JP2717904B2 - Iron-containing ultrafine rutile titanium dioxide and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Ultrafine titanium dioxide having a primary particle size of about 0.1 .mu.m or less, when incorporated into a resin film or molded product, transmits visible light so that it exhibits transparency. It is well known that it exhibits properties different from those of pigment-grade titanium dioxide having a primary particle size of 0.15 to 0.5 μm, for example, to protect substances that undergo discoloration or alteration due to the following conditions. For this reason, utilization as a sunscreen cosmetic for making use of natural skin color and preventing sunburn due to ultraviolet rays has recently attracted particular attention. However,
Conventionally, commercially available ultrafine 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 titanium dioxide is used. When applied to the skin, it often has the disadvantage of causing strong scattering of bluish shades, giving bluish tones and, thus, making the skin look unhealthy. Further, the conventional ultrafine titanium dioxide sufficiently shields the light beam having the wavelength in the ultraviolet B region (wavelength 320 to 290 nm), but the light beam having the wavelength in the ultraviolet A region (wavelength 380 to 320 n).
m) is insufficiently shielded, and in recent years, skin damage due to ultraviolet rays in the A region has become a problem. For this reason, it is a fact that organic ultraviolet absorbers and the like are used in combination.

As a sunscreen cosmetic which has an excellent ultraviolet shielding effect and does not impart a bluish color, for example, a cosmetic composition comprising fine particle titanium oxide and fine particle iron oxide (Japanese Patent Laid-Open No. Sho 62-62).
No. 67014) has been proposed. However, simply blending titanium dioxide and iron oxide in this manner causes color separation in the cosmetic due to the difference in dispersibility between the two, and insufficient shielding of light having a wavelength in the ultraviolet A region. There are problems. Recently, several methods have been proposed to make titanium dioxide and iron oxide into a single pigment in order to prevent the color separation. For example, titanium dioxide particles having an average particle diameter of 0.01 to 1 μm are treated with iron oxide hydroxide or the like, and dried or fired (Japanese Patent Publication No. 4-50).
No. 01), a basic higher fatty acid iron salt is applied to titanium dioxide having a maximum particle size of 0.1 μm (JP-A-61-26463).
No. 2), 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 or iron (Japanese Patent Application Laid-Open No. 2-204326). However, all of these methods use titanium dioxide fine particles, treat a hydroxide or oxide of iron on the surface thereof, and dry or sinter them. The effect is not enough. Fe ₂ O ₃ / TiO ₂ (weight ratio)
Of titanium oxide / iron oxide (Japanese Patent Laid-Open No. 178219/1990). This is intended to improve the shielding ability in the ultraviolet A region, which is insufficient with titanium sol, but because it is in the form of a sol, its formulation into cosmetics and paints is limited, and durability and long-term stability There is still a problem in terms of.

[0004]

SUMMARY OF THE INVENTION The present invention relates to an ultraviolet light
It is an object of the present invention to obtain iron-containing ultrafine rutile-type titanium dioxide which is greatly improved in the shielding ability of an area and which does not give a bluish color and which is most suitable for sunscreen cosmetics or anti-ultraviolet paints.

[0005]

Means for Solving the Problems The inventors of the present invention have developed an ultraviolet A
Various investigations were conducted to obtain ultrafine titanium dioxide which has an excellent region shielding ability and does not give a bluish color tone. as a result,
A fine titania sol having a rutile nucleus is used as a base material, and a water-soluble salt of iron is neutralized in the presence of the sol to precipitate and coat the surface of the titania with hydrous iron oxide.
By firing at 00 to 850 ° C, it has been found that rutile-type titanium dioxide ultrafine particles having an average single particle diameter of 0.01 to 0.1 µm and a solid solution of an iron component in the crystal can be obtained. It is.

The iron-containing ultrafine rutile type titanium dioxide of the present invention thus obtained has an excellent ultraviolet ray A shielding ability and has a very low bluish color tone even when a cosmetic or the like containing the same is applied to the skin. It is. That is, the present invention is a rutile-type crystal titanium dioxide having an average single particle diameter of 0.01 to 0.1 μm, and contains 1 to 15% by weight of iron component as Fe with respect to TiO ₂ inside the crystal. Is an iron-containing ultrafine rutile type titanium dioxide.
In the present invention, a fine titania sol having a rutile nucleus is used as a base particle, and the surface thereof is coated with hydrated iron oxide. Then, the calcination is performed. Dissolved in
Even when blended in cosmetics or paints under strong dispersion conditions, the color separation of the iron component and titanium dioxide does not occur, the ability to block the ultraviolet A region is remarkably improved, and it is difficult to show a bluish color. It exhibits a remarkably excellent effect that cannot be obtained. The average particle size of the iron-containing ultrafine rutile type titanium dioxide of the present invention is 0.01 to 0.1 μm, preferably 0.02 to
0.08 μm. The amount of the iron component dissolved in the rutile-type titanium dioxide crystal 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 inside the crystal increases, and the coloring due to the iron content becomes too strong, and the heat resistance and chemical resistance of titanium dioxide are impaired. Problem arises. On the other hand, if it is less than the above range, sufficient blueness reduction ability and ultraviolet A
It becomes difficult to obtain an area shielding ability and the like.

