WO2018115355A1

WO2018115355A1 - Process for treating keratin fibres using polyphenols, aldehydes and/or sugars, hydroxides and/or (hydrogen) carbonates and particular metal salts

Info

Publication number: WO2018115355A1
Application number: PCT/EP2017/084225
Authority: WO
Inventors: Francis Pruche; Gwenaëlle JEGOU
Original assignee: L'oreal
Priority date: 2016-12-23
Filing date: 2017-12-21
Publication date: 2018-06-28
Also published as: FR3060983A1

Abstract

Process for treating keratin fibres using polyphenols, aldehydes and/or sugars, hydroxides and/or (hydrogen) carbonates and particular metal salts The present invention relates to a process for treating keratin fibres, in particular human keratin fibres such as the hair, comprising the application, to said fibres, of one or more polyphenols, of one or more aldehydes and/or of one or more sugars, of one or more manganese and/or zinc derivatives, chosen from manganese salts or oxides and zinc salts or oxides, and of one or more hydroxides and/or (hydrogen)carbonates. The present invention also relates to a multi-compartment device suitable for carrying out the invention.

Description

Process for treating keratin fibres using polyphenols, aldehydes and/or sugars, hydroxides and/or (hydrogen) carbonates and particular metal salts

The present invention relates to a process for treating keratin fibres, in particular human keratin fibres such as the hair, comprising the application of one or more polyphenols in combination with one or more aldehydes and/or sugars, one or more manganese and/or zinc derivatives, and one or more hydroxides and/or (hydrogen) carbonates.

Many people have sought for a long time to modify the colour of their hair and in particular to mask their grey hair. Essentially two types of dyeing have been developed for this purpose.

The first type of dyeing is "permanent" or oxidation dyeing, which uses dye compositions containing oxidation dye precursors, generally referred to as oxidation bases. These oxidation bases are colourless or weakly coloured compounds, which, when combined with oxidizing products, may give rise to coloured compounds via a process of oxidative condensation.

It is also known that the shades obtained with these oxidation bases may be varied by combining them with couplers or colour modifiers. The variety of molecules used in the oxidation bases and couplers allows a wide range of colours to be obtained.

Most of these permanent dyeing processes provide a good level of coverage of grey hair. However, they require the presence of an oxidizing agent in a strongly alkaline medium (pH generally of greater than 10) and these conditions are all the harsher, the greater the desired degree of coverage of the grey hairs on the head.

The second type of dyeing is "semi-permanent" dyeing or direct dyeing, which consists in applying direct dyes to the keratin fibres, said dyes being coloured and colouring molecules that have an affinity for the fibres, and then leaving them to take, to allow the molecules to penetrate by diffusion to the interior of the fibre, and then rinsing the fibres.

In order to perform these colourings, the direct dyes generally used are chosen from nitrobenzene, anthraquinone, nitropyridine, azo, xanthene, acridine, azine and triarylmethane direct dyes. The direct dyes may also be natural dyes. The colourings resulting therefrom are particularly chromatic colourings, but are, however, only temporary or semi-permanent since the nature of the interactions that bind the direct dyes to the keratin fibre and their desorption from the surface and/or the core of the fibre are responsible for their weak dyeing power and their poor persistence with respect to washing.

Given these drawbacks, consumers are increasingly seeking dyeing processes other than the conventional oxidation dyeing and direct dyeing processes. Consumers are especially seeking processes which use natural dyes, the use of which is not aggressive for the keratin fibres, and especially which do not require the use of oxidizing agents, but also amine-based agents, and which are more environmentally friendly. Consumers are in particular seeking dyeing methods which are well tolerated and which lead to as natural an appearance as possible.

There is a real need to develop novel processes for dyeing keratin fibres, making it possible to obtain colouring of the hair while overcoming the abovementioned drawbacks. These processes must especially make it possible to cover grey hair.

There is also a need to obtain gradual colouring of grey hair, to avoid an abrupt change in the user's appearance. Gradual colourings must have a natural effect. They must also make it possible to uniformly cover the head of hair.

These processes must also be easy to apply.

The Applicant has discovered, surprisingly, that the use of one or more polyphenols in combination with one or more aldehydes and/or sugars, one or more manganese and/or zinc derivatives, and one or more hydroxides and/or (hydrogen) carbonates, made it possible to achieve the aims set out above.

The aim of the present invention is therefore a process for treating keratin fibres, in particular human keratin fibres such as the hair, comprising the application, to said fibres, of one or more polyphenols, of one or more aldehydes and/or of one or more sugars chosen from monosaccharides and oligosaccharides, of one or more manganese and/or zinc derivatives, chosen from manganese salts or oxides and zinc salts or oxides, and of one or more hydroxides and/or (hydrogen)carbonates.

The process of the invention advantageously comprises:

a) application, to the fibres, of a composition (A) comprising the polyphenol(s), the aldehyde(s) and/or the sugar(s) chosen from monosaccharides and oligosaccharides, and the manganese and/or zinc derivative(s), and b) application, to the fibres, of a composition (B) comprising the hydroxide(s) and/or the (hydrogen) carbonate(s).

The process of the invention also relates to a multi-compartment device comprising at least two compartments containing the respective compositions (A) and (B) above.

The treatment process according to the invention is a dyeing process which makes it possible to obtain a (re-)pigmentation of the keratin fibres, which is both gradual and visible from the first application.

Unlike conventional dyeing processes, the process of the invention makes it possible to produce a real pigmentation or a re-pigmentation of the keratin fibres by returning to the original colour or by providing shades thereto, or else by changing the colour. In the case of grey hair, the process makes it possible to gradually re- pigment the hair, depending on the number of applications. It also makes it possible to prevent or delay the appearance of grey hair.

The process of the invention differs from oxidation dyeing processes because it does not employ the condensation of dye precursors in the presence of an oxidizing agent. It also does not correspond to a direct dyeing process because it does not employ coloured molecules. In particular, the polyphenols used in the present invention are not necessarily coloured molecules, unlike direct dyes. These polyphenols may be coloured but are not persistent on the hair after washing.

The process according to the invention may be applied once.

The process according to the invention may be repeated, which makes it possible to gradually obtain a natural dark, or even black, colouring effect. The process of the invention especially makes it possible to obtain an excellent level of dark pigmentation and good coverage of grey hair from three applications. The repeated applications may take place one after the other or be separated by several hours or even several days.

The process thus makes it possible to obtain good colouring intensity, especially good coverage of grey hair over the whole head of hair, and also good colour homogeneity along the keratin fibres.

Finally, the colourings obtained in this way are not aggressive and are well tolerated by the keratin fibres. The process according to the invention does not damage the keratin fibres and provides them with a good level of conditioning, especially in terms of manageability, softness, smoothness and disentangling. Other subjects, characteristics, aspects and advantages of the invention will emerge even more clearly on reading the description and the examples that follow.

In the text hereinbelow, and unless otherwise indicated, the limits of a range of values are included within that range, especially in the expressions "between" and "ranging from ... to

Moreover, the expressions "at least one" and "at least" used in the present description are equivalent to the expressions "one or more" and "greater than or equal to", respectively.

The term "substituted" or "optionally substituted" is intended to mean conventional substituents of the chemical radicals in question, such as alkyl, amino, aminoalkyl, hydroxyl, hydroxyalkyl, halogenated substituents, etc.

The polyphenols

The process of the invention comprises the application, to the keratin fibres, of one or more polyphenol(s).

