Aqueous dispersion and cosmetic blended with the same

Abstract

To improve dispersibility of metal oxide particles regardless of the concentration of a surfactant in an aqueous system in an aqueous dispersion.SOLUTION: There is provided an aqueous dispersion which comprises (A) one or two or more selected from metal oxide particles subjected to hydrophobic organic surface treatment, (B) one or two or more selected from acylglutamic acids, (C) one or two or more selected from water-soluble polymers having cationic functional groups, (D) one or two or more selected from nonionic surfactants, (E) one or two or more selected from an anionic water-soluble polymer containing a sulfate group as a functional group and a polyacrylamide and (F) water, wherein the component (D) is selected from those capable of controlling the viscosity to 10000 cps or less when the components (A) to (F) are mixed and stirred.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an aqueous dispersion containing metal oxide particles that have been surface-treated with a hydrophobic organic agent, and to a cosmetic composition containing the aqueous dispersion. [Background technology]

[0002] Various suncare products or base makeup products have been developed to prevent skin damage caused by ultraviolet rays. While organic or inorganic UV filters are mainly used in cosmetics with sunscreen properties, there is a strong demand for inorganic UV filters due to their high safety for human skin, and for example, cosmetics containing metal oxide particles such as titanium oxide, zinc oxide, and cerium oxide have attracted attention.

[0003] Such metal oxide particles are used as oil-based dispersions dispersed in an oily medium, and are used, for example, in the formulation of products such as W / O (Water in Oil) sunscreen creams and lotions. However, since it has been pointed out that W / O-based cosmetics have poor feel and poor cleansing properties, O / W (Oil in Water)-based cosmetics have attracted attention, and aqueous dispersions of metal oxide particles that can be used in O / W-based products have been provided.

[0004] Aqueous dispersions of titanium dioxide, a typical metal oxide used as an inorganic UV filter, are surface-treated with silica to reduce the catalytic activity of titanium dioxide and improve hydrophilicity by utilizing the hydration ability of the silanol groups of silica. While silica surface treatment reduces the leaching of polyvalent metals, it also raises the issue of increased viscosity due to the silanol groups and water-soluble polymers. Furthermore, using large amounts of aqueous dispersions can increase the viscosity of O / W products over time or cause gelation, rendering them unusable. Furthermore, the strong cohesive properties of silanol groups can cause a squeaky feeling between the formulation and the skin, preventing a smooth feel when used.

[0005] Also known is an aqueous dispersion of metal oxide particles in which a fine inorganic powder is subjected to a hydrophobic organic surface treatment and a surfactant is used as a dispersant (see, for example, Patent Document 1). In the aqueous dispersion described in Patent Document 1, by selecting a specific nonionic surfactant, it is possible to uniformly disperse a fine inorganic powder in an aqueous system containing water at a blending amount of 30 mass% or more, and when used in an O / W formulation using an anionic water-soluble polymer, problems such as a decrease in the viscosity of the formulation or gelation do not occur. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] WO2015 / 125622 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the aqueous dispersion described in Patent Document 1, the dispersibility of metal oxide particles depends on the concentration of the surfactant used in the aqueous system; for example, the nonionic surfactant is blended at 20 mass %, and there is a risk that the dispersibility of metal oxide particles in the dispersion will decrease due to dilution or the like when applied to cosmetics.

[0008] The present invention has been made to solve the above-mentioned problems, and aims to provide an aqueous dispersion that exhibits excellent dispersibility of metal oxide particles even when the concentration of dispersant is low, regardless of the concentration of surfactant in the aqueous system, and a cosmetic preparation containing the same. [Means for solving the problem]

[0009] In order to achieve the above object, the present invention provides (A) one or more metal oxide particles selected from the group consisting of hydrophobic organic surface-treated metal oxide particles; (B) one or more acylglutamic acids; (C) one or more water-soluble polymers having a cationic functional group; (D) one or more nonionic surfactants; (E) one or more selected from anionic water-soluble polymers or polyacrylamides containing a sulfate group as a functional group; (F) Water; Including, The component (D) is an aqueous dispersion selected from those that can control the viscosity of the components (A) to (F) when mixed and stirred to 10,000 cps or less.

