JPH0692630A - Production of barium sulfate, platy barium sulfate obtaine thereby and cosmetic using the same - Google Patents

Abstract

PURPOSE:To enable the obtaining of platy barium sulfate, having a narrow particle size distribution and good in optical characteristics and improve the feeling of use such as extensibility and adhesion of a cosmetic using the platy barium sulfate. CONSTITUTION:This method for producing barium sulfate is to make a barium compound react with a compound of sulfuric acids at respective concentrations of 0.001-0.1mol/l and (1/10) to (5/1) molar ratio in starting reaction in the presence of 0.0002-0.02wt.% sparingly soluble crystallite under conditions of pH1.0-12.0 and 50-100 deg.C reactional temperature. Furthermore, the platy basium sulfate is obtained thereby and the cosmetic uses this platy barium sulfate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing barium sulfate having a particle size and shape suitable as a cosmetic ingredient, a plate-like barium sulfate thus obtained, and a cosmetic using the same.

[0002]

BACKGROUND ART Barium sulfate is industrially widely used as an X-ray contrast agent, a γ-ray absorber, a white pigment, etc. because it is harmless to the human body and has a strong hiding power. However, when used as a cosmetic, especially as a foundation, conventional barium sulfate has drawbacks in that it does not spread well and stick, and lacks a comfortable feeling. In addition, there is a problem in that it lacks transparency and the feeling of bare skin is poor after makeup.

In order to solve these problems, barium sulfate having a large particle size (Japanese Patent Laid-Open No. 58-41718), barium sulfate in plate and needle crystals (Japanese Patent Laid-Open No. 62-62).
Japanese Patent No. 174238) has been proposed. But,
In order to produce these barium sulfates, further heat treatment and mineral acid treatment are required for the purpose of removing particles of barium sulfate having a particle size or shape that does not match the purpose after the synthesis, which complicates the production process. There is a problem. Further, it is difficult to completely remove the skeleton even after such a post-treatment, and the size and shape of the obtained barium sulfate particles are not satisfactory as a cosmetic ingredient.

Bull. Chem. Soc. Japan, Vol. 27, No. 3,
On page 121, the size and shape of the barium sulfate particles are governed by the concentration of the mixed raw materials, and as the concentration decreases, the barium sulfate particles are variously transformed into amorphous, spherical, spindle-shaped, diamond-shaped, etc., and the particle size is 0. It is shown that the change greatly changes to about 0.013 to 2.0 μ.

[0005]

When barium sulfate is used as a cosmetic ingredient such as a foundation, it is preferable that the particles are appropriately coarse particles and have a plate-like structure in order to impart a suitable feeling of use. However, in the above-mentioned conventional technology, it is difficult to produce such particles per se, or although they can be produced, the particle diameters are uniform (that is,
It was difficult to industrially stably supply barium sulfate (having a narrow particle size distribution).

[0006] Therefore, an object of the present invention is to solve the above problems and to provide a production method capable of industrially stably supplying barium sulfate suitable as a cosmetic ingredient. Another object of the present invention is to provide plate-shaped barium sulfate obtained by the production method and cosmetics using the plate-shaped barium sulfate.

[0007]

Therefore, as a result of various studies on the conditions of the reaction between the raw barium compound and the sulfuric acid compound in order to solve the above problems, the present inventors have found that the barium sulfate particle size and shape are controlled. It is necessary to adjust not only the raw material concentration but also the raw material molar ratio, the concentration of the seed crystal, the pH and the reaction temperature. If these are kept within a certain range, barium sulfate having a well-developed plate-like structure can be obtained. Barium sulphate has specific optical properties, has excellent usability such as elongation and stickiness, and has high light diffusivity, transparency, and bare skin feeling, while making it difficult to see spots, freckles, and other color irregularities. They found that they have effects and are excellent as cosmetic ingredients, and completed the present invention.

