JP6743821B2 - Plate-shaped hydrotalcite-type particles and their use - Google Patents

Description

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 purposes such as catalysts, pharmaceuticals, and additives for resins. Even in cosmetic applications, particulate hydrotalcite (referred to as hydrotalcite-type particles) is used in the hope of imparting functions such as adsorption of excess sebum and preventing makeup breakdown and shine.

Most of conventional hydrotalcite-type particles are Mg-Al-based hydrotalcite-type particles containing magnesium and aluminum as constituent elements (for example, refer to Patent Document 1). However, in addition to magnesium and aluminum, Mg-Zn-Al-based hydrotalcite-type particles having zinc as a constituent element (see, for example, Patent Document 2) and Zn-Al-based hydrotalcite particles having zinc and aluminum as constituent elements. Talcite-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 JP, 11-240886, A JP, 11-255973, A

As described above, most of the conventional hydrotalcite-type particles are Mg-Al-based hydrotalcite-type particles, but show basicity due to the constituent element magnesium. In applications such as cosmetics, its basicity irritates the skin and adversely affects the skin. Therefore, when using Mg-Al-based hydrotalcite-type particles, the addition amount is limited or other materials are used. The present situation is to reduce the basicity by combining the above. As a means for reducing the basicity of Mg-Al-based hydrotalcite-type particles, it is considered that zinc (Zn), which is an amphoteric metal, is replaced with a part or all of magnesium. In the Al-based hydrotalcite-type particles, zinc is only partially substituting the magnesium site, and the basicity is not sufficiently reduced.

By the way, in cosmetic applications, it is desired that the shape of the particles is plate-like rather than granular. This is because, as compared with the granular particles, the slipperiness is good, and the coverage and the orientation are also excellent. However, the conventional Zn-Al-based hydrotalcite-type particles are granular particles having an aspect ratio of 1 to 2, and there have been no reports of tabular particles until now. This is because the Zn-Al-based hydrotalcite-type particles have a lower ability to retain anions between layers than the Mg-Al-based hydrotalcite-type particles, and thus the conventional Mg-Al-based or Mg-Zn-based particles are used. When the Zn-Al-based plate-like hydrotalcite-type particles are produced by directly converting the method for synthesizing the -Al-based plate-like hydrotalcite-type particles, a part of the raw water-soluble zinc compound (for example, zinc sulfate) is produced. It is considered that the factor becomes zinc hydroxide during the generation of the precursor, and finally becomes zinc oxide, which cannot maintain the layered structure of hydrotalcite. As a method of producing Zn-Al-based hydrotalcite-type particles, a method of removing particles of zinc hydroxide by filtering a precursor slurry and then growing the particles by hydrothermal reaction or the like (Patent Document 6 etc.) However, plate-like particles cannot be obtained even by this method.

The present invention has been made in view of the above circumstances, and an object thereof is to provide plate-like hydrotalcite-type particles that are excellent in slipperiness and have sufficiently reduced skin irritation. Moreover, it aims at providing the cosmetics containing such plate-like hydrotalcite type particles.

The present inventor, while earnestly studying hydrotalcite-type particles, succeeded in producing Zn-Al-based hydrotalcite-type particles having zinc and aluminum as constituent elements and having a plate-like shape. This plate-like hydrotalcite-type particle has a large average plate surface diameter and also has an appropriate thickness, and also has a pH value according to a predetermined test method within an appropriate range, so that the proportion of particles having a plate-like shape is high. The slipperiness and the application feel on the skin when included in cosmetics are good, and the irritation to the skin is sufficiently reduced. In addition, since they are also excellent in the adsorption performance of ammonia gas and phosphorus compounds, they have been found to be useful in various applications, and have come to the conclusion that the above problems can be solved, and have completed the present invention.

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. Plate-shaped hydrotalcite-type particles having a pH value of 6.0 to 8.5 according to the pigment test method of (2004).

The plate-like hydrotalcite-type particles preferably have a pore volume of 0.01 to 1.0 cm ³ /g as measured by the BJH method. As a result, when the particle powder is touched, the feeling of dryness, uniform spreadability and smoothness are further improved, and, for example, when a cosmetic containing hydrotalcite particles is applied to the skin. The particles are further suppressed from being crushed, and as a result, the sustainability of smoothness is further improved.

It is preferable that a part or all of the surface of the plate-like hydrotalcite-type particles is coated with a silicon compound. This suppresses excessive elution of zinc ions, reduces irritation to the skin, and develops an appropriate astringent effect, and improves compatibility and dispersibility with resins and solvents, as well as water repellency. Since it is improved, it is useful not only for cosmetics but also for various applications such as additives to resins.

In the above formula (1), x and n are numbers satisfying the condition of 0.30≦x≦0.35 and an integer of 1≦n≦3, respectively, and A ⁿ⁻ is a carbonate ion (CO ₃ ^{2 -} ) is preferable. As a result, the crystal shape becomes more stable, so that it becomes possible to provide stable and excellent slipperiness and a feel to the skin when included in a cosmetic.

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

3 is an X-ray diffraction pattern of the plate-like hydrotalcite-type particles obtained in Example 11. 3 is an electron micrograph of the plate-like hydrotalcite-type particles obtained in Example 11 taken so that the thickness can be measured (magnification: 50,000 times). 3 is an electron micrograph of the plate-like hydrotalcite-type particles obtained in Example 11 taken so that the thickness can be measured (magnification: 20,000 times). 3 is an electron micrograph of the plate-like hydrotalcite-type particles obtained in Example 11 so that the plate surface diameter can be measured (magnification: 50,000 times). 3 is an electron micrograph of the plate-like hydrotalcite-type particles obtained in Example 11 so that the plate surface diameter can be measured (magnification: 20,000 times). It is a graph which contrasted the time-dependent change of the phosphate ion concentration at the time of making potassium hydrogen phosphate adsorb using the hydrotalcite type particle obtained by Example 11 and the reference example 1, respectively (initial value of phosphate ion concentration. : 50 ppm). It is a graph which contrasted the time-dependent change of the phosphate ion concentration at the time of making potassium hydrogen phosphate adsorb using the hydrotalcite type particle obtained by Example 11 and the reference example 1, respectively (initial value of phosphate ion concentration. : 25 ppm). It is a graph which contrasted the time-dependent change of the phosphate ion concentration at the time of making potassium hydrogen phosphate adsorb using the hydrotalcite type particle obtained by Example 11 and the reference example 1, respectively (initial value of phosphate ion concentration. : 5 ppm). 5 is a graph comparing changes in ammonia concentration over time when ammonia gas is adsorbed using the hydrotalcite-type particles obtained in Example 11, Comparative Example 18 and Reference Example 1, respectively. 5 is a graph showing the results of differential thermal measurement of the hydrotalcite-type particles obtained in Example 11 and Reference Example 1. It is a graph which shows the result of having performed the thermogravimetric measurement about the hydrotalcite type particle obtained in Example 11 and Reference Example 1.

