JP2964513B2 - High heat resistant high refractive index composite oxide thin film, composition for forming the same, and incandescent lamp - Google Patents

Description

The present invention relates to a high heat resistant high refractive index composite oxide thin film, a composition for forming the same, and an incandescent lamp.

The high heat resistant high refractive index composite oxide thin film of the present invention is a light refractive index thin film of a light interference film composed of a multilayer film in which a low refractive index thin film composed of a transparent metal oxide thin film and a high refractive index thin film are alternately laminated. It is suitably used as a layer.

The light interference film is used as a light reflection film or a light reflection prevention film of a light source lamp, a mirror, a solar heat collecting mirror, an optical filter, a cold mirror, a solar cell or the like.

[Conventional technology]

Titanium oxide with high refractive index and excellent translucency as a high refractive index thin film formed on the heat resistant substrate surface, especially as a high refractive index thin film layer formed on the low refractive index thin film layer of the light interference film (Ti
O ₂ ) thin films are commonly used. Further, the present applicant has proposed a TiO ₂ -GeO ₂ -based composite oxide thin film having high translucency and a high refractive index, which is particularly suitable as a high refractive index thin film layer of an optical interference film (JP-A-62-177501). Reference).

On the other hand, an organic solvent solution of a tetraalkoxytitanium monomer is generally employed as a coating solution for forming these TiO ₂ thin films on the surface of a heat-resistant base material. A solution in which an alkoxytitanium polymer) is dissolved in a mixed organic solvent containing a chelating agent such as acetylacetone (JP-A-54
And the like are also known.

In addition, the applicant of the present invention, as a composition for forming a TiO ₂ thin film as a light refractive index thin film layer of an optical interference film, each of a tetraalkoxytitanium monomer and a tetraalkoxytitanium polymer are reacted with a chelating agent and mixed to form an organic compound. A composition dissolved in a solvent (see JP-A-60-040171),
And an organic solvent solution containing a mixture or reaction product of an organic solvent-soluble titanium compound and a germanium compound as the composition for forming a TiO ₂ -GeO ₂ -based composite oxide thin film (JP-A-62-177502) See).

On the other hand, in recent years, a filament is disposed at the center of a T-shaped or tubular valve, and a visible light transmitting infrared reflecting film is provided on the valve surface. Halogen lamps are known in which the filament is returned to the filament, thereby heating the filament to increase the luminous efficiency and reduce infrared rays in the emitted light.

Such a visible light transmission infrared reflectance is silica (Si
It is obtained by alternately laminating 5 to 7 or more layers of a refractive index layer made of O ₂ ) or the like and a high refractive index layer made of titanium oxide (TiO ₂ ) or the like.

However, in the bulb as described above, or when the output is to be turned or when the instrument large, the bulk temperature reaches a high temperature above 900 ° C., for a long time turned, visible turbidity due to crystallization progress of the TiO ₂ film is generated The transmittance decreases.

[Problems to be solved by the invention]

As described above, a TiO ₂ thin film, a zirconium oxide (ZrO ₂ ) thin film, a tantalum oxide (Ta ₂ O ₅ ) thin film, and a composite oxide thin film thereof are adopted as the high refractive index thin film formed on the heat-resistant substrate surface. However, in an optical interference film in which a low-refractive-index thin film and a high-refractive-index thin film are alternately stacked, the refractive index difference between the low-refractive-index film layer and the high-refractive-index thin film layer is large, and both layers have translucency. A thin film of a material with excellent uniformity and uniform film thickness and excellent adhesion between both layers is required for both layers. In general, a silicon oxide (SiO ₂ ) thin film is used as a low refractive index layer and a high refractive index A TiO ₂ thin film is employed as a layer.

In recent years, with the expansion of applications of the optical interference film, an optical interference film having excellent stability under high-temperature conditions in addition to the above performance has been required.

The organic solvent solution of tetraalkoxytitanium monomer used to form a general TiO ₂ thin film is easily hydrolyzed by the tetraalkoxytitanium monomer itself, absorbs moisture in the atmosphere, easily gels, and is extremely stable. Therefore, it is difficult to apply the method for forming a light interference film.

