Cosmetic soft capsules

Abstract

The present invention provides a capsule that, when used as a cosmetic, quickly disappears when crushed by hand, providing a satisfying user experience. [Solution] The present invention provides a soft capsule comprising a liquid contents at room temperature and a coating that encloses the contents, The present invention relates to a soft capsule for cosmetics, characterized in that, in the particle size distribution of the film fragments obtained by crushing the soft capsule with a bead homogenizer, the particle size at which the cumulative frequency by volume is 90% is 1000 μm or less.

Description

[Technical Field]

[0001] This invention relates to soft capsules used in cosmetics. [Background technology]

[0002] Capsule formulations, in which pharmaceutical substances are coated with a film, are used in a variety of fields. For example, capsules are used in the cosmetics industry to separate the contents from the cosmetic ingredients to improve shelf life, to release fresh contents by disintegrating the capsule upon use, or to create a visually striking design by utilizing the coloring of the capsule's outer shell. Various types of capsules are used in different ways.

[0003] WO2018 / 043661 (Patent Document 1) proposes an agar-coated capsule comprising an oily component as its contents and an agar film covering the contents, with silica added to the agar film. This capsule provides a capsule that, when used in a cosmetic product containing capsules applied to the skin, does not break during storage, breaks easily when crushed by fingers after application to the skin, and leaves no gel residue from the capsule film on the skin or reduces the amount of gel residue from the capsule film. In Patent Document 1, the silica added to the agar film is described as an ingredient that smooths the skin when the agar film is crushed on the user's skin and imparts cleansing power to the cosmetic product. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] WO2018 / 043661 [Overview of the project] [Problems that the invention aims to solve]

[0005] When used as a cosmetic, users apply it with a very high degree of tactile sensation using their fingers. Therefore, even with conventional technology, a problem has been that the user has not always achieved a sufficiently satisfying feel or a satisfactory sense of capsule film disappearance. The present invention aims to solve this problem. Specifically, the present invention aims to provide a capsule in which, when used as a cosmetic, even if film fragments are formed by crushing with the fingers, the presence of these film fragments is less noticeable to the fingers, and the contents are more easily absorbed by the skin. [Means for solving the problem]

[0006] The inventors of this invention conducted extensive research to solve the above objective and found that the objective is achieved when the particle size at which the cumulative frequency based on volume in the particle size distribution of the capsule is 90% is 1000 μm or less, thus completing the present invention.

[0007] The present invention provides the following embodiments. [1] A soft capsule comprising a liquid contents at room temperature and a coating that encloses the contents, A soft capsule for cosmetics, characterized in that, in the particle size distribution of the film fragments obtained by crushing the soft capsule with a bead homogenizer, the particle size at which the cumulative frequency by volume is 90% is 1000 μm or less. [Effects of the Invention]

[0008] According to the present invention, when the particle size distribution of coating fragments obtained by crushing cosmetic soft capsules with a bead homogenizer is such that the cumulative frequency of the volume-based fragments is 90% and the particle size is 1000 μm or less, it is possible to make the presence of the coating fragments less noticeable to the hand after the soft capsules have disintegrated on the skin, and to make the contents more easily absorbed by the skin. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic longitudinal cross-sectional view showing one embodiment of the nozzle portion of the apparatus for manufacturing cosmetic soft capsules according to the present invention. [Figure 2] This figure illustrates the requirement in particle size distribution that "the particle size at which the cumulative frequency based on volume is 90% is 1000 μm or less," when the relationship between relative particle amount (volume %) and particle size (μm) in the particle size distribution follows a normal distribution. [Figure 3] This figure shows the volume-based particle size distribution measured in Examples 1-5 and Comparative Examples 1-2, plotted on a graph with the relative particle amount (volume %) on the vertical axis and particle size (μm) on the horizontal axis. [Figure 4] This figure shows the volume-based particle size distribution measured in Examples 6 to 8, with the relative particle amount (volume %) obtained on the vertical axis and particle size (μm) on the horizontal axis. [Modes for carrying out the invention]

[0010] The present invention provides a cosmetic soft capsule comprising a liquid content at room temperature and a coating that encloses the content. The above technical effect is achieved when the soft capsule is pulverized with a bead homogenizer, and the particle size at which the cumulative frequency by volume of the coating fragments obtained is 90% is 1000 μm or less.

