JP2009091289A - Anisotropic particle and method for producing the same, and cosmetic comprising anisotropic particle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide particles having excellent anisotropic properties caused by covering the surfaces of the particles of a base powder with a hydrophobic material so as to be compactly covered at local positions, and to provide a method for efficiently producing the anisotropic particles. <P>SOLUTION: The anisotropic particles are prepared by compactly covering the surfaces of the particles of the base powder at the local positions with the hydrophobic material. The anisotropic particles are prepared by a method of mixing and stirring a nonaqueous solvent phase with a material exhibiting the hydrophobicity and chemically bonding with the base powder by a condensation reaction, and subsequently adding an aqueous phase in which the base powder is dispersed to cause the condensation reaction of the material exhibiting the hydrophobicity at the interface of the nonaqueous solvent phase and the water phase and to chemically bond the base powder therewith. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to anisotropic particles, and more particularly to improving the anisotropic performance of the anisotropic particles.

  In recent years, with the rapid development of the industry, the size of nano-order size control and particle design according to applications has increased for particles used in the fields of electronics / information, biological / medical, and fine chemicals. Yes. In order to impart multi-functionality to particles, compounding of substances with different properties is generally used. In particular, so-called anisotropic particles in which a plurality of substances having different properties are present separately in one particle are unique. It is attracting attention because of its natural properties.

  One method of using anisotropic particles is a powder emulsifier. The use of powders as emulsifiers has already been carried out by Levine et al., And it has been reported that surface-treated fine hydrophobic silica stabilizes surfactant-free dispersions (eg, non-surfactant). (See Patent Document 1).

In addition, a powder having both a hydrophilic part and a hydrophobic part that has been partially treated with alkylsilane on the particle surface has been developed (see, for example, Non-Patent Document 2). In this method, silica particles with a particle size of 250-660 nm with a small amount of water added are suspended in a toluene solution containing n-octadecyltrimethoxysilane, centrifuged, and dried, so that the octadecyl group is modified on the entire particle surface. This is a technique for obtaining a semi-hydrophobic particle.
However, this hydrophobic silica is in a state where hydrophilic portions and hydrophobic portions are scattered over the entire surface of the silica particles. If a hydrophilic property is imparted to one surface of the powder particles and a hydrophobic property is imparted to the other surface, and the hydrophilic portion and the hydrophobic portion can be separated, a powder emulsifier with improved surface activity is expected. .

As a further application example of anisotropic particles, a rotating bead for electronic paper can be considered by imparting the properties of an anode on one side of the anisotropic particle and a cathode on the other side. That is, if one side of an anisotropic particle is white, the other side is black, and the charges on both spherical surfaces of the particle are different, the black-and-white orientation can be controlled when the particle is placed in an electric field, and rewritable electrons Realization of paper is realized.
In addition, anisotropic particles with the properties of an anode on one side and a cathode on the other side are used as MR fluids with an increase in viscosity that occurs when a magnetic field is applied, to car brakes, clutches, machine lubricants, etc. Application is also possible.

A surface anisotropic polymer particle is known as a specific example in which different performance is given to the surface of one side hemisphere of the particle and the surface of the other side hemisphere (see, for example, Patent Document 1). This is because the protein (for example, immunoglobulin G (human IgG)) to be modified is uniformly adsorbed on the surface of the substrate (such as a polystyrene plate), and then one side of the polymer particle is brought into contact with the protein. , Only one side of the polymer particles is modified with human IgG, and the other side has a hydrophilic surface.
However, the method for synthesizing the above-mentioned surface anisotropic polymer particles is complicated and yield is relatively low. Moreover, the substance modified on the polymer surface was sparsely present in the hemisphere portion.
Therefore, in the prior art, it was difficult to densely coat the substance to be modified on the surface of one side of the particles.
Japanese Patent No. 3567269 Colloids and Surfaces, Vol.38, 325-343 (1989) Journal of American Chemical Society, 2005, 127, 6271-6275

  The present invention has been made in view of the above circumstances, and the first problem to be solved is to provide anisotropic particles whose powder particle surfaces are locally densely coated with a hydrophobic substance. is there. A second problem is to provide an efficient production method of the anisotropic particles using a water-in-oil emulsification technique.

