Method for evaluating permeability of materials

Abstract

To provide a simple and newly established method for evaluating the permeability of materials.SOLUTION: A method for evaluating the permeability of materials according to the present invention is a method for evaluating the degree of permeability with which a water-soluble component passes through a material. The method includes: a preparation step for preparing an evaluation sample, the evaluation sample including a solid water-soluble component, a film-like material, and a waterproof member, in which the solid water-soluble component has a plane in at least a section of the surface, at least a section of the plane of the solid water-soluble component is covered with the film-like material, and the surface of the solid water-soluble component not covered with the film-like material is covered with the waterproof member; and a measurement step, in water processing for keeping the evaluation sample in contact with water, for measuring the volume of the water-soluble component having passed through the film-like material and moved in water.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for evaluating the permeability of a material. [Background technology]

[0002] Various methods have been developed to evaluate the amount of nitrogen leaching from coated granular fertilizers. Known as this type of technology is, for example, the technology described in Patent Document 1. Patent Document 1 describes that 10 coated granular fertilizers were mixed with soil and filled into a container, distilled water was added to the mixture so that the amount was 60% of the maximum water holding capacity of the soil, the mixture was allowed to stand, and then the coated granular fertilizer was collected from the container, the nitrogen components remaining inside the coated granular fertilizer were analyzed, and the elution rate was calculated from the amount of remaining nitrogen components (paragraph 0058 of Patent Document 1, etc.). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-345872 Summary of the Invention [Problem to be solved by the invention]

[0004] In the evaluation method described in Patent Document 1, coated granular fertilizer is used, in which a material is coated on the particle surface using a spray device, and the amount of nitrogen components that remain inside the coated granular fertilizer without flowing into the soil is measured. However, according to the investigations of the present inventors, it has been found that a simple evaluation method that does not use a spraying device or soil has not yet been sufficiently investigated. [Means for solving the problem]

[0005] After further investigation, the inventors found that the water-soluble components separated from the external water of the evaluation sample permeate the material molded into a film, and the degree of permeation of the water-soluble components through the material can be easily evaluated by measuring the amount of water-soluble components that have migrated to the external water. Based on these findings, further research was carried out. First, we found a method to use a solid water-soluble component in the evaluation sample, Secondly, the present inventors discovered a method of using an aqueous solution containing a water-soluble component, which is obtained by dissolving the water-soluble component in water in advance, as an evaluation sample, and thus completed the present invention.

[0006] According to one aspect of the present invention, there is provided the following method for evaluating the permeability of a material. 1. A method for evaluating the permeability of a material for evaluating the degree to which a water-soluble component permeates the material, comprising: a preparation step of preparing the following evaluation samples; The evaluation sample is The water-soluble component in a solid form, the material in a film form, and a waterproof member are included, The solid water-soluble component has a flat surface on at least a part of its surface, At least a part of the plane of the solid water-soluble component is covered with the film-like material, and The waterproofing member covers the surface of the solid water-soluble component that is not covered with the film-like material, a measuring step of measuring the amount of the water-soluble component that has permeated the film-like material and migrated to the water during the water treatment in which the evaluation sample is kept in contact with water; A method for evaluating the permeability of a material, comprising: 2. A method for evaluating the permeability of a material for evaluating the degree to which a water-soluble component permeates the material, comprising: The following evaluation samples were prepared: The evaluation sample is A cylindrical portion and The film-like material is placed on one or both openings of the cylindrical portion; an aqueous solution containing the water-soluble component, the aqueous solution being contained in the cylindrical portion and in contact with the inner surface of the film-like material; a measuring step of measuring the amount of the water-soluble component that has permeated the film-like material and migrated to the water during a water treatment in which the outer surface of the film-like material placed on the evaluation sample is kept in contact with water; A method for evaluating the permeability of a material, comprising: 3. A method for evaluating the permeability of a material according to 1., comprising: The method for evaluating the permeability of a material, wherein the solid water-soluble component is a tablet. 4. A method for evaluating the permeability of a material according to 1. or 3., comprising: The volume of the solid water-soluble component is 15 mm 3 This completes the method for evaluating the permeability of a material. 5. A method for evaluating the permeability of a material according to any one of 1.3.4., comprising: When the volume of the solid water-soluble component is V and the exposed area of ​​the film-like material that can come into contact with water is S, A method for evaluating the permeability of materials where S and V satisfy 0.01≦S / V≦200. 6. A method for evaluating the permeability of a material according to 2., comprising: The method for evaluating the permeability of a material, wherein the concentration of the water-soluble component in the aqueous solution is 0.1 mg / mL or more and 300 mg / mL or less. 7. A method for evaluating the permeability of a material according to 2. or 6., comprising: The method for evaluating the permeability of a material, wherein the evaluation sample comprises a resin plate having a plurality of the cylindrical portions. 8. A method for evaluating the permeability of a material according to any one of 1. to 7., The method for evaluating the permeability of a material, wherein the material is a composite material containing an ionically crosslinkable polymer, an ionically crosslinking agent, and an environmentally degradable resin. 9. A method for evaluating the permeability of a material according to any one of 1. to 8., The method for evaluating the permeability of a material, wherein the water-soluble component is an agriculturally active ingredient. 10. A method for evaluating the permeability of a material according to any one of 1. to 9., The method for evaluating the permeability of a material, wherein the water-soluble component is urea. 11. A method for evaluating the permeability of a material according to any one of 1. to 10., A method for evaluating the permeability of a material, wherein the amount of the water-soluble component is measured by an absorbance method in the measuring step. 12. A method for evaluating the permeability of a material according to any one of 1. to 11., The method for evaluating the permeability of a material, wherein the measuring step is carried out at room temperature or under accelerated conditions in which the water is heated. 13. A method for evaluating the permeability of a material according to any one of 1. to 12., The method for evaluating the permeability of a material, wherein the measuring step is carried out under static conditions or under accelerated conditions in which the water is stirred. [Effects of the Invention]

