Method for producing the composition

Abstract

Provided is a method for producing a composition containing (A) a polyvinyl alcohol, (B) an oil-soluble UV absorber, (C) a solid oil, and (D) water. The method includes emulsifying (B), (C) and (D) in the presence of (A) at a temperature that is at least the melting point of (C).

Description

[Technical Field]

[0001] The present invention relates to a method for producing a composition, particularly a composition used in UV protective cosmetics. [Background technology]

[0002] Sunburn is caused by sunlight, particularly ultraviolet rays, and leads to browning of the skin, loss of skin elasticity, the development of wrinkles, etc. To prevent these, cosmetics containing ultraviolet absorbers are used. Among UV absorbers, oil-soluble UV absorbers have excellent UV absorbing effects, but when blended directly into cosmetics, they can cause irritation and stickiness, posing problems in terms of usability, etc. In response to this, various cosmetic preparations have been studied. For example, Patent Document 1 discloses a UV protective cosmetic preparation containing an ionic surfactant, an oil-soluble UV absorber, a solid oil, and water. This cosmetic preparation is produced by mixing and emulsifying the ionic surfactant, the oil-soluble UV absorber, the solid oil, and water, cooling the mixture, and then mixing it with a water-soluble polymer such as polyvinyl alcohol. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-7969 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the UV protective cosmetic obtained in Patent Document 1 has problems in terms of salt miscibility and storage stability. Therefore, an object of the present invention is to provide a composition, particularly a cosmetic, which has excellent salt miscibility and storage stability even when an oil-soluble ultraviolet absorber is contained therein. [Means for solving the problem]

[0005] This invention solves the above problem by emulsifying (A) polyvinyl alcohol, (B) an oil-soluble ultraviolet absorber, (C) a solid oil agent, and (D) water under specified conditions. That is, the gist of the present invention lies in the following [1] to [3]. [1] A method for producing a composition comprising (A) polyvinyl alcohol, (B) an oil-soluble ultraviolet absorber, (C) a solid oil agent, and (D) water, the method comprising emulsifying (B), (C), and (D) in the presence of (A) at a temperature equal to or higher than the melting point of (C). [2] The method for producing the composition according to [1], wherein the composition is used in a UV protective cosmetic. [Effects of the Invention]

[0006] Since the present invention uses a predetermined manufacturing method, the resulting composition incorporates an oil-soluble UV absorber in the particle center, and the solid oil agent phase-separates into the vicinity of the aqueous phase, forming a core-shell structure with the oil-soluble UV absorber as the core and the solid oil agent as the shell, thereby providing excellent salt miscibility, A composition with excellent storage stability can be obtained. DETAILED DESCRIPTION OF THE INVENTION

[0007] The method for producing the composition of the present invention will be described in detail below. This invention relates to a method for producing an oil-soluble UV absorber-containing composition (hereinafter simply referred to as the "composition") that contains polyvinyl alcohol (component (A)), an oil-soluble UV absorber (component (B)), a solid oil agent (component (C)), and water (component (D)). As the water which is the component (D), pure water, ion-exchanged water, etc. can be used.

[0008] <Raw materials used> [Component (A): Polyvinyl alcohol] The polyvinyl alcohol (PVA) can be obtained by a known method, i.e., by saponifying polyvinyl acetate obtained by polymerizing vinyl acetate. The polyvinyl alcohol blended in the composition of the present invention is not particularly limited, but preferably has a degree of saponification of 70% or more, particularly preferably 80% or more. The upper limit of the degree of saponification is not limited, and although it can be up to 100%, it is particularly preferred that it be approximately 90% or less. In addition, the degree of polymerization is preferably 100 or more, and the upper limit of the degree of polymerization is approximately 4000, which is the upper limit of currently available commercially available products.

[0009] Commercially available PVA products include the Gohsenol series manufactured by Mitsubishi Chemical Corporation (EG-03P, EG-05P, EG-18P, EG-22P, EG-30P, EG-40P, EG-48P, N-300, NL-05, AL-06R, GH-23, GH-22, GH-20R, GH-17R, GM-14R, GL-05, GL-03, KH-20, KH-17, KL-05, KL-03, NK-05R, etc.), and products meeting the above properties include the Kuraray Poval series manufactured by Kuraray Co., Ltd., the Denka Poval series manufactured by Denka Co., Ltd., the Shin-Etsu Poval series manufactured by Shin-Etsu Chemical Co., Ltd., and the Unitika Poval series manufactured by Unitika Ltd. Examples of specially modified PVA include the Gohsenex series (Z-100, Z-200, Z-205, Z-210, Z-220, Z-300, Z-320, Z-410, K-434, L-3266, CKS-50, T-330H, T-330, T-350) manufactured by Mitsubishi Chemical Corporation, and these may be used alone or in combination.