These polyphenols are preferably chosen from ortho-diphenols, that is to say compounds comprising one or more aromatic rings, preferably benzene rings, comprising at least two hydroxyl groups (OH) borne by two adjacent carbon atoms of the same aromatic ring. The ortho-diphenol(s) of use in the invention are in particular not auto-oxidizable derivatives, especially auto-oxidizable derivatives with an indole unit. More particularly, they are not 5,6-dihydroxyindole.

The aromatic ring may more particularly be a fused aryl or fused heteroaromatic ring, i.e. optionally comprising one or more heteroatoms, such as benzene, naphthalene, tetrahydronaphthalene, indane, indene, anthracene, phenanthrene, isoindole, indoline, isoindoline, benzofuran, dihydrobenzofuran, chromane, isochromane, chromene, isochromene, quinoline, tetrahydroquinoline and isoquinoline, said aromatic ring comprising at least two hydroxyl groups borne by two adjacent carbon atoms of the aromatic ring. Preferentially, the aromatic ring of the ortho-diphenol derivatives according to the invention is a benzene ring.

"Fused ring" is intended to mean that at least two saturated or unsaturated and heterocyclic or non-heterocyclic rings have a common bond, that is to say that at least one ring is placed side-by-side with another ring.

The ortho-diphenols may or may not be salified. They may also be in the aglycone form (without bonded sugar) or in the form of glycosylated compounds. According to a particularly preferred embodiment, the composition (A) comprises one or more ortho-diphenol(s) of formula (I) below, or an oligomer thereof, in salified or non-salified form:

in which formula (I) the substituents Ri to R₄, which are identical or different, represent:

a hydrogen atom,

- a halogen atom,

a hydroxyl radical,

a carboxyl radical,

an alkyl carboxylate or alkoxycarbonyl radical,

an optionally substituted amino radical,

- an optionally substituted and linear or branched alkyl radical,

an optionally substituted and linear or branched alkenyl radical,

an optionally substituted cycloalkyl radical,

an alkoxy radical,

an alkoxyalkyl radical,

- an alkoxyaryl radical, the aryl group possibly being optionally substituted, an aryl radical,

a substituted aryl radical,

a saturated or unsaturated heterocyclic radical optionally bearing a cationic or anionic charge, optionally substituted and/or optionally fused with an aromatic ring, preferably a benzene ring, said aromatic ring being optionally substituted, in particular with one or more hydroxyl or glycosyloxy groups, a radical containing one or more silicon atoms, or two of the substituents borne by two adjacent carbon atoms (namely Ri and R₂, R₂ and R3 or R3 and R₄) form, together with the carbon atoms bearing them, a saturated or unsaturated and aromatic or non-aromatic ring, optionally containing one or more heteroatoms and optionally fused with one or more saturated or unsaturated rings optionally containing one or more heteroatoms.

Preferably, the ortho-diphenol derivatives of formula (I) are chosen from those in which two adjacent substituents R1-R2, R2 -R3 or R3 -R₄ cannot form, with the carbon atoms which bear them, a cyclic radical, in particular a pyrrolyl radical. More particularly, R₂ and R3 cannot form a pyrrolyl radical fused to the benzene ring bearing the two hydroxyls.

For the purposes of the present invention and unless otherwise indicated: The saturated or unsaturated and optionally fused rings may also be optionally substituted.

The alkyl radicals are saturated, linear or branched, generally C1-C20 and particularly C1-C10 hydrocarbon-based radicals, preferably Ci-C₆ alkyl radicals, such as methyl, ethyl, propyl, butyl, pentyl and hexyl.

The alkenyl radicals are unsaturated, linear or branched, C2-C20 hydrocarbon- based radicals; preferably comprising at least one double bond, such as ethylene, propylene, butylene, pentylene, 2-methylpropylene and decylene. - The aryl radicals are monocyclic or fused or non-fused polycyclic carbon-based radicals, preferentially comprising from 6 to 30 carbon atoms, at least one ring of which is aromatic; the choice is preferentially made, from the aryl radical, of a phenyl, biphenyl, naphthyl, indenyl, anthracenyl and tetrahydronaphthyl. The alkoxy radicals are alkyl-oxy radicals with alkyl as defined previously, preferably C1-C10, such as methoxy, ethoxy, propoxy and butoxy.

The alkoxyalkyl radicals are preferably (Ci-C₂o)alkoxy(Ci-C₂o)alkyl radicals, such as methoxymethyl, ethoxymethyl, methoxyethyl, ethoxy ethyl, etc.

The cycloalkyl radicals are generally C₄-Cs cycloalkyl radicals, preferably the cyclopentyl and cyclohexyl radicals. The cycloalkyl radicals can be substituted cycloalkyl radicals, in particular substituted with alkyl, alkoxy, carboxylic acid, hydroxyl, amine and ketone groups.

The ortho-diphenols of use in the process of the invention can be natural or synthetic. The natural ortho-diphenols include the compounds which may be present in nature and which are reproduced by chemical (semi)synthesis. According to a particular embodiment of the invention, the process comprises the application of one or more synthetic ortho-diphenol(s) that do not exist in nature.

According to another preferred embodiment of the invention, the ortho- diphenols are natural ortho-diphenols.

More particularly, the natural ortho-diphenols of use in the process of the invention are chosen from:

- flavanols, such as catechin and epicatechin gallate,

- flavonols, such as quercetin,

- anthocyanidins, such as cyanidin, delphinidin, petunidin or pelargonidin,

- anthocyanins or anthocyans such as delphinidin 3-O-glucoside, also referred to as myrtillin,

- ortho-hydroxybenzoates, for example gallic acid derivatives, and in particular gallates, for example propylgallate,

- flavones, such as luteolin,

- 3,4-dihydroxyphenylalanine and the derivatives thereof, such as L-3,4-dihydroxyphenylalanine methyl ester hydrochloride,

- 2,3-dihydroxyphenylalanine and the derivatives thereof, - 4,5-dihydroxyphenylalanine and the derivatives thereof,

- dihydroxycinnamates, such as caffeic acid and chlorogenic acid,

- ortho-polyhydroxycoumarins,

- ortho-polyhydroxyisocoumarins,

- ortho-polyhydroxycoumarones,

- ortho-polyhydroxyisocoumarones,

- ortho-polyhydroxychalcones,

- ortho-polyhydroxychromones,

- quinones,

- hydroxyxanthones,

- 1 ,2-dihydroxybenzene and the derivatives thereof,

- 1,2,4-trihydroxybenzene and the derivatives thereof,

- 1,2,3-trihydroxybenzene and the derivatives thereof,

- 2,4,5-trihydroxytoluene and the derivatives thereof,

- proanthocyanidins and especially the proanthocyanidins Al, A2, Bl, B2, B3 and Cl,

- proanthocyanins, - tannic acid,

- ellagic acid,

- ortho-dihydroxy-l,2-diphenylethylenes such as Black Sho Wu, extracted from the roots of Radix Polygonum Multigonia,

- and mixtures of the preceding compounds,

and more particularly from catechin, quercetin, brazilin (CAS 474-07-7), haematein, haematoxylin, chlorogenic, caffeic and gallic acids, catechol, L DOPA, pelargonidin, cyanidin, (-)-epicatechin, (-)-epigallocatechin, (-)-epigallocatechin 3- gallate (EGCG), (+)-catechin, isoquercetin, pomiferin, esculetin, 6,7-dihydroxy-3-(3- hydroxy-2,4-dimethoxyphenyl)coumarin, santalin AC, mangiferin, butein, maritimetin, sulfuretin, robtein, betanidin, pericampylinone A., theaflavin, proanthocyanidin A2, proanthocyanidin B2, proanthocyanidin CI, procyanidins DP 4-8, tannic acid, purpurogallin, 5,6-dihydroxy-2-methyl-l,4-naphthoquinone, alizarin, wedelo lactone, variegatic acid, gomphidic acid, xerocomic acid, carnosol, ortho-dihydroxy- 1 ,2-diphenylethylene and the natural extracts containing same.