  As a result of intensive studies conducted by the present inventors in order to solve the above-mentioned problems, it has been found that anisotropic particles that are densely coated locally can be obtained by applying an emulsification technique, and the present invention is completed. It came to.

  That is, the first subject of the present invention is anisotropic particles characterized in that the particle surface of the base powder is densely coated locally with a hydrophobic substance.

  In the anisotropic particles, the base powder is preferably a powder that is uniformly dispersed in water.

  In the anisotropic particles, the base powder is preferably one or more selected from silicon dioxide, aluminum oxide, mica, sericite, talc, titanium oxide, and zinc oxide.

  In the anisotropic particles, it is preferable that a substance exhibiting hydrophobicity undergoes a condensation reaction and is chemically bonded to the base powder.

  In the anisotropic particles, it is preferable that the average particle diameter of the base powder is 0.01 to 100 μm.

A cosmetic comprising the anisotropic particles is provided.
Moreover, the emulsion composition which mix | blended the said anisotropic particle | grain is provided.

In addition, the second subject of the present invention is a step of mixing and stirring a non-aqueous solvent phase that is not compatible with water and a substance that expresses hydrophobicity chemically bonded by a condensation reaction with the base powder,
An aqueous phase in which the base powder is dispersed is added, and the base powder aggregates at the interface between the non-aqueous solvent phase and the aqueous phase. And a step of densely coating the anisotropic particles.

  In the method for producing anisotropic particles according to the present invention, it is preferable that the mixing ratio of the aqueous phase and the non-aqueous solvent phase is 10/90 to 70/30.

  In the said manufacturing method, it is suitable that the mixture ratio of base powder is 0.1-20% with respect to the total amount of a nonaqueous solvent phase and an aqueous phase.

In the method for producing anisotropic particles according to the present invention, the substance that is chemically bonded by the condensation reaction with the base powder and exhibits hydrophobicity is selected from substances represented by the following general formula (1): It is preferred to include seeds or two or more.
(In the formula, X is one or more hydrolyzable groups selected from the group consisting of —Cl, —OCH ₃ , and —OC ₂ H ₅ , and Y is a linear hydrocarbon having 3 to 20 carbon atoms. A substituted hydrocarbon group substituted with a group, a branched hydrocarbon group, a cyclic hydrocarbon group, or a cyano group, a hydroxyl group, a carboxyl group, an acid amide group, an imide group, a sulfone group, an amino group, or a glyceroyl group.

  In the method for producing anisotropic particles according to the present invention, the blending ratio of the substance that expresses hydrophobicity contained in the non-aqueous solvent phase is 0.1 to the total amount of the non-aqueous solvent phase and the aqueous phase. It is suitable that it is 20%.

  In the method for producing anisotropic particles according to the present invention, it is preferable that the aqueous phase contains a catalyst for a condensation reaction of a substance that exhibits hydrophobicity.

According to the present invention, since the surface of the base powder is locally densely coated with a hydrophobic substance, both the performance of the base powder itself and the hydrophobic performance can be effectively exhibited. Particles can be obtained. And this anisotropic particle can function as a powder emulsifier excellent in surface active ability, when the emulsion which mix | blended it is prepared.
Moreover, according to the method for producing anisotropic particles according to the present invention, it is possible to efficiently provide the anisotropic particles.

Hereinafter, embodiments of the present invention will be described in more detail.
Base powder The base powder used in producing the anisotropic particles according to the present invention is not particularly limited as long as it is a powder that is uniformly dispersed in water, but silicon dioxide, aluminum oxide, titanium oxide, zinc oxide, oxidation Inorganic oxides such as iron and layered silicates such as talc, mica and sericite are suitable.

