JPH11278816A - Non-crystalline calcium phosphate particles, their production and aerosol type cosmetic containing same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain non-crystalline calcium phosphate particles excellent in ability to adsorb the odors of human perspiration and feet, in particular fatty acids such as valeric acid, butyric acid and caproic acid and suitable for use as a deodorant material in aerosol type cosmetics excellent in touch. SOLUTION: When an aq. soln. of phosphoric acid is added to a suspension contg. 1-20 wt.% calcium hydroxide and the pH is adjusted to 5-11 to synthesize non-crystalline calcium phosphate, temp. control is carried out so that the temp. of the suspension at the time of synthesis does not exceed 50 deg.C and the resultant non-crystalline calcium phosphate slurry is granulated to produce the objective non-crystalline calcium phosphate particles having ability to adsorb at least one fatty acid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to amorphous calcium phosphate particles characterized in that they absorb and deodorize human sweat and foot odors, a method for producing the same, and an aerosol cosmetic containing the particles. More specifically, an aerosol-type cosmetic having an excellent ability to adsorb fatty acids such as butyric acid, caproic acid, and valeric acid, and particularly having an excellent touch, and an amorphous calcium phosphate which can be suitably used for the smell of human sweat and feet. The present invention relates to particles and a method for producing the particles.

[0002]

2. Description of the Related Art Hitherto, it has been described that many of the causes of malodors derived from living bodies such as axillary odor, sweat odor, hair odor, and physiological odor are caused by bacterial decomposition of sweat (for example,
Labows and Kligman et al., J. Soc. Cosmet. Chem., 34.
2) ”p. 193). That is, sweat odor, armpit odor,
Foot odors and the like are conceivable, but these are produced by sweat that is the base of the odor and skin-resident bacteria that produce the odor. Sweat is secreted from sweat glands, and sweat glands are mainly classified into eccrine glands and apocrine glands. The sweat secreted from the eccrine glands and the apocrine glands is called eccrine sweat and apocrine sweat, respectively. Apocrine sweat contains organic substances (lipids, proteins)
, And the secreted fresh sweat is odorless,
In the skin surface, these organic substances are decomposed by indigenous skin bacteria and turned into odorous substances. Body odor is mainly caused by this odor, and these decomposition products include capric acid (CH
₃ (CH ₂ ) ₈ COOH), caproic acid (CH ₃ (CH ₂ ) ₄ COOH), isovaleric acid ((CH ₃ ) ₂ CHCH ₂ COOH), butyric acid (CH ₃ (CH ₂ ) ₂ COOH), propionic acid (CH ₃ CH ₂ COOH), enanthic acid (CH ₃ (CH ₂ ) ₅ COO
H), pelargonic acid (CH ₃ (CH ₂ ) ₇ COOH), and valeric acid isomers such as ethylmethyl acetic acid (C ₂ H ₅ (CH ₃ ) CHCOOH), trimethyl acetic acid ((CH ₃ ) ₃ CCOOH), Lactic acid (CH ₃ CH (OH) COO
Fatty acids such as H) are specifically detected, and mercaptans, amines, ammonia and the like have been confirmed. Ecrine sweat is also decomposed by resident bacteria and becomes odorous,
Due to the low content of organic matter, it is essentially different from unpleasant odors. However, water, which is a major component, plays an indirect role in the generation and emission of body odor, such as promoting the growth of bacteria and increasing the emission of unpleasant odors when the water evaporates.

[0003] For this reason, there are a number of products on the market for treating malodors derived from living organisms, but these products are often deodorants containing antiperspirants, bactericides, masking agents and the like. . As an antiperspirant function to suppress sweat, there is a method of suppressing sweating by compounding a drug having a relatively strong astringent action, and citric acid, various aluminum salts and zirconium salts are often compounded, and particularly, Aluminum chlorohydrate is most common. It is used as a dosage form in a liquid form or as a powder in a powder or aerosol powder.

