WO2014102256A2

WO2014102256A2 - Method for hair colouring employing a chromene or chroman dye and an alum

Info

Publication number: WO2014102256A2
Application number: PCT/EP2013/077946
Authority: WO
Inventors: Boris Lalleman
Original assignee: L'oreal
Priority date: 2012-12-27
Filing date: 2013-12-23
Publication date: 2014-07-03
Also published as: FR3000387A1; FR3000387B1; WO2014102256A3

Abstract

The present invention provides a method for colouring human keratin fibres, more particularly the hair, comprising the application to the said fibres of: (a) a dyeing composition comprising one or more dyes chosen from chromene dyes and chroman dyes, and (b) a composition comprising one or more alums and/or the hydrates thereof; the composition (b) being applied after the composition (a), or the compositions (a) and (b) being applied simultaneously in the form of a single dyeing composition (C), and in which the dyeing composition (a) and/or (C) comprises one or more liquid organic compounds having a Hansen solubility parameter δΗ of less than or equal to 16 Mpa^1/2. The present invention additionally provides a composition and a kit which are appropriate for the implementation of this method.

Description

METHOD FOR HAIR C OLOURING EMPLOYING A CHROMENE OR CHROMAN DYE AND AN ALUM The present invention relates to a method for colouring human keratin fibres that comprises applying to the said fibres one or more dyes chosen from chromene dyes and chroman dyes, in combination with one or more alums . The invention also pertains to a composition which is appropriate for the implementation o f such a method, and to a kit containing such a composition.

It is familiar art to dye human keratin fibres, and more particularly the hair, with dyeing compositions containing oxidation dye precursors, referred to generally as oxidation bases, such as ortho- or para-phenylenediamines, ortho- or para-aminopheno ls and heterocyclic compounds. These oxidation bases are generally combined with couplers. These bases and couplers are colourless or weakly coloured compounds, which, when combined with oxidizing products, may give rise to co loured compounds by a process of oxidative condensation. This type o f co louring by oxidation results in permanent colourations, but causes degradation o f the human keratin fibres as a result o f the use of oxidizing agents .

It is also known art to dye human keratin fibres, and more particularly the hair, with dyeing compositions comprising direct dyes. The conventional dyes which are used are, in particular, nitrobenzene, anthraquinone, nitropyridine, azo , xanthene, acridine, azine and triarylmethane dyes or natural dyes. These dyes are coloured or co louring mo lecules which have a certain affinity for human keratin fibres.

The compositions comprising one or more direct dyes are applied to the human keratin fibres for a time required for the desired co louration to be obtained, and are then rinsed. The resulting co lourations are particularly chromatic colourations which are, however, temporary or semi-permanent in nature, since the type of interactions that bond the direct dyes to the keratin fibre, and their desorption from the surface and/or core of the fibre, are responsible for their low dyeing power and for their poor resistance to washing or to perspiration.

There is, moreover, increasing demand for hair colouring methods that use natural products.

A genuine need therefore exists to develop hair colouring methods that lead to powerful, bright colourations of low selectivity, which are resistant to external agents (such as, among others, light, adverse weather, shampoos, perspiration), respecting the nature o f the hair, on the basis o f compositions containing natural dyes .

Also increasingly demanded are colouring methods which yield such results in a satisfactory way without the need to employ chemical oxidizing agents .

These objectives are achieved by the present invention, which provides a method for co louring human keratin fibres, and more particularly the hair, comprising the application to the said fibres of:

(a) a dyeing composition comprising one or more dyes chosen from chromene dyes and chroman dyes, and

(b) a composition comprising one or more alums and/or the hydrates thereof;

the composition (b) being applied after the composition (a), or the compositions (a) and (b) being applied simultaneously in the form of a single dyeing composition (C), and

in which the dyeing composition (a) and/or (C) comprises one or more liquid organic compounds having a Hansen solubility parameter δΗ of less than or equal to 1 6 Mpa 1 /2

The present invention additionally provides a dyeing composition and a device comprising a plurality o f compartments, or dyeing kit, which is appropriate for the implementation o f the method according to the invention.

Other features, aspects and advantages of the present invention will emerge from a reading o f the detailed description that is to fo llow.

