WO2013125053A1 - Process for treating keratin fibers - Google Patents

Abstract

The present invention relates to a process for treating keratin fibers, in particular hair, comprising the steps of: applying onto the keratin fibers a composition comprising at least 0.1 % by weight, relative to the total weight of the composition, of one or more natural dyes; placing the keratin fibers in an occlusive space; and heating the keratin fibers to from 50 to 250 °C. The present invention can provide a new coloring process for keratin fibers, such as hair, based on natural coloring(s) which can provide the keratin fibers with intense color with good level of color coverage, resistance to external factors or agents such as a shampoo, and only little damage.

Description

DESCRIPTION

PROCESS FOR TREATING KERATIN FIBERS TECHNICAL FIELD

The present invention relates to a process for treating keratin fibers such as hair.

BACKGROUND ART

It is known to dye keratin fibers and in particular human hair with dyeing compositions containing oxidative coloring precursors, generally called oxidative bases, such as ortho- or

para-phenylenediamines, ortho- or para-aminophenols and heterocyclic compounds. These oxidative bases are generally combined with couplers. These bases and these couplers are colorless or weakly colored compounds which, combined with oxidizing products, can give rise to colored compounds through an oxidative condensation process.

This type of coloring by oxidation makes it possible to get colors with very high visibility, coverage of white hair and in a wide variety of shades but it results in damage to the keratin fibers by the use of oxidizing agents (in particular by repeated application or by combination with other hair treatments).

It is also known to dye keratin fibers and in particular human hair with dyeing compositions containing direct dyes. Conventional direct dyes are in particular the following: benzene nitrates, anthraquinones, nitropyridines, azos, xanthines, acridinies, azinies, and triarylmethane type or natural colorings.

These dyes can be non-ionic, anionic, cationic or amphoteric. These direct dyes are colored or coloring molecules with an affinity for keratin fibers.

Most of the direct dyes used have sufficient solubility in aqueous medium and there are now many coloring supports or medium suited for receiving the direct dyes.

A composition or compositions containing one or more direct dyes can be applied on keratin fibers for a time needed to obtain the desired shade, and then can be rinsed.

The resulting colors are particularly chromatic but remain temporary or semipermanent because of the nature of the interactions which bind the direct dyes to the keratin fiber, and their desorption from the surface and/or core of the fiber is responsible for their weak dyeing power and their poor fastness with washings.

Today, hair dyeing methods using natural products are thought of more and more desired by users. Using natural dyes for hair dyeing is already known in the art but the effectiveness of the method described still needs to be improved. There are therefore real needs to develop hair dyeing methods, using composition(s) containing natural dye(s), leading to intense color, allowing good level of color coverage of keratin fibers particularly Asian (Chinese, Japanese, and the like) hair, i.e., low selectivity, and resistance to external factors or agents (light, weather, shampooing), and respecting the nature of the hair.

DISCLOSURE OF INVENTION

Thus, an objective of the present invention is to provide a dyeing process which is based on natural dye(s) having both good level of color coverage of keratin fibers - but also offering intense coloring - and resistance to external factors or agents, and which can give only little damage to the keratin fibers.

The above objective of the present invention can be achieved by a process for treating keratin fibers, in particular hair, comprising the steps of:

applying onto the keratin fibers a composition comprising at least 0.1 % by weight, relative to the total weight of the composition, of one or more natural dyes;

placing the keratin fibers in an occlusive space; and

heating the keratin fibers to from 50 to 250 °C. The process may further comprise the step of rinsing the keratin fibers after the step of applying the composition onto the keratin fibers and/or after the step of heating the keratin fibers.

The process may further comprise providing the keratin fibers with mechanical tension. The occlusive space may be formed by at least one coating means. The coating means may be rigid or flexible. The coating means may comprise at least one member selected from the group consisting of a film and a sheet.

According to the present invention, the keratin fibers may be heated at 60 °C to 150 °C during the step of heating the keratin fibers. The keratin fibers may be heated by at least one heater providing at least one selected from the group consisting of hot air, hot steam, high frequency induction heating, microwave heating, infrared ray irradiation, laser, and flash lamp irradiation. The above coating means may comprise the heater. The direct dye may be chosen among curcuminoids, santalins, chlorophyllin, haematoxylin, haematein, brazilein, brazilin, sorghum, laccaic acid, lawsone, juglone, alizarin, purpurin, carminic acid, kermesic acid, purpurogallin, protocatechaldehyde, indigoids, isatin, spinulosin, apigenidin, orcein, betanin, flavonoids, anthocyans, and extracts or decoctions containing these compounds. The composition may comprise the natural dye(s) in an amount of 0.1 to 30% by weight, relative to the total weight of the composition.

It is preferable that the composition comprise at least one organic compound which is liquid at 25 °C and atmospheric pressure (760 mmHg) with a value, δΗ, of Hansen solubility parameter of less than 16 MPa at 25 °C. Thisorganic compound may be chosen among C₅-C₃₀ alkanols; alcohol ethers, particularly Q-C₄ ether of Cs-C₃₀ alcohols, preferably saturated, optionally interrupted by one or more non vicinal ether groups; aliphatic esters of C1-C4 carboxylic acids and C₃-C₁₀ monoalcohols or C₃-C₁₀ polyols, optionally interrupted by one or more non vicinal ether groups; aromatic ethers, particularly C₆-C₁₀, of Q-C6 alkyl, optionally bearing a hydroxyl group; alkanol with aryl or oxyaryl substituting group, particularly wherein the aryl part is a C₆-C₁₀ aryl, preferably C₆, and the alkanol is a Q-C₄ alkyl; lactones particularly of formula (I)

wherein R' represents a hydrogen, a (Q-Q) alkyl group, a (C1-C4) hydroxyalkyl group, n meansl, 2 or 3; alkylene carbonate of formula (II) :

wherein R" represents a hydrogen atom, a (Ci-C₈) alkyl group, a (C1-C4) hydroxyalkyl group.

It is preferable that the process according to the present invention further comprise the step of treating the keratin fibers with a composition comprising at least one organic or inorganic salt of a metal chosen among iron, copper, zinc, tin, aluminum, manganese, silver, preferably, zinc, and manganese. The organic or inorganic salt of a metal may be chosen among zinc or manganese chloride, sulfate, gluconate, and glycinate.

Another aspect of the present invention is use of a composition for treating keratin fibers at a temperature from 50 to 250 °C in an occlusive space, comprising at least one natural direct dye as mentioned above, in an amount of 0.1 % by weight or more relative to the total weight of the composition.

The present invention also relates to a kit for treating keratin fibers, comprising:

a device comprising

at least one coating means to form an occlusive space, and

at least one heater to heat the keratin fibers to from 50 to 250 °C in the occlusive space;

and

a composition comprising at least one or more natural dyes as previously defined, in an amount of 0.1 % by weight or more relative to the total weight of the composition.

BEST MODE FOR CARRYING OUT THE INVENTION

After diligent research, the inventors have discovered that it is possible to achieve a dyeing process for keratin fibers, such as hair, based on natural dye(s) which can provide the keratin fibers with intense color with good level of color coverage, resistance to external factors or agents such as a shampoo, and only little damage.

