Glass powder for cosmetic preparations, and cosmetic preparation

Abstract

A glass powder for cosmetic preparations, which contains amorphous glass particles that have an average circularity of 0.75 or more and contain SiO2 and at least one metal oxide M that is selected from the group consisting of B2O3, Al2O3, CaO, MgO, K2O, and Na2O, wherein: the total content of SiO2 and the metal oxide M is 95.0% by mass or more and the content of Al2O3 is 5.0% by mass or less. This glass powder for cosmetic preparations has an angle of repose of 35.0-50.0° and an angle of fall of 35.0-50.0°.

Description

Glass powder for cosmetics and cosmetics

[0001] The present disclosure relates to a glass powder for cosmetics and a cosmetic.

[0002] Cosmetics contain extremely fine resin particles (microplastics) such as PMMA (methyl methacrylate) particles, nylon particles, silicone particles, and polyurethane particles to adjust the feel and compatibility with the skin. Because microplastics are so small, they are difficult to remove at sewage treatment plants, and there are concerns that they may flow into rivers, oceans, ponds, and other areas, potentially affecting the marine ecosystem. Furthermore, microplastics may accumulate in seafood, which could potentially affect the human body. Therefore, there is a need to develop materials that are more environmentally and health-friendly as an alternative to resin particles used in cosmetics.

[0003] In Patent Document 1, SiO ２ 70 to 98% by weight, B ２ O ３ Patent Document 2 describes a silica powder for cosmetics, which is made of amorphous silica particles, the silica particles having an average circularity of 0.75 or more, and which satisfies at least one of the following conditions: (1) a degree of aggregation of 60% or more, (2) the difference between the angle of repose and the angle of collapse of 15 degrees or less, and (3) a degree of dispersion of 50% or less.

[0004] Japanese Patent Application Laid-Open No. 10-324539 International Publication No. 2023-243573

[0005] Glass particles are not microplastics and are a material that is gentler on the environment and the human body, but glass powder, which is an aggregate of glass particles, has a wide particle size distribution due to the manufacturing process, and tends to have a rough texture. When glass powder is blended into cosmetics, there are cases where a soft, spreadable, moist feel is required.

[0006] An object of one embodiment of the present disclosure is to provide a glass powder that can impart a soft, spreadable, and moist feel when blended into a cosmetic.An object of another embodiment of the present disclosure is to provide a cosmetic containing the glass powder.

[0007] The means for solving the above problems include the following aspects: <1> An average circularity of 0.75 or more, B ２ O ３ , Al ２ O ３ , CaO, MgO, K ２ O and Na ２ at least one metal oxide M selected from the group consisting of SiO ２ and SiO ２ and the metal oxide M has a total content of 95.0 mass% or more, and ２ O ３ <2> A glass powder for cosmetics, comprising amorphous glass particles having a content of B of 5.0 mass % or less, and having an angle of repose and an angle of collapse of 35.0 to 50.0°. ２ O ３ <3> The glass powder according to <1>, comprising: ２ O ３ <4> The glass powder according to <1> or <2>, wherein the content of the amorphous glass particles is 0.1 to 20.0 mass % based on the total amount of the amorphous glass particles. ２ <5> The glass powder according to any one of <1> to <3>, wherein the amorphous glass particles have a specific surface area of ​​0.1 m / g or less. ２ <6> The glass powder according to any one of <1> to <4>, wherein the amorphous glass particles have a 50% particle diameter (D ５０ ) is 0.5 to 100 μm, and the amorphous glass particles have a 90% particle diameter (D ９０ ) 10% particle diameter (D １０ ) to the ratio (D ９０ / D １０<7> The glass powder according to any one of <1> to <5>, wherein the 90% particle diameter (D ) in a cumulative particle size distribution based on volume is 1.0 to 5.0. ９０ <8> The glass powder according to any one of <1> to <6>, wherein the 10% particle diameter (D ) in a cumulative particle size distribution based on volume is 1.0 to 100 μm. １０ <9> The glass powder according to any one of <1> to <7>, wherein the amorphous glass particles are spherical porous silica particles and B ２ O ３ , Al ２ O ３ , CaO, MgO, K ２ O and Na ２ <1> The glass powder according to any one of <1> to <8>, which is a sintered body with at least one metal oxide M selected from the group consisting of O. <10> The glass powder according to any one of <1> to <9>, which has a degree of aggregation of 60.0% or more. <11> The glass powder according to any one of <1> to <10>, which has a stress relaxation rate of 18% or less when a load of 50 N is applied. <12> The glass powder according to any one of <1> to <11>, which has a shear adhesion of 2.0 kPa or more when a load of 50 N is applied. <13> The glass powder according to any one of <1> to <12>, which has a difference angle of 0 to 2.0°. <14> A cosmetic comprising the glass powder according to any one of <1> to <13>. <15> The cosmetic according to <14>, which is a makeup base, foundation, cosmetic cream, sunscreen, lotion, emulsion, serum, pack, face wash, eye color, lipstick, lip balm, deodorant, antiperspirant, or water-based gel.

[0008] According to one embodiment of the present disclosure, there is provided a glass powder that can impart a soft, spreadable, and moist feel when blended into a cosmetic. According to another embodiment of the present disclosure, there is provided a cosmetic comprising the glass powder.

[0009] Hereinafter, embodiments of the present disclosure will be described in detail. However, the embodiments of the present disclosure are not limited to the following embodiments. In the following embodiments, components (including element steps, etc.) are not essential unless otherwise specified. The same applies to numerical values ​​and their ranges, and do not limit the embodiments of the present disclosure.

[0010] In the present disclosure, numerical ranges indicated using "to" include the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In numerical ranges described in stages in the present disclosure, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another staged numerical range. In the present disclosure, each component may contain multiple corresponding substances. When multiple substances corresponding to each component are present in the composition, the content or amount of each component means the total content or amount of the multiple substances present in the composition, unless otherwise specified.

[0011] The glass powder for cosmetics according to the present disclosure (hereinafter also referred to as "the present glass powder") has an average circularity of 0.75 or more, and B ２ O ３ , Al ２ O ３ , CaO, MgO, K ２ O and Na ２ at least one metal oxide M selected from the group consisting of SiO ２ and SiO ２ and metal oxide M, the total content of which is 95.0 mass% or more, and ２ O ３ The glass particle contains amorphous glass particles (hereinafter also referred to as "the glass particles") having a content of 5.0 mass % or less, and has an angle of repose and an angle of collapse of 35.0 to 50.0°. In the present disclosure, the term "particles" is used to mean individual particles or the average particle in an aggregate thereof, and the term "powder" is used to mean the state of an aggregate of particles.

[0012] The present glass powder is used in cosmetics. That is, the present glass powder is for use in cosmetics. By blending the present glass powder in cosmetics described below, a soft, spreadable, moist feeling can be obtained.

[0013] Ordinary glass fillers and silica fillers have many hydroxyl groups remaining on their surfaces, which hydrogen bond to cancel out electrostatic interactions, resulting in a smooth, dry feel. On the other hand, materials with few hydroxyl groups, such as microplastic beads, have a strong electrostatic cohesion between particles due to their electrostatic charge, resulting in a soft, moist feel. This glass powder contains glass particles containing metal oxide M, which results in high hydroxyl group acidity and strong electrostatic interactions between particles, despite being an aggregate of inorganic particles, resulting in a soft, stretchy, moist feel.

[0014] Incidentally, Patent Documents 1 and 2 do not mention that when the angle of repose and the angle of collapse are both 35.0° to 50.0°, the texture is excellent.