[0010] In the aqueous dispersion, The (D) component is contained in an amount of 0.05 parts by mass or more per 1 part by mass of the (A) component, The (C) component is contained in an amount of 0.001 part by mass or more per 1 part by mass of the (A) component, The component (E) is preferably contained in an amount of 1.5 parts by mass or less per part by mass of the component (C).

[0011] In the aqueous dispersion, the total amount of the components (B) to (E) is preferably in the range of 0.25 parts by mass or less per 1 part by mass of the component (A).

[0012] The aqueous dispersion is preferably used in cosmetics. [Effects of the Invention]

[0013] According to the present invention, by using components (B) to (E) as dispersants, it is possible to obtain an aqueous dispersion having excellent dispersibility of metal oxide particles, even when the concentration of the dispersant is low, regardless of the concentration of the surfactant in the aqueous system, and a cosmetic preparation containing the aqueous dispersion. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 10 is a graph showing the spectral distribution of transmittance of various dispersions. DETAILED DESCRIPTION OF THE INVENTION

[0015] The aqueous dispersion according to the present embodiment and the cosmetic preparation containing the same will be specifically described below. The aqueous dispersion according to the present embodiment contains the following components (A) to (F). (A) one or more metal oxide particles selected from the group consisting of hydrophobic organic surface-treated metal oxide particles; (B) one or more acylglutamic acids; (C) one or more water-soluble polymers having a cationic functional group; (D) one or more nonionic surfactants; (E) one or more selected from anionic water-soluble polymers or polyacrylamides containing a sulfate group as a functional group; (F)Water

[0016] The metal oxide particles used in component (A) are typically used as inorganic UV filters, and are preferably one or more selected from titanium oxide, zinc oxide, and iron oxide. For example, titanium oxide particles are preferably coated with one or more selected from silica, aluminum hydroxide, alumina, and zirconia as a primary treatment to reduce catalytic activity, and are preferably hydrophobized by a secondary treatment using a silane coupling agent, dimethicone, hydrogen dimethicone, or fatty acid. Examples of metal oxide particles that have undergone such hydrophobic organic surface treatments include triethoxycaprylylsilane-treated titanium oxide particles (STR_100W_OTS, manufactured by Sakai Chemical Industry Co., Ltd.), stearic acid-treated titanium oxide particles (MICRO TITANIUM DIOXIDE MT-100Z, manufactured by Teika Corporation), and triethoxycaprylylsilane-treated zinc oxide particles (Z-COTE HP1, manufactured by BASF).

[0017] The acyl glutamic acid compound (component (B)) is an anionic surfactant that is primarily formulated for hydrophilic emulsification. Examples of such acyl glutamic acid compounds include sodium stearoyl glutamate (Eumulgin SG, manufactured by BASF), TEA-cocoyl glutamate (MIAMI CT-130(S), manufactured by MIWON), and sodium lauroyl glutamate (Plantaton SGL-P, manufactured by BASF).

[0018] The water-soluble polymer having a cationic functional group, component (C), is a component that is blended mainly for the purpose of antistatic properties, and is a water-soluble polymer having a cationic functional group such as diallyldimethylammonium chloride or glycidyltrimethylammonium chloride. Examples of water-soluble polymers having such cationic functional groups include polyquaternium-7 solution (40% pure content) (Salcare Super7 AT1 manufactured by BASF), polyquaternium-7 solution (10% pure content) (MERQUAT 550PR POLYMER manufactured by The Lubrizol Corporation), polyquaternium-6 solution (40% pure content) (ME Polymer H-40W manufactured by Toho Chemical Co., Ltd.), polyquaternium-53 solution (21% pure content) (MERQUAT 2003PR POLYMER manufactured by The Lubrizol Corporation), polyquaternium-39 solution (10% pure content) (MERQUAT 3330PR POLYMER manufactured by The Lubrizol Corporation), guar hydroxypropyltrimonium chloride (JAGUAR EXCEL manufactured by Sansho Co., Ltd.), and polyquaternium-10 (Polyquta LR400KC manufactured by KCI-Japan).

