Resin particles and their applications

Abstract

The present invention addresses the problem of providing polyhydroxyalkanoate resin particles having reduced odor. As a means for solving the problem, provided are the following polyhydroxyalkanoate resin particles (i) to (iii): (i) polyhydroxyalkanoate resin particles in which the total remaining amount of unsaturated fatty acids is 10 mass ppm or less; (ii) polyhydroxyalkanoate resin particles in which the total remaining amount of crotonic acid is 10 mass ppm or less; and (iii) polyhydroxyalkanoate resin particles in which the total remaining amount of pentenoic acid is 60 mass ppm or less.

Description

[Technical Field]

[0001] The present invention relates to resin particles and uses thereof. More specifically, it relates to resin particles, an external preparation containing the resin particles, a coating material containing the resin particles, a resin composition containing the resin particles, and an antiblocking agent containing the resin particles. [Background Art]

[0002] Since the specific surface area, particle shape and particle structure of resin particles can be arbitrarily adjusted, modification and improvement of physical properties are performed by blending them into various materials, articles and the like. Main applications of resin particles include compounding agents for cosmetics such as foundations, antiperspirants and scrub agents, matting agents for coating materials (paints), rheology modifiers, antiblocking agents, slippage imparting agents, light diffusing agents, various agents such as medical diagnostic test agents, and additives to molded articles such as automotive materials and construction materials. Examples of the resin particles include urethane, acrylic, silicone, polyethylene and the like.

[0003] On the other hand, with increasing interest in environmental issues in recent years, in order to reduce environmental loads such as the microplastics problem, the use of non-petroleum derived materials and biodegradable materials is required in all fields where resins are used. For example, such a requirement is also demanded in fields where resin particles are used, such as cosmetics and coating materials (paints).

[0004] Under such circumstances, various biodegradable resin particles are known. Patent Document 1 describes cellulose acetate particles having an average particle diameter of 80 nm or more and 100 µm or less, a sphericity of 0.7 or more and 1.0 or less, a surface smoothness of 80% or more and 100% or less, and a total acetyl substitution degree of cellulose acetate of 0.7 or more and 2.9 or less. It is described that these cellulose acetate particles are excellent in biodegradability and tactile feel, and can be used by being blended into cosmetic compositions. Patent Document 2 describes aliphatic polyester resin particles having a volume average particle diameter of 2 to 30 μm, a proportion of particles with a particle diameter of less than 1 μm of 15 volume% or less, and a proportion of particles with a particle diameter exceeding 30 μm of 6 volume% or less. Cosmetics containing these aliphatic polyester resin particles are described as being environmentally friendly and having excellent spreadability, adhesion, tactile properties (no foreign body sensation or squeaky feeling, and possessing softness, slipperiness, and smoothness) and transparency when applied. Patent Document 3 describes polyhydroxyalkanoate particles obtained by crushing aggregates of primary particles. These polyhydroxyalkanoate particles can be used as a matting agent or nail polish remover in coating compositions, and it is said that they can reduce the proportion of petrochemicals while producing a coating that is better than, or comparable to, conventional coatings containing petrochemical-based matting agents. Patent Document 4 describes biodegradable resin particles made of polyhydroxyalkanoate, with a Ca content of 10 to 10,000 ppm, a volume-average particle diameter of 2 to 50 μm, and a BET specific surface area of ​​0.8 to 10 m². 2 The document describes biodegradable resin particles with a density of 50-300 ml / 100g and a linseed oil absorption capacity of 50-300 ml / 100g. These biodegradable resin particles have a small particle size and, when applied to the skin, exhibit excellent adhesion to the skin and a light, smooth spread on the skin, making them suitable for use in topical preparations such as cosmetics and quasi-drugs. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Patent No. 6609726 [Patent Document 2] International Publication No. 2017 / 195642 [Patent Document 3] Patent No. 5671631 [Patent Document 4] International Publication No. 2020 / 262509 [Overview of the project] [Problems that the invention aims to solve]

[0006] Cellulose acetate particles had a strong squeaky texture, which posed problems in terms of tactile feel when incorporated into cosmetics. Furthermore, there were issues with odor due to components produced by hydrolysis, and their biodegradability in water was unsatisfactory. The aliphatic polyester resin particles described in Patent Document 2 and the biodegradable resin particles made of polyhydroxyalkanoates described in Patent Documents 3 and 4 have not been studied in terms of heat resistance, odor, or biodegradability in water. Furthermore, the polyhydroxyalkanoate particles described in Patent Document 3 are obtained by pulverizing with a jet mill, resulting in an unstable particle shape. When incorporated into cosmetics, the feel during application was unsatisfactory.

[0007] The first problem that the present invention aims to solve is to provide polyhydroxyalkanoate-based resin particles with suppressed odor. The second problem that the present invention aims to solve is to provide polyhydroxyalkanoate resin particles that have suppressed odor, excellent biodegradability in water, and less squeaking. The third problem that the present invention aims to solve is to provide polyhydroxyalkanoate resin particles that have suppressed odor, excellent biodegradability in water, less squeaky feeling, and excellent dispersibility in topical preparations. The fourth problem that the present invention aims to solve is to provide one or more topical agents containing the polyhydroxyalkanoate resin particles, coating materials containing the polyhydroxyalkanoate resin particles, resin compositions containing the polyhydroxyalkanoate resin particles, and anti-blocking agents containing the polyhydroxyalkanoate resin particles. [Means for solving the problem]

[0008] As a result of diligent research to solve the aforementioned problems, the present inventors have found that the aforementioned problems can be solved by specific polyhydroxyalkanoate resin particles, and have completed the present invention. The invention that solves the first problem of the present invention is the invention described in items 1 to 4 below. The invention that solves the second problem of the present invention is the invention described in item 5 below. The invention that solves the third problem of the present invention is the invention described in item 6 below. The invention that solves the fourth problem of the present invention is the invention described in items 7 to 10 below. [Item 1] Polyhydroxyalkanoate resin particles having a total residual amount of unsaturated fatty acids of 10 ppm by mass or less. [Item 2] Polyhydroxyalkanoate resin particles having a total residual amount of crotonic acid of 10 ppm by mass or less. [Item 3] Polyhydroxyalkanoate resin particles having a total residual amount of pentenoic acid of 60 ppm by mass or less. [Item 4] Polyhydroxyalkanoate resin particles according to any one of items 1 to 3, wherein the polyhydroxyalkanoate resin comprises a poly(3-hydroxybutyrate-co-3-hydroxyvaliate) resin. [Item 5] Polyhydroxyalkanoate resin particles according to any one of Items 1 to 4, wherein the volume average particle diameter is 1 μm or more and 40 μm or less. [Item 6] Polyhydroxyalkanoate resin particles according to any one of items 1 to 5, wherein the moisture content is 0.2% by mass or more and 0.8% by mass or less. [Item 7] A topical preparation containing polyhydroxyalkanoate resin particles as described in any one of items 1 to 6. [Item 8] A coating material comprising polyhydroxyalkanoate resin particles as described in any one of items 1 to 6. [Item 9] A resin composition comprising polyhydroxyalkanoate resin particles as described in any one of items 1 to 6. [Item 10] An antiblocking agent comprising polyhydroxyalkanoate resin particles as described in any one of items 1 to 6. [Effects of the Invention]

[0009] The present invention provides polyhydroxyalkanoate resin particles in which the total residual amount of unsaturated fatty acids is within a specific range, polyhydroxyalkanoate resin particles in which the total residual amount of crotonic acid is within a specific range, and polyhydroxyalkanoate resin particles in which the total residual amount of pentenoic acid is within a specific range, thereby providing polyhydroxyalkanoate resin particles with suppressed odor. The present invention provides polyhydroxyalkanoate resin particles in which the total residual amount of unsaturated fatty acids and the volume-average particle diameter are within a specific range, and which have suppressed odor, excellent biodegradability in water, and less squeaking. The present invention provides polyhydroxyalkanoate resin particles in which the total residual amount of unsaturated fatty acids, volume-average particle size, and water content are within a specific range, and which have suppressed odor, excellent biodegradability in water, less squeaky feeling, and excellent dispersibility in topical preparations. The present invention provides a topical agent containing specific polyhydroxyalkanoate resin particles, a coating material containing specific polyhydroxyalkanoate resin particles, a resin composition containing specific polyhydroxyalkanoate resin particles, and an antiblocking agent containing specific polyhydroxyalkanoate resin particles. [Modes for carrying out the invention]

[0010] The resin particles of the present invention, the topical agent containing the resin particles, the coating material containing the resin particles, the resin composition containing the resin particles, and the anti-blocking agent containing the resin particles will be described in detail below. Furthermore, within this specification, numerical ranges may be any combination of the upper and lower limits described.

[0011] [Polyhydroxyalkanoate resin particles] In the present invention, the polyhydroxyalkanoate resin particles are those in which the resin particles are substantially composed of a polyhydroxyalkanoate resin, and other components may be contained within the resin particles. The resin particles may contain one type of polyhydroxyalkanoate resin alone, or they may contain two or more types of polyhydroxyalkanoate resins. Other components include, for example, various components used in the manufacturing of resin particles, and various components added to improve the properties of the resin particles.

[0012] <Polyhydroxyalkanoate resins> The polyhydroxyalkanoate resin constituting the polyhydroxyalkanoate resin particles of the present invention is a biodegradable resin containing repeating units derived from aliphatic hydroxycarboxylic acids, and may be a homopolymer or a copolymer. Examples of aliphatic hydroxycarboxylic acids include one or more selected from the group consisting of 3-hydroxypropionate, 3-hydroxybutyrate, 3-hydroxyvalate, 3-hydroxyhexanoate, 3-hydroxyheptanoate, 3-hydroxyoctanoate, 3-hydroxynonanoate, 3-hydroxydecanoate, 3-hydroxyundecanoate, 3-hydroxydodecanoate, 3-hydroxytetradecanoate, 3-hydroxyhexadecanoate, 3-hydroxyoctadecanoate, lactic acid, 4-hydroxybutyrate, 4-hydroxyvalerate, 5-hydroxyvalerate, 6-hydroxyhexanoate, etc.

[0013] Polyhydroxyalkanoate resins are based on the general formula (1); -[-CH(R)-CH2CO-O-]- (1) (However, R in equation (1) is -C) n H 2n+1 This is an alkyl group represented by , where n is an integer between 1 and 15. It is preferable that the polymer or copolymer is a poly(3-hydroxyalkanoate) polymer or copolymer containing repeating units represented by .

