Solid powder cosmetic

Abstract

To provide a solid powder cosmetic that is smooth and is resistant to impact.SOLUTION: The problem is solved by a solid powder cosmetic containing a cellulose powder having an average particle diameter of 1 to 25 μm and an aspect ratio of 0.6 to 0.9, the cellulose powder being an aggregate that contains additives and fine fibrous cellulose having an average fiber width of 1 to 500 nm.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a solid powder cosmetic preparation. [Background technology]

[0002] Conventionally, solid powder cosmetics such as foundation and eye shadow are produced by a press molding method in which the cosmetic composition is filled into a container and compressed to solidify. Because solid powder cosmetics contain a relatively small amount of oil, the bonding force between the powder particles is weak and they do not solidify easily. Therefore, the press pressure is increased when molding, but the molded products produced in this manner have a hard, powdery feel.

[0003] Therefore, in solid powder cosmetics, elastic spherical resin powders such as silicone elastomers and polyurethanes are sometimes used to provide a moist, smooth, and soft feel. However, when a large amount of this resin powder is incorporated, the solid powder cosmetic has the disadvantage of being poor in moldability and easily cracking upon impact. As such, there has been a certain degree of difficulty in producing solid powder cosmetics that combine smoothness and impact resistance.

[0004] In Patent Document 1, the average crushing strength is 0.2 to 1 kg / mm 2 30 to 90% by weight of organic powder consisting of acylated taurine polyvalent metal salt of the above, and an elastic modulus of 1 to 100 kg / cm 2 The above-mentioned difficulties have been resolved by using a film-forming polymer. Patent Document 2 focuses on oil-soluble rice bran extract, which has excellent moisturizing properties, and proposes a powder cosmetic in which oil-soluble rice bran extract is blended in a specific ratio with an oil agent contained in the powder cosmetic. Despite being a powder, this powder cosmetic is smooth and frictionless when applied, and the powder adheres to the skin, leaving the skin with a unique feeling of smoothness and softness after application, while also reducing breakage when dropped. Furthermore, Patent Document 3 proposes a makeup cosmetic containing cellulose granules. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-80325 [Patent Document 2] Patent Publication No. 2021-98674 [Patent Document 3] International Publication No. 2018 / 194050 Summary of the Invention [Problem to be solved by the invention]

[0006] The technologies described in the aforementioned Patent Documents 1 and 2 both focus not on the powder contained in solid powder cosmetics, but on ingredients other than the powder, such as film-forming polymers and oil-soluble rice bran extracts, and by mixing these ingredients, they impart impact resistance and a smooth feel to the solid powder cosmetics. In contrast, the inventors of the present invention have focused on powder, and have been researching powders that can be added to solid powder cosmetics to impart impact resistance and a smooth feel. [Means for solving the problem]

[0007] As a result of extensive research, the inventors have discovered that a solid powder cosmetic containing cellulose powder can solve the above-mentioned problems, and have completed the following aspects of the invention. Note that the cellulose granules described in Cited Document 3 are different from the cellulose powder of the present invention.

[0008] (First aspect) The cellulose powder has an average particle size of 1 to 25 μm and an aspect ratio of 0.6 to 0.9, The cellulose powder is an aggregate containing an additive and fine fibrous cellulose having an average fiber width of 1 to 500 nm. A solid powder cosmetic characterized by:

[0009] The cellulose powder contained in the aforementioned solid powder cosmetic contains fine fibrous cellulose. As the name suggests, fine fibrous cellulose is made up of long, thin fibers, and therefore cellulose powder containing fine fibrous cellulose is not spherical, but rather has a shape that is distorted from a spherical shape. This distorted shape can be expressed, for example, by the aforementioned aspect ratio range. A solid powder cosmetic containing cellulose powder within the aforementioned average particle size and aspect ratio range can combine impact resistance (impact resistance) with a usability that is smooth, moist, and soft to the touch. The reason why solid powder cosmetics containing this cellulose powder can achieve both impact resistance and usability is likely due to the following reasons.

[0010] In order to improve upon the drawbacks of conventional solid powder cosmetics, such as hardness and powdery texture, the incorporation of elastic spherical particles has been investigated. Elastic spherical particles are soft, and the spherical rolling effect gives them a moist feel and smooth spreadability. However, because they undergo elastic deformation during compression molding, when the pressure is released after molding, they exert a force that causes them to return to their original shape, making them difficult to mold and resulting in poor impact resistance after molding.

[0011] In contrast, the cellulose particles used in the present invention undergo plastic deformation when compressed, thereby increasing the contact area between particles, and it is presumed that this improves the moldability and impact resistance of the solid powder cosmetic. Furthermore, even without deformation due to pressure, the cellulose powder used in the present invention includes particles with irregular shapes, has a larger specific surface area than general spherical particles, and because the powder is non-spherical, it is presumed that when mixed with cosmetic ingredients, it will align in random directions, increasing the contact points between the ingredients, and therefore reducing the likelihood of breakage due to external forces that reduce impact resistance.

[0012] Furthermore, when a dispersion of fine fibrous cellulose is dried as is, it becomes particles in which the fibers are strongly and randomly bound together by hydrogen bonds. On the other hand, when a cellulose powder containing fine fibrous cellulose and additives (e.g., hydrophilic water-retaining agents) is dried, the additives moderately inhibit the formation of hydrogen bonds between the cellulose fibers, adding softness, resulting in a moist feel and improving moldability through plastic deformation.

[0013] In addition to the first embodiment, the following embodiment is also preferred.

[0014] (Second aspect) The cellulose powder is formed by agglomeration of the fine fibrous cellulose. A solid powder cosmetic according to a first embodiment.

[0015] (Third aspect) The cellulose powder-containing powder comprises 60 to 99.9% by mass and 0.1 to 40% by mass of an oil content. A solid powder cosmetic according to a first embodiment.

[0016] (Fourth aspect) The additive is glycerin. A solid powder cosmetic according to a first embodiment.

[0017] (Fifth aspect) The cellulose powder has a moisture content of 1 to 15% in an atmosphere with a humidity of 50%. A solid powder cosmetic according to a first embodiment.

[0018] (Sixth aspect) The cellulose powder has a bulk density of 0.5 g / cm 3 Below is the A solid powder cosmetic according to a first embodiment.

[0019] (Seventh aspect) The cellulose powder has a specific surface area of 1.0 m 2 / g or more, A solid powder cosmetic according to a first embodiment.

[0020] (Eighth aspect) The cellulose powder contains 1 to 99% by mass. A solid powder cosmetic according to a first embodiment.

[0021] (Ninth aspect) The cellulose powder has a pulp viscosity of cellulose of 1.0 to 7.0 mPa·s. A solid powder cosmetic according to a first embodiment.

[0022] (Tenth aspect) It is a base makeup cosmetic product. A solid powder cosmetic according to a first embodiment. [Effects of the Invention]

[0023] According to the present invention, a solid powder cosmetic preparation is obtained that is resistant to impact (impact resistance) and smooth. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is an SEM image of cellulose powder A. [Figure 2] 1 is an SEM image of cellulose powder B. [Figure 3] 1 is an SEM image of cellulose powder C. [Figure 4] 1 is an SEM image of cellulose powder D. [Figure 5] 1 is an SEM image of silicone powder. [Figure 6] This is an SEM image of silica powder. DETAILED DESCRIPTION OF THE INVENTION

[0025] Next, an embodiment of the present invention will be described. Note that this embodiment is an example of the present invention. The scope of the present invention is not limited to the scope of this embodiment.

[0026] The solid powder cosmetic of this embodiment contains cellulose powder having an average particle size of 1 to 25 μm and an aspect ratio of 0.6 to 0.9, and is characterized in that the cellulose powder is an aggregate containing additives and fine fibrous cellulose having an average fiber width of 1 to 500 nm. The composition of the solid powder cosmetic is described below.

