Powder dispersion composition and cosmetic

Abstract

The powder dispersion composition contains (a) a hydrophobized metal oxide powder, (b) at least one of a polyether-modified silicone and a polyglycol ether having an HLB of 5-17, (c) a hydroxycarboxylate having 2-10 carbon atoms, and (d) a polymer containing a constituent unit derived from (meth) acrylic acid and / or a constituent unit derived from an alkyl (meth) acrylate, or a salt thereof. The ratio of the content of the component (d) to the content of the component (a) is 1.2 * 10 <-4 > to 2.3 * 10 <-3 > inclusive, and the ratio of the content of the component (c) to the content of the component (a) is 1.2 * 10 <-3 > to 2.3 * 10 <-2 > inclusive.

Description

Technical Field

[0001] The present invention relates to powder dispersion compositions and cosmetics. Background Art

[0002] It is known in the cosmetics field that in the composition of the oil-water two-phase, as an ultraviolet scattering agent, etc., a product containing a metal oxide powder whose surface is hydrophobized is used. Such a metal oxide powder that is hydrophobized is usually present in the oil phase. However, in recent years, it is necessary to increase the content of the metal oxide powder in the composition. Therefore, in order to be able to have more metal oxide powder that is hydrophobized in the water phase, it is necessary to improve the dispersion state of the metal oxide powder that is hydrophobized in the water phase. For example, in order to better disperse the metal oxide powder that is hydrophobized in the water phase, it has been studied that specific silicones, etc. are used as dispersants, etc. (for example, patent documentation 1, 2).

[0003] [Prior art literature]

[0004] [Patent Literature]

[0005] [Patent Document 1] Patent No. 3288765

[0006] [Patent Document 2] Patent No. 6627833 Summary of the invention

[0007] [Problems to be solved by the invention]

[0008] However, there is still room for research on suppressing the aggregation of the hydrophobized metal oxide powder and obtaining a better dispersed state.

[0009] In view of the above circumstances, an object of one embodiment of the present invention is to provide a powder dispersion composition that exhibits good powder dispersion properties.

[0010]

Methods to solve the problem

[0011] In order to solve the above-mentioned problems, one embodiment of the present invention is a powder dispersion composition comprising: (a) a hydrophobized metal oxide powder, (b) a polyether-modified silicone having an HLB of 5 to 17, (c) a hydroxycarboxylate having 2 to 10 carbon atoms, and (d) a polymer containing a constituent unit derived from (meth)acrylic acid and / or a constituent unit derived from an alkyl (meth)acrylate, or a salt thereof, wherein the ratio of the content of the component (d) to the content of the component (a) is 1.2×10 -4 Above 2.3×10 -3 Hereinafter, the ratio of the content of the component (c) to the content of the component (a) is 1.2×10 -3 Above 2.3×10 -2the following.

[0012] [Effects of the Invention]

[0013] According to one embodiment of the present invention, there is provided a powder dispersion composition showing a good powder dispersion state. DETAILED DESCRIPTION

[0014] Embodiments of the present invention will be described in detail below, but the present invention is not limited to the following embodiments.

[0015] <Powder dispersion composition>

[0016] The powder dispersion composition of the present embodiment is a composition for dispersing powder. The powder dispersion composition includes a substance that maintains a powder dispersion state during the usual storage period, and further includes a substance that the powder is deposited during the usual storage period in the art, but can be redispersed by a common method in the art, such as by stirring the composition and shaking the container. In addition, the powder dispersion composition of the present embodiment can be an aqueous dispersion composition (aqueous dispersion) in which the powder is dispersed in an aqueous medium. The powder dispersion composition can be used directly or in combination with other ingredients, for example, it can be mixed with an oil component to prepare a composition containing both an oil phase and an aqueous phase. The product obtained by adding other ingredients to the powder dispersion composition of the present embodiment is suitable for skin coating products such as cosmetics.

[0017] In the powder dispersion composition of the composition of the present embodiment, a good dispersion state of the metal oxide powder treated by hydrophobization can be obtained. Here, in this specification, a good dispersion state refers to that at least after just preparing, the agglomeration of powder particles is suppressed, and the powder particles are dispersed in a state (dispersibility or initial dispersibility) with a smaller agglomeration particle size. Further, a good dispersion state also includes, keeping the composition, preventing the temporarily deposited powder from agglomerating (resistance to agglomeration, i.e., powder can be redispersed under normal use conditions), and when the temporarily deposited powder is redispersed, it can be uniformly dispersed (dispersion stability) with a smaller agglomeration particle size.