[0010] The amount of PVA in the composition of the present invention is preferably 0.1% by weight or more, particularly preferably 0.3% by weight or more, and is preferably 10% by weight or less, particularly preferably 5% by weight or less. If the amount is less than 0.1% by weight, the suspension envisioned in the present invention will not be obtained, and if it exceeds 10% by weight, the viscosity will be too high, resulting in an undesirable feel when used.

[0011] [Component (B): Oil-soluble UV absorber] The oil-soluble ultraviolet absorber (hereinafter, sometimes simply referred to as "ultraviolet absorber") refers to an ultraviolet absorber having a solubility in water of 5% by weight or less. The oil-soluble UV absorbers approved for cosmetic use include the following commercially available products, which will be described below in accordance with the "INCI nomenclature system." PABA, homosalate (HMS), benzophenone-3 (BENZ-3), butyl methoxydibenzoylmethane (BMDBM), octocrylene (OC), polyacrylamidomethyl benzylidene camphor, ethylhexyl methoxycinnamate (EMC, OMC), isoamyl p-methoxycinnamate (IMC), ethylhexyl triazone (OT, ET), drometrizole trisiloxane, diethylhexyl butamido triazone (DBT), 4-methylbenzylidene camphor (MBC), 3-benzylidene camphor (BC), ethylhexyl salicylate (OS, ES), ethylhexyl dimethyl PABA (OD-PABA, ED-PABA), benzophenone-4 (BENZ-4), methylene bisbenzotriazolyl tetramethylbutylphenol (bisoctyltriazole, BOT), bisethylhexyloxyphenol methoxyphenyl triazone Examples of suitable hydroxybenzoates include bis(ethylhexyl)benzoate (AT), polysilicon 15, diethylaminohydroxybenzoylhexylbenzoate, 1-(4-tert-butylphenyl)-3-(4-methoxyphenyl)propane-1,3-dione, 4-isopropyldibenzoylmethane, 2-hydroxy-4-methoxybenzophenone, 2,4,6-tris(biphenyl)-1,3,5-triazine (TBT), methanone 1,1'-(1,4-piperazinediyl)bis[1-[2-[4-(diethylamino)-2-hydroxybenzoyl]phenyl]] (CAS number 919803-06-8), 1,1-di(carboxy-(2',2'-dimethylpropyl))-4,4-diphenylbutadiene, bisethylhexyloxyphenol methoxyphenyl triazine, merocyanine derivatives, benzylidene malonate, and t-butylmethoxydibenzoylmethane (CAS number 70356-09-1). As the ultraviolet absorber, these compounds and mixtures thereof can be used.

[0012] Particularly preferred are octocrylene, ethylhexyl methoxycinnamate, isoamyl p-methoxycinnamate, octyl methoxycinnamate, isopentyl 4-methoxycinnamate as a mixture of isomers, homosalate, octyl salicylate, 1-(4-tert-butylphenyl)-3-(4-methoxyphenyl)propane-1,3-dione, 4-isopropyldibenzoylmethane, 2-hydroxy-4-methoxybenzophenone, bisethylhexyloxyphenol methoxyphenyl triazine, and mixtures of these UV absorbers.

[0013] In the method for producing the composition according to the present invention, which will be described later, when the solid oil agent (component (C)) solidifies after emulsification at high temperatures, phase separation occurs to form core-shell particles, with the UV absorber as the core and the solid oil agent as the shell, so it is preferable that the UV absorber be a liquid at 20° C. If the UV absorber is a solid at this time, no phase separation occurs during cooling after emulsification, and the UV absorber remains uniformly dispersed within the particles. In consideration of preventing the ultraviolet absorber from coming into contact with the skin when the composition of the present invention is used, it is preferable that the ultraviolet absorber be a liquid at the temperature of use. If the ultraviolet absorber is a solid, it can be dissolved in an oil or the like to impart fluidity to the composition.

