JPH0551209A - Photochromic titanium oxide compound and its production - Google Patents

Abstract

PURPOSE:To obtain a photochromic titanium oxide compd. by adding a specified metal or metal compd. to titanium oxide and firing them in the presence of sodium oxide. CONSTITUTION:An org. titanium compd. such as titanium alkoxide or a titanium compd. such as a titania sol is dissolved in an org. solvent, water, etc., and a substrate is coated with the resulting soln. in a desired thickness to form a thin film. After the solvent is evaporated, partial hydrolysis is carried out by contact with steam to form thin chips of a (org.) titanium compd. and 0.2-8.0wt.% (expressed in terms of metal oxides) metal compds. of one or more among Si, Zn, Al, Ce, Co, Nb and Zr for imparting photochromism and 0.1-7.0wt.% (expressed in terms of sodium oxide) sodium compd. are added to 85.0-99.7wt.% of the thin chips. They are fired at 500-750 deg.C to obtain a photochromic titanium oxide compd.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a coating material having a color rendering effect called photochromic property, printing, resin coloring, cosmetics,
The present invention relates to a titanium oxide compound suitable for fields such as optical memories and a method for producing the same.

[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 used. As chemical substances that exhibit photochromism, silver halides and spiropyran organic compounds are already known. Titanium oxide is known to exhibit photochromism in the presence of metals such as iron, chromium and manganese, and is disclosed in, for example, JP-A-63-132811 and International Publication WO
It is disclosed in O-89 / 12084.

However, as disclosed in the above patent, the metal powder itself which imparts photochromic properties to titanium oxide or its metal salts such as sulfates, chlorides, nitrates and acetates, oxides and hydroxides are simply used. The degree of photochromism that develops is weak only by mixing and baking, and in fact, such a change in chromaticity dilutes the effect when used in combination with other constituents in various applications. Therefore, it was difficult to recognize the change in color tone, and the utility value was low from a practical viewpoint. On the other hand, when the degree of blackening is increased, the color fading property deteriorates, and it is difficult to recognize a substantial change in color tone, and there is a problem in practical use.

[0004]

In view of the above circumstances, the inventors of the present invention have made earnest studies to obtain titanium oxide having photochromic properties that can be applied to a practical level, and as a result, a metal that imparts a specific amount of photochromic properties to titanium oxide. Alternatively, they have found that a titanium oxide-based compound satisfying the above-mentioned characteristics can be obtained when a specific amount of sodium oxide is present in the metal compound, thus completing the present invention.

[0005]

That is, according to the present invention, the titanium compound is 85.0 to 99.7% by weight in terms of titanium oxide, and the sodium compound is 0.1 to 9 in terms of sodium oxide.
A metal compound of 7.0% by weight and at least one of silicon, zinc, aluminum, cerium, cobalt, niobium and zirconium is converted into a metal oxide in an amount of 0.2 to 8.
A titanium oxide compound having a photochromic content of 0% by weight is provided.

Further, the present invention is characterized in that the organotitanium compound is mixed with a metal or a metal compound comprising at least one of silicon, zinc, aluminum, cerium, cobalt, niobium and zirconium, and the mixture is fired in the presence of a sodium compound. Another object of the present invention is to provide a method for producing a titanium oxide compound having photochromic properties.

Further, the present invention relates to titania sol containing silicon,
Provided is a method for producing a titanium oxide compound having photochromic properties, which comprises mixing a metal or a metal compound composed of at least one of zinc, aluminum, cerium, cobalt, niobium and zirconium and firing the mixture in the presence of a sodium compound. To do.

The present invention will be described in more detail below. The titanium oxide-based compound of the present invention comprises a titanium compound in an amount of 85.0 to 99.7% by weight in terms of titanium oxide, a sodium compound in an amount of 0.1 to 7.0% by weight in terms of sodium oxide, and silicon,
A metal compound containing at least one of zinc, aluminum, cerium, cobalt, niobium, and zirconium is contained in an amount of 0.2 to 8.0% by weight in terms of metal oxide. When the above metal compounds such as silicon and zinc in the titanium oxide-based compound are less than 0.2% by weight in terms of metal oxide, the photochromic property is poorly expressed. There is no corresponding effect of exhibiting photochromic properties, the coloring due to the color of the added metal itself becomes large, and the degree of discoloration due to photochromism becomes relatively small. When the amount of sodium oxide is less than 0.1% by weight, the photochromic property is poorly expressed, while the amount of sodium oxide is 7.
If the amount exceeds 0% by weight, the titanium oxide compound obtained is alkaline and the use thereof is restricted.