[0014] In the present invention, it is preferable that the polyhydroxyalkanoate resin has 3-hydroxybutyrate units as its main component (for example, 50 mol% or more, preferably 80 mol% or more). For example, it is preferable that the main component be one or more selected from the group consisting of poly(3-hydroxybutyrate-co-3-hydroxyvariate) resin, which is a copolymer of 3-hydroxybutyrate units and 3-hydroxyvariate units; poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) resin, which is a copolymer of 3-hydroxybutyrate units and 3-hydroxyhexanoate units; and it is more preferable that the main component be poly(3-hydroxybutyrate-co-3-hydroxyoctanoate) resin.

[0015] As a polyhydroxyalkanoate resin, a resin mainly composed of 3-hydroxybutyrate units (for example, 50 mol% or more, preferably 80 mol% or more), such as poly(3-hydroxybutyrate-co-3-hydroxyvariate) resin, poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) resin, poly(3-hydroxybutyrate-co-3-hydroxyoctanoate) resin, preferably poly(3-hydroxybutyrate-co-3-hydroxyvariate) resin, is available. This provides excellent biodegradability, especially in water biodegradability, and can address the microplastics problem that has become an issue in recent years. Furthermore, by having a specific color value, it is easier to match the color and less noticeable than ordinary white particles, especially when used as a lubricant for foundations or as a compounding agent for antiperspirants in cosmetics.

[0016] <Total residual amount of unsaturated fatty acids, crotonic acid, or pentenoic acid> In one embodiment of the present invention, the polyhydroxyalkanoate resin particles have a total residual amount of unsaturated fatty acids of 10 ppm by mass or less relative to the entire polyhydroxyalkanoate resin particle. Preferably, it is 8 ppm by mass or less, more preferably 6 ppm by mass or less, and even more preferably 5 ppm by mass or less. In one embodiment of the present invention, the polyhydroxyalkanoate resin particles have a total residual amount of crotonic acid of 10 ppm by mass or less relative to the entire polyhydroxyalkanoate resin particles. Preferably, it is 8 ppm by mass or less, more preferably 6 ppm by mass or less, and even more preferably 5 ppm by mass or less. In one embodiment of the present invention, the polyhydroxyalkanoate resin particles have a total residual amount of pentenoic acid of 60 ppm by mass or less relative to the entire polyhydroxyalkanoate resin particles. Preferably, it is 30 ppm by mass or less, more preferably 10 ppm by mass or less, and even more preferably 5 ppm by mass or less.

[0017] Polyhydroxyalkanoate resins decompose in part due to heat, etc., generating unsaturated fatty acids. For example, crotonic acid is generated from the 3-hydroxybutyrate unit in the polyhydroxyalkanoate resin, 2-pentenoic acid, 3-pentenoic acid, 4-pentenoic acid from the 3-hydroxyvalilate unit, 2-hexenoic acid from the 3-hydroxyhexanoate unit, and 2-octenoic acid from the 3-hydroxyoctanoate unit. These unsaturated fatty acids are contained within the polyhydroxyalkanoate resin particles. Because these unsaturated fatty acids emit a distinctive odor, if polyhydroxyalkanoate resin particles are incorporated into topical preparations, etc., there is a risk that the preparations may acquire an unpleasant odor, causing problems. The total residual amount of unsaturated fatty acids is measured by the method described in the examples below.

[0018] <Volume-average particle size> The volume-average particle diameter of the polyhydroxyalkanoate resin particles of the present invention is not particularly limited. For example, it is 1 μm or more, preferably 3 μm or more, more preferably 5 μm or more, and particularly preferably 6 μm or more, and for example, 40 μm or less, preferably 33 μm or less, more preferably 30 μm or less, and particularly preferably 25 μm or less. If the volume-average particle diameter is less than 1 μm, squeaking is likely to occur in topical preparations containing polyhydroxyalkanoate resin particles, and the feel of the topical preparation containing polyhydroxyalkanoate resin particles when applied (the feel when applied to the skin) may be poor. If the volume-average particle diameter is greater than 40 μm, the feel of the topical preparation containing polyhydroxyalkanoate resin particles when applied (the feel when applied to the skin) may be poor. The volume-average particle size is measured by the method described in the examples below.

[0019] <Moisture content> The water content of the polyhydroxyalkanoate resin particles of the present invention is not particularly limited. For example, it is 0.2% by mass or more, preferably 0.3% by mass or more, and for example, 0.8% by mass or less, preferably 0.7% by mass or less. If the water content is less than 0.2% by mass or more than 0.8% by mass, when the polyhydroxyalkanoate resin particles are added to a topical preparation, uniform dispersion in the topical preparation may not be possible. Here, the water content of the polyhydroxyalkanoate resin particles represents the amount of water contained in the polyhydroxyalkanoate resin particles when the total mass of the polyhydroxyalkanoate resin particles is set to 100%. The moisture content can be measured, for example, by the method described in the examples below.

[0020] <Average circularity> The average circularity of the polyhydroxyalkanoate-based resin particles of the present invention is not particularly limited. For example, it is 0.75 or more, preferably 0.78 or more, more preferably 0.8 or more, and for example, 1.0 or less, preferably 0.99 or less. By setting the average circularity to 0.8 or more, excellent feel during application can be obtained for an external preparation containing the polyhydroxyalkanoate-based resin particles. The average circularity is measured by the method described in the Examples below.

[0021] <Color Tone> The color tone of the polyhydroxyalkanoate-based resin particles of the present invention is not particularly limited. L * a * b * L in the color system * value is, for example, 70 or more, preferably 75 or more, more preferably 80 or more. L * a * b * a in the L*a*b* color system * value is, for example, -3.0 or more, preferably -2.5 or more, more preferably -2.0 or more, and for example, +2.0 or less, preferably +1.5 or less, more preferably +1.0 or less. L * a * b * b in the L*a*b* color system * value is, for example, +1.0 or more, preferably +1.5 or more, more preferably +2.0 or more, and for example, +7.0 or less, preferably +6.5 or less, more preferably +6.0 or less. Preferably, in the L * a * b * color system, L * value is 70 or more, a * is -3.0 or more and +2.0 or less, b * value is +1.0 or more and +7.0 or less; more preferably, in the L * a * b * color system, L * value is 80 or more, a * value is -2.0 or more and +1.0 or less, b *The value is between +2.0 and +6.0.

[0022] L * a * b * Color system (L * a * b * The color space (L) is a color system that was standardized by the International Commission on Illumination (CIE) in 1976 and is adopted in Japan by JIS Z 8781-4. * a * b * A color system is a color system that is commonly used to represent the colors of objects. L * a * b * In a color system, L * The value is an indicator of the brightness of the color. L * The closer the value is to 100, the lighter the color becomes (white), and the closer it is to 0, the darker the color becomes (black). L * a * b * In a color system, a * The value is an index that indicates the intensity of red and green hues. * The value indicates a reddish hue as you move towards the positive (+) direction, and a greenish hue as you move towards the negative (-) direction. L * a * b * In a color system, b * The value is an index indicating the intensity of yellow and blue hues. * The value indicates a yellow hue as you move towards the positive (+) direction, and a blue hue as you move towards the negative (-) direction.

[0023] L * a * b * L in color systems * value, a * Value and b *When polyhydroxyalkanoate resin particles having specific color values, each within the aforementioned specific range, are used as a compounding agent in topical preparations (cosmetics) such as a lubrication agent for foundation or an antiperspirant, it is preferable because the color is easier to match than with ordinary white particles, and the polyhydroxyalkanoate resin particles are less noticeable, resulting in a natural finish.

[0024] <Other ingredients> The polyhydroxyalkanoate resin particles of the present invention may optionally contain fluidity modifiers, ultraviolet absorbers, light stabilizers, pigments (e.g., extender pigments, coloring pigments, metallic pigments, mica powder pigments, etc.), dyes, humectants, surfactants, resins other than polyhydroxyalkanoate resins, fragrances, clay minerals, preservatives / bactericides, anti-inflammatory agents, antioxidants, ultraviolet absorbers, pH adjusters (e.g., triethanolamine), special compounding additives, pharmaceutical active ingredients, etc.

[0025] <Application> The polyhydroxyalkanoate resin particles of the present invention can be used in various applications such as compounding agents for external preparations including various cosmetics such as foundations, antiperspirants, and scrubs; compounding agents for coating materials; compounding agents for resin compositions; antiblocking agents; matting agents for coating materials (paints); rheology modifiers; lubricity enhancers; light diffusing agents; auxiliary agents for fine ceramic sintering molding; fillers for adhesives; medical diagnostic testing agents; and additives to molded products such as automotive materials and building materials.

[0026] <Method for producing polyhydroxyalkanoate resin particles> The method for producing polyhydroxyalkanoate-based resin particles of the present invention is not particularly limited. For example, (I) A manufacturing method (Manufacturing Method I) comprising the steps of mixing and kneading a molten polyhydroxyalkanoate resin with an aqueous emulsifier to obtain a polyhydroxyalkanoate resin slurry, washing and dewatering the slurry, drying the resulting polyhydroxyalkanoate resin particle cake, and then crushing it. (II) A manufacturing method (Manufacturing Method II) comprising the steps of heating a polyhydroxyalkanoate resin in the presence of an organic solvent containing an alcohol-based solvent, water, and a dispersion stabilizer to emulsify and disperse it, cooling to obtain a dispersion of the polyhydroxyalkanoate resin, and then separating and drying the polyhydroxyalkanoate resin particles from the dispersion. These are some examples.

[0027] <Manufacturing method I> Examples of manufacturing methods I for producing polyhydroxyalkanoate-based resin particles of the present invention include a manufacturing method that includes the steps shown in (I-1) to (I-4) below. (I-1) A process to obtain a polyhydroxyalkanoate resin slurry by mixing and kneading a polyhydroxyalkanoate resin raw material powder or polyhydroxyalkanoate resin raw material pellets with an emulsifier aqueous solution using a disperser, thereby mixing and kneading the molten polyhydroxyalkanoate resin with the emulsifier aqueous solution (kneading and slurry formation process). (I-2) Washing and dewatering process of polyhydroxyalkanoate resin slurry (washing and dewatering process) (I-3) A step to obtain polyhydroxyalkanoate resin particles by drying the cake of polyhydroxyalkanoate resin particles obtained in (I-2) above, crushing it, and classifying it if necessary (particle formation step).

