JP2010120863A - Deodorant agent for human body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a deodorant agent for a human body, providing good feeling in use and having high deodorant effects. <P>SOLUTION: The deodorant agent for the human body contains fine particle-shaped silica gel including zinc oxide fine particles produced by a production method including a micronized silica hydrogel slurry-preparing step comprising a hydrothermal pulverizing step for forming slurry of the micronized silica hydrogel having an average particle diameter of ≤100 μm by subjecting silica hydrogel in a slurry state having SiO<SB>2</SB>concentration of 5.0-15.0 mass% to hydrothermal treatment under stirring; a mixed slurry-forming step for obtaining mixed slurry of the silica hydrogel fine particles and the zinc oxide fine particles by introducing the zinc oxide fine particles in a primary particle state having an average particle diameter of 0.1-0.5 μm into the micronized silica hydrogel slurry; and a drying step for drying the mixed slurry. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a human body deodorant containing fine particulate silica gel containing zinc oxide fine particles.

Various skin external materials containing zinc oxide have been developed for the purpose of blocking ultraviolet rays and infrared rays, antibacterial, and deodorizing.
For example, an infrared blocking substance-containing cosmetic that shields infrared rays by containing zinc oxide having a large particle size (see Patent Document 1), and basic zinc carbonate and / or zinc oxide and oxycarbon as an antibacterial / deodorant component There exists an antibacterial / deodorant composition using an acid (see Patent Document 2).

In particular, a skin external material containing fine particles obtained by using zinc oxide fine particles as a starting material and composited with mother particles such as silica gel has transparency and blocks ultraviolet rays. Various studies have been conducted.
For example, it is assumed that the primary particles have substantially no catalytic activity, are highly transparent in the visible light region, and have high shielding properties in the ultraviolet region. Secondary particles) and ultraviolet shielding composite fine particles comprising child particles dispersed and immobilized in the mother particles are disclosed (see Patent Documents 3 and 4).
Also disclosed is a composite pigment in which the surface of an inorganic substance is coated with a crystalline zinc oxide film as being excellent in ultraviolet shielding ability and having good visible light transmittance. The pigment is obtained by dispersing an inorganic substance in an organic solvent containing an organic zinc and an unsaturated fatty acid, distilling off the solvent, and calcining at 400 to 700 ° C., for example, on silica of secondary particles. A composite pigment coated with zinc oxide is disclosed (see Patent Document 5).
In addition, a dispersion containing a silica sol as a secondary particle and a fine particle metal oxide or a metal oxide sol as a primary particle are assumed to have high dispersibility of the metal oxide and sufficient UV protection ability and transparency. There is disclosed a metal oxide / silica composite obtained by mixing (see Patent Document 6).

However, the external preparation for skin containing a powder in which metal fine particles are compounded with these secondary particles has a problem that it is unusable for daily use as a deodorant for human body having deodorant properties. .
In addition, a silica-coated ultrafine zinc oxide powder characterized by having ultrafine zinc oxide surface-coated with tetraethoxysilane, which is a silica raw material, has both transparency and ultraviolet shielding ability. (See Patent Document 7).

By the way, the following manufacturing method is disclosed as a manufacturing method of the fine particle silica gel using silica hydrogel (primary particle). First, a slurry in which the amount of water of the silica hydrogel relative to SiO ₂ is a specific mass ratio is hydrothermally pulverized by hydrothermal treatment, and dried by means such as a spray dryer. Next, a method for producing fine particle silica gel is disclosed in which metal compound fine particles are added to this slurry and dried to obtain silica gel containing metal compound fine particles (see Patent Document 8).
However, the fine-particle silica gel produced by the production method is mainly used as an ultraviolet blocking agent.

Further, a fine particulate silica gel having an average particle diameter of 1 μm to 200 μm, a moisture absorption rate of 20% by mass or less, and a metal compound content of 5 to 80% by mass is disclosed (see Patent Document 9).
However, the particulate silica gel, etc., is used as a material that improves the moisture adsorption in the air while maintaining a general oil absorption amount and has an easily disintegrating property, and has a deodorizing effect. It was not used as an agent.

  Therefore, various effects when the composite powder obtained by using zinc oxide fine particles as a starting material and composited with silica gel as a deodorant agent are not examined, and the composite powder is not applied to the human body. At present, there is no one used as a deodorant agent.