The dyes used in the method according to the invention are dyes chosen from chromene dyes and chroman dyes . According to the invention, the terms "chromene dye" and "chroman dye" mean dyes which comprise in their structure at least one bicyclic system o f formula (A) below :

A where the endocyclic bond represents a carbon-carbon single bond or else a carbon-carbon double bond, as illustrated by formula A l , denoting the class o f the chromenes, and by formula A2, denoting the class o f the chromans below:

Al A2

The dyes o f formula (A) are chosen more particularly from the compounds o f formulae below:

(i) the compounds of formula (I), comprising in their structure the bicyclic system o f formula A2,

in which:

- represents a carbon-carbon single bond or a carbon-carbon double bond, the sequence of these bonds denoting two carbon- carbon single bonds and two carbon-carbon double bonds, the said bonds being conjugated,

- X represents a group:

// /

HO— C or 0=C

\ \

- R¹, R², R³, R⁴, R⁵ and R⁶, which are identical or different, represent, independently of one another, a hydrogen atom, a hydroxyl group, an optionally substituted alkyl or optionally substituted alkoxy group, or an optionally substituted acyloxy group,

and also the tautomeric and/or mesomeric forms thereof, the stereoisomers thereof, the addition salts thereof with a cosmetically acceptable acid or base, and the hydrates thereof, and

(ii) the compounds of formula (II), comprising in their structure the bicyclic system of formula Al:

in which:

-Rii, Ri2, Ri3, Ri6, Ri and R₂o, which are identical or different, represent, independently of one another, a hydrogen atom or a C₁-C4 alkyl radical,

-Ri4, Ri5, Ri7 and Ris, which are identical or different, represent, independently of one another, a hydrogen atom, a hydroxyl radical or a C₁-C₄ alkoxy radical,

and also the tautomeric and/or mesomeric forms thereof, the stereoisomers thereof, the addition salts thereof with a cosmetically acceptable acid or base, and the hydrates thereof.

With regard to the compounds of formula (I) as defined above, they may be in two tautomeric forms, labelled (la) and (lb):

The alkyl radicals referred to in the above definitions of the substituents are generally C₁-C₂₀, particularly C₁-C₁₀ and preferably Ci- C₆, linear or branched, saturated hydrocarbon radicals, such as methyl, ethyl, propyl, butyl, pentyl and hexyl.

The alkoxy radicals are alkyl-oxy radicals with the alkyl radicals as defined above, and the alkoxy radicals are preferably C₁-C₁₀ radicals, such as methoxy, ethoxy, propoxy and butoxy.

The alkyl or alkoxy radicals, when they are substituted, may be substituted with at least one substituent borne by at least one carbon atom, chosen from:

a halogen atom;

a hydroxyl group;

a C₁-C₂ alkoxy radical;

a C₁-C₁₀ alkoxycarbonyl radical;

a (poly)-hydroxy-C2-C4 alkoxy radical;

an amino radical;

a 5- or 6-membered heterocycloalkyl radical;

an optionally cationic, 5- or 6-membered heteroaryl radical, preferably imidazolium, which is optionally substituted by a (C₁-C₄) alkyl radical, preferably methyl;

an amino radical substituted by one or two identical or different C i -C₆ alkyl radicals which optionally bear at least:

* one hydroxyl group,

* an amino group optionally substituted by one or two optionally substituted C ₁ - C3 alkyl radicals, it being possible for the said alkyl radicals, with the nitrogen atom to which they are attached, to form a heterocycle comprising from 5 to 7 chain members, which is saturated or unsaturated and is optionally substituted, optionally comprising at least one other heteroatom the same as or different from nitrogen,

* a quaternary ammonium group -N R' R " R ' " , M^" for which R' , R " and R' " , which are identical or different, represent a hydrogen atom or a C ₁ -C₄ alkyl group; and M^" represents the counterion of the corresponding organic or inorganic acid or the halide,

* or a 5 - or 6-membered heteroaryl radical which is optionally cationic, preferably imidazolium, and is optionally substituted by a (C i - C₄) alkyl radical, preferably methyl;

an acylamino radical (-NR- COR' ) in which the radical R is a hydrogen atom or a C ₁ - C₄ alkyl radical which optionally bears at least one hydroxyl group, and the radical R ' is a C ₁ -C₂ alkyl radical;

a carbamoyl radical ((R)₂N-CO-) in which the radicals R, which are identical or non-identical, represent a hydrogen atom or a C i - C₄ alkyl radical optionally bearing at least one hydroxyl group;

an alkylsulfonylamino radical (R' S0₂-NR-) in which the radical R represents a hydrogen atom or a C ₁ -C₄ alkyl radical optionally bearing at least one hydroxyl group, and the radical R' represents a C i - C₄ alkyl radical or a phenyl radical;

an aminosulfonyl radical ((R)₂N-S0₂-) in which the radicals R, which are identical or non-identical, represent a hydrogen atom or a C ₁ -C₄ alkyl radical which optionally bears at least one hydroxyl group;

a carboxyl radical in acid or salified form (preferably salified with an alkali metal or a substituted or unsubstituted ammonium);

a cyano group; a nitro group;

a carboxyl or glycosylcarbonyl group;

a phenylcarbonyloxy group which is optionally substituted by one or more hydroxyl groups;

a glyco syloxy group; and

a phenyl group which is optionally substituted by one or more hydroxyl groups.