Hereinafter, preferred embodiments of the present invention will be specifically described, but the present invention is not limited to the following description and can be appropriately modified and applied without departing from the scope of the present invention.

[Plate-shaped 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 plate-like particle represented by 0 or more.).

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 (from the viewpoint of reactivity and reduction of environmental load). At least one selected from the group consisting of SO ₄ ²⁻ ) is preferable. Of these, carbonate ion is preferable.

x is a number that satisfies 0.2≦x≦0.4, but within this range, the crystal structure is stable. 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 2/1. From this viewpoint, x is preferably 0.25 or more, more preferably 0.3 or more, and preferably 0.35 or less. It is particularly preferably 1/3 (=about 0.33).

n is a number that satisfies 1≦n≦4, and may be appropriately adjusted depending on the valence of the interlayer anion. It is preferably an integer of 1 to 3, and 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 it due to the presence of attached water. Theoretically, it is preferably 0 or more and less than 5, for example.

In the present invention, in particular, in the above formula (1), x and n are numbers satisfying the conditions of 0.30≦x≦0.35 and 1≦n≦3, respectively, and A ⁿ⁻ is carbonic acid. It is preferably an ion (CO ₃ ²⁻ ). As a result, the crystal shape becomes more stable, so that it becomes possible to stably provide excellent slipperiness and a good application feeling to the skin when included in a cosmetic.

Most preferably, the plate-like hydrotalcite-type particles have 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 represented by. With this structure, the crystal structure is extremely stable, and the effects of the present invention can be more sufficiently exhibited. This structure can be confirmed from JCPDS card 00-048-1023.

The average plate surface diameter of the plate-like hydrotalcite-type particles is 150 to 800 nm. If the average plate surface diameter is within this range, the fluidity of the powder containing the particles will be stable, making it easy to handle during weighing and packaging, and when applied to cosmetics, the application feel to the skin and slipperiness Will also be excellent. The thickness is preferably 180 nm or more, more preferably 190 nm or more, further preferably 300 nm or more, and preferably 500 nm or less, more preferably 470 nm or less.

The aspect ratio (average plate surface diameter/average thickness) of the plate-like hydrotalcite-type particles is 4.0 to 20.0. When the aspect ratio is within this range, the fluidity of the powder containing particles is stable, which makes it easy to handle during weighing and packaging, and also has a smooth feel and slipperiness when applied to the skin when included in cosmetics. It will be excellent. It is preferably 4.5 to 15.0, and more preferably 5.0 to 10.0. Above all, the average value (that is, the average value of the aspect ratio) when the operation of 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. It is more preferably 4.5 to 15.0, 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 scanning electron micrographs. Specifically, it is determined according to the method described in Examples below.

Here, the plate-like hydrotalcite-type particles of the present invention have an important feature that they are plate-like and have a constant 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 feel of application to the skin and the slipperiness when included in a cosmetic, the aspect ratio measured when the aspect ratio is measured 10 times is less than 4.0 or 20. The number of times exceeding 0 is preferably 3 times or less. In addition, it is preferable that the coefficient of variation of the standard deviation calculated when measuring the average plate surface diameter and the average thickness is 0.5 or less. It is more preferably 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, irritation to the skin is sufficiently reduced, which makes it particularly useful for applications such as cosmetics that come into direct contact with 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 according to JIS K5101-17-1 (2004). Specifically, it is determined according to the method described in Examples below.

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 within this range, it has more sufficient strength, and the slipperiness and the application feeling to the skin when included in a cosmetic material are further improved. More preferably 5 to 40 m ² / g, more preferably from 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 the specific surface area obtained by the BET method, which is one of the methods for measuring the specific surface area. Specific surface area refers to the surface area per unit mass of an 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 adsorbed amount. Specifically, the specific surface area is determined by obtaining the monomolecular adsorption amount VM by the BET formula from the relationship between the pressure P and the adsorption amount V. The detailed method for measuring the specific surface area in the present specification will be described in Examples below.

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 particle size, and the fluidity of the powder containing particles is stable. Therefore, it becomes easy to handle at the time of weighing and packaging, and when applied to cosmetics, the feeling of application to the skin and the slipperiness are excellent. When the value of D ₉₀ /D ₁₀ is large, the feel of application to the skin when included in a cosmetic composition tends to be improved, so the value of D ₉₀ /D ₁₀ is more preferably 10 or more, and further preferably 30 or more. A larger D ₉₀ /D ₁₀ means a broader particle size distribution, and a smaller value means a sharper particle size distribution.
In the present specification, D ₁₀ means 10% cumulative particle diameter on a volume basis, and D ₉₀ means 90% cumulative particle diameter on a volume basis. D ₁₀ and D ₉₀ are the values obtained by measuring the particle size distribution. Specifically, it is determined according to the method described in Examples below.

The median diameter (D ₅₀ ) of secondary particles of the plate-like hydrotalcite-type particles is preferably 1 to 200 μm. When the median diameter (D ₅₀ ) is within this range, the fluidity of the powder containing particles is stable, which makes it easy to handle during weighing and packaging, and has a feeling of application to the skin when included in cosmetics and It also has excellent slipperiness.
In the present specification, the median diameter (D ₅₀ ) means a 50% cumulative particle diameter on a volume basis, and when a powder is divided into two from a certain particle diameter, the diameter at which the larger side and the smaller side are equal. Say. Specifically, it is determined according to the method described in Examples below.

The plate-like hydrotalcite-type particles also have a part or all of their surfaces coated with a surface coating agent, as long as they do not impair the good application feel to the skin when they are included in a cosmetic composition. Good. As the surface coating agent, both an inorganic compound and an organic compound can be preferably used. The inorganic compound is not particularly limited, but examples thereof include oxides, hydroxides, sulfates, carbonates and the like of silicon, calcium, barium, strontium, aluminum, zirconium, cerium, zinc and the like. The organic compound is not particularly limited, and examples thereof include silicone oil, fatty acid and metal salt thereof, alkylsilane, alkoxysilane, silane coupling agent, titanium coupling agent, aluminum coupling agent, amino acid, nylon, carbomer and metal salt thereof. , Polyacrylic acid, trimethylpropanol, triethylamine, higher alcohols and the like.

Among the above surface coating agents, a compound containing a silicon atom (also referred to as a silicon compound) is preferable. That is, the plate-like hydrotalcite-type particles preferably have a part or all of the surface coated with a silicon compound. This suppresses excessive elution of zinc ions, reduces irritation to the skin, and develops an appropriate astringent effect, and improves compatibility and dispersibility with resins and solvents, as well as water repellency. Since it is improved, it is useful not only for cosmetics but also for various applications 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 in which sodium silicate and an acid are added to a slurry containing plate-shaped hydrotalcite-type particles to neutralize 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 is preferably 0.001 to 30% by mass relative to 100% by mass of the total amount of plate-like hydrotalcite-type particles. More preferably, it is 5 to 25 mass %.

