JPS5964528A - Bismuth-molybdenum amorphous compound material and its preparation - Google Patents

Abstract

PURPOSE:To obtain a bismuth-molybdenum amorphous compound material useful as light-electricity responce element, light-magnetism response element, high ionic conduction material, etc., by melting a mixture of bismuth oxide and molybdenum oxide under heating, quenching it extremely quickly. CONSTITUTION:A mixture of bismuth oxide and molydbedum oxide having a composition in a weight ratio shown by the formula (MoO3)x.(Bi2O3)1-x(0.95<= x>0) as a raw material is melted under heating. The melting is carried out at a temperature wherein the mixture is sufficiently melted or higher, preferably at a temperature higher than the melting temperature by 50-200 deg.C. The raw material mixture is quenched extremely quickly. It is an essential condition. The supercooling is usually carried out at about 10<4>-10<6> deg.C/sec cooling speed. When the quenching device 3 is used, the raw material mixture is extruded from the melt extruding nozzle 11 to the surface of the high-speed rotating roll 13. The prepared material is made into a thin film, scaly or fine particulate state, to give an amorphous compound material.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel bismuth-molybdenum based amorphous compound material and a method for producing the same.

In recent years, with the development of electronics and related technologies, research has been actively conducted on oxide-based ceramics, mainly bismuth oxide (Bf203), and their single crystals.
In particular, research is being carried out as a conversion element and as a catalyst material in fields such as photo-electricity, sound-aroma, atmospheric gas-electricity, photoacoustic polarization, and X-ray spectroscopy. B! 203 and M
As stable compounds with OO3, only a few types of crystalline forms have been described in a few documents, and although research on single crystallization of these is currently being carried out, there are no amorphous compounds. No studies have been conducted on the compound.

The present invention provides a bismuth-molybdenum-based amorphous oxide that has been completely unknown heretofore.

That is, the present invention provides (B! 203 ) +−x ・(M
A novel bismuth-molybdenum amorphous compound material having a composition such that O03)x (0.95≧X >O>, and (Bt 203 ) +-x ・(MO03)x
(However, × corresponds to the above) This relates to a method for producing a bismuth-molybdenum-based amorphous compound material, which is characterized by heating and melting a mixture of bismuth oxide and molybdenum oxide, and then quenching the mixture. .

The bismuth-molybdenum amorphous oxide of the present invention
Electric response elements, optical-magnetic response elements, high ionic conductivity materials,
It is useful as an oxidation/dehydrogenation catalyst in organic synthesis.

In the present invention, the term "bismuth-molybdenum-based amorphous compound" is used not only when the compound is amorphous alone, but also when the amorphous contains a polycrystalline phase and when the high-temperature stable phase is present at the seedling temperature. It is said to include the case where it is also generated.

The bismuth-molybdenum amorphous oxide of the present invention is produced as follows.

The raw material used in the present invention at °C is a mixture of bismuth oxide and molybdenum oxide, and its composition ratio is (M
O03)x ・(Bi 203 ) +-x (However, 0
．． The quantity ratio is 95≧×〉O). A raw material mixture having the above composition ratio is heated and melted, and then cooled extremely rapidly. Heat melting is
The heating may be carried out at a temperature higher than the temperature at which these raw material mixtures are sufficiently melted, preferably at a temperature higher than the melting temperature by 50 to 200° C., particularly preferably by 80 to 150°C. There are no particular restrictions on the atmosphere during heating, and heating is usually performed in air.

Next, the melt of the raw material mixture is ultra-quenched. , ultra-quenching is an essential requirement of the method of the present invention, and only by this is it possible to obtain a novel amorphous metal.

Ultra-quenching is usually performed at a cooling rate of about 10A to 100°C/sec. This ultra-rapid cooling can be carried out by a wide variety of means as long as it can be cooled at the above-mentioned cooling rate, and by spraying the melt of the raw R1 mixture onto the surface of the roll rotating at high speed, the atomic arrangement in the liquid state is achieved. A typical example is a method of solidification.

An example of a quenching apparatus for a molten raw material mixture used in carrying out the method of the present invention will be described below with reference to the drawings.

Figure 1 shows the main body of the rapid cooling device (3) installed on the stand (1).
) is shown. The quenching device consists of a dielectric heating coil (5
), (5)..., raw material heating tube (7), support for the tube (7) (9), melt source F31 spout river nozzle (11), quenching roll (13), nozzle ( 11)
cooling nozzle <15), anti-vortex air nozzle (17)
The main components include a fine adjustment mechanism (19) for the nozzle (11), an air cylinder (21>), a box (23>) for receiving the cooled material, and a cooling material outlet (25).

By installing a noan for cooling the quenching roll (13) and providing an air blowing port at the end of the roll surface, the molten M raw material can be quenched stably. FIG. 2 shows details of the support 9). In FIG. 2, the support (9) includes a cooling water introduction path (29) equipped with a valve (27), a cooling water extraction path (31), and a blow air introduction path (<35) equipped with a needle valve (33). , a mechanism (37) for finely adjusting the distance between the surface of the roll (13) and the nozzle (11), and a rectifier (39) for uniformly extruding the raw material melt.

When carrying out the method of the present invention using the quenching device 3) shown in FIGS. 1 and 2, first, a raw material mixture of a predetermined composition is passed through a tube (7) connected to a melt blowing nozzle (11). The tube (7) is preferably made of a material that is sufficiently durable under high temperature oxidizing atmosphere conditions, such as platinum, platinum-rhodium, iridium, silicon nitride, boron nitride, etc. The material 1 for the parts that do not come into direct contact with the raw F31 melt may be ceramics, glass, or metals with a high melting point.The shape of the nozzle opening is appropriately determined depending on the target product. In case of wide product [1], use a slit-shaped one.The shape of nozzle 1] may be circular or other shape.Inside the tube (7) The stored raw material mixture is then heated to a temperature higher than its melting point to form a melt, and then is applied to a constant gas pressure from the [ ] part of the nozzle (11) onto the surface of the roll (13) rotating at high speed. It is blown out and rapidly cooled on the roll surface.The nozzle opening and [1-
The blowing angle of the raw material melt on the plane is t of the target compound.
When lJ is about 3 mm or less, it may be perpendicular to the roll surface, and when the width is about 3 mm or more, it is at 00 to 45 degrees to the normal to the roll surface. Although these blowout angle adjustment mechanisms can be incorporated into the device itself as a mechanism that can set a predetermined angle, it is preferable to process the nozzle itself so that L13<.

The method of heating the raw material mixture is not particularly limited, but it is usually carried out in a furnace with a Brahma heating element, a dielectric heating furnace, or a concentrator heating furnace.

The temperature of the raw material melt is preferably 50 to 200°C, preferably 80 to 150°C higher than its melting point. If the temperature is too close to the melting point, there is a risk that the melt will cool and solidify near the nozzle while it is being blown onto the surface of one coil.On the other hand, if it is too close to the melting point, it may cool and solidify near the nozzle.
Rapid cooling tends to be difficult.

The pressurizing gas used to blow out the melt onto the roll surface is preferably an inert gas, such as argon,
Although nitrogen, helium, etc. may be used, dry compressed air is preferable in order to maintain the melt raw material in an oxidized state. The gas pressure is usually 0.1 to 2.0 ka, depending on the size of the nozzle [1].
/cm2 is preferably about 0.5 to 1.0k(]/cm2. Also, the distance between the nozzle opening and the roll surface when blowing out the raw material melt is preferably about 0.01 to 1.On+m.
More preferably, it is about 0.05 to Oy5IRm. 0
．． If it is smaller than 0.01 mm, there will be very few paddle phrases and no uniform material will be obtained, while 1. When QmI is larger than 11, the number of paddle members becomes excessive, and when the thickness exceeds the thickness of the paddle formed by the interfacial tension of the composition melt, it may be difficult to form a paddle.

The materials of the roll include copper and its alloys, which have good thermal conductivity, hard metals [the above-mentioned materials that form the uneven layer], steel, stainless steel, and the like. IJ-ru peripheral speed from 5m/sec to 35
m/sec, preferably 10 m/sec to 20 m/sec, and quench the raw material melt to obtain a high-quality amorphous compound material for the purpose.

In this case, if the peripheral speed of the roll is 5 m/sec or less, it is not very preferable because it tends to be difficult to become amorphous. [J
- When the circumferential speed of the ring is higher than 35 m/sec, the shape of the target material obtained becomes extremely thin and becomes scaly or fine powder, but the material structure is still the same as the amorphous compound of the present invention. It is the material.

