Hydroxyapatite-supported porous silica particles, method for producing hydroxyapatite-supported porous silica particles, and composition containing hydroxyapatite-supported porous silica particles

Abstract

The present invention provides a novel and environmentally friendly particulate material that exhibits a smoothness like that of urethane particles. Hydroxyapatite-supporting porous silica particles according to the present invention have hydroxyapatite supported on the surface and in the pore interiors of spherical porous silica particles and have a circularity of at least 0.760.

Description

[Technical Field]

[0001] The present invention relates to hydroxyapatite-supported porous silica particles in which hydroxyapatite is supported on porous silica particles, a method for producing the hydroxyapatite-supported porous silica particles, and a composition containing the hydroxyapatite-supported porous silica particles. [Background technology]

[0002] Particulate materials are used in various fields as fillers, etc. For example, in the field of cosmetics, spherical fine particle powders are blended into cosmetics for the purposes of improving the smoothness and feel of the cosmetics on the skin, covering blemishes, freckles, acne, etc., improving skin tone and makeup effects, etc.

[0003] Raw materials for fine particle powders used in cosmetics include extender pigments such as talc, mica, kaolin, silica, calcium carbonate, and aluminum oxide, color pigments such as titanium oxide and zinc oxide, and synthetic resins such as urethane, silicone, nylon, acrylic, polystyrene, and polyethylene. Since inorganic materials such as extender pigments and color pigments do not provide a good feel when blended into powder cosmetics such as foundations and body powders, the use of fine particle powders made of synthetic resins has been investigated.

[0004] For example, Patent Document 1 proposes a cosmetic containing spherical polyurethane fine powder with an average particle size of 30 μm or less. Patent Document 1 describes that the spherical polyurethane fine powder is highly elastic, and that blending it into a cosmetic provides excellent coverage, adhesion, adsorption, and mixability, and that the cosmetic feels soft and smooth when applied to the skin. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 5-262622 Summary of the Invention [Problem to be solved by the invention]

[0006] Microplastic beads, which are made by atomizing synthetic resins, have the characteristics of being light, persistent, and hydrophobic. Therefore, they are easily released into the environment without being adequately removed in sewage treatment facilities, easily ingested by marine organisms, and easily bioaccumulated. Furthermore, their tendency to adsorb hydrophobic harmful substances makes them susceptible to the incorporation of harmful substances into the food chain. In recent years, concerns have been raised about the impact of these microplastic beads on the natural environment. Therefore, global efforts are being made to reduce the amount of microplastics produced, and particulate materials that can replace microplastic beads are needed.

[0007] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a new particulate material that has a feel similar to that of urethane particles, specifically, that reduces the coefficient of dynamic friction when applied to the skin, imparts a smooth, slippery feeling (powdery feel), and has a non-gritty, smooth feel, and is also environmentally friendly. [Means for solving the problem]

[0008] As a result of extensive research, the present inventors have found that the above problems can be solved by supporting hydroxyapatite on spherical porous silica particles with high circularity, and have thus completed the present invention. The present invention provides the following <1> ~ <10> It is related to.

[0009] <1> Hydroxyapatite-supported porous silica particles, in which hydroxyapatite is supported on the surfaces and inner surfaces of the pores of spherical porous silica particles, and which have a circularity of 0.760 or more. <2> The amount of the hydroxyapatite supported in the hydroxyapatite-supporting porous silica particles is 0.1 to 80 mass %. <1> The hydroxyapatite-supporting porous silica particles according to claim 1. <3> The maximum count number (C) in the range of 2θ=31.5 to 32.5° corresponding to the (211) plane of the hydroxyapatite in the XRD pattern of the hydroxyapatite-supported porous silica particles HAp ) and the maximum count number (C) within the range of 2θ=28.0 to 29.0° corresponding to the (111) plane of cerium oxide in the XRD pattern of cerium oxide separately measured as an external standard. CeO2 ) and the ratio (C HAp / C CeO2 ) is 1.0 or less, <1> or <2> The hydroxyapatite-supporting porous silica particles according to claim 1. <4> In a cross-sectional image of the hydroxyapatite-supporting porous silica particle observed by SEM-EDX, when the maximum diameter in a specific direction in the cross-section is divided into three equal parts in the radial direction into first to third parts, three points are arbitrarily selected from within a circle whose diameter is the diameter length of the second part located in the center and three points are arbitrarily selected from within a circle whose diameter is the diameter length of the first or third part, and when point analysis is performed on these three points, the following conditions (1) to (3) are satisfied: <1> ~ <3> 1. The hydroxyapatite-supporting porous silica particles according to any one of the above. (1) The average intra-particle coefficient of variation of calcium peak signal intensity relative to silicon peak signal intensity is 0 to 50%. (2) The average intra-particle coefficient of variation of the phosphorus peak signal intensity relative to the silicon peak signal intensity is 0 to 50%. (3) The average intra-particle coefficient of variation of calcium peak signal intensity relative to phosphorus peak signal intensity is 0 to 50%. <5> The average particle diameter (D 50 ) is 1 to 500 μm. <1> ~ <4> 1. The hydroxyapatite-supporting porous silica particles according to any one of the above. <6> The pore volume is 0.05 to 2.50 mL / g. <1> ~ <5> 1. The hydroxyapatite-supporting porous silica particles according to any one of the above. <7> the amount of oleic acid adsorbed when 0.5 g of the hydroxyapatite-supported porous silica particles is mixed with 5 g of a simulated sebum solution having an oleic acid concentration of 16% by mass is 60 mg / g or more; <1> ~ <6> 1. The hydroxyapatite-supporting porous silica particles according to any one of the above.

[0010] <8> The aforementioned <1> ~ <7> A method for producing the hydroxyapatite-supported porous silica particles according to any one of the above, A method for producing hydroxyapatite-supporting porous silica particles, comprising contacting spherical porous silica particles having a circularity of 0.560 or more with a calcium source and a phosphorus source to produce hydroxyapatite. <9> bringing the spherical porous silica particles into contact with a first solution containing the calcium source to fix calcium on the surfaces and inner pore surfaces of the spherical porous silica particles; and bringing the spherical porous silica particles to which the calcium has been fixed into contact with a second solution containing the phosphorus source, and reacting the calcium with the phosphorus to produce hydroxyapatite. <8> 1. A method for producing hydroxyapatite-supporting porous silica particles according to claim 1. <10> The aforementioned <1> ~ <7> A skin composition, an oral composition, an adsorbent composition or a pharmaceutical composition, comprising the hydroxyapatite-supported porous silica particles according to any one of the above. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide hydroxyapatite-supported porous silica particles that have a texture similar to that of urethane particles. Furthermore, since hydroxyapatite is a compound that occurs in nature, as evidenced by its role as a major component of teeth and bones, and silica is also a compound that occurs in nature, the present invention is also environmentally friendly. Therefore, the present invention is suitable for use in skin compositions such as cosmetics, oral compositions, adsorbent compositions, pharmaceutical compositions, and the like. [Brief explanation of the drawings]

[0012] [Figure 1]FIG. 1 shows scanning electron microscope (SEM) images of the hydroxyapatite-supporting porous silica particles obtained in Example 1, where (a) is a surface SEM image and (b) is a cross-sectional SEM image. [Figure 2] FIG. 2 shows energy dispersive X-ray analysis images (EDX images) of the hydroxyapatite-supported porous silica particles obtained in Example 1, where (a) is a cross-sectional SEM image of the particles subjected to EDX imaging, and (b) is a cross-sectional EDX image of silica (Si). [Figure 3] FIG. 3 shows energy dispersive X-ray analysis images (EDX images) of the hydroxyapatite-supported porous silica particles obtained in Example 1, where (a) is a cross-sectional EDX image of calcium (Ca) and (b) is a cross-sectional EDX image of phosphorus (P). DETAILED DESCRIPTION OF THE INVENTION

[0013] The present invention will be described below, but the present invention is not limited to the examples in the following description. In this specification, "mass" is synonymous with "weight."

[0014] (Hydroxyapatite-supported porous silica particles) The hydroxyapatite-supporting porous silica particles of the present invention are spherical porous silica particles having hydroxyapatite supported on the surfaces and inner surfaces of the pores, and have a circularity of 0.760 or more. In this specification, the "surface" of a spherical porous silica particle refers to the part that defines the outer shape of the spherical porous silica particle, i.e., the outer surface. The "inner pore surface" of a spherical porous silica particle refers to the part that defines the pores of the spherical porous silica particle. "Supported" refers to a state in which hydroxyapatite is attached to or bonded to the surface and inner pore surfaces of the spherical porous silica particle. The circularity indicates the degree of surface irregularity of the hydroxyapatite-supported porous silica particle; the closer the circularity is to 1, the smaller the particle surface irregularity, i.e., the more spherical the particle is.

