JP3254705B2 - Photochromic titanium oxide compound - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paint, printing, resin coloring, cosmetic, and the like having a color rendering effect of photochromic property.
The present invention relates to a titanium oxide compound suitable for fields such as optical memory.

[0002]

2. Description of the Related Art Conventionally, as represented by sunglasses,
A unique function called photochromism, in which the color reversibly changes depending on the intensity of light, is being used. Silver halides and spiropyran-based organic compounds are already known as chemical substances that exhibit photochromism. It is known that titanium oxide exhibits photochromism in the presence of metals such as iron, chromium, and manganese.
It is disclosed in O-89 / 12084.

[0003] However, as disclosed in the above patent, the metal powder itself that imparts photochromic properties to titanium oxide or its metal salt, oxide, or hydroxide such as sulfate, chloride, nitrate, or acetate is simply prepared. The degree of photochromism that is manifested by mixing and baking alone is weak, and in fact, this degree of change in chromaticity dilutes the effect when mixed with other components in various applications. Therefore, a change in color tone was hardly recognized, and the utility value in practical use was low.

[0004]

In view of such circumstances, the present inventors have conducted intensive studies to obtain titanium oxide having photochromic properties that can be provided to a practical level. Alternatively, it has been found that when a specific amount of sodium oxide is present in the metal compound, a titanium oxide-based compound satisfying the above characteristics can be obtained, thereby completing the present invention.

[0005]

That is, the present invention relates to a metal compound comprising at least one of iron, chromium, copper, nickel, vanadium and manganese, wherein the sodium compound is 0.1 to less than 1.0% by weight in terms of sodium oxide. in but 0.2 to 8.0 wt% and the titanium compound in terms of titanium oxide in the metal oxide conversion, the titanium oxide compound having a sum comprising the construction described up to 100% by weight photochromic with the two-component ( Disperse titanium oxide in deionized water
And further add iron sulfate, iron chloride, iron nitrate or iron acetate,
Stir and add sodium hydroxide to neutralize and react.
And then the residue obtained by filtration is washed with water, dried, calcined,
Excluding those obtained by grinding) .

Hereinafter, the present invention will be described in more detail. In the titanium oxide-based compound of the present invention, the sodium compound is 0.1 to less than 1.0% by weight in terms of sodium oxide, iron, chromium,
The metal compound comprising at least one of copper, nickel, vanadium and manganese is 0.2 to 8.
0% by weight and the titanium compound are 100% by weight in terms of titanium oxide in total with the two components.

When the content of the above metal compounds such as iron and chromium in the titanium oxide-based compound is less than 0.2% by weight in terms of metal oxide, the photochromic property is poorly expressed, and 8.0 is obtained.
Even if it exceeds 10% by weight, there is no effect of developing photochromic properties commensurate with the amount present, the coloring of the added metal itself increases, and the degree of discoloration due to photochromism decreases relatively. If the amount of sodium oxide is less than 0.1% by weight, the photochromic property is poorly expressed.

In the present invention, the titanium oxide-based compound having the above-mentioned composition is not particularly limited in its shape, and is manufactured and used in the form of particles, plates or flakes in various applications. For example, particulate materials are in the fields of paint, printing, resin coloring, etc., while plate-shaped or flake-shaped materials are in the field of rust-preventive paints that make use of the function of blocking the transmission of oxygen and water. It is suitable for the field of paint, resin coloring and printing using pearlescent pigments utilizing the interference function, and also for the field of cosmetics utilizing the function of adhesion and spreadability of flakes.

[0009] The color rendering effect of photochromic property means that when the degree of blackening is high and the fading property is good, paint, printing,
It is suitable for fields such as resin coloring and cosmetics. On the other hand, when the degree of blackening is high and the fading property is poor, it is suitable for fields such as sensors and optical memories. Therefore, the best photochromic property and shape for each application may be selected and applied. Hereinafter, the method for producing the titanium oxide-based compound of the present invention will be described in detail. As for the particulate matter, the mixture of the above composition is dried (including static drying, drum drying, spray drying, etc.), calcining,
If necessary, a known production method such as pulverization can be easily considered, and here, a production example of a plate-like or flaky titanium oxide-based compound will be described.

