JPH11322324A - Production of spherical silica containing titanium dioxide, spherical silica containing titanium dioxide and cosmetic - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a spherical silica containing titanium dioxide and having a high UV light-screening effect, good flowability and good dispersibility. SOLUTION: This method for producing spherical silica containing titanium dioxide comprises dispersing titanium dioxide having an average particle diameter of 0.01-0.5 μm in an amount of 10-60 wt.% based on the total amount of SiO2 and the titanium dioxide in an alkali silicate aqueous solution in the alkali silicate aqueous solution, emulsifying the obtained dispersion in an organic solvent containing a surfactant to form an emulsion in which the drops of the dispersion are dispersed in the organic solvent, and subsequently introducing carbon dioxide into the emulsion to gel the liquid drops of the dispersion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing titanium dioxide-containing spherical silica, and titanium dioxide-containing spherical silica, in particular, titanium dioxide-containing spherical silica used for cosmetic raw materials, paint additives, resin additives, and the like. The present invention relates to a cosmetic containing titanium dioxide-containing spherical silica.

[0002]

2. Description of the Related Art Conventionally, titanium dioxide has been used as a pigment.
Alternatively, they are used in cosmetic raw materials, resin additives, paint additives, coating agent components, and the like for the purpose of imparting functions such as ultraviolet shielding properties and photocatalytic action.

In the use of ultraviolet shielding agents, attempts have been made to make particles finer for the purpose of improving transparency in the visible light region. For example, Japanese Patent Application Laid-Open No. Sho 62-198608 discloses that the maximum particle diameter is 0.1 μm or less and the average particle diameter is 10 to 1 μm.
It is disclosed that 00 nm monodispersed titanium dioxide is incorporated into cosmetics.

[0004] However, finely divided titanium dioxide is easily aggregated, and it has been difficult to uniformly disperse and mix it in a resin or the like. Therefore, in order to improve dispersibility,
JP-B-61-49250 proposes a method of depositing hydroxides of silicon and aluminum on the surface of titanium dioxide fine particles. In this method, the fine particles retain the shape of the original titanium dioxide, so that, when compared with the spherical particles, the feel when blended into a cosmetic is not sufficient.

[0005] US Pat. No. 4,090,887 discloses:
A method for producing spherical silica in which a pigment is dispersed by gelling an aqueous silicate solution in which a pigment such as titanium dioxide is dispersed with an acid is disclosed. As for this spherical silica, a silica having a higher ultraviolet shielding effect has been desired.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a powder which has a high ultraviolet shielding effect, has good fluidity and lubricity, and can be easily dispersed and compounded in cosmetics and the like. I do.

[0007]

Means for Solving the Problems The present invention, in an alkaline silicate solution, a titanium dioxide having an average particle diameter of 0.01 to 0.5 [mu] m, the sum of SiO ₂ and titanium dioxide in an alkaline silicate solution The dispersion dispersed at a content of 10 to 60% by weight with respect to the amount was emulsified in an organic solvent containing a surfactant to form an emulsion in which droplets of the dispersion were dispersed in the organic solvent. Thereafter, a method for producing titanium dioxide-containing spherical silica, in which carbon dioxide gas is introduced into the emulsion to gel the droplets of the dispersion, is provided.

In the present invention, a spherical silica gel is obtained because the dispersion of the aqueous alkali silicate solution and titanium dioxide is gelled in the emulsified state. Titanium dioxide gels while maintaining a dispersed state in the aqueous solution,
Disperse in silica gel matrix. In the present invention, since carbon dioxide gas is used for gelation, the mechanism is unknown, but it is considered that titanium dioxide after gelation has high dispersibility. The carbon dioxide gas is considered to have reacted with the alkali silicate once dissolved in the organic solvent.

In the production method of the present invention, the titanium dioxide-containing spherical silica after gelation is further added with 400 to 15 silica gel.
It is preferable to perform the heat treatment at a temperature of 00 ° C. because the effect of shielding ultraviolet rays is significantly increased.

[0010]

DETAILED DESCRIPTION OF THE INVENTION The average particle size of titanium dioxide dispersed in an aqueous alkali silicate solution is 0.01 to 0.5 .mu.m.
m is preferable. If the average particle size exceeds 0.5 μm, the effect of blocking ultraviolet rays is undesirably reduced. Also, when the average particle diameter is smaller than 0.01 μm, the ultraviolet ray shielding effect is reduced and the wavelength region that can be shielded is shifted to the shorter wavelength side, which is not preferable. It is more preferable that the average particle diameter of the titanium dioxide is 0.03 to 0.3 μm.

