JP2011088878A - Curly hair straightening method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optimal curly hair straightening method in which a curly hair straightening effect continues more effectively, and it is also possible to control fall of hair strength in a curly hair straightening treatment process. <P>SOLUTION: The curly hair straightening method includes the following steps (1)-(3): (1) a reduction step for hair by coating a first agent; (2) a heat treatment step for hair; and (3) an oxidation step for hair by coating a second agent. The curly hair straightening method is characterized in that the heat treatment temperature of (2) the heat treatment step for hair is made 175-220°C. Thus, it is found that the curly hair straightening effect in hair is made more continuous, and the fall of hair strength in the curly hair straightening treatment process can be also controlled. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention is an invention in the field relating to a cosmetic method for hair, and more specifically, an invention relating to a method for correcting curly hair.

  Permanent wave agents are known not only for the purpose of forming waves on hair, but also for straight permanent agents (curly hair straighteners) for straightening eyelashes. Straight perm agents are used to positively return the waved hair to the original state due to past treatments, straighten the eyelashes inherent to it, or make it straight hair It is used for treatment purposes in beauty salons, beauty salons, hair salons, and the like.

  The correction of curly hair tends to be performed based on the intuition and experience of the practitioner, and the skill of the practitioner tends to appear as a big difference in the ability to correct or not. Further, when straightening hair, the hair strength is lowered and the hair is easily painful. Therefore, an object of the present invention is to provide an optimal method for correcting curly hair, in which the effect of straightening hair can be more effectively maintained and the reduction in hair strength can be suppressed.

The difference between straight hair without undulation (straight hair) and wavy hair (curly hair) can be explained by macro differences such as whether the shape of the hair is a perfect circle or an ellipse. In general, the present inventors have focused on the microscopic viewpoint of hair, and the orientation of microfibrils (from the diffraction image obtained when microbeam X-rays are irradiated on the hair sectioned in a cross section ( We have searched for the difference in periodicity. As a result, with straight hair, diffraction images appear in all directions and microfibril periodicity exists in any direction. With curly hair, diffraction images appear in only one direction, and microfibril periodicity exists in one direction. I found out.

  In addition, in the straightening treatment for curly hair, the present inventors consider that it is an important factor not only to treat the appearance straight but also to change the microfibril periodicity of the hair. As a result, it was determined that the step that can change the periodic structure of the microfibrils most in the step of straightening the curly hair is a heat treatment step, and the optimum conditions for straightening the curly hair were further examined. As a result, it was found that by setting the heat treatment temperature to 175 ° C. or higher, the α-crystals of microfibrils were once melted, and the subsequent hair straightening effect was improved, and the present invention was completed.

That is, the present invention includes the following steps (1) to (3):
(1) Hair reduction step by applying the first agent,
(2) a heat treatment step for the hair;
(3) In the hair curly straightening method including the hair oxidation step by application of the second agent, (2) the hair curling straightening method (hereinafter, The present invention also provides a method for correcting curly hair of the present invention.

In addition, (1) the hair reduction step by application of the first agent is application of thiolactic acid or a salt thereof (hereinafter also referred to as thiolactic acid), so that the hair damage suppressing effect and hair damage suppressing effect can be obtained. It is recognized and is the optimal mode of the present hair straightening method of the present invention.

  According to the present invention, there is provided a method for straightening hair that can perform hair straightening very effectively.

It is drawing which shows the result of having examined the hair straightening effect in each step of the hair straightening method of this invention using the half value width change rate as a parameter | index. It is drawing which shows the result of having examined the conditions of the heat processing in the hair straightening method of this invention. It is drawing which shows the result of having examined the result by the kind of reducing agent in the curly hair straightening method of this invention. It is drawing which shows the result of having examined the influence which it has on the hair strength of the kind of reducing agent in the curly hair straightening method of this invention.

As described above, the hair straightening method of the present invention is a hair straightening method on the premise that the following steps (1) to (3) are included.
(1) Hair reduction step by applying the first agent,
(2) a heat treatment step for the hair;
(3) Hair oxidation step by applying the second agent

These steps are described below in connection with the features of the present invention.
[First step]
The first step (1) is a hair reduction step by applying a first agent containing a reducing agent. The first step breaks the disulfide bond in the hair. As the reducing agent, thiolactic acid, thioglycolic acid, dithioglycolic acid, or a salt thereof (ammonium salt, monoethanolamine salt, etc.), cysteine, a cysteine derivative, cysteamine, or a salt thereof, or the like Two or more types are exemplified. As described above, among these, thiolactic acid or a salt thereof is most preferable. In the first agent, as other compounding components, for example, alkaline agents such as ammonia, organic amines, ammonium salts, basic amino acids, monoethanolamine, etc .; surfactants such as nonionic surfactants and cationic surfactants Agents: Stabilizers such as edetate, etc., oils, polyhydric alcohols, water, etc. The blending amount of the reducing agent in the first agent is not particularly limited according to the first agent of the known permanent wave agent. The contact time between the hair and the first agent is usually about 10 to 30 minutes.

