TW201729792A - Photosensitive hair dye - Google Patents

Abstract

The present invention addresses the problem of providing a photosensitive hair dye which has excellent stability and can be stored for a long period of time. Provided, as a means for solving the problem, is a photosensitive hair dye which includes an aqueous solution having a silver salt and N-acetylmethionine dissolved therein, wherein the molar ratio of N-acetylmethionine to silver atoms (N-acetylmethionine/silver) dissolved in the aqueous solution is less than 4.5 mol.

Description

Photosensitive hair dye

This invention relates to a hair dye, and more particularly to a photosensitive hair dye.

The photosensitive hair dye is reduced by light by silver ions, and the precipitated metal silver fine particles are adsorbed on the surface of the hair to develop color. The photosensitive hair dye can be made into various dosage forms such as cream, gel, lotion, etc., and can be simply dyed as long as it is applied to the hair and bathed in sunlight, and the hair dyeing state can be maintained. It has been widely adopted in the market for one to two months and does not contain the advantages of diamine derivative, which causes allergy or hair damage.

The photosensitive hair dye is colored by the metallic silver fine particles generated by photoreduction of silver ions. Therefore, the photosensitive hair dye requires a silver salt aqueous solution in which silver salt is dissolved in water to form silver ions. As a silver salt which is easily soluble in water, silver nitrate is well known. Since silver nitrate is a raw material for pharmaceuticals, it cannot be used in cosmetics in Japan. As a silver salt which can be used as a raw material for cosmetics, silver sulfate, silver lactate, silver citrate, and silver oxide are well known.

Patent Document 1 proposes a hair dye comprising (a) one or more silver salts selected from the group consisting of silver sulfate, silver lactate and silver citrate; and (b) a chelating agent . In addition, the present inventors have proposed a photosensitive hair dye which combines silver sulfate and citric acid and has excellent coloring property (Patent Document 2), a mixed silver sulfate and an alkanolamine. A photosensitive hair dye (Patent Document 3), a photosensitive hair dye containing silver oxide and an amino acid (Patent Document 4).

The photosensitive hair dye needs to expose the hair using the photosensitive hair dye to light to reduce the silver ions to silver particles by a photoreduction reaction. Although the light exposure time can be shortened as long as the reactivity of the silver ions is increased, the high reactivity means low stability. Therefore, once the reactivity of the silver ions is increased, there is a possibility that the reduction reaction proceeds in the tube which is not irradiated with light, and the photosensitive hair dye gradually becomes black, resulting in a decrease in hair dyeability. Further, in order to shorten the light exposure time, a means for increasing the concentration of silver ions has been conceived. However, silver sulfate, silver lactate, and silver citrate have poor solubility, and silver oxide is insoluble, so that it cannot be dissolved in water at a high concentration. Further, when the silver salt is dissolved to the upper limit of the solubility, the stability may be lowered, and the photosensitive hair dye may be blackened by precipitation of silver, resulting in a decrease in hair dyeability.

In addition, the conventional photosensitive hair dye can dye and deepen the color by repeated use, but the color tone will be brown with a brown color. Since the reddish-brown color tone is not widely used, a sulfur meal (colloid sulfur) is added to the photosensitive hair dye to reduce the redness and adjust to a blackish hue. However, it faces a strong sulphur odor when used, and even if the shampoo is repeated, the problem of sulfur odor remaining on the hair cannot be removed.

[Patent Literature]

[Patent Document 1] JP-A-2011-116708

[Patent Document 2] Patent No. 3881688

Patent Document 3: Patent No. 4546261

Patent Document 4: Patent No. 5486106

In view of the above, an object of the present invention is to provide a photosensitive hair dye which has excellent stability and can be stored for a long period of time.

To achieve the above and other objects, the present invention provides a photosensitive hair dye as follows:

A photosensitive hair dye comprising: an aqueous solution, a solute of a silver salt and N-acetyl methionine, dissolved in the aqueous solution of N-acetyl methionine and a silver atom The molar ratio (N-acetamidine/silver) is less than 4.5 moles.

2. The photosensitive hair dye according to Item 1, wherein the silver salt is any one or two or more of silver sulfate, silver lactate, silver citrate, and silver oxide.

3. The photosensitive hair dye according to Item 2, wherein the concentration of the silver salt in the aqueous solution is 1.6% by weight or more.

4. The photosensitive hair dye according to Item 1, wherein the concentration of the silver salt in the aqueous solution is 1.6% by weight or more.

5. The photosensitive hair dye according to any one of the items 1 to 4, wherein the dosage form is a lotion, a tonic, a gel, a cream, an emulsion, a mousse, a care Any of hair treatment, rinse, and shampoo.