[0011] Contents Soft capsules are used in cosmetics and consist of a liquid contents at room temperature and a coating that encloses the contents. The contents of soft capsules typically contain an oily liquid. The oily liquid may be a naturally derived liquid, a synthetically obtained liquid, or a mixture thereof. Such oily liquids are, for example, at least one selected from the group consisting of avocado oil, linseed oil, almond oil, olive oil, cocoa oil, beef tallow, tung oil, wheat germ oil, sesame oil, rice germ oil, rice bran oil, safflower oil, soybean oil, evening primrose oil, camellia oil, corn oil, rapeseed oil, horse fat, peach kernel oil, palm oil, palm kernel oil, castor oil, sunflower oil, lard, grape oil, jojoba oil, macadamia nut oil, mink oil, cottonseed oil, Japanese wax, coconut oil, peanut oil, lanolin, egg yolk oil, rosehip oil, and medium-chain triglycerides, but are not limited to the above, and any component can be used.

[0012] The above-mentioned content may contain beauty ingredients. The beauty ingredients may be any ingredients generally used for beauty and skin care purposes in cosmetics. For example, vitamin components such as vitamin C and vitamin E, moisturizing components such as hyaluronic acid, ceramide, and collagen, and whitening components such as tranexamic acid and arbutin can be mentioned. The beauty ingredients are not limited to the above, and any ingredients can be used, and one or more beauty ingredients can be used. The beauty ingredients can be incorporated into the oily liquid which is the content, or can be made compatible with the oily liquid by modification or using other ingredients so as to be incorporated. For example, an aqueous component or a hydrophilic component may be incorporated into the oily liquid using a surfactant.

[0013] In the soft capsule of the present invention, the amount of the beauty ingredient is usually 1 to 50% by weight, preferably 5 to 30% by weight, more preferably 10 to 20% by weight based on the total amount of the content of the soft capsule. If it is more than 50% by weight, encapsulation may be difficult, and if it is less than 1% by weight, the effect of the active substance may not occur.

[0014] In the content of the soft capsule of the present invention, formulation agents such as excipients, stabilizers, adjuvants or foaming agents may be appropriately formulated. The amounts of these formulation agents are not particularly limited, but should not be amounts that inhibit the function of the soft capsule of the present invention. The content of the soft capsule of the present invention may contain silica. Silica is said to improve the firmness and gloss of the skin.

[0015] coating The film of the soft capsule of the present invention can contain the content and can be disintegrated by hand on the skin, and moreover, when it is ground with a finger after disintegration, the presence of film pieces is difficult to feel or not felt by hand. The film of the soft capsule usually contains a water-soluble polymer, a polyol and water. By containing a polyol, the film pieces tend to become finer.

[0016] The water-soluble polymer is a component for forming a film, and is selected from, for example, gelatin, casein, zein, pectin or its derivatives, alginic acid or its salts, agar, gellan gum, carrageenan, farselellan, chitosan, curdlan, starch, modified starch, pullulan, mannan, and mixtures thereof. Among these, the water-soluble polymer is preferably agar, with a jelly strength of 400 g / cm 2 , 2 ,

[0017] , 2 , , 2 , 2 , , 2 , 2 , 2 , 2 , 2 , 2 or more preferably the above-mentioned agar. When the water-soluble polymer is agar, after the soft capsule is disintegrated on the skin, it becomes difficult to feel the presence of the film pieces by hand, and the content becomes more compatible with the skin. Also, when the water-soluble polymer is agar with a jelly strength of 400 g / cm 2 or more, it is easier to obtain the shape retention of the capsule. The upper limit of the jelly strength of agar is not particularly limited, but from the perspective of easy availability, the jelly strength may be 2500 g / cm 2 or less. Specific examples of the jelly strength are 400 g / cm 2 , 500 g / cm 2 , 600 g / cm 2 , 700 g / cm 2 , 800 g / cm 2 , 900 g / cm 2 , 1000 g / cm 2 ​​​​​​​​​​​​​​​​The water-soluble polymers used in the present invention are not limited to these. These water-soluble polymers are present in an amount of 5% to 20% by weight, preferably 15% by weight or less, based on the total solid content weight of the soft capsule coating. When using alginates (especially sodium alginate), gellan gum, pectin, or carrageenan as a curing aid or viscosity modifier, alkali metal salts, alkaline earth metal salts, ammonium salts, etc., may be added as appropriate.

