SPF booster and cosmetic

Abstract

Provided is a new SPF booster exhibiting an excellent SPF-improving effect. The SPF booster has an IR / IE ratio of 1.00-2.80, wherein the IR is a light intensity at a light receiving angle of 45° at the time when the normal line to a surface coated with the SPF booster is taken as 0° and when the surface is irradiated with total light from an incidence angle of -45° and the IE is a maximum light intensity at light receiving angles in a range of -42° to -40.5° at the time when the normal line to the surface coated with the SPF booster is taken as 0° and when the surface is irradiated with total light from an incidence angle of -45°. The SPF booster is a powder of crystalline titanium phosphate having a primary particle diameter D50 of 0.1-10 μm, the D50 being a particle diameter in a volume-based cumulative particle diameter distribution of the primary particles at which the cumulative frequency from the small-particle-diameter side is 50%.

Description

SPF enhancers and cosmetics

[0001] The present invention relates to an SPF enhancer and a cosmetic composition.

[0002] To protect against ultraviolet rays, ultraviolet absorbers and ultraviolet scattering agents are used. SPF enhancers are known that do not have sufficient ultraviolet blocking effect alone but can improve the ultraviolet blocking effect when used in combination with ultraviolet absorbers and / or ultraviolet scattering agents. SPF (Sun Protection Factor) indicates the ability to protect against UV-B.

[0003] Introducing a New Raw Material: SPF Booster "Rohmsphere™ Powder SPF Booster," Fragrance Journal, November 2006, pp. 120-121, discloses that the combined use of hollow spherical particles made of a (styrene / alkyl acrylate) copolymer and an ultraviolet absorber provides an SFP-enhancing effect. International Publication No. 2012 / 161084 discloses that the combined use of polyamide porous microparticles having a spherulite structure, a number-average particle size of 1 to 30 μm, and a particle size distribution of 1 to 2.5, and an organic ultraviolet spherical absorber, or the combined use of an inorganic ultraviolet screener in addition to these, provides an SPF-enhancing effect. Japanese Patent Application Laid-Open No. 2022-156914 discloses that the SPF of cosmetics can be improved by adding a composite powder consisting of a spherical powder coated with an oil agent and a plate-like powder attached thereto.

[0004] However, from the viewpoint of reducing the impact on the marine environment, there is a growing demand for alternatives to microplastic bead-like SPF enhancers such as those described in the new SPF booster "Rohmsphere™ Powder SPF Booster," Fragrance Journal, Inc., November 2006, pp. 120-121, and International Publication No. 2012 / 161084. The composite powder described in JP 2022-156914 A has the problem that it may not provide sufficient SPF enhancement.

[0005] Furthermore, when used for the purpose of preventing sunburn, if the amount of ultraviolet scattering agent used is increased to improve the ultraviolet blocking effect, the skin may become too white when applied. For this reason, there is an increasing demand for an improved ultraviolet blocking effect while reducing the amount of ultraviolet absorber and / or ultraviolet scattering agent used.

[0006] Therefore, an object of the present invention is to provide a new SPF enhancer that exhibits an excellent SPF improving effect.

[0007] One aspect of the present invention for achieving the above object is to measure the maximum light intensity I at a light receiving angle in the range of -42° to -40.5° when all light rays are irradiated from an incident angle of -45°, with the normal to the surface to which the SPF improver is applied being taken as 0°. Ｅ The normal to the surface to which the SPF improver is applied is taken as 0°, and the light intensity I at a receiving angle of 45° when all light rays are irradiated from an incident angle of -45° is Ｒ I is the ratio of Ｒ / I Ｅ is 1.00 or more and 2.80 or less.

[0008] Another aspect of the present invention for achieving the above object relates to an SPF enhancer that is a crystalline titanium phosphate powder having a primary particle diameter D50 of 0.1 μm or more and 10 μm or less, at which the cumulative frequency from the small particle size side in the volume-based cumulative particle diameter distribution of primary particles is 50%.

[0009] FIG. 1 shows the I of SPF enhancers. Ｒ and I Ｅ Fig. 2 is a graph showing the results of XRD measurement of SPF enhancer 3 according to one embodiment and the results of XRD measurement of standard card: 01-079-7347. Fig. 3 is an SEM image of SPF enhancer 3 according to one embodiment.

[0010] While the present invention will be described below with reference to exemplary embodiments, it should be understood that the present invention is not limited to the following exemplary embodiments and can be modified in various ways within the scope of the claims. The exemplary embodiments described in this specification can be combined in any manner to form other exemplary embodiments.

[0011] In this specification, unless otherwise specified, operations and measurements of physical properties are carried out at room temperature (20° C. or higher and 25° C. or lower).

[0012] In this specification, "X to Y" is used to mean that the numerical values ​​(X and Y) written before and after it are included as the lower limit and upper limit, and means "at least X but not more than Y."

[0013] As used herein, "A and / or B" means that each of A and B is included, as well as any combination thereof.

[0014] In one aspect of the present invention, the maximum light intensity I at a light receiving angle in the range of -42° to -40.5° when all light rays are irradiated from an incident angle of -45°, with the normal to the surface to which the SPF improver is applied being taken as 0°. Ｅ The normal to the surface to which the SPF improver is applied is taken as 0°, and the light intensity I at a receiving angle of 45° when all light rays are irradiated from an incident angle of -45° is Ｒ I is the ratio of Ｒ / I Ｅ According to this aspect, it is possible to provide a new SPF improver that exhibits an excellent SPF improving effect.

[0015] Another aspect of the present invention relates to an SPF enhancer that is a crystalline titanium phosphate powder having a primary particle size D50 of 0.1 μm or more and 10 μm or less, at which the cumulative frequency of the smaller particle size in the volume-based cumulative particle size distribution of the primary particles is 50%. According to this aspect, it is possible to provide a new SPF enhancer that exhibits excellent SPF enhancement effects.

[0016] These aspects will be described in detail below.

[0017] In this specification, the SPF enhancer according to the present invention is also simply referred to as “SPF enhancer.” In this specification, the cosmetic according to the present invention is also simply referred to as “cosmetic.”

[0018] In this specification, the SPF improving effect refers to the effect of being able to increase the SPF of a target composition by including an ultraviolet absorber and / or an ultraviolet scattering agent in the target composition.

[0019] By including an SPF enhancer in the target composition together with an ultraviolet absorber and / or an ultraviolet scattering agent, the SPF of the target composition can be increased without increasing the amount of the ultraviolet absorber and / or the ultraviolet scattering agent.

[0020] In this specification, the normal to the surface to which the SPF improver is applied is taken as 0°, and the maximum light intensity at a light receiving angle in the range of −42° to −40.5° when all light rays are irradiated from an incident angle of −45° is defined as I Ｅ The normal to the surface to which the SPF improver is applied is set to 0°, and the light intensity at a receiving angle of 45° when all light rays are irradiated from an incident angle of -45° is defined as I Ｒ Let's say. Ｅ The larger the value, the stronger the retroreflection. Ｒ The larger the value, the stronger the specular reflection. Ｅ I against Ｒ I is the ratio of Ｒ / I Ｅ It is believed that the closer to 1, the more uniform the scattering in multiple directions. Conventional SPF improvers tend to have large specular reflection or retrograde reflection, whereas the I of the SPF improver according to one embodiment of the present invention is Ｒ / I Ｅ It is believed that by setting the SPF improver to a predetermined range, the frequency with which light scattered by the SPF improver is incident on the ultraviolet absorber and / or ultraviolet scattering agent increases. However, this mechanism is based on speculation, and the accuracy of this speculation does not affect the technical scope of the present invention.

[0021] SPF enhancer I Ｒ / I Ｅ There are no particular limitations on the I of the SPF improver. Ｒ / I Ｅ is preferably 0.80 or more, more preferably 0.90 or more, and even more preferably 1.00 or more. Ｒ / I Ｅ is preferably 2.80 or less, more preferably 1.50 or less, and even more preferably 1.45 or less. Ｒ / I ＥThe closer to 1, the greater the SPF improving effect. Ｒ / I Ｅ The I of the SPF improver may be, for example, 1.10 or more, 1.20 or more, 1.30 or more, or 1.40 or more. Ｒ / I Ｅ Specific examples of the range are 0.80 or more and 2.80 or less, 0.80 or more and 1.50 or less, 0.80 or more and 1.45 or less, 0.90 or more and 2.80 or less, 0.90 or more and 1.50 or less, 0.90 or more and 1.45 or less, 1.00 or more and 2.80 or less, 1.00 or more and 1.50 or less, 1.00 or more and 1.45 or less, 1.10 or more and 2.80 or less, 1.10 or more and 1. 1.50 or less, 1.10 or more and 1.45 or less, 1.20 or more and 2.80 or less, 1.20 or more and 1.50 or less, 1.20 or more and 1.45 or less, 1.30 or more and 2.80 or less, 1.30 or more and 1.50 or less, 1.30 or more and 1.45 or less, 1.40 or more and 2.80 or less, 1.40 or more and 1.50 or less, 1.40 or more and 1.45 or less, etc., but the I of the SPF improver is Ｒ / I Ｅ The range is not limited to these.

