Sunscreen cosmetic

Abstract

A sunscreen cosmetic containing the following components (A), (B), and (C). (A) 0.1 to 10 mass% of a polyalkylene glycol derivative represented by formula (I). (B) 2-40% by mass of an ultraviolet protective agent. And (C) 0.01 to 10 mass% of a water-soluble thickening agent. (I) Z-{O-(EO) a-(BO) k-H} m (In the formula, Z represents a residue obtained by removing hydroxyl groups from a polyhydric alcohol having 3 to 6 hydroxyl groups and 3 or more carbon atoms; m represents an integer of 3-6; eO represents an oxyethylene group; bO represents an oxybutenyl group; eO and BO are bonded in a block shape. A represents the average number of moles of EO added, k represents the average number of moles of BO added, a is an integer of 1-50, and k is an integer of 1-50. In addition, the mass ratio of (EO) a is 10-75 parts by mass per 100 parts by mass of the total of (EO) a and (BO) k.

Description

Technical Field

[0001] This invention relates to a sunscreen cosmetic. Background Technology

[0002] Among polymers, some exhibit phase transitions in response to external stimuli such as heat, pH, light, and water. The development of temperature sensors, separation membranes, adsorbents, drug release agents, water-absorbing materials, water-retaining agents, humidifiers, and indicators utilizing this phase transition phenomenon is actively underway. These polymers that exhibit phase transitions in response to stimuli are called stimulus-responsive polymers. As a stimulus-responsive polymer in response to thermal stimuli, an active polymer containing vinyl ethers with oxyethylene chains is known. This active polymer has a cloud point; in aqueous solution, it exhibits hydrophilicity below the cloud point and hydrophobicity above the cloud point.

[0003] Patent document 1 discloses a method for modifying the wettability of a film surface formed in response to thermal stimulation in various general-purpose resin substrates by using a diblock copolymer of vinyl ethers containing oxyethylene chains and vinyl ethers containing azobenzene structures.

[0004] Stimulus-responsive polymers are sometimes used in cosmetics. For example, Patent Document 2 discloses a cosmetic product whose UV protection effect is enhanced by the action of moisture and heat through the combination of an olefinic oxygen derivative with a specific structure, a UV protectant, and an oil-phase thickener.

[0005] Patent document 3 discloses a cosmetic product that contains a stimuli-responsive polymer that responds to pH stimulation due to the presence of carboxyl groups. This cosmetic product exhibits water resistance to weakly acidic sweat and the like in the range of 0°C to 40°C and can be easily washed off with weakly alkaline soapy water.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2005-154603

[0009] Patent Document 2: International Publication No. 2020 / 032244

[0010] Patent Document 3: Japanese Patent Application Publication No. 2017-149649 Summary of the Invention

[0011] The problem the invention aims to solve

[0012] Traditionally, sunscreens and other cosmetics have incorporated UV protectants such as UV absorbers and UV scatterers, which protect the skin from harmful UV rays. However, when the film formed by sunscreens on the skin comes into contact with water or sweat, the UV absorbers and scatterers inevitably leak out, reducing their UV protection effectiveness. Therefore, various attempts have been made to improve the water resistance of sunscreens and other products to prevent the leakage of UV absorbers and scatterers.

[0013] By incorporating a film-forming agent that imparts water resistance, it is possible to prevent the UV protectant from being washed away by sweat or external moisture. For example, the cosmetic described in Patent Document 2, which enhances the UV protection effect through moisture and heat, forms a film that is not easily detached by sweat or water and has high water resistance.

[0014] However, the film formed by highly water-resistant cosmetics cannot be easily removed with regular cleansers or soaps and must be removed with a special makeup remover. In this regard, the cosmetic described in Patent Document 3 is said to be washable with mildly alkaline soapy water. However, considering the burden on the skin during washing, it is desirable for cosmetics to possess excellent water resistance while also being easily washable with water.

[0015] The purpose of this invention is to provide a sunscreen cosmetic that has excellent water resistance and can be easily washed off with water.

[0016] Solution to the problem

[0017] That is, the present invention is as follows.