[0027] (fine fibrous cellulose) The cellulose powder contained in the solid powder cosmetic of this embodiment contains fine fibrous cellulose (also known as "CNF"), which can be obtained by defibrating (refining) raw pulp.

[0028] As the raw material pulp for fine fibrous cellulose, one or more types can be selected from, for example, wood pulp made from hardwoods, softwoods, etc.; non-wood pulp made from straw, bagasse, cotton, hemp, bast fibers, etc.; and deionized paper pulp (DIP) made from recycled waste paper, broke paper, etc.

[0029] However, it is preferable to use wood pulp rather than non-wood pulp or recycled paper pulp because it is possible to avoid the inclusion of impurities as much as possible and obtain a high content of alkali-insoluble α-cellulose among the cellulose components. By treating with alkali, alkali-soluble components can be removed and the purity of the cellulose can be increased.

[0030] As the wood pulp, for example, one or more types can be selected and used from chemical pulps such as hardwood kraft pulp (LKP) and softwood kraft pulp (NKP), and mechanical pulp (TMP).

[0031] The hardwood kraft pulp may be bleached hardwood kraft pulp, unbleached hardwood kraft pulp, or semi-bleached hardwood kraft pulp. Similarly, the softwood kraft pulp may be bleached softwood kraft pulp, unbleached softwood kraft pulp, or semi-bleached softwood kraft pulp.

[0032] The mechanical pulp can be one or more selected from stone ground pulp (SGP), pressurized stone ground pulp (PGW), refiner ground pulp (RGP), chemi-ground pulp (CGP), thermo-ground pulp (TGP), ground pulp (GP), thermo-mechanical pulp (TMP), chemi-thermomechanical pulp (CTMP), refiner mechanical pulp (RMP), bleached thermo-mechanical pulp (BTMP), etc. However, to avoid the inclusion of impurities other than the cellulose mentioned above, it is particularly preferable to use chemical pulp such as hardwood kraft pulp (LKP) or softwood kraft pulp (NKP).

[0033] Prior to defibration of the fine fibrous cellulose, it may be pretreated by a chemical method, such as hydrolysis of polysaccharides with an acid (acid treatment), hydrolysis of polysaccharides with an enzyme (enzyme treatment), swelling of polysaccharides with an alkali (alkali treatment), oxidation of polysaccharides with an oxidizing agent (oxidation treatment), or reduction of polysaccharides with a reducing agent (reduction treatment).

[0034] When the pulp is treated with alkali prior to defibration, some of the hydroxyl groups in the hemicellulose and cellulose in the pulp dissociate, and the molecules become anionic, weakening the intramolecular and intermolecular hydrogen bonds and promoting the dispersion of cellulose fibers during defibration.

[0035] Examples of the alkali used in the alkali treatment include organic alkalis such as sodium hydroxide, lithium hydroxide, potassium hydroxide, aqueous ammonia, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, and benzyltrimethylammonium hydroxide. However, from the viewpoint of production costs, it is preferable to use sodium hydroxide.

[0036] By subjecting the fine fibrous cellulose to an enzyme treatment, acid treatment, or oxidation treatment prior to defibration, the water retention of the fine fibrous cellulose can be reduced, the degree of crystallinity can be increased, and the homogeneity can be improved. In this regard, when the water retention of the fine fibrous cellulose is low, it becomes easier to dehydrate, and the dehydration of the dispersion of the fine fibrous cellulose (hereinafter also referred to as "slurry") is improved.

[0037] When raw pulp is subjected to enzyme treatment, acid treatment, or oxidation treatment, the amorphous regions of hemicellulose and cellulose contained in the pulp are decomposed. Decomposing the amorphous regions can reduce the energy required to refine the pulp and improve the homogeneity and dispersibility of the cellulose fibers. When cellulose fibers have excellent homogeneity and dispersibility, the cellulose powder produced from the fine fibrous cellulose tends to have little variation in particle size and be homogeneous. When the particle size of the cellulose powder varies greatly, the cellulose powder may not be sufficiently dispersed in the solid powder cosmetic and may be unevenly distributed. Therefore, the degree of decomposition of the amorphous regions of hemicellulose and cellulose contained in the pulp is an important factor. However, excessive pretreatment is preferably avoided because it reduces the aspect ratio of the fine fibrous cellulose and may result in the production of cellulose powder with a particle size that deviates from the desired average particle size.

[0038] The raw material pulp can be defibrated by beating the raw material pulp using, for example, a homogenizer such as a beater, a high-pressure homogenizer, or a high-pressure homogenizer, a grinder, a millstone-type friction machine such as a grinder, a single-screw kneader, a multi-screw kneader, a kneader refiner, a jet mill, etc. However, it is preferable to use a refiner or a jet mill.

[0039] The raw material pulp is preferably defibrated so that the average fiber diameter, average fiber length, water retention, degree of crystallinity, coefficient of variation of fiber diameter distribution, peak value in the pseudo-particle size distribution curve, pulp viscosity, and B-type viscosity of the dispersion (slurry) of the resulting fine fibrous cellulose have the desired values or evaluations shown below.

[0040] The average fiber diameter (average fiber width; average diameter of a single fiber) of the fine fibrous cellulose is preferably 1 to 500 nm, more preferably 3 to 500 nm, and particularly preferably 10 to 100 nm. If the average fiber diameter of the fine fibrous cellulose is less than 1 nm, the fine fibrous cellulose will have a high viscosity when made into a slurry, making it difficult to dry the fine fibrous cellulose to produce cellulose powder, and depending on the production method, the cellulose may dissolve, making it impossible to maintain the fibrous shape.

[0041] On the other hand, if the average fiber diameter of the fine fibrous cellulose exceeds 500 nm, the average particle diameter of the cellulose powder will become larger and the shape will become more distorted, such as rod-like or flat, which may make the solid powder cosmetic containing the cellulose powder more likely to feel rough or have a foreign body sensation.

[0042] The average fiber diameter of the fine fibrous cellulose can be adjusted, for example, by selecting the raw material pulp, pre-treating it, defibrating it, etc.

[0043] The average fiber diameter of the fine fibrous cellulose is measured as follows. First, 100 ml of an aqueous dispersion (slurry) of fine fibrous cellulose with a solid content of 0.01 to 0.1% by mass is filtered through a Teflon® membrane filter and solvent-substituted once with 100 ml of ethanol and three times with 20 ml of t-butanol. The sample is then freeze-dried and osmium-coated to obtain a sample. This sample is then observed using an SEM image at a magnification of 3,000x to 30,000x, depending on the width of the fibers that make up the sample. Specifically, two diagonal lines are drawn on the observed image, and three straight lines are arbitrarily drawn passing through the intersections of the diagonal lines. The widths of a total of 100 fibers intersecting with these three straight lines are then visually measured. The median diameter of the measured values is then taken as the average fiber diameter.

[0044] The average fiber length of the fine fibrous cellulose (average length of a single fiber) is preferably 0.3 to 200 μm, more preferably 0.4 to 200 μm, and particularly preferably 0.5 to 200 μm. If the average fiber length of the fine fibrous cellulose is less than 0.3 μm, the fibers will not aggregate well, making it difficult to produce a cellulose powder with a desired average particle size, and there is a risk that a cellulose powder with a small particle size or a large amount of aggregated, bundle-like particles will be produced.

[0045] On the other hand, if the average fiber length of the fine fibrous cellulose exceeds 200 μm, it is likely to become a powder with various shapes, which causes non-uniformity in particle shape and particle size.

[0046] The average fiber length of the fine fibrous cellulose can be adjusted, for example, by selecting the raw material pulp, pre-treating it, defibrating it, etc.

[0047] The average fiber length of the fine fibrous cellulose is measured in the same manner as in the case of the average fiber diameter, by visually measuring the length of each fiber. The median length of the measured values is taken as the average fiber length.

