Method for producing a shading on the hair

Abstract

Method for producing a shading on the hair, comprising the stage consisting in: subjecting an amount of a composition (100) capable of exhibiting a variation in its hair dyeing or bleaching power under the effect of a chemical and/or energy stimulus to the said stimulus, so as to obtain at least two fractions (1000; 2000) of the said amount each having a hair dyeing or bleaching power distinct from that of the other fraction, the composition (100) being subjected to the stimulus before or after it is brought into contact with the hair and the composition producing, after exposure to the said stimulus and being brought into contact with the hair, a shaded dyeing or bleaching.

Claims

1. Method for producing a shading on the hair, comprising: subjecting, to a luminous stimulus, an amount of a dyeing composition capable of exhibiting a variation in its hair dyeing power or hair bleaching power under the effect of the luminous stimulus, the subjection causing at least two fractions of the dyeing composition to respectively have a hair dyeing power or hair bleaching power distinct from the other fraction, wherein the dyeing composition is subjected to the luminous stimulus before being brought into contact with the hair, wherein the dyeing composition, after subjection to the luminous stimulus and being brought into contact with the hair, produces a shaded dyeing or bleaching on the hair, and wherein the luminous stimulus is UV radiation.

2. Method according to claim 1, the at least two fractions being produced by subjecting the dyeing composition to a non-zero temperature gradient.

3. Method according to claim 1, the at least two fractions being produced by subjecting the dyeing composition to radiation exhibiting a non-zero energy gradient.

4. Method according to claim 1, the luminous stimulus being applied by a device for application of the luminous stimulus, wherein the device comprises a luminous irradiator containing the dyeing composition.

5. Method according to claim 4, wherein the device for application of the luminous stimulus provides for the dispensing of the dyeing composition on the hair.

6. Method according to claim 5, the device for application of the luminous stimulus being moved in relation to a deposit of dyeing composition during the application of the stimulus.

7. Method according to claim 1, wherein the dyeing composition is present on an subjection element during application of the luminous stimulus to the dyeing composition.

8. Method according to claim 1, wherein the shaded dyeing or bleaching on the hair obtained comprises a first region and a second region exhibiting between them a colour difference in the CIELab space of greater than or equal to 1.

9. Method according to claim 5, the device for application of the luminous stimulus comprising a system for guiding the hair, the method comprising the successive stages of: introducing a first lock of hair into the guiding system of the device for application of the luminous stimulus, carrying out a shaded dyeing or bleaching on the first lock of hair by employing a method according to claim 5, optionally applying, over all or part of the shaded dyeing or bleaching carried out on the first lock of hair, a protective means which makes it possible to mechanically protect the shaded dyeing or bleaching, then disengaging the first lock of hair from the guiding system and introducing therein a second lock of hair, carrying out a shaded dyeing or bleaching on the second lock of hair by employing a method according to claim 5.

10. Method according to claim 5, further comprising a stage of determination of the positioning of the device for application of the luminous stimulus in relation to a substrate on which the dyeing composition is applied or may be applied.

11. Method according to claim 10, the substrate being chosen from the hair or the application element.

12. Method according to claim 5, the device subjecting the hair to the luminous stimulus prior to the dispensing thereof or during the dispensing thereof.

13. Method according to claim 6, the deposit of dyeing composition being present in contact with the hair.

14. Method according to claim 7, the application element being in the form of a sheet element.

Description

DESCRIPTION OF THE FIGURES

(1) The invention can be better understood on reading the detailed description which will follow of non-limiting implementational examples thereof and on examining the appended drawings, in which:

(2) FIG. 1 diagrammatically represents the achievement of a dyeing known from the state of the art,

(3) FIG. 2 diagrammatically represents the achievement of a shaded dyeing according to the invention,

(4) FIGS. 3A and 3B diagrammatically illustrate the variation in colorimetric characteristics within shadings according to the invention,

(5) FIGS. 4A and 4B diagrammatically illustrate the variation in the stimuli applied in order to obtain the shadings according to the invention,

(6) FIGS. 5A and 5B diagrammatically represent various types of shaded colourings obtained by implementing a method according to the invention,

