Biodegradable container, seedling pot, and seedling method

Abstract

To enable a biodegradable container suitable for sowing and seedling cultivation to be provided at low cost.SOLUTION: A biodegradable container 1 has a coating film layer 20 composed of a natural paint formed on an outer surface of a container body 10, which is a molded body of a composition containing a plant powder and a natural adhesive component. By including sodium bicarbonate in the composition to form a foam composition, the container body 10 is constituted as a foam. Soil is placed in a seedling pot composed of the biodegradable container 1, seeds are sown, seedlings are cultivated, and then the seedling pot is buried in the ground with the soil and seedling remaining inside, thereby planting the seedling.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a biodegradable container used for sowing seeds and raising seedlings, and a seedling raising method. [Background technology]

[0002] Conventionally, vinyl seedling pots have been the most common containers used for sowing seeds and raising seedlings. Although vinyl seedling pots have the advantage of being reusable, they are difficult to decompose and therefore cannot be planted in a field as is. For this reason, seedlings must always be removed from the pots before planting in a field, which means that the soil around the seedlings' roots is likely to fall off when planting.

[0003] In light of this, a seedling pot has been proposed (Patent Document 1), which is a molded product made by mixing a thermoplastic biodegradable resin with a powder made of the endosperm of ivory palm seeds as raw materials and molding it with a resin molding machine such as an injection molding machine into a pot shape for growing plants. This seedling pot is biodegradable and returns to soil, so seedlings can be planted by burying the seedling pot in soil. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2009-286978 A Summary of the Invention [Problem to be solved by the invention]

[0005] Although Patent Document 1 does not specifically describe thermoplastic biodegradable resins, polylactic acid is known as a thermoplastic biodegradable resin that has been put to practical use for agricultural sheets and the like. However, seedling pots made of polylactic acid are more expensive than vinyl seedling pots, and have not yet become widespread. In addition, the seedling pots described in Patent Document 1 use the endosperm of the seedlings of the ivory palm as a raw material, but the ivory palm is the fruit of a coconut tree that grows wild in South America, and is also not easily available.

[0006] An object of the present invention is to solve these problems and to provide a biodegradable container suitable for sowing seeds and raising seedlings at low cost. [Means for solving the problem]

[0007] The present invention is a biodegradable container in which a coating layer made of natural paint is formed on at least the inner surface of a container body which is a molded body of a composition containing at least plant powder and a natural adhesive component.

[0008] According to the present invention, the plant powder, the natural adhesive component, and the natural paint are all biodegradable materials that are easily and inexpensively available. In addition, since at least the inner surface of the container body is coated with a coating layer made of natural paint, it is possible to reduce the seepage of water into the container body when water is placed in the biodegradable container. In addition, the biodegradable container can be disposed of by burying it in soil, and the components contained in the plant powder, the natural adhesive component, and the natural paint can be used as fertilizer components. Effect of the Invention

[0009] According to the present invention, a biodegradable container suitable for sowing seeds and raising seedlings can be provided at a lower cost than conventionally known polylactic acid seedling pots. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing the external appearance of a biodegradable container 1 in one embodiment of the present invention. [Diagram 2] FIG. 1 is a cross-sectional view showing the internal structure of a biodegradable container 1 in one embodiment of the present invention. [Diagram 3] FIG. 2 is a diagram showing the appearance of a seedling pot 5. [Figure 4] 2 is a cross-sectional view showing the internal structure of the seedling pot 5. FIG. [Diagram 5] 1 is a diagram showing a manufacturing process of the biodegradable container 1. [Figure 6] 1 is an explanatory diagram showing the state in which seedlings grown in seedling pots 5 have been planted in a field. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0012] <Biodegradable container 1> Fig. 1 is a diagram showing the external appearance of a biodegradable container 1 in one embodiment of the present invention. Fig. 2 is a cross-sectional view showing the internal structure of the biodegradable container 1 in one embodiment of the present invention. The biodegradable container 1 has a coating layer 20 made of natural paint formed on the inner surface of a container body 10.

[0013] <Seedling Pot 5> Fig. 3 is a diagram showing the external appearance of the seedling pot 5. Fig. 4 is a cross-sectional view showing the internal structure of the seedling pot 5. The seedling pot 5 is constituted by a container body 10.