[0018] The viscosity of the powder dispersion composition of the present embodiment can be 5 mPa·s or more and 10000 mPa·s or less. With the viscosity in this range, the powder dispersion composition exhibits good initial dispersibility. In addition, a powder dispersion composition with a low viscosity that exhibits good initial dispersibility may have poor caking resistance and dispersion stability, but according to the composition of the present embodiment, not only the initial dispersibility is good, but also the caking resistance and dispersion stability are good.

[0019] <(a) Hydrophobized Metal Oxide Powder>

[0020] The component (a) contained in the powder dispersion composition is a metal oxide powder treated by hydrophobization. The metal oxide powder treated by hydrophobization preferably has a powder with ultraviolet scattering function, i.e., a preferred ultraviolet scattering agent. When it is an ultraviolet scattering agent, the average particle size of its primary particles is more than 10nm and less than 100nm. In addition, at this time, as a specific example of the metal oxide treated by hydrophobization, titanium oxide, zinc oxide, cerium oxide, talc, silicon dioxide, mica, sericite, kaolin, titanium mica, black iron oxide, yellow iron oxide, ferric oxide, ultramarine, cyan blue, chromium oxide, chromium hydroxide, etc. can be cited. Wherein, due to the high ultraviolet scattering function, titanium oxide and zinc oxide are preferred. In addition, composite powders can also be used, which are particles composed of materials other than titanium oxide covered with titanium oxide.

[0021] The above-mentioned hydrophobized metal oxide powders may be used alone or in combination of two or more.

[0022] The hydrophobic treatment implemented on the metal oxide powder can be a process of introducing a hydrophobic group or forming a covering of a hydrophobic substance on the particle surface of the metal oxide. The hydrophobic treatment can specifically be a wet method, a gas phase method, a mechanochemical method, etc. using a solvent. In addition, as the treating agent in the hydrophobic treatment, silicone, dextrin fatty acid ester, higher fatty acid, higher alcohol, fatty acid ester, metal soap, alkyl phosphate ester ether, fluorine compound, or squalane, the hydrocarbon of paraffin, etc., can be used, such as methyl hydrogen polysiloxane, dimethyl polysiloxane, triethoxyoctylsilane, etc.

[0023] The content of the hydrophobized metal oxide powder of component (a) is preferably 5% by mass or more and 40% by mass or less, and more preferably 10% by mass or more and 30% by mass or less, relative to the total amount of the powder dispersion composition. By allowing the content of the hydrophobized metal oxide powder to be 5% by mass or more, in the powder dispersion composition or the cosmetics prepared with the powder dispersion composition, the function of the metal oxide powder, such as the ultraviolet scattering function, can be improved. By allowing the above content to be 40% by mass or less, the dispersion state of the metal oxide powder in the powder dispersion composition or the powder dispersion composition can be good. In addition, the content of the ultraviolet scattering agent is preferably 5% by mass or more and 40% by mass or less, and more preferably 10% by mass or more and 30% by mass or less, relative to the total amount of the powder dispersion composition.

[0024] <(b) Dispersants with an HLB value of 5 or more and 17 or less>

[0025] Component (b) has the function of a dispersant (or surfactant) and can improve the dispersion state of the hydrophobized powder. Among the above, polyether-modified silicones having an HLB of 5 to 17 are preferred because they can help improve the function as a dispersant, especially improve the dispersion stability. Polyether-modified silicones are silicones with polyether side chains introduced into the silicone main chain.

[0026] The polyether-modified silicone can improve the dispersion state of the hydrophobized powder in the composition by having an HLB of 5 to 17. Furthermore, the HLB is preferably 5 to 16, more preferably 6 to 10, thereby improving the initial dispersibility, anti-caking property and dispersion stability of the hydrophobized powder in the composition.

