WO2013125052A1 - 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 0.01% by weight, relative to the total weight of the composition, of one or more synthetic direct 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 direct 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, and which can provide the skin or scalp with less stains.

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 dye 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 dyeing 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.

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.

In addition, some direct dyes can cause staining of the skin or scalp.

There are, therefore, real needs to develop hair dyeing methods, using composition(s) containing direct 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), respecting the nature of the hair, and less staining the skin or scalp.

DISCLOSURE OF INVENTION

Thus, an objective of the present invention is to provide a dyeing process which is based on direct 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 and/or less stains to the skin or scalp.

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 0.01% by weight relative to the total weight of the composition, of one or more synthetic direct 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 synthetic direct dye may be selected from the group consisting of hydrophilic synthetic direct dyes selected from the group consisting of cationic synthetic direct dyes, nonionic synthetic direct dyes and anionic synthetic direct dyes; and hydrophobic synthetic direct dyes.

The hydrophobic synthetic direct dye may be selected from the group consisting of nonionic synthetic direct dyes with a logP of at least 2. The composition may comprise the synthetic direct 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 of Hansen solubility parameter (δΗ) of

1 Γ)

less than 16 MPa at 25 °C. This organic compound may be chosen among C₅-C₃₀ alkanols; alcohol ethers, particularly CrC₄ 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-Q0 polyols, optionally interrupted by one or more non vicinal ether groups; aromatic ethers, particularly Ce-Cio, of Q-Q 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 formula (I)

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

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

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 synthetic direct dye as mentioned above, in an amount of 0.01 % by weight or more, relative to the total weight of the composition. The composition may comprise at least one oxidizing agent.

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 synthetic direct dye as previously defined, in an amount of 0.01% 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 synthetic direct 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, and which can provide the skin or scalp less stains.

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 0.01% by weight relative to the total weight of the composition, of one or more synthetic direct dyes;

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 root to tip), resistance to external factors or agents such as a shampoo, and only little damage, and can provide the skin or scalp with less stains. (Composition)

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

The hydrophilic direct dye can be selected from the group consisting of cationic synthetic direct dyes, nonionic synthetic direct dyes, and anionic(acidic) synthetic direct dyes. It is preferable that the hydrophilic synthetic direct dyes have a logP value of less than 2.

As used herein, the logP value conventionally represents the partition coefficient of the dye between octanol and water. The logP value may be calculated according to the method described in Meylan & Howard, Atom/Fragment contribution method for estimating octanol- water partition coefficient, J. Pharm. Sci., 84, 83-92 (1995). This value may also be calculated using a range of commercially available software that determines the logP value as a function of the structure of a molecule, for example, Epiwin software from the United States Environmental Protection Agency.

Non-limiting examples of such hydrophilic dyes include neutral, anionic(acidic), and cationic dyes such as azo, methine, carbonyl, azine, nitro(hetero)aryl types or tri(hetero)arylmethane direct dyes, porphyrins and phthalocyanines, 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 methines 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 diphenylarnines); indophenols;

indoanilines. As regards the dyes of the family of the carbonyls, mention may be made, for example, of synthetic dyes chosen from acridone, benzoquinone, anthraquinone, naphthoquinone,

benzanthrone, anthranthrone, pyranthrone, pyrazolanthrone, pyrimidinoanthrone, flavanthrone, indanthrone, flavone, (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 ρο η^η or phthalocyanine 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.

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, mdoamine, phmalocyanine and porphyrin direct dyes, alone or as mixtures. More preferably still, these synthetic direct dyes are chosen from nitrobenzene dyes, azo, azomethine or methine direct dyes and tetraazacarbocyanines (tetraazapentamethines); alone or as mixtures. Mention may be made, among the azo, azomethine, methine or tetraazapentamethine direct dyes which can be used according to the invention, of the cationic dyes described in Patent

Applications WO 95/15144, WO 95/01772 and EP 714 954; FR 2 189 006, FR 2 285 851 , FR-2 140205, EP 1 378 544 and EP 1 674 073.