The photosensitive hair dye of the present invention is a complex compound in which silver ions are formed into a stable form, and can be stored in a light-shielding tube for a long period of time, and the hair dyeability does not decrease after storage. In particular, the photosensitive hair dye of the present invention is used as a silver salt using silver sulfate, and has excellent storage stability at low temperatures and high temperatures.

The photosensitive hair dye of the present invention can have a silver salt concentration as compared with a conventional photosensitive hair dye. The control is in a wide range, and the time used for hair and the exposure time of light can be adjusted according to the concentration of silver salt. The photosensitive hair dye having a high silver salt concentration can be used in a simple manner by shortening the time of use of the hair and the light exposure time, and reducing the burden on the user. The photosensitive hair dye having a low silver salt concentration can gradually deepen the color tone of the hair after repeated use, and can reduce the visual sensation caused by hair dyeing.

The photosensitive hair dye of the present invention can be used for dyeing hair while being used in hair or after shampooing after use, and can be dyed by bathing in sunlight or under the light of a lighting machine. Therefore, the photosensitive hair dye of the present invention can be used as a hair cream, a conditioner, a shampoo, etc., and can be used every day without special behavior. By using the photosensitive hair dye of the present invention every day or every few days, the hair of the new part can be gradually dyed, so that the hair is not whitened near the hair root, and natural black hair can be maintained.

The photosensitive hair dye of the present invention can dye the hair into a reddish brown color without sulphur. A photosensitive hair dye containing no sulfur component does not emit a sulfur odor, and it is easy to use a fragrance to add aroma.

The above and other objects, features, and advantages of the present invention will become more apparent and understood.

Fig. 1 is a photograph showing the results of hair dyeing of a human white hair bundle with a photosensitive hair dye having a different silver sulfate concentration in Experiment 1.

Fig. 2 is a photograph showing the results of hair dyeing of a human white hair bundle with a photosensitive hair dye having a different silver sulfate concentration in Experiment 1.

Fig. 3 is a photograph showing the results of hair dyeing of a human white hair bundle with a photosensitive hair dye having a different molar ratio between silver atoms in N-acetamidine and silver sulfate in Experiment 2.

The photosensitive hair dye of the present invention comprises an aqueous solution containing a silver salt and N-acetyl methionine.

The silver salt itself is poorly soluble or insoluble and has low solubility in water. By dissolving the silver salt together with N-acetamidine thioglycolate, the silver atom and N-acetamidine thioglycolate form a water-soluble complex, which can increase the concentration of silver in the aqueous solution.

Any one or two or more of silver sulfate, silver lactate, silver citrate, and silver oxide may be used as the silver salt. Silver sulfate is preferred because of its excellent preservation stability. The lower limit of the concentration of the silver salt in the aqueous solution is 0.01% by weight or more, preferably 0.1% by weight or more, more preferably 1.0% by weight or more, more preferably 1.6% by weight or more, and most preferably 2.0% by weight or more. The higher the concentration of silver salt, the shorter the time of use and the shorter the light exposure time, the hair can be dyed. The upper limit of the concentration of the silver salt in the aqueous solution may be different depending on the type of the silver salt, but it may be dissolved to a saturated concentration which is dissolved by the formation of the complex.

N-acetyl methionine has optical isomers of L and D. N-acetyl-L-methionine, N-acetamidine-D-methionine and mixtures thereof can be used as N-acetamidine-DL-methionine One is used as N-acetyl methionine. The concentration of N-acetyl methionine in the aqueous solution is 0.01% by weight or more and 50% by weight or less. The dissolution time of the silver salt can be shortened by increasing the amount of N-acetyl methionine. Even if N-acetamidine methionine is set to be more than 50% by weight, the dissolution time of the silver salt hardly changes, and exceeds the solubility of N-acetyl methionine relative to water, and recrystallizes together with the insoluble matter. Further solidified.

Mohr ratio between N-acetamidine and silver atoms in aqueous solution (N-B The methionine/silver) is preferably in the range of 0.05 or more and less than 4.5 moles. If the N-acetamidine methionine is less than 0.05 mol with respect to 1 mol of the silver atom, the complex compound cannot be formed, and the silver salt will be difficult to dissolve. Although the dissolution time of the silver salt can be shortened by increasing the amount of N-acetyl methionine, if the N-acetamidine methionine is 4.5 mol or more with respect to 1 mol of the silver atom, Hair dyeability will decrease. This is a common phenomenon of silver sulfate, silver lactate, silver citrate, and silver oxide.