[0027] When component (b) is a polyether-modified silicone, a polydimethylsiloxane having a PEG chain and / or a PPG chain is preferred, and a polydimethylsiloxane having a PEG chain is more preferred. In this case, the average number of moles of olefin oxide added may be 8 or more and 40 or less. In addition, it may be an alkyl ether of a polydimethylsiloxane having a PEG chain and / or a PPG chain at the end. For example, as a polyether-modified silicone, PEG-12 polydimethylsiloxane is preferred. In addition, the silicone chain of a polyether-modified silicone having an HLB of 5 or more and 17 or less may be a straight chain or a branched chain, but a straight chain is preferred. In addition, it may be a polyether-modified alkyl-modified silicone also having an alkyl side chain, but the alkyl group is preferably unmodified.

[0028] Moreover, as a preferable specific example of the polyether-modified silicone having an HLB of 5 or more and 17 or less, "DOWSIL ES-5373 (HLB=8)" manufactured by The Dow Chemical Company and the like are mentioned.

[0029] The above-mentioned polyether-modified silicones may be used alone or in combination of two or more.

[0030] The content of component (b) is preferably 0.1% by mass to 15% by mass, more preferably 1% by mass to 10% by mass, relative to the total amount of the powder dispersion composition. By making the content of component (b) within the above range, the dispersion state of the hydrophobized powder in the composition can be improved.

[0031] <(c) Hydroxycarboxylate>

[0032] Component (c) hydroxycarboxylate prevents gelation of the solute and improves the dispersion state, especially the dispersion stability, and can be regarded as a dispersion stabilizer. The number of carboxyl groups contained in the hydroxycarboxylate used in the present embodiment is 1 or more, preferably 1 to 4. In addition, it can be a salt of an aliphatic carboxylic acid or a derivative thereof, or a salt of an aromatic carboxylic acid or a derivative thereof, but preferably a salt of an aliphatic hydroxycarboxylic acid. As a specific example of a suitable hydroxycarboxylate, citrate can be cited.

[0033] The above-mentioned hydroxycarboxylates may be used alone or in combination of two or more.

[0034] The content of the hydroxycarboxylate of component (c) is preferably 0.03% by mass or more and 0.4% by mass or less, and more preferably 0.05% by mass or more and 0.3% by mass or less, relative to the total amount of the powder dispersion composition. By making the content of component (c) within the above range, the dispersion state of the hydrophobized powder can be improved. In particular, by making the content of component (c) at least 0.03% by mass, the dispersion stability can be particularly improved, and by making it at most 0.4% by mass, the initial dispersibility, anti-caking property and dispersion stability can be improved.

[0035] Furthermore, the ratio of the content of the hydroxycarboxylate of the component (c) to the content of the hydrophobized metal oxide powder of the component (a) ([content of the component (c)] / [content of the component (a)]) is preferably 1.2×10 -3 Above 2.3×10 -2 Below, more preferably 1.5×10 -3 Above 2×10 -2 By making the ratio within the above range, the dispersion state of the hydrophobized powder can be improved. In particular, by making the ratio within 1.2×10 -3 Above, the dispersion stability can be improved particularly by -2 The following can improve initial dispersibility, anti-caking properties and dispersion stability.

[0036] <(d) Acrylic polymer>

[0037] The component (d) acrylic polymer can be considered to be added as an anti-caking agent. The component (d) is a polymer comprising constituent units from (meth) acrylic acid and / or constituent units from (meth) alkyl acrylate. The polymer can be a homopolymer, a copolymer, or a cross-linked polymer. Further, the component (d) acrylic polymer can be a salt neutralized with an alkaline substance. In the present embodiment, by mixing the component (d) in a specified amount, the dispersion state of the hydrophobized powder can be improved.

[0038] More specifically, the component (d) polymer may be a polymer containing unsubstituted or substituted constituent units derived from (meth)acrylic acid and / or unsubstituted or substituted constituent units derived from alkyl (meth)acrylates, a polymer containing unsubstituted constituent units derived from (meth)acrylic acid and / or unsubstituted constituent units derived from alkyl (meth)acrylates, and preferably a polymer composed of constituent units having no functional groups such as amide groups and sulfonic acid groups.

