Oily solid cosmetic

Abstract

To provide an oily solid cosmetic that exhibits good moisture retention, adhesiveness, and shape retention without use of a surfactant.SOLUTION: An oily solid cosmetic according to an embodiment of the present invention contains a cellulose powder having an average particle diameter of 1 μm or more and 25 μm or less and an average aspect ratio of 0.60 or more and 0.9 or less, the cellulose powder being an aggregate containing a polyhydric alcohol and a fine fibrous cellulose having an average fiber diameter of 1 nm or more and 500 nm or less, the content of the cellulose powder being 0.1 mass% or more and 15 mass% or less, wherein the polyhydric alcohol is preferably glycerin. The oily solid cosmetic according to an embodiment of the present invention is preferably a lipstick.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to an oil-based solid cosmetic.

Background Art

[0002] Conventionally, oil-based solid cosmetics have been widely used in lipsticks, lip glosses, lip creams, foundations, stick foundations, pencil-type cosmetics, hair sticks, etc. In addition to the makeup effect, they are used for the purpose of providing smooth adhesion to the skin and a moist feeling. Because they are in solid form, they have the convenience of being easy to carry as compact-shaped or stick-shaped cosmetics. Since oil-based solid cosmetics are carried around, they need to maintain their shape even when carried around. In addition to the above-mentioned makeup effect and application performance, ease of molding and shape retention (the performance of maintaining the shape of a compact or stick, especially in the case of stick-shaped cosmetics, having sufficient breaking strength) are required. In oil-based solid cosmetics, there is known a solid stick-shaped cosmetic for the purpose of increasing the powder components such as colorants and extender pigments together with the spreadability and improving the breaking strength during use.

[0003] In such oil-based solid cosmetics, various considerations have been made regarding the makeup effect, application performance, moisturizing performance, etc. For example, in the prior art, there has been proposed a stick-shaped oil-based solid cosmetic with good productivity (ease of molding) and a good finished feeling (matte feeling and application uniformity) by blending spherical cellulose as a filler and petal-shaped calcium carbonate in a specific ratio (Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in conventional oil-based solid cosmetics, although a matte finish can be obtained, there are cases where the adhesiveness and shape retention are not sufficient, or a feeling of dryness may be felt. In recent years, from the viewpoints of low irritation to the skin and natural orientation, a reduction in the content of surfactants has been desired.

[0006] The present invention has been made based on the above circumstances, and an object thereof is to provide an oil-based solid cosmetic having good moisture retention, adhesiveness, and shape retention without using a surfactant.

Means for Solving the Problems

[0007] The oil-based solid cosmetic according to an embodiment of the present invention contains a cellulose powder having an average particle diameter of 1 μm or more and 25 μm or less and an average aspect ratio of 0.60 or more and 0.90 or less, and the cellulose powder is an aggregate containing a polyhydric alcohol and fine fibrous cellulose having an average fiber diameter of 1 nm or more and 500 nm or less, and the content of the cellulose powder is 0.1% by mass or more and 15.0% by mass or less.

Effects of the Invention

[0008] According to the present invention, an oil-based solid cosmetic having good moisture retention, adhesiveness, and shape retention can be provided without using a surfactant.

Modes for Carrying Out the Invention

[0009] [Description of Embodiments of the Present Invention] The oil-based solid cosmetic according to an embodiment of the present invention contains a cellulose powder having an average particle diameter of 1 μm or more and 25 μm or less and an average aspect ratio of 0.60 or more and 0.90 or less, and the cellulose powder is an aggregate containing a polyhydric alcohol and fine fibrous cellulose having an average fiber diameter of 1 nm or more and 500 nm or less, and the content of the cellulose powder is 0.1% by mass or more and 15.0% by mass or less.

[0010] When the oil-based solid cosmetic contains microfibrous cellulose previously containing a polyhydric alcohol, and contains cellulose powder having an average particle diameter of 1 μm or more and 25 μm or less and an average aspect ratio of 0.60 or more and 0.9 or less, it has excellent compatibility between the moisturizing component and the oil component, excellent shape retention, and good adhesiveness without containing a surfactant. When the content of the cellulose powder is 0.1% by mass or more and 15.0% by mass or less, elongation, adhesiveness, and moisturizing property can be improved. Further, when the average fiber diameter of the microfibrous cellulose is 1 nm or more and 500 nm or less, the shape of the cellulose fiber can be maintained, and the smoothness of the oil-based solid cosmetic containing the cellulose powder can be improved. Therefore, the oil-based solid cosmetic has good moisturizing property, adhesiveness, and shape retention without using a surfactant. Although the mechanism by which the above cellulose powder brings such effects to the oil-based solid cosmetic is not clear, (1) since the cellulose fiber is fine, in the oil-based cosmetic, a polyhydric alcohol having a moisturizing performance can be stably held in the oil-based cosmetic without a surfactant, and (2) the polyhydric alcohol present between the cellulose fibers inhibits the strong hydrogen bonds formed between the cellulose fibers, so that it becomes soft particles with many gaps and prevents aggregation of the particles, so it is considered to be easy to conform to the skin and improve the shape retention such as the breaking strength.

[0011] It is preferable that the polyhydric alcohol is glycerin. By the polyhydric alcohol being glycerin, the softness and dispersibility of the cellulose powder and the moisturizing property of the cosmetic can be improved.

[0012] The oil-based solid cosmetic is preferably a lipstick. The oil-based solid cosmetic can be suitably used for lip cosmetics in terms of the absence of dryness and the plump feeling due to improved moisturizing property. By using the oil-based solid cosmetic as a lipstick, the effects of the present invention can be more effectively exerted.

[0013] The oil-based solid cosmetic is preferably a stick cosmetic. By the oil-based solid cosmetic being a stick cosmetic, the ease of application and the ease of carrying can be imparted.

[0014] [Details of Embodiments of the Present Invention] Hereinafter, the present invention will be described in detail. The description of the constituent elements described below may be based on typical embodiments or specific examples, but the present invention is not limited to such embodiments.

