WO2017026379A1 - Flake-shaped hydrotalcite-type particle and application thereof - Google Patents

Abstract

The present invention provides flake-shaped hydrotalcite-type particles having superior glide and sufficiently reduced ability to cause skin irritation. The present invention also provides a cosmetic containing said flake-shaped hydrotalcite-type particles. The flake-shaped hydrotalcite-type particles are represented by a prescribed structural formula and have an average flake surface diameter of 150-800nm, an aspect ratio (average flake surface diameter/average thickness) of 4.0-20.0, and a pH value of 6.0-8.5 according to the JIS K5101-17-1 (2004) test methods for pigments.

Description

Plate-like hydrotalcite-type particles and uses thereof

The present invention relates to plate-like hydrotalcite-type particles and uses thereof.

Hydrotalcite is a kind of layered clay mineral and is widely used for various applications such as catalysts, pharmaceuticals, and additives for resins. Even in cosmetic applications, particulate hydrotalcite (referred to as hydrotalcite-type particles) is used with the expectation of imparting functions such as adsorption of excess sebum, prevention of makeup collapse and shine.

Many of the conventional hydrotalcite-type particles are Mg—Al-based hydrotalcite-type particles containing magnesium and aluminum as constituent elements (see, for example, Patent Document 1). However, Mg—Zn—Al-based hydrotalcite-type particles containing zinc as a constituent element in addition to magnesium and aluminum (see, for example, Patent Document 2), and Zn—Al-based hydrousite containing zinc and aluminum as constituent elements. Talsite-type particles (see, for example, Patent Documents 3 to 6) have also been developed.

JP 2000-247633 A JP 2004-299931 A JP 2002-226826 A Japanese Patent Laid-Open No. 11-209258 Japanese Patent Laid-Open No. 11-240886 Japanese Patent Application Laid-Open No. 11-255993

As described above, most of the conventional hydrotalcite-type particles are Mg—Al-based hydrotalcite-type particles, but are basic due to the constituent element magnesium. In applications such as cosmetics, the basicity may irritate the skin and adversely affect the skin, so when using Mg-Al-based hydrotalcite-type particles, the amount of addition may be limited, At present, the basicity is reduced by a combination of the above. As a means for reducing the basicity of Mg—Al-based hydrotalcite-type particles, it is conceivable to replace zinc (Zn), which is an amphoteric metal, with part or all of magnesium, but the conventional Mg—Zn— In the Al-based hydrotalcite-type particles, zinc only replaces a part of the magnesium site, and the basicity is not sufficiently reduced.

By the way, in cosmetics applications, the shape of the particles is desired to be plate-like rather than granular. This is because the slipperiness is better than the granular particles, and the coverage and orientation are also excellent. However, conventional Zn—Al hydrotalcite-type particles are granular particles having an aspect ratio of 1 to 2, and there have been no reports of plate-like particles. This is because Zn-Al-based hydrotalcite-type particles have a lower ability to hold anions between layers than Mg-Al-based hydrotalcite-type particles, so conventional Mg-Al-based or Mg-Zn When the Zn-Al-based plate-like hydrotalcite-type particles are produced by directly applying the method for synthesizing -Al-based plate-like hydrotalcite-type particles, a part of the raw water-soluble zinc compound (for example, zinc sulfate) is produced. It is thought that this is caused by the fact that it becomes zinc hydroxide during the formation of the precursor and finally becomes zinc oxide, and the layered structure of hydrotalcite cannot be maintained. As a method for producing Zn—Al-based hydrotalcite-type particles, a method of growing particles by hydrothermal reaction after removing zinc hydroxide by filtering the precursor slurry (Patent Document 6, etc.) However, plate-like particles cannot be obtained by this method.

The present invention has been made in view of the above situation, and an object of the present invention is to provide plate-like hydrotalcite-type particles that are excellent in slipperiness and sufficiently reduced in irritation to the skin. Another object of the present invention is to provide a cosmetic containing such plate-like hydrotalcite-type particles.

While the present inventor has intensively studied hydrotalcite-type particles, the present inventors have succeeded in producing Zn-Al-based hydrotalcite-type particles having zinc and aluminum as constituent elements and having a plate-like shape. The plate-like hydrotalcite-type particles have a large average plate surface diameter, an appropriate thickness, and a pH value by a predetermined test method is also in an appropriate range, and the proportion of particles having a plate-like shape is high. The slipperiness and the feeling of application to the skin when included in cosmetics are good, and the irritation to the skin is sufficiently reduced. In addition, since the adsorption performance of ammonia gas and phosphorus compound is also excellent, it has been found useful for various applications, and it has been conceived that the above-mentioned problems can be solved, and the present invention has been completed.

That is, the present invention provides the following formula (1):
(Zn) _1-x (Al) _x (OH) ₂ (A ⁿ⁻ ) _{x / n} · mH ₂ O (1)
(In the formula, A ⁿ⁻ represents an n-valent interlayer anion. X and n are numbers satisfying the conditions of 0.2 ≦ x ≦ 0.4 and 1 ≦ n ≦ 4, respectively. m is a number of 0 or more.), the average plate surface diameter is 150 to 800 nm, the aspect ratio (average plate surface diameter / average thickness) is 4.0 to 20.0, JIS K5101-17-1 (2004) plate-like hydrotalcite-type particles having a pH value of 6.0 to 8.5 according to the pigment test method.

The plate-like hydrotalcite-type particles preferably have a pore volume of 0.01 to 1.0 cm ³ / g according to the BJH method. As a result, the feeling of smoothness, uniform stretchability and smoothness when touching the particle powder is further improved. For example, when cosmetics containing hydrotalcite particles are applied to the skin As a result, the sustainability of smoothness is further improved.

The plate-like hydrotalcite-type particles are preferably partially or entirely covered with a silicon compound. In addition to suppressing excessive elution of zinc ions and reducing irritation to the skin to express an appropriate astringent action, compatibility and dispersibility with resins and solvents are improved, and water repellency is also achieved. In order to improve, it becomes useful not only for cosmetics but also for various uses such as additives to resins.

In the above formula (1), x and n are each, 0.30 ≦ x ≦ 0.35,1 ≦ n ≦ 3 integers, a satisfying number ^{of, A n-carbonate} ion _(CO ^{3 2 -} ) Is preferred. Thereby, since the crystal shape becomes more stable, it becomes possible to give a stable and excellent slipperiness and a feeling to the skin when included in cosmetics.

The present invention is also a cosmetic containing the plate-like hydrotalcite-type particles. Such a cosmetic is excellent in slipperiness and the feeling of application to the skin when it is included in the cosmetic, and the irritation to the skin is sufficiently reduced.

The plate-like hydrotalcite-type particles of the present invention are excellent in slipperiness and the feeling of application to the skin when included in cosmetics, and the irritation to the skin is sufficiently reduced. Useful for. In addition, since it has excellent adsorption performance for ammonia gas and phosphorus compounds, it is also useful for applications such as cosmetics and adsorbents to which these adsorption capabilities are added.

2 is an X-ray diffraction pattern of plate-like hydrotalcite-type particles obtained in Example 11. FIG. It is the electron micrograph which image | photographed the plate-shaped hydrotalcite type particle | grains obtained in Example 11 so that thickness could be measured (magnification: 50,000 times). It is the electron micrograph which image | photographed the plate-shaped hydrotalcite type particle | grains obtained in Example 11 so that thickness could be measured (magnification: 20,000 times). It is the electron micrograph which image | photographed the plate-shaped hydrotalcite type particle | grains obtained in Example 11 so that plate | board surface diameter could be measured (magnification | multiplying_factor: 50,000 times). It is the electron micrograph which image | photographed the plate-shaped hydrotalcite type particle | grains obtained in Example 11 so that a plate | board surface diameter could be measured (magnification | multiplying_factor: 20,000 times). It is the graph which contrasted the time-dependent change of the phosphate ion concentration at the time of adsorbing potassium hydrogen phosphate using each of the hydrotalcite-type particles obtained in Example 11 and Reference Example 1 (initial value of phosphate ion concentration). : 50 ppm). It is the graph which contrasted the time-dependent change of the phosphate ion concentration at the time of adsorbing potassium hydrogen phosphate using each of the hydrotalcite-type particles obtained in Example 11 and Reference Example 1 (initial value of phosphate ion concentration). : 25 ppm). It is the graph which contrasted the time-dependent change of the phosphate ion concentration at the time of adsorbing potassium hydrogen phosphate using each of the hydrotalcite-type particles obtained in Example 11 and Reference Example 1 (initial value of phosphate ion concentration). : 5 ppm). It is the graph which contrasted the time-dependent change of ammonia concentration at the time of making ammonia gas adsorb | suck using each of the hydrotalcite type particle | grains obtained in Example 11, the comparative example 18, and the reference example 1. FIG. It is a graph which shows the result of having performed the differential heat measurement about the hydrotalcite type particle obtained in Example 11 and Reference Example 1. It is a graph which shows the result of having performed the thermogravimetry about the hydrotalcite type particle obtained in Example 11 and Reference Example 1.

Hereinafter, although the preferable form of this invention is demonstrated concretely, this invention is not limited only to the following description, In the range which does not change the summary of this invention, it can change suitably and can apply.

[Plate-like hydrotalcite-type particles]
The plate-like hydrotalcite-type particles of the present invention have the following formula (1):
(Zn) _1-x (Al) _x (OH) ₂ (A ⁿ⁻ ) _{x / n} · mH ₂ O (1)
(In the formula, A ⁿ⁻ represents an n-valent interlayer anion. X and n are numbers satisfying the conditions of 0.2 ≦ x ≦ 0.4 and 1 ≦ n ≦ 4, respectively. m is a number greater than or equal to 0.)

