JP2004002459A - Primary agent for permanent wave and method of treatment for straight permanent wave to curly hair by using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a primary agent for permanent wave imparting a straight permanent wave which has an excellent straight effect on the curly hair (crimped hair) and its retentivity without impairing the hair. <P>SOLUTION: The primary agent for permanent wave comprises 2-11 wt.% of a reducing agent and 0.2-4 wt.% of dithioglycolic acid diammonium and the agent is used by coating the agent to the crimped hair and then subjecting to a straightening treatment by an iron for hair straightenig at 60-220°C. The agent preferably contains at least one kind selected from the group consisting of a carboxy methylcellulose or its salt or pullulan or its derivative and N-[2-hydroxy-3-[3-(dihydroxymethylsillyl)propoxy]propyl] peptide hydrolyzate. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a first permanent wave permanent agent for straight perm and a method for applying straight perm to curly hair (curly hair) using the first agent.

The straight perm treatment (curly straightening treatment) for straightening the so-called "curly hair" called "curly hair" with a permanent wave agent is performed using a reducing agent consisting of thioglycolic acid or a salt thereof, cysteine or a salt thereof. The first agent for permanent wave, which contains an alkaline agent such as ammonia water, monoethanolamine, ammonium bicarbonate, and, if necessary, further contains a wetting agent, a surfactant, a stabilizer, etc. After applying, the curly hair is straightened (straight), and in this state, the disulfide bond in the hair is reductively cleaved with a reducing agent to generate a mercapto group, and then the second agent is applied, and the curly hair is straightened. Oxidizing the mercapto group with an oxidizing agent to re-form the disulfide group at a position different from the original position It is to the hair straight.
JP-A-7-101840

However, in the case of the straight permanent treatment with the conventional permanent wave agent, the straight effect and its retention are not sufficient, and the hair returns to the original state or returns to a state close to the original state under shampooing or high humidity. There was a problem.

Therefore, the present invention solves the above-mentioned problems in the prior art, and can provide a permanent that has an excellent straightening effect on curly hair and its holding property without damaging the hair. It is intended to provide a first agent for waves.

The present inventors have conducted intensive studies in order to solve the above-mentioned problems, and as a result, the first agent for permanent wave contains 2 to 11% by weight of a reducing agent and 0.2 to 4% by weight of diammonium dithiodiglycolate. After applying the first agent for permanent wave containing 2 to 11% by weight of the reducing agent and 0.2 to 4% by weight of diammonium dithiodiglycolate to the curly hair, the surface temperature becomes 60%. When straightening the above-mentioned curly hair using a hair straightening iron at a temperature of up to 220 ° C., it was found that a straight perm having an excellent straightening effect on curly hair and its holding property can be imparted, and the present invention was completed. I have to do it.

第 The first agent for permanent wave of the present invention can provide a straight perm excellent in a straightening effect and its holding property without damaging the hair.

Although the first agent for permanent wave of the present invention contains a reducing agent, the same reducing agent as that used in the first agent for the permanent wave can be used. Examples thereof include thioglycolic acid salts such as thioglycolic acid and ammonium thioglycolate; cysteine salts such as cysteine and cysteine hydrochloride; cysteine derivatives such as N-acetylcysteine; thioglyceryl alkyl ether; mercaptoalkylamide; Salts, bisulfites and the like. These reducing agents reduce disulfide bonds in keratin constituting hair to generate a mercapto group, and reduce hair with an oxidizing agent contained in the second agent. It is a substrate to be subjected to a straight permanent treatment.

The reducing agents can be used alone or in combination of two or more. The content of the reducing agent in the first agent for permanent wave (the amount of the reducing agent in the first agent for permanent wave) is as follows. It is necessary to be 2 to 11% by weight, particularly preferably 4 to 11% by weight. When the content of the reducing agent in the first agent for permanent wave is less than 2% by weight, the hair cannot be sufficiently subjected to the straight permanent treatment, and the content of the reducing agent in the first agent for permanent wave becomes insufficient. If the content is more than 11% by weight, the hair is damaged, and the gloss and uniform slipperiness of the hair are reduced.

