JP2020055256A - Method for manufacturing a plurality of fine particle groups - Google Patents

Abstract

To provide a method for manufacturing a plurality of fine particle groups utilizing a carbon-fiber-containing resin body, and having features such as a favorable particle distribution, low cost, resin containment of carbon fiber, and harmlessness.SOLUTION: There is provided a method for manufacturing a plurality of fine particle groups having following steps for converting a carbon-fiber-containing resin body D into fine particle groups with different particle size distributions: (1) a crushing step for crushing the resin body using an airflow crusher 11 to obtain a broad particle group F with a particle size distribution of 1 μm or more and 120 μm or less; (2) a fine particle group B collecting step for sucking a cyclone device 21 provided with a transfer pipe 22, a cyclone part 23, a damper 24, and a final recovery container 26 to collect a fine particle group B; (3) a fine particle group A stay step having a circulation device 31 having an intake port 33, and connected to a halfway of the transfer pipe 22, and for making a fine particle group A stay in a device of the cyclone device 21; and (4) a fine particle group A recovery step for weakening or stopping the suck of the device, and dropping the fine particle group A to recover it.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing at least two kinds of fine particle groups having different particle size distributions, and more specifically, after crushing a structure containing carbon fibers in a resin using a specific crusher, The present invention relates to a "method of producing at least two kinds of fine particle groups having different particle size distributions", which is divided into a fine particle group having a large particle size distribution and a fine particle group having a small particle size distribution.

Carbon fiber reinforced plastics (CFRP) (hereinafter sometimes abbreviated simply as “CFRP”) is a plastic containing carbon fiber as a reinforcing material in a matrix resin and has both strength and lightness. It is used for many purposes.
Carbon fiber reinforced plastic (CFRP) is widely used in various applications by dispersing and containing carbon fibers in a matrix resin such as epoxy resin and heating it under pressure or heating it using microwaves. Have been.

  However, "unnecessary carbon fiber reinforced plastics" such as scraps generated by the above molding; prototypes including failed products; used molded products; etc., are harmful to carbon fibers. Recycling is difficult because it is often a curable resin, and separation of carbon fiber and matrix resin is difficult. For example, with few exceptions (recycling), landfill disposal is mainly performed.

For example, the following is known as the recycling method.
Patent Document 1 discloses that a matrix resin of carbon fiber reinforced plastic (CFRP) is burned into a flaky carbon fiber mass, which is kneaded with a thermoplastic resin chip while being melted, extruded, cut, and cut into pellets. A technique for performing this is disclosed.

Patent Literature 2 discloses a crushed waste carbon fiber reinforced plastic processed so as to have a large constant direction diameter of 3 mm or more and to have a specific radius of curvature.
Further, Patent Document 3 discloses a method for treating waste plastic in which a fiber-reinforced plastic (FRP) chip and a thermoplastic plastic material are kneaded while being heated and melted, and then cooled and cured to form a dumpling-like solid containing fibers. ing.

  Patent Document 4 discloses a first step of producing a detoxifying material by heat-treating a carbon fiber reinforced plastic and burning a matrix resin, and applying a sizing agent to the detoxifying material and kneading the carbon fiber while kneading. There is disclosed a method of recycling a fiber-reinforced plastic, which comprises a second step of pulverizing a recycled material and a third step of pelletizing the recycled material.

  The method of separating carbon fiber of carbon fiber reinforced plastic (CFRP) from its matrix resin is extremely difficult by both combustion treatment and chemical treatment, and even if separation is possible, the separated carbon fiber is a harmful substance. As described above, landfill disposal has been mainly performed with the carbon fiber reinforced plastic as it is for reasons such as increased cost of separation.

Further, even if the matrix resin is heated and melted, the matrix resin is often a thermosetting resin such as an epoxy resin. In addition, even if the combustion treatment can render the carbon fiber harmless and the resulting treated product finer, the cost increase due to the burning treatment is unavoidable. there were.
Further, as described in Patent Literature 2, for example, even if it is attempted to crush and recycle it largely, its application range (usage range and application) is extremely limited due to its size.

Patent Document 5 discloses "manufacture of recycled filled fine particles" in which unnecessary carbon fiber reinforced plastic (CFRP) is converted into fine particles having a wide range of application without exposing (detoxifying) carbon fibers by a specific grinding method without exposing carbon fibers. Methods "are described.
However, in order to expand the range of application (use) and applications, it is necessary to classify fine particles having a broad particle size distribution at an extremely low cost and with high accuracy (separation into coarse powder and fine powder). The processing speed is slow and the cost is high. Further, it is difficult to classify the powder with high accuracy. Particularly, it is difficult for a pulverized carbon fiber reinforced plastic (CFRP), that is, a fine particle group having a broad distribution. There was no classification method).

On the other hand, cyclone-type collectors and classifiers are known, and are mainly used for collecting particles in a gas, but are also used for classifying two or more types of particles.
Patent Document 6 describes a method for separating plants and earth and sand using a cyclone classifier having a special structure. However, although the classification is relatively easy due to the difference in specific gravity between plants and earth and sand, the structure of the equipment is complicated and the cost is high, and carbon fibers with the same specific gravity but different particle size distributions This method has never been applicable to reinforced plastics (CFRP).

Patent Literature 7 describes a method for producing hydraulic lime using fine powder obtained as a raw material by separating volcanic ejecta sedimentary minerals into coarse powder and fine powder using at least two cyclone classifiers.
However, a cyclone classifier having a large number of cyclone classifiers is required, the equipment cost is enormous, and it cannot be applied to carbon fiber reinforced plastic (CFRP).

  The demand for recycling of carbon fiber reinforced plastics (CFRP) is becoming increasingly higher. However, such known techniques increase the cost of the classification process for various re-uses; use of recycled products (fine particles) It was insufficient for reasons such as narrow range, remaining harmfulness of carbon fiber, increased cost due to complicated classification equipment, and insufficient classification accuracy; and there was room for further improvement.

JP-A-7-118440 JP 2000-254919 A JP 2001-030245 A JP 2009-138143 A JP 2018-020500A JP 2014-217817 A JP 2018-002563 A

The present invention has been made in view of the above background art, and has an object to solve the problem of carbon in carbon fiber reinforced plastics (CFRP) (hereinafter sometimes abbreviated simply as “CFRP”). An object of the present invention is to provide a method for effectively utilizing a fiber-containing resin body.
In addition, the classification accuracy is good, a suitable particle size distribution is obtained, the production cost is not required, the apparatus is not large and complicated, the detoxification of carbon fiber is achieved, the carbon fiber is preferably included by resin, and so on. In particular, by providing a "method of producing at least two types of fine particle groups having a suitable particle size distribution in which useful reuse exists". is there.

The present inventor has conducted intensive studies to solve the above-described problems, and as a result, using a specific pulverizer, and, after the pulverization, using a device having a specific cyclone site, if a specific process is performed, It has been found that it is possible to convert them into a specific plurality of fine particle groups.
The “at least two types of fine particle groups having different particle size distributions” obtained in this way greatly expand the range of reusability (application field; type of target object such as sheet; etc.), and the above-mentioned problem is solved. The inventors have found that the present invention can be solved, and have completed the present invention.

That is, the present invention
The carbon fiber-containing resin body is converted into at least two types of fine particle groups having different particle size distributions, that is, a fine particle group A having a particle size distribution of 1 μm to 30 μm and a fine particle group B having a particle size distribution of 3 μm to 120 μm. A method of producing a plurality of fine particle groups to be made,
An object of the present invention is to provide a method for producing a plurality of fine particle groups, which has all of the following steps (1) to (4).
(1) A particle size of the carbon fiber-containing resin body is measured using an “air current pulverizer that has two or more impellers and pulverizes the particles to be pulverized by colliding target particles with a swirling air current generated by rotation of the impellers”. A pulverization step (2) of obtaining a broad particle group having a distribution of 1 μm or more and 120 μm or less “a cyclone device comprising a transfer pipe, a cyclone portion, a damper, and a final recovery container in this order from the airflow pulverizer side”. The cyclone device is operated while suctioning and transferring the broad particle group obtained in the pulverizing step (1) into the cyclone site, and the fine particles belonging to the fine particle group B are collected in the final collection container. Particulate Group B Collection Step (3) Further, the cyclone device is provided with an inlet between the outer peripheral inner wall of the cyclone portion and the central axis, which is connected as an outlet in the middle of the transfer pipe. A fine particle group A that allows the fine particles belonging to the fine particle group A to stay in the cyclone portion and the circulating device without being put in the final collection container during the operation of the cyclone device. Step (4) Close the damper, weaken or stop the operation of the circulating device, weaken or stop the operation of the cyclone device, and drop and collect the fine particle group A. Collection process

  Further, the present invention is a method for producing a fine particle group A containing carbon fibers and a resin and having a particle size distribution of 1 μm or more and 30 μm or less, characterized by using the above “production method of a plurality of fine particle groups”. And a method for producing the fine particle group A.

  Further, the present invention is a method for producing a fine particle group B containing carbon fibers and a resin and having a particle size distribution of 3 μm or more and 120 μm or less, characterized by using the above “method of producing a plurality of fine particle groups”. And a method for producing the fine particle group B.

Further, the present invention provides a fine particle group A obtained by using the method for producing the fine particle group A described above.
The present invention also provides a fine particle group B obtained by using the method for producing the fine particle group B described above.

  The present invention also provides the fine particle group A as described above, which is used for a filling particle, a fibrous material, a battery negative electrode material, or a dispersed particle for a paint for a film having a thickness of 40 μm or less.

  Further, the present invention relates to the above-mentioned fine particle group B, which is used for filling particles for sheets having a thickness of 2000 μm or less, for dispersed particles for paint, for filling particles for building materials or furniture, or for filling particles for housings of electric appliances. To provide.

