Inorganic powder dispersion and ultraviolet blocking composition containing the same

Abstract

This disclosure relates to an inorganic powder dispersion. [Solution] The inorganic powder dispersion of the present invention contains a compound containing an adjacent diol, a natural polymer, and an inorganic powder, thereby exhibiting excellent water dispersibility without the need for surfactants, and is applicable to various formulations. It is easy to apply to the skin, minimizes the white cast phenomenon when applied to the skin, and can be easily washed off with water after use.

Description

Technical Field

[0001] The present disclosure relates to an inorganic powder dispersion liquid and an ultraviolet blocking composition containing the same.

Background Art

[0002] Inorganic ultraviolet blockers used in ultraviolet blocking cosmetics may exhibit phototoxicity due to dissociation. Therefore, in order to reduce phototoxicity, inorganic ultraviolet blockers are usually surface-modified with hydrophobic organic molecules (e.g., alkylsilane, stearic acid, etc.).

[0003] However, an inorganic ultraviolet blocker coated with a hydrophobic organic molecule may cause a whitening phenomenon when applied to the skin. In addition, since an ultraviolet blocker coated with a hydrophobic organic molecule has low dispersibility in water, there are limitations in applying it to various formulations. Therefore, it is usually manufactured as a W / O type formulation, but it is difficult to remove after being applied to the skin, and the washability is not good. To solve these limitations, conventionally, a surfactant has been used to disperse an inorganic ultraviolet blocker in water.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In one aspect of the present disclosure, an object is to provide an inorganic powder dispersion liquid.

[0006] In one aspect of the present disclosure, an object is to provide an ultraviolet blocking composition containing the inorganic powder dispersion liquid.

Means for Solving the Problems

[0007] An inorganic powder dispersion according to one aspect of this disclosure comprises a compound containing an adjacent diol, a natural polymer, and an inorganic powder.

[0008] An ultraviolet blocking composition according to one aspect of the present disclosure includes the inorganic powder dispersion. [Effects of the Invention]

[0009] An inorganic powder dispersion and / or a UV-blocking composition containing the same according to one aspect of this disclosure exhibits excellent dispersibility in the aqueous phase and can therefore be realized in various formulations.

[0010] Furthermore, the inorganic powder dispersion and / or ultraviolet blocking composition containing the same according to one aspect of this disclosure is easy to apply to the skin, minimizes the white cast phenomenon when applied to the skin, and can be easily washed off with water after use. This is due to the excellent water dispersibility of the inorganic powder dispersion and / or ultraviolet blocking composition containing the same according to one aspect of this disclosure.

[0011] Furthermore, an inorganic powder dispersion and / or a UV-blocking composition containing the same according to one aspect of this disclosure can exhibit excellent water dispersibility even without a surfactant. [Brief explanation of the drawing]

[0012] [Figure 1] This figure shows the results of comparing the dispersibility of inorganic powder (ZnO) in various polyols. [Figure 2] This figure shows the results of comparing the water dispersibility of inorganic powder dispersions in Comparative Example 1 (hydrophobic ZnO; left), Example 2 (hydrophobic ZnO + 2,3BG + CNF; center), and Example 6 (hydrophobic ZnO + 2,3BG + HA; right). [Figure 3]This figure shows the results of confirming whether or not water-soluble red dye was adsorbed into the inorganic powder dispersions of Comparative Example 1 (hydrophobic ZnO; left), Example 2 (hydrophobic ZnO + 2,3BG + CNF; center), and Example 6 (hydrophobic ZnO + 2,3BG + HA; right). In the upper and lower petri dishes of Figure 3, the water-soluble red dye is shown as a dark black area, while in the lower petri dishes of Examples 2 and 6 of Figure 3, the state in which the water-soluble red dye is adsorbed into the inorganic powder dispersion is shown as a light gray area. [Figure 4] This figure shows the results of comparing the cleaning power of a cosmetic composition containing Comparative Example 1 (hydrophobic ZnO) (Comparative Example 6) and a cosmetic composition containing Example 2 (hydrophobic ZnO + 2,3BG + CNF) (Example 9). [Figure 5] This diagram shows the results of confirming the water dispersibility of the inorganic powder dispersions of Comparative Example 7 (hydrophobic ZnO + water + CNF; left) and Comparative Example 8 (hydrophobic ZnO + water + HA; right). [Modes for carrying out the invention]

[0013] The various examples and terminology used herein should be understood not to limit the technical features described herein to any particular example, but rather to include various modifications, equivalents, or substitutions of such examples.

