = an integer equal to 2; • Y represents a hydrogen atom, or a group chosen from: > (Ci-C ₄ ) alkylcarbonyl such as methylcarbonyl or ethylcarbonyl; > arylcarbonyl as phenylcarbonyl; > (Ci-C4) alkoxycarbonyl; > aryloxycarbonyl; > aryl (C1-C4) alkoxycarbonyl; > (di) (C1-C4) (alkyl) aminocarbonyl as dimethylaminocarbonyl; > (Ci-C4) (alkyl) arylaminocarbonyl; > optionally substituted aryl such as phenyl; > 5- or 6-membered monocyclic heteroaryl such as imidazolyl or pyridyl; > cationic 5-6 membered monocyclic heteroaryl such as pyrylium, pyridinium, pyrimidinium, pyrazinium, pyridazinium, triazinium, imidazolium; these groups being optionally substituted by one or more, identical or different, (Ci-C ₄ ) alkyl groups such as methyl; > cationic 8 to 11-membered bicyclic heteroaryl such as benzoimidazolium, or benzoxazolium; these groups being optionally substituted by one or more, identical or different, (C1C ₄ ) alkyl groups such as methyl; > cationic heterocycle of the following formula: > -C (NH2) = N ⁺ H2; Year'"·; with An '”' an anionic counter ion as defined above; > -C (NH ₂ ) = NH; > SO ₃ ', M ⁺ with M ⁺ representing an alkali metal such as sodium or potassium; and • M'representant anionic counterion, derived from organic or mineral acid salt, or from an organic or mineral base ensuring the electroneutrality of the molecule; particularly the disulfide fluorescent dye (s), thiols or protected thiols are chosen from the dyes formulas (Villa), (Vlll’a), (IXa) and (IX’a) as defined above. 7. Method according to any one of the preceding claims, in which the disulfide fluorescent dyes, thiols or protected thiols a) are chosen from 15 colorants formulas (XVIa) or (XVI ”” a) following: R-0 as well as their organic or mineral acid or base salts, its optical, geometric, tautomeric isomers and their solvates such as hydrates, formulas (XVIa) or (XVI ”” a) with: • R 'represents an alkyl group Ci-C _{4 alkyl} substituted with one or more hydroxyl groups, especially by a single hydroxyl group or -C (O) OR' with R 'representing a hydrogen atom, an alkyl group Ci-C ₄ or a group -C (O) -O and in the latter case an anionic counterion An ′ is absent, Preferably R '5 represents an alkyl group Ci-C _{4 alkyl} substituted by a hydroxyl group; • R '2 represents an alkyl group Ci-C _{4 alkyl} optionally substituted by one or more hydroxyl groups; particularly by a single hydroxyl group; more particularly R'1 and R ' ₂ are identical; 10 · Ra, Rb and R _c represent a (Ci-Ce) alkyl group such as methyl, in particular they are in position 3 ', 4' and 5 ', or 2', 4 'and 5' or 2 ', 4 'and 6', preferably they are in position 2 ', 4' and 5 ', • An ^- represents an anionic counter ion as defined above; • B, represent a bond or a divalent amido group -C (O) -N (R) -, -N (R) -C (O) 15, with R representing a hydrogen atom or a group (Ci-Ce ) alkyl; preferably R = H; • n and m, identical or different, represent an integer inclusive between 1 and 4, preferably n is 3 and m is 2; • Y is as defined above; 20 being understood that the bond between the pyridinium ring and the double bond of the ethylene or styryl group is positioned in position 2 or 4 of the pyridinium, preferably in 4. 8. Method according to any one of the preceding claims, in which the or The fluorescent dye (s) disulfide (s), thiol (s) or protected thiol (s) is (are) chosen from the dyes of the following chemical structures: 1 / Z-s \ NOT- \ ♦ Λ_γ ^{Ν =} \ 2M ' 8 HO \ 9 \ ^ S- ^S ^> H \ NOT- ?. Λ / ^{ν =} \ 2M ' - ^ ~~ y ~ \ ^s x ^ ^nh 53 © N —— fi ^ = ⁷ ”Ύ-Ν ^ = / o ^x —x ss θ f ⁼⁼ \ / ---, 2M 'N © _ Γ = \ ^“ Ο ^Ν 0 54 H / \ / \ H N — SS ^ -N ^HO '° o ^x —k oh' x / —Ά, / - fi N— ⁷ \ -N * VX r ~~ \ r- / N —— fi ^ = ⁷ 2 Arr ^ = ⁷ - © ^ -ν HO OH 55 0, - \ / —x O> - N SS N- < ^H ° ._ _{/ λ} ΥΛ · ^ ^Η . 