Soft capsule for cosmetic use

Abstract

The purpose of the present invention is to provide a capsule that, when used as a cosmetic, rapidly disappears when crushed by the fingers and that provides a user with a sense of satisfaction.　The present invention relates to a soft capsule for cosmetic use, the soft capsule comprising: content that is liquid at room temperature; and a film that envelopes the content. The soft capsule is characterized in that in the particle distribution of film pieces which are obtained by crushing the soft capsule with a bead-type homogenizer, the particle diameter at which the cumulative frequency on the volume basis is 90% is 1000 μm or less.

Description

Cosmetic soft capsules

[0001] The present invention relates to a soft capsule used in cosmetics.

[0002] Capsule preparations in which drug substances are coated with a film are used in various fields. For example, capsules are used in the field of cosmetics, where various capsules are used in various ways, such as separating the capsule contents from cosmetic ingredients to increase shelf life, breaking the capsule to release fresh contents when used, or using colored capsule shells to create a moving design impact.

[0003] WO 2018 / 043661 (Patent Document 1) proposes an agar-coated capsule comprising an oily content and an agar coating covering the content, with silica blended into the agar coating. This capsule provides a capsule that, when used with a cosmetic product containing the capsule to be applied to the skin, does not break during storage, is easily broken when applied to the skin and is easily crushed with the fingers, and leaves no or reduced gel residue from the capsule coating on the skin. Patent Document 1 describes the silica added to the agar coating as an ingredient that smooths the skin and imparts cleansing power to the cosmetic product when the agar coating is crushed on the user's skin.

[0004] WO2018 / 043661

[0005] When used as a cosmetic, users rely on a very high level of sensitivity with their fingers, and the prior art has not necessarily achieved a fully satisfactory feel for users, nor a satisfactory feeling of capsule shell disappearance. The present invention aims to solve this problem. That is, the present invention aims to provide a capsule that, even if shell fragments are formed by grinding with fingers when used as a cosmetic, makes the presence of the shell fragments less noticeable with the fingers, and makes the contents more easily absorbed into the skin.

[0006] As a result of extensive research to achieve the above object, the inventors have found that the above object can be achieved when the particle diameter at which the volume-based cumulative frequency of 90% in the particle size distribution of capsules is 1000 μm or less, and have thus completed the present invention.

[0007] The present invention provides the following aspects: [1] A soft capsule for cosmetics comprising a liquid content at room temperature and a shell encapsulating the content, wherein the particle size distribution of the shell fragments obtained by pulverizing the soft capsule with a bead homogenizer has a particle size of 1000 μm or less at a cumulative frequency of 90% on a volume basis.

[0008] According to the present invention, when the particle size distribution of the membrane fragments obtained by crushing cosmetic soft capsules with a bead homogenizer has a particle size of 1000 μm or less, which corresponds to a cumulative frequency of 90% on a volume basis, after the soft capsules are disintegrated on the skin, the presence of the membrane fragments becomes difficult to feel with the hand, and the contents become more easily absorbed into the skin.

[0009] 1 is a schematic longitudinal cross-sectional view showing one embodiment of a nozzle portion of an apparatus for producing cosmetic soft capsules according to the present invention.

[0023] FIG. 1 is a diagram illustrating the relationship between the relative particle amount (volume %) and particle size (μm) in the particle size distribution in the case of a normal distribution, for explaining the requirement that "the particle size at which the volume-based cumulative frequency is 90% is 1000 μm or less" in the particle size distribution.

[0024] FIG. 1 is a graph showing the volume-based particle size distributions measured in Examples 1 to 5 and Comparative Examples 1 and 2, with the obtained relative particle amount (volume %) on the vertical axis and particle size (μm) on the horizontal axis.

[0025] FIG. 1 is a graph showing the volume-based particle size distributions measured in Examples 6 to 8, with the obtained relative particle amount (volume %) on the vertical axis and particle size (μm) on the horizontal axis.

[0010] The present invention provides a soft capsule for cosmetics that has a liquid content at room temperature and a shell that encapsulates the content. The soft capsule achieves the above technical effects when the particle size distribution of the shell fragments obtained by pulverizing the soft capsule with a bead homogenizer has a particle size of 1000 μm or less, at which a cumulative frequency of 90% by volume is obtained.