[0015] The present glass particles are amorphous. By using amorphous glass particles, a glass powder suitable for cosmetics can be provided. In this disclosure, "amorphous" means that no diffraction peaks indicating crystallinity are observed by powder X-ray diffraction.

[0016] The present glass particles have an average circularity of 0.75 or more. When the average circularity is 0.75 or more, the particle shape becomes close to a sphere. Therefore, cosmetics containing the present glass powder can be easily spread on the skin when applied. The average circularity is preferably 0.80 or more, more preferably 0.85 or more, even more preferably 0.90 or more, and particularly preferably 0.95 or more. The upper limit of the average circularity is 1. Specific examples of the average circularity include 0.75 to 1.

[0017] The circularity can be calculated by determining the area and perimeter of particles from images obtained by a particle image analyzer (e.g., Morphologi 4 manufactured by Malvern Instruments) using image analysis software attached to the device, and then applying the results to the following formula: Average circularity is the average value calculated for 20 particles. Circularity = perimeter of circles with equal projected area / perimeter of particle The perimeter of circles with equal projected area is calculated by observing a particle from directly above, determining the area of ​​the shadow of the particle projected onto a flat surface below, and calculating a circle equal to this area, and the length of the outline of this circle is used. The perimeter of a particle is the length of the outline of the shadow of the particle projected onto a flat surface below when observed from directly above. In the present disclosure, "average circularity of amorphous glass particles" refers to the average circularity calculated for 20 amorphous glass particles randomly selected from the glass powder.

[0018] The glass particles are SiO ２ And B ２ O ３ , Al ２ O ３ , CaO, MgO, K ２ O and Na ２ and at least one metal oxide M selected from the group consisting of O.

[0019] The glass particles are SiO ２ In addition, it contains metal oxide M, so SiO ２ Compared to silica powder, which is composed solely of glass, glass powder has more silanol groups on the surface, which strengthens the electrostatic bonding force, improving the soft and moist feel of the glass powder.

[0020] SiO ２ The total content of SiO and metal oxide M is 95.0 mass % or more based on the total amount of the glass particles. ２ Since the total content of the glass powder and the metal oxide M is 95.0% by mass or more, the particles have a uniform composition, and aggregation of the glass powder due to the presence of non-uniform portions during blending is unlikely to occur. The total content is preferably 95.0% by mass or more, more preferably 98.0% by mass or more, and even more preferably 99.0% by mass or more. The total content may be 100% by mass.

[0021] SiO ２The content of is preferably 80.0 to 99.9 mass %, more preferably 85.0 to 99.0 mass %, based on the total amount of the glass particles.

[0022] The content of the metal oxide M is preferably 0.1 to 20.0 mass %, more preferably 1.0 to 15.0 mass %, and most preferably 1.0 to 5.0 mass %, based on the total amount of the glass particles, from the viewpoint of obtaining a softer and more moist feel.

[0023] Al ２ O ３ The content of Al is 5.0 mass % or less based on the total amount of the glass particles. ２ O ３ Since the content of Al is 5.0% by mass or less, the portion of the active aluminosilicate structure that is likely to cause aggregation in the particles is reduced, and the dispersibility is excellent when blended into cosmetics. ２ O ３ The content of Al is preferably 3.0 mass % or less, more preferably 1.0 mass % or less, and even more preferably 0.5 mass % or less. ２ O ３ It is particularly preferable that the composition is substantially free of Al. "Substantially free" means that the content of the target component is less than 0.1% by mass. ２ O ３ The content may be 0% by mass.

[0024] The glass particles are B ２ O ３ It is preferable that the composition contains ２ O ３ The content of B is preferably 0.1 to 20.0 mass % based on the total amount of the glass particles. ２ O ３ When the content of B is 0.1% by mass or more, the number of silanol groups on the surface of the glass powder is sufficiently increased, and the soft and moist feeling due to electrostatic attraction is enhanced. ２ O ３ When the content of B is 20.0% by mass or less, the circularity can be maintained high, and the creaking sensation that occurs when rubbed strongly can be suppressed. ２ O ３The content of B is more preferably 0.2% by mass or more, further preferably 0.5% by mass or more, particularly preferably 0.8% by mass or more, extremely preferably 1.5% by mass or more, and most preferably 2.0% by mass or more. ２ O ３ The content is more preferably 18.0% by mass or less, even more preferably 13.0% by mass or less, particularly preferably 10.0% by mass or less, extremely preferably 5.0% by mass or less, more extremely preferably 3.0% by mass or less, and most preferably 2.5% by mass or less.

[0025] The glass particles are SiO ２ and other components other than the metal oxide M may be contained within a range that does not impair the object of the present disclosure. Specific examples of other components include PbO, P ２ O ３ , Sb ２ O ５ , Li ２ O, ZrO ２ , Fe ２ O ３ , CuO, Sb ２ O ３ , SnO ２ , MnO, MnO ２ , CeO ２ , TiO ２ , SrO, MoO ３ , W.O. ３ Examples of oxides that are commonly used in glass include:

[0026] The content of other components is 15.0% by mass or less, preferably 10.0% by mass or less, more preferably 5.0% by mass or less, and most preferably 3.0% by mass or less, based on the total amount of the glass particles.

[0027] Specifically, the glass particles include spherical porous silica particles and B ２ O ３ , Al ２ O ３ , CaO, MgO, K ２ O and Na ２ It is preferable that the calcined body is a calcined body with at least one metal oxide M selected from the group consisting of O. The calcination method will be described in detail later.

[0028] The glass particles have a cumulative particle size distribution based on volume of 10% from the small particle size side (D １０ ) is preferably 0.3 to 100 μm. １０ If the particle size is 0.3 μm or more, secondary aggregation of the glass particles can be suppressed, and good dispersion in the cosmetic material can be easily obtained. １０ is more preferably 0.5 μm or more, further preferably 0.9 μm or more, and particularly preferably 1.9 μm or more. １０ If the diameter is 100 μm or less, the glass particles are not too large, and the feeling of use when blended into cosmetics is improved. １０ is more preferably 30.0 μm or less, even more preferably 20.0 μm or less, particularly preferably 10.0 μm or less, extremely preferably 5.2 μm or less, and most preferably 2.4 μm or less.

[0029] The glass particles have a 50% particle diameter (D ５０ ) is preferably 0.5 to 100 μm. ５０ If the particle size is 0.5 μm or more, secondary aggregation of the glass particles can be suppressed, and good dispersion in the cosmetic material can be easily obtained. ５０ is more preferably 0.7 μm or more, even more preferably 0.9 μm or more, particularly preferably 1.0 μm or more, and most preferably 2.9 μm or more. ５０ If the diameter is 100 μm or less, the glass particles are not too large, and the feeling of use when blended into cosmetics is improved. ５０ is more preferably 50.0 μm or less, even more preferably 20.0 μm or less, particularly preferably 9.9 μm or less, extremely preferably 6.5 μm or less, and most preferably 3.8 μm or less.

[0030] The glass particles have a cumulative 90% particle diameter (D ９０ ) is preferably 1.0 to 100 μm. ９０ If the particle size is 1.0 μm or more, secondary aggregation of the glass particles can be suppressed, and good dispersion in the cosmetic material can be easily obtained. ９０is more preferably 2.0 μm or more, even more preferably 3.0 μm or more, and particularly preferably 5.6 μm or more. ９０ If the diameter is 100 μm or less, the glass particles are not too large, and the feeling of use when blended into cosmetics is improved. ９０ is more preferably 50.0 μm or less, even more preferably 30 μm or less, particularly preferably 20.0 μm or less, extremely preferably 16.1 μm or less, even more extremely preferably 9.8 μm or less, and most preferably 6.3 μm or less.