The content of titanium dioxide in the aqueous alkali silicate solution is preferably from 10 to 60% by weight based on the total amount of SiO ₂ and titanium dioxide in the aqueous alkali silicate solution. If the content of titanium dioxide is less than 10% by weight, the ultraviolet shielding effect is insufficient, which is not preferable. If the content of titanium dioxide is more than 60% by weight, it is difficult to obtain spherical silica, and the transmittance in the visible light region is lowered, which is not preferable for applications such as cosmetics.

In the alkali silicate aqueous solution, the alkali is not particularly limited, but sodium is most preferable for economic reasons. The ratio of silicic acid and alkali is
Assuming that the alkali is sodium, Na ₂ O / SiO
The molar ratio of ₂ is preferably about 2.0 to 3.5. The concentration of the aqueous solution is 5 to 30 wt% as SiO ₂ is preferred.

The titanium dioxide can be dispersed in the aqueous alkali silicate solution by a high-speed shearing disperser, a medium stirring mill, an ultrasonic disperser or the like. In addition, a dispersant can be appropriately used in combination. Particularly in a medium stirring mill, uniform and fine dispersion can be achieved. In this case, the diameter of the beads as a medium is preferably 2 mm or less. The diameter of the beads is 0.
The case of 5 mm or less is particularly preferable.

As the organic solvent, a substance capable of dissolving carbon dioxide is preferable, and the saturated solubility of carbon dioxide at 15 ° C. is preferably 0.05% by weight or more. Examples of the organic solvent used in the present invention include aliphatic hydrocarbons such as hexane and octane; aromatic hydrocarbons such as xylene and toluene; chlorinated hydrocarbons such as chloroform, dichloromethane, trichloroethylene and tetrachloroethylene; Chlorofluorocarbons such as fluoroethane, 2,2-dichloro-1,1,1-trifluoroethane (HCFC-123), 1,1-dichloro-1-fluoroethane (HCFC-141b),
1,3-dichloro-1,1,2,2,3-pentafluoropropane (R225cb), 3,3-dichloro-1,
Hydrochlorofluorocarbons such as 1,1,2,2-pentafluoropropane are preferred.

As the surfactant contained in the organic solvent, polyethylene glycol fatty acid ester, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl ether, sorbitan fatty acid ester, and polyoxyethylene sorbitan fatty acid ester are preferable. The use amount is preferably 0.05 to 10% by weight based on the organic solvent.

A dispersion in which titanium dioxide is dispersed in an aqueous solution of an alkali silicate is added to an organic solvent in which a surfactant is dissolved and emulsified. The dispersion is added to the organic solvent in a volume ratio of 0.1 to 1 so that an emulsion in which the droplets of the dispersion are dispersed in an organic solvent, that is, a W / O emulsion is formed. Is preferred. The emulsification is preferably performed by means such as a turbine type stirrer or a high-speed shearing type emulsifier. In the emulsion, the droplets of the dispersion preferably have an average particle diameter of 0.1 to 100 μm.

When carbon dioxide gas is introduced into the emulsion to gel the droplets of the dispersion, not only 100% carbon dioxide gas may be introduced but also carbon dioxide gas may be diluted with air or the like. The time required for gelation is preferably 0.1 to 30 minutes. The temperature at this time is preferably 5 to 25 ° C.

After the completion of the gelation, the organic solvent is removed, and an appropriate heat treatment or chemical treatment is carried out to obtain an aqueous slurry of titanium dioxide-containing spherical silica (hereinafter referred to as a slurry immediately after synthesis). The slurry immediately after the synthesis mainly contains titanium dioxide-containing spherical silica and alkali carbonate. The titanium dioxide-containing spherical silica is appropriately washed and dried after separation.

According to the production method of the present invention, the silica gel matrix contains 10 to 60% by weight of titanium dioxide having an average particle size of 0.01 to 0.5 μm based on the total amount of SiO ₂ and titanium dioxide. To obtain titanium oxide-containing spherical silica dispersed in the above. The average particle diameter of the titanium oxide-containing spherical silica is preferably 1 to 10 μm.