[0018] The coating contains water, as described above. The water is the component that keeps the soft capsule moist and is, for example, at least one selected from the group consisting of tap water, deionized water, distilled water, and ultrapure water. The amount of water is 60% by weight or more based on the total weight of the coating.

[0019] The polyol incorporated into the coating of the soft capsule of the present invention is also called a polyhydric alcohol because it has multiple hydroxyl groups in one molecule. The polyol is a water-soluble compound. The molecular weight of the polyol is 1000 or less, preferably 500 or less. There is no particular lower limit to the molecular weight of the polyol, but the molecular weight of the polyol may be 90 or more. The polyol is, for example, at least one selected from the group consisting of butylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, sorbitol, glucose, trehalose, and polyethylene glycol, but is not limited to the above, and any component can be used.

[0020] The amount of polyol in the coating is within the range of 5 to 10 parts by weight, assuming the weight of the coating is 100 parts by weight. When the amount of polyol is within the above range, after the soft capsule is disintegrated on the skin, the presence of the coating fragments becomes less noticeable to the hand, and the contents are more easily absorbed by the skin. Furthermore, it is preferable that the amount of polyol in the coating is 40% by weight or more, based on the total solid content weight of the soft capsule coating. In this case, the upper limit of the amount of polyol is not particularly limited as long as a soft capsule can be formed, but the amount of polyol may be, for example, 95% by weight or less. Specific examples of polyol amounts are 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 83%, 85%, 90%, 92%, and 95%, and may be within the range of any two of these values. When the polyol content is 40% by weight or more, it not only imparts flexibility to the film to make it easier to disintegrate the soft capsule during use, but also reduces the amount of residue left when crushed by hand. If the film becomes too soft, the polyol content can be reduced to, for example, 90% by weight or less. In one embodiment of the present invention, it is preferable that the polyol content is 2 times or more the amount of water-soluble polymer. The polyol content may be 3 times or more, 5 times or more, 7 times or more, or 9 times or more by mass ratio of the amount of water-soluble polymer. When the polyol content is 2 times or more the amount of water-soluble polymer, after disintegrating the soft capsule on the skin, the presence of film fragments becomes less noticeable to the hand, and the contents become more easily absorbed by the skin. The upper limit of the polyol content is not particularly limited as long as a film can be formed, but for example, it is 20 times or less. The polyol content may be 17 times or less, 15 times or less, 12 times or less, or 10 times or less the amount of water-soluble polymer.

[0021] The coating of the soft capsule of the present invention may, if necessary, contain various additives commonly used in this field, such as fragrances, sweeteners, colorants, and preservatives such as parabens, in addition to the above coating composition. When such additives are used, the total content of all additives is, for example, 0.01% to 10% by weight, preferably 0.1% to 5% by weight, relative to the total solid content weight of the composition that forms the capsule coating. In the present invention, the coating of the soft capsule does not necessarily have to contain poorly water-soluble particles. Poorly water-soluble particles are particles composed of substances that are poorly soluble in water. Examples of substances that constitute poorly water-soluble particles include inorganic substances such as zirconia and silica, and organic substances such as melamine and acrylic. If the coating contains poorly water-soluble particles, after grinding the coating, the poorly water-soluble particles may remain on the skin, potentially causing discomfort such as a powdery feeling. In particular, if the soft capsule is a seamless capsule, poorly water-soluble particles are likely to clog the coating liquid described later as it passes through the multi-layer nozzle, potentially making it difficult to form a seamless capsule.

[0022] The coating of the soft capsule of the present invention preferably has a thickness of 10 to 1000 μm, preferably 30 to 500 μm, and more preferably 50 to 250 μm. If the thickness of the coating is less than 10 μm, the coating strength tends to be low, and if it exceeds 1000 μm, the amount of contents decreases and the disintegration properties tend to worsen.

[0023] The size of the soft capsules of the present invention is not particularly limited, but it is desirable that they have a diameter of 0.3 to 10 mm, preferably 1 to 8 mm. If the diameter of the capsule is less than 0.3 mm, the amount of ingredients that can be incorporated into the contents tends to be small, and if it exceeds 10 mm, it takes a long time to crush.

