JP2012157388A - Hair discoloring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for decoloring hair capable of obtaining decolorized hair with sufficiently little damage.
SOLUTION: The decolorization method of the present invention applies pulse laser light having a wavelength of 600 to 1200 nm to hair, a fluence of 1 × 10 ^{−11 to} 0.1 J / cm ² , and an energy intensity of 50 W / cm ^{2 to 2} GW. Irradiation is performed under the condition of / cm ² .
[Selection figure] None

Description

  The present invention relates to a method for decolorizing hair.

  In recent years, due to the diversification of personality expression, a large number of hair dyes of various colors corresponding to gray hair dyeing and fashion dyeing have been developed and marketed. Among hair dyes, in particular, an oxidation hair dye that mixes a first agent containing an oxidation dye and an alkali agent and a second agent containing hydrogen peroxide is widely used. In hair dyeing with such an oxidative hair dye, active oxygen generated from hydrogen peroxide oxidizes and decomposes the melanin pigment in the hair and decolorizes the hair. By polymerization, a semi-permanent dyed hair is obtained.

  However, the above-mentioned oxidative hair dye has the disadvantage that the active oxygen generated from hydrogen peroxide also breaks down the binding of keratin in the hair, so that the hair loses moisture and feels dry and squeaky. . Then, the 1st agent aiming at reducing the hair damage by hydrogen peroxide is proposed. For example, Patent Document 1 below proposes a first agent for a decoloring agent in which cystine or a derivative thereof is mixed with an alkaline agent. Patent Document 2 below proposes a first agent containing an amine polymer and ammonia. However, since these first agents are formulations containing an alkaline agent for activating hydrogen peroxide, hair damage cannot be sufficiently reduced.

On the other hand, there is a method for decolorizing hair without using hydrogen peroxide. For example, Patent Document 3 below discloses a hair bleaching agent containing a considerable amount of ascorbic acid or a derivative thereof. Patent Document 4 listed below discloses a hair photobleaching method in which a composition containing α-oxycarboxylic acids and the like is applied to hair and then exposed to light of 400 nm to 800 nm. Furthermore, the following Patent Document 5 discloses a method of bleaching by irradiating hair with laser light of 0.1 to 1.2 J / cm ² per pulse.

JP 2002-370952 A JP 2002-326916 A JP-A-5-78229 JP 2005-145890 A JP-A-8-71166

  However, the hair bleaching agent described in Patent Document 3 and the method disclosed in Patent Document 4 cannot sufficiently decolor the hair. On the other hand, the method disclosed in Patent Document 5 cannot be said that hair damage is sufficiently small, and when the laser irradiation is performed until a desired degree of bleaching is achieved, bleaching hair having a feel comparable to natural hair is obtained. I can't.

  An object of this invention is to provide the decoloring method of the hair which can obtain the decoloring hair with sufficient damage.

  In order to solve the above problems, the present inventors have made extensive studies focusing on decolorization of hair with pulsed laser light, and as a result, irradiated pulsed laser light having a specific wavelength to hair under specific conditions. The present inventors have found that decolorized hair that can be decolorized without damaging the hair tissue and that has a feel comparable to natural hair can be obtained. And the present inventors came to complete this invention based on this knowledge.

That is, according to the present invention, pulse laser light having a wavelength of 600 to 1200 nm is applied to hair, the fluence is 1 × 10 ^{−11 to} 0.1 J / cm ² , and the energy intensity is 50 W / cm ^{2 to 2} GW / cm ^2. Provided is a method for decolorizing hair irradiated under conditions.

  According to the method for decoloring hair of the present invention, by irradiating the hair with the above-mentioned pulse laser beam, the hair can be decolored without damaging the hair tissue, and decolorized hair with sufficiently little damage can be obtained. As a result, it is possible to obtain decolorized hair having a feel comparable to natural hair.

  ADVANTAGE OF THE INVENTION According to this invention, the decoloring method of the hair which can obtain the decoloring hair with sufficient damage can be provided. According to the method for decoloring hair of the present invention, the degree of damage to the strength and elongation of the hair can be made sufficiently small, the state of moisture and cuticles is maintained well, and the decolorization has a sufficiently soft and squeaky feeling. Hair can be obtained.