[0022] SPF enhancer I Ｒ and I Ｅ The SPF can be evaluated by the following method. First, an SPF improver is uniformly applied to a protein leather supplier manufactured by Ideatex Japan Co., Ltd., which is an artificial leather, to obtain a measurement sample. Next, a three-dimensional goniophotometer GP-200 manufactured by Murakami Color Research Laboratory Co., Ltd. is used to measure the measurement sample at an incident angle of -45° and an acceptance angle of -90 to 90°. The I of the SPF improver is Ｒ and I Ｅ An explanatory diagram for explaining the relationship between each angle when the normal to the surface to which the SPF enhancer is applied is set to 0° in the evaluation of (1) is shown in Fig. 1. In Fig. 1, 1 represents the surface to which the SPF enhancer is applied, and 2 represents incident light.

[0023] In this specification, the haze for light with a wavelength of 310 nm represents a value calculated by the following formula.

[0024] Haze for light with a wavelength of 310 nm (unit: %) = (diffuse transmittance for light with a wavelength of 310 nm / total light transmittance for light with a wavelength of 310 nm) × 100 The units for the diffuse transmittance for light with a wavelength of 310 nm and the total light transmittance for light with a wavelength of 310 nm are %.

[0025] The haze of the SPF improver for light with a wavelength of 310 nm is not particularly limited. The haze of the SPF improver for light with a wavelength of 310 nm is preferably 75.0% or more, more preferably 80.0% or more, even more preferably 85.0% or more, particularly preferably 90.0% or more, and even more particularly preferably 95.0% or more. When the haze of the SPF improver for light with a wavelength of 310 nm is equal to or greater than these lower limits, the SPF improving effect is further enhanced.

[0026] Therefore, specific examples of the haze range of an SPF improver for light with a wavelength of 310 nm include 75.0% or more and 100.0% or less, 80.0% or more and 100.0% or less, 85.0% or more and 100.0% or less, 90.0% or more and 100.0% or less, and 95.0% or more and 100.0% or less, but the haze range of an SPF improver for light with a wavelength of 310 nm is not limited to these.

[0027] The haze of an SPF improver can be evaluated by the following method. First, a slurry is obtained containing 9% by mass of the SPF improver relative to the total mass of the slurry, 70% by mass of an acrylic silicone film-forming agent (KP-545, manufactured by Shin-Etsu Chemical Co., Ltd.) relative to the total mass of the slurry, and 21% by mass of a volatile silicone oil (KF96L-2CS, manufactured by Shin-Etsu Chemical Co., Ltd.) relative to the total mass of the slurry. The obtained slurry is then applied using a bar coater with a wet film thickness of 25 μm and dried at room temperature (room temperature) to obtain a coating film. The content of the SPF improver relative to the total mass of the obtained coating film is 30% by mass. The obtained coating film is then measured using a spectrophotometer consisting of a UV-2450 ultraviolet-visible spectrophotometer manufactured by Shimadzu Corporation equipped with an ISR-2200 integrating sphere manufactured by Shimadzu Corporation.

[0028] Titanium phosphate has the chemical formula Ti(HPO ４ ) ２ ・nH ２O (n is an integer). Titanium phosphate is preferably a compound represented by the chemical formula Ti(HPO ４ ) ２ ・nH ２ O (0≦n≦1), and more preferably a compound represented by the chemical formula Ti(HPO ４ ) ２ ・H ２ It is a compound represented by O.

[0029] The SPF enhancer is not particularly limited, but is preferably a powder. In this specification, the term "powder" refers to an aggregate of a plurality of particles.

[0030] The SPF enhancer is preferably a crystalline titanium phosphate powder. When the SPF enhancer is a crystalline titanium phosphate powder, the SPF improving effect is particularly enhanced. Whether the SPF enhancer is a crystalline titanium phosphate powder can be confirmed by powder X-ray diffraction. A powder in which peaks characteristic of titanium phosphate crystals are confirmed by powder X-ray diffraction is a powder composed mostly or entirely of crystalline titanium phosphate. In this specification, a powder in which peaks characteristic of titanium phosphate crystals are confirmed by powder X-ray diffraction is referred to as a "crystalline titanium phosphate powder." It is preferable that no peaks other than those confirmed for titanium phosphate crystals are confirmed in the crystalline titanium phosphate powder.

[0031] The shape of the particles contained in the SPF enhancer is not particularly limited. The SPF enhancer preferably contains plate-like particles. When the SPF enhancer is a crystalline titanium phosphate powder, the shape of the particles contained in the crystalline titanium phosphate powder is not particularly limited. The SPF enhancer is preferably a crystalline titanium phosphate powder, and the crystalline titanium phosphate powder preferably contains plate-like particles. The plate-like particles are not particularly limited, but examples thereof include discoid particles and polygonal plate-like particles. The discoid particles may have a plate-like surface shape that is either perfectly circular or not. The discoid particles having a plate-like surface shape that is not perfectly circular are not particularly limited, but examples thereof include oval particles and constricted gourd-shaped particles. The polygonal plate-like particles are not particularly limited, but examples thereof include triangular plate-like particles, quadrangular plate-like particles, pentagonal plate-like particles, hexagonal plate-like particles, and other polygonal plate-like particles.

[0032] The shape of the particles contained in the SPF enhancer and the shape of the particles contained in the crystalline titanium phosphate powder can each be confirmed by observation with a scanning electron microscope (SEM).

[0033] In this specification, the "primary particle diameter D50 at which the cumulative frequency from the small particle diameter side in the volume-based cumulative particle diameter distribution of primary particles becomes 50%" is also referred to as the "volume-based cumulative 50% primary particle diameter."

[0034] The volume-based cumulative 50% primary particle diameter of the SPF improver is not particularly limited. The volume-based cumulative 50% primary particle diameter of the SPF improver is preferably 0.1 μm or more, more preferably 0.2 μm or more, even more preferably 0.5 μm or more, and particularly preferably 1 μm or more. The volume-based cumulative 50% primary particle diameter of the SPF improver is preferably 10 μm or less, more preferably 4 μm or less, even more preferably 2 μm or less, and particularly preferably 1.5 μm or less. When the volume-based cumulative 50% primary particle diameter of the SPF improver is within these ranges, the SPF improving effect is further enhanced. Specific examples of the range of the volume-based cumulative 50% primary particle diameter of the SPF enhancer include 0.1 μm or more and 10 μm or less, 0.1 μm or more and 4 μm or less, 0.2 μm or more and 4 μm or less, 0.5 μm or more and 2 μm or less, and 1 μm or more and 1.5 μm or less, but the range of the volume-based cumulative 50% primary particle diameter of the SPF enhancer is not limited to these.

[0035] When the SPF improver is a crystalline titanium phosphate powder, the volume-based cumulative 50% primary particle size of the crystalline titanium phosphate powder is not particularly limited. The volume-based cumulative 50% primary particle size of the crystalline titanium phosphate powder is preferably 0.1 μm or more, more preferably 0.2 μm or more, even more preferably 0.5 μm or more, and particularly preferably 1 μm or more. The volume-based cumulative 50% primary particle size of the crystalline titanium phosphate powder is preferably 10 μm or less, more preferably 4 μm or less, even more preferably 2 μm or less, and particularly preferably 1.5 μm or less. When the volume-based cumulative 50% primary particle size of the crystalline titanium phosphate powder is within these ranges, the SPF improving effect is further enhanced. Specific examples of the range of the volume-based cumulative 50% primary particle size of the crystalline titanium phosphate powder include 0.1 μm or more and 10 μm or less, 0.1 μm or more and 4 μm or less, 0.2 μm or more and 4 μm or less, 0.5 μm or more and 2 μm or less, and 1 μm or more and 1.5 μm or less, but the range of the volume-based cumulative 50% primary particle size of the crystalline titanium phosphate powder is not limited to these.