According to the present invention, the above dyeing process involves in heating keratin fibers in a closed or occlusive environment, which limits the evaporation of water or moisture from the keratin fibers and maintains the keratin fibers at a higher temperature in the wet state.

Thus, the present invention is a process for treating keratin fibers comprising the steps of:

applying onto the keratin fibers a composition comprising at least one natural direct dye in an amount of 0.1 % by weight or more, relative to the total weight of the composition;

placing the keratin fibers in an occlusive space; and

heating the keratin fibers to from 50 to 250 °C. Accordingly, the present invention can provide keratin fibers with intense color, low selectivity (good level of color coverage along with the keratin fibers from the root to tip), resistance to external factors or agents such as a shampoo, and only little damage.

(Composition)

The composition used for the present invention contains at least one natural direct dye. Two or more types of the natural dye may be used in combination.

The expression "natural dye" is understood to mean any dye or dye precursor that is naturally occurring and is produced either by extraction (and optionally purification) from a plant matrix optionally in the presence of natural compounds such as ash or ammonia, or by chemical synthesis.

As natural dye, mention may be made of quinone dyes (such as lawsone and juglone), alizarin, purpurin, laccaic acid, carrninic acid, kermesic acid, purpurogallin, protocatechaldehyde, indigoids such as indigo, sorghum, isatin, betanin, curcurninoids (such as curcurnin), spinulosin, various types of chlorophyll and chlorophyllin, hematoxylin, hematein, brazilein, brazilin, safflower dyes (such as carmamin), flavonoids (such as rutin_s quercetin, catechin, epicatechin, morin, apigenidin, and sandalwood), anthocyans (such as apigeninidin and apigenidin), carotenoids, tminins, orceins, santalins and cochineal carmine.

It is also possible to use extracts or decoctions containing natural direct dye(s), in particular henna-based extracts, curcuma longa extract, sorghum leaf-sheath extract, haematoxylon campechianum extract, green tea extract, pine bark extract, cocoa extract, and logwood extract.

It is preferable that the natural dye be chosen from the group consisting of curcurninoids, santalins, chlorophyllin, haematoxylin, haematein, brazilein, brazilin, sorghum, laccaic acid, lawsone, juglone, alizarin, purpurin, carrninic acid, kermesic acid, purpurogallin, protocatechaldehyde, indigoids, isatin, spinulosin, apigenidin, orcein, betanin, flavonoids, anthocyans, and extracts or decoctions containing these compounds.

Alternatively, the natural dyes may be preferably chosen, for example, from hydroxylated quinones, indigoids, hydroxyflavones, santalins A and B, isatin and its derivatives, and brasilin and its hydroxylated derivative. The hydroxylated quinones are preferably benzoquinones, naphthoquinones, and mono- or polyhydroxylated anthraquinones which are optionally substituted with groups such as alkyl, alkoxy, alkenyl, chloro, phenyl, hydroxyalkyl and carboxyl. The naphthoquinones are preferably lawsone, juglone, flaviolin, naphthazarin, naphmopurpurin, lapachol, plumbagin, chloroplumbagin, droserone, shikonin,

2-hydroxy-3 -methyl- 1 ,4-naphthoquinone, 3 ,5-dihydroxy- 1 ,4-naphthoquinone,

2,5-dihydroxy- 1 ,4-naphthoquinone, 2-methoxy-5-hydroxy- 1 ,4-naphthoquinone and

3 -methoxy-5 -hydroxy- 1 ,4-naphthoquinone.

The benzoquinones are preferably spinulosin, atromentin, aurentioglyocladin,

2,5-dihydroxy-6-methylbenzoquinone, 2-hydroxy-3-methyl-6-methoxybenzoquinone, 2, 5-dihydroxy-3 ,6-diphenylbenzoquinone, 2,3 -dimethyl-5 -hydroxy-6-methoxybenzoquinone and 2,5-dihydroxy-6-isopropylbenzoquinone.

The anthraquinones are preferably alizarin, quinizarin, purpurin, carrninic acid, chrysophanol, kermesic acid, rhein, aloe emodin, ρεε^ο υ υήη, quinizarincarboxylic acid, frangula emodin, 2-memylquinizarin, 1-hydroxyanthraquinone and 2-hydroxyanthraquinone. The indigoids are preferably indigo, indirubin, isoindigo and Tyrian purple.

The hydroxyflavones are preferably quercetin and morin.

The composition used for the present invention contains the natural direct dye(s) in an amount of 0.1% by weight or more, and may contain, for example, 0.1 to 30% by weight, preferably 0.5 to 20% by weight, and more preferably 2 to 10% by weight, relative to the total weight of the composition.

The composition used for the present invention may also contain one or more additional dyes, such as oxidative dyes: one or more oxidation bases and/or one or more couplers. By way of example, the oxidation bases are chosen from para-phenylenediamines,

bis-phenylalkylenediamines, para-aminophenols, or&o-aminophenols, heterocyclic bases and addition salts thereof. The oxidation base(s) may be present in an amount ranging from around 0.001 to 30% by weight, preferably ranging from 0.001 to 20% by weight, and more preferably 0.1 to 10% by weight, relative to the total weight of the composition.

The composition used for the present invention may contain at least one coupler conventionally used for dyeing keratin fibers. Among these couplers, mention may especially be made of meta-phenylenediamines, meta-aminophenols, meta-diphenols, naphthalene couplers, heterocyclic couplers and also addition salts thereof.

The coupler(s) may be present in an amount ranging from around 0.001 to 30% by weight, preferably ranging from 0.001 to 20% by weight, and more preferably 0.1 to 10%) by weight, relative to the total weight of the composition.

Generally, addition salt(s) of the oxidation base(s) and/or of the coupler(s) may be in particular chosen from addition salts with acid such as hydrochlorides, hydrobromides, sulfates, citrates, . succinates, tartrates, lactates, tosylates, benzenesulfonates, phosphates and acetates, and addition salts with base such as sodium hydroxide, potassium hydroxide, ammonium hydroxide, amines and alkanolamines.

The compositions used for the present invention may also contain at least one additional direct dye chosen among the synthetic direct dyes (i.e.: non natural direct dyes).

Non-limiting examples of such synthetic direct dyes include neutral, anionic(acidic), and cationic dyes azo, methine, carbonyl, azine, nitro(hetero)aryl types or tri(hetero)arylmethane direct dyes, porphyrins and phthalocyanines, fluorescent dyes, alone or as mixtures.