[0015] [Oil-based Solid Cosmetics] The oil-based solid cosmetic according to an embodiment of the present invention contains cellulose powder, and the cellulose powder is an aggregate containing a polyhydric alcohol and microfibrillated cellulose.

[0016] [Cellulose Powder] The above cellulose powder is an aggregate containing a polyhydric alcohol and microfibrillated cellulose. More specifically, the cellulose powder contains an aggregate formed by drying microfibrillated cellulose (also referred to as "CNF"). This microfibrillated cellulose can be obtained by defibrating (miniaturizing) raw pulp. When looking at the cellulose powder microscopically, there are those formed by drying microfibrillated cellulose alone (for example, those formed by one thread entangling within the thread or formed by fluffing), and those formed by multiple microfibrillated celluloses aggregating into an aggregate during drying. Microfibrillated cellulose is manufactured from raw pulp, and when dried, the fibers wrinkle and shrink, so the resulting cellulose powder has a rough shape, such as the shape of aggregated fluff-like microfibrillated cellulose, the shape of dragees, or the shape formed by crumpling and rolling one or two or more sheets of paper such as waste paper. Also, the cellulose powder exhibits white, light yellow, cream color, light brown color, or a mixed color of these colors.

[0017] The content of microfibrillated cellulose in the cellulose powder is preferably 50% by mass or more, more preferably 60% by mass or more, further preferably 70% by mass or more, and even more preferably 75% by mass or more. If the mass percentage of microfibrillated cellulose in the cellulose powder is less than 50% by mass, the average particle diameter and average aspect ratio of the cellulose powder may not be within the desired range.

[0018] Since the cellulose powder has unevenness on its surface due to the fine wrinkles formed on the surface, the light irradiated from the outside hits the unevenness and is diffusely reflected at various angles. Therefore, the surface of the cellulose powder lacks a glossy feeling, and the oily solid cosmetic containing the cellulose powder has suppressed greasiness.

[0019] In addition, since the cellulose powder is, for example, manufactured by drying, fine fibrous cellulose that has shrunk and wrinkled may be entangled with each other to form unevenness on the surface. The shrinking pattern of the fine fibrous cellulose varies, and the formed cellulose powder becomes particles in the shape of single or aggregated dried fine fibrous cellulose.

[0020] The cellulose powder contained in the oily solid cosmetic has an average particle diameter of 1 μm or more and 25 μm or less, preferably 2 μm or more and 30 μm or less, more preferably 3 μm or more and 20 μm or less, and even more preferably 3 μm or more and 20 μm or less.

[0021] The mode diameter (most frequent diameter) of the cellulose powder is 1 μm or more and 25 μm or less, more preferably 2 μm or more and 20 μm or less, and even more preferably 3 μm or more and 18 μm or less. When the mode diameter of the cellulose powder is within the above range, the shape retention and compatibility of the oily solid cosmetic can be improved.

[0022] The mode diameter (most frequent diameter) and the average particle diameter can be measured using a measuring device compliant with ISO-13320 (2009). Specifically, it can be measured using a laser diffraction / scattering particle size distribution measuring device (particle size distribution) "LA-960V2". When using "LA-960V2", it can be measured by a dry method without removing the moisture attached to the cellulose powder.

[0023] The average aspect ratio of the cellulose powder is 0.60 or more and 0.90 or less, preferably 0.60 or more and 0.85 or less, and more preferably 0.60 or more and 0.80 or less. When the average particle diameter and the average aspect ratio of the cellulose powder are within the above ranges, the oil-based solid cosmetic has good shape retention and compatibility. The average aspect ratio of the cellulose powder is a value obtained by dividing the short-axis diameter of the cellulose powder by the long-axis diameter of the same cellulose powder.

[0024] The circularity of the cellulose powder is preferably 0.65 or more and 0.90 or less, and more preferably 0.70 or more and 0.85 or less. When the circularity of the cellulose powder is within the above range, the shape retention and stretchability of the oil-based solid cosmetic can be improved. If the circularity is less than 0.65, the stretchability may decrease. If it exceeds 0.90, the shape retention may decrease.

[0025] The average aspect ratio and circularity can be measured using Morphologi 4 manufactured by Malvern Panalytical. For the powder used as a sample, 3 mm 3 ~5 mm 3 is collected in a sample cartridge, dispersed on a glass plate using a dispersion unit, and then the numerical values are obtained by analyzing 20,000 particle counts by the static image analysis method.

[0026] The specific surface area of the cellulose powder is preferably 1.5 m 2 / g or more and 10.0 m 2 / g or less, more preferably 1.6 m 2 / g or more and 8.0 m 2 / g or less, and even more preferably 1.7 m 2 / g or more and 6.0 m 2 / g or less. When the specific surface area is less than 1.5 m 2 / g, since the surface of the cellulose powder has a shape with few irregularities, the adhesiveness of the oil-based solid cosmetic may not be sufficient.

[0027] (Microfibrillated cellulose) The cellulose powder contained in the oil-based solid cosmetic contains microfibrillated cellulose (also referred to as "CNF"), and this microfibrillated cellulose can be obtained by defibrating (miniaturizing) raw material pulp.

[0028] As the raw material pulp of microfibrillated cellulose, for example, one or more selected from wood pulp made from broad-leaved trees, coniferous trees, etc., non-wood pulp made from straw, bagasse, cotton, hemp, jute fiber, etc., waste paper pulp (DIP) made from recycled waste paper, waste paper, etc. can be selected and used.

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

[0030] As the wood pulp, for example, one or more selected from chemical pulps such as broad-leaved tree kraft pulp (LKP), coniferous tree kraft pulp (NKP), and mechanical pulp (TMP) can be selected and used.

[0031] The broad-leaved tree kraft pulp may be broad-leaved tree bleached kraft pulp, unbleached broad-leaved tree kraft pulp, or semi-bleached broad-leaved tree kraft pulp. Similarly, the coniferous tree kraft pulp may be coniferous tree bleached kraft pulp, unbleached coniferous tree kraft pulp, or semi-bleached coniferous tree kraft pulp.

