Composition containing microbubbles, method for estimating temporal stability of microbubbles, and method for designing composition containing microbubbles

Abstract

To provide a novel composition capable of retaining microbubbles for a long period of time, a method for estimating the stability of microbubbles in the composition, and a method for designing the composition capable of retaining microbubbles for a long period of time.SOLUTION: Provided is a microbubble-containing composition containing microbubbles, a raw material composition before the incorporation of the microbubbles satisfying the following condition. (Condition) The raw material composition has a combination of physical property values (X, Y, Z) that satisfies the following microbubble stability evaluation formula. (Microbubble stability evaluation formula) S≤0.302×X+0.0370×Y+7.56×Z-3.71, where S=0.4 (physical property values), X: pH of the raw material composition measured at a room temperature of 20°C, Y: static surface tension (mN / m) of the raw material composition measured at the room temperature of 20°C, and Z: dynamic surface tension (N / m s) of the raw material composition measured at the room temperature of 20°C.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a composition containing fine bubbles, a method for estimating the temporal stability of fine bubbles, and a method for designing a composition containing fine bubbles. [Background technology]

[0002] A liquid containing fine bubbles is a liquid in which a large number of fine bubbles exist. The fine bubbles contained in the liquid are called microbubbles, nanobubbles, ultrafine bubbles, etc., depending on the size of the bubbles. In general, since a liquid containing fine bubbles has characteristics different from those of water or carbonated water, applications of the liquid containing fine bubbles in various industrial fields are being considered. For this reason, various techniques have been developed to incorporate fine bubbles into water or solutions.

[0003] For example, a spray device with a nanobubble generating mechanism is known for adding nanobubbles to cosmetics (Patent Document 1). Also, a composition for external use of nanobubble cosmetics is known, which is used in a container with a device mechanism for generating nanobubbles (Patent Document 2). It is also known that by adding CO2 hydrate to cosmetics, cosmetics containing a high concentration of ultra-fine bubbles can be produced (Patent Document 3). Also, [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-30171 [Patent Document 2] International Publication No. 2022 / 010000 [Patent Document 3] JP 2020-147520 A Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, microbubble-containing compositions containing microbubbles are known, and research has been conducted on increasing the concentration of microbubbles. However, the concentration of microbubbles in a microbubble-containing composition in a liquid decreases over time due to the influence of the external environment. For this reason, even if a composition has a desired fine bubble concentration immediately after production, the concentration decreases during actual use, and the full effect of the fine bubbles may not be obtained.

[0006] In view of the above situation, An object of the present invention is to provide a technique for improving the stability over time of a composition containing fine bubbles, and to provide a composition containing fine bubbles that has excellent stability over time.

[0007] In order to evaluate the stability of a microbubble-containing composition, it is necessary to actually prepare the microbubble composition and perform a stability test over time in the storage environment of the microbubble-containing composition, etc. Here, the factors that affect the change in concentration of microbubbles have not been clearly elucidated, and evaluation by accelerated testing as in ordinary storage stability tests may not be appropriate in some cases. Therefore, an object of the present invention is to provide a method for estimating the temporal stability of a composition containing fine bubbles. Another object of the present invention is to provide a method for designing a composition containing fine bubbles that has excellent stability over time. [Means for solving the problem]

[0008] As a result of intensive research, the present inventors have found that there is a correlation between the physical property values ​​of a raw material composition, which is the composition before microbubbles are encapsulated in a microbubble-containing composition, and values ​​indicating the stability over time of the microbubble-containing composition obtained by encapsulating microbubbles in the raw material composition.

[0009] Using this correlation, the inventors have found that a microbubble-containing composition in which the physical property values ​​of the raw material composition satisfy specific conditions has excellent stability over time, and have completed the present invention. That is, the present invention for solving the above-mentioned problems relates to a microbubble-containing composition that contains microbubbles, wherein a raw material composition before containing the microbubbles satisfies the following conditions: (conditions) The raw material composition has a combination of physical property values ​​(X, Y, Z) that satisfy the following fine bubble stability evaluation formula: (Fine bubble stability evaluation formula) S≦0.302×X+0.0370×Y+7.56×Z-3.71 where S=0.4 (Physical properties) X: pH of the raw material composition measured at room temperature (20° C.) Y: static surface tension (mN / m) of the raw material composition measured at room temperature of 20°C Z: Dynamic surface tension of the raw material composition measured at room temperature (20°C) (N / m s)

[0010] The microbubble-containing composition of the present invention has excellent stability over time. That is, the present invention can provide a composition capable of retaining fine bubbles for a long period of time.

[0011] In a preferred embodiment of the present invention, the numerical ranges of the physical property values ​​(X, Y, Z) of the raw material composition are as follows: (Numerical range) X: pH measured at room temperature (20°C) is between 4 and 8. Y: Static surface tension measured at room temperature (20℃) is 28mN / m to 68mN / m Z: Dynamic surface tension measured at room temperature (20°C) is 0.05 to 0.5 N / m s

[0012] In a preferred embodiment of the present invention, the raw material composition contains a compound having 1 to 16 hydrophilic groups in its structural formula.

