Title of Invention	PROCESS FOR PRODUCING WATER-DISPERSIBLE PARTICULATE AGRICULTURAL-CHEMICAL COMPOSITION
Abstract	A process for efficiently producing a water-dispersible particulate agricultural-chemical composition having improved disintegrability/dispersibility in water, the composition having a particular size in the range of 50 - 1,000 µm. The process is characterized by comprising the following steps (a) to (e) : (a) a step of kneading an agricultural-chemical active ingredient, a surfactant, and water; (b) a step of extruding the resultant mixture through a screen having pores 600 - 2,000 µm in diameter to form granules; (c) a step of drying the granules; (d) a step of rotating two toothed rolls with irregularities on the surface arranged in parallel to each other, and leading the dried granules to pass between the toothed rolls thereby pulverizing the granules; and (e) a step of sieving the pulverized granules.

Title of Invention

PROCESS FOR PRODUCING WATER-DISPERSIBLE PARTICULATE AGRICULTURAL-CHEMICAL COMPOSITION

Abstract

A process for efficiently producing a water-dispersible particulate agricultural-chemical composition having improved disintegrability/dispersibility in water, the composition having a particular size in the range of 50 - 1,000 µm. The process is characterized by comprising the following steps (a) to (e) : (a) a step of kneading an agricultural-chemical active ingredient, a surfactant, and water; (b) a step of extruding the resultant mixture through a screen having pores 600 - 2,000 µm in diameter to form granules; (c) a step of drying the granules; (d) a step of rotating two toothed rolls with irregularities on the surface arranged in parallel to each other, and leading the dried granules to pass between the toothed rolls thereby pulverizing the granules; and (e) a step of sieving the pulverized granules.

Full Text	DESCRIPTION PROCESS FOR PRODUCING WATER-DISPERSIBLE PARTICULATE AGRICULTURAL-CHEMICAL COMPOSITION Technical Field [0001] The present invention relates to a process for producing a water-dispersible particulate agricultural-chemical composition for use in controlling pests and weeds for agricultural/horticultural crops. Background Art [0002] Heretofore, various types of agricultural-chemical formulations such as dusts, granules, wettable powders, water-dispersible particulates, liquids, aqueous suspensions, emulsifiable concentrates, and the like have been known. Of these agricultural-chemical formulations, water-dispersible particulates are easy for users to handle since they do not powder during use thereof and therefore users would be exposed little to the agricultural-chemical ingredient and since they are easy to meter. Accordingly, forms of recent agricultural-chemical formulations tend to be changed from wettable powders to water-dispersible particulates. [0003] In general water-dispersible particulates should easily disperse in water, and for this purpose they should be produced by a method in which granulation is not accompanied by application of pressure and the resulting granules are free from a consolidated structure. Such methods include a so-called fluidized-bed granulation method where a powdery mixture of an agricultural-chemical active ingredient, a surfactant and an extender or the like is fluidized in a layer into which hot air is pumped, and an aqueous solution containing a binder is sprayed thereon to make the powdery particles aggregate together thereby forming granules; and a so-called stirring granulation method where an aqueous solution containing a binder is sprayed on a powdery mixture of an agricultural-chemical active ingredient, a surfactant and an extender or the like kept stirred at high speed to make the powdery particles aggregate together thereby forming granules (Non-Patent Documents 1 and 2). [0004] In these methods, however, the granules produced have a broad particle size distribution and sieving results in a low production yield with respect to a necessary particle size. In addition, since the granulation is carried out as a batch process, the amount of the granules to be produced per unit time is small. Therefore, the methods are substantially unsuitable for industrial production of agricultural chemicals. [0005] On the other hand, as a granulation method that secures high producibility of agricultural-chemical formulations, there is a so-called extrusion granulation method where an agricultural-chemical active ingredient, a surfactant and an extender or the like are kneaded with water, and extruded through pores formed in a screen to give columnar granules (Non-Patent Document 1) . In this method, a high pressure is given to extrude the mixture through the pores and, as a result, the formed granules have a consolidated structure with poor water-dispersibility. In this connection, while the water-dispersibility could be improved by reducing the diameter of the pores to have smaller granules, the pressure to be imparted to the screen may increase with reduction in the diameter of the pores and cause increased fragility of the screen thereby precluding the granulation itself. [0006] Also, as a method for producing a granular agricultural-chemical composition having improved water-dispersibility and suspensibility of agricultural-chemical ingredient, there is a method in which a mixture containing an agricultural-chemical active ingredient and a surfactant is kneaded with water, and the kneaded mixture is pulverized to have a predetermined particle size and dried, or the kneaded mixture is dried and made to have a predetermined particle size (Patent Document 1) . In this method, although the resulting granules are not in a consolidated state and have good water-dispersibility, the step of pulverizing the kneaded mixture may cause problems. Specifically, in the case where the kneaded mixture before dried is pulverized, the mixture significantly adheres to the pulverizer because of water contained in the mixture On the other hand, the kneaded mixture which is dried before the pulverization is extremely brittle and the size distribution of the pulverized particles is large, therefore the production yield of the granular agricultural-chemical composition having the intended particle size is extremely low. [0007] Patent Document 1: JP-A 2001-288004 Non-Patent Document 1: Handbook of Granulation Technology, edited by the Association of Power Process Industry and Engineering, Japan Non-Patent Document 2: Granulation Manual, edited by the Association of Power Process Industry and Engineering, Japan Disclosure of Invention Problem to be Solved by the Invention [0008] Accordingly, an object of the invention is to provide a method for efficient production of a water-dispersible particulate agricultural-chemical composition having improved disintegrability/dispersibility in water. Means for Solving the Problems [0009] The present inventors have assiduously