Polyurethane resin composition for granular agricultural material coating and composite particle agricultural material

Abstract

To provide a polyurethane resin for granular agricultural material coating, which exhibits biodegradability, an excellent function for controlling slow solubility or the like for adjusting an elution speed of a medicine to a prescribed speed, and high shock resistance.SOLUTION: The polyurethane resin for granular agricultural material coating satisfies the following three conditions (1) to (3): (1) a polyol component (A) which is a constituent monomer of the polyurethane resin contains polyester polyol (A1), polyether polyol (A2), and / or polyester polyether polyol (A3), (2) a total weight rate of the polyester polyol (A1) and the polyester polyether polyol (A3) contained in the polyol component (A) is 80 wt.% or more on the basis of a weight of the polyol component (A), and (3) hydroxyl values of the polyester polyol (A1) and the polyester polyether polyol (A3) are respectively 5 to 130 mgKOH / g.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polyurethane resin composition for coating granular agricultural materials and a composite particle-type agricultural material. [Background technology]

[0002] In the fields of pharmaceuticals, agriculture, food additives, cosmetics, sanitary products, etc., sustained-release agents that slowly release active ingredients are extremely useful and widely used in terms of their long-lasting effects and ease of handling. Among these, sustained-release agents used for agricultural chemicals (fertilizers, pesticides, pest control agents, etc.), algae control agents, and agents for preventing the adhesion of aquatic organisms often have a plastic coating shell. However, since the coating shell flows into rivers, oceans, etc. after the active ingredient is released and becomes plastic waste, there has been a recent demand from the perspective of environmental protection for the coating (coating layer) to be biodegradable.

[0003] One method of imparting biodegradability to the coating layer of a sustained-release drug is to use a biodegradable material such as natural rubber or biodegradable polyester as the coating layer. However, a coating layer made solely of a biodegradable material can result in the drug dissolving too quickly, and so research has been conducted into coating layers made of mixtures of a biodegradable material and a non-biodegradable resin such as a polyolefin resin. For example, Patent Document 1 proposes a coated granular fertilizer having a coating layer containing 4% to 80% by weight of an aliphatic polyester, 19% to 95% by weight of a polyolefin, and 0.00001% to 10% by weight of a photodegrader. The coating layer described in Patent Document 1 combines a non-biodegradable polyolefin resin with a photodegrader that promotes the oxidative decomposition of the polyolefin, thereby attempting to achieve both a wide range of fertilizer release control and the degradability of the coating layer. However, the degradability of the coating layer was not sufficient, and there were problems with the coating layer's degradability and the rate of release of the chemicals varying significantly depending on the environment in which it was used. Furthermore, the coating layer's low impact resistance sometimes led to problems such as breakage during storage or application.

[0004] Also proposed is a method of controlling the decomposition rate of the coating layer and the release rate of the drug by providing an additional protective layer on the outside of the coating layer made of a biodegradable resin. For example, Patent Document 2 proposes a coated granular fertilizer in which a coating layer is provided on the surface of a granular material containing fertilizer components, the coating layer being characterized by having a resin coating layer made of a biodegradable resin such as a urethane resin formed by polymerizing a polyisocyanate component and a polyol component containing polycaprolactone diol, and a protective layer containing an antibacterial agent and hardened vegetable oil provided on the outside of the resin coating layer. However, although the coating layer described in Patent Document 2 only slightly changes the elution rate of the fertilizer depending on the application situation, there are problems with the gradual dissolution control function for adjusting the elution rate of the agent to a predetermined rate and with the impact resistance of the coating layer. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 11-43391 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-178579 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in consideration of the above problems, and an object of the present invention is to provide a polyurethane resin for coating granular agricultural materials that is biodegradable, has excellent controllability for adjusting the dissolution rate of a drug to a predetermined rate, and also has excellent impact resistance. [Means for solving the problem]

[0007] The present inventors have conducted extensive research to solve the above problems and have arrived at the present invention. Specifically, the present invention relates to a polyurethane resin for coating granular agricultural materials, which comprises a polyurethane resin that satisfies the following (1) to (3), and a composite particulate agricultural material having a coating layer containing the polyurethane resin for coating granular agricultural materials on at least a portion of the surface of the granular agricultural material. (1) The polyol component (A), which is a constituent monomer of the polyurethane resin, is a polyol component containing a polyester polyol (A1) and a polyether polyol (A2), and / or a polyester polyether polyol (A3). (2) The total weight proportion of the polyester polyol (A1) and polyester polyether polyol (A3) contained in the polyol component (A) is 80% by weight or more based on the weight of the polyol component (A). (3) The polyester polyol (A1) and the polyester polyether polyol (A3) each have a hydroxyl value of 5 to 130 mgKOH / g. [Effects of the Invention]

[0008] The polyurethane resin for coating granular agricultural materials of the present invention is biodegradable, has excellent controllability such as gradual dissolution to adjust the dissolution rate of the agent to a predetermined rate, and also has excellent mechanical strength such as impact resistance. DETAILED DESCRIPTION OF THE INVENTION

[0009] The first invention of the present application is a polyurethane resin for coating granular agricultural materials (hereinafter sometimes abbreviated as polyurethane resin).

[0010] <Granular agricultural materials> Granular agricultural materials to be coated with the polyurethane resin for coating granular agricultural materials of the present invention include granular agricultural chemicals (N) and seeds (S). By coating the granular agricultural chemicals (N) with the polyurethane resin for coating granular agricultural materials of the present invention, it becomes possible to control the sustained release rate of the chemicals (N), and by coating the seeds (S) with the polyurethane resin for coating granular agricultural materials of the present invention, it becomes possible to control the timing of seed germination.

[0011] [Granular agricultural chemicals (N)] The granular agricultural chemicals (N) to be coated with the polyurethane resin of the present invention include known granular fertilizers, agricultural chemicals, pesticides, perfumes and dyes. Examples of granular fertilizers include urea, ammonium chloride, ammonium sulfate, ammonium nitrate, potassium chloride, potassium sulfate, potassium nitrate, sodium nitrate, potassium phosphate, ammonium phosphate, lime phosphate, and granular organic fertilizers. Granular organic fertilizers include liquid organic fertilizers supported on mineral matter and porous ceramics, and solid active ingredients dissolved and supported on mineral matter and porous ceramics. Examples of agricultural chemicals include insecticides, fungicides, herbicides, and plant growth regulators. Examples of insecticides include clothianidin, pyridalyl, permethrin, flufenoxuron [1-{4-(2-chloro-4-trifluoromethylphenoxy)-2-fluorophenyl}-3-(2,6-difluorobenzoyl)urea], and fenitrothion; examples of fungicides include mandestrobin and 2-methylthio-4-t-butylamino-6-cyclopropylamino-S-triazine; and examples of herbicides include 4-amino-3-chloro-5-fluoro-6-(4-chloro-2-fluoro-3-methoxyphenyl)pyridine-2-carboxylic acid, which are contained as active ingredients. These include those in which a liquid active ingredient is supported on minerals, porous ceramics, etc. by known methods (such as a method in which a carrier is impregnated with a solution of the active ingredient and then the solvent is volatilized off), and those in which a solid active ingredient is dissolved and supported on minerals, porous ceramics, etc. Examples of pest control agents include repellents and agents for preventing adhesion of aquatic organisms. Examples of repellents include DEET, picaridin, and P-menthane-3,8-diol, and examples of agents for preventing the adhesion of aquatic organisms include those containing as active ingredients 2-methylthio-4-t-butylamino-6-cyclopropylamino-S-triazine, 2,3,5,6-tetrachloro-4(methylsulfonyl)pyridine, aminometal copper (manufactured by Nikko Co., Ltd.), triphenyltin chloride, triphenyltin acetate, triphenyltin hydroxide, tributyltin oxide, and tripropyltin chloride. These agents include those in which a liquid active ingredient is supported on mineral matter, porous ceramics, etc. by known methods (such as a method in which a carrier is impregnated with a solution of the active ingredient and then the solvent is volatilized off), and those in which a solid active ingredient is dissolved and supported on mineral matter, porous ceramics, etc. Examples of the mineral substance that can support the liquid active ingredient include kaolin minerals such as kaolinite, montmorillonite, smectite, talc, rosestone, silica, calcium silicate hydrate, calcium carbonate, and zeolite.

[0012] [Seed (S)] The seeds (S) to be coated with the polyurethane resin of the present invention include vegetable seeds, flower seeds, pasture seeds, grain seeds, and industrial crop seeds. The seed shapes include, for example, the following shapes: (i) Long-grain seeds (e.g., lettuce seeds) having a length of 2.0 to 5.0 mm, a width of 0.5 to 2.0 mm, and a thickness of 0.3 to 0.5 mm. (ii) Nearly spherical seeds with a diameter of 1.0 to 3.0 mm (e.g., cabbage seeds) (iii) Flattened oval seeds with a diameter of 1.5 to 4.0 mm (e.g., eggplant seeds) (iv) Granular seeds (e.g., rice seeds) 5–10 mm long and 2–5 mm wide

[0013] <Polyurethane resin> The polyurethane resin for coating granular agricultural materials of the present invention is a polyurethane resin that satisfies the following (1) to (3). (1) The polyol component (A), which is a constituent monomer of the polyurethane resin, is a polyol component containing a polyester polyol (A1) and a polyether polyol (A2), and / or a polyester polyether polyol (A3). (2) The total weight proportion of the polyester polyol (A1) and polyester polyether polyol (A3) contained in the polyol component (A) is 80% by weight or more based on the weight of the polyol component (A). (3) The polyester polyol (A1) and the polyester polyether polyol (A3) each have a hydroxyl value of 5 to 130 mgKOH / g.

[0014] The polyurethane resin has a polyether structure based on a polyol component and an ester group, and therefore has excellent impact resistance and biodegradability, and can be suitably used in agricultural materials.

[0015] [Polyol component (A)] The polyol component (A) is a polyol component containing a polyester polyol (A1) and a polyether polyol (A2), and / or a polyester polyether polyol (A3). That is, the polyol component (A) is a polyol component containing a polyester polyol (A1) and a polyether polyol (A2), a polyol component containing a polyester polyol (A1), a polyether polyol (A2), and a polyester polyether polyol (A3), or a polyol component containing a polyester polyether polyol (A3).

[0016] [Polyester polyol (A1)] The polyester polyol (A1) is a polyol that does not have a poly(oxyalkylene) group and has an ester bond, and examples thereof include aliphatic polyester polyol (A11) composed of an aliphatic polyol and an aliphatic polycarboxylic acid, lactone-based polyester polyol (A12) obtained by ring-opening polymerization of a lactone using a low-molecular-weight polyol as an initiator, and aromatic polyester polyol (A13) composed of an aliphatic polyol or aromatic polyol and an aromatic polycarboxylic acid as structural units. From the viewpoints of biodegradability and sustained release, the aliphatic polyester polyol (A11) and lactone-based polyester polyol (A12) are preferred.

[0017] Examples of the aliphatic carboxylic acid constituting the aliphatic polyester polyol (A11) include aliphatic dicarboxylic acids having 3 to 10 carbon atoms (including the carbon atoms of the carboxyl group) (e.g., succinic acid, malonic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, maleic acid, and fumaric acid) and their ester-forming derivatives (e.g., acid anhydrides, lower alkyl esters, and acid halides). Of these aliphatic carboxylic acids, adipic acid is preferred from the viewpoint of biodegradability. Examples of aliphatic polyols include low-molecular-weight aliphatic polyols having 2 to 10 carbon atoms (e.g., ethylene glycol, propylene glycol, 1,3-butanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, dimethylpropanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, octanediol, 1,6-cyclohexanedimethanol, diethylene glycol, and dipropylene glycol).

