JP2011239687A - Plant cultivating substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plant cultivating substrate which is excellent in infiltration of water, has fertilizer holding ability, water holding ability, air permeability, and drainage performance appropriate for plants, and can be placed on plant cultivating places such as roofs, pavements, or sides of roads, concrete flowerbeds, parking surfaces of parking lots to be used instead of soil.SOLUTION: Mixture of two kinds of ground products comprising a ground product of skinned flexible polyurethane foam and a ground product of unskinned flexible polyurethane foam, and natural organic materials comprising a medium formed of coconut husk fiber or the like is fixed in a predetermined shape by a binder, thus forming the plant cultivating substrate 10.

Description

  The present invention relates to a plant cultivation substrate used in place of soil.

  Conventionally, as a substrate for plant cultivation instead of soil, waste of products made of polyurethane foam or milled milled material produced during the production of polyurethane foam is mixed with a binder, and the resulting binder mixture is filled into a mold And a ribbon dead foam bonded with a binder (Patent Document 1). There is also a plant cultivation base composed only of polyurethane foam chips (Patent Document 2).

  However, plant cultivation bases using polyurethane foams are hydrophobic in polyurethane, so once dried, they exhibit water repellency and poor water infiltration. There is a problem that takes time. Also, since plant growth requires oxygen supply to the plant roots, the plant cultivation base is required to be breathable, but water-retained polyurethane foam provides sufficient breathability like soil. There is a problem that can not be. Furthermore, polyurethane foam has no fertilizer, and there is a problem that the fertilizer can be easily washed away with water.

  In addition, a block-shaped artificial soil in which a finely pulverized product of soft polyurethane foam and organic substance particles are bonded with a binder has been proposed (Patent Document 3). However, although the soft polyurethane foam has a sufficient water holding capacity, the resin itself is hydrophobic, so it cannot be said to be a hydrophilic material that absorbs water quickly. Furthermore, even if hydrophilicity is imparted to the flexible polyurethane foam, water, oxygen, and nutrients are necessary for the plant to root from seeds or seedlings, and materials that can provide an environment in which these coexist are necessary. is there.

  In addition, as a plant cultivation base, a cuboid-shaped open-celled hydrophilic polyurethane foam is hollowed out in the center and filled with peat moss to form a potting culture medium ( Patent Document 4). However, this cultivation base has a problem that it takes time to manufacture and a problem that the degree of freedom in planting positions is small.

JP 2004-59766 A JP 2007-97556 A JP-A-9-131128 JP 2004-298166 A

  This invention is made | formed in view of the said point, Comprising: It aims at provision of the base for plant cultivation which is excellent in the infiltration of water, water absorption hydrophilic property, and has the fertilizing power and rooting property suitable for a plant.

  The invention of claim 1 is a substrate for plant cultivation obtained by fixing and compressing a mixture of a pulverized product of a soft polyurethane foam that has undergone film removal and a pulverized product of a soft polyurethane foam that has not undergone film removal treatment and a natural organic material. Concerning.

The invention of claim 2 is characterized in that, in claim 1, the natural organic material is a coconut fiber or peat moss.
A third aspect of the present invention is characterized in that in the first or second aspect, the mixture contains at least one of zeolite, clay powder, pearlite, pumice, and pulverized coal.

  According to the first aspect of the present invention, the mixture containing the pulverized product of the soft polyurethane foam that has been film-removed and the pulverized product of the soft polyurethane foam that has not been subjected to the film-removal treatment is fixed and compressed with the binder. The structure was easy to contain air with voids, and the rooting of plants was greatly improved.

  According to invention of Claim 2, since the natural organic substance to be used is a coconut shell fiber and peat moss, water-absorbing hydrophilic property and fertilizing power become better.

  According to the invention of claim 3, by containing at least one of zeolite, clay powder, pearlite, pumice, and pulverized coal, the drainage of excess water is enhanced, and root rot caused by excessive water content that has conventionally occurred is further improved. It can be effectively prevented. In addition, zeolite can further increase the fertilizing ability, and can promote rooting and growth after germination.