[0018] [1] A sunscreen cosmetic, characterized in that it contains the following ingredients (A), (B) and (C):

[0019] (A) Polyalkylene glycol derivatives of formula (I): 0.1–10% by mass;

[0020] (B) UV protectant: 2-40% by mass;

[0021] (C) Water-soluble thickener: 0.01–10% by mass

[0022] Z-{O-(EO) a -(BO) k -H} m (I)

[0023] (In the formula, Z represents the residue after removing the hydroxyl groups from a polyol having 3 to 6 hydroxyl groups and more than 3 carbon atoms; m represents an integer from 3 to 6; EO represents oxyvinyl; BO represents oxybutenyl; EO and BO are bonded in a block form; a represents the average molar number of EO additions; k represents the average molar number of BO additions; a is an integer from 1 to 50; k is an integer from 1 to 50; relative to (EO) a with(BO) k Total weight 100 parts by mass, (EO) a The mass ratio is 10–75 parts by mass.

[0024] Invention Effects

[0025] According to the present invention, a sunscreen cosmetic product can be obtained which has excellent water resistance and can also be easily washed off with water. Detailed Implementation

[0026] [Sunscreen cosmetics]

[0027] This invention provides a sunscreen cosmetic.

[0028] The cosmetic of the present invention contains: (A) a polyalkylene glycol derivative, (B) a UV protectant and (C) a water-soluble thickener.

[0029] [(A) Polyalkylene glycol derivative]

[0030] In the sunscreen cosmetic of the present invention, component (A) is a polyalkylene glycol derivative as shown in formula (I).

[0031] Z-{O-(EO) a -(BO) k -H} m (I)

[0032] The polyalkylene glycol derivative shown in formula (I) functions as a temperature-responsive surface modifier. According to the inventors' novel insights, by appropriately combining this polyalkylene glycol derivative with other ingredients, cosmetics capable of forming a film exhibiting high water resistance, improved UV protection upon contact with water or sweat compared to immediate application, and easy washability with water can be achieved. It should be noted that a surface modifier refers to a component that, by adding a small amount to a liquid, imparts functionality to the coated film.

[0033] Furthermore, in this invention, "temperature responsiveness" is different from the aforementioned cloud point phenomenon. It refers to the phenomenon that the hydrophilicity or hydrophobicity of a film formed by applying cosmetics or the like changes to hydrophilicity or hydrophobicity at a certain temperature.

[0034] In the formula, Z represents a residue from a polyol having 3 to 6 hydroxyl groups and having 3 or more carbon atoms after removing the hydroxyl groups. Examples of polyols include: glycerol and trimethylolpropane having 3 hydroxyl groups; diglycerol, erythritol, pentaerythritol, sorbitan, and methyl glucoside having 4 hydroxyl groups; xylitol and triglycerides having 5 hydroxyl groups; and sorbitol, inositol, and dipentaerythritol having 6 hydroxyl groups. Preferably, Z is a residue from an alcohol having 4 to 6 or more hydroxyl groups after removing the hydroxyl groups. Considering that a film with high surface uniformity can be easily formed on uneven substrates and temperature responsiveness can be improved, thereby enhancing the UV protection effect when incorporated into sunscreen cosmetics (hereinafter also referred to as "cosmetics") through contact with water or sweat, it is easier to improve the UV protection effect than immediately after application. From this point of view, Z is further preferably a residue from an alcohol having 4 hydroxyl groups after removing the hydroxyl groups, particularly preferably a residue from diglycerol or pentaerythritol after removing the hydroxyl groups, and most preferably a residue from pentaerythritol after removing the hydroxyl groups.

[0035] The value of m is 3 to 6, preferably 4 to 6, and more preferably 4. When m is 3 or more, the temperature responsiveness is improved, and it is easy to generate a hydrophobic-hydrophilic transition that senses temperature changes. When m is 6 or less, it is easy to form a highly uniform surface even on uneven substrates. Furthermore, when m is 3 or more and 6 or less, it is easy to achieve both high water resistance and high cleanability when incorporated into cosmetics.