[0048] The aspect ratio of the fine fibrous cellulose is preferably 50 to 200,000, more preferably 50 to 10,000. If the aspect ratio is below 50, it is difficult to obtain cellulose powder with the desired average particle size. On the other hand, if the aspect ratio is above 200,000, the circularity of the cellulose powder will be small, which may impair the smoothness of the solid powder cosmetic.

[0049] The lower limit of the crystallinity of the fine fibrous cellulose is preferably at least 50, more preferably at least 60, and particularly preferably at least 70, and the upper limit is preferably no more than 100, more preferably no more than 95, and particularly preferably no more than 90. If the crystallinity is less than 50, the strength of the cellulose powder will be low, and a solid powder cosmetic preparation with excellent impact resistance may not be obtained.

[0050] The water retention of the fine fibrous cellulose is preferably 500% or less, more preferably 300% to 480%, unless chemically modified. If the water retention of the fine fibrous cellulose is less than 300%, the fine fibrous cellulose will not be defibrated to the desired size, and as a result, particles of the desired shape and size may not be obtained.

[0051] On the other hand, if the water retention of the fine fibrous cellulose exceeds 500%, the water retention capacity of the fine fibrous cellulose itself becomes high, and the drying process of the fine fibrous cellulose takes a long time.

[0052] The water retention of the fine fibrous cellulose can be adjusted, for example, by selecting the raw material pulp, pre-treating it, defibrating it, etc.

[0053] The water retention of the fine fibrous cellulose is a value measured in accordance with JAPAN TAPPI No. 26 (2000).

[0054] The pulp viscosity of the fine fibrous cellulose is preferably 1.0 to 7.0 mPa·s, more preferably 1.5 to 6.5 mPa·s, and particularly preferably 2.0 to 6.0 mPa·s. The degree of polymerization of the fine fibrous cellulose used in the cellulose powder is preferably 150 to 1250, more preferably 250 to 1150. Pulp viscosity is the viscosity of the solution obtained after dissolving cellulose in a copper ethylenediamine solution; a higher pulp viscosity indicates a higher degree of polymerization of the cellulose. Pulp viscosity is also related to the strength and rigidity of the cellulose fiber. A high degree of polymerization results in a hard cellulose powder, resulting in a rough solid powder cosmetic product even when additives are added. On the other hand, a low degree of polymerization results in a loss of fiber strength, which results in excessive plasticity required for the cellulose powder used in the present invention, making it difficult to control the moldability of the cosmetic product itself. The degree of polymerization of the fine fibrous cellulose can be adjusted, for example, by selecting the raw pulp, pre-treating, defibrating, etc. If the pulp viscosity is within the above range, the particles have good plasticity, and the resulting solid powder cosmetic has impact resistance and smoothness.

[0055] The fine fibrous cellulose obtained by defibration can be dispersed in an aqueous medium to form a dispersion (slurry) if necessary. The aqueous medium is particularly preferably entirely water (aqueous solution). However, the aqueous medium may also contain other liquids that are partially compatible with water. Examples of other liquids that can be used include lower alcohols having 3 or less carbon atoms.

[0056] The dispersion of fine fibrous cellulose (slurry, 2.0% by mass based on solids) preferably has a Brookfield viscosity of 400 mPa·s to 100,000 mPa·s, more preferably 500 to 50,000 mPa·s. If the Brookfield viscosity of the dispersion is within the above range, the slurry can be supplied to the drying device in the drying step without clogging.

[0057] The B-type viscosity of a dispersion of fine fibrous cellulose is a value measured in accordance with JIS-Z8803 (2011) "Method for measuring viscosity of liquids." B-type viscosity is the resistance torque when stirring the dispersion, and the higher the viscosity, the more energy is required for stirring.

[0058] Cellulose fibers can be defibrated using the following defibration devices and methods. Defibration can be performed using one or more of the following: homogenizers, such as high-pressure homogenizers and high-pressure homogenizers; grinders, grinders, and other mill-type friction machines; refiners, such as conical refiners and disc refiners; and various bacteria. However, defibration of cellulose fibers is preferably performed using devices and methods that use a water flow, particularly a high-pressure water flow, to refine the fibers. This device and method results in extremely uniform dimensions and uniform dispersion of the resulting fine fibrous cellulose. In contrast, using a grinder that grinds the fibers between rotating grindstones, for example, makes it difficult to uniformly refine the cellulose fibers, and in some cases, there is a risk that some undisintegrated fiber clumps may remain.

[0059] An example of a grinder used to defibrate cellulose fibers is the Masscolloider manufactured by Masuko Sangyo Co., Ltd. Furthermore, examples of devices that use high-pressure water flow to pulverize cellulose fibers include the Starburst (registered trademark) manufactured by Sugino Machine Co., Ltd. and the Nanovater (registered trademark) manufactured by Yoshida Kikai Kogyo Co., Ltd. Furthermore, an example of a high-speed rotary homogenizer used to defibrate cellulose fibers is the Clearmix-11S manufactured by M Technique Co., Ltd.

[0060] The solid powder cosmetic of the present embodiment contains cellulose powder, but may also contain a powder Y other than cellulose powder. In this specification, the concept of including cellulose powder and powder Y other than cellulose powder may be simply referred to as "powder" or "powder containing cellulose powder," etc.

[0061] (cellulose powder) The cellulose powder of this embodiment is an aggregate formed by drying fine fibrous cellulose. Microscopically, it can be formed by drying individual pieces of fine fibrous cellulose (for example, a single thread entangled within itself or dried out), or it can be formed by multiple pieces of fine fibrous cellulose aggregating during drying. Fine fibrous cellulose is produced from raw pulp, and the fibers wrinkle and shrink upon drying. The resulting cellulose powder has an uneven shape that is difficult to describe, such as a shape resembling an agglomeration of dried fine fibrous cellulose, a sugar candy shape, or a shape resembling one or more sheets of crumpled paper or other paper rolled up into a ball. The cellulose powder is white, pale yellow, cream, pale orange, or a mixture of these colors. White or pale yellow cellulose powders are particularly preferred because they are inconspicuous and can be used as a component of a solid powder cosmetic.

[0062] The cellulose powder of this embodiment preferably contains 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more of fine fibrous cellulose, with the upper limit being 100% by mass. If the mass percentage of fine fibrous cellulose in the cellulose powder is less than 50% by mass, the cellulose powder may not have the desired average particle size and aspect ratio.

[0063] Furthermore, since the cellulose powder has surface irregularities due to fine wrinkles formed on the surface, light irradiated from the outside hits the irregularities and is diffusely reflected at various angles. As a result, the surface of the cellulose powder lacks gloss, and solid powder cosmetics containing the cellulose powder have reduced shine.

[0064] Furthermore, since the cellulose powder of this embodiment is produced by, for example, drying, multiple pieces of dried and wrinkled fine fibrous cellulose may become entangled, forming irregularities on the surface. The fine fibrous cellulose dries in various ways, and the resulting cellulose powder becomes particles consisting of a single piece of dried fine fibrous cellulose or a plurality of aggregates of dried fine fibrous cellulose.

[0065] The cellulose powder contained in the solid powder cosmetic of this embodiment preferably has an average particle size of 1 to 25 μm, more preferably 2 to 24 μm, and even more preferably 3 to 23 μm, and an aspect ratio of preferably 0.6 to 0.90, more preferably 0.6 to 0.85. When the average particle size and aspect ratio of the cellulose powder are within the aforementioned ranges, the solid powder cosmetic will have impact resistance and smoothness. To achieve both impact resistance and smoothness, it is desirable that both the average particle size and the aspect ratio be within the aforementioned ranges; it is undesirable for either one to deviate from the aforementioned range. For example, even if the average particle size of the cellulose powder is within the aforementioned range, if the aspect ratio exceeds the aforementioned range, the impact resistance of the solid powder cosmetic may be impaired. Furthermore, even if the aspect ratio of the cellulose powder is within the aforementioned range, if the average particle size exceeds the aforementioned range, the smoothness of the solid powder cosmetic may be impaired. The aspect ratio of the cellulose powder is the value obtained by dividing the minor axis diameter of the cellulose powder by the major axis diameter of the cellulose powder.

