DYEING OR LIGHTENING PROCESS USING A HAND-HELD STYLING DEVICE AND A SUBSTRATE

Abstract

The present invention relates to the use, for dyeing or lightening keratin fibres, in particular human keratin fibres such as the hair, of a hand-held styling apparatus (1) equipped with at least one treatment surface (2d, 3d) partially or totally covered with at least one substrate (6) comprising a surface (6a) coated with at least one layer (6b) containing one or more dyes, preferably chosen from oxidation dyes and/or direct dyes, and/or one or more oxidizing agents. The invention also relates to an assembly (11, 24, 26) intended for dyeing or lightening keratin fibres, in particular human keratin fibres such as the hair, comprising at least one aqueous composition and at least one hand-held styling device (1) as defined above.

Claims

1. Process for dyeing and/or lightening keratin fibres, in particular human keratin fibres such as the hair, using, on said fibres, at least one aqueous composition and at least one hand-held styling device (1) comprising: a first and a second jaw (2, 3) arranged facing one another and connected to one another so as to go from an open position (O) to a closed position (F), a first treatment surface (2d), borne by the first jaw (2), and a second treatment surface (3d), borne by the second jaw (3), the treatment surfaces (2d, 3d) being intended to grip said keratin fibres, and at least one of the treatment surfaces (2d, 3d) being intended to be heated, at least one of the treatment surfaces (2d, 3d) being partially or totally covered with at least one substrate (6) comprising a surface (6a) coated with at least one layer (6b) containing one or more dyes, preferably chosen from oxidation dyes and/or direct dyes, and/or one or more chemical oxidizing agents.

2. Process according to claim 1, characterized in that the oxidation dyes are chosen from couplers and oxidation bases.

3. Process according to claim 1, characterized in that the direct dyes are chosen from neutral and/or cationic and/or anionic direct dyes.

4. Process according to claim 1, characterized in that the substrate (6) is an element in sheet form.

5. Process according to claim 1, characterized in that the substrate (6) is mounted totally or partially mobile on at least one of the treatment surfaces (2d, 3d) of the hand-held styling device (1).

6. Process according to claim 5, characterized in that the substrate (6) is oblong in shape and covers, on both sides, at least one of the treatment surfaces (2d, 3d) of the hand-held styling device (1).

7. Process according to claim 1, characterized in that the substrate (6) is mounted totally or partially mobile on at least one of the treatment surfaces (2d, 3d) of the hand-held styling device (1) by means of a mechanical attachment system comprising one or more mechanical attachment means.

8. Process according to claim 1, characterized in that the substrate (6) is mounted mobile on at least one of the treatment surfaces (2d, 3d) of the hand-held styling device (1) by means of at least one dispensing means (7), which pivots about a pivoting axis (A), positioned on the first jaw (2) or second jaw (3), in accordance with a vertical axis Y-Y′, and is capable of being driven manually, mechanically, in a motorized manner or following a jaw (2, 3) closure movement.

9. Process according to claim 8, characterized in that the dispensing means (7) is a reel or a barrel.

10. Process according to claim 1, characterized in that the first and/or the second jaw (2, 3) of the hand-held styling device (1) comprises one or more means (14, 15) for detecting the moving into the open position (O) and/or the moving into the closed position of the jaws (2, 3) and connected to a computing device (12) configured for calculating the number of uses of the substrate(s) (6) to the keratin fibres.

11. Process according to claim 1, characterized in that the first and/or the second jaw (2, 3) of the hand-held styling device (1) comprises one or more means (25) for closing the jaws (2, 3).

12. Process according to claim 1, characterized in that the aqueous composition is a composition comprising one or more chemical oxidizing agents, preferably chosen from hydrogen peroxide and/or peroxygenated salts.

13. Process according to claim 1, characterized in that it comprises: using an aqueous composition, as defined on said fibres, applying the treatment surfaces of the hand-held styling device to said keratin fibres, increasing the temperature of said fibres to a temperature ranging from 60 to 250° C.