[0014] Here, the oil is preferably one that has fluidity at 20°C. Furthermore, there are no particular limitations on the oil as long as it is one that is commonly used in cosmetics, and examples thereof include linear or branched hydrocarbon oils such as liquid paraffin, light isoparaffin, squalane, and squalene; ester oils such as fatty acid esters such as neopentyl glycol dicaprate, isopropyl palmitate, and alkyl benzoate, and polyhydric alcohol fatty acid esters such as pentaerythritol tetra-2-ethylhexanoate; silicone oils such as dimethylpolysiloxane, dimethylcyclopolysiloxane, methylphenylpolysiloxane, methylhydrogenpolysiloxane, and higher alcohol-modified silicone oil; and fluorinated oils such as fluoropolyethers and perfluoroalkyl ether silicones. These include natural oils such as vegetable oils such as jojoba oil and olive oil; and animal oils such as liquid lanolin. Of these, as liquid oil agents other than oil-soluble UV absorbers, linear or branched hydrocarbon oils, ester oils, silicone oils, etc. are preferred from the viewpoint of reducing stickiness and improving compatibility with oil-soluble UV absorbers. These oils may be used alone or in combination.

[0015] The weight ratio (encapsulation rate) of the ultraviolet absorber to the entire core-shell particle can be expressed as a blending ratio, and is preferably 20% by weight or more, and more preferably 30% by weight or more. Also, it is preferably 75% by weight or less, and more preferably 70% by weight or less. If the ultraviolet absorber is less than 20% by weight, the ultraviolet absorption ability tends to be insufficient. On the other hand, if the ultraviolet absorber is more than 75% by weight, the shell thickness becomes thin, and the particle stability tends to decrease.

[0016] The content of the UV absorber in the composition of the present invention is preferably 3% by weight or more, and more preferably 5% by weight or more, based on the total composition, from the viewpoint of suspension stability and stable loading of the UV absorber. It is also preferably 40% by weight or less, and more preferably 30% by weight or less. If the UV absorber content is less than 3% by weight, the UV absorption ability tends to be insufficient. On the other hand, if the UV absorber content is more than 40% by weight, the concentration of the total composition increases, and the particles come into contact with each other more frequently, which tends to reduce stability, such as by reducing the viscosity of the composition due to particle aggregation.

[0017] [Component (C): Solid oil] The solid oil of component (C) is an oil that is solid at 25°C. Such solid oil agents are not particularly limited, and examples thereof include vegetable waxes such as candelilla wax (melting point: 66 to 75°C), rice wax (melting point: 77 to 86°C), sunflower wax (melting point: 65 to 80°C), carnauba wax (melting point: 80 to 86°C), and Japan wax (melting point: 50 to 56°C); animal waxes such as beeswax (melting point: 62 to 65°C) and spermaceti wax (melting point: 42 to 52°C); mineral waxes such as montan wax (82 to 95°C) and ozokerite (melting point: 66 to 78°C); petroleum waxes such as microcrystalline wax (melting point: 60 to 90°C), paraffin (40 to 70°C), and ceresin (60 to 80°C); hydrogenated castor oil (melting point: 85°C), hydrogenated jojoba oil (melting point: 66 to 70°C), and 12-hydroxystearic acid ( synthetic waxes such as lauric acid (melting point: 42-44°C), myristic acid (melting point: 52-54°C), palmitic acid (melting point: 60-63°C), stearic acid (melting point: 67-70°C), and behenic acid (melting point: 75-79°C); higher alcohols such as myristyl alcohol (melting point: 33-45°C), cetanol (melting point: 46-55°C), cetialyl alcohol (melting point: 46-55°C), stearyl alcohol (melting point: 54-62°C), and behenyl alcohol (melting point: 65-72°C); and polyester resins such as polycaprolactone (melting point: 40-60°C). Of these, solid oils having a melting point of 60° C. or higher and 80° C. or lower are preferred as component (C) from the viewpoint of obtaining a stable suspension. Component (B) that corresponds to component (C) is treated as component (B). Examples of compounds that fall under this category include t-butyl methoxydibenzoylmethane (CAS number 70356-09-1) (melting point: 155°C).

[0018] From the viewpoint of improving the stability of the suspension, component (C) preferably contains a total of 3% by weight or more, and more preferably 5% by weight or more, of fatty acids having 20 or fewer carbon atoms (hereinafter sometimes referred to as "C20 or fewer") relative to the total amount of component (C). Examples of component (C) include the aforementioned paraffin and ceresin. The C20 or fewer fatty acids satisfy the requirements of component (C), i.e., are fatty acids that are solid at 25°C.