[0019] The nonionic surfactant, component (D), is a component that is added mainly as an emulsifier. Examples of such nonionic surfactants include PEG-20 glyceryl triisostearate (HLB; 10.3) (Pegnol IS-320G, manufactured by Toho Chemical Industry Co., Ltd.), polysorbate 65 (HLB; 10.5) (TWEEN 65-SO-(SG), manufactured by Croda), PEG-20 glyceryl isostearate (HLB; 13) (EMALEX GWIS-120, manufactured by Nippon Emulsion Co., Ltd.), sorbitan isostearate (HLB; 5) (SPAN 120-LQ-(RB), manufactured by Croda), PPG-6-decyltetradeceth-12 (HLB; 8.5) (NIKKOL PEN-4612, manufactured by Nikko Chemicals Co., Ltd.), and polyglyceryl-2 isostearate (HLB; 5.5) (Cosmol 41V, manufactured by The Nisshin Oillio Group, Ltd.).

[0020] The anionic water-soluble polymer or polyacrylamide containing sulfate groups as functional groups, which is the component (E), is primarily used as a thickener. Examples of such anionic water-soluble polymers containing sulfate groups as functional groups include (hydroxyethyl acrylate / sodium acryloyldimethyltaurate) copolymer (SEPINOV EMT 10, manufactured by SEPPIC), (ammonium acryloyldimethyltaurate / VP) copolymer (Aristoflex AVC, manufactured by Clariant Japan), sodium polyacryloyldimethyltaurate (Aristoflex SILK, manufactured by Clariant Japan), and carrageenan (GENUVISCO type PJ-JPE, manufactured by Sansho Co., Ltd.). Examples of polyacrylamides include polyacrylamide (purity: 40%) (SEPIGEL 305, manufactured by SEPPIC).

[0021] Examples of the water of the above component (F) include tap water, ion-exchanged water, distilled water, purified water, and natural water, and sterilized water is preferred.

[0022] In addition to the above components (A) to (F), preservatives such as 1,3-butylene glycol, phenoxyethanol, and phenoxyisopropanol may also be added.

[0023] The aqueous dispersion of this embodiment contains the above components (A) to (F) blended together to meet the following conditions: Component (D) is selected from those that allow the viscosity at 25°C to be controlled to 10,000 cps or less when components (A) to (F) are mixed and stirred. The component (D) is contained in an amount of 0.05 part by mass or more per part by mass of the component (A). The component (C) is contained in an amount of 0.001 part by mass or more per part by mass of the component (A). The component (E) is blended in an amount of 1.5 parts by mass or less per 1 part by mass of the component (C).

[0024] The aqueous dispersions produced by blending the above components will be described in more detail below with reference to examples and comparative examples. It should be noted that the present invention is not necessarily limited to these examples. Unless otherwise specified, the numerical values ​​for the blending amounts of each component listed in the following tables refer to "% by mass," with the total mass being 100%.

[0025] <Examples 1 to 3, Comparative Examples 1 to 3> In Examples 1 to 3, the types of components (B) to (E) were the same, but the type of component (A) was different. As the hydrophobic organic surface-treated metal oxide particles of component (A), Example 1 used triethoxycaprylylsilane-treated titanium dioxide microparticles, Example 2 used stearic acid-treated titanium dioxide microparticles, and Example 3 used triethoxycaprylylsilane-treated zinc oxide microparticles. As the acyl glutamic acid of component (B), sodium stearoyl glutamate was used. As the water-soluble polymer having a cationic functional group of component (C), polyquaternium-7 was used. As the nonionic surfactant of component (D), PEG-20 glyceryl triisostearate was used. As the anionic water-soluble polymer having a sulfate group as a functional group (E), (hydroxyethyl acrylate / sodium acryloyldimethyltaurate) copolymer was used. Further, 1,3-butylene glycol was added, and as the remainder, water of component (F) was added. Components (B) to (E) are dispersants of this embodiment, and the blending ratio (concentration) of the dispersant is 5.65 mass % in Examples 1 to 3. The detailed blending amounts of each of the above components are shown in Table 1 below.

