JPH05317678A - Granulated product and method for producing the same - Google Patents

Abstract

(57) [Summary] [Purpose] An object is to provide a granulated product having excellent surface strength and a bulk density substantially equal to that of the powdery material itself, and a method for producing the same. [Structure] A granulated product having a core made of a powdered material, and the core being covered with a synthetic resin skin layer containing the powdery material that constitutes the core, or a synthetic resin skin layer of the granulated product is The granules were constructed such that they were further covered with cement material. Then, a large amount of the above granulated material is dropped or sprayed with a predetermined amount of a synthetic resin solution and the powdered material is stirred to entangle the powdered material through the synthetic resin solution to form a granular body. Further, the solvent of the synthetic resin solution was removed from this granular material by evaporation to solidify the synthetic resin for production.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lightweight aggregate for concrete, a core of a lightweight aggregate for concrete, a granulated material used as a lightweight material for a large-sized plastic molding, and a method for producing the same.

[0002]

2. Description of the Related Art Among foamed plastics, fiber-reinforced thermosetting type has excellent strength characteristics and is often used in industrial materials, but a large amount of powdery substances such as scraps and cutting powder generated in the processing process. Occurs in. In such powdery materials, some cutting powders are selected and used as thermosetting resin fillers, but other materials are landfilled as wastes or incinerated for processing. Is the current situation.

[0003]

However, there are problems that the landfill and incineration as described above are very costly, cause environmental damage, and waste resources. Therefore, the inventors
It was thought that granulation of such dust and cutting powder as above could be used as a lightweight aggregate for concrete and as a lightweight material for large plastic moldings.

However, in the granulated product obtained by the conventional granulation method in which the powdered material is mixed with the binder and solidified with the binder, or the powdery material is pressed and solidified, It turned out that such a problem occurs. That is, in the former method, since the powder material is firmly solidified with the binder, the granulated material becomes dense, and even if the lightweight powder material is used, the lightweight granulated material cannot be obtained. There is a problem to say. On the other hand, the latter method has a problem that sufficient mechanical strength cannot be obtained, and it may be damaged during mixing and kneading with concrete or the like.

In view of such circumstances, the present invention provides a granulated product having excellent surface strength and having a bulk density approximately the same as that of the powdery material itself, and a method for producing the same. Has a purpose.

[0006]

In order to achieve such an object, the granulated product according to the first invention comprises a core made of a powdery material, and the core comprises a powdery material which constitutes the core. The structure is such that it is covered with a synthetic resin outer layer. On the other hand, the granulated product according to the second invention is configured such that the synthetic resin outer layer of the granulated product according to the first invention is further covered with a cement material.

On the other hand, a predetermined amount of the synthetic resin solution is dropped or sprayed on a large amount of the powdery substance and the powdery substance is stirred to entangle the powdery substance through the synthetic resin solution to form a granular body. The solvent of the synthetic resin solution was removed from the granular material by evaporation to solidify the synthetic resin. In the above-mentioned constitution, the powdery substance constituting the core is not particularly limited, but for example, synthetic wood (glass fiber reinforced foamed hard urethane: Slonneo Lumber FFU manufactured by Sekisui Chemical Co., Ltd.)
Etc.), resin concrete pipes, chips such as fiber reinforced plastic (FRP), and synthetic resin waste powders such as polishing powders are preferably used for resource protection and environmental protection. Further, an antibacterial agent, a fertilizer or the like may be mixed with the powdery material or the synthetic resin solution depending on the use of the granulated material.

Most of the above-mentioned chips and polishing powder are powdery with no slippage, but among them, several cm to several 1
It may contain a large foreign substance up to 0 cm. Since such foreign matter is unsuitable as a raw material, it is preferable to remove it with a sieve of about 5 to 6 mesh and use the passed product as a raw material. Further, if the passing residue has the same composition as the raw material, it can be crushed and used again.

The synthetic resin constituting the outer skin layer is not particularly limited, and examples thereof include vinyl acetate, vinyl acetate-acrylic copolymers, melamine cross-linked types thereof, epoxy, polyester and the like. As the cement material coated on the outer side of the synthetic resin outer skin layer, sand may be mixed with the cement in addition to the cement. The amount of sand is preferably 60 wt% or less with respect to cement. 60wt
If it exceeds%, the cement layer cannot be molded.

The method for coating the cement material is not particularly limited, but for example, the granulated product according to the first invention (hereinafter referred to as "first granulated product") is dipped in a cement slurry prepared in advance. There is a method of adhering it to the surface by pulling it and hardening it, and a method of humidifying the primary granulated product and then applying cement powder to the surface to adhere it. For the granules with a thin cement layer, make a slurry of cement / water = 2 or less, put the primary granules into this, mix gently for a short time, and cement slurry on the entire surface of the primary granules. Attach. After that, it can be obtained by pulling it up using a net-like object, copying it onto a net which is sieving, continuing until the surface becomes non-greasy, and then curing.

On the other hand, for a granulated product having a thick cement layer, the above steps are repeated several times, or the primary granulated product is first moistened (this is
Wet it to such an extent that water droplets do not drop), place it on a net that performs a sieving motion, and while continuing this motion, sprinkle cement powder onto this and attach it to the primary granules. When the initial water content is consumed due to cement powder adhesion and the cement powder no longer adheres, it can be obtained by repeating the process of spraying a small amount of water and spraying the cement powder again.

If the surface of the primary granulated product as the raw material has water resistance, it can be used as it is as a raw material for forming the cement layer. However, the synthetic resin coating layer of the primary granulated product is hydrophilic. In the case where it is made of a synthetic resin (binder) having a property of being organic, the synthetic resin outer layer must be treated with a waterproofing agent and used as a raw material. The water-resistant agent can impart water resistance to the extent that the shape of the primary granulated product can be maintained in the step of forming the cement layer, and may be any one as long as it does not have a strong repulsion property against cement.

That is, for example, when a primary granulated product having a synthetic resin outer skin layer having poor water resistance such as PVA starch is used, deformation or collapse due to water may occur in the step of forming the cement layer. So in advance,
Disperse an appropriate amount of synthetic resin emulsion that is used as a vehicle for paints (e.g. vinyl acetate, vinyl acetate / acrylic copolymer, acrylic, epoxy, urethane, polyester, etc.) in a concentration to form a thin film and cure it. The surface-reinforced material may be used as a raw material. It is preferable to use those which show strength at 5 wt% or less with respect to the weight of the primary granulated product.

In carrying out the method for producing a granulated product according to the third aspect of the invention, the size of the powdery product is not particularly limited, but 70% or more of the final granulated particle size is 1/3 or less. preferable. Also, the particle size distribution of the powdery material is not particularly limited. On the other hand, regarding the shape of the powdery material, it is desirable that the ratio of the length (L) to the diameter or the width (d) is L / d = 50 or less.

Further, the synthetic resin solution is not particularly limited, and is determined depending on the intended use of the granulated product, and vinyl acetate, vinyl acetate / acrylic copolymer, or melamine thereof. A cross-linking type, an emulsion such as epoxy or polyester, or a water-soluble product is preferable. That is, in the case of a solvent-based synthetic resin solution, the solvent is immediately volatilized and the synthetic resin is solidified, so that workability is not so good.

When an emulsion type synthetic resin solution is used, several times as much water containing a synthetic resin as an active ingredient as a binder necessary to finally obtain the strength required by the granulated product is obtained. It is preferable to use the one diluted with. Synthetic resin solution (water dilution) adjusted in this way
Is preferably added in a volume ratio of about 0.5 to 3.0 times that of the raw material powder, and this ratio is determined by the particle size distribution of the raw material powder and the dilution concentration of the synthetic resin solution. When the synthetic resin solution diluted to a low concentration is used, the granules of the final strength required cannot be obtained unless all of them are used. The grain process will be repeated. On the other hand, when a synthetic resin solution diluted to a high concentration is used, the total amount of the raw material is insufficient, resulting in very unevenness.

There are no particular restrictions on the way in which the synthetic resin solution and the powdery substance are entangled. For example, the powdery substance is placed in a dish-shaped container and the synthetic resin solution is dropped or sprayed from above, and first, a glass rod is used. After forming a large number of granules that become small nuclei by stirring with etc., shake the container and vibrate horizontally,
Examples include a method of increasing the size of the granular material in a snowball manner.

In the case of such a method, the dropping or spraying of the synthetic resin solution can be performed several times. By dripping or spraying again, the granules that have become large by the first dropping or spraying serve as nuclei to form larger granules. Further, if the stirring time is prolonged, a firm and dense granular material can be obtained.

[0019]

According to the structure of the granulated product of the first invention, only the outer skin layer is made of a synthetic resin having excellent strength,
Since the core is formed of a powdery material having a porous and low bulk density, it is lightweight and has sufficient strength. Further, since the material of the powdery material to be the core is not particularly limited, it is possible to use the industrial wastes such as the cutting chips and the polishing powders of the above-mentioned synthetic wood etc. as the powdery material of the core, such as disposal and incineration. No processing is required.

On the other hand, according to the structure of the granulated product of the second invention, when it is used as a lightweight aggregate for concrete products,
Since the surface layer is made of cement material, the adjacent interface with concrete is homogenous, chemically unaffected and compatible with concrete. Of course, the powdery material of the core enables weight reduction, has excellent strength, and has no dimensional change.

On the other hand, according to the method for producing a granulated product according to the third invention, the synthetic resin solution is dropped or sprayed and agitated to cause entanglement between the powdery materials to form spherical particles. While growing, the size of the granules can be controlled by the amount of the synthetic resin dropped or sprayed, so that granules of various sizes can be freely produced.

Moreover, if the solvent is removed by evaporation, for example by drying the obtained granular material, migration (migration) occurs.
n, migration) occurs, and the synthetic resin inside the granular material goes out to the surface side of the granular material together with the solvent to strengthen the strength of the surface layer. Therefore, it is possible to obtain a granulated product having a strong synthetic resin skin layer formed on the surface layer with a small amount of synthetic resin.

[0023]

EXAMPLES The present invention will be described in detail below with reference to its examples. (Example 1) Cutting powder and polishing powder of fiber-reinforced thermosetting foamed plastic were collected and prepared as a powder. In addition, since the recovered powdery material contains foreign material used in the manufacturing process and chipping of the product, the particle size was adjusted using a sieve of 5 to 7 mesh.

A container (400 mm in length, 700 mm in width, 100 mm in depth) 1 having a pyramid shape of about 0.5 to 1 mm or a corrugated ridge 11 on the bottom as shown in FIG. The powdery material 2 prepared in this manner was put in so as to have a substantially uniform thickness of 5 to 10 mm. Then, each container was subjected to a horizontal 8-shaped motion in a vertical and horizontal amplitude width of about 200 mm in one cycle of about 2 seconds, and the synthetic resin as an active ingredient was adjusted to 5% vinyl acetate. Acrylic copolymer emulsion,
About 80 wt% was applied to the powder. When the emulsion spreads over the entire powder, the powder does not shake at all, but as it is, the entire container solidifies,
The mixture was agitated with a glass rod to form various large and small lumps of indefinite shape, which were changed into spherical particles by the 8-shaped movement of the container 1.

When all the emulsion was consumed, the size of the granules would no longer increase, so a small amount of the emulsion was sprayed again, and only the figure 8 motion was continued to make even larger granules. Then, when the diameter becomes about 10 mm, the work is terminated, the movement of the container 1 is stopped, and sieving is performed to select particles having a constant particle diameter of about 10 mm, and dried at 130 ° C. for about 2 hours. Then, as shown in FIG. 2, the powdery material 2 is placed on the core, and vinyl acetate containing the powdery material 2 is provided around the core. A granulated product 4 having a constitutional specific gravity of 0.7 in which a synthetic resin outer coat layer 3 made of an acrylic copolymer was formed was obtained.
The thickness of the synthetic resin outer layer 3 of the granulated product 4 is 0.2.
mm, the yield of the granulated product 4 from the raw material powder was 95% or more.

Regarding the remaining particles removed by sieving, smaller ones were allowed to grow further, and larger ones were crushed and used again as nuclei. As shown in FIG. 3, the granules 4 obtained in Example 1 were spread over the bottom and surface layers of the flower pot 41 to grow the foliage plant 42. Since the granules 4 are porous, they are kept warm. Since it has good properties and is excellent in moisturizing property, it grows well and does not cause root rot or the like even if a large amount of water is overdone. Figure 3
Medium 43 is soil. (Example 2) Cutting powder and polishing powder of fiber-reinforced thermosetting foamed plastic were collected and prepared as a powdery material, which was passed through an 8-mesh sieve and mixed with 20 wt% of glass fiber of about 3 mm cut. Using the thermosetting water-soluble epoxy resin as a synthetic resin solution in the same manner as above,
Granules were prepared and dried at 130 ° C. for 2 hours to obtain solid spherical granules having a dense surface. Almost equal amount of this was poured into an unsaturated polyester resin adjusted to room temperature, mixed and cast to obtain a block-shaped molded product 8 as shown in FIG. 4. The molded product 8 floated on water. It was

Moreover, when the molded product 8 was cut and the cross section thereof was observed, as shown in FIG. 5, the granules 81 were not broken and were uniformly dispersed in the molded product 8. (Example 3) In the same manner as in Example 1, a primary granule having a diameter of 5 mm was obtained. This primary granulated product is put into a cement slurry of cement / water = 1 in approximately the same volume as the cement slurry, gently mixed for about 30 seconds, and pulled up with a net of about 3.2 mm square, which is then cement slurry. After sieving until the droplets are broken, put it in a closed plastic container and cure it for 1 week at room temperature. As shown in Fig. 6, the surface layer of primary granules 5 has a cement layer of 0.27-0.32 mm. Granule 7 with 6 was obtained.

The granulated material 7 thus obtained was mixed with concrete as a lightweight aggregate to form a slate roof tile by a known method. As a result, a slate roof tile having sufficient strength could be obtained. Moreover, when the slate tile was cut and the cross-section was viewed, the granules 7 were not damaged at all, were uniformly dispersed inside the slate tile, and were firmly integrated with the cement. (Example 4) The primary granules having a diameter of about 10 mm obtained in Example 1 were put in water, mixed so that the surface was wet with water, and taken out onto a net having a sieve movement of about 8 mm. Cement powder was applied to this while sieving to adhere the cement to the surface.

When the water on the surface of the primary granule is consumed by the adherence of cement and the cement powder no longer adheres, water is sprayed to make the water excessive, and further cement powder adheres. The so-called process was repeated 4 times to obtain a granulated product whose surface was covered with a cement layer. The thickness of the cement layer of the obtained granulated product was about 1.5 to 2.0 mm. (Example 5) The surface of the cement was cemented in the same manner as in Example 4 except that the step of spraying water to make the water excessive and further adhering the cement powder was repeated 6 times. A granulate covered by layers was obtained.

The thickness of the cement layer of the obtained granulated product is about
It was 2.9 to 3.3 mm. (Example 6) Chips of a resin concrete pipe were collected and prepared as a powdery material. The recovered powder is
Since the product contains chippings and foreign substances used in the manufacturing process, the grain size was adjusted to 1 mm or less using a 20-mesh sieve. A granulated product having a size of about 5 mm was obtained from this adjusted powdered product in the same manner as in Example 1.

This granulated product had a specific gravity of 1.3 and a skin layer thickness of 0.3 mm. The granulated product according to the present invention and the method for producing the same are not limited to the above-mentioned examples. For example,
By supporting an electrolytic corrosion inhibitor such as higher fatty acid on the surface of the granulated product,
When this is used as an aggregate, the electrolytic corrosion inhibitor can be easily dispersed inside the reinforced concrete structure.

[0032]

As described above, the first aspect of the present invention is achieved.
Granules according to the invention of, if using a lightweight powder,
It has almost the same bulk density as a lightweight powder and has excellent surface strength, and is useful as a lightweight aggregate for concrete, or the core of lightweight aggregate for concrete, and a lightweight material for large plastic moldings. Can be used. In addition, if processed powder such as synthetic resin building material that has been conventionally discarded is used as a powdery material, it can play the role of resource saving and environmental protection.

On the other hand, the granulated product according to the second invention is the first
In addition to the effect of the granulated product of the invention of 1., it is compatible with concrete and is useful as a lightweight aggregate for concrete. On the other hand, in the method for producing a granulated product according to the third invention, since the synthetic resin solution is dropped or sprayed and agitated to cause entanglement between the powdery substances to grow into spherical particles. However, since the size of the granules can be controlled by the amount of the synthetic resin dropped or sprayed, the granules according to the first invention having different sizes, outer skin layer thicknesses and strengths can be freely and easily manufactured. Obtainable. Moreover, a granulated product having a sufficient surface strength can be obtained with a small amount of synthetic resin.

[Brief description of drawings]

FIG. 1 is a view for explaining one example of a method for producing a granulated product according to the present invention, which is a cross-sectional view of a granulation container.

FIG. 2 is a cross-sectional view of the granulated product obtained in Example 1.

FIG. 3 is a cross-sectional view showing a state where the granulated product obtained in Example 1 is put in a flowerpot as artificial soil.

FIG. 4 is a perspective view of a molded product obtained in Example 2.

5 is a cross-sectional view of the molded product of FIG.

FIG. 6 is a cross-sectional view of the granulated product obtained in Example 3.

[Explanation of symbols]

 2 powdered material 3 synthetic resin outer layer 4 granulated material 5 primary granulated material 6 cement layer 7 granulated material 81 granulated material

Claims (3)

[Claims] 1. A granulated product comprising a core made of a powdery material, the core being covered with a synthetic resin skin layer containing the powdery material constituting the core. 2. A granulated product, characterized in that the synthetic resin skin layer of the granulated product according to claim 1 is further coated with a cement material. 3. A predetermined amount of a synthetic resin solution is dropped or sprayed on a large amount of powder and the powder is stirred to entangle the powder through the synthetic resin solution to form granules. ,
A method for producing a granulated product, characterized in that a solvent of a synthetic resin solution is evaporated and removed from the granular material to solidify the synthetic resin.