[0014] The inventors evaluated the wettability properties of hydrophobic inorganic powders by confirming their dispersibility with polyols of various structures (polyols with different hydroxyl group (-OH) positions), and confirmed that the wettability properties of hydrophobic inorganic powders are specifically improved only by compounds containing adjacent diols. Subsequently, by mixing hydrophobic inorganic powders with compounds containing adjacent diols and hydrophilic natural polymers, they developed an ultraviolet blocking agent (inorganic powder dispersion) that exhibits excellent water dispersibility without surfactants, is applicable to various formulations (e.g., O / W type formulations, water-dispersible formulations, etc.), and can be easily washed away with water.

[0015] Definition of Terms In this disclosure, the term "inorganic powder dispersion" means a substance in which inorganic powder is dispersed, and its form is not limited. For example, an inorganic powder dispersion may be a dispersion in which inorganic powder is dispersed and / or wetted in a polyol (e.g., a compound containing adjacent diols). For example, an inorganic powder dispersion may be a dispersion in which inorganic powder is dispersed in a polyol (e.g., a compound containing adjacent diols) and a natural polymer. For example, an inorganic powder dispersion may be in which inorganic powder is dispersed and / or wetted in a polyol (e.g., a compound containing adjacent diols) and coated with a natural polymer. The dispersion may be a liquid or a solid, but is not limited to these.

[0016] In this disclosure, the term "wetting inorganic powder" means an inorganic powder that is wet with a liquid, or an inorganic powder that is sufficiently dispersed in any substance (e.g., a polyol), and its form is not limited. For example, an inorganic powder wet with any first component (A) may be a mixture of inorganic powder and wet with any first component (A). For example, an inorganic powder wet with any first component (A) may be a dispersion of inorganic powder and wet with any first component (A). In this disclosure, a wet inorganic powder may be a mixture of inorganic powder and wet with a compound containing an adjacent diol. In this disclosure, a wet inorganic powder may be a dispersion of inorganic powder in a compound containing an adjacent diol.

[0017] In this disclosure, the term "compound containing a vicinal diol" means a compound in which hydroxyl groups (-OH) are bonded to two adjacent atoms (e.g., carbon atoms). The two hydroxyl groups in a compound containing a vicinal diol occupy adjacent (vicinal) positions. That is, the two hydroxyl groups are bonded to adjacent atoms (e.g., carbon atoms).

[0018] For example, a compound containing adjacent diols may further contain an additional hydroxyl group in addition to the two hydroxyl groups bonded to adjacent atoms (e.g., carbon atoms). In that case, the compound containing adjacent diols may be a polyol. For example, a compound containing adjacent diols may not further contain an additional hydroxyl group in addition to the two hydroxyl groups bonded to adjacent atoms (e.g., carbon atoms). In that case, the compound containing adjacent diols may be a diol.

[0019] The term "silane" in the present disclosure means a compound containing substituted or unsubstituted SiH4. The term "alkylsilane" means a silane substituted with at least one alkyl group. The alkylsilane may be substituted with additional substituents other than the alkyl group (e.g., an alkoxy group).

[0020] Inorganic powder dispersion In one aspect of the present disclosure, an inorganic powder dispersion is provided.

[0021] In one implementation example, the inorganic powder dispersion may include a compound containing adjacent diols, a natural polymer, and an inorganic powder.

[0022] In one implementation example, the inorganic powder may be dispersed in the compound containing adjacent diols and the natural polymer. In one implementation example, the inorganic powder may be dispersed and wetted in the compound containing adjacent diols. In one implementation example, the natural polymer may coat the inorganic powder. In one implementation example, the natural polymer may coat the wetted inorganic powder. In one implementation example, in the inorganic powder dispersion, the inorganic powder is dispersed and wetted in the compound containing adjacent diols, and the wetted inorganic powder may be coated with the natural polymer.