As an antibacterial function for suppressing the growth of bacteria indigenous to the skin, an antibacterial agent is used for the purpose of suppressing the growth of bacteria that produce a substance causing body odor and obtaining an anti-odor effect. Antibacterial agents such as benzalkonium chloride and chlorhexidine hydrochloride are generally used as the active ingredient.

[0005] The deodorant function for suppressing the generated body odor includes:
It is conceivable that the specific odor is not emitted by changing the fatty acid, which is the cause, to a metal salt. When zinc white is made to act on fatty acids, which are odorous substances, zinc salts of fatty acids are formed and odors are eliminated. As for the masking by the scent, the masking can be performed by using a perfume or an eau de cologne if the body odor is weak.

[0006] However, the above-mentioned aluminum chlorohydrate may be hydrolyzed in an aqueous system to generate hydrochloric acid, which may cause corrosion of the aerosol can. Furthermore, with an aerosol-type cosmetic that suppresses the generation of perspiration, which is a source of offensive odor, it is impossible from a physiological point of view to completely control perspiration, It has a drawback that it requires an unnatural load, and furthermore, it is not possible to control the already generated sweat odor in view of its action mechanism.

[0007] In addition, since it is pointed out that there is a problem in the safety of the fungicide used in the compound having a fungicidal effect, the fungicide is added to the deodorant at a concentration that can achieve a sufficient deodorant effect. It has the disadvantage that it cannot be blended. On the other hand, the masking agent has a drawback that when mixed with sweat odor, it may rather generate an unpleasant odor. Therefore, the deodorant containing the antiperspirant, the bactericide and the masking agent is not sufficiently satisfactory in terms of effectiveness, safety and use.

To solve these problems, Japanese Patent Publication No.
Japanese Patent No. 64064 discloses a "deodorant" in which a composite powder comprising a synthetic resin and hydroxyapatite is used as a deodorant active substance. This deodorant is, specifically, a composite powder in which the surface of a synthetic resin particle is coated with hydroxyapatite particles smaller than the particle size of the particle. In order to solve the above problems, the present inventors have already proposed a deodorant containing amorphous calcium phosphate as a deodorant active substance described in JP-A-8-266600.

However, the deodorant disclosed in Japanese Patent Publication No. 5-64064 requires the use of a composite powder consisting of a synthetic resin and hydroxyapatite, although the reason is not described. Since it is necessary to coat the surface of the resin particles with the hydroxyapatite particles smaller than the particle diameter of the particles and use them, they may be separated and become inhomogeneous especially when used as an aerosol, and in addition, generally In particular, hydroxyapatite, which is crystalline, has a low ability to adsorb odors and the like derived from living organisms, and has a problem that it has no ability to adsorb valeric acid.

On the other hand, the deodorant described in Japanese Patent Application Laid-Open No. 8-266600 is an excellent deodorant which has a high adsorption capacity for malodors derived from living organisms and can exhibit a deodorizing effect. In order to improve the ability to adsorb fatty acids such as valeric acid, butyric acid, and caproic acid, which are required as a product, sufficient effects may not be achieved unless a considerable amount of deodorant active substances are added. The problem that the degree decreases.

[0011]

DISCLOSURE OF THE INVENTION The present invention is directed to an aerosol-type cosmetic which is excellent in the ability to adsorb human sweat and foot odors, especially fatty acids such as valeric acid, butyric acid and caproic acid, and is excellent in feel. It is an object of the present invention to provide amorphous calcium phosphate particles that can be suitably used as a odor active substance.

[0012]

The present inventors have conducted various studies on amorphous calcium phosphate particles useful as a deodorant active substance in order to solve the above-mentioned problems. When synthesizing amorphous calcium phosphate by adding an aqueous solution of phosphoric acid to the suspension and adjusting the pH to 5 to 11, control the temperature of the suspension during synthesis so as not to exceed 50 ° C. Amorphous calcium phosphate particles obtained by granulating the amorphous calcium phosphate slurry obtained by the above method are biologically safe, and in a short amount of fatty acids such as valeric acid, butyric acid, and caproic acid in a small amount. The inventors have found that the present invention has a unique action and effect of showing adsorption, and have completed the present invention.