[0013] In a preferred embodiment of the present invention, the raw material composition contains a moisturizer and / or a preservative.

[0014] According to the above-mentioned preferred embodiment, it is possible to provide a fine bubble-containing composition having excellent stability over time.

[0015] In a preferred embodiment of the present invention, the microbubble-containing composition is a cosmetic.

[0016] According to this embodiment, it is possible to provide a cosmetic preparation that is excellent in stability over time and stably maintains the effect of the fine bubbles.

[0017] Furthermore, the present inventors have completed a method for estimating the stability over time of a microbubble-containing composition from the physical properties of the raw material composition, based on the above correlation. That is, the present invention for solving the above-mentioned problems provides a method for estimating the temporal stability of fine bubbles in a microbubble-containing composition that contains fine bubbles, the method comprising the steps of: utilizing a pre-prepared correlation model between the physical property values ​​at 20°C of a raw material composition before the incorporation of the fine bubbles and the temporal stability of the fine bubbles in the microbubble-containing composition, estimating the temporal stability of the fine bubbles in the target microbubble-containing composition from the physical property values ​​of the raw material composition of the target microbubble-containing composition.

[0018] According to the present invention, the stability over time of fine bubbles in a composition can be estimated from the physical property values ​​of the raw material composition without conducting, for example, a stability test over time.

[0019] In a preferred embodiment of the present invention, the physical property values ​​of the raw material composition at 20° C. are a combination of static surface tension, pH, and dynamic surface tension. By using the above physical properties, the temporal stability of the microbubbles can be estimated with high accuracy.

[0020] The present inventors have found that by utilizing the above correlation, it is possible to efficiently design a microbubble-containing composition, and have completed the invention of a method for designing a microbubble-containing composition. That is, the present invention for solving the above problems is: The method for designing a microbubble-containing composition containing fine bubbles comprises a step of determining a formulation for the microbubble-containing composition such that a raw material composition prior to the incorporation of fine bubbles satisfies the following conditions: Condition: The raw material composition has a combination of physical property values ​​(X, Y, Z) that satisfy the following fine bubble stability evaluation formula. (Fine bubble stability evaluation formula) S≦0.302×X+0.0370×Y+7.56×Z-3.71 where S=0.4 (Physical properties) X: pH of the raw material composition measured at room temperature (20° C.) Y: static surface tension (mN / m) of the raw material composition measured at room temperature of 20°C Z: dynamic surface tension (N / m·s) of the raw material composition measured at room temperature of 20°C. According to the present invention, it is possible to design a microbubble-containing composition that has excellent stability over time. Effect of the Invention

[0021] According to the present invention, it is possible to provide a microbubble-containing composition having excellent stability over time. Furthermore, it is possible to estimate the stability of the microbubble-containing composition over time and to design a microbubble-containing composition having excellent stability over time by measuring the physical properties of the raw material composition without actually conducting a stability test over time. [Brief description of the drawings]

[0022] [Figure 1] 1 shows the results of measurement of the UFB number concentration in Example 1 and Formulation Example 1. [Diagram 2] Example 1: The figure shows the measurement results of the remaining rate of number concentration when stored for 2 weeks to 1 month under various temperature conditions, relative to the number of UFBs at the time of production being 1. [Diagram 3] 1 shows the results of comparing the residual rate of Example 1, UFB water stored under temperature cycle conditions for 2 weeks to 1 month, with that of Formulation Example 1. [Figure 4] 1 shows the measurement results of the UFB remaining rate in Example 2 and Formulation Example 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Hereinafter, an embodiment of the present invention will be described in detail. In this specification, a composition containing fine bubbles as a product is referred to as a "microbubble-containing composition", and a composition before the inclusion of fine bubbles and used in the production of a microbubble-containing composition is referred to as a "raw material composition".

[0024] <Microbubble-containing composition> The microbubble-containing compositions of the present invention are characterized by the nature of the raw material compositions used to prepare the microbubble-containing compositions. Specifically, in the microbubble-containing composition of the present invention, the raw material composition has a combination of physical property values ​​(X, Y, Z) that satisfy the following microbubble stability evaluation formula. (Fine bubble stability evaluation formula) S≦0.302×X+0.0370×Y+7.56×Z-3.71 (Physical properties) X: pH of the raw material composition measured at room temperature (20° C.) Y: static surface tension (mN / m) of the raw material composition measured at room temperature of 20°C Z: Dynamic surface tension (N / m s) of the raw material composition measured at room temperature (20°C)

[0025] Here, S is preferably 0.4, more preferably 0.5, more preferably 0.6, more preferably 0.7, more preferably 0.8, more preferably 0.9, and particularly preferably 1.0. As shown in the examples described later, the microbubble stability evaluation formula is a multiple regression model derived by performing multiple regression analysis between the stability index value and various physical property values ​​of the raw material composition, the ratio of the number of microbubbles after storage at 20°C for 2 weeks to the number of microbubbles at the time of production being taken as 1, as a value indicating the stability over time of microbubbles in the microbubble-containing composition (stability index value). In other words, S is an estimated ratio of the number of fine bubbles after storage at 20°C for two weeks to the number of fine bubbles at the time of manufacture, assuming that this is 1. Here, the ratio of the number of microbubbles after storage for two weeks at 20°C to the number of microbubbles at the time of production in pure microbubble-containing water that does not contain other ingredients is (0.398), assuming that the number is 1. Therefore, S can preferably be a value equal to or greater than that of pure microbubble-containing water.