[0032] As the mechanical pulp, for example, one or more kinds can be selected and used from stone ground pulp (SGP), pressurized stone ground pulp (PGW), refiner ground pulp (RGP), chemiground pulp (CGP), thermoground pulp (TGP), ground pulp (GP), thermomechanical pulp (TMP), chemithermomechanical pulp (CTMP), refiner mechanical pulp (RMP), bleached thermomechanical pulp (BTMP), etc. However, from the viewpoint of avoiding the mixing of impurities other than the above-mentioned cellulose, it is particularly preferable to use chemical pulps such as hardwood kraft pulp (LKP) and softwood kraft pulp (NKP).

[0033] Prior to the fibrillation of microfibrillar cellulose, pretreatment can also be carried out by chemical methods. Examples of the pretreatment by chemical methods include hydrolysis of polysaccharides by acids (acid treatment), hydrolysis of polysaccharides by enzymes (enzyme treatment), swelling of polysaccharides by alkalis (alkali treatment), oxidation of polysaccharides by oxidants (oxidation treatment), reduction of polysaccharides by reducing agents (reduction treatment), etc.

[0034] When alkali treatment is carried out prior to fibrillation, some of the hydroxyl groups of hemicellulose and cellulose in the pulp dissociate, and the molecules are anionized, weakening the intramolecular and intermolecular hydrogen bonds, and promoting the dispersion of cellulose fibers in fibrillation.

[0035] As the alkali used for alkali treatment, for example, organic alkalis such as sodium hydroxide, lithium hydroxide, potassium hydroxide, aqueous ammonia solution, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, benzyltrimethylammonium hydroxide, etc. can be used. However, from the viewpoint of production cost, it is preferable to use sodium hydroxide.

[0036] Prior to fibrillation, when enzyme treatment, acid treatment, or oxidation treatment is performed, the water retention of microfibrillar cellulose can be lowered, the crystallinity can be increased, and the homogeneity can be enhanced. In this regard, when the water retention of microfibrillar cellulose is low, it is easier to dehydrate, and the dehydrability of the dispersion of microfibrillar cellulose (hereinafter also referred to as "slurry") is improved.

[0037] When the raw material pulp is subjected to enzyme treatment, acid treatment, or oxidation treatment, the hemicellulose and amorphous regions of cellulose in the pulp are decomposed. Decomposing the amorphous regions can reduce the energy required for fibrillating the pulp and improve the homogeneity and dispersibility of the cellulose fibers. When the cellulose fibers are excellent in homogeneity and dispersibility, the cellulose powder produced from microfibrillar cellulose tends to have less variation in particle size and be homogeneous. If the variation in the particle size of the cellulose powder is large, there is a risk that the cellulose powder will not be sufficiently dispersed in the oil-based solid cosmetic and will be unevenly distributed. Therefore, the degree of decomposition of the hemicellulose and amorphous regions of cellulose in the pulp is one of the important factors. However, since the pretreatment reduces the average aspect ratio of the microfibrillar cellulose and may produce cellulose powder that deviates from the desired average particle size, it is preferable to avoid excessive pretreatment.

[0038] The fibrillation of the raw material pulp can be carried out, for example, by beating the raw material pulp using a homogenizer such as a beater, high-pressure homogenizer, high-pressure homogenization device, a mortar-type friction machine such as a grinder or attritor, 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 fibrillation of the raw material pulp is preferably carried out so that the average fiber diameter, average fiber length, water retention, crystallinity, coefficient of variation of the fiber diameter distribution, peak value in the pseudo particle size distribution curve, pulp viscosity, and B-type viscosity of the dispersion (slurry) of the obtained microfibrillar cellulose become the desired values or evaluations as shown below.

[0040] The average fiber diameter (average diameter of single fibers) of the microfibrillar cellulose is 1 nm or more and 500 nm or less, preferably 3 nm or more and 500 nm or less, and more preferably 10 nm or more and 100 nm or less. When the average fiber diameter of the microfibrillar cellulose is less than 1 nm, the viscosity becomes high when the microfibrillar cellulose is made into a slurry, making it difficult to dry the microfibrillar cellulose to produce a cellulose powder. Depending on the production method, there is also a risk that the cellulose will dissolve and the fiber shape cannot be maintained. On the other hand, when the average fiber diameter of the microfibrillar cellulose exceeds 500 nm, the average particle diameter of the cellulose powder becomes large, and the shape becomes more distorted, such as rod-like or flat-like. There is a risk that the oil-based solid cosmetic containing the cellulose powder will become rough or cause a foreign body sensation. The average fiber diameter of the microfibrillar cellulose can be adjusted, for example, by selecting raw pulp, pretreatment, fibrillation, etc.

[0041] The method for measuring the average fiber diameter of the microfibrillar cellulose is as follows. First, 100 ml of an aqueous dispersion (slurry) of microfibrillar cellulose with a solid content concentration of 0.01 mass% to 0.1 mass% is filtered through a Teflon (registered trademark) membrane filter, and the solvent is replaced once with 100 ml of ethanol and three times with 20 ml of t-butanol. Next, it is freeze-dried and osmium-coated to obtain a sample. This sample is observed by an SEM image of an electron microscope at a magnification of either 3000 times to 30000 times according to the thickness of the constituent fibers. Specifically, draw two diagonal lines on the observation image and arbitrarily draw three straight lines passing through the intersection of the diagonal lines. Furthermore, visually measure the thickness of a total of 100 fibers intersecting with these three straight lines. Then, the median diameter of the measured values is taken as the average fiber diameter.

[0042] The average fiber length (average length of single fiber) of the microfibrillar cellulose is preferably 0.3 μm or more and 200 μm or less, more preferably 0.4 μm or more and 200 μm or less, and even more preferably 0.5 μm or more and 200 μm or less. When the average fiber length of the microfibrillar cellulose is less than 0.3 μm, it becomes difficult for the fibers to aggregate, and there is a risk that a large amount of cellulose powder with a small particle size or aggregated bundle-shaped cellulose powder will be produced. On the other hand, when the average fiber length of the microfibrillar cellulose exceeds 200 μm, the shape of the cellulose powder tends to become irregular, causing non-uniformity in the shape of the cellulose powder and non-uniformity in the size of the cellulose powder.

