JP2012121810A - Organic compound composite powder having ultraviolet absorbing ability, method for producing the same, and cosmetic preparation containing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite powder having an ultraviolet absorbing ability by uniformly coating the surface of a powder serving as the base with an ultraviolet absorber, particularly, an organic ultraviolet absorber, and a cosmetic preparation containing the powder and having high safety.SOLUTION: The surface of a pigment powder as a fine particle powder selected from titanium oxide and/or zinc oxide is uniformly coated with an organic ultraviolet absorber having low solubility to a medium such as butyl methoxydibenzoylmethane and/or hexyl diethylaminohydroxybenzoyl benzoate in a state of being close to a monomolecular membrane by using an organic solvent having high solubility.

Description

The present invention relates to a composite powder having an ultraviolet shielding ability, particularly an excellent ultraviolet shielding ability even at a wavelength of 320 to 400 nm called A-wave, and a cosmetic containing them.
The present invention also relates to a method for producing a composite powder, characterized in that a surface of a powder serving as a substrate is coated with an organic compound having an ultraviolet absorbing ability.

In recent years, in cosmetics such as skin cosmetics and makeup cosmetics, pigments are used for the purpose of coloring and toning, providing lubricity and gloss, etc., especially cosmetics that prevent erythema and sunburn due to ultraviolet rays. Many developed cosmetics such as sunscreen agents and foundations are widely used.
As powders used in these cosmetics, metal oxides such as fine particle titanium oxide and fine particle zinc oxide include powders having an ultraviolet scattering effect, and are often used in cosmetics for preventing sunburn. The display method of SPF and PFA, which are ultraviolet ray shielding ability indexes, has been reviewed globally, and in particular, in recent years, the need for UV-A (A wave ultraviolet ray) shielding has been greatly increased. It is known that inorganic UV shielding agents including not only fine particle titanium oxide but also fine zinc oxide have a low UV-A shielding ability, so that the use of inorganic ultraviolet light blocking agents is limited.

On the other hand, an ultraviolet absorber made of an organic compound typified by butylmethoxydibenzoylmethane has an excellent UV-A shielding ability, but is poorly soluble in a medium used in cosmetics, and has a high It is difficult to formulate, and there are problems such as re-precipitation and crystallization even if blended, and there is a drawback that it is difficult to use in cosmetic formulations.
Therefore, attempts have been made to pulverize organic UV absorbers and blend them in cosmetics so that they can be handled easily in cosmetic formulations. However, the efficiency of UV absorption is higher in the powder type compared to the solution type. The powder type was overwhelmingly inferior to the solution type in terms of UV shielding ability when using the same amount in cosmetics.
For example, cosmetics using a titanium oxide pigment in combination with an organic ultraviolet absorber (Patent Document 1, L'Oreal) Rakan fruit extract (momordica grosbenori fruit) and an external preparation using an organic ultraviolet absorber in combination (Patent Document 2, Kose), External preparations containing powders surface-treated with benzoylmethane-based organic ultraviolet absorbers and silicone compounds (Patent Document 3, Shiseido), external preparations using specific biphenyl compounds in combination with organic ultraviolet absorbers (Patent Documents) 4, Kanebo), but these technologies coexist organic UV absorbers and their auxiliary components when blended into cosmetics, etc., and do not improve dispersion of organic UV absorbers themselves. There wasn't.

  As a technique for improving the dispersibility of a slightly powder type organic ultraviolet absorber, there is an ultraviolet absorbing pigment formed by bonding an organic ultraviolet absorber to the surface (Patent Document 5, Noevir). The dispersibility of the ultraviolet absorbent-treated powder was not satisfactory.

  As mentioned above, in the past, it has been known that the use of powdered organic UV absorbers is highly useful for ease of handling when blended into cosmetics. There was no organic UV absorber with good dispersibility.

