JP2878415B2 - Rutile-type particulate titanium dioxide composition having high weather resistance and high light tarnish resistance and method for producing the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a rutile-type particulate titanium dioxide composition having high weather resistance and high photochromic resistance and a method for producing the same.

[Conventional technology]

Fine particle titanium dioxide having a maximum particle diameter of less than 0.1 μm is
The average particle size is 0.1, such as having transparency or UV absorption.
It has characteristics different from titanium dioxide of μm or more (so-called pigment grade titanium dioxide),
It is used in a wide range of fields such as paints, cosmetics, and compositions for resins.

By the way, the fine particle titanium dioxide is an anatase type and a rutile type crystal structure and a mixture thereof and an amorphous material.In particular, in paints and cosmetics which are required to have weather resistance and light discoloration resistance, these characteristics are not considered. Rutile-type fine particle titanium dioxide having excellent various properties is used (for example, Japanese Patent Publication No. 1-57084, Japanese Patent Application Laid-Open No. Sho 62-138567).

[Problems to be solved by the invention]

However, fine-grain titanium dioxide has a smaller particle size than pigment-grade titanium dioxide and is photochemically active, and therefore has poorer weather resistance and light discoloration resistance than pigment-grade titanium dioxide. However, there is a problem that the demand cannot be sufficiently satisfied.

Accordingly, an object of the present invention is to provide a rutile-type fine particle titanium dioxide composition imparted with excellent weather resistance and light discoloration resistance without impairing the transparency and ultraviolet light absorption characteristics of the fine particle titanium dioxide. .

[Means for solving the problem]

The present invention, (a rutile type fine particulate titanium dioxide, refers to fine particles of titanium dioxide having a rutile crystal structure) rutile fine particulate titanium dioxide particle surface, in terms of ZrO ₂ 0.5 to 8.0 wt% (TiO ₂ On the basis of zirconium oxide and aluminum oxide of 1.0 to 40.0% by weight (based on TiO ₂ ) in terms of Al ₂ O ₃ , and the zirconium oxide and the aluminum oxide are converted to ZrO ₂ . Converted to 0.
5 to 5.0% by weight (based on TiO ₂ ) of a hydrated oxide of zirconium is deposited, and 1.0 to 10.0 in terms of Al ₂ O ₃ is further deposited thereon.
Excellent weatherability and light tarnishing resistance of the fine particle titanium dioxide by precipitating the hydrated oxide of aluminum by weight (based on TiO ₂ ) without impairing the transparency and ultraviolet absorption characteristic of the fine particle titanium dioxide. , And
The above object has been achieved. Moreover, the rutile-type fine particle titanium dioxide composition is excellent in dispersibility in paints, cosmetics, and resin compositions.

As described above, ZrO ₂
In terms of zirconium oxide and Al ₂ O ₃ in terms of to 0.5 to 8.0 wt% (TiO ₂ basis) from 1.0 to 40.0 wt% (TiO ₂
The method of coating with (reference) aluminum oxide is as follows.

As a starting material, rutile-type fine particle titanium dioxide having an average particle diameter of 0.001 to 0.07 μm is used, this fine particle titanium dioxide is dispersed in water, and a water-soluble salt of zirconium and a water-soluble salt of aluminum are added to the dispersion, By neutralization, 0.5 to 8.0% by weight (based on TiO ₂ ) of zirconium hydrated oxide and 1.0 to 40.0% by weight converted to Al ₂ O ₃ are converted to ZrO ₂ on the particle surface of the fine particle titanium dioxide. % (Ti
(Based on O ₂ ), and then calcined at 300 to 750 ° C. for 1 to 12 hours to convert zirconium hydrated oxide and aluminum hydrated oxide to zirconium oxide and aluminum, respectively. By oxidizing to an oxide of 0.5% to 8.0% by weight (based on TiO ₂ ) of zirconium oxide and 1.0% of Al ₂ O ₃ when the particle surface of the rutile type fine particle titanium dioxide is converted to ZrO _2. A rutile-type particulate titanium dioxide composition coated with 40.0% by weight (based on TiO ₂ ) of aluminum oxide is obtained. In the present invention, the rutile-type particulate titanium dioxide composition in which the surface of the rutile-type particulate titanium dioxide is coated with an oxide of zirconium and an oxide of aluminum is referred to as a first-stage rutile-type particulate titanium dioxide composition.

In the rutile-type fine particle titanium dioxide composition of the first stage, since the particle surface of the fine particle titanium dioxide is coated with zirconium oxide and aluminum oxide, the photochemical activity of the fine particle titanium dioxide is suppressed. In addition, when the hydrated aluminum oxide is calcined to form aluminum oxide, part of the aluminum is dissolved in the titanium dioxide crystal lattice, so Nb mixed in the titanium dioxide crystal lattice Inappropriate charges due to impurities such as ⁵⁺ and voids in the crystal lattice are eliminated, and a decrease in weather resistance due to these impurities and voids is eliminated, and the weather resistance of the fine particle titanium dioxide is improved to some extent.
In addition, the increase in surface hardness due to vitrification by firing also contributes to the improvement of weather resistance, and further, zirconium forms a solid solution in the titanium dioxide crystal lattice similarly to aluminum, and the aluminum titanium dioxide It is considered that the solid solution in the crystal lattice promotes the improvement of weather resistance.