[0024] Since the soft capsules of the present invention are intended to be used in a dispersed state within a continuous phase mainly composed of water, it is preferable that the capsules be in a moist state. In such moist capsules, it is preferable that the coating contains 60% by weight or more of water relative to its total weight. The continuous phase refers to the phase outside the soft capsule when the soft capsule is present within the continuous phase, and refers to the main body of the cosmetic formulation (formulation other than the soft capsule).

[0025] Other layers The soft capsule of the present invention basically consists of two layers: the contents and the coating. However, depending on the nature of the contents, one or more intermediate layers may be provided between the contents and the coating. The intermediate layers may be present to adversely affect the coating or inhibit the solubility of the contents.

[0026] The intermediate layer uses oils and fats with a melting point of 45°C or higher. These oils and fats with a melting point of 45°C or higher are selected from the aforementioned oils and fats with a melting point of 40°C or higher. Specific examples of oils and fats with a melting point of 45°C or higher include the above-mentioned vegetable (fractionated) oils and fats, beeswax, highly hardened oils, margarine, and shortening.

[0027] Lecithin or silicon dioxide may be added to the intermediate layer to adjust the interfacial tension, viscosity, and specific gravity. There are no particular restrictions on the amount of these additives, but they must not be in an amount that inhibits the function of the soft capsule of the present invention.

[0028] Soft capsule manufacturing method The soft capsules of the present invention may be manufactured by any method, but below, the manufacturing method of the soft capsules will be described, with the example of a seamless capsule.

[0029] The soft capsules of the present invention are typically manufactured using a dropper method employing multiple nozzles, specifically a method in which the capsules are dropped into a cooling liquid using a double-layer nozzle. Figure 1 is a schematic longitudinal cross-sectional view showing one aspect of the nozzle section of an apparatus for manufacturing soft capsules (i.e., seamless capsules) of the present invention.

[0030] In Figure 1, the soft capsule manufacturing apparatus uses a dropper method with a double nozzle 100. In the double nozzle 100, the liquid contents are discharged from the inner nozzle 120, and the coating liquid is discharged from the outer nozzle 110. If there is an intermediate layer between the coating and the contents, another nozzle may be added, and soft capsules may be manufactured using a three-layer nozzle including the intermediate nozzle. During discharge, the liquids are simultaneously extruded at a constant speed into a cooling liquid flowing at a steady rate to form a composite jet, which is then released into the cooling liquid. The surface tension acting between the cooling liquid and the coating liquid allows for the continuous manufacture of soft capsules 10. In Figure 1, the soft capsule 10 consists of a coating 11 and contents 12.

[0031] In the manufacturing of the soft capsules of the present invention, when a two-layer nozzle is used as shown in Figure 1, the resulting capsule has a two-layer structure, and when a three-layer nozzle is used (not shown), the resulting capsule has a three-layer structure. In both such two-layer and three-layer capsules, the contents are present as the innermost layer.

[0032] Immediately after preparing the soft capsules in the coolant as described above, the coolant adheres to the outer surface of the soft capsules. Therefore, it is preferable that a separation step is performed in the soft capsule manufacturing method to separate the soft capsules from the coolant. Furthermore, this manufacturing method does not necessarily have to include a drying step.

[0033] Particle size distribution of soft capsule coating fragments The soft capsules obtained by the above method require that, as mentioned earlier, the particle size at which the cumulative frequency of the film fragments obtained by crushing with a bead homogenizer is 1000 μm or less, based on volume. This makes it less likely for users to feel the presence of the film fragments when crushing the soft capsules with their fingers during use, and allows the contents to be more easily absorbed by the skin. In other words, by having a film with a particle size of 1000 μm or less at the 90% cumulative frequency of volume, the film is more easily broken down into smaller pieces when the soft capsules are crushed with the fingers. Therefore, the presence of the film fragments is less likely to be felt during use, and the contents are more easily absorbed by the skin. Note that the particle size distribution of the film fragments described above is a physical property of the film indicating how easily the film breaks down into smaller pieces, and does not necessarily have to match the particle size distribution of the film fragments obtained by crushing the film on the skin during use.