Preferentially, the ortho-diphenol(s) according to the invention are chosen from flavanols, flavonols, ortho-hydroxybenzoates, isoflavones and neoflavones.

According to one embodiment, the natural ortho-diphenols are derived from, or are introduced in the form of, extracts of animals, bacteria, fungi, algae, plants and fruits, used in their entirety or partially. In particular regarding plants, the extracts are derived from fruits, including citrus fruits, from vegetables, from trees, from shrubs and lichen. Use may also be made of mixtures of these extracts rich in ortho- diphenols as defined above.

Preferably, the ortho-diphenol(s) are natural ortho-diphenols derived from extracts of plants or plant parts. These extracts of plants or plant parts may be used directly in the process of the invention.

The extracts are obtained by extraction of various plant parts, for instance the root, the wood, the bark, the leaf, the flower, the fruit, the seed, the pod or the peel.

Among the plant extracts, mention may be made of extracts of tealeaf, rose, or Black Sho Wu derived from the roots of Radix Polygonum Multigonia.

Mention may be made, among the extracts of fruit, of extracts of apple, extracts of grape (in particular of grape seed) or extracts of cocoa beans and/or pods. Mention may be made, among the extracts of vegetables, of extracts of potato or of onion peel.

Mention may be made, among the extracts of tree wood, of extracts of pine bark and extracts of logwood.

Use may also be made of mixtures of plant extracts.

According to a particular embodiment of the invention, the ortho- diphenol(s) are natural extracts rich in ortho-diphenols. According to a preferred embodiment, the ortho-diphenol derivative(s) are solely contained in natural extracts.

Preferentially, the polyphenol(s) used in the process according to the invention are chosen from catechin, quercetin, haematein, haematoxylin, brazilin, gallic acid, and natural extracts containing same, chosen especially from grape marc, pine bark, green tea, onion, cocoa bean, logwood, redwood and gall nut. More preferentially, the extract used is logwood.

More preferentially still, the polyphenol(s) are chosen from catechin, quercetin, gallic acid and haematoxylin.

The natural extracts containing the polyphenols according to the invention may be in the form of powders or liquids. Preferably, the extracts containing the polyphenols according to the invention are in the form of powders.

According to the invention, the synthetic or natural polyphenol(s) and/or the natural extract(s) containing same preferably represent(s) from 0.001% to 20% by weight of the total weight of composition (A).

As regards the pure polyphenol(s), the content thereof in the composition (A) is generally between 0.001 and 10% by weight relative to the total weight of the composition (A), preferably between 0.1 and 5% by weight.

As regards the extracts, the content of extract in the composition (A) is preferably between 0.1 and 20% by weight relative to the total weight of the composition (A).

According to a particularly preferred embodiment, the process according to the invention does not employ oxidation dyes or direct dyes other than the polyphenols described above.

The aldehydes

The aldehydes used in the process of the invention are preferably chosen from aromatic aldehydes, that is to say compounds comprising one or more aromatic rings and one or more aldehyde functions. These compounds are preferably chosen from those comprising an aromatic ring bearing one or more free aldehyde functions -COH.

These compounds may be of natural or synthetic origin. They are preferably of natural origin, or are naturally occurring. They may in particular be introduced in the form of an essential oil containing same.

The aldehydes of use in the invention are chosen for example from the following compounds:

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

By way of preferred compounds, mention may be made of vanillin and derivatives thereof, ethylvanillin and derivatives thereof, aldehyde derivatives of vitamin B6, dihydroxybenzaldehyde derivatives, furfuraldehyde-based derivatives, and benzaldehyde derivatives.

By way of derivatives, structures substituted by an alkyl, hydroxyl, hydroxyalkyl, amino, aminoalkyl, carboxylic, benzene radical, etc., are meant in particular.

The particularly preferred aromatic aldehydes are chosen from vanillin and derivatives thereof, furfuraldehyde and derivatives thereof, and benzaldehyde and derivatives thereof. Particularly preferably, vanillin and derivatives thereof are employed. he sugara

As is known per se, the term "sugar" means oxygen-bearing hydrocarbon- based compounds bearing several alcohol functions, with or without aldehyde or ketone functions, and which comprise at least 4 carbon atoms. The sugars are chosen from monosaccharides and oligosaccharides.

An oligosaccharide is an oligomer, which means a compound comprising from 2 to 5 repetitive units or monomelic units, and preferably 2 or 3. In other words, the term "oligosaccharide" is intended to mean a compound comprising from 2 to 5 repetitive units or monosaccharide units, and preferably 2 or 3.

Examples of suitable sugars that may be mentioned include sucrose (or saccharose), fructose, maltose, cellobiose, glucose, ribose, lactose, trehalose, 29

arabinose, and derivatives thereof, in particular alkyl derivatives, such as methyl derivatives, for instance methylglucose. Maltose is preferably employed.

These compounds may be of natural or synthetic origin. They are preferably of natural origin, or are naturally occurring. They may be present in the plant extracts containing same.

According to a preferred embodiment, the process of the invention uses one or more aldehydes and one or more sugars chosen from monosaccharides and oligosaccharides, preferably included in the composition (A).

The aldehyde(s) and/or the sugars may be present in a total amount ranging from 0.01 to 10% by weight, preferably from 0.1 to 5% by weight, relative to the weight of the composition (A).

Manganese and/or zinc derivatives

The process of the invention also comprises the application of one or more manganese (Mn) and/or zinc (Zn) derivatives, chosen from the salts or the oxides.

These manganese and/or zinc derivative(s) are preferably contained in the composition (A).

For the purposes of the present invention, "salts" are intended to mean actual salts in the ionized form. These salts may be solvated, in particular hydrated.

The derivatives are preferably salts.

Particularly, the derivatives of the invention are in oxidation state II, such as Mn(II) and Zn(II).

The manganese and/or zinc salt(s) are advantageously chosen from chlorides, fluorides, iodides, bromides, sulfates, phosphates, nitrates, perchlorates, carbonates, carboxylates, and mixtures thereof.

The carboxylates of use in the invention also include carboxylic acid salts comprising one or more hydroxyl radicals such as gluconates.

By way of example of carboxylates, mention may be made, for example, of acetate, tartrate, lysinate, glutamate, lactate, glycinate, aspartate, stearate, acetylacetate.

The manganese and zinc derivatives can be introduced in the solid form into the compositions or else can be introduced in the form of an aqueous solution, such as a natural, mineral or spring water which is rich in these ions or else of seawater (Dead Sea water, especially). They can also originate from mineral compounds, such 30

as earths, ochres, such as clays (for example green clay), or even from plant extracts containing them (cf, for example, the document FR 2 814 943).

