Particles, cosmetics, and methods for producing particles

Abstract

To provide particles that can selectively adsorb free fatty acids and offer excellent makeup longevity. [Solution] Particles comprising a biodegradable resin and a metal oxide, wherein the ratio of oleic acid absorption to triglyceride absorption in the particles is 1.5 or more.

Description

[Technical Field]

[0001] This invention relates to particles, cosmetics, and methods for producing particles. [Background technology]

[0002] Free fatty acids, which are components derived from sebum secreted by the human body, are known to cause body odor and other unpleasant smells, as well as shine over time in makeup. From the perspective of improving the longevity of makeup, materials and methods for removing free fatty acids from the skin surface are being investigated.

[0003] To date, methods have been employed such as incorporating oil-absorbing powders, such as silica gel, into cosmetics to adsorb sebum components, and replacing powders used in makeup cosmetics with highly oil-repellent fluorine-treated powders. Furthermore, to improve the longevity of makeup, film-forming polymers such as acrylic-silicone graft polymers are known.

[0004] Furthermore, zinc oxide coated materials, in which an amorphous (non-crystalline) zinc oxide is coated onto a substrate, have been proposed, and powders with good spreadability without impairing fatty acid solidification ability and topical skin preparations using the same have been reported (see, for example, Patent Document 1). In addition, interlayer metal inclusion compounds that selectively adsorb only free fatty acids or compounds in which one or more oxides and / or their hydroxides are encapsulated between layers of clay minerals have been reported (see, for example, Patent Document 2). Moreover, composite powders having a hydroxyapatite layer on the particle surface of the substrate and a zinc oxide layer on the surface thereof have been proposed (see, for example, Patent Document 3). [Overview of the project] [Problems that the invention aims to solve]

[0005] The present invention aims to provide particles that can selectively adsorb free fatty acids and have excellent makeup retention properties. [Means for solving the problem]

[0006] The particles of this embodiment, as a means to solve the aforementioned problems, are particles comprising a biodegradable resin and a metal oxide, wherein the ratio of oleic acid absorption to triglyceride absorption in the particles is 1.5 or more. [Effects of the Invention]

[0007] According to the present invention, particles can selectively adsorb free fatty acids and provide excellent makeup retention. [Modes for carrying out the invention]

[0008] (particle) The particles of this embodiment include a biodegradable resin and a metal oxide, and further include other materials as needed. The oleic acid absorption / triglyceride absorption ratio in the particles is 1.5 or higher. The particles of this embodiment can selectively adsorb free fatty acids and have excellent makeup retention properties, making them suitable for use in sebum control particles, cosmetics, and other applications.

[0009] The particles of this embodiment are based on the identification of the problems of the prior art described later.

[0010] In other words, using oil-absorbing powders such as silica gel in conventional technology results in the adsorption of oily components other than free fatty acids, such as triglycerides, which are important for skin emollients. Therefore, if the powder is formulated to sufficiently adsorb free fatty acids, a deficiency of emollient components may occur, making it difficult to formulate in sufficient quantities. Furthermore, when such powders adsorb oily components, they exhibit a glossy appearance due to wetting with the oily components, resulting in a shiny finish to makeup and a messy look.

[0011] Conventional fluorine-treated powders, while not wetting with sebum components, have a problem in that their strong oil-repellent properties cause the powder to slide over sebum, resulting in uneven application. In other words, there was a need for a cosmetic material that selectively adsorbs only free fatty acids.

[0012] Conventional acrylic-silicone graft polymers can be produced by radical polymerization of a dimethylpolysiloxane compound having radical polymerizability at the molecular chain ends and a radical polymerization monomer mainly composed of acrylate or methacrylate. Acrylic-silicone graft polymers form cosmetic films with excellent water and oil resistance and have been put into practical use in non-aqueous foundations. However, cosmetics using film-forming polymers such as acrylic-silicone graft polymers have lingering challenges from a skin physiological perspective, considering healthy biological reactions on the skin surface, due to their occlusive properties. Furthermore, powder products that cannot effectively utilize film-forming ability have the problem of being difficult to improve the longevity of makeup.

[0013] In the zinc oxide coated material described in Patent Document 1, the amount of oleic acid adsorbed by the zinc oxide coated material is approximately the same as that of ordinary porous silica, and it is not particularly superior in adsorbing free fatty acids. Furthermore, the amount of artificial sebum adsorbed is lower than that of porous silica beads, and the fatty acid solidification time is approximately 30 minutes, which presents a problem as it is particularly difficult to use for oily skin or extremely oily skin.

[0014] The intercalated metal inclusion compound described in Patent Document 2 uses a water-swellable clay mineral and is manufactured by a reaction in a sol state. As can be seen from the description of the examples, the reaction is carried out in a dilute solution. For this reason, this method has a high production cost per batch and is economically very disadvantageous. Furthermore, because the reaction is carried out in a sol state, the washing process in the usual deliquidation, washing, and drying steps is extremely slow, resulting in a great deal of wasted time. In addition, the resulting product undergoes very strong aggregation, failing to achieve the expected performance, making freeze-drying a necessary condition and resulting in very high costs. Moreover, although AL pillars are formed between the layers of clay mineral, the content of the intercalated oxide or hydroxide varies greatly depending on the lot variation of the clay mineral and the state of pillar formation, making it difficult to consistently obtain stable quality.

[0015] In the composite powder having a hydroxyapatite layer on the particle surface of the substrate described in Patent Document 3 and having a zinc oxide layer on its surface, it has been reported that it has excellent sebum adsorption properties, antibacterial effects, and the property of adsorbing body odor components. This composite powder is currently used as a cosmetic having sebum adsorption properties. However, for example, there is an expectation to further improve the properties (cosmetic effects) as a cosmetic such as improvement of makeup retention, suppression of the "shine" phenomenon, and improvement of the feeling of use, as well as the adsorption properties of unsaturated fatty acids and sebum.

[0016] As a result of intensive research to find a suitable material for a cosmetic that selectively adsorbs free fatty acids, the present inventors have found that particles containing a biodegradable resin and a metal oxide, by making the value of the absorption amount of oleic acid / absorption amount of triglyceride in the particles 1.5 or more, it is possible to selectively adsorb free fatty acids and provide particles excellent in makeup retention.

