Method for bleaching keratin fibers using oxidizing agent compositions and UV-visible radiation - Patents.com

Abstract

The present invention relates to a method for bleaching keratinous fibers, in particular human keratinous fibers such as hair, comprising the steps of applying to said fibers an oxidizing agent composition comprising hydrogen peroxide and a non-peroxide ammonium salt having a molar mass greater than 40 g / mol, and, after applying said oxidizing agent composition, applying to said fibers an oxidizing agent composition having a wavelength in the range of 200-800 nm and a fluence of 1-5000 J / cm. 2 and exposing the substrate to UV-visible radiation in the range of 0.1 to 0.25.

Description

[Technical field]

[0001] The present invention relates to a method for bleaching keratinous fibers, in particular human keratinous fibers such as hair, comprising the steps of applying to said fibers an oxidizing composition, followed by applying to said fibers an oxidizing agent having a wavelength in the range of 200-800 nm and a fluence of 1-5000 J / cm 2 and exposing the substrate to UV-visible radiation in the range of 0.1 to 0.5 μm.

[0002] The present invention relates to the technical field of hair bleaching. [Background technology]

[0003] Bleaching or lightening of keratinous fibres, particularly human keratinous fibres such as hair, is carried out by oxidising the "melanin" pigment, thereby decomposing and partially or completely removing said pigment.

[0004] Generally, the methods for lightening or bleaching human keratin fibres consist of applying, most often under alkaline pH conditions, an aqueous composition containing at least one oxidizing agent, the role of which is in particular to decompose the melanin of the keratin fibres, resulting in a lightening of the fibres (to a greater or lesser extent depending on the nature of the oxidizing agent present). For relatively gentle lightening, therefore, hydrogen peroxide is generally used as the oxidizing agent. If a more intense lightening is desired, in the presence of hydrogen peroxide, a peroxide salt, for example a persulfate, is usually used.

[0005] The lightening methods described in the prior art usually have the drawback of including steps that are known to take a significant amount of time to carry out. For example, lightening methods may include a step of leaving an oxidizing composition for up to 50 minutes, which usually entails the additional time required for the application of said composition. In other words, the application and leaving of the compositions used in such lightening methods are known to take a significant amount of time, which may make their use cumbersome for the recipient and / or hair stylist.

[0006] Such lightening methods also have the disadvantage that they use compositions containing relatively high concentrations of active substances such as alkaline and / or oxidizing agents, which can make such methods expensive.

[0007] Furthermore, standard lightening methods have the disadvantage that they alter the natural color of the keratin fibers as they bleach them, usually resulting in an unattractive orange-ish appearance to the base color.Therefore, there is a need to develop a method for lightening keratin fibers that retains more of their natural color.

[0008] Furthermore, decolorization methods using light sources are already known from the prior art.

[0009] Indeed, US Pat. No. 5,399,633 describes a bleaching method that includes an irradiation step using a laser or a flash lamp.

[0010] In this regard, Patent Document 2 describes a photochemical decolorization method that uses a composition containing 0.5% to 5% by mass of a photosensitizer and a composition capable of releasing hydrogen radicals.

[0011] Patent Document 3 describes a dyeing or decolorizing method using a step of irradiation with UV radiation having a wavelength in the range of 200 to 600 nm or with a specific irradiation device.

[0012] These documents do not describe an effective bleaching method using irradiation with UV-visible radiation having a specific range of fluences.

[0013] Patent Document 4 describes a method for bleaching or dyeing using a composition containing a chemical oxidizing agent and a step of irradiating with UV-visible radiation with improved effectiveness.