The titanium dioxide-containing spherical silica thus produced is preferably further heat-treated at a temperature of 400 to 1500 ° C. The heat treatment time is preferably from 0.1 seconds to 10 hours. The heat treatment method is not particularly limited, and for example, a method of heating using an electric furnace, a muffle furnace, a rotary kiln, a tunnel furnace, a multi-stage vertical furnace, or the like is preferable. A more preferred range of the heat treatment temperature is 5
00-1200 ° C.

The titanium dioxide-containing spherical silica of the present invention comprises:
It has high ultraviolet shielding performance and high transparency in the visible light range. By optimizing the production conditions, 2.5 g of the titanium dioxide-containing spherical silica was mixed with 3 g of liquid paraffin and 7 g of white petrolatum, and dispersed using a three-roll mill. When adjusted, the spectral transmittance is 5% or less at 320 nm and 50% or less.
It is possible to obtain titanium dioxide-containing spherical silica that is 35% or more at 0 nm.

The spherical silica containing titanium dioxide can be surface-treated with a silicone oil, a silane coupling agent, a titanate coupling agent, an alcohol, a surfactant, another surface treating agent, or a surface modifying agent. The effects of these surface treatments include an improvement in cosmetic durability when incorporated into cosmetics, an improvement in strength when incorporated into resins, and an increase in dispersion stability. The titanium dioxide-containing spherical silica obtained by the present invention can be suitably used by being blended into cosmetics.

[0023]

EXAMPLE 1 An aqueous sodium silicate solution obtained by diluting 288.4 g of No. 3 silicate (SiO ₂ concentration: 29% by weight) with 87.3 g of pure water was prepared.
45 g of titanium dioxide having an average particle size of 0.26 μm was added,
The mixture was dispersed by stirring with a homomixer for 10 minutes. This dispersion was added to a solution of 3.36 g of sorbitan monooleate as a surfactant in 960 ml of HCFC-123, and emulsified by a homomixer. As a result, a W / O type emulsion was formed, and the average particle diameter of the droplets of the aqueous solution of sodium silicate was about 6 μm.

Carbon dioxide gas (CO ₂ concentration: 10% by volume) diluted with air was blown into the emulsion to gel. After blowing carbon dioxide gas for 15 minutes, HCFC-123 was separated to obtain a slurry composed of spherical silica and water. The slurry was filtered and the cake was washed with demineralized water and dried. The titanium dioxide content of the obtained titanium dioxide-containing spherical silica was 32% by weight, and the average particle size was 5.5 μm.

Example 2 In a sodium silicate aqueous solution obtained by diluting 288.4 g of No. 3 silicate (SiO ₂ concentration: 29% by weight) with 87.3 g of pure water,
70 g of titanium dioxide having an average particle size of 0.04 μm was added,
The dispersion was performed with a residence time of 5 minutes using a medium stirring mill with stabilized zirconia beads having a diameter of 0.3 μm. This dispersion was added to a solution of 3.36 g of sorbitan monooleate as a surfactant in 960 ml of HCFC-123, and emulsified by a homomixer.

Carbon dioxide gas (CO ₂ concentration 10% by volume) diluted with air was blown into the emulsion to gel. After blowing carbon dioxide gas for 15 minutes, HCFC-123 was separated to obtain a slurry composed of spherical silica and water. The slurry was filtered and the cake was washed with demineralized water and dried. The titanium dioxide content of the obtained titanium dioxide-containing spherical silica was 45% by weight, and the average particle size was 2.9 μm.

Example 3 The spherical silica containing titanium dioxide obtained in Example 1 was further heat-treated at 900 ° C. for 30 minutes.

Example 4 The spherical silica containing titanium dioxide obtained in Example 2 was further heat-treated at 700 ° C. for 30 minutes.

(Evaluation of ultraviolet shielding effect) 2.5 g of titanium dioxide-containing spherical silica of Examples 1 to 4 and liquid paraffin 3
g and 7 g of white petrolatum were mixed and dispersed using a three-roll mill. This was sandwiched between quartz plates and the thickness was adjusted to 20 μm, and then the transmittance was measured with an automatic recording spectrophotometer U-4000 manufactured by Hitachi, Ltd. Table 1 shows the transmittance at each wavelength. 50
0 nm is a visible light region, and 320 nm is an ultraviolet light region. 32
The smaller the transmittance at 0 nm, the higher the ultraviolet shielding effect. Each of the titanium dioxide-containing spherical silicas exhibited a high ultraviolet shielding effect. Examples 3 and 4 compared to Examples 1 and 2
Was particularly effective.