In the above formula (1), the n-valent interlayer anion is not particularly limited, but hydroxide ion (OH ⁻ ), carbonate ion (CO ₃ ²⁻ ) and sulfate ion ( At least one selected from the group consisting of SO ₄ ²⁻ ) is preferred. Of these, carbonate ions are preferred.

x is a number satisfying 0.2 ≦ x ≦ 0.4, but if it is within this range, the crystal structure is stabilized. From the viewpoint of further improving the stability, it is preferable to adjust x so that [(1-x) / x] is 1.5 / 1 to 3/1. More preferably, it is adjusted to be 2/1. From this viewpoint, x is preferably 0.25 or more, more preferably 0.3 or more, and preferably 0.35 or less. Particularly preferred is 1/3 (= about 0.33).

n is a number satisfying 1 ≦ n ≦ 4 and may be appropriately adjusted depending on the valence of the interlayer anion. Preferably it is an integer of 1 to 3, more preferably 2.

m is a number of 0 or more. This m can be theoretically obtained by analyzing the crystal structure, but in reality, it is difficult to accurately measure the presence of the adhering water. Theoretically, it is preferably 0 or more and less than 5, for example.

Particularly in this invention, in the above formula (1), x and n are each, 0.30 ≦ x ≦ 0.35,1 ≦ n ≦ 3 integers, a satisfying number ^{of, A n-carbonate} It is preferably an ion (CO ₃ ²⁻ ). Thereby, since the crystal shape becomes more stable, it becomes possible to stably give excellent slipperiness and a good application feel to the skin when it is included in cosmetics.

Most preferably, the plate-like hydrotalcite type particles are represented by the following formula (2):
(Zn) _0.67 (Al) _0.33 (OH) ₂ (CO ₃ ²⁻ ) _0.165 · mH ₂ O (2)
It is a plate-like particle | grain represented by these. With this structure, the crystal structure is extremely stable, and the effects of the present invention can be more fully exhibited. This structure can be confirmed from JCPDS card 00-048-1023.

The plate-like hydrotalcite-type particles have an average plate surface diameter of 150 to 800 nm. If the average plate surface diameter is within this range, the fluidity of the powder containing particles will be stable, making it easy to handle during weighing and packaging, and the feel and slipperiness when applied to the skin. Even better. Preferably it is 180 nm or more, More preferably, it is 190 nm or more, More preferably, it is 300 nm or more, Preferably it is 500 nm or less, More preferably, it is 470 nm or less.

The aspect ratio (average plate surface diameter / average thickness) of the plate-like hydrotalcite particles is 4.0 to 20.0. If the aspect ratio is within this range, the fluidity of the powder containing the particles will be stable, making it easier to handle during weighing and packaging, as well as the feel and slipperiness when applied to the skin. It will be excellent. Preferably it is 4.5 to 15.0, more preferably 5.0 to 10.0. In particular, the average value (that is, the average value of the aspect ratio) when the operation for obtaining the aspect ratio from the average plate surface diameter and the average thickness is repeated 10 times is preferably 4.0 to 20.0. More preferably, it is 4.5 to 15.0, and still more preferably 5.0 to 10.0.
In the present specification, the average plate surface diameter and the average thickness are values calculated based on a scanning electron micrograph. Specifically, it is determined according to the method described in Examples described later.

Here, the plate-like hydrotalcite-type particles of the present invention are plate-like and have an important feature in having a certain aspect ratio, but at the same time, there is little variation in particle shape and aspect ratio. There are features. In order to improve or maintain the skin feel and slipperiness when included in cosmetics, when the aspect ratio is measured 10 times, the measured aspect ratio value is less than 4.0 or 20. The number of times exceeding 0 is preferably 3 or less. Moreover, it is preferable that the coefficient of variation of the standard deviation calculated when the average plate surface diameter and the average thickness are measured is 0.5 or less, respectively. More preferably, it is 0.4 or less.

The plate-like hydrotalcite-type particles have a pH value (also referred to as “pigment pH”) of 6.0 to 8.5 according to the pigment test method of JIS K5101-17-1 (2004). When the pigment pH is within this range, the irritation to the skin is sufficiently reduced, and thus it is particularly useful for applications such as cosmetics that directly touch the skin. The pigment pH is preferably 7.0 to 8.4, more preferably 7.2 to 8.2.
In the present specification, the pigment pH is a value measured by a pigment test method of JIS K5101-17-1 (2004). Specifically, it is determined according to the method described in Examples described later.

The plate-like hydrotalcite-type particles preferably have a specific surface area of 0.1 to 50 m ² / g. When the specific surface area is in this range, it has more sufficient strength, and the slipperiness and the feeling of application to the skin when it is included in the cosmetics are further improved. More preferably, it is 5 to 40 m ² / g, and still more preferably 10 to 20 m ² / g.

In the present specification, the specific surface area (also referred to as SSA) means the BET specific surface area.
The BET specific surface area refers to a specific surface area obtained by the BET method, which is one method for measuring the specific surface area. The specific surface area refers to the surface area per unit mass of a certain object.
The BET method is a gas adsorption method in which gas particles such as nitrogen are adsorbed on solid particles and the specific surface area is measured from the amount adsorbed. Specifically, the specific surface area is determined by obtaining the monomolecular adsorption amount VM by the BET equation from the relationship between the pressure P and the adsorption amount V. A detailed method for measuring the specific surface area in the present specification will be described in Examples described later.

The plate-like hydrotalcite-type particles is preferably ratio _{D 10} of _{D 90} indicative of sharpness of volume-based particle size distribution _(D 90 _{/ D 10)} is 2 to 150. When D ₉₀ / D ₁₀ is within this range, there is little variation in the particle diameter, and the fluidity of the powder containing particles is stabilized. Therefore, it becomes easy to handle at the time of weighing and packaging, and it is excellent in the feeling of application to the skin and slipperiness when included in cosmetics. When the value of D ₉₀ / D ₁₀ is increased, the coating feel on the skin when it is included in the cosmetic tends to be improved. Therefore, the value of D ₉₀ / D ₁₀ is more preferably 10 or more, and further preferably 30 or more. Incidentally, as D _{90 /} D ₁₀ is large, it means that the particle size distribution is broad, smaller value means that the particle size distribution is sharp.
In the present specification, D ₁₀ means a 10% cumulative particle size on a volume basis, and D ₉₀ means a 90% cumulative particle size on a volume basis. D ₁₀ and D ₉₀ are values obtained by measuring the particle size distribution, respectively. Specifically, it is determined according to the method described in Examples described later.

The plate-like hydrotalcite-type particles preferably have a median diameter (D ₅₀ ) of secondary particles of 1 to 200 μm. If the median diameter (D ₅₀ ) is within this range, the fluidity of the powder containing the particles will be stable, and it will be easy to handle during weighing and packaging. Excellent slipperiness.
In the present specification, the median diameter (D ₅₀ ) means a 50% cumulative particle diameter on a volume basis, and when the powder is divided into two parts from a certain particle diameter, the diameter on which the larger side and the smaller side are equal. Say. Specifically, it is determined according to the method described in Examples described later.

The plate-like hydrotalcite-type particles may also have a part or all of the surface thereof coated with a surface coating agent as long as they do not impair a good feeling of application to the skin when included in cosmetics. Good. As the surface coating agent, both inorganic compounds and organic compounds can be suitably used. Although it does not specifically limit as an inorganic compound, For example, oxides, hydroxides, sulfates, carbonates, etc., such as silicon, calcium, barium, strontium, aluminum, zirconium, cerium, zinc, etc. are mentioned. Although it does not specifically limit as an organic compound, For example, silicone oil, a fatty acid, and its metal salt, alkylsilane, alkoxysilane, a silane coupling agent, a titanium coupling agent, an aluminum coupling agent, an amino acid, nylon, carbomer, and its metal salt , Polyacrylic acid, trimethylpropanol, triethylamine, higher alcohols and the like.

Among the surface coating agents, a compound containing a silicon atom (also referred to as a silicon compound) is preferable. That is, it is preferable that a part or all of the surface of the plate-like hydrotalcite-type particle is coated with a silicon compound. In addition to suppressing excessive elution of zinc ions and reducing irritation to the skin to express an appropriate astringent action, compatibility and dispersibility with resins and solvents are improved, and water repellency is also achieved. In order to improve, it becomes useful not only for cosmetics but also for various uses such as additives to resins. Silica is more preferable as the silicon compound.

The method for coating the surface of the plate-like hydrotalcite type particles with the surface coating agent is not particularly limited. For example, when silica is used, a method of adding sodium silicate and an acid to a slurry containing plate-like hydrotalcite-type particles and neutralizing the slurry can be used. The surface coating amount is not particularly limited, but for example, the ratio of the surface coating agent such as silica to 0.001 to 30% by mass with respect to 100% by mass of the total amount of the plate-like hydrotalcite-type particles is preferable. More preferably, it is 5 to 25% by mass.

The plate-like hydrotalcite type particles preferably have an oil absorption of 20 to 300 mL / 100 g. If the amount of oil absorption is within this range, the degreasing effect of the skin can be obtained moderately, so that the skin is not stimulated and irritated, and it becomes more practical as a cosmetic raw material. More preferably, it is 25 to 200 mL / 100 g.
In the present specification, the oil absorption amount is determined according to the method described in Examples described later.