A composition in which a tetraalkoxytitanium polymer is dissolved in a mixed solvent containing a chelating agent has excellent stability,
And when the TiO ₂ thin film is formed alone on the surface of the heat-resistant substrate, the film is excellent in film formability.
When used to form an O ₂ thin film, the interlayer adhesion with the SiO ₂ thin film as a low refractive index layer is insufficient, and a good light interference film cannot be obtained.

The composition in which each of the tetraalkoxytitanium monomer and the polymer is reacted with a chelating agent and mixed and dissolved in an organic solvent is excellent in stability and film formability of a TiO ₂ thin film,
Also, it has excellent interlayer adhesion with a low refractive index, and is suitable for forming a high refractive index thin film layer of an optical interference film. However, with this composition, one defect-free TiO ₂
The film thickness that can be formed by one application baking is limited to about 800 mm, and when a film thickness larger than that is required, it is necessary to repeat the coating and baking, and the film was formed using this composition
The TiO ₂ thin film has insufficient thermal stability at a high temperature, for example, at a temperature of 900 ° C. or more, and the re-heating after forming the thin film sometimes significantly lowers the visible light transmittance.

On the other hand, the TiO ₂ -GeO ₂ composite oxide thin film has a high refractive index, a large visible light transmittance, and excellent interlayer adhesion with a dissimilar metal oxide thin film. Further improvements were needed.

An object of the present invention is to provide a high refractive index composite oxide thin film having excellent thermal stability and a composition for forming the same.

Another object of the present invention is to provide an incandescent lamp that can avoid a decrease in visible transmittance without a decrease in transmittance of the infrared reflective film even when the lamp is turned on for a long time.

[Means and actions for solving the problem]

(1) High heat resistant high refractive index composite oxide thin film and composition for forming the same The invention of claim 1 is characterized in that the TiO ₂ thin film has an atomic ratio to Ti of 0.005.
≦ (Al + Mg) /Ti≦0.3, including an additive metal composed of Al and Mg contained in the TiO ₂ thin film; and a vitreous forming agent having a metal oxide ratio of 10% by weight or less. It is characterized by the following.

The invention according to claim 2 is characterized in that the organic solvent has an atomic ratio to Ti of 0.005.
An organic solvent-soluble titanium (Ti) compound, an aluminum (Al) compound, a magnesium (Mg) compound, and a reaction product formed between these compounds, such that ≦ (Al + Mg) /Ti≦0.3. With mixture; to metal oxide ratio
And 10% by weight or less of a vitreous forming agent.

The invention according to claim 3 is a valve; a filament disposed in the bulb; an inner conductor electrically connected to the filament; a TiO ₂ thin film, and a Ti atomic ratio to 0.005 ≦ (Al + Mg) / Ti.
Al and Mg contained in the TiO ₂ thin film so that ≦ 0.3
And a high heat resistant high refractive index composite oxide provided on at least one of the inner and outer surfaces of the bulb. And a thin film.

This high heat resistant high refractive index composite oxide thin film has an initial refractive index of 2.15 or more and an initial visible light transmittance of 91.5% in which an anatase type crystal phase of TiO ₂ or a little rutile type crystal phase is mixed in the anatase type crystal phase. It is a thin film having a thickness of 700 to 1500 ° having the above.

The above-mentioned thin film contains a mixture of an organic solvent-soluble titanium compound, an aluminum compound and a magnesium compound and a reaction product therebetween, and further contains a vitreous forming agent. It is obtained by applying an object.

Here, the titanium compound soluble in an organic solvent is, for example, a tetravalent compound represented by the general formula: Ti (OR) ₄ , wherein R is the same or different monovalent hydrocarbon group having 1 to 18 carbon atoms. Titanium alkoxide monomers such as methoxytitanium, tetraethoxytitanium, tetraisopropoxytitanium, tetrabutoxytitanium, diethoxydiisopropoxytitanium, dimethoxydibutoxytitanium, tetra (2-ethylhexoxy) titanium and tetraphenoxytitanium; A hydrolyzed condensate of the monomer (titanium alkoxide polymer) and a mixture of the titanium alkoxide monomer and the titanium alkoxide polymer are used. Further, the titanium alkoxide monomer, the titanium alkoxide polymer and a mixture thereof, an acylating agent such as an organic carboxylic acid such as acetic acid, propionic acid, butyric acid and a higher fatty acid and / or a β-diketone such as acetylacetone and benzoylacetone. , Acetoacetic acid, keto acids such as propionyl butyric acid, lower alkyl esters of keto acids, diols such as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, octylene glycol, glycols, lactic acid, etc. Of oxyacids and lower esters thereof, and a chelating agent capable of forming a chelating ring with a Ti atom such as amino alcohols such as diethanolamine and triethanolamine. Titanium compounds and the like are used.

