Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/02—Cosmetics or similar toiletry preparations characterised by special physical form
  • A61K8/0204—Specific forms not provided for by any of groups A61K8/0208 - A61K8/14
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L101/00—Compositions of unspecified macromolecular compounds
  • C08L101/16—Compositions of unspecified macromolecular compounds the macromolecular compounds being biodegradable
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/02—Cosmetics or similar toiletry preparations characterised by special physical form
  • A61K8/0241—Containing particulates characterized by their shape and/or structure
  • A61K8/0254—Platelets; Flakes
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
  • A61K8/72—Cosmetics or similar toiletry preparations characterised by the composition containing organic macromolecular compounds
  • A61K8/73—Polysaccharides
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
  • A61K8/72—Cosmetics or similar toiletry preparations characterised by the composition containing organic macromolecular compounds
  • A61K8/73—Polysaccharides
  • A61K8/731—Cellulose; Quaternized cellulose derivatives
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
  • A61K8/72—Cosmetics or similar toiletry preparations characterised by the composition containing organic macromolecular compounds
  • A61K8/73—Polysaccharides
  • A61K8/732—Starch; Amylose; Amylopectin; Derivatives thereof
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
  • A61K8/72—Cosmetics or similar toiletry preparations characterised by the composition containing organic macromolecular compounds
  • A61K8/84—Cosmetics or similar toiletry preparations characterised by the composition containing organic macromolecular compounds obtained by reactions otherwise than those involving only carbon-carbon unsaturated bonds
  • A61K8/85—Polyesters
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61Q—SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
  • A61Q1/00—Make-up preparations; Body powders; Preparations for removing make-up
  • A61Q1/02—Preparations containing skin colorants, e.g. pigments
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61Q—SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
  • A61Q1/00—Make-up preparations; Body powders; Preparations for removing make-up
  • A61Q1/02—Preparations containing skin colorants, e.g. pigments
  • A61Q1/10—Preparations containing skin colorants, e.g. pigments for eyes, e.g. eyeliner, mascara
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61Q—SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
  • A61Q1/00—Make-up preparations; Body powders; Preparations for removing make-up
  • A61Q1/12—Face or body powders for grooming, adorning or absorbing
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61Q—SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
  • A61Q17/00—Barrier preparations; Preparations brought into direct contact with the skin for affording protection against external influences, e.g. sunlight, X-rays or other harmful rays, corrosive materials, bacteria or insect stings
  • A61Q17/04—Topical preparations for affording protection against sunlight or other radiation; Topical sun tanning preparations
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61Q—SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
  • A61Q19/00—Preparations for care of the skin
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J3/00—Processes of treating or compounding macromolecular substances
  • C08J3/12—Powdering or granulating
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J3/00—Processes of treating or compounding macromolecular substances
  • C08J3/18—Plasticising macromolecular compounds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L1/00—Compositions of cellulose, modified cellulose or cellulose derivatives
  • C08L1/08—Cellulose derivatives
  • C08L1/10—Esters of organic acids, i.e. acylates
  • C08L1/12—Cellulose acetate
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K2800/00—Properties of cosmetic compositions or active ingredients thereof or formulation aids used therein and process related aspects
  • A61K2800/40—Chemical, physico-chemical or functional or structural properties of particular ingredients
  • A61K2800/41—Particular ingredients further characterized by their size
  • A61K2800/412—Microsized, i.e. having sizes between 0.1 and 100 microns
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2329/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an alcohol, ether, aldehydo, ketonic, acetal, or ketal radical; Hydrolysed polymers of esters of unsaturated alcohols with saturated carboxylic acids; Derivatives of such polymer
  • C08J2329/02—Homopolymers or copolymers of unsaturated alcohols
  • C08J2329/04—Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2401/00—Characterised by the use of cellulose, modified cellulose or cellulose derivatives
  • C08J2401/08—Cellulose derivatives
  • C08J2401/10—Esters of organic acids
  • C08J2401/12—Cellulose acetate

Definitions

• the present disclosure relates to flat particles, a method for producing the same, and a cosmetic composition using the flat particles.
• various fine particles have been blended into cosmetics for the purpose of improving the spreadability of the cosmetics, changing the texture, imparting a wrinkle-blurring effect, and improving the slipperiness of foundations and the like. Furthermore, depending on the shape and physical properties of the fine particles, a light scattering (soft focus) effect can be obtained. In particular, when flat-shaped fine particles are used in foundations, etc., they can improve optical functions, such as preventing dullness of the makeup film and giving it transparency, and hiding wrinkles and unevenness in the skin to make the skin even. It will be done.
• inorganic substances such as mica flakes, sericite, and talc are used as materials for the flat particles incorporated in such cosmetics.
• Flat particles made of these inorganic substances are sometimes used after surface treatment, but there are problems in that they are poor in slipperiness on the skin and poor tactile sensation.
• fine particles made of synthetic polymers such as polyamide, polymethyl methacrylate, polystyrene, polypropylene, polyethylene, etc. have a superior feel to the touch compared to inorganic fine particles.
• synthetic polymers such as polyamide, polymethyl methacrylate, polystyrene, polypropylene, polyethylene, etc.
• Patent Document 1 JP-A No. 2011-127124 discloses flat cellulose particles having an average particle diameter of 1 to 100 ⁇ m, an average thickness of 0.01 to 5 ⁇ m, and an oblateness of 20 to 200. . These flat cellulose particles are manufactured by mechanically pulverizing a mixture containing a cellulosic material.
• the flat cellulose particles disclosed in Patent Document 1 are mechanically pulverized. Mechanical crushing impairs the surface smoothness of the resulting particles. When these flat cellulose particles are used, for example, in a foundation or the like, there is a possibility that a sufficient tactile sensation cannot be obtained due to the surface shape of the particles.
• An object of the present disclosure is to provide biodegradable flat particles that have a good tactile feel and improved soft focus properties, and a method for producing the same.
• the biodegradable flat particles according to the present disclosure contain a biodegradable polymer as a main component. These biodegradable flat particles have flatness D/T, which is the ratio of average length L ( ⁇ m) to average thickness T ( ⁇ m), of 2.0 or more, and surface smoothness of 80% or more.
• the biodegradable flat particles may have an aspect ratio L/S, which is the ratio of the average major axis L ( ⁇ m) to the average minor axis S ( ⁇ m), of 2.0 or more.
• the biodegradable polymer is selected from the group consisting of polysaccharides, polysaccharide esters and aliphatic polyesters.
• the polysaccharide may be one or two selected from cellulose and starch.
• the polysaccharide ester may have a total degree of substitution of more than 0 and 3.0 or less.
• the polysaccharide ester may be cellulose acylate having an acyl group having 2 or more and 10 or less carbon atoms.
• the aliphatic polyester may be a polyhydroxyalkanoic acid or a polymer of an aliphatic dicarboxylic acid and an aliphatic diol.
• the aliphatic polyester may be one or more selected from the group consisting of polycaprolactone, polyhydroxybutyric acid, and polylactic acid.
• the cosmetic composition of the present disclosure includes any of the biodegradable flat particles described above.