[0036] The volume-based cumulative 50% primary particle diameter of the SPF enhancer and the volume-based cumulative 50% primary particle diameter of the crystalline titanium phosphate powder can be evaluated using a scanning electron microscope (SEM) and image analysis software "Mac-View ver. 4" manufactured by Mountec Co., Ltd. 100 to 200 primary particles are measured, and the longest diameter of each primary particle is determined. The obtained value is the individual primary particle diameter. The longest diameter of the primary particle is determined by the length of the longest side of a rectangle (rectangle or square) circumscribing the primary particle. Here, the rectangle with the longest side length is determined by rotating the selected primary particle 360° and calculating the rectangle circumscribing the primary particle at each rotation angle, and the rectangle with the longest side (longest side) is used. Then, using each primary particle diameter, a value at which the cumulative frequency from the small particle size side in the volume-based cumulative particle size distribution of the primary particles becomes 50% is calculated, and the calculated value is designated as the primary particle diameter D50 (volume-based cumulative 50% primary particle diameter) at which the cumulative frequency from the small particle size side in the volume-based cumulative particle size distribution of the primary particles becomes 50%.

[0037] In the measurement and calculation of the volume-based cumulative 50% primary particle diameter, when the primary particles are plate-like particles, the longest diameter of the primary particles represents the longest diameter of the plate surface of the plate-like particle. The longest diameter of the plate surface of the plate-like particle is determined by calculating the longest side of a quadrangle (rectangle or square) circumscribing the plate surface of the plate-like particle at each rotation angle while rotating the plate surface of the selected plate-like particle 360°. The longest side of the quadrangle is determined by calculating the longest side of the quadrangle circumscribing the plate surface at each rotation angle. The longest side of the quadrangle is determined by rotating the plate surface of the selected plate-like particle 360°.

[0038] In this specification, the "primary particle thickness D50 at which the cumulative frequency from the smaller thickness side in the volume-based cumulative thickness distribution of primary particles is 50%" is also referred to as the "volume-based cumulative 50% primary particle thickness."

[0039] The volume-based cumulative 50% primary particle thickness of the SPF improver is not particularly limited. When the SPF improver is a crystalline titanium phosphate powder, the volume-based cumulative 50% primary particle thickness of the crystalline titanium phosphate powder is not particularly limited.

[0040] The volume-based cumulative 50% primary particle thickness of the SPF enhancer and the volume-based cumulative 50% primary particle thickness of the crystalline titanium phosphate powder can be evaluated using a scanning electron microscope (SEM) and image analysis software "Mac-View ver. 4" manufactured by Mountec Co., Ltd. 100 to 200 primary particles are measured, and the thickness of each primary particle is determined. Here, when the primary particles are plate-like particles, the distance between the plate surfaces of the plate-like particles is taken as the primary particle thickness. Then, using the thickness of each primary particle, the value at which the cumulative frequency from the thinner side in the volume-based cumulative thickness distribution of the primary particles is 50% is calculated. The calculated value is taken as the primary particle thickness D50 (volume-based cumulative 50% primary particle thickness) at which the cumulative frequency from the thinner side in the volume-based cumulative thickness distribution of the primary particles is 50%.

[0041] In this specification, the aspect ratio of a primary particle represents the ratio of the volume-based cumulative 50% primary particle diameter to the volume-based cumulative 50% primary particle thickness (volume-based cumulative 50% primary particle diameter / volume-based cumulative 50% primary particle thickness).

[0042] The aspect ratio of the primary particles of the SPF improver is not particularly limited. The aspect ratio of the primary particles of the SPF improver is preferably 5.00 or more, more preferably 6.00 or more, and even more preferably 6.50 or more. The aspect ratio of the primary particles of the SPF improver is preferably 100.00 or less, more preferably 30.00 or less, even more preferably 10.00 or less, and particularly preferably 7.00 or less. Specific examples of ranges of the aspect ratio of the primary particles of the SPF enhancer include 5.00 or more and 100.00 or less, 5.00 or more and 30.00 or less, 5.00 or more and 10.00 or less, 5.00 or more and 7.00 or less, 6.00 or more and 100.00 or less, 6.00 or more and 30.00 or less, 6.00 or more and 10.00 or less, 6.00 or more and 7.00 or less, 6.50 or more and 100.00 or less, 6.50 or more and 30.00 or less, 6.50 or more and 10.00 or less, and 6.50 or more and 7.00 or less, but the ranges of the aspect ratio of the primary particles of the SPF enhancer are not limited to these.

[0043] When the SPF improver is a crystalline titanium phosphate powder, the aspect ratio of the primary particles of the crystalline titanium phosphate powder is not particularly limited.The aspect ratio of the primary particles of the crystalline titanium phosphate powder is preferably 5.00 or more, more preferably 6.00 or more, and even more preferably 6.50 or more.The aspect ratio of the primary particles of the crystalline titanium phosphate powder is preferably 100.00 or less, more preferably 30.00 or less, even more preferably 10.00 or less, and particularly preferably 7.00 or less. Specific examples of ranges of the aspect ratio of the primary particles of the crystalline titanium phosphate powder include 5.00 to 100.00, 5.00 to 30.00, 5.00 to 10.00, 5.00 to 7.00, 6.00 to 100.00, 6.00 to 30.00, 6.00 to 10.00, 6.00 to 7.00, 6.50 to 100.00, 6.50 to 30.00, 6.50 to 10.00, and 6.50 to 7.00, but the ranges of the aspect ratio of the primary particles of the crystalline titanium phosphate powder are not limited to these.

[0044] The method for producing the SPF enhancer is not particularly limited. The method for producing the SPF enhancer that is a crystalline titanium phosphate powder is not particularly limited, and examples thereof include a method that includes reacting raw materials containing titanium and phosphorus (e.g., raw materials containing a titanium-containing raw material and a phosphorus-containing raw material) by hydrothermal synthesis.

[0045] An example of a method for producing an SPF enhancer that is a crystalline titanium phosphate powder is a method that includes holding an acidic raw aqueous solution containing phosphorus and titanium in a sealed container at a temperature within a predetermined range for a predetermined time. A preferred example of this method includes placing the acidic raw aqueous solution containing phosphorus and titanium in a sealed container and holding the raw aqueous solution in the sealed container at a temperature within a predetermined range for a predetermined time. In this specification, the "acidic raw aqueous solution containing phosphorus and titanium" is also simply referred to as the "raw aqueous solution."

[0046] The raw aqueous solution is acidic. In this specification, acidic means that when the raw aqueous solution comes into contact with blue litmus paper manufactured by Advantech Toyo Co., Ltd., the blue litmus paper turns red.

[0047] The phosphorus concentration in the raw aqueous solution is not particularly limited, but is preferably 1.0% by mass or more and 30.0% by mass or less, more preferably 5.0% by mass or more and 30.0% by mass or less, even more preferably 6.8% by mass or more and 30.0% by mass or less, even more preferably more than 7.0% by mass or less and 20.0% by mass or less, particularly preferably 7.2% by mass or more and 18.0% by mass or less, even more particularly preferably 7.5% by mass or more and 20.0% by mass or less, and extremely preferably 9.0% by mass or more and 15.0% by mass or less. When the phosphorus concentration in the raw aqueous solution is above these lower limits, the volume-based cumulative 50% primary particle size of the crystalline titanium phosphate powder tends to be smaller, and the SPF improvement effect tends to be more enhanced. When the phosphorus concentration in the raw aqueous solution is below these upper limits, the volume-based cumulative 50% primary particle size of the crystalline titanium phosphate powder tends to be larger.

[0048] The titanium concentration in the raw aqueous solution is not particularly limited, but is preferably 0.1% by mass or more and 5.0% by mass or less, more preferably 0.2% by mass or more and 4.0% by mass or less, even more preferably 0.3% by mass or more and 3.0% by mass or less, particularly preferably 0.5% by mass or more and 2.5% by mass or less, and even more particularly preferably 1.0% by mass or more and 2.0% by mass or less, relative to the total mass of the raw aqueous solution. When the titanium concentration in the raw aqueous solution is equal to or greater than these lower limits, the yield of titanium phosphate tends to be improved. When the titanium concentration in the raw aqueous solution is equal to or less than these upper limits, gelation tends to be further reduced, and it tends to be easier to control the volume-based cumulative 50% primary particle size of the crystalline titanium phosphate powder.

[0049] The proton concentration in the raw aqueous solution is not particularly limited, but is preferably 6.0 mol / kg or more and 14.0 mol / kg or less, more preferably 9.0 mol / kg or more and 14.0 mol / kg or less, even more preferably 9.1 mol / kg or more and 14.0 mol / kg or less, still more preferably 9.2 mol / kg or more and 13.5 mol / kg or less, particularly preferably 9.5 mol / kg or more and 13.5 mol / kg or less, even more particularly preferably 10.0 mol / kg or more and 13.0 mol / kg or less, and extremely preferably 11.0 mol / kg or more and 12.0 mol / kg or less. When the proton concentration in the raw aqueous solution is above these lower limits, the volume-based cumulative 50% primary particle size of the crystalline titanium phosphate powder tends to be smaller, and the SPF improvement effect tends to be further enhanced. If the proton concentration in the raw material aqueous solution is below these upper limits, the volume-based cumulative 50% primary particle size of the crystalline titanium phosphate powder tends to be larger.