[0031] The glass particles have a 90% particle diameter (D ９０ ) 10% particle diameter (D １０ ) to the ratio (D ９０ / D １０ ) is preferably 1.0 to 5.0. ９０ / D １０ When the D is within the above range, the amount of coarse particles is reduced and the increase in the specific surface area due to fine particles is suppressed, so that a good feel is obtained when applied to the skin. ９０ / D １０ is more preferably 4.5 or less, even more preferably 3.8 or less, and particularly preferably 3.0 or less. ９０ / D １０ is more preferably 1.5 or more, even more preferably 2.0 or more, particularly preferably 2.5 or more, and most preferably 2.9 or more.

[0032] In particular, the glass particles have a 50% particle diameter (D ５０ ) is 0.5 to 100 μm, and the ratio (D ９０ / D １０ ) is preferably 1.0 to 5.0.

[0033] 10% particle size (D １０ ), 50% particle diameter (D ５０ ), and 90% particle size (D ９０ ) can be calculated using a particle size distribution measuring device using an electrical detection method (for example, Multisizer 4e manufactured by Beckman Coulter, Inc.).

[0034] The present glass powder has an angle of repose and an angle of collapse of 35.0 to 50.0°. Having both an angle of repose and an angle of collapse of 35.0 to 50.0° results in low fluidity, and when incorporated into cosmetics, it can produce a soft, spreadable, and moist feel similar to that of microplastic beads. Furthermore, having both an angle of repose and an angle of collapse of 35.0 to 50.0° also tends to reduce the difference angle. Furthermore, a difference angle of 8.0° or less results in a powder with strong electrostatic loose cohesion between particles, resulting in a strong spreadable, moist feel. By including the present glass particles, the present glass powder tends to have its angle of repose, angle of collapse, and difference angle each converge within the ranges. The difference angle refers to the angle between the angle of repose and the angle of collapse.

[0035] From the above viewpoints, the angle of repose is preferably 38.0 to 50.0°, more preferably 40.0 to 50.0°, even more preferably 41.0 to 50.0°, and most preferably 41.0 to 47.0°. From the above viewpoints, the angle of collapse is preferably 38.0 to 50.0°, more preferably 39.0 to 46.0°, and most preferably 41.0 to 47.0°.

[0036] The angle of repose is the angle between the horizontal plane and the slope of the cone-shaped peak formed when powder is dropped from a funnel of a certain height and remains stable without spontaneously collapsing.

[0037] The collapse angle is the angle between the generatrix of the cone and the horizontal plane when a specified impact is applied to the cone-shaped peak formed in the measurement of the angle of repose, causing part of the cone to collapse.

[0038] The angle of repose and the angle of collapse can be measured using a powder tester (e.g., Hosokawa Micron Corporation, Model PT-X). Specifically, a measuring platform with a diameter of 80 mm is placed horizontally, and a 1.7 mm mesh sieve and funnel (e.g., stainless steel, upper opening diameter 70 mm, lower opening diameter 7 mm, inclination angle 63 degrees, height from the measuring platform to the lower opening of the funnel 7.5 cm) are placed above the measuring platform. 250 mL of powder is gently placed into the sieve, and the sieve is vibrated with an amplitude of 1.5 mm, causing the powder to fall through the sieve and funnel onto the measuring platform, depositing it in a conical shape. The conical shape is then photographed from the side, and the angle between the generatrix of the cone and the horizontal plane is measured once to determine the angle of repose. The collapse angle is determined by applying the same impact three times to the powder for which the angle of repose has been measured using an automatic shocker attached to the device, then photographing the conical shape of the sample from directly beside it, and measuring the angle between the generatrix of the cone and the horizontal plane once.

[0039] A method for adjusting both the angle of repose and the angle of collapse to 35.0 to 50.0° includes, for example, heat-treating and pulverizing a spherical glass composition produced by a wet method or a granulation method to obtain a uniform glass powder, which is then classified as necessary to appropriately adjust the particle size distribution. By using the above method, the glass powder can be adjusted to have a soft, stretchy, and moist feel similar to that of microplastic beads.

[0040] Since the present glass powder has an angle of repose and an angle of collapse both of 35.0 to 50.0°, the difference angle (i.e., the difference between the angle of repose and the angle of collapse) is 15.0° or less. From the viewpoint of providing a stronger spreadable and moist feel, the difference angle is preferably 8.0° or less, more preferably 5.0° or less, even more preferably 2.0° or less, particularly preferably 1.9° or less, extremely preferably 1.1° or less, and most preferably 0.6° or less. The difference angle may be 0°. That is, the difference angle is preferably 0 to 8.0°, more preferably 0 to 5.0°, even more preferably 0 to 2.0°, particularly preferably 0 to 1.9°, extremely preferably 0 to 1.1°, and most preferably 0 to 0.6°.

[0041] The degree of agglomeration of the present glass powder is preferably 60.0% or more, more preferably 70.0% or more, even more preferably 80.0% or more, particularly preferably 90.0% or more, extremely preferably 95.0% or more, even more extremely preferably 98.0% or more, and most preferably 99.0% or more.

[0042] When the degree of cohesion is 60.0% or more, the interaction between the glass particles is strong and the adhesion between the particles is improved, so that when the glass powder is spread on the skin, a soft, spreadable, and moist feeling is obtained. By containing the present glass particles, the degree of cohesion of the present glass powder tends to converge to this range.

[0043] The degree of agglomeration can be measured using a powder tester (for example, model PT-X manufactured by Hosokawa Micron Corporation). Specifically, a sieve with a mesh size of 250 μm, a sieve with a mesh size of 150 μm, and a sieve with a mesh size of 75 μm are set on the vibration table of the powder tester in this order from top to bottom, and 2.0 g of powder is placed on the upper sieve (with a mesh size of 250 μm). The sieve is vibrated at a vibration amplitude of 1.0 mm for 90 seconds, the mass of powder remaining on each sieve is measured, and the degree of agglomeration is calculated according to the following formula: degree of agglomeration (%)={(A+B×3 / 5+C×1 / 5) / 2}×100, where A: mass of powder on the upper sieve, B: mass of powder on the middle sieve, and C: mass of powder on the lower sieve.

[0044] The degree of dispersion of the present glass powder is preferably 50.0% or less, more preferably 20.0% or less, even more preferably 15.0% or less, and particularly preferably 10.0% or less. The degree of dispersion is preferably 0% or more, more preferably 1.0% or more, and even more preferably 2.0% or more. The degree of dispersion is, for example, 0 to 50.0%. When the degree of dispersion is 50.0% or less, the electrostatic interaction between the particles is high after the glass powder is moved and stopped, resulting in a stretchy feel. By including the present glass particles, the degree of dispersion of the present glass powder tends to converge within this range.

