CN108697605B

CN108697605B - Photosensitive hair dye

Info

Publication number: CN108697605B
Application number: CN201680081465.1A
Authority: CN
Inventors: 庆野哲雄; 井坂谦二
Original assignee: Yawu Le Co ltd
Current assignee: Yawu Le Co ltd
Priority date: 2016-02-17
Filing date: 2016-11-16
Publication date: 2021-09-14
Anticipated expiration: 2036-11-16
Also published as: JP2017145212A; CN108697605A; TWI658838B; WO2017141509A1; KR20180044357A; TW201729792A; JP6164543B1

Abstract

The present invention addresses the problem of providing a photosensitive hair dye that can be stored for a long period of time and has excellent stability. The solution is to provide a photosensitive hair dye comprising an aqueous solution in which a silver salt and N-acetylmethionine are dissolved, 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

Technical Field

The invention relates to a photosensitive hair dye.

Background

The photosensitive hair dye develops color by causing silver ions to be photo-reduced and precipitated fine particles of metallic silver to be adsorbed on the surface of hair. The photosensitive hair dye is widely adopted by the market due to the following advantages: can be made into cream, gel, lotion, etc.; simply colored by being applied to hair and bathing in sunlight or the like; the hair dye can be maintained for 1-2 months and does not contain diamine derivatives which cause allergy or hair damage.

The photosensitive hair dye develops color by metallic silver fine particles generated by photo-reduction of silver ions. Therefore, the photosensitive hair dye requires an aqueous silver salt solution in which silver salt is dissolved in water to form silver ions. Silver nitrate is known as a silver salt that is easily soluble in water. Silver nitrate is a pharmaceutical raw material and cannot be used in cosmetics in japan. Silver sulfate, silver lactate, silver citrate, and silver oxide are known as silver salts that can be used as cosmetic raw materials.

Patent document 1 proposes a hair dye containing (a) 1 or 2 or more silver salts selected from silver sulfate, silver lactate, and silver citrate, and (b) a chelating agent. The present inventors have also proposed a hair dye sensitive composition which combines silver sulfate and citric acid and has excellent coloring properties (patent document 2), a hair dye sensitive composition which is a mixture of silver sulfate and an alkanolamine (patent document 3), and a hair dye sensitive composition which contains silver oxide and an amino acid (patent document 4).

The photosensitive hair dye requires that the hair to which the photosensitive hair dye is applied is exposed to light so that silver ions are converted into silver particles through a photo-reduction reaction. Although the light exposure time can be shortened by increasing the reactivity of silver ions, a high reactivity means low stability. Therefore, when the reactivity of silver ions is improved, a reduction reaction proceeds in the light-shielding tube even if light is not irradiated, and the photosensitive hair dye is blackened, which may result in a decrease in hair dyeing property. In addition, it is also considered to increase the silver ion concentration in order to shorten the light exposure time, but silver sulfate, silver lactate, and silver citrate are poorly soluble, and silver oxide is insoluble, and therefore cannot be dissolved in water at a high concentration. Further, when the silver salt is dissolved to the vicinity of the upper limit of the solubility, the stability may be lowered, and the silver may precipitate to blacken the photosensitive hair dye, thereby lowering the hair dyeing property.

In addition, although the conventional photosensitive hair dye can darken by repeated hair dyeing, the color tone of the photosensitive hair dye is reddish brown. Since a reddish hue is not preferred, a hue that is lighter in red and darker can be adjusted by blending a sulfur powder (colloidal sulfur) in the sensitizing hair dye. However, there is a problem that the sulfur odor is strong when the hair is used and the sulfur odor attached to the hair cannot be removed even by repeated shampooing.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2011-116708

Patent document 2: japanese patent No. 3881688

Patent document 3: japanese patent No. 4542621

Patent document 4: japanese patent No. 5486106

Disclosure of Invention

The present invention addresses the problem of providing a photosensitive hair dye that can be stored for a long period of time and has excellent stability.