[0034] When pulverizing soft capsules with a bead homogenizer, the soft capsules and beads are placed together inside the homogenizer tube. The vibrations of the bead homogenizer cause the beads to collide with the soft capsules, thereby pulverizing them. The conditions for pulverizing the soft capsules are a vibration frequency of 18.0 Hz and a pulverization time of 90 seconds.

[0035] The beads described above only need to be able to crush the soft capsules, and the material and particle size of the beads are not particularly limited. Examples of bead materials include ceramics, glass, or metals such as stainless steel. The particle size of the beads may also be larger than the particle size of the soft capsules. When the beads are larger than the soft capsules, the particle size of the beads can be, for example, 4 to 5 times that of the soft capsules. For example, if the particle size of the soft capsules is 1.5 mm, the particle size of the beads can be 6.3 to 7.8 mm.

[0036] In this invention, as described above, it is necessary that the particle size at which the cumulative frequency based on volume reaches 90% in the particle size distribution of the coating fragments is 1000 μm or less. Generally, the particle size distribution is represented by a graph with particle size (μm) on the horizontal axis and particle amount (frequency) (volume %) on the vertical axis, and the particle size at the point where the cumulative volume of the curve reaches 90% of the total is the "particle size at which the cumulative frequency based on volume reaches 90%." For example, Figure 2 shows a case where the relative particle amount (frequency) is displayed in volume % on the vertical axis and the particle size is on the horizontal axis, and these are assumed to follow a normal distribution for explanatory purposes. In Figure 2, this can be determined by accumulating the particle size from the smallest particle size on the curve and taking the particle size when the volume % reaches 90%. In this invention, it is necessary that the particle size at which the cumulative frequency based on volume reaches 90% is 1000 μm or less (i.e., 1 mm or less). When the particle size at which the cumulative frequency by volume is 90% exceeds 1000 μm, the coating does not easily break down into smaller pieces, resulting in a lingering residue even after grinding with fingers. The particle size at which the cumulative frequency by volume is 90% is preferably 960 μm or less. The particle size at which the cumulative frequency by volume is 90% may also be 950 μm or less, 940 μm or less, 930 μm or less, 920 μm or less, 910 μm or less, or 900 μm or less. The particle size will never be 0 μm, but smaller is better, and around 100 μm is sufficient. The particle size at which the cumulative frequency by volume is 90% may be 200 μm or larger, 300 μm or larger, 400 μm or larger, 500 μm or larger, 600 μm or larger, 700 μm or larger, 800 μm or larger, 850 μm or larger, or 890 μm or larger.

[0037] In the above, soft capsules were described as seamless capsules, but soft capsules are not limited to seamless capsules and may also be capsules obtained by a rotary method. When a rotary method is used in the manufacture of soft capsules, the manufacturing equipment and its conditions can be selected arbitrarily.

[0038] [Examples] The present invention will be described in more detail by reference to examples. The present invention should not be construed as being limited to these examples. In the examples, all references such as "parts" and "%" are based on weight or by weight.

[0039] Example 1 Agar A (jelly strength of 610-650 g / cm³) 2 1.3 parts by weight of agar, 0.6 parts by weight of sodium alginate, 10.0 parts by weight of 1,3-butylene glycol, and 88.1 parts by weight of deionized water were mixed and heated in an autoclave at 105°C for 10 minutes to dissolve and prepare a coating solution.

[0040] The above coating liquid and medium-chain fatty acid triglyceride as the contents liquid were introduced into a seamless capsule manufacturing apparatus equipped with a concentric double nozzle. The contents liquid was loaded into the inner nozzle of the double nozzle, and the above coating liquid was loaded into the outer nozzle. The contents liquid temperature was set to 20°C and the coating liquid temperature to 70°C, and these were dispensed into the flowing medium-chain fatty acid triglyceride (10°C) to produce seamless capsules with a particle size of 1.5 mm.

[0041] After degreasing the obtained seamless capsules, a cosmetic product was prepared by immersing 75 parts by weight of the seamless capsules in 25 parts by weight of a continuous phase (a mixture of 4.0 parts by weight of 1,3-butylene glycol, 1.0 part by weight of glycerin, 0.1 parts by weight of phenoxyethanol, and 94.9 parts by weight of deionized water).

[0042] Measurement of particle size distribution and crushing of seamless capsules For the seamless capsules described above, the capsules removed from the cosmetics obtained in the examples were pulverized according to the following procedure to obtain pulverized film material. The particle size distribution of the pulverized film material was then measured, and the particle size at which the cumulative frequency by volume was 90% was determined as follows.