[Second step]
The second step (2) is a heat treatment step of the hair, and in the first step, the heat treatment is performed on the hair having a broken disulfide bond to melt the α-crystals of the microfibrils in the hair. . This step is a step necessary for exhibiting the excellent hair straightening effect of the present invention. In order to melt the α-crystals of the microfibrils of the hair, it is necessary to heat the hair at 175 ° C. or higher. Moreover, the upper limit of heating temperature is 220 degreeC. When the heating temperature exceeds 220 ° C., the hair is burnt, which is not preferable. Moreover, a suitable heating temperature range is 175-200 degreeC, Most preferably, it is 175-185 degreeC. Moreover, the heating means of hair is normally adjusted by adjusting the temperature of the hair iron, and the heating time is about 2 to 5 seconds as the total time during which the hair iron is in contact with the hair. It is preferable to use it as a guide. This second step can be performed only once (cycle), but can also be performed two to three times (cycle). However, the hair strength tends to decrease by repeatedly performing the heat treatment step of the hair.

[Third step]
The third step (3) is a step for forming a new disulfide bond and fixing the straight hair state by oxidizing the hair with the second agent containing the oxidizing agent. The second agent has the same structure as the second agent of the permanent wave agent currently used. Examples of the oxidizing agent include potassium bromate, sodium bromate, sodium perborate, hydrogen peroxide, and the like. Can be mentioned. In addition to water, a pH buffering agent, a silicone emulsion, or the like can be contained as appropriate. The blending amount of the oxidizing agent in the second agent is not particularly limited according to the second agent of the known permanent wave agent. The contact time between the hair and the second agent is usually about 3 to 20 minutes.

  The hair straightening method of the present invention includes the steps (1) to (3) described above, but other steps can be appropriately included. For example, after performing the hair reduction step of the first step, it is possible and beneficial to perform the hair heating step of the second step after the hair washing (water washing) and the drying step by a drier or the like. . It is also possible and beneficial to perform a hair washing (water washing) and a drying step using a dryer after the third hair oxidation step.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples of the present invention, but this does not limit the scope of the present invention.

  In this example, microbeam X-rays are irradiated on the cross-section of hair that has undergone straightening treatment under various conditions, changes in the fiber structure are observed, and half of the peak appearing in the intensity profile in the azimuth direction 360 ° is observed. We searched for important factors that change the periodic structure of microfibrils from changes in the price range. The contents and results will be described below.

[ Examination of the effect of straightening method ]
After sampling the root of wavy Japanese hair before treatment and performing the hair straightening treatment on each condition on the remaining part, cut the cross section of the hair before treatment and after treatment into 30 μm with a microtome, and sample It was. The cross section of this sample was irradiated with microbeam X-rays from the vertical direction at intervals of 20 μm. The orientation of the microfibril structure was analyzed by determining the half-value width of each peak from the intensity profile in the azimuth direction of 360 ° of the obtained diffraction image. That is, when the intensity peak becomes broad (uniform tendency, that is, straight hair tendency), the full width at half maximum increases. Therefore, the index of “half width change rate = average half width after treatment / average half width before treatment” is reduced. The structural change inside the hair due to hair straightening was used as an index. If the half-value width change rate is greater than 1, it indicates that the hair has been corrected to straight hair by the curly hair straightening process, and the greater the value, the greater the degree of correction. On the contrary, if the half-value width change rate is smaller than 1, it indicates that although the curly hair straightening process was performed, the eyelash tendency was promoted.

After 15 minutes treatment with curly hair straightener / first hair straightener, rinse with running water.
・ Heat treatment: Using curling iron for straightening hair 100 ℃, 140 ℃, 160 ℃, 180 ℃, 3 seconds each ・ 1
Cycle.
・ Second hair straightener 2 After 5 minutes treatment, rinse with running water.