Among the manganese salts, preference is given to manganese chloride, manganese carbonate, manganese difluoride, manganese acetate tetrahydrate, manganese lactate trihydrate, manganese phosphate, manganese iodide, manganese nitrate trihydrate, manganese bromide, manganese perchlorate tetrahydrate, manganese sulfate monohydrate, manganese gluconate, manganese glycinate and mixtures thereof.

Among the zinc salts, preference is given to zinc sulfate, zinc gluconate, zinc chloride, zinc lactate, zinc acetate, zinc glycinate, zinc aspartate and mixtures thereof.

Preferably, the process of the invention employs one or more manganese salts, in particular Mn(II) metal salts.

Even more preferentially, the manganese salt(s) are chosen from manganese carboxylates, especially manganese gluconate, and manganese halides, such as manganese chloride, and mixtures thereof.

Better still, the manganese salt(s) are chosen from manganese chloride, manganese gluconate and mixtures thereof.

When the composition (A) comprises one or more manganese derivatives, the total concentration of said derivative(s) in the composition (A) preferably ranges from 10^"3 to 10^"1 mmol.l^"1, and more preferentially from 10^"2 to 10^"1 mmol.l^"1.

When the composition (A) comprises one or more zinc derivatives, the total concentration of said derivative(s) in the composition (A) ranges from 5.10^"2 to 10 mmol.l^"1, and more preferentially from 5.10^"1 to 1 mmol.l^"1.

The (hydrogen) carbonates

The (hydrogen) carbonate(s) able to be used in the process of the invention are especially chosen from the compounds of the following formulae:

- R'⁺, HCO3^" with R' representing a hydrogen atom, an alkali metal, an ammonium R"₄N⁺- or phosphonium R"₄P⁺- group, in which the groups R", which are identical or different, represent a hydrogen atom, an optionally substituted (Ci- C₆)alkyl group such as hydroxyethyl; when R' represents a hydrogen atom, the hydrogen carbonate is then referred to as dihydrogen carbonate (CO2, H₂0); and

- Met'²⁺ (HCC"3^")2 with Met' representing an alkaline earth metal. 31

More particularly, the (hydrogen) carbonates are chosen from alkali metal hydrogen carbonates, alkaline earth metal hydrogen carbonate(s), ammonium hydrogen carbonates and the mixtures thereof; and more preferentially from alkali metal hydrogen carbonates, alkaline earth metal hydrogen carbonates and the mixtures thereof.

Better still, the hydrogen carbonates are chosen from sodium, potassium, magnesium and calcium hydrogen carbonates and the mixtures thereof, and in particular sodium hydrogen carbonate and potassium hydrogen carbonate. Even more preferentially, the hydrogen carbonate used in the process of the invention is sodium hydrogen carbonate.

These (hydrogen) carbonates may originate from a natural water, for example spring water from the Vichy basin or from La-Roche-Posay or Badoit water (cf. for example, patent document FR 2 814 943). Mention may particularly be made of sodium carbonate Na₂CC"3, sodium hydrogen carbonate or sodium bicarbonate NaHCOs.

These hydrogen carbonates may also be generated in situ by any process making it possible to generate an HCO3^" salt.

The hydroxides

The hydroxide(s) able to be used in the process of the invention are especially chosen from the following hydroxides: sodium, potassium and calcium hydroxides. Calcium hydroxide is preferentially used.

The total amount of the (hydrogen) carbonate(s) and/or hydroxide(s) used in the process according to the present invention preferably ranges from 0.5% to 30% by weight and more preferentially from 1% to 15% by weight relative to the total weight of the composition (B).

The metal salts other than the manganese and zinc salts

The process according to the present invention may also comprise the application, to the keratin fibres, of one or more additional divalent or trivalent metal salt(s) other than the manganese salts and zinc salts defined above.

For the purposes of the present invention, "metal salt" is intended to mean actual salts, that is to say in ionized form, of the metals of columns 3 to 14 of the periodic table of the elements, other than manganese and zinc. 32

Among these additional metal salts, mention may especially be made of hydroxides, halides, sulfates, phosphates, nitrates and carboxylates.

The additional metal salt(s) are preferably chosen from iron(II) salts and iron(III) salts.

More preferentially, the additional metal salt(s) are chosen from iron sulfate, iron fumarate, iron gluconate, iron glycinate, iron acetylacetonate, iron oxalate, mixed salts, such as Mohr's salt, and the mixtures thereof; and better still, iron sulfate.

The metal salts, in particular the iron salts, may be obtained and used from natural extracts such as plants or microorganisms such as bacteria or fungi. By way of examples of iron salts obtained from natural extracts, mention may be made of lentils or spinach.

According to a first preferred embodiment, the additional metal salt(s) are present in the composition (A).

According to a second preferred embodiment, the additional metal salt(s) are present in a composition (C) separate from the compositions (A) and (B), and applied thereafter.

It is also possible to combine these two embodiments, and to use the additional metal salt(s) both in the composition (A) and in a separate composition (C).

When they are used, the total amount of the additional metal salt(s) preferably ranges from 0.001% to 5% by weight and more preferentially from 0.01% to 4% by weight relative to the total weight of the composition containing same. The proteins

The process of the invention may also comprise the application, to the keratin fibres, of one or more proteins.

The latter are preferably chosen from natural proteins, such as especially albumins, globulins, prolamins, glutenins, lactoglobulins, lactalbumins, caseins, glycinins, β-conglycinins.

These proteins may or may not be partially hydrolysed.

They are preferably derived from natural products, for example lactoserum, hemp, pea, oat, wheat, bulgur, soy, rice, quinoa or sorghum. 33

The protein(s) are preferably present in a composition (C) separate from the compositions (A) and (B), and applied thereafter.

The application of the protein(s) to the fibres is preferably accompanied by a heat treatment of said fibres, generally carried out by means of a heated tool.

The heated tool may in particular be chosen from a hairstyling hood, a straightening iron (or flat irons), a hairdryer and an infrared-ray dispenser. The heated tool is preferably an infrared-ray dispenser.

The step of heat treatment is generally carried out at a temperature ranging from 40 to 250°C, preferably ranging from 40 to 200°C, and more preferentially from 60 to l60°C.

Surfactants

The compositions of use for the invention may optionally comprise one or more surfactants.

The surfactant(s) of use are preferably chosen from nonionic surfactants, anionic surfactants and amphoteric or zwitterionic surfactants.

The total amount of surfactant(s) present in the compositions according to the invention may range from 0.1 to 30% by weight, and preferably from 0.5 to 20% by weight relative to the total weight of each composition containing same.

The compositions

The compositions used in the present invention may be in any form which is compatible with an application to keratin fibres, and especially the hair.

In particular, the compositions (A), (B) and, where appropriate, (C) and (C) of use in the invention may be in the form of liquid or powder compositions.

According to a preferred embodiment, the compositions (A), (B) and, where appropriate, (C) and (C) are in the form of liquid compositions such as solutions.

They may be aqueous solutions, in particular aqueous-alcoholic solutions. They generally comprise water or a mixture of water and of one or more solvents, for example chosen from the lower Ci to C₄ alcohols, such as ethanol, isopropanol, tert- butanol or n-butanol; polyols such as glycerol, propylene glycol and polyethylene glycols; and the mixtures thereof. 34

When they are present, the total amount of the solvent(s) preferably ranges from 0.01% to 50% by weight and more preferentially from 0.05% to 30% by weight relative to the weight of each composition containing same.