[0045] The degree of dispersion (%) is the ratio of the mass of the powder before it falls onto a measurement table to the mass of the powder that does not fall onto the measurement table but is scattered. The degree of dispersion (%) can be measured using a powder tester (for example, model PT-X manufactured by Hosokawa Micron Corporation). Specifically, 10 g of powder is placed on the top of the dispersibility measurement unit of the powder tester, and the powder is dropped onto a watch glass with a diameter of 100 mm placed 60 cm below the dispersibility measurement unit. The mass of the powder that has accumulated on the watch glass is weighed, and the degree of dispersion is calculated using the following formula: degree of dispersion (%) = {(mass (g) of powder before falling - mass (g) of powder accumulated on the watch glass) / mass (g) of powder before falling} × 100

[0046] The present glass powder preferably has a shear adhesion of 2.0 kPa or more when a load of 50 N is applied. Shear adhesion indicates the adhesion between glass particles; the greater the shear adhesion, the stronger the adhesion, and the soft, moist feeling that results when the glass powder is incorporated into a cosmetic. A shear adhesion of 2.0 kPa or more results in a stronger sense of soft, moist feeling. The shear adhesion is more preferably 2.2 kPa or more, even more preferably 2.4 kPa or more, and particularly preferably 2.6 kPa or more. The shear adhesion is preferably 5.0 kPa or less, more preferably 4.5 kPa or less, and even more preferably 4.0 kPa or less. In other words, the shear adhesion is preferably 2.0 to 5.0 kPa. By including the present glass particles, the shear adhesion of the present glass powder is more likely to converge within this range.

[0047] The shear adhesion is measured using a powder bed shear force measuring device (e.g., Nano Seeds, model NS-S500) in accordance with JIS Z 8835:2016 under the following conditions, and a failure envelope (YL) is obtained by plotting the shear stress (y-axis) corresponding to each normal stress (x-axis). The shear adhesion is obtained from the intersection of YL and the y-axis. Conditions: cell inner diameter 43 mm, indentation gap 0.2 mm, indentation speed 0.2 mm / sec, stress relaxation time 100 sec, shear speed 10 μm / sec, normal load 50 N.

[0048] The present glass powder preferably has a stress relaxation rate of 18% or less when a load of 50 N is applied. When the stress relaxation rate is 18% or less, a soft and moist feel can be sufficiently obtained. The stress relaxation rate of the glass powder is more preferably 17% or less, even more preferably 16% or less, and particularly preferably 15% or less. Furthermore, the lower limit of the stress relaxation rate is not particularly limited, but is preferably 1% or more, more preferably 3% or more, even more preferably 5% or more, and most preferably 8% or more. In other words, the stress relaxation rate is preferably 1 to 18%. When the present glass powder contains the present glass particles, the stress relaxation rate tends to converge to this range.

[0049] The stress relaxation rate is the degree of rearrangement of glass particles when glass powder is compacted under load. The smaller the stress relaxation rate, the greater the interaction between glass particles. This improves the adhesion between glass particles, resulting in a soft, moist feel.

[0050] The stress relaxation rate can be measured using a powder bed shear force measuring device (for example, Nano Seeds, model NS-S500). Specifically, assuming that the normal load applied to the powder bed is 50 N, the stress relaxation rate (%) relative to the normal stress at the start of shearing can be calculated using the following formula from the maximum normal load a on the top surface of the powder bed during pre-compaction and the normal load b on the top surface of the powder bed 100 seconds after stress relaxation: Stress relaxation rate (%) = (1 - b / a) x 100

[0051] The glass powder has a loose bulk density of 0.4 to 0.9 g / cm ３ It is preferable that the loose bulk density is 0.6 to 0.8 g / cm. The loose bulk density is the bulk density measured when the powder is gently packed into a container. The gently packed powder has many gaps between the particles. When the loose bulk density is within the above range, the interaction between the glass particles is strong, resulting in many gaps and a large rate of change with respect to load, making it easier to obtain a soft, stretchy, and moist feel. The loose bulk density is 0.6 to 0.8 g / cm. ３ More preferably, it is 0.7 to 0.8 g / cm ３ When the present glass powder contains the present glass particles, the loose bulk density thereof tends to converge within the above range.

[0052] The glass powder has a packed bulk density of 1.0 to 1.5 g / cm ３ The packed bulk density is the bulk density measured after filling a container gently with powder by applying a constant vibration to the container to fill the gaps between the particles and then refilling the container. If the packed bulk density is within the above range, it can be said that the particles are consolidated. The packed bulk density is 1.0 to 1.4 g / cm ３ More preferably, it is 1.0 to 1.2 g / cm ３ is more preferably 1.0 to 1.1 g / cm ３ When the present glass powder contains the present glass particles, the packed bulk density thereof tends to converge within the above range.

[0053] The loose bulk density and packed bulk density can be measured using a powder tester (e.g., Hosokawa Micron Corporation, Model PT-X). Specifically, glass powder is gently poured into a dedicated cup, and the cup is filled until the glass powder overflows from the mouth. The surface of the powder that overflowed from the dedicated cup is then leveled off with an attached blade, and the mass including the cup is measured. The mass of the glass powder is calculated by subtracting the pre-measured mass of the cup from this value, and the value obtained by dividing this value by the internal volume of the cup is defined as the loose bulk density. Next, a cap is placed on the dedicated cup, and the cup is placed in the tapping holder of the powder tester. The cup is then further filled with glass powder, and a cap cover is attached on top of the cap. This is then tapped 180 times. After tapping is completed, the cap and cap cover are removed, and the surface of the dedicated cup is leveled off with an attached blade, and the mass including the cup is measured. The mass of the glass powder is calculated by subtracting the pre-measured mass of the cup from this value, and the value obtained by dividing this value by the internal volume of the cup is defined as the packed bulk density.

[0054] The glass powder preferably has a degree of compression of 37.0% or more. If the degree of compression is 37.0% or more, the glass powder is compacted in accordance with the load when applied to the skin, resulting in a soft, moist feeling. The degree of compression is more preferably 38.0% or more, even more preferably 40.0% or more, and particularly preferably 42.0% or more. The degree of compression is preferably 70.0% or less, more preferably 65.0% or less, and even more preferably 60.0% or less. In other words, the degree of compression is preferably 37.0 to 70.0%. The degree of compression can be calculated using the loose bulk density and packed bulk density values ​​described above according to the following formula: Compressibility (%) = {(packed bulk density - loose bulk density) / packed bulk density} x 100

[0055] The glass powder containing the glass particles of the present invention tends to have a compaction degree that falls within the above range. The compaction degree is the rate of reduction in the volume of the powder when a predetermined load is applied to the powder from when no load is applied to the powder.

[0056] The glass particles have a specific surface area of ​​5.0 m2 as determined by the nitrogen adsorption method. ２ / g or less. ２ When the glass powder has a molecular weight of 1 / g or less, the number of silanol groups in the glass particles is reduced, improving adhesion between the glass particles, thereby improving the soft and moist feeling when the glass powder is blended into cosmetics.

[0057] The smaller the specific surface area, the better the soft and moist feeling that can be imparted. ２ / g, more preferably less than 4.0m ２ / g or less is more preferable, and 2.0m ２ / g or less is more preferable, and 1.2m ２ / g or less is particularly preferred, and 0.7m ２ The lower limit of the specific surface area is not particularly limited, but is preferably 0.1 m ２ / g or more. That is, the specific surface area is preferably 0.1 m ２ / g or more 5.0m ２ The specific surface area can be calculated using the BET theory after obtaining an adsorption isotherm by a nitrogen adsorption method.

[0058] The present glass powder can be produced using the present glass particles obtained by, for example, forming a spherical glass precursor and heat-treating the glass precursor. The glass precursor may be obtained by manufacturing or may be a commercially available product. Examples of methods for producing the glass precursor include a wet method and a granulation method.