[0015] The hydroxyapatite-supported porous silica particles of the present invention have a spherical or nearly spherical shape, and the support of hydroxyapatite on the particle surface improves the smooth and silky feel when applied to the skin, and also has a higher refractive index than silica alone. Furthermore, the support of hydroxyapatite on the inner surfaces of the pores enhances the adsorption of free fatty acids such as oleic acid. Therefore, when incorporated into cosmetics, for example, they provide an excellent feel on the skin, suppress the appearance of pores, blemishes, freckles, etc., and further suppress acne by adsorbing free fatty acids secreted from sebum. In other words, the hydroxyapatite-supported porous silica particles of the present invention, when applied to the skin, have excellent soft-focus properties and are expected to have skin care benefits. Furthermore, because the base material is silica, they are environmentally friendly.

[0016] From the viewpoint of improving the feel of the material, the circularity of the hydroxyapatite-supported porous silica particles is 0.760 or more, preferably 0.800 or more, more preferably 0.820 or more, even more preferably 0.850 or more, and particularly preferably 0.900 or more. There is no upper limit, but it is most preferably 1. The circularity can be calculated by determining the area and perimeter of particles from an image obtained by a particle image analyzer (for example, "FPIA-3000S" (trade name) manufactured by Sysmex Corporation) using image analysis software attached to the device, and then applying the results to the following formula. Circularity = perimeter of a circle with the same projected area / perimeter of the particle Perimeter of a circle with the same projected area: When a particle is observed from directly above, the area of ​​the particle's shadow projected onto the plane below is calculated, and the length of the outline of that circle is calculated. Particle perimeter: The length of the outline of the particle's shadow projected onto a plane below when the particle is observed from directly above

[0017] The hydroxyapatite-supported porous silica particles of the present invention preferably have a hydroxyapatite loading of 0.1 to 80% by mass. When the hydroxyapatite loading is 0.1% by mass or more, the tactile feel of the particles can be made similar to that of urethane particles, improving the feel when attached to the skin. Furthermore, the amount of free fatty acid adsorption can be increased. When the hydroxyapatite loading is 80% by mass or less, the oil absorption capacity of the hydroxyapatite-supported porous silica particles can be sufficiently ensured. The hydroxyapatite loading is more preferably 10% by mass or more, even more preferably 20% by mass or more, particularly preferably 25% by mass or more, and more preferably 50% by mass or less, even more preferably 40% by mass or less, and particularly preferably 35% by mass or less. The amount of hydroxyapatite supported can be measured by high-frequency inductively coupled plasma atomic emission spectroscopy (ICP-AES) using an ICP atomic emission spectrometer (for example, "ICPE-9000" (trade name) manufactured by Shimadzu Corporation).

[0018] In the present invention, hydroxyapatite is supported on the surfaces and inner pore surfaces of spherical porous silica particles. In other words, hydroxyapatite is distributed on the surfaces and inside the spherical porous silica particles. It is preferable that hydroxyapatite is distributed almost uniformly on the surfaces of the particles and inner pore surfaces. In this specification, "almost uniformly distributed" means that hydroxyapatite is distributed almost uniformly on the surfaces of the spherical silica particles and inner pore surfaces without being localized in some areas.

[0019] The fact that hydroxyapatite is supported on the surface of the spherical porous silica particles can be confirmed by a surface SEM image taken using an SEM (Scanning Electron Microscope). Furthermore, the fact that hydroxyapatite is supported on the inner pore surfaces of spherical porous silica particles can be confirmed by cross-sectional SEM images taken using SEM and cross-sectional EDX images taken using EDX (Energy Dispersive X-ray Spectroscopy) (SEM-EDX).

[0020] In the present invention, when a cross-sectional image of a hydroxyapatite-supported porous silica particle is observed by SEM-EDX, and the maximum diameter in a specific direction on the cross-section is divided into three equal parts in the radial direction into first to third parts, point analysis is performed at three points arbitrarily selected from within a circle whose diameter is the diameter length of the central second part and at three points arbitrarily selected from within a circle whose diameter is the diameter length of the first or third part, and it is preferable that the following conditions (1) to (3) are satisfied. (1) The average intra-particle coefficient of variation of calcium peak signal intensity relative to silicon peak signal intensity (average intra-particle coefficient of variation of Ca / Si) is 0 to 50%. (2) The average intra-particle coefficient of variation of the phosphorus peak signal intensity relative to the silicon peak signal intensity (average intra-particle coefficient of variation of P / Si) is 0 to 50%. (3) The average intra-particle coefficient of variation of calcium peak signal intensity relative to phosphorus peak signal intensity (average intra-particle coefficient of variation of Ca / P) is 0 to 50%.

[0021] When the cross section of a hydroxyapatite-loaded porous silica particle is observed with SEM-EDX, the results of point analysis of six points in a specified region satisfy the above conditions (1) to (3), which indicates that hydroxyapatite is loaded on the pore surfaces inside the particle and that the hydroxyapatite is distributed and loaded almost uniformly. The average intra-particle coefficient of variation of Ca / Si is more preferably 40% or less, even more preferably 30% or less, and particularly preferably 20% or less. Furthermore, since it can be seen that the smaller the average intra-particle coefficient of variation, the higher the uniformity of hydroxyapatite within the particles, the better the lower limit that the average intra-particle coefficient of variation of Ca / Si can be, and therefore, 0% is the lower limit that The average intra-particle coefficient of variation of P / Si is more preferably 40% or less, even more preferably 30% or less, and particularly preferably 25% or less. The lower limit of the average intra-particle coefficient of variation of P / Si is preferably 0%. The average intra-particle coefficient of variation of Ca / P is more preferably 40% or less, even more preferably 30% or less, and particularly preferably 25% or less. The lower limit of the average intra-particle coefficient of variation of Ca / P is preferably 0%.

[0022] Furthermore, cross-sectional SEM images confirmed that the particles had a porous silica skeletal structure, and cross-sectional EDX images showed that phosphorus and calcium were distributed in a manner similar to that of silica, which indicated both visually and qualitatively that hydroxyapatite was supported on the surfaces of the pores inside the particles and that the hydroxyapatite was distributed and supported almost uniformly.

[0023] In this embodiment, it is preferable that the coefficient of variation (inter-particle coefficient of variation) of the intra-particle average values ​​of the peak signal intensities of silicon, phosphorus and calcium among the hydroxyapatite-supporting porous silica particles is small. That is, as described above, when a cross-sectional image of a hydroxyapatite-supported porous silica particle is observed by SEM-EDX, and the maximum diameter in a specific direction on the cross-section of each particle is divided into three equal parts in the radial direction into first to third parts, point analysis is performed at three points arbitrarily selected from within a circle whose diameter is the diameter length of the central second part and at three points arbitrarily selected from within a circle whose diameter is the diameter length of the first or third part, and it is preferable that the following conditions (4) to (6) are satisfied. (4) The coefficient of variation of the intra-particle average value of the calcium peak signal intensity relative to the silicon peak signal intensity (the inter-particle coefficient of variation of Ca / Si) is 0 to 50%. (5) The coefficient of variation of the intra-particle average value of the peak signal intensity of phosphorus relative to the peak signal intensity of silicon (inter-particle coefficient of variation of P / Si) is 0 to 50%. (6) The coefficient of variation of the intra-particle average value of the calcium peak signal intensity relative to the phosphorus peak signal intensity (the inter-particle coefficient of variation of Ca / P) is 0 to 50%.

[0024] The interparticle coefficient of variation of Ca / Si is more preferably 45% or less, and even more preferably 40% or less. Furthermore, since it is understood that the smaller the interparticle coefficient of variation, the higher the uniformity of hydroxyapatite loading between particles, the lower limit of the interparticle coefficient of variation of Ca / Si should be 0%. The inter-particle coefficient of variation of P / Si is more preferably 45% or less, and even more preferably 40% or less. The lower limit of the inter-particle coefficient of variation of P / Si is preferably 0%. The inter-particle coefficient of variation of Ca / P is more preferably 40% or less, further preferably 35% or less, and particularly preferably 30% or less. The lower limit of the inter-particle coefficient of variation of Ca / P is preferably 0%.

[0025] The hydroxyapatite-supported porous silica particles of the present invention preferably have a pore volume of 0.05 to 2.50 mL / g. If the pore volume is less than 0.05 mL / g, the particles may not fully function as porous particles. If the pore volume is 2.50 mL / g or less, the strength of the particles is maintained. The pore volume of the hydroxyapatite-supported porous silica particles is more preferably 0.10 mL / g or more, even more preferably 0.50 mL / g or more, and particularly preferably 0.80 mL / g or more, and more preferably 2.00 mL / g or less, even more preferably 1.60 mL / g or less, and particularly preferably 1.30 mL / g or less. The pore volume can be calculated by the BJH method using a nitrogen adsorption method.