• the method for producing biodegradable flat particles of the present disclosure includes: (1) Mixing a biodegradable polymer, a plasticizer, and a water-soluble polymer to obtain a mixture; (2) Melting and kneading the mixture at 200°C or higher and 280°C or lower to obtain a kneaded product; (3) pressurizing the kneaded material at a temperature below the melting point of the water-soluble polymer; and (4) removing the water-soluble polymer from the kneaded material after pressurization.
• the kneaded material may be pressurized at a temperature of 150°C or higher and 200°C or lower. Further, in this manufacturing method, the kneaded material may be pressurized at a pressure of 500 MPa or more.
• biodegradable flat particles that have a good tactile feel and improved optical properties such as soft focus, and a cosmetic composition using the biodegradable flat particles.
• FIG. 1 is a scanning electron microscope (SEM) image (magnification: 5000 times) of flat particles of Example A-1.
• FIG. 2 is a scanning electron microscope (SEM) image (magnification: 5000 times) of particles of Comparative Example A-1.
• the biodegradable flat particles are particles whose main component is a biodegradable polymer.
• the flat particles have a flatness L/T, which is the ratio of the average length L ( ⁇ m) to the average thickness T ( ⁇ m), of 2.0 or more, and a surface smoothness of 80% or more.
• the term "main component” means that the most abundant component among the constituent components of the particles is a biodegradable polymer, and the content thereof is at least 50% by weight.
• biodegradable polymer means a polymer that is decomposed in soil, seawater, or in vivo.
• a "polymer” is defined as a compound formed by repeatedly bonding one or more constituent units. It may be a synthetic polymer or a naturally-derived polymer, as long as it exhibits a predetermined biodegradability.
• the flat particles of the present disclosure are made of a biodegradable material, and have excellent soft focus properties and good tactile sensation due to their shape.
• the flat particles of the present disclosure can be incorporated into various cosmetic compositions. By blending these flat particles, it is possible to obtain a cosmetic composition with low environmental impact and high quality.
• the flat particles of the present disclosure have a flatness L/T, which is the ratio of the average length L ( ⁇ m) to the average thickness T ( ⁇ m), of 2.0 or more.
• the "longer diameter” of a flat particle is defined as the maximum diameter on a projection plane obtained by projecting onto a two-dimensional plane so that the area of the particle is maximized.
• the length of the long side of the smallest rectangle circumscribing the projection plane of this particle is the "longer axis" of the present disclosure.
• “thickness” is defined as the length in the direction perpendicular to the projection plane obtained by projecting onto a two-dimensional plane so that the area of the particle is maximized.
• Flat particles with an oblateness of 2.0 or more exhibit high optical effects due to their particle shape. According to these flat particles, it is possible to obtain a cosmetic composition with particularly improved soft focus properties. From the viewpoint of improving optical effects, the flatness of the flat particles may be 3.0 or more, 5.0 or more, or 7.5 or more. The flatness of the flat particles may be 30 or less, 25 or less, or 20 or less, from the viewpoint of having little effect on the tactile sensation and being easy to incorporate into cosmetic compositions. .
• the term "tactile sensation” is a concept that includes not only the tactile sensation when directly touching the flat particles, but also the texture and tactile sensation when the flat particles are blended into a cosmetic composition, for example.
• the flatness of flat particles is determined by taking a scanning electron micrograph of the particles, measuring the major axis and thickness of a plurality of particles, and determining the ratio of the average major axis L ( ⁇ m) to the average thickness T ( ⁇ m). It can be obtained by calculating L/T. Details of the measurement method will be described later in Examples.
• the surface smoothness of the flat particles of the present disclosure is 80% or more, preferably 85% or more, more preferably 90% or more, even more preferably 95% or more, and the upper limit is 100%. If the surface smoothness is less than 80%, the desired tactile sensation may not be obtained. From the viewpoint of easily obtaining a good tactile sensation, the surface smoothness of the flat particles may be 80 to 100%, may be 85 to 100%, may be 90 to 100%, and may be 95 to 100%. It may be %.
• the surface smoothness of flat particles can be determined based on the area of the recesses by taking a scanning electron micrograph of the particles and observing the irregularities on the surface of the particles. Details of the method for measuring surface smoothness will be described later in Examples.
• the shape of the flat particles of the present disclosure is not particularly limited as long as it has the flatness and surface smoothness described above, but from the viewpoint of easily obtaining the desired tactile sensation and optical properties, the shape is rounded. It is preferable that the shape is formed by a curved line with a sharp angle, and that there are few or almost no sharp edges. Examples of the shape of such flat particles include a flat ellipsoid shape or a substantially ellipsoid shape.
• the flat particle of the present disclosure has two flat surfaces having a contour line formed by a curve, and a side surface located between the two flat surfaces.
• the flat grains of the present disclosure differ from conventional tabular grains and scaly grains in that the side surfaces are substantially smooth curved surfaces that smoothly continue from the flat surface.
• the flat particles of the present disclosure have an aspect ratio L/S, which is the ratio of the average major axis L ( ⁇ m) to the average minor axis S ( ⁇ m), of 2.0 or more. Often, it may be 2.2 or more, and it may be 2.5 or more. From the viewpoint of not inhibiting the tactile sensation, this aspect ratio may be 10 or less.
• L/S is the ratio of the average major axis L ( ⁇ m) to the average minor axis S ( ⁇ m)
• this aspect ratio may be 10 or less.
• the "longer axis" of the flat particle is as described above, and the "breadth axis" is the circumscribed plane of the projection obtained by projecting it onto a two-dimensional plane so that the area of this particle is maximized. Defined as the length of the short side of the smallest rectangle.
• the aspect ratio of flat grains is determined by taking a scanning electron micrograph of the particles, measuring the major axis and minor axis of a plurality of particles, and calculating the average major axis L ( ⁇ m) with respect to the average minor axis S ( ⁇ m). It can be determined by calculating the ratio L/S. Details of the measurement method will be described later in Examples.
• the average major axis of the flat particles of the present disclosure may be 0.5 ⁇ m or more, 1.0 ⁇ m or more, 2.0 ⁇ m or more, and 100 ⁇ m or less, 80 ⁇ m or less.
• the thickness may be 60 ⁇ m or less. If the average major axis exceeds 100 ⁇ m, the feel may be poor. Flat particles with an average particle diameter of less than 0.5 ⁇ m are difficult to manufacture.
• the average minor axis of the flat particles of the present disclosure may be 0.1 ⁇ m or more, 0.5 ⁇ m or more, 1.0 ⁇ m or more, and 50 ⁇ m or less, 40 ⁇ m or less.
• the thickness may be 30 ⁇ m or less. If the average minor axis exceeds 50 ⁇ m, the feel may be poor.
• Flat particles having an average minor axis of less than 0.1 ⁇ m are difficult to manufacture.
