JPH0753282A - Coated high pressure type boron nitride quasi-fine particle, sintered body of the same and production thereof - Google Patents

Abstract

PURPOSE:To produce a high performance coated high pressure type boron nitride sintered body which has uniform, dense, firmly sintered and highly controlled fine structure and is formed from coated high pressure type boron nitride quasi-fine particles. CONSTITUTION:Powdery core particles consisting of quasi-fine particles of the high pressure type boron nitride having >10mum average particle size determined by using the frequency distribution on the volume basis are dispersed in air. This dispersed powdery core particles in such a dispersed state that the dispersity beta is >=80% are allowed to come into contact with or to collide with a coating film forming material precursor to coat the surface of each of the core particles with the coating film forming material. The coated high pressure type boron nitride particles thus obtained, alone or together with a binder, are sintered under such sintering conditions of pressure and temp. that the high pressure type boron nitride is thermodynamically stable, or under the sintering conditions of pressure and temp. of <2000MPa and and <=1850 deg.C respectively. Under the latter conditions, the high pressure type boron nitride is not thermodynamically stable, however it is metastable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating obtained by coating particles of quasi-fine particle core particle powder composed of high-pressure type boron nitride quasi-fine particles or particles of core particle powder mainly composed of quasi-fine particles with a coating forming substance. High-pressure type boron nitride quasi-fine particles, and a dense, high-hardness, highly controlled microstructure-controlled high-pressure type boron nitride quasi-fine particle sintered body obtained by sintering the coated high-pressure type boron nitride quasi-fine particles, and Regarding the manufacturing method.

[0002]

2. Description of the Related Art In recent years, high pressure type boron nitride sintered bodies have been vigorously researched and developed with the aim of miniaturizing and homogenizing their structures. Is relatively large, for example, a high-pressure type boron nitride quasi-fine particle having a particle diameter of more than 10 μm is very effective. For example, a wear-resistant sintered body that takes advantage of the characteristics of ultra-high-hardness high-pressure boron nitride is used to burn quasi-fine-particle-dispersed high-pressure boron nitride quasi-fine particles in which a relatively large amount of high-pressure boron nitride quasi-fine particles are dispersed. It can be manufactured by binding, but in this case, the high-pressure boron nitride quasi-fine particles as the raw material are extremely important. The high-pressure type boron nitride quasi-fine particle sintered body in which the high-pressure type boron nitride quasi-fine particle is dispersed is a quasi-fine particle dispersion by the close sintering of the high-pressure type boron nitride quasi-fine particle and the microstructure around it without defects or pores. The effect is remarkable. However, since the high-pressure type boron nitride is extremely difficult to sinter, the presence of a sintering aid or a binder that promotes the sintering of the high-pressure type boron nitride quasi-fine particles and the surrounding microstructure is indispensable. Conventionally, the addition of such a sintering aid or binder has been carried out exclusively by the powder mixing method.
However, in the powder mixing method, mixing of impurities during mixing is inevitable, and in principle, there is a limit to homogenization of the structure, and the particles of the sintering aid and the binder are relatively extremely fine. Even if there is an ideal uniform mixing, that is, it is extremely difficult to uniformly disperse the powder particles of the sintering aid and the binder in the high-pressure type boron nitride quasi-fine particles. Even if this uniform dispersion is realized, the meaning of uniformity is limited because the powder particles of the sintering aid and the binder are mixed in particle units. Especially when the amount is relatively small, uneven distribution is inevitable.

In reality, in many cases, high-pressure type boron nitride quasi-fine particles are concentrated or powder particles of a sintering aid or a binder are aggregated to form a lump in the high-pressure type boron nitride quasi-fine particle sintered body. It exists or is unevenly distributed in the high pressure type boron nitride quasi fine particle sintered body, and the performance of the high pressure type boron nitride quasi fine particle sintered body is significantly deteriorated. Therefore, it is necessary to surely distribute the sintering aid and the binder in each of the high-pressure type boron nitride quasi-fine particles. Moreover, because of the close sintering of the high-pressure type boron nitride quasi-fine particles and the surrounding microstructure, a highly controlled and uniform coating on the surface of the high-pressure type boron nitride quasi-fine particles, that is, the individual high-pressure type boron nitride quasi-fine particles It is required that all the high-pressure boron nitride quasi-fine particles have a uniform coating with no uncoated portion left on the surface of the above. Moreover, this highly controlled and uniform coating is required to have a uniform coating free from uncoated portions as long as the particle size is large. Thus, the production of coated high-pressure type boron nitride quasi-fine particles by the highly controlled and uniform coating, and the production of high-performance coated high-pressure type boron nitride quasi-fine particle sintered body using the coated high-pressure type boron nitride quasi-fine particles are possible. Strongly desired.
Various methods such as a vapor phase method and a wet plating method can be considered as a method of coating the high pressure type boron nitride quasi-fine particles with a coating forming substance. Among them, an inorganic material or a metal material is formed on the surface of the powder particles by the vapor phase method. In principle, the method of coating a coating-forming substance such as a film with various forms such as a film is (1) easy to control the atmosphere, and (2) there is basically a limitation in the selection of the coating-forming substance. However, it is possible to coat various kinds of substances such as simple metal substances including active metals, alloys, nitrides, carbides, borides and oxides. (3) The target substance can be coated with high purity. (4 ) It is possible to arbitrarily control the coating amount of the coating forming substance,
There are major features that cannot be achieved by other coating methods.

However, due to the following reasons, the above-mentioned highly controlled and uniform coating cannot be achieved by various coating apparatuses and coating methods proposed as known techniques. For example, according to the apparatus / method disclosed in Japanese Patent Laid-Open No. 58-31076, particles of core particle powder are put in a container installed in a PVD apparatus and the container is vibrated by an electromagnetic method. The core particles in the container while rolling the PV
Cover by method D. Further, according to the device disclosed in JP-A-61-30663, particles of core particle powder are put into a container installed in a PVD device, and the container is vibrated by a mechanical method. It is said that the core particles in the container can be coated by the PVD method while rolling. However, in the apparatus or method for coating while rolling the particles of the core particle powder by the vibration of these containers,
Actually, the particles of the quasi-fine particle core particle powder or the particles of the core particle powder mainly consisting of the quasi-fine particles roll in the overlapping state while being in contact with each other many times and cannot be coated in a single particle state. It was The apparatus and method disclosed in Japanese Patent Application Laid-Open No. 3-153864 discloses placing particles in a rotating container having a barrier and / or unevenness on the inner surface, and coating the surface of core particles by vapor deposition while rotating the rotating container. In such an apparatus or method, the particles of the quasi-fine particle core particle powder or the particles of the core particle powder mainly consisting of quasi-fine particles are in contact with each other in multiple layers. There was no change in the overlapping state, and many particles were only lightly stirred while in contact with each other, and could not be coated in the single particle state.

Japanese Patent Laid-Open No. 58-141375 discloses a depositing substance produced by a chemical reaction of a reaction gas by suspending a powder placed in a reaction gas atmosphere by the flow of the reaction gas and the action of gravity. Discloses a device for coating the surface of powder. Further, Japanese Patent Application Laid-Open No. 2-43377 discloses a method in which particles are fluidized under a reduced pressure while a thermochemical reaction treatment is performed to perform coating. or,
Japanese Unexamined Patent Publication (Kokai) No. 64-80437 discloses a method in which agglomerates of core particle powder are broken down and fluidized by low and high frequency synthetic sound waves to cover them. However, in the method or apparatus utilizing the fluidized bed of the particles of the quasi-fine particle core particle powder or the particles of the core particle powder mainly consisting of the quasi-fine particles by these air flows and vibrations, all the core particles are the same as a single particle. It is virtually impossible to independently flow and float in a state, and it was not possible to eliminate the uneven coating of each particle due to the shadow of the particles. Japanese Unexamined Patent Publication No. 54-153789 discloses an apparatus for coating a metal by dropping a powder material in a vacuum container in which vapor of metal is generated. Also, JP-A-60-
Japanese Patent Publication No. 47004 discloses a method in which a monomer gas and powder particles are introduced into a high-frequency plasma region in a vacuum chamber to form an organic coating film by plasma polymerization. Just by introducing them as in these devices or methods, the particles of the quasi-fine particle core particle powder or the particles of the core particle powder mainly consisting of the quasi-fine particles form an aggregate that is not in a single particle state and fall. Then, the shadows of the particles were formed and uneven, the particles inside the agglomerates were not coated at all, or a difference in the coating amount was caused as compared with those coated with a single particle.

In JP-A-62-250172, as a pretreatment, powder subjected to jet mill treatment is retained in a reduced-pressure heat treatment chamber, where after heat treatment is performed, the powder is fed into a sputtering chamber with a powder feeder. An apparatus and a method are disclosed in which the target is introduced by natural falling and the target is naturally dropped into a vertically-arranged cylindrical sputtering chamber to cover the target. Further, in Japanese Patent Application Laid-Open No. 2-153068, as a pretreatment, powder subjected to jet mill treatment is retained in a reduced-pressure heat treatment chamber, where after heat treatment is performed, a sputtering source in a sputtering chamber is used with a powder feeder. There is disclosed an apparatus and a method in which a powder is introduced into a rotating container in which is charged and sputtering is performed in a state where the container is rotated. In these devices and methods, in the heating step before coating, there is a step of retaining the particles of the quasi-fine particle core particle powder subjected to jet mill treatment or the particles of the core particle powder mainly composed of quasi-fine particles. Due to the retention of the powder, agglomerates that are not in the single particle state are formed again, and eventually the agglomerates are not in the single particle state in the coating process. As described above, in all of the conventionally known techniques, the particles of the quasi-fine particle core particle powder which is a high-pressure type boron nitride quasi-fine particle or the particles of the core particle powder mainly composed of quasi-fine particles are coagulated while being in contact with each other. It was not possible to produce coated high-pressure boron nitride quasi-fine particles which were subjected to a coating treatment in the state of aggregates, and for this reason each particle was provided with a highly controlled and uniform coating.

That is, the high-pressure type boron nitride quasi-fine particles are not as strong in cohesive force as the high-pressure type boron nitride fine particles, but are still particles of the quasi-fine particle core particle powder or particles of the core particle powder mainly composed of quasi-fine particles. However, we could not realize the single particle state in which each of them exists as a unit. Therefore, the coating of the high-pressure type boron nitride quasi-fine particle surface with the coating forming substance by the above vapor phase method,
Where it was blocked by other quasi-fine particles, an uncoated portion was left on the surface of the high-pressure boron nitride quasi-fine particles. Despite the demand for highly controlled and uniform coating as described above, the high-pressure type boron nitride quasi-fine particles are greatly affected by this level of cohesive force, which is a very serious problem. That is the reality.

[0008]

Accordingly, in reality, the high-pressure type boron nitride quasi-fine particles to be coated have a mean particle size of more than 10 μm, and are particles of quasi-fine particle core particles or core particles mainly composed of quasi-fine particles. A highly controlled uniform coating of powder particles, that is, a uniform coating in which the uncoated portion of the surface of each high-pressure boron nitride quasi-fine particle does not remain, and this uniform coating is used for all high-pressure nitriding. A coating made of boron quasi-fine particles is required. Moreover, for this highly controlled and uniform coating, it is strongly demanded to produce coated high-pressure type boron nitride quasi-fine particles which have a larger particle size and are more uniform without an uncoated portion. The present invention relates to a substance that serves as a binder and / or a sintering aid for particles of quasi-fine particle core particle powder that is high-pressure type boron nitride quasi-fine particle or particles of core particle powder that mainly consists of quasi-fine particles. Is a highly controlled uniform coating, that is, a uniform coating in which the uncoated portion of the surface of the individual high-pressure boron nitride quasi-fine particles does not remain, and this uniform coating is used for all individual high-pressure types. For the particles made of quasi-fine particles of boron nitride and having a large particle diameter, coated high-pressure boron nitride quasi-fine particles having a uniform coating with less uncoated portion, and the coated high-pressure particles An object of the present invention is to provide a coated high-pressure type boron nitride quasi-fine particle sintered body using type boron nitride quasi-fine particles and a method for producing the same.

[0009]

In order to solve the above-mentioned problems, as a result of intensive studies by the present inventor, it was found that high-pressure boron nitride quasi-fine particles are quasi-fine core particles, or mainly quasi-fine particles. The core-forming powder has a uniform coating with a highly controlled coating material, that is, a uniform coating in which no uncoated portion of the surface of each high-pressure boron nitride quasi-fine particle remains, and For all individual high-pressure type boron nitride quasi-fine particles with a large coating and a large particle diameter, in order to obtain a uniform coating with no uncoated portion, (1) volume High-dispersion core particles having an average particle size of more than 10 μm and particles of 20 μm or less in the air mainly in a single particle state in a standard frequency distribution. If the dispersity β is 80% or more, In the coating start region of the coating space in a highly dispersed state, or (2) in the volume standard frequency distribution, the average particle diameter exceeds 20 μm and the particles of the core particle powder of 50 μm or less are mainly in a single particle state in the air. Particles of the existing highly dispersed core particle powder / particles of this core particle powder in the gas mixture are added in the coating start region of the coating space in a highly dispersed state where the dispersity β is 90% or more, or (3) Highly-dispersed core particles having an average particle diameter of more than 50 μm and particles of 300 μm or less in the air mainly in a single particle state in a volume-based frequency distribution. The particles of the particle powder are provided in the coating start region of the coating space in a highly dispersed state where the dispersity β is 95% or more, or Particles Particles are mainly present in the air in the form of single particles. The core particles of the particle powder Chishin particle powder particle-gas mixture,
In the coating start region of the coating space in a highly dispersed state where the dispersity β is 97% or more, or (5) the core particle powder particles having an average particle diameter exceeding 800 μm in the volume standard frequency distribution are mainly single particles. Particles of highly dispersed core particles powder existing in the air in the state
The particles of this core particle powder in the gas mixture have a dispersity β of 9
It has been found that the coating must start in the coating start region of the coating space in the highly dispersed state, which is above 9%.

More specifically, (I) the particles of the high-dispersion type boron nitride are mainly present in the air in the form of a single particle. However, even if it does not stay, it tends to reaggregate mainly due to turbulent agglomeration with the passage of time, and once reaggregated, it is dispersed by a dispersion treatment means having a particularly high dispersibility like the aggregate before the dispersion treatment. If this is not done, it is difficult to break this re-aggregation state and disperse it to a high degree, that is, to re-disperse it into a single particle state of each unit. Therefore, (1) in the volume standard frequency distribution, the average particle diameter is 20μ over 10μm
Particles of core particle powder having a particle diameter of m or less are mainly present in the air in the form of a single particle. In the high dispersion state as described above, or (2) a high dispersion in which particles of the core particle powder having an average particle size of more than 20 μm and 50 μm or less in the volume standard frequency distribution are mainly present in the air in a single particle state. The particles of this core particle powder in the particle / gas mixture of the core particle powder are in a highly dispersed state with a dispersity β of 90% or more, or (3)
The volume-based frequency distribution has an average particle size of more than 50 μm
Particles of core particle powder having a particle size of 0 μm or less are mainly present in the air in a single particle state. Particles of highly dispersed core particle powder / particles of this core particle powder in a gas mixture have a dispersity β of 95%. In the high dispersion state as described above, or (4) the high dispersion in which particles of the core particle powder having an average particle size of more than 300 μm and 800 μm or less in the volume standard frequency distribution are mainly present in the air in a single particle state. Particles of this core particle powder in the particle / gas mixture of the core particle powder are either in the coating start region of the coating space in a highly dispersed state where the dispersity β is 97% or more, or (5) volume standard frequency distribution The particles of the core particle powder having an average particle size of more than 800 μm mainly exist in the air in the form of a single particle. The particles of the highly dispersed core particle powder and the particles of the core particle powder in the gas mixture are dispersed. Degree β
It is necessary to lead to the coating start region of the coating space in a highly dispersed state in which the ratio is 99% or more, and (II)
Disintegrating the agglomerates composed of the particles of the core particle powder and dispersing them in the air at a very high dispersity according to the particle diameter, -a dispersion treatment means group having the above particularly high dispersion performance is required. The present invention was discovered by finding out that there is.

That is, according to the present invention, a core-forming powder composed of quasi-fine particles of high-pressure boron nitride is charged into a coating space, and a precursor for forming a coating and / or a coating-forming substance in a vapor phase is produced through a gas phase. A coated high-pressure type boron nitride quasi-fine particle obtained by contacting and / or colliding with a particle of the core particle powder, and coating the surface of the particle of the core particle powder with a coating forming substance, (A) The final processing means of the semi-fine particle high dispersion processing means group is
(A) Dispersing means for dispersing the particles of the core particle powder in the air, and (b) Low dispersion in a mixture of the particles of the core particle powder and the gas in which the particles of the core particle powder are dispersed in the air. Highly dispersed core particle powder particles that separate the core particle powder part and select the particle / gas mixture of highly dispersed core particle powder in which the particles of the core particle powder mainly exist in the air in a single particle state. The gas dispersion selection means and the particles of the highly dispersed core particle powder, and the low dispersion core particle powder portion selectively separated by the gas mixture selection means are the final dispersion means of the dispersion means in the quasi-fine particle high dispersion treatment means group. And / or feedback means for conveying to the processing means before the final dispersing means, particles of highly dispersed core particle powder,
The average particle diameter is 10 μm in the volume-based frequency distribution by means of the quasi-fine particle high dispersion treatment means group selected from the gas mixture selecting means.
a dispersion step of dispersing particles of the quasi-fine particle core particle powder exceeding m or particles of the core particle powder mainly consisting of quasi-fine particles into the air to form a particle / gas mixture of the highly dispersed core particle powder; ) The particles of the core particle powder dispersed in the dispersion step have a dispersity β of 80% or more when the average particle size is more than 10 μm and 20 μm or less, and a dispersity β of 90% or more when the average particle size is more than 20 μm and 50 μm or less, 300 over 50 μm
When it is less than μm, the dispersity β is 95% or more, 300 μm
When it exceeds 800 μm and the dispersity β is 97% or more,
When it exceeds 800 μm, the coating means comprises a coating step of starting the coating by contacting and / or colliding with the coating material precursor in the coating start region of the coating space in a dispersed state with the dispersity β of 99% or more. The present invention relates to prepared coated high pressure type boron nitride quasi-fine particles.

The present invention also provides a coated high-pressure type nitriding material, wherein the coated high-pressure type boron nitride quasi-fine particles form an agglomerate in a contact state via a coating material of the coated high-pressure type boron nitride quasi-fine particles. Crush and / or break up aggregates of boron quasi-fine particles
Alternatively, a step of crushing and crushing the coated high-pressure type boron nitride quasi-fine particle aggregates to be crushed, and / or selecting the coated high-pressure type boron nitride quasi-fine particle aggregates and the high-pressure type boron nitride quasi-fine particles coated with primary particle units The present invention relates to coated high-pressure boron nitride quasi-fine particles, characterized by being prepared through a selective separation step of separating. Further, the present invention uses a molten salt bath in which particles of core particle powder composed of quasi-fine particles of high pressure type boron nitride to be coated with the above-mentioned coating forming substance or particles of core particle powder mainly composed of quasi-fine particles are used. The present invention relates to high pressure type boron nitride quasi-fine particles which are particles of a quasi-fine particle core particle powder further coated with a coating material derived from the immersion method by a dipping method or particles of a core particle powder mainly composed of quasi-fine particles.

