KR101817980B1 - Color-fixing hairdye composition using penetration enhancement of mordant dyes - Google Patents

Abstract

The present invention relates to a mordant hair dye composition using a salt penetration enhancing technique. More particularly, the present invention relates to a hair dye composition comprising a swelling agent, a reducing agent, a salt and a mordant, wherein the swelling agent and the reducing agent improve hair penetration of the hair dye, It acts as a salt that can be mordant with metal, and it dramatically improves dyeing power and sustainability, allowing natural dyeing of hair.

Mordant, salt, penetration, hair dye

Description

[0001] Color-fixing hairdye composition using penetration enhancement of mordant dyes [

TECHNICAL FIELD The present invention relates to a mordant salt composition using a salt penetration enhancing technique, and more particularly, to a two-part salt mordant composition comprising a swelling agent, a reducing agent, a salt and a mordant.

The hair dye is classified into a permanent hair dye, a permanent hair dye and a temporary hair dye depending on how long the dyed color lasts. In addition, depending on the mechanism of dyeing, it can be classified into oxidation type hair dyeing agent and non-oxidation type hair dyeing agent. There are permanent hair dyeing agents using oxidative synthetic dyes for oxidative dyeing agents, semi-permanent hair dyeing agents using acid dyes, vegetable hair dyeing agents using vegetable dyes such as henna and chamomile, and metallic hair dyeing agents using mordanting agents containing metal salts .

However, permanent hair dyeing agents using oxidative synthetic dyes are known to cause allergies to humans, and vegetable hair dyeing agents using plant dyes such as henna and chamomile have a limited color tone and are not only dyed in black hair of Asian It is reported to cause allergies to the human body. In addition, acid dyes are poor in consistency due to weak binding force with hair, and there is a problem that the skin becomes dyed by being stained on the skin.

On the other hand, a hair dye having been emulsified or suspended in powdery plant dyes and liquid silicone (silicone), paraffin, vegetable or animal oil, and surfactants has also been proposed. However, such a hair dye has the disadvantage that it is difficult to obtain a sufficient effect on the color expression power, which is the highest priority as a hair dye, although stability and usability of the hair dye are improved.

As a result, studies have been made on a metallic hair dye using a metal as a mordant for increasing the fastness and coloring property of the dye.

The mordant salt is an operation for treating a dyestuff with a drug which produces a colored compound which is insoluble (insoluble) when it is dyed with a dye (mordant dyestuff) having no dyeability It says. In other words, it refers to an operation of treating a dye that is not directly dyeable to the target dyed with an agent that completes dyeing by connecting it to the dyed material because of lack of affinity for the dyed material.

Conventional metallic hair dyeing agents contain metallic compounds such as iron, copper, zinc, silver, and bismuth as mordants, and contain metallic compounds such as gallic acid, gallic acid esters, tannic acid and esters thereof or pyrogallol as coloring agents, And dyeing by the reaction of the metal ion and the coloring agent. This hair dye is a hair dye that is useful for people who cause an allergic reaction to oxidative hair dye because they have no primary irritation or sensitivity to the human body.

In the ordinary mordanting reaction, the mordanting is classified into pre-mordanting, simultaneous mordanting and post-mordanting. Herein, the term mordenite refers to a method of treating a dye after treatment with a mordant, and the term "mordant" refers to a method of treating a mordant after treating a dye. Simultaneous mordanting refers to a treatment of a mordant and a dye simultaneously. Currently, hair dyeing agents commercialized using such a mushing mechanism are seldom found, but in the market, it is known that they are formed by postmeal dyeing. The dyeing method using the post mordant method shows the best dyeing power in the mordant dyeing agent, but it is insufficient than the dyeing power by the oxidized permanent dyeing agent. The reason why the dyeing agent using the mordanting method is less dyed than the oxidative permanent hair dyeing agent and the durability is not improved much more than the reaction mechanism of the coordination bonding is because the mordanting reaction occurs mainly on the surface of the hair.

The inventors of the present invention conducted continuous research to improve the dyeability and color persistence of the hair dye composition using mordant technology to solve the above problems. As a result, the inventors of the present invention found that a hair dye composition having a two- It has been found that not only dyeability and color sustainability are improved by enhancing the penetration ability of the salt in the inside of the hair but also damage of the scalp and hair due to dyeing can be minimized when a natural origin salt is used as a salt, .