• the average thickness of the flat particles of the present disclosure may be 0.05 ⁇ m or more, 0.1 ⁇ m or more, 0.2 ⁇ m or more, and 5.0 ⁇ m or less; 4. It may be 0 ⁇ m or less, and may be 3.0 ⁇ m or less. When the average thickness exceeds 3.0 ⁇ m, it is difficult to obtain the effect of the flat shape. Flat particles with an average thickness of less than 0.05 ⁇ m are difficult to manufacture.
• the main component of the flat particles in the present disclosure may be a biodegradable polymer selected from the group consisting of polysaccharides, polysaccharide esters, and aliphatic polyesters.
• the flat particles may further contain a biodegradable polymer such as an aliphatic polyol, an aliphatic polycarbonate, or a polyacid anhydride, within the range in which the effects of the present disclosure can be obtained.
• Polysaccharide means a polymer compound formed by monosaccharides bonded through glycosidic bonds.
• the polysaccharide may be a polymer of ⁇ -glucose or a polymer of ⁇ -glucose. Examples include cellulose, hemicellulose, pullulan, amylose, agarose, chitin, chitosan, carrageenan, pectin, dextrin, starch, collagen, mannan, arabinogalactan, glycogen, inulin, hyaluronic acid, and modified products thereof. Two or more types of polysaccharides may be used in combination. One or two polysaccharides selected from cellulose and starch are preferred.
• a polysaccharide ester is a carboxylic acid ester of the aforementioned polysaccharide, and is defined as a compound in which a portion of the hydroxyl groups in the molecular chain are substituted with acyl groups. Preference is given to esters of one or two polysaccharides selected from cellulose and starch. Two or more types of polysaccharide esters may be used in combination. Carboxylic acid esters of other polysaccharides not specified herein may be used as long as the effects of the present disclosure can be obtained.
• the total degree of substitution of the polysaccharide ester used in the flat particles of the present disclosure is appropriately selected within a range of more than 0 and 3.0 or less, depending on the type of polysaccharide and the type of substituent.
• the total degree of substitution of the polysaccharide ester may be 0.3 or more, 0.5 or more, 0.7 or more, 1.0 or more, 1.2 or more. It may also be less than or equal to 2.95, less than or equal to 2.80, or less than or equal to 2.65.
• the total degree of substitution of the polysaccharide ester can be measured by known methods using 13 C-NMR or 1 H-NMR.
• preferred polysaccharide esters are cellulose esters, and cellulose acylates having acyl groups having 2 or more carbon atoms are more preferred.
• the number of carbon atoms in the acyl group that cellulose acylate has may be 3 or more, 4 or more, 10 or less, or 8 or less.
• Cellulose acylate may have two or more types of acyl groups as substituents. In the present disclosure, two or more types of cellulose acylates having different numbers of carbon atoms in acyl groups and different degrees of substitution may be used together as a biodegradable polymer.
• cellulose acylate in the present disclosure examples include cellulose acetate, cellulose propionate, cellulose butyrate, cellulose acetate propionate, cellulose acetate butyrate, and the like. From the viewpoint of biodegradability and easy availability, cellulose acetate, cellulose acetate propionate, and cellulose acetate butyrate are preferred.
• the total degree of substitution of cellulose acylate may be 3.0 or less, 2.95 or less, 2.80 or less, 2. It may be 65 or less. From the viewpoint of easily obtaining the desired shape, the total degree of substitution of cellulose acylate may exceed 0, may be 0.3 or more, may be 0.5 or more, and may be 0.7 or more. may be 1.0 or more, 1.20 or more, 1.50 or more, 2.10 or more.
• the degree of substitution of cellulose acylate can be measured by the following method. For example, it can be measured by NMR method according to the method of Tezuka (Tezuka, Carbonydr. Res. 273, 83 (1995)). That is, free hydroxyl groups of cellulose acylate are acylated with a carboxylic acid anhydride in pyridine.
• the type of carboxylic acid anhydride used here should be selected depending on the purpose of analysis. For example, when analyzing the degree of propionyl substitution of cellulose propionate, acetic anhydride is preferable.
• the obtained sample is dissolved in deuterated chloroform, and the 13 C-NMR spectrum is measured.
• the signal of the carbonyl carbon of the propionyl group is high in the region of 172 ppm to 174 ppm. They appear in the same order in the 2nd, 3rd, and 6th positions from the magnetic field.
• the carbonyl carbon signal of the acyl group that cellulose acylate originally has and the acyl group introduced by the carboxylic anhydride treatment The sum of the areas of the carbonyl signals in the cellulose ester is normalized to 3.0, and the abundance ratio of each acyl group at the corresponding position (in other words, the area ratio of each signal) is determined.
• the degree of acyl substitution at the 3-, 3-, and 6-positions can be adjusted.
• the acyl group-containing substituents that can be analyzed by this method are only substituents that do not correspond to the carboxylic anhydride used in the treatment for the purpose of analysis.
• analysis can also be performed by 1 H-NMR.
• the weight average molecular weight of cellulose acylate is not particularly limited as long as the effects of the present disclosure can be obtained. From the viewpoint of easily obtaining a desired shape, the weight average molecular weight of cellulose acylate is preferably 10,000 or more, more preferably 20,000 or more, and even more preferably 30,000 or more. From the viewpoint of high biodegradability and easy obtaining of a desired flat shape, the weight average molecular weight of cellulose acylate is preferably 500,000 or less, more preferably 400,000 or less, and still more preferably 300,000 or less. preferable. The weight average molecular weight of the cellulose ester of cellulose acylate is measured in the same manner as for the aliphatic polyester described above.
• the type of aliphatic polyester is not particularly limited, but from the viewpoint of polymer structure, for example, polyhydroxyalkanoic acid having a repeating unit consisting of a polycondensed structural unit of hydroxyalkanoic acid, and aliphatic dicarboxylic acid and aliphatic diol.
• polyhydroxyalkanoic acid having a repeating unit consisting of a polycondensed structural unit of hydroxyalkanoic acid, and aliphatic dicarboxylic acid and aliphatic diol examples include polymers having as repeating units structural units obtained by dehydration condensation of and.
• polyhydroxyalkanoic acids examples include polyglycolic acid, polylactic acid, poly( ⁇ -hydroxybutyric acid), poly( ⁇ -hydroxyvaleric acid), poly(lactic acid-co-glycolic acid), poly( ⁇ -hydroxybutyric acid-co- Examples include poly( ⁇ -propiolactone), poly( ⁇ -caprolactone), and the like.
• polymers of aliphatic dicarboxylic acids and aliphatic diols include polyethylene succinate, polybutylene succinate, poly(butylene succinate-co-butylene adipate), and the like. Two or more types may be used in combination.
• preferred aliphatic polyesters are one or more selected from the group consisting of polycaprolactone, polyhydroxybutyric acid, and polylactic acid.
• Other aliphatic polyesters not specified herein may be used as long as the effects of the present disclosure can be obtained.
• the weight average molecular weight of the aliphatic polyester is preferably 10,000 or more, more preferably 20,000 or more, and even more preferably 50,000 or more. From the viewpoint of excellent biodegradability, the weight average molecular weight of the aliphatic polyester is preferably 5,000,000 or less, more preferably 1,000,000 or less, even more preferably 500,000 or less, and 250,000 or less. is particularly preferred.