When the composition which contains the metal salt(s) is in the form of a solution, the latter must not flocculate. Those skilled in the art will choose the suitable pH to prevent flocculation of the composition, as a function of the metal salt.

When it is aqueous, the composition (A) has an acid pH, preferably ranging from 3 to 7. When it is aqueous, the composition (B) has a rather basic pH, preferably between 7.1 and 9.5. When it is aqueous, the composition (C) has a rather acid pH, ranging from 2 to 7, preferably from 3 to 4.

The compositions used in the invention can also contain one or more oils.

The term "oil" is intended to mean any fatty substance that is in liquid form at ambient temperature (25°C) and at atmospheric pressure. (1.013 x 10⁵ Pa).

The term "fatty substance" is intended to mean an organic compound that is insoluble in water at ambient temperature (25°C) and at atmospheric pressure (1.013x l0⁵ Pa) (solubility of less than 5% by weight, preferably less than 1% by weight and even more preferably less than 0.1% by weight). They bear in their structure at least one hydrocarbon-based chain comprising at least 6 carbon atoms and/or a sequence of at least two siloxane groups. In addition, the fatty substances are generally soluble in organic solvents under the same temperature and pressure conditions, for instance chloroform, dichloromethane, carbon tetrachloride, ethanol, benzene, toluene, tetrahydrofuran (THF), liquid petroleum jelly or decamethy Icy clopentasilo xane .

The oils suitable for the invention may be chosen from hydrocarbon-based oils, silicone oils and fluoro oils, and mixtures thereof, and preferably from hydrocarbon-based oils.

For the purposes of the present invention, the term "silicone oil" means an oil comprising at least one silicon atom, and especially at least one Si-0 group.

The term "hydrocarbon-based oil" means an oil mainly containing hydrogen and carbon atoms. A hydrocarbon-based oil may also optionally comprise oxygen, nitrogen, sulfur and/or phosphorus atoms, for example in the form of hydroxyl, amine, amide, ester, ether or acid groups, and in particular in the form of hydroxyl, ester, ether or acid groups.

The term "fluoro oil" means an oil comprising at least one fluorine atom. 35

The hydrocarbon-based oils suitable for the invention may be more particularly chosen from animal oils, plant oils, mineral oils and synthetic oils. Preference is most particularly given to oils of natural origin, such as animal oils, plant oils, mineral oils and mixtures thereof.

A hydrocarbon-based oil of animal origin that may be mentioned is perhydrosqualene.

The plant oils may for example be chosen from sunflower seed oil, corn oil, soybean oil, marrow oil, grapeseed oil, sesame seed oil, hazelnut oil, apricot oil, macadamia nut oil, arara oil, castor oil, avocado oil, tea seed oil, passion seed oil, meadowfoam seed oil, jojoba oil, shea butter oil or argan oil.

The natural mineral oils may be chosen from paraffin oils, petroleum jelly, and liquid petroleum jelly.

Plant oils are most particularly preferred.

According to a preferred embodiment of the invention, the composition (B) contains one or more oils as described above. In this embodiment, the composition (B) may be in the form of an oily dispersion, of an oil-in-water or water-in-oil emulsion, or of an oily composition containing no water. According to a particular embodiment, the composition (B) is in the form of an oily dispersion, or an oil-in- water or water-in-oil emulsion.

The additives

The compositions of use in the invention may comprise one or more additives, among which mention may be made of cationic, anionic, nonionic and amphoteric polymers or the mixtures thereof, thickeners, anti-dandruff agents, antiseborrheic agents, agents for preventing hair loss and/or promoting hair regrowth, vitamins and provitamins including panthenol, sunscreens, sequestrants, plasticizers, solubilizers, acidifying agents, opacifiers or nacreous agents, hydroxy acids, fragrances, preserving agents, or fillers, preferentially of natural origin. As fillers, mention may be made of pigments such as iron oxides derived from ochres, carbon black, chlorophyll or polymerized anthocyanins.

The above additives may be present in an amount, for each of them, of between 0 and 20% by weight relative to the total weight of each composition containing same, in the case of a liquid composition. 36

The above additives may be present in an amount, for each of them, of between 0 and 80% by weight relative to the total weight of each composition containing same, in the case of a solid composition. The process

When the process according to the present invention is carried out starting with the compositions (A), (B) and where appropriate (C) and/or (C) described above, these compositions are applied to dry or wet keratin fibres and preferably to wet keratin fibres.

According to a preferred embodiment, the composition (A) then the composition (B) are applied successively.

According to this embodiment, the process more preferentially comprises:

- according to a first variant, the application, to the keratin fibres, of the composition (A), then of the composition (B); preferably with a time gap between the application of the composition (A) and of the composition (B) which may vary from 30 seconds to 1 hour, preferably from 1 min to 30 min;

- according to a second variant, the application, to the keratin fibres, of the extemporaneous mixture of the composition (A) and of the composition (B), that is to say that the mixture of the compositions (A) and (B) is immediately applied to the fibres, without intermediate storage;

- according to a third variant, the application, to the keratin fibres, of a composition resulting from the mixing of the composition (A) with the composition (B), kept, before application to the fibres, in a container which does not contain oxygen.

In the latter two variants, oxygen in the air acts directly on the hair at the moment of application. This embodiment makes it possible to reduce the number of steps to be carried out.

According to the particular embodiment which uses one or more additional metal salts as defined above, present in a composition (C) separate from the compositions (A) and (B), the three compositions (A), (B) and (C) are applied successively to the keratin fibres.

According to this embodiment, the composition (C) is applied after the composition (B) or before the composition (A), preferably with a time gap between the application of the compositions (A) and (B), as defined above. 37

According to the particular embodiment which uses one or more proteins as defined above, present in a composition (C) separate from the compositions (A) and (B), the three compositions (A), (B) and (C) are applied successively to the keratin fibres.

According to this embodiment, the composition (C) is applied to the keratin fibres after the composition (B), then a heat treatment of said fibres is carried out, as described above.

Each of the compositions (A), (B), or the composition resulting from the mixing thereof, and the compositions (C) and (C), where appropriate, are advantageously left in place on the keratin fibres for a duration ranging from 30 seconds to 1 hour, and more preferentially from 30 seconds to 30 minutes.

The process of the present invention may be repeated several times, especially from 2 to 50 times, preferably from 3 to 30 times, depending on the desired degree of colouring. The greater the number of applications, the more intense and the darker is the colouring, thereby improving the re-pigmentation of grey hair.

Advantageously, the process of the invention is carried out by re-applying the compositions (A), (B) and optionally (C) and/or (C) several times, to obtain, over time, a natural and visible colouring. For example, the compositions according to the invention may be applied after each shampooing operation, or for example once or twice per week.

The process of the invention may also comprise a step of rinsing after the application of the compositions (A) and (B) or after application of the compositions (A), (B) and (C) or (C).

More preferentially, the process comprises a single final rinsing step. In other words, the keratin fibres are only rinsed after the application of the final composition.

Device

Finally, the present invention relates to a multi-compartment device comprising:

a first compartment containing the composition (A) as defined above;

a second compartment containing the composition (B) as defined above.

According to another embodiment of the device, the latter contains a compartment comprising a composition resulting from the mixing of the composition (A) with the composition (B), this compartment not containing oxygen. 38

The device according to the present invention may also optionally comprise a third compartment containing a composition (C) containing one or more additional metal salts or a composition (C) containing one or more proteins, as described above.

