JP3881688B2 - Hair dye and method for producing the same - Google Patents

Description

  The present invention relates to a hair dye that can be easily dyed and a method for producing the same.

  First, there are temporary hair dyes for temporarily coloring the hair, such as color sprays and color sticks. In addition, there are semi-permanent hair dyes that use ionic bonds between hair proteins and acid dyes, which are called hair manicures, color rinses, and color treatments, and oxidative hair dyes that are typified by hair colors, hair dyes, and white hair dyes. Recently, there is a tendency that an oxidative hair dye is preferred due to high durability of the dyed color (see Patent Document 1).

  The oxidative hair dye is, for example, a first liquid in which an alkaline agent such as ammonia is added to an oxidative dye such as paraphenylene diamine or toluene-2.5-diamine, and a second oxidant such as hydrogen peroxide. It is composed of liquid. In use, the two liquids are mixed just before hair is dyed, and the mixed liquid is applied to the hair. In hair dyeing with an oxidative hair dye, the oxidative dye that has penetrated into the hair undergoes oxidative polymerization with the added oxidant, and an insoluble pigment is formed by the oxidative polymerization, and the insoluble pigment produced is fixed in the hair. The hair is dyed.

  On the other hand, hair dyes that use silver salts such as silver nitrate, silver lactate, sparingly soluble silver sulfate, and silver acetate and that are dyed by light reaction or oxidation have also been proposed (see Patent Documents 2 and 3). In addition, a hair dyeing method using two liquids in which ammonia silver complex salt or ethanolamine silver complex salt solution is attached to hair and then dyed with a reducing agent has also been proposed (see Patent Document 4). Moreover, the hair dyeing method using ethanolamine silver complex salt and diamine type dye is also proposed (refer patent document 5).

The applicant has not yet found prior art documents related to the present invention by the time of filing other than the prior art documents specified by the prior art document information described in this specification.
JP-A-10-175830 JP 2002-348221 A JP-A-52-125638 JP-A-48-018438 Japanese Patent Laid-Open No. 4-31514

  However, the above-mentioned oxidative hair dye needs to mix two liquids immediately before use, and thus takes time and has a problem such as an ammonia odor. In addition, oxidative dyes made of diamine-based substances and this polymer can cause carcinogenicity, liver damage, effects on the health of the human body, such as effects on the fetus, and hair damage caused by alkalis and oxidation reactions. Has been pointed out.

In addition, those using silver salts are very unstable in silver salt aqueous solution, so if left in a container, they will naturally color black, and the ability to adhere to hair and the fastness of the attached state will be reduced. There are problems such as lowering.
The present invention has been made to solve the above-described problems, and an object of the present invention is to make it possible to more easily and stably dye hair.

In order to solve the above-described problems, the hair dye according to the present invention is such that silver sulfate and citric acid are mixed with a substrate material having moisture.
Therefore, the hair dye contains silver sulfate, which is a silver salt that is reduced by irradiation with ultraviolet rays or visible light to deposit metallic silver, in an aqueous solution state.
Further, the method for producing a hair dye according to the present invention is such that silver sulfate is added to an aqueous solution in which citric acid is dissolved, so that silver sulfate and citric acid are mixed with a substrate material having moisture. is there.
Therefore, the hair dye can be produced without the silver salt being precipitated.

As described above, in the present invention, the hair dye contains a silver salt that is reduced by ultraviolet irradiation or the like to precipitate metallic silver in a water-soluble state made acidic with citric acid. Therefore, hair can be dyed only by applying the hair dye to the hair. Moreover, since it is set as the acidic area | region using a citric acid, it is suppressed that it oxidizes by dark reaction etc., and the state which silver sulfate melt | dissolved stably is obtained.
As described above, according to the present invention, hair can be easily dyed, for example, it is not necessary to mix the two liquids immediately before use. There is no odor of ammonia, and there is no effect on the health of the human body or hair damage due to alkali or oxidation reaction.

Embodiments of the present invention will be described below.
The hair dye of the present embodiment makes a predetermined substrate material having moisture acidic with citric acid, and mixes (adds) silver sulfate, which is a water-soluble silver salt, to the substrate material to make it acidic with citric acid. Silver sulfate is dissolved in the prepared substrate material. The substrate material may be an emulsion in which an oil component is emulsified in a water-soluble component. The substrate material may be a gel in which a polymer material is dispersed in a predetermined dispersion medium, or an aqueous solution containing alcohol.

  When the hair dye is applied to the hair and irradiated with light such as ultraviolet rays or visible light, the silver ions dissolved in the hair dye are reduced to metal silver, and the reduced metal silver fine particles are added to the hair. Colored by depositing on the surface. In the hair dyed in this way, no change in the coloring state of the hair is confirmed in normal hair washing. The metallic silver deposited by the light irradiation and adhering to the surface of the hair is considered to be strong that does not separate from the surface of the hair during hair washing or the like.

