JP2880373B2 - Apatite composite particles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to apatite composite particles having excellent ultraviolet absorbing ability and oil / fat absorbing ability and used for cosmetic raw materials and the like.

[0002]

_2. Description of the Related Art Conventionally, hydroxyapatite [Ca ₁₀ (PO ₄ ) ₆ (OH) ₂ ], which is a kind of apatite, has been disclosed in Japanese Unexamined Patent Publication (Kokai) No. 63-27411. It is known that free fatty acids, which are sebum waste products that have an adverse effect on the skin, can be effectively adsorbed and removed from the skin. In order to make effective use of such oil-fat-adsorbing ability, the above-mentioned hydroxyapatite is formed into a powder having an average particle diameter of 20 μm or less, and is blended in a skin external preparation such as cosmetics.

[0003] In recent years, as the harmfulness of ultraviolet rays to the skin has been recognized, ultraviolet absorbers have been added to skin external preparations. Apatite composite particles supporting titania (TiO ₂ ) as such an ultraviolet absorber are disclosed in JP-A-5-32518.

[0004] Such apatite composite particles are obtained by mixing titania with the above-mentioned slurry of hydroxyapatite, and granulating the mixture by spray drying or the like. Therefore, the apatite composite particles have the excellent oil-and-fat adsorption ability of hydroxyapatite and the ultraviolet absorption ability of titania.

[0005]

However, in the above-mentioned conventional apatite composite particles, since hydroxyapatite does not have an ultraviolet absorbing ability, it has an inferior ultraviolet absorbing ability as compared with titania alone, and is not sufficient as a skin external preparation. There is no problem.

[0006] Further, when titania is mixed with a slurry of hydroxyapatite and the mixture is granulated to produce apatite composite particles, the shape is hardly spherical and easily formed into an irregular shape. There is also a problem of inferior usability such as "slip".

[0007] Therefore, an object of the present invention is to provide apatite composite particles having a shape closer to a true sphere, good "slip" and "glue" on the skin, and having a higher ultraviolet absorbing ability.

[0008]

Means for Solving the Problems In view of the above problems, the present inventor has studied various substances. As a result, the use of ceria, which has not been conventionally known as a cosmetic material, for apatite makes it possible to obtain oils and fats contained in apatite. The present inventors have discovered that they have a high ultraviolet absorption ability while maintaining the adsorption ability, and completed the present invention.

In order to solve the above-mentioned problems, the apatite composite particles of the present invention are obtained by mixing ceria (CeO ₂ ) particles with an apatite slurry containing apatite fine particles of a predetermined concentration and granulating them. It is characterized by.

Apatite in the apatite fine particles is a group of substances represented by the general chemical formula M ₁₀ (ZO ₄ ) ₆ X ₂ , where M is Ca, Pb, Ba, Sr, Cd, Z
n, Ni, Mg, Na, K, Fe, and at least one from among the elements of Al, as _{ZO 4, PO 4, AsO 4} ,
VO ₄ , SiO ₄ or CO ₃ and X as F, O
It is composed of at least one of H, Cl, Br and O elements or atomic groups.

In order to obtain apatite composite particles having a large specific surface area, it is desirable that the primary particles of the apatite fine particles have a particle size of 0.1 μm or less. Further, the ceria particles are preferably in the form of powder or sol, and the average particle diameter is desirably 20 μm or less.

It is desirable that the apatite slurry and the ceria particles be mixed at room temperature. This is because pH adjustment is easier under room temperature conditions, and when the temperature during mixing is high, apatite crystallizes or apatite components are eluted, making granulation and pH adjustment difficult. This is because

On the other hand, by changing the content of the apatite fine particles in the apatite slurry within the range of 1 to 90% by weight, apatite composite particles having a desired average particle size can be obtained. If the amount of apatite microparticles in the apatite slurry exceeds 90% by weight, the viscosity of the apatite slurry becomes high, which is inappropriate for granulation. If the amount is less than 1% by weight, it takes time to remove the solvent of the apatite slurry, and Is uneconomical.

In addition, the content of the apatite fine particles in the apatite slurry is preferably 5 to 20% by weight in view of the ease of handling of the apatite slurry and the desired average particle size of the obtained apatite composite particles.