[0014] Nevertheless, there is a need to further improve existing decolorization methods. [Prior art documents] [Patent documents]

[0015] [Patent Document 1] U.S. Pat. No. 4,792,341 [Patent Document 2] International Publication No. 91 / 06279 Brochure [Patent Document 3] International Publication No. 2007 / 048473 Brochure [Patent Document 4] International Publication No. 2015 / 165949 Brochure Summary of the Invention [Problem to be solved by the invention]

[0016] There is therefore a real need to develop a method for bleaching keratinous fibers, in particular human keratinous fibers such as hair, that does not have the drawbacks mentioned above, i.e. that can be carried out in a shorter time and does not damage the natural color and the integrity of the keratinous fibers. [Means for solving the problem]

[0017] This object is achieved by the present invention, the subject of which is in particular a method for bleaching keratinous fibres, in particular human keratinous fibres such as hair, comprising: i) adding to said fibers - at least one non-peroxygenated ammonium salt with a molar mass greater than 40 g / mol; - with hydrogen peroxide; - optionally at least one alkaline agent different from the non-peroxide ammonium salts having a molar mass greater than 40 g / mol; the pH of the oxidizer composition is 7.5 or greater; ii) applying a ray of light having a wavelength in the range of 200 to 800 nm and a fluence of 1 to 5000 J / cm to the fiber; 2and exposing the composition to UV-visible radiation in the range of 0.1 to 0.5 nm after application.

[0018] In other words, the method according to the invention is successful by applying a composition comprising one or more non-peroxide ammonium salts with a molar mass greater than 40 g / mol, hydrogen peroxide and, optionally, an alkaline agent different from the non-peroxide ammonium salts with a molar mass greater than 40 g / mol, the composition having a pH of at least 7.5, and irradiating the fibers as described above.

[0019] The irradiation step of the bleaching method according to the invention advantageously makes it possible to shorten or even eliminate the time for leaving the oxidizing composition on the keratin fibers necessary to effectively lighten them, the total treatment time then being the time corresponding to the application of the oxidizing composition to the keratin fibers and the irradiation of the fibers.

[0020] As a result, the method according to the invention makes it possible to reduce the treatment time of the keratin fibres and is easier to carry out.

[0021] Advantageously, the irradiation step is carried out using a light emitting source which increases the efficiency of the method according to the invention.

[0022] Moreover, the method according to the invention makes it possible to improve the lightening effect while preserving the natural color of the keratin fibers less than the lightening methods of the prior art. In fact, it is to be noted that the keratin fibers treated with the lightening method according to the invention do not have an orange-tinged lightened background color, as do the fibers treated with the lightening methods of the prior art.

[0023] In other words, the lightening method of the present invention makes it possible to obtain more natural and beautiful colors. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Other characteristics and advantages of the invention will become more apparent on reading the following description and examples.

[0025] In the following document, unless otherwise stated, the limits of a range are included within the range.

[0026] The phrase "at least one" is equivalent to the phrase "one or more."

[0027] The human keratinous fibres treated by the method according to the invention are preferably hair.

[0028] As indicated above, the bleaching method according to the invention comprises a step i) of applying an oxidizing agent composition to the keratin fibres.

[0029] Oxidizing Agent Composition The oxidizer composition includes hydrogen peroxide.

[0030] Hydrogen peroxide may be present in the oxidizer composition in a total content ranging from 0.5% by mass to 12% by mass, preferably from 1% by mass to 10% by mass, and more preferably from 3% by mass to 9% by mass, based on the total mass of the oxidizer composition.

[0031] The oxidizer composition further comprises at least one non-peroxide ammonium salt having a molar mass greater than 40 g / mol.

[0032] The term "ammonium salt" refers to any inorganic or organic compound that contains within its structure at least one ammonium-based cation and an anion derived from an inorganic or organic acid.

[0033] The term "non-peroxide ammonium salt" means any ammonium salt that does not contain an --OO-- bond.

[0034] The non-peroxide ammonium salt is specifically different from ammonium percarbonate, ammonium perborate, or ammonium persulfate.

[0035] This ammonium salt is different from ammonium hydroxide.

[0036] The ammonium salt may be an inorganic ammonium salt or an organic ammonium salt.

[0037] The term "inorganic salt" refers to a salt that does not contain more than one carbon atom in its structure.

[0038] The inorganic ammonium salts may be acidic, alkaline, or neutral.

[0039] The term "acid salt" refers to a salt that, when present at 5% in water, has a pH of less than 6.5 at 25°C.

[0040] The term "alkaline salt" refers to a salt that, when contained at 5% in water, has a pH greater than 7.5 at 25°C.

[0041] The term "neutral salt" refers to a salt that, when contained at 5% in water, has a pH in the range of 6.5 to 7.5 at 25°C.