[0011] Soft capsules are used in cosmetics and contain a liquid content at room temperature and a shell that encases the content. The soft capsule content usually contains an oily liquid. The oily liquid may be a naturally occurring liquid, a synthetic 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, cacao 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, persic oil, palm oil, palm kernel oil, castor oil, sunflower oil, lard, grape oil, jojoba oil, macadamia nut oil, mink oil, cottonseed oil, Japan wax oil, coconut oil, peanut oil, lanolin, egg yolk oil, rosehip oil, and medium-chain fatty acid triglycerides. However, the oily liquids are not limited to the above, and any other component may be used.

[0012] The contents may contain a cosmetic ingredient. The cosmetic ingredient may be any ingredient generally contained in cosmetics for the purpose of beauty or skin beautification, such as vitamin ingredients such as vitamin C and vitamin E, moisturizing ingredients such as hyaluronic acid, ceramide, and collagen, and whitening ingredients such as tranexamic acid and arbutin. The cosmetic ingredient is not limited to the above, and any ingredient can be used, and one or more cosmetic ingredients can be used. The cosmetic ingredient can be blended into the oily liquid that is the contents, or can be modified or made blendable with other ingredients to make it blendable into the oily liquid. For example, an aqueous component or hydrophilic component can be blended into the oily liquid using a surfactant.

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

[0014] The contents of the soft capsule of the present invention may further contain additives such as excipients, stabilizers, adjuvants, or foaming agents. The amount of these additives is not particularly limited, but should not be an amount that inhibits the function of the soft capsule of the present invention. The contents of the soft capsule of the present invention may also contain silica. Silica is said to improve the firmness and luster of the skin.

[0015] The soft capsule shell of the present invention is capable of containing the contents, allowing the soft capsule to be broken down by hand on the skin, and after the breakup, when the soft capsule is crushed with the fingers, the presence of the shell fragments is hardly or not felt by hand. The soft capsule shell usually contains a water-soluble polymer, a polyol, and water. The inclusion of a polyol makes it easier to break down the shell fragments.

[0016] The water-soluble polymer is a film-forming component, and is selected from, for example, gelatin, casein, zein, pectin or a derivative thereof, alginic acid or a salt thereof, agar, gellan gum, carrageenan, furcellaran, chitosan, curdlan, starch, modified starch, pullulan, mannan, and mixtures thereof. Among these, the water-soluble polymer is preferably agar, and the water-soluble polymer is a component having a jelly strength of 400 g / cm. ２ It is more preferable that the water-soluble polymer is agar or agar having a jelly strength of 400 g / cm or more. When the water-soluble polymer is agar, after the soft capsule is disintegrated on the skin, the presence of the membrane pieces is hardly felt by hand, and the contents are easily absorbed into the skin. In addition, the water-soluble polymer is agar or agar having a jelly strength of 400 g / cm or more. ２ When the agar is above this level, the capsules are more likely to retain their shape. The upper limit of the jelly strength of the agar is not particularly limited, but in terms of availability, a jelly strength of 2500 g / cm is preferred. ２ A specific example of the jelly strength is 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 , 1300 g / cm ２ , 1500 g / cm ２, 1800 g / cm ２ , 2000 g / cm ２ , 2500 g / cm ２ and may be within a range between any two of these values. If capsule disintegration is difficult to achieve during use, for example, the jelly strength may be set to 1300 g / cm ２ You can also do the following:

[0017] The water-soluble polymers used in the present invention are not limited to these. The content of these water-soluble polymers is 5 to 20% by weight, preferably 15% by weight or less, based on the total solids weight of the soft capsule shell. When alginate (particularly sodium alginate), gellan gum, pectin, or carrageenan is used as a hardening aid or viscosity adjuster, alkali metal salts, alkaline earth metal salts, ammonium salts, etc. may be added as appropriate.

[0018] As described above, the shell contains water. The water is a component that moistens the soft capsule, and is, for example, at least one selected from the group consisting of tap water, ion-exchanged water, distilled water, and ultrapure water. The amount of water is 60% by weight or more based on the total weight of the shell.