Examples of the aluminum compound include an aluminum compound soluble in an organic solvent, for example, an aluminum alkoxide monomer having the same substituent as the titanium compound, a hydrolyzed condensate of the aluminum alkoxide monomer (aluminum alkoxide polymer), a mixture thereof, and a mixture thereof. And the acylating agent and / or A
An aluminum compound obtained by reacting an atom with a chelating agent capable of forming a chelating ring is used.

Further, as the magnesium compound, an organic solvent-soluble magnesium compound, for example, a magnesium alkoxide monomer having the same substitution value as the titanium compound, a hydrolyzed condensate of the magnesium alkoxide monomer (magnesium alkoxide polymer) and a mixture thereof, Further, a magnesium compound obtained by reacting them with the above-mentioned acylating agent and / or a chelating agent capable of forming a chelating ring with the Mg atom is used.

The reaction product between the titanium compound and the aluminum compound is a copolymer obtained by hydrolyzing and co-condensing a titanium alkoxide monomer and / or a titanium alkoxide polymer with an aluminum alkoxide monomer and / or an aluminum alkoxide polymer, This copolymer may also be acylated and / or chelated.

The reaction product between the titanium compound, the aluminum compound and the magnesium compound is obtained by hydrolyzing and co-condensing a magnesium alkoxide monomer and / or a magnesium alkoxide polymer during the reaction between the titanium compound and the aluminum compound. And the copolymer may also be acylated and / or chelated.

As the organic solvent, those capable of dissolving the above-mentioned metal compounds are used without any particular limitation. For example, lower alcohols, esters, ketones, aliphatic hydrocarbons,
Aromatic hydrocarbons, halogenated hydrocarbons and mixed solvents thereof are used, and preferably, a single solvent or a mixed solvent having a boiling point of 180 ° C. or lower is used.

The composition for forming a high heat resistant high refractive index composite oxide thin film of the present invention (hereinafter, simply referred to as “coating solution”) has an atomic ratio to Ti of 0.1.
Organic solvent-soluble titanium (Ti) compound, aluminum (Al) prepared so that 005 ≦ (Al + Mg) /Ti≦0.3
Contains 1 to 30% by weight of a compound, a magnesium (Mg) compound, and a reaction product generated between these compounds as a concentration in terms of a metal oxide (Al ₂ O ₃ + MgO ₂ + TiO ₂ ) dissolved in the organic solvent. Solution.

The coating liquid may contain a vitreous forming agent such as an organic solvent-soluble inorganic or organic phosphorus compound, boron compound, antimony compound or the like.

These vitreous forming agents are 1 to the total (Al ₂ O ₃ + MgO ₂ + TiO ₂ ) in which the metal component is converted to oxide on an oxide basis.
0% by weight or less, preferably in the range of 1 to 5% by weight.

The high heat resistant high refractive index composite oxide thin film of the present invention is dried by applying the coating solution to a uniform thickness on a heat resistant substrate, 450
It is formed on the surface of the heat-resistant substrate by thermally decomposing the organic matter by heating at a temperature of not less than ° C for 1 second to 3 hours.

Further, it can also be formed by a method of spraying a coating on the surface of a heat-resistant base material heated to 450 ° C. or higher and thermally decomposing.

As the heat-resistant base material, a base material having a smooth surface without deformation or phase change in a temperature range from room temperature to the maximum firing temperature is used. For example, heat-resistant glass such as quartz glass and borosilicate glass, ceramics such as alumina, and metals such as gold and platinum can be used. In many cases, heat-resistant glass is used.

As a method of applying the coating solution to the heat-resistant substrate, a method capable of forming a uniform film thickness is used without any particular limitation. For example, a dipping and pulling method, a spray method, a spinner method, a roll coating method, a calendar coating method, a doctor blade method, a printing method and the like can be adopted, and particularly when uniformity of the film thickness is required, the dipping and pulling method is preferable. Adopted.

By forming the high heat-resistant high-refractive-index composite oxide thin film and the low-refractive-index metal oxide thin film of the present invention, for example, an SiO ₂ thin film, alternately to a predetermined thickness to form a multilayer film,
An optical interference film can be manufactured.

The SiO ₂ film is formed of an organosilicon compound, for example, silane alkoxides such as tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, diethoxydiisopropoxysilane, dichlorodimethoxysilane, and / or hydrolytic condensation thereof. It can be formed on a heat-resistant base material or a high-heat-resistant high-refractive-index composite oxide thin film by using a solution containing a body and in the same manner as in the formation of the high-heat-resistant high-refractive-index composite oxide thin film.

The high heat resistant high refractive index thin film of the present invention has a
It is based on O ₂ and contains A and Mg.

Generally, by thermally decomposing a titanium compound at a high temperature,
Amorphous TiO ₂ , anatase and / or rutile TiO ₂ crystals are produced. Amorphous TiO ₂ and anatase type TiO ₂ show high visible light transmittance, but have a lower refractive index than rutile type TiO _2, and are also high temperature stable type rutile type TiO ₂ by heating at high temperature for a long time. Phase conversion. The rutile TiO ₂ thin film is thermally stable compared to the anatase TiO ₂ thin film, and shows a high refractive index, but when the amorphous phase and the anatase type crystal phase are phase-converted in the thin film,
The visible light transmittance of the thin film decreases. Therefore, in a system requiring a high refractive index and a high visible light transmittance, for example, a high refractive index film layer of a light interference film, anatase type TiO ₂ and rutile type Ti
Balancing the mixing ratio with O ₂ and rutile TiO ₂
The purpose is achieved by suppressing the phase conversion to.

In the present invention, by containing the A and Mg in TiO _2, results phase transformation and grain growth of the rutile TiO ₂ at a high temperature heating of amorphous TiO ₂ and anatase TiO ₂ is suppressed, the visible A decrease in light transmittance is also suppressed, and a highly heat-resistant composite oxide thin film can be obtained. These effects increase as the contents of A and Mg increase, but when the contents are excessive, the refractive index of the composite oxide thin film decreases. Therefore, their contents are 0.005 ≦ (A + Mg) / Ti as a metal atomic ratio.
It is preferable to set the range of ≦ 0.3.

On the other hand, the vitreous forming agent improves the smoothness and visible light transmittance of the composite oxide thin film. Further, in a low refractive index film, particularly an optical interference film alternately laminated with an essentially amorphous SiO ₂ thin film, the interlayer adhesion between the low refractive index thin film and the high refractive index thin film is improved.

Excessive addition of a vitreous forming agent also lowers the refractive index of the composite oxide thin film.
Total (Al ₂ O ₃ + MgO ₂ + Ti
The content is 10% by weight or less, preferably 1 to 5% by weight based on O ₂ ).

The composition (coating solution) for forming a high heat-resistant high-refractive-index thin film of the present invention is characterized in that it is a homogeneous solution using each of the organic solvent-soluble raw materials.

Since these coating solutions have a uniform composition, by using them, it is possible to form a high-heat-resistant high-refractive-index composite oxide thin film having a uniform composition, that is, having uniform characteristics on a substrate. .

In particular, by using an acylated and / or chelated metal alkoxide raw material as each raw material, not only the hydrolysis stability of the metal alkoxide is improved,
The thickness of the composite oxide thin film that can be formed by one coating and firing is 70
It can be improved from 0 mm or more to the level of 1,500 mm.

(2) Incandescent light bulb The present invention provides a visible light transmitting infrared reflecting film formed by alternately laminating a high refractive index layer and a low refractive index layer on at least one of the inner and outer surfaces of a glass bulb, In the incandescent lamp having a filament disposed therein, the high refractive index layer is an A- and Mg-containing TiO ₂ layer containing a metal having an atomic ratio to Ti of 0.005 ≦ (A + Mg) /Ti≦0.3. Incandescent light bulb.

The present inventors use an A and Mg-containing TiO ₂ layer containing (A and Mg) based on TiO ₂ as the high refractive index layer, so that the incandescent light whose visible transmittance does not decrease even if it is lit for a long time is considered. I got a light bulb.