That is, the present invention includes the following inventions. (1) Amorphous calcium phosphate particles having an ability to adsorb at least one fatty acid. (2) The amorphous calcium phosphate particles according to (1), wherein the fatty acid has 10 or less carbon atoms. (3) The amorphous calcium phosphate particles according to (1), wherein the fatty acid is at least one selected from the group consisting of valeric acid, butyric acid, and caproic acid.

(4) Amorphous calcium phosphate particles having an ability to adsorb valeric acid, butyric acid and caproic acid. (5) The amorphous calcium phosphate particles according to any one of (1) to (4), wherein the average particle size is 0.5 to 100 μm. (6) The amorphous calcium phosphate particles according to any one of (1) to (5), wherein the specific surface area is 40 m ² / g or more. (7) The above-mentioned (1) to (1), which are not fired.
The amorphous calcium phosphate particles according to any one of (6).

(8) 1-20% by weight of calcium hydroxide
When adding a phosphoric acid aqueous solution to the suspension containing the solution and adjusting the pH to 5 to 11 to synthesize amorphous calcium phosphate,
A method for producing amorphous calcium phosphate particles, comprising granulating an amorphous calcium phosphate slurry obtained by controlling the temperature of the suspension during synthesis so as not to exceed 50 ° C.

(9) During the synthesis of the amorphous calcium phosphate slurry, a neutral or weakly alkaline water-soluble polymer dispersant is added to the calcium hydroxide suspension to form a mixed solution, and the mixed solution is stirred. The method according to (8), wherein the pH is adjusted to 5 to 11 by dropwise addition of a phosphoric acid aqueous solution while the pH is adjusted to 5 to 11. (10) An aerosol cosmetic comprising the amorphous calcium phosphate particles according to any one of (1) to (7).

[0017]

DETAILED DESCRIPTION OF THE INVENTION The amorphous calcium phosphate (Amorphous Calcium Phosphate: hereinafter sometimes abbreviated as ACP) in the present invention is a phosphoric acid represented by the formula Ca ₃ (PO ₄ ) ₂ .nH ₂ O. Tricalcium, particularly one whose crystal structure is amorphous. The amorphous calcium phosphate may be a composite of one or more metal oxides such as titanium oxide, zinc oxide, and cerium oxide,
The type of metal oxide is not particularly limited.

In the present invention, "having the ability to adsorb at least one fatty acid" means that the fatty acid has a predetermined concentration, for example, about 200 ppm (for example, valeric acid, butyric acid, caproic acid, etc. Fatty acid), the ability to reduce the initial concentration of at least one fatty acid by 30% or more within one hour using amorphous calcium phosphate particles in an amount of 5 g or less per liter of air, more preferably 1 g The ability to reduce the initial concentration of at least one fatty acid by 30% or more within 30 minutes using the following amounts of amorphous calcium phosphate particles:

The fatty acid to be used in the present invention is not particularly limited as long as it exhibits an odor, and preferably includes fatty acids having 10 or less carbon atoms, such as valeric acid, butyric acid, and caproic acid. As the amorphous calcium phosphate particles of the present invention, those exhibiting the above-mentioned adsorption ability to all of valeric acid, butyric acid and caproic acid are particularly preferable. Valeric acid in the present invention includes at least one or more of isovaleric acid, normal valeric acid and the like. Further, butyric acid is at least one of isobutyric acid and normal butyric acid, and caproic acid is at least one of normal caproic acid and the like.
Including more than species.

The ACP particles of the present invention are obtained by adding an aqueous solution of phosphoric acid to a suspension containing 1 to 20% by weight of calcium hydroxide and adjusting the pH to 5 to 11 to obtain an amorphous calcium phosphate slurry. It can be prepared by granulation, but it is necessary to control the temperature of the suspension so as not to exceed 50 ° C. during the synthesis of the amorphous calcium phosphate slurry. If the temperature of the suspension at the time of synthesis exceeds 50 ° C., it is not clear why, but it is not possible to obtain amorphous calcium phosphate particles capable of exhibiting excellent fatty acid adsorption ability.

