JP4201880B2 - Butterfly-like rutile titanium oxide, method for producing the same, and use thereof - Google Patents

Description

【００４８】
この結果より、実施例１、２のバタフライ状ルチル型酸化チタンは、比較例２、３の針状酸化チタンよりＵＶ−Ａ領域での透過率の値が小さく紫外線遮蔽効果に優れていることが分かる。また、比較例１の扇状酸化チタンと比較すると、ＵＶ−Ａ領域での透過率の値はほぼ同等であるが、可視光領域での透過率の値が大きく透明性に優れていることが分かる。
【００４９】
即ち、本実施例のバタフライ状ルチル型酸化チタンは、比較例１〜３のものと比べて、紫外線遮蔽効果及び透明性の両方にバランス良く優れていることが判明した。
【００５０】
【発明の効果】
本発明のバタフライ状ルチル型酸化チタンは、従来の紫外線防御用酸化チタンよりＵＶ−Ａ領域の紫外線防御効果及び透明性の両方に優れており、又、分散性も良好で分散媒体中に容易に一次粒子まで分散するので、紫外線防御を目的とした日焼け止め化粧品、紫外線防止塗料、プラスチックス、ガラス等の紫外線防止剤として有用なものである。
【図面の簡単な説明】
【図１】実施例２で得られた本発明のバタフライ状ルチル型酸化チタンの粒子構造を示す、倍率１００,０００倍の電子顕微鏡写真である。
【図２】比較例１で得られた扇状酸化チタンの粒子構造を示す、倍率１００,０００倍の電子顕微鏡写真である。
【図３】比較例２で得られた針状酸化チタンの粒子構造を示す、倍率１００,０００倍の電子顕微鏡写真である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to titanium oxide having a butterfly-like particle shape. More specifically, the present invention has a high ultraviolet shielding effect and high transparency and dispersibility, thereby preventing ultraviolet rays from being applied to sunscreen cosmetics, ultraviolet protection paints, plastics, and the like. The present invention relates to a butterfly-like rutile type titanium oxide useful as an agent.
[0002]
[Prior art]
Conventionally, in sunscreen cosmetics, UV protection paints, plastics, glass and the like, fine particle titanium oxide powders having a primary particle size of 0.1 μm or less have been widely used as powders that enhance UV protection effects.
[0003]
However, since titanium oxide having a size of 0.1 μm or less is an ultrafine particle, it easily aggregates, and a great deal of labor is required to uniformly disperse to the primary particles. It was impossible. In addition, cosmetics containing titanium oxide of 0.1 μm or less are effective for preventing ultraviolet rays in the UV-B region (280 to 320 nm), but are useful for preventing ultraviolet rays in the UV-A region (320 to 400 nm). This is almost ineffective, so when the amount of the compounding agent is increased for the purpose of preventing ultraviolet rays in the UV-A region, there are problems in terms of use feeling such as roughness and poor spread.
[0004]
As described above, since there are many problems in using titanium oxide of 0.1 μm or less for ultraviolet rays, particularly for UV-A shielding, the length is 0.15 to 0.25 μm for UV-A shielding. Spindle-shaped titanium oxide having a spindle structure with an axial ratio of 3 to 9 or having a particle structure in which spindle-shaped particles having the above-mentioned particle diameters are assembled or bonded has been developed (Japanese Patent Laid-Open Nos. 7-165423 and 9). No. 175821).
[0005]
However, such titanium oxide is highly effective in terms of UV-A shielding, and dispersibility is not a problem. However, since it is spindle-shaped, it is inferior in transparency and used as a UV protection powder. In such a case, there is a drawback that white floats or becomes cloudy. Under such circumstances, there is a strong demand for the appearance of titanium oxide having a high UV-A shielding effect, transparency, and high dispersibility.
[0006]
Under such circumstances, the present inventors previously processed rutile titanium oxide by treating orthotitanic acid obtained by neutralizing titanyl sulfate solution or titanium tetrachloride solution with alkali with hydrochloric acid. When the reaction is carried out under specific conditions, acicular particles are gathered, the sides are 0.05 to 0.2 [mu] m, the thickness direction is 0.02 to 0.1 [mu] m, and the specific surface area is 90 to 180 m < ² > / g. When rutile-type titanium oxide is baked and fan-like titanium oxide is baked, plate-like titanium oxide is obtained. When these particles are dispersed in cosmetics, paints, plastics, etc., they are easily dispersed to primary particles. The cosmetics, paints, plastics, and the like containing these particles have a good transparency and a high prevention effect in the ultraviolet, particularly in the UV-A region, compared to the conventional rutile titanium oxide. ,flat It filed a patent application in 1997 February 28, dated (Japanese Patent Application No. 9-61840).