In the present invention, by using A and Mg-containing TiO ₂ as described above, the refractive index of the anatase or anatase TiO ₂ layer in which some rutile is mixed is 2.15 or more, and the transmittance is 1.
5% or more layers is obtained as a result of phase transformation and grain growth of the rutile TiO ₂ at a high temperature heating of amorphous TiO ₂ and anatase TiO ₂ is suppressed, it is suppressed decrease in visible light transmittance A highly heat-resistant composite oxide layer is obtained. These effects increase as the content of A and Mg increases, but when they are excessive, the refractive index of the composite oxide layer decreases. Therefore, the contents of these metals were adjusted so that the metal atomic ratio, that is, the atomic ratio to Ti, was 0.005 ≦ (Al + Mg) /Ti≦0.3.

In the present invention, the refractive index of the high refractive index layer is 2.0 or more, and the refractive index of the low refractive index layer is 1.6 or less.

Examples of the material of the low refractive index layer include silica (SiO ₂ ) and magnesium fluoride (MgF ₂ ).

〔Example〕

The present invention will be described in more detail with reference to Examples and Comparative Examples.

However, the scope of the present invention is not limited by the following examples.

(1) Preparation of composition for forming composite oxide thin film In a reaction vessel, titanium alkoxide, aluminum alkoxide and ethanol or titanium alkoxide, aluminum alkoxide, magnesium alkoxide and ethanol are uniformly mixed and then acylated while stirring at room temperature. An agent or a chelating agent was added, and the mixture was heated and maintained under reflux for 1 hour to perform a reaction. A vitreous forming agent and ethanol are added to the obtained reaction solution, and a composite oxide having a concentration of 4.5% by weight in terms of a composite oxide (TiO ₂ + Al ₂ O ₃ ) or (TiO ₂ + MgO ₂ + Al ₂ O ₃ ) is added. Composition for forming an object thin film:
A-1 to A-4 were prepared.

In addition, only titanium alkoxide was used as a metal component, and the other components were treated in the same manner as described above. Comparative sample CA-1 was added, and aluminum compound or aluminum compound and magnesium compound were added in excess, and comparative samples CA-2 and CA-2 were added.
-3 was prepared.

 Table 1 shows the specifications of each prepared sample.

 The abbreviations in Table 1 represent fire.

DEG: diethylene glycol AcAc: acetylacetylacetone (2) Formation of composite oxide thin film A well washed and dried 20 mm x 50 mm x 1 mm quartz glass substrate was immersed in each of the samples prepared in the above item (1).
It was pulled up at a constant speed of cm / min and dried at room temperature.

Then, the substrate was placed in an electric furnace maintained at 1,000 ° C for 5 minutes.
The composite oxide film thin film was formed on the surface of the quartz glass substrate by holding and firing for a minute.

(3) Evaluation test of composite oxide thin film The visible light transmittance Tm (%) of the quartz glass substrate on which the composite oxide thin film prepared in the above item (2) was formed was measured using a self-recording spectrophotometer, The refractive index n and the thickness t (Å) of the composite oxide thin film were calculated from the reflectance R (%) calculated from the minimum value of the light transmittance Tm (%).

In addition, a quartz glass substrate with a composite oxide thin film
After reheating to a temperature of 0 ° C. and holding for 1 hour and 500 hours, each characteristic was measured in the same manner as described above.

Table 1 shows the results of these measurements and the state of the thin film after reheating (the presence or absence of cloudiness, pinholes, fine cracks, etc.).

As shown in Table 1, by using the compositions of the second and third inventions, there is no relatively thick defect of about 1,000 mm in one application and baking, A composite oxide thin film having excellent high-temperature thermal stability is formed (see Examples). On the other hand, the oxide thin film containing neither A nor MgA and becomes cloudy due to reheating and lacks high-temperature thermal stability (see Comparative Example).

(5) Production of optical interference film A 20 mm x 50 mm x 1 mm quartz glass substrate, which has been well washed and dried, was used for the samples A-1 and A-3 prepared in the above item (1).
, And pulled up at a constant speed of about 40 cm / min and dried at room temperature.

Then, the substrate was placed in an electric furnace maintained at 1,000 ° C for 5 minutes.
Then, the mixture was baked for 10 minutes to form a composite oxide thin film having a film thickness of 1,100 ° and 1,060 °, a refractive index of 2.28 and 2.28, and a visible light transmittance of 91.7% and 92.6%, respectively, on the surface of the quartz glass substrate.