[0014] [Container body 10] The container body 10 is a molded body made of a composition containing at least a plant powder and a natural adhesive component.

[0015] [Plant flour] The plant powder is not particularly limited, and examples thereof include dried or non-dried products such as wood chips of coniferous or broad-leaved trees such as cedar, cypress, pine, Japanese larch, lauan, and teak, shavings, sawdust, bamboo, plum seeds, rice, palm, coffee beans after coffee extraction, straw, rice, corncob meal, and tea leaves, which can be crushed as necessary to an appropriate particle size and used.

[0016] Among these, the plant powder is preferably bamboo powder. Since bamboo grows everywhere in Japan and can be a nuisance in some places, it is relatively easy to obtain. Also, bamboo powder contains lactic acid bacteria, and these lactic acid bacteria activate the microorganisms in the soil, making it easier for the container body 10 and the coating layer 20 to decompose. The microorganisms in the soil can then quickly decompose the organic matter into a state that is easy for crops to absorb. Further, after putting soil into the seedling-raising pot 5 made using this plant powder, sowing seeds, and raising seedlings, the seedling-raising pot 5 with the seedlings can be directly buried in the open ground, making it possible to plant the seedlings in the open ground.

[0017] The bamboo powder is produced by using a bamboo crusher. The bamboo crusher crushes the introduced bamboo and pulverizes it by passing it through a mesh. The particle size of the bamboo powder is determined by the size of the mesh, but in this embodiment, those with a size of 5 mm or less are used. Specifically, in this embodiment, the bamboo powder contains various-sized bamboo grains in the range of 0 < X ≤ 5 (mm) when the particle diameter of the bamboo grains is X (mm).

[0018] Note that the size of the mesh may be changed as appropriate. For example, when it is desired to slow down the biodegradation of the biodegradable container 1, a mesh larger than 5 mm may be used. There is no particular limitation on the type of bamboo, but Moso bamboo, true bamboo, light bamboo, etc. are desirable. In this embodiment, bamboo powder of Moso bamboo is applied. Note that bamboo shoots and bamboo bark can also be applied as raw materials for the bamboo powder.

[0019] In addition to bamboo powder, the plant powder is preferably waste or powder processed from waste generated from the process of processing plants exemplified by planer shavings, sawdust, rice straw, coffee beans after coffee extraction, straw, corn cob meal, etc. Since these materials are waste-derived, they are relatively easy to obtain. Also, using these materials in the manufacture of the biodegradable container 1 or the seedling-raising pot 5 also leads to the effective utilization of waste.

[0020] The plant powder may be a mixture of multiple types. For example, if the plant powder is a mixture of bamboo powder and wood powder of cypress or cedar, since cypress and cedar have a bactericidal effect, when the seedling pot 5 is made using this plant powder, it is expected that the pathogenic bacteria contained in the soil in the seedling pot 5 will be reduced, making the seedlings less susceptible to disease.

[0021] [Natural adhesive ingredients] Natural adhesives are adhesives made from natural materials, unlike synthetic adhesives.

[0022] Examples of natural adhesives include glue (glutin, Glutinleim), casein, natural rubber, lacquer, starch and modified starch (e.g., amylopectin and maltodextrin), cellulose esters and / or cellulose ethers (e.g., methylcellulose and acetylcellulose), lignin products (e.g., lignosulfonates, organosolv lignin), and / or rosin (colophonium).

[0023] Among them, the natural adhesive component is preferably glue. Glue is an organic protein made from animal hide (e.g., cowhide) and bones, etc., by heating them together with water, and has the property of changing into a sol (liquid) or gel (solid) depending on the temperature difference. By utilizing this change, glue can instantly bond paper, wood, etc. In this way, glue is a natural material and a biodegradable adhesive.

[0024] Since glue is made by boiling down the oil between the skin and meat of an animal, microorganisms in the soil decompose the glue to become fertilizer. The coating layer on the outer surface is a natural paint, so it can be decomposed by microorganisms. This makes it possible to dispose of the biodegradable container by burying it in the soil, and also makes it possible to promote the fertilization of the organic matter contained in the soil or glue. In other words, if the coating layer is made of a non-biodegradable synthetic resin, there is a risk that the synthetic resin will remain in the soil when the biodegradable container is buried in the soil, and the synthetic resin may become micro-sized over time and have a negative impact on the environment. In contrast, according to this embodiment, since the coating layer is biodegradable, it is possible to provide an environmentally friendly biodegradable container. However, if a container buried in cultivated land remains without being decomposed, there is a concern that the container will attract the interest of harmful animals such as deer and wild boar, causing damage to harmful animals. In addition, if these harmful animals mistakenly ingest a container that has become micro-plastic, the micro-plastics will spread and concentrate in the ecosystem. According to this embodiment, since the entire container including the coating layer is biodegradable, the entire container is decomposed in the soil. This prevents the remaining container from attracting the interest of harmful animals and causing damage to them. This also prevents harmful animals from accidentally ingesting the container that has turned into microplastics, and the resulting diffusion and concentration of microplastics in the ecosystem.

[0025] The mass ratio of the plant powder to the natural adhesive component is not particularly limited, but the mass ratio is preferably in the range of plant powder:natural adhesive component=30:70 to 70:30, more preferably in the range of 40:60 to 60:40, and even more preferably in the range of 45:55 to 55:45. If the proportion of the plant powder is too small, the number of lactic acid bacteria will decrease, which may slow down the biodegradation of the container body 10. On the other hand, if the proportion of the natural adhesive component is too small, the container body 10 may become brittle and may not be able to maintain the container shape.

[0026] [water] A small amount of water is used to knead the mixture of plant powder and natural adhesive components into a clay-like consistency. The amount of water is set appropriately according to the amounts of plant powder and natural adhesive components. If the amount of water is too little, the container body 10 will be easily broken when external pressure is applied to the container body 10, whereas if the amount of water is too much, the container body 10 will be easily distorted when molded. For this reason, it is more preferable that the water content be within the range of (plant powder + natural adhesive components):water = 100:8-12 by weight.

[0027] [Sodium bicarbonate] As will be described in detail later, the biodegradable container 1 is used for applications such as foamed trays for food and beverage pots. Although not essential, in the case of the seedling pot 5 or when the biodegradable container 1 is used as a seedling pot, it is preferable that the raw material composition further contains sodium hydrogen carbonate (baking soda). Since sodium hydrogen carbonate has the property of being decomposed into sodium carbonate, carbon dioxide, and water by heating, by further containing sodium hydrogen carbonate, the composition can be configured as a foaming agent composition that foams by thermal decomposition.

[0028] The content of sodium bicarbonate is not particularly limited as long as it can exert the functions of the plant powder and the natural adhesive component and can make the biodegradable container 1 or the seedling pot 5 into a foam.

[0029] [Other ingredients] The container body 10 is a molded body of a composition containing a plant powder and a natural adhesive component, but the composition may contain other components. For example, a powder of a natural alkaline component material not derived from a plant, such as eggshell or shell, may be contained. Also, a powder made by crushing a plurality of types of natural alkaline component materials, such as eggshell or shell, may be contained. When soil is placed in a seedling pot 5 using such a container body 10, the soil can be kept weakly alkaline, which is preferred by many plants. Also, when powder of eggshell or shell is contained in the plant powder, eggshell, shell, etc., eggshell, shell, etc. are relatively easy to obtain materials, and most of them are derived from waste, so they are relatively easy to obtain. Also, calcium carbonate (slaked lime) may be applied as a material of an alkaline component. Calcium carbonate (slaked lime) is also relatively easy to obtain.

[0030] [Coating layer 20] The coating layer 20 is formed on the outer surface of the container body 10 and is made of natural paint. The coating layer 20 is made of natural paint, so that it can be biodegraded. The coating layer 20 made of natural paint may be formed on the inner surface of the container body 10 that constitutes the seedling pot 5.

[0031] Examples of natural paints include those that contain natural vegetable oils such as sunflower oil, linseed oil, perilla oil, and walnut oil as the main component, those that contain natural waxes of animal or vegetable origin such as beeswax, carnauba wax, and candelilla wax as the main component dissolved in a solvent such as turpentine oil, and those that contain natural resins such as pine resin, dammar, and copal dissolved in a solvent such as turpentine oil, etc. Among these, it is preferable that the natural paint contains linseed oil and / or persimmon tannin.