Silver sulfate (Ag ₂ SO ₄ ) is a white solid with a molecular weight of 311.79, has low solubility in water, is 0.8% at 20 ° C., and is slightly improved in the acidified state and presence of alcohol. To do. For example, the solubility is improved to about 0.9% by setting the acid state.
When the concentration of the dissolved silver salt is as low as about 0.4 to 0.6%, the hair becomes colored with redness. For example, when applied to gray hair, when the silver salt concentration is about 0.4 to 0.6%, the hair is dyed from pink to reddish brown, and not so dark brown. However, when the subject of hair dyeing is a woman, light brown may be preferred, and the color tone may be adjusted to some extent by the silver salt concentration.

In order to obtain an acidic state, an acid may be added. For example, strong acids such as sulfuric acid and nitric acid are not suitable for hair dyes used for the human body. Also, hydrochloric acid cannot be used because it produces silver chloride.
In contrast to the strong acid described above, the weak acid has no influence on the human body and does not form a salt, so it is suitable as a material to be added to make it acidic. However, for example, acetic acid is not suitable as a material to be added to the hair dye because it has a strong odor.

In contrast to the above knowledge, citric acid, malic acid, lactic acid, glycolic acid and the like do not cause the above-described problems as materials for making them acidic.
When these materials were investigated, it was confirmed that when silver sulfate was added to a substrate material acidified with malic acid, lactic acid, glycolic acid, or the like, it gradually colored during production or over time. Depending on the acid used, precipitates were confirmed after production.

On the other hand, when an acidic region was formed using citric acid, a state in which silver sulfate was dissolved in a stable state was obtained without causing coloring. In addition, when citric acid is used, the solubility of silver sulfate can be increased to 0.9%. Here, it goes without saying that sodium citrate may be used as a buffering agent.
In addition, the silver salt aqueous solution is very unstable, but as described above, by adding citric acid to make it an acidic region, a stable state can be obtained and the dark reaction of blackening by standing can be suppressed. become.

When citric acid is not used, blackening gradually proceeds even when stored in a dark place, and the ability and fastness to adhere to the hair decrease.
On the other hand, in the hair dye in this Embodiment, since it was made to be pH 4.0 or less with citric acid, the oxidation of the dissolved silver salt is suppressed, without combining with reducing substances such as sulfur, Generation of black silver oxide can be suppressed. For example, even if the hair dye is stored at a high temperature of 40 ° C. or higher, coloring (dark reaction) does not occur. However, it is necessary to add silver sulfate in a state where citric acid has been added in advance. Even if citric acid is added after silver sulfate is dissolved, no effect is obtained.

  On the other hand, when it is not made acidic by citric acid and is in the alkaline region, silver ions are gradually oxidized when left at room temperature (for example, 20 to 25 ° C.) even if light is blocked. As a result, silver oxide is formed and gradually becomes black. In this case, when sulfur is added as a reducing agent, the dark reaction can be suppressed even in the alkaline region. However, when sulfur is added in the alkaline region, the reactivity (sensitivity) to light is lowered.

  In addition, even if silver sulfate is about 0.5-0.9% of dissolution amount, if it is aqueous solution, the hair dyeing state mentioned above will be obtained. However, in a state where silver ions are hardly generated, for example, in a state where silver sulfate is dispersed in an oil component, the reaction by light is very slow and the above-described hair dyeing effect cannot be obtained.

Next, the manufacturing method of the hair dye mentioned above is demonstrated.
First, the product A is prepared using the following components.
In a vacuum emulsification pot, add 81.4 kg of purified water and heat to 90 ° C., add citric acid to make it acidic, add 0.6 kg of silver sulfate, and stir to add silver sulfate. Dissolve to make Product A. Here, an equivalent amount of sodium citrate may be added as a buffering agent.

Next, the following components are mixed to prepare a product B.
In an oil tank kettle, 12 kg of silicone oil, 4 kg of cetanol, 1.5 kg of sorbitan stearate, 0.3 kg of stearyldimethylammonium chloride and 0.1 kg of methylparaben are stored and heated to 80 ° C. to dissolve them. And

  Next, the product A stored in the vacuum emulsification kettle is kept at 80 ° C., and this is vigorously stirred. The product B is gradually added to the stirred state. Next, after all the product B is added to the product A, the vacuum emulsification pot is sealed to create a reduced pressure environment. After the reduced pressure environment, the contents of the vacuum emulsification pot are stirred for 8 minutes by a 3000 rpm homomixer, and then the temperature of the contents is cooled to 35 ° C. while the stirring speed is reduced.

