WO2011074138A1

WO2011074138A1 - Process for treating keratin fibers

Info

Publication number: WO2011074138A1
Application number: PCT/JP2009/071728
Authority: WO
Inventors: Maxime De Boni; Hiroshi Takahashi
Original assignee: L'oreal
Priority date: 2009-12-18
Filing date: 2009-12-18
Publication date: 2011-06-23
Also published as: JP2013514261A

Abstract

The present invention relates to a process for treating keratin fibers comprising the steps of: applying onto the keratin fibers a composition comprising at least one colorless hydrophobic molecule; then placing the keratin fibers in an occlusive space; and then heating the keratin fibers, wherein the composition contains neither a reducing agent nor a source of carbonate ions of the formula: wherein X is a group selected from the group consisting of O^-, OH, NH₂, O-OH, and O-COO^-. The present invention also relates to the composition itself and a kit to be used for the above process.

Description

DESCRIPTION

PROCESS FOR TREATING KERATIN FIBERS

TECHNICAL FIELD

The present invention relates to a process for treating keratin fibers such as hair, as well as a composition and a kit to be used for the process.

BACKGROUND ART

Due to the many physical stresses (UV, shampoo, brushing, and the like) and chemical stresses (coloration, perm, relaxing,

pollution, and the like) that keratin fibers such as hair must undergo daily, research for effectively repairing damaged keratin fibers has become important in the cosmetic treatments for keratin fibers.

Repairing damaged keratin fibers is only worthwhile if a real sensation of return to the original state of the keratin fibers is perceived. Furthermore, the repairing treatment should be effective against various stresses, as mentioned before.

Technologies (compositions and/or processes) known as treatments for damaged keratin fibers that have been proposed are still insufficient insofar as they are often temporary and do not achieve proper recovery of keratin fiber integrity. In addition, there is still a strong interest in finding efficient protective systems for the keratin fibers.

DISCLOSURE OF INVENTION

Hydrophobic molecules might be useful to at least partially recover the hydrophobicity of keratin fibers and fill gaps in damaged parts of the keratin fibers.

However, due to their hydrophobic nature, it is difficult for the hydrophobic molecules penetrate into the keratin fibers or deposit on the keratin fibers. Therefore, their benefits on keratin fibers are insufficient. This also means that the efficiency of the cosmetic treatment of keratin fibers using a hydrophobic molecule is low and a large amount of hydrophobic molecule is necessary in the formulation used for the cosmetic treatment .

Thus, an objective of the present invention is to provide a new treatment process for keratin fibers such as hair, using a

hydrophobic molecule, even with a relatively small amount thereof, which provides the keratin fibers with good cosmetic effects, in particular superior protecting effects as well as superior

repairing or recovering effects, which can be effective against various stresses for a long time.

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

applying onto the keratin fibers a composition comprising at least one colorless hydrophobic molecule;

then placing the keratin fibers in an occlusive space; and then heating the keratin fibers,

wherein

the composition contains neither a reducing agent nor a source of carbonate ions of the formula:

wherein

X is a group selected from the group consisting of 0^", OH, NH₂, 0- OH, and 0-COO^".

The above 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 .

Mechanical tension may be provided to the keratin fibers. The mechanical tension may be provided by using at least one

reshaping means selected from the group consisting of a curler, a roller, a plate and an iron.

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. In the above process, the keratin fibers may be heated at 45°C to 250°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 coating means and/or the reshaping means may comprise the heater.

The hydrophobic molecule may have a molecular weight of 5000 or less .

The hydrophobic molecule may have a log P value of higher than

0.5.

Preferred log P value is between 0.55 and 26.0, and more

preferably between 0.60 to 12.0, and more preferably between 0.65 to 5.

The hydrophobic molecule may have at least one aromatic group.

The hydrophobic molecule may have at least one functional group which is capable of forming a hydrogen bond.

Preferred hydrophobic molecules are not salts.

The composition may comprise the colorless hydrophobic molecule in an amount of 0.01 to 20% by weight relative to the total weight of the composition. The pH of the composition may range from 4 to 11.