In the method for producing barium sulfate according to the present invention, the respective concentrations at the start of the reaction are 0.001-0.1 mol /
0.0002-0.02 of a barium compound and a sulfuric acid compound having a molar ratio of 1/10 to 5/1.
PH 1.0-12. In the presence of wt% sparingly soluble microcrystals.
It is characterized in that the reaction is carried out under conditions of 0 and a reaction temperature of 50 to 100 ° C.

The barium compound used in the present invention is not particularly limited as long as it produces Ba ^{2+ in} a solvent such as water, and is selected from barium hydroxide, barium chloride, barium sulfide, barium nitrate and barium acetate. More than one species can be used. Among these, barium hydroxide, barium chloride, barium nitrate or barium acetate is preferable,
Barium hydroxide and barium chloride are more preferred because of the ease of processing and availability of the by-products produced by the reaction.

The sulfuric acid compound used in the present invention is a compound which produces SO ₄ ^2- in a solvent such as water, and examples thereof include sulfuric acid; sulfates such as sodium sulfate, ammonium sulfate, potassium sulfate and lithium sulfate; and sodium hydrogen sulfate. One or more selected from hydrogen sulfates and the like can be used. Among these, sulfuric acid, sodium sulfate, ammonium sulfate and sodium hydrogensulfate are preferable, and sulfuric acid is more preferable in terms of availability and price.

The concentration of these barium compound and sulfuric acid compound at the start of the reaction (that is, the concentration of Ba ²⁺ and SO ₄ ²⁻ ) is in the range of 0.001 to 0.1 mol / l. In addition, it is necessary to adjust the molar ratio (mol number of barium compound / mol number of sulfuric acid compound) to be in the range of 1/10 to 5/1. Adjustment of such concentration and molar ratio is
It is preferable to carry out by preparing a barium compound solution and a sulfuric acid compound solution satisfying these conditions, respectively.

If the molar ratio is out of this range, not only the yield decreases but also the operation of removing unreacted compounds and by-products becomes complicated. If the concentration is less than 0.001 mol / l, the degree of supersaturation is low and the crystal growth is insufficient, and coarse particles cannot be obtained. Further, when it exceeds 0.1 mol / l, the degree of supersaturation is extremely large, so that nucleation occurs instantaneously, and only ultrafine particles of submicron or less can be obtained. become worse. The preferred concentration is 0.005-0.03 mol / l.

These barium compound and sulfuric acid compound are reacted in the presence of hardly soluble microcrystals.

The hardly soluble microcrystals serve as the target seed crystal of barium sulfate and have an average particle size of 0.005.
At least one selected from inorganic compounds having a thickness of 10 μm, such as barium sulfate, barium carbonate, zirconia, alumina, silica and titania can be used. Among these, barium sulfate, zirconia, alumina or titania which are acid-resistant and base-resistant substances are preferable. The term "poorly soluble" as used herein refers to a case where the weight dissolved in 1 liter of ion-exchanged water at room temperature (about 20 ° C) is 50 mg or less.

The amount of hardly soluble crystallites present in the reaction solution is 0.0002 to 0.02% by weight, based on the total weight of the solution. If this amount is less than 0.0002% by weight, the average particle size of the obtained barium sulfate is very large and the particle size distribution is wide, so when blended in cosmetics, the feeling of use such as stretching and sticking deteriorates, and light scattering occurs. The transparency is also low. On the other hand, if it exceeds 0.02% by weight, the obtained barium sulfate particles become too small, and if it is blended in a cosmetic composition, the usability is significantly deteriorated. It is preferable that the hardly soluble microcrystals are allowed to exist in the reaction system by adding to one or both of the two raw material solutions.

The reaction is carried out at a pH of the reaction system of 1.0 to 12.0.
The reaction temperature is 50 to 100 ° C., preferably 60 to 95.
Hold at ℃ set. If the content of the barium sulfate is out of the above range, the crystal structure of the obtained barium sulfate is broken, so that when it is blended in a cosmetic composition, the feeling of use is poor and the light transmittance is lowered. In addition, other reaction conditions, reaction operations, etc. are not particularly limited, and, for example, a barium compound, a sulfuric acid compound and a sparingly soluble microcrystal may be simultaneously charged into one solvent and reacted.