In the practice of the present invention, the organotitanium compound used is represented by the general formula TiO _2-x (OX) _l (OR) _m (OH) _n (where OX represents an acyloxy group, OR represents an alkoxy group, and x = l + m + n, where x and m are> 0 <2
, And l and n are positive numbers including zero of 0 to <2)
Wherein OX is about 0.3 to 1 mol of TiO _2.
It is an organic titanium compound having an OR of about 0.05 to 0.15 mol, and an organic titanium compound produced by a known method disclosed in JP-A-60-176906 can be used.

For example, titanium alkoxides, particularly partially acyloxylated titanium alkoxides, alone or diluted in an organic solvent, are coated on a supporting substrate to a desired thickness to form a liquid thin film. After further evaporating the solvent, it is further subjected to partial hydrolysis by contact with water vapor to form a thin piece of the organic titanium compound, and this thin piece can be scraped off by a suitable scraping operation.

Titanium alkoxides used for forming flakes include alkoxides with alcohols having 1 to 17 carbon atoms, particularly industrially, tetra-i-propoxytitanium, tetra-n-butoxytitanium, tetrakis (2-ethylhexoxy). ) Titanium, tetrastearoxytitanium and the like are commercially available, and among them, tetra-i-propoxytitanium is preferable from the viewpoint of economy. These alkoxides can be hydrolyzed in advance and used in the form of trimers, tetramers, oligomers and the like.

The presence of the partial acyloxy group has an effect on the releasability of the formed thin film from the supporting substrate, the controllability of the shape of the obtained flakes and the smoothness of the flakes.

The organic solvent used for forming the liquid film may be any solvent which can dissolve the alkoxides of titanium or titanium alkoxides which are partially acyloxylated. 7
Solvents having a boiling range of about 0 to 150 ° C. are preferred.

As such an organic solvent, for example, hydrocarbons such as toluene, xylene, heptane and cyclohexane and alcohols such as ethanol, propanol and butanol can be used alone or in combination. Industrially, if the same alcohol as the alkoxide is used,
Advantageously, there is no need to separate and purify the recovered solvent.

The support substrate on which the film is formed may be a flat plate, but for continuous production on an industrial scale, a drum flaker or an endless plate processed into a belt shape is used. The material of the base material is glass, metals such as chromium and nickel, ceramics such as alumina and tungsten carbide,
Resins such as unsaturated polyester and Teflon can be used. In selecting these materials, although it is not unambiguous from the peelability of the formed thin film and the peeling means and the physical properties of the raw materials used, in general, metal drums, alumina if chemical resistance and wear resistance are important, Thermal spray drums are preferred.

In the liquid film formed on the base material, the solvent is evaporated from the liquid film by heat treatment. Evaporation and removal of the solvent from the liquid film may be performed by heating the supporting substrate from the inside, blowing hot air to the surface of the liquid film, or a combination thereof. However, excessive heating causes boiling of the solvent and flake formation. Heating, the heating is below the boiling point of the solvent composition of the liquid film,
In the case of using hot air, it is preferable to use a hot air flow in an amount that does not impair the smoothness of the liquid film surface depending on the amount of the blown air from the viewpoint of obtaining a flake having a uniform thickness.

The liquid film on the supporting substrate from which the solvent has been removed by heating is:
Next, it is forcibly hydrolyzed by humidified air such as steam to form a solid film on the supporting substrate. The formed solid film shrinks in volume with the progress of hydrolysis, causing cracks in the thin film and thinning. As a method of peeling the flaky material formed on the supporting substrate from the substrate, a method of mechanically scraping with a scraper or the like is usually employed. And, when the substrate is flexible, a method in which the substrate is bent and peeled.

In the practice of the present invention, titania sol may be used as a titanium oxide raw material. The titania sol is not particularly limited as long as it is a known one usually used for the production of a thin film, but the workability at the time of forming a liquid film or the amount of an economically volatile dispersion medium in drying the formed liquid film is reduced. From the viewpoint, an aqueous sol having a solid concentration of generally 5 to 40% by weight, preferably 10 to 30% by weight is used. The method for producing a flake using a titania sol can be obtained according to the above-described method for producing a flake using titanium alkoxides as a raw material.

The metal or metal compound imparting photochromic properties used in the present invention includes iron, chromium,
Copper, nickel, metal or metal compound consisting of at least one of vanadium and manganese, more specifically iron, chromium, copper, nickel, metal powder of vanadium and manganese, oxides, hydroxides of these metals or Amorphous materials, or aqueous solutions of metal salts such as sulfates, chlorides, nitrates, acetates, etc., or metal compound sols composed of at least one of these metals, or metal compound sols are mentioned. It is recommended to apply a metal salt aqueous solution or a metal compound sol.