[0023] In one implementation example, the inorganic powder dispersion includes an inorganic powder dispersed and wetted in a compound containing adjacent diols and a natural polymer.

[0024] In one implementation example, the wet inorganic powder may be coated with the natural polymer.

[0025] One aspect of the present disclosure provides an inorganic powder dispersion comprising inorganic powder dispersed and wet in a compound containing an adjacent diol, and a natural polymer, wherein the wet inorganic powder is coated with the natural polymer.

[0026] An inorganic powder dispersion according to one aspect of this disclosure exhibits excellent water dispersibility and can be realized in various formulations, including oil-in-water (O / W) formulations. Furthermore, due to its excellent water dispersibility, the inorganic powder dispersion is easy to apply to the skin and can be easily washed off with water during the subsequent cleaning process.

[0027] In one example, the compound containing the adjacent diol may be at least one selected from the group consisting of 1,2-butylene glycol, 2,3-butylene glycol, 1,2-pentane diol, and 1,2-hexane diol, but is not limited to these.

[0028] When inorganic powder is dispersed in a compound containing adjacent diols (e.g., 1,2-butylene glycol, 2,3-butylene glycol, etc.) or dispersed and wetted with a compound containing adjacent diols, the surface of the wet inorganic powder can be efficiently coated with natural polymers. On the other hand, when inorganic powder is dispersed in a compound that does not contain adjacent diols (e.g., a polyol containing two non-adjacent hydroxyl groups, 1,3-butylene glycol) or dispersed and wetted with the aforementioned other compounds, the surface of the wet inorganic powder cannot be efficiently coated with natural polymers, and as a result, the water dispersibility of the final inorganic powder dispersion may decrease.

[0029] In one implementation example, the inorganic powder may be at least one selected from the group consisting of zinc oxide (ZnO), titanium dioxide, and iron oxide, but is not limited to these. In one implementation example, the inorganic powder may be a substance that has excellent ultraviolet blocking effect and whose safety has been proven.

[0030] In one implementation example, the inorganic powder is a hydrophobic inorganic powder. The hydrophobic inorganic powder can be wetted with a compound containing an adjacent diol and coated with a natural polymer to achieve excellent water dispersibility.

[0031] In one implementation example, the inorganic powder may be surface-modified with at least one hydrophobic compound selected from the group consisting of silicone compounds and saturated fatty acids of C8 to C28.

[0032] In one implementation example, the silicone compound may be, but is not limited to, alkylsilane, octyltriethoxysilane, or triethoxycaprylylsilane. In one implementation example, the silicone compound may be octyltriethoxysilane or triethoxycaprylylsilane.

[0033] In one implementation example, the saturated fatty acids C8-C28 may be stearic acid, but are not limited to it.

[0034] In one implementation example, the natural polymer is a hydrophilic natural polymer.

[0035] In one implementation example, the natural polymer may be at least one selected from the group consisting of cellulose, cellulose nanofiber (CNF), and hyaluronic acid, but is not limited to these.

[0036] In one implementation example, the coating can be realized by bonding a natural polymer to a compound containing an adjacent diol, which is a component of the wetted inorganic powder. In another implementation example, the coating can be realized by bonding any functional group (e.g., a carboxyl group, a hydroxyl group, etc.) contained in the natural polymer to a compound containing an adjacent diol that disperses and / or wets the inorganic powder. The bond may be, but is not limited to, a covalent bond, an ionic bond, or a hydrogen bond.

[0037] In one embodiment, in the inorganic powder dispersion, the wet inorganic powder may have its surface coated with the natural polymer.

[0038] In one example, the inorganic powder dispersion may contain, but is not limited to, 10 to 50% by weight of the compound containing the adjacent diol relative to the total weight. For example, the inorganic powder dispersion may contain, relative to the total weight, 10% or more, 15% or more, 20% or more, 25% or more, 26% or more, 27% or more, 28% or more, 29% or more, 29.5% or more, 30% or more, 31% or more, 32% or more, 33% or more, 34% or more, 35% or more, 40% or more, 45% or more, 50% or more, 10% or less, 15% or less It may include, but is not limited to, amounts of 20% by weight or less, 25% by weight or less, 26% by weight or less, 27% by weight or less, 28% by weight or less, 29% by weight or less, 29.5% by weight or less, 30% by weight or less, 31% by weight or less, 32% by weight or less, 33% by weight or less, 34% by weight or less, 35% by weight or less, 40% by weight or less, 45% by weight or less, and 50% by weight or less, or a combination of these (for example, 29-30% by weight or 20-40%).

