Layer-forming material, coated structure, and method for manufacturing coated structure

Abstract

A layer-forming material that is excellent in controlling sustained release is provided. [Solution] The layer-forming material of the present invention comprises an ionically crosslinkable polymer, an ionically crosslinking agent, an environmentally degradable resin, and an inorganic filler, wherein the inorganic filler comprises an anisotropically shaped inorganic filler P1 and a spherical or amorphous inorganic filler Q1.

Description

[Technical Field]

[0001] The present invention relates to a layer-forming material, a coated structure, and a method for producing the coated structure. [Background technology]

[0002] Various developments have been made with regard to layer-forming materials. Patent Document 1, for example, describes a coated granular fertilizer having a structure in which a blend layer made of a blend of different resins, a biodegradable polyester and a polyolefin (thermoplastic resin), is coated with a protective layer containing a polyolefin containing one or more substances that promote the oxidative decomposition reaction of polymers. Furthermore, paragraph 0024 of Patent Document 1 lists talc, clay, diatomaceous earth, silica, calcium carbonate, zeolite, metal oxide, or sulfur powder as inorganic fillers contained in each layer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 09-194280 Summary of the Invention [Problem to be solved by the invention]

[0004] However, as a result of investigations by the present inventors, it has been found that there is room for improvement in terms of sustained release control in the layer containing an inorganic filler as described in Patent Document 1 above. [Means for solving the problem]

[0005] As a result of further investigation, the present inventors have found that the sustained release properties of the layer can be controlled by using two or more different inorganic fillers in combination. Based on these findings, further research was carried out. (i) the use of an anisotropically shaped inorganic filler P1 in combination with a spherical or irregularly shaped inorganic filler Q1, and / or (ii) By using two inorganic fillers P2 and Q2 with different particle sizes in combination, The inventors have found that the sustained release can be controlled so as to reduce the sustained release rate of a substance passing through the layer, and have thus completed the present invention.

[0006] According to one aspect of the present invention, there are provided the following layer-forming material, coating structure, and method for manufacturing the coating structure.

[0007] Below, examples of reference forms are added. 1. An ionically crosslinkable polymer, an ionically crosslinking agent, an environmentally degradable resin, and an inorganic filler, The inorganic filler includes an anisotropic shaped inorganic filler P1 and a spherical or irregular shaped inorganic filler Q1. Layer forming material. 2. The layer-forming material according to 1., The layer-forming material, wherein the anisotropic inorganic filler P1 has a shape that includes at least one of a plate shape, a flat shape, and a fiber shape. 3. The layer-forming material according to 1. or 2., The layer-forming material, wherein the anisotropically shaped inorganic filler P1 has an aspect ratio of 2 or more. 4. An ionically crosslinkable polymer, an ionically crosslinking agent, an environmentally degradable resin, and an inorganic filler, The inorganic filler includes an inorganic filler P2 and an inorganic filler Q2 having an average particle size smaller than the average particle size of the inorganic filler P2. Layer forming material. 5. The layer-forming material according to 4., The layer-forming material, wherein the ratio of the average particle size of the inorganic filler P2 to the average particle size of the inorganic filler Q2 is 1.1 or more and 5,000 or less. 6. The layer-forming material according to any one of 1. to 5., The layer-forming material, wherein the inorganic filler comprises 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. 7. The layer-forming material according to any one of 1. to 6., The ionically crosslinkable polymer contains at least one of the following components (A) and (B): When the ionically crosslinkable polymer contains the following component (A), the ionically crosslinking agent contains one or more selected from the group consisting of the following components (B), (C), and (D), A layer-forming material, wherein when the ionically crosslinkable polymer contains the following component (B), the ionically crosslinking agent 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 8. The layer-forming material according to any one of 1. to 7., A layer-forming material used to form a coating layer on the surface of an object to be coated. 9. The layer-forming material according to 8., A layer-forming material, wherein the object to be coated comprises an agriculturally active ingredient. 10. The object to be covered; a coating layer that covers at least a portion of the surface of the coating object, A coated structure, wherein the coating layer comprises the layer-forming material according to any one of 1. to 9. 11. A method for producing a coated structure, comprising the step of forming a coating layer on the surface of an object to be coated using the layer-forming material according to any one of 1. to 9. [Effects of the Invention]

[0008] According to the present invention, a layer-forming material, a coated structure, and a method for producing a coated structure that are excellent in controlling sustained release properties are provided. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of the configuration of an apparatus for evaluating sustained release properties. DETAILED DESCRIPTION OF THE INVENTION

[0010] An outline of the layer-forming materials of this embodiment will be described.

[0011] The layer-forming material of this embodiment contains an ionically crosslinkable polymer, an ionically crosslinking agent, an environmentally degradable resin, and an inorganic filler.

[0012] The layer-forming material of the first embodiment is The inorganic filler contains at least an anisotropic shaped inorganic filler P1 and a spherical or amorphous inorganic filler Q1.

[0013] The layer-forming material of the second embodiment is The inorganic filler contains at least an inorganic filler P2 and an inorganic filler Q2 having a particle size smaller than that of the inorganic filler P2.