studied methods for producing granular agricultural-chemical composition and, as a result, have found that a water-dispersible particulate agricultural-chemical composition having a desired particle size range can be extremely efficiently obtained by producing granules according to an extrusion granulation method using a screen having pores slightly larger in diameter than the desired particle size, drying and pulverizing the granules so as not to powder, and further sieving the pulverized particles to have a desired particle size. Thus, the present invention was completed. [0010] Specifically, the present invention may be summarized as follows. (1) A method for producing a water-dispersible particulate agricultural-chemical composition having a particle size within a range of from 50 to 1,000 )µm, the method comprises the following steps (a) to (e): (a) a step of kneading an agricultural-chemical active ingredient, a surfactant and water, (b) a step of extruding the kneaded mixture through a screen having pores from 600 to 2,000 font in diameter to form granules, (c) a step of drying the granules, (d) a step of rotating two toothed rolls with irregularities on the surface arranged in parallel to each other, and leading the dried granules to pass through the toothed rolls thereby- pulverizing the granules, and (e) a step of sieving the pulverized particles. (2) The method for producing a water-dispersible particulate agricultural-chemical composition of the above (1), wherein in the step (e) , the pulverized particles are sieved through two types of meshes each having an opening diameter within a range of from 50 to 1,000 µm. (3) The method for producing a water-dispersible particulate agricultural-chemical composition of the above (2), wherein in the step (e) , the pulverized particles are sieved in such a manner that the particles are first sieved through the mesh having the larger opening diameter of the two types of meshes each having an opening diameter within a range of from 50 to 1,000 µm, then those having passed through the sieve are further sieved through the mesh having the smaller opening diameter, and those having remained on the mesh are collected. Effect of the Invention [0011] In the method for producing a water-dispersible particulate agricultural-chemical composition of the present invention, the material loss in the production process is low and the load to the machines for the production is also low. In addition, the production yield of the water-dispersible particulate agricultural-chemical composition having the intended particle size is high compared with that in conventional production methods. [0012] Accordingly, the method of the present invention is an extremely efficient and economical method for producing a water-dispersible particulate agricultural-chemical composition. Best Mode for Carrying Out the Invention [0013] The term "particle size" as used herein, means the range in which the diameter of the individual particles in the water-dispersible particulate agricultural-chemical composition falls. For example, a water-dispersible particulate agricultural-chemical composition having a particle size of from 250 to 500 µm means the particles which have passed through a mesh having an opening diameter of 500 µm and remain on a mesh having an opening diameter of 250 µm, that is, the composition in which the diameter of all the particles falls within a range of from 250 to 500 µm. [0014] The method of the present invention for producing a water-dispersible particulate agricultural-chemical composition having a particle size within a range of from 50 to 1,000 µm (hereinafter referred to as "the method of the invention") is characterized by comprising the following steps (a) to (e): (a) a step of kneading an agricultural-chemical active ingredient, a surfactant and water, (b) a step of extruding the kneaded mixture through a screen having pores from 600 to 2,000 µm in diameter to form granules, (c) a step of drying the granules, (d) a step of rotating two toothed rolls with irregularities on the surface arranged in parallel to each other, and leading the dried granules to pass through the toothed rolls thereby pulverizing the granules, and (e) a step of sieving the pulverized particles. [0015] The step (a) in the method of the invention is a step of kneading an agricultural-chemical active ingredient, a surfactant and optionally any other ingredient and water. In this step, the above-mentioned ingredients are uniformly mixed, thereby enabling efficient granulation in the next step (b) . Apparatuses for use in the kneading include a Henschel mixer, a twin-arm kneader, a paddle mixer, a blade mixer, a high-speed mixer, a vertical mixer, and the like. The amount of water in kneading may be adjusted to a level suitable for extrusion granulation, and may be from 5 to 30 parts, preferably from 10 to 20 parts relative to the total amount, 100 parts of the above-mentioned agricultural-chemical active ingredient, surfactant and any other optional ingredient. [0016] Prior to being kneaded with water, preferably, the agricultural-chemical active ingredient, the surfactant and the others are mixed and optionally these ingredients are ground into powdery particles having a uniform particle size, using a grinder as typified by an impact grinder, a high-speed airflow-assisted grinder or the like. The mean particle diameter of the ground powdery particles is from 1 to 20 µm, preferably from 1 to 15 µm, more preferably from 2 to 10 µm. The term "mean particle diameter" as referred to herein, means a volume median diameter. [0017] The agricultural-chemical active ingredients include those known in the agricultural-chemical field, such as insecticides, microbicides, herbicides, plant growth regulators, and the like. The agricultural-chemical active ingredients may be in any form of liquid, solid or paste, including the following examples, to which, however, the invention should not be limited. [0018] Specific examples of insecticides include acrinathrin, acetamiprid, acephate, amitraz, alanycarb, arimarua, alumigelure, isoxathion, imidacloprid, indoxacarb MP, uwabarua, ethylthiometon, etoxazole, etofenprox, emamectin benzoate, oxamyl, orifurua, sodium oleate, carbarn ammonium salt, carbarn sodium salt, cadusafos, cartap hydrochloride, carbosulfan, clothianidin, clofentezine, chromafenozide, chloropicrin, chlorpyrifos, chlorpyrifos-methyl, chlorofenapyr, chlorfluazuron, diatomaceous earth, fenbutatin oxide, dienochlor, cycloprothrin, dinotefuran, cyhalothrin, cyfluthrin, diflubenzuron, cypermethrin, fatty acid glycerides, dimethoate, methyl bromide, silafluofen, cyromazine, spinosad, spirodiclofen, sulprofos, diazinon, diamolure, thiacloprid, thiamethoxam, thiodicarb, thiocyclam, thiometon, cheritoria, tetradifon, tetradecenyl acetate, tebufenozide, tebufenpyrad, tefluthrin, teflubenzuron, tralomethrin, tolfenpyrad, nitenpyram, pasteuria