<Prescription of the first agent>
10.5% by mass of ammonium thiolactate or monoammonium thioglycolate
Diammonium dithiodiglycolate 4.0% by mass
Monoethanolamine 2.0% by mass
Diethylenetriaminepentaacetic acid pentasodium solution Suitable amount Purified water Residual

<Prescription of the second agent>
Hydrogen peroxide 1.5% by mass
Diethylenetriaminepentaacetic acid pentasodium solution Appropriate amount Phosphoric acid Appropriate amount Disodium hydrogen phosphate Appropriate amount Purified water Residue

Results (1) For wavy hair with orientation in microfibrils, it was shown that the orientation decreased due to straightening treatment. (Not shown)

(2) First agent treatment (reduction), first agent treatment and heat treatment (reduction / heat), first agent treatment, heat treatment and second agent treatment (reduction, heat / oxidation), first agent treatment and second agent In the treatment (reduction / oxidation: no heat treatment) and heat treatment only (heat only) systems, the half-width change rate was examined using ammonium thiolactate as the reducing agent in the first agent (FIG. 1).

  From this result, it became clear that the half width decreased in the reduction treatment with the first agent, resulting in a more biased structure, and the internal structure of the hair changed greatly by the heat treatment following the reduction treatment, and the straight hair tendency It is shown that it became. Further, it is considered that the hair structure changed by the heat treatment is retained by the oxidation treatment with the second agent. It has also become clear that the heat treatment alone has a rather uneven structure on the hair.

(3) In the system of the first agent treatment, heat treatment and second agent treatment (reduction / heat / oxidation) using ammonium thiolactate as the reducing agent in the first agent, the heat treatment temperatures are 100 ° C., 140 ° C., 160 The half-width change rate was examined as ℃ and 180 ℃ (Fig. 2).

  From this result, it was shown that the curly hair straightening effect is exhibited most effectively by the hair iron treatment at 180 ° C.

  That is, all the hair treated at each treatment temperature looks straight on the appearance, but by treating under specific conditions defined in the present invention, the internal structure of the hair is closer to straight hair, It became clear from the data of half width above. Thereby, it is thought that the curly hair straightening effect in the hair processed by the curly hair straightening method of this invention is excellent in sustainability compared with the hair performed on other conditions.

(4) The effect which appears in the hair straightening effect when ammonium thiolactate (TLA) was used as the reducing agent in the first agent and when monoammonium thioglycolate (TGA) was used was examined. In addition, the heat processing temperature was performed at 180 degreeC, and the oxidation process by the 2nd agent was performed after that (FIG. 3).

  From this result, it has been clarified that the use of thiolactic acid is superior in curly hair straightening effect compared to thioglycolic acid.

[ Effect of reducing agent on hair strength ]
Japanese hair with waviness was sampled, and a series of curly hair straightening steps were performed. That is, as a reducing agent in the first agent, (1) monoammonium thioglycolate (TG: 9.5%) and dithioglycolic acid (DTDG: 3.0%), (2) ammonium thiolactate (TL: 9. 5%), (3) ammonium thiolactate (TL: 9.5%) and dithioglycolate diammonium (DTDG: 3.0%). The oxidation process with the second agent containing 5% hydrogen peroxide at 180 ° C. for 3 seconds was performed 3 times, and the influence on hair strength was examined. Hair strength was measured with a precision universal tester Autograph AGS-H 50N (manufactured by Shimadzu Corporation). The results are shown in FIG. In FIG. 4, the initial hair strength is 1, and the vertical axis represents relative hair strength. In principle, the greater the number of heat treatments, the lower the hair strength. In this test, however, the effect of changing the type of reducing agent on the hair strength was examined. It was.

  From the results shown in FIG. 4, the system using ammonium thiolactate as the reducing agent is less likely to lose hair strength due to the number of heat treatments than the system using monoammonium thioglycolate. It has been clarified that the hair can be thoroughly protected by using the hair straightening method.

Claims (5)

Steps (1) to (3) below:
(1) Hair reduction step by applying the first agent,
(2) a heat treatment step for the hair;
(3) In the method for straightening hair, including the hair oxidation step by application of the second agent, (2) the method for straightening hair by setting the heat treatment temperature in the heat treatment step for hair to 175 to 220 ° C. In the said hair curly straightening method, (2) The heat processing temperature of the heat processing step of hair is 175-200 degreeC, The curly hair straightening method of Claim 1 characterized by the above-mentioned. In the said hair curly straightening method, (2) The heat processing temperature of the heat processing step of hair is 175-185 degreeC, The hair curly correction method of Claim 1 characterized by the above-mentioned. In the said hair curly straightening method, (2) The heat processing step of hair is performed by the hair iron, The hair curly straightening method in any one of Claims 1-3. The hair curling straightening method according to any one of claims 1 to 4, wherein (1) the hair reduction step by applying the first agent is performed by applying thiolactic acid or a salt thereof. Method.

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