Cosmetic powders

Abstract

This invention provides a cosmetic powder that offers both a soft, moist texture and water-repellent properties, serving as an alternative to microplastic beads. [Solution] Cosmetics containing a divalent metal salt of octenyl succinate starch ester can achieve both a soft and moist feel and water repellency. The metal salt of the divalent metal salt of octenyl succinate starch ester is preferably a calcium salt, a zinc salt, or a magnesium salt. Furthermore, the degree of substitution of the octenyl succinate group in the divalent metal salt of octenyl succinate starch ester is preferably 0.020 to 0.034.

Description

Technical Field

[0001] The present invention relates to powders for cosmetics.

Background Art

[0002] Conventionally, for makeup cosmetics such as foundation, eyeshadow, and blush, sunscreen products such as UV care products, and basic cosmetics such as emulsions and creams, in order to impart a feeling such as a smooth feeling, a soft feeling, a soft feeling, or a moist feeling, it is known to contain water-insoluble spherical plastic powders such as silicone powders, nylon powders, and acrylic powders called microplastic beads. For example, Patent Document 1 describes a cosmetic characterized by containing a composite silicone powder in which silicone rubber spherical fine particles are coated with a polyorganosilsesquioxane resin. Patent Document 2 describes nylon powder, and spherical ones are preferred in terms of the unevenness correction effect. Patent Document 3 describes a water-using solid powder cosmetic characterized by containing spherical polymethyl methacrylate as an example of acrylic powder. In addition to having a good feeling in the above cosmetics, it is also required to suppress makeup collapse caused by water-soluble substances such as sweat and tears. Therefore, for the purpose of maintaining the finish and preventing makeup collapse, a powder for cosmetics having a surface treatment applied thereto to improve water repellency is blended. Patent Document 4 describes a cosmetic that exhibits an excellent effect of water resistance against sweat and the like by blending a powder subjected to a specific silicone treatment.

[0003] In recent years, concerns have been raised about marine pollution and adverse effects on human health caused by microplastic beads. Since microplastic beads do not decompose and remain in nature once released into the environment, there is a demand for cosmetics that do not contain microplastic beads. Cellulose and silica are examples of alternative particles to microplastic beads. Looking at conventional technologies, for example, Patent Document 5 describes a cosmetic that contains a specific spherical cellulose powder and exhibits excellent effects in terms of coverage, pore blurring effect, natural skin feel and transparency, and smooth adhesion. Patent Document 6 describes a gel-type cosmetic that contains a specific spherical silica and exhibits excellent effects in terms of usability, such as freshness and a smooth feeling after application. However, these materials have the problem that they cannot provide the soft and moist feel that microplastic beads provide, and cannot exhibit both a soft and moist feel and water repellency. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 9-20631 [Patent Document 2] Japanese Patent Publication No. 2015-193564 [Patent Document 3] Japanese Patent Publication No. 2014-172864 [Patent Document 4] Japanese Patent Publication No. 2007-119741 [Patent Document 5] Japanese Patent Publication No. 2005-170864 [Patent Document 6] Japanese Patent Publication No. 2023-119501 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] The objective of this invention is to provide a material that, when incorporated into cosmetics as a substitute particle for microplastic beads, exhibits both a soft, moist feel and water-repellent properties. [Means for solving the problem]

[0006] As a result of diligent research into the aforementioned problems, the inventors of the present invention have found that by including a divalent metal salt of octenyl succinate starch ester as a substitute particle for microplastic beads, a cosmetic product can be obtained that achieves both a soft, moist feel and water repellency.

[0007] One embodiment of the present invention is as follows. [Section 1] A cosmetic powder containing a divalent metal salt of octenyl succinate starch ester. [Section 2] The cosmetic powder according to item 1, wherein the metal salt of the divalent metal salt of octenyl succinate starch ester is one or more metal salts selected from the group consisting of calcium salts, zinc salts, and magnesium salts. [Section 3] The cosmetic powder according to [Item 1] or [Item 2], wherein the degree of substitution of the octenyl succinate group in the divalent metal salt of octenyl succinate starch ester is 0.020 to 0.034. [Effects of the Invention]

[0008] According to the present invention, by including a divalent metal salt of octenyl succinate starch ester, it is possible to provide a cosmetic that achieves both a soft, moist feel and water repellency without including microplastic beads.

[0009] The embodiments for carrying out the present invention will be described in detail below. However, the present invention is not limited to the following embodiments.