The compositions of the compartments are intended to be applied successively to the keratin fibres according to the process as described above.

The examples that follow serve to illustrate the invention without, however, being limiting in nature. EXAMPLES

In all the examples below, the colour of the locks was evaluated in the CIE L*a*b* system, using a Minolta Spectrophotometer CM2600D colorimeter.

In this L*a*b* system, the three parameters respectively denote the intensity of the colour (L*), the green/red colour axis (a*) and the blue/yellow colour axis (b*). The lower the value of L*, the darker or more highly intense the colour. The higher the value of a*, the redder the colour and the higher the value of b*, the yellower the colour. In the examples which follow, unless indicated otherwise, all the amounts are shown as percentage by weight relative to the total weight of each composition.

Example 1 :

The compositions Al and El are prepared from the following ingredients:

Ingredients Al El

Logwood extract*

30 mg 30 mg

Maltose 50 mg -

MnCl₂

(in the form of 10 mM/1 1 ml 1 ml

aqueous solution)

Water 1 ml 1 ml 39

* extract containing 35% by weight of haematoxylin

The composition Bl was prepared by dissolving KHCO3 at a concentration of 10% by weight in water.

The composition Al or the composition El was then applied in combination with the composition Bl, according to the protocol below, to locks of Caucasian hair (90%o grey), washed beforehand.

Protocol for an application:

The composition Al or El was first applied by means of a brush at an amount of 2 g of composition Al or El on a 1 g lock. The lock was then left to stand at 50°C for 30 minutes (hood heating).

An identical amount of composition Bl was then applied, namely 2 g per 1 g lock. The lock was then left to stand at 50°C for 30 minutes (hood heating).

After cooling, the locks of hair were rinsed with water, washed by means of

0.4 g of a commercially available shampoo (DOP camomile), and dried.

The shampooing operation was repeated once, 5 times or 10 times on the locks.

It is observed that the locks of hair are dyed an intense shade of dark purple. The coloration is very resistent to washing and light.

The colour of the locks obtained was evaluated in the CIE L*a*b* system, using a Minolta Spectrophotometer CM2600D colorimeter. The tables below represent the colouring intensity values obtained:

40

These results demonstrate that, with the composition of the invention which contains a sugar (maltose), the keratin fibres are dyed more intensely and this colour withstands shampooing operations well, since it is observed that the colour is maintained in the fibres, even after 10 shampooing operations.

Example 2:

The compositions A2, A'2, E2 and F2 were prepared from the following ingredients:

* Extract containing 35% by weight of haematoxylin

The composition Bl employed is identical to that of example 1 (KHCO3 at a concentration of 10% by weight in water).

Each of the compositions A2, A'2, E2 and F2 was then applied in combination with the composition Bl to locks of Chinese hair (100% grey), washed beforehand, following the protocol described in example 1.

It is observed that the locks of hair A2 and A'2 are dyed an intense shade of dark purple, much darker than that obtained with the composition F2 or E2. The 41

colouring obtained with the compositions A2 and A'2 is very resistant to washing and to light.

The colour of the locks obtained was evaluated in the CIE L*a*b* system, using a Minolta Spectrophotometer CM2600D colorimeter.

The tables below represent the colouring intensity values obtained:

A slight intensification of the colour over time is also observed. Example 3 :

The compositions A3, A'3 and A"3 were prepared from the following

Ingredients A3 A'3 A"3

Logwood extract (1) 1% 0.5% 1.5%

Vanillin 1.5% 1.5% 1.5%

Maltose 2.5% 2.5% 2.5% 42

(1) Extract containing 35% by weight of haematoxylin

(2) Solution prepared by weighing 197 mg of MnCb into a conical flask and adding 100 ml of distilled water The composition B2 was prepared by mixing, per 100 g of composition B2:

3 g of Ca(OH)₂, 14.2 g of an aqueous solution of sodium lauryl ether sulfate at 10% by weight of active material (i.e. 10 g of sodium lauryl ether sulfate ) and 82.8 g of avocado oil. The avocado oil makes it possible to obtain an oily dispersion of lime.

The composition B3 was prepared by mixing, per 100 g of composition B3 : 90 ml of an aqueous solution of NaHC0₃ at 8% by weight and 10 g of sodium lauryl ether sulfate.

The composition A3, A'3 or A"3 was then applied in combination with the composition B2, according to the protocol below, to locks of Chinese hair (100% grey), washed beforehand.

Protocol for an application:

The composition A3, A'3 or A"3 was firstly applied by means of a brush at an amount of 1 ml of composition on a 0.5 g lock. The lock was then left to stand at ambient temperature for 5 minutes.

Then the composition B2 was applied in an identical amount, namely 1 ml of composition per 0.5 g lock. The lock was then left to stand at ambient temperature for 5 minutes.

The locks of hair were rinsed with water, washed by means of a commercially available shampoo (DOP camomile), and dried.

The colour of the locks obtained was evaluated in the CIE L*a*b* system, using a Minolta Spectrophotometer CM2600D colorimeter. The tables below represent the colouring intensity values obtained: 43

Composition A3 :

Composition A' 3 :

Composition A" 3 :

The composition A"3 was also applied in combination with the composition B3, according to the protocol below, to locks of Chinese hair (100% grey), washed beforehand.

Protocol for an application:

The composition A"3 was firstly applied by means of a brush at an amount of 1 ml of composition on a 0.5 g lock. The lock was then left to stand at ambient temperature for 5 minutes.

Then the composition B3 was applied in an identical amount, namely 1 ml of composition per 0.5 g lock. The composition was foamed up on the lock by rubbing it for 3 minutes, then the lock was rinsed with water. 44

The tables below represent the colouring intensity values obtained: Composition A" 3 :

The above results show that the process according to the present invention makes it possible to darken the hair from the first applications.

Example 4:

The compositions A4 and A'4 were prepared from the following ingredients:

The composition B2 was prepared by mixing, per 100 g of composition B2:

3 g of Ca(OH)₂, 14.2 g of an aqueous solution of sodium lauryl ether sulfate at 10% by weight of active material (i.e. 10 g of sodium lauryl ether sulfate ) and 82.8 g of avocado oil. 45

The composition CI was prepared by mixing, per 100 g of composition CI : 0.3 g of iron sulfate, 1.5 g of guar gum, and 98.2 g of water. The composition A4 or A'4 was then applied in combination with the compositions B2 and CI, according to the protocol below, to locks of Chinese hair (100% grey) or of Caucasian hair, washed beforehand.

Protocol for an application:

The composition A4 or A'4 was firstly applied by means of a brush at an amount of 2 g of composition on a 1 g lock. The lock was then left to stand at 45°C for 30 minutes.

An identical amount of composition B2 was then applied, namely 2 g of composition per lock. The lock was then left to stand at 45°C for 30 minutes.

The locks of hair were then rinsed with water and washed by means of 0.4 g of a commercially available shampoo (DOP camomile).

An identical amount of composition CI was then applied, namely 2 g of composition per lock. The lock was massaged for 3 minutes then rinsed with water.

The colour of the locks obtained was evaluated after dyeing in the CIE L*a*b* system, using a Minolta Spectrophotometer CM2600D colorimeter.

The resistance of the locks to sweat, washing and light was then evaluated in the following way:

- Resistance to washing:

The locks are washed 5 times by means of a commercially available shampoo (DOP camomile). The locks are rinsed with water after each wash.