According to the manufacturing method of the present invention, plate-shaped barium sulfate having an aspect ratio of 5 to 100 can be obtained.
When the aspect ratio is less than 5, the texture becomes rough when blended into the foundation and the usability is poor. When the aspect ratio exceeds 100, the production is difficult and stable supply cannot be achieved.

Further, according to the production method of the present invention, the volume cumulative average particle diameter is as coarse as 3.0 to 10.0 μm, and the ratio of the particle diameter to the average particle diameter at 84.13% under the sieve accumulation. Is 1.3 to 1.8, and plate-shaped barium sulfate having a relatively narrow particle size distribution (compared with the prior art) can be obtained. When the volume cumulative average particle diameter is less than 3.0 μm, when this is blended in a foundation, the elongation at the time of application becomes poor and a feeling of bulkiness appears, while the volume cumulative average particle diameter is 1
If it exceeds 0 μm, the feeling of roughness increases and the sticking deteriorates, so that the feeling of use also deteriorates. When the ratio of the particle size and the average particle size in the cumulative under-sieving 84.13% is out of the range of 1.3 to 1.8, when similarly blended in the foundation, elongation and sticking at the time of application become poor, A feeling of bulkiness appears and the optical characteristics are impaired.

Furthermore, according to the manufacturing method of the present invention, when a thin film having a powder concentration of 20% by weight and a thickness of 15 μm is formed, the light scattering transmittance is 55% or more and the total light transmittance is 88. %
The plate-shaped barium sulfate described above can be obtained. When this is compounded in a foundation, a light scattering transmittance of 55% or more has high light diffusivity and a total light transmittance of 88%.
% Or more, the transparency is excellent.

Because of having such characteristics, these plate-shaped barium sulfates can be used as an extender pigment for cosmetics. In this case, the compounding amount of the plate-shaped barium sulfate can be arbitrarily selected according to the properties of the cosmetic, but is 0.1 to 99% by weight, especially 10 to 9% by weight based on the total amount of the cosmetic.
It is preferably 0% by weight.

Cosmetics containing these barium sulfate in the form of plates include makeup cosmetics such as foundation, powder white powder, solid white powder, blusher, eye shadow, lipstick and eyeliner, and basic cosmetics such as cream and emulsion. Is mentioned. Further, these cosmetics can be produced according to a usual method, and in the production thereof, in addition to the plate-shaped barium sulfate, spherical metal oxides or organic powders, and zinc monoalkylphosphate salts, N -A surfactant polyvalent metal salt pigment powder such as lauroyl taurine calcium salt can be blended.

[0022]

The present invention will be described below with reference to examples, but the present invention is not limited to these examples. The volume average particle diameter, aspect ratio, light scattering transmittance and total light transmittance in the following examples and comparative examples were evaluated by the following methods.

Volume cumulative average particle diameter The synthesized barium sulfate slurry was cooled to room temperature, and 5
After filtering with a filter paper of C, washing with ion-exchanged water, and drying at 100 ° C. for 5 hours, barium sulfate powder is obtained. Next, this powder was added to sodium polyacrylate (trade name: Poise 530).
Was redispersed in a 0.1% aqueous solution of and was measured by a particle size distribution measuring device (manufactured by Horiba, Ltd., model: LA-700). Further, from the obtained results, the ratio (σg) between the particle size and the average particle size at 84.13% under the sieve was determined and used as an index of the particle size distribution width. Aspect ratio The diameter and thickness of the plate-shaped surface of 100 particles were measured from a scanning electron micrograph, and calculated from the ratio of the diameter and thickness of the plate-shaped surface. Light scattering transmittance and total light transmittance The synthesized barium sulfate slurry was cooled to room temperature, and 5
After filtering with a filter paper of C, washing with ion-exchanged water, and drying at 100 ° C. for 5 hours, barium sulfate powder is obtained. Next, using a silicone oil (amino-modified silicone oil: Toray Silicone Co., Ltd .: SF8417) as a dispersion medium, 20% by weight of this barium sulfate powder was added and uniformly kneaded, and a thin film of 15 μm was formed on a glass plate by an applicator. Let it form. Further, this was measured by a haze meter (Murakami Color Research Laboratory, model: HR-100) for parallel light transmittance (T
p) and the scattered light transmittance (Td) were measured, and (Tp + Td)
Is the total light transmittance, and [Td / (Tp + Td)] × 100
Was defined as the light scattering transmittance.

