JPS61122198A - Rpoduction of antimony oxide whisker and apparatus therefor - Google Patents

Abstract

PURPOSE:Metallic antimony is roasted in an oxygen-containing atmosphere over a specific temperature to enable high-efficiency production of antimony oxide whiskers which are suitable for use as an industrial material. CONSTITUTION:Granules of metallic antimony are placed on an alumina base and roasted in an oxygen-containing atmosphere such as air at a temperature over 750 deg.C. The antimony oxide whiskers produced according to the present invention has a shape of rods or needles and can be used as an industrial material such as a filler for plastics.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a method and apparatus for producing rod-shaped or needle-shaped antimony oxide whiskers.

"Prior Art and its Problems" Metal oxides may have a shape such as a rod, a line, a needle, or a flake, and are called whiskers. Metal oxides that form whiskers include aluminum oxide (A1203), zinc oxide (ZnO),
Beryllium oxide (Bed), Magnesium oxide (Mg
O) etc. are known. These whiskers have the above-mentioned special shape and are extremely strong, so they are currently used as fillers for plastics, but their use in various other applications is also being considered.

As described above, whiskers made of various metal oxides are known, but antimony oxide (Sb20a) has not yet been known to form whiskers, and its properties have not been clarified.

"Object of the Invention" An object of the present invention is to provide a method for producing antimony oxide whiskers, which are expected to be applied to various uses as a new industrial material, and an apparatus for producing the same.

"Structure of the Invention" The method for producing antimony oxide whiskers of the present invention is a method in which antimony metal is fired at a temperature of 750° C. or higher in an oxygen-containing atmosphere.

Further, the antimony oxide whisker manufacturing apparatus of the present invention includes a reactor having an oxygen-containing gas supply port and a discharge port;
A porous plate installed in the oxygen-containing gas flow path in the reactor, a metal 7-inch supply means for supplying antimony metal onto the porous plate, and
℃ or higher.

Next, the present invention will be explained in more detail.

In the present invention, metallic antimony granules, powder, etc. are used as raw materials, and these are heated and fired in an oxygen-containing atmosphere. Here, the oxygen-containing atmosphere means oxygen or an atmosphere containing oxygen, and may be, for example, oxygen or air. For example, heating and firing can be performed using an alumina substrate, a magnetic crucible,
The above-mentioned antimony metal may be placed in a heat-resistant open container such as a quartz crucible, but industrially it is preferable to use the above-mentioned manufacturing equipment.The heating and firing temperature is such that the weight decreases when the antimony metal oxidizes. Perform the test at the desired temperature. That is, when metallic antimony is oxidized at high temperatures, it is thought to undergo sublimation or evaporation during oxidation, resulting in a decrease in weight, and in the process, it grows rod-shaped or needle-shaped single crystals to form whiskers. Therefore, whiskers can be formed more effectively by oxidizing metal antimony in a state where there is a large amount of sublimation or evaporation.

Expressing the oxidation rate of metal antimony in terms of the rate of weight loss, it is approximately -30 mg/crn' in 1 hour at 600°C.
Approximately -80mg/crrr' in 1 hour at 700℃, 80
It is about -150 mg/cm' at 0°C. As described above, the oxidation of metal antimony rapidly progresses at temperatures above about 700 to 800°C, and as a result, countless antimony oxide whiskers are produced.In the present invention, focusing on this point, the heating and firing temperature is set at 750°C or above. That's what I did.

Next, the above-mentioned manufacturing apparatus of the present invention will be explained. As the material of the reactor, a heat-resistant material such as ceramics such as quartz and alumina is used. A supply port and a discharge port for oxygen-containing gas are formed in the reactor, and the interior of the reactor serves as a flow path for # element-containing gas. A porous plate made of the same heat-resistant material as the reactor is placed in the oxygen-containing gas flow path. A large number of ventilation holes are formed in the perforated plate to prevent the powder of antimony oxide particles from falling. The supply means for metallic antimony is constituted by a supply pipe or the like arranged so as to face the perforated plate. A heating means such as a heater for heating to 750° C. or higher is provided near the perforated plate. Therefore, by supplying metal antimony onto a perforated plate, flowing oxygen-containing gas into the reactor, and heating the vicinity of the perforated plate to 7509C or higher, the metal antimony is rapidly oxidized and some of it is heated. sublimes or evaporates and flows out from the outlet together with oxygen-containing gas. At this time, since a large amount of antimony oxide whiskers are produced, these whiskers can be separated and obtained from the oxygen-containing gas by appropriate means.

The antimony oxide whiskers thus obtained had a size of 10
I for JL11-50, has a rod-like or needle-like shape with a length of about lav to 1O1111.

"Embodiments of the Invention" Comparative Example 1 Metallic antimony agglomerates (purity 99.H% 1 particle size 2-3+
m) Place 1g on an alumina substrate and heat at 700℃ in air.
The mixture was heated for 1 hour. As a result, antimony oxide whiskers having a rod-like or needle-like shape, a thickness of about 501 Lm, and a length of about 51I1 m or less were formed. The yield was about 50%.

Example 1 Metallic antimony agglomerates (purity 9L119%, particle size 2-3
mm ) 1g on an alumina substrate and 750 mm in air.
Heated at ℃ for 1 hour. As a result, anti-oxidation whiskers having a rod-like or needle-like shape, a thickness of about 50 gm, and a length of about 5 mm or less were obtained. The yield was about 70%.

Example 2 Metallic antimony agglomerates (purity 99.9!11%, particle size 2
~3++m) Ig was placed on an alumina substrate and heated in air at 800°C for 1 hour. As a result, antimony oxide whiskers having a rod-like or needle-like shape, a thickness of about 50#Lm, and a length of about 10+am or less were obtained. The yield is about 10
It was 0%.

Example 3 Metallic antimony agglomerates (purity 98.89%, particle size 2-3
mm) 1g on an alumina substrate and 850 mm in air.
Heated at ℃ for 1 hour. As a result, antimony oxide whiskers having a rod-like or needle-like shape, a thickness of about 50.1 m, and a length of about 10 m or less were obtained. The yield was about 100%. Example 4 Metallic antimony agglomerates (purity 99.i39%, particle size 2~
3+s) Place Ig on an alumina substrate and heat it in air for 90 minutes.
Heated at 0°C for 1 hour. As a result, antimony oxide whiskers having a rod-like or needle-like shape, a thickness of about 50 pm, and a length of about 10 mm or less were obtained. The yield was approximately 100%.

Note that the whiskers obtained in each of the above Examples were confirmed to be antimony oxide whiskers as a result of X-ray diffraction.

Example 5 An apparatus for producing antimony oxide whiskers as shown in FIG. 1 was created. That is, in this manufacturing apparatus, a supply port 13 for oxygen-containing gas 12 is formed at one end of a quartz tube 11, and a discharge port 14 for oxygen-containing gas 12 is formed at the other end. The inside of 1 serves as a flow path for oxygen-containing gas 12. A heat-resistant perforated plate 15 made of alumina or the like is installed inside the quartz tube 11.
A metal antimony supply pipe 1B is introduced so as to face above the perforated plate 15. A large number of ventilation holes are formed in the perforated plate 15 and are large enough to prevent grains and powder of antimony metal from falling. Further, an annular heater 17 is attached to the outer periphery of the quartz tube 11 located near the perforated plate 15.

In this manufacturing apparatus, metallic antimony granules, powder, etc. are supplied onto a perforated plate 15 from a supply pipe 1B. Then, oxygen-containing gas 12 previously heated to about 80° C. or higher is blown into the supply port 13, circulated inside the quartz tube 11, and discharged from the discharge port 14.

The reason why the oxygen-containing gas 12 is heated in advance is to prevent a drop in temperature inside the quartz tube 11 and to increase the oxidation efficiency of metal antimony. However, the oxygen-containing gas 12 at room temperature may be blown into the heater 1 in this state.
7, the inside of the quartz tube Il is heated to a temperature of 750° C. or higher in the vicinity of the perforated plate 15. Antimony metal is an oxygen-containing gas! It is oxidized by 2 and sequentially becomes antimony oxide and sublimes or evaporates. The sublimated or evaporated antimony oxide is carried upward together with the oxygen-containing gas 12, becomes antimony oxide whiskers, and flows out from the outlet 14. Therefore, the antimony oxide whiskers flowing out from the outlet 14 can be separated from the oxygen-containing gas 12 by appropriate means to obtain antimony oxide whiskers.

Note that the flow rate of the oxygen-containing gas 12 is preferably adjusted in accordance with the generation rate of antimony oxide whiskers, and is preferably not too high. According to experiments, a rate of about 1 sentence to 10 sentences/minute is preferable.

"Effects of the Invention" As explained above, according to the method for producing antimony oxide whiskers of the present invention, antimony oxide whiskers can be efficiently produced by firing metallic antimony at a temperature of 750°C or higher in an oxygen-containing atmosphere. Obtainable. Further, according to the apparatus for producing antimony oxide whiskers of the present invention, there is provided a reactor having an oxygen-containing gas supply port and a discharge port, a porous plate installed in an oxygen-containing gas flow path in the reactor, and a porous plate installed in an oxygen-containing gas flow path in the reactor. A metal antimony supply means for supplying metal antimony onto the porous plate and a temperature near the porous plate at 750°C.
By providing the above-mentioned heating means, antimony oxide whiskers can be produced industrially. The antimony oxide whiskers thus obtained have rod-like, needle-like, etc. shapes, and are expected to be used as various industrial materials such as fillers for plastics.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an embodiment of a manufacturing apparatus according to the present invention, and FIG. 2 is a 15x microscopic photograph showing crystals of antimony oxide whiskers obtained by the manufacturing method of the present invention. In Figure 1, 11 is a quartz tube, 12 is an oxygen-containing gas, 13 is an oxygen-containing gas supply port, 14 is an oxygen-containing gas discharge port, 15 is a perforated plate, 16 is a metal antimony supply pipe, and 17 is a metal antimony supply pipe. It's a heater. Procedural amendment (Own ship February 2z, 1933)

Claims (2)

[Claims] (1) A method for producing antimony oxide whiskers, which comprises firing metal antimony at a temperature of 750° C. or higher in an oxygen-containing atmosphere. (2) A reactor having an oxygen-containing gas supply port and a discharge port, a porous plate installed in the oxygen-containing gas flow path in the reactor, and a metal antimony supply supplying metal antimony onto the porous plate. means and the vicinity of the porous plate 75
1. An apparatus for producing antimony oxide whiskers, comprising a heating means for heating to 0° C. or higher.