Japanese Patent Laid-Open No. 9-2929 JP-A-10-182406 Japanese Patent Laid-Open No. 10-265357 Japanese Patent No. 3632348 JP-A-5-194932

Cosmetics containing UV absorbers are used outdoors and during periods of high UV irradiation, so there are safety issues such as phototoxicity and cumulative irritation of UV absorbers. Making the same effect in a small amount is a major economic issue.
In view of the above situation, the present invention includes an organic compound composite powder having a shielding ability equal to or higher than that in the case where the organic ultraviolet absorber is dissolved, even if a medium in which the organic ultraviolet absorber is not dissolved, and blending them. It is an object to provide a finished cosmetic.

In general, ultraviolet absorbers are more efficient in terms of quantitative use than are used as powders, but are sometimes difficult to dissolve in media. Often seen.
As ultraviolet absorbers, butyl methoxydibenzoylmethane and diethylaminohydroxybenzoyl hexyl benzoate are widely used as organic ultraviolet absorbers. However, these organic ultraviolet absorbers are difficult to dissolve in the medium and are temporarily dissolved. However, the compound does not become stable in the long term, and the compound may precipitate.
When used in cosmetics, if it is difficult to dissolve in the medium, the ultraviolet absorber must be used as a powder.
In addition, inorganic pigments used in cosmetics themselves cover the skin surface and can suppress the transmission of ultraviolet rays to some extent, but titanium oxide, zinc oxide, etc. have an ultraviolet scattering effect and are used for sun protection. Although it is used in cosmetics, in order to increase the covering property, in order to obtain a sufficient UV scattering effect, these pigments must be mixed in a considerably large amount, and the toning may not be successful, There was an adverse effect such as generation and worsening of makeup.

  The present invention provides a means for integrating and combining these organic ultraviolet absorbers that are difficult to dissolve stably and powders such as pigments, in the case of combining an inorganic powder serving as a base material and the above ultraviolet absorber. By coating the surface of the inorganic powder with the organic ultraviolet absorber and handling it as a powder, the organic ultraviolet absorber can be used as a single substance dissolved in an appropriate medium and used at least as much as the ultraviolet shielding ability. A composite powder of an organic ultraviolet absorber having the above-mentioned properties is obtained, and by combining the organic ultraviolet absorber composite powder thus obtained in cosmetics, a makeup having an ultraviolet shielding ability higher than expected. The present invention has been found out to be a charge.

  That is, in the present invention, butylmethoxydibenzoylmethane or the like is used for fine particles of titanium oxide, fine zinc oxide, and talc, mica, sericite, etc., which are generally used as inorganic ultraviolet shielding agents. An organic ultraviolet absorber composite powder can be obtained by subjecting an organic ultraviolet absorber having low solubility in a medium such as silicone used in cosmetics to a surface coating treatment using an organic solvent having high solubility. it can.

  The basis for this will be explained in the examples described later. In the present invention, it is considered that the surface of the powder is uniformly coated with an organic ultraviolet absorber in a state close to a monomolecular film. Accordingly, by uniformly dispersing the organic ultraviolet absorbent composite powder of the present invention in a cosmetic medium and blending it into cosmetics, the organic ultraviolet absorbent is dissolved and close to the state of being uniformly blended in cosmetics. Even when a medium in which the organic ultraviolet absorber is not dissolved is used, an ultraviolet shielding ability equal to or higher than that obtained when the organic ultraviolet absorber is dissolved can be obtained. For this reason, it becomes the cosmetics which have the very outstanding ultraviolet-ray shielding ability by mix | blending the organic type ultraviolet absorber composite powder of this invention.

In the present invention, the surface of a powder serving as a base material such as titanium oxide or zinc oxide is coated with a known organic ultraviolet absorber such as butylmethoxydibenzoylmethane or diethylaminohydroxybenzoyl hexyl benzoate. By adopting a high-performance treatment method, the resulting organic UV absorber composite powder has good dispersibility in cosmetics, and can obtain UV shielding ability equivalent to or better than when the organic UV absorber is dissolved. There is a remarkable effect that can be done.
Further, when the base material is a fine particle powder, it can be dispersed in a cosmetic medium, and can be a composite powder with a wide application range that can be blended into a powder product.