[0039] Specific examples of component (d) include carboxyvinyl polymer (carbomer), polyacrylic acid, sodium polyacrylate, acrylate / alkyl (C10-30) acrylate crosspolymer), (acrylate / stearyl methacrylate polyether-20) copolymer, (acrylate / stearyl methacrylate polyether-20) crosspolymer, (acrylate / stearyl itaconate polyether-20) copolymer, (acrylate / beheneth-25 methacrylate) copolymer, (acrylate / hydroxyalkyl acrylate) copolymer, (acrylate / vinyl neodecanoate) crosspolymer, (methacryloyloxyethylcarboxybetaine / alkyl methacrylate) copolymer, etc. Among these, carboxyvinyl polymer (carbomer), sodium polyacrylate, acrylate / alkyl (C10-30) acrylate crosspolymer) are preferred because of their high dispersion state improvement effect, and carboxyvinyl polymer (carbomer) is particularly preferred.

[0040] The above-mentioned polymers may be used alone or in combination of two or more.

[0041] The content of the acrylic polymer as component (d) is preferably 0.003% by mass or more and 0.04% by mass or less, and more preferably 0.004% by mass or more and 0.03% by mass or less, relative to the total amount of the powder dispersion composition. By making the content of component (d) within the above range, the dispersion state of the hydrophobized powder can be improved. In particular, by making the content of component (d) at least 0.003% by mass, the anti-caking property can be improved, and by making the content at most 0.04% by mass, the initial dispersibility can be particularly improved.

[0042] Furthermore, the ratio of the content of the acrylic polymer of the component (d) to the content of the hydrophobized metal oxide powder of the component (a) ([content of the component (d)] / [content of the component (a)]) is preferably 1.2×10 -4 Above 2.3×10 -3 Below, more preferably 1.5×10 -4 Above 1.5×10 -3 Below, more preferably 2×10 -4 Above 2×10 -3 By making the ratio within the above range, the dispersion state of the hydrophobized powder can be improved. In particular, by making the ratio within 1.2×10 -4 Above, the dispersion stability can be improved particularly by -3 The following can improve initial dispersibility, anti-caking properties and dispersion stability.

[0043] The ratio of the content of the hydroxycarboxylate salt of the component (c) to the content of the acrylic polymer of the component (d) ([content of the component (c)] / [content of the component (d)]) is preferably 4 to 40, more preferably 5 to 35. By setting the ratio within the above range, the dispersion state of the hydrophobized powder can be improved. In particular, by setting the ratio to 4 or more, the initial dispersibility can be improved, and by setting the ratio to 40 or less, the anti-caking property can be improved.

[0044] <Other ingredients>

[0045] The powder dispersion composition of the present embodiment is as above-mentioned water-based dispersion composition, can contain water-based component.As water-based component, if water-based component is the water-based component commonly used in the external composition of cosmetics, quasi-drugs, etc., then there is no particular restriction.Water-based component contains water, also in the scope that does not hinder the effect of the present embodiment, can contain water-soluble alcohol, thickener, wetting agent, chelating agent, preservative, antioxidant, pigment etc.The content of water-based component in powder dispersion composition can be preferably 45 mass % or more and 95 mass % or less, more preferably 50 mass % or more and 90 mass % or less relative to the total amount of powder composition.

[0046] As water, purified water, ion exchange water, tap water, etc. can be used. The content of water in this embodiment is preferably 20 mass % to 70 mass %, more preferably 30 mass % to 60 mass %, based on the total amount of the powder dispersion composition.

[0047] Examples of the water-soluble alcohol include lower alcohols, polyols, polyol polymers, alcohol alkyl ethers, alcohol ether esters, glycerol monoalkyl ethers, sugar alcohols, monosaccharides, oligosaccharides, polysaccharides, and derivatives thereof.

[0048] Examples of the lower alcohol include ethanol, propanol, isopropanol, isobutanol, t-butanol, etc. Examples of the polyol include divalent alcohols (e.g., dipropylene glycol, 1,3-butanediol, ethylene glycol, propylene glycol, 1,2-butanediol, butanediol, 2,3-butanediol, pentanediol, 2-butene-1,4-diol, hexanediol, octanediol, etc.), trivalent alcohols (e.g., glycerol, trimethylolpropane, etc.), etc.

[0049] Furthermore, the powder which has not been subjected to the above-mentioned hydrophobic treatment may be added as a pigment, for example.

