JP2021088499A - Coated granular chemicals for agriculture, forestry and horticulture - Google Patents

Abstract

To provide a coated granular chemical for agriculture, forestry and horticulture, the coating layer of which is less likely to be destroyed even if it becomes dry after absorption of water and release of the chemical, and the effect of the chemical such as plant growth can last for a longer period of time without being affected by the weather.SOLUTION: A coated granular chemical for agriculture, forestry and horticulture having a coating layer covering at least a part of the surface of the granule (P0), wherein the coating layer comprises a bioactive substance (E) and a temperature-responsive crosslinked resin particles (A), the lower critical solution temperature to water of the crosslinked resin being 10-40°C.SELECTED DRAWING: None

Description

The present invention relates to a coated type agricultural, forestry and horticultural granular drug whose surface is coated with a resin composition.

Granular chemicals used for agriculture, forestry and horticulture such as fertilizers and coatings are sprayed on agricultural land and the like. Then, for the purpose of enhancing the effect of the drug, the elution behavior of the drug is adjusted by coating with a coating agent such as a resin. For example, as a coated granular fertilizer having a high elution rate in the late elution stage and an improved elution rate in the early stage of elution, a urethane resin composed of a specific polyol component and an isocyanate component, and particles composed of sodium polyacrylate which is a highly water-absorbent resin. A coated granular fertilizer coated with is known (Patent Document 1).

The highly water-absorbent resin contained in the coating layer of the coated granular fertilizer described in Patent Document 1 has a function of absorbing water to promote dissolution and elution of the fertilizer. However, when it absorbs water, it expands and its volume changes significantly. Therefore, when it dries after absorbing water, the coating layer responsible for adjusting the elution behavior may be destroyed. Therefore, there is a problem that it is easily affected by the weather such as rainy weather after spraying, and it is difficult to exert the effect of the chemicals such as plant growth for a long period of time.

Japanese Unexamined Patent Publication No. 2010-20482

INDUSTRIAL APPLICABILITY According to the present invention, even if the coating layer is not easily destroyed even if it becomes dry after absorbing water once and releasing the chemical, it is possible to exert the effect of growing plants for a long period of time without being affected by the weather or the like. An object of the present invention is to provide a coated granular chemical for agriculture, forestry and horticulture.

The present inventors have arrived at the present invention as a result of studies for achieving the above object. That is, the present invention is a coated agricultural, forestry and gardening granular drug having a coating layer that covers at least a part of the particle surface of the particles (P0) containing the bioactive substance (E), and the coating layer is the lower limit criticality with respect to water. It is a coated granular chemical for agriculture, forestry and gardening containing temperature-responsive crosslinked resin particles (A) and a coating resin (C) having a solution temperature of 10 to 40 ° C.

According to the present invention, a coated type agricultural, forestry and horticultural granular drug capable of adjusting the elution rate over a long period of time, in which the coating layer is less likely to be destroyed even if the coating layer becomes dry again after water absorption has started and the release of the drug has started. Can be provided.

The coated granular agent for agriculture, forestry and horticulture of the present invention is a coated granular agent for agriculture, forestry and horticulture having a coating layer that covers at least a part of the particle surface of the particles (P0) containing the bioactive substance (E). The layer is a coated agricultural, forestry and horticultural granular chemical containing temperature-responsive crosslinked resin particles (A) and a coating resin (C) having a lower limit critical solution temperature of 10 to 40 ° C. with respect to water.

The bioactive substance (E) means a substance that acts on a certain living body (including fungi, animals, plants, etc.), and includes an active ingredient of a drug used for agriculture, forestry, and horticulture. Chemicals used for agriculture, forestry and horticulture include known granular chemicals used for the purpose of growing and protecting plants such as agricultural crops and useful plants, and used as fertilizers and pesticides.

The biologically active substance (E) is not limited as long as it is a substance having activity on living organisms, but is known when the particles (P0) are chemicals (fertilizers, etc.) for the purpose of growing plants. Examples of active substances contained in fertilizers include plant essential elements (calcium, magnesium, sulfur, iron, trace elements and silicon, etc.) and bioactive substances contained in nitrogenous fertilizers (ammonia sulfate, Urea, ammonia nitrate, isobutylaldehyde condensed urea, acetaldehyde condensed urea, etc.), bioactive substances contained in phosphoric acid fertilizers (lime perphosphate, molten phosphorus fertilizer, calcined phosphorus fertilizer, etc.), and bioactivity contained in caliper fertilizer. Examples include substances (kari sulfate, kari chloride, kari silicate, etc.).

When the particles (P0) are chemicals (pesticides, repellents, herbicides, etc.) for the purpose of protecting plants, the bioactive substances (E) include disease control agents, pest control agents, and pest control agents. , Bioactive substances contained in known pesticides such as weed control agents and plant growth regulators. The disease control agent is a drug used to protect crops and the like from the harmful effects of pathogenic microorganisms, and mainly includes fungicides. The pest control agent is an agent that controls pests that harm crops and the like, and mainly includes pesticides. Pest control agents are agents used to control plant-parasitic mites, plant-parasitic nematodes, wild rats, birds, and other harmful animals that damage crops and the like. Weed control agents are chemicals used to control plants and plants that are harmful to crops and trees, and are also called herbicides. A plant growth regulator is a drug used for the purpose of enhancing or suppressing the physiological function of a plant, and is also called a biostimulant.

Examples of the bioactive substance (E) contained in the pesticides and the like include 1- (6-chloro-3-pyridylmethyl) -N-nitroimidazolidine-2-iridenamine (generic name: imidacloprid), o, o-diethyl-S. -2- (Ethylthio) Ethylphosphologithioate (generic name: ethylthiomethone), 2,3-dihydro-2,2-dimethyl-7-benzo [b] furanyl = N-dibutylaminothio-N-methylcarbamate ( Generic name: Carbosulfan), (E) -N- (6-chloro-3-pyridylmethyl) -N-ethyl-N'-methyl-2-nitrovinylidenediamine (generic name: nitempirum), (±)- 5-Amino- (2,6-dichloro-α, α, α-trifluoro-p-toluyl) -4-trifluoromethylsulfinylpyrazole-3-carbonitrile (generic name: fipronyl), butyl = 2,3- Dihydro-2,2-dimethylbenzofuran-7-yl = N, N'-dimethyl-N, N'-thiodicarbamate (generic name: fratiocarb), ethyl = N- [2,3-dihydro-2,2 -Dimethylbenzofuran-7-yloxycarbonyl (methyl) aminothio] -N-isopropyl-β-alaninate (generic name: benfracarb), 1-naphthyl-N-methylcarbamate (generic name: NAC), (1RS, 3SR)- 2,2-Dichloro-N- [1- (4-chlorophenyl) ethyl] -1-ethyl-3-methylcyclopropanecarboxamide (generic name: carpropamide), (RS) -2-cyano-N-[(R) -1- (2,4-dichlorophenyl) ethyl] -3,3-dimethylbutyramide (generic name: diclosimet), 5-methyl-1,2,4-triazolo [3,4-b] benzothiazole (generic name) : Tricyclazole), 1,2,5,6-tetrahydropyrro [3,2,1-ij] quinoline-4-one (generic name: pyroquilon), (RS) -5-chloro-N- (1,3-) Dihydro-1,1,3-trimethylisobenzofuran-4-yl) -1,3-dimethylpyrazole-4-carboxamide (generic name: flametopyl), 3-allyloxy-1,2-benzoisothiazole-1,1- Dioxide (generic name: probenazole), 2-chloro-4-ethylamino-6-isopropylamino-s-triazine (generic name: atrazin), 1- (2-chloroimidazole [1,2-a] pyridine-3-3 Ilsulfonyl) -3- (4,6-dimethoxypi) Limidin-2-ylurea (generic name: imazosulfuron), S-benzyl = 1,2-dimethylpropyl (ethyl) thiocarbamate (generic name: esprocarb), ethyl = (RS) -2- [4- (6- (6-) Chloroquinoxalin-2-yloxy) phenoxy] propionate (generic name: xarohopbutyl), butyl = (R) -2- [4- (4-cyano-2-fluorophenoxy) phenoxy] propionate (generic name: si) Halohopbutyl), 2-methylthio-4-ethylamino-6- (1,2-dimethylpropylamino) -s-triazine (generic name: dimetamethrin), 2-methylthio-4,6-bis (ethylamino)- s-triazine (generic name: simethrin), 1- (α, α-dimethylbenzyl) -3- (paratril) urea (generic name: dimulon), 2-chloro-N- (3-methoxy-2-thenyl)- 2', 6'-dimethylacetanilide (generic name: tenylchlor), α- (2-naphthoxy) propionanilide (generic name: naproanilide), methyl = 3-chloro-5- (4,6-dimethoxypyrimidine-2-i) Lucarbamoyl sulfamoyl) -1-methylpyrazole-4-carboxylate (generic name: halosulfuron-methyl), ethyl = 5- (4,6-dimethoxypyrimidine-2-ylcarbamoyl sulfamoyl) -1-methylpyrazole- 4-carboxylate (generic name: pyrazosulfuron ethyl), S- (4-chlorobenzyl) -N, N-diethylthiocarbamate (generic name: ventiocurve), methyl = α- (4,6-dimethoxypyrimidine-2) -Ilcarbamoyl sulfamoyl) -o-toluart (generic name: benzulfone methyl), 2-benzothiazole-2-yloxy-N-methylacetanilide (generic name: mephenacet) and the like can be mentioned.

As the biologically active substance (E) contained in the particles (P0), only one kind may be used, or two or more kinds of components may be used in combination, and when two or more kinds are used in combination, the biological activity contained in the fertilizer The substance (E) and the bioactive substance (E) contained in the pesticide may be used in combination.