penetrans, halfenprox, peachflure, pitoamirua, bifenazate, bifenthrin, pymetrozine, pyraclofos, pyridaphenthion, pyridaben, pyridalyl, pirimarua, pyrimidifen, pirimiphos-methyl, pyrethrin, fipronil, fenothiocarb, fenvalerate, fenpyroximate, fenpropathrin, buprofezin, furathiocarb, fluacrypyrim, flucythrinate, fluvalinate, flufenoxuron, prothiofos, propaphos, propylene glycol fatty acid esters, profenofos, hexythiazox, permethrin, bensultap, benzoepin, benfuracarb, phosalone, fosthiazate, machine oil, marathon, milbemectin, methomyl, metaldehyde, methyl isothiocyanate, methoxyfenozide, litlure, lufenuron, rotenone (derris), BPMC, BPPS, BRP, BT, CYAP, D-D, DCIP, DDVP, DEP, DMTP, ECP, EPN, MEP, MPP, NAC, PAP, XMC, ethiprole. Ethofenprox is preferred among these insecticides. [0019] Specific examples of microbicides include azoxystrobin, amobam, sulfur, isoprothiolane, ipconazole, iprodione, iminoctadine albesilate, iminoctadine acetate, imibenconazole, echlomezole, oxadixyl, oxytetracycline, oxpoconazole fumarate, oxolinic acid, kasugamycin, carpropamid, quinoxalines, captan, kresoxim-methyl, cyazofamid, shiitake mushroom mycelium extract, diethofencarb, diclocymet, diclomezine, dithianon, difenoconazole, cyproconazole, cyflufenamid, cyprodinil, simeconazole, dimethomorph, cymoxanil, Pseudomonas bacteria CAB-02, ziram, streptomycin, lime sulfur mixture, dazomet, potassium bicarbonate, sodium bicarbonate, thiadiazine, tiadinil, thiabendazole, thiuram, thiophanate-methyl, thifluzamide, tecloftalam, tebuconazole, tetraconazole, basic copper chloride, basic copper sulfate, cupric hydroxide, triadimefon, triazine, trichoderma atroviride SKT-1, tricyclazole, triflumizole, trifloxystrobin, triforine, tolclofos-methyl, rapeseed oil, copper nonylphenolsulfonate, Bacillus subtilis bacteria (living cells), validamycin, bitertanol, hydroxyisoxazole, non-pathogenic Erwinia carotovora, pyrifenox, pyribencarb, pyroquilon, famoxadone, fenarimol, fenoxanil, ferimzone, fenbuconazole, fenhexamid, fthalide, Blasticidin S, furametpyr, fluazinam, fluoroimide, fludioxonil, flusulfamide, flutolanil, prochloraz, procymidone, propamocarb hydrochloride, propiconazole, propineb, probenazole, hexaconazole, benomyl, pefurazoate, pencycuron, benthiavalicarb-isopropyl, fosetyl, polyoxin, polycarbamate, manzeb, maneb, mildiomycin, anhydrous copper sulfate, metalaxyl, metominostrobin, mepanipyrim, mepronil, organocopper, DBEDC, EDDP, IBP, TPN, boscalid, and the like. Pyribencarb, benthiavalicarb-isopropyl, iminoctadine albesilate, mepanipyrim and mepronil are preferred among these microbicides. [0020] Specific examples of herbicides include ioxynil, azimsulfuron, asulam, atrazine, anilofos, alachlor, isoxaben, isouron, imazamox ammonium salt, imazosulfuron, indanofan, esprocarb, ethoxysulfuron, etobenzanide, chlorates, oxadiazon, oxaziclomefone, cafenstrole, karbutilate, quizalofop-ethyl, cumyluron, glyphosate ammonium salt, glyphosate isopropylamine salt, glyphosate trimesium salt, glyphosate sodium salt, glufosinate, clethodim, clomeprop, cyanazine, sodium cyanate, cyclosulfamuron, diquat dibromide, siduron, cyhalofop butyl, diflufenican, dimethametryn, dimethenamid, simetryne, dimepiperate, sethoxydim, terbacil, dymron, thifensulfuron-methyl, desmedipham, thenylchlor, tebuthiuron, tepraloxydim, trifluralin, nicosulfuron, paraquat, halosulfuron-methyl, bialaphos, bispyribac sodium salt, bifenox, pyrazoxyfen, pyrazosulfuron-ethyl, pyrazolate, pyraflufen-ethyl, pyriftalid, pyributicarb, pyrimisulfan, pyriminobac-methyl, pyroxasulfone, fenoxaprop-ethyl, fentrazamide, phenmedipham, butachlor, butamifos, flazasulfuron, fluazifop P, pretilachlor, bromacil, prometryn, bromobutide, bensulfuron-methyl, benzobicyclon, benzofenap, bentazone, benthiocarb, pendimethalin, pentoxazone, benfuresate, metamitron, metolachlor, metribuzin, mefenacet, molinate, linuron, lenacil, 2,4 PA, ACN, CAT, DBN, DCMU, DCPA, DPA, IPC, MCPA ethyl, MCPA thioethyl, MCPA sodium salt, MCPB, MDBA, PAC, SAP, and isoxazoline derivatives represented by a formula [I]: [wherein n indicates an integer of from 0 to 2; T1 and T2 each independently represent a hydrogen atom, a halogen atom, a cyano group, a lower alkoxycarbonyl group, or a C1-C6 alkyl group; G1 and G2 each independently represent a hydrogen atom, a C1-C6 alkyl group, or a C1-C6 haloalkyl group; W represents a phenyl group (substituted with from 1 to 5 and the same or different V's); V represents a hydrogen atom, a C1-C6 alkyl group {optionally substituted with from 1 to 3 and the same or different substituents of a halogen atom, a C1-C6 alkoxy group, a hydroxyl group, a C1-C6 alkylthio group, a C1-C6 alkylsulf inyl group, a C1-C6 alkylsulfonyl group, a C1-C6 alkylamino group, a C1-C6 dialkylamino group, a cyano group or a phenoxy group (optionally substituted) }, a C1-C6 alkoxy group (optionally substituted with from 1 to 3 and the same or different substituents of a halogen atom, a C1-C6 alkoxy group, a C2-C6 alkenyl group, a C2-C6 alkynyl group, a C1-C6 alkoxycarbonyl group, a C1-C6 alkylcarbonyl group or a C3-C8 cycloalkyl group), a C3-C8 cycloalkyloxy group, or a halogen atom]. Pyriminobac-methyl, pyrimisulfan, pyroxasulfone and isoxazoline derivatives of formula [I] are preferred among these herbicides. [0021] Specific examples of plant growth regulators include 1-naphthylacetamide, inabenfide, indole butyric acid, uniconazole P, ethyclozate, ethephon, calcium peroxide, cloxyfonac, chlormequat, choline, dichlorprop, gibberellin, daminozide, decyl alcohol, paclobutrazol, prohexadione-calcium, benzylaminopurine, forchlorfenuron, mepiquat-chloride, 4-CPA, and the like. [0022] These agricultural-chemical active ingredients may be used singly, or two or more different types thereof may be used in combination depending on the pests and the weeds to be controlled and the crops to be protected. The total content of the agricultural-chemical active ingredients in the water-dispersible particulate agricultural-chemical composition to be produced according to the method of the invention is not specifically defined, and may be approximately from 1 to 85 parts by weight relative to 100 parts by weight of the composition. [0023] As the surfactant, nonionic surfactants, anionic surfactants, cationic surfactants, ampholytic surfactants, and the like may be used with no limitation. Examples of those types of surfactants are mentioned below, to which, however, the invention should not be limited. [0024] Specific examples of nonionic surfactants include polyoxyalkylene glycols, polyoxyalkylene alkyl ethers, polyoxyalkylene alkyl aryl ethers, polyoxyalkylene fatty acid esters, polyoxyethylene-polyoxypropylene block polymers, sorbitan monoalkylates, alkynols and alkynediols, as well as alkylene oxide adducts thereof. [0025] Specific examples of anionic surfactants include alkali metal salts, alkaline earth metal salts