[0010] In this specification, "water repellency" refers to the property of a powder to repel water from its surface. One method for evaluating water repellency is to add 0.1 g of powder to a test tube containing 5 g of deionized water, mix by inversion, and visually determine the degree of turbidity of the water.

[0011] In this specification, a divalent metal salt of octenyl succinate starch ester is a compound in which one carboxyl group of octenyl succinate forms an ester bond with a hydroxyl group of starch X, and the other carboxyl group forms a salt with a divalent metal M, as shown in general formula (1). In formula (1), X is a starch residue, R is an octenyl group, and M is a divalent metal.

[0012] [ka]

[0013] In this specification, the divalent metal salt is not particularly limited, but examples include copper(divalent) salt, iron(divalent) salt, calcium salt, zinc salt, magnesium salt, barium salt, etc., and is preferably calcium salt, zinc salt, or magnesium salt. The divalent metal salt is not limited to one type, and may be one or more metal salts selected from the group consisting of copper(divalent) salt, iron(divalent) salt, calcium salt, zinc salt, magnesium salt, barium salt, etc., and is preferably one or more metal salts selected from the group consisting of calcium salt, zinc salt, and magnesium salt.

[0014] In this specification, the divalent metal salt of octenyl succinate starch ester is preferably such that the content of the divalent metal falls within the range described below. Here, the content of the divalent metal refers to the amount of divalent metal contained in the divalent metal salt of octenyl succinate starch ester. The content of the divalent metal in the divalent metal salt of octenyl succinate starch ester is not particularly limited, but is between 10 and 50,000 ppm, and is preferably between 100 and 10,000 ppm, and more preferably between 300 and 5,000 ppm, from the viewpoint of achieving both a soft and moist feel and water repellency.

[0015] The content of the divalent metal in the divalent metal salt of octenyl succinic acid starch ester can be measured by atomic absorption spectrometry. An appropriate analysis procedure can be selected according to the metal to be measured. For example, a method in which nitric acid is added to a suspension of a starch sample, decomposed by heating in a boiling water bath, and then subjected to an atomic absorption spectrometer; a method in which a starch sample is ashed in an electric furnace at 500 to 600 °C, and an aqueous solution of the ash is subjected to an atomic absorption spectrometer.

[0016] In formula (1), R represents an octenyl group, which is a monovalent unsaturated aliphatic hydrocarbon group having 8 carbon atoms and one double bond, and is represented by, for example, “-CH2CH=CH-(CH2)4-CH3”.

[0017] In this specification, the metal salt of octenyl succinic acid starch ester is a divalent metal salt of a starch ester of succinic acid having an octenyl group with 8 carbon atoms. As combinations of divalent metals, calcium octenyl succinic acid starch ester, zinc octenyl succinic acid starch ester, and magnesium octenyl succinic acid starch ester are preferable as cosmetic materials having a soft and moist feel and water repellency.

[0018] In this specification, the divalent metal salt of octenyl succinic acid starch ester preferably has a degree of substitution such that the degree of substitution of the octenyl succinic acid group is within the range described below. The degree of substitution of the octenyl succinic acid group in the divalent metal salt of octenyl succinic acid starch ester is usually 0.010 to 0.100, and from the viewpoint of achieving both a soft and moist feel and water repellency, it is preferably 0.015 to 0.050, more preferably 0.020 to 0.034.

[0019] Here, the degree of substitution is the average value of the number of substituted hydroxyl groups per glucose, which is a monosaccharide unit constituting starch. For example, a degree of substitution of 0.010 means that one hydroxyl group is substituted with R in formula (1) per 100 glucose molecules. The degree of substitution of the octenyl succinate group with respect to starch can be measured by the following method (acid titration). Disperse 1.0 g of the sample in 28.5 mL of a mixture of isopropyl alcohol and hydrochloric acid and stir for 30 minutes. Then, add 100 mL of 90% (v / v) isopropyl alcohol solution and stir for 30 minutes. After stirring, wash the dispersion with 90% (v / v) isopropyl alcohol solution while filtering by vacuum filtration or the like. Continue this operation until the turbidity of the filtrate disappears when 0.1 mol / L silver chloride aqueous solution is added to the filtrate. After washing, dry the filtrate with hot air. Then, disperse 0.10 g of the dried material in 55 mL of ethanol aqueous solution and heat gelatinize. After gelatinization, correct for water evaporation, add a few drops of phenolphthalein indicator, and add 0.1 N sodium hydroxide aqueous solution until the dispersion turns slightly pink, and calculate using the following formula. A = M × 0.1 × F / Sample amount (g) However, M is the titration volume (mL) of the 0.1N sodium hydroxide aqueous solution of the sample, and F is the factor of the 0.1N sodium hydroxide aqueous solution. Degree of substitution (DS)=0.162×A / (1-0.21×A)

[0020] In this specification, starch may be natural starch or modified starch.