[0026] After the components (A) to (F) were heated, mixed, and dispersed, the metal oxide particles of component (A) were gradually added to the mixture using a Lavorution (Primix Corporation; Despa Mixer Attachment) and pre-dispersed to prepare a pre-dispersion for each sample. The pre-dispersion viscosity (cps) of each sample pre-dispersion was measured using a Brookfield viscometer. The Lavorution was replaced with a Homomixer Attachment and the pre-dispersion for each sample was further dispersed to prepare the aqueous dispersions of Examples 1 to 3. Each of the resulting aqueous dispersions was diluted with water (30,000-fold dilution) to a metal oxide particle concentration of 0.001% by mass, and the dispersibility of each aqueous dispersion was evaluated by measuring the transmittance at wavelengths of 200 to 600 nm using a spectrophotometer (Shimadzu Corporation UV-1280).

[0027] In Comparative Examples 1 to 3, the above components (B) to (E) were not used, and instead, the silicone surfactant PEG-11 methyl ether dimethicone (HLB: 14.5) (KF-6011P, manufactured by Shin-Etsu Chemical Co., Ltd.) was used as the dispersant. The component (A) in Comparative Examples 1 to 3 was the same as that in Examples 1 to 3, respectively. 1,3-butylene glycol and water were added, mixed, and dispersed, and then metal oxide particles were dispersed using a Lavorution (manufactured by Primix Corporation; homomixer attachment) to prepare a dispersion. As in Examples 1 to 3, each of the resulting dispersions was diluted with water to a metal oxide particle concentration of 0.001% by mass, and the transmittance at wavelengths of 200 to 600 nm was measured using a spectrophotometer (Shimadzu Corporation UV-1280).

[0028] [Table 1]

[0029] FIG. 1 shows the spectral distribution (transmission spectrum) of transmittance in the wavelength range of 200 to 600 nm for the aqueous dispersions of Examples 1 to 3 and the dispersions of Comparative Examples 1 to 3. In Examples 1 and 2 and Comparative Examples 1 and 2, which use titanium oxide as the metal oxide particles, the minimum value of transmittance (maximum value of cut rate) is observed in the wavelength range of 300 to 350 nm. Furthermore, in the entire wavelength range of 200 to 600 nm, Example 1 has a lower transmittance than Comparative Example 1, and Example 2 also has a lower transmittance than Comparative Example 2. This decrease in transmittance, i.e., an increase in cut rate, is thought to be due to the improved dispersibility of the metal oxide particles, which act as UV filters.

[0030] Furthermore, Example 3 and Comparative Example 3, which used zinc oxide as the metal oxide particles, showed a decrease in transmittance (increase in cut rate) in the wavelength range of 350 to 400 nm. Furthermore, similar to the case of titanium oxide described above, Example 3 showed a higher cut rate than Comparative Example 3 in the entire wavelength range of 200 to 600 nm, which is considered to indicate improved dispersibility. Thus, it was demonstrated that the dispersibility of metal oxide particles was improved by incorporating components (B) to (E) as dispersants.

[0031] <Examples 4 to 9, Comparative Example 4> In Examples 4 to 9 and Comparative Example 4, tests were conducted by varying the amounts of the components (B) to (E). The metal oxide used in component (A) was zinc oxide, and triethoxycaprylylsilane-treated particles were used, which do not violate EU microplastics regulations in the hydrophobic treatment. Polyquaternium-10 was used for component (C). The types of components (B), (D), and (E) were the same as in Examples 1 to 3 above. The blending ratios (concentrations) of the dispersants in Examples 4 to 9 were 2.12 to 6.3% by mass. The dispersant concentration in Comparative Example 4 was 1.62% by mass. The blending amounts were determined as shown in Table 2 below, and aqueous dispersions were prepared using the same procedures as in Examples 1 to 3 above. Transmittance measurements were also performed using the same procedures as in Examples 1 to 3 above.

[0032] [Table 2]

[0033] In Table 2 above, the evaluation of dispersibility based on transmittance was as follows. The same applies to Tables 3 to 8 below. ◯: The transmittance is lower (cut rate is higher) than the transmission spectrum of Comparative Example 3 (see FIG. 1), and the dispersibility is better than that of Comparative Example 3. △: The transmittance is equivalent to that of the transmission spectrum of Comparative Example 3 (the cut rate is equivalent), and the dispersibility is equivalent to that of Comparative Example 3. ×: The transmittance is higher (cut rate is lower) than the transmission spectrum of Comparative Example 3, and the dispersibility is inferior to that of Comparative Example 3. ND: The concentrated viscosity of the pre-dispersion is 10,000 cps or more, and is not subject to measurement.