[0030]

[Table 1]

Hereinafter, Examples 5 to 10 show formulation examples of cosmetics containing the titanium dioxide-containing spherical silica of the present invention. In each table, the units of the numerical values in the right column are parts by weight.

Example 5 The components (1) to (4) shown in Table 2 were mixed well, and about half of the component (7) and the component (8) were added thereto. 5), (6) and the remainder of the component (7) are heated and melted, added and mixed well, and poured into a container to be cooled and solidified. Thereby, a foundation having an ultraviolet shielding effect and a good feeling of use can be obtained. The dispersion stability after one month is good, and no discoloration or off-flavor is observed.

[0033]

(2) Titanium dioxide-containing spherical silica of Example 4 30.0 (2) Talc 8.0 ( 3) Sericite 8.0 (4) Colored pigment 4.8 (5) Solid paraffin 5.5 (6) Carnauba wax 3.3 (7) Liquid paraffin 37.1 (8) Sorbitan monooleate 3.3 ───────────────────────

Example 6 Powder components (1) to (6) shown in Table 3 were mixed and pulverized and transferred to a Henschel mixer, followed by components (7) to (8)
Is added and mixed so as to be uniform. After sieving to uniform the particle size, the mixture is press-molded in a metal plate. As a result, a pressed powder foundation having a high ultraviolet shielding effect and a good feeling in use can be obtained.

[0035]

[Table 3] ──────────────────────── (1) Talc 32.0 (2) Sericite 30.0 (3) Mica 10.0 (4) Magnesium stearate 1.0 (5) Titanium dioxide-containing spherical silica of Example 4 15.0 (6) Color pigment 2.0 (7) Octyldodecanol 4.0 (8) Silicone oil 6.0 ──────────────────────

Example 7 After the oil phase components (1) to (7) and the aqueous phase components (8) to (13) shown in Table 4 were each dissolved by heating, the aqueous phase component was gradually stirred while the oil phase component was stirred. In addition, further emulsify with a homomixer. As a result, an emulsion having an ultraviolet shielding effect and a good feeling in use can be obtained. In Table 4, PO
E (5) indicates a pentamer adduct of polyoxyethylene.

[0037]

Table 4 ────────────────────────────────── (1) Liquid paraffin 4.7 (2) Lauroyl Dioctyldodecyl glutamate 2.2 (3) Propylene glycol monostearate 0.4 (4) POE (5) hydrogenated castor oil 1.3 (5) POE (5) glyceryl monostearate 2.8 (6) Butyl paraben 0 0.1 (7) Titanium dioxide-containing spherical silica of Example 4 4.0 (8) N-cured tallow fatty acid acyl-L-glutamate sodium 0.3 (9) Carboxyvinyl polymer 0.2 (10) Sodium hydroxide 08 (11) 1,3-butylene glycol 5.0 (12) Methyl paraben 0.2 (13) Purified water 78.72 ─────────── ─

Example 8 The components (1) to (9) shown in Table 5 were dissolved by heating, and the components obtained by stirring and mixing the pigment components (10) to (13) with a high-speed mill were mixed and kneaded with a roll. The mixture is heated again, defoamed and molded. As a result, a lipstick having moderate elongation and smoothness and having an ultraviolet shielding effect can be obtained.

[0039]

[Table 5] ───────────────────────── (1) Carnauba wax 2.0 (2) Candelilla wax 6.5 (3) Beeswax 5 5.5 (4) hydrogenated castor oil 2.0 (5) liquid lanolin 16.8 (6) microcrystalline wax 3.0 (7) octyldodecanol 15.0 (8) octyldodecyl myristate 10.0 (9) Castor oil 23.2 (10) Pearl pigment 2.0 (11) Titanium dioxide-containing spherical silica of Example 4 10.5 (12) Bengala 1.3 (13) Dye (Red No. 202) 2.2 ─────────────────────

Example 9 The spherical silica containing titanium dioxide of Example 4 is subjected to a hydrophobizing treatment with methyl hydrogen polysiloxane. Using this hydrophobized silica, a group consisting of components (1) to (7), a group consisting of (8) to (9), and (10) to
The group consisting of (12) is separately heat-mixed, and the resulting mixture is further mixed. Then, the component (13) is added, the mixture is gradually cooled, and further emulsified by a homomixer. Thereby, a liquid foundation having an ultraviolet shielding effect, excellent in usability, and free from sweat collapse can be obtained.