[0021] Natural starch is starch obtained from natural raw materials and is not processed enzymatically or chemically. Its origin is not particularly limited, but examples include corn starch, waxy corn starch, high-amylose corn starch, rice starch, waxy rice starch, potato starch, waxy potato starch, tapioca starch, waxy tapioca starch, sweet potato starch, wheat starch, waxy wheat starch, high-amylose wheat starch, sago starch, kudzu starch, lotus starch, banana starch, adzuki bean starch, pea starch, and mung bean starch.

[0022] Modified starch is obtained by enzymatically or chemically processing starch obtained from natural raw materials in order to improve the inherent physical properties of starch (e.g., high viscosity, gelling properties upon cooling, etc.). The enzymatic or chemical processing of starch may be a single processing treatment or a combination of multiple enzymatic or chemical processing treatments. Modified starch that can be used in the present invention is not particularly limited, but examples include starch acetate, oxidized starch, phosphorylated starch, phosphate-crosslinked starch, hydroxypropyl starch, carboxymethyl starch, hydroxyethyl starch, esterified starch, graft polymerized starch, cationic starch, hydrolyzed starch, hydrolyzed hydrogenated starch, and hydroxypropyl phosphorylated starch. Furthermore, modified starch may also have the form of a metal salt, for example, modified starch derivatives obtained by adding a metal salt to modified starch such as sodium acrylate grafted starch or sodium octenyl succinate starch.

[0023] In the present invention, the divalent metal salt of octenyl succinate starch ester may be surface-treated using one or more surface treatment agents. Examples of surface treatments include, for example, fluorine compound treatment (perfluoroalkyl phosphate treatment, perfluoroalkyl silane treatment, perfluoropolyether treatment, fluorosilicone treatment, fluorinated silicone resin treatment, etc.), silicone treatment (methylhydrogenpolysiloxane treatment, dimethylpolysiloxane treatment, gas-phase tetramethyltetrahydrogencyclotetrasiloxane treatment, etc.), silicone resin treatment (trimethylsiloxysilicate treatment, etc.), pendant treatment (a method of adding alkyl chains, etc., after gas-phase silicone treatment), silane coupling agent treatment, titanium coupling agent treatment, aluminum coupling agent treatment, silane treatment (alkylated silane or alkylated silazane treatment, etc.), oil treatment, polyacrylic acid treatment, metal soap treatment (stearate or myristicate treatment, etc.), hydrogenated lecithin treatment, acrylic resin treatment, metal oxide treatment, etc., and it is also possible to use multiple of these treatments in combination.

[0024] In this specification, divalent metal salts of octenyl succinate starch ester are obtained by suspending starch in water, reacting it with octenyl succinate anhydride under alkaline conditions, and then adding a dry or aqueous solution of a soluble divalent metal salt such as a calcium salt.

[0025] The amount of octenyl succinic anhydride added is not particularly limited, but is preferably 2 to 10 parts by mass, and particularly preferably 3 to 7 parts by mass, per 100 parts by mass of starch.

[0026] The alkaline conditions are not particularly limited, but for example, they may be pH 7.0 to 10.0, and particularly preferably pH 7.5 to 9.0. The alkaline catalyst for achieving such alkaline conditions is not particularly limited and can be, for example, alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide; alkali metal carbonates such as sodium carbonate, potassium carbonate, and lithium carbonate; phosphates such as trisodium phosphate; alkali metal alkoxides such as sodium methoxide, sodium ethoxide, and potassium methoxide; ammonia; mono, di, or trialkylamines having alkyl groups such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, dipropylamine, butylamine, isobutylamine, secondary butylamine, tertiary butylamine, amylamine, secondary amylamine, tertiary amylamine, and hexylamine; or mono, di, or triethanolamines having alcohol groups such as triethanolamine, triisopropanolamine, and diethanolamine.