[0014] According to the findings of the present inventors, As in the first embodiment, by using anisotropically shaped inorganic filler P1 in combination with spherical or amorphous inorganic filler Q1, the amount of layer-passing substance released initially or after a predetermined period of time can be kept low in a layer containing two or more inorganic fillers of different shapes. Furthermore, as in the second embodiment, by using two types of inorganic fillers P2 and Q2 with different particle diameter sizes in combination, in a layer containing two or more types of inorganic fillers with relatively large and small particles, the amount of layer-passing substance released at an initial stage or after a predetermined period of time can be kept low. Although the detailed mechanism is unclear, by using two or more inorganic fillers with different shapes and / or particle sizes in combination, the packing ability of the inorganic fillers as a whole can be increased, and it is thought that the release can be controlled so that the release rate of the substance passing through the layer is reduced, for example, by extending the elution period of the encapsulated substance due to the shielding effect of water vapor, etc.

[0015] The layer-forming material of the present embodiment is used to form a layer structure, and is preferably used as, for example, a coating material or a film material.

[0016] The layer-forming material can be used as a coating material to form a coating layer on the surface of an object to be coated. An example of a coating layer is one that can be used to form a resin shell structure that encapsulates one or more objects to be coated. The coating layer can also form resin particles having a hollow structure that includes an inner layer and an outer layer.

[0017] The object to be coated is preferably an object containing an agriculturally active ingredient, but is not limited thereto, and may contain other water-soluble ingredients, such as active ingredients used in pharmaceuticals, cosmetics, foods, etc. The agriculturally active ingredient may be any substance used to grow, promote, or protect agricultural crops, and examples thereof include fertilizer ingredients and pesticide ingredients. The coating target may also include fragrances, pigments, etc. Examples of fragrances include synthetic fragrances, natural essential oils, natural fragrances, animal and plant extracts, etc. Examples of pigments include those used in paints or inks. Furthermore, the object to be covered may be air or a gas other than air that has heat insulating properties. These may be contained alone or in any combination of two or more.

[0018] The coating layer can gradually release the coated substance, such as the water-soluble component described above, to the outside, and can adjust the permeability of water, air, and / or carbon dioxide to the inside according to the requirements of the coated substance.

[0019] Each component of the layer-forming material of this embodiment will be described in detail below.

[0020] The environmentally degradable resin may contain one or more of the same and / or different types of environmentally degradable resins.

[0021] Environmentally degradable resins can be any resin that is decomposed by the action of natural microorganisms such as bacteria, and partially or entirely becomes water, carbon dioxide, etc., and circulates back into nature. Materials that comply with biodegradability tests in accordance with ISO 14855-2 (JIS K 6953-2) are preferred. The environmentally degradable resin may be any known resin.

[0022] Specific examples of environmentally degradable resins include biodegradable plastics, such as polyester resins such as aliphatic polyester resins, aromatic aliphatic polyester resins, and polyhydroxyalkanol (PHA) resins, and non-polyester resins such as natural polymers. These may be used alone or in combination of two or more. The aliphatic polyester resin, aromatic aliphatic polyester resin, and PHA resin may each be partially or entirely derived from biomass or petroleum. The environmentally degradable resin may contain either a biomass-derived resin, a biomass-derived resin, or a natural polymer alone, or may contain two or more of these, for example, a biomass-derived resin and a petroleum-derived resin. The aliphatic polyester resin may contain one or more of, for example, polylactic acid (PLA), polybutylene succinate (PBS), polyhydroxybutyrate, polycaprolactone (PCL), polybutylene succinate / adipate (PBSA), polybutylene adipate terephthalate (PBAT), polyethylene succinate, polyethylene terephthalate succinate (PETS), polymalic acid, polyglycolic acid (PGA), polydioxanone, poly(2-oxetanone), etc. The aliphatic polyester resin may contain these alone or may contain a copolymer containing two or more of these. The aromatic aliphatic polyester resin is a polyester resin having both an aromatic moiety and an aliphatic moiety, and may include, for example, one or more of polybutylene succinate / terephthalate (PBST), polybutylene adipate / terephthalate (PBAT), polytetramethylene adipate / terephthalate, polyethylene adipate terephthalate (PEAT), and the like. The PHA-based resin may include, for example, a P3HB-based resin containing polyhydroxyalkanoate and / or 3-hydroxybutyrate units. The P3HB-based resin may be a polymer containing only 3-hydroxybutyrate units, or may be a copolymer containing repeating units other than 3-hydroxybutyrate units. Specific examples of P3HB-based resins include poly3-hydroxybutyrate (PHB), poly(3-hydroxybutyrate / 3-hydroxyvalerate) (PHBV), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHB3HV), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH), poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P3HB4HB), and poly(3-hydroxybutyrate-co-4-hydroxybutyrate). The poly(3-hydroxybutyrate-co-3-hydroxyoctanoate) (PHB4HB), poly(3-hydroxybutyrate-co-3-hydroxyoctadecanoate) (PHB3HO), poly(3-hydroxybutyrate-co-3-hydroxyoctadecanoate) (PHB3HOD), poly(3-hydroxybutyrate-co-3-hydroxydecanoate) (PHB3HD), poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate) (PHB3HV3HH), and the like may be contained in one or more thereof. The natural polymer may include, for example, one or more of starch, cellulose, cellulose acetate, cellulose ester resin, starch, esterified starch, chitin, chitosan, gluten, gelatin, zein, soy protein, collagen, keratin, and the like. Without being limited thereto, the environmentally degradable resin may include, in addition to the above-mentioned polyester-based resins, polyamides having an ester structure in the main chain as environmentally degradable resins having a main chain containing an ester structure, and in addition to the above-mentioned natural polymers, non-polyester-based resins may include biodegradable polycarbonates (PC) such as polyvinyl alcohol (PVA), polyamide 4 (PA4), and aliphatic polycarbonates. Here, the environmentally degradable resin may contain the same type of aliphatic polyester resin, aromatic-aliphatic polyester resin, and PHA resin, or two or more different types. When containing different types, the environmentally degradable resin may include a combination of an aliphatic polyester resin and an aromatic-aliphatic polyester resin, a combination of an aliphatic polyester resin and a PHA resin, a combination of an aromatic-aliphatic polyester resin and a PHA resin, or a combination of an aliphatic polyester resin, an aromatic-aliphatic polyester resin, and a PHA resin. In this case, the PHA resin may include at least a P3HB resin, or may include only a P3HB resin. The environmentally degradable resin may contain the above-mentioned polyester-based resin alone, or may contain a polyester-based resin and a non-polyester-based resin, or a copolymer of a polyester-based resin and a non-polyester-based resin.