According to the present invention, a carbon fiber-reinforced plastic (CFRP) (carbon fiber-containing resin body), which has previously been mainly disposed of by landfill, has been solved by solving the above problems and the above-mentioned problems, and a carbon fiber-containing epoxy resin is particularly preferably used. The resin body can be regenerated as a useful material at a sufficiently low cost.
That is, when a plurality of fine particle groups produced by the production method of the present invention are specialized in the pulverization and classification target to the carbon fiber-containing resin body, the special combination of the pulverization method and the classification method (particularly the classification method) is special. Therefore, it can be suitably used and applied to various uses as "filled particles or dispersed particles" having preferable physical properties and particle size distribution.

In addition, there is no need for a dangerous carbon fiber isolation step, and there is substantially no separation or release of carbon fibers, so there is no problem in safety.
The complete combustion treatment method for disposing of CFRP has a huge energy cost and cannot be reused. Further, a semi-combustion treatment method as a method of separating CFRP into carbon fibers and a matrix resin also requires an energy cost, and the chemical treatment method is a practical method because the matrix resin remains halfway. It has not been converted.
The production method of the present invention is extremely advantageous in terms of energy cost because it is not burned, and since the carbon fiber and the matrix resin are not positively separated in the first place, the danger of the carbon fiber cannot be a problem. In addition, since the carbon fiber and the matrix resin are not separated, it is extremely advantageous in terms of cost.

Further, in the technology of processing from a few hundred microns to a millimeter order or more to form a group of regenerated fine particles, the application of the regenerated product is extremely limited, so that it is not put to practical use, and after all, landfill disposal is better. It was the result of saying.
When the production method of the present invention is used, a fine particle group having a particle size distribution of a part of the “particle size in the range of 1 μm to 120 μm” can be obtained easily and inexpensively while maintaining good physical properties. .
Since the fine particle group obtained by the production method of the present invention has two or more kinds of useful specific particle size distributions, its use is extremely wide. That is, when the obtained respective fine particle groups are dispersed in a new binder resin to form a film, a sheet, a structure, or the like (if reused), the applicable range is extremely wide.

  ADVANTAGE OF THE INVENTION According to this invention, the carbon fiber contained in microparticles does not become too short, and the "characteristics, such as an increase in intensity | strength peculiar to carbon fiber", can be utilized also in a reuse place. For example, unlike the conventional case, there is no such thing that "expensive cloth woven cloth has its use only".

  The present invention is not limited to those having all of the following effects, but specifically, a good particle size distribution and a suitable particle size distribution can be obtained; No cost because there is no need to collect and classify the fine particles at the same time; no exposure and release (desorption) of needle-like carbon fiber; detoxification is achieved; carbon fiber is suitably encapsulated with resin Embedded (coated) (the carbon fiber is still contained as before the pulverization); therefore, in the subsequent use, dispersibility in a liquid dispersion medium (such as a solvent for paint) and solid dispersion medium Excellent dispersibility in (embedding resin, binder resin, etc.); "at least two kinds of fine particle groups (fine particle group A and fine particle group B)" having a particle diameter distribution suitable for each application before that Classify (convert) Can; particulates groups A and / or particulate group B obtained by the present invention, it is possible to adjust the "mass content ratio of the resin to the respective group of fine particles total mass", more applications spread.

FIG. 2 is a schematic view of an apparatus used in the present invention, which is a schematic view illustrating a pulverizing step (1), a particle group B collecting step (2), and a particle group A staying step (3). FIG. 2 is a schematic view of an apparatus used in the present invention, and is a schematic view illustrating an embodiment of a fine particle group A collecting step (4). It is a cross-sectional view of a cyclone part in a cyclone device, and is a schematic diagram showing a positional relationship of an “intake of particle group A” in a circulation device provided in the cyclone device. It is a graph which shows the example of the typical particle size distribution of the broad particle group obtained by performing a grinding process (1). It is a graph which shows the example of the particle size distribution of the fine particle group B obtained by performing the fine particle group B collection process (2). It is a graph which shows the example of the particle size distribution of the fine particle group A obtained by performing the fine particle group A collection process (4). It is a scanning electron microscope (SEM) photograph of a typical broad particle group. 4 is a scanning electron microscope (SEM) photograph of a typical fine particle group B. 5 is a scanning electron microscope (SEM) photograph of a typical fine particle group A.

  Hereinafter, the present invention will be described, but the present invention is not limited to the following specific embodiments, and can be arbitrarily modified within the scope of the technical idea.

  The present invention provides a carbon fiber-containing resin body comprising at least two types of fine particle groups having different particle size distributions, namely, “fine particle group A having a particle size distribution of 1 μm or more and 30 μm or less” and “a particle size distribution of 3 μm or more and 120 μm or less. This is a method for producing a plurality of fine particle groups to be converted into “fine particle group B”.

[Aspect of Fine Particle Group]
Here, the “carbon fiber-containing resin body” refers to a structure in which carbon fibers are dispersed in a matrix resin.
Examples of the resin of the carbon fiber-containing resin body or the plastic of the carbon fiber reinforced plastic (CFRP) as a raw material include, for example, epoxy resin, unsaturated polyester resin, vinyl ester resin, phenol resin, cyanate ester resin, and polyimide resin. Thermosetting resins such as polyamide resins (PA), polycarbonate resins (PC), polyphenylene sulfide resins (PPS), and polyetheretherketone resins (PEEK). Among them, epoxy resins are preferred from the viewpoints of good covering properties, good crushability, wide use of fine particles, being widely used as a plastic for CFRP, and the like.
The present invention provides a carbon fiber-containing epoxy resin body comprising at least two types of fine particle groups having different particle size distributions, "a fine particle group A having a particle size distribution of 1 μm or more and 30 μm or less” and “a particle size distribution of 3 μm or more and 120 μm or less. It is preferable from the above-mentioned reason that the method is a method for producing a plurality of fine particle groups which are converted into a fine particle group B of the present invention.
The “resin” may be a plurality of types. That is, for example, when an epoxy resin is mainly used, another resin may be mixed therein.

The “carbon fiber-containing resin body” as a raw material in the present invention is not limited, but is preferably carbon fiber reinforced plastics (CFRP), which is no longer required, from the viewpoint of cost reduction.
Here, the term "CFRP that is no longer needed" refers to CFRP that is generally used and sold, which is no longer needed, CFRP that is waste, CFRP that has come out as a prototype (including failed products) by manufacturers, etc. Is mentioned. Specific examples include, but are not limited to, golf club shafts; tennis racket frames; fishing rods; automobile frames and various parts; airplane wings and various parts; Parts; musical instruments, cases of portable goods, etc .;

  The “carbon fiber-containing resin body” as a raw material in the present invention is formed by heating a prepreg or the like containing and coexisting carbon fibers in a resin under pressure in an autoclave, or by heating using a microwave or the like. Any of these may be used.

The present invention classifies particles into at least two types of fine particles having different particle size distributions, that is, “fine particle group A having a particle size distribution of 1 μm to 30 μm” and “fine particle group B having a particle size distribution of 3 μm to 120 μm”. This is a method for producing a plurality of fine particle groups.
In the fine particle group A, the particle size distribution is essential to be 1 μm or more and 30 μm or less, preferably 1.3 μm or more and less than 20 μm, particularly preferably 2 μm or more and 15 μm or less.
The particle size distribution of the fine particle group B is essential from 3 μm to 120 μm, but is preferably from 3.3 μm to 90 μm, particularly preferably from 4 μm to 60 μm.

When the particle size distribution is in the above range, it is easy to produce (pulverize and classify) in the following steps (1) to (4), and the obtained fine particle groups are widely used.
Also, in both the fine particle group A and the fine particle group B, when the lower end of the particle size distribution is too small (tailed to the small particle size side), the length of the carbon fiber becomes short, and it becomes difficult to obtain strength or the like. The dispersibility / filling property is reduced; the scattering property is increased, and the operation such as measurement is difficult;
On the other hand, in both the fine particle group A and the fine particle group B, when the upper end of the particle size distribution is too large (when tailing to the large particle size side), the dispersibility / filling property is reduced.

In the present invention, it is essential to produce at least two kinds of fine particles having different particle size distributions, that is, the fine particle group A and the fine particle group B as described above, but other fine particle groups may be manufactured.
Examples of such “other fine particle group” include a fine particle group A ′ having a particle size distribution of 1 μm or more and 5 μm or less, preferably more than 1 μm and less than 5 μm, and particularly preferably 1.5 μm or more and 4 μm or less. . The “fine particle group A” can be conceptually divided into the “fine particle group A” and the “fine particle group A ′” and can be used separately for subsequent applications.

Further, in the present invention, in the steps (2), (3), and (4), the "carbon fiber-containing material" which is sucked and sent to a dust collecting device such as a bag filter from above the cyclone portion without being stopped in the cyclone device. In this case, an ultrafine particle group P having a smaller particle size distribution than the above fine particle group is also obtained. The “ultrafine particle group P” also includes fine particles (group) substantially not containing carbon fibers or containing only a very small amount. In this case, even if the particle diameter is not smaller than that of the fine particle group A or the fine particle group B, it is assumed that they are included in the “ultrafine particle group P” by definition.
The ultrafine particle group P may be discarded or reused. As the recycling method, for example, it can be used to adjust (increase) the “content ratio (R) of resin to the whole fine particles” (described later) of the fine particle group A or the fine particle group B.

The average particle size of the fine particle group A obtained in the present invention is preferably 2 μm or more and 20 μm or less, more preferably 2.5 μm or more and 15 μm or less, and particularly preferably 3 μm or more and 10 μm or less.
The average particle size of the fine particle group B obtained in the present invention is preferably 4 μm or more and 60 μm or less, more preferably 7 μm or more and 50 μm or less, and particularly preferably 10 μm or more and 40 μm or less.
When the average particle size is in the above range, it is easy to produce (pulverize / classify) in the following steps (1) to (4), and the obtained fine particle groups are widely used. When the above range is deviated from the upper side or the lower side, the same thing as described in the place of the particle size distribution may occur.

In the present invention, the “particle size distribution” refers to a range (μm) in which 80% by mass (vol%) or more of the fine particles fall, not a range (μm) in which 100% by mass (vol%) of the fine particles falls.
The particle size distribution and the average particle size in the present invention are defined as those measured by a wet method using a laser diffraction / scattering type particle size distribution measuring device Microtrack manufactured by Nikkiso Co., Ltd. and measured by the measuring device (method). You.
The vertical axis of the particle size distribution in the present invention is mass (volume), and the “average particle size” refers to the volume (mass) average particle size measured by the above apparatus.

[Production method]
The production method of the present invention is characterized by including all of the above-mentioned steps (1) to (4).

<Crushing process>
In the “method of producing a plurality of fine particle groups” of the present invention, it is preferable to include a crushing step of crushing the carbon fiber-containing resin body D before the following crushing step (1). In other words, before the carbon fiber-containing resin body D is charged into the airflow pulverizer 11, the carbon fiber-containing resin body D is crushed to a range allowable as a size to be charged into the airflow pulverizer 11, thereby obtaining “crushed carbon fiber-containing resin body E”. Preferably.
The apparatus used for the crushing is not particularly limited, and examples thereof include a cutter mill, a crusher mill, a hammer mill, and an axial flow mill.

The crushing size of the crushed material E depends on the airflow crusher 11 to be used, but as the maximum crossing length of the crushing object, a size in the range of 0.2 cm to 5 cm is preferable, and a size in the range of 0.5 cm to 3 cm is preferable. Particularly preferred.
If the input size to the airflow crusher 11 is too large, the airflow crusher 11 may not be crushed. On the other hand, if the input size to the airflow crusher 11 is too small, there is no need to reduce the size. In which the disadvantages of the above-mentioned "pulverizers other than the airflow pulverizer"occur; in particular, the case where the carbon fiber and the resin are separated.

  The “crushed product E of the carbon fiber-containing resin body” obtained in the crushing step is put into an airflow crusher using the hopper 12 or the like, and the next crushing step (1) is performed.

<Pulverizing process (1)>
In the step (1), “the airflow crusher 11 that has two or more impellers 14 and crushes the particles to be crushed by the swirling airflow generated by the rotation of the impellers 14 and crushes the particles”. Is a pulverization step of obtaining a broad particle group F having a particle size distribution of 1 μm or more and 120 μm or less.
Here, the "air flow pulverizer" refers to a device that generates an air flow by rotating an impeller (rotary wing) and pulverizes an object put in the air flow in a dry manner to produce fine particles.

It is essential to obtain a broad particle group F having a particle size distribution of 1 μm or more and 120 μm or less by pulverizing with an air current pulverizer 11, but preferably 1.3 μm or more and 90 μm or less, particularly preferably 2 μm or more and 60 μm or less. A broad particle group F having a diameter distribution is obtained.
Within this range, the particles are easily crushed by the airflow crusher 11, the carbon fibers are not exposed or released (separated), and the fine particle groups A and B obtained in the following steps (2), (3) and (4) Has the effect described above. Further, if the lower end of the particle size distribution of the broad particle group F before classification is too small or the upper end is too large, the same phenomenon as described in the above-mentioned “particle size distribution” may occur.

  When pulverized by the airflow pulverizer 11, it is easy to pulverize in the range of the particle size distribution described above; the carbon fibers are not exposed on the surface of the pulverized fine particles and / or the carbon fibers are not released from the fine particles (group); The temperature rise of the object is suppressed because the particles are crushed by collision; the particles are crushed mainly by the collision between particles, so that the particles are crushed into a form that easily exerts the above-mentioned effect; Since the particles are crushed by collision, the obtained fine particles (group) have an effect of very little metal contamination.

  Further, as a further application, when the obtained fine particle group A and / or B is dispersed in a binder resin to produce a film, a sheet, a structure, or the like, the fine particle (group) is excellent in dispersibility, In addition, aggregation is suppressed; with respect to films, sheets, structures, etc., excellent surface color unevenness prevention (color uniformity); excellent in conductivity, antistatic properties, jet-blackness, anticorrosion properties, extrusion molding suitability, etc .; Cracks do not occur even when the film is bent; the bleeding of carbon fibers on the surface is suppressed, and it is difficult to contaminate articles, limbs, clothes, etc., which are in contact with the surface with black.

  For example, when a crusher mill, a pin mill, a cutter mill, a hammer mill, an axial flow mill, or the like is used, it is difficult to sufficiently reduce the average particle diameter while suppressing costs (for example, it is difficult to pulverize until the particle diameter becomes 120 μm or less to 90 μm or less). Difficult), the particles obtained by pulverizing with these pulverizers were obtained because the average particle size was too large or the particle size distribution was too wide and the maximum particle size was too large (fine). The use of the particles is limited, that is, there is almost no use of the structure obtained by dispersing the obtained (fine) particles in the binder resin, or the range of use of the structure is limited.

  For example, as described above, a crusher such as a rotary collision type that collides with a rotating body, a roll type, a medium type, a millstone type, a cutter type, etc., applies mechanical stress such as impact, compression, friction, and shear to a crushed object. If it is difficult to sufficiently reduce the (average) particle size due to excessive addition, and the obtained "fine particle group" cannot achieve the above-mentioned "effect when using the airflow pulverizer". There is.

  On the other hand, a jet mill or the like, which crushes an object by colliding the object with a collision plate, can reduce the average particle size to a sufficiently small value, but the needle-like carbon fibers are exposed or separated, and the crushing operator and the obtained fine particle group are separated. Is extremely dangerous for some users. Further, there is a case where the pulverization processing efficiency (speed) is too low to increase the cost.

The airflow pulverizer 11 is used for pulverizing foodstuffs / feedstuffs containing components such as starch and protein that are easily degraded by heat, components that easily emit fragrance by heat, and components that easily adhere to the inside of the pulverizer by heat. Are particularly preferably used.
In the pulverizing step (1) of the present invention, the airflow pulverizer used for pulverizing foodstuffs, feeds, etc. is used to obtain the particle size distribution, average particle size, pulverization efficiency (speed), pulverization target of the obtained fine particles. It is particularly preferable in terms of suppressing the temperature rise of the object.

  Further, as the airflow crusher 11, a commercially available device can be suitably used. Commercial products include, for example, a cyclone mill manufactured by Shizuoka Plant Co., Ltd., a cyclone mill manufactured by Shizuoka Machinery Co., Ltd., a super powder mill manufactured by Nishimura Machinery Co., Ltd., a tornado mill manufactured by Sanjo Industry Co., Ltd., and Furukawa Soki Dream Mill manufactured by Systems Co., Ltd., and the like.

The structure of the airflow pulverizer 11 is not particularly limited, but has one or two or more impellers 14, and mainly includes particles to be pulverized by a swirling airflow generated when the impeller 14 is rotated by the motor 13. It is preferable that the particles are made to collide with each other to form fine particles from the viewpoint of easily obtaining the effect obtained by using the airflow crusher 11 and the like.
In particular, specifically, the temperature rise of the object to be crushed is suppressed; the separation of “carbon fiber” and “matrix resin” in the carbon fiber-containing resin body to be crushed is suppressed (the release of carbon fiber is suppressed). It is preferable from the viewpoints that the carbon fibers are not exposed to the surface of the fine particles, and that metal contamination caused by the materials used for the impeller 14, the blade, and the like is extremely small.
By using the airflow pulverizer 11, the carbon fibers covered with the resin can be obtained by suppressing the separation of the carbon fibers and the resin or by suppressing the carbon fibers from being exposed to the surface of the fine particles. The above-mentioned effects such as good filling properties and good dispersibility are exhibited, and the quality is stabilized. In addition, since the release of carbon fibers is suppressed, it is safe for workers, users, and the like.

  The number of impellers is preferably two or more from the viewpoint of crushing efficiency, and the two impellers may be rotated in the same direction or in opposite directions.

  Although not particularly limited, the airflow pulverizer 11 has a classifying function inside, and the classified coarse particles are pulverized again inside the airflow pulverizer 11, and the classified fine particles are mixed with the broad particle group F. Is transferred to the cyclone site 23 through the transfer pipe 22 from the viewpoint of removing coarse particles, giving a suitable particle size distribution to the broad particle group F provided in the step (2) and subsequent steps, and the like. Particularly preferred.

The upper limit of the temperature of the object to be pulverized (the carbon fiber-containing resin body, the pulverized product during the pulverization, and the broad particles (group)) is preferably maintained at 70 ° C. or lower, more preferably 60 ° C. or lower, and more preferably 50 ° C. or lower. Is more preferable, and 40 ° C. or lower is particularly preferable. If the temperature is too high, the effect of using the airflow crusher 11 may not be obtained.
The lower limit of the temperature is not particularly limited, and is preferably room temperature at the time of pulverization. That is, 0 ° C. or higher is preferable, and 10 ° C. or higher is particularly preferable.

The rotation speed of the impeller 14 depends on the diameter of the impeller 14, but when an impeller having a diameter of 150 mm to 600 mm is used, it is preferably 3000 rpm or more and 15000 rpm or less, more preferably 4000 rpm or more and 12000 rpm or less, and particularly preferably 5000 rpm or more and 10000 rpm or less. preferable. When the diameter is out of the above range, the extension thereof determines (particularly) a preferable range.
The peripheral speed of the impeller 14 hardly depends on the diameter of the impeller, and is preferably from 60 m / s to 300 m / s, more preferably from 80 m / s to 260 m / s, and particularly preferably from 100 m / s to 220 m / s.

  In addition, a continuous feeding (feed) method or a batch (batch) method may be used. In the case of the continuous feeding (feed) method, the feeding speed (feed speed) of the carbon fiber-containing resin body to be pulverized is determined by an airflow pulverizer. 0.5 [(kg / min) / L] or more and 3 [(kg / min) / L] or less, preferably 1 [(kg / min) / L] or more and 2.5 [( kg / min) / L] or less, more preferably 1.5 [(kg / min) / L] or more and 2 [(kg / min) / L].

When the rotation speed and the peripheral speed of the impeller 14 are too slow, or when the charging speed is too fast, there are cases where the pulverization cannot be performed sufficiently, particularly when the particle size cannot be reduced to 120 μm or less.
On the other hand, when the rotation speed and the peripheral speed of the impeller 14 are too high, or when the charging speed is too low, the production (crushing) efficiency is too low, the operation cost is too high, and the time and cost are wasted. There are cases.

The distance between the two impellers 14 is preferably 15 mm or more and 60 mm or less, more preferably 18 mm or more and 50 mm or less, and particularly preferably 20 mm or more and 40 mm or less.
Within the above range, a good swirling airflow can be easily generated in the apparatus, and efficient pulverization is possible.

FIG. 7 shows an SEM photograph of the broad fine particles (group) obtained as described above. From a perfect fibrous or needle-like shape, it is rounded by the impact at the time of pulverization using the airflow pulverizer 11. FIG. 8 shows the shape of a typical fine particle (group) B, and FIG. 9 shows the shape of a typical fine particle (group) A.
During pulverization by the airflow pulverizer 11, the resin in the carbon fiber-containing resin body extends on the surface of the carbon fiber so as to coat the surface of the carbon fiber, and embeds and covers the carbon fiber. Retained without separation from carbon fiber. Therefore, the effects of the present invention described above are exhibited.

  In the pulverizing step (1), by increasing (decreasing) the rotation speed or the peripheral speed of the impeller 14 and / or increasing (narrowing) the impeller interval of the two or more impellers 14, the “broad” is achieved. It is possible to decrease (increase) the “content ratio (R) of the resin with respect to the whole fine particles” of the fine particles belonging to the fine particle group F, the fine particle group A or the fine particle group B. Here, all three parentheses () are in the same order.

That is, the “content ratio (R) of carbon fiber and resin” of the fine particle groups A and B can be adjusted by the impeller 14. It has been found for the first time by the present invention that the “resin content ratio (R)” of the obtained fine particles (group) is changed (adjustable) by the above-described adjustment of the impeller 14 of the airflow crusher 11.
The optimum ratio between the carbon fiber and the resin is different depending on the use of the fine particle group of the present invention. However, by adjusting the impeller as described above, the “resin content ratio (R) with respect to the whole fine particles” is adjusted, and Can be suitably produced.

<Particle Group B Collection Step (2)>
In the step (2), the “cyclone device 21 including the transfer pipe 22, the cyclone part 23, the dampers 24 and 25, and the final recovery container 26 in this order from the airflow crusher 11” is sucked. By operating the cyclone device 21 while transferring the broad particle group F obtained in the pulverizing step (1) into the cyclone part 23, the fine particles belonging to the fine particle group B are collected in the final collection container 26. This is a particle group B collecting step.

  As shown in FIGS. 1 and 2, the transfer pipe 22 is a pipe for transferring the broad particle group F pulverized by the airflow pulverizer 11 to the cyclone device 21. It is connected to the upper part of the part 23. A “particle group A circulation pipe 35 of the circulation device 31” described later is connected to the transfer pipe 22 on the way, and the particle group A merges with the broad particle group F immediately after pulverization at the outlet 34 to form a cyclone. It returns to the upper part of the part 23. It is also preferable to increase the collection speed by arranging a plurality of cyclone devices 21 in parallel.

The cyclone device 21 is operated, and the cyclone device 21 is sucked by the suction S. As schematically shown in FIGS. 1 and 2, in the cyclone portion 23, heavy particles such as the above-described fine particle group B are pressed against the outer periphery (near) of the cyclone by centrifugal force by the cyclone mechanism, and the cyclone portion 23 is formed. It falls while rotating (circulating) along the outer circumference toward the lower part of.
On the other hand, the light particles such as the fine particle group A and the ultra fine particle group P move downward near the center axis 27 of the cyclone portion 23 after falling down the cyclone portion 23. Among the fine particles that have moved to the upper part, the above-mentioned ultra fine particles pass through the cyclone part 23 upward as they are and are collected by the ultra fine particle collection device 41 having the dust collector 42.

  In the fine particle group B collecting step (2), the damper located below the cyclone portion 23 is opened as an open damper 24, and the fine particles that have fallen around the cyclone portion 23 during (full) operation (suction S). The group B is collected in the final collection container 26.

  The size of the cyclone portion is not particularly limited, but the diameter of the central portion of the height of the cyclone portion is preferably 50 mm or more and 700 mm or less, more preferably 70 mm or more and 300 mm or less, and particularly preferably 100 mm or more and 200 mm or less. The height of the cyclone portion is preferably from 100 mm to 1600 mm, more preferably from 130 mm to 700 mm, and particularly preferably from 200 mm to 400 mm. The volume of the cyclone site is preferably from 0.03 L to 600 L, more preferably from 0.3 L to 100 L, and particularly preferably from 1.5 L to 15 L. If the size is too small, the feeding (feed) speed to be described later may decrease and productivity may decrease. If the size is too large, the fine particle group A and the fine particle group B may not be suitably divided.

  The supply (feed) speed of the broad fine particle group to the cyclone device 21 (because it is preferable that the steps (1) and (2) are continuous), the feed rate of the raw material in the above-mentioned pulverization step (1) ( Feed speed). Further, since the size and the suction force (suction capacity) of the cyclone portion 23 provided in the cyclone device 21 are almost constant, it is preferably from 2.5 kg / min to 20 kg / min, and preferably from 4 kg / min to 13 kg / min. Is more preferable, and 8 kg / min or more and 10 kg / min or less are particularly preferable.

  Since the particle size distribution of the broad particle group F supplied to the cyclone device 21 is 1 μm or more and 120 μm or less as described above, the particle size distribution of the fine particle group B that falls down the cyclone portion 23 and is collected in the final collection container 26 Can be 3 μm or more and 120 μm or less. If the airflow pulverizer 11 has a classifying function and the upper limit of the particle size is set to, for example, 70 μm, the upper limit of the particle size distribution of the broad particle group F and the fine particle group B can be set to, for example, 70 μm.

<Ultra-fine particle collection process>
The present invention further has a bag filter in the middle of sucking the cyclone device 21, and the ultrafine particles P having a particle diameter of 1 μm or less (the particle diameter is preferably larger than 1 μm when no carbon fiber is contained). It is preferable to have an ultrafine particle group collecting step of collecting (a).
Among the fine particles that have moved to the upper part of the cyclone part 23 during the (full) operation, the ultrafine particles that have penetrated the cyclone part 23 upward as they are are collected in the ultrafine particle collection device 41 provided with the dust collector 42. The ultrafine particles may be discarded or reused.

<Particle group A staying process (3)>
In the step (3), the cyclone apparatus 21 further includes an inlet 33 between the outer peripheral inner wall of the cyclone portion 23 and the central shaft 27 and is connected as an outlet 34 in the transfer pipe 22. A circulation device 31 ", and allows the fine particles belonging to the fine particle group A to stay in the cyclone portion 23 and the circulation device 31 during the operation of the cyclone device 21 without entering the final collection container 26. This is the particle group A staying step.
Usually, the step (3) is performed simultaneously with the step (2) in terms of time.

  As shown in FIGS. 1, 2 and 3, the cyclone device 21 used in the present invention has “an intake port 33 between the outer peripheral inner wall of the cyclone portion 23 and the central shaft 27, A circulating device 31 "which is connected as an outlet 34. FIG. 3 shows the positional relationship between the central axis 27 of the cyclone portion 23, the inner peripheral wall, and the intake port 33.

  During operation of the cyclone device (full), suction is performed by the blower 32 provided in the circulating device 31, the fine particle group A is taken in from the intake port 33 of the circulating device 31, and an outlet 34 provided in the middle of the transfer pipe 22. Is discharged into the transfer pipe 22 to be combined with the just-crushed broad fine particles.

During operation of the cyclone device (full), the fine particles belonging to the fine particle group B are collected in the final collection container 26 below the cyclone part 23 as described above, while the fine particles belonging to the fine particle group A are light (full). ) During the operation, the cyclone device 31 is circulated in the circulation device 31. In step (4) described later, when the suction S (operation) of the cyclone device 21 is weakened or stopped, the cyclone device 21 falls outside the cyclone portion for the first time.
That is, since the particle group A has a particle size distribution of 1 μm or more and 30 μm or less and is lighter than the particle group B having a particle size distribution of 3 μm or more and 120 μm or less, the particle group A falls in the cyclone portion in the step (2). Thereafter, it is hard to be collected in the final collection container 26 thereunder, and rises again near the central axis 27 of the cyclone portion 23 (see FIG. 1).

  The circulation device 31 guides the rising fine particles belonging to the fine particle group A to the transfer pipe 22 again by the blower 32, combines the fine particles with the broad particle group F, and re-inputs the fine particles to the cyclone device 21, whereby the cyclone device ( During the (full) operation, the fine particle group A is always circulated in the cyclone apparatus and stays there. The “hatched portion (hatched portion) in the transfer pipe 22 and the blower 32” in FIG. 1 indicates a place where the particle group A circulates and stays in the circulating device 31.

On the other hand, the ultrafine particle group P penetrates upward through the cyclone portion 23 during operation of the cyclone device without being sucked from the intake port 33 of the circulation device 31 (without being taken into the circulation device 31), and the dust collector 42 To the ultra-fine particle collection device 41 provided with
That is, in the steps (2) and (3), during the operation of the cyclone device (full), the particle group B is collected in the final collection container 26, and the ultra particle group P penetrates upward through the cyclone part 23 and the ultra particle collection device 41 And the fine particle group A having a particle size distribution intermediate between them is circulating in the circulating device 31.

As shown in FIG. 3, the intake 33 of the circulation device 31 is located between the inner peripheral wall of the cyclone part 23 and the central axis 27. The position of the inlet 33 is not particularly limited as long as the fine particle group A can be efficiently circulated, but is preferably 1/10 or more and 2/3 or less of the radius R from the central axis side to the outer peripheral inner wall from the central axis side. , 以上 or more and 以下 or less, more preferably １ ／ or more and ３ or less.
If the intake 33 is too close to the central axis 27 (if the above value is small), the “ultrafine particles that want to penetrate upward near the central axis of the cyclone portion 23 and go to the ultrafine particle collection device 41” (It may contain fine particles having a particle size of 1 μm or more which is not contained in some cases.) May be taken into the circulation device 31 and mixed into the fine particle group A.
On the other hand, when the inlet 33 is too far from the central axis 27 and approaches the outer periphery (when the above value is large), the “particles that should be circulated as the particle group A in the step (3) and collected for the first time in the step (4)” In the case where “A” penetrates upward through the cyclone site 23 and exits toward the ultra-fine particle collecting device 41, or conversely, “the fine particle group B to be collected in the step (2)” is taken into the circulation device 31. In some cases, it is mixed with the fine particle group A.

The “position of the cyclone portion 23 in the vertical direction” of the intake 33 of the circulation device 31 is 以上 or more from the bottom of the entire “height of only the inclined portion of the cyclone portion 23” ( It is preferably 10/10 (the uppermost meaning) from the 1/2 position, more preferably 3/5 or more and 9/10 or less, particularly preferably 2/3 or more and 7/8 or less.
If the intake port 33 is too low (the value is too small), the diameter of the cyclone portion 23 is too small, so that the fine particle group B, the fine particle group A, and the ultrafine particle group P may not be clearly separated. On the other hand, even if the intake 33 is too high (even if the above value is too large), there is a case similar to the above.

<Particle Group A Collection Step (4)>
In the step (4), the damper is closed, the operation of the circulation device 31 is weakened or stopped, and the suction S of the cyclone device 21 is weakened or stopped, and the fine particle group A is dropped. This is a step of collecting the fine particle group A to be collected.

  When approaching the end of the (full) operation of the cyclone device 21, the damper located below the cyclone portion 23 is closed to form a closed damper 25, the suction S of the cyclone device 21 is weakened or stopped, and the blower 32 of the circulation device 31 is closed. By weakening or stopping, the operation of the circulation device 31 is weakened or stopped. Here, it is preferable that the above-mentioned “weak” or “stop” is gradually weakened, especially for the suction S, and finally stopped. Until the blower 32 is stopped, the suction S is performed at a suction force of preferably 10% or more and 40% or less at full operation, particularly preferably 15% or more and 25% or less, and gradually stopped finally. preferable.

  After the damper is closed, the fine particle group B collected in the final collection container 26 is taken out or stored together with the final collection container 26.

  Thereafter, the above operation is performed to collect the fine particle group A. After collecting the fine particle group B in the final collection container, an empty container (which may be the same as or different from the final collection container 26) for collecting the fine particles A is installed, and the empty container is collected on the closed damper 25. The fine particle group A may be collected, or the fine particle group A may be directly dropped into the container and collected without being temporarily stored on the closed damper 25.

[Method for Producing Fine Particle Group A and Fine Particle Group B]
The present invention is a method for producing a fine particle group A containing carbon fibers and a resin and having a particle size distribution of 1 μm or more and 30 μm or less, characterized by using the aforementioned “method of producing a plurality of fine particle groups”. This is also a method for producing the fine particle group A.
Further, the present invention is a method for producing a fine particle group B containing carbon fibers and a resin and having a particle size distribution of 3 μm or more and 120 μm or less, characterized by using the above “method of producing a plurality of fine particle groups”. Is a method for producing the fine particle group B.
Needless to say, if a plurality of fine particle groups can be manufactured, individual fine particle groups can be manufactured.

[Particle Group A and Particle Group B]
The present invention is also a fine particle group A obtained by using the method for producing the fine particle group A, and is obtained by using the method for producing the fine particle group B. It is also a fine particle group B characterized by the following.

As described above, when the carbon fiber-containing resin body is pulverized by the airflow pulverizer 11, the pulverization targets collide with each other to produce fine particles having a rounded surface. In addition, there are few carbon fibers exposed on the surface, and there is no mixing of metal elements derived from the pulverizer. In addition, since the temperature rise during pulverization is small, it is considered that the fine particles are unique.
However, it is impossible to directly specify the shape of such fine particles with parameters or the like, and it is not possible to directly specify the form of the carbon fiber exposed on the surface or to quantify the trace amount of contained metal. Impossible or almost impractical.

Further, the classification step in the present invention has a great feature that no cost is required, and the fine particle group A and the fine particle group B produced in the steps (2), (3) and (4) have a particle size distribution. Is optimal for various applications and is not necessarily too sharp.
Further, the “content ratio (R) of the resin with respect to the whole fine particles” usually changes from that of the carbon fiber-containing resin body D used as a raw material. Usually different.
However, it is impossible or almost impractical to directly specify the particle size distribution of such a fine particle group or the component composition of the fine particles.

[Use]
The fine particle group A and the fine particle group B of the present invention are useful as an anti-slip member, an antistatic member, a visible light blocking member, an ultraviolet blocking member, a strength reinforcing member, a flame retardancy imparting member, a coloring member, a waterproof member, and the like.
Further, since the fine particle group A and the fine particle group B of the present invention have many excellent physical properties derived from carbon fibers, the carbon fibers themselves are filled in already used products (applications) and reused. can do.

The fine particle group A and the fine particle group B of the present invention can be formed into a film, a sheet or a structure by adding a binder resin to the resin derived from the raw material (matrix resin of the raw material) contained therein. .
Such binder resins are not particularly limited, but include hard polyvinyl chloride, soft polyvinyl chloride, thermoplastic polyurethane, polyamide, polyester, polycarbonate, ethylene vinyl acetate copolymer (EVA), polyethylene, polypropylene, poly (meth) acrylate, and polystyrene. And thermoplastic resins such as copolymers thereof; and thermosetting resins such as resins, unsaturated polyesters, phenolic resins, and polyimides.

  Since the particle group A of the present invention has a particle size distribution of 1 μm or more and 30 μm or less, it is preferably used as a filler particle for a film having a film thickness of 40 μm or less, for a fiber material, for a battery negative electrode material, or as a dispersed particle for a paint. Can be used. The thickness of the film is more preferably 1 μm or more and 35 μm or less, and particularly preferably 1.5 μm or more and 30 μm or less.

Specifically, it is preferably used as a filler particle in a film such as an electromagnetic wave shielding film, an electronic substrate shielding cover film, a conductive film, a metal oxidation preventing film, an agricultural multi-film, a transparent member smoke film, and an antistatic film. Can be used.
Further, it can be suitably used as a material for fibers such as an agricultural non-woven fabric, a speaker non-woven fabric and an insect net.
Further, it can be suitably used as a battery negative electrode material instead of graphite. Further, it can be suitably used as a dispersed particle for paints such as conductive paints, antistatic paints and antioxidant paints.

  Among the fine particle group A, the fine particle group A having a large particle size of 5 μm or less (distributed on the small particle size side) or the fine particle group A ′ having a particle size distribution of 1 μm or more and 5 μm or less is particularly an electromagnetic wave shield. It can be suitably used as a filling particle in a film such as a film, an electronic substrate shielding cover film, a conductive film, and a film for preventing metal oxidation.

Since the fine particle group B of the present invention has a particle size distribution of 3 μm or more and 120 μm or less, for a filling particle for a sheet having a thickness of 2000 μm or less, for a dispersed particle for a paint, for a filling particle for a building material or furniture, or for an electric product. It can be suitably used for filling particles for a housing.
The thickness of the sheet is more preferably 3 μm or more and 1000 μm or less, further preferably 4 μm or more and 300 μm or less, and particularly preferably 5 μm or more and 120 μm or less.

  Specifically, it can be suitably used as a filler particle for sheets such as a conductive sheet, a heat conductive sheet, a snow melting sheet, a ground heating sheet (such as a livestock hut), an anti-slip sheet, and an anti-static sheet. In addition, it can be suitably used as a dispersed particle for paints such as rust preventive paints, anticorrosive paints, and heat resistant paints. Further, it can be suitably used as a reinforcing material such as a fortified composite material (casting press method), a reinforcing material such as a lightweight and reinforced plate (by extrusion molding), and a rail for furniture. Further, it can be suitably used as a filling particle for a housing of an electric product such as a housing of a home appliance.

  In addition, those generally used as carbon fiber reinforced plastic (CFRP) are also suitably used as filler particles. As such, specifically, (a part of) sports equipment such as, for example, golf club shafts, tennis racket frames, fishing rods; various parts of vehicles such as automobiles, bicycles, airplanes, and ships; Musical instruments, portable goods, and fragile cases; and the like.

  In the above-mentioned films, sheets, structures and the like, in addition to the fine particles of the present invention and the binder resin, a plasticizer for the binder resin, a dispersant for the fine particles, a heat stabilizer, a foaming agent, a coloring agent, a lubricant, Materials, antistatic agents, other inorganic or organic fillers, flame retardants / flame retardants, surfactants, release agents, thickening stabilizers, and the like. Each of these may be used alone or in combination of two or more.

The method for producing the film, sheet, structure, and the like described above is not particularly limited, and may be determined based on the structure and physical properties of the binder resin, and a known method may be used. It is also preferable to prepare a sol compound containing a binder resin, a plasticizer, a dispersant, and the like in advance at the stage before the addition, and blend the fine particles A or B of the present invention therein. It is also preferable to mix some of the above components in advance and then mix and mix the other components. It is also preferable to dissolve and disperse in a solvent / dispersant before mixing.
For preparation and mixing, a known device such as a stirrer can be used, and the device is not limited, but can be produced by a known method. For example, it is produced by solventless molding; distilling and drying the solvent or dispersant after coating with a solvent or dispersant; removing after pouring into a mold; spraying; Furthermore, you may bake after forming and forming a coating film.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples as long as the gist of the present invention is not exceeded.

Example 1
<Crushing process>
From the carbon fiber reinforced plastic (CFRP) which has been a waste material, 5 kg of the carbon fiber-containing epoxy resin body is about 0.7 cm to about 2 cm by using a cutter mill (manufactured by Makino Sangyo Co., Ltd., small low-speed crusher GSL). Crushed to a corner.
Here, the carbon fiber-containing epoxy resin body used as a raw material is obtained by forming a carbon fiber into a plate-like layer, infiltrating a thermosetting epoxy resin as a matrix resin therein, and thermosetting under pressure. And 85 parts by mass of carbon fiber and 15 parts by mass of a thermosetting epoxy resin.

<Pulverizing process (1)>
Next, the obtained “crushed product containing 85 parts by mass of carbon fiber and 15 parts by mass of the thermosetting resin” is put into a crusher using the hopper 12 or the like. As a pulverizer, an air current pulverizer (Cyclone Mill 400S, manufactured by Shizuoka Plant Co., Ltd.) is used, and pulverization is performed at room temperature (25 ° C.) under standard conditions of the air current pulverizer. Obtained.

The airflow pulverizer 11 has two impellers 14 having a diameter of 150 mm inside the apparatus. Large particles are coarsely pulverized by the first impeller and moved to the second impeller side. 1. In the (high-speed) swirling airflow around the second impeller, they collide with each other and are pulverized. That is, the particles to be pulverized are mainly collided with each other by the swirling airflow and pulverized.
Further, the airflow crusher 11 has a classification function inside the apparatus, and the classified coarse powder is crushed again inside, and the classified fine powder can be taken out, that is, the classification is performed by centrifugal force. The fine powder thus obtained was taken out by the airflow of the blower.

At the time of pulverization, the distance between the two impellers of the airflow pulverizer was set to 30 mm, the rotation speed of the impeller was 8000 rpm, and the peripheral speed at that time was 170 m / s.
The collision between the particles to be pulverized and the impeller 14 is small, and since the particles are mainly pulverized by collision between the particles and cooled by a large amount of airflow, the temperature rise of the particles during the pulverization is suppressed. I couldn't see it.

FIG. 4A shows the particle size distribution of the obtained broad fine particle group. The particle size distribution of the obtained broad fine particle group (range in which 80% is included) was 1 μm or more and 120 μm or less. The broad particle group F had a volume average particle size of 40 μm. FIG. 4B shows the particle size distribution of the broad fine particle group similarly obtained by using another CFRP than in Example 1.
The particle size distribution and the average particle size in the present invention are defined as those measured by a wet method using a laser diffraction / scattering type particle size distribution measuring device Microtrack manufactured by Nikkiso Co., Ltd. and measured by the measuring device (method). You. All are distributions or average particle diameters based on volume (mass).

The carbon fibers of the carbon fiber-containing epoxy resin body as the raw material were not exposed on the surface of the obtained fine particles, and the carbon fibers were covered with the epoxy resin (FIGS. 7 to 9).
Further, from the beginning to the end of the pulverization, the fibrous carbon fibers were not separated and taken out (discharged) from the airflow pulverizer 11.

<Particle Group B Collection Step (2)>
Using the “cyclone device 21 having the circulation device 31” as schematically shown in FIG. 1, the fine particle group B (fine particles belonging to the fine particle group) was collected in the final collection container 26 from the broad particle group F obtained above. .

The cyclone device 21 was equipped with the transfer pipe 22, the cyclone part 23, the closed damper 25, and the final recovery container 26 in this order from the side of the airflow crusher 11.
Further, the cyclone device 21 had a circulation device 31 having an intake 33 (for the particle group A) in the middle of the cyclone portion 23 (see FIGS. 1 and 3). The diameter at the midpoint of the height of the cyclone site was 150 mm, the height was 300 mm, and the volume was 5.3 L.

The broad particle group F obtained in the pulverizing step (1) was supplied to the cyclone device 21 at a rate of 3 kg / min. The pulverizing speed was adjusted to such a speed, and the broad particle group was transferred from the airflow pulverizer 11 in the step (1) to the cyclone device 21 in the step (2) by the transfer pipe 22.
The particle group A was kept in the circulation device 31, while the particle group B was collected in the final collection container 26.

FIG. 5A shows the particle size distribution of the obtained fine particle group B. The particle size distribution of the fine particle group B (the range where 80% is included) was 3 μm or more and 60 μm or less. FIGS. 5B and 5C show the particle size distributions of broad fine particles obtained in the same manner using CFRP different from that in Example 1.
FIG. 8 shows a scanning electron microscope (SEM) photograph of the fine particle group B.

<Particle group A staying process (3)>
The particle group A staying step (3) was performed in parallel with the particle group B collection step (2).
The cyclone device 21 had "a circulating device 31 having, for example, an intake port 33 at a position as shown in FIG. 3 and being connected in the middle of the transfer pipe 22". The vertical position of the intake 33 was 2/3 from the bottom of the cyclone site.

  The cyclone device 21 was operated by performing the suction S of the cyclone device, and the particle group B was collected in the final collection container 26. At the same time, the particle group A was kept in the cyclone part 23 and the circulation device 31. That is, the fine particles A were sucked by the blower 32, returned to the transfer pipe 22 from the circulation inlet 33, combined with the broad fine particles from the airflow crusher 11, and then re-entered into the cyclone portion 23.

<Particle Group A Collection Step (4)>
When the cyclone device 21 is fully operated for 60 minutes continuously and the particle group A is considered to be staying in the circulating device 31 and the cyclone portion 23 of about 50 kg, the damper is closed. Then, the output of the suction S of the cyclone device 21 was reduced to 20% of the full operation, and the suction of the blower 32 of the circulation device 31 was stopped.

The collected fine particle group B was stored in the final collection container 26, and a container for collecting the fine particle group A was set in the same place.
The damper was changed to the open damper 24, and the fine particle group A accumulated on the damper and the fine particle group A existing in the cyclone device 21 including the circulation device 31 were collected in the container.

FIG. 6 shows the particle size distribution of the obtained fine particle group A. The particle size distribution of the fine particle group A was 1 μm or more and 30 μm or less.
FIG. 9 shows a scanning electron microscope (SEM) photograph of the fine particle group A.

  The ultrafine particle group P that could not be collected by the cyclone device 21 was collected in an ultrafine particle group collection step using a bag filter. The particle size distribution of the ultrafine particle group P was 1 μm or less, or contained substantially no carbon fiber.

At this time, 10 kg of the fine particle group B, 50 kg of the fine particle group A, and 0.5 kg of the ultra fine particle group were obtained.
It was found that particles having different particle size distributions (fine particle group A and fine particle group B) can be produced depending on the use of the fine particle group.

<Repeat of steps (1) to (4)>
In order to avoid staying (circulating) a large amount of the particle group A in the apparatus, in order to collect the particle group A in the final collection container 26 in each case, the steps (1) to (3) are divided into three batches. (4) was performed. That is, the above steps were repeated three times to obtain the fine particle group B, the fine particle group A, and the ultrafine particle group P each having a total of 2.7 times the mass described above.

Example 2
In Example 1, the supply speed of the carbon fiber-containing resin body, the impeller interval, and the rotation speed in the pulverizing step (1) were adjusted to obtain a group of broad fine particles having a particle size distribution of 2 μm or more and 90 μm or less.
Steps (2), (3) and (4) were performed in the same manner as in Example 1 to produce a fine particle group A having a particle size distribution of 2 μm to 20 μm and a fine particle group B having a particle size distribution of 3 μm to 90 μm.

Example 3
Using carbon fiber-containing epoxy resin body containing 85% by mass of carbon fiber and 15% by mass of epoxy resin, which is a recycled carbon fiber reinforced plastic (CFRP), using the apparatus shown in FIGS. Except for the above, a fine particle group was produced in the same manner as in Example 1.
That is, in the pulverizing step (1), the conditions relating to the impeller 14 were varied in the following three stages to produce a group of broad particles, and then a group of particles A and a group of particles B were produced in the same manner as in Example 1.

<< Condition 1 >>
Rotation speed: 10000 rpm
Peripheral speed: 209 [m / s]
Impeller gap: 40mm
<< Condition 2 >>
Rotation speed: 8000 rpm
Peripheral speed: 168 [m / s]
Impeller gap: 30mm
<< Condition 3 >>
Rotational speed: 5000 rpm
Peripheral speed: 105 [m / s]
Impeller gap: 20mm

As a result, all of the obtained broad fine particle group, fine particle group A and fine particle group B exhibited the following ““ resin content ratio to the whole fine particles ”(R)”.
In condition 1, R is 0.5% by mass or more and 5% by mass or less In condition 2, R is 5% by mass or more and 10% by mass or less In condition 3, R is 10% by mass or more and 15% by mass or less

  It was found that the content (R) of the resin covering the carbon fiber can be adjusted according to the use of the fine particle group A and the fine particle group B.

Comparative Example 1
The pulverization was performed in the same manner as in Example 1 except that a crusher mill, a pin mill, a cutter mill, a hammer mill, or an axial mill was used in place of the airflow pulverizer 11 used in Example 1, but each was pulverized. Under the usual grinding conditions of the apparatus, it was difficult to grind to a particle size of 120 μm or less. In addition, attempts were made to form fine particles over a long period of time, but the temperature of the particles was excessively increased, or the particles could not be suitably pulverized. In addition, there were particles having no rounded particle shape and exposed carbon fibers. Therefore, it was not possible to produce a suitable fine particle group A and fine particle group B.

Comparative Example 2
The pulverization was performed in the same manner as in Example 1 except that a jet mill was used instead of the airflow pulverizer 11 used in Example 1. Although the particle size distribution of the broad fine particle group was almost the same as that of Example 1, the cost was increased because the pulverization efficiency was extremely poor.
In addition, since the carbon fibers were exposed or the carbon fibers became fibrous and were taken out (discharged), even sampling was dangerous, and fine particles could not be produced without danger, and there was no danger. Fine particles could not be produced.

Comparative Example 3
In the cyclone device 21 used in Example 1, the same operation as in Example 1 was performed except that the circulation device 31 was not provided or the step (3) was not performed.
Only 1/10 of the fine particle group A was obtained in Example 1. In addition, the particle size distribution of the fine particle group B almost coincided with the particle size distribution of the broad fine particle group charged, and classification could not be suitably performed.

Comparative Example 4
A vibrating sieve classifier was used in place of the cyclone device 21 used in Example 1.
Classification took time (poor classification efficiency), and was not at all applicable in the field of recycling. In addition, the particle size distribution of the fine particle group A and the fine particle group B has a wide application range (where the particle group having the particle size distribution is used in many types of films, sheets, and structures), and the respective application ranges. In this case, the particle size distribution of the fine particle group A and the fine particle group B could not be adjusted appropriately.

Example 4
<< Production of Structure Containing Fine Particle Group A or Fine Particle Group B >>
A sol compound having the following formulation containing "polyvinyl chloride having a polymerization degree of 860 obtained by emulsion polymerization" as a binder resin was prepared. Hereinafter, polyvinyl chloride may be abbreviated as “PVC”. Hereinafter, the “particle group A or the particle group B” may be simply abbreviated as the “particle group”.

[Sol compound formulation]
Binder resin: Paste resin of PVC (degree of polymerization 860) 100.0 parts by mass Plasticizer: Diisononyl Phthalate (DINP) 35.0 parts by mass Dispersant: Higher fatty acid type, sorbitan monooleate 0.5 parts by mass Dispersant : Aliphatic hydrocarbon / carboxylic acid derivative carboxylic acid-based dispersant (BYK5125, manufactured by BYK) 0.5 part by mass Blowing agent: azodicarbonamide (manufactured by Otsuka Pharmaceutical Co., Ltd.) 2.0 parts by mass

30 parts by mass of the fine particle group A or the fine particle group B (each fine particle group) obtained in Example 1 was added to 100 parts by mass of the sol compound, and the mixture was stirred for 30 seconds with a mixer.
The stirred “fine particle mixed sol compound” was coated on paper with a thickness of 0.8 mm, placed in a normal air oven, and heated (fired) at 200 ° C. for 60 seconds, and foamed to a thickness of 2 mm. Next, by cooling to room temperature, a 2 mm-thick “structured foam foamed sheet (layered) foamed PVC sheet” containing each fine particle group was obtained.

Evaluation example 1
The structure (sheet) obtained in Example 4 was evaluated as follows. The evaluation results are also described below.

<Dispersibility>
The evaluation was performed in the state of a “fine particle mixed sol compound”.
A double groove grind meter manufactured by Daiyu Co., Ltd. was used to check for any aggregates.
As a result, there was no aggregate, and the particle size distributions of the fine particle groups A and B were each maintained.

<Bubble burn, discoloration, uneven color>
A test piece (150 mm × 150 mm × 2 mm in thickness) of the structure (sheet) was visually observed from above.
As a result, any of foaming burn, discoloration, and color unevenness could not be confirmed. No burning due to heat storage was observed. The coarse particles in which the fine particles were aggregated could not be detected visually.
The center and four corners of the sheet were measured with a colorimeter manufactured by Konica Minolta, Inc.
As a result, the color difference ΔE was within 0.2 (a color difference that cannot be determined with the naked eye).

<Color development>
Regarding the color development of the structure (sheet), a fixed color development (color development from black to dark gray) was obtained by adjusting the content of fine particles and the like and controlling the color tone for each lot.

<Fragility>
A test piece (150 mm × 150 mm × 2 mm thick) of the structure (sheet) was bent outward by 90 ° to check whether a crack was formed on the surface.
As a result, four cracks having a length of 3 mm were confirmed at the center, but it was determined that there was no problem because the cracks were not normally bent by 90 °.
If there is non-dispersion even in a normal processed pigment, such pinholes and cracks caused by such pinholes are generated, so it was considered that there was no problem in the fine particles themselves.

<Bleedability>
A "sol compound sheet" for evaluation was prepared in the same manner as in the structure (sheet) of Example 4, except that a mirror surface iron plate was used and a sol compound containing no fine particles was prepared.
A test piece (150 mm × 150 mm × 2 mm in thickness) of the structure (sheet) which is the foamed PVC sheet obtained in Example 4 was sandwiched between the sheets, and heated and pressed at 60 ° C. using a pressing machine at 120 ° C. For 10 minutes, a weight of 10 kgf was applied.
After release, it was confirmed whether or not the black color of the carbon fibers in the fine particles in the structure (sheet) of Example 4 was transferred to the sol compound sheet.
As a result, no black color was visually observed.

Example 5
<Evaluation of Filling Particles for “Film with Thickness of 40 μm” of Fine Particle Group A>
5 parts by mass of the fine particle group A obtained in Example 1, 1 part by mass of a sodium salt of carboxymethyl cellulose, 1 part by mass of a sodium salt of a polymethacrylic acid copolymer, and 15 parts by mass of a styrene-methacrylic acid copolymer. The mixture was charged into 70 parts by mass of N-methyl-2-pyrrolidone as a solvent, stirred with a magnetic stirrer, and then dispersed with a ball mill for 3 hours.
The resulting dispersion was applied on a polyethylene terephthalate (PET) film using a bar coater to a dry film thickness of 40 μm, and dried at 80 ° C. (solvent was distilled off) to obtain a conductive film. .

  The obtained conductive film had a large surface conductivity, and was useful as an electromagnetic wave shielding film, an electronic substrate shielding cover film, a metal oxidation preventing film, and an antistatic film.

Example 6
<Evaluation of Filling Particles for “Film with Thickness of 40 μm” of Fine Particle Group A>
A dispersion liquid was obtained in the same manner as in Example 5, except that "15 parts by mass of the styrene-methacrylic acid copolymer" in Example 5 was changed to "15 parts by mass of the main component of the epoxy resin".
Thereafter, 3 parts by mass of a curing agent of an epoxy resin was added, and the mixture was sufficiently stirred, and then applied on a polyimide film using a bar coater to a dry film thickness of 40 μm to obtain a conductive film.

  The obtained conductive film was extremely useful as an electromagnetic wave shielding film, an electronic substrate shielding cover film, a film for preventing metal oxidation, an antistatic film, a transparent conductive film, and the like because of its large surface conductivity.

Example 7
<Evaluation of Filling Particles for “Film with Thickness of 40 μm” of Fine Particle Group A>
The used amount (parts by mass) of the fine particle group A obtained in Example 1 was appropriately adjusted, and the fine particle group A was dispersed by using polypropylene as a binder, heating without solvent, and kneading with three rolls.
The film was cast to a film thickness of 40 μm and cooled to obtain a film.

The resulting film was black, absorbing solar heat, and not transmitting sunlight, thereby suppressing the growth of weeds, and was useful as an agricultural mulching film.
Further, by reducing the amount (parts by mass) of the fine particle group A, it was useful as a smoke film for a transparent member.

Example 8
<Evaluation of Fine Particle Group A as Filled Particles for "Fibers and Nonwovens">
5 parts by mass of the “fine particle group A obtained in Example 1” was kneaded with 20 parts by mass of polyethylene terephthalate, and then fiberized according to a conventional method to obtain a fiber. The obtained fiber was useful as a fiber of a nonwoven fabric to be described later, as a fiber for an insect-proof net, and the like.

  The fiber obtained above was made into a nonwoven fabric according to a conventional method. Since the nonwoven fabric had high mechanical strength and blackness, it was useful as a heat insulating nonwoven fabric for agricultural use and a nonwoven fabric for speakers.

Example 9
<Evaluation of fine particle group A as packing particles for packing>
The fine particle group A obtained in Example 1 was heated and kneaded with a silicone resin to obtain a packing for waterproofing electric materials. The obtained packing for waterproofing electric materials had excellent strength and water resistance.

Example 10
<Evaluation of Fine Particle Group A as Negative Electrode (Material)>
The fine particle group A obtained in Example 1 was added to a carbonaceous material (such as graphite particles) and molded to obtain a negative electrode of a lithium ion secondary battery. Since a suitable conductive network can be formed, by using it as a negative electrode, a lithium ion secondary battery having excellent battery characteristics can be provided.

  The above electrode is useful as a negative electrode (anode) for a lithium secondary battery, and also useful as a negative electrode (anode) for a fuel cell, a negative electrode (cathode) for an electrolytic cell, and the like.

Example 11
<Evaluation of Fine Particle Group A as Dispersed Particles in Paint>
The dispersions of Examples 5 and 6 containing the fine particle group A obtained in Example 1 can be used as a paint or a base material of the paint.

