Water supply body and plant cultivation method

Abstract

To provide a water supply body that can be used for a long period of time, and to provide a method for cultivating plants using the water supply body.SOLUTION: Provided is a water supply body comprising a water-permeable bag, a highly water-absorbent resin (hereinafter, component (A)), and an inorganic salt (hereinafter, component (B)), component (A) and component (B) being stored in a mixed state in the bag, the water absorption capacity of component (A) being 100 g / g or more and 800 g / g or less, and the mass ratio (B / A) of the content of component (B) to the content of component (A) being 0.2 or more and 100 or less.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a water supply body and a method for cultivating plants. [Background technology]

[0002] When growing plants at home, regular watering is essential.

[0003] With regard to such watering, for example, it has been proposed to use a horticultural moisturizing bag that can provide good soil moisturizing effects for a long period of time, which is made by sealing a material containing a water-absorbent polymer in a breathable bag body, and is characterized in that at least one side of the bag body is made of a UV-cut sheet that blocks the entry of ultraviolet rays, and the other side is moisture-permeable (Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2009-171849 A Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, the diversification of working styles and other factors have led to an increase in the number of people spending more time at home, and as a result, the number of people growing plants has been on the rise. Plant cultivation involves various issues and problems related to watering, cleaning, insects, etc., but many people are concerned about the hassle of watering and forgetting to water. The moisture-retaining bag in Patent Document 1 requires re-supplying (absorption) of water after several days of use, and in response to the strong demands of plant cultivation in recent years, a water supply unit that can be used for a longer period is required.

[0006] The present invention relates to a water supply body that can be used for a long period of time, and a method for cultivating plants using said water supply body. [Means for solving the problem]

[0007] The present invention relates to the following [1] and [2]. [1] A water supply body comprising a water-permeable bag, a highly water-absorbent resin (hereinafter, component (A)), and an inorganic salt (hereinafter, component (B)), in which the components (A) and (B) are stored in a mixed state in the bag, the water absorption capacity of the component (A) is 100 g / g or more and 800 g / g or less, and the mass ratio (B / A) of the content of the component (B) to the content of the component (A) is 0.2 or more and 100 or less. [2] A method for cultivating plants, comprising the steps of: allowing the water supply body described in [1] to absorb water; and placing the absorbed water supply body with the permeable part of the bag body facing the soil surface to supply water to a plant planted in the soil. Effect of the Invention

[0008] According to the present invention, it is possible to provide a water supply body that can be used for a long period of time, and a method for cultivating plants using said water supply body. [Brief description of the drawings]

[0009] [Figure 1] 1 shows a plan view and a bottom view of embodiment 1 of a water supply body of the present invention. [Diagram 2] 1 shows the configuration of embodiment 1 of the water supply body of the present invention. [Diagram 3] 2 shows the configuration of embodiment 2 of the water supply body of the present invention. [Figure 4] 1 shows the configuration of embodiment 3 of the water supply body of the present invention. [Diagram 5] 1 shows the configuration of embodiment 4 of the water supply body of the present invention. [Figure 6] The configuration of embodiment 5 of the water supply body of the present invention is shown. [Figure 7] 1 shows the configuration of embodiment 6 of the water supply body of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The inventors have studied the above problem and have found that a water supply body that can be used for a long period of time can be obtained by using a mixture containing a superabsorbent polymer with a specific water absorption capacity and an inorganic salt in a specific ratio. Although the mechanism is unclear, when the inorganic salt dissolves, the ion concentration outside the superabsorbent polymer that has swollen due to the supply of water (water absorption) increases, and the water inside the superabsorbent polymer is discharged to the outside to eliminate the ion concentration difference inside and outside the superabsorbent polymer. In the present invention, it is believed that by using a superabsorbent polymer with a specific water absorption capacity and an inorganic salt in a specific ratio, a moderate ion concentration difference occurs inside and outside the superabsorbent polymer, and it is presumed that this allows a large amount of water to be supplied for a long period of time.

[0011] The water supply body of the present invention comprises a water-permeable bag, a superabsorbent polymer (hereinafter, component (A)), and an inorganic salt (hereinafter, component (B)), and the component (A) and the component (B) are stored in a mixed state in the bag. In this specification, the term "water-permeable bag" means a bag that is partially or entirely water-permeable. For example, an embodiment in which a part of the bag is water-permeable and the remaining part is made of a water-impermeable material can be mentioned. Here, the water-permeable part refers to a part through which water can be supplied from the outside to the superabsorbent polymer in the water supply body through the part, and through which water can pass to such an extent that the superabsorbent polymer in the water supply body can release the water held therein to the outside. The water-permeable part can be made of a water-permeable material. The water-permeable part may be a part or the whole of the bag, and in an embodiment in which the water-permeable part is a part of the bag, the water-permeable part may be one or more parts. From the viewpoint of enabling the water held by the superabsorbent resin in the water supply body to be released to the outside, it is preferable that the water-permeable portion at least partially overlaps the position where the mixture of components (A) and (B) is located.

[0012] In this specification, "the (A) component and the (B) component are stored in a mixed state in the bag" means that the (A) component and the (B) component are arranged in a mixed state, such as the distribution range of the (A) component overlapping the distribution range of the (B) component in the bag. Therefore, the (A) component and the (B) component may be stored separately and mixed in the bag, or a mixture of the (A) component and the (B) component may be prepared in advance and stored. In addition, in an embodiment in which a particle containing the (B) component is used as the (B) component, which will be described later, the (A) component and the particle containing the (B) component are in a mixed state. In order to maintain the (A) component and the (B) component in a mixed state in the bag, the (A) component and the (B) component may be fixed to the bag or a sheet enclosed in the bag by using an adhesive or the like.

[0013] The water supply body of the present invention can be used for various applications requiring long-term water supply, and can be suitably used for plant cultivation. Here, in the embodiment used for plant cultivation, the water supply body can be used in a method of placing a water-permeable portion of a bag body having water permeability facing the soil surface to supply water to a plant planted in the soil. In this case, in the embodiment in which the water supply body is in the form of a sheet, it is preferable that the surface opposite to the surface facing the soil surface (the surface having the water-permeable portion) does not have a water-permeable portion from the viewpoint of suppressing a reduction in the amount of water supplied due to evaporation. That is, as in the embodiment 1 described later, it is preferable that the surface opposite to the surface facing the soil surface (the surface having the water-permeable portion) is formed from a water-impermeable material. The method of placing the water supply body may be any method as long as the water released from the water-permeable portion can be supplied to the soil, and in addition to placing it directly on the soil surface, it can also be placed on top of another water supply body.

[0014] The water-permeable material forming the bag body may be any known material, such as nonwoven fabric, woven fabric, etc. Materials include natural fibers such as silk, wool, feathers, cotton, hemp, pulp, etc., and synthetic fibers such as polyolefins such as polyethylene and polypropylene, polyester, polyamide, polyurethane, etc. From the viewpoint of improving heat compression bonding in manufacturing, nonwoven fabrics such as polyethylene fibers, polypropylene fibers, and polyester fibers are preferred.

[0015] The water permeability of the water-permeable material is not particularly limited, but from the viewpoint of improving the water absorption and supply amount, it is preferably 80% or more, more preferably 90% or more, even more preferably 95% or more, and even more preferably 97% or more, and the upper limit can be, for example, 100% or less, 99% or less, etc. The water permeability of the water-permeable material can be measured by the method described in the Examples.

[0016] The water-impermeable material forming the bag may be any known material, such as polyethylene, polypropylene, polyethylene terephthalate, polyethylene naphthalate, polystyrene, polyamide, polyurethane, polyvinyl chloride, polyacrylic acid, cellophane, etc. From the viewpoint of improving heat-compression bonding in manufacturing, polyethylene or polyvinyl chloride is preferred.

[0017] From the viewpoint of allowing the bag to absorb water sufficiently even when the size of the bag is reduced (from the viewpoint of not inhibiting the swelling of the highly water-absorbent resin, which is the component (A)), it is preferable that the water-permeable material or water-impermeable material forming the bag is flexible. The flexural modulus of these materials is preferably 1.5 gf / cm from the viewpoint of improving water absorption. 2 Less than or equal to 1.0 gf / cm 2 Less than 0.5gf / cm, more preferably 0.5gf / cm 2 Less than or equal to 0.35 gf / cm 2 The lower limit is, for example, 0.01 gf / cm 2 More than 0.05gf / cm 2 More than 0.10gf / cm 2The flexural modulus of the water-permeable material or the water-impermeable material can be measured by the method described in the Examples.

[0018] The superabsorbent resin, which is component (A), may be any known material, including partially crosslinked acrylic acid polymers with sodium salts, potassium acrylate-acrylamide copolymers, partially sodium salts of starch-acrylic acid graft polymers, thermally crosslinked carboxymethyl cellulose, etc. Among these, partially crosslinked acrylic acid polymers with sodium salts are preferred because they are easier to maintain the amount of absorbed water within a specific range.

[0019] The water absorption capacity of the (A) component is 100 g / g or more, preferably 200 g / g or more, more preferably 250 g / g or more, even more preferably 270 g / g or more, and even more preferably 300 g / g or more, from the viewpoint of improving the water absorption capacity of the water supply body (hereinafter also simply referred to as the water absorption capacity) and the amount of absorbed water supplied to the outside of the water supply body (hereinafter also simply referred to as the water supply capacity) (hereinafter also simply referred to as the performance). Also, from the viewpoint of ease of production, it is 800 g / g or less, preferably 700 g / g or less, more preferably 600 g / g or less, and even more preferably 500 g / g or less. The water absorption capacity of the (A) component in this specification refers to the water absorption capacity of deionized water based on JIS K7223-1996.

[0020] The ratio of the 5-minute water absorption capacity of the (A) component to the saturated water absorption capacity when immersed in water at 4° dH at 25°C is preferably 0.3 or more, more preferably 0.5 or more, and even more preferably 0.7 or more, with the upper limit being 1.0 or less, from the viewpoint of improving the water absorption and water supply. The saturated water absorption capacity and the 5-minute water absorption capacity are measured by the method described in the examples below. A high 5-minute water absorption capacity is preferable because it shortens the water absorption time of the water supply body and improves convenience during use.

[0021] The superabsorbent resin of component (A) is preferably in the form of particles from the viewpoint of improving the water absorption capacity, and when component (A) is in the form of particles, the average particle size of component (A) is preferably 30 μm or more and 900 μm or less, more preferably 100 μm or more and 500 μm or less, and even more preferably 200 μm or more and 400 μm or less, from the viewpoint of improving the water retention capacity of the water supply body. The average particle size of component (A) is measured by the method described in the Examples below.

[0022] The content of the component (A) in the mixture containing the components (A) and (B) is preferably 0.5% by mass or more, more preferably 1% by mass or more, even more preferably 5% by mass or more, and even more preferably 9% by mass or more from the viewpoint of improving the water retention capacity of the water supply body. Also, from the viewpoint of improving the water supply, the content is preferably 90% by mass or less, more preferably 60% by mass or less, even more preferably 40% by mass or less, and even more preferably 30% by mass or less.