The plate-like hydrotalcite-type particles preferably have a pore volume of 0.01 to 1.0 cm ³ / g according to the BJH method. When the pore volume is 0.01 cm ³ / g or more, the porosity of the particle itself is improved, so that the oil absorption in the pore inside the particle is sufficient, and the particle itself has an appropriate weight. For this reason, when touching the particle powder, the feeling of smoothness, uniform spreadability, and sustainability of smoothness are further improved. On the other hand, if it is 1.0 cm ³ / g or less, the particle itself has an appropriate porosity, so that the particle strength is sufficient, and the particles when the cosmetic containing hydrotalcite particles is applied onto the skin. Is sufficiently suppressed from breaking down, and as a result, the durability of smoothness is further improved. More preferably, it is 0.02 to 0.5 cm ³ / g.
In the present specification, the pore volume is determined using a BJH (Barrett-Joyner-Halenda) method. Specifically, it is determined according to the method described in Examples described later.

The plate-like hydrotalcite-type particles are also excellent in ammonia gas and phosphorus compound adsorption performance. Therefore, it can be suitably used for these adsorbent applications. In particular, the plate-like hydrotalcite-type particles of the present invention are excellent in adsorption performance of phosphorus compounds contained in wastewater discharged from garbage disposal sites and primary treated water discharged from septic tanks such as sewage treatment plants. It is extremely useful as an agent.

〔Production method〕
In order to obtain the plate-like hydrotalcite-type particles of the present invention, for example, a zinc compound and an aluminum compound are used as raw materials, and a precursor having a half width of a peak derived from the (003) plane of 0.4 or more is obtained. It is preferable to employ a production method including the step (I) and the step (II) in which the precursor is held in an atmosphere having a temperature of 75 to 150 ° C. and a relative humidity of 75 to 100% RH. By adopting such a production method, plate-like hydrotalcite-type particles can be obtained easily and simply without introducing a special device / equipment such as a pressure vessel required for hydrothermal synthesis or the like.
Hereinafter, each step will be further described.

<Process (I)>
Step (I) is a step of obtaining a precursor having a half width of a peak derived from the (003) plane of 0.4 or more. In this step (I), the crystallization of hydrotalcite is suppressed to prepare a precursor in a low crystalline state, and this is used in step (II). In step (II), crystal growth to plate-like particles proceeds. Thus, the plate-like hydrotalcite-type particles of the present invention can be obtained easily and simply. The precursor obtained in step (I) may contain hydrotalcite type particles.

In the step (I), one or more zinc compounds and aluminum compounds are used as raw materials. These zinc compounds and aluminum compounds are not particularly limited, but from the viewpoint of facilitating production, it is preferable to use a water-soluble salt or a water-soluble salt containing an acid. Specifically, the zinc compound is preferably at least one selected from the group consisting of zinc hydroxide, zinc oxide, basic zinc carbonate and zinc sulfate, and the aluminum compound includes aluminum hydroxide, aluminum oxide and It is preferably at least one selected from the group consisting of aluminum sulfate. By using these raw materials, plate-like hydrotalcite-type particles can be obtained more easily and simply.

What is necessary is just to adjust the usage-amount of the said raw material so that the obtained plate-like hydrotalcite type | mold particle may satisfy | fill said Formula (1). For example, the zinc compound is preferably 1.5 to 4 mol in terms of zinc with respect to 1 mol in terms of aluminum in the aluminum compound. Thereby, the crystal structure of the obtained plate-like hydrotalcite type particles is stabilized. From the viewpoint of further improving the stability, it is more preferable to adjust the zinc compound so that the amount of zinc compound is 1.5 to 3 mol in terms of zinc with respect to 1 mol in terms of aluminum of the aluminum compound, and more preferably 2 mol. is there.

In the said process (I), it is preferable to neutralize the said raw material using an alkaline component. By performing this neutralization, the precursor can be suitably obtained. The neutralization is preferably performed by mixing the raw material and the alkali component so that the pH of the mixed solution of the raw material and the alkali component is 7 or more. At this time, it may be carried out in the presence of a solvent described later, if necessary. More preferably, the neutralization reaction is performed so that the pH of the mixed solution of the raw material and the alkali component is 7.5 or more.

Although it does not specifically limit as said alkali component, For example, an alkali metal salt etc. are mentioned, 1 type (s) or 2 or more types can be used. The alkali metal salt is, for example, a salt of an alkali metal such as lithium, sodium, or potassium, and examples of the salt include hydroxide, carbonate, bicarbonate, silicate, aluminate, and organic amine salt. . Of these, sodium hydroxide, sodium carbonate, sodium hydrogen carbonate and the like are preferable.

It does not specifically limit as said solvent, Water, an organic solvent, and these mixtures are mentioned, 1 type (s) or 2 or more types can be used. Examples of the organic solvent include alcohol, acetone, dimethyl sulfoxide, dimethylformamide, tetrahydrofuran, dioxane, and the like. Examples of the alcohol include monovalent water-soluble alcohols such as methanol, ethanol, and propanol; 2 such as ethylene glycol and glycerin. Water-soluble alcohol having a valency or higher; The solvent is preferably water, and more preferably ion-exchanged water.

Here, when carbonate is not used as a raw material, or when the generated particles do not satisfy the above formula (1) even when carbonate is used, carbon dioxide gas may be used separately. Carbon dioxide gas may be used in any operation as long as it is in step (I).

In the step (I), when a solvent is used in the neutralization, it is preferable to dry the obtained slurry. This drying may be performed so that the solvent is removed from the slurry, and the drying means is not particularly limited. For example, vacuum drying, heat drying and the like can be mentioned. The slurry may be dried as it is, or may be filtered and washed with water and then dried. In the case of drying after filtration and washing with water, it is also preferred that the slurry is once made into a slurry state and then dried by spray drying.

It is preferable to perform pulverization after the drying. That is, it is preferable that the said process (I) includes the neutralization which neutralizes a raw material in presence of a solvent, the drying of the slurry obtained by this neutralization, and the grinding | pulverization of what was dried. The pulverization method and pulverization conditions are not particularly limited, and may be performed using, for example, a ball mill, a reiki machine, a force mill, a hammer mill, a jet mill, or the like.

The precursor obtained in the step (I) may be in the form of a wet cake (for example, in a state where the solid content measured after drying at 105 ° C. for 18 hours is 15% by mass or more) or in the form of powder. Although it may exist, it is preferable that it is a powder form especially. It is preferable to use the powdery precursor for the step (II) because in the step (II), crystal growth on the plate-like particles further proceeds and excessive aggregation of the primary particles can be suppressed.

When the precursor obtained in the step (I) is in a powder state (powder), the solid content measured by the above method is preferably 85% by weight or more, more preferably 95% by weight or more. preferable.

The precursor has a half width of a peak derived from the (003) plane of 0.4 or more. If the precursor is in a highly crystalline state with a half width of less than 0.4, plate formation does not proceed sufficiently even if it is subjected to step (II), so the average plate surface diameter and aspect ratio are Plate-like hydrotalcite particles that fall within the scope of the present invention cannot be obtained. The half width of the peak derived from the (003) plane of the precursor is preferably 0.5 or more, more preferably 0.6 or more, and still more preferably 0.7 or more. The upper limit is preferably 3 or less. More preferably, it is 2 or less, More preferably, it is 1.2 or less.

The precursor preferably has a half width of a peak derived from the (006) plane of 0.4 or more. More preferably, it is 0.5 or more, More preferably, it is 0.6 or more, Most preferably, it is 0.7 or more. The upper limit is preferably 3 or less. More preferably, it is 2 or less, More preferably, it is 1 or less.
In the present specification, the half width can be determined by an X-ray diffraction method. Specifically, it is calculated | required by the method as described in the Example mentioned later.

The precursor preferably further has a specific surface area of more than 20 m ² / g and 300 m ² / g or less. By providing such a precursor to the step (II), the strength and slipperiness of the obtained plate-like hydrotalcite-type particles and the feeling of application to the skin when included in cosmetics are improved. More preferably, it is 25 m < ² > / g or more, More preferably, it is 30 m < ² > / g or more. The upper limit value of the specific surface area is more preferably 250 m ² / g or less.

<Process (II)>
Step (II) is a step of holding the precursor obtained in the above step (I) in an atmosphere at a temperature of 75 to 150 ° C. and a relative humidity of 75 to 100% RH (also referred to as “wet atmosphere step”). is there. In the above production method, unlike the conventional reaction under hydrothermal or atmospheric pressure, the plate-like hydrotalcite is obtained by a simple means by passing through the process of simply holding the precursor in a high temperature and high humidity atmosphere. Since the mold particles can be obtained, a special device such as a pressure vessel can be dispensed with. That is, the manufacturing equipment can be simplified.

In the step (II), the precursor is held at a temperature of 75 to 150 ° C. From the viewpoint of promoting plate formation, the temperature is preferably 76 ° C. or higher, more preferably 78 ° C. or higher, and still more preferably 80 ° C. or higher. Moreover, it is preferable to set it as 95 degrees C or less from a viewpoint of manufacturing cost or equipment specification.
In the present specification, the holding temperature in the step (II) means the highest temperature reached in the step.
In addition, since the fluctuation | variation of temperature may bring about a change in the crystal growth of a plate-like particle | grain, it is preferable that the difference of the upper limit and the minimum of temperature during holding shall be 10 degrees C or less.