7 parts by mass of the fine particle group A obtained in Example 1, 1 part by mass of a sodium salt of carboxymethyl cellulose, 1 part by mass of a sodium salt of a polymethacrylic acid copolymer, 15 parts by mass of a novolak-type epoxy oligomer, and After stirring 4 parts by mass of silica powder with a stirrer, the mixture was dispersed in a ball mill for 3 hours.
The resulting dispersion is mixed with an epoxy curing agent and applied to a substrate. The resulting film exhibits excellent conductivity, waterproofness, and strength. It was extremely useful as a paint, a waterproof paint and the like.

Example 12
<Evaluation of Fine Particle Group A as Dispersed Particles in Paint>
A dispersion was obtained in the same manner as in Example 11, except that toluene diisocyanate was used instead of the novolak-type epoxy oligomer of Example 11.
The resulting dispersion is mixed with a curing agent containing a polyhydric alcohol and applied to a substrate, and the resulting film exhibits excellent conductivity, waterproofness, and strength. It was useful as an antioxidant paint, an antioxidant paint, a waterproof paint and the like.

Example 13
<Evaluation of fine particles B as “filled particles” for “sheet having a thickness of 70 μm”>
5 parts by mass of the fine particle group B obtained in Example 1, 1 part by mass of a sodium salt of carboxymethyl cellulose, 1 part by mass of a sodium salt of a polymethacrylic acid copolymer, and 15 parts by mass of a styrene-methacrylic acid copolymer. The mixture was charged into 70 parts by mass of N-methyl-2-pyrrolidone as a solvent, stirred with a magnetic stirrer, and then dispersed with a ball mill for 3 hours.
The obtained dispersion was applied onto a polyethylene terephthalate (PET) film using a bar coater so as to have a dry film thickness of 70 μm, and dried at 80 ° C. (the solvent was distilled off) to obtain a sheet.

The obtained sheet was useful as a conductive sheet, an antistatic sheet, and the like because of its large surface and bulk conductivity.
In addition, the obtained sheet is excellent in thermal conductivity and mechanical strength, and is excellent in absorbing radiant heat because it is black, so it is extremely useful as a heat conductive sheet, snow melting sheet, ground heating sheet, slip prevention sheet, etc. Was useful.

Example 14
<Evaluation of fine particles B as “filled particles” for “sheet having a thickness of 70 μm”>
A dispersion was obtained in the same manner as in Example 13, except that “15 parts by mass of the styrene-methacrylic acid copolymer” in Example 13 was changed to “15 parts by mass of the main component of the epoxy resin”.
Thereafter, 3 parts by mass of a curing agent of an epoxy resin was added, and after stirring well, a sheet having a thickness of 70 μm was obtained.

The obtained sheet was useful as a conductive sheet, an antistatic sheet, and the like because of its large surface and bulk conductivity.
In addition, the obtained sheet is excellent in thermal conductivity and mechanical strength, and is excellent in absorbing radiant heat because it is black, so it is extremely useful as a heat conductive sheet, snow melting sheet, ground heating sheet, slip prevention sheet, etc. Was useful.

Example 15
<Evaluation of fine particles B as “filled particles” for “sheet having a thickness of 70 μm”>
Using the fine particle group A obtained in Example 1 and polypropylene as a binder, heating without solvent and kneading with a three-roll mill, the fine particle group B was dispersed to obtain a sheet having a thickness of 70 μm according to a conventional method.

  The obtained sheet is black, absorbs radiant heat, is excellent in strength, and is inexpensive, and thus was extremely useful as a snow melting sheet, a ground heating sheet, an anti-slip sheet, an antistatic sheet, and the like.

Example 16
<Evaluation of Fine Particle Group B as Dispersed Particles in Paint>
The dispersions of Examples 13 and 14 containing the fine particle group B obtained in Example 1 can be used as a paint or a base material of the paint.

Further, 7 parts by mass of the fine particle group B obtained in Example 1, 15 parts by mass of a novolak type epoxy oligomer, and 4 parts by mass of sedimentable barium sulfate were stirred by a stirrer, and then dispersed by a ball mill for 3 hours.
By mixing (by combining) the obtained dispersion with an epoxy curing agent, excellent rust preventive paint, anticorrosive paint, heat resistant paint and the like can be provided.

Example 17
<Evaluation of Fine Particle Group B as Dispersed Particles in Paint>
A dispersion was obtained in the same manner as in Example 16, except that toluene diisocyanate was used instead of the novolak-type epoxy oligomer of Example 16.
By mixing the obtained dispersion with a curing agent containing a polyhydric alcohol, excellent rust preventive paints, anticorrosive paints, heat-resistant paints and the like could be obtained.

Example 18
<Evaluation of fine particle group B as packing particles for housings of building materials, furniture, and electrical products>
By using styrene-butadiene rubber, elastomer, polyurethane, polyamide, polyphenol, polyester, and polycarbonate as binders, reinforced building materials and automotive materials such as “Forged Composites (registered trademark), casting press method”, and “furniture” , "Electric product housing" was obtained.
They can be extruded, and have achieved weight reduction, high strength, and low cost.

In the method for producing a plurality of fine particle groups of the present invention, a carbon fiber-containing resin body, which is unnecessary CFRP, can also be used as a raw material, and can be recycled as a useful material to be blended with a binder resin or the like, and substantially remove the exposed carbon fiber. Is not contained, the surface is coated with a matrix resin and has excellent safety and physical properties, so various types of resin compounds, films, sheets, carbon fiber-containing structures, paints, so-called castings, building materials and furniture, It is widely used in the field of production or use of containers / housings, electrodes, etc .; in the field of waste disposal;
Further, the fine particle group A and the fine particle group B of the present invention each have a suitable particle size distribution having a wide field of application, and can also be regarded as a black pigment, a processed pigment, an extender, a filler, and the like. They are widely used in the fields where they are used.

DESCRIPTION OF SYMBOLS 11 Air flow crusher 12 Hopper 13 Motor 14 Impeller 21 Cyclone device 22 Transfer pipe 23 Cyclone part 24 Open damper 25 Closed damper 26 Final collection container 27 Central axis 31 Circulating device 32 Blower 33 Intake port 34 Exit 35 Particle group A circulation pipe 41 Super Particle collection device 42 Dust collector A Particle group A
B Particle group B
D Resin body containing carbon fiber E Crushed product of resin body containing carbon fiber F Broad particle group P Ultrafine particle group R Radius S Suction of cyclone device

Claims (11)

The carbon fiber-containing resin body is converted into at least two types of fine particle groups having different particle size distributions, that is, a fine particle group A having a particle size distribution of 1 μm to 30 μm and a fine particle group B having a particle size distribution of 3 μm to 120 μm. A method of producing a plurality of fine particle groups to be made,
A method for producing a plurality of fine particle groups, comprising: all of the following steps (1) to (4):
(1) A particle size of the carbon fiber-containing resin body is measured using an “air current pulverizer that has two or more impellers and pulverizes the particles to be pulverized by colliding target particles with a swirling air current generated by rotation of the impellers”. A pulverization step (2) of obtaining a broad particle group having a distribution of 1 μm or more and 120 μm or less “a cyclone device comprising a transfer pipe, a cyclone portion, a damper, and a final recovery container in this order from the airflow pulverizer side”. The cyclone device is operated while suctioning and transferring the broad particle group obtained in the pulverizing step (1) into the cyclone site, and the fine particles belonging to the fine particle group B are collected in the final collection container. Particulate Group B Collection Step (3) Further, the cyclone device is provided with an inlet between the outer peripheral inner wall of the cyclone portion and the central axis, which is connected as an outlet in the middle of the transfer pipe. A fine particle group A that allows the fine particles belonging to the fine particle group A to stay in the cyclone portion and the circulating device without being put in the final collection container during the operation of the cyclone device. Step (4) Close the damper, weaken or stop the operation of the circulating device, weaken or stop the operation of the cyclone device, and drop the fine particle group A to collect the fine particle group A. Collection process   The airflow pulverizer has a classification function inside, and the classified coarse particles are pulverized again inside, so that the classified fine particles are transferred to the cyclone site through the transfer pipe as a broad particle group. The method for producing a plurality of fine particle groups according to claim 1.   The method for producing a plurality of fine particle groups according to claim 1 or 2, further comprising a crushing step of crushing the carbon fiber-containing resin body before the crushing step (1).   The method according to any one of claims 1 to 3, further comprising an ultrafine particle group collecting step of collecting a group of ultrafine particles having a particle size of 1 μm or less while suctioning the cyclone device. A method for producing a plurality of fine particle groups according to the above.   In the pulverizing step (1), the broad particle group, the fine particle group A or the above by increasing the rotation speed or the peripheral speed of the impeller and / or increasing the impeller interval of the two or more impellers. 5. The content ratio of carbon fiber and resin of each fine particle group is adjusted by decreasing the "content ratio of resin to the whole fine particles" (R) of the fine particles belonging to the fine particle group B. The method for producing a plurality of fine particle groups according to claim 1.   A method for producing a fine particle group A containing carbon fibers and a resin and having a particle size distribution of 1 μm or more and 30 μm or less, wherein the “production of a plurality of fine particle groups” according to any one of claims 1 to 5. A method for producing a fine particle group A, comprising using the method.   A method for producing a fine particle group B containing a carbon fiber and a resin and having a particle size distribution of 3 μm or more and 120 μm or less, wherein the “production of a plurality of fine particle groups” according to any one of claims 1 to 5. A method for producing a fine particle group B, comprising using the method.   A fine particle group A obtained by using the method for producing the fine particle group A according to claim 6.   A fine particle group B obtained by using the method for producing the fine particle group B according to claim 7.   The fine particle group A according to claim 8, wherein the fine particle group A is used for a filling particle, a fiber material, a battery negative electrode material, or a dispersed particle for a paint of a film having a thickness of 40 µm or less. 10. The fine particle group B according to claim 9, which is used for a filler particle for a sheet having a thickness of 2000 µm or less, for a dispersion particle for a paint, for a filler particle for a building material or furniture, or for a filler particle for a housing of an electric appliance.