Thus, mention may very particularly be made of the cationic direct dyes corresponding to the following formulae:

in which:

D represents a nitrogen atom or the -CH group,

Ri and R₂, which are identical or different, represent a hydrogen atom; a Ci-C₄ alkyl radical which can be substituted by a -CN, -OH or -NH₂ radical or can form, with a carbon atom of the benzene ring, an optionally oxygen-comprising or nitrogen-comprising heterocycle which can be substituted by one or more Q-Q alkyl radicals; or a 4'-arninophenyl radical,

R₃ and R'₃, which are identical or different, represent a hydrogen atom, a halogen atom chosen from chlorine, bromine, iodine and fluorine, a cyano radical, a C₁-C₄ alkyl radical, a C1-C4 alkoxy radical or an acetyloxy radical, X^" represents an anion, preferably chosen from chloride, methyl sulphate and acetate,

A represents a group chosen from the following structures:

in which R4 represents a Ci-C₄ alkyl radical which can be substituted by a hydroxyl radical;

in which:

R₅ represents a hydrogen atom, a Q-C₄ alkoxy radical or a halogen atom, such as bromine, chlorine, iodine or fluorine,

¾ represents a hydrogen atom or a Q-C₄ alkyl radical or forms, with a carbon atom in the benzene ring, a heterocycle which optionally comprises oxygen and/or is optionally substituted by one or more Q-C₄ alkyl groups,

R₇ represents a hydrogen atom or a halogen atom, such as bromine, chlorine, iodine or fluorine, Di and D₂, which are identical or different, represent a nitrogen atom or the -CH group, m = 0 or 1,

X^" represents a cosmetically acceptable anion preferably chosen from chloride, methyl sulphate and acetate,

E represents a group chosen from the following structures:

in which R' represents a C₁-C₄ alkyl radical;

when m = 0 and when D₁ represents a nitrogen atom, then E can also denote a group with the following structure:

R'

N

N+

I

R'

in which R' represents a C₁-C₄ alkyl radical. Thus, the hydrophilic direct dyes can be chosen for example, from the following direct dyes.

toluene

The fol

X^" represents an anion preferably chosen from chloride, iodide, methyl sulphate, ethyl sulphate acetate.

It is preferable that the hydrophobic synthetic direct dye have a logP value of at least 2. Examples of the hydrophobic synthetic direct dye include those listed in the following table.

Solvent Blue 134 6.27

Solvent Blue 14 8.18

Disperse Blue 14 4.25

Solvent Red 2 5.35

Solvent Brown 5 5.98

Solvent Green 5 8.55

Solvent Orange 2 3.86 Solvent Orange 1 3.85

Disperse Orange 24 -γΟ 3.21 o

Solvent Orange 63 7.02

Solvent Red 49 6.63

Solvent Red 1 3.39

Solvent Red 26 7.07

Solvent Red 27 7.62

Solvent Red 18 8.16 Solvent Red 23 5.58

Solvent Red 4 4.48

Disperse Orange 7 4.40

Disperse Blue 72 6.24

Disperse Violet 26 5.19

Disperse Yellow 16 3.89

Disperse Yellow 82 3.68 Disperse Yellow 54 4.76

Solvent Yellow 29 17.37

Solvent Yellow 163 7.94

Solvent Yellow 3 4.29

Solvent Yellow 56 5.27

Solvent Yellow 18 4.98

Solvent Yellow 98 4.5

Solvent Yellow 12 5.43

Solvent Yellow 14 3.31 Disperse Red 13 5.22

CI

Disperse Green 9 4.23

Disperse Blue 148 4.81

Disperse Violet 63 5.30

Disperse Blue 60 3.38

Solvent Orange 15 3.90

In some embodiments, the logP value of the hydrophobic synthetic direct dyes is greater than 4, preferably greater than 6. The synthetic direct dye may be selected from fluorescent dyes. Two or more types of the fluorescent dye may be used in combination.

The use of some fluorescent dyes may make it possible to obtain, on dark hair, colors which are more visible than with conventional hydrophilic or hydrophobic direct dyes. Furthermore, these fluorescent dyes, when applied to dark hair, may also make it possible to lighten the hair without damaging it.

