Metal porous cultivation medium and cultivation container

Abstract

To provide a metallic porous body cultivation medium and a cultivation container which are repeatedly usable and suitable for raising plants.SOLUTION: A metallic porous body cultivation medium 10 consists of a spongy metallic porous body 11 having an average pore diameter of 0.5 mm or more and 2 mm or less and a porosity of 65% or more and 98% or less. It is preferable that a top face of the spongy metallic porous body has recess parts for holding seeds, and it is preferable that the recess parts have a fall prevention part under the recess parts. It is preferable that the spongy metallic porous body is any one of titanium, titanium alloy and cobalt chromium alloy, and is subjected to alkali treatment on its surface. It is preferable that a side face of a cultivation container housing the metallic porous body cultivation medium is transparent such that the metallic porous body cultivation medium can be seen. It is preferable that a side face of the cultivation container has a cutout part for taking out the metallic porous body cultivation medium.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a cultivation medium and a cultivation container for plants, and more particularly to a porous metal cultivation medium and a cultivation container using a porous metal as a cultivation medium. [Background technology]

[0002] Plants are cultivated using soil or hydroponic cultivation, but soil cultivation, which is mainly done outdoors, is vulnerable to weather and natural disasters, and it is difficult to manage water volume and nutrients, making it difficult to achieve stable production plans and standards. In addition, when using soil for indoor cultivation, there are problems such as the need to secure a large area of ​​land and the possibility of soil getting lost in equipment.

[0003] For this reason, in recent years, soil-free hydroponic cultivation has begun to spread widely, such as in urban farms in the field of smart agriculture. Hydroponic cultivation is broadly divided into solid medium cultivation and hydroponic cultivation. Of these, solid medium cultivation is a cultivation style that uses a medium, and absorbent cotton or resin materials with a mesh structure are used to allow the roots of plants to extend. Indoor cultivation using solid medium cultivation is less affected by seasons and weather, and is less susceptible to damage from external factors such as insects and diseases.

[0004] Various materials have been proposed as solid cultivation media. For example, Patent Document 1 describes an invention related to a sprout cultivation sheet using a dry pulp nonwoven fabric. Patent Document 2 describes an invention related to a seedling cultivation medium using rock wool.

[0005] On the other hand, when extensive jaw bone defects occur due to tumors, trauma, etc., aesthetic and functional problems arise, so jaw bone reconstruction therapy using bone reconstruction materials is performed. As such reconstruction materials, Patent Document 4 describes an invention related to a bone reconstruction member using a titanium porous body with an interconnected porous structure suitable for bone formation. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2007-6868 A [Patent Document 2] JP 2001-37326 A [Patent Document 3] JP 2017-209328 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, conventional cultivation media such as absorbent cotton, resin materials, nonwoven pulp fabric, and rock wool with a mesh structure are disposable and cannot be reused. Therefore, there are concerns about the impact on the environment due to the continuous discharge of waste materials, and their use remains problematic in a world that is moving from a consumer society to a sustainable, recycling-oriented society.

[0008] The present invention solves the above-mentioned conventional problems by applying porous metal bodies, including porous titanium bodies used as bone reconstruction materials, to the field of plant cultivation, and provides porous metal cultivation media and cultivation containers that can be used repeatedly and are also suitable for cultivating plants. [Means for solving the problem]

[0009] In order to solve the above problems, the inventors utilized the development technology for porous metal bodies, including porous titanium bodies used as bone reconstruction materials, and investigated the structure, such as the average pore size and porosity, suitable for plant cultivation, thereby inventing a porous metal cultivation medium that can be used repeatedly and is also suitable for plant cultivation.

[0010] The porous metal cultivation medium of the present invention is made of a sponge-like porous metal having an average pore size of 0.5 mm or more and 2 mm or less and a porosity of 65% or more and 98% or less.

[0011] Also preferably, the sponge-like metal porous body has a recess on its upper surface for holding seeds.