or ammonium salts of alkyl sulfuric acids, alkyl sulfonic acids, alkyl phosphoric acids, alkyl phosphonic acids, alkylaryl sulfonic acids, alkylaryl phosphonic acids, polyoxyalkylene alkyl ether sulfate esters, polyoxyalkylene alkylaryl ether sulfate esters, polyoxyalkylene alkyl ether phosphate esters, polyoxyalkylene alkylaryl ether phosphate esters, polycarboxylic acid-type polymers, lignin sulfonic acids, aryl sulfonic acids, aryl sulfonic acid-formalin condensates, alkylaryl sulfonic acid-formalin condensates, and the like. Salts of alkyl sulfuric acids, alkylaryl sulfonic acids, polycarboxylic acids, lignin sulfonic acids, aryl sulfonic acids, or arylsulfonic acid-formalin condensates are preferred among these anionic surfactants. [0026] Specific examples of cationic surfactants include hydrochlorides, sulfates or carboxylates of alkylamines, polyalkylamines, alkanolamines, polyalkanolamines, polyalkylenepolyamines, alkylpyridines, alkylmorpholines, alkylhydrazines, and the like. [0027] These surfactants may be used singly, or two or more different types thereof may be used in combination. The total content of the surfactants in the water-dispersible particulate agricultural-chemical composition to be produced according to the method of the invention is not specifically defined, and may be approximately from 2 to 30 parts by weight relative to 100 parts by weight of the composition. [0028] Other ingredients that may be optionally added to the above-mentioned agricultural-chemical active ingredient, surfactant and water include those that may be used in ordinary water-dispersible agricultural-chemical composition. For example, formulation additives such as water-soluble fine powder, mineral fine powder, oil-absorbing fine powder, binder, grinding aid, defoaming agent and the like may be optionally incorporated. The water-soluble fine powder includes lactose, water-soluble starch, urea, alkali metal salts or ammonium salts of organic acids or inorganic acids, and the like. The mineral fine powder includes diatomaceous earth, clay, calcium carbonate, and the like. The oil-absorbing fine powder includes white carbon, diatomaceous earth, microcrystalline cellulose, and the like. The binder includes polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, and the like. The grinding aid includes white carbon, silica sand, pumice, and the like. The defoaming agent is not specifically defined, and may include silicone-based surfactants, free long-chain fatty acids or alkali metal salts thereof, and the like. [0029] The mixture kneaded in the above-mentioned step is-then extruded through a screen having pores from 600 to 2,000 µm in diameter to form granules in the next step (b). The pore size of the screen is preferably from 600 to 1,800 µm, more preferably from 600 to 1,500 µm. In cases where the pore size of the screen is smaller than the range, not only does the yield per unit time in extrusion granulation extremely decline but the pressure in passing through the screen increases, leading to increased frequency of screen breakage. On the other hand, when the pore size is larger than the range, the granulation yield per unit time could be large but the efficiency may be undermined because more time is required for drying and the production yield in the step (d) may be decline with increase in unintended fine powder in grinding. The pore size of the screen is preferably from 0.6 to 3 times, more preferably from 0.8 to 2 times the larger opening diameter of the meshes for use in sieving in the step (e). [0030] Any granulator can be used for extrusion granulation as long as the machine is equipped for granulation, and its shape is not specifically defined. Specific examples of the granulator include a horizontal extrusion-type screw-extrusion granulator, a disc die-type roll-extrusion granulator, a basket-type blade-extrusion granulator, and the like. [0031] The granules formed as above are then dried in the step (c) . Using a drier such as a fluidized bed drier or the like, the granules are dried at a hot air temperature of from 50 to 100°C or so for 10 to 20 minutes or so. In the operation, the intralayer temperature in the granules rises to the same level as that of the hot air temperature and the water content thereof decreases generally to 0.5 to 3% by mass. When not dried, the granules may be again kneaded together by the rotational movement of the pulverizer in the next step (d) and therefore the granules could not be pulverized. [0032] The granules obtained in the above-mentioned step are in the form of columns having a constant size, having each of the ingredients uniformly dispersed therein, and are in a consolidated state (a strongly-compacted state having a uniform density). [0033] The granules are then subjected to the step (d) . In the step, two toothed rolls with irregularities formed on the surface are arranged in parallel to each other with a predetermined distance, and these toothed rolls are rotated. Then the dried granules are led to pass through the rotating rolls for pulverization. Through this step, the pulverized particles comprising a lot of granules of a desired particle size can be obtained to enable efficient production of the water-dispersible particulate agricultural-chemical composition having a desired particle size range. In this step, preferably, the toothed rolls are arranged in parallel to the ground and the dried granules are thrown from above into the toothed rolls. [0034] The toothed rolls for use in this step each have irregularities formed on the roll surface. In general, the diameter of the roll is from 50 mm to 300 mm and the length thereof is from 20 mm to 1,500 mm. The shape of the irregularities of the toothed rolls is not specifically defined. Preferably, the cross section of the irregularities has a profile of continuous triangular mounds. The shape of the triangles is not also specifically defined. Preferably, the height and the width (base) of the triangle fall within a range of from 0.3 mm to 10 mm and more preferably, the height and the width are the same. Further, the distance between the rolls is not specifically defined, and in general, it may be from 0.05 mm to 1.5 mm. The size of the pulverized particles can be controlled by changing the shape of the teeth of the rolls and the distance between the rolls. In general, when the height and the width of the triangles of the teeth are narrower, and when the distance between the rolls is narrower, the pulverized particles may be smaller. The apparatus for such pulverizing may be a frame-type pulverizing apparatus. [0035] In the present invention, the particles pulverized as in the above may be further pulverized by using two or more of the above-mentioned pair of two toothed rolls in combination. In this case, preferably, the shape of the teeth of the rolls and the distance between the rolls are so configured that the