[0032] [Linseed oil] Linseed oil is a vegetable oil extracted from the seeds of flax, a plant in the cannabis family, and is used as a paint to create a glossy, durable coating. For this reason, linseed oil is ideal for use in products where water must not leak out, such as food foam trays and beverage pots.

[0033] [Persimmon tannin] Persimmon juice is an extract obtained by crushing and squeezing unripe persimmons, then fermenting and ripening it, and has insect repellent, preservative, waterproofing, etc. For this reason, it is desirable to apply it to the seedling pot 5, which can prevent insects from infesting the seedlings.

[0034] [Method for manufacturing biodegradable container 1] Next, a method for manufacturing the biodegradable container 1 will be described. Fig. 5 is a diagram showing the manufacturing process of the biodegradable container 1, and the manufacturing process of the biodegradable container 1 includes a preparation step of preparing raw materials, a kneading step of mixing the raw materials to form a clay-like material, a molding step of molding the clay-like raw materials into a container shape, a first drying step of drying the molded body in the shape of a container, a coating film forming step of forming a coating film layer of a natural paint on the dried molded body, and a second drying step of drying the molded body with the coating film layer formed thereon.

[0035] In the preparation step, raw materials are prepared.

[0036] In the kneading process, the plant powder and the natural adhesive component are mixed, water is added, and the mixture is kneaded while being heated to form a clay-like mixture. After the mixture has become clay-like, it is cooled to a level at which sodium bicarbonate is difficult to thermally decompose, and then sodium bicarbonate is added and further kneaded. The kneading process may be performed using a kneading machine.

[0037] In the molding process, the clay-like raw material is poured into a mold and molded into a container. For example, an injection molding machine is used to fill a female mold with the raw material and press a male mold against the female mold to mold it into a container.

[0038] Alternatively, the container may be manufactured using a 3D printer rather than injection molding.

[0039] In the first drying step, the molded body formed into a container shape is dried. Specifically, the molded body is naturally dried until the baking soda contained in the molded body is decomposed into carbon dioxide and water. As a result, the container body 10 made of a foam is produced.

[0040] In the coating film forming step, a coating film layer made of natural paint is formed on the surface of the molded body that has undergone the first drying step. The coating film layer can be formed by application using a brush, spray application, application in which the molded body is impregnated with the natural paint placed in a container, or the like. In this manner, a coating layer made of natural paint is formed on the container body 10, thereby producing the biodegradable container 1.

[0041] When manufacturing a foamed tray for food, a pot for beverages, etc., it is preferable to apply linseed oil as a natural paint and form a coating layer (coating layer 20) on the entire surface of the molded body that has undergone the first drying process or at least on the inner surface as shown in Fig. 2. This makes it difficult for moisture to seep out from the foamed tray for food, the pot for beverages, etc. into the container body 10 because the coating layer 20 blocks moisture.

[0042] When manufacturing the seedling pot 5, the container body 10 created through the first drying step becomes the seedling pot 5. As a result, the coating layer 20 is not formed, so that after sowing, when the seeds germinate and the roots grow, the seedling pot 5 can be in a state where the roots can grow out at any time.

[0043] In addition, when manufacturing the seedling pot 5, the coating film forming step and the second drying step may be performed on the container body 10 to form the coating film layer 20, as in the case of the above-mentioned food foam tray and beverage pot. In this case, it is preferable to apply persimmon tannin as a natural paint and form a coating film layer on the surface of the molded body that has been subjected to the first drying step. The coating film layer may be formed on the entire surface of the molded body, or may be formed on a part of the surface of the molded body, such as only the outer surface or only the inner surface of the molded body. As a result, the moisture contained in the soil contained in the seedling pot 5 is blocked by the coating film layer 20, making it difficult for the soil to seep out, and the moisture contained in the soil can be maintained. In addition, when forming a coating film layer on a part of the surface of the molded body, it is preferable to form a coating film layer at least on the inner surface of the molded body. As a result, the moisture inside the seedling pot 5 is blocked by the coating film layer 20, making it difficult for the moisture to seep out of the seedling pot 5. In addition, the lactic acid bacteria in the bamboo powder contained in the seedling pot 5 can activate the microorganisms contained in the soil in the pot, and the microorganisms can turn the organic matter contained in the soil into fertilizer so that the seedlings can easily absorb it.