[0059] The wet process refers to a method that involves using a liquid glass source and gelling it to obtain the raw material for spherical glass particles. Granulation is a method in which glass particles are molded into a spherical shape using a binder or other agent. Among these methods, the wet process, which can control the particle size distribution and produce spherical particles, can form spherical glass particles, eliminating the need for shaping the particles through grinding or other methods, resulting in particles with a small specific surface area. Furthermore, the wet process is less likely to produce particles significantly smaller than the average particle size, which tends to result in a small specific surface area after firing. Furthermore, the wet process can adjust the amount of impurity elements such as titanium by adjusting the impurities in the glass source, and can also achieve a state in which the aforementioned impurity elements are uniformly dispersed within the particles.

[0060] Examples of wet methods include spraying and emulsion gelation. The emulsion gelation method involves, for example, emulsifying a dispersed phase containing a glass precursor with a continuous phase, and then gelling the resulting emulsion to obtain a spherical glass precursor. A preferred emulsification method involves supplying a dispersed phase containing a glass precursor to a continuous phase through micropores or a porous membrane to produce an emulsion. This produces an emulsion with uniform droplet sizes, resulting in a glass powder composed of glass particles with uniform particle sizes. The particle size of the glass particles can be adjusted by adjusting the stirring speed during emulsification. Examples of such emulsification methods include a micromixer method and a membrane emulsification method. For example, the micromixer method is disclosed in International Publication No. 2013 / 062105.

[0061] The glass precursor obtained by the wet method is preferably porous. A porous glass precursor makes it easier to obtain glass particles with controlled shape and powder particle size distribution, compared to glass particles produced by firing a non-porous raw material that has been pulverized. Furthermore, when a porous glass precursor is heated, the primary particles of several nanometers to several tens of nanometers that constitute the internal pore structure melt, reducing the surface area and further filling the pores. It is also known that the presence of sodium lowers the melting point. Here, a porous glass precursor means that pores are evenly distributed in the glass precursor.

[0062] The pore volume of the glass precursor obtained by the wet method is preferably 0.05 to 2.2 mL / g. When the pore volume of the glass precursor is 0.05 mL / g or more, the glass particles shrink sufficiently during firing, thereby reducing the specific surface area. Furthermore, when the pore volume of the glass precursor is 2.2 mL / g or less, the bulk density of the pre-fired material is prevented from becoming too large, thereby improving productivity. The pore volume of the glass precursor is preferably 0.1 to 2.2 mL / g, more preferably 0.3 to 2.2 mL / g, even more preferably 0.3 to 1.8 mL / g, particularly preferably 0.6 to 1.8 mL / g, and most preferably 0.7 to 1.5 mL / g.

[0063] The pore volume can be measured by the same method as described above.

[0064] The ignition loss of a glass precursor obtained by a wet process is preferably 5.0 to 15.0% by mass. The ignition loss is the sum of water adhering to the glass precursor and water generated by condensation of silanol groups contained in the glass precursor. When the glass precursor has an appropriate number of silanol groups, condensation progresses during firing, making it easier for the silanol groups to be reduced. The reduction in silanol groups causes the glass particles to become electrically charged, increasing the interaction between the glass particles. If the ignition loss is too high, the yield during firing may decrease and productivity may deteriorate. Therefore, the ignition loss of the glass precursor is preferably 15.0% by mass or less, more preferably 13.0% by mass or less, and most preferably 12.0% by mass or less. If the ignition loss is too low, silanol groups are more likely to remain during firing. Therefore, the ignition loss of the glass precursor is preferably 5.0% by mass or more, more preferably 6.0% by mass or more, and most preferably 7.0% by mass or more. The loss on ignition is determined in accordance with JIS K 0067:1992 as the mass loss when 1 g of the glass precursor is heated and dried at 850° C. for 0.5 hours.

[0065] The average pore diameter of the glass precursor obtained by the wet method is preferably 1.0 to 50.0 nm. When the average pore diameter is 1.0 nm or more, the glass particles can be made uniformly non-porous all the way to the interior. When the average pore diameter is 50.0 nm or less, the glass particles can be densified (reduced specific surface area) by firing without leaving any pores, resulting in a soft, moist feel. The average pore diameter is more preferably 2.0 to 40.0 nm, even more preferably 3.0 to 30.0 nm, and particularly preferably 4.0 to 20.0 nm.

[0066] The average pore diameter can be determined by the BET method based on the nitrogen adsorption method using a specific surface area / pore distribution measuring device (for example, "BELSORP-mini II" manufactured by Microtrac-Bell, or "Tristar II" manufactured by Micromeritics).

[0067] The glass precursor obtained by the wet method preferably has a mass loss rate of 10% or less when dried at 230°C for 12 hours. If the mass loss rate is 10% or less, sintering of the particles is unlikely to occur when the glass precursor is fired in a state where the particles are in contact with each other, and spherical glass particles are likely to be obtained. The mass loss rate is more preferably 9% or less, even more preferably 8% or less, and particularly preferably 6% or less. Furthermore, since it is desirable that the mass does not change even after drying at 230°C for 12 hours, the lower limit is not particularly limited.

[0068] When the obtained glass precursor has a high water content and the mass loss rate when dried at 230° C. for 12 hours exceeds 10%, it is preferable to dry it until the mass loss rate is 10% or less. Examples of drying methods include a spray dryer, static drying in a dryer, and ventilation treatment with dry air.

[0069] The means for heat treatment of the glass precursor is not particularly limited, and examples thereof include heat treatment by standing, heat treatment in a rotary furnace, and heat treatment by spray combustion. For heat treatment by standing, a stationary electric furnace, a roller hearth kiln, a continuous furnace classified as a tunnel furnace, and the like can be used. For heat treatment in a rotary furnace, a horizontal rotary furnace (rotary kiln), a rotary tubular furnace, and the like can be used. Among these, from the viewpoint of uniformity of firing, it is preferable to perform heat treatment by a continuous furnace or a rotary furnace. Here, by adjusting the temperature during heat treatment, it is possible to adjust the degree of cohesion, angle of repose, angle of collapse, degree of dispersion, specific surface area, shear adhesion, stress relaxation rate, compressibility, coefficient of friction, and the like of the glass powder.

[0070] The heat treatment temperature is preferably 700° C. or higher, more preferably 800° C. or higher, even more preferably 900° C. or higher, and particularly preferably 1000° C. or higher. From the viewpoint of suppressing crystallization, the heat treatment temperature is preferably 1600° C. or lower, more preferably 1500° C. or lower, and even more preferably 1400° C. or lower. That is, the heat treatment temperature is preferably 700° C. to 1600° C.

[0071] The firing time may be adjusted as appropriate depending on the firing apparatus and firing time used, but is preferably 0.5 to 50 hours, more preferably 1 to 10 hours, for example.

[0072] The firing atmosphere may be either oxygen-containing or oxygen-free. When a glass precursor is obtained by a wet method, an organic substance such as an emulsifier is often used, and organic substances often remain in the glass precursor. When a glass precursor containing an organic substance is fired under conditions with little oxygen, the organic substance carbonizes, causing coloration. Therefore, when the glass precursor contains an organic substance, firing is preferably carried out in an oxygen-containing atmosphere, more preferably in the air atmosphere.

[0073] Furthermore, during firing, it is preferable to fire the glass precursor in a state where the particles are in contact with each other. Firing in a state where the particles are in contact with each other allows firing in a small volume, which reduces temperature and time variations during firing compared to, for example, firing the glass precursor dispersed in a gas, thereby obtaining glass particles of consistent quality. In the spray combustion method in which the glass precursor is dispersed in a gas, even when the raw material powder is blown in from the center of the flame, the temperature of the blown gas, the dispersion state of the raw material, temperature differences due to different parts passing through the flame, differences in the time it takes to pass through the flame, and the time it takes to cool due to the airflow (flow velocity) distribution within the device all lead to variations in firing conditions. Firing the glass precursor in a state where the particles are in contact with each other makes it possible to uniformize the firing conditions for each glass precursor and maintain consistent quality.