[0050] The phosphorus concentration in the raw aqueous solution, the titanium concentration in the raw aqueous solution, and the proton concentration in the raw aqueous solution can be determined from the types and amounts of raw materials used and the amount of raw aqueous solution produced, respectively.

[0051] The method for producing the raw aqueous solution is not particularly limited. As long as the raw aqueous solution can be obtained, the mixing method, mixing order, mixing conditions, etc. are not particularly limited, and known methods can be used. When producing the raw aqueous solution, each component contained in the raw aqueous solution may be added as is, or in the form of a solution, aqueous solution, dispersion, etc. The solvent and / or dispersion medium for these liquids is not particularly limited, and may be water or an organic solvent.

[0052] The method for producing an SPF enhancer that is a crystalline titanium phosphate powder preferably further comprises producing a raw solution. The method for producing the raw solution preferably comprises adding phosphorus as a phosphorus-containing substance and titanium as a titanium-containing substance. More preferably, the method for producing the raw solution further comprises adding an acid that is free of phosphorus and free of titanium.

[0053] An example of a method for producing a raw material aqueous solution includes mixing a phosphorus-containing substance, an aqueous solution containing the same, or a combination thereof, a titanium-containing substance, an aqueous solution containing the same, or a combination thereof, and a phosphorus-free, titanium-free acid, an aqueous solution containing the same, or a combination thereof. Among these, the method for producing a raw material aqueous solution preferably includes mixing an aqueous solution containing a phosphorus-containing substance, an aqueous solution containing a titanium-containing substance, and an aqueous solution containing a phosphorus-free, titanium-free acid. The method for producing a raw material aqueous solution may further include mixing, as necessary, a component other than the raw materials described above, an aqueous solution containing a component other than the raw materials described above, or a combination thereof. The mixing method, mixing order, mixing conditions, etc. in producing the raw material aqueous solution are not particularly limited.

[0054] The methods for producing the aqueous solution containing a phosphorus-containing substance, the aqueous solution containing a titanium-containing substance, and the aqueous solution containing a phosphorus-free, titanium-free acid are not particularly limited as long as they can produce the desired aqueous solutions. For example, known methods can be used as these production methods. In producing these aqueous solutions, the mixing method, mixing order, and mixing conditions are also not particularly limited. The aqueous solution containing a phosphorus-containing substance may further contain a phosphorus-free, titanium-free acid in addition to the phosphorus-containing substance. The aqueous solution containing a titanium-containing substance preferably further contains a phosphorus-free, titanium-free acid in addition to the titanium-containing substance.

[0055] Examples of phosphorus-containing substances include, but are not limited to, phosphoric acid and salts of phosphoric acid. The type of salt is not particularly limited. The phosphorus-containing substance may be used alone or in combination of two or more. The phosphorus-containing substance preferably includes phosphoric acid, a phosphate, or a combination thereof, and particularly preferably phosphoric acid.

[0056] Examples of titanium-containing substances include, but are not limited to, elemental titanium and titanium-containing compounds. The titanium-containing substances may be used alone or in combination of two or more. The titanium-containing compound is preferably titanium sulfate (Ti(SO ４ ) ２), titanyl sulfate (TioSO ４ ), titanium hydroxide, titanium oxide (e.g., titanium dioxide), etc. The titanium-containing substance preferably contains at least one compound selected from the group consisting of titanium sulfate, titanyl sulfate, titanium hydroxide, and titanium oxide (e.g., titanium dioxide), and particularly preferably at least one compound selected from the group consisting of titanium oxide and titanium sulfate.

[0057] Examples of the phosphorus-free, titanium-free acid include, but are not limited to, known organic acids and known inorganic acids. The phosphorus-free, titanium-free acid may be used alone or in combination of two or more. The phosphorus-free, titanium-free acid preferably includes at least one selected from the group consisting of hydrochloric acid, sulfuric acid, nitric acid, carbonic acid, acetic acid, citric acid, and formic acid, and particularly preferably sulfuric acid.

[0058] The sealed container is not particularly limited. The sealed container may be any container that can be sealed and can suppress the decrease of the filler filled in the container to a sufficient extent for producing the desired titanium phosphate. Examples of the sealed container include a first-class pressure vessel, a small pressure vessel, and other containers that can be sealed with a lid, a stopper, etc.

[0059] The temperature at which the raw material aqueous solution is held in a sealed container for a predetermined time within a predetermined temperature range (also referred to simply as the "holding temperature" in this specification) is not particularly limited, as long as it is a temperature at which crystalline titanium phosphate is produced. The holding temperature is preferably a temperature in the range of 40°C to 160°C, more preferably a temperature in the range of 85°C to 160°C, even more preferably a temperature in the range of 85°C to 135°C, even more preferably a temperature in the range of 85°C to 133°C, even more preferably a temperature in the range of 85°C to 130°C, particularly preferably a temperature in the range of 85°C to 120°C, and even more particularly preferably a temperature in the range of 85°C to 105°C. When the holding temperature is above these lower limits, crystalline titanium phosphate is produced more efficiently. When the holding temperature is below these upper limits, production using general-purpose equipment is possible, and productivity is further improved.

[0060] When the raw aqueous solution is held in a sealed container at a temperature within a predetermined range for a predetermined time, it is preferable that the temperature change within the holding temperature be as small as possible, and it is particularly preferable that the temperature change be within ±3°C (a temperature change of -3°C or more and 3°C or less). Thus, it is preferable that the raw aqueous solution be held in a sealed container at a holding temperature within the range of 40°C or more and 160°C or less, with a temperature change of ±3°C or less, for a predetermined time. It is more preferable that the raw aqueous solution be held in a sealed container at a holding temperature within the range of 85°C or more and 160°C or less, with a temperature change of ±3°C or less, for a predetermined time. It is even more preferable that the raw aqueous solution be held in a sealed container at a holding temperature within the range of 85°C or more and 135°C or less, with a temperature change of ±3°C or less, for a predetermined time. It is even more preferable that the raw aqueous solution be held in a sealed container at a holding temperature within the range of 85°C or more and 133°C or less, with a temperature change of ±3°C or less, for a predetermined time. It is more preferable to hold the raw aqueous solution in a sealed container at a holding temperature within the range of 85°C to 130°C with a temperature change of ±3°C for a predetermined period of time. It is particularly preferable to hold the raw aqueous solution in a sealed container at a holding temperature within the range of 85°C to 120°C with a temperature change of ±3°C for a predetermined period of time. It is even more particularly preferable to hold the raw aqueous solution in a sealed container at a holding temperature within the range of 85°C to 105°C with a temperature change of ±3°C for a predetermined period of time.

[0061] The time for holding the raw material aqueous solution in a sealed container at a temperature within a predetermined range for a predetermined time (also referred to simply as "holding time" in this specification) is not particularly limited, as long as it is the time required for crystalline titanium phosphate to be produced. The holding time is preferably 2 hours or more, more preferably 3 hours or more, and even more preferably 5 hours or more. When the holding time is within these ranges, crystalline titanium phosphate is produced more efficiently. The holding time is preferably 400 hours or less, more preferably 200 hours or less, and even more preferably 150 hours or less. When the holding time is within these ranges, the productivity of the SPF improver containing crystalline titanium phosphate is further increased. Specific examples of the holding time range include 2 hours to 400 hours, 3 hours to 200 hours, and 5 hours to 400 hours, but the holding time range is not limited to these.

[0062] The temperature of the raw material aqueous solution in the sealed container can be determined, for example, from the temperature around the sealed container. The temperature around the sealed container is preferably determined from the temperature around the sealed container obtained by measuring the temperature around the sealed container at intervals of 1 minute or less. The temperature around the sealed container can be measured, for example, at intervals of 1 minute. The temperature around the sealed container may also be measured, for example, at intervals shorter than 1 minute.

[0063] The method for heating the raw material aqueous solution in the sealed container is not particularly limited, but examples thereof include placing the sealed container in a thermostatic bath, and heating the sealed container with a heater attached to the sealed container.

[0064] When the raw aqueous solution is kept in a sealed container at a temperature within a predetermined range for a predetermined time, the pressure inside the sealed container becomes equal to or higher than atmospheric pressure, which is naturally determined by the heating temperature, for example.

[0065] The method for producing an SPF enhancer that is a crystalline titanium phosphate powder preferably further comprises the steps of: holding a raw material aqueous solution in a sealed container at a predetermined temperature for a predetermined time to obtain a slurry; cooling the obtained slurry and separating the solids from the slurry; and washing the obtained solids with a washing liquid and then drying the washing liquid. The washing liquid is not particularly limited, but examples thereof include water and aqueous ammonia (ammonium hydroxide).