In addition, the rutile-type fine particle titanium dioxide composition of the first stage has a somewhat improved light discoloration resistance as compared with the rutile-type fine particle titanium dioxide itself. This improvement in light discoloration resistance involves the fact that the particle surface of the fine particle titanium dioxide is coated with zirconium oxide.However, when the particle surface of the fine particle titanium dioxide is coated with the zirconium oxide alone, the light resistance is high. The discoloration is not significantly improved, and the light discoloration resistance is improved when the surface of the fine titanium dioxide particles is coated with zirconium oxide in the presence of the aluminum oxide. That is, when the particle surface of the fine particle titanium dioxide is coated with the oxide of zirconium and the oxide of aluminum, it is considered that some synergistic action acts between the two to improve the light discoloration resistance.

In the rutile-type fine particle titanium dioxide composition, the surface of the fine particle titanium dioxide particles is covered with a hydrated oxide of aluminum or a hydrated oxide of zirconium in the firing step in forming the oxide of aluminum. In addition, particle growth during firing is suppressed (this is thought to be due in particular to hydrated oxides of aluminum),
As a result, the particle size distribution width becomes narrower, and particles that can be easily pulverized can be obtained. As a result, fine particles having an average particle diameter of 0.07 μm or less having transparency and ultraviolet ray absorbability can be easily obtained, so that transparency and ultraviolet ray absorbability associated with improvement in weather resistance and light discoloration resistance do not occur.

In the rutile-type fine particle titanium dioxide composition of the first stage of the present invention, the amount of zirconium oxide is adjusted to 0.5 to 8.0% by weight (based on TiO ₂ ) in terms of ZrO ₂ because the zirconium oxide is If it is less than the range, the effect of improving the light discoloration resistance is not sufficiently exhibited, and if the zirconium oxide is more than the above range, it becomes difficult to grind and it is difficult to obtain a narrow particle size distribution width. is there. A particularly preferred amount of this zirconium oxide is Zr
O ₂ in terms of the range of 1.0 to 5.0 wt% (TiO ₂ basis).

Also, converting the amount of aluminum oxide to Al ₂ O ₃
When the amount of aluminum oxide is less than the above range, the effect of improving weather resistance is not sufficiently exhibited, and when the amount of aluminum oxide is more than the above range, the ultraviolet absorbing property is set to 1.0 to 40.0% by weight. Is reduced. A particularly preferred amount of this aluminum oxide is Al
It is in the range of 5.0 to 30.0% by weight (based on TiO ₂ ) in terms of ₂ O ₃ .

In the production of the rutile-type fine particle titanium dioxide composition in the first step, the starting material used had an average particle diameter of 0.001.
Using rutile type fine particle titanium dioxide of ~ 0.07 μm,
The upper limit of the average particle diameter as the starting material is set to 0.07 μm, in order to allow the resulting rutile-type fine particle titanium dioxide composition to have transparency and ultraviolet absorption, and The lower limit of is set to 0.001 μm because it is considered that a smaller one can be used, but at present, such a small one cannot be obtained.

As the rutile-type fine particle titanium dioxide having an average particle diameter of 0.001 to 0.07 μm as described above, for example, a hydrous titanium oxide obtained by hydrolyzing an acidic aqueous solution of titanium or an organic titanium compound is treated with caustic alkali, Rutile-type fine particle titanium dioxide obtained by aging in the above, or rutile-type fine particle titanium dioxide obtained by vapor phase oxidation of titanium tetrachloride in a titania sol state can be used.

Then, these rutile-type fine particle titanium dioxide are dispersed in water, and a water-soluble salt of zirconium and a water-soluble salt of aluminum are added to the dispersion and neutralized, whereby ZrO ₂ is added to the particle surface of the fine particle titanium dioxide. 0.5 to 8.0% by weight (based on TiO ₂ ) of hydrated oxide of zirconium and 1.0 to 40.0% by weight of converted to Al ₂ O ₃ (based on TiO ₂ ) However, as the water-soluble salt of zirconium, for example, zirconium sulfate, zirconium nitrate, zirconium chloride, etc. are used. As the water-soluble salt of aluminum, for example, aluminum chloride, aluminum nitrate, sodium aluminate, aluminum nitrate, etc. are used. Can be Then, for neutralization, for example, a caustic alkali such as ammonium, caustic potash, caustic soda or the like is used. When sodium aluminate or the like is used as the water-soluble salt of aluminum, an acid such as sulfuric acid or hydrochloric acid is used for neutralization. Due to this neutralization, the water-soluble salt of zirconium and the water-soluble salt of aluminum are hydrolyzed to be hydrated oxides of zirconium and aluminum, respectively, and deposited on the surface of the fine titanium dioxide particles. .

Since the hydrated oxide of zirconium and the hydrated oxide of aluminum are mixed in the next firing step, the deposition of the hydrated oxide of zirconium and the hydrated oxide of aluminum may be performed simultaneously, or Either one may be performed first.

The calcination of the hydrated oxide of zirconium and the hydrated oxide of aluminum is performed at 300 to 750 ° C for 1 to 12 hours.