In the decolorization method of the present invention, a pulse laser beam having a wavelength of 600 to 1200 nm is applied to hair, a fluence of 1 × 10 ^{−11 to} 0.1 J / cm ² and an energy intensity of 50 W / cm ^{2 to 2} GW / cm ² . Irradiation is performed under the following conditions.

  By irradiating with pulsed laser light under the above conditions, only the melanin pigment component in the hair can be decomposed without damaging the hair tissue such as cuticle, cortex, medulla and the like. Thereby, decoloring hair with sufficient damage can be obtained.

  When the wavelength of the pulse laser beam to be irradiated is shorter than 600 nm, even if the energy intensity and the fluence are within the ranges according to the present invention described above, the hair feels dry and squeaky, and the cuticle peeling rate is further increased. It will increase. For this reason, the present inventors believe that the pulse laser beam having a wavelength shorter than 600 nm acts on the hair surface, so that the cuticle is destroyed and the cortex is further destroyed. Further, when a pulse laser beam having a short wavelength of less than 600 nm is irradiated in the vicinity of the hair root, the human body may be adversely affected.

  On the other hand, when the wavelength of the pulsed laser light to be irradiated is longer than 1200 nm, when the hair is sufficiently decolored, the feeling of squealing, squeaky, and peeling of the cuticle increase. For this reason, the present inventors believe that the pulse laser light having a wavelength longer than 1200 nm tends to vaporize the water inside the hair, which causes cortex to expand and break, and the cuticle to break.

  In the present invention, a more preferable wavelength of the pulse laser beam is 650 nm to 1100 nm.

Even if the energy intensity is within the range according to the present invention, if the fluence is less than 1 × 10 ⁻¹¹ J / cm ² , sufficient thermal energy for thermal decomposition of the melanin pigment cannot be obtained, and the hair is sufficiently obtained. It becomes impossible to decolorize. On the other hand, if the fluence exceeds 0.1 J / cm ² , the hair feels dry and squeaky, and the rate of separation of the cuticle further increases. The present inventors consider this reason as follows. In other words, heat energy propagates to the cortex around the melanin pigment, causing heat damage to the cortex and vaporizing water inside the hair, causing the cortex to expand and break, and further, the cuticle is also destroyed by this expansion. The inventors are thinking.

When the energy intensity of the pulse laser beam is less than 50 W / cm ² , it is impossible to obtain the thermal energy necessary for the thermal decomposition of the melanin pigment, and the hair cannot be sufficiently decolored. On the other hand, when the energy intensity exceeds ² GW / cm ² , the hair feels dry and squeaky, and the percentage of cuticle peeling further increases. The present inventors consider this reason as follows. In other words, heat energy propagates to the cortex around the melanin pigment, causing heat damage to the cortex and vaporizing water inside the hair, causing the cortex to expand and break, and further, the cuticle is also destroyed by this expansion. The inventors are thinking.

  As described above, the pulse laser light irradiation to the hair in the present invention acts on the melanin pigment and decomposes it, but heat does not propagate to the surrounding tissue of the melanin pigment, Decolorization is possible while suppressing hair damage.

Examples of means for irradiating pulsed laser light under the conditions of the present invention include pulsed laser oscillators such as solid lasers, semiconductor lasers, and fiber lasers. Examples of the laser medium include titanium-sapphire, Yb: KY (WO ₄ ) ₂ , Yb: YAG, Cr: LiSaF, Nd: glass, semiconductor, and fiber.

The energy intensity of the pulsed laser beam is a value represented by energy intensity (W / cm ² ) = fluence (J / cm ² ) / pulse width (sec). By adjusting the pulse width according to the fluence, Can be within the scope of the present invention.

  Although there is no restriction | limiting in particular as a repetition frequency of pulse laser beam, The repetition frequency of the wide range of 1 Hz-10 GHz can be taken. In order to decolorize hair in a short time, it is preferable to set a high repetition frequency, and a repetition frequency of 100 Hz or more is desirable.

  There is no restriction | limiting also in the beam radius of pulse laser beam, and a shape, For example, it can take various shapes, such as a circular shape of 0.01-10 mm, an ellipse, and a rectangle. When the beam radius is large, it is possible to decolor hair in a short time even if the repetition frequency is small. When the beam radius is small, the hair can be decolorized in a short time by increasing the repetition frequency.