[0017] [Absorption amount of oleic acid / absorption amount of triglyceride in the particles] The value of the absorption amount of oleic acid / absorption amount of triglyceride in the particles is 1.5 or more, preferably 1.5 or more and 7.0 or less, and more preferably 2.0 or more and 7.0 or less. When the value is 1.5 or more, free fatty acids are selectively adsorbed and the makeup retention can be improved. When the value is larger, it is more preferable that free fatty acids can be selectively adsorbed.

[0018] Here, oleic acid is a representative example of free fatty acids. As the triglyceride, a neutral fat in which three molecules of oleic acid are ester-bonded to glycerin is used, and the value contributes as an index indicating the selective absorbability of free fatty acids.

[0019] The absorption amount of oleic acid in the particles is the value obtained by dividing the absorption amount of oleic acid by the particles [g] by the amount of the particles [g]. The absorption amount of triglyceride in the particles is the value obtained by dividing the absorption amount of triglyceride by the particles [g] by the amount of the particles [g]. The absorption amount of oleic acid / triglyceride absorption amount in the particles is the value obtained by dividing the "absorption amount of oleic acid in the particles" by the "absorption amount of triglyceride absorption amount in the particles".

[0020] The maximum absorption amount of oleic acid or triglyceride in the particles can be measured by the following procedure.

[0021] Specifically, a predetermined amount of oleic acid or triglyceride (hereinafter referred to as "each component") is added to a certain amount of particles and mixed with a spatula for 15 minutes. Then, the components that have not been absorbed by the particles are removed by pressing an oil-absorbing paper (for example, high-grade oil-absorbing paper 90 mm × 90 mm, manufactured by Kai Corporation). And, the total mass of the components absorbed by the particles and the particles that cannot be removed with the oil-absorbing paper is measured, and by subtracting the mass of the particles, the mass of oleic acid or triglyceride absorbed by the particles can be calculated. In addition, in order to ensure that the absorption amount is saturated, the addition amount of each component is set so that the mass of each component removed with the oil-absorbing paper exceeds 5% by mass of the particles.

[0022] [Relative Span Factor (R.S.F)] "Relative Span Factor (R.S.F)" is (D 90 - D 10 ) / D 50 and is defined as an index representing the narrowness of the particle size distribution. D 90 represents the cumulative 90% by number from the small particle side of the cumulative particle size distribution, D 50 represents the cumulative 50% by number from the small particle side of the cumulative particle size distribution, D 10 represents the cumulative 10% by number from the small particle side of the cumulative particle size distribution. The smaller the value of (R.S.F), the narrower the particle size distribution.

[0023] Methods for measuring RSF include, for example, using a concentrated particle analyzer using dynamic light scattering ("FPAR-1000", manufactured by Otsuka Electronics Co., Ltd.) or a particle size distribution analyzer using laser diffraction / scattering ("LA-960", manufactured by Horiba, Ltd.).

[0024] Other indicators that show the narrowness of the particle size distribution include, for example, the volume-average particle size (Dv) / number-average particle size (Dn). The volume-average particle size (Dv) / number-average particle size (Dn) is the value obtained by dividing the volume-average particle size (Dv) by the number-average particle size (Dn), and a smaller value indicates a narrower particle size distribution. The volume-average particle size (Dv) / number-average particle size (Dn) of the resin particles of the present invention is preferably 1.00 or more and 1.50 or less, and more preferably 1.00 or more and 1.20 or less.

[0025] Methods for measuring volume-average particle size (Dv) and number-average particle size (Dn) include, for example, using a laser diffraction / scattering particle size distribution analyzer (Microtrac MT3000II, manufactured by Microtrac-Bell Co., Ltd.) or a particle size distribution analyzer using the laser diffraction / scattering method ("LA-960," manufactured by Horiba, Ltd.).

[0026] [Volume-average particle size] The volume-average particle size (Dv) of the aforementioned particles is 3 μm or more and 50 μm or less. If the particles are larger than 50 μm, the contact area of ​​free fatty acids relative to the volume of the particles becomes smaller, resulting in a decrease in the absorption of free fatty acids. On the other hand, if the volume-average particle size (Dv) is 3 μm or more and 50 μm or less, the absorption of free fatty acids can be ensured, and the oleic acid absorption / triglyceride absorption value can be set to 1.5 or more. From the viewpoint of tactile feel and spreadability on the skin, the volume-average particle size (Dv) is preferably 3 μm or more and 20 μm or less.

[0027] The preferred mass ratio (B / M) of biodegradable resin (B) to metal oxide (M) in the aforementioned particles is 0.5 / 9.5 or more and 8 / 2 or less.

[0028] <Biodegradable resin> The biodegradable resin is not particularly limited as long as it is a biodegradable resin, but it is preferably at least one resin selected from the group consisting of polyester resins, polyamide resins, and cellulose resins.

[0029] Examples of biodegradable polyester resins include polylactic acid; poly-ε-caprolactone; succinate polymers such as polyethylene succinate, polybutylene succinate, and polybutylene succinate adipate; polybutylene adipate terephthalate; polyhydroxyalkanoates such as polyhydroxypropionate, polyhydroxybutyrate, polyhydroxyparylate, and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate); and polyglycolic acid.

[0030] Examples of biodegradable polyamide resins include nylon 4.

[0031] Examples of biodegradable cellulosic resins include hydroxypropyl cellulose, hydroxypropyl methylcellulose, and hypromellose acetate succinate.

[0032] These resins may be used individually or in combination of two or more types.

[0033] -Polylactic acid- There are no particular restrictions on the weight-average molecular weight Mw of polylactic acid, and it can be appropriately selected depending on the purpose, but it is preferably 5,000 to 100,000, more preferably 10,000 to 70,000, and even more preferably 10,000 to 60,000.

