Scrub

Abstract

This invention provides a scrubbing agent that is prepared from materials with excellent biodegradability, has minimal environmental impact, and exhibits excellent storage stability not only when incorporated into cosmetic compositions but also during storage before being incorporated into cosmetic compositions. [Solution] A scrubbing agent is provided that contains (A) a linear saturated aliphatic monohydric alcohol having 16 to 30 carbon atoms and (B) a fatty acid triglyceride with a melting point of 50°C or higher in a total amount of 90% by mass or more relative to the total amount of the scrubbing agent, the content ratio of component (A) to component (B) [(A):(B)] is 90:10 to 10:90 by mass ratio, and the median diameter is 50 μm to 2000 μm.

Description

[Technical Field]

[0001] The present invention relates to a scrubbing agent used in cosmetic compositions such as cleansing agents, facial washes, hand washes, body washes, and massage agents. [Background technology]

[0002] Traditionally, cosmetic compositions such as cleansers and massage products have contained scrubbing agents to remove dirt, sebum, and old dead skin cells, and to enhance the massage effect. However, polyethylene particles (microbeads), which have been used as scrubbing agents, have poor biodegradability. There are concerns that if released into the natural environment, they will remain for a long time, remain in the ecosystem, and accumulate, potentially causing various problems. As a result, the industry is implementing voluntary regulations. Therefore, naturally derived scrubbing agents are currently being considered. For example, Patent Document 1 discloses a particulate, naturally derived scrub agent made from natural materials, characterized by containing gelatinized starch and having a degree of gelatinization of 10% to 90%. This scrub agent is described as being able to reduce irritation to the skin, etc., by its soft surface while maintaining peeling and massage effects, and can be manufactured using an aqueous solvent. Furthermore, Patent Document 2 discloses a scrubbing agent which is a particle containing 70% by mass or more of a polyhydric alcohol fatty acid ester with a median diameter of 50 μm to 2000 μm and a melting point of 50°C or higher. By using this scrubbing agent in a cosmetic composition, it is possible to obtain a cleansing effect and massage effect comparable to that of cosmetic compositions using conventionally used scrubbing agents (synthetic resin particles). It is also described that it does not remain in the environment for a long period of time even when released into the environment, has little adverse impact on the environment, and has excellent storage stability. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2019-094277 [Patent Document 2] International Publication No. 2019 / 013238 [Overview of the project] [Problems that the invention aims to solve]

[0004] While the stability of scrubbing agents incorporated into cosmetic compositions has been examined in the technologies disclosed in Patent Documents 1 and 2, the storage stability of scrubbing agents before they are incorporated into cosmetic compositions has not been sufficiently studied. As a result, there is a risk that the particle size of the scrubbing agents may change when stored in high-temperature environments during the summer or when exported to tropical regions, or when subjected to loads or impacts during storage, and that they may not perform their intended function when incorporated into cosmetic compositions. Therefore, there is a need for a scrubbing agent that is prepared from materials with excellent biodegradability, has minimal environmental impact, and exhibits excellent storage stability not only when incorporated into cosmetic compositions, but also during storage before being incorporated into cosmetic compositions.

[0005] Therefore, the present invention aims to provide a scrubbing agent that is prepared from a material with excellent biodegradability, has little impact on the environment, and exhibits excellent storage stability not only when incorporated into a cosmetic composition, but also during storage before being incorporated into a cosmetic composition. [Means for solving the problem]

[0006] The present inventors, through diligent research to solve the above problems, have found that by creating a scrubbing agent containing (A) a linear saturated aliphatic monohydric alcohol having 16 to 30 carbon atoms and (B) a fatty acid triglyceride with a melting point of 50°C or higher in specific amounts and ratios, and having a median diameter of 50 μm to 2000 μm, it is possible to obtain a scrubbing agent that is excellent in biodegradability and excellent in storage stability not only when incorporated into cosmetic compositions but also before being incorporated into cosmetic compositions. Further research has led to the completion of the present invention.