[0042] The non-peroxide inorganic ammonium salts with a molar mass greater than 40 g / mol may be chosen from ammonium carbonate, ammonium hydrogen carbonate, ammonium carbamate, ammonium chloride, ammonium sulfate, ammonium hydrogen sulfate, ammonium nitrate, ammonium phosphate, diammonium phosphate, ammonium dihydrogen phosphate.

[0043] The organic ammonium salt may be selected from ammonium lactate, ammonium acetate.

[0044] Preferably, the non-peroxide ammonium salts with a molar mass greater than 40 g / mol are inorganic ammonium salts.

[0045] According to a first variant, the non-peroxide ammonium salt is chosen from acidic non-peroxide inorganic ammonium salts.

[0046] The acidic non-peroxide ammonium salt is preferably chosen from ammonium chloride and ammonium sulfate. According to a first variant, the acidic inorganic ammonium salt is preferably ammonium chloride.

[0047] According to a second variant, the non-peroxide ammonium salt is chosen from alkaline non-peroxide inorganic ammonium salts. This alkaline inorganic ammonium salt is preferably chosen from ammonium carbonate, ammonium hydrogen carbonate, ammonium carbamate, ammonium phosphate. According to this second variant, the alkaline inorganic salt is ammonium carbonate.

[0048] Preferably, the non-peroxide ammonium salts with a molar mass greater than 40 g / mol are selected from ammonium chloride, ammonium carbonate and ammonium hydrogen carbonate.

[0049] The non-peroxide ammonium salts may be present in the oxidizer composition in a total amount ranging from 0.1% to 20% by weight, preferably from 0.5% to 15% by weight, and more preferably from 1% to 10% by weight, based on the total weight of the oxidizer composition.

[0050] Furthermore, the oxidizing agent composition may also contain an alkaline agent different from the non-peroxide ammonium salts having a molar mass greater than 40 g / mol.

[0051] The term "alkaline agent" means any agent that increases the pH of the composition in which it is present.

[0052] This may be inorganic or organic.

[0053] More specifically, the alkaline agents that can be used in the oxidizer composition of the present invention are: a) aqueous ammonia, b) organic amines, such as mono-, di-, and triethanolamine, isopropanolamine, and alkanolamines such as 2-amino-2-methyl-1-propanol as well as derivatives thereof; c) oxyethylenated and / or oxypropylenated ethylenediamines; d) inorganic or organic hydroxides; e) alkali metal silicates such as sodium metasilicate; f) amino acids, preferably basic amino acids such as arginine, glycine, lysine, ornithine, citrulline, and histidine, or alkali metal or alkaline earth metal salts thereof; g) carbonates and hydrogen carbonates, in particular of primary, secondary or tertiary amines or of alkali metals or alkaline earth metals; h) The following formula (III): [ka] (wherein X is a linear or branched C1-C6 alkylene group optionally substituted with one or more hydroxyls or C1-C6, better still a C1-C4 alkyl group; Rx, Ry, Rz, and Rt may be the same or different and represent a hydrogen atom or a C1-C6 alkyl group, a C1-C6 hydroxyalkyl group, or a C1-C6 aminoalkyl group).

[0054] Examples of such compounds of formula (III) include 1,3-diaminopropane and 1,3-diamino-2-propanol.

[0055] The inorganic or organic hydroxide is preferably selected from alkali metal hydroxides, alkaline earth metal hydroxides, such as sodium hydroxide or potassium hydroxide, transition metal hydroxides, such as hydroxides of metals from groups III, IV, V and VI of the periodic table of the elements, lanthanide or actinide hydroxides, and guanidinium hydroxide.

[0056] The hydroxide can also be formed in situ, for example guanidine hydroxide is formed by reacting calcium hydroxide with guanidine carbonate.

[0057] Preferred alkaline agents are in particular selected from aqueous ammonia, organic amines, in particular alkanolamines such as monoethanolamine, triethanolamine and 2-amino-2-methyl-1-propanolol, alkali metal or alkaline earth metal hydroxides, sodium carbonate and sodium hydrogen carbonate, alkali metal or alkaline earth metal (meta)silicates, in particular sodium (meta)silicate, arginine, sodium glycine or potassium glycine, and mixtures thereof.