2 An \ = / Χ_θ _, / HO ^Z '' OH 56 \ O— O \ / T \ HH _ „/ ~ A ⁷ ° A = H_ ^ _N - ^ v ^N ^ ss ^ ^N Tr ^ n ^r A ^ 5 = A ⁰ ° 2 Art ° ° 56a ^HO Z — λ JT \ JA \ Af ~ \ A n — e ”- ^{x = /} ^“ ^N / - / o χ HO SS OH '- \,. ° / = \ / -' 2 An- H \ _ _n ^{; =} \ _ ^ V_? ^-N V ^ ^ / OH 57 ^Η ° 'ζ'Α _ ^a ° n-ç ⁼ \ - cr ^OH ^ ~ N ^An 0 H 58 HO OH HO ^ ^OH (Όχ / ι. Ï \ ./? '- TP ^ Cr)> Μ = ^ Ύ M CO, - / ^HO OH ° » 59 ^HO nu \ - ^ H o __,, ^OH N — f V) - _t / ~~ \ ΐ = \ // - h à — N $ \ == ^ y2Ny ° ² % z ^S 'S ^ ^C O ₂ ^E ') no An oh ^An - An- 60 OH ^An 'HO (CH ₂ ) / Nx = \ / ^ 2) 4 (CH ₂ ) ₄ ^Z \ = / WA _' (CH ₂ ) ₄ OH y ~ _N ^ ^ho 0 H An 61 ^HC V \ / ~~ \ K- / / = \ ^OH LA ~ \ 7 \,. CO y / YT = \ /, C fi — N] 'HX P ^s_s K ya <A 62 HO n O V \ / A An- NA / = \ / - ^ ^0H I nA V-, ^An / - / V - = \, ΓΥ /> - n | 0 ^ ~ H An 63 ^HO y- \ AA nA ° A'y ^0H πΑ ^ ΑΑ, θ. y-A AA ^ - ^ Aoh <0 * 64 HO. ZA ^H - / / = \ OH jT n — çA— _ co- / - / ^N ~ y ₊ ^{/ =} \ // - ζ A-tAXT ho YAyy JX-Ao, - VA ^ A A ~ n 0 H 65 OH HO HO SH An75 Me * represents an alkali or% alkaline earth metal; or a methyl HN ^ O -0 Λ f / + Ay s) = NH H, N. ² Year- \ NOT - / JT O ' '-S > = ° Year- 115 116 JT ^- C3 ^{n +} ~ v. -S \ NOT - JT fi + <N- \ -s / \ = / / \ = J > 0 r = < r ° V J Year- Year 117 118 JT / R ~ + -s \ NOT- fi —C N ► s / \ = / ) = O / \ = J y-N -NOT \ at Year- Year- 119 120 with An ^- and M ', identical or different, preferably identical, representing anionic counterions, in particular the anionic counter ion is chosen from halides such as chloride, alkylsulfate such as methylsulfate, mesylate and% (O =) 2SO ² 'or% SO4 ² ', more preferably the disulfide fluorescent dyes, 5 protected thiols, or thioles b) as defined above are chosen from compounds 31, 44, 49, 49bis and 55, 56, 56bis in particular 44, and 56, 56bis. 9. Method according to any one of the preceding claims, in which the fluorescent dye (s) disulfide (s), thiol (s) or thiol (s) protected (s) are present. 10 in a total amount inclusive between 0.001 and 30% by weight, preferably between 0.005 and 5% by weight, better still 0.01% and 2% relative to the total weight of the composition comprising it. 10. Method according to any one of the preceding claims, in which the Or the activating agents comprise i) one or more reducing agents chosen from the compounds of formula (i) below, as well as their addition salts and their mixtures: H _s (X) q (Rlo) t (i) formula ( i), in which, - X represents P, S or SO ₂ , q represents an integer equal to 0 or 1 or 2, preferably 1 or 2 with X = S, - s represents an integer equal to 0 or 1 -1 represents an integer equal to 1 or 2, and - Rio represents an alkyl radical, linear or branched, saturated or unsaturated in C1 to C20, optionally interrupted by a heteroatom, and / or optionally substituted by one or more radicals chosen from hydroxy, halogenated, amine, carboxy, ((Ci -C3o) alkoxy) -carbonyl, amido, ((Ci-C3o) alkyl) -amino carbonyl, (Ci-C3o) acyl) amino, mono or dialkylamino, and mono or dihydroxylamino; in particular, are chosen from those of formulas i-1 and i-2, as well as their acid or base salts, organic or inorganic, their optical isomers, their tautomers, and solvates such as hydrates: R-SH R’-S-R ”i-1 i-2 Formulas i-1 and i-2 in which: • R represents: - a (Ci-C ₈ ) alkyl group, preferably (Ci-Ce) alkyl, linear or branched, optionally substituted, preferably substituted, by