[0007] In other words, the present invention relates to the following: [1] A scrubbing agent containing (A) a linear saturated aliphatic monohydric alcohol having 16 to 30 carbon atoms and (B) a fatty acid triglyceride with a melting point of 50°C or higher in a total amount of 90% by mass or more relative to the total amount of the scrubbing agent, wherein the content ratio of component (A) to component (B) [(A):(B)] is 90:10 to 10:90 by mass ratio, and the median diameter is 50 μm to 2000 μm. A cosmetic composition containing the scrubbing agent described in [2][1]. [Effects of the Invention]

[0008] The present invention provides a scrubbing agent that is prepared from a material with excellent biodegradability, has minimal environmental impact, exhibits excellent storage stability not only when incorporated into cosmetic compositions but also before incorporation into cosmetic compositions, and shows minimal change in particle size due to load or impact during storage. When incorporated into cosmetic compositions, the scrubbing agent of the present invention can stably provide a good scrubbing sensation and can effectively exhibit cleansing effects such as removing dirt, sebum, and old keratin from the skin, as well as massage effects. Furthermore, the present invention provides a cosmetic composition that is prepared from a material with excellent biodegradability, contains a scrubbing agent with excellent storage stability, has minimal environmental impact, and provides a stable and good scrubbing sensation. The cosmetic composition of the present invention can effectively exhibit cleansing effects such as the removal of dirt, sebum, and old keratin from the skin, as well as massage effects. [Modes for carrying out the invention]

[0009] The present invention provides a scrubbing agent. In this specification, "scrubbing agent" means particles used in a cosmetic composition primarily for the purpose of enhancing the massage effect and / or removing old keratin and sebum. The scrubbing agent of the present invention contains (A) a linear saturated aliphatic monohydric alcohol having 16 to 30 carbon atoms and (B) a fatty acid triglyceride with a melting point of 50°C or higher.

[0010] [(A) Linear saturated aliphatic monohydric alcohols with 16 to 30 carbon atoms] Examples of linear saturated aliphatic monohydric alcohols with 16 to 30 carbon atoms that may be included as component (A) in the scrubbing agent of the present invention include 1-hexadecanol (cetanol, palmityl alcohol), 1-octadecanol (stearyl alcohol), 1-eicosanol (arachidyl alcohol), 1-docosanol (behenyl alcohol), 1-tetracosanol (lignoceryl alcohol), hexacosanol (ceryl alcohol), 1-octacosanol, and 1-triacontanol (myricyl alcohol). If the number of carbon atoms in the linear saturated aliphatic monohydric alcohol is less than 16 or greater than 30, the storage stability of the scrubbing agent may deteriorate. The scrubbing agent of the present invention may contain, as component (A), one selected linear saturated aliphatic monohydric alcohol having 16 to 30 carbon atoms, or two or more selected alcohols in combination. From the viewpoint of storage stability of the scrubbing agent of the present invention, component (A) is preferably one that contains 80% by mass or more of a linear saturated aliphatic monohydric alcohol having 18 to 28 carbon atoms, and more preferably one that contains 80% by mass or more of a linear saturated aliphatic monohydric alcohol having 20 to 26 carbon atoms. The melting point of the linear saturated aliphatic monohydric alcohol having 16 to 30 carbon atoms, contained as component (A) in the scrubbing agent of the present invention, is preferably 50°C or higher, more preferably 60°C or higher, and even more preferably 70°C or higher, from the viewpoint of storage stability. Furthermore, from the viewpoint of storage stability, the melting point of the linear saturated aliphatic monohydric alcohol having 16 to 30 carbon atoms contained as component (A) in the scrubbing agent of the present invention is preferably 95°C or lower. In this invention, a linear saturated aliphatic monohydric alcohol having 16 to 30 carbon atoms can be produced and used by a known manufacturing method, or it can be a commercially available product provided by various companies.