latter pulverizing could give particles having a smaller particle size than the first pulverizing. A combination of these toothed rolls comprises, for example, rolls with triangle teeth having a height and a width of 1 mm each, arranged at the distance of 0.27 mm for the first pulverization; and rolls with triangle teeth having a height and a width of 0.6 mm each, arranged at the distance of 0.25 mm for the latter pulverization. [0036] The particles pulverized as in the above are then sieved in the step (e). The sieving is conducted to obtain the water-dispersible particulate agricultural-chemical composition having a particle size within a range of from 50 to 1,000 µm, preferably from 100 to 850 µm, more preferably from 250 to 700 µm. Concretely, the sieving may be attained by the use of two types of meshes each having an opening diameter within a range of from 50 to 1,000 µm. More concretely, the pulverized particles are first sieved through the mesh having the larger opening diameter of the two types of meshes each having an opening diameter within a range of from 50 to 1,000 µm, then the particles having passed through the sieve are further sieved through the mesh having the smaller opening diameter, and those having remained on the mesh are collected. For example, the water-dispersible particulate agricultural-chemical composition having a particle size of from 250 to 600 µm can be obtained by first sieving the pulverized particles through a mesh having an opening diameter of 600 µm, then further sieving those having passed through it, through a mesh having an opening diameter of 250 µm, and collecting those having remained on the mesh. The machine for the sieving includes a rotary shifter, a shaking sieve, and the like. [0037] According to the steps (a) to (e) described above, the water-dispersible particulate agricultural-chemical composition having a particle size of from 50 to 1,000 µm can be produced efficiently. [0038] The water-dispersible particulate agricultural-chemical composition thus produced is excellent in disintegrability/dispersibility in water. [0039] In the present invention, the reason why the water-dispersible particulate agricultural-chemical composition having a particle size of from 50 to 1,000 µm can be produced efficiently is because a uniform kneaded mixture of ingredients such as an agricultural-chemical active ingredient and others is produced in the step (a), and then granules having a shape of columns with a constant size in a consolidated state are produced in the step (b) . In addition, when the granules dried in the step (c) are led to pass through two toothed rolls used in the latter-stage of the step (d) , almost all the granules are cut from the side of each column to be pulverized since the granules have a shape of columns with a constant size; and while they are pulverized, the consolidated structure of the granules prevents generation of large amount of unintended fine powder, with the result that the water-dispersible particulate agricultural-chemical composition having a desired particle size can be obtained efficiently in a high production yield. [0040] On the other hand, when the ingredients of the granules to be processed in the step (d) are not homogeneous, when the density of the granules is not uniform, or when the granules are amorphous, then the particles pulverized in the step (d) have a broad particle size distribution, and in particular, unintended fine particles are formed much, resulting in a low production yield. Examples [0041] The present invention will be described in more detail with reference to Examples and Comparative Examples; however, the invention should not be limited to these Examples. In the following Examples, the term "part" means part by weight. [0042] Example 1 40 parts of pyribencarb, 4 parts of sodium alkyl sulfate, 5 parts of sodium lignin sulfonate, and 51 parts of calcium carbonate were mixed, and ground with a high-speed airflow-assisted grinder so that the mean particle size of the ingredients could be 7 µm. Next, 15 parts of water was added to 100 parts of the ground particles, and further kneaded. At the time when the added water had penetrated into the whole mixture, the kneaded mixture was granulated with a horizontal extrusion-type screw-extrusion granulator. The screen used in extrusion granulation had pores 800 µm in diameter. The obtained granules were dried in a fluidized bed drier at a hot air temperature of 55°C for about 10 minutes until the intralayer temperature could reach 55°C. Subsequently, using a frame-type pulverizing apparatus having two toothed rolls arranged in parallel to the ground and having a slot above the rolls, the dried granules were led to pass through the rotating rolls in this apparatus and pulverized. The height and the width of the triangles of the teeth were both 0.6 mm and the distance between the rolls was 0.25 mm. The pulverized particles were then sieved through a mesh having an opening diameter of 500 µm, and those having passed through the mesh were further sieved through a mesh having an opening diameter of 250 µm; and those having remained on the mesh were collected to obtain a water-dispersible particulate agricultural-chemical composition having a particle size within a range of from 250 to 500 µm. [0043] Example 2 40 parts of pyribencarb, 4 parts of sodium alkyl sulfate, 5 parts of sodium lignin sulfonate, and 51 parts of calcium carbonate were mixed, and ground with a high-speed airflow-assisted grinder so that the mean particle size of the ingredients could be 7 µm. Next, 15 parts of water was added to 100 parts of the ground particles, and further kneaded. At the time when the added water had penetrated into the whole mixture, the kneaded mixture was granulated with a horizontal extrusion-type screw-extrusion granulator. The screen used in extrusion granulation had pores 1,800 fim in diameter. The obtained granules were dried in a fluidized bed drier at a hot air temperature of 55°C for about 20 minutes until the intralayer temperature could reach 55°C. Subsequently, using a frame-type pulverizing apparatus having two pairs of toothed rolls arranged one above the other in parallel to the ground and having a slot above the rolls, the dried granules were led to pass through the rotating rolls in this apparatus and pulverized. The height and the width of the triangles of the teeth were both 1.5 mm and the distance between the rolls was 0.8 mm in the upper pair of rolls; and the height and the width were both 0.6 mm and the distance was 0.25 mm in the lower pair of rolls. The pulverized particles were then sieved through a mesh having an opening diameter of 500 µm, and those having passed through the mesh were further sieved through a mesh having an opening diameter of 250 µm; and those having remained on the mesh were collected to obtain a water-dispersible particulate agricultural-chemical