[0034] As shown in Table 2, the pre-dispersion concentration tends to increase as the contents of components (B), (C), and (D) decrease, but in Examples 4 to 9, the pre-dispersion viscosity was 10,000 cps or less at all blending amounts, and the dispersibility was also excellent. On the other hand, in Comparative Example 4, in which the amount of component (D) was 0.0375 part by mass per part by mass of component (A), the pre-dispersion viscosity was 45,000 cps, and it was impossible to apply homomixer dispersion to the prepared dispersion, so dispersibility evaluation by transmittance measurement was omitted.

[0035] Furthermore, in Examples 8 and 9, in which the amount of the (D) component was 0.05 parts by mass per 1 part by mass of the (A) component, the pre-dispersion viscosity was 10,000 cps or less and the dispersibility evaluation was also good, indicating that it is preferable to include the (D) component in an amount of 0.05 parts by mass or more per 1 part by mass of the (A) component.

[0036] Furthermore, in Example 9, in which the amount of the (C) component was 0.00125 parts by mass per 1 part by mass of the (A) component, the pre-dispersion viscosity was 10,000 cps or less and the dispersibility evaluation was also good, indicating that the (C) component only needs to be contained in an amount of 0.001 parts by mass or more per 1 part by mass of the (A) component.

[0037] Furthermore, the total of components (B) to (E), i.e., the blending ratio (concentration) of the dispersant in Examples 4 to 9, was 2.12 to 6.3% by mass, all of which were 10% by mass or less. These results demonstrate that the upper limit of the total of components (B) to (E) should be 0.25 parts by mass or less per part by mass of component (A). Furthermore, the lower limit of the total of components (B) to (E) should be 0.05 parts by mass or more per part by mass of component (A). Thus, according to this embodiment, it is possible to obtain an aqueous dispersion with excellent dispersibility of metal oxide particles, even when the dispersant concentration is low, and a cosmetic preparation incorporating the same.

[0038] <Examples 10 to 14, Comparative Example 5> In Examples 10 to 14 and Comparative Example 5, tests were conducted in which the type and amount of water-soluble polymer having a cationic functional group (component (C))) was varied. Specifically, in Example 10, a polyquaternium-7 solution (10% pure content) was used, in Example 11, a polyquaternium-6 solution (40% pure content) was used, in Example 12, a polyquaternium-53 solution (21% pure content) was used, in Example 13, a polyquaternium-39 solution (10% pure content) was used, and in Example 14 and Comparative Example 5, guar hydroxypropyltrimonium chloride was used. In Examples 10 to 13, the amount of each solution was adjusted so that the pure content was 0.5% by mass. Triethoxycaprylylsilane-treated zinc oxide fine particles were used as component (A). The dispersant concentration was 6.2% by mass in Examples 10 to 13 and 5.9% by mass in Example 14. Then, the blending amounts were determined as shown in Table 3 below, and each aqueous dispersion was prepared in the same manner as in Examples 1 to 3 above, and the dispersibility was evaluated in the same manner as in Examples 4 to 9 above.

[0039] [Table 3]

[0040] As shown in Table 3, for all five (C) components shown in Examples 10 to 14, the pre-dispersion concentrated viscosity was 10,000 cps or less, and the dispersibility was also excellent. On the other hand, in Comparative Example 5, the pre-dispersion viscosity exceeded 100,000 cps at a blending amount of 0.5% by mass of guar hydroxypropyltrimonium chloride, which made it impossible to perform homomixer dispersion on the prepared dispersion. Therefore, dispersibility evaluation by transmittance measurement was not performed. However, as shown in Example 14, when the blending amount of guar hydroxypropyltrimonium chloride was increased to 0.2% by mass, the pre-dispersion concentrated viscosity was 10,000 cps or less, and the dispersibility evaluation was also improved. In other words, when a component used as a hydrophilic thickener, such as guar hydroxypropyltrimonium chloride, is used as the (C) component, it is preferable that the blending amount be 0.2% by mass or less.