As a granulation method, if the obtained particles are substantially spherical and the specific surface area can be increased,
Although not particularly limited, for example, a spray-drying granulation method can be used. Alternatively, a granulation method obtained by freeze-drying and then pulverization, or a high-speed stirring-type granulation method may be used.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. First, hydroxyapatite (Hydroxy Apatite, a kind of apatite)
Hereinafter, a method for preparing a slurry composed of fine particles of HAp) will be described. A calcium hydroxide suspension obtained by stirring a calcium hydroxide suspension to a pH of about 11 by dropping a 2 to 4 times diluted phosphoric acid aqueous solution is added. The suspension was prepared. By adjusting the pH of the calcium hydroxide suspension to pH 10 to 9 by dropping a phosphoric acid aqueous solution diluted 5 times or more, a slurry containing HAp fine particles having an average particle size of about 0.1 μm was obtained.

Example 1 The above slurry was diluted with ion-exchanged water to obtain a HAp slurry prepared so that the HAp concentration became 20% by weight. To the HAp slurry, 10% by weight of cerium (IV) oxide (CeO _2; hereinafter, referred to as ceria) (manufactured by Nikki Corporation, average particle size, 0.3 μm) as ceria particles dispersed in ion-exchanged water was added. And mixed with a stirring motor for 1 hour to obtain a mixture slurry.

As shown in FIG. 1, the mixture slurry 3 containing the HAp particles 1 and the ceria powder 2 is sprayed by a metering pump 4 using a spray dryer (L-produced by Okawara Kakoki Kikai Co., Ltd.).
8) Supply to 5. The atomizer 6 of the spray dryer 5 was rotated at a high speed, and the mixture slurry 3 was sprayed into a hot air stream dried at a high temperature in the spray dryer 5 to perform granulation and drying by a spray granulation method.

Ceria-containing HAp obtained by granulation drying
The substantially spherical apatite composite particles 7 as fine powders were classified and collected by a cyclone 8 so that the average particle diameter became 8 to 12 μm. The ultrafine powder that could not be collected by the cyclone 8 was separately collected by a bag filter (not shown).

The operating conditions in the above-mentioned spray granulation are as follows. The supply amount of the mixture slurry 3 to the spray drier 5 by the metering pump 4 is set to 1 to 3 kg / h, and the electric heater 10 is supplied through the air filter 9.
The temperature and flow rate of the hot air for drying heated by the above are such that the inlet temperature of the hot gas chamber 11 in the spray dryer 5 is 200 to 250 ° C., and the outlet temperature in the discharge hole 12 of the spray dryer 5 connected to the cyclone 8 is 100. C., and the rotation speed of the atomizer 6 was set within the range of 10,000 to 37,000 rpm.

Further, using two types of spray dryers (FOC-20, OD-25G, FOC-25, OC-25, manufactured by Okawara Kako Kikai Co., Ltd.) obtained by scaling up the spray dryer 5,
Apatite composite particles were prepared in the same manner as described above except that the supply amount of the mixture slurry 3 was 100 kg / hr. As a result, apatite composite particles similar to the apatite composite particles 7 obtained by the spray dryer 5 were obtained.

The apatite composite particles 7 thus obtained have a high fat and oil adsorbing ability and an ultraviolet absorbing ability.
Furthermore, the "glue" and "slip" on the skin were good, and it could be used as an external preparation for skin such as cosmetics.

Example 2 Instead of the ceria powder in Example 1, ceria sol as ceria particles (trade name: Neidral W-15, manufactured by Taki Kagaku Co., Ltd.) was used, and the compounding amount was 10% by weight. % (Solid content), and the operation was carried out under the same conditions as in Example 1 to obtain apatite composite particles 7 which were substantially spherical and had an average particle size of 8 to 12 μm.

As shown in FIG. 4, the apatite composite particles 7 obtained in this manner are mostly spherical, but some of the particles have a depressed center.
However, the "paste" and "slip" on the skin were good.

Example 3 Instead of the ceria powder in Example 1, ceria sol (trade name: Neidral U-15, manufactured by Taki Kagaku Co., Ltd.) was used as ceria particles, and the compounding amount was 10% by weight. % (Solid content), and the operation was carried out under the same conditions as in Example 1 to obtain apatite composite particles 7 which were substantially spherical and had an average particle size of 8 to 12 μm.

The apatite composite particles 7 thus obtained were spherical, as shown in FIG. 5, and the “glue” and “slip” on the skin were even better than those of Example 2. . Table 1 shows the specifications of each ceria sol.