[0034] -Polyglycolic acid- There are no particular restrictions on the polyglycolic acid, and it can be appropriately selected depending on the purpose. Examples include lactic acid-glycolic acid copolymers, which are copolymers having structural units derived from lactic acid and structural units derived from glycolic acid; glycolic acid-caprolactone copolymers, which are copolymers having structural units derived from glycolic acid and structural units derived from caprolactone; and glycolic acid-trimethylene carbonate copolymers, which are copolymers having structural units derived from glycolic acid and structural units derived from trimethylene carbonate. These may be used individually or in combination of two or more. Among these, lactic acid-glycolic acid copolymers are preferred because they have high biocompatibility, can release physiologically active substances gradually, and can store physiologically active substances for a long period of time.

[0035] Examples of lactic acid-glycolic acid copolymers include PURASORB PDLG5010, PURASORB PDLG7510, PURASORB PDLG7507, PURASORB PDLG5002A, PURASORB PDLG5002, PURASORB PDLG7502A (manufactured by Corbion); RG502, RG502H, RG503, RG503H, RG504, RG504H (manufactured by Sigma-Aldrich).

[0036] There are no particular restrictions on the weight-average molecular weight of the lactic acid-glycolic acid copolymer, and it can be appropriately selected depending on the purpose, but it is preferably 2,000 to 250,000, more preferably 2,000 to 100,000, and particularly preferably 40,000 to 50,000.

[0037] In a lactic acid-glycolic acid copolymer, there are no particular restrictions on the molar ratio (L / G) of constituent units derived from lactic acid (L) to constituent units derived from glycolic acid (G), and it can be appropriately selected depending on the purpose. However, a ratio of 1 / 99 to 99 / 1 is preferred, 25 / 75 to 99 / 1 is more preferred, 30 / 70 to 90 / 10 is even more preferred, and 50 / 50 to 85 / 15 is particularly preferred.

[0038] -Polyhydroxyalkanoate- There are no particular restrictions on the polyhydroxyalkanoate, and it can be appropriately selected depending on the purpose, but it is preferable that it be a poly(3-hydroxyalkanoate) polymer or copolymer consisting of repeating units represented by the following general formula (1).

[0039] [-CH(R)-CH2CO-O-] General formula (1) However, in general formula (1), R is -C n H 2n+1 This is an alkyl group represented by , where n is an integer from 1 to 15.

[0040] Examples of poly(3-hydroxyalkanoate) polymers or copolymers consisting of repeating units represented by general formula (1) include polymers consisting of one type of repeating unit selected from the group consisting of 3-hydroxypropionate, 3-hydroxybutyrate, 3-hydroxyvalerate, 3-hydroxyhexanoate, 3-hydroxyheptanoate, 3-hydroxyoctanoate, 3-hydroxynonanoate, 3-hydroxydecanoate, 3-hydroxytetradecanoate, 3-hydroxyhexadecanoate, and 3-hydroxyoctadecanoate, or copolymers consisting of two or more types of repeating units. Specifically, examples include homopolymers of the 3-hydroxyalkanoate, copolymers consisting of two or more 3-hydroxyalkanoates with different n values, and mixtures obtained by blending two or more selected from the group consisting of the homopolymer and the copolymer. Among these, homopolymers, copolymers, and mixtures thereof composed of the group consisting of n=1 3-hydroxybutyrate repeating units, n=2 3-hydroxyvalerate repeating units, n=3 3-hydroxyhexanoate repeating units, n=5 3-hydroxyoctanoate repeating units, and n=15 3-hydroxyoctadecanoate repeating units are preferred, and copolymers consisting of a 3-hydroxybutyrate repeating unit and at least one repeating unit selected from the group consisting of 3-hydroxyvalerate, 3-hydroxyhexanoate, and 3-hydroxyoctanoate are more preferred.

[0041] When using a copolymer of 3-hydroxybutyrate and 3-hydroxyhexanoate, there are no particular restrictions on the ratio of 3-hydroxybutyrate to 3-hydroxyhexanoate, and it can be appropriately selected according to the purpose. However, in order to suppress the increase in viscosity of the particle composition liquid due to a higher ratio of 3-hydroxybutyrate and to ensure good droplet discharge in the droplet discharge process, the molar ratio of 3-hydroxybutyrate (HB) to 3-hydroxyhexanoate (HH) (HB / HH) is preferably 80 / 20 or more and 94 / 6 or less, and more preferably 80 / 20 or more and 90 / 10 or less.

[0042] There are no particular restrictions on the weight-average molecular weight Mw of the polyhydroxyalkanoate, and it can be appropriately selected depending on the purpose. However, a value of 2,000 to 1,000,000 is preferred, and a value of 2,000 to 600,000 is more preferred, in order to suppress the increase in viscosity of the particle composition liquid due to a larger molecular weight and to ensure good droplet discharge in the droplet discharge process.

[0043] <Metal oxide particles> The aforementioned metal oxide is not particularly limited and can be appropriately selected depending on the purpose. Examples include single-component powders such as silica, alumina, zinc oxide, titanium oxide, and cerium oxide; bismuth oxychloride and barium sulfate. These may be used individually, in combination of two or more, or in the form of a metal oxide composite.

[0044] Examples of the metal oxide composites include multilayer composites such as silica-titanium oxide, silica-zinc oxide, silica-titanium oxide-silica, silica-cerium oxide-silica, and silica-zinc oxide-silica; pearl pigments such as titanium mica, colored titanium mica, titanium oxide-barium sulfate, titanium oxide-talc, zinc oxide-mica, zinc oxide-talc, and bismuth oxychloride-mica; and pearl pigments whose surfaces are treated with aluminum hydroxide, aluminum oxide, magnesium hydroxide, magnesium oxide, silica, or barium sulfate; and hard capsules such as titanium oxide-encapsulated acrylic / methacrylic resin (PMMA), zinc oxide-encapsulated PMMA, and cerium oxide-encapsulated PMMA.

[0045] Among these, zinc oxide is preferred because of its good reactivity with free fatty acids.

[0046] The shape of the metal oxide is preferably particle-shaped in that it has a large contact area with free fatty acids. The volume-average particle size (Dv) of the metal oxide is preferably 10 nm to 200 nm, and more preferably 10 nm to 100 nm.

[0047] <Other ingredients> The aforementioned particles may be combined with other components such as physiologically active substances and dispersion stabilizers as needed, and can be used as functional particles according to various applications. Furthermore, as described later, the aforementioned particles can be used as cosmetic particles by being used in combination with cosmetic components.