The above step (II) is also performed in an atmosphere having a relative humidity of 75 to 100% RH. From the viewpoint of promoting plate formation, the relative humidity is preferably 76% RH or more, more preferably 77% RH or more, still more preferably 78% RH or more, particularly preferably 79% RH or more, and most preferably 80%. % RH or higher. Moreover, it is preferable to set it as 95% RH or less from a viewpoint of manufacturing cost or equipment specification, More preferably, it is 90% RH or less.
In the present specification, the relative humidity in the step (II) means the maximum reached humidity in the step.
In addition, since the fluctuation | variation of relative humidity may bring about a change in the crystal growth of a plate-like particle | grain, it is preferable to make the difference of the upper limit and the minimum of the humidity under holding | maintenance 10% or less.

The holding time under the above-mentioned conditions may be a time sufficient for the precursor to grow into a plate-like particle. For example, it is preferably 1 to 300 hours. When the holding time is within this range, crystallization proceeds more sufficiently and the productivity is excellent. More preferably, it is 3 to 200 hours, and further preferably 6 to 180 hours.

<Other processes>
In the above production method, in addition to the above-mentioned steps (I) and (II), one or more pulverization, classification, washing, hydrothermal, aging, firing, intercalation of interlayer ions, surface coating, etc., as necessary These steps may be included. Other steps are not particularly limited.

[Use]
The plate-like hydrotalcite-type particles of the present invention are excellent in slipperiness and feel when applied to the skin when included in cosmetics, and are sufficiently reduced in irritation to the skin. It also has excellent compound adsorption performance. Therefore, it can be used for various uses such as cosmetics, pharmaceuticals, quasi drugs, adsorbents, catalysts, and additives for resins. Among them, a cosmetic material that is particularly useful as a cosmetic raw material and includes the plate-like hydrotalcite-type particles is one aspect of the present invention.

The cosmetics contain the plate-like hydrotalcite-type particles of the present invention, the irritation to the skin is reduced, the sliding is good, and the skin feels excellent when applied to the skin. Soft focus effect and sebum adsorption effect can also be expected. Therefore, it is particularly suitable for the needs of the current market. The cosmetic is not particularly limited, and examples thereof include foundations, makeup bases, sunscreens, eye shadows, blushers, mascaras, lipsticks, antiperspirants, and degreased paper. Among these, a foundation is particularly suitable.

In addition to the plate-like hydrotalcite-type particles of the present invention, the cosmetic may contain one or more other components as necessary. Although other components are not specifically limited, For example, the organic solvent and a dispersing agent other than the arbitrary aqueous component and oil-based component normally used in the cosmetics field | area are mentioned. Specifically, oil; surfactant; moisturizer; higher alcohol; sequestering agent; various polymers (natural, semi-synthetic, synthetic or inorganic, water-soluble or oil-soluble polymers); UV screening agent; other Various extractants; Inorganic and organic pigments; Various powders such as inorganic and organic clay minerals; Inorganic and organic pigments treated with metal soap or silicone; Colorants such as organic dyes; Preservatives; Antioxidants A pigment, a thickener, a pH adjuster, a fragrance, a cooling agent, an astringent, a bactericidal agent, a skin activator, and the like. The content of these components is not particularly limited as long as the effects of the present invention are not impaired.

The oil content is not particularly limited. For example, avocado oil, camellia oil, turtle oil, macadamia nut oil, corn oil, mink oil, olive oil, rapeseed oil, egg yolk oil, sesame oil, persic oil, wheat germ oil, southern oil, castor oil , Linseed oil, safflower oil, cottonseed oil, eno oil, soybean oil, peanut oil, tea seed oil, kaya oil, rice bran oil, cinnagari oil, Japanese kiri oil, jojoba oil, germ oil, triglycerin, glyceryl trioctanoate, tri Cured oils such as glyceryl isopalmitate, cocoa butter, coconut oil, horse fat, palm oil, beef tallow, sheep tallow, palm kernel oil, pork tallow, beef bone fat, owl kernel oil, hydrogenated beef tallow, hydrogenated palm oil, hydrogenated castor oil , Beef leg fat, mole, beeswax, candelilla wax, cotton wax, carnauba wax, bayberry wax, ibotarou, whale wax, montan wax, nukarou, la Phosphorus, kapok wax, lanolin acetate, liquid lanolin, sugar cane wax, lanolin fatty acid isopropyl, hexyl laurate, reduced lanolin, jojoballow, hard lanolin, shellac wax, POE lanolin alcohol ether, POE lanolin alcohol acetate, POE cholesterol ether, lanolin fatty acid polyethylene glycol POE hydrogenated lanolin alcohol ether, liquid paraffin, ozokerite, pristane, paraffin, ceresin, squalene, petrolatum, microcrystalline wax and the like.

Examples of the surfactant include lipophilic nonionic surfactants, hydrophilic nonionic surfactants, and other surfactants. The lipophilic nonionic surfactant is not particularly limited. For example, sorbitan monooleate, sorbitan monoisostearate, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan sesquioleate, sorbitan trioleate Sorbitan fatty acid esters such as diglycerol sorbitan penta-2-ethylhexylate, diglycerol sorbitan tetra-2-ethylhexylate, mono-cotton oil fatty acid glycerin, glyceryl monoerucate, glyceryl sesquioleate, glyceryl monostearate, α, α ' -Glycerol polyglycerol fatty acids such as glyceryl oleate, glycerol monostearate, malic monostearate, propylene glycol such as propylene glycol monostearate Examples include recall fatty acid esters, hardened castor oil derivatives, and glycerin alkyl ethers.

The hydrophilic nonionic surfactant is not particularly limited. For example, POE sorbitan fatty acid esters such as POE sorbitan monooleate, POE sorbitan monostearate, POE sorbitan tetraoleate, POE sorbite monolaurate, and POE sorbite mono POE sorbite fatty acid esters such as oleate, POE sorbite pentaoleate, POE sorbite monostearate, POE glycerin fatty acid esters such as POE glycerol monostearate, POE glycerol monoisostearate, POE glycerol triisostearate, POE POE fatty acid esters such as monooleate, POE distearate, POE monodiolate, ethylene glycol stearate, POE lauryl ether, POE POE alkyl ethers such as yl ether, POE stearyl ether, POE behenyl ether, POE 2-octyldodecyl ether, POE cholestanol ether, POE alkyl phenyl ethers such as POE octyl phenyl ether, POE nonyl phenyl ether, POE dinonyl phenyl ether Plu-alonic types such as brulonic, POE / POP cetyl ether, POE / POP2-decyltetradecyl ether, POE / POP monobutyl ether, POE / POP hydrogenated lanolin, POE / POP alkyl ethers such as POE / POP glycerin ether, Tetronic PEO / TetraPOP ethylenediamine condensates, POE castor oil, POE hydrogenated castor oil, POE hydrogenated castor oil monoisos POE castor oil triisostearate, POE cured castor oil monopyroglutamic acid monoisostearic acid diester, POE castor oil cured castor oil derivatives such as POE cured castor oil maleic acid, POE beeswax and lanolin derivatives such as POE sorbite beeswax, Alkanolamides such as coconut oil fatty acid diethanolamide, lauric acid monoethanolamide, fatty acid isopropanolamide, POE propylene glycol fatty acid ester, POE alkylamine, POE fatty acid amide, sucrose fatty acid ester, POE nonylphenyl formaldehyde condensate, alkylethoxydimethylamine Examples thereof include oxide and trioleyl phosphate.

Examples of other surfactants include anionic surfactants such as fatty acid soaps, higher alkyl sulfates, POE lauryl sulfate triethanolamine, alkyl ether sulfates, alkyltrimethylammonium salts, alkylpyridinium salts, alkyl quaternary salts. Examples thereof include cationic surfactants such as ammonium salts, alkyldimethylbenzylammonium salts, POE alkylamines, alkylamine salts, and polyamine fatty acid derivatives, amphoteric surfactants such as imidazoline-based amphoteric surfactants, and betaine-based surfactants.

The moisturizing agent is not particularly limited, and for example, xylitol, sorbitol, maltitol, chondroitin sulfate, hyaluronic acid, mucoitin sulfate, caronic acid, atelocollagen, cholesteryl-12-hydroxystearate, sodium lactate, bile salt, dl-pyrrolidone Examples thereof include carboxylate, short-chain soluble collagen, diglycerin (EO) PO adduct, Izayoi rose extract, yarrow extract, and merirot extract.

The higher alcohol is not particularly limited, and examples thereof include linear alcohols such as lauryl alcohol, cetyl alcohol, stearyl alcohol, behenyl alcohol, myristyl alcohol, oleyl alcohol, cetostearyl alcohol, monostearyl glycerin ether (batyl alcohol), 2-decyltetra Examples thereof include branched chain alcohols such as decinol, lanolin alcohol, cholesterol, phytosterol, hexyldodecanol, isostearyl alcohol, and octyldodecanol.

The sequestering agent is not particularly limited. For example, 1-hydroxyethane-1,1- diphosphonic acid, 1-hydroxyethane-1,1-diphosphonic acid tetrasodium salt, sodium citrate, sodium polyphosphate, metaphosphoric acid Examples thereof include sodium, gluconic acid, phosphoric acid, citric acid, ascorbic acid, succinic acid, edetic acid and the like.