The particle size of the particles (P0) containing the bioactive substance (E) is not particularly limited, but the number average particle size is preferably 0.3 to 15 mm.
Among them, when the coated granular chemical for agriculture, forestry and horticulture of the present invention is used as a fertilizer, it is preferably 1.0 to 11.0 mm from the viewpoint of handleability such as less dust generation, and when it is used as a pesticide. It is preferably 0.3 to 3.0 mm from the viewpoint of handleability such as less dust generation.
The number average particle size of the particles (P0) is determined by observing the particles of the bioactive substance (E) with a digital microscope (for example, VHX-200 manufactured by KEYENCE CORPORATION) and performing image processing according to JIS 8827-1. Can be measured by.

The particles (P0) containing the bioactive substance (E) are preferably solid particles at room temperature (preferably 5 to 40 ° C.). Further, in the present invention, the particles (P0) can be used regardless of whether they are water-soluble, poorly water-soluble, or water-insoluble.

Examples of the particles (P0) containing the bioactive substance (E) include a single crystal of the bioactive substance (E), a granularly formed bioactive substance (E), and a pulverized product of the solidified bioactive substance (E). Can be used.

As the particles (P0) containing the bioactive substance (E), particles granulated from the bioactive substance (E) and inorganic fine particles, a binder resin, or the like can be used. The particles granulated by the bioactive substance (E) and the inorganic fine particles, the binder resin, or the like include the particles obtained by binding the particles of the bioactive substance (E) with the binder resin and granulating, and the biological activity. Particles obtained by binding inorganic fine particles to which the substance (E) is adsorbed with a binder resin and granulating can be used.

When the particles (P0) are granulated particles, clay, kaolin, talc, bentonite, calcium carbonate and the like can be used as the inorganic fine particles, and polyvinyl alcohol, sodium carboxymethyl cellulose, starch and the like can be used as the binder resin. be able to. In addition, the granulated particles include surfactants such as polyoxyethylene nonylphenyl ether and known additives such as waste sugar honey, animal oil, vegetable oil, hydrogenated oil, fatty acid, fatty acid metal salt, paraffin, wax and glycerin. May be.

The covered agricultural, forestry and horticultural granular drug of the present invention has a coating layer on at least a part of the particle surface of the particles (P0) containing the bioactive substance (E). Having a coating layer can be confirmed by the method described in the method for producing a coated granular chemical for agriculture, forestry and horticulture, which will be described later.

The coating layer contained in the coated granular chemicals for agriculture, forestry and gardening of the present invention contains the temperature-responsive crosslinked resin particles (A) having a lower limit critical solution temperature with respect to water of 10 to 40 ° C., and the temperature-responsive resin particles (A). ) Are particles made of a temperature-responsive crosslinked resin having a lower limit critical solution temperature of 10 to 40 ° C. with respect to water.
The temperature-responsive resin is a resin whose solubility in water changes dramatically due to a temperature change, and in particular, when it is a resin having no crosslinked structure and having a lower limit critical solution concentration (also referred to as LCST). It dissolves in water at a temperature lower than LCST, but has the property of becoming insoluble in water and precipitating when the temperature rises to LCST. The crosslinked resin obtained by copolymerizing a constituent monomer of a temperature-responsive resin that changes from a dissolved state to an insolubilized state with a crosslinking agent at a temperature lower than LCST absorbs water and swells to hydro. When a gel is formed and the temperature of the hydrogel is higher than that of LCST, the property of discharging (also referred to as dehydration) the absorbed water is exhibited. A hydrogel whose state changes at the boundary of LCST in this way is called a temperature-sensitive hydrogel.
The "temperature-responsive crosslinked resin particles (A) having an LCST of 10 to 40 ° C." used in the present invention are defined as a water-containing state to a dehydrated state (or a dehydrated state to a water-containing state) with the LCST at 10 to 40 ° C. as a boundary. It is a particle made of a crosslinked resin that forms a hydrogel that changes its state.

Since the coated granular chemical for agriculture, forestry and horticulture of the present invention contains the temperature-responsive crosslinked resin particles (A) that absorb water to form a temperature-sensitive hydrogel in the coating layer, it absorbs water at a temperature lower than LCST. Has a function of promoting dissolution and elution of the bioactive substance (E). Not only that, the coating layer is not destroyed when it becomes dry after absorbing water once, so that it is a coating-type granular chemical for agriculture, forestry and horticulture that can exert effects such as plant growth for a long period of time.

In the coated granular chemicals for agriculture, forestry and gardening of the present invention, by containing the temperature-responsive crosslinked resin particles (A) having a lower limit critical solution temperature of 10 to 40 ° C., the coating layer is dried after absorbing water. Although it is not clear why the breakage is unlikely to occur, the temperature-sensitive hydrogel formed from the temperature-responsive crosslinked resin particles (A) is formed by the association formation of hydrophobic groups contained in the skeleton of the temperature-responsive resin. Since water is discharged while contracting, one reason is considered to be that the change in particle size between before water absorption and after water absorption and then drying again is small. On the other hand, since the sodium polyacrylate polymer particles used in the prior art do not have a hydrophobic group, shrinkage force due to association formation does not occur, and the coating layer is destroyed when the volume is increased by water absorption and swelling and remains in a dry state. It is considered to be one of the reasons why it is likely to occur.

As the temperature-responsive crosslinked fat particles (A), only one type of temperature-responsive crosslinked resin particles may be used as long as the LCST is 10 to 40 ° C., and two or more types of temperature-responsive crosslinked resin particles having different LCSTs may be used. Crosslinked resin particles may be used. If the LCST is lower than 10 ° C., it becomes insolubilized at the environmental temperature at which the plant grows, so that the irrigated water is not absorbed and the release of the chemical cannot be adjusted. Further, if the LCST exceeds 40 ° C., the destruction of the coating layer due to drying after water absorption cannot be sufficiently suppressed.
In the present invention, the LCST measures the light transmittance (wavelength 670 nm) when a 1.0 wt% aqueous solution of the temperature-responsive crosslinked resin particles (A) is heated to 5 to 60 ° C. with a UV-vis spectrophotometer (for example). , UV-2550, manufactured by Shimadzu Corporation, the temperature at which the transmittance is 50%.

In addition, the coated agricultural, forestry and horticultural granular chemicals of the present invention can suppress the dependence of the elution behavior of the bioactive substance (E) on the environmental temperature by adjusting the LCST of the temperature-responsive crosslinked resin particles (A).
In the coating fertilizer containing the water-absorbent resin particles in the coating layer, the bioactive substance (E) is dissolved by the water absorbed by the water-absorbent resin particles, and many bioactive substances (a large amount of the bioactive substance () from the gelled water-absorbent resin particle portion. It is considered that E) elutes. Generally, when the temperature is different, the solubility of the bioactive substance (E) in water also changes, so the elution behavior of the bioactive substance (E) is dependent on the environmental temperature, and especially when the temperature rises, it is more than expected. In some cases, the bioactive substance (E) elutes, making it difficult to exert the effect for a predetermined period of time.
However, the coated agricultural, forestry and horticultural granular chemicals of the present invention containing the temperature-responsive crosslinked resin particles (A) as the water-absorbent resin particles include the bioactive substance (E) due to water absorbed at a temperature lower than LCST. Dissolution and release occur, but when the LCST is exceeded, water that dissolves the bioactive substance (E) is discharged, so that the dissolution and release of the bioactive substance (E) is suppressed and the effect can be exhibited for a longer period of time. it can.
As a method for adjusting the dependence of the elution behavior of the bioactive substance (E) on the environmental temperature, a method using a specific LCST as the temperature-responsive crosslinked resin particles (A) and two or more types of temperature-responsive crosslinks having different LCSTs are used. Examples thereof include a method using resin particles (A). When the elution rate is suppressed when the temperature reaches a high temperature region (more than 25 ° C. and 40 ° C. or lower), temperature-responsive resin particles having an LCST of 25 to 35 ° C. can be preferably used, and a low temperature region (10 ° C. or higher) can be used. When the elution rate is suppressed at (less than 25 ° C.), temperature-responsive resin particles having an LCST of 15 to 25 ° C. can be preferably used.

The elution behavior of the bioactive substance (E) in the high temperature region is the number of days when the elution rate of the bioactive substance (E) reaches 80% when the granular drug is placed in water at 35 ° C. (hereinafter referred to as D35). The ratio of D25 to D35 (depending on the temperature at high temperature) using the number of days when the elution rate of the bioactive substance (E) reaches 80% when the granular drug is placed in water at 25 ° C. (hereinafter referred to as D25). It can be evaluated by calculating [(D25) / (D35)] (which may be described as an exponent). The closer the high temperature temperature dependence index is to 1, the smaller the dependence of the elution amount on the temperature is, and the high temperature temperature dependence index is preferably 0.5 to 2.0, preferably 0.8 to 0.8. It is more preferably 1.5.

The elution behavior of the bioactive substance (E) in the low temperature region is the number of days when the elution rate of the bioactive substance (E) reaches 80% when the granular drug is placed in the water of D25 and 15 ° C. (hereinafter referred to as D15). It can be evaluated by calculating the ratio of D15 to D25 (sometimes referred to as a low temperature temperature dependence index) [(D15) / (D25)]. The closer the low temperature temperature dependence index is to 1, the smaller the dependence of the elution amount on the temperature is, and the low temperature temperature dependence index is preferably 0.5 to 2.0, preferably 0.8 to 0.8. It is more preferably 1.5.

The elution rate of the bioactive substance (E) from the coated granular chemicals for agriculture, forestry and horticulture is calculated by the following method.
10 g of the coated granular chemical for agriculture, forestry and horticulture of the present invention was allowed to stand on the bottom of a glass container having a volume of 250 mL, 200 mL of water adjusted to 15 ° C., 25 ° C. or 35 ° C. was poured into each of the glass containers, and the lid of the glass container was closed. It is closed and allowed to stand in a small environmental tester (for example, SU-222 manufactured by Espec Co., Ltd.) set at 15 ° C., 25 ° C. or 35 ° C. according to the temperature of water in a glass container. The amount of the bioactive substance (E) contained in the aqueous solution of the glass container is quantified at regular intervals, and the eluted biological activity with respect to the amount (g) of the bioactive substance (E) contained in 10 g of the coated granular drug for agriculture, forestry and gardening. The ratio of the amount (g) of the substance (E) [elution rate (%) of the bioactive substance (E)] is calculated, and the number of days when the dissolution rate becomes 80% is defined as D15, D25 and D35, respectively.