[0058] Preferably, the alkaline agent is selected from alkali metal or alkaline earth metal (meta)silicates, more preferably, the alkaline agent is selected from sodium (meta)silicate.

[0059] When an alkaline agent is present, its total content is 0.1 mass % to 20 mass %, preferably 0.2 mass % to 15 mass %, and more preferably 0.3 mass % to 10 mass %, based on the total mass of the oxidizing agent composition.

[0060] According to one variant, the oxidizer composition comprises hydrogen peroxide and at least one alkaline non-peroxide inorganic ammonium salt, preferably selected from ammonium carbonate and ammonium bicarbonate, more preferably selected from ammonium carbonate.

[0061] According to this variant, the oxidizing agent composition also does not necessarily comprise an alkaline agent different from a non-peroxide ammonium salt having a molar mass greater than 40 g / mol.

[0062] Preferably, the oxidizer composition comprises less than 5% by weight of peroxide salt based on the total weight of the composition, preferably less than 3% peroxide salt, more preferably less than 1% peroxide salt. More preferably, the oxidizer composition is free of peroxide salt.

[0063] The oxidant composition may preferably comprise one or more hair dyes selected from direct dyes and oxidative dyes.

[0064] The oxidizer composition is aqueous.

[0065] The oxidizing agent composition contains water in an amount in the range of 20% by mass to 70% by mass, preferably in the range of 30% by mass to 60% by mass, based on the total mass of the oxidizing agent composition.

[0066] The pH of the oxidizing composition is preferably between 7.5 and 12, preferably between 8 and 11, and better still between 9 and 10.5.

[0067] The oxidizer composition can be in a variety of forms, such as a solution, emulsion, or gel.

[0068] The oxidizer composition can be obtained by mixing at least two compositions.

[0069] Specifically, the oxidizing agent composition can be obtained by mixing a composition (A) comprising at least one non-peroxide ammonium salt having a molar mass greater than 40 g / mol and, optionally, at least one alkaline agent different from the non-peroxide ammonium salt, with a composition (B) comprising hydrogen peroxide and, optionally, a third composition comprising at least one alkaline agent different from the non-peroxide ammonium salt having a molar mass greater than 40 g / mol.

[0070] Composition (A) is preferably anhydrous.

[0071] The term "anhydrous composition" for the purposes of the present invention means a composition having a water content of less than 5% by weight, preferably less than 2% by weight, and / or a composition that does not contain any added water, i.e. the water that may be present in the composition according to the invention is more particularly bound water, such as water of crystallization of salts or traces of water absorbed by the starting materials used for the preparation of the composition according to the invention.

[0072] Composition (B) is preferably aqueous.

[0073] The oxidizing agent compositions, Composition (A) and Composition (B), may further comprise one or more auxiliaries, such as solvents, fatty substances, anionic, cationic, nonionic, amphoteric or zwitterionic polymers or mixtures thereof, anionic, nonionic, cationic and / or amphoteric surfactants, inorganic thickeners, in particular fillers such as clays or talc, organic thickeners, in particular anionic, cationic, nonionic and amphoteric associative polymeric thickeners, pigments, antioxidants, penetrating agents, sequestering agents, fragrances, dispersing agents, film-forming agents, ceramides, preservatives, opacifying agents, antidandruff agents, anti-hair loss agents.

[0074] Irradiation step As indicated above, the method according to the invention comprises applying to the keratin fibres, after application of the composition, a UV-visible radiation having a wavelength in the range of 200-800 nm at a dose of 1-5000 J / cm. 2 The method includes irradiating the light with a fluence in the range of 100 .mu.m to 100 .mu.m.

[0075] Preferably, 90% of the energy of the radiation emitted by the irradiation source is between 200 and 800 nm, more preferably, 95% of the energy of the radiation emitted by the irradiation source is between 200 and 800 nm.

[0076] In one preferred variant of the invention, the light source emits "monochromatic" radiation, i.e. radiation centred on a given wavelength and with a very narrow dispersion of the emitted energy of ±10 nanometres relative to said wavelength.

[0077] Preferably, the wavelength of the UV-visible radiation is in the range of 280 to 700 nm, in particular in the range of 350 to 500 nm.