The complex formed by silver and N-acetyl methionine can be completed by adding a silver salt and N-acetyl methionine to water and stirring and dissolving it. Stirring can also be carried out at room temperature, but in the case where the silver salt is difficult to dissolve, it can be heated to a temperature of 40 to 80 °C. In this case, even if there is a residual insoluble matter, it can be used as a photosensitive hair dye as long as a solvent is present. However, in terms of dyeability, it is preferred to completely dissolve silver and N-acetyl methionine.

In the aqueous solution, the complex formed by silver and N-acetyl methionine is very stable, and even if the aqueous solution containing the complex is irradiated with light, the complex does not collapse and the silver particles are not precipitated. In addition, even if the aqueous solution is coated on a plastic and irradiated with light, the color does not change immediately. However, when this aqueous solution is applied to the hair and irradiated with light, silver particles are precipitated immediately to develop color. That is, the photosensitive hair dye of the present invention containing an aqueous solution in which a silver salt and a N-acetyl methionine are dissolved can be stably stored in a container such as a plastic, and once applied to the hair and bathed in the light, it is fast. The color of the ground is extremely excellent in terms of the photosensitive hair dye.

The reason why the photosensitive hair dye of the present invention containing a complex compound formed by silver and N-acetyl methionine has excellent storage stability and hair dyeability is presumed to be as follows: a complex of silver ions, relative to The light is stable, for example, in an aqueous solution of a silver ammine complex or a complex of silver and sodium thiosulfate, the silver particles are not precipitated even after light irradiation, and the aqueous solution is not Will be blackened. Silver and N-acetamidine The complex formed by the acid does not blacken even in the aqueous solution even if it is irradiated with light. However, in the complex, the interaction between N-acetyl methionine and silver ions is weak, like the surface of the hair, if the strong minus charge is close, the complex Silver ions (Ag+) are pulled to the surface of the hair, causing the complex to collapse and silver ions adsorbing on the surface of the hair. The silver ions that have been adsorbed on the hair do not form a complex, and because of their low stability, they can be easily reduced by light to develop color.

Therefore, the photosensitive hair dye of the present invention can be safely stored in a container having a weak or no charge such as a plastic, and can be dyed by applying it to the hair and bathing in the light, and the stability and hair dyeability are excellent. .

In addition, the stability of the complex formed by silver and N-acetyl methionine is strongly correlated with the concentration of N-acetyl methionine. The molar ratio (N-acetamidine/silver) between N-acetamidine and silver atoms can stabilize the complex as long as it is above 4.5 mol, even on the hair. The light also becomes less likely to be disintegrated and the hair dyeability will decrease.

The photosensitive hair dye of the present invention is not only a method of exposing sunlight or illumination light or the like while being applied to the hair, but also can be used by shampooing the hair, rinsing off the photosensitive hair dye, and then exposing it to the sun. The method of light or the like can also dye the hair. This is due to the strong adsorption of silver ions on the hair, so after the usual shampoo, there will be a sufficient amount of silver ions attached to the surface of the hair. A method in which a photosensitive hair dye is applied to hair and shampooed, and then exposed to sunlight or the like, because the time spent on the hair is short, so that it can be easily used, and the burden on the user is small, and It is inadvertent to reduce the color of the photosensitive hair dye attached to clothing and the like while leaving it in clothing.

The photosensitive hair dye of the invention can control the concentration of silver salt in a wider concentration The range of degrees, as the concentration of silver salt increases, can dye the hair in rich shades. The photosensitive hair dye of the present invention having a silver salt concentration of 1.6% by weight or more can dye the hair to a reddish brown color without containing substantial sulfur. The term "sulphur-free" as used herein means that the content of sulfur is 0.1% by weight or less.

The photosensitive hair dye of the present invention can shorten the time used for hair and the light exposure time as the concentration of the silver salt in the aqueous solution increases. The photosensitive hair dye of the present invention having a high silver salt concentration has a small burden on the user due to the use time and short exposure time. The photosensitive hair dye of the present invention having a low silver salt concentration does not dye a rich color tone in a single use, but can be gradually dyed into a rich color tone by being applied in plural times. In addition, since the hair can gradually become a rich color tone, the visual discomfort caused by the hair dye can be reduced.