[0019] On the other hand, when the content of at least one of the branched hydrocarbons such as isoparaffins and the saturated cyclic hydrocarbons such as cycloparaffins contained in the component (C) is 10% by weight or more of the entire component (C), the total amount of fatty acids of C20 or less may be less than 3% by weight of the total amount of component (C), from the viewpoint of improving the stability of the suspension. These are thought to differ depending on how much "branched hydrocarbons (isoparaffins) and saturated cyclic hydrocarbons (cycloparaffins)" are contained in the components. The reason for this is not clear, but it is thought that if there is a lot of isoparaffins and cycloparaffins in the hydrocarbons, the crystals that form when they change from a liquid state to a solid state at high temperatures are small, so the stability of the particles is not impaired. On the other hand, normal paraffins that contain little isoparaffins and cycloparaffins tend to become unstable because the crystals that form when they change from a liquid state to a solid state at high temperatures are large.

[0020] For example, some microcrystalline waxes contain 17% by weight of isoparaffins and 24% by weight of cycloparaffins, and the object of the present invention is achieved even if they do not contain fatty acids of C20 or less. However, even in such cases, the total amount of fatty acids of C20 or less may be 3% by weight or more, preferably 5% by weight or more, based on the total amount of component (C). The amounts of isoparaffins and cycloparaffins can be measured by mass spectrometry.

[0021] Candelilla wax contains 15.0% of fatty acids below C20, rice wax contains 85.5% of fatty acids below C20, sunflower wax contains 0% of fatty acids below C20, carnauba wax contains 8.7% of fatty acids below C20, and beeswax contains over 94.7% of fatty acids below C20 (100% European, 94.7% Oriental). This is based on the information in the Handbook of Oil and Fat Chemistry (Revised 3rd Edition, pp. 133-137) by the Japan Oil Chemists' Association (1990), "Ester Composition of Waxes."

[0022] The above-mentioned vegetable waxes, animal waxes, etc. are mixtures of fatty acids and higher alcohols, and petroleum waxes are hydrocarbons. Furthermore, fatty acids, higher alcohols, and hydrocarbons have a distribution of carbon numbers, which can result in insufficient emulsion stability. Emulsion stability can be improved by appropriately using the above-mentioned C20 or lower fatty acids in combination, preferably at a content of 3% by weight or more in combination with the fatty acids in component (C). The upper limit is preferably 80% by weight, more preferably 70% by weight. Stearic acid and lauric acid are preferred as the C20 or lower fatty acids.

[0023] The component (C) may be used alone or in combination of two or more, and its content in the composition is preferably 3% by weight or more, and more preferably 5% by weight or more, from the viewpoints of the stability of the suspension and the stable loading of the UV absorber, and is preferably 40% by weight or less, and more preferably 30% by weight or less.

[0024] [Optional ingredients] As an optional component to be used in combination with the (A) polyvinyl alcohol, a water-soluble polymer can be used during emulsification to improve the stability of the suspension. Such a water-soluble polymer is not particularly limited, and any of natural polymers, semi-synthetic polymers, and synthetic polymers can be used. Examples of the natural polymer include xanthan gum, carrageenan, algin, and microfibrillated cellulose acid. The semi-synthetic polymers include semi-synthetic polysaccharide polymers, specifically modified polysaccharides such as hydroxycellulose, hydroxypropyl cellulose, sodium carboxymethyl cellulose, methyl cellulose, hydroxymethyl cellulose, cationized cellulose, and sucrose fatty acid esters.

[0025] Examples of the synthetic polymer include carbomer (crosslinked polyacrylic acid), polyacrylic acid, sodium polyacrylate, acrylic acid / alkyl methacrylate copolymer, polyacrylamide, (sodium acrylate / sodium acryloyldimethyltaurate) copolymer, (hydroxyethyl acrylate / sodium acryloyldimethyltaurate) copolymer, (acrylamide / ammonium acrylate) copolymer, acrylic polymers such as acrylic acid polymers such as polyacrylate-13, polyvinylpyrrolidone, and cationized polyvinylpyrrolidone. Of these, polyvinylpyrrolidone and sucrose fatty acid esters are preferred.

[0026] [Method of producing the composition] The composition of the present invention can be produced by emulsifying the components (B), (C), and (D) in the presence of the component (A) and, if necessary, the water-soluble polymer, at a temperature equal to or higher than the melting point of the component (C). In the presence of the component (A) and the like, the components (B), (C), and (D) are emulsified under high-temperature conditions equal to or higher than the melting point of the component (C). As a result, as described above, when the component (C) (solid oil) solidifies, the component (B) is incorporated into the component (C), and phase separation occurs, with the component (B) (ultraviolet absorber) as the core and the component (C) (solid oil) as the shell, forming core-shell particles in which the ultraviolet absorber is encapsulated in the solid oil. In the composition of the present invention, component (B) is incorporated into component (C), preventing component (B) from coming into contact with the outside world. This prevents adverse effects on the user's experience, such as irritation and stickiness, and also makes it possible to obtain an ultraviolet absorber-encapsulating composition that is excellent in salt miscibility and storage stability.