[0027]

[Table 1] The generated phases of the apatite composite particles 7 obtained in Examples 2 and 3 were examined by using a powder X-ray diffraction method. The result is shown in FIG. As is clear from the results, each peak, for example, peak A appearing in the X-ray diffraction pattern of ceria shown in FIG.
Each of the apatite composite particles 7 shown in FIGS. 2B to 2C is overlapped with the X-ray diffraction pattern of HAp alone shown in FIG.
In the X-ray diffraction pattern, it was identified that each of the obtained apatite composite particles 7 was a composite of HAp and ceria.

Next, the ultraviolet absorptivity of the apatite composite particles 7 obtained in each of Examples 2 to 3 was measured. As a measurement method, the apatite composite particles 7 as a sample are continuously scanned and irradiated with light (200 nm to 500 nm) substantially in the ultraviolet region, and the reflectance from the sample is measured. The method of measuring the absorption was used. For comparison, the UV absorptivity of the HAp granules and the titania granules was measured in the same manner.

FIG. 3 shows the results. As is clear from these results, each apatite composite particle 7 is HAp
It shows significantly higher UV absorption than that of single-granulated particles, and has almost the same UV-absorbing capacity as titania single-granules, despite the ceria content of 10% by weight. Indicated.

Next, the ability of each apatite composite particle 7 obtained in each of Examples 2 to 3 to adsorb fats and oils was measured.
The measurement of the fat and oil adsorption capacity was carried out by using oleic acid and oleyl oleate as model substances of fats and oils.
The measurement was performed according to the measurement method described in Japanese Patent Publication No. 11 and the oil / fat adsorption ability of particles of HAp alone or other ceramics alone was measured for comparison. Table 2 shows the results.

[0031]

[Table 2] As is evident from Table 2, the ceria-containing apatite composite particles 7 prepared using 10% by weight of ceria sol have improved adsorbability to fats and oils compared to the conventionally used apatite fine particles alone and other ceramic particles. Was shown.

As described above, the ceria-containing apatite composite particles 7 can be substantially spherical in shape, and have a larger size than conventional titania-containing apatite composite particles.
It has good "slip" and "glue" to the skin, and has high ultraviolet absorbing ability.

In addition, the ceria-containing apatite composite particles 7 have higher oil and fat adsorption ability than HAp alone particles. Therefore, the apatite composite particles 7 of each of the above embodiments can adsorb more fats and oils contained in sweat and the like, and can remove fats and oils waste products such as free fatty acids which have a bad effect on the skin from the skin to prevent makeup collapse and acne. It can be prevented and can be suitably used for external preparations for skin (pharmaceuticals, non-medical use, cosmetics, etc.).

In addition, since the apatite composite particles 7 of each of the above embodiments have a high ultraviolet ray absorbing ability, they can effectively block ultraviolet rays to protect the skin, and can be applied to cosmetics and the like applied to the skin such as foundations. Can be more preferably used.

Since HAp as a base material of the apatite composite particles 7 is a constituent material such as bone in a living body, the obtained apatite composite particles 7 also have a sufficient biocompatibility, and can be used for dental materials and bone filling. It can be applied to materials and the like.

[0036]

As described above, the apatite composite particles of the present invention are granulated by mixing ceria (CeO ₂ ) particles with an apatite slurry containing apatite fine particles of a predetermined concentration.

Therefore, the apatite composite particles can have a more spherical shape while maintaining the high fat and oil adsorbing ability of the apatite fine particles, and can have a higher ultraviolet absorbing ability than conventional ones due to ceria. Therefore, it has an effect that it can be suitably used as an external skin material such as cosmetics.

[Brief description of the drawings]

FIG. 1 is a schematic structural view of a spray dryer used when producing apatite composite particles of the present invention.

FIG. 2 is an X-ray analysis diagram of the apatite composite particles of Examples 2 and 3.

FIG. 3 is a graph showing the ultraviolet absorptivity of the apatite composite particles of Examples 2 and 3.

FIG. 4 is a photograph as a drawing showing the structure of the apatite composite particles of Example 2 of the present invention.

FIG. 5 is a photograph substituted for a drawing showing the structure of the particles of the apatite composite particles of Example 3 of the present invention.

[Explanation of symbols]

 1 apatite fine particles 2 ceria powder (ceria particles) 7 apatite composite particles

Continued on the front page (51) Int.Cl. ⁶ Identification code FI A61K 7/42 A61K 7/42 B01J 20/04 B01J 20/04 A

Claims (1)

(57) [Claims] 1. Apatite composite particles characterized by being granulated by mixing ceria (CeO ₂ ) particles with an apatite slurry containing apatite fine particles at a predetermined concentration.