Therefore, it is an object of the present invention to provide a dyed hair dye using the mushing technology and to provide durability superior to the oxidized dyed hair dye, and to provide dyes free from hair damage or skin irritation when natural dyes are used To provide a mordant salt detergent composition.

In order to accomplish the above object, the present invention provides a mordant hair dye composition of a two-part formulation containing a swelling agent, a reducing agent, a salt and a mordant.

Further, the hair dye composition of the present invention may further contain at least one kind selected from a solvent and a buffer.

The mushroom hair dye composition of the present invention can enhance the penetration ability of the dye into the hair using the mushing technique, and can be used as a dyeing agent and a reducing agent, which are capable of acting as a salt, It has a remarkable effect that it is higher than the hair dye level.

More particularly, the present invention relates to a mordant salt composition comprising a swelling agent, a reducing agent, a salt and a mordant, And improving dyeability and durability through a reducing agent.

Further, the hair dye composition of the present invention may further contain at least one kind selected from a solvent and a buffer.

The hair dye composition of the present invention may contain both a salt and a mordant in the preparation 1 and a mordant in the preparation 2, and the swelling agent, the reducing agent, the solvent and the buffer may be included in the one or two agents, have.

The swelling agent used in the hair dye composition of the present invention may be included in both the one agent and the two agents, and the swelling agent changes the? -Keratin structure to the? -Keratin structure by breaking hydrogen bonds inside the hair, The penetration into the inside of hair can be improved and the dyeability of hair caused by mordanting can be greatly improved.

The swelling agents that may be included in the first and second agents may include and contain urea, guanidine or salts thereof, and more specifically, urea, thiourea, urea peroxide, polyoxymethylene urea, polyoxymethylene cyanoguanidine urea, imidazolidinyl urea, hydroxyethyl urea, dimethyl urea, and the like. , Dimethylol urea, diazolidinyl urea, m-dimethylaminophenyl urea, dimethylol ethylene thiourea, monoethanol urea, Guanidine hydrochloride, guanidine hydrochloride, guanidine carbonate, guanidine phosphate, lauramidobutyl acetate, guanidine acetate, PEG-6 stearylguanidine, palmitamido butyl guanidine acetate, diglycol guanidine succinate, aminoguanidine bicarbonate, Aminoguanidine hydrochloride, and salts thereof. The present invention is further characterized in that it contains at least one selected from the group consisting of aminoguanidine hydrochloride and salts thereof.

In addition, the above-mentioned urea and guanidine-based swelling agents, except for a large change in the pH directly, and in the case of raw materials commonly used as alkalizing agent in the hair dye, As such, it is preferably not included in the binary agent. Examples thereof include L-arginine, tromethamine, monoethanolamine, diethanolamine, triethanolamine, isopropanolamine, potassium hydroxide, sodium hydroxide, sodium carbonate, aminomethylpropanol, .

The swelling agent is contained in an amount of 0.1 to 40% by weight, preferably 0.1 to 20% by weight, based on the total weight of the hair dye composition. When the amount of the swelling agent is less than 0.1% by weight, it is difficult to impart sufficient swelling effect to the hair. When the amount of the swelling agent is more than 40% by weight,

The reducing agent used in the hair dye composition of the present invention can be contained in the first agent and the second agent and by loosening the bonds in the hair to improve the penetration of the salt into the keratin fibers together with the swelling agent, It is very effective in enhancing dyeability and durability by mordanting reaction by increasing the density of the salt.

Wherein the reducing agent is selected from the group consisting of thiols such as cysteine, homocysteine or thiol lactic acid, salts of such thiols, phosphines, bisulfites, sulfites, thioglycolic acids and esters thereof, especially glycerol monothioglycolate and thioglycerol, And it is effective to use thioglycolic acid and salts thereof and cysteine and salts thereof, though it is not particularly limited in kind. In particular, it is effective to prevent hair damage by using them. Thioglycolic acid and salts thereof and cysteine and salts thereof not only enhance the penetration ability of the salt into the hair but also act as a salt which can be mordanted with the metal contained in the second agent, It has better properties than the swelling agent.