[0018] Examples of the low-molecular-weight polyols that are raw materials for the lactone-based polyester polyol (A12) include the above-mentioned aliphatic low-molecular-weight polyols having 2 to 10 carbon atoms, and examples of the lactones include those having 4 to 6 carbon atoms, γ-butyrolactone, ε-caprolactone, and γ-valerolactone.

[0019] Aliphatic polyols that are raw materials for the aromatic polyester polyol (A13) include the aliphatic polyols described above, aromatic polyols include low-molecular-weight aromatic polyols {e.g., xylylene glycol, bis(hydroxyethyl)benzene, resorcinol, and bisphenol A}, and aromatic polycarboxylic acids include aromatic dicarboxylic acids having 8 to 10 carbon atoms (including the carbon atoms in the carboxyl groups) (e.g., phthalic acid, phthalic anhydride, isophthalic acid, dimethylisophthalic acid, terephthalic acid, and dimethylterephthalic acid).

[0020] The number average molecular weight (Mn) of the polyester polyol (A1) is preferably from 1,000 to 8,000, more preferably from 2,000 to 4,000, from the viewpoint of the biodegradability and impact resistance of the coating layer.

[0021] The number average molecular weight (Mn) in the present invention can be measured by gel permeation chromatography under the following conditions, for example. Device: "HLC-8120GPC" [manufactured by Tosoh Corporation] Columns: "Guardcolumn HXL-H" (1 tube), "TSKgel GMHXL" (2 tubes) [both manufactured by Tosoh Corporation] Sample solution: 0.25% by weight tetrahydrofuran solution Solution injection volume: 100μL Flow rate: 1mL / min Measurement temperature: 40℃ Detector: Refractive index detector Reference material: Standard polystyrene

[0022] The hydroxyl value (mgKOH / g) of the polyester polyether polyol (A1) is 5 to 130 mgKOH / g, preferably 5 to 85 mgKOH / g, and more preferably 15 to 60 mgKOH / g. If the hydroxyl value of the polyester polyether polyol (A1) is less than 5 mgKOH / g, coating of the coating layer becomes difficult, and if it exceeds 130 mgKOH / g, the gradual solubility of the drug decreases. The hydroxyl value in the present invention is measured in accordance with JIS K1557-1.

[0023] The acid value (mgKOH / g) of the polyester polyol (A1) is preferably 0 to 10 mgKOH / g, more preferably 0 to 3 mgKOH / g, from the viewpoint of biodegradability of the coating layer and sustained release of the drug. The acid value in the present invention is measured in accordance with JIS K0070.

[0024] [Polyether polyol (A2)] The polyether polyol (A2) is a polyol having no ester bond but an oxyalkylene group, and examples thereof include aliphatic polyether polyol (A21), aromatic polyether polyol (A22), and polyetheramine polyol (A23). Note that, in the present invention, the polyether polyol (A2) having one or more oxyalkylene groups is considered to be a polyether.

[0025] Examples of the aliphatic polyether polyol (A21) include polyether polyols obtained by adding an alkylene oxide having 2 to 4 carbon atoms (ethylene oxide, propylene oxide, and butylene oxide) to an aliphatic dihydric alcohol having 2 to 8 carbon atoms or an alicyclic group-containing dihydric alcohol having 6 to 10 carbon atoms. Examples of the aliphatic dihydric alcohol having 2 to 8 carbon atoms include linear diols (ethylene glycol, diethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, etc.) and diols having branched alkyl chains (1,2-propanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2,2-diethyl-1,3-propanediol, 1,2-, 1,3-, or 2,3-butanediol, etc.).

[0026] Examples of the aromatic polyether polyol (A22) include alkylene oxide adducts having 2 to 4 carbon atoms of aromatic ring-containing dihydric alcohols having 8 to 20 carbon atoms (such as m- or p-xylylene glycol, bis(hydroxyethyl)benzene, and bis(hydroxyethoxy)benzene), alkylene oxide adducts of bisphenols (such as bisphenol A, bisphenol S, and bisphenol F), alkylene oxide adducts of dihydroxynaphthalene, and alkylene oxide adducts having 2 to 4 carbon atoms (ethylene oxide, propylene oxide, and butylene oxide) of bis(2-hydroxyethyl)terephthalate, etc.

[0027] The polyetheramine polyol (A23) may be an alkylene oxide adduct of a polyamine or dialkanolamine. Examples of polyamines include aliphatic poly(di- to heptavalent)amines (ethylenediamine, etc.), alicyclic-containing poly(di- to tri-valent)amines, heterocyclic-containing poly(di- to tri-valent)amines, and aromatic-ring-containing polyamines, and examples of alkanolamines include alkanolamines having 4 to 12 carbon atoms (diethanolamine, triethanolamine, etc.).

[0028] As the polyether polyol (A2), polypropylene glycol, polyethylene glycol having a number average molecular weight of 300 to 1500, and a block copolymer of ethylene oxide and propylene oxide having a number average molecular weight of 300 to 2500 are preferred from the viewpoint of coverage (coverage distribution). The freezing point of the polyether polyol (A2) is preferably not more than 40° C. The freezing point (° C.) of the polyether polyol (A2) is measured in accordance with JIS K0065.

[0029] [Polyester polyether polyol (A3)] The polyester polyether polyol (A3) is a polyol having both one or more oxyalkylene groups and two or more ester bonds, and examples thereof include aliphatic polyester polyether polyols (A31), aromatic aliphatic polyester polyether polyols (A32), and aromatic polyester polyether polyols (A33). Note that, in the present invention, polyester polyether polyols (A3) having one or more oxyalkylene groups are considered to be polyethers. Examples of the aliphatic polyester polyether polyol (A31) include an aliphatic polyester polyether polyol obtained by polycondensation of the aliphatic polyether polyol (A21) and an aliphatic polycarboxylic acid, and an aliphatic polyester polyether polyol obtained by adding an alkylene oxide having 2 to 4 carbon atoms to the aliphatic polyester polyol (A11). Examples of the araliphatic polyester polyether polyol (A32) include araliphatic polyester polyether polyols obtained by polycondensation of the aliphatic polyether polyol (A21) with an aliphatic polycarboxylic acid and an aromatic polycarboxylic acid. Examples of the aromatic polyester polyether polyol (A33) include an aromatic polyester polyether polyol obtained by polycondensation of the aromatic polyether polyol (A22) with an aromatic polycarboxylic acid, and an aromatic polyester polyether polyol obtained by adding an alkylene oxide having 2 to 4 carbon atoms to the aromatic polyester polyol (A13). From the viewpoint of biodegradability, aliphatic polyester polyether polyol (A31) is preferred.

[0030] The aliphatic polycarboxylic acids constituting the aliphatic polyester polyether polyol (A31) are the same as those used in the polyester polyol (A11), and the preferred ones are also the same. The aliphatic polyether polyol (A21) constituting the aliphatic polyester polyether polyol (A31) is preferably an aliphatic polyether polyol having a molecular weight or number-average molecular weight of 1,000 or less [e.g., polyethylene glycol, polypropylene glycol, polyoxyethylene polyoxypropylene glycol, polytetramethylene ether glycol, etc.]. From the viewpoint of biodegradability, polyethylene glycol having a number-average molecular weight of 1,000 or less is more preferred, and from the viewpoint of sustained-release control, polypropylene glycol having a number-average molecular weight of 1,000 or less is even more preferred. Examples of alkylene oxide adducts having 2 to 4 carbon atoms constituting the aliphatic polyester polyether polyol (A31) include ethylene oxide, propylene oxide, and butylene oxide. From the viewpoint of biodegradability, ethylene oxide adducts are preferred, and from the viewpoint of sustained-release control, propylene oxide adducts are preferred.

[0031] The aliphatic polycarboxylic acids constituting the aromatic-aliphatic polyester polyether polyol (A32) are the same as the aliphatic polycarboxylic acids used in the polyester polyol (A11) and the preferred ones are also the same, and the aromatic polycarboxylic acids are the same as the aromatic polycarboxylic acids used in the aromatic polyester polyol (A13) and the preferred ones are also the same. The aliphatic polyether polyol constituting the aromatic aliphatic polyester polyether polyol (A32) is the same as the aliphatic polyester polyether polyol (A31).

[0032] The aromatic polyether polyol (A22) constituting the aromatic polyester polyether polyol (A33) is preferably an aromatic ring structure-containing polyether polyol having a molecular weight of 1,000 or less (e.g., an ethylene oxide adduct of bisphenol A, a propylene oxide adduct of bisphenol A, an ethylene oxide adduct of resorcinol, or a propylene oxide adduct of resorcinol). The aromatic polycarboxylic acid is the same as the aromatic polycarboxylic acid used in the aromatic polyester polyol (A13), and the preferred aromatic polycarboxylic acids are also the same.

[0033] The number average molecular weight (Mn) of the polyester polyether polyol (A3) is preferably from 1,000 to 8,000, more preferably from 2,000 to 4,000, from the viewpoint of the biodegradability and impact resistance of the coating layer.

[0034] The hydroxyl value (mgKOH / g) of the polyester polyether polyol (A3) is 5 to 130 mgKOH / g, preferably 5 to 85 mgKOH / g, and more preferably 15 to 60 mgKOH / g. If the hydroxyl value of the polyester polyether polyol (A3) is less than 5 mgKOH / g, coating of the coating layer becomes difficult, and if it exceeds 130 mgKOH / g, the gradual solubility of the drug decreases.

[0035] The acid value (mgKOH / g) of the polyester polyether polyol (A3) is preferably 0 to 10 mgKOH / g, more preferably 0 to 3 mgKOH / g, from the viewpoints of biodegradability of the coating layer and sustained release of the drug.

[0036] The polyol component (A) includes a polyester polyol (A1) and a polyether polyol (A2), and / or a polyester polyether polyol (A3), and may further include a low-molecular-weight polyol having a number-average molecular weight of less than 1,000. Examples of the low molecular weight polyol include a low molecular weight aromatic polyol (A4) and an alkanolamine (A5). For example, the inclusion of a low molecular weight aromatic polyol (A4) can slow down the dissolution rate.

[0037] Examples of the low-molecular-weight aromatic polyol (A4) include low-molecular-weight aromatic polyols {xylylene glycol, bis(hydroxyethyl)benzene, resorcinol, bisphenol A, etc.} and aromatic-containing polyether polyols having a molecular weight of less than 1,000 (ethylene oxide adducts of bisphenol A, propylene oxide adducts of bisphenol A, ethylene oxide adducts of resorcinol, propylene oxide adducts of resorcinol, etc.).

[0038] Examples of the alkanolamine (A5) include triethanolamine and diethanolamine.

[0039] The total weight proportion of the polyester polyol (A1) and polyester polyether polyol (A3) contained in the polyol component (A), which is a constituent monomer of the polyurethane resin for coating granular agricultural materials of the present invention, is 80% by weight or more based on the weight of the polyol component (A). If the total weight proportion of the polyester polyol (A1) and the polyester polyether polyol (A3) is less than 80% based on the weight of the polyol component (A), it may be difficult to achieve both biodegradability of the coating layer of the composite particles and controlled sustained release of the drug, and the coating properties and impact resistance of the composite particles at low temperatures will be impaired. The total weight of the polyester polyol (A1) and the polyester polyether polyol (A3) based on the weight of the polyol component (A) is more preferably 90% by weight or more, and particularly preferably 95% by weight or more, from the viewpoint of biodegradability. stomach.