[0026] The specific surface area of ​​the hydroxyapatite-supporting porous silica particles of the present invention is 10 to 800 m 2 / g. The specific surface area is preferably 10 m 2 / g or more, hydroxyapatite can be sufficiently supported. 2If the specific surface area exceeds 50m / g, sufficient particle strength may not be maintained. 2 / g or more is more preferable, and 100m 2 / g or more is more preferable, and 200m 2 / g or more is particularly preferred, and 700m 2 / g or less is more preferable, and 600m 2 / g or less is more preferable, and 400m 2 / g or less is particularly preferred. The specific surface area can be calculated by the BET method using a nitrogen adsorption method.

[0027] The average particle size (50% particle size, D) in the cumulative particle size distribution based on the volume of the hydroxyapatite-supported porous silica particles of the present invention 50 The average particle diameter (D 50 When the average particle diameter (D) is 1 μm or more, aggregation is suppressed and sufficient dispersibility in the composition is easily ensured, and when it is 500 μm or less, the feel when blended in the composition is improved. 50 ) is more preferably 2 μm or more, even more preferably 3 μm or more, and more preferably 300 μm or less, even more preferably 100 μm or less, and particularly preferably 15 μm or less.

[0028] In addition, the 90% particle size (D 90 ) 10% particle size (D 10 ) to the ratio (D 90 / D 10 ) is preferably 1.0 to 7.0. 90 / D 10 When the ratio (D) is within the above range, a good feeling can be obtained when the composition is applied to the skin. 90 / D 10 ) is more preferably 1.5 or more, even more preferably 2.0 or more, and is more preferably 6.0 or less, even more preferably 5.5 or less.

[0029] Average particle diameter (D 50), and 90% particle size (D 90 ) 10% particle size (D 10 ) to the ratio (D 90 / D 10 ) was measured by the electrical detection zone method (Coulter counter method) in accordance with JIS Z 8832 (2010).

[0030] The hydroxyapatite-supported porous silica particles of the present invention preferably have a dynamic friction coefficient of 0.75 or less. When the dynamic friction coefficient is 0.75 or less, the particles slide with low resistance, improving the feel when they come into contact with the skin, thereby providing a smooth, slippery sensation. The dynamic friction coefficient is more preferably 0.60 or less, even more preferably 0.50 or less, and particularly preferably 0.40 or less. There is no particular restriction on the lower limit of the dynamic friction coefficient, but it is preferably 0.05 or more, more preferably 0.10 or more, and even more preferably 0.15 or more.

[0031] Furthermore, the standard deviation of the dynamic friction coefficient of the hydroxyapatite-supported porous silica particles is preferably less than 0.045. When the standard deviation of the dynamic friction coefficient is less than 0.045, the particles slide with even resistance, improving the feel when they come into contact with the skin, and thereby providing a smooth, slippery sensation. The standard deviation of the dynamic friction coefficient is more preferably 0.040 or less, even more preferably 0.035 or less, and particularly preferably 0.030 or less. There is no particular restriction on the lower limit of the standard deviation of the dynamic friction coefficient, but it is more preferably 0.001 or more, even more preferably 0.005 or more, and particularly preferably 0.008 or more.

[0032] The dynamic friction coefficient and the standard deviation of the dynamic friction coefficient can be measured using a static / dynamic friction measuring device (for example, "TL201Ts" (trade name) manufactured by Trinity Labs). Specifically, a urethane artificial finger is used as the contactor, and artificial leather is used as the coating substrate. The amount of adhesion to the artificial leather is 0.03 μL / mm in terms of bulk volume per unit area. 2The hydroxyapatite-supported porous silica particles are applied so that the surface is subjected to a load of 30 gf and a scanning distance of 40 mm to measure the coefficient of friction, and the average value in the range from 300 msec to 4,000 msec is taken as the coefficient of dynamic friction. The standard deviation in this range is taken as the standard deviation of the coefficient of dynamic friction.

[0033] Furthermore, the static friction coefficient of the hydroxyapatite-supported porous silica particles of the present invention is preferably 0.75 or less. When the static friction coefficient is 0.75 or less, the particles begin to slide with low resistance, improving the feel when they come into contact with the skin. The static friction coefficient is more preferably 0.70 or less, even more preferably 0.60 or less, and particularly preferably 0.50 or less. There is no particular lower limit for the static friction coefficient, but it is more preferably 0.01 or more, even more preferably 0.05 or more, and particularly preferably 0.10 or more. The static friction coefficient can be measured using the static / dynamic friction measuring device. Specifically, the friction coefficient is measured in the same manner as above, and the maximum value in the range of 0 msec to 300 msec is defined as the static friction coefficient.

[0034] The hydroxyapatite-supported porous silica particles of the present invention preferably have an oil absorption of 20 to 500 mL / 100 g. If the oil absorption is less than 20 mL / 100 g, the particles will not be able to fully function as porous particles, and if it exceeds 500 mL / 100 g, sufficient particle strength may not be maintained. The oil absorption is more preferably 50 mL / 100 g or more, even more preferably 100 mL / 100 g or more, and more preferably 400 mL / 100 g or less, even more preferably 350 mL / 100 g or less, and particularly preferably 250 mL / 100 g or less. The oil absorption can be measured in accordance with JIS K 5101-13-1 (2004).

[0035] Furthermore, the hydroxyapatite-supported porous silica particles of the present invention preferably have an oleic acid adsorption capacity of 60 mg / g or more when 0.5 g of the hydroxyapatite-supported porous silica particles is mixed with 5 g of a simulated sebum solution containing 16% by mass of oleic acid. If the oleic acid adsorption capacity is 60 mg / g or more under the above conditions, the oleic acid secreted from the skin can be sufficiently adsorbed when the particles are incorporated into a cosmetic composition, thereby suppressing pore inflammation and dyskeratosis caused by oleic acid secretion, and thereby reducing the visibility of pores. The oleic acid adsorption capacity under the above conditions is more preferably 70 mg / g or more, even more preferably 100 mg / g or more, and particularly preferably 150 mg / g or more. Furthermore, while there is no particular upper limit, from the viewpoint of production costs, it is preferably 1000 mg / g or less, more preferably 900 mg / g or less, and even more preferably 850 mg / g or less.

[0036] Furthermore, the hydroxyapatite-supported porous silica particles of the present invention preferably have an oleic acid adsorption amount of 5.0 to 100 mg / g, more preferably 7.5 to 50 mg / g, and even more preferably 10 to 20 mg / g, when 0.5 g of the hydroxyapatite-supported porous silica particles are mixed with 5 g of a simulated sebum solution having an oleic acid concentration of 0.1 mass %. The hydroxyapatite-supported porous silica particles of the present invention preferably have an oleic acid adsorption amount of 30 to 300 mg / g, more preferably 40 to 200 mg / g, and even more preferably 70 to 100 mg / g, when 0.5 g of the hydroxyapatite-supported porous silica particles are mixed with 5 g of a simulated sebum solution having an oleic acid concentration of 1% by mass. Furthermore, the hydroxyapatite-supported porous silica particles of the present invention preferably have an oleic acid adsorption amount of 70 to 900 mg / g, more preferably 80 to 700 mg / g, and even more preferably 200 to 600 mg / g, when 0.5 g of the hydroxyapatite-supported porous silica particles are mixed with 5 g of a simulated sebum solution having an oleic acid concentration of 50% by mass.

[0037] The amount of oleic acid adsorbed can be determined by converting the results of an acid value measurement using an ethanolic potassium hydroxide solution. Specifically, 5 g of simulated sebum solution containing a predetermined concentration of oleic acid was mixed with 0.5 g of hydroxyapatite-loaded porous silica particles as the sample. After stirring for 48 hours, the mixture was centrifuged at 1,260 G (relative centrifugal acceleration, × g) for 10 minutes to obtain 2.5 g of supernatant. This supernatant was then added with 25 mL of an organic solvent (ethanol:THF = 1:2) and an appropriate amount of ethanolic phenolphthalein, and used as the titration target. A 200 mmol / L ethanolic potassium hydroxide solution, the titer of which had been determined in advance, was used as the titration solution, and the endpoint was the appearance of a reddish-purple color. The titer of the titration solution was determined from the amount required to neutralize 200 mmol / L hydrochloric acid. The amount of oleic acid adsorption was then calculated using the following formula (1). A control test was conducted using the simulated sebum solution alone, without the addition of hydroxyapatite-loaded porous silica particles, and the above procedure was repeated.

[0038]

number

[0039] In the above formula (1), the amount of reduction in acid value (mg / g) is calculated as follows.

[0040]

number

[0041] In the present invention, the amount of oleic acid adsorbed can be adjusted by adjusting the amount of hydroxyapatite supported.