[0041] <Comparative Examples 6 to 9> In Comparative Examples 6 to 9, tests were conducted in which any of the components (B) to (E) was not blended. The blending amounts of the components other than the component that was not blended were the same as in Example 10 above. Note that a polyquaternium-7 solution (purity: 10%) was used as the component (C), and the types of components (B), (D), and (E) were the same as in Examples 1 to 3 above. Triethoxycaprylylsilane-treated zinc oxide fine particles were used as the component (A). The blending amounts were determined as shown in Table 4 below, and each aqueous dispersion was prepared using the same procedure as in Examples 1 to 3 above. The transmittance was also measured using the same procedure as in Examples 1 to 3 above, and dispersibility was evaluated using the same procedure as in Examples 4 to 9 above.

[0042] [Table 4]

[0043] As shown in Table 4, in Comparative Examples 6, 7, and 9, the pre-dispersion viscosity was 10,000 cps or more, and did not satisfy the evaluation criteria. In Comparative Example 8, the pre-dispersion viscosity was 10,000 cps or less, but the dispersibility was evaluated as low. These results demonstrate that it is necessary to blend all of the components (B) to (E), as in Example 10.

[0044] <Examples 15 to 17, Comparative Example 10> In Examples 15 to 17 and Comparative Example 10, tests were conducted in which the amount of component (E), an anionic water-soluble polymer or polyacrylamide containing sulfate groups as functional groups, was varied. For component (C), a polyquaternium-7 solution (purity: 10%) was used, and the types of components (B), (D), and (E) were the same as in Examples 1 to 3. For component (A), triethoxycaprylylsilane-treated zinc oxide fine particles were used. The blending ratio (concentration) of the dispersant in Examples 15 to 17 was 6.02 to 7% by mass. The blending amounts were determined as shown in Table 5 below, and aqueous dispersions were prepared using the same procedures as in Examples 1 to 3. Transmittance measurements were also performed using the same procedures as in Examples 1 to 3, and dispersibility was evaluated using the same procedures as in Examples 4 to 9.

[0045] [Table 5]

[0046] As shown in Table 5, in Examples 15 to 17, the pre-dispersion concentrated viscosity was 10,000 cps or less at any blending amount of component (E), and the dispersibility was also excellent. Note that the component (C) used was a polyquaternium-7 solution (purity: 10%), so the component (C) content in Examples 15 to 17 and Comparative Example 10 was 0.5 mass%. That is, Example 17, in which the component (E) was 1.5 mass parts (0.75 mass%) per 1 part (0.5 mass%) of component (C), had a good dispersibility evaluation. On the other hand, Comparative Example 10, in which the component (E) was 5 mass parts (1 mass%) per 1 part (0.5 mass%) of component (C), had a pre-dispersion viscosity of 10,000 cps or more, and did not satisfy the evaluation criteria. These results demonstrate that the component (E) is preferably contained in an amount of 1.5 mass parts or less per 1 part (C) of component (C).

[0047] <Examples 18 to 23 and Comparative Examples 11 to 14> In Examples 18 to 23, tests were conducted in which the type of nonionic surfactant used as component (D) was varied while maintaining the formulation conditions of Example 15. As component (D), PEG-20 glyceryl triisostearate (HLB: 10.3) was used in Example 18, polysorbate 65 (HLB: 10.5) in Example 19, PEG-20 glyceryl isostearate (HLB: 13) in Example 20, sorbitan isostearate (HLB: 5) in Example 21, PPG-6 decyltetradeceth-12 (HLB: 8.5) in Example 22, and polyglyceryl-2 isostearate (HLB: 5.5) in Example 23 were used. Furthermore, PEG-10 hydrogenated castor oil (HLB; 6.5) was used in Comparative Example 11, PEG-20 hydrogenated castor oil (HLB; 10.5) in Comparative Example 12, PEG-40 stearate (HLB; 18) in Comparative Example 13, and PEG-60 glyceryl isostearate (HLB; 0.16) in Comparative Example 14. The blending ratio (concentration) of the dispersant in Examples 18 to 23 was 4.2 mass%. The blending amounts were determined as shown in Table 6 below, and each aqueous dispersion was prepared using the same procedures as in Examples 1 to 3 above. Transmittance measurements were also performed using the same procedures as in Examples 1 to 3 above, and dispersibility was evaluated using the same procedures as in Examples 4 to 9 above.