Substances that exhibit hydrophobicity Substances that exhibit hydrophobicity used in the production of anisotropic particles according to the present invention include C ₃ H ₇ SiCl ₃ , C ₆ H ₁₃ Si (OC ₂ H ₅ ) ₃ , C _{8 H 17 Si (OC 2 H} 5) 3, C 6 H 5 Si (OC 2 H 5) 3 silane coupling agent such _{as, C 8 F 17 CH 2 CH} 2 Si (OC 2 H 5) 3, C 8 Perfluoroalkyl group-containing silane couplings such as F ₁₇ CONH (CH ₂ ) _n Si (OCH ₃ ) ₃ , C ₈ F ₁₇ (CH ₂ ) _n NCO (where n is preferably 1 to 10) In addition to the agent, an aluminum coupling agent, a titanium coupling agent, or the like can also be used.
The anisotropic particle concerning this invention may be coat | covered using 1 type, or 2 or more types of the substance which expresses said hydrophobicity.

  FIG. 1 schematically shows the configuration of anisotropic particles according to the present invention. As shown in FIG. 1, the anisotropic particles 1 are obtained by chemically bonding a local surface of one side of a base powder 2 such as silicon dioxide with a substance 3 that expresses hydrophobicity such as n-propyltrichlorosilane. Yes.

  In the present invention, the coating with the substance that exhibits hydrophobicity is characterized in that it is densely formed in the local coating portion. In the present invention, “locally” does not mean that it is scattered over the entire surface of the base powder, but means a part of the one-sided hemisphere surface, or a continuous part of the entire one-sided hemispherical surface or the one-sided hemispherical surface or more. To do.

Further, “densely” means that a substance that expresses hydrophobicity is uniformly and densely coated. For example, the density of the anisotropic particles according to the present invention can be expressed by the ratio of the distribution area of carbon by the hydrophobic substance with respect to an arbitrary covering portion area, that is, the area occupation ratio. The area occupancy is calculated by the following measurement method.
Measuring instrument: SEM-EDX (scanning electron microscope, energy dispersive X-ray analyzer) (manufactured by Hitachi, Ltd.)
Measurement method: The surface of the anisotropic particle was observed with SEM-EDX, the area of the arbitrary coating portion and the carbon distribution area in the coating portion were measured by image analysis, and the area occupancy was calculated.
In the present invention, the average coverage is 40 to 80%.

Next, the manufacturing method of the anisotropic particle concerning this invention is demonstrated.
The method for producing anisotropic particles according to the present invention includes:
A step of mixing and stirring a non-aqueous solvent phase and a substance that exhibits hydrophobicity chemically bonded by a condensation reaction with the base powder, and subsequently adding an aqueous phase in which the base powder is dispersed, The base powder is gathered at the interface of the aqueous phase, the surface of the base powder is caused to undergo a condensation reaction with a substance that exhibits a substantially hydrophobic property, and the base powder is densely coated locally.
The non-aqueous solvent phase contains an oil component described in detail below, and the aqueous phase contains water, a raw material component of a hydrophobic material covering the base powder, and a catalyst used to convert the raw material component into a hydrophobic material. Including.
Below, the component used for a manufacture process is demonstrated in detail.

Non-aqueous solvent phase used for producing the anisotropic particles according to the non-aqueous solvent phase present invention, oil liquid is preferably used at room temperature. Specifically, organic solvents such as benzene, toluene and hexane, silicone oils such as methylpolysiloxane and methylphenylpolysiloxane, hydrocarbon oils such as liquid paraffin, isoparaffin, squalane and squalene, isopropyl myristate, 2-myristate 2- Octyldecyl, 2-octyldecyl myristate, cetyl 2-ethylhexanoate, 2-ethylhexyl 2-ethylhexanoate, isononyl 2-ethylhexanoate, 2-ethylhexyl palmitate, 2-hexyldecyl stearate, ethyl isostearate, Examples thereof include ester oils such as isopropyl isostearate and 2-ethylhexyl salicylate, and oils such as olive oil, camellia oil, macadamia nut oil, and castor oil.
In the present invention, one or more of the above oils may be used.