[0026] The physical property values ​​(X, Y, Z) of the raw material composition can be appropriately set in appropriate ranges depending on the application of the microbubble-containing composition, but for example, the following ranges are preferable. These ranges are particularly suitable for use as external preparations for skin, such as cosmetics. X: pH measured at room temperature (20°C) Preferably, the pH is 4 to 8, more preferably, 5 to 7.5, and particularly preferably, 5.5 to 7. Y: static surface tension (mN / m) measured at room temperature of 20°C Preferably 0 to 68 mN / m, more preferably 28 to 64 mN / m Z: Dynamic surface tension measured at room temperature (20°C) (N / m s) Preferably, 0 to 0.5 N / m s, and more preferably, 0.05 to 0.2 N / m s

[0027] The physical property values ​​(X, Y, Z) of the raw material composition are preferably measured by the following method. X: pH at room temperature (20°C) The measurement can be performed using a pH / ion meter HM-42X manufactured by DKK-TOA Corp. In this specification, the measurement was performed after calibrating the pH using a neutral phosphate pH standard solution (pH 6.86 / room temperature 25° C.) as a standard buffer solution. Y: static surface tension at room temperature (20°C) (mN / m) Measurements can be performed using an automatic surface tensiometer CBVP-Z manufactured by Kyowa Interface Science Co., Ltd. In this specification, measurements were performed under the following conditions after calibration so that the surface tension of ultrapure water (electrical conductivity 18.2 MΩ cm) was 72.8 mN / m (literature value). (Conditions) Temperature: Room temperature 20℃, Measurement method: Wilhelmy Plate method, Measurement time: 30 minutes Z: Dynamic surface tension at room temperature (20°C) (N / m s) Measurements can be made using a BP100 bubble pressure dynamic surface tensiometer manufactured by Sanyo Trading Co., Ltd. The dynamic surface tension is determined by the slope of a plot of interfacial life (ms) on the horizontal axis and interfacial tension (mN / m) on the vertical axis. Preferably, the dynamic surface tension can be calculated as the slope of three plots taken from 8 to 10 milliseconds after the interfacial life. Measurements were made under the following conditions. (Conditions) Temperature: Room temperature 20℃, Measurement method: Bubble pressure type, Interface detection sensitivity: 50 Pa, Interface life range to be measured: 5 to 10,000 milliseconds

[0028] Here, for the measurement of the physical properties of the raw material composition, a composition obtained by removing microbubbles from the microbubble-containing composition by freezing, heating, applying ultrasonic waves, etc. can be regarded as the raw material composition and used as the subject of the measurement. The microbubble-containing composition itself can also be regarded as the raw material composition and used as the subject of the measurement. This is because, according to the study by the present inventor, it was verified that there is almost no difference in the physical properties between the raw material composition and the composition obtained by removing microbubbles from the microbubble-containing composition and the microbubble composition.

[0029] The formulation of the raw material composition is appropriately designed depending on the application of the microbubble-containing composition. For example, when the composition is used as a skin external preparation such as a cosmetic, the raw material compounds are selected from those that are acceptable for incorporation into skin external preparations such as cosmetics.

[0030] The raw material composition preferably contains a compound having a total of 1 to 16 hydrophilic groups in its structural formula. Suitable examples of the hydrophilic group in the structural formula include a hydroxyl group, an ether group, an ester group, and a carbonyl group. For example, the composition may contain a compound having a total number of hydrophilic groups, including hydroxyl groups and hydrophilic groups other than hydroxyl groups, of 2 to 16. The composition may also contain a compound having 1 to 6 hydroxyl groups and at least one hydrophilic group other than hydroxyl groups. The composition may also contain a compound having 4 to 16 ether groups. The composition may also contain a compound having 6 ether groups and 2 carbonyl groups. The composition containing the above compounds can retain fine bubbles for a long period of time.

[0031] The concentration of the compound in the raw material composition is, for example, 0.005% by mass or more, preferably 0.01% by mass or more, 0.5% by mass or more, 1% by mass or more, 3% by mass or more, 5% by mass or more, and, for example, 30% by mass or less, 20% by mass or less, 14% by mass or less.

[0032] The raw composition preferably includes a humectant and / or a preservative. The humectant is preferably selected from polyhydric alcohols, glycols, and sugar alcohols. The moisturizing agent is preferably dipropylene glycol (DPG), butylene glycol, glycerin, sorbitol, bisPEG-18 methyl ether dimethylsilane, cyclohexane-1,4-dicarboxylic acid bisethoxydiglycol, PEG / PPG / polybutylene glycol-8 / 5 / 3 glycerin.

[0033] The preservative is preferably selected from polyhydric alcohols and glycol ethers. The preservatives preferably include ethylhexylglycerin, phenoxyethanol, and pentylene glycol. The microbubble-containing composition of the present invention may preferably contain one or more of the above preservatives. Preferably, these preservatives are contained in the composition at concentrations generally used in cosmetics. The composition containing the above preservatives can maintain the microbubbles for a long period of time.