By this calcination, the hydrated oxide of zirconium and the hydrated oxide of aluminum are oxidized to the oxide of zirconium and the oxide of aluminum, respectively. It forms a solid solution in the crystal lattice and is a major factor in exhibiting good weather resistance. Part of zirconium also forms a solid solution in the titanium dioxide crystal lattice, which promotes improvement in weather resistance due to solid solution of aluminum in the titanium dioxide crystal lattice.

During firing, the temperature is specified to be 300 to 750 ° C. If the temperature is lower than 300 ° C, firing does not proceed sufficiently, and if the temperature is higher than 750 ° C, particle growth due to firing increases. This is because it is difficult to obtain particles having an average particle diameter of 0.07 μm or less. Also, the firing time is 1 to
What is specified as 12 hours depends on the relationship with the firing temperature, but if the firing time is too short, the particle growth will be too large, so that firing can be performed sufficiently, and the particle growth will be large. This is in order not to become too much. In other words, by performing firing at a temperature of 300 to 750 ° C. for 1 to 12 hours, sufficient firing is achieved, and the average particle size is 0.01 to 0.07 μm.
Thus, a first-stage rutile-type fine particle titanium dioxide composition having transparency and ultraviolet absorption within the range of m can be obtained. However, the average particle diameter of the primary particles is in the range of 0.01 to 0.07 μm, but the one after firing is apparently agglomerated into a lump, so that it is pulverized (crushed to a degree of loosening). There is a need.

Next, as described above, the zirconium oxide and the aluminum oxide of the rutile-type fine particle titanium dioxide composition in which the particle surfaces of the rutile-type fine particle titanium dioxide were coated with zirconium oxide and aluminum oxide were further coated on the zirconium oxide. By depositing a hydrated oxide of aluminum and a hydrated oxide of aluminum, the rutile-type particulate titanium dioxide composition with improved weather resistance and light discoloration resistance can be obtained without impairing transparency and ultraviolet absorption. can get. This rutile-type fine particle titanium dioxide composition is particularly excellent in dispersibility in paints, cosmetics, and resin compositions.

The above-described rutile-type fine particle titanium dioxide composition is obtained by coating the particle surface of the rutile-type fine particle titanium dioxide with a zirconium oxide and an aluminum oxide, and then coating the zirconium oxide and the aluminum oxide with water of zirconium. It is produced by depositing a hydrated oxide and then a hydrated oxide of aluminum.

In this rutile-type particulate titanium dioxide composition, the hydrated oxide of zirconium is deposited on the oxide of zirconium and the oxide of aluminum, because the rutile-type particulate titanium dioxide composition of the first stage has a light discoloration resistance. This zirconium hydrated oxide is converted to ZrO ₂ in an amount of 0.5 to 5.0% by weight (Ti
O ₂ standard) Deposit. In addition, the hydrated oxide of aluminum is deposited on the hydrated oxide of zirconium,
Aluminum hydrated oxide is well compatible with paint and cosmetic compounding materials, so by dispersing aluminum hydrated oxide in the outermost layer, dispersibility in paints and cosmetics can be improved. The aluminum hydrated oxide is deposited in an amount of 1.0 to 10.0% by weight (based on TiO ₂ ) in terms of Al ₂ O ₃ . However, since the surface of the rutile-type titanium dioxide particles is not necessarily smooth and has irregularities, even if the hydrated oxide of aluminum is deposited so as to be the outermost layer as described above, water of aluminum is present on all surfaces. The hydrated oxide does not always constitute the outermost layer, and the hydrated oxide of zirconium may partially constitute the outermost layer.

In this rutile-type fine particle titanium dioxide composition, the upper limit of the amount of the hydrated oxide of zirconium deposited on the oxide of zirconium and the oxide of aluminum is Zr.
In terms of O ₂ 5.0 wt% of that in the (TiO ₂ basis),
If the deposition amount of the hydrated oxide of zirconium is larger than the above, the dispersibility in paints, cosmetics, resin compositions, etc. is reduced, and the lower limit is 0.5% by weight in terms of ZnO ₂ (based on TiO ₂ ).
The reason for this is that if the amount of the hydrated oxide of zirconium is smaller than the above, the light discoloration resistance cannot be sufficiently improved, and the hydration of aluminum deposited on the hydrated oxide of zirconium cannot be improved. The upper limit of oxide deposition is Al
_The reason why it is 10.0 wt% (based on TiO ₂ ) in terms of ₂ O ₃ is that when the amount of hydrated oxide of aluminum deposited becomes larger than the above, the ultraviolet absorption decreases, and the lower limit is Al ₂ O ₃ 1.0% by weight (based on TiO ₂ ) is that when the amount of aluminum hydrated oxide deposited is less than the above,
This is because the dispersibility in paints, cosmetics, resin compositions, and the like cannot be sufficiently improved.

In producing the rutile-type particulate titanium dioxide composition in which a hydrated oxide of zirconium and a hydrated oxide of aluminum are deposited on the oxide of zirconium and the oxide of aluminum, a water-soluble salt of zirconium and a water-soluble aluminum The same salts and the like as described above are used, but when hydrated oxides of zirconium and aluminum are deposited, hydrated oxides of titanium, silicon (silicon), antimony, tin, etc. are deposited together with them. One or more of the objects may be deposited simultaneously.