[0007] The iron-containing ultrafine-particle rutile-type titanium dioxide of the present invention contains a small amount of at least one of metal elements such as aluminum, zinc, sodium, potassium, magnesium, and phosphorus in the crystal together with the iron component, if necessary. May be. This makes it possible to control the particle size of the resulting iron-containing ultrafine rutile titanium dioxide particles and to improve the durability. Further, the ultrafine titanium dioxide of the present invention, the surface thereof is aluminum, silicon,
Titanium, zircon, tin, at least one oxide or hydroxide of a metal such as antimony, or a carboxylic acid,
It may be coated with at least one of organic substances such as polyols, amines and siloxanes. In this case, dispersibility in cosmetics and paints and durability of coating films can be further improved.

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

Such a fine titania sol is, for example,
Hydrolyzed titanium tetrachloride aqueous solution 150~220g / l as TiO ₂ is heated at the boiling point 2 to 10 hours, T
While maintaining a 150 to 220 g / l aqueous solution of titanium sulfate or an aqueous solution of titanium tetrachloride as iO ₂ at 5 to 30 ° C., neutralize 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 such as metatitanic acid or orthotitanic acid is placed in an aqueous sodium hydroxide solution at 80 ° C.
After heating at a boiling point for 1 to 10 hours, filtration and washing are carried out, and then heat treatment is performed in a hydrochloric acid solution at 80 ° C. to a boiling point for 1 to 10 hours.

In the method of the present invention, in order to precipitate an oxide of iron and a hydrated oxide on the surface of the titania, for example, the fine titania sol is heated at 40 to 90 ° C., preferably 60 to 90 ° C.
While heating to 80 ° C., a water-soluble iron salt is added thereto in an amount of 1 to 15% by weight, preferably 2 to 10% by weight, based on titanium dioxide, in terms of Fe.
It can be carried out by adding an alkaline aqueous solution such as aqueous ammonia to neutralize the solution. The titania sol used may have a titania (TiO ₂ ) concentration of 50 to 30 if necessary.
It is good to adjust to 0 g / l. Ferrous chloride, ferrous sulfate, ferrous nitrate, ferric chloride,
Ferric sulfate, ferric nitrate and the like can be mentioned. The neutralization reaction is preferably performed while adjusting the pH of the system to 8 to 10.

Next, the product obtained in the above step is fractionated,
After washing, dry or 300-850 without drying
By sintering and crushing at a temperature of
0.1 μm iron-containing ultrafine particles of rutile-type titanium dioxide. The pulverization can be performed by wet pulverization with a sand mill, pebble mill, disk mill, or the like, or dry pulverization with a fluid energy mill, hammer mill, edge runner mill, or the like.

In the method of the present invention, since the titania sol having rutile nuclei is used as the base particles, the iron component easily dissolves in the titanium dioxide crystal even when calcined at a relatively low temperature, and is stable. It is possible to easily obtain the rutile-type crystal ultrafine titanium dioxide. In the method of the present invention, aluminum, silicon, titanium, zirconium, tin, and a metal hydrate such as antimony are precipitated on the surface of the iron-containing ultrafine rutile type titanium dioxide particles obtained by the above method, and may be coated. Good. This method, for example, calcined, pulverized iron-containing rutile-type titanium dioxide obtained by dispersing in water to form a slurry, wet pulverization, if necessary, classification, and then aluminum, silicon, titanium, zirconium , At least one selected from the group of water-soluble salts of tin and antimony 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, neutralize it with an acidic solution such as sulfuric acid or hydrochloric acid.If the water-soluble salt shows an acidity in the slurry, neutralize it with an alkaline solution such as sodium hydroxide or aqueous ammonia. Then, the surface of the titanium dioxide particles is precipitated and coated, separated, dried, and pulverized. By this coating treatment, the dispersibility, durability and the like of the iron-containing ultrafine particle rutile-type titanium dioxide dispersion medium can be improved.

Although the iron-containing ultrafine rutile type titanium dioxide of the present invention is useful for various sunscreen cosmetics and ultraviolet ray preventing paints as described above, it has recently attracted attention and is becoming popular. It is also suitable.

[0014]

【Example】

EXAMPLE While maintaining a 200 g / l aqueous solution of titanium tetrachloride as TiO ₂ at room temperature, an aqueous solution of sodium hydroxide was added to adjust the pH to 7.0 to precipitate colloidal amorphous hydrous titanium oxide. The mixture was then aged to obtain a rutile-type titania sol. After thoroughly washing this sol, TiO
₂ was used as a hydrous titanium oxide aqueous slurry having a concentration of 200 g / l. This slurry was heated to 70 ° C., and with good stirring, 7% by weight of Fe relative to TiO ₂ was contained therein.
Ferrous sulfate aqueous solution (Fe concentration 50 g / l) was added over a period of 30 minutes, and a sodium hydroxide solution was added over a period of 40 minutes to adjust the pH to 9 and water was added to the surface of the hydrous titanium oxide particles. The iron oxide was precipitated and coated. After aging for 60 minutes, the mixture was filtered and washed. 600 ° C of the obtained washed cake
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 aluminum sulfate of 2.0% by weight as Al ₂ O _{3 with} respect to TiO ₂ was added thereto over 30 minutes. The solution was added, the pH was adjusted to 7.0, and the hydrated alumina was precipitated and coated. Then 60
After aging for minutes, filtration, washing, drying, and pulverization with a fluid energy mill, ultrafine titanium dioxide (A) having an average single particle diameter of 0.04 μm as determined by electron micrograph was obtained.

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

Comparative Example 2 Comparative Example 2 was repeated except that a 2.0% by weight aqueous solution of aluminum sulfate was added as Al ₂ O ₃ in 30 minutes, instead of adding a 7% by weight aqueous solution of ferrous sulfate as Fe. 1
In the same manner as in the above, ultrafine titanium dioxide (C) was obtained.

Comparative Example 3 The ultrafine 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 titanium dioxide (D).

COMPARATIVE EXAMPLE 4 A commercially available ultrafine iron oxide (particle diameter: about 0.04 μm) was mixed with the ultrafine titanium dioxide (B) of Comparative Example 1 so as to be 7% by weight as Fe and mixed powder ( E) was obtained.

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

[0020]

Test Example Ultrafine titanium dioxide (A) to (F) were used as sunscreen creams according to the following formulations. (1) 2.5 parts by weight of stearic acid (2) 3.5 parts by weight of beeswax (3) 3.5 parts by weight of cetanol (4) 17.0 parts by weight of squalane (5) 3.0 parts by weight of glycerin monostearate (6) Ultrafine titanium dioxide 3.0 parts by weight (7) Methyl paraben 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 Part (11) Perfume 0.3 parts by weight A mixture obtained by heating and mixing components (1) to (6) at 80 ° C. is added to a mixture obtained by heating and mixing components (7) to (10) at 80 ° C. Mix well and stir vigorously. 45 ° C
In the vicinity, (11) was added to prepare a sunscreen cream.

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

Evaluation method 2 After each of the above creams was normally used by 10 women aged 20 to 52 years, the creams were visually evaluated with respect to each other. Table 1 shows the above evaluation results.

[0023]

[Table 1]

[0024]

The iron-containing ultrafine rutile type titanium dioxide obtained by the present invention has an iron component dissolved in the titanium dioxide crystal. No color separation of components and titanium dioxide,
When applied to sunscreen cosmetics, the ability to block the ultraviolet 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. , Exhibit a remarkably excellent effect. In addition, when applied to a wood coating for preventing ultraviolet rays, an excellent ultraviolet shielding effect and a favorable color tone can be imparted.

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Claims (6)

(57) [Claims] An average single particle diameter of 0.01 to 0.1 μm
Is a rutile-type crystal titanium dioxide having an iron component in the crystal in terms of Fe, which is 1 to 15 with respect to the titanium dioxide.
Iron-containing ultrafine rutile-type titanium dioxide contained in a proportion of% by weight. 2. The particle surface has aluminum, silicon,
Titanium, zirconium, tin and has a coating of a hydrated oxide or oxide of at least one element selected from the group of antimony, the coating amount is 1 to the titanium dioxide particles, in terms of the total oxide equivalent of each element. The iron-containing ultrafine rutile type 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 the surface of the titania contains 1 to 15% by weight, based on Fe dioxide, of iron oxide hydrochloride with respect to titanium dioxide. A method for producing ultrafine iron-containing rutile titanium dioxide comprising a second step of separating the product of the first step and the first step of precipitating as described above and baking at a temperature of 300 to 850 ° C. 4. A slurry of the iron-containing ultrafine rutile type titanium dioxide obtained by the method of claim 3, wherein the slurry is at least one selected from the group consisting of water-soluble salts of aluminum, silicon, titanium, zirconium, tin and antimony. Of iron-containing ultrafine rutile type titanium dioxide, which is obtained by adding 1 to 30% by weight of titanium oxide in terms of oxide total amount and then neutralizing and coating the surface of the titanium dioxide particles with a hydrated oxide of the element. Production method. 5. A sunscreen cosmetic comprising the iron-containing ultrafine rutile type titanium dioxide of claim 1 or 2. 6. An anti-ultraviolet coating comprising the iron-containing ultrafine rutile type titanium dioxide of claim 1 or 2.