Further, the first agent for permanent wave of the present invention contains diammonium dithiodiglycolate. The diammonium dithiodiglycolate has an action of adjusting the reducing power of the reducing agent. When a thioglycolic acid or a thioglycolate such as ammonium thioglycolate is used as the reducing agent, the effect of adjusting the reducing power of the thioglycolic acid or the thioglycolate by the equilibrium reaction is excellent.

(4) The content of the diammonium dithiodiglycolate in the first agent for permanent wave needs to be 0.2 to 4% by weight, and particularly preferably 0.5 to 4% by weight. If the content of diammonium dithiodiglycolate in the first part for permanent wave is less than 0.2% by weight, the effect of controlling the reducing power of the reducing agent cannot be sufficiently exerted, so that the hair may be damaged. If the hair is glossy and the uniform slip (slip) feeling is reduced, and the content of diammonium dithiodiglycolate in the first agent for permanent wave is more than 4% by weight, the hair can be sufficiently straightened. Processing may not be possible.

第 In addition to the above-mentioned reducing agent and diammonium dithiodiglycolate, the first component for permanent wave of the present invention can contain optional components usually contained in the first component for permanent wave. Such optional components include, for example, ammonium bicarbonate, aqueous ammonia, monoethanolamine, alkaline agents such as potassium hydroxide, anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants Surfactants, carboxymethylcellulose or its salts, pullulan or its derivatives, thickeners such as carrageenan, xanthan gum, various alkylolamides, wetting agents such as propylene glycol, 1,3-butylene glycol, glycerin, paraffin , Fatty acid esters, oils and fats such as animal and vegetable oils, higher alcohols such as cetyl alcohol, stearyl alcohol, oleyl alcohol, and hydrolyzates and derivatives of proteins derived from animals and plants such as collagen, keratin, silk, soy protein, wheat protein, etc. , Hair care agents, preservatives, stabilizers, anti-inflammatory agents, coloring agents, chelating agents, such as perfumes.

The first agent for permanent waving of the present invention is for treating a straightened hair with curly hair, and is different from the one for imparting a wave to straight hair like the first agent for normal permanent waving, The idea of giving a wave to straighten it is also possible for curly hair, and the straightening agent for straightening curly hair is also called a permanent wave agent by those skilled in the art. Also in the invention, it is expressed as the first agent for permanent wave accordingly.

As will be described in detail later, the first agent for a permanent wave of the present invention performs a straightening treatment of hair by using a hair straightening iron having a surface temperature of 60 to 220 ° C. It is preferable that a component that can prevent the hair from being damaged by heat during the aging treatment is contained in the first agent for permanent wave. As such a component, carboxymethylcellulose or a salt thereof is preferable. The carboxymethylcellulose or a salt thereof protects hair from the heat of an iron for hair straightening, imparts viscosity to the first agent for permanent waving, and gives hair On the other hand, it has a conditioning action.

As the carboxymethylcellulose or a salt thereof, for example, an alkali metal salt or an ammonium salt of carboxymethylcellulose having a degree of etherification of 2 or more is particularly preferable, and an average molecular weight of about 100,000 to 200,000 is suitable. As a commercially available product of such a carboxymethyl cellulose salt, for example, it is marketed by Daicel Chemical Industries, Ltd. under the trade name of Ernest Gum FDM.

The content of the carboxymethyl cellulose or a salt thereof in the first agent for permanent wave is preferably 0.1 to 10% by weight, particularly preferably 1 to 5% by weight.

プ ル Further, it is preferable that pullulan or a derivative thereof is contained in the first agent for permanent wave of the present invention. That is, pullulan or a derivative thereof has an action of protecting hair from the heat of a hair straightening iron, imparts viscosity to the first agent for permanent waving, and has a conditioning action on hair.

The pullulan is a 4,4,6-triglycopolysaccharide (4,4,6-triglycopolysaccharide) having maltotrises (three glucose molecules having α-1,4 bonds) regularly and α-1,6 bonds, and starch. Is obtained as a raw material by yeast culture. Commercial products of such pullulan include, for example, products such as pullulan PF-20 (food grade having a molecular weight of about 200,000) and pullulan PI-20 (grade obtained by desalting PF-20) from Hayashibara Shoji Co., Ltd. Marketed under the name. Examples of the pullulan derivatives include, for example, fatty acid esters of pullulan.

The content of this pullulan or a derivative thereof in the first agent for permanent wave is preferably 0.1 to 10% by weight, particularly preferably 0.5 to 5% by weight.

Furthermore, it is preferable that the first agent for permanent wave of the present invention contains an N- [2-hydroxy-3- [3- (dihydroxymethylsilyl) propoxy] propyl] hydrolyzed peptide. The N- [2-hydroxy-3- [3- (dihydroxymethylsilyl) propoxy] propyl] hydrolyzed peptide has an action of protecting hair from the heat of an iron for hair straightening and has a conditioning action on hair. And has a durable and moisture-resistant film-forming action.

Examples of the N- [2-hydroxy-3- [3- (dihydroxymethylsilyl) propoxy] propyl] hydrolyzing peptide include N- [2-hydroxy-3- [3- (dihydroxymethylsilyl) propoxy] propyl ] Hydrolyzed collagen, N- [2-hydroxy-3- [3- (dihydroxymethylsilyl) propoxy] propyl] hydrolyzed keratin, N- [2-hydroxy-3- [3- (dihydroxymethylsilyl) propoxy] propyl Hydrolyzed silk, N- [2-hydroxy-3- [3- (dihydroxymethylsilyl) propoxy] propyl] hydrolyzed casein, N- [2-hydroxy-3- [3- (dihydroxymethylsilyl) propoxy] propyl ] Hydrolyzed wheat protein peptide, N- [2-hydroxy-3- [3- Dihydroxymethylsilyl) propoxy] propyl] hydrolyzed soybean protein peptide, N- [2-hydroxy-3- [3- (dihydroxymethylsilyl) propoxy] propyl] hydrolyzed yeast protein peptide, and especially N- [ 2-Hydroxy-3- [3- (dihydroxymethylsilyl) propoxy] propyl] -hydrolyzed collagen is preferred because of its excellent effect of protecting the hair from the heat of the hair straightening iron.

The N- [2-hydroxy-3- [3- (dihydroxymethylsilyl) propoxy] propyl] hydrolyzed collagen is obtained by adding 3-glycidoxypropylmethyldihydroxysilane to a collagen peptide obtained by hydrolyzing collagen. Commercially available N- [2-hydroxy-3- [3- (dihydroxymethylsilyl) propoxy] propyl] hydrolyzed collagen is a quaternized hydrolyzed collagen. It is marketed by Kasei under the trade name Promois W-52SIG.

The content of the N- [2-hydroxy-3- [3- (dihydroxymethylsilyl) propoxy] propyl] hydrolyzed peptide in the first agent for permanent wave is 0.1 to 10% by weight, particularly 0%. 0.3 to 5% by weight is preferred.

To show an example of straight permanent treatment of the curly hair using the first agent for permanent wave of the present invention, first, apply the first agent for permanent wave of the present invention to the curly hair and leave for 5 to 30 minutes, After being washed with water, it is dried in a state where a part of water remains (preferably 80 to 90% dryness).

縮 Then, in this state (that is, the state where the first agent for permanent wave has penetrated into the tissue of the curly hair), the curly hair is straightened by a hair straightening iron having a surface temperature of 60 to 220 ° C. Then, after the straightening treatment with the hair straightening iron, the mercapto group (mercapto group generated by cleavage of disulfide bond) in the hair is oxidized by the second agent for permanent wave as in the related art to convert the disulfide bond to the original. The hair is regenerated at a position different from the position and the straightened hair is fixed.