The term " glycosyl radical" means a radical derived from a monosaccharide or polysaccharide.

Preferably, the alkyl or alkoxy radicals of formula (I) are unsubstituted.

According to one particular embodiment of the invention, the compounds o f formula (I) comprise a radical R⁶ which represents a hydroxyl group .

Another particular embodiment of the invention concerns the compounds o f formula (I) for which the radical R¹ represents a hydrogen atom or a hydroxyl group .

More particularly, the method for colouring keratin fibres employs, in the composition (a), one or more dyes o f formula (I) chosen from haematoxylin, haematein, brazilin and brazileine.

Brazileine is a conjugated form o f a chroman compound o f formula A2. The tautomeric structures (la) and (lb) illustrated above are found in the scheme below.

Brazileine

The haematoxylin/haematein and brazilin/brazileine compounds include, by way o f examp le, haematoxylin (Natural Black 1 according to the INCI naming) and brazilin (Natural Red 24 according to the INCI naming), which are compounds from the class of the indochromans, and are available commercially. These compounds may exist in an oxidized form and may be obtained synthetically or by extraction from plants or vegetables known to be rich in these compounds.

The compounds of formula (I) may more particularly be used in the form of extracts. Use may be made of the fo llowing plant extracts (genus and species) : Haematoxylon campechianum, Haematoxylon brasiletto, Caesalpinia echinata, Caesalpinia sappan, Caesalpinia spinosa, and Caesalpinia brasiliensis.

The extracts are obtained by extracting the various plant parts, for instance the root, the wood, the bark or the leaves .

According to one particular embodiment of the invention, the natural compounds of formula (I) are derived from logwood, pernambuco wood, sappan wood and brazilwood.

With regard to the compounds of formula (II), the compounds used in the present invention are preferably those for which Rn and R represent an alkyl radical, preferably methyl.

Preferably, R12 , Ri 6 , R19 and R20 denote, independently o f one another, a hydrogen atom or an alkyl radical, preferably methyl.

Preferably, R14 and R17 denote, independently o f one another, a hydrogen atom or an alkoxy radical, preferably methoxy.

Preferably, Ri s and R1 5 denote, independently o f one another, a hydrogen atom, a hydroxyl radical or an alkoxy radical, preferably methoxy.

A first particularly preferred class of compounds suitable for the present invention is that of the compounds conforming to formula (II) above for which Ri ₂, R1 5 , Ri 6 , R1 7 , R19 and R₂o each represent a hydrogen atom. Rn and R13 each represent a methyl radical, and R14 represents a methoxy radical.

The preferred compounds from this first class include those for which Ri s represents a methoxy radical (santalin B) or a hydroxyl radical (santalin A) .

A second particularly preferred class of compounds suitable for the present invention is that o f the compounds conforming to formula (II) above for which:

-Rn and R13 each represent a methyl radical, -Ri7 represents the methoxy radical.

One preferred compound from this second class is that for which, additionally, R19 represents a methyl radical, R₂o, R12, R14, Ri8 and Ri₆ each represent a hydrogen atom, and R15 represents the hydroxyl radical (santarubin A).

A second preferred compound from this second class is that for which Ri8, R20, R12, Ri4 and Ri₆ represent a hydrogen atom, R15 represents a methoxy radical, and R19 represents a methyl radical (santarubin B).

A third preferred compound from this second class is that for which R₂₀, R12, Ri4, Ri5, Ri6 and R19 represent hydrogen and Ris represents the hydroxyl radical (santarubin C).

Another preferred compound from this second class is that for which Ris represents a methoxy radical, and Ris and R14 represent a hydrogen atom, and R₂o, R12, Ri6 and R19 represent a methyl radical (tetra-O-methylcantarubin).

The compounds of formula (II) may be used more particularly in the form of extracts. Use may be made of the plant extracts of red woods, generally encompassing the Asian and West African red wood species of the Pterocarpus genus and of the Baphia genus. These woods are, for example, Pterocarpus santalinus, Pterocarpus osun, Pterocarpus soyauxii, Pterocarpus erinaceus, Pterocarpus indicus or else Baphia nitida. These woods may also be called padauk, sandalwood, narrawood, camwood or else barwood.

Accordingly, extracts that can be used in the present invention, containing compounds of formula (II), may be obtained, for example, from red sandalwood {Pterocarpus santalinus), by aqueous basic extraction, such as the product sold under the trade name Santal Concentre SL 709C by the company Copiaa, or else by means of a solvent extraction of sandalwood powder, such as the product sold under the trade name Santal Poudre SL PP by the same company, Copiaa. Also included is the aqueous-alcoholic extract of red sandalwood in powder form, from the company Alban Muller. Extracts also suitable for the present invention may be obtained from woods such as camwood (Baphia nitida) or else barwood {Pterocarpus soyauxii, Pterocarpus erinaceus) ; the latter is thus fractionated and then ground; a conventional alcoho lic extraction or an extraction by perco lation is then carried out on this ground material, to give a pulverulent extract which is particularly suitable for the implementation o f the present invention.

The salts of the compounds o f formula (I) and (II) of the invention may be salts o f cosmetically acceptable acids or bases.

The acids can be inorganic or organic . Preferably, the acid is hydrochloric acid, which results in chlorides.

The bases can be inorganic or organic. In particular, the bases are alkali metal hydroxides such as sodium hydroxide, which leads to sodium salts.

The compound or compounds of formula (I) and/or (II) that are employed in the method according to the invention are preferably derived from plant extracts . Use may also be made of mixtures of plant extracts .

The natural extracts according to the invention can be provided in the form o f powders or liquids . The extracts of the invention are preferably in powder form.

The chromene or chroman dyes used are preferably chosen from haematein, haematoxylin, brazileine, brazilin, santalin A and mixtures thereo f. More preferably still, preference is given to using the dyes of formula (I), and especially haematein, haematoxylin, brazileine, brazilin, and mixtures thereo f.

In an especially preferred variant, haematoxylin, brazilin or mixtures thereof will be used.

The method according to the invention preferably employs a composition comprising from 0.001 % to 20%> by weight of dyes chosen from the chromene dyes and the chroman dyes, relative to the total weight of the dyeing composition (a) or (C), preferably from 0.01 % to 10%) by weight, and more preferably still from 0. 1 % to 5 % by weight. In the present description, the term "dyeing composition (a) or (C)" denotes :

- either the dyeing composition (a) alone, when the two compositions (a) and (b) are separate, with the composition (b) being applied after the composition (a);

- or the composition (C), when the two compositions (a) and (b) are applied in the form o f one single dyeing composition (C) .

Similarly, any reference to the "composition (b) or (C)" denotes :

- either the composition (b) alone, when the two compositions (a) and (b) are separate, with the composition (b) being applied after the composition (a);

The method according to the invention employs a composition (b) comprising one or more alums or their hydrates.

An alum in the present invention denotes a mixed sulfate o f aluminium and a monovalent cation, conforming to the formula:

MA1(S0₄)₂

in which M denotes a monovalent cation.

M is preferably chosen from potassium, sodium and ammonium ions.

Accordingly, in one preferred embodiment, the alum or alums are chosen from aluminium potassium sulfate (potassium alum), aluminium sodium sulfate (sodium alum) and aluminium ammonium sulfate (ammonium alum) .

The method according to the invention preferably employs a composition (b) or (C) comprising from 0. 1 % to 20% by weight o f alum(s) and/or the hydrates thereof, relative to the total weight of the said composition, preferably from 0.5 %> to 10%> by weight, and more preferably still from 1 % to 5 % by weight.

The compositions (a), (b) and (C) as defined above and employed in the method according to the invention may independently o f one another be in diverse formulational forms, such as a powder, a lotion, a foam or mousse, a cream, a gel, or in any other form appropriate for carrying out dyeing of human keratin fibres . They may also be packaged in a pump dispenser without propellant or under pressure in an aeroso l dispenser in the presence of a propellant and form a foam or mousse.

These compositions advantageously comprise water, a mixture of water and one or more organic solvents or else a mixture of organic so lvents, when the composition is in liquid form.

According to one particular embodiment of the invention, the composition or compositions (a), (b) and/or (C) comprise water.

Organic so lvents include, for example, lower C 1 - C 4 alkanols, such as ethano l and isopropano l; polyols and polyo l ethers such as 2- butoxyethanol, propylene glycol, propylene glycol monomethyl ether, diethylene glycol monoethyl ether and monomethyl ether, and hexylene glyco l.

According to the present invention, the composition (a) and/or the composition (C) comprises one or more liquid organic compounds having a Hansen so lubility parameter δΗ of less than or equal to 16 Mpa^{1 /2}, preferably strictly less than 16 Mpa^{1 /2}.

When the compositions (a) and (b) are applied separately, the composition (a) comprises one or more liquid organic compounds having a Hansen so lubility parameter δΗ of less than or equal to 16 Mpa 1 /2

When the compositions (a) and (b) are applied simultaneously in the form o f a single dyeing composition (C), this or these liquid organic compounds having a Hansen so lubility parameter δΗ of less than or equal to 16 Mpa 1 /2 may be present in one and/or the other of the compositions (a) and (b), such that the composition (C) resulting from the mixing of the compositions (a) and (b) comprises at least one such organic compound.

These compounds are liquid at a temperature of 25 °C and at atmospheric pressure (760 mmHg) .