JP 2005-162695 A JP-A-10-328280 JP 09-100112 A Japanese Patent Laid-Open No. 08-12961 Japanese Patent Laid-Open No. 09-40884 International Publication No. 02/24153 Pamphlet International Publication No. 00/46152 Pamphlet JP 2000-327320 A JP 2001-31414 A

  An object of the present invention is to solve the conventional problems and to achieve the following objects. That is, an object of the present invention is to provide a human body deodorant having a good feeling in use and a high deodorizing effect.

Means for solving the above problems are as follows. That is,
<1> Hydrothermal fine silica hydrogel is subjected to hydrothermal treatment with stirring in a slurry state having a SiO ₂ concentration of 5.0% by mass to 15.0% by mass to obtain a slurry of refined silica hydrogel having an average particle size of 100 μm or less. A step of preparing a refined silica hydrogel slurry including a pulverization step, and introducing zinc oxide fine particles having an average particle size of 0.1 μm to 0.5 μm into the refined silica hydrogel slurry, Characterized by comprising a particulate silica gel containing the zinc oxide fine particles produced by a production method comprising a mixed slurry step for obtaining a mixed slurry with zinc oxide fine particles and a drying step for drying the mixed slurry. It is a deodorant for human body.
<2> The human body deodorant according to <1>, wherein the content of zinc oxide with respect to the total mass of the particulate silica gel is 20% by mass to 70% by mass.
<3> The human body deodorant agent according to any one of <1> to <2>, wherein an average particle diameter of the particulate silica gel is 1 μm to 30 μm.

  ADVANTAGE OF THE INVENTION According to this invention, the said various problems in the past can be solved, the said objective can be achieved, the use feeling is favorable, and the deodorant agent for human bodies with a high deodorizing effect can be provided.

(Deodorant for human body)
The present invention is a human deodorant containing particulate silica gel containing zinc oxide fine particles produced by a method for producing particulate silica gel containing zinc oxide fine particles.

<Method for producing particulate silica gel containing zinc oxide fine particles>
The manufacturing method of the particulate silica gel containing the zinc oxide fine particles includes a preparation process of a fine silica hydrogel slurry, a mixed slurry process, and a drying process, and includes other necessary processes.

-Preparation process of micronized silica hydrogel slurry-
The fine silica hydrogel slurry is prepared by subjecting the silica hydrogel to hydrothermal treatment with stirring in a slurry state having a SiO ₂ concentration of 5.0% by mass to 15.0% by mass to obtain a fine silica hydrogel having an average particle size of 100 μm or less. The hydrothermal pulverization process to make the slurry and other necessary processes are included.
The other necessary steps are not limited and can be appropriately selected according to the purpose. Examples thereof include a wet pulverization step.

The average particle diameter of the silica gel particles in the fine silica gel slurry is preferably 100 μm or less, more preferably 10 μm or less, and most preferably 3 μm or less.
When the average particle diameter exceeds 100 μm, it is difficult to sufficiently enclose the zinc oxide fine particles in the mixed slurry process described later.
On the other hand, when the average particle size of the silica gel particles in the refined silica gel slurry is less than 1 μm, a long mechanical pulverization treatment is required, and there is little influence on the performance improvement of the final human deotorant. For this reason, it is technically and economically meaningless. Moreover, it may be difficult to sufficiently enclose the zinc oxide fine particles.
In the specification, the average particle diameter means a volume average diameter, that is, an MV value (Mean Volume Diameter), and means an average particle diameter weighted by volume.
The method for measuring the particle size is not particularly limited as long as the average particle size defined above can be measured. As an example, a laser diffraction / scattering particle size distribution measuring device (Horiba Ltd., LA-920 type), a Coulter counter (Beckman Coulter, MALTISIZER 3) can be used.

-Hydrothermal pulverization process-
In the hydrothermal pulverization step, silica hydrogel is hydrothermally treated under stirring in a slurry state having a SiO ₂ concentration of 5.0% by mass to 15.0% by mass to obtain a refined silica hydrogel slurry having an average particle size of 100 μm or less; It is a process to do.

As the hydrothermal treatment apparatus, an autoclave that is a high-pressure apparatus with stirring blades is usually used.
If the average particle size of the silica hydrogel charged in the autoclave is 0.1 μm to 5 mm, it can be easily micronized to a particle size of 100 μm or less, more preferably 20 μm or less and 1 μm or more only by hydrothermal treatment with liquid stirring it can.
Further, SiO ₂ concentration of the silica hydrogel in the slurry is preferably 5.0 wt% to 15.0 wt%. When the SiO ₂ concentration exceeds 15.0% by mass, it becomes difficult to sufficiently stir the slurry in the autoclave tank. On the other hand, if the SiO ₂ concentration is less than 5.0% by mass, the amount of water in the resulting silica slurry is large, and the moisture evaporation load in the subsequent drying step is increased, which is not preferable.