[0028] The polyhydroxyalkanoate resin particles obtained by the steps (I-1) to (I-3) described above have a reduction in the total residual amount of unsaturated fatty acids such as crotonic acid, hexenoic acid, and pentenoic acid, which are decomposition products, as well as a reduction in the total residual amount of crotonic acid and pentenoic acid. This makes it possible to suppress the odor of the polyhydroxyalkanoate resin particles.

[0029] (Mixing and slurrying process) {Emulsifier aqueous solution} The aqueous emulsifier solution used in the mixing and slurrying process is not particularly limited as long as it contains at least an emulsifier and water as components and can emulsify the molten polyhydroxyalkanoate resin and form a slurry.

[0030] The emulsifier constituting the aqueous emulsifier solution is not particularly limited. Examples include one or more surfactants selected from the group consisting of: anionic surfactants containing fatty acid salts with 4 to 18 carbon atoms, such as sodium lauryl sulfate and sodium oleate; cationic surfactants such as lauryltrimethylammonium chloride; amphoteric surfactants such as N-laurylglycine; and nonionic surfactants such as nonylphenyl polyethylene oxide, glycerin fatty acid esters, sucrose fatty acid esters, sorbitan fatty acid esters, propylene glycol fatty acid esters, lecithin, and alkylene oxide adducts thereof. Furthermore, natural polymers such as starch, casein, gelatin, alginic acid, alginates, locust bean gum, guar gum, gum arabic, xanthan gum, agar, carrageenan, crystalline cellulose, and pectin; semi-synthetic polymers such as hydroxyethylcellulose, methylcellulose, carboxymethylcellulose, propylene glycol alginate, and cationic modified starch; polyvinyl alcohol-based resins, polyacrylamide, polyvinylpyrrolidone, polyacrylic acid, polyethyleneimine, and their anionic or cationic forms. One or more selected from the group consisting of hydrophobic modified products, hydrophobic modified products thereof, poly(meth)acrylic acid, polyvinylpyrrolidone, polyvinylamine, poly(anhydride)maleic acid, polystyrene sulfonic acid, copolymers of (meth)acrylic acid or maleic anhydride with vinyl monomers (e.g., (meth)acrylic acid esters, aromatic vinyl monomers (styrene, etc.), olefin monomers, etc.), modified polyesters (modified products using succinic anhydride, maleic anhydride, polyethylene oxide, etc.), and water-soluble polymers such as polyoxyethylene polymers.

[0031] In the present invention, considering the possibility of residual emulsifier, a biodegradable emulsifier is preferred. For example, one or more emulsifiers selected from the group consisting of polyvinyl alcohol resins (polyvinyl alcohol, partially saponified polyvinyl alcohol, partially saponified polyvinyl alcohol containing functional groups (e.g., sulfonic acid groups, carboxyl groups, amino groups, etc.), partially saponified polyvinyl alcohol containing terminal hydrophobic groups, etc.), starch, modified polyesters (modified products using succinic anhydride, maleic anhydride, polyethylene oxide, etc.), and polyoxyethylene polymers are preferred. Particularly preferred is a polyvinyl alcohol resin.

[0032] {Dispersion machine} The disperser is not particularly limited as long as it can melt the polyhydroxyalkanoate resin raw material powder or polyhydroxyalkanoate resin raw material pellets and apply the shear force necessary to atomize the molten polyhydroxyalkanoate resin. Examples include those selected from the group consisting of various extruders, homomixers, homogenizers, colloid mills, kneader-ruders, high-performance dispersers, and stirrers for high-viscosity liquids. Preferably, it is a screw extruder, and more preferably, a twin-screw co-direction extruder or a single-screw extruder.

[0033] The method for mixing and kneading polyhydroxyalkanoate resin raw material powder or polyhydroxyalkanoate resin raw material pellets with an aqueous emulsifier solution using a dispersion means is not particularly limited. For example, (i) A method of adding an aqueous emulsifier solution to a molten polyhydroxyalkanoate resin while stirring. (ii) A method of simultaneously charging and mixing polyhydroxyalkanoate resin raw material powder or polyhydroxyalkanoate resin raw material pellets and an emulsifier aqueous solution, These are some examples. When using an extruder, method (i) above is preferred.

[0034] In the method described in (i) above, when using a screw extruder such as a twin-screw co-direction extruder, it is preferable to continuously supply polyhydroxyalkanoate resin raw material powder or polyhydroxyalkanoate resin raw material pellets from the hopper portion of the extruder, and to continuously inject an emulsifier aqueous solution under pressure from a supply port installed at any position other than the resin melting point of the extruder, and to mix and knead the mixture. Multiple supply ports for the emulsifier aqueous solution may be provided as needed. This allows for the melting of the polyhydroxyalkanoate resin, mixing with the emulsifier aqueous solution, and kneading, enabling the continuous production of a polyhydroxyalkanoate resin slurry.

[0035] (Washing and dewatering process) The washing and dewatering process includes adding water to the polyhydroxyalkanoate resin slurry obtained in the kneading and slurrying process, followed by dewatering, and can be performed one or more times. The washing and dewatering process washes the polyhydroxyalkanoate resin in the polyhydroxyalkanoate resin slurry, and dewatering it yields a cake of polyhydroxyalkanoate resin particles. For example, a centrifugal dewatering machine or a pressure dewatering machine can be used for the dewatering process. In the washing and dewatering process, the amount of water added, the number of washing and dewatering processes, and the dewatering conditions are not particularly limited and can be set as appropriate.

[0036] (Particle formation process) The particle formation step includes drying the cake of polyhydroxyalkanoate resin particles obtained in the washing and dewatering step, then crushing it, and classifying it if necessary, thereby obtaining polyhydroxyalkanoate resin particles. Drying and crushing conditions are not particularly limited and can be set as appropriate. The polyhydroxyalkanoate resin particles after crushing may be classified as needed. Classification methods include wind classification, airflow classification, and screen classification. Classification is preferably carried out in an air atmosphere with a relative humidity of 30% or less, preferably 20% or less, so that the polyhydroxyalkanoate resin particles do not absorb moisture from the air. The obtained polyhydroxyalkanoate resin particles are preferably sealed in a moisture-impermeable packaging material and stored as a packaged product to prevent them from absorbing moisture from the air.

[0037] <Manufacturing method II> Examples of manufacturing methods II for producing polyhydroxyalkanoate-based resin particles of the present invention include, for example, a manufacturing method that includes the steps shown in (II-1) to (II-4) below. (II-1) A step to obtain a dispersion of polyhydroxyalkanoate resin by heating and stirring a polyhydroxyalkanoate resin in the presence of an organic solvent containing at least one alcohol-based solvent, water, and a dispersion stabilizer at a temperature of 110°C to 180°C, for example (emulsification and dispersion step). (II-2) A step to obtain a polyhydroxyalkanoate resin particle dispersion coated with a dispersion stabilizer on the surface by cooling (cooling and particle formation step) (II-3) If necessary, remove the coated dispersion stabilizer to obtain a polyhydroxyalkanoate resin particle dispersion from which the surface dispersion stabilizer has been removed (dispersion stabilizer removal step). (II-4) A step to obtain polyhydroxyalkanoate resin particles by filtering, washing, dewatering, drying, and classifying the polyhydroxyalkanoate resin particle dispersion obtained in (II-2) or (II-3) above (particle formation step).

[0038] The polyhydroxyalkanoate resin particles obtained by the steps (II-1) to (II-4) described above have a reduced total residual amount of unsaturated fatty acids such as crotonic acid, hexenoic acid, and pentenoic acid, as well as a reduced total residual amount of crotonic acid and pentenoic acid, and further reduced content of organic solvents, etc. This makes it possible to suppress the odor of the polyhydroxyalkanoate resin particles.

[0039] (Emulsification / dispersion process) {organic solvents including alcohol-based solvents} In the method for producing polyhydroxyalkanoate resin particles II of the present invention, the alcohol-based solvent contained in the organic solvent used in the emulsification and dispersion step is not particularly limited. For example, one or more selected from the group consisting of methanol, ethanol, propanol, hexanol, ethylene glycol, diethylene glycol, 3-alkoxy-3-methyl-1-butanol, and 3-alkoxy-3-methyl-1-butyl acetate (where the alkoxy group has 1 to 5 carbon atoms in each case). In the present invention, it is preferable to include 3-alkoxy-3-methyl-1-butanol and / or 3-alkoxy-3-methyl-1-butyl acetate (hereinafter also referred to as the specific solvent). The proportion of the specific solvent in the organic solvent is, from the viewpoint of oil absorption properties and particle formation, for example, 10% by mass or more, preferably 20% by mass or more, more preferably 30% by mass or more, and for example, 90% by mass or less, preferably 80% by mass or less, more preferably 70% by mass or less. Examples of solvents other than the specific solvent that may be included in the organic solvent include lower alcohols such as methanol and ethanol, and acetate ester solvents such as ethyl acetate and butyl acetate.

[0040] As a specific solvent, a solvent commercially available from Kuraray under the trade name Solfit can also be used. Furthermore, 3-alkoxy-3-methyl-1-butanol can be produced by known methods (e.g., methods described in International Publication No. 2013 / 146370, etc.). The number of carbon atoms in the alkoxy groups in the specific solvent is independently 1 to 5. If the number of carbon atoms in the alkoxy group is greater than 5, solubility may deteriorate. Specific examples of alkoxy groups include methoxy, ethoxy, propoxy, butoxy, and pentyloxy groups. Propoxy, butoxy, and pentyloxy groups include not only linear forms but also possible structural isomers. Preferred alkoxy groups are methoxy, ethoxy, and propoxy groups.

[0041] 3-alkoxy-3-methyl-1-butanol and 3-alkoxy-3-methyl-1-butyl acetate (both with 1 to 5 carbon atoms in the alkoxy group) are highly safe alcohol-based solvents. Using these solvents, it is possible to produce spherical polyhydroxyalkanoate resin particles with controlled volume-average particle size, a narrow particle size distribution, and excellent color. Furthermore, 3-alkoxy-3-methyl-1-butanol and / or 3-alkoxy-3-methyl-1-butyl acetate are biodegradable and low in skin irritant, thus minimizing adverse effects from residues when used in applications such as cosmetics. In particular, they are useful as solvents when wet atomizing polyhydroxyalkanoate resins. In addition, 3-alkoxy-3-methyl-1-butanol and / or 3-alkoxy-3-methyl-1-butyl acetate dissolve or plasticize polyhydroxyalkanoate resins at high temperatures, for example, 110°C or higher, but do not dissolve polyhydroxyalkanoate resins at room temperature (25°C), making it industrially advantageous as the alcohol-based solvent can be easily reused. Furthermore, by using 3-alkoxy-3-methyl-1-butanol and 3-alkoxy-3-methyl-1-butyl acetate (both with 1 to 5 carbon atoms in the alkoxy group) as alcohol-based solvents, the oil absorption properties of polyhydroxyalkanoate resin particles can be improved.