[0039] In one example, the inorganic powder dispersion may contain 0.01 to 10% by weight of natural polymer relative to the total weight, but is not limited to these amounts. For example, the inorganic powder dispersion may contain the natural polymer in amounts of 0.01% or more, 0.05% or more, 0.1% or more, 0.2% or more, 0.3% or more, 0.4% or more, 0.45% or more, 0.5% or more, 0.55% or more, 0.6% or more, 0.7% or more, 0.8% or more, 0.9% or more, 1% or more, 2% or more, 3% or more, 4% or more, 5% or more, 6% or more, 7% or more, 8% or more, 9% or more, 10% or more, relative to the total weight, and 0.01% or less, 0.05% or less. It may include, but is not limited to, amounts of 0.1% by weight or less, 0.2% by weight or less, 0.3% by weight or less, 0.4% by weight or less, 0.45% by weight or less, 0.5% by weight or less, 0.55% by weight or less, 0.6% by weight or less, 0.7% by weight or less, 0.8% by weight or less, 0.9% by weight or less, 1% by weight or less, 2% by weight or less, 3% by weight or less, 4% by weight or less, 5% by weight or less, 6% by weight or less, 7% by weight or less, 8% by weight or less, 9% by weight or less, and 10% by weight or less, or a combination of these (for example, 0.4 to 0.6% by weight, or 0.1 to 1% by weight).

[0040] In one example of an inorganic powder dispersion, the weight ratio of the inorganic powder to the compound containing the adjacent diol may be 1:0.1 to 1, but is not limited to these values. For example, in an inorganic powder dispersion, the weight ratio of the inorganic powder to the compound containing the adjacent diol may be 1:0.1 to 1, 1:0.1 to 0.9, 1:0.1 to 0.8, 1:0.2 to 0.7, 1:0.3 to 0.6, 1:0.4 to 0.5, or 1:0.41 to 0.43, but is not limited to these values.

[0041] In one example of an inorganic powder dispersion, the weight ratio of inorganic powder to natural polymer may be 1:0.0001 to 0.1, but is not limited to these values. For example, in an inorganic powder dispersion, the weight ratio of inorganic powder to natural polymer may be 1:0.0001 to 0.1, 1:0.0005 to 0.05, 1:0.001 to 0.01, 1:0.005 to 0.009, or 1:0.006 to 0.008, but is not limited to these values.

[0042] In one example of an inorganic powder dispersion, the weight ratio of the compound containing the adjacent diol to the natural polymer may be 1:0.001 to 1, but is not limited to these values. For example, in an inorganic powder dispersion, the weight ratio of the compound containing the adjacent diol to the natural polymer may be 1:0.001 to 1, 1:0.001 to 0.5, 1:0.005 to 0.1, 1:0.01 to 0.05, or 1:0.015 to 0.017, but is not limited to these values.

[0043] According to one example, wetting a hydrophobic inorganic powder with a compound containing an adjacent diol can improve the coating efficiency of the hydrophilic polymer on the surface of the hydrophobic inorganic powder. As a result, the final product obtained by coating the surface of the wet hydrophobic inorganic powder with a hydrophilic polymer exhibits excellent water dispersibility, can be realized with various formulations, and can be easily washed away with water if necessary.

[0044] According to one example, hydrophobic inorganic powders can be effectively dispersed in compounds containing adjacent diols and hydrophilic natural polymers. The resulting inorganic powder dispersion exhibits excellent water dispersibility, can be implemented in various formulations, and can be easily washed away with water as needed.

[0045] UV blocking composition One aspect of this disclosure provides an ultraviolet blocking composition comprising the aforementioned inorganic powder dispersion.

[0046] The inorganic powder dispersion is the same as described above, so a detailed explanation will be omitted.