In addition, the non-aqueous solvent layer used when producing the anisotropic particles according to the present invention includes a raw material component of a hydrophobic substance. The “raw material component of the hydrophobic substance” means the above-mentioned C ₃ H ₇ SiCl ₃ , C ₆ H ₁₃ Si (OC ₂ H ₅ ) ₃ , C ₈ H ₁₇ Si (OC ₂ H ₅ ) ₃ , C ₆ H _5. Silane coupling agents such as Si (OC ₂ H ₅ ) ₃ , C ₈ F ₁₇ CH ₂ CH ₂ Si (OC ₂ H ₅ ) ₃ , C ₈ F ₁₇ CONH (CH ₂ ) _n Si (OCH ₃ ) ₃ , C _{In addition to} perfluoroalkyl group-containing silane coupling agents such as ₈ F ₁₇ (CH ₂ ) _n NCO (where n is preferably 1 to 10), aluminum coupling agents, titanium coupling agents, etc. It corresponds to 1 type or 2 types or more chosen from.

The aqueous phase used for manufacturing the anisotropic particles according to the aqueous phase present invention is characterized by comprising water and based powder.
The aqueous phase contains a catalyst used for converting the raw material component of the hydrophobic substance into a hydrophobic substance.

When the aqueous phase containing the “catalyst” and in which the base powder is dispersed is added to the non-aqueous solvent phase and the “raw material component of the hydrophobic material” mixed and stirred, It serves to promote a reaction for the “raw material component” to be converted into a hydrophobic substance. Details of the catalyst will be described later.
In the method for producing anisotropic particles according to the present invention, the mixing ratio (W / O ratio) of the aqueous phase and the oil is preferably 10/90 to 70/30. In preparing the water-in-oil type powder emulsifying base, such a blending ratio is preferable. When the W / O ratio is less than 10/90, the amount of powder required for emulsification is small and the production efficiency is significantly reduced. On the other hand, when the W / O ratio is greater than 70/30, it is difficult to prepare a stable water-in-oil type emulsion base.

Catalyst The catalyst contained in the aqueous phase is not particularly limited as long as the raw material component that exhibits hydrophobicity can be converted into a hydrophobic substance, but is appropriately selected and blended depending on the raw material component to be used. . Specifically, when n-propyltrichlorosilane is used, aqueous ammonia and pyridine can be used.
Furthermore, the conversion to the hydrophobic substance of the raw material component which expresses hydrophobicity may be accelerated | stimulated by heating to about 100 degreeC.
The blending amount of the catalyst is appropriately determined as an amount necessary for converting the “raw material component expressing hydrophobicity” into a hydrophobic substance.

In the method for producing anisotropic particles according to the present invention, the blending amount of the base powder is preferably 0.1 to 20% with respect to the total amount of the oil and the water phase. If it is less than 0.1%, the amount is not sufficient for the production of anisotropic particles, and if it exceeds 20%, the dispersibility in the non-aqueous solvent phase is deteriorated.
Moreover, it is suitable that the compounding quantity of the raw material component of a hydrophobic substance is 0.1 to 20% with respect to the total amount of an oil component and a water phase. If it is less than 0.1%, the amount is not sufficient to cover the surface of the base powder, and even if it exceeds 20%, no improvement in the effect due to the increase is observed.