[0042] The hydroxyapatite-supported porous silica particles of the present invention have a maximum count (C ) in the range of 2θ=31.5 to 32.5°, which corresponds to the (211) plane of hydroxyapatite in the XRD pattern. HAp) and the maximum count number (C) within the range of 2θ=28.0 to 29.0° corresponding to the (111) plane of cerium oxide in the XRD pattern of cerium oxide measured separately as an external standard. CeO2 ) and the ratio (C HAp / C CeO2 ) is preferably 1.0 or less. HAp / C CeO2 represents the crystallinity of the supported hydroxyapatite, and the ratio C HAp / C CeO2 If C is 1.0 or less, a high amount of oleic acid can be expected to be adsorbed. HAp / C CeO2 is preferably 1.0 or less, more preferably 0.75 or less, and even more preferably 0.50 or less. HAp / C CeO2 The lower limit of is not particularly limited, but is preferably 0.05 or more, more preferably 0.10 or more, and even more preferably 0.15 or more. The XRD pattern can be measured using, for example, a "D2 PHASER" (trade name) manufactured by Bruker.

[0043] The hydroxyapatite-supported porous silica particles of the present invention preferably have a haze of 1 to 40% when dispersed at a concentration of 5% by mass in a simulated sebum solution having an oleic acid concentration of 16% by mass. When the haze of the dispersion is 1% or more, the dispersion exhibits enhanced soft focus when incorporated into cosmetics, thereby providing a shielding effect against age spots, freckles, and the like. When the haze of the dispersion exceeds 40%, the skin tends to appear unnaturally white, like a white pigment, when used in cosmetics. The haze is more preferably 5% or more, even more preferably 10% or more, and more preferably 35% or less, even more preferably 30% or less. Haze can be measured using a haze meter (for example, "NDH-7000" (trade name) manufactured by Nippon Denshoku Industries Co., Ltd.).

[0044] The hydroxyapatite-supported porous silica particles of the present invention preferably have a PSF (Point Spread Function) half width of 1.2 to 2.4 μm. The PSF half width is an index showing the degree of refraction of a particle, and a higher value indicates a higher refraction. When the PSF half width is 1.2 μm or more, the refractive index is high and the particles exhibit excellent soft focus properties when incorporated into cosmetics. When the PSF half width is more than 2.4 μm, the particles tend to give the skin an unnatural whiteness similar to that of a white pigment when used in cosmetics. The PSF half width is more preferably 1.4 μm or more, and more preferably 2.0 μm or less.

[0045] The PSF half-width is calculated as follows. A measurement sample is prepared by sandwiching a dispersion of 0.38 g of a simulated sebum solution containing 16% oleic acid and 0.02 g of hydroxyapatite-supported porous silica particles between quartz plates to prevent air bubbles. The measurement sample is placed on a glass plate, and a digital camera is placed 3.0 cm from the surface of the measurement sample. An ISO resolution test chart No. 2 is placed 1.0 cm from the back of the measurement sample as a background. An image of the background is captured through the measurement sample. This image is subjected to blind deconvolution using image analysis software (e.g., "AutoQuantX3" (product name) manufactured by Media Cybernetics) to obtain a PSF (point spread function) image. A line profile is obtained at a 45-degree angle passing through the center of the obtained PSF image, and its half-width is taken as the PSF half-width.

[0046] In the present invention, the simulated sebum solution contains caprylic / capric triglyceride (A), octyldodecyl myristate (B), squalane (C), and oleic acid (D), and contains components A, B, and C in a mass ratio of approximately A:B:C of 43:29:12, respectively, and contains component D at a predetermined concentration.

[0047] (Method for producing hydroxyapatite-supported porous silica particles) Next, the method for producing the hydroxyapatite-supporting porous silica particles of the present invention will be described. The hydroxyapatite-supporting porous silica particles of the present invention are produced by contacting spherical porous silica particles having a circularity of 0.560 or more with a calcium source and a phosphorus source to form hydroxyapatite. By using the method of the present invention, hydroxyapatite can be supported on the surfaces and inner surfaces of the pores of the spherical porous silica particles, which serve as the base material, without substantially changing the shape of the spherical porous silica particles.

[0048] The method for producing hydroxyapatite-supporting porous silica particles of the present invention preferably comprises the following steps (I) and (II). (I) contacting the spherical porous silica particles with a first solution containing the calcium source to fix calcium on the surfaces and inner pore surfaces of the spherical porous silica particles (first step); (II) contacting the spherical porous silica particles to which the calcium has been fixed with a second solution containing the phosphorus source to react the calcium with phosphorus to produce hydroxyapatite (second step);

[0049] <(I) 1st step> Spherical porous silica particles are secondary particles in which primary particles of silicon dioxide gather to form a continuous network of fine pores, and the spherical porous silica particles used in the manufacturing method of the present invention have a circularity of 0.560 or more. When the circularity is 0.560 or more, the circularity of the resulting hydroxyapatite-supported porous silica particles is easily 0.760 or more. The circularity of the spherical porous silica particles is preferably 0.600 or more, more preferably 0.700 or more, even more preferably 0.800 or more, and particularly preferably 0.900 or more. There is no particular upper limit, but it is most preferably 1.

[0050] The spherical porous silica particles preferably have a pore volume of 0.05 to 2.50 mL / g. If the pore volume is less than 0.05 mL / g, the particles may not fully function as porous particles. If the pore volume is 2.50 mL / g or less, the strength of the particles is maintained. The pore volume of the spherical porous silica particles is more preferably 0.10 mL / g or more, even more preferably 0.70 mL / g or more, particularly preferably 1.50 mL / g or more, and more preferably 2.00 mL / g or less, even more preferably 1.80 mL / g or less, particularly preferably 1.60 mL / g or less.

[0051] The specific surface area of ​​spherical porous silica particles is 10 to 1000 m 2 / g. The specific surface area is preferably 10 m 2 / g or more, hydroxyapatite can be sufficiently supported. 2 If the specific surface area exceeds 50m / g, sufficient particle strength may not be maintained. 2 / g or more is more preferable, and 200m 2 / g or more is more preferable, and 500m 2 / g or more is particularly preferred, and 900m 2 / g or less is more preferable, and 2 / g or less is particularly preferred.

[0052] The average particle size (D) in the cumulative particle size distribution based on the volume of spherical porous silica particles 50 The average particle diameter (D 50 When the average particle diameter (D) is 1 μm or more, aggregation is suppressed and sufficient dispersibility in the composition is easily ensured, and when it is 500 μm or less, the feel when blended in the composition is improved. 50 ) is more preferably 2 μm or more, even more preferably 3 μm or more, and more preferably 300 μm or less, even more preferably 100 μm or less, and particularly preferably 15 μm or less.

[0053] The 90% particle size (D) in the cumulative particle size distribution based on the volume of spherical porous silica particles90 ) 10% particle size (D 10 ) to the ratio (D 90 / D 10 ) is preferably 1.0 to 5.0. 90 / D 10 When the ratio (D) is within the above range, a good feel can be obtained. 90 / D 10 ) is more preferably 1.5 or more, particularly preferably 2.0 or more, and more preferably 4.0 or less, even more preferably 3.5 or less.

[0054] The spherical porous silica particles preferably have an oil absorption of 20 to 500 mL / 100 g. If the oil absorption is less than 20 mL / 100 g, the particles may not be able to fully function as porous particles, and if it exceeds 500 mL / 100 g, the particles may not be able to maintain sufficient particle strength. The oil absorption is more preferably 50 mL / 100 g or more, even more preferably 200 mL / 100 g or more, and more preferably 450 mL / 100 g or less, and even more preferably 350 mL / 100 g or less.

[0055] Commercially available spherical porous silica particles can be used, for example, "H-52" (trade name, circularity 0.958, average particle diameter 5.0 μm, specific surface area 652 m) manufactured by AGC Si-Tech Co., Ltd. 2 / g, pore volume 1.59 mL / g, average pore diameter 9.8 nm, oil absorption 324 mL / 100 g).

[0056] Examples of calcium sources used in producing hydroxyapatite-supported porous silica particles include calcium hydroxide, calcium chloride, calcium oxide, calcium nitrate, calcium carbonate, calcium silicate, calcium acetate, calcium hypochlorite, calcium formate, calcium bicarbonate, and calcium sodium edetate. These may be used alone or in combination of two or more. Among these, calcium hydroxide and calcium chloride are preferred from the viewpoint of reducing the environmental load caused by by-products.

[0057] In the first step, a first solution containing a calcium source is brought into contact with spherical porous silica particles. Examples of solvents for the first solution include water, ethanol, and isopropyl alcohol. These may be used alone or in combination. Among these, water is preferred from the viewpoint of reducing the environmental impact of wastewater.

[0058] The concentration of the calcium source in the first solution is preferably 0.001 to 0.100 g / mL. A concentration within this range allows calcium to be uniformly immobilized on the surfaces of the spherical porous silica particles and on the inner surfaces of the pores, and also improves production efficiency. The concentration of the calcium source in the first solution is more preferably 0.010 g / mL or higher, even more preferably 0.020 g / mL or higher, particularly preferably 0.030 g / mL or higher, and more preferably 0.090 g / mL or lower, even more preferably 0.080 g / mL or lower, and particularly preferably 0.070 g / mL or lower.

[0059] The first solution may contain other components as long as they do not interfere with calcium adsorption, such as pH adjusters such as sodium hydroxide, potassium hydroxide, ammonia, and hydrochloric acid.