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 of the present disclosure, also known under the name of "brighteners", or "fluorescent brighteners", or "fluorescent brightening agents" or "F WA", or "fluorescent whitening agents", or "whiteners", or "fluorescent whiteners", 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. Soluble fluorescent compounds that may especially be mentioned include those belonging to the following families: naphthalimides, coumarins, xanthenes and in particular

xanthenodiquinolizines and azaxanthenes; naphtholactams; azlactones; oxazines; thiazines;

dioxazines; azo compounds; azomethines; methines; pyrazines; stilbenes; ketopyrroles; pyrenes. If present, the fluorescent dyes are preferred, more particularly, those re-emitting orange-colored fluorescent light.

The composition used for the present invention contains the synthetic direct dye(s) in an amount of 0.01% by weight or more, and may contain, for example, 0.01 to 30% by weight, preferably 0.1 to 20% by weight, and more preferably 1 to 10% by weight, relative to the total weight of the composition.

The compositions used for the present invention may also contain at least one additional dye such as at least a natural direct dye. As natural dye, mention may be made of quinone dyes (such as lawsone and juglone), alizarin, purpurin, laccaic acid, carminic acid, kermesic acid, purpurogallin, protocatechaldehyde, indigo, sorghum, isatin, betanin, curcuminoids (such as curcumin), spinulosin, various types of chlorophyll and chlorophyllin, hematoxylin, hematein, brazilein, brazilin, safflower dyes (such as carmamin), flavonoids (such as rutin, quercetin, catechin, epicatechin, morin, apigenidin, and sandalwood), anthocyans (such as apigeninidin and apigenidin), carotenoids, orceins, santalins and cochineal carmine.

The composition used for the present invention may contain the natural 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.

The composition used for the present invention may also contain at least one additional dye ■chosen among the oxidative dyes. More particularly, if present, the oxidation dye comprises 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, ortho-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.

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 functioning as an organic solvent.

1/2

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 MPa^1/2 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 CrC₄ 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 C]-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 C₁-C₄ alkyl; lactones particularly of formula (I):

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

wherein R" represents a hydrogen atom, a (CrC₈) alkyl group, a 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 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 value of the component δΗ of the Hansen solubility parameter as previously defined. By way of example, mention may be made of Ci-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. 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. 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 tMckening 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, -S(0)₂0^', -OS(0)₂0H, -OS(0)₂0\ -P(0)OH₂, -P^O^", -P(0)0₂ ^', -P(OH)₂, =P(0)OH, -P(OH)<T, =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, alkylamido 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 allcaline 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-emanolarnine salts, mono-, di- or tri-isopropanolamine salts, and the salts of 2-amino-2-methyl- 1 -propanol, 2-amino-2-methyl- 1 ,3 -propanediol and tris(hydroxy-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-propylmo holine.

(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)alkylamido(C₁-C₆)alkyl sulfobetaines.

Among the amine derivatives, mention may be made of the products sold under the name MIRANOL, 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 tetraalkylarnmonium, alkylamidoalkyltrialkylammonium, trialkylbenzylarnmonium, Irialkymyckoxyalkylammonium 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 more 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 as 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

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

preferably60 °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 f om 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.

(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 synthetic direct dye as mentioned above in an amount of 0.01% by weight relative to the total weight of the composition. This composition may have the same technical features as those of the

composition described above. The composition may comprise at least one oxidizing agent.

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 0.01% by weight relative to the total weight of the composition, of one or more synthetic direct dyes. The composition may optionally comprise an oxidizing agent.

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

Two hair swatches of natural or permed Caucasian hair with 90% white hair were treated with Nuancelle Mandarin Orange (a composition comprising an anionic synthetic direct dye) sold by L'Oreal Professional. Two swatches of these colored natural or permed hair, were left in an oven during 45 minutes at 40°C.

As a control (Control 1), each of one of the natural hair swatches and one of the permanent waving treated hair swatches was heated in an oven for 15 minutes at 45 °C.