• the weight average molecular weight of the aliphatic polyester is determined by size exclusion chromatography (GPC) measurement using the following equipment and conditions (GPC-light scattering method).
• Temperature 29°C
• Sample concentration 0.25% (wt/vol)
• Injection volume 100 ⁇ l
• MALLS Multi-angle light scattering detector
• DAWN-EOS Multi-angle light scattering detector
• the flat particles may contain a plasticizer.
• a plasticizer refers to a compound that can increase the plasticity of the biodegradable polymer described above.
• the type of plasticizer is not particularly limited, and examples include dimethyl adipate, dibutyl adipate, diisostearyl adipate, diisodecyl adipate, diisononyl adipate, diisobutyl adipate, diisopropyl adipate, and diethylhexyl adipate.
• Examples include polyvalent carboxylic acid esters such as phthalate plasticizers containing phthalate esters such as diethylhexyl, dioctyl phthalate, dibutyl phthalate, and dimethyl phthalate. These polyhydric carboxylic acid esters may be mixed group polybasic acid esters.
• glycerin-based plasticizers including glycerin alkyl esters such as triacetin, diacetin, and monoacetin; neopentyl glycol; trioleyl phosphate, tristearyl phosphate, and tricetyl phosphate;
• phosphoric acid plasticizers containing phosphate esters such as di-2-methoxyethyl phthalate, dibutyl tartrate, 0-benzoyl ethyl benzoate, ethyl phthalyl ethyl glycolate (EPEG), methyl phthalyl ethyl glycolate (MPEG), etc.
• the flat particles may contain one or more plasticizers.
• polyhydric carboxylic acid plasticizers or glycerin plasticizers are preferred, and one or two selected from mixed group polybasic acid esters or glycerin alkyl esters. It is more preferable to use more than one species.
• plasticizers for biodegradable polymers there are products such as "DAIFATTY-10" manufactured by Daihachi Kagaku Kogyo Co., Ltd., "BIOCIZER", “Rikemar PL-004", and "Poem G-" manufactured by Riken Vitamin Co., Ltd. 002'', product names such as ⁇ Polysizer'' and ⁇ Monocizer'' manufactured by DIC Corporation.
• the content of the plasticizer contained in the flat particles is not particularly limited.
• the content of the plasticizer in the flat particles may be more than 0 parts by weight and less than 120 parts by weight, and may be more than 2 parts by weight and less than 100 parts by weight, based on 100 parts by weight of the biodegradable polymer. , may be 10 parts by weight or more and 80 parts by weight or less, and may be 15 parts by weight or more and 50 parts by weight or less.
• the content of plasticizer in the flat particles can be determined by 1 H-NMR measurement.
• part or all of the surface of the flat particles may be coated with inorganic powder.
• the inorganic powder present on the particle surface allows the flat particles to obtain surface properties suitable for solvents and formulations used in cosmetic compositions.
• Flat particles having inorganic powder on their surfaces achieve high particle dispersibility in various solvents and formulations, and improve the texture of the resulting cosmetic composition.
• the inorganic powder and the flat particles may be in a physically attached state or may be in a chemically bonded state.
• the particle shape of the inorganic powder is not particularly limited, and may be, for example, spherical, plate-like, acicular, granular, or irregularly shaped.
• the average particle size of the inorganic powder is preferably smaller than the average particle size of the flat particles, for example, it may be 1/3 or less, and may be 1/10 or less of the average particle size of the flat particles.
• the average particle diameter of the inorganic powder and flat particles means the volume-based median diameter.
• the type of inorganic powder is not particularly limited, but examples include titanium oxide, silicon oxide, aluminum oxide, zinc oxide, zirconium oxide, magnesium oxide, boron nitride, silicon nitride, barium sulfate, calcium sulfate, magnesium sulfate, calcium carbonate, carbonate.
• Examples include magnesium aluminum acid and calcium silicate. Two or more types may be used in combination. One or more selected from the group consisting of titanium oxide, silicon oxide, aluminum oxide, zinc oxide, and zirconium oxide are preferred from the viewpoint of good adhesion to flat particles and good tactile sensation.
• the amount of inorganic powder added to the flat particles is preferably 1.0% by weight or more, more preferably 3.0% by weight or more, and 5% by weight or more. Particularly preferred is .0% by weight or more. From the viewpoint that the physical properties of the flat particles are not impaired, the amount of the inorganic powder added is preferably 50.0% by weight or less, more preferably 30.0% by weight or less, and particularly preferably 10.0% by weight or less. When two or more types of inorganic powders are used together, it is preferable that the total amount thereof satisfies the above range.
• the flat particles of the present disclosure have excellent biodegradability.
• the biodegradation rate measured by a method using activated sludge according to JIS K6950 is preferably 40% by weight or more, more preferably 50% by weight or more, and even more preferably 60% by weight or more within 30 days.
• the flat particles of the present disclosure have good tactile sensation and high optical properties in addition to excellent biodegradability, and therefore can be suitably used in various cosmetic compositions.
• the flat particles of the present disclosure have a flat shape and high surface smoothness, when incorporated into a cosmetic composition, they can fill in and smooth the unevenness of the skin and scatter light in various directions. This creates a soft focus effect that makes wrinkles less noticeable.
• cosmetic compositions containing these flat particles can provide an unprecedentedly good tactile feel.
• Cosmetic compositions include foundations such as liquid foundations and powder foundations; concealers; sunscreens; makeup bases; lipsticks and lipstick bases; powders such as body powders, solid white powders, and face powders; solid powder eye shadows; wrinkle hiding creams. and skin and hair external preparations mainly for cosmetic purposes, such as skin care lotions, and the dosage form thereof is not limited.
• the dosage form may be any of liquids such as aqueous solutions, emulsions, and suspensions; semisolids such as gels and creams; and solids such as powders, granules, and solids.
• emulsion formulations such as creams and milky lotions; oil gel formulations such as lipstick; powder formulations such as foundation; and aerosol formulations such as hair styling agents may also be used.
• Cosmetic compositions containing the flattened particles of the present disclosure, particularly liquid foundations, have excellent spreadability on the skin, coverage of spots and freckles, and slipperiness.
• the flat particles of the present disclosure can be obtained by sequentially performing the following steps. (1) Mixing a biodegradable polymer, a plasticizer, and a water-soluble polymer to obtain a mixture. (2) Melting and kneading the obtained mixture at a temperature of 200°C or higher and 280°C or lower to obtain a kneaded product. (3) Pressing the obtained kneaded product at a temperature below the melting point of the water-soluble polymer; and (4) removing the water-soluble polymer from the kneaded product after pressurization.
• the biodegradable polymer in the production method of the present disclosure is one or more selected from polysaccharides, polysaccharide esters, and aliphatic polyesters.
• the polysaccharides, polysaccharide esters and aliphatic polyesters mentioned above regarding the flat particles are appropriately selected and used.
• Polysaccharides, polysaccharide esters and aliphatic polyesters can be produced by known methods. For example, polysaccharides may be obtained by hydrolyzing polysaccharide esters by known methods. Commercially available biodegradable polymers may be used as long as the effects of the present disclosure can be obtained.
