JPH05112436A - Aqueous solution of permanent wave pretreatment - Google Patents

Abstract

PURPOSE:To obtain an aqueous solution of pretreatment for controlling permanent wave formation ability and preventing damage of hair by coating hair with the aqueous solution before permanent wave treatment. CONSTITUTION:An aqueous solution of pretreatment comprising 0.5-30wt.%, preferably 2-7wt.% dithioglycolic acid or its salt (preferably diammonium salt). By blending the aqueous solution with 0.5-50wt.%, especially 0.5-10wt.% various kinds of surfactants, permeation of the active ingredient into hair is promoted, unmform and desmred wave can simply be provided by pretreatment with a small amount of the aqueous solution in a short time. Hair treated with the pretreating agent forms uniform wave from the root to the tip even if the tip of the hair is excessively damaged, can maintain the waved shape for a long period of time and has hair protecting effects.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a permanent wave pretreatment agent, and more particularly to a permanent wave treatment agent which is applied to hair prior to permanent wave treatment to adjust the ability of forming permanent wave and prevent hair damage. Regarding

[0002]

2. Description of the Related Art Permanent wave treatment is used as the most common method for setting hair to a desired shape over a long period of time. Permanent wave treatment usually cleaves cystine bonds in the hair with a first liquid containing a reducing substance such as thioglycolate or cysteine or an alkaline agent, swells and softens the hair, and then the hair is treated with a rod. Hair that is wrapped around or set in a desired shape with a comb or the like, and then fixes the desired shape by reforming the cystine bond with a second liquid containing an oxidizing agent such as bromate or hydrogen peroxide. It is a processing method. By the way, hair is combed and blown everyday,
In addition, shampoo, permanent wave, hair dye,
Due to bleaching and other treatments, cuticles and weakening of the hair structure have been physically and chemically damaged, and even a single hair becomes the tip that is frequently exposed to these operations. Therefore, the degree of damage is usually higher than that at the root to middle portion. The damaged part has its structure destroyed compared to the healthy part,
For example, it is easy for chemicals such as reducing agents and alkaline agents to penetrate,
It is very susceptible to that effect. That is, when such a hair is subjected to a permanent wave treatment to form a wave, excessive cystine bond cleavage and swelling occur in a damaged portion that is excessively affected by the action of the first liquid, resulting in excessive wave formation and shrinkage. As a result, the desired wave cannot be obtained. In addition, the elution of proteins and lipids that maintain the structure of the hair causes a significant decrease in the elasticity of the hair, resulting in the disadvantage that the wave is not retained for a long time.

In order to prevent damage to the hair caused by such permanent wave treatment, prior to the permanent wave treatment, for example, methylpolysiloxane, paraffin, or a protein component (such as protein) is added to supplement the oil lost by elution. Hydrolyzate)
A method has been proposed for softening the excessive reducing action of the first agent on the damaged part by supplementing the above or by applying a compound having a high adsorbing action to the hair (JP-A-55-1).
11412, JP-A-56-103106, JP-A-5
No. 8-39612, JP-A-60-116623, JP-A-60-243010, and JP-B-63-502104.
JP-A 64-2603, JP-A-2-78607
issue). However, although these pretreatment agents are effective for mild damage, they have been treated with permanent waves and hair coloring several times, especially the tip of hair that has grown to a length of several tens of centimeters. However, the effect is not sufficient. Also, as another way of thinking,
Since the reduction of hair by a reducing agent occurs in an equilibrium reaction with cystine bonds in the hair, the first wave of the permanent wave treatment contains a disulfide compound which is an oxidant of a thiol compound such as thioglycolic acid, and the law of mass conservation Has also been devised to prevent the reduction equilibrium from proceeding too much in the direction of cleavage of the cystine bond (Japanese Patent Publication No. 45-15).
397, US3840656, JP-A-63-2552.
15, EP 0346453, DE 3707415).
However, in this method, the permeation of dithiodiglycolic acid or a salt thereof into hair is generally insufficient as compared with the permeation of a reducing agent such as thioglycolic acid, and especially when the tip of the hair is excessively damaged. Cannot obtain a sufficient reduction suppressing effect. Further, when the content of dithiodiglycolic acid or a salt thereof is increased in order to enhance the reduction inhibitory effect, the reduction inhibitory effect extends not only to the damaged part but also to the healthy part, so that the obtained wave becomes very gentle. I will end up. To take this idea a step further, a method of impregnating an end wrap with a disulfide compound has been proposed (US
4600028). Here, the end wraps sandwich the tip of the hair divided into hair bundles when the hair is wrapped around a rod or the like, and are made of paper or urethane. That is, in general, only the tip of hair that is severely damaged is wrapped with an end wrap impregnated with a disulfide compound, so as to suppress the reducing action, as in the case where the disulfide compound is contained in the first permanent wave treatment liquid. To do. However, in this method, the reduction effect is suppressed only in the part of the hair contained in the end wrap, which is in contact with the end wrap, and the effect is not sufficient. It causes unevenness of the wave in the included part,
It is very inconvenient. In addition, this method cannot be used for treatments that do not use end wraps such as straight perms.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to easily adjust the wave forming ability according to the degree and range of damage when performing permanent wave treatment on damaged hair, and to adjust the wave forming ability from the root to the tip. (EN) A method for obtaining a desired wave evenly, and a hair treatment agent used therefor.