[0060] The method for contacting the spherical porous silica particles with the first solution is not particularly limited, and examples thereof include a method of immersing the spherical porous silica particles in the first solution, a method of dropping, spraying, or applying the first solution to the spherical porous silica particles, etc. Among these, from the viewpoints of simple operation and the expectation of uniform contact, the method of immersing the spherical porous silica particles in the first solution is preferred, and immersing the spherical porous silica particles in the first solution while stirring is more preferred.

[0061] The amount of the first solution to be brought into contact with the spherical porous silica particles is preferably 0.05 to 50 g per gram of spherical porous silica particles. When the amount of the first solution used per gram of spherical porous silica particles is 0.05 g or more, calcium can be uniformly fixed to the surfaces of the spherical porous silica particles and the inner surfaces of the pores, and production efficiency is improved. When the amount is 50 g or less, excess use of the first solution can be suppressed. The amount of the first solution used per gram of spherical porous silica particles is more preferably 1 g or more, even more preferably 3 g or more, and particularly preferably 5 g or more, and more preferably 30 g or less, even more preferably 20 g or less, and particularly preferably 10 g or less.

[0062] From the viewpoint of reactivity, the temperature when the spherical porous silica particles are brought into contact with the first solution is preferably 5 to 80°C. Within this temperature range, the reaction proceeds quickly. The contact temperature is more preferably 10°C or higher, even more preferably 15°C or higher, and particularly preferably 20°C or higher, and is more preferably 80°C or lower, even more preferably 70°C or lower, and particularly preferably 60°C or lower.

[0063] From the viewpoint of reactivity, the time for which the spherical porous silica particles are contacted with the first solution is preferably 0.1 to 24 hours. When the contact time is within this range, the reaction is sufficient, and calcium is fixed on the surface of the spherical porous silica particles and the inner surfaces of the pores. The reaction time is more preferably 1 hour or longer, particularly preferably 2 hours or longer, and more preferably 18 hours or shorter, particularly preferably 12 hours or shorter.

[0064] After the reaction, it is preferable to recover the spherical porous silica particles with calcium fixed on the surfaces and inner surfaces of the pores by filtration, wash them, and dry them.

[0065] The filtration method is not particularly limited, and examples thereof include natural filtration, reduced pressure filtration, and centrifugal filtration.

[0066] The washing method is not particularly limited, and washing may be continued until the calcium concentration in the filtrate becomes stable. Examples of washing liquids include water, ethanol, and isopropyl alcohol, and water is preferred.

[0067] Drying can be carried out naturally or by using a drying means such as a heater, for example, at 50 to 300°C, preferably 120 to 180°C, for 1 to 24 hours, preferably 12 to 18 hours.

[0068] <(II) 2nd process> In the second step, the calcium-immobilized spherical porous silica particles obtained in the first step (hereinafter also referred to as calcium-immobilized porous silica particles) are brought into contact with a second solution containing a phosphorus source.

[0069] Examples of phosphorus sources include phosphoric acid, triammonium phosphate, and diammonium hydrogen phosphate. Examples include ammonium dihydrogen phosphate, trisodium phosphate, disodium hydrogen phosphate, sodium dihydrogen phosphate, tripotassium phosphate, dipotassium hydrogen phosphate, and potassium dihydrogen phosphate. These may be used alone or in combination of two or more. Among these, phosphoric acid is preferred from the viewpoint of reducing the environmental impact of by-products.

[0070] In the second step, a second solution containing a phosphorus source is brought into contact with the spherical porous silica particles. Examples of the solvent for the second solution include water, ethanol, and isopropyl alcohol. These may be used alone or in combination of two or more. Among these, water is preferred from the viewpoint of reducing the environmental load caused by wastewater.

[0071] The concentration of the phosphorus source in the second solution is preferably 0.01 to 0.50 g / mL. A concentration of 0.01 g / mL or higher allows sufficient reaction with calcium immobilized on the surfaces of the spherical porous silica particles and the inner surfaces of the pores, improving production efficiency. Furthermore, if the phosphoric acid concentration exceeds 0.50 g / mL, the pH is low, which may dissolve the generated hydroxyapatite and result in insufficient loading. The concentration of the phosphorus source in the second solution is more preferably 0.02 g / mL or higher, particularly preferably 0.03 g / mL or higher, and more preferably 0.30 g / mL or lower, particularly preferably 0.20 g / mL or lower.

[0072] As mentioned above, if the phosphoric acid concentration is too high, there is a risk that the hydroxyapatite produced upon contact with the second solution will dissolve, and therefore the pH of the second solution is preferably 5.0 to 12.0. When the pH of the second solution is within this range, calcium and phosphorus can react to produce hydroxyapatite, and the produced hydroxyapatite will not dissolve. The pH after contact with the second solution is more preferably 6.0 or higher, particularly preferably 7.0 or higher, and more preferably 11.0 or lower, even more preferably 10.0 or lower, and particularly preferably 9.0 or lower.

[0073] The second solution may contain other components as long as they do not interfere with the formation of hydroxyapatite, such as pH adjusters such as sodium hydroxide, potassium hydroxide, ammonia, and hydrochloric acid.

[0074] The method for bringing the calcium-immobilized porous silica particles into contact with the second solution is not particularly limited, and examples thereof include the same methods as those exemplified in the above step 1. Alternatively, the second solution may be produced by adding a phosphorus source and, if necessary, other components to a slurry in which the calcium-immobilized porous silica particles obtained in step 1 are dispersed in a solvent. Among these, a method in which a phosphorus source is added to an aqueous slurry containing calcium-immobilized porous silica particles and the resulting slurry is immersed in the second solution is preferred from the viewpoints of ease of operation and the expectation of uniform contact. Furthermore, in order to prevent localized pH drops, it is more preferable to bring the calcium-immobilized porous silica particles into contact with the second solution under stirring.

[0075] The amount of the second solution to be brought into contact with the calcium-immobilized porous silica particles is preferably 0.05 to 50 g per gram of calcium-immobilized porous silica particles. When the amount of the second solution used per gram of calcium-immobilized porous silica particles is 0.05 g or more, it is possible to react with most of the calcium immobilized on the surfaces of the spherical porous silica particles and the inner surfaces of the pores. When the amount of the second solution used per gram of calcium-immobilized porous silica particles is 50 g or less, it is possible to prevent excessive use of the second solution. The amount of the second solution used is preferably 1 g or more, more preferably 3 g or more, and particularly preferably 5 g or more. It is more preferably 30 g or less, more preferably 20 g or less, and particularly preferably 10 g or less.

[0076] From the viewpoint of reactivity, the temperature when the second solution is brought into contact with the calcium-immobilized porous silica particles is preferably 5 to 80°C. Within this temperature range, the reaction proceeds quickly. The contact temperature is more preferably 10°C or higher, even more preferably 15°C or higher, and particularly preferably 20°C or higher, and is more preferably 80°C or lower, even more preferably 70°C or lower, and particularly preferably 60°C or lower.

[0077] From the viewpoint of reactivity, the time for which the calcium-immobilized porous silica particles are brought into contact with the second solution is preferably 0.1 to 24 hours. When the particles are brought into contact for a time within this range, the reaction is sufficient, and hydroxyapatite is produced on the surfaces of the spherical porous silica particles and on the inner surfaces of the pores. The reaction time is more preferably 1 hour or longer, particularly preferably 2 hours or longer, and more preferably 18 hours or shorter, particularly preferably 12 hours or shorter.

[0078] After the reaction, it is preferable to recover the hydroxyapatite-supporting porous silica particles of the present invention, in which hydroxyapatite has been formed on the surfaces and inside the pores, by filtration, and then wash and dry them. The filtration method, washing method and drying conditions can be the same as those in the first step.

[0079] The production of hydroxyapatite when calcium hydroxide is used as the calcium source and phosphoric acid is used as the phosphorus source will be described below. 1st step: SiO - + Ca 2+ → SiOCa + Second step: SiOCa + + 10H + → 10SiOH + 10Ca 2+ 10Ca 2+ + 6PO4 3- + 2OH - → Ca 10 (PO4)6(OH)2

[0080] The hydroxyapatite-supported porous silica particles of the present invention are suitable for use in, for example, skin compositions, oral compositions, adsorbent compositions, or pharmaceutical compositions. Examples of skin compositions include cosmetics such as foundation, body powder, and lipstick, hair washing products such as shampoo and conditioner, facial cleansers, and lotions. Examples of oral compositions include powdered toothpaste and toothpaste. Examples of adsorbent compositions include bone formation promoters. [Example]

[0081] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these. In the following description, the same components are used. Unless otherwise specified, "%" represents "% by mass." Examples 1 to 6 are working examples, Examples 7 to 12 are comparative examples, and Example 13 is a reference example.

[0082] <Evaluation method> The evaluations carried out on the particles of Examples 1 to 13 are shown below.