[0012] It is also preferable that the recess has a drop prevention portion at a lower portion thereof.

[0013] Also preferably, the sponge-like metal porous body is made of any one of titanium, a titanium alloy, and a cobalt-chromium alloy, and the surface thereof is subjected to an alkali treatment.

[0014] The cultivation container of the present invention is a cultivation container containing the porous metal cultivation medium of the present invention, and is characterized in that the side surface is transparent so that the porous metal cultivation medium can be seen.

[0015] The cultivation container of the present invention is a cultivation container that contains the porous metal cultivation medium of the present invention, and is characterized by having a cutout portion on the side for removing the porous metal cultivation medium. Effect of the Invention

[0016] The porous metal cultivation medium of the present invention is made of a sponge-like porous metal, and therefore has superior strength compared to conventional cultivation media, and can be reused by washing after use. In addition, by setting the average pore size to 0.5 mm or more and 2 mm or less and the porosity to 65% or more and 98% or less, it becomes easier for roots to penetrate into the cultivation medium and difficult for plants to detach from the cultivation medium, and it is also difficult for seeds placed in the cultivation medium to penetrate into the pores and fall into the water, which is effective for seed germination and growth.

[0017] In addition, if the upper surface of the sponge-like metal porous body has a recess for holding seeds, the seeds placed in the cultivation medium can be held in the recess until they germinate, thereby preventing the seeds from floating on the water and becoming detached from the cultivation medium.

[0018] Furthermore, if a drop prevention portion is provided at the bottom of the recess, the seeds placed in the recess can be reliably prevented from entering the holes and dropping into the water.

[0019] Furthermore, when the sponge-like metal porous body is made of any one of titanium, a titanium alloy, and a cobalt-chromium alloy and has an alkali-treated surface, a plant growth-promoting effect may be obtained.

[0020] In addition, the cultivation container of the present invention is a cultivation container that houses the metal porous cultivation medium of the present invention, and the sides are transparent so that the metal porous cultivation medium can be seen, so that the roots that have penetrated into the cultivation medium are made visible, making it possible to observe the growth state, and a visual effect as an ornamental item can also be expected.

[0021] In addition, the cultivation container of the present invention is a cultivation container that contains the metal porous cultivation medium of the present invention, and has a cutout portion on the side for removing the metal porous cultivation medium, making it easy to wash and transfer the cultivation medium.

[0022] In this way, the porous metal cultivation medium and cultivation container of the present invention can be reused and are suitable for growing plants. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a perspective view showing a porous metal cultivation medium according to a first embodiment of the present invention. [Diagram 2] 1A is a perspective view showing a porous metal cultivation medium and a cultivation container according to a second embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along line aa-a. [Diagram 3] 1A is a perspective view showing a porous metal cultivation medium and a cultivation container according to a third embodiment of the present invention, and FIG. [Figure 4] FIG. 11 is a cross-sectional view showing a porous metal cultivation medium and a cultivation container according to a fourth embodiment of the present invention. [Diagram 5] FIG. 11 is a perspective view showing a porous metal cultivation medium and a cultivation container according to a fifth embodiment of the present invention. [Figure 6] FIG. 11 is a perspective view showing a porous metal cultivation medium and a cultivation container according to a sixth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Next, a porous metal cultivation medium and a cultivation container according to an embodiment of the present invention will be described with reference to Figs.

[0025] (Embodiment 1) Fig. 1 is a perspective view showing a porous metal cultivation medium 10 according to embodiment 1. As shown in Fig. 1(A), the porous metal cultivation medium 10 is made of a sponge-like porous metal body 11. Then, as shown in Fig. 1(B), a seed 1 is placed on the upper surface and allowed to germinate, and the roots are allowed to penetrate into the sponge-like porous metal body 11 to grow a plant. To germinate the seed 1, the sponge-like porous metal body 11 is placed in a cultivation container of an appropriate size and shape and immersed in water placed in the container.