Since the rutile-type fine particle titanium dioxide composition of the present invention has good transparency, it may affect the hue of the colorant when blended in paints, inks, resin compositions, cosmetics, and the like. Absent. Further, in metallic coating, the use of fine titanium dioxide and a metal or a metal-like pigment has been carried out to improve the color by imparting a down-flop property, in which case, the rutile-type fine particles of the present invention are used. When the titanium dioxide composition is used, weather resistance and light discoloration resistance are excellent, so that deterioration of the coating film can be prevented.

In the present invention, the rutile-type fine particle titanium dioxide composition needs to have an average particle diameter in the range of 0.01 to 0.07 μm, which has transparency and ultraviolet absorption within a practical range. In order to be able to have, when the average particle size is smaller than 0.01μm, although the transparency is improved, the dispersibility in paints, resin compositions and the like is worse, and the average particle size is larger than 0.07μm This is because transparency and ultraviolet absorption are impaired.

As in the case of the rutile-type fine particle titanium dioxide composition of the present invention, those obtained by coating the surface of the fine particle titanium dioxide with a metal compound have not yet been disclosed in JP-A-55-10428 or JP-A-55-105428. Japanese Patent No. 1534317 proposes to coat the particle surface of fine particle titanium dioxide with oxides of silicon and aluminum to improve the transparency and ultraviolet absorption of the fine particle titanium dioxide. In this case, the transparency and the ultraviolet absorption are improved, but the weather resistance is not improved as much as in the present invention. This is considered to be because a synergistic effect does not occur between the oxide of aluminum and the oxide of silicon with respect to the improvement of weather resistance.

Also, JP-A-57-71822 and JP-A-61-141616 disclose that the particle surface of the fine particle titanium dioxide is coated with an oxide of tin and antimony to impart conductivity to the fine particle titanium dioxide. Has been proposed. However, in this case, although the conductivity is imparted, the weather resistance and the light discoloration resistance hardly improve.

〔Example〕

Next, the present invention will be described more specifically with reference to examples. In the following, the percentages indicating the concentrations are all% by weight.
It is due to. Prior to the description of the examples, the production of the rutile-type fine particle titanium dioxide composition in the first stage will be described as Reference Example 1.

Reference Example 1 A titanyl sulfate solution was heated and hydrolyzed by a conventional method, filtered, and washed to obtain 95 kg of an aqueous titanium oxide slurry (Ti
7.3 kg of a 48% aqueous solution of caustic soda was added to O _{2 (} equivalent to 10 kg) with stirring, and the mixture was aged at 95 ° C. for 2 hours.

Next, 48 kg of 35% hydrochloric acid was added to 205 kg of the slurry obtained by washing the treated caustic soda while stirring, and 9 kg of the slurry was added.
The mixture was heated and aged at 5 ° C. for 2 hours to prepare a titania sol.

The titania sol thus obtained was filtered, washed, dried at 150 ° C. for 30 minutes, and the average particle size was 0.015 μm.
m of rutile-type fine particle titanium dioxide was obtained.

100 kg of water is added to 9.7 kg of rutile-type fine particle titanium dioxide having an average particle diameter of 0.015 μm obtained as described above, and zirconium sulfate is added thereto while stirring with ZrO _2.
0.7 kg of zirconium sulfate aqueous solution containing 15%
5 kg of an aluminum chloride aqueous solution containing 10% of aluminum chloride in terms of Al ₂ O ₃ and neutralized with 25% aqueous ammonia to form 1.0% in terms of ZrO ₂ on the surface of fine titanium dioxide particles A hydrated oxide of zirconium (based on TiO ₂ ) and aluminum hydrated oxide of 5.0% (based on TiO ₂ ) in terms of Al ₂ O ₃ are deposited, and then
After heating at ℃ for 30 minutes, filtration, washing, then 150 ℃
For 30 minutes.

The obtained dried product is calcined at 500 ° C. for 3 hours, and then pulverized by an energy mill to convert the surface of the rutile-type fine particle titanium dioxide particle to 1.0% (based on TiO ₂ ) zirconium oxide in terms of ZrO ₂ . And 5.0 in terms of Al ₂ O ₃
% (Based on TiO ₂ ) to obtain 9.0 kg of a rutile-type fine particle titanium dioxide composition having an average particle diameter of 0.028 μm coated with an aluminum oxide.

FIG. 1 shows an X-ray diffraction diagram of the thus obtained rutile-type fine particle titanium dioxide composition of Reference Example 1 (that is, the first-stage rutile-type fine particle titanium dioxide composition). FIG. 1 also shows an X-ray diffraction diagram of the rutile-type fine particle titanium dioxide of Comparative Example 1 described later (that is, an equivalent of ordinary rutile-type fine particle titanium dioxide). As is clear from comparison of the X-ray diffraction pattern of the fine particle titanium dioxide composition with the X-ray diffraction pattern of the rutile type fine particle titanium dioxide of Comparative Example 1, the rutile type fine particle titanium dioxide composition of Reference Example 1 was the same as that of Comparative Example 1. 1 has a peak at almost the same position as that of the rutile-type fine particle titanium dioxide, and it can be seen from FIG. 1 that the rutile-type fine particle titanium dioxide composition of Reference Example 1 has a rutile-type crystal structure. .