In the present invention, the titanium oxide compound having the above composition is not particularly limited in its shape, and is produced and used in a shape such as a particle shape, a plate shape or a flaky shape for each application. For example, particulate materials are used in the fields of paints, printing, resin coloring, etc., while plate-shaped or flaky materials are used in the field of rust-preventive coatings that utilize the function of blocking the transmission of oxygen and water, light reflection and It is suitable for paints using pearlescent pigments that take advantage of the interference function, resin coloring and printing fields, as well as cosmetics fields that utilize the functions of adhesion and spreadability of flakes.

Further, the color rendering effect called photochromic property is such 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, while it is suitable for fields such as sensors and optical memories when the degree of blackening is high and the fading property is poor. Therefore, the best photochromic property and shape for each application may be selected and applied. The method for producing the titanium oxide-based compound of the present invention will be described in detail below. The particulate matter is a mixture of the above composition dried (including stationary drying, drum drying, spray drying, etc.), firing,
If necessary, a known production method such as pulverization can be easily considered, and therefore, an example of producing a plate-shaped or flaky titanium oxide-based compound will be given here.

In carrying out the method 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 and OR represents an alkoxy group, x = L + m + n, x and m are> 0 to <2
, And l and n are positive numbers including 0 from 0 to <2)
OX is approximately 0.3 per 1 mol of TiO _2.
.About.0.6 mol, and an organic titanium compound having an OR of about 0.05 to 0.15 mol, which can be used by a known method disclosed in JP-A-60-176906.

For example, titanium alkoxides, especially partially acyloxylated titanium alkoxides, alone or after being diluted with an organic solvent, are coated on a supporting substrate to a desired thickness to form a liquid thin film, and then in the liquid. After further evaporating the solvent, the organic titanium compound is partially hydrolyzed by bringing it into contact with water vapor to form a thin piece of the organic titanium compound, and the thin piece can be scraped by an appropriate scraping operation.

The titanium alkoxides used for forming flakes are alkoxides with alcohols having 1 to 17 carbon atoms, particularly industrially tetra-i-propoxytitanium, tetra-n-butoxytitanium and tetrakis (2-ethylhexoxy). ) Titanium, tetrastearoxytitanium and the like are commercially available, and among them, tetra-i-propoxytitanium is preferable from the economical aspect. In addition, these alkoxides can be hydrolyzed in advance and used in the state of trimer, tetramer, oligomer or 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 thin piece, and the smoothness of the thin piece.

The organic solvent used for forming the liquid film may be any one which can dissolve the above-mentioned titanium alkoxides or partially acyloxylated titanium alkoxides, but from the viewpoint of workability and evaporation removal in forming the liquid film. 7
A solvent having a boiling point range of about 0 to 150 ° C. is preferable. 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, it is advantageous that the recovered solvent need not be separated and purified.

The supporting substrate for forming the film may be a flat plate, but a drum flaker or a belt-shaped endless plate is used for continuous production on an industrial scale. The material of the substrate 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, it is not unambiguous due to the peelability of the thin film formed, the peeling means, and the physical properties of the raw materials used, but in general, if the importance is attached to the metal drum, chemical resistance, and wear resistance, alumina Thermal spray drums are preferred.

The liquid film formed on the base material is subjected to heat treatment to evaporate and remove the solvent from the liquid film. The solvent may be removed from the liquid film by evaporation by heating the support substrate from the inside, blowing hot air onto the surface of the liquid film, or a combination of these, but excessive heating causes boiling of the solvent to form flakes. Therefore, the heating is below the boiling point of the solvent composition constituting the liquid film,
In the case of using warm air, it is preferable to obtain a thin piece having a uniform thickness, which is performed in an amount that does not impair the smoothness of the liquid film surface due to the blowing air amount.

The liquid film on the supporting substrate after the solvent is removed by heating is
Then, it is forcibly hydrolyzed by humidified air such as steam to form a solid film on the supporting substrate. With the progress of hydrolysis, the formed solid film shrinks in volume and cracks in the thin film, resulting in thinning. As a method for peeling the flaky material formed on the supporting base material from the base material, a method of mechanically scraping with a scraper or the like is usually adopted, but peeling by blowing air or water or ultrasonic vibration is used. And the method of peeling by bending the substrate when the substrate is flexible.

In carrying out the method of the present invention, titania sol can be used as a titanium oxide raw material. The titania sol is not particularly limited as long as it is a known one generally used in the production of a thin film, but it is not particularly limited in workability during liquid film formation or economical volatilization dispersion medium amount in drying of the formed liquid film. From the point, the solid concentration is generally 5-4.
0% by weight, preferably 10-30% by weight, of aqueous sol is used. The method for producing flakes using the titania sol can be obtained according to the method for producing flakes using the above-mentioned titanium alkoxide as a raw material.

The photochromic metal or metal compound used in the present invention includes silicon, zinc,
Aluminum, cerium, cobalt, a metal or metal compound consisting of at least one of niobium and zirconium, more specifically silicon, zinc, aluminum, cerium, cobalt, niobium and zirconium metal powder, oxides of these metals, Examples include hydroxides or amorphous materials, or aqueous solutions of metal salts such as sulfates, chlorides, nitrates, and acetates composed of at least one of these metals, or metal compound sols, but uniform mixing with titanium compounds is easy. Therefore, application of an aqueous solution of a metal salt or a sol of a metal compound is recommended.

In particular, zinc and aluminum are not heavy metals and therefore are not limited in use. Therefore, it is recommended to use an aqueous metal salt solution such as zinc nitrate or aluminum nitrate as the aqueous metal solution. Further, as the metal compound, an aqueous commercial sol is used, and in the silica sol, a. Eye. DuPont (E.
I. DuPont) product name Ludox HS-40,
Alumina sol is available under the trade name of Cataloid-A manufactured by Catalysts & Chemicals Industries Co., Ltd. These are not limited to these products, but may be those that are uniformly dispersed in water. These metals or metal compounds are conventionally known iron, chromium, manganese,
Compared to copper, etc., it has excellent color fading properties, resulting in a large change in color tone and extremely high practical value.

The content of these metals or metal compounds in the titanium compound (flake form) is in the range of about 0.2 to 8% by weight in terms of metal oxide. The mixing of the titanium compound and the metal or the metal compound is not limited to either dry type or wet type, but since these mixtures are fired in the presence of the sodium compound in the subsequent firing process, the titanium compound is first dispersed in water and A water-soluble metal salt or metal compound sol is dissolved or dispersed, and then a sodium compound such as sodium hydroxide or sodium carbonate is added to deposit the water-soluble metal salt or metal compound sol on the titanium compound as a metal hydroxide. A method of drying and firing the slurry as it is is recommended.

The sodium compound which is present during firing should be about 0.1% to about 7.0% by weight as sodium oxide in the titanium oxide compound after firing, and in particular, the type, shape, solid, It is not limited to the properties of the liquid, but when sodium hydroxide is applied as the sodium compound, for example, 1 to 20 moles 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 either solid or liquid form.

A mixture of the titanium compound prepared by the above method and the like, the metal compound imparting the photochromic property and the sodium compound is then about 500 to
Baking is performed at a temperature of about 750 ° C., preferably about 550 to about 700 ° C. for about 1 hour or more. The particulate, plate-shaped, or flaky titanium compound after firing is used for various purposes as it is or after being subjected to neutralization treatment, pulverization, and sieving as necessary to obtain a desired shape. The shape of the flakes obtained in the present invention is not particularly limited, but usually the thickness is about 4 μm or less, preferably about 0.
Generally, those having a size of about 1 to about 3 μm, a size of about 3 to 200 μm, and an aspect ratio (size / thickness) of about 5 to about 50 are manufactured.

The titanium oxide compound thus obtained is substantially titanium oxide, and a titanium compound which is partly composed of sodium titanate is converted into titanium oxide in an amount of about 8%.
5.0-99.7% by weight, about 0.1-7.0% by weight of a sodium compound consisting essentially of sodium oxide and sodium titanate in terms of sodium oxide, and silicon,
A titanium oxide compound having photochromic properties, which contains a metal compound containing at least one of zinc, aluminum, cerium, cobalt, niobium, and zirconium in an amount of about 0.2 to 8.0% by weight in terms of metal oxide.

The reason why the titanium oxide compound obtained by the present invention is excellent in photochromic property is not clear, but generally, the mechanism of photochromism expression is that the existence of lattice defects in the titanium oxide crystal is essential. It is said that the oxidation / reduction reaction between the lattice defect and the metal ion doped in the crystal due to irradiation with ultraviolet rays to low wavelength visible light causes photochromism. Crystallized titanium oxide used as a raw material in the conventional method originally has few lattice defects, and metal ions are unlikely to exist in the vicinity of the lattice defects. When mixed with and baked in the presence of a sodium compound, more lattice defects are formed, and many metal ions may be present in the vicinity of the defect portion, so that excellent photochromic properties are expressed. It is supposed to be one.

The titanium oxide compound obtained according to the present invention may be used by mixing or diluting with other substances,
Can clearly identify the degree of discoloration caused by photochromism 8
It has the above color difference ΔE and is extremely useful.

[0028]

As described in detail above, according to the method of the present invention,
It is possible to obtain a particulate, plate-shaped or flaky titanium oxide compound having photochromic properties. The flaky titanium oxide obtained in the present invention, which is an embodiment, has the function of the whiteness and hiding property of the conventional flaky titanium oxide, the layered arrangement of the flakes depending on the shape, and the adhesiveness, as well as the foundation. When applied to various cosmetics, the disadvantage of conventional cosmetics is that the makeup finished in the room is too white in bright sunlight, but its excellent photochromic properties make it possible to match the makeup skin in the room. This makes it possible to provide a make-up cosmetic that looks and looks natural and beautiful because the white color of the product quickly changes its color under sunlight and the whiteness of the color of the makeup skin is not noticeable even outdoors. Also, when used for signboards, displays, etc., it can be applied to various cosmetics, paints, resin fillers, etc., in order to produce a white color that is harmonious with the surroundings, depending on the lighting. The target value is enormous.

[0029]

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

The photochromism evaluation method in the present invention is carried out by using 0.3 g of a particle-shaped, plate-shaped or flaky titanium oxide compound having photochromism as a nitrocellulose lacquer (nitrocellulose concentration 17%) 2.7.
A coating material uniformly dispersed in g was prepared, and the coating material was applied evenly on a paper in a thickness of 75 μm, dried, and stored in a dark place for 12 hours or more so that photochromism was not exhibited. Then, this coating film is irradiated with ultraviolet rays at an intensity of ² mW / cm ² for 1 hour, and the color before and after the irradiation with ultraviolet rays is measured with a colorimeter to obtain a color difference (color difference Δ according to the CIELAB color system).
E) was sought.

Quantitative analysis of metal oxides and sodium oxide in the titanium oxide compound obtained in the present invention was carried out by an atomic absorption measuring device Z-8000 manufactured by Hitachi Ltd.

Example 1 A 500-liter SUS tank was charged with 80 kg of toluene, 50 kg of isopropyl alcohol, and 50 kg of tetraisopropoxide, and 1.6 kg of water was gradually added dropwise with stirring to condense tetraisopropoxide to dimers. Then acetic acid 6.
Partial acetylation was carried out by charging 3 kg to prepare a thin section stock solution. This stock solution was heated and maintained at 90 ° C. and spread on a rotating chrome-plated drum having a diameter of 1 m and a width of 1 m through a rubber roll to form a liquid film, and then the solvent was removed by evaporation, and then steam was brought into contact. This caused partial hydrolysis. (The liquid film changed to a solid state and cracks and flakes were formed as the hydrolysis proceeded.)

Next, the flakes on the drum were scraped off, and then the flaking stock solution was spread again on the surface of the drum to continuously produce flakes. (The size and thickness of the flakes are controlled by the spread amount of the liquid and the degree of hydrolysis according to the target.) The obtained flaky organotitanium compound was analyzed by composition and as a result, 1 mol of titanium was mixed with acetyl. About 0.4 mol of oxy groups and about 0.1 mol of isopropoxy groups remained without being hydrolyzed, and the composition of titanium oxide was 57% when estimated from the baking residue at 700 ° C.

250 g of the flaky organotitanium compound thus obtained was added to 525 kg of water and 2.5 kg of silica sol (Ludox HS-40) in a mixing tank of 1 m ^{3 and the} mixture was stirred and mixed with a 15% caustic soda solution. 38 kg
Was dripped with stirring, then this slurry was dried as it was with a drum dryer and further calcined in an electric furnace at 670 ° C. for 1 hour. Since the obtained flakes had excess alkali remaining, they were dispersed again in water, neutralized, and dried to obtain flaky titanium oxide having an average thickness of 0.6 μm and an average size of 6 μm. When the color difference of this product was measured,
It was E13.1. The SiO ₂ and Na ₂ O contents were 0.7% by weight and 1.3% by weight, respectively.

Examples 2 to 5 The addition amount (unit: g) of silica sol was varied as shown in Table 1, and the step of imparting the photochromic property of the flaky organotitanium compound was carried out on a scale of 100 g (in Examples 3 to 5, 15% caustic soda was used). Flake titanium oxide was obtained in the same manner as in Example 1 except that the amount of the aqueous solution used was 15.2 g), and the ΔE, SiO ₂ and Na ₂ O contents of this were measured. The results are shown in Table 1.

[0036]

[Table 1]

Examples 6 to 8 Thin flakes were prepared in the same manner as in Example 1 except that the addition amount of caustic soda was varied as shown in Table 2 and the photochromic property imparting step of the flaky organotitanium compound was carried out on a scale of 100 g. -Like titanium oxide was obtained, and the contents of ΔE, SiO ₂ and Na ₂ O were measured. The results are shown in Table 2.

[0038]

[Table 2]

Examples 9 to 14 Flake titanium oxide was prepared in the same manner as in Example 1 except that the firing temperature was changed as shown in Table 3 and the step of imparting the photochromic property of the flaky organotitanium compound was carried out on a scale of 100 g. Was obtained, and the ΔE of this product was measured. The results are shown in Table 3.
Shown in.

[0040]

[Table 3]

Examples 15 to 19 The compounding amount of metal or metal compound with respect to the flakes is 0.7% by weight with respect to titanium oxide, and the kind of metal is as shown in Table 4 (in the examples, silicon is Ludox HS-40, aluminum is used). Is aluminum nitrate nonahydrate (manufactured by Wako Pure Chemical Industries),
Zinc nitrate hexahydrate (manufactured by Wako Pure Chemical Industries, Ltd.), iron changed to ferric sulfate nonahydrate (manufactured by Wako Pure Chemical Industries, Ltd.), copper used copper nitrate trihydrate, and flaky organic titanium compounds. Flake titanium oxide was obtained in the same manner as in Example 1 except that the photochromic property imparting step was performed on a scale of 100 g, and ΔE of this was measured. The results are shown in Table 4.

[0042]

[Table 4] * Discoloration rate: Shows the recovery rate after 10 minutes in the dark for the color difference before and after UV irradiation for 1 hour. In addition, A,
B shows a reference example.

Examples 20 to 25 Commercially available titanium oxide and crystallized flaky titanium oxide (the flaky organotitanium compound obtained in Example 1 was used as 660).
The iron compound shown in Table 5 was mixed with (calcined at 1 ° C. for 1 hour) and baked to impart photochromism, and then ΔE of this was measured. The results are shown in Table 5.

[0044]

[Table 5] * In the column of titanium oxide in the table, R-830 is manufactured by Ishihara Sangyo Kaisha, A-1 is manufactured by Bayer, P-25 is manufactured by Degussa, and flaky means flaky titanium oxide.

Continuation of front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display area // C09K 9/00 D 8930-4H

Claims (7)

[Claims] 1. A titanium compound is 8 in terms of titanium oxide.
5.0 to 99.7% by weight, 0.1 to 7.0% by weight of sodium compound in terms of sodium oxide and silicon, zinc,
A titanium oxide compound having photochromic properties, which comprises a metal compound containing at least one of aluminum, cerium, cobalt, niobium, and zirconium in an amount of 0.2 to 8.0% by weight in terms of metal oxide. 2. A photochromic property characterized by mixing a titania sol with a metal or a metal compound comprising at least one of silicon, zinc, aluminum, cerium, cobalt, niobium and zirconium, and firing the mixture in the presence of a sodium compound. Method for producing titanium oxide compound. 3. A photochromic property characterized by mixing an organotitanium compound with a metal or a metal compound comprising at least one of silicon, zinc, aluminum, cerium, cobalt, niobium and zirconium, and calcining in the presence of a sodium compound. A method for producing a titanium oxide-based compound having: 4. The method for producing a titanium oxide compound having photochromic properties according to claim 3, wherein the organic titanium compound is produced from a titanium alkoxide having an acyloxy group. 5. A metal or metal compound comprising at least one of silicon, zinc, aluminum, cerium, cobalt, niobium and zirconium is a water-soluble metal salt or a metal compound sol. 3. The method for producing a titanium oxide compound having photochromic properties according to 3. 6. The method for producing a titanium oxide compound having photochromic properties according to claim 2, wherein the firing temperature is 500 to 750 ° C. 7. The method for producing a titanium oxide compound having photochromic properties according to claim 2, wherein the sodium compound is sodium hydroxide.