[0011] [(B) Fatty acid triglycerides with a melting point of 50°C or higher] The fatty acid triglyceride with a melting point of 50°C or higher, contained as component (B) in the scrubbing agent of the present invention, is a triacylglycerol in which three molecules of fatty acids are ester-bonded to one molecule of glycerin, and is one of the neutral fats belonging to simple lipids. Examples of fatty acid triglycerides with a melting point of 50°C or higher include hydrogenated oils obtained by hydrogenating natural oils such as hydrogenated palm oil, hydrogenated rapeseed oil, and hydrogenated castor oil, as well as triesters of fatty acids derived from vegetable oils such as trihexadecanoic acid (palmitic acid) glyceride and trioctadecanoic acid (stearic acid) glyceride with glycerin. The scrubbing agent of the present invention may contain, as component (B), one selected fatty acid triglyceride having a melting point of 50°C or higher, alone, or two or more selected fatty acids triglycerides in combination. From the viewpoint of achieving a more pronounced effect of the present invention when used as a scrubbing agent together with component (A) above, it is preferable that component (B) consists of 60% to 95% by mass of hydroxysaturated fatty acid residues, and more preferably 70% to 90% by mass of hydroxysaturated fatty acid residues. Examples of hydroxysaturated fatty acids include 12-hydroxystearic acid and 9,10-dihydroxystearic acid. Furthermore, examples of fatty acid triglycerides having hydroxysaturated fatty acid residues as fatty acid residues constituting the fatty acid triglyceride include hydrogenated castor oil in which tri-12-hydroxystearic acid glyceride is the main component, and fatty acid triglycerides obtained from a mixture of 12-hydroxystearic acid and a linear saturated fatty acid such as stearic acid, and glycerin. These fatty acid triglycerides may also have fatty acid residues derived from polymers of hydroxystearic acid. The melting point of the fatty acid triglyceride contained as component (B) in the scrubbing agent of the present invention is 50°C or higher, preferably 60°C or higher, and more preferably 70°C or higher, from the viewpoint of storage stability of the scrubbing agent of the present invention. Furthermore, from the viewpoint of storage stability of the scrubbing agent of the present invention, the melting point of the fatty acid triglyceride contained as component (B) is preferably 95°C or lower. In the present invention, as the fatty acid triglyceride having a melting point of 50°C or higher, it may be produced and used by hydrogenating natural oils and fats or by a synthesis method known per se, but commercially available products provided by various companies can be used.

[0012] [Scrubbing agent] The scrubbing agent of the present invention is characterized by containing a total of 90% by mass or more of the above component (A) and component (B) based on the total amount of the scrubbing agent. If the total content of component (A) and component (B) is less than 90% by mass, the storage stability of the scrubbing agent may deteriorate. From the viewpoint of storage stability, the scrubbing agent of the present invention preferably contains a total of 95% by mass or more of component (A) and component (B). The content ratio [(A):(B)] of component (A) and component (B) in the scrubbing agent of the present invention is 90:10 to 10:90 in terms of mass ratio. If the content ratio of component (A) and component (B) is outside the above range, the storage stability of the scrubbing agent may deteriorate. From the viewpoint of the storage stability of the scrubbing agent, the content ratio [(A):(B)] of component (A) and component (B) is preferably 79:21 to 21:79 in terms of mass ratio, and more preferably 68:32 to 32:68.

[0013] [Components other than component (A) and component (B)] The scrubbing agent of the present invention may contain components other than the above component (A) and component (B) in an amount of 10% by mass or less based on the total amount of the scrubbing agent of the present invention. From the viewpoint of the storage stability of the scrubbing agent of the present invention, the content of components other than component (A) and component (B) is preferably 5% by mass or less based on the total amount of the scrubbing agent of the present invention. Examples of the components other than the above component (A) and component (B) include free fatty acids, fatty acid diglycerides, fatty acid monoglycerides, etc. contained as impurities in the fatty acid triglyceride of component (B). Further, within a range not impairing the characteristics of the present invention, synthetic hydrocarbon waxes and the like may be contained. In addition, commercially available products can be used for synthetic hydrocarbon waxes and the like.

[0014] [Melting point of the scrubbing agent of the present invention] From the perspective of the storage stability of the scrub agent, the melting point of the scrub agent of the present invention is preferably 50°C or higher, more preferably 60°C or higher, and even more preferably 70°C or higher. Also, from the perspective of the storage stability of the scrub agent, the melting point of the scrub agent of the present invention is preferably 95°C or lower.

