JP7596068B2 - Spherical hydrophobic silica aerogel and cosmetic composition comprising composite and/or hollow silica particles - Google Patents

Description

The present invention relates to a cosmetic composition comprising (i) at least one type of spherical hydrophobic silica aerogel and (ii) at least one type of composite silica particle and/or at least one type of hollow silica particle, which is unclear or opaque for a long period of time and can thereby conceal pores and greasiness.

Durability is one of the most important factors for cosmetic compositions, especially foundations. To achieve durability, film formers such as MQ resins are used in combination with a specific combination of fillers. However, most fillers used in cosmetic compositions are synthetic organic polymers classified as microplastics, such as PMMA, nylon, and polyurethane. Due to the risk of inducing environmental damage caused by microplastics, there is a need to replace synthetic organic polymers with more environmentally friendly fillers derived from natural sources, such as silica.

Therefore, currently, silylated silica aerogel particles, such as VM-2270 aerogel microparticles sold by Dow Corning, are used in cosmetic compositions. These particles are capable of absorbing large amounts of sebum and are suitable for use in foundations. However, these particles do not have a fixed shape. Due to this irregular shape, the texture becomes very poor when these particles are included in large amounts in cosmetic compositions.

Spherical silylated silica aerogel particles have been recently developed, and it is suggested that these particles impart a matte effect and good smoothness to cosmetic compositions while maintaining high oil absorption (JP-A-2014-088307, JP-A-2014-218433, and JP-A-2018-177620). However, when the spherical silylated silica aerogel particles are under wet conditions, the composition becomes transparent. Therefore, there is a drawback in that over time, the cosmetic composition containing the spherical silylated silica aerogel particles becomes transparent due to sweat or sebum, making the pores and wrinkles of the skin more noticeable.

There is therefore a need to provide a cosmetic composition containing spherical aerogel particles, such as spherical silylated silica aerogel particles, that remains unclear or opaque for extended periods of time, even under humid conditions.

JP-A-2014-088307 JP-A-2014-218433 JP-A-2018-177620

Barrett, E. P.; Joyner, L. G.; Halenda, P. P., J. Am. Chem. Soc. 73, 373 (1951)

The object of the present invention is to provide a cosmetic composition containing spherical hydrophobic silica aerogel that remains unclear or opaque for a long period of time even when used under wet conditions.

The above object can be achieved by a cosmetic composition comprising (i) at least one type of spherical hydrophobic silica aerogel and (ii) at least one type of composite silica particle and/or at least one type of hollow silica particle.

The spherical hydrophobic silica aerogel may be a spherical hydrophobic aerogel of silica silylate.

The average circularity of the spherical hydrophobic silica aerogel determined by image analysis is 0.8 or more, preferably 0.82 or more, and may be less than 1, preferably 0.99 or less, more preferably 0.98 or less, even more preferably 0.97 or less, even more preferably 0.96 or less, and most preferably 0.95 or less.

The oil absorption capacity of the spherical hydrophobic silica aerogel measured at the wet point may be 2 ml/g or more, preferably 3 ml/g or more, more preferably 4 ml/g or more, and most preferably 5 ml/g or more, and may be 12 ml/g or less, preferably 11 ml/g or less, more preferably 10 ml/g or less, and most preferably 8 ml/g or less.

The spherical hydrophobic silica gel may have at least one of the following characteristics:
a specific surface area, determined by the BET method, of 200 m ² /g or more, preferably 400 m ² /g or more, more preferably 500 m ² /g or more, and up to 1200 m ² /g, preferably 1000 m ² /g or less, more preferably 800 m ² /g or less;
- a pore volume determined by the BJH method of at least 1 ml/g, preferably at least 2 ml/g, more preferably at least 3 ml/g, and at most 10 ml/g, preferably at most 8 ml/g, more preferably at most 7 ml/g;
a peak pore radius, determined by the BJH method, equal to or greater than 5 nm, preferably equal to or greater than 10 nm, more preferably equal to or greater than 12 nm, and equal to or less than 50 nm, preferably equal to or less than 30 nm, more preferably equal to or less than 25 nm.

The average particle size of the spherical hydrophobic silica gel can be 0.5 μm or more, preferably 1 μm or more, more preferably 2 μm or more, and can be 30 μm or less, preferably 20 μm or less, more preferably 15 μm or less.

The spherical hydrophobic silica aerogel may be present in an amount of 0.05% by weight or more, preferably 0.1% by weight or more, more preferably 0.3% by weight or more, and most preferably 0.5% by weight or more, and 15% by weight or less, preferably 10% by weight or less, more preferably 5% by weight or less, and most preferably 2% by weight or less, based on the total weight of the composition.

The composite silica particles may be metal silica-containing silica particles, preferably titanium dioxide-containing silica particles.

The composite silica particles may be present in an amount of 0.01% by weight or more, preferably 0.5% by weight or more, more preferably 1% by weight or more, and most preferably 2% by weight or more, and 10% by weight or less, preferably 7% by weight or less, more preferably 5% by weight or less, and most preferably 4% by weight or less, based on the total weight of the composition.

The hollow silica particles may be present in an amount of 0.01% by weight or more, preferably 0.5% by weight or more, more preferably 1% by weight or more, and most preferably 2% by weight or more, and 10% by weight or less, preferably 7% by weight or less, more preferably 5% by weight or less, and most preferably 4% by weight or less, based on the total weight of the composition.

The composition according to the present invention may contain either composite silica particles or hollow silica particles.

The composition according to the present invention may be in the form of a W/O type emulsion.

The cosmetic composition according to the present invention may be a skin makeup composition, preferably a foundation.

The present invention also relates to a method for preparing a cosmetic composition in the form of a W/O emulsion, comprising the steps of:
- mixing an oily component comprising at least one kind of spherical hydrophobic silica aerogel and at least one kind of composite silica particles and/or at least one kind of hollow silica particles to prepare an oily phase;
- preparing an aqueous phase;
- adding or pouring the aqueous phase into the oily phase while stirring the oily phase.

The present invention also relates to a cosmetic method for keratinous materials such as skin, comprising the step of applying a cosmetic composition according to the present invention to the keratinous material.

After extensive research, the inventors have discovered that by combining spherical hydrophobic silica aerogel with composite silica particles and/or hollow silica particles, it is possible to maintain the composition unclear or opaque even long after the composition has been applied to the skin (i.e., even under moist conditions caused by sweat or sebum).

Thus, one aspect of the present invention is a cosmetic composition comprising (i) at least one type of spherical hydrophobic silica aerogel and (ii) at least one type of composite silica particle and/or at least one type of hollow silica particle.

The composition according to the present invention is described in more detail below.

[Hydrophobic spherical silica aerogel]
The composition according to the invention comprises at least one spherical hydrophobic silica aerogel.