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

The plate-like hydrotalcite-type particles preferably have a pore volume of 0.01 to 1.0 cm ³ /g as measured by the BJH method. When the pore volume is 0.01 cm ³ /g or more, the porosity of the particles themselves is improved, so the oil absorption in the pores inside the particles is sufficient, and the particles themselves have an appropriate weight. For this reason, when the particle powder is touched, the feeling of dryness, uniform spread and spread, and the sustainability of smoothness are further improved. On the other hand, when it is 1.0 cm ³ /g or less, the porosity of the particles themselves becomes appropriate, so that the particle strength becomes sufficient, and when the cosmetic containing hydrotalcite particles is applied onto the skin, the particles become particles. Is sufficiently suppressed, and as a result, the smoothness persistence is further improved. More preferably, it is 0.02-0.5 cm< ³ >/g.
In the present specification, the pore volume is obtained by using the BJH (Barrett-Joyner-Halenda) method. Specifically, it is determined according to the method described in Examples below.

The plate-like hydrotalcite-type particles have excellent adsorption performance for ammonia gas and phosphorus compounds. 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 waste 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-value width of a peak derived from the (003) plane of 0.4 or more is obtained. It is preferable to employ a manufacturing method including the step (I) and the step (II) of holding the precursor 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 special equipment or 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 in which the half width of the peak derived from the (003) plane is 0.4 or more. In this step (I), crystallization of hydrotalcite is suppressed to prepare a precursor in a low crystalline state, and this precursor is subjected to step (II), whereby in step (II), crystal growth into plate-like particles proceeds. Accordingly, the plate-like hydrotalcite-type particles of the present invention can be obtained easily and easily. 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. Although these zinc compounds and aluminum compounds are not particularly limited, it is preferable to use a water-soluble salt or a water-soluble salt containing an acid from the viewpoint of facilitating the production. 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 is 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 easily.

The amount of the above raw material used may be adjusted so that the resulting plate-like hydrotalcite-type particles satisfy the above formula (1). For example, it is preferable that the zinc compound is 1.5 to 4 mol in terms of zinc, relative to 1 mol of the aluminum compound in terms of aluminum. This stabilizes the crystal structure of the plate-like hydrotalcite-type particles obtained. From the viewpoint of further improving the stability, it is more preferable to adjust the zinc compound to be 1.5 to 3 mol in terms of zinc, relative to 1 mol of the aluminum compound in terms of aluminum, and more preferably 2 mol. is there.

In the step (I), it is preferable to neutralize the raw material with an alkaline component. By carrying out this neutralization, the precursor can be suitably obtained. In this neutralization, it is preferable to mix the raw material and the alkaline component so that the pH of the mixed solution of the raw material and the alkaline component becomes 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 carried out so that the pH of the mixed solution of the above raw material and the alkaline component becomes 7.5 or more.

The alkali component is not particularly limited, and examples thereof include alkali metal salts and the like, and one kind or two or more kinds can be used. The alkali metal salt is, for example, a salt of an alkali metal such as lithium, sodium and potassium, and examples of the salt include hydroxide, carbonate, hydrogen carbonate, silicate, aluminate, organic amine salt and the like. .. Among them, sodium hydroxide, sodium carbonate, sodium hydrogen carbonate and the like are preferable.

The above-mentioned solvent is not particularly limited, and examples thereof include water, an organic solvent and a mixture thereof, and one kind or two or more kinds can be used. Examples of the organic solvent include alcohol, acetone, dimethylsulfoxide, dimethylformamide, tetrahydrofuran, dioxane and the like, and examples of the alcohol include monohydric water-soluble alcohols such as methanol, ethanol and propanol; ethylene glycol, glycerin and the like 2. A water-soluble alcohol having a valency or more; or the like. The solvent is preferably water, more preferably ion-exchanged water.

Here, when a carbonate is not used as a raw material, or when the particles produced by using a carbonate do not satisfy the above formula (1), carbon dioxide may be separately used. Carbon dioxide may be used in any operation during the step (I).

In the step (I), when the 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, washed with water and then dried. When it is filtered, washed with water and then dried, it is also preferable to once make it into a slurry state and then dry it by spray drying.

It is preferable to carry out pulverization after the drying. That is, the step (I) preferably includes neutralization for neutralizing the raw material in the presence of a solvent, drying of the slurry obtained by the neutralization, and pulverization of the dried product. The pulverizing method and pulverizing conditions are not particularly limited, and for example, a ball mill, a liquor machine, a force mill, a hammer mill, a jet mill or the like may be used.

The precursor obtained in the above step (I) may be in a wet cake form (for example, in a state where the measured solid content is 15% by mass or more after drying at 105° C. for 18 hours), or a powder form. It may be present, but among them, powdery one is preferable. When the powdery precursor is subjected to the step (II), the crystal growth into the plate-like particles is further advanced in the step (II) and the excessive aggregation of the primary particles can be suppressed, which is preferable.

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

In the above precursor, the half width of the peak derived from the (003) plane is 0.4 or more. When the precursor in a highly crystalline state having a half-value width of less than 0.4 does not sufficiently plate-form even when it is subjected to the step (II), the average plate surface diameter and the aspect ratio are It is not possible to obtain plate-like hydrotalcite-type particles within the scope of the present invention. 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 further preferably 0.7 or more. The upper limit is preferably 3 or less. It is more preferably 2 or less, still more preferably 1.2 or less.

It is also preferable that the above-mentioned precursor has a half-value width of a peak derived from the (006) plane of 0.4 or more. It is more preferably 0.5 or more, still more preferably 0.6 or more, and particularly preferably 0.7 or more. The upper limit is preferably 3 or less. It is more preferably 2 or less, still more preferably 1 or less.
In the present specification, the full width at half maximum can be determined by an X-ray diffraction method. Specifically, it is determined by the method described in Examples below.

Furthermore, the precursor preferably has a specific surface area of more than 20 m ² /g and 300 m ² /g or less. By subjecting such a precursor to the step (II), the strength and slipperiness of the resulting plate-like hydrotalcite-type particles and the feel of application to the skin when included in a cosmetic composition are improved. It is more preferably 25 m ² /g or more, still more preferably 30 m ² /g or more. The upper limit of the specific surface area is more preferably 250 m ² /g or less.

<Step (II)>
The step (II) is a step (also referred to as “wet atmosphere step”) of holding the precursor obtained in the above step (I) under an atmosphere of a temperature of 75 to 150° C. and a relative humidity of 75 to 100% RH. is there. In the above-mentioned production method, unlike the reaction under the hydrothermal or atmospheric pressure as in the conventional method, the plate-like hydrotalcite is produced by a simple means by undergoing a step of holding the precursor in a high temperature and high humidity atmosphere. Since shaped particles can be obtained, a special device such as a pressure vessel can be eliminated. 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 further preferably 80°C or higher. From the viewpoint of manufacturing cost and equipment specifications, the temperature is preferably 95°C or lower.
In the present specification, the holding temperature of the step (II) means the highest temperature reached in the step.
In addition, since the temperature fluctuation may change the crystal growth of the plate-like particles, the difference between the upper limit and the lower limit of the temperature during holding is preferably 10° C. or less.