More particularly, the azo dyes comprise an -N=N- functional group, the two nitrogen atoms of which are not simultaneously involved in a ring. However, it is not ruled out for one of the two nitrogen atoms of the -N=N- sequence to be involved in a ring. The dyes of the family of the metnines are more particularly compounds comprising at least one sequence chosen from >C=C< and -N=C<, the two atoms of which are not simultaneously involved in a ring. However, it is specified that one of the nitrogen or carbon atoms of the sequences can be involved in a ring. More particularly, the dyes of this family result from compounds of the following types: true methine (comprising one or more abovementioned -C=C- sequences); azomethine (comprising at least one or more -C=N- sequences) with, for example, the azacarbocyanines and their isomers, the diazacarbocyanines and their isomers, the tetraaza- carbocyanines; mono- and diarylmethane; mdoamines (or diphenylamines); indophenols;

indoanilines. As regards the dyes of the family of the carbonyls, mention may be made, for example, of nonnatural dyes chosen from acridone, benzoquinone, anthraquinone, naphthoquinone, benzanthrone, anthranthrone, pyranthrone, pyrazolanthrone, pyriniidinoanthrone, flavanthrone, indanthrone, fiavone, (iso)violanthrone, isoindolinone, benzimidazolone, isoquinolinone, anthrapyridone, pyrazoloquinazolone, perinone, quinacridone, quinophthalone, naphthalimide, anthrapyrimidine, diketopyrrolopyrrole or coumarin dyes.

As regards the dyes of the family of the cyclic azines, mention may in particular be made of azine, xanthene, thioxanthene, fluorindine, acridine, (di)oxazine, (di)thiazine or pyronine dyes. The nitro(hetero)aromatic dyes are more particularly nitrobenzene or nitropyridine direct dyes.

As regards the dyes of porphyrin or phmalocyanine type, use may be made of cationic or noncationic compounds optionally comprising one or more metals or metal ions, such as, for example, alkali and alkaline earth metals, zinc and silicon. As used herein, the term "fluorescent dyes" is understood to mean fluorescent compounds and optical brighteners. In at least one embodiment, the fluorescent dye is soluble in the medium of the composition. Fluorescent dyes are fluorescent compounds which absorb visible radiation, for example, wavelengths ranging from 400 to 800 nm, and which are capable of re-emitting light in the visible region at a higher wavelength. According to one embodiment, the fluorescent dyes useful for the present invention re-emit orange-colored fluorescent light. They exhibit, for instance, a maximum re-emission wavelength ranging from 500 to 700 nm.

Non-limiting examples of fluorescent dyes include compounds known in the art, for example, those described in Ullmann's Encyclopedia of Industrial Chemistry, Release 2004, 7th edition, "Fluorescent Dyes" chapter.

The optical brighteners, are colorless transparent compounds as they do not absorb in visible light but only in ultraviolet light (wavelengths ranging from 200 to 400 nanometers) and convert the energy absorbed into fluorescent light of higher wavelength emitted in the visible part of the spectrum, generally in the blue and/or green, that is to say in wavelengths ranging from 400 to 550 nanometers. Optical brighteners are known in the art, for example, they are described in Ullmann's

Encyclopedia of Industrial Chemistry (2002), "Optical Brighteners" and Kirk-Othmer

Encyclopedia of Chemical Technology (1995): "Fluorescent Whitening Agents".

The fluorescent dyes which can be used in the composition of the present disclosure include compounds known from the art, for example, those described in French Patent No. 2 830 189.

Mention may be made, as examples of synthetic direct dyes which are particularly suitable, of nitrobenzene dyes, azo, azomethine or methine direct dyes, azacarbocyanines, such as

tetraazacarbocyanines (tetraazapentamethines), quinone and in particular anthraquinone, naphthoquinone or benzoquinone direct dyes, or azine, xanthene, triarylmethane, indoamine, phthalocyanine and porphyrin direct dyes, alone or as mixtures. More preferably still, these additional synthetic direct dyes are chosen from nitrobenzene dyes, azo, azomethine or methine direct dyes and tetraazacarbocyanines (tetraazapentamethines); alone or as mixtures.

The composition used for the present invention may contain the synthetic direct dye(s) in an amount of 0.1 to 30% by weight, preferably 1 to 20% by weight, and more preferably 2 to 10% by weight, relative to the total weight of the composition.

According to one particular embodiment, the composition used for the present invention may contain, as dyes, only natural direct dye(s).

It is preferable that the composition used for the present invention contain at least one organic compound which is liquid at 25 °C and atmospheric pressure (760 mmHg) with a value of Hansen solubility parameter (δΗ) of less than 16 MPa^1/2 at 25 °C. Two or more types of the organic compound may be used in combination. The organic compound is preferably capable of fLmctioning as an organic solvent. According to one particular embodiment, the δΗ value is preferably less than 15 MPa at 25 °C, more preferably less than 14.5 MPa^{1 2} at 25 °C, and further more preferably less than 14 MPa^{1 2} at 25 °C. According to one particularly preferred embodiment, the δΗ value is greater than 0.

According to one variant, the δΗ value may be greater than 3 MPa^{1 2} at 25 °C, preferably greater than 4 MPa¹² at 25 °C, and more preferably greater than 5 MPa^1/2 at 25 °C.

The organic compounds, such as organic solvents, having a value of the Hansen solubility parameter δΗ as defined previously are, for example, described in the reference work "Hansen solubility parameters- A user's handbook", Charles M. Hansen, CRC Press, 2000, pages 167 to 185.

This value takes into account the solubility parameter δΗ linked to the formation of hydrogen bonds. It is recalled that there are three main types of interactions in organic compounds, non-polar interactions, permanent dipole-dipole interactions and hydrogen bonding type interactions, the latter being the subject of the parameter that defines the organic compound preferably used in the present invention.

It is preferable that the organic compound be selected from the group consisting of C₅-C₃₀ alkanols; alcohol ethers, particularly Q-C₄ ether of C₅-C₃₀ alcohols, preferably saturated, optionally interrupted by one or more non vicinal ether groups; aliphatic esters of C1-C4

carboxylic acids and C₃-C₁₀ monoalcohols or C₃-C₁₀ polyols, optionally interrupted by one or more non vicinal ether groups; aromatic ethers, particularly C₆-C₁₀, of Ci-Ce alkyl, optionally bearing a hydroxyl group; alkanol with aryl or oxyaryl substituting group, particularly wherein the aryl part is a Ce-Cio aryl, preferably C₆, and the alkanol is a C C₄ alkyl; lactones particularly of formula (I):

wherein R' represents a hydrogen, a (Ci-C₈) alkyl group, a (C1-C4) hydroxyalkyl group, n means 1, 2 or 3; alkylene carbonate of formula (II) :

wherein R" represents a hydrogen atom, a (Q-Cs) alkyl group, a (Ci-C₄) hydroxyalkyl group.

As the alkylene carbonate, mention may be made of ethylene carbonate (R"=H), propylene carbonate (R"=CH₃), glycerol carbonate (R"=CH₂OH), or else butylene carbonate (R"=CH₂CH₃). Among the alkylene carbonates, propylene carbonate is preferred. It is also preferable that the organic compound be selected from propyleneglycol derivatives, aromatic alcohols and alkylene carbonates. As the propyleneglycol derivatives, mention may be made of propyleneglycol ethers having at least one free alcohol functional moiety, or propyleneglycol esters having at least one ether moiety.

The term "aromatic alcohol" means an alcohol having at least one hydroxyl group which does not directly bond to an aromatic moiety such as a benzene ring. As the aromatic alcohols, mention may be made of benzyl alcohol, phenyl ethanol, and phenyl propanol.