Then, this substrate was treated with an organic solvent solution containing an organosilicon compound having a concentration of 5.0% by weight in terms of SiO ₂ (main component: silicate polymer, main solvent: acetate, trade name: Atron NSi-500 (Nippon Soda) Co., Ltd.), pulled up, heated in an electric furnace at a temperature of 1,000 ° C. for 10 minutes, and baked to form an SiO ₂ thin film having a thickness of 1,800 mm and a refractive index of 1.46 on the composite oxide thin film.

Further, a quartz glass substrate on which the composite oxide thin film and the SiO ₂ thin film are laminated is immersed in each of the samples, and thereafter, a composite oxide thin film is formed under the same conditions as above,
O ₄ thin film and repeating the formation of the complex oxide thin film, and the five-layer film of the composite oxide / SiO ₂ / composite oxide / SiO ₂ / composite oxide is formed on a quartz glass substrate surface.

The maximum transmittance of visible light of the quartz glass substrate with the five-layered film obtained was 90% or more, and the reflectance in the near-infrared region was high, showing good optical coherence without thin film defects such as cracks and peeling. .

The substrate on which these optical interference films are formed is heated to 900 ° C for 500
Even after reheating for a long time, the maximum transmittance of visible light was 90% or more, and no generation of thin film defects such as cracks and white turbidity was observed.

(6) Manufacture of incandescent lamp An embodiment of the incandescent lamp of the present invention will be described below with reference to FIGS.
This will be described with reference to the drawings.

Reference numeral 1 in the drawing denotes an anchor supporting a Kungsten filament described later. The anchor 1 is provided with a T-shaped valve 3 made of transparent quartz glass via a sealing portion 2. A required halogen gas is sealed in the bulb 3 together with the argon gas. The sealing portion 2 is formed by crush-sealing both ends of the valve 3.
A molybdenum-introduced foil 4 is embedded in the sealing portion 2. The molybdenum-introduced foil 4 is connected to a plurality of inner conductors 5 introduced into the T-shaped bulb 3. A tungsten coil filament 6 located at the center line of the bulb 3 is mounted between the inner conductors 5. A visible light transmitting infrared reflecting film 7 is formed on the outer surface of the bulb 3.

As shown in FIG. 2, the reflective film 7 is formed by alternately laminating high refractive index layers 11 and low refractive index layers 12, and has a property of transmitting visible light and reflecting infrared light. Here, the high refractive index layer 11 is, for example, an A41 based Ti oxide thin film to which A is added, and the low refractive index layer 12 is made of SiO ₂ . In the Ti thin film, the Ti atomic ratio of A is 0.005 ≦ A / Ti ≦ 0.3.

 Next, the reflection film 7 is formed as follows.

First, tetraisoproxytitanium and aluminum acetonate (or diethoxymagnesium) as an organic titanium solution are uniformly mixed in a predetermined amount of ethanol, and diethylene glycol or the like as a chelating agent is added with stirring, and then heated under reflux. Allow the reaction to proceed. Thereafter, the concentration of the obtained reaction solution was calculated as 4.
Adjust to 5%.

Next, after immersing the bulb of the bulb body in this solution,
It is pulled up at a constant speed and baked at 900 ° C for 10 minutes in the air to form titanium oxide.

Next, the concentration of this valve converted to SiO ₂ is 50 wt%.
Organic solvent solution containing an organosilicon compound (main component:
It is dipped in ethyl silicate polymer main solvent ester), pulled up, and heat-treated in the same manner as in the air to form a silicon oxide thin film. This process is alternately repeated ten or more times as desired to form a visible light transmitting infrared reflecting film.

Thus, according to the incandescent current according to the above embodiment, the reflective film 7 alternately includes the high refractive index layer 11 which is an A-based Ti oxide thin film to which A is added and the low refractive index layer 12 made of SiO _2. Because the atomic ratio of A to Ti in the TiO thin film is 0.005 ≦ A / Ti ≦ 0.3 in the TiO thin film, the transmittance of the TiO ₂ film is higher than that of a conventional incandescent lamp even when it is operated at a high temperature for a long time. A high luminous flux could be maintained without reduction, and no cracks, peeling, etc. occurred in the reflection film 7, and the film state was good.

