JP2019182774A - Photosensitive hair dye - Google Patents

Abstract

To provide a cosmetic that can dye the hair quickly, uniformly and efficiently, without damaging the hair or skin, and also has good long-term storage stability in a container for a cosmetic product, and exhibits good dyeability.SOLUTION: A photosensitive hair dye is an aqueous solution in which a silver salt, in the form of one or more of silver sulfate, silver lactate, and silver citrate, at a rate of 0.01% to 5.0%, and a phosphoric acid of 0.01% to 15.0% are dissolved therein.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a hair dyeing method using a photosensitive hair dye that develops color when irradiated with light. More specifically, the present invention uses a photosensitive hair dye containing a silver salt, and is capable of dyeing hair quickly, with good long-term stability, and uniformly and efficiently without damaging the background and hair. About.

  The photosensitive hair dye develops color when silver ions are reduced by light and the precipitated silver fine particles are adsorbed onto the hair surface. Photosensitive hair dyes can be made into various dosage forms such as creams and lotions, which are common cosmetics, can be easily dyed just by being exposed to sunlight, etc., and can maintain the hair dyed state for 1 to 2 months. It is accepted in the market because it does not contain a diamine derivative, which is a component of an oxidative hair dye that tends to cause contact allergies and hair damage.

  The photosensitive hair dye is colored by silver fine particles generated by photoreduction of silver ions. For the photosensitive hair dye, an aqueous silver salt solution containing silver ions is essential. Silver nitrate is known as a silver salt that dissolves easily in water. However, since silver nitrate is a pharmaceutical product, it cannot be used for cosmetics. Silver salts that can be widely used as cosmetics include silver sulfate, silver lactate, silver citrate, and silver oxide.

  The photosensitive hair dye needs to expose the hair coated with the photosensitive hair dye to light to convert silver ions into silver particles by a photoreduction reaction. In order to shorten the light exposure time and to dye uniformly and efficiently, the concentration of silver ions can be increased, but silver sulfate, silver lactate, and silver citrate are insoluble and silver oxide is insoluble and highly soluble in water. It cannot be dissolved at a concentration. Further, when the silver salt is dissolved to near the upper limit of the solubility, the stability is lowered, silver is precipitated, the photosensitive hair dye is blackened, and the hair dyeing property may be lowered.

Japanese Patent No. 6164543 Patent 5486106

  The present invention relates to a photosensitive hair which can quickly and uniformly dye hair and has long-term storage stability.

1. A photosensitive hair dye comprising an aqueous solution in which 0.01% to 5.0% silver salt and 0.01% to 15% phosphoric acid are dissolved.
2. The silver salt is any one of silver sulfate, silver lactate and silver citrate, or two or more thereof. The photosensitive hair dye described in 1.
3. 1. The dosage form is one of lotion, tonic, gel, cream, emulsion, or mousse. ~ 2. The photosensitive hair dye as described in any of 1.

In the photosensitive hair dye of the present invention, silver ions form a stable complex with phosphoric acid and can be stored for a long time. In particular, the photosensitive hair dye of the present invention using silver sulfate as a silver salt is excellent in storage stability even at low and high temperatures.
Compared with conventional photosensitive hair dyes, the photosensitive hair dye of the present invention can control the concentration of silver salt in a wide range. Depending on the concentration of silver salt, the time applied to the hair and the light exposure time can be controlled. Can be adjusted. A photosensitive hair dye having a high silver salt concentration can shorten the time to be applied to the hair and the light exposure time, reduce the burden on the user, and can be used conveniently. By repeatedly using a photosensitive hair dye having a low silver salt concentration, the color tone of the hair can be gradually increased, and the change in impression due to the hair dye can be suppressed.

  The photosensitive hair dye of the present invention can be used for hair dyeing while being applied to hair, or after being applied to hair and washed, and then exposed to sunlight or light from lighting equipment while living daily. Therefore, the photosensitive hair dye of the present invention can be used daily as a hair cream or the like without taking any special action. By using the photosensitive hair dye of the present invention every day or every few days, the newly grown part can be gradually dyed, so that natural black hair can be maintained.

In Experiment 1, the photograph which shows the result of having dyed gray human hair using the photosensitive hair dye from which silver salt differs. In Experiment 2, the photograph which shows the result of having dyed gray human hair using the photosensitive hair dye from which the density | concentration of phosphoric acid and silver sulfate differs.