Results of transmittance measurement of Example 1, Comparative Examples 1 and 2 Example 2, transmittance measurement results of Comparative Examples 3 and 4 Results of transmittance measurement of Example 3 and Comparative Example 5

  In the present invention, the organic ultraviolet absorber is dissolved by making the treated powder obtained by coating the powder surface as a base material with a specific organic ultraviolet absorber uniformly dispersed in a cosmetic medium. An organic ultraviolet absorbent composite powder capable of obtaining an ultraviolet shielding ability equivalent to or higher than that of the above-described case can be obtained, and specific embodiments thereof will be described below.

  As the powder used as a base material used in the present invention, a substance widely used as a powder pigment of an inorganic compound such as titanium oxide, zinc oxide, aluminum oxide, magnesium carbonate may be used. Use of titanium oxide or zinc oxide is most effective.

And in order to fully demonstrate the effect of this invention, it is preferable that the powder itself used as a base material has an ultraviolet shielding ability, and the average primary particle diameter of the powder at that time is 10 to 90 nm. Preferably there is.
That is, if the powder as a base material also has an ultraviolet shielding ability, the composite powder obtained by treating the organic ultraviolet absorbent can be expected to have a synergistic effect.
Note that the surface powder may be subjected to some surface treatment with an inorganic compound or a coupling agent so that the organic ultraviolet absorber is more uniformly coated.

  The organic ultraviolet absorber used in the present invention is butylmethoxydibenzoyl which is highly safe, can be easily introduced onto the powder surface as a base material, and is industrially mass-produced and available at low cost. It is effective to use methane (eg Parsol 1789 from DSM) or hexyl diethylaminohydroxybenzoyl benzoate (eg Uvinul A Plus from BASF).

That is, in the present invention, a composite powder having ultraviolet absorbing ability is obtained by coating an organic ultraviolet absorber on the surface of a powder that is a base material of a metal oxide such as titanium oxide or zinc oxide. be able to. These ultraviolet-absorbing powders are composite powders that can be blended into cosmetics in the same manner as ordinary pigments, and effectively prevent the transmission of ultraviolet rays.
Since the UV absorber is uniformly coated on the powder surface, it exhibits resistance to dissolution and outflow of the UV absorber due to water, sweat or sebum, and therefore it is difficult to remove the UV absorber from the skin.
When this cosmetic is applied to the skin, penetration of the UV absorber through the skin or transdermal sebaceous glands does not occur, and the adverse effects on the skin such as phototoxicity and cumulative irritation mentioned above are alleviated, and contact skin The possibility of inflammation such as flame and photocontact dermatitis can be reduced.

200 g of butylmethoxydibenzoylmethane was added as an organic ultraviolet absorber in 3,000 g of toluene and dissolved by stirring and mixing. After dissolution, 1,000 g of fine particle titanium oxide (MT-100Z manufactured by Teika Co., Ltd .: average primary particle diameter of 15 nm) was added and mixed uniformly.
The slurry after mixing was wet crushed by a sand grinder mill to break up the aggregation of fine particle titanium oxide, and then toluene was distilled off under reduced pressure heating.
The obtained dried product was crushed to obtain a composite powder uniformly coated with the butylmethoxydibenzoylmethane.

Measurement of transmittance, SPF and UVA ratio:
The obtained organic ultraviolet absorber composite powder was mixed according to the following formulation, and the mixture was stirred and mixed using a disper (TK Robotics manufactured by Primics) at 3,000 rpm for 10 minutes to obtain a test solution.
Oil phase Cyclopentasiloxane: Shin-Etsu Chemical KF-995 (45 g), mineral oil (5 g), polyether modified silicone: Shin-Etsu Chemical KF-6017P (5 g), composite powder (10 g)
Aqueous phase Water (30 g), Butylene glycol (5 g)

