JPH05330825A - Iron containing superfine rutile titanium dioxide particle and its production - Google Patents

Abstract

PURPOSE:To provide an iron containing superfine rutile titanium dioxide particles excellent in the shielding ability for zone A of ultraviolet and used appropriately for a sun-screening cosmetic, ultraviolet absorbing coating material or the like. CONSTITUTION:This superfine rutile titanium dioxide has 0.01-0.1mum average single particle diameter and contains 1-15wt.% iron component expressed in terms of Fe per titanium dioxide in the crystal. The superfine rutile titanium dioxide particles are obtained by using a superfine titania sol having rutile nucleus as base particles, precipitation-coating the surface of the titania with the oxide or hydrated oxide of iron, calcining and pulverizing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an iron-containing ultrafine particle titanium dioxide, a method for producing the same, a sunscreen cosmetic using the same, and an ultraviolet protective coating.

[0002]

2. Description of the Related Art Ultrafine particle titanium dioxide having a primary particle size of about 0.1 μm or less is transparent because it transmits visible light when blended with a resin film or a molded product, while it shields ultraviolet light and emits ultraviolet light. It is well known that it exhibits properties different from those of pigment-grade titanium dioxide having a primary particle diameter of 0.15 to 0.5 μm, such as protection of a substance that undergoes discoloration or deterioration. For this reason, the use as a sunscreen cosmetic for keeping the natural skin color and preventing sunburn due to ultraviolet rays has recently been particularly attracting attention. However,
Conventionally commercially available ultrafine particle titanium dioxide has a strong cohesive force, and it is difficult to completely disperse the primary particles in an aqueous or oily medium.For example, a sunscreen cosmetic containing ultrafine particle titanium dioxide should be used. When applied to the skin, it often causes a strong scattering of bluish tints to give a bluish shade, which has the drawback of making the skin appear unhealthy. Further, although conventional ultrafine particle titanium dioxide sufficiently shields light rays having wavelengths in the ultraviolet B region (wavelengths 320 to 290 nm), light rays having wavelengths in the ultraviolet A region (wavelengths 380 to 320 n).
The shielding of m) is insufficient, and in recent years, skin damage due to ultraviolet rays in the A region has become a problem. Therefore, it is the actual situation that an organic ultraviolet absorber or the like is used in combination.

As a sunscreen cosmetic having an excellent ultraviolet shielding effect and not giving a bluish color tone, for example, a cosmetic composition containing fine particles of titanium oxide and fine particles of iron oxide (Japanese Patent Laid-Open No. 62-
No. 67014) has been proposed. However, if the titanium dioxide and the iron oxide are simply blended in this way, color difference may occur in the cosmetics due to the difference in the dispersibility between the two and the shielding of the light rays having the wavelength in the ultraviolet A region may be insufficient. There is such a problem. Recently, in order to prevent the color separation, some methods have been proposed in which titanium dioxide and iron oxide are made into a single pigment. For example, titanium dioxide particles having an average particle diameter of 0.01 to 1 μm are treated with hydrous iron oxide, etc., and dried or fired (Japanese Patent Publication No. 4-50).
No. 01), titanium dioxide having a maximum particle size of 0.1 μm is treated with a basic higher fatty acid iron salt (JP-A-61-264063).
No.), the surface of titanium dioxide particles having a maximum particle size of 0.1 μm or less is treated with an oxide or hydroxide of aluminum, silicon, iron (JP-A-2-204326). However, all of them are methods of using fine particles of titanium dioxide and treating iron hydroxide or oxide on the surface thereof, and then drying or firing. In these cases, so-called blue reduction and shielding of ultraviolet A region are carried out. The effect is not sufficient. Also, Fe ₂ O ₃ / TiO ₂ (weight ratio)
A titanium oxide / iron oxide composite sol (Japanese Unexamined Patent Publication No. 2-178219) having a ratio of 0.05 to 50 has been proposed. This is for the purpose of improving the shielding ability in the ultraviolet A region, which is insufficient with titanium sol, but because it is in the form of a sol, there are restrictions on its blending with cosmetics and paints, and durability and long-term stability. It also leaves a problem.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
It is intended to obtain an iron-containing ultrafine particle rutile-type titanium dioxide that is most suitable for a sunscreen cosmetic or an anti-UV paint that does not give a bluish color tone and has a greatly improved area shielding ability.

[0005]

The inventors of the present invention have found that the ultraviolet rays A
Various studies were carried out in order to obtain ultrafine particle titanium dioxide which has an excellent shielding ability in a region and does not give a blue color tone. as a result,
A microtitania sol having a rutile nucleus is used as a base material, and a water-soluble salt of iron is neutralized in the presence of this to precipitate and coat hydrous iron oxide on the surface of the titania, and then 3
It has been found that rutile titanium dioxide ultrafine particles having an average single particle diameter of 0.01 to 0.1 μm and having an iron component as a solid solution in the crystal thereof can be obtained by firing at 00 to 850 ° C. Is.