Principle When a water phase containing a catalyst and having a base powder dispersed therein is added while stirring the non-aqueous solvent phase and the raw material component of the hydrophobic substance, the non-aqueous solvent phase and the aqueous phase are not mixed. And an aqueous phase interface. The base powder is arranged at the interface between the non-aqueous solvent phase and the aqueous phase, and the catalyst coexists with the raw material component of the hydrophobic substance, so that the hydrophobic substance is condensed with the base powder at the interface between the non-aqueous solvent phase and the aqueous phase. Are chemically bound by. By adding the aqueous phase containing the catalyst after preparing the non-aqueous solvent phase and the raw material component of the hydrophobic substance, a part or all of the one-side surface on the non-aqueous solvent phase side of the base powder particles, or the one-side surface As described above, the hydrophobic substances are aggregated, and a characteristic dense coating state of the anisotropic particles according to the present invention is obtained.
FIG. 2 shows the structure of the base powder arranged at the interface between the non-aqueous solvent phase and the aqueous phase, which is prepared in the course of the manufacturing method. In the figure, the non-aqueous solvent phase 6 contains a raw material component of a hydrophobic substance covering the oil and base powder, and the aqueous phase 5 contains water and a catalyst used to convert the raw material component into a hydrophobic substance. .

Further, the one side surface of the base powder particles on the non-aqueous solvent phase side is sufficiently covered with the non-aqueous solvent phase in which the hydrophobic substance is present, so that it is coated. Further, all of the base powder particles arranged at the interface between the non-aqueous solvent phase and the aqueous phase are efficiently coated with the hydrophobic substance. At this point, anisotropic particles according to the present invention are formed.
After the surface of one side of the base powder particles facing the non-aqueous solvent phase has sufficiently reacted with the hydrophobic substance, only the base powder is recovered by a centrifuge or the like, and dried, whereby the anisotropy according to the present invention is achieved. The particles are isolated.
As a stirring method employed in the production of anisotropic particles according to the present invention, a method usually used for preparing an emulsified composition can be used. Specific examples include a stirrer, a propeller mixer, a disper, a homomixer, and a homogenizer.

The anisotropic particles according to the present invention can be used as an emulsifying base. Examples of the emulsion composition prepared by such use include water-in-oil, oil-in-water, and polyhydric alcohol-in-oil emulsions, multiple emulsions, and the like.
The cosmetic according to the present invention is excellent in an emulsified state by including the anisotropic particles. Moreover, it can be applied to a wide range of cosmetics regardless of the type of oil depending on the specific coating state of the hydrophobic material of the anisotropic particles.

The content of the anisotropic particles contained in the cosmetic according to the present invention is not particularly limited as long as the effect of the present invention can be obtained, and can be appropriately adjusted and used. .1 to 20% by mass. If it is less than 0.1% by mass, the effects of the present invention may not be exhibited, and if it exceeds 20% by mass, it may be unfavorable in terms of formulation.
The cosmetics according to the present invention include components used in ordinary cosmetics, for example, moisturizers, antioxidants, oily components, ultraviolet absorbers, emulsifiers, surfactants, within the range that does not impair the effects of the present invention. , Thickeners, alcohols, powder components, color materials, aqueous components, water, various skin nutrients, and the like can be appropriately blended as necessary.

  Cosmetics according to the present invention include, for example, ointments, creams, emulsions, lotions, packs, foundations, blushers, eye shadows, white powders, lipsticks, bath preparations, oil blotting paper, paper powder, body powders, baby powders, powder sprays, etc. Any form can be applied as long as it is used for conventional cosmetics, and the dosage form is not particularly limited.

EXAMPLES Hereinafter, although an Example is given concretely and this invention is demonstrated in more detail, this invention is not limited by these Examples.
In the present invention, the average particle diameter of anisotropic particles was measured as follows.
The particles were observed with a scanning electron microscope, and the average value of the particle sizes of 100 randomly extracted particles was defined as the average particle size.

Initially, the manufacture example of the anisotropic particle concerning this invention is shown below.
Production Example 1
20 μL of n-propyltrichlorosilane was added to 40 g of toluene, and the mixture was sufficiently dispersed by stirring for 1 minute using a stirrer to obtain a non-aqueous solvent phase.
As a base powder in a separate container, 1 g of a plate-like synthetic gold-fluorine phlogopite with an average particle diameter of 5 to 7 μm (trade name: Mica PDM-5L, manufactured by Topy Industries, Ltd.) exceeds 10 g of a 0.1 mol / L aqueous ammonia solution. A water phase was obtained by sufficiently dispersing using sound waves.
Subsequently, the aqueous phase was gradually added while stirring the non-aqueous solvent phase with a stirrer, and then the mixture was vigorously stirred for 15 hours. The powder was collected by filtration, washed with ion-exchanged water, and heated at 120 ° C. for 12 hours. By drying, a powder having surface active ability is isolated.