[0043] The average fiber length of the microfibrillar cellulose can be adjusted, for example, by selecting raw pulp, pretreatment, fibrillation, etc.

[0044] The measurement method of the average fiber length of the microfibrillar cellulose is the same as in the case of the average fiber diameter, and the length of each fiber is visually measured. The median length of the measured values is taken as the average fiber length.

[0045] The average aspect ratio of the microfibrillar cellulose is preferably 30 or more and 200000 or less, and more preferably 30 or more and 10000 or less. When the average aspect ratio of the microfibrillar cellulose is less than 30, it may be difficult to obtain a cellulose powder with a desired average particle size. On the other hand, when the above average aspect ratio exceeds 200000, the circularity of the cellulose powder becomes small, and there is a risk that the smoothness of the oil-based solid cosmetic will be impaired.

[0046] The pulp viscosity of the microfibrillar cellulose is preferably 1.0 mPa·s or more and 7.0 mPa·s or less, more preferably 1.5 mPa·s or more and 6.5 mPa·s or less, and even more preferably 2.0 mPa·s or more and 6.0 mPa·s or less. Also, the degree of polymerization of the microfibrillar cellulose used for the cellulose powder is preferably 175 or more and 1250 or less, more preferably 250 or more and 1150 or less. The pulp viscosity is the viscosity of the solution after dissolving cellulose in a copper ethylenediamine solution, and the larger the pulp viscosity, the larger the degree of polymerization of cellulose. Also, the pulp viscosity is related to the strength and swelling of cellulose fibers. If the degree of polymerization becomes too high, it becomes a hard cellulose powder, and even if a polyhydric alcohol is mixed, it becomes a grainy oily solid cosmetic. On the other hand, if the degree of polymerization becomes too low, the strength of the fiber itself is lost, and the plastic force required for the cellulose powder used in the present invention becomes excessive. Although the adhesiveness is improved, it becomes difficult to improve the shape retention. The degree of polymerization of the microfibrillar cellulose can be adjusted, for example, by selection of raw material pulp, pretreatment, fibrillation, etc. If the pulp viscosity is within the above-mentioned range, the particles have good plasticity, and an oily solid cosmetic having shape retention and smoothness is obtained.

[0047] The microfibrillar cellulose obtained by fibrillation can be dispersed in an aqueous medium as a dispersion (slurry) if necessary. It is particularly preferable that the entire amount of the aqueous medium is water (aqueous solution). However, a part of the aqueous medium may be another liquid having compatibility with water. As the other liquid, for example, lower alcohols having 3 or less carbon atoms can be used.

[0048] The B-type viscosity of the dispersion (slurry, 2.0 mass% based on solid content) of the microfibrillar cellulose is preferably 400 mPa·s or more and 100000 mPa·s or less, more preferably 500 Pa·s or more and 50000 mPa·s or less. If the B-type viscosity of the dispersion is within the above-mentioned range, the supply of the slurry to the drying apparatus in the drying process can be performed without clogging.

[0049] The B-type viscosity of the fine fiber cellulose dispersion is the value measured in accordance with the "Method for Measuring Viscosity of Liquids" of JIS-Z8803 (2011). The B-type viscosity is the resistance torque when the dispersion is stirred, meaning that the higher it is, the more energy is required for stirring.

[0050] Defibration of cellulose fibers can be carried out by the defibration devices and methods shown below. The defibration can be carried out, for example, by selecting and using one or more means from homogenizers such as high-pressure homogenizers and high-pressure homogenization devices, stone mortar type friction machines such as grinders and polishers, refiners such as conical refiners and disk refiners, and various bacteria. However, it is preferable to carry out the defibration of cellulose fibers using a device and method for miniaturization with water flow, particularly high-pressure water flow. According to this device and method, the dimensional uniformity and dispersion uniformity of the obtained fine fiber cellulose are extremely high. On the other hand, for example, when using a grinder that grinds between rotating grindstones, it is difficult to uniformly miniaturize cellulose fibers, and in some cases, there is a risk that fiber lumps that cannot be unraveled will remain.

[0051] Examples of grinders used for defibrating cellulose fibers include the Mascoloider of Masu Kogyo Co., Ltd. Examples of devices for miniaturization with high-pressure water flow include "Starburst" (registered trademark) manufactured by Sugino Machine Ltd. and "Nano Vader" (registered trademark) manufactured by Yoshida Kikai Kogyo Co., Ltd.

[0052] (Polyhydric alcohol) In the oil-based solid cosmetic, the cellulose powder contains polyhydric alcohol, thereby obtaining the effects of improving the dispersibility in the composition of the oil-based solid cosmetic, preventing skin dryness, and imparting moisture (moisturizing effect). If the cellulose powder is left standing after production, it may aggregate with each other. This is considered to be due in part to the polarity of the cellulose molecules that make up the cellulose powder, and in the composition of the oil-based solid cosmetic, the cellulose powder may not be evenly dispersed but may be unevenly distributed. Therefore, by incorporating polyhydric alcohol into the cellulose powder, the polarity of the cellulose molecules in the cellulose powder is masked, making it difficult for the cellulose powder to aggregate with each other and facilitating its dispersion throughout the oil-based solid cosmetic. The polyhydric alcohol in the oil-based solid cosmetic only needs to be able to mask the polarity of the cellulose molecules or physically prevent strong aggregation of the cellulose fibers during drying. Considering the point of pre-mixing with the dispersion of the cellulose fibers, 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). Since the cellulose powder is hydrophilic, by incorporating a polyhydric alcohol, which is a hydrophilic material, into the cellulose powder, the moisture content of the cellulose powder is maintained within a desired range, and the oil-based solid cosmetic has excellent shape retention.