[0036] Furthermore, EO represents oxyvinyl and BO represents oxybutenyl, but from the viewpoint of easy polymerization, BO is preferably 1,2-oxybutenyl. Furthermore, for easy polymerization, EO and BO are bonded in a block form. 'a' represents the average molar number of EO additions, and 'k' represents the average molar number of BO additions. 'a' is an integer from 10 to 50, preferably from 10 to 40, particularly preferably from 20 to 30, and 'k' is an integer from 3 to 40, preferably from 5 to 30, further preferably from 10 to 25, particularly preferably from 10 to 15. Further, relative to (EO)... a with(BO) k Total weight 100 parts by mass, (EO) a The mass ratio is 10-75 parts by mass, preferably 15-60 parts by mass, more preferably 20-60 parts by mass, and particularly preferably 30-60 parts by mass. By combining EO and BO, temperature responsiveness can be improved, and a film with high surface uniformity can be easily formed even on uneven substrates. Furthermore, by combining EO and BO, the water resistance of the film can be improved.

[0037] Relative to the residues (Z) after removing the hydroxyl group from the polyol, the polyoxyalkylene glycol derivative of formula (I) of the present invention is sequentially configured with EO blocks and BO blocks. By adopting the above sequence, a film with high surface uniformity can be formed.

[0038] The polyoxyalkylene glycol derivative of formula (I) of the present invention can be manufactured by known methods. For example, it can be obtained by sequentially adding polyoxyethylene and oxybutene to a polyol having 3 to 6 hydroxyl groups under a base or acid catalyst.

[0039] In the cosmetic of the present invention, the polyalkylene glycol derivative contained as ingredient (A) imparts water resistance and easy-to-wash properties to the film formed by the cosmetic. Furthermore, the aforementioned polyalkylene glycol derivative, upon contact with moisture such as water or sweat, forms a more uniform film than the surface before contact, thereby enhancing the UV protection effect provided by the film formed by the cosmetic.

[0040] Relative to the total mass of the cosmetic of the present invention, the content of (A) polyalkylene glycol derivative is preferably 0.1 to 10% by mass, more preferably 0.5 to 8% by mass, and even more preferably 1 to 5% by mass. When the content of the above-mentioned polyalkylene glycol derivative is 0.1% by mass or more, the water resistance of the coating is improved, and the UV protection is enhanced when water is applied. When the content of the above-mentioned polyalkylene glycol derivative is 10% by mass or less, the coating is easy to clean.

[0041] [(B) Ultraviolet Protective Agent]

[0042] In the cosmetic of the present invention, the ultraviolet (UV) protectant contained as ingredient (B) can be either a UV absorber or a UV scatterer. The UV protectant (B) imparts the UV absorption or scattering properties to the cosmetic, thereby giving the cosmetic a protective property against UV radiation on the substrate.

[0043] Ultraviolet absorbers can be in liquid or solid form.

[0044] In this specification, "liquid" refers to a state in which the substance is fluid at 1 atmosphere and 25°C, that is, a state at a temperature above its melting point (for amorphous substances without a melting point, it refers to a state at a temperature above its melting point). Conversely, "solid" refers to a state in which the substance is not fluid at 1 atmosphere and 25°C, that is, a state at a temperature below its melting point (for amorphous substances without a melting point, it refers to a state at a temperature below its melting point).

[0045] Examples of liquid ultraviolet absorbers include: cinnamic acid-based ultraviolet absorbers such as 2-ethylhexyl p-methoxycinnamate, 2-ethoxyethyl p-methoxycinnamate, a mixture of isopropyl p-methoxycinnamate / diisopropyl p-methoxycinnamate, and methylbis(trimethylsiloxy)silyl isopentyl trimethoxycinnamate; p-aminobenzoic acid-based ultraviolet absorbers such as amyl p-dimethylaminobenzoate and 2-ethylhexyl p-dimethylaminobenzoate; salicylic acid-based ultraviolet absorbers such as ethylene glycol salicylate, 2-ethylhexyl salicylate, benzyl salicylate, and homomenthyl salicylate; octocrylene; and dimethicodiethylbenzalmalonate, etc. From the viewpoint that the UV protection effect of the coating can be improved by contact with moisture such as water or sweat compared to when it is freshly coated, 2-ethylhexyl methoxycinnamate, octocrylene, and benzyl malonate polysiloxane are preferred, and 2-ethylhexyl methoxycinnamate and octocrylene are particularly preferred.