In particular, as the organic compound, mention may be made of the compounds in the following table.

The composition used for the present invention may contain the organic compound(s) which is/are liquid at 25 °C and atmospheric pressure (760 mmHg) with a value of Hansen solubility parameter (δΗ) of less than 16 MPa^{1 2} at 25 °C in an amount of 0.1 to 80% by weight, preferably 1 to 50% by weight, and more preferably 2 to 30% by weight, relative to the total weight of the composition.

The composition used for the present invention may contain at least one organic or inorganic salt of a metal chosen among iron, copper, zinc, tin, aluminum, manganese, silver, preferably, zinc, and manganese. Two or more types of the organic or inorganic salt of a metal may be used in combination. It may be preferable that the organic or inorganic salt of a metal be chosen among zinc or manganese chloride, sulfate, gluconate, and glycinate. Zinc glycinate may be the most preferable. The organic or inorganic salt of the above metal may function as a complexing agent or a sequestering agent. If the organic or inorganic salt of the above metal is used, the cosmetic properties, such as the color fastness, of the dyed keratin fibers may be more enhanced.

The amount of the organic or inorganic salt(s) of the above metal in the composition used for the present invention may be 0.01 to 20% by weight, preferably 0.1 to 10% by weight, and more preferably 1 to 5% by weight, relative to the total weight of the composition. The composition used for the present invention may contain water. Preferably, the amount of water in the composition used for the present invention may be at least equal to 40% by weight relative to the total weight of the composition. More preferably, the amount of water may be at least equal to 70% relative to the total weight of the composition.

The composition used for the present invention may contain at least one additional organic solvent different from the compound with the Hansen solubility parameter (5H) as previously defined. By way of example, mention may be made of C1-C4 lower alkanols, such as ethanol and isopropanol; polyols such as propylene glycol or glycerol and mixtures thereof.

The amount of the above additional organic solvent(s) in the composition used for the present invention may vary between around 0.1 and 80% by weight, preferably between around 0.5 and 50% by weight, and more preferably between 1 and 30% by weight, relative to the total weight of the composition.

When the composition contains at least one oxidative dye or when it is desired to use a lightening dye, an oxidizing agent may be used.

The oxidizing agents conventionally used for oxidation dyeing of keratinous fibers are, for example, hydrogen peroxide, urea peroxide, alkali metal bromates, persalts such as perborates and persulfates, peracids and oxidase enzymes, among which mention may be made of peroxidases, 2-electron oxidoreductases such as uncases and 4-electron oxygenases such as laccases.

Hydrogen peroxide is particularly preferred. This oxidizing agent may also be present in the composition used for the present invention or may be applied to keratin fibers independently as the form of an oxidizing composition.

The compositions used for the present invention may also contain various adjuvants

conventionally used in compositions for dyeing hair, such as anionic, non-ionic, cationic, amphoteric or zwitterionic polymers, or mixtures thereof, antioxidants, penetrating agents, sequestering agents, fragrances, buffers, dispersing agents, conditioning agents, film-forming agents, ceramides, preservatives and opacifying agents.

By way of conditioning agent, mention may be made of branched or unbranched, volatile or non- volatile linear or cyclic silicones. These silicones may be in the form of oils, resins or gums, they may in particular be polyorganosiloxanes that are insoluble in the cosmetically acceptable medium.

Organopolysiloxanes are defined in greater detail in the work by Walter Noll, "Chemistry and Technology of Silicones" (1968) Academic Press. They may be volatile or non-volatile.

When they are volatile, the silicones are more particularly chosen from those having a boiling point between 60 °C and 260 °C. By way of conditioning agent, use can also be made of polymers such as the polyquaterniums 22, 6, 10, 11, 35 and 37 and hexadimethrine chloride.

The concentration of conditioning agent(s) in the composition used for the present invention may vary from 0.01 to 10% by weight, preferably from 0.05 to 5% by weight, and more preferably from 0.1 to 3% by weight, relative to the total weight of the composition.

The compositions used for the present invention may contain, in addition, at least one thickening agent also known as "rheology modifiers". This agent may be mineral or organic. The organic thickening agents may be chosen from fatty acid amides (coconut diethanolamide or monoethanol-amide, oxyethylenated alkyl ether carboxylic acid monoethanolamide), polymeric thickeners such as cellulose thickeners (hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose), guar gum and its derivatives (hydroxypropyl guar), gums of microbial origin (xanthan gum, scleroglucan gum), homopolymers crosslinked with acrylic acid or acrylamidopropanesulfomc acid and neutral, anionic, amphoteric or cationic associative polymers (polymers comprising hydrophilic zones, and hydrophobic zones having a fatty chain, that are capable, in an aqueous medium, of reversibly associating with one another or with other molecules). According to one particular embodiment, the thickener is polymeric and is chosen from cellulose thickeners (hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose), guar gum and its derivatives (hydroxypropyl guar), gums of microbial origin (xanthan gum, scleroglucan gum), homopolymers crosslinked with acrylic acid or acrylamidopropanesulfonic acid. The composition used for the present invention may furthermore contain at least one surfactant.

The surfactant(s) may be selected from the following (i) to (iv).

(i) Anionic Surfactant(s)

An "anionic surfactant" is understood to mean a surfactant only comprising anionic groups as ionic or ionizable groups. These groups are preferably chosen among the -C(0)OH, -C(0)0^", -S0₃H,

-OS(0)20H, -OS(0)₂Cr, -P(0)OH₂, -Ρ(0)2θ-, -Ρ(0)0₂-, -P(OH)₂, =P(0)OH, -P(OH)0; =P(0)0^", =POH, =PO^" groups, where the anionic parts comprise a cationic counter-ion such as an alkaline metal, an alkaline-earth metal or ammonium.

The following can be listed as anionic surfactants which can be used in the composition according to the invention: alkyl sulfates, alkyl ether sulfates, alkylamidoether sulfates, alkylarylpolyether sulfates, monoglyceride sulfates, alkyl sulfonates, alkyl amide sulfonates, alkyl aryl sulfonates, alpha-olefin sulfonates, paraffin sulfonates, alkyl sulfosuccinates, alkyl ether sulfosuccinates, alkyl amide sulfosuccinates, alkyl sulfoacetates, acylsarcosinate, acylglutamates, alkyl sulfosuccinamates, acylisethionates, N-acyltaurates, alkyl and polyglycoside polycarboxylic acid monoester salts, acyllactylates, D-galactoside uronic acid salts, alkyl ether carboxylic acid salts, alkylaryl ether carboxylic acid salts, alkylarnido ether carboxylic acid salts, and the corresponding unsalted forms of all these compounds, where the alkyl and acyl groups of all these compounds comprise from 6 to 40 carbon atoms and the aryl group designates a phenyl group.

These compounds can be oxyethylenated and then comprise preferably from 1 to 50 ethylene oxide units.