composition having a particle size within a range of from 250 to 500 µm. [0044] Example 3 40 parts of mepanipyrim, 2 parts of sodium alkyl sulfate, 8 parts of sodium lignin sulfonate, and 50 parts of clay were mixed, and ground with a high-speed airflow-assisted grinder so that the mean particle size of the ingredients could be 5 µm. Next, 18 parts of water was added to 100 parts of the ground particles, and further kneaded. At the time when the added water had penetrated into the whole mixture, the kneaded mixture was granulated with a horizontal extrusion-type screw-extrusion granulator. The screen used in extrusion granulation had pores 1, 000 µm in diameter. The obtained granules were dried in a fluidized bed drier at a hot air temperature of 55°C for about 10 minutes until the intralayer temperature could reach 55°C. Subsequently, using a frame-type pulverizing apparatus having two toothed rolls arranged in parallel to the ground and having a slot above the rolls, the dried granules were led to pass through the rotating rolls in this apparatus and pulverized. The height and the width of the triangles of the teeth were both 0.6 mm and the distance between the rolls was 0.25 mm. The pulverized particles were then sieved through a mesh having an opening diameter of 600 µm, and those having passed through the mesh were further sieved through a mesh having an opening diameter of 150 µm; and those having remained on the mesh were collected to obtain a water-dispersible particulate agricultural-chemical composition having a particle size within a range of from 150 to 600 µm. [0045] Example 4 10 parts of pyribencarb, 30 parts of a mixture (1/1 by weight) of iminoctadine albesilate and white carbon, 4 parts of sodium alkyl sulfate, 15 parts of maleic anhydride-isobutylene copolycondensate, and 41 parts of calcium carbonate were mixed, and ground with a high-speed airflow-assisted grinder so that the mean particle size of the ingredients could be 9 µm. Next, 20 parts of water was added to 100 parts of the ground particles, and further kneaded. At the time when the added water had penetrated into the whole mixture, the kneaded mixture was granulated with a horizontal extrusion-type screw-extrusion granulator. The screen used in extrusion granulation had pores 600 µm in diameter. The obtained granules were dried in a fluidized bed drier at a hot air temperature of 55°C for about 10 minutes until the intralayer temperature could reach 55°C. Subsequently, using a frame-type pulverizing apparatus having two toothed rolls arranged in parallel to the ground and having a slot above the rolls, the dried granules were led to pass through the rotating rolls in this apparatus and pulverized. The height and the width of the triangles of the teeth were both 0.6 mm and the distance between the rolls was 0.25 mm. The pulverized particles were then sieved through a mesh having an opening diameter of 600 µm, and those having passed through the mesh were further sieved through a mesh having an opening diameter of 150 µm; and those having remained on the mesh were collected to obtain a water-dispersible particulate agricultural-chemical composition having a particle size within a range of from 150 to 600 µm. [0046] Example 5 50 parts of pyriminobac-methyl, 20 parts of sodium alkylnaphthalene sulfonate-formalin condensate, 1 part of polyoxyalkylene alkylaryl ether, and 29 parts of calcined diatomaceous earth were mixed, and ground with a high-speed airflow-assisted grinder so that the mean particle size of the ingredients could be 4 µm. Next, 15 parts of water was added to 100 parts of the ground particles, and further kneaded. At the time when the added water had penetrated into the whole mixture, the kneaded mixture was granulated with a horizontal extrusion-type screw-extrusion granulator. The screen used in extrusion granulation had pores 700 µm in diameter. The obtained granules were dried in a fluidized bed drier at a hot air temperature of 55°C for about 10 minutes until the intralayer temperature could reach 55°C. Subsequently, using a frame-type pulverizing apparatus having two toothed rolls arranged in parallel to the ground and having a slot above the rolls, the dried granules were led to pass through the rotating rolls in this apparatus and pulverized. The height and the width of the triangles of the teeth were both 0.6 mm and the distance between the rolls was 0.25 mm. The pulverized particles were then sieved through a mesh having an opening diameter of 500 µm, and those having passed through the mesh were further sieved through a mesh having an opening diameter of 250 µm; and those having remained on the mesh were collected to obtain a water-dispersible particulate agricultural-chemical composition having a particle size within a range of from 250 to 500 µm. [0047] Example 6 85 parts of pyroxasulfone, 3 parts of sodium alkylnaphthalene sulfonate-formalin condensate, 8 parts of sodium lignin sulfonate, 1 part of polyoxyalkylene aryl ether, and 3 parts of calcined diatomaceous earth were mixed, and ground with a high-speed airflow-assisted grinder so that the mean particle size of the ingredients could be 5 µm. Next, 15 parts of water was added to 100 parts of the ground particles, and further kneaded. At the time when the added water had penetrated into the whole mixture, the kneaded mixture was granulated with a horizontal extrusion-type screw-extrusion granulator. The screen used in extrusion granulation had pores 800 µm in diameter. The obtained granules were dried in a fluidized bed drier at a hot air temperature of 55°C for about 10 minutes until the intralayer temperature could reach 55°C. Subsequently, using a frame-type pulverizing apparatus having two toothed rolls arranged in parallel to the ground and having a slot above the rolls, the dried granules were led to pass through the rotating rolls in this apparatus and pulverized. The height and the width of the triangles of the teeth were both 0.6 mm and the distance between the rolls was 0.25 mm. The pulverized particles were then sieved through a mesh having an opening diameter of 500 µm, and those having passed through the mesh were further sieved through a mesh having an opening diameter of 250 µm; and those having remained on the mesh were collected to obtain a water-dispersible particulate agricultural-chemical composition having a particle size within a range of from 250 to 500 µm. [0048] Comparative Example 1 40 parts of pyribencarb, 4 parts of sodium alkyl sulfate, 5 parts of sodium lignin sulfonate, and 51 parts of calcium carbonate were mixed, and ground with a high-speed airflow-assisted grinder so that the mean particle size of the ingredients could be 7 µm. Next, 15 parts of water was added to 100 parts of the ground particles, and further kneaded. At the time when the added water had penetrated into the whole mixture, the kneaded mixture was granulated with