[0007] According to the present invention, a simple and newly established method for evaluating the permeability of materials is provided. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a schematic cross-sectional view for explaining an evaluation method according to the first embodiment. [Figure 2] FIG. 10 is a schematic cross-sectional view for explaining an evaluation method according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all drawings, similar components are designated by similar reference numerals, and descriptions thereof will be omitted where appropriate. Furthermore, the drawings are schematic diagrams and do not correspond to actual dimensional proportions.

[0010] The method for evaluating the permeability of a material according to this embodiment will be described.

[0011] The method for evaluating the permeability of a material in this embodiment is a technique for evaluating the degree to which water-soluble components permeate a material by measuring the amount of water-soluble components that have been separated from the water outside the evaluation sample and have permeated the material formed into a film and migrated to the water outside. In the evaluation sample during the measurement process, the solid water-soluble component or the aqueous solution containing the water-soluble component is separated from the water by a film-like material or the like. In the first embodiment, an evaluation sample is used in which the solid water-soluble component is separated from the water by a film-like material and a waterproof member. In the second embodiment, an evaluation sample is used in which the aqueous solution containing the water-soluble component is separated from the water by a film-like material and a cylindrical portion (and, if one opening of the cylindrical portion is opened, a gas such as the atmosphere).

[0012] In the first embodiment, factors that affect the degree of permeability of water-soluble components include: (i) when water and / or water vapor penetrates the interior of the material, water swelling occurs, and this water swelling creates a path within the film-like material through which the water-soluble components can migrate to the outside; and (ii) the above-mentioned water swelling causes membrane cracks to form in the film-like material due to volume expansion and increased internal pressure, which become a path through which the water-soluble components can migrate to the outside.

[0013] In the second embodiment, unlike the first embodiment, no membrane cracks are formed due to water swelling, and therefore the element of physical destruction (ii) above is excluded, and the degree of permeation of the water-soluble component is evaluated, which makes it possible to simplify the measurement. Furthermore, in the second embodiment, the time required for the deliquescence and expansion of the solid water-soluble component to occur is not required, and therefore the measurement can be performed more quickly than in the first embodiment.

[0014] (First embodiment) FIG. 1 is a schematic cross-sectional view for explaining the permeability evaluation method of the first embodiment.

[0015] The permeability evaluation method of the first embodiment includes: A preparation step of preparing the following evaluation samples 50; The evaluation sample 50 is The device includes a solid water-soluble component 20, a film-like material 10, and a waterproof member 30, The solid water-soluble component 20 has a flat surface 21 on at least a part of its surface, At least a part of the plane 21 of the solid water-soluble component 20 is covered with the film-like material 10, and The waterproof member 30 covers the surface of the solid water-soluble component 20 that is not covered by the film-like material 10. a measuring step of measuring the amount of water-soluble components that have permeated the film-like material 10 and migrated into the water 60 during the water treatment in which the evaluation sample 50 is kept in contact with the water 60; Includes:

[0016] In the permeability evaluation method of the first embodiment, as shown in Figure 1, an evaluation sample 50 is used in which a solid water-soluble component 20 is encapsulated in a film-like material 10 and a waterproof member 30.When the film-like material 10 is brought into contact with water 60, the amount of water-soluble component that has permeated the film-like material 10 and migrated into the water 60 is measured, making it possible to evaluate the degree of permeation of the water-soluble component through the material.

[0017] The water-soluble component is not particularly limited as long as it contains a component that dissolves in water. The water-soluble components preferably include agriculturally active ingredients such as fertilizer components, pesticide components, plant growth regulators, and antibacterial components. Examples of water-soluble fertilizer components include urea. In addition to agriculturally active ingredients, other water-soluble components may include efficacy ingredients and fragrances used in pharmaceuticals, cosmetics, and foods.

[0018] In the first embodiment, when the evaluation is carried out at room temperature and atmospheric pressure, the water-soluble component used is in a solid state at 20° C. and atmospheric pressure. It is preferable that the water-soluble component that is liquid at room temperature and pressure is used in the permeability evaluation method of the second embodiment described later.

[0019] The solid water-soluble ingredient 20 may be in the form of any type of pill, preferably a tablet, rather than the granules produced by the spray device.

[0020] The solid water-soluble component 20 may be produced, for example, by a molding machine, specifically, by tableting. In this embodiment, the evaluation sample 50 can be easily prepared without using a spray device.