[0034] The concentration of the moisturizer in the raw material composition is, for example, 0.01% by mass or more, 1% by mass or more, 3% by mass or more, 5% by mass or more, 10% by mass or more, or 15% by mass or more. The concentration of the compound in the raw material composition is, for example, 30% by mass or less, 20% by mass or less, or 14% by mass or less. The concentration of the preservative in the raw material composition is, for example, 0.005% by mass or more, preferably 0.01% by mass or more, 0.1% by mass or more, and the concentration of the compound in the raw material composition is, for example, 5% by mass or less, 3% by mass or less. For example, when the microbubble-containing composition is a cosmetic, each compound is within the range permitted for inclusion in the cosmetic.

[0035] The microbubble-containing composition of the present invention may contain one or more components other than water, and preferably may contain a combination of more than one of the above compounds, moisturizers and preservatives. When a combination of a plurality of the above compounds, moisturizers, and preservatives is contained, the raw material composition may contain them so that the physical property values ​​of the entire raw material composition satisfy the above fine bubble stability evaluation formula.

[0036] The microbubble-containing composition of the present invention may simultaneously contain a raw material composition having low microbubble stability and a raw material composition having high microbubble stability according to the above-mentioned microbubble stability evaluation formula. In such a case, the combination and content of the raw material compositions may be appropriately increased or decreased so as to satisfy the microbubble stability evaluation formula. The microbubble-containing composition of the present invention may contain optional components within the range that does not impair the effects of the present invention. For example, it may contain components that are commonly used in cosmetics.

[0037] The microbubble-containing composition of the present invention preferably contains microbubbles having a diameter of 100 μm or less. The diameter of the fine bubbles may be in the range of 1 μm to 100 μm, preferably 1 μm or less, more preferably 10 nm to 800 nm, and particularly preferably 10 to 300 nm. In particular, bubbles of 1 μm or less (ultra-fine bubbles: UFB) have excellent adsorptivity for substances in water and have a high cleaning effect. In the present invention, bubbles of 1 μm or less can be particularly preferably used. The method for measuring the diameter of the fine bubbles is not particularly limited, and a person skilled in the art can use a commonly used method. Examples include particle trajectory analysis (PTA) and laser diffraction / scattering.

[0038] The microbubble-containing composition of the present invention preferably contains microbubbles at least 10 million / mL, more preferably at least 20 million / mL, more preferably at least 50 million / mL, even more preferably at least 70 million / mL, even more preferably at least 100 million / mL, more preferably at least 300 million / mL, and even more preferably at least 400 million / mL. The upper limit of the concentration of microbubbles in the microbubble-containing composition of the present invention is not particularly limited, and examples of the upper limit include 3 billion / mL or less, 2 billion / mL or less, 1 billion / mL or less, and 500 million / mL or less. The microbubble-containing composition of the present invention particularly preferably contains microbubbles having a diameter of 1 μm or less at 10 million bubbles / mL or more, more preferably at least 20 million bubbles / mL or more, more preferably at least 50 million bubbles / mL or more, even more preferably at least 70 million bubbles / mL or more, even more preferably at least 100 million bubbles / mL or more, more preferably at least 300 million bubbles / mL or more, and even more preferably at least 400 million bubbles / mL or more. There is no particular upper limit to the concentration of fine bubbles having a diameter of 1 μm or less in the fine bubble-containing composition, and examples of the upper limit include 3 billion bubbles / mL or less, 2 billion bubbles / mL or less, and 1 billion bubbles / mL or less.

[0039] The number concentration of the microbubbles contained in the microbubble-containing composition of the present invention is measured by the following method. (1) Fine bubbles are generated in a solution, and the solution containing the fine bubbles is filled into a 25 mL glass screw. (2) After storing at room temperature of 20°C for 24 hours, the microbubble number concentration is measured using a commercially available nanoparticle measuring device. (3) As a measurement control (corresponding to background), the number concentration of microbubble particles in the solution before microbubbles are generated is measured in advance and subtracted from the measured value after one day of storage at room temperature of 20° C. The difference is calculated as the number concentration of microbubbles contained in the composition. In the present invention, the number concentration of fine bubbles can be measured by a nanotracking method using a commercially available nanoparticle measuring device. The measuring device preferably has a measurable range of particle concentration of 1 million particles / mL to 1 billion particles / mL. In addition, a device capable of measuring under corresponding conditions can be appropriately selected depending on the particle size of the bubbles to be measured. Here, when measuring the number concentration of ultra-fine bubbles, an example is a nanoparticle analyzer (NS300) manufactured by Malvern Panalytical.

[0040] The gas constituting the fine bubbles in the present invention preferably contains one or more gases selected from the group consisting of air, hydrogen, carbon dioxide, oxygen, nitrogen and ozone. Furthermore, the gas is not limited to a gas composed of a single substance, and a composite gas may also be used.