[0078] More specifically, the wavelength of the UV-visible radiation is 385 nm, 405 nm, or 455 nm (±10 nanometers).

[0079] The fluence of UV-visible radiation is 1-5000 J / cm 2in the range of 1 to 2000 J / cm 2 in the range of 10 to 1000 J / cm 2 in the range of 20-800 J / cm 2 is in the range.

[0080] Advantageously, the irradiation step of the method according to the invention is carried out using one or more light sources, preferably one or more light emitting sources.

[0081] More preferably, the UV-visible radiation is emitted from one or more light emitting sources consisting of light emitting elements such as one or more Light Emitting Diodes (LEDs) or Organic Light Emitting Diodes (OLEDs).

[0082] The light emitting source can be selected from a light emitting diode (LED) or an organic light emitting diode (OLED).

[0083] In other words, the irradiation step is carried out using one or more light emitting sources, which makes it possible to effectively reduce the processing time of the method of the present invention.

[0084] Preferably, the illumination source may consist of one or more light emitting diodes.

[0085] Furthermore, diodes have the advantage that they are easily miniaturized and have high energy, and they also make it possible to shorten the irradiation time for a given fluence.

[0086] In particular, the radiation source used in the method of the invention is supported on a clamp that can be moved along the hair bundle, as described in French patent application no. 1 903 781.

[0087] The UV-visible radiation may be continuous or pulsed with a pulse frequency in the range of 0.001-1000 Hz, preferably in the range of 0.01-100 Hz.

[0088] In one variant of the invention, the irradiance of the radiation emitted by the irradiation source on the substrate to be treated is between 1 and 50 W / cm 2 The time varies between 0 and 100 ms.

[0089] Preferably, the keratin fibers after treatment with the oxidizing composition are irradiated for a period of less than 60 minutes. In particular, the irradiation time varies in the range of 1 to 60 minutes, more preferably 1 to 30 minutes, more preferably 1 to 20 minutes, in particular 1 to 5 minutes.

[0090] The illumination source may be moved along the hair bundle one or more times in succession.

[0091] Preferably, after the oxidizing agent composition has been applied to the keratinous fibers, an accessory such as a film or wrapper can be placed on the keratinous fibers before the irradiation step is performed.

[0092] The aid may be capable of containing the keratinous fibers onto which the oxidizing agent composition has been applied.

[0093] Preferably, the aid is transparent to the irradiating wavelength.

[0094] Preferably, the time for which the oxidizing agent composition is left on the keratin fibers before the irradiation step may be less than 30 minutes, preferably less than 10 minutes, more preferably less than 5 minutes.

[0095] Preferably, the irradiation step is carried out immediately after application of the oxidizing agent composition onto the keratinous fibers.

[0096] The expression "immediately after" is understood to mean less than 5 minutes after application of the composition has been completed or after placing an auxiliary such as a film or wrapper on the keratinous fibers, in other words, no time is required to leave the oxidizing composition on the keratinous fibers.

[0097] Preferably, the method according to the present invention also includes a step of rinsing the oxidizer composition after the irradiation step.

[0098] According to one variant of the invention, the oxidizing agent composition is applied to a portion of the surface of the keratinous fibres, and then, in a second step, said portion or all of the surface is irradiated with UV-visible radiation as defined above.

[0099] According to another variant of the invention, the oxidizing composition is applied to the entire surface of the keratin fibres, and then in a second step, the entire surface is irradiated with UV-visible radiation as defined above.

[0100] According to a third variant of the invention, after the oxidizing agent composition has been applied to the entire surface of the keratinous fibres, in a second step, a portion of said surface (which portion of the surface can be predetermined) is irradiated with UV-visible radiation as defined above.

[0101] Such an embodiment makes it possible to create a lightened pattern on the keratin fiber surface.