The reducing agent is contained in an amount of 0.01 to 10% by weight, preferably 0.1 to 5% by weight, based on the total weight of the hair dye composition. If the content of the reducing agent is less than 0.01% by weight, the effect of improving the permeability of the salt may not be sufficient. If the content of the reducing agent is more than 10% by weight, hair damage may be caused.

Examples of the natural-derived salt used as a coloring agent in the hair dye composition of the present invention include a variety of natural materials such as gallic acid, gallic acid esters, tannic acid and its esters, pyrogallol, logwood, Safflower, lupine, gardenia, lanceolate, persimmon, rhododendron, duckwood, and the like. There is no particular limitation on the kind thereof, and a natural-derived salt material which can usually be mordant can be used. Using a naturally occurring salt as a salt can reduce irritation on the scalp, protect hair after dyeing, and minimize damage. The natural-derived salt is contained in an amount of 0.01 to 20% by weight based on the total weight of the composition.

In addition, the salt used as a coloring agent in the hair dye composition of the present invention may use an oxidative dye composed of an oxidative dye precursor and a coupler in addition to the natural-derived salt as the salt. Although the kind of the oxidation dye precursor is not particularly limited, it is preferably one selected from the group consisting of o-aminophenol, m-aminophenol, p-aminophenol, p-phenylenediamine, toluene-2,5-diamine hydrochloride, P-phenylenediamine sulfate, p-methylaminophenol sulfate, o-aminophenol sulfate, p-aminophenol sulfate, toluene-2,5-diamine sulfate, p- , And the oxidation dye precursor is used in an amount of 0.001 to 5.0% by weight based on the total weight of the composition. Examples of the coupler include 2-methyl-5-hydroxyethylaminophenol, p-amino-ocresol, m-aminophenol, 2,4-diaminophenoxyethanol hydrochloride, m- m-phenylenediamine,? -naphthol, resorcinol, 2-methylresorcinol and the like can be used. The coupler is used in an amount of 0.001 to 5.0% by weight based on the total weight of the composition of the first composition, and can be mixed with the oxidation dye precursor to exhibit various hues on the hair.

The direct dye may be added to the hair dye composition of the present invention to the extent that it does not impair the object of the present invention. Examples of such direct dyes include Arianol dye, p-nitro phenylenediamine, nitro-p-phenylenediamine, 2-amino-4-nitrophenol, 2-amino-5-nitrophenol, nitro-p-phenylenediamine hydrochloride, (Henna) can be used.

Examples of synthetic mordants include water-soluble metal salts such as Al, Cu, Cr, Fe, Sn and Ni, and the like. Examples of the mordant used in the hair dye composition of the present invention include lye, iron, The kind thereof is not particularly limited, and any material which can be used as a mordant usually can be used. The mordant is contained in an amount of 0.01 to 20% by weight based on the total weight of the hair dye composition. The salt used in the present invention can express various colors depending on the combination with the mordant.

In addition, a solvent may be used to double the effect of enhancing the penetration of the hair dye into the inside of the hair, which may be included in the first and second agents of the composition, and ethanol, isopropyl alcohol, benzyl alcohol, But there is no particular limitation on the kind thereof, and a solvent used for ordinary purposes can be used. The solvent is contained in an amount of 0.01 to 50% by weight based on the total weight of the hair dye composition.

In addition, the buffer used in the hair dye composition of the present invention may be included in the hair dye preparation 1 and the hair dye preparation 2, and has a smaller molecular weight so as to be more effective on hair, and is composed of an organic acid, an alkali and a salt thereof. The buffer may comprise one or more of the following: potassium hydroxide, sodium hydroxide, aqueous ammonia, phosphoric acid, clinic acid, citric acid, acetic acid, hydrochloric acid, sulfuric acid, sodium carbonate, sodium salicylate / salicylic acid, Lactic acid / sodium lactate is used in the composition.

The buffer is contained in an amount of 0.01 to 10% by weight, preferably 0.1 to 5% by weight, based on the total weight of the hair dye composition. If the content of the buffer is less than 0.01% by weight, the effect of the buffer may not be sufficient. If the content of the buffer is more than 10% by weight, there may be a problem of stability in making the formulation convenient to use.