In order to control the temperature of the suspension at the time of the synthesis so as not to exceed 50 ° C., the suspension containing calcium hydroxide used in the synthesis may be cooled before use or cooled. The temperature of the suspension during the synthesis can be controlled by using a reactor equipped with a cooling method such that the temperature does not exceed 50 ° C. The average particle size of the primary particles of ACP contained in the slurry is preferably less than 0.1 μm so that the ACP particles obtained by granulating the slurry obtain a large specific surface area. The particle size in the present specification is measured by a laser diffraction method.

In addition, a neutral or weakly alkaline water-soluble polymer dispersant (eg, a weakly alkaline ammonium triacrylate) is added to the stirred calcium hydroxide suspension during the synthesis of the amorphous calcium phosphate slurry. After that, the pH of the mixed solution may be adjusted to 5 to 11 by adding a phosphoric acid aqueous solution dropwise while stirring the mixed solution. In this case also, it is necessary to control the temperature of the suspension so as not to exceed 50 ° C. The water-soluble polymer dispersant is added to avoid agglomeration of primary ACP particles having a particle size of less than about 0.1 μm contained in the slurry. On the other hand, 0.
It is 1 to 10% by weight, preferably 0.1 to 3% by weight.

ACP particles having a desired average particle size can be obtained by granulating the amorphous calcium phosphate slurry obtained by the above steps. ACP
In order to maximize the specific surface area of the particles, ACP
The average particle diameter of the particles is 0.5 to 100 μm, especially 0.5 to 100 μm.
It is desirable that the thickness be 50 μm. In the granulation method, the obtained ACP particles are porous and have a specific surface area of about 40 m ^2.
g / g or more, preferably 50 to 150 m ² / g, is not particularly limited, but a spray drying granulation method capable of easily producing a porous body is preferable. The shape of the ACP particles is not particularly limited, but is preferably substantially spherical from the viewpoint of use on the skin.

The ACP particles of the present invention were found to be tricalcium phosphate [formula: Ca ₃ (PO ₄ ) ₂ .nH ₂ O] containing water of crystallization from the diffraction pattern obtained by the powder X-ray diffraction method. Since the pattern is broad, it has been confirmed that the pattern is amorphous. Further, since the ACP particles contain water of crystallization, they are electrostatically active substances, so that they can exhibit the effect of adsorbing various bacteria and viruses whose surface is charged.

The ACP of the present invention is characterized in that it is not fired. By not firing, unlike hydroxyapatite which is crystalline, very fine particles can be obtained, the specific surface area of the particles can be kept large, and an excellent adsorption effect can be exhibited. The ACP particles of the present invention can be incorporated into an aerosol-type cosmetic as a deodorant active substance. The aerosol type cosmetics referred to in the present invention include, for example, makeup cosmetics such as foundations, hair cosmetics such as setting agents, lotions, packs, sunscreens, basic cosmetics such as makeup bases, deodorants, and body powders. , Aftershave lotion,
Pre-shave lotion, antiperspirant spray, foot spray, etc. are included.

When the ACP particles of the present invention are incorporated into an aerosol type cosmetic, the ACP particles may be used as they are or may be subjected to a surface treatment beforehand. Examples of the surface treatment include fluorine compound treatment, silicone treatment, metal soap treatment, acylated lysine treatment, oil agent treatment, silane treatment, amino acid treatment, wax treatment, metal oxide treatment, etc. Any processing can be used as long as it is performed.

In the aerosol type cosmetic of the present invention, ACP
Along with the particles, oils, powders (pigments, pigments), resins, surfactants, adhesives, preservatives,
Components such as fragrances, ultraviolet absorbers (including organic and inorganic), humectants, physiologically active ingredients, salts, solvents, antioxidants, chelating agents, neutralizing agents, pH adjusters, etc. can be compounded. is there.