[0066] The moisture content of the cellulose powder in a 50% humidity atmosphere is preferably 1 to 15%, more preferably 3 to 10%. If the moisture content of the cellulose powder is within the aforementioned range, the impact resistance of the solid powder cosmetic will be even better. The moisture content of the cellulose powder can be adjusted by the concentration of fine fibrous cellulose in the fine fibrous cellulose dispersion liquid, which is the raw material for the cellulose powder, the drying time, the average fiber width of the fine fibrous cellulose, and the like. However, with the drying techniques described below, it may be difficult to adjust the moisture content of the cellulose powder to be lower than the lower limit of the aforementioned range. Furthermore, if the moisture content of the cellulose powder exceeds the aforementioned range, there is a risk that the solid powder cosmetic will deteriorate over long-term use.

[0067] The bulk density of the cellulose powder is 0.5 g / cm 3 or less, preferably 0.1 to 0.5 g / cm 3 , more preferably 0.1 to 0.4 g / cm 3 The bulk density of the cellulose powder is 0.5 g / cm 3If the thickness exceeds , the solid powder cosmetic will not have a good adhesion feel (the "adhesion feel" refers to the feeling that the solid powder cosmetic is sufficiently adhering to the target of application, such as the skin), and the moist feeling will be poor, making it difficult to pick up the solid powder cosmetic with a puff.

[0068] The circularity of the cellulose powder is preferably 0.5 to 0.9, more preferably 0.6 to 0.85. If the circularity of the cellulose powder is within the above range, the resulting solid powder cosmetic will have excellent impact resistance and smoothness. If the circularity is less than 0.5, smoothness may decrease, and if it exceeds 0.9, impact resistance may decrease.

[0069] The aspect ratio and circularity can be measured using a Morphologi 4 manufactured by Malvern Panalytical. 3 was collected in a sample cartridge and dispersed on a glass plate using a dispersion unit, and then analyzed using static image analysis with a particle count of 20,000.

[0070] The compressive strength (10% strength) of the cellulose powder is preferably 5 MPa or less, more preferably 0.5 to 5 MPa. If the compressive strength of the cellulose powder exceeds 5 MPa, the powder will feel hard and rough, and will lack smoothness.

[0071] The specific surface area of the cellulose powder is preferably 1.0 m 2 / g or more, more preferably 1.0 to 10m 2 / g, more preferably 1.5 to 8m 2 / g. The specific surface area is 1.0 m 2 If the surface roughness is less than 1 / g, the cellulose powder has a shape with few irregularities, which results in poor adhesion of the solid powder cosmetic, and causes noticeable dryness and powderiness.

[0072] (additives) The cellulose powder produced through the drying process described above may contain additives to improve the dispersibility of the cellulose powder in the composition of the solid powder cosmetic, to prevent skin dryness, and to provide moisturizing effects (emollient effect). This is because cellulose powder may aggregate with other particles if left standing after production. One of the reasons for this is thought to be the polarity of the cellulose molecules that make up the cellulose powder. As a result, the cellulose powder may not be dispersed throughout the solid powder cosmetic, and may be unevenly distributed. Therefore, by including an additive in the cellulose powder, the polarity of the cellulose molecules in the cellulose powder is masked, making the cellulose powder less likely to aggregate with other particles and more easily dispersed throughout the solid powder cosmetic. The additive in the present invention may be any additive capable of masking the polarity of cellulose molecules or physically preventing strong aggregation of cellulose fibers during drying. Considering that the additive is mixed with the cellulose fiber dispersion in advance, it is preferably a hydrophilic material, and more preferably a hydrophilic material having an OH group (hydroxyl group), a CO group (carbonyl group), or a COOH group (carboxyl group). Because the cellulose powder of this embodiment is hydrophilic, the inclusion of the additive, which is a hydrophilic material, maintains the moisture content of the cellulose powder within a desired range, thereby providing the solid powder cosmetic with excellent impact resistance.

[0073] Additives include polyhydric alcohols, polysaccharides, water soluble One or more additives selected from the group consisting of soluble polymers and surfactants can be used. The content of the additive in the cellulose powder is preferably 1 to 49% by mass, more preferably 2 to 48% by mass. If the content is too high, the cellulose powder becomes sticky and loses its light feel, resulting in a poor feel on the skin. On the other hand, if the content is too low, the above-mentioned dispersion effect and emollient effect may not be achieved.

[0074] As the additive, the polyhydric alcohol may be a polyhydric alcohol having 2 to 6 carbon atoms and 2 to 3 oxygen atoms. Specific examples include, but are not limited to, glycerin, diglycerin, propylene glycol, 1,3-butylene glycol, 1,2-pentanediol, dipropylene glycol, 1,2-hexanediol, heptanediol, ethylene glycol, diethylene glycol, 1,3-propanediol, and 3-methyl-1,3-butanediol. Glycerin is particularly preferred from the viewpoints of viscosity-increasing properties and dispersibility of composite particles.

[0075] Examples of polysaccharides that can be used include, but are not limited to, quince seed, veegum, xanthan gum, and hyaluronate. Hyaluronate is particularly preferred from the viewpoint of thickening properties and dispersibility of cellulose powder.

[0076] Examples of water-soluble polymers include polyvinyl alcohol, polyvinylpyrrolidone, carboxyvinyl polymer, polyethylene glycol, homopolymers or copolymers containing a monomer having a phosphorylcholine group as a constituent monomer, homopolymers or copolymers containing a monomer having a sugar residue as a constituent monomer, and homopolymers or copolymers containing a monomer having an amino acid residue as a constituent monomer. Specific examples include, but are not limited to, copolymers of alkyl (meth)acrylate and polymethacryloyloxyethyl phosphorylcholine, copolymers of alkyl (meth)acrylate and methacryloyloxyethyl glucoside, and copolymers of alkyl (meth)acrylate and methacryloyl-L-lysine. Polyvinylpyrrolidone is particularly preferred in terms of thickening properties and dispersibility of cellulose powder.

[0077] Examples of surfactants include anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants. Nonionic surfactants are particularly preferred to eliminate the effects of ionic bonds. On the other hand, adding a cationic surfactant to anionic cellulose fibers can cause excessive aggregation of the cellulose fibers during powder production (drying), making it difficult to control the shape of the powder.

[0078] Examples of nonionic surfactants include polyoxyalkylene alkyl ethers, glycerin alkyl ethers, glycerin fatty acid esters, polyglycerin fatty acid esters, sorbitan fatty acid esters and their alkylene glycol adducts, polyalkylene glycol fatty acid esters, polyglycerin-modified silicones, polyether-modified silicones, etc. Examples of anionic surfactants include alkyl phosphates, polyoxyalkylene alkyl ether phosphates, sulfonates, alkyl sulfates, polyaspartates, etc. Examples of cationic surfactants include alkylamine salts and alkyltrimethylammonium salts. Examples of amphoteric surfactants include hydrogenated lecithin, carbobetaine-type amphoteric surfactants, sulfobetaine-type amphoteric surfactants, and amino acid-type amphoteric surfactants.

[0079] (Inorganic fine particles) The cellulose powder may contain inorganic fine particles. Inorganic fine particles can impart various functions to the cellulose powder, and for example, metallic inorganic fine particles have the effect of diffusing and reflecting incident light. By incorporating such inorganic fine particles into the cellulose powder, it is expected that the effects of suppressing ultraviolet radiation and suppressing shine on the skin at the application site can be achieved.