The pulse width of the pulsed laser light is not particularly limited, and can be, for example, 100 femtoseconds (1 × 10 ⁻¹³ seconds) to 10 nanoseconds (1 × 10 ⁻⁸ seconds). As the pulse width of the laser beam is shorter, the heat propagation decreases and damage to the hair can be suppressed. Therefore, the pulse width is preferably 1 ns or less.

  There is no limitation on the method of irradiating the hair with pulsed laser light. Fixing the hair and irradiating the pulsed laser light, fixing the pulsed laser light and irradiating the hair, fixing both the hair and the pulsed laser light It is possible to irradiate the hair with pulsed laser light without doing so.

  In the present invention, imprinting on the hair can be performed by irradiating a specific portion of the hair with pulsed laser light.

  In the present invention, by irradiating pulsed laser light under the conditions according to the present invention, not only melanin pigment in hair but also hair dyed with oxidation dye, acid dye, basic dye, direct dye, natural dye These dyes can also be decomposed and decolorized without damaging the hair tissue.

  Examples of oxidative dyes that can be decolorized by the decolorization method of the present invention include intermediates such as p-phenylenediamine, p-toluylenediamine, 4-aminophenol, tetraaminopyrimidine, triaminohydroxypyrimidine, and resorcinol, 2 -Methylresorcinol, 4-chlororesorcinol, 2-aminophenol, 4- (N-methylamino) phenol, 3-aminophenol, 3-N, N-dimethylaminophenol, 4-amino-3-methylphenol, 5- Amino-2-methylphenol, 6-amino-3-methylphenol, 3-amino-2-methylamino-6-methoxypyridine, 2-amino-3-hydroxypyridine, 4-aminodiphenylamine, 4,4'-diamino Diphenylamine, 2-dimethylamino-5-amino Pyridine, 2,6-diaminopyridine, 1,2-diaminobenzene, 1,3-diaminobenzene, 1-amino-3- (2'-hydroxyethylamino) benzene, 1-amino-3- [bis (2 ' -Hydroxyethyl) amino] benzene, 1,3-diaminotoluene, α-naphthol, 1,4-diamino-2-chlorobenzene, 4,6-dichlororesorcinol, 4-hydroxy-1,2-methylenedioxybenzene, 1 , 5-dihydroxynaphthalene, 2,4-diamino-3-chlorophenol, 1,7-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1-hydroxynaphthalene, 4-hydroxy-1,2-methylenedioxybenzene, 2, , 4-Diamino-3-chlorophenol, 1-methoxy-2-amino-4- (2'-hy And a coupling substance such as droxyethylamino) benzene.

  Examples of acid dyes that can be decolorized by the decoloring method of the present invention include Red No. 2, Red No. 3, Red No. 102, Red No. 104 (1), Red No. 105 (1), Red No. 106, and Red 201. No., Red 227, Red 230 (1), Red 230 (2), Red 231, Red 232, Red 401, Red 502, Red 503, Red 504, Red 506, Yellow No. 4, Yellow No. 5, Yellow No. 202 (1), Yellow No. 202 (2), Yellow No. 203, Yellow No. 402, Yellow No. 403 (1), Yellow No. 406, Yellow No. 407, Orange No. 205, orange No. 207, orange No. 402, green No. 3, green No. 204, green No. 205, green No. 401, green No. 402, purple No. 401, blue No. 1, blue No. 2, blue No. 202, blue 203, blue 205, brown 01 items, and the like No. 401 black.

  Examples of basic dyes that can be decolored by the decoloring method of the present invention include, for example, Basic Blue No. 6, Basic Blue No. 7. Basic Blue No. 7 9. Basic Blue No. 9 26, Basic Blue No. 41, Basic Blue No. 41 99, Basic Violet No. 1, Basic Violet No. 2, Basic Violet No. 3, Basic Violet No. 10, Basic Violet No. 14, Basic Brown No. 4, Basic Brown No. 16, Basic Brown No. 17, Basic Red No. 2, Basic Red No. 22, Basic Red No. 76, Basic Yellow No. 11, Basic Yellow No. 57, Basic Green No. 1 etc. are mentioned.