Aerogel is a highly porous material. In this specification, silica aerogel generally refers to solid silica having a porous structure obtained by drying wet silica gel while maintaining the solid silica network structure, thereby replacing the medium contained in the wet silica gel with air. Porosity is the amount of air contained in the apparent volume of the material, expressed as a volume percentage. The spherical hydrophobic silica aerogel of the present invention may have a porosity of 60% or more, preferably 70% or more, and more preferably 80% or more.

The hydrophobic silica aerogel of the present invention is characterized in that each particle has a spherical shape. Due to this spherical shape, the hydrophobic silica aerogel can impart good smoothness to the cosmetic composition. The sphericity of the hydrophobic silica aerogel can be determined by the average circularity.

The spherical hydrophobic silica aerogel of the present invention may have an average circularity of 0.8 or more, preferably 0.82 or more. The spherical hydrophobic silica aerogel may have an average circularity of less than 1, preferably 0.99 or less, more preferably 0.98 or less, even more preferably 0.97 or less, even more preferably 0.96 or less, and most preferably 0.95 or less.

"Average circularity" can be determined by image analysis methods. In particular, "average circularity" can be the arithmetic mean of circularity obtained by image analysis of scanning electron microscope (SEM) photographs of 2000 or more aerogel particles observed at 1000x magnification by secondary electron detection using a scanning electron microscope (SEM).

The "roundness" of each aerogel particle is calculated according to the following formula:
C=4πS/L ²
[wherein C represents the circularity, S represents the area (projected area) of the aerogel particle in the image, and L represents the perimeter (outer perimeter) of the aerogel particle in the image]
As the average circularity approaches 1, the shape of each particle becomes more spherical.

In the spherical hydrophobic silica aerogel of the present invention, the term "hydrophobic" means that the silica aerogel particles are difficult to disperse in water. More specifically, this term means that after placing 1 g of silica aerogel particles and 100 g of ion-exchanged water in a bottle, stirring or agitating the bottle for 10 seconds or more, and allowing the bottle to stand, the aerogel phase and the aqueous phase are completely separated. Thus, in a particular embodiment of the present invention, the spherical hydrophobic silica aerogel does not exhibit water absorption.

The spherical hydrophobic silica aerogel that can be used according to the present invention is preferably of the silylated silica type (INCI name: Silica silylate). Most preferably, the spherical hydrophobic silica aerogel may be one described in JP-A-2014-088307, JP-A-2014-218433, or JP-A-2018-177620.

The hydrophobicity is achieved by adding a hydrophobizing agent having the following formula present on the surface of the silica:
≡Si-OH
(wherein the symbol "≡" represents the remaining valence of 3 on the Si atom)
whereby the silanol group is converted to the following formula:
(≡Si-O-) _(4-n) SiR _n
(wherein n is an integer from 1 to 3, each R is independently a hydrocarbyl group, and two or more R may be the same or different, and n is 2 or greater.)
can be obtained by converting the group represented by the formula:

The hydrophobizing agent may be a silylation agent. Thus, according to a preferred embodiment, in the spherical hydrophobic silica aerogel, the silica particles may be surface-modified by silylation. Examples of silylation agents include treatment agents having one of the following formulae (1) to (3):

Equation (1):
R _n SiX _(4-n)
[wherein n represents an integer from 1 to 3, R represents a hydrocarbyl group, X represents a group that can be eliminated from the molecule by cleaving the bond to the Si atom during reaction with a compound having a hydroxyl group (i.e., a leaving group), each R may be different, where n is 2 or more, and each X may be different, where n is 2 or less].

Formula (2):

[In the formula, ^R1 represents an alkylene group, ^R2 and ^R3 independently represent a hydrocarbyl group, and ^R4 and ^R5 independently represent a hydrogen atom or a hydrocarbyl group].

Equation (3):

[In the formula, R ⁶ and R ⁷ independently represent a hydrocarbyl group, m represents an integer from 3 to 6, and when there are two or more R ^6s , each R ⁶ may be different, and when there are two or more R ^7s , each R ⁷ may be different].

In the above formula (1), R is a hydrocarbyl group, preferably a hydrocarbyl group having 1 to 10 carbon atoms, more preferably a hydrocarbyl group having 1 to 4 carbon atoms, and particularly preferably a methyl group.

Examples of the leaving group represented by X include halogen atoms such as chlorine and bromine, alkoxy groups such as methoxy and ethoxy, and groups represented by -NH- _SiR3 (wherein R is defined the same as R in formula (1)).

Specific examples of hydrophobizing agents represented by the above formula (1) include chlorotrimethylsilane, dichlorodimethylsilane, trichloromethylsilane, monomethyltrimethoxysilane, monomethyltriethoxysilane, and hexamethyldisilazane.

Most preferably, in view of favorable reactivity, chlorotrimethylsilane, dichlorodimethylsilane, trichloromethylsilane, and/or hexamethyldisilazane may be used.

The number of bonds between the Si atom and the silanol groups on the silica backbone varies depending on the number of leaving groups X (4-n). For example, when n is 2, the following bonds are formed:
(≡Si _- O-) _2SiR2

When n is 3, the following combination occurs:
≡Si-O- _SiR3

In this way, the silanol groups can be silylated, thereby rendering them hydrophobic.

In the above formula (2), R ¹ may be an alkylene group, preferably an alkylene group having 2 to 8 carbon atoms, and particularly preferably an alkylene group having 2 to 3 carbon atoms.

In the above formula (2), ^R2 and ^R3 are independently a hydrocarbyl group, and the same preferred groups as R in formula (1) can be mentioned. ^R4 represents a hydrogen atom or a hydrocarbyl group, and when it is a hydrocarbyl group, the same preferred groups as R in formula (1) can be mentioned. When silica gel is treated with a compound represented by formula (2) (cyclic silazane), the reaction with the silanol group causes the cleavage of the Si-N bond, and thus the following bond is formed on the surface of the silica skeleton in the gel:
(≡Si ^{- O-} ) _2SiR2R3

In this manner, the silanol groups can also be silylated with the cyclic silazane of formula (2) above, thereby achieving hydrophobization.

Specific examples of cyclic silazanes represented by the above formula (3) include hexamethylcyclotrisilazane and octamethylcyclotetrasilazane.

In the above formula (3), ^R6 and ^R7 are independently a hydrocarbyl group, and the preferred groups are the same as those of R in formula (2). m represents an integer of 3 to 6. When silica gel is treated with a compound represented by formula (3) (cyclic siloxane), the following bonds are formed on the surface of the silica skeleton in the gel:
(≡Si ^{- O-} ) _2SiR6R7

In this manner, the silanol groups can also be silylated with the cyclic siloxane of formula (3) above, thereby achieving hydrophobization.

Specific examples of cyclic siloxanes represented by the above formula (3) include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, and decamethylcyclopentasiloxane.