[0042] {dispersion stabilizer} In the method for producing polyhydroxyalkanoate resin particles of the present invention, the dispersion stabilizer used in the emulsification and dispersion step is not particularly limited. Any agent that functions as a dispersion stabilizer when the polyhydroxyalkanoate resin is emulsified and dispersed by heating and stirring in the presence of at least one alcohol-based solvent and water, for example, by heating and stirring at 110°C to 180°C, is acceptable. For example, the surface may be treated with a silane coupling agent or a non-animal surface treatment agent. Among these, poorly water-soluble inorganic compound particles are preferred as the dispersion stabilizer.

[0043] Poorly water-soluble inorganic compounds are substances with a solubility in water of less than 2.0 g / L, preferably less than 1.0 g / L, more preferably less than 100 mg / L, and even more preferably less than 50 mg / L. Examples include one or more selected from the group consisting of calcium carbonate, barium carbonate, magnesium carbonate, silica, alumina, titanium dioxide, calcium sulfate, barium sulfate, magnesium sulfate, tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium pyrophosphate, magnesium pyrophosphate, aluminum pyrophosphate, zinc pyrophosphate, calcium metasilicate, etc. Of these, carbonates, particularly calcium carbonate, are preferred because they are easy to remove after use.

[0044] The surface treatment agent used to treat the surface of poorly water-soluble inorganic compounds is not particularly limited as long as it can impart hydrophobicity. Examples include oils such as hydrocarbon oils, ester oils, and lanolin; silicones such as dimethylpolysiloxane, methylhydrogenpolysiloxane, and methylphenylpolysiloxane; fluorine compounds such as perfluoroalkyl group-containing esters, perfluoroalkyl silanes, perfluoropolyethers, and polymers having perfluoroalkyl groups; silane coupling agents such as 3-methacryloxypropyltrimethoxysilane and 3-glycidoxypropyltrimethoxysilane; titanium coupling agents such as isopropyltriisostearoyl titanate and isopropyltris(dioctyl pyrophosphate) titanate; metal soaps; fatty acids; amino acids such as acyl glutamic acid; and lecithins such as hydrogenated egg yolk lecithin. In particular, calcium carbonate surface-treated with silane coupling agents or non-animal surface treatment agents is preferred because it has high affinity with polyhydroxyalkanoate resins, excellent dispersion stability, and allows for easy control of the particle size of the polyhydroxyalkanoate resin particles.

[0045] The particle size of the poorly water-soluble inorganic compound particles is not particularly limited, but a small primary particle size is preferred in order to increase the specific surface area. The average primary particle size of the poorly water-soluble inorganic compound particles is, for example, 10 nm or more, for example, 1000 nm or less, preferably 500 nm or less, and more preferably 200 nm or less.

[0046] The amount of organic solvent used in the emulsification and dispersion process is, from the viewpoint of ensuring sufficient stirring and mixing and productivity, for example, 5 parts by mass or more, for example, 1200 parts by mass or less, preferably 800 parts by mass or less, and more preferably 500 parts by mass or less, per 100 parts by mass of polyhydroxyalkanoate resin particles. The amount of dispersion stabilizer used in the emulsification and dispersion process is, from the viewpoint of ensuring sufficient stirring and mixing and productivity, for example, 5% by mass or more, for example, 50% by mass or less, preferably 40% by mass or less, and more preferably 35% by mass or less, relative to the polyhydroxyalkanoate resin particles. In addition, various surfactants can be used in combination with the dispersion stabilizer, which is a poorly water-soluble inorganic compound. For example, the amount of surfactant added can be 0.01 to 0.5 parts by mass per 100 parts by mass of water.

[0047] When heating and stirring polyhydroxyalkanoate resin particles, stirring can be performed by means of liquid-phase stirring with stirring blades, mixing with a homogenizer, or mixing with ultrasonic irradiation. The stirring speed and time are not particularly limited, as long as the conditions are such that the polyhydroxyalkanoate resin is uniformly dispersed in the solvent.

[0048] (cooling / particulation process) The method for cooling the polyhydroxyalkanoate resin dispersion is not particularly limited. In the present invention, it is preferable to cool it slowly from the heating temperature to the cooling temperature, for example, at a cooling rate of 0.5°C / min to 5.0°C / min. It is also preferable to perform the cooling while stirring. The stirring rate can be within the same range as the stirring rate during heating. The cooling temperature is not particularly limited, but for example, it is between 5°C and 45°C. This makes it possible to obtain a polyhydroxyalkanoate resin particle dispersion in which a dispersion stabilizer (such as a poorly water-soluble inorganic compound) is coated on the surface.

[0049] (Dispersion stabilizer removal process / Powdering process) The polyhydroxyalkanoate resin particle dispersion obtained by cooling, in which the surface is coated with a dispersion stabilizer (a poorly water-soluble inorganic compound), is separated from the solvent by filtration, washing, dehydration, and drying, and then classified as necessary to obtain the polyhydroxyalkanoate resin particles of the present invention. To obtain polyhydroxyalkanoate resin particles whose surface is not coated with a dispersion stabilizer (poorly water-soluble inorganic compound), a step of removing the dispersion stabilizer (poorly water-soluble inorganic compound) using an acid that decomposes and dissolves it can be added before filtration. When decomposing and dissolving the dispersion stabilizer, from the viewpoint of suppressing hydrolysis of the polyhydroxyalkanoate resin and preventing a decrease in spreadability on the skin when added to topical preparations, it is preferable to add an acid that is not a strong acid, for example, 1.05 to 1.50 times, more preferably 1.05 to 1.20 times, the required number of moles of acid, stir at 40°C or below, and filter and wash within 24 hours, more preferably within 12 hours. Subsequently, the polyhydroxyalkanoate-based resin particles of the present invention can be obtained by drying using a vacuum drying method or a spray drying method.

[0050] The dried polyhydroxyalkanoate resin particles may be classified as needed. Classification methods include wind classification, airflow classification, and screen classification. Classification is preferably carried out in an air atmosphere with a relative humidity of 30% or less, preferably 20% or less, so that the polyhydroxyalkanoate resin particles do not absorb moisture from the air. The obtained polyhydroxyalkanoate resin particles are preferably sealed in a moisture-impermeable packaging material and stored as a packaged product to prevent them from absorbing moisture from the air.

[0051] [Topical preparations] The topical preparation of the present invention contains polyhydroxyalkanoate resin particles of the present invention. The type of topical preparation is not particularly limited. Examples include makeup cosmetics such as face powders, face powders (loose powder, pressed powder, etc.), foundations (powder foundations, liquid foundations, emulsion foundations, etc.), lipsticks, lip balms, blushes, eyebrow cosmetics, and nail polish; cleansing cosmetics such as soaps, body shampoos, facial cleansing creams, scrub cleansers, and toothpaste; lotions such as pre-shave lotions and body lotions; topical body preparations such as body powders and baby powders; skincare cosmetics such as lotions, creams, and emulsions (cosmetic emulsions); sunscreens, suntan products, antiperspirants (liquid antiperspirants, solid antiperspirants, cream antiperspirants, etc.), face masks, hair washing cosmetics, hair dyes, hair styling products, fragrance cosmetics, bath additives, and shaving creams. In particular, cosmetics are preferred, and makeup cosmetics, cleansing cosmetics, and skincare cosmetics are more preferred, from the viewpoint of taking advantage of the low odor and biodegradability in water properties of polyhydroxyalkanoate resin particles.

[0052] When the topical preparation of the present invention is a cosmetic composition, the content of polyhydroxyalkanoate resin particles can be appropriately adjusted depending on the type of cosmetic composition. For example, it is 0.1% by mass or more, preferably 0.5% by mass or more, more preferably 1% by mass or more, and from the viewpoint of improving production cost, stability, and feel, it is, for example, 50% by mass or less, preferably 30% by mass or less, more preferably 25% by mass or less.

[0053] The topical preparation of the present invention may contain commonly used main ingredients or additives as needed, as long as they do not impair the effects of the present invention. Examples of such main ingredients or additives include one or more selected from the group consisting of water, lower alcohols (alcohols with 5 or fewer carbon atoms), oils and waxes, hydrocarbons, higher fatty acids, higher alcohols, sterols, fatty acid esters, metal soaps, humectants, surfactants, polymer compounds, colorant raw materials, fragrances, clay minerals, preservatives and bactericides, anti-inflammatory agents, antioxidants, ultraviolet absorbers, organic-inorganic composite particles, pH adjusters (such as triethanolamine), specially formulated additives, pharmaceutical active ingredients, and the like.

[0054] Examples of oils and waxes include one or more selected from the group consisting of avocado oil, almond oil, olive oil, cocoa butter, beef tallow, sesame oil, wheat germ oil, safflower oil, shea butter, turtle oil, camellia oil, peach oil, castor oil, grape oil, macadamia nut oil, mink oil, egg yolk oil, Japanese wax, coconut oil, rosehip oil, hydrogenated oil, silicone oil, orange roughy oil, carnauba wax, candelilla wax, whale wax, jojoba oil, montan wax, beeswax, lanolin, etc. Examples of hydrocarbons include one or more selected from the group consisting of liquid paraffin, petrolatum, paraffin, ceresin, microcrystalline wax, squalane, etc. Specific examples of higher fatty acids include one or more fatty acids with 11 or more carbon atoms, such as lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, behenic acid, undecylenic acid, oxystearic acid, linoleic acid, lanolinic acid, and synthetic fatty acids. Specific examples of higher alcohols include one or more alcohols selected from the group consisting of alcohols with 6 or more carbon atoms, such as lauryl alcohol, cetyl alcohol, cetostearyl alcohol, stearyl alcohol, oleyl alcohol, behenyl alcohol, lanolin alcohol, hydrogenated lanolin alcohol, hexyldecanol, octyldecanol, isostearyl alcohol, jojoba alcohol, and decyltetradecanol. Specific examples of sterols include one or more selected from the group consisting of cholesterol, dihydrocholesterol, phytocholesterol, etc.