[0041]

６ (1) Stearic acid 3.0 (2) Isopropyl myristate 9.0 (3 ) Liquid paraffin 1.5 (4) Cetanol 1.0 (5) Butylparaben proper amount (6) Color pigment 2.0 (7) Hydrophobized silica 8.0 (8) Triethanolamine 1.5 (9) Purification Water 25.0 (10) Propylene glycol 5.0 (11) Preservative appropriate amount (12) Purified water 29.0 (13) Bentonite aqueous solution (solid content 1% by weight) 15.0% ──────────────────

Example 10 The components (1) to (11) shown in Table 7 were mixed, and purified water (1
Add 2) and mix further. As a result, a cosmetic having moderate elongation and smoothness and having an ultraviolet shielding effect can be obtained. In Table 7, (7) is a polyoxyalkylene-modified organosiloxane-based surfactant.
The polyoxyethylene chains of (8) and (9) are a pentamer and a 20-mer, respectively, on average.

[0043]

７ (1) Titanium dioxide-containing spherical silica of Example 4 17.0 (2) Bengala 0.03 (3) Yellow iron oxide 0.05 (4) Black iron oxide 0.01 (5) Decamethylcyclopentasiloxane 17.0 (6) Dimethylpolysiloxane 1.0 (7) Toray Dow Corning Silicone SH3775C 5.0 (8) Polyoxyethylene octyldodecyl ether 1.0 (9) Polyoxyethylene sorbitan monostearate 0.5 (10) Shea fat 0.5 (11) Squalane 2.5 ( 12) Purified water 55.41────────────────────────────────

[0044]

Industrial Applicability According to the production method of the present invention, titanium dioxide-containing spherical silica having a suitable dispersion state of titanium dioxide in silica particles and a high ultraviolet shielding effect can be obtained. The titanium dioxide-containing spherical silica of the present invention has a high ultraviolet shielding effect and a high transparency with respect to visible light. Since the silica is spherical in shape, the cosmetic containing the silica has an excellent ultraviolet shielding effect and a good feeling of use such as slipperiness.

Claims (6)

[Claims] 1. An aqueous alkali silicate solution containing titanium dioxide having an average particle diameter of 0.01 to 0.5 μm in an amount of 10 to 60% by weight based on the total amount of SiO ₂ and titanium dioxide in the aqueous alkali silicate solution. % Of the dispersion is emulsified in an organic solvent containing a surfactant to form an emulsion in which droplets of the dispersion are dispersed in the organic solvent.
A method for producing spherical silica containing titanium dioxide, wherein carbon dioxide gas is introduced into the emulsion to gel the droplets of the dispersion. 2. The method for producing titanium dioxide-containing spherical silica according to claim 1, wherein the gelled titanium dioxide-containing spherical silica is further heat-treated at a temperature of 400 to 1500 ° C. 3. The aqueous alkali silicate solution, wherein the alkali is sodium, the molar ratio of Na ₂ O / SiO ₂ is 2.0 to 3.5, and the concentration of the aqueous solution is 5 to 30% by weight as SiO _2. The method for producing titanium dioxide-containing spherical silica according to claim 1 or 2. 4. Titanium dioxide is added to an aqueous solution of an alkali silicate, and titanium dioxide having an average particle diameter of 0.01 to 0.5 μm is dispersed by a medium stirring mill using beads having a diameter of 2 mm or less as a medium. 4. The method for producing spherical silica containing titanium dioxide according to 2 or 3. 5. Average particles in which titanium dioxide having an average particle size of 0.01 to 0.5 μm is dispersed in a silica gel matrix at a content of 10 to 60% by weight based on the total amount of SiO ₂ and titanium dioxide. A titanium dioxide-containing spherical silica having a diameter of 1 to 10 μm, wherein 2.5 g of the titanium dioxide-containing spherical silica is mixed with 3 g of liquid paraffin and white petrolatum 7
g, and dispersed using a three-roll mill, and then containing titanium dioxide having a spectral transmittance of 5% or less at 320 nm and 35% or more at 500 nm when the thickness is adjusted to 20 μm between quartz plates. Spherical silica. 6. A cosmetic comprising the titanium dioxide-containing spherical silica according to claim 5.