[0083] (Circularity) The circularity was measured by image analysis using a flow particle image analyzer "FPIA-3000S" (product name, manufactured by Sysmex Corporation). Specifically, the measurement conditions were a 20x high-magnification objective lens and an effective analysis number of 10,000 particles.

[0084] (Amount of hydroxyapatite supported) The amount of hydroxyapatite supported was measured by high-frequency inductively coupled plasma atomic emission spectroscopy (ICP-AES) using an ICP atomic emission analyzer "ICPE-9000" (trade name, manufactured by Shimadzu Corporation).

[0085] (Average particle diameter (D 50 ) and D 90 / D 10 ) Average particle diameter (D 50 ) and D 90 / D 10 The measurement was performed by an electrical sensing zone method using a precision particle size distribution analyzer "Multisizer3" (trade name, manufactured by Beckman Coulter, Inc.) The measurement conditions were as follows: aperture diameter 50 μm, aperture current 800, gain 4, and number of measurements 50,000 for Examples 1 to 6, 8 to 11, and 13; aperture diameter 100 μm, aperture current 1600, gain 2, and number of measurements 30,000 for Example 7; and aperture diameter 280 μm, aperture current 3200, gain 1, and number of measurements 30,000 for Example 12.

[0086] (specific surface area, pore volume and average pore diameter) The specific surface area, pore volume, and average pore diameter were determined by the BET method and the BJH method based on the nitrogen adsorption method using a specific surface area and pore distribution measuring device "BELSORP-mini II" (product name, manufactured by Microtrac-Bell Corporation).

[0087] (Crystallinity index (C HAp / C CeO2 )) The maximum count (C) of each particle in the range of 2θ = 31.5 to 32.5°, which corresponds to the (211) plane of hydroxyapatite in the XRD pattern, is HAp ) and the maximum count (C) within the range of 2θ = 28.0 to 29.0°, which corresponds to the (111) plane in the XRD pattern of cerium oxide as an external standard. CeO2 ) and the ratio (C HAp / C CeO2 For the measurement, an X-ray diffractometer ("D2 PHASER" (trade name) manufactured by Bruker) was used. Specifically, a glass sample stage with a 0.2 mm deep groove was filled with particles so that the surface was smooth, and the sample stage was placed in an X-ray diffraction instrument. Measurements were performed using Cu as the X-ray source, an X-ray output of 300 W, a divergence slit of 1.0 mm, an air scatter screen of 3 mm, a Soller slit of 4°, a Ni filter of 0.25 mm, a Bruker semiconductor detector "SSD160-2" (trade name), a detector aperture width of 5.8°, a step width of 0.1°, a step time of 2 seconds, and a sample stage rotation speed of 10 rpm. The maximum count within the range of 2θ = 31.5 to 32.5° was designated as C. HAp As an external standard, cerium oxide ("CeO2 Powder ca. 0.2 μm" manufactured by Kojundo Chemical Laboratory, purity 99.99% or more, particle size 0.2 μm) was measured under the same conditions, and the maximum count within the range of 2θ = 28.0 to 29.0° was defined as C CeO2 The obtained C HAp and C CeO2 From the value of HAp / C CeO2 asked for.

[0088] (Oil absorption amount) The oil absorption was measured according to JIS K 5101-13-1 (2004).

[0089] (Surface SEM, cross-sectional SEM and cross-sectional EDX) Surface SEM images were taken using a field emission scanning electron microscope "JSM-6701F" (manufactured by JEOL Ltd.) at an acceleration voltage of 1 kV and an emission current of 10 μA. The sample was fixed to carbon tape and then coated with platinum (Pt). Cross-sectional SEM images were taken under the same conditions as for surface SEM. The specimen was immersed in an epoxy resin precursor, solidified, and then cut with a diamond knife and fixed on carbon tape. Cross-sectional EDX was performed using an energy dispersive X-ray analyzer "EDAX Genesis" (manufactured by AMETEK) attached to the SEM, and silicon, calcium, and phosphorus elements were analyzed at an acceleration voltage of 15 kV, an emission current of 10 μA, and an accumulation time of 200 seconds.

[0090] (Measurement of intra-particle uniformity of hydroxyapatite) The intra-particle uniformity of hydroxyapatite was measured by the following procedure. In the cross-sectional image of the hydroxyapatite-supported porous silica particles observed by the SEM-EDX, the maximum diameter in a specific direction in the cross-section was divided into three equal parts in the radial direction into first to third parts, and three points were arbitrarily selected from within a circle whose diameter was the diameter length of the second part located in the center, and three points were arbitrarily selected from within a circle whose diameter was the diameter length of the first or third part, for a total of six points. Point analysis was performed using an energy dispersive X-ray analyzer under the same conditions as in the previous section. Based on the results, the peak signal intensities of silicon, phosphorus, and calcium were obtained. Next, the peak signal intensity of calcium relative to the peak signal intensity of silicon, the peak signal intensity of phosphorus relative to the peak signal intensity of silicon, and the peak signal intensity of calcium relative to the peak signal intensity of phosphorus were calculated, and the coefficient of variation at six points was calculated for each peak signal intensity ratio. The above series of calculations of the coefficient of variation were performed on three randomly selected particles, and the average of each coefficient of variation was calculated and used as the average intra-particle coefficient of variation. If this value is close to 0%, it means that the intra-particle uniformity of hydroxyapatite is high.

[0091] (Measurement of interparticle uniformity of hydroxyapatite) The interparticle uniformity of hydroxyapatite was measured by the following procedure. In a cross-sectional image of a hydroxyapatite-supported porous silica particle observed by SEM-EDX, the maximum diameter in a specific direction in the cross-section was divided into three equal parts in the radial direction into first to third parts, and three points were arbitrarily selected from within a circle whose diameter was the diameter length of the second part located in the center, and three points were arbitrarily selected from within a circle whose diameter was the diameter length of the first or third part, for a total of six points. Point analysis was performed using an energy dispersive X-ray analyzer under the same conditions as in the previous section. Based on the results, the peak signal intensities of silicon, phosphorus, and calcium were obtained. Next, the peak signal intensity of calcium relative to the peak signal intensity of silicon, the peak signal intensity of phosphorus relative to the peak signal intensity of silicon, and the peak signal intensity of calcium relative to the peak signal intensity of phosphorus were calculated, and the average value over six points was calculated for each peak signal intensity ratio. The above series of average value calculations was performed on three randomly selected particles, and the coefficient of variation of each average value was calculated and used as the inter-particle coefficient of variation. If this value is close to 0%, it means that the inter-particle uniformity of hydroxyapatite is high.

[0092] (Oleic acid adsorption amount) The amount of oleic acid adsorbed was determined by converting the results of an acid value measurement using an ethanolic potassium hydroxide solution. As the simulated sebum solutions, simulated sebum solutions 1 to 4 shown in Table 1 below were used. 0.5 g of particles from each example was mixed with 5 g of simulated sebum solution, and the mixture was stirred for 48 hours. After stirring, the mixture was centrifuged at 1,260 G (relative centrifugal acceleration, × g) for 10 minutes to obtain 2.5 g of supernatant. 25 mL of an organic solvent (ethanol:THF = 1:2) and an appropriate amount of ethanolic phenolphthalein were added to this supernatant and used for titration. A 200 mmol / L ethanolic potassium hydroxide solution, the titer of which had been determined in advance, was used as the titration solution, and the endpoint was the time when the solution turned reddish-purple. The titer of the titration solution was determined from the amount required to neutralize 200 mmol / L hydrochloric acid. The amount of oleic acid adsorbed was calculated using the following formula (1): A control test was conducted by carrying out the above procedure using only the simulated sebum solution without mixing any particles.

[0093]

number

[0094] In the above formula (1), the amount of reduction in acid value (mg / g) was calculated as follows.

[0095]

number

[0096] [Table 1]

[0097] (Dynamic friction coefficient, standard deviation of dynamic friction coefficient and static friction coefficient) The coefficient of friction was measured using a static and dynamic friction measuring instrument "TL201Ts" (product name, manufactured by Trinity Lab Co., Ltd.). The contactor was a urethane artificial finger, the load was 30 gf, the scanning distance was 40 mm, the scanning speed was 10 mm / sec, the coating substrate was artificial leather Sapplar (manufactured by Idemitsu Technofine Co., Ltd.), and the coating amount of particles in each example was 0.03 μL / mm2 in terms of bulk volume per unit area. 2 The coefficient of friction was measured as follows: The average value of the obtained coefficients of friction in the range of 300 msec to 4,000 msec was taken as the coefficient of kinetic friction, and the standard deviation within that range was taken as the standard deviation of the coefficient of kinetic friction. The static friction coefficient was determined from the maximum value in the range of 0 msec to 300 msec.

[0098] (Haze) The haze was measured using a haze meter "NDH-7000" (manufactured by Nippon Denshoku Industries Co., Ltd.). 0.38 g of the simulated sebum solution 3 and 0.02 g of each example particle were weighed and mixed, and thoroughly dispersed using a Biomasher II (manufactured by Nippi Corporation). This dispersion was sandwiched between quartz plates, taking care to avoid the inclusion of air bubbles, to prepare a measurement sample. A 30 μm-thick mending tape (manufactured by 3M) was used as a spacer.