[0026] The metal material of the sponge-like metal porous body 11 is preferably a corrosion-resistant material such as titanium, a titanium alloy, a cobalt-chromium alloy, or stainless steel, and in particular, titanium, a titanium alloy, or a cobalt-chromium alloy is preferred.

[0027] In particular, titanium and titanium alloys form an oxide film in the atmosphere, providing excellent rust resistance, and are lightweight but have a higher specific gravity than water, making them suitable for repeated use in water. They also have high biocompatibility, are non-toxic, and are less susceptible to ion elution, meaning they do not cause water pollution problems.

[0028] Methods for producing the sponge-like metal porous body 11 include sintering and laser welding, but it is difficult to give any shape or porosity with high precision. There is also a method using a 3D printer, but this has problems such as a long production time per piece. In contrast, there is a method called the "resin substrate impregnation sintering method" as described below, which is preferable as a method for producing the sponge-like metal porous body 11. The following describes the case where titanium is used as the material.

[0029] First, titanium powder is mixed with a binder such as isopropyl alcohol to form a titanium powder-containing slurry. A resin substrate is immersed in this titanium slurry, removed, and dried to expel the titanium slurry that has infiltrated into the voids in the substrate, leaving only the surface of the mesh-structured skeleton. Next, the substrate is heated to 600°C in a vacuum furnace to remove the resin substrate and binder. As a result, the titanium particles that were present on the substrate surface are bonded to each other while still in their original positions, forming a mesh structure that is almost the same as that on the resin substrate surface. Then, the substrate is fired at 1300°C to cause adjacent titanium powder particles to be diffusion-bonded to each other, completing a titanium porous body having a mesh-structured skeleton formed by titanium powder. This manufacturing method allows a resin substrate of any shape and porosity to be replaced with a metal porous body that is almost similar to the resin substrate.

[0030] The average pore size and porosity of the sponge-like metal porous body 11 will be described. The average pore size and porosity have a significant effect on the germination of the seeds 1 and their growth after germination. If the average pore size is too small, the roots will not easily enter the pores, and the plants will easily detach from the cultivation medium. Conversely, if the average pore size is too large, the seeds 1 placed in the cultivation medium will enter the pores and fall into the water, hindering their growth. Similarly, if the porosity is too small, the roots will not easily enter the pores, and the plants will easily detach from the cultivation medium. Conversely, if the porosity is too large, the seeds 1 will be more likely to fall, and the strength of the medium may decrease.

[0031] Therefore, the average pore size of the sponge-like metal porous body 11 is preferably 0.5 mm or more and 2 mm or less, more preferably 0.5 mm or more and 1.5 mm or less, and even more preferably 0.75 mm or more and 1.25 mm or less. The porosity of the sponge-like metal porous body 11 is preferably 65% ​​or more and 98% or less, more preferably 75% or more and 95% or less, and even more preferably 80% or more and 90% or less.

[0032] It is also preferable to subject the surface of the sponge-like porous metal body 11 to an alkali treatment. In particular, when any one of titanium, a titanium alloy, and a cobalt-chromium alloy is used as the metal material, it is preferable to modify the surface properties by carrying out an alkali treatment. Since the sponge-like porous metal body 11 has a porous structure, it is difficult to treat it uniformly all the way to the inside, but an alkali treatment using an aqueous sodium hydroxide solution is possible as a chemical treatment that can treat the inside.

[0033] As an example of an alkali-treated porous metal body, when an alkali-treated porous titanium body is used as a dental implant or artificial joint material, it is recognized that bone formation is promoted by the bioactivation effect. Therefore, in plant cultivation, the use of a surface-modified porous metal body as a cultivation medium may have a plant growth promoting effect.