FIG. 2 is a diagram showing a particle size distribution curve of the rutile type fine particle titanium dioxide composition of Reference Example 1, and FIG. 2 also shows a particle size distribution curve of the rutile type fine particle titanium dioxide of Comparative Example 1 described later. . The measurement of the particle size is based on an electron micrograph.

As shown in FIG. 2, the particle size distribution width of the rutile-type fine particle titanium dioxide composition of Reference Example 1 was 0.0075 to 0.0625 μm.
As can be seen by comparing the particle size distribution curve of the rutile-type fine particle titanium dioxide composition of Reference Example 1 with the particle size distribution curve of the rutile-type fine particle titanium dioxide of Comparative Example 1, the rutile of Reference Example 1 The fine particle titanium dioxide composition has a narrower particle size distribution width than the rutile fine particle titanium dioxide of Comparative Example 1.

In the present Reference Example 1, rutile-type fine particle titanium dioxide obtained by hydrolyzing a titanyl sulfate solution and then drying a titania sol obtained by treating with caustic soda and aging with hydrochloric acid was used as a starting material. It can be used as a starting material in a titania sol state without going through a simple drying step.

Example 1 The particle surface of the rutile-type fine particle titanium dioxide obtained in Reference Example 1 was converted to ZrO ₂ , which was 1.0% (based on TiO ₂ ), an oxide of zirconium and Al ₂ O ₃ , which was 5.0% ( Disperse 10 kg of rutile-type fine particle titanium dioxide composition (that is, the first stage rutile-type fine particle titanium dioxide composition) coated with aluminum oxide (based on TiO ₂ ) in water, and heat the obtained slurry to 50 ° C. After that, 98% sulfuric acid was added so that the pH of the slurry became 2, and then zirconium sulfate was added to Zr.
1.3k aqueous zirconium sulfate solution containing 15% in terms of O ₂
g, and neutralized by adding a 20% aqueous solution of caustic soda to 2.0% in terms of ZrO ₂ (based on TiO ₂ ) on zirconium oxide and aluminum oxide of the rutile type fine particle titanium dioxide composition Of hydrated zirconium oxide, and then 0.3 kg of an aqueous sodium aluminate solution and 0.1 kg of 98% sulfuric acid in terms of Al ₂ O ₃ having a slurry pH of 5
At the same time so that the hydrated oxide of aluminum is deposited on the hydrated oxide of zirconium in an amount of 3.0% (based on TiO ₂ ) in terms of Al ₂ O _3. After heating and ripening while maintaining the pH of the slurry at 8 for 30 minutes, the slurry was filtered and washed, and then dried at 150 ° C. for 30 minutes.

The obtained dried product is pulverized with an energy mill to convert the surface of the rutile-type fine titanium dioxide particles to ZrO ₂ and convert it to zirconium oxide (1.0% (based on TiO ₂ )) and Al ₂ O _3. 5.0% was coated with an oxide of aluminum (TiO ₂ basis), 2.0% in terms of ZrO ₂ thereon (TiO ₂
Zirconium hydrous oxide of reference) was deposited by the average particle diameter of aluminum were deposited hydrated oxide of that on the Al ₂ O ₃ 3.0% in terms of (TiO ₂ basis) 0.028μm
To obtain 10.3 kg of a rutile-type fine particle titanium dioxide composition.

Example 2 The zirconium sulfate in Example 1 was converted to ZrO _2.
Instead of 1.3 kg of zirconium sulfate aqueous solution containing 15%,
Except that 2.5 kg of an aqueous zirconium sulfate solution containing 15% of the above zirconium sulfate in terms of ZrO ₂ was added, 9.8 kg of a rutile-type particulate titanium dioxide composition having an average particle diameter of 0.028 μm was prepared in the same manner as in Example 1. Obtained. Thus rutile particles titanium dioxide composition obtained is in terms of the particle surface of the rutile fine particulate titanium dioxide ZrO ₂ 1.0
% (Based on TiO ₂ ) and an aluminum oxide of 5.0% (based on TiO ₂ ) in terms of Al ₂ O ₃ , and ZrO ₂ on the zirconium oxide and the aluminum oxide. 3.8% (based on TiO ₂ ) of hydrated oxide of zirconium is deposited, and Al ₂ O
3.0% (based on TiO ₂ ) of hydrated oxide of aluminum deposited in terms of ₃ .

FIG. 3 shows a spectral curve of the rutile-type fine particle titanium dioxide composition obtained in Examples 1 and 2 in comparison with a spectral curve of the rutile-type fine particle titanium dioxide of Comparative Example 1 described later.

Comparative Example 1 95 kg of a titanium oxide hydrated slurry obtained by subjecting a titanyl sulfate solution to hydrolysis by heating in a conventional manner, filtration and washing were used.
7.3 kg of a 48% aqueous solution of caustic soda was added to the mixture (equivalent to 10 kg in terms of O ₂ ) while stirring, and aged at 95 ° C. for 2 hours.

Slurry 20 obtained by washing this caustic soda treated product
48 kg of 35% hydrochloric acid is added to 5 kg with stirring.
The mixture was heated and aged to prepare a titania sol.