[0055] Examples of fatty acid esters include linoleic acid esters such as ethyl linoleate; lanolin fatty acid esters such as isopropyl lanolinate; lauric acid esters such as hexyl laurate; myristic acid esters such as isopropyl myristate, myristyl myristate, cetyl myristate, octyldodecyl myristate; oleic acid esters such as decyl oleate, octyldodecyl oleate; dimethyloctanoic acid esters such as hexyldecyl dimethyloctanoate; isooctanoic acid esters such as cetyl isooctanoate (cetyl 2-ethylhexanoate); ethylhexyl isononanoate, isono One or more selected from the group consisting of: isononanoate esters such as isononyl isonanoate and isotridecyl isononanoate; palmitate esters such as isopropyl palmitate, ethylhexyl palmitate and decyl palmitate; glycerin trimyristate, tri(caprylic / capric acid)glycerin, propylene glycol dioleate, glyceryl triisostearate, glyceryl triisooctanoate, cetyl lactate, myristyl lactate, diisostearyl malate, cholesteryl isostearate, cholesteryl 12-hydroxystearate, etc.

[0056] The oils used as greases and oils, waxes, hydrocarbons, higher fatty acids, higher alcohols, sterols, fatty acid ester oils, etc., are preferably non-volatile oils, more preferably non-volatile oils with a viscosity of 550 mPa·s or less at 20°C, even more preferably non-volatile oils with a viscosity of 1 to 550 mPa·s, and particularly preferably non-volatile oils with a viscosity of 5 to 550 mPa·s. When such non-volatile oils are combined with the polyhydroxyalkanoate resin particles of the present invention, they blend well with the oil, the particles can be applied uniformly, and effects such as a smooth and bright finish after application, excellent adhesion to the skin, light spreadability on the skin, and excellent stability over time can be obtained. Non-volatile oils with a viscosity of 550 mPa·s or less at 20°C include one or more selected from the group consisting of liquid paraffin, squalane, olive oil, castor oil, jojoba oil, mink oil, macadamia nut oil, hexyl laurate, isopropyl myristate, octyldodecyl myristate, cetyl isooctanoate (cetyl 2-ethylhexanoate), ethylhexyl isononanoate, isononyl isononanoate, isotridecyl isononanoate, isopropyl palmitate, ethylhexyl palmitate, decyl palmitate, tri(caprylic / capric acid)glycerin, glyceryl triisostearate, glyceryl triisooctanoate, etc. The content of the above non-volatile oil in the cosmetic composition of the present invention is preferably 1 to 20% by mass from the viewpoint of exhibiting the above effects. In this specification, non-volatile oil means an oil that remains on the skin for at least several hours at room temperature (23°C) and atmospheric pressure, and in particular has a vapor pressure of less than 0.13 Pa (0.01 mmHg).

[0057] Examples of metal soaps include one or more selected from the group consisting of zinc laurate, zinc myristate, magnesium myristate, zinc palmitate, zinc stearate, aluminum stearate, calcium stearate, magnesium stearate, zinc undecylenate, etc. Examples of humectants include one or more selected from the group consisting of glycerin, propylene glycol, 1,3-butylene glycol, polyethylene glycol, dl-pyrrolidone carboxylate sodium, sodium lactate, sorbitol, sodium hyaluronate, polyglycerin, xylitol, maltitol, etc.

[0058] Examples of surfactants include one or more selected from the group consisting of: anionic surfactants such as higher fatty acid soaps, higher alcohol sulfates, N-acyl glutamates, and phosphate ester salts; cationic surfactants such as amine salts and quaternary ammonium salts; amphoteric surfactants such as betaine type, amino acid type, imidazoline type, and lecithin; and nonionic surfactants such as fatty acid monoglycerides, polyethylene glycol, propylene glycol fatty acid esters, sorbitan fatty acid esters, sucrose fatty acid esters, polyglycerin fatty acid esters, and ethylene oxide condensates.

[0059] Examples of polymer compounds include natural polymer compounds such as gum arabic, tragacanth gum, guar gum, locust bean gum, karaya gum, iris moss, quince seed, gelatin, shellac, rosin, and casein; semi-synthetic polymer compounds such as sodium carboxymethylcellulose, hydroxyethylcellulose, methylcellulose, ethylcellulose, sodium alginate, ester gum, nitrocellulose, hydroxypropylcellulose, and crystalline cellulose; and synthetic polymer compounds such as polyvinyl alcohol, polyvinylpyrrolidone, sodium polyacrylate, carboxyvinyl polymer, polyvinyl methyl ether, polyamide resin, silicone oil, nylon particles, poly(meth)acrylic acid ester particles (e.g., polymethyl methacrylate particles), polystyrene particles, silicone-based particles, urethane particles, polyethylene particles, silica particles, and other resin particles; and one or more selected from the group.

[0060] Examples of colorants include one or more selected from the group consisting of inorganic pigments such as iron oxide (red iron oxide, yellow iron oxide, black iron oxide, etc.), ultramarine, conch, chromium oxide, chromium hydroxide, carbon black, manganese violet, titanium dioxide, zinc oxide, talc, kaolin, calcium carbonate, magnesium carbonate, mica, aluminum silicate, barium silicate, calcium silicate, magnesium silicate, silica, zeolite, barium sulfate, calcined calcium sulfate (calcined gypsum), calcium phosphate, hydroxyapatite, and ceramic powder; and tar dyes such as azo, nitro, nitroso, xanthene, quinoline, anthraquinoline, indigo, triphenylmethane, phthalocyanine, and pyrene.

[0061] Powdered raw materials such as resin particles and colorant raw materials can be used even if they have been pre-surface-treated. As for surface treatment methods, known surface treatment techniques can be used, and examples include one or more treatment methods selected from the group consisting of: oil treatment with hydrocarbon oils, ester oils, lanolin, etc.; silicone treatment with dimethylpolysiloxane, methylhydrogenpolysiloxane, methylphenylpolysiloxane, etc.; fluorine compound treatment with perfluoroalkyl group-containing esters, perfluoroalkyl silanes, perfluoropolyethers, and polymers having perfluoroalkyl groups; silane coupling agent treatment with 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, etc.; titanium coupling agent treatment with isopropyltriisostearoyl titanate, isopropyltris(dioctyl pyrophosphate) titanate, etc.; metal soap treatment; amino acid treatment with acyl glutamic acid, etc.; lecithin treatment with hydrogenated egg yolk lecithin, etc.; collagen treatment; polyethylene treatment; moisturizing treatment; inorganic compound treatment; mechanochemical treatment, etc.

[0062] Examples of fragrances include one or more selected from the group consisting of anisaldehyde, benzyl acetate, geraniol, etc. Examples of clay minerals include one or more selected from the group consisting of components that possess several functions such as extender pigments and adsorbents, such as talc, mica, sericite, titanium sericite (sericite coated with titanium dioxide), muscovite, and VEEGUM® manufactured by Vanderbilt. Examples of preservatives and disinfectants include one or more selected from the group consisting of methylparaben, ethylparaben, propylparaben, benzalkonium, benzethonium, etc. Examples of antioxidants include one or more selected from the group consisting of dibutylhydroxytoluene, butylhydroxyanisole, propyl gallate, tocopherol, and the like. Examples of UV absorbers include one or more selected from the group consisting of inorganic absorbers such as fine-particle titanium dioxide, fine-particle zinc oxide, fine-particle cerium oxide, fine-particle iron oxide, and fine-particle zirconium oxide; and organic absorbers such as benzoic acid-based, para-aminobenzoic acid-based, anthranic acid-based, salicylic acid-based, cinnamic acid-based, benzophenone-based, and dibenzoylmethane-based absorbers.

[0063] Examples of specially formulated additives include one or more selected from the group consisting of: hormones such as estradiol, estrone, ethinylestradiol, cortisone, hydrocortisone, and prednisone; vitamins such as vitamin A, vitamin B, vitamin C, and vitamin E; skin astringents such as citric acid, tartaric acid, lactic acid, aluminum chloride, aluminum potassium sulfate, allantoin chlorohydroxyaluminum, zinc paraphenolsulfonate, and zinc sulfate; hair growth stimulants such as cantharis tincture, capsicum tincture, ginger tincture, swertia japonica extract, garlic extract, hinokitiol, carpronium chloride, pentadecanoic acid glyceride, vitamin E, estrogen, and photosensitizer; and whitening agents such as magnesium L-ascorbate phosphate and kojic acid.

[0064] [Coating materials] The coating material of the present invention contains the polyhydroxyalkanoate resin particles of the present invention. In addition to the polyhydroxyalkanoate resin particles of the present invention, the coating material of the present invention may optionally contain a binder resin, an ultraviolet-curable resin, a solvent, etc. As the binder resin, for example, a resin soluble in organic solvents or water, or an emulsion-type resin that can be dispersed in water can be used.

[0065] In the present invention, the binder resin is not particularly limited. For example, polyhydroxyalkanoate resins (e.g., polylactic acid, polyglycolic acid, polybutylene succinate, polybutylene succinate adipate, polybutylene adipate terephthalate, poly(ethylene succinate terephthalate), poly(butylene succinate terephthalate), poly(butylene adipate terephthalate), poly(3-hydroxybutyrate), poly(3-hydroxyvalate), poly(3-hydroxycaprolate), poly(3-hydroxyheptanoate), poly(3-hydroxyo Examples include biodegradable resins such as ctanoate, poly(3-hydroxybutyrate-3-hydroxyhexanoate), poly(3-hydroxybutyrate-3-hydroxyvalate), poly(ε-caprolactone), poly(β-propiolactone), polyamide 4, starch-based resins, cellulose-based resins, glucosamine-based resins, etc.; and one or more selected from the group consisting of acrylic resins, alkyd resins, polyamide resins, polyester resins, polyurethane resins, chlorinated polyolefin resins, amorphous polyolefin resins, etc.

[0066] In the present invention, examples of UV-curable resins include polyfunctional (meth)acrylate resins such as polyhydric alcohol polyfunctional (meth)acrylates; and polyfunctional urethane acrylate resins synthesized from diisocyanates, polyhydric alcohols, and (meth)acrylic acid esters having hydroxyl groups. Of these, polyfunctional (meth)acrylate resins are preferred, and polyhydric alcohol polyfunctional (meth)acrylate resins having three or more (meth)acryloyl groups in one molecule are more preferred. Polyhydric alcohol polyfunctional (meth)acrylate resins having three or more (meth)acryloyl groups in one molecule include, specifically, one or more selected from the group consisting of trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, 1,2,4-cyclohexanetetra(meth)acrylate, pentagrycerol triacrylate, pentaerythritol tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol triacrylate, dipentaerythritol pentaacrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tripentaerythritol triacrylate, tripentaerythritol hexaacrylate, etc.