(7) FIG. 6 diagrammatically and partially represents the use of a device for application of the stimulus according to the invention,

(8) FIGS. 7 to 10 represent diagrammatic and partial transverse cross sections of alternative forms of devices for application of the stimulus in accordance with the invention,

(9) FIGS. 11, 12 and 12a diagrammatically and partially represent alternative forms of devices for application of the stimulus,

(10) FIGS. 13 to 29 diagrammatically and partially represent other implementational examples of methods for producing shaded dyeing or bleaching according to the invention,

(11) FIG. 30 represents an applicator which makes it possible to simultaneously treat a plurality of locks, and

(12) FIG. 31 represents a cross section along XXXI-XXXI of the device of FIG. 30.

(13) FIG. 1 diagrammatically illustrates the production, on a head of hair C, of locks 700 having a uniform colour by the implementation of methods known from the state of the art. Such locks 700 may, as explained below, exhibit a rather unnatural appearance at the roots 702.

(14) FIG. 2 diagrammatically illustrates the production, on the head of hair C, of shaded locks 701, for example where the hue varies along the said locks 701. Such locks 701 are obtained by the implementation of methods according to the invention.

(15) FIGS. 5A and 5B respectively illustrate colour shadings adapted to the length of the locks 701 and shadings which are identical whatever the length of the locks 701. The shadings obtained in FIG. 5A correspond to within about one homothetic transformation.

(16) FIGS. 3A and 3B illustrate the variation in colorimetric characteristics along a lock carrying a shading according to the invention.

(17) As illustrated, this variation can be linear according to the position along the lock (solid-line curves) or non-linear, in particular asymptotic (broken-line curves).

(18) It is possible to obtain, along a lock treated by a method according to the invention, a linear or asymptotic variation in L (lightness) on moving along the lock from the root towards the end of the hairs.

(19) It is also possible to obtain, along a lock treated by a method according to the invention, an in particular linear or asymptotic variation in C* (saturation) on moving along the lock from the root towards the end of the hairs.

(20) It is furthermore possible to obtain, along a lock treated by a method according to the invention, an in particular linear or asymptotic variation in a (position on the red/green axis), on moving along the lock from the root towards the end of the hairs, or in b (position on the blue/yellow axis) or in h (hue).

(21) One or more of the colorimetric characteristics chosen from L, C*, h, a and b can vary on moving along the treated lock of hair.

(22) It is possible to obtain a dyeing, along a lock, which varies in tones, the hairs gaining, for example, at least one bleaching tone.

(23) In the case where it is desired to treat half or more of the hairs, the shading can advantageously follow a sigmoid variation (dashed-line curve in FIG. 3B).

(24) The variation in the colorimetric characteristic of such a shading is concentrated in the mid-zone of the length of the hairs and can make it possible to avoid the effects of roots and ends.

(25) It is possible, for example, to obtain a colour at the roots which is relatively close to the colour visible at the roots before the method according to the invention is implemented. In particular, it is possible to obtain a colour at the roots which is nuanced, in particular lightened, by 2 tones with respect to the colour visible at the roots before the method according to the invention is implemented.

(26) It is possible, for example, to obtain a colour at the ends which is significantly different from the colour visible at the ends before the method according to the invention is implemented. In particular, it is possible to obtain a colour at the ends which is nuanced, in particular lightened, by 4 tones or more with respect to the colour visible at the ends before the method according to the invention is implemented.

(27) FIGS. 4A and 4B represent examples of change in the stimuli applied along the lock of hair in the context of methods according to the invention.

(28) It is possible, for example, to have a linear or asymptotic variation in the temperature to which the hair composition is subjected according to the position along the lock.

(29) In an alternative form, it is possible to deposit an amount of developer or inhibitor which varies in a linear or asymptotic manner according to the position along the lock.

(30) The application of such gradients can allow shaded hair dyeing or bleaching powers to be obtained, as described in detail subsequently.

(31) In FIG. 6, a composition (not represented) capable of exhibiting a variation in its hair dyeing or bleaching power under the effect of a thermal stimulus has been brought into contact with a lock of hair to be treated M.

(32) The device for application of the stimulus is in the form of a handpiece 3 designed in order to receive the lock M of hair to be treated and in order to subject, in a treatment space, the composition to a stimulus, for example a thermal stimulus.