The titania sol thus obtained was filtered, washed, and dried at 150 ° C. for 30 minutes.

The obtained dried product is calcined at 500 ° C. for 3 hours, and then pulverized by an energy mill to have an average particle size of 0.031 μm.
m of rutile-type fine particle titanium dioxide was obtained.

FIG. 1 shows an X-ray diffraction pattern, a particle size distribution curve of the rutile type fine particle titanium dioxide of Comparative Example 1, and FIG. 3 a spectral curve.

Comparative Example 2 An average particle diameter was 0.031 μm in the same manner as in Reference Example 1, except that 5 kg of an aluminum chloride aqueous solution containing 10% of aluminum chloride in terms of Al ₂ O ₃ was not added. Rutile type fine particle titanium dioxide composition 10.
0 kg was obtained. The thus obtained rutile-type fine particle titanium dioxide composition is obtained by coating the particle surface of the rutile-type fine particle titanium dioxide with only 1.0% (based on TiO ₂ ) zirconium oxide in terms of ZrO _2. .

Comparative Example 3 In the same manner as in Reference Example 1, except that 0.7 kg of an aqueous zirconium sulfate solution containing 15% zirconium sulfate in terms of ZrO ₂ was not added, the average particle diameter was 0.032 μm. Rutile-type fine particle titanium dioxide composition 9.8
kg gained. The thus obtained rutile-type fine particle titanium dioxide composition is obtained by coating the particle surface of the rutile-type fine particle titanium dioxide with only aluminum oxide of 5.0% (based on TiO ₂ ) in terms of Al ₂ O _3. It is.

The average particle size obtained in Comparative Example 4 Comparative Example 1 is 20% of the aqueous slurry of rutile type fine particulate titanium dioxide 9.0kg of 0.031μm as TiO _2, SiO ₂ 100 g, corresponding to 1.0 percent TiO ₂ reference therein
/ Containing sodium silicate solution (SiO ₂ / Na ₂ O molar ratio 0.5) 900 ml
Was added to disperse the titanium dioxide, and the mixture was wet-ground in a quick mill for 1 hour. Then, TiO ₂ was added to this dispersed slurry.
Was added Al ₂ O ₃ 50g / aluminum sulfate aqueous solution 9,000ml equivalent to 5% in terms of Al ₂ O ₃ by the reference, a hydrated oxide is deposited on the surface of the fine powder was neutralized, the fine After the powder is filtered, washed and dried at 110 ° C., the dried product is baked at 500 ° C. for 3 hours, and the obtained baked product is pulverized by an energy mill to obtain a rutile-type particulate titanium dioxide having an average particle size of 0.031 μm. 8.8 kg of the composition were obtained. The thus-obtained rutile-type fine particle titanium dioxide composition is obtained by converting the surface of the rutile-type fine particle titanium dioxide particle to SiO ₂ and converting it to 1.0% (based on TiO ₂ ) silicon oxide and Al ₂ O ₃ . And 5.0% (Ti
It is coated with an aluminum oxide (based on O ₂ ).

Next, the rutile-type fine particle titanium dioxide composition obtained in Examples 1 and 2, the rutile-type fine particle titanium dioxide obtained in Comparative Example 1, and the rutile-type fine particle titanium dioxide composition obtained in Comparative Examples 2 to 4 The results obtained by examining the light transmittance, weather resistance and light discoloration resistance of the sample are shown below.

(1) Light Transmittance The paint preparation conditions, coating film preparation conditions, light transmittance measurement conditions, and measurement results for measuring the light transmittance are as follows.

(1) -1 Conditions for preparing paint A paint was prepared by charging each material in the following mixing ratio into a 200 ml-volume bottle and dispersing it for 2 hours with a paint shaker.

Titanium dioxide sample 8.0 g Acrylic resin (50%) 16.0 g Mixed solvent 24.0 g Zircon beads (0.8 mm) 250 g The above titanium dioxide sample is the rutile-type fine particle titanium dioxide composition of Examples 1-2 and Comparative Example 1. The rutile-type fine particle titanium dioxide and the rutile-type fine particle titanium dioxide of Comparative Examples 2 to 4 are collectively shown, and the acrylic resin is Acrydic 47-712 manufactured by Dainippon Ink and Chemicals, Inc.
In (trade name), the numerical value in parentheses indicates the solid content concentration. The mixed solvent was toluene / xylene / ethyl acetate / butyl cellosolve = 5/2/2/1 (volume ratio), and the numerical value in parentheses after the zircon beads indicates the diameter of the zircon beads.

(1) -2 Preparation condition of coating film After the above coating material was applied to a polyethylene terephthalate film [Luciler # 100 (trade name) manufactured by Panac Co., Ltd.] with a bar coder # 22 (trade name manufactured by Daisuke Kikai Co., Ltd.) to a dry film thickness of 10 μm. Set at room temperature for 30 minutes, then at 140 ° C
For 30 minutes to cure the coating.

(1) -3 Measurement Conditions of Light Transmittance The above coating film was measured for light transmittance at a wavelength of 300 to 700 nm using a spectrophotometer [U-3410 (trade name) manufactured by Hitachi, Ltd.] to obtain a light transmittance of 400 to 700 nm. The light transmission area of the wavelength is determined, and the quality of the light transmission is determined based on the light transmission area. The larger the light transmission area, the better the light transmittance of the titanium dioxide sample.