Example 1 2.08 g of special grade barium chloride and 0.9 of special grade sulfuric acid
8 g (molar ratio = 1/1) was dissolved in 1000 g of ion-exchanged water to obtain a 0.01 mol / l barium chloride solution and a 0.01 mol / l sulfuric acid solution. 0.1165 g (0.01165% by weight) of barium sulfate powder having a volume cumulative average particle size of 2.0 μm was further added to the barium chloride solution. Then, a 2 l flask was charged with a sulfuric acid solution, and heated to 95 ° C. with stirring with a Teflon paddle at 200 rpm. Next, a barium chloride solution (containing barium sulfate powder) heated to the same temperature was added dropwise thereto for 10 seconds. Then, stirring was continued for 3 minutes to complete the reaction. The pH during the reaction was 2.0. Next, the mixture was cooled to room temperature, filtered with a 5C filter paper, washed with ion-exchanged water, and then dried at 100 ° C. for 5 hours to obtain 2.1 g of barium sulfate powder. The barium sulfate powder thus obtained has a volume cumulative average particle diameter of 5.7 μm.
m, aspect ratio 33, and σg 1.48, the particle size distribution was relatively narrow, and the light scattering transmittance was 62.6% and the total light transmittance was 90.5%. In addition, when this powder was blended into a foundation which was a cosmetic material, the feeling of use was good and the transparency of the cosmetic film was high compared to the conventional blends with extender pigments such as mica and talc.

Example 2 Special reagent barium chloride 4.16 g and special reagent sulfuric acid 1.9
6 g (molar ratio = 1/1) was dissolved in 1000 g of ion-exchanged water to prepare a 0.02 mol / l barium aqueous solution and a 0.02 mol / l sulfuric acid solution. The barium chloride solution and sulfuric acid solution also have a volume cumulative average particle size of 0.8μ.
m barium sulfate powder 0.01165 g (0.0011
65% by weight) each. Then, a 2 liter flask was charged with a sulfuric acid solution (containing barium sulfate powder) and heated to 95 ° C. with stirring with a Teflon paddle at 200 rpm. Next, a barium chloride solution (containing barium sulfate powder) heated to the same temperature was added dropwise thereto for 10 seconds. Then, stirring was continued for 3 minutes to complete the reaction. The pH during the reaction was 1.8. Next, the mixture was cooled to room temperature, filtered through a 5C filter paper, washed with ion-exchanged water, and then dried at 100 ° C. for 5 hours to obtain 4.4 g of barium sulfate powder. The barium sulfate powder thus obtained has a relatively narrow particle size distribution with a volume cumulative average particle size of 7.6 μm, an aspect ratio of 79, and a σg of 1.53, and has a light scattering transmittance of 57.8% and a total light transmittance. The degree is 91.2
%Met. In addition, when this powder was blended into a foundation which was a cosmetic material, the feeling of use was good and the transparency of the cosmetic film was high compared to the conventional blends with extender pigments such as mica and talc.