The lock is then dried and colorimetric measurements are carried out again by means of the Minolta Spectrophotometer CM2600D colorimeter. - Resistance to sweat:

The 1 g dyed lock is submerged in a closed vial containing 20 ml of artificial sweat. This is left to incubate for 48 hours at 37°C. The lock is removed, rinsed, and dried.

Composition of the artificial sweat: 46

- sodium chloride: 0.5 g

- lactic acid: 0.1 g

- pure urea: 0.1 g

- albumin: 0.1 g

- pure water: q.s. 100 g

- ammonium hydroxide: q.s. pH 6.5

Colorimetric measurements are then carried out again by means of the Minolta Spectrophotometer CM2600D colorimeter.

- Resistance to light:

The locks dyed using the compositions described above were exposed to light according to the following protocol:

The dyed locks are exposed to light using a Xenotest 150S machine from the company Atlas at an average lighting level from a 1600 watt xenon UV lamp. The humidity level is set at 60%. The exposure time is 2 hours 40 minutes.

The colour of the hair before and after exposure is measured.

The tables below represent the colouring intensity values obtained:

Composition A4: results on Chinese hair (100% grey)

Composition A'4: results on Chinese hair (100% grey) or on Caucasian hair 47

These results show that the process according to the invention, in which an additional composition (C) containing a metal salt is also applied, makes it possible to obtain excellent resistance of the dyeing to sweat, washing and light.

Example 5 :

This test was carried out using the compositions A4 and B2 described in example 4.

The composition C2 was also used, which is a solution of albumin at 10% by weight in water.

The compositions were applied in the following way to locks of Chinese hair (100% grey), washed beforehand.

Protocol 1 :

The composition A4 was firstly applied by means of a brush at an amount of 2 g of composition on a 1 g lock. The lock was then left to stand at 45°C for 30 minutes. 48

Protocol 2:

Protocol 1 is carried out, then after washing the locks with shampoo, the composition C2 is applied at an amount of 2 g of composition per lock, and the lock is massaged for 3 minutes. A heat treatment is then carried out on the lock, by passing a straightening iron 3 times at 150°C (duration of each passage of the iron over the lock = 15 seconds). The lock is then washed and dried.

The resistance of the locks to sweat was also evaluated using the test described in example 4.

The table below represents the colouring intensity values obtained:

These results show that the process according to the invention, in which an additional composition C containing a protein is also applied, with a heat treatment of the locks also being carried out, makes it possible to obtain excellent resistance of the dyeing to sweat. 49

Example 6:

The compositions A6, A'6 and A"6 were prepared from the following

(1) Extract containing 35% by weight of haematoxylin

(2) Solution prepared by weighing 197 mg of MnCb into a conical flask and adding 100 ml of distilled water

The composition B3 was prepared by mixing, per 100 g of composition B3: 90 ml of an aqueous solution of NaHCCb at 8% by weight and 10 g of sodium lauryl ether sulfate.

Protocol for an application:

The composition A6, A'6 or A"6 was firstly applied by means of a brush at an amount of 1 ml of composition on a 0.5 g lock. The lock was then left to stand at 45°C for 30 minutes.

Then the composition B3 was applied in an identical amount, namely 1 ml of composition per 0.5 g lock. The composition was foamed up on the lock by rubbing it for 30 minutes at 45°C, then the lock was rinsed with water.

The locks were then washed several times (5 shampoo washes), to evaluate the washing resistance of the coloration thus obtained. 50

Com osition A6:

Com osition A' 6:

Com osition A" 6:

The results obtained above show that the process according to the present invention makes it possible to darken the hair from the first application and that the colour thus obtained withstands shampooing operations well, since it is observed that the colour is maintained in the fibres, even after 5 shampooing operations. 51

Example 7:

The compositions A7 and A'7 were prepared from the following

(1) Extract containing 35% by weight of haematoxylin

The composition B3 was prepared by mixing, per 100 g of composition B3: 90 ml of an aqueous solution of NaHC0₃ at 8% by weight and 10 g of sodium lauryl ether sulfate.

Protocol for an application:

The composition A7 or A'7 was firstly applied by means of a brush at an amount of 1 ml of composition on a 0.5 g lock. The lock was then left to stand at 45°C for 30 minutes.

The locks were then washed several times (5 shampoo washes), to evaluate the washing resistance of the coloration thus obtained.

The colour of the locks obtained was evaluated in the CIE L*a*b* system, using a Minolta Spectrophotometer CM2600D colorimeter. The tables below represent the colouring intensity values obtained: 52

Composition A7:

Composition A' 7:

The results obtained above show that the process according to the present invention makes it possible to darken the hair from the first application and that the colour thus obtained withstands shampooing operations well, since it is observed that the colour is maintained in the fibres, even after 5 shampooing operations.

Example 8:

The compositions A8.1 to A8.6, according to the present invention, and the comparative composition C8.1 to C8.6 were prepared from the following ingredients:

Ingredients A8.1 C8.1 A8.2 C8.2

Catechin 1.5% 1.5% - -

Quercetin - - 1.5% 1.5%

Vanillin 1.5% - 1.5% -

Maltose 2.5% - 2.5% -

MnCl₂ solution (1) 43.7 ml 43.7 ml 43.7 ml 43.7 ml

Sodium lauryl ether sulfate 5% 5% 5% 5%

Q.s 100% Q.s 100% Q.s 100% Q.s 100%

Water

by weight by weight by weight by weight 53

(1) Solution prepared by weighing 197 mg of MnCb into a conical flask and adding 100 ml of distilled water

The composition B3 was prepared by mixing, per 100 g of composition B3: 90 ml of an aqueous solution of NaHC0₃ at 8%> by weight and 10 g of sodium lauryl ether sulfate.

Protocol for an application:

Each of the composition A8.1-A8.6 and C8.1-C8.6 thus obtained was firstly applied by means of a brush at an amount of 1 ml of composition on a 0.5 g lock. The lock was then left to stand at 45°C for 30 minutes. 54

The colour of the locks obtained was evaluated in the CIE L*a*b* system, using a Minolta Spectrophotometer CM2600D colorimeter. The tables below represent the colouring intensity values obtained: Compositions 8.1 :

Compositions 8.2:

Compositions 8.3:

55

Compositions 8.4

Compositions 8.5:

Compositions 8.6:

Claims

51 CLAIMS

1. Process for treating keratin fibres, comprising the application, to said fibres, of one or more polyphenols, of one or more aldehydes and/or of one or more sugars chosen from monosaccharides and oligosaccharides, of one or more manganese and/or zinc derivatives, chosen from manganese salts or oxides and zinc salts or oxides, and of one or more hydroxides and/or (hydrogen) carbonates.

2. Process according to Claim 1, characterized in that it comprises:

a) application, to the fibres, of a composition (A) comprising the polyphenol(s), the aldehyde(s) and/or the sugar(s), and the manganese and/or zinc derivative(s), and b) application, to the fibres, of a composition (B) comprising the hydroxide(s) and/or the (hydrogen) carbonate(s).

3. Process according to either one of the preceding claims, characterized in that the polyphenols are chosen from ortho-diphenols, that is to say compounds comprising one or more aromatic rings, preferably benzene rings, comprising at least two hydroxyl groups (OH) borne by two adjacent carbon atoms of the same aromatic ring.