[0102] The present invention also relates to a method for bleaching keratinous fibres, in particular human keratinous fibres such as hair, comprising the steps of: - mixing a first composition (A) comprising at least one non-peroxide ammonium salt having a molar mass greater than 40 g / mol and, optionally, at least one alkaline agent different from the non-peroxide ammonium salt having a molar mass greater than 40 g / mol, with a second composition (B) comprising hydrogen peroxide and, optionally, a third composition comprising at least one alkaline agent different from the non-peroxide ammonium salt having a molar mass greater than 40 g / mol, in order to obtain an oxidizer composition having a pH greater than or equal to 7.5; then - applying an oxidizing agent composition to said fibers; and then - the fiber is irradiated with a wavelength in the range of 200 to 800 nm and a fluence of 1 to 5000 J / cm 2 and exposing the substrate to UV-visible radiation in the range of 0.1 to 0.5 μm.

[0103] The following examples serve to illustrate the invention without, however, limiting its nature.

[0104] The keratin fibres used in the following examples are hair of tone level 4 (TL4), which corresponds to chestnut brown hair strands.

[0105] The concept of "tone level" is based on a division of natural shades, with each shade being a tone and separated from the adjacent shades before and after it. This definition and the division of natural shades is well known to professional hair stylists and is described in the book "Sciences des traitements capillaires (Hair treatment science)" by Charles Zviak, published by Masson in 1988, pages 215 and 278.

[0106] Tone levels are divided into a scale from 1 (black) to 10 (very light blonde), with each unit corresponding to one tone level and the higher the number, the lighter the shade. EXAMPLES

[0107] Example 1 A. Test Composition The compositions shown below were prepared from the ingredients shown in the following table, amounts expressed as weight percentage of active material.

[0108] [Table 1]

[0109] These compositions in powder form are mixed with the following aqueous composition containing hydrogen peroxide in a ratio of 1+3 (A+B):

[0110] [Table 2]

[0111] B. Light source A blue LED array is used, which is constructed from several blue light emitting diodes (LEDs). The central wavelength of the blue light is 405 nm.

[0112] This device is 18cm 2 The source consists of a number of appropriately mounted light emitting diodes sufficient to illuminate a surface area of ​​1000 m2. This source produces a total fluence of 1-5000 J / cm2. 2 A portion of the hair bundle is illuminated and the light source is moved periodically so that the fluence delivered to the entire hair bundle is equal.

[0113] C. Procedure The various mixtures obtained are applied to hair tresses of tone level TL4 in a ratio of 10 grams of mixture per gram of hair tress, which are then wrapped in a wrapper transparent to the irradiated wavelength.

[0114] Each hair bundle was exposed to a fluence of 80 J / cm 2 The hair strand is irradiated for 160 seconds with a wavelength of 405 nanometers so that the entire strand is not irradiated at once. The light source is moved periodically along the strand.

[0115] The hair strands are rinsed and then washed with shampoo.

[0116] D. Results Lightness of hair bundle color L * is measured using a Minolta Spectrophotometer CM2600D colorimeter.

[0117] The change in the color brightness ΔL of the hair strand before and after treatment with the method according to the invention is calculated according to the following formula: ΔL=L * -L0 * (L * represents the measured value after processing, and L0 * indicates the measurement value before treatment).

[0118] The higher the value of ΔL, the greater the difference in color before and after treatment, and in this example the more bleached the locks are.

[0119] The results are shown in Table 1 below.

[0120] [Table 3]

[0121] It is found that the method according to the invention makes it possible to effectively bleach hair strands.

[0122] Example 2 A. Test Composition The following oxidizer compositions are prepared, the amounts of which are expressed as percentages by weight of active material:

[0123] [Table 4]

[0124] The molar amounts of the ammonium source in the two compositions are equal.

[0125] B. Light source The same light source as in Example 1 is used.

[0126] C. Procedure Compositions (C) and (C1) are each applied to a hair tress having a tone level of TL4 at a rate of 10 grams per gram of hair tress, and these are then wrapped in a wrapping material that is transparent to the irradiated wavelength.

[0127] Each hair bundle was exposed to a fluence of 80 J / cm 2 The hair strand is irradiated for 160 seconds with a wavelength of 405 nanometers so that the entire strand is not irradiated at once. The light source is moved periodically along the strand.

[0128] The hair strands are rinsed and then washed with shampoo.

[0129] D. Result: Color comparison The color of the hair strands was evaluated in the CIE L*a*b* system using a Minolta Spectrophotometer CM2600D colorimeter. *a * b * The three parameters of the system are lightness (L * ), green / red axis (a * ), and blue / yellow axis (b * )

[0130] The table shows the colorimetric parameters L for untreated hair tresses (TL4), hair tresses treated with the method according to the invention (TL4) and hair tresses treated with the comparative method using composition (C1) (TL4). * , a * , and b * Shows.

[0131] [Table 5]

[0132] It can be seen that, when the amounts of activator used are equal, the method according to the invention achieves better decolorization than the comparative method.

[0133] Example 3 A. Test Composition Compositions (A8) and (B) from Example 1 are used.

[0134] B. Light source The same light source as in Example 1 is used.

[0135] C. Procedure 1) Method 1 To obtain the oxidizer composition, compositions (A8) and (B) are mixed in a ratio of 1:3. The oxidizer composition is then applied to a chestnut-colored hair tress (TL4) in a ratio of 10 grams of oxidizer composition per gram of hair tress. The hair tress is then wrapped in a wrapper transparent to the irradiating wavelength and immediately exposed to a fluence of 80 J / cm. 2 The hair bundle is then exposed to light for 160 seconds so that the hair is completely irradiated. The hair bundle is then rinsed.

[0136] 2) Method 2 (conventional bleaching method using persalt) A composition named "Infinie Platine Low odor" from L'Oreal Professionnel is mixed with a 30-volume oxidant (Developpeur Oxydant Creme 30 volumes from L'Oreal Professionnel) in a ratio of 1:1.5. The composition obtained from this mixture is applied to a chestnut-colored hair tress (TL4) at a rate of 10 grams of oxidant composition per gram of hair tress. The composition is left on the hair tress for 40 minutes at 33°C. The hair tress is then rinsed.

[0137] D. Result: Color comparison The color of the hair bundle was measured using a Minolta Spectrophotometer CM2600D colorimeter in the CIE L * a * b * This L * a * b * The three parameters of the system are lightness (L * ), green / red axis (a * ), and blue / yellow axis (b * )

[0138] The following table shows the colorimetric parameters L for untreated hair tresses (TL4), hair tresses treated by the prior art method (Method 2) and hair tresses treated by the method according to the invention (Method 1). * , a * , and b * Also, Δa * and Δb * The values ​​of a0 and a1 of the untreated hair bundle are * and a of bleached hair bundle * and the value obtained from b0 of the untreated hair bundle * and b of bleached hair bundles * This is the value calculated from

[0139] [Table 6]

[0140] It is observed that, for equal degrees of bleaching with respect to (L), the bleaching method according to the present invention (Method 1) lightens more faithfully to natural tone levels than the prior art methods, without rendering the lightened background color yellow / orange-tinted.

[0141] In fact, the a obtained using the method according to the present invention * value and b * The value was obtained by the method of the prior art. * value and b * The initial value of the untreated TL4 hair bundle, a0 * and b0 * Therefore, the hair tresses bleached using method 2 have a redder color (a) than the hair tresses bleached using the method according to the present invention. * ) and yellowish (b * ) is strong.

[0142] Example 4 A. Test Composition The following oxidizer compositions are prepared, the amounts of which are expressed as percentages by weight of active material:

[0143] [Table 7]

[0144] The molar amounts of the ammonium source in the two compositions are equal.

[0145] B. Light source The same light source as in Example 1 is used.

[0146] C. Procedure Compositions (D) and (D1) are each applied to a hair tress having a tone level of TL4 at a rate of 10 grams per gram of hair tress, and these are then wrapped in a wrapping material that is transparent to the irradiated wavelength.

[0147] Each hair bundle was exposed to a fluence of 80 J / cm 2 The hair strand is irradiated for 160 seconds with a wavelength of 405 nanometers so that the entire strand is not irradiated at once. The light source is moved periodically along the strand.

[0148] The hair strands are rinsed and then washed with shampoo.

[0149] D. Result: Color comparison The color of the hair bundle was measured using a Minolta Spectrophotometer CM2600D colorimeter in the CIE L * a * b * This L * a * b * The three parameters of the system are lightness (L * ), green / red axis (a * ), and blue / yellow axis (b * )

[0150] The table shows the colorimetric parameters L for untreated hair tresses (TL4), hair tresses treated by the method according to the invention with composition (D) (TL4) and hair tresses treated by the comparative method with composition (D1) (TL4). * , a * , and b * Shows.