The amount of the bioactive substance (E) contained in the aqueous solution of the glass container may be quantified by a method according to the type of the bioactive substance (E), and when the bioactive substance (E) is urea, it is in water. Urea absorption wavelength using a commercially available kit (eg, QuantiChrom Urea Assay Kit II from BioAssy Systems) and a spectrophotometer (eg, PowerWave XS from BioTEK Instruments) to measure the urea concentration of ), And it can be quantified by comparing the absorbance of an aqueous urea solution with a known concentration.

The temperature-responsive crosslinked resin constituting the temperature-responsive resin particles (A) having a lower limit critical solution temperature with respect to water of 10 to 40 ° C. can be used without limitation as long as it is a crosslinked resin having water absorption and a predetermined LCST. , N-alkyl (meth) acrylamide, N-vinylalkylamide, N-ethoxyethyl (meth) acrylamide, a crosslinked resin containing alkylvinyl ether, etc. as constituent monomers, a crosslinked product of water-soluble cellulose ether (methylcellulose, etc.), etc. Can be given. In addition, "(meth) acrylic" in this specification means "acrylic" or "methacryl".

The temperature-responsive crosslinked resin particles (A) having a lower limit critical solution temperature in the range of 10 to 40 ° C. have an alkyl group having 2 to 12 carbon atoms (preferably) from the viewpoint of elution behavior of the bioactive substance (E). Contains particles composed of alkyl (meth) acrylamide (a1) and / or N-vinylalkylamide (a2) which are 2 to 6) and a resin (A1) containing a cross-linking agent (c) as an essential constituent monomer. The resin (A1) is more preferably a resin containing an alkyl (meth) acrylamide (a1) and a cross-linking agent (c) as essential constituent monomers. The alkyl (meth) acrylamide (a1) and the N-vinylalkylamide (a2) may be one kind or more.

As the alkyl (meth) acrylamide (a1), one hydrogen atom bonded to the nitrogen atom of acrylamide or methacrylicamide is substituted with an alkyl group, or two hydrogen atoms are substituted with an alkyl group, respectively. Alkyl groups include linear, branched or cyclic alkyl groups having 2 to 6 carbon atoms, and when two hydrogen atoms are substituted, they are mutually exclusive. They may be bonded to form a cyclic structure (a heterocyclic structure containing a nitrogen atom). Preferred alkyl (meth) acrylamide (a1) are N-isopropylacrylamide [LCST = 31-32 ° C], N, N'-diethylacrylamide [LCST = about 25 ° C], N-n-propylacrylamide [LCST]. = 22 ° C.], N-methyl-Nn-propylacrylamide [LCST = 20 ° C.], N-acrylicpyrrolidin [LCST = 58 ° C.], N-cyclopropylacrylamide [LCST = about 46 ° C.] and Nn- Examples thereof include propylmethacrylamide [LCST = 28 ° C.], and N-isopropylacrylamide and N, N'-diethylacrylamide are more preferable, and N-isopropylacrylamide is more preferable.
Examples of N-vinylalkylamide (a2) include N-vinylnormal propylamide (N-vinyl-n-propylamide) [LCST = about 32 ° C], N-vinylisopropylamide [LCST = about 39 ° C], and N-vinyl. Examples thereof include −n-butylamide [LCST = 32 ° C.] and N-vinylisobutyramide [LCST = 39 ° C.], and N-vinylnormalpropylamide is preferable. The value of LCST described in square brackets following the compound name is the LCST of the homopolymer.

For example, poly (N-isopropylacrylamide) obtained by homopolymerizing N-isopropylacrylamide dissolves in water on the lower temperature side than 32 ° C., becomes insoluble on the higher temperature side, and does not absorb water. Therefore, when a hydrogel is prepared by using particles made of a crosslinked resin containing N-isopropylacrylamide and a crosslinking agent (c) as constituent monomers as temperature-responsive crosslinked resin particles (A), the hydrogel exceeds 32 ° C. When used as a constituent component of a coating agent for granular chemicals for agriculture, forestry and gardening, it is considered that an increase in the elution rate of the bioactive substance (E) in a region exceeding 32 ° C. can be suppressed.

The LCST can be adjusted by changing the number of carbon atoms of the alkyl group in alkyl (meth) acrylamide (a1) and N-vinylalkylamide (a2), for example, N-normal-propylacrylamide and a cross-linking agent (c). ) Is a constituent monomer, and the LCST of the cross-linked resin containing N-vinylnormal propylamide and the cross-linking agent (c) is about 32 ° C. .. The LCST of N-alkyl (meth) acrylamide (a1) and N-vinylalkylamide (a2) can be adjusted by using two or more of them in combination, thereby adjusting the elution behavior.

The cross-linking agent (c) preferably includes a cross-linking agent having two or more radically polymerizable unsaturated groups, and more preferably N, N'-methylenebis (meth) acrylamide, ethylene glycol di (meth) acrylate, and polyethylene glycol. Di (meth) acrylate, propylene glycol di (meth) acrylate, glycerin di (meth) acrylate, glycerin tri (meth) acrylate, trimethyl propantri (meth) acrylate, triallylamine, triallyl cyanurate, triallyl isocyanurate, Examples thereof include tetraaryloxyethane and pentaerythritol triallyl ether. Of these, N, N'-methylenebis (meth) acrylamide and pentaerythritol triaryl ether are more preferable, and N, N'-methylenebis (meth) acrylamide is particularly preferable.

In the resin (A1) containing alkyl (meth) acrylamide (a1) and / or vinylalkylamide (a2) and the cross-linking agent (c) as essential constituent monomers, N-alkyl (meth) acrylamide (a1) and N- The total amount of vinylalkylamide (a2) used is preferably 50 to 99.9% by weight, preferably 98.0 to 99.8% by weight, based on the total weight of the constituent monomers of the temperature-responsive crosslinked resin particles (A). Is even more preferable. Weight ratio of the total weight of N-alkyl (meth) acrylamide (a1) and N-vinylalkylamide (a2) in the constituent monomer to the weight of the cross-linking agent (c) [{(a1) + (a2)} / [C]] is preferably 95/5 to 99.9 / 0.1, more preferably 96/4 to 99/1, from the viewpoint of temperature dependence of the elution behavior of the bioactive substance (E).

As the temperature-responsive crosslinked resin particles (A), alkyl (meth) acrylamide (a1) and / or vinylalkylamide (a2), a crosslinking agent (c) and (meth) acrylic acid alkyl ester (h) are essential constituents. Particles made of the resin (A2) used as a monomer are also preferable. When the (meth) acrylic acid alkyl ester (h) is contained in the essential constituent monomer, the resin has a lower LCST than when the (meth) acrylic acid alkyl ester (h) is not contained, and the resin (A2) has a lower LCST. A resin having an LCST of 15 to 25 ° C. is preferable. When the LCST of the resin (A2) is in this range, water is discharged from the hydrogel in the region below 25 ° C., and the elution of the bioactive substance (E) in the region exceeding the LCST can be suppressed.

Examples of the (meth) acrylate alkyl ester (h) include (meth) acrylate alkyl esters having 1 to 12 carbon atoms in the alkyl group, and preferred ones are methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, and the like. Examples thereof include propyl acrylate, propyl methacrylate, butyl methacrylate, butyl acrylate, lauryl acrylate and 2-ethylhexyl methacrylate, more preferably propyl acrylate, propyl methacrylate, butyl methacrylate and butyl acrylate, and more preferably butyl acrylate and butyl methacrylate. Yes, particularly preferably butyl methacrylate.

The total number of moles of alkyl (meth) acrylamide (a1) and vinylalkylamide (a2) constituting the resin (A2) is the total number of moles of alkyl (meth) acrylamide (a1) and vinylalkylamide (a2) (meth). ) The ratio [{(a1) + (a2)} / (h)] calculated based on the number of moles of the acrylic acid alkyl ester (h) is preferably 85/15 to 95/5, preferably 87/13. ~ 93/7 is more preferable. The total amount of N-alkyl (meth) acrylamide (a1) and N-vinylalkylamide (a2) used in the resin (A2) is 50 to 99 based on the total weight of the constituent monomers of the resin (A2). 9.9% by weight is preferable, and 98 to 99.8% by weight is more preferable.

In the resin (A2), the weight ratio of the total weight of N-alkyl (meth) acrylamide (a1) and N-vinylalkylamide (a2) in the constituent monomer to the weight of the cross-linking agent (c) [{(a1) + (A2)} / (c)] is preferably 95 / 5-99.9 / 0.1 from the viewpoint of temperature dependence of the elution behavior of the biologically active substance (E), 99.0 / 1. 0 to 99.8 / 0.2 is more preferable.

Examples of the temperature-responsive crosslinked resin particles (A) include alkyl (meth) acrylamide (a1) and / or N-vinylalkylamide (a2), a crosslinking agent (c), and (meth) acrylic acid (salt) (b). The number of moles of (meth) acrylic acid (salt) (b) with respect to the total number of moles of the constituent monomers of the resin containing the particles made of the resin (A3) as the essential constituent monomer (A3). It is also preferable that the ratio of is less than 5 mol%. In the present specification, "(meth) acrylic acid (salt)" refers to (meth) acrylic acid and / or a salt thereof. The resin (A3) contains (meth) acrylic acid (salt) (b) in an amount of less than 5 mol% (preferably 0.01 mol% or more and less than 5 mol%, more preferably 0) based on the total number of moles of the constituent monomers. When it is contained in a ratio of .01 to 3 mol%), it becomes a resin having a higher LCST than when it does not contain (meth) acrylic acid (salt) (b).