Example 3 1.872 g of special-grade reagent barium chloride, 0.171 g of special-grade reagent barium hydroxide and 0.98 g of special-grade reagent sulfuric acid (molar ratio = 1/1) were dissolved in 1000 g of ion-exchanged water to obtain 0.01 mol. / L barium solution (mixture of barium chloride solution and barium hydroxide solution) and 0.01mo
A 1 / l sulfuric acid solution was prepared. The barium solution also contains 0.05 barium sulfate powder having a volume cumulative average particle size of 2.0 μm.
83 g (0.00583% by weight) was added. afterwards,
A 2 liter flask was charged with a sulfuric acid solution, and heated to 95 ° C. with stirring using a Teflon paddle at 200 rpm. Next, a barium solution (containing barium sulfate powder) heated to the same temperature was added dropwise thereto for 25 seconds. Then, stirring was continued for 3 minutes to complete the reaction. The pH during the reaction was 2.0 (the initial stage of the reaction) to 2.1 (the final stage of the reaction). Next, the mixture was cooled to room temperature, filtered with a 5C filter paper, washed with ion-exchanged water, and then dried at 100 ° C. for 5 hours to obtain 2.1 g of barium sulfate powder. The barium sulfate powder thus obtained had a volume cumulative average particle diameter of 6.3 μm, an aspect ratio of 47, and a σg of 1.65.
With a relatively narrow particle size distribution, the light scattering transmittance is 61.0%,
The total light transmittance was 90.9%. In addition, when this powder was blended into a foundation that was a cosmetic, compared with the conventional blends of extenders such as mica and talc,
The feeling of use was good and the transparency of the cosmetic film was high.

Example 4 1.872 g of special grade reagent barium chloride, 0.171 g of special grade reagent barium hydroxide and 1.96 g of special grade reagent sulfuric acid (molar ratio = 1/2) were dissolved in 1000 g of ion-exchanged water to obtain 0.01 mol. / L barium solution (mixture of barium hydroxide solution and barium chloride solution), 0.02mo
A 1 / l sulfuric acid solution was prepared. The sulfuric acid solution further contained 0.002 g of zirconia sol having a volume cumulative average particle diameter of 0.1 μm.
(0.0002% by weight) was added. Then, a 2 liter flask was charged with a sulfuric acid solution (containing zirconia sol) and stirred with a Teflon paddle at 200 rpm while stirring.
Heated to ° C. Then, a barium solution heated to the same temperature was added dropwise thereto for 25 seconds. Then, stirring was continued for 3 minutes to complete the reaction. PH during the reaction is 1.8
It was from (the initial stage of the reaction) to 1.9 (the final stage of the reaction). next,
The mixture was cooled to room temperature, filtered through a 5C filter paper, washed with ion-exchanged water, and then dried at 100 ° C. for 5 hours to obtain 2.1 g of barium sulfate powder. The barium sulfate powder thus obtained has a volume cumulative average particle diameter of 5.0 μm.
m, aspect ratio was 29, and σg was 1.41 with a relatively narrow particle size distribution, and light scattering transmittance was 65.1% and total light transmittance was 89.9%. In addition, when this powder was blended into a foundation which was a cosmetic material, the feeling of use was good and the transparency of the cosmetic film was high compared to the conventional blends with extender pigments such as mica and talc.

Example 5 3.42 g of special grade reagent barium hydroxide and special grade reagent sulfuric acid 1.
96 g (molar ratio = 1/1) was dissolved in 2000 g of ion-exchanged water to obtain a 0.01 mol / l barium hydroxide solution and a 0.01 mol / l sulfuric acid solution. To the sulfuric acid solution was further added 0.01 g (0.0005% by weight) of titania powder having a volume cumulative average particle diameter of 0.01 μm. Then, add sulfuric acid solution (containing titania powder) to a 5 liter flask.
And was heated to 95 ° C. with stirring with a Teflon paddle at 200 rpm. Then, a barium hydroxide solution heated to the same temperature was added dropwise thereto for 3 minutes. Then, stirring was continued for 3 minutes to complete the reaction. The pH during the reaction was 2.0 (initial stage of reaction) to 7.0 (late stage of reaction). Next, it is cooled to room temperature, filtered with 5C filter paper, washed with ion-exchanged water, and then 100 ° C.
After drying for 5 hours, 4.4 g of barium sulfate powder was obtained.
The barium sulfate powder thus obtained had a volume cumulative average particle diameter of 3.8 μm, an aspect ratio of 8, and a σg of 1.57.
With a relatively narrow particle size distribution, the light scattering transmittance is 69.1%,
The total light transmittance was 88.5%. In addition, when this powder was blended into a foundation that was a cosmetic, compared with the conventional blends of extenders such as mica and talc,
The feeling of use was good and the transparency of the cosmetic film was high.