[0067] When using UV-curable resins, it is preferable to use a photopolymerization initiator in combination. The photopolymerization initiator is not particularly limited. For example, one or more selected from the group consisting of acetophenone-based, benzoin-based, phosphine oxide-based, ketal-based, α-hydroxyalkylphenone-based, α-aminoalkylphenone-based, anthraquinone-based, thioxanthone-based, azo-based compounds, peroxide-based (as described in Japanese Patent Publication No. 2001-139663, etc.), 2,3-dialkyldione-based, disulfide-based, fluoroamine-based, aromatic sulfonium-based, onium salt-based, borate salt-based, active halogen-based, α-acyloxime ester-based, etc. These binder resins or UV-curable resins can be appropriately selected depending on the adhesion of the coating material to the substrate to be painted and the environment in which it is used.

[0068] In the present invention, the content of each of the above components also varies depending on the thickness of the coating film formed, the average particle size of the resin particle group, and the coating method. The amount of resin particle group added in the present invention is preferably 1 to 50% by mass, more preferably 3 to 45% by mass, and even more preferably 5 to 40% by mass, when the total content of the binder resin (solid content in the case of emulsion-type aqueous resin) and the resin particle group of the present invention is 100% by mass.

[0069] In the present invention, the solvent is not particularly limited, but it is preferable to use a solvent that can dissolve or disperse the binder resin or UV-curable resin. For example, in the case of oil-based coating materials (oil-based paints), examples include hydrocarbon solvents such as toluene and xylene; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; ester solvents such as ethyl acetate and butyl acetate; and ether solvents such as dioxane, ethylene glycol diethyl ether, and ethylene glycol monobutyl ether. In the case of water-based coating materials (water-based paints), water, alcohols, etc., can be used. These solvents may be used individually or in mixtures of two or more. The solvent content in the coating material is usually about 20 to 60% by mass of the total amount of coating material. One or more of these solvents can also be used as diluents to adjust the viscosity of the coating material, if necessary.

[0070] In the present invention, the coating material may optionally contain known surface modifiers, flow modifiers, ultraviolet absorbers, light stabilizers, curing catalysts, extender pigments, coloring pigments, metal pigments, mica powder pigments, dyes, etc.

[0071] In the present invention, the method for forming a coating film using a coating material is not particularly limited, and any known method can be used. For example, methods such as spray coating, roll coating, brush coating, inkjet coating, bar coating, and dipping are available, and for coating a substrate such as a film as a thin layer, methods such as reverse roll coating, gravure coating, die coating, and comma coating can be used. Furthermore, a cross-linked coating can be formed by applying the coating to any coated surface such as a substrate to create a coating film, drying this coating film, and then curing the coating film as needed.

[0072] The coating material is used to form a coating film by coating various substrates. The substrate is not particularly limited and can be, for example, metal, wood, glass, ceramics, plastics, etc. In the present invention, it can also be used by coating transparent substrates such as polyethylene terephthalate (PET), polycarbonate (PC), and acrylic.

[0073] [Resin composition] The resin composition of the present invention contains the polyhydroxyalkanoate resin particles of the present invention. The resin composition of the present invention contains a base resin in addition to the polyhydroxyalkanoate resin particles of the present invention.

[0074] In the present invention, the base resin is not particularly limited. For example, polyhydroxyalkanoate resins (e.g., polylactic acid, polyglycolic acid, polybutylene succinate, polybutylene succinate adipate, polybutylene adipate terephthalate, poly(ethylene succinate terephthalate), poly(butylene succinate terephthalate), poly(butylene adipate terephthalate), poly(3-hydroxybutyrate), poly(3-hydroxyvalate), poly(3-hydroxyvalate), poly(3-hydroxyalate) Biodegradable resins such as poly(hydroxycaprolate), poly(3-hydroxyheptanoate), poly(3-hydroxyoctanoate), poly(3-hydroxybutyrate·3-hydroxyhexanoate), poly(3-hydroxybutyrate·3-hydroxyvalate), poly(ε-caprolactone), poly(β-propiolactone), polyamide 4, starch-based resins, cellulose-based resins, glucosamine-based resins, etc.; polycarbonate, poly One or more resins selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate, polyamide 6, polyamide 66, polyamide 12, ABS resin (acrylonitrile-butadiene-styrene copolymer resin), AS resin (acrylonitrile-styrene copolymer resin), polyethylene, polypropylene, polyacetal, polyamide-imide, polyethersulfone, polyimide, polyphenylene oxide, polyphenylene sulfide, polystyrene, thermoplastic polyurethane elastomer, thermoplastic polyester elastomer, thermoplastic polyamide elastomer, polyvinyl chloride, polyvinylidene fluoride, ethylene tetrafluoroethylene copolymer (ETFE resin), tetrafluoroethylene perfluoroalkyl vinyl ether copolymer (PFA resin), polyether ketone, and other thermoplastic resins; epoxy resins, urethane resins, and other thermosetting resins; etc.

[0075] In the present invention, the content of the polyhydroxyalkanoate resin particles of the present invention in the resin composition also varies depending on the thickness of the molded article formed, the average particle size of the polyhydroxyalkanoate resin particles, and the molding method. The content of the polyhydroxyalkanoate resin particles of the present invention is preferably 0.1 to 70% by mass, more preferably 0.5 to 50% by mass, and even more preferably 1 to 30% by mass, when the total content of the base resin and the polyhydroxyalkanoate resin particles of the present invention is taken as 100% by mass.

[0076] In the present invention, the resin composition may contain known additives as needed. Examples of additives include reinforcing fibers such as glass fibers and carbon fibers, flame retardants, flow modifiers, ultraviolet absorbers, heat stabilizers, light stabilizers, lubricants, extender pigments, coloring pigments, metallic pigments, dyes, and the like.

[0077] In the present invention, the method for producing the resin composition is not particularly limited, and it can be produced by mixing a group of resin particles and a base resin using a conventionally known method such as a mechanical grinding and mixing method. In the mechanical grinding and mixing method, for example, the resin composition can be produced by mixing and stirring the group of resin particles and the base resin using equipment such as a Henschel mixer, a V-type mixer, a Turbra mixer, a hybridizer, or a rocking mixer.

[0078] In the present invention, the method for forming molded articles using the resin composition is not particularly limited, and any known method can be used. For example, by mixing the resin particle group of the present invention with a base resin in a mixer and kneading it in a melt kneader such as an extruder to obtain pellets made of the resin composition, and then molding these pellets by extrusion, injection, blow molding, etc., molded articles of any shape suitable for automotive materials, building materials, packaging materials, etc. can be obtained.

[0079] [Blocking prevention agent] The blocking inhibitor of the present invention contains polyhydroxyalkanoate resin particles of the present invention. In addition to the polyhydroxyalkanoate resin particles of the present invention, the blocking inhibitor may optionally contain known antioxidants, flow modifiers, light stabilizers, coloring pigments, etc. The content of the polyhydroxyalkanoate resin particles of the present invention in the blocking inhibitor of the present invention is preferably 70 to 100% by mass, more preferably 80 to 100% by mass, and even more preferably 90 to 100% by mass.

[0080] The anti-blocking agent of the present invention is used to create an uneven surface on a resin film in order to prevent the surfaces of resin films from sticking together and becoming stuck to each other (blocking) when the resin film is wound up or the like.

[0081] In the present invention, the resin film on which the anti-blocking agent can be used is not particularly limited. For example, polylactic acid, polyglycolic acid, polybutylene succinate, polybutylene succinate adipate, polybutylene adipate terephthalate, poly(ethylene succinate terephthalate), poly(butylene succinate terephthalate), poly(butylene adipate terephthalate), poly(ε-caprolactone), poly(β-propiolactone), polyamide 4, poly(3-hydroxybutyrate), poly(3-hydroxyvalate), poly(3-hydroxycaprolate), poly(3-hydroxyheptanoate), poly(3-hydroxyoctanoate), poly(3-hydroxybutyrate 3-hydroxyhexanoate), poly(3-hydroxybutyrate 3-hydroxy Examples of films made from one or more resins selected from the group consisting of: biodegradable resins such as varilate, starch-based resins, cellulose-based resins, and glucosamine-based resins; polyester-based resins such as polyethylene terephthalate and polyethylene naphthalate; polyolefin-based resins such as polyethylene-based resins and polypropylene-based resins; (meth)acrylic-based resins; polystyrene-based resins; polyethersulfone-based resins; polyurethane-based resins; polycarbonate-based resins; polysulfone-based resins; polyether-based resins; polymethylpentene-based resins; polyetherketone-based resins; (meth)acrylonitrile-based resins; norbornene-based resins; amorphous polyolefin-based resins; polyamide-based resins; polyimide-based resins; triacetylcellulose-based resins; etc.

[0082] The content of the resin particle group of the present invention in the resin film varies depending on the thickness of the film formed, the average particle size of the resin particle group, and the molding method. The content of the resin particle group of the present invention is preferably 0.01 to 10% by mass, more preferably 0.01 to 5% by mass, even more preferably 0.01 to 3% by mass, and particularly preferably 0.01 to 1% by mass in the resin film. [Examples]

[0083] The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited thereto. Unless otherwise specified, "%" means "mass%".

[0084] [Measurement method etc.] <Residual amount of unsaturated fatty acids> The quantitative analysis of residual unsaturated fatty acids was performed as follows. (1) Method of pretreatment before extraction Approximately 1 g of polyhydroxyalkanoate resin particles were accurately weighed into a centrifuge tube, 5 mL of methanol was added and mixed, and sonication was performed for 15 minutes, followed by thorough mixing again. The mixture was centrifuged at 3,500 rpm for 30 minutes, and the supernatant was filtered through a non-aqueous 0.2 μm chromatographic disk 13N (GL Sciences) to obtain the test solution. The test solution was then measured using UHPLC.