[0005]

In view of such circumstances, the present inventor has conducted various studies, and as a result, prior to the permanent wave treatment, if the hair is treated with an aqueous liquid containing dithiodiglycolic acid or a salt thereof, the subsequent permanent treatment. We have found that damage to hair due to wave treatment can be prevented and that uniform wave application from the root to the tip can be applied, and the present invention has been completed.

That is, the present invention provides an aqueous liquid for permanent wave pretreatment characterized by containing dithiodiglycolic acid or a salt thereof in an amount of 0.5 to 30% by weight (hereinafter referred to simply as%). .. Further, the present invention is a method for imparting a permanent wave to hair, which is characterized by performing a permanent wave treatment after treating the hair with the aqueous solution for the permanent wave pretreatment (hereinafter, also simply referred to as a pretreatment agent). Is provided.

The dithiodiglycolic acid used in the present invention is
It is represented by the following formula. The HOOC-CH ₂ salt of -S-S-CH ₂ -COOH dithiodiglycolic acid, sodium di-alkali metal salts such as dipotassium, di monoethanolamine, di-diethanolamine, ethanolamine salts such ditriethanolamine salt and Examples thereof include a diammonium salt, and a diammonium salt represented by the following formula is preferable.

[0008]

[Chemical 1]

Further, diammonium dithiodiglycolate is specifically manufactured by, for example, Oriental Chemical Co.,
The diammonium dithiodiglycolate solution (40%) is mentioned as easily available. The content of dithiodiglycolic acid or a salt thereof in the pretreatment aqueous solution of the present invention is 0.5 to 30%, preferably 2 to 7%. If this amount is less than 0.5%, the waves due to the permanent wave treatment performed thereafter will not be uniformly applied, and if it exceeds 30%, the waviness will be suppressed too much, which is not preferable.

The pretreatment agent of the present invention is in the form of an aqueous liquid. Here, the aqueous liquid means a liquid liquid in which water is used as a solvent for dithiodiglycolic acid or a salt thereof,
As long as it is in a liquid state, it may include any of an aqueous solution, an emulsion and a paste.

The pretreatment liquid of the present invention is further mixed with various surfactants to promote the permeation of dithiodiglycolic acid or its salt into the hair, and can be uniformly treated in a short time with a small amount of pretreatment. It is also possible to give a desired wave. Examples of the surfactant used here include a cationic surfactant, a nonionic surfactant, an anionic surfactant and an amphoteric surfactant.

Examples of the cationic surfactant include quaternary ammonium salts represented by the following general formula (1) or (2).

[0013]

[Chemical 2]

[Wherein at least one of R ¹ , R ² , R ³ and R ⁴ is substituted with an alkoxy, alkenyloxy, alkanoylamino or alkenoylamino group having a total carbon number of 8 to 28] Is an alkyl or alkenyl group, and the remainder is a benzyl group, an alkyl group having 1 to 5 carbon atoms or a hydroxyalkyl group. R ⁵ has 2 to 2 carbon atoms
3 represents an alkylene group, X ⁻ represents a halogen ion or an organic anion, and n represents an integer of 1 to 20.

Among such cationic surfactants, the quaternary ammonium salt of the general formula (1) is preferable, and the preferable one of the general formula (1) is, for example, the following general formula (3).
Examples include branched quaternary ammonium salts represented by (5).