[0099] (PSF half width) The PSF half-width was measured using the following procedure. The sample used for the haze measurement described above was placed on a glass plate, and a digital camera "STYLUS TG-4" (trade name, manufactured by Olympus Corporation) was placed 3.0 cm from the surface of the sample. An ISO resolution test chart No. 2 was placed 1.0 cm from the back of the sample as a background, and an image of the background was taken through the sample. This image was subjected to blind deconvolution using image analysis software "AutoQuantX3" (trade name, manufactured by Media Cybernetics) to obtain a PSF (point spread function) image. A line profile was obtained at a 45-degree angle passing through the center of the obtained PSF image, and its half-width was taken as the PSF half-width.

[0100] (sensory test) 1. Evaluation of smoothness In the sensory test, the smooth feeling was measured using the following procedure. An appropriate amount of particles (half of a microspatula) was applied to the inside of the upper arm, and the feel was checked with the fingertips. The degree of smooth feeling of the applied area was evaluated using the following four-point scale. Of the following evaluations, A and B are acceptable, and C and D are unacceptable. [Evaluation criteria] A: Highly smooth feeling B: Smooth feeling C: Low smoothness D: Not smooth

[0101] 2. Evaluation of smoothness In the sensory test, smoothness was measured using the following procedure. An appropriate amount of particles (half of a microspatula) was applied to the inside of the upper arm, and the feel was checked with the fingertip. The degree of smoothness of the applied area was evaluated using the following four-point scale. Of the following evaluations, A and B are acceptable, and C and D are unacceptable. [Evaluation criteria] A: High smoothness B: Smoothness C: Low smoothness D: Not smooth

[0102] (Example 1) Spherical porous silica particles "H-52" (AGC Si-Tech Co., Ltd., circularity 0.958, average particle diameter (volume basis, same below) 5.0 μm, specific surface area 652 m 2 30.0 g of calcium hydroxide (1.59 mL / g, pore volume 1.59 mL / g, average pore diameter 9.8 nm, oil absorption 324 mL / 100 g) was weighed. Next, 8.9 g of calcium hydroxide (Kanto Chemical Co., Ltd.) and 200 g of water were mixed to prepare a first solution. These were placed in a 300 mL glass beaker (Ca / Si (molar ratio) = 0.24) and reacted at room temperature for 7 hours while stirring at 250 rpm using an overhead stirrer. The mixture was then filtered using quantitative analysis filter paper type 5A (Advantec Corporation), washed with 600 mL of water, and substituted with 200 mL of isopropyl alcohol (Kanto Chemical Co., Ltd.). The resulting wet cake was dried at 70°C for 6 hours and then at 180°C for 12 hours to obtain 36.2 g of calcium-immobilized porous silica particles.

[0103] The entire amount of calcium-immobilized porous silica particles was stirred using a LAB.MIXER (Hanil Electric), and 39.9 mL of an aqueous solution (second solution) of phosphoric acid (Kanto Chemical Co., Ltd.) previously prepared to a concentration of 17.5 g / 100 mL was added. The addition was performed using a spray nozzle over a 2-minute period. The mixture was then filtered using quantitative analysis filter paper type 5A (Advantec), washed with 1,300 mL of water, and substituted with 200 mL of isopropyl alcohol (Kanto Chemical Co., Ltd.). The resulting wet cake was dried at 70°C for 6 hours and then at 180°C for 12 hours to yield 36.3 g of hydroxyapatite-supported porous silica particles.

[0104] Surface SEM images, cross-sectional SEM images, and cross-sectional EDX images of the obtained hydroxyapatite-supported porous silica particles were taken. The results are shown in Figures 1 to 3. Figure 1(a) is a surface SEM image of a hydroxyapatite-supported porous silica particle, Figure 1(b) is a cross-sectional SEM image of the same, Figure 2(a) is a cross-sectional SEM image of the particle subjected to EDX imaging, Figure 2(b) is a cross-sectional EDX image of silica (Si), Figure 3(a) is a cross-sectional EDX image of calcium (Ca), and Figure 3(b) is a cross-sectional EDX image of phosphorus (P). Figures 1(a) and 1(b) show that the hydroxyapatite-loaded porous silica particles are nearly spherical. Figure 2(a) shows that the hydroxyapatite-loaded porous silica particles were analyzed appropriately by EDX, Figure 2(b) shows that the particles have a porous silica skeletal structure, Figure 3(a) shows that calcium (Ca) is uniformly distributed within the particles, and Figure 3(b) shows that phosphorus (P) is uniformly distributed within the particles. Figures 2 and 3 show that hydroxyapatite is also uniformly distributed within the particles.

[0105] (Example 2) 28.2 g of hydroxyapatite-supporting porous silica particles were obtained in the same manner as in Example 1, except that 3.0 g of calcium hydroxide was used and the Ca / Si (molar ratio) was set to 0.08.

[0106] (Example 3) 55.1 g of hydroxyapatite-supporting porous silica particles were obtained in the same manner as in Example 1, except that 23.7 g of calcium hydroxide was used and the Ca / Si (molar ratio) was set to 0.64.

[0107] (Example 4) Spherical porous silica particles "H-52" (AGC Si-Tech Co., Ltd., circularity 0.958, average particle diameter 5.0 μm, specific surface area 652 m 2 50.0 g of calcium chloride (calcium chloride hydrate, 1.59 mL / g, pore volume 1.59 mL / g, average pore diameter 9.8 nm, oil absorption 324 mL / 100 g) was stirred using a LAB.MIXER (manufactured by HANIL ELECTRIC Co., Ltd.), and 62.2 mL of an aqueous solution (first solution) of calcium chloride (manufactured by Kanto Chemical Co., Inc.) previously prepared to a concentration of 56.3 g / 100 mL was added. The addition was performed using a spray nozzle over a 2-minute period. The mixture was then dried at 70°C for 6 hours to obtain calcium-immobilized porous silica particles.

[0108] The entire amount of calcium-immobilized porous silica particles was stirred using a LAB.MIXER. A mixture of 36.6 mL of a 90.0 g / 100 mL aqueous solution of dipotassium hydrogen phosphate (Kanto Chemical Co., Inc.) (second solution) and 56.7 mL of a 85.0 g / 100 mL aqueous solution of potassium hydroxide (Kanto Chemical Co., Inc.) (pH adjuster) was added. The mixture was added using a spray nozzle over a 2-minute period. The mixture was then filtered using quantitative analytical filter paper Type 5A (Advantec Corporation), washed with 2,200 mL of water, and purged with 350 mL of isopropyl alcohol (Kanto Chemical Co., Inc.). The resulting wet cake was dried at 70°C for 6 hours and then at 180°C for 12 hours to yield 73.1 g of hydroxyapatite-supported porous silica particles.

[0109] (Example 5) Spherical porous silica particles "H-52" (AGC Si-Tech Co., Ltd., circularity 0.958, average particle diameter 5.0 μm, specific surface area 652 m 2100 g of sucrose (1.59 mL / g, pore volume 1.59 mL / g, average pore diameter 9.8 nm, oil absorption 324 mL / 100 g) was weighed out. Next, 84.5 g of calcium hydroxide (manufactured by Kanto Chemical Co., Inc.) and 1,447 g of water were mixed to prepare a first solution. These were placed in a 3 L glass beaker (Ca / Si (molar ratio) = 0.69) and reacted at room temperature for 7 hours while stirring at 250 rpm using an overhead stirrer.

[0110] Next, 183 mL of an aqueous solution (second solution) of phosphoric acid (manufactured by Kanto Chemical Co., Inc.) previously prepared to a concentration of 29.6 g / 100 mL was added. The addition took 22 minutes using a roller pump. After the addition was completed, mixing was continued for 10 minutes, yielding 1,842 g of a slurry of hydroxyapatite-supported porous silica particles. The resulting slurry was quickly dried using a spray dryer, yielding 193 g of hydroxyapatite-supported porous silica particles.

[0111] (Example 6) Spherical porous silica particles "H-52" (AGC Si-Tech Co., Ltd., circularity 0.958, average particle diameter 5.0 μm, specific surface area 652 m 2 250 g of calcium hydroxide (Ca / Si (molar ratio) = 0.43) was weighed out. 126 g of calcium hydroxide (manufactured by Kanto Chemical Co., Ltd.) and 3443 g of water were mixed to prepare a first solution. The mixture was placed in a 10 L polyethylene container (Ca / Si (molar ratio) = 0.43) and reacted at 50°C for 2.5 hours while stirring at 250 rpm using an overhead stirrer.