[0048] There are no particular restrictions on the functional particles, and they can be appropriately selected according to the purpose. Examples include immediate-release particles, sustained-release particles, pH-dependent release particles, pH-independent release particles, enteric-coated particles, release-controlled coated particles, and nanocrystal-containing particles.

[0049] <<Physiologically active substances>> There are no particular restrictions on the physiologically active substances, and they can be appropriately selected according to the purpose. For example, alcohols, fatty alcohols and polyols, aldehydes, alkanolamines, alkoxylated alcohols (e.g., polyethylene glycol derivatives of alcohols, fatty alcohols, etc.), alkoxylated amides, alkoxylated amines, alkoxylated carboxylic acids, amides containing salts (e.g., ceramides, etc.), amines, amino acids containing salts and alkyl-substituted derivatives, esters, alkyl-substituted and acyl derivatives, polyacrylic acids, acrylamide copolymers, adipic acid copolymers, aminosilicones, biological polymers and their derivatives, butylene copolymers, carbohydrates (e.g., polysaccharides, chitosan, and their derivatives, etc.), carboxylic acids, carbomers, esters, etc. Examples include ethers and polymer ethers (e.g., PEG derivatives, PPG derivatives, etc.), glyceryl esters and their derivatives, halogen compounds, heterocyclic compounds containing salts, hydrophilic colloids and derivatives containing salts and rubber (e.g., cellulose derivatives, gelatin, xanthan gum, natural rubber, etc.), imidazolines, inorganic substances (clay, TiO2, ZnO, etc.), ketones (e.g., camphor, etc.), isethionates, lanolin and its derivatives, organic salts, phenols containing salts (e.g., parabens, etc.), phosphorus compounds (e.g., phosphoric acid derivatives, etc.), polyacrylates and acrylate copolymers, protein and enzyme derivatives (e.g., collagen, etc.), synthetic polymers containing salts, siloxanes and silanes, sorbitan derivatives, sterols, sulfonic acids and their derivatives, waxes, and the like. These may be used individually or in combination of two or more.

[0050] <<Dispersion stabilizer>> There are no particular restrictions on the dispersion stabilizer, and it can be appropriately selected depending on the purpose. Examples include alkaline earth metal salts; poorly water-soluble inorganic compounds such as calcium carbonate and calcium phosphate. Among these, calcium carbonate surface-treated with a silane coupling agent is preferred because it has high compatibility with biodegradable resins and excellent dispersion stability. The content of alkaline earth metal components in the particles is preferably less than 10 ppm by mass relative to the total mass of the particles, from the viewpoint of suppressing particle aggregation caused by adsorption of moisture from the atmosphere onto the dispersion stabilizer.

[0051] One possible method for measuring the amount of alkaline earth metal components contained in particles is as follows: 1.0 g of the particles to be measured is accurately weighed into a crucible and heated in an electric furnace at 450°C for 3 hours to incinerate the particles. The incinerated particles are dissolved in 2 mL of concentrated hydrochloric acid, and the volume is adjusted to 50 mL with ultrapure water to prepare the sample. The amount of alkaline earth metal components can then be measured using a multi-type ICP emission spectrometer ("ICPE-9000", manufactured by Shimadzu Corporation).

[0052] (Cosmetics) The cosmetic composition of this embodiment contains the particles of this embodiment and, if necessary, also contains other components.

[0053] <Other ingredients> Other ingredients can be appropriately selected from known cosmetic ingredients, such as physiologically active substances, dispersion stabilizers, pigments, oily bases, emulsifiers, preservatives, and fragrances.

[0054] For example, a foundation can be made by mixing the particles of this embodiment with pigments, oily bases, emulsifiers, preservatives, fragrances, etc.

[0055] There are no particular restrictions on the pigments used; known cosmetic components can be appropriately selected depending on the purpose, such as inorganic pigments, organic pigments, pearl pigments, and metal powder pigments.

[0056] There are no particular restrictions on the oily base, and known cosmetic components can be appropriately selected depending on the purpose. Examples include ester oils, hydrocarbon oils, silicone oils, higher fatty acids, alkyl glyceryl ethers, liquid oils, solid oils, semi-solid oils, and oil-soluble agents.

[0057] There are no particular restrictions on the emulsifier, and any known cosmetic ingredient can be appropriately selected depending on the purpose. Examples include anionic surfactants, cationic surfactants, nonionic surfactants, and amphoteric surfactants.

[0058] [Application] The particles of this embodiment are useful as raw materials for cosmetics. Specific examples of cosmetics include foundation, blush, eyeshadow, cleansing agents, facial cleansing creams, sunscreen creams, antiperspirants, pre-shave lotions, aftershave lotions, face powder, toners, face masks, massage creams, lotions, moisturizing creams, serums, lipsticks, eyeliners, nail polish, soaps, bath additives, shampoos, conditioners, hair treatments, sun oils, bleaching creams, hair removal creams, insect repellent lotions, insect repellent sprays, hair liquids, pomades, hair colorants, colognes, shampoos, conditioners, and hair styling products. Among these, foundation, blush, eyeshadow, cleansing agents, facial cleansing creams, sunscreen creams, antiperspirants, and pre-shave lotions are preferred because they can selectively adsorb free fatty acids derived from sebum secreted from the skin, contributing significantly to improved makeup longevity.

[0059] (Method for manufacturing particles, and apparatus for manufacturing particles) The particle manufacturing method of this embodiment includes a step of discharging a composition containing a biodegradable resin, a metal oxide, and a solvent as droplets into a gas (droplet discharging step), and a step of removing the solvent from the droplets to granulate the particles (granulation step), and further includes other steps as necessary.

[0060] The particle manufacturing apparatus of this embodiment includes a droplet dispensing means for dispensing a composition containing a biodegradable resin, a metal oxide, and a solvent as droplets into a gas, and a granulation means for removing the solvent from the droplets to granulate particles, and may include other means as needed.

[0061] According to the particle manufacturing method and particle manufacturing apparatus of this embodiment, the particles of this embodiment can be suitably manufactured, and particles that can selectively adsorb free fatty acids and have excellent cosmetic retention properties can be suitably manufactured.