Spherical hydrophobic silica aerogels can be prepared by producing a silica sol, converting the sol to a gel, aging the gel, washing the aged gel, replacing the water in the washed gel with a solvent, treating the gel with a hydrophobizing agent, and drying the hydrophobized silica.

The specific surface area of the spherical hydrophobic silica aerogel, determined by the BET method, can be 200 m ² /g or more, preferably 400 m ² /g or more, more preferably 500 m ² /g or more, and can be 1200 m ² /g or less, preferably 1000 m ² /g or less, more preferably 800 m ² /g or less.

In the present invention, the "specific surface area determined by the BET method" means a value determined by drying a measurement sample at 200°C for 3 hours or more under reduced pressure of 1 kPa or less, measuring the adsorption isotherm only on the nitrogen adsorption side at liquid nitrogen temperature, and analyzing the adsorption isotherm by the BET method. The pressure range used for the analysis is a relative stress of 0.1 to 0.25.

The pore volume of the spherical hydrophobic silica aerogel, as determined by the BJH method, may be 1 ml/g or more, preferably 2 ml/g or more, more preferably 3 ml/g or more, and 10 ml/g or less, preferably 8 ml/g or less, more preferably 7 ml/g or less. The peak pore radius of the spherical hydrophobic silica aerogel, as determined by the BJH method, may be 5 nm or more, preferably 10 nm or more, more preferably 12 nm or more, and 50 nm or less, preferably 40 nm or less, more preferably 30 nm or less.

"Pore volume determined by the BJH method" refers to the pore volume derived from pores with a pore radius of 1 nm to 100 nm obtained by analyzing the adsorption isotherm on the nitrogen adsorption side obtained by the same method as described above in "Specific surface area determined by the BET method" by the BJH method (Barrett, E. P.; Joyner, L. G.; Halenda, P. P., J. Am. Chem. Soc. 73, 373 (1951)). "Peak pore radius determined by the BJH method" refers to the value of the pore radius that produces a peak in the pore distribution curve (volume distribution curve) plotted on the ordinate and the abscissa, respectively, of the differential of the cumulative pore volume with respect to the logarithm of the pore radius obtained by analyzing the adsorption isotherm on the nitrogen adsorption side obtained by the BJH method in the same manner as above.

The average particle size of the spherical hydrophobic silica aerogel may be 0.5 μm or more, preferably 1 μm or more, more preferably 2 μm or more, and may have an average particle size measured by image analysis of 30 μm or less, preferably 20 μm or less, more preferably 15 μm or less.

The "average particle size" here can be measured by image analysis. In particular, the value of "average particle size" is the arithmetic mean of the equivalent circular diameters that can be obtained, for example, by image analysis of a scanning electron microscope (SEM) photograph of 2000 or more aerogel particles observed at 1000x magnification by secondary electron detection using a SEM. The "equivalent circular diameter" of each aerogel particle is the diameter of a circle having an area equal to the area (projected area) of the aerogel particle in the image.

Preferably, the oil absorption capacity of the spherical hydrophobic silica aerogel, which can be measured at the wet point, is 2 ml/g or more, preferably 3 ml/g or more, more preferably 4 ml/g or more, and most preferably 5 ml/g or more, and may be 12 ml/g or less, preferably 11 ml/g or less, more preferably 10 ml/g or less, and most preferably 8 ml/g or less.

The oil absorption capacity measured at the wet point is denoted Wp and corresponds to the amount of oil that must be added to 100 g of particles to obtain a homogeneous paste. It can be measured according to the wet point method or the method for determining the oil uptake of powders described in standard NF T 30-022. The oil uptake may correspond to the amount of oil adsorbed on the available surface of the powder and/or absorbed by the powder by measuring the wet point as described below.

An amount of m=2 g of powder is placed on a glass plate and then oil (ester oil, oleic acid, silicone oil, etc.) is added dropwise. After 4-5 drops of oil have been added to the powder, a spatula is used to mix and the addition of oil is continued until an agglomerate of oil and powder is formed. At this point, oil is added drop by drop and then the mixture is ground with the spatula. When a stiff and smooth paste is obtained, the addition of oil is stopped. This paste should be able to be spread on the glass plate without cracking or forming lumps. The volume Vs of the oil used (expressed in ml) is then noted. The oil uptake corresponds to the ratio Vs/m.

Alternatively, oil absorption capacity can be measured according to JIS-K6217-4.

In a preferred embodiment of the present invention, (a) the spherical hydrophobic silica aerogel is one described in JP-A-2014-088307, JP-A-2014-218433, or JP-A-2018-177620.

The spherical hydrophobic silica aerogel may be present in an amount of 0.05% by weight or more, preferably 0.1% by weight or more, more preferably 0.3% by weight or more, and most preferably 0.5% by weight or more, and 15% by weight or less, preferably 10% by weight or less, more preferably 5% by weight or less, and most preferably 2% by weight or less, based on the total weight of the composition.

[Composite Silica Particles]
The composition according to the present invention may comprise at least one composite silica particle.

In the context of the present invention, the term "composite silica particles" refers to silica particles in which a functional compound, preferably a metal oxide, is included. Thus, preferably, composite silica particles may be referred to as "metal oxide-containing silica particles". Most preferably, the metal oxide is dispersed in the silica particles.

The metal oxide may preferably be selected from titanium dioxide, zinc oxide, iron oxide, and zirconium oxide, or mixtures thereof, more particularly from titanium dioxide (TiO ₂ ) and zinc oxide, and mixtures thereof. Particularly preferably, titanium dioxide can be used.

The composite silica particles may have an average particle size determined by image analysis of 0.1 μm or more, preferably 0.5 μm or more, more preferably 1 μm or more, and 50 μm or less, preferably 20 μm or less, more preferably 10 μm or less.

"Average particle size" can be determined according to the following procedure: The particle sizes of 50 particles are measured using SEM images and the average particle size is calculated.

The composite silica particles may be porous or non-porous and may have low oil absorption capacity.

In the composite silica particles, the weight ratio of silica to functional compound (preferably a metal oxide, most preferably titanium dioxide) may be from 9:1 to 5:5, preferably from 4:1 to 3:2, more preferably 7:3.

The composite silica particles may be surface treated to render them hydrophobic. For example, the composite silica particles may be surface treated with an alkylsilane.

Most preferably, CHIFONSIL-5T sold by JGC Catalysts and Chemicals may be used as the composite silica particles.

The composite silica particles may be present in an amount of 0.01% by weight or more, preferably 0.5% by weight or more, more preferably 1% by weight or more, and most preferably 2% by weight or more, based on the total weight of the composition. The composite silica particles may be present in an amount of 10% by weight or less, preferably 7% by weight or less, more preferably 5% by weight or less, and most preferably 4% by weight or less, based on the total weight of the composition.

[Hollow silica particles]
The composition according to the invention may comprise at least one hollow silica particle.

In the context of the present invention, the term "hollow silica particles" means silica particles that have a hollow cavity space inside them.