When producing the compound of the present invention under reduced pressure or high vacuum or in an inert gas atmosphere without blowing out the raw material melt onto the rotating roll surface, reduction of the raw material melt at high temperature may occur. , a decrease in oxygen atoms in the composition atoms occurs, and the resulting material becomes colored purple or black. However, this colored product is also a compound of the present invention physically and can be used in a colored state.

When heating and melting a raw material mixture in a tube, it is necessary to completely melt the mixture. However, before the mixture is completely molten, some of the molten material may flow out from the nozzle tip, so the nozzle tip is locally cooled to prevent the melt from flowing out. It is preferable to prevent this. A typical means of locally cooling a nozzle is to blow a cooling gas onto the tip of the nozzle.The gas may be an inert gas such as abrasive, helium, or nitrogen, but dry, cold compressed air is preferable. More preferred.

The novel amorphous compound material according to the present invention usually has a
It has a thickness of about 10 μm and is a very brittle material.

For this reason, after being rapidly cooled and solidified on the roll surface, it is preferable to keep the material in a state where stress is not applied to it as much as possible. One of the causes of stress addition and number 4 is the large turbulent flow in the air layer on the roll surface due to the wind blowing phenomenon caused by roll rotation in the atmosphere. In order to prevent this turbulence and to improve the adhesion between the molten raw material mixture to be thoroughly cooled and the roll surface, a countercurrent blowout nozzle for preventing wind blowing, that is, an air nozzle for preventing swirling (17) shown in Fig. 1 is installed. Can you install it?
[''-Fixed the fan inside the room. In the latter case,
Due to the rotation of the roll, the turbulent flow generated inside the roll is pulled into the roll through a variable-diameter air intake provided at the pant part on the surface side of the roll, and is discharged from the front of the shaft of the roll. On the surface, the air is moved inside the roll, which brings the melt closer to the roll surface, and the roll itself can also be air-cooled by the blown air movement. Further, in order to maintain the dimensional uniformity of the obtained material, if grooves for monthly cutting are provided on the roll surface at right angles to the direction of rotation, the material can be cut to a constant size.

The atomic arrangement of the bismuth-molybdenum compound of the present invention varies greatly depending on the mixing ratio of the raw materials, and specifically, it can be broadly classified into the following types.

First, when 0.55≦X≦0.95, a 100% amorphous compound is obtained, and when 0.35≦X<0.55, δ-B! A mixture of 203 multicrystalline phase oligochromic and amorphous compound is obtained, and when Q Figure 3 shows the production range of the 4-O material of the present invention.

When the circumferential speed of the quenching roll of the quenching device used is within the range of 5 m/sec to 3 bm/sec, no significant change is observed in the structure of the material obtained in each composition range.

In order to identify the structure of the present invention, the presence or absence of crystallinity was confirmed and structural analysis was performed using X-ray diffraction and a polarizing microscope, and a very small portion was observed using a scanning electron microscope.

The following examples will further clarify the features of the present invention.

Example B I 203 (i I-a 99, 996 >) and MOO3 (purity 99.9%) were blended in a predetermined composition, mixed uniformly, and then calcined at 850°C for 30 minutes to form a composition raw material. The obtained composition raw material was put into a platinum tube (diameter 1
0101l1 length 15Qmm), installed in a heating coil with induction S Conditions T"i of .8Δ: Dielectric heating was performed. The completely molten raw material was blown out with dry compressed air onto the surface of the quenching rotary L1-ru to avoid quenching.

Tables 1 and 2 show the composition and manufacturing conditions. Samples Nos. 1 to 2o and 29 in Tables 1 and 2 are ribbon-shaped amorphous l! τ indicates the tetraoxide material 11. Also, N
O, 24 is a thin piece due to the high rotational speed of [1-ru], but it can be used in fields such as catalysts where there are no restrictions on shape.

In addition, nozzle shape A means 0.2 mm x lI.
The nozzle shape B indicates a circular nozzle with a diameter of 0.2 mm. Further, the composition is, for example, X ~ 0.90, which means that (Bt 203 ) .(MO03) is 0.10 0.90 in (Bl 203 )+-x .(MO03)x.