The salts of C₆-C₂₄ alkyl and polyglycoside-polycarboxylic acid monoesters can be chosen among the C₆-C₂₄ alkyl polyglycoside citrates, C₆-C₂₄ alkyl polyglycoside tartrates and the C₆-C₂₄ alkyl polyglycoside sulfosuccinates. When the anionic surfactant(s) is/are in salt form, they can be chosen from alkaline metal salts such as sodium or potassium salts and preferably sodium, ammonium salts, amine salts and in particular amino alcohols, or alkaline-earth metal salts such as magnesium salts.

The following can be cited in particular as examples of amino alcohol salts: mono-, di- and tri-ethanolamine salts, mono-, di- or tri-isopropanolarnine salts, and the salts of

2-amino-2-methyl-l-propanol, 2-arnino-2-methyl-l,3-propanediol and tris(¾ydroxy-methyl)amino methane.

Preferably the alkaline or alkaline earth metal salts and in particular the sodium or magnesium salts are used.

Among the cited anionic surfactants, the use of (C₆-C₂₄)alkyl sulfates, (C₆-C₂₄)alkyl ether sulfates comprising from 2 to 50 ethylene oxide units, especially in the form of alkaline metal, ammonium, amino alcohol and alkaline-earth metal salts, or a mixture of these compounds, is preferred.

In particular, the use of (C₁₂-C₂o)alkyl sulfates, (C₁₂-C₂₀)alkylether sulfates comprising from 2 to 20 ethylene oxide units, especially in the form of alkaline metal, ammonium, amino alcohol and alkaline-earth metal salts, or a mixture of these compounds, is preferred. Better still, the use of sodium lauryl ether sulfate with 2.2 mol of ethylene oxide is preferred.

(ii) Non-Ionic Surfactant(s)

The non-ionic surfactants are themselves also compounds which are well known per se (in this respect see, in particular, "Handbook of Surfactants" by M. R. Porter, published by Blackie & Son (Glasgow and London), 1991, pp. 116-178). Thus, they may especially be chosen from

(non-limiting list) alcohols, a-diols or alkylphenols that are polyethoxylated or polypropoxylated, having a fatty chain comprising, for example 8 to 18 carbon atoms, the number of ethylene oxide or propylene oxide groups possibly ranging, in particular, from 2 to 50. Mention may also be made of the copolymers of ethylene and propylene oxide, the condensates of ethylene and propylene oxide with fatty alcohols; polyethoxylated fatty amides preferably having from 2 to 30 mol of ethylene oxide, polyglycerolated fatty amides comprising, on average, 1 to 5, and in particular 1.5 to 4, glycerol groups; oxyethylenated esters of sorbitan fatty acids having from 2 to 30 mol of ethylene oxide; sucrose fatty acid esters, polyethylene glycol fatty acid esters, alkyl polyglycosides, N-alkylglucamine derivatives, amine oxides such as oxides of (C₁₀-C₁₄) alkylamines or oxides of N-acylamino-propylmorpholine. (iii) Amphoteric or Zwitterionic Surfactant(s)

The amphoteric or zwitterionic surfactants may especially be (non-limiting list) derivatives of aliphatic secondary or tertiary amines in which the aliphatic radical is a linear or branched chain comprising 8 to 18 carbon atoms and containing at least one water-solubilizing anionic group (for example carboxylate, sulfonate, sulfate, phosphate or phosphonate); mention may also be made of (C8-C₂₀)alkyl betaines, sulfobetaines, (C₈-C2o)alkylamido-(C₁-C₆) alkyl betaines or

(C₈-C₂o)aIkylamido(C₁-C₆)alkyl sulfobetaines.

Among the amine derivatives, mention may be made of the products sold under the name MRANOL, as described in U.S. Pat. Nos. 2,528,378 and 2,781,354 and classified in the CTFA dictionary, 3rd edition, 1982, under the names Amphocarboxyglycinates and

Amphocarboxypropionates.

These compounds are classified in the CTFA dictionary, 5th edition, 1993, under the names Disodium Cocoamphodiacetate, Disodium Lauroamphodiacetate, Disodium

Caprylamphodiacetate, Disodium Capryloamphodiacetate, Disodium Cocoamphodipropionate, Disodium Lauroamphodipropionate, Disodium Capryl-amphodipropionate, Disodium

Capryloamphodipropionate, Lauroamphodipropionic acid, Cocoamphodipropionic acid.

By way of example, mention may be made of the cocoamphodiacetate sold under the trade name MIRANOL® C2M concentrate by Rhodia Chimie. (iv) Cationic Surfactants

Among the cationic surfactants, mention may, in particular, be made (non-limiting list) of: salts of primary, secondary or tertiary fatty amines, optionally polyoxyalkylenated; quaternary ammonium salts such as tetraalkylammonium, alkylamidoalkylrrialkylarnmonium, trialkylbenzylammonium, trialkylhydroxyalkylarnmonium or alkylpyridinium chlorides or bromides; imidazoline derivatives; or oxides of amines having a cationic nature.

The amount of surfactant(s) present in the composition used for the process of the present invention may vary from 0.01 to 40% by weight, preferably from 0.5 to 30% by weight, relative to the total weight of the composition.

The pH of the composition applied to the keratin fibers is generally between 2 and 13, preferably between 3 and 10, and preferably from 7 to 10. It may be adjusted to the desired value using acidifying or basifying agents commonly used in dyeing keratinous fibers or else using conventional buffer systems.

Among the acidifying agents, mention may be made, by way of example, of mineral or organic acids such as hydrochloric acid, ortho-phosphoric acid, sulfuric acid, carboxylic acids such acetic acid, tartaric acid, citric acid, lactic acid and sulfonic acids. Among the basifying agents, mention may be made, by way of example, of ammonium hydroxide, alkali metal carbonates, alkanolamines such as mono-, di- and triemanolamines and also their derivatives, sodium or potassium hydroxide and compounds of formula below:

R1 R3

N-R-N

R2 R4 wherein R denotes an alkylene such as propylene optionally substituted by a hydroxyl or a C₁-C₄ alkyl radical, and R_ls R₂, R₃ and R4 independently denote a hydrogen atom, an alkyl radical or a Ci-C₄ hydroxyalkyl radical, which may be exemplified by 1,3-propanediamine and derivatives thereof. Arginine, urea and monoemanolamine are preferable.

(Keratin Fiber Treatment Process)

The process for treating keratin fibers according to the present invention can be performed by: applying onto the keratin fibers the composition as described above;

then placing the keratin fibers in an occlusive space; and

then heating the keratin fibers to from 50 to 250 °C,

According to the present invention relating to the treatment process for keratin fibers, keratin fibers such as hair are subjected to a specific heating process which is performed in an occlusive space.

The heating process can be performed by any heating means which can be freely controlled to realize the temperature desired for the process.

The heating process may preferably be performed by using a special heating device or devices that can form an occlusive space to restrict the evaporation of evaporable components such as water in the above-described composition from keratin fibers and keep a predetermined temperature in the heating device throughout the process.

If the evaporable components such as water in the above-described composition evaporate from the keratin fibers, most of the heat energy applied to the keratin fibers will be consumed by the evaporation, and therefore the temperature of the keratin fibers cannot increase up to the predetermined temperature until all evaporable components in the composition evaporate.