  There is no restriction | limiting in particular as pH value in this silica hydrogel slurry, According to the objective, it can select suitably.

  The temperature range of the hydrothermal treatment is 130 ° C to 230 ° C, preferably 150 ° C to 230 ° C. When the temperature is lower than 130 ° C, the effect of refining the particle size of silica hydrogel by hydrothermal treatment is poor, and when it exceeds 230 ° C, the refining of the particle size of silica hydrogel by hydrothermal treatment commensurate with the increase in temperature level. The promotion effect is small and technically and economically meaningless.

  The duration of the hydrothermal pulverization treatment may vary depending on the hydrothermal treatment temperature, but usually 0.2 hr to 24 hr is appropriate. When the hydrothermal treatment time is less than 0.2 hr, a sufficient effect of reducing the particle size by hydrothermal treatment cannot be obtained, and when the hydrothermal treatment time exceeds 24 hr, a particle re-aggregation phenomenon occurs. .

--Wet pulverization process--
The wet pulverization step is a step of mechanically pulverizing the refined silica hydrogel slurry refined in the hydrothermal pulverization step to further refine the slurry.
In order to obtain smaller particles having a target average particle size of 100 μm or less, preferably 10 μm or less, obtained by drying the silica hydrogel slurry, the particle size was reduced to 20 μm or less by hydrothermal pulverization. It is preferable to mechanically wet-grind the silica hydrogel slurry to further refine the average particle size of the silica hydrogel from 1 μm to 3 μm. By such pulverization treatment, a fine spherical silica gel obtained by spray drying or the like can be obtained which has a more nearly spherical shape and a smoother particle surface.

  As the wet pulverizer used here, a bead mill which is a wet medium agitation mill using beads having a particle diameter of 1 mm or less, a wet medium agitation pulverizer using a ball having a particle diameter of several mm, a wet ball mill, or the like is applied.

-Mixing slurry process-
In the mixed slurry forming step, primary particles of zinc oxide fine particles having an average particle size of 0.1 μm to 0.5 μm are introduced into the refined silica hydrogel slurry to obtain a mixed slurry of silica hydrogel fine particles and zinc oxide fine particles. It is a process.

--Zinc oxide fine particles--
The zinc oxide fine particles in the present invention are in the form of primary particles, and the size (particle diameter) of the primary particles is 0.1 μm to 0.5 μm. If it is less than 0.1 μm, it is in an agglomerated state from the beginning when the specific surface area is increased, and cannot be introduced into the silica hydrogel slurry in a sufficiently dispersed state. On the other hand, if it exceeds 0.5 μm, it is relatively unfavorable compared to the particle size of silica gel, and it becomes difficult to enclose the silica gel particles in a well dispersed state.

In order to encapsulate the zinc oxide fine particles, the average particle size is reduced to 0. 0 in the silica hydrogel slurry refined by the hydrothermal pulverization process, or in the silica hydrogel slurry further refined by wet pulverization if necessary. Zinc oxide fine particles of 1 μm to 0.5 μm are added and introduced in an amount of 20 mass% to 70 mass% with respect to ₂ mass of SiO and sufficiently dispersed to obtain a mixed slurry of silica hydrogel fine particles and zinc oxide fine particles. This dispersion is preferably performed in an autoclave or wet pulverizer that performs hydrothermal pulverization as described above.

-Drying process-
The drying step is a step of drying the mixed slurry of the silica hydrogel fine particles and the zinc oxide fine particles.

  A drying apparatus for drying the mixed slurry to obtain finely divided silica gel containing monodispersed fine zinc oxide fine particles. To prevent the particles from aggregating, the particles and droplets are heated without forming a fixed layer. A dispersion type is preferable, and for example, a spray dryer, a medium fluidized bed dryer, a flash dryer and the like are suitable. In particular, spray dryers are suitable.

  In particular, when trying to obtain microspherical silica gel, a spray dryer is suitable as the drying device, and the method of spray atomization of the slurry liquid of the spray dryer is not particularly limited. High-speed rotating disk, one-fluid pressure nozzle, two-fluid nozzle, ultrasonic nozzle, etc. are applied.