[0034] The porous metal cultivation medium 10 of the invention according to embodiment 1 is made of a sponge-like porous metal 11, and therefore has superior strength compared to conventional cultivation media, and can be reused by washing after use. In addition, by setting the average pore size to 0.5 mm or more and 2 mm or less and the porosity to 65% or more and 98% or less, it becomes easier for roots to penetrate into the cultivation medium and difficult for plants to detach from the cultivation medium, and it is also difficult for seeds placed in the cultivation medium to penetrate into the pores and fall into the water, which is effective for the germination and growth of seeds.

[0035] Furthermore, when the sponge-like metal porous body 11 is made of any one of titanium, a titanium alloy, and a cobalt-chromium alloy and the surface is subjected to an alkali treatment, a plant growth promoting effect may be obtained.

[0036] In the following embodiments 2-6, the material, manufacturing method, average pore size and porosity of each sponge-like metal porous body are the same as those of the sponge-like metal porous body 11 of embodiment 1, and the effects thereof are also the same.

[0037] (Embodiment 2) FIG. 2 shows (A) a perspective view and (B) aa cross-sectional view of a porous metal cultivation medium 20 and a cultivation container 2 according to the second embodiment. The porous metal cultivation medium 20 is made of a spongy porous metal body 21 and is housed in the cultivation container 2. A recess 22 is formed on the upper surface of the spongy porous metal body 21. The recess 22 is for holding the seed 1 to be placed and preventing it from falling off the cultivation medium. That is, if the recess 22 is not formed on the upper surface of the spongy porous metal body 21 and the seed 1 is placed as it is, when water is poured into the cultivation container 2 so that the seed 1 is immersed in order to germinate the seed 1, the seed 1 floats on the water and falls off the cultivation medium. On the other hand, if the seed 1 is placed in the recess 22, the seed 1 will remain in the recess 22 even if it is immersed in water, and will not fall off the cultivation medium. The size and depth of the recess 22 can be appropriately set according to the seed 1 to be placed.

[0038] The metal porous cultivation medium 20 of embodiment 2 has a recess 22 for holding the seed 1 on the upper surface of the sponge-like metal porous body 21. Therefore, by holding the seed 1 placed in the cultivation medium in the recess 22 until it germinates, the seed 1 can be prevented from floating on the water and becoming detached from the cultivation medium.

[0039] (Embodiment 3) 3A and 3B are a perspective view and a bb-sectional view, respectively, showing a porous metal cultivation medium 30 and a cultivation container 3 according to the third embodiment. The porous metal cultivation medium 30 is made of a spongy porous metal body 31, and is housed in the cultivation container 3. Three rows of recesses 32, 32, 32 are formed on the upper surface of the spongy porous metal body 31. The recesses 32, 32, 32 are intended to hold the seeds 1 placed therein and prevent them from falling off the cultivation medium, similar to the recesses 22 in the second embodiment, and have the same function and effect.

[0040] (Embodiment 4) Fig. 4 is a cross-sectional view showing a porous metal cultivation medium and a cultivation container according to embodiment 4. Fig. 4(A) shows a porous metal cultivation medium 20 according to embodiment 2, in which a drop prevention part 23 is provided at the bottom of a recess 22 formed on the top surface of a sponge-like porous metal body 21. Fig. 4(B) shows a porous metal cultivation medium 30 according to embodiment 3, in which drop prevention parts 33, 33, 33 are provided at the bottom of recesses 32, 32, 32 formed on the top surface of a sponge-like porous metal body 31.

[0041] The drop prevention parts 23, 33 are intended to prevent the seeds 1 placed in the recesses 22, 32 from entering the pores and falling into the water. As described above, it is possible to make it difficult for the seeds 1 to enter the pores by setting the average pore size and porosity to preferred values, but the provision of the drop prevention parts 23, 33 can reliably prevent this.

[0042] As a method of forming the fall prevention parts 23, 33, a separate member can be attached to the lower part of the recesses 22, 32, but in the above-mentioned ``resin substrate impregnation sintering method,'' the density of the lower part of the recesses 22, 32 of the sponge-like metal porous body 21, 31 can be made denser than the surrounding area to form the fall prevention parts 23, 33.