• this cellulose acylate is used in the step of activating the raw material pulp (cellulose); A process of acylating with an acylating agent (acylating agent); a process of deactivating the acylating agent after the acylation reaction; aging (saponification, hydrolysis) of the produced cellulose acylate to achieve the desired total substitution It is obtained through a process of adjusting the temperature.
• a pretreatment step may be performed in which the raw material pulp is disintegrated and crushed, and then acetic acid is sprinkled and mixed.
• the maturing (saponification, hydrolysis) step there may be a post-treatment step of precipitation separation, purification, stabilization, and drying.
• the total degree of substitution of cellulose acylate can be adjusted by adjusting the conditions of the aging process (conditions such as time and temperature).
• the type of substituent can be determined by selecting the esterifying agent. Examples of the substituent include an acetyl group, a propionyl group, a butyryl group, and the like. Depending on the application, two or more types of substituents can be introduced at a desired degree of substitution.
• the plasticizer used in the production method of the present disclosure is not particularly limited as long as it has a plasticizing effect in melt extrusion of biodegradable polymers. It can be appropriately selected depending on the type, physical properties, etc. of the biodegradable polymer used. Specifically, the plasticizers described above as the plasticizers contained in the flat particles can be used alone or in combination of two or more. From the viewpoint of having a high plasticizing effect on biodegradable polymers, polycarboxylic acid plasticizers or glycerin plasticizers are preferred, and one or two selected from mixed group polybasic acid esters or glycerin alkyl esters. The above is more preferable.
• the blending amount of the plasticizer may be more than 0 parts by weight and less than 120 parts by weight, and may be more than 2 parts by weight and less than 100 parts by weight, and more than 10 parts by weight and less than 80 parts by weight, based on 100 parts by weight of the biodegradable polymer.
• the amount may be 15 parts by weight or more and 50 parts by weight or less. If it is too small, the flatness of the obtained flat particles tends to decrease, and if it is too large, the particle shape cannot be maintained, and desired flat particles may not be obtained.
• water-soluble polymer used in the production method of the present disclosure is not particularly limited.
• water-soluble means that when 1 g of polymer is dissolved in 100 g of water at 25° C., the insoluble content is less than 50% by weight.
• the water-soluble polymer has thermoplasticity.
• Thermoplasticity means the property of softening and exhibiting fluidity when heated and solidifying when cooled.
• thermoplastic starch examples include polyvinyl alcohol, polyethylene glycol, sodium polyacrylate, polyvinylpyrrolidone, polypropylene oxide, polyglycerin, polyethylene oxide, polyvinyl acetate, modified starch, thermoplastic starch, methylcellulose, ethylcellulose, hydroxyethylcellulose, and hydroxypropyl cellulose.
• thermoplastic starch can be obtained by a known method. For example, with reference to Japanese Patent Publication No. 6-6307, WO92/04408, etc., it can be produced by mixing tapioca starch with about 20% glycerin as a plasticizer and then kneading it in a twin-screw extruder.
• the water-soluble polymer is preferably one or more selected from the group consisting of polyvinyl alcohol, sodium polyacrylate, polyvinylpyrrolidone, and thermoplastic starch; More preferably, one or more selected from the group consisting of:
• the weight average molecular weight of polyvinyl alcohol is preferably 500 or more and 50,000 or less.
• the blending amount of the water-soluble polymer is preferably 110 parts by weight or more and 15,000 parts by weight or less, more preferably 180 parts by weight or more and 1,200 parts by weight or less, and 200 parts by weight or more and 800 parts by weight, based on 100 parts by weight of the biodegradable polymer. The following are more preferred. If the amount is less than 110 parts by weight, the surface smoothness may be low and irregularly shaped particles may be produced. If it exceeds 15,000 parts by weight, the particle diameter of the obtained flat particles may become too small.
• the biodegradable polymer, plasticizer, and water-soluble polymer may be mixed in one step or in multiple steps. Furthermore, the biodegradable polymer, plasticizer, and water-soluble polymer may be mixed by melt-kneading. For example, after mixing or melt-kneading a biodegradable polymer and a plasticizer to obtain a first mixture, a water-soluble polymer may be added to the first mixture and mixed or melt-kneaded. good.
• the mixing of the biodegradable polymer and the plasticizer, or the mixing of the biodegradable polymer, the plasticizer, and the water-soluble polymer can be carried out in a dry or wet manner using a mixer such as a Henschel mixer.
• a mixer such as a Henschel mixer
• the temperature inside the mixer is preferably a temperature at which the biodegradable polymer does not melt or decompose, for example, in a range of 20°C or more and less than 200°C.
• a mixer such as a Henschel mixer under temperature conditions of 20 Melt-kneading may be performed after mixing at a temperature of .degree. C. or more and less than 200.degree.
• melt-kneading may be performed by heating and mixing using an extruder.
• the kneading temperature (cylinder temperature) of the extruder may range from 200°C to 230°C. Even at temperatures within this range, it is possible to plasticize and obtain a uniform kneaded product. If the kneading temperature is too low, the flatness and surface smoothness of the resulting particles may decrease, leading to a decrease in tactile sensation, optical properties, etc. Furthermore, if the kneading temperature is too high, the kneaded material may undergo heat-induced deterioration, coloring, etc. Furthermore, since the viscosity of the melt decreases due to the high kneading temperature, kneading of the resin within the twin-screw extruder may be insufficient.
• the kneading temperature (cylinder temperature) of the twin-screw extruder may be 200°C.
• the kneaded material may be extruded into strands and then cut into pellets.
• the die temperature in this case may be about 220°C.
• a mixture containing a biodegradable polymer, a plasticizer, and a water-soluble polymer is melt-kneaded at a temperature of 200° C. or higher and 280° C. or lower to obtain a kneaded product.
• the aforementioned biodegradable polymer, plasticizer, and water-soluble polymer are mixed by melt-kneading at a temperature of 200°C or higher and 280°C or lower, the kneaded product obtained by mixing may be used as is in the next step. good.
• An extruder such as a twin-screw extruder can be used for melt-kneading the mixture.
• the kneading temperature when using an extruder means the cylinder temperature.
• a kneaded material containing a biodegradable polymer or the like may be extruded into a string shape from a die attached to the tip of the extruder, and then cut into pellets. At this time, the die temperature may be 220°C or more and 300°C or less.
• the kneaded product of the present disclosure is a dispersion in which substantially spherical particles containing a biodegradable polymer and a plasticizer are dispersed in a matrix made of a water-soluble polymer.
• the kneaded material which is the dispersion
• the kneaded material is pressurized at a temperature below the melting point of the water-soluble polymer.
• the matrix made of water-soluble polymer is softened, and an appropriate pressure is applied to the particles containing the biodegradable polymer and plasticizer. Due to this heating and pressurization, the biodegradable polymer containing the plasticizer is also softened and deformed by the pressure applied from the matrix. Thereby, a desired flat shape can be imparted to particles containing a biodegradable polymer and a plasticizer having a desired flatness.