The hollow silica particles may have an average particle size, as determined by image analysis, of 0.1 μm or more, preferably 0.5 μm or more, more preferably 1 μm or more, and 50 μm or less, preferably 20 μm or less, more preferably 12 μm or less.

"Average particle size" can be determined according to the following procedure: The particle sizes of 100 particles are measured using a scanning electron microscope (SEM). The "average particle size" is determined by averaging the measured particle sizes.

The hollow silica particles may be porous or non-porous. Preferably, the hollow silica particles may be non-porous.

Preferably, the oil absorption capacity of the hollow silica particles may be low. Preferably, the oil absorption capacity of the hollow silica particles measured at the wet point may be less than 2 ml/g, preferably less than 1 ml/g, more preferably less than 0.7 ml/g, and may be greater than 0.01 ml/g, preferably greater than 0.05 ml/g, more preferably greater than 0.1 ml/g. The oil absorption capacity measured at the wet point may be determined according to the same method as described in the "Spherical hydrophobic silica aerogel" section above.

Most preferably, BA4 sold by JGC Catalysts and Chemicals may be used as the hollow silica particles.

The hollow silica particles may be present in an amount of 0.01% by weight or more, preferably 0.5% by weight or more, more preferably 1% by weight or more, and most preferably 2% by weight or more, based on the total weight of the composition. The hollow silica particles may be present in an amount of 10% by weight or less, preferably 7% by weight or less, more preferably 5% by weight or less, and most preferably 4% by weight or less, based on the total weight of the composition.

[Composition]
The composition according to the present invention may be in any form, such as a dispersion, emulsion, gel, and paste. Preferably, the composition according to the present invention may be in the form of an emulsion, such as W/O, O/W, W/O/W, and O/W/O type. Most preferably, the composition according to the present invention may be in the form of a W/O type emulsion.

The term "W/O emulsion" or "water-in-oil emulsion" means any macroscopically homogeneous composition comprising a continuous fatty or oily phase and an aqueous or water phase in the form of droplets dispersed in said fatty or oily phase.

In one embodiment, the composition of the present invention in the form of a W/O type emulsion can be prepared according to the following protocol: (1) prepare an oily phase by mixing an oily component including a spherical hydrophobic silica aerogel and composite silica particles and/or hollow silica particles, (2) prepare an aqueous phase, and (3) add or pour the aqueous phase into the oily phase while stirring the oily phase.

I. Oily Phase The compositions of the present invention may comprise at least one oil.

For the purposes of the present invention, the term "oil" means a fatty substance that is in liquid form at room temperature and atmospheric pressure.

The oily phase suitable for the preparation of the compositions according to the invention may comprise oils of vegetable or animal origin, synthetic oils, hydrocarbon oils, fatty alcohols and silicone oils, as well as mixtures thereof.

Examples of vegetable oils include, for example, hydrocarbon-based oils of vegetable origin, such as phytostearyl esters, such as phytostearyl oleate, phytostearyl isostearate and lauroyl/octyldodecyl/phytostearyl glutamate (Ajinomoto, Eldew PS203), triglycerides formed from fatty acid esters of glycerol, in particular those in which the fatty acids are _C4 to _C36 , especially _C18 to C39, These oils may have a chain length ranging from 0.1 to ₃₆ , and are optionally linear or branched and saturated or unsaturated, and include, among others, heptanoic or octanoic triglycerides, shea oil, alfalfa oil, poppy seed oil, winter squash oil, millet oil, barley oil, quinoa oil, rye oil, kukui oil, passionflower oil, shea butter, aloe vera oil, sweet almond oil, peach seed oil, peanut oil, argan oil, avocado oil, and the like. oleic acid, baobab oil, borage oil, broccoli oil, calendula oil, camelina oil, canola oil, carrot oil, safflower oil, flax oil, rapeseed oil, cottonseed oil, palm oil, mallow seed oil, wheat germ oil, jojoba oil, lily oil, macadamia oil, corn oil, meadowfoam oil, St. John's wort oil, monoi oil, hazelnut oil, apricot seed oil, walnut oil, olive oil, oenothera biennis biennis oil, palm oil, blackcurrant root oil, kiwi fruit seed oil, grape seed oil, pistachio oil, winter squash oil, pumpkin oil, quinoa oil, musk rose oil, sesame oil, soybean oil, sunflower oil, castor oil and watermelon oil, as well as mixtures thereof, or caprylic/capric triglycerides, such as those sold by the company Stearineries Dubois or those sold by the company Dynamit Nobel under the names Miglyol 810®, 812® and 818®. Mention may also be made of modified vegetable oils, such as activated palm oil, such as those sold by the company Biotropics under the names Scalpro or Acnaed.

Examples of animal oils include squalene and squalane.

Examples of synthetic oils include alkane oils such as isododecane and isohexadecane, ester oils, ether oils, and artificial triglycerides.

The ester oil is preferably a liquid ester of a saturated or unsaturated, linear or branched _C1 - _C26 aliphatic mono- or polyacid and a saturated or unsaturated, linear or branched _C1 - _C26 aliphatic mono- or polyhydric alcohol, the total number of carbon atoms in the ester preferably being 10 or more and preferably 30 or less.

Preferably, the ester oil may be a liquid ester of a saturated or unsaturated linear or branched _C2 - _C20 aliphatic polyacid and a saturated or unsaturated linear or branched _C2 - _C20 aliphatic monohydric alcohol. More preferably, the ester oil may be a liquid ester of a saturated linear _C5 - _C15 aliphatic diacid and a saturated branched _C2 - _C5 aliphatic monohydric alcohol.

In one embodiment, in the case of esters of monohydric alcohols, at least one of the alcohol and acid from which the esters of the invention are derived may be branched.

Among the monoesters of monoacids and monohydric alcohols, mention may be made of ethyl palmitate, ethylhexyl palmitate, isopropyl palmitate, dicaprylyl carbonate, alkyl myristates, such as isopropyl myristate or ethyl myristate, isocetyl stearate, 2-ethylhexyl isononanoate, isononyl isononanoate, isodecyl neopentanoate and isostearyl neopentanoate.

Esters of C ₄ to C ₂₂ di- or tricarboxylic acids with C ₁ to C ₂₂ alcohols, and esters of mono-, di- or tricarboxylic acids with non-sugar C ₄ to C ₂₆ dihydroxy, trihydroxy, tetrahydroxy or pentahydroxy alcohols may also be used.

In particular, there may be mentioned diethyl sebacate, isopropyl lauroyl sarcosinate, diisopropyl sebacate, bis(2-ethylhexyl) sebacate, diisopropyl adipate, di-n-propyl adipate, dioctyl adipate, bis(2-ethylhexyl) adipate, diisostearyl adipate, bis(2-ethylhexyl) maleate, triisopropyl citrate, triisocetyl citrate, triisostearyl citrate, glyceryl trilactate, glyceryl trioctanoate, trioctyldodecyl citrate, trioleyl citrate, neopentyl glycol diheptanoate, diethylene glycol diisononanoate, and preferably diisopropyl sebacate.