[0151] [Table 8]

[0152] It can be seen that, when the amounts of activator used are equal, the method according to the invention achieves better decolorization than the comparative method.

Claims

1. 1. A method for bleaching human hair comprising: (i) applying to the hair, at least one non-peroxide ammonium salt selected from ammonium carbonate, ammonium bicarbonate, ammonium chloride, ammonium sulfate, ammonium lactate, ammonium acetate, having a molar mass greater than 40 g / mol; - hydrogen peroxide; - optionally at least one alkaline agent different from said non-peroxide ammonium salts having a molar mass greater than 40 g / mol; applying an oxidant composition comprising: the pH of the oxidizer composition is 7.5 or greater; the oxidizer composition comprises one or more non-peroxide ammonium salts having a molar mass greater than 40 g / mol in a total amount ranging from 0.1% to 20% by weight, based on the total weight of the oxidizer composition; a total content of hydrogen peroxide in the oxidizer composition varies between 0.5% and 12% by weight, based on the total weight of the oxidizer composition; (ii) applying a fluence of 1 to 2000 J / cm to the hair having a wavelength in the range of 280 to 700 nm and a fluence of 1 to 2000 J / cm ２ for a time period ranging from 1 to 20 minutes after application of the composition. The method includes:

2. The method of claim 1 , wherein the illuminating step is performed using one or more light emitting sources selected from light emitting diodes (LEDs) or organic light emitting diodes (OLEDs).

3. The method according to claim 1 or 2, wherein the hair, after being treated with the oxidizing composition, is irradiated for a period ranging from 1 to 5 minutes.

4. The method of any one of claims 1 to 3, wherein the non-peroxide ammonium salt is an inorganic ammonium salt.

5. The method according to any one of claims 1 to 4, wherein the non-peroxide ammonium salt is selected from acidic non-peroxide inorganic ammonium salts.

6. The method according to any one of claims 1 to 4, wherein the non-peroxide ammonium salt is selected from alkaline non-peroxide inorganic ammonium salts.

7. 7. The method according to any one of claims 1 to 6, wherein the alkaline agent different from the non-peroxide ammonium salts having a molar mass of more than 40 g / mol is selected from aqueous ammonia, organic amines, alkanolamines, monoethanolamine, triethanolamine, 2-amino-2-methyl-1-propanolol, alkali metal or alkaline earth metal hydroxides, sodium carbonate and sodium hydrogen carbonate, alkali metal or alkaline earth metal (meta)silicates, sodium (meta)silicate, arginine, sodium glycine or potassium glycine, and mixtures thereof.

8. 8. The method according to any one of claims 1 to 7, wherein the oxidizer composition comprises one or more alkaline agents different from the non-peroxide ammonium salts having a molar mass greater than 40 g / mol, in a total amount ranging from 0.1% to 20% by weight, based on the total weight of the oxidizer composition.

9. 9. The method according to claim 1, wherein the oxidizer composition contains less than 5% by weight of peroxide salt, based on the total weight of the composition, or is free of peroxide salt.

10. The method of any one of claims 1 to 9, wherein the oxidant composition comprises one or more hair dyes selected from direct dyes and oxidative dyes.

11. The method of any one of claims 1 to 10, wherein the pH of the oxidizer composition is from 7.5 to 12.

12. 12. The method according to any one of the preceding claims, wherein, prior to step i) of applying the oxidant composition, a first composition (A) comprising at least one non-peroxide ammonium salt having a molar mass greater than 40 g / mol and, optionally, at least one alkaline agent different from said non-peroxide ammonium salt having a molar mass greater than 40 g / mol is mixed with a second composition (B) comprising hydrogen peroxide and, optionally, a third composition comprising at least one alkaline agent different from said non-peroxide ammonium salt having a molar mass greater than 40 g / mol, in order to obtain the oxidant composition for application to the hair in step i).

13. A method according to any one of the preceding claims, characterized in that the oxidant composition is rinsed off after the hair irradiation step.

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