Further, according to the present invention, the coated high-pressure type boron nitride quasi-fine particles have a volume-based frequency distribution and an average particle size of 10 μm.
The core particle powder having a diameter of more than 20 μm and not more than 20 μm is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to form a particle / gas mixture of the highly dispersed core particle powder, and the dispersion of the particles of the core particle powder. Of the quasi-fine particle high-dispersion processing means group having a dispersion performance of making the degree β 80% or more, or the core particle powder having an average particle diameter of more than 20 μm and 50 μm or less in the volume-based frequency distribution, A group of quasi-fine particle high-dispersion treatment means having a dispersibility in which a particle / gas mixture of highly dispersed core particle powder is obtained by dispersing in the air by the final treatment and the degree of dispersion β of the particles of the core particle powder is 90% or more. , Or a particle / gas of a highly dispersed core particle powder, in which a core particle powder having an average particle diameter of more than 50 μm and not more than 300 μm in a volume-based frequency distribution is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group. As a mixture, its core particles powder Beyond a quasi particle group of means for high dispersion treatment, or an average particle diameter of 300μm on a volume basis the frequency distribution having a dispersing performance that the dispersity β of the particles and 95% 80
The core particle powder having a particle size of 0 μm or less is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to form a particle / gas mixture of the highly dispersed core particle powder, and the degree of dispersion β of the particles of the core particle powder Of 97% or more of quasi-fine particle high-dispersion treatment means having a dispersion performance, or a volume-based frequency distribution with an average particle diameter of 80
The core particle powder exceeding 0 μm is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to form a particle / gas mixture of the highly dispersed core particle powder, and the degree of dispersion β of the particles of the core particle powder A dispersion process using a group of quasi-particulate high-dispersion treatment means having a dispersion performance of 99% or more is provided, and the particle-gas mixture of the highly-dispersed core particle powder dispersed by the quasi-fine particle high-dispersion treatment means group is directly applied to the coating step. A hollow member unavoidable for transportation from a discharging part that discharges or discharges a particle / gas mixture of highly dispersed core particle powder dispersed by a quasi-fine particle high dispersion treatment means group between the dispersing step and the coating step. , A high-dispersion core particle powder which is conveyed through one or more members selected from an intermediate member made of a member that forms a hollow and a pipe, and / or dispersed in the air with the above-mentioned dispersion performance. Body particle / gas mixture In-air dispersion maintaining means for maintaining the air-dispersed state of the particles in the compound, enhancing the air-dispersed state of the particles in the particles / gas mixture of the highly dispersed core particle powder dispersed in the air with the above-mentioned dispersion performance Air dispersion promoting means, separating low-dispersion core particle powder portion of a mixture of core particle powder particles and gas, and the core particle powder particles mainly exist in the air in a single particle state. High-dispersion core particle powder of high-dispersion core particle powder / gas mixture for selecting high-dispersion core particle powder particle / gas mixture selection prepared by transporting through one or more means It relates to boron quasi-fine particles.

Further, according to the present invention, the coated high-pressure type boron nitride quasi-fine particles have a volume-based frequency distribution and an average particle size of 10 μm.
The core particle powder having a diameter of more than 20 μm and not more than 20 μm is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to form a particle / gas mixture of the highly dispersed core particle powder, and the dispersion of the particles of the core particle powder. Of the quasi-fine particle high-dispersion processing means group having a dispersion performance of making the degree β 80% or more, or the core particle powder having an average particle diameter of more than 20 μm and 50 μm or less in the volume-based frequency distribution, A group of quasi-fine particle high-dispersion treatment means having a dispersibility in which a particle / gas mixture of highly dispersed core particle powder is obtained by dispersing in the air by the final treatment and the degree of dispersion β of the particles of the core particle powder is 90% or more. , Or a particle / gas of a highly dispersed core particle powder, in which a core particle powder having an average particle diameter of more than 50 μm and not more than 300 μm in a volume-based frequency distribution is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group. As a mixture, its core particles powder Beyond a quasi particle group of means for high dispersion treatment, or an average particle diameter of 300μm on a volume basis the frequency distribution having a dispersing performance that the dispersity β of the particles and 95% 80
The core particle powder having a particle size of 0 μm or less is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to form a particle / gas mixture of the highly dispersed core particle powder, and the degree of dispersion β of the particles of the core particle powder Of 97% or more of quasi-fine particle high-dispersion treatment means having a dispersion performance, or a volume-based frequency distribution with an average particle diameter of 80
The core particle powder exceeding 0 μm is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to form a particle / gas mixture of the highly dispersed core particle powder, and the degree of dispersion β of the particles of the core particle powder Prepared by performing a part or more of the dispersion step and a part or more of the coating step by the quasi-fine particle high dispersion treatment means group having a dispersion performance of 99% or more with a part or more of the space shared. The present invention relates to coated high pressure type boron nitride quasi-fine particles.

Further, according to the present invention, the coated high-pressure type boron nitride quasi-fine particles have a volume-based frequency distribution and an average particle size of 10 μm.
A core particle powder having a particle size of more than 20 μm and not more than m is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to obtain a particle / gas mixture of the highly dispersed core particle powder. A core particle powder having a spatial region with a dispersity β of 80% or more and a volume-based frequency distribution and an average particle size of more than 20 μm and not more than 50 μm is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group. As a particle / gas mixture of highly-dispersed core particle powder, the average particle size in the spatial region where the dispersity β of the particles of the core particle powder is 90% or more, and the volume-based frequency distribution,
A core particle powder having a particle size of more than 50 μm and not more than 300 μm is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to obtain a particle / gas mixture of the highly dispersed core particle powder. Spatial region where the dispersity β is 95% or more, and the average particle size in the volume standard frequency distribution is more than 300 μm and 80
The core particle powder having a particle size of 0 μm or less is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to form a particle / gas mixture of the highly dispersed core particle powder, and the degree of dispersion β of the particles of the core particle powder Of core particles having an average particle size of more than 800 μm in the spatial region and volume-based frequency distribution of 97% or more are dispersed in the air by the final treatment of the quasi-fine particle high-dispersion processing means group to obtain high-dispersion core particle powder. The particle / gas mixture of the body, and the degree of dispersion β of the particle of the core particle powder is 99% or more of the highly dispersed core particle powder in the space region / the particle of the core particle powder in the gas mixture. The coating start region of the coating space is located in the space region including the surface through which all particles pass, or the core particle powder having an average particle size of more than 10 μm and 20 μm or less in the volume standard frequency distribution is added to the quasi fine particle height. Disperse in the air by the final treatment of the dispersion treatment means group A particle-gas mixture highly dispersed core particles powder, the dispersity β of the particles in the powder of core particles 80%
Core particle powder having an average particle size of more than 20 μm and 50 μm or less in the above spatial region and volume standard frequency distribution is dispersed in the air by the final treatment of the quasi-fine particle high-dispersion processing means group to obtain highly dispersed core particle powder. In a spatial region in which the degree of dispersion β of the particles of the core particle powder is 90% or more, and the average particle diameter in the volume standard frequency distribution is more than 50 μm and 300 μm or less, quasi-fine particles By the final treatment of the high-dispersion treatment means group, it is dispersed in the air to obtain a particle / gas mixture of highly dispersed core particle powder, and the degree of dispersion β of the particles of the core particle powder is 95.
% Core particles having an average particle size of more than 300 μm and 800 μm or less in a spatial region and volume standard frequency distribution,
A space region in which the particles / gas mixture of highly dispersed core particle powder is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group, and the degree of dispersion β of the particles of the core particle powder is 97% or more,
A core particle powder having a volume-based frequency distribution and an average particle diameter of more than 800 μm is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to form a particle / gas mixture of the highly dispersed core particle powder, and the core thereof. The coating start region of the coating space is located in a space region including a surface through which all the particles to be recovered by the recovery unit of the recovery means pass, within the space region in which the dispersity β of the particles of the particle powder is 99% or more. The present invention relates to coated high pressure type boron nitride quasi-fine particles which are at least coated.

[0016] Furthermore, the present invention uses, the particle size distribution of the particles in the powder of core particles is, when the average particle diameter is D _M, by volume frequency distribution ([D _M / 5,5D _M], ≧ 90%). Furthermore, the present invention provides the above coated high pressure type boron nitride quasi fine particles or a mixture containing the same at 2000 M
High-pressure boron nitride, which is sintered at a pressure of Pa or higher and at a high temperature, or the coated high-pressure boron nitride quasi-fine particles or a mixture containing the particles described in the above claims is pressurized at a pressure of less than 2000 MPa and does not exceed 1850 ° C. Is not thermodynamically stable, but sinters under a sintering condition of metastable pressure and temperature, or the volume of the coated high-pressure boron nitride quasi-fine particles and the binder is 1 to 1 90: 99 ~
A mixture of 10 parts, the binder is 2000M
High-pressure type boron nitride particles which do not exceed 1850 ° C. at a pressure of less than Pa are sintered to a density of 85% or more under thermodynamically metastable conditions. The above mixture is subjected to a pressure of less than 2000 MPa and a temperature of more than 1850 ° C. The present invention also relates to a method for producing a coated high-pressure type boron nitride quasi-fine particle sintered body which is not thermodynamically stable but is sintered under a metastable pressure / temperature sintering condition. The present invention also relates to a coated high-pressure type boron nitride quasi-fine particle sintered body produced by the method for producing a coated high-pressure type boron nitride quasi-fine particle sintered body described above.

Thus, according to the present invention, particles of core particle powder composed of high-pressure type boron nitride quasi-fine particles or particles of core particle powder mainly composed of quasi-fine particles, the surface of which is coated. The mixture coated with the forming material or a mixture containing the same particles is sintered at a pressure of 2000 MPa or higher and a high temperature, or the particles or a mixture containing the particles is
Pressure less than 2000 MPa and not exceeding 1850 ° C.,
Although the high-pressure type boron nitride is not thermodynamically stable, it is sintered under sintering conditions of metastable pressure and temperature, or the volume of the coated high-pressure type boron nitride quasi-fine particles and the binder is 1 to 1.
This binder is a mixture in the ratio of 90:99 to 10, and the binder has a density of 85 under the condition that the high pressure type boron nitride particles having a pressure of less than 2000 MPa and not exceeding 1850 ° C. are thermodynamically metastable.
% Of the above mixture, which is to be sintered to 2000% or more.
A high-pressure type boron nitride having a pressure of less than MPa and a temperature of not more than 1850 ° C. is not thermodynamically stable, but is sintered under a metastable pressure / temperature sintering condition to produce a sintered body of high-pressure type boron nitride particles. At that time, as the high-pressure type boron nitride quasi-fine particles whose surface is coated with a coating-forming substance, a coating-forming substance precursor and / or a vapor-forming coating-forming substance precursor produced through a gas phase by a gas phase method, The particle / gas mixture of the highly dispersed core particle powder consisting of the quasi-fine particles dispersed in the air by the final treatment means of the quasi-fine particle high dispersion treatment means group, in the coating start region of the coating space, the highly dispersed core particle powder Of the core particle powder in the particle / gas mixture of the above, the degree of dispersion of the particles is set to the above value according to the particle size of the quasi-fine particles, and the particles are joined and contacted and /
Or, by using a high-pressure type boron nitride quasi-fine particle surface coated with a coating forming substance by collision, there is no unsintered part of the high-pressure type boron nitride particle surface, which has not been obtained so far, and is uniform. It was possible to obtain a high-performance high-pressure boron nitride sintered body having a highly controlled microstructure that was densely and strongly sintered. Then, in the preparation of the above-mentioned coated core particles, the coating-forming substance precursor is in a gas phase state composed of atoms, molecules, ions, clusters, atomic clusters, molecular clusters, cluster ions, or has just been produced through a gas phase. By initiating contact and / or collision with the high-dispersion high-pressure boron nitride quasi-fine particles in the highly dispersed state, the coating forming substance is strongly bound to the surface of each core particle in the primary particle state, and as a result, It is possible to produce coated high pressure type boron nitride quasi-fine particles in which the surface of the core particle powder is coated with the coating forming substance in single particle units.

As described above, in the present invention, the coated high-pressure type boron nitride quasi-fine particles are sintered under the pressure of 2000 MPa or more and at the high temperature under the sintering condition in which the high-pressure type boron nitride is thermodynamically stable. In this case, the coated high-pressure type boron nitride quasi-fine particles are the ones in which the high-pressure type boron nitride particles that are in contact with each other are directly bonded to each other by directly breaking through the coating, resulting in an extremely uniform and dense sintered body. is there.
Further, in the present invention, the coated high-pressure type boron nitride quasi-fine particles may be applied to the high-pressure type boron nitride itself or with a binder at a pressure of less than 2000 MPa and a high-pressure type boron nitride not exceeding 1850 ° C., which is not thermodynamically stable but metastable.・ In the case of sintering under the temperature sintering conditions, even if the high-pressure type boron nitride quasi-fine particles contact each other, the particles do not directly bond with each other, but the coated high-pressure type boron nitride quasi-fine particles directly contact each other. There is always a coating material that serves as a binder or a sintering aid around the high-pressure boron nitride quasi-fine particles except where it is used, and the obtained sintered body is uniform and dense with no unsintered parts. And has a highly sintered microstructure that is strongly sintered.

Before describing the present invention in detail below, the terms used in the present specification will first be defined, and if necessary, the specific contents of the terms will be explained, followed by coating with a coating-forming substance. The technical means for preparing the high pressure type boron nitride quasi-fine particles will be described.

Coated High-Pressure Type Boron Nitride Quasi-Fine Particles The coated high-pressure type boron nitride quasi-fine particles are the following high-pressure type boron nitride quasi-fine particles coated. For example, specifically, the coating material is a high-pressure boron nitride fine particle as a core particle in one or more forms of ultrafine particles, islands, continuous substances, uniform film, protrusions, and the like. It refers to coated quasi-fine particles that have been coated.

Raw Material Powder Particles for High-Pressure Boron Nitride Quasi-Fine Particles The high-pressure type boron nitride quasi-fine particles according to the present invention, which are coated high-pressure type boron nitride quasi-fine particles having a surface coated with a coating-forming substance, are produced. For the raw material powder particles of the high-pressure type boron nitride quasi-fine particles, cubic boron nitride quasi-fine particles and / or wurtzite type boron nitride quasi-fine particles are used. The raw material powder for the coated high-pressure type boron nitride quasi-fine particles is not particularly limited as long as the high-pressure type boron nitride quasi-fine particles have an average particle size of more than 10 μm. Specifically, the high-pressure type boron nitride quasi-fine particles can be expressed as a distribution in which the average particle size D _M exceeds 10 μm ([D _M / 5,5D _M ], ≧ 90%) in a volume-based frequency distribution. Boron quasi-fine particles are applied. But,
Preferably, the average particle diameter D _M exceeds 10 μm in a volume-based frequency distribution with a relatively narrow distribution ([D _M / 3,3
D _M ], ≧ 90%) high pressure type boron nitride quasi-fine particles can be selected. More preferably, the particle size of the high-pressure boron nitride quasi-fine particles is controlled by, for example, sieving classification, and the average particle size D _M exceeds 10 μm in a volume-based frequency distribution ([D _M /
2,3D _M / 2], ≧ 90%) high-pressure type boron nitride quasi-fine particle powder can be selected.

Raw Material Powder Particles for Coated High-Pressure Type Boron Nitride Quasi-Fine Sintered Body As the raw material powder particles for the coated high-pressure type boron nitride quasi-fine sintered body, the above-mentioned coated high-pressure type boron nitride particles are applied. By sintering the coated high-pressure type boron nitride powder quasi-fine particles or a mixture containing the coated high-pressure type boron nitride powder quasi-fine particles, the coating forming substance is smashed to obtain the quasi-fine particles of the coated high-pressure type boron nitride powder quasi-fine particles. Except where the fine particles are in direct contact with each other and bonded together, the binder and /
Or there are sintering aids and / or surface modifications. An extremely highly controlled microstructure of a high-pressure type boron nitride quasi-fine particle sinter in a coated high-pressure type boron nitride quasi-fine particle sintered body, which has no unsintered portion and is uniformly, densely and strongly sintered. It is possible to manufacture a high-performance coated high-pressure boron nitride quasi-fine particle sintered body having Since the high-pressure type boron nitride suppresses the phase transition to the graphite type phase, when a substance having a catalytic action is used during the synthesis, it is preferable to remove this substance as much as possible. As the most preferable example, for example, ultra-high purity cubic boron nitride synthesized through a vapor phase by a physical vapor deposition method (PVD method) or a chemical vapor deposition method (CVD method) can be selected. When synthesized into a thin film, crush and use it while paying attention to contamination by impurities. When it is synthesized in the form of granules or powder, it can be used as a mask. As another high-purity example, a high-purity single crystal grown over time can be selected. Alternatively, cubic boron nitride powder particles obtained by actively removing impurities can be selected.

Vapor-phase coating method The vapor-phase coating method is a method in which the raw material of the coating-forming material is at least once in a vapor-phase state composed of one or more of molecular flow, ionic flow, plasma, gas, vapor and aerosol. ,
Alternatively, it refers to a method of coating with a raw material of a coating forming substance in a gas phase.

Core Particles Core particles are particles to be coated. This is also referred to as matrix particles, seed particles or coated particles. The core particles are composed of high-pressure boron nitride quasi-fine particles, specifically cubic boron nitride quasi-fine particles and / or wurtzite type boron nitride quasi-fine particles.

Core particle powder The core particle powder is a powder composed of core particles. The particles of the core particle powder refer to particles constituting the core particle powder. The particles of the quasi-fine particle core particle powder to be used in the coating used in the present invention or the particles of the core particle powder mainly composed of quasi-fine particles have an average particle diameter of more than 10 μm in volume-based frequency distribution. Preferably, when the average particle diameter is D _M , D _M is 10 μm
, The particle size distribution is a volume-based frequency distribution ([D _M / 5,
5D _M ], ≧ 90%). In such a powder having a relatively narrow distribution, the dispersion property or agglomeration property of the powder is characterized by the average particle size, and the fine particle high dispersion treatment means group is operated under the conditions suitable for the value of D _M. Can be dispersed. The particle size distribution of the particles of the core particle powder having an average particle size of more than 10 μm is
In the case of a powder having a wide distribution or a distribution having a plurality of peaks separated from each other, a suitable selective separation treatment, for example, classification treatment is preferably performed, and the coating treatment of the present invention is applied to each classified powder. As a result, under the above conditions for each classified powder, the dispersity β in the coating start region of the coating space is 80% or more, 90% or more, 95% or more, 97 depending on the average particle size. % Or 99% or more, the coating is started, and it becomes possible to coat each particle of the core particle powder.