• the matrix becomes completely fluidized, so that deformation due to pressure cannot be controlled, resulting in irregularly shaped particles with reduced surface smoothness.
• the temperature at which the kneaded material is pressurized is appropriately selected depending on the type of biodegradable polymer, plasticizer, and water-soluble polymer, the blending ratio, etc., but from the viewpoint of easy control of the particle shape,
• the temperature at which the pressure is applied may be 150°C or higher, 160°C or higher, 170°C or higher, 230°C or lower, 210°C or lower, or 200°C or lower. It's good.
• the temperature at which the kneaded material is pressurized is preferably 150°C or more and 230°C or less, more preferably 150°C or more and 210°C or less, even more preferably 150°C or more and 200°C or less, even more preferably 160°C or more and 210°C or less, and even more preferably 170°C. It is particularly preferable that the temperature is above 200°C.
• the pressure applied to the kneaded material is appropriately selected depending on the types of biodegradable polymer, plasticizer, and water-soluble polymer, blending ratio, etc., but from the viewpoint of easily obtaining the desired flat shape, the pressure should be 500 MPa or more.
• the pressure may be 700 MPa or more, or 1000 MPa or more.
• the upper limit of the pressure is not particularly limited, the flat particles of the present disclosure can be obtained at a pressure of 2000 MPa or less.
• the method of pressurizing the kneaded material under pressure is not particularly limited, and known devices such as a press machine and a roll press machine can be used.
• the kneaded material contains a biodegradable polymer as a main component, has an flatness of 2.0 or more, and a surface smoothness of 80% or more. Oblate particles are obtained.
• Examples of the method for removing the water-soluble polymer include a method in which the pressurized kneaded product is brought into contact with a good solvent for the water-soluble polymer and the water-soluble polymer is eluted into this solvent.
• this solvent include water; alcohols such as methanol, ethanol, and isopropanol; and mixed solvents thereof.
• the water-soluble polymer is extracted from the pressurized kneaded material by mixing the pressurized kneaded material and a solvent, eluting the water-soluble polymer into the solvent, and then filtering to remove the filtrate. Molecules can be removed.
• the plasticizer may or may not be removed together with the water-soluble polymer. Therefore, the obtained flat particles may or may not contain a plasticizer.
• the mixing ratio of the kneaded material and the solvent should be 0.01% by weight or more and 20% by weight or less of the kneaded material based on the total weight of the kneaded material and the solvent.
• the content is preferably 2% by weight or more and 15% by weight or less, and even more preferably 4% by weight or more and 13% by weight or less. If the amount of the kneaded material is more than 20% by weight, the water-soluble polymer may not be sufficiently removed. Furthermore, it may be difficult to separate a solid component containing flat particles from a liquid component in which a water-soluble polymer is dissolved by operations such as filtration or centrifugation.
• the mixing temperature of the kneaded material and the solvent is preferably 0°C or more and 200°C or less, more preferably 20°C or more and 110°C or less, and 40°C or more and 80°C or less. More preferred. If the temperature is less than 0°C, the water-soluble polymer may be insufficiently dissolved and difficult to remove. Further, at temperatures exceeding 200° C., it may be difficult to obtain a desired particle shape due to deformation or aggregation of the particles.
• the mixing time of the kneaded material and the solvent is not particularly limited and may be adjusted as appropriate, but may be, for example, 0.5 hours or more, 1 hour or more, 3 hours or more, 5 hours or more, and 6 hours or less. It may be.
• a stirring device such as an ultrasonic homogenizer or a three-one motor
• the rotation speed when mixing the kneaded material and the solvent may be 5 rpm or more and 3000 rpm or less.
• the water-soluble polymer can be efficiently removed from the kneaded material.
• the plasticizer can also be efficiently removed from the kneaded material.
• inorganic powder is added and mixed with flat particles obtained by removing a water-soluble polymer from a kneaded material after pressurization.
• flat particles obtained by removing a water-soluble polymer from a kneaded material after pressurization.
• flat particles whose surfaces are partially or entirely coated with inorganic powder are obtained. According to these flat particles, the tactile sensation is further improved.
• the inorganic powder is preferably one or more selected from the group consisting of titanium oxide, silicon oxide, aluminum oxide, zinc oxide, and zirconium oxide.
• the amount of the inorganic powder added is preferably 0.01 parts by weight or more and 1.0 parts by weight or less with respect to 100 parts by weight of the biodegradable polymer.
• the method of adding and mixing the inorganic powder to the flat particles obtained by removing the water-soluble polymer there is no particular limitation on the method of adding and mixing the inorganic powder to the flat particles obtained by removing the water-soluble polymer, and known mixing means may be appropriately selected and used. Dry mixing or wet mixing may be used. For example, in the case of dry mixing, a mixing device such as a ball mill, sand mill, bead mill, homogenizer, planetary mixer, film mix, etc. can be used. Furthermore, the order in which the flat particles and the inorganic powder are mixed is not particularly limited. The flat particles and the inorganic powder may be put into the mixing device at the same time, or after putting a predetermined amount of the inorganic powder into the mixing device and stirring (or stirring and pulverizing at the same time), the flat particles are put in and mixed. You may.
• the manufacturing method of the present disclosure may include a step of drying the obtained flat particles after removing the water-soluble polymer and/or after adding and mixing the inorganic powder.
• the drying method is not particularly limited, and known methods such as heat drying, reduced pressure drying, and vacuum drying can be used.
• the drying temperature is preferably room temperature or higher, may be 50°C or higher, and may be 60°C or higher. From the viewpoint of suppressing thermal deterioration, the preferred drying temperature is 120° C. or lower.
• CA cellulose acetate
• triacetin manufactured by Daicel Corporation
• the obtained mixture was supplied to a twin-screw extruder (PCM30 manufactured by Ikegai Co., Ltd., cylinder temperature: 200°C, die temperature: 220°C), and was melt-kneaded and extruded to obtain pellets.
• PCM30 manufactured by Ikegai Co., Ltd., cylinder temperature: 200°C, die temperature: 220°C
• the obtained pellets were blended with 183 parts by weight of polyvinyl alcohol (PVA, produced by Nippon Gosei Chemical Co., Ltd., melting point 190°C, saponification degree 99.1%) as a water-soluble polymer in a dry state.
• PVA polyvinyl alcohol
• a kneaded material containing a biodegradable polymer, a plasticizer, and a water-soluble polymer was obtained by supplying the mixture to a PCM30 manufactured by Ikegai (cylinder temperature: 220° C., die temperature: 220° C.), melt-kneading, and extruding.
• the obtained kneaded product was pressurized at 1000 MPa at 170° C. for 1.0 minutes using a small heat press machine (manufactured by As One Corporation).
• the solution after stirring was filtered through filter paper (No. 5A manufactured by ADVANTEC), and the filtered material was taken out.
• the filtered material was mixed with pure water again, the kneaded material was adjusted to 5% by weight or less, and stirred for 3 hours at a temperature of 80° C. and a rotation speed of 100 rpm. After filtration, the operation of stirring the filtrate in water was repeated three or more times to obtain flat particles of Example A-1.
• the average particle diameter (major axis and minor axis) ( ⁇ m), average thickness ( ⁇ m), and surface smoothness (%) of the obtained flat particles were measured, and the soft focus property, biodegradability, and tactile feel were evaluated.
• the evaluation results are shown in Table 1. Note that the average particle diameter, average thickness, surface smoothness, soft focus property, biodegradability, and tactile sensation were measured or evaluated by the following methods.
• a scanning electron microscope (SEM) image of Example A-1 is shown in FIG. 1 (5000:x magnification). Note that the length of the scale bar in FIG. 1 is 20 ⁇ m.
• ⁇ Average particle diameter (major axis and minor axis) and aspect ratio> Using images of particles observed with a scanning electron microscope (SEM), measure the long axis and short axis of 100 randomly selected particles, calculate the average value of each, and calculate the average long axis L ( ⁇ m) and the average The short axis was defined as S ( ⁇ m). In addition, the length/breadth ratio of each particle was determined, and the average value of the ratio was defined as the aspect ratio L/S. The results obtained are shown in Table 1 below.
• ⁇ Average thickness and flatness> The sample stage on which the sample whose major axis and minor axis were measured was rotated 90 degrees, and a SEM image in the height direction was taken. Using the obtained image, the thickness of 100 randomly selected particles was measured, and the average value was determined to be the average thickness T ( ⁇ m). In addition, the length/thickness ratio of each particle was determined, and the average value of the ratio was defined as the flatness L/T. The results obtained are shown in Table 1 below.
• ⁇ Surface smoothness> Images of particles observed with a scanning electron microscope (SEM) were binarized using an image processing device Winroof (manufactured by Mitani Shoji Co., Ltd.). From the binarized image, a region including the center and/or the vicinity of the center of one particle is randomly selected, and the area ratio of the part corresponding to the concavity and convexity (shaded part) in the region is calculated, and the following The surface smoothness (%) of each particle was calculated using the formula.
• Soft focus property was evaluated using a gloss meter (manufactured by Suga Test Instruments Co., Ltd., model number UGV-6P). Specifically, light was incident on the surface coated with particles at an incident angle of 45 degrees, and the reflection intensity was measured at a light receiving angle of 0 to 85 degrees and a step angle of 5 degrees.
• the ratio B(5)/A was determined by setting the maximum value of the measured value in the obtained reflection intensity distribution as A, and setting the measured value at a light receiving angle of 5 degrees as B(5).
• This ratio B(5)/A is shown in Table 1 below as soft focus property 1. The larger the ratio B(5)/A, the higher the soft focus effect. If the ratio B(5)/A is 0.5 or more, a practically sufficient soft focus property can be obtained.
• Biodegradability was evaluated by biodegradation rate.
• the biodegradation rate was measured by a method using activated sludge according to JIS K6950.
• Activated sludge was obtained from a municipal wastewater treatment plant.
• About 300 mL of a supernatant liquid (activated sludge concentration: about 360 ppm) obtained by leaving the activated sludge for about 1 hour was used per culture bottle.
• Measurement was started at the time when 30 mg of the sample was stirred in the supernatant liquid, and measurements were carried out every 24 hours thereafter, a total of 31 times until 720 hours later, that is, 30 days later.
• the details of the measurement are as follows.
• the biochemical oxygen demand (BOD) in each culture bottle was measured using Coulometer OM3001 manufactured by Okura Electric Co., Ltd.
• the biodegradation rate (wt%) is defined as the percentage of the biochemical oxygen demand (BOD) relative to the theoretical biochemical oxygen demand (BOD) for complete decomposition based on the chemical composition of each sample, and the biodegradation rate (weight %) is Degradability was evaluated.
• ⁇ More than 40% by weight and less than 60% by weight
• ⁇ More than 10% by weight and less than 40% by weight
• ⁇ Less than 10% by weight
• Examples A-2 to A-4 and Comparative Examples A-1 to A-8 Examples A-2 to A were carried out in the same manner as Example A-1, except that the types and amounts of biodegradable polymers, plasticizers, and water-soluble polymers were changed as described in Table 1-2. -4 and Comparative Examples A-1 to A-8 were obtained. In Comparative Examples A-1, A-3, A-5 and A-7, the kneaded material was not pressurized. The results of evaluating the physical properties of each particle using the method described above are shown in Table 1-2. Further, a scanning electron microscope (SEM) image of Comparative Example A-1 is shown in FIG. 2 (magnification: 5000 times). Note that the length of the scale bar in FIG. 2 is 20 ⁇ m.
• SEM scanning electron microscope
• Example A-5 Flat particles of cellulose acetate obtained in the same manner as in Example A-1 were immersed in an aqueous sodium hydroxide solution (concentration 2.7%) and saponified at 80° C. for 4 hours. Thereafter, the filtered flat particles were dried at 80° C. for 12 hours to obtain flat particles of Example A-5. The obtained flat particles were analyzed by 13 C-NMR, and it was confirmed that Example A-5 was a cellulose flat particle.
• CA Cellulose acetate manufactured by Daicel Corporation (total degree of substitution 2.4, weight average molecular weight 47,000)
• PHB Polyhydroxybutyric acid manufactured by Good Fellow (weight average molecular weight 550,000)
• PCL Polycaprolactone manufactured by Daicel Corporation (weight average molecular weight 50,000)
• CAB Cellulose acetate butyrate manufactured by Aldrich (degree of acetyl substitution 0.9, degree of butyryl substitution 1.8, weight average molecular weight 70,000)
• Cellulose completely saponified cellulose acetate CA (total degree of substitution 2.4, weight average molecular weight 47,000) manufactured by Daicel Corporation
• Triacetin manufactured by Daicel Corporation
• DAIFATTY-10 mixed dibase manufactured by Daihachi Kagaku Kogyo Co., Ltd.
• Acid ester PVA Polyvinyl alcohol manufactured by Nippon Gosei Kagaku Co., Ltd. (melting point 190°C, sapon
• the flat particles of Examples are superior in soft focus properties, biodegradability, and tactile sensation compared to particles of Comparative Examples.
• Example B-1 Preparation of Liquid Foundation After mixing each component shown in Table 3, the mixture was thoroughly stirred and filled into a container to prepare a liquid foundation. The texture of the obtained liquid foundation was evaluated by the following method. The results are shown in Table 11.
• composition prepared by blending the particles was subjected to sensory evaluation by a panel test of five people. Each composition was used, and both smoothness and dryness were comprehensively evaluated on a 5-point scale based on the following criteria. The average score of the five people was calculated. Good: 5, Fair: 4, Average: 3, Fair: 2, Bad: 1
• Example B-2 Preparation of sunscreen After mixing each component shown in Table 4, the mixture was thoroughly stirred and filled into a container to prepare a sunscreen. The tactile feel of the obtained sunscreen was evaluated using the method described above. The results are shown in Table 11.