  Various conditions such as the slurry supply amount and heating temperature in the case of using a spray dryer are not particularly limited as long as the fine particle silica gel containing zinc fine particles can be produced, and can be appropriately selected according to the purpose.

-Particulate silica gel containing zinc oxide fine particles-
The inclusion rate of zinc oxide in the particulate silica gel containing the zinc oxide fine particles is preferably 20% by mass to 70% by mass and more preferably 30% by mass to 50% by mass with respect to the total mass. preferable.
If the inclusion rate of zinc oxide is less than 20% by mass, the effects of zinc oxide such as deodorizing effect and antibacterial effect cannot be sufficiently achieved. Moreover, when this exceeds 70 mass%, it becomes difficult to enclose zinc oxide particles sufficiently with silica gel, and this comes into contact with the matrix component contained in the human body deodorant agent in which the zinc oxide fine particles should be directly blended. There is a risk of deterioration or decomposition. On the other hand, if it exceeds 70% by mass, an uncomfortable feeling such as rough and rough is produced, and the feeling of use becomes worse.

  The primary particle size (particle size) of the zinc oxide fine particles in the fine particle silica gel containing the zinc oxide fine particles is 0.1 μm to 0.5 μm. That is, the zinc oxide fine particles are maintained in the shape when introduced in the mixed slurrying step, and are encapsulated in fine particle silica gel that encloses the zinc oxide fine particles as primary particles without agglomeration.

  The average particle size of the particulate silica gel enclosing the zinc oxide fine particles is preferably 1 μm to 30 μm, more preferably 5 μm to 25 μm. When using zinc oxide fine particles of 0.1 μm to 0.5 μm, it is difficult to produce an average particle size of fine particle silica gel below 1 μm, and when it exceeds 30 μm, a feeling of discomfort such as rough and rough is generated and used. It feels bad.

  The zinc oxide fine particles encapsulated in the silica gel have a particle size that is minute relative to the particle size of the silica gel particles, and one or more, usually several, preferably a large number of zinc oxide fine particles are dispersed in one silica gel. Is included in the state. The “encapsulation” in the present invention means that the zinc oxide fine particles are contained in the silica gel particles in such a state.

  Probably, in silica gel particles having a large number of pores, in the process of drying the silica gel particles, only the liquid phase of the slurry filling the pores is volatilized and dried. It is presumed that it remains in the state of being supported on the pores. This is considered to be an embodiment in which zinc oxide fine particles are encapsulated in silica gel particles.

<Deodorant for human body>
The human body deodorant agent includes fine particle silica gel containing the zinc oxide fine particles, and other components as necessary.

-Other ingredients-
The other components of the human body deodorant agent are not particularly limited and may be appropriately selected depending on the intended purpose.For example, blending at least one of an antiperspirant component and a bactericidal component is excellent. It is preferable for expressing the odor effect.

  The antiperspirant component is not particularly limited and can be appropriately selected depending on the purpose. For example, chlorohydroxyaluminum, bromohydroxyaluminum, aluminum chloride, aluminum phenolsulfonate, aluminum sulfate, zinc paraphenolsulfonate, Examples thereof include zinc sulfate, aluminum zirconium complex, chlorohydroxyzirconium, chlorohydroxyaluminum zirconium, resinolene zinc, smectite, and tannic acid. Moreover, these 1 type (s) or 2 or more types can be used in combination.

  Moreover, there is no restriction | limiting in particular as said bactericidal component, According to the objective, it can select suitably. For example, benzalkonium chloride, triclosan, isopropylmethylphenol, 3,4,4-trichlorocarbanilide (TC), triethyl citrate (TEC), benzotonium chloride, alkyltrimethylammonium chloride Cetylpyridinium chloride, halocarban, hinokitiol, zinc pyrithione, piroctone olamine, resorcin, phenol, sorbic acid, salicylic acid, hexachlorophene, chlorhexidine gluconate, chlorhexidine hydrochloride, silver supported zeolite, silver supported silica and the like. Moreover, these 1 type (s) or 2 or more types can be used in combination.

  Also, as optional components generally used in human deodorant agents, for example, surfactants, oils, alcohols, thickeners, solvents, propellants, antiseptics, bactericides, antibacterial agents, antioxidants, chelating agents, A pH adjuster, a fragrance, a pigment, a refreshing agent, an anti-inflammatory agent, vitamins, amino acids, water and the like can be appropriately blended according to the purpose.