The second permanent wave agent used subsequently to the first permanent wave agent of the present invention may be the same as conventional ones, for example, potassium bromate, sodium bromate, sodium perborate and oxidation of hydrogen peroxide. Permanent wave second agent containing 1 to 20% by weight, preferably 2 to 12% by weight of the agent.

The hair straightening iron can be heated to a surface temperature of 60 to 220 ° C., and various types can be used without particular limitation as long as the hair can be straightened. The one shown in FIG. 1 is preferably used. The hair straightening iron shown in FIG. 1 includes a main body 1 having a grip portion 4, a plate portion 6 provided with an electric heater, and a fulcrum portion 5 located between the grip portion 4 and the plate portion 6. A lever portion 15 facing the grip portion 4, a plate portion 17 including an electric heater and facing the plate portion 6 of the main body 1, and a fulcrum portion 16 located between the lever portion 15 and the plate portion 17 are provided. The fulcrum part 16 comprises the holding member 2 rotatably supported by the fulcrum part 5 of the main body 1.

The present applicant has already filed a patent application as Japanese Patent Application No. 10-182800 for the iron for hair straightening. The iron for hair straightening will be described in detail. The fulcrum 5 includes a fulcrum 5 extending downward from a front end of the portion 4 and a plate 6 extending forward from a lower end of the fulcrum 5. Then, as shown in FIG. 2, the main body 1 is formed as two halves 1 a and 1 b divided into right and left, and the halves are joined together to form an integral main body 1. A rectangular recess 7 is provided in the plate portion 6 of the main body 1, and a plate 8 containing a planar heater H is housed in the recess 7 in a state where the plate 8 is exposed. A concave groove 7a is formed in the side wall of the concave portion 7 so that the concave groove 7a is fitted to the protruding ridge 8a on the side surface of the plate 8 so as not to be easily detached.

The fulcrum portion 5 and the grip portion 4 are also hollow inside, and a power cord (not shown) for heating the heater H is passed therethrough, and the grip portion 4 is provided via an ON-OFF switch (not shown). It goes out from the edge. Further, rectangular openings 9, 10 through which the sandwiching member 2 passes are formed from the front surface of the fulcrum portion 5 and the rear surface of the fulcrum portion 5 to the lower portion of the front end of the grip portion 4. A cylindrical bearing 11 for rotatably supporting the sandwiching member 2 and a spring receiver 13 for receiving the upper end of a spring 12 are provided on a side wall inside the fulcrum 5. The spring 12 biases the holding member 2 so that its front end side is always open. Around the plate portion 6, a ridge 14 having a semicircular cross section is provided.

On the other hand, the sandwiching member 2 includes a lever portion 15 which comes below the grip portion 4 of the main body 1 when assembled as shown in FIG. 1, a fulcrum portion 16 extending forward from an upper portion of the front end of the lever portion 15, and a fulcrum portion. 16 and a plate portion 17 extending forward from the front end. The plate portion 17 is manufactured by being divided into right and left parts, and is integrally formed with one half 17 a of the plate portion 17 being connected to the front end of the fulcrum portion 16. Then, the other half 17 b is joined after housing the heater H and the plate 18. The ridge 14 is also provided around the plate portion 17 of the sandwiching member 2.

The rear portion 16b of the fulcrum 16 of the sandwiching member 2 is shifted downward from the front portion 16a. A horizontal hole 21 is formed in a portion 16 b on the rear side of the fulcrum 16. The hole 21 is a portion through which a rotating shaft 22 that rotatably connects the sandwiching member 2 to the main body 1 is passed. A vertical bottomed hole 23 is formed behind the hole 21. This hole 23 is for accommodating and holding the lower part of the spring 12.

レ バ ー The lever 15 of the sandwiching member 2 is bent at the center and the rear end extends obliquely downward. As a result, the ring finger and the little finger can be firmly applied.