[0085] (2)Measurement method The conditions for UHPLC measurement of the test solution were as follows. Unsaturated fatty acids were quantified using standard peak area values ​​obtained from chromatograms using standard solutions. A calibration curve created with the Shimadzu LabSolutions chromatograph workstation was used for quantification. The concentration of each unsaturated fatty acid in the test solution was determined from this calibration curve, and the content of each unsaturated fatty acid (residual amount of unsaturated fatty acids) was calculated from the obtained results. Unsaturated fatty acid content (mg / kg) = Measured value (μg / mL) × Methanol extraction volume (mL) ÷ Sample mass (g)

[0086] (3) UHPLC measurement conditions ·Amount of unsaturated fatty acids <uhplc> Instrument: Shimadzu Corporation "NexeraX2" ultrahigh-speed liquid chromatography column: Kinetex 1.7μm C18 100A (2.1mm I.D. × 50mm L) Column temperature: 40℃ Pump temperature: Room temperature (23℃) Mobile phase: (A: 0.05% trifluoroacetic acid (TFA) / B: acetonitrile) Mobile phase conditions: (0→0.5min=B conc. 90%, 0.5 → 0.51min = B conc. 90% → 80%, 0.51 → 2min = B conc. 80%, 2→2.5min=B conc. 80% → 20%, 2.5 → 3 min = B conc. 20%, 3→3.5min=B conc. 20% → 90%, 3.5 → 5 min = B conc. 90%) Flow rate: 0.6mL / min Measurement time: 5 min Injection volume: 1μL Detector: PDA = 210 nm (crotonic acid, 2-pentenoic acid), 200 nm (4-pentenoic acid)

[0087] • Method for preparing standard solutions Using the automatic dilution function of the autosampler of the Shimadzu NexeraX2 ultrahigh-speed liquid chromatograph, a 1,000 mg / L standard solution was diluted 10 times with methanol to prepare a 100 mg / L standard solution, and a 20-fold dilution with methanol to prepare a 50 mg / L standard solution. Furthermore, a 100 mg / L standard solution was diluted 5 times to prepare a 20 mg / L standard solution. A 50 mg / L standard solution was diluted 5 times to prepare a 10 mg / L standard solution. A 20 mg / L standard solution was diluted 5 times to prepare a 4 mg / L standard solution. A 10 mg / L standard solution was diluted 10 times to prepare a 1 mg / L standard solution. A 1 mg / L standard solution was diluted 5 times to prepare a 0.2 mg / L standard solution. 4-pentenoic acid was also measured using the following method.

[0088] • 4-pentenoic acid amount (1) Method of pretreatment before extraction Approximately 1 g of polyhydroxyalkanoate resin particles were weighed and immersed in 10 mL of acetone for 30 minutes of sonication extraction. 1 mL of the extract (supernatant) was taken into a measurement vial, 0.5 mL of bis(trimethylsilyl)trifluoroacetamide (BSTFA) was added, and the mixture was gently shaken. After standing for at least 1 hour to allow derivatization (trimethylsilylation), the mixture was measured by gas chromatography-mass spectrometry (GC-MS).

[0089] (2)Measurement method The conditions for GC-MS measurement of the test solution were as follows. Unsaturated fatty acids were quantified using standard peak area values ​​obtained from chromatograms using standard solutions. A calibration curve prepared with standard solutions was used for quantification. The concentration of each unsaturated fatty acid in the test solution was determined from this calibration curve, and the content of each unsaturated fatty acid (residual amount of unsaturated fatty acids) was calculated from the obtained results. 4-pentenoic acid amount (μg / g) = 4-pentenoic acid concentration of test solution (μg / mL) × extraction volume (mL) ÷ sample mass (g)

[0090] (3)GC-MS measurement conditions Equipment: Agilent Technologies 7890A GC / 5975C MSD System Column: Agilent J&W DB-5ms, 30m x 0.25mm i.d., film thickness 0.25μm Inlet temperature: 250℃ Carrier gas: Helium 1 ml / min Split ratio: 10:1 Oven temperature: 50°C (1 min) - 10°C / min - 300°C (5 min) Injection volume: 1μL Ionization method: Electron impact ionization method (EI method: 70 eV) Measurement mode: Selected Ion Monitoring (SIM) mode Monitor ion: Quantitative ion m / z 157 (4-pentenoate TMS)

[0091] • Method for preparing standard solutions 0.1 g of 4-pentenoic acid was placed in a 10 mL volumetric flask and diluted to a standard stock solution of 1000 μg / mL with acetone. This stock solution was then diluted with acetone to prepare standard solutions of 500, 100, 50, 10, 5, 1, and 0.5 μg / mL. Derivatization was performed in the same manner as with the sample extract.

[0092] <Volume-average particle size> The volume-average particle size of polyhydroxyalkanoate resin particles was measured using a particle size distribution analyzer (Beckman Coulter, "Multisizer 4e"). The measurement was performed by selecting an aperture calibrated according to the user's manual, appropriate to the size of the particles being measured. For the measurement sample, 0.1 g of polyhydroxyalkanoate resin particles were dispersed in 10 ml of a 0.1% by mass nonionic surfactant aqueous solution using a touch mixer (Yamato Scientific Co., Ltd., "TOUCHMIXER MT-31") and an ultrasonic cleaner (Velvo-Clear Co., Ltd., "ULTRASONIC CLEANER VS-150") to obtain the dispersion. During the measurement, the contents of the beaker were gently stirred to prevent air bubbles from entering. 100,000 polyhydroxyalkanoate resin particles were measured, and the particle size of each polyhydroxyalkanoate resin particle was determined. The volume-average particle size of polyhydroxyalkanoate resin particles is the arithmetic mean of the volume-based particle size distribution of 100,000 particles.

[0093] <Moisture content> The moisture content of polyhydroxyalkanoate resin particles was measured using the Karl Fischer method as follows: A 0.4g sample of polyalkanoate resin particles was placed in a Mitsubishi Chemical Analytec "CA-200" Karl Fischer moisture analyzer and "VA-236S" moisture vaporizer. Aquamicron AX and Aquamicron CXU, both manufactured by Mitsubishi Chemical, were used as the anode and cathode liquids, respectively. The measurement temperature was 150°C. N2 was used as the carrier gas. The carrier gas flow rate was 250 mL / min. The sample was tested three times. The moisture content of the air alone at the sampling site was measured twice, and the average value was used as the blank value. The blank value was subtracted from each measurement result and divided by the sample mass to determine the moisture content of the sample. The moisture content of the sample was calculated using the following formula. Moisture content = [Measured moisture content (μg) - Blank moisture content (μg)] ÷ 1,000,000 ÷ Sample mass (g) × 100 The moisture content of the sample was determined by averaging the results of three measurements taken using the above measurement method.

[0094] <Average circularity> The average circularity of polyhydroxyalkanoate resin particles was measured using a flow-type particle image analyzer (Sysmex Corporation, "FPIA(registered trademark)-3000S"). The measurements were performed as follows: To 20 ml of deionized water, 0.05 g of sodium alkylbenzenesulfonate was added as a dispersant to obtain an aqueous surfactant solution. To the obtained aqueous surfactant solution, 0.02 g of polyhydroxyalkanoate resin particles were added, and a dispersion treatment was performed using an ultrasonic cleaner (Velvoclear Co., Ltd., "VS-150") for 2 minutes to disperse the polyhydroxyalkanoate resin particles in the aqueous surfactant solution, thereby obtaining a dispersion for measurement. A particle sheath (Sysmex Corporation, "PSE-900A") was used as the sheath fluid for the flow-type particle image analyzer. The dispersion for measurement was introduced into the flow-type particle image analyzer equipped with a standard objective lens (10x), and measurements were taken under the following conditions: Measurement mode: LPF measurement mode Particle size measurement range: 0.5~200μm Measurement range for particle circularity: 0.2~1.0 Number of particles measured: 100,000

[0095] For the measurement, a suspension of standard polymer particles (THERMO FISHER SCIENTIFIC, "5200A" (standard polystyrene particles diluted with deionized water)) was used, and the automatic focus adjustment of the flow-type particle image analyzer was performed before the start of the measurement. The average circularity was calculated by dividing the perimeter, which was calculated from the diameter of a perfect circle having the same area as the projected area of ​​the polyhydroxyalkanoate resin particles in the image obtained by imaging the measurement dispersion, by the perimeter of the polyhydroxyalkanoate resin particles in the image obtained.

[0096] <color tone> The color tone of the polyhydroxyalkanoate resin particles conforms to JIS Z 8729, L * a * b * The chromaticity was obtained by measuring the chromaticity using a color system. The polyhydroxyalkanoate resin particles are filled to the brim into a measuring container (powder cell) (Konica Minolta Sensing Co., Ltd., "CR-A50"). * value, a * Value and b * The values ​​were measured using a colorimeter (Konica Minolta Sensing, "CR-300").

[0097] [Manufacturing of resin pellets] <Manufacturing Example 1> Poly(3-hydroxybutyrate-co-3-hydroxyvariate) resin raw material powder (Cheonan Biotechnology Co., Ltd., "ENMAT Y1000") was continuously supplied at 15 kg / h to a 26 mm twin-screw extruder (Toshiba Machine Co., Ltd., "TEM-26"). The extruded through a Φ5 × 5 hole strand mold attached to the tip of the extruder, and the strand was cooled and pelletized in a pelletizer to obtain poly(3-hydroxybutyrate-co-3-hydroxyvariate) resin raw material pellets. The resin temperature at the mold outlet was 188°C.

[0098] [Manufacturing of calcium carbonate dispersion] <Manufacturing Example 2> 3,500 g of 5 mm zirconia beads, 100 g of calcium carbonate (Shiraishi Calcium Co., Ltd., "Shiratsuka PZ"; primary particle size: 80 nm), 450 g of deionized water, and 450 g of 3-methoxy-3-methyl-1-butanol (Kuraray Co., Ltd., "Solfit Fine Grade") were added to a 2 L quartz glass pot mill, and the mixture was treated at a peripheral speed of 100 rpm for 24 hours on a ball mill rotating stand to obtain a calcium carbonate dispersion.

[0099] [Examples and Comparative Examples] <Example 1> A 57mm twin-screw extruder (manufactured by Osaka Seiki Co., Ltd., L / D=31.6) was continuously supplied with poly(3-hydroxybutyrate-co-3-hydroxyvalaryrate) resin raw material pellets obtained in Production Example 1 at a rate of 7.5 kg / h. A 15% aqueous solution of partially saponified polyvinyl alcohol (Mitsubishi Chemical Corporation's "Gosenol GL-05") was continuously injected at a rate of 10.7 kg / h through an inlet located in the cylinder section of the third block from the input section. A slurry in which poly(3-hydroxybutyrate-co-3-hydroxyvalaryrate) resin particles were dispersed in the partially saponified polyvinyl alcohol aqueous solution was continuously obtained from a Φ7 rod mold attached to the tip of the extruder. The cylinder temperatures of the extruder were as follows: 100°C in the raw material pellet input section, 200°C in the two resin melting zones, 220°C in the two emulsification zones including the polyvinyl alcohol aqueous solution injection section, 200°C in the two rear emulsification zones, 120°C in the three cooling zones, and 170°C in the front mold section. The obtained slurry was washed with 60°C water using a small centrifugal dehydrator and then dehydrated. The resulting cake of poly(3-hydroxybutyrate-co-3-hydroxyvariate) resin particles was dried in an 80°C oven for 24 hours, crushed in a mixer, and further classified using a 25 μm mesh to remove coarse particles, thereby obtaining poly(3-hydroxybutyrate-co-3-hydroxyvariate) resin particles. The obtained poly(3-hydroxybutyrate-co-3-hydroxyvalate) resin particles showed no detectable residual crotonic acid, residual 2-pentenoic acid, or residual 4-pentenoic acid, confirming that the total residual amount of unsaturated fatty acids was 10 ppm by mass or less. Furthermore, the volume-average particle size was 11.2 μm, the moisture content was 0.28% by mass, and the average roundness was 0.91. * The value is 93.0, a * The value is -0.7, b * The value was +4.3.