[0016]

[Chemical 3]

The branched quaternary ammonium salt represented by the general formula (3) is usually synthesized, for example, from an oxo alcohol having 8 to 16 carbon atoms as a raw material, and examples thereof include alkyl derived from oxo alcohol. Examples thereof include a dialkyldimethylammonium salt having a group, a dialkylmethylhydroxyethylammonium salt, and a dialkylmethylbenzylammonium salt. In the present invention,
The branching rate of R ^{6 in} the formula (3) is usually 10 to 100%, and particularly preferably 10 to 50%. Further, those having a total carbon number of R ⁶ of 8 to 16 are used, but those having a constant distribution are preferable, and those having the distribution shown below are particularly preferable. C ₈ ~C _11: 5% or less _{C 12: 10~35% C 13:} 15~40% C 14: 20~45% C 15: 5~30% C 16: 5% or less such branched quaternary ammonium Specific examples of the salt include dialkyldimethylammonium chloride having an alkyl group having 8 to 16 carbon atoms and a branching rate of 10 to 50%.

Further, the fourth branch represented by the general formula (4)
The primary ammonium salt is usually a Guerbet alcohol having 8 to 28 carbon atoms.

[0019]

[Chemical 4]

It is synthesized using as a raw material. Preferable examples of the branched quaternary ammonium salt include alkyl trimethyl ammonium salt having an alkyl group derived from Guerbet alcohol, alkyl dimethyl benzyl ammonium salt, dialkyl dimethyl ammonium salt,
Examples thereof include dialkylmethylhydroxyethylammonium salt and dialkylmethylbenzylammonium salt. Furthermore, among these, particularly preferred specific examples are:
Examples thereof include 2-decyltetradecyltrimethylammonium chloride, 2-dodecylhexadecyltrimethylammonium chloride, di-2-hexyldecyldimethylammonium chloride and di-2-octyldodecyldimethylammonium chloride. General formula (5)
The methyl-branched quaternary ammonium salt represented by
A suitable example is one in which the sum of 15 is 15. Further, the general formulas (1), (2), (3), (4) and (5)
X which is a counter ion of the quaternary ammonium salt represented by
^- Specific examples of chlorine, iodine, halogen such as bromine ion: methosulfate, ethosulfate, methemoglobin phosphate, and organic anions such as ethoxy phosphate.

As the nonionic surfactant, fatty acid monoglyceride, polyoxyethylene alkyl ether,
Examples thereof include lanolin derivatives, polyoxyethylene sorbitol ether, polyoxyethylene polyoxypropylene pentaerythritol, polyoxyethylene polyoxypropylene glycol ether, fatty acid polyoxyalkylene sorbitan, higher fatty acid alkanolamides and ethers of higher alcohols and sugars.

Examples of the anionic surfactant include the following (1) to (11). (1) A linear or branched alkylbenzene sulfonate having an alkyl group having an average carbon number of 10 to 16. (2) Having a linear or branched alkyl group or alkenyl group having an average carbon number of 10 to 20 and having an average of 0.5 to 1 in one molecule.
8 mol of ethylene oxide, propylene oxide,
Butylene oxide, or ethylene oxide and propylene oxide at a ratio of 0.1 / 9.9 to 9.9 / 0.1, or ethylene oxide and butylene oxide at 0.1 / 9.9 to 9.9 / 0. Alkyl or alkenyl ether sulfate added in a ratio of 1. (3) An alkyl or alkenyl sulfate having an alkyl group or an alkenyl group having an average carbon number of 10 to 20. (4) An olefin sulfonate having an average of 10 to 20 carbon atoms in one molecule. (5) An alkanesulfonate having an average of 10 to 20 carbon atoms in one molecule. (6) A saturated or unsaturated fatty acid salt having an average of 10 to 24 carbon atoms in one molecule. (7) It has an alkyl group or an alkenyl group having an average carbon number of 10 to 20, and has an average of 0.5 to 8 moles of ethylene oxide, propylene oxide, butylene oxide, or ethylene oxide and propylene oxide in one molecule. /9.9 to 9.9 / 0.1, or 0.1 / 9.9 of ethylene oxide and butylene oxide.
Alkyl or alkenyl ether carboxylates added in a ratio of ˜9.9 / 0.1. (8) An α-sulfone fatty acid salt or ester having an alkyl group or an alkenyl group having an average of 10 to 20 carbon atoms. (9) An N-acyl amino acid type surfactant having an acyl group having 8 to 24 carbon atoms and a free carboxylic acid residue. (10) A phosphoric acid mono- or diester type surfactant having an alkyl group or an alkenyl group having 8 to 24 carbon atoms. (11) A sulfosuccinic acid ester such as a higher alcohol having 8 to 22 carbon atoms or its ethoxylate, or a sulfosuccinic acid ester derived from a higher fatty acid amide.