[0074] Glass particles may be weakly sintered together after firing, and in such cases, they may be crushed. Crushing is preferably carried out so that the average circularity of the particles does not fall below 0.75 in order to maintain the average circularity and specific surface area so as not to impair the effects of the present disclosure. It is also preferable that the specific surface area does not increase as a result of the crushing treatment. A significant increase in the specific surface area due to the crushing treatment means that some glass particles have been pulverized or that fine damage has occurred on the surface, resulting in the generation of fine powder. It is preferable to suppress the increase in the specific surface area so as not to reduce the soft and moist feeling when the glass powder is incorporated into cosmetics.

[0075] The crushing can be carried out using a crushing device such as a cyclone mill or a jet mill, and crushing can also be carried out using a vibrating sieve.

[0076] The glass particles obtained by firing may be surface-treated with a silane coupling agent, which reacts with silanol groups present on the surfaces of the glass particles constituting the glass powder, reducing the number of silanol groups on the surfaces and improving dispersibility in oil.

[0077] The conditions for the surface treatment are not particularly limited, and general surface treatment conditions may be used, and a wet treatment method or a dry treatment method may be used. From the viewpoint of performing a uniform treatment, the wet treatment method is preferred.

[0078] Examples of the silane coupling agent used in the surface treatment include aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, silane coupling agents, organosilazane compounds, etc. These may be used alone or in combination of two or more.

[0079] Specific examples of the surface treatment agent include aminosilane-based coupling agents such as aminopropyl methoxysilane, aminopropyl triethoxysilane, ureidopropyl triethoxysilane, N-phenylaminopropyl trimethoxysilane, and N-2(aminoethyl)aminopropyl trimethoxysilane; epoxysilane-based coupling agents such as glycidoxypropyl trimethoxysilane, glycidoxypropyl triethoxysilane, glycidoxypropyl methyldiethoxysilane, glycidyl butyl trimethoxysilane, and (3,4-epoxycyclohexyl)ethyl trimethoxysilane; mercaptosilane-based coupling agents such as mercaptopropyl trimethoxysilane and mercaptopropyl triethoxysilane; silane-based coupling agents such as methyltrimethoxysilane, vinyltrimethoxysilane, octadecyltrimethoxysilane, phenyltrimethoxysilane, metachloroxypropyl trimethoxysilane, imidazole silane, and triazine silane; and CF ３ (CF ２ ) ７ CH ２ CH ２ Si(OCH ３ ) ３ , C.F. ３ (CF２ ) ７ CH ２ CH ２ SiCS ３ 、CF ３ (CF ２ ) ７ CH ２ CH ２ Si (CH ３ )(OCH ３ ) ２ 、CF ３ (CF ２ ) ７ CH ２ CH ２ Si (CH ３ )C1 ２ 、CF ３ (CF ２ ) ５ CH ２ CH ２ SiCS ３ 、CF ３ (CF ２ ) ５ CH ２ CH ２ Si (OCH ３ ) ３ 、CF ３ CH ２ CH ２ SiCS ３ 、CF ３ CH ２ CH ２ Si (OCH ３ ) ３ 、C ８ F １７ SO ２ N (C ３ H ７ )CH ２ CH ２ CH ２ Si (OCH ３ ) ３ 、C ７ F １５ [NNHCH ２ CH ２ CH ２ Si (OCH ３ ) ３ 、C ８ F １７ CO ２ CH ２ CH ２ CH２ Si(OCH ３ ) ３ , C ８ F １７ -O-CF(CF ３ )CF ２ -O-C ３ H ６ SiCl ３ , C ３ F ７ -O-(CF(CF ３ )CF ２ -O) ２ -CF (CF ３ )CONH-(CH ２ ) ３ Si(OCH ３ ) ３ fluorine-containing silane coupling agents such as hexamethyldisilazane, hexaphenyldisilazane, trisilazane, cyclotrisilazane, 1,1,3,3,5,5-hexamethylcyclotrisilazane, and other organosilazane compounds.

[0080] When a silane coupling agent is used, the amount of the silane coupling agent to be used is preferably 0.01 parts by mass or more, more preferably 0.02 parts by mass or more, and even more preferably 0.10 parts by mass or more, per 100 parts by mass of the glass particles. The amount of the silane coupling agent to be used is preferably 5 parts by mass or less, more preferably 2 parts by mass or less, per 100 parts by mass of the glass particles.

[0081] Examples of methods for treating with a silane coupling agent include a dry method in which the silane coupling agent is sprayed onto glass particles, and a wet method in which the glass particles are dispersed in a solvent and then a silane coupling agent is added to cause a reaction.

[0082] The fact that the surface of the glass particles has been treated with a silane coupling agent can be confirmed by detecting a peak due to a substituent of the silane coupling agent by infrared spectroscopy (IR). The amount of the silane coupling agent attached can be measured by the carbon content.

[0083] The content of the present glass particles in the present glass powder can be adjusted as appropriate. The present glass powder may consist solely of the present glass particles, or may contain the present glass particles and second glass particles other than the present glass particles. By including the second glass particles, it is possible to adjust the feel to be similar to that of resin, i.e., a soft, stretchy, and moist feel. The shape of the second glass particles is preferably spherical, flaky, plate-like, balloon-like, or crushed, with spherical being more preferred.

[0084] The cosmetic of the present disclosure contains the glass powder. When blended into a cosmetic, the glass powder can impart a soft, spreadable, and moist feel, and therefore the cosmetic of the present disclosure exhibits a soft, spreadable, and moist feel.

[0085] The content of the present glass powder in the cosmetic can be adjusted as appropriate.

[0086] In addition to the glass powder, the cosmetic preparation of the present disclosure may contain other components that are commonly used in cosmetic preparations. Examples of such other components include water, oil components, water-miscible organic solvents, UV absorbers, antioxidants, preservatives / antibacterial agents, fragrances, surfactants, thickeners, inorganic powders, acids, alkalis, and sugars. The content of such other components can be adjusted appropriately depending on the intended use.

[0087] Furthermore, the cosmetic of the present disclosure may contain, in addition to the present glass powder, one or more second glass powders other than the present glass powder. By including a second glass powder other than the present glass powder, it is possible to adjust the feel of the cosmetic to be similar to that of resin, i.e., a soft, spreadable, and moist feel. The shape of the glass powder other than the present glass powder is preferably spherical, flaky, plate-like, balloon-like, or crushed, with spherical being more preferred.

[0088] The cosmetic preparation of the present disclosure can be in any suitable form depending on the formulation and purpose. The form of the cosmetic preparation is not particularly limited, and examples include powder, liquid, cream, gel, stick, and the like.

[0089] Examples of the cosmetic material of the present disclosure include a makeup base, foundation, cosmetic cream, sunscreen, lotion, emulsion, serum, pack, facial cleanser, eye color, lipstick, lip balm, deodorant, antiperspirant, and water-based gel.

[0090] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the following description, the same components are used. Examples 1 to 7 and 14 to 16 are working examples, and Examples 8 to 13 are comparative examples.