(33) The handpiece 3 can comprise, as illustrated, a handle 6 and a push button which makes it possible to trigger the emission of the stimulus.

(34) The stimulus, when it is thermal, can be generated, for example, by a series of infrared electroluminescent diodes (not represented).

(35) In the embodiment illustrated in FIG. 6, the stimulus is applied in a non-uniform manner when the handpiece 3 is moved along the lock to be treated M. For example, the power emitted by the electroluminescent diodes increases when the handpiece 3 is moved along the lock to be treated M. The variation can be controlled by the user or can be carried out automatically.

(36) In this case, the position of the handpiece 3 in relation to the treated lock M can be determined by a device (not represented) for the determination of the positioning of the handpiece 3, for example an accelerometer.

(37) The handpiece 3 can exhibit various configurations which make it possible to subject the composition to the stimulus.

(38) The handpiece 3 can comprise any means for receiving and guiding the hair, for example, as is seen in FIG. 6, a channel 10 formed between an upper branch 12 and a lower branch 13 defining the treatment space. The branches 12 and 13 can be fixed in relation to one another or, in an alternative form, be designed so as to part in the manner of a clip, for example, in order to facilitate the insertion between them of the hair to be treated. The closure of the branches can be detected in order to prevent the emission of the stimulus in the case of a defect in closure of the branches.

(39) An alternative form of handpiece 3 comprising a channel for receiving the hair to be treated, formed on a single branch, has been represented diagrammatically in FIG. 11.

(40) The handpiece can in particular comprise one or more teeth 24 or other protrusions placed before and/or after the treatment space, as has been illustrated diagrammatically in FIG. 8.

(41) The handpiece 3 can comprise means which make it possible to determine the rate of movement of the lock M exposed to the stimulus in relation to the said handpiece. These means can comprise at least one rotary member which rotates under the effect of the movement of the lock M in the treatment space in order to allow the treatment device to automatically calculate, according to this rate of movement, the modification of the stimulus to be applied to the composition.

(42) By way of example, a treatment head comprising two opposing rollers 30, which can rotate on contact with the lock M introduced between them, has been represented in FIG. 9.

(43) The rotation of the rollers 30 is measured and the treatment device can comprise calculation means suitable for acting on the emission of the stimulus, for example heat, according to this rotation.

(44) The treatment device can be designed so as to be able to deposit the composition during the movement of the lock M.

(45) The handpiece 3 can, to this end, comprise an application member 50 comprising, for example, an applicator pad which makes it possible to deposit the composition on the lock M, as illustrated in FIG. 10. This applicator pad is carried by a support which does not interfere with the passage of the lock M between the branches 12 and 13.

(46) The variation in hair dyeing or bleaching power of the composition can be obtained by subjecting to radiation.

(47) For example, the composition can be a photochromic composition which can develop under the effect of radiation having a given wavelength and the shading can be obtained by application of light radiation having an energy spectral density in the vicinity of this wavelength which increases on moving along the lock M.

(48) The device for application of the stimulus can also be produced without a handpiece, for example being provided in the form of a cubicle or of a hood in which the user is placed, the submission to the stimulus being carried out at a distance, it being possible for the hair, if appropriate, to have been prepared beforehand for the treatment, for example placed on an appropriate support.

(49) Screen-forming means can be positioned on either side of the treatment space in order to counteract escapes of light, for example a flexible seal, a row of hairs or a baffle.

(50) An example of a manual-control device 170, which makes it possible to prepare and dispense a developer, in particular an oxidizing agent, in order to create a deposit of developer having, along the said deposit, a shaded power of developing the composition, has been represented in FIG. 12.