The natural water-soluble polymer is not particularly limited. For example, gum arabic, gum tragacanth, galactan, guar gum, carob gum, caraya gum, carrageenan, pectin, agar, quince seed (malmello), algae colloid (gypsum extract), starch (rice, Corn, potato, wheat), plant polymers such as glycyrrhizic acid, microbial polymers such as xanthan gum, dextran, succinoglucan and pullulan, and animal polymers such as collagen, casein, albumin and gelatin. .

The semi-synthetic water-soluble polymer is not particularly limited. For example, starch-based polymers such as carboxymethyl starch and methylhydroxypropyl starch, methylcellulose, nitrocellulose, ethylcellulose, methylhydroxypropylcellulose, hydroxyethylcellulose, sodium cellulose sulfate, Examples thereof include cellulose polymers such as hydroxypropylcellulose, sodium carboxymethylcellulose (CMC), crystalline cellulose and cellulose powder, and alginic acid polymers such as sodium alginate and propylene glycol alginate.

The synthetic water-soluble polymer is not particularly limited, and examples thereof include vinyl polymers such as polyvinyl alcohol, polyvinyl methyl ether, and polyvinyl pyrrolidone, polyoxyethylene polymers such as polyethylene glycol 20000, 40000, and 60000, and polyoxyethylene. Examples include polyoxypropylene copolymer copolymer polymers, acrylic polymers such as sodium polyacrylate, polyethyl acrylate, and polyacrylamide, polyethyleneimine, and cationic polymers.

The inorganic water-soluble polymer is not particularly limited, and examples thereof include bentonite, silicate A1Mg (beegum), laponite, hectorite, and silicic anhydride.

The UV screening agent is not particularly limited. For example, paraaminobenzoic acid (hereinafter abbreviated as PABA), PABA monoglycerin ester, N, N-dipropoxy PABA ethyl ester, N, N-diethoxy PABA ethyl ester, N, N-dimethyl Benzoic acid UV screening agents such as PABA ethyl ester and N, N-dimethyl PABA butyl ester; Anthranilic acid UV screening agents such as homomenthyl-N-acetylanthranylate; Amyl salicylate, Menthyl salicylate, Homomentil salicylate, Octyl salicylate , Salicylic acid UV screening agents such as phenyl salicylate, benzyl salicylate, p-isopropanol phenyl salicylate; octylcinnamate, ethyl-4-isopropylcinnamate, methyl-2,5- Isopropyl cinnamate, ethyl-2,4-diisopropyl cinnamate, methyl-2,4-diisopropyl cinnamate, propyl-p-methoxycinnamate, isopropyl-p-methoxycinnamate, isoamyl-p-methoxycinnamate, 2- Ethoxyethyl-p-methoxycinnamate, cyclohexyl-p-methoxycinnamate, ethyl-α-cyano-β-phenylcinnamate, 2-ethylhexyl-α-cyano-β-phenylcinnamate, glyceryl mono-2-ethylhexa Cinnamic acid-based UV screening agents such as noyl-diparamethoxycinnamate; 2,4-dihydroxybenzophenone, 2,2′-dihydroxy-4-methoxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone , 2, 2 ', 4,4'-tetrahydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-4'-methylbenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonate, 4 -Benzophenone-based UV screening agents such as phenylbenzophenone, 2-ethylhexyl-4'-phenyl-benzophenone-2-carboxylate, 2-hydroxy-4-n-octoxybenzophenone, 4-hydroxy-3- carboxybenzophenone; (4'-methylbenzylidene) -d, l-camphor, 3-benzylidene-d, l-camphor, urocanic acid, urocanic acid ethyl ester, 2-phenyl-5-methylbenzoxazole, 2,2'-hydroxy- 5-methylphenylbenzoto Azole, 2- (2′-hydroxy-5′-t-octylphenyl) benzotriazole, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, dibenzalazine, dianisoylmethane, 4-methoxy-4 ′ -T-butyldibenzoylmethane, 5- (3,3-dimethyl-2-norbornylidene) -3-pentan-2-one and the like.

Other drug components are not particularly limited and include, for example, vitamin A oil, retinol, retinol palmitate, inosit, pyridoxine hydrochloride, benzyl nicotinate, nicotinamide, nicotinic acid DL-α-tocopherol, magnesium ascorbate phosphate, 2 Vitamins such as -O-α-D-glucopyranosyl-L-ascorbic acid, vitamin D2 (ergocaciferol), dl-α-tocopherol, dl-α-tocopherol acetate, pantothenic acid, biotin; estradiol, ethinylestradiol, etc. Hormones; amino acids such as arginine, aspartic acid, cystine, cysteine, methionine, serine, leucine and tryptophan; anti-inflammatory agents such as allantoin and azulene; whitening agents such as arbutin; astringents such as tannic acid; L Menthol, cooling agents of camphor; and, sulfur, lysozyme chloride, pyridoxine chloride.

There are no particular limitations on the various extracts, for example, Dokudami extract, Oat extract, Merirot extract, Odorikosou extract, Licorice extract, Peonies extract, Soap extract, Loofah extract, Kina extract, Yukinoshita extract, Clara extract, Kouhone extract, Fennel Extract, Primrose Extract, Rose Extract, Giant Extract, Lemon Extract, Shikon Extract, Aloe Extract, Shobu Root Extract, Eucalyptus Extract, Horsetail Extract, Sage Extract, Thyme Extract, Tea Extract, Seaweed Extract, Cucumber Extract, Clove Extract, Raspberry Extract, Melissa Extract , Carrot extract, horse chestnut extract, peach extract, peach leaf extract, mulberry extract, cornflower extract, hamamelis extract, placenta extract, thymus extract, silk extract, licorice Kiss, and the like.

Various powders include, for example, bengara, yellow iron oxide, black iron oxide, mica titanium, iron oxide coated mica titanium, titanium oxide coated glass flakes and other bright colored pigments, mica, talc, kaolin, sericite, titanium dioxide. Inorganic powders such as silica and organic powders such as polyethylene powder, nylon powder, cross-linked polystyrene, cellulose powder, and silicone powder. Preferably, a part or all of the powder component is hydrophobized by a known method with substances such as silicones, fluorine compounds, metal soaps, oil agents, acyl glutamates in order to improve sensory characteristics and cosmetic durability. Is.

In order to describe the present invention in detail, examples will be given below, but the present invention is not limited to these examples. Unless otherwise specified, “%” means “% by weight (mass%)”.

Example 1
(1) 96.6 g of neutralized zinc sulfate heptahydrate and 81.2 mL of 354 g / L aluminum sulfate aqueous solution (28.7 g as Al ₂ (SO ₄ ) ₃ ) are mixed so that the total amount becomes 350 mL A metal salt mixed aqueous solution to which ion exchange water was added was obtained. Separately, 46.7 mL of a 720 g / L sodium hydroxide aqueous solution and 26.7 g of sodium carbonate were mixed to obtain an alkali mixed aqueous solution to which ion-exchanged water was added so that the total amount became 350 mL. In a 1 L round bottom flask, 50 mL of ion exchange water was added, and these aqueous solutions were added under stirring. The pH of the slurry at this time was 9. Then, the slurry was obtained by stirring for 30 minutes at 50 degreeC.

(2) Drying and pulverization The slurry obtained by the above “(1) neutralization” was filtered and washed with water until the electric conductivity of the washing liquid became 100 μS / cm or less. The obtained cake was dried at a temperature of 105 ° C. for 18 hours, and 5 g of the dried powder was pulverized for 20 seconds with a force mill (manufactured by Osaka Chemical Co., Ltd., FM-1) to obtain hydrotalcite precursor powder. .

(5) Wet atmosphere process 1 g of the powder obtained by the above “(2) Drying and pulverization” is placed in a glass petri dish having an inner diameter of 27 mm and a height of 15 mm, and a constant temperature and humidity chamber (manufactured by Espec Corp., PR- 1 KT), adjusted from room temperature to 85 ° C. and relative humidity 85% RH over 15 minutes, held at 85 ° C. and relative humidity 85% RH for 3 hours, then stopped energizing the heater and cooled to room temperature . In addition, this process was performed in air | atmosphere. In this way, a powder (1) containing hydrotalcite type particles was obtained.

Examples 2 to 6
In Example 1, powders (2) to (2) containing hydrotalcite-type particles were obtained in the same manner as in Example 1 except that the retention time in “(5) Wet atmosphere process” was changed as shown in Table 1. 6) were obtained respectively.

Examples 7-11
In Example 1, the reaction time in “(1) neutralization” (that is, the stirring time at 50 ° C.) was 10 minutes, and the retention time in “(5) wet atmosphere process” was as shown in Table 1. Except for the changes, powders (7) to (11) containing hydrotalcite-type particles were obtained in the same manner as in Example 1.

Example 12
The hydrotalcite precursor slurry obtained by “(1) Neutralization” in Example 10 was filtered and washed with water until the electric conductivity of the washing liquid became 100 μS / cm or less. When the obtained cake 3.3 g (solid content 30%) was subjected to the “(5) wet atmosphere step”, it was as shown in Table 1. Thus, a powder (12) containing hydrotalcite type particles was obtained.

Examples 13 and 14
(3) Maturation The slurry obtained by “(1) Neutralization” in Example 7 was weighed into a 1 L round bottom flask so as to be 42 g in terms of solid content in the slurry, so that the total amount became 600 mL. After adding ion-exchange water, it stirred at 50 degreeC for 22 hours. This slurry was filtered and washed with water until the electric conductivity of the washing liquid became 100 μS / cm or less. The obtained cake was dried at a temperature of 105 ° C. for 18 hours, and 5 g of the dried powder was pulverized with a force mill (FM-1 manufactured by Osaka Chemical Co., Ltd.) for 20 seconds to obtain hydrotalcite precursor powder. It was. 1 g of the obtained powder was subjected to “(5) Wet atmosphere process” in Example 1 (however, the holding time was changed as shown in Table 1). In this way, powders (13) and (14) containing hydrotalcite-type particles were obtained.