[0027] The reaction temperature is not particularly limited, but may be between 30°C and 55°C, and is particularly preferred to be between 35°C and 50°C.

[0028] When reacting octenyl succinic anhydride, soluble salts such as sodium chloride or sodium sulfate may be added as needed. In this specification, a soluble salt refers to a salt that is soluble in a starch dispersion. The amount of soluble salt added is not particularly limited, but is preferably 0.1 to 20 parts by mass, and particularly preferably in the range of 1 to 10 parts by mass, per 100 parts by mass of starch.

[0029] The soluble divalent metal salt may be, for example, calcium salts such as calcium chloride, calcium bromide, calcium iodide, calcium perchlorate, calcium chlorate, calcium hypochlorite, calcium nitrate, and calcium acetate; zinc salts such as zinc chloride, zinc bromide, zinc iodide, zinc sulfate, zinc nitrate, and zinc acetate; and magnesium salts such as magnesium chloride, magnesium bromide, magnesium iodide, magnesium sulfate, magnesium nitrate, and magnesium acetate.

[0030] When adding a soluble divalent metal salt, pH control may be performed as needed. The conditions for pH control are not particularly limited, but for example, a pH of 3.0 to 7.0, and especially a pH of 3.5 to 5.5, is preferred. The aqueous solution of the soluble metal salt should be at a concentration of 1 to 40%, and the amount of the soluble divalent metal salt should be within the range of the metal content mentioned above.

[0031] In this specification, a washing solvent may be added to the powder, and the powder may be washed by methods such as vacuum filtration to remove excess water-soluble metal salts (e.g., soluble metal salts). The washing solvent may then be removed by drying. The drying method is not particularly limited, but examples include sun drying and forced-air drying, as well as drum dryers, extruders, spray dryers, freeze dryers, shelf dryers, belt dryers, fluidized bed dryers, and microwave dryers. The drying temperature is not particularly limited, but examples include 20°C to 300°C.

[0032] The powder obtained in this way may still be highly aggregated, so grinding may be carried out as the next step. The grinding method is not particularly limited, but examples include hammer mills, roller mills, pin mills, jet mills, ball mills, bead mills, and cutter mills. Grinding may be carried out before or after drying. In addition, the particle size may be adjusted by sieving after grinding.

[0033] Furthermore, it is preferable that the particle size is within a specific range of the C value calculated by the following formula. C=(particle size D 90 - Particle size D 10 ) / particle size D 50 Particle size D 90 , particle size D 10 , particle size D 50 These values ​​represent the particle diameters of the cosmetic composition as viewed from the fine particle side at 90%, 10%, and 50% cumulative levels, respectively, as measured using a laser diffraction scattering particle size distribution analyzer. The C value is preferably less than 2.0, and more preferably less than 1.5. If the C value exceeds 2.0, the texture may become rough, and the soft and moist feel may be compromised.

[0034] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to the following examples. [Examples]

[0035] <Example 1> 200 g of corn starch was added to 300 g of water and uniformly dispersed. While maintaining a pH of 8.5 by adding 3% by mass of sodium hydroxide aqueous solution as needed, 12 g of octenyl succinic anhydride was added and the reaction was carried out at 45°C until the consumption of sodium hydroxide aqueous solution stopped (i.e., less than 5 g of sodium hydroxide aqueous solution per hour). After adjusting the reaction pH to 5.5 with hydrochloric acid, the reaction product was filtered and washed several times with water. After resuspending this reaction product in 500 g of water, an aqueous solution containing 6 g of calcium chloride dihydrate was added and the reaction was carried out. The reaction product was filtered, washed several times with water, and then air-dried. The dried product was pulverized and sieved to obtain calcium octenyl succinic starch ester. The degree of substitution (DS) was measured by the acid titration method described above, and the content of divalent metals was measured by atomic absorption spectrometry. The degree of substitution (DS) was 0.030, and the calcium content was 2700 ppm.

[0036] <Example 2> Octenyl succinate starch ester calcium was obtained by the same method as in Example 1, except that the amount of octenyl succinate anhydride used was changed to 14 g. The degree of substitution (DS) and the content of divalent metals were measured in the same manner as in Example 1. The degree of substitution (DS) was 0.034 and the calcium content was 4000 ppm.

[0037] <Example 3> Octenyl succinate starch ester calcium was obtained by the same method as in Example 1, except that the amount of octenyl succinate anhydride used was changed to 6 g. The degree of substitution (DS) and the content of divalent metals were measured in the same manner as in Example 1. The degree of substitution (DS) was 0.020 and the calcium content was 970 ppm.