Example 6 1.872 g of special grade reagent barium chloride, 0.171 g of special grade reagent barium hydroxide and 0.98 g of special grade reagent sulfuric acid (molar ratio = 1/1) were dissolved in 1000 g of ion-exchanged water to obtain 0.01 mol. / L barium solution (mixture of barium chloride solution and barium hydroxide solution) and 0.01 mol
/ L sulfuric acid solution. 0.03 g of barium sulfate powder having a volume cumulative average particle size of 6.0 μm in any of the solutions
(0.006% by weight in total) were added each. afterwards,
A 2 liter flask was charged with a sulfuric acid solution (containing barium sulfate powder) and heated to 95 ° C. with stirring with a Teflon paddle at 200 rpm. Next, a barium solution (containing barium sulfate powder) heated to the same temperature was added dropwise thereto for 5 seconds. Then, stirring was continued for 3 minutes to complete the reaction. The pH during the reaction is from 2.0 (the initial stage of the reaction) to 2.
It was 1 (end of reaction). Next, cool to room temperature, and 5C
After being filtered with a filter paper of No. 1, washed with water using ion-exchanged water, and then dried at 100 ° C. for 5 hours, 2.1 g of barium sulfate powder was obtained. The barium sulfate powder thus obtained has a relatively narrow particle size distribution with a volume cumulative average particle size of 8.9 μm, an aspect ratio of 85, and a σg of 1.55, and has a light scattering transmittance of 56.0% and a total light transmittance. The degree was 91.5%. In addition, when this powder was blended into a foundation which was a cosmetic material, the feeling of use was good and the transparency of the cosmetic film was high compared to the conventional blends with extender pigments such as mica and talc.

Examples 7 to 10 Reactions were carried out according to Examples 1 to 6 under the conditions shown in Tables 1 and 2. The results are summarized in Table 3. In addition, when the barium sulfate powder obtained in each of the examples was blended into a foundation that was a cosmetic material, it had a better feeling of use and a transparent cosmetic film than those that were blended with conventional extenders such as mica and talc. It was also very popular.

[0031]

[Table 1]

[0032]

[Table 2]

[0033]

[Table 3]

Comparative Example 1 2.08 g of special-grade reagent barium chloride and 0.9 of special-grade reagent sulfuric acid
8 g (molar ratio = 1/1) was dissolved in 1000 g of ion-exchanged water to obtain a 0.01 mol / l barium solution and a 0.01 mol / l sulfuric acid solution. Then, a 2 l flask was charged with a sulfuric acid solution, and heated to 95 ° C. with stirring with a Teflon paddle at 200 rpm. Then, a barium chloride solution heated to the same temperature was added dropwise thereto for 10 seconds. Then, stirring was continued for 3 minutes to complete the reaction. The pH during the reaction was 2.0. next,
The mixture was cooled to room temperature, filtered through a 5C filter paper, washed with ion-exchanged water, and then dried at 100 ° C. for 5 hours to obtain 2.1 g of barium sulfate powder. The barium sulfate powder thus obtained has a volume cumulative average particle size of 11.2.
It is a coarse crystal having a relatively wide particle size distribution with a micrometer, an aspect ratio of 95 and a σg of 1.88, and a light scattering transmittance of 31.
The light transmittance was 0% and the total light transmittance was 91.5%. In addition, when this powder was mixed with a foundation that is a cosmetic,
Since the crystals were too coarse, the feeling of roughness increased, the adhesion to the skin deteriorated, and the light scattering property was poor.