a horizontal extrusion-type screw-extrusion granulator. The screen used in extrusion granulation had pore 300 µm in diameter. However, since the screen was broken and the granulation could not be attained, the intended water-dispersible particulate agricultural-chemical composition could not be obtained. [0049] Comparative Example 2 40 parts of pyribencarb, 4 parts of sodium alkyl sulfate, 5 parts of sodium lignin sulfonate, and 51 parts of calcium carbonate were mixed, and ground with a high-speed airflow-assisted grinder so that the mean particle size of the ingredients could be 7 µm. Next, 15 parts of water was added to 100 parts of the ground particles, and further kneaded. At the time when the added water had penetrated into the whole mixture, the kneaded mixture was granulated with a horizontal extrusion-type screw-extrusion granulator. The screen used in extrusion granulation had pores 3,000 µm in diameter. The obtained granules were dried in a fluidized bed drier at a hot air temperature of 55°C for about 20 minutes until the intralayer temperature could reach 55°C. Subsequently, using a frame-type pulverizing apparatus having three pairs of toothed rolls arranged in upper, middle and lower three stages so as to be in parallel to the ground and having a slot above the rolls, the dried granules were led to pass through the rotating rolls in this apparatus and pulverized. The height and the width of the triangles of the teeth were both 2.0 mm and the distance between the rolls was 1.5 mm in the upper pair of rolls; the height and the width were both 1.5 mm and the distance was 0.8 mm in the middle pair of rolls; and the height and the width were both 0.6 mm and the distance was 0.25 mm in the lower pair of rolls. The pulverized particles were then sieved through a mesh having an opening diameter of 500 µm, and those having passed through the mesh were further sieved through a mesh having an opening diameter of 250 µm; and those having remained on the mesh were collected to obtain a water-dispersible particulate agricultural-chemical composition having a particle size within a range of from 250 to 500 µm. [0050] Comparative Example 3 40 parts of pyribencarb, 4 parts of sodium alkyl sulfate, 5 parts of sodium lignin sulfonate, and 51 parts of calcium carbonate were mixed, and ground with a high-speed airflow-assisted grinder so that the mean particle size of the ingredients could be 7 urn. Next, with spraying 15 parts of water onto 100 parts of the ground particles, granules having a particle size of from 100 to 5,000 µm or so were obtained by means of a stirring granulator. The obtained granules were dried in a fluidized bed drier at a hot air temperature of 55°C for about 10 minutes until the intralayer temperature could reach 55°C. Subsequently, using a frame-type pulverizing apparatus having two toothed rolls arranged in parallel to the ground and having a slot above the rolls, the dried granules were led to pass through the rotating rolls in this apparatus and pulverized. The height and the width of the triangles of the teeth were both 0.6 mm and the distance between the rolls was 0.25 mm. The pulverized particles were then sieved through a mesh having an opening diameter of 500 µm, and those having passed through the mesh were further sieved through a mesh having an opening diameter of 250 µm; and those having remained on the mesh were collected to obtain a water-dispersible particulate agricultural-chemical composition having a particle size within a range of from 250 to 500 µm. [0051] Comparative Example 4 40 parts of pyribencarb, 4 parts of sodium alkyl sulfate, 5 parts of sodium lignin sulfonate, and 51 parts of calcium carbonate were mixed, and ground with a high-speed airflow-assisted grinder so that the mean particle size of the ingredients could be 7 µm. Next, with spraying 15 parts of water onto 100 parts of the ground particles, granules having a particle size of from 100 to 5,000 µm or so were obtained by means of a stirring granulator. Using a frame-type pulverizing apparatus having two toothed rolls arranged in parallel to the ground and having a slot above the rolls, the obtained granules were, without being dried, led to pass through the rotating rolls in this apparatus so as to be pulverized. However, since the granules were again kneaded together between the rolls and could not be pulverized, the intended water-dispersible particulate agricultural-chemical composition could not be obtained. The height and the width of the triangles of the teeth were both 0.6 mm and the distance between the rolls was 0.25 mm. [0052] Comparative Example 5 10 parts of pyribencarb, 30 parts of a mixture (1/1 by weight) of iminoctadine albesilate and white carbon, 4 parts of sodium alkyl sulfate, 15 parts of sodium naphthalenesulfonate-formaldehyde condensate, and 41 parts of calcium carbonate were mixed, and ground with a high-speed airflow-assisted grinder so that the mean particle size of the ingredients could be 9 µm. Next, 20 parts of water was added to 100 parts of the ground particles, and further kneaded. At the time when the added water had penetrated into the whole mixture, the kneaded mixture was granulated with a horizontal extrusion-type screw-extrusion granulator. The screen used in extrusion granulation had pores 600 µm in diameter. The obtained granules were dried in a fluidized bed drier at a hot air temperature of 55°C for about 10 minutes until the intralayer temperature could reach 55°C. The dried granules were sieved through a mesh having an opening diameter of 600 µm, and those having passed through the mesh were further sieved through a mesh having an opening diameter of 150 µm; and those having remained on the mesh were collected to obtain a water-dispersible particulate agricultural-chemical composition having a particle size within a range of from 150 to 600 µm. [0053] Test Example 1 Disintegration Test: 0.3077 g of calcium carbonate and 0.092 g of magnesium oxide were dissolved in a small amount of diluted hydrochloric acid, then heated and boiled on a sand bath to remove hydrochloric acid. Distilled water was added to the remaining solution to make 10 liters in total. Subsequently, 100 ml of the obtained solution was put into a 100-ml stoppered measuring cylinder, and kept at 20°C in a temperature-controlled room. 100 mg of the water-dispersible particulate agricultural-chemical composition produced in Examples 1 to 6 and Comparative Example 5 was put into the measuring cylinder, statically left as it was for 30 seconds, and then the measuring cylinder was turned upside down repeatedly in a ratio of once a second, whereupon the turning-down frequency needed for disintegrating the whole water-dispersible particulate agricultural-chemical composition was counted. The results are shown in Table 1. [0054] Table 1 [0055] From Table 1, it is known that the water-dispersible particulate