one or more groups chosen from carboxy C (O) OH, (di) (Ci -C4) (alkyl) amino, hydroxy -OH, thiol -SH; and / or possibly interrupted by one or more heteroatoms or groups chosen from -O-, and -S-, -N (R ”') -, C (O) or their associations such as -OC (O) -, —C (O) —O—, -N (R '”) - C (O) -, or -C (O) -N (R”') -; with R '”representing a hydrogen atom or a (Ci-Ce) alkyl group; or - a (hetero) aryl group optionally substituted in particular by one or more hydroxy, thiol or carboxy groups; • R ’and R”, identical or different, represent a group (Ci-Cejalkyle, preferably (Ci-Cejalkyle, preferably substituted by one or more groups chosen from hydroxy, thiol, and carboxy; or then R 'and R ”together form with the sulfur atom which carry them a heterocyclic group, comprising from 5 to 7, preferably saturated links, comprising from 1 to 3 heteroatoms, optionally substituted (in particular by one or more groups ( Ci-Ce) alkyl optionally substituted by a group or more hydroxy, thiol or carboxy group), more preferably the heterocyclic group is a dithiolane group optionally substituted by a (Ci-C ₆ ) alkyl group optionally substituted by a group or more carboxy groups , more preferably the reducing agent or agents are chosen from thiolated reducing agents. 11. Method according to any one of the preceding claims, in which the activating agent or agents comprise i) one or more reducing agents comprising at least one mercapto or disulfide group of the invention in particular chosen from thioglycolic acid, thiolactic acid or 2-mercaptopropionic acid, cysteine, cysteamine, homocysteine, glutathione, thioglycerol, thiomalic acid, 3mercaptopropionic acid, thiodiglycol, 2-mercaptoethanol, dithiothreitol, thioxanthine, thiosalicylic acid, thiodiglycolic acid, lipoic acid, / V-acetylcysteine, esters and amides of thioglycolic or thiolactic acids, in particular glycerol monothioglycolate, their salts and mixtures of these compounds; more particularly, the reducing agents comprising at least one mercapto or disulfide group of the invention are chosen from thioglycolic acid, thiolactic acid or 2-mercaptopropionic acid, cysteine, cysteamine, homocysteine, glutathione , thioglycerol, thiomalic acid, 3-mercaptopropionic acid, thiodiglycol, 2mercaptoethanol, dithiothreitol, thioxanthine, thiosalicylic acid, thiodiglycolic acid, lipoic acid, / V-acetyl-cysteine , the esters and amides of thioglycolic or thiolactic acids, in particular glycerol monothioglycolate, their salts and mixtures of these compounds, preferably, the reducing agent (s) i) of the invention are chosen from l thioglycolic acid and its salts, thiolactic acid and its salts, cysteamine and its salts, and their mixtures, more preferably, the reducing agent (s) i) of the invention s have chosen from thioglycolic acid and thiolactic acid and / or their salts. 12. Method according to any one of the preceding claims, in which the activating agent or agents comprise ii) at least two alkaline agents different from each other chosen from (bi) carbonates such as carbonates or bicarbonates of ammonium, sodium or potassium, hydroxides such as ammonium, sodium or potassium hydroxides and silicates, alkanolamines in particular mono-, di- or tri-hydroxy (Ci-C ₆ ) alkylamine such as monoethanolamine, oxyethylenated and / or oxypropylenated ethylenediamines, amino acids, polyamines of the following formula (lb) and their mixtures: N-W-N R, (lb) formula (lb), in which, W is a divalent C1 to C6 alkylene radical optionally substituted by one or more hydroxyl groups or a C1 to C6 alkyl radical, and / or optionally interrupted by one or more heteroatoms such as O, or NR _U ; R _x, R _y, R _z, R _t and R _u are identical or different, represent a hydrogen atom, an alkyl radical Ci-Ce or hydroxyalkyl -C ₆ aminoalkyl or C l -C _6; preferably, the alkaline agents ii) are chosen from (bi) carbonates, in particular ammonium bicarbonate, hydroxides, in particular ammonium hydroxide, mono-, di- or tri-hydroxy (Ci-C ₆ ) alkylamine, such as lamonoethanolamine. 