Comparative Example 2 1.872 g of special grade reagent barium chloride, 0.171 g of special grade reagent barium hydroxide and 1.96 g of special grade reagent sulfuric acid (molar ratio = 1/2) were dissolved in 1000 g of ion-exchanged water to obtain 0.01 mol. / L barium solution (mixture of barium chloride solution and barium hydroxide solution) and 0.02 mol
/ L sulfuric acid solution. The barium solution further contains 0.3 g of barium carbonate powder having a volume cumulative average particle diameter of 0.8 μm.
(0.03% by weight) was added. Then, a 2 liter flask was charged with a sulfuric acid solution (containing barium sulfate powder) and stirred at 200 rpm with a Teflon paddle at 95 ° C.
Heated up. Next, a barium solution (containing barium carbonate powder) heated to the same temperature was added dropwise thereto for 25 seconds. Then, stirring was continued for 3 minutes to complete the reaction.
The pH during the reaction was 1.8 (the initial stage of the reaction) to 1.9 (the final stage of the reaction). Next, it is cooled to room temperature, filtered through a 5C filter paper, washed with deionized water, and then washed with 1
After drying at 00 ° C. for 5 hours, 2.1 g of barium sulfate powder was obtained. The barium sulfate powder thus obtained is an undeveloped fine-grained crystal having a volume cumulative average particle diameter of 1.2 μm and a σg of 73, and has a light-scattering transmittance of 45.0% and a total light transmittance of It was 87.0%. In addition, when this powder was incorporated into a foundation, which was a cosmetic, it was found to be inferior in the feeling of use due to the fine particles, inferior sticking to the skin, and inferior in light scattering and transparency.

Comparative Examples 3 to 5 Reactions were carried out according to Comparative Examples 1 and 2 under the conditions shown in Tables 1 and 2. The results are summarized in Table 3. Further, when the powder of barium sulfate obtained in each Comparative Example was blended with a foundation which was a cosmetic, Comparative Example 3 had a grainy feeling because the crystals were rather coarse, and the light scattering property was also poor. Further, Comparative Example 4 had a low aspect ratio and thus had a rough feeling and was inferior in light scattering property. Furthermore, since Comparative Example 5 was fine particles, it had a bad feeling in use, and was inferior in light scattering property and transparency.

[0037]

Table 4 Example 11 Powder foundation: (Component) (wt%) (1) Remaining amount of mica (2) Powder obtained in Example 50 (3) Talc 20 (4) Titanium oxide 10 (5) Red iron oxide 0.8 (6) Yellow iron oxide 2.5 (7) Black iron oxide 0.1 (8) Liquid paraffin 8 (9) Beeswax 2 (10) Preservatives Appropriate amount (11) Fragrance Total 100

(Production method) Components (1) to (7) are mixed and pulverized. Transfer this to a high-speed blender, and then add ingredient (8)-
What was mixed and dissolved in (10) at 80 ° C. was added and mixed uniformly. The component (11) is added to this mixture and mixed, and then the mixture is ground again and passed through a sieve. This is compression-molded on a gold plate to obtain a powder foundation.

Example 12 A powder foundation is obtained in the same manner as in Example 11 except that the powder obtained in Example 4 is used in place of the powder obtained in Example 1.

[0040]

[Table 5] Comparative Example 6 (Component) (% by weight) (1) Remaining amount of mica (2) Nylon powder 10 (3) Talc 20 (4) Titanium oxide 10 (5) Red iron oxide 0.8 (6) Yellow iron oxide 2.5 (7) Black iron oxide 0.1 (8) Liquid paraffin 8 (9) Beeswax 2 (10) Preservative suitable amount (11) Perfume trace total 100

(Production method) Components (1) to (7) are mixed and ground. Transfer this to a high-speed blender, and then add ingredient (8)-
What was mixed and dissolved in (10) at 80 ° C. was added and mixed uniformly. The component (11) is added to this mixture and mixed, and then the mixture is ground again and passed through a sieve. This is compression-molded on a gold plate to obtain a powder foundation.