4. Process according to either one of Claims 2 and 3, characterized in that the composition (A) comprises one or more ortho-diphenol(s) of formula (I) below, or an oligomer thereof, in salified or non-salified form:

wherein the substituents Ri to R₄, which are identical or different, represent:

- a hydrogen atom,

- a halogen atom,

- a hydroxyl radical,

- a carboxyl radical, 52

- an alkyl carboxylate or alkoxycarbonyl radical,

- an optionally substituted amino radical,

- an optionally substituted and linear or branched alkyl radical,

- an optionally substituted and linear or branched alkenyl radical,

- an optionally substituted cycloalkyl radical,

- an alkoxy radical,

- an alkoxyalkyl radical,

- an alkoxyaryl radical, the aryl group possibly being optionally substituted,

- an aryl radical,

- a substituted aryl radical,

- a saturated or unsaturated heterocyclic radical optionally bearing a cationic or anionic charge, optionally substituted and/or optionally fused with an aromatic ring, preferably a benzene ring, said aromatic ring being optionally substituted, in particular with one or more hydroxyl or glycosyloxy groups,

- a radical containing one or more silicon atoms,

or two of the substituents borne by two adjacent carbon atoms (namely Ri and R₂, R₂ and R₃ or R₃ and R₄) form, together with the carbon atoms bearing them, a saturated or unsaturated and aromatic or non-aromatic ring, optionally containing one or more heteroatoms and optionally fused with one or more saturated or unsaturated rings optionally containing one or more heteroatoms.

5. Process according to any one of the preceding claims, characterized in that the polyphenol(s) are chosen from catechin, quercetin, haematein, haematoxylin, brazilin, gallic acid, and the natural extracts containing same.

6. Process according to any one of the preceding claims, characterized in that the polyphenol(s) are introduced in the form of one or more natural extracts containing same, chosen from grape marc, pine bark, green tea, onion, cocoa bean, logwood, redwood and gall nut, and preferably logwood.

7. Process according to any one of Claims 2 to 6, characterized in that the polyphenol(s) are present in the composition (A), with a content of pure polyphenol(s) of between 0.001 and 10% by weight, preferably between 0.1 and 5% by weight, relative to the total weight of the composition (A).

8. Process according to any one of the preceding claims, characterized in that the aldehyde(s) are chosen from aromatic aldehydes, and preferably from those 53 comprising an aromatic ring bearing one or more free aldehyde functions -COH.

9. Process according to any one of the preceding claims, characterized in that the aldehyde(s) are chosen from vanillin and derivatives thereof, ethylvanillin and derivatives thereof, aldehyde derivatives of vitamin B6, dihydroxybenzaldehyde derivatives, furfuraldehyde-based derivatives, and benzaldehyde derivatives; preferably from vanillin and derivatives thereof, furfuraldehyde and derivatives thereof, and benzaldehyde and derivatives thereof; and more preferentially from vanillin and derivatives thereof.

10. Process according to any one of the preceding claims, characterized in that the sugar(s) from sucrose, fructose, maltose, cellobiose, glucose, ribose, lactose, trehalose, arabinose, and the derivatives thereof, especially alkyl derivatives, and more preferentially maltose.

11. Process according to any one of Claims 2 to 10, characterized in that the aldehyde(s) and/or sugar(s) are present in a total amount ranging from 0.01 to 10% by weight, preferably from 0.1 to 5% by weight, relative to the weight of the composition (A).

12. Process according to any one of the preceding claims, characterized in that the manganese and/or zinc derivative(s) are chosen from manganese or zinc salts, preferably chlorides, fluorides, iodides, bromides, sulfates, phosphates, nitrates, perchlorates, carbonates, carboxylates, and mixtures thereof.

13. Process according to any one of the preceding claims, characterized in that it uses one or more Mn(II) salts, preferably chosen from manganese carboxylates, manganese halides and mixtures thereof, and more preferentially from manganese chloride, manganese gluconate and mixtures thereof.

14. Process according to any one of Claims 2 to 13, characterized in that the composition (A) comprises one or more manganese derivatives in a total concentration ranging from 10^"3 to 10^"1 mmol.l^"1, and preferably from 10^"2 to 10^"1 mmol.l^"1.

15. Process according to any one of Claims 2 to 12, characterized in that the composition (A) comprises one or more zinc derivatives in a total concentration ranging from 5.10^"2 to 10 mmol.l^"1, and preferably from 5.10^"1 to 1 mmol.l^"1.

16. Process according to any one of the preceding claims, characterized in that the (hydrogen) carbonate(s) are chosen from the compounds of the following formulae: 54

- Met'²⁺ (HCO3 2 with Met' representing an alkaline earth metal;

and preferably from alkali metal hydrogen carbonates, alkaline earth metal hydrogen carbonates, ammonium hydrogen carbonates and the mixtures thereof; and more preferentially from alkali metal hydrogen carbonates, alkaline earth metal hydrogen carbonates and the mixtures thereof.

17. Process according to any one of the preceding claims, characterized in that the hydroxide(s) are chosen from sodium, potassium and calcium hydroxides, and preferably calcium hydroxide.

18. Process according to any one of Claims 2 to 17, characterized in that the total amount of (hydrogen) carbonate(s) and/or hydroxide(s) ranges from 0.5% to

30% by weight, preferably from 1% to 15% by weight relative to the total weight of the composition (B).

19. Process according to any one of the preceding claims, characterized in that it also comprises the application, to the keratin fibres, of one or more additional divalent or trivalent metal salt(s) other than the manganese salts and zinc salts, preferably chosen from iron(II) salts and iron(III) salts.

20. Process according to any one of the preceding claims, characterized in that it also comprises the application, to the keratin fibres, of one or more proteins, preferably chosen from natural proteins, such as especially albumins, globulins, prolamins, glutenins, lactoglobulins, lactalbumins, caseins, glycinins, β-conglycinins.

21. Process according to the preceding claim, characterized in that the application of the protein(s) to the fibres is accompanied by a heat treatment of said fibres at a temperature ranging from 40 to 250°C, preferably ranging from 40 to 200°C, and more preferentially from 60 to 160°C.

22. Process according to any one of Claims 2 to 21, characterized in that the composition (B) comprises one or more oils, preferably chosen from oils of natural origin such as animal oils, plant oils, mineral oils and mixtures thereof; preferably plant oils; and more preferentially the composition (B) is in the form of an oily dispersion or a water-in-oil or oil-in- water emulsion. 55

23. Process according to any one of Claims 2 to 22, characterized in that it comprises:

- the application, to the keratin fibres, of the composition (A), then of the composition (B); or

- the application, to the keratin fibres, of the extemporaneous mixture of the composition (A) and of the composition (B); or

- the application, to the keratin fibres, of a composition resulting from the mixing of the composition (A) with the composition (B), kept, before application to the fibres, in a container which does not contain oxygen.

24. Process according to the preceding claim, characterized in that it comprises:

- the application of a composition (C) comprising one or more additional metal salts, applied after the composition (B) or before the composition (A); and/or

- the application of a composition (C") comprising one or more proteins, applied to the keratin fibres after the composition (B), then a heat treatment of said fibres.

25. Multi-compartment device comprising:

- a first compartment containing the composition (A) as defined in any one of Claims 2 to 15; and

- a second compartment containing the composition (B) as defined in any one of Claims 2, 16 to 18 and 22, and

- optionally, a third compartment containing a composition (C) containing one or more additional metal salts or a composition (C) containing one or more proteins.