[0019] The polyol blended into the soft capsule shell 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 1,000 or less, preferably 500 or less. There is no particular lower limit on 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 shell is within the range of 5 to 10 parts by weight, assuming the weight of the shell is 100 parts by weight. When the amount of polyol is within this range, the presence of shell fragments is less noticeable by hand after the soft capsule is disintegrated on the skin, and the contents become more easily absorbed into the skin. Furthermore, the amount of polyol in the shell is preferably 40% by weight or more based on the total solids weight of the soft capsule shell. 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 the amount of polyol are 40% by weight, 45% by weight, 50% by weight, 55% by weight, 60% by weight, 65% by weight, 70% by weight, 75% by weight, 80% by weight, 83% by weight, 85% by weight, 90% by weight, 92% by weight, and 95% by weight, or any range between any two of these values. When the polyol content is 40% by weight or more, the coating can be imparted with flexibility sufficient to facilitate disintegration of the soft capsule during use, and also can prevent residue from remaining when crushed with the fingers. Furthermore, if the coating becomes too soft, the polyol content can be reduced to, for example, 90% by weight or less. In one embodiment of the present invention, the polyol content is preferably at least twice the amount of the water-soluble polymer. The polyol content may be at least three times, five times, seven times, or even nine times the amount of the water-soluble polymer by mass. When the polyol content is at least twice the amount of the water-soluble polymer, the presence of the coating fragments is less noticeable by hand after disintegration of the soft capsule on the skin, and the contents become more easily absorbed into the skin. The upper limit of the polyol content is not particularly limited as long as a coating can be formed, but is, for example, 20 times or less. The polyol content may be at most 17 times, 15 times, 12 times, or 10 times the amount of the water-soluble polymer.

[0021] In addition to the above-described shell composition, the soft capsule shell of the present invention may optionally contain various additives commonly used in this field, such as flavorings, sweeteners, colorants, and preservatives such as parabens. 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, based on the total solids weight of the composition that will form the capsule shell. In addition, the soft capsule shell of the present invention does not necessarily contain water-insoluble particles. Water-insoluble particles are particles composed of substances that are difficult to dissolve in water. Examples of substances that constitute water-insoluble particles include inorganic substances such as zirconia and silica, and organic substances such as melamine and acrylic. If the shell contains water-insoluble particles, the water-insoluble particles may remain on the skin after grinding the shell, potentially causing discomfort such as a powdery texture. Particularly when the soft capsule is a seamless capsule, the water-insoluble particles are likely to clog the shell liquid as it passes through the multiple nozzles described below, potentially making seamless capsule formation difficult.

[0022] The shell of the soft capsule of the present invention desirably 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 shell is less than 10 μm, the shell strength tends to be low, while if it exceeds 1000 μm, the content volume tends to be small and disintegration tends to be poor.

[0023] The size of the soft capsule of the present invention is not particularly limited, but it is desirable that the diameter be 0.3 to 10 mm, preferably 1 to 8 mm. If the diameter of the capsule is less than 0.3 mm, the components that can be blended into the contents tend to be reduced, and if it exceeds 10 mm, it takes a long time to grind it down.

[0024] The soft capsule of the present invention is intended to be used in a state where it is dispersed in a continuous phase mainly composed of water, and therefore is preferably a wet capsule. In such a wet capsule, the shell preferably contains 60 wt% or more of water based on its total weight. The continuous phase refers to the phase outside the soft capsule when the soft capsule is present in the continuous phase, and refers to the main body of the cosmetic preparation (preparation other than the soft capsule).

[0025] Other Layers The soft capsule of the present invention basically consists of two layers, the above-mentioned fill and the shell, but one or more intermediate layers may be provided between the fill and the shell, if necessary or depending on the type of fill. The intermediate layer may exist to prevent the fill from adversely affecting the shell or to inhibit its solubility.

[0026] The intermediate layer is made of fats and oils having a melting point of 45° C. or higher. The fats and oils having a melting point of 45° C. or higher are selected from the fats and oils having a melting point of 40° C. or higher described above. Specific examples of fats and oils having a melting point of 45° C. or higher include the above-mentioned vegetable (fractionated) fats and oils, beeswax, highly hydrogenated oils, margarine, shortening, etc.

[0027] The intermediate layer may contain lecithin or silicon dioxide to adjust the interfacial tension, viscosity, and specific gravity. There are no particular restrictions on the amount of these ingredients, but the amount must not be such that it inhibits the function of the soft capsule of the present invention.

[0028] Method for Producing Soft Capsules The soft capsules of the present invention may be produced by any method, but the method for producing soft capsules will be described below by taking as an example a case where the soft capsules are seamless capsules.