[0066] The method for producing the SPF enhancer that is a crystalline titanium phosphate powder may further include steps other than those described above.

[0067] However, the method for producing the SPF enhancer is not limited to the method described above.

[0068] To improve cosmetic and pigment properties, the SPF enhancer may be subjected to at least one treatment selected from the group consisting of various polymer treatments, fluorine treatment, silicone treatment, alkylsilane treatment, alkyl titanate treatment, metal soap treatment, lauroyl lysine treatment, ester treatment, and amino acid treatment. The amino acid treatment is not particularly limited, and examples thereof include proline, hydroxyproline, alanine, glycine, sarcosine, aspartic acid, and / or glutamic acid.

[0069] The use of the SPF enhancer is not particularly limited. The SPF enhancer is preferably used as a raw material for a cosmetic (cosmetic composition) containing the SPF enhancer. Yet another aspect of the present invention relates to a cosmetic containing the above-mentioned SPF enhancer. The SPF enhancer is preferably used together with at least one selected from the group consisting of an ultraviolet scattering agent and an ultraviolet absorber. One preferred embodiment includes a cosmetic containing the SPF enhancer and at least one selected from the group consisting of an ultraviolet scattering agent and an ultraviolet absorber.

[0070] The form of the cosmetic is not particularly limited, and examples thereof include powder, oil, emulsion, etc. The cosmetic is not particularly limited, and examples thereof include makeup cosmetics such as makeup base, concealer, face powder, powder foundation, liquid foundation, cream foundation, oil foundation, lipstick, etc., UV protective cosmetics, etc. The UV protective cosmetics are not particularly limited, and examples thereof include sunscreen oil, sunscreen emulsion, sunscreen cream, etc.

[0071] The cosmetic may contain additional components other than the SPF enhancer, UV scattering agent, and UV absorber (also referred to simply as "additional components" in this specification) as needed, as long as the effects of the present invention are not impaired. The cosmetic may not contain any additional components. Examples of additional components include those typically used in cosmetics, such as solvents, oils, surfactants, moisturizers, antioxidants, thickeners, fragrances, colorants, physiologically active ingredients, and antibacterial agents. One type of additional component may be used alone, or two or more types may be used in combination. The content of the additional component is not particularly limited and can be set appropriately depending on the purpose.

[0072] The ultraviolet scattering agent is not particularly limited. For example, known ultraviolet scattering agents can be used as the ultraviolet scattering agent. For example, metal oxide particles can be used. The metal oxide constituting the metal oxide particles may be one type alone or two or more types. Examples of metal oxide particles include particles of titanium oxide, iron-containing titanium oxide, zinc oxide, cerium oxide, iron oxide, and composites thereof, but the metal oxide particles are not limited to these. The metal oxide particles preferably include at least one type of particle selected from the group consisting of titanium oxide, iron-containing titanium oxide, zinc oxide, cerium oxide, iron oxide, and composites thereof, and titanium oxide particles are particularly preferred.

[0073] The particle shape of the metal oxide particles is not particularly limited, and the metal oxide particles may be surface-treated particles.

[0074] As mentioned above, in this specification, the "primary particle diameter D50 at which the cumulative frequency from the small particle size side in the volume-based cumulative particle diameter distribution of primary particles is 50%" is also referred to as the "volume-based cumulative 50% primary particle diameter." When metal oxide particles are used as an ultraviolet scattering agent, the volume-based cumulative 50% primary particle diameter of the metal oxide particles is not particularly limited. The volume-based cumulative 50% primary particle diameter of the metal oxide particles is preferably 0.001 μm or more, more preferably 0.01 μm or more, and even more preferably 0.1 μm or more. When the volume-based cumulative 50% primary particle diameter of the metal oxide particles is within these ranges, aggregation of the metal oxide particles is further suppressed. The volume-based cumulative 50% primary particle diameter of the metal oxide particles is preferably 10 μm or less, more preferably 5 μm or less, even more preferably 1 μm or less, and particularly preferably 0.5 μm or less. When the volume-based cumulative 50% primary particle diameter of the metal oxide particles is within these ranges, ultraviolet rays can be scattered more efficiently. When metal oxide particles are used as an ultraviolet scattering agent, specific examples of the range of the volume-based cumulative 50% primary particle diameter of the metal oxide particles (volume-based cumulative 50% primary particle diameter of the metal oxide particles) include 0.001 μm or more and 10 μm or less, 0.01 μm or more and 1 μm or less, 0.1 μm or more and 1 μm or less, and 0.1 μm or more and 0.5 μm or less, but the range of the volume-based cumulative 50% primary particle diameter of the metal oxide particles is not limited to these.

[0075] The volume-based cumulative 50% primary particle diameter of metal oxide particles can be evaluated using a scanning electron microscope (SEM) and image analysis software "Mac-View ver. 4" manufactured by Mountec Co., Ltd. 100 to 200 primary particles are measured, and the longest diameter of each primary particle is determined. The obtained value is the individual primary particle diameter. The longest diameter of the primary particle is determined by the length of the longest side of a quadrangle (rectangle or square) circumscribing the primary particle. Here, the quadrangle with the longest side is determined by rotating the selected primary particle 360° and calculating the quadrangle circumscribing the primary particle at each rotation angle. The quadrangle with the longest side is used. Then, using the individual primary particle diameters, the value at which the cumulative frequency from the small particle size side is 50% is calculated in the volume-based cumulative particle size distribution of the primary particles. The calculated value is defined as the primary particle diameter D50 (volume-based cumulative 50% primary particle diameter) at which the cumulative frequency from the small particle size side in the volume-based cumulative particle diameter distribution of primary particles is 50%.

[0076] In the measurement and calculation of the volume-based cumulative 50% primary particle diameter, when the primary particles are plate-like particles, the longest diameter of the primary particles represents the longest diameter of the plate surface of the plate-like particle. The longest diameter of the plate surface of the plate-like particle is determined by calculating the longest side of a quadrangle (rectangle or square) circumscribing the plate surface of the plate-like particle at each rotation angle while rotating the plate surface of the selected plate-like particle 360°. The longest side of the quadrangle is determined by calculating the longest side of the quadrangle circumscribing the plate surface at each rotation angle.

[0077] The SPF improver is preferably used together with titanium oxide particles. The SPF improver is more preferably used together with pigment-grade titanium oxide. One embodiment of the present invention includes a cosmetic comprising an SPF improver and pigment-grade titanium oxide. In this specification, pigment-grade titanium oxide refers to titanium oxide particles having a volume-based cumulative 50% primary particle diameter of 0.1 μm or more. The SPF improver is more preferably used together with titanium oxide particles having a volume-based cumulative 50% primary particle diameter of 0.1 μm or more and 1 μm or less, and is particularly preferably used together with titanium oxide particles having a volume-based cumulative 50% primary particle diameter of 0.1 μm or more and 0.5 μm or less. The method for evaluating the volume-based cumulative 50% primary particle diameter of titanium oxide particles is the same as the method for evaluating the volume-based cumulative 50% primary particle diameter of metal oxide particles described above.

[0078] The ultraviolet scattering agent may be a commercially available product or a synthetic product. Examples of titanium oxide particles that can be used as an ultraviolet scattering agent include TiO2 CR-50 manufactured by Daito Chemical Industry Co., Ltd.

[0079] The ultraviolet scattering agent may be used alone or in combination of two or more kinds.

[0080] The ultraviolet absorber is not particularly limited. Known ultraviolet absorbers can be used as the ultraviolet absorber. Examples of ultraviolet absorbers include, but are not limited to, benzotriazole-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, triazine-based ultraviolet absorbers, salicylate-based ultraviolet absorbers, oxanilide-based ultraviolet absorbers, cinnamic acid-based ultraviolet absorbers, and benzoylmethane-based ultraviolet absorbers. The ultraviolet absorber may be a commercially available product or a synthetic product. One type of ultraviolet absorber may be used alone, or two or more types may be used in combination.

[0081] When an SPF enhancer is used together with at least one selected from the group consisting of an ultraviolet scattering agent and an ultraviolet absorber, the ratio of the mass of the SPF enhancer to the total mass of the SPF enhancer, ultraviolet scattering agent, and ultraviolet absorber (mass of SPF enhancer / total mass of SPF enhancer, ultraviolet scattering agent, and ultraviolet absorber) is not particularly limited. When a cosmetic contains an SPF enhancer and at least one selected from the group consisting of an ultraviolet scattering agent and an ultraviolet absorber, the ratio of the mass of the SPF enhancer to the total mass of the SPF enhancer, ultraviolet scattering agent, and ultraviolet absorber (mass of SPF enhancer / total mass of SPF enhancer, ultraviolet scattering agent, and ultraviolet absorber) is not particularly limited. The ratio of the mass of the SPF enhancer to the total mass of the SPF enhancer, ultraviolet scattering agent, and ultraviolet absorber is preferably 0.01 or more and 0.99 or less, more preferably 0.10 or more and 0.50 or less, and even more preferably 0.15 or more and 0.30 or less. When two or more UV scattering agents are used, the mass of the UV scattering agents is the total mass of these. When two or more UV absorbers are used, the mass of the UV absorbers is the total mass of these. When two or more SPF improvers are used, the mass of the SPF improvers is the total mass of these.