[0053] Examples of the polyhydric alcohol include polyhydric alcohols having 2 to 6 carbon atoms and 2 to 3 oxygen atoms. Specifically, glycerin, diglycerin, propylene glycol, 1,3-butylene glycol, 1,2-pentanediol, dipropylene glycol, 1,2-hexanediol, heptanediol, ethylene glycol, diethylene glycol, 1,3-propanediol, 3-methyl-1,3-butanediol, etc. can be used. Among these, glycerin is preferred as the polyhydric alcohol from the viewpoints of moisture retention and dispersibility of the cellulose powder. As the polyhydric alcohol, one or more selected from these can be used.

[0054] The content rate of the polyhydric alcohol in the cellulose powder is preferably 1% by mass or more and 49% by mass or less, more preferably 2% by mass or more and 48% by mass or less. If the upper limit of the content rate of the polyhydric alcohol exceeds 49% by mass, the cellulose powder may become sticky or lose its light feeling, resulting in a possible decrease in the adhesion to the skin. On the other hand, if the lower limit of the content rate of the polyhydric alcohol is less than 1% by mass, sufficient dispersion effect and moisture retention may not be obtained.

[0055] The lower limit of the content of the cellulose powder in the oily solid cosmetic of this form is 0.1% by mass, preferably 2.0% by mass, and more preferably 3.0% by mass. The upper limit of the content of the cellulose powder is 15% by mass, preferably 7% by mass, and more preferably 6.0% by mass. If the content of the cellulose powder is less than 0.1% by mass, the moisture retention of the oily solid cosmetic may be insufficient. On the other hand, if the content of the cellulose powder exceeds 15% by mass, elongation, adhesion and formability may decrease.

[0056] [Oily component] The oily solid cosmetic of this embodiment contains an oily component. The oily component consists of a solid oil and a liquid oil. In this specification, the solid oil refers to an oil component having a melting point of 50 ° C or higher and being solid at 25 ° C. The liquid oil refers to an oil component having a melting point of less than 50 ° C and being liquid to semi-solid at 25 ° C. The solid oil contributes to the shape retention of the oily solid cosmetic, and the liquid oil contributes to the ease of spreading and adhesion to the skin. By including the solid oil in the oily solid cosmetic, the formability is improved and the shape retention is excellent. However, since the oily solid cosmetic contains cellulose powder, good shape retention can be obtained with a smaller amount of solid oil than conventional cosmetics.

[0057] As the oily component, for example, any of animal oils, vegetable oils, synthetic oils, etc. can be used regardless of their origin or properties such as solid oils, semi-solid oils, liquid oils, volatile oils, etc.

[0058] As the oily component, for example, one or more selected from hydrocarbons, fats and oils, waxes, hydrogenated oils, ester oils, fatty acids, silicone oils, fluorine-based oils, lanolin derivatives, oil-soluble ultraviolet absorbers, etc. can be used in combination.

[0059] Specific examples of the solid oil include hydrocarbon waxes such as paraffin wax, polyethylene wax, ethylene-propylene copolymer, microcrystalline wax, ceresin, ozokerite, Fischer-Tropsch wax, etc., and beeswax, carnauba wax, rice wax, beeswax (bead wax), sunflower seed wax, candelilla wax, hydrogenated jojoba oil, hydrogenated oil, behenyl behenate, higher alcohols, silicone wax, etc.

[0060] From the viewpoint of shape retention, the lower limit of the content of the solid oil in the oily solid cosmetic is preferably 3% by mass, more preferably 4% by mass in the total composition. From the viewpoints of stretchability and adhesiveness, the upper limit of the content of the solid oil in the oily solid cosmetic is preferably 30% by mass, more preferably 25% by mass in the total composition.

[0061] Examples of the liquid oil include linear or branched hydrocarbon oils such as liquid paraffin, light isoparaffin, fluid isoparaffin, mineral oil, polybutene, polyisobutene, hydrogenated polyisobutene, hydrogenated polydecene, squalane, squalene; vegetable oils such as avocado oil, macadamia nut oil, olive oil, rapeseed oil, sesame oil, wheat germ oil, linseed oil, cottonseed oil, soybean oil, palm oil, coconut oil, castor oil, jojoba seed oil, sunflower oil, camellia oil, corn oil, macadamia nut oil, etc.; animal oils such as mink oil; fatty acids such as oleic acid; Diisostearyl malate, isopropyl myristate, isopropyl palmitate, octyldodecyl myristate, isopropyl isostearate, isostearyl isostearate, isononyl isononanoate, butyl stearate, oleyl oleate, isotridecyl isononanoate, isostearyl myristate, octyldodecyl ricinoleate, ethylhexyl palmitate, cetyl ethylhexanoate, ethylhexyl methoxycinnamate, cetyl isooctanoate, propylene glycol dicaprylate, neopentyl glycol dicaprylate, neopentyl glycol diethylhexanoate, propanediol diisostearate, propanediol di(caprylate / caprate), glyceryl tri(caprylate / caprate), triethylhexanoin, trimethylolpropane tri-2-ethylhexanoate, trimethylolpropane triisostearate, pentaerythrityl tetraoctanoate, pentaerythritol tetraethylhexanoate, polyglyceryl octacaprylate, polyglyceryl-2 diisostearate, polyglyceryl-2 triisostearate, (isostearic acid / sebacic acid) ditrimethylolpropane oligoester, dipentaerythrityl tripolyhydroxystearate, lauroyl glutamate di(phytosteryl / octyldodecyl), trehalose isostearate esters, ethylhexyl hydroxystearate, pentaerythrityl rosinate, dilinoleyl dilinoleate, phytosterol fatty acid ester, cholesterol fatty acid ester and other ester oils; Higher alcohols such as isostearyl alcohol, octyldodecanol, and decyltetradecanol can be mentioned. These liquid oils can be used alone or in combination of two or more kinds. Moreover, as the liquid oil, when one or more kinds 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 dilinoleate, are used in combination, the moldability and the lack of dry feeling can be further improved.

[0062] As the lower limit of the content of the liquid oil in the oily solid cosmetic, from the viewpoint of enhancing the ease of stretching and the adhesion during application, 47% by mass is preferable and 75% by mass is more preferable in the total composition.