For the test solution, SPF and UVA ratio were measured using an SPF analyzer (measuring instrument / Labsphere UV1000S, base / Vitro-Skin manufactured by IMS, coating amount / 2.0 mg / cm ² ). The transmittance was measured using a U-3300 spectrophotometer manufactured by Hitachi.
The measurement results of SPF and UVA ratio are shown in Table 1, and the measurement results of transmittance are shown in FIG.
[Comparative Example 1]

The blending ratio was adjusted so that the ratio was the same as that of the test liquid evaluated in Example 1, and fine titanium oxide and butylmethoxydibenzoylmethane were not combined and mixed separately. The stirring method is the same as in Example 1.
Oil phase Cyclopentasiloxane: Shin-Etsu Chemical KF-995 (45 g), Mineral oil (5 g), Polyether-modified silicone: Shin-Etsu Chemical KF-6017P (5 g), Fine particle titanium oxide: Teica MT- 100Z (8.33g), butylmethoxydibenzoylmethane (1.67g)
Aqueous phase Water (30 g), Butylene glycol (5 g)
The measurement results of transmittance are shown in FIG. 1, and the measurement results of SPF and UVA ratio are shown in Table 1 together with the case of Example 1.
[Comparative Example 2]

The formulation was the same as that of Comparative Example 1 except that the butylmethoxydibenzoylmethane of Comparative Example 1 was removed and the decrease was supplemented with fine particle titanium oxide (MT-100Z manufactured by Teika).
Oil phase Cyclopentasiloxane: Shin-Etsu Chemical KF-995 (45 g), Mineral oil (5 g), Polyether-modified silicone: Shin-Etsu Chemical KF-6017P (5 g), Fine particle titanium oxide: Teica MT- 100Z (10g),
Aqueous phase Water (30 g), Butylene glycol (5 g)
The measurement results are shown in FIG. 1 and Table 1 together with Example 1 and Comparative Example 1.

[Summary and discussion of results] (Table 1 and Fig. 1)
From the results shown in Table 1, the test liquid containing the composite powder of Example 1 showed higher values for both SPF and UVA ratio than Comparative Examples 1 and 2, and particularly the UV-A (A-wave ultraviolet) shielding ability. It can be seen that the index, UVA ratio, shows a high value.
Further, from the difference in ultraviolet shielding between Example 1 and Comparative Examples 1 and 2 in the transmittance curve shown in FIG. 1, Example 1 exhibits high shielding ability at a wavelength of 350 to 400 nm in the UV-A region. You can see that

The fine particle titanium oxide used in Example 1 is a fine particle having an average primary particle diameter of several tens of nanometers, and the coating state of the organic compound on the surface cannot be directly viewed, but the optical properties after powder dispersion are By studying, it is possible to construct a certain concept about the surface state of the powder.
In Example 1, before compounding, the powder surface of the fine particle titanium oxide is treated with butylmethoxydibenzoylmethane dissolved using an organic solvent.
Butylmethoxydibenzoylmethane has a shielding ability in the UV-A region with the compound alone, but has a low shielding ability in the UV-B region having a shorter wavelength. In addition, since the compound has low solubility in media such as water, silicone oil, and mineral oil, it has the disadvantage that it cannot exhibit ultraviolet shielding ability unless the dispersion method is devised or dissolved in an organic solvent. . This is also clear from the fact that the test solution of Comparative Example 1 simply formulated by physical mixing does not exhibit the shielding ability in the UV-A region.
Since effective results cannot be obtained by physical mixing, the composite powder obtained in Example 1 is such that the surface of the powder serving as the base material is uniformly coated with an organic compound having an ultraviolet absorbing ability. Can think. If it is non-uniform, it is considered that the shielding ability in the UV-A region is not sufficiently developed.
In Comparative Example 2, the organic compound having ultraviolet absorbing ability was not included, and instead it was supplemented with fine particle titanium oxide. As a result, the amount of solid content was increased, and the transparency with visible light was lowered. It is considered that the UV-B shielding ability was improved as compared with Example 1. For this reason, compared with Example 1, SPF shows a slightly low value, and UVA ratio has fallen greatly.