[0050] <Cosmetics>

[0051] The above-mentioned powder dispersion composition is suitable for the preparation of cosmetics. That is, one embodiment of the present invention may be a cosmetic containing the above-mentioned powder dispersion composition. For example, cosmetics are obtained as a composition containing both an oil phase and an aqueous phase by adding an oil-based component to the above-mentioned powder dispersion composition. The above-mentioned powder dispersion composition is suitable for the preparation of preferably an oil-in-water emulsion composition or an oil-in-water emulsion composition, especially the preparation of a difficult oil-in-water emulsion composition with a large content of hydrophobized powder. In addition, the cosmetics in this specification not only include cosmetics, basic cosmetics (foundation, base makeup, etc.) that improve the ultraviolet absorption function, and color cosmetics (eye shadow, blush, etc.), but also sunscreen compositions (sunscreen compositions). In the powder dispersion composition of the present embodiment, the content of the metal oxide powder treated by hydrophobization is high and uniformly dispersed, so the operation in the preparation of cosmetics is easy. In addition, in the obtained cosmetics, it is also easy to obtain a state in which the content of the metal oxide powder treated by hydrophobization is high and uniformly dispersed, which can improve the function of the metal oxide powder.

[0052] [Example]

[0053] The components shown in Tables 1 to 3 were mixed by a common method to prepare powder compositions of Examples and Comparative Examples, and the powder compositions were evaluated.

[0054]

Table 1

[0055]

[0056] ( * 1): STR 100C-LP (manufactured by Sakai Chemical Industry Co., Ltd.)

[0057] ( * 2): MT-100EMG (made by TAYCA Co., Ltd.)

[0058] ( * 3): MZX 508OTS (made by Daito Chemical Industry Co., Ltd.)

[0059] ( * 4): WSX MZ-500 (made by TAYCA Co., Ltd.)

[0060] ( * 5): MZY-510M3S (made by TAYCA Co., Ltd.)

[0061] ( * 6): DOWSIL (registered trademark) ES-5373 (manufactured by Dow Chemical Company) * 7): NIKKOL-BB20 (manufactured by Nikko Chemicals Co., Ltd.)

[0062] (* 8): EMALEX (registered trademark) GM-5 (manufactured by Nippon Emulsion Co., Ltd.) * 9): Silicone SC9450N (manufactured by Shin-Etsu Chemical Co., Ltd.)

[0063] ( * 10): Carbopol (registered trademark) 980 (manufactured by Lubrizol Advanced Materials)

[0064]

Table 2

[0065]

[0066]

Table 3

[0067]

[0068] ( * 11) Pemulen (registered trademark) TR-2 (manufactured by Lubrizol Advanced Materials)

[0069] ( * 12) Aristoflex (registered trademark) AVC (manufactured by Clariant)

[0070] The specific evaluation method is as follows. The evaluation results are shown in Tables 1 to 3.

[0071] <Dispersibility Evaluation>

[0072] Prepare the powder dispersion composition (original sample) just after preparation of each example, and the sample (diluted sample) in which the original sample is diluted to 10,000 times with pure water. Then, the dispersibility is evaluated based on the visual appearance observation of the original sample and the dynamic light scattering (DLS) measurement of the diluted sample. In the DLS measurement, DLS-8000 (manufactured by Otsuka Electronics, Ar ion laser (488nm)) is used as a measuring device, and the cumulative (Cumlant) particle size with a scattering angle of 90° is used as the particle size (Dp1) for evaluation. The evaluation is based on the following indicators:

[0073] A: The original sample is uniform, and the particle size (Dp1) of the powder in the diluted sample is less than 150nm

[0074] B: The original sample is uniform, and the particle size (Dp1) of the powder in the diluted sample is greater than 151nm and less than 250nm

[0075] C: Tiny aggregates are visually confirmed in the original sample, or the original sample is uniform, but the particle size (Dp1) in the diluted sample is greater than 251nm

[0076] D: The powder in the original sample is clearly separated and aggregated

[0077] <Evaluation of Anti-blocking Property>

[0078] For the powder dispersion composition with the above dispersibility evaluation of "A" or "B", the anti-caking property was evaluated. 50 g of the powder dispersion composition of each example was filled into a 50 mL glass spiral tube and stored at room temperature for 1 month. After 1 month of storage, the powder sedimentation at the bottom of the glass spiral tube container was confirmed by appearance confirmation. For the composition confirmed to have sedimentation, the state was observed after stirring with a medicine spoon for a specified time. The evaluation was performed based on the following indicators:

[0079] A: No powder sedimentation layer is found at the bottom of the container, or a powder sedimentation layer is found at the bottom of the container, but after stirring, the deposited powder layer disappears within 10 seconds, and the sample is in a uniform state.