14. Assembly (11, 24, 26) intended for dyeing and/or lightening keratin fibres, in particular human keratin fibres such as the hair, characterized in that it comprises at least one aqueous composition and at least one hand-held styling device (1) as defined according to claim 1.

15. Assembly (11, 24, 26) according to claim 14, characterized in that it comprises a computing device (12) configured for calculating the number of uses of the substrate(s) (6) on the keratin fibres and a styling device, in which the first and/or the second jaw (2, 3) also comprises one or more means (14, 15) for detecting the moving into the open position (O) and/or the moving into the closed position of the jaws (2, 3); said means (14, 15) being connected to the computing device (12).

16. Assembly according to claim 15, characterized in that the computing device (12) is connected to an image acquisition device configured for visualizing on a screen the surface of the substrate(s) (6) used on the keratin fibres.

17. Assembly according to claim 15, characterized in that the computing device (12) comprises a control member configured for decreasing the heating temperature of the treatment surface (2d, 3d) intended to be heated of the hand-held styling device (1).

18. Assembly according to claim 15, characterized in that the computing device (12) comprises at least one piece of software configured for recording and charging the dyeing or lightening patterns that it is the aim to produce on the keratin fibres.

Description

[0576] Further aims, features and advantages of the invention will become apparent from reading the following description, which is given only by way of non-limiting example and with reference to the appended drawings, in which:

[0577] FIG. 1 diagrammatically represents a longitudinal sectional view of a hand-held styling device according to the invention,

[0578] FIG. 2 diagrammatically represents a longitudinal sectional view of the hand-held styling device of FIG. 1, with substrates according to the invention,

[0579] FIG. 3 diagrammatically represents a longitudinal sectional view of the hand-held styling device of FIG. 1 with a substrate mounted mobile on the first jaw by means of pivoting dispensing means according to a first embodiment,

[0580] FIG. 4 diagrammatically represents a longitudinal sectional view of the hand-held styling device of FIG. 1 with a substrate mounted mobile on the first jaw by means of pivoting dispensing means according to a second embodiment,

[0581] FIG. 5 diagrammatically represents a longitudinal sectional view of an assembly comprising the hand-held styling device of FIG. 1, a computing device and an image acquisition device,

[0582] FIG. 6 diagrammatically represents a longitudinal sectional view of an assembly comprising the hand-held styling device of FIG. 4, a computing device and an image acquisition device,

[0583] FIG. 7 diagrammatically represents a longitudinal sectional view of an assembly comprising the hand-held styling device of FIG. 4, with a means for closing the jaws, a computing device and an image acquisition device,

[0584] FIG. 8 diagrammatically represents a longitudinal sectional view of an assembly comprising the hand-held styling device of FIG. 4, with a means for closing and opening the jaws, a computing device and an image acquisition device.

[0585] Represented diagrammatically in FIG. 1 is a hand-held styling device 1 comprising a first jaw 2 which extends along a longitudinal axis X-X′ and has a parallelepipedal geometric shape.

[0586] The first jaw 2 has an internal surface 2a, an external surface 2b and an edge 2c which can be at a right angle, as represented in FIG. 1, or can be rounded.

[0587] The hand-held styling device 1 also comprises a second jaw 3 which extends along a longitudinal axis X″—X′″ and has a parallelepipedal geometric shape.

[0588] The second jaw 3 also has an internal surface 3a, an external surface 3b and an edge 3c which can be at a right angle, as represented in FIG. 1, or can be rounded.

[0589] The jaws 2 and 3 are arranged opposite one another and are connected to one another by a hinge 4. Thus, the jaws 2 and 3 are articulated so as to go from an open position O, as represented in FIG. 1, to a closed position F which is not represented.

[0590] In FIG. 1, the jaws 2 and 3 have been represented with an identical parallelepipedal geometric shape.

[0591] As a variant, the jaws 2 and 3 can have any geometric shape, for example with a curved shape, or a triangular or polyhexagonal shape.

[0592] As a variant, the jaws 2 and 3 can have different geometric shapes, which are in particular complimentary to one another, to be intolerable.