In addition, erythorbic acid, ascorbic acid, and salts thereof may be used as antioxidants for the purpose of preventing the dye mordant reaction and preventing oxidation of the contents in the hair dye composition of the present invention.

In addition, cationic surfactants, anionic surfactants, nonionic surfactants, and amphoteric surfactants may be used alone or in combination as a surfactant for higher alcohol, nonionic and anionic polymer thickeners and surfactants for increasing purposes. Known components such as polyols such as propylene glycol, 1,3-butylene glycol and glycerin, hair conditioning agents, quaternary ammonium salts, cationic polymers, silicones, amino acids and proteins, and perfume pH adjusting agents have.

The mush salt hair composition of the present invention is not particularly limited in formulation, but it is preferable to formulate the one and two agents into powder, liquid, cream, lotion or gel.

Hereinafter, the constitution and effects of the hair dye composition according to the present invention will be described with reference to Examples and Comparative Examples. However, the present invention is not limited to these embodiments, and may be modified into various forms.

[Reference Example] Preparation of a hair dye composition using mordant technology

A cream type of preparation was prepared with the composition as shown in Table 1 below and a cream type preparation with the composition shown in Table 2 below and the hair dye composition of Examples 1 to 4 and Comparative Examples 1 to 6 was prepared by the combination of Table 3 . In Table 1 and Table 2, the unit is wt%.

division 1 Production Example 1 Production Example 2 Production Example 3 Production Example 4 Production Example 5 Production Example 6 Production Example 7 Production Example 8 Production Example 9 Mechanism Cetearyl alcohol 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 Mechanism Polyoxyethylene
Stearyl ether 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 menstruum Benzyl alcohol 5.0 5.0 5.0 - 5.0 5.0 5.0 5.0 5.0 Polyol Propylene glycol 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 Salt Pyrogallol 2.0 2.0 2.0 2.0 - - 2.0 - 2.0 p-phenylenediamine - - - - - - - One - m-Aminophenol - - - - - - - 0.4 - Resorcinol - - - - - - - 0.7 - Oxidation
Inhibitor Ascorbic acid 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 reducing agent Monoethanolamine
Thioglycolate 2.0 - 2.0 2.0 6.0 2.0 - 2.0 2.0 L-cysteine - 1.0 - - - 3.0 - - - N-acetyl-
L-cysteine - 1.0 - - - 1.0 - - - Swelling agent Monoethanolamine - - - - - - 1.0 - - L-arginine - - 2.0 2.0 2.0 2.0 - 2.0 2.0 Tromethamine - - 4.0 4.0 4.0 4.0 - 4.0 4.0 Sodium hydroxide One One 0.5 0.5 0.5 0.5 0.5 0.5 0.5 buffer Sodium carbonate 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Swelling agent Element 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 - Purified water Suitable amount Suitable amount Suitable amount Suitable amount Suitable amount Suitable amount Suitable amount Suitable amount Suitable amount pH - 6.52 6.53 6.52 6.55 6.75 6.74 6.48 6.54 6.48

division 2 Production Example 10 Production Example 11 Production Example 12 Mechanism Cetearyl alcohol 10.0 10.0 10.0 Mechanism Polyoxyethylene
Stearyl ether 3.0 3.0 3.0 menstruum Benzyl alcohol 2.0 2.0 2.0 Polyol Propylene glycol 3.0 3.0 3.0 Mordant Iron sulfate 4.0 4.0 4.0 Antioxidant Ascorbic acid 0.2 0.2 0.2 buffer Salicylic acid 0.3 0.3 - Sodium salicylate 0.7 0.7 - Swelling agent Element 10.0 - 10.0 Purified water Suitable amount Suitable amount Suitable amount pH 3.22 3.19 3.31

division 1 2 Example 1 Production Example 1 Production Example 10 Example 2 Production Example 2 Production Example 10 Example 3 Production Example 3 Production Example 10 Example 4 Production Example 4 Production Example 10 Comparative Example 1 Production Example 5 Production Example 10 Comparative Example 2 Production Example 6 Production Example 10 Comparative Example 3 Production Example 7 Production Example 10 Comparative Example 4 Production Example 8 Production Example 10 Comparative Example 5 Production Example 9 Production Example 11 Comparative Example 6 Production Example 3 Production Example 12

[Test Example 1] Evaluation of color expressive power

In order to test the color expressive power, the compositions of Examples 1 to 4 and Comparative Examples 1 to 6 were subjected to hair dyeing using the hair dye composition in combination of Table 3 above. First, the amount of the hair was taken twice as much as the weight of the hair, and the hair was uniformly applied to 23 cm of standard hair, left for 20 minutes, and then applied again for 20 minutes (20 to 30% And the L * value is 22.54). After the application and storage time was completed, the hair was washed with running water using a shampoo solution for 1 minute and then dried using a hair dryer. The dried hair was measured for color using a color difference meter (model: Hunterlab Labscan XE).

The results were compared using the L ^* value before and after dyeing measured by colorimeter. The L ^* value is a value representing the lightness. The smaller the value of L ^* , the darker the color, which means that the color expressing power is excellent. The results are shown in Table 4 below.

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 L ^* 12.32 12.41 10.88 10.85 15.85 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 L ^* 15.94 14.54 10.92 11.55 11.92

As shown in Table 4, it can be seen that Comparative Examples 1 and 2 do not contain pyrogallol, which is a salt, so that the dyeing ability is remarkably lowered compared with the embodiment, but dyeing is possible. And the swelling agent acts as a mordant salt instead of pyrogallol.

In the case of Comparative Example 3, there is a difference in that the reducing agent is not contained as compared with Example 1, but in Comparative Example 3, the reducing agent is not contained in the dyeing agent.

In addition, in Examples 3 and 4, it can be confirmed that the color expressing ability is higher as the content of the swelling agent is higher as compared with Examples 1 and 2. [ Compared with Example 3, Comparative Example 5 contains a swelling agent such as arginine and tromethamine, which is superior in dyeing power than Example 1, It can be seen that there is a large difference in dyeing power depending on presence or absence of urea as a swelling agent.

Further, in Examples 3 and 4, it can be seen that the dyeing powers of benzyl alcohol as a solvent are not substantially different from each other.

As compared with Example 3, Comparative Example 4 was different from Example 3 in that an oxidative dye was used instead of pyrogallol, which is a salt derived from natural material, as a salt. From the above results, it was found that even when using a natural- And there is no significant difference in dyeability.

Further, when comparing Examples 1 and 3, it is not as good as dyeing effect as in the case of using a swelling agent such as arginine or tromethamine

Also, in Comparative Example 6, there is a difference in that buffers are not used in Examples 3 and 2, and it is very important to maintain a specific pH in the mordant.

[Test Example 2] Evaluation of damage to hair

In order to evaluate the degree of hair damage on whether the hair dyed in Examples 1 to 4 and Comparative Examples 1 to 6 were damaged, five dyed hairs were evaluated according to the following criteria, and the results are shown in Table 5 Respectively.

<Evaluation Criteria>

○: softness, Χ: roughness

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Hair
touch ○ ○ ○ ○ X Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Hair
touch ○ ○ ○ ○ ○

As shown in Table 5, considering hair and scalp damage as well as dyeing power, even when monoethanolamine thioglycolate alone was used alone in the case of containing a small amount of reducing agent, there was no hair damage, but Comparative Example 1 and Comparative Example 2 The use of monoethanolamine thioglycolate alone as a reducing agent alone was found to be more effective in enhancing staining power and preventing hair damage by using L-cysteine and N- .

[Test Example 3] Color persistence evaluation

The hair dyed in Test Example 1 was put in a shampoo solution and shaken at a speed of 200 rpm for 30 minutes using a shaker, rinsed for 1 minute in running water, and dried with a hair dryer. This procedure was repeated three times, and then the color persistence was evaluated by using a colorimeter after drying, using the difference from the L ^* value in Test Example 1,? L ^* value. The smaller the value of ΔL ^* , the better the color persistence. The results are shown in Table 6 below.

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 DELTA L ^* 1.19 1.17 0.54 0.81 0.22 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 DELTA L ^* 0.24 3.2 0.52 0.75 0.92

As shown in Table 6, it can be seen that the color sustainability is significantly different depending on whether the swelling agent, solvent, or reducing agent of the present invention is contained or not.

In Comparative Examples 1 and 2, the color persistence is excellent even when the reducing agent is included, even though pyrogallol, which is a salt, is not present. However, in Comparative Example 3,

In the case of Comparative Examples 5 and 6 in which the elements and buffers are not used in comparison with Embodiment 3, the value of DELTA L ^* is larger than that in Embodiment 3, thereby affecting the color persistence depending on whether or not the element and buffer are used Can be confirmed.

In addition, in Examples 3 and 4, it can be confirmed that the color persistence is higher as the content of the swelling agent is higher than that of Examples 1 and 2. [

In Examples 3 and 4, the dyeing powers of the solvent benzyl alcohol were almost the same, but the color persistence was affected.

In the case of the swelling agent, it was confirmed that the swelling agent having a mordant resistance with the metal contained in the bilayer, that is, a salt agent, rather than the swelling of the hair by simply controlling the pH, contributes more to the improvement of the color sustainability.

Claims (20)

A hair dye composition for postmeat hair comprising a swelling agent, a reducing agent, a naturally occurring salt agent and a mordanting agent, The salt hair dye composition is a two-dosage form, the salt material is included in the first agent, the mordant agent is included in the second agent, Wherein the swelling agent is selected from the group consisting of urea, thiourea, urea peroxide, polyoxymethylene urea, polyoxymethylene cyanoguanidine urea, imidazolidinyl urea imidazolidinyl urea, hydroxyethyl urea, dimethyl urea, dimethylol urea, diazolidinyl urea, m-dimethylaminophenyl urea, But are not limited to, dimethylol ethylene thiourea, monoethanol urea, guanidine, guanidine hydrochloride, guanidine carbonate, guanidine phosphate, laurethamide guanidine acetate lauramidobutyl guanidine acetate, PEG-6 stearylguanidine, palmitamido butyl guanidine &lt; RTI ID = 0.0 &gt; at least one selected from the group consisting of e acetate, diglycol guanidine succinate, aminoguanidine bicarbonate, aminoguanidine hydrochloride and salts thereof, Wherein the reducing agent is at least one member selected from the group consisting of cysteine and homocysteine, The naturally occurring salt may be at least one selected from the group consisting of gallic acid, gallic acid esters, tannic acid and its esters, pyrogallol, logwood, yellow whitish, chrysanthemum, firefighting, cochineal, fenugreek, safflower, And at least one member selected from the group consisting of almonds, almonds, and birds. [2] The hair dyeing composition for hair follicles according to claim 1, wherein the hair dye composition further comprises at least one selected from a solvent and a buffer. delete [3] The hair dyeing composition for hair follicles according to claim 1, wherein the swelling agent is contained in an amount of 0.1 to 40% by weight based on the total weight of the composition. [3] The hair dyeing composition for hair follicles according to claim 1, wherein the reducing agent is present in an amount of 0.01 to 10% by weight based on the total weight of the composition. delete [3] The hair dyeing composition for hair follicles according to claim 1, wherein the natural hair dye is contained in an amount of 0.01 to 20% by weight based on the total weight of the composition. delete delete delete delete delete The hair dyeing composition of claim 1, wherein the hair dye composition for post hye is selected from the group consisting of Arianol dyes, p-nitro-o-phenylenediamine, nitro-p-phenylenediamine, 2- -5-nitrophenol, nitro-p-phenylenediamine hydrochloride, piclaminic acid, and Henna. The hair dyeing composition of claim 1, wherein the direct dye is selected from the group consisting of: [3] The hair dyeing composition for hair follicles according to claim 2, wherein the solvent is contained in an amount of 0.01 to 50% by weight based on the total weight of the composition. 3. The method of claim 2, wherein the buffer is selected from the group consisting of sodium carbonate; Or sodium salicylate and salicylic acid, wherein the sodium carbonate is contained only in one agent, and the sodium salicylate and salicylic acid are contained only in the two agents. The hair dyeing composition according to claim 2, wherein the buffer is contained in an amount of 0.01 to 10% by weight based on the total weight of the composition. delete delete delete delete