[0091] (Example 1) As a spherical glass precursor, silica powder (Sunsphere H-31, manufactured by AGC Si-Tech Co., Ltd., average particle size 3 μm, pore volume (PV) 1.00 g / mL, BET specific surface area 650 m) produced by a wet method was used. ２ / g, oil absorption 150 mL / 100 g) was used. 100 g of spherical silica precursor was dispersed in 1 L of 1 M hydrochloric acid. After solid-liquid separation, the resulting cake was washed with 10 L of distilled water and dried in vacuum at 200 °C to obtain washed silica powder. 100 g of the resulting washed silica powder was placed in a container. Furthermore, a solution of 2.0 g of boric acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) dissolved in 80 mL of water was added, and the mixture was mixed at 2000 rpm for 3 minutes using a planetary centrifugal mixer (ARE-310, manufactured by Thinky Corporation). The mixture was then dried in an oven at 200 °C for 4 hours, followed by air calcination at 1150 °C for 1 hour. The resulting powder was pulverized using a Wonder Crusher to obtain a glass powder consisting of 100 g of glass particles.

[0092] (Example 2) As a spherical glass precursor, silica particle powder (Sunsphere H-51, manufactured by AGC Si-Tech Co., Ltd., median diameter (D ５０ ) 5 μm, pore volume (PV) 0.8 g / mL, BET specific surface area 700 m ２ A glass powder composed of glass particles was obtained in the same manner as in Example 1, except that a glass powder having a glass absorption of 150 mL / 100 g was used.

[0093] (Example 3) As a spherical glass precursor, silica particle powder (Sunsphere L-71N, manufactured by AGC Si-Tech Co., Ltd., median diameter (D ５０) 7 μm, pore volume (PV) 0.7 g / mL, BET specific surface area 400 m ２ A glass powder composed of glass particles was obtained in the same manner as in Example 1, except that a glass powder having a glass absorption of 150 mL / 100 g was used.

[0094] (Example 4) As a spherical glass precursor, silica particle powder (Sunsphere H-121, manufactured by AGC Si-Tech Co., Ltd., median diameter (D ５０ ) 12 μm, pore volume (PV) 0.8 g / mL, BET specific surface area 720 m ２ A glass powder composed of glass particles was obtained in the same manner as in Example 1, except that a glass powder having a glass absorption of 150 mL / 100 g was used.

[0095] Example 5 A glass powder composed of glass particles was obtained in the same manner as in Example 1, except that the amount of boric acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was changed from 2.0 g to 0.2 g.

[0096] Example 6 A glass powder composed of glass particles was obtained in the same manner as in Example 1, except that the amount of boric acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was changed from 2.0 g to 13.0 g.

[0097] Example 7 A glass powder composed of glass particles was obtained in the same manner as in Example 1, except that the amount of boric acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was changed from 2.0 g to 18.0 g.

[0098] Example 8 Silica powder was obtained in the same manner as in Example 1 of WO 2023-242573.

[0099] Example 9 A commercially available spherical glass powder having an average particle size of 3.5 μm was used.

[0100] Example 10 A commercially available spherical glass powder having an average particle size of 1.8 μm was used.

[0101] Example 11 Spherical glass powder EMB-10 manufactured by Potters Ballotini was used.

[0102] Example 12 A commercially available spherical glass powder having an average particle size of 21.1 μm was used.

[0103] Example 13 Spherical glass powder, Sphericel 110P8 manufactured by Potters Ballotini Co., Ltd., was used.

[0104] Example 14 A glass powder composed of glass particles was obtained in the same manner as in Example 1, except that 2.0 g of boric acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was changed to 8.0 g of sodium carbonate (manufactured by Kanto Chemical Co., Ltd.) and the mixture was fired in air at 1000°C for 1 hour.

[0105] Example 15 A glass powder composed of glass particles was obtained in the same manner as in Example 1, except that 2.0 g of boric acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was changed to 12.5 g of calcium lactate n-hydrate (manufactured by Kanto Chemical Co., Inc.).

[0106] Example 16 A glass powder composed of glass particles was obtained in the same manner as in Example 1, except that 2.0 g of boric acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was changed to 14.5 g of magnesium sulfate heptahydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.).

[0107] Powder X-ray diffraction measurements were carried out on the glass powders of Examples 1 to 7 and Examples 14 to 16, and the results showed that all were composed of amorphous glass particles. The glass particles contained in the glass powders of Examples 1 to 16 were all composed of SiO ２ and metal oxide M(B ２ O ３ , Al ２ O ３ , CaO, MgO, K ２ O and Na ２ O) was 95.0 mass % or more.

[0108] The glass powders or silica powders of Examples 1 to 16 were subjected to the following measurements. The results are shown in Tables 1 and 2.

[0109] <Average Circularity of Particles> Photographs of the powder were taken using a scanning electron microscope (JCM-7000, manufactured by JEOL Ltd.), and the area and perimeter of the particles were determined using image analysis software (image analysis software attached to the particle image analyzer "Morphologi4" manufactured by Malvern Instruments). The average circularity was calculated using the following formula: Circularity = perimeter of a circle with the same projected area / perimeter of a particle Circumference of a circle with the same projected area: When a particle is observed from directly above, the area of ​​the shadow of the particle projected onto a flat surface below is determined, and a circle equivalent to this area is calculated and the length of the outline of that circle Particle perimeter: When a particle is observed from directly above, the length of the outline of the shadow of the particle projected onto a flat surface below is calculated.

[0110] <10% particle size of powder (D １０ ), 50% particle diameter (D ５０ ), 90% particle size (D ９０ ), 90% particle size (D ９０ ) 10% particle diameter (D １０ ) to the ratio (D ９０ / D １０ Distilled water was added to the powder to prepare a 0.05% by mass slurry, which was then treated in an ultrasonic cleaner at a frequency of 45 kHz for 2 minutes. The 50% particle diameter (D) in the cumulative particle size distribution on a volume basis was measured using an electrical detection particle size distribution measuring device (Multisizer 4e, manufactured by Beckman Coulter, Inc.). ５０ ) was calculated (settings: aperture diameter 50 μm, effective N number 50,000, current 800 μA, gain 4, stirring speed 15, electrolyte isoton). In addition, using the same procedure as above, the 90% particle diameter (D ９０ ) and 10% particle size (D １０ ) and D ９０ D １０ Ratio to (D ９０ / D １０ ) was calculated.

[0111] <Specific Surface Area of ​​Powder> The powder was dried under reduced pressure at 230°C to completely remove moisture, and used as a sample. The specific surface area of ​​this sample was determined by the multipoint BET method using nitrogen gas with an automatic specific surface area and pore distribution measuring device "Tristar II" manufactured by Micromeritics.

[0112] <Powder Shear Adhesion> Measurements were performed using a powder bed shear force measuring device (NS-S500, manufactured by Nano Seeds Co., Ltd.) in accordance with JIS Z 8835:2016 under the following conditions, and a fracture envelope (YL) was obtained by plotting the shear stress (y-axis) corresponding to each normal stress (x-axis). The shear adhesion was calculated from the intersection of YL and the y-axis. Conditions: cell inner diameter 43 mm, indentation gap 0.2 mm, indentation speed 0.2 mm / sec, stress relaxation time 100 sec, shear speed 10 μm / sec, normal load 50 N.

[0113] <Stress Relaxation Rate of Powder> Using a powder bed shear force measuring device (NS-S500 model, manufactured by Nano Seeds Co., Ltd.), a vertical load of 50 N was applied to the powder bed, and the stress relaxation rate (%) relative to the vertical stress at the start of shearing was calculated using the following formula, from the maximum vertical load a on the top surface of the powder layer during pre-compaction and the vertical load b on the top surface of the powder layer 100 seconds after stress relaxation: Stress relaxation rate (%) = (1 - b / a) × 100

[0114] <Loose bulk density, packed bulk density, compressibility, cohesion, angle of repose, angle of collapse, angle of difference, and dispersibility of powder> Measurements were carried out using a powder tester (model number: PT-X) manufactured by Hosokawa Micron Corporation.