Production Example 2
20 μL of n-propyltrichlorosilane was added to 40 g of toluene, and the mixture was sufficiently dispersed by stirring for 1 minute using a stirrer to obtain a non-aqueous solvent phase.
As a base powder in a separate container, 1 g of spherical silicic acid having an average particle size of 4 to 6 μm (trade name: Spherical Silica P-1500, produced by Catalyst Chemical Industry Co., Ltd.) is sufficiently applied to 10 g of ion-exchanged water using ultrasonic waves. Dispersed to form an aqueous phase.
Subsequently, the aqueous phase was gradually added while stirring the non-aqueous solvent phase with a stirrer, and then the mixture was vigorously stirred for 15 hours. The powder was collected by filtration, washed with ion-exchanged water, and heated at 120 ° C. for 12 hours. By drying, a powder having surface active ability is isolated.

The microscope picture which image | photographed the real image of the anisotropic particle | grains which obtained the silicic acid anhydride obtained by manufacture example 2 by FIG. 3 with n-propyl trichlorosilane is shown. FIG. 4 shows a photomicrograph of the silicon distribution image of the anisotropic particles obtained in Production Example 2. Since the silicon is derived from silicic anhydride, which is a hydrophilic base powder, the anisotropic particles according to the present invention are formed based on the base powder by comparing FIG. 3 and FIG. It was confirmed.
On the other hand, the microscope picture which image | photographed the carbon distribution image of the anisotropic particle | grains by which FIG. 5 obtained by manufacture example 2 was coated with the anhydrous silicic acid with n-propyltrichlorosilane is shown. The carbon is not derived from silicic anhydride, which is a base powder, but derived from n-propyltrichlorosilane, which is a hydrophobic substance. Therefore, by comparing FIG. 5, FIG. 3 and FIG. 4, it was confirmed that the hydrophobic substance was present locally in the particles of the base powder.

Moreover, from the SEM-EDX electron micrograph image which image | photographed the anisotropic particle obtained in manufacture example 2, arbitrary coating part area and the carbon distribution area in this coating part in several places are used using image analysis. The area occupancy was calculated (measurements 1 to 6). Table 1 shows the results of the occupation ratio of the carbon distribution area.

  From the results of Table 1 above, it is confirmed that the anisotropic particles obtained according to the present invention have the hydrophobic substance densely present on one side surface of the base powder particles, and the area occupancy is 40-80. % Became clear.

Comparative Example 1
20 μL of n-propyltrichlorosilane was added to 40 g of toluene, and the mixture was sufficiently dispersed by stirring for 1 minute using a stirrer to obtain a non-aqueous solvent phase.
Subsequently, 1 g of spherical silicic acid having an average particle size of 4 to 6 μm (trade name: Spherical Silica P-1500, manufactured by Catalytic Chemical Industry Co., Ltd.) as a base powder was added to the non-aqueous solvent phase, and then 20 μL of pyridine was added. After stirring vigorously for 15 hours under heating and refluxing, the powder was collected by filtration, washed with ion-exchanged water, and then heated and dried at 120 ° C. for 12 hours to isolate the powder.

Next, a test for confirming the surface activity as a powder emulsifier was carried out using the anisotropic particles obtained in Production Examples 1 and 2. The test method and evaluation method are as follows.
Test Method After adding water to the oil with the composition shown in Table 2 below, the test powder was added and dispersed with a disper for 1 minute to obtain a water-in-oil (W / O) emulsion.
In addition, all the numerical values described in Table 1 below are parts by weight.