  Examples of the direct dye that can be decolored by the decoloring method of the present invention include, for example, nitro dyes, azo dyes, nitroso dyes, triphenylmethane dyes, xanthene dyes, quinoline dyes, anthraquinone dyes, indigo dyes, and the like. , Nitroparaphenylenediamine, paranitroorthophenylenediamine, paranitrometaphenylenediamine, 2-amino-4-nitrophenol, 2-amino-5-nitrophenol, picramic acid, N1, N4, N4-tris (2-hydroxy Ethyl) -2-nitroparaphenylenediamine, 4-[(2-nitrophenyl) amino] phenol, N1- (2-hydroxyethyl) -2-nitroparaphenylenediamine, 2,2 ′-[(4-amino- 3-nitrophenyl) imino] bisethanol, N- (2-H Loxyethyl) -2-nitroaniline, 2-[[2- (2-hydroxyethoxy) -4-nitrophenyl] amino] ethanol, N1- (2-hydroxyethyl) -4-nitroorthophenylenediamine and salts thereof, 1,4-diaminoanthraquinone and the like can be mentioned.

  Examples of natural dyes that can be decolorized by the decoloring method of the present invention include carotenoids, anthraquinones, flavonoids (anthocyanins, chalcones, flavones), polyfinins, diketones, betacyanines, azophyllones, and the like. Specifically, Akane pigment, Anato pigment, Pavilica pigment, gardenia yellow pigment, extracted carotene, cochineal pigment, lac pigment, red cabbage pigment, perilla pigment, purple corn pigment, elderberry pigment, boysenberry pigment, grape skin pigment, Grape juice pigment, purple potato pigment, safflower yellow pigment, safflower red pigment, cucumber pigment, onion pigment, cacao pigment, sandalwood pigment, spirulina pigment, florophile, turmeric pigment, beed red, red potato red pigment Gardenia blue pigment, gardenia red pigment, Tamari Mention may be made of de dyes.

  The hair removed by the decoloring method of the present invention can be dyed using the dyes such as the above-mentioned oxidation dyes, acid dyes, basic dyes, direct dyes and natural dyes.

  EXAMPLES The present invention will be further described below with reference to examples, but the present invention is not limited to these examples.

<1. Hair decoloration test>
In this example, a pulse laser oscillator using titanium-sapphire or Yb: YAG as a medium is used to irradiate the following melanin pigment-containing hair, dyed hair 1 and dyed hair 2 with pulsed laser light under predetermined conditions. The decolorization test was conducted.

(1) Melanin pigment-containing hair A bundle of Japanese-derived black hair having a width of about 5 mm, a thickness of about 1 mm, and a length of 15 cm or more was prepared.

(2) Dyed hair 1 (hair dyed with oxidation dye)
Japanese-derived gray hair was immersed in an aqueous solution of 0.2% by mass of p-phenylenediamine, 0.2% by mass of resorcinol and 3.0% by mass of hydrogen peroxide for 20 minutes, then washed with water and air-dried. . From the obtained dyed hair, a bundle of hair having a width of about 5 mm, a thickness of about 1 mm, and a length of 15 cm or more was prepared.

(3) Dyed hair 2 (hair dyed with acid dyes and natural dyes)
Japanese-derived gray hair was immersed in an aqueous solution containing 0.1% by weight of black No. 401 and 0.5% by weight of tamarind dye for 20 minutes, then washed with water and air-dried. From the obtained dyed hair, a bundle of hair having a width of about 5 mm, a thickness of about 1 mm, and a length of 15 cm or more was prepared.

Example 1
A pulse laser beam having an energy intensity of 10 MW / cm ² , a fluence of 0.1 J / cm ² , a wavelength of 1064 nm, a repetition frequency of 10 Hz, a beam radius of 4 mm, a pulse width of 10 ns, and an average output of 0.5 W was irradiated 100 times on the same portion of the hair. . This operation was repeated for the entire hair, and the hair was decolorized.

(Example 2 to Example 8)
In the same manner as in Example 1, the hair was decolorized under the conditions described in Table 1.

(Comparative Examples 1 to 7)
In the same manner as in Example 1, the hair was decolorized under the conditions shown in Table 2.

(Comparative Example 8)
The hair was immersed in an alkaline solution having a pH of 10.5 mixed with ammonium persulfate and hydrogen peroxide for 30 minutes. The same operation was repeated 10 times to depilate the hair.