[0043] In a microtube (specifically, an AS ONE GDMST-2ML) containing two glass beads (Sansho Glass Beads No. 7, approximately 0.9g) and 0.2g of seamless capsules, the tube was placed in a bead homogenizer (Qiagen TissueLyser II), capped, and set in the bead homogenizer. The seamless capsules were then pulverized under conditions of a frequency of 18.0Hz and a duration of 90 seconds. After pulverization, the film fragments were washed once with 0.5mL of ethanol and twice with 0.5mL of hexane to obtain a film fragment sample. The above process was repeated to obtain 3g of film fragment sample.

[0044] The obtained film fragment samples were measured using a laser diffraction scattering particle size distribution analyzer (SALD-2300, Shimadzu Corporation) under wet conditions in ethanol, determining the volume-based particle size distribution and the average diameter (or particle size at 90% cumulative frequency). The volume-based particle size distribution was plotted on a graph with the measured values ​​on the vertical axis representing relative particle amount (volume %) and the horizontal axis representing particle size (μm), and is shown in Figure 3. Furthermore, the obtained capsules were subjected to the following sensory evaluation.

[0045] <Sensory evaluation> A 0.1g capsule was placed on the back of one hand, and the capsule and its coating were crushed in a circular motion using the fingertips of the other hand. A sensory evaluation was then performed according to the following criteria. -: It takes more than 30 seconds for the capsule to completely break open, the size of the remaining film fragments is larger than the particle size (1.5 mm), and the presence of the film fragments can be felt by hand, so there is no improvement in how well the contents adhere to the skin. +: It took 15-30 seconds for the capsule to completely break, the size of the remaining film fragments was less than the particle size (1.5 mm), the presence of the film fragments was difficult to feel with the hand, and an improvement in the feel of the contents against the skin was observed. ++: All capsules broke within 15 seconds, the size of the remaining film fragments was less than the particle size (1.5 mm), the presence of the film fragments was difficult to feel with the hand, and an improvement in the feel of the contents against the skin was observed.

[0046] Table 1 shows the results of the sensory evaluation using capsules. Table 1 also includes the film formulation, the mass ratio of polyol / water-soluble polymer, and the particle size and film thickness (μm) at which the cumulative frequency by volume reaches 90%.

[0047] Examples 2-5 and Comparative Examples 1-2 The capsule coating solution was prepared using the formulation shown in Table 1, and seamless capsules and cosmetics were manufactured in the same manner as in Example 1. Similar to Example 1, particle size measurements and sensory evaluations were performed to determine the cumulative frequency by volume of 90%, and the results are shown in Table 1. Note that the agar B listed in Table 1 has a gel strength of 900-1000 g / cm³. 2 This is agar. Also, in Table 1, Sodium alginate is sodium alginate, 1,3-BG is 1,3-butanediol, and PG is 1,2-propanediol. Furthermore, similar to Example 1, the particle size distribution of each example and comparative example is shown in Figure 3, with relative particle amount (volume %) on the vertical axis and particle size (μm) on the horizontal axis.

[0048] Examples 6-8 The capsule coating solution was prepared using the formulation shown in Table 2, and seamless capsules and cosmetics were manufactured in the same manner as in Example 1. Similar to Example 1, the particle size at which the cumulative frequency by volume reached 90% was measured, and sensory evaluation was performed. The results are shown in Table 2. Table 2 also includes the polyol / water-soluble polymer mass ratio and coating thickness, similar to Table 1. Note that the agar C listed in Table 2 has a gel strength of 1800 g / cm². 2 This is agar. Also, similar to Example 1, the particle size distribution of each example is shown in Figure 4, with the relative particle amount (volume %) on the vertical axis and the particle size (μm) on the horizontal axis.

[0049] The jelly strength was measured using a method compliant with the Japanese Agar Water formula. Specifically, a 1.5 wt% agar solution was boiled and allowed to stand at 20°C for 15 hours, and the jelly that solidified was measured at 1 cm². 2 This refers to the maximum weight that can be withstood for 20 seconds.