agricultural-chemical compositions of the present invention have high disintegrability in water and are excellent in dispersibility. [0056] Test Example 2 Evaluation of Production Efficiency: Using starting materials of 10 kg in total, water-dispersible particulate agricultural-chemical compositions were produced according to the above-mentioned Examples and Comparative Examples, and the weight of the finally-obtained water-dispersible particulate agricultural-chemical composition was measured. The results are shown in Table 2. [0057] Table 2 [0058] From Table 2, it is known that the method for producing a water-dispersible particulate agricultural-chemical composition of the present invention provides a high production yield and is excellent in production efficiency. Industrial Applicability [0059] According to the method for producing a water-dispersible particulate agricultural-chemical composition of the present invention, a loss of starting materials in the production process is small, a load to the machine for the production is low, and the production yield of the water-dispersible particulate agricultural-chemical composition having a desired particle size is high as compared with conventional production methods. [0060] Therefore, the method of the present invention can be advantageously used in producing a water-dispersible particulate agricultural-chemical composition for use in controlling pests and weeds for agricultural/horticultural crops. CLAIMS 1. A method for producing a water-dispersible particulate agricultural-chemical composition having a particle size within a range of from 50 to 1,000 µm, the method comprising the following steps (a) to (e): (a) a step of kneading an agricultural-chemical active ingredient, a surfactant and water, (b) a step of extruding the kneaded mixture through a screen having pores from 600 to 2,000 µm in diameter to form granules, (c) a step of drying the granules, (d) a step of rotating two toothed rolls with irregularities on the surface arranged in parallel to each other, and leading the dried granules to pass through the toothed rolls thereby pulverizing the granules, and (e) a step of sieving the pulverized particles. 2. The method for producing a water-dispersible particulate agricultural-chemical composition according to claim 1, wherein in the step (e), the pulverized particles are sieved through two types of meshes each having an opening diameter within a range of from 50 to 1,000 µm. 3. The method for producing a water-dispersible particulate agricultural-chemical composition according to claim 2, wherein in the step (e), the pulverized particles are first sieved through the mesh having the larger opening diameter of the two types of meshes each having an opening diameter within a range of from 50 to 1,000 µm, then those having passed through the sieve are further sieved through the mesh having the smaller opening diameter, and those having remained on the mesh are collected. A process for efficiently producing a water-dispersible particulate agricultural-chemical composition having improved disintegrability/dispersibility in water, the composition having a particular size in the range of 50 - 1,000 µm. The process is characterized by comprising the following steps (a) to (e) : (a) a step of kneading an agricultural-chemical active ingredient, a surfactant, and water; (b) a step of extruding the resultant mixture through a screen having pores 600 - 2,000 µm in diameter to form granules; (c) a step of drying the granules; (d) a step of rotating two toothed rolls with irregularities on the surface arranged in parallel to each other, and leading the dried granules to pass between the toothed rolls thereby pulverizing the granules; and (e) a step of sieving the pulverized granules.

Full Text

DESCRIPTION
PROCESS FOR PRODUCING WATER-DISPERSIBLE PARTICULATE
AGRICULTURAL-CHEMICAL COMPOSITION
Technical Field
[0001]
The present invention relates to a process for producing
a water-dispersible particulate agricultural-chemical
composition for use in controlling pests and weeds for
agricultural/horticultural crops.
Background Art
[0002]
Heretofore, various types of agricultural-chemical
formulations such as dusts, granules, wettable powders,
water-dispersible particulates, liquids, aqueous suspensions,
emulsifiable concentrates, and the like have been known. Of these
agricultural-chemical formulations, water-dispersible
particulates are easy for users to handle since they do not powder
during use thereof and therefore users would be exposed little
to the agricultural-chemical ingredient and since they are easy
to meter. Accordingly, forms of recent agricultural-chemical
formulations tend to be changed from wettable powders to
water-dispersible particulates.
[0003]
In general water-dispersible particulates should easily
disperse in water, and for this purpose they should be produced
by a method in which granulation is not accompanied by application
of pressure and the resulting granules are free from a consolidated
structure. Such methods include a so-called fluidized-bed
granulation method where a powdery mixture of an
agricultural-chemical active ingredient, a surfactant and an
extender or the like is fluidized in a layer into which hot air
is pumped, and an aqueous solution containing a binder is sprayed
thereon to make the powdery particles aggregate together thereby
forming granules; and a so-called stirring granulation method
where an aqueous solution containing a binder is sprayed on a
powdery mixture of an agricultural-chemical active ingredient,
a surfactant and an extender or the like kept stirred at high speed
to make the powdery particles aggregate together thereby forming

granules (Non-Patent Documents 1 and 2).
[0004]
In these methods, however, the granules produced have a broad
particle size distribution and sieving results in a low production
yield with respect to a necessary particle size. In addition,
since the granulation is carried out as a batch process, the amount
of the granules to be produced per unit time is small. Therefore,
the methods are substantially unsuitable for industrial
production of agricultural chemicals.
[0005]
On the other hand, as a granulation method that secures high
producibility of agricultural-chemical formulations, there is a
so-called extrusion granulation method where an
agricultural-chemical active ingredient, a surfactant and an
extender or the like are kneaded with water, and extruded through
pores formed in a screen to give columnar granules (Non-Patent
Document 1) . In this method, a high pressure is given to extrude
the mixture through the pores and, as a result, the formed granules
have a consolidated structure with poor water-dispersibility. In
this connection, while the water-dispersibility could be improved
by reducing the diameter of the pores to have smaller granules,
the pressure to be imparted to the screen may increