JP2004323449A - Acid hair dye and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an acid hair dye having good dyeability even when the amount of the acid dye is decreased and to provide a method for producing the acid hair dye. <P>SOLUTION: In the acid hair dye in which a base material for hair fixing is formulated with an acid for regulating pH and the acid dye in purified water, the content of the acid dye is kept to ≤0.02 wt.% and an α-hydroxyacid ester (excluding malic acid diester) in an amount of ≥2 wt.% is further added thereto and the mixture is stirred at 3,500-5,000 rpm number of revolution for 15-25 min and the mixture is emulsified to provide the acid hair dye. A moisturizing component can be added thereto. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an acidic hair coloring material having good dyeing properties despite the reduced amount of the acid dye, and a method for producing the same.
[0002]
[Prior art]
A conventional acid hair dye is obtained by blending a hairdressing base, an acid for adjusting pH, and an acid dye (legal dye) of 0.05% by weight or more in purified water. In this acidic hair dye, the dyeing of the hair depends on the permeability of the dye, and the amount of the acid dye is increased in order to improve the dyeing property.
[0003]
For this reason, when a dye adheres to hands, clothes, etc., there is a problem that it cannot be easily removed.
[0004]
[Problems to be solved by the invention]
An object of the present invention is to solve the above-mentioned drawbacks and to provide an acidic hair dye having good dyeing properties even when the amount of the acid dye is reduced.
[0005]
[Means to solve the problem]
In order to achieve the above object, the present inventors have conducted intensive studies and found that the addition of malic acid diester improves the hydrophilic / hydrophobic balance and greatly improves the dyeing properties. The inventors have found that acid dyes are finer and the permeability to hair is improved, and applied for this (Japanese Patent Application No. 2002-100707).
As a result of continued research, the present inventors have found that almost the same effect can be obtained by using an α-hydroxy acid ester other than malic acid diester.
[0006]
That is, the acidic hair dye of the present invention, in purified water, a hair styling base, an acid for pH adjustment, and an acid hair dye prepared by mixing an acid dye,
The acid dye is adjusted to 0.02% by weight or less, and α-hydroxy acid ester (excluding malic acid diester) is added at 2% by weight or more. It becomes.
Further, a moisturizing component may be added.
[0007]
The method for producing an acidic hair dye of the present invention comprises a hair styling base, 0.02% by weight or less of an acid dye, and 2% by weight or more of α-hydroxy acid ester (excluding malic acid diester) in purified water. Is added, an acid for pH adjustment is added to adjust the pH, and then the mixture is put into a vacuum homomixer and stirred at a rotation speed of 3500 to 5000 rpm for 15 to 25 minutes to emulsify.
[0008]
As the α-hydroxy acid ester (excluding malic acid diester), those widely used in cosmetics such as tartaric acid diester, lactate ester and citrate ester are used.
The hair styling base may be any known one and is not particularly limited. For example, a mixture of polyoxyethylene lauryl ether, polyacrylamide, isopropyl palmitate, and soft liquid isoparaffin in a ratio of 3: 20: 50: 50.
Moreover, the acid for pH adjustment is what is conventionally added to the acidic hair dye, and for example, citric acid is used.
Acid dyes have been used in the past, such as black 401, red 102, yellow 4, etc., which are specified by the “Ministerial Ordinance for Specifying Tar Dyes for Use in Pharmaceuticals” (statutory law). Dye).
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the production method of the present invention will be described.
First, a hair styling base, 0.02% by weight or less of an acid dye, and 2% by weight or more of a tartaric acid diester are added to purified water.
As a hairdressing base, a mixture of polyoxyethylene lauryl ether, polyacrylamide, isopropyl palmitate, and soft liquid isoparaffin in a ratio of 3: 20: 50: 50 is used.
[0010]
Further, as moisturizing components, 1,3-butylene glycol, jojoba oil, camellia oil, methylphenylpolysiloxane, D-pantothenyl alcohol, sodium hyaluronate solution, mixed plant extract, hydrolyzed conchiolin solution, hydrolyzed silk solution Is added.
Next, the pH is adjusted to about 3.5 by adding citric acid.
[0011]
Next, the above liquid is stirred with a vacuum homomixer at a rotation speed of 3500 to 5000 rpm for 15 to 25 minutes and emulsified to obtain an acidic hair dye.
[0012]
When the above-mentioned acidic hair dye is stirred at a high speed for a short time, the acid dye becomes finer and easily penetrates into the hair. By adding tartaric acid diester in an amount of 2% by weight or more, the hydrophilic / hydrophobic balance is improved and the dyeability is greatly improved.
Note that, instead of the tartaric acid diester, an α-hydroxy acid ester such as a lactic acid ester or a citric acid ester may be used.
[0013]
【The invention's effect】
In short, in the present invention, the acid hair dye is added with 2% by weight or more of α-hydroxy acid ester, and is stirred at a rotation speed of 3500 to 5000 rpm for 15 to 25 minutes to emulsify. In addition, the dyeability is greatly improved, and the acid dye is refined, so that the permeability to hair is improved. Therefore, the same dyeability can be obtained even when the amount of the acid dye is less than 0.02% by weight, which is less than 2/5 of the conventional dye. Therefore, since the amount of the dye is small, even if the dye adheres to hands or clothes, it can be easily removed.
Furthermore, when a moisturizing component is added, the damage to the hair is reduced, and the permeability of the dye is improved, so that the amount of the acid dye can be further reduced.

Claims (3)

In purified water, a hair styling base, an acid for pH adjustment, and an acid hair dye containing an acid dye,
The acid dye is adjusted to 0.02% by weight or less, and α-hydroxy acid ester (excluding malic acid diester) is added at 2% by weight or more. An acidic hair dye. In addition to the acid dye and the α-hydroxy acid ester (excluding malic acid diester), a moisturizing component is further added, and the mixture is emulsified by stirring at a rotation speed of 3500 to 5000 rpm for 15 to 25 minutes. The acidic hair dye according to claim 1, which is used. After adding a hairdressing base, 0.02% by weight or less of an acid dye, and 2% by weight or more of α-hydroxy acid ester (excluding malic acid diester) to purified water, the acid for pH adjustment is added. A method for producing an acidic hair dye, wherein the pH is adjusted, and then the mixture is put into a vacuum homomixer and stirred at a rotation speed of 3500 to 5000 rpm for 15 to 25 minutes to emulsify.