It is a perspective view of the base for plant cultivation concerning one embodiment of the present invention. It is the schematic which shows the combined state of the ground material etc. in the base | substrate for plant cultivation. It is a figure which shows a mixed material and a water absorption hydrophilicity test result. It is a figure which shows the result of the water absorption hydrophilic property test in an Example. It is a figure which shows the result of the test which changed the density by compression. It is a figure which shows the test result of the number of rooting. It is a figure which shows the test result of fertilizer power. It is a schematic sectional drawing which shows the state at the time of a rooting number test.

  Hereinafter, embodiments of the plant cultivation substrate of the present invention will be described. A plant cultivation base 10 of the present invention shown in FIG. 1 is used in place of soil by being placed on a plant cultivation place such as a rooftop, a sidewalk or a roadside, a concrete flower bed, a parking surface of a parking lot, or the like. Yes, it has an appropriate three-dimensional shape such as a plate-like body having a predetermined thickness. Plants are planted on the plant cultivation substrate 10 by sticking a mat-like plant such as lawn on the upper surface of the plant cultivation substrate 10 or by forming an insertion slot made of a slit or the like and inserting a plant root into the insertion slot. Or by embedding seeds or bulbs. Further, seeds may be planted on the upper surface of the plant cultivation substrate 10 to germinate and grow. The plant suitable for the plant cultivation base 10 is not limited, but a ground cover plant such as lawn and tamariu, a plant having a low height, such as a flower or a shrub, is preferable.

  As shown in the schematic diagram of FIG. 2, the plant cultivation base 10 includes a soft polyurethane foam pulverized product 11, a soft polyurethane foam pulverized product 13 that has not been subjected to film removal treatment, and a natural organic matter 15. The mixture is compressed and fixed in a predetermined shape with a binder 17.

  The soft polyurethane foam from which the film has been removed is obtained by removing the cell film (bubble film) by subjecting the soft polyurethane foam to a film removal treatment, and has a three-dimensional network skeleton structure without the cell film. The film removal treatment is a known treatment for removing the cell membrane, such as a method in which the flexible polyurethane foam is immersed in an alkaline solution to melt the cell membrane, or the flexible polyurethane foam is accommodated in a sealed container, oxygen or the like. There is a method of destroying the cell membrane by filling it with a combustible gas and then igniting it for ignition. The soft polyurethane foam for film removal is preferably a slab polyurethane foam formed by slab foaming that is foamed at normal temperature under atmospheric pressure, and may be either a polyether type or a polyester type. Further, the film-removed soft polyurethane foam is not limited to one type, and a plurality of types may be used.

The film-removed flexible polyurethane foam has a density (JIS K 7222) of 20 to 90 kg / m ³ , a number of cells (JIS K 6400-1) of 5 to 80/25 mm, and a tensile strength (JIS K 6400-5) of 40 to 200 kPa. Elongation (JIS K 6400-5) 45 to 220%, air permeability (JIS K 6400-7 B method) 140 to 150 ml / cm ² / s are preferable. By setting the various physical property values of the film-free soft polyurethane foam within the above range, it is possible to obtain a plant cultivation substrate 10 suitable for plant growth conditions.

  A soft polyurethane foam that has not undergone film removal treatment is one that has not undergone film removal treatment. The soft polyurethane foam that has not been subjected to film removal treatment is preferably a slab polyurethane foam, and may be either a polyether type or a polyester type. Further, the soft polyurethane foam that has not been subjected to film removal treatment is not limited to one type, and a plurality of types may be used.

Soft polyurethane foam that has not undergone film removal treatment has a density (JIS K 7222) of 20 to 90 kg / m ³ , a cell number (JIS K 6400-1) of 30 to 80 pieces / 25 mm, and a tensile strength (JIS K 6400-5). The thing of 65-200 kPa, elongation (JIS K 6400-5) 80-220%, air permeability (JIS 6400-7 B method) 5-100 ml / cm < ² > / s is preferable. By setting the various physical property values of the soft polyurethane foam that has not been subjected to film removal treatment within the above range, it is possible to obtain the plant cultivation substrate 10 suitable for plant growth conditions.