[0080] The upper limit of the inorganic fine particle content in the cellulose powder is preferably 49% by mass, and is preferably 45% by mass or less, and the lower limit is preferably 0% by mass, and is preferably 5% by mass or more. If the content exceeds 49% by mass, the specific gravity of the cellulose powder increases by the amount of the inorganic fine particles contained, which may impair dispersibility in the solid powder cosmetic. On the other hand, if the content is 5% by mass or more, the effect of diffuse reflection of incident light is fully exhibited.

[0081] The upper limit of the primary particle diameter of the inorganic fine particles may be 10 μm, preferably 5 μm or less, and more preferably 1 μm or less. If the primary particle diameter of the inorganic fine particles exceeds 10 μm, the inorganic fine particles are less likely to be supported by the fine fibrous cellulose. There is no particular restriction on the lower limit of the primary particle diameter of the inorganic fine particles, but it may be 1 nm, preferably 2 nm or more, and more preferably 3 nm or more. If the primary particle diameter of the inorganic fine particles is 1 nm or more, when the inorganic fine particles are mixed with the raw material slurry used to produce cellulose powder, the inorganic fine particles tend to disperse and cling to the fine fibrous cellulose.

[0082] The primary particle diameter of the inorganic fine particles can be measured by observation under an electron microscope, and the average value of the obtained particle diameters is taken as the measured value.

[0083] Although inorganic fine particles can be used as they are, hydrophilic treatment is preferred because it makes them more easily compatible with the raw material slurry used to produce cellulose powder. The surface treatment agent used for hydrophilic treatment has the effect of suppressing the surface activity of the inorganic fine particles, improving the dispersibility of the inorganic fine particles, and improving transparency and squeaking. The surface treatment agent for inorganic fine particles is not particularly limited as long as it is a treatment agent that can be dispersed in the raw material slurry, but those containing silicic anhydride or hydrated silicic acid are preferred.

[0084] The inorganic fine particles are not particularly limited, and known inorganic fine particles can be used, including, for example, barium titanate, lead zirconate titanate, silicon carbide, silicon nitride, aluminum nitride, alumina, zirconia, zircon, titanium oxide, zinc oxide, iron oxide, and cerium oxide. To improve the effect of suppressing ultraviolet radiation and the effect of suppressing skin shine, for example, one or a combination of two or more selected from the group consisting of titanium oxide, zinc oxide, iron oxide, and cerium oxide can be used. Titanium oxide is particularly preferred as the inorganic fine particles, as it improves the effect of suppressing ultraviolet radiation.

[0085] The shape of the inorganic fine particles that can be contained in the cellulose powder is not particularly limited, but can be, for example, spherical, rod-like, needle-like, spindle-like, plate-like, polygonal, or the like.

[0086] The inorganic fine particles may be attached to the surface of the fine fibrous cellulose in the cellulose powder, or may be encapsulated in the fine fibrous cellulose. If the inorganic fine particles are encapsulated in the fine fibrous cellulose, the inorganic fine particles can be supported not only on the surface of the cellulose powder but also inside, which is preferable because incident light is diffusely reflected even when irradiated from various angles. Here, encapsulation can refer to a state in which a portion of the surface of the inorganic fine particles is covered with the fine fibrous cellulose, or a state in which, when the cellulose powder is observed from the outside, the inorganic fine particles are covered with the fine fibrous cellulose and cannot be observed from the outside.

[0087] The inorganic fine particles can be added to the fine fibrous cellulose dispersion before drying, and may be mixed uniformly.

[0088] The solid powder cosmetic of this embodiment preferably contains 1 to 99% by mass of cellulose powder, more preferably 3 to 60% by mass, and even more preferably 5 to 40% by mass. If the cellulose powder content is less than 1% by mass, the solid powder cosmetic will have poor impact resistance.

[0089] (Production of cellulose powder) Cellulose powder can be produced by drying fine fibrous cellulose in a drying process. Specifically, it can be produced by freeze-drying the fine fibrous cellulose as a raw material, vacuum drying, heat drying (e.g., hot drying), spray drying, or spray-type freeze-vacuum drying, which is a method for drying the cellulose powder of this embodiment. Cellulose powder produced by heat drying or spray drying has an average particle size and aspect ratio that make it suitable for use in the solid powder cosmetic composition of this embodiment.

[0090] Among the heat drying techniques, the drum drying method for producing cellulose powder makes it possible to obtain a dried product that is less likely to aggregate and is easily dispersed, even from fine fibrous cellulose that is relatively highly concentrated or has poor fluidity. One example of the production of cellulose powder by the drum drying method is as follows.

[0091] The fine fibrous cellulose can be supplied to a drum dryer in the form of a slurry (aqueous dispersion), for example, where the drying process is performed. In this case, the content of the fine fibrous cellulose (bone dry mass%) is 1 mass% or more, preferably 1.5 mass% and more preferably 2.0 mass%. The content is 10 mass% or less, preferably 7 mass% and more preferably 5 mass%. If the content exceeds 10 mass%, the viscosity of the slurry becomes too high, making it difficult to handle. On the other hand, if the content is less than 1 mass%, removing the water requires a lot of energy and time, which is not economical.

[0092] The drum dryer used in the drum drying process may be a known one. For example, a "John Milder JM-T" manufactured by Johnson Boiler Company can be used. An internal rotation drum dryer is preferably used as the drum dryer. An internal rotation drum dryer performs gentle drying and produces a dried product with a relatively small specific surface area. The drying process can be carried out under normal pressure.

[0093] Regarding the operating conditions of the drum dryer, the surface temperature of the inner surface of the drum is 80 to 200°C, preferably 90 to 190°C. At this surface temperature, a dried product with strong cohesion can be obtained. If the surface temperature exceeds 200°C, some of the fibers of the fine fibrous cellulose may be thermally denatured. On the other hand, if the surface temperature is below 80°C, not only will it take a long time to remove the moisture, but the resulting particles will have a very high moisture content. The rotation speed of the drum dryer can be set to, for example, 0.5 rpm or more and 2 rpm or less, depending on the inner diameter of the drum and the amount of slurry added. The drying time in the drum dryer, depending on the amount of slurry added, is sufficient if it is 1 to 60 seconds, and the moisture content of the dried product will not decrease further even if it is dried for a longer period of time.

[0094] An example of an apparatus used to produce cellulose powder by spray drying is a spray dryer (P-260 manufactured by Pris). Cellulose powder can be produced by supplying a slurry of fine fibrous cellulose to the spray dryer. The spray dryer can be, for example, a two-fluid nozzle type equipped with two 90-type nozzles. The spray drying conditions can be, for example, a fine fibrous cellulose slurry of 20 kg / h, a drying air inlet temperature of 200°C, an outlet temperature of 100°C, and an atomizing air pressure of 0.6 MPa, but are not limited to these.

[0095] When producing cellulose powder containing the above-mentioned additives, the additives are mixed with a slurry of fine fibrous cellulose, which is the raw material for production, to form a mixture, and this mixture is then supplied to a drying device (e.g., a drum dryer or a spray dryer) used in a heat drying method or a spray drying method.

[0096] (oil content) The solid powder cosmetic of the present embodiment may contain oil. The inclusion of oil in the solid powder cosmetic improves moldability and provides excellent impact resistance, but because the solid powder cosmetic contains cellulose powder, it can achieve good impact resistance even with a smaller amount of oil than conventional cosmetics.

[0097] Any oil can be used regardless of its origin, such as animal oil, vegetable oil, or synthetic oil, or its state, such as solid oil, semi-solid oil, liquid oil, or volatile oil.

[0098] The oil component may be one or a combination of two or more selected from hydrocarbons, oils and fats, waxes, hardened oils, ester oils, fatty acids, silicone oils, fluorine-based oils, lanolin derivatives, oil-soluble ultraviolet absorbers, etc.