[0040] [Polyisocyanate component (B)] As the polyisocyanate component (B) constituting the polyurethane resin, those conventionally used in the production of polyurethanes can be used, such as aliphatic polyisocyanates (B1), alicyclic polyisocyanates (B2), aromatic polyisocyanates (B3), araliphatic polyisocyanates (B4), and modified products of these polyisocyanates (B5).

[0041] Examples of the aliphatic polyisocyanate (B1) include aliphatic diisocyanates having 4 to 22 carbon atoms (the number of carbon atoms includes the carbon of an isocyanate group (hereinafter sometimes abbreviated as NCO group); the same applies to the number of carbon atoms in the polyisocyanates described below) and aliphatic triisocyanates having 4 to 22 carbon atoms, such as ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (hereinafter sometimes abbreviated as HDI), dodecamethylene diisocyanate, 1,6,11-undecane triisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethyl caproate, bis(2-isocyanatoethyl) fumarate, bis(2-isocyanatoethyl) carbonate, and 2-isocyanatoethyl-2,6-diisocyanatohexanoate.

[0042] Examples of the alicyclic polyisocyanate (B2) include alicyclic diisocyanates having 8 to 18 carbon atoms, such as isophorone diisocyanate (hereinafter sometimes abbreviated as IPDI), dicyclohexylmethane-4,4'-diisocyanate (hereinafter sometimes abbreviated as hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate, bis(2-isocyanatoethyl)-4-cyclohexene-1,2-dicarboxylate, and 2,5- or 2,6-norbornane diisocyanate.

[0043] Examples of the aromatic polyisocyanate (B3) include aromatic diisocyanates having 8 to 26 carbon atoms, aromatic triisocyanates having 8 to 26 carbon atoms, crude products of these isocyanates, and mixtures of these isocyanates, and examples thereof include 1,3- or 1,4-phenylene diisocyanate, 2,4- or 2,6-tolylene diisocyanate (hereinafter sometimes abbreviated as TDI), crude TDI, 2,2'-, 2,4'- or 4,4'-diphenylmethane diisocyanate (hereinafter sometimes abbreviated as MDI), and the like. Examples of suitable isocyanates include polymethylene polyphenylene polyisocyanate (crude MDI or polymeric MDI), polyaryl polyisocyanate, 4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatodiphenylmethane, 1,5-naphthylene diisocyanate, 4,4',4"-triphenylmethane triisocyanate, and m- or p-isocyanatophenylsulfonyl isocyanate.

[0044] Examples of the araliphatic polyisocyanate (B4) include araliphatic diisocyanates having 10 to 18 carbon atoms, such as m- or p-xylylene diisocyanate and α,α,α',α'-tetramethylxylylene diisocyanate.

[0045] The modified polyisocyanate (B5) includes modified polyisocyanates such as those containing a urethane group, a carbodiimide group, an allophanate group, a urea group, a biuret group, a uretdione group, a uretoimine group, an isocyanurate group, or an oxazolidone ring, and examples thereof include modified polyisocyanates such as modified MDI (urethane-modified MDI, carbodiimide-modified MDI, trihydrocarbyl phosphate-modified MDI, etc.), urethane-modified TDI, biuret-modified HDI, isocyanurate-modified HDI, and isocyanurate-modified IPDI.

[0046] These polyisocyanate components (B) may be used alone or in combination of two or more.

[0047] The polyol component (A), which is a constituent monomer of the polyurethane resin of the present invention, is a polyol component containing a polyester polyol (A1) and a polyether polyol (A2) or a polyester polyether polyol (A3) as essential components, and is presumed to be able to achieve both controlled gradual solubility and biodegradability due to the presence of an ester group and an alkyleneoxy group.

[0048] From the viewpoint of the biodegradability and impact resistance of the coating layer, the total weight of the ester groups possessed by the polyurethane resin for coating granular agricultural materials of the present invention is preferably 0.03 to 0.40 g, and more preferably 0.05 to 0.36 g, per 1 g of polyurethane resin. The total weight (g) of ester groups per 1 g of the polyurethane resin can be calculated by measuring infrared spectroscopy (IR) of the polyurethane resin and using the intensity of the peak derived from the ester groups and a calibration curve (plot of the relationship between peak intensity and the amount of ester groups) prepared using samples with known amounts of ester groups.

[0049] From the viewpoint of the biodegradability and coating properties of the coating layer, the total weight of alkyleneoxy groups possessed by the polyurethane resin for coating granular agricultural materials of the present invention is preferably 0.01 to 0.5 g per 1 g of polyurethane resin.

[0050] The total weight of oxygen atoms contained in the alkyleneoxy groups of the polyurethane resin is more preferably 0.05 to 0.4 g, and particularly preferably 0.1 to 0.4 g, per 1 g of polyurethane resin. If the total weight of oxygen atoms contained in the alkyleneoxy group is within the above range, the biodegradability and coverage (coverage distribution) of the coating layer will be further improved, which is preferable. The weight of the alkyleneoxy group and the weight of the oxygen atoms contained in the alkyleneoxy group can be calculated by measuring the infrared spectroscopy (IR) of the polyurethane resin, and multiplying the intensity of the peak derived from the alkyleneoxy group by the molecular weight of the alkyleneoxy group, etc., using a calibration curve (plot of the relationship between peak intensity and the amount of oxygen atoms) prepared by using a polyurethane resin with a known number of alkyleneoxy groups as a measurement sample.

[0051] The polyurethane resin for coating granular agricultural materials of the present invention preferably has a glass transition temperature of −60° C. to 0° C. A glass transition temperature in this range is preferable because it is easy to achieve both control of gradual solubility and biodegradability.

[0052] The total weight of urethane groups contained in the polyurethane resin for coating granular agricultural materials of the present invention is preferably 0.02 to 0.15 g per 1 g of polyurethane resin. If the total weight of urethane groups is within the above range, the biodegradability of the coating layer and the sustained release of the drug are further improved, which is preferable.

[0053] The amount of aromatic rings contained in the polyurethane resin for coating granular agricultural materials is preferably 0.01 to 2.0 mmol per 1 g of polyurethane resin. If the amount of aromatic rings is within the above range, the biodegradability of the coating layer and the sustained release of the drug are further improved, which is preferable.

[0054] The crosslink density (the number of moles of crosslinking points in 1 g of polyurethane resin) of the polyurethane resin for coating granular agricultural materials, calculated by the following mathematical formula (1), is preferably 0.0 to 0.8 mmol / g. If the crosslinking density is within the above range, the biodegradability of the coating layer and the controlled release of the drug can be further improved, which is preferable. Crosslinking can be performed by a method using a trifunctional or higher functional compound as the polyol component (A) and / or the polyisocyanate component (B).

[0055]

number

[0056] In formula (1), m and Ai respectively represent the following values ​​in a polyol (pa) having 3 or more hydroxyl groups in the molecule of the polyol component (A) constituting the polyurethane resin: m: number of polyol (pa)-derived units constituting polyurethane resin Ai [unit: mmol / g]: 1000 × {number of hydroxyl groups in the i-th polyol (pa) constituting the polyurethane resin minus 2} / number average molecular weight of the i-th polyol (pa) In addition, in the mathematical formula (1), n ​​and Bi respectively mean the following values ​​in the polyisocyanate (pb) having 3 or more isocyanate groups in the molecule of the polyisocyanate component (B) constituting the polyurethane resin: n: Number of polyisocyanate (pb) derived units constituting polyurethane resin Bi [unit: mmol / g]: 1000 × {number of isocyanate groups in the i-th polyisocyanate (pb) constituting the polyurethane resin minus 2} / molecular weight of the i-th polyisocyanate (pb)

[0057] The polyurethane resin for coating granular agricultural materials is a cured product of a polyurethane resin-forming composition containing a polyol component (A) and a polyisocyanate component (B) as essential components. In the polyurethane resin-forming composition, the equivalent ratio of the polyol component (A) to the polyisocyanate component (B) [{total number of moles of hydroxyl groups in the polyol component (A)} / {total number of moles of isocyanate groups in the polyisocyanate component (B)}] is preferably 1 / 0.9 to 1 / 2, and more preferably 1 / 1.1 to 1 / 1.5, from the viewpoints of sustained release of the drug and impact resistance of the coating layer.

[0058] The polyurethane resin-forming composition may further contain an aliphatic monool (E). From the viewpoints of suppressing stickiness on the particle surface and improving coating properties, the aliphatic monool (E) is preferably an aliphatic monool having a melting point of 40 to 100°C, more preferably an aliphatic monool having a melting point of 60 to 80°C. From the viewpoint of extending the period of sustained release of the drug, preferred aliphatic monools include linear aliphatic monools having 15 or more carbon atoms (such as hexadecanol, stearyl alcohol, and behenyl alcohol). The polyurethane resin-forming composition may also contain a polyester monool obtained by polycondensation of the aliphatic diol, the aliphatic dicarboxylic acid, and the aliphatic monool (E). Use of the polyester monool improves the biodegradability of the polyurethane resin.

[0059] The total weight of the polyol component (A) and the polyisocyanate component (B) in the polyurethane resin-forming composition is preferably 70% by weight or more, and more preferably 95% by weight or more, based on the weight of the polyurethane resin-forming composition. The total weight of the polyol component (A) and the polyisocyanate component (B) in the polyurethane resin-forming composition is preferably 95% by weight or more, and more preferably 98% by weight or more, based on the weight of the polyurethane resin-forming composition.

[0060] [Catalyst (C)] From the viewpoint of curability, the polyurethane resin-forming composition preferably further contains a catalyst (C).

[0061] Any catalyst that promotes a urethanization reaction can be used as the catalyst (C). From the viewpoint of the reaction rate of the curing reaction and the impact resistance of the coating layer, examples of suitable catalysts include tertiary amines {triethanolamine, triethylamine, triethylenediamine, N-ethylmorpholine, N,N-dimethylaminoethanol, bisdimethylaminoethyl ether and N-(N',N',-2-dimethylaminoethyl)morpholine, diazabicycloundecene, amine polyols, etc.} and metal carboxylates (potassium acetate, potassium octoate, stannous octoate, dibutyl tin dilaurate, lead octoate, etc.).

[0062] The catalyst (C) may be used alone or in combination of two or more kinds.

[0063] The amount of catalyst (C) used is preferably 0.01 to 5.0 parts by weight, more preferably 0.05 to 2.0 parts by weight, based on 100 parts by weight of polyol component (A).

[0064] <Composite particle type agricultural material> The composite particulate agricultural material, which is the second invention of the present application, has a coating layer (II) containing the above-mentioned polyurethane resin for coating granular agricultural materials on at least a part of the surface of the granular agricultural material.

[0065] The composite particle-type agricultural material of the present invention has a structure coated with a coating layer (II) containing the above-mentioned urethane resin for coating granular agricultural materials, and therefore has excellent control functions such as gradual dissolution, which adjusts the dissolution rate of the drug to a predetermined rate, and has excellent mechanical strength such as the impact resistance of the coating layer.

[0066] [Covering layer (II)] In the composite particle-type agricultural material of the present invention (hereinafter sometimes abbreviated as composite particles), the weight of the coating layer (II) relative to 100 parts by weight of the granular agricultural material is preferably 1 to 10% by weight, more preferably 2 to 7% by weight, from the viewpoints of sustained release of the drug and impact resistance.

[0067] The content of the polyurethane resin for coating granular agricultural materials in the coating layer (II) in the present invention is preferably 60% by weight or more, and more preferably 80% by weight or more, based on the weight of the coating layer (II), from the viewpoint of achieving both biodegradability of the coating layer and control of the sustained release of the drug.

[0068] The average thickness of the coating layer (II) in the present invention is preferably 1 to 80 μm, more preferably 5 to 40 μm, from the viewpoint of sustained release of the drug and prevention of peeling from the sustained-release drug particles (Y).

