JP7616643B2 - Metal porous cultivation medium and cultivation container - Google Patents

Description

The present invention relates to a cultivation medium and a cultivation container for plants, and more specifically to a porous metal cultivation medium and a cultivation container that use a porous metal as the cultivation medium.

Plants are grown using soil or hydroponic cultivation, but soil cultivation, which is mainly done outdoors, is vulnerable to the effects of weather and natural disasters, and it is difficult to manage the amount of water and nutrients, making it difficult to achieve stable production plans and standards. Furthermore, when using soil for indoor cultivation, there are problems such as the need to secure a large amount of land and the possibility of soil getting lost in equipment.

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 can be broadly divided into solid medium cultivation and hydroponic cultivation. Of these, solid medium cultivation is a cultivation style that uses a medium, and uses absorbent cotton or resin materials with a mesh structure that allows the plant roots to extend. Indoor cultivation using solid medium cultivation is less affected by the season and weather, and is less susceptible to damage from external factors such as insects and diseases.

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

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

JP 2007-6868 A JP 2001-37326 A JP 2017-209328 A

However, conventional cultivation media such as absorbent cotton, resin materials, nonwoven pulp fabric, and rock wool, which have a mesh structure, are disposable and cannot be reused. This raises concerns about the impact on the environment from the continuous discharge of waste materials, and their use remains problematic in a world that is moving away from a consumer society and towards a sustainable, recycling-oriented society.

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 growing plants.

In order to solve the above problems, the inventors have utilized the development technology for porous metal bodies, including porous titanium bodies used as bone reconstruction materials, and by examining the structure, such as the average pore size and porosity, suitable for plant growth, they have invented a porous metal cultivation medium that can be used repeatedly and is also suitable for plant growth.

The porous metal cultivation medium of the present invention is made of a sponge-like porous metal with 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.

It is also preferable that the upper surface of the sponge-like metal porous body has a recess for holding seeds.

It is also preferable that the lower part of the recess has a fall prevention part.

More preferably, the sponge-like metal porous body is made of one of titanium, a titanium alloy, and a cobalt-chromium alloy, and the surface is treated with an alkali.

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 in that the sides are transparent so that the porous metal cultivation medium can be seen.

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.

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 the cultivation medium and the plant is less likely to detach from the cultivation medium, and seeds placed in the cultivation medium are less likely to penetrate into the pores and fall into the water, which is effective for the germination and growth of seeds.

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, preventing the seeds from floating on the water and becoming detached from the cultivation medium.

In addition, if the bottom of the recess has a fall prevention part, it is possible to reliably prevent the seeds placed in the recess from falling into the holes and falling into the water.

In addition, if the sponge-like metal porous body is made of titanium, a titanium alloy, or a cobalt-chromium alloy and the surface has been treated with alkali, it may be possible to achieve a plant growth promoting effect.

The cultivation container of the present invention is a cultivation container that contains the porous metal cultivation medium of the present invention, and the sides are transparent so that the porous metal 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 it is also expected to have a visual effect as an ornamental item.

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

In this way, the porous metal cultivation medium and cultivation container of the present invention can be reused and are suitable for growing plants.

FIG. 1 is a perspective view showing a metal porous cultivation medium according to a first embodiment of the present invention. 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. 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. 1B is a cross-sectional view taken along line bb. 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. FIG. 11 is a perspective view showing a metal porous cultivation medium and a cultivation container according to embodiment 5 of the present invention. FIG. 13 is a perspective view showing a metal porous cultivation medium and a cultivation container according to a sixth embodiment of the present invention.

Next, the porous metal cultivation medium and cultivation container according to an embodiment of the present invention will be described with reference to Figures 1 to 6.

(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. 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.

The metal material for 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, with titanium, a titanium alloy, or a cobalt-chromium alloy being particularly preferred.

Titanium and titanium alloys in particular form an oxide film in the atmosphere, making them highly rust-resistant, 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 not prone to ion leaching, meaning they do not cause water pollution problems.

Methods for manufacturing the sponge-like metal porous body 11 include sintering and laser welding, but it is difficult to give the desired shape and porosity with high precision. There is also a method using a 3D printer, but this has problems such as the long production time per unit. In contrast, there is a method called the "resin substrate impregnation sintering method" described below, which is preferable as a method for manufacturing the sponge-like metal porous body 11. Below, we will explain the case where titanium is used as the material.

First, titanium powder is mixed with a binder such as isopropyl alcohol to form a titanium powder-containing slurry. The 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 structure skeleton. Next, the substrate is heated to 600°C in a vacuum furnace to remove the resin substrate and binder. This causes the titanium particles present on the substrate surface to bond together while still in their original positions, forming a mesh structure that is almost the same as the surface of the resin substrate. The substrate is then fired at 1300°C to cause adjacent titanium powder particles to diffuse and bond together, completing a titanium porous body with a mesh structure 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 original.