The 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, further preferably 78% RH or more, particularly preferably 79% RH or more, and most preferably 80%. %RH or more. From the viewpoint of manufacturing cost and equipment specifications, it is preferably 95% RH or less, and more preferably 90% RH or less.
In the present specification, the relative humidity in the step (II) means the maximum reached humidity in the step.
Since the fluctuation of the relative humidity may change the crystal growth of the plate-like particles, the difference between the upper limit and the lower limit of the humidity during holding is preferably 10% or less.

The holding time under the above conditions may be a time sufficient for the precursor to grow crystals into plate-like particles. For example, it is preferably 1 to 300 hours. If the holding time is within this range, crystallization will proceed more sufficiently and the productivity will be excellent. It is more preferably 3 to 200 hours, further preferably 6 to 180 hours.

<Other process>
In the above-mentioned production method, in addition to the above-mentioned steps (I) and (II), if necessary, one or more of pulverization, classification, washing, hydrothermal treatment, aging, firing, substitution of interlayer ions, surface coating, etc. 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 application feeling to the skin when included in cosmetics, and have sufficiently reduced skin irritation, and ammonia gas and phosphorus. It also has excellent compound adsorption performance. Therefore, it can be used for various purposes such as cosmetics, pharmaceuticals, quasi drugs, adsorbents, catalysts, additives for resins and the like. Among them, a cosmetic material which is particularly useful as a raw material for cosmetics and contains the plate-like hydrotalcite-type particles is one of the present inventions.

The cosmetic contains the plate-shaped hydrotalcite-type particles of the present invention, irritation to the skin is reduced, slipperiness is good, and the application feeling to the skin when included in the cosmetic is excellent, Soft focus effect and sebum adsorption effect can be expected. Therefore, it is particularly suited to the needs of the market today. The cosmetics are not particularly limited, and examples thereof include foundations, makeup bases, sunscreens, eye shadows, blushers, mascaras, lipsticks, antiperspirants, degreasing papers and the like. Among them, the foundation is particularly suitable.

In addition to the plate-like hydrotalcite-type particles of the present invention, the above-mentioned cosmetic may contain one or more other components, if necessary. Other components are not particularly limited, and include, for example, an organic solvent and a dispersant, as well as any aqueous component and oil component generally used in the cosmetic field. Specifically, oils; surfactants; humectants; higher alcohols; sequestering agents; various polymers (natural, semi-synthetic, synthetic or inorganic, water-soluble or oil-soluble polymers); UV screening agents; Ingredients; Various extracts; Inorganic and organic pigments; Various powders of inorganic and organic clay minerals; Inorganic and organic pigments treated with metal soap or silicone; Coloring agents such as organic dyes; Preservatives; Antioxidants Dyes, thickeners, pH adjusters, fragrances, cooling agents, astringents, bactericides, skin activating agents, and the like. The contents of these components are not particularly limited as long as the effects of the present invention are not impaired.

The oil content is not particularly limited, and examples thereof include 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, teaseed oil, kaya oil, rice bran oil, cinnamon oil, Japanese chili oil, jojoba oil, germ oil, triglycerin, glyceryl trioctanoate, tri Hardened oils such as glycerin isopalmitate, cacao butter, coconut oil, horse fat, palm oil, beef tallow, sheep fat, palm kernel oil, lard, beef butter, mokuro kernel oil, hardened beef tallow, hardened palm oil, hardened castor oil , Beef tallow, mokuro, beeswax, candelilla wax, cotton wax, carnauba wax, bayberry wax, ivota wax, whale wax, montan wax, nukarou, lanolin, kapok wax, lanolin acetate, liquid lanolin, sugarcane wax, lanolin fatty acid isopropyl, hexyl laurate, reduced lanolin , Jojoba wax, 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, vaseline, Microcrystalline wax and the like can be mentioned.

Examples of the surfactant include lipophilic nonionic surfactants, hydrophilic nonionic surfactants, and other surfactants. The lipophilic nonionic surfactant is not particularly limited, and examples thereof include sorbitan monooleate, sorbitan monoisostearate, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan sesquioleate, sorbitan trioleate. , Sorbitan fatty acid esters such as penta-2-ethylhexylate diglycerol sorbitan, tetra-2-ethylhexylate diglycerol sorbitan, mono cottonseed oil fatty acid glycerin, monoerucic acid glycerin, sesquioleate glycerin, monostearate glycerin, α,α' -Glycerin oleate pyroglutamate, glycerin polyglycerin fatty acid such as glycerin monostearate malic acid, propylene glycol fatty acid ester such as propylene glycol monostearate, hydrogenated castor oil derivative, glycerin alkyl ether and the like.

The hydrophilic nonionic surfactant is not particularly limited, and examples thereof include POE sorbitan monooleate, POE sorbitan monostearate, POE sorbitan tetraoleate and other POE sorbitan fatty acid esters, POE sorbit monolaurate, POE sorbit monolate. POE glycerin fatty acid esters such as oleate, POE sorbit pentaoleate, POE sorbit monostearate, POE glycerin monostearate, POE glycerin monoisostearate, POE glycerin triisostearate, POE POE fatty acid esters such as monooleate, POE distearate, POE monodioleate, ethylene glycol distearate, POE lauryl ether, POE oleyl ether, POE stearyl ether, POE behenyl ether, POE 2-octyldodecyl ether, POE cholestanol ether, etc. POE alkyl phenyl ethers such as ethers, POE octyl phenyl ether, POE nonyl phenyl ether, and POE dinonyl phenyl ether, Pluronic types such as Bourronic, POE/POP cetyl ether, POE/POP 2-decyl tetradecyl ether, POE/ POP monobutyl ether, POE/POP hydrogenated lanolin, POE/POP alkyl ethers such as POE/POP glycerin ether, tetra-POE/tetra-POP ethylenediamine condensates such as Tetronic, POE castor oil, POE hardened castor oil, POE hardened Castor oil monoisostearate, POE hydrogenated castor oil triisostearate, POE hydrogenated castor oil monopyroglutamic acid monoisostearate diester, POE hydrogenated castor oil POE such as maleic acid, castor oil hydrogenated castor oil derivative, POE such as POE sorbit beeswax Beeswax lanolin derivative, coconut oil fatty acid diethanolamide, lauric acid monoethanolamide, fatty acid isopropanolamide and other alkanolamides, POE propylene glycol fatty acid ester, POE alkylamine, POE fatty acid amide, sucrose fatty acid ester, POE nonylphenylformaldehyde condensate , Alkylethoxydimethylamine oxide, trioleyl phosphoric acid and the like.