[0047] In one example, the ultraviolet-blocking composition may be a cosmetic composition, a food composition, an oral composition, a non-therapeutic composition, a non-therapeutic oral composition, a pharmaceutical composition, or a topical composition. Specifically, the ultraviolet-blocking composition may be a topical composition or a cosmetic composition, but is not limited to these.

[0048] In one implementation example, the ultraviolet blocking composition may be, but is not limited to, an oil-in-water (O / W) emulsion formulation or a water-dispersible formulation.

[0049] In one example, the ultraviolet blocking composition does not have to contain a surfactant, but is not limited to that.

[0050] An inorganic powder dispersion according to one aspect of this disclosure exhibits excellent water dispersibility by coating hydrophobic inorganic powder with a natural polymer that is not a surfactant, and can be well dispersed in an ultraviolet-blocking composition without the use of a surfactant. On the other hand, conventionally, surfactants were used in combination with hydrophobic inorganic powder to disperse it in water.

[0051] In one example, the ultraviolet-blocking composition may contain the inorganic powder dispersion in an amount of 1 to 50% by weight relative to the total weight, but is not limited thereto. For example, the ultraviolet-blocking composition may contain the inorganic powder dispersion in an amount of 1% or more by weight, 5% or more by weight, 10% or more by weight, 15% or more by weight, 20% or more by weight, 25% or more by weight, 30% or more by weight, 34% or more by weight, 35% or more by weight, 40% or more by weight, 45% or more by weight, or 50% or more by weight relative to the total weight, or 1% or less by weight, 5% or less by weight, 10% or less by weight, 15% or less by weight, 20% or less by weight, 25% or less by weight, 30% or less by weight, 34% or less by weight, 35% or less by weight, 40% or less by weight, 45% or less by weight, or 50% or less by weight, or a combination of these (for example, 30-40% by weight, 25-45% by weight), but is not limited thereto.

[0052] In one implementation example, the ultraviolet blocking composition may be applied to an object requiring ultraviolet blocking once or multiple times, but is not limited to these cases.

[0053] In one example, the ultraviolet blocking composition may be combined with any other component capable of exhibiting an ultraviolet blocking effect and used in combination with an object requiring ultraviolet blocking, but is not limited to these examples.

[0054] In one example, the ultraviolet blocking composition may further contain, but is not limited to, any other components that can exhibit an ultraviolet blocking effect.

[0055] In one embodiment, the UV-blocking composition may further contain ingredients that may be included in cosmetics. For example, the UV-blocking composition may further contain additives such as preservatives, thickeners, viscosity modifiers, stabilizers, pearlescent agents, metal ion chelating agents, cationic surfactants, pH adjusters, fragrances, and dyes, which are readily available commercially.

[0056] In one embodiment, the UV-blocking composition may be provided in the form of a lotion, emulsion, cream, serum, beauty serum, eye cream, body lotion, body cream, powder, ointment, spray, or stick concealer, but is not limited to these forms.

[0057] UV protection methods One aspect of this disclosure provides a method for blocking ultraviolet light, comprising the step of treating a target object with an inorganic powder dispersion.

[0058] One aspect of this disclosure provides a method for blocking ultraviolet light, comprising the step of treating a target object with a composition containing an inorganic powder dispersion.

[0059] One aspect of this disclosure provides a method for protecting the skin of a target from ultraviolet light, comprising the steps of treating the target with an inorganic powder dispersion.

[0060] One aspect of the present disclosure provides a method for protecting the skin of a target from ultraviolet light, comprising the steps of treating the target with a composition comprising an inorganic powder dispersion.

[0061] The inorganic powder dispersion is the same as described above, so a detailed explanation will be omitted.

[0062] In one implementation example, the target object may be an animal, including mammals (for example, humans), but is not limited thereto.

[0063] In one embodiment, the target object may be an object that requires ultraviolet light blocking. In one embodiment, the target object may be an object that requires an inorganic powder dispersion or a composition containing the same.

[0064] In this disclosure, the treatment may include administration or application to the skin. For example, administration may be by oral administration, transdermal administration, subcutaneous administration, intravenous administration, intraperitoneal administration, intramuscular administration, topical application, or local application.