[0015] [Shape of the scrub agent of the present invention] The shape of the scrub agent of the present invention is not particularly limited as long as it can function as a scrub agent. For example, it may be any shape such as spherical, elliptical, polyhedral, scaly, flaky, plate-shaped, rod-shaped, needle-shaped, etc., but spherical or polyhedral is preferred. Also, from the perspective of the storage stability of the scrub agent, it is preferable that the sphericity calculated as follows is 0.1 to 0.8. In this specification, the "sphericity" means, for images of any 10 or more scrub agent particles observed with an electron microscope, the value (α) calculated by dividing the minor axis of the particle by the major axis, and for the same particle, the minor axis measured from the image when the observation angle of the electron microscope is tilted by an arbitrary angle, divided by the major axis measured in the same way. The average of the values obtained by multiplying these two values is represented in the numerical range of 0.0 to 1.0. The closer the value is to 1.0, the closer the shape of the scrub agent is to a perfect sphere.

[0016] [Particle diameter of the scrub agent of the present invention] From the perspectives of the storage stability of the scrub agent and showing a stable scrub feeling when formulated in a cosmetic composition, the median diameter of the scrub agent of the present invention is 50 μm to 2000 μm. Here, the median diameter is the average particle diameter corresponding to 50% of the cumulative distribution curve based on volume. The median diameter of the scrub agent of the present invention can be determined from the particle diameter distribution measured by the laser diffraction / scattering method as described below. If the median diameter of the scrubbing agent of the present invention is outside the above range, the storage stability of the scrubbing agent may deteriorate, or it may not exhibit a stable scrubbing sensation. From the viewpoint of storage stability of the scrubbing agent and a stable scrubbing sensation when incorporated into a cosmetic composition, the median diameter of the scrubbing agent of the present invention is preferably 100 μm to 1000 μm, and more preferably 200 μm to 500 μm.

[0017] [Method for producing the scrubbing agent of the present invention] The scrubbing agent of the present invention can be manufactured by a generally known method. For example, component (A) and component (B), and optionally other components, can be melted and mixed at a temperature above their melting points, then sprayed into a spray cooling tower using a hollow cone nozzle, solidified to form spheroids, and classified to obtain a predetermined median diameter. Alternatively, a scrubbing agent having a predetermined median diameter can be manufactured by cooling and solidifying a similarly melted mixture of component (A), component (B), and optionally other components, then crushing it in a pulverizer to form polyhedrons and classifying them. In order to obtain a polyhedral shape that is desirable for the storage stability of the scrubbing agent, it is preferable to manufacture the scrubbing agent by crushing the molten mixture of component (A) and component (B), etc., which have been cooled and solidified, using a pulverizer.

[0018] The scrubbing agent of the present invention is prepared primarily from biodegradable materials such as linear saturated aliphatic monohydric alcohols and fatty acid triglycerides, thus having minimal environmental impact. It also exhibits excellent storage stability not only when incorporated into cosmetic compositions but also before incorporation, with minimal change in particle size due to load and impact during storage. Therefore, when incorporated into cosmetic compositions, it can stably provide a good scrubbing sensation and effectively exhibit cleansing effects such as removing dirt, sebum, and old keratin from the skin, as well as massage effects.

[0019] [Cosmetic composition] The present invention also provides a cosmetic composition containing the scrubbing agent of the present invention (hereinafter also referred to as "the cosmetic composition of the present invention" in this specification). The content of the scrubbing agent of the present invention in the cosmetic composition of the present invention can be appropriately set according to the use and form of the cosmetic composition of the present invention, as well as the purpose of use and shape of the scrubbing agent of the present invention. For example, it is preferably 0.1% to 20% by mass, and more preferably 1% to 10% by mass, based on the total amount of the cosmetic composition. When the content of the scrubbing agent of the present invention in the cosmetic composition of the present invention is within the above range, a good scrubbing sensation can be obtained. The cosmetic composition of the present invention can be provided as various cosmetic products, such as cleansing agents, facial cleansers (facial foam, shaving foam, etc.), hand washes (hand soap, etc.), body washes (body shampoo, etc.), hair washes (shampoo, etc.), packs (face packs, body packs, etc.), and massage products (facial massage products, body massage products, etc.), without any particular limitations as long as it can exhibit the function of the scrubbing agent of the present invention. Furthermore, the form of the cosmetic composition of the present invention is not particularly limited, but examples include liquid forms such as lotions and emulsions; semi-solid forms such as pastes, gels, and creams; and solid forms such as powders, granules, and cakes.

[0020] Depending on its form, the cosmetic composition of the present invention can be prepared by adding the scrubbing agent of the present invention to commonly used ingredients and using a method commonly used for the manufacture of a cosmetic composition of that form. Alternatively, the cosmetic composition of the present invention can be prepared by adding the scrubbing agent of the present invention after various forms of cosmetic compositions have been prepared and then uniformly mixing them. Ingredients that can be commonly used in preparing the cosmetic composition of the present invention include base components such as solvents (purified water, ethanol, etc.), oils (oils and fats, hydrocarbon oils, higher fatty acids, higher aliphatic alcohols, esters, etc.), surfactants, and thickeners; quality-preserving components such as alkaline agents, chelating agents, antioxidants, pH adjusters, preservatives, and bactericides; functional components such as moisturizers, anti-inflammatory agents, and vitamins; and palatability components such as fragrances and colorants. These can be used insofar as they do not impair the characteristics of the present invention. Furthermore, in the cosmetic composition of the present invention, scrubbing agents other than the scrubbing agent of the present invention may be appropriately selected and used insofar as they do not impair the characteristics of the present invention.

[0021] The cosmetic composition of the present invention contains the scrubbing agent of the present invention described above, has little impact on the environment, and the particle size of the scrubbing agent does not change much due to load or impact during storage, so it can stably exhibit a good scrubbing sensation. Furthermore, it can exhibit good cleansing effects such as the removal of dirt, sebum, and old keratin from the skin, as well as massage effects. [Examples]

[0022] The present invention will be described in more detail below with reference to examples.

[0023] [Examples 1-16, Comparative Examples 1-7] Scrub agents Table 1 shows the linear saturated aliphatic monohydric alcohols (components (A-1) to (A-5)) used to prepare the scrubbing agents for the examples and comparative examples, and Table 2 shows the fatty acid triglycerides (components (B-1) to (B-5)). A linear saturated aliphatic monohydric alcohol selected from (A-1) to (A-5) shown in Table 1 and a fatty acid triglyceride selected from (B-1) to (B-5) shown in Table 2 were melted and mixed at 120°C in the content ratio (mass ratio) shown in Table 3. After cooling and solidifying, the mixture was pulverized using a benchtop pulverizer ("Wonder Blender WB-1", Osaka Chemical Co., Ltd.) and classified to adjust to a predetermined median diameter, thereby obtaining the scrubbing agents of Examples 1 to 9, Examples 11 to 14, Comparative Examples 1 to 4, and Comparative Examples 6 and 7. The scrubbing agent for Example 10 was prepared by adding 5 parts by mass of synthetic wax ("C80N", Sasol) to a linear saturated aliphatic monohydric alcohol and fatty acid triglyceride in the proportions shown in Table 3 (total 95 parts by mass), melting and mixing at 120°C, then cooling and solidifying in the same manner as described above, and finally grinding. The scrubbing agent in Example 15 was prepared by melting and mixing a linear saturated aliphatic monohydric alcohol and a fatty acid triglyceride at 120°C in the content ratios shown in Table 3. The scrubbing agent in Example 16 was prepared by adding 5 parts by mass of synthetic wax ("C80N", Sasol Co.) to a total of 95 parts by mass of linear saturated aliphatic monohydric alcohol and fatty acid triglyceride at the content ratios shown in Table 3, and then melting and mixing them at 120°C. After melting and mixing, these were sprayed into a spray cooling tower ("ADL311S-A", Yamato Scientific Co., Ltd.) using the attached hollow cone nozzle, solidified into spheres, and then classified to prepare the final product. The scrubbing agent for Comparative Example 5 was prepared by adding 10 parts by mass of synthetic wax ("C80N", Sasol) to a total of 90 parts by mass of linear saturated aliphatic monohydric alcohols and fatty acid triglycerides in the proportions shown in Table 3, melting and mixing at 120°C, cooling and solidifying, and then grinding and classifying in the same manner as described above.

[0024] For the scrubbing agents of Examples 1-16 and Comparative Examples 1-7, the melting point and median diameter were measured as described below, and the sphericity was calculated, the shape was observed, and the storage stability and cleaning performance were evaluated. The melting points were also measured for the linear saturated aliphatic monohydric alcohols and fatty acid triglycerides used as raw materials, and are shown in Tables 1 and 2.