1. A photosensitive hair dye comprising an aqueous solution in which a silver salt and N-acetylmethionine are dissolved, wherein the molar ratio of N-acetylmethionine to silver atoms, i.e., N-acetylmethionine/silver, dissolved in said aqueous solution is less than 4.5 mol.

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

3. The photosensitive hair dye according to 1 or 2, wherein the concentration of the silver salt in the aqueous solution is 1.6wt% or more.

4. The photosensitive hair dye according to any one of claims 1 to 3, wherein the formulation is any one of a lotion, a nutrient solution, a gel, a cream, an emulsion, a mousse, a hairdressing gel, a hair conditioner and a shampoo.

The silver ions in the photosensitive hair dye of the present invention can form a stable complex, and thus can be stored for a long period of time in a light-shielding tube or the like, and the hair dyeing property does not decrease even after storage. In particular, the photosensitive hair dye of the present invention using silver sulfate as a silver salt is excellent in storage stability at low temperatures and high temperatures.

The photosensitive hair dye of the present invention can control the silver salt concentration in a wider range than conventional photosensitive hair dyes, and can adjust the time of application to hair and the light exposure time according to the silver salt concentration. The photosensitive hair dye with high silver salt concentration can shorten the time for applying the dye to hair and the light exposure time, reduce the burden on the user and can be used conveniently. The light-sensitive hair dye with a low silver salt concentration can gradually darken the hair by repeated use, thereby inhibiting the change of the impression caused by hair dyeing.

The photosensitive hair dye of the present invention can be used for dyeing hair by bathing in the sun or under the light of an illumination machine in daily life only in a state of being applied to hair or after being applied to hair and shampooed. Therefore, the photosensitive hair dye of the present invention can be used daily as a hair cream, a conditioner, a shampoo, etc. without performing any special action. By using the hair dye composition of the present invention every day or every few days or so, the hair of the newly grown part can be gradually dyed, so that the vicinity of the hair root is not whitened and natural black hair can be maintained.

The photosensitive hair dye can dye hair into brown without red without matching with sulfur. The photosensitive hair dye without sulfur does not emit sulfur odor, and perfume can be easily used to increase fragrance.

Drawings

Fig. 1 is a photograph showing the results of dyeing human white hair with the sensitizing hair dye having different silver sulfate concentrations in experiment 1.

FIG. 2 is a photograph showing the results of dyeing human white hair with the sensitizing hair dye having different silver sulfate concentrations in experiment 1.

FIG. 3 is a photograph showing the results of dyeing human white hair with the hair dye composition in experiment 2, in which the molar ratio of N-acetylmethionine to silver atoms in silver sulfate is different.

Detailed Description

The photosensitive hair dye of the present invention comprises an aqueous solution in which a silver salt and N-acetylmethionine are dissolved.

Silver salts are themselves poorly soluble or insoluble and have low solubility in water. The concentration of silver in the aqueous solution can be increased by dissolving a silver salt together with N-acetylmethionine to form a water-soluble complex of silver atoms with N-acetylmethionine.

As the silver salt, any one or two or more of silver sulfate, silver lactate, silver citrate, and silver oxide can be used. Silver sulfate is particularly preferable because of its excellent storage stability. The lower limit of the concentration of the silver salt in the aqueous solution is 0.01 wt% or more, preferably 0.1 wt% or more, more preferably 1.0 wt% or more, further preferably 1.6wt% or more, and most preferably 2.0 wt% or more. The higher the silver salt concentration, the shorter the application time and the light exposure time can dye the hair. The upper limit of the concentration of the silver salt in the aqueous solution varies depending on the type of the silver salt, but the silver salt is soluble to a saturation concentration at which the silver salt is dissolved to form a complex.

N-acetylmethionine exists in optical isomers of L-form and D-form. As N-acetyl methionine, can use N-acetyl L-methionine, N-acetyl D-methionine and as a mixture of N-acetyl-DL-methionine any one. The concentration of N-acetylmethionine in the aqueous solution is 0.01 wt% or more and 50 wt% or less. The dissolution time of the silver salt can be shortened by increasing the amount of N-acetylmethionine. Even if N-acetylmethionine is more than 50 wt%, the dissolution time of silver salt is hardly changed, and it exceeds the solubility of N-acetylmethionine in water and is recrystallized together with insoluble substance to solidify.