[0029] The soft capsules of the present invention are usually produced by a dropping method using a multiple nozzle, specifically a method of dropping the capsules into a cooling liquid using a two-layer nozzle (double nozzle). Figure 1 is a schematic vertical cross-sectional view showing one embodiment of the nozzle part of an apparatus for producing the soft capsules of the present invention (i.e., seamless capsules).

[0030] In FIG. 1 , the soft capsule manufacturing apparatus employs a dropping method using a double nozzle 100. In the double nozzle 100, the content liquid is discharged from the inner nozzle 120, and the shell liquid is discharged from the outer nozzle 110. Furthermore, if there is an intermediate layer between the shell and the content, another layer nozzle may be added, and soft capsules may be manufactured using a three-layer nozzle including the intermediate nozzle. During discharge, the liquid is simultaneously extruded at a constant speed into a cooling liquid flowing downward at a steady speed to form a composite jet, which is then released into the cooling liquid. By using the surface tension acting between the cooling liquid and the shell liquid, soft capsules 10 can be continuously manufactured. In FIG. 1 , soft capsules 10 are composed of a shell 11 and a content 12.

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

[0032] Immediately after soft capsules are produced in the cooling liquid as described above, the cooling liquid adheres to the outer surface of the soft capsules, and therefore, in the soft capsule manufacturing method, it is preferable to carry out a separation step of separating the soft capsules from the cooling liquid. Also, this manufacturing method does not necessarily have to include a drying step.

[0033] Particle Size Distribution of Soft Capsule Shell Fragments As described above, the soft capsules obtained by the above method require that the particle size distribution of the shell fragments obtained by pulverizing with a bead homogenizer has a particle size of 1000 μm or less at a volume-based cumulative frequency of 90%. This ensures that when soft capsules are incorporated into cosmetics, the presence of the shell fragments is less noticeable when crushed with fingers during use, and the contents become more easily absorbed into the skin. In other words, by providing a soft capsule with a shell having a particle size of 1000 μm or less at a volume-based cumulative frequency of 90% during use, the shell fragments are more easily broken down into small pieces when crushed with fingers. Therefore, the presence of the shell fragments is less noticeable during use, and the contents become more easily absorbed into the skin. The particle size distribution of the shell fragments described above is a physical property of the shell that indicates the ease with which the shell fragments break down into small pieces, and does not necessarily have to match the particle size distribution of the shell fragments obtained by crushing the shell on the skin during use.

[0034] When crushing soft capsules using a bead homogenizer, the soft capsules and beads are placed together in the tube of the homogenizer. The soft capsules are crushed by causing the beads to collide with the soft capsules using vibrations from the bead homogenizer. The crushing conditions for the soft capsules are a vibration frequency of 18.0 Hz and a crushing time of 90 seconds.

[0035] The beads may be any material capable of crushing the soft capsules, and the material and particle size of the beads are not particularly limited. Examples of bead materials include ceramics, glass, and metals such as stainless steel. The particle size of the beads may be larger than that 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 the particle size of the soft capsules. As a specific example, when 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 the present invention, as described above, in the particle size distribution of the film fragments, the particle diameter at which the volume-based cumulative frequency is 90% must be 1000 μm or less. Generally, particle size distribution is represented by a graph with particle diameter (μm) on the horizontal axis and particle amount (frequency) (volume %) on the vertical axis. The particle diameter at which the cumulative volume of the curve reaches 90% of the total is the "particle diameter at which the volume-based cumulative frequency is 90%." For example, Figure 2 shows a graph in which the vertical axis represents the relative particle amount (frequency) in volume % and the horizontal axis represents particle diameter, with these plotted as a normal distribution for illustrative purposes. In Figure 2, the particle diameter can be determined by accumulating the curve from the smallest particle diameters and taking the particle diameter at which the volume % reaches 90%. In the present invention, the particle diameter at which the volume-based cumulative frequency is 90% must be 1000 μm or less (i.e., 1 mm or less). If the particle size at which the cumulative volume frequency is 90% exceeds 1000 μm, the film is difficult to break into small pieces, and even if it is crushed with fingers, a residual feeling will remain for a long time. The particle size at which the cumulative volume frequency is 90% is preferably 960 μm or less. The particle size at which the cumulative volume frequency is 90% may 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 about 100 μm is sufficient. The particle size at which the volume-based cumulative frequency is 90% may be 200 μm or more, 300 μm or more, 400 μm or more, 500 μm or more, 600 μm or more, 700 μm or more, 800 μm or more, 850 μm or more, or 890 μm or more.