(1) -4 Measurement results Table 1 shows the light transmission areas determined as described above.

As shown in Table 1, the rutile-type fine particle titanium dioxide compositions of Examples 1 and 2 have a larger light transmission area than the rutile-type fine particle titanium dioxide of Comparative Example 1, and the surface of the particles has an oxide of zirconium. There was no decrease in light transmittance due to coating with aluminum or an oxide of aluminum, and good transparency was obtained.

Further, as shown in FIG. 3, the rutile-type fine particle titanium dioxide compositions of Examples 1 and 2 show only a very small transmittance in a wavelength region smaller than 400 nm (that is, ultraviolet), and exhibit ultraviolet absorption. Had. Further, in the visible part (the part having a wavelength of about 400 nm or more), the transmittance of the rutile-type particulate titanium dioxide compositions of Examples 1 and 2 is higher than that of the rutile-type particulate titanium dioxide of Comparative Example 1, and the transparency is rather high. It was excellent. Note that there is almost no difference in transmittance between the rutile-type fine particle titanium dioxide composition of Example 1 and the rutile-type fine particle titanium dioxide composition of Example 2, and even if the respective spectral curves are shown, they overlap. In FIG. 3, the same curve shows the spectral curve of the rutile-type fine particle titanium dioxide composition of Example 1 and the spectral curve of the rutile-type fine particle titanium dioxide of Example 2.

(2) Weather resistance and light discoloration resistance test The paint preparation conditions, coating film preparation conditions, exposure conditions, gloss measurement conditions, and color difference measurement conditions for the weather resistance and light discoloration resistance tests are as follows. In this weather resistance and light discoloration resistance test, the rutile type fine particle titanium dioxide composition of the present invention was used as a control to clarify the degree of weather resistance and light discoloration resistance to pigment grade titanium dioxide. As Example 1, the results of a test on the weather resistance and light discoloration resistance of a pigment-grade titanium dioxide having an average particle diameter of 0.27 μm [JR-701 (trade name) manufactured by Teika Co., Ltd.] are also shown.

(2) -1 Paint preparation conditions (a) Each material was charged into a bottle having an inner volume of 200 ml at the following compounding ratio, and dispersed for 2 hours with a paint shaker to prepare a mill base.

Titanium dioxide sample 8.0 g Acrylic resin (50%) 16.0 g Mixed solvent 24.0 g Zircon beads (0.8 mm) 250 g The above acrylic resin is Acrydic 47-712 (trade name) manufactured by Dainippon Ink and Chemicals, in the same manner as above. The mixed solvent is a mixed solvent of toluene / xylene / ethyl acetate / butyl cellosolve = 5/2/2/1 (volume ratio).

(B) To the mill base obtained in (a) above, a resin and a solvent were further added at the following ratios and mixed to prepare a paint.

Acrylic resin (50%) 6.4 g Melamine resin (60%) 8.0 g Mixed solvent 4.0 g The acrylic resin and mixed solvent are the same as those used above, and the melamine resin is a supermarket manufactured by Dainippon Ink and Chemicals, Inc. In Becamine 2-117 (trade name), the numerical value in parentheses indicates the solid content concentration.

(2) -2 Conditions for preparing coating film A mixed solvent similar to the above [a mixed solvent of toluene / xylene / ethyl acetate / butyl cellosolve = 5/2/2/1 (volume ratio)] was applied to the coating material prepared in (2) -1. Was adjusted to 14 seconds with a Ford cup # 4, spray-coated on a treated steel sheet so that the dry film thickness became 25 μm, set at room temperature for 8 minutes, and baked at 140 ° C. for 30 minutes, The coating was cured.

(2) -3 Exposure conditions The test plate having the coating film formed on the treated steel plate as described above was subjected to accelerated exposure and outdoor exposure under the following conditions.

(A) Accelerated exposure conditions a. Testing Machine Sunshine Super Long Life Weather
Ometer WEL-SUN-HCH type (Suga Test Instruments Co., Ltd., trade name) b. Operating conditions Test tank temperature 40 ° C Black panel temperature 63 ± 3 ° C Rainfall time 18 minutes Cycle 120 minutes 1 cycle 60 hours Shower water Ion-exchanged water (b) Outdoor exposure conditions Exposure location Okayama city Exposure conditions South side 30 degrees Panel cleaning 1 month Each (2) -4 Gloss measurement conditions Specular gloss value (at accelerated exposure) and 20 ゜ -20 ゜ of the coating film before and after exposure were measured with a gloss meter [UGV-4D (trade name) manufactured by Suga Test Instruments Co., Ltd.). The {-60} specular reflection gloss value (when exposed outdoors) is measured, and the gloss retention is determined by the following equation.

The greater the gloss retention, the better the weather resistance.

(2) -5 Color difference measurement conditions The color difference meter [SM-5 (trade name) manufactured by Suga Test Instruments Co., Ltd.]
The L, a, and b values of the coating film before and after exposure are measured, ΔE is calculated, and the light discoloration resistance is evaluated.