[0593] The hand-held styling device 1 comprises a first treatment surface 2d borne by the first jaw 2, in particular on the internal surface 2a, and a second treatment surface 3d borne by the second jaw 3, in particular on the internal surface 3a.

[0594] In FIG. 1, the first treatment surface 2d and the second treatment surface 3d are respectively located in the vicinity of the free end of the first jaw 2 and of the second jaw 3, in particular the edges 2c and 3c.

[0595] The treatment surfaces 2d and 3d extend longitudinally over a portion of the length of the first jaw 2 and of the second jaw 3, respectively. In FIG. 1, the two treatment surfaces 2d and 3d are positioned opposite one another.

[0596] The two treatment surfaces 2d and 3d can be brought into contact with the keratin fibres and are suitable for gripping (or pressing) said fibres when they are in the closed position F not represented.

[0597] More specifically, in the open position O, as represented in FIG. 1, the keratin fibres are inserted between the jaws 2 and 3, then in the closed position F, the two treatment surfaces 2d and 3d grip said fibres by exerting a pressure. The pressure is maintained for the treatment time and can be actuated manually or automatically.

[0598] At least one of the treatment surfaces 2d and 3d is suitable for being heated for the purpose of increasing the temperature of the keratin fibres, in particular of the locks of hair, in a temperature range extending from 60 to 250° C., preferably at a temperature extending from 80 to 180° C., preferably extending from 100° C. to 160° C. and better still from 120 to 150° C. The heating of one of the treatment surfaces 2d and 3d can be carried out by means of one or more heating means, not represented in FIG. 1, which can be activated by a control button located on at least one of the jaws 2 and 3.

[0599] Preferably, the two treatment surfaces 2d and 3d are suitable for being heated.

[0600] As a variant, one of the treatment surfaces 2d or 3d is suitable for being heated, the other treatment surface 2d or 3d being suitable for bringing the keratin fibres to the corresponding heating treatment surface 2d or 3d when they are in the closed position F not represented.

[0601] In FIG. 1, a power cord 5 connects the hand-held styling device 1 to an electric power supply which serves in particular to fix a temperature at at least one of the treatment surfaces 2d or 3d.

[0602] In FIG. 1, two substrates, having a general reference 6, comprising a surface 6a coated with at least one layer 6b are represented in the process of being installed at the free ends of the jaws 2 and 3 so as to cover the treatment surfaces 2d and 3d.

[0603] According to FIG. 1, the two substrates 6 are thus mounted around the treatment surface 2d and the treatment surface 3d.

[0604] In accordance with the embodiment represented in FIG. 1, the two substrates 6 are mounted on the hand-held styling device 1 so as to cover on both sides the treatment surface 2a of the first jaw 2 and the treatment surface 3a of the second jaw 3. As a result, the substrates 6 are mounted on the hand-held styling device 1 so as to partially cover, in particular surround, the internal surface 2a and the external surface 2b of the first jaw 2 and also the internal surface 3a and the external surface 3b of the second jaw 3.

[0605] More specifically, according to this embodiment, the two substrates 6 have an oblong, in particular cylindrical, geometric shape, which makes it possible to insert the free end of the first jaw 2 bearing the treatment surface 2d and the free end of the second jaw 3 bearing the treatment surface 3d inside the substrates 6.

[0606] Thus, the substrates 6 can be easily installed on the treatment surfaces 2d and 3d of the hand-held styling device 1 in order to produce a colouring, in particular one or more coloured or bleached patterns, during the use on the keratin fibres.

[0607] The substrates 6 may be identical or different, that is to say may have at their surface 6a layers comprising dyes, preferably oxidation dyes, or oxidizing agents, having different geometric shapes, in particular different patterns.

[0608] As a variant, the substrate 6 may be mounted on the hand-held styling device 1 so as to cover on both sides a single treatment surface 2d or 3d, preferably the treatment surface 2d or 3d intended to be heated for the purpose of increasing the temperature of the keratin fibres.

[0609] As a further variant, the substrate 6 may wrap at least one of the treatment surfaces 2d or 3d like a food film.

[0610] FIG. 2 thus describes the hand-held styling device 1 once the substrates 6 been installed on the treatment surfaces 2d and 3d borne respectively by the jaws 2 and 3.

[0611] More specifically, FIG. 2 diagrammatically represents the substrates 6 mounted on the treatment surfaces 2d and 3d in an adjusted manner in order to cover them over the whole of their length. Thus, the substrates 6 totally cover the treatment surfaces 2d and 3d and partially cover the jaws 2 and 3, leaving free a portion of their internal surfaces 2a (respectively 3a) and external surfaces 2b (respectively 3b).

[0612] Preferably, the treatment surfaces 2a and 3a are in contact with the substrates 6.

[0613] In FIG. 2, the substrates 6 have a closed oblong geometric shape, that is to say they cover not only, on both sides, the treatment surfaces 2d and 3d, but also the free ends of the jaws 2 and 3, in particular the edges 2c and 3c. Preferably, the substrates 6 are elements in sheet form having an oblong shape.

[0614] As a variant, the substrates 6 can cover a portion of the free end of the jaws 2 and 3, that is to say the internal surfaces 2a and 3a and also the external surfaces 2b and 3b, while at the same time leaving free the edges 2c and 3c.

[0615] As a further variant, the substrates 6 can be sheets having a parallelepipedal shape which cover the treatment surfaces 2d and 3d of the hand-held styling device 1 and a portion of the internal surfaces 2a and 3a of the jaws 2 and 3.

[0616] The substrates 6 can be attached on the treatment surfaces 2d and 3d by means of a mechanical or magnetic attachment system, which makes it possible to improve their removable nature and allows them to be rapidly installed and/or removed.

[0617] Preferably, the attachment system can be clips or grippers, not represented in FIG. 2.

[0618] The substrates can be rapidly installed on and/or removed from the hand-held styling device 1 as a function of the type and number of patterns that it is the aim to produce.

[0619] FIG. 3 represents a dispensing means, having a general reference 7, mounted on the external surface 2b of the first jaw 7, comprising two spools 8a and 8b connected to one another by a belt 9, preferably an endless belt, which has an exterior surface 9a. The dispensing means 7 is removably attached to the jaw 2, for example by means of a magnetic system, not represented in FIG. 3.

[0620] More specifically, the spool 8a is positioned on the external surface 2b in the vicinity of the edge 2c of the jaw 2 and the spool 8b is positioned on the external surface 2b in the vicinity of the hinge 4

[0621] The spools 8a and 8b are mounted so as to rotate freely about a pivoting axis A on the first jaw 2, in accordance with a vertical axis Y-Y′, and operate cooperatively with each other by virtue of the presence of the belt 9 allowing their simultaneous clockwise rotation. The rotational movement of the spools 8a and 8b is actuated manually, mechanically, in a motorized manner or following a movement to close the jaws 2 and 3.

[0622] The substrate 6 is mounted on the whole of the dispensing means 7 so as to cover the whole of the first jaw 2, in particular the treatment surface 2d and also the edge 2c. In particular, the substrate 6 is positioned on the spools 8a and 8b and is capable of being driven by the belt 9. During the rotation of the spools 8a and 8b, the substrate 6 moves in a clockwise direction and circulates between the jaws 2 and 3 of the hand-held styling device 1 by virtue of the belt 9. Thus, the dispensing means 7 can correspond to a barrel and makes it possible to circulate the substrate 6 before after each application.

[0623] In accordance with this embodiment, the treatment surface 2d is intended to be heated in order to increase the temperature of the keratin fibres.

[0624] FIG. 4 represents another embodiment of the dispensing means 7 which is mounted on the external surface 2b of the first jaw 2 and comprises two spools 8c and 8d positioned in the same way as in FIG. 3. The two spools 8c and 8d are removably attached to the jaw 2, for example by means of a magnetic system, not represented in FIG. 4.

[0625] The two spools 8c and 8d are connected to one another by means of a belt 10, preferably an endless belt, and are mounted so as to rotate freely about a pivoting axis A on the first jaw 2, said spools being positioned on the external surface 2a in accordance with a vertical axis Y-Y′.

[0626] In accordance with this embodiment, the spool 8d represents a spool for feeding the substrate 6 and the spool 8c represents a spool for receiving the substrate 6. By virtue of the presence of the belt 10, the rotation of the spool 8d drives the rotation of the spool 8c.

[0627] Initially, the substrate 6 is wound only on the spool 8d, which is positioned on the external surface 2a in the vicinity of the hinge 4. During operation, the spool 8d rotates about its axis of rotation A and the substrate 6 moves, driven by the belt 10, towards the school 8c while passing over the internal surface 2a and the treatment surface 2d of the jaw 2. The substrate 6 is thus placed on the treatment surface 2d when the jaws 2 and 3 are in the open position O before inserting the keratin fibres between said jaws 2 and 3.

[0628] The dispensing means 7 can thus correspond to a reel since it makes it possible to circulate the substrate 6 from one spool to another, in the case in point from the spool 8d serving to feed the spool 8c which receives it.

[0629] In accordance with this embodiment, the treatment surface 2d is intended to be heated in order to increase the temperature of the keratin fibres.

[0630] In accordance with FIGS. 3 and 4, the dispensing means 7 thus represented has the advantage of producing several identical or different coloured or bleached patterns while at the same time dispensing with the regular operations of installing and removing the substrate(s).

[0631] The use of such a dispensing means proves to be particularly advantageous for producing varied and/or numerous patterns while at the same time changing substrates as little as possible.

[0632] In accordance with the embodiments of FIGS. 3 and 4, the substrate can advantageously correspond to a ribbon comprising, on one and the same surface, several layers of different geometric shapes capable of producing varied coloured or bleached patterns. Thus, the dispensing means 7 makes it possible to use the various layers of one and the same substrate in the form of a ribbon.

[0633] FIG. 5 diagrammatically represents an assembly, having the general reference 11, comprising the hand-held styling device 1 as described in FIG. 2, that is to say the free ends of the jaws 2 and 3 of which are covered with the substrates 6, a computing device 12 and an image acquisition device 13.

[0634] In FIG. 5, the first jaw 2 further comprises detection means 14 positioned on the internal surface 2a and the second jaw 3 further comprises work detection means 15 positioned on the internal surface 3a.

[0635] The detection means 14 and 15 are capable of detecting the movement of the jaws 2 and 3 into the open position O and into the closed position F. The detection means 14 and 15 are respectively connected to the computing device 12 by means of circuits 16 and 17.

[0636] Thus, the detection means 14 and 15 make it possible to provide information on the number of times that one and the same substrate has been used to produce one or more coloured or bleached patterns and/or the number of times that one and the same substrate can still be used before total extraction of the dyes.

[0637] In accordance with the embodiment described in FIG. 5, the computing device 12 is connected to an image acquisition device 13 by means of a circuit 18 which makes it possible to visualize, on the screen, the type and number of coloured or bleached patterns produced on the keratin fibres.

[0638] In addition, the first jaw 2 can comprise heating control means 19 intended to control the temperature of the treatment surface 2d of the hand-held styling device 1. According to FIG. 5, the heating control means 19 are connected to the computing device 12, in particular to a control member, which is not represented, by means of a circuit 20.

[0639] Thus, after the application of the substrate 6, the control member of the computing device 12 can reduce the temperature of the treatment surface 2d, in particular to a temperature of less than 60° C., in particular less than 30° C., so as to protect the integrity of the dyes and/or of the oxidizing agents against heat and to prolong the lifetime of the substrate 6.

[0640] In particular, it is possible to provide information about a determined target temperature below which the temperature of the treatment surface 2d must be maintained.

[0641] The control member of the computing device 12 also proves to be particularly advantageous when it is a question of producing coloured or bleached patterns on different models in the same period of time using various hand-held styling devices 1. Indeed, after the production of coloured or bleached patterns on a portion of the head of hair of one model, the temperature of the treatment surface 2d of the hand-held styling device 1 can be decreased and the stylist can use another hand-held styling device in order to produce a colouring on another model. In this way, the stylist can then continue to produce the coloured or bleached patterns of the previous model without having to change substrate.

[0642] FIG. 6 diagrammatically represents an assembly, having the general reference 21, comprising the hand-held styling device 1, as described in FIG. 4, that is to say equipped with a dispensing device 7 comprising the spools 8c and 8d, the computing device 12 and the image acquisition device 13.

[0643] In this embodiment, the computing device 12 is directly connected to the dispensing device 7, in particular to the receiving spool 8c, in particular by means of circuits 22 and 23.

[0644] The combined presence of the computing device 12 and of the image acquisition device 13 makes it possible in addition to help the user identify the pattern(s) (or the layers containing the dyes and/or the chemical oxidizing agents) that are in place in order to perform the dyeing or the lightening. Quite naturally, the two devices 12 and 13 also make it possible to calculate the number of uses of coloured or bleached patterns produced and the number that remain to be produced.

[0645] In accordance with this embodiment, the computing device 12 may comprise a motor card making it possible to order the dispensing means 7 to move the substrate 6 in order to place the desired pattern before performing the dyeing or the lightening. The controlling of the dispensing means 7 by the computing device 12 is carried out by means of the circuits 22 and 23.

[0646] FIG. 7 diagrammatically represents an assembly, having the general reference 24, comprising the hand-held styling device 1, as described in FIG. 4, that is to say equipped with a dispensing device 7 comprising the spools 8c and 8d, the computing device 12 and the image acquisition device 13.

[0647] In accordance with FIG. 7, the first jaw 2 comprises one or more closure means 25, preferably a closure sensor, for closing the jaws 2 and 3 and connected to the computing device 12 by means of a circuit 26.

[0648] The closure means 25 can be used before actuating the dispensing means 7, in particular the spool 8d, making it possible to place another substrate or another layer of the same substrate.

[0649] The use of the closure means 25 is controlled by the computing device 12.

[0650] Thus, the assembly described in FIG. 7 is a semi-automatic system since the jaws 2 and 3 can be in the closed position by virtue of the control of the computing device 12.

[0651] FIG. 8 diagrammatically represents an assembly, having the general reference 26, comprising the hand-held styling device 1, as described in FIG. 4, that is to say equipped with a dispensing device 7 comprising the spools 8c and 8d, the computing device 12 and the image acquisition device 13.

[0652] In accordance with FIG. 8, the first jaw 2 and the second jaw 3 comprise a closure means 27 for closing the jaws 2 and 3 and an opening means 28 for opening the jaws 2 and 3. Preferably, the closure means 27 is an electromagnet and the opening means 28 is a return spring. In other words, the closure means 27 ensures the actuation of a closed position of the jaws 2 and 3, whereas the opening means 28 ensures the actuation of a closed position of the jaws 2 and 3.

[0653] The closure means 27 and the opening means 28 are connected to the computing device 12 by means of a circuit 29.

[0654] Thus, the assembly described in FIG. 8 is an automatic system since the jaws 2 and 3 can be in the closed position and open position by virtue of the control of the computing device 12.

[0655] The computing device 12 may comprise a piece of software 30 configured for recording and loading the dyeing or lightening patterns that it is the aim to produce on the keratin fibres, in particular at various places on the head of hair.

[0656] By virtue of this embodiment, the user can record and load, optionally remotely, in the hair salon of their choice, the type of coloured or bleached patterns, in particular their geometric shape or their colour, and also the number of coloured patterns that they wish to produce on a head of hair.

[0657] In accordance with these various embodiments, the substrate(s) used comprise a surface coated with at least one layer containing one or more dyes, preferably chosen from direct dyes and/or oxidation dyes, more preferably oxidation dyes.

[0658] Preferably, the oxidation dyes are chosen from heterocyclic bases and heterocyclic or benzene-based couplers with at least one amine substituent on the aromatic ring.

[0659] Preferably, the oxidation dyes are chosen from couplers and more preferably heterocyclic or benzene-based couplers with at least one amine substituent on the aromatic ring.

[0660] As a variant, the substrate(s) used comprise a surface coated with at least one layer containing one or more oxidizing agents.

EXAMPLE 1: DYEING ON NATURAL HAIR

[0661] A solution A of sodium persulfate at 10 g % in water is prepared (spontaneous pH=3.4±0.2).

[0662] The dyeing composition B is prepared:

TABLE-US-00006 TABLE 6 B (g %) DENATURED ABSOLUTE ETHYL ALCOHOL 8.8 PROPYLENE GLYCOL 6.2 HEXYLENE GLYCOL 3 DIPROPYLENE GLYCOL 3 (C.sub.14/.sub.16) ALKYL 2 HYDROXYETHYLCELLULOSE ASCORBIC ACID 0.25 POWDERED SODIUM METABISULFITE 0.25 PURE MONOETHANOLAMINE 2 4-(3-AMINOPYRAZOLO[1,5-A]PYRIDIN-2-YL)-1,1- 1.83 DIMETHYLPIPERAZIN-1-IUM CHLORIDE HYDROCHLORIDE 1-METHYL-2-HYDROXY-4-BETA- 0.96 HYDROXYETHYL AMINOBENZENE DEIONIZED WATER qs 100

[0663] The pH of composition B is 9.58±0.2.

[0664] A lock of natural hair is then dyed according to the following protocol: [0665] Solution A is applied to a lock of Caucasian hair comprising 90% grey hairs for 10 min (solution/hair bath ratio: 10/1 by weight). [0666] After this leave-on time, the lock is rinsed. [0667] Using a brush, 10 g of composition B are distributed on Kimtech 7505 adsorbent paper from Kimberly-Clark (dimensions: 10 cm×20 cm). [0668] The paper is then placed between the tongs of a straightening iron, regulated at 180° C. [0669] The lock is sandwiched in the paper, then the tongs of the straightening iron are pressed together for 10 seconds. [0670] The lock is rinsed, washed with Ultra doux camomille shampoo [Ultra soft shampoo with chamomile] and dried. [0671] The colorimetric values are measured using a Konica Minolta CM-3600A spectrocolorimeter.

[0672] A strong purple colouration is obtained.

TABLE-US-00007 TABLE 7 L* a* b* Δ.sub.a*.sub.b* Natural Caucasian lock comprising 90% grey 62.28 1.25 17.12 hairs before treatment Natural Caucasian lock comprising 90% grey 32.31 9.33 −9.03 40.58 hairs after treatment

EXAMPLE 2: DYEING ON BLEACHED HAIR

[0673] The following compositions are prepared:

[0674] Dyeing Composition C

TABLE-US-00008 TABLE 8 C (g %) DENATURED ABSOLUTE ETHYL ALCOHOL 8.8 PROPYLENE GLYCOL 6.2 HEXYLENE GLYCOL 3 DIPROPYLENE GLYCOL 3 (C.sub.14/.sub.16) ALKYL HYDROXYETHYLCELLULOSE 2 ASCORBIC ACID 0.25 POWDERED SODIUM METABISULFITE 0.25 PURE MONOETHANOLAMINE 2 2,3-DIAMINO-6,7-DIHYDRO-1H,5H-PYRAZOLO[1,2- 2 A]PYRAZOL-1-ONE DIMETHANESULFONATE 1-BETA-HYDROXYETHYLOXY-2,4-DIAMINOBENZENE 1.43 DICHLORHYDRATE DEIONIZED WATER qs 100

[0675] Bleaching Powder D

TABLE-US-00009 TABLE 9 D POTASSIUM PERSULFATE 32.9 AMMONIUM PERSULFATE 9.8 SODIUM SILICATE HYDRATE 33.7 MAGNESIUM CARBONATE PENTAHYDRATE 9.2 ETHYLENEDIAMINETETRACETIC ACID DIHYDRATE, 1 DISODIUM SALT ACRYLIC ACID/STEARYL METHACRYLATE COPOLYMER 0.7 POLYMERIZED IN AN ETHYL ACETATE/CYCLOHEXANE MIXTURE HYDROXYETHYLCELLULOSE (MW: 1 000 000) 0.7 L-GLYCINE 1 TALC 6.85 ULTRAMARINE BLUE (CI: 77007) 0.25 POLYDIMETHYLSILOXANE (VISCOSITY: 5 CST) 1.4 WHITE MINERAL OIL 2.5

[0676] Oxidizing Composition E

TABLE-US-00010 TABLE 10 E CETYLSTEARYL ALCOHOL/OXYETHYLENATED 2.85 CETYLSTEARYL ALCOHOL (30 OE) MIXTURE (50% LINEAR 70/30 C13/C15) ALKYL ETHER 0.85 CARBOXYLIC ACID MONOETHANOLAMIDE (2 OE) GLYCEROL 0.5 TETRASODIUM PYROPHOSPHATE DECAHYDRATE 0.04 SODIUM SALICYLATE 0.035 ETIDRONIC ACID, TETRASODIUM SALT, AS AN 0.2 AQUEOUS 30% SOLUTION HYDROGEN PEROXYDE AS A 50% SOLUTION (200 23.5 VOL. AQUEOUS HYDROGEN PEROXIDE SOLUTION) MICROBIOLOGICALLY CLEAN DEIONIZED WATER qs 100

[0677] The pH of composition C is 9±0.2.

[0678] A lock of natural hair is then dyed according to the following protocol: [0679] A bleaching product is prepared by mixing 1 part by weight of bleaching powder D with 2 parts by weight of an oxidizing composition E. [0680] The mixture is applied to a lock of TD8 chestnut-brown Caucasian hair for 50 min (solution/hair bath ratio: 10/1 by weight). [0681] After this leave-on time, the lock is rinsed. [0682] Using a brush, 10 g of composition C are distributed on Kimtech 7505 adsorbent paper from Kimberly-Clark (dimensions: 10 cm×20 cm). [0683] The paper is then placed between the tongs of a straightening iron, regulated at 180° C. [0684] The lock is sandwiched in the paper, then the tongs of the straightening iron are pressed together for 10 seconds. [0685] The lock is rinsed, washed with Ultra doux camomille shampoo [Ultra soft shampoo with chamomile] and dried.

[0686] The colorimetric values are measured using a Konica Minolta CM-3600A spectrocolorimeter.

[0687] A strong red colouration is obtained.

TABLE-US-00011 TABLE 11 L* a* b* Δ.sub.a*.sub.b* Bleached TD8 Caucasian lock before 43.05 8.28 21.09 treatment Bleached TD8 Caucasian lock after 44.1 31.74 24.32 23.7 treatment

EXAMPLE 3: LIGHTENING OF A NATURAL HAIR

[0688] A bleaching solution is prepared: 10 g of bleaching powder D are diluted in water (spontaneous pH=11).

[0689] A lock of natural TD4 Caucasian hair is then lightened according to the following protocol: [0690] The bleaching solution is applied to the lock of hair for 10 min (solution/hair bath ratio: 10/1 by weight). [0691] After this leave-on time, the lock is rinsed. [0692] Using a brush, 10 g of oxidizing composition E are distributed on Kimtech 7505 adsorbent paper from Kimberly-Clark (dimensions: 10 cm×20 cm). [0693] The paper is then placed between the tongs of a straightening iron, regulated at 180° C. [0694] The lock is sandwiched in the paper, then the tongs of the straightening iron are pressed together 5 times (time of each passage: 10 seconds). [0695] The lock is rinsed, washed with Ultra doux camomille shampoo [Ultra soft shampoo with chamomile] and dried.

[0696] The colorimetric values are measured using a Konica Minolta CM-3600A spectrocolorimeter.

[0697] A lightening is obtained.

TABLE-US-00012 TABLE 12 L* a* b* Δ.sub.a*.sub.b* TD4 Caucasian lock before treatment 21.85 3.31 4.35 TD4 Caucasian lock after treatment 24.33 5.46 7.38 6.5