[0046] Examples of solid ultraviolet absorbers include: hexyl diethylaminohydroxybenzoylbenzoate, bis(ethylhexyloxyphenol) methoxyphenyl triazine, methylenebisbenzotriazolyltetramethylbutylphenol, ethylhexyl triazine ketone, 2-ethylhexyl dimethoxybenzyldioxazoalkylpropionate, and tert-butylmethoxydibenzoylmethane. From the viewpoint that the UV protection effect of the coating can be easily improved by contact with moisture such as water or sweat compared to immediate application, hexyl diethylaminohydroxybenzoylbenzoate, bis(ethylhexyloxyphenol) methoxyphenyl triazine, ethylhexyl triazine ketone, and tert-butylmethoxydibenzoylmethane are particularly preferred.

[0047] From the viewpoint that the UV protection effect of the coating can be improved by contact with moisture such as water or sweat compared to when it is freshly applied, cosmetics preferably contain at least a liquid UV absorber, and more preferably both a liquid UV absorber and a solid UV absorber.

[0048] Ultraviolet (UV) scattering agents are not particularly limited. Specific examples of UV scattering agents include: particulate metal oxides, such as zinc oxide, titanium oxide, iron oxide, cerium oxide, tungsten oxide, etc.

[0049] The ultraviolet (UV) scattering agent can be an untreated UV scattering agent or a UV scattering agent with various hydrophobic surface treatments, but a hydrophobic surface treatment is preferred. As a surface treatment agent, commonly used surface treatment agents in the cosmetics field can be used, such as organosilicones like polydimethylsiloxane and alkyl-modified organosilicon, alkoxysilanes like octyltriethoxysilane, dextrin fatty acid esters like palmitic dextrin, and fatty acids like stearic acid.

[0050] From the perspective of UV protection effectiveness, hydrophobic zinc oxide and hydrophobic titanium oxide are preferred.

[0051] As a UV protectant (B), cosmetics may contain only UV absorbers, only UV scatterers, or both UV absorbers and UV scatterers. From the viewpoint that the UV protection effect of the coating can be improved by contact with moisture such as water or sweat compared to when it is first applied, cosmetics preferably contain at least a UV absorber, and more preferably contain both a UV absorber and a UV scatterer.

[0052] Relative to the total mass of the cosmetic of the present invention, the content of (B) the ultraviolet protectant is preferably 2 to 40% by mass, more preferably 3 to 38% by mass, and even more preferably 5 to 30% by mass. When the content of the ultraviolet protectant is 2% by mass or more, the ultraviolet protection of the film is improved. In addition, when the content of the ultraviolet protectant is 40% by mass or less, the film is easy to clean.

[0053] [(C) Water-soluble thickener]

[0054] In the cosmetic of the present invention, the water-soluble thickener contained as ingredient (C) is a water-soluble thickener that is commonly used in cosmetics.

[0055] Examples of water-soluble thickeners include: polysaccharide-based polymers, vinyl-based polymers, polyoxyethylene-polyoxypropylene-based polymers, acrylic polymers, inorganic polymers, acrylamide-based polymers, and hydrophobically modified polyether urethanes.

[0056] Examples of polysaccharide-based thickeners include: cellulose-based thickeners such as crystalline cellulose, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, and carboxymethyl cellulose; and natural polysaccharide-based thickeners such as gellan gum, carrageenan, guar gum, locust bean gum, gum arabic, xanthan gum, dextran, and succinosaccharide.

[0057] Examples of vinyl polymers include polyvinyl methyl ether and carboxyvinyl polymers.

[0058] Examples of polyoxyethylene and polyoxypropylene polymers include: polyoxyethylene polyoxypropylene glycol (150E.O.)(30P.O.) and polyoxyethylene polyoxypropylene glycol (240E.O.)(60P.O.).