Examples of the (meth) acrylic acid (salt) (b) include alkali metal salts (sodium salt, potassium salt, lithium salt, etc.) of (meth) acrylic acid, ammonium salts, amine salts, and the like. Of these, an alkali metal salt of acrylic acid is preferable, and a sodium salt of acrylic acid is more preferable from the viewpoint of water absorption and the like.

The total number of moles of alkyl (meth) acrylamide (a1) and vinylalkylamide (a2) constituting the resin (A3) is the total number of moles of alkyl (meth) acrylamide (a1) and vinylalkylamide (a2) (meth). ) The ratio [{(a1) + (a2)} / (h)] calculated based on the number of moles of the acrylic acid alkyl ester (h) is preferably 85/15 to 95/5, preferably 87/13. ~ 93/7 is more preferable. The total amount of N-alkyl (meth) acrylamide (a1) and N-vinylalkylamide (a2) used in the resin (A3) is 50 to 99 based on the total weight of the constituent monomers of the resin (A3). 9.9% by weight is preferable, and 98 to 99.8% by weight is more preferable.

In the resin (A3), the weight ratio of the total weight of N-alkyl (meth) acrylamide (a1) and N-vinylalkylamide (a2) in the constituent monomers to the weight of the cross-linking agent (c) [{(a1) + (A2)} / (c)] is preferably 95 / 5-99.9 / 0.1 from the viewpoint of temperature dependence of the elution behavior of the biologically active substance (E), 96/4 to 98. 5 / 1.5 is even more preferred.

In the above resins (A1), (A2) and (A3), other monomers may be copolymerized as constituent monomers. The LCST of the resin can be adjusted by adjusting the type of other monomers to be copolymerized and the ratio of copolymerization, and by copolymerizing with the hydrophobic monomer, the LCST can be moved to the low temperature side and the hydrophilic monomer. The LCST can be moved to the high temperature side by copolymerizing.

Among other copolymerizable monomers, the preferred hydrophilic monomer is a monomer having a hydroxyl group, a polyoxyethylene chain, an amino group, or the like [hydroxyalkyl (meth) acrylate (hydroxyethyl methacrylate, hydroxy). Ethyl acrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, etc.), polyethylene glycol (meth) acrylate (methoxypolyethylene glycol (meth) acrylate, etc.), N-vinyl-2-pyrrolidone, (meth) acrylamide, etc.]. Preferred hydrophobic monomers include alkyl (meth) acrylamide having an alkyl group having more than 12 carbon atoms [N-alkyl (meth) acrylamide derivative such as Nn-dodecylacrylamide], N- (ω-). Glycydoxyalkyl) (meth) acrylamide [N, N-diglycidylacrylamide, N- (4-glycidoxybutyl) acrylamide, N- (5-glycidoxypentyl) acrylamide, N- (6-glycidoxy) Hexyl) acrylamide, N, N-diglycidylmethacrylamide, N- (4-glycidoxypentyl) methacrylicamide and N- (5-glycidoxyhexyl) methacrylicamide], (meth) acrylonitrile, vinyl carboxylate ester ( (Vinyl acetate, etc.), vinyl halide (vinyl chloride, etc.), mono or diolefin (ethylene, propylene, butene, butadiene, isoprene, etc.), aromatic vinyl (styrene, α-methylstyrene, etc.), and the like.

When the other monomers are further copolymerized in the resins (A1), (A2) and (A3), the proportion of the other monomers is the temperature used for the coated agricultural, forestry and horticultural granular chemicals of the present invention. It is adjusted according to the LCST of the responsive crosslinked resin particles (A).

The resins (A1), (A2) and (A3) are known methods such as a solution polymerization method, an emulsion polymerization method, a suspension polymerization method and a spray polymerization method (Japanese Patent Laid-Open No. 2004-83319, JP-A-2002-121230). It can be polymerized by the method described in Japanese Patent Application Laid-Open No. 8-100010 and the like), and a preferable polymerization method is a solution polymerization method using a radical polymerization initiator (more preferably, an aqueous solution polymerization). A known initiator can be used as the radical polymerization initiator, and the radical polymerization conditions (amount of radical polymerization initiator, monomer concentration, polymerization temperature, etc.) are the resins constituting the temperature-responsive crosslinked resin particles (A). The polymerization can be carried out by selecting from known conditions according to the molecular weight and the like, and various additives, chain transfer agents (for example, thiol compounds, etc.), surfactants and the like may be added as necessary. ..

The particles of the resins (A1), (A2) and (A3) are a mixture obtained by a method of pulverizing a polymer obtained by removing a solvent after solution polymerization and a suspension polymerization method, a spray polymerization method or the like. It can be obtained by a method of removing a solvent from the material to obtain particles or the like. Further, the particles obtained by these methods may be further classified by a known method such as sieving and used as the temperature-responsive crosslinked resin particles (A).

The shape of the temperature-responsive crosslinked resin particles (A) is not particularly limited, and even shapes such as spheres (including true spheres) and ellipsoids (obtained by suspension polymerization method, spray polymerization method, etc.) are not acceptable. It may be in a fixed form (obtained by a method of crushing a polymer). The particle size of the temperature-responsive crosslinked resin particles (A) can be adjusted according to the particle size of the particles (P0) containing the bioactive substance (E) provided with the coating layer, but the temperature-responsive resin particles (A) ), The volume average particle size (D ₅₀ ) is preferably 1 to 200 μm, more preferably 1 to 150 μm, and even more preferably 40 to 80 μm. When the particle size of the temperature-responsive crosslinked resin particles (A) is in the above range, a uniform coating layer is easily formed on the surface of the particles (P0), which is preferable. The volume average particle diameter of the temperature-responsive crosslinked resin particles (A) is measured by a dry particle size distribution measuring device (LS 13 320, etc. manufactured by Beckman Coulter) according to JIS Z 8825.

The coating resin (C) can be used without limitation as long as a coating layer can be formed on the surface of the particles (P0) containing the biologically active substance (E). Among them, from the viewpoint of controlling the elution of the bioactive substance (E), a polyurethane resin, a polyolefin resin, an alkyd resin and two or more kinds thereof are preferably used in combination, a polyurethane resin and a polyethylene resin are more preferable, and a polyurethane resin is particularly preferable.

As the polyurethane resin as the coating resin (C), a polyurethane resin obtained by curing a polyol component, a polyisocyanate and an amine compound is preferable.

Examples of the polyol component used in the polyurethane resin include castor oil, castor oil derivatives, ethylene oxide thereof, and adducts of alkylene oxide such as propylene oxide. Examples of the castor oil derivative include a partial hydrolyzate of castor oil, transesterified castor oil with diols (for example, ethylene glycol and propylene glycol), and a polyol such as glycerin and trimethylolpropane. The transesterifier of the above can be mentioned. Of these, a derivative (transesterified product) in which castor oil is transesterified with ethylene glycol or propylene glycol is preferable.

The polyisocyanate is not particularly limited, but an aromatic polyisocyanate is preferable, and tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), naphthalene diisocyanate, polyphenyl polymethylene polyisocyanate, phenylenedi isocyanate, xylylene diisocyanate, and tetramethyl Examples thereof include xylene diisocyanate and modified products thereof (for example, urea modified product, dimer, trimeric body, carbodiimide body, alohanate modified product, bullet modified product, etc.). Two or more of these can be used together, and as the polyisocyanate, it may be commercially available as "crude polyisocyanate" and may be a publicly used one for industrial use. Of the above, MDI, crude MDI, carbodiimidinated MDI (also referred to as liquid MDI), TDI and crude TDI are preferable.

Further, the polyisocyanate is preferably used as an isocyanate group-terminated prepolymer by reacting with the above-mentioned polyol component. As the polyol component used to obtain the isocyanate group-terminated prepolymer, the above-mentioned castor oil and castor oil derivative are preferable.
The isocyanate group-terminated prepolymer is obtained by reacting a polyisocyanate with a polyol component by a known method, and the equivalent ratio of NCO group / active hydrogen group between the polyisocyanate and the polyol is 1.1 to 50.0 (preferably). Is 1.2 to 25.0), and the reaction is preferably carried out at a reaction temperature of 30 to 130 ° C. (preferably 40 to 90 ° C.) for 1 to 5 hours.

Examples of the amine compound include alkylamines (trimethylamine, triethylamine, dimethylethylamine, dimethylisopropylamine, etc.) and amine-based polyols (di- or tri-ethanolamine and low-molecular-weight amines such as N-methyl-N, N'-diethanolamine). Polypoly; alkylenediamine such as ethylenediamine, 1,3-propanediamine, 1,6-hexanediamine, and alkylene oxide (hereinafter abbreviated as AO) such as propylene oxide (hereinafter abbreviated as PO) or ethylene oxide (hereinafter abbreviated as EO). Amine-based polyols to which (abbreviated) is added) can be mentioned.
As the amine-based polyol in which AO is added to alkylenediamine, oxypropylenediamine and oxyethylenediamine are preferable, and N, N, N', N'-tetrax [2-hydroxypropyl] ethylenediamine, N, N, N'. , N'-tetrakis [2-hydroxyethyl] ethylenediamine, N, N, N', N'-tetrakis [2-hydroxypropyl] -1,3-propanediamine, N, N, N', N'-tetrakis [ 2-Hydroxyethyl] -1,6-hexanediamine and the like can be mentioned, and from the viewpoint of reactivity and physical properties, N, N, N', N'-tetrax [2-hydroxypropyl] ethylenediamine, and N, N, N', N'-tetrax [2-hydroxyethyl] ethylenediamine are more preferred. As the amine compound, an amine-based polyol is preferably used. When an amine-based polyol is used, good compatibility between the obtained polyurethane resin and the temperature-responsive resin particles (A) can be obtained, and a uniform film can be easily formed. The amine-based polyol promotes the reaction and also acts as a cross-linking agent and a chain extender, so that good curability and tough film physical characteristics can be obtained.

Examples of the polyolefin resin as the coating resin (C) include polyethylene, polypropylene, ethylene / propylene copolymer, polybutene, butene / ethylene copolymer, butene / propylene copolymer and the like. Of these, polyethylene and polypropylene are preferable, and polyethylene is even more preferable.

As the alkyd resin as the coating resin (C), a known alkyd resin described in JP-A-2001-163691 or the like can be used.

The coating layer contained in the coated granular agent for agriculture, forestry and gardening of the present invention contains the temperature-responsive crosslinked resin particles (A) and the coating resin (C), and contains particles (P0) containing a bioactive substance (E). ), The temperature-responsive crosslinked resin particles (A) and the coating resin (C) may be attached to at least a part of the surface. Above all, it is preferable that the coating layer has a structure in which the temperature-responsive crosslinked resin particles (A) are dispersed in the resin (C). Further, from the viewpoint of controlling the elution of the biologically active substance (E), it is preferable to have a coating layer on the entire surface of the particles (P0).

The content of the temperature-responsive crosslinked resin particles (A) contained in the coating layer is the temperature-responsive crosslinked resin particles (A) and the coating resin (C) from the viewpoint of elution of the bioactive substance (E) and the like. Based on the total weight, 20 to 95% by weight is preferable, 25 to 75% by weight is more preferable, and 30 to 55% by weight is more preferable.

The content of the coating resin (C) contained in the coating layer is based on the total weight of the temperature-responsive resin particles (A) and the coating resin (C) from the viewpoint of elution of the bioactive substance (E) and the like. It is preferably 5 to 80% by weight, more preferably 45 to 80% by weight.

The thickness of the coating layer is not particularly limited, but is preferably 10 to 300 μm, more preferably 100 to 250 μm, from the viewpoint of elution of the biologically active substance (E) and the like. As for the thickness of the coating layer, the particles are observed with a digital microscope (manufactured by KEYENCE, VHX-200) in accordance with JIS 8827-1, which is a cross section obtained by cutting a coated granular chemical for agriculture, forestry and horticulture so as to pass through the center of the particles. Then, it is measured by image processing.

The method for forming a coating layer on the particle surface of the particles (P0) containing the bioactive substance (E) is not particularly limited, but the temperature-responsive crosslinked resin particles (A) are formed on the particles (P0) in a flowing state. ) And the above-mentioned coating resin (C) can be added and mixed by a known method. The particles (P0) can be brought into a fluid state by using a known fluidizer, and a method of flowing a gas through the powder layer, a powder mixer (container rotary mixer, ribbon mixer, etc.). It can be performed by a method using a Henschel mixer or the like, a method using a vibrating conveyor, or the like. The mixing of the particles (P0) in a fluid state, the temperature-responsive crosslinked resin particles (A), and the coating resin (C) is carried out in the fluidizing device with the particles (P0) and the temperature-responsive crosslinked resin. This can be done by coexisting the particles (A) and the coating resin (C) and fluidizing them. Among them, a method of adding a solution of the coating resin (C) dissolved in a solvent to the particles (P0) in the fluidized state, and further adding and mixing the temperature-responsive crosslinked resin particles (A), and a fluidized state. It is preferable to add a precursor of the coating resin (C) in a liquid state to the particles (P0) in the above, further add the temperature-responsive crosslinked resin particles (A), and mix the precursors while reacting them. It can be mentioned as a method.

In the above method of forming a coating layer on the particle surface of the particles (P0), the weight ratio of the particles (P0), the temperature-responsive crosslinked resin particles (A), and the coating resin (C) is the temperature of the particles (P0). The ratio of the responsive crosslinked resin particles (A) and the coating resin (C) {[particles (P0)] / {[(resin particles (A) + coating resin (C))} is 16/1 to 1/1. It is preferable to have.

Whether or not a coating layer is formed on the particle surface of the particle (P0) is determined by visually changing the color of the particle surface, changing the feel when the particle surface is touched with a finger, and the particle size measured using a microscope. It can be confirmed by the change of.

The coating layer contained in the coated granular agent for agriculture, forestry and horticulture of the present invention may contain other additive components other than the temperature-responsive crosslinked resin particles (A) having an LCST of 10 to 40 ° C. and the coating resin (C). Other additive components include known components that can be added to coated granular fertilizers, such as inorganic particles (talc, kaolin, clay and silicate powder, etc.), organic fine particles, no LCST, or LCST below 10 ° C. Examples thereof include water-absorbent resin particles exceeding 40 ° C., radical stabilizers, hydrophobic compounds (liquid paraffin and the like), surfactants and the like.
The amount of these other additive components added can be adjusted according to the purpose of addition, but when sodium polyacrylate crosslinked (co) polymer particles are used as the water-absorbent resin particles having no LCST, the amount thereof is adjusted. It is preferable that the amount added is small, and it is preferable not to use it from the viewpoint of exerting the effect of the drug such as plant growth for a long period of time.

The crops to which the coated agricultural, forestry and horticultural granular chemicals of the present invention can be applied are not limited, and food crops (rice, wheat, corn, potatoes, beans, etc.), forage crops, industrial crops and horticultural crops [fruit trees, vegetables (fruit trees, vegetables (fruit trees, vegetables)) It can be used for leafy vegetables, fruit vegetables, root vegetables, etc.) and flowers (1 year old plants, 2 year old plants, root vegetables, etc.)] and the like. Among them, it is suitably used for cultivating crops that are easily affected by components in soil, have a sensitive growth reaction to temperature conditions, and require fertilizer or the like for a long period of time. Further, the coated granular chemical for agriculture, forestry and horticulture of the present invention is used by spraying on the soil in which crops are cultivated, and even if it is sprayed only with the coated granular chemical for agriculture, forestry and horticulture, it is mixed with water and sprayed. You may use it.

In addition, the coated granular chemicals for agriculture, forestry and horticulture of the present invention are less likely to destroy the coating layer that controls the elution of biologically active substances contained in the chemicals due to rainfall, watering, etc. Not only can it be allowed to grow, but also the excessive elution of the bioactive substance (E) when the environmental temperature rises can be controlled, which is preferable in cropping in which the temperature rises during the cultivation period, such as when cultivating across seasons. Applicable.

Hereinafter, the present invention will be further described with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Hereinafter, unless otherwise specified,% indicates a weight% and a part indicates a weight part. The characteristic values of the temperature-responsive crosslinked resin particles (A) and the coated granular chemicals (F) for agriculture, forestry and horticulture were measured by the following methods.

<Volume average particle diameter of particles (P0) containing temperature-responsive crosslinked resin particles (A) and bioactive substance (E)>
The volume average particle diameter of the temperature-responsive crosslinked resin particles (A) was measured according to JIS Z 8825. A dry particle size distribution measuring device (LS 13320 manufactured by Beckman Coulter) was used for the measurement. The average number of particles of urea and oncol granules 5 used as the bioactive substance (E) was determined by observing the particles with a digital microscope (VHX-200, manufactured by KEYENCE) according to JIS 8827-1. It was measured by image processing.

<Lower critical solution temperature (LCST) of temperature-responsive crosslinked resin particles (A)>
A 1.0% by weight aqueous dispersion of the temperature-responsive crosslinked resin particles (A) was prepared, and the aqueous dispersion was heated every 1 ° C. in the range of 5 to 60 ° C., and the aqueous solution was prepared while maintaining the temperature. The light transmittance (wavelength 670 nm) of the aqueous dispersion at 1 ° C. was measured using a UV-vis spectrophotometer (UV-2550, manufactured by Shimadzu Corporation). The temperature when the light transmittance became 50% was defined as LCST.

<Number average particle size of coated granular chemicals (F) for agriculture, forestry and horticulture>
The number average particle size of the coated agricultural, forestry and horticultural granular chemicals (F) was measured by observing the particles with a digital microscope (manufactured by KEYENCE, VHX-200) and performing image processing according to JIS 8827-1. ..

<Film thickness of coating layer>
The film thickness of the coating layer is cut so as to pass through the center of gravity of the coated agricultural, forestry and horticultural granular chemicals (F), fixed to the sample table so that the cut surface can be observed, and according to JIS 8827-1, a digital microscope ( The particles were observed with a VHX-200) manufactured by KEYENCE, and measured by image processing. When the coating layers were scattered on a part of the drug surface, the average value of the film thickness of the coating layers observable from the cross section was used.

<Manufacturing example 1>
To the reaction vessel, 10 g of N-isopropylacrylamide, 0.025 g of N, N-methylenebisacrylamide, and 85 g of ion-exchanged water were added, and nitrogen substitution was carried out at 70 ° C. for 30 minutes while stirring at 200 rpm. Subsequently, 0.1 g of 2,2'-azobis (2-methylpropionamidine) dihydrochloride (V-50) was dissolved in 5 g of ion-exchanged water, and this aqueous solution was added dropwise into the system to initiate polymerization. The polymerization was carried out at 70 ° C. for 1 hour. After completion of the reaction, the resin dispersion was centrifuged (15000 rpm) to separate the resin from the supernatant, and the precipitated resin was redispersed in water. After repeating this operation three times, the obtained resin was dried under reduced pressure at 80 ° C. The obtained dried product was freeze-milled, classified using a standard sieve having a mesh size of 75 μm and a standard sieve having a mesh size of 45 μm, and the particles remaining on the standard sieve having a mesh size of 45 μm were separated into N-isopropylacrylamide crosslinked resin particles (A-). It was set as 1). The volume average particle diameter of the obtained particles (A-1) was 60 μm. The lower limit critical solution temperature (LCST) of the N-isopropylacrylamide crosslinked resin particles (A-1) was 32 ° C.

The volume average particle diameter of the temperature-responsive crosslinked resin particles (A) was measured according to JIS Z 8825. A dry particle size distribution measuring device (LS 13320 manufactured by Beckman Coulter) was used for the measurement.
The average number of particles of urea and oncol granules 5 used as the bioactive substance (E) was determined by observing the particles with a digital microscope (VHX-200, manufactured by KEYENCE) according to JIS 8827-1. It was measured by image processing.

<Manufacturing example 2>
N-vinylnormalpropylamide crosslinked resin particles (A-2) were prepared by performing the same operation as in Production Example 1 except that N-vinylnormalpropylamide was used instead of N-isopropylacrylamide in Production Example 1. .. The volume average particle diameter of the obtained N-vinylnormal propylamide crosslinked resin particles (A-2) was 60 μm. The LCST of the N-vinylnormal propylamide crosslinked resin particles (A-2) was 32 ° C.

<Manufacturing example 3>
To the reaction vessel, add 5 parts of N-isopropylacrylamide, 0.6 part of butyl methacrylate, 0.06 part of N, N-methylenebisacrylamide, and 30 parts of 1,4-dioxane, and stir at 200 rpm at 25 ° C. Nitrogen substitution was performed for 5 minutes. Subsequently, 0.1 part of azobisisobutyronitrile (AIBN) was added to the above reaction vessel to initiate polymerization, and the polymerization was carried out at 70 ° C. for 4 hours. After completion of the reaction, the mixture was reprecipitated with a mixed solution of methanol / water = 1/1 and dried under reduced pressure to obtain N-isopropylacrylamide / butyl methacrylate crosslinked copolymer resin particles (A-3). The volume average particle size of the obtained particles (measured in the same manner as in Production Example 1) was 60 μm. The LCST of the N-isopropylacrylamide-butylmethacrylate crosslinked copolymer resin particles (A-3) was 20 ° C.

<Manufacturing example 4>
To the reaction vessel, add 5 parts of N-isopropylacrylamide, 0.6 part of butyl methacrylate, 0.1 part of acrylic acid, 0.06 part of N, N-methylenebisacrylamide, and 30 parts of 1,4-dioxane, and add 200 rpm. Nitrogen substitution was carried out at 25 ° C. for 5 minutes while stirring with. Subsequently, 0.1 part of azobisisobutyronitrile (AIBN) was added to the above reaction vessel to initiate polymerization, and the polymerization was carried out at 70 ° C. for 4 hours. After completion of the reaction, the mixture was reprecipitated with a mixed solution of methanol / water = 1/1 and dried under reduced pressure to obtain N-isopropylacrylamide / butyl methacrylate / acrylic acid crosslinked copolymer resin particles (A-4). The volume average particle size of the obtained particles (measured in the same manner as in Production Example 1) was 60 μm. The LCST of the N-isopropylacrylamide-butylmethacrylate-acrylic acid crosslinked copolymer resin particles (A-4) was 20 ° C.

<Manufacturing example 5>
In Production Example 1, N-ethylacrylamide crosslinked resin particles (A'-1) were prepared by performing the same operation as in Production Example 1 except that N-ethylacrylamide was used instead of N-isopropylacrylamide. The volume average particle size (measured in the same manner as in Production Example 1) of the obtained N-ethylacrylamide crosslinked resin particles (A'-1) was 60 μm. The LCST of the poly (N-ethylacrylamide) crosslinked resin particles (A'-1) was 73 ° C.

<Manufacturing example 6>
32 parts of castor oil and 68 parts of diphenylmethane diisocyanate were charged in a reaction vessel and reacted at 70 ° C. for 3 hours to obtain an isocyanate group-terminated prepolymer (C-1-2) having an NCO% of 19%.

<Manufacturing example 7>
The same procedure as in Production Example 1 was carried out except that the particles were classified using a standard sieve having a mesh size of 150 μm and a standard sieve having a mesh size of 90 μm. ). The volume average particle diameter of the obtained particles (A-5) was 120 μm. The lower critical solution temperature (LCST) of the N-isopropylacrylamide crosslinked polymer (A-5) was 32 ° C.

<Example 1: Coated agricultural, forestry and horticultural granular chemicals (F-1)>
46.9 parts of N-isopropylacrylamide crosslinked resin particles produced in Production Example 1 (A-1, 20.4 parts of castor oil, 4.8 parts of amine compound (C-1-1) (New Pole NP-300) , Sanyo Kasei Kogyo Co., Ltd., and 0.6 parts of ethyl methyl ketone were mixed, and then 27.3 parts of the isocyanate group-terminated prepolymer (C-1-2) produced in Production Example 5 was added. , Stirring, thereby mixing with castor oil, amine compound (C-1-1), isocyanate group-terminated prepolymer (C-1-2), and N-isopropylacrylamide co-resin particles (A-1). A solution was obtained. Using a flow coating device using a jet layer, 233.3 parts of Oncol granules 5 (manufactured by OAT Agrio Co., Ltd.) (number average particle size 2 mm) suspended in the device were described. 93.3 parts of the mixed solution of (F-1) was added by spray spraying, coated, and cured at room temperature to prepare a coated granular chemical (F-1) for agriculture, forestry and gardening.
The film thickness of the coating layer of the coated granular chemical (F-1) for agriculture, forestry and horticulture was 180 μm. The average particle size of the coated granular chemicals (F-1) for agriculture, forestry and horticulture was 2360 μm.
The reaction between castor oil, the amine compound (C-1-1) and the isocyanate group-terminated prepolymer (C-1-2) forms a polyurethane resin (C-1) as a coating resin.

The average particle size of the coated granular chemicals (F-1) for agriculture, forestry and horticulture is determined by observing the particles with a digital microscope (VHX-200, manufactured by KEYENCE) and performing image processing in accordance with JIS 8827-1. It was measured.
The film thickness of the coating layer is cut so that it passes through the center of the particles of the coated agricultural, forestry and horticultural chemicals, fixed on the sample table so that the cut surface can be observed, and according to JIS 8827-1, a digital microscope (KEYENCE). The particles were observed with a VHX-200) manufactured by the same company and measured by image processing.
The number average particle size and the film thickness of the coating layer of the coated agricultural, forestry and horticultural granular chemicals (F) in Examples 2 to 23 and Comparative Examples 1 to 8 below were also measured by the same method.

<Example 2: Covered agricultural, forestry and horticultural granular chemicals (F-2)>
In Example 1, the weight of the N-isopropylacrylamide crosslinked resin particles (A-1) was 26.1 parts, the amount of castor oil used was 28.4 parts, the amount of amine compound used was 6.7 parts, and methyl ethyl ketone. Was changed to 0.8 parts, the amount of isocyanate group-terminated prepolymer (C-1-2) was changed to 38.0 parts, and the amount of oncol granules used was changed to 424.0 parts. The same operation as in Example 1 was carried out to prepare a coated type granular chemical for agriculture, forestry and gardening (F-2). The film thickness of the coating layer of the coated granular chemical (F-2) for agriculture, forestry and horticulture was 160 μm. The average particle size of the coated granular chemicals (F-2) for agriculture, forestry and horticulture was 2320 μm.

<Example 3: Covered agricultural, forestry and horticultural granular chemicals (F-3)>
In Example 1, the amount of N-isopropylacrylamide crosslinked resin particles (A-1) used was 72.6 parts, the amount of castor oil used was 10.5 parts, and the amount of amine compound used was 2.5 parts. Except that the amount of methyl ethyl ketone used was changed to 0.3 parts, the amount of isocyanate group-terminated prepolymer (C-1-2) used was changed to 14.1 parts, and the amount of oncol granules used was changed to 120.7 parts. The same operation as in Example 1 was carried out to prepare a coated type granular chemical agent (F-3) for agriculture, forestry and gardening. The film thickness of the coating layer of the coated granular chemical (F-3) for agriculture, forestry and horticulture was 200 μm. The average particle size of the coated granular chemicals (F-3) for agriculture, forestry and horticulture was 2400 μm.

<Example 4: Covered agricultural, forestry and horticultural granular chemicals (F-4)>
Except that in Example 1, the N-isopropylacrylamide crosslinked resin particles (A-1) were changed to N-isopropylacrylamide crosslinked resin particles (A-5) having a volume average particle diameter of 120 μm obtained in Production Example 7. The same operation as in Example 1 was carried out to prepare a coated type granular chemical for agriculture, forestry and gardening (F-4). The film thickness of the coated granular chemical (F-4) for agriculture, forestry and horticulture was 180 μm. The average particle size of the coated granular chemicals (F-4) for agriculture, forestry and horticulture was 2360 μm.

<Example 5: Coated agricultural, forestry and horticultural granular chemicals (F-5)>
Example 1 and Example 1 except that the N-vinylnormal propylamide crosslinked resin particles (A-2) produced in Production Example 2 were used instead of the N-isopropylacrylamide crosslinked resin particles (A-1). The same operation was carried out to prepare a coated type granular chemical for agriculture, forestry and horticulture (F-5). The film thickness of the coating layer of the coated granular chemical (F-5) for agriculture, forestry and horticulture was 180 μm. The average particle size of the coated granular chemicals (F-5) for agriculture, forestry and horticulture was 2360 μm.

<Example 6: Coated agricultural, forestry and horticultural granular chemicals (F-6)>
In Example 1, the same operation as in Example 1 was performed except that 1590 parts of commercially available urea (number average particle size 3 mm) was used instead of Oncol granule 5, and a coated type agricultural, forestry and horticultural granular drug (F-) was used. 6) was prepared. The film thickness of the coating layer of the coated granular chemical (F-6) for agriculture, forestry and horticulture was 180 μm. The average particle size of the coated granular chemicals (F-6) for agriculture, forestry and horticulture was 3360 μm.

<Example 7: Coated agricultural, forestry and horticultural granular chemicals (F-7)>
In Example 2, the same operation as in Example 2 was performed except that 1590 parts of commercially available urea (number average particle size 3 mm) was used instead of Oncol granule 5, and a coated type agricultural, forestry and horticultural granular drug (F-) was used. 7) was prepared. The film thickness of the coating layer of the coated granular chemical (F-7) for agriculture, forestry and horticulture was 160 μm. The average particle size of the coated granular chemicals (F-7) for agriculture, forestry and horticulture was 3320 μm.

<Example 8: Coated agricultural, forestry and horticultural granular chemicals (F-8)>
In Example 3, the same operation as in Example 3 was performed except that 1590 parts of commercially available urea (number average particle size 3 mm) was used instead of Oncol granule 5, and the coated type agricultural, forestry and horticultural granular drug (F-) was used. 8) was prepared. The film thickness of the coating layer of the coated type agricultural, forestry and horticultural granular chemicals (F-8) was 200 μm. The average particle size of the coated granular chemicals (F-8) for agriculture, forestry and horticulture was 3400 μm.

<Example 9: Coated agricultural, forestry and horticultural granular chemicals (F-9)>
In Example 4, the same operation as in Example 4 was performed except that 1590 parts of commercially available urea (number average particle size 3 mm) was used instead of Oncol granule 5, and a coated type agricultural, forestry and horticultural granular drug (F-) was used. 9) was prepared. The film thickness of the coating layer of the coated granular chemical (F-9) for agriculture, forestry and horticulture was 180 μm. The average particle size of the coated granular chemicals (F-9) for agriculture, forestry and horticulture was 3360 μm.

<Example 10: Coated agricultural, forestry and horticultural granular chemicals (F-10)>
In Example 5, the same operation as in Example 5 was performed except that 1590 parts of commercially available urea (number average particle size 3 mm) was used instead of Oncol granule 5, and a coated type agricultural, forestry and horticultural granular drug (F-) was used. 10) was prepared. The film thickness of the coated agricultural, forestry and horticultural granular chemicals (F-10) was 180 μm. The average particle size of the coated granular chemicals (F-10) for agriculture, forestry and horticulture was 3360 μm.

<Example 11: Coated agricultural, forestry and horticultural granular chemicals (F-11)>
In Example 1, 46.9 parts of N-isopropylacrylamide crosslinked resin particles (A-1) were used, and 23.5 parts of N-isopropylacrylamide crosslinked resin particles (A-1) and 23.5 parts were used. The same operation as in Example 1 was carried out except that it was changed to be used in combination with the N-vinylnormal propylamide crosslinked resin particles (A-2) of No. 1 in the coated type agricultural, forestry and gardening granular chemicals (F-11). ) Was prepared. The film thickness of the coating layer of the coating type granular chemicals for agriculture, forestry and horticulture (F-11) was 180 μm. The average particle size of the coated granular chemicals (F-11) for agriculture, forestry and horticulture was 2360 μm.

<Example 12: Coated agricultural, forestry and horticultural granular chemicals (F-12)>
The N-isopropylacrylamide crosslinked resin particles (A-1) produced in Production Example 1 of 46.9 parts, 1.2 parts of polyethylene and 51.9 parts of decan were stirred and mixed, and polyethylene was dissolved in the decan. A mixed solution was prepared. Using a fluidized coating device with a jet layer, spray 93.3 parts of this mixed solution on Oncol granules 5 (manufactured by OAT Agrio Co., Ltd.) (number average particle size 2 mm) 233.3 floating in the device. A coated type agricultural, forestry and horticultural granular chemical (F-12) was prepared by adding by spraying, coating, and curing at room temperature. The film thickness of the coating layer of the coated granular chemical (F-1) for agriculture, forestry and horticulture was 180 μm. The coated agricultural, forestry and horticultural granular chemical (F-12) is a coated agricultural, forestry and horticultural granular chemical having a coating layer containing the particles of (A-1) and the polyethylene resin (C-2) which is a coating resin. The number average particle size of (F-12) was 2360 μm.

<Example 13: Coated agricultural, forestry and horticultural granular chemicals (F-13)>
In Example 1, the N-isopropylacrylamide / butyl methacrylate crosslinked co-resin particles (A-3) produced in Production Example 3 were used instead of the N-isopropylacrylamide crosslinked resin particles (A-1). The same operation as in Example 1 was carried out to prepare a coated type granular chemical for agriculture, forestry and horticulture (F-13). The film thickness of the coating layer of the coating type granular chemicals for agriculture, forestry and horticulture (F-13) was 180 μm. The average particle size of the coated granular chemicals (F-13) for agriculture, forestry and horticulture was 2360 μm.

<Example 14: Coated agricultural, forestry and horticultural granular chemicals (F-14)>
Example 2 except that the N-isopropylacrylamide crosslinked resin particles (A-1) were changed to the N-isopropylacrylamide / butyl methacrylate crosslinked co-resin particles (A-3) produced in Production Example 3. The same operation as in No. 2 was carried out to prepare a coated type granular chemical for agriculture, forestry and horticulture (F-14). The film thickness of the coated agricultural, forestry and horticultural granular chemicals (F-14) was 160 μm. The average particle size of the coated granular chemicals (F-14) for agriculture, forestry and horticulture was 2320 μm.

<Example 15: Coated agricultural, forestry and horticultural granular chemicals (F-15)>
Example 3 except that the N-isopropylacrylamide crosslinked resin particles (A-1) were changed to the N-isopropylacrylamide / butyl methacrylate crosslinked co-resin particles (A-3) produced in Production Example 3. The same operation as in No. 3 was carried out to prepare a coated type granular chemical for agriculture, forestry and horticulture (F-15). The film thickness of the coated agricultural, forestry and horticultural granular chemicals (F-15) was 200 μm. The average particle size of the coated granular chemicals (F-15) for agriculture, forestry and horticulture was 2400 μm.

<Example 16: Coated agricultural, forestry and horticultural granular chemicals (F-16)>
In Example 1, the N-isopropylacrylamide crosslinked resin particles (A-1) were changed to the N-isopropylacrylamide / butyl methacrylate / acrylic acid crosslinked copolymer resin particles (A-4) produced in Production Example 4. Except for the above, the same operation as in Example 1 was carried out to prepare a coated type granular chemical for agriculture, forestry and gardening (F-16). The film thickness of the coated type agricultural, forestry and horticultural granular chemicals (F-16) was 180 μm, and the number average particle size was 2360 μm.

<Example 17: Coated agricultural, forestry and horticultural granular chemicals (F-17)>
In Example 13, the same operation as in Example 13 was performed except that commercially available urea (number average particle size 3 mm) 1590 was used instead of Oncol granule 5, and a coated granular chemical for agriculture, forestry and horticulture (F-17) was used. ) Was prepared. The film thickness of the coating layer of the coated type agricultural, forestry and horticultural granular chemicals (F-17) was 180 μm, and the number average particle size was 3360 μm.

<Example 18: Coated agricultural, forestry and horticultural granular chemicals (F-18)>
In Example 14, the same operation as in Example 14 was performed except that 1590 parts of commercially available urea (number average particle size 3 mm) was used instead of the on-col granule 5, and the coated type agricultural, forestry and horticultural granular drug (F-) was used. 18) was prepared. The film thickness of the coating layer of the coated type agricultural, forestry and horticultural granular chemicals (F-18) was 160 μm, and the number average particle size was 3320 μm.

<Example 19: Coated agricultural, forestry and horticultural granular chemicals (F-19)>
In Example 15, the same operation as in Example 15 was performed except that 1590 parts of commercially available urea (number average particle size 3 mm) was used instead of the on-col granule 5, and the coated type agricultural, forestry and horticultural granular drug (F-) was used. 19) was prepared. The film thickness of the coating layer of the coated type agricultural, forestry and horticultural granular chemicals (F-19) was 200 μm, and the number average particle size was 3400 μm.

<Example 20: Coated agricultural, forestry and horticultural granular chemicals (F-20)>
In Example 16, the same operation as in Example 16 was performed except that 1590 parts of commercially available urea (number average particle size 3 mm) was used instead of the on-col granule 5, and the coated type agricultural, forestry and horticultural granular drug (F-) was used. 20) was prepared. The film thickness of the coating layer of the coated type agricultural, forestry and horticultural granular chemicals (F-20) was 180 μm, and the number average particle size was 3360 μm.

<Example 21: Coated agricultural, forestry and horticultural granular chemicals (F-21)>
46.9 parts of N-isopropylacrylamide / butyl methacrylate crosslinked copolymer resin particles (A-3) produced in Production Example 3 and 1.2 parts of polyethylene and 51.9 parts of decan are stirred and mixed. Polyethylene was dissolved in decan to prepare a mixed solution. Using a fluidized coating device with a jet layer, 93.3 parts of this mixed solution was applied to 233.3 parts of Oncol granules 5 (manufactured by OAT Agrio Co., Ltd.) (number average particle size 2 mm) suspended in the device. A coated type agricultural, forestry and horticultural granular chemical (F-21) was prepared by adding by spraying, coating, and curing at room temperature. The film thickness of the coating layer of the coated type agricultural, forestry and horticultural granular chemicals (F-21) was 180 μm, and the number average particle size was 2360 μm.

<Comparative Example 1: Comparative coated agricultural, forestry and horticultural granular chemicals (F'-1)>
In Example 1, instead of the poly (N-isopropylacrylamide) crosslinked polymer resin particles (A-1), the poly (N-ethylacrylamide) crosslinked polymer resin particles (A'-1) produced in Production Example 5 were used. The same operation as in Example 1 was carried out except that it was used, and a comparative coated type agricultural, forestry and horticultural granular drug (F'-1) was prepared. The film thickness of the coating layer of the comparative coated type agricultural, forestry and horticultural granular chemical (F'-1) was 180 μm, and the number average particle size was 2360 μm.

<Comparative Example 2: Comparative coated agricultural, forestry and horticultural granular chemicals (F'-2)>
In Comparative Example 1, the same operation as in Comparative Example 1 was performed except that 1590 parts of commercially available urea (number average particle diameter 3 mm) was used instead of Oncol granule 5, and a comparative coated type agricultural, forestry and horticultural granular drug (for comparison). F'-2) was prepared. The film thickness of the coating layer of the comparative coated type agricultural, forestry and horticultural granular chemicals (F'-2) was 180 μm, and the number average particle size was 3360 μm.

<Comparative Example 3: Comparative coated agricultural, forestry and horticultural granular chemicals (F'-3)>
In Example 1, instead of the poly (N-isopropylacrylamide) crosslinked resin particles (A-1), the crosslinked resin particles (A'-2) of sodium polyacrylate (trade name "Sunfresh ST-500MPSA", Sanyo The same operation as in Example 1 was carried out except that a volume average particle diameter of 35 μm (manufactured by Kasei Kogyo Co., Ltd.) was used to prepare a coated granular chemical for agriculture, forestry and gardening (F'-3) for comparison. The film thickness of the coating layer of the comparative coated type agricultural, forestry and horticultural granular chemicals (F'-3) was 180 μm, and the number average particle size was 2360 μm.

<Comparative Example 4: Comparative coated agricultural, forestry and horticultural granular chemicals (F'-4)>
In Comparative Example 3, the same operation as in Comparative Example 3 was performed except that 1590 parts of commercially available urea (number average particle diameter 3 mm) was used instead of Oncol granule 5, and a comparative coated type agricultural, forestry and horticultural granular drug (for comparison). F'-4) was prepared. The film thickness of the coating layer of the comparative coated type agricultural, forestry and horticultural granular chemicals (F'-4) was 180 μm, and the number average particle size was 3360 μm.

Compositions of Coated Agricultural and Forestry Granular Agents (F1 to 21) and Comparative Coated Agricultural and Forestry Granular Agents (F'1 to 4) obtained in Examples (1 to 21) and Comparative Examples (1 to 4) And characteristic values such as particle size are shown in Tables 1 to 3.

The coated agricultural, forestry and horticultural granular agents (F1 to 21) and the comparative coated agricultural, forestry and horticultural granular agents (F'1 to 4) obtained in Examples (1 to 21) and Comparative Examples (1 to 4) are used, respectively. The dissolution test was carried out by the following method, and the results are shown in Tables 1 to 3. For Examples 1 to 12 in which the LCST of the temperature-responsive resin particles (A) exceeds 25 ° C., the elution rate was not measured at 15 ° C., and the LCST of the temperature-responsive resin particles (A) was less than 25 ° C. For certain Examples 13 to 21, the elution rate was not measured at 35 ° C.

<Elution rate of biologically active substance (E) (dissolution rate after 30 days and number of days reaching 80%)>
The elution rate of the bioactive substance (E) from urea and oncol granules 5 was calculated by the following method.
10 g of coated agricultural, forestry and horticultural granular chemicals or comparative coated agricultural, forestry and horticultural granular chemicals were placed on the bottoms of three glass containers (volume 250 mL), respectively, and three waters adjusted to 15 ° C, 25 ° C or 35 ° C were added. 200 mL was poured into each of the glass containers so that the coated granular chemicals for agriculture, forestry and horticulture at the bottom were immersed. Immediately close the lid of the glass container and put it in a small environmental tester (SU-222, manufactured by ESPEC) set to a temperature (15 ° C, 25 ° C or 35 ° C) corresponding to the temperature of water, and underwater by the following method. The change in the concentration of the physiologically active substance (E) was measured.

<Elution rate when the bioactive substance (E) is urea>
For the aqueous solution in the glass container placed in the small environmental tester by the above method, 1 mL was sampled every 7 days, 80 μL of the measurement solution containing urease was added to 10 μL of the sampled solution, and QuantiChrom Urea Assay Kit of BioAssy Systems Co., Ltd. Using II, the absorbance at the absorption wavelength (557 nm) of urea was measured using PowerWave XS of BioTEK Instruments as a detection device, and urea was prepared using a calibration line prepared from an aqueous solution having a known urea concentration prepared at a predetermined concentration. The concentration of was calculated. The value of the urea elution rate obtained by sampling every 7 days [the weight of the eluted urea relative to the weight of the urea contained in 10 g of the coated type agricultural, forestry and horticultural granular drug before the test or the comparative coated type agricultural, forestry and horticultural granular drug]. By plotting and graphing the number of days from the start of the test, the number of days required for the urea elution rate to reach 80% at each temperature of 15 ° C, 25 ° C or 35 ° C was determined, and D15, D25 and D35, respectively. And said. Then, from the values of D15, D25 and D35, the high temperature temperature dependence index (D15 / D25) and the low temperature temperature dependence index (D25 / D35) were obtained.
The urea contained in the aqueous solution in the glass container placed in a small environmental tester for 30 days was measured in the same manner as described above, and the amount of urea contained in the coated agricultural, forestry and gardening granular chemicals before the test (before being put in water). The ratio of (g) to the amount of urea (g) dissolved in water in the glass container was calculated and used as the dissolution rate (%) after 30 days.

<Elution rate when the particles containing the physiologically active substance (E) are Oncol granules 5>
The absorbance at the absorption wavelength (280 nm) of the physiologically active substance (benflacarb: content concentration 5% by weight) contained in Oncol granules 5 was measured, and a calibration curve prepared from a solution of Orcon 5 in which the concentration of benfracarb was known. The number of days required for the elution rate of benflacable to reach 80% and the elution rate (%) after 30 days were measured in the same manner as in the case of urea except that the above-mentioned urea was used.

<Shape of coated granular chemicals for agriculture, forestry and horticulture after chemical dissolution test>
The temperature dependence index at low temperature is measured by the above method, and when the chemical elution rate reaches 80%, the coated granular chemical for agriculture, forestry and horticulture is pulled out of the water, and it is taken outdoors under the roof so as not to get wet with rain. It was left to dry for 3 days. The state of the coated granular chemicals for agriculture, forestry and horticulture after drying was visually observed, and the results are shown in Tables 1 to 3.
The state of the coated granular chemicals for agriculture, forestry and horticulture after drying was evaluated according to the following criteria.
◯: There is no destruction of the coating layer.
X: The coating layer is destroyed.

From Tables 1 to 3, the coated agricultural, forestry and horticultural granular chemicals (F-1 to 21) of the present invention are different from the comparative coated agricultural, forestry and horticultural granular agents, and the coating layer is destroyed even if they are dried again after being immersed in water. It doesn't happen. Since the coating layer that suppresses the release of the drug is not destroyed, the elution rate can be adjusted for a long period of time without being affected by the weather or the like. In addition, the number of days when the dissolution rate reaches 80% is longer than that of the comparative coated type granular chemical for agriculture, forestry and horticulture, and it can be used as the granular chemical for agriculture, forestry and horticulture for a long period of time. Further, as compared with Comparative Examples, the coated agricultural, forestry and horticultural granular chemicals of Examples 1 to 12 of the present application were carried out because the ratio of the temperature dependence index at high temperature to the dissolution rate after 30 days (EL35 / EL25) was closer to 1, respectively. The coated agricultural, forestry and horticultural granular chemicals obtained in Examples 13 to 21 have a temperature-dependent index at low temperature and a ratio of elution rate after 30 days (EL25 / EL15) closer to 1, respectively, and the temperature-responsive resin contained therein. It can be seen that it also has the effect that the change in elution behavior of the particles before and after LCST is small.

The coated granular chemical for agriculture, forestry and horticulture of the present invention can maintain the dosage form as the granular chemical for coated agriculture, forestry and horticulture for a long period of time without being affected by the weather, and when used as a fertilizer or pesticide. The active ingredient can be stably supplied to the plant, resulting in good growth and improved yield.

Claims (8)

A coated agricultural, forestry and horticultural granular drug having a coating layer that covers at least a part of the particle surface of the particles (P0) containing the bioactive substance (E).
A coated granular chemical for agriculture, forestry and horticulture, wherein the coating layer contains temperature-responsive crosslinked resin particles (A) and a coating resin (C) having a lower limit critical solution temperature of 10 to 40 ° C. with respect to water. The temperature-responsive resin particles (A) are essential constituents of alkyl (meth) acrylamide (a1) and / or N-vinylalkylamide (a2) having an alkyl group having 2 to 6 carbon atoms and a cross-linking agent (c). The coated granular agent for agriculture, forestry and gardening according to claim 1, which contains particles made of a resin (A1) as a weight. The temperature-responsive resin particles (A) are essential constituent monomers of alkyl (meth) acrylamide (a1) and / or vinylalkylamide (a2), cross-linking agent (c) and (meth) acrylic acid alkyl ester (h). The coated granular agent for agriculture, forestry and gardening according to claim 1 or 2, which contains particles made of the resin (A2). Ratio of the total number of moles of alkyl (meth) acrylamide (a1) and vinyl alkylamide (a2) to the number of moles of (meth) acrylic acid alkyl ester (h) [{(a1) + (a2)} / (h) ] Is 85/15 to 95/5. The coated granular agent for agriculture, forestry and horticulture according to claim 3. The temperature-responsive resin particles (A) are essential constituents of alkyl (meth) acrylamide (a1) and / or vinylalkylamide (a2), cross-linking agent (c) and (meth) acrylic acid (salt) (b). The ratio of the number of moles of (meth) acrylic acid (salt) (b) to the total number of moles of all the monomers containing the body resin (A3) and constituting the resin (A3) is 5 mol%. The coated granular agent for agriculture, forestry and gardening according to any one of claims 1 to 4, which is less than. The coated granular agent for agriculture, forestry and horticulture according to any one of claims 2 to 5, wherein N-alkyl (meth) acrylamide (a1) is N-isopropylacrylamide. The coated granular agent for agriculture, forestry and horticulture according to any one of claims 1 to 6, wherein the number average particle diameter of the particles (P0) containing the bioactive substance (E) is 0.3 to 15 mm. The coated granular agent for agriculture, forestry and horticulture according to any one of claims 1 to 7, wherein the coating resin (C) is one or more kinds of resins selected from the group consisting of polyurethane resin, polyethylene resin and alkyd resin.