(51) The body 160 defines two reservoirs and the user can apply pressure thereto in order to dispense the contents thereof. A dispensing head 161 provides for the mixing of the contents of the reservoirs in variable proportions. The reservoirs open, for example, through supply orifices 162 and 163 facing an adjusting part comprising two outlet orifices 164 and 165 which can be superimposed more or less on the supply orifices according to the position of this part with respect to the body 160. Thus, for the three relative positions illustrated in FIG. 12A, the components are dispensed respectively in the proportions (expressed in %) of 100/0, 50/50 and 0/100. The part which acts on the flow rate of each of the components may be able to rotate about the longitudinal axis of the device and may, if appropriate, be moved automatically by an elastic return member which cannot be seen and which can be stressed initially by the user by virtue of an operating lever 168. In an alternative form, the operating lever 168 controls the position of the adjusting member and is actuated by the user during the dispensing in order to vary the formulation of the mixture.

(52) In the presence of an elastic return member, a brake, for example of viscoelastic fluid type, can be rotated with the part for adjusting the flow rate so that the movement of the adjusting part under the action of the elastic return member does not occur too quickly.

(53) In order to use the system illustrated in FIGS. 12 and 12A, the user actuates the operating lever 168 in order to stress the elastic return member and then releases the operating lever. The adjusting part then moves automatically under the action of the return member for a predefined period of time, during which the user applies pressure to the reservoirs in order to force the products to pass through the dispensing head. In an alternative form, in the absence of an elastic return member, the user moves the operating lever 168 in order to change the formulation.

(54) The formulation of the composition which is dispensed varies, which formulation results from the mixing of the components in a nozzle 169 provided with a mixer, for example having helices having opposite pitches. The user moves the nozzle in relation to the support on which the developer is deposited. He thus obtains a deposit of developer, the power of which to develop the composition varies longitudinally.

(55) A method for producing a shading on a lock M by bringing the hair into contact with a composition 100 capable of exhibiting a variation in its power to dye hair by being brought into contact with an oxidizing agent 110 has been illustrated in FIGS. 13 to 15.

(56) As represented in FIG. 13, a non-uniform amount of composition 100 has been applied to the lock M, the amount of composition 100 deposited increasing, for example linearly, on moving from the root 120 towards the end 121 of the hairs.

(57) In a second stage, the oxidizing agent 110 is brought into contact with the deposit of composition 100. During this stage, which is illustrated in FIG. 14, the amount of oxidizing agent 110 applied is constant along the treated lock M.

(58) It would be possible to deposit an amount of oxidizing agent 110 which can vary along the lock M. It might also be possible to deposit an amount of composition 100 which is constant along the lock M and an amount of oxidizing agent 110 which can vary along the lock M.

(59) The variable amounts of oxidizing agent 110 or of composition 100 can be deposited along the lock M by transfer from an applicator element or by spraying, the outlet flow rate being modified according to the position along the lock. The variable amount can also be applied by an applicator roller which uses up composition to be applied as it moves along the lock M.

(60) In an alternative form, it is possible to apply a constant amount of composition 100 and a constant amount of oxidizing agent 110 and to vary the exposure time according to the position on the lock M in order to obtain a shaded dyeing or bleaching.

(61) In an alternative form, it is possible to first apply the oxidizing agent 110 to the lock M and to subsequently apply the composition 100. Of course, the embodiments described above apply mutatis mutandis to this alternative form.

(62) FIG. 15 illustrates the production of a shaded dyeing by this method, comprising at least two fractions 1000 and 2000 of composition, each having a different hair dyeing power.

(63) A method for sensitizing shaded hair has been represented in FIGS. 25 to 27. In a first step, as illustrated in FIG. 25, a sensitizing composition 600 is applied to a lock of hair. As illustrated in FIG. 25, the amount of composition 600 deposited varies along the lock M so that the degree of sensitization of the surface 601 of the hair varies along this same direction, as illustrated in FIG. 26. The composition 100 is subsequently applied, as illustrated in FIG. 27, to the sensitized surface 601 in order to obtain the shaded dyeing or bleaching.

(64) FIGS. 16 and 17 illustrate an application element 200 according to the invention. This application element is, for example, a sheet element.

(65) The application element comprises a transfer surface 201 on which a deposit of composition 100 is present. The deposit of composition 100 extends along a longitudinal axis Y.

(66) Furthermore, the application element 200 comprises heating means (not represented) which make it possible to obtain, at the transfer surface 201, a non-zero temperature gradient along at least one direction.

