JP2003054919A - Highly dispersible high sphericity aluminum oxynitride powder, method and apparatus for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide novel high sphericity aluminum oxynitride powder and a method and an apparatus for manufacturing the same. SOLUTION: The aluminum oxynitride powder in which it is attained simultaneously that the grain growth of raw material powder is suppressed to have a primary particle diameter ranging from 0.05 μm to 100 μm, the melting, solidification or aggregation of a product is prevented and high dispersibility and/or the rounded external shape of the particles are exhibited is manufactured using a manufacturing method and a manufacturing apparatus for advancing an oxynitride reaction in a vapor phase in the presence of flame by controlling the following technical requirements at the same time, that is (1) the adjustment of gaseous atmosphere in the flame and the stabilization of the inner flame or a reduction combustion flame, (2) the utilization of a direct nitriding method or a reduction nitriding method using heat energy by the flame as driving force, (3) the formation of vapor phase dispersion (an aerosol state) of the raw material powder and the efficient supply to the reaction field and (4) the ratio control of the raw materials and the flame quantity or the continuity of a heat treatment process. Then the particle diameter and the sphericity necessary as a sintered compact raw material powder in an optical material utilizing translucency by an isotropic crystal structure or a melting resistant material utilizing high thermal shock resistance and the low wettability/low reactivity to molten steel are attained simultaneously.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel aluminum oxynitride powder, a method for producing the same, and an apparatus for producing the same. More specifically, the present invention relates to an oxynitriding reaction of a raw material powder in the presence of a flame under atmospheric pressure. Applied in the gas phase, the heat energy and reducing power of the flame are used as the driving force for the oxynitriding reaction, and the oxynitriding reaction proceeds in the gas phase to prevent melting and solidification or aggregation of the product. , The process is simple and cost-effective, the direct nitriding method of the raw material metal powder realizes the raw material powder fusion and the grain growth suppression, and the main application is the optical system material utilizing the translucency due to the isotropic crystal structure, In melt-resistant materials that utilize high thermal shock resistance or low wettability / reactivity with molten steel, achieve the particle size and sphericity required for the raw materials at the same time, and especially suppress the grain growth of the raw material powder. The range of primary particle size is 0.05 to 1 The present invention relates to a novel aluminum oxynitride powder, which is included in 0 micron and has small melting and solidification and aggregation of the product, high dispersibility and / or non-angular outer shape of particle, and a manufacturing method and manufacturing apparatus thereof. Is.

[0002]

2. Description of the Related Art Generally, among optical materials, materials that are excellent in light transmission in visible and infrared wavelengths, and at the same time have high heat resistance and abrasion resistance are used in arc atmosphere materials such as arc tube materials, high temperature window materials, and space shuttles. It is sought after as a high-strength window material. As one of the materials of this type, a translucent alumina sintered body has been widely put into practical use for a high pressure sodium arc tube. However, alumina has a hexagonal crystal structure having anisotropy, and light scattering due to birefringence at crystal grain boundaries is unavoidable. Therefore, although scattering is reduced by coarsening the crystal grain size, the reduction in strength is an unavoidable problem. In addition, it is important for the melt resistant material such as a refractory material to have low activity with molten steel, high temperature stability and oxidation resistance, and low wear due to molten steel flow (that is, high temperature mechanical strength). Sialon is a good material for this, but S at high temperatures
There is also a view that it is not suitable as a melt-resistant material due to the affinity between i and Fe.

Of aluminum nitride and aluminum oxide
Aluminum oxynitride, which is polymorphic, has an isotropic cubic crystal structure.
It has excellent translucency without grain boundary scattering,
High thermal shock resistance or low wettability with molten steel,
Since it is a Si-based material, it is considered to be a promising material as a melting resistant material.
ing. Up to now, the multi-system has been AlN, Al₁₆O₃ 
N₁₄, Al_TenO₃ N₈ , Al₉ O₃ N₇ , A₁₇O₃ N
_Five , A_l6O₃ N_Four , Al_{twenty three} O₂₇N_Five, Al_19.7O_29.5
N_2.5 , Al_{twenty two}O₃₀N₂, Al₁₉O₂₇N, Al₂₇O
₃₉ N, Al2 O3, etc. are known (Al element / O element
The element ratio is included in 0.67 to 5.3, and Al element / N element
Ratio of 1 to 27), especially cubic spinel type
Al_{(64 + x) / 3 (8-x) / 3} O_32-xN_x (However, □ is a cation
Voids, 0 ≦ x ≦ 8) are well studied.