Particularly, since iron is not a heavy metal, there is no limitation in its use. Therefore, it is recommended to use an aqueous solution of a metal salt such as iron nitrate as the aqueous metal solution.

The amount of the metal or metal compound to be added to the titanium compound (flake) is in the range of about 0.2 to 8% by weight in terms of metal oxide. The mixing of the titanium compound with the metal or the metal compound is not limited to either a dry method or a wet method, but since these mixtures are fired in the presence of a sodium compound in the subsequent firing step, the titanium alcohol is first used.
An organic titanium compound obtained by partially hydrolyzing oxides is dispersed in water, a water-soluble metal salt or a metal compound sol is dissolved or dispersed therein, and then a sodium compound such as sodium hydroxide or sodium carbonate is added. The water-soluble metal salt or metal compound sol is precipitated as a metal hydroxide on the titanium compound and dried as a slurry,
A firing method is recommended.

The sodium compound to be present at the time of firing should be about 0.1% by weight to less than 1.0% by weight as sodium oxide in the titanium oxide compound after firing. Although not limited to the properties of the liquid or the like, for example, when sodium hydroxide is used as the sodium compound, 1 to 20 mol in terms of metal relative to the metal or metal compound mixed with the titanium compound for the purpose of imparting photochromic properties. Used in a range of ratios. In this case, sodium hydroxide may be present in any form of solid or liquid.

The mixture comprising the titanium compound, the metal compound for imparting photochromic properties and the sodium compound prepared by the above-mentioned method and the like is then added to a mixture of about 500 to
Firing at a temperature of about 750C, preferably about 550C to about 700C, for about 1 hour or more. The particulate, plate-like, or flaky titanium compound after calcination is used for various applications as it is or, if necessary, adjusted to a desired shape by neutralization, pulverization, and sieving. Although the shape of the flake obtained in the present invention is not particularly limited, it is usually about 4 μm or less in thickness, preferably about 0.1 μm.
Generally, those having an aspect ratio (size / thickness) of about 5 to about 50 having a size of 1 μm to about 3 μm and a size of about 3 to 200 μm are generally manufactured.

The titanium oxide-based compound thus obtained is obtained by converting a sodium compound consisting essentially of sodium oxide and sodium titanate into sodium oxide in an amount of about 0.1% to less than 1.0% by weight, A metal compound comprising at least one of iron, chromium, copper, nickel, vanadium and manganese is about 0.2 to 8.0% by weight in terms of a metal oxide, and the balance is substantially titanium oxide and partly from sodium titanate. This is a titanium oxide-based compound having photochromic properties and containing the titanium compound so that the titanium compound becomes 100% by weight in terms of titanium oxide.

The reason why the titanium oxide-based compound obtained by the present invention is excellent in photochromic properties is not clear, but generally, the mechanism of the development of photochromism is, first, the existence of lattice defects in titanium oxide crystals. It is said that an oxidation / reduction reaction between the lattice defect and the metal ions doped in the crystal by irradiation of ultraviolet light to low-wavelength visible light causes photochromism. The crystallized titanium oxide used as a raw material in the conventional method has a small number of lattice defects and is unlikely to have metal ions in the vicinity of the lattice defects. And baking it in the presence of a sodium compound, more lattice defects are formed and more metal ions can be present in the vicinity of the defect, so that excellent photochromic properties are expressed. It is supposed to be.

The titanium oxide-based compound obtained according to the present invention can be used after being mixed or diluted with other substances.
The degree of discoloration due to photochromism can be clearly identified 8
It has the above color difference ΔE, and is extremely useful.

[0028]

As described in detail above, according to the present invention, a titanium oxide compound having photochromic properties in the form of particles, plates or flakes can be obtained. The flaky titanium oxide obtained by the present invention, which is one embodiment, has the whiteness and concealing properties of the conventional flaky titanium oxide, the function of laminar arrangement and adhesion of the flakes depending on the shape, as well as the foundation. When applied to natural cosmetics, the drawback of conventional cosmetics that the finished cosmetics in the room are too white under the bright sunshine, but the superior photochromic properties make the cosmetics The color of the skin quickly changes color under the sunlight, and the makeup skin color can be provided in a natural and beautiful appearance even when the makeup skin color is not conspicuous even outdoors. In addition, when used for signboards and displays, it can be applied to various cosmetics, paints, resin fillers, etc. The target value is very large.

[0029]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

The method for evaluating photochromism in the present invention is as follows. A 0.3 g of a particulate, plate-like or flaky titanium oxide compound having photochromism is used as a nitrocellulose lacquer (nitrocellulose concentration: 17%) 2.7.
g) to prepare a coating uniformly dispersed in g, apply this coating uniformly on paper at a thickness of 75 μm, and then dry and store it in a dark place for 12 hours or more to make a state in which photochromism does not appear. Then, the coating film was irradiated with ultraviolet light at an intensity of ² mW / cm ² for 1 hour, and the color before and after the irradiation of the ultraviolet light was measured with a colorimeter to determine the color difference (color difference according to CIELAB color system).
E) was determined.

The quantitative analysis of the metal oxide and sodium oxide in the titanium oxide-based compound obtained in the present invention was measured by an atomic absorption spectrometer Z-8000 manufactured by Hitachi, Ltd.

Example 1 80 kg of toluene, 50 kg of isopropanol, and 50 kg of tetraisopropoxy titanium were placed in a 500-liter SUS tank.
Then, 1.6 kg of water was gradually added dropwise while stirring, and tetraisopropoxytitanium was condensed to a dimer. Then, 6.3 kg of acetic acid was charged and partially acetylated to prepare a stock exfoliating solution.

This undiluted solution was spread on a rotating chrome-plated drum having a diameter of 1 m and a width of 1 m heated to 90 ° C. through a rubber roll. After forming a liquid film, the solvent was removed by evaporation.
Then, partial hydrolysis was caused by contacting with steam. The stock solution changed to a solid state, and as the hydrolysis proceeded, cracks were formed and flakes were formed.

Next, the flakes on the drum were scraped off by a scraping blade, and then the thinning stock solution was spread on the drum surface again to continuously produce flakes. The size and thickness of the obtained flakes are controlled by the spread amount of the liquid and the degree of hydrolysis according to the target.

As a result of composition analysis, the obtained flaky organotitanium compound was hydrolyzed with about 0.4 mol of acetyloxy group and about 0.1 mol of isopropoxy group per 1 mol of titanium. The remaining titanium oxide had a composition of 65% as estimated from the amount of the calcined residue at 700 ° C.

250 kg of the flaky organotitanium compound thus obtained was added to 580 kg of water and 9 kg of ferric nitrate 9
4.2 kg of water salt and 1 m ³ were put into a mixing tank and mixed with stirring, and then 22.5 kg of a 15% aqueous sodium hydroxide solution was added thereto.
Was added dropwise while stirring, and then the slurry was dried as it was with a drum dryer, and further fired at 660 ° C. for 1 hour in an electric furnace. Since excessive sodium hydroxide remains in the obtained flakes, it is dispersed again in water, neutralized, dried, and flake-shaped oxidized with an average size of 5 μm and an average thickness of 0.5 μm. A titanium compound was obtained. The color difference was measured, and as a result, ΔE10.6. Also F
e ₂ O ₃ and Na ₂ O content are 0.9% and 0.1% respectively.
8%.

Examples 2 to 4 Example 2 was repeated except that the addition amount of ferric nitrate nonahydrate was varied as shown in Table 1 and that the photochromic imparting step of the flaky organotitanium compound was performed on a 100 g scale. 1
Flaky titanium oxide was obtained in the same manner as in
The contents of E, Fe ₂ O ₃ and Na ₂ O were measured. Table 1 shows the results.

[0038]

[Table 1]

Examples 5-6 Example 1 was repeated except that the amount of sodium hydroxide added was varied as shown in Table 2 and that the photochromic imparting step of the flaky organotitanium compound was performed on a 100 g scale.
Flaky titanium oxide was obtained in the same manner as in
The contents of E, Fe ₂ O ₃ and Na ₂ O were measured. Table 2 shows the results.

[0040]

[Table 2]

Examples 7 to 10 In the method of Example 1, as a metal compound for imparting photochromic properties, a metal salt shown in Table 4 was fired, and the amount of the metal compound was 0.9% by weight in terms of a metal oxide. Was added so as to be 0.8% by weight in terms of Na ₂ O after calcination to obtain flaky titanium oxide, and ΔE was measured. Table 3 shows the results.

[0042]

[Table 3]

Example 11 n-butanol 160 k in a 500 liter SUS tank
g and 80 kg of tetrabutoxytitanium, 15 kg of acetic acid was charged with stirring, and the mixture was stirred at 70 ° C. for 2 hours to perform partial acetylation to prepare a stock exfoliating solution. 7
Spreading through a rubber roll on a rotating 1.2 m diameter, 1 m width alumina coated drum heated to 0 ° C.
After forming the liquid film, thin sections were continuously produced in the same manner as in Example 1.

As a result of composition analysis, the obtained flaky organic titanium compound was not hydrolyzed by about 0.6 mol of acetyloxy group and about 0.1 mol of n-butyl group per 1 mol of titanium. Was left.

250 kg of the flaky organotitanium compound thus obtained was added to 580 kg of water and 9 kg of ferric nitrate 9
4.2 kg of water salt and 1 m ³ were put into a mixing tank and mixed with stirring, and then 22.5 kg of a 15% aqueous sodium hydroxide solution was added thereto.
Was added dropwise while stirring, and then the slurry was dried as it was with a drum dryer, and further fired at 660 ° C. for 1 hour in an electric furnace. Since excessive sodium hydroxide remains in the obtained flakes, it is dispersed again in water, neutralized, dried, and flake-shaped oxidized with an average size of 5 μm and an average thickness of 0.5 μm. A titanium compound was obtained. The color difference of this product was measured, and the result was ΔE11.5. Also F
e ₂ O ₃ and Na ₂ O content are 0.9% and 0.1% respectively.
8%.

Example 12 Titania sol (C manufactured by Ishihara Sangyo Co., Ltd.) was placed in a 10-liter tank.
3.5 kg of N-S, titania content) was charged, 3.4 kg of water was added dropwise with stirring, and then a solution composed of 51 g of ferric nitrate nonahydrate and 68 g of water was added dropwise to flake. A stock solution was prepared.

This undiluted solution was spread on a rotating alumina spraying drum having a diameter of 50 cm and a width of 20 cm heated to 50 ° C. through a rubber roll to form a liquid film, and then water was removed by evaporation. The liquid film became a solid state, and as the volume shrinkage occurred, the film cracked and flakes were formed.

Next, the flakes on the drum were scraped off by a scraping blade, and thereafter the thinning stock solution was spread on the drum surface again to continuously produce flakes. The size and thickness of the obtained flakes are controlled by the spread amount of the liquid and the degree of the drying speed according to the target.

The thus obtained flakes (1.2 kg) were impregnated with 6 kg of water in which 13.5 g of sodium hydroxide was dissolved, the slurry was dried as it was with a drum dryer, and further fired in an electric furnace at 700 ° C. for 1 hour. did. Since excess sodium hydroxide remains in the obtained flakes, it is dispersed again in water, neutralized by adding an aqueous solution of hydrochloric acid, washed with water, dried and washed with an average size of 5 μm and an average thickness of 5 μm. A flaky titanium oxide compound having a thickness of 0.6 μm was obtained. The color difference of this product was measured, and the result was ΔE12.2. Also F
e ₂ O ₃ and Na ₂ O content are 0.9% and 0.1% respectively.
8%.

Examples 13 to 15 Commercially available titanium oxide and crystallized flaky titanium oxide [Example 13; R-830 (manufactured by Ishihara Sangyo Co., Ltd.), Example 14; P-25 (manufactured by Degussa), Example 15; Flaky titanium oxide (trade name: Luxelen (manufactured by Sumitomo Chemical Co., Ltd.)), and yellow iron oxide was added and mixed so that the amounts of Fe ₂ O ₃ and Na ₂ O shown in Table 4 were obtained. After the application, ΔE was measured. Table 4 shows the results. Further, the titanium compound of Example 1 was calcined at 700 ° C. without adding any sodium compound and iron compound at all to obtain a flaky titanium oxide compound, and ΔE was measured. The results are shown in Table 4 as Example 16.

[0051]

[Table 4]

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C01G 23/00 C09D 5/00 C09K 9/00 CA (STN)

Claims (1)

(57) [Claims] 1. A metal compound comprising at least one of iron, chromium, copper, nickel, vanadium and manganese having a sodium compound content of 0.1 to less than 1.0% by weight in terms of sodium oxide. ~ 8.0% by weight
And a photochromic titanium oxide-based compound (titanium oxide) in which the titanium compound is 100% by weight in total with the two components in terms of titanium oxide.
Is dispersed in deionized water.
Add iron or iron acetate, stir, add sodium hydroxide
To neutralize and react, and then the residue obtained by filtration
Obtained by washing, drying, baking and crushing
) .