Coating-forming substance The coating-forming substance is a substance that forms a coating on an object to be coated. For example, specifically, ultrafine particles, islands,
It refers to a substance that forms a coating on the particles of the core particle powder in the form of one or more types such as a continuous substance, a uniform film, and protrusions.
Particularly, when the form of the coating forming material is ultrafine particles, the particle diameter of the ultrafine particles is, for example, in the range of 0.005 μm to 0.5 μm. This coating forming substance forms a coating as it is, or the coating forming substance reacts with the high-pressure type boron nitride of the core particles and / or forms a solid solution with the high-pressure type boron nitride quasi-fine particles. And / or one kind of an inorganic compound, an alloy, an intermetallic compound or the like which is a target for reacting and / or alloying and / or solid-solving two or more kinds of coating forming substances to form a coating It becomes a sintering aid that accelerates the sintering of the coated high pressure type boron nitride quasi fine particles and / or a simple substance that serves as a binder and / or a surface modifier of the high pressure type boron nitride quasi fine particles. It is selected from simple substances and / or compounds.

As the coating material for directly coating the high pressure type boron nitride quasi fine particles, a coating material which does not promote the phase transition of the high pressure type boron nitride to the graphite type phase is selected. A coating forming substance can be selected as a surface modifier for controlling the grain boundaries of the high-pressure boron nitride quasi-fine particles. If necessary, for example, to enhance the chemical bond between the high-pressure type boron nitride quasi-fine particles and the sintering aid and / or the binder, or to separate the individual high-pressure type boron nitride quasi-fine particles from any substance, This allows
It is possible to suppress the phase transition of the high pressure type boron nitride to the graphite type phase or to suppress the reaction between the high pressure type boron nitride and an arbitrary substance. Thereby, the sintering aid and / or
Alternatively, the range of selection of the coating forming material as the binder is greatly expanded and suitable.

These coating-forming substances are listed in Periodic Table 1a,
2a, 3a, 4a, 5a, 6a, 7a, 1b, 2b, 3
b, 4b, 5b, 6b, 7b, group 8 metals, semiconductors, semimetals, rare earth metals, nonmetals, and oxides, nitrides thereof,
Carbide, oxynitride, oxycarbide, carbonitride, oxycarbonitride,
One or more of boride and silicide, such as Al,
B, Si, Fe, Ni, Co, Ti, Nb, V, Zr,
Hf, Ta, W, Re, Cr, Cu, Mo, Y, La,
TiAl, Ti ₃ Al, TiAl ₃ , TiNi, NiA
l, Ni ₃ Al, SiC, TiC, ZrC, B ₄ C, W
C, W ₂ C, HfC, VC, TaC, Ta ₂ C, NbC,
Mo ₂ C, Cr ₃ C ₂ , Si ₃ N ₄ , TiN, ZrN, Si ₂
N ₂ O, AlN, HfN, V _x N (x = 1 to 3), Nb
N, TaN, Ta ₂ N, TiB, TiB ₂ , ZrB ₂ , V
B, V ₃ B ₂ , VB ₂ , NbB, NbB ₂ , TaB, TaB
₂ , MoB, MoB ₂ , MoB ₄ , Mo ₂ B, WB, W
₂ B, W ₂ B ₅ , LaB ₆ , B ₁₃ P ₂ , MoSi ₂ , BP, A
l ₂ O ₃ , ZrO ₂ , MgAl ₂ O ₄ (spinel), Al ₂ S
It can be a substance containing one or more of iO ₅ (mullite). The coating amount of the coating forming substance that coats the surface of the coated high-pressure type boron nitride quasi-fine particles is not particularly limited, but is preferably such that the coated high-pressure type boron nitride quasi-fine particle sintered body can be densified. Any amount is selected.

Uniform coating In the case of a uniform film-forming material, it means that the thickness of the coating film is uniform every single particle. When the coating forming substance is in the form of ultrafine particles, islands or protrusions, it means that the coating forming substance in the form of ultrafine particles, islands or protrusions is coated in a uniform distribution. Inevitable inhomogeneities in the process of producing coating-forming substances are included in the category of uniformity.

Definition of charging into the coating space The charging into the coating space means, for example, introducing the core particle powder into the coating space by falling such as free fall. In the case of charging with carrier gas, the core particle powder is introduced by carrying it in the flow direction of the particle / gas mixture of the core particle powder, or by carrying it on the gas in the flow direction, or by changing the riding direction of the gas. It means being introduced. Alternatively, it also means that the gas is introduced under the action of the carrier gas. For example, it also refers to introduction by a wave phenomenon of carrier gas, specifically, a non-linear wave. Alternatively, it also means introducing into the coating space by a sound wave in a gas, an ultrasonic wave, a magnetic field, an electron beam, or the like. It also means introduction by an external field such as an electric field, a magnetic field, or an electron beam. Specifically, it also means that the powder particles are charged or magnetized by an electric field, a magnetic field, an electron beam or the like and introduced into the coating space by an attractive force or a repulsive force. It also includes the introduction and introduction of gas by back pressure or pressure reduction.

Coating Space In the coating space, the particles of the core-particle powder contact and / or the precursor of the coating-forming substance produced from the raw material of the coating-forming substance through the gas phase and / or the precursor of the coating-forming substance in the gas phase Or, it means the space where it collides. Alternatively, it refers to a space region in which the surface of the particles of the core particle powder is coated with the coating forming substance.

Coating Chamber The coating chamber is a chamber that has at least a part of the coating space. More specifically, the coating chamber is a partition including a coating space,
Or it is a room that is partitioned (generally closed, semi-closed),
This is a room that contains a part or more of the coated space.

In the air, the air refers to the inside of a vacuum or a gas phase space. here,
In the present invention, the gas phase state means a state such as molecular flow, ion flow, plasma, gas and vapor. The vacuum is technically a reduced pressure state. Strictly speaking, gas, molecule, atom, ion, etc. are contained under any reduced pressure.

Coating Forming Substance Precursor A coating forming substance precursor is a precursor of a coating forming substance. More specifically, the raw material of the coating-forming substance in the vapor phase is formed as it is, or is formed and / or synthesized from the raw material of the coating-forming substance through the vapor phase to form a coating on the core particles which are particles to be coated. It refers to the substance until just before. The coating substance precursor is not limited in its state as long as it is formed and / or synthesized from the raw material of the coating substance via the gas phase. When the raw material of the coating forming substance is in the gas phase, the raw material can also be a coating forming substance precursor. The coating forming material precursor itself may be in the gas phase. When the coating-forming substance precursor is a reactive substance, it may be before the reaction, during the reaction, or after the reaction. Specific examples of the coating material precursor include ions,
Atoms, molecules, clusters, atomic clusters, molecular clusters, cluster ions, ultrafine particles, gases, vapors, aerosols and the like can be mentioned.

Raw Material of Coating Forming Material The raw material of the coating forming material means a raw material which becomes a material which forms a coating through a gas phase. Specific examples of the form of the raw material of the coating forming substance include lumpy solids, powder particles, gas and liquid.

Dispersity β Dispersity β is proposed by Masuda and Goto as an index for evaluating the dispersion performance of a powder disperser (Chemical Engineering, 22nd Autumn Meeting, Abstracts of Research Presentations, P349 (1989)). reference)
As described above, it is defined as the ratio of the weight of particles in the apparent primary particle state to the weight of all particles. Here, the apparent primary particle state particles, the overlap of the frequency distribution f _m1 of mass of the powder particles and the frequency distribution f _m2 of mass of the powder particles of any dispersed state is completely dispersed It indicates the ratio of the part that is being expressed and is represented by β in the following equation.

[0037]

[Equation 1] In the above equation, the unit of particle diameter (μm) is not specified. In the above formula, the dispersity is evaluated based on the particle size distribution expressed on a mass basis, but the dispersity should be evaluated based on the particle size distribution expressed on a volume basis. However, when the powder particle densities are the same, the particle size distribution expressed by mass and the particle size distribution expressed by volume are the same. Therefore, the particle size distribution based on mass, which is practically easy to measure, is measured,
It is used as a volume-based particle size distribution. Therefore, the original dispersion degree β is expressed by the following equation and the area of the shaded portion in FIG.

[0038]

[Equation 2] In the above, the unit of particle size (μm) is not specified. And the distribution and average particle size of the core particle powder are
Unless otherwise specified, the volume standard is basically used.

Volume-Based Frequency Distribution The volume-based frequency distribution refers to the distribution of particle diameters expressed by the volume ratio contained in a certain particle diameter.

[0040] ([D _1, D _2], ≧ 90%) Definition of ([D _1, D _2], ≧ 90%) and the distribution, D _1, the particle diameter D _2, where D ₁ <D ₂ , A distribution in which 90% or more by volume of particles of D ₁ or more and D ₂ or less is contained, and a powder composed of particles having a shaded portion ratio of 90% or more as shown in FIG. Represent

Volume-based frequency distribution ([D _M / 5,5D _M ],
≧ 90%) The particle size distribution is a volume-based frequency distribution ([D _M / 5,5
D _M], and is ≧ 90%) distribution, when the average particle diameter on a volume basis of D _M, 1/5 times the particle size or less on the D _M, volume 5 times under particle size or less particles of D _M Represents a distribution containing 90% or more. For example, when the average particle size D _M is 5 μm and the volume-based frequency distribution is ([D _M / 5,5D _M ], ≧ 90%), the volume-based average particle size is 5 μm and particles of 1 μm or more and 25 μm or less. The distribution is such that 90% or more by volume of particles are included. Here, the volume-based average particle diameter D _M is

[Equation 3] Alternatively, technically, a certain particle size interval is set to D _i ± ΔD _i / 2 (Δ
D _i is the volume of the particles that are within the width of the segment) and V _i, is expressed by _{D M = Σ (v i D} i) / Σv i.

Coating start region The region where coating is started for the first time after the final treatment of the group of means for high-dispersion fine particles is called the coating start region. Therefore, even before the final treatment of the fine particle high-dispersion treatment means group, the area where the coating is first started is not the coating start area here.

Dispersion degree β in coating start region In the present invention, (1) the volume-based frequency distribution has an average particle size of 1
A core particle powder having a particle size of more than 0 μm and not more than 20 μm is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to form a particle / gas mixture of the highly dispersed core particle powder, and the dispersion of the particles of the core particle powder. The degree β is set to 80% or more, or (2) the core particle powder having an average particle size of more than 20 μm and 50 μm or less in the volume standard frequency distribution is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group. As a particle / gas mixture of highly dispersed core particle powder, the degree of dispersion β of the core particle powder is 90%.
Or (3) core particle powder having an average particle size of more than 50 μm and 300 μm or less in the volume standard frequency distribution is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to obtain highly dispersed core particles. A powder particle / gas mixture is used, and the dispersity β of the particles of the core particle powder is 95% or more, or (4) the core particle powder having an average particle diameter of more than 300 μm and 800 μm or less in the volume standard frequency distribution. Whether the body is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to form a particle / gas mixture of highly dispersed core particle powder, and the degree of dispersion β of the particles of the core particle powder is 97% or more. Or (5) a core particle powder having a volume-based frequency distribution and an average particle diameter of more than 800 μm,
By the final treatment of the quasi-fine particle high dispersion treatment means group, it is dispersed in the air to form a particle / gas mixture of highly dispersed core particle powder, and the area of the core particle powder with a dispersity β of 99% or more is covered. A coating chamber in which the coating start region of the space is located is provided.

As far as the dispersity is in the coating start region of the above-mentioned coating space, the particles of the core particle powder are quasi-fine particles having an average particle diameter of more than 10 μm in the volume-based frequency distribution, or mainly particles of the quasi-fine particles. Core particles consisting of fine particles
The coating material precursor can evenly contact and / or collide with the surface of all particles of the core particle powder that can be dispersed in the air into a single particle state and pass through the coating start region of the coating space. , A uniform amount of coating-forming material can be applied to a single particle. In the quasi-fine particles having an average particle size of more than 10 μm, the dispersity β changes continuously with the average particle size of the core particle powder, but since it is difficult to express, it is expressed stepwise for convenience.

Preferably, (1) a core particle powder having a volume-based frequency distribution and an average particle diameter of more than 10 μm and 20 μm or less is dispersed in the air by the final treatment of the quasi-fine particle high-dispersion processing means group to obtain a highly dispersed core. A particle / gas mixture of particle powder, and the degree of particle dispersion β of the core particle powder is 90% or more, or (2) core particle powder having an average particle size of more than 20 μm and 50 μm in a volume-based frequency distribution. Whether the body is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to form a particle / gas mixture of highly dispersed core particle powder, and the dispersity β of the particles of the core particle powder is 95% or more. Or (3) core particles having an average particle size of more than 50 μm and not more than 300 μm in a volume-based frequency distribution are dispersed in the air by the final treatment of the quasi-fine particle high-dispersion treatment means group to form particles of highly dispersed core particles powder・ Dispersion degree β of core particle powder as a base mixture 97% or more, or (4) core particle powder having an average particle size of more than 300 μm in the volume standard frequency distribution is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to obtain a highly dispersed core particle powder. As a mixture of body particles and substrate, the degree of dispersion β of the core particles is 99%.
A coating chamber in which the coating start region of the coating space is located in the above space region is provided. In the coating chamber in which the coating start region of the coating space is positioned as described above, the particles of the core particle powder have an average particle diameter of 10 μm in the volume standard frequency distribution.
Particles of quasi-fine particle core particle powder exceeding m or particles of core particle powder mainly composed of quasi-fine particles can be more uniformly coated with a coating forming substance in a single particle unit, and coated for each core particle. A more uniform amount of coating is possible.

Volume-based frequency distribution with an average particle size of 10 μm
Particles of quasi-fine particle core particles having a particle size of more than 50% or particles of core particle powder mainly composed of quasi-fine particles have an aggregating action in the air, and the particles are in contact with each other and / or collide with each other to obtain highly dispersed core particle powder. Non-uniform distribution of particles in the core particle powder in the body particle / gas mixture. However, if the coating is started in a dispersed state such as the degree of dispersion according to the particle size of the core particle powder, the particles of the quasi-fine particle core particle powder or the particles of the core particle powder mainly composed of quasi-fine particles The single particle unit can coat the coating forming material uniformly, and each particle can coat the coating forming material in a more uniform amount.

Semi-fine particle high dispersion treatment means group In the present invention, the semi-fine particle high dispersion treatment means group includes (A) at least one dispersion means and (B) a final treatment means (a) Dispersing means for dispersing particles of the core particle powder in the air, or (b) a low dispersion core particle powder in a mixture of particles of the core particle powder in which the particles of the core particle powder are dispersed in the air and gas. A particle / gas mixture of highly dispersed core particle powder that separates the body part and selects the particle / gas mixture of highly dispersed core particle powder in which the particles of the core particle powder mainly exist in the air in a single particle state. The final dispersion means and / or the final dispersion of the dispersion means in the quasi-fine particle high dispersion treatment means group for the powder portion of the low dispersion core particles separated by the selection means and the particle / gas mixture selection means of the high dispersion core particle powder. High-dispersion core with feedback means for conveying to processing means before the means And it has a particle-gas mixture selection means child powder.

Preferably, (1) core particle powder having a volume-based frequency distribution and an average particle size of more than 10 μm and 20 μm or less is dispersed in the air by the final treatment of the quasi-fine particle high-dispersion treatment means group and highly dispersed. The particle / gas mixture of the core particle powder is used, and the degree of particle dispersion β of the core particle powder is 80% or more, or
Or (2) a core particle powder having an average particle diameter of more than 20 μm and not more than 50 μm in a volume-based frequency distribution is dispersed in the air by the final treatment of the quasi-fine particle high-dispersion treatment means group to form particles of the highly dispersed core particle powder. As a gas mixture, the degree of dispersion β of the particles of the core particle powder is 90% or more, or (3) the core particle powder having an average particle size of more than 50 μm and 300 μm or less in the volume standard frequency distribution is quasi-fine particle The final treatment of the dispersion treatment means group disperses in air to form a particle / gas mixture of highly dispersed core particle powder, and the degree of dispersion β of the particles of the core particle powder is 95% or more, or (4) Volume-based frequency distribution with an average particle size of 3
A core particle powder of more than 00 μm and 800 μm or less is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to form a particle / gas mixture of the highly dispersed core particle powder, and the dispersion of the particles of the core particle powder. The degree β should be 97% or more, or (5)
A core particle powder having a volume-based frequency distribution and an average particle diameter of more than 800 μm is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to form a particle / gas mixture of the highly dispersed core particle powder. It has a dispersibility in which the dispersity β of the particles of the particle powder is 99% or more. Corresponding to various dispersities in the coating start region, by providing a group of quasi-fine particle high dispersion treatment means having a dispersion performance equivalent to or higher than those of the dispersion start regions, a high-quality coating corresponding to each dispersity is performed in the coating start region. be able to.

Final Treatment Means When the final treatment means of the semi-fine particle high dispersion treatment means group is a dispersion means, this dispersion treatment means is referred to as the final treatment means of the fine particle high dispersion treatment means group. Also, the final processing means of the quasi-fine particle high dispersion processing means group is added to the final dispersion means of the quasi-fine particle high dispersion processing means in a low dispersion state at the time of the particle / gas mixture selective processing step of the highly dispersed core particle powder. The particles / gas mixture selection means of the highly dispersed core particle powder provided with the feedback means for conveying the selected and separated portion, or the treatment means before the final dispersion means, the particles of the highly dispersed core particle powder.・
In the case of the particle / gas mixture selecting means of the highly dispersed core particle powder, which is provided with the feedback means for conveying the selectively separated portion due to the low dispersion state in the gas mixture selection treatment step, this highly dispersed core particle powder The means for selecting the body particle / base mixture is referred to as the final processing means of the quasi-fine particle high dispersion processing means group. In addition, it is provided before the particle / gas mixture selecting means of the highly dispersed core particle powder having the feedback means which is the final treatment means of the quasi-fine particle highly dispersed treatment means group (for example, the highly dispersed core particle powder having the feedback means). Between the particle / gas mixture selecting means of the body and the final dispersing means, or before the final dispersing means) The highly dispersed core particle powder particle / gas mixture selecting means is a group of means for high-dispersion treatment of fine particles regardless of presence / absence of feedback means. Is a component of.

Dispersing Means The means used to disperse the quasi-fine particles is called a dispersing means. This dispersing means can be used as a dispersing means if it has a dispersing effect even if only a little or slightly. For example, a rotary feeder for air transportation and an injection feeder (edited by Japan Society of Powder Engineering: “Powder Engineering Handbook”, Nikkan Kogyo Shimbun (1986) P568, P571), which are generally used as a supply means, have a dispersing effect, and thus are dispersed. When used as a target means, it is a dispersion means. When the dispersion maintaining / promoting means described later is also used for the purpose of dispersion (to increase β), it becomes a dispersion means.
And even if this dispersion means is a single device or device,
It may be a combined device or device, and these are collectively referred to as a quasi-fine particle high dispersion treatment means group. This quasi-fine particle high dispersion treatment means group disperses particles of the core particle powder by an air flow that is placed in an acceleration and / or velocity gradient, and the particles of the core particle powder to stationary obstacles and / or obstacles composed of a rotating body. Dispersion by collision, fluidized bed of particles of core particle powder and / or pulsating flow and / or
Alternatively, it means one provided with a mechanism for one or more kinds of selected dispersion such as dispersion by mechanical disintegration consisting of a rotating drum and / or vibration and / or scraping.