Evaluation Method / Evaluation Criteria The emulsified state of each emulsion obtained by the test method was visually determined.
○: The particle size distribution is narrow, and spherical emulsified particles form an emulsified layer.
Δ: An emulsified layer is formed, but coalescence of emulsified particles is observed over time.
X: The emulsified layer is hardly formed.

* 1: Product name Mica PDM-5L Topy Industries, Ltd.

As is apparent from Table 2 above, when the anisotropic particles of the present invention were emulsified using dimethylpolysiloxane, an emulsion having excellent stability with a uniform emulsion particle diameter was obtained (test). Examples 1, 2). This is because the n-propyltrichlorosilane moiety exhibiting hydrophobicity and the relatively highly hydrophilic synthetic gold-fluorine phlogopite part or silicic acid moiety exist separately on the particle. On the oil side, the synthetic gold-fluorine phlogopite part or the silicic acid anhydride part is preferentially oriented on the moisture side, and it is judged that a W / O emulsion could be formed when various oils were used.
On the other hand, although the powder of Comparative Example 1 temporarily forms an emulsified layer after disperse dispersion, coalescence of the emulsified particles proceeds after a while, and finally it is separated into a non-aqueous solvent phase and an aqueous phase (Test Example 3). ). In Test Example 4, the powder was completely dispersed in the aqueous phase, and the emulsified state could not be achieved.

Furthermore, the example of the composition which mix | blended the anisotropic particle concerning this invention is shown below.
W / O cream (1) Cyclomethicone 28.4% by mass
(2) Liquid paraffin 5.0
(3) Benton 10.0
(4) Anisotropic particles obtained in Production Example 1 3.5
(5) Propylparaben 0.1
(6) Glycerin 3.0
(7) Methylparaben 0.2
(8) Purified water residue (production method)
While stirring at a temperature of 25 ° C., the anisotropic particles of (4) Production Example 1 are dispersed in the oily components of components (1), (2), and (5), and components (6) to (8) are dispersed therein. Was poured, and then (3) was added to obtain the desired W / O cream.

O / W sunscreen oil phase (1) Squalane 4.0% by mass
(2) Octyl methoxycinnamate 8.0
(3) Cyclopentadimethylsiloxane 5.0
(4) Fragrance 0.1
Water phase 1
(5) 1,3-butylene glycol 5.0
(6) Ethanol 2.0
(7) Anisotropic particles obtained in Production Example 2 3.0
(8) Purified water Appropriate amount of water phase 2
(9) Succinoglycan 0.2
(10) Glycerol 3.0
(11) L-arginine L-aspartate 0.01
(12) Edetate 0.05
(13) Methylparaben appropriate amount (14) Purified water Residue (Production method)
The aqueous phase 1 is heated to 70 ° C., dispersed with a mixer or ultrasonic waves, and then the uniformly dissolved aqueous phase 2 is added. Further, an oil phase heated to 70 ° C. is added and emulsified with an emulsifier. This was cooled to obtain the desired O / W sunscreen.

Dual-use foundation powder part (1) Silicone-treated talc 16.2% by mass
(2) Silicone-treated mica 40.0
(3) Silicone-treated titanium dioxide 15.0
(4) Silicone-treated ultrafine titanium dioxide 5.0
(5) Silicone-treated Bengala 1.0
(6) Silicone-treated yellow iron oxide 3.0
(7) Silicone-treated black iron oxide 0.2
(8) Zinc stearate 0.1
(9) Anisotropic particles of Production Example 2 5.0
(10) Ethylparaben Appropriate amount of oil phase (11) Squalane 4.0
(12) Solid paraffin 0.5
(13) Dimethylpolysiloxane 4.0
(14) Glycerin triisooctanoate 5.0
(15) Octyl methoxycinnamate 1.0
(16) Antioxidant (Vitamin E) Appropriate amount (17) Fragrance Appropriate amount (Manufacturing method)
(1) to (7) are pulverized and mixed with a pulverizer, and the remaining powder part is added and mixed well. The oil phase components (11) to (17) were uniformly blended into the powder part, and then pulverized and mixed with a pulverizer. Furthermore, it compression-molded through the sieve to the inside plate, and obtained the target amphibious foundation.