The molar ratio of N-acetylmethionine to silver atoms in the aqueous solution (N-acetylmethionine/silver) is preferably in the range of 0.05 to less than 4.5 mol. If the amount of N-acetylmethionine is less than 0.05 mole per 1 mole of silver atom, a complex cannot be formed, and thus the silver salt is difficult to dissolve. The dissolution time of the silver salt can be shortened by increasing the amount of N-acetylmethionine, but if the amount of N-acetylmethionine is 4.5 mol or more based on 1 mol of silver atom, the hair dyeing property is lowered. This is a common phenomenon of silver sulfate, silver lactate, silver citrate, and silver oxide.

The complex of silver and N-acetylmethionine can be prepared by simply adding silver salt and N-acetylmethionine to water and stirring to dissolve them. The stirring may be performed at room temperature, but the temperature may be increased to about 40 to 80 ℃ when the silver salt is hardly dissolved. In this case, even if insoluble components remain, the hair dye can be used as a sensitizing hair dye as long as a liquid component is present, but from the viewpoint of dyeing properties, it is preferable that the silver salt and N-acetylmethionine are completely dissolved.

The complex composed of silver and N-acetylmethionine is very stable in an aqueous solution, and even if the aqueous solution in which the complex is dissolved is irradiated with light, the complex is not broken and silver particles are not precipitated. In addition, even if the aqueous solution is applied to a plastic and irradiated with light, the color does not change immediately. However, when the aqueous solution is applied to hair and irradiated with light, silver particles are immediately precipitated and develop color. That is, the photosensitive hair dye of the present invention comprising an aqueous solution in which a silver salt and N-acetylmethionine are dissolved can be stably stored in a container such as a plastic container, and can rapidly develop color when applied to hair and bathed in light, and has extremely excellent properties as a photosensitive hair dye.

The reason why the light sensitive hair dye of the present invention containing a complex composed of silver and N-acetylmethionine is excellent in storage stability and hair dyeing property is presumed as follows.

The complex of silver ions is stable to light, and for example, even when an aqueous solution in which a silver-ammonia complex or a complex of silver and sodium thiosulfate is dissolved is irradiated with light, silver particles are not precipitated and the aqueous solution is not blackened. The complex composed of silver and N-acetylmethionine is not blackened even when an aqueous solution thereof is irradiated with light. However, in the complex, since N-acetylmethionine is coordinated by weak interaction with silver ions, when strong negative charges are approached as in the hair surface, the silver ions (Ag +) in the complex are attracted to the hair surface and the complex is disintegrated, so that the silver ions are adsorbed on the hair surface. Since silver ions adsorbed to hair do not form a complex and are low in stability, they can be easily reduced by light to develop a color.

Therefore, the photosensitive hair dye of the present invention can be stably stored in a container such as plastic, which has a weak or no electric charge, and can be applied to hair and dyed in light by bathing, and is excellent in both stability and hair dyeing properties.

Further, stabilization of the complex composed of silver and N-acetylmethionine is greatly related to the concentration of N-acetylmethionine. When the molar ratio of N-acetylmethionine to silver atoms (N-acetylmethionine/silver) is 4.5 mol or more, the complex is stabilized, and is not easily broken even when exposed to light on hair, and thus the hair dyeing property is lowered.

The hair dye composition of the present invention can be used not only for dyeing hair by a method of exposing the hair dye composition to sunlight, illumination light, or the like in a state of being applied to the hair, but also for dyeing hair by a method of washing the hair dye composition by applying the hair dye composition to the hair and then exposing the hair dye composition to sunlight, or the like. This is because silver ions are strongly adsorbed to hair, and a sufficient amount of silver ions are generally adhered to the hair surface after shampooing.

Since the method of applying the photosensitive hair dye to hair, washing the hair, and exposing the hair to sunlight or the like has a short elapsed time in a state of being applied to hair, it can be easily utilized and thus has a small burden on a user, and it is possible to reduce coloring of clothes or the like by reducing the photosensitive hair dye attached to clothes or the like.