Another aspect of the present invention is a composition for treating keratin fibers to be heated in an occlusive space, comprising at least one colorless hydrophobic molecule,

wherein

X is a group selected from the group consisting of 0^", OH, NH₂, 0- OH, and O-COO^". 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 in the occlusive space;

and

a composition comprising at least one colorless hydrophobic molecule,

wherein

X is a group selected from the group consisting of 0^~, OH, NH₂, 0- OH, and O-COO^".

BEST MODE FOR CARRYING OUT OF THE INVENTION

After diligent research, the inventors have discovered that it is possible to provide keratin fibers such as hair with good

cosmetic effects, using a hydrophobic molecule, and in particular superior protecting effects as well as superior repairing or recovering effects, which can be effective against various stresses for a long time, by using a composition comprising a colorless hydrophobic molecule in association with a specific heating process for the keratin fibers.

The above specific heating process is performed in a closed or occlusive environment, which limits the evaporation of water or moisture from the keratin fibers and maintains the keratin fibers at higher temperature preferably in the wet state. Accordingly, the keratin fibers can be evenly heated, and the hydrophobic molecule can easily penetrate into or deposit onto the keratin fibers such that it can remain in or on the keratin fibers for a long time even after some stresses such as shampooing.

Since a colorless hydrophobic molecule can easily stay on or in the keratin fibers, the process according to the present

invention can exhibit good cosmetic effects, in particular good mechanical properties, by using even a relatively small amount of colorless hydrophobic molecule as compared to a conventional process in which it is difficult for a hydrophobic molecule to stay on or in the keratin fibers.

The composition used in the present invention must not contain any reducing agents such as thiol-compounds . Therefore, malodor derived from the reducing agents can be prevented. Furthermore, the composition used in the present invention must not contain any carbonate ion source as defined above. Therefore, cosmetic treatment is more effective, because there is no possibility of producing carbon dioxide which may form a foam that may inhibit the deposition or penetration of the hydrophobic molecule on or into the keratin fibers.

(Composition)

The composition used for the present invention comprises at least one colorless hydrophobic molecule.

The term "colorless" here means that the hydrophobic molecule has no inherent color. Therefore, for example, pigments do not correspond to hydrophobic molecules even if they are inherently hydrophobic or surface-treated to be hydrophobic.

The term "molecule" means a substance with a low molecular weight, and therefore, a polymer does not correspond to a molecule even if it is inherently hydrophobic or surface-treated to be

hydrophobic. Thus, the colorless hydrophobic molecule according to the present invention preferably has a molecular weight of 5000 or less, more preferably 3000 or less, and even more

preferably 1000 or less.

The colorless hydrophobic molecule used in the present invention may preferably have a log P value of higher than 0.5.

In the present invention, the logP value classically represents the partition coefficient of a molecule between octanol and water. This value can be obtained by using the method described by

Meylan and Howard in "Atom/Fragment contribution method for estimating octanol-water partition coefficient" (J. Pharm. Sci. 84:83-92, 1995). This value can also be calculated using

numerous software programs that determine logP values based on the chemical structure of the molecule of interest. Epiwin from Environmental Office of the United States is one example of such a software program.

The colorless hydrophobic molecule used in the present invention may preferably have at least one aromatic group. The aromatic group may be a monovalent or divalent aromatic hydrocarbon group such as a phenyl and a phenylene; a monovalent or divalent condensed aromatic hydrocarbon group such as a naphthalenyl and an indenyl; a monovalent or divalent aromatic heterocycle group such as furanyl, pyrrolyl, imidazolyl, pyrazolyl, pyridinyl, pyridazinyl, pyrimidinyl and pyrazinyl; and a monovalent or divalent aromatic condensed heterocycle group such as an indolyl, benzofuranyl, quinolinyl, isoquinolinyl, quinoxalinyl, chromanyl, puteridinyl and dihydropteridinyl .

The colorless hydrophobic molecule used in the present invention may preferably have at least one functional group which is capable of forming a hydrogen bond. As an example of the

functional group, mention may be made of a hydroxyl group, a thiol group, an amino group, an amido group, and the like. As the functional group, a hydroxy group is preferable.

Among the suitable colorless hydrophobic molecules used in the present invention, hydrophobic antioxidants, hydrophobic

antipollution agents, hydrophobic antiradical agents and

hydrophobic vitamins are preferred. These compounds may be natural or synthetic.

Examples of the colorless hydrophobic molecules which may be used in the present invention may be given in the table below:

Table

* calculated with Epiwin according to chemical structures The colorless hydrophobic molecule may be present in an amount ranging from 0.01% to 20% by weight, and preferably from 0.1% to 5% by weight, such as from 0.5% to 3% by weight, relative to the total weight of the composition.

The composition used for the present invention contains neither a reducing agent nor a source of carbonate ions of the formula:

wherein

X is a group selected from the group consisting of 0^", OH, NH₂, 0- OH, and O-COO^".

The pH of the composition may range from 4 to 11, preferably between 4.0 and 9.0, and more preferably between 6.0 to 8.0.

Since the pH of the composition is not relatively high or low, damage to the keratin fibers by the composition can be reduced.

In order to adjust the pH, an acidic or alkali agent (s) other than sources of ions of the invention may be used alone or in combination. The amount of the acidic or alkali agent (s) is not limited, but may be from 0.1 to 5% by weight relative to the total weight of the composition. As the acidic agents, mention may be made of any inorganic or organic acids which are commonly used in cosmetic products such as citric acid, lactic acid, phosphoric acid or hydrochloric acid (HC1) . HC1 is preferable. As the alkali agents, mention may be made of any inorganic or organic basic agents which are commonly used in cosmetic products such as ammonia; alcanolamines such as mono-, di- and tri- ethanolamine, isopropanolamine; sodium and potassium hydroxides; urea, guanidine and their derivatives; basic amino acids such as lysine or arginine; and diamines such as those described in the structure below:

R1 R3

\ /

N-R-N

/ \

R2 R4

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

monoethanolamine are preferred.

The composition used for the present invention may also comprise one or more additional cosmetic agent (s). The amount of the additional cosmetic agent (s) is not limited, but may be from 0.1 to 10% by weight relative to the total weight of the composition. The cosmetic agent (s) may be selected from the group consisting of volatile or non volatile, linear or cyclic, amine-type or not, silicones, cationic, anionic, non ionic or amphoteric polymers, peptides and derivatives thereof, protein hydrolyzates, synthetic or natural waxes, swelling agents and penetrating agents, as well as other active compounds, such as anionic, cationic, non ionic, amphoteric or zwitterionic surfactants, agents for combating hair loss, anti-dandruff agents, associative-type or not, natural or synthetic thickeners, suspending agents, sequestering agents, opacifying agents, dyes, sunscreen agents, fillers, vitamins or provitamins, mineral, vegetable or synthetic oils, as well as fragrances, preserving agents, stabilizers, and mixtures thereof.

The vehicle for the composition used for the present invention is preferably an aqueous medium consisting of water and may

advantageously contain one or several cosmetically acceptable organic solvents, which particularly include alcohols, such as ethyl alcohol, isopropyl alcohol, benzyl alcohol and phenylethyl alcohol, or polyols or polyol ethers, such as ethylene glycol monomethyl, monoethyl and monobutyl ethers, propylene glycol or ethers thereof, such as propylene glycol monomethylether, butylene glycol, dipropylene glycol as well as diethylene glycol alkyl ethers, such as diethylene glycol monoethylether or

monobutylether . The water may be present in a concentration of from 10 to 90% by weight relative to the total weight of the composition. The organic solvent (s) may then be present in a concentration of from 0.1 to 20% by weight, and preferably from 1 to 10% by weight relative to the total weight of the composition.

The composition used in the present invention may exist in any form such as a lotion, a gel, thickened or not, or a cream.

(Keratin Fiber Treatment Process)

The process for treating keratin fibers according to the present invention can be performed by applying onto the keratin fibers a composition comprising at least one colorless hydrophobic molecule, as described above; then placing the keratin fibers in an occlusive space; and then heating the keratin fibers,

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 variant 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 variant, 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 45°C to 250°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 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.

(Permanent Deformation Process for Keratin Fiber)

According to the present invention relating to the treatment process for keratin fibers, the keratin fiber may be subjected to mechanical tension which is typically used for permanent

deformation .

The permanent deformation process for keratin fibers when

mechanical tension is applied to keratin fibers may be performed as follows.

First, keratin fibers are subjected to mechanical tension for deformation. 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 means selected from the group consisting of a curler, a roller, a clip, a plate and an iron. The reshaping 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.

One embodiment of the hair treatment process according to the present invention may be a process for reshaping or permanent deforming keratin fibers, in particular hair, comprising:

a) a step of placing the 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 45 ± 2 or 3°C and 250 ± 2 or 3°C for 1 minute to 2 hours.

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 is set on the part of the keratin fibers which directly contacts with the occlusive space, and more preferably, the probe is 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 101325 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 more 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 /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 is 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 deteriorating of the keratin fibers will be prevented.

The formation of 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 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 3wt% 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 stop 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.

( Products )

The present invention also relates to a composition for treating keratin fibers to be heated in an occlusive space, comprising at least one colorless hydrophobic molecule,

wherein

This composition may not need to be used in combination with an oxidizing agent which is used in a conventional permanent

deformation of keratin fibers. Therefore, if keratin fibers should be permanently deformed, the composition may be used in one step, whereas two steps (reducing step and oxidizing step) are necessary in the conventional permanent deformation of keratin fibers.

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 reshaping means to provide the keratin fibers with mechanical tension, at least one coating means to form an occlusive space, and at least one heater to heat the keratin fibers in the

occlusive space;

and

a composition comprising at least one colorless hydrophobic

molecule wherein the composition contains neither a reducing agent nor a source of carbonate ions of the formula:

wherein

X is a group selected from the group consisting of 0^", OH, NH₂, O-OH, and 0-COO^".

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.

Composition 1

A hair treatment composition (referred to as "Composition 1") having the following composition shown in Table 1 was prepared (active ingredients in wt %) .

Table 1

Example 1 Composition 1 was applied to a lg natural Japanese hair swatch previously wrapped on a 1.7 cm heating perm-roller. Then, the perm-roller was covered by a plastic film and plugged into a Digital Perm Machine (Oohiro, model ODIS-2) . After the heating process at 90°C for 15 minutes, the hair was rinsed, removed from the perm-roller and dried.

The hair was resistant against various external aggressions.

The following composition was prepared (active ingredients in wt %) :

Composition 2

A hair treatment composition (referred to as "Composition 2 " ) having the following composition shown in Table 2 was prepared (active ingredients in wt %) .

Table 2

Example 2

Composition 2 was applied to a lg Japanese hair swatch. Then, the hair was wrapped by a plastic film and covered by a flexible heating film (FTH-050 from Tokyo Technological Labo) . The hair was heated in occlusive conditions for 10 minutes at 90°C. After the heating step, the hair was rinsed and dried.

The hair was resistant against various external aggressions.

Claims

A process for treating keratin fibers comprising the steps of:

applying onto the keratin fibers a composition comprising least one colorless hydrophobic molecule;

wherein

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 45°C to 250°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.

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

The process according to any one of Claims 1 to 9, wherein the hydrophobic molecule has a molecular weight of 5000 or less .

11. The process according to any one of Claims 1 to 10, wherein the hydrophobic molecule has a log P value of higher than 0.5.

12. The process according to any one of Claims 1 to 11, wherein the hydrophobic molecule has at least one aromatic group.

13. The process according to any one of Claims 1 to 12, wherein the composition comprises the colorless hydrophobic molecule in an amount of 0.01 to 20% by weight relative to the total weight of the composition.

14. A composition for treating keratin fibers to be heated in an occlusive space, comprising at least one colorless

hydrophobic molecule,

wherein

X is a group selected from the group consisting of 0^", OH, NH₂, O-OH, and O-COO^".

15. 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 in the

occlusive space;

and

a composition comprising at least one colorless hydrophobic molecule, wherein

wherein

X is a group selected from the group consisting of 0^", OH, NH₂, 0-OH, and O-COO^".