13. Method according to any one of the preceding claims, in which the alkaline agent (s) are present in a total amount ranging from 0.5 to 30% by weight, more preferably from 1 to 20% by weight, better from 5 to 15% by weight relative to the total point of the activating agent b) the container (s). 14. Method according to any one of the preceding claims, in which the activating agent or agents b) comprising ii) at least two different alkaline agents, chosen from the following mixtures: 1) hydroxide (s) + (bi) carbonate (s), particularly hydroxide (s) + bicarbonates, and preferably ammonium hydroxide + ammonium bicarbonate; 2) alkanolamine (s) + (bi) carbonate (s), particularly alkanolamine (s) + bicarbonate (s), and preferably monoethanolamine + ammonium bicarbonate; particularly the number of moles of hydroxides, in particular of ammonium hydroxide contained in the activating agent b) is inclusive between 1. 10 ' ² and 10' ¹ mole, preferably between 2. 10 ' ² and 7.10' ² mole , and preferably between 2.5.10 ^-2 and 4.10 ^-2 mole. 15. Method according to the preceding claim, wherein the ratio R by weight (mass) of 1) (bi) carbonate (s) / hydroxide (s) is greater than or equal to 0.50, preferably R is greater than or equal to 0 , 60, more preferably R is greater than or equal to 0.70, in particular R is inclusive between 1 and 10, more particularly R is inclusive between between 0.60 and 7 and preferably R is inclusive between 1.50 and 5.50; and the ratio R 'by weight of 2) (bi) carbonate (s) / alkanolamine (s) is greater than or equal to 0.50, preferably R' is greater than or equal to 0.70, more preferably R 'is greater than or equal to 0.80, in particular R 'is inclusive between 0.50 and 10, more particularly R' is inclusive between 0.60 and 7 and preferably R 'is inclusive between 0.70 and 5. 16. Method according to any one of the preceding claims, in which the mass ratio of the reducing agent (s) / alkaline agents is inclusive between 0.1 and 3.0 preferably between 0.5 and 2.5 and more particularly between 0 , 7 and 2 or even between 0.8 and 1.5. 17. Method according to any one of the preceding claims, in which the fluorescent dye (s) disulfide (s), thiol (s) or thiol (s) protected (s) a), such (s) as defined in any one of claims 1 to 8, and the activating agent (s) b) as defined in any of claims 9 to 16 are applied jointly to the keratin fibers; preferably the method comprises a step of applying to the keratin fibers a cosmetic composition which comprises one or more fluorescent dye (s) disulfide (s), thiol (s) or thiol (s) protected (s) a), as defined in any of claims 1 to 8, one or more reducing agents i) as defined in any of claims 1, 10, 11 or 16, and at least two alkaline agents different from each other as defined in any one of claims 1, 12 to 16. 