[0059] Examples of acrylic polymers include: acrylates / c10-30 alkyl acrylate crosspolymers (acrylates / alkyl acrylate (C10-30)), alkyl acrylate / alkyl methacrylate polyoxyethylene ester copolymers, alkyl acrylate / alkyl itaconic acid polyoxyethylene ester copolymers, and stearyl alcohol polyether-10 allyl ether / alkyl acrylate copolymers.

[0060] Examples of inorganic polymers include bentonite, magnesium aluminum silicate, lithium saponite, hydropyrite, and silicic anhydride.

[0061] Examples of acrylamide-based polymers include: copolymers of hydroxyethyl acrylate and acryloyl dimethyl taurate, copolymers of acrylate and acryloyl dimethyl taurate, copolymers of acrylamide and acrylate, copolymers of acrylic acid, acrylamide, acrylate, and acryloyl dimethyl taurate, and copolymers of vinylpyrrolidone and acryloyl dimethyl taurate. More specifically, examples include: (hydroxyethyl acrylate / sodium acryloyl dimethyl taurate) copolymer, (sodium acrylate / sodium acryloyl dimethyl taurate) copolymer, (acrylamide / ammonium acrylate) copolymer, (acrylic acid / acryloyl dimethyl taurate / dimethylacrylamide) cross-linked polymer, (ammonium acryloyl dimethyl taurate / vinylpyrrolidone) copolymer, (acrylic acid / acrylamide / sodium acrylate / sodium acryloyl dimethyl taurate) copolymer, (ammonium acryloyl dimethyl taurate / behenol polyether-25 methacrylate) cross-linked copolymer, and (ammonium acryloyl dimethyl taurate / stearyl alcohol polyether-25 methacrylate) cross-linked polymer, etc.

[0062] Hydrophobically modified polyether urethane is a polymer with urethane bonds modified by hydrophobic groups, such as copolymers of PEG-240 / decyltetradecyl alcohol polyether-20 / HDI.

[0063] From the viewpoint that the UV protection effect of the coating can be improved by contact with moisture such as water or sweat compared to when it is freshly coated, polysaccharide-based polymers, vinyl-based polymers, acrylic-based polymers and acrylamide-based polymers are preferred, and polysaccharide-based polymers and acrylamide-based polymers are more preferred.

[0064] Relative to the total mass of the cosmetic of the present invention, the content of (C) water-soluble thickener is preferably 0.01 to 10% by mass, more preferably 0.02 to 7.5% by mass, and even more preferably 0.05 to 5% by mass. When the content of water-soluble thickener is 0.01% by mass or more, the UV protection effect of the film is easily improved by contact with water or sweat and other moisture compared to when it is freshly applied. When the content of water-soluble thickener is 10% by mass or less, the water resistance and easy cleaning properties of the film are easily balanced.

[0065] The cosmetics of the present invention may also contain ingredients other than (A), (B), and (C). Examples of such ingredients include: moisturizers, thickeners other than (C), emulsifiers, oils, pH adjusters, surfactants, antioxidants, chelating agents, preservatives, whitening ingredients, pigments, colorants, fragrances, etc.

[0066] The cosmetics of the present invention can be formulated as needed. Examples of dosage forms include: liquids, dispersions, emulsions, creams, gels, sticks, pressed powders, powders, sprays, aerosols, etc. These formulations can be manufactured using conventional methods using the above-mentioned ingredients (A), (B), (C), and other commonly used ingredients. Furthermore, the cosmetics of the present invention can also be used as a makeup base with sun protection effects.

[0067] Example

[0068] The following examples illustrate the present invention, but the invention is not limited to these examples. It should be noted that the values ​​listed in the tables of the examples are all relative to the total mass of the cosmetic product.

[0069] [Synthesis of Compounds 1 through 9]

[0070] 45g of pentaerythritol, 50g of toluene, and 8.0g of potassium hydroxide were added to an autoclave. After purging the autoclave with dry nitrogen, 1292g of ethylene oxide was added dropwise at 110°C using a dropping device while stirring for 2 hours. Next, 1160g of 1,2-epoxybutane was added dropwise at 110°C while stirring for 2 hours. The reactants were then removed from the autoclave and neutralized with hydrochloric acid to a pH of 6–7. To remove toluene and water, the mixture was subjected to reduced pressure treatment at 115°C for 1 hour. Finally, the salts were removed by filtration, yielding 2345g of compound 1. By changing the type of polyol used as a starting material and the amounts of ethylene oxide and 1,2-epoxybutane, compounds 2–7 were synthesized.