[0025] (1) Measurement of melting point In this invention, the melting point refers to the temperature at which an endothermic peak is observed during melting, as measured by a differential scanning calorimeter (DSC). The temperature at which the endothermic peak is observed during melting was confirmed using a differential scanning calorimeter "DSC7000" (Hitachi High-Tech Science Corporation) by performing the following procedure. First, 10 mg of the sample was weighed into an aluminum sample pan. The weighed sample was then heated to 200°C at a heating rate of 10°C / min in a measurement folder into which nitrogen was blown at a flow rate of 60 mL / min, and then cooled to 30°C at a cooling rate of 2°C / min to ensure a uniform thermal history of the sample. Next, the sample was heated from 30°C to 200°C at a heating rate of 10°C / min to obtain the DSC curve during heating. The melting point was defined as the temperature at which an endothermic peak was observed during this heating process. If two or more endothermic peaks were observed, the melting point was defined as the temperature at which the peak showing the largest endothermic amount was observed.

[0026] (2) Measurement of median diameter The median diameter of each scrubbing agent in the examples and comparative examples was measured as follows: 2.0 g of each scrubbing agent in the examples and comparative examples was placed in a 100 mL glass beaker, and 100 mL of ethanol was added to prepare the sample. The sample was supplied to a particle size distribution analyzer ("Microtrac MT-3000", Microtrac-Bell Co., Ltd.) to measure the particle size (principle: laser diffraction and scattering method). When an integrated distribution curve was created with the total volume of the powder sample being measured as 100%, the average particle diameter at the point corresponding to 50% of the integrated distribution curve was determined and defined as the median diameter.

[0027] (3) Calculation of the sphericity of the scrubbing agent For each scrubbing agent in the examples and comparative examples, 10 arbitrary particles were observed at 50x magnification using a scanning electron microscope ("JSM-IT300HR InTouchScope" (JEOL Ltd.)). The minor and major axes were measured for each particle image obtained at observation angles of 0 and 20 degrees. The value obtained by dividing the minor axis measured at an observation angle of 0 degrees by the major axis (α) was multiplied by the value obtained by dividing the minor axis measured at an observation angle of 20 degrees by the major axis (β), and the average value was calculated.

[0028] (4) Observation of the shape of the scrubbing agent The shape of each scrubbing agent in the examples and comparative examples was observed at 50x magnification using a scanning electron microscope ("JSM-IT300HR InTouchScope," JEOL Ltd.).

[0029] (5) Evaluation of storage stability The storage stability of the scrubbing agents in the examples and comparative examples was evaluated by assessing their load-bearing capacity and impact resistance, as follows. Here, "load-bearing capacity" refers to resistance to collapse or adhesion caused by loads applied during storage, such as by loading. "Impact resistance" refers to resistance to collapse or adhesion caused by vibrations or other impacts applied during the transportation of the scrubbing agent. (i) Load-bearing capacity 100g each of the scrubbing agents from Examples 1-16 and Comparative Examples 1-7 were placed in a cylindrical stainless steel container with a diameter of 6cm, and a cylindrical weight of 100g with a diameter of 5cm was placed on top. The container was left standing at 40°C for one week. One week later, each scrub agent was removed and crushed, and its median diameter was measured in the same way as before storage. Using the median diameter before storage (D50) and the median diameter after storage (D50a), the rate of change X was calculated according to the following formula (I). D50 The percentage (%) was calculated, and the load-bearing capacity was evaluated according to the following evaluation criteria. X D50 (%)=|D50a-D50| / D50*100 (I) <Evaluation Criteria> ◎:X D50 ≤10% 〇:10 <X D50 ≤20% ×: 20% <X D50

[0030] (ii) Impact resistance 100g each of the scrubbing agents from Examples 1-16 and Comparative Examples 1-7 were placed in a cylindrical stainless steel container with a diameter of 6cm and shaken at 40°C with a shaking width of 50mm and 100rpm for one week. One week later, each scrub agent was removed and crushed, and its median diameter was measured in the same way as before storage. Using the median diameter before storage (D50) and the median diameter after storage (D50b), the rate of change Y was calculated according to the following formula (II). D50 The percentage (%) was calculated, and the impact resistance was evaluated according to the following evaluation criteria. Y D50(%) = |D50b - D50| / D50 * 100 (II) <Evaluation Criteria> ◎: Y D50 ≤ 10% 〇: 10 < Y D50 ≤ 20% ×: 20% < Y D50

