JPH08252031A - Soil for planting - Google Patents

Abstract

PURPOSE: To improve the balance of water permeability and water retention and to effectively reuse a resin foam which has been used once and abandoned by forming a water permeable layer made of prescribed resin particles. CONSTITUTION: This soil for planting is the one having a water permeable layer composed of resin particles having at least a part of foam existing on the surface extinguished by heat treatment of a resin foam. The water permeable layer constituting the soil for planting comprises the resin particles which are composed of >=50% of the resin particles having 0.5-30mm particle diameters and have 5-30mm average particle diameter and 0.1-0.5 true specific gravity. The resin particles may be packed into a baggy material to form the water permeable player.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a planting soil having a water permeable layer composed of resin particles formed by heat-treating a resin foam to reduce its volume, and effectively reuses a used resin foam. The present invention relates to a planting soil formed by doing.

[0002]

[Background of the Invention] While urban areas are becoming more and more functional, the amount of green spaces in urban areas is decreasing year by year. As the space for greening has decreased, the Heed Island phenomenon has progressed, and the desire for greenery by urban residents has been increasing. For this reason, efforts are being made to secure a greening space in the urban space, but it is now very difficult to secure a new greening space in the soaring urban space.

Under these circumstances, an attempt has been made to utilize a portion conventionally covered with concrete, such as a rooftop of a building, an underground parking lot, or a veranda, as a green zone. When plants are planted in such a part covered with concrete for growing and using, it is necessary to form soil for planting on the concrete, for example, to form a green zone on the roof of a building. If so, the structure of the building needs to be strengthened to withstand the weight of the soil. In addition, since these green areas are constructed on concrete, it is necessary to efficiently drain rainwater and the like, and to improve the soil so that the water required by plants can be retained.

By the way, the development of the physical distribution system greatly contributes to the achievement of the high functioning of the present city. In particular, the development of packaging technology is remarkable, and among these, resin foams using thermoplastic resins such as polystyrene and polyolefin have become the mainstream of packaging materials in place of the traditionally used wood and paper. ing. Since the packaging material made of such resin foam is lightweight and can be molded into a desired shape, a resin foam molded article of the desired shape is manufactured according to the application, and once used, it is discarded. , Is rarely used repeatedly. However, since such a resin foam is produced by foaming a raw material resin at a foaming ratio of about 20 to 100 times, the resin foam discarded after being used occupies a large volume. become.

Conventionally, they have been disposed of in such landfills, but recently, because of the large volume of disposal,
Its effective use is seriously considered. Many proposals have been made on the method of reusing the resin foam after being used once, and by utilizing the fact that the true specific gravity of the resin foam is low, this ground product is used as a soil for planting. Attempts have been made to use it.

Since the pulverized product of the resin foam is light in weight, even if it is laid on the roof of a building and used as artificial soil for planting, the building is not excessively weighted. However, since its true specific gravity is too low at about 0.03, it may flow or float during sprinkling, which is too low density for planting soil and there is no sense of stability. is there.

For planting resin foam volume-reducing particles formed by increasing the specific gravity by heat-treating such a light resin foam as described above to reduce the volume so that almost no bubbles remain. Although there are attempts to use it as soil, the resin foam volume-reduced particles obtained by reducing the volume of a pulverized product of the resin foam by a usual method have too small a particle diameter. Therefore, when such particles are laid, there is a problem that the particles are likely to be too densely clogged and conversely the drainage property is deteriorated, and root rot or the like is likely to occur in the transplanted plant. Further, it is possible to increase the particle size of the volume-reduced product to some extent by increasing the particle size of the resin foam pulverized product to be heat-treated, but conversely when the particle size of the volume-reduced product becomes too large. The water retention is reduced, and it becomes difficult to secure the amount of water necessary for growing plants.

Therefore, although there is a proposal to form a planting soil by using a pulverized product of a resin foam or a volume-reduced particle of a resin foam, in reality, such a pulverized product or volume-reduced particle is used. The full-scale soil for planting has not been put to practical use.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above situation.
The purpose of the present invention is to provide a planting soil that can be used practically in urban spaces, and to open the way to effectively use the used resin foam.

[0010]

SUMMARY OF THE INVENTION The planting soil of the present invention is a planting soil having a water permeable layer formed from resin particles in which at least some of the bubbles on the surface have disappeared due to the heat treatment of the resin foam, The water-permeable layer constituting the soil for planting has a particle diameter of 60% or more of the resin particles within a range of 0.5 to 30 mm, and an average particle diameter of the resin particles within a range of 5 to 30 mm. And the true specific gravity is in the range of 0.1 to 0.5.

That is, the resin particles used in the present invention are formed by heat-treating the resin foam, but the heat applied to the pulverized product of the resin foam during the heat treatment is limited to crush the resin foam. The resin particles are obtained by heat treatment to such an extent that the bubbles on the surface of the product disappear but the bubbles remain inside the pulverized product. As described above, the heat treatment is stopped when the surface of the pulverized product is heat-treated without performing the heat treatment of the pulverized product of the resin foam, so that the true specific gravity (g per cm ³ ) of the resin particles is , 0.2-0.6
By providing a layer made of such resin particles on the concrete, it is possible to show good water permeability and to retain the amount of water necessary for growing plants, and also to prevent resin foaming. Since it is not as light as a mere crushed body (the true specific gravity is not low), it is possible to prevent the permeable layer constituent from flowing or rising, and to provide a stable and solid planting soil.

[0012] Moreover, since this permeable layer has an appropriate weight, it is still lightweight, so that, for example, on the roof of a building, an underground parking lot, or a concrete such as a veranda,
By forming a water permeable layer composed of such particles,
There is no undue burden on structures such as buildings that form soil for planting.

[0013]

DETAILED DESCRIPTION OF THE INVENTION Next, the planting soil of the present invention will be specifically described. The planting soil of the present invention is a pulverized product of the resin foam, without causing the bubbles to disappear entirely.
It has a water permeable layer formed from resin particles that have been heat-treated so as to leave a certain amount of bubbles inside.

1 and 2 show cross sections of the planting soil of the present invention. The planting soil of the present invention is constructed on concrete that has been cast and hardened, as shown in FIGS. 1 and 2.

In FIGS. 1 and 2, concrete is numbered 1. In FIG. 1, resin particles 3 are contained in a water-permeable bag-shaped body 2 and placed on this concrete 1 to form a water-permeable layer 4.

The bag-shaped body 2 can be made of various water-permeable materials. Examples of fibers forming the bag-like body 2 include natural fibers such as hemp and synthetic resin fibers such as nylon, polyvinyl chloride, polypropylene and polyester. Of these compatible resins, polypropylene or nylon is preferable.

The form and size of the bag-like body 2 are not particularly limited, but the resin particles are usually contained in an amount of about 5 to 50 kg,
It is preferable that the size is such that about 10 to 30 kg can be filled. Such a size facilitates handling. In addition, by filling the bag-shaped body with resin particles, handling becomes easier, and in particular, workability in transportation and on-site is improved, and it is easy to ensure thickness uniformity and safety. Also improves.

The bag-like body 2 is a flat bag having an opening portion filled with the resin particles 2, and the opening portion has the resin particles 2
Is filled and then sealed. In the present invention, as the bag-like body 2, a bag-like body that is permeable to water and woven so that the filled resin particles do not leak is preferably used. The bag-shaped body 2 is also filled with the resin particles 2 smaller than the capacity of the bag-shaped body 2 to improve water permeability. However, if the resin particles 3 to be filled are less than the accommodation volume of the bag-shaped body 2, the resin particles 3 are likely to move in the bag-shaped body 2, so that the movement of the resin particles 3 in the bag-shaped body 2 is prevented. To prevent this, for example, after filling the resin particles 3 as shown in FIG.
It is preferable that the opening 5 of the bag-like body 2 is sewn together and the stitch 6 is also inserted in the central portion of the bag-like body 2.

In the embodiment shown in FIGS. 1 and 3,
The bag-shaped body 2 is filled with resin particles 2. The resin particles 2 can be produced by crushing a resin foam that has once been used as a molded body such as a cushioning material or a container, and subjecting the obtained crushed material to heat treatment. Examples of the resin foam used here include polystyrene, polyethylene, polypropylene, and AB which have been conventionally used.
Foams made of resins such as S, MBS and polyethylene terephthalate can be used. Particularly in the present invention, polystyrene resin such as polystyrene, polyolefin resin (eg polyethylene, polypropylene),
It is preferable to use a resin foam formed from a resin of any of various copolymers such as ABS or MBS.
A foam made of such a resin is used in a large amount and needs to be treated in a large amount, and since the heat treatment is easy, the treatment cost is low and the resin particles can be supplied at a low cost. In the present invention, the above resin foam may be used alone or different, but when the type of resin forming the resin foam is different, the heat treatment conditions may be different. It is desirable to treat each type of resin as much as possible.