Examples of the amphoteric surfactant include (1)
2) and (13) are mentioned. (12) An α-position addition type, secondary amide or tertiary amide type imidazoline-based amphoteric surfactant having an alkyl group, an alkenyl group or an acyl group having 8 to 24 carbon atoms. (13) Carbobetaine-based, amidobetaine-based, sulfobetaine-based, hydroxysulfobetaine-based, or amidosulfobetaine-based amphoteric surfactants having an alkyl group, an alkenyl group, or an acyl group having 8 to 24 carbon atoms.

As the counterion of the anionic residue of these surfactants, alkali metal ions such as sodium and potassium, alkaline earth metal ions such as calcium and magnesium, ammonium ion, and alkanol groups having 2 or 3 carbon atoms. 1 to 3 alkanolamines (for example, monoethanolamine, diethanolamine, triethanolamine, triisopropanolamine, etc.)
Can be mentioned. Examples of the counter ion of the cationic residue include halogen ions such as chlorine, bromine and iodine, and methosulfate and saccharinate ions.

In the pretreatment agent of the present invention, the above-mentioned surfactants may be blended alone or in admixture of two or more, and the blending amount of these surfactants is 0.05 to 50%. Especially 0.
5 to 10% is preferable.

The pretreatment agent of the present invention includes oils and fats such as hydrocarbons, liquid paraffin, waxes, lanolin derivatives, olive oil, hydrogenated castor oil and esters; cationic copolymers, nonionic copolymers and anions. Polymers such as ionic copolymers and nonionic copolymers; silicone derivatives; alkyl polyalkylene glycol ethers; keratin hydrolysates, collagen hydrolysates, elastin hydrolysates, animal protein hydrolysates such as casein A wheat protein hydrolyzate such as gluazine or gluten or a vegetable protein hydrolyzate such as soybean protein hydrolyzate may also be contained.

In the present invention, the pH of the aqueous liquid is not limited, but it is preferably in the range of 2-11.
As the pH adjusting agent at that time, as an acidic substance, hydrochloric acid, phosphoric acid, citric acid, malic acid, succinic acid, lactic acid, etc., as a basic substance, sodium hydroxide, monoethanolamine, diethanolamine, triethanolamine, amino Hydroxymethylpropanediol, 2-amino-2
-Methyl-1-propanol, 2-amino-2-methyl-1,3-propanediol, basic amino acids, ammonia and the like can be used. Further, solvents other than water, such as ethanol, ethylene glycol, 1,3-butylene glycol, propylene glycol, glycerin, polyethylene glycol, benzyl alcohol, benzyloxyethanol; urea, bactericides, preservatives, pearlizing agents, dyes,
Fragrances, thickeners, chelating agents, etc. can be added.

To treat hair with the pretreatment agent of the present invention,
The pretreatment agent of the present invention is applied to hair and the hair is applied for a certain period of time, for example, 2 to
Leave it for 10 minutes. It should be noted that a large amount may be applied to a severely damaged portion such as the tip of hair, and a small amount may be applied to a substantially undamaged portion such as a root.

After such pretreatment, if the hair is subjected to a normal permanent wave treatment, a uniform wave can be applied from the root to the tip of the hair. Here, as the permanent wave treatment, a disulfide (—S—S—) bond in the hair is reduced and opened by using a permanent wave first agent containing an ordinary reducing substance as a main component,
Next, this hair is set in a desired shape using a curler or the like, and further oxidized with a permanent wave second agent containing an oxidizing agent such as bromic acid (salt), perboric acid (salt) and hydrogen peroxide as a main component, The method of closing and fixing the set is used. The permanent wave first agent used here is preferably thioglycolic acid or a salt thereof as a main component, but another reducing agent such as cysteine or N-acetyl cysteine or a derivative thereof is a main component. But it's okay.
Further, the first agent may contain dithiodiglycolic acid or a salt thereof.

[0030]

EFFECT OF THE INVENTION Prior to the permanent wave treatment,
The hair treated with the pretreatment agent of the present invention can form a uniform wave from the root to the tip even if the tip of the hair is excessively damaged, and can maintain the shape of the wave for a long period of time. It also has the effect of protecting the hair.