[0031] (6) Evaluation of detergency The detergency of the scrubbing agent was evaluated as follows, assuming the cleaning effect when the scrubbing agent was added to the cleaning liquid and used after being stored under conditions where load and impact were applied. (i) Preparation of cleaning liquid Each scrubbing agent of Examples 1 to 16 and Comparative Examples 1 to 7 was allowed to stand for 1 week under the same conditions as in the load resistance evaluation in (5)(i) above, and then shaken for 1 week under the same conditions as in the impact resistance evaluation in (5)(ii) above. Next, using the scrubbing agent that had undergone the above treatment, a cleaning liquid was prepared as follows. In Table 4, (1) to (4) and (7) were stirred and mixed at 80°C, then (5) was added dropwise and mixed. After visually confirming that the system was uniform, it was cooled to 40°C, and (6) was added while stirring, and stirring was continued until sufficient dispersion was achieved to prepare the cleaning liquid.

[0032] (ii) Evaluation of cleaning effect A total of 20 panelists, 10 men and 10 women, each took 1 g of each cleaning liquid prepared above in their hands, spread it well over the entire palm, applied it to the face, massaged it with their fingers for 30 seconds, and then rinsed it off with warm water at 40°C. Regarding the cleaning effect felt at that time, evaluation was carried out according to the following evaluation criteria. <Evaluation Criteria> 2 points: When it was felt that old cutin and sebum were very easily removed and there was a feeling of freshness. 1 point: When it was felt that old cutin and sebum were somewhat easily removed and there was a somewhat fresh feeling. 0 point: When it was felt that old cutin and sebum were difficult to remove and there was no feeling of freshness. Next, the total scores from the 20 participants were calculated, and the cleaning effectiveness was judged according to the following criteria. A "◎" or "○" rating was considered a passing grade. <Judgment criteria> ◎: Total score of 35 points or higher; indicates excellent cleaning effect. ○: Total score between 30 and 35 points; has good cleaning effect. △: Total score between 20 and 30 points; cleaning effect is slightly inferior. ×: Total score less than 20 points; poor cleaning effect.

[0033] (7) Results Table 3 shows the results of evaluations for the melting point, median diameter, sphericity, shape, storage stability, and cleaning performance of each scrubbing agent in the examples and comparative examples.

[0034] [Table 1]

[0035] [Table 2]

[0036] [Table 3]

[0037] [Table 4]

[0038] As shown in Table 3, the scrubbing agents of Examples 1 to 16 all exhibited good load-bearing capacity and impact resistance, and were evaluated as having good storage stability. Furthermore, their cleaning performance when added to detergents was also judged to be satisfactory. In particular, the scrubbing agents in Examples 3, 5, and 7 were evaluated as having excellent load-bearing capacity and impact resistance (◎), and also as having excellent cleaning effect (◎). The scrubbing agent of Example 3 contains 1-docosanol (behenyl alcohol) (A-3) as a linear saturated aliphatic monohydric alcohol with 22 carbon atoms, with a content of 98% by mass, and hydrogenated castor oil (B-1) as a fatty acid triglyceride, mainly composed of tri-12-hydroxystearate glyceride, with a melting point of 70°C or higher. The content ratio of these components [(A):(B)] is 35:65, for a total of 96.9% by mass. It has a median diameter of 347 μm, a sphericity of 0.3, a polyhedral shape, and a melting point of 70°C or higher. The scrubbing agent of Example 5 contains (A-3) as a linear saturated aliphatic monohydric alcohol and tristearate glyceride (B-2) as a fatty acid triglyceride with a melting point of 70°C or higher, in a mass ratio of (A):(B) of 35:65, totaling 98.1% by mass. It has a median diameter of 362 μm, a sphericity of 0.3, a polyhedral shape, and a melting point of 70°C or higher. The scrubbing agent of Example 7 contains (A-3) as a linear saturated aliphatic monohydric alcohol and a mixture (B-4) containing 80% by mass of hydrogenated castor oil mainly composed of tri-12-hydroxystearate glyceride and 20% by mass of tristearate glyceride, with a melting point of 70°C or higher, in a mass ratio of (A):(B) of 35:65, totaling 97.1% by mass. It has a median diameter of 341 μm, a sphericity of 0.3, a polyhedral shape, and a melting point of 70°C or higher.

[0039] On the other hand, the scrubbing agent of Comparative Example 1, which contains 1-tetradecanol (myristyl alcohol) (A-5) as a linear saturated aliphatic monohydric alcohol with 14 carbon atoms in 99% by mass and has a melting point of less than 50°C, and the scrubbing agent of Comparative Example 2, which contains trilauric acid glyceride (B-5) as a fatty acid triglyceride and has a melting point of less than 50°C, both had a melting point of less than 50°C and were evaluated as having poor load-bearing capacity and impact resistance (×), as well as poor cleaning performance (×). Comparative Example 3, a scrubbing agent containing the above-mentioned 1-docosanol (behenyl alcohol) (A-3) as a linear saturated aliphatic monohydric alcohol and the above-mentioned hydrogenated castor oil (B-1) as a fatty acid triglyceride, in a mass ratio of (A):(B) of 3:97, was evaluated as having good load-bearing capacity (〇), poor impact resistance (×), and somewhat poor cleaning performance (△). Comparative Example 4, a scrubbing agent containing the above-mentioned (A-3) and (B-1) in a mass ratio of (A):(B) of 97:3, was evaluated as having poor load-bearing capacity and impact resistance (×), and poor cleaning performance (×). Comparative Example 5, a scrubbing agent containing 1-docosanol (behenyl alcohol) (A-3) as a linear saturated aliphatic monohydric alcohol and glyceride tristearate (B-2) as a fatty acid triglyceride, but with a total content of less than 90% by mass, was also evaluated as having poor load-bearing capacity and impact resistance (×), and poor cleaning performance (×). Comparative Example 6, a scrubbing agent containing 1-docosanol (behenyl alcohol) (A-3) as a linear saturated aliphatic monohydric alcohol and glyceride tristearate (B-2) as a fatty acid triglyceride, was evaluated as having poor load-bearing capacity and cleaning performance (×) due to its median diameter being less than 50 μm, while Comparative Example 7, a scrubbing agent with a median diameter exceeding 2000 μm, was evaluated as having poor impact resistance and cleaning performance (×).

[0040] From the above measurement and evaluation results for each scrubbing agent in Examples 1 to 16 and Comparative Examples 1 to 7, it was suggested that a scrubbing agent containing a linear saturated aliphatic monohydric alcohol (component (A)) with 16 to 30 carbon atoms and a melting point of 50°C or higher, and a fatty acid triglyceride (component (B)) with a melting point of 50°C or higher, in a mass ratio of 90:10 to 10:90, totaling 90% by mass or more, with a median diameter of 50 μm to 2000 μm and a melting point of 50°C or higher, exhibits good storage stability as evaluated by load-bearing capacity and impact resistance, and also shows excellent cleaning performance when added to detergents. [Industrial applicability]

[0041] As described in detail above, the present invention provides a scrubbing agent that is prepared from a material with excellent biodegradability, has little impact on the environment, exhibits excellent storage stability not only when incorporated into a cosmetic composition but also before being incorporated into a cosmetic composition, and shows little change in particle size due to load or impact during storage. When incorporated into a cosmetic composition, the scrubbing agent of the present invention can stably provide a good scrubbing sensation and can effectively exhibit cleansing effects such as removing dirt, sebum, and old keratin from the skin, as well as massage effects. Furthermore, the present invention provides a cosmetic composition that is prepared from a material with excellent biodegradability, contains a scrubbing agent with excellent storage stability, has minimal environmental impact, and provides a stable and good scrubbing sensation. The cosmetic composition of the present invention can effectively exhibit cleansing effects such as the removal of dirt, sebum, and old keratin from the skin, as well as massage effects.

Claims

1. A scrubbing agent comprising (A) a linear saturated aliphatic monohydric alcohol having 16 to 30 carbon atoms and (B) a fatty acid triglyceride with a melting point of 50°C or higher, totaling 90% by mass or more of the total amount of the scrubbing agent, wherein the content ratio of component (A) to component (B) [(A):(B)] is 90:10 to 10:90 by mass ratio, and the median diameter is 50 μm to 2000 μm.

2. A cosmetic composition containing the scrubbing agent described in claim 1.

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