[0048] [Table 6]

[0049] As shown in Table 6, in Examples 18 to 23, when the component (D) was of the indicated type, the pre-dispersion concentrated viscosity was 10,000 cps or less, and the dispersibility was also excellent. On the other hand, in Comparative Examples 11 to 14, the pre-dispersion viscosity was 10,000 cps or more, and the evaluation conditions were not met. These results indicate that among nonionic surfactants, some are useful and some are not, and that it is necessary to find a useful nonionic surfactant through repeated trial and error.

[0050] HLB (hydrophile-lipophile balance) is an index ranging from 0 to 20, with higher lipophilicity indicating a lower value and higher hydrophilicity indicating a higher value. In the tests shown in Table 6, the HLB was varied over a wide range, but no correlation was observed between HLB and dispersibility evaluation.

[0051] <Examples 24 to 28> In Examples 24 to 28, tests were conducted by varying the type of anionic water-soluble polymer or polyacrylamide containing sulfate groups as functional groups, which is component (E). As component (E), Example 24 used a (hydroxyethyl acrylate / sodium acryloyldimethyltaurate) copolymer, Example 25 used an (ammonium acryloyldimethyltaurate / VP) copolymer, Example 26 used sodium polyacryloyldimethyltaurate, Example 27 used polyacrylamide (purity: 40%), and Example 28 used carrageenan. Of these, the component (E) in Examples 24 to 26 and 28 was an anionic water-soluble polymer containing sulfate groups, and the component (E) in Example 27 was polyacrylamide. Note that a polyquaternium-7 solution (purity: 10%) was used as component (C), and the types of components (B) and (D) were the same as in Examples 1 to 3. As component (A), triethoxycaprylylsilane-treated zinc oxide fine particles were used. The blending ratio (concentration) of the dispersant in Examples 24 to 28 was 4.5% by mass. The blending amounts were determined as shown in Table 7 below, and each aqueous dispersion was prepared using the same procedures as in Examples 1 to 3. The transmittance was also measured using the same procedures as in Examples 1 to 3, and the dispersibility was evaluated using the same procedures as in Examples 4 to 9.

[0052] [Table 7]

[0053] As shown in Table 7, in Examples 24 to 28, the concentrated viscosity of the pre-dispersion was 10,000 cps or less for all of the components (E), and the dispersibility was also excellent.

[0054] <Examples 29 to 31> In Examples 29 to 31, tests were conducted in which the type of acyl glutamic acid used as component (B) was changed. In Example 29, sodium myristoyl glutamate was used as component (B). In Example 29, TEA-cocoyl glutamate was used, and in Example 29, sodium lauroyl glutamate was used. Note that polyquaternium 10 was used as component (C), and the types of components (D) and (E) were the same as in Examples 1 to 3 above. Triethoxycaprylylsilane-treated zinc oxide fine particles were used as component (A). The blending ratio (concentration) of the dispersant in Examples 29 to 31 was 3.5% by mass. The blending amounts were determined as shown in Table 8 below, and each aqueous dispersion was prepared using the same procedure as in Examples 1 to 3 above. Transmittance was also measured using the same procedure as in Examples 1 to 3 above, and dispersibility was evaluated using the same procedure as in Examples 4 to 9 above.

[0055] [Table 8]

[0056] In all of the above-mentioned sodium stearoyl glutamate used as component (B) in the above-mentioned Examples, sodium myristoyl glutamate (Example 29) and sodium lauroyl glutamate (Example 31), in which only the acyl group was changed, and TEA-cocoyl glutamate (Example 30), in which the acyl group and counter base were changed, the concentrated viscosity of the pre-dispersion was 10,000 cps or less, and the dispersibility was also excellent.