The photosensitive hair dye of the present invention can be used in combination with commonly used surfactants, oils, tackifiers, humectants, etc., within the range of not dissolving the complex formed by silver and N-acetyl methionine. Preservatives, antioxidants, pH adjusters, perfumes, coloring materials, other cosmetic ingredients, medicinal ingredients, etc., as a component of a cosmetic or hair coloring agent. These components are preferably mixed in a silver salt and N-acetamidine methionine in water to form a complex. The photosensitive hair dye of the present invention comprises an aqueous solution containing a silver salt and N-acetyl methionine, which can be made into an aqueous cosmetic, or a W/O emulsion, and an O/W emulsion. Emulsified cosmetics such as liquid, W/O/W emulsion, O/W/O emulsion.

The photosensitive hair dye of the present invention can be prepared, for example, as a lotion, a nutrient solution, a gel, a cream, an emulsion, a mousse, a hair care essence, a moisturizing essence, a shampoo, and the like. When the photosensitive hair dye of the present invention is used in the form of the above-mentioned dosage form, once a day to once a week, the hair of the new part can be gradually dyed. By regular use, since only the hair roots are nearby It does not turn white, and it is difficult to find black hair that is dyed in white hair and can maintain nature.

The photosensitive hair dye of the present invention is suitable for daily use on hair, and is also convenient for use in a rinser or shampoo which is easy to rinse. The photosensitive hair dye of the present invention has excellent stability, and in a state of being filled in a bottle or the like, even if it is left in a bathroom whose temperature is changed from 20 ° C to 40 ° C for a long period of time, silver particles are not precipitated, and hair dyeability is also Will not fall.

Next, the present invention will be specifically described based on examples, but the present invention is not limited thereto.

"Experiment 1"

The silver salt and N-acetyl methionine were mixed in accordance with the composition ratios shown in Table 1 to prepare an aqueous solution. The compounding ratio values shown in Table 1 are mass percentages. Further, since it is difficult to analyze the component ratio of the insoluble matter, the molar ratio (N-acetamidine/silver) was calculated from the mixing ratio. The solubility, color tone, and dyeing time of the obtained aqueous solution were evaluated. Further, N-acetamidine-DL-methionine was used as N-acetyl methionine.

(solubility)

Very good: water dissolved in room temperature.

Good: water dissolved at 80 °C.

Insoluble: water that is not completely dissolved in 80 ° C, residual insoluble.

Curing: Insoluble curing, solvent is not present.

(tone)

Each of the aqueous solutions was uniformly applied to a human white hair bundle, and after exposure to sunlight for 15 minutes on a sunny day, it was washed with running water, and the color tone was visually confirmed. Also, in the experiment of testing solubility, the knot If the cured product is formed, the same experimental operation is carried out except that the cured product is attached to the human white hair bundle. Fig. 1 and Fig. 2 show the results of hair dyeing of human white hair bundles in the example using silver sulfate.

(staining time)

Each of the aqueous solutions was uniformly applied to a human white hair bundle, and exposed to sunlight on a sunny day to measure the time until the hair was dyed into a uniform color tone.

Each of the silver salts showed a different solubility. Among them, silver sulfate and silver lactate have the most excellent solubility, and can be dissolved to 20% by weight. Silver citrate can be dissolved up to 8 wt%, and silver oxide can be dissolved up to 6 wt%. When the dissolved concentration reaches more than these, the silver salt will be saturated and the insoluble matter remains. In any of the silver salts, the hair can be dyed to a richer hue as the silver salt concentration is increased from 0.1 wt% to 2 wt%. Further, as long as the concentration of the silver salt is not more than 2% by weight in the concentration range of no residual insoluble matter, the hair can be dyed to have almost the same color tone, and in particular, when the concentration of the silver salt is 4% by weight or more, the difference in color tone cannot be considered. Even if the insoluble matter remains, since the silver salt in the solution is adsorbed on the hair, although the hair can be dyed, the dyeability is lowered. Further, in the case where a cured product is produced, the hair cannot be dyed even if it adheres to the hair.

The dyeing time also became shorter as it became from 0.1 wt% to 2 wt%. When the silver salt concentration is 2% by weight or more, the hair dyeing can be uniformly performed with one-fifth of the light irradiation time as compared with the case where the silver salt concentration is 1.0% by weight. If there is no insoluble residue, the dyeing time will become longer.

It is almost impossible to identify the influence of color tone and dyeing time caused by the type of silver salt.

"Experiment 2"

In the same manner as in Experiment 1, the composition ratios shown in Table 2 were mixed to prepare an aqueous solution, and the solubility, color tone, and dyeing time of the obtained aqueous solution were evaluated. The values of the mixing ratios shown in Table 2 are mass percentages. In Fig. 3, the results of staining human white hair bundles with silver sulfate are shown. Further, N-acetamidine-DL-methionine was used as N-acetyl methionine.