  Specific examples of the deodorant for human body are not particularly limited and can be appropriately selected depending on the purpose. For example, it can be widely applied as an external preparation for skin, for example, aerosol, liquid Although it can be widely applied as a solid, a powder, etc., it is preferably used in the form of an aerosol from the viewpoint of obtaining a good use feeling.

  There is no restriction | limiting in particular as a propellant component in the case of using it in the said aerosol form, According to the objective, it can select suitably, For example, liquefied petroleum gas, such as a propane and a butane, isopentane, a dimethyl ether etc. are mentioned. The propellant may be used alone or in combination of two or more.

  The content of the propellant is not particularly limited and may be appropriately selected depending on the purpose. It is preferably 50% by mass to 99% by mass, and preferably 70% by mass to the entire antiperspirant deodorant composition. 95 mass% is more preferable. When the content is less than 50% by mass, the undiluted solution adheres to the skin in many cases, and the feeling of use may deteriorate such as dripping on the skin. When the content exceeds 99% by mass, A sufficient effect may not be obtained due to a decrease in the amount of adhesion to the skin. On the other hand, when the content is within the more preferable range, the stock solution adheres to the skin in an appropriate amount, which is advantageous in that the use feeling is superior and a desired effect is easily obtained.

  Such zinc oxide-containing microparticulate silica gel can be suitably used as a human body deodorant agent.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to the following Example.

Example 1
<Manufacturing method 1>
-Hydrothermal pulverization process-
The silica hydrogel was coarsely pulverized to a mean particle size of 1.0 mm using a roll crusher. In a 50 liter autoclave equipped with an anchor type stirring blade, 22,000 g of the coarsely pulverized silica hydrogel and 18,000 g of water were charged, and in a slurry state with a SiO ₂ concentration of 10.0% by mass, at a temperature of 200 ° C. Hydrothermal pulverization was performed for 5 hours at a stirring speed of 90 rpm. The pH of the silica hydrogel slurry was 6.
The silica hydrogel particles in the slurry after the hydrothermal treatment were refined, and the average particle size was 15.0 μm in the particle size measurement by a laser diffraction / scattering type particle size distribution measuring device (LA-920 type, manufactured by Horiba, Ltd.). It was. Further, SiO ₂ concentration in the slurry after the hydrothermal treatment was 10.2 wt%.

-Wet grinding process-
Subsequently, the slurry was further finely pulverized using the wet pulverizer (Dyno-Mill manufactured by Shinmaru Enterprises Co., Ltd., using beads having a diameter of 0.5 mm) while maintaining the concentration. The average particle size of the silica hydrogel particles in the finely pulverized slurry by a Coulter counter (manufactured by Beckman Coulter, MALTISIZER 3, aperture tube diameter 50 μm) was 1.7 μm.

-Mixing slurry process-
To 12,745 g of the silica hydrogel slurry after the wet pulverization, 700 g of zinc oxide (product name: fine zinc oxide, average particle size: 0.3 μm) manufactured by Honjo Chemical Co., Ltd. is added, and the same wet pulverizer as above is used. Hydrogel and zinc oxide were mixed and dispersed. In addition, the average particle diameter of zinc oxide was measured with a laser diffraction / scattering type particle size distribution measuring apparatus (Horiba, Ltd., LA-920 type).

-Drying process-
Using a small spray dryer (GA32 type manufactured by Yamato Scientific Co., Ltd.) with the concentration of the dispersed slurry, the slurry supply amount is 13 mL / min, the spray pressure is 117,680 N / m ² (= 1.2 kg / cm ^2). (G)), spray drying was performed at a hot air temperature of 180 ° C. to obtain fine-particle silica gel containing the zinc oxide fine particles of Example 1. The obtained particle shape was almost spherical and the particle surface was smooth.

(Example 2)
<Manufacturing method 2>
In Example 2, the addition amount of the silica hydrogel slurry after the wet pulverization in the mixed slurry process is changed to 12,745 g to 9,709 g, the addition amount of zinc oxide is changed to 700 g to 1,000 g, and A particulate silica gel containing the zinc oxide fine particles of Example 2 was obtained in the same manner as in Production Method 1 except that the hot air temperature in the drying step was changed to 180 ° C. to 200 ° C.
The particle size of the silica hydrogel particles in the wet pulverization step was measured using a Coulter counter (manufactured by Beckman Coulter, MALTISIZER 3, aperture tube diameter 50 μm used). The average particle diameter of the silica hydrogel particles in the slurry after the wet pulverization was 1.6 μm.