The organic compound or compounds having a Hansen solubility parameter δΗ as defined in the present invention are described in, for example, the reference work "Hansen solubility parameters A user's handbook, Charles M . Hansen", CRC Press, 2000 , pages 167 to 1 85 , or else in "Handbook of So lubility Parameters and other cohesion parameters", CRC Press, pages 95 to 121 and pages 177 to 1 85.

This so lubility parameter δΗ is associated with the formation of hydrogen bonds.

More particularly, "Handbook of Solubility Parameters and other cohesion parameters", CRC Press, pages 95 to 121 and pages 177 to 1 85 , gives the equation δΗ = (∑-^zU_h/V) ^{1 /2}

in which:

zU_h (in J.mo l^{" 1} ) describes the contributions of the functional group in question in the so lubility parameters linked to the hydrogen bonds (values in table 14, page 1 83); this parameter ^zU_h is also described in the fo llowing work: "The relation between surface tension and so lubility parameter in liquids", Bagda, E, Farbe Lack, 84, 212, 1978 ; and V is the vo lume o f the mo lecule.

The value of the so lubility parameter δΗ is usually given for a temperature of 25 ° C .

The said liquid organic compound or compounds may be chosen from alkano ls, aliphatic esters, ethers, aromatic alcoho ls, alkylaryl alcoho ls, aromatic acids, aliphatic acids, alkylene carbonates such as propylene carbonate, lactones such as γ-butyro lactone, and mixtures thereo f.

The said liquid organic compound or compounds are preferably chosen from benzyl alcoho l, phenylpropanol, phenylethano l, phenoxyethano l, linear alcoho ls containing from 5 to 12 carbon atoms (and, among the latter, more preferably pentanol, octanol, decanol, and mixtures thereof), and mixtures thereof.

The said liquid organic compound or compounds may be present in proportions preferably ranging from 1 % to 40% by weight, relative to the total weight of the dyeing composition (a) and/or (C), and more preferably from 2% to 20% by weight.

According to another embodiment of the invention, at least one of the compositions used in the method of the invention is anhydrous and may be in a pulverulent or pasty form. When the composition is in pulverulent form, it may contain pulverulent ingredients.

When the composition is in the form o f a paste, it may optionally contain one or more inert organic liquids, preferably chosen from liquid petrolatum, polydecenes and fatty esters which are liquid at ambient temperature (25 °C) and at atmospheric pressure (760 mmHg, or 1 .013 bar) .

According to one embodiment of the invention, the composition or compositions (a), (b) and/or (C) comprise one or more additional, non-alum metal salts and/or metal oxides .

The metal oxide or oxides and/or salt or salts are preferably chosen from the salts and/or oxides of zinc, manganese, iron and copper.

The salts are particularly preferred. The salts include the halides such as chlorides, fluorides and iodides; sulfates and phosphates; nitrates; perchlorates and carboxylic salts and po lymeric salts, and also mixtures thereof.

Carboxylic salts which may be used in the invention also include hydroxycarboxylic salts such as gluconate, or amino carboxylic salts such as glycinate .

Examples o f po lymeric salts include manganese pyrrolidonecarboxylate.

Non-limiting examples of manganese salts include manganese chloride, manganese fluoride, manganese acetate tetrahydrate, manganese lactate trihydrate, manganese phosphate, manganese iodide, manganese nitrate trihydrate, manganese bromide, manganese perchlorate tetrahydrate, manganese sulfate monohydrate, manganese gluconate, and manganese glycinate. The manganese salts used advantageously are manganese glycinate and manganese acetate.

The salts of zinc, iron or copper include sulfates, gluconates, chlorides, lactates, acetates, glycinates, aspartates and citrates .

The additional metal oxide or oxides and/or salt or salts may be introduced in solid form into the compositions or else may come from a natural water, mineral or thermal, which is rich in these ions, or else from seawater (Dead Sea especially) . They may also originate from mineral compounds, for instance earths, ochres such as clays (green clay, for example) or even from a plant extract containing them (cf. for example, patent document FR 2 8 14 943) .

The additional metal oxides and/or salts o f the invention are preferably of oxidation state 2.

The particularly preferred metal salt or salts are chosen from zinc glycinate, manganese glycinate, manganese acetate, iron gluconate and mixtures thereof.

The additional, non-alum metal oxide or oxides and/or salt or salts may represent from 0.001 % to 10% by weight of the total weight of the composition or compositions containing this or these metal oxides and/or salts, and more preferably still from 0.05 %> to 5 % by weight.

The method according to the invention may be imp lemented in the presence o f a chemical oxidizing agent.

A chemical oxidizing agent denotes more particularly hydrogen peroxide, urea peroxide, alkali metal bromides and persalts such as perborates and persulfates .

The chemical oxidizing agent or agents may be present in the composition (C) or in a composition (d) which is applied after the composition (C) or after the composition (b), this composition (d) being separate from the composition (a) .

The compositions employed in the co louring method in accordance with the invention may also comprise various adjuvants conventionally used in compositions for dyeing hair, such as anionic, cationic, nonionic, amphoteric or zwitterionic surfactants or mixtures thereo f, anionic, cationic, nonionic, amphoteric or zwitterionic polymers or mixtures thereof, organic or inorganic thickeners, and more particularly anionic, cationic, nonionic and amphoteric polymeric associative thickeners, antioxidants, sequestrants, fragrances, buffers, dispersants, conditioning agents such as modified or non-modified, vo latile or non-vo latile silicones, film formers, ceramides, preservatives and opacifiers . The said adjuvants are preferably chosen from surfactants such as anionic and nonionic surfactants or mixtures thereof and from organic or inorganic thickeners .

The adjuvants above are generally present in an amount, for each of them, of between 0.01 % and 40% by weight, relative to the weight of the composition or compositions comprising them, preferably between 0. 1 % and 20% by weight, relative to the weight of the composition or compositions comprising them.

Needless to say, those skilled in the art will take care to select this or these optional additional compound(s) such that the advantageous properties intrinsically associated with the composition(s) that are of use in the dyeing process in accordance with the invention are not, or are not substantially, adversely affected by the envisaged addition(s).

The method according to the invention may employ one or more additional dyes, which may be present within the composition or compositions (a), (b) and/or (C) .

These dyes may more particularly be direct dyes, which are chosen, for example, from those conventionally used in direct dyeing, and which include all of the aromatic and/or non-aromatic dyes in current use, such as neutral, acidic or cationic nitrobenzene direct dyes, neutral, acidic or cationic azo direct dyes, neutral, acidic or cationic quinone, and more particularly anthraquinone, direct dyes, azine, triarylmethane and indoamine direct dyes, methines, styryls, porphyrins, metalloporphyrins, phthalocyanines, methine cyanines, fluorescent dyes, and natural dyes other than the chromans and chromenes.

The natural direct dyes include lawsone, juglone, indigo, isatin, curcumin, spinulosin, apigenidin and orceins . Use may also be made of extracts or decoctions comprising these natural dyes and in particular henna-based poultices or extracts.

The additional dye or dyes represent preferably from 0.001 % to

10% by weight, approximately, of the total weight of the composition or compositions employed.

When the chromene and/or chroman dye or dyes are present in an aqueous composition, the pH of this aqueous co louring composition varies advantageously from 2 to 12. This pH is preferably neutral, meaning that it varies from 6 to 8 , and more preferably from 6.5 to 7.5.

This pH may be adjusted to the desired value by means of acidifying or alkalifying agents which are commonly used in the dyeing of human keratin fibres, or else by means of conventional buffer systems.

The acidifying agents include, for example, inorganic or organic acids such as hydrochloric acid, orthophosphoric acid, sulfuric acid, carboxylic acids such as acetic acid, tartaric acid, citric acid and lactic acid, and sulfonic acids.

The alkalifying agent or agents may more particularly be chosen from aqueous ammonia, alkali metal carbonates, alkanolamines such as mono-, di- and triethanolamines and also derivatives thereof, sodium hydroxide or potassium hydroxide, and the compounds of the formula below :

in which W is a propylene residue optionally substituted by a hydroxyl group or a C ₁ -C₄ alkyl radical; R_a, R_b, R_c and R_d, which are identical or different, represent a hydrogen atom or a C ₁ -C₄ alkyl or C ₁ -C₄ hydroxyalkyl radical.

According to a first embodiment of the invention, the colouring method is carried out in one step, by application to the human keratin fibres of a dyeing composition (C) as described above.

The dyeing composition (C) may in particular be either in ready- to-use form or the result of extemporaneous mixing (that is, mixing just before application) of the compositions (a) and (b) as described above.

The leave-on time is generally set at between 3 and 120 minutes, preferably between 10 and 60 minutes and more preferably between 1 5 and 45 minutes.

According to a second embodiment of the invention, the co louring method is carried out in a plurality o f steps, by sequential application to the human keratin fibres of the composition (a) in a first stage, and then of the composition (b) in a second stage.

These steps may or may not be separated by interim rinsing. In the absence of such interim rinsing, wringing may be carried out, with a towel or with paper, so as to remove the excess composition.

The leave-on time after application o f the composition (a) or (C) varies generally from 3 to 120 minutes, preferably from 10 to 60 minutes, and more preferably from 15 to 45 minutes . The leave-on time after application o f the composition (b) varies generally from 3 to 120 minutes, preferably from 3 to 60 minutes, and more preferably from 5 to 30 minutes.