As ester oils, sugar esters and diesters of _C6 - _C30 , preferably _C12 - _C22 , fatty acids can be used. The term "sugar" is recalled to mean oxygen-containing hydrocarbon-based compounds containing several alcohol functions, with or without aldehyde or ketone functions, and containing at least 4 carbon atoms. These sugars can be monosaccharides, oligosaccharides or polysaccharides.

Examples of suitable sugars that may be mentioned are sucrose (or sucrose), glucose, galactose, ribose, fucose, maltose, fructose, mannose, arabinose, xylose and lactose, as well as their derivatives, especially alkyl derivatives, such as methyl derivatives, for example methylglucose.

The sugar esters of fatty acids may in particular be chosen from the group comprising the esters or mixtures of esters of the aforementioned sugars with linear or branched, saturated or unsaturated C ₆ -C ₃₀ , preferably C ₁₂ -C ₂₂ fatty acids. These compounds, when unsaturated, may have from 1 to 3 conjugated or non-conjugated carbon-carbon double bonds.

The esters according to this variant can also be selected from monoesters, diesters, triesters, tetraesters and polyesters, and mixtures thereof.

These esters may be, for example, oleic acid esters, lauric acid esters, palmitic acid esters, myristic acid esters, behenic acid esters, coconut acid esters, stearic acid esters, linoleic acid esters, linolenic acid esters, capric acid esters and arachidonic acid esters, or mixtures thereof, such as, inter alia, mixed esters of oleopalmitic acid, oleostearic acid and palmitostearic acid, and pentaerythrityl tetraethylhexanoate.

More particularly, mono- and diesters are used, in particular the mono- or dioleate, stearates, behenates, oleopalmitates, linoleates, linolenates and oleostearates of sucrose, glucose or methylglucose.

An example that may be mentioned is the product sold under the name Glucate® DO by the company Amerchol, which is a methylglucose dioleate.

Examples of preferred ester oils include, for example, diisopropyl adipate, dioctyl adipate, 2-ethylhexyl hexanoate, ethyl laurate, cetyl octanoate, octyldodecyl octanoate, isodecyl neopentanoate, myristyl propionate, 2-ethylhexyl 2-ethylhexanoate, 2-ethylhexyl octanoate, 2-ethylhexyl caprylate/caprate, methyl palmitate, ethyl palmitate, isopropyl palmitate, dicaprylate carbonate, ethyl oleate ... Examples of the glyceryl esters include glyceryl esters, isopropyl lauroyl sarcosine, isononyl isononanoate, ethylhexyl palmitate, isohexyl laurate, hexyl laurate, isocetyl stearate, isopropyl isostearate, isopropyl myristate, isodecyl oleate, glyceryl tri(2-ethylhexanoate), pentaerythrityl tetra(2-ethylhexanoate), 2-ethylhexyl succinate, diethyl sebacate, and mixtures thereof.

Examples of artificial triglycerides include capryl caprylyl glyceride, glyceryl trimyristate, glyceryl tripalmitate, glyceryl trilinolenate, glyceryl trilaurate, glyceryl tricaprate, glyceryl tricaprylate, tri(capric/caprylic)glyceryl, and tri(capric/caprylic/linolenic)glyceryl.

The hydrocarbon oil may be selected from:
- linear or branched, optionally cyclic, lower alkanes _C6 to _C16 , examples which may be mentioned being hexane, undecane, dodecane, tridecane and isoparaffins, such as isohexadecane, isododecane and isodecane;
- linear or branched hydrocarbons containing more than 16 carbon atoms, such as liquid paraffin, liquid petrolatum, polydecenes and hydrogenated polyisobutenes, such as Parleam®, and squalane.

Examples of hydrocarbon oils include, for example, linear or branched hydrocarbons such as isohexadecane, isododecane, squalane, mineral oils (e.g., liquid paraffin), paraffin, petrolatum or petrolatum, naphthalene, etc., hydrogenated polyisobutene, isoeicosane and decene/butene copolymers, and mixtures thereof.

The term "fatty" in fatty alcohols means to include a relatively large number of carbon atoms. Thus, alcohols having 4 or more, preferably 6 or more, and more preferably 12 or more carbon atoms are included within the scope of fatty alcohols. Fatty alcohols may be saturated or unsaturated. Fatty alcohols may be linear or branched.

The fatty alcohol may have the structure R-OH, where R is selected from saturated and unsaturated, straight and branched groups containing from 4 to 40 carbon atoms, preferably from 6 to ₃₀ carbon atoms, and more preferably from 12 to ₂₀ carbon atoms. In at least one embodiment, R may be selected from _C12 -C20 alkyl groups and _C12 -C20 alkenyl groups. R may or may not be substituted with at least one hydroxyl group.

Examples of fatty alcohols include lauryl alcohol, cetyl alcohol, stearyl alcohol, isostearyl alcohol, behenyl alcohol, undecylenyl alcohol, myristyl alcohol, octyldodecanol, hexyldecanol, oleyl alcohol, linoleyl alcohol, palmitoleyl alcohol, arachidonyl alcohol, erucyl alcohol, and mixtures thereof.

Thus, the fatty alcohol may be selected from linear or branched, saturated or unsaturated _C6 - _C30 alcohols, preferably linear or branched, saturated _C6 - _C30 alcohols, more preferably linear or branched, saturated _C12 - _C20 alcohols.

The term "saturated fatty alcohol" as used herein means an alcohol with a long aliphatic saturated carbon chain. It is preferred that the saturated fatty alcohol is selected from any linear or branched saturated _C6 - _C30 fatty alcohol. Among the linear or branched saturated _C6 - _C30 fatty alcohols, linear or branched saturated _C12 - _C20 fatty alcohols may preferably be used. Any linear or branched saturated _C16 - _C20 fatty alcohol may more preferably be used. Branched _C16 - _C20 fatty alcohols may even more preferably be used.

Examples of saturated fatty alcohols include lauryl alcohol, cetyl alcohol, stearyl alcohol, isostearyl alcohol, behenyl alcohol, undecylenyl alcohol, myristyl alcohol, octyldodecanol, hexyldecanol, and mixtures thereof. In one embodiment, cetyl alcohol, stearyl alcohol, octyldodecanol, hexyldecanol, or mixtures thereof (e.g., cetearyl alcohol) and behenyl alcohol can be used as the saturated fatty alcohol.

Examples of silicone oils include linear organopolysiloxanes such as dimethylpolysiloxane (dimethicone), methylphenylpolysiloxane, methylhydrogenpolysiloxane, etc., cyclic organopolysiloxanes such as octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, etc., and mixtures thereof.