[0057] <Cosmetic use example 1> Cosmetic Use Example 1 is a cosmetic that uses the aqueous dispersions of Examples 1 and 7 from the above Examples 1 to 31. Specifically, (1) 30% by mass of the aqueous dispersion of Example 1, (2) 50.0% by mass of the aqueous dispersion of Example 7, (3) an appropriate amount of preservative, (4) water: residue, (5) 5.0% by mass of trimethylsiloxysilicate (purity; 50%) (KF-7312J manufactured by Shin-Etsu Chemical Co., Ltd.), and (6) 10.0% by mass of dimethicone (KF-96A-100CS manufactured by Shin-Etsu Chemical Co., Ltd.) were stirred at room temperature using a Lavorution (Despa Mixer Attachment manufactured by Primix Corporation) to obtain a SHAKE WELL type watery sunscreen (free of chemical UV absorbers).

[0058] <Cosmetic use example 2> Cosmetic Use Example 2 is a cosmetic that uses the aqueous dispersions of Examples 1 and 26 from among Examples 1 to 31 above. Specifically, (1) aqueous dispersion of Example 1: 30.0% by mass, (2) aqueous dispersion of Example 26: 50.0% by mass, (3) triethoxycaprylylsilane-treated pigment-grade titanium oxide (OTS-2 TiO2 CR-50 manufactured by Daito Chemical Industry Co., Ltd.): 3% by mass, (4) triethoxycaprylylsilane-treated talc (OTS-2 TALC JA-46R manufactured by Daito Chemical Industry Co., Ltd.): 1.5% by mass, (5) triethoxycaprylylsilane-treated iron oxide (OTS-2 RED R-516L manufactured by Daito Chemical Industry Co., Ltd.): 0.05% by mass, (6) triethoxycaprylylsilane-treated iron oxide (OTS-2 YELLOW LLXLO manufactured by Daito Chemical Industry Co., Ltd.): 0.65% by mass, (7) triethoxycaprylylsilane-treated iron oxide (OTS-2 BLACK (BL-100P): 0.05% by mass, (8) preservative: appropriate amount, (9) water: balance, (10) trimethylsiloxysilicate (purity: 50%, Shin-Etsu Chemical Co., Ltd. KF-7312J): 3.0% by mass, and (11) dimethicone (Shin-Etsu Chemical Co., Ltd. KF-96A-100CS): 10.0% by mass were stirred at room temperature using a Lavorution (Primix Corporation; Despa Mixer Attachment) to obtain an O / W type liquid foundation (free of chemical UV absorbers).

[0059] The aqueous dispersion of this embodiment and the cosmetic preparation using the same may contain any other ingredients in addition to the above-mentioned components, as long as the effects of the invention are not impaired. Examples of such optional ingredients include moisturizers, herbal medicines, pH adjusters, chelating agents, preservatives, antioxidants, cooling agents, vitamins, proteins, polymers, fragrances, antibacterial agents, thickeners, and pigments. Furthermore, while the present invention is intended to be applied to sun care products that specifically suppress skin damage caused by ultraviolet rays, it goes without saying that the present invention can be adapted for use in various topical skin preparations and can be expanded into any composition containing metal oxide particles that act as a UV-blocking filter and various surfactants.

Claims

1. (A) one or more metal oxide particles selected from the group consisting of metal oxide particles having a hydrophobic organic surface treatment; (B) one or more acylglutamic acids; (C) one or more water-soluble polymers having a cationic functional group; (D) one or more nonionic surfactants, (E) one or more selected from anionic water-soluble polymers or polyacrylamides containing a sulfate group as a functional group; (F) Water; Including, The component (D) is an aqueous dispersion selected from those that can control the viscosity of the components (A) to (F) when mixed and stirred to 10,000 cps or less.

2. The component (D) is contained in an amount of 0.05 parts by mass or more per 1 part by mass of the component (A), The component (C) is contained in an amount of 0.001 parts by mass or more per 1 part by mass of the component (A), 2. The aqueous dispersion according to claim 1, wherein the component (E) is contained in an amount of 1.5 parts by mass or less per 1 part by mass of the component (C).

3. 2. The aqueous dispersion according to claim 1, wherein the total amount of the components (B) to (E) is contained in a range of 0.25 parts by mass or less per 1 part by mass of the component (A).

4. A cosmetic preparation containing the aqueous dispersion according to any one of claims 1 to 3.

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