[0099] More specifically, for example, hydrocarbons such as liquid paraffin, squalane, petrolatum, paraffin wax, ceresin wax, microcrystalline wax, Japan wax, and montan wax; oils and fats such as olive oil, castor oil, jojoba oil, mink oil, and macadamia nut oil; waxes such as beeswax, lanolin, carnauba wax, candelilla wax, and glabra; esters such as isostearyl isostearate, cetyl isooctanoate, isopropyl myristate, isopropyl palmitate, octyldodecyl myristate, glyceryl trioctanoate, glyceryl tribehenate, rosin acid pentaerythritol ester, diisostearyl malate, dilinoleyl dimer dilinoleate, and neopentyl glycol dioctanoate; low-polymerization dimethylpolysiloxane, high-polymerization dimethylpolysiloxane, methylphenylpolysiloxane, (dimethicone)

[0039] One or a combination of two or more of the following may be used: silicones such as silicone gels composed of crosslinked silicones and solvents, such as methacrylic acid / vinyl dimethicone crosspolymers; fluorine-modified silicones; fluorine-based oils such as perfluoropolyether, perfluorodecane, and perfluorooctane; lanolin derivatives such as lanolin, lanolin acetate, lanolin fatty acid isopropyl, and lanolin alcohol; lipophilic surfactants having an HLB value of 8 or less, such as sorbitan isostearate, sorbitan sesquiisostearate, polyglyceryl-2 isostearate, and polyglyceryl-2 diisostearate; and oil-soluble UV absorbers such as ethylhexyl methoxycinnamate, ethylhexyl dimethyl PABA, diethylamino hydroxybenzoyl hexyl benzoate, ethylhexyl triazone, and bisethylhexyloxyphenol methoxyphenyl triazine. Furthermore, among these, when one or more selected from high-viscosity ester oils having a viscosity of 1,000 to 50,000 mPa·s at 25°C, such as diisostearyl malate and dilinoleyl dimer dilinoleate, and lipophilic surfactants, such as sorbitan sesquiisostearate and polyglyceryl-2 diisostearate, are used in combination, the moldability and moist feel can be further improved.

[0100] The oil content in the solid powder cosmetic of this embodiment is preferably 0.1 to 40% by mass, more preferably 0.1 to 25% by mass, and particularly preferably 1 to 15% by mass. If the oil content is less than 0.1% by mass, moldability may decrease. On the other hand, if the oil content exceeds 40% by mass, the cosmetic is less likely to be picked up by a cosmetic puff such as a sponge, making it difficult to spread the cosmetic onto the skin. Because the solid powder cosmetic of this embodiment contains cellulose powder, moldability can be maintained with a lower oil content than usual, resulting in a cosmetic that is easy to pick up with a puff and spread.

[0101] (Other powder Y) The solid powder cosmetic of this embodiment can be blended with a powder Y other than the cellulose powder. When the powder Y is included, the stickiness of the cosmetic film can be further reduced, and when the solid powder cosmetic of this embodiment is used as a base makeup cosmetic, the covering power and finish feel can be made as desired. The powder Y other than the cellulose powder has an average particle diameter of 0.01 to 200 μm.

[0102] The powder Y other than cellulose powder is not limited by, for example, its shape (e.g., spherical, plate-like, spindle-like, needle-like, etc.), particle size, particle structure (e.g., porous, non-porous, etc.), etc. Furthermore, the powder Y other than cellulose powder may be one or a combination of two or more selected from inorganic color pigments, inorganic extender pigments, inorganic fine particle powders, glitter powders, organic extender pigments, and organic color pigments.

[0103] Specific examples of the powder Y other than the cellulose powder include inorganic color pigments such as titanium oxide, zinc oxide, zirconium oxide, red iron oxide, yellow iron oxide, black iron oxide, carbon black, chromium hydroxide, ferric iron, and ultramarine; inorganic body pigments such as mica, sericite, talc, kaolin, synthetic phlogopite, anhydrous silicic acid (silica), magnesium carbonate, calcium carbonate, aluminum hydroxide, alumina, aluminum silicate, magnesium silicate, aluminum magnesium silicate, silicon carbide, barium sulfate, calcium silicate, zeolite, calcined calcium sulfate (calcined gypsum), calcium phosphate, hydroxyapatite, and boron nitride; inorganic fine particle powders having an average primary particle size of 100 nm or less, such as titanium oxide, zinc oxide, and cerium oxide; luster powders such as bismuth oxychloride, mica titanium, iron oxide-coated mica, iron oxide-coated mica titanium, organic pigment-coated mica titanium, and aluminum powder; magnesium stearate, zinc stearate, N-acyl lysine, polyurethane, polystyrene, nylon, polymethyl methacrylate, cellulose, polymethylsilsesquioxane powder, organopolysiloxane elastomer powder, cellulose other than the above-mentioned cellulose powder, crystalline cellulose, polyethylene, crosslinked polymethyl (meth)acrylate, polyester, styrene-acrylic acid copolymer, benzoguanamine, tetrafluoroethylene, organic pigments such as cellulose acetate; Red No. 201, Red No. 202, Red No. 204, Red No. 205, Red No. 220, Red No. 226, Red No. 228, Red No. 405, Orange No. 203, Orange No. 2 and organic pigments such as Red No. 04, Yellow 205, Yellow 401, and Blue 404; water-soluble dye lakes (zirconium lake, barium lake, aluminum lake, etc.) such as Red No. 3, Red No. 104, Red No. 106, Red No. 227, Red No. 230, Red No. 401, Red No. 505, Orange 205, Yellow No. 4, Yellow No. 5, Yellow No. 202, Yellow No. 203, Green No. 3, and Blue No. 1; and organic coloring pigments such as natural dyes and their lakes.

[0104] From the viewpoints of feel upon use and cosmetic durability, the powder Y other than the cellulose powder is preferably surface-hydrophobized. Examples of such surface-hydrophobization treatments that can be used include known surface-hydrophobization treatments such as baking treatment with silicones such as methylhydrogenpolysiloxane and (dimethicone / methicone) copolymer, treatment with fatty acids such as stearic acid, treatment with fatty acid metal soaps such as aluminum stearate and zinc stearate, treatment with acylated amino acids, treatment with lipoamino acids which is a mixed treatment of acylated amino acids (salts) and fatty acids (salts), treatment with fluorine such as perfluoroalkyl phosphates, silylation treatment with trimethylsilane, and treatment with acidic esters such as isostearyl sebacate.

[0105] The solid powder cosmetic of this embodiment preferably contains an inorganic filler pigment that has been surface-hydrophobized, from the viewpoint of improving the feel during use, such as cosmetic durability and ease of application and spreadability. Preferred inorganic filler pigments that constitute the surface-hydrophobized inorganic filler pigment include plate-like powders with a volume average particle diameter of 1 to 50 μm. Specific examples of such plate-like powders include talc, sericite, mica, synthetic phlogopite, and boron nitride. For surface-hydrophobized inorganic filler pigments, acidic ester treatment, acylated amino acid treatment, or lipoamino acid treatment is preferred, as these treatments provide excellent moldability, moisturizing effect, and cosmetic durability. Specific preferred examples of the surface hydrophobic treatment include an isostearyl sebacate treatment, which is an acidic ester treatment; an aluminum stearoyl glutamate treatment, which is an acylated amino acid treatment; and a combined treatment of palmitoyl proline, magnesium palmitoyl glutamate, sodium palmitoyl sarcosine, and aluminum palmitate, which is a lipoamino acid treatment.