[0027] The emulsification method may be a known method such as a dispersion method using mechanical shear force using a homogenizer, microfluidizer, ultrasonic emulsifier, high-pressure emulsifier (high-pressure homogenizer), Clearmix, double motion, etc., a membrane emulsification method, or a microchannel emulsification method. The temperature conditions during emulsification are not particularly limited as long as they are equal to or higher than the melting point of the solid oil used, but a temperature of about 70 to 95°C is preferred.

[0028] When the dispersion containing the essential components or, if desired, the optional components is subjected to high-pressure emulsification, the emulsion is subjected to high-pressure emulsification at an output of 1 to 100 MPa, preferably 2 to 70 MPa, and more preferably about 3 to 50 MPa. When ultrasonic emulsification is performed, the emulsion is subjected to high-pressure emulsification at an output of 10 to 200 W / h, 30 to 180 W / h, and more preferably 50 to 150 W / h, thereby further reducing the particle size of the droplets.

[0029] After emulsification, it is desirable to avoid rapid cooling and instead cool at a rate of 0.5 to 3°C / min in order to cause phase separation between the UV absorber and the solid oil. If rapid cooling is performed without sufficient stirring, particles may adhere to the part that comes into contact with the container, solidify, and become unstable. The average particle size of the core-shell particles thus obtained may be determined appropriately depending on the desired average particle size of the particles, but is usually about 0.2 to 20 μm, preferably about 0.4 to 10 μm. The average particle size of droplets within the above range can be obtained by appropriately setting the amounts of solid oil, ultraviolet absorber, and dispersion stabilizer used, the nonvolatile content, the emulsification temperature, and the like within the above ranges.

[0030] [Application] The composition of the present invention forms a core-shell structure with an oil-soluble UV absorber as the core and a solid oil as the shell, and therefore has excellent salt miscibility and storage stability, making it useful for UV protective cosmetics and the like. [Example]

[0031] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples as long as it does not depart from the gist of the invention. First, the evaluation methods and raw materials are shown below. In the examples, "parts" and "%" are by weight unless otherwise specified.

[0032] <Evaluation method> [Emulsification stability] The obtained suspension was filtered through a 150 mesh filter cloth, and the state of the suspension after being left to stand for 10 minutes was observed and evaluated according to the following criteria. ⊚: The suspension was filtered without clogging the filter cloth, and no layer separation such as floating oil was observed in the suspension. ◯: Some particles remained on the filter cloth, but no layer separation such as oil floating was observed in the suspension. ×: The suspension did not pass through the filter cloth at all, or oil floating in the suspension was observed.

[0033] [Average particle size measurement] Measurement was carried out using a laser diffraction / scattering particle size distribution analyzer LA-950V2 (manufactured by Horiba, Ltd.) to determine the volume-equivalent average particle size.

[0034] [Salt miscibility] Calcium chloride (CaCl 2、 Calcium chloride (Fujifilm Wako Pure Chemical Industries, Ltd.) was adjusted to a predetermined concentration in ion-exchanged water. 1 ml of the suspension was placed in an aluminum case measuring 75 mm (top diameter) x 35 mm (bottom diameter) x 20 mm (height), and approximately 0.1 ml of calcium chloride solution was added dropwise. The suspension was then mixed with a spatula, and the presence or absence of aggregates was confirmed. Evaluation was based on the following criteria. ◯: No agglomerates were formed. ×: Aggregates were generated.

[0035] [Storage stability] 20 g of the mixture was weighed into a 30 ml plastic container, and the viscosity was measured using a VISCOMATE VM-100A vibration viscometer (manufactured by SECONIK). After the measurement, the plastic container was placed in a 50°C oven, and after a certain period of time, it was removed and allowed to cool. The mixture was then slowly stirred with a spatula, and the viscosity was measured in the same manner. The temperature during the viscosity measurement was within the range of 24±2°C. After 4 weeks in a 50°C oven, the sample liquid was evaluated according to the following criteria: ⊚: The rate of change in viscosity after 4 weeks was less than 20%. Good: The viscosity change rate after 4 weeks was 20% or more and less than 60%. △: The viscosity change rate after 4 weeks was 60% or more, and the sample liquid had fluidity after 4 weeks. ×: After 4 weeks, the sample liquid had gelled and lost fluidity, making it impossible to measure the viscosity.