[0063] As for the content of the oily component in the oily solid cosmetic, 50% by mass or more and 97% by mass or less is preferable, and 60% by mass or more and 93% by mass or less is more preferable. If the content of the oily component is less than 50% by mass, the adhesion to the skin may decrease. On the other hand, if the content of the oily component exceeds 97% by mass, the shape retention property may decrease.

[0064] (Powder component) The oily solid cosmetic can contain, in combination with the aforementioned cellulose powder, one or more powder components selected from coloring pigments and extender pigments. Examples of the powder include organic pigments such as zirconium, barium or aluminum lake of Red No. 201, Red No. 202, Red No. 205, Red No. 226, Red No. 228, Orange No. 203, Orange No. 204, Blue No. 404, Yellow No. 401, Red No. 3, Red No. 104, Red No. 106, Orange No. 205, Yellow No. 4, Yellow No. 5, Green No. 3, Blue No. 1, etc.; white inorganic pigments such as titanium oxide, zinc oxide, cerium oxide, barium sulfate, etc.; colored inorganic pigments such as iron oxide, carbon black, titanium·titanium oxide sintered product, chromium oxide, chromium hydroxide, ultramarine blue, ultramarine, etc.; pearlescent powders such as titanium oxide-coated mica, titanium oxide-coated bismuth oxychloride, iron oxide mica titanium, ultramarine-treated mica titanium, carmine-treated mica titanium, fish scale foil, etc.; inorganic extender pigments; and organic extender pigments.

[0065] (Other components) The oily solid cosmetic may contain, within the scope that does not impair the effects of the present invention, in addition to the powder, oily component, and pigment described above, other components commonly used in ordinary cosmetics. Examples of other components include oily components other than those described above, colorants, powders, lower alcohols, polymer compounds, water-soluble ultraviolet absorbers, antioxidants, fragrances, preservatives / antibacterial agents, pH adjusters, blood circulation promoters, anti-inflammatory agents, cooling agents, bactericides, skin activators, moisturizers, chelating agents, refreshing agents, beauty ingredients, vitamins, amino acids, nucleic acids, and inclusion compounds.

[0066] As uses, the oily solid cosmetic can be used, in addition to lip cosmetics such as lipsticks, lip creams, lip glosses, lip treatments, and lip bases, for concealers, foundations, blushes, and eyeshadows. As the form of the oily solid cosmetic, it can be in the form of a compact, a stick, or directly poured into a jar container or the like. Among these, the oily solid cosmetic can exhibit the effects of the present application more effectively when used as a stick-type lipstick.

[0067] [Manufacturing method of oily solid cosmetic] The oily solid cosmetic can be manufactured by known methods.

[0068] Also, the cellulose powder in the oily solid cosmetic can be obtained, for example, by the following manufacturing method.

[0069] (Manufacturing method of cellulose powder) Cellulose powder can be manufactured by drying microfibrillar cellulose in a drying process. Specifically, it can be manufactured by a method of freeze-drying, a method of drying under reduced pressure, a method of heating and drying (for example, a drying method by hot dry), a method of spray-drying, or a method of spray-type freeze-vacuum drying, which is the drying method of the cellulose powder of the present embodiment. In particular, cellulose powder manufactured by a method of heating and drying or a method of spray-drying has an average particle diameter and an average aspect ratio suitable for the composition of the oily solid cosmetic of the present embodiment.

[0070] Among the methods of heat drying, according to the method for producing cellulose powder by the drum drying method, even for relatively high-concentration or fine fibrous cellulose with poor fluidity, a dry product that is less likely to aggregate and is easy to disperse can be obtained.

[0071] The production of cellulose powder by the drum drying method is carried out as follows as an example. The fine fibrous cellulose can be supplied to, for example, a drum dryer that performs a drying process in a slurry (aqueous dispersion) state, or a spray dryer described later. In this case, the lower limit of the content of the fine fibrous cellulose is preferably 1.0% by mass, more preferably 1.2% by mass, and even more preferably 1.5% by mass. When the content of the fine fibrous cellulose is less than 1% by mass, a large amount of energy and time are consumed to remove moisture, which may be uneconomical. On the other hand, the upper limit of the content of the fine fibrous cellulose is preferably 10% by mass, more preferably 7% by mass, and even more preferably 5% by mass. When the content of the fine fibrous cellulose exceeds 10% by mass, the viscosity of the slurry may be too high, resulting in a lack of handleability.

[0072] The drum dryer used in the drying process by the drum drying method may be a known one. For example, the "Johnmilder JM-T type" manufactured by Johnson Boiler Co., Ltd. can be used. As the drum dryer, an internally rotating drum dryer can be preferably used. With an internally rotating drum dryer, a gentle drying process is performed, resulting in a dry product with a relatively small specific surface area. The drying process can be carried out under normal pressure.

[0073] As the operating conditions of the drum dryer, the surface temperature of the inner surface of the drum is preferably 80°C to 200°C, more preferably 90°C to 190°C. When the surface temperature of the inner surface of the drum is within the above range, a dried product with strong cohesive force can be obtained. If the above surface temperature exceeds 200°C, there is a risk that some of the fibers of the microfine fibrous cellulose will undergo thermal denaturation. On the other hand, if the above surface temperature is less than 80°C, not only will it take a long time to remove moisture, but the particles will have a very high moisture content. Also, the rotation speed of the drum dryer can be, for example, 0.5 rpm or more and 2 rpm or less, although it depends on the inner diameter of the drum and the input amount of the slurry. The drying time with the drum dryer depends on the input amount of the slurry, but if it is 1 second to 60 seconds, it will be sufficiently dried, and even if it is dried for a time exceeding this, the moisture content of the dried product will not become lower.