[0044] Here, when forming the coating film layer 20 on the seedling pot 5, it is desirable to be able to control the thickness of the coating film layer 20. For example, when sowing seeds that germinate and grow roots quickly, a coating film layer 20 formed thinly is applied, so that the coating film layer 20 is biodegraded and disappears before the roots grow, and the roots can grow out of the main body when they grow. When sowing seeds that germinate slowly, a coating film layer 20 formed relatively thick is applied, so that the coating film layer 20 is biodegraded and disappears when the roots grow to a certain extent after germination, and the roots can grow out of the main body when they grow.

[0045] [Uses of biodegradable container 1] As described above, the biodegradable container 1 can be used as a foamed tray for food, a pot for beverages, and the like.

[0046] Among them, the biodegradable container 1 is preferably used as a food foam tray. The food foam tray is used as a container for storing food, and the coating layer 20 is formed on the inner surface of the container part. Therefore, when storing food, the seepage of moisture into the container body 10 is reduced. The same applies when used as a beverage pot. The food foam tray after use is biodegraded by burying it in the soil, and the biodegradable container 1 eventually returns to the soil. For example, in the outdoors, food ingredients are served on the food foam tray, and the food foam tray is collected after the meal. Then, by burying the food foam trays together in a predetermined place, the food foam trays are biodegraded together with the organic matter discarded together with the trays. Then, the biodegradable container 1 finally returns to the soil. In addition, since the food foam tray to which the biodegradable container 1 is applied is made of all naturally derived materials, it goes without saying that it can be incinerated.

[0047] [How to use Seedling Pot 5] First, the seedlings are sowed in soil in the seedling pot 5. The soil in the seedling pot 5 is then watered to germinate and grow. After the seedlings have grown, the seedling pot 5 with the soil and seedlings inside is buried in an open field, such as a field, as shown in FIG. 6. This allows the seedlings to be planted in the field. After the seedlings are planted in the field, the seedling pot 5 is biodegraded by microorganisms contained in the soil inside and outside the container, and the roots of the seedlings grow outside the seedling pot 5, allowing them to absorb fertilizer from the soil in the field. The seedling pot 5 can be biodegraded quickly in the soil because the coating layer 20 is not biodegradable. The seedling pot 5 eventually returns to the soil.

[0048] Thus, according to the embodiment of the present invention, the container body 10 constituting the biodegradable container 1 or seedling pot 5 is made of a foam, so that the surface area of ​​the container body 10 is larger than when it is not made of a foam. As a result, the container body 10 made of a foam has a larger area in contact with the soil inside and outside the container compared to when it is not made of a foam. Therefore, the biodegradable container 1 having the container body 10 made of a foam comes into contact with more microorganisms and is biodegraded in a shorter period of time compared to when it is not made of a foam.

[0049] Furthermore, since the container body 10 is made of a foam, it is expected that holes that communicate between the inside and outside of the container will be formed in the container body 10. In addition, when biodegradation progresses, it is expected that the inside and outside of the container will communicate in a shorter period of time than if the container were not made of a foam. These holes make it easier for the roots of the seedlings to come into contact with the soil outside the container before and during biodegradation. Therefore, the biodegradable container 1 equipped with the container body 10 made of a foam further promotes the growth of seedlings.

[0050] Incidentally, when seedlings grown in conventional vinyl seedling pots are to be transplanted to a field, it is necessary to remove the seedlings from the seedling pots with the soil still attached and bury them in the field. This means that there is a risk that the soil on the seedlings will crumble and damage the roots, so care must be taken when handling the seedlings. In contrast, when seedling pots 5 are used, the seedlings can be transplanted to the field by burying the seedlings, including the seedling pots 5, in the field. This makes it easier to handle the seedlings and transplant them to the field.