18. Method according to any one of claims 1 to 16, which comprises at least the following two successive steps: a first application step on said keratin fibers of a cosmetic composition comprising one or more fluorescent disulfide dyes, thiols or protected thiols a), as defined in any one of claims 1 to 8, followed by - a second stage of application to said fibers of an activating agent b) as defined in any of claims 1 and 10 to 16; or a first stage of application to said keratin fibers of an activating agent b) as defined in any of claims 1 and 10 to 16, followed by a second step of application to said fibers of a cosmetic composition comprising one or more fluorescent disulfide dyes, thiols or thiols protected a), as defined in any one of claims 1 to 8. 19. Method according to any one of the preceding claims, which further comprises the application to said keratin fibers of one or more oxidizing agents applied after application to said keratin fibers of a cosmetic composition comprising one or more fluorescent disulfide dyes, thiols or protected thiols a), as defined in any one of claims 1 to 8, and / or the application to said fibers of an activating agent b) as defined in any one of claims 1 and 10 to 16. 20. Method according to any one of the preceding claims, in which the keratin fibers, in particular human fibers such as the hair, are pretreated with a detergent composition ie comprising at least one anionic and / or amphoteric surfactant, preferably said pretreatment with the composition. detergent is carried out between 1 second and 1 hour, particularly between 1 minute and 30 minutes, more particularly between 5 minutes and 15 minutes, before the application of ingredients a) and b). 21. Method according to any one of the preceding claims, in which the keratin fibers, in particular human fibers such as the hair, are preferably natural keratin fibers with a pitch less than or equal to 6, preferably less than or equal to 4. 22. Method according to any one of claims 1 to 20, in which the keratin fibers, in particular human fibers such as the hair, are bleached keratin fibers in particular with a tone height greater than 6, preferably with a tone height between 7 and 8, more preferably between 8 and 9. 23. Cosmetic composition which comprises one or more fluorescent dye (s) disulfide (s), thiol (s) or thiol (s) protected (a), as defined in any one of claims 1 to 8, one or more reducing agents i) as defined in any one of claims 1, 10, 11 or 16, and at least two different alkaline agents as defined in any of claim 1, 12 to 16, optionally the pH of said composition is inclusive between 7 and 12, preferably between 8 and 11, more preferably between 8.5 and 10.5. 24. Device with several compartments comprising a first compartment containing one or more disulfide fluorescent dyes, thiols or thiols protected a), as defined according to any one of claims 1 to 9; a second compartment containing one or more activating agents b) as defined in any one of claims 1, 10 to 16, and optionally another compartment containing one or more oxidizing agents. 25. Use of one or more direct fluorescent dye (s) thiol (s) or protected thiol (s) a), as defined in any one of the claims 1 to 9, associated with one or more activating agent (s) b) as defined as in any of claims 1 and 10 to 16, for coloring and / or the lightening of dark keratin fibers, in particular human keratin fibers, such as hair with a tone height less than 6, preferably less than or equal to 4, without using an additional dye other than a). 26. Use of one or more direct fluorescent dye (s) thiol (s) or protected thiol (s) a), as defined in any one of the claims 1 to 9, associated with one or more activating agent (s) b) as defined as defined in any of claims 1 and 10 to 16, for the coloring of bleached keratin fibers, in particular with a pitch greater than 6, preferably with a pitch between 7 and 8, more preferably between 8 and 9.