Examples of other surfactants include anionic surfactants such as fatty acid soap, higher alkyl sulfate ester salt, POE lauryl sulfate triethanolamine, and alkyl ether sulfate ester salt, alkyl trimethyl ammonium salt, alkyl pyridinium salt, alkyl quaternary salt. 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 humectant is not particularly limited, and examples thereof include xylitol, sorbitol, maltitol, chondroitin sulfate, hyaluronic acid, mucoitin sulfate, caronic acid, atelocollagen, cholesteryl-12-hydroxystearate, sodium lactate, bile salt, dl-pyrrolidone. Examples thereof include carboxylic acid salts, short-chain soluble collagen, diglycerin (EO)PO adducts, Isaioba rose extract, Achillea millefolium extract, Merrilot extract and the like.

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, and cetostearyl alcohol, monostearyl glycerin ether (batyl alcohol), 2-decyltetra. Branched chain alcohols such as decynol, lanolin alcohol, cholesterol, phytosterol, hexyldecanol, isostearyl alcohol, octyldodecanol and the like can be mentioned.

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

The natural water-soluble polymer is not particularly limited, and examples thereof include gum arabic, tragacanth gum, galactan, guar gum, carob gum, karaya gum, carrageenan, pectin, agar, quince seed (quince seed), arge colloid (cassius extract), starch (rice, Corn, potato, wheat), plant-based polymers such as glycyrrhizic acid, microbial-based polymers such as xanthan gum, dextran, succinoglucan, pullulan, and animal-based polymers such as collagen, casein, albumin, and gelatin. ..

The semi-synthetic water-soluble polymer is not particularly limited, for example, carboxymethyl starch, starch-based polymers such as methyl hydroxypropyl starch, methyl cellulose, nitrocellulose, ethyl cellulose, methyl hydroxypropyl cellulose, hydroxyethyl cellulose, sodium cellulose sulfate, Examples thereof include cellulosic polymers such as hydroxypropyl cellulose, sodium carboxymethyl cellulose (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-based polymers such as polyvinyl alcohol, polyvinyl methyl ether, and polyvinylpyrrolidone, polyoxyethylene-based polymers such as polyethylene glycol 20000, 40000, 60000, and polyoxyethylene. Examples thereof include polyoxypropylene copolymer copolymer polymers, acrylic polymers such as sodium polyacrylate, polyethyl acrylate and polyacrylamide, polyethyleneimine, cationic polymers and the like.

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

The ultraviolet shielding agent is not particularly limited, and examples thereof include paraaminobenzoic acid (hereinafter referred to as PABA), PABA monoglycerin ester, N,N-dipropoxy PABA ethyl ester, N,N-diethoxy PABA ethyl ester, N,N-dimethyl. Benzoic acid-based UV screening agents such as PABA ethyl ester and N,N-dimethyl PABA butyl ester; Anthranilic acid-based UV screening agents such as homomenthyl-N-acetylanthranilate; amyl salicylate, menthyl salicylate, homomenthyl salicylate, octyl salicylate , Phenyl salicylate, benzyl salicylate, p-isopropanol phenyl salicylate, and other salicylic acid-based UV screening agents; octyl cinnamate, ethyl-4-isopropyl cinnamate, methyl-2,5-diisopropyl cinnamate, ethyl-2,4-diisopropyl cinnamate Mate, methyl-2,4-diisopropylcinnamate, propyl-p-methoxycinnamate, isopropyl-p-methoxycinnamate, isoamyl-p-methoxycinnamate, 2-ethoxyethyl-p-methoxycinnamate, cyclohexyl-p Cinnamic acid such as -methoxycinnamate, ethyl-α-cyano-β-phenylcinnamate, 2-ethylhexyl-α-cyano-β-phenylcinnamate, glyceryl mono-2-ethylhexanoyl-diparamethoxycinnamate 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2',4,4'-tetra Hydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-4'-methylbenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonate, 4-phenylbenzophenone, 2-ethylhexyl- Benzophenone-based UV screening agents such as 4'-phenyl-benzophenone-2-carboxylate, 2-hydroxy-4-n-octoxybenzophenone, 4-hydroxy-3-carboxybenzophenone; 3-(4'-methylbenzylidene)- d,l-camphor, 3-benzylidene-d,l-camphor, urocanic acid, urocanic acid ethyl ester, 2-phenyl-5-methylbenzoxazole, 2,2'-hydroxy-5-methylphenylbenzo Triazole, 2-(2'-hydroxy-5'-t-octylphenyl)benzotriazole, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, dibenzalazine, dianisoylmethane, 4-methoxy-4' Examples thereof include -t-butyldibenzoylmethane and 5-(3,3-dimethyl-2-norbornylidene)-3-pentan-2-one.

Other drug ingredients are not particularly limited, and examples thereof include vitamin A oil, retinol, retinol palmitate, inosit, pyridoxine hydrochloride, benzyl nicotinate, nicotinamide, nicotinic acid DL-α-tocopherol, magnesium ascorbate phosphate, and 2 -O-α-D-glucopyranosyl-L-ascorbic acid, vitamin D2 (ergocasiferol), dl-α-tocopherol, dl-α-tocopherol acetate, vitamins such as pantothenic acid, biotin; estradiol, ethinyl estradiol, 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 and camphor. Etc., and sulfur, lysozyme chloride, pyridoxine chloride and the like.

The various extracts are not particularly limited and include, for example, Dokudami extract, psyllium extract, meliloth extract, odorophyllum extract, licorice extract, peony extract, saponsou extract, loofah extract, kina extract, snow crab extract, clara extract, kohone extract, fennel. Extract, primrose extract, rose extract, sage extract, lemon extract, shikon extract, aloe extract, ginger 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, corn extract, hamamelis extract, placenta extract, thymus extract, silk extract, licorice extract and the like.

Examples of various powders include bright red pigments such as red iron oxide, yellow iron oxide, black iron oxide, titanium mica, titanium oxide-coated mica titanium, titanium oxide-coated glass flakes, mica, talc, kaolin, sericite, titanium dioxide. Inorganic powders such as silica, polyethylene powder, nylon powder, crosslinked polystyrene, cellulose powder, and organic powders such as silicone powder. Preferably, a part or all of the powder component is subjected to a hydrophobic treatment by a known method with a substance such as silicones, a fluorine compound, a metal soap, an oil agent, and an acylglutamate in order to improve the organoleptic properties and the durability of makeup. It is a thing.

The following examples are given to explain the present invention in detail, but the present invention is not limited to these examples. Unless otherwise specified, “%” means “% by weight (% by mass)”.

Example 1
(1) Mixing 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 ) so that the total amount becomes 350 mL. A metal salt mixed aqueous solution to which ion-exchanged water was added was obtained. Separately, 46.7 mL of a 720 g/L sodium hydroxide aqueous solution was mixed with 26.7 g of sodium carbonate to obtain an alkaline mixed aqueous solution in which ion-exchanged water was added so that the total amount became 350 mL. 50 mL of ion-exchanged water was put into a 1 L round bottom flask, and these aqueous solutions were added under stirring. The pH of the slurry at this time was 9. Then, a slurry was obtained by stirring at 50° C. for 30 minutes.