[0036] <Ingredients> [Component (A): Polyvinyl alcohol] Gohsenol EG-05...manufactured by Mitsubishi Chemical Corporation (hereinafter referred to as "EG05")

[0037] [Component (B): Oil-soluble UV absorber] Uvinal MC80...manufactured by BASF Ltd. (hereinafter referred to as "MC80")

[0038] [Component (C): Solid oil] Candelilla wax...Refined Candelilla wax TYPE: No. 1, manufactured by Nippon Wax Co., Ltd., melting point: 68-75°C, C20 or lower fatty acid content: 15.0% by weight Beeswax: SR BEESWAX-PA-JP, manufactured by Iwase Cosfa Co., Ltd., melting point: 62-65°C, fatty acid content of C20 or less: 95% by weight Carnauba wax: Carnauba Wax No. 3, manufactured by Kato Yoko Co., Ltd., melting point: 80-86°C, fatty acid content of C20 and below: 8.7% by weight Paraffin: Paraffin, manufactured by Kanto Chemical Co., Ltd., melting point: 60-62°C, does not contain fatty acids below C20 Microcrystalline wax...MULTIWAX W-445, manufactured by Shima Trading Co., Ltd., melting point: 60-85°C, contains no fatty acids below C20 Polycaprolactone...Capa2201, manufactured by Perstorp, melting point: 40-50°C, contains no fatty acids below C20 Stearic acid: Lunac S-98, manufactured by Kao Corporation, melting point 68-70°C Lauric acid...Lunac L-98, manufactured by Kao Corporation, melting point 42-44°C

[0039] [Optional ingredients] Polyvinylpyrrolidone: Polyvinylpyrrolidone K90, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., 2% aqueous solution (hereinafter referred to as "PVP") Cellulose nanofiber: Exilva F 01-L, manufactured by Borregaard, 2% aqueous solution (hereinafter referred to as "F01L") Sucrose laurate...L-1695, manufactured by Mitsubishi Chemical Corporation (hereinafter referred to as "L-1695")

[0040] [others] Anionic surfactant: Sodium lauryl sulfate, Emeral O, manufactured by Kao Corporation (hereinafter referred to as "sodium lauryl sulfate"). Oleic acid...Lunac OV, manufactured by Kao Corporation, melting point: 13.4°C, contains no fatty acids below C20

[0041] Example 1 A 10% aqueous solution of EG05 was prepared by heating and dissolving it in ion-exchanged water. 12 parts by weight of the 10% EG05 aqueous solution, 21 parts by weight of MC80, 17 parts by weight of candelilla wax, and 50 parts by weight of ion-exchanged water were weighed into a 300 ml stainless steel container and immersed in a 90°C hot bath for at least 30 minutes to dissolve the candelilla wax. After dissolving the candelilla wax, a suspension was prepared by emulsifying it using an ultrasonicator (Nippon Seiki Seisakusho, Ultra Generator Model US-300T, output approximately 100 W / h, 3 minutes). The suspension was then slowly cooled to room temperature while stirring. The resulting suspension was used for the measurements and evaluations described above. The results are shown in Table 1.

[0042] Example 2 A suspension was obtained in the same manner as in Example 1, except that the amount of 10% EG05 aqueous solution was changed to 6 parts by weight and the amount of ion-exchanged water was changed to 56 parts by weight. The obtained suspension was subjected to the above-mentioned measurements and evaluations. The results are shown in Table 1.

[0043] (Reference example 1) A suspension was obtained in the same manner as in Example 1, except that the 10% EG05 aqueous solution was replaced with 1.2 parts by weight of sodium lauryl sulfate and 60.8 parts by weight of ion-exchanged water. The obtained suspension was subjected to the above-mentioned measurements and evaluations. The results are shown in Table 1.

[0044] (Comparative Example 1) To 100 parts by weight of the suspension obtained in Reference Example, 12 parts by weight of a 10% EG05 aqueous solution was added, and the mixture was stirred and mixed at room temperature to obtain a suspension. The obtained suspension was used to carry out the above-mentioned measurements and evaluations. The results are shown in Table 1.

[0045] (Comparative Example 2) A suspension was obtained in the same manner as in Comparative Example 1, except that the amount of 10% EG05 aqueous solution was changed to 6 parts by weight. The obtained suspension was used to carry out the above-mentioned measurements and evaluations. The results are shown in Table 1.