Examples of the oily agent include those which can be used in cosmetics, for example, higher alcohols such as cetyl alcohol, isostearyl alcohol, lauryl alcohol, hexadecyl alcohol, octyl dodecanol, isostearic acid, undecylene and the like. Acids, fatty acids such as oleic acid, polyhydric alcohols such as glycerin, sorbitol, ethylene glycol, propylene glycol, and polyethylene glycol, myristyl myristate, hexyl laurate, decyl oleate, isopropyl myristate, hexyldecyl dimethyloctanoate, monostearin Esters such as glycerin acid, diethyl phthalate, ethylene glycol monostearate, octyl oxystearate, liquid paraffin, isoparaffin, petrolatum, Run like hydrocarbons, lanolin, reduced lanolin, waxes such as carnauba wax, mink oil, cacao butter, coconut oil, palm kernel oil, camellia oil, sesame oil, castor oil, and oils such as Oripu oil.

Examples of other types of oils include, for example, dimethylpolysiloxane, methylhydrogenpolysiloxane, methylphenylpolysiloxane, polyether-modified organopolysiloxane, alkyl-modified organopolysiloxane, sugar-modified silicone, glyceryl-modified Silicone, amodimethicone, amino-modified organopolysiloxane, silicone gel, acrylic silicone,
Examples include silicone compounds such as trimethylsiloxysilicic acid and silicone RTV rubber.

Further, examples of the fluorinated oil agent include fluorocarbons such as perfluorodecalin, alcohols such as perfluoropolyether, fluorinated pitch, and fluoroalcohol having a perfluoroalkyl chain; Phosphoric acid esters such as ethanolamine salts, carboxylic acids having a fluoroalkyl chain, fluoroalkyl-modified silicone, fluorine / polyether co-modified silicone, and fluorinated silicone resins are exemplified.

Examples of the powders include any powders that can be used for cosmetics, such as resin powders such as nylon beads, silicone beads, Teflon, and silicone elastomers, yellow iron oxide, red iron oxide, and black oxide. Iron, chromium oxide,
Cobalt oxide, carbon black, ultramarine, navy blue, zinc oxide, titanium oxide, zirconia, silicon oxide, aluminum oxide, cerium oxide, mica titanium, barium sulfate, calcium carbonate, magnesium carbonate, aluminum silicate, magnesium silicate, silicon carbide, Organic dyes, lakes, fine particle titanium oxide, fine particle zinc oxide, fine particle iron oxide, sericite, mica, talc, plate-like barium sulfate and the like.
Surface treatments such as silane coupling agent treatment, silane treatment, organic titanate treatment, acylated lysine treatment, fatty acid treatment, metal soap treatment, oil treatment, amino acid treatment, wax treatment, and metal oxide treatment may be used.

The surfactant may be any one that can be used in cosmetics, and examples thereof include anionic surfactants, cationic surfactants, nonionic surfactants, and betaine surfactants. Can be. Examples of the physiologically active component include anti-inflammatory agents, blood circulation promoters, vitamins, tyrosinase activity inhibitors, urea and the like.

Examples of the solvent include those which can be used in cosmetics, such as purified water, methanol, ethanol, isopropyl alcohol, ether, LPG, volatile silicone, light liquid isoparaffin, and CFC alternative. . In addition, it is also possible to use mineral water instead of purified water. When the ACP particles of the present invention are blended in an aerosol type cosmetic, in order to exhibit a sufficient deodorizing effect, the blending amount is desirably 0.1 to 50% by weight based on the total amount of the makeup, and particularly 0%. .
The content is preferably 5 to 20% by weight.

[0034]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples. (Example 1) ACP particles according to the present invention were produced as follows. FIG. 1 schematically shows a spray-drying granulation apparatus used for producing the ACP porous particles. In FIG. 1, 9 is an air filter, 10 is an electric heater, and hot air heated by the electric heater 10 through the air filter 9 enters the spray dryer 5 from the hot gas chamber 11 and is atomized by the spray dryer 5. The slurry 3 sprayed by the nozzle 6 is dried and granulated while flowing out from the discharge hole 12 toward the cyclone 8.