Irrespective o f the embodiment, the temperature at which compositions according to the invention are applied varies generally from room temperature ( 15 to 25 ° C) to 80° C and more particularly from 15 to 45 °C . Hence, fo llowing application o f the composition according to the invention, it is possible, advantageously, to subj ect the hair to thermal treatment by heating at a temperature of between 30 and 60°C . In practice, this operation may be conducted using a styling hood, a hairdryer, an infra-red radiation dispenser, and other conventional heating appliances.

It is also possible, both as heating means and as a means for smoothing the hair, to use heating tongs, at a temperature ranging from 60 to 220°C and preferably from 120 to 200°C .

The invention further pertains to a cosmetic dyeing composition comprising :

- one or more dyes chosen from chromene dyes and chroman dyes, as described above,

- one or more alums and/or the hydrates thereof as described above, and

- one or more liquid organic compounds having a Hansen so lubility parameter δΗ of less than or equal to 16 Mpa 1 /2

The above composition is particularly appropriate for the implementation o f the method of the invention as described above, and it may include any additional compounds, such as, among others, those described above.

The invention further pertains to the use of the composition according to the invention for co louring human keratin fibres, and more particularly the hair.

The present invention additionally provides a kit or device for the dyeing o f human keratin fibres, comprising at least two compartments :

a first compartment containing a dyeing composition (a) as described above, containing the dye or dyes chosen from chromene dyes and chroman dyes, and one or more liquid organic compounds having a

Hansen so lubility parameter δΗ of less than or equal to 16 Mpa 1 /2 ,

a second compartment containing a composition (b) as described above, comprising one or more alums and/or the hydrates thereo f.

According to one variant of the invention, the kit further comprises an additional composition comprising one or more oxidizing agents and/or an additional composition comprising one or more treatment agents . The compositions in the kit are packaged in separate compartments, which may optionally be accompanied by suitable, identical or different, application means, such as fine or coarse brushes or sponges .

The abovementioned kit may also be equipped with means allowing the delivery to the hair of the desired mixture, such as, for example, the device described in patent FR 2 586 913.

The evaluation of the co louration can be done visually or read on a spectrocolorimeter (such as Minolta CM3600d, illuminant D65 , angle 1 0° , SCI values) for the L* , a* , b * colorimetric measurements . In this L * , a* , b * system, L* represents the intensity of the co lour, a* indicates the green/red colour axis and b * indicates the blue/yellow co lour axis . The lower the value of L, the darker or more intense the colour. The higher the value o f a* , the redder the shade; the higher the value of b * , the yellower the shade . The variation in co louring between the co loured locks o f natural white hair (NW) which is untreated (control) and after treatment or colouration is defined by ΔΕ*, corresponding to the colour uptake on keratin fibres, according to the following equation:

(L -L₀ )²+(a -a₀ )²+(b -b₀ f

In this equation, L*, a* and b* represent the values measured after dyeing the natural hair comprising 90% of white hairs and Lo*, ao* and bo* represent the values measured for the untreated natural hair comprising 90% of white hairs.

The greater the value of ΔΕ, the greater the difference in colour between the control locks and the dyed locks and the greater colour uptake is.

On the other hand, for evaluating the selectivity of the colour between the root and tip of the keratin fibre, measurement can be done on permed or sensitized white hair (PW) and natural white hair, wherein the variation in colouring between the coloured locks PW and the coloured natural white hair as defined by ΔΕ*, corresponding to the selectivity of the colour, is calculated according to the following equation:

(L -L₀ )²+(a -a₀ )²+(b -b₀ f

In this equation, L*, a* and b* represent the values measured after dyeing the natural hair comprising 90% of white hairs and Lo*, ao* and bo* represent the values measured after dyeing the permed or sensitized hair. The lowest ΔΕ* is the best homogeneity of the hair colour.

If the light fastness is investigated, ΔΕ* is also calculated for the L₀*, a₀*, bo* and L*, a*, b* measured of the locks before and after exposure to the light, respectively.

Chromaticity in the CIE L*, a*, b* colourimetric system is calculated according to the following equation:

C* = Va*² + if² The greater the value of C * , the greater the chromaticity is.

The examples that fo llow serve to illustrate the invention without, however, being limiting in nature. EXAMPLE :

Compositions (a), (b l ) and (b2) below are prepared from the ingredients detailed hereinafter, the proportions of which are indicated in grams.

Pairs of lo cks of natural and permed Caucasian hair containing 90% white hairs are treated in succession with:

1 . the composition (a), which is left on for 45 minutes at 40°C, fo llowed by rinsing and wringing, and then

2. the composition (b l ) or the composition (b2), which is left on for 15 minutes at 40°C . Fo llowing the application of these treatments, the locks are rinsed, wrung and dried.

Locks with an intense iridescent brown co louration are obtained for the application o f the composition (a) and then o f the composition (b l ) .