[0041] The microbubble-containing composition of the present invention is preferably a cosmetic product. The formulation of the microbubble-containing composition of the present invention is preferably in a liquid state. Furthermore, as long as it is liquid, it may be in any formulation that can be commonly produced by those skilled in the art. Examples include, but are not limited to, solutions, suspensions, emulsions, pastes, gels, creams, lotions, soaps, surfactant-containing cleansers, oils, emulsion foundations, and sprays.

[0042] The microbubble-containing composition of the present invention can be produced by incorporating microbubbles into a raw material composition. After production, the microbubble-containing composition of the present invention may be diluted with a dilution solvent or the like to a desired microbubble number concentration. The method for enclosing fine bubbles in the raw material composition is not particularly limited, and may be any known method. Examples of such a method include a method in which a gas injected into a liquid through the micropore surface is sheared by a high-speed liquid flow along the micropore surface to generate and contain gas bubbles, or a method in which a gas-liquid mixture is pressurized with a pump, the gas components are dissolved in the liquid until the liquid becomes supersaturated, undissolved gas bubbles are separated, and only the supersaturated liquid is ejected into a liquid at normal pressure through a pressure reducing valve, causing gas bubbles to precipitate and be contained.

[0043] <Method for estimating stability of microbubbles over time> The method for estimating the temporal stability of microbubbles of the present invention utilizes a previously prepared correlation model between the physical property values ​​of the raw material composition at room temperature 20°C and the temporal stability of microbubbles in the microbubble-containing composition, and estimates the temporal stability of microbubbles in a target microbubble-containing composition from the physical property values ​​of the raw material composition of the target microbubble-containing composition.

[0044] The correlation model is not particularly limited, and may be a linear regression model, a decision tree model, a random forest model, a neural network, a support vector machine (SVM), a principal component analysis (PCA), or the like. The correlation model can be generated as follows. (1) A plurality of samples of microbubble-containing compositions are prepared from a plurality of raw material compositions, and a value indicating the stability of microbubbles over time (stability index value) is obtained for each sample. The stability index value may be the ratio of the number of microbubbles after storage for a predetermined period of time under predetermined conditions to the number of microbubbles at the time of production (number ratio over time), or a value synonymous with this ratio. (2) Obtain various physical property values ​​of the multiple raw material compositions used to prepare the samples. The physical property values ​​include pH, static surface tension (mN / m), dynamic surface tension (N / m s), specific gravity, amount of dissolved oxygen (mg / L), contact angle (°), friction coefficient, etc. In addition, the conditions for obtaining the physical property values ​​can be set arbitrarily to obtain the physical property values. (3) The correlation between the stability index value and the physical property value (one or a combination of a plurality of values) is analyzed, and a correlation model capable of explaining the correlation is selected.

[0045] By utilizing the correlation model generated in this manner, it is possible to estimate the temporal stability of a microbubble-containing composition, the temporal stability of which is unknown, produced from a raw material composition by measuring the physical properties of the raw material composition.

[0046] The correlation model is preferably a multiple regression model, and the correlation model preferably has an objective variable being the ratio of the number of microbubbles when stored for a predetermined period of time under predetermined conditions to the number of microbubbles at the time of production (time-dependent number ratio), or a value equivalent to said ratio, and an explanatory variable being one or more physical property values ​​selected from static surface tension, pH, and dynamic surface tension, more preferably a combination of two or more physical property values, and even more preferably a combination of all physical property values. Here, the static surface tension of the raw material composition has the greatest contribution to the temporal stability of the fine bubbles, and therefore the explanatory variables of the correlation model are preferably a combination of the static surface tension, pH, and / or dynamic surface tension.

[0047] The ratio of the number of microbubbles over time is preferably calculated by dividing the number concentration of microbubbles in the composition after storage for 2 weeks at room temperature of 20° C. by the number concentration of microbubbles in the composition immediately after production.

[0048] The correlation model of the present invention is, for example, the following multiple regression equation. (Fine bubble stability evaluation formula) S=aX+bY+cZ-d Here, S is the ratio of the number of particles over time, the variables X, Y, and Z are the following physical property values ​​of the raw material composition, a, b, and c are regression coefficients, and d is an error term. (Physical properties) X: pH of the raw material composition measured at room temperature (20° C.) Y: static surface tension (mN / m) of the raw material composition measured at room temperature of 20°C Z: Dynamic surface tension (N / m s) of the raw material composition measured at room temperature (20°C)

[0049] The estimation method of the present invention can estimate, for example, that the higher the calculation result of the fine bubble stability evaluation formula, i.e., the higher the temporal stability of the fine bubbles, the higher the value of S. In addition, for example, a reference value for the value of S may be set in advance, and the presence or absence of temporal stability or its level may be estimated (evaluated) based on this reference value.

[0050] The microbubble-containing composition to be estimated by the estimation method of the present invention may contain one or more components other than water. From the obtained estimation results, it is also possible to evaluate the stability of the microbubble-containing composition when microbubbles are enclosed in the raw material composition from which the physical property values ​​were obtained. Furthermore, it is also possible to combine the estimated values ​​obtained from multiple raw material compositions to estimate the effect on stability when multiple components are combined. It is preferable to use a raw material composition containing a plurality of components, which has a composition substantially similar to that of the final product, in order to more accurately evaluate the temporal stability of the fine bubbles in the final product. For other explanations, the description in the section on the microbubble-containing composition above can be used.