[0062] <Droplet ejection process and droplet ejection means> The aforementioned droplet dispensing step is a step of dispensing a composition containing a biodegradable resin, a metal oxide, and a solvent as droplets into a gas, and can be suitably carried out by a droplet dispensing means.

[0063] The aforementioned droplet dispensing means is a means for dispensing a composition containing a biodegradable resin, a metal oxide, and a solvent as droplets into a gas, and examples include a nozzle equipped with a composition container. Preferably, the droplet dispensing means forms droplets by bringing the composition into contact with the gas and atomizing it.

[0064] The composition container is a container that holds a composition containing a metal oxide and a solvent, and may have stirring means such as stirring fins or a magnetic stirrer.

[0065] The composition container may be flexible or not. The material of the composition container is not particularly limited and can be appropriately selected depending on the purpose; for example, it may be made of resin or metal. The structure of the composition container is not particularly limited and can be appropriately selected depending on the purpose; for example, it may be a sealed structure or an open structure.

[0066] The means for connecting the nozzle and the composition container are not particularly limited, as long as the composition can be supplied from the composition container to the nozzle, and can be appropriately selected depending on the purpose. Examples include pipes, tubes, etc.

[0067] -Composition- The composition contains a biodegradable resin, a metal oxide, and a solvent, and further contains other components as needed.

[0068] The biodegradable resin and metal oxide in the above composition, as well as the mass ratio (B / M) of the biodegradable resin (B) to the metal oxide (M), can be appropriately selected from the matters described for the particles of this embodiment. The mass ratio (B / M) is preferably 0.5 / 9.5 or more and 8 / 2 or less.

[0069] In one embodiment, it is preferable that the composition and solvent are substantially free of surfactants. This is particularly preferable when the particles produced are used in applications such as pharmaceutical compositions, functional foods, and functional cosmetics, as it improves safety. Here, substantially free of surfactants means, for example, that the amount of surfactant in the composition and solvent is below the detection limit that cannot be detected by liquid chromatography, or that the composition and solvent do not contain surfactants.

[0070] --solvent-- Examples of solvents include water, aliphatic halogenated hydrocarbons (e.g., dichloromethane, dichloroethane, chloroform, etc.), alcohols (e.g., methanol, ethanol, propanol, 3-methoxy-3-methyl-1-butanol, 2,2,2-trifluoroethanol, etc.), ketones (e.g., acetone, methyl ethyl ketone, etc.), ethers (e.g., diethyl ether, dibutyl ether, 1,4-dioxane, etc.), aliphatic hydrocarbons (e.g., n-hexane, cyclohexane, n-heptane, etc.), aromatic hydrocarbons (e.g., benzene, toluene, xylene, etc.), organic acids (e.g., acetic acid, propionic acid, etc.), esters (e.g., ethyl acetate, 3-methoxy-3-methyl-1-butyl acetate, etc.), amides (e.g., dimethylformamide, dimethylacetamide, etc.), or mixed solvents thereof. These may be used individually or in combination of two or more. Among these, ketones, ethers, alcohols, or mixed solvents thereof are preferred in terms of solubility, and acetone, 1,3-dioxolane, ethanol, 2-propanol, or mixed solvents thereof are more preferred.

[0071] Furthermore, in one embodiment, by using a mixed solvent made by adding a poor solvent to a good solvent for the biodegradable resin, it is possible to change the particle shape of the resulting particles from spherical to porous. From the viewpoint of increasing the contact area between the particles and free fatty acids, it is preferable that the solvent is a mixture of a good solvent and a poor solvent for the biodegradable resin. The mass ratio of the good solvent to the poor solvent (good solvent / poor solvent) is preferably 40 / 60 or more and 90 / 10 or less, and more preferably 50 / 50 or more and 90 / 10 or less.

[0072] The solvent content is preferably 70% to 99.5% by mass, and more preferably 80% to 99% by mass, relative to the total mass of the composition. When the content is 70% to 99.5% by mass, production stability is improved in terms of the solubility of the particle material and the liquid viscosity.

[0073] In one embodiment, it is possible to utilize the biodegradable resin as an emulsion without using a good solvent for the biodegradable resin. By mixing a dispersion in which nanoparticles of the biodegradable resin are dispersed in water or a poor solvent for the biodegradable resin with a metal oxide, a desired composition can be obtained. Note that the particle size of the nanoparticles of the biodegradable resin is preferably 10 nm or more and 800 nm or less.

[0074] There is no particular limitation on the viscosity of the composition, and it can be appropriately selected according to the purpose. However, it is preferably 0.5 mPa·s or more and 15.0 mPa·s or less, and more preferably 0.5 mPa·s or more and 10.0 mPa·s or less. When the viscosity of the composition is 0.5 mPa·s or more and 15.0 mPa·s or less, suitable ejection can be performed in the above-described means for ejecting droplets.

[0075] Note that the viscosity can be measured, for example, using a viscoelasticity measuring device (device name: MCR rheometer, manufactured by Anton Paar) under the conditions of 25°C and a shear rate of 10 s. -1 It can be measured under the conditions of.

[0076] There is no particular limitation on the surface tension of the composition, and it can be appropriately selected according to the purpose. However, it is preferably 10 mN / m or more and 60 mN / m or less, and more preferably 20 mN / m or more and 50 mN / m or less. When the surface tension of the composition is 0.5 mPa·s or more and 15.0 mPa·s or less, suitable ejection can be performed in the above-described means for ejecting droplets.

[0077] Note that the surface tension can be measured, for example, using a handy surface tension meter (device name: PocketDyne, manufactured by KRUSS) by the maximum bubble pressure method under the conditions of 25°C and a lifetime of 1,000 ms.

[0078] <Granulation step, and granulation means> The granulation step is a step of removing the solvent from the droplets to granulate the particles, and it can be preferably carried out by granulation means.

[0079] The granulation means is a means for removing the solvent from a droplet to granulate particles, and examples include a component that forms a space for vaporizing the solvent from the droplet.

[0080] Furthermore, the granulation process is preferably carried out in a gaseous environment, specifically while the droplets ejected into the gas during the droplet ejection process are in flight through the gas.