In fact, A-based oxidation with 0.02 addition of Al to Ti atom
Incandescent lamp with Ti thin film as photorefractive index layer 11 (Example 5), A
An incandescent lamp (Example 6) in which an A-based Ti oxide thin film in which 0.03 and 0.01 were added to Mg atoms and Ti atoms, respectively, was used as a high refractive index layer 11;
When the initial optical characteristics of the incandescent current (conventional example) in which a Ti oxide thin film to which A and Mg were not added were used as the high refractive index layer 11 were examined, the TiO ₂ film showed a transmittance of 91.5% or more and a refractive index of 91.5% or more. The result was 2.11 for the conventional product, 2.28 for Example 5, and 2.28 for Example 6, and the results shown in Table 2 below were obtained.

FIG. 3 shows a change in luminous flux when the lamp was subjected to an in-apparatus lighting test. Since the bulb temperature is around 950 ° C., the luminous flux sharply drops in the conventional one. In contrast,
In each of Examples 5 and 6, the luminous flux maintenance ratio was maintained at 90% or more at the rated time of 2000 hours, which was favorable. Also, no cracks, peeling, etc. occurred in the reflection film.

〔The invention's effect〕

The present invention is a composition comprising a composite oxide thin film having a high heat resistance and a high refractive index comprising A and Mg-containing TiO ₂ as described above, and a uniform solution for forming them on a heat resistant substrate. It is characterized by the following.

The A and Mg-containing TiO ₂ thin film of the present invention is a composite oxide thin film having a high refractive index and a high visible light transmittance excellent in high-temperature thermal stability, and is particularly suitable as a high refractive index film layer of a light interference film. is there.

Further, according to the present invention, it is possible to provide an incandescent lamp capable of avoiding a decrease in the luminous flux without a decrease in the transmittance of the infrared reflection film even when the lamp is turned on for a long time.

[Brief description of the drawings]

FIG. 1 is an explanatory view of an incandescent lamp according to one embodiment of the present invention, FIG. 2 is a partial cross-sectional view of a reflection film of the incandescent lamp, and FIG. FIG. 4 is a characteristic diagram showing a relationship between the time and a change with time. DESCRIPTION OF SYMBOLS 1 ... Anchor 2 ... Sealed part 3 ... Quartz glass bulb 4 ... Molybdenum introduction foil 5 ... Inner wire 6 ... Tungsten coil filament 7 ... Visible light transmitting infrared reflecting film 11 …… Low refractive index layer, 12… High refractive index layer.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Naomichi Takasaka 12-54 Goi-minamikaigan, Ichihara-shi, Chiba Prefecture Nippon Soda Co., Ltd. 54 Nippon Soda Co., Ltd. Functional Products Research Laboratory (72) Inventor Atsushi Mori 12-54 Goi South Coast, Ichihara City, Chiba Prefecture Nippon Soda Co., Ltd. Functional Products Research Laboratory (56) References JP-A-62-177501 (JP, A) JP-A-62-177502 (JP, A) JP-A-1-201023 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G01G 23/00 G02B 5/26 G02B 5 / 28 H01K 1/32 CAS on-line

Claims (3)

(57) [Claims] 1. An TiO ₂ thin film; an additive metal composed of Al and Mg contained in the TiO ₂ thin film such that an atomic ratio to Ti satisfies 0.005 ≦ (Al + Mg) /Ti≦0.3; And a vitreous forming agent having a material ratio of 10% by weight or less. 2. An organic solvent; an organic solvent-soluble titanium (Ti) compound, an aluminum (Al) compound, a magnesium (Mg) compound, and an organic solvent-soluble so that the atomic ratio to Ti is 0.005 ≦ (Al + Mg) /Ti≦0.3. A mixture comprising a reaction product produced between these compounds; and a vitreous forming agent having a metal oxide ratio of 10% by weight or less; A composition for forming an object thin film. 3. A bulb; a filament disposed in the bulb; an inner conductor electrically connected to the filament; a TiO ₂ thin film, with an atomic ratio to Ti of 0.005 ≦ (Al + Mg) /Ti≦0.3. And at least one surface of the inside and outside of the bulb, comprising an additive metal composed of Al and Mg contained in the TiO ₂ thin film and a vitreous forming agent having a metal oxide ratio of 10% by weight or less. And a high heat resistant and high refractive index composite oxide thin film provided in the incandescent lamp.