[0051] <Method of Designing a Composition Containing Fine Bubbles> The present invention relates to a method for designing a composition containing fine bubbles, which comprises a step of determining a formulation of a composition such that the raw material composition before containing fine bubbles satisfies the following conditions: conditions: The raw material composition has a combination of physical property values ​​(X, Y, Z) that satisfy the following fine bubble stability evaluation formula: (Fine bubble stability evaluation formula) S≦0.302×X+0.0370×Y+7.56×Z-3.71 where S=0.4 (Physical properties) X: pH of the raw material composition measured at room temperature (20° C.) Y: static surface tension (mN / m) of the raw material composition measured at room temperature of 20°C Z: Dynamic surface tension (N / m s) of the raw material composition measured at room temperature (20°C)

[0052] The design method of the present invention can preferably include a step of determining the formulation and blending concentrations of the raw material compositions contained in the composition to be designed such that the physical property values ​​of the entire formulation satisfy the above conditions. When determining the blending ratio of the raw material composition to be included in the composition to be designed, any components or combinations thereof may be selected, and the blending ratio of each component may be appropriately increased or decreased to determine the blending concentration such that the physical properties of the raw material composition satisfy the above-mentioned evaluation formula. For other explanations, the above explanations regarding the microbubble-containing composition and the estimation method can be used.

[0053] In addition, the design method of the present invention may include, in the step of determining the recipe and blending concentration of the raw material composition, a step of substituting the physical property values ​​of the raw material compound aqueous solutions, which are candidates for inclusion in the raw material composition, one by one into the fine bubble stability evaluation formula. After the above process, the aqueous solutions of each candidate raw compound may be evaluated for fine bubble stability. The raw material composition formulation may be determined by appropriately combining the aqueous solutions of raw material compounds evaluated to have high microbubble stability by the above-mentioned process. In such a case, the method may include a process of determining whether the physical property values ​​of the entire raw material composition after the formulation is determined satisfy the microbubble stability evaluation formula.

[0054] In a preferred embodiment of the present invention, the formulation of the composition is not particularly limited as long as the above conditions are satisfied. Preferably, the formulation of the raw material composition is determined so as to include compounds commonly used in cosmetics. Liquid components are preferred. In addition, solid, powder, and other components may be used as long as they are soluble in the composition. EXAMPLES

[0055] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. In the following examples, tests were carried out using fine bubbles of the present invention, that is, bubbles having a diameter of 1 μm or less (ultra-fine bubbles: hereinafter referred to as UFB), which have a particularly high cleaning effect. The diameter of the microbubbles was measured by particle trajectory analysis (PTA). The number concentration of fine bubbles in the composition was measured using a nanoparticle analyzer (Nanosite NS300) manufactured by Malvern Panalytical. In the examples, the blend concentrations are in mass % unless otherwise specified.

[0056] (Example 1, Derivation of UFB temporal stability prediction formula) Preparation of UFB-containing compositions The raw material compound was added to the UFB-containing pure water (number concentration of about 100 million particles / mL) and the pure water, and stirred with a stirrer for about 2 to 3 hours at room temperature until the raw material compound was confirmed to be dissolved. A UFB-containing composition and a raw material composition (blank sample) were obtained, respectively.

[0057] ·test The initial number of UFBs was measured for the UFB-containing composition and the raw material composition (blank sample). After storing each sample at 20°C for 2 weeks (2W), the number of UFBs was measured using NanoSight NS300. Furthermore, the solvent properties (X: pH, Y: static surface tension, Z: dynamic surface tension) of each blank sample at 20° C. were measured. The methods for measuring the above physical properties X, Y, and Z of each blank sample are as follows. X: The pH of each raw material composition at room temperature (20° C.) was measured using a glass electrode pH meter (manufactured by DKK-TOA Corporation). Y: The static surface tension of each raw material composition at room temperature of 20°C was measured using an automatic surface tensiometer CBVP-Z manufactured by Kyowa Interface Science Co., Ltd. After calibration so that the surface tension of ultrapure water (electrical conductivity 18.2 MΩ cm) was 72.8 mN / m (literature value), the measurement was carried out under the following conditions. (Conditions) Temperature: Room temperature 20℃, Measurement method: Wilhelmy Plate method, Measurement time: 30 minutes Z: Using a bubble pressure type dynamic surface tensiometer BP100 manufactured by Sanyo Trading Co., Ltd., the dynamic surface tension of each raw material composition at room temperature of 20° C. was calculated from a plot of interfacial tension (mN / m) and interfacial life (ms). Specifically, a plot was made with time (interfacial life) on the horizontal axis and interfacial tension on the vertical axis, and the slope of the graph was calculated. The slope of three plots was then taken from 8 to 10 milliseconds after the interfacial life, and the dynamic surface tension was calculated. The measurements were also carried out under the following conditions. (Conditions) Temperature: Room temperature 20℃, Measurement method: Bubble pressure type, Interface detection sensitivity: 50 Pa, Interface life range to be measured: 5 to 10,000 milliseconds

[0058] Here, the measured values ​​of the above physical properties of the raw material composition before the incorporation of UFB (blank sample) and the composition after the incorporation of UFB were compared. When the measured values ​​of the physical properties of the raw material composition and the composition were compared, the pH was reduced by 0.18% due to the inclusion of UFB. In addition, the static surface of the composition was reduced by at least about 14% compared to the static surface tension of the raw material composition. Additionally, the dynamic surface tension increased by 3.1%. From the above, it can be said that the change in the physical properties of the raw material composition (blank sample) and the composition after adding UFB, regardless of the presence or absence of UFB, is sufficiently small that the physical properties of the UFB-containing composition can be considered to be the properties of the raw material composition.