Finally, the emulsion obtained by mixing the product A and the product B as described above is filtered through a 20-mesh filter to obtain 98 kg of white cream (hair dye).
These preparations are performed in a state where light is almost blocked so that there is no precipitation of metallic silver due to reduction.

  The resulting white / creamy hair dye has a pH of about 4. When this hair dye is allowed to stand at room temperature with light blocked, it is stable without being blackened for more than 10 months. Moreover, even if this hair dye is left in a state of 40 ° C. while blocking light, it is stable without blackening for 6 months or more.

Next, the hair dyeing action of the hair dye of the present invention described above will be described in more detail.
The hair dye of the present invention is obtained, for example, by mixing a water-soluble silver salt of silver sulfate with a substrate material having moisture such as a hair cream. When such a hair dye is applied to the hair and the hair is exposed to sunlight (ultraviolet rays) in this state, the silver ions in the hair dye are reduced by light and metal silver is deposited, and the deposited metal silver adheres to the hair. To do. Thus, the metal silver is deposited and adhered to the hair, so that the hair is dyed. Part of the metallic silver deposited on the hair reacts with sulfur in the hair and changes to black silver sulfide, or is gradually oxidized by oxygen in the air and changes to black silver oxide. Is also expected.

  The hair dye of the present invention is prepared by mixing silver as a silver salt for dyeing hair as a silver salt and applying it to the hair in a state dissolved in water, that is, in a state of water-soluble silver ions. As a result, according to the hair dye of the present invention, the silver is easily penetrated into the hair, and since the metal silver fine particles are deposited in the state of contact with the hair surface or inside the hair, the color is fixed. It is easy. Moreover, since it does not contain diamine or lead, it does not cause allergic reactions or harm health. Furthermore, according to the hair dye of the present invention, the protective effect of hair by coating the surface of the hair with metallic silver can be expected, and of course, the hair is not damaged.

According to the hair dye of the present invention described above, the hair at the stage where the hair dye is applied is not in a dyed state, but at the stage where silver ions in the hair dye are deposited as reduced metallic silver. The hair is dyed.
In the above description, the hair dye is prepared by dissolving silver sulfate in an emulsion base material. However, the present invention is not limited to this. For example, a hair dye may be obtained by dissolving silver sulfate in a base material that is a gel in which a polymer material is dispersed in a predetermined dispersion medium.

  For example, 0.6 kg of silver sulfate is dissolved in 82.1 kg of purified water, 0.1 kg of citric acid and 0.1 kg of sodium citrate, and 0.5 kg of carboxyvinyl polymer and 0.5 kg of polyvinyl pyrrolidone derivative quaternary ammonium salt are added thereto. Further, 0.8 kg of triisopropanolamine, 14.0 kg of ethanol, 0.8 kg of polyoxyethylene lauryl ether (23E · O) and 0.5 kg of ethyl paraben may be added to obtain a transparent gel to be used as a hair dye. Needless to say, this hair dye is also manufactured in a state where light is almost blocked so that metallic silver is not precipitated by reduction.

An aqueous solution in which a predetermined fragrance is dissolved may be used as the substrate material.
When a milky liquid is used as the substrate material, it is generally referred to as a hair cream, and when a gel is used as the substrate material, it is generally referred to as a hair gel. In addition, when an aqueous solution is used as the substrate material, it is referred to as a hair lotion, and when a highly viscous emulsion is used as the substrate material, it is referred to as a hair wax. Moreover, these hair dyes can be provided as, for example, a so-called hair mousse (registered trademark) in the form of a cream filled in a spray can.
Moreover, 0.01 to 0.50% of colloidal sulfur may be added to the hair dye. By adding and mixing colloidal sulfur, the coloring by the hair dye becomes darker.

Claims (6)

A substrate material having moisture;
A hair dye comprising silver sulfate and citric acid mixed with the substrate material. In the hair dye according to claim 1,
A hair dye comprising colloidal sulfur mixed in the substrate material. In the hair dye according to claim 1,
The hair dye characterized in that the substrate material is a milky liquid in which an oil component is emulsified in a water-soluble component. In the hair dye according to claim 1,
The hair dye characterized in that the matrix material is a gel in which a polymer material is dispersed in a predetermined dispersion medium. In the hair dye according to claim 1,
The hair dye characterized in that the substrate material is an aqueous solution. A method for producing a hair dye comprising a substrate material having moisture, and silver sulfate and citric acid mixed in the substrate material,
A method for producing a hair dye, comprising adding silver sulfate to an aqueous solution in which citric acid is dissolved.