The above heating device may comprise a heat energy source being either in contact with keratin fibers or apart from keratin fibers, and at least one means to form an occlusive space surrounding the keratin fibers. The heat energy source is used to heat keratin fibers. The heat energy source may be at least one heater providing at least one selected from the group consisting of hot air, hot steam, high frequency induction heating, microwave heating, infrared ray irradiation, laser, and flash lamp irradiation.

The occlusive space may be formed by at least one coating means. A plurality of coating means may be used. The coating means may be rigid or flexible.

The coating means may comprise at least one member selected from the group consisting of a film and a sheet. The material of the film or the sheet is not limited. For example, the film or the sheet may comprise a thermoplastic or thermosetting resin, a paper, a textile, a bonnet, a metal foil such as aluminum foil, and the like.

For example, the film or sheet may be set on a heating rod, a heating bar or a heating plate which is covered by keratin fibers.

According to the present invention, the coating means may comprise the heat energy source. Therefore, for example, the film or sheet which includes a heater may be set on a rod, a bar, or a plate which is covered by keratin fibers.

The occlusive conditions can restrict the evaporation of evaporable components such as water in the above-described composition applied to keratin fibers, and therefore the temperature of the keratin fibers can be increased higher than that obtainable by a conventional heating process or device for the keratin fibers in open conditions. Furthermore, the keratin fibers can be heated effectively, and the keratin fibers can be heated evenly.

According to one variation of the present invention, the occlusive space may comprise apertures, the surface area of which is less than 5 %, preferably less than 3 % and more particularly less than 0.5 % of the total surface area of the coating means. According to this variation, the total surface area of the coating means comprises the surface area of, when it is present, an opening means for the coating means. The apertures may be passages, holes or orifices, which may allow an exchange of air between the occlusive space and the exterior thereof, especially when the reaction such as forming vapor inside the occlusive space is too great. On the other hand, a person skilled in the art could form the apertures such that the diffusion of heat in the occlusive space is not impaired. The keratin fibers can be heated at 50 °C to 230 °C, preferably 60 °C to 200 °C, more preferably 60 °C to 150 °C, more preferably 60 °C to 90 °C, during the step of heating the keratin fibers.

The heating process may be performed for an appropriate time which is required to treat the keratin fibers. The time length for the heating process is not limited, but it may be from 1 minute to 2 hours, preferably 1 minute to 1 hour, and more preferably 1 minute to 30 minutes. For example, the time for heating may be from 5 to 20 minutes, preferably 10 to 15 minutes.

The keratin fibers may be rinsed after the step of applying the composition onto the keratin fibers and/or after the step of heating the keratin fibers. According to one embodiment of the process for treating keratin fibers according to the present invention, mechanical tension may be applied to the keratin fibers.

If mechanical tension is provided to keratin fibers, the treatment process according to the present invention may be performed as follows.

First, keratin fibers are subjected to mechanical tension. The mechanical tension can be applied to the keratin fibers by any means to deform the keratin fibers to an intended shape. For example, the mechanical tension may be provided by at least one reshaping or mechanically tensioning means selected from the group consisting of a curler, a roller, a clip, a plate and an iron. The reshaping or mechanically tensioning means may comprise at least one heater as described above. If the keratin fibers are rolled around a curler, this rolling-up may be performed on the entire length of the keratin fibers or, for example, on half the length of the keratin fibers. Depending on, for example, the desired hairstyle shape and amount of curls, the rolling-up may be performed with more or less thick locks.

Next, the above-described composition is applied to the keratin fibers. The application of the composition may be performed by any means, such as a brush and a comb. The keratin fibers to which the mechanical tension has been applied should be treated with the composition. It may be possible that the keratin fibers are left as they are for a certain amount of time, if necessary.

Lastly, the above-described heating process is performed. The heat energy is applied to the keratin fibers under occlusive conditions as described above. This process for permanent deformation of keratin fibers may be performed without any step of oxidizing the keratin fibers. Therefore, the time required for the process according to the present invention can be shorter than that for a conventional process which needs an oxidizing step.

Furthermore, damage to the keratin fibers by the oxidizing step can be avoided. The keratin fibers may be rinsed after the step of applying the composition onto the keratin fibers and/or after the step of heating the keratin fibers.

One embodiment of the treatment process according to the present invention may comprise:

a) a step of placing keratin fibers under mechanical tension by rolling them up on at least one reshaping or mechanically tensioning means so as to form curls;

b) a step of applying the above-described composition to the keratin fibers;

c) an optional step of rinsing the keratin fibers,

d) a step of placing at least one coating means on the reshaping or mechanically tensioning means or vice versa to form one or more occlusive spaces; and

e) a step of heating the keratin fibers at a temperature of between 50 and 250 °C, preferably for 1 minute to 2 hours. However, the time for the heating should not be limited.

In this process, the temperature can be set, adjusted and regulated by using one or more heating means, and may be measured with a thermo-measurement probe such as Digital Surface Sensor Module, reference MT-144, sold by Sakaguchi E.H VOC Corp (Japan), set on the keratin fibers. Normally, the probe is set on a single keratin fiber. However, it is advantageous that the probe be set on the part of the keratin fibers which directly contacts with the occlusive space, and more preferably, the probe be set on the part of the keratin fibers which directly contacts with the occlusive space and forms the curl end of the keratin fibers, if a curler is used.

Preferably, the temperature is measured at atmospheric pressure of 101,325 Pa.

According to the present invention, the temperature of the keratin fibers may be constant with a fluctuation of ± 2 or 3 °C over the head, if the keratin fibers are hair, of an individual, and the probe may be set on any type of keratin fibers.

If the keratin fibers are hair, according to the present invention, the constant temperature with a fluctuation of ± 2 or 3 °C can be obtained for any type of hair, and the temperature of the hair can be controlled to be constant ± 2 or 3 °C during the heating of the hair at a certain temperature. Thus, the hair style becomes uniform and homogeneous for the entirety of the hair, and a further excellent hair style can be finally obtained.

Advantageously, the coating means may comprise one or more thermal insulating materials, and more advantageously, the coating means may consist of the material(s).

The term "thermal insulating material" means any material which has an electric conductivity of 0 to 1 W/m°C (PVC: 0.17 W/m°C).

Preferably, the heating means may be adjusted such that the temperature measured on the keratin fibers is 50°C or more, more preferably 55°C to less than 150°C, and further more preferably less than 100°C. It is preferable that the heating be performed by heating via electrical resistance.

Advantageously, the coating means is impermeable with regard to the composition used in the step b).

In the above embodiment, at least one of the reshaping or mechanical tensioning means and at least one of the covering means may include a heater.

In the above embodiment, "occlusive space" means that when the coating means is placed on the reshaping or mechanical tensioning means, or vice versa, they together form a closed structure in which heat can diffuse, but heat cannot diffuse out of or is difficult to diffuse out of the closed structure. It is preferable that the coating means and the reshaping or mechanical tensioning means can form the occlusive space when they are set on the head, if the keratin fibers are hair. The occlusive space may form a condensation cage in which water and a component or components in the composition used in the step b) may evaporate from the keratin fibers, adhere to the wall of the coating means, and drop onto the keratin fibers. This cycle may be repeated during the heating of the keratin fibers. Thus, the keratin fibers can be always kept wet, and drying and deterioration of the keratin fibers will be prevented. The formation of the occlusive space is an important characteristic of the present invention, because the keratin fibers in the occlusive space can be kept wet and the temperature of the keratin fibers can be kept constant. Preferably, the process of the present invention may comprise an additional step of tightening the coating means on the head of an individual, if the keratin fibers are hair, by an elastic cord, an extensible band, or a stretch.

According to the process of the present invention, because of the occlusive space in which the composition can be continuously condensed on the keratin fibers, the amount of a cosmetic component or components in the composition is advantageously reduced as compared to the processes in the prior art. The amount of the cosmetic component(s) may be 0.3 to 3% by weight of the composition. In a preferred embodiment, a coating means may be placed on each hair curler as the reshaping or mechanically tensioning means, if the keratin fibers are hair. In other words, each of the hair curlers, if two or more hair curlers are used, may be covered individually by a coating means. It is advantageous to cover each hair curler because leaking to the scalp of the composition which has been applied onto keratin fibers in the step b) can be prevented.

In another preferred embodiment, a coating means may cover all hair curlers, if two or more hair curlers are used. In other words, the coating means may cover the entirety of the head if the keratin fibers are hair. Advantageously, the occlusive space formed in the step d) may be maintained during the step e). In other words, the coating means may be removed only after the step e) or after the stopping of the heating in the step e).

If necessary, the composition may be applied to keratin fibers before applying mechanical tension to the keratin fibers. It may be possible that the keratin fibers are left as they are for a certain amount of time, if necessary, before and/or after applying mechanical tension to the keratin fibers, before and/or after applying the above-described composition to the keratin fibers, and before and/or after heating the keratin fibers. After the above step e), if necessary, the keratin fibers may be fixed by oxidation after being taken out from the coating means.

If necessary, before applying the composition comprising at least one natural direct dye to the keratin fibers, it is possible to apply onto the keratin fibers a pretreatment composition comprising no natural direct dye but at least one organic or inorganic salt of a metal as described above. If the pretreatment composition is used, the cosmetic properties, such as the color fastness, of the dyed keratin fibers may be furthermore enhanced.

The amount of the organic or inorganic salt of the above metal in the pretreatment composition may be 0.01 to 20% by weight, preferably 0.1 to 10% by weight, and more preferably 1 to 5% by weight, relative to the total weight of the composition. (Use and Products) The present invention also relates to use of a composition for treating keratin fibers at a temperature from 50 to 250 °C in an occlusive space, comprising at least one natural direct dye as mentioned above. This composition may have the same technical features as those of the composition described above. The present invention also relates to a kit for treating keratin fibers, comprising:

a device comprising

at least one coating means to form an occlusive space, and

at least one heater to heat the keratin fibers to from 50 to 250 °C in the occlusive space;

and

a composition comprising at least 0.1 % by weight relative to the total weight of the composition, of one or more natural dyes.

The coating means and the heater, as well as the composition in the kit, may be the same as those described above.

EXAMPLES

The present invention will be described in more detail by way of examples, which however should not be construed as limiting the scope of the present invention.

Evaluation 1

A dyeing composition A with the following formulation shown in Table 1 was prepared (the unit of the content in Table 1 is grams based on active material as provided).

Table 1

Four hair swatches of natural Caucasian and Chinese hair with 90% white hair were treated with the coloring composition A. As Control 1 , one of the hair swatches was left in an oven during 45 minutes at 40 °C.

As examples of the present invention (Examples 1-3), each of the other three hair swatches was rolled on a curler composed of a 1.7 cm diameter polyethylene cylinder covering an electric resistance. The hair swatch on the curler was further covered with a polyvinylchloride plastic film, and the curler was plugged with electrical connection into a Digital Perm device (Oohiro, model ODIS-2) delivering 10 W of power per curler. Then, the hair swatches were heated under different time and temperature conditions as shown in Table 2.

Table 2

At the end of the developing time, heating of the curler was stopped. Then, after removing the plastic film, the hair was unrolled.

All of the hair swatches were rinsed, washed with a shampoo and then dried under a dryer.

The hair swatches had intense coppery red color. However, it was observed that the hair swatches according to Examples 1 to 3 which had been treated in the occlusive heating conditions under the time and temperature conditions tested according to the present invention had more intense color than the hair swatch according to Control 1 which was left in an oven during 45 minutes at 40°C. Evaluation 2

Coloring compositions B to E with the following formulations shown in Table 3 were prepared (the unit of the content in Table 3 is grams based on active material as provided).

Table 3

B C D E

Bentonite 4.2 g 4.2 g 4.2 g 4.2 g

Benzyl alcohol 2 g 0 g 0 g 0 g

Coco-glucoside 2 g 2 g 2 g 2 g

Denatured alcohol 15 g 15 g 15 g 15 g

Haematoxylon campechianum

oxidized 3 g 4 g 3 g 4 g

Curcurnin 1.5 g - i g 1.5 g

Chlorophyllin - - - 1.5 g

Sodium carbonate 1.5 g i g 1.5 g -

Water QS 100 g QS 100 g QS 100 g QS 100 g

As Examples 4 and 5, two hair swatches of Chinese natural hair with 100% white hair were treated with a composition F with the following formulation shown in Table 4, and then these hair swatches were treated with the dyeing compositions B and C, respectively. The hair swatches were left during 10 minutes at room temperature, and then they were rinsed.

Table 4

On the other hand, as Examples 6 and 7, two hair swatches were treated with the dyeing composition D and E, respectively.

Next, each of the hair swatches according to Examples 4 to 7 was rolled on a curler composed of a 1.7 cm diameter polyethylene cylinder covering an electric resistance. The hair swatch on the curler was further covered with a polyvinylchloride plastic film, and the curler was plugged with electrical connection into a Digital Perm device (Oohiro, model ODIS-2) delivering 10 W of power per curler. Then, the hair swatch was heated for 30 minutes at 60°C.

At the end of the developing time, heating of the curler was stopped. Then after removing the plastic film, the hair was unrolled.

All of the hair swatches were rinsed, washed with a shampoo, rinsed and then dried under a dryer.

It was observed that the hair swatch according to Example 4 which was initially white but was dyed with the composition F and the composition B had very intense black color and the dyeing level was very close to the color of the dark brown pigmented natural Chinese hair swatch as a Control 2. It was also observed in Examples 5 to 7 that deep purple, mahogany and chestnut shades were obtained respectively when the hair swatches were colored with a combination of the composition F and the dyeing compositions C, the dyeing composition D, and the dyeing composition E, respectively.

The hair swatches of Chinese natural hair with 100% white hair were completely covered by each of the colors. Colorimetric measurements (by use of Minolta CM2600d spectrocolorimeter) were performed to corifirm the above observations. The results are shown in Table 5.

Table 5

These colors were resistant to shampooing, and the colored hair swatches had a soft feel. Evaluation 3

Dyeing compositions G and H with the following formulations shown in Table 6 were prepared (the unit of the content in Table 6 is grams based on active material as provided).

Table 6

A hair swatch of natural Caucasian hair with 90% white hair were treated with the above dyeing composition G, and another hair swatch of the same natural Caucasian hair with 90% white hair was treated with the above dyeing composition H. Similarly, a hair swatch of permed Caucasian hair with 90% white hair were treated with the above dyeing composition G, and another hair swatch of the same permed Caucasian hair with 90% white hair was treated with the above dyeing composition H.

As controls (Controls 3 and 4), each of hair swatches of natural and permed Caucasian hair with 90% white was treated with the dyeing composition G and left in an oven during 45 minutes at 40 °C. As examples of the present invention (Examples 8 to 11), each of the natural and permed hair swatches which were treated with the coloring compositions G and H was rolled on a curler composed of a 1.7 cm diameter polyethylene cylinder covering an electric resistance. The hair swatch on the curler was further covered with a polyvinylchloride plastic film, and the curler was plugged with electrical connection into a Digital Perm device (Oohiro, model ODIS-2) delivering 10 W of power per curler. Then, the hair swatch was heated for 30 minutes at 60°C.

At the end of the developing time, heating of the curler was stopped. Then, after removing the plastic film, the hair was unrolled. All of the hair swatches were rinsed, washed with a shampoo, rinsed and then dried under a dryer.

A test for evaluating fastness against six shampoos was then performed on the hair swatches with Elseve multivitamin shampoo (at a rate of 0.4 g of shampoo per gram of hair) and the hair swatches were dried under a dryer after each shampooing.

Colorimetric measurements (by use of Minolta CM2600d spectrocolorimeter) were performed to confirm these observations. The results are shown in Table 7.

Table 7

Evaluation 4 Coloring compositions I to L with the following formulations shown in Table 8 were prepared (the unit of the content in Table 8 is grams based on active material as provided).

Table 8

Four hair swatches of natural and permed Caucasian hair with 90% white hair were treated with the coloring compositions I to L, respectively.

Each of the colored hair swatches were then rolled on a curler composed of a 1.7 cm diameter polyethylene cylinder covering an electric resistance. The hair swatch on the curler was then covered with a polyvinylchloride plastic film, and plugged with electrical connection to a Digital Perm device (Oohiro, model ODIS-2) delivering 10 W of power per curler. The hair swatch was then heated 30 minutes at 90°C. At the end of the time, heating of the curler was stopped. Then, after removing the plastic film, the hair was unrolled. All of the hair swatches were then wiped to eliminate the remaining compositions.

Then, the composition M with the following formulations shown in Table 9 was applied on the hair swatch during 20 minutes under confined heat by means of plastic film and the Digital Perm device according to the above protocol.

Table 9

The hair swatch was then rinsed, washed with a shampoo, rinsed and dried under a dryer.

The hair swatches had intense colors. Additionally, it was observed that each of the hair swatches had distinctly more intense color than a corresponding control hair swatch which was treated with the same coloring composition but was left at ambient temperature for 45 minutes, followed by being treated with the composition M for 20 minutes.

Claims

CLA S

1. A process for treating keratin fibers comprising the steps of:

applying onto the keratin fibers a composition comprising at least 0.1% by weight, relative to the total weight of the composition, of one or more natural dyes;

placing the keratin fibers in an occlusive space; and

heating the keratin fibers to from 50 to 250 °C.

2. The process according to Claim 1, further comprising the step of rinsing the keratin fibers after the step of applying the composition onto the keratin fibers and/or after the step of heating the keratin fibers.

3. The process according to Claim 1 or 2, further comprising providing the keratin fibers with mechanical tension.

4. The process according to any one of Claims 1 to 3, wherein the occlusive space is formed by at least one coating means.

5. The process according to Claim 4, wherein the coating means is rigid or flexible.

6. The process according to Claim 4 or 5, wherein the coating means comprises at least one member selected from the group consisting of a film and a sheet.

7. The process according to any one of Claims 1 to 6, wherein the keratin fibers are heated at 60 °C to 150 °C during the step of heating the keratin fibers.

8. The process according to any one of Claims 1 to 7, wherein the keratin fibers are heated by at least one heater providing at least one selected from the group consisting of hot air, hot steam, high frequency induction heating, microwave heating, infrared ray irradiation, laser, and flash lamp irradiation.

9. The process according to Claim 8, wherein the coating means comprises the heater.

10. The process according to any one of Claims 1 to 9, wherein the natural dye is chosen

among curcurninoids, santalins, chlorophyllin, haematoxylin, haematein, brazilein, brazilin, sorghum, laccaic acid, lawsone, juglone, alizarin, purpurin, carminic acid, kermesic acid, purpurogallin, protocatechaldehyde, indigo, isatin, spinulosin, apigenidin, orcein, betanin, flavonoids, anthocyans, and extracts or decoctions containing these compounds.

11. The process according to any one of Claims 1 to 10, wherein the composition comprises the natural dye(s) in an amount of 0.1 to 30% by weight, relative to the total weight of the composition.

12. The process according to any one of Claims 1 to 11,. wherein the composition comprises at least one organic compound which is liquid at 25 °C and atmospheric pressure (760 mmHg) with a value of Hansen solubility parameter (δΗ) of less than 16 MPa at 25 °C.

Process according to claim 12, wherein the organic compound is chosen among C₅-C₃₀ alkanols; alcohol ethers, particularly Q-C₄ ether of C₅-C₃₀ alcohols, preferably saturated, optionally interrupted by one or more non vicinal ether groups; aliphatic esters of Q-C4 carboxylic acids and C₃-C₁₀ monoalcohols or C₃-C₁₀ polyols, optionally interrupted by one or more non vicinal ether groups; aromatic ethers, particularly Ce-Qo, of Ci-C₆ alkyl, optionally bearing a hydroxyl group; alkanol with aryl or oxyaryl substituting group, particularly wherein the aryl part is a C₆-C₁₀ aryl, preferably C₆, and the alkanol is a Ci-C₄ alkyl; lactones particularly of formul

wherein R' represents a hydrogen, a (Q- ) alkyl group, a (Ct-Q) hydroxyalkyl group, n means 1, 2 or 3; alkylene carbonate of formula (II) :

wherein R" represents a hydrogen atom, a ( -Cs) alkyl group, a (Ci-C₄) hydroxyalkyl group.

The process according to any one of Claims 1 to 13, further comprising the step of treating the keratin fibers with a composition comprising at least one organic or inorganic salt of a metal chosen among iron, copper, zinc, tin, aluminum, manganese, silver, preferably, zinc, and manganese.

The process according to Claim 14, wherein the organic or inorganic salt of a metal is chosen among zinc or manganese chloride, sulfate, gluconate, and glycinate.

A kit for treating keratin fibers, comprising:

a device comprising

at least one coating means to form an occlusive space, and

at least one heater to heat the keratin fibers to from 50 to 250 °C in the occlusive space; and

a composition comprising at least one natural dye in an amount of 0.1% by weight or more relative to the total weight of the composition.