  By the way, the area when the compound is assumed to be a monomolecular film and the specific surface area of the fine particle titanium oxide, which are calculated from the molecular weight of the butylmethoxydibenzoylmethane compounded in the examples, are almost the same value. Therefore, in the composite powder of the present invention, it is presumed that the organic compound having the ultraviolet shielding ability is coated in a state close to a monomolecular film on the surface of the powder as a base material.

The treatment was performed in the same manner as in Example 1 except that the fine particle titanium oxide was changed to the fine particle zinc oxide (MZ-500 manufactured by Taika Co., Ltd .: average primary particle size 30 nm).
[Comparative Example 3]

The treatment was performed in the same manner as in Comparative Example 1 except that the fine particle titanium oxide was changed to the fine particle zinc oxide (MZ-500 manufactured by Teika).
[Comparative Example 4]

  The treatment was performed in the same manner as in Comparative Example 2 except that the fine particle titanium oxide was changed to fine particle zinc oxide (MZY-505S: average primary particle size: 30 nm, manufactured by Taika).

  Table 2 shows the results of measuring the SPF and UVA ratio of the prepared test solution using an SPF analyzer in the same manner as in Example 1. Moreover, the measurement result of the transmittance is shown in FIG.

[Summary and discussion of results] (Table 2 and Figure 2)
From the results of Table 2, it can be seen that the test liquid containing the composite powder of Example 2 shows a higher value for both SPF and UVA ratio than Comparative Examples 3 and 4, and particularly shows a higher value for UVA ratio. Recognize.
Further, in the transmittance curve shown in FIG. 2, due to the difference in ultraviolet shielding between Example 2 and Comparative Examples 3 and 4, also in Example 2, a large shielding ability is expressed in the wavelength of the UV-A region. I understand that.
This indicates that although the state of the effect obtained varies depending on the type of powder serving as the base material, the synergistic effect in ultraviolet shielding, which is the essence of the present invention, is sufficiently expressed.

[Examples 3 and 4], [Comparative Examples 5 and 6]
A W / O cream was prepared with the composition shown in Table 3, and SPF, UVA ratio, and transmittance were measured. The measuring method of each characteristic is the same as that of the Example mentioned above.
In Table 3, the composite powder described in phase B in Example 3 represents the composite powder of butylmethoxydibenzoylmethane and fine particle titanium oxide prepared in Example 1, and in Example 4, 1 shows a composite powder obtained in the same manner as in Example 1 using diethylaminohydroxybenzoyl hexyl benzoate as the organic ultraviolet absorber and fine particle titanium oxide (MT-100Z) as the base powder. . Further, as the organic ultraviolet absorber described in the phase A, butylmethoxydibenzoylmethane was used in Comparative Example 5, and hexyl diethylaminohydroxybenzoyl benzoate was used in Comparative Example 6.
That is, Example 3 and Comparative Example 5 and Example 4 and Comparative Example 6 are combinations in which the same materials are used but the blending methods are different.

How to mix each phase:
1. Phase A is dissolved by heating (80 ° C.) and then cooled to room temperature.
2. Add phase B to phase A and mix evenly with a disper (3000 rpm, 5 minutes).
3. 1. Mix and dissolve phase C. Gradually add to the AB phase mixed in with stirring.
4). Stir in a homomixer until uniform (7000 rpm, 5 minutes) to obtain the product (W / O cream).
The test results are shown in Table 4. Moreover, the transmittance | permeability measurement result of Example 3 and Comparative Example 5 is shown in FIG.

[Summary of results] (Table 4 and Fig. 3)
From the results of Table 4 and FIG. 3, the composite powder of the present invention shows a high value for both SPF and UVA ratio even when blended as a cosmetic ingredient, compared to the case prepared by simple physical mixing. It can be seen that the UVA ratio is particularly high.