The oil may be present in the composition in an amount of 10% by weight or more, preferably 15% by weight or more, more preferably 17% by weight or more, even more preferably 20% by weight or more, and in an amount of 40% by weight or less, preferably 35% by weight or less, more preferably 30% by weight or less, based on the total weight of the composition.

II. Aqueous Phase The aqueous phase of the compositions according to the present invention comprises at least one aqueous medium, namely water and optionally a water-soluble solvent.

In the present invention, the term "water-soluble solvent" refers to a compound that is liquid at room temperature and is miscible with water (miscible with more than 50% by weight of water at 25°C and atmospheric pressure).

The water-soluble solvents that may be used in the compositions of the present invention may be volatile.

Among the water-soluble solvents that may be used in the compositions according to the invention, mention may be made in particular of alcohols, such as lower monohydric alcohols containing from 1 to 5 carbon atoms, such as ethanol and isopropanol, glycols containing from 2 to 8 carbon atoms, such as ethylene glycol, propylene glycol, 1,3-butylene glycol and dipropylene glycol, _C3 and _C4 ketones, and _C2 to _C4 aldehydes.

According to another embodiment variant, the aqueous phase of the composition according to the invention may comprise at least one C ₂ to C ₃₂ polyol.

For the purposes of the present invention, the term "polyol" should be understood to mean any organic molecule containing at least two free hydroxyl groups. Preferably, the polyol according to the invention is in liquid form at room temperature.

The polyols suitable for use in the present invention may be linear, branched or cyclic, saturated or unsaturated alkyl type compounds carrying at least two -OH functional groups in the alkyl chain, in particular at least three -OH functional groups, more particularly at least four -OH functional groups. The polyols advantageously suitable for formulating the compositions according to the invention are in particular those exhibiting from 2 to 32 carbon atoms, preferably from 3 to 16 carbon atoms. Advantageously, the polyols may be chosen, for example, from ethylene glycol, pentaerythritol, trimethylolpropane, propylene glycol, 1,3-propanediol, butylene glycol, isoprene glycol, pentylene glycol, hexylene glycol, glycerol (glycerin), polyglycerols, such as glycerol oligomers, such as diglycerol, and polyethylene glycol, and mixtures thereof. According to a particular embodiment, the compositions of the present invention may comprise at least glycerol.

The aqueous phase (water and optional water-miscible solvent) may be present in the composition in a content of 5% by weight or more, preferably 10% by weight or more, more preferably 25% by weight or more, and in a content of 50% by weight or less, preferably 45% by weight or less, more preferably 35% by weight or less, based on the total weight of the composition.

[Surfactants]
The composition according to the invention may comprise at least one surfactant chosen from amphoteric, anionic, cationic or nonionic surfactants, used alone or in mixtures.

Examples of anionic surfactants that can be used in the compositions of the present invention include alkyl sulfates, alkyl ether sulfates, alkyl sulfonates, alkyl ether sulfonates, sulfate esters of alkylphenoxy polyoxyethylene ethanol, α-olefin sulfonates, β-alkyloxyalkene sulfonates, alkylaryl sulfonates, alkyl carbonates, succinamates, sulfosuccinates, sarcosinates, octoxynol or nonoxynol phosphates, taurates, fatty taurides, sulfated monoglycerides, fatty acid amino polyoxyethylene sulfates, isethionates, alkylbenzene sulfonates, polyoxyethylene alkyl ether sulfates, polyoxyethylene alkyl ether carboxylic acids, and polyoxyethylene alkylamide ether carboxylic acids, and salts thereof.

Examples of nonionic surfactants which can be used in the compositions of the invention include polyethoxylated or polyglycerolated fatty alcohols, such as ethylene oxide adducts with lauryl alcohol, in particular those containing from 9 to 50 oxyethylene units (INCI names Laureth-9 to Laureth-50), in particular Laureth-9; esters of polyols with fatty acids and their oxyalkylenated derivatives, for example with a saturated or unsaturated chain containing from 8 to 24 carbon atoms, i.e. those containing oxyethylene and/or oxypropylene units, for example esters of glycerol with C ₈ to C ₂₄ fatty acids and their oxyalkylenated derivatives, in particular polyoxyethylenated glyceryl stearate (mono-, di- and/or tristearate), such as PEG-30 dipolyhydroxystearate and PEG-20 glyceryl triisostearate; esters of sugars with C ₈ to C ₂₄ fatty acids and their oxyalkylenated derivatives, such as C ₈ to C 24 fatty acids. Mention may be made of polyethoxylated sorbitol esters of ₂₄ fatty acids, in particular polysorbate 80, such as the product sold under the name "TWEEN 80" by the company Croda; ethers of sugars with _C8 to _C24 fatty alcohols, such as caprylyl/capryl glucoside; polyoxyethylene alkyl ethers; polyoxyethyleneoxypropylene alkyl ethers; fatty acid alkanolamides; alkylamine oxides; alkyl polyglycosides, and silicone surfactants, such as polydimethylsiloxanes containing oxyethylene and/or oxypropylene groups, for example PEG-10 dimethicone, bis-PEG/PPG-14/14 dimethicone, bis-PEG/PPG-20/20 dimethicone, and PEG/PPG-20/6 dimethicone.

Examples of amphoteric surfactants that can be used in the compositions of the present invention include alkanoyl amidopropyl-N,N-dimethylglycine betaine, alkanoyl amidopropyl-N,N-dimethyl-2-hydroxypropyl sulfobetaine, alkyl-N,N-dimethylglycine betaine, alkanoyl amidopropyl-N,N-dimethyl-propyl sulfobetaine, lauryl-N,N-dimethyl-2-hydroxypropyl sulfobetaine, and salts thereof.

Examples of cationic surfactants that can be used in the compositions of the present invention include _C8 - _C24 long-chain dialkyldimethylammonium salts, long-chain monoalkylmonobenzyldimethylammonium salts, and long-chain monoalkyltrimethylammonium salts, all of which may have amide or ester bonds therein, and the counterions are preferably halogen atoms such as chlorine and bromine atoms, sulfates, and alkyl group-containing sulfate residues such as methyl sulfate and ethyl sulfate, and salts thereof. Amine-type cationic surfactants include long-chain dialkylmonomethylamine salts, preferably in the form of hydrochlorides, sulfates, or phosphates, having long-chain _C8 - _C24 alkyl groups that may have amide or ester bonds therein, and salts thereof.

The surfactant may be present in the composition in an amount of 0.5% by weight or more, preferably 1% by weight or more, more preferably 1.5% by weight or more, and in an amount of 15% by weight or less, preferably 10% by weight or less, more preferably 7% by weight or less, based on the total weight of the composition.

[UV filter]
The composition according to the invention may comprise at least one UV filter.

The UV filter may be a solid or a liquid, preferably a liquid. The terms "solid" and "liquid" mean solid and liquid at 1 atm and 25°C, respectively. The UV filter may be made of at least one organic or inorganic material, preferably at least one organic material. Thus, the UV filter is preferably an organic UV filter.

The organic UV filters may be selected from the group consisting of anthranilic acid derivatives; dibenzoylmethane derivatives; cinnamic acid derivatives; salicylic acid derivatives such as homosalate (homomenthyl salicylate) and ethylhexyl salicylate; camphor derivatives; benzophenone derivatives; β,β-diphenylacrylate derivatives; triazine derivatives; benzotriazole derivatives; benzalmalonate derivatives; benzimidazole derivatives; imidazoline derivatives; bis-benzoazolyl derivatives; p-aminobenzoic acid (PABA) and its derivatives; benzoxazole derivatives; shielding polymers and shielding silicones; dimers derived from α-alkylstyrene; 4,4-diarylbutadiene; octocrylene and its derivatives, guaiazulene and its derivatives, rutin and its derivatives, flavonoids, biflavonoids, oryzanol and its derivatives, quinic acid and its derivatives, phenol, retinol, cysteine, aromatic amino acids, peptides having aromatic amino acid residues, and mixtures thereof.

The UV filter may be present in the composition in an amount of 1% by weight or more, preferably 3% by weight or more, more preferably 5% by weight or more, and in an amount of 20% by weight or less, preferably 15% by weight or less, more preferably 10% by weight or less, based on the total weight of the composition.

[Colorings or pigments]
The compositions according to the invention may include at least one colorant or pigment to impart a desired color or effect.

Examples of colorants or pigments can include inorganic pigments, organic pigments, and/or lakes.

Examples of inorganic pigments include metal oxides and metal hydroxides such as magnesium oxide, magnesium hydroxide, calcium oxide, calcium hydroxide, aluminum oxide _, aluminum hydroxide, iron oxide (α- _Fe2O3 , γ- _Fe2O3 , _Fe3O4 , _FeO ), red iron oxide, yellow iron oxide, black iron oxide, iron hydroxide, titanium dioxide, lower titanium oxide, zirconium oxide, chromium _oxide , chromium hydroxide, manganese oxide, cobalt oxide, cerium oxide, nickel oxide, and zinc oxide, as well as complex oxides and complex hydroxides such as iron titanate, cobalt titanate, and cobalt aluminate. Suitable inorganic pigments also include non-metal oxides such as alumina and silica, ultramarine blue (i.e., sulfur-containing sodium aluminum silicate), Prussian blue, manganese violet, bismuth oxychloride, talc, mica, sericite, magnesium carbonate, calcium carbonate, magnesium silicate, magnesium aluminum silicate, silica, titanium mica, iron oxide titanium mica, bismuth oxychloride, and the like.

Examples of organic pigments include carbon black, carmine, phthalocyanine blues and greens, diarylide yellow and orange dyes, and azo-type reds and yellows (such as toluidine red, litho red, naphthol red and brown dyes), and combinations thereof.

"Lake" generally refers to a colorant prepared from a water-soluble organic dye (e.g., D&C or FD&C) deposited on an insoluble reactive or adsorptive substrate or diluent. The term "D&C" as used herein means a drug and cosmetic colorant approved by the FDA for use in drugs and cosmetics. The term "FD&C" as used herein means a food, drug, and cosmetic colorant approved by the FDA for use in foods, drugs, and cosmetics. Substrates suitable for forming the lake include, but are not limited to, mica, bismuth oxychloride, sericite, alumina, aluminum, copper, bronze, silver, calcium, zirconium, barium, and strontium, titanium mica, fumed silica, spherical silica, polymethylmethacrylate (PMMA), micronized Teflon, boron nitride, acrylate copolymers, aluminum silicate, aluminum starch octenylsuccinate, bentonite, calcium silicate, cellulose, chalk, corn starch, diatomaceous earth, Fuller's earth, glyceryl denite, and the like. Examples of such materials include corn, hectorite, hydrated silica, kaolin, magnesium aluminum silicate, magnesium trisilicate, maltodextrin, montmorillonite, microcrystalline cellulose, rice starch, silica, talc, mica, titanium dioxide, zinc laurate, zinc myristate, zinc rosinate, alumina, attapulgite, calcium carbonate, calcium silicate, dextran, nylon, silica silylate, silk paldar, sericite, soy flour, tin oxide, titanium hydroxide, trimagnesium phosphate, Japanese walnut kernel, and mixtures thereof.

Colorants or pigments may be surface treated, for example, to render them more hydrophobic or more dispersible in the vehicle. Surface treatment compounds may include hydrophobic moieties selected from, for example, alkyl, aryl, allyl, vinyl, alkyl-aryl, aryl-alkyl, organosilicone, di-organosilicone, dimethicone, methicone, polyurethane, silicone-polyurethane, and fluoro or perfluoro derivatives thereof. Other hydrophobic modifiers may include lauroyl lysine, isopropyl titanium triisostearate (ITT), ITT and dimethicone (ITT/dimethicone) crosspolymer, ITT and amino acids, ITT/triethoxycaprylylsilane crosspolymer, waxes (e.g., carnauba), fatty acids (e.g., stearates), HDI/trimethylol hexyllactone crosspolymer, PEG-8 methyl ether triethoxysilane, aloe, jojoba esters, lecithin, perfluoroalcohol phosphates, and magnesium myristate (MM).

Interference or pearlescent pigments may be included in the composition according to the invention. Interference or pearlescent pigments may typically be formed of mica layered with a film of about 50-300 nm of TiO ₂ , Fe ₂ O ₃ , or Cr ₂ O ₃ . Interference or pearlescent pigments may include white pearlescent materials such as mica coated with titanium oxide or with bismuth oxychloride, and colored pearlescent materials such as titanium mica with iron oxide, titanium mica with ferric blue or chromium oxide, titanium mica with organic pigments of the above types.

Preferably, the composition according to the present invention may contain "titanium dioxide (and) alumina (and) isopropyl titanium triisostearate", "iron oxide (and) isopropyl titanium triisostearate", and/or "titanium dioxide (and) aluminum hydroxide (and) dimethicone (and) hydrogen dimethicone".

The colorant or pigment may be present in the composition in an amount of 1% by weight or more, preferably 5% by weight or more, more preferably 10% by weight or more, and up to 25% by weight, preferably less than 20% by weight, more preferably up to 15% by weight, based on the total weight of the composition.

[Additives]
The composition according to the invention may also comprise any other optional additives commonly used in the cosmetic field, for example selected from fillers such as magnesium sulfate, dyes, resins, dispersants, antioxidants, preservatives such as phenoxyethanol, fragrances, neutralizing agents, pH adjusters, disinfectants, other cosmetic active agents such as vitamins, moisturizers, emollients or collagen protectants, and mixtures thereof.