Comparative Example 1
(1) Neutralization 297 g / L magnesium sulfate heptahydrate 136.2 mL (40.5 g as MgSO ₄ ) and 354 g / L aluminum sulfate aqueous solution 81.2 mL (Al ₂ (SO ₄ ) ₃ as 28.7 g ) To obtain a metal salt mixed aqueous solution to which ion exchange water was added so that the total amount became 350 mL. Separately, 46.7 mL of a 720 g / L sodium hydroxide aqueous solution and 26.7 g of sodium carbonate were mixed to obtain an alkali mixed aqueous solution to which ion-exchanged water was added so that the total amount became 350 mL. In a 1 L round bottom flask, 50 mL of ion exchange water was added, and these aqueous solutions were added under stirring. The pH of the slurry at this time was 9. Then, the slurry of the hydrotalcite precursor was obtained by stirring for 30 minutes at 50 degreeC.

(2) Drying and pulverization The slurry obtained by the above “(1) neutralization” was filtered and washed with water until the electric conductivity of the washing liquid became 100 μS / cm or less. The obtained cake was dried at a temperature of 105 ° C. for 18 hours, and 5 g of the dried powder was pulverized for 20 seconds with a force mill (manufactured by Osaka Chemical Co., Ltd., FM-1) to obtain hydrotalcite precursor powder. . 1 g of the obtained powder was subjected to “(5) Wet atmosphere process” in Example 1 (however, the holding time was changed as shown in Table 2). In this way, a powder (c1) containing hydrotalcite-type particles was obtained.

Comparative Example 2
In Comparative Example 1, except that the Mg raw material used in “(1) Neutralization” was changed to the Zn raw material and the Mg raw material shown in Table 2, the slurry obtained in the same manner as in Comparative Example 1 was filtered and washed. Was washed with water until the electric conductivity of the sample became 100 μS / cm or less. The obtained cake was dried at a temperature of 105 ° C. for 18 hours, and 5 g of the dried powder was pulverized with a force mill (FM-1 manufactured by Osaka Chemical Co., Ltd.) for 20 seconds to obtain hydrotalcite precursor powder. It was. 1 g of the obtained powder was subjected to “(5) Wet atmosphere process” in Example 1 (however, the holding time was changed as shown in Table 2). In this way, a powder (c2) containing hydrotalcite-type particles was obtained.

Comparative Example 3
A powder (c3) containing hydrotalcite-type particles was obtained in the same manner as in Example 1 except that “(5) Wet atmosphere process” was not performed in Example 1.

Comparative Examples 4 and 6
In Example 1, except that the Zn raw material used in “(1) Neutralization” was changed to the Zn raw material and Mg raw material shown in Table 2, and “(5) Wet atmosphere process” was not performed. In the same manner as in Example 1, powders (c4) and (c6) containing hydrotalcite-type particles were obtained.

Comparative Examples 5 and 7
In Example 1, the Zn raw material used in “(1) Neutralization” was changed to the Zn raw material and the Mg raw material shown in Table 2, and the relative humidity and holding time in “(5) Wet atmosphere process” are shown in Table 2. Powders (c5) and (c7) containing hydrotalcite-type particles were obtained in the same manner as in Example 1 except that the changes were made as described in 1.

Comparative Examples 8, 10-12
A powder containing hydrotalcite-type particles in the same manner as in Example 1, except that the temperature, relative humidity and holding time in “(5) Wet atmosphere process” in Example 1 were changed as shown in Table 2. (C8) and (c10) to (c12) were obtained.

Comparative Example 9
(4) The slurry obtained by “(1) neutralization” in hydrothermal example 1 is weighed into a 100 mL pressure vessel so that the amount is 5.3 g in terms of solid content in the slurry, and the total amount becomes 75 mL. After adding ion-exchanged water, the mixture was kept at 180 ° C. for 2 hours. The slurry was filtered, and washed with water until the electric conductivity of the washing liquid became 100 μS / cm or less to obtain a cake. The obtained cake was dried at a temperature of 105 ° C. for 18 hours, and 5 g of the dried powder was pulverized with a force mill (manufactured by Osaka Chemical Co., FM-1) for 20 seconds to obtain a powder (c9). Since most were zinc oxide, the below-mentioned evaluation was not performed.

Comparative Example 13
(1) 96.6 g of neutralized zinc sulfate heptahydrate and 81.2 mL of 354 g / L aluminum sulfate aqueous solution (28.7 g as Al ₂ (SO ₄ ) ₃ ) are mixed so that the total amount becomes 350 mL A metal salt mixed aqueous solution to which ion exchange water was added was obtained. Separately, 46.7 mL of a 720 g / L sodium hydroxide aqueous solution and 26.7 g of sodium carbonate were mixed to obtain an alkali mixed aqueous solution to which ion-exchanged water was added so that the total amount became 350 mL. In a 1 L round bottom flask, 50 mL of ion exchange water was added, and these aqueous solutions were added under stirring. The pH of the slurry at this time was 9. Then, the slurry was obtained by stirring for 10 minutes at 50 degreeC.

(3) Aging The slurry obtained by the above “(1) Neutralization” is weighed into a 1 L round bottom flask so that the amount is 42 g in terms of solid content in the slurry, and ion-exchanged water so that the total amount becomes 600 mL. Then, the mixture was stirred at 50 ° C. for 22 hours. This slurry was filtered and washed with water until the electric conductivity of the washing liquid became 100 μS / cm or less. The obtained cake was dried at a temperature of 105 ° C. for 18 hours, and 5 g of the dried powder was pulverized with a force mill (manufactured by Osaka Chemical Co., FM-1) for 20 seconds to obtain a powder containing hydrotalcite-type particles ( c13) was obtained.

Comparative Example 14
In Example 7, a powder (c14) containing hydrotalcite-type particles was obtained in the same manner as in Example 7, except that “(5) Wet atmosphere process” was not performed.

Comparative Example 15
In Comparative Example 13, a cake was obtained in the same manner as Comparative Example 13 except that the aging temperature (50 ° C.) in “(3) Aging” was changed to 85 ° C. The obtained cake was dried at a temperature of 105 ° C. for 18 hours, and 5 g of the dried powder was pulverized with a force mill (manufactured by Osaka Chemical Co., FM-1) for 20 seconds to obtain a powder containing hydrotalcite-type particles ( c15) was obtained.

Comparative Examples 16 and 17
1 g of the hydrotalcite powder obtained in “(3) Aging” in Comparative Example 15 was subjected to “(5) Wet atmosphere process” in Example 1 (however, the holding time was as shown in Table 2). changed). In this way, powders (c16) and (c17) containing hydrotalcite-type particles were obtained.

Comparative Example 18
In Comparative Example 13, a cake was obtained in the same manner as Comparative Example 13 except that the aging temperature (50 ° C.) in “(3) Aging” was changed to 100 ° C. The obtained cake was dried at a temperature of 105 ° C. for 18 hours, and 5 g of the dried powder was pulverized with a force mill (manufactured by Osaka Chemical Co., FM-1) for 20 seconds to obtain a powder containing hydrotalcite-type particles ( c18) was obtained.

Reference example 1
For reference, commercially available hydrotalcite compounds (STABIACE.HT-1-NC, (Mg) _0.67 (Al) _0.33 (OH) ₂ (CO ₃ ²⁻ ) _0.17 · 0. 5H ₂ O (manufactured by Sakai Chemical Industry Co., Ltd.) was used as the powder of Reference Example 1 (hydrotalcite-type particles obtained in Reference Example 1).

Hydrotalcite-type particles (powder) obtained in each of the examples and comparative examples, and precursors used in “(5) Wet atmosphere process” (generated when “(5) Wet atmosphere process” is not performed) The physical properties were measured and evaluated according to the following methods.

1. Measurement of half width The powder X-ray diffraction pattern (also simply referred to as X-ray diffraction pattern) was measured for each of the obtained powders under the following conditions. For example, the X-ray diffraction pattern of the powder obtained in Example 11 is shown in FIG. Thereafter, the (003) and (006) half-value widths were measured from the diffraction patterns obtained by X-ray diffraction measurement of the obtained powders. The results are shown in Tables 3 and 4.
The X-ray diffraction patterns of all the powders obtained in the examples were in agreement with JCPDS card 00-048-1023.

-Analysis conditions-
Machine used: RINT-UltimaIII manufactured by Rigaku
Radiation source: CuKα
Voltage: 50kV
Current: 300mA
Sample rotation speed: 60 rpm
Divergence slit: 1.00mm
Divergence length restriction slit: 10 mm
Scattering slit: Open light receiving slit: Open scanning mode: FT
Counting time: 2.0 seconds Step width: 0.0200 °
Operation axis: 2θ / θ
Scanning range: 1.6000 to 70.000 °
Accumulation count: 1 times The following materials were used to identify hydrotalcite-type particles.
Zn _0.67 Al _0.33 (OH) ₂ (CO ₃ ) _0.165 · xH ₂ O: JCPDS card 00-048-1023
Mg ₄ Al ₂ (OH) ₁₂ CO ₃ / 3H ₂ O: JCPDS card 00-051-1525
In X-ray diffraction using CuKα rays as a radiation source, the peak derived from the (003) plane, which is the maximum peak of hydrotalcite, is near 2θ = 11.6 °, and the peak derived from the (006) plane is It is around 2θ = 23.4 °.