Locks with an intense coppery mahogany co louration are obtained for the application o f the composition (a) and then of the composition (b2) .

In both cases, the locks are particularly glossy.

Very good results are also obtained by introducing the alums o f the compositions (b l ) and (b2) into the composition (a), which then becomes the composition (C), and by leaving this composition (C) on for 45 minutes at 40°C .

The hair then undergoes a test for tenacity after nine shampooings.

In both cases, the hair coloured using the method according to the invention is found to exhibit a high level of shampoo tenacity, retaining a high level o f intensity and shine.

Claims

1 . Method for colouring human keratin fibres, and more particularly the hair, comprising the application to the said fibres of:

(b) a composition comprising one or more alums and/or the hydrates thereof;

2. Method according to Claim 1 , wherein the dye or dyes chosen from the chromene dyes and the chroman dyes are chosen from the compounds o f formulae below:

(i) the compounds of formula (I) :

in which:

- X represents a group : // /

HO— C _or 0=C

\ \

the compounds of formula (II)

in which:

-Rii, Ri2, Ri3, Ri6, Ri and R₂o, which are identical or different, represent, independently of one another, a hydrogen atom or a C1-C4 alkyl radical,

-Ri4, Ri5, Ri7 and Ris, which are identical or different, represent, independently of one another, a hydrogen atom, a hydroxyl radical or a C1-C4 alkoxy radical,

3. Method according to either of the preceding claims, wherein the dye or dyes chosen from the chromene dyes and the chroman dyes are chosen from haematein, haematoxylin, brazileine, brazilin, santalin A and mixtures thereo f, and more preferably from haematein, haematoxylin, brazileine, brazilin and mixtures thereof, and more preferably still from haematoxylin and brazilin or mixtures thereof.

4. Method according to any one o f the preceding claims, wherein the dye or dyes chosen from the chromene dyes and chroman dyes represent from 0.00 1 % to 20% by weight, relative to the total weight of the dyeing composition (a) or (C), preferably from 0.01 % to 10%> by weight, and more preferably still from 0. 1 % to 5 % by weight.

5. Method according to any one o f the preceding claims, wherein the alum or alums conform to the formula:

MA1(S0₄)₂

in which M denotes a monovalent cation chosen from potassium, sodium and ammonium ions .

6. Method according to any one o f the preceding claims, wherein the alum or alums and/or the hydrates thereof represent from 0. 1 % to

20%) by weight, relative to the total weight of the composition (b) or (C), preferably from 0.5 % to 10% by weight, and more preferably still from 1 % to 5 % by weight.

7. Method according to any one o f the preceding claims, wherein the composition or compositions (a), (b) and/or (C) comprise water.

8. Method according to any one o f the preceding claims, wherein the dyeing composition (a) and/or (C) comprises one or more liquid organic compounds having a Hansen so lubility parameter δΗ of strictly

1 /2

less than 16 Mpa , preferably chosen from benzyl alcohol, phenylpropanol, phenylethanol, phenoxyethanol, linear alcohols containing from 5 to 12 carbon atoms, and mixtures thereo f.

9. Method according to any one o f the preceding claims, wherein the said liquid organic compound or compounds are present in proportions ranging from 1 % to 40% by weight, relative to the total weight of the dyeing composition (a) and/or (C), and more preferably from 2% to 20% by weight.

10. Method according to any one o f the preceding claims, wherein the composition or compositions (a), (b) and/or (C) comprise one or more additional, non-alum metal salts and/or metal oxides, chosen preferably from the salts and/or oxides of zinc, manganese, iron and copper, and more preferably from zinc glycinate, manganese glycinate, manganese acetate, iron gluconate and mixtures thereof.

1 1 . Method according to any one o f the preceding claims, employing one or more chemical oxidizing agents .

12. Method according to the preceding claim, wherein the chemical oxidizing agent or agents are present in the composition (C) or in a composition (d) which is applied after the composition (C) or after the composition (b), this composition (d) being separate from the composition (a) .

13 . Cosmetic dyeing composition comprising :

- one or more dyes chosen from chromene dyes and chroman dyes,

- one or more alums and/or the hydrates thereo f, and

one or more liquid organic compounds having a Hansen so lubility parameter δΗ of less than or equal to 16 Mpa 1 /2

14. Kit for dyeing human keratin fibres, comprising at least two compartments :

a first compartment containing a dyeing composition (a) as defined in any one o f Claims 1 to 10, comprising one or more dyes chosen from chromene dyes and chroman dyes, and one or more liquid organic compounds having a Hansen so lubility parameter δΗ of less than or equal to 16 Mpa 1 /2 , and

- a second compartment containing a composition (b) as defined in any one o f Claims 1 to 10, comprising one or more alums and/or the hydrates thereof.