[0069] The coating layer (II) in the present invention may further contain a solubility regulator (D) for the purposes of lowering the moisture permeability of the coating layer and adjusting the solubility of the drug.

[0070] [Slow-dissolving agent (D)] Examples of the solubility regulator (D) include hydrophobic waxes, hydrophobic plasticizers, olefin resins, carbodiimide compounds, oxazoline compounds, isocyanate compounds, epoxy compounds, ester compounds (natural fats and oils, naturally derived fatty acid ester waxes, synthetic waxes, etc.), amide compounds, urethane compounds other than polyurethane resins for coating granular agricultural materials, and organic clays.

[0071] Examples of hydrophobic waxes include hydrocarbon waxes (paraffin, etc.) and metal soaps (aluminum stearate, calcium stearate, etc.).

[0072] Examples of hydrophobic plasticizers include low molecular weight aliphatic polyesters having a weight average molecular weight of 20,000 or less {succinic acid and ethylene glycol / propylene glycol condensate (for example, trade name "Polysizer", manufactured by DIC Corporation)}.

[0073] Examples of the carbodiimide compound include poly(4,4'-diphenylmethanecarbodiimide), poly(p-phenylenecarbodiimide), poly(m-phenylenecarbodiimide), poly(tolylcarbodiimide), poly(diisopropylphenylenecarbodiimide), poly(methyl-diisopropylphenylenecarbodiimide), and poly(triisopropylphenylenecarbodiimide).

[0074] Commercially available carbodiimide compounds include "Stavaxol" manufactured by Rhein Chemie and "Carbodilite" manufactured by Nisshinbo Chemical Inc.

[0075] Examples of the oxazoline compound include monooxazoline compounds such as 2-methyl-2-oxazoline, 2-ethyl-2-oxazoline, 2-phenyl-2-oxazoline, 2-isopropenyl-2-oxazoline, and 2,4-dimethyl-2-oxazoline; bisoxazoline compounds such as 2,2'-(1,3-phenylene)bis(2-oxazoline); and polymers having an oxazoline group in the side chain.

[0076] Examples of the isocyanate compound include hexamethylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylylene diisocyanate, and diphenylmethane diisocyanate.

[0077] Epoxy compounds include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polybutadiene diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, cyclohexanedimethanol diglycidyl ether, hydroquinone diglycidyl ether, N-glycidyl phthalimide, hydrogenated bisphenol A diglycidyl ether, sorbitol polyglycidyl ether, and pentaerythritol. Examples include polyglycidyl ether, glycerol polyglycidyl ether, polyglycerol polyglycidyl ether, trimethylpropane polyglycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, phenyl (polyethylene glycol) glycidyl ether, phenyl (polypropylene glycol) glycidyl ether, p-tert-butylphenyl glycidyl ether, diglycidyl-o-phthalate, diglycidyl terephthalate, dibromophenyl glycidyl ether, epoxidized vegetable oil, and polymers having a glycidyl group on the side chain.

[0078] Natural fats and oils are waxes whose main component is an ester compound of naturally occurring fatty acid and glycerin, and examples thereof include candelilla wax, carnauba wax, rice wax, beeswax, and sunflower wax.

[0079] Naturally derived fatty acid ester waxes are waxes whose main component is an ester compound of a naturally derived fatty acid and an alcohol other than glycerin, and examples include natural plant waxes (candelilla wax, carnauba wax, rice bran wax, Japan wax, etc.), natural animal waxes (beeswax, shellac wax, lanolin wax, spermaceti, etc.), and natural mineral waxes (montan wax, ozokerite, ceresin, etc.).

[0080] Synthetic waxes are waxes synthesized from monovalent or polyvalent (divalent to tetravalent) ester compounds of carboxylic acids having 2 to 34 carbon atoms (including the carbon atoms of the carboxyl group) and alcohols having 1 to 36 carbon atoms, and examples of such waxes include cetyl myristate, stearyl stearate, and behenyl behenate.

[0081] Examples of the amide compound include mono- or poly- (di- to tetra-) amide compounds which are reaction products of carboxylic acids having 2 to 34 carbon atoms (including the carbon atoms of the carboxyl group) (behenic acid, decanoic acid, sebacic acid, azelaic acid, dodecanedioic acid, 1,18-octadecanedicarboxylic acid, etc.) with amine compounds having 1 to 34 carbon atoms (hexamethylenediamine, norbornanediamine, 1,3-bisaminomethylcyclohexane, etc.). Mixtures of aliphatic amide compounds and fatty acid amides of animal and vegetable oils and fats may also be used.

[0082] Examples of urethane compounds other than polyurethane resins for coating granular agricultural materials include polyurethanes that do not contain polyester polyol (A1), polyether polyol (A2), or polyester polyether polyol (A3) as a constituent monomer.

[0083] Organo-clays are those obtained by ion-exchanging the interlayer cations of clay (layered silicates) with organic onium ions. Examples of clay (layered silicates) include smectite minerals (montmorillonite, hectorite, fluorine hectorite, saponite, etc.), mica, vermiculite, and brittle mica. Examples of organic onium ions used for ion exchange include primary ammonium ions, secondary ammonium ions, tertiary ammonium ions, amino acid derivatives, quaternary ammonium ions, organic phosphonium ions, organic pyridinium ions, and organic sulfonium ions.

[0084] The total content of the gradual solubility regulator (D) is preferably 40% by weight or less, more preferably 15% by weight or less, based on the weight of the polyurethane resin contained in the coating layer (II).

[0085] [Organic filler (F)] The coating layer (II) in the present invention may contain an organic filler (F) for the purposes of improving the biodegradability of the coating composition and adjusting the gradual dissolution of the drug (shortening the number of days for gradual dissolution). Specific examples of the organic filler (F) include starch such as cornstarch, modified starch, agar, and xanthone. The total content of the organic filler (F) is preferably 10% by weight or less, more preferably 5% by weight or less, based on the weight of the polyurethane resin contained in the coating layer (II).

[0086] The coating layer (II) may further contain other additives, etc., to the extent that the effects of the invention are not impaired. Examples of other functional agents include heat stabilizers, antioxidants, weather stabilizers, light stabilizers, ultraviolet absorbers, antistatic agents, slip agents, antiblocking agents, antifogging agents, neutralizing agents, metal deactivators, surfactants, compatibilizers, colorants, antibacterial and antifungal agents, flame retardants, plasticizers, dispersants, fillers, conductive agents, preservatives, fragrances, and insect repellents.

[0087] The composite particulate agricultural material of the present invention may have, in addition to the coating layer (II), a layer for controlling sustained release on at least a part of the surface of the granular agricultural chemical (N). The layer intended to control sustained release preferably contains a sustained release controlling material (I) such as minerals, sulfur, sugar, soybean flour, porous ceramics, natural rubber, oils and fats, and thermoplastic biodegradable resins. There are no restrictions on the arrangement of the coating layer (II) and the layer intended to control sustained release, and the coating layer (II) may be arranged on top of the layer intended to control sustained release, or the layer intended to control sustained release may be arranged on top of the coating layer (II), or the coating layer (II) and the layer intended to control sustained release may be arranged side by side on the surface of the granular agricultural material.

[0088] When the coating layer (II) is disposed on the layer containing the controlled-release material (I) for the purpose of controlling the controlled release, the coating layer (II) adheres strongly to the layer for the purpose of controlling the controlled release, making the coating layer (II) less likely to peel off from the surface of the granular agricultural material and further reducing the surface irregularities. As a result, it is presumed that the control function of the controlled release of the drug and the impact resistance are further improved.

[0089] Examples of the sustained-release controlling material (I) that constitutes the layer intended to control sustained release, such as minerals, sulfur, sugar, soybean flour, porous ceramics, natural rubber, oils and fats, and thermoplastic biodegradable resins, include the following. Examples of the mineral substances include kaolin minerals such as kaolinite, montmorillonite, smectite, talc, roseki, silica, calcium silicate hydrate, calcium carbonate, and zeolite. Examples of sugars include cellulose, starch, lactose, sucrose, and dextrin. Examples of natural rubber include nitrile rubber (acrylonitrile-butadiene rubber (NBR)), chloroprene rubber (CR), and styrene-butadiene rubber (SBR). Examples of natural fats and oils include waxes (such as candelilla wax, carnauba wax, rice wax, beeswax, and sunflower wax) whose main component is an ester compound of naturally occurring fatty acid and glycerin. As the thermoplastic biodegradable resin, those that have been given the biodegradable plastic mark by the Japan Bioplastics Association (JBPA) (such as polylactic acid, polyhydroxyalkanoic acid, cellulose acetate, polyvinyl alcohol, polyglycolic acid, polycaprolactone, polybutylene succinate, polybutylene succinate adipate, polybutylene adipate terephthalate, and polyethylene terephthalate succinate) can be preferably used. Among these, sulfur and a thermoplastic biodegradable resin are preferably used as the sustained-release controlled material (I).

[0090] In the case of a granular agricultural material having a layer other than the coating layer (II) for the purpose of controlling sustained release, the weight ratio [(N) / (I)] of the granular agricultural agent (N) to the sustained-release controlled material (I) is preferably 2 to 50 from the viewpoint of controlling the sustained release of the agricultural agent (N).

[0091] Layers other than the coating layer (II) intended for controlling sustained release may contain components other than the sustained-release controlling material (I) within the scope that does not impair the effects of the invention.

[0092] The layer for controlling the sustained release on the surface of the granular agricultural chemical (N) can be formed using a jet-type coating device or a rotary drum-type coating device.

[0093] <Method of manufacturing composite particles> The composite particulate agricultural material of the present invention can be obtained by coating at least a portion of the surface of a granular agricultural material with a coating layer (II). As the coating method, a known method can be used, for example, the following coating methods (1) to (3). (1) A method in which a polyurethane resin-forming composition is applied to the surface of granular agricultural material in a flowing or rolling state, and if necessary, the polyurethane resin-forming composition is heated and cured to form a coating layer (II). (2) A method in which either the polyol component (A) or the polyisocyanate component (B) is applied to the surface of granular agricultural material in a fluidized or rolling state, and then the remaining component is applied, and if necessary, heated and cured to form a coating layer (II). (3) A method in which the polyol component (A) and the polyisocyanate component (B) are applied separately and simultaneously to the surface of granular agricultural material in a fluidized or rolling state without mixing, and if necessary heated and cured to form a coating layer (II). The polyurethane resin-forming composition, polyol component (A) and polyisocyanate component (B) can be attached to the surface of the granular agricultural material using a known spray fluidizer, sprayer, etc., and the entire amount may be sprayed at once or in several portions (e.g., 2 to 5 times). The catalyst (C) and sustained-release regulator (D), which are used as needed, may be mixed with the polyurethane resin-forming composition, the polyol component (A) and the polyisocyanate component (B) and then applied, or may be applied separately. In the above (1) and (2), in order to bring the granular agricultural material into a fluidized or rolling state, a fluidized bed coating device, a rolling granulator, a pan-type rolling device, various stirring devices, etc. can be suitably used. The heating temperature when heating is carried out as necessary is preferably 25 to 70°C, more preferably 25 to 50°C, from the viewpoint of controlling the curing reaction and uniformity of the coating layer (reducing variations in the coverage).

[0094] The composite particle-type agricultural material of the present invention achieves high levels of both biodegradability of the coating layer and controlled sustained release of the agent, and also has excellent mechanical strength (impact resistance, etc.), making it extremely useful for a wide range of applications requiring sustained release in the fields of pharmaceuticals, agriculture, food additives, cosmetics, hygiene products, etc. In particular, it can be suitably used as agricultural chemicals (fertilizers, pesticides, pest control agents, etc.), algae control agents, and agents to prevent the adhesion of aquatic organisms, and is particularly useful as agricultural chemicals such as fertilizers. [Example]

[0095] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples.

[0096] [Manufacturing Example 1] A spouted fluidized bed coating device was charged with 1000 g of commercially available thiamethoxam granules (average particle size 1 mm, active ingredient thiamethoxam 0.5 wt%), a granular agricultural material. A solution of 65 g of aromatic polyester biodegradable resin (trade name "Ecoflex", manufactured by BASF) dissolved in 1000 g of tetrachloroethylene was sprayed onto the material, and the material was dried with hot air at 60°C to obtain a granular agricultural material (hereinafter referred to as coated particle (Y-1)) with a layer of aromatic polyester biodegradable resin, which is the sustained-release controlled material (I), formed on the surface.

[0097] [Manufacturing Example 2] A pan-type rolling device was charged with 1,000 g of commercially available granular nitrogen fertilizer [weight average particle diameter 5.0 mm], which is a granular agricultural material, and the temperature was adjusted to 50° C. While the temperature was adjusted to 50° C., 150 g of molten sulfur melted at 150° C. was sprayed onto the granular nitrogen fertilizer suspended in the device, and then cooled to 50° C. or below by applying cold air, thereby obtaining a granular agricultural material [coated particle (Y-2)] having a layer of sulfur, which is the controlled-release material (I), on its surface.

[0098] [Manufacturing Example 3] 50 g of palmitic acid and 40 g of the fungicide cinnamaldehyde were melt-mixed at 70°C, and 100 g of porous cellulose particles (trade name "Viscopal AH-2050L", manufactured by Rengo Co., Ltd., average particle size 2 mm) were gradually added and stirred until the mixture was no longer sticky, thereby obtaining a granular agricultural material (Y-3) in which palmitic acid and the fungicide cinnamaldehyde were impregnated into the pores of the porous cellulose.

[0099] [Manufacturing Example 4] A pan-type rolling device was charged with 1,000 g of commercially available granular nitrogen fertilizer [weight average particle diameter 5.0 mm], which is a granular agricultural material, and the temperature was adjusted to 60° C. While the temperature was adjusted to 60° C., 100 g of carnauba wax melted at 80° C. was sprayed onto the granular nitrogen fertilizer floating in the device, and then cooled to 50° C. or below by applying cold air, thereby obtaining a granular agricultural material [coated particle (Y-4)] having a layer made of carnauba wax, which is the sustained-release controlled material (I).

[0100] [Manufacturing Example 5] A separable stainless steel flask was charged with 100 parts by weight of propylene glycol and 175 parts by weight of adipic acid, and the mixture was stirred while passing nitrogen gas through it. The temperature was gradually raised under normal pressure, and the mixture was reacted for approximately 10 hours at 230°C. The pressure was then gradually reduced at the same temperature, and the mixture was reacted for 10 hours at 760 to 40 mmHg until the acid value of the reaction mixture became less than 3 mgKOH / g, thereby obtaining polyol (A11-1), a polyester diol of propylene glycol / adipic acid (molecular weight 2000, hydroxyl value 55 mgKOH / g, acid value less than 3 mgKOH / g).

[0101] [Manufacturing Example 6] Polyol (A11-2) (number average molecular weight 2000, hydroxyl value 60 mgKOH / g, acid value less than 3 mgKOH / g), which is a polyester diol of neopentyl glycol / adipic acid, was obtained in the same manner as in Production Example 5, except that 100 parts by weight of propylene glycol was replaced with 100 parts by weight of neopentyl glycol and the amount of adipic acid was changed from 175 parts by weight to 126 parts by weight.

[0102] [Manufacturing Example 7] Polyol (A11-3) (number average molecular weight 4000, hydroxyl value 30 mgKOH / g, acid value less than 3 mgKOH / g), which is a polyester diol of neopentyl glycol / adipic acid, was obtained in the same manner as in Production Example 5, except that 100 parts by weight of propylene glycol was replaced with 100 parts by weight of neopentyl glycol and the amount of adipic acid was changed from 175 parts by weight to 133 parts by weight.

[0103] [Manufacturing Example 8] Polyol (A11-4) (number average molecular weight 3000, hydroxyl value 38 mgKOH / g, acid value less than 3 mgKOH / g), which is a polyester diol of neopentyl glycol / succinic acid, was obtained in the same manner as in Production Example 5, except that 100 parts by weight of propylene glycol was replaced with 100 parts by weight of neopentyl glycol and 175 parts by weight of adipic acid was replaced with 106 parts by weight of succinic acid.

[0104] [Manufacturing Example 9] A separable stainless steel flask was charged with 100 parts by weight of 1,6-hexanediol and 170 parts by weight of sebacic acid, and the mixture was stirred while passing nitrogen gas through it. The temperature was gradually raised under normal pressure, and the mixture was reacted at 230°C for approximately 10 hours. The pressure was then gradually reduced at the same temperature, and the mixture was reacted at 760 to 40 mmHg for 10 hours to obtain polyol (A11-5), a polyester diol of hexanediol / sebacic acid (molecular weight 13,000, hydroxyl value 9 mgKOH / g, acid value less than 3 mgKOH / g).

[0105] [Manufacturing Example 10] A separable stainless steel flask was charged with 100 parts by weight of 2-methyl-1,3-propanediol and 154 parts by weight of adipic acid, and the mixture was stirred while passing nitrogen gas through it. The temperature was gradually raised under normal pressure and the mixture was allowed to react at 230°C for approximately 10 hours. The pressure was then gradually reduced at the same temperature, and the mixture was allowed to react for 10 hours at 760 to 40 mmHg until the acid value of the reaction mixture became less than 3 mgKOH / g, thereby obtaining polyol (A11-6), a polyester diol of 2-methyl-1,3-propanediol / adipic acid (molecular weight 4000, hydroxyl value 29 mgKOH / g, acid value less than 3 mgKOH / g).

[0106] [Manufacturing Example 11] Polyol (A31-1) (number average molecular weight 4000, hydroxyl value 32 mgKOH / g, acid value less than 3 mgKOH / g), which is a polyester polyether diol of polyethylene glycol / adipic acid, was obtained in the same manner as in Production Example 5, except that 100 parts by weight of propylene glycol was replaced with 100 parts by weight of polyethylene glycol 4000 [trade name "PEG-400", manufactured by Sanyo Chemical Industries, Ltd.] and the amount of adipic acid was changed from 175 parts by weight to 32 parts by weight.

[0107] [Manufacturing Example 12] Polyol (A31-2) (number average molecular weight 2000, hydroxyl value 58 mgKOH / g, acid value less than 3 mgKOH / g), which is a polyester polyether diol of polyethylene glycol / adipic acid, was obtained in the same manner as in Production Example 5, except that 100 parts by weight of propylene glycol was replaced with 100 parts by weight of polyethylene glycol 400 [trade name "PEG-400", manufactured by Sanyo Chemical Industries, Ltd.] and the amount of adipic acid was changed from 175 parts by weight to 27 parts by weight.

[0108] [Manufacturing Example 13] Polyol (A31-3) (number average molecular weight 4000, hydroxyl value 33 mgKOH / g, acid value less than 3 mgKOH / g), which is a polyester polyether diol of polyethylene glycol / adipic acid, was obtained in the same manner as in Production Example 5, except that 100 parts by weight of propylene glycol was replaced with 100 parts by weight of polyethylene glycol 1000 [trade name "PEG-1000", manufactured by Sanyo Chemical Industries, Ltd.] and the amount of adipic acid was changed from 175 parts by weight to 11 parts by weight.

[0109] [Manufacturing Example 14] Polyol (A31-4) (number average molecular weight 3000, hydroxyl value 37 mgKOH / g, acid value less than 3 mgKOH / g), which is a polyester polyether diol of polyethylene glycol / adipic acid, was obtained in the same manner as in Production Example 5, except that 100 parts by weight of propylene glycol was replaced with 200 parts by weight of polyethylene glycol 1000 [trade name "PEG-1000", manufactured by Sanyo Chemical Industries, Ltd.] and the amount of adipic acid was changed from 175 parts by weight to 19 parts by weight.

[0110] [Manufacturing Example 15] Polyol (A31-5) (number average molecular weight 4000, hydroxyl value 32 mgKOH / g, acid value less than 3 mgKOH / g), which is a polyester polyether diol of polypropylene glycol / adipic acid, was obtained in the same manner as in Production Example 5, except that 100 parts by weight of propylene glycol was replaced with 100 parts by weight of polypropylene glycol 400 [trade name "Sannyx PP400", manufactured by Sanyo Chemical Industries, Ltd.] and the amount of adipic acid was changed from 175 parts by weight to 32 parts by weight.

[0111] [Manufacturing Example 16] Polyol (A31-6) (number average molecular weight 3000, hydroxyl value 38 mgKOH / g, acid value less than 3 mgKOH / g), which is a polyester polyether diol of polypropylene glycol / adipic acid, was obtained in the same manner as in Production Example 5, except that 100 parts by weight of propylene glycol was replaced with 100 parts by weight of polypropylene glycol 400 [trade name "Sannyx PP400", manufactured by Sanyo Chemical Industries, Ltd.] and the amount of adipic acid was changed from 175 parts by weight to 30 parts by weight.

[0112] [Manufacturing Example 17] Polyol (A31-7) (number average molecular weight 4000, hydroxyl value 32 mgKOH / g, acid value less than 3 mgKOH / g), which is a polyester polyether diol of polypropylene glycol / adipic acid, was obtained in the same manner as in Production Example 5, except that 100 parts by weight of propylene glycol was replaced with 100 parts by weight of polypropylene glycol 1000 [trade name "Sannyx PP1000", manufactured by Sanyo Chemical Industries, Ltd.] and the amount of adipic acid was changed from 175 parts by weight to 11 parts by weight.

[0113] [Manufacturing Example 18] Polyol (A31-8) (number average molecular weight 3000, hydroxyl value 38 mgKOH / g, acid value less than 3 mgKOH / g), which is a polyester polyether diol of polypropylene glycol / adipic acid, was obtained in the same manner as in Production Example 5, except that 100 parts by weight of propylene glycol was replaced with 200 parts by weight of polypropylene glycol 1000 [trade name "Sannyx PP1000", manufactured by Sanyo Chemical Industries, Ltd.] and the amount of adipic acid was changed from 175 parts by weight to 19 parts by weight.

[0114] [Manufacturing Example 19] Polyol (A31-9) (number average molecular weight 4000, hydroxyl value 26 mgKOH / g, acid value less than 3 mgKOH / g), a polyester polyether diol of polypropylene glycol / malonic acid, was obtained in the same manner as in Production Example 5, except that 100 parts by weight of propylene glycol was replaced with 200 parts by weight of polypropylene glycol 1000 [trade name "Sannyx PP1000", manufactured by Sanyo Chemical Industries, Ltd.] and 175 parts by weight of adipic acid was replaced with 15.6 parts by weight of malonic acid.

[0115] [Manufacturing Example 20] Polyol (A31-10) (number average molecular weight 2000, hydroxyl value 53 mgKOH / g, acid value less than 3 mgKOH / g), which is a polyester polyether diol of polypropylene glycol / sebacic acid, was obtained in the same manner as in Production Example 5, except that 100 parts by weight of propylene glycol was replaced with 100 parts by weight of polypropylene glycol 400 [trade name "Sannyx PP400", manufactured by Sanyo Chemical Industries, Ltd.] and 175 parts by weight of adipic acid was replaced with 38 parts by weight of sebacic acid.

[0116] [Manufacturing Example 21] Polyol (A31-11) (number average molecular weight 1,300, hydroxyl value 85 mgKOH / g, acid value less than 3 mgKOH / g), which is a polyester polyether diol of polyethylene glycol / adipic acid, was obtained in the same manner as in Production Example 5, except that 100 parts by weight of propylene glycol was replaced with 100 parts by weight of polyethylene glycol 400 [trade name "PEG-400", manufactured by Sanyo Chemical Industries, Ltd.] and the amount of adipic acid was changed from 175 parts by weight to 24 parts by weight.

[0117] [Manufacturing Example 22] Polyol (A31-12) (number average molecular weight 4000, hydroxyl value 30 mgKOH / g, acid value less than 3 mgKOH / g), which is a polyester polyether diol of polyethylene glycol / adipic acid, was obtained in the same manner as in Production Example 5, except that 100 parts by weight of propylene glycol was replaced with 310 parts by weight of polyethylene glycol 400 [trade name "PEG-400", manufactured by Sanyo Chemical Industries, Ltd.] and 155 parts by weight of polypropylene glycol 200 [trade name "Sannyx PP200", manufactured by Sanyo Chemical Industries, Ltd.] and the amount of adipic acid was changed from 175 parts by weight to 206 parts by weight.

[0118] [Manufacturing Example 23] Polyol (A31-13) (number average molecular weight 4000, hydroxyl value 31 mgKOH / g, acid value less than 3 mgKOH / g), which is a polyester polyether diol of polyethylene glycol / adipic acid, was obtained in the same manner as in Production Example 5, except that 100 parts by weight of propylene glycol was replaced with 415 parts by weight of polyethylene glycol 400 [trade name "PEG-400", manufactured by Sanyo Chemical Industries, Ltd.] and 70 parts by weight of polypropylene glycol 200 [trade name "Sannyx PP200", manufactured by Sanyo Chemical Industries, Ltd.] and the amount of adipic acid was changed from 175 parts by weight to 181 parts by weight.

[0119] [Manufacturing Example 24] A stainless steel autoclave equipped with a thermometer and a stirrer was charged with 80 parts by weight of ethylene glycol and 175 parts by weight of adipic acid. The mixture was stirred while passing nitrogen gas through it. The temperature was gradually increased under normal pressure, and the reaction was continued for approximately 10 hours at 230°C. The pressure was then gradually reduced at the same temperature, and the reaction was continued for 10 hours at 760 to 40 mmHg until the acid value of the reaction mixture reached less than 3 mgKOH / g, yielding an ethylene glycol / adipic acid polyester diol. The autoclave was then cooled to 120°C, 0.01 parts by weight of sodium hydroxide was added, the autoclave was sealed, and the atmosphere was replaced with nitrogen. The autoclave was then heated to 150°C. 7 parts by weight of ethylene oxide (EO) was added and reacted at 150°C for 3 hours. After aging at 160°C for 1 hour, the mixture was cooled to 80°C and 50 parts by weight of xylene, 0.9 parts by weight of Radiolite #800 (manufactured by Showa Chemical Industry Co., Ltd.), and 0.8 parts by weight of Galleon Earth NV (manufactured by Mizusawa Industrial Chemicals Co., Ltd.) were added. After adsorption treatment at 80°C, the mixture was filtered and the xylene was removed at 130°C and 20 mmHg to obtain a polyester polyether polyol (A31-14) in which ethylene oxide was added to ethylene glycol / adipic acid (number average molecular weight 2000, hydroxyl value 54 mg KOH / g, acid value less than 3 mg KOH / g, and number of moles of ethylene oxide added 1.1).

[0120] [Manufacturing Example 25] Polyol (A32-1) (number average molecular weight 3,000, hydroxyl value 38 mgKOH / g, acid value less than 3 mgKOH / g), which is a polyester polyether diol of polyethylene glycol / adipic acid / terephthalic acid, was obtained in the same manner as in Production Example 5, except that 100 parts by weight of propylene glycol was replaced with 100 parts by weight of polyethylene glycol 400 [trade name "PEG-400" manufactured by Sanyo Chemical Industries, Ltd.], the amount of adipic acid charged was changed from 175 parts by weight to 14 parts by weight, and the amount of terephthalic acid was changed to 17 parts by weight.

[0121] [Manufacturing Example 26] Polyol (A32-2) (number average molecular weight 1200, hydroxyl value 130 mgKOH / g, acid value less than 3 mgKOH / g), which is a polyester polyether diol of polyethylene glycol / trimellitic acid, was obtained in the same manner as in Production Example 5, except that 100 parts by weight of propylene glycol was replaced with 100 parts by weight of polyethylene glycol 400 [trade name "PEG-400", manufactured by Sanyo Chemical Industries, Ltd.] and the amount of adipic acid was changed from 175 parts by weight to 18 parts by weight of trimellitic acid.

[0122] [Manufacturing Example 27] In a reaction vessel equipped with a condenser, a stirrer, and a nitrogen inlet, 700 parts by weight of sebacic acid, 410 parts by weight of 1,12-dodecanediol, 1-docosanol, and 0.5 parts by weight of titanium dihydroxybis(triethanolamine) as a condensation catalyst were placed and reacted at 160°C under a nitrogen stream for 6 hours while distilling off the water produced. The temperature was then gradually increased to 210°C, and the reaction was continued for 5 hours under a nitrogen stream while distilling off the water produced. The reaction was then continued under a reduced pressure of 0.5 to 3.5 kPa until the acid value of the reaction mixture reached less than 1 mgKOH / g, yielding a polyester monool (E-2) containing an aliphatic monool as a constituent monomer (number average molecular weight 13,000, hydroxyl value 85 mgKOH / g, acid value less than 1 mgKOH / g).

[0123] [Example 1: Production of composite particle-type agricultural material (X-1)] 1,000 parts by weight of urea particles (N-1) were placed in a pan-type rolling device rotating at 30 rpm and heated to 80°C. 3 parts by weight of diphenylmethane diisocyanate as an isocyanate component was sprayed onto the urea particles (N-1) rolling in the pan-type rolling device. Next, a mixture of polyol and catalyst was prepared by mixing 22 parts by weight of polyester polyol (A11-1) and 2 parts by weight of polyether polyol (A31-1) as polyol components and 0.02 parts by weight of catalyst (C-2) in a static mixer. The mixture was then sprayed onto the urea particles (N-1) while maintaining the temperature at 80°C. After spraying, the mixture was heated for an additional 10 minutes while rolling at 80°C to cure the polyurethane resin, yielding a composite particle-type agricultural material (X-1) having a coating layer (II) containing polyurethane resin (P-1).

[0124] [Examples 2 to 91, Comparative Examples 1 to 4] Polyurethane resin-forming compositions were prepared by mixing the polyol component (A), polyisocyanate component (B), catalyst (C), and gradual solubility modifier (D), aliphatic monool (E), and organic filler (F) in a static mixer according to the formulations (parts by weight) shown in Tables 1 to 10. These compositions were then sprayed onto the granular agricultural materials shown in Tables 1 to 10 in the same manner as in Example 1 to obtain polyurethane resins (P-2) to (P-91), composite particle-type agricultural materials (X-2) to (X-91) having coating layers (II) containing comparative polyurethane resins (comparison P-1) to (comparison P-4), and comparative particle-type agricultural materials (comparison X-1) to (comparison X-4).

[0125] Comparative Example 5 1,000 parts by weight of urea particles (N-1) were charged into a fluidized bed coating apparatus using a spouted bed, and the temperature was adjusted to 60°C. A solution of low-density polyethylene [trade name "UBE Polyethylene R300", manufactured by Ube Maruzen Co., Ltd. (density 0.92, MFR 0.35 g / min)] dissolved in tetrachloroethylene was sprayed from a spray nozzle onto the particles to be coated (Y-1) flowing inside the apparatus, and then heated to 60°C with hot air to remove the solvent, thereby obtaining a comparative particle-type agricultural material (Comparative X-5) having a coating layer made of low-density polyethylene.

[0126] [Table 1]

[0127] [Table 2]

[0128] [Table 3]

[0129] [Table 4]

[0130] [Table 5]

[0131] [Table 6]

[0132] [Table 7]

[0133] [Table 8]

[0134] [Table 9]

[0135] [Table 10]

[0136] The raw material symbols in Tables 1 to 10 are as follows:

[0137] <Polyol component (A)> <Polyester polyol (A1)> (A11-1): Polyester diol of propylene glycol / adipic acid (number average molecular weight 2000, hydroxyl value 55 mg KOH / g, acid value less than 3 mg KOH / g) [obtained in Production Example 5] (A11-2): Polyester diol of neopentyl glycol / adipic acid (number average molecular weight 2000, hydroxyl value 60 mg KOH / g, acid value less than 3 mg KOH / g) [obtained in Production Example 6] (A11-3): Polyester diol of neopentyl glycol / adipic acid (number average molecular weight 4000, hydroxyl value 30 mg KOH / g, acid value less than 3 mg KOH / g) [obtained in Production Example 7] (A11-4): Polyester diol of neopentyl glycol / succinic acid (number average molecular weight 3000, hydroxyl value 38 mg KOH / g, acid value less than 3 mg KOH / g) [obtained in Production Example 8] (A11-5): Polyester diol of hexanediol / sebacic acid (number average molecular weight 13,000, hydroxyl value 9 mg KOH / g, acid value less than 3 mg KOH / g [obtained in Production Example 9]) (A11-6): Polyester diol of 2-methyl-1,3-propanediol / adipic acid (number average molecular weight 4000, hydroxyl value 29 mg KOH / g, acid value less than 3 mg KOH / g) [obtained in Production Example 10] (Comparative Example A11-1): Polycaprolactone diol [product name "Placcel 205", manufactured by Daicel Chemical Industries, Ltd.] (number average molecular weight 530, hydroxyl value 213 mg KOH / g, acid value 0.08 mg KOH / g, melting point 30-40°C) (Comparative Example A11-2): Polycaprolactone diol [product name "Placcel 208", manufactured by Daicel Chemical Industries, Ltd.] (number average molecular weight 830, hydroxyl value 138 mg KOH / g, acid value 0.11 mg KOH / g, melting point 35-45°C)

[0138] <Polyether polyol (A2)> (A21-1): Polyethylene glycol 400 [product name "PEG-400", manufactured by Sanyo Chemical Industries, Ltd., freezing point: 6°C] (A21-2): Polypropylene glycol 1000 [product name "Sannyx PP1000", manufactured by Sanyo Chemical Industries, Ltd., freezing point: -31°C] (A23-1): Polyetheramine polyol [product name "Sannyx NP300", manufactured by Sanyo Chemical Industries, Ltd.]

[0139] <Polyester polyether polyol (A3)> (A31-1): Polyethylene glycol 400 [trade name "PEG-400", manufactured by Sanyo Chemical Industries, Ltd.] / polyester polyether diol of adipic acid (number average molecular weight 4000, hydroxyl value 32 mg KOH / g, acid value less than 3 mg KOH / g) [obtained in Production Example 11] (A31-2): Polyethylene glycol 400 [trade name "PEG-400", manufactured by Sanyo Chemical Industries, Ltd.] / polyester polyether diol of adipic acid (number average molecular weight 2000, hydroxyl value 58 mg KOH / g, acid value less than 3 mg KOH / g) [obtained in Production Example 12] (A31-3): Polyethylene glycol 1000 [trade name "PEG-1000", manufactured by Sanyo Chemical Industries, Ltd.] / polyester polyether diol of adipic acid (number average molecular weight 4000, hydroxyl value 33 mg KOH / g, acid value less than 3 mg KOH / g) [obtained in Production Example 13] (A31-4): Polyethylene glycol 1000 [trade name "PEG-1000", manufactured by Sanyo Chemical Industries, Ltd.] / polyester polyether diol of adipic acid (number average molecular weight 3000, hydroxyl value 37 mg KOH / g, acid value less than 3 mg KOH / g) [obtained in Production Example 14] (A31-5): Polypropylene glycol 400 [trade name "Sannyx PP400", manufactured by Sanyo Chemical Industries, Ltd.] / polyester polyether diol of adipic acid (number average molecular weight 4000, hydroxyl value 32 mg KOH / g, acid value less than 3 mg KOH / g) [obtained in Production Example 15] (A31-6): Polypropylene glycol 400 [trade name "Sannyx PP400", manufactured by Sanyo Chemical Industries, Ltd.] / polyester polyether diol of adipic acid (number average molecular weight 3000, hydroxyl value 38 mg KOH / g, acid value less than 3 mg KOH / g) [obtained in Production Example 16] (A31-7): Polypropylene glycol 1000 [trade name "Sannyx PP1000", manufactured by Sanyo Chemical Industries, Ltd.] / polyester polyether diol of adipic acid (number average molecular weight 4000, hydroxyl value 32 mg KOH / g, acid value less than 3 mg KOH / g) [obtained in Production Example 17] (A31-8): Polypropylene glycol 1000 [trade name "Sannyx PP1000", manufactured by Sanyo Chemical Industries, Ltd.] / polyester polyether diol of adipic acid (number average molecular weight 3000, hydroxyl value 38 mg KOH / g, acid value less than 3 mg KOH / g) [obtained in Production Example 18] (A31-9): Polypropylene glycol 1000 [trade name "Sannyx PP1000", manufactured by Sanyo Chemical Industries, Ltd.] / polyester polyether diol of malonic acid (number average molecular weight 4000, hydroxyl value 26 mg KOH / g, acid value less than 3 mg KOH / g) [obtained in Production Example 19] (A31-10): Polypropylene glycol 400 [trade name "Sannyx PP400", manufactured by Sanyo Chemical Industries, Ltd.] / polyester polyether diol of sebacic acid (number average molecular weight 2000, hydroxyl value 53 mg KOH / g, acid value less than 3 mg KOH / g) [obtained in Production Example 20] (A31-11): Polyethylene glycol 400 [trade name "PEG-400", manufactured by Sanyo Chemical Industries, Ltd.] / polyester polyether diol of adipic acid (number average molecular weight 1300, hydroxyl value 85 mg KOH / g, acid value less than 3 mg KOH / g [obtained in Production Example 21]) (A31-12): Polyester polyether diol of polyethylene glycol 400 [trade name "PEG-400", manufactured by Sanyo Chemical Industries, Ltd.] and polypropylene glycol 200 [trade name "Sannyx PP200", manufactured by Sanyo Chemical Industries, Ltd.] / adipic acid (number average molecular weight 4000, hydroxyl value 30 mg KOH / g, acid value less than 3 mg KOH / g [obtained in Production Example 22]) (A31-13): Polyester polyether diol of polyethylene glycol 400 [trade name "PEG-400", manufactured by Sanyo Chemical Industries, Ltd.] and polypropylene glycol 200 [trade name "Sannyx PP200", manufactured by Sanyo Chemical Industries, Ltd.] / adipic acid (number average molecular weight 4000, hydroxyl value 31 mg KOH / g, acid value less than 3 mg KOH / g [obtained in Production Example 23]) (A31-14): Polyester polyether polyol (number average molecular weight 2000, hydroxyl value 54 mg KOH / g, acid value less than 3 mg KOH / g) obtained by adding ethylene oxide to polyester polyol of ethylene glycol / adipic acid [obtained in Production Example 24] (A32-1): Polyethylene glycol 400 [trade name "PEG-400", manufactured by Sanyo Chemical Industries, Ltd.] / polyester polyether diol of adipic acid and terephthalic acid (number average molecular weight 3000, hydroxyl value 38 mg KOH / g, acid value less than 3 mg KOH / g) [obtained in Production Example 25] (A32-2): Polyethylene glycol 400 [trade name "PEG-400", manufactured by Sanyo Chemical Industries, Ltd.] / polyester polyether diol of trimellitic acid (number average molecular weight 1200, hydroxyl value 130 mg KOH / g, acid value less than 3 mg KOH / g) [obtained in Production Example 26]

[0140] <Polyisocyanate component (B)> (B-1): Diphenylmethane diisocyanate (NCO group content: 33.6% by weight) (B-2): Polymeric MDI [trade name "Millionate MR-200", manufactured by Tosoh Corporation, NCO group content: 31.0 wt%] (B-3): Hexamethylene diisocyanate [trade name "HDI24A-100 Biuret Type", manufactured by Asahi Kasei Corporation, NCO group content: 23.5% by weight] (B-4): Hexamethylene diisocyanate [trade name "D101", manufactured by Asahi Kasei Corporation, NCO group content: 19.7% by weight] (B-5): Naphthalene-1,5-diisocyanate [trade name "Ihara ND", manufactured by Kumiai Chemical Industry Co., Ltd., NCO group content 39.8% by weight]

[0141] (C-1): Triethylamine [Fujifilm Wako Pure Chemical Industries, Ltd., Wako special grade reagent] (C-2): Diazabicycloundecene [trade name "DBU", manufactured by San-Apro Co., Ltd.]

[0142] <Slow-dissolving adjuster (D)> (D-1): Carnauba wax [refined carnauba wax No. 1 powder, manufactured by Nippon Wax Co., Ltd.] (D-2): Paraffin wax ["PARAFFINWAX-155", manufactured by Nippon Seiro Co., Ltd., melting point 69°C, molecular weight 500]

[0143] <Aliphatic monool (E)> (E-1): Behenyl alcohol [Tokyo Chemical Industry Co., Ltd., melting point: 70°C] (E-2): Sebacic acid / 1,12-dodecanediol / 1-docosanol polyester monool (number average molecular weight 13,000, hydroxyl value 3 mg KOH / g, acid value less than 1 mg KOH / g) [obtained in Production Example 27]

[0144] <Organic filler (F)> (F-1): Rice starch [Fine Snow, manufactured by Joetsu Starch Co., Ltd.] <Granular agricultural chemicals (N)> (N-1): Urea (average particle size 4~5mm)

[0145] <Seed(S)> (S-1): Rice seeds (length 5-7 mm, width 3 mm)

[0146] The biodegradability of the coating layer, the average thickness of the coating layer, and the uniformity of the coating were measured using the following methods for each composite particle-type agricultural material (X) obtained in Examples 1 to 91 and the comparative composite particle-type agricultural materials (comparison X) obtained in Comparison Examples 1 to 5, and are shown in Tables 11 to 15. Furthermore, for Examples 1 to 86 and Comparative Examples 1 to 5, the coating properties (coating rate distribution), "sustained release of drug" and "impact resistance" were evaluated, and for Examples 87 to 91, the "germination properties" and "impact resistance" were evaluated, and the results are shown in Tables 11 to 15.

[0147] (1) Biodegradability of the coating layer The polyurethane resin-forming compositions used in Examples 1 to 91 and Comparative Examples 1 to 4 were heated to 40°C for 2 hours in the absence of granular agricultural materials to obtain sheet-like cured products (thickness 5 mm or less). The cured products were cut into 15 mm x 15 mm pieces, and the disintegration degree after 90 days at 60°C was measured under conditions in accordance with JIS K 6954. The results were evaluated according to the following criteria and are shown in Tables 11 to 15. The low-density polyethylene used in Comparative Example 5 was also prepared into a 15 mm x 15 mm sheet sample and tested. <Evaluation criteria> ☆: Biodegradability: 80% or more ◎: Biodegradability: 60% or more but less than 80% 〇: Biodegradability: 40% or more but less than 60% △: Biodegradability: 10% to less than 40% ×: Biodegradability: Less than 10%

[0148] (2) Average thickness of the coating layer and uniformity of the coating Each composite particle-type agricultural material (X) obtained in Examples 1 to 91 and the comparative composite particle-type agricultural material (comparison X) obtained in Comparative Examples 1 to 5 were cut into semicircular shapes with a razor, and the cut surfaces were subjected to platinum-palladium vapor deposition using a platinum vapor deposition machine (JEC-3000FC). The vapor-deposited cut surfaces were observed using a scanning electron microscope (JSM-7000, manufactured by JEOL Ltd.) at an acceleration voltage of 10 kV and a magnification of 100 times (measurement field of view: 1000 μm × 1000 μm) to measure the thickness of the coating film. The thickness of the coating film was measured at five points per coated particle, and the average value and standard deviation were calculated. The calculated average value was defined as the "average thickness of the coating layer (II)," and the standard deviation was evaluated according to the following criteria and shown as "uniformity of coating" in Tables 11 to 15. The smaller the standard deviation, the higher and more favorable the "uniformity of coating." [Evaluation criteria] ◎:Standard deviation: 3μm or less ○:Standard deviation: More than 3μm and less than 5μm △:Standard deviation: More than 5μm and less than 10μm ×:Standard deviation: more than 10μm

[0149] (3) Coverage (coverage distribution) The weight (W1, unit: g) of a single particle selected from each of the composite particle-type agricultural materials (X) and (comparison X) obtained in Examples 1 to 91 and Comparative Examples 1 to 5 was measured, and five holes were then made in the particle with a No. 11 sewing needle. The particle was then placed in a beaker containing 200 ml of ion-exchanged water and allowed to stand for 24 hours. After standing, the solid matter in the beaker was filtered and collected, washed with ion-exchanged water, and dried in a normal air dryer at 110°C for 90 minutes. The weight (W2, unit: g) of the remaining components after the chemical agent had eluted into the ion-exchanged water was measured, and the coverage rate of the particle {the ratio (%) of the weight of the remaining components to the weight of the chemical agent eluted} was calculated using the following formula. Coverage (%) = [W2 (g) / {W1 (g) - W2 (g)}] x 100 The coverage was calculated for a total of 10 particles, and a histogram was created from the coverage of the 10 particles to determine the standard deviation (σ). The closer this standard deviation (σ) is to 0, the narrower the distribution of coverage and the better the coverage. The coverage (coverage distribution) was classified according to the following criteria and listed in Tables 11 to 15. [Evaluation criteria] 〇: Standard deviation: 0~10% or less △:Standard deviation: More than 10% and less than 20% ×: Standard deviation: over 20%

[0150] (4) Sustained release of drugs Ten grams of each composite particulate agricultural material (X) obtained in Examples 1 to 86 and Comparative Examples 1 to 5 and 200 g of ion-exchanged water were placed in a sealable wide-mouth glass sample bottle and stored in a thermostatic chamber at 25°C. The ion-exchanged water was replaced with fresh ion-exchanged water every five days, and the amount of the chemical (N) in the replaced ion-exchanged water was quantitatively measured. The total amount of chemical (N) dissolved in the ion-exchanged water was calculated by adding up the amounts of chemical (N) dissolved every five days. The chemical (N) in the sample solution was quantified using spectrophotometry under the following measurement conditions for urea (Fertilizer Research Report Vol. 11 (2018), published by the National Center for Food and Agriculture, Forestry and Fisheries Consumer Safety). For thiamethoxam or cinnamaldehyde, the chemical (N) was quantified using liquid chromatography mass spectrometry (LC / MS) under the following measurement conditions. Storage in a thermostatic chamber at 25°C and replacement of ion-exchanged water were repeated until the ratio of the total dissolution amount calculated every 5 days to the dissolution amount when the entire amount of drug (N) was dissolved (hereinafter referred to as dissolution rate) reached 80% or more. The dissolution rate on the 5th day from the start of storage [initial dissolution rate (%)] and the number of days until the dissolution rate reached 80% or more [days to 80% dissolution (days)] are shown in Tables 11 to 15. A mixture of 10 g of drug (N) ground in a mortar and 200 g of ion-exchanged water was stored in a constant temperature bath at 25°C for 5 days, and the amount of drug (N) dissolved in the ion-exchanged water was taken as the amount of drug (N) dissolved if the entire amount of drug (N) was dissolved. The smaller the initial dissolution rate (%), the better the sustained release. The number of days for 80% dissolution is neither too short nor too long, and is too short if it is 9 days or less, and too long if it is 120 days or more. The number of days for 80% dissolution is preferably 10 days or more, 20 days or more, 30 days or more, and 50 days or more, in that order.

[0151] <Measurement conditions for spectrophotometry> Equipment: UV-2550 (Shimadzu Corporation) Luminescent reagent solution: p-dimethylaminobenzaldehyde Measurement wavelength: 425~430nm <Measurement conditions for liquid chromatography mass spectrometry> Equipment: LCMS-8030 (Shimadzu Corporation) Column: InertSustain C18 (silica gel particle diameter 2 μm, inner diameter 2.1 mm, length 100 mm) Column temperature: 40℃ Mobile phase A: 10 mM ammonium acetate aqueous solution / methanol = 80 / 20 Mobile phase B: methanol Flow rate: 0.2ml / min

[0152] (5-1) Impact resistance when dropped 500 g of each of the composite particulate agricultural materials (X) and (comparison X) obtained in Examples 1 to 86 and Comparative Examples 1 to 5 was spread on a concrete surface from a height of 100 cm above the ground using a shoulder-mounted electric spreader (product name "Brocas Jr.", manufactured by Mukai Kogyo Co., Ltd.) 50 g of the spread particles (X) was used as a sample to carry out the (4) sustained release test of the agent, and the initial dissolution rate (%) was measured and calculated. The value (ΔA1) was calculated by subtracting the initial elution rate when the product was not sprayed onto a concrete surface from the initial elution rate when the product was sprayed onto a concrete surface, and the value was classified according to the following criteria and shown in Tables 11 to 15 as the impact resistance when dropped. If cracks or chips occur in the coating layer, which is the outermost layer of the coated particles, due to the impact when they are spread on the concrete ground, the initial leaching rate will be greater than the initial leaching rate (%) when they are not spread on the concrete ground, so the smaller the value, the better the impact resistance against falls. [Evaluation criteria] ◎:ΔA1:0~5% or less ○:ΔA1: More than 5% and less than 10% △:ΔA1: More than 10% and less than 20% ×: ΔA1: Over 20%

[0153] (5-2) Impact resistance during low-temperature storage A drop bag test was conducted using the following procedure, simulating the storage temperature when the product is stored at low temperatures in a storehouse or the like and the impact (stacking, etc.) that the product would receive during handling during storage. The initial dissolution rate after the drop bag test was measured and compared with the initial dissolution rate before the test to evaluate the impact resistance after the low temperature storage test (after low temperature storage and the drop bag test). <Low temperature storage test> 50 g of each composite particulate agricultural material (X) and (comparison X) obtained in Examples 1 to 86 and Comparative Examples 1 to 5, which had been cooled at -18°C ± 3°C for 24 hours, was placed in a 1-L polyethylene bag, spread so that the particles were in a nearly single layer, and then attached to the bottom of a 20-L polyethylene bag containing 10 kg of composite particulate agricultural material (X) as a weight. This bag was then dropped vertically from a height of 2 m 10 times with the 1-L polyethylene bag attached side facing downwards. The 50 g of (X) remaining in the 1-L polyethylene bag after the drop bag test was used as a sample to conduct the (4) sustained release test for the drug, and the initial dissolution rate (%) was measured and calculated. <Difference in initial dissolution rate before and after low-temperature storage test ΔA2> The value (ΔA2) was calculated by subtracting the initial dissolution rate when the low-temperature storage test was not performed from the initial dissolution rate when the low-temperature storage test was performed, and the value was classified according to the following criteria and shown in Tables 11 to 15 as the impact resistance during low-temperature storage. If cracks or chips occur in the coating layer, which is the outermost layer of the composite particle, due to the impact received during the low-temperature storage test, the initial dissolution rate will be greater than the initial dissolution rate (%) of the composite particle-type agricultural material (X) before the low-temperature storage test. Therefore, the smaller ΔA2, the better the impact resistance during low-temperature storage. [Evaluation criteria] ◎:ΔA2:0~5% or less ○:ΔA2: More than 5% and less than 10% △:ΔA2: More than 10% and less than 20% ×:ΔA2:More than 20%

[0154] (6) Germination A sufficiently moistened filter paper was placed in a petri dish, and 50 grains of the composite particle-type agricultural material (X) obtained in Examples 87 to 91 were placed on top of it, and then the dish was left to stand in a thermo-hygrostat at a temperature of 25°C and a humidity of 80%. <1> Initial germination days The number of days until germination was confirmed in 10 or more of the 50 coated seeds was defined as the number of days to initial germination, and is shown in Table 15. The number of days to initial germination should not be too short or too long; 5 days or less is too short, and 120 days or more is too long. The number of days to initial germination is preferably more than 5 days, more than 20 days, and more than 50 days, in that order. <2> Days to 80% germination The number of days until germination was confirmed in 40 or more of the 50 coated particles was defined as the number of days to 80% germination, and is shown in Table 15. The number of days to 80% dissolution is not appropriate if it is too short or too long; 5 days or less is too short, and 120 days or more is too long. The number of days to initial germination is preferably more than 5 days, more than 20 days, and more than 50 days, in that order. <3> Germination control The smaller the difference between the number of days to initial germination and the number of days to 80% germination, the better the control of the germination period. Therefore, the test results were classified according to the following criteria and are shown in Table 14 as germination controllability. ◎: The difference between the number of days for initial germination and the number of days for 80% germination is more than 0 days and less than 5 days 〇: The difference between the number of days for initial germination and the number of days for 80% germination is more than 5 days and less than 10 days △: The difference between the number of days for initial germination and the number of days for 80% germination is more than 10 days and less than 20 days ×: The difference between the number of days for initial germination and the number of days for 80% germination is more than 20 days

[0155] (7) Impact resistance when dropped 500 g of each of the composite particulate agricultural materials (X) obtained in Examples 87 to 91 was spread on a concrete surface from a height of 100 cm above the ground using a shoulder-mounted electric spreader (product name "Brocas Jr.", manufactured by Mukai Kogyo Co., Ltd.) 50 g of the spread composite particulate agricultural material (X) was used as a sample, and the number of days to initial germination was measured and calculated in the same manner as in (6) Seed germination ability above. The value (ΔA3) was calculated by subtracting the number of days to initial germination when the product was not sprayed on a concrete surface from the number of days to initial germination when the product was sprayed on a concrete surface, and the value was classified according to the following criteria and shown in Table 15 as the impact resistance when dropped. If cracks or chips occur in the coating layer, which is the outermost layer of the coated particles, due to the impact when they are spread on a concrete surface, the number of days to initial germination will be longer than the number of days to initial germination if they are not spread on a concrete surface, so the smaller the value, the better the impact resistance against falling. [Evaluation criteria] ◎: 0 to 5% or less ○: More than 5% and less than 10% △: More than 10% but less than 20% ×: More than 20%

[0156] (8) Impact resistance when stored at low temperatures A drop bag test was conducted using the following procedure, simulating the storage temperature when the product is stored at low temperatures in a storehouse or the like and the impact (stacking, etc.) that the product would receive during handling during storage. The initial dissolution rate after the drop bag test was measured and compared with the initial dissolution rate before the test to evaluate the impact resistance after the low temperature storage test (after low temperature storage and the drop bag test). <Low temperature storage test> 50 g of each composite particulate agricultural material (X) and (comparison X) obtained in Examples 87 to 91, which had been cooled at -18°C ± 3°C for 24 hours, was placed in a 1-liter polyethylene bag, spread so that the particles were in a nearly single layer, and then attached to the bottom of a 20-liter polyethylene bag containing 10 kg of composite particulate agricultural material (X) as a weight. This bag was used as a test bag. The test bag, with the 1-liter polyethylene bag attached, was dropped vertically from a height of 2 m 10 times with the 50 g of (X) remaining in the 1-liter polyethylene bag facing downwards. The 50 g of (X) remaining in the 1-liter polyethylene bag after the drop bag test was used as a sample, and the number of days to initial germination was measured and calculated in the same manner as in (6) Seed germination above. <Difference in the number of days to initial germination before and after low-temperature storage test ΔA4> The value (ΔA4) was calculated by subtracting the number of days to initial germination when the low-temperature storage test was performed from the number of days to initial germination when the low-temperature storage test was not performed, and the value was classified according to the following criteria and shown in Table 15 as impact resistance. If cracks or chips occur in the coating layer due to the impact received during the low-temperature storage test, the number of days to initial germination will be longer than the number of days to initial germination if the low-temperature storage test is not performed. Therefore, the smaller ΔA4, the better the impact resistance during low-temperature storage. [Evaluation criteria] ◎:ΔA4:0~5% or less ○:ΔA4: More than 5% and less than 10% △:ΔA4: More than 10% and less than 20% ×: ΔA4: Over 20%

[0157] [Table 11]

[0158] [Table 12]

[0159] [Table 13]

[0160] [Table 14]

[0161] [Table 15]

[0162] The results in Tables 11 to 15 show that composite particle-type agricultural materials having a coating layer containing the polyurethane resin for coating granular agricultural materials of the present invention are good in all aspects, including the biodegradability of the coating layer, coating properties, control functions such as sustained release of pesticides, and impact resistance, and have superior properties compared to comparative agricultural materials. [Industrial Applicability]

[0163] The polyurethane resin for coating granular agricultural materials of the present invention achieves both high levels of biodegradability in the coating layer and control of the sustained release of chemicals, and also has excellent mechanical strength (such as impact resistance) and coating properties, making it useful for a wide range of applications requiring sustained release in fields such as agriculture, pharmaceuticals, food additives, cosmetics, and hygiene products. In particular, it can be suitably used as agricultural chemicals (fertilizers, pesticides, pest control agents, etc.), algae control agents, and agents to prevent the adhesion of aquatic organisms, and is particularly useful as a material for coating agricultural chemicals such as fertilizers.

Claims

1. A polyurethane resin for coating granular agricultural materials, which comprises a polyurethane resin that satisfies the following (1) to (3): (1) The polyol component (A), which is a constituent monomer of the polyurethane resin, is a polyol component containing a polyester polyol (A1) and a polyether polyol (A2), and / or a polyester polyether polyol (A3). (2) The total weight proportion of the polyester polyol (A1) and the polyester polyether polyol (A3) contained in the polyol component (A) is 80% by weight or more based on the weight of the polyol component (A). (3) The polyester polyol (A1) and the polyester polyether polyol (A3) each have a hydroxyl value of 5 to 130 mgKOH / g.

2. 2. The polyurethane resin for coating granular agricultural materials according to claim 1, wherein the number average molecular weight of the polyester polyol (A1) and the number average molecular weight of the polyester polyether polyol (A3) are each 1,000 to 8,000.

3. 3. A composite particulate agricultural material having a coating layer comprising the polyurethane resin for coating granular agricultural materials according to claim 1 or 2 on at least a portion of the surface of the granular agricultural material.

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