(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 crushed with a force mill (FM-1 manufactured by Osaka Chemical Co., Ltd.) for 20 seconds to obtain a powder of a hydrotalcite precursor. ..

(5) Wet atmosphere step 1 g of the powder obtained by the above-mentioned "(2) Drying/pulverization" was put 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) and adjust from room temperature to 85° C., relative humidity 85% RH over 15 minutes, hold at 85° C. and relative humidity 85% RH for 3 hours, then stop energizing the heater and cool to room temperature. .. Note that this step was performed in the atmosphere. Thus, powder (1) containing hydrotalcite-type particles was obtained.

Examples 2-6
In Example 1, except that the holding time in "(5) Wet atmosphere step" was changed as shown in Table 1, powder (2) to (() containing hydrotalcite-type particles was prepared in the same manner as in Example 1. 6) were obtained respectively.

Examples 7-11
In Example 1, the reaction time in “(1) Neutralization” (that is, stirring time at 50° C.) was 10 minutes, and the retention time in “(5) Wet atmosphere step” was as shown in Table 1. Powders (7) to (11) containing hydrotalcite-type particles were obtained in the same manner as in Example 1 except that they were changed.

Example 12
The hydrotalcite precursor slurry obtained by “(1) Neutralization” of 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 "(5) Wet atmosphere step", the results are shown in Table 1. Thus, powder (12) containing hydrotalcite-type particles was obtained.

Examples 13 and 14
(3) Aging The slurry obtained by "(1) Neutralization" of Example 7 was weighed into a 1 L round bottom flask so that the solid content in the slurry was 42 g, and the total amount was 600 mL. After adding ion-exchanged water, 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 (FM-1 by Osaka Chemical Co., Ltd.) for 20 seconds to obtain a powder of hydrotalcite precursor. It was 1 g of the obtained powder was subjected to the "(5) wet atmosphere step" of Example 1 (however, the holding time was changed as described in Table 1). Thus, 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) ) Were mixed to obtain a metal salt mixed aqueous solution to which ion-exchanged water was added so that the total amount became 350 mL. Separately, 46.7 mL of a 720 g/L sodium hydroxide aqueous solution was mixed with 26.7 g of sodium carbonate to obtain an alkaline mixed aqueous solution in which ion-exchanged water was added so that the total amount became 350 mL. 50 mL of ion-exchanged water was put into a 1 L round bottom flask, 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 at 50° C. for 30 minutes.

(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 crushed with a force mill (FM-1 manufactured by Osaka Chemical Co., Ltd.) for 20 seconds to obtain a powder of a hydrotalcite precursor. .. 1 g of the obtained powder was subjected to the "(5) wet atmosphere step" of Example 1 (however, the holding time was changed as shown in Table 2). Thus, powder (c1) containing hydrotalcite-type particles was obtained.

Comparative example 2
In Comparative Example 1, the slurry obtained in the same manner as in Comparative Example 1 was filtered 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 to obtain a washing liquid. It was washed with water until the electric conductivity of was less than 100 μS/cm. 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 by Osaka Chemical Co., Ltd.) for 20 seconds to obtain a powder of hydrotalcite precursor. It was 1 g of the obtained powder was subjected to the "(5) wet atmosphere step" of Example 1 (however, the holding time was changed as shown in Table 2). Thus, 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 the "(5) wet atmosphere step" was not performed.

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 step” was not performed. In the same manner as in 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 the holding time in “(5) Wet atmosphere step” 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 and 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 step" were changed as shown in Table 2. (C8) and (c10) to (c12) were obtained.

Comparative Example 9
(4) Hydrothermal The slurry obtained by "(1) Neutralization" of Example 1 was weighed into a 100 mL pressure vessel so that the solid content in the slurry was 5.3 g, and the total amount was 75 mL. After adding ion-exchanged water, the mixture was kept at 180° C. for 2 hours. This 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 crushed with a force mill (FM-1 manufactured by Osaka Chemical Co., Ltd.) for 20 seconds to obtain a powder (c9). Since the majority was zinc oxide, the later-described evaluation was not performed.

Comparative Example 13
(1) Mixing 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 ) so that the total amount becomes 350 mL. A metal salt mixed aqueous solution to which ion-exchanged water was added was obtained. Separately, 46.7 mL of a 720 g/L sodium hydroxide aqueous solution was mixed with 26.7 g of sodium carbonate to obtain an alkaline mixed aqueous solution in which ion-exchanged water was added so that the total amount became 350 mL. 50 mL of ion-exchanged water was put into a 1 L round bottom flask, and these aqueous solutions were added under stirring. The pH of the slurry at this time was 9. Then, a slurry was obtained by stirring at 50° C. for 10 minutes.

(3) Aging The slurry obtained by the above "(1) Neutralization" was weighed into a 1 L round bottom flask so that the solid content in the slurry was 42 g, and ion-exchanged water was added so that the total amount became 600 mL. After adding, 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 (FM-1 manufactured by Osaka Chemical Co., Ltd.) for 20 seconds to obtain a powder containing hydrotalcite-type particles ( c13) was obtained.

Comparative Example 14
A powder (c14) containing hydrotalcite-type particles was obtained in the same manner as in Example 7, except that the "(5) wet atmosphere step" was not performed.

Comparative Example 15
A cake was obtained in the same manner as in Comparative Example 13 except that the aging temperature (50° C.) in “(3) Aging” in Comparative Example 13 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 (FM-1 manufactured by Osaka Chemical Co., Ltd.) 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" of Comparative Example 15 was subjected to "(5) Wet atmosphere step" of Example 1 (however, the holding time is as shown in Table 2). changed). Thus, powders (c16) and (c17) containing hydrotalcite-type particles were obtained.

Comparative Example 18
A cake was obtained in the same manner as in Comparative Example 13 except that the aging temperature (50° C.) in “(3) Aging” in Comparative Example 13 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 (FM-1 manufactured by Osaka Chemical Co., Ltd.) for 20 seconds to obtain a powder containing hydrotalcite-type particles ( c18) was obtained.

Reference example 1
For reference, the hydrotalcite compound is a commercial product _{(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).

The hydrotalcite-type particles (powder) obtained in each of the examples and comparative examples, and a precursor for use in the "(5) wet atmosphere step" (produced when the "(5) wet atmosphere step" is not performed) The physical properties of each product were measured and evaluated according to the following methods.

1. Measurement of full width at half maximum The powder X-ray diffraction pattern (also simply referred to as X-ray diffraction pattern) of each of the obtained powders was measured under the following conditions. For example, the X-ray diffraction pattern of the powder obtained in Example 11 is shown in FIG. Then, the (003) and (006) half widths were measured from the diffraction patterns obtained by the 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 those of JCPDS card 00-048-1023.