[0100] <Example 2> In a 2L autoclave equipped with a stirring blade and thermometer, 104g of poly(3-hydroxybutyrate-co-3-hydroxyvalate) resin raw material powder (manufactured by Cheonan Biotechnology, "ENMAT Y1000"), 432.2g of 3-methoxy-3-methyl-1-butanol as a solvent, 432.2g of deionized water, 31.2g of triacetin (manufactured by Daihachi Chemical Industry Co., Ltd.), and 156g of the calcium carbonate dispersion obtained in Production Example 2 as a dispersion stabilizer were added. The mixture was heated while stirring at 600 rpm until the internal temperature reached 150°C, and after reaching 150°C, it was emulsified for 90 minutes. Then, while maintaining a stirring speed of 600 rpm, it was cooled to 30°C over 1 hour to obtain a suspension. To the resulting suspension, 76 ml of 20% hydrochloric acid (1.14 times the required number of moles) was added and stirred for 10 minutes to decompose the calcium carbonate. Then, poly(3-hydroxybutyrate-co-3-hydroxyvalrate) resin particles were separated using a centrifuge (manufactured by Tanabe Willtec Co., Ltd.). The separated poly(3-hydroxybutyrate-co-3-hydroxyvalate) resin particles were washed with ion-exchanged water in an amount 20 times the amount of resin added. The washed poly(3-hydroxybutyrate-co-3-hydroxyvalate) resin particles were dried for 20 hours under conditions of 60°C and a vacuum of 0.05 MPa. Dry poly(3-hydroxybutyrate-co-3-hydroxyvariate) resin particles were classified using a classifier (Toyo High-Tech Co., Ltd., "High Volter NR300") equipped with a screen with a mesh size of 45 μm, under an air atmosphere with a relative humidity of 20%. The classification was performed by flowing the poly(3-hydroxybutyrate-co-3-hydroxyvariate) resin particles in an airflow with a relative humidity of 20%, causing the airflow to collide with the screen and removing particles with a particle size that does not pass through the screen mesh. The obtained poly(3-hydroxybutyrate-co-3-hydroxyvalate) resin particles showed no detectable residual crotonic acid, residual 2-pentenoic acid, or residual 4-pentenoic acid, confirming that the total residual amount of unsaturated fatty acids was 10 ppm by mass or less. Furthermore, the volume-average particle size was 18.9 μm, the moisture content was 0.38% by mass, and the average roundness was 0.87. * The value is 96.3, a * The value is -0.8, b * The value was +2.0.

[0101] <Example 3> A 57mm twin-screw extruder (manufactured by Osaka Seiki Co., Ltd., L / D=31.6) was continuously supplied with poly(3-hydroxybutyrate-co-3-hydroxyvariate) resin raw material pellets obtained in Production Example 1 at a rate of 7.5 kg / h. A 7% aqueous solution of partially saponified polyvinyl alcohol (Mitsubishi Chemical Corporation's "Gosenol GH-20R") was continuously injected at a rate of 10.7 kg / h through an inlet located in the cylinder section of the third block from the input section. A slurry in which poly(3-hydroxybutyrate-co-3-hydroxyvariate) resin particles were dispersed in the partially saponified polyvinyl alcohol aqueous solution was continuously obtained from a Φ30 rod mold attached to the tip of the extruder. The cylinder temperatures of the extruder were as follows: 100°C in the raw material pellet input section, 220°C in the two resin melting zones, 220°C in the two emulsification zones including the polyvinyl alcohol aqueous solution injection section, 200°C in the two rear emulsification zones, 160°C in the three cooling zones, and 160°C in the front mold section. From the obtained slurry, poly(3-hydroxybutyrate-co-3-hydroxyvalate) resin particles were separated using a centrifuge (manufactured by Tanabe Willtec Co., Ltd.). The separated poly(3-hydroxybutyrate-co-3-hydroxyvalate) resin particles were washed with ion-exchanged water at 60°C in an amount 20 times the amount of resin. The washed poly(3-hydroxybutyrate-co-3-hydroxyvalate) resin particles were dried for 20 hours under conditions of 80°C and a vacuum of 0.05 MPa. After drying, poly(3-hydroxybutyrate-co-3-hydroxyvalarylate) resin particles were crushed in a chopper mill and then classified using a classifier (Toyo High-Tech Co., Ltd., "Highvolter NR300") equipped with a 45 μm mesh screen, under an air atmosphere with a relative humidity of 20%. The classification was performed by flowing the poly(3-hydroxybutyrate-co-3-hydroxyvalarylate) resin particles in an airflow with a relative humidity of 20%, causing the airflow to collide with the screen and removing particles with a particle size that does not pass through the screen mesh. The obtained poly(3-hydroxybutyrate-co-3-hydroxyvalate) resin particles showed no detectable residual crotonic acid, residual 2-pentenoic acid, or residual 4-pentenoic acid, confirming that the total residual amount of unsaturated fatty acids was 10 ppm by mass or less. Furthermore, the volume-average particle size was 6.8 μm, the moisture content was 0.43% by mass, and the average roundness was 0.92. * The value is 92.7, a * The value is -0.4, b * The value was +3.4.

[0102] <Example 4> In Example 2, resin particles were obtained in the same manner as in Example 2, except that the amount of triacetin was changed to 20.8 g. The obtained poly(3-hydroxybutyrate-co-3-hydroxyvalate) resin particles showed no detectable residual crotonic acid, residual 2-pentenoic acid, or residual 4-pentenoic acid, confirming that the total residual amount of unsaturated fatty acids was 10 ppm by mass or less. Furthermore, the volume-average particle diameter was 32.2 μm, the water content was 0.31% by mass, and the average roundness was 0.89. * The value is 94.9, a * The value is -0.7, b * The value was +2.9.

[0103] [Preparation of topical preparations] A mixture was prepared by mixing 15 parts by mass of poly(3-hydroxybutyrate-co-3-hydroxyvalate) resin particles from Example 2, 21 parts by mass of sericite, 51 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 using a Henschel mixer. On the other hand, a solution was prepared by mixing and dissolving 10 parts by mass of cetyl 2-ethylhexanoate with 1 part by mass of sorbitan sesquioleate and 0.2 parts by mass of a preservative. After uniformly mixing the aforementioned mixture and the aforementioned dissolved substance, 0.1 parts by mass of fragrance was added and uniformly mixed, then the mixture was pulverized and passed through a sieve to produce a foundation material. This foundation material was compressed and molded into a metal tray to produce a powder foundation. The powder foundation (topical preparation) containing poly(3-hydroxybutyrate-co-3-hydroxyvalarrate) resin particles of Example 2 was found to be odorless, free from any squeaking, and possessed excellent feel during application (feel when applied to the skin), as well as superior adhesion to the skin and a light, smooth spread on the skin.

[0104] [Preparation of coating materials] Two parts by mass of poly(3-hydroxybutyrate-co-3-hydroxyvalate) resin particles from Example 1 and 20 parts by mass of a commercially available acrylic water-based gloss paint (manufactured by Kanpe Papio Co., Ltd., product name Super Hit) were mixed for 3 minutes using a stirring and degassing device, and then degassed for 1 minute to obtain a coating material. The obtained coating was applied to an ABS resin (acrylonitrile-butadiene-styrene resin) plate using a coating device equipped with a blade with a clearance of 50 μm, and then dried to obtain a coating film. The obtained coating film was measured using a gloss meter (HORIBA, "GLOSS CHECKER IG-330"). The gloss (60°) of the coating film was 1.

[0105] The present invention can be implemented in various other forms without departing from its spirit or main features. Therefore, the embodiments described above are merely illustrative in all respects and should not be constrained. The scope of the invention is defined by the claims, and the text of the specification is not restrictive. Furthermore, any modifications or changes within the equivalent scope of the claims are all within the scope of the invention.< / uhplc>

Claims

1. Polyhydroxyalkanoate resin particles having a total residual amount of unsaturated fatty acids of 10 ppm by mass or less, an average circularity of 0.8 or more and 1.0 or less, and a volume-average particle diameter, which is the arithmetic mean of the volume-based particle size distribution of 100,000 polyhydroxyalkanoate resin particles, of 3 μm or more and 40 μm or less.

2. Polyhydroxyalkanoate resin particles having a total residual amount of crotonic acid of 10 ppm by mass or less, an average circularity of 0.8 or more and 1.0 or less, and a volume-average particle diameter, which is the arithmetic mean of the volume-based particle size distribution of 100,000 polyhydroxyalkanoate resin particles, of 3 μm or more and 40 μm or less.

3. Polyhydroxyalkanoate resin particles having a total residual amount of pentenoic acid of 60 ppm by mass or less, an average circularity of 0.8 or more and 1.0 or less, and a volume-average particle diameter, which is the arithmetic mean of the volume-based particle size distribution of 100,000 polyhydroxyalkanoate resin particles, of 3 μm or more and 40 μm or less.

4. Polyhydroxyalkanoate resin particles according to any one of claims 1 to 3, wherein the polyhydroxyalkanoate resin comprises a poly(3-hydroxybutyrate-co-3-hydroxyvaliate) resin.

5. Polyhydroxyalkanoate resin particles according to any one of claims 1 to 3, wherein the moisture content is 0.2% by mass or more and 0.8% by mass or less.

6. A topical preparation comprising resin particles according to any one of claims 1 to 3.

7. A coating material comprising polyhydroxyalkanoate resin particles according to any one of claims 1 to 3.

8. A resin composition comprising polyhydroxyalkanoate resin particles according to any one of claims 1 to 3.

9. An antiblocking agent comprising polyhydroxyalkanoate resin particles according to any one of claims 1 to 3.