[0074] As an example of the apparatus used when producing the cellulose powder by the method of spray drying, a spray drying apparatus ("P-260" manufactured by Pulice Co., Ltd.) can be exemplified. The cellulose powder can be produced by supplying the slurry of the microfine fibrous cellulose to the spray drying apparatus. The spray drying apparatus can be, for example, of the two-fluid nozzle type, and one equipped with two 90-type nozzles can be used. The conditions for spray drying can be, for example, setting the slurry of the microfine fibrous cellulose to 20 kg / h, the inlet temperature of the drying air to 200°C, the outlet temperature to 100°C, and the spray air pressure to 0.60 MPa, but it is not limited to this.

[0075] When producing the cellulose powder containing the above polyhydric alcohol, the polyhydric alcohol may be mixed with the slurry of the microfine fibrous cellulose as the production raw material to form a mixture, and this mixture may be supplied to a drying apparatus equipped with a heat drying means or a spray drying means (for example, a drum dryer or a spray drying apparatus).

[0076] <Other Embodiments> The present invention is not limited to the above embodiments, and can be implemented in various modified and improved embodiments in addition to the above aspects.

Examples

[0077] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0078] The cellulose powder used in the examples and comparative examples was obtained as follows: "ELLEX (registered trademark)-S" manufactured by Daio Paper Co., Ltd. was used as the fine fibrous cellulose, and special grade glycerin manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. was used as the glycerin.

[0079] (Glycerin-containing cellulose powder A) Fine fibrous cellulose and glycerin were mixed to a concentration of 70% by mass (solids content) and 30% by mass, respectively, to obtain a 3.0% aqueous dispersion of fine fibrous cellulose (product "ELLEX (registered trademark)-S" manufactured by Daio Paper Co., Ltd.). The aqueous dispersion was spray-dried using a spray dryer ("P-260" manufactured by Glycerin Co., Ltd.) to obtain glycerin-containing cellulose powder A. The average particle size of the glycerin-containing cellulose powder A was 13.5 μm.

[0080] (Glycerin-containing cellulose powder B) A 2% by mass aqueous dispersion of fine fibrous cellulose ("ELLEX (registered trademark)-S" manufactured by Daio Paper Co., Ltd.) was dried in a double drum dryer ("John Milder JM-T" manufactured by Johnson Boiler) 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 glycerin-containing cellulose powder B. The average particle size of glycerin-containing cellulose powder B was 238.8 μm.

[0081] (Cellulose powder C) "Wako First Grade Cellulose, Powder, Passed through 38 μm (400 mesh)" manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. was used as cellulose powder C. Note that the cellulose raw material of cellulose powder C is not the fine fibrous cellulose used in the present invention.

[0082] (Spherical cellulose powder C) As the spherical cellulose powder D, "CELLULOBEADS" manufactured by Tohto Kasei Co., Ltd. was used. The cellulose raw material of the spherical cellulose powder D is not the fine fibrous cellulose used in the present invention.

[0083] The physical property values of the obtained cellulose powders were measured. The physical property values of each cellulose powder are shown in Table 1. The physical property values were measured by the following procedure.

[0084] The pulp viscosity and the average degree of polymerization of cellulose used for each of the cellulose powders A to D were measured. The pulp viscosity is a value measured in accordance with TAPPI-T230. The average degree of polymerization of cellulose refers to the viscosity average degree of polymerization measured in accordance with JIS-K6726.

[0085] The specific surface area (BET multipoint method) was measured using "TriStar II 3020 N2 gas", a product of Shimadzu Corporation, which is a specific surface area measuring device.

[0086] The average aspect ratio and roundness were measured using "Morphologi 4", a product of Spectris plc.

[0087] The mode diameter (most frequent diameter) and the average particle diameter were measured by a dry method without removing the moisture adhering to the cellulose powder using a measuring device conforming to ISO-13320 (2009), specifically, a laser diffraction / scattering type particle size distribution measuring device (particle size distribution) "LA-960V2".

[0088] [Examples 1 to 3 and Comparative Examples 1 to 9] Each component shown in Tables 2 and 3 was heated to about 90°C and uniformly mixed to obtain the compositions of Examples 1 to 3 and Comparative Examples 1 to 9. Next, the above compositions were filled into a stick container at 80°C while in a molten state, and then allowed to cool to obtain the solid lipsticks of Examples 1 to 3 and Comparative Examples 1 to 9. In Tables 2 and 3 below, "-" indicates that the corresponding component is not used or the corresponding evaluation is not carried out.

[0089]

Table 1

[0090]

Table 2

[0091]

Table 3

[0092] [Evaluation] For each obtained lipstick, evaluation was performed by the following method. The evaluation results are shown in Table 2 and Table 3.

[0093] (Compatibility (Uniformity)) The composition of each lipstick in the molten state was placed in a glass beaker and left standing for 10 minutes without stirring while maintaining the molten state (80 °C). The state was visually judged by the following evaluation criteria and judged by a two-stage evaluation of A and B. If the evaluation is A, it is considered qualified. A: It is in a uniform state from the top to the bottom. B: Sedimentation of powder or phase separation (such as separation of the glycerin phase, etc.) is observed, and evaluation of elongation, adhesiveness, and lack of dryness is impossible.

[0094] (Breaking Strength) Each lipstick filled and molded in a stick container with a diameter of 10 mm was horizontally held on the sample stage of a rheometer (「FUDOH Rheometer」 manufactured by Rheotech Co., Ltd.) in an environment of 30 °C. A T-shaped plunger was applied to a position 10 mm from the tip of the middle plate of the stick, and the sample stage was raised at a speed of 2 cm / min. The stress (N) when the stick broke was measured and taken as the breaking strength.