フ Flocculation processing (flocking) is applied to the side to surface of the plate portion 16 of the main body 1 and the plate portion 17 of the sandwiching member 2 so as to reduce heat felt when the skin hits the skin. The flocky treatment can be performed by melting the surface of the plate portion with naphtha and planting the nylon pile fibers so as to stand upright. Further, the surfaces of the plates 8 and 18 are subjected to a surface treatment such as Teflon (registered trademark) processing to reduce friction, thereby improving the slip of hair. By performing Teflon (registered trademark) processing, non-adhesion, heat resistance, and corrosion resistance can be improved. Reference numeral 24 in FIG. 1 indicates a pilot lamp indicating that the heater H is energized.

To straighten the hair (or hair bundle) by the hair straightening iron, the hair (or hair bundle) is heated by sandwiching the hair (or hair bundle) between the plate portion 6 of the main body 1 and the plate portion 17 of the sandwiching member 2. Apply pressure.

In the present invention, the surface temperature of the hair straightening iron is set to 60 to 220 ° C., because when the surface temperature of the hair straightening iron is lower than 60 ° C., the hair is too low to sufficiently curl the hair. If the hair cannot be straightened and the surface temperature of the hair straightening iron is higher than 220 ° C., the hair is damaged, and the gloss and uniform smoothness of the hair are reduced.

Next, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to only these examples. In the following examples and the like, the percentages indicating the concentrations of the solution and the dispersion are all by weight.

Examples 1 and 2 and Comparative Example 1
With the compositions shown in Table 1, three types of first agents for permanent waves were prepared. In addition, the numerical value which shows the compounding quantity of each component shown in Table 1 is a weight part. Concentrations of components to be blended that are not pure are shown in parentheses at the end of the component names.

* 1: Ernest Gum FDM (trade name) manufactured by Daicel Chemical Industries, Ltd.
* 2: Pullulan PF-20 (trade name) manufactured by Hayashibara Shoji Co., Ltd.
* 3: Promois W-52SIG (trade name) manufactured by Seiwa Kasei Co., Ltd.
* 4: The balance of the amount of purified water refers to the amount of purified water to make the total amount 100 parts by weight.

As the second agent for permanent wave used in combination with the first agent for permanent wave of Examples 1 and 2 and Comparative Example 1, 10% by weight of sodium bromate and 10% by weight of disodium hydrogen phosphate in purified water were used. A second agent for permanent wave was prepared in which 0% by weight and 0.15% by weight of phosphoric acid (85%) were dissolved.

As the curly hair used for the straight perm treatment, use strong curly hair and make the degree of the curl as uniform as possible. From the above curly hair, measure 12 cm in length (however, measure in a natural state without stretching) ) To prepare a hair bundle having a weight of 0.5 g, and washing with a 50 ml washing solution [5 w / v% polyoxyethylene (9) lauryl ether, 20 mM @ EDTA, pH 4.5] at 33 ° C for 60 minutes per hair bundle. Thereafter, a product which was sufficiently washed with distilled water and dried with a drier was prepared.

Straight perm treatment:
1 ml of the first agent for permanent wave of each of Examples 1-2 and Comparative Example 1 was separately applied to the above-mentioned hair bundle in an amount of 1 ml each, left at 45 ° C. for 15 minutes, washed sufficiently with water, and partially dried with a dryer. After drying to the remaining state, the hair was straightened by pressing three times for 3 seconds with a hair straightening iron set at a surface temperature of 180 ° C. to straighten the curly hair, and then the above-mentioned second agent for permanent wave was applied to the hair bundle. Each 1 ml was applied, left at 35 ° C. for 15 minutes, washed sufficiently with water, dried with a drier to obtain a sample hair bundle, and the straight permanent treatment was completed.

Comparative Example 2
1 ml of the first agent for permanent wave having the same composition as in Example 1 was applied to each hair bundle similar to that of Example 1 described above, and then left at 45 ° C. for 15 minutes, thoroughly washed with water, and then used for the permanent wave. After applying 1 ml of the second agent and leaving it to stand at 35 ° C. for 15 minutes, it was sufficiently washed with water and dried with a dryer to obtain a sample hair bundle, and the straight permanent treatment was completed.