[0031]

The present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

Example 1 Unbleached hair obtained from a healthy female in her 20s was bleached twice on a portion having a tip of about 7 cm and artificially damaged, 20 g of which was used as a hair bundle. This hair bundle was subjected to a permanent wave treatment according to the following processing flow, and the uniformity of the wave, the stickiness of the wave and the ability to protect the hair were evaluated. (1) Processing flow a. Pretreatment: Prior to the permanent wave treatment, the pretreatment agent of the present invention is applied to the damaged part of the hair, and the hair is well blended for 5 minutes or 15 minutes. b. Winding: Wrap hair around a rod with a diameter of 1.5 cm with the end paper sandwiched between the ends. Regarding Comparative Example 3, when the hair was wound around the rod, 0.08 g of diammonium dithiodiglycolate was added to each end wrap.
Wrap with a soaked product. c. First agent: The first agent is applied to hair at a bath ratio of 1: 3 (hair: first agent) and left for 10 minutes. d. Second agent: The second agent is applied to hair at a bath ratio of 1: 3 (hair: second agent), and left for 10 minutes. Remove the hair from the rod, rinse it thoroughly with running water, hang it with the root up and let it air dry. (2) Evaluation method A. Evaluation of wave uniformity

[0033]

[Equation 1]

The curl diameter of the hair was determined by measuring the diameters of the curls formed at 5 cm from the root and 5 cm from the tips of the hair selected randomly from 30 hair bundles, and calculating the average thereof. ○: 90 or more △: 80 or more and less than 90 ×: less than 80 B. Evaluation of wave mochi

[0035]

[Equation 2]

The curl diameter of the hair was measured by measuring the diameter of curls formed immediately after the treatment and after 10 times of shampoo for 5 cm from the tips of 30 randomly selected hairs from the hair bundle, and calculate the average value. I asked. ○: 90 or more △: 80 or more and less than 90 ×: less than 80 C.I. Evaluation of hair protection ability

[0037]

[Equation 3]

The breaking strength of the hair was determined by measuring the load required to break each of the 30 randomly selected hairs from the same hair bundle before and after the treatment using a tensile tester. , And calculated the average. ○: 80 or more △: 60 or more and less than 80 ×: less than 60 Evaluation item A. B. C. The closer to 100, the more effective. (3) Results As a result, as shown in Table 1 and Table 2, when the pretreatment agent of the present invention is used, a permanent wave effect with no damage to the hair and a good durability is obtained.

[0039]

[Table 1]

[0040]

[Table 2]

Example 2 Hair was pretreated in the same manner as in Example 1 using the pretreatment agents shown in Table 1 and Table 2, and then the hair was treated with the first and second agents. Similar to Example 1, the treated hair was evaluated for wave uniformity, wave retention, and hair protection ability. As a result, as shown in Tables 3 and 4, the hair treated with the pretreatment agent of the present invention has a more uniform wave, as compared with the hair pretreated with the pretreatment agent containing a keratin hydrolyzate or an oily component. It was excellent in both the mochi's stickiness and the ability to protect hair.

[0042]

[Table 3]

[0043]

[Table 4]

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[Procedure amendment]

[Submission date] November 13, 1991

[Procedure Amendment 1]

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[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a permanent wave pretreatment liquid , more specifically, a permanent wave pretreatment for adjusting the permanent wave forming ability and preventing hair damage by applying to the hair prior to the permanent wave treatment. Regarding liquid .

[Procedure Amendment 2]

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In order to prevent damage to the hair caused by such permanent wave treatment, prior to the permanent wave treatment, for example, methylpolysiloxane, paraffin, or a protein component (such as protein) is added to supplement the oil lost by elution. Hydrolyzate)
A method has been proposed for softening the excessive reducing action of the first agent on the damaged part by supplementing the above or by applying a compound having a high adsorbing action to the hair (JP-A-55-1).
11412, JP-A-56-103106, JP-A-5
No. 8-39612, JP-A-60-116623, JP-A-60-243010, and JP-B-63-502104.
JP-A 64-2603, JP-A-2-78607
issue). However, although these pretreatment agents are effective for mild damage, they have been treated with permanent waves and hair coloring several times, especially the tip of hair that has grown to a length of several tens of centimeters. However, the effect is not sufficient. Also, as another way of thinking,
Since the reduction of hair by a reducing agent occurs in an equilibrium reaction with cystine bonds in the hair, the first wave of the permanent wave treatment contains a disulfide compound which is an oxidant of a thiol compound such as thioglycolic acid, and the law of mass conservation Has also been devised to prevent the reduction equilibrium from proceeding too much in the direction of cleavage of the cystine bond (Japanese Patent Publication No. 45-15).
397, US3840656, JP-A-63-2552.
15, EP 0346453, DE 3707415).
However, in this method, the permeation of dithiodiglycolic acid or a salt thereof into hair is generally insufficient as compared with the permeation of a reducing agent such as thioglycolic acid, and especially when the tip of the hair is excessively damaged. Cannot obtain a sufficient reduction suppressing effect. Further, when the content of dithiodiglycolic acid or a salt thereof is increased in order to enhance the reduction inhibitory effect, the reduction inhibitory effect extends not only to the damaged part but also to the healthy part, so that the obtained wave becomes very gentle. I will end up. To take this idea a step further, a method of impregnating an end wrap with a disulfide compound has been proposed (US
4600028). Here, the end wraps sandwich the tip of the hair divided into hair bundles when the hair is wrapped around a rod or the like, and are made of paper or urethane. That is, in general, only the tip of hair that is severely damaged is wrapped with an end wrap impregnated with a disulfide compound, so as to suppress the reducing action, as in the case where the disulfide compound is contained in the first permanent wave treatment liquid. To do. However, in this method, the reduction effect is suppressed only in the part of the hair wrapped in the end wrap that is in contact with the end wrap, and not only the effect is insufficient, but on the contrary,
The unevenness of the waves in the wrapped part causes unevenness, which is very inconvenient. In addition, this method cannot be used for treatments that do not use end wraps such as straight perms.

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The dithiodiglycolic acid used in the present invention is
It is represented by the following formula. The HOOC-CH ₂ salt of -S-S-CH ₂ -COOH dithiodiglycolic acid, sodium di-alkali metal salts such as dipotassium, di monoethanolamine, di-diethanolamine, ethanolamine salts such ditriethanolamine salt and Examples thereof include a diammonium salt, and a diammonium salt represented by the following formula is particularly preferable.

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To treat hair with the pretreatment agent of the present invention,
The pretreatment agent of the present invention is applied to hair and the hair is applied for a certain period of time, for example, 1 to
Leave it for 10 minutes. It should be noted that a large amount may be applied to a severely damaged portion such as the tip of hair, and a small amount may be applied to a substantially undamaged portion such as a root.

[Procedure Amendment 5]

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Example 1 Unbleached hair obtained from a healthy female in her 20s was bleached twice on a portion having a tip of about 7 cm and artificially damaged, 20 g of which was used as a hair bundle. This hair bundle was subjected to a permanent wave treatment according to the following processing flow, and the uniformity of the wave, the stickiness of the wave and the ability to protect the hair were evaluated. (1) Processing flow a. Pretreatment: Prior to the permanent wave treatment, the pretreatment agent of the present invention is applied to the damaged part of the hair, and the hair is well blended for 5 minutes or 15 minutes. b. Winding: Wrap hair around a rod with a diameter of 1.5 cm with an end wrap. Regarding Comparative Example 3, when the hair was wound around the rod, 0.08 g of diammonium dithiodiglycolate was added to each end wrap.
Wrap with a soaked product. c. First agent: The first agent is applied to hair at a bath ratio of 1: 3 (hair: first agent) and left for 10 minutes. d. Second agent: The second agent is applied to hair at a bath ratio of 1: 3 (hair: second agent), and left for 10 minutes. Remove the hair from the rod, rinse it thoroughly with running water, hang it with the root up and let it air dry. (2) Evaluation method A. Evaluation of wave uniformity

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[0040]

[Table 2]

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Example 2 Hair was pretreated in the same manner as in Example 1 using the pretreatment agents shown in Tables 3 and 4 , and then the same first agent as in Example 1 ,
The hair was treated with the second agent. Regarding the treated hair, Example 1
Similarly, the uniformity of the wave, the retention of the wave, and the ability to protect the hair were evaluated. As a result, as shown in Tables 3 and 4,
The hair treated with the pretreatment agent of the present invention has, in comparison with the hair pretreated with the pretreatment agent containing a keratin hydrolyzate or an oily component, any of uniformity of wave, waviness of hair, and hair protecting ability. Was excellent. ─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] February 13, 1992

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[0035]

[Equation 2]

Claims (3)

[Claims] 1. A dithiodiglycolic acid or a salt thereof is added to
5 to 30% by weight of a permanent wave pretreatment aqueous liquid. 2. The permanent wave pretreatment aqueous solution according to claim 1, further comprising a surfactant. 3. A dithiodiglycolic acid or a salt thereof is added to
A method for imparting a permanent wave to hair, which comprises treating the hair with an aqueous liquid containing 5 to 30% by weight of a permanent wave and then performing a permanent wave treatment.