[0059] UFB Count Evaluation Method The UFB number concentration measurements were taken for each UFB-containing composition and each blank sample. The measured UFB number concentration of the UFB-containing composition was subtracted from the measured UFB number concentration of a blank sample containing the same type of raw material compound made with pure water. The result was taken as the true value of the UFB number concentration.

[0060] Table 1 shows the UFB number ratio of each UFB-containing composition and the measurement results of the physical properties (pH, static surface tension, dynamic surface tension) of various raw material compositions at room temperature of 20°C. The UFB number ratio was calculated by dividing the measured UFB number concentration of each UFB-containing composition after storage for two weeks at room temperature of 20°C by the measured UFB number concentration of each UFB-containing composition immediately after preparation.

[0061] [Table 1]

[0062] <Multiple regression analysis> A multiple regression analysis was performed using the UFB number ratio in Table 1 as the objective variable and pH at room temperature of 20°C, static surface tension, and dynamic surface tension as explanatory variables. The results of the regression statistics are shown in Table 2, and the coefficients obtained from the multiple regression analysis are shown in Table 3. The significance (F), which indicates the reliability of the combination of explanatory variables used in the multiple regression analysis, was 0.000966. Because the significance (F) was sufficiently small, it can be seen that the multiple regression analysis was able to obtain meaningful explanatory variables.

[0063] [Table 2]

[0064] [Table 3]

[0065] From the results of the multiple regression analysis, a multiple regression equation was determined, and the following microbubble stability prediction equation (Equation 1) was obtained. S=0.302×X+0.0370×Y+7.56×Z-3.71 (Formula 1) Here, S is the ratio of the number of fine bubbles after storage at 20°C for two weeks to the number of fine bubbles at the time of production, where 1 is taken as the number of fine bubbles (ratio of number over time), The variables X, Y, and Z are the following physical property values ​​of the raw material composition. (Physical properties) X: pH of the raw material composition measured at room temperature (20° C.) Y: static surface tension (mN / m) of the raw material composition measured at room temperature of 20°C Z: Dynamic surface tension (N / m s) of the raw material composition measured at room temperature (20°C)

[0066] <Evaluation of the microbubble stability prediction formula> Using the above formula (1), Formulation Example 1 was prepared using a raw material composition determined to have high microbubble stability (S ≥ 0.4). Formulation Example 1 is shown in Table 4 below. In addition, Table 5 shows the physical property values of the entire Formulation Example 1 before containing UFB and the value of S when the physical property values are substituted into formula (1).

[0067] [Table 4]

[0068] [Table 5]

[0069] <UFB Residual Rate Test> The residual rate of UFB in Formulation Example 1 was measured. First, the UFB number concentration in Formulation Example 1 was measured at three points: immediately after the production of Formulation Example 1 (0D), two weeks after the production (2W), and one month after the production (1M). Next, the UFB number concentration after two weeks (2W) and after one month (1M) was divided by the UFB number concentration immediately after the production of Formulation Example 1 (0D). Thereby, the residual rate of the UFB number after two weeks (2W) and after one month (1M) was calculated. In addition, the storage of Formulation Example 1 was carried out at 5°C, 20°C, 40°C, 50°C, and under temperature cycle conditions. Under the temperature cycle conditions, the low temperature and the high temperature were continuously changed.

[0070] The measurement results of the UFB number concentration of Formulation Example 1 stored for a certain period under each temperature condition are shown in Table 6 and Figure 1. Furthermore, the measurement results of the residual rate of the UFB number concentration when stored for two weeks under each temperature condition and the residual rate of the number concentration when stored for one month under each temperature condition, with the UFB number at the time of production being 1, are shown in Table 7 and Figure 2.

[0071] Furthermore, Table 8 shows the comparison results of the residual rates between the UFB water stored for one month under each temperature condition and Formulation Example 1. Among these, the comparison results of the residual rates with the UFB water stored under temperature cycle conditions are shown in Figure 3. The formulation prepared by selecting the raw material composition using the above formula 1 had a high UFB residual rate in the formulation after 2 weeks to 1 month. Furthermore, the UFB residual rate was significantly improved compared to UFB-containing water stored for 1 month.

[0072] [Table 6]

[0073] [Table 7]

[0074] [Table 8]

[0075] As a result, it was demonstrated that the temporal stability of the microbubble-containing composition can be estimated from the stability prediction formula obtained by the multiple regression analysis in Example 1, and that, based on the estimation results, it is possible to design a formulation for a microbubble-containing composition having high temporal stability.