[0081] Methods for removing the solvent from a droplet include, for example, adding a stream of dry air to vaporize the solvent, creating a reduced-pressure atmosphere using a vacuum device, heating, applying a chemical reaction to remove the solvent, or a combination of these methods.

[0082] Chemical substances that promote the drying of droplets may be mixed into the drying airflow. The state of the drying airflow is not limited and may be laminar, swirling, or turbulent. There are no particular restrictions on the type of gas that constitutes the drying airflow and can be appropriately selected according to the purpose; air may be used, or non-flammable gases such as nitrogen may be used. Furthermore, it is preferable to appropriately adjust the temperature, vapor pressure, and type of gas used for drying.

[0083] If the collected particles remain in a solid state, the solvent does not need to be completely vaporized, and an additional drying step may be added in a separate process after collection. Furthermore, if the amount of residual solvent in the obtained particles is large, it is preferable to perform secondary drying as needed to reduce it. For secondary drying, general known drying methods such as fluidized bed drying or vacuum drying can be used.

[0084] Alternatively, the spray liquid may be heated to a temperature above the melting point of the biodegradable resin, and after spraying, the biodegradable resin within the droplet may be solidified by the cooling effect caused by the vaporization of the solvent, thereby granulating the particles.

[0085] The solvent content in the particles is preferably 5% by mass or less, as measured by gas chromatography. A content of 5% by mass or less reduces the adverse effects of residual solvent, namely, the tendency for particles to stick together, leading to aggregation and a deterioration of the particle size distribution, resulting in a favorable RSF of 1.2 or less.

[0086] The amount of residual solvent in particles can be measured by adding 2 parts by mass of 2-propanol to 1 part by mass of the particles to be measured, dispersing them with ultrasound for 30 minutes, storing them in a refrigerator (5°C) for at least one day to extract the solvent from the particles, and analyzing the supernatant liquid with gas chromatography (GC-14A, manufactured by Shimadzu Corporation) to quantify the amount of solvent in the particles.

[0087] <Other processes and other means> Other processes are not particularly limited and can be selected as appropriate depending on the purpose, such as particle collection processes and classification processes.

[0088] Other means are not particularly limited and can be selected as appropriate depending on the purpose, and examples include particle collection means and classification means.

[0089] The particle collection process is a process of collecting particles obtained by the granulation process, and can be suitably carried out by a particle collection means. There are no particular restrictions on the particle collection means, and they can be appropriately selected according to the purpose, for example, cyclone collection, back filter, etc.

[0090] When producing particles containing at least two types of base materials, in which one of these at least two types of base materials is predominantly present on the surface side, the particles of this form can be formed in the granulation process by appropriately selecting the types of base materials contained in the composition.

[0091] In the granulation process, to form particles in which at least one of the two substrates is predominantly contained on the surface side, the contact angles of the at least two substrates should be different. This increases the interaction between the substrates when the solvent is vaporized from the droplet during the granulation process.

[0092] In this process, since the contact angles of at least two of the substrates are different, the substrates are more likely to undergo phase separation. As a result, one of the at least two substrates becomes predominantly contained on the surface side, and then, as the solvent vaporizes, particles solidified in this state are formed. This method allows for the formation of particles in which at least one of the two substrates is predominantly contained on the surface side in a single step.

[0093] The classification process involves classifying the particles obtained in the granulation process to obtain particles of uniform size, and can be suitably carried out by a classification means. There are no particular restrictions on the classification means, and they can be appropriately selected according to the purpose, such as filters and sieves. [Examples]

[0094] The following describes embodiments of the present invention, but the present invention is not limited in any way to these embodiments.

[0095] (Example 1-1) -Preparation of prescription solution A- A powder mixture of polylactic acid (PLA-R-001FL, manufactured by Nagase & Co., Ltd.) and zinc oxide (FINEX-50, manufactured by Sakai Chemical Industry Co., Ltd.) in a mass ratio of 2:8 was mixed with a solvent consisting of acetone and 2-propanol in a mass ratio of 1:1 to prepare formulation A with a solid content concentration of 15% by mass.

[0096] -Granulation of particle 1- Using formulation solution A, particle 1 was granulated using a spray drying method (Trispire nozzle, manufactured by GF Corporation) under the following particle manufacturing conditions.

[0097] The obtained particle 1 had a volume-average particle size (Dv) of 5.4 μm and a ratio (RSF) of 0.80. The oleic acid absorption / triglyceride absorption ratio of the particle was 5.2.

[0098] [Particle manufacturing conditions] • Spray drying method: Trispire nozzle (GF Corporation) • Granulation equipment: Spray dryer GS310 (Yamato Scientific Co., Ltd.) • Dispensing rate of the prescribed solution (under Trispier nozzle spraying conditions): 15g / min • Compressed air volume (Trispire nozzle injection conditions): 0.6 MPa, 30 NL / min • Dry air flow rate: 50m 3 / h • Dry airflow temperature: 40°C

[0099] [Measurement of volume-average particle size (Dv) and (RSF)] Using a particle size distribution analyzer (LA-960, manufactured by Horiba, Ltd.) that measures the laser diffraction / scattering method, the volume-average particle size (Dv) of the obtained particles was determined. 10 , D 50 , and D 90 We measured (RSF) = (D 90 -D 10 ) / D 50 The RSF was calculated using the following formula. For the measurement sample, a dispersion was used, obtained by adding 0.1g of DRIWEL K (manufactured by Fujifilm Corporation) and 5.0g of water to 0.003g of the target particles and ultrasonically dispersing for 3 minutes.

[0100] -Measurement conditions- ·Transmittance (R): 85~95% ·Transmittance (B): 70~90% • Algorithm option: Standard mode

[0101] [Measurement of oleic acid absorption / triglyceride absorption in particles] The maximum absorption of oleic acid or triglycerides in particles was measured using the following procedure.

[0102] Specifically, a predetermined amount of oleic acid or triglyceride (hereinafter referred to as "each component") was added to 0.4 g of particles and mixed with a spatula for 15 minutes. After that, each component that was not absorbed by the particles was removed by pressing oil-blotting paper (high-quality oil-blotting paper, 90 mm x 90 mm, manufactured by Kai Corporation) against the particles. The total mass of each component that could not be removed by the oil-blotting paper and was absorbed by the particles, along with the mass of the particles, was measured, and the mass of oleic acid or triglyceride absorbed by the particles was calculated by subtracting the mass of the particles. In order to ensure that the absorption amount was saturated, the amount of each component added was set so that the mass of each component removed by the oil-blotting paper exceeded 5% by mass of the particles.