The photosensitive hair dye of the present invention contains an aqueous solution in which a silver salt and phosphoric acid are dissolved.
The silver salt itself is hardly soluble or insoluble and has low solubility in water. By dissolving the silver salt together with phosphoric acid, the silver atom and phosphoric acid form a water-soluble complex, and the silver concentration in the aqueous solution can be increased.

  As the silver salt, any of silver sulfate, silver lactate, silver citrate, or two or more kinds can be used. Silver sulfate is preferred because it is particularly excellent in storage stability. The lower limit of the silver salt concentration in the aqueous solution is 0.01 wt% or more, preferably 0.5 wt% or more, more preferably 1.0 wt% or more, further preferably 1.5 wt% or more, and 2.0 wt% or more. Most preferred. The higher the silver salt concentration, the more the hair can be dyed even if the application time and light exposure time are short. The upper limit of the silver salt concentration in the aqueous solution varies depending on the type of silver salt, but can be dissolved up to a saturation concentration at which a complex is formed and dissolved.

  The phosphoric acid concentration in the aqueous solution is 0.01 wt% or more and 15.0 wt% or less. The silver salt concentration in the aqueous solution is 0.01 wt% or more and 5.0 wt% or less. Phosphoric acid can shorten the time for the silver salt to dissolve by increasing the amount of the phosphoric acid. Even if phosphoric acid is added more than 15.0 wt%, the dissolution time and solubility of the silver salt hardly change. Moreover, even if it mixes 5.0 wt% or more of silver salt, the dark color tone of hair and the time dye | stained by the color tone do not change.

  A complex composed of a silver salt and phosphoric acid is stable in an aqueous solution, and even if light is irradiated to an aqueous solution in which the complex is dissolved, the complex does not collapse and silver particles do not precipitate, so the color does not change. A complex composed of a silver salt and phosphoric acid is an important condition for maintaining a stable pH of 2 to 3. Phosphoric acid is a stable substance and does not self-decompose. Therefore, PH in the aqueous solution is stabilized and PH is maintained at 2 to 3. Therefore, the complex exists stably and does not self-decompose such as hydrolysis and is excellent in long-term stability. It also has excellent stability in the container without generating off-flavors.

  The photosensitive hair dye of this invention can shorten the time applied to hair, and the light exposure time, as the silver salt concentration in aqueous solution becomes high. Further, when the silver salt concentration is high, the hair can be dyed in a deep color tone. For this reason, the change of the impression by having dyed hair can be adjusted.

The photosensitive hair dye of the present invention is a surfactant, oil agent, thickener, and humectant generally used as a cosmetic or hair dye compounding component as long as the complex of silver salt and phosphoric acid is stable. Preservatives, antioxidants, pH adjusters, fragrances, colorants, other cosmetic ingredients, medicinal ingredients, and the like can be appropriately blended.
The photosensitive hair dye of the present invention contains an aqueous solution in which a silver salt and phosphoric acid are dissolved, and is an aqueous cosmetic, or a W / O emulsion, an O / W emulsion, a W / O / W type. It can be set as the emulsion type cosmetics which are an emulsion and an O / W / O type | mold emulsion.

  The photosensitive hair dye of the present invention can be made into dosage forms such as lotions, tonics, gels, creams, emulsions, mousses, hair treatments, rinses, shampoos and the like. By using the photosensitive hair dye of the present invention as the above-mentioned dosage form from about every day to about once a week, newly grown parts can be gradually dyed. By using it regularly, it does not become white only near the root of the hair, so it is difficult to understand that the hair is dyed, and natural black hair can be maintained.

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

“Experiment 1”
As Examples 1 to 3, gels having the compositions shown in Table 1 below were prepared. The value of the blending ratio shown in Table 1 is mass%. The preparation procedure is as follows.
Various silver salts and phosphoric acid are added to purified water and dissolved by stirring. Next, all the remaining components are added, heated to 70 ° C., stirred until uniform, and then cooled to room temperature.