During the heat treatment, these resin foams differ depending on the volume reduction state and conditions, the type of resin, etc.
Usually, it is roughly crushed to a size of 0.1 to 5 cm, preferably 0.5 to 3 cm.

The resin particles used in the present invention can be formed by heat-treating the resin foam roughly crushed in this way, but the resin particles of the present invention are different from the conventional heat treatment of the foam. Of the bubbles (mostly independent bubbles) formed in the resin foam, the bubbles in the vicinity of the surface of the coarsely pulverized material disappear, and the bubbles inside are heat-treated so as to remain.

In the conventional heat treatment, in order to make the volume of the resin foam as small as possible, the coarsely pulverized product was treated so that no bubbles remained, but as a result of the study by the present inventors, the degree of volume reduction is large. That is, even if a water-permeable layer of planting soil is formed using particles obtained by heat treatment so that the true specific gravity exceeds 0.6, the balance between water permeability and water retention is poor, and plant growth Difficult to form suitable soil.

The present inventor cultivated plants by changing the volume reduction rate of the resin foam by heat treatment, and the true specific gravity was in the range of 0.1 to 0.5, preferably 0.3 to 0.5. It was found that the resin particles obtained by heat-treating so as to fall within the range are particularly suitable for forming the water-permeable layer of the soil for planting. That is, by using the resin particles having such a true specific gravity, the balance between drainage and water retention of the water permeable layer becomes very good. In order to bring the true specific gravity into the above range, the coarsely pulverized product of the resin foam has a volume reduction ratio of preferably 1/6 to 1/60, particularly preferably 1
Heat treatment is performed within a range of / 10 to 1/40.

The resin particles having the volume reduction ratio as described above and the true specific gravity within the above range have a large degree of bubble disappearance due to heating at a portion relatively shallow from the surface of the particle, but at a deep portion, Since the effect of heat treatment is small, the residual rate of bubbles is large.

Therefore, the resin particles used in the present invention are lightweight, but have high rigidity. The average particle diameter of the resin particles used in the present invention needs to be in the range of 5 to 30 mm, and preferably 10 to 20 mm. Here, the resin particles can take various forms such as a spherical shape, an elliptic spherical shape, and a gostone shape depending on the shape of the coarsely pulverized material and the method of heat treatment, but in the present invention, the average particle diameter was measured for each particle. It is a value obtained by averaging the largest passing diameters.

Further, the resin particles used in the present invention have a particle size of about 50% (number) or more, preferably about 60% (number), of 0.5 to 30 μm. That is, even if it has the average particle diameter as described above, if a large amount of particles having a small particle diameter is contained, the water permeability of the planting soil of the present invention is lowered. To secure good water permeability by using resin particles in which about 50% or more, preferably about 60% or more, and more preferably about 80% or more of the whole has a particle diameter of 0.5 to 30 μm. Can be done.

In the soil for planting of the present invention, the resin particles as described above are filled in, for example, a bag-like body 2 as shown in FIG. 3, and as shown in FIG. The body 2 is placed to form the water permeable layer 4, and ordinary soil 8 or the like is deposited on the water permeable layer 4 to form the water permeable layer 4. When the plant 10 is planted in this soil, the roots of the plant gradually expand into the soil of the present invention and the whole is integrated. Even if the root grows in this way, since the water-permeable layer is formed by using the specific resin particles in the present invention, the water permeability in this water-permeable layer is unlikely to be lowered, and therefore the plant is not planted on the concrete 1. Despite the fact that the soil for planting is formed, root rot rarely occurs.

In the above embodiment, the resin particles 3 are added to the bag-like body 2.
However, it is not always necessary to fill the bag-like body 2 with the resin particles 3 and use the resin particles 3 so that the water-permeable layer 4 is directly formed on concrete as shown in FIG. 2, for example. 3 can also be arranged. In this case, when a large amount of soil enters the water permeable layer 4 formed by the resin particles 3, the water permeability of the water permeable layer 4 decreases, so the water permeable layer 4
It is preferable that the upper filter layer 22 is provided on top of which the soil 8 is deposited. The upper filter layer can be formed of a material that is permeable to water but impermeable to soil. For example, a non-woven fabric, a mesh body, a porous inorganic filter medium, a porous organic filter medium or the like can be used. The thickness of this upper filter layer varies depending on the type of forming material,
For example, when using a non-woven fabric, it is about 0.01 to 3 cm. Of these, thick ones are expensive, so
Usually, a thickness of about 1 cm is preferably used.

The water-permeable layer 4 can be laid directly on the concrete, but as shown in FIG. 2, the root-stopping sheet 21 can be placed on the concrete 1 and the water-permeable layer 4 can be formed on this. . In this case, the root-stopping sheet 21 can be made of the same material as the upper filter layer 22.

The root-stopping sheet 21 forms the water-permeable layer 4 in cooperation with the resin particles 3 and, by providing the lower filter layer 21 and the upper filter layer 22 as described above, the roots of the plant 10 can be root-stopped. Since it hardly penetrates through the sheet 21 or the upper filter layer 22 to grow, it also acts as a root stop for the plant, and it is possible to prevent a situation in which the root enters the concrete 1 and cracks the concrete.

It is not necessary to clearly distinguish the root-stopping sheet and the filter layer by their bubbles, and the root-stopping sheet can function not only as the filter layer but also as the root-stopping sheet.

The planting soil of the present invention has the water permeable layer 4 formed of the specific resin particles as described above, and the soil 8 is arranged on the water permeable layer 4. The thickness of the permeable layer 4 can be appropriately selected depending on the type of the plant 10 to be planted, the place where the soil for planting is formed, etc., but is usually about 1 to 30 cm, preferably about 3 to 20 cm. is there. The thickness of the soil 8 to be excavated on the permeable layer 4 can be appropriately selected in the same manner, but it can be appropriately selected depending on the type of plant to be planted and cannot be specified unconditionally. It is usually about 5 to 150 cm, preferably about 10 to 100 cm, and preferably about 1 to 50 times the thickness of the water permeable layer 4, and further 2 to
It is particularly preferable to make it about 30 times. By adding such an amount of soil, it is possible to effectively prevent the water-permeable layer 4 from rising.

The planting soil of the present invention has the water permeable layer 4 made of specific resin particles as described above, but can be variously modified within the scope of the present invention. .

For example, as shown in FIG. 4, when the bag-shaped body 2 filled with the resin particles 3 is placed on the concrete 1 to form the water permeable layer 4, the space between the concrete 1 and the bag-shaped body 2 is increased. The above-mentioned lower filter layer can be disposed on the above. That is, although the roots are relatively difficult to penetrate into the bag-shaped body 2, even if there are slight cracks in the concrete, the roots penetrate into the cracks, and the roots grow in the cracks to cause cracks. Since the root stop sheet 21 can be used to stop the growth of roots, the root stop sheet 21 can prevent the expansion of concrete cracks due to the root growth as described above. can do.

Although the rooting sheet 21 is provided on the concrete surface in FIG. 4, it may be provided on the water permeable layer 4. Although the filter layer is not provided on the upper portion of the bag-shaped body 2, the upper filter layer is provided on the water-permeable layer 4 formed by the communication of the bag-shaped body 2 and the soil 8 is formed.
Can also be prevented.

Further, in FIG. 5, a drainage mat 23 formed of a synthetic resin molded body, a synthetic resin foam molded body or the like is formed below the water permeable layer 4 formed by connecting the bag-shaped bodies 2 to each other.
Can also be arranged. The drainage mat 23 is a mat having a water retaining function and a recess 24 for drainage, and is formed of, for example, synthetic resin, synthetic resin foam or the like. The recess 2 formed in the drain mat 23
Although 4 has a drainage function, it is also possible to give this recess 24 a function of supplying air into the soil. By supplying air from the recesses 24, it becomes possible to promote root growth, so that the drainage of water can be further improved.

Further, in FIG. 5, rooting sheets 21, 21 are arranged on the upper part of the bag-like body 2 and the lower part of the bag-like body 2 (usually between the drain mat 23 and the bag-like body 2). Although an example is shown, the rooting sheet 21 does not need to be arranged above and below the bag-shaped body 2. When the root stop sheet is arranged, it is preferably arranged at least above the bag-shaped body 2.

A member formed of a lightweight member such as the drainage mat 23 formed of a resin foam, for example,
Buoyancy prevention means can be provided. Further, in the above description, an example in which normal soil is used on the water permeable layer 4 is shown, but instead of or together with this soil, resin pellets obtained by heat treating a resin foam at a high volume reduction rate ( It is also possible to use those having a true specific gravity of usually more than 0.6). Further, when the resin pellets are manufactured, it is possible to use the resin pellets mixed with the soil by heat-treating the mixture of the coarsely pulverized resin foam and the soil.

The concrete surface on which the planting soil of the present invention is laid may be a normal concrete placing surface, or the concrete surface may be waterproofed or the like. Further, it may be a casting surface of waterproof concrete (for example, resin-containing concrete) obtained by imparting waterproofness to the concrete itself.

The planting soil of the present invention can be formed on a concrete surface having no water permeability such as a rooftop of a building, a veranda, a terrace, an underground parking lot, etc. You can green the parts that couldn't.

[0041]

EFFECTS OF THE INVENTION Since the planting soil of the present invention forms a water permeable layer using specific resin particles obtained by heat treatment to such an extent that it is retained on the surface of the resin foam, it can be applied on concrete or the like. Even if the plant is planted by forming the planting soil of the present invention, a good balance of drainage and water retention by the permeable layer,
The plant can be satisfactorily grown.

In particular, by partially modifying the resin foam by the heat treatment as described above, the rigidity of the entire water permeable layer is increased and a firm soil can be formed.
Furthermore, the soil for planting of the present invention forms a water-permeable layer using lightweight resin particles, so that it is lighter than when simply using soil, so that the roof without particularly reinforcing the building, This planting soil can be laid on balconies, balconies, etc. That is, for example, by forming a permeable layer made of such particles on concrete such as a rooftop of a building, an underground parking lot or a veranda, an excessive burden is imposed on a structure such as a building forming soil for planting. There is no need to pay.

Further, since the resin particles used in the present invention can be formed by utilizing the resin foam which has been used once, the resin foam which has conventionally been problematic in the disposal method can be effectively reused. can do.

As described above, by using the planting soil of the present invention, it is possible to form a greening space in an urban space which is overcrowded and has a reduced greening space. It has the potential to slow down the progress of heat islands, and at the same time, can satisfy the urban residents' desire for green to some extent.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a planting soil of the present invention.

FIG. 2 is a diagram showing another embodiment of the planting soil of the present invention.

FIG. 3 is a perspective view showing an example of a bag-like body forming a water permeable layer used in the planting soil of the present invention.

FIG. 4 is a diagram showing another embodiment of the planting soil of the present invention.

FIG. 5 is a diagram showing another embodiment of the planting soil of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Concrete 2 ... Bag-shaped body 3 ... Resin particle 4 ... Water-permeable layer 8 ... Soil 10 ... Plant 21 ... Rooting sheet 22 ... Upper filter layer 23. ..Drainage mats 24 ... Recesses

Claims (7)

[Claims] 1. A planting soil having a water permeable layer formed of resin particles in which at least some of the bubbles on the surface have disappeared by heat treatment of a resin foam, the water permeable layer constituting the planting soil. However, 50% or more of the resin particles have a particle diameter of 0.5 to 0.5.
It is in the range of 30 mm, the average particle diameter of the resin particles is in the range of 5 to 30 mm, and the true specific gravity is 0.1 to 0.1.
A soil for planting, which is formed from resin particles within 5 ranges. 2. The water-permeable bag-shaped body is filled with the resin particles to form a water-permeable layer.
Soil for planting according to the item. 3. The soil for planting according to claim 1, wherein the water permeable layer is formed by spreading the resin particles. 4. A plant for planting according to any one of claims 1 to 3, wherein a water-permeable sheet is arranged above and / or below the water-permeable layer made of the resin particles. soil. 5. A pulverized product of a resin foam-molded article in which the resin particles are formed of at least one resin selected from the group consisting of polystyrene, polyolefin, ABS and MBS, and the volume of the pulverized product is 1/6 to. The soil for planting according to any one of claims 1 to 3, which is a resin particle formed by heat treatment so as to be within a range of 1/60. 6. The water-permeable layer comprising the resin particles has an average layer thickness in the range of 0.5 to 30 cm, and a thickness of 1 to 50 times the average thickness of the water-permeable layer on the water-permeable layer. The soil for planting according to any one of claims 1 to 3, wherein the soil of Sasano is soil. 7. The water-permeable layer comprising the resin particles is formed on a concrete slab with or without a lower filter layer interposed therebetween. Soil for planting described in the item.