[0046] [Table 1]

[0047] (result) In Example 1, by adopting the constitution of the present invention, no aggregates were generated when a 40% aqueous solution of calcium chloride (CaCl2) was added at 10%, demonstrating good salt miscibility. Furthermore, the viscosity change rate between the initial and two-week period was 5%, and the viscosity change rate between the initial and four-week period was 8%, indicating good storage stability due to the small viscosity change rate. On the other hand, in Comparative Example 1, polyvinyl alcohol (A) was not used during emulsification but was added after emulsification, so when a 40% aqueous solution of calcium chloride (CaCl2) was added at 10%, aggregates formed and salt miscibility deteriorated. The viscosity change rate between the initial and two-week period was about 18%, but the viscosity after four weeks was unmeasurable, indicating poor storage stability. In Comparative Example 2, even when a 10% aqueous solution of calcium chloride (CaCl) was added, aggregates formed, the initial viscosity was high, and the viscosity after 2 weeks was unmeasurable. In other words, both salt miscibility and storage stability were poor.

[0048] Examples 3 to 19 A suspension was obtained in the same manner as in Example 1, except that the blending amounts were as shown in Table 2. The obtained suspension was used to carry out the above-mentioned measurements and evaluations. The results are shown in Table 2.

[0049] (Comparative Example 3) A suspension was obtained in the same manner as in Example 1, except that a non-solid oil (oleic acid) was used instead of component (C). The obtained suspension was subjected to the above-mentioned measurements and evaluations. The results are shown in Table 2.

[0050] [Table 2]

[0051] (result) In Example 3, stearic acid was used in combination with a solid oil agent. Emulsion stability during production was improved, and when 10% of a 40% aqueous solution of calcium chloride (CaCl2) was added, no aggregates were formed, demonstrating good salt miscibility. Although the viscosity change rate between the initial and four-week period was 40%, there was no loss of fluidity, demonstrating good storage stability. In Example 4, beeswax, which contains a large amount of fatty acids, was used as the solid oil. The emulsion stability during production was improved, and when 10% of a 40% aqueous solution of calcium chloride (CaCl2) was added, no aggregates were formed, demonstrating good salt miscibility. Although the viscosity increased by 194% between the initial and four-week periods, there was no loss of fluidity.

[0052] In Example 5, paraffin was used as the solid oil agent, and stearic acid was also used. When 10% of a 40% aqueous solution of calcium chloride (CaCl2) was added, no aggregates were formed, demonstrating good salt miscibility. The viscosity change rate between the initial and four-week period was 49%, showing no loss of fluidity and good storage stability. In Example 6, microcrystalline wax was used as the solid oil agent. When 10% of a 40% aqueous solution of calcium chloride (CaCl2) was added, no aggregates were formed, demonstrating good salt miscibility. The viscosity change rate between the initial and 4 weeks was 53%, showing no loss of fluidity and good storage stability. In Example 7, the amount of PVA was increased compared to Example 1. Emulsion stability during production was improved, and when 10% of a 40% aqueous solution of calcium chloride (CaCl2) was added, no aggregates were formed, demonstrating good salt miscibility. The viscosity change rate between the initial and 4 weeks was -3%, and the small viscosity change rate indicated good storage stability.

[0053] In Example 8, half the amount of PVA was replaced with PVP compared to Example 1. When 10% of a 40% aqueous solution of calcium chloride (CaCl2) was added, no aggregates were generated, demonstrating good salt miscibility. The viscosity change rate between the initial and 4 weeks was -23%, showing no loss of fluidity and good storage stability. Example 9 is a mixture of Example 1 and Example 2, further adding cellulose nanofibers in an amount 1 / 6 the amount of PVA. When a 40% aqueous solution of calcium chloride (CaCl2) was added at 10%, no aggregates were formed, demonstrating good salt miscibility. The viscosity change rate between the initial and 4 weeks was 38%, showing no loss of fluidity and good storage stability. In Example 10, polycaprolactone was used as the solid oil agent. A suspension with good emulsion stability was obtained during production, and when 10% of a 40% aqueous solution of calcium chloride (CaCl2) was added, no aggregates were formed, demonstrating good salt miscibility. The viscosity change rate between the initial and two-week period was -42%, indicating a tendency for viscosity to decrease. However, the viscosity change rate between the initial and four-week period was -2%, indicating no loss of fluidity and good storage stability.