2. Measurement of specific surface area (SSA) The specific surface area (SSA) was measured under the following conditions. The results are shown in Tables 3 and 4.
Used machine: Macsorb Model HM-1220, manufactured by Mountec
Atmosphere: Nitrogen gas (N ₂ )
Degassing condition of external degassing device: 105 ° C-15 minutes Degassing condition of specific surface area measuring device body: 105 ° C-5 minutes

3. Median diameter (D ₅₀ ) and sharpness of particle size distribution (D ₉₀ / D ₁₀ )
The particle size distribution was measured with a laser diffraction / scattering particle size analyzer (manufactured by HORIBA, model number: LA-950-V2).
First, 60 mL of a 0.025 wt% sodium hexametaphosphate aqueous solution was added to 0.1 g of a sample (sample powder), and the strength was set to V-LEVEL 3 using an ultrasonic homogenizer (US-600, manufactured by Nippon Seiki Seisakusho). A sample suspension was prepared by performing a dispersion treatment for a minute. Thereafter, an aqueous 0.025 wt% sodium hexametaphosphate solution is circulated through the sample circulator, and the suspension is added dropwise so that the transmittance is 80 to 95%. Measurement was performed after ultrasonic dispersion for 2 seconds. The results are shown in Tables 3 and 4.

4. Elemental analysis The Mg, Zn and Al contents in hydrotalcite can be measured by the following method using inductively coupled plasma (ICP) emission spectroscopy.
Specifically, a spectroscope (manufactured by SII, ICP SPS3100) is used as follows, and measurement is performed by an internal standard method using scandium (Sc) as an internal standard element.
First, about 0.2 g of a sample is precisely weighed in a beaker, about 5 mL of hydrochloric acid is added and dissolved, filled into a 100 mL volumetric flask, and made up with ion-exchanged water. This was diluted 20 times for Mg content measurement, 50 times for Zn content measurement, 10 times for Al content measurement, and diluted with Sc standard solution so that the Sc concentration would be 10 ppm. The Mg, Zn and Al contents are calculated by measuring under the following measurement conditions and calculating the obtained raw data under the following calculation conditions. The results are shown in Tables 3 and 4.

-Measurement condition-
Using a spectroscope (ICP SPS3100, manufactured by SII), calibration curves were prepared at wavelengths of 279.55 nm (Mg), 213.86 nm (Zn), 396.15 nm (Al), and 361.49 nm (Sc), respectively. After that, the sample is measured.
As the concentration of the calibration curve sample,
Mg (ppm) = 50, 40, 30, 20, 10,
Zn (ppm) = 20, 16, 12, 8, 4,
Al (ppm) = 50, 40, 30, 20, 10
5 points are used.
In all the calibration curve samples, the Sc standard solution was added so that the Sc concentration was 10 ppm. The calculation conditions are as follows.
Each content (%) = raw data × 100 / sample weight (g) × dilution ratio / 10000

Also, using the Mg, Zn, Al content (% by weight) determined as described above, the following calculation formula:
x = (Al content / 26.982) ÷ {(Mg content / 24.305) + (Zn content / 65.38) + (Al content / 26.982)}
Thus, a value corresponding to x in the above formula (1) was obtained. The results are shown in Tables 3 and 4.

5. Measurement was performed using an automatic pore volume specific surface area / pore distribution measuring device (product name “BEL SORP-miniII”, manufactured by Nippon Bell Co., Ltd.). A measurement cell was filled with 0.1 g of a sample and subjected to degassing treatment at 200 ° C., and measurement was performed.
The BJH method is used as an analysis method for calculating the average pore diameter, the total pore volume, and the pore distribution.
The average pore diameter is a value obtained by dividing 4 times the total pore volume by the surface area. This assumes that all the pores in the sample are cylindrical, and that the cylindrical pores have a volume V. At this time, the volume of the cylindrical pore is represented by the following formula (i).
V = πD ² L / 4 (i)
In the formula, D is the pore diameter, and L is the length of the cylindrical pore.
Next, the side area A of the cylindrical pore is expressed by the following formula (ii).
A = πDL (ii)
From the above formulas (i) and (ii), the following formula (iii) is obtained.
D = 4V / A (iii)
Let D calculated by the above formula (iii) be the average pore diameter.
The total pore volume is an integrated value of pores in the entire range obtained from the pore distribution result by the BJH method. The results are shown in Tables 3 and 4.

6. Take an electron micrograph of the average plate surface diameter, average thickness, and aspect ratio powder using a field emission scanning electron microscope (JSM-7000F, manufactured by JEOL Ltd.) so that about 50 to 10,000 particles can be seen. did. The average value of the plate surface diameters of 20 particles on a straight line randomly drawn on this electron micrograph was taken as the average plate surface diameter of each powder. The average thickness (average value of the thickness of 20 particles) was calculated by the same method, and the aspect ratio was determined by (average plate surface diameter / average thickness). When it was difficult to measure the plate surface diameter and thickness, the measurement was carried out using a photograph taken at an appropriately increased magnification. This operation was repeated 10 times by changing the powder to be photographed for each example and comparative example, and the average value of the obtained aspect ratios was calculated. The results are shown in Tables 3 and 4. In addition, when the average plate surface diameter and average thickness were calculated for the powders obtained in the examples, the standard deviation of the average plate surface diameter and the average thickness (the square root of the value obtained by averaging the square of the difference from the average value) at the same time And its coefficient of variation (value obtained by dividing the standard deviation by the average value). The results are shown in Table 3.

7. Pigment pH
The pigment pH of each powder was measured by the following method based on the pigment test method of “JIS K5101-17-1: 2004”.
5 g of sample was put into 50 g of distilled water in a glass container with a stopper, and after boiling for about 5 minutes with the stopper removed, the mixture was further boiled for 5 minutes. After boiling, the bottle was stoppered and allowed to cool to room temperature, then the stopper was opened, distilled water corresponding to the weight loss was added, stoppered again, shaken for 1 minute, and allowed to stand for 5 minutes. The stopper was removed and the pH was measured with a pH meter. The results are shown in Tables 3 and 4.

8. Oil absorption The oil absorption was measured using isopropyl myristate by the following method in accordance with JIS K5101-13-1 (2004).
About 0.5 g of the sample is precisely weighed on the medicine wrapping paper, and the sample is placed on the ground glass portion of the center 10 cm of the glass plate. Add isopropyl myristate (referred to as “IPM”) to a microburette, add 0.2 mL dropwise to the sample, and knead with a gold spatula. Then, add 1-2 drops of IPM and knead the whole with a gold spatula each time. The end point is when the whole becomes a hard putty-like lump for the first time.
The oil absorption was calculated by the following formula. The results are shown in Table 3 (and 4).
Oil absorption (ml / 100 g) = {V (mL) ÷ sample weight (g)} × 100

9, slipperiness (MIU, MMD)
Evaluation of slipperiness of each sample was performed by the following method.
Double-sided tape was affixed to the slide glass, about half a spoonful of powder (sample) was placed on the adhesive surface, the powder was spread with a cosmetic sponge, and a friction piece was set thereon. The slide glass was moved, and the average friction coefficient MIU and the variation value MMD of the average friction coefficient were measured from the load applied to the friction element. The measurement was performed with a friction tester (KES-SE, manufactured by Kato Tech).
For comparison, plate-like barium sulfate · H (manufactured by Sakai Chemical Industry Co., Ltd.) and STABIACE · HT-1NC (manufactured by Sakai Chemical Industry Co., Ltd.) (Reference Example 1), which is a commercially available hydrotalcite compound, were used.
The average friction coefficient MIU of plate-like barium sulfate · H is 0.64, the variation value MMD of the average friction coefficient is 0.0103, the average friction coefficient MIU of STABIACE · HT-1NC is 0.897, and the variation of the average friction coefficient The value MMD was 0.047.
The average friction coefficient MIU is an index indicating that the powder is slippery as the numerical value is small, and the variation value MMD of the friction coefficient is an index indicating that the numerical value is smooth and free from roughness. The results are shown in Table 3 (and 4).

10. Evaluation as cosmetics (sensory evaluation)
(1) First, hydrotalcite 20.00% by weight obtained in Examples and Comparative Examples, mica (product name: Y-2300X, manufactured by Yamaguchi Mica) 24.83% by weight, sericite (product name: FSE, Sanshin Mining Co., Ltd.) 29.79% by weight, spherical silicone (Product name: KSP-105, Shin-Etsu Chemical Co., Ltd.) 6.44% by weight, titanium oxide (Product name: R-3LD, Sakai Chemical Industry Co., Ltd.) 7.36% by weight, iron oxide (yellow) (product name: yellow iron oxide, manufactured by Pinoa) 1.10% by weight, iron oxide (red) (product name: Bengala, manufactured by Pinoa) 0.37% by weight, Metal soap (product name: JPM-100, manufactured by Sakai Chemical Industry Co., Ltd.) 0.92% by weight and oil (product name: KF96, manufactured by Shin-Etsu Chemical Co., Ltd.) 9.20% by weight were added to a coffee mill. Stir and mix for 30 minutes.
The obtained powdery mixture was weighed 0.8 g in a 20 mmφ diameter mold and held for 30 seconds at a pressure of 200 kgf / cm ² using a press machine to prepare a hydrotalcite-containing foundation. .