[0007]
However, in the rutile type titanium oxide having such a shape, there is a complaint that when the particle size is increased in order to further enhance the UV-A shielding effect, the particle size in the thickness direction also increases and the transparency is lowered. .
[0008]
[Problems to be solved by the invention]
Therefore, the object of the present invention is to combine both high UV shielding effect (particularly UV-A shielding effect) and high transparency, and further high dispersibility, so that it can be used for sunscreen cosmetics, UV protection paints, plastics, It is to provide a titanium oxide useful as an ultraviolet ray preventing agent for glass or the like.
[0009]
Means for Solving the Problem and Embodiment of the Invention
As a result of intensive studies to develop a rutile type titanium oxide satisfying both good UV-A shielding properties and transparency properties, the present inventors have determined the temperature and hydrolysis when adding hydrochloric acid to orthotitanic acid. If the titanium oxide concentration and hydrochloric acid concentration in the case of synthesizing titanium oxide are set to specific conditions, the crystallite diameter is 50 to 90 mm, the major diameter is 0.02 to 0.05 μm, and the axial ratio is 4 to 20 ultrafine needle-like particles can be obtained, and the shape of the particles formed by aggregation of the needle-like particles varies depending on the temperature conditions at the time of hydrochloric acid addition. Rutile-type titanium oxide having a particle-like shape is obtained, and in addition, flaky particles are included by observation with a transmission electron microscope. This butterfly-like rutile-type titanium oxide is effective for UV-A shielding. Despite the grain size, the major axis has grown to 0.1 μm or more, the transparency is so good that it has never been considered for spindle-shaped or fan-shaped titanium oxide that has been effective for UV-A shielding. The cosmetics, paints, plastics, glass and the like containing these particles have no white float and cloudiness, and the knowledge that ultraviolet rays, particularly in the UV-A region, have a high prevention effect, has completed the present invention. did.
[0010]
That is, the butterfly-like rutile type titanium oxide of the present invention is obtained by collecting and / or bonding acicular particles having a crystallite diameter of 50 to 90 mm, a major axis diameter of 0.02 to 0.05 μm, and an axial ratio of 4 to 20. A particle structure having a butterfly shape is formed.
[0011]
The crystallite diameter can be measured by X-ray diffraction measurement, and the long axis diameter can be measured by an electron microscope or the like. The above range is preferable because the crystallite diameter, major axis diameter, and axial ratio are less than the above range, because it becomes too fine particles and the surface activity becomes strong, and it is difficult to use as a sunscreen cosmetic or plastic composition. Absent. On the other hand, if the above range is exceeded, the particle structure is not a collection of primary particles, and the needle-like or rod-like single particles conventionally used are not preferable.
[0012]
The butterfly rutile-type titanium oxide of the present invention has a major axis of at least 60% or more of its aggregated particle structure of 0.1 μm or more, particularly 0.12 to 0.2 μm, an axial ratio of 3 to 6, and a thickness direction. It is desirable that the thickness is 0.01 to 0.05 μm, particularly 0.01 to 0.04 μm. The reason for limiting to these numerical ranges is that when the major axis is smaller than the limited range, the shielding effect of ultraviolet rays with high wavelengths is reduced, and when the thickness direction is increased, the transparency is deteriorated. Further, it is desirable that the butterfly-like rutile type titanium oxide of the present invention includes a flaky shape in addition to the particle structure as observed with a transmission electron microscope.
[0013]
In addition, the butterfly rutile titanium oxide of the present invention is a kind of aluminum, silicon, titanium, zirconium, tin, or fluorine on the surface of the particle structure in order to improve dispersion stability and durability in a dispersion medium. It is desirable to coat with a layer containing two or more.
[0014]
The butterfly rutile-type titanium oxide of the present invention is typically prepared by adding hydrochloric acid to orthotitanic acid obtained by neutralizing a titanyl sulfate solution or a titanium tetrachloride solution with an alkali to obtain a TiO ₂ concentration of 80 to 140 g / L. When adjusting to a hydrochloric acid concentration of 90 to 150 g / L, preferably 90 to 140 g / L, preferably after adding hydrochloric acid while maintaining the temperature at 15 to 30 ° C., preferably 25 to 60 ° C. Can be obtained by raising the temperature to 30 to 55 ° C. and conducting the synthesis reaction.
[0015]
The titanyl sulfate or titanium tetrachloride solution preferably contains no iron from the viewpoint of preventing coloring of titanium oxide. The alkali neutralization is preferably performed at a temperature of 30 ° C. or lower.