The photosensitive hair dye of the present invention can control the silver salt concentration in a wide concentration range, and can dye hair into a deep color tone as the silver salt concentration increases. The photosensitive hair dye of the present invention having a silver salt concentration of 1.6wt% or more can be dyed a brown color without reddening without substantially containing sulfur. Here, the fact that sulfur is not substantially contained means that the content of sulfur is 0.1 wt% or less.

The photosensitive hair dye of the present invention can shorten the time for applying to hair and the light exposure time as the concentration of silver salt in the aqueous solution increases. The photosensitive hair dye of the present invention having a high silver salt concentration has a short application time and a short light exposure time, and thus has a small burden on the user. The photosensitive hair dye of the present invention having a low silver salt concentration does not dye a deep color tone in a single use, but gradually dyes hair into a deep color tone by divided applications. In addition, since the hair can be gradually changed to a dark color, the change in impression due to the coloring of the hair can be suppressed.

The photosensitive hair dye of the present invention may suitably contain a surfactant, an oil agent, a thickener, a humectant, a preservative, an antioxidant, a pH adjuster, a perfume, a coloring agent, other cosmetic ingredients, a medicinal ingredient, and the like, which are generally used, as a component to be blended in a cosmetic or hair dye, within a range that does not destroy a complex composed of silver and N-acetylmethionine. These components are preferably mixed after the silver salt and N-acetylmethionine are dissolved in water to form a complex.

The photosensitive hair dye of the present invention comprises an aqueous solution in which a silver salt and N-acetylmethionine are dissolved, and can be prepared into an aqueous cosmetic, or an emulsion-type cosmetic such as a W/O emulsion, an O/W emulsion, a W/O/W emulsion, or an O/W/O emulsion.

The photosensitive hair dye of the present invention can be prepared into, for example, a lotion, a nutrient solution, a gel, a cream, an emulsion, a mousse, a hair treatment, a hair conditioner, a shampoo, and the like. By using the photosensitive hair dye of the present invention in the above formulation at a level of once a day to once a week, the newly born portion of hair can be gradually dyed. By using the hair dye regularly, the vicinity of the hair root is not whitened, so that it is difficult to find white hair dyeing and natural black hair can be maintained.

The photosensitive hair dye is also suitable for a hair conditioner or a shampoo which is daily applied to hair and is easy to wash. The photosensitive hair dye of the present invention has excellent stability, and when the photosensitive hair dye is filled in a bottle or the like, silver particles do not precipitate and the hair dyeing property does not decrease even when the photosensitive hair dye is left in a bathroom where the temperature changes from about 20 ℃ to 40 ℃ for a long period of time.

The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Examples

"experiment 1"

An aqueous solution was prepared by mixing a silver salt and N-acetylmethionine according to the composition shown in Table 1 below. The values of the mixing ratios shown in table 1 are mass%. Further, since it is difficult to analyze the composition of the insoluble component, the molar ratio (N-acetylmethionine/silver) was calculated from the compounding ratio. The solubility, color tone and dyeing time of the obtained aqueous solution were evaluated. Further, as N-acetylmethionine, N-acetyl-DL-methionine is used.

(solubility)

Very good: water dissolved at room temperature.

Good: dissolved in water at 80 ℃.

Insolubilization: the insoluble matter remained without being completely dissolved in water at 80 ℃.

And (3) curing: the insoluble components solidify and no liquid components are present.

(color tone)

Each aqueous solution was uniformly applied to human hair, and the color tone after exposure to sunlight for 15 minutes and washing with running water in a clear day was visually confirmed. In the case of curing, the same operation was performed except that the cured product was attached to human hair. Fig. 1 and 2 show the results of dyeing white hair using silver sulfate.

(dyeing time)

Each aqueous solution was uniformly applied to white hair, exposed to sunlight on a sunny day, and the time until the hair was dyed in a uniform color tone without mottle was measured.