The iron-containing ultrafine particle rutile type titanium dioxide thus obtained according to the present invention has an excellent ability to shield in the ultraviolet A region, and has a very small bluish tone even when a cosmetic or the like containing it is applied to the skin. Is. That is, the present invention is rutile type titanium dioxide having an average single particle size of 0.01 to 0.1 μm, and the iron component is contained as Fe in the crystal in an amount of 1 to 15% by weight with respect to TiO _2. It is an ultrafine particle rutile titanium dioxide containing iron.
In the present invention, a fine titania sol having a rutile nucleus is used as a base particle, and the surface is coated with iron oxide hydroxide to be fired. Dissolved in
Even when blended into cosmetics or paints under strong dispersion conditions, the iron component and titanium dioxide do not separate into colors, the shielding ability in the ultraviolet A region is significantly improved, and it is difficult to show a bluish color tone. It produces a remarkably excellent effect. The average particle size of the iron-containing ultrafine particle rutile titanium dioxide of the present invention is 0.01 to 0.1 μm, preferably 0.02 to 0.12, as an average single particle size according to an electron micrograph.
The thickness is 0.08 μm. The amount of the iron component solid-dissolved in the rutile-type titanium dioxide crystals is 1 to 15% by weight, preferably 2 to 10% by weight, based on titanium dioxide, in terms of Fe. If the amount of the iron component is more than the above range, the amount of the iron component that does not form a solid solution in the crystal increases, the coloring due to the iron component becomes too strong, and the heat resistance and chemical resistance of titanium dioxide are impaired. Problems arise. Also, if the amount is less than the above range, sufficient blueness reducing ability and ultraviolet A
It becomes difficult to obtain the area shielding ability and the like.

The iron-containing ultrafine particle rutile type titanium dioxide of the present invention contains a small amount of at least one metal element such as aluminum, zinc, sodium, potassium, magnesium and phosphorus in the crystal thereof, if necessary, in addition to the iron component. May be. This makes it possible to control the particle size and improve the durability of the obtained iron-containing ultrafine particle rutile titanium dioxide. Further, the ultrafine particle titanium dioxide of the present invention has a surface of aluminum, silicon,
Titanium, zircon, tin, at least one kind of oxide or hydroxide of metal such as antimony, or carboxylic acid,
It may be coated with at least one kind of organic substance such as polyol, amine and siloxane. In that case, dispersibility in cosmetics and paints and durability of coating film can be further improved.

Next, a method for producing the iron-containing ultrafine particle rutile type titanium dioxide of the present invention will be described. In the present invention, fine titania sol having a rutile nucleus is used as the base particles, and iron oxide or hydrous oxide is first precipitated on the surface of the titania. The fine titania sol having a rutile nucleus used herein is a sol of fine hydrated titanium oxide showing a peak of rutile type crystal as measured by an X-ray diffraction method, and its average crystallite diameter is usually 50 to 120 Å. .. This is, for example, used as a seed crystal in the hydrolysis of a titanium sulfate solution for the purpose of promoting the rutile conversion of titanium dioxide and controlling the particle size in the production of a titanium dioxide pigment by the sulfuric acid method, and the crystal structure, surface In terms of activity, general titanium hydroxide such as amorphous metatitanic acid,
It is different from orthotitanic acid.

Such fine titania sol is, for example,
Titanium tetrachloride aqueous solution of 150 to 220 g / l as TiO ₂ is heated at the boiling point for 2 to 10 hours to hydrolyze,
While maintaining 150 to 220 g / l titanium sulfate aqueous solution or titanium tetrachloride aqueous solution as iO ₂ at 5 to 30 ° C., it is neutralized with an alkaline solution such as sodium hydroxide to precipitate colloidal amorphous titanium hydroxide. Aging this colloidal titanium hydroxide at 60-80 ° C for 1-10 hours,
Amorphous titanium oxide hydrate such as metatitanic acid or orthotitanic acid is put in an aqueous sodium hydroxide solution,
It is obtained by a method such as heat treatment at a boiling point for 1 to 10 hours, filtration and washing, and then heat treatment in a hydrochloric acid solution at 80 ° C. to a boiling point for 1 to 10 hours.

In the method of the present invention, for precipitating iron oxides and hydrous oxides on the surface of the titania, for example, the fine titania sol is added at 40 to 90 ° C., preferably 60 to 90 ° C.
While heating to 80 ° C., a water-soluble iron salt was added to this so as to be 1 to 15% by weight, preferably 2 to 10% by weight, based on titanium dioxide, and then caustic soda,
It can be carried out by adding an alkaline aqueous solution such as aqueous ammonia to neutralize. The titania sol used may have a titania (TiO ₂ ) concentration of 50 to 30 if necessary.
It is better to adjust to 0 g / l. Water-soluble salts to be added include ferrous chloride, ferrous sulfate, ferrous nitrate, ferric chloride,
Examples thereof include ferric sulfate and ferric nitrate. The neutralization reaction is preferably performed while adjusting the pH of the system to 8-10.

Next, the products obtained in the above steps are fractionated,
After washing, dry with or without drying 300-850
By firing at a temperature of ℃, and crushing, 0.01 ~
The iron-containing ultrafine particles of 0.1 μm rutile titanium dioxide are used. The pulverization can be performed by wet pulverization with a sand mill, pebble mill, disc mill, etc., dry pulverization with a fluid energy mill, hammer mill, edge runner mill, etc.

In the method of the present invention, since the titania sol having rutile nuclei is used as the base particles, the solid solution of the iron component in the titanium dioxide crystal easily progresses and is stable even when calcined at a relatively low temperature. It is possible to easily obtain the rutile-type crystal ultrafine particle titanium dioxide. In the method of the present invention, aluminum, silicon, titanium, zirconium, tin, hydrous oxides of metals such as antimony are precipitated and coated on the surface of the iron-containing ultrafine particle rutile titanium dioxide particles obtained by the method. Good. This method is, for example, calcining, iron-containing rutile titanium dioxide obtained by pulverization is dispersed in water to form a slurry, if necessary wet pulverization, and after classification treatment, aluminum, silicon, titanium, zirconium in it. At least one selected from the group of water-soluble salts of tin, antimony, and tin is 1 to 30% by weight in terms of oxide based on titanium dioxide.
After the addition, if the water-soluble salt is alkaline in the slurry, it is neutralized with an acidic solution such as sulfuric acid or hydrochloric acid, and if the water-soluble salt is acidic in the slurry, it is neutralized with an alkaline solution such as caustic soda or ammonia water. The surface of the titanium dioxide particles can be precipitated and coated, and the particles can be separated, dried and pulverized. By this coating treatment, the dispersibility, durability, etc. of the iron-containing ultrafine particle rutile titanium dioxide in the dispersion medium can be improved.

The iron-containing ultrafine particle rutile-type titanium dioxide of the present invention is useful for various sunscreen cosmetics and UV-preventive coatings as described above, but has recently been attracting attention and is becoming widespread. It is also suitable for

[0014]

【Example】

Example While maintaining an aqueous titanium tetrachloride solution having a concentration of 200 g / l as TiO ₂ at room temperature, an aqueous sodium hydroxide solution was added to adjust the pH to 7.0 to precipitate colloidal amorphous titanium hydroxide oxide. Then, the mixture was aged to obtain rutile type titania sol. After washing this sol well,
₂ was a hydrous titanium oxide aqueous slurry having a concentration of 200 g / l. The slurry was heated to 70 ° C. and stirred well, and the content of Fe was 7 wt% with respect to TiO _2.
Solution of ferrous sulfate (Fe concentration: 50 g / l) is added over 30 minutes, and then sodium hydroxide solution is added over 40 minutes to adjust the pH to 9 to hydrate the surface of the hydrous titanium oxide particles. Iron oxide was precipitated and coated. Then, it was aged for 60 minutes, filtered and washed. The obtained washed cake is 600 ° C.
It was calcined for 3 hours, dispersed in water, and wet-ground with a sand mill to obtain a slurry of ultrafine titanium dioxide. This slurry was heated to 70 ° C., and while stirring well, an aqueous solution of 2.0% by weight aluminum sulfate as Al ₂ O _{3 with} respect to TiO ₂ was added over 30 minutes, and then sodium hydroxide was added. The solution was added and the pH was adjusted to 7.0 to precipitate and coat the hydrated alumina. Then 60
After aging for a minute, filtration, washing and drying, it was pulverized with a fluid energy mill to obtain ultrafine titanium dioxide (A) having an average single particle diameter of 0.04 μm by an electron micrograph.

Comparative Example 1 Ultrafine particle titanium dioxide (B) was obtained in the same manner as in Example 1 except that the ferrous sulfate aqueous solution was not added.

Comparative Example 2 A comparative example except that a 7 wt% ferrous sulfate aqueous solution was added as Fe instead of adding a 2.0 wt% aluminum sulfate aqueous solution as Al ₂ O ₃ for 30 minutes. 1
Ultrafine particle titanium dioxide (C) was obtained in the same manner as in.

Comparative Example 3 Ultrafine particle titanium dioxide (C) of Comparative Example 2 was calcined at 600 ° C. for 3 hours and pulverized by a fluid energy mill to obtain ultrafine particle titanium dioxide (D).

Comparative Example 4 Commercially available ultrafine iron oxide (particle size: about 0.04 μm) was mixed with the ultrafine titanium dioxide (B) of Comparative Example 1 so that Fe was 7% by weight, and a mixed powder ( E) was obtained.

Comparative Example 5 Commercially available iron oxide for pigment (particle size: about 0.2 μm) was used as Comparative Example 1.
The ultrafine titanium dioxide (B) was mixed with Fe so as to be 7% by weight to obtain a mixed powder (F).

[0020]

[Test Example] Ultrafine titanium dioxide (A) to (F) was used as a sunscreen cream with the following formulation. (1) Stearic acid 2.5 parts by weight (2) White beeswax 3.5 parts by weight (3) Cetanol 3.5 parts by weight (4) Squalane 17.0 parts by weight (5) Glycerin monostearate 3.0 parts by weight (6) Ultrafine Titanium Dioxide 3.0 parts by weight (7) Methylparaben 0.1 parts by weight (8) Glycerin 12.0 parts by weight (9) Triethanolamine 1.0 parts by weight (10) Purified water 54.1 parts by weight Parts (11) Fragrance 0.3 parts by weight Add components (1) to (6) heated and mixed at 80 ° C. to components (7) to (10) heated and mixed at 80 ° C., and mix with a homomixer. Mix well and stir vigorously. 45 ° C
A sunscreen cream was prepared by adding (11) in the vicinity.

Evaluation Method 1 Each of the above creams was applied onto a quartz glass so as to have a film thickness of 25 μm, and the transmittance of 750 to 300 nm was measured by a spectrophotometer.

Evaluation method 2 After each of the above creams was used by 10 women aged 20 to 52 years, they were visually evaluated for bluishness. The above evaluation results are shown in Table 1.

[0023]

[Table 1]

[0024]

EFFECTS OF THE INVENTION The iron-containing ultrafine particle rutile titanium dioxide obtained in the present invention has an iron component as a solid solution in the crystal of titanium dioxide. There is no color separation between the components and titanium dioxide,
When applied to sunscreen cosmetics, the ability to block ultraviolet rays in the A region is significantly improved. When applied to cosmetics, even when applied to the skin, it does not cause strong bluish scattering and makes the skin look healthy. , Remarkably excellent effect is exhibited. Further, when applied to a wood coating for preventing ultraviolet rays, it can impart an excellent ultraviolet shielding effect and a preferable color tone.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masakazu Hattori 1 Ishihara-cho, Yokkaichi-shi, Mie Ishihara Industrial Co., Ltd. Yokkaichi Operations

Claims (6)

[Claims] 1. The average single particle diameter is 0.01 to 0.1 μm.
Rutile-type crystal titanium dioxide having an iron content of 1 to 15 relative to the titanium dioxide in terms of Fe in the crystal.
Iron-containing ultrafine particle rutile-type titanium dioxide contained in a weight percentage. 2. Aluminium, silicon,
Titanium, zirconium, having a coating of a hydrous oxide or oxide of at least one element selected from the group of tin and antimony, the coating amount of titanium dioxide particles, the total oxide equivalent of each element is 1 to The iron-containing ultrafine particle rutile titanium dioxide according to claim 1, which is 30% by weight. 3. A water-soluble salt of iron is neutralized in the presence of a fine titania sol having a rutile nucleus, and iron oxide hydroxide on the surface of the titania becomes 1 to 15% by weight based on titanium dioxide in terms of Fe. The method for producing iron-containing ultrafine particle rutile-type titanium dioxide, which comprises the first step of precipitating as described above, the second step of separating the products of the first step, and firing at a temperature of 300 to 850 ° C. 4. An iron-containing ultrafine particle rutile-type titanium dioxide obtained by the method of claim 3 is used as a slurry, and at least one selected from the group of water-soluble salts of aluminum, silicon, titanium, zirconium, tin and antimony. Is added in an amount of 1 to 30% by weight with respect to titanium dioxide in terms of oxide, and then neutralized to coat the surface of the titanium dioxide particle with a hydrous oxide of the element. Production method. 5. A sunscreen cosmetic containing the iron-containing ultrafine particle rutile titanium dioxide according to claim 1. 6. An ultraviolet protective coating material containing the iron-containing ultrafine particle rutile titanium dioxide according to claim 1 or 2.