[0071] Compounds 8 and 9 were synthesized using propylene oxide under the same conditions as those for compounds 1 through 7. For compound 8, a random copolymer was synthesized by simultaneously adding ethylene oxide and propylene oxide. Furthermore, for compound 9, a random copolymer was synthesized by simultaneously adding ethylene oxide, 1,2-epoxybutane, and propylene oxide.

[0072] [Compound 10]

[0073] 4-Phenylazobenzoic acid PEG-12 methyl ether was used as compound 10.

[0074] The types of polyols, m, a, and k values ​​of those containing the Z residue in formula (I) for compounds 1 through 9 are shown in Table 1. Note that for compounds 8 and 9, the average molar number (l) of the oxypropylene group (PO) is also shown. The values ​​of a, k, and l for compounds 1 through 9 were calculated based on the hydroxyl value.

[0075] [Table 1]

[0076]

[0077] The following evaluations were conducted on compounds 1 through 10.

[0078] [Preparation of sunscreen cosmetics]

[0079] Compounds 1 to 10 were mixed with components (A), (B), (C), and oils, emulsifiers, and lipophilic additives other than components (A and (B)) in Tables 1 to 5. This mixture was then added to an oil phase prepared by heating to 75°C to 80°C and mixed. Subsequently, an aqueous phase prepared by heating to 75°C to 80°C was added, and the mixture was homogenized using a homogenizer. Cosmetics 1 to 19 were thus prepared. It should be noted that dodecane (PARAFOL12 manufactured by Sasol) was used as the oil.

[0080] It should be noted that the oils, emulsifiers, lipophilic additives, and hydrophilic additives other than ingredients (B), (C), (A), and (B) in the table are all commercially available products intended for cosmetic use.

[0081] The following evaluations were conducted on cosmetics 1 through 19.

[0082] [Water resistance evaluation of sunscreen cosmetics]

[0083] For cosmetics 1 to 19, at 2mg / cm 2After being coated onto a PMMA plate (HELIOPLATE HD6 manufactured by Labsphere), the sample was left to stand in the dark for 20 minutes. The SPF (Sun Protection Factor) was measured using an SPF analyzer (UV-2000S manufactured by Labsphere). Nine measurements were taken on the plate, and the [Pre-water bath SPF] was obtained from the average value.

[0084] Next, the plate after measurement was immersed in water at 30°C and stirred directly in the water for 80 minutes (using a Three-One Motor, 100 rpm). Then, it was dried for about 60 to 120 minutes until the water droplets on the surface disappeared, and the SPF was measured again to obtain the [SPF after water bath]. The rate of change of SPF after water bath (30°C) was calculated according to the following formula (II).

[0085] SPF change rate after water bath (30℃) = [SPF after water bath] / [SPF before water bath] × 100 ···(II)

[0086] Water resistance is evaluated according to the following criteria based on the SPF change rate after water bath (30℃).

[0087] [Evaluation Criteria]

[0088] ◎:More than 130%;

[0089] 〇: 115% or more but less than 130%;

[0090] △: 100% or more but less than 115%;

[0091] ×: Less than 100%.

[0092] [Evaluation of the washability of sunscreen cosmetics]

[0093] For mixing 0.05% by weight of Brilliant Blue (a water-soluble blue pigment) into cosmetics 1 to 19, at a concentration of 2 mg / cm³ 2 After being coated onto a PMMA plate (HELIOPLATE HD6 manufactured by BlueFocus Optics), the sample was left to stand in the dark for 20 minutes, then immersed in water at 20°C and stirred directly in the water for 80 minutes (using a Three-One Motor, 100 rpm). Subsequently, it was dried for approximately 60–120 minutes until the water droplets on the surface disappeared. The difference in lightness of the coated area before and after the water bath was measured using a spectrophotometer (CM-2500c, manufactured by Konica Minolta Corporation).