It is the figure which showed schematic structure of the anisotropic particle concerning this invention. It is the figure which showed schematic structure of the water-in-oil type powder emulsification base in the manufacture process of the anisotropic particle concerning this invention. It is a SEM-EDX electron micrograph of the anisotropic particle (manufacture example 2) concerning this invention. It is a SEM-EDX electron micrograph which image | photographed the silicon distribution of the anisotropic particle (manufacture example 2) concerning this invention. It is a SEM-EDX electron micrograph which image | photographed carbon distribution of the anisotropic particle (manufacture example 2) concerning this invention.

Explanation of symbols

1. Anisotropic particles2. 2. base powder 3. Hydrophobic substance synthesized in non-aqueous solvent phase 4. Base powder assembled at the interface between the non-aqueous solvent phase and the aqueous phase Aqueous phase 6. Non-aqueous solvent phase

Claims (13)

  An anisotropic particle characterized in that the particle surface of the base powder is densely coated locally with a hydrophobic substance.   The anisotropic particle according to claim 1, wherein the base powder is a powder that is uniformly dispersed in water.   The anisotropic particles according to claim 1 or 2, wherein the base powder is one or more selected from silicon dioxide, aluminum oxide, mica, sericite, talc, titanium oxide, and zinc oxide. Anisotropic particles.   The anisotropic particle according to any one of claims 1 to 3, wherein the substance exhibiting hydrophobicity undergoes a condensation reaction and chemically binds to the base powder.   The anisotropic particles according to any one of claims 1 to 4, wherein the base powder has an average particle size of 0.01 to 100 µm.   Cosmetics which mix | blended the anisotropic particle in any one of Claims 1-5.   The emulsified composition which mix | blended the anisotropic particle in any one of Claims 1-5. Mixing and stirring a non-aqueous solvent phase that is not compatible with water and a hydrophobic substance that is chemically bonded by a condensation reaction with the base powder;
An aqueous phase in which the base powder is dispersed is added, and the base powder aggregates at the interface between the non-aqueous solvent phase and the aqueous phase. A method for producing anisotropic particles, comprising: a step of densely coating the particles.   The method for producing anisotropic particles according to claim 8, wherein the mixing ratio of the aqueous phase and the non-aqueous solvent phase is 10/90 to 70/30.   The method for producing anisotropic particles according to claim 8 or 9, wherein the mixing ratio of the base powder is 0.1 to 20% with respect to the total amount of the non-aqueous solvent phase and the aqueous phase. A method for producing anisotropic particles. The method for producing anisotropic particles according to any one of claims 8 to 10, wherein the substance that is chemically bonded by the condensation reaction with the base powder and exhibits hydrophobicity is represented by the following general formula (1). A method for producing anisotropic particles, comprising one or more selected from the following materials.
(In the formula, X is one or more hydrolyzable groups selected from the group consisting of —Cl, —OCH ₃ , and —OC ₂ H ₅ , and Y is a linear hydrocarbon having 3 to 20 carbon atoms. A substituted hydrocarbon group substituted with a group, a branched hydrocarbon group, a cyclic hydrocarbon group, or a cyano group, a hydroxyl group, a carboxyl group, an acid amide group, an imide group, a sulfone group, an amino group, or a glyceroyl group.   The method for producing anisotropic particles according to claim 11, wherein the blending ratio of the substance that exhibits hydrophobicity contained in the non-aqueous solvent phase is 0.1% with respect to the total amount of the non-aqueous solvent phase and the aqueous phase. A method for producing anisotropic particles, characterized in that it is -20%.   The method for producing anisotropic particles according to any one of claims 8 to 12, wherein the aqueous phase contains a catalyst for a condensation reaction of a substance that exhibits hydrophobicity. Production method.