[0106] Among the powders Y other than the above-mentioned cellulose powders, particularly spherical inorganic and organic powders, such as spherical silica, polyurethane, polystyrene, nylon, polymethyl methacrylate, polymethylsilsesquioxane powder, organopolysiloxane elastomer powder, cellulose other than the above-mentioned cellulose powders, crystalline cellulose, cellulose acetate, etc., can be used to effectively conceal irregularities such as pores and fine wrinkles, resulting in a desirable finish.

[0107] The content of the powder containing the cellulose powder (i.e., the combination of the cellulose powder and powder Y other than cellulose powder) is preferably 60 to 99.9 mass%, more preferably 70 to 99 mass%, and particularly preferably 80 to 95 mass%, of the total amount of the solid powder cosmetic. If the content of the powder containing the cellulose powder is less than 60 mass%, the powder will not be easily removed by a cosmetic puff such as a sponge, and the cosmetic film that is formed will tend to be sticky.

[0108] When the solid powder cosmetic of this embodiment contains a plate-like inorganic filler pigment, the content of the plate-like inorganic filler pigment is preferably 1 to 95% by mass, more preferably 5 to 90% by mass, and particularly preferably 10 to 85% by mass, based on the total amount of the solid powder cosmetic. Here, the term "plate-like" is not particularly limited, but refers to a particle shape in which, for example, the aspect ratio (length / thickness) is calculated by observing particles using a scanning electron microscope (SEM) and measuring the thickness and length of each cross section. When the content of the plate-like inorganic filler pigment is low, adhesion (to the skin) tends to be poor. On the other hand, when a large amount of the plate-like inorganic filler pigment is contained, there is a concern that moldability and drop strength may be impaired. However, in the solid powder cosmetic of this embodiment, even when the plate-like inorganic filler pigment is blended in an amount exceeding 70% by mass, the cellulose powder improves moldability, resulting in excellent moldability and drop strength.

[0109] When the solid powder cosmetic of this embodiment contains spherical inorganic powders and / or organic powders, the content of the spherical inorganic powders and / or organic powders is preferably 1 to 40% by mass, more preferably 3 to 35% by mass, and particularly preferably 5 to 30% by mass, relative to the total mass of the solid powder cosmetic. Here, "spherical" refers to a shape with a circularity of 0.8 to 1, as determined, for example, by the static image analysis method described above. If the content is too low, the effect of hiding irregularities will be poor, and if the content is too high, moldability will be reduced.

[0110] (moisturizer) The solid powder cosmetic of this embodiment can contain a moisturizing agent. Examples of moisturizing agents that can be used include polyhydric alcohols, sugars, sugar alcohols, amino acids, peptides, and water-soluble polymers. Examples of moisturizing agents that can be used include glycerin, diglycerin, propylene glycol, 1,3-butylene glycol, 1,2-pentanediol, dipropylene glycol, 1,3-propanediol, 1,2-hexanediol, heptanediol, 1,2-octanediol, ethylhexylglycerin, xylitol, sorbitol, maltitol, chondroitin sulfate, hyaluronic acid, collagen, sodium lactate, dl-pyrrolidone carboxylate, Rosa robur extract, yarrow extract, and melilot extract.

[0111] (others) In addition to the powders, oils, and moisturizers described above, the solid powder cosmetic of this embodiment can contain various ingredients that are typically contained in cosmetics, such as water-soluble ultraviolet absorbers, preservatives, antibacterial agents, fragrances, antioxidants, pH adjusters, chelating agents, cooling agents, anti-inflammatory agents, skin-beautifying ingredients, vitamins, amino acids, nucleic acids, and inclusion compounds.

[0112] (Applications, etc.) The solid powder cosmetic of the present embodiment is particularly suitable for use as a makeup cosmetic, such as pressed powder (solid white powder), powder foundation, wet / dry foundation, wet-only cake foundation, powder eye shadow, blush, face color, eyebrow pencil, etc. [Example]

[0113] The results of various tests conducted are shown below. The cellulose powder, silicone powder, and silica powder used in the test examples and reference examples were obtained as follows. The fine fibrous cellulose used was "ELLEX (registered trademark)-S" manufactured by Daio Paper Co., Ltd., and the glycerin used was special grade glycerin manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.

[0114] (Cellulose powder A) Fine fibrous cellulose was mixed with 30% glycerin by mass at 70% by solids to prepare a 3.0% aqueous dispersion of fine fibrous cellulose. The aqueous dispersion was spray-dried using a spray dryer (Pris Co., Ltd., "P-260") to obtain cellulose powder A. The average particle size of cellulose powder A was 13.5 μm. An SEM image of cellulose powder A is shown in Figure 1.

[0115] (Cellulose powder B) Fine fibrous cellulose was mixed with water to a solid content of 70% by mass and glycerin to a solid content of 30% by mass to prepare a fine fibrous cellulose aqueous dispersion. The aqueous dispersion was dried in a double drum dryer (Johnson Boiler's "John Milder JM-T") at a drum rotation speed of 3 rpm and a drum surface temperature of 135°C to obtain a dried product, which was then pulverized to obtain cellulose powder B. An SEM image of cellulose powder B is shown in Figure 2.

[0116] (Cellulose powder C) Cellulose powder C used was "Wako First-Class Cellulose, Powder, Passed through 38 μm (400 mesh)" manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Note that the cellulose raw material for cellulose powder C is not the fine fibrous cellulose used in the present invention. An SEM image of cellulose powder C is shown in Figure 3.

[0117] (Cellulose powder D) "CELLULOBEADS" manufactured by Daito Kasei Kogyo Co., Ltd. was used as cellulose powder D. The cellulose raw material for cellulose powder D is not the fine fibrous cellulose used in the present invention. An SEM image of cellulose powder D is shown in FIG. 4.

[0118] (Cellulose powder E) The fine fibrous cellulose was dispersed in water to a concentration of 3.0% on a solids basis to prepare a fine fibrous cellulose aqueous dispersion. No additives were added. The aqueous dispersion was spray-dried using a spray dryer (Pris Co., Ltd. "P-260") to obtain cellulose powder E.

[0119] (Silicone powder) The silicone powder used was "KSP-100" manufactured by Shin-Etsu Chemical Co., Ltd. Figure 5 shows an SEM image of the silicone powder.

[0120] (silica powder) The silica powder used was "CHIFFONSIL P-3R" manufactured by JGC Catalysts and Chemicals Co., Ltd. Figure 6 shows an SEM image of the silica powder.

[0121] The physical properties of the obtained powder were measured. The measured physical properties are shown in Table 1. The physical properties were measured according to the following procedure.

[0122] The bulk density was measured by the static method according to JIS-K-5101-12-1 (2004).

[0123] The moisture content was determined by the heat drying method, where 5 g of powder was left to stand for 24 hours, and the weight before and after drying was determined. More specifically, powder that had been left to stand for 24 hours or more under conditions of 50% humidity (i.e., pre-drying powder) was used, and dried at a temperature of 105°C for 24 hours to obtain a dried powder. The moisture content was calculated from the weight of the pre-drying powder and the weight of the dried powder using the following formula [Equation 1]. [Number 1] (Moisture content (%)) = [((weight of powder before drying) - (weight of powder after drying)) / (weight of powder after drying)] × 100

[0124] The compressive strength was measured using the Micro Autograph "MST-I" micro component strength evaluation device manufactured by Shimadzu Corporation, in accordance with JIS R1639-5 "Fine ceramics - Measurement methods for granular properties - Part 5: Single granule crushing strength."

[0125] The specific surface area (BET multipoint method) was measured using a specific surface area measuring device, "TriStar II 3020 N2 gas" manufactured by Shimadzu Corporation.

[0126] The cumulative distribution of equivalent circle diameter (number basis, cumulative 50% diameter), cumulative distribution of equivalent circle diameter (volume basis, cumulative 50% diameter), aspect ratio, and circularity were measured using Morphologi 4, a product of Spectris Corporation.