(Example 3)
In Example 3, the particulate silica gel containing the zinc oxide fine particles of Example 3 was used in the same manner as in Example 1 except that the amount of zinc oxide added in the mixed slurrying step was changed to 700 g to 500 g. Obtained.

Example 4
In Example 4, the zinc oxide fine particles of Example 4 are included in the same manner as in Example 2 except that the amount of zinc oxide added in the mixed slurrying step is changed to 1,000 g to 1,400 g. Particulate silica gel was obtained.

(Example 5)
In Example 5, the zinc oxide fine particles of Example 5 are included in the same manner as in Example 2 except that the amount of zinc oxide added in the mixed slurrying step is changed to 1,000 g to 1,600 g. Particulate silica gel was obtained.

(Example 6)
In Example 6, the particulate silica gel containing the zinc oxide fine particles of Example 6 was used in the same manner as in Example 1 except that the amount of zinc oxide added in the mixed slurrying step was changed to 700 g to 200 g. Obtained.

(Example 7)
In Example 7, the zinc oxide fine particles of Example 7 were prepared in the same manner as in Example 2 except that the average particle diameter of zinc oxide added in the mixed slurrying step was changed to 0.3 μm to 0.1 μm. The encapsulated particulate silica gel was obtained.

(Example 8)
In Example 8, the zinc oxide fine particles of Example 8 were encapsulated in the same manner as in Example 2 except that the average particle diameter of zinc oxide added in the mixed slurrying step was changed to 0.3 μm to 0.5 μm. A particulate silica gel was obtained.

Example 9
Example 9 is the same as Example 1 except that the slurry supply rate was 6 mL / min, the spraying pressure was 294,200 N / m ² (= 3.0 kg / cm ² (G)), and the hot air temperature was 150 ° C. in the drying step. Similarly, a particulate silica gel containing the zinc oxide fine particles of Example 9 was obtained.

(Example 10)
In Example 10, the same procedure as in Example 1 was performed except that the slurry supply rate was 13 mL / min and the spray pressure was 78,453 N / m ² (= 0.8 kg / cm ² (G)) in the drying step. A particulate silica gel containing the zinc oxide fine particles of Example 10 was obtained.

(Example 11)
Example 11 was carried out in the same manner as Example 1 except that the slurry supply rate was 13 mL / min and the spray pressure was 58,840 N / m ² (= 0.6 kg / cm ² (G)) in the drying step. A particulate silica gel containing the zinc oxide fine particles of Example 11 was obtained.

Example 12
In Example 12, the same procedure as in Example 1 was performed except that the slurry supply rate was 13 mL / min and the spray pressure was 39,227 N / m ² (= 0.4 kg / cm ² (G)) in the drying step. A particulate silica gel containing the zinc oxide fine particles of Example 12 was obtained.

(Example 13)
In Example 13, the same procedure as in Example 1 was performed except that the slurry supply rate was 13 mL / min and the spray pressure was 19,613 N / m ² (= 0.2 kg / cm ² (G)) in the drying step. A particulate silica gel containing the zinc oxide fine particles of Example 13 was obtained.

(Comparative Example 1)
In Comparative Example 1, it was carried out in the same manner as in Example 2 except that the average particle diameter of zinc oxide was changed to 0.3 μm to 0.01 μm. However, since the zinc oxide particles aggregated in the mixed slurrying step, It was impossible to mix and disperse, and it was impossible to produce a particulate silica gel containing zinc oxide fine particles.

(Comparative Example 2)
In Comparative Example 2, the mixed slurrying step was performed in the same manner as in Example 2 except that the average particle diameter of zinc oxide was changed to 0.3 μm to 2.0 μm, but the zinc oxide particles were too large, It was not possible to produce a particulate silica gel that was not encapsulated in silica gel particles and encapsulated with zinc oxide particles.

(Comparative Example 3)
Only fine particles of fine zinc oxide (trade name, fine zinc white, average particle size 0.3 μm, manufactured by Honjo Chemical Co., Ltd.) were evaluated.

(Comparative Example 4)
In Comparative Example 4, silica gel fine particles (trade name, Sunsphere H-121, average particle size of 12 μm, manufactured by AGC S-Tech Co., Ltd.) were used as the silica gel fine particles of Comparative Example 4, and only the silica gel fine particles were evaluated.