[0112] Next, 294 mL of an aqueous solution (second solution) of phosphoric acid (manufactured by Kanto Chemical Co., Inc.) previously prepared to a concentration of 29.6 g / 100 mL was added. The addition took 14 minutes using a roller pump. After the addition was complete, mixing was continued for 10 minutes, yielding 4157 g of a slurry of hydroxyapatite-supported porous silica particles. The resulting slurry was quickly dried using a spray dryer, yielding 391 g of hydroxyapatite-supported porous silica particles.

[0113] (Example 7) Hydroxyapatite "Spherical HAP" (manufactured by Taihei Chemical Industry Co., Ltd., circularity 0.928, particle diameter 18.0 μm, specific surface area 39 m 2 / g, pore volume 0.32 mL / g, average pore diameter 33 nm, oil absorption 148 mL / 100 g) were used.

[0114] (Example 8) Spherical porous silica particles "H-52" (AGC Si-Tech Co., Ltd., circularity 0.958, average particle diameter 5.0 μm, specific surface area 652 m 2 / g, pore volume 1.59 mL / g, average pore diameter 9.8 nm, oil absorption 324 mL / 100 g), and hydroxyapatite "Spherical HAP" (manufactured by Taihei Chemical Industry Co., Ltd., circularity 0.928, particle diameter 18.0 μm, specific surface area 39 m 2 / g, pore volume 0.32 mL / g, average pore diameter 33 nm, oil absorption 148 mL / 100 g) were mixed in a mass ratio of spherical porous silica particles:hydroxyapatite = 60:40.

[0115] (Example 9) The same procedure as in Example 8 was carried out, except that the mixing ratio of the spherical porous silica particles to the hydroxyapatite was changed to spherical porous silica particles:hydroxyapatite=72:28.

[0116] (Example 10) The same procedures as in Example 8 were carried out except that the mixing ratio of the spherical porous silica particles to the hydroxyapatite was changed to spherical porous silica particles:hydroxyapatite=88:12.

[0117] (Example 11) Spherical porous silica particles "H-52" (AGC Si-Tech Co., Ltd., circularity 0.958, average particle diameter 5.0 μm, specific surface area 652 m 2 / g, pore volume 1.59 mL / g, average pore diameter 9.8 nm, oil absorption 324 mL / 100 g) was used.

[0118] (Example 12) Crushed porous silica particles (circularity 0.559, average particle diameter 42.9 μm, specific surface area 430 m 2 15.0 g of calcium hydroxide (Ca / Si (molar ratio) = 0.76 mL / g, average pore diameter = 7.1 nm, oil absorption = 149 mL / 100 g) was weighed out. Next, 4.4 g of calcium hydroxide (Kanto Chemical Co., Ltd.) and 100 g of water were mixed to prepare a first solution. These were placed in a 200 mL glass beaker (Ca / Si (molar ratio) = 0.24) and reacted at room temperature for 7 hours while stirring at 250 rpm using an overhead stirrer. The mixture was then filtered using quantitative analysis filter paper type 5A (Advantec Corporation), washed with 300 mL of water, and substituted with 100 mL of isopropyl alcohol (Kanto Chemical Co., Ltd.). The resulting wet cake was dried at 70°C for 6 hours and then at 180°C for 12 hours to obtain 19.3 g of calcium-immobilized crushed porous silica particles.

[0119] The entire amount of calcium-immobilized crushed porous silica particles was stirred using a LAB.MIXER (Hanil Electric), and 9.2 mL of an aqueous solution (second solution) of phosphoric acid (Kanto Chemical Co., Ltd.) previously prepared to a concentration of 37.3 g / 100 mL was added. The addition was performed using a spray nozzle over a period of 2 minutes. The mixture was then filtered using quantitative analysis filter paper type 5A (Advantec), washed with 650 mL of water, and substituted with 100 mL of isopropyl alcohol (Kanto Chemical Co., Ltd.). The resulting wet cake was dried at 70°C for 6 hours and then at 180°C for 12 hours to obtain 19.7 g of hydroxyapatite-supported porous silica particles.

[0120] (Example 13) Polyurethane particles "C-800 transparent" (manufactured by Negami Chemical Industrial Co., Ltd., circularity 0.964, particle diameter 8.1 μm, oil absorption 63 mL / 100 g) were used.

[0121] The circularity, hydroxyapatite loading amount, and average particle diameter (D 50 ), D 90 / D 10 , specific surface area, pore volume, average pore diameter, C HAp / CCeO2 The oil absorption, intra-particle uniformity of hydroxyapatite, inter-particle uniformity of hydroxyapatite particles, oleic acid adsorption, dynamic friction coefficient, standard deviation of dynamic friction coefficient, static friction coefficient, haze, and PSF half-width were measured, and a sensory test was conducted. The results are shown in Tables 2 and 3.

[0122] [Table 2]

[0123] [Table 3]

[0124] The results in Tables 2 and 3 indicate that Examples 1 to 6 have the same dynamic friction coefficient, static friction coefficient, and standard deviation of the dynamic friction coefficient as Example 13 (polyurethane particles), and thus have a smooth, slippery feel and a silky feel to the touch. Furthermore, the amount of oleic acid adsorbed is significantly greater than Examples 8 to 11 and 13, indicating that when used in cosmetics, for example, they can be expected to adsorb free fatty acids secreted from sebum and have an anti-acne effect (skin care properties). Furthermore, the haze and PSF half-width are greater than those of Example 11, which contains silica particles alone, indicating a high refractive index and excellent soft focus properties when used in cosmetics.

[0125] Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention. This application is based on a Japanese patent application (Patent Application No. 2020-073063) filed on April 15, 2020, the contents of which are incorporated herein by reference.

Claims

1. Hydroxyapatite-supported porous silica particles, in which hydroxyapatite is supported on the surfaces and inner surfaces of pores of spherical porous silica particles, and the circularity is 0.760 or more, Hydroxyapatite-supported porous silica particles, wherein when 0.5 g of the hydroxyapatite-supported porous silica particles are mixed with 5 g of a simulated sebum solution having an oleic acid concentration of 16% by mass, the oleic acid adsorption amount is 60 mg / g or more.

2. 2. The hydroxyapatite-supporting porous silica particles according to claim 1, wherein the amount of the hydroxyapatite supported in the hydroxyapatite-supporting porous silica particles is 0.1 to 80 mass %.

3. The maximum count number (C) in the range of 2θ=31.5 to 32.5° corresponding to the (211) plane of the hydroxyapatite in the XRD pattern of the hydroxyapatite-supporting porous silica particles ＨＡｐ ) and the maximum count number (C) within the range of 2θ=28.0 to 29.0° corresponding to the (111) plane of the cerium oxide in the XRD pattern of the cerium oxide separately measured as an external standard. ＣｅＯ２ ) and the ratio (C ＨＡｐ / C ＣｅＯ２ 3. The hydroxyapatite-supporting porous silica particles according to claim 1, wherein the value of (a) is 1.0 or less.

4. The hydroxyapatite-supporting porous silica particles according to any one of claims 1 to 3, wherein, in an image of a cross section of the hydroxyapatite-supporting porous silica particle observed by SEM-EDX, when the maximum diameter in a specific direction in the cross section is divided into three equal parts in the radial direction into first to third parts, point analysis is performed at three points arbitrarily selected from within a circle whose diameter is the diameter length of the second part located in the center, and at three points arbitrarily selected from within a circle whose diameter is the diameter length of either the first or third part, and the following conditions (1) to (3) are satisfied: (1) The average intra-particle coefficient of variation of the calcium peak signal intensity relative to the silicon peak signal intensity is 0 to 50%. (2) The average intra-particle coefficient of variation of the phosphorus peak signal intensity relative to the silicon peak signal intensity is 0 to 50%. (3) The average intra-particle coefficient of variation of the calcium peak signal intensity relative to the phosphorus peak signal intensity is 0 to 50%.

5. The hydroxyapatite-supported porous silica particles have an average particle diameter (D ５０ 5. The hydroxyapatite-supporting porous silica particles according to claim 1, wherein the average particle diameter is 1 to 500 μm.

6. 6. The hydroxyapatite-supporting porous silica particles according to claim 1, wherein the pore volume is 0.05 to 2.50 mL / g.

7. A method for producing hydroxyapatite-supported porous silica particles according to any one of claims 1 to 6, comprising the steps of: A method for producing hydroxyapatite-supporting porous silica particles, comprising contacting spherical porous silica particles having a circularity of 0.560 or more with a calcium source and a phosphorus source to produce hydroxyapatite.

8. bringing the spherical porous silica particles into contact with a first solution containing the calcium source, thereby fixing calcium on the surfaces and inner pore surfaces of the spherical porous silica particles; and 8. The method for producing hydroxyapatite-supporting porous silica particles according to claim 7, comprising contacting the spherical porous silica particles to which the calcium has been fixed with a second solution containing the phosphorus source, and reacting the calcium with the phosphorus to produce hydroxyapatite.

9. A skin composition, an oral composition, an adsorbent composition or a pharmaceutical composition, which comprises the hydroxyapatite-supported porous silica particles according to any one of claims 1 to 6.

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