TABLE 1

The silver salts each show a different solubility. Silver sulfate and silver lactate have excellent solubility, and can be dissolved in the solution by 20 wt%. Silver citrate can be dissolved by 8 wt%, and silver oxide can be dissolved by 6 wt%. At a concentration higher than this, the silver salt is saturated and insoluble components remain.

In either silver salt, hair can be dyed to a darker shade as the silver salt concentration is thickened from 0.1 wt% to 2 wt%. Further, when the silver salt concentration is 2 wt% or more, substantially the same color tone can be obtained unless insoluble components remain, and particularly, when the silver salt concentration is 4 wt% or more, a difference in color tone cannot be observed. Even if insoluble components remain, the silver salt in the solution adsorbs to the hair, and thus the hair can be dyed, but the dyeing property is lowered. In addition, when solidification occurs, hair cannot be dyed even if it adheres to hair.

The dyeing time also becomes shorter as it goes from 0.1 wt% to 2 wt%. When the silver salt concentration is 2 wt% or more, hair can be dyed uniformly with one fifth of the light irradiation time, as compared with the case where the silver salt concentration is 1.0 wt%. If insoluble components remain, the dyeing time is increased.

The influence of the kind of silver salt on the color tone and dyeing time is hardly observed.

"experiment 2"

Similarly to experiment 1, aqueous solutions were prepared by mixing the components shown in the following table 2, and the solubility, color tone and dyeing time of the obtained aqueous solutions were evaluated. The values of the mixing ratios shown in Table 2 are% by mass. The result of dyeing the white hair in the example using silver sulfate is shown in fig. 3. Further, as N-acetylmethionine, N-acetyl-DL-methionine is used.

TABLE 2

Silver sulfate	2.0	2.0	2.0	4.0	4.0	4.0
							N-acetylmethionine	2.5	10.0	11.0	5.0	20.0	22.0
Purified water	95.5	88.0	87.0	91.0	76.0	74.0
							Molar ratio of	1.01	4.04	4.50	1.01	4.04	4.50
Solubility in water	Is very good	Is very good	Is very good	Is very good	Is very good	Good taste
							Color tone	Very dark brown	Brown colour	Not to color	Very dark brown	Brown colour	Not to color
Dyeing time	3 minutes	15 minutes	-	3 minutes	15 minutes	-

Silver lactate	2.0	2.0	2.0	4.0	4.0	4.0
							N-acetylmethionine	1.9	7.5	8.4	3.8	15.0	16.8
Purified water	96.1	90.5	89.6	92.2	81.0	79.2
							Molar ratio of	1.01	4.02	4.50	1.01	4.02	4.50
Solubility in water	Is very good	Is very good	Is very good	Is very good	Is very good	Good taste
							Color tone	Very dark brown	Brown colour	Not to color	Very dark brown	Brown colour	Not to color
Dyeing time	3 minutes	15 minutes	-	3 minutes	15 minutes	-

Citric acid silver salt	2.0	2.0	2.0	4.0	4.0	4.0
							N-acetylmethionine	2.3	9.0	10.2	4.6	18.0	20.4
Purified water	95.7	89.0	87.8	91.4	78.0	75.6
							Molar ratio of	1.02	4.00	4.50	1.02	4.00	4.50
Solubility in water	Is very good	Is very good	Is very good	Is very good	Is very good	Good taste
							Color tone	Very dark brown	Brown colour	Not to color	Very dark brown	Brown colour	Not to color
Dyeing time	3 minutes	15 minutes	-	3 minutes	15 minutes	-

Silver oxide	2.0	2.0	2.0	4.0	4.0	4.0
							N-acetylmethionine	3.4	13.3	14.9	6.8	26.6	29.8
Purified water	94.6	84.7	83.1	89.2	69.4	66.2
							Molar ratio of	1.03	4.02	4.50	1.03	4.02	4.50
Solubility in water	Is very good	Is very good	Is very good	Is very good	Is very good	Good taste
							Color tone	Very deepBrown colour	Brown colour	Not to color	Very dark brown	Brown colour	Not to color
Dyeing time	3 minutes	15 minutes	-	3 minutes	15 minutes	-

The solubility of either composition is excellent, and an aqueous solution free from insoluble components can be obtained.