[0051] The coating layer 20 may be formed on the seedling pot 5, and in this case, the thickness of the coating layer 20 can be appropriately changed according to the seedling raising period of the seedlings. For example, the coating layer 20 may be relatively thick for a long seedling raising period and relatively thin for a short seedling raising period. This allows the coating layer 20 to biodegrade and disappear when the time for transplanting is reached, and the seedling roots can easily grow outside the seedling pot 5 after transplantation.

[0052] Although the embodiment of the present invention has been described above, the embodiment of the present invention is not limited to the above embodiment. For example, the above-mentioned biodegradable container 1 is a single container body, but a plurality of the above-mentioned biodegradable containers 1 may be connected to form an array.

[0053] In the manufacturing method of the biodegradable container 1, the plant powder and the natural adhesive component are mixed, water is added, and the mixture is kneaded while being heated, but it is also possible to add water to the natural adhesive component to produce a liquid, and then mix the liquid with the plant powder. In the first drying step, the mixture is naturally dried and sodium bicarbonate is decomposed into carbon dioxide and water, but in the molding step, heat is applied to the mold to decompose the sodium bicarbonate into carbon dioxide and water, and the container body 10 may be formed as a foam.

[0054] It should be noted that within the scope of the concept of the present invention, a person skilled in the art may come up with various modifications and alterations. It is understood that such modifications and alterations fall within the scope of the present invention. For example, even if a person skilled in the art appropriately adds, deletes, or modifies the design of the above-described embodiment, or adds, omits, or modifies the conditions of a process, these modifications and alterations are included in the scope of the present invention as long as they include the gist of the present invention. EXAMPLES

[0055] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these. There is none.

[0056] First, the bamboo material was put into a bamboo grinder, and the bamboo powder produced by grinding was placed in a plastic bag or the like and naturally fermented for several days by the lactic acid bacteria contained in the bamboo powder. This naturally fermented bamboo powder was used as the raw material. In addition, bamboo powder, glue powder, and water were prepared in a mass ratio of 50:50:10. An appropriate amount of sodium bicarbonate was also prepared.

[0057] Next, the bamboo powder and glue powder were mixed, water was added, and the mixture was kneaded while being heated to form a clay-like mixture. After the mixture had cooled to a temperature at which sodium bicarbonate was difficult to thermally decompose, sodium bicarbonate was added and the mixture was further kneaded.

[0058] Next, the clay-like raw material was placed into a mold and shaped into a container, and the molded body was allowed to dry naturally until the sodium bicarbonate contained in the body was decomposed into carbon dioxide and water.

[0059] Next, a coating layer of natural paint was formed on the surface of the molded body. Persimmon tannin was used as the natural paint. In this way, a coating layer of natural paint was formed on the inner surface of the container body, thereby obtaining a biodegradable container 1 according to the embodiment.

[0060] When the biodegradable container 1 was buried in soil as it was, the biodegradable container 1 was completely biodegraded in 10 to 15 days. Therefore, when the seedlings are raised in the seedling pot 5 on which the coating layer 20 is formed and soil is put, the coating layer 20 is biodegraded at least within 10 to 15 days, and the roots are able to grow out of the seedling pot. Therefore, if the roots reach the coating layer 20 at the point of 10 to 15 days, the roots will grow out of the seedling pot 5 after about 20 days, and it can be known that the time for planting has come. [Explanation of symbols]

[0061] 1 Biodegradable container 10 Container body 20 Coating layer

Claims

1. A biodegradable container, comprising a container body which is a molded body of a composition containing at least a plant powder and a natural adhesive component, and at least the inner surface of which is formed with a coating layer of a natural paint.

2. The biodegradable container according to claim 1, wherein the mass ratio of the plant powder to the natural adhesive component is within a range of plant powder:natural adhesive component=30:70 to 70:

30.

3. The composition is a foaming agent composition further comprising sodium bicarbonate, The biodegradable container according to claim 1 or 2, wherein the container body is a foam made from the foaming agent composition.

4. A seedling pot having a container body which is a molded body of a composition containing at least a plant powder and a natural adhesive component.

5. A seedling raising method comprising filling the seedling raising pot according to claim 4 with soil, sowing seeds in the seedling raising pot to raise the seedlings, and then burying the seedling raising pot with the soil and the seedlings inside in the open ground when planting the seedlings in the open ground.

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