As shown in the above Examples 1 and 2 and Comparative Examples 1 and 2, the hair straightness and straightness retention, hair elongation, elongation retention, gloss and uniform slip (slip) ) The feeling was examined and the tensile strength of the hair was measured. Furthermore, a hair bundle having a length of 12 cm and a weight of 0.5 g was made with straight hair, and the same treatment as that of the straight perm treatment of the above Examples 1-2 and Comparative Examples 1-2 was carried out to obtain a sample hair bundle. The shrinkage of the hair was measured. The evaluation method and the evaluation result will be described in detail below.

(1) Measurement of Straightness and Straightness Retention of Hair One end of a sample hair bundle subjected to straight perm treatment in Examples 1 and 2 and Comparative Examples 1 and 2 was fixed to a panel and suspended, and the total length was measured. The straight ratio was calculated by the following equation.

AB
Straight rate (%) = ────── × 100
CB
A: Total length of hair bundle after straight perm treatment (mm)
B: Total length (mm) of the hair bundle before straight perm treatment in the natural state (that is, in a state with crimping)
C: Total length (mm) of the hair bundle before straight perm treatment straightened

Next, the hair bundle after the above straight perm treatment was immersed in a 5% sodium lauryl sulfate aqueous solution once a day for 5 minutes, washed with water, and dried.

After repeating the washing treatment with the aqueous solution of sodium lauryl sulfate for 30 days, the straightness ratio was examined in the same manner as described above, and the straightness ratio immediately after the straight permanent treatment was used to determine the straightness retention ratio by the following equation.

Straight rate after 30 days Straight holding rate (%) = $ 100
Straight rate immediately after processing

Table 2 shows the results of the straight ratio and the straight holding ratio.

(2) Elongation of Hair, Elongation Retention, Gloss and Uniform Sliding (Slip) Feeling Elongation and Elongation Retention of Sample Hair Bundles Straight-Permed in Examples 1-2 and Comparative Examples 1-2 (Evaluation based on elongation after 3 months), and gloss and uniform smoothness were sensory evaluated. Table 3 shows the results. However, in displaying the evaluation results in Table 3, the evaluation results are represented by symbols according to the following criteria.
A: Very good.
〇: Good.
Δ: slightly bad.
×: Bad.

(3) Measurement of Tensile Strength of Hair Ten hairs were collected from each of the sample hair bundles subjected to the straight perm treatment in Examples 1 and 2 and Comparative Examples 1 and 2, and both ends of 5 cm and 6 cm from the hair tips were 1 cm. It was stopped with a glass fiber-containing tape having a width so that breakage could occur between a portion 5 cm and a portion 6 cm from the tip of the hair, and the major axis and minor axis of the hair were measured with a micrometer. After immersing this sample in distilled water for one day, the weight at break was measured using a rheometer, and the tensile strength of the hair was determined by the following equation. Table 4 shows the results.

D × 4
Tensile strength of hair (g / μm ² ) = ────────── × 100
E × F × 3.14
D: Breaking weight (g)
E: long diameter of hair (μm)
F: short diameter of hair (μm)

(4) Measurement of Hair Shrinkage Rate One end of a sample hair bundle obtained by treating a hair bundle made of straight hair in the same manner as the straight permanent treatment of Examples 1-2 and Comparative Examples 1-2 was fixed to a panel. Hanging, the total length was measured, and the shrinkage of the hair was determined by the following equation. Table 5 shows the results.

GH
Hair shrinkage (%) = ─────── × 100
G
G: Total length (mm) of hair bundle before treatment
H: Overall length (mm) of hair bundle after treatment

測定 The measurement results and evaluation results as described above are shown in Tables 2 to 5, and depending on the tables, the measurement results and evaluation results for untreated hair are also shown as needed.

As is clear from the results shown in Tables 2 and 4, Examples 1 and 2 have a high straightness ratio and a high straightness retention ratio, and have excellent gloss and uniform smoothness of the hair after the straight permanent treatment, and have high tensile strength. Had.

