JP3186788B2 - Method for producing titanium suboxide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing titanium suboxide used as a colored pigment, a conductive filler, a vapor deposition material and the like, and more particularly to a method for producing titanium suboxide suitable as a vapor deposition material.

[0002]

2. Description of the Related Art Unlike titanium dioxide, titanium suboxide produces various colors such as brown, gray, black-purple or black by a reduction reaction, and has good conductive properties. It is widely used as a conductive filler, but has recently been used as a vapor deposition material for forming a titanium dioxide thin film on a substrate surface in fields such as optical systems and optoelectronics.

Conventionally, means for producing titanium suboxide include:
High temperature return of titanium dioxide with hydrogen or ammonia gas
(JP-B-59-50604, JP-A-57-2053)
No. 22), a mixture of titanium dioxide and metallic titanium is evacuated
Heating in an atmosphere or in a reducing atmosphere (Japanese Patent Laid-Open No. 49-5432)
Is known as a typical technique. these
The method depends on the raw material composition of the solid-gas system or solid-solid system.
And the resulting titanium suboxide is
Generally, TiO, Ti_TwoO_Three, Ti_ThreeO_Five, Ti _FourO₇,
Ti_FiveO₉, And all are sintered bodies.

[0004] coating of titanium dioxide with nitrous oxide titanium deposition material, resistance heating, are formed by a method of vacuum deposition on a substrate surface after dissolved in an electron beam heating or the like, this time, said TiO and Ti ₂ O ₃ causes gas absorption and Ti
On the contrary, ₄ O ₇ and Ti ₅ O ₉ cause a gas generating action and cannot keep the atmosphere in the vacuum chamber constant. In that respect, Ti ₃ O ₅ is extremely stable under reduced pressure and high temperature atmosphere, but the titanium suboxide sintered body represented by Ti ₃ O ₅ manufactured by the above-mentioned conventional technique (hereinafter simply referred to as titanium suboxide). ) Is a vapor deposition material, splash phenomena in a vacuum heating state occur remarkably frequently. When a large number of splash phenomena occur, not only uniform deposition on the substrate surface is hindered, but also troubles such as deposition of deposits on the deposition apparatus and oxidation deterioration of the electron gun filament are caused. To avoid this phenomenon,
It is possible to perform the filming operation after the splash has subsided, but in this case, time loss is increased.
Therefore, it is said that the requirements for the titanium dioxide-forming thin film material are those which do not generate gas or absorb gas, do not cause a splash phenomenon, and have few impurities.

[0005] As a method for producing titanium suboxide effective to solve such a problem, a mixture of titanium hydride powder having a particle size of 80 µm or less and titanium dioxide is formed into pellets, and a temperature range of 700 to 1600 ° C. Has been developed by the present applicant (JP-A-1-290529).

[0006]

According to the prior art,
Splashes and outgassing are significantly reduced compared to the conventional technology because the manufactured titanium suboxide has a particle state suitable for vapor deposition and the content of gas components and impurities is effectively reduced. It is possible to do.
However, the titanium suboxide obtained by this method has few impurities and no gas generation, but its effect of preventing the splash phenomenon is not sufficient.

[0007] The present invention is directed to a method for producing titanium suboxide for a vapor deposition material by a process completely different from the conventional production technology of reducing and sintering titanium dioxide to obtain titanium suboxide. It is an object of the present invention to provide a method for producing titanium oxide for vapor deposition, which can effectively reduce a splash phenomenon in a vacuum heating stage during vapor deposition.

[0008]

Method for producing <br/> titanium suboxides having a composition of Ti ₃ O ₅ for vapor deposition material A in order to achieve the means] in order to achieve the above object according to the present invention, a titanium dioxide, titanium metal Powder and / or titanium hydride powder in weight ratio
A constitutional feature is that a powdery mixture obtained by mixing at a ratio of 8 to 9: 1 is obtained by melting by a non-consumable arc melting method in an inert gas atmosphere under a pressure of atmospheric pressure. Is what you do.

The titanium dioxide as a raw material of the present invention may be produced by any of a sulfuric acid method and a chlorine method.
The crystal type may be any of anatase type, rutile type and brookite type. Although the titanium dioxide is used as a powder, its particle size is not particularly limited. However, it is preferable that the purity as titanium dioxide is as high as possible. Titanium metal and / or titanium hydride, which is the other raw material used in common with titanium dioxide, is also used as a powder, and a commercially available metal powder can be usually appropriately selected and used.

The above-mentioned raw material is made into a powdery mixture by mixing titanium dioxide, titanium metal powder and / or titanium hydride powder, and the powdery mixture is directly charged into a mold and subjected to a non-consumable arc melting step. Can be
When mixing the titanium metal powder and / or the titanium hydride powder with the titanium dioxide powder, the mixing ratio is set in a range of 1: 8 to 9 by weight and mixed by a dry or wet method.

In the melting step, the raw material powder mixture is transferred to a non-consumable arc melting furnace maintained in an atmosphere of an inert gas such as argon or helium, filled in a water-cooled hearth in the furnace, and then applied with a predetermined voltage. It is done by doing. Suitable melting conditions are such that the atmosphere in the furnace is maintained in a pressurized state capable of preventing convection with the atmosphere by argon, and the current and voltage to be applied are set in appropriate ranges according to the ratio of the amounts of the raw materials. This is performed by consumable arc melting.

After melting, the furnace is cooled in an inert gas atmosphere.
The produced titanium suboxide having the composition of Ti ₃ O ₅ is taken out as a product.

[0013]

According to the present invention, there is provided titanium dioxide as a raw material,
Metal titanium powder and / or titanium hydride powder ,
The powdery mixture obtained by mixing at a ratio of 8 to 9: 1 by weight is simply melted by non-consumable arc melting under an inert gas atmosphere under a pressure of atmospheric pressure.
In a short time of about 0 minutes, the titanium oxide is converted into a low-oxidation titanium oxide mainly composed of Ti ₃ O ₅ . At this time, since the dissolving step is performed in a pressurized state that can prevent convection with an inert gas such as argon and the dissolution is completed in a short time, contamination by the air is removed, and high-purity Ti ₃ O ₅ composition
Titanium suboxide having be efficiently produced.

Through such an action, high-quality Ti ₃ O which does not cause a splash phenomenon in a vacuum heating stage during vapor deposition.
It becomes possible to produce titanium suboxide having the composition of ₅ .

[0015]

Hereinafter, examples of the present invention will be described in comparison with comparative examples. Example 1 A titanium powder was mixed with a titanium dioxide powder having a particle size of 45 μm or less at a weight ratio of 1: 9, and mixed with a dry mixer for 12 hours to obtain a powdery mixture. Next, 90 g of the powdery mixture was charged into a copper water-cooled hearth of a non-consumable arc furnace, and the inside of the furnace was completely replaced with argon gas.
Arc melting was performed by applying 400 A and a voltage of 25 V for 10 minutes, and then the furnace was cooled while maintaining the atmosphere in the furnace.

The obtained product was measured by a powder X-ray diffraction method. As a result, it was confirmed that the chemical composition was Ti ₃ O ₅ . When this titanium suboxide sample was melted in an EB melting furnace and the state of splash under vacuum was observed, no splash phenomenon was observed.

Example 2 An experiment was conducted in the same manner as in Example 1 except that the amount of the powdery mixture was changed to 150 g. As a result, the same results as in Example 1 were obtained.

Example 3 Ti ₃ O ₅ was prepared in the same manner as in Example 1 except that titanium hydride powder was used in place of the metal titanium powder, 140 g of the powdery mixture was filled, and a current of 400 A and a voltage of 30 V were applied. A titanium suboxide having a composition was obtained. As a result of observation using the titanium suboxide sample in the same manner as in Example 1, no splash phenomenon was observed.

Comparative Example 1 555 g of titanium hydride powder having a particle size of 45 μm or less and 4445 g of titanium dioxide powder were blended, mixed for 12 hours by a dry mixer, and then formed into a tablet having a diameter of 10 mm and a thickness of 4 mm using a mechanical molding press. It was formed into pellets. Then, the pellets were placed in a vacuum atmosphere furnace, and heated at a temperature of 1220 ° C. for 8 hours for reduction firing. The obtained sintered body had a black-purple color, and the compound composition was measured by powder X-ray diffraction. As a result, Ti ₃ O ₅
Was confirmed. When this titanium suboxide was melted in an EB melting furnace and the state of splash was observed under vacuum, many splash phenomena occurred.

Comparative Example 2 Titanium hydride powder having a particle size of 45 μm or less and titanium dioxide powder were blended at a weight ratio of 1: 9, and mixed with a dry mixer for 12 hours. This mixed powder is compressed to a diameter of 10 using a hydraulic molding press.
into a 4 mm thick tablet pellet. Next, the pellets were filled in a vacuum atmosphere furnace, and heated and fired at 1300 ° C. for 3 hours while maintaining the inside of the furnace at a degree of vacuum of 1 Torr or less, and then cooled in the furnace. When the obtained product was measured by a powder X-ray diffraction method, it was confirmed that the product was titanium suboxide having a composition of Ti ₃ O ₅ . This titanium suboxide sample was EB
Melting was performed in a melting furnace, and a number of splash phenomena were observed under a vacuum atmosphere.

[0021]

According to the present invention, unlike the conventional reduction firing method, titanium dioxide and metal titanium powder and / or titanium hydride powder are mixed at a weight ratio of 8 to 9: 1. The powdery mixture obtained by mixing is kept as it is, under an inert gas atmosphere at a pressure higher than atmospheric pressure ,
By melting by non-consumable arc melting method, Ti ₃
A titanium suboxide having a composition of O ₅ is obtained. This titanium suboxide does not cause a splash phenomenon that occurs under vacuum heating at the time of vapor deposition as seen in conventional titanium suboxide, and is a vapor deposition material that can always form a smooth high quality titanium-based vapor deposition thin film. It became possible to provide. In addition, the method of the present invention is very simple in that the powdery mixture obtained by simply dry-mixing the raw materials is arc-melted as it is, and does not require any special consideration on the apparatus, and since capable of producing the desired product in the processing of short time, it is improved by a large margin in terms of cost.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-290529 (JP, A) JP-A-62-23659 (JP, A) JP-A-63-277506 (JP, A) JP-A-4- 224113 (JP, A) JP-A-4-325416 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C01G 23/04

Claims (2)

(57) [Claims] 1. A titanium dioxide and a metal titanium powder and / or a titanium hydride powder in a weight ratio of 8 to 9: 1.
Powdery mixture obtained by mixing in proportions ,
A method for producing titanium suboxide having a composition of Ti ₃ O ₅ , wherein the titanium suboxide is obtained by filling a mold and dissolving it by a non-consumable arc melting method in an inert gas atmosphere at a pressure higher than atmospheric pressure . 2. The method for producing titanium suboxide having the composition of Ti ₃ O ₅ according to claim 1, wherein the powdery mixture is melted by a non-consumable arc melting method while maintaining an atmosphere at the time of melting under an argon gas atmosphere. .