[0065] In one implementation example, the daily processing rate of the inorganic powder dispersion or the composition containing the inorganic powder dispersion may be 0.0001 to 10000 mg / kg, but is not limited to this range. The processing rate of the inorganic powder dispersion or the composition containing the inorganic powder dispersion should be understood to be determined by considering various relevant factors such as the route of administration, the age, sex, and weight of the subject, and therefore, the processing rate is not intended to limit the scope of the present invention in any way.

[0066] In one implementation example, the inorganic powder dispersion or the composition containing the inorganic powder dispersion may be applied to the target object once a day or in several separate applications per day, but is not limited to these.

[0067] In one implementation example, the inorganic powder dispersion or the composition containing the inorganic powder dispersion may be combined with any other component capable of exhibiting skin-improving and / or ultraviolet-blocking effects. The specific types of any other component are not limited.

[0068] Applications of inorganic powder dispersions One aspect of this disclosure provides applications for the inorganic powder dispersion.

[0069] One aspect of this disclosure provides an application for the inorganic powder dispersion for manufacturing an ultraviolet blocking composition.

[0070] One aspect of this disclosure provides an application for the inorganic powder dispersion for use in blocking ultraviolet light.

[0071] The inorganic powder dispersion is the same as described above, so a detailed explanation will be omitted.

[0072] The present invention will be described in detail below with reference to examples. The following examples are provided to aid in understanding the present invention and do not limit the scope and nature of the invention.

[0073] [Experimental Example 1] Evaluation of the wettability of hydrophobic inorganic powders. Hydrophobic ZnO powder coated with alkylsilane was mixed with six different polyols, and dispersion tests were conducted.

[0074] For the alkylsilane-coated hydrophobic ZnO powder, we used ZnO coated with octyltriethoxysilane (OTS) (product name: MZX-508 OTS; manufacturer: Tayca). Specifically, 2 g of alkylsilane-coated hydrophobic ZnO powder (MZX-508OTS) was added to each of the six polyols listed in Table 1 below (18 g each), and mixed at 300 rpm for 3 minutes using an agitator.

[0075] [Table 1]

[0076] As shown in Table 1 and Figure 1, hydrophobic ZnO powder was not dispersed in polyols without adjacent diols, such as 1,3PG and 1,3BG. In contrast, hydrophobic ZnO powder was effectively dispersed in polyols with adjacent diols.

[0077] [Experimental Example 2] Preparation of inorganic powder dispersions (examples and comparative examples) and evaluation of their water dispersibility. Inorganic powder dispersions were prepared by wetting hydrophobic ZnO powder coated with alkylsilane onto six different polyols and then coating each with a hydrophilic natural polymer. The water dispersibility of the prepared inorganic powder dispersions was then evaluated. The specific method is as follows.

[0078] 1. Preparation of inorganic powder dispersions (Examples and Comparative Examples) Alkylsilane-coated ZnO (product name: MZX-508 OTS; manufacturer: Tayca) was wetted with six different polyols (1,3PG, 1,3BG, 1,2BG, 2,3BG, 1,2PD, 1,2HD), and then coated with hydrophilic natural polymers (cellulose nanofiber (hereinafter, CNF) or hyaluronic acid (hereinafter, HA)) to obtain inorganic powder dispersions (Examples 1-8 and Comparative Examples 2-5). Specifically, to perform polyol wetting and natural polymer coating, the natural polymer was first dispersed in the polyol, and then the hydrophobic ZnO (alkylsilane-coated ZnO) inorganic powder was slowly added while azimixing (300 rpm). Polyol wetting and natural polymer coating were performed simultaneously. The natural polymer may be present in 0.1-0.5% by weight, the hydrophobic ZnO (ZnO coated with alkylsilane) inorganic powder in up to 70% by weight, and the polyol in 29.5-49.9% by weight. The final product was in powder or paste form and was not dried.

[0079] Furthermore, to confirm whether natural polymer coating could be smoothly achieved even without polyol wetting, instead of polyol, CNF (Comparative Example 7) or HA (Comparative Example 8) was dispersed in water, and then hydrophobic ZnO (ZnO coated with alkylsilane) inorganic powder was slowly added while azimixing (300 rpm).

[0080] Table 2 shows the components constituting the inorganic powder dispersions of the examples and comparative examples. In Table 2, the component content of the inorganic powder dispersions of Examples 1-8 and Comparative Examples 2-5 is 70% by weight of hydrophobic ZnO (ZnO coated with alkylsilane), 29.5% by weight of polyol, and 0.5% by weight of natural polymer, relative to the total weight. Comparative Example 1 is hydrophobic ZnO (product name: MZX-508OTS) that is not wetted with polyol and is not coated with natural polymer. In Table 2, the component content of the inorganic powder dispersions of Comparative Examples 7-8 is 70% by weight of hydrophobic ZnO (ZnO coated with alkylsilane), 29.5% by weight of water, and 0.5% by weight of natural polymer, relative to the total weight.

[0081] [Table 2]

[0082] In order to confirm whether the surface of the hydrophobic ZnO inorganic powder in the inorganic powder dispersion was effectively coated with a hydrophilic substance, a water-soluble red dye (TPP RED NO.227, display name: RED 33 (CI 17200) 2,7-Naphthalenedisulfonic acid, 5-amino-4-hydroxy-3-(phenylazo), disodium salt) was added to each of the inorganic powder dispersions produced by the above manufacturing method, mixed, and checked to see whether the red dye was adsorbed onto the powder. As shown in Figure 3, the water-soluble red dye was adsorbed onto the surface of the inorganic powder dispersions of Examples 1 to 8. On the other hand, the water-soluble red dye was not adsorbed onto the surface of the hydrophobic ZnO powder of Comparative Example 1, which was not wetted with polyol and not coated with a natural polymer (leftmost part of Figure 3). In Figure 3, the upper photographs show the results immediately after the addition of the water-soluble red dye (the black areas in the three petri dishes in the upper part of Figure 3 represent the water-soluble red dye), while the lower photographs show the results after a certain period of time has elapsed since the addition of the water-soluble red dye (indicated in black in the lower part of Figure 3, the petri dish for Comparative Example 1 shows a state where the water-soluble red dye has not yet been adsorbed onto the powder surface. In the petri dishes for Examples 2 and 6 in the lower part of Figure 3, the petri dishes show a state where the water-soluble red dye (indicated in black in Figure 3) has been well adsorbed onto the powder surface (indicated in light gray). Furthermore, in Comparative Examples 7 and 8, which were obtained by mixing hydrophobic ZnO inorganic powder and polymer without using polyol, the hydrophilic polymer was not effectively coated onto the hydrophobic ZnO inorganic powder.

[0083] 2. Evaluation of the water dispersibility of inorganic powder dispersions (examples and comparative examples) The water dispersibility of the inorganic powder dispersion obtained in Experimental Example 2, "1. Production of Inorganic Powder Dispersion," was evaluated.

[0084] Specifically, the inorganic powder dispersions of Examples 1-8, Comparative Examples 1-5, and Comparative Examples 7 and 8 were dispersed in water using an agitator (300 rpm, 10 minutes) so that the hydrophobic ZnO concentration was 10% (i.e., the powders of the Examples and Comparative Examples were dispersed in 45 mL of water so that 5 g of hydrophobic ZnO could be mixed in).

[0085] The evaluation results of the water dispersibility of the examples and comparative examples are shown in Table 2 (rightmost column). As shown in Table 2 and Figure 2, the inorganic powder dispersions (Examples 1-8) obtained by coating hydrophobic ZnO powder dispersed and moistened in a polyol containing adjacent diols with a natural polymer (CNF or HA) showed excellent water dispersibility. In contrast, the inorganic powder dispersions (Comparative Examples 2-5) obtained by coating hydrophobic ZnO powder moistened with a polyol without adjacent diols, such as 1,3PG or 1,3BG, with a natural polymer (CNF or HA) showed poor dispersibility in water, resulting in phase separation. Furthermore, as shown in Figure 2, the hydrophobic ZnO powder (Comparative Example 1) that was neither moistened with a polyol nor coated with a natural polymer showed poor dispersibility in water (leftmost part of Figure 2). As shown in Figure 5, the dispersions obtained by mixing hydrophobic ZnO powder and natural polymers without using polyols (Comparative Examples 7 and 8) exhibited poor dispersibility in water and underwent phase separation (see Figure 5; the left figure shows Comparative Example 7, and the right figure shows Comparative Example 8).