Comparing Examples 1 and 2 with Comparative Example 1 in which a straight perm treatment was similarly performed using a hair straightening iron, Examples 1 and 2 are comparable to Comparative Example 1 with respect to the straight ratio and the straight holding ratio. However, compared to Comparative Example 1, the hair after the straight perm treatment was excellent in gloss, uniform slipperiness, and had a high tensile strength, indicating that the hair was less damaged by the straight perm treatment.

In addition, when Examples 1 and 2 are compared with Comparative Example 2 in which a straight permanent treatment is performed without using a hair straightening iron, Examples 1 and 2 have much higher straight ratios and straight retention rates than Comparative Example 2. Was excellent.

The hair shrinkage percentages shown in Table 5 theoretically demonstrate that according to the present invention, it is possible to impart a straight permanent having an excellent straightening effect on curly hair and its retention without damaging the hair. Although this is a material, it will be described. First, in Comparative Example 2 in which the hair straightening iron was not used, the shrinkage ratio was lower than in Examples 1 and 2 and Comparative Example 1 in which the hair straightening iron was used. Is very small. This indicates that, in Comparative Example 2 in which the hair straightening iron was not used, the straight perm treatment was performed only on the surface of the hair, and the straight perm treatment was not widespread in the hair structure. From the opposite side, in Examples 1 and 2 and Comparative Example 1 using the hair straightening iron, it is shown that the straight permanent treatment extends to the inside of the hair structure. The contraction rate of the hair shown in Table 5 does not indicate that the hair has apparently contracted due to the waving of the hair, but indicates the rate of contraction in a straight state.

Then, when Examples 1 and 2 using the hair straightening iron and Comparative Example 1 are similarly compared, Comparative Example 1 has a larger shrinkage ratio than Examples 1 and 2. This is considered to indicate that the reduction of the hair into the tissue was excessive in Comparative Example 1, and as a result, the tensile strength of the hair was reduced as shown in Table 4, and As shown, the gloss of the hair and the uniform smoothness are poor.

On the other hand, in Examples 1 and 2, although the shrinkage rate of the hair stayed within 8.4% and 7.4%, that is, within 10%, and the reducing action reached the inside of the hair tissue, The reduction is not excessive, and as a result, a high straight ratio and a straight holding ratio are obtained as shown in Table 2, but as shown in Tables 3 and 4, the tensile strength of the hair after the straight permanent treatment is high. Excellent hair gloss and uniform smoothness. According to the study of the present inventor, it has been found that the shrinkage ratio of the hair is suitably in the range of 5 to 10%.

、 Also, when compared between Examples 1 and 2, Example 2 is superior to Example 1 in the gloss of hair and the uniform smoothness. This is because carboxymethyl cellulose, pullulan, N- [2-hydroxy-3- [3- (dihydroxymethylsilyl) propoxy] propyl] hydrolyzed collagen and the like contained in the first agent for permanent wave of Example 2 are hair straighteners. It is considered that the hair was protected from the heat of the hair straightening iron in the straightening treatment using the iron for hair.

It is a perspective view which shows typically an example of the iron for hair straights used when performing a straight permanent process using the 1st agent for permanent waves of this invention. It is a perspective view before assembling of the iron for hair straights shown in FIG.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Main body 2 Nipping member 4 Grip part 5 Support part 6 Plate part 7 Concavity H heater 8 Plate 12 Spring 13 Spring receiver 14 Protrusion 15 Lever part 16 Support part 17 Plate part 18 Plate 21 Hole 22 Rotating shaft 23 Hole

Claims (2)

It contains 2-11% by weight of a reducing agent and 0.2-4% by weight of diammonium dithiodiglycolate, and is applied to curly hair and then straightened with a hair straightening iron having a surface temperature of 60-220 ° C. A first agent for a permanent wave, which is used. A hair straightener having a surface temperature of 60 to 220 ° C. after applying the first agent for permanent wave according to claim 1 to the curly hair, leaving the hair to stand for 5 to 30 minutes, washing with water, and drying in a state where a part of moisture remains. A straightening treatment for the curly hair, wherein the curly hair is straightened using an iron for ironing.

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