[0094] Calculate the cleaning rate using the following formula, and evaluate water resistance according to the following criteria.

[0095] Cleaning rate = (1 - ΔEa / ΔEb) × 100

[0096] ΔEa = Lightness of the PMMA board surface after water bath

[0097] ΔEb = Brightness of the PMMA board surface before water bath

[0098] [Evaluation Criteria]

[0099] ◎: Cleaning rate of over 95%;

[0100] 〇: Cleaning rate of 85% or higher but less than 95%;

[0101] △: Cleaning rate of 75% or higher but less than 85%;

[0102] ×: Cleaning rate is less than 75%.

[0103] The composition of cosmetics 1 to 19, as well as the evaluation results of their water resistance and cleansing properties, are shown in Tables 2 to 5.

[0104] [Table 2]

[0105]

[0106] [Table 3]

[0107]

[0108] [Table 4]

[0109]

[0110] [Table 5]

[0111]

[0112] As shown in Tables 2 to 5, cosmetics containing ingredients (A) to (C) can easily enhance their UV protection effect through contact with water, and have high water resistance and good washability.

[0113] As shown in Table 5, cosmetics without ingredient (A) experience a reduction in UV protection effectiveness upon contact with moisture.

[0114] Specifically, in cosmetic 16 (Comparative Example 1), the m value of ingredient (A) is 2, which is below the lower limit; therefore, the water resistance of the sunscreen cosmetic is insufficient. In cosmetic 17 (Comparative Example 2), ingredient (A) does not have a structure derived from EO; therefore, the water resistance of the sunscreen cosmetic is insufficient. In cosmetic 18 (Comparative Example 3), the m value of ingredient (A) is 2, which is below the lower limit, and it does not have a structure derived from BO; moreover, the oxidized alkenyl group has a random structure. Therefore, the water resistance of the sunscreen cosmetic is insufficient. In cosmetic 19 (Comparative Example 4), the oxidized alkenyl group structure of ingredient (A) is not within the scope of this invention and has a random structure. Therefore, the water resistance of the sunscreen cosmetic is insufficient.

[0115] (Specific formula example)

[0116] The following are specific formulation examples of compositions containing temperature-responsive surface modifiers according to the present invention. Tables 6 to 11 show formulation examples of sunscreen cosmetics, makeup bases, dual-layer sunscreen mists, and dual-layer sunscreen sprays. It should be noted that the embodiments of the present invention are not limited to these formulation examples. In the tables, "PEG" represents polyethylene glycol, "PPG" represents polypropylene glycol, "BG" represents butylene glycol, and "DPG" represents dipropylene glycol.

[0117] [Table 6]

[0118]

[0119] [Table 7]

[0120]

[0121] [Table 8]

[0122]

[0123] [Table 9]

[0124]

[0125] [Table 10]

[0126]

[0127] [Table 11]

[0128]

[0129] This application claims priority based on Japanese Application No. 2023-187696, filed on November 1, 2023, the contents of which are incorporated herein by reference.

[0130] Industrial applicability

[0131] This invention provides a sunscreen cosmetic that has excellent water resistance and can be easily washed off with water.

Claims

1. A sunscreen cosmetic containing the following ingredients (A), (B) and (C): (A): Polyalkylene glycol derivatives of formula I: 0.1–10% by mass; (B): Ultraviolet protectant: 2-40% by mass% (C): Water-soluble thickener: 0.01–10% by mass Formula (I): Z-{O-(EO) a -(BO) k -H} m , In the formula, Z represents the residue after removing the hydroxyl groups from a polyol having 3 to 6 hydroxyl groups and more than 3 carbon atoms; m represents an integer from 3 to 6; EO represents oxyvinyl; BO represents oxybutenyl; EO and BO are bonded in a block form; a represents the average molar number of EO additions, k represents the average molar number of BO additions, a is an integer from 1 to 50, and k is an integer from 1 to 50; relative to (EO) a with(BO) k Total weight 100 parts by mass, (EO) a The mass ratio is 10 to 75 parts by mass.

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