[0086] [Experimental Example 3] Manufacturing of UV-blocking cosmetic compositions containing inorganic powder dispersions and evaluation of improved washability. Cosmetic compositions for UV protection containing hydrophobic ZnO were prepared using the compositions shown in Table 3 below, and cosmetic compositions for UV protection containing the dispersions of the examples in Table 2 were prepared. Subsequently, their cleaning power was compared. In Table 3, the hydrophobic ZnO is Comparative Example 1, and the hydrophilic ZnO is Example 2.

[0087] [Table 3]

[0088] A cosmetic composition for UV protection, manufactured according to the composition in Table 3, was applied to the skin (a test area of ​​3 x 3 cm) at a concentration of 2 ug / cm³. 2 Each (that is, 9cm in size 3x3cm) 2A cosmetic composition (18 ug) was applied to each test site, and after a certain period of time, it was rinsed off with water to evaluate the cleansing power. After washing, the average skin tone lightness (L*) value at each time point in the test site was analyzed, and the cleansing rate (%) was calculated using the following formula (1).

[0089]

number

[0090] As a result, the cleaning power of the cosmetic composition of Comparative Example 6, which contained hydrophobic ZnO, was low at 38.75%. On the other hand, the cleaning power of the cosmetic composition of Example 9, which contained the inorganic powder dispersion of the example (i.e., a form in which hydrophobic ZnO inorganic powder is dispersed in a compound containing an adjacent diol and a natural polymer; hydrophilic ZnO), was excellent at 97.61% (Figure 4).

Claims

1. An inorganic powder dispersion comprising a compound containing an adjacent diol, a natural polymer, and an inorganic powder.

2. The inorganic powder dispersion according to claim 1, wherein the inorganic powder is dispersed and wet in a compound containing the adjacent diol, and the wet inorganic powder is coated with the natural polymer.

3. The inorganic powder dispersion according to claim 1, wherein the compound containing the adjacent diol is at least one selected from the group consisting of 1,2-butylene glycol, 2,3-butylene glycol, 1,2-pentanediol, and 1,2-hexanediol.

4. The inorganic powder dispersion according to claim 1, wherein the inorganic powder is at least one selected from the group consisting of zinc oxide, titanium dioxide, and iron oxide.

5. The inorganic powder dispersion according to claim 1, wherein the inorganic powder is a hydrophobic inorganic powder.

6. The inorganic powder dispersion according to claim 1, wherein the inorganic powder is surface-modified with at least one hydrophobic compound selected from the group consisting of silicone compounds and saturated fatty acids of C8 to C28.

7. The inorganic powder dispersion according to claim 6, wherein the silicone compound is an alkylsilane, octyltriethoxysilane, or triethoxycaprylylsilane.

8. The inorganic powder dispersion according to claim 6, wherein the saturated fatty acid C8 to C28 is stearic acid.

9. The inorganic powder dispersion according to claim 1, wherein the natural polymer is a hydrophilic natural polymer.

10. The inorganic powder dispersion according to claim 1, wherein the natural polymer is at least one selected from the group consisting of cellulose, cellulose nanofibers, and hyaluronic acid.

11. The inorganic powder dispersion according to claim 1, wherein the inorganic powder dispersion contains 10 to 50% by weight of the compound containing the adjacent diol, based on the total weight.

12. The inorganic powder dispersion according to claim 1, wherein the inorganic powder dispersion contains 0.01 to 10% by weight of the natural polymer based on the total weight.

13. A composition for blocking ultraviolet light, comprising an inorganic powder dispersion according to any one of claims 1 to 12.

14. The ultraviolet blocking composition according to claim 13, wherein the composition is an external preparation composition or a cosmetic composition.

15. The ultraviolet blocking composition according to claim 13, wherein the composition is an oil-in-water emulsion formulation or a water-dispersible formulation.

16. The ultraviolet blocking composition according to claim 13, wherein the composition does not contain a surfactant.

17. The ultraviolet blocking composition according to claim 13, wherein the composition contains 1 to 50% by weight of the inorganic powder dispersion based on the total weight.

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