[0095] (Elongation, Adhesiveness, Lack of Dryness) Ten professional panelists applied each lipstick to their lips and conducted a sensory evaluation of elongation, adhesiveness, and lack of dryness on a scale of 1 to 5 based on the following scoring criteria (scores). For elongation, they evaluated whether the lipstick was easy to apply on the surface of the lips during application. For adhesiveness, they evaluated whether the lipstick adhered well to the lips after application. For lack of dryness, they evaluated whether there was no feeling of dryness after application. Then, for each lipstick, the average value was calculated from the total scores of all panelists and evaluated according to the following evaluation criteria. A passing grade was set for an evaluation of A. (Score) 5 points: Extremely excellent. 4 points: Excellent. 3 points: Ordinary. 2 points: Inferior. 1 point: Extremely inferior. (Evaluation Criteria) A: Average score of 4.0 points or more B: Average score of more than 3.5 points and less than 4.0 points C: Average score of more than 2.5 points and less than 3.5 points D: Average score of less than 2.5 points

[0096] (Skin Flexibility Test) The skin flexibility test was used to evaluate the effect of improving the moisturizing property of each lipstick. The skin viscoelasticity measuring device "Cutometer DUAL MPA580D" manufactured by COURAGE+KHAZAKA was used as the measuring instrument. Under the condition of a probe diameter of 2 mm, the elongation of the skin during the application of a negative pressure of 300 mbar for 5 seconds was defined as the skin flexibility. Then, the elongation of the skin was measured on the inner part of the forearm of 3 subjects. After that, each lipstick was applied to the same area at a thickness of approximately 2 mg / cm 2 and the elongation of the skin was measured 1 hour later. The increase rate of the elongation of the skin was calculated by the following formula. Increase rate of skin elongation [%] = 100 × elongation after 1 hour of application / elongation before application

[0097] As shown in Table 2 above, the lipstick of Example 1 contains a cellulose powder with an average particle size of 1 μm or more and 25 μm or less, and an average aspect ratio of 0.60 or more and 0.90 or less. The cellulose powder is an aggregate containing glycerin and microfibrillated cellulose. The average fiber diameter of the microfibrillated cellulose is 1 nm or more and 500 nm or less, and the content of the cellulose powder is 0.1% by mass or more and 15.0% by mass or less. It had high fracture strength, good compatibility, elongation, and adhesion feel. Also, after application of the lipstick, there was no dry feeling, the skin flexibility was high, and the moisturizing property was excellent. Generally, when the fracture strength of a lipstick is low, the adhesion tends to improve, and when the fracture strength is high, the adhesion amount tends to decrease. However, the lipstick of Example 1 achieved both high fracture strength and adhesion amount. This is considered because the shape of the particles of the cellulose powder with an average aspect ratio within a specific range becomes a distorted shape, and the cellulose powders exist in various directions within the matrix of the lipstick composed of the oily component, playing a role like a reinforcing material, thus improving the fracture strength. On the other hand, since the oil absorption of the cellulose powder is not high, the ability of the cellulose powder itself to hold the oily component is low. When the matrix collapses due to pressure or friction during application, it becomes easier to separate the oily component from the cellulose powder, resulting in improved adhesion.

[0098] On the other hand, Comparative Example 1 containing a cellulose powder containing glycerin and having an average particle size exceeding 25 μm had very poor compatibility, the cellulose powder settled, and a uniform composition could not be obtained. Therefore, the evaluation of elongation, adhesion, and the absence of dry feeling could not be carried out. Comparative Example 2 containing a cellulose powder not containing glycerin had good elongation, adhesion feel, fracture strength, and compatibility, but was inferior in the absence of dry feeling and moisturizing property. Comparative Example 3 containing a spherical cellulose powder not containing glycerin had good compatibility, elongation, and adhesion feel, but was inferior in fracture strength, the absence of dry feeling, and moisturizing property. Comparative Example 4, which contains plate-shaped lauroyl lysine instead of the cellulose powder containing glycerin and microfibrillar cellulose, had good breakage strength and compatibility, but the elongation, adhesion feel, and dryness were very poor. Comparative Example 5, which contains plate-shaped boron nitride instead of the cellulose powder containing glycerin and microfibrillar cellulose, had very poor breakage strength and a reduced lack of dryness. Comparative Example 6, which contains plate-shaped mica instead of the cellulose powder containing glycerin and microfibrillar cellulose, had good breakage strength and compatibility, but the elongation, adhesion feel, and dryness were very poor. In Comparative Example 7, in which glycerin and the cellulose powder used in Comparative Example 2 were each blended alone, since glycerin did not dissolve or disperse, a uniform composition could not be obtained and the compatibility was very poor. Therefore, the evaluation of elongation, adhesion, and lack of dryness could not be performed.

[0099] Also, as shown in Table 3, the lipsticks of Example 2 and Example 3, which contain a cellulose powder having an average particle diameter of 1 μm or more and 25 μm or less and an average aspect ratio of 0.60 or more and 0.90 or less, and the cellulose powder is an aggregate containing glycerin and microfibrillar cellulose, the average fiber diameter of the microfibrillar cellulose is 1 nm or more and 500 nm or less, and the content of the cellulose powder is 0.1% by mass or more and 15% by mass or less, had high breakage strength, good compatibility, elongation, and adhesion feel. Also, there was no dryness after application of the lipstick, and it was excellent in moisturizing property. In Comparative Example 8, in which the content of the cellulose powder containing glycerin and microfibrillar cellulose exceeded 15% by mass, the breakage strength and compatibility were good, but the elongation, adhesion feel, and lack of dryness were poor. Comparative Example 9, which excluded the cellulose powder containing glycerin and microfibrillar cellulose from Example 1, had good elongation, adhesion feel, and compatibility, but poor breakage strength and lack of dryness.

[0100] From the above results, it can be seen that the oil-based solid cosmetic has good moisture retention, adhesiveness, and shape retention without using a surfactant.

Claims

1. containing cellulose powder with an average particle diameter of 1 μm or more and 25 μm or less and an average aspect ratio of 0.60 or more and 0.90 or less, wherein the cellulose powder is an aggregate containing a polyhydric alcohol and microfibrillar cellulose, the average fiber diameter of the microfibrillar cellulose is 1 nm or more and 500 nm or less, and an oil-based solid cosmetic having a cellulose powder content of 0.1% by mass or more and 15% by mass or less.

2. The oil-based solid cosmetic according to Claim 1, wherein the polyhydric alcohol is glycerin.

3. The oil-based solid cosmetic according to Claim 1 or Claim 2, which is a lipstick.

4. The oil-based solid cosmetic according to Claim 1 or Claim 2, which is in stick form.

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