• Example B-3 Preparation of Powder Foundation After roughly mixing component A shown in Table 5, uniformly dissolved component B was added and thoroughly stirred, and the mixture was filled into a container to prepare a powder foundation. The texture of the obtained powder foundation was evaluated using the method described above. The results are shown in Table 11.
• Example B-4 Preparation of makeup base Component C shown in Table 6 was dispersed in component A and stirred well. Thereafter, component B was added, stirred, and filled into a container to prepare a makeup base. The texture of the resulting makeup base was evaluated using the method described above. The results are shown in Table 11.
• Example B-5 Preparation of base material for lipstick Component B shown in Table 7 was heated to 60°C and mixed well. After component C was added and well dispersed, component A was further added and dissolved using a microwave oven, followed by thorough mixing. Thereafter, the mixture was heated and melted again using a microwave oven, poured into a mold, and cooled and solidified. This was placed in a lipstick container to prepare a lipstick base material. The texture of the obtained lipstick base material was evaluated by the method described above. The results are shown in Table 11.
• Example B-6 Preparation of Body Powder Component A shown in Table 8 was thoroughly mixed using a mixer. The obtained powder was filled into a container to prepare a body powder. The texture of the obtained body powder was evaluated by the method described above. The results are shown in Table 11.
• Example B-7 Preparation of Solid White Powder
• the preparation of solid white powder follows the usual manufacturing method of cosmetics. That is, talc and color pigments shown in Table 9 were mixed in a blender. Further, the flat particles (CA particles) of Example A-1 and all the powder parts containing the colored pigment and talc that had been mixed previously in a blender were stirred using a Henschel mixer. Thereafter, an oil component (binder) was added, the mixture was heated to 70° C., and after further stirring, a pulverization step was performed as necessary. This was compression molded into a metal plate container to prepare a solid white powder. The texture of the obtained solid white powder was evaluated by the method described above. The results are shown in Table 11.
• Example B-8 Preparation of Solid Powder Eyeshadow After thoroughly mixing the powders shown in Table 10, the binder was uniformly dissolved, added to the powder portion, and further mixed. Thereafter, a solid powder eye shadow was prepared by compression molding. The tactile sensation of the obtained solid powder eyeshadow was evaluated by the method described above. The results are shown in Table 11.
• PARAFOL 12-97 Sasol
• Isononyl was mixed with coconut oil alkyl caprylate (Cetiol C5 (BASF)), coconut alkyl (caprylic/cap
• a liquid foundation was prepared in the same manner as in Example B-1, except that the macadamia nut fatty acid phytosteryl was changed to camellia oil (pure camellia oil (manufactured by Nikko Spain)).
• camellia oil pure camellia oil (manufactured by Nikko Spain)
• the texture of the obtained liquid foundation was evaluated using the method described above. The results are shown in Table 11.
• a sunscreen was prepared in the same manner as in Example B-2, except that the following was changed. The tactile feel of the obtained sunscreen was evaluated using the method described above. The results are shown in Table 11.
• a powder foundation was prepared in the same manner as in Example B-3, except that the mixture was changed to a mixture containing the same weight of each of the following products. The texture of the obtained powder foundation was evaluated using the method described above. The results are shown in Table 11.
• PARAFOL 12-97 Sasol
• isononyl isononanoate coconut oil alkyl caprylate (Cetiol C5 (manufactured by BASF)), coconut alkyl (caprylic/capric acid) (cetiol C5C (manufactured by BASF)) and dicaprylyl carbonate (Cetiol CC (manufactured by BASF)) were mixed in the same weight.
• a makeup base was prepared in the same manner as in Example B-4 except that
• Example B-13 Mica Y-2300X in Table 5 was used as mica (Mica Y-2300X (manufactured by Yamaguchi Mica)), synthetic mica (PDM-10L (manufactured by Topy Industries, Ltd.)) and (fluorinated/hydroxidized/oxidized)/(Mg/K /silicon) (Micromica MK-200K (manufactured by Katakura Co-op Agri Co., Ltd.)) was changed to a mixture of the same weight.
• Example B-14 Examples except that talc in Table 8 was changed to a mixture of cellulose (NP fiber W-06MG (manufactured by Nippon Paper Industries)) and silica (God Ball E-16C (manufactured by Suzuki Yushi Kogyo Co., Ltd.)) in the same weight.
• a body powder was prepared in the same manner as B-6. The texture of the obtained body powder was evaluated by the method described above. The results are shown in Table 11.
• Example B-15 Mica (Mica Y-2300X (manufactured by Yamaguchi Mica)) in Table 10, mica (Mica Y-2300X (manufactured by Yamaguchi Mica)), synthetic mica (PDM-10L (manufactured by Topy Industries, Ltd.)) and (fluorinated/ Hydroxylation/oxidation)/(Mg/K/Silicon) (Micro Mica MK-200K (manufactured by Katakura Co-op Agri Co., Ltd.)) was changed to a mixture of the same weight.
• a solid powder eye shadow was prepared in the same manner as in Example B-8, except that the mixture was changed to a mixture containing the same weights of boron nitride (SHP-6 (manufactured by Mizushima Alloy Co., Ltd.))) Prepared.
• SHP-6 manufactured by Mizushima Alloy Co., Ltd.
• the tactile sensation of the obtained solid powder eyeshadow was evaluated by the method described above. The results are shown in Table 11.
• Example B-16 A liquid foundation was prepared in the same manner as in Example B-1, except that BG in Table 3 was changed to a mixture of glycerin and pentylene glycol (Diol PD (manufactured by Kyukyu Alcohol Industries)) in the same weight. The texture of the obtained liquid foundation was evaluated using the method described above. The results are shown in Table 11.
• Example B-17 A sunscreen was prepared in the same manner as in Example B-2, except that BG in Table 4 was changed to a mixture of glycerin and pentylene glycol (Diol PD (manufactured by Kyukyu Alcohol Kogyo Co., Ltd.) in the same weights). The tactile feel of the obtained sunscreen was evaluated using the method described above. The results are shown in Table 11.
• Example B-18 Cosmetic preparation was carried out in the same manner as in Example B-4, except that 1,3-butylene glycol in Table 6 was changed to a mixture of glycerin and pentylene glycol (Diol PD (manufactured by Kyukyu Alcohol Kogyo Co., Ltd.)) in the same weight.
• the base was prepared.
• the texture of the resulting makeup base was evaluated using the method described above. The results are shown in Table 11.
• Comparative Examples B-1 to B-8 are the same as the examples, except that the flat particles (CA particles) of Example A-1 in Table 3-10 were changed to the particles (CA particles) of Comparative Example A-1.
• Liquid foundation, sunscreen, powder foundation, makeup base, lipstick base, body powder, solid white powder, and solid powder eye shadow were prepared in the same manner as in B-1 to B-8. The tactile sensation of each was evaluated using the method described above. The results are shown in Table 12.
• the tactile sensations of the cosmetic compositions of Examples B-1 to B-18 containing the flat particles of the present disclosure were all 4.0 or higher, which was excellent, with a particularly smooth tactile sensation. It was something to show.
• both contain flat particles whose main component is a biodegradable polymer excellent biodegradability can be expected.

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