In either silver salt, a molar ratio of either about 1 or about 4 can be used to dye hair, particularly dark shades when the molar ratio is about 1. On the other hand, if the molar ratio is 4.5, the hair cannot be dyed even with an aqueous solution in which the silver salt and N-acetylmethionine are completely dissolved.

"experiment 3"

As examples 1 to 4 and comparative examples 1 to 3, hair care milks having the compositions shown in Table 3 below were prepared. The values of the mixing ratios shown in Table 3 are% by mass. The preparation process is as follows. Further, as N-acetylmethionine, N-acetyl-DL-methionine is used.

Silver salt and N-acetylmethionine or L-methionine are added to purified water and dissolved by stirring. Then, the remaining ingredients were all added, heated to 70 ℃ and stirred uniformly, and then cooled to room temperature.

Evaluation of sensitive Hair dyes

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

(1) Property of dyeing hair

After 0.5g of the prepared hair care cream was uniformly applied to human white hair for 1 time, it was exposed to sunlight for 15 minutes in a sunny day. Thereafter, the hair dyeing property was evaluated by the color tone after rinsing for 1 minute.

Very good: very dark brown

O: dark brown

And (delta): light brown

(2) Appearance and shape

About 75g of the prepared hair cream was packed in a lightproof ointment container (125 ml, manufactured by Marshall chemical Co., Ltd.), and left at room temperature. The cap is opened once a day, and the peculiar smell, the color change and the viscosity change are observed by visual observation within 60 days.

Very good: almost unchanged for 60 days

And (delta): the odor, viscosity, and color of cream were not greatly changed, but the sweet and sour taste peculiar to some amino acids was felt

X: the odor, discoloration and viscosity change can be observed

(3) Stability of

About 75g of the prepared hair cream was packed in a light-shielding ointment container (125 ml, manufactured by Marshall chemical Co., Ltd.), and placed in a thermostatic bath set at 5 ℃ and 45 ℃. The cap is opened once a day, and the peculiar smell, the color change and the viscosity change are observed by visual observation within 60 days.

Very good: almost unchanged for 60 days

O: no off-odor or discoloration was observed, but slight change in viscosity was observed as compared with the storage at room temperature

And (delta): no discoloration was observed, but the sweet and sour taste characteristic of amino acids was slightly perceived, while a change in viscosity was found

X: the odor, discoloration and viscosity change can be observed

TABLE 3

Examples 1 to 4, which are the photosensitive hair dye of the present invention, are excellent in hair dyeing properties. In addition, even when the sample was left at room temperature for 60 days, the change was hardly observed. In particular, in example 1 using silver sulfate, no change was observed even when it was left at 5 ℃ for 60 days at 45 ℃.

Comparative examples 1 to 3 using L-methionine had hair dyeing property immediately after preparation, but deteriorated at room temperature, 5 ℃ and 45 ℃ and poor storage stability. Comparative example 2 using silver lactate had a methionine off-odor and a lactic acid sweet off-odor, and the cream also changed to a slightly gray color. Comparative example 3 using silver citrate generated the off-odor of methionine and the cream also changed to black. Comparative example 1 using silver sulfate had superior preservability as compared with comparative examples 2 and 3, but the off-odor of methionine occurred.

Claims

1. A photosensitive hair dye comprising an aqueous solution in which a silver salt and N-acetylmethionine are dissolved, wherein the molar ratio of N-acetylmethionine to silver atoms, N-acetylmethionine/silver, dissolved in the aqueous solution is less than 4.5, the concentration of the silver salt in the aqueous solution is 1.6 to 20wt%, and the silver salt comprises silver sulfate.

2. The photosensitive hair coloring agent of claim 1, wherein said silver salt is silver sulfate alone.

3. The photosensitive hair dye according to claim 1 or 2, wherein the formulation is any one of a nutrient solution, a gel, a cream, a lotion, a mousse, a hair treatment gel, a hair conditioner, and a shampoo.