[0021] The lower limit of the volume of the solid water-soluble ingredient 20 per piece is, for example, 15 mm 3 More than 20mm, preferably 3 More than 25mm, preferably 3 This makes it possible to reduce measurement errors. Furthermore, by making the volume of the solid water-soluble component 20 equal to or greater than the above-mentioned lower limit, the expansion of the solid water-soluble component 20 after deliquescence becomes greater, making it easier for a load to be generated on the film-like material 10, thereby accelerating the evaluation speed. On the other hand, the upper limit of the volume of the solid water-soluble component 20 per unit is not particularly limited, but is 2000 mm 3 Below, 1900mm 3 Below, 1800mm 3 The following is also acceptable. In addition, when the urea granules produced using the spraying device are spherical with a diameter of approximately 3 mm, the volume of each urea granule is 14 mm. 3 This becomes:

[0022] The geometric structure of the solid water-soluble component 20 may also be a three-dimensional structure having at least one basal plane, such as a cylinder, a polygonal prism, a cone, a polygonal pyramid, etc. Among these, a cylinder or polygonal prism having two basal planes is preferred, and a cylinder is more preferred.

[0023] In this specification, the flat surface 21 and basal surface of the solid water-soluble component 20 are not limited to being perfectly flat in terms of geometry, but may be approximately flat surfaces that allow for manufacturing dimensional variations, surface irregularities, gently curved surfaces, etc. The gently curved surface of the approximately surface may be any surface that has a radius of curvature that is greater than the radius of curvature of the surface of the particles manufactured by the spraying device, and may, for example, have a radius of curvature of 0.1 mm or more.

[0024] The solid water-soluble component 20 has a flat surface 21 on the surface covered by the film-like material 10, but may or may not have a flat surface on the other surface not covered by the film-like material 10. This allows the flat surface 21 to enhance the adhesion between the solid water-soluble component 20 and the film-like material 10.

[0025] 1, the surface of tablet-shaped solid water-soluble ingredient 20 is composed of upper and lower surfaces facing each other, and side surfaces 23 located between the upper and lower surfaces. At least one of the upper and lower surfaces may be composed of a flat surface 21, and both may be composed of flat surfaces 21.

[0026] The film-like material 10 may be formed on at least one of the upper and lower planes 21 of the solid water-soluble component 20, or may be formed on both the upper and lower planes 21.

[0027] Here, V represents the volume of the solid water-soluble component 20, and S represents the exposed area of ​​the film-like material 10 that can come into contact with water. The exposed surface of the film-like material 10 that can come into contact with water means the exposed surface in the evaluation sample 50 that is not covered by other members such as the film-like material 10 and the waterproof member 30. When the evaluation sample 50 has two or more sheets of the film-like material 10, S is the total value of the exposed areas of the individual sheets.

[0028] S and V may be configured to satisfy 0.01≦S / V≦200. The lower limit of S / V is, for example, 0.01 or more, preferably 0.02 or more, and more preferably 0.03 or more, which relatively increases the exposed surface area of ​​the film-like material 10 and can accelerate the evaluation speed. On the other hand, the upper limit of S / V is, for example, 200 or less, preferably 190 or less, and more preferably 180 or less. When the S / V is equal to or less than the upper limit, the height of the encapsulated solid water-soluble component 20 becomes relatively high, and the degree of measurement can be improved.

[0029] The thickness of each film-like material 10 is, for example, 0.001 mm to 1 mm, preferably 0.005 mm to 0.9 mm, and more preferably 0.01 mm to 0.8 mm. It is preferable that the thickness of the film-like material 10 is uniform at least on the plane 21. On the other hand, since the coating layer formed on the granules by the spraying device generally has uneven thickness, it is necessary to evaluate it using the average value of the measurement results of multiple coated granular fertilizers.

[0030] The film-like material 10 is obtained from the following materials by a known film manufacturing method. For example, a method of forming the material into a film by press molding or a method of applying a solvent in which the material is dissolved onto a substrate to form a film can be used.

[0031] The material may be, for example, a resin alone, a resin-modifying component alone, or a composition containing a resin, preferably a composite material containing a resin and a resin-modifying component, and more preferably a composite material containing an environmentally degradable resin and a resin-modifying component. The resin-modifying component may be a known component, but may also be an ionically crosslinkable polymer or an ionically crosslinking agent, or an ionically crosslinked material formed by the reaction of an ionically crosslinkable polymer with an ionically crosslinking agent. Other examples of the composite material include a composite material containing an ionically crosslinkable polymer, an ionically crosslinking agent, and an environmentally degradable resin, or a composite material containing an ionically crosslinkable material and an environmentally degradable resin.

[0032] Specific examples of environmentally degradable resins include resins derived from petroleum, resins partially derived from biomass, resins derived from natural polymers, etc. These may be contained alone or in any combination of two or more. Examples of resins whose raw material is petroleum include polycaprolactone, poly(caprolactone / butylene succinate), polybutylene succinate, polyethylene terephthalate copolymer, poly(ethylene terephthalate / succinate), poly(butylene adipate / terephthalate), poly(tetramethylene adipate / terephthalate), polyethylene succinate, poly(butylene succinate / carbonate), polyvinyl alcohol, polyglycolic acid, and glycolic acid / caprolactone copolymer. Examples of resins whose raw materials are partially derived from biomass include (polylactic acid / polybutylene succinate) block copolymers, (polylactic acid / polycaprolactone) copolymers, (polylactic acid / polyether) copolymers, polylactic acid blend PBAT, lactic acid / glycolic acid copolymers, biopolybutylene succinate, poly(butylene succinate / adipate), starch blend polyester resins, and poly(butylene terephthalate succinate); polyhydroxyalkanoates such as polyhydroxybutyric acid, polyhydroxyvaleric acid, polyhydroxycaprylic acid, and poly(hydroxybutyrate / hydroxyhexanoate), and polylactic acid. Examples of resins derived from natural polymers include cellulose, cellulose acetate, cellulose ester resin, starch, esterified starch, and chitosan. Among these, it is preferable to contain one or more selected from the group consisting of biodegradable polyesters such as polybutylene succinate, polybutylene succinate adipate, and poly(butylene succinate / adipate), polyvinyl alcohol, and cellulose acetate.

[0033] The ionically crosslinkable polymer preferably contains at least one of the following components (A) and (B). On the other hand, the ionic crosslinker is When the ionically crosslinkable polymer contains the following component (A), it is preferable that it contains one or more selected from the group consisting of the following components (B), (C), and (D): When the ionically crosslinkable polymer contains the following component (B), it preferably contains one or more selected from the group consisting of the following components (A), (C), and (D). (A) a polyanion having a monovalent or divalent or higher anionic group, or a salt containing the polyanion (B) A polycation having a monovalent or divalent or higher cationic group, or a salt containing the polycation (C) Inorganic cations having monovalent or divalent or higher cations, or salts containing one or more of the inorganic cations (D) An anionic monomer having a monovalent or divalent or higher anionic group, or an acid containing such an anionic monomer

[0034] In this specification, the valence in (A), (B), and (D) refers to the valence per ionic functional group (ionically dissociating group) contained in the monomer or polymer. Taking the example of an ionic functional group in the side chain of a polymer (macromolecule), carboxylic acid is monovalent, and dicarboxylic acid (oxalic acid, fumaric acid, etc.) is divalent. Meanwhile, in the case of (C), sodium ions are monovalent, and calcium ions are divalent. To give a specific example, polyacrylic acid polymers are classified as "polyanions having monovalent anionic groups," and alkylphosphonic acid polymers are classified as "polyanions having divalent anionic groups." In addition, in polyacrylic acid or a polymer containing acrylic acid as a component, when acrylic acid forms a calcium salt, it is classified as a "salt containing a polyanion" in which the monovalent anion group forms a salt with a divalent cation. Furthermore, in a polymer containing phosphonic acid as a constituent element, when the phosphonic acid forms a sodium salt, the polymer is classified as a "salt containing a polyanion" in which the divalent anion group forms a salt with a monovalent cation. Basically, a polymer whose main chain has a repeating structural unit α with an anionic group is called a "polyanion" (polymeric anion). On the other hand, a polymer whose main chain has a repeating structural unit β with a cationic group is called a "polycation" (polymeric cation). However, when the main chain of a polymer contains repeating structural units α and β, a polymer whose molecule contains the same or more repeating structural units α than the number of repeating structural units β is called a "polyanion," and conversely, a polymer whose molecule contains more repeating structural units β than the number of repeating structural units α is called a "polycation." A monomer that has an anionic group but does not have a repeating structural unit α having an anionic group is referred to as an "anionic monomer."

[0035] (A) "Polyanion having monovalent or divalent or higher anionic groups" preferably includes one or more polyanions A1 selected from the group consisting of polysaccharides containing at least one of carboxylic acid, sulfonic acid, and phosphoric acid in the molecule, and complex carbohydrates containing polysaccharides. The polyanion A1 preferably includes at least one of carboxylic acid and sulfonic acid.

[0036] As used herein, a monosaccharide is a sugar composed of one type of sugar. Examples of sugars include glucose, mannose, galactose, glucosamine, galactosamine, xylose, sialic acid, glucuronic acid, iduronic acid, fucose, maltose, trehalose, and lactose. In this specification, a polysaccharide is a saccharide formed by glycosidic bonds between two or more monosaccharides. A polysaccharide may be a homopolysaccharide, which has only one type of monosaccharide, or a heteropolysaccharide (sometimes called a complex polysaccharide), which has two or more types of monosaccharides. Furthermore, the polysaccharide may be any polysaccharide as long as it has a sugar chain (main chain) consisting of a repeating structure of structural units derived from monosaccharides, and functional groups may or may not be formed on the side chains of the sugar chain. Examples of functional groups formed on the side chains include polar functional groups such as a carboxyl group, a sulfonic acid group, an amide group, an acetyl group, an acetylamide group, and an amino group. As used herein, a glycoconjugate is a complex in which a polysaccharide is covalently bonded to other biological compounds other than sugars, such as proteins, lipids, peptides, etc. Examples of glycoconjugates include biopolymers such as glycoproteins, proteoglycans, and glycolipids.

[0037] The polysaccharide in the polyanion A1 may include, for example, one or more selected from the group consisting of alginic acid, carboxymethylcellulose, carrageenan, homogalacturonan, and glycosaminoglycan. Furthermore, the complex carbohydrate in the polyanion A1 may contain, for example, one or more selected from the group consisting of hyaluronic acid and chondroitin sulfate.

[0038] In another embodiment, (A) "a polyanion having a monovalent or divalent or higher anionic group" may include one or more polyanions A2 selected from the group consisting of lignosulfonic acid and polyglutamic acid. That is, (A) may include polyanion A1 alone, polyanion A2 alone, or both polyanion A1 and polyanion A2. Furthermore, the salt containing (A) a "polyanion having a monovalent or divalent or higher anionic group" may include a salt of the polyanion with a monovalent cation, i.e., an anionic compound in which an anionic group of the polyanion forms a salt with a monovalent cation, or may include a salt of a polyanion having at least one of polyanion A1 and polyanion A2 with a monovalent cation. (A) The salt containing the polyanion may include, as the monovalent cation, one or more ions selected from the group consisting of sodium ions, potassium ions, ammonium ions, and phosphonium ions.

[0039] (B) "Polycations having monovalent or divalent or higher cationic groups" include, for example, polylysine and chitosan. Furthermore, the salt containing (B) a "polycation having a monovalent or divalent or higher cationic group" may include a salt of the polycation with a monovalent anion, i.e., a cationic compound formed by the cationic group of the polycation and a monovalent anion. The salt containing (B) the polycation may include, as the monovalent anion, one or more ions selected from the group consisting of chloride ions, hydroxide ions, fluoride ions, bromide ions, iodide ions, acetate ions, and nitrate ions.

[0040] The inorganic cation having a monovalent cation may include, for example, one or more selected from the group consisting of sodium ions, potassium ions, and ammonium ions. (C) The inorganic cation having a valence of two or more may include, for example, one or more ions selected from the group consisting of calcium ions, magnesium ions, and aluminum ions. The salt containing one or more of (C) "inorganic cations having a monovalent or divalent or higher cation" may include a salt of one or more of the inorganic cations with a monovalent or divalent or higher inorganic anion, and specifically may include an ionic compound containing (C) an inorganic cation having a monovalent cation and / or (C) a divalent or higher inorganic anion and one or more inorganic anions selected from the group consisting of sulfate ions, chloride ions, hydroxide ions, phosphate ions, carbonate ions, fluoride ions, bromide ions, iodide ions, nitrate ions, and acetate ions.

[0041] (D) The anionic monomer having a monovalent, divalent or higher anionic group may include an anionic monomer having one or more carboxyl groups, or may include an anionic monomer having a carboxylate group. (D) The acid containing an anionic monomer having a monovalent, divalent or higher anionic group may contain an acid in which a proton is bonded to the anionic group of the anionic monomer. (D) Examples of the acid containing the anionic monomer include anionic monomers having one or more carboxyl groups, such as oxalic acid, fumaric acid, ethylenediaminetetraacetic acid (EDTA), citric acid, adipic acid, etc. These may be used alone or in combination of two or more.

[0042] The weight average molecular weight of at least one of component (A) and component (B) may be, for example, 1,000 or more and 10,000,000 or less. The molecular weight of the raw material monomer of component (A), the raw material monomer of component (B), and / or the anionic monomer or acid containing the anionic monomer of component (D) may be, for example, 1 to less than 1,000. In this specification, the weight average molecular weight is a value calculated in terms of polystyrene.

[0043] The composite material may contain other additives such as inorganic fillers, surfactants, sizing agents, hydrophobic substances, functional additives, etc. These may be contained alone or in any combination of two or more.

[0044] The inorganic filler may be any inorganic filler that is poorly soluble or insoluble in water, and may include, for example, one or more selected from the group consisting of silica, talc, magnesium oxide, calcium oxide, alumina, titanium oxide, calcium carbonate, clay, potassium titanate, mica, glass flakes, whiskers, ferrite, iron oxide, zeolite, and magnesium sulfate. Among these, silica, talc, calcium carbonate, clay, mica, etc. are preferred from the viewpoints of price and availability. Examples of surfactants include anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, etc. Among these, anionic surfactants and nonionic surfactants are preferred. Examples of sizing agents include natural sizing agents, synthetic sizing agents, reactive sizing agents, special sizing agents, etc. Among these, natural sizing agents and synthetic sizing agents are preferred. As the hydrophobic substance, waxes, vegetable oils, and the like are used. Examples of waxes include natural waxes such as carnauba wax, beeswax, and rice wax; petroleum waxes such as paraffin wax and microcrystalline wax; and synthetic waxes such as Fischer-Tropsch wax and polyethylene wax. Examples of vegetable oils include palm oil, soybean oil, rapeseed oil, sunflower oil, palm kernel oil, cottonseed oil, peanut oil, olive oil, coconut oil, corn oil, sesame oil, linseed oil, safflower oil, rice oil, and perilla oil. The functional additive is not particularly limited as long as it is used in the coating material of the fertilizer, and examples thereof include fillers other than the above-mentioned inorganic fillers, lubricants, waxes, thickeners, adhesion promoters, surface modifiers, pH adjusters, crosslinking retarders (chelating agents), reinforcing materials, gas barrier agents, magnetic materials, decomposition inhibitors, etc.

[0045] The waterproof member 30 may be made of a material that is impermeable to water or that is difficult for water to permeate. The waterproof member 30 may be made of a known material such as a rubber material or a plastic material, but a rubber material is preferred, and silicone rubber is more preferred.

[0046] The waterproof member 30 covers the area of ​​the surface of the solid water-soluble component 20 that is not covered by the film-like material 10. With this structure, the path along which the water-soluble component permeates from the solid water-soluble component 20 is limited to the film-like material 10, thereby improving the accuracy of measuring the degree of permeation of the water-soluble component.

[0047] 1, the waterproof member 30 may cover at least a part of the side surface 23 or the entire side surface 23 of the solid water-soluble component 20. The waterproof member 30 may also cover a part of the surface, such as the side surface, of the film-like material 10.

[0048] The waterproof member 30 may have a ring structure that covers the entire outer periphery of the side surface 23 of the solid water-soluble component 20, or when using a tablet of the solid water-soluble component 20, it may have a ring structure with a circular inner shape. The waterproofing member 30 may be made up of one member or multiple members. The multiple members that make up the waterproofing member 30 may be fixed to each other by known means.

[0049] In preparing the evaluation sample 50, the evaluation sample 50 is assembled using the above-mentioned film-like material 10, the solid water-soluble component 20, and the waterproof member 30. The evaluation sample 50 of Figure 1 may be assembled, for example, by placing a film-like material 10 on each of the upper and lower surfaces of a tablet-shaped solid water-soluble component 20, and fixing the solid water-soluble component 20 and the film-like material 10 with a waterproof member 30.

[0050] The uniformity of the film thickness can be improved by preparing the film-like material 10 separately from the solid water-soluble component 20. The film-like material 10, the solid water-soluble component 20, and the waterproof member 30 can be fixed together without using a laminate coating method. Furthermore, when a film is formed by applying heat using the laminate coating method, there is generally a risk of the film having uneven thickness, etc. In contrast, by assembling the evaluation sample 50 without applying heat, it is possible to suppress the occurrence of uneven thickness of the film-like material 10 due to heat. Moreover, by adjusting the area where the waterproof member 30 covers the film-like material 10, it is possible to appropriately control the area and position of the exposed surface of the film-like material 10 in the evaluation sample 50. Furthermore, during sustained release of the water-soluble component, it becomes possible to apply a load only to the exposed surface of the film-like material 10, which is expected to improve the accuracy of the evaluation of the sustained release of the water-soluble component.

[0051] In the evaluation sample 50, the flat surface 21 of the solid water-soluble component 20 and the inner surface 13 of the film-like material 10 may be fixed facing each other. It is preferable that the interface between the flat surface 21 and the inner surface 13 before use (before immersion in water 60) has a region where no other components such as adhesives are present. However, it is acceptable that gas such as air and / or a liquid component formed by deliquescing a portion of the solid water-soluble component 20 due to moisture in the air is inevitably present at the interface of the evaluation sample 50 in the preparation process.

[0052] Through the above preparation steps, the evaluation sample 50 can be prepared.

[0053] Next, in the measurement step, the amount of water-soluble components that permeate the film-like material 10 and migrate into the water 60 during the water treatment in which the prepared evaluation sample 50 is kept in contact with the water 60 is measured.

[0054] Although the detailed mechanism is unclear, water vapor permeates the interior of film-like material 10 upon immersion in water, and a portion of solid water-soluble component 20 contained in evaluation sample 50 is converted into an aqueous solution through moisture permeation and deliquescence. It is thought that some of the aqueous water-soluble component then passes through film-like material 10 and moves into water 60 via routes such as those caused by water swelling or membrane cracks formed due to water swelling.

[0055] The method for measuring the amount of the water-soluble component can be selected from known methods depending on the type of water-soluble component, but for example, an absorbance method can be used. Measurement by a non-contact method such as an absorbance method can speed up the evaluation.

[0056] The water 60 is not particularly limited as long as it is an aqueous solvent containing H2O (water molecules), but an aqueous solvent containing ions such as distilled water, or an aqueous solvent not containing ions such as ion-exchanged water or ultrapure water can be used. The ion species and ion concentration can be selected depending on the water environment in which the material is used, but distilled water can generally be used for evaluation.

[0057] The period for which the water treatment is carried out (evaluation period) can be changed depending on the period for which the material is used or the purpose of evaluating changes in the properties of the material in the initial, middle, and final stages, etc. The evaluation period may be set to several hours to several days or several months.

[0058] The method for keeping the evaluation sample 50 in the water 60 during the water treatment is not particularly limited. If the specific gravity of the evaluation sample 50 is greater than the specific gravity of the water 60, the evaluation sample 50 can be kept in the water 60 stored in the container 70. Also, if the evaluation sample 50 is fixed to a predetermined jig, it can be kept in the water 60 by the weight of the jig. A method may be employed in which the film-like material 10 in the evaluation sample 50 does not come into contact with the inner surface of the container 70 when in the water 60 stored in the container 70. A predetermined jig may be used, or the container 70 may be configured so that the width of the inner surface of the container 70 is smaller than the width of the evaluation sample 50.

[0059] The measurement step may be carried out at room temperature, for example, when the temperature of the water 60 is 20°C to 25°C. The measurement step may also be performed under accelerated conditions in which the water 60 is heated. Heating increases the water vapor transmission rate (moisture transmission rate), allowing for rapid evaluation. The liquid temperature of the heated water 60 may be, for example, 26°C to 50°C, 30°C to 45°C, or approximately 35°C.

[0060] The measurement step may be performed under static conditions in which the evaluation sample 50 is left standing in water 60 . The measurement step may also be carried out under accelerated conditions in which the water 60 is stirred. Stirring increases the number of collisions of the exposed surface (film) with water, allowing for rapid evaluation. Known stirring methods can be used, including stirring using a stirrer, stirring blades, or a shaker, or using ultrasonic waves.

[0061] Second Embodiment FIG. 2 is a schematic cross-sectional view for explaining the permeability evaluation method of the second embodiment.

[0062] The permeability evaluation method of the second embodiment includes: The following evaluation samples 80 were prepared: Evaluation sample 80 (the evaluation sample installed on the evaluation device) A cylindrical portion 82; a film-like material 12 placed at one or both openings of the cylindrical portion 82; an aqueous solution 22 containing a water-soluble component, which is contained in a cylindrical portion 82 and is in contact with an inner surface 17 of the film-like material 12; a measuring step of measuring the amount of water-soluble components that have permeated the film-like material 12 and migrated to the water 62 during a water treatment in which the outer surface 15 of the film-like material 12 placed on the evaluation sample 80 is kept in contact with the water 62; Includes.

[0063] In the second embodiment, the time required for the initial moisture permeation and deliquescence of the solid water-soluble component can be omitted, and therefore the evaluation time can be shortened compared to the first embodiment.

[0064] Although the detailed mechanism is unclear, it is thought that when the film-like material 12 swells due to immersion in water, some of the water-soluble components in the aqueous solution 22 containing the water-soluble components pass through the film-like material 12 and move into the water 62 via routes created by the swelling.

[0065] The aqueous solution 22 containing a water-soluble component is an aqueous solution in which at least a water-soluble component is dissolved in water. The concentration of the water-soluble component contained in this aqueous solution is, for example, 0.1 mg / mL or more and 300 mg / mL or less, preferably 0.31 mg / mL or more and 290 mg / mL or less, and more preferably 0.5 mg / mL or more and 280 mg / mL or less. By setting the concentration to the lower limit or more, the stability of the measurement can be improved, and by setting the concentration to the upper limit or less, preparation of the measurement solution, such as dilution, is not required, thereby reducing the burden during measurement.

[0066] In the water treatment, it is sufficient that the outer surface 15 of the film-like material 12 is kept in contact with water 62 and the inner surface 17 of the film-like material 12 is kept in contact with the aqueous solution 22 containing the water-soluble component. 2, at least one end of the evaluation sample 80 may be immersed in water 62 stored in a container 72, and the outer surface 15 of the film-like material 12 may be brought into contact with the water 62. At this time, atmospheric pressure may be utilized to bring the aqueous solution 22 containing the water-soluble component into contact with the inner surface 17 of the film-like material 12, but this method is not limited thereto.

[0067] 2, the film-like material 12 may be fixed to a holder 86 of the evaluation sample 80. The holder 86 may have a ring structure that can be detachably attached to the cylindrical portion .

[0068] The evaluation sample 80 may have one cylindrical portion 82, or may have a plurality of cylindrical portions 82. A film-like material 12 and an aqueous solution 22 containing a water-soluble component can be placed in each of the multiple cylindrical portions 82. The multiple cylindrical portions 82 may be formed of separate members, or may be formed of a single member. That is, the cylindrical portion 82 may include a resin plate having multiple cylindrical portions 82. The resin plate with the plurality of cylindrical portions 82 may be formed by a known resin molding method.

[0069] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations may be adopted. Furthermore, the present invention is not limited to the above-described embodiments, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention. [Example]

[0070] The present invention will be described in detail below with reference to examples, but the present invention is not limited to the descriptions of these examples.

[0071] <Measurement in the permeability evaluation method of the first embodiment> (Manufacturing film-like materials) Sodium alginate (manufactured by Tokyo Chemical Industry Co., Ltd.) as an ionically crosslinkable polymer and aluminum sulfate 14-18 hydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as an ionically crosslinking agent were ground and mixed in a mortar. The resulting mixture was mixed with polybutylene succinate (PBS) as an environmentally degradable resin under heating to obtain a resin composition. The obtained resin composition was molded into a film to produce a film-like material having a thickness of about 100 μm.

[0072] (Preparation of evaluation sample 50 shown in Figure 1) Using a tablet forming machine, solid urea (specific gravity: approximately 1.3) was pressed into tablets with a height of 1 mm, a diameter of 10 mm, and a volume of approximately 78 mm. 3 The mixture was compressed into cylindrical tablets. The film-like material 10 obtained above was punched into a circle having a diameter of 15 mm. The processed film-like material 10 was placed on each of the top and bottom surfaces of a cylindrical tablet (solid water-soluble component 20), and the sides were fixed using ring-shaped silicone rubber (waterproof member 30) to produce an evaluation sample 50.

[0073] (Measurement of the amount of water-soluble components) Standard solutions of known urea concentrations in the range of 1 mg / mL to 12 mg / mL were prepared, and a calibration curve showing the relationship between absorbance and urea concentration was prepared. As shown in FIG. 1, the evaluation sample 50 was immersed in distilled water (water 60) stored in a polypropylene container 70 at room temperature of 25° C. under atmospheric pressure, and subjected to a water treatment. Immediately after the water treatment, the absorbance of the water 60 at a wavelength of 450 nm was measured over time using an absorbance meter, and the urea concentration (the amount of water-soluble components transferred to the water 60) was determined from a calibration curve. As a result, the amount of urea in the urea tablet (the water-soluble component contained in the solid water-soluble component 20) that migrated into the water 60 (urea dissolution rate) could be measured, and from the measured urea dissolution rate, the period (days) until it reached 10% by mass and the period (days) until it reached 80% by mass could be calculated.

[0074] <Measurement in the permeability evaluation method of the second embodiment> (Evaluation sample 80 shown in Figure 2) Aqueous urea solution with a urea concentration of 12 mg / mL was prepared. The film-like material 10 obtained as described above (production of film-like material) was fixed to one opening of a polypropylene cylindrical portion 82, and then the prepared urea water was poured into the other opening of the cylindrical portion 82 to produce an evaluation sample 80.

[0075] (Measurement of the amount of water-soluble components) One side of the above evaluation sample 80 on which the film-like material 10 was placed was immersed in distilled water (water 62) stored in a polypropylene container 72 at room temperature of 25°C and atmospheric pressure, as shown in Figure 2, to perform water treatment. Immediately after the water treatment, the absorbance of the water 62 at a wavelength of 450 nm was measured over time using an absorbance meter, and the urea concentration (the amount of water-soluble components transferred to the water 62) was determined from a calibration curve. As a result, the amount of urea in the urea water (a water-soluble component contained in the aqueous solution 22 containing a water-soluble component) that moved into the water 62 (urea dissolution rate) could be measured, and from the measured urea dissolution rate, the period (days) until it reached 10% by mass and the period (days) until it reached 80% by mass could be calculated.

[0076] Further, in the above (production of film-like material), another film-like material was produced by changing the compounding ratio of the ion-crosslinkable polymer, the ion-crosslinking agent, and the environmentally degradable resin. When the urea elution rate was measured using another film-like material by the permeability evaluation method of the first embodiment or the permeability evaluation method of the second embodiment, differences were confirmed in the time to reach 10% by mass and the time to reach 80% by mass with either method. This demonstrates that the permeability evaluation methods of the first and second embodiments can be used to evaluate the degree to which water-soluble components permeate a material. [Explanation of symbols]

[0077] 10, 12 Film-like materials 11, 15 External surface 13, 17 Inner surface 20 solid water-soluble ingredients 21 plane 23 Side 22 Aqueous solutions containing water-soluble components 30 Waterproofing materials 50 evaluation samples 60, 62 water 70, 72 container 80 Evaluation Samples 82 Cylinder part 86 Holding part

Claims

1. A method for evaluating the permeability of a material for evaluating the degree to which a water-soluble component permeates the material, comprising: a preparation step of preparing the following evaluation samples; The evaluation sample is The water-soluble component in a solid state, the material in a film state, and a waterproof member are included, The solid water-soluble component has a flat surface on at least a part of its surface, At least a part of the plane of the solid water-soluble component is covered with the film-like material, and The waterproof member covers the surface of the solid water-soluble component that is not covered with the film-like material, a measuring step of measuring the amount of the water-soluble component that has permeated the film-like material and migrated to the water during the water treatment in which the evaluation sample is kept in contact with water; A method for evaluating the permeability of a material, comprising:

2. A method for evaluating the permeability of a material for evaluating the degree to which a water-soluble component permeates the material, comprising: The following evaluation samples were prepared: The evaluation sample is A cylindrical portion and The film-like material is placed on one or both openings of the cylindrical portion; an aqueous solution containing the water-soluble component, the aqueous solution being contained in the cylindrical portion and in contact with the inner surface of the film-like material; a measuring step of measuring the amount of the water-soluble component that has permeated the film-like material and migrated to the water during a water treatment in which the outer surface of the film-like material placed on the evaluation sample is kept in contact with water; A method for evaluating the permeability of a material, comprising:

3. The method for evaluating the permeability of a material according to claim 1, The method for evaluating the permeability of a material, wherein the solid water-soluble component is a tablet.

4. The method for evaluating the permeability of a material according to claim 1, The volume of the solid water-soluble component is 15 mm ３ This completes the method for evaluating the permeability of a material.

5. The method for evaluating the permeability of a material according to claim 1, When the volume of the solid water-soluble component is V and the exposed area of ​​the film-like material that can come into contact with water is S, A method for evaluating the permeability of a material, in which S and V satisfy the relationship 0.01≦S / V≦200.

6. The method for evaluating the permeability of a material according to claim 2, The method for evaluating the permeability of a material, wherein the concentration of the water-soluble component in the aqueous solution is 0.1 mg / mL or more and 300 mg / mL or less.

7. The method for evaluating the permeability of a material according to claim 2, The method for evaluating the permeability of a material, wherein the evaluation sample comprises a resin plate having a plurality of the cylindrical portions.

8. 3. A method for evaluating the permeability of a material according to claim 1 or 2, comprising: The method for evaluating the permeability of a material, wherein the material is a composite material containing an ionically crosslinkable polymer, an ionically crosslinking agent, and an environmentally degradable resin.

9. 3. A method for evaluating the permeability of a material according to claim 1 or 2, comprising: The method for evaluating the permeability of a material, wherein the water-soluble component is an agriculturally active ingredient.

10. 3. A method for evaluating the permeability of a material according to claim 1 or 2, comprising: The method for evaluating the permeability of a material, wherein the water-soluble component is urea.

11. 3. A method for evaluating the permeability of a material according to claim 1 or 2, comprising: A method for evaluating the permeability of a material, wherein the amount of the water-soluble component is measured by an absorbance method in the measuring step.

12. 3. A method for evaluating the permeability of a material according to claim 1 or 2, comprising: The method for evaluating the permeability of a material, wherein the measuring step is carried out at room temperature or under accelerated conditions in which the water is heated.

13. 3. A method for evaluating the permeability of a material according to claim 1 or 2, comprising: The method for evaluating the permeability of a material, wherein the measuring step is carried out under static conditions or under accelerated conditions in which the water is stirred.

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