[0023] The inorganic salt of component (B) may be one or more inorganic salts selected from sulfates, phosphates, nitrates, carbonates, and chlorides. The salt of component (B) may be an alkali metal salt such as sodium salt or potassium salt, an alkaline earth metal salt such as calcium salt or magnesium salt, a copper salt, a zinc salt, an iron salt, or an ammonium salt. Preferably, the salt is one or more selected from alkali metal salts, alkaline earth metal salts, and ammonium salts, more preferably one or more selected from sodium salts, potassium salts, calcium salts, and ammonium salts. More preferably, component (B) is one or more selected from potassium sulfate, ammonium sulfate, potassium dihydrogen phosphate, dipotassium monohydrogen phosphate, ammonium nitrate, potassium nitrate, calcium carbonate, sodium chloride, potassium chloride, and calcium chloride.

[0024] The content of the component (B) in the mixture containing the components (A) and (B) is preferably 1% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, still more preferably 30% by mass or more, still more preferably 40% by mass or more, still more preferably 50% by mass or more, and still more preferably 60% by mass or more, from the viewpoint of providing the plant with the necessary amount of water. Also, from the viewpoint of improving the water supply performance, it is preferably 90% by mass or less, more preferably 80% by mass or less, and still more preferably 70% by mass or less.

[0025] The mass ratio (B / A) of the content of the (B) component to the content of the (A) component is, from the viewpoint of providing the plant with the necessary amount of water, from 0.2 to 100, preferably from 0.3 or more, more preferably from 0.5 or more, even more preferably from 1.0 or more, still more preferably from 1.5 or more, still more preferably from 3.0 or more, still more preferably from 5.0 or more, and still more preferably from 6.0 or more, and from the viewpoint of providing the plant with the necessary amount of water, is preferably from 90 or less, more preferably from 80 or less, still more preferably from 50 or less, and still more preferably from 10 or less.

[0026] From the viewpoint of sustained release of the (B) component, the inorganic salt of the (B) component is preferably in a form contained in particles having a coating layer. That is, it is preferable to store the (B) component-containing particles having a coating layer in the bag, and from the same viewpoint, the average particle size of the (B) component-containing particles is preferably 0.1 mm or more and 15 mm or less, more preferably 0.3 mm or more and 10 mm or less, and even more preferably 0.5 mm or more and 5 mm or less. The average particle size of the particles containing the (B) component is measured by the method described in the Examples below.

[0027] Examples of the coating layer in particles containing component (B) include known coating components such as resins such as polyolefin resins (polyethylene, polypropylene, etc.) and sulfur. In addition, particles containing component (B) can further contain clay minerals such as talc, fumed silica, chelating agents, etc. as desired. Examples of particles in which inorganic salts are coated with resins or the like include coated fertilizer particles in which granular fertilizers are coated and encapsulated with resins, wax, or sulfur. Various coating materials and coating methods are disclosed in, for example, JP-B-40-28927, JP-B-44-28457, JP-B-37-15382, JP-B-42-13681, and JP-A-10-156166.

[0028] The mixture containing the components (A) and (B) may optionally contain metal salts other than the component (B), chelating agents, pH adjusters, preservatives, thickeners, ion exchange resins, and the like.

[0029] The water supply body may comprise the above-mentioned water-permeable bag and mixture containing component (A) and component (B), and may further comprise any of absorbent paper, plastic film, nonwoven fabric, etc.

[0030] One embodiment of the water supply body of the present invention will be described below. For example, as shown in Fig. 1, there is an embodiment (embodiment 1) in which the bag body 10 of the water supply body 1 has a permeable portion 10a on only one side. In this embodiment, the water supply body 1 is placed with its bottom surface (the surface having the permeable portion 10a) facing the soil surface, so that water can be supplied to the soil from the permeable portion 10a, and water evaporation from the upper surface can be suppressed by the water-impermeable film 11B.

[0031] In the first embodiment, as shown in FIG. 2, the outer periphery of the water-impermeable films 11A and 11B is sealed, and the water-permeable nonwoven fabric 12A is placed in the center of the rectangular cut-out film 11A to form a bag 10 having a water-permeable portion 10a. The water supply body 1 can be produced by placing a mixture 20 containing the (A) component and the (B) component (hereinafter simply referred to as the mixture 20) in the bag 10. Here, the mixture 20 is preferably placed in a position overlapping the water-permeable portion 10a as shown in FIG. 2. The mixture 20 may be fixed to the water-impermeable film 11B by using an adhesive, if desired. Examples of the adhesive include hot melt, water-based adhesive, and solvent-based adhesive. The same applies to the following embodiments 2 to 6.

[0032] In a sheet-like water supply body such as embodiment 1, the proportion of the water-permeable portion 10a, when the area of ​​one side of the bag is taken as 100 area%, is preferably 0.5 area% or more, more preferably 10 area% or more, even more preferably 15 area% or more, still more preferably 18 area% or more, and preferably 100 area% or less, more preferably 80 area% or less, still more preferably 50 area% or less, still more preferably 30 area% or less, and still more preferably 25 area% or less. From the viewpoint of improving water supply, the ratio of the content of component (A) to the area of ​​one side of the bag is preferably 0.0150 g / cm. 2 Less than 0.0100 g / cm 2 More preferably, 0.0080 g / cm 2 More preferably, 0.0070 g / cm 2 More preferably, 0.0060 g / cm 2 More preferably, 0.0050 g / cm 2 and preferably 0.0001 g / cm 2 More preferably, 0.0010 g / cm 2 More preferably, 0.0020 g / cm 2 The same applies to the following aspects 2 and 3.

[0033] As another example, as shown in FIG. 3, a second embodiment is one in which a water-permeable nonwoven fabric 12B is also disposed on the surface of a water-impermeable material 11B.

[0034] As another example, as shown in FIG. 4, an embodiment 3 is an embodiment in which a water-permeable nonwoven fabric is not arranged, and a water-impermeable material 11C having holes formed therein that are large enough to prevent the mixture 20 from passing therethrough is used.

[0035] As a fourth embodiment, as shown in FIG. 5, a water-permeable nonwoven fabric 12A is used on the entire surface of one side.

[0036] Moreover, as a fifth embodiment, as shown in FIG. 6, there is illustrated an embodiment in which water-permeable nonwoven fabrics 12A and 12B are used on the entire surface.

[0037] As a sixth embodiment, as shown in FIG. 7, a substantially spherical water-permeable bag body 12C having no surface is used.

[0038] Next, a method of using the water supply body of the present invention will be described using an example in which the water supply body of the above-mentioned embodiment 1 is used. First, the water supply body 1 is immersed in water for 5 minutes to absorb water. The water-absorbed water supply body 1 is placed in a pot in which a plant is growing, with the bottom surface of the water supply body 1, i.e., the surface having the water-permeable portion 10a, facing the soil, and the plant is cultivated. It is not necessary to supply water to the plant for about one month after starting to use the water supply body.

[0039] Thus, the water supply body of the present invention can be used for a long period of time after the first water absorption without needing to absorb water again, and can be used for various purposes requiring long-term water supply. Therefore, the present invention provides a water supply method using the water supply body of the present invention, and in particular, a plant cultivation method including a step of making the water supply body of the present invention absorb water, and a step of placing the absorbed water supply body with the water-permeable part of the water-permeable bag body facing the soil surface to supply water to plants planted in the soil. Here, the method of placing the water supply body may be any method as long as the water released from the water-permeable part can be supplied to the soil, and it may be placed directly on the soil surface or may be placed on top of another water supply body.

[0040] The present invention further discloses the following water supply body.

[0041] <1> A water supply body comprising a water-permeable bag, a highly water-absorbent resin (hereinafter, component (A)), and an inorganic salt (hereinafter, component (B)), the component (A) and the component (B) being stored in a mixed state in the bag, and the bag has a flexural modulus of 0.01 gf / cm 2 More than 1.5gf / cm 2 A water supply body made of the following water-permeable and / or water-impermeable materials. <2> <1> A method for cultivating plants, comprising the steps of: absorbing water into the water supply body described in claim 1; and placing the absorbed water supply body with the permeable part of the bag body facing the soil surface to supply water to a plant planted in the soil. <1> and <2> In the above, the preferred embodiment is as described above. EXAMPLES

[0042] The present invention will be specifically described below with reference to examples. Note that the following examples are merely illustrative of the present invention and do not imply any limitations. Note that "normal pressure" refers to 101.3 kPa, and "normal temperature" refers to 25°C. Water hardness is calculated by converting the amount (mg) of calcium and magnesium contained in 1 liter of water into the amount of calcium oxide (CaO), with 10 mg / L being 1° dH water.

[0043] Preparation of water supply body Examples 1 to 10, Comparative Examples 1 to 2 A water supply body 1 having the configuration shown in Figures 1 and 2 was produced. As the water-impermeable films 11A and 11B, polyethylene films (Artec Co., Ltd., LLDPE film, thickness 30 μm, bending modulus 0.19 gf / cm 2), and Elves S0263WE (manufactured by Unitika Ltd., water permeability 97.6%) were used as the water-permeable nonwoven fabric 12A. The mixture 20 containing the (A) component and the (B) component was prepared by mixing them in the amounts shown in Tables 1 to 5. Here, the blending amount of the (A) component was prepared in an amount that would absorb 40 g of water in 5 minutes. The water absorption amounts shown in Tables 1 to 5 are amounts when eight water supply bodies were used. The (B) component was prepared using particles containing the (B) component and having a coating layer (hereinafter, coated (B) particles). The size of the water supply body 1 was 6 cm x 8 cm, the water-permeable portion 10a was 20 mm x 20 mm, and the outer periphery 10b was heat-pressed with a width of 2 mm.

[0044] Examples 11 and 12 Except for using the shape of the water supply body shown in Table 5, the preparation was carried out in the same manner as in Example 8, including the blending amount of component (A).

[0045] Details of the components used in Tables 1 to 5 are shown below. <Component (A)> A(1): Sodium polyacrylate; deionized water absorption based on JIS K7223-1996: 418g / g, average particle size: 248μm, 5 minutes water absorption / saturation water absorption: 0.81 A(2): Sodium polyacrylate; deionized water absorption based on JIS K7223-1996: 378g / g, average particle size: 320μm, 5 minutes water absorption / saturation water absorption: 0.72 A(3): Sodium polyacrylate; deionized water absorption based on JIS K7223-1996: 184g / g, average particle size: 260μm, 5-minute water absorption / saturation water absorption: 0.65 Incidentally, the sodium polyacrylates A(1) to A(3) were all acrylic acid polymers partially cross-linked with sodium salt. <Coated (B) particles> B(1): Micro Long Total 280-100 (manufactured by JCAM AGRI Co., Ltd., coated fertilizer, average particle size 1 mm, 100 days or less type, inorganic salt content 77% by mass, nitrogen: phosphorus: potassium = 12% by mass: 8% by mass: 10% by mass) B(2): Super Ecolong 413-100 (manufactured by JCAM AGRI Co., Ltd., coated fertilizer, average particle size 3 mm, 100 days or less type, inorganic salt content 85% by mass, nitrogen:phosphorus:potassium = 14% by mass:11% by mass:13% by mass)

[0046] <Method for measuring the (B) component in coated (B) particles> 1 g of the coated (B) particles was immersed in 100 ml of ion-exchanged water and left to stand at 50°C for 3 days, after which the coated (B) particles were ground in a mortar, stirred, and filtered. The residue was dried and weighed, and the weight of the (B) component was calculated using the following formula. Weight of component (B) (g) = amount solubilized in ion-exchanged water (g) = initial weight of coated (B) particles (g) - weight of dried residue (g)

[0047] <Method for measuring water permeability of water-permeable nonwoven fabric> A 20cm x 20cm water-permeable nonwoven fabric was placed on top of a 300ml plastic cup and secured with a rubber band, and 100ml of water was poured from above and the amount of water that had permeated into the plastic cup was measured after 1 minute. The water permeability was calculated from the amount of water that had permeated relative to the amount of water poured from above (100ml).

[0048] <Method for measuring the bending modulus of water-impermeable film> The bending modulus was measured using a pure bending tester (KES-FB2-S, manufactured by Kato Tech Co., Ltd.) at 20°C and 65% relative humidity. A 50 mm × 70 mm piece of material was used, with a torque sensitivity of 20 gf cm and a curvature of +2 cm. -1 The measured values ​​were used.

[0049] <Water absorption capacity of component (A)> The water absorption of component (A) was measured in accordance with JIS K7223-1996.

[0050] <5-minute water absorption rate compared to saturated water absorption rate when immersed in 4°dH water> A nylon mesh (255 mesh) was cut into a size of 40 x 10 cm. The long side of the cut nylon mesh was folded in half, and the two sides were heat-pressed to create a bag. Component (A) was sieved through a sieve with a mesh size of 75 μm. 0.2 g of component (A) remaining on the sieve was placed in the nylon mesh bag created above. It was then immersed in 300 mL of 4° dH water for 3 hours. After 3 hours, the nylon mesh bag was hung with the bottom tilted for 10 minutes to drain, and the weight including the nylon mesh bag was measured. The saturated water supply ratio (g / g) was calculated using the following formula. Saturated water absorption capacity=(bca) / a a: weight of sample (g) b: Mass (g) of nylon mesh containing the sample after soaking for a specified time and draining c: Mass (g) of nylon mesh without sample after soaking for a specified time and draining The same procedure was repeated for an immersion time of 5 minutes, and the 5-minute water absorption capacity was determined. The saturated water absorption capacity was calculated based on the 5-minute water absorption capacity.

[0051] <Average particle size> Average particle size of component (A) Sieves with mesh sizes of (i) 1000 μm, (ii) 500 μm, (iii) 300 μm, (iv) 180 μm, (v) 100 μm, and (vi) 53 μm, a tray, and a lid were prepared (manufactured by Sanpo Co., Ltd.). The prepared sieves were stacked from top to bottom in descending order of mesh size, and a tray was placed at the bottom. 10 g of sample was placed in the topmost sieve and the lid was placed. After sieving for 10 minutes, the weight of the sample remaining on each sieve was measured and the ratio to the amount of sample initially placed was calculated. The measurement was performed at 25°C, and the sieves were shaken by hand for 10 minutes. Representative particle diameters of the particles remaining on each sieve were (i) 1000 μm, (ii) 500 μm, (iii) 300 μm, (iv) 180 μm, (v) 100 μm, and (vi) 53 μm, and the average particle diameter of the samples was calculated from the proportion of the samples remaining on each sieve ((sieve opening × sum of mass% of the samples remaining on each sieve) / 100). For example, in the case of A(1), it was calculated as follows: (1000μm×0.1+500μm×3.5+300μm×52.2+180μm×35.4+100μm×8.7+53μm×0.1) / 100=248μm

[0052] Average particle size of coated (B) particles The measurements were made in the same manner as for component (A), except that sieves (manufactured by Sanpo Co., Ltd.) with mesh sizes of 3350 μm, 2000 μm, 1000 μm, 500 μm, 300 μm, 180 μm, 100 μm, and 53 μm were used.

[0053] <1 month wastewater volume> The water supply body was immersed in 300 ml of 4° dH water for 5 minutes. After immersion, the opening of the polyethylene film (the surface having the water-permeable portion 10a) was turned down and drained for 10 minutes. A 3 x 3 cm hole was opened in the bottom of a 9 cm diameter polypot. The bag was placed so that the opening of the polyethylene film of the water supply body overlapped with the hole in the bottom of the polypot. The polypot was fixed with a clip to the 300 ml polycup whose empty weight was measured. The 300 ml polycup was covered with plastic wrap and left to stand for one month. After one month, the weight of the liquid that had fallen into the 300 ml polycup was measured. The results are shown in Tables 1 to 5. The amount of drainage shown in Tables 1 to 5 is the amount when eight water supplies were used.

[0054] <Plant cultivation> Using the water supply bodies of Examples 1 and 9 and Comparative Example 1, plants were actually cultivated, and the condition of the plants after use was evaluated. Eight water supply bodies were immersed in 1000 ml of 4° dH water for 5 minutes. After immersion, eight water supply bodies were placed on a pot in which a Monstera was planted. A No. 5 pot was used. The plants were cultivated in a glass greenhouse at 25°C. No water was given to the Monstera during the cultivation period. After one month, the condition of the plants was evaluated from the appearance. Three pots were used for each test example, and the average value was used as the evaluation result.

[0055] <Condition of plants after use> The condition of the plants was evaluated visually. The scores are as follows, with 5 points being a very good state of plant growth and 1 point being a state where the above-ground part of the Monstera is completely wilted. The results are shown in Table 6. The higher the score, the more effective the water supply unit is. (Evaluation Criteria) Compared to plants that were watered once a week, 5 points: The growth condition was very good. 4 points: The growth condition was good. 3 points: The growth conditions were equal. 2 points: Some leaves were wilted. Score 1: Above-ground parts were completely wilted. In addition, a score of 3 or more was considered acceptable in terms of plant appearance.

[0056] [Table 1]

[0057] [Table 2]

[0058] [Table 3]

[0059] [Table 4]

[0060] [Table 5]

[0061] [Table 6]

[0062] From Tables 1 to 5, Examples 1 to 12, which used the (A) component and the (B) component in a specific ratio, all had excellent drainage amounts over one month, and as shown in Table 6, the condition of the plants after use was also good. In other words, it can be seen that plants could actually be cultivated by using the water supply body of the present invention. On the other hand, in Comparative Example 1, which had a low content of the (B) component relative to the (A) component, and Comparative Example 2, which did not contain the (B) component, the drainage amounts over one month were low, and as shown in Table 6, the condition of the plants after use was not good. [Industrial Applicability]

[0063] The water supply body of the present invention can be used for various purposes where long-term water supply is required, such as plant cultivation. [Explanation of symbols]

[0064] 1 Water supply body 10 Bag body 10a Permeable area 10b Outer periphery 11A Water-impermeable film 11B Water-impermeable film 11C Water-impermeable film 12A Water-permeable non-woven fabric 12B Water-permeable nonwoven fabric 12C Water-permeable nonwoven fabric 20 Mixture containing component (A) and component (B)

Claims

1. A water-absorbing body comprising a water-permeable bag, a superabsorbent polymer (hereinafter referred to as component (A)), and an inorganic salt (hereinafter referred to as component (B)), wherein component (A) and component (B) are stored in a mixed state within the bag, the water absorption capacity of component (A) is 100 g / g or more and 800 g / g or less, and the mass ratio of the content of component (B) to the content of component (A) (B / A) is 0.2 or more and 100 or less.

2. The water supply body according to claim 1, wherein the ratio of the water absorption rate of component (A) at 25°C to the water absorption rate at 4°dH when immersed in water is 0.3 or more after 5 minutes.

3. The water supply body according to claim 1, wherein component (A) is a particle with an average particle size of 30 μm or more and 900 μm or less.

4. The water supply body according to claim 1, wherein component (B) is contained in particles having a coating layer, and the average particle size of the particles is 0.1 mm or more and 15 mm or less.

5. A method for cultivating plants, comprising the steps of: allowing a water-absorbing body according to any one of claims 1 to 4 to absorb water; and placing the water-absorbing body with the permeable portion of the bag facing the soil surface to supply water to plants planted in the soil.

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