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

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

[0039] Example 1 Agar A (jelly strength 610 to 650 g / cm ２ A coating solution was prepared by mixing 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 ion-exchanged water and heating the mixture in an autoclave at 105° C. for 10 minutes to dissolve the mixture.

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

[0041] The obtained seamless capsules were defatted, and then 75 parts by weight of the seamless capsules were immersed 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 part by weight of phenoxyethanol, and 94.9 parts by weight of ion-exchanged water) to prepare a cosmetic product.

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

[0043] Two glass beads (Sansho Glass Beads No. 7) (approximately 0.9 g) and 0.2 g of seamless capsules were placed in a microtube (specifically, a 2 mL microtube (AS ONE GDMST-2ML)) of a bead homogenizer (TissueLyser II manufactured by Qiagen), the tube was closed with a lid, and the tube was set in the bead homogenizer, where the seamless capsules were crushed under conditions of a vibration frequency of 18.0 Hz and a time of 90 seconds. After crushing, the membrane fragments were washed once with 0.5 mL of ethanol and twice with 0.5 mL of hexane to obtain a membrane fragment sample. The above procedure was repeated to obtain 3 g of membrane fragment sample.

[0044] The obtained capsule pieces were subjected to measurement of the volumetric particle size distribution and the average diameter (or particle diameter at 90% cumulative frequency) under wet conditions in ethanol using a laser diffraction / scattering particle size distribution analyzer (SALD-2300 manufactured by Shimadzu Corporation). The volumetric particle size distribution was plotted on a graph with the measured values ​​on the vertical axis representing the relative particle amount (volume %) and the horizontal axis representing the particle diameter (μm), as shown in Figure 3. The obtained capsules were also subjected to the following sensory test.

[0045] <Sensory Evaluation> 0.1 g of capsules were placed on the back of the hand, and the capsules and capsule shell fragments were crushed in a circular motion with the finger pads of the other hand. A sensory evaluation was performed according to the following criteria. -: It took more than 30 seconds for all capsules to break, the size of the remaining capsule shell fragments was larger than the particle size (1.5 mm), and the presence of the capsule shell fragments was felt by hand, so no improvement in the compatibility of the contents with the skin was observed. +: It took 15 to 30 seconds for all capsules to break, the size of the remaining capsule shell fragments was smaller than the particle size (1.5 mm), the presence of the capsule shell fragments was difficult to feel by hand, and an improvement in the compatibility of the contents with the skin was observed. ++: All capsules broke within 15 seconds, the size of the remaining capsule shell fragments was smaller than the particle size (1.5 mm), the presence of the capsule shell fragments was difficult to feel by hand, and an improvement in the compatibility of the contents with the skin was observed.

[0046] The results of the sensory evaluation using the capsules are shown in Table 1. Table 1 also shows the coating formulation, the mass ratio of polyol / water-soluble polymer, the particle size at a volume-based cumulative frequency of 90%, and the coating thickness (μm).

[0047] Examples 2 to 5 and Comparative Examples 1 and 2 Capsule shell solutions were prepared according to the formulations shown in Table 1, and seamless capsules and cosmetics were produced in the same manner as in Example 1. As in Example 1, particle sizes at a cumulative volume frequency of 90% were measured and sensory evaluation was performed, and the results are shown in Table 1. Note that agar B shown in Table 1 has a jelly strength of 900 to 1000 g / cm ２ In Table 1, Na 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 a graph in Figure 3, with the vertical axis representing the relative particle amount (volume %) and the horizontal axis representing the particle size (µm).

[0048] Examples 6 to 8 Capsule shell solutions were prepared according to the formulations shown in Table 2, and seamless capsules and cosmetics were produced in the same manner as in Example 1. As in Example 1, particle sizes at a cumulative volume frequency of 90% were measured and sensory evaluation was performed, and the results are shown in Table 2. As in Table 1, Table 2 also shows the mass ratio of polyol / water-soluble polymer and shell thickness. Note that agar C shown in Table 2 has a jelly strength of 1800 g / cm ２ Similarly to Example 1, the particle size distribution of each Example is shown in a graph in FIG. 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 according to the method of Nikkansui method. Specifically, a 1.5 wt% agar solution was boiled and left to stand at 20°C for 15 hours, and the solidified jelly was measured by measuring the strength of 1 cm ２ This refers to the maximum weight that can be withstood for 20 seconds.