[0127] The mode diameter (most frequent diameter), median diameter (cumulative 50% diameter), average particle diameter, cumulative 10% diameter, and cumulative 90% diameter were measured using a measuring device conforming to ISO-13320 (2009), specifically the laser diffraction / scattering particle size distribution measuring device (particle size distribution) "LA-960V2," using a dry method without removing the moisture adhering to the cellulose powder.

[0128] The pulp viscosity and average degree of polymerization of cellulose were measured for each of the obtained cellulose powders A to D. The pulp viscosity was measured in accordance with TAPPI T 230. The average degree of polymerization of cellulose refers to the viscosity-average degree of polymerization measured in accordance with JIS-K6726.

[0129] [Table 1]

[0130] (Test Examples and Reference Examples) The powders obtained as described above were blended in the blending ratios shown in Tables 2 and 3. Specifically, for Test Examples 1 and 2 and Reference Examples 1 to 3 in Table 2, a mixture of one of the powders of Component Nos. 1 to 5 and Component Nos. 6 to 13 was mixed using a sample mill (Kyoritsu Rikosha product "SK-M10") at 10,000 rpm (scale 50) for 10 seconds to obtain a mixture as an intermediate product. Next, a homogeneous mixture of Component Nos. 15 to 19 was mixed with the mixture and further blended for 30 seconds using the sample mill to obtain the powder compositions for Test Examples 1 and 2 and Reference Examples 1 to 3, respectively.

[0131] For Test Example 3 and Reference Examples 4 to 7 in Table 3, a mixture of one of the powders of Component Nos. 1 to 4 and Component Nos. 5 to 13 was mixed using a sample mill (Kyoritsu Riko Co., Ltd. product "SK-M10") at 10,000 rpm (scale 50) for 10 seconds to obtain a mixture of intermediate products. Next, a homogeneous mixture of Component Nos. 14 to 19 (Component Nos. 14 to 20 for Reference Example 7) was mixed with the mixture and further mixed for 30 seconds using the sample mill to obtain the powder compositions for Test Example 3 and Reference Examples 4 to 7, respectively.

[0132] [Table 2]

[0133] [Table 3]

[0134] Each of the powder compositions obtained by the above procedure was filled into an aluminum metal dish with a diameter of 54 mm and press-molded using a press (a semi-automatic press "SSPP (hydraulic cylinder diameter 80 mm)" manufactured by Sanshin Seiki Co., Ltd.) at the press pressure shown in Table 4 to obtain Test Examples 1 to 3 and Reference Examples 1 to 7. The hardness of the obtained Test Examples 1 to 3 and Reference Examples 1 to 7 was measured. The hardness was measured using an "Olsen Hardness Tester" manufactured by Ueshima Seisakusho, which is a constant-load indentation hardness tester, under the condition of a load of 1 pound (=453.59 g). The hardness measurement results are shown in Table 4.

[0135] [Table 4]

[0136] (Performance evaluation test) Performance evaluation tests were conducted on the test examples and reference examples. The test items for the performance evaluation tests were drop strength, ease of removal with a puff, smoothness when applied to the skin, moist feeling when applied to the skin, and adhesion to the skin. The results of the performance evaluation tests are shown in Table 5.

[0137] [Table 5]

[0138] The drop strength test was carried out according to the following procedure. (1) From a height of 30 cm above a horizontally placed concrete block plane, the test example or reference example was allowed to fall freely with the flat surface of the test example or reference example kept horizontal, causing it to collide with the concrete block plane. (2) The above-mentioned operation (1) was repeated until the test example or reference example cracked. (3) If the number of trials in (1) and (2) above until the test example or reference example broke was 11 or more, it was judged as A; if it was 8 to 10, it was judged as B; if it was 5 to 7, it was judged as C; and if it was 4 or less, it was judged as D. Regarding the notation of drop strength in Table 5, for example, if the test example or reference example broke after 10 trials, it was marked as "B(10)".

[0139] The tests for ease of application to the puff, smoothness when applied to the skin, moist feeling when applied to the skin, and adhesion to the skin were carried out as follows: A panel of 10 female specialists used the test sample and the reference sample and evaluated them.

[0140] Specifically, the participants were asked to rate the ease of application to the puff, smoothness when applied to the skin, moist feeling when applied to the skin, and adhesion to the skin on a three-point scale: good (2 points), neutral (1 points), and bad (0 points). The average score was calculated from the scores obtained, and an average score of 1.5 or higher was assigned an A rating, 1.2 or higher but less than 1.5 was assigned a B rating, 0.5 or higher but less than 1.2 was assigned a C rating, and less than 0.5 was assigned a D rating.

[0141] The results in Table 5 reveal the following. Comparing Test Examples 1 and 2 with Reference Examples 1 to 3, which have similar powder amounts (90% by mass) and total amounts of oil and moisturizer (10% by mass), Test Example 1, which contains cellulose powder A, was excellent in all categories, whereas Reference Example 1, which contains commercially available spherical cellulose, and Reference Example 3, which contains commercially available spherical silica, were significantly inferior in the categories of ease of removal onto a puff, moist feeling upon application, and adhesion to the skin. Reference Example 2, which contains a silicone elastomer elastic powder, had cosmetic performance similar to Test Example 1, such as moist feeling, but was significantly inferior to Test Example 1 in drop strength. Test Example 2, which contains cellulose powder B with a larger average particle size, was excellent in drop strength, but was slightly inferior to Test Example 1 in the categories of ease of removal onto a puff, smoothness upon application, moist feeling upon application, and adhesion to the skin.

[0142] Comparing Test Example 3 and Reference Examples 4 to 7, which have similar powder amounts (95.95% by mass) and the same total amount of oil and humectant (4.05% by mass), Test Example 3 was excellent in all aspects even when the total amount of oil and humectant was low, whereas Reference Examples 4 to 6 all had insufficient drop strength. On the other hand, Reference Example 4, which contained commercially available cellulose powder C, had poor drop strength and was somewhat inferior in moist feeling, etc. Furthermore, Reference Example 6, which contained cellulose particles E produced from fine fibrous cellulose without any additives, was poor in drop strength and was somewhat inferior in smoothness, moist feeling, etc.

[0143] Reference Example 7, which does not contain any additives and uses cellulose powder E consisting of aggregates containing fine fibrous cellulose, improved the drop strength but was inferior in smoothness and feel on the skin. Note that the glycerin contained in Reference Example 7 was added to the mixture, which is the intermediate product, as one component of the moisturizing agent and did not constitute the aggregates. [Industrial Applicability]

[0144] The present invention can be used as a cosmetic material such as a primer, face powder, foundation, or base makeup cosmetic material.

Claims

1. The cellulose fiber contains an additive and is formed by aggregating fine fibrous cellulose having an average fiber width of 1 to 500 nm, the additive is one or a combination of two or more selected from the group consisting of polyhydric alcohols, polysaccharides, water-soluble polymers, and surfactants, A spray-dried product having an average particle size of 1 to 25 μm and a compressive strength of 5 MPa or less. A cellulose powder characterized by:

2. The aspect ratio of the fine fibrous cellulose is 50 to 200,000. The cellulose powder according to claim 1.

3. The fine fibrous cellulose contains 50% by mass or more. The cellulose powder according to claim 1.

4. The crystallinity of the fine fibrous cellulose is 50 or more. The cellulose powder according to claim 1.

5. The fine fibrous cellulose is not chemically modified. The cellulose powder according to claim 1.

6. The bulk density is 0.5 g / cm 3 or less. The cellulose powder according to claim 1.

7. The specific surface area is 1.0 m 2 / g or more. The cellulose powder according to claim 1.

8. The circularity is 0.5 to 0.

9. The cellulose powder according to claim 1.

9. The moisture content is 1 to 15% in an atmosphere of 50% humidity. The cellulose powder according to claim 1.

10. A cosmetic composition comprising: The cellulose powder according to claim 1.

Images