[0023] The lower limit of the content of the environmentally degradable resin contained in the layer-forming material is, for example, 10% by mass or more, preferably 12.5% ​​by mass or more, and more preferably 15% by mass or more, based on 100% by mass of the total content of the ionically crosslinkable polymer, ionically crosslinking agent, and environmentally degradable resin. On the other hand, the upper limit of the content of the environmentally degradable resin contained in the layer-forming material is not particularly limited, but may be 99.9% by mass or less, 99.7% by mass or less, or 99.5% by mass or less, based on 100% by mass of the total content of the ionically crosslinkable polymer, ionically crosslinking agent, and environmentally degradable resin.

[0024] An ionically crosslinkable polymer is a polymer that has ionically crosslinking groups. The ionic crosslinking agent is an agent that itself serves as a crosslinking point for an ionic crosslinking reaction. The ionically crosslinkable polymer and the ionically crosslinking agent may each be contained in one kind or in two or more kinds.

[0025] The ionically crosslinkable polymer is in the form of a powder or liquid at room temperature and under normal pressure. The ionic crosslinking agent is in the form of a powder or liquid at room temperature and under normal pressure. The forms of the ionically crosslinkable polymer and the ionically crosslinking agent can be used in any combination, and a powdered ionically crosslinkable polymer and a powdered ionically crosslinking agent may be used, or a powdered ionically crosslinkable polymer and a liquid ionically crosslinking agent may be used.

[0026] The shape of at least one of the ionically crosslinkable polymer and the ionically crosslinking agent may include, for example, one or more selected from the group consisting of spherical, flat, fibrous, polyhedral, crushed, and irregular shapes. By using such granular shapes, dispersibility in the environmentally degradable resin can be improved. In this embodiment, the shapes of the ionically cross-linkable polymer and the ionically cross-linking agent can be measured by image observation using an SEM, TEM, AFM, confocal microscope, etc. Alternatively, a laser diffraction / scattering particle distribution measuring device may be used.

[0027] 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

[0028] 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."

[0029] (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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] (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.

[0034] 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.

[0035] (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.

[0036] 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.

[0037] The layer-forming material may also contain one or more selected from the group consisting of (X) hydrates of the ionic crosslinkers described above, (Y) inorganic hydrates other than (X), and (Z) sodium silicate. The (Y) inorganic hydrate is not limited as long as it is an inorganic hydrate other than the (X) ionic crosslinker, but it is preferable that it does not include a hydrate of a salt containing any ion selected from the group consisting of calcium ions, magnesium ions, and aluminum ions. Specific examples of (Y) inorganic hydrates that can be used include sodium carbonate decahydrate, sodium acetate trihydrate, sodium thiosulfate pentahydrate, disodium hydrogen phosphate dihydrate, disodium hydrogen phosphate heptahydrate, disodium hydrogen phosphate octahydrate, disodium hydrogen phosphate dodecahydrate, sodium dihydrogen phosphate monohydrate, sodium dihydrogen phosphate dihydrate, magnesium chloride hexahydrate, cobalt chloride hexahydrate, copper(II) sulfate pentahydrate, cobalt(II) iodide hexahydrate, tin(II) chloride dihydrate, and iron(III) oxide hydrate.

[0038] Furthermore, the layer-forming material may include an ionically cross-linked material having at least ionic cross-links within its molecules, or may not include an ionically cross-linked material.

[0039] The ionically cross-linked material preferably comprises an ionically cross-linked water-absorbing polymer. Compared to conventional layer-forming materials such as polyolefin resins, ionically cross-linked water-absorbent polymers are able to absorb water and swell. Even when an ionically cross-linked water-absorbent polymer that has absorbed water gels, it is believed that the fertilizer inside dissolves in the water in the gel and is released to the outside. It is sufficient for the ionically cross-linked water-absorbent polymer to be able to absorb water, and it may or may not absorb oil other than water. The weight average molecular weight of the ionically cross-linked material and the ionically cross-linked water-absorbent polymer may each be, for example, 1,000 or more and 10,000,000 or less.