[0054] In Example 11, carnauba wax with a high melting point was used as the solid oil. When 10% of a 40% aqueous solution of calcium chloride (CaCl2) was added, no aggregates were formed, demonstrating good salt miscibility. The viscosity change rate between the initial and four weeks was -17%, and the small viscosity change rate indicated good storage stability. In Example 12, stearic acid was used in combination with a solid oil agent. Emulsion stability during production was improved, and when 10% of a 40% aqueous solution of calcium chloride (CaCl2) was added, no aggregates were formed, demonstrating good salt miscibility. Although the viscosity change rate between the initial and four-week period was -55%, there was no loss of fluidity, demonstrating good storage stability. In Example 13, a larger amount of stearic acid was used in combination with the solid oil agent than in Example 12. The emulsion stability during production was improved, and when 10% of a 40% aqueous solution of calcium chloride (CaCl2) was added, no aggregates were formed, demonstrating good salt miscibility. Although the viscosity change rate between the initial stage and after 4 weeks was -36%, there was no loss of fluidity, indicating good storage stability. did.

[0055] In Example 14, a larger amount of stearic acid was used in combination with the solid oil than in Example 13. The emulsion stability during production was improved, and when 10% of a 40% aqueous solution of calcium chloride (CaCl2) was added, no aggregates were formed, demonstrating good salt miscibility. Although the viscosity change rate between the initial and four-week period was -42%, there was no loss of fluidity, demonstrating good storage stability. In Example 15, the proportion of UV absorber was reduced and the proportion of solid oil was increased. The increased proportion of solid oil increased the viscosity during emulsification, resulting in an average particle size of 44.78 μm. However, when 10% of a 40% aqueous solution of calcium chloride (CaCl2) was added, no aggregates were formed, demonstrating good salt miscibility. Although the viscosity change rate between the initial and four-week period was -66%, the fluidity was not impaired, demonstrating good storage stability. In Example 16, the proportion of UV absorber was increased and the proportion of solid oil agent was decreased. The decreased proportion of solid oil agent resulted in a decrease in viscosity during emulsification, resulting in an average particle size of 1.79 μm. When 10% of a 40% aqueous solution of calcium chloride (CaCl2) was added, no aggregates were formed, demonstrating good salt miscibility. The viscosity change rate between the initial and 4-week period was -11%, and the small viscosity change rate indicated good storage stability.

[0056] In Example 17, the 10% PVA aqueous solution of Example 6 was reduced to 25%, and the active ingredient was replaced with sucrose laurate. The emulsion stability during production was excellent, and when a 40% aqueous solution of calcium chloride (CaCl2) was added at 10%, no aggregates formed, demonstrating good salt miscibility. Although the viscosity increased by approximately 4000% between the initial and two-week period, and approximately 8000% between the initial and four-week period, the fluidity was not impaired. In Example 18, part of the microcrystalline wax in Example 17 was replaced with lauric acid. The emulsion stability during production was excellent, and when a 40% aqueous solution of calcium chloride (CaCl2) was added at 10%, no aggregates formed, demonstrating good salt miscibility. The viscosity change rate between the initial and two-week period was -15%, and the viscosity change rate between the initial and four-week period was 5%, demonstrating good storage stability. Example 19 is the same as Example 18, except that a portion of the microcrystalline wax was replaced with a larger amount of lauric acid. It exhibited emulsion stability during production, and when a 40% aqueous solution of calcium chloride (CaCl2) was added at 10%, no aggregates formed, demonstrating good salt miscibility. The viscosity change rate between the initial and two-week period was -10%, and the viscosity change rate between the initial and four-week period was -19%, demonstrating good storage stability.

[0057] On the other hand, in Comparative Example 3, oleic acid, which is not a solid oil agent, was used. The emulsion was oily and had insufficient emulsion stability, and it was found that the UV absorber was not sufficiently supported.

Claims

1. A method for producing a composition comprising polyvinyl alcohol as component (A), an oil-soluble ultraviolet absorber as component (B), a solid oil as component (C), and water as component (D), the method comprising emulsifying components (B), (C), and (D) in the presence of component (A) at a temperature equal to or higher than the melting point of component (C), the content of the component (A) is 0.1% by weight or more and 10% by weight or less of the composition, the content of the component (B) is 16% by weight or more and 40% by weight or less of the composition, the component (B) is a liquid at 20°C, The component (C) is contained in an amount of 3% by weight or more based on the composition, the component (B) and the component (C) form particles, and the content of the component (B) relative to the total weight of the particles is 20% by weight or more and 75% by weight or less; the component (C) is an oil agent that is solid at 25°C and is selected from the group consisting of vegetable waxes, animal waxes, petroleum waxes, fatty acids, and combinations thereof, and the total amount of fatty acids having 20 or less carbon atoms in the component (C) is 3% by weight or more of the component (C); Method for producing the composition.

2. 2. The method for producing a composition according to claim 1, wherein the composition is used in a UV protective cosmetic.

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