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 have difficulty entering the pores, and the plants will be more likely to 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 growth. Similarly, if the porosity is too small, the roots will have difficulty entering the pores, and the plants will be more likely to detach from the cultivation medium. Conversely, if the porosity is too large, the seeds 1 will be more likely to fall, and there is a risk of the strength decreasing.

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.

It is also preferable to subject the surface of the sponge-like metal porous body 11 to an alkali treatment. In particular, when the metal material is titanium, a titanium alloy, or a cobalt-chromium alloy, it is preferable to modify the surface properties by performing an alkali treatment. Since the sponge-like metal porous 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 a chemical treatment that can treat the inside.

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 has been found to promote bone formation through its bioactivating effect. Therefore, when a porous metal body that has been surface-modified is used as a cultivation medium for plant cultivation, it may be possible to achieve a plant growth promoting effect.

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 cleaning 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, the roots can easily penetrate the cultivation medium and the plants are less likely to detach from the cultivation medium, and the seeds placed in the cultivation medium are less likely to penetrate into the pores and fall into the water, which is effective for the germination and growth of the seeds.

In addition, if the sponge-like metal porous body 11 is made of titanium, a titanium alloy, or a cobalt-chromium alloy and the surface is treated with alkali, a plant growth promoting effect may be obtained.

In the embodiments 2 to 6 described below, 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.

(Embodiment 2)
FIG. 2 shows a metal porous cultivation medium 20 and a cultivation container 2 according to the second embodiment, in (A) a perspective view and (B) an a-a cross-sectional view. The metal porous cultivation medium 20 is made of a spongy metal porous body 21 and is housed in the cultivation container 2. A recess 22 is formed on the upper surface of the spongy metal porous body 21. The recess 22 is for holding the seed 1 to be placed and preventing it from being removed from the cultivation medium. That is, if the recess 22 is not formed on the upper surface of the spongy metal porous body 21 and the seed 1 is placed as it is, if 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 will float on the water and be removed from 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 be removed from the cultivation medium. The size and depth of the recess 22 can be appropriately set according to the seed 1 to be placed.

The porous metal cultivation medium 20 according to the second embodiment has a recess 22 for holding the seed 1 on the upper surface of the sponge-like porous metal 21. 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.

(Embodiment 3)
3A is a perspective view showing a porous metal cultivation medium 30 and a cultivation container 3 according to the third embodiment, and FIG. 3B is a cross-sectional view taken along the line b-b. 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 for holding the seeds 1 placed therein and preventing them from falling off the cultivation medium, similar to the recesses 22 in the second embodiment, and have the same effect.

(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 fall 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 fall 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.

The fall 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 mentioned 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 providing the fall prevention parts 23, 33 can reliably prevent this.

As a method for 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 base material impregnation sintering method," the density of the lower part of the recesses 22, 32 of the sponge-like metal porous body 21, 31 is made denser than the surrounding area to form the fall prevention parts 23, 33.

The porous metal cultivation medium 20, 30 has a fall prevention part 23, 33 at the bottom of the recess 22, 32, so that the seeds 1 placed in the recess 22, 32 can be reliably prevented from falling into the pores and into the water.

(Embodiment 5)
5 is a perspective view showing a porous metal cultivation medium 40 and a cultivation container 4 according to embodiment 5. 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 the 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.

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

(Embodiment 6)
6 is a perspective view showing a porous metal cultivation medium 30 and a cultivation container 3 according to embodiment 6. 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 that appears from the cutouts 34, 34.

The cultivation container 3 is a cultivation container that contains a porous metal cultivation medium 30, and has cutouts 34, 34 on the side for removing the porous metal cultivation medium 30, making it easy to clean and transfer the cultivation medium.

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

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-mentioned embodiment, and various other modifications are possible.

For example, the porous metal cultivation medium of the present invention can be used to promote greening and add 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.

REFERENCE SIGNS LIST 1 Seed 2 Cultivation container 3 Cultivation container 4 Cultivation container 5 Plant 6 Root 10 Porous metal cultivation medium 11 Spongy porous metal body 20 Porous metal cultivation medium 21 Spongy porous metal body 22 Recess 23 Fall prevention portion 30 Porous metal cultivation medium 31 Spongy porous metal body 32 Recess 33 Fall prevention portion 34 Notch portion 40 Porous metal cultivation medium 41 Spongy porous metal body

Claims (6)

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. The porous metal cultivation medium according to claim 1, wherein the surface of the sponge-like porous metal body is subjected to an alkali treatment. 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. The porous metal cultivation medium according to claim 3, characterized in that the bottom of the recess has a fall prevention portion. 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. 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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