[0050]

[0051] In Examples 1 to 8, the particle diameter of the shell fragments with a volume-based cumulative frequency of 90% in the particle size distribution was 1000 μm or less, and therefore, the sensory evaluations in the sensory test when crushing the capsules were all + or ++, and the capsules broke early, making it difficult to feel the presence of the shell fragments by hand. Regarding the polyol / water-soluble polymer mass ratio, performance was excellent when the polyol was greater than the amount of water-soluble polymer blended. On the other hand, in Comparative Examples 1 and 2, the particle diameter of the shell fragments with a volume-based cumulative frequency of 90% in the particle size distribution exceeded 1000 μm, and therefore, the sensory test results were rated "-," the capsules took more than 30 seconds to disintegrate, the shell fragments (residue) were large, and a good usability was not achieved. The comparative examples are examples in which no polyol was present.

[0052] When the soft capsules of the present invention are used in cosmetics, the time required to crush the capsules during use is shortened, and the presence of membrane fragments is eliminated, providing the user with an excellent feeling when used. The soft capsules of the present invention can be used to add ingredients that have a different function from the cosmetics or that improve the same function, and the capsules can be taken out of the hand and crushed with the fingers at the time of use to release the functional ingredients, thereby improving the functionality of the cosmetics. The soft capsules of the present invention can also be used for coloring, making it possible to adjust the color of the cosmetics using the capsules.

[0053] [Modes of the Invention] [1] A soft capsule for cosmetics comprising a liquid content at room temperature and a shell encapsulating the content, wherein the particle size distribution of shell fragments obtained by pulverizing the soft capsule with a bead homogenizer has a particle size of 1000 μm or less at a volume-based cumulative frequency of 90%. [2] The soft capsule for cosmetics described in [1], wherein the content is an oily liquid. [3] The soft capsule for cosmetics described in [1] or [2], wherein the shell contains a water-soluble polymer and a polyol. [4] The soft capsule for cosmetics described in any of [1] to [3], wherein the amount of the polyol is in the range of 5 to 10 parts by weight, assuming the weight of the shell to be 100 parts by weight. [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 cosmetic soft capsule according to any one of [1] to [5], wherein the moisture content of the shell of the soft capsule is 60% by weight or more. [7] The cosmetic soft capsule according to any one of [1] to [6], wherein the soft capsule is a seamless capsule. [8] The cosmetic soft capsule according to any one of [1] to [7], wherein, in the pulverization using the bead homogenizer, the vibration frequency is 18.0 Hz and the pulverization time is 90 seconds, the beads used to pulverize the soft capsule are glass beads, and the particle size of the glass beads is larger than the particle size of the soft capsule.

[0054] [Explanation of symbols] 10: soft capsule 11: shell 12: contents 100: double nozzle 110: outer nozzle 120: inner nozzle

Claims

1. A soft capsule comprising a liquid content at room temperature and a shell enclosing the content, In the particle size distribution of the shell fragments obtained by pulverizing the soft capsule with a bead homogenizer, the particle size at which the cumulative frequency on a volume basis is 90% is 1000 μm or less, The soft capsule is a seamless capsule, the coating contains a water-soluble polymer, a polyol, and water; The moisture content of the coating is 88.04% by weight or more, the water-soluble polymer comprises agar, and alginic acid or a salt thereof; the polyol is 1,3-butanediol, 1,2-propanediol, or sorbitol; the blending amount of the polyol is within a range of 60% by weight to 95% by weight based on the total solid content of the coating; the amount of the polyol is 2 to 10 times the amount of the water-soluble polymer; the amount of agar blended is within a range of 0.70 to 1.70% by weight relative to the weight of the coating; the amount of alginic acid or a salt thereof is within a range of 0.33 to 0.80% by weight relative to the weight of the coating; In the pulverization using the bead homogenizer, The vibration frequency was 18.0 Hz and the grinding time was 90 seconds. The beads for crushing the soft capsules are glass beads, A soft capsule for cosmetics, characterized in that the particle size of the glass beads is larger than the particle size of the soft capsule.

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

3. 3. The cosmetic soft capsule according to claim 1, wherein the amount of the polyol is in the range of 5 to 10 parts by weight, where the weight of the shell is 100 parts by weight.