[0043] The porous metal cultivation medium 20, 30 has fall prevention portions 23, 33 at the bottom of the recesses 22, 32, so that the seeds 1 placed in the recesses 22, 32 can be reliably prevented from entering the holes and falling into the water.

[0044] (Embodiment 5) 5 is a perspective view showing a porous metal cultivation medium 40 and a cultivation container 4 according to a fifth embodiment. The porous metal cultivation medium 40 is made of a spongy porous metal body 41 and is housed in the cultivation container 4. A plant 5 is planted in the spongy porous metal body 41, and roots 6 of the plant 5 are rooted inside the spongy porous metal body 41. The side of the cultivation container 4 is transparent, so that the roots 6 of the plant 5 can be seen from the outside. The side of the cultivation container 4 can be made of glass or acrylic resin.

[0045] The cultivation container 4 is a cultivation container containing a porous metal cultivation medium 40, and the sides are transparent so that the porous metal cultivation medium 40 can be seen, so that the roots 6 that have penetrated into the cultivation medium are made visible, making it possible to observe the growth state, and a visual effect as an ornamental item can also be expected.

[0046] (Embodiment 6) 6 is a perspective view showing a porous metal cultivation medium 30 and a cultivation container 3 according to a sixth embodiment. The side of the cultivation container 3 is provided with cutouts 34, 34. By providing the cutouts 34, 34, the upper side surface of the contained porous metal cultivation medium 30 appears, and the porous metal cultivation medium 30 can be taken out by hooking a finger on the upper side surface appearing from the cutouts 34, 34.

[0047] The cultivation container 3 is a cultivation container that contains a porous metal cultivation medium 30, and has cutouts 34, 34 on the sides for removing the porous metal cultivation medium 30, making it easy to wash and transfer the cultivation medium.

[0048] In this way, the porous metal cultivation medium and cultivation container according to embodiments 1-6 can be reused and are suitable for growing plants.

[0049] The porous metal cultivation medium and cultivation container according to the embodiment of the present invention have been described above, but the present invention is not limited to the above-described embodiment, and various other modifications are possible.

[0050] For example, the porous metal cultivation medium of the present invention can be used for promoting greening and adding aesthetic value, such as by growing plants underwater, growing plants in artificial ponds installed in urban spaces, and growing aquatic plants in ornamental fish tanks to prevent deterioration of water quality. [Explanation of symbols]

[0051] 1 seed 2 cultivation container 3 Cultivation container 4 Cultivation container 5 plants 6 roots 10. Porous Metal Cultivation Medium 11 Spongy metal porous body 20 Metal porous cultivation medium 21 Spongy metal porous body 22 Recess 23 Fall prevention part 30 Metal porous cultivation medium 31 Spongy metal porous body 32 Recess 33 Fall prevention part 34 Cutout 40 Metal Porous Cultivation Medium 41 Spongy metal porous body

Claims

1. A porous metal cultivation medium having an average pore size of 0.5 mm or more and 2 mm or less and a porosity of 65% or more and 98% or less, The porous metal cultivation medium is characterized in that the sponge-like porous metal is any one of titanium, a titanium alloy, and a cobalt-chromium alloy.

2. A metal porous cultivation medium as described in claim 1, characterized in that the surface of the sponge-like metal porous body has been subjected to an alkaline treatment.

3. 3. The porous metal cultivation medium according to claim 1, further comprising a recess on the upper surface of the sponge-like porous metal body for holding seeds.

4. The porous metal cultivation medium according to claim 3, characterized in that the bottom of the recess has a fall prevention portion.

5. A cultivation container containing the metal porous cultivation medium according to any one of claims 1 to 4, A cultivation container characterized in that the sides are transparent so that the metal porous cultivation medium can be seen.

6. A cultivation container containing the metal porous cultivation medium according to any one of claims 1 to 4, A cultivation container characterized in that it has a cutout portion on the side for removing the metal porous cultivation medium.

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