-Analysis conditions-
Machine used: Rigaku Corporation RINT-Ultima III
Radiation source: CuKα
Voltage: 50kV
Current: 300mA
Sample rotation speed: 60 rpm
Divergence slit: 1.00mm
Divergence vertical restriction slit: 10 mm
Scattering slit: Open Receiving slit: Open Scanning mode: FT
Counting time: 2.0 seconds Step width: 0.0200°
Operation axis: 2θ/θ
Scanning range: 1.6000 to 70.0000°
Number of times of integration: 1 time The following materials were used to identify the 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 around 2θ=11.6°, and the peak derived from the (006) plane is It is in the vicinity of 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.
Machine used: Mounttech, Macsorb Model HM-1220
Atmosphere: Nitrogen gas (N ₂ )
Degassing conditions of external degassing equipment: 105°C-15 minutes Degassing conditions of main body of specific surface area measuring equipment: 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 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-LEVEL3 by using an ultrasonic homogenizer (US-600, manufactured by Nippon Seiki Seisakusho Co., Ltd.). A sample suspension was prepared by performing a dispersion treatment for a minute. Then, a 0.025 wt% sodium hexametaphosphate aqueous solution was circulated in the sample circulator, the suspension was added dropwise so that the transmittance was 80 to 95%, and the circulation speed was 5 and the stirring speed was 1 at 60%. The measurement was performed after ultrasonic dispersion for 2 seconds. The results are shown in Tables 3 and 4.

4. Elemental analysis The Mg, Zn, Al content in hydrotalcite can be measured by the following method using inductively coupled plasma (ICP) emission spectroscopy.
Specifically, the spectroscope (ICP SPS3100, manufactured by SII) is used as follows, and the 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 to dissolve it, the solution is filled in a 100 mL volumetric flask, and the volume is increased with ion-exchanged water. This was diluted 20 times in Mg content measurement, 50 times in Zn content measurement, and 10 times in Al content measurement, and a test solution was prepared by adding a Sc standard solution so that the Sc concentration was 10 ppm. The Mg, Zn, and Al contents are calculated by calculating the raw data obtained under the following measurement conditions. The results are shown in Tables 3 and 4.

-Measurement conditions-
Using a spectroscope (ICP SPS3100, manufactured by SII), calibration curves were created at wavelengths 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 sample for the calibration curve,
Mg (ppm)=50, 40, 30, 20, 10,
Zn (ppm)=20, 16, 12, 8, 4,
Al (ppm)=50, 40, 30, 20, 10
5 points each are used.
Note that the Sc standard solution was added to each of the calibration curve samples 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

Further, using the Mg, Zn, and Al contents (% by weight) obtained 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, the value corresponding to x in the above formula (1) was determined. The results are shown in Tables 3 and 4.

5. Pore volume Automatic specific surface area/pore distribution measuring device (product name “BEL SORP-miniII”, manufactured by Bell Japan Ltd.) was used. The measurement cell was filled with 0.1 g of a sample, and degassing was performed at 200° C., followed by measurement.
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 means a value obtained by dividing 4 times the total pore volume by the surface area. This assumes that all 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 equations (i) and (ii), the following equation (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 result of pore distribution by the BJH method. The results are shown in Tables 3 and 4.

6. Average plate surface diameter, average thickness, and aspect ratio For each powder, take an electron microscope photograph with 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 drawn randomly 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 calculated by (average plate surface diameter/average thickness). When it is difficult to measure the plate surface diameter and thickness, the platen diameter and the thickness were appropriately increased and photographed. This operation was repeated 10 times by changing the powder to be photographed in each of the Examples and Comparative Examples, and the average value of the obtained aspect ratios was calculated. The results are shown in Tables 3 and 4. Further, when the average plate surface diameter and the average thickness of the powders obtained in the examples are calculated, the standard deviations 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 (standard deviation divided by the average value) was calculated. 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".
A glass container with a stopper was charged with 5 g of a sample in 50 g of distilled water, and while the stopper was removed, the mixture was heated for about 5 minutes to be boiled, and then boiled for another 5 minutes. After boiling, the container was stoppered and allowed to cool to room temperature, the stopper was opened, distilled water corresponding to the weight loss was added, the stopper was capped again, and the mixture was shaken for 1 minute and left 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 amount The oil absorption amount was measured using isopropyl myristate by the following method based on JIS K5101-13-1 (2004).
About 0.5 g of the sample is precisely weighed on the medicine packing paper, and the sample is placed on the ground glass part of 10 cm in the center of the glass plate. Put isopropyl myristate (referred to as “IPM”) in a microburet, add 0.2 mL to the sample dropwise, and knead with a gold spatula. After that, 1 to 2 drops of IPM are added, and the whole is kneaded with a gold spatula at each addition. The end point is when the whole becomes a hard putty-like mass for the first time.
The oil absorption amount was calculated by the following formula. The results are shown in Table 3 (and 4).
Oil absorption (ml/100g) = {V (mL) ÷ sample weight (g)} x 100

9, slipperiness (MIU, MMD)
The slipperiness of each sample was evaluated by the following method.
A double-sided tape was attached to a slide glass, a powder (sample) of about half a spoon was placed on the adhesive surface, the powder was spread with a cosmetic sponge, and a friction element was set on it. 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).
As a comparison object, plate-shaped barium sulfate·H (manufactured by Sakai Chemical Industry Co., Ltd.) and STABACE HT-1NC (manufactured by Sakai Chemical Industry Co., Ltd.), which is a commercially available hydrotalcite compound (Reference Example 1), were used.
The average friction coefficient MIU of the plate-shaped barium sulfate·H is 0.64, the variation value MMD of the average friction coefficient is 0.0103, and the average friction coefficient MIU of STABIACE·HT-1NC is 0.897, 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 slips as the numerical value is smaller, and the variation value MMD of the friction coefficient is an index indicating that the powder is smoother and less rough. The results are shown in Table 3 (and 4).

10, evaluation as cosmetics (sensory evaluation)
(1) First, 20.00% by weight of hydrotalcite obtained in Examples and Comparative Examples, mica (product name: Y-2300X, manufactured by Yamaguchi Mica Co., Ltd.) 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 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: red iron oxide, manufactured by Pinoa) 0.37% by weight, Using a coffee mill, 0.92% by weight of metal soap (product name: JPM-100, manufactured by Sakai Chemical Industry Co., Ltd.) and 9.20% by weight of oil (product name: KF96, manufactured by Shin-Etsu Chemical Co., Ltd.) were used. The mixture was stirred and mixed for 30 minutes.
0.8 g of the obtained powdery mixture was weighed in a mold having a diameter of 20 mm and held at a pressure of 200 kgf/cm ² for 30 seconds 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, manufactured by Pinoa Co., Ltd. 1.38% by weight, iron oxide (red) (product name: red iron oxide, manufactured by Pinoa Co., Ltd.) 0.46% by weight, metal soap (product name: JPM-100, Sakai Chemical Industry Co., Ltd.) 1.15% by weight of oil) and 11.49% by weight of oil (product name: KF96, manufactured by Shin-Etsu Chemical Co., Ltd.) were stirred and mixed for 1 minute 30 seconds using a coffee mill.
0.8 g of the obtained powdery mixture was weighed in a mold having a diameter of 20 mm and held at a pressure of 200 kgf/cm ² for 30 seconds using a pressing machine to prepare a hydrotalcite-free foundation. did.