[0016]
Examples of the alkali include sodium hydroxide, potassium hydroxide, sodium carbonate, ammonium carbonate, sodium fluoride, ammonia, amines and the like. At least one of these can be used, and sodium carbonate is particularly preferable.
[0017]
When the TiO ₂ concentration during the synthesis reaction is less than 80 g / L, the crystallite size and primary particles become large, and a titanium oxide having a particle structure in which primary particles are aggregated cannot be obtained. It is not preferable to have needle-like or rod-like particles having a major axis of 0.1 μm or less.
[0018]
A higher TiO ₂ concentration during the synthesis reaction is preferable, but since fine particulate orthotitanic acid is used, a special device is required when the concentration exceeds 140 g / L, which increases costs. If it exceeds 150 g / L, anatase-type titanium oxide is generated, which is not preferable.
[0019]
When the hydrochloric acid concentration is thinner than 90 g / L, it is not preferable because it becomes needle-like or rod-like particles having a major axis of 0.1 μm or less.
[0020]
If the temperature at which hydrochloric acid is added exceeds 30 ° C., the crystallite diameter becomes larger than 90 mm, and the major axis diameter of each particle exceeds 0.05 μm, which is not preferable because it does not become aggregate particles. On the other hand, when the temperature is less than 15 ° C., fan-shaped particles are obtained, which is not preferable. When the temperature during the synthesis reaction is lower than 25 ° C., the reaction does not proceed, and it takes a long time to complete the reaction. On the other hand, if the temperature exceeds 60 ° C., many agglomerates of particles are generated, which is not preferable.
[0021]
In order to improve dispersion stability and durability in the dispersion medium, the butterfly rutile titanium oxide obtained by the above method has a hydrous oxide of a metal such as aluminum, silicon, titanium, zirconium, tin and fluorine on the particle surface. One or more oxides can be coated, but the metal salt used for this is not limited in any way. Further, after the metal hydrated oxide or oxide is coated, a coating treatment with an organic substance, for example, silicon oil, various coupling agents, or a fatty acid compound, can further improve dispersibility.
[0022]
The butterfly rutile type titanium oxide of the present invention is useful for various sunscreen cosmetics, UV protection paints, UV protection plastic compositions, UV protection glasses and the like.
[0023]
When the butterfly rutile titanium oxide of the present invention is used as a sunscreen cosmetic, for example, in a cosmetic cream, oils and fats such as fats and waxes, surfactants, alcohols, humectants, pigments, purified water Perfumes can be added to antiseptics, thickeners, etc. as necessary, and they can be used in creams, emulsions, paste lotions, and the like.
[0024]
When the butterfly rutile titanium oxide of the present invention is used as an anti-ultraviolet paint, for example, polyvinyl alcohol resin, vinyl chloride-vinyl acetate resin, acrylic resin, epoxy resin, urethane resin, alkyd resin, polyester resin, ethylene vinyl acetate copolymer It is blended in a coalescence, a fiber resin, a phenol resin, an amino resin, etc. and dispersed in water or a solvent. In skin-colored sunscreen cosmetics, in order to suppress color separation, color unevenness, white floatation, and bluishness, etc., the particles are coated with hydrous iron oxide and then baked to solidify inside the titanium dioxide crystals. Although dissolved iron-containing titanium oxide is used, the butterfly-like rutile titanium oxide of the present invention is also suitable as this raw material.
[0025]
When the butterfly-like rutile type titanium oxide of the present invention is used as an ultraviolet ray preventing plastic composition, for example, vinyl chloride resin, ABS resin, polyethylene, polypropylene, vinylidene chloride, polystyrene, polycarbonate, nylon, EVA resin, polyacetal resin, polyamide It is blended in a synthetic resin such as resin, phenol resin, melamine resin, acrylic resin, polyester resin, urea resin, silicone resin, or fluorine resin.
[0026]
When the butterfly-like rutile titanium oxide of the present invention is used as an anti-ultraviolet glass, for example, silicate glass such as alkali silicate glass, soda lime glass, potash lime glass, lead glass, barium glass, borosilicate glass, phosphoric acid, etc. It is made to contain in salt glass, borate glass, etc.
[0027]
Hereinafter, the present invention will be described in more detail with reference to examples. The following examples are given for illustrative purposes only and are not intended to limit the scope of the invention.
[0028]
【Example】
Example 1
A titanium tetrachloride solution was slowly added dropwise to a 160 g / L sodium carbonate solution so that the liquid temperature did not exceed 25 ° C., and when the pH reached 10, the addition of titanium tetrachloride was stopped.