As an example of the present invention (Example 1), each of the other natural hair swatch and the other permed hair swatch was rolled on a curler composed of a 1.7 cm diameter polyethylene cylinder covering an electric resistance. Then, 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 15 minutes at 90 °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.

It was found that the natural hair swatch and the permanent waving treated hair swatch according to Control 1 had coppery color and coppery red color, respectively. It was also found that both the natural and permed hair swatches according to Example 1 had coppery red color. The color of the hair swatches according to Example 1 was less selective and more intense than those of the hair swatches according to Control 1.

Evaluation 2

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 material as provided).

Table 1 A

Acid orange 7 (dye) 0.2 g

Acid violet 43 (dye) 0.2 g

Acid yellow 23 (dye) 0.4 g

Ethanol 24 g

Hydroxyethyl Cellulose (MW 1,300,000) 1.2 g

Xanthan gum 1.4 g

pH agent QS pH - 2.7

Water QS 100

A couple of hair swatches of natural or permed Caucasian hair with 90% white hair were treated with the dyeing composition A. As an example of the present invention (Example 2), each of the natural hair swatch and the other permanent waving treated hair swatch was rolled on a curler composed of a 1.7 cm diameter polyethylene cylinder covering an electric resistance. Then, 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 15 minutes at 90 °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.

It was observed that both the natural hair swatch and the permed hair swatch according to Example 2 had intense, fast and stainless color. Evaluation 3

Dyeing compositions B to D with the following formulations shown in Table 2 were prepared (the unit of the content in Table 2 is grams based on material as provided).

Table 2

Three hair swatches of natural or permed Caucasian hair with 90% white hair were treated with the coloring compositions B to D, respectively.

As examples of the present invention (Examples 3-5), each of the natural and permed hair swatches was rolled on a curler composed of a 1.7 cm diameter polyethylene cylinder covering an electric resistance. Then, 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.

The colors of the hair swatches according to Examples 3 to 5 were intense with a good fastness and fast, and the colored hair swatches had a very soft feel. Evaluation 4

A dyeing composition E with the following formulation shown in Table 3 was prepared (the unit of the content in Table 3 is grams based on material as provided).

Table 3 E

Disperse red 13 (dye) 0.5 g

Benzyl alcohol 5 g

Ethanol 15 g

Frangrance qs

Thickening agent qs

Water QS 100 g

A couple of hair swatches of natural or permed Caucasian hair with 90% white hair was treated with the dyeing composition E. As an example of the present invention (Example 6), each of the natural hair swatch and the permed hair swatch was rolled on a curler composed of a 1.7 cm diameter polyethylene cylinder covering an electric resistance. Then, 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 90 °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.

The colors of the hair swatches according to Example 6 were intense red with a good fastness, and the colored hair swatches had a very soft feel.

Claims

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

applying onto the keratin fibers a composition comprising at least 0.01 % by weight, relative to the total weight of the composition, of one or more synthetic direct 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 synthetic direct dye is

selected from the group consisting of hydrophilic synthetic direct dyes selected from the group consisting of cationic synthetic direct dyes, nonionic synthetic direct dyes, and anionic synthetic direct dyes; and hydrophobic synthetic direct dyes.

11. The process according to Claim 10, wherein the hydrophobic synthetic direct dye is

selected from the group consisting of nonionic synthetic direct dyes with a logP of at least

2.

12. The process according to any one of Claims 1 to 11, wherein the composition comprises the synthetic direct dye(s) in an amount of 0.01 to 30% by weight, relative to the total weight of the composition.

13. The process according to any one of Claims 1 to 12, 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^1/2 at 25°C.

14. Process according to claim 13, wherein the organic compound is chosen among C₅-C₃o alkanols; alcohol ethers, particularly -C₄ ether of C₅-C₃₀ alcohols, preferably saturated, optionally interrupted by one or more non vicinal ether groups; aliphatic esters of -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- o, 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 C₁-C₄ alkyl; lactones particularly of formul

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

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

15. Process according to any one of claims 1 to 14, wherein the composition comprises at least one oxidizing agent.

16. 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 synthetic direct dye in an amount of 0.01% by weight or more, relative to the total weight of the composition.