(1) Evaluation of hue The prepared gel was evaluated according to the following criteria. The results are shown in Table 1.
(Color tone)
0.2 g of each gel was evenly applied to gray human hair, exposed to sunlight under fine weather for 15 minutes, and visually checked for color tone after washing with running water. FIG. 1 shows the result of dyeing gray human hair in an example using silver sulfate.
◎: very dark brown ○: dark brown △: light brown (dyeing time)
0.2 g of each gel was uniformly applied to human white hair, exposed to sunlight under fine weather, and the time until the hair was dyed in a uniform color with no unevenness was measured.

(2) Appearance and shape About 40 g of the prepared gel was packed in a light-shielding ointment container (50 ml ointment container completely shielded from light with an aluminum hole) and left at room temperature. Once a day, the lid was opened, and the off-flavor, discoloration, and viscosity change were visually observed for 60 days.
A: Almost no change for 60 days, maintaining 3 from PH2 ○: Odor and discoloration are not observed, but a slight change in viscosity is observed compared with storage at room temperature, and the pH changes from 3 in PH2.
(3) Stability About 40 g of the prepared gel was packed in a light-shielding ointment container (a 50 ml ointment container completely shielded from light with an aluminum hole) and left in a thermostatic bath set at 5 ° C and 45 ° C. Once a day, the lid was opened, and the off-flavor, discoloration, and viscosity change were visually observed for 60 days.
◎: Almost no change for 60 days ○: Odor and discoloration are not observed, but a slight change in viscosity is observed compared with storage at room temperature

In any silver salt, it was possible to produce a deep color and dyeing could be done in as little as 3 minutes. Also, the appearance, shape and stability were good.

"Experiment 2"
As Examples 4 to 8, gels having the compositions shown in Table 2 below were prepared. The value of the blending ratio shown in Table 2 is mass%.
Add silver sulfate and phosphoric acid to purified water and stir to dissolve. Next, all the remaining components are added, heated to 70 ° C., stirred until uniform, and then cooled to room temperature.

(1) Evaluation of hue The prepared gel was evaluated according to the following criteria. The results are shown in Table 1.
(Color tone)
0.2 g of each gel was evenly applied to gray human hair, exposed to sunlight under fine weather for 15 minutes, and visually checked for color tone after washing with running water. FIG. 1 shows the result of dyeing gray human hair in an example using silver sulfate.
◎: very dark brown ○: dark brown △: light brown (dyeing time)
0.2 g of each gel was uniformly applied to human white hair, exposed to sunlight under fine weather, and the time until the hair was dyed in a uniform color with no unevenness was measured.

(2) Appearance and shape About 40 g of the prepared gel was packed in a light-shielding ointment container (50 ml ointment container completely shielded from light with an aluminum hole) and left at room temperature. Once a day, the lid was opened, and the off-flavor, discoloration, and viscosity change were visually observed for 60 days.
A: Almost no change for 60 days, maintaining 3 from PH2 ○: Odor and discoloration are not observed, but a slight change in viscosity is observed compared with storage at room temperature, and the pH changes from 3 in PH2.
(3) Stability About 40 g of the prepared gel was packed in a light-shielding ointment container (a 50 ml ointment container completely shielded from light with an aluminum hole) and left in a thermostatic bath set at 5 ° C and 45 ° C. Once a day, the lid was opened, and the off-flavor, discoloration, and viscosity change were visually observed for 60 days.
◎: Almost no change for 60 days ○: Odor and discoloration are not observed, but a slight change in viscosity is observed compared with storage at room temperature

Examples 6, 7, and 8 were excellent in hue. Examples 4 and 5 were slightly inferior in hue. As for dyeing time, Examples 6, 7, and 8 dyed in a short time, but in Examples 1 and 2, the dyeing time was slightly longer than 15 minutes. In terms of appearance and stability, even if it was allowed to stand for 60 days from Examples 4 to 8, almost no change was observed.

Claims (3)

  A photosensitive hair dye comprising an aqueous solution in which 0.01% to 5.0% of silver salt and 0.01% to 15.0% of phosphoric acid are dissolved and dissolved in the aqueous solution.   The photosensitive hair dye according to claim 1, wherein the silver salt is any one of silver sulfate, silver lactate, and silver citrate, or two or more thereof. The photosensitive hair dye according to claim 1, wherein the dosage form is any one of lotion, tonic, gel, cream, milky lotion, and mousse.

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