[0040] The ionically crosslinked water-absorbing polymer preferably contains at least one of the following (i) to (vi) as a polymer salt containing at least two of the following (A') to (D'). (i) (A') and (C'), (ii) (A'), (C') and (D') (iii) (A'), (B'), and (C') (iv) (A') and (B') (v) (B') and (D') (vi) (A'), (B'), (C') and (D') (A') Polyanion having monovalent or divalent or higher anionic groups (B') Polycation having monovalent or divalent or higher cationic groups (C') Polyvalent inorganic cations having monovalent or divalent or higher cations (D') Anionic monomer having a monovalent or divalent or higher anionic group

[0041] The layer-forming material can improve its seawater decomposition ability by containing the above-mentioned polymer salt as the ion-crosslinked water-absorbent polymer. The term "seawater decomposability" refers to a change in the properties of the polymer salt that makes it more soluble in aqueous solvents due to an ion exchange reaction between ions present in seawater and ions in the polymer salt. When the layer-forming material is dissolved and fragmented in seawater, the surface area increases, increasing the number of microorganisms that come into contact with the surface, which is expected to accelerate the decomposition of the environmentally degradable resin.

[0042] The mechanism of seawater decomposition will be explained using an example in which the ionically cross-linked water-absorbent polymer contains the polymer salts (A') and (C') as the combination (i) above. However, the ionically cross-linked water-absorbent polymer is not limited to this. Ionically cross-linked polymers of alginate polymers (polyanions with monovalent anionic groups) and calcium ions (polyvalent inorganic cations) form ionic cross-linked structures in water, but in salt water (seawater), the calcium ions are exchanged for sodium, dissociating the cross-links, making the polymer soluble in salt water.

[0043] In another embodiment, the ionically crosslinked water-absorbing polymer is preferably a polymer salt containing at least one of (A') a polyanion having a monovalent or divalent or higher anionic group and (D') an anionic monomer having a monovalent or divalent or higher anion. More specifically, it is more preferable to use a polymer salt containing at least one of the above (i) and (ii).

[0044] The layer-forming material may or may not contain, as the ionically crosslinked water-absorbent polymer, an ionically crosslinked material obtained by reacting the above-mentioned ionically crosslinkable polymer with the above-mentioned ionically crosslinking agent.

[0045] The layer-forming material may contain additives other than the ionically crosslinkable polymer, ionically crosslinking agent, and environmentally degradable resin, 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.

[0046] (inorganic filler) In the first embodiment, the inorganic filler includes an anisotropically shaped inorganic filler P1 and a spherical or irregularly shaped inorganic filler Q1.

[0047] The inorganic filler P1 may have a plate-like, flat, or fibrous form, i.e., the inorganic filler P1 may contain at least one of a plate-like inorganic filler, a flat inorganic filler, and a fibrous inorganic filler. The plate-like shape may include a scale-like shape, and the fiber-like shape may include a needle-like shape.

[0048] The inorganic filler P1 may have a lower limit of the aspect ratio of, for example, 2 or more, preferably 2.2 or more, and more preferably 2.4 or more. The upper limit of the aspect ratio of the inorganic filler P1 is not particularly limited, but may be, for example, 200 or less, 180 or less, or 160 or less. On the other hand, the upper limit of the aspect ratio of the inorganic filler Q1 may be, for example, less than 2, 1.9 or less, or 1.8 or less. The lower limit of the aspect ratio of the inorganic filler Q1 may be, for example, 1.0 or more.

[0049] In this specification, the morphology and aspect ratio of the inorganic filler can be measured by image observation using SEM, TEM, AFM, confocal microscope, or the like. The aspect ratio of a plate-like or fibrous inorganic filler can be defined as long width / short width, which will be described later. Furthermore, the aspect ratio of a plate-like or flat inorganic filler may be defined as a thickness smaller than a width, but if the thickness is thin, it can be defined as a width / thickness ratio. For example, in the case of a flat shape such as a disk, ellipse, or scale, it is preferable to calculate the aspect ratio using the above-mentioned "width / thickness ratio." However, in the case of an inorganic filler that is so thin that its thickness cannot be measured due to the detection limit of image observation, the aspect ratio specified by "width / thickness ratio" may be calculated using the lower measurement limit (e.g., 0.1 μm) for the thickness value. On the other hand, the aspect ratio of a spherical or amorphous inorganic filler can be defined as the long width / short width described below. Here, the outline of the inorganic filler is obtained by observing the image as described above, and based on this outline, the line segment with the longest straight-line distance from one end to the other end is determined, and this is taken as the longest axis. When the line segment with the smallest width of the outline measured in a direction perpendicular to the longest axis is taken as the shortest axis, the length of the longest axis can be taken as the above-mentioned "long width" and the length of the shortest axis can be taken as the above-mentioned "short width." Regarding the shape of the inorganic filler in three-dimensional space, when the maximum width is projected in the xy-axis direction, the thickness may be considered to be projected in the z-axis direction.

[0050] When the total content of inorganic filler P1 and inorganic filler Q1 contained in the layer-forming material is taken as 100% by mass, the content of inorganic filler P1 is, for example, 1 to 99% by mass, preferably 10 to 90% by mass, and more preferably 20 to 80% by mass. In a laminate including an upper layer and a lower layer made of layer-forming materials, the content of inorganic filler P1 in the upper layer may be, for example, 1 to 99 mass%, preferably 10 to 90 mass%, and more preferably 20 to 80 mass%, when the total content of P1 and Q1 is 100 mass%, and the content of inorganic filler P1 in the lower layer may be, for example, 1 to 99 mass%, preferably 10 to 90 mass%, and more preferably 20 to 80 mass%, when the total content of P1 and Q1 is 100 mass%.

[0051] In the second embodiment, the inorganic filler includes an inorganic filler P2 and an inorganic filler Q2 having an average particle size smaller than the average particle size of the inorganic filler P2. The inorganic filler P2 has an average particle size of, for example, 0.1 to 50 μm, preferably 0.2 to 40 μm, and more preferably 0.3 to 30 μm. On the other hand, the inorganic filler Q2 has an average particle size of, for example, 0.1 to 50 μm, preferably 0.2 to 40 μm, and more preferably 0.3 to 30 μm.

[0052] The ratio of the average particle size of the inorganic filler P2 to the average particle size of the inorganic filler Q2 is, for example, 1.1 to 5,000, preferably 1.2 to 4,000, and more preferably 1.3 to 3,000.

[0053] In this specification, the average particle size of the inorganic filler can be measured by observing images using an SEM or the like. The particle diameter of each particle can be calculated by obtaining the outline of the inorganic filler by observing the image as described above, determining the line segment with the longest linear distance from one end to the other end based on the outline, defining this as the longest axis, defining the line segment with the smallest width of the outline measured in a direction perpendicular to the longest axis as the shortest axis, defining the length of the longest axis as L, and the length of the shortest axis as S, and then averaging these lengths, i.e., (L+S) / 2. The average particle size can be calculated from the average particle size of at least 100 samples, preferably 200 samples, of each particle contained in inorganic filler P2 or inorganic filler Q2, although the number of samples is not particularly limited.

[0054] When the total content of inorganic filler P2 and inorganic filler Q2 contained in the layer-forming material is taken as 100% by mass, the content of inorganic filler P2 is, for example, 1 to 99% by mass, preferably 10 to 90% by mass, and more preferably 20 to 80% by mass. In a laminate including an upper layer and a lower layer made of layer-forming materials, the content of inorganic filler P2 in the upper layer may be, for example, 1 to 99 mass%, preferably 10 to 90 mass%, and more preferably 20 to 80 mass%, when the total content of P2 and Q2 is 100 mass%, and the content of inorganic filler P2 in the lower layer may be, for example, 1 to 99 mass%, preferably 10 to 90 mass%, and more preferably 20 to 80 mass%, when the total content of P2 and Q2 is 100 mass%.

[0055] 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.

[0056] Specifically, the inorganic fillers P1, P2 and the inorganic fillers Q1, Q2 can be selected from the inorganic fillers exemplified above. As the anisotropic inorganic filler P1, for example, plate-like talc can be used. The platy talc may contain, based on 100 mass%, 75 mass% to 88 mass% of MgO and SiO2 in total, and 3.0 mass% or more of Al2O3. In addition, as the inorganic filler P2 having a relatively large particle size, talc having a particle size (median size) of 0.01 to 10 μm, preferably 0.02 to 9.9 μm, and more preferably 0.03 to 9.8 μm at the point where the cumulative volume from the small particle side is 50% in the volume-based frequency distribution of particle sizes measured by laser diffraction scattering method can be used.

[0057] In this embodiment, the inorganic filler contained in the layer-forming material may be contained in either inorganic filler P1 or inorganic filler P2, or may be contained in both. Furthermore, the other inorganic filler contained in the layer-forming material may be contained in either inorganic filler Q1 or inorganic filler Q2, or may be contained in both.

[0058] The upper limit of the total content of the inorganic filler is, for example, 50% by mass or less, preferably 49% by mass or less, and more preferably 48% by mass or less, based on 100% by mass of the layer-forming material, which can improve the coating strength of the layer-forming material. The lower limit of the total content of the inorganic filler is, for example, 1% by mass or more, preferably 2% by mass or more, and more preferably 3% by mass or more, based on 100% by mass of the layer-forming material. This allows the moisture permeation rate to be controlled low due to the water-blocking effect.

[0059] The layer-forming material may contain at least one of a surfactant and a sizing agent, or may contain neither of them. The surfactant and the sizing agent can control the dispersion state of the ionically crosslinked material. 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. These may be contained alone or in any combination of two or more.

[0060] The layer-forming material may contain a hydrophobic substance, which can suppress blocking and improve spray characteristics. The hydrophobic substance may contain one or more selected from the group consisting of a hydrophobic substance and a fatty acid. That is, the hydrophobic substance may be any of wax alone, fat alone, and fatty acid alone, or a mixture of wax and fat, fat and fatty acid, wax and fatty acid, and hydrophobic substance and fatty acid. The hydrophobic substance is either a hydrophobic substance or a fatty acid, or a mixture of two or more of the group consisting of these, and may include, for example, one or more selected from the group consisting of hydrocarbon waxes, fatty acid waxes, higher alcohol waxes, glycerin fatty acid esters, and fatty acids. Here, the wax may be any one of hydrocarbon waxes, fatty acid waxes, and higher alcohol waxes, or a mixture thereof. The fatty acid wax may contain, for example, one or more waxes selected from the group consisting of aliphatic esters, aliphatic ketones, aliphatic amides, and fatty acid metal soaps. The wax may be any of natural wax, synthetic wax, and modified wax. Natural waxes include those derived from plants, animals, minerals, and petroleum. On the other hand, examples of fats and oils include glycerin fatty acid esters. The glycerin fatty acid esters may include any one of monoglycerin fatty acid esters, diglycerin fatty acid esters, and triglycerin fatty acid esters, or a mixture of two or more of these. In addition, the glycerin fatty acid esters may include polyglycerin fatty acid esters, such as those in which one hydroxyl group of glycerin is dimerized via an ether bond. Examples of fatty acids include fatty acids having less than 10 carbon atoms and higher fatty acids having 10 or more carbon atoms. Fatty acids may include straight-chain fatty acids having a main chain and no side chains, branched fatty acids having a main chain and a side chain, and / or cyclic fatty acids having at least one ring structure. Fatty acids may also include fatty acid derivatives such as hydroxy fatty acids having at least one hydroxyl group and polymers of hydroxy fatty acids. These may be used alone or in combination of two or more. The fatty acids and aliphatic skeletons each contain saturated bonds and / or unsaturated bonds. The glycerin fatty acid esters may include highly purified products that have been purified by distillation or the like. The hydrophobic substance may include one or more of the following waxes and vegetable oils. Specific 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. Specific 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.

[0061] Here, a method for producing the layer-forming material will be described.

[0062] The method for producing the layer-forming material may include a step of melt-kneading raw material components including the ionically cross-linkable polymer, the ionically cross-linking agent, and the environmentally degradable resin using a kneading device to obtain a solid layer-forming material.

[0063] The order in which the raw material components are fed to the kneading device is not particularly limited, but after the addition of the environmentally degradable resin, an ionically crosslinkable polymer, an ionically crosslinking agent, and / or other additives may be added depending on various applications. For example, multiple raw material components may be added simultaneously or sequentially. If necessary, at least two or more components contained in the raw material ingredients may be mixed in advance before kneading the raw material ingredients.

[0064] The temperature during melt kneading can be adjusted depending on the melting point or softening point of the environmentally degradable resin used, and may be, for example, 50 to 300°C, preferably 70 to 290°C, and more preferably 90 to 280°C.

[0065] The raw material ingredients may contain moisture contained in each component of the raw material ingredients and / or moisture supplied from an external source separately from the raw material ingredients. Examples of moisture contained in the ingredients include adsorbed water and water of crystallization.

[0066] Another method for producing a layer-forming material may include a step of obtaining a varnish-like layer-forming material containing raw material components including the ionically crosslinkable polymer, the ionically crosslinking agent, and the environmentally degradable resin, and a solvent. If necessary, the raw material components may contain other additives depending on the intended use.

[0067] The solvent may include a solvent having a boiling point of 30°C to 210°C. The solvent is preferably an organic solvent (non-aqueous solvent), and examples thereof include halogenated solvents such as chloroform, aromatic solvents such as toluene, aliphatic solvents such as hexane, alicyclic solvents such as cyclohexane, ketone solvents such as acetone and MEK, ester solvents such as ethyl acetate, and alcohol solvents such as methanol, ethanol, isopropanol, etc. These may be contained alone or in any combination of two or more. In the case of the aqueous emulsion described below, a solvent containing water can be used, for example, a solvent containing 50% by mass or more of water. The above-mentioned non-aqueous solvents may also be used as a solvent other than water. When producing the aqueous emulsion, a general emulsification process such as a homogenizer or mechanical stirring may be used.

[0068] In the step of obtaining a varnish-like layer-forming material, the order in which the components contained in the raw material ingredients are mixed with the solvent is not particularly limited. Heating may or may not be performed at any stage during mixing.

[0069] The varnish-like layer-forming material may be a one-component liquid containing at least an ionic crosslinking agent, an ionic crosslinkable polymer, and a second liquid, or a two-component liquid containing a first liquid containing at least an ionic crosslinking agent and a second liquid containing at least an ionic crosslinkable polymer. In the case of a two-component liquid, the environmentally degradable resin is contained in at least one of the first and second liquids.

[0070] The layer-forming materials may be in the form of a solid, a varnish, or a viscous material.

[0071] The solid layer-forming material may be in the form of powder, granules, pellets, or briquettes. As a molding method, known methods can be used depending on the shape. Powders and granules can be produced by pulverizing, cutting, etc. If necessary, treatment such as classification may be carried out. The pellets can be produced by, for example, cutting a strand obtained by extruding the molten mixture through a die. Briquettes can be produced by compressing powder or granules, or by molding a melt-kneaded mixture in a mold.

[0072] The viscous layer-forming material may be one in which at least one of the components has absorbed moisture, causing the forming material to gel, or one in which the forming material has softened due to the inclusion of a liquid component.

[0073] Next, the covering structure of this embodiment will be described.

[0074] An example of the covering structure of this embodiment is: The above-mentioned object to be covered; and a coating layer that covers at least a portion of the surface of the coating target. The coating layer covers at least a portion of the surface or the entire surface of the object to be coated. The covering layer may include at least one layer made of the layer-forming material described above, and may also include one or more layers other than the layer made of the layer-forming material. When the covering layer has a multi-layer structure, the layer made of the layer-forming material may be the innermost layer, the outermost layer, or any of the intermediate layers between the inner and outer layers.

[0075] The form of the object to be coated is solid or liquid in the atmosphere at 25°C. The shape of the object to be coated is not particularly limited, and may be granular, pellet-like, briquette-like, or any other irregular shape. Among these, the object to be coated may be a granular solid or a granular liquid. The granular solid may be formed of powder or granules, or may be spherical with a cross-sectional shape of a substantially circular or elliptical shape. The surface of the granular solid may be smooth or may have an irregular surface.

[0076] The coating target may include agriculturally active ingredients such as fertilizer ingredients and pesticide ingredients, which will be described later. These may be contained alone or in any combination of two or more. The object to be coated may contain a gas such as air or a solvent such as water.

[0077] (fertilizer ingredients) As the fertilizer component, known fertilizers can be used, for example, one or more of nitrogenous fertilizers, phosphorous fertilizers, and potassium fertilizers can be used. As nitrogenous fertilizers, for example, ammonium salts and nitrates are used, and specific examples include ammonium sulfate, ammonium chloride, urea, lime nitrogen, sodium nitrate, and ammonium nitrate. Examples of phosphorus fertilizers include calcium superphosphate, calcium triple superphosphate, fused phosphate fertilizer, and calcined phosphate fertilizer. Examples of potassium fertilizers include potassium chloride and potassium sulfate. In addition to the above three fertilizers, the fertilizer may also contain other fertilizers (calcareous fertilizers, silicate fertilizers, manganese fertilizers, boron fertilizers, etc.) and one or more known inorganic compounds containing inorganic nutrients.

[0078] The fertilizer components may contain other components as long as the effects of the present invention are not impaired. Other components may include, for example, carriers such as clay, kaolin, talc, bentonite, calcium carbonate, etc.; binders such as polyvinyl alcohol, sodium carboxymethyl cellulose, starches, etc.; and, if necessary, surfactants such as polyoxyethylene nonylphenyl ether, blackstrap molasses, animal oil, vegetable oil, hydrogenated oil, fatty acid, fatty acid metal salt, paraffin, wax, glycerin, etc. These may be used alone or in combination of two or more.

[0079] For example, the form of the fertilizer component is not particularly limited as long as it is solid in the atmosphere at 25°C. An example of the shape of the fertilizer component may be, for example, granular fertilizer.

[0080] The granular fertilizer can be produced by using a known granulation method such as a fluidized bed granulation method, a tumbling granulation method, a coating granulation method, an adsorption granulation method, or an agglomeration granulation method, but the method for producing the granular fertilizer is not limited to these.

[0081] The coating layer that coats the fertilizer components may contain the following functional additives, if necessary. The functional additive is not particularly limited as long as it is used in the layer-forming material of the fertilizer, and examples thereof include fillers other than the inorganic fillers described above, thickeners, adhesion promoters, surface modifiers (such as inorganic fillers), pH adjusters, crosslinking retarders (chelating agents), reinforcing materials, gas barrier agents, magnetic materials, decomposition inhibitors, antifoaming agents, plasticizers, etc. These may be used alone or in combination of two or more. The layer-forming material may contain one or more of the functional additives.

[0082] (Pesticide ingredients) Pesticide ingredients include fungicides, insecticides, and other chemicals (including materials that use such chemicals as raw materials or ingredients and are used for such control) used to control bacteria, nematodes, mites, insects, rodents, and other plants and animals or viruses (hereinafter referred to as "pests") that harm crops (including trees and agricultural and forestry products; hereinafter referred to as "crops, etc."), as well as plant growth regulators, germination inhibitors, and other chemicals used to enhance or suppress the physiological functions of crops, etc. However, there are no particular restrictions on pesticides as long as they are chemicals used for agricultural purposes, and any chemical can be used, including insecticides, fungicides, and herbicides.

[0083] Next, a method for manufacturing the covering structure of this embodiment will be described.

[0084] An example of the method for producing the coated structure of this embodiment may include a step of forming a coating layer on the surface of the object to be coated using the layer-forming material described above.

[0085] The coating layer can be formed by any known method. Depending on the formation method, the form of the layer-forming material can be selected from those described above. For example, when spraying is used as the formation method, a varnish-like form may be selected as the form of the layer-forming material.

[0086] The coating layer can be formed by any known method for coating the surface of solid particles, including, for example, chemical methods such as a non-aqueous wet method, an aqueous wet method, a gas phase reaction method, and a mechachemical method, and physical methods such as a mechanical surface treatment method, a laser ablation method, an air suspension coating method, and a spray drying method. When coating the layer-forming material on the object to be coated, it is preferable to use a fluidized bed granulation method or a rolling granulation method. When applying such a production method, it is preferable to use a layer-forming material in a varnish form. However, when using a solid layer-forming material, it is also possible to use a varnish made by dissolving it in a solvent. Alternatively, the object to be coated may be coated using an aqueous dispersion emulsion containing the layer-forming material.

[0087] 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]

[0088] 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.

[0089] <Production of Layer-Forming Materials> Example 1 Sodium alginate (manufactured by Tokyo Chemical Industry Co., Ltd.) as an ion-crosslinkable polymer, aluminum sulfate 14-18 hydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as an ion-crosslinking agent, and plate-shaped talc (aspect ratio 55, average particle size 5.5 μm) and spherical calcium carbonate (aspect ratio 1.3, average particle size 2.1 μm) as inorganic fillers were ground and mixed in a mortar to obtain a mixture. The obtained mixture was mixed with polybutylene succinate (PBS) as an environmentally degradable resin under heating to obtain the layer-forming material of Example 1. The content of the inorganic filler in 100% by mass of the layer-forming material in Example 1 was 40% by mass (talc 10% by mass, calcium carbonate 30% by mass). The aspect ratio and average particle size of the inorganic filler were measured by observing SEM images. Specifically, the contours of the individual particles contained in the inorganic filler were obtained by observing SEM images, and based on these contours, the line segment with the longest straight-line distance from one end to the other was determined, which was designated as the longest axis, and the line segment with the smallest width of the contour measured in a direction perpendicular to the longest axis was designated as the shortest axis, and the length of the longest axis (L) and the length of the shortest axis (S) were measured. For spherical inorganic fillers, the length of the longest axis was defined as the "longest width" and the length of the shortest axis as the "shortest width." Using the measurements of 200 sample particles, the aspect ratio was calculated as "average long width / average short width." On the other hand, for plate-like inorganic fillers, the aspect ratio was calculated using the measured values ​​of 200 sample particles as "average long width / thickness." Since the thickness of all sample particles was too thin to measure and was smaller than the short width, "thickness" was used instead of "short width," and the lower measurement limit of 0.1 μm was used as the value of this "thickness." In addition, the average values ​​of L and S were calculated using the measured values ​​of 200 sample particles, and the average particle size was calculated by "(average value of L+average value of S) / 2".

[0090] (Layer-forming material of Reference Example 1) A layer-forming material of Reference Example 1 was obtained in the same manner as the layer-forming material of Example 1, except that talc was not used and the calcium carbonate content was 40 mass %.

[0091] (Layer-forming material of Reference Example 2) A layer-forming material of Reference Example 2 was obtained in the same manner as the layer-forming material of Example 1, except that calcium carbonate was not used and the talc content was 40 mass %.

[0092] <Evaluation of urea sustained release> (Preparation of 50 evaluation samples) First, the layer-forming material obtained above was molded to produce a layer with a thickness of about 100 μm, which was then punched out into a circle with a diameter of 15 mm to obtain a test piece 10. Next, using a tablet forming machine, solid urea (specific gravity: approximately 1.3) was formed 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 a cylindrical tablet, and a cylindrical urea tablet 20 having flat upper and lower surfaces 21 was obtained. Next, the inner surface 13 of the test piece 10 was placed facing the upper and lower surfaces of the urea tablet 20, and these sides 23 were fixed using ring-shaped silicone rubber (waterproof member 30) to produce an evaluation sample 50.

[0093] (Measurement of urea release amount) 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. The evaluation sample 50 was subjected to a water treatment by immersing it in distilled water (water 60) at a liquid temperature of 35°C stored in a polypropylene container 70 at room temperature of 25°C and atmospheric pressure, as shown in Fig. 1. During the water treatment, the outer surface 11 of the test piece 10 was kept in contact with the water 60. 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 was determined from a calibration curve. From the obtained results, the amount of urea in the urea tablet 20 that has moved into the external water 60 (urea dissolution rate) can be measured. 80 (days) was calculated.

[0094] The above <Evaluation of urea sustained release> showed that T 80 The results showed that the value of Example 1 was more than 5 times larger than that of Reference Example 1 and more than 2 times larger than that of Reference Example 2. In other words, it was found that the sustained release property can be controlled so as to reduce the sustained release rate in the layer of Example 1. [Explanation of symbols]

[0095] 10 test specimens 11 Exterior 13 Inner 20 urea tablets 23 Side 30 Waterproofing materials 50 evaluation samples 60 water 70 containers

Claims

1. The composition comprises an ionically crosslinkable polymer, an ionically crosslinking agent, an environmentally degradable resin, and an inorganic filler, The inorganic filler includes an anisotropic shaped inorganic filler P1 and a spherical or irregular shaped inorganic filler Q1. Layer forming material.

2. The layer-forming material according to claim 1 , The layer-forming material, wherein the anisotropic inorganic filler P1 has a shape that includes at least one of a plate shape, a flat shape, and a fiber shape.

3. The layer-forming material according to claim 1 or 2, The layer-forming material, wherein the anisotropically shaped inorganic filler P1 has an aspect ratio of 2 or more.

4. The composition comprises an ionically crosslinkable polymer, an ionically crosslinking agent, an environmentally degradable resin, and an inorganic filler, The inorganic filler includes an inorganic filler P2 and an inorganic filler Q2 having an average particle diameter smaller than the average particle diameter of the inorganic filler P2. Layer forming material.

5. The layer-forming material according to claim 4, A layer-forming material, wherein the ratio of the average particle size of the inorganic filler P2 to the average particle size of the inorganic filler Q2 is 1.1 or more and 5,000 or less.

6. The layer-forming material according to claim 1 or 4, The layer-forming material, wherein the inorganic filler comprises 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.

7. The layer-forming material according to claim 1 or 4, The ionically crosslinkable polymer contains at least one of the following components (A) and (B): When the ionically crosslinkable polymer contains the following component (A), the ionically crosslinking agent contains one or more selected from the group consisting of the following components (B), (C), and (D), A layer-forming material, wherein when the ionically crosslinkable polymer contains the following component (B), the ionically crosslinking agent 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 valent 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

8. The layer-forming material according to claim 1 or 4, A layer-forming material used to form a coating layer on the surface of an object to be coated.

9. The layer-forming material according to claim 8, A layer-forming material, wherein the object to be coated comprises an agriculturally active ingredient.

10. a coating object; a coating layer that covers at least a portion of the surface of the coating object, A coated structure, wherein the coating layer comprises the layer-forming material according to claim 1 or 4.

11. A method for producing a coated structure, comprising the step of forming a coating layer on a surface of an object to be coated using the layer-forming material according to claim 1 or 4.

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