[0038] <Example 4> Zinc starch ester octenyl succinate was obtained by the same method as in Example 1, except that calcium chloride dihydrate was replaced with zinc chloride. The degree of substitution (DS) and the content of divalent metals were measured in the same manner as in Example 1. The degree of substitution (DS) was 0.030, and the zinc content was 2900 ppm.

[0039] <Example 5> Magnesium starch ester octenyl succinate was obtained by the same method as in Example 1, except that calcium chloride dihydrate was replaced with magnesium sulfate. The degree of substitution (DS) and the content of divalent metals were measured in the same manner as in Example 1. The degree of substitution (DS) was 0.031, and the magnesium content was 2800 ppm.

[0040] <Reference example 1> Nylon 12 (SP-500 manufactured by Toray Industries, Inc.) was used as is.

[0041] <Comparative Example 1> Spherical silica (Godball D-25C manufactured by Suzuki Oil & Fat Industry Co., Ltd.) was used as is.

[0042] <Comparative Example 2> Octenyl succinate starch ester calcium was obtained by the same method as in Example 1, except that the amount of octenyl succinate anhydride used was changed to 16 g. The degree of substitution (DS) and the content of divalent metals were measured in the same manner as in Example 1. The degree of substitution (DS) was 0.038 and the calcium content was 5300 ppm.

[0043] <Comparative Example 3> Octenyl succinate starch ester calcium was obtained by the same method as in Example 1, except that the amount of octenyl succinate anhydride used was changed to 4 g. The degree of substitution (DS) and the content of divalent metals were measured in the same manner as in Example 1. The degree of substitution (DS) was 0.015 and the calcium content was 250 ppm.

[0044] <Rating> (Test 1) Tactile properties of powder The softness and moistness of each powder in the examples, reference examples, and comparative examples when applied to the skin were evaluated by 10 trained panelists using the following evaluation criteria. A score of 1 was the worst evaluation, and a score of 5 was the best evaluation. The average scores of all panelists in the sensory evaluation test are shown in Table 1. • Evaluation criteria 5: Excellent 4: Excellent 3: Normal 2: Inferior 1: Very inferior

[0045] (Test 2) Water repellency of powder 0.1 g each of the powders from the Examples, Reference Examples, and Comparative Examples were added to a test tube containing 5.0 g of deionized water. The mixture was then inverted and mixed, and the degree of turbidity of the water was visually evaluated according to the following criteria. A score of 4 or higher was considered to indicate excellent water repellency. The results of the water repellency test are shown in Table 1. • Evaluation criteria 5: The powder floats completely on the water surface, and the water does not become cloudy. 4: The powder is floating on the water surface, but the water is slightly cloudy. 3: The powder is floating on the water surface, but the water is clearly cloudy. 2: Some of the powder floats on the water surface, but most of it moves into the water. 1: All the powder is transferred into the water.

[0046] [Table 1]

[0047] As shown in Table 1, the divalent metal salts of octenyl succinate starch ester in Examples 1-5 all received extremely high evaluation scores of 4.0 or higher for both softness and moistness, resulting in a very excellent soft and moist feel. Furthermore, the divalent metal salts of octenyl succinate starch ester in Examples 1-5 all received evaluation scores of 4 or higher for water repellency, demonstrating excellent water repellency.

[0048] The divalent metal salts of octenyl succinate starch ester in Examples 1-5 were evaluated as being comparable to the nylon powder microplastic beads in Reference Example 1 in terms of softness, moisture, and water repellency, demonstrating excellent effectiveness as microplastic bead substitute particles. On the other hand, the existing microplastic bead substitute particles, calcium octenyl succinate starch ester in Comparative Examples 1, 2, and 3, did not exhibit excellent effects in terms of softness, moisture, or water repellency.

Claims

1. A cosmetic powder containing a divalent metal salt of octenyl succinate starch ester.

2. The cosmetic powder according to claim 1, wherein the metal salt of the divalent metal salt of octenyl lusuccinate starch ester is one or more metal salts selected from the group consisting of calcium salts, zinc salts, and magnesium salts.

3. The cosmetic powder according to claim 1 or claim 2, wherein the degree of substitution of the octenyl succinate group in the divalent metal salt of octenyl succinate starch is 0.020 to 0.034.

Images