[0076] Example 2: Evaluation of formulations using a stability evaluation formula Formulation Example 2, the fine bubble stability of which is unknown, was prepared, and the UFB remaining test was carried out in the same manner as in Example 1.

[0077] First, a raw material composition typically contained in cosmetics was used to determine Formulation Example 2. The composition of Formulation Example 2 is shown in Table 9.

[0078] [Table 9]

[0079] Next, the physical properties (pH, static surface tension, dynamic surface tension) of each raw material composition were measured at room temperature of 20° C. The method for measuring each physical property was the same as in Example 1. The physical property values of each raw material composition included in Formulation Example 2 at room temperature of 20°C were substituted into (Equation 1) to determine the microbubble stability S. The physical property values of each raw material composition and the calculation results of S are shown in Table 10. The microbubble stability S of the raw material compositions included in Formulation Example 2 was all S = 0.4 or more, and it was estimated that the microbubble stability was high. In addition, the physical property values of the entire Formulation Example 2 before containing UFB and the value of S when the physical property values were substituted into Equation 1 are shown in Table 11.

[0080]

Table 10

[0081]

Table 11

[0082] <UFB Residual Rate Test> Similar to Example 1, the residual rate of UFB in Formulation Example 2 was measured. First, under the same conditions as in Example 1, the UFB number concentration in Formulation Example 2 at two points, immediately after production (0D) and 2 weeks after production (2W), was measured. The results are shown in Table 12. Next, the UFB number concentration after 2 weeks (2W) was divided by the UFB number concentration immediately after production (0D) of Formulation Example 1. Thereby, with the UFB number concentration immediately after production (0D) set to 1, the residual rate of the UFB number after 2 weeks (2W) was calculated. The results are shown in Table 13. Furthermore, the measurement results of the UFB residual rate (%) of Formulation Example 2 are shown in Figure 4.

[0083]

Table 12

[0084]

Table 13

[0085] From the above, it was demonstrated that the stability over time of microbubbles in a microbubble-containing composition can be predicted from the physical property values ​​of the raw material composition using the stability prediction equation obtained by the multiple regression analysis in Example 1. [Industrial Applicability]

[0086] According to the present invention, it is possible to provide a fine bubble-containing composition, such as a cosmetic, in which the fine bubbles have excellent stability over time.

Claims

1. A microbubble-containing composition comprising microbubbles, A microbubble-containing composition, wherein the raw material composition before containing the microbubbles satisfies the following conditions: (conditions) The raw material composition has a combination of physical property values ​​(X, Y, Z) that satisfy the following fine bubble stability evaluation formula: (Fine bubble stability evaluation formula) S≦0.302×X+0.0370×Y+7.56×Z−3.71 Here, S=0.4 (Physical properties) X: pH of the raw material composition measured at room temperature of 20° C. Y: static surface tension (mN / m) of the raw material composition measured at room temperature of 20° C. Z: dynamic surface tension (N / m s) of the raw material composition measured at room temperature of 20°C

2. 2. The microbubble-containing composition according to claim 1, wherein the ranges of the physical property values ​​(X, Y, Z) of the raw material composition are as follows: (Numerical range) X: pH measured at room temperature of 20° C. is 4 or more and 8 or less Y: Static surface tension (mN / m) measured at room temperature of 20°C is 28 to 68 mN / m Z: Dynamic surface tension (N / m·s) measured at room temperature of 20°C is 0.05 or more and 0.5 or less

3. 3. The microbubble-containing composition according to claim 1, wherein the raw material composition contains a compound having 1 to 16 hydrophilic groups in its structural formula.

4. 3. The microbubble-containing composition according to claim 1, wherein the raw material composition further comprises a moisturizer and / or a preservative.

5. 3. The fine bubble-containing composition according to claim 1, which is a cosmetic product.

6. A method for estimating temporal stability of microbubbles in a microbubble-containing composition, comprising the steps of: Using a correlation model previously prepared between the physical property values ​​of the raw material composition at room temperature (20° C.) before the incorporation of the microbubbles and the temporal stability of the microbubbles in the microbubble-containing composition, The method comprises estimating the temporal stability of microbubbles in a target microbubble-containing composition from the physical property values ​​of a raw material composition of the target composition.

7. 7. The method for estimating the temporal stability of fine bubbles according to claim 6, wherein the physical property values ​​of the raw material composition at room temperature of 20°C are a combination of pH, static surface tension, and dynamic surface tension.

8. A method for designing a microbubble-containing composition containing microbubbles, comprising the steps of: The raw material composition before containing the fine bubbles is A method for designing a composition containing fine bubbles, comprising the step of determining a formulation for the composition containing fine bubbles so as to satisfy the following conditions: conditions: The raw material composition has a combination of physical property values ​​(X, Y, Z) that satisfy the following fine bubble stability evaluation formula: (Fine bubble stability evaluation formula) S≦0.302×X+0.0370×Y+7.56×Z−3.71 where S=0.4 (Physical properties) X: pH of the raw material composition measured at room temperature of 20° C. Y: static surface tension (mN / m) of the raw material composition measured at room temperature of 20° C. Z: dynamic surface tension (N / m s) of the raw material composition measured at room temperature of 20°C

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