  The size of the pulverized product of the removed soft polyurethane foam and the pulverized product of the soft polyurethane foam not subjected to the film removal treatment is preferably 5 to 20 mm. By setting the size of both pulverized products within the above range, favorable growth conditions can be imparted to the plant. By using a pulverized product of a soft polyurethane foam that has undergone film removal and a pulverized product of a soft polyurethane foam that has not been subjected to film removal treatment, it can be used as a substrate for plant cultivation that cannot be obtained individually, and the plant of soil The growth conditions can be given.

  As natural organic substances, palm husk (coconut shell), peat moss, moss, mulch, pulp, compost, rice husk, etc. can be used alone or in combination. Among these, from the viewpoint of water absorption, water retention, and ease of handling, among the coconut shell fibers (coconut shell fibers), those with particularly fine fibers are preferred as natural organic substances.

  The mixture may further include at least one kind of inorganic materials composed of zeolite, clay powder, pearlite, pumice, and pulverized coal. By including at least one of zeolite, pearlite, and pumice, the air permeability and excess water drainage of the plant cultivation base 10 can be improved, and root rot due to excessive moisture can be more effectively prevented. . In addition, zeolite and clay powder increase fertilizer retention, facilitate manure management and promote growth.

  The binder is used to fix each component contained in the mixture, that is, the pulverized product, natural organic material, and in some cases zeolite, etc., to fix the mixture, and is used to bind the polyurethane foam chip. Known ones can be used. For example, it is a one-component or two-component urethane-based binder, and among these, a one-component type urethane-based binder that cures with moisture such as moisture is preferable. Specific examples include methylene diphenyl diisocyanate (MDI) or a prepolymer thereof (MDI prepolymer).

  The amount of each component in the mixture is preferably in the following range when the mixture excluding the binder is 100% by weight. The total of the pulverized product of the removed soft polyurethane foam and the pulverized product of the soft polyurethane foam not subjected to film removal is 55 to 78% by weight, the natural organic material is 12 to 35% by weight, and the inorganic material is 0 to 10% by weight. It is. The binder is 5 to 20 parts by weight. When the amount of the binder is less than 5 parts by weight, the binder is insufficient and the fixing force of the mixture becomes weak, and each component constituting the plant cultivation base 10 is likely to fall off. On the other hand, if the amount of the binder exceeds 20 parts by weight, the amount of the binder is too large, which is not preferable for plant growth. The weight ratio of the pulverized product of the removed soft polyurethane foam and the pulverized product of the soft polyurethane foam that has not been subjected to film removal is preferably 1: 1 to 1:15, more preferably 1: 1 to 1. : 6, more preferably 1: 2 to 1: 5. When the ratio of the pulverized product of the soft polyurethane foam that has been removed from the film is less than the above range, the air permeability of the plant cultivation base becomes poor, while when it exceeds the above range, the water retention becomes poor.

A base for plant cultivation by compressing a mixture of a pulverized product of a soft polyurethane foam that has been removed from the film, a pulverized product of a soft polyurethane foam that has not been removed, a natural organic material, and, in some cases, an inorganic material, and fixing it with a binder. It is said.
Compression refers to compression so that the density becomes higher than the density of the soft polyurethane foam before pulverization. The compression ratio is preferably 2 to 8 times. More preferably, 2-6 times is good. Here, the compression ratio is the average density of the soft polyurethane foam before pulverization, which is a value obtained by dividing the density of the molded product. For example, the density of the molded product is equal to the density of the soft polyurethane foam before pulverization. When it is 3 times, the compression ratio is 3 times. The molded product includes the coconut fiber, inorganic material, etc. shown in Table 1.

  The plant cultivation substrate is manufactured by a pulverized product forming process, a mixture preparing process, a binder mixing process, and a bonding process.

In the pulverized product forming step, the film-removed soft polyurethane foam and the non-film-removed soft polyurethane foam are each pulverized to a predetermined size by a pulverizer, and the film-removed soft polyurethane foam is removed from the pulverized product. A pulverized product of soft polyurethane foam that has not been membrane-treated is formed.
In the mixture preparation process, a predetermined amount of the pulverized product of the removed soft polyurethane foam, the pulverized product of the soft polyurethane foam that has not been subjected to the film removal process, and a natural organic material, or in some cases, an inorganic material, is charged into the mixing and stirring device. To produce a mixture. Thus, by mixing the pulverized product, natural organic matter, etc. before mixing the binder, the pulverized product, natural organic matter, etc. can be mixed uniformly.
In the binder mixing step, a predetermined amount of the mixture and binder is put into a mixing tank, and mixed and stirred with a stirring device such as a mixer to produce a binder mixture.
In the binding step, the binder mixture is put into a press-compressible mold, compressed so that the molded product has a desired density, and the binder is cured to fix the mixture to form a plant cultivation substrate. To do. Thereafter, the plant cultivation substrate is removed from the mold.

A soft polyurethane foam (density 30 kg / m ³ , number of cells 8/25 mm, tensile strength 40 kPa, elongation 100%) obtained by removing a film from a polyether type soft polyurethane foam obtained by slab foaming is obtained by a pulverizer. A pulverized product of soft polyurethane foam which was pulverized to a particle size of 10 to 15 mm and removed from the film was formed. Further, a polyether type soft polyurethane foam (density 30 kg, number of cells 50/25 mm, tensile strength 88 kPa, elongation 150%) obtained by slab foaming is pulverized to a particle size of 10 to 15 mm by a pulverizer. A pulverized product of soft polyurethane foam which was not subjected to film treatment was formed. The pulverized product of the soft polyurethane foam thus removed and the pulverized product of the soft polyurethane foam that has not been subjected to the film removal, and coconut husk, perlite, clay powder, pumice, zeolite, and moisture-curing type A liquid type isocyanate prepolymer binder (trade name: KF-1, manufactured by Inoac Corporation) was mixed at a ratio shown in the formulation tables of FIGS. 3 to 7 to produce a binder mixture. At that time, a pulverized product of the polyurethane foam and coconut shells were first mixed to produce a mixture, and then a binder was mixed into the mixture.

  3034 g of the binder mixture thus obtained was put into a mold cavity (450 × 450 × 100 mm) and compressed, and the binder was cured by water vapor and heating to fix the mixture, thereby FIG. A plant cultivation substrate having the specimen number shown in FIG. 7 was formed, and then the plant cultivation substrate was removed from the mold.

  Note that the specimens D-1, D-2, and D-4 in FIG. 3 correspond to comparative examples because the polyurethane foam is configured only without film removal, while the specimen D-3 has the polyurethane foam removed. Since it is configured with none and with film removal, it corresponds to the embodiment. Each of the specimens E-1 and E-2 in FIG. 4 corresponds to an example because the polyurethane foam is constituted with and without a film removal and contains a natural organic substance. Each of the specimens A-1 to A-3 in FIG. 5 corresponds to an example because the polyurethane foam is configured without a film removal and with a film removal and contains a natural organic substance. Specimen C-1 in FIG. 6 corresponds to a comparative example because the polyurethane foam is configured only without film removal, while specimens C-2 and C-3 have the polyurethane foam without film removal. In addition, since it contains natural organic matter, it corresponds to the embodiment. Each of the specimens B-1 to B-5 in FIG. 7 corresponds to the example because the polyurethane foam is composed of a film without a film removal and with a film removal, and contains a natural organic substance. On the other hand, the specimen B-6 Corresponds to a comparative example because it does not contain natural organic matter. Moreover, the density in FIG. 3 thru | or FIG. 7 is a density of the base | substrate for plant cultivation.

  Specimens D1 to D4 in FIG. 3 were prepared by different types of mixed materials such as coconut shells mixed with polyurethane foam, and water absorption hydrophilicity tests were performed on the specimens D1 to D4. In the water absorption hydrophilicity test, the specimen size was 100 × 100 × 20 mm, the specimen was vertically placed, the lower part was submerged 2 cm in water, and the height at which the water was sucked up in the vertical direction was measured after 30 minutes and 3 hours. . In the graph of the test results in FIG. 3, the test specimen of coconut shell is specimen D-1, the specimen of pearlite is specimen D-2, the specimen of peat moss is specimen D-3, and the specimen without mixing is specimen D. Corresponds to -4. As shown in the graph of the test results, the specimen D-4 without the mixed material has the poorest water-absorbing hydrophilic property, and the specimen D-3 (Example) having the mixed material as peat moss has the best water-absorbing hydrophilic property. It was.

  Specimen E-1 in FIG. 4 is composed of coconut husk only, while specimen E-2 is composed of coconut husk and clay powder. The water absorption hydrophilicity test was conducted. In the graph of the test results in FIG. 4, the specimen of coconut shell is specimen E-1, and the specimen of coconut shell + clay powder is specimen E-2. As shown in the graph of the test results, both the specimens E-1 and E-2 had good water-absorbing hydrophilicity.

Specimens A-1 to A-3 (both examples) in FIG. 5 have different densities of the plant cultivation base by changing the compression during production. The water-absorbing hydrophilicity test was performed on A-3. In the test result graph of FIG. 5, the specimen having a density of 90 kg / m ³ is specimen A-1, the specimen having a density of 120 kg / m ³ is specimen A-2, and the specimen having a density of 150 kg / m ³ is specimen A. -3. As shown in the graph of the test results, the water-absorbing hydrophilicity became higher as the density of the plant cultivation substrate increased.

  Specimens C-1 to C-3 in FIG. 6 are obtained by changing the mixing amount (%) of the polyurethane foam subjected to the film removal treatment in the plant cultivation base. The specimens C-1 to C- A rooting number test was performed on three. As shown in FIG. 8, in the rooting number test, each specimen S cut to 250 mm × 250 mm is placed on a resin drainage base M, and each specimen S is saturated. After irrigation, Korai Shiba (TM-9 (registered trademark) manufactured by Toyota Roof Garden) T, similarly cut to 250 mm x 250 mm, was placed on each specimen S, and each specimen S was saturated twice in the morning and evening. Irrigation was performed by hand irrigation until the condition was reached, and the number of root systems penetrating to the back side of each specimen S was measured by visual measurement every two weeks. The rooting number test was conducted for 4 weeks from June 18, 2009. In the test result graph of FIG. 6, the specimen having a film removal amount of 0% is the specimen C-1 (Comparative Example), the specimen having the mixing amount of 12% is the specimen C-2 (Example), and the mixing amount is 18 % Of the specimen is specimen C-3 (Example). As shown in the graph of the test results, the number of roots increased as the mixing amount of the polyurethane foam subjected to film removal increased, and the rooting property was good.

Specimens B1 to B6 in FIG. 7 are different in mixed materials such as coconut shells, and a fertilizer retention test was performed on the specimens B1 to B6. The fertilizer retention test was performed by measuring the cation exchange capacity (CEC) by the Schöllenberger method. In the test result graph of FIG. 7, the specimen of the coconut shell is specimen B-1, the specimen of peat moss is specimen B-2, the specimen of clay powder is specimen B-3, and the specimen of zeolite is the specimen. The specimens for B-4 and pulverized coal correspond to specimen B-5, and the specimen for the control group corresponds to specimen B-6. As shown in the test results, the specimens B1 to B5 mixed with a mixed material such as coconut shells (all examples) are more than the specimen B-6 (comparative example) with no mixed material such as coconut shells mixed therein. Fertilizer was high. In particular, the specimen containing both coconut husk and zeolite had the highest fertilizing power.
In addition, the quality standard of the material for soil (cultivation) of the Japanese Landscaping Society stipulates that the value of cation exchange capacity is 6 cmolc / kg or more, and B-1 to B-4 are higher than this standard value and It is a cultivation base suitable for cultivation.

DESCRIPTION OF SYMBOLS 10 Plant cultivation base 11 Pulverized product of soft polyurethane foam after film removal 13 Pulverized product of soft polyurethane foam not subjected to film removal 15 Natural organic matter

Claims (3)

  A substrate for plant cultivation obtained by fixing and compressing a mixture of a pulverized product of a removed soft polyurethane foam and a pulverized product of a soft polyurethane foam that has not been subjected to film removal and a natural organic material, with a binder.   2. The plant cultivation substrate according to claim 1, wherein the natural organic material is a coconut fiber or peat moss.   The plant cultivation substrate according to claim 1 or 2, wherein the mixture contains at least one of zeolite, clay powder, pearlite, pumice, and pulverized coal.

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