In particular, the composition according to the invention may comprise a film-forming agent, such as a film-forming silicone resin, for example trimethylsiloxysilicate, and also a thickener, such as a hydrophilic thickener, for example a hectorite modified with a _C10 - _C22 fatty acid ammonium chloride, in particular a hectorite modified with distearyldimethylammonium chloride (disteardimonium hectorite).

Furthermore, in addition to the spherical hydrophobic silica aerogel, the composition according to the invention may contain additional oil-absorbing particles. Examples of oil-absorbing particles include cellulose, silica, silicates, perlite, boron nitride, magnesium carbonate, magnesium hydroxide, hydrophobic silica, such as silicate silica, kaolin, talc, polyamide (especially nylon-6) powder, acrylic polymer powder, in particular polymethyl methacrylate powder, polymethyl methacrylate/ethylene glycol dimethacrylate powder, polyallyl methacrylate/ethylene glycol dimethacrylate powder, or ethylene glycol dimethacrylate/lauryl methacrylate copolymer powder, silicones, and mixtures thereof.

These additives and their concentrates should not alter the desired properties of the compositions of the present invention.

[Method and Use]
The composition according to the invention is intended to be used as a cosmetic composition. It may therefore be intended for application to keratinous materials, such as the skin, the scalp, the hair, mucous membranes, such as the lips and the nails, in particular the skin, such as the skin of the face.

The composition according to the present invention can be used as a skin cosmetic composition, preferably as a skin makeup composition, more preferably as a foundation.

The composition according to the invention may be used in a cosmetic method for making up keratinous materials, such as the skin, scalp, hair, mucous membranes, such as the lips and nails, in particular the skin, such as the skin of the face, which comprises the step of applying the composition according to the invention to the keratinous materials.

The present invention also relates to the use of at least one composite silica particle and/or at least one hollow silica particle in a cosmetic composition, preferably in the form of a W/O emulsion, comprising at least one spherical hydrophobic silica aerogel, to maintain the composition unclear or opaque even after a long time has elapsed since the composition was applied to the skin.

Another aspect of the present invention is composite silica particles and/or hollow silica particles for use in maintaining a cosmetic composition comprising at least one spherical hydrophobic silica aerogel in an opaque or non-transparent state even long after the composition has been applied to the skin.

The present invention will now be described in more detail with reference to examples. However, these examples should not be construed as limiting the scope of the present invention.

(Examples 1 and 2 and Comparative Examples 1 to 3)
Method for preparing the foundation compositions of the present invention and comparative examples
The ingredients of phase (A1) listed in Table 1 were mixed thoroughly at 45°C. The ingredients of phase (A2) were added to phase (A1) and completely dissolved. The ingredients of phase (A3) were added and mixed at 45°C for 5 minutes using a Moritz homogenizer at 3500 rpm. The ingredients of phase (B), (C1) and (C2) were added and mixed at 3500 rpm for 10 minutes. The mixture of ingredients of phase (D) was added and mixed at 3500 rpm at 45°C for 10 minutes. The resulting foundation composition was cooled to 25°C. Finally, the ingredients of phase (E) were added and mixed at 3000 rpm for 5 minutes to obtain a W/O type emulsion type foundation composition.

The spherical silylated silica aerogel in phase (C2) had an average primary particle size of 10 μm, an average circularity of 0.88, a BET specific surface area of 592 m ² /g, a pore volume of 4.0 ml/g determined by the BJH method, an oil absorption capacity of 6.8 mL/g measured according to JIS-K6217-4, and a peak pore radius of 20 nm determined by the BJH method.

In Table 1, all ingredients are listed on a mass percent basis as active ingredients.

evaluation
[Long-lasting pore concealment and shine reduction effects]
The foundation compositions of the present invention and the comparative example were applied to the faces of five expert panels. After 5 hours, the pore concealing effect of each foundation composition was evaluated according to the following criteria: "good" means that the pores were not visually changed, "normal" means that the pores were visually changed but within an acceptable range, and "poor" means that the pores were visually changed and the change was not acceptable. Similarly, the shine reducing effect was evaluated according to the following criteria: "good" means that the shine was not visually changed, "normal" means that the shine was visually changed but within an acceptable range, and "poor" means that the shine was visually changed and the change was not acceptable.

The results are shown in Table 1.

As shown in Table 1 above, only when the spherical hydrophobic silica aerogel was combined with hollow silica particles and/or composite silica particles (Examples 1 and 2), the foundation composition had not only a high pore concealing effect, but also a high shine reducing effect for a long period of time. This means that only the above combination can keep the foundation composition unclear or opaque for a long period of time.

Claims (7)

A foundation composition in the form of a W/O type emulsion, comprising (i) at least one type of spherical hydrophobic silica aerogel and (ii) at least one type of composite silica particle, wherein the spherical hydrophobic silica aerogel is a spherical hydrophobic aerogel of silica silylate, the composite silica particles are titanium dioxide-containing silica particles and are non-porous, the spherical hydrophobic silica aerogel is present in an amount of 0.3% by mass or more and 5% by mass or less, relative to the total mass of the composition, and the composite silica particles are present in an amount of 1% by mass or more and 5% by mass or less , relative to the total mass of the composition. The foundation composition according to claim 1, wherein the average circularity of the spherical hydrophobic silica aerogel determined by an image analysis method is 0.8 or more and less than 1. The foundation composition according to claim 1 or 2, wherein the oil absorption capacity of the spherical hydrophobic silica aerogel measured at the wet point is 2 ml/g or more and 12 ml/g or less. Spherical hydrophobic silica aerogel has the following characteristics:
a specific surface area, determined by the BET method, of greater than or equal to 200 m ² /g and less than or equal to 1200 m ² /g;
- a pore volume determined by the BJH method of ≧1 ml/g and ≦10 ml/g;
4. The foundation composition of claim 1, having at least one peak pore radius, determined by the BJH method, of greater than or equal to 5 nm and less than or equal to 50 nm. The foundation composition according to any one of claims 1 to 4, wherein the average particle size of the spherical hydrophobic silica aerogel is 0.5 μm or more and 30 μm or less. A method for preparing a foundation composition in the form of a W/O type emulsion, comprising the steps of:
- preparing an oily phase by mixing an oily component containing at least one kind of spherical hydrophobic silica aerogel and at least one kind of composite silica particles, wherein the spherical hydrophobic silica aerogel is a spherical hydrophobic aerogel of silica silylate, and the composite silica particles are titanium dioxide-containing silica particles and are non-porous ;
- preparing an aqueous phase;
- adding or pouring the aqueous phase into the oily phase while stirring the oily phase ;
The method, wherein the foundation composition comprises the spherical hydrophobic silica aerogel in an amount of 0.3% by weight or more and 5% by weight or less, based on the total weight of the composition, and the composite silica particles in an amount of 1% by weight or more and 5% by weight or less , based on the total weight of the composition. A cosmetic method for the skin, comprising the step of applying to the skin a foundation composition according to any one of claims 1 to 5 .