[0082] When an SPF enhancer and an UV scattering agent are used together, the ratio of the mass of the SPF enhancer to the total mass of the SPF enhancer and the UV scattering agent (mass of SPF enhancer / total mass of SPF enhancer and UV scattering agent) is not particularly limited. When a cosmetic contains an SPF enhancer and a UV scattering agent, the ratio of the mass of the SPF enhancer to the total mass of the SPF enhancer and the UV scattering agent (mass of SPF enhancer / total mass of SPF enhancer and UV scattering agent) is not particularly limited. The ratio of the mass of the SPF enhancer to the total mass of the SPF enhancer and the UV scattering agent is preferably 0.01 or more and 0.99 or less, more preferably 0.10 or more and 0.50 or less, and even more preferably 0.15 or more and 0.30 or less. When two or more UV scattering agents are used, the mass of the UV scattering agent is the total mass of these. When two or more SPF enhancers are used, the mass of the SPF enhancers is the total mass of these enhancers.

[0083] The content of the SPF enhancer in the cosmetic is not particularly limited. The content of the SPF enhancer in the cosmetic is preferably 0.1% by mass or more and 50% by mass or less, relative to the total mass of the cosmetic, more preferably 0.5% by mass or more and 25% by mass or less, relative to the total mass of the cosmetic, and even more preferably 1% by mass or more and 10% by mass or less, relative to the total mass of the cosmetic. When the content of the SPF enhancer in the cosmetic is within these ranges, it becomes possible to efficiently improve the SPF without any restrictions on the blending of other components of the cosmetic.

[0084] The method for producing the cosmetic is not particularly limited. For example, the method for producing the cosmetic may include a method including mixing the SPF enhancer with other components that constitute the cosmetic.

[0085] Although the embodiments of the present invention have been described in detail, it is clear that this is for illustrative and exemplary purposes only and not for limitation, and that the scope of the present invention should be interpreted by the appended claims.

[0086] The present invention encompasses the following aspects and embodiments: [1] The maximum light intensity I at a light receiving angle in the range of -42° to -40.5° when all light rays are irradiated from an incident angle of -45°, with the normal to the surface to which the SPF improver is applied being 0°. Ｅ The normal to the surface to which the SPF improver is applied is taken as 0°, and the light intensity I at a receiving angle of 45° when all light rays are irradiated from an incident angle of -45° is Ｒ I is the ratio of Ｒ / I Ｅ [2] The SPF improver according to the above [1], wherein the haze for light having a wavelength of 310 nm, represented by the following formula, is 75.0% or more.

[0087] Haze at light with a wavelength of 310 nm (unit: %) = (diffuse transmittance at light with a wavelength of 310 nm / total light transmittance at light with a wavelength of 310 nm) × 100 [3] The SPF improver according to the above [1] or [2], which contains plate-like particles. [4] The SPF improver according to any one of the above [1] to [3], which is a crystalline titanium phosphate powder. [5] The SPF improver according to any one of the above [1] to [4], which has a primary particle diameter D50 at which the cumulative frequency from the small particle size side in the volume-based cumulative particle diameter distribution of the primary particles is 50% of 0.1 μm or more and 4 μm or less. [6] The SPF improver, which is a crystalline titanium phosphate powder, has a primary particle diameter D50 at which the cumulative frequency from the small particle size side in the volume-based cumulative particle diameter distribution of the primary particles is 50% of 0.1 μm or more and 10 μm or less. [7] The SPF improver according to [6] above, wherein the primary particle size D50 is 0.1 μm or more and 4 μm or less. [8] The SPF improver according to [6] above or [7] above, wherein the crystalline titanium phosphate powder comprises plate-like particles. [9] The SPF improver according to any one of [1] to [8] above, which is used together with at least one selected from the group consisting of an ultraviolet scattering agent and an ultraviolet absorbing agent.

[10] The SPF improver according to any one of [1] to [9] above, which is used together with pigment-grade titanium dioxide.

[11] A cosmetic comprising the SPF improver according to any one of [1] to

[10] above, and at least one selected from the group consisting of an ultraviolet scattering agent and an ultraviolet absorbing agent.

[12] A cosmetic comprising the SPF improver according to any one of [1] to

[10] above, and pigment-grade titanium dioxide.

[0088] The present invention will be described in more detail using the following examples and comparative examples. However, the technical scope of the present invention is not limited to the following examples. Unless otherwise specified, "%" and "parts" mean "% by mass" and "parts by mass", respectively. In the following examples, unless otherwise specified, the operations were carried out at room temperature (25°C).

[0089] <Production of SPF Improver> [Production of SPF Improver 1] An acidic aqueous mixture solution was obtained by adding, with stirring, the titanium sulfate aqueous solution A and a 96% by mass aqueous sulfuric acid aqueous solution to an 85% by mass aqueous phosphoric acid solution so that the titanium concentration was 1.4% by mass, the phosphorus concentration was 9.2% by mass, and the proton concentration per 1 kg of the aqueous mixture solution was 11.2 mol / kg, relative to the total mass of the aqueous mixture solution. The obtained acidic aqueous mixture solution was used as the raw material aqueous solution.

[0090] Here, the titanium sulfate aqueous solution A is an aqueous solution containing titanium in an amount equivalent to 8 mass % of titanium dioxide relative to the total mass of the titanium sulfate aqueous solution A, and sulfuric acid in an amount of 35 mass % relative to the total mass of the titanium sulfate aqueous solution A.

[0091] The acidity of the resulting aqueous mixture solution was confirmed by the fact that when the aqueous mixture solution came into contact with litmus paper (blue) manufactured by Advantech Toyo Co., Ltd., the test paper turned red.

[0092] Next, the obtained aqueous mixture solution (raw material aqueous solution) was placed in a sealed container, and the temperature around the sealed container was maintained within 90°C ± 3°C, and the reaction was carried out for 5 hours. That is, the conditions for maintaining the aqueous mixture solution in the sealed container were a maintaining temperature of 90°C ± 3°C and a maintaining time of 5 hours. The temperature around the sealed container was measured at 1-minute intervals.

[0093] After the reaction, the lid was opened and the slurry in the container was cooled to room temperature. The container was then removed and the solid matter was separated from the slurry by filtration. The solid matter was washed with water and then dried (at 105°C for 24 hours) to obtain a powder. The obtained powder was used as SPF improver 1.

[0094] [Production of SPF Enhancers 2 to 6] SPF enhancers 2 to 6 were each produced in the same manner as in the production of SPF enhancer 1, except that an acidic aqueous mixture solution (raw material aqueous solution) was obtained by adding, with stirring, the above titanium sulfate aqueous solution A and a 96% by mass aqueous sulfuric acid solution to an 85% by mass aqueous phosphoric acid solution so that the titanium concentration, phosphorus concentration, and proton concentration in the resulting aqueous mixture solution would each be the values ​​shown in Table 1, and that the holding temperature and holding time were set to the values ​​shown in Table 1.

[0095]

[0096] [Preparation of SPF enhancer 7] As SPF enhancer 7, CARESS BN02, a commercially available boron nitride product manufactured by Bent Tree Industries Europe, was used.

[0097] [Crystallinity of Titanium Phosphate] XRD (X-ray Diffraction) measurements were carried out on the SPF enhancers 1 to 6 obtained above by powder X-ray diffraction.

[0098] Details of the XRD measurement are shown below: <XRD measurement conditions> Measurement device: Rigaku Corporation, horizontal sample type multipurpose X-ray diffractometer Ultima IV X-ray: 20 kV / 10 mA Divergence slit: 1° Divergence vertical limiting slit: 10 mm Scattering slit: 2° Receiving slit: 0.05 mm kβ filter Start: 10 Stop: 70 Step: 0.01 Standard card: 01-079-7347 (Ti(HPO ４ ) ２ ・H ２ O).

[0099] In this measurement, for SPF enhancers 2 to 6, the highest peak was confirmed at a diffraction angle (2θ) of approximately 11.6°, and the second highest peak was confirmed at a diffraction angle (2θ) of approximately 25.7°. For SPF enhancer 1, the highest peak was confirmed at a diffraction angle (2θ) of approximately 25.7°, and the second highest peak was confirmed at a diffraction angle (2θ) of approximately 11.6°. Furthermore, for SPF enhancers 1 to 6, including the first and second highest peaks, the chemical formula: Ti(HPO ４ ) ２ ・H ２ A peak characteristic of the titanium phosphate crystal represented by O was observed, and no peaks other than those observed in the titanium phosphate crystal were observed.