[0050] [Table 1]

[0051] [Table 2] In Examples 1-8, the particle size of the coating fragments with a cumulative volume-based frequency of 90% in the particle size distribution was 1000 μm or less. As a result, the sensory evaluation in the sensory test when crushing the capsule was all + or ++, the capsule broke early, and the presence of the coating fragments was difficult to feel by hand. The performance is superior when the polyol / water-soluble polymer mass ratio is greater than the amount of water-soluble polymer. On the other hand, in Comparative Examples 1 and 2, the particle size of the coating fragments with a cumulative volume-based frequency of 90% in the particle size distribution exceeded 1000 μm. As a result, the sensory test evaluation was "-", the capsule disintegration took more than 30 seconds, the coating fragments (residue) were large, and a good user experience could not be obtained. Comparative Examples are examples where polyol is not present. [Industrial applicability]

[0052] When used in cosmetics, the soft capsules of the present invention reduce the time required to crush the capsules during use and eliminate the presence of coating fragments, resulting in a significantly improved user experience. The soft capsules of the present invention allow for the incorporation of ingredients with functions separate from or enhancing the functions of the cosmetic product. Users can then pick up the capsule, crush it with their fingers, and release the functional ingredients, thereby improving the functionality of the cosmetic product. The soft capsules of the present invention may also serve as colorants, allowing for the adjustment of the cosmetic's color.

[0053] [Modes of the Invention] [1] A soft capsule comprising a liquid contents at room temperature and a coating that encloses the contents, A soft capsule for cosmetics, characterized in that, in the particle size distribution of the film fragments obtained by crushing the soft capsule with a bead homogenizer, the particle size at which the cumulative frequency by volume is 90% is 1000 μm or less. [2] The contents of the cosmetic soft capsule are an oily liquid, as described in [1]. [3] The coating comprises a water-soluble polymer and a polyol, and is a cosmetic soft capsule according to [1] or [2]. [4] The amount of the polyol is in the range of 5 to 10 parts by weight when the weight of the coating is 100 parts by weight, as described in any of [1] to [3], for cosmetic soft capsules. [5] The cosmetic soft capsule according to any one of [1] to [4], wherein the polyol is at least one component selected from the group consisting of butylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, sorbitol, glucose, trehalose, and polyethylene glycol. [6] The soft capsule is a cosmetic soft capsule according to any one of [1] to [5], wherein the moisture content of the coating is 60% by weight or more. [7] The soft capsule is a seamless capsule, as described in any of [1] to [6] for cosmetic use. [8] In the grinding process using the aforementioned bead homogenizer, The vibration frequency is 18.0 Hz, and the grinding time is 90 seconds. The beads used to crush the soft capsule are glass beads. The particle size of the glass beads is larger than the particle size of the soft capsule. A cosmetic soft capsule as described in any of [1] to [7].

[0054] [Explanation of symbols] 10: Soft capsules 11: Coating 12:Contents 100; Dual nozzle 110: Outer nozzle 120: Inner nozzle

Claims

1. A soft capsule comprising a liquid contents at room temperature and a coating that encloses the contents, A soft capsule for cosmetics, characterized in that, in the particle size distribution of the film fragments obtained by crushing the soft capsule with a bead homogenizer, the particle size at which the cumulative frequency by volume is 90% is 1000 μm or less.

2. The cosmetic soft capsule according to claim 1, wherein the contents are an oily liquid.

3. The coating contains a water-soluble polymer and a polyol, as described in claim 1 or 2, for use as a cosmetic soft capsule.

4. The amount of the polyol is in the range of 5 to 10 parts by weight when the weight of the coating is 100 parts by weight, as described in claim 3, for a cosmetic soft capsule.

5. The cosmetic soft capsule according to claim 3 or 4, wherein the polyol is at least one component selected from the group consisting of butylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, sorbitol, glucose, trehalose, and polyethylene glycol.

6. The soft capsule is a cosmetic soft capsule according to any one of claims 1 to 5, wherein the moisture content of the coating is 60% by weight or more.

7. The soft capsule is a seamless capsule, as described in any one of claims 1 to 6.

8. In the grinding process using the aforementioned bead homogenizer, The vibration frequency is 18.0 Hz, and the grinding time is 90 seconds. The beads used to crush the soft capsule are glass beads. The particle size of the glass beads is larger than the particle size of the soft capsule. A soft capsule for cosmetics according to any one of claims 1 to 7.

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