[Examples 5 and 6], [Comparative Examples 7 and 8]
An O / W cream was prepared with the formulation shown in Table 5, and SPF and UVA ratio were measured. The measuring method of each characteristic is the same as that of the Example mentioned above.
The composite powder described in Phase B in Table 5 is a composite powder of butylmethoxydibenzoylmethane and fine particle titanium oxide used in Example 3 in Example 5, and in Example 6, 3 shows a composite powder using diethylaminohydroxybenzoyl hexyl benzoate as the organic ultraviolet absorber used in Example 4 and fine particle titanium oxide (MT-100Z) as the base powder. Further, as an organic ultraviolet absorber described in the phase A, butylmethoxydibenzoylmethane was used in Comparative Example 7, and hexyl diethylaminohydroxybenzoyl benzoate was used in Comparative Example 8.
That is, Example 5 and Comparative Example 7, and Example 6 and Comparative Example 8 are combinations in which the same materials are used but the blending methods are different.

How to mix each phase:
1. After the A phase is heated and melted at 80 ° C., the B phase is added to the A phase while maintaining the temperature, and mixed uniformly with a disper (3000 rpm, 5 minutes).
2. Stir Phase C with a homomixer at 80 ° C. and mix until uniform. (5000 rotations, 30 minutes)
3. After phase D is heated and melted at 80 ° C., phase C is added thereto and mixed uniformly.
4. Under stirring at 80 ° C. To the mixed phase of C phase and D phase created in 1. Gradually add the mixed phase of phase A and phase B created in step 1.
5. Stir with a homomixer until uniform (7000 rpm, 5 minutes), then cool to room temperature with stirring to obtain a product (O / W cream).
The test results are shown in Table 6.

[Summary of results] (Tables 4 and 6)
From the results of Tables 4 and 6, the composite powder of the present invention has excellent ultraviolet shielding properties both when blended in a water-in-oil emulsion and as an oil-in-water emulsion as a cosmetic ingredient. I understand that.

From the above examples and comparative examples, by subjecting butylmethoxydibenzoylmethane and diethylaminohydroxybenzoyl hexyl benzoate, which are organic ultraviolet absorbers, to a powder surface serving as a base material such as titanium oxide or zinc oxide, a coating treatment is performed. The obtained organic ultraviolet absorbent composite powder has good dispersibility in cosmetics, and can provide an ultraviolet shielding ability superior to that obtained when an organic ultraviolet absorbent is blended alone.
In addition, by blending the organic ultraviolet absorbent composite powder, a cosmetic having an ultraviolet shielding ability superior to that obtained when the organic ultraviolet absorbent is blended alone can be obtained.

Claims (9)

  A composite powder obtained by coating the surface of a powder serving as a base material with an organic compound having an ultraviolet absorbing ability having low solubility in a medium, using an organic solvent having high solubility.   The surface of the powder used as the base material should be uniformly coated with an organic compound that has low UV-absorbing ability in a medium using a highly soluble organic solvent in a state close to a monomolecular film. Composite powder characterized by   2. The composite powder according to claim 1, wherein an average primary particle diameter of the powder as the base material is 10 to 90 nm.   The composite powder according to claim 1, wherein the powder serving as the base material is an inorganic powder selected from titanium oxide and / or zinc oxide.   2. The composite powder according to claim 1, wherein the organic compound having ultraviolet absorbing ability is butylmethoxydibenzoylmethane and / or hexyl diethylaminohydroxybenzoylbenzoate.   A composite powder having ultraviolet absorbing ability by uniformly surface-coating an organic compound having low solubility in the medium in a state close to a monomolecular film using an organic solvent having high solubility in the compound. How to manufacture.   A cosmetic comprising the composite powder according to any one of claims 1 to 5.   A wavelength of 350 nm to 400 nm obtained by uniformly coating an organic compound having a UV-absorbing ability with low solubility in a medium on a powder surface as a base material using a highly soluble organic solvent. A composite powder characterized by having a transmittance of less than 50%.   The composite powder according to claim 1, wherein in the optical measurement system in which the transmittance at a wavelength of 700 nm is 85% or more, the transmittance at a wavelength of 400 nm is lower by 15% or more than when blended without performing the method of claim 6. .