(2) For comparison, mica (product name: Y-2300X, manufactured by Yamaguchi Mica) 31.03% by weight, sericite (product name: FSE, manufactured by Sanshin Mining Co., Ltd.) 37.24% by weight, spherical silicone (Product name: KSP-105, manufactured by Shin-Etsu Chemical Co., Ltd.) 8.05% by weight, titanium oxide (Product name: R-3LD, manufactured by Sakai Chemical Industry Co., Ltd.) 9.20% by weight, iron oxide (yellow) (Product name) : Yellow iron oxide (Pinoa) 1.38 wt%, Iron oxide (red) (Product name: Bengala, Pinoa) 0.46 wt%, Metal soap (Product name: JPM-100, Sakai Chemical Industry Co., Ltd.) 1.15% by weight and oil (product name: KF96, manufactured by Shin-Etsu Chemical Co., Ltd.) 11.49% by weight were stirred and mixed using a coffee mill for 1 minute 30 seconds.
0.8 g of the obtained powdery mixture is measured in a 20 mmφ diameter mold and is held for 30 seconds at a pressure of 200 kgf / cm ² using a press machine to produce a hydrotalcite-free foundation. did.

(3) The foundation obtained in (1) and (2) above was applied to 10 panelists, and the skin touch when it was included in cosmetics was selected according to the criteria shown below. did. The test was conducted blind. The evaluation results are shown in Tables 3 and 4.
(Evaluation criteria for coating feel)
A: The use feeling of the hydrotalcite-containing foundation (1) above is better than the use of the hydrotalcite-free foundation (2) above.
○: Both have the same coating feel.
X: The use feeling of the hydrotalcite-free foundation of the above (2) has a better coating feel than the use of the hydrotalcite-containing foundation of the above (1).

11. SEM image The shape of the particles was observed with a field emission scanning electron microscope (manufactured by JEOL Ltd., JSM-7000F). Electron micrographs of the powder obtained in Example 11 are shown in FIGS. 2-1 to 2-4.

12. Phosphorus compound adsorption rate in aqueous solution To 100 g of a solution adjusted to a phosphate ion concentration of 50, 25, and 5 ppm using potassium hydrogen phosphate, 1 g of a sample was added and stirred for a predetermined time, followed by filtration. The phosphate ion concentration of the solution was measured with an ion chromatograph (manufactured by Dionex, model number: ICS-2000). The phosphate ion concentrations measured over time for the case where the powder obtained in Example 11 is used are shown in FIGS. 3-1, 3-2 and 3-3. In these drawings, for comparison, the phosphate ion concentration over time when the powder of Reference Example 1 was used is also shown.
The phosphorus compound adsorption rate for the blank after elapse of a time was calculated by the following formula.
Phosphorus compound adsorption ratio (%) = 100 × (phosphate ion concentration of blank after elapse of a time−phosphate ion concentration of evaluation sample (sample) after elapse of a time) / (blank phosphoric acid after elapse of a time) Ion concentration)
It should be noted that the phosphate ion concentration of the blank after elapse of time a is stirred for a predetermined time without putting an evaluation sample in 100 g of a solution prepared by adjusting the phosphate ion concentration to 50, 25, 5 ppm using potassium hydrogen phosphate. , The phosphate ion concentration of the filtered solution after a time has elapsed. After 1 hour, 2 hours, and 4 hours, the blank phosphate ion concentrations were 50 ppm, 25 ppm, and 5 ppm, respectively, which were the same as the initial values.

13. Ammonia gas adsorption rate 1.0 g of each sample powder was put in a 5 L sampling bag (manufactured by GL Science Co., Ltd.), and a 5 L sampling bag without a sample was also prepared as a blank. After 3 L of nitrogen gas containing 100 ppm of ammonia was injected into the sampling bag, it was immediately sealed and allowed to stand for 1 hour at 20 ° C. and 65% humidity. After standing, 100 mL of gas in the sampling bag was sucked with a suction device, and the concentration of ammonia was measured with a detector tube (No. 3La) manufactured by Gastec. FIG. 4 shows changes with time in the ammonia concentration when the powder obtained in Example 11 was used. For comparison, FIG. 4 also shows the change over time in the ammonia concentration when the powders obtained in Comparative Example 18 and Reference Example 1 were used.
The ammonia gas adsorption rate with respect to the blank was calculated by the following formula.
Ammonia gas adsorption rate (%) = 100 × (blank ammonia concentration−ammonia concentration of evaluation sample) / (blank ammonia concentration)
In addition, the ammonia concentration of the blank is the ammonia concentration measured after sealing a sampling bag containing only 3 L of nitrogen gas containing 100 ppm of ammonia without putting an evaluation sample and allowing to stand for 1 hour. The ammonia concentration in the blank was 100 ppm.

14. Differential Heat / Thermogravimetry Measurement The powder of Example 11 and Reference Example 1 was subjected to differential heat / thermogravimetry (TG / DTA). Specifically, differential heat / thermogravimetry (TG / DTA) was performed under the following conditions. The measurement results are shown in FIGS. 5-1 and 5-2.
-Measurement condition-
Measuring machine: manufactured by Hitachi High-Tech Science Co., Ltd., differential heat / thermogravimetric measuring device (model number: TG / DTA6300)
Temperature increase rate: 10 ° C / min Measurement temperature range: 30-500 ° C
Measurement atmosphere: air 200 mL / min Reference: Al ₂ O ₃
Sample weight: 10.0mg
Sample container: Al

From the above examples and comparative examples, the following was confirmed.
The powders obtained in Examples 1 to 14 all correspond to the plate-like hydrotalcite-type particles of the present invention, and the slipperiness (MIU, MMD) is significantly higher than the commercially available hydrotalcite powder in Reference Example 1. it was high. In particular, the powder obtained in Example 11 showed a slip property substantially equal to or higher than that of plate-like barium sulfate · H (manufactured by Sakai Chemical Industry Co., Ltd., MIU = 0.64, MMD = 0.0103). As can be seen from, for example, the electron micrographs of the powder obtained in Example 11 (FIGS. 2-1 to 2-4), the obtained powder is thin and has a rough surface. It can be presumed to be caused by the fact that the particles are smooth. On the other hand, the powders obtained in Comparative Examples 1 to 18 are all the plates of the present invention in that at least one of the structural formula, average plate surface diameter, aspect ratio, and pigment pH is outside the range defined in the present invention. In contrast to the powders obtained in Comparative Examples 1-18, the powders obtained in Examples 1-14 are different from the powdered hydrotalcite-type particles. The coating feel was very good (see Tables 3 and 4).

Further, from FIGS. 3-1 to 3-3 and FIG. 4, it was found that the plate-like hydrotalcite-type particles of the present invention are excellent in the adsorption ability of ammonia gas and phosphorus compound. For example, when the powder obtained in Example 11 is used, the ammonia concentration does not change after 1 hour and 22 hours (see FIG. 4), and it can be seen that the adsorption equilibrium is reached in 1 hour. On the other hand, the powder obtained in Comparative Example 18 was Zn—Al type granular hydrotalcite, and its specific surface area (SSA) was almost the same as that of the powder obtained in Example 11, but Comparative Example 18 Compared with the case where the powder obtained in the above is used, the ammonia gas adsorption ability is remarkably high when the powder obtained in Example 11 is used (see FIG. 4). Therefore, it was found that the plate-like hydrotalcite-type particles (Zn—Al type) of the present invention synthesized in a humid atmosphere have a particularly high ammonia gas adsorption ability. Moreover, about the powder obtained in Example 11, the change of the color of the powder before and behind ammonia gas adsorption did not change visually. Further, the powder obtained by adsorbing ammonia gas to the powder obtained in Example 11 for 22 hours was filtered, washed and dried, and the same ammonia gas adsorption test was performed again. Therefore, it was found that reuse after adsorption is also possible.

Therefore, the plate-like hydrotalcite-type particles of the present invention have excellent slipperiness, are sufficiently reduced in irritation to the skin, and have a good application feel to the skin when included in cosmetics. It was confirmed that the adsorbing ability of ammonia gas and phosphorus compound was remarkably excellent.

Claims (5)

1. Following formula (1):
   (Zn) _1-x (Al) _x (OH) ₂ (A ⁿ⁻ ) _{x / n} · mH ₂ O (1)
   (In the formula, A ⁿ⁻ represents an n-valent interlayer anion. X and n are numbers satisfying the conditions of 0.2 ≦ x ≦ 0.4 and 1 ≦ n ≦ 4, respectively. m is a number of 0 or more.), the average plate surface diameter is 150 to 800 nm, the aspect ratio (average plate surface diameter / average thickness) is 4.0 to 20.0, JIS K5101-17-1 (2004) A plate-like hydrotalcite-type particle having a pH value of 6.0 to 8.5 according to a pigment test method.
2. The plate-like hydrotalcite-type particles according to claim 1, wherein the pore volume by BJH method is 0.01 to 1.0 cm ³ / g.
3. The plate-like hydrotalcite-type particles according to claim 1 or 2, wherein a part or all of the surface is coated with a silicon compound.
4. In the formula (1), x and n are each, 0.30 ≦ x ≦ 0.35,1 ≦ n ≦ 3 integers, a satisfying number ^{of, A n-carbonate} ion _(CO ^{3 2 -} plate-like hydrotalcite-type particles according to any one of claims 1 to 3, characterized in that) it is.
5. A cosmetic comprising the plate-like hydrotalcite-type particles according to any one of claims 1 to 4.
   
   
   

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