Reference Example 1 Sample No. of the above example corresponding to CX=0.70 in (B!203)+-x/(Mo03)x.

The X-ray diffraction results for 5.6.7 and 8 are shown in FIG. The peripheral speed of the quenching roll is 5.18 m/s (No. 7
) to 34.54 m/sec (No. 8), it is clear that no major change is observed in the 1-kyoko array structure of the material obtained within the range of 34.54 m/sec (No. 8).

Reference Example 2 Sample No. of the above example corresponding to CX-0,70 in (Bi 20a ) +-x .(Mo 03 )X.

The differential thermal analysis results of No. 5 are shown in FIG.

In FIG. 5, Tc is the crystallization temperature, and 1-(l is the glass transition point.The exothermic peak due to crystallization is 38
It is 3℃.

Reference Example 3 (Bi 203 ) +−X ・(MO03) Sample No. of the above example corresponding to X=0.65 in x.

A photograph showing the appearance of No. 12 is shown as a reference drawing.

Reference Example 4 Scanning electron micrograph of sample No. 12 of Example 4
(20,000x) is shown as a reference drawing ■.

Reference example 5 ([3f 203 ) +-x ・(MO03) Sample N01 of the above example corresponding to x-0,90 at x
FIG. 6 shows the infrared absorption spectrum of sample No. 012 of the example, which corresponds to X = 0.65.

[Brief explanation of the drawing]

FIG. 7 is a front view of an example of a quenching device for molten raw materials used in the method of the present invention, FIG. 2 is a partially enlarged detailed drawing of the quenching device in FIG. 1, and FIG. Drawings showing the composition range, FIG. 4 is a young X-ray diffraction diagram of the material of the present invention, FIG. 5 is a differential thermal analysis diagram of one material according to the present invention, and FIG.
The figures respectively show the infrared absorption spectrum of the materials according to the invention. 1)... Frame, (3)... Rapid cooling device body, (5), (5)... Dielectric heating coil,
(7)... Raw material heating tube, (9)...
...Support for raw material heating tube, (11)...
... Nozzle for spouting molten raw material, (13) ... Roll for rapid cooling, (15) ... Cooling nozzle for nozzle (11), (17) ... Preventing vortex flow Ding nozzle,
(19)...Fine adjustment machine for nozzle (11), (
21)...Air cylinder, (23)...
...The container for the cold 711 material is a box, (25)...
・Cooling material outlet, (27)... Valve, (
2)...Cooling water introduction channel, (31)...
・Cooling water discharge channel, (33)...21 dollar valve, (35)...but1-air inlet channel, (3
7)...1]-Mechanism for finely adjusting the interval between the tube (13) and the nozzle (11), (39)...Perforated plate for rectification. (That's all) 199 Figure 1 Figure 3

Claims (1)

[Claims] ■ (E3!2u3)+-x ・(MOO3)x (
However, a bismuth-molybdenum-based amorphous compound material having a composition of 0.95≧×〉O). ■ Claim 1 where 0.95≧X≧0.55
Smooth molybdenum-based amorphous + p compound material. ■ Q'r M'F where 0.55>x≧0.35%
A bismuth-molybdenum-based amorphous compound material according to item 1 of the FA requirement. ■ It is characterized by heating and melting a mixture of bismuth oxide and molybdenum oxide and then ultra-quenching the melt (B!
203) +-X ・(MOO*) A method for producing a bismuth-molybdenum-based amorphous compound material having a composition x. (104-b) A method for producing a bismuth-molybdenum-based amorphous compound material according to claim 4. (2) A method for producing a bismuth-molybdenum amorphous compound material according to claim 4 or 5, which comprises ultra-quenching the raw material melt by bringing it into contact with a solid. ■ The raw material mixture is put into a heating tube equipped with a slit-shaped, circular or oval-shaped nozzle.
A patent for heating and melting the mixture at a temperature 50 to 200 degrees Celsius higher than the melting point of the mixture, and then blowing the melt through the nozzle onto the surface of a roll rotating at a circumferential speed of 5 m/sec to 35 m/sec for ultra-quenching. Bismuth-molybdenum-based amorphous compound material 1 according to any one of claims 4 to 6
manufacturing method.