Any of the compositions has excellent solubility, and an insoluble solution can be obtained.

In any of the silver salts, hair dyeing can be carried out by any of the molar ratios of about 1, or about 4. In particular, the molar ratio is about one, and the hair can be dyed to a rich color. On the other hand, when the molar ratio is 4.5, the hair cannot be dyed even though the aqueous solution of the silver salt and N-acetyl methionine is completely dissolved.

"Experiment 3"

The ingredients shown in the preparation list 3 were compared with the hair creams of Examples 1 to 4 and Comparative Examples 1 to 3. The values of the mixing ratios shown in Table 3 are mass percentages. The preparation process is as follows. Further, N-acetamidine-DL-methionine was used as N-acetyl methionine.

Silver salt and N-acetamidine or L-methionine are added to the purified water and stirred to dissolve. Subsequently, the remaining components were all added, warmed to 70 ° C and stirred until uniform, and then left to cool at room temperature.

Evaluation of photosensitive hair dyes

The prepared hair care cream was evaluated according to the following criteria. The results are shown in Table 3.

(1) Hair staining

Using a human white hair bundle, 0.5 g of the prepared hair cream was uniformly applied once, and exposed to sunlight on a sunny day for 15 minutes. Thereafter, hair dyeability was evaluated based on the color tone after 1 minute of rinsing.

◎: dark brown

○: thick brown

△: light brown

(2) Appearance and shape

Approximately 75 g of the prepared hair care cream was placed in a light-shielding ointment container (manufactured by Mazen Chemical Container Co., Ltd., capacity: 125 ml), and left at room temperature. Open the lid once a day, and observe the presence of odor, discoloration, and viscosity changes by visual observation within 60 days.

◎: almost no change in 60 days

△: Although there is no big change in the color of the odor, viscosity, and cream, it feels the sweet and sour taste unique to the amino acid.

×: odor, discoloration, viscosity change can be detected

(3) Stability

Approximately 75 g of the prepared hair care cream was placed in a light-shielding ointment container (manufactured by Mazen Chemical Container Co., Ltd., capacity: 125 ml), and placed in a thermostat set at 5 ° C and 45 ° C. Open the lid once a day, and observe the presence of odor, discoloration, and viscosity changes by visual observation within 60 days.

◎: almost no change in 60 days

○: Although the odor and discoloration were not detected, a slight change in viscosity was observed compared with the storage at room temperature.

△: Although the discoloration was not observed, the sweet and sour taste characteristic of the amino acid was slightly felt, and the viscosity change was observed.

×: odor, discoloration, viscosity change can be detected

In Examples 1 to 4 of the photosensitive hair dye of the present invention, hair dyeability was excellent. In addition, even when left at room temperature for 60 days, almost no change was observed. In particular, in Example 1 using silver sulfate, no change was observed even when it was left at 5 ° C and 45 ° C for 60 days. In Comparative Examples 1 to 3 in which L-methionine was used, although it had hair dyeing properties immediately after preparation, it deteriorated under any conditions of room temperature, 5 ° C, and 45 ° C, and the storage stability was inferior. In Comparative Example 2 in which silver lactate was used, the odor of methionine and the sweet and sour odor of lactic acid occurred, and the cream also changed to a slightly grayish color. In Comparative Example 3 in which silver citrate was used, the odor of methionine occurred, and the cream also changed to black. In Comparative Example 1 in which silver sulfate was used, although it was more excellent in storage stability than Comparative Examples 2 and 3, the odor of methionine was generated.

While the invention has been described above by way of a preferred embodiment, it is not intended to limit the invention, and it is intended to be within the scope of the invention. . Therefore, the scope of the invention is defined by the scope of the appended claims.

Claims (5)

A photosensitive hair dye comprising: an aqueous solution containing a silver salt and N-acetamidine thioglycolic acid, and a molar ratio between N-acetamidine and silver atoms dissolved in the aqueous solution (N- Ethyl methionine/silver) is less than 4.5 moles. The photosensitive hair dye according to the first aspect of the invention, wherein the silver salt is any one or two or more of silver sulfate, silver lactate, silver citrate, and silver oxide. The photosensitive hair dye according to claim 2, wherein the concentration of the silver salt in the aqueous solution is 1.6% by weight or more. The photosensitive hair dye according to claim 1, wherein the concentration of the silver salt in the aqueous solution is 1.6% by weight or more. The photosensitive hair dye according to any one of claims 1 to 4, wherein the dosage form is a lotion, a nutrient solution, a gel, a cream, an emulsion, a mousse, a hair care essence, a conditioner Any of a fine, shampoo.