Specifically, the quasi-fine particle high dispersion treatment means group includes an ejector type dispersion machine, a Venturi type dispersion machine, a thin tube,
Stirrer, Disperser that uses obstacles in the air flow, Disperser that uses jet spraying, Spiral tube, Disperser that uses rotating blades, Disperser that uses rotating pins (cage mill), fluidized bed type Disperser, Disperser using pulsating flow, Disperser using rotating drum, Disperser using vibration, Vibration sieve, Disperser using scraping by scraper, SA
EI, Gonell type disperser, Nakajo type disperser, Roller type disperser,
Orifice type disperser, BM type disperser, Timbrell type disperser, Wright type disperser, etc. are provided with a dispersing means consisting of one or more types selected. Nikkan Kogyo Shimbun (1986) P430).

Further, a disperser utilizing a stirring blade described in JP-A-56-1336, a disperser utilizing a high-speed air stream and a dispersion nozzle described in JP-A-58-163454, and JP-A-59-199027. Disperser utilizing the dispersing action by the rotating blade and the dispersing action by plasma ions described in No.
A disperser utilizing the dispersing action of plasma ions described in JP-A-59-207319, and JP-A-59-2166.
No. 16, a disperser utilizing the dispersing action of an ejector and plasma ions, No. 59-225728, a disperser utilizing the dispersing action of an ejector and an ion flow, and No. 59-183845. Disperser utilizing the dispersing action of plasma ions of JP-A-63-1664
No. 21, a disperser utilizing a dispersing action by a dispersion blade and a pressure gas, a disperser using a line-shaped or ring-shaped slit type jet outlet described in JP-A-62-176527,
A disperser using a mesh blade described in JP-A No. 63-221829, a disperser using a dispersing action by a high-speed air stream from an injection nozzle described in JP-A No. 63-1629, No. Shokai 63-9218. And the ejector type disperser described in Japanese Utility Model Publication No. 62-156854, and the disperser using the micropores and orifices described in Japanese Utility Model Publication No. 63-6034. Those described in can also be used. Dispersing means suitable for a group of quasi-fine particle high-dispersion processing means include Japanese Patent Application No. 63-311358 and Japanese Patent Application No. 1-710.
71 and Japanese Patent Application No. 2-218537.

Highly-dispersed core particle powder particle / gas mixture selection means Highly dispersed core particle powder particle / gas mixture selection means means a low-dispersion core particle powder from a core-particle powder particle / gas mixture. A means for separating a particle / gas mixture and selecting a particle / gas mixture of highly dispersed core particle powder mainly containing particles in a single particle state. Aggregated particles, which are aggregates of primary particles, have an apparent particle diameter larger than the particle diameter of primary particles, and therefore can be separated by, for example, a dry classification means. Examples of means for selecting a particle / gas mixture of highly dispersed core particle powder include classification means using gravity, classification means using inertial force, classification means using centrifugal force, classification means using static electricity, fluidized bed. Examples of the dry classification means include one or more selected from the classification means utilizing the. Examples of means for selecting a particle / gas mixture of this highly dispersed core particle powder include a gravity classifier, inertia classifier, centrifugal classifier, cyclone, air separator, micron separator, microplex, multiplex, zigzag classifier, accu classifier. Cut, conical separator, turbo classifier, super separator, dispersion separator, elbow jet, fluidized bed classifier, virtual impactor, O-Sepa, sieve, vibrating screen, shifter (Powder Engineering Handbook: “Powder Engineering Handbook”) Nikkan Kogyo Shimbun, P514 (1
986)) and the like.

Particle / gas mixture of core particle powder A particle / gas mixture of core particle powder means (a) a homogeneous flow in which particles of the core particle powder are uniformly suspended in air (a uniform floating flow). ), (B) Inhomogeneous flow (non-homogeneous floating flow) in which particles of the core particle powder show a non-uniform distribution in a certain area in the air, (c) accompanied by a sliding layer of particles of the core particle powder Flow (sliding flow), or
(d) A flow with a stationary layer of particles of core particle powder.

Particles / gas mixture of low-dispersion core particle powder The particles / gas mixture of low-dispersion core particle powder means particles of the core particle powder mainly in the particles / gas mixture of the core particle powder. A particle-gas mixture of core particle powder that exists in the air in a state other than a single particle state.

Particle / gas mixture of highly dispersed core particle powder A particle / gas mixture of highly dispersed core particle powder is a core particle powder in which the particles of the core particle powder mainly exist in the air in a single particle state. A particle / gas mixture of the body. Highly dispersed core particles Powder particles
The gas mixture, even with a very high dispersion, actually contains agglomerated particles. The particle / gas mixture of low-dispersion core particle powder is
Actually, it contains unaggregated single particles, and is selectively separated into a particle / gas mixture of low-dispersion core particle powder and a particle / gas mixture of high-dispersion core particle powder. The particle / gas mixture of the low-dispersion core particle powder becomes a particle / gas mixture of the high-dispersion core particle powder by selectively separating and / or re-dispersing the agglomerated particles.

Collecting Means The means for taking out the coated quasi-fine particles coated in the coating space is called collecting means. The part of the recovery means that performs the recovery process is called the recovery part. The coated quasi-fine particles coated by passing through the coating start region of the coating space are directly taken out from the air and collected, or taken out from the air and temporarily stored and then collected, or are collected together with the gas. . As the collecting unit of the collecting unit, a collecting unit of a collecting unit using a partition wall (obstacle), a collecting unit of a collecting unit using gravity, a collecting unit of a collecting unit using inertial force, a collecting unit using centrifugal force Collection part, collection part of collection means using attractive force due to electrification, collection part of collection means using thermophoretic force, collection part of collection means using Brownian diffusion, suction force by back pressure or decompression of gas, etc. It is possible to use the recovery unit of the recovery means used. As a preferred example of the recovery unit of this recovery means, gravity dust collector, inertial dust collector, centrifugal dust collector, filtration dust collector, electric dust collector, washing dust collector, particle packed bed, cyclone, bag filter,
Examples include ceramics filters and scrubbers.

Binder As the binder used in the production of the coated high-pressure boron nitride quasi-fine particle sintered body of the present invention, the pressure is less than 2000 MPa, and 1
By sintering at a temperature not exceeding 850 ° C, a density of 8
A binder that is densely sintered to 5% or more is selected. Preferably, furthermore, a binder is selected which does not promote the phase transition of the high pressure boron nitride to the graphite type phase. Alternatively, a dense binder having a density of 85% or more of a reaction product formed by reacting with boron nitride is selected by sintering at a pressure of less than 2000 MPa and a temperature not exceeding 1850 ° C. It More preferably, the pressure is 2000M
A material that is sintered at a temperature of less than Pa and does not exceed 1850 ° C. to be a dense binder having a density of 90% or more and / or a high hardness of Vickers hardness of 600 or more is selected.
By sintering at a pressure of less than 2000 MPa and a temperature of not exceeding 1850 ° C., the raw material powder to be a dense binder having a density of 85% or more can be obtained by the periodic table 1a, 2a, 3a, 4
a, 5a, 6a, 7a, 1b, 2b, 3b, 4b, 5
b, 6b, 7b, group 8 metal, semiconductor, semimetal, rare earth metal, and / or powder or particles containing at least one kind of compound containing one or more kinds thereof. . More specifically, the powder or particles are
B, Ti, Zr, Hf, Ta, Nb, V, SiC, Ti
C, ZrC, B ₄ C, WC, HfC, TaC, NbC,
Si ₃ N ₄ , TiN, ZrN, AlN, HfN, TaN,
TiB, TiB ₂ , ZrB ₂ , HfB, HfB ₂ , La
_{B 6, MoSi 2, BP,} Al 2 O 3, Al 2 SiO 5 ( mullite), ZrO ₂ (zirconia was added Y ₂ O _8, MgO or CaO Stabilizer: PSZ or tetragonal zirconia polycrystals: TZP) , MgAl ₂ O ₄ (spinel), at least one kind of powder or particles.
As a preferable example, for example, alumina is a fine raw material having high purity and easy sinterability. Normal sintering of 140
It is suitable because it is densified at a temperature of about 0 ° C. Furthermore, magnesia (Mg
O) and / or titania (TiO _x , x = 1 to 2) up to 10% by volume, as long as it is a fine and highly pure alumina powder, other than the alumina described in JP-A-63-151616. High-purity alumina, such as Bayer method, organoaluminum hydrolysis method, aluminum alum pyrolysis method, ethylene chlorohydrin method, underwater spark discharge method, etc.
%, High-purity, easily-sinterable alumina may be used.

Other than the above-mentioned alumina, zirconium oxide, preferably yttria-added partially stabilized zirconia (2-4 mol% Y ₂ O), which is easily sinterable and is produced by a coprecipitation method.
_3- ZrO ₂ ) powder or alumina-zirconia powder (FC report, 1 [5] (1983) 13-17)
Or titania powder that is titanium oxide (TiO ₂ : first
5th High-Press Conference Discussion Lecture Collection, (1973) P174) is selected. Further, as a titanium nitride, titanium nitride (TiN: Yamada Soga, Ceramic Industry Association, 89, (1981) 6
21 to 625) can be selected. Next, a group of means for high-dispersion quasi-fine particles used for preparing coated high-pressure boron nitride quasi-fine particles used in the present invention will be described with reference to the accompanying drawings.

FIG. 2 (a) shows an example of the basic structure of the quasi-particulate high-dispersion processing means group when preparing coated high-pressure boron nitride quasi-fine particles. It is a block diagram. It is composed of the final dispersion means A for dispersing the particles of the core particle powder and the constituent element d of the dispersion processing means group before the final dispersion means. [epsilon] is a particle / gas mixture of highly dispersed core particle powder, which exists in the air mainly in a single particle state among particles of the core particle powder. As the component d, dispersing means, supplying means, particles of highly dispersed core particle powder,
Any processing means such as a gas mixture selecting means can be used alone or in combination. The component d does not necessarily have to be provided. After the final treatment by the treatment means A, the group of quasi-fine particles high dispersion treatment means preferably has (1) the degree of dispersion β with respect to the core particle powder having an average particle diameter of more than 10 μm and 20 μm or less in the volume standard frequency distribution. Is 80% or more, or (2) core particles having a volume-based frequency distribution with an average particle size of more than 20 μm and 50 μm or less, a dispersity β of 90% or more, or (3) an average particle with a volume-based frequency distribution. Dispersity β is 95% or more with respect to core particle powder having a diameter of more than 50 μm and 300 μm or less, or (4) dispersion with respect to core particle powder having an average particle diameter of more than 300 μm and 800 μm or less in volume standard frequency distribution Degree β is 97
% Or more, or (5) the volume-based frequency distribution has an average particle size of 8
Dispersion degree β is 99% for core particle powder exceeding 00 μm
The configuration is capable of realizing the above.

FIG. 2 (b) is a block diagram showing a second example of the basic constitution of the quasi-fine particle high dispersion treatment means group when preparing the coated high-pressure type boron nitride quasi-fine particles. The final dispersion means A for dispersing the particles of the core particle powder, and the particles of the core particle powder to the final dispersion means A are particles of the highly dispersed core particle powder in the air mainly in the form of a single particle. Other than the gas mixture, the particles / gas mixture selecting means B of the final high-dispersion core particle powder having the feedback means C for feeding back the particles / gas mixture η of the low-dispersion core particle powder, the dispersion before the final dispersion means It is composed of a constituent element d of the processing means group and a constituent element e of the quasi-fine particle high dispersion processing means group between the final dispersion means and the final selection means. ε is the particle of the core particle powder,
It is a particle-gas mixture of highly dispersed core particle powder that exists mainly in the air in the form of single particles. As the constituent element d, any processing means such as a dispersing means, a supplying means, a selecting means can be used alone or in combination. As the component e, a processing means other than the dispersion means, for example, an arbitrary processing means such as a supply means and a selection means can be used alone or in combination. Component d
And e do not necessarily need to be provided. The quasi-fine-particles high-dispersion treatment means group is preferably configured so that the degree of dispersion can be realized with respect to the core particle powder having the average particle diameter after the treatment by the selection means B which is the final treatment means.

FIG. 2 (c) is a block diagram showing another third example of the basic constitution of the quasi-fine particle high dispersion treatment means group when preparing the coated high-pressure type boron nitride quasi-fine particles. Highly dispersed core particles in which particles of the core particle powder are mainly present in the air in a single particle state to the final dispersion means A for dispersing the particles of the core particle powder and the processing means prior to the final dispersion means A. Powder particles / gas mixture, other than low-dispersion core particle powder particles / gas mixture η with a feedback means C for feeding back final high-dispersion core particles powder particle / gas mixture selection means B, final It is composed of the constituent element d of the quasi fine particle high dispersion processing means group before the dispersing means and the constituent element e of the quasi fine particle high dispersion processing means group between the final dispersing means and the final selecting means. [epsilon] is a particle / gas mixture of highly dispersed core particle powder, which exists in the air mainly in a single particle state among particles of the core particle powder. As the constituent element d, any processing means such as a dispersing means, a supplying means, a selecting means can be used alone or in combination. As the component e, a processing means other than the distribution means,
For example, any processing means such as supply means and selection means can be used alone or in combination. The components d and e do not necessarily have to be provided. The quasi-fine particle high-dispersion treatment means group is preferably after the treatment by the selection means B, which is the final treatment means,
The dispersity can be realized with respect to the core particle powder having the average particle diameter.

Because of the above-mentioned structure, the powder supply sources such as the supply tank and the core particle generating means may be included in the structure of the semi-fine particle high dispersion processing means group. For example, in the case of FIG. 2C, it goes without saying that the configuration in which the feedback destination of the feedback means C is the supply tank may be the configuration of the high dispersion processing means group. Needless to say, a crushing step of crushing and / or crushing particles of the core particle powder may be added before the dispersing step of the quasi-fine particle high dispersion treatment means group. It will be described in more detail based on a more detailed block diagram of a specific representative example of the basic configuration of the group of means for highly dispersing fine particles.

Structure 1 FIG. 3 (a) is a block diagram for explaining the structure 1 of the quasi-particulate high-dispersion processing means group for preparing coated high-pressure type boron nitride quasi-fine particles. ). This example is a supply tank 1 for supplying core particle powder to be coated.
00, the final dispersing means A for dispersing the core particle powder to be coated. ε is the particle of the core particle powder,
It is a particle-gas mixture of highly dispersed core particle powder that exists mainly in the air in the form of single particles.

Structure 2 FIG. 3 (b) is a block diagram for explaining the second structure of the quasi-fine particle high dispersion treatment means group when preparing the coated high pressure type boron nitride quasi-fine particles. ). This example is a supply tank 1 for supplying core particle powder to be coated.
00, dispersing means a for dispersing the core particle powder to be coated,
It comprises a final dispersion means A for dispersing the core particle powder to be coated. ε is the particle of the highly dispersed core particle powder that exists mainly in the air in the form of a single particle among the particles of the core particle powder.
It is a gas mixture.

Structure 3 FIG. 3 (c) is a block diagram for explaining the third structure of the quasi-fine particle high dispersion treatment means group when preparing the coated high-pressure type boron nitride quasi-fine particles. ). This example is a supply tank 1 for supplying core particle powder to be coated.
00, dispersing means a for dispersing the core particle powder to be coated,
Low-dispersion core particle powder other than particles / gas mixture of highly dispersed core particle powder mainly existing in the air in a single particle state from particles / gas mixture of core particle powder dispersed by dispersing means a Feedback means C for feeding back the particle / gas mixture η of the body to the dispersing means a, mainly particles / gas of the highly dispersed core particle powder for introducing the particle / gas mixture of the highly dispersed core particle powder into the final dispersing means A It comprises a mixture selecting means b and a final dispersing means A for dispersing the core particle powder to be coated. [epsilon] is a particle / gas mixture of highly dispersed core particle powder, which exists in the air mainly in a single particle state among particles of the core particle powder.

Structure 4 FIG. 3 (d) is a block diagram for explaining a fourth structure of the quasi-particulate high dispersion treatment means group when preparing the coated high pressure type boron nitride quasi-fine particles, and FIG. ). This example is a supply tank 1 for supplying core particle powder to be coated.
00, the final dispersion means A for dispersing the core particle powder to be coated, and the particle / gas mixture of the core particle powder dispersed by the final dispersion means A, which is mainly present in the air in a single particle state. The particle / gas mixture of the dispersed core particle powder, the feedback means C for feeding back the particle / gas mixture η of the low-dispersed core particle powder to the dispersion means A, and the particle / gas mixture of the highly dispersed core particle powder are discharged. The final high-dispersion core particle powder is composed of a particle / gas mixture selecting means B. ε
Is a particle / gas mixture of the highly dispersed core particle powder, which is mainly present in the air in the form of a single particle among the particles of the core particle powder.

Structure 5 FIG. 3 (e) is a block diagram for explaining the fifth structure of the quasi-particulate high dispersion treatment means group when preparing the coated high pressure type boron nitride quasi-fine particles. ). This example is a supply tank 1 for supplying core particle powder to be coated.
00, dispersing means a for dispersing the core particle powder to be coated,
A high-dispersion core which exists mainly in the air in the form of a single particle from the final dispersion means A for dispersing the core particle powder to be coated and the particle / gas mixture of the core particle powder dispersed by the final dispersion means A. Particles of particle powder / gas mixture, other than low-dispersion core particle powder / feedback means C for feeding back gas mixture η to dispersing means A, particles of high-dispersion core particle powder
Particles of the final highly dispersed core particle powder that emits a gas mixture
It is composed of a gas mixture selecting means B. [epsilon] is a particle / gas mixture of highly dispersed core particle powder, which exists in the air mainly in a single particle state among particles of the core particle powder.

Structure 6 FIG. 3 (f) is a block diagram for explaining the sixth structure of the quasi-particulate high dispersion treatment means group when preparing the coated high-pressure type boron nitride quasi-fine particles. ). This example is a supply tank 1 for supplying core particle powder to be coated.
00, particles / gas mixture of low-dispersion core particle powder are mainly removed from particles / gas mixture of core particle powder, and particles / gas mixture of high-dispersion core particle powder are mainly introduced into dispersing means A. High-dispersion core particle powder particle / gas mixture selecting means b,
It exists mainly in the air in the form of a single particle from the final dispersion means A for dispersing the particles of the core particle powder selectively separated and the particle / gas mixture of the core particle powder dispersed by the final dispersion means A. Feedback means C for feeding back particles / gas mixture η of low-dispersion core particle powder other than particles / gas mixture of high-dispersion core particle powder, releasing particle / gas mixture of high-dispersion core particle powder The final high-dispersion core particle powder particle / gas mixture selecting means B is used. [epsilon] is a particle / gas mixture of highly dispersed core particle powder, which exists in the air mainly in a single particle state among particles of the core particle powder.

Structure 7 FIG. 3 (g) is a block diagram for explaining the seventh structure of the quasi-particulate high dispersion treatment means group when preparing the coated high pressure type boron nitride quasi-fine particles. ). This example is a supply tank 1 for supplying core particle powder to be coated.
00, dispersing means a for dispersing the core particle powder to be coated,
A high-dispersion core mainly present in the air in a single particle state from the final dispersion means A for dispersing the core particle powder to be coated and the particle / gas mixture of the core particle powder dispersed by the final dispersion means A. Particles of particle powder / gas mixture, other than low-dispersion core particle powder / feedback means C for feeding back gas mixture η to dispersing means a, particles of high-dispersion core particle powder
Particles of the final highly dispersed core particle powder that emits a gas mixture
It is composed of a gas mixture selecting means B. [epsilon] is a particle / gas mixture of highly dispersed core particle powder, which exists in the air mainly in a single particle state among particles of the core particle powder.

In order to maintain the high-dispersion state of the quasi-fine particles thus achieved, the air dispersion maintaining means may be added to the quasi-fine particle high-dispersion processing means group. The term "in-air dispersion maintaining means" as used herein means means for preventing re-aggregation of particles of the core particle powder dispersed and carried in air to maintain the degree of dispersion β. Further, in order to promote the highly dispersed state of the core particles thus achieved, an air dispersion promoting means can be added between the fine particle high dispersion treatment means group and the coating chamber. The air dispersion promoting means here promotes redispersion of mainly reaggregated particles among particles of the core particle powder dispersed and carried in the air, and slows down the deterioration of the dispersed state, or once decreases It means a means for promoting re-dispersion so as to recover the dispersed state to the original highly dispersed state.

Suitable examples of the air dispersion state maintaining means or the air dispersion promoting means include a pipe vibrating device, a pipe heating device, a plasma generating device, a charging device and the like.
A pipe vibration device is a means for suppressing reaggregation and maintaining a high dispersion state by giving vibration that is not a disperser to particles dispersed in the air due to the vibration of a pipe equipped with an oscillator or reaggregation. It is a means of promoting the dispersion of the formed particles.
The pipe heating device expands the carrier gas by applying heat from the outside of the carrier gas by the heated pipe, accelerates the flow velocity so that it can not be called a disperser, suppresses reaggregation, and disperses the reaggregated particles. It is a means to promote. The plasma generator generates plasma in the air carrying the core particle powder in a dispersed manner, and by collision of the plasma ions with the core particles,
It is a means for suppressing reaggregation and maintaining a high dispersion state, or a means for promoting the dispersion of reaggregated particles. The charging device uses a method such as corona discharge, electron beam, or radiation to generate unipolar ions in the air carrying the core particle powder, and the particles are unipolar by passing through the unipolar ion atmosphere. It is a means for suppressing re-aggregation by repulsive force of static electricity to maintain a high dispersion state or a means for promoting dispersion of re-aggregated particles. The highly dispersed core particle powder of the quasi-fine particles thus formed is sent to the coating chamber for coating the surface of the particles with the coating forming substance. A coating space including a coating start area is provided in the coating chamber.

It is desirable that the quasi-fine particle high dispersion treatment means group and the coating chamber are directly connected, but they may be connected by using a hollow member and / or a pipe which is inevitable for transportation. Also in this case,
It is indispensable to set the dispersion degree β in the coating start region to a value within the above range. When the quasi-fine particle high dispersion treatment means group and the coating chamber are separately placed and connected to each other, the core particle powder may be introduced into the coating chamber in the dispersed state. For that purpose, the air dispersion maintaining means and / or the air dispersion promoting means and / or the core particle powder which is an apparatus for maintaining the dispersed state of the core particle powder during this period. High-dispersion core particle powder particles that separate the low-dispersion core particle powder part from the particle-gas mixture and select the high-dispersion core particle powder particle / gas mixture that mainly contains particles in a single particle state -Gas mixture selection means can also be provided.
Further, in preparing the coated high-pressure type boron nitride quasi-fine particles, the quasi-fine particle high dispersion treatment means group is (1) a coating chamber, or
It is also possible to share a part or more of the space with (2) the coating space or (3) the coating start region. For example, the dispersion space and the coating chamber in the quasi-fine particle high dispersion treatment means group, or the dispersion space and the coating space having the coating start region in the quasi-fine particle high dispersion treatment means group, or the quasi-fine particle high dispersion treatment means group It is also possible to spatially share the dispersed space and the coating start region therein.

Here, the coating start region means (1) the core particle powder having a volume-based frequency distribution and an average particle size of more than 10 μm and 20 μm or less has a particle dispersity β of 80% or more, (2) The core particle powder having a volume-based frequency distribution with an average particle size of more than 20 μm and 50 μm or less has a particle dispersity β of 90% or more, and (3) a volume-based frequency distribution with an average particle size of more than 50 μm and 300 μm or less. In the case of the core particle powder of
Is 95% or more, and (4) volume-based frequency distribution has an average particle size of 30
The degree of dispersion β of the particles is 97% or more in the core particle powder of more than 0 μm and 800 μm or less, and (5) the dispersion of the particles in the core particle powder of which the average particle size exceeds 800 μm in the volume standard frequency distribution. And / or a coating-forming substance precursor in a gas-phase state is brought into contact with the core particle powder in a highly-dispersed state conveyed in a dispersed state having a degree β of 99% or more and / or Alternatively, it refers to a region where collision occurs and coating is started, and the modes shown in the following FIGS. 4A to 4E are considered. That is, the coating start area is the area indicated by 2 in FIGS.

In FIG. 4 (a), the coating start region 2 of the coating space in which coating is started in the dispersed state of the dispersion degree β described above according to the average particle diameter of the core particles is the semi-fine particle high dispersion treatment means group or the semi-fine particle high dispersion. It is provided so as to cover the discharge part 1 of the processing means group. In FIG. 4B, the coating start region 2 of the coating space through which all the particles 4 of the core particle powder discharged from the discharge part 1 of the quasi-fine particle high dispersion treatment means group or the quasi-fine particle high dispersion treatment means group are provided. With the above configuration, all the particles of the core particle powder are started to be coated in the dispersed state of the degree of dispersion β described above. Figure 4 (c)
In the above, the particles entering the collecting section 5 among the particles 4 of the core particle powder discharged from the discharging section 1 of the quasi-fine particle high dispersion processing means group or the quasi-fine particle high dispersion processing means group always pass through the coating space. Area 2 is provided.

In FIG. 4D, a coating start region 2 of the coating space surrounding the recovery section 5 is provided. In FIG. 4 (e), the recovery unit 5 is provided at a position where only the particles of the highly dispersed core particle powder and the particles of the gas mixture can reach. Therefore, the area 6 here is a selecting means utilizing gravity. The coating start region 2 of the coating space through which the particles of the highly dispersed core particle powder / particles of the gas mixture that enter the recovery section must pass is provided as shown by the hatched portion in the figure. By doing so, only the core particles that have begun to be coated in the dispersed state of the above-described dispersity β can be recovered, and the core particles that have not passed through the coating start region and the coated quasi-fine particles that have passed through the coating start region do not mix.

From the above, the apparatus for carrying out the present invention comprises the quasi-fine particle high dispersion treatment means group and the coating chamber, or the quasi-fine particle high dispersion treatment means group, the coating chamber and the recovery means. The components of these devices can be combined in various ways, and the configuration examples of these devices will be described below with reference to the drawings.

Apparatus Configuration 1 FIG. 5 (a) is a block diagram illustrating the configuration of a first apparatus for producing coated high-pressure boron nitride fine particles. This apparatus of the present example is a manufacturing apparatus body 2 of a coating apparatus.
A, a coating chamber 2-B1, a coating space 2-B2, a coating start region 2-B3, a quasi-fine particle high dispersion treatment means group 2-C1, and a recovery means 2-D. The quasi-fine particle high dispersion treatment means group 2-C1 is directly connected to the coating chamber 2-B1.

Apparatus Configuration 2 FIG. 5 (b) is a block diagram illustrating the configuration of a second apparatus for producing the coated high pressure type boron nitride quasi-fine particles. This apparatus of the present example is a manufacturing apparatus body 2 of a coating apparatus.
A, coating chamber 2-B1, coating space 2-B2, coating start region 2-B3, quasi-fine particle high dispersion treatment means group 2-C1, unavoidable hollow member 2-C2, and recovery means 2-D. . The quasi-fine particle high-dispersion processing means group 2-C1 includes a coating chamber 2-
It is connected to B1 via an unavoidable hollow member 2-C2.

Apparatus Configuration 3 FIG. 5 (c) is a block diagram illustrating the configuration of a third apparatus for producing the coated high pressure type boron nitride quasi-fine particles. This apparatus of the present example is a manufacturing apparatus body 2 of a coating apparatus.
A, coating chamber 2-B1, coating space 2-B2, coating start region 2-B3, quasi-fine particle high dispersion treatment means group 2-C1, air dispersion maintaining means 2-C3, and recovery means 2-D. There is. The quasi-fine particle high-dispersion processing means group 2-C1 includes a coating chamber 2-
It is connected to B1 via the air dispersion maintaining means 2-C3.

Device Configuration 4 FIG. 5 (d) is a block diagram illustrating the configuration of a fourth device for producing the coated high-pressure boron nitride quasi-fine particles. This apparatus of the present example is a manufacturing apparatus body 2 of a coating apparatus.
A, a coating chamber 2-B1, a coating space 2-B2, a coating start region 2-B3, a quasi-fine particle high dispersion treatment means group 2-C1, and a recovery means 2-D. The quasi-fine particle high dispersion treatment means group 2-C1 shares a space with the coating chamber 2-B1.

Device Configuration 5 FIG. 5 (e) is a block diagram illustrating the configuration of a fifth device for producing coated high pressure type boron nitride quasi-fine particles. This apparatus of the present example is a manufacturing apparatus body 2 of a coating apparatus.
A, a coating chamber 2-B1, a coating space 2-B2, a coating start region 2-B3, a quasi-fine particle high dispersion treatment means group 2-C1, and a recovery means 2-D. The quasi-fine particle high dispersion treatment means group 2-C1 is provided in the coating chamber 2-B1.

Device Configuration 6 FIG. 5 (f) is a block diagram illustrating the configuration of a sixth device for producing coated high pressure type boron nitride quasi-fine particles. This apparatus of the present example is a manufacturing apparatus body 2 of a coating apparatus.
A, a coating chamber 2-B1, a coating space 2-B2, a coating start region 2-B3, a quasi-fine particle high dispersion treatment means group 2-C1, and a recovery means 2-D. A coating chamber 2-B1 is provided in the dispersion space of the quasi-fine particle high dispersion treatment means group 2-C1.

Apparatus Configuration 7 FIG. 5 (g) is a block diagram illustrating the configuration of a seventh apparatus for producing coated high pressure type boron nitride quasi-fine particles. This apparatus of the present example is a manufacturing apparatus body 2 of a coating apparatus.
A, coating chamber 2-B1, coating space 2-B2, coating start region 2-B3, quasi-fine particle high dispersion treatment means group 2-C1, recovery means 2-D, re-coating supply means 2-E. .
The coated quasi-fine particles after coating are conveyed from the collection means 2-D to the high dispersion treatment means group 2-C1 by the re-coating supply means 2-E, and the coating treatment can be repeated. The coated high-pressure type boron nitride quasi-fine particles are produced by any of the apparatuses having such a constitution.

The coated quasi-fine particles obtained by coating the core particle powder which is the high-pressure type boron nitride quasi-fine particles with the coating-forming substance as described above are coated with the coating-forming substance again, or this re-coating is repeated. You can also In this case, the coated quasi-fine particles are sent to the recoating supply means. Here, the re-coating supply means means for conveying the coated quasi-fine particles after coating to the quasi-fine particle high dispersion treatment means group for performing re-coating. Specifically, it is a means provided with (a) a collecting means for collecting the coated quasi-fine particles, and (b) a coated particle conveying means for conveying the coated quasi-fine particles from the collecting means to the quasi-fine particle high dispersion treatment means group. . Alternatively, (a) a collecting means for collecting the coated quasi-fine particles, (b) a coated particle conveying means for conveying the coated quasi-fine particles from the collecting means to the quasi-fine particle high dispersion treatment means group,
(c) and means for classifying the coated quasi-fine particles after coating to classify the coated particles. When the coating amount is large, the particle size distribution of the core particle powder before coating and the particle size distribution of the coated quasi-fine particles after coating change. Therefore, it is effective to adjust the particle size distribution of the coated quasi-fine particles after coating by the coated particle classification means and perform the recoating treatment. This recoating process can be repeated as necessary, and the coating amount of the coating forming substance can be set to a desired value. Further, this coating treatment can be repeated by changing the type of the coating forming substance, and in this way, it is also possible to multiply coat a substance of a plurality of components as a coating forming substance.

The apparatus for producing coated quasi-fine particles used in the present invention is an apparatus for producing coated quasi-fine particles in which the coating-forming substance is coated on the particle surface of the core particle powder by a vapor phase method in which a gas phase is passed. There is no limit. For example, as a chemical vapor deposition (CVD) apparatus, a thermal CVD apparatus, a plasma CVD apparatus, a CVD using an electromagnetic wave (visible light CVD, laser CVD,
UV CVD, infrared CVD, far infrared CVD) device,
As the MOCVD device or the like or the physical vapor deposition (PVD) device, a vacuum vapor deposition device, an ion sprinkling device, an ion plating device or the like can be applied. More specifically, for example, a particle whose surface is coated with ultrafine particles disclosed in JP-A-3-75302 and a coated particle manufacturing apparatus described in the manufacturing method thereof are suitable.

As described above, according to the present invention, the core particle powder which is the quasi-fine particles of high pressure type boron nitride, or the core particle powder which is mainly the quasi-fine particles is charged into the coating space and is produced through the gas phase. And / or contacting the coating substance precursor and / or the gas-phase coating substance precursor with the particles of the core particle powder.
Alternatively, high-pressure type boron nitride quasi-fine particles coated by coating the surfaces of the particles of the core particle powder with a coating material by collision are produced. The general process is as follows.

I (A) Particles of a quasi-fine particle core particle powder having an average particle size of more than 10 μm in a volume-based frequency distribution or a core particle powder mainly composed of quasi-fine particles by means of a group of means for highly dispersing quasi-fine particles Dispersing step of dispersing particles of particle powder in air to obtain a particle / gas mixture of highly dispersed core particle powder, (B) Particle / gas mixture of highly dispersed core particle powder dispersed in this dispersing step A coating step of contacting and / or colliding the particles of the core particle powder with the coating forming material precursor in the coating start region of the coating space in a dispersed state in which the degree of dispersion β is a value in the above range. , The coating method provided.

II (A) Particles of quasi-fine particle core particle powder having an average particle diameter of more than 10 μm in the volume-based frequency distribution or particles of core particle powder mainly composed of quasi-fine particles A group of quasi-particulate high-dispersion processing means that realizes the degree of dispersion β of the particles of the core-particle powder of the particle / gas mixture of the highly-dispersed core particle powder dispersed by the high-dispersion processing means group within the above range. A dispersion step of dispersing in air into a particle / gas mixture of highly dispersed core particle powder, (B) of a particle / gas mixture of highly dispersed core particle powder dispersed in this dispersion step A coating method including a coating step of starting coating by bringing particles into contact with and / or colliding with a coating-forming substance precursor in a coating start region of a coating space in a dispersion state in which the degree of dispersion β is a value in the above range. .

III (A) Particles of quasi-fine particle core particle powder having an average particle size of more than 10 μm in volume-based frequency distribution or particles of core particle powder mainly composed of quasi-fine particles By means of a group of fine particle high-dispersion processing means for realizing the dispersion degree β of the particles of the particle / gas mixture of the highly-dispersed core particle powder dispersed by the high-dispersion processing means group within the above range Dispersing step of dispersing in air to form particles / gas mixture of highly dispersed core particle powder, (B) Particles of highly dispersed core particle powder / particles of core particle powder of gas mixture dispersed in this dispersing step Transporting step for directly transporting (C) to the coating step
Forming coating in the coating start region of the coating space in a dispersed state in which the degree of dispersion β is in the above range of values, the particles of the highly dispersed core particle powder and the particles of the core particle powder of the gas mixture transported in this transportation step A coating method including a coating step of contacting and / or colliding with a substance precursor to start coating.

IV (A) Particles of quasi-fine particle core particle powder having an average particle diameter of more than 10 μm in volume-based frequency distribution or particles of core particle powder mainly composed of quasi-fine particles A group of quasi-particulate high-dispersion processing means that realizes the degree of dispersion β of the particles of the core-particle powder of the particle / gas mixture of the highly-dispersed core particle powder dispersed by the high-dispersion processing means group within the above range. A dispersion step of dispersing in air into a particle / gas mixture of highly dispersed core particle powder, (B) of a particle / gas mixture of highly dispersed core particle powder dispersed in this dispersion step 1 is selected from a hollow member inevitable for transportation of particles, an intermediate member including a member forming a hollow, and a pipe.
A transporting process that transports through various types or more members,
(C) The coating start region of the coating space in the dispersed state in which the particles of the highly dispersed core particle powder and the core particle powder of the gas mixture of the gas mixture transported in this transportation step have the dispersity β within the above range. In the coating method, the coating step of contacting and / or colliding with the coating material precursor to start coating is performed.

V (A) Particles of quasi-fine particle core particle powder having an average particle size of more than 10 μm in the volume-based frequency distribution or particles of core particle powder mainly composed of quasi-fine particles A group of quasi-particulate high-dispersion processing means that realizes the degree of dispersion β of the particles of the core-particle powder of the particle / gas mixture of the highly-dispersed core particle powder dispersed by the high-dispersion processing means group within the above range. A dispersion step of dispersing in air into a particle / gas mixture of highly dispersed core particle powder, (B) of a particle / gas mixture of highly dispersed core particle powder dispersed in this dispersion step High-dispersion core particle powder, high-dispersion core particle powder for maintaining the air-dispersed state of particles of highly dispersed core particle powder / gas mixture core particle powder in which particles are dispersed in the air with this dispersion performance Core particles of body particles / gas mixture In the air dispersion promoting means, the low-dispersion core-particle powder particles / gas mixture is separated in the mixture of the core-particle powder particles and the gas, and the core-particle powder particles are mainly dispersed in a single-particle state. A conveying step of conveying the particles / gas mixture of the highly dispersed core particle powder present therein to the coating step via one or more particles / gas mixture selecting means of the highly dispersed core particle powder, (C ) Coating the particles of the highly dispersed core particle powder / particles of the gas mixture core particle powder transported in this transportation step in the coating start region of the coating space in a dispersed state with the degree of dispersion β within the above range. A coating method, which comprises a coating step of contacting and / or colliding with a forming substance precursor to start coating.

In all of the above I to V, it is preferable that
Highly dispersed core particles obtained by dispersing particles of quasi-fine particle core particle powder having a volume-based frequency distribution of more than 10 μm or particles of core particle powder mainly composed of quasi-fine particles by a quasi-fine particle high dispersion treatment means group. Core particles of powder particles / gas mixture Core particles of highly dispersed core particles powder / gas mixture in the space region that realizes the degree of dispersion β of powder particles within the above range. The coating start region of the coating space is located in the space region including the surface through which all the particles of the particle powder pass, or the quasi-fine particle core particle powder whose average particle size exceeds 10 μm in the volume-based frequency distribution Particles or particles of a core particle powder mainly composed of quasi-fine particles are dispersed by means of a quasi-fine particle high dispersion treatment means group. A space that realizes that Of the band, in the space region including a surface all particles passing through the recovery in the recovery of the recovery means, or to position the coating start region of the coating space, or the I and
In II, the volume-based frequency distribution has an average particle size of 10 μm
Particles of a highly dispersed core particle powder in which particles of a quasi-fine particle core particle powder or particles of a core particle powder mainly composed of quasi-fine particles are dispersed by a quasi-fine particle high dispersion treatment means group In the dispersion step of dispersing the particles in the air into a particle / gas mixture of highly dispersed core particles powder by a quasi-fine particle high-dispersion treatment means group that realizes the degree of dispersion β of the particles of the powder within the range described above. Part or more and part or more of the coating step,
This is done by sharing a part or more of the space.

The above-mentioned coated high-pressure type boron nitride quasi-fine particles may form aggregates in a contact state via the coating forming substance of the coated particles. The powder composed of the coated high-pressure boron nitride quasi-fine particles is an agglomerate in which the coated quasi-fine particles in the state of single particles and several to tens of the coated quasi-fine particles in the state of single particles are in contact with each other. Further, it is composed of aggregates in which a large number of coated quasi-fine particles in a single particle state are in contact with each other, and the shape and size thereof are nonuniform and irregular. It is preferable that the aggregated mass of the coated quasi-fine particles in a single particle state is crushed and / or crushed before being subjected to molding or sintering treatment. For crushing and / or crushing the coated aggregate of the high-pressure type boron nitride quasi-fine particles, various crushing means, for example, a ball mill, a vibrating ball mill, a mortar,
Jet mill etc. can be used. Further, the coated quasi-fine particles in the single particle state and the aggregate of the coated particles in the single particle state are selectively separated, and only the coated quasi-fine particles in the single particle state are molded or sintered. You may use for processing.

According to the present invention, the coated high-pressure type boron nitride quasifine particles or a mixture containing the same obtained as described above is sintered at a pressure of 2000 MPa or more and at a high temperature, or is coated with this. The high-pressure type boron nitride quasi-fine particles or a mixture containing the particles are sintered under a pressure of less than 2000 MPa and a temperature of not more than 1850 ° C. under high-pressure type boron nitride, which is not thermodynamically stable but metastable at a pressure and temperature. Or a mixture of the coated high pressure type boron nitride quasi-fine particles and a binder in a volume ratio of 1 to 90:99 to 10, which is higher than 1850 ° C. at a pressure of less than 2000 MPa. No high-pressure type boron nitride particles are sintered to a density of 85% or more under thermodynamically metastable conditions.
High-pressure type boron nitride which does not exceed 850 ° C is not thermodynamically stable, but is sintered under the firing conditions of metastable pressure and temperature.

When a substance exhibiting another function is added, this substance is in the form of powder, plate, or particles, and more specifically, the periodic table 1a, 2a, 3a, 4
a, 5a, 6a, 7a, 1b, 2b, 3b, 4b, 5
Group b, 6b, 7b, and 8 metals, semiconductors, semimetals, rare earth metals, and oxides, nitrides, carbides, oxynitrides, oxycarbides, carbonitrides, oxycarbonitrides, borides, and silicides thereof One or more selected from, for example Al, B, Si,
Fe, Ni, Co, Ti, Nb, V, Zr, Hf, T
a, W, Re, Cr, Cu, Mo, TiAl, Ti ₃ A
1, TiAl ₃ , TiNi, NiAl, Ni ₃ Al, Si
C, B ₄ C, Cr ₃ C ₂ , TiC, ZrC, WC, W ₂ C,
HfC, TaC, Ta ₂ C, NbC, VC, Mo ₂ C, S
i ₃ N ₄ , TiN, ZrN, Si ₂ N ₂ O, AlN, Hf
N, V _x N (x = 1 to 3), NbN, TaN, Ta ₂ N,
TiB, TiB ₂ , ZrB ₂ , VB, V ₃ B ₂ , VB ₂ , N
bB, NbB ₂ , TaB, TaB ₂ , MoB, MoB ₂ ,
MoB ₄ , Mo ₂ B, WB, W ₂ B, W ₂ B ₅ , LaB ₆ , B
P, B ₁₃ P ₂ , MoSi ₂ , Al ₂ O ₃ , ZrO ₂ (Y
₂ O ₃ , MgO or CaO stabilizer added partially stabilized zirconia: PSZ or tetragonal zirconia polycrystal: T
ZP), MgAl ₂ O ₄ (spinel), and Al ₂ SiO ₅ (mullite).

Further, the auxiliary may be a fibrous substance. The fibrous substance to be mixed with the coated high-pressure boron nitride quasi-fine particles is a substance composed of at least one kind of metal or compound having a minor axis of 500 μm or less and a ratio of the major axis to the minor axis of 2 or more, A rod-like substance having a minor axis of 500 μm or less and a ratio of the major axis to the minor axis of 2 or more, and / or continuous fibers which are continuous fibers formed by melt spinning into fibers and / or crystals themselves have a fiber shape. It consists of short fibers that are self-supporting fibers and / or whiskers that are crystallized in one direction to form fibers. It is defined that whiskers (whisker crystals) do not undergo the phenomenon of phase change or chemical reaction affecting the entire volume in the formation of the whiskers and / or phase change or chemical changes affecting the entire volume. By growing only one crystal plane of the generated crystal, a whisker in a broad sense and / or a cross-sectional area that indicates a single crystal that has become a long needle crystal is 8 ×.
There are whiskers that are single crystals with a length of 10 ⁻⁵ in ² or less and a length of 10 times or more the average diameter.

As the fibrous substance, the periodic table 1a, 2
a, 3a, 4a, 5a, 6a, 7a, 1b, 2b, 3
At least one kind of compound containing at least one kind selected from the group consisting of b, 4b, 5b, 6b, 7b, and 8 metals, semiconductors, semimetals, rare earth metals, and nonmetals is included. A fibrous substance having a minor axis of 500 μm or less and a ratio of the major axis to the minor axis of 2 or more is used. Specifically, the periodic table 1a, 2
a, 3a, 4a, 5a, 6a, 7a, 1b, 2b, 3
b, 4b, group 8 metals, semiconductors, semi-metals, rare earth metals,
And its oxides, nitrides, carbides, oxynitrides, oxycarbides, carbonitrides, oxycarbonitrides, borides, and silicides, with a minor axis of 500 μm or less and a major axis relative to the minor axis. A fibrous material having a shape having a ratio of 2 or more is used. Suitably, for example, Al, B, Si, Fe, N
i, Co, Ti, Nb, V, Zr, Hf, Ta, W, R
e, Cr, Cu, Mo, TiAl, Ti ₃ Al, TiA
l ₃ , TiNi, NiAl, Ni ₃ Al, SiC, B
₄ C, Cr ₃ C ₂ , TiC, ZrC, WC, W ₂ C, Hf
C, TaC, Ta ₂ C, NbC, VC, Mo ₂ C, Si ₃
N ₄ , TiN, ZrN, Si ₂ N ₂ O, AlN, HfN,
V _x N (x = 1 to 3), NbN, TaN, Ta ₂ N, Ti
B, TiB ₂ , ZrB ₂ , VB, V ₃ B ₂ , VB ₂ , Nb
B, NbB ₂ , TaB, TaB ₂ , MoB, MoB ₂ , M
oB ₄ , Mo ₂ B, WB, W ₂ B, W ₂ B ₅ , LaB ₆ , B
P, B ₁₃ P ₂ , MoSi ₂ , Al ₂ O ₃ , ZrO ₂ (Y
₂ O ₃ , MgO or CaO stabilizer added partially stabilized zirconia: PSZ or tetragonal zirconia polycrystal: T
ZP), MgAl ₂ O ₄ (spinel), Al ₂ SiO ₅ (mullite), with a minor axis of 500μ
A fibrous substance having a shape of m or less and a ratio of the major axis to the minor axis of 2 or more can be selected.

The coated high-pressure type boron nitride quasi-fine particles used in the present invention coat the surface thereof by the vapor phase method as described above, so that basically there is no limitation on the coating forming substance. If necessary, in designing the material of the coated high-pressure type boron nitride quasi-fine particle sintered body arbitrarily according to the application, before applying this coating, the surface of the high-pressure type boron nitride quasi-fine particle may be of the same type and / or in advance. Different types of coating-forming substances may be coated by the same and / or different coating methods. For example, when forming a coating made of a carbide of a target metal on the surface of the high-pressure type boron nitride quasi-fine particles, the coated high-pressure type boron nitride quasi-fine particles coated with carbon in advance may be used. The method of coating the substance in advance is not particularly limited, but, for example, JP-A-2-
Molten salt dipping method described in JP-A-252660, JP-A-1-
The molten salt disproportionation reaction method described in JP-A-207380, electroplating method, electroless plating method, cladding method, physical vapor deposition method (sputtering method, ion plating method, etc.), chemical vapor deposition method and the like are preferable. . The type of metal of the target metal compound is not particularly limited as long as it is a range applicable as the binder and / or the sintering aid of the present invention.

The coating film formed by the dipping method using the above-mentioned molten salt is a dense, high-hardness, high-melting-point substance, has a function of separating the high-pressure type boron nitride quasi-fine particles from other substances, and is a binder material. The range of choice expands dramatically. The coated high-pressure type boron nitride quasi-fine particles provided with a coating film by the dipping method using this molten salt have a conventional pressure of less than 2000 MPa, and the high-pressure type boron nitride has a thermodynamically metastable pressure and temperature. It is difficult to sinter densely in the manufacturing method of high-pressure type boron nitride-containing high-hardness and high-density composite sintered body depending on the sintering conditions. To the high-pressure type boron nitride quasi-fine particles coated with the coating film, an appropriate amount of a substance that can be applied as a binder that is sufficiently dense and can be sintered to a high hardness by the coating method by the vapor phase method of the present invention is further added. The coating is more suitable for promoting the sintering.

According to the present invention, the surface of the high-pressure type boron nitride quasi-fine particles is coated with a coating material on the surface of the high-pressure type boron nitride quasi-fine particles by mixing with the binder, or the high-pressure type boron nitride quasi-fine particles are mixed. The mixture of the quasi-fine particles and the binder, with the balance being the powder, plate-like substance, particles, etc. and / or the minor axis being 500.
It is also possible to sinter a mixture of a fibrous substance having a shape of not more than μm and having a ratio of the major axis to the minor axis of 2 or more in the powder form or after molding.

The high-pressure type boron nitride is thermodynamically stable only under an ultrahigh pressure, and when the pressure is insufficient at a high temperature, it undergoes a phase transition to a graphite type hexagonal boron nitride (h-BN). . Therefore, a high-pressure type boron nitride sintered body containing high-pressure type boron nitride is used as a graphite type phase (h-B) of high-pressure type boron nitride.
In order to prevent the phase transfer to N) and to sinter the high-pressure boron nitride sintered body densely, the high-pressure boron nitride is thermodynamically stable under an ultrahigh pressure and high temperature exceeding 2000 MPa. Manufactured. Therefore, when the pressure is 2000 MPa or more and the pressure and temperature of the high-pressure boron nitride are thermodynamically stable, the thermodynamic equilibrium line of the phase diagram of the high-pressure boron nitride corresponds to the temperature. Is limited. However, when the pressure is 2000 MPa or more and the high-pressure type boron nitride is not thermodynamically stable, but when metastable pressure and temperature sintering conditions are selected, the thermodynamic equilibrium line of the phase diagram of the high-pressure type boron nitride is used. Temperatures that deviate from the limited region corresponding to the pressure may be acceptable.

On the other hand, when the pressure is less than 2000 MPa, the high-pressure type boron nitride is not thermodynamically stable, but is metastable.
When selecting the sintering conditions of temperature, it should be noted that the high-pressure type boron nitride is in a thermodynamically metastable region because there is a temperature limited corresponding to the pressure. That is, the pressure is 2000
When the sintering condition is selected such that the pressure is less than MPa and the high-pressure type boron nitride is not thermodynamically stable but is metastable, the upper limit of the sintering temperature varies depending on the quality of the high-pressure type boron nitride particles. For example, in the case of cubic boron nitride, according to an experiment under super high pressure by Wakatsuki et al., When cubic boron nitride is thermodynamically metastable even if it is not thermodynamically stable, a phase transition occurs. Since it takes a very long time, it exists in a stable manner,
1200 ° C as the upper limit of the temperature at which it is stable
(Wakatsuki, Ichise, Aoki, Maeda, No. 1
Proceedings of the 4th High-Volume Debate Conference (1972) P78).

Particularly, high-purity high-pressure boron nitride such as PV
Capsule capable of transmitting pressure by using ultra-high purity cubic boron nitride synthesized through a gas phase by D method or CVD method or ultra-high purity cubic boron nitride synthesized by ultra-high pressure for a long time Ultra-high pressure HIP (hot isostatic pressing) sintering or HIP sintering by degassing and encapsulating in PC, or sintering by PC (piston / cylinder) or HP (hot press) firing in vacuum or an inert gas. By concluding,
Even if it is not in a thermodynamically stable state, cubic boron nitride actually exists stably up to 1850 ° C., which is much higher than 1200 ° C. reported by Wakatsuki et al. However, when it exceeds 1850 ° C., it undergoes a phase transition to a graphite type phase in a short time. Further, if high-purity cubic boron nitride in which impurities have been positively removed by conventionally known cubic boron nitride is used, cubic boron nitride exists up to 1700 ° C. by the same sintering method.
Alternatively, if cubic cubic boron nitride, which is conventionally known cubic cubic nitride and does not contain fine particles, preferably 3 μm or more, is used,
By the same sintering method, cubic boron nitride is present up to 1600 ° C. Alternatively, in the case of a conventionally known relatively high-purity cubic boron nitride, 1500
Cubic boron nitride is present up to ° C. However, up to 1400 ° C. is preferable in the case of containing the conventionally known general cubic boron nitride or wurtzite type boron nitride.

Therefore, when the pressure is less than 2000 MPa, the high pressure type boron nitride is not thermodynamically stable, but a metastable pressure.
When selecting the temperature sintering conditions, the upper limit of the sintering temperature is 18
It is 50 ° C. As described above, the temperature at which the high-pressure type boron nitride is not in a thermodynamically stable state and is actually stable depends on the quality of the high-pressure type boron nitride used.
It is necessary to set the sintering temperature according to the quality of the high-pressure boron nitride raw material. When it is necessary to set the sintering temperature close to the temperature corresponding to the quality of the raw material of the high-pressure boron nitride, it is necessary to carefully control the sintering temperature.

The coated high-pressure type boron nitride quasi-fine particle sintered body of the present invention is manufactured by a manufacturing method under two kinds of sintering conditions under different pressures. The apparatus for producing a coated high-pressure type boron nitride quasi-fine particle sintered body, which is sintered at an ultrahigh pressure of 2000 MPa or more and at a high temperature for an appropriate time, is a cubic type, tetra type, girdle type, belt type ultrahigh pressure apparatus, etc. Is applicable and there is no particular limitation. The pressurizing device and pressure for pressurizing the sample with good reproducibility are 2000 MPa or more using various ultrahigh pressure devices such as the cubic ultrahigh pressure device. The sintering temperature may be a little outside the thermodynamically stable region of the cubic boron nitride. However, it is more preferable that the high pressure type boron nitride has a thermodynamic stability range of 200.
Sinter under ultra high pressure of 0 MPa or more and high temperature. Coated high-pressure type boron nitride quasi-fine particles which are sintered at a pressure of less than 2000 MPa and a temperature not exceeding 1850 ° C., and the high-pressure type boron nitride is not thermodynamically stable but is metastable for a suitable time under a sintering condition of pressure and temperature. The sintered body manufacturing apparatus is a PC (piston / cylinder) type ultra-high pressure apparatus, an ultra-high pressure HIP (hot isostatic pressing) apparatus, a HIP apparatus, or an HP.
A (hot press) device or the like can be applied, and there is no particular limitation.

When the PC type ultra high pressure device is used, the pressure may be less than 2000 MPa,
1500 considering the durability of this PC type ultra high pressure device.
It is preferable not to exceed MPa. As a conventionally known technique relating to pressure generation, an ultra-high pressure HIP device is 100
It is possible to apply HIP pressure up to 0 MPa. In the case of HIP equipment and HP equipment excluding this ultra-high pressure HIP equipment, it is 2
Each can be operated up to 00 MPa.

The coated high-pressure boron nitride quasi-fine particle sintered body sintered by the above method is a high-performance sintered body having a highly controlled microstructure. Dense coated high pressure type boron nitride having a Vickers hardness of preferably 600 or more and a density of 85% or more in a coated high pressure type boron nitride quasi fine particle sintered body for the most general use as a mechanical member. A quasi-fine particle sintered body can be manufactured. Preferably, the coated high-pressure type boron nitride quasi-fine particle sintered body has a Vickers hardness of 800 or more and / or a dense high-pressure type boron nitride quasi-fine particle sintered body having a density of 90% or more. We can manufacture ties. More preferably, for example, considering the application to a mechanical member having high wear resistance, the content of relatively high-pressure boron nitride is increased,
Moreover, the Vickers hardness is 10 due to the dense sintering.
A coated high-pressure type boron nitride quasi-fine particle sintered body having a hardness of 00 or higher can be manufactured. For tools and the like that require even higher wear resistance, a high-pressure type boron nitride quasi-fine particle sintered body having a Vickers hardness of 2000 or more is obtained by further increasing the content of the high-pressure type boron nitride and performing dense sintering. Can be manufactured.

The coated high-pressure type boron nitride quasi-fine particles, the coated high-pressure type boron nitride quasi-fine particle sintered body and the method for producing the same according to the present invention will be described below with reference to examples. Example 1 As high pressure type boron nitride quasi fine particles, the average particle size D _M was 17
μm, the volume-based frequency distribution is ([D _M / 2,3D _M /
2], ≧ 90%) cubic boron nitride quasi-fine particles were coated with titanium nitride, which is a nitride of titanium metal. The apparatus used is that shown in FIG. 6 and FIG. 7 which is a partially enlarged view thereof, and is a specific example of the configuration shown in FIG. The apparatus of this example includes a plasma torch 3-A, a plasma chamber 3-a, a cooling bath 3-B for a coating forming substance precursor production chamber, a coating forming substance precursor production chamber 3-b, and a coating chamber cooling bath 3 in a narrow sense. -C, the coating chamber 3-c in a narrow sense, the cooling tank 3-D of the coating quasi-fine particle cooling chamber,
A coating quasi-fine particle cooling chamber 3-d, a supply device 3-E1 on the supply side of the raw material of the coating forming substance, a stirring dispersion machine 3-F1 and an ejector dispersion machine 3-H1 on the supply side of the core particle powder, It is composed of a capillary disperser 107 and a coated quasi-fine particle recovery unit 3-G. The supply device 3-E1 is connected to the supply tank 112 for the raw material powder of the coating-forming substance, and the stirring-type disperser 3-F1 is connected to the supply device 111 equipped with the supply tank for the core particle powder. By definition, the coating chamber in this example is composed of a plasma chamber 3-a, a coating forming substance precursor generation chamber 3-b, a coating chamber 3-c in a narrow sense, and a coating quasi-fine particle cooling chamber 3-d. These are called a coating room in a broad sense. Of the coating chambers in the broad sense, the chamber 3-c in which the coating process is mainly performed is referred to as the coating chamber in the narrow sense.

Semi-fine particle high dispersion treatment means group α in this example
Is a feeder 111 having a feed tank, a stirring type dispersing machine 3-F
1 and an ejector type disperser 3-H1 and a stainless steel capillary disperser 107 having an inner diameter of 4 mm, as shown in FIG.
3B, which is a specific example of the quasi-fine particle high dispersion treatment means group belonging to the configuration shown in FIG. 3B. The quasi-fine particle high dispersion treatment means group has a D _{M of} 17 μm ([D _M / 5,5
D _M ], ≧ 90%), and β ≧ 80% at the time of output can be realized with respect to the core particle powder of the high pressure type boron nitride quasi-fine particles. The thin tube 107 which is the final processing means of the quasi-fine particle high dispersion processing means group is directly connected to the coating chamber 3-C,
Β in the coating start region 3-L1 of 3-L2 of the coating space
It is configured so that ≧ 80% can be realized.

Argon gas is supplied from the supply source 102 to the gas jet port 101 provided on the upper part of the plasma torch 3-A.
Supply at a rate of 0 liters / minute. The argon gas is turned into plasma by the applied high frequency, and forms a plasma flame in the plasma chamber 3-a in the plasma torch 3-A. Feeder 112 equipped with a feed tank for the raw material of the coating forming substance
Average particle size of 2μ which is the raw material of the coating forming material supplied from
The titanium nitride powder of m is carried in a carrier gas 103 of 5 liters / minute, and is introduced into the plasma flame through an inlet 104 of a raw material of a coating forming material provided in a lower portion of the plasma torch 3-A. It is introduced at a rate of minutes, evaporates by the heat of the plasma flame, passes through the gas phase, and becomes a coating material precursor in the coating material precursor production chamber 3-b. Cubic boron nitride core particles having an average particle diameter of 17 μm, which are supplied at 3.0 g / min from a feeder 111 equipped with a core particle powder supply tank,
An ejector-type disperser 3-H1 and a thin-tube disperser, which are dispersed by a stirring-type disperser 3-F1 and carried by a carrier gas 105 supplied at a rate of 5 liters / minute, and by a dispersion gas 106 having a flow rate of 10 liters / minute. It is dispersed into a dispersed state with a degree of dispersion β = 89% by 107 and is introduced into the coating chamber. The cubic boron nitride quasi-fine particles in a highly dispersed state start to contact and / or collide with the coating material precursor in the coating start region 3-L1 of the coating space 3-L2 in a dispersed state of β = 89%.

The thus-produced coated quasi-fine particles whose surface is coated with the coating-forming substance descends together with the gas in the coated quasi-fine particle cooling chamber 3-d, and the coated quasi-fine particle recovery section 3
-Go to G. The product composed of the coated quasi-fine particles is separated from the gas by the filter 110, collected, and taken out. The obtained coated quasi-fine particles, which are cubic boron nitride quasi-fine particles whose surfaces are coated with titanium nitride, are observed with a scanning electron microscope, and as shown in FIG.
In each case, titanium nitride with a thickness of about 0.005 μm was uniformly coated in the form of ultrafine particles. The coating amount of titanium nitride was 5% by volume. As a binder for bonding the cubic boron nitride quasi-fine particles coated with titanium nitride thus obtained, coating was performed under substantially the same conditions as those of the titanium nitride-coated cubic boron nitride quasi-fine particles, and the grain size was 0. 0.5-2μ
A cubic boron nitride fine particle powder composed of fine particles of m (average particle diameter 1 μm) was coated with 15% by volume of titanium nitride to form a coated cubic boron nitride powder. The coated cubic boron nitride quasi-fine particles are 60% by volume, and the particle size is 0.1%.
Cubic boron nitride fine particles coated with fine particles of 5 to 2 μm (average particle diameter 1 μm) were wet mixed with acetone in an amount of 40% by volume, and the mixture was embossed to have an outer diameter of 6 mm and a height of 2 mm. Embedded in a pressure medium having a hexagonal boron nitride (h-BN) compact formed on the outside thereof, at 200 ° C. for 10 ⁻³
Vacuum drying was performed overnight at torr to remove low boiling point impurities.
This was set in a cubic type ultra-high pressure apparatus, first, the pressure was raised to 5.5 GPa at room temperature, and then the temperature was raised to 1450 ° C.
After holding for 30 minutes, the temperature was lowered and the pressure was lowered.

When the obtained sintered body was examined by X-ray diffraction, only cubic boron nitride and titanium nitride were found. An electron micrograph of the polished surface obtained by subjecting the polished surface of the sintered body of Example 1 to ordinary gold vapor deposition for observation (×
5000) is shown in FIG. In the figure, the dark part is cubic boron nitride and the light part is titanium nitride. As is clear from FIG. 9, there are no pores in the sintered body and the relative density is 99
It was possible to sinter to over%. Moreover, there were no unsintered parts at all. Where the coating forming material becomes thin and the cubic boron nitride quasi fine particles and / or the cubic boron nitride fine particles composed of the fine particles are in contact with each other, the cubic boron nitride quasi fine particles and / or the cubic boron nitride fine particles are in contact with each other. Broke through the coating, sinter and bond directly. Other than this, titanium nitride is uniformly distributed around cubic boron nitride quasi-fine particles, and coated cubic boron nitride quasi-fine particles are dense and have a uniform and extremely highly controlled distribution characteristic. It turns out that Moreover, the cubic boron nitride particles are also characterized in that they have no grain growth as compared with the cubic boron nitride powder as the raw material. Such a sintered body having an extremely highly controlled microstructure could not be produced in the past. As described above, although cubic boron nitride is originally extremely difficult to sinter, the coated high-pressure boron nitride quasi-fine particles of the present invention are
Under industrial-level ultra-high pressure and high temperature, it behaves like particles that are relatively easy to sinter, and forms a fine structure that is dense, strong, and extremely highly controlled.

Example 2 Cubic boron nitride quasi-fine particles having an average particle size D _M of 17 μm and a volume-based frequency distribution of ([D _M / 2,3D _M / 2], ≧ 90%) were coated with titanium metal. . The equipment used is
FIG. 10 and FIG. 11 which is a partially enlarged view of FIG. 10 are specific examples of the configuration shown in FIG. The configuration of the apparatus for producing the coating material precursor of this example is the same as that of the first embodiment. The quasi-fine particle high dispersion treatment means group α is composed of a feeder 214 having a feed tank, a stirring type dispersing machine 5-F1, a narrow tube dispersing machine 211, and a dispersing machine 5-H2 using a collision plate. FIG. 3A is a specific example of the quasi-fine particle high dispersion treatment means group belonging to the configuration shown in FIG. 3B. The thin tube disperser 211 is made of stainless steel having an inner diameter of 4 mm. The disperser 5-H2 using the collision plate, which is the final dispersion means of the quasi-fine particle high dispersion treatment means group α, has a structure in which a collision plate 213 made of SiC is installed by a holder 212 made of stainless steel. The disperser 5-H2 using this collision plate is provided in the narrowly-defined coating chamber 5-c, and the quasi-fine particle high dispersion treatment means group α and the narrowly-defined coating chamber 5-c have a common space. ing. Further, the coating space 5-L1 and the coating start region 5-L2 of the coating space are provided in the coating chamber 5-c in a narrow sense. The quasi-fine particle high dispersion treatment means group of this device has an average particle diameter D _M of 17 μm and a volume-based frequency distribution of ([D _M / 5,
5D _M ], ≧ 90%) of the core particle powder can be dispersed at a dispersity β ≧ 80% immediately after collision with the collision plate 215 of the disperser 5-H2 using the collision plate which is the final dispersion treatment. . Therefore, the coating is started in the state where the degree of dispersion β ≧ 80%.

20 l / min of argon gas is supplied from the supply source 202 to the gas ejection port 201 provided on the upper part of the plasma torch 5-A. This argon gas is turned into plasma by the applied high frequency, and the plasma torch 5
-A plasma flame is formed in the plasma chamber 5-a in A. From a feeder 215 equipped with a feed tank for the raw material of the coating-forming substance.
The powder of titanium metal having an average particle diameter of 25 μm, which is the raw material of the coating forming material supplied at 4 g / min, was carried by the carrier gas 203 at 5 liters / min and the plasma torch 5-A.
Feeding port 204 for the raw material of the coating forming material provided at the bottom of
Is introduced into the plasma flame, vaporized by the heat of the plasma flame and passes through the gas phase, and then the coating forming substance precursor generation chamber 5-b.
It becomes a coating material precursor. Cubic boron nitride core particles supplied at 2.0 g / min from a feeder 214 equipped with a core particle powder supply tank were dispersed by a stirring disperser 5-F1 at a rate of 20 liters / min. The carrier gas 205 supplied supplies the carrier gas 205, and after passing through the narrow tube disperser 211, it is dispersed in the air to a dispersity β = 89% by the disperser 5-H2 using a collision plate provided in the coating chamber. The highly dispersed cubic boron nitride quasi-fine particles and β = 8 with the coating substance precursor in the coating start region 5-L1 of the coating space 5-L2.
Start contact and / or collision at 9% dispersion.

The thus-produced coated quasi-fine particles having their surfaces coated with the coating-forming substance descend together with the gas in the coating quasi-fine particle cooling chamber 5-d, and the coated quasi-fine particle recovery section 5
-Go to G. The product composed of the coated quasi-fine particles is separated from the gas by the filter 210 and collected and taken out. The obtained coated quasi-fine particles, which were cubic boron nitride quasi-fine particles whose surfaces were coated with titanium metal, were observed by a scanning electron microscope. As a result, all the individual particles are uniformly about 0.005 μm. The titanium metal was coated in the form of ultrafine particles. The titanium metal coating amount was 10% by volume. As a binder for binding the cubic boron nitride quasi-fine particles coated with titanium thus obtained, titanium nitride coating was performed under substantially the same conditions as the titanium-coated cubic boron nitride quasi-fine particles, and the grain size A cubic boron nitride fine particle powder consisting of fine particles having a particle size of 0.5 to 2 μm (average particle diameter 1 μm) was coated with 15% by volume of titanium nitride, and a coated cubic boron nitride powder was used. 60% by volume of the above-mentioned coated cubic boron nitride quasi-fine particles, and the above grain size of 0.5-0.5%.
Cubic boron nitride fine particles coated with fine particles of 2 μm (average particle diameter 1 μm) were wet mixed with acetone in an amount of 40% by volume, and the mixture was embossed into an outer diameter of 6 mm and a height of 2 mm. Embedded in a pressure medium with hexagonal boron nitride (h-BN) compacts placed outside, 200 ° C, 10 ^-3 torr
Vacuum drying was carried out for 24 hours to remove low boiling point impurities. This was set in a cubic type ultra-high pressure apparatus, first, the pressure was raised to 5.5 GPa at room temperature, and then the temperature was raised to 1450 ° C.
After holding for minutes, the temperature was lowered and the pressure was lowered.

When the obtained sintered body was examined by X-ray diffraction, only cubic boron nitride and TiN and TiB ₂ were found. The sintered body could be densely sintered to a relative density of 99% or more. According to X-ray quantitative analysis, this sintered body had a volume ratio of cubic boron nitride, TiN and TiB ₂ of about 87%, 10% and 3%, respectively. Similar to the sintered body of Example 1, this sintered body formed a dense, strong and extremely highly controlled microstructure.

Example 3 Cubic boron nitride quasi-fine particles having an average particle diameter D _M of 17 μm and a volume-based frequency distribution of ([D _M / 2,3D _M / 2], ≧ 90%) were coated with zirconium metal. . The apparatus used is that shown in FIG. 12 and FIG. 13 which is a partially enlarged view thereof, and is a specific example of the configuration shown in FIG. 5 (b).
The configuration of the apparatus for producing the coating material precursor of this example is the same as that of the first embodiment. The quasi-fine particle high dispersion treatment means group α includes a feeder 313 having a supply tank, a stirring type dispersing machine 6-F1 which is a dispersing means, and a cyclone 6-I which is a means for selecting a particle / gas mixture of highly dispersed core particle powder. It consists of
FIG. 3B shows a specific example of the configuration shown in FIG. The cyclone 6-I highly dispersed core particle powder particle / gas mixture discharge portion is a pipe 307 inevitable for transportation.
Is connected to the coating chamber 6-c in a narrow sense, and the discharge part of the low-dispersion core particle powder portion is a stirring pipe disperser 6-F1 with a conveying pipe 310 through a hopper 6-J and a rotary valve 6-K. Connected to. According to the quasi-fine particle high dispersion treatment means group of the present apparatus, the average particle diameter D _M is 1 as the volume-based particle size distribution.
At 7 μm, the volume-based frequency distribution is ([D _M / 5,5D _M ],
≧ 90%) of the particles of the core particle powder at the discharge portion of the cyclone 6-I high-dispersion core particle powder flow, which is the final processing means.
The degree of dispersion β can be dispersed to ≧ 85%. A coating space 6-L2 and a coating start region 6-L1 of the coating space are provided in the coating chamber 6-c in a narrow sense as shown in FIGS. 6-C and 6-
The decrease in the dispersion degree β due to the pipe 307, which is unavoidable for the transportation due to the restriction of the flange portion for coupling D, can be kept small. Therefore, the degree of dispersion β ≧
The coating starts at 80%.

Argon gas is supplied from the supply source 302 to the gas outlet 301 provided on the upper part of the plasma torch 6-A.
Supply at 0 l / min. This argon gas is turned into plasma by the applied high frequency, and the plasma torch 6
-A plasma flame is formed in the plasma chamber 6-a in A. From a feeder 314 equipped with a feed tank for the raw material of the coating forming material.
The zirconium powder, which is the raw material of the coating forming material supplied at 5 g / min, is carried by the carrier gas 303 of 5 liters / min, and the raw material inlet 304 of the coating forming material provided in the lower part of the plasma torch 6-A. Is introduced into the plasma flame, evaporates due to the heat of the plasma flame, passes through the gas phase,
It becomes a coating material precursor in the coating material precursor production chamber 6-b. Cubic boron nitride core particles supplied at 2.0 g / min from a feeder 313 equipped with a core particle powder supply tank are:
Disperse with a stirring type disperser 6-F1 to obtain 15 liters /
The carrier gas 305 is carried by the carrier gas 305 and is conveyed to the cyclone 6-I through the pipe 306. Cyclone 6-
I was adjusted so that the maximum particle size on the fine powder side was 20 μm, and a particle-gas mixture of highly dispersed core particle powder in a dispersed state of β = 92% mainly composed of single particles was used for transportation. The gas is discharged from the discharge port 308 to the coating chamber 6-c in a narrow sense through the inevitable pipe 307. On the other hand, the low dispersion core particle powder portion selectively separated by the cyclone 6-I is
After passing through J and the rotary valve 6-K, the carrier gas 309 of 10 liter / min conveys the inside of the pipe 310, and feeds it back to the stirring type dispersing machine 6-F1.

The highly dispersed cubic boron nitride quasi-fine particles are
In the coating start region 6-L1 of the coating space 6-L2, contact and / or collision start with the coating material precursor in a dispersed state of β = 89%. The coated quasi-fine particles, the surfaces of which have been coated with the coating-forming substance, thus generated, descend in the coating quasi-fine particle cooling chamber 6-d together with the gas and reach the coated quasi-fine particle recovery unit 6-G. The product composed of the coated quasi-fine particles is separated from the gas by the filter 312, collected and taken out. The obtained coated quasi-fine particles, which are coated cubic boron nitride quasi-fine particles having a surface coated with zirconium, are observed by a scanning electron microscope, and all the individual particles are uniformly 0. Zirconium of about 005 μm was coated in the form of ultrafine particles. The zirconium coverage was 10% by volume.

As a binder for bonding the zirconium-coated cubic boron nitride quasi-fine particles thus obtained, titanium nitride coating was performed under substantially the same conditions as those of the titanium nitride-coated cubic boron nitride quasi-fine particles, Diameter 0.5-2 μm
A cubic cubic boron nitride fine particle powder composed of fine particles (average particle diameter 1 μm) was used, and a cubic cubic boron nitride powder coated with 15% by volume of titanium nitride was used. The above-mentioned coated cubic boron nitride quasi-fine particles are 30% by volume, and the coated cubic boron nitride fine particles composed of the above-mentioned fine particles having a particle size of 0.5 to 2 μm (average particle diameter 1 μm) are 70% by volume. Is wet mixed with acetone and the outer diameter is 6 mm and the height is 2 mm.
, And hexagonal boron nitride (h-B
N) Embedded in a pressure medium in which the molded body is placed,
Vacuum drying was carried out at 10 ⁻³ torr for one day to remove low boiling impurities. This was set in a cubic type ultra-high pressure apparatus, first, the pressure was raised to 5.5 GPa at room temperature, then the temperature was raised to 1450 ° C., the temperature was held for 30 minutes, and then the temperature was lowered to lower the pressure. When the obtained sintered body was examined by X-ray diffraction, cubic boron nitride, Z
Only rN, ZrB ₂ , and TiN were found. The sintered body could be densely sintered to a relative density of 99% or more. According to the X-ray quantitative analysis, this sintered body is cubic boron nitride, Zr
The volume ratio of N, ZrB ₂ , and TiN is about 86, respectively.
%, 2%, 1% and 11%. The sintered body formed a microstructure that was dense, strong, and extremely highly controlled.

Example 4 The coated cubic boron nitride quasi-fine particles obtained by coating with the apparatus of Example 1 under substantially the same conditions as in Example 1 and having a coating of 50% by volume of alumina were obtained. Diameter 8 mm, thickness 5
Molded to a size of 10 mm, the molded body was placed in a capsule made of Pyrex glass filled with h-BN powder, and 10 ⁻⁶
After degassing at torr, 400 ° C. for 12 hours, it was sealed. This capsule was placed in a HIP device using argon gas as a pressure medium, and sintered at a sintering temperature of 1200 ° C. and a sintering pressure of 150 MPa for 3 hours for sintering. Thereafter, the furnace was cooled, the pressure was released, and the sintered body was taken out. When the crystal phase of the sintered body was examined by powder X-ray diffraction, diffraction peaks other than those of cubic boron nitride and α-alumina were not recognized. The sintered body formed a microstructure that was dense, strong, and extremely highly controlled.

Example 5 Using the apparatus of Example 1, coating was performed under substantially the same conditions as in Example 1 to obtain coated cubic boron nitride quasi-fine particles coated with 10% by volume of titanium nitride. . As the binder for the coated cubic boron nitride quasi-fine particles, high-purity and easily-sinterable alumina (alumina powder described in JP-A-63-151616) was used and sintered. That is, 40% by volume of the coated cubic boron nitride quasi-fine particles, as a binder, a high-purity and easily-sinterable alumina powder having an average particle size of 0.2 μm described in JP-A-63-151616. 53.4% by volume, and magnesia (MgO) and titania (TiO _x , x = 1) as a sintering aid for this alumina powder.
~ 2) are prepared in a volume ratio of 0.6% and 1.0%, respectively, and these are mixed in an alumina ball mill.
Mix wet in acetone for 2 hours. Then 10 ^-6 tor
The mixed powder was vacuum dried at r and 200 ° C. Then
It is stamped and molded into a disk shape with a diameter of 16 mm and a thickness of 5 mm, and this molded body is placed in a Pyrex glass capsule filled with h-BN powder and degassed at 10 ^-6 torr, 400 ° C. for 12 hours. Enclosed. This capsule was placed in a HIP device using argon gas as a pressure medium, and sintered at a sintering temperature of 1300 ° C. and a sintering pressure of 150 MPa for 3 hours for sintering. Thereafter, the furnace was cooled, the pressure was released, and the sintered body was taken out. X
When the crystal phase of the sintered body of Example 5 was examined by line diffraction, no diffraction peaks other than those of cubic boron nitride, titanium nitride and α-alumina were observed. Sintered body has a relative density of 9
It could be sintered finely to 9% or more. The sintered body is dense and strong,
And formed a very highly controlled microstructure.

[0124]

EFFECTS OF THE INVENTION According to the present invention, (1) the core particle powder having an average particle size of more than 10 μm and 20 μm or less in the volume standard frequency distribution is mainly present in the air in the form of a single particle. Whether the particles of the core particle powder in the particle / gas mixture of the dispersed core particle powder are in a highly dispersed state with a dispersity β of 80% or more,
Or (2) A particle / gas mixture of highly dispersed core particle powder in which particles of the core particle powder having an average particle size of more than 20 μm and 50 μm or less in the volume-based frequency distribution mainly exist in the air in a single particle state. The particles of the core particle powder are in a highly dispersed state having a dispersity β of 90% or more, or (3) the core particle powder having an average particle diameter of more than 50 μm and 300 μm or less in the volume standard frequency distribution. Particles of high-dispersion core particle powder that are mainly present in the air in the form of a single particle-The particles of the core particle powder in the gas mixture are in a highly dispersed state with a dispersity β of 95% or more. Or (4) Particles / gas of highly dispersed core particle powder in which particles in the core particle powder having an average particle diameter of more than 300 μm and 800 μm or less in the volume standard frequency distribution are mainly present in the air in a single particle state. Whether the particles of the core particle powder in the mixture are in a highly dispersed state with a dispersity β of 97% or more, Is (5) Core particles with a volume-based frequency distribution and an average particle size of more than 800 μm. The particles of the powder are mainly in the form of a single particle in the air. Highly dispersed core particles The particles of the powder / core particles in the gas mixture. By contacting or colliding the particles of the powder with the coating substance precursor in a highly dispersed state having a dispersity β of 99% or more, the surface of the powder is coated with the coating substance in a single particle state. High-pressure type boron nitride quasi-fine particles are obtained. The coated high-pressure type boron nitride quasi-fine particles were sintered under high pressure with the quasi-fine particles themselves or together with the binder, whereby the microstructure was dense and extremely highly controlled, containing substantially no graphite type phase. A high-pressure coated boron nitride quasi-fine particle sintered body can be manufactured. In particular, ultra-high pressure HIP device or ultra-high pressure HIP
When the HIP device other than the device is used, it is possible to manufacture a sintered body having a more complicated shape, and the present invention has a great advantage in industrial production.

[Brief description of drawings]

FIG. 1 is a distribution chart of powder particles, (a) shows a dispersion degree β of, and (b) shows a volume of particles having a particle size of D _{1 to} D ₂ of 90.
The particle size vs. volume standard frequency of the powder is shown.

2A to 2C are block diagrams showing a basic configuration of a quasi-fine particle high dispersion treatment means group.

3 (a) to 3 (g) are block diagrams for explaining the configuration of a quasi-fine particle high dispersion treatment means group in more detail.

FIGS. 4A to 4E are views showing a mode in which coating of core particle powder is started. FIG.

5 (a) to (g) are block diagrams illustrating the configuration of an apparatus for producing coated high-pressure boron nitride quasi-fine particles.

FIG. 6 is a diagram showing an apparatus used in Example 1.

FIG. 7 is a partially enlarged view of the device used in the first embodiment.

FIG. 8 is a scanning electron micrograph of the coated quasi-fine particles obtained in Example 1.

9 is an electron micrograph of a polished surface of the sintered body of Example 1. FIG.

FIG. 10 is a diagram showing an apparatus used in Example 2.

FIG. 11 is a partially enlarged view of the device used in the second embodiment.

FIG. 12 is a diagram showing an apparatus used in Example 3;

FIG. 13 is a partially enlarged view of the device used in the third embodiment.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B01J 19/00 N 8822-4G C01B 21/064 Z C04B 35/626 C23C 14/06 J 9271-4K (72) Inventor Haruo Yoshida 2 Onoue-cho, Kita-ku, Nagoya, Aichi, No. 2 Room No. 1406, No. 5 Onoue Danchi (72) Inventor, Masayoshi Kasu, Ninowari 150, Shikafushi-cho, Tsushima City, Aichi Prefecture 2 (72) Inventor Yuki Yamada 3-6-18 Hachiman, Kawashima-cho, Hiki-gun, Saitama Prefecture (72) Tadashi Fuyuki 2-23-16 Midorigaoka, Oi-cho, Iruma-gun, Saitama Prefecture (72) Satoshi Akiyama Kawagoe, Saitama Prefecture 17-22 Inari-cho, Inari-shi (72) Inventor Miaki Hamada 3-4-8 Suehiro-cho, Kawagoe-shi, Saitama (72) Inventor Eisuke Kuroda 2-16-4 Nishi-senba-cho, Kawagoe-shi, Saitama (72 ) Inventor Tadakatsu Nabeya Kana 1095-21 Yamanouchi, Kamakura, Japan (72) Inventor Yukio Sumida 55-520 Nakahara, Yoshida, Watari-cho, Watari-gun, Miyagi Prefecture (72) Kenichi Kimura 2-33-5, Yagiyama-honmachi, Taishiro-ku, Sendai, Miyagi Prefecture Grace Yagiyama No. 502

Claims (9)

[Claims] 1. A coating forming substance precursor and / or a coating forming substance precursor in a vapor phase state produced by introducing a core particle powder composed of quasi-fine particles of high-pressure type boron nitride into a coating space to generate a gas phase. Coated high-pressure boron nitride quasi-fine particles obtained by contacting and / or colliding with the particles of the core particle powder to coat the surface of the particles of the core particle powder with a coating-forming substance, The final treatment means of the fine particle high dispersion treatment means group is
(A) Dispersing means for dispersing particles of core particle powder in air, and (b) Low dispersion core in a mixture of particles of core particle powder and gas in which particles of core particle powder are dispersed in air. Particles of highly dispersed core particle powder that separates the particle powder portion and particles of the core particle powder are mainly present in the air in a single particle state. Particles of highly dispersed core particle powder that selects a gas mixture. The gas mixture selection means and the low-dispersion core particle powder portion selectively separated by the particle / gas mixture selection means of the high-dispersion core particle powder are the final dispersion means of the dispersion means in the quasi-fine particle high-dispersion processing means group, and And / or a means for selecting a particle / gas mixture of a highly dispersed core particle powder, which comprises a feedback means for conveying to a processing means before the final dispersing means, and a means for quasi-fine particle high dispersion processing means selected from the average of volume-based frequency distributions. Particle size is 10 μm
A dispersing step of dispersing particles of the quasi-fine particle core particle powder exceeding the above or particles of the core particle powder mainly consisting of quasi-fine particles into the air to form a particle / gas mixture of the highly dispersed core particle powder, (B) When the average particle size of the core particle powder dispersed in this dispersion step is more than 10 μm and less than 20 μm, the dispersity β is 80% or more, and when the average particle size is more than 20 μm and less than 50 μm, the dispersity β is 90%.
% And more than 50 μm and less than 300 μm, the dispersity β is 9
When it is 5% or more and exceeds 300 μm and 800 μm or less, the dispersity β is 9
A coating step of contacting and / or colliding with the coating forming material precursor in the coating starting region of the coating space in a dispersed state having a dispersity β of 99% or more when it is 7% or more and 800 μm or more; Coated high-pressure type boron nitride quasi-fine particles prepared by the following coating means. 2. Coated high-pressure type boron nitride quasi-fine particles in which the coated high-pressure type boron nitride quasi-fine particles form aggregates in contact with each other through a coating material of the coated high-pressure type boron nitride quasi-fine particles. Crushing and / or crushing the agglomerates of high pressure type boron nitride quasi fine particles, and / or coating the high pressure type boron nitride quasi fine particles agglomerates with primary particle units. The coated high pressure type boron nitride quasi-fine particles according to claim 1, which is prepared by further performing a selective separation step of selectively separating the high pressure type boron nitride quasi-fine particles. 3. Particles of core particle powder consisting of quasi-fine particles of high-pressure boron nitride to be coated with a coating-forming substance, or particles of core particle powder consisting mainly of quasi-fine particles, are immersed in a molten salt bath. According to claim 1 or claim 2, the particles are particles of quasi-fine particle core particles which are coated with one or more coating materials derived from the dipping method, or particles of core particle powder mainly composed of quasi-fine particles. 2. The coated high-pressure type boron nitride quasi-fine particle as described in 2. 4. The coated high-pressure type boron nitride quasi-fine particles have an average particle size of more than 10 μm and 20 μm in a volume-based frequency distribution.
The core particle powder having a particle size of m or less is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to obtain a particle / gas mixture of the highly dispersed core particle powder, and the degree of dispersion β of the particles of the core particle powder Of high-dispersion quasi-fine particles having a dispersion performance of 80% or more, or a volume-based frequency distribution with an average particle diameter of 20 μm
The core particle powder having a diameter of more than 50 μm and not more than 50 μm is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to form a particle / gas mixture of the highly dispersed core particle powder, and the dispersion of the particles of the core particle powder. Of the quasi-fine particle high-dispersion treatment means group having a dispersion performance of making the degree β 90% or more, or the core particle powder having an average particle diameter exceeding 50 μm and 300 μm or less in the volume standard frequency distribution A quasi-particulate high dispersion treatment means group having a dispersibility in which a particle / gas mixture of highly dispersed core particle powder is dispersed in the air by the final treatment, and the degree of dispersion β of the particles of the core particle powder is 95% or more. Or, the volume-based frequency distribution has an average particle size of more than 300 μm and 80
The core particle powder having a particle size of 0 μm or less is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to form a particle / gas mixture of the highly dispersed core particle powder, and the degree of dispersion β of the particles of the core particle powder Of 97% or more of quasi-fine particle high-dispersion treatment means having a dispersion performance, or a volume-based frequency distribution with an average particle diameter of 80
The core particle powder exceeding 0 μm is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to form a particle / gas mixture of the highly dispersed core particle powder, and the degree of dispersion β of the particles of the core particle powder A dispersion process using a group of quasi-particulate high-dispersion treatment means having a dispersion performance of 99% or more is provided, and the particle-gas mixture of the highly-dispersed core particle powder dispersed by the quasi-fine particle high-dispersion treatment means group is directly applied to the coating step. A hollow member unavoidable for transportation from a discharging part that discharges or discharges a particle / gas mixture of highly dispersed core particle powder dispersed by a quasi-fine particle high dispersion treatment means group between the dispersing step and the coating step. , A high-dispersion core particle powder which is conveyed through one or more members selected from an intermediate member made of a member that forms a hollow and a pipe, and / or dispersed in the air with the above-mentioned dispersion performance. Body particle / gas mixture In-air dispersion maintaining means for maintaining the air-dispersed state of the particles in the compound, enhancing the air-dispersed state of the particles in the particles / gas mixture of the highly dispersed core particle powder dispersed in the air with the above-mentioned dispersion performance Air dispersion promoting means, separating low-dispersion core particle powder portion of a mixture of core particle powder particles and gas, and the core particle powder particles mainly exist in the air in a single particle state. Characterized in that it is prepared by transporting the particles / gas mixture of the highly dispersed core particle powder through one or more means for selecting the particles / gas mixture of the highly dispersed core particle powder. The coated high-pressure boron nitride quasi-fine particles according to claim 1. 5. The coated high-pressure type boron nitride quasi-fine particles have a volume-based frequency distribution with an average particle size exceeding 10 μm and 20 μm.
The core particle powder having a particle size of m or less is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to obtain a particle / gas mixture of the highly dispersed core particle powder, and the degree of dispersion β of the particles of the core particle powder Of high-dispersion quasi-fine particles having a dispersion performance of 80% or more, or a volume-based frequency distribution with an average particle diameter of 20 μm
The core particle powder having a diameter of more than 50 μm and not more than 50 μm is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to form a particle / gas mixture of the highly dispersed core particle powder, and the dispersion of the particles of the core particle powder. Of the quasi-fine particle high-dispersion treatment means group having a dispersion performance of making the degree β 90% or more, or the core particle powder having an average particle diameter exceeding 50 μm and 300 μm or less in the volume standard frequency distribution A quasi-particulate high dispersion treatment means group having a dispersibility in which a particle / gas mixture of highly dispersed core particle powder is dispersed in the air by the final treatment, and the degree of dispersion β of the particles of the core particle powder is 95% or more. , Or a particle / gas of a highly dispersed core particle powder, in which a core particle powder having an average particle diameter of more than 300 μm and 800 μm or less in a volume-based frequency distribution is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group. As a mixture, the core particles Quasi particle group of means for high dispersion treatment with a dispersing performance of the body of the dispersity β of the particles and 97% or more,
Alternatively, a core particle powder having a volume-based frequency distribution and an average particle diameter of more than 800 μm is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to obtain a particle / gas mixture of the highly dispersed core particle powder, Particle dispersity β of core particle powder is 99%
It is prepared by performing a part or more of the dispersion step and a part or more of the coating step by the group of quasi-particulate high-dispersion processing means having the above-mentioned dispersion performance by sharing a part or more of the space. The coated high-pressure type boron nitride quasi-fine particles according to claim 1. 6. The coated high-pressure type boron nitride quasi-fine particles have a volume-based frequency distribution with an average particle size of more than 10 μm and 20.
The core particle powder having a particle size of μm or less is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to obtain a particle / gas mixture of the highly dispersed core particle powder, and the degree of dispersion β of the particle of the core particle powder
Is 80% or more, and the average particle size exceeds 50 μm in the volume standard frequency distribution.
The core particle powder having a particle size of μm or less is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to obtain a particle / gas mixture of the highly dispersed core particle powder, and the degree of dispersion β of the particle of the core particle powder
Of 90% or more, the average particle size exceeds 50 μm in the volume-based frequency distribution, and 30
The core particle powder having a particle size of 0 μm or less is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to form a particle / gas mixture of the highly dispersed core particle powder, and the degree of dispersion β of the particles of the core particle powder Of 95% or more, the volume-based frequency distribution has an average particle size of more than 300 μm and 8
The core particle powder having a particle size of 00 μm or less is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to form a particle / gas mixture of the highly dispersed core particle powder, and the degree of dispersion β of the particles of the core particle powder Of 97% or more in a space region, and a core particle powder having an average particle size of more than 800 μm in a volume-based frequency distribution is dispersed in the air by the final treatment of the quasi-fine particle high-dispersion treatment means group to obtain a highly dispersed core particle powder. Particles of the high-dispersion core particle powder in a space region where the particle dispersity β of the core particle powder is 99% or more as a body particle / gas mixture.
The coating start region of the coating space is located in the space region including the surface through which all the particles of the core particle powder in the gas mixture pass, or the average particle size is 1 in the volume standard frequency distribution.
A core particle powder having a particle size of more than 0 μm and not more than 20 μm is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to obtain a particle / gas mixture of the highly dispersed core particle powder. Spatial region with dispersity β of 80% or more, volume-based frequency distribution with average particle size exceeding 20 μm and 50 μm
The core particle powder having a particle size of m or less is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to obtain a particle / gas mixture of the highly dispersed core particle powder, and the degree of dispersion β of the particles of the core particle powder Of 90% or more, the average particle size exceeds 50 μm in the volume-based frequency distribution, and 30
The core particle powder having a particle size of 0 μm or less is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to form a particle / gas mixture of the highly dispersed core particle powder, and the degree of dispersion β of the particles of the core particle powder Of 95% or more, the volume-based frequency distribution has an average particle size of more than 300 μm and 8
The core particle powder having a particle size of 00 μm or less is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to form a particle / gas mixture of the highly dispersed core particle powder, and the degree of dispersion β of the particles of the core particle powder Of 90% or more in a spatial region, and a core particle powder having an average particle size of more than 800 μm in a volume-based frequency distribution is dispersed in the air by the final treatment of the quasi-fine particle high dispersion treatment means group to obtain a highly dispersed core particle powder. In the space area including the surface through which all particles to be recovered by the recovery unit of the recovery means pass, in the space area in which the degree of dispersion β of the particles of the core particle powder is 99% or more. The coated high pressure type boron nitride quasi-fine particles according to claim 1, 2 or 3, wherein a coating start region of the coating space is located. 7. The particle size distribution of the particles of the core particle powder used is a volume standard frequency distribution ([D _M / 5,5D _M ], ≧ 90%) when the average particle size is D _M. The coated high pressure type boron nitride quasi-fine particles according to claim 1, claim 4, claim 5 or claim 6, characterized in that they are present. 8. The coated high-pressure boron nitride quasi-fine particles according to claim 1, claim 2, claim 3, claim 4, claim 5, claim 6 or claim 7, or a mixture containing the same. To
High-pressure boron nitride, which is sintered at a pressure of 2000 MPa or higher and at a high temperature, or the coated high-pressure boron nitride quasi-fine particles or the mixture containing the particles according to the above-mentioned claims is kept at a pressure of less than 2000 MPa and not higher than 1850 ° C. Is not thermodynamically stable, but sinters under sintering conditions of metastable pressure and temperature, or the volume of the coated high-pressure boron nitride quasi-fine particles and the binder is 1 to 9
This binder is a mixture in a ratio of 0:99 to 10, and the binder has a density of 85% at a thermodynamically metastable condition in which high pressure type boron nitride particles which do not exceed 1850 ° C. at a pressure of less than 2000 MPa.
2000M of the above mixture, which is to be sintered above
Coated high-pressure type boron nitride quasi-fine particles characterized in that high-pressure type boron nitride having a pressure of less than Pa and a temperature of not more than 1850 ° C. is not thermodynamically stable, but is sintered under sintering conditions of metastable pressure and temperature. Manufacturing method of sintered body. 9. A coated high pressure type boron nitride quasi fine particle sintered body produced by the method for producing a coated high pressure type boron nitride quasi fine particle sintered body according to claim 8.