[0100] From the results of this measurement, in the production of SPF enhancers 1 to 6, the structural formula was Ti(HPO ４ ) ２ ・H ２ It was confirmed that crystalline titanium phosphate having a molecular weight of O was produced. From the results of this measurement, it was determined that SPF enhancers 1 to 6 were crystalline titanium phosphate powders.

[0101] FIG. 2 is a graph showing the results of XRD measurement of SPF enhancer 3 and the results of XRD measurement of standard card: 01-079-7347.

[0102] [Particle Shape, Volume-Based Cumulative 50% Primary Particle Diameter, and Aspect Ratio of Primary Particles] The particle shape, volume-based cumulative 50% primary particle diameter, and aspect ratio of primary particles of SPF enhancers 1 to 7 and talc hydrogen dimethicone (TALK JA 13R AS, manufactured by K.S. PEARL) described below were evaluated using a scanning electron microscope (SEM).

[0103] (Particle Shape) Each SPF improver and talc hydrogen dimethicone (TALK JA 13R AS, manufactured by K.S. PEARL) were suspended in methanol, dropped onto aluminum foil, and then dried at room temperature to prepare measurement samples. SEM images of these measurement samples were taken using a scanning electron microscope (SEM) (SU8000, manufactured by Hitachi High-Technologies Corporation) to observe the particle shape.

[0104] From the above measurements, it was confirmed that the primary particles of SPF enhancers 1 to 6 were plate-like.

[0105] It was also confirmed that the shape of the primary particles of SPF enhancer 7 was plate-like. It was also confirmed that the shape of the primary particles of talc hydrogen dimethicone (TALK JA 13R AS, manufactured by K.S. PEARL) was plate-like.

[0106] From the results of the XRD measurement by the powder X-ray diffraction method described above and the results of this evaluation, it was determined that SPF enhancers 1 to 6 were crystalline titanium phosphate powders containing plate-like particles.

[0107] An SEM image of SPF enhancer 3 is shown in FIG.

[0108] (Volume-based cumulative 50% primary particle size and aspect ratio of primary particles) Each SPF improver and talc hydrogen dimethicone (TALK JA 13R AS, manufactured by K.S. PEARL) were each suspended in methanol, dropped onto aluminum foil, and then dried at room temperature to prepare measurement samples. SEM images of these measurement samples were taken multiple times at randomly different positions using a scanning electron microscope (SEM) (SU8000, manufactured by Hitachi High-Tech Corporation). Next, particles were measured for the obtained multiple SEM images using image analysis software "Mac-View ver. 4" manufactured by Mountec Co., Ltd.

[0109] 100 to 200 primary particles were measured, and the longest diameter of each primary particle was determined. The obtained value was designated as the individual primary particle diameter. The longest diameter of the plate surface of the plate-like particle was used as the longest diameter of the primary particle. Here, the longest diameter of the plate surface of the plate-like particle was determined by the length of the longest side of the quadrangle (rectangle or square) circumscribing the plate surface of the plate-like particle. The quadrangle with the longest side was determined by rotating the plate surface of the selected plate-like particle 360° and calculating the quadrangle circumscribing the plate surface at each rotation angle. The quadrangle with the longest side was selected. Then, using each primary particle diameter, the value at which the cumulative frequency from the small particle size side in the volume-based cumulative particle size distribution of the primary particles was calculated was used. The calculated value was designated as the primary particle diameter D50 (volume-based cumulative 50% primary particle diameter) (μm), at which the cumulative frequency from the small particle size side in the volume-based cumulative particle size distribution of the primary particles was 50%.

[0110] 100 to 200 primary particles were measured, and the thickness of each primary particle was determined. The distance between the plate surfaces of the plate-like particles was used as the thickness of the primary particle. Then, using the thickness of each primary particle, a value at which the cumulative frequency from the thinner side in the volume-based cumulative thickness distribution of the primary particles was 50% was calculated. The calculated value was designated as the primary particle thickness D50 (volume-based cumulative 50% primary particle thickness) (μm) at which the cumulative frequency from the thinner side in the volume-based cumulative thickness distribution of the primary particles was 50%.

[0111] Then, the volume-based cumulative 50% primary particle diameter (μm) and the volume-based cumulative 50% primary particle thickness (μm) obtained by the above measurement were used to calculate the aspect ratio of the primary particles (=volume-based cumulative 50% primary particle diameter (μm) / volume-based cumulative 50% primary particle thickness (μm)).

[0112] The volume-based cumulative 50% primary particle size and the aspect ratio of the primary particles of each SPF enhancer are shown in Tables 3 and 4.

[0113] [Reflection and scattering properties] A measurement sample was obtained by uniformly applying the SPF enhancer described above using a cosmetic brush to artificial leather, Protein Leather Suppler manufactured by Ideatex Japan Co., Ltd. The measurement sample was then measured using a three-dimensional goniophotometer GP-200 manufactured by Murakami Color Research Laboratory Co., Ltd., with an incident angle of −45° and a light receiving angle of −90 to 90°.

[0114] The normal to the surface to which the SPF improver is applied is taken as 0°, and the maximum light intensity I is the maximum light intensity I at an incident angle in the range of -42° to -40.5° when all light rays are irradiated from an incident angle of -45°. Ｅ , and the light intensity I at a receiving angle of 45° when all light rays are irradiated from an incident angle of −45°, with the normal to the surface to which the SPF improver is applied being 0°. Ｒ From the measurement results, I Ｅ I against Ｒ The ratio (I Ｒ / I Ｅ ) was calculated. Ｒ / I Ｅ was used as an index of reflection / scattering property.

[0115] [UV Scattering Transmittance] The above SPF improver, acrylic silicone film-forming agent (KP-545, manufactured by Shin-Etsu Chemical Co., Ltd.), and volatile silicone oil (KF96L-2CS, manufactured by Shin-Etsu Chemical Co., Ltd.) were dispersed and mixed using a homomixer to obtain a slurry containing 9% by mass of the SPF improver relative to the total mass of the slurry, 70% by mass of the acrylic silicone film-forming agent relative to the total mass of the slurry, and 21% by mass of the volatile silicone oil relative to the total mass of the slurry. Next, a small amount of the obtained slurry was sampled on a glass slide, applied using a bar coater with a wet film thickness of 25 μm, and dried at room temperature (room temperature) to obtain a coating film. The content of the SPF improver relative to the total mass of the obtained coating film was 30% by mass. The obtained coating film was measured under the following conditions using a spectrophotometer consisting of a UV-2450 ultraviolet-visible spectrophotometer manufactured by Shimadzu Corporation equipped with an ISR-2200 integrating sphere manufactured by Shimadzu Corporation.

[0116] <Spectrophotometer measurement conditions> Measurement items: total light transmittance (measurement of coating film only), diffuse transmittance (measurement of coating film only) Measurement wavelength: 290-860 nm, 1 nm pitch Incident light: θ=0°.

[0117] The haze (unit: %) for light with a wavelength of 310 nm was calculated from the results of the diffuse transmittance (unit: %) for light with a wavelength of 310 nm and the total light transmittance (unit: %) for light with a wavelength of 310 nm according to the following formula: The haze for light with a wavelength of 310 nm was used as an index of ultraviolet scattering transmittance.

[0118] Haze at light with a wavelength of 310 nm (unit: %) = (diffuse transmittance at light with a wavelength of 310 nm / total light transmittance at light with a wavelength of 310 nm) × 100 [UV Blocking Effect] (Preparation of Measurement Cosmetic) The components (A1 to A6) listed in "A" in Table 2 were uniformly mixed using a disperser to obtain a mixture M(A) liquid. Next, the components (B1 to B7) listed in "B" in Table 2 were weighed and mixed using a mixer to obtain a mixture M(B). Then, mixture M(A) was added to mixture M(B), and the mixture of mixture M(A) and mixture M(B) was mixed using a mixer to produce a powder foundation. The produced powder foundation was used as the measurement cosmetic. The content (mass %) of each component relative to the total mass of the produced measurement cosmetic (powder foundation) is shown in Table 2.

[0119] The measurement samples were prepared as follows: Measurement Cosmetics 1 to 6 and 8, each of which had Measurement Cosmetic 7 as the basic composition, but in which a portion of the talc hydrogen dimethicone (TALK JA 13R AS, manufactured by K.S. PEARL) in Measurement Cosmetic 7 was replaced with the above-mentioned SPF enhancer.