[0080] B: The powder sedimentation layer is confirmed, but after stirring, the sedimentation powder layer disappears within more than 10 seconds and less than 60 seconds, and the sample is in a uniform state.

[0081] C: After the stirring operation is continued for 60 seconds, part of the deposited powder layer still remains, or the aggregates float, and the sample is not in a uniform state.

[0082] D: The deposited powder layer in the sample is hard and difficult to scoop and stir with a spoon

[0083] <Dispersion stability evaluation>

[0084] For the powder dispersion composition whose anti-caking property is evaluated as "A" or "B", the dispersion stability is evaluated. After the powder dispersion composition of each example is stored at 50°C for 1 month in the same order as in the anti-caking property evaluation, each sample is stirred with a spatula to redisperse the deposited powder layer. The redispersed sample obtained by redispersion is diluted 10,000 times with pure water to prepare a diluted sample. The diluted sample is subjected to DLS measurement in the same order as in the above-mentioned "dispersibility" evaluation to obtain its particle size Dp3. Compare with the particle size Dp1 in the above-mentioned dispersibility evaluation. More specifically, the particle size change rate is calculated according to the following formula:

[0085] Particle size change rate (%) = (Dp3-Dp1) / Dp1×100

[0086] The evaluation is based on the following indicators:

[0087] A: Particle size variation rate is less than 30%

[0088] B: Particle size variation rate is greater than 30% and less than 50%

[0089] C: Particle size change rate is greater than 50%

[0090] D: After being stored at 50°C for one month, the sample clearly gelled and sampling was difficult.

[0091] In the evaluation, those evaluated as A or B based on the overall dispersibility, anti-caking and dispersion stability were judged to show a good dispersion state, and those evaluated as A based on the overall dispersibility, anti-caking and dispersion stability were judged to show an excellent dispersion state.

[0092] The present invention has been described above based on specific embodiments and examples, but these embodiments and examples are given only as examples, and the present invention is not limited to the above embodiments and examples. Various changes, corrections, substitutions, deletions, additions and combinations may be made within the scope of the disclosure of the present invention.

[0093] This application claims priority based on Japanese Patent Application No. 2022-139465 filed on September 1, 2022, the entire contents of which are incorporated herein by reference.

Claims

1. A powder dispersion composition comprising (a) a hydrophobized metal oxide powder, (b) a polyether-modified silicone having an HLB of 5 to 17, (c) a hydroxycarboxylate having 2 to 10 carbon atoms, and (d) a polymer containing a constituent unit derived from (meth)acrylic acid and / or a constituent unit derived from an alkyl (meth)acrylate, or a salt thereof, The ratio of the content of the component (d) to the content of the component (a) is 1.2×10 -4 Above 2.3×10 -3 the following, The ratio of the content of the component (c) to the content of the component (a) is 1.2×10 -3 Above 2.3×10 -2 the following. 2 . The powder dispersion composition according to claim 1 , wherein the polyether chain contained in the component (b) is a polyoxyethylene chain. 3 . The powder dispersion composition according to claim 2 , wherein the ingredient (b) is PEG-12 polydimethylsiloxane. 4 . The powder dispersion composition according to claim 1 , wherein the component (d) is a polymer comprising a non-substituted structural unit derived from (meth)acrylic acid and / or a structural unit derived from an alkyl (meth)acrylate. 5 . The powder dispersion composition according to claim 4 , wherein the component (d) is at least one selected from the group consisting of carbomer, acrylates / C10-30 alkyl acrylate crosspolymer, and sodium polyacrylate. The powder dispersion composition according to claim 1 or 2, wherein the component (c) is a citrate. 7 . The powder dispersion composition according to claim 1 , wherein the component (a) is a powder having an average primary particle size of 1 μm or less.

8. The powder dispersion composition according to claim 1 or 2, containing 20% ​​by mass or more and 70% by mass or less of water.

9. A cosmetic comprising the powder dispersion composition according to claim 1 or 2.

10. The cosmetic according to claim 9, which is a water-in-oil emulsified composition.

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