[0103] (Examples 1-2) Particle 2 was granulated in the same manner as in Example 1-1, except that formulation B was prepared by changing the mass ratio of biodegradable resin to metal oxide in formulation A from 2:8 to 5:5.

[0104] (Examples 1-3) Particle 2 was granulated in the same manner as in Example 1-1, except that formulation C was prepared by changing the mass ratio of biodegradable resin to metal oxide in formulation A from 2:8 to 8:2.

[0105] (Examples 1-4) -Granulation of particle 4- Using formulation B, particles 4 were granulated by a spray drying method (rotary disc atomizer, manufactured by Okawara Chemical Machinery Co., Ltd.) under the following particle manufacturing conditions. The volume-average particle size (Dv) of the obtained particles 4 was 18.9 μm, and the (RSF) was 0.75. The oleic acid absorption / triglyceride absorption value of the particles was 3.5.

[0106] [Particle manufacturing conditions] • Spray drying method: Rotary disc atomizer (Okawara Chemical Machinery Co., Ltd.) • Granulation equipment: Spray dryer L-8 (Okawara Chemical Machinery Co., Ltd.) • Rotary disc atomizer rotation speed: 10,000 rpm • Dispensing rate of prescription solution: 2 kg / hour • Airflow rate for transport: 50m 3 / h • Dry airflow temperature: 50℃

[0107] (Examples 1-5) In Example 1-2, particle 5 was granulated in the same manner as in Example 1-2, except that the biodegradable resin in formulation A was changed from polylactic acid to polybutylene adipate terephthalate (PBAT, manufactured by Miyako Chemical Co., Ltd.) to prepare formulation D.

[0108] (Examples 1-6) In Example 1-2, particle 6 was granulated in the same manner as in Example 1-2, except that the biodegradable resin in formulation A was changed from polylactic acid to polyhydroxyalkanoate (BP350-15, BLUPHA Co., Ltd) to prepare formulation E.

[0109] (Examples 1-7) Particles 10 were granulated in the same manner as in Example 1-1, except that formulation H was prepared by changing the mass ratio of biodegradable resin to metal oxide in formulation A from 2:8 to 0.5:9.5.

[0110] (Examples 1-8) In Example 1-1, particle 11 was granulated in the same manner as in Example 1-1, except that the biodegradable resin in formulation A was changed from polylactic acid to hypromellose acetate succinate (HPMCAS-HG, Shin-Etsu Chemical Co., Ltd.) to prepare formulation I.

[0111] (Comparative Example 1-1) -Preparation of prescription solution F- Zinc oxide (FINEX-50, Sakai Chemical Industry Co., Ltd.) was mixed with a solvent consisting of acetone and 2-propanol in a mass ratio of 1:1 to prepare formulation solution F with a solid content concentration of 15% by mass.

[0112] -Granulation of particle 7- Using the obtained formulation F, particles 7 were granulated in the same manner as in Example 1. The volume-average particle size (Dv) of the obtained particles 7 was 1.2 μm, and the (RSF) was 1.15. The oleic acid absorption / triglyceride absorption ratio of the particles was 1.0.

[0113] (Comparative Example 1-2) -Preparation of prescription solution G- Polylactic acid (PLA-R-001FL, manufactured by Nagase & Co., Ltd.) was mixed with a solvent consisting of acetone and 2-propanol in a mass ratio of 1:1 to prepare formulation solution G with a solid content concentration of 15% by mass.

[0114] -Granulation of particle 8- Using the obtained formulation G, particles 8 were granulated in the same manner as in Example 1. The volume-average particle size (Dv) of the obtained particles 8 was 5.4 μm, and the (RSF) was 0.91. The oleic acid absorption / triglyceride absorption ratio of the particles was 1.0.

[0115] (Comparative Examples 1-3) -Granulation of particle 9- Using formulation B, particles 9 were granulated by a spray drying method (single-fluid nozzle, manufactured by Okawara Chemical Machinery Co., Ltd.) under the following particle manufacturing conditions. The volume-average particle size (Dv) of the obtained particles 9 was 82.2 μm, and the (RSF) was 2.5. The oleic acid absorption / triglyceride absorption ratio of the particles was 1.1.

[0116] [Particle manufacturing conditions] • Spray drying method: 1-fluid nozzle (Okawara Chemical Machinery Co., Ltd.) • Granulation equipment: Spray dryer L-8 (Okawara Chemical Machinery Co., Ltd.) • Dispensing rate of prescription solution: 2 kg / hour • Airflow rate for transport: 50m 3 / h • Dry airflow temperature: 50℃

[0117] Table 1 shows the manufacturing conditions for particles 1 to 11. In Table 1, "PLA" represents "polylactic acid," "PBAT" represents "polybutylene adipate terephthalate," and "PHBH" represents "poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)."

[0118] [Table 1]

[0119] (Example 2-1) <How to make powder foundation> In Example 1, 10 parts by mass of the particles produced were mixed with 21 parts by mass of sericite, 56 parts by mass of muscovite, 0.6 parts by mass of red iron oxide, 1 part by mass of yellow iron oxide, and 0.1 parts by mass of black iron oxide as pigments using a Henschel mixer to prepare a mixture. Meanwhile, 10 parts by mass of cetyl 2-ethylhexanoate as an oily base material, 1 part by mass of sorbitan sesquioleate as an emulsifier, and 0.2 parts by mass of a preservative were mixed and dissolved to prepare a solution. The prepared mixture and the solution were uniformly mixed, and 0.1 parts by mass of fragrance was added and mixed uniformly again. After that, the mixture was pulverized and passed through a sieve to prepare a foundation material. This foundation material was compressed and molded into a metal tray to produce the powder foundation of Example 1.

[0120] (Examples 2-2 to 2-8, and Comparative Examples 2-1 to 2-3) Powder foundations for Examples 2-2 to 2-8 and Comparative Examples 2-1 to 2-3 were prepared in the same manner as in Example 2-1, except that particle 1 was changed to particles 2-6, 10-11, and 7-9, respectively.