[0120] As component B6 in Table 2, 3.26 mass% of HP Iron Oxide Yellow 3AS relative to the total mass of the cosmetic preparation for measurement, 0.66 mass% of HP Iron Oxide Red 3AS relative to the total mass of the cosmetic preparation for measurement, and 0.24 mass% of HP Iron Oxide Black 3AS relative to the total mass of the cosmetic preparation for measurement were used.

[0121] As component B7 in Table 2, 0.1% by mass of Metxance-M relative to the total mass of the cosmetic preparation for measurement and 0.05% by mass of Metxance-P relative to the total mass of the cosmetic preparation for measurement were used.

[0122] (Volume-based cumulative 50% primary particle diameter of titanium oxide particles) Titanium oxide-triethoxycaprylylsilane (TiO2 CR-50, Daito Kasei Kogyo Co., Ltd.), component B4 described below, was suspended in methanol, dropped onto aluminum foil, and then dried at room temperature to prepare a measurement sample. SEM images of this measurement sample were taken multiple times at randomly different positions using a scanning electron microscope (SEM). Next, particles were measured for the obtained multiple SEM images using image analysis software "Mac-View ver. 4" manufactured by Mountech Co., Ltd.

[0123] 100 to 200 primary particles were measured, and the longest diameter of each primary particle was determined. The resulting value was designated as the individual primary particle diameter. The longest diameter of each primary particle was determined by the length of the longest side of a quadrangle (rectangle or square) circumscribing the primary particle. The selected primary particle was rotated 360°, and the quadrangles circumscribing the primary particle at each rotation angle were calculated. The quadrangle with the longest side was selected. Each primary particle diameter was then used to calculate the value at which the cumulative frequency from the small particle size side in the volume-based cumulative particle size distribution of the primary particles was 50%. The calculated value was designated as the primary particle diameter D50 (volume-based cumulative 50% primary particle diameter), at which the cumulative frequency from the small particle size side in the volume-based cumulative particle size distribution of the primary particles was 50%.

[0124] As a result of this evaluation, it was confirmed that the volume-based cumulative 50% primary particle size of titanium oxide triethoxycaprylylsilane (TiO2 CR-50, Daito Kasei Kogyo Co., Ltd.), which is component B4 described below, was 0.29 μm.

[0125] (Evaluation of UV-Shielding Effect) The test cosmetic obtained above was applied to an acrylic resin plate (HelioScreen, product name Helioplate SB6, PMMA) using a fingertip cot to obtain a coating film on the acrylic resin plate. Next, using a spectrophotometer, a Shimadzu UV-2450 UV-visible spectrophotometer equipped with a Shimadzu ISR-2200 integrating sphere, the total light transmittance (%) of the coating film on the acrylic resin plate was measured under the following conditions at a total of four locations: two locations equidistantly spaced vertically and two locations equidistantly spaced horizontally. The measurement was performed with light incident from the acrylic resin plate side. The average value of the total light transmittance (%) at a wavelength of 310 nm at each location was then calculated to obtain the average value of the total light transmittance (%) of the coating film of the test cosmetic at a wavelength of 310 nm. The average value of the total light transmittance at a wavelength of 310 nm of the coating film of the cosmetic preparation to be measured was used as a measure of the sun protection factor (SPF). It was determined that the smaller the average value of the total light transmittance at a wavelength of 310 nm of the coating film of the cosmetic preparation to be measured, the greater the SPF and the greater the SPF improving effect of the SPF improver.

[0126] <Spectrophotometer measurement conditions> Measurement item: Total light transmittance (measurement of coating film on acrylic resin plate) Measurement wavelength: 290-860 nm, 1 nm pitch Incident light: θ=0°.

[0127] SPF enhancer I Ｒ / I Ｅ The haze of the SPF improver at a wavelength of 310 nm and the average total light transmittance of the coating film of the cosmetic preparation at a wavelength of 310 nm are shown in Tables 3 and 4, respectively.

[0128] In Tables 3 and 4, the content (mass %) of "titanium oxide" represents the content of titanium oxide / triethoxycaprylylsilane (TiO2 CR-50, manufactured by Daito Chemical Industry Co., Ltd.) relative to the total mass of the cosmetic preparation being measured.

[0129] In Tables 3 and 4, the content (mass%) of each SPF enhancer represents the content of each SPF enhancer relative to the total mass of the cosmetic preparation used for measurement. In Tables 3 and 4, the blank spaces for the content of SPF enhancer indicate that the cosmetic preparation used for measurement does not contain the type of SPF enhancer corresponding to the blank space.

[0130] In Tables 3 and 4, the content (mass %) of "part of talc" represents the content of a portion of talc (talc hydrogen dimethicone (TALC JA 13R AS, K.S. PEARL)) relative to the total mass of the measurement cosmetic. Here, the content of talc in measurement cosmetic 7 is the sum of the content of "part of talc" in Table 4 and the content of talc contained in "other ingredients" in Table 4. As shown in Table 2, the content of talc in measurement cosmetic 7 is 11.68 mass % relative to the total mass of measurement cosmetic 7. In Tables 3 and 4, the blank space for the content of "part of talc" indicates that the measurement cosmetic contains only talc contained in "other ingredients." In measurement cosmetics 1 to 6 and 8, all talc is included in "other ingredients," and the talc contents in these measurement cosmetics are as shown in Table 2.

[0131] In Tables 3 and 4, the content (mass %) of "other components" represents the total content of each component, excluding "titanium oxide" and the SPF enhancer, relative to the total mass of the cosmetic for measurement 1 to 6 and 8, and represents the total content of each component, excluding "titanium oxide" and "a portion of talc," relative to the total mass of the cosmetic for measurement 7.

[0132]

[0133]

[0134]

[0135] From the above results, it was confirmed that the test cosmetics using the SPF enhancers according to the Examples had a smaller average value of total light transmittance at a wavelength of 310 nm and achieved an excellent SPF compared to Test Cosmetic 7, which did not use an SPF enhancer according to the Examples. It was confirmed that Test Cosmetics 1 to 4, which used SPF enhancers 1 to 4 according to the Examples, had a particularly small average value of total light transmittance at a wavelength of 310 nm and achieved a significantly excellent SPF.

[0136] On the other hand, it was confirmed that the test cosmetic 8 using the SPF enhancer 7 according to the comparative example had a larger average value of total light transmittance at a wavelength of 310 nm and was inferior in SPF compared to the test cosmetic using the SPF enhancer according to the example.

[0137] 1 Surface coated with SPF enhancer 2 Incident light This application is based on Japanese Patent Application No. 2023-173765, filed on October 5, 2023, the disclosure of which is incorporated by reference in its entirety.

Claims

1. The maximum light intensity I at a receiving angle in the range of -42° to -40.5° when all light rays are irradiated from an incident angle of -45°, with the normal to the surface to which the SPF enhancer is applied being 0°. Ｅ The normal to the surface to which the SPF enhancer is applied is taken as 0°, and the light intensity I at a receiving angle of 45° when all light rays are irradiated from an incident angle of -45° is Ｒ I is the ratio of Ｒ / I Ｅ is 1.00 or greater and 2.80 or less.

2. The SPF improver according to claim 1, which has a haze at 310 nm wavelength, expressed by the following formula, of 75.0% or more: Haze at 310 nm wavelength (unit: %) = (diffuse transmittance at 310 nm wavelength / total light transmittance at 310 nm wavelength) x 100 3. The SPF enhancer of claim 1 or 2, comprising plate-like particles.

4. The SPF enhancer according to claim 1 or 2, which is a crystalline titanium phosphate powder.

5. An SPF enhancer according to claim 1 or 2, wherein the primary particle diameter D50 at which the cumulative frequency from the small particle size side in the volume-based cumulative particle diameter distribution of primary particles is 50% is 0.1 μm or more and 4 μm or less.

6. An SPF improver which is a crystalline titanium phosphate powder having a primary particle diameter D50 of 0.1 μm or more and 10 μm or less, at which the cumulative frequency from the small particle size side in the volume-based cumulative particle diameter distribution of primary particles is 50%.

7. The SPF improver according to claim 6, wherein the primary particle diameter D50 is 0.1 μm or more and 4 μm or less.

8. The SPF enhancer of claim 6 or 7, wherein the crystalline titanium phosphate powder comprises platelet-shaped particles.

9. The SPF improver according to claim 1, 2, 6 or 7, which is used together with at least one selected from the group consisting of ultraviolet scattering agents and ultraviolet absorbing agents.

10. The SPF enhancer of claim 1, 2, 6 or 7 used in combination with pigmentary grade titanium dioxide.

11. A cosmetic preparation comprising the SPF enhancer according to claim 1, 2, 6 or 7, and at least one selected from the group consisting of ultraviolet scattering agents and ultraviolet absorbing agents.

12. A cosmetic preparation comprising the SPF enhancer according to claim 1, 2, 6 or 7 and pigment-grade titanium dioxide.

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