  About the decolorized hair obtained in Examples 1-8 and Comparative Examples 1-7, according to the following evaluation method, the degree of hair decolorization, the strength damage degree and the elongation damage degree of hair, and the feeling of hairiness The squeaky feeling and cuticle state were evaluated.

[Evaluation method for decolorized hair]
(1) Decolorization degree of hair:
The L value (lightness) of the hair before and after the decolorization test was measured with an SM color computer (manufactured by Suga Test Instruments Co., Ltd.), and the difference in L value (ΔL) was determined.

(2) Strength damage degree and elongation damage degree of hair:
Measure the strength and elongation of hair with RHEO METERNRM-2010J-CW (manufactured by Fudo Kogyo Co., Ltd.), and calculate the degree of strength damage (%) and the degree of elongation strength damage (%) from the following formulas (1) and (2), respectively. Asked.
Strength damage degree (%) = [(strength of untreated hair−strength of treated hair) / (strength of untreated hair)] × 100 (%) (1)
Degree of elongation damage (%) = [(Elongation of untreated hair−Elongation of treated hair) / (Elongation of untreated hair)] × 100 (%) (2)
In the formula, the hair to be treated refers to hair that has been subjected to the decolorization treatment of the above-mentioned examples or comparative examples.

(3) Feeling of dryness A judgment was made according to the following criteria by a specialized panelist.
○: There is no feeling of dryness at all.
Δ: Feels slightly stuffy.
×: Feeling dry

(4) Squeakiness Judgment was made based on the following criteria by a specialized panel.
○: No squeaky feeling.
Δ: Feels slightly squeaky.
×: Feels squeaky.

(5) State of cuticle The surface of the hair was observed with a scanning electron microscope S-2400 (manufactured by Hitachi, Ltd.), and judged according to the following criteria.
A: Not damaged at all.
○: The cut-off rate of the cuticle is 10% or less of the whole hair.
(Triangle | delta): The ratio of peeling of a cuticle exceeds 10% of the whole hair, and is less than 30%.
X: The rate of peeling of the cuticle is 30% or more of the whole hair.

In Examples 1 to 8, in which the energy intensity of the pulse laser beam applied to the hair is 50 W to ² GW / cm ² , the fluence is 1 × 10 ^{−11 to} 0.1 J / cm ² , and the wavelength is 600 to 1200 nm, ΔL value = Decolorized hair of 30 or more was obtained. It was confirmed that the degree of strength damage and elongation damage of the obtained decolorized hair was low, and no feeling of squeaking or squeaking was felt at all. In addition, the cuticle was not damaged.

In Comparative Example 1 and Comparative Example ^{2 in} which the fluence exceeds 0.1 J / cm ² , Example 3 in which the laser wavelength exceeds 1200 nm, and Comparative Example 4 in which the energy intensity exceeds ² GW / cm ² , bleaching hair with ΔL value = 30 or more was gotten. However, exfoliation of the cuticle was observed in 10 to 30% of the whole hair, and the strength damage and elongation damage were also high. These results are thought to be because energy more than that required for pigment destruction propagated to the hair tissue around the pigment and destroyed the tissue.

In Comparative Example 5 having an energy intensity of less than 50 W / cm ² and Comparative Example 6 having a fluence of less than 1 × 10 ⁻¹¹ J / cm ² , the color could not be sufficiently removed. In Comparative Example 7 in which pulsed laser light of less than 600 nm was irradiated, decolorized hair having a ΔL value = 30 or more was obtained, but the strength damage degree and the elongation damage degree were large, and the destruction of the cuticle and cortex was confirmed. In Comparative Example 8 using hydrogen peroxide, sufficient bleaching hair was not obtained, and the ΔL value was about 20. The reason why the degree of elongation damage in Comparative Example 8 was -36% is considered to be due to the peeling of the cuticle.

  According to the method for decoloring hair of the present invention, decolorization can be performed while keeping the hair moist.

Claims (1)

Hair that irradiates hair with pulsed laser light having a wavelength of 600 to 1200 nm under the conditions that the fluence is 1 × 10 ^{−11 to} 0.1 J / cm ² and the energy intensity is 50 W / cm ^{2 to 2} GW / cm ^2. Decolorization method.