(67) FIG. 17 represents the state of the deposit of composition 100 after application of the temperature gradient at the transfer surface 201, this temperature gradient making it possible to obtain a first fraction 1000 and a second fraction 2000 of the composition, each exhibiting a different hair dyeing or bleaching power. Preferably, the dyeing and bleaching power varies monotonally along the axis Y.

(68) The composition thus subjected to the temperature gradient can subsequently be applied by transfer to a lock of hair M.

(69) In an alternative form, illustrated in FIGS. 23 and 24, the first fraction 1000 and the second fraction 2000 are obtained by application of a non-zero temperature gradient by an external heating member 500.

(70) In the configuration of FIG. 23, the heating member 500 subjects the composition 100 to a first temperature. The heating member 500 is subsequently moved with respect to the deposit of composition 100 in order to be brought into the position illustrated in FIG. 24, in which it subjects the composition 100 to a second temperature different from the first. In an alternative form, the time of exposure to the heating member, brought to a constant temperature, varies but the duration of positioning at a given location varies, so as to locally heat the composition to a greater or lesser degree, taking into account its thermal inertia.

(71) FIGS. 18 and 19 represent an alternative form in which the device 300 for application of the stimulus comprises, within a reservoir delimited by a wall 301, a composition 100 intended to be applied to the hair M.

(72) The device for application of the stimulus comprises an applicator end piece 302 through which the composition 100 is intended to be dispensed onto the lock of hair M.

(73) In the example illustrated in FIG. 18, a heating member 303 is present at the applicator end piece 302.

(74) When the composition 100 is present in the applicator end piece 302, the composition is brought to a first temperature which makes it possible to obtain a first fraction 1000, as represented in FIG. 18. The first fraction is subsequently dispensed on the lock M.

(75) The device 300 for application of the stimulus is subsequently moved in relation to the lock M and can repeat various dispensing operations, the heating member 303 being brought each time to a different temperature.

(76) After several dispensing operations, a deposit is obtained on the lock M which has a hair dyeing power which varies on moving along the lock M. The variation in the temperature preferably takes place continuously.

(77) It is possible, in this implementational example, to replace the heating member 303 with a device which dispenses an oxidizing agent in controlled amounts, the composition 100 exhibiting, in this case, a variation in its dyeing power by being brought into contact with an oxidizing agent.

(78) An application element 200 in the form of a sheet element which can be folded back along its axis X has been represented in FIG. 20.

(79) The application element 200 comprises, in a first zone 401, a deposit of composition 100 and, in a second zone 402, a deposit of an oxidizing agent 110.

(80) The amounts of composition 100 and of oxidizing agent 110 can vary or be constant according to the position on the first and second zones 401 and 402 along the longitudinal axis X of the application element 200.

(81) The stage of folding the application element 200 about its axis X, which results in the composition 100 being brought into contact with the oxidizing agent 110, has been represented in FIG. 21. The result of this contacting operation is illustrated in FIG. 22. At least one first fraction 1000 and one second fraction 2000 having different hair colouring powers are obtained.

(82) FIG. 30 represents an applicator 800 which makes possible the simultaneous treatment of several locks M of hair. The applicator comprises a support 801, which can in particular constitute a grasping part, connected to a comb 810 comprising a core 811 to which is connected a plurality of teeth 812.

(83) Two consecutive teeth 812 define between them a treatment zone 820 into which all or part of a lock M of hair is intended to be placed in order to receive the hair composition.

(84) The applicator 800 can comprise between 10 and 50 treatment zones 820, in particular between 20 and 40 treatment zones 820.

(85) The arithmetic mean of the spacings e between two consecutive teeth 812 can be between 0.3 cm and 2 cm, preferably between 0.4 cm and 1.5 cm. The spacing e between two consecutive teeth 812 corresponds, as illustrated in FIG. 30, to the length of the segment connecting the distal ends 813 of the said teeth 812.

(86) The applicator 800 can be configured in order to make it possible to obtain a shaded dyeing over a plurality of locks of hair.

(87) The applicator can comprise, as illustrated in FIG. 31, at the treatment spaces 820, orifices 830 for dispensing the hair composition.