Test Example 1 With respect to the powder foundations obtained in Examples 11 and 12 and Comparative Example 6, 15 specialized panelists evaluated the difficulty of seeing spots and freckles, fineness of texture, bare skin feeling and covering power. . The evaluation of each item was carried out with 1 being unfavorable to 10 being all preferred, and an average of 15 evaluation points. The results are shown in Table 6.

[0043]

[Table 6]

As is clear from Table 6, in the cosmetics of the present invention, the plate-like barium sulfate compounded therein has a large light-scattering transmittance, so that when applied to the skin, it is difficult to see color spots, freckles, and other color irregularities. Also, you can feel that the fineness of the texture that expresses the texture of the skin is improved. Furthermore, it is possible to satisfy the bare skin feeling and the covering power at the same time, which cannot be satisfied at the same time with the conventional cosmetics.

[0045]

According to the production method of the present invention, the particle size distribution width evaluated by the volume cumulative average particle size and σg is relatively narrower than that of the prior art, and as apparent from the aspect ratio, it has a plate-like shape. Barium sulfate having a crystal structure can be obtained. Furthermore, this barium sulfate is also excellent in optical properties such as light scattering transmittance and total light transmittance. Further, according to the production method of the present invention, barium sulfate having such excellent properties can be stably supplied with good reproducibility.
Therefore, when barium sulfate obtained by the production method of the present invention, particularly barium sulfate having a plate-like crystal structure is used as a cosmetic ingredient such as a foundation, it improves the feeling of use such as elongation and stickiness, and further gives a transparent feeling. Since it is expensive, it retains the feeling of bare skin, while also making it difficult to see color irregularities such as spots and freckles.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshimitsu Koike 1450 Nishihama, Wakayama City, Wakayama Prefecture Kao Mizuken Dormitory (72) Inventor Itsuro Tsukahara 620-502 Aiya, Iwade Town, Naga-gun, Wakayama Prefecture

Claims (6)

[Claims] 1. Each concentration at the start of the reaction is 0.00
1 to 0.1 mol / l, and the molar ratio is 1 to 10
The barium compound and the sulfuric acid compound, which are 5/1, were mixed with each other in an amount of 0.
In the presence of 0002 to 0.02% by weight of hardly soluble crystallites, p
A method for producing barium sulfate, characterized in that the reaction is carried out under the conditions of H1.0 to 12.0 and reaction temperature of 50 to 100 ° C. 2. The barium compound is one or more selected from barium hydroxide, barium chloride, barium nitrate and barium acetate, and the sulfate compound is one or more selected from sulfuric acid, sodium sulfate, sodium hydrogensulfate and ammonium sulfate. And, the hardly soluble microcrystals have an average particle size of 0.0
The production method according to claim 1, which is at least one selected from barium sulfate having a thickness of 05 to 10 μm, zirconia, alumina, and titania. 3. Plate-shaped barium sulfate having an aspect ratio of 5 to 100, which is manufactured by the manufacturing method according to claim 1. 4. A volume cumulative average particle diameter produced by the production method according to claim 1 or 2, which is 3.0 to 10.0 μm, and a particle diameter and an average particle diameter at 84.13% under sieve accumulation. Plate-like barium sulfate having a ratio of 1.3 to 1.8. 5. A light-scattering transmittance of 55% or more when a thin film having a powder concentration of 20% by weight and a thickness of 15 μm, which is manufactured by the manufacturing method according to claim 1 or 2, is formed, and Plate-shaped barium sulfate having a light transmittance of 88% or more. 6. A cosmetic containing the plate-shaped barium sulfate according to claim 3, 4 or 5.