(Comparative Example 5)
<Manufacturing method 3>
In Comparative Example 5, the zinc oxide fine particles of Comparative Example 5 were included based on the following production method 3 described in Patent Document 3 (Japanese Patent Laid-Open No. 09-100112) and Patent Document 4 (Japanese Patent Laid-Open No. 8-12961). A particulate silica gel was obtained.
First, Comparative Example 5 is silica sol (Nissan Chemical Industry Co., Ltd. ST-C, SiO ₂
A concentration of 20.5% by mass) 73 g, zinc oxide ultrafine particles (FINEX 75 manufactured by Sakai Chemical Industry Co., Ltd.) 0.8 g, and water were mixed to make 1 L to obtain a raw material solution.
Next, the dispersion process of the raw material liquid was performed using a high-pressure disperser.
Subsequently, the raw material liquid was sprayed with an ultrasonic nebulizer to form fine droplets having an average diameter of about 5 μm.
Then, this is entrained in a carrier gas (air), dried by passing through a ceramic tube drying tube heated to 500 ° C. by an electric furnace from the outside, and the particulate silica gel containing the zinc oxide fine particles of Comparative Example 5 is obtained. It was.

(Comparative Example 6)
<Manufacturing method 4>
In Comparative Example 6, a particulate silica gel containing the zinc oxide fine particles of Comparative Example 6 was obtained based on Production Method 4 described in Patent Document 5 (Japanese Patent Laid-Open No. 09-40884).
First, 100 g of zinc 2-ethylhexanoate, 50 g of linoleic acid, 5 g of dimethylpolysiloxane and 300 g of xylene as an organic solvent were mixed and stirred to obtain a zinc oxide coating solution.
Next, the solution is refluxed at 180 ° C. to 200 ° C. for 2 hours, cooled to room temperature, and stirred with 3,000 rpm for 1 hour using a homomixer, 15 g of spherical silica (particle size 10.0 μm) is added. Dispersed. Subsequently, the dispersion was distilled for 30 minutes under reduced pressure of 6.7 × 10 ² N / m ^{2 to} 26.7 × 10 ² N / m ² (= 5 mmHg to 20 mmHg), and the solvent was distilled off.
And the obtained viscous liquid was put into the electric furnace, and it baked at 500 degreeC for 2 hours, and obtained the particulate silica gel which included the zinc oxide microparticles | fine-particles of the comparative example 6.

(Comparative Example 7)
<Manufacturing method 5>
In Comparative Example 7, a particulate silica gel containing the zinc oxide fine particles of Comparative Example 7 was obtained based on Production Method 5 described in Patent Document 6 (International Publication No. 02/24153 pamphlet).
First, a zinc oxide powder (primary particle diameter 50 nm to 100 nm) in a mass ratio of Snowtex XL (silica sol manufactured by Nissan Chemical Co., Ltd., silica content 40%, primary particle diameter 40 nm to 60 nm), silica sol: zinc oxide = 25: 75 It was made to disperse | distribute so that it might become a ratio.
Next, 0.1 M dilute hydrochloric acid was dropped into the dispersion, and the gel-like product was dried and pulverized.
The powder was washed with water and dried again to obtain a particulate silica gel containing the zinc oxide fine particles of Comparative Example 7.

<Measurement method of zinc oxide inclusion rate>
Measurement of the chemical composition of the particulate silica gel containing the zinc oxide fine particles in Examples 1 to 13 was performed using the following chelate titration method. Thereby, the inclusion rate of the zinc oxide fine particles in the fine spherical particles was calculated as follows.
Chelate titration method (i) The sample is ignited at 850 ° C. until a constant weight is reached, and then allowed to cool in a desiccator.
(Ii) About 0.4 g of the sample is taken into a 100 mL platinum dish and accurately weighed.
(Iii) Add sulfuric acid and hydrofluoric acid and evaporate to dryness on a burner.
(Iv) After drying, add 10 mL of hydrochloric acid and heat to dissolve.
(V) After cooling, add water to make 250 mL.
(Vi) 10 mL of 20% aqueous ammonium acetate and water are added to 10 mL of this solution to make 100 mL, and then adjusted to pH 5.5 with diluted ammonia water.
(Vii) After pH adjustment, titrate with 0.01 mol / L ethylenediaminetetraacetic acid dihydrogen disodium (EDTA) solution until yellow. (Indicator: Xylenol Orange Reagent)
(Viii) The titration amount and the sampled amount were substituted into the following formula 1, and the zinc oxide inclusion rate was calculated.