As a method for producing aluminum oxynitride,
Direct nitriding method of metal Al powder similar to aluminum nitride,
In addition to the reduction nitriding method of Al ₂ O ₃ and graphite, Al ₂ O ₃ and Al
A method of firing a mixture of N at a high temperature in a nitrogen atmosphere,
Recently, a vapor phase synthesis method using arc plasma under a low pressure atmosphere has been reported. Among them, the high temperature firing method of an Al ₂ O ₃ -AlN mixture has an advantage that the composition control of aluminum oxynitride having many polysystems is relatively easy, and is a general method as a manufacturing method thereof. [For example, 1) Shinji Hirai, Hideaki Murakami, Hiroshi Katayama, Yoichiro Uemura, Mamoru Santomo "Production of Aluminum Oxynitride Spinel from Alumina and Aluminum Nitride", 2) Japan Institute of Metals, Vol. 58, p.
648, 1994]. However, Al ₂ O ₃ -Al
The N high-temperature firing method is a solid-solid reaction, requires heat treatment at high temperature for a long time, and it has been reported that the actual firing temperature reaches 2000 ° C. or higher. The powder produced under such firing conditions becomes coarse, and subsequent pulverization is not easy. Therefore, there has been a problem that a sufficiently satisfactory characteristic cannot be exhibited as a supply route of the easily sinterable raw material powder for producing a high strength sintered body. Furthermore, long-time heat treatment and pulverization are also problems in terms of purity.

On the other hand, the direct nitriding method utilizing the exothermic reaction due to the high activity of metallic Al is one of the so-called combustion synthesis methods.
It has been considered since about 00 years ago. Although this is a simple process and is most advantageous in terms of cost, it is common that grain growth of the produced powder easily occurs. Moreover, in the current direct nitriding process under "normal pressure", the
A heat treatment at a melting point of Al of about 000 to 1500 ° C. or higher is required. That is, according to the existing direct nitriding manufacturing method,
(1) violent exothermic reaction, (2) heat treatment above Al melting point,
As a result, the produced powder was in a state of being solidly agglomerated (fused). Therefore, this method also does not solve the problems of coarsening of the product and low purity [eg 1) Normand
D. Corbin, Aluminum Oxynitr
ide Spinel, 2) A Review, Jou
rnal of the European Cera
mic Society, Vol. 5, p. 143, 1
989, 3) Jason Shin, Do-Hwan.
Ahn, Mee-Shik Shin and Yon
g-Seog Kim, Self-propagati
ng High Temperature Synth
sis of Aluminum Nitride
Under Lower Nitrogen Pres
sures, Journal of the Amer
ican Ceramic Society, Vol.
83, p. 1021, 2000].

Aluminum oxynitride is usually unstable and generally has the above non-stoichiometric structure. To date, spinel aluminum oxynitride with stoichiometric composition has been produced only by the melting method using an arc image furnace (Yoshihiro Kuwano, Toshio Hirai, AlN-based ceramics and their vapor phase synthesis, Bulletin of the Japan Institute of Metals, Vol. .3
0, p. 913, 1991). The plasma arc melting method has the advantage of gas phase (aerosol) synthesis that enables the production of fine, highly pure powder with a relatively high degree of sphericity, and enables fine control of the stoichiometric composition by adjusting the reaction atmosphere. It is expected that future development will be achieved (eg, Hir
oyuki Fukuyama, WataruNaka
o, Masahiro Susa and Kazuh
iro Nagata, New Synthetic
Method of Forming Aluminum
Oxynitride by Plasma Arc
Melting, Journal of the A
Merchanic Ceramic Society, V
ol. 82, p. 1381, 1999; or JP-A-11-1999
-268910). However, the conventional vapor phase method of aluminum oxynitride is a decompression vapor phase process, and there is a problem of manufacturing cost in that decompression (vacuum) equipment is essential. Along with that, it is pointed out that it is not known at present whether it is possible to maintain the above-mentioned high characteristics in the case of an industrial process (for example, scale-up). Further, since the vapor phase method under reduced pressure uses the evaporation-condensation reaction as a driving principle, it is inevitable that powder synthesis at the nanometer level (several tens of nanometers at the maximum) is possible. Is not necessarily suitable for the material system in the technical field targeted by the present invention. In general, the above-mentioned "ultrafine particles" are difficult to handle by powder engineering such as collection, dispersion and molding, and are easily aggregating powders, and are rarely used as raw material powders for sintered bodies. Rather, it is used as a thickener filler. That is, in the powder supply process for the sintered body raw material, it is required to be able to synthesize powder with an average particle size from the submicron level to the micron level with good controllability. For that reason, there is a possibility that it takes a long time or a high concentration of the precursor is required, and the controllability of the product is lowered. Moreover, since it is a reduced pressure gas phase process, the precursor
The flexibility of increasing the concentration is relatively small.

[0007] In the vapor phase method which can exhibit superiority in a difficult synthesis system, in addition, a CVD vapor phase synthesis method of a low boiling point precursor of Al (for example, B. Aspar, B. Armas, C. Co.
mbscure and D.M. Thenegal, O
rganometallic Chemical Va
pour Deposition IntheAl-O
-N System, Journal of the
European Ceramic Society,
Vol. 8, p. 251, 1991) has been studied, but it has the same problems as the plasma arc melting method. Also, aluminum oxynitride was discovered in Japan around 1960, but it is a material system with a relatively short history compared to Al 2 O ₃ etc., and it is hard to think that the manufacturing method itself is necessarily optimized. Is also pointed out. That is, according to the three main manufacturing methods of the existing aluminum oxynitride powder,
(1) Coarse particle size and low purity are not possible with Al ₂ O ₃ -AlN high temperature firing method, (2) Coarse particle size and low purity are not possible with Al direct nitriding method, (3) Plasma arc melting method The gas phase synthesis method such as has a problem in the desired particle size range and the reduced pressure gas phase process, and a method of producing a powder satisfying the particle size required for high sinterability with high productivity and economical efficiency. -None of the devices was available at this time.

The inventors of the present invention have considered such a situation,
In the course of various investigations, we focused on amorphous spherical silica powder, which is the current typical filler that no one could have expected so far, as a method for economically producing high-purity powder of the above size. did. A "chemical flame process" is generally used for this powder, in which silica raw material or Si metal powder is charged into the combustion flame of a mixed gas of combustible gas and oxygen, and the raw material surface is melted or vaporized in the gas phase. It has been practiced to produce silica particles having a high sphericity by controlling the particle size range by using the reaction-crystallization process in combination. Spherical particle formation by this method takes advantage of the feature of aerosol synthesis that it is easy to form a spherical shape because it is less sterically affected by the surroundings when a chemical reaction proceeds in the gas phase. There is. Further, since this method does not use only the evaporation-condensation reaction as a driving principle, it can be applied not only to ultrafine particles but also to a micron level to a filler powder size of 10 to several microns.

If this method and manufacturing apparatus can be applied to aluminum oxynitride powder, (1) elimination of the disadvantage that the particle size is unsuitable (coarse or too small) or the shape anisotropy (due to pulverization) is large, (2) ) By utilizing the intellectual property and know-how of powder synthesis accumulated by silica filler synthesis, improving the controllability of powder properties such as particle size distribution, and shortening the study time to obtain the required properties, (3) Many advantages can be expected, including the advantage of initial capital investment due to the diversion of chemical flame manufacturing equipment. However, to date, no one has been able to anticipate the “aluminum oxynitride powder / chemical flame process” and has not been realized. The reason is as follows: (1) It is not considered that non-oxides can be synthesized in a flame in which "oxygen" exists, and there was no idea to utilize the reducing power against oxygen such as internal flame or reducing combustion flame. thing,
(2) It is impossible to produce aluminum oxynitride that is not a perfect oxide by simply introducing the raw material into the flame in which "oxygen" exists. (3) Unlike silica, an acid that is also a high melting melting resistant ceramic. With aluminum nitride, spheroidization due to "melting of raw material powder surface" cannot be expected,
(4) Comparison of multiple reactions that characterize vapor phase synthesis, considering that powder having a complete aluminum oxynitride crystal structure (especially γ spinel) must be synthesized in one reaction (1 process) It is considered that it was because we did not pay attention to the point that it can be easily serialized.

[0010]

The present invention has been newly developed in view of such a situation, and overcomes the drawbacks of the above conventional aluminum oxynitride powder, its manufacturing method and manufacturing apparatus. However, the thermal energy and reducing power of the flame are used as the driving force for the oxynitriding reaction, and the oxynitriding reaction proceeds in the gas phase to prevent melting and solidification or aggregation of the product (particularly,
Direct nitriding method of raw metal powder, which is simple in process and advantageous in cost, realizes raw material powder fusion and grain growth suppression), and its main application is optical system material utilizing translucency due to isotropic crystal structure, or High thermal shock resistance or low wettability with molten steel
For molten ceramics that utilize low reactivity,
Achieving the particle size and sphericity required as raw materials at the same time,
In particular, the particle growth of the raw material powder is suppressed and the range of the primary particle size is included in the range of 0.05 to 100 μm, the melt coagulation and the agglomeration of the product are small, the high dispersibility and / or the outer shape of the particles are angular. It is an object of the present invention to provide a novel aluminum oxynitride powder that simultaneously achieves the above, a manufacturing method and a manufacturing apparatus thereof.

[0011]

The present invention for solving the above-mentioned problems comprises the following technical means. (1) An aluminum oxynitride powder produced by subjecting a raw material powder to an oxynitriding reaction in a gas phase in the presence of a flame, the oxynitriding reaction being applied in a gas phase under atmospheric pressure, Characterized by suppressing the particle growth of the raw material powder and having a primary particle size range of 0.05 to 100 microns, which has little melting and solidification or aggregation of the product, is highly dispersed, and has a non-angular outer shape. Al,
A powder containing O and N elements. (2) Adjusting the oxygen concentration in the flame so that the ratio of Al element / O element is included in 0.67 to 5.3 and the ratio of Al element / N element is included in 1-27. Characterized by,
A powder containing the elements Al, O and N described in (1) above. (3) Flame of combustible gas, combustion flame of mixed gas of combustible gas and oxygen, reducing combustion flame in which the proportion of combustible gas and oxygen is less than the complete combustion ratio, flame of plasma of inert gas, Alternatively, in the presence of a flame selected from arc flames generated between substances in a non-contact state, the thermal energy and reducing power thereof are utilized, Al, O and N described in (1) above. Powder containing elements. (4) Al, O described in any of (1) to (3) above
And a method for producing a powder containing N element, the step of forming a raw material powder in a dispersed state in a gas phase, an acid for directly nitriding or reducing nitriding the raw material powder in a gas phase in the presence of a flame. A method for producing a powder containing Al, O and N elements, which comprises the steps of producing an oxynitride by subjecting it to a nitriding reaction, or these steps and a step of heat-treating the oxynitride. (5) Al, O described in any of (1) to (3) above
And a device for use in a method for producing powder containing N element, comprising a flame generating device, a raw material powder supplying device,
A reaction gas supply device is included as a component, and in the flame generation device, the raw material powder and the reaction gas are diffused and mixed, and the ratio of the fuel and the oxygen amount is controlled so that carbon does not remain, and the raw material powder A production apparatus characterized in that an oxynitriding reaction is allowed to proceed in a gas phase in the presence of a flame. (6) A flame generating device having a structure in which a plurality of cylindrical tubes having different inner diameters are coaxially combined is included as a constituent element, the raw material powder is supplied to one of the cylindrical tubes, and the reaction gas is supplied to another cylindrical tube. Is supplied, the raw material powder and the reaction gas are diffused and mixed near the tip of the cylindrical tube, and the ratio of the fuel and the oxygen amount is controlled so that carbon does not remain, and the oxynitriding reaction of the raw material powder is performed. The manufacturing apparatus according to (5) above, wherein the manufacturing apparatus is configured to proceed in a gas phase in the presence of a flame.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in more detail. As described above, the present inventors have made various investigations. (1) First, the flame in which “oxygen” exists is
Rather, it can be thought of as a reaction field with a large reduction activity. (2) Second, in the internal flame with excessive combustible gas, or with reducing the ratio of combustible gas and oxygen to the complete combustion stoichiometric ratio It can be regarded as a reaction field of oxynitride (or nitride) by using combustion flame and supplying the reactant "effectively" to it. (3) Thirdly, the melting process like silica is used. Even if it is not possible, when the chemical reaction proceeds in the gas phase, there is little effect from the surroundings sterically, so it is possible to utilize the feature of aerosol synthesis that it is easy to form a spherical shape, and By allowing the oxynitriding reaction to proceed in the phase, it is expected that melting and solidification and agglomeration of the product can be prevented at the same time as spheroidizing (particularly, direct nitriding of the raw material metal powder, which has a simple process and is cost effective). Method to suppress raw material powder fusion and grain growth Furthermore, the abundance of regulators of vapor phase synthesis means high controllability of the characteristics of particles produced. (4) Fourth, in the chemical flame method, there are a plurality of characteristic features of vapor phase synthesis. We paid attention to the fact that it is possible (or relatively easy) to use the reaction continuously.

As a result of earnest studies to realize the above idea, specifically, (1) the oxygen concentration in the combustion flame or the plasma flame is adjusted, and a stable internal flame or reducing combustion flame is obtained. Maintaining, (2) applying a direct nitriding method or a reductive nitriding method, which uses thermal energy from a flame as a driving force, as a main reaction system, from the viewpoint of realizing a suitable particle size and productivity, (3) fluidization To efficiently supply a powdery raw material to a reaction field in a highly dispersed state with less aggregation, such as by utilizing a fluidized bed process in which a medium is used in combination,
(4) Improving the productivity of the aluminum oxynitride crystal structure by optimizing the amount ratio of the raw material and the flame, or producing a multisystem phase composed of Al element and / or O element and / or N element as a precursor, To make the aluminum oxynitride crystal structure by continuing the heat treatment process in the latter stage, and
By simultaneously and effectively combining the above four points of control, it has been possible to manufacture an aluminum oxynitride powder that achieves the particle size and sphericity required as the sintered body raw material powder.

That is, the present invention simultaneously achieves the particle size and sphericity required for the sintered body raw material powder (which was only an imaginary product until now), and in particular suppresses the grain growth of the raw material powder. The range of the primary particle size is 0.05 to 100 μm, and the melt coagulation and agglomeration of the product are small, and the high dispersibility and / or
The present invention also provides an aluminum oxynitride powder that simultaneously realizes that the outer shape of the particles is not angular, a manufacturing method for directly synthesizing the aluminum oxynitride powder, and a manufacturing apparatus therefor. The force is used as a driving force for the oxynitriding reaction, and the oxynitriding reaction is allowed to proceed in the gas phase to prevent melting and solidification or aggregation of the product.

As described above, the important technical requirements of the present invention are the following four points. That is, (1) adjustment of gas atmosphere in flame and stabilization of internal flame and reducing combustion flame, (2) use of direct nitriding method or reduction nitriding method using thermal energy of flame as driving force, (3) Formation of gas phase dispersion (aerosol) state of raw material powder and efficient supply to reaction field, (4)
Controlling the ratio of the raw material and the flame amount, or making the heat treatment process continuous.

In the present invention, as a method of forming and utilizing the fluidized or vapor-phase dispersed (aerosol) state of the raw material powder,
Various fluidized bed methods in which the powder is retained by the air flow (medium that has a diameter of several hundred μm and is larger than the raw material powder and easy to fluidize is used at the same time to prevent the raw material powder from aggregating and achieve high dispersion. (Including a fluidized bed method and a vibrating fluidized bed method in which vibration is applied to the powder layer to prevent fine particles from channeling) are preferably used. For example, the powder is further flown using a rotating disk or a gas nozzle. Various spraying methods, such as a liquid spraying method in which a powder is dispersed in a liquid medium and the powder is made into droplets with an ultrasonic sprayer or a centrifugal sprayer can be appropriately used, and are particularly limited. Instead, a fluidized raw material powder prepared by any method can be used. As a supply / control device for air, nitrogen, ammonia, or an inert gas, a compressed gas type supply device such as a compressor, use of internal pressure of a high pressure gas cylinder supplied from a gas production facility,
A floating ball type flow meter, a mass flow controller, etc. are exemplified.

Further, as a method of supplying the raw material powder to the reaction field by utilizing the gas phase dispersion state, it is possible to include the entire flame,
Such as quartz, alumina, cordierite or heat resistant steel,
A method in which a reaction tube or a wall is provided and reaction efficiency is improved by sealing generated heat energy or the accuracy of feeding powder is improved is preferably used. For example, further (however, if there is no problem in reaction efficiency, ) A method of supplying the raw material powder into the flame generated in the free space can be appropriately used and is not particularly limited, and a supplying method prepared by any method can be used. Further, in the introduction path of the raw material powder and the nitriding source (nitrogen, ammonia or inert gas) into the flame, a raw material supply pipe having a structure in which a plurality of cylindrical pipes having different inner diameters are coaxially combined is provided. A flammable gas that is a flame raw material or an inert gas for plasma generation is supplied from the outside, and a double cylinder system in which oxygen and raw material powder and a nitriding source are supplied from the inside is preferably used.
(However, if there is no problem with the driving principle of the reaction system, the mixing state of the raw material powder and the nitriding source, and the supercooling of the flame) In addition to the above-mentioned raw material supply pipe, in the flame generated from the flame raw material and oxygen A method of supplying the raw material powder and the nitriding source from the surroundings can be appropriately used and is not particularly limited, and an introduction route prepared by any method can be used.

When the raw material powder is supplied to the reaction field by utilizing the gas phase dispersion state, the particle size distribution of the raw material powder is adjusted by cyclone classification and coarse particles are removed to improve the reaction efficiency and controllability. Although it is illustrated as a preferable example, for example, further, impactor classification by a baffle plate,
Coarse particles are inevitably removed by using a relatively long supply pipe, or in the case of a raw material powder having a narrow particle size distribution width, a method without performing a classification operation can also be appropriately used. The feeding method prepared by any method can be used without any particular limitation.

In the present invention, examples of the flame raw material and its generation / utilization method include liquefied petroleum gas such as hydrogen, methane, butane, and acetylene, various combustible gases such as ammonia, and combustion-supporting gases such as oxygen. Is preferably used, but further, a plasma flame by ionization of an inert gas such as argon, or an arc flame generated between substances under a non-contact state to which a high voltage is applied, such as a coated rod arc, a Zab merge arc, and an inert gas arc. And the like can be used as appropriate and are not particularly limited, and flames prepared by any method can be used. Further, examples of the flame generator include a gas burner for liquefied gas or city gas, a gas welding gun, an arc welding gun, a thermal plasma device, and the like, but preferably, for example, a plurality of coaxially different inner diameters are used. A flame generator having a structure in which individual cylindrical tubes are combined is included as a component, and the raw material powder is supplied to one of the cylindrical tubes and the reaction gas is supplied to another cylindrical tube to An example is a device in which the raw material powder and the reaction gas are diffusively mixed near the tip of the cylindrical tube, and the nitriding reaction of the raw material powder proceeds in the gas phase in the presence of a flame.

Further, a raw material supply pipe having a structure in which a plurality of cylindrical pipes having different inner diameters are coaxially combined is provided, and a flammable gas consisting of C or H element which is a flame raw material or an inert gas for plasma generation is provided. In the double cylinder system in which oxygen, raw material powder and nitriding source are supplied from the outside, flame raw material gas, raw material powder and nitriding source (and oxygen) are mixed, and at the same time stable internal flame (and external flame) ) Or for the shape of the crater that produces a reducing combustion flame, the flame raw material gas is divided into several injection tubes and ejected from the outer circumference, and the oxygen etc. ejected from the inside is surrounded at a position closer to the supply source. A spud type that can obtain a good mixed state is preferably used. However, these are not particularly limited, and a high-pressure type gun type using a single flame raw material gas supply pipe, a ring type in which a large number of ejection ports are provided along the circumference of a ring-shaped flame raw material gas supply pipe. , An annular type in which a large diameter nozzle is radially divided and flame raw material gas and oxygen, etc. are jetted in parallel, a wall recess type in which a dead space where flame does not exist due to swirl control is provided by providing a step at the crater end, In addition to the wall recess type, the flame raw material gas supply pipe is divided into a main pipe and a sleeve fire pipe, a sectite type, and a ferrox type with a main pipe cross-sectional area more than 10 times the sleeve fire pipe cross-sectional area to reduce sleeve fire ejection speed ( Or Pian type), line type and shepherd type in which flames are arranged side by side in parallel, bluff body type that creates continuous igniting by creating a high-temperature vortex flow and recirculation zone by providing baffles in the unburned gas flow, mixed gas Radiant cup successive ignition collide with refractories red hot at high speed, also can be appropriately used, for example, be a flame prepared by any method can be used.

In the present invention, the raw material is a powder made of Al element, and the oxynitriding reaction is allowed to proceed in the presence of nitrogen, ammonia or an inert gas. As a mixture of powders consisting of elements,
By advancing the oxynitriding reaction in the presence of nitrogen, ammonia, or an inert gas, a powder containing the above Al, O and N elements can be obtained. Here, regarding the material system of the powdery raw material described as "powder composed of Al element", the sphericity produced by the atomizing method of aluminum metal powder of arbitrary particle diameter, water / gas / centrifuge Highly efficient vapor phase synthesis / Al powder group is preferably used.
Chlorides such as ₃ and the like, alkoxide raw materials such as aluminum isopropoxide (chemical formula Al (iso-OC ₃ H ₅ ) ₃ ), aluminum acetylacetonate (chemical formula Al
Β-diketone complexes such as (iso-C ₅ H ₇ O ₂ ) ₃ ),
Examples thereof include low boiling point gas phase synthesis raw materials such as alkylmetals such as trimethylaluminum (chemical formula Al (CH ₃ ) ₃ ), but there is no particular limitation.

Further, "a powder composed of Al and O elements,
Regarding the material system of the powdery raw material described as "a mixture of powders composed of C element", first of all, as "the powder composed of Al and O elements", a commercially available buyer method / improved Bayer method /
Alumina powders manufactured by the alkoxide method, ammonium dawsonite method, vapor phase method, etc. are preferable, but α, γ, θ, κ Al ₂ O ₃ multisystem (intermediate alumina), AlOOH Acetylacetonate, a hydroxide precursor represented by the chemical formula Al and (OH) ₃ (chemical formula Al
(C ₅ H ₇ O ₂ ) ₃ ), carbonate precursors such as ammonium dawsonite (chemical formula NH ₄ AlCO ₃ (OH) ₂ ), aluminum isopropoxide (chemical formula Al (i
Alkoxide raw materials such as so-OC ₃ H ₅ ) ₃ ), aluminum acetylacetonate (chemical formula Al (iso-C
Examples include β-diketone complexes such as ₅ H ₇ O ₂ ) ₃ ) and low boiling point gas phase synthesis raw materials such as alkylmetals such as trimethylaluminum (chemical formula Al (CH ₃ ) ₃ ), but are not particularly limited. Absent. Also, "powder composed of C element"
Examples of the carbon powder include carbon powder having an arbitrary particle diameter, high-purity vapor-phase synthesis / carbon powder such as carbon black and acetylene black, but are not particularly limited. The above raw material powder has a primary particle size range of 0.
It is required to be included in the range of 05 to 100 microns. The reason for this is that the characteristics of the raw material powder (mainly the particle size and shape) are reflected in the characteristics of the synthesized aluminum oxynitride powder.

Examples of the raw material powder feeding device include a screw type feeding device such as a kneader, a rotor type feeding device such as a twin-screw mill, and an air flow feeding for powder feeding. In the present invention, the ratio of fuel to oxygen is controlled so that carbon does not remain. As a method / apparatus for continuously or intermittently applying a high temperature to the powder synthesized in a flame, an ordinary electric furnace heating adopted in a thermal CVD method or the like is preferably used, but a combustion flame for heat treatment is used. It is possible to appropriately use flame reheating by providing a plurality of elements, use of plasma flame or arc flame, image furnace type heating, etc., and there is no particular limitation. Further, the heat treatment conditions are determined by the morphology and crystal phase of the powder immediately after being synthesized in the flame, and the heat treatment is not always necessary when the characteristics of the powder immediately after synthesis are satisfied. Examples of general conditions include nitrogen, ammonia, or an inert gas atmosphere. By the heat treatment, the ratio of the aluminum oxynitride multi-phase phase and its control can be remarkably improved.

The optical material and the raw material powder thereof according to the present invention emit light such as a high-pressure sodium arc tube which requires a material having excellent translucency at visible and infrared wavelengths, and at the same time having high heat resistance and abrasion resistance. It is preferably used as a raw material powder for producing a high-strength window material in a vacuum atmosphere such as a tube material, a high-temperature window material, and a space shuttle, but is not particularly limited. According to the present invention, the melting resistant material and its raw material powder have low activity with molten steel such as sialon, high temperature stability and oxidation resistance,
It is preferably used as a raw material for producing a refractory such as a crucible, which requires low wear due to molten steel flow (that is, high temperature mechanical strength), but is not particularly limited.

In the present invention, the composition is composed of an inorganic material.
Fill powder with resin-based raw material composed of organic material
As a composite material system to be produced, protection and insulation of semiconductor elements
A packaging material intended for
In addition, insulation materials, electrodes, conductive materials, electrorheological flow
Body, chemical mechanical polishing slurry, injection molding or casting molding
Examples of material systems such as any ceramic forming process raw material
Be done. Particles made of inorganic material that is the filler to be filled
As a material, it is often used in semiconductor packaging materials.
Silica or aluminum nitride is preferably exemplified, but examples
For example, Al₂ O₃ , SiC, Si₃ N_Four Other oxidation such as
Physical system, Au, Ag, Pd, Pt, Cu, Al, Au-P
Of course, metallic materials such as d can be applied, and there is no particular limitation.
Also, there is no limitation on crystallinity, either crystalline or amorphous.
It doesn't matter. About liquid material that is a medium
Is an aqueous system such as ion-exchanged water or distilled water, ethanol, etc.
In addition to organic non-aqueous systems,
Nol resin, bisphenol type cresol novolac
Functional epoxy resin, halogenated resin, etc.
Type resin materials and next-generation semiconductors that are liquid at room temperature
Resin materials often used as packaging materials for body elements
It is preferably exemplified, but there is no particular limitation.

In the present invention, as the substrate material and the raw material powder thereof, not a single LSI or IC, but a system LSI in which a plurality of elements are multi-layered and highly integrated, and the whole system is included in a single silicon chip, Substrate material for system-in-package, which aims at multi-functional multi-chip module or multi-functional multi-density at system level,
Alternatively, a power conversion power device (for example, a bridge diode for primary rectification of a switching power supply, a printer or an F
Motor driver ICs such as AX, DC / DC converter ICs for communication equipment or digital home appliances, high voltage ICs for inverter lighting, hybrid I such as TV / VTR
C and the like) are exemplified, but there is no particular limitation.

The present invention is directed to an aluminum oxynitride powder having an average particle size of submicron to several microns at the same time and a high sphericity, and a production technique capable of directly synthesizing the powder without crushing. It is possible to provide its use and manufacturing apparatus, and the powder of the present invention is most suitable as a raw material powder for an inorganic material such as an optical material or a melt resistant material. The characteristics of the aluminum oxynitride powder produced by the method of the present invention and the advantages of the production method are shown below. That is, the above-mentioned powder has a primary particle diameter range of 0.05-
Included in 100 micron, the product has small melt solidification and agglomeration, and at the same time has realized high dispersibility and / or non-angular outer shape of particles. In addition, the crystal phase can be produced by arbitrarily controlling from the multi-system phase of aluminum oxynitride to the AlN phase and the Al ₂ O ₃ phase.

[0028]

EXAMPLES Next, the present invention will be specifically described by way of examples, but the present invention is not limited to the following examples. (1) Method FIG. 1 schematically shows an example of a manufacturing apparatus configuration based on the present invention. Consisting of liquefied petroleum gas and oxygen-based chemical flame, nitrogen or ammonia nitriding source, and particulate raw material powder,
A gas phase (aerosol) manufacturing process was established. Reactor (Diffusion Burner Flame R
eactor is a transparent quartz tube (Quartz Tube)
e) and a diffusion flame type with a stainless steel double cylindrical tube,
The crater used was a spud-type. To the outer tube Flame source gas (hydrocarbon gas)
s) and feed the raw material powder (Raw Precur
Sor Powder), and a reaction gas system, here,
Nitrogen gas of NH ₃ (Nitriding Gas),
And O ₂ . In FIG. 1, first, an Al raw material powder is loaded into a fluidized bed aerosol generator (fluidized bed).
Transfer to Aerosol Generator and select the particle size of the raw material powder (Classificatio)
n), and the delivery route of the flame raw material gas to the oxygen ratio and the nitriding gas (Control of Nitriding Gas).
Inlet Position) and the like are adjusted to perform gas phase synthesis with internal flame (Inner Luminous Flame), products (Resultant Products).
in Gas Phase “Aerosol”) through a filter (Pump)
A configuration is adopted in which harmful gas and the like are removed by trapping. As an example of the basic reaction system applied to the chemical flame method, the direct nitriding method of Al powder was used here,
Of course, there is no problem in the reduction nitriding method.

As the Al raw material powder, a spherical powder having an average particle diameter of about 3 μm by the gas atomizing method was used. The fluidization was performed by a medium fluidized bed method, and glass beads having a diameter of 150 μm were used as a medium. The raw material powder was supplied with nitrogen gas at 3 liters per minute, and liquefied petroleum gas was supplied at 4 liters per minute. Oxygen gas, which is a control factor, is slightly reducing flame from the stoichiometric ratio with liquefied petroleum gas. It was adjusted to the side and 4 liters per minute. However, carbon is not generated excessively due to incomplete combustion. Further, ammonia gas for the oxynitriding reaction was adjusted and supplied from 0 liter to 3 liters per minute. (2) Results As described above, the vapor phase synthesis method has abundant control factors and high controllability of produced particles. here,
As an example, the results of controlling the reaction efficiency by adjusting the amount of the nitriding source supplied to the reaction system and adjusting the average particle diameter of the produced particles are shown. 2 and 3 show SEMs of an example of aluminum oxynitride powder according to the method of the present invention. Fig. 2 shows 3 liters of ammonia gas per minute, and Fig. 3 shows 0 liters per minute.
This is the result of manufacturing with a liter. As a result, from the starting particle size of 3 μm, the fineness was controlled to about 0.1 μm and the coarse particle size was controlled to about 10 μm. That is, it was possible to change from about 1/30 of the raw material powder to about 3 times. The generated particle size can be arbitrarily controlled by changing the raw material particle size in addition to the above synthesis conditions,
Since Al powders of sub-micron to several tens of microns are easily available as commercial products at present, a reasonable range of the primary particle size that can be synthesized is guaranteed to be 0.05 to 100 microns.

Therefore, first of all, at the stage (1) directly synthesized with only a flame (without heat treatment etc.), which is mainly required as a raw material powder in the technical field targeted by the present invention,
It is possible to manufacture a powder having a composition of 100% aluminum oxynitride (that is, there is no need for expensive heat treatment equipment at 1650 ° C. or higher and an extra heat treatment at a later stage). (2) Size of precursor raw material powder It is possible to achieve the generated particles and particle diameters of the average particle diameter held in the order of micron. (3) Highly dispersed state can be realized without coarsening of the powder at the stage of synthesis (that is, the pulverization step is unnecessary. A), (4) high sphericity can be achieved, (5) in particular, it is difficult to generate a solid fused or agglomerated state of the produced powder even though the direct nitriding of the metal Al powder is used. The effect of was achieved. Secondly, the generated particle size could be arbitrarily controlled under the condition that the supply amount of the nitriding source was easily adjustable. In addition to this, the nitriding gas supply method is premixed with the raw material powder and oxygen gas, or is supplied later to the center where the internal flame is burning, and the supply path is changed to supply particles with different reaction principles. It became possible to control the diameter and the generation phase.

[0031]

As described in detail above, according to the present invention,
(1) Direct synthesis is possible with existing manufacturing equipment constructed in the field of filler powder, without using expensive heat treatment equipment and crushing process. (2) Suppressing grain growth of precursor raw material powder, powder It is possible to produce a powder free from coarsening / aggregation (fusion) of the body (that is, the generated particle diameter can be arbitrarily controlled under the condition that the precursor raw material powder diameter can be easily adjusted), (3) above Satisfies the powder characteristics and at the same time achieves a high sphericity that cannot be expected from conventional products. (In the past, the grinding process was essential for aluminum oxynitride powder, and there was only powder with angular and highly anisotropic shape. ), (4) In particular, as a raw material for optical system materials that utilize the translucency of an isotropic crystal structure, or melt-resistant materials that utilize high thermal shock resistance or low wettability and low reactivity with molten steel, etc. Achieve the required particle size and sphericity at the same time, especially The particle growth of the raw material powder is suppressed and the range of the primary particle diameter is included in 0.05 to 100 microns, the melt coagulation and agglomeration of the product are small, and the high dispersibility and / or the outer shape of the particles are not angular. It is possible to provide a new raw material powder that simultaneously achieves the above effect.

[Brief description of drawings]

FIG. 1 shows a schematic view of an example of the configuration of a manufacturing apparatus according to the present invention.

FIG. 2 shows an SEM (in the case of 3 liters per minute of nitriding ammonia gas) of an example of an aluminum oxynitride powder produced in the example.

FIG. 3 shows an SEM (in the case of 0 liters per minute of ammonia gas for nitriding) of an example of aluminum oxynitride powder produced in the example.

Claims (6)

[Claims] 1. An aluminum oxynitride powder produced by subjecting a raw material powder to an oxynitriding reaction in a gas phase in the presence of a flame, the oxynitriding reaction being applied in a gas phase under atmospheric pressure. The particle growth of the raw material powder is suppressed, and the range of the primary particle diameter is 0.05 to 1
A powder containing Al, O, and N elements, which is contained in 00 micron, has small melting and solidification and aggregation of the product, is highly dispersed, and has a non-angular outer shape. 2. The oxygen concentration in the flame is adjusted so that Al element ÷
The ratio of O element is contained in 0.67 to 5.3, and Al element ÷
The powder containing Al, O and N elements according to claim 1, characterized in that the ratio of N elements is contained in the range of 1-27. 3. A flame of a combustible gas, a combustion flame of a mixed gas of a combustible gas and oxygen, a reducing combustion flame in which the ratio of the combustible gas and oxygen is less than the complete combustion ratio, and the plasma of an inert gas. The Al, O, and O according to claim 1, characterized in that its thermal energy and reducing power are utilized in the presence of a flame or a flame selected from arc flames generated between substances in a non-contact state. Powder containing N element. 4. The Al according to claim 1,
A method for producing a powder containing O and N elements, the method comprising: forming a raw material powder in a vapor phase in a dispersed state; directly nitriding or reductive nitriding the raw material powder in a vapor phase in the presence of a flame. A method for producing a powder containing Al, O and N elements, which comprises the steps of subjecting to an oxynitriding reaction to produce an oxynitride, or these steps and the step of heat-treating the oxynitride. . 5. The Al according to claim 1,
An apparatus for use in a method for producing a powder containing O and N elements, comprising a flame generating device, a raw material powder supplying device, and a reaction gas supplying device as constituent elements, and generating a flame. In the device, the raw material powder and the reaction gas are diffused and mixed,
A manufacturing apparatus characterized in that a ratio of a fuel and an oxygen amount is controlled so that carbon does not remain so that an oxynitriding reaction of a raw material powder proceeds in a gas phase in the presence of a flame. 6. A flame generating device having a structure in which a plurality of cylindrical tubes having different inner diameters are coaxially combined is included as a constituent element, and the raw material powder is supplied to any one of the cylindrical tubes and is supplied to another cylindrical tube. Oxynitriding the raw material powder by controlling the ratio of the amount of fuel and oxygen so that the raw material powder and the reaction gas are diffused and mixed in the vicinity of the tip of the cylindrical tube and no carbon remains by supplying the reaction gas. The manufacturing apparatus according to claim 5, wherein the reaction is allowed to proceed in a gas phase in the presence of a flame.