[0121] (evaluation) Ten panelists used each of the powder foundations for three days and evaluated their resistance to makeup breakdown (how long-lasting the makeup was). The evaluation criteria were based on the following five-point scale, and the average of the evaluation results from the ten panelists was calculated as the final evaluation result. An average score of 4.0 or higher was considered a passing grade. The results are shown in Table 2.

[0122] -Evaluation Criteria- 5: The makeup lasts very well. 4. Makeup lasts well. 3: Makeup lasts relatively well. 2: The makeup doesn't last very long. 1: Makeup doesn't last long.

[0123] [Table 2]

[0124] The results from Examples 2-1 to 2-8 show that using a cosmetic composition containing particles that include biodegradable resin and metal oxides, wherein the oleic acid absorption / triglyceride absorption ratio of the particles is 1.5 or higher, the volume-average particle size is between 3 μm and 50 μm, and the Relative Span Factor (RSF) is 1.2 or lower, results in superior makeup longevity.

[0125] On the other hand, the results from Comparative Examples 2-1 to 2-3 show that if the ratio of oleic acid absorption to triglyceride absorption in the particles is 1.5 or less, the makeup will not last long.

[0126] Although the present invention has been described above based on various embodiments, the present invention is not limited to the requirements shown in the above embodiments. These points can be modified as long as they do not impair the spirit of the present invention, and can be appropriately determined according to their application.

[0127] The embodiments of the present invention are, for example, as follows. <1> Particles containing a biodegradable resin and a metal oxide, Particles characterized in that the ratio of oleic acid absorption to triglyceride absorption in the aforementioned particles is 1.5 or greater. <2> The volume-average particle size is between 3 μm and 50 μm. The Relative Span Factor (RSF) is 1.2 or less. <1> The particles described. <3> The mass ratio (B / M) of the biodegradable resin (B) to the metal oxide (M) is 0.5 / 9.5 or more and 8 / 2 or less. <1> or <2> The particles described. <4> The metal oxide is zinc oxide. <1> from <3> A particle as described in any one of the items. <5> The volume-average particle size of the metal oxide is 10 nm or more and 200 nm or less. <1> from <4> A particle as described in any one of the items. <6> The biodegradable resin contains at least one of polylactic acid and polylactic acid glycolic acid copolymer. <1> from <5> A particle as described in any one of the items. <7> The biodegradable resin contains a polyhydroxyalkanoate. <1> from <6> A particle as described in any one of the items. <8> The polyhydroxyalkanoate is poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) <7> The particles described. <9> The biodegradable resin contains polybutylene adipate terephthalate. <1> from <8> A particle as described in any one of the items. <10> The biodegradable resin contains hypromellose acetate succinate. <1> from <9> A particle as described in any one of the items. <11> The aforementioned <1> from <10> A cosmetic composition characterized by containing the particles described in any one of the items. <12> The aforementioned foundation, blush, eyeshadow, cleansing agent, facial cleansing cream, sunscreen cream, antiperspirant, or pre-shave lotion. <11> Cosmetics as described above. <13> The aforementioned <1> from <10> A method for producing particles according to any one of the items, A step of discharging a mixture containing the biodegradable resin, the metal oxide, and the solvent as droplets into a gas, A step of removing the solvent from the droplet to granulate particles, A method for producing particles, characterized by containing [the specified element]. <14> The solvent is a mixture of a good solvent for the biodegradable resin and a poor solvent for the biodegradable resin. <13> A method for producing the particles described above.

[0128] The aforementioned <1> from <10> Particles according to any one of the items, <11> or <12> The cosmetics described above, and the aforementioned <13> or <14> The method for producing resin particles described above can solve the aforementioned problems of the conventional method and achieve the objectives of the present invention. [Prior art documents] [Patent Documents]

[0129] [Patent Document 1] Japanese Patent Application Publication No. 9-227792 [Patent Document 2] Japanese Patent Application Publication No. 10-87420 [Patent Document 3] Japanese Patent Publication No. 2002-20218

Claims

1. Particles containing a biodegradable resin and a metal oxide, Particles characterized in that the ratio of oleic acid absorption to triglyceride absorption in the aforementioned particles is 1.5 or greater.

2. The volume-average particle size is 3 μm or more and 50 μm or less. The particle according to claim 1, wherein the Relative Span Factor (R.S.F) is 1.2 or less.

3. The particles according to claim 1 or 2, wherein the mass ratio (B / M) of the biodegradable resin (B) to the metal oxide (M) is 0.5 / 9.5 or more and 8 / 2 or less.

4. The particles according to claim 1 or 2, wherein the metal oxide is zinc oxide.

5. The particle according to claim 1 or 2, wherein the volume-average particle size of the metal oxide is 10 nm or more and 200 nm or less.

6. The particles according to claim 1 or 2, wherein the biodegradable resin contains at least one of polylactic acid and polylactic acid glycolic acid copolymer.

7. The particles according to claim 1 or 2, wherein the biodegradable resin contains a polyhydroxyalkanoate.

8. The particle according to claim 7, wherein the polyhydroxyalkanoate is poly(3-hydroxybutyrate-co-3-hydroxyhexanoate).

9. The particles according to claim 1 or 2, wherein the biodegradable resin contains polybutylene adipate terephthalate.

10. The particles according to claim 1 or 2, wherein the biodegradable resin contains hypromellose acetate succinate.

11. A cosmetic composition characterized by containing the particles described in claim 1 or 2.

12. The cosmetic composition according to claim 11, which is a foundation, blush, eyeshadow, cleansing agent, facial cleansing cream, sunscreen cream, antiperspirant, or pre-shave lotion.

13. A method for producing particles according to claim 1 or 2, A step of discharging a mixture containing the biodegradable resin, the metal oxide, and the solvent as droplets into a gas, A step of removing the solvent from the droplet to granulate particles, A method for producing particles, characterized by containing [the specified element].

14. The method for producing particles according to claim 13, wherein the solvent is a mixture of a good solvent for the biodegradable resin and a poor solvent for the biodegradable resin.

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