<Measurement method of average particle diameter>
Measurement of the average particle diameter of the particulate silica gel containing the zinc oxide fine particles in Examples 1 to 13 was performed using a Coulter counter (manufactured by Beckman Coulter, MALTISIZER 3, aperture tube diameter of 100 μm).

  In addition, about the average particle diameter of the zinc oxide microparticles | fine-particles at the time of using the manufacturing methods 3-5, the zinc oxide inclusion rate, and the average particle diameter of a particulate silica gel differ from the measuring method in the manufacturing methods 1 and 2, and a measurement is abbreviate | omitted. is doing.

<Preparation of formulation>
A formulation of Composition Example 1 described in Table 1 below was prepared as follows and used for evaluating the deodorizing effect and the feeling of use.
First, 5% by mass of any one of the particulate silica gels of Examples 1 to 13 and Comparative Examples 1 to 7 in powder form, 20% by mass of chlorohydroxyaluminum, 5% by mass of anhydrous silicic acid, magnesia silica 5 The mass% was put in a resin container and well shaken and homogenized to obtain a powder mixture.
Next, in the stock solution of Composition Example 1, the remaining composition excluding the composition used for the preparation of the powder mixture was uniformly mixed to form a liquid mixture, and the powder mixture was uniformly mixed with the composition. A stock solution according to Example 1 was obtained.
Next, the stock solution according to Composition Example 1 is put in an aluminum can, and is clinched with an aluminum valve, and then the propellant shown in Table 1 below so that the stock solution / propellant ratio is 7/93 in mass ratio. It mixed with the composition, the propellant of the composition example 1 was filled, and the formulation for evaluation was prepared.

<Evaluation method of deodorization effect (deodorization rate)>
Deodorizing effect by gas chromatograph (GC)
(i) Spray each formulation onto membrane filter for 3 seconds.
(ii) When completely dried, collect the contents remaining on the filter and use it as a sample.
(iii) Take 30 mg of sample into a GC vial (100 mL).
(iv) After dripping 300 μL of 2% isovaleric acid (IVA) aqueous solution into a GC vial, the powder is well dispersed and equilibrated at 40 ° C. for 30 min.
(v) 1 mL of head space was measured by GC, and the deodorization rate was calculated by the following formula from the peak area ratio with the blank of only IVA.
Deodorization rate (%) = 1- (sample peak area / blank peak area) × 100

<Evaluation of use feeling>
The usability when each aerosol type deodorant composition was sprayed for about 2 seconds from a position 15 cm away from the inner side of the forearm was evaluated according to the following evaluation criteria.
The results were shown based on the following criteria from the average value of 10 professional panelists.

〔Evaluation criteria〕
5 points: Very good feeling 4 points: Good feeling 3 points: Somewhat good feeling 2 points: Somewhat bad feeling 1 point: Not good feeling ◎: Average value is 4 or more 5 Below: Average value is 3 or more and less than 4, Δ: Average value is 2 or more and less than 3 ×: Average value is 1 or more and less than 2

The measurement results for the particles according to Examples 1 to 13 and Comparative Examples 1 to 7 are summarized in Table 2 below.

<Prescription example of deodorant for human body>
Table 3 below shows Formulation Examples 1 to 4 of the human body deodorant using silica gel containing the zinc oxide fine particles of the present invention. According to these exemplified formulation examples, a human body deodorant having a good use feeling and a high deodorizing effect can be obtained.

  Since the deodorant for human body of the present invention has a good feeling in use and has a high deodorizing effect, it can be suitably used as a skin external preparation.

Claims (3)

A hydrothermal pulverization step in which the silica hydrogel is hydrothermally treated with stirring in a slurry state having a SiO ₂ concentration of 5.0% by mass to 15.0% by mass to obtain a slurry of refined silica hydrogel having an average particle size of 100 μm or less. A process for preparing a refined silica hydrogel slurry comprising:
A mixed slurrying step of introducing zinc oxide fine particles having an average particle size of 0.1 μm to 0.5 μm into the refined silica hydrogel slurry to obtain a mixed slurry of the silica hydrogel fine particles and the zinc oxide fine particles; ,
A drying step of drying the mixed slurry;
A deodorant for human body, comprising finely divided silica gel encapsulating the zinc oxide fine particles produced by a production method comprising:   The deodorant agent for human bodies according to claim 1, wherein the inclusion rate of zinc oxide with respect to the total mass of the particulate silica gel is 20% by mass to 70% by mass.   3. The human body deodorant according to claim 1, wherein the fine particle silica gel has an average particle size of 1 μm to 30 μm.