The ΔE value is calculated by the following equation, where the L ₁ , a ₁ , and b ₁ values are measured values before exposure, and are L ₂ , a ₂ ,
b ₂ values are measured after exposure. The smaller the ΔE value, the better the light discoloration resistance.

(2) -6 Weather resistance and light discoloration resistance test results Table 2 shows the weather resistance and light discoloration resistance test results during accelerated exposure, and Table 3 shows the weather resistance test results during outdoor exposure.

As shown in Table 2, in the weathering test during accelerated exposure,
Rutile-type fine particle titanium dioxide compositions of Examples 1 and 2,
Compared to the rutile-type fine particle titanium dioxide of Comparative Example 1, the gloss retention was large, and the weather resistance was equal to or higher than that of the pigment-grade titanium dioxide of Comparative Example 1. Also, in the light discoloration resistance test, the rutile-type fine particle titanium dioxide compositions of Examples 1 and 2 have smaller ΔE than the rutile-type fine particle titanium dioxide of Comparative Example 1, and the pigment-grade titanium dioxide of Comparative Example 1 It had excellent light discoloration resistance comparable to that of.

Further, as shown in Table 3, in the weather resistance test at the time of outdoor exposure, the rutile-type fine particle titanium dioxide compositions of Examples 1 and 2 exhibited higher gloss retention than the rutile-type fine particle titanium dioxide of Comparative Example 1. The ratio was large, and it had excellent weather resistance equal to or higher than that of the pigment-grade titanium dioxide of Comparative Example 1.

〔The invention's effect〕

As described above, the rutile-type fine particle titanium dioxide composition of the present invention is excellent in weather resistance and light discoloration resistance. Further, the rutile-type fine particle titanium dioxide composition of the present invention has transparency and ultraviolet absorption, and there is no decrease in transparency and ultraviolet absorption due to improvement in weather resistance and light discoloration resistance.

[Brief description of the drawings]

FIG. 1 is an X-ray diffraction diagram of the rutile-type fine particle titanium dioxide composition of Reference Example 1 and the rutile-type fine particle titanium dioxide of Comparative Example 1. FIG. 2 is a diagram showing the particle size distribution curves of the rutile-type fine particle titanium dioxide composition of Reference Example 1 and the rutile-type fine particle titanium dioxide of Comparative Example 1. FIG. 3 shows the first embodiment.
2 is a diagram showing spectral curves of the rutile-type fine particle titanium dioxide compositions of Comparative Examples 1 and 2 and the fine particle titanium dioxide of Comparative Example 1. FIG.

Claims (2)

(57) [Claims] 1. A particle surface of rutile-type fine particle titanium dioxide is converted to ZrO ₂ in an amount of 0.5 to 8.0% by weight (based on TiO ₂ ) and 1.0 to 40.0% by weight in terms of zirconium oxide and Al ₂ O _3. Coated with aluminum oxide (based on TiO ₂ ), and on the zirconium oxide and aluminum oxide
In terms of ZrO ₂ 0.5 to 5.0 wt% of deposited zirconium oxide hydrate of (TiO ₂ basis), 1.0 to 10.0 wt% in terms further Al ₂ O ₃ thereon (TiO ₂ basis) Average particle size of hydrated aluminum oxide deposited is 0.01-0.07μm
Rutile-type fine particle titanium dioxide composition having high weather resistance and high light tarnish resistance. 2. Rutile-type fine particle titanium dioxide having an average particle diameter of 0.001 to 0.07 μm is dispersed in water, and a water-soluble salt of zirconium and a water-soluble salt of aluminum are added to the dispersion to neutralize the dispersion. 0.5 to 8.0% by weight (based on TiO ₂ ) of hydrated oxide of zirconium and Al ₂ O on the surface of the fine titanium dioxide particles in terms of ZrO _2
A hydrated oxide of aluminum is deposited in an amount of 1.0 to 40.0% by weight (based on TiO ₂ ) in terms of ₃ , and then calcined at 300 to 750 ° C. for 1 to 12 hours to obtain a hydrated oxide of zirconium and water of aluminum. The oxidized oxide is oxidized to zirconium oxide and aluminum oxide, respectively, so that the surface of the rutile-type fine titanium dioxide particles becomes Zr.
In terms of O ₂ 0.5 to 8.0 wt% in terms oxide of zirconium (TiO ₂ basis) and the Al ₂ O ₃ 1.0 to 40.0% by weight (Ti
A rutile-type particulate titanium dioxide composition coated with an oxide of aluminum (based on O ₂ ) was prepared. Next, the rutile-type particulate titanium dioxide composition was dispersed in water, and a water-soluble salt of zirconium was added to the dispersion. By adding and neutralizing, on the zirconium oxide and the aluminum oxide of the rutile-type fine particle titanium dioxide composition,
The hydrated oxide of zirconium is deposited by depositing 0.5 to 5.0% by weight (based on TiO ₂ ) of hydrated oxide of zirconium in terms of ZrO ₂ , and then adding and neutralizing a water-soluble salt of aluminum. 1.0 to 10.0% by weight in terms of Al ₂ O <sub>3
2. The</sub> process for producing a rutile-type particulate titanium dioxide composition according to claim 1, wherein a hydrated oxide of aluminum (based on TiO2) is deposited.