(3) The foundation obtained in each of the above (1) and (2) was applied to 10 panelists, and the application feeling to the skin when included in cosmetics was evaluated according to the following criteria. did. The test was conducted blindly. The evaluation results are shown in Tables 3 and 4.
(Evaluation criteria for feel of application)
⊚: The use of the hydrotalcite-containing foundation of (1) above gives a better coating feel than the use of (2) non-hydrotalcite-containing foundation.
◯: Both have the same application feeling.
X: The use of the hydrotalcite-free foundation of (2) above gives a better coating feel than the use of the hydrotalcite-containing foundation of (1) above.

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

12. Phosphorus compound adsorption rate in aqueous solution Potassium hydrogen phosphate was used to add 1 g of the sample to 100 g of the solution in which the phosphate ion concentration was adjusted to 50, 25, and 5 ppm, respectively, and the mixture was stirred for a predetermined time and then filtered. The phosphate ion concentration of the prepared solution was measured by an ion chromatograph (manufactured by Dionex, model number: ICS-2000). The phosphate ion concentrations measured over time when the powder obtained in Example 11 was 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 to the blank after the lapse of time a was calculated by the following formula.
Phosphorus compound adsorption rate (%)=100×(Phosphate ion concentration of blank after a time has elapsed-Phosphate ion concentration of evaluation sample (sample) after a time has elapsed)/(Blank phosphoric acid after a time has elapsed) Ion concentration)
In addition, the phosphate ion concentration of the blank after the lapse of time a was agitated for a predetermined time without putting the evaluation sample in 100 g of the solution in which the phosphate ion concentration was adjusted to 50, 25.5 ppm using potassium hydrogen phosphate. , A 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 into a 5 L sampling bag (manufactured by GL Science Co.), and a 5 L sampling bag containing no sample was also prepared as a blank. After injecting 3 L of nitrogen gas containing 100 ppm of ammonia into the sampling bag, the sampling bag was immediately sealed and left standing for 1 hour under the conditions of 20° C. and 65% humidity. After standing still, 100 mL of gas in the sampling bag was sucked in with a suction device, and the concentration of ammonia was measured with a detector tube (No. 3La) manufactured by Gastec. FIG. 4 shows the change over time in the ammonia concentration when the powder obtained in Example 11 was used. For comparison, FIG. 4 also shows changes 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 for the blank was calculated by the following formula.
Ammonia gas adsorption rate (%) = 100 x (blank ammonia concentration-evaluation sample ammonia concentration)/(blank ammonia concentration)
Note that the blank ammonia concentration is the ammonia concentration measured without inserting the evaluation sample, sealing the sampling bag containing only 3 L of nitrogen gas containing 100 ppm of ammonia, and allowing it to stand for 1 hour. The blank ammonia concentration was 100 ppm.

14. Differential thermal/thermogravimetric measurement For the powders of Example 11 and Reference Example 1, differential thermal/thermogravimetric measurement (TG/DTA) was performed. Specifically, differential thermal/thermogravimetric measurement (TG/DTA) was performed under the following conditions. The measurement results are shown in FIGS. 5-1 and 5-2.
-Measurement conditions-
Measuring instrument: Hitachi High-Tech Science Co., Ltd., differential thermal/thermogravimetric measuring device (model number: TG/DTA6300)
Temperature rising rate: 10°C/min Measurement temperature range: 30 to 500°C
Measurement atmosphere: Atmosphere 200 mL/min Reference: Al ₂ O ₃
Sample weight: 10.0mg
Sample container: Al

The following things were confirmed from the above Examples and Comparative Examples.
The powders obtained in Examples 1 to 14 all correspond to the plate-like hydrotalcite-type particles of the present invention, and have a remarkable slipperiness (MIU, MMD) with respect to the commercially available hydrotalcite powder in Reference Example 1. it was high. In particular, the powder obtained in Example 11 showed slipperiness almost equal to or higher than that of plate-shaped barium sulfate·H (manufactured by Sakai Chemical Industry Co., Ltd., MIU=0.64, MMD=0.0103). This is because, for example, as can be seen from the electron micrographs (FIGS. 2-1 to 2-4) of the powder obtained in Example 11, the obtained powder is in the form of a thin plate and has a finely grained surface. It can be inferred that it is due to the smooth particles having no On the other hand, the powders obtained in Comparative Examples 1 to 18 are all the plates of the present invention in that one or more of the structural formula, the average plate surface diameter, the aspect ratio and the pigment pH are out of the ranges specified in the present invention. Unlike the powder-like hydrotalcite-type particles, the powders obtained in Examples 1 to 14 are different from the powders obtained in Comparative Examples 1 to 18 to the skin when included in cosmetics. The application feeling of No. 1 is extremely 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 compounds. For example, when the powder obtained in Example 11 is used, it can be seen that the adsorption equilibrium is reached in 1 hour because the ammonia concentration does not change after 1 hour and 22 hours (see FIG. 4). 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 When the powder obtained in Example 11 is used, the ammonia gas adsorption capacity is remarkably higher than that when the powder obtained in (1) 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 wet atmosphere have a specifically high ammonia gas adsorption capacity. Further, regarding the powder obtained in Example 11, the change in the color of the powder before and after the adsorption of ammonia gas was not visually observed. Further, the powder obtained by adsorbing ammonia gas on the powder obtained in Example 11 for 22 hours was filtered, washed with water, and dried, and the same ammonia gas adsorption test was conducted again. Therefore, it was found that it can be reused after adsorption.

Therefore, the plate-like hydrotalcite-type particles of the present invention are excellent in slipperiness, the irritation to the skin is sufficiently reduced, and the application feeling to the skin when included in a cosmetic is good. It was confirmed that the adsorption capacity for ammonia gas and phosphorus compounds was outstanding.

Claims (5)

Formula (1) below:
(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 500 nm, the aspect ratio (average plate surface diameter/average thickness) is 4.0 to 20.0, JIS K5101-17-. A plate-like hydrotalcite-type particle having a pH value of 6.0 to 8.5 according to the pigment test method of No. 1 (2004). The plate-like hydrotalcite-type particles according to claim 1, wherein the pore volume according to the BJH method is 0.01 to 1.0 cm ³ /g. The plate-like hydrotalcite-type particles according to claim 1 or 2, wherein a part or all of the surface is covered with a silicon compound. In the formula (1), x and n are numbers satisfying the condition of 0.30≦x≦0.35 and an integer of 1≦n≦3, respectively, and A ⁿ⁻ is a carbonate ion (CO ₃ ^{2 −} ) The plate-like hydrotalcite-type particle according to any one of claims 1 to 3, wherein A cosmetic comprising the plate-shaped hydrotalcite-type particles according to any one of claims 1 to 4.