[0115] (Loose bulk density) The powder was gently poured into a dedicated cup with an internal volume of 100 mL, and the cup was filled until the powder overflowed. The powder overflowing from the cup was leveled off with an attached blade, and the mass including the mass of the cup was measured. The mass of the powder was calculated by subtracting the mass of the cup measured previously from this value, and the mass was divided by the internal volume of the cup to calculate the loose bulk density.

[0116] (Packed Bulk Density) After measuring the loose bulk density, the dedicated cup was capped and placed in the tapping holder of the powder tester. The cup was then further filled with powder and a cap cover was attached to the cap. Then, the cup was tapped 180 times. After the tapping was completed, the cap and cap cover were removed, the surface of the cup was leveled with an attached blade, and the mass including the cup was measured. The mass of the glass powder was calculated by subtracting the mass of the cup measured previously from this value, and the mass was divided by the internal volume of the cup to calculate the packed bulk density.

[0117] (Compressibility) The compressibility was measured from the values ​​of the packed bulk density and loose bulk density according to the following formula: Compressibility (%) = {(packed bulk density - loose bulk density) / packed bulk density} x 100

[0118] (Agglomeration Degree) A sieve with a mesh size of 250 μm, a sieve with a mesh size of 150 μm, and a sieve with a mesh size of 75 μm were set on the vibration table of a powder tester in this order from top to bottom, and 2.0 g of powder was placed on the upper sieve (250 μm mesh), and the sieve was vibrated at a vibration amplitude of 1.0 mm for 90 seconds. The mass of the powder remaining on each sieve was measured, and the agglomeration degree was calculated according to the following formula: Agglomeration Degree (%) = {(A + B × 3 / 5 + C × 1 / 5) / 2} × 100, where A: mass of powder on the upper sieve, B: mass of powder on the middle sieve, and C: mass of powder on the lower sieve.

[0119] (Angle of repose) A measuring table with a diameter of 80 mm was placed horizontally, and a 1.7 mm mesh sieve and funnel (made of stainless steel, upper opening diameter 70 mm, lower opening diameter 7 mm, inclination angle 63 degrees, height from the measuring table to the lower opening of the funnel 7.5 cm) were placed above the measuring table. 250 mL of powder was gently placed into the sieve, and the sieve was vibrated at an amplitude of 1.5 mm, causing the powder to fall through the sieve and funnel onto the measuring table, depositing it in a conical shape. The conical shape was then photographed from the side, and the angle between the generatrix of the cone and the horizontal plane was measured. The number average value of one measurement was taken as the angle of repose.

[0120] (Collapse angle) The powder for which the angle of repose was measured was subjected to the same impact three times using an automatic shocker attached to the device, and then the conical shape of the sample was photographed from the side, and the angle between the generatrix of the cone and the horizontal plane was measured. The number average value of one measurement was taken as the collapse angle.

[0121] (Difference Angle) Based on the angle of repose and the angle of collapse, the difference between the angle of repose and the angle of collapse was calculated. If the difference angle is 8.0 or less, it can be said that the product has a strong, spreadable, moist feel.

[0122] (Dispersibility) 10 g of powder was placed on the top of the dispersibility measurement unit, and the powder was dropped onto a watch glass with a diameter of 100 mm placed 60 cm below the dispersibility measurement unit. The dispersibility (%) was calculated from the mass of the powder piled up on the watch glass using the following formula: Dispersibility (%) = {(mass (g) of powder before dropping - mass (g) of powder piled up on the watch glass) / mass (g) of powder before dropping} × 100

[0123] <Soft and moist feeling> The soft and moist feeling of the powders of Examples 1 to 13 was evaluated by five panelists according to the following procedure. The evaluation results are shown in Tables 1 and 2. (Procedure) An appropriate amount of powder (about one spoonful with a microspatula) was taken on the back of the hand or the inside of the forearm and rubbed in with the fingers. At this time, the "soft and moist feeling" was evaluated according to the following criteria. The average score for each item was calculated and the feel was evaluated. [Soft and moist feeling] 5 points: soft and moist. 1 point: dry.

[0124]

[0125]

[0126] As shown in Tables 1 and 2, the glass powders of Examples 1 to 7 and 14 to 16 exhibited a soft, moist feel. Furthermore, it was found that these glass powders had a small difference angle and a strong, stretchy, moist feel. From the above, it was found that the glass powder of the present disclosure has a soft, stretchy, moist feel.

[0127] The disclosure of Japanese Patent Application No. 2024-146898, filed on August 28, 2024, is incorporated herein by reference in its entirety. In addition, all documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually indicated to be incorporated by reference.

Claims

1. The average circularity is 0.75 or more, and B ２ O ３ , Al ２ O ３ , CaO, MgO, K ２ O and Na ２ at least one metal oxide M selected from the group consisting of SiO ２ and the SiO ２ and the metal oxide M has a total content of 95.0 mass% or more, and ２ O ３ % or less by mass, and the angle of repose and the angle of collapse are both 35.0 to 50.0°.

2. The amorphous glass particles are B ２ O ３ The glass powder of claim 1 , comprising:

3. B above ２ O ３ The glass powder according to claim 1, wherein the content of the amorphous glass particles is 0.1 to 20.0 mass % based on the total amount of the amorphous glass particles.

4. The amorphous glass particles have a specific surface area of ​​5.0 m ２ The glass powder according to claim 1, wherein the glass powder has a viscosity of 1000 MPa or less.

5. The amorphous glass particles have a specific surface area of ​​0.1 m ２ The glass powder according to claim 1, wherein the glass powder has a molecular weight of 1 / g or more.

6. The amorphous glass particles have a 50% particle diameter (D ５０ ) is 0.5 to 100 μm, and the amorphous glass particles have a 90% particle diameter (D ９０ ) 10% particle diameter (D １０ ) to the ratio (D ９０ / D １０ 2. The glass powder according to claim 1, wherein the saturation coefficient (S) of the glass powder is 1.0 to 5.

0.

7. The amorphous glass particles have a 90% particle diameter (D ９０ 2. The glass powder according to claim 1, wherein the average particle size of the glass powder is 1.0 to 100 μm.

8. The amorphous glass particles have a 10% particle size (D １０ 2. The glass powder according to claim 1, wherein the particle size is 0.3 to 100 μm.

9. The amorphous glass particles are spherical porous silica particles and B ２ O ３ , Al ２ O ３ , CaO, MgO, K ２ O and Na ２ 2. The glass powder according to claim 1, which is a sintered body with at least one metal oxide M selected from the group consisting of O.

10. The glass powder according to claim 1, having a degree of agglomeration of 60.0% or more.

11. The glass powder according to claim 1, which has a stress relaxation rate of 18% or less when a load of 50 N is applied.

12. The glass powder according to claim 1, which has a shear adhesion strength of 2.0 kPa or more when a load of 50 N is applied.

13. The glass powder according to claim 1, wherein the difference angle is 0 to 2.0 degrees.

14. A cosmetic comprising the glass powder according to any one of claims 1 to 13.

15. The cosmetic according to claim 14, which is a makeup base, foundation, cosmetic cream, sunscreen, lotion, emulsion, serum, pack, facial cleanser, eye color, lipstick, lip balm, deodorant, antiperspirant, or water-based gel.

Images