[0029]
The white precipitate of orthotitanic acid obtained by this neutralization was filtered and thoroughly washed. The washed orthotitanate cake was repulped with dilute hydrochloric acid while maintaining the temperature at 30 ° C., and further concentrated hydrochloric acid was added to adjust the TiO ₂ concentration to 90 g / L and the hydrochloric acid concentration to 107 g / L.
[0030]
Next, the mixture was heated with stirring, the liquid temperature was adjusted to 50 ° C., and the mixture was allowed to stand for 1 day while maintaining 50 ° C. to synthesize rutile titanium oxide.
[0031]
Next, sodium aluminate as Al ₂ O ₃ was slowly added to the obtained rutile-type titanium oxide-containing water suspension while stirring at 6%, and the mixture was stirred for 1 hour to treat Al ₂ O ₃ . Thereafter, 400 g / L sodium hydroxide was added to adjust the pH to 6.5, followed by filtration, washing and drying to obtain alumina-coated rutile titanium oxide.
[0032]
The rutile-type titanium oxide obtained at this time had a crystallite diameter of 78 mm, a major axis of 0.09 to 0.18 μm, and 80% or more of the grains had a major axis of 0.1 μm or more. The minor axis was a mixture of flake-like and butterfly-like particles having a minor diameter of 0.02 to 0.05 μm and a specific surface area of 143 m ² / g.
[0033]
Example 2
A titanyl sulfate solution obtained by digesting metatitanic acid obtained by hydrolysis with a sulfuric acid method into a 160 g / L sodium carbonate solution with hot concentrated sulfuric acid is slowly added dropwise so that the liquid temperature does not exceed 25 ° C., and the pH is 10 At that time, the titanyl sulfate dripping was stopped.
[0034]
The white precipitate of orthotitanic acid obtained by this neutralization was filtered and thoroughly washed. The washed orthotitanate cake was repulped with dilute hydrochloric acid while maintaining the temperature at 20 ° C., and then concentrated hydrochloric acid was added to adjust the TiO ₂ concentration to 100 g / L and the hydrochloric acid concentration to 120 g / L.
[0035]
Next, the mixture was heated with stirring, the liquid temperature was adjusted to 40 ° C., and the mixture was allowed to stand for 24 hours while maintaining 40 ° C. to synthesize rutile titanium oxide.
[0036]
Then, the resulting rutile-type titanium oxide water suspension containing sodium silicate was added 8% as SiO _2, was carried out with stirring neutralized SiO ₂ processing until pH 7 with hydrochloric acid 200 g / L . Next, after adding 10% of aluminum sulfate as Al ₂ O ₃ , the pH was neutralized to 7 with 400 g / L sodium hydroxide while stirring, and further stirred for 1 hour to treat Al ₂ O ₃ . went. Thereafter, filtration, washing and drying were performed to obtain silica and alumina-coated rutile titanium oxide.
[0037]
An electron micrograph of the rutile-type titanium oxide obtained at this time is shown in FIG. This rutile type titanium oxide has a crystallite diameter of 64 mm, a major axis of 0.08 to 0.18 μm, 90% or more of the particles are 0.1 μm or more, a minor axis of 0.02 to 0.04 μm, a specific surface area of 168 m ² / g, the majority of the particle shape was butterfly-like, and the number of flaky particles was small.
[0038]
Comparative Example 1
The synthesis reaction of rutile titanium oxide and the treatment of aluminum were performed in the same manner as in Example 1 except that the temperature when adding hydrochloric acid to orthotitanic acid in Example 1 was maintained at 13 ° C.
[0039]
The titanium oxide obtained at this time was a fan-shaped titanium oxide having a crystallite diameter of 65 mm and a specific surface area of 140 m ² / g , as shown in FIG.
[0040]
Comparative Example 2
A synthesis reaction of rutile titanium oxide and silica and aluminum treatment were performed in the same manner as in Example 2 except that the temperature at which hydrochloric acid was added to orthotitanic acid in Example 2 was maintained at 40 ° C.
[0041]
The rutile type titanium oxide obtained at this time had a crystallite diameter of 110 mm, and as shown in FIG. 3, the major axis was 0.03 to 0.08 μm, the minor axis was 0.01 to 0.02 μm, and the specific surface area was 143 m ² / g. It was acicular titanium oxide.
[0042]
Comparative Example 3
A silica and alumina-coated rutile titanium oxide were obtained in the same manner as in Example 2 except that the hydrochloric acid concentration was changed to 60 g / L in Example 2 and the synthesis reaction was performed at the boiling point.
[0043]
The rutile type titanium oxide obtained at this time was acicular titanium oxide having a crystallite diameter of 130 mm, a major axis of 0.04 to 0.10 μm, a minor axis of 0.01 to 0.02 μm, and a specific surface area of 134 m ² / g.
[0044]
Test Examples Example 1, Example 2, Comparative Example 1, Comparative Example 2 and Comparative Example 3 0.42 g each of rutile type titanium oxide, acrylic resin (Acridic 47-712, manufactured by Dainippon Ink & Chemicals, Inc.) 7.2 g, 1.5 g of melamine resin (Super Becamine L-117, manufactured by Dainippon Ink and Chemicals), 10.5 g of thinner (toluene / butyl acetate / S-100 = 3/5/2), 0.8 mm zircon A mill base was prepared by placing 100 g of beads in a 150 ml stoppered glass bottle and dispersing for 60 minutes in a paint conditioner.
[0045]
An acrylic resin (14.4 g) and a melamine resin (3.0 g) were added to each mill base, mixed with a paint conditioner for 10 minutes, and then applied onto quartz glass with a 2 mil doctor blade.
[0046]
The coated film was baked at 120 ° C. for 10 minutes, and then transmitted light of 300 to 800 nm was measured with a spectrophotometer.
The measurement results are shown in Table 1.
[0047]
[Table 1]

[0048]
From this result, it can be seen that the butterfly rutile titanium oxide of Examples 1 and 2 has a smaller transmittance value in the UV-A region than the acicular titanium oxides of Comparative Examples 2 and 3, and has an excellent ultraviolet shielding effect. I understand. Moreover, compared with the fan-shaped titanium oxide of Comparative Example 1, it can be seen that the transmittance value in the UV-A region is almost the same, but the transmittance value in the visible light region is large and excellent in transparency. .
[0049]
That is, it was found that the butterfly-like rutile type titanium oxide of this example was excellent in both the ultraviolet shielding effect and the transparency in comparison with those of Comparative Examples 1 to 3.
[0050]
【The invention's effect】
The butterfly-like rutile-type titanium oxide of the present invention is superior in both UV protection effect and transparency in the UV-A region than conventional UV protection titanium oxide, and also has good dispersibility and is easily dispersed in a dispersion medium. Since it is dispersed up to the primary particles, it is useful as a UV protection agent for sunscreen cosmetics, UV protection paints, plastics, glass and the like for UV protection.
[Brief description of the drawings]
1 is an electron micrograph at a magnification of 100,000 times showing the particle structure of butterfly-like rutile titanium oxide of the present invention obtained in Example 2. FIG.
2 is an electron micrograph of a magnification of 100,000 times showing the particle structure of fan-shaped titanium oxide obtained in Comparative Example 1. FIG.
3 is an electron micrograph of a magnification of 100,000 times showing the particle structure of acicular titanium oxide obtained in Comparative Example 2. FIG.

Claims (8)

By forming and / or combining acicular particles having a crystallite diameter of 50 to 90 mm, a major axis diameter of 0.02 to 0.05 μm, and an axial ratio of 4 to 20 to form a butterfly shape, A butterfly-like rutile-type titanium oxide. At least 60% or more of the particle structure has a major axis of 0.1 μm or more, an axial ratio of 3 to 6, and a thickness of 0.01 to 0.05 μm. In addition to the particle structure, a transmission electron microscope is used. The butterfly-like rutile type titanium oxide according to claim 1, wherein a piece of flake is observed. The butterfly rutile oxidation according to claim 1 or 2, wherein the surface of the particle structure is coated with a layer containing one or more of aluminum, silicon, titanium, zirconium, tin and fluorine. titanium. When adjusting the TiO ₂ concentration to 80 to 140 g / L and the hydrochloric acid concentration to 90 to 150 g / L by adding hydrochloric acid to orthotitanic acid obtained by alkali neutralization of a titanyl sulfate solution or titanium tetrachloride solution at room temperature, the temperature after addition of hydrochloric acid while maintaining to 15 to 30 ° C., characterized by synthesized by heating to 25 to 60 ° C., a manufacturing method of a butterfly-shaped rutile-type titanium oxide according to claim 1 or 2, wherein. A sunscreen cosmetic comprising the butterfly-like rutile-type titanium oxide according to any one of claims 1 to 3. An anti-ultraviolet paint comprising the butterfly-like rutile-type titanium oxide according to any one of claims 1 to 3. An anti-ultraviolet plastic composition comprising the butterfly-like rutile-type titanium oxide according to any one of claims 1 to 3. An anti-ultraviolet glass comprising the butterfly rutile-type titanium oxide according to any one of claims 1 to 3.

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