(88) The applicator 800 can additionally comprise a plurality of reservoirs (not represented) in which hair compositions having distinct hair colouring powers are present. The applicator 800 can comprise a mixing device (not represented) which makes it possible to mix, in predefined proportions, two hair compositions originating from two different reservoirs. The applicator 800 can additionally be configured in order to apply an energy and/or chemical stimulus as described above.

EXAMPLES

(89) Example of Application of Thermal Stimulus In Situ

(90) Use is made of a U-shaped tube 1100 with a length of 20 cm and a width of 2 cm, with edges 1101 6 mm in height, as illustrated in FIG. 28.

(91) A solution of PolyNIPAM (poly(N-isopropylacrylamide)) combining two oxidation dye precursors (para-phenylenediamine and resorcinol) is prepared.

(92) The solution is placed at the bottom of the tube and it is left to give a thick gel with a height of approximately 2 mm.

(93) Subsequently, a long lock of grey hair is placed in the tube, in contact with the gel. A 30V oxidant cream is then applied in order to compress the lock in the tube.

(94) A heating device is then positioned, which will impose, on the lower face of the tube, a temperature varying from one end to the other of the length. It varies from 30 C. to 42 C. from one end to the other. After 5 min, the heating device is removed. The lock is left to stand for 30 min. At the end of the treatment, the lock of hair is extricated. The appearance of a shaded dyeing is seen.

(95) In an alternative form, as illustrated in FIG. 28a, a plastic film 1102 can be issued when the desired appearance has been achieved. In this case, the edges 1101 of the tube 1100 can comprise an adhesive deposit which makes it possible to attach the film 1102.

(96) Example of Application of Thermal Stimulus to an Application Element

(97) The same device as in the preceding example is placed, without lock or oxidizing agent, on the heating device. After 5 min, 30V oxidant cream is placed at the bottom of the tube. The lock is then positioned by pushing it into the cream. The lock is left to stand for 30 min. At the end of the treatment, the lock of hair is extricated. The appearance of a shaded dyeing is seen.

(98) Example of Application of a Luminous Stimulus

(99) An ethanolic solution comprising para-phenylenediamine (1%), resorcinol and, for 40% by weight, a composition comprising 10% of p-phenylenediacrylic acid polyester photosensitive polymer (Eastman Kodak) in acetone is placed in a tube as described in the above example.

(100) Its structure corresponds to the following sequence:

(101) ##STR00001##

(102) Then, without waiting, the tube is illuminated with an increasing amount of UV-A radiation (360 nm). They UV-A intensity varies from 0 to 5 J per cm.sup.2.

(103) Then, without waiting, a white lock is positioned and a creamy composition formed of aqueous hydrogen peroxide solution is positioned. This composition coats the lock and presses it against the bottom of the tube.

(104) After 30 min, the lock is extricated and washed.

(105) A shading in colour is observed over the lock.

(106) Example of Application of a Chemical Stimulus

(107) In this example, use is made of a spray comprising 2% potassium iodide in water.

(108) An ethanol/water (50/50) solution comprising dihydroxyindole and aqueous hydrogen peroxide solution at pH 4 is prepared. A lock of grey hair is impregnated with the abovementioned composition (2 g of solution per 2 g of hair).

(109) The lock is sprayed from a position 40 cm from the lock. During the spraying, a sheet 1600 formed of board with a hole in it, the hole consisting of a square window of 2 cm by 2 cm, is moved as illustrated in FIG. 29, in order for the sprayed droplets to pass through the window.

(110) The window is moved increasingly rapidly so that one edge of the lock receives, per cm, only 10 mg of sprayed composition, whereas the edge forming the other end receives, per cm, 100 mg of sprayed composition.

(111) At the end of the spraying, the lock is tapped in order for the sprayed liquid to impregnate the lock.

(112) The lock is left to stand for 30 min. At the end of the treatment, the lock of hair is extricated. The appearance of a shaded dyeing is seen.

(113) In an alternative form, first the spraying is carried out (with the moving window), then rinsing is carried out and then the colouring solution is applied.

(114) Alternative embodiments, which are not illustrated, of the invention can combine characteristics originating from the various implementational examples which have just been described.

(115) The expression comprising a should be understood to be synonymous with comprising at least one.

(116) The term between should be understood as including the limits.