After cooling a 10% suspension of calcium hydroxide under stirring to about 10 ° C., 0.5% by weight of a weakly alkaline ammonium triacrylate as a water-soluble polymer dispersant is added to the mixed solution. I got While stirring the obtained mixed solution, a phosphoric acid aqueous solution obtained by diluting an 85% phosphoric acid solution ten times with water was added dropwise, and the pH was adjusted to 10 to synthesize an ACP slurry. The temperature of the suspension during the synthesis was up to 40 ° C. and did not exceed 50 ° C. Thus, a slurry containing primary ACP particles having a particle size of less than about 0.1 μm was obtained.

The obtained slurry 3 containing the primary ACP particles 1 was supplied to an atomizer 6 of a spray dryer (ODB-25G manufactured by Okawara Kakohki Co., Ltd.) 5 by a metering pump 4. The atomizer 6 was rotated at a high speed, the mixture slurry 3 was sprayed into a hot air stream for drying in the spray drier 5, and granulated by a spray drying granulation method. By this granulation, ACP porous particles 7 were obtained. The obtained ACP porous particles 7 were collected by a cyclone 8. At this time, the ultrafine powder that could not be collected by the cyclone 8 was separately collected by a bag filter (not shown).

The operating conditions for the granulation were as follows. The supply amount of the mixture slurry 3 by the metering pump 4 is 1 to 3 kg / h, and the temperature of the hot air heated by the electric heater 10 through the air filter 9 is 150 to 350 kg at the inlet temperature of the hot gas chamber 11. The temperature at the outlet of the discharge hole 12 connected to the cyclone 8 was controlled so as to always exceed 80 ° C., and the rotation speed of the atomizer 6 was set in the range of 10,000 to 30,000 rpm. The ACP porous particles 7 thus obtained became porous spherical by using the spray drying granulation method, and the average particle diameter was 12 μm. The specific surface area of the ACP porous particles 7 was measured by the BET method.
It was 5.1 m ² / g.

Comparative Example 1 Calcium hydroxide 1 under stirring
The 0% suspension was stirred in a water bath while maintaining the temperature at 80 ° C., and a phosphoric acid aqueous solution obtained by diluting an 85% phosphoric acid solution ten times with water was added dropwise to adjust the pH to 7. A slurry containing hydroxyapatite particles of less than 0.1 μm was obtained. Thereafter, in the same manner as in Example 1, granulation was performed by a spray drying granulation method. When the specific surface area of the hydroxyapatite porous particles 7 was measured by the BET method, the specific surface area was 13 m ² / g.

(Comparative Example 2) The ACP porous particles obtained in Example 1 were fired at 800 ° C for 3 hours to obtain hydroxyapatite particles. When the specific surface area of the hydroxyapatite porous particles 7 was measured by the BET method, the specific surface area was 23.28 m ² / g.

(Test Example) An isovaleric acid gas adsorption performance test was performed on the ACP porous particles prepared in Example 1 and the hydroxyapatite porous particles prepared in Comparative Examples 1 and 2. Further, the gas adsorption performance of the ACP porous particles for n-butyric acid gas and caproic acid gas was also tested. Test Items and Test Method 0.5 g of each sample was placed in a 5-liter Tedlar bag and sealed. Thereafter, the test gas was charged, and the residual concentration of the test gas was measured by gas chromatography-mass spectrometry (GC-MS) at each elapsed time. Tables 1, 2 and 3 show the results.
Shown in

Sample amount: 0.50 g Test gas type and concentration Isovaleric acid: 187 ppm (air balance) 5 liter n-butyric acid: 153 ppm (air balance) 5 liter Caproic acid: 189 ppm (air balance) 5 liter Measurement temperature: 23 ° C. Measurement time and number (for isovaleric acid gas): 30 minutes, 1 hour, 1.5 hours, and 2 hours after measurement 4 times Measurement time and number (for n-butyric acid gas and caproic acid gas) ): After 15 minutes, 30 minutes, 45 minutes, and 60 minutes, measured four times in total. Analysis method: Gas chromatography-mass spectrometry (GC-
MS) Apparatus: GCMS-QP5050 Analysis: M / Z = 60

[0042]

[Table 1]

[0043]

[Table 2]

[0044]

[Table 3]

From the above test examples, A obtained in Example 1
The CP porous particles exhibited an excellent ability to adsorb isovaleric acid, and the hydroxyapatite porous particles obtained in Comparative Examples 1 and 2 had a considerably low adsorption ability. Furthermore,
The ACP porous particles can adsorb 99.7% of the initial concentration in 15 minutes for n-butyric acid gas, and 99.9% of the initial concentration in 15 minutes for caproic acid gas.
Could be adsorbed.

Example 2 Using the ACP porous particles obtained in Example 1, a body powder foam was prepared according to the following formulation. Component A Squalane 1% by weight Polyoxyethylene cetyl ether 3% by weight 1,3-butylene glycol 1% by weight Ethyl alcohol 12% by weight Polymethylsilsesquioxane powder 5% by weight Component B Water 33% by weight ACP porous particles 15% % Component C 22% by weight of alternative CFCs 8% by weight of LPG After mixing component A, component B was added and further mixed. This was poured into an aerosol can, and mixed gas C was filled to obtain a product. This body powder form was excellent in feel (freshness) and excellent in sebum adsorption effect.

[0047]

The amorphous calcium phosphate particles of the present invention have an excellent deodorizing function because they have an excellent effect of adsorbing odors of human sweat and feet, especially fatty acids such as valeric acid, butyric acid and caproic acid. Which can be suitably used as a deodorant active substance in aerosol cosmetics.

[Brief description of the drawings]

FIG. 1 is a view showing an apparatus used for producing amorphous calcium phosphate particles of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Primary ACP particle 3 ... Slurry containing primary ACP particle 4 ... Metering pump 5 ... Spray dryer 6 ... Atomizer 7 ... ACP porous particle 8 ... Cyclone 9 ... Air filter 10 ... Electric heater 11 ... Hot gas chamber 12 ... Discharge hole

Claims (10)

[Claims] 1. Amorphous calcium phosphate particles having the ability to adsorb at least one fatty acid. 2. A fatty acid having 10 or less carbon atoms.
Amorphous calcium phosphate particles as described. 3. The amorphous calcium phosphate particles according to claim 1, wherein the fatty acid is at least one selected from the group consisting of valeric acid, butyric acid, and caproic acid. 4. Amorphous calcium phosphate particles having an ability to adsorb valeric acid, butyric acid, and caproic acid. 5. The amorphous calcium phosphate particles according to claim 1, wherein the average particle size is 0.5 to 100 μm. 6. The amorphous calcium phosphate particles according to claim 1, having a specific surface area of 40 m ² / g or more. 7. The amorphous calcium phosphate particles according to claim 1, which is not calcined. 8. An amorphous calcium phosphate is synthesized by adding an aqueous solution of phosphoric acid to a suspension containing 1 to 20% by weight of calcium hydroxide and adjusting the pH to 5 to 11 to prepare the suspension during the synthesis. A method for producing amorphous calcium phosphate particles, comprising granulating an amorphous calcium phosphate slurry obtained by controlling the temperature of a liquid not to exceed 50 ° C. 9. When synthesizing the amorphous calcium phosphate slurry, a neutral or weakly alkaline water-soluble polymer dispersant is added to the calcium hydroxide suspension to form a mixed solution, and the mixed solution is stirred. The method according to claim 8, wherein the pH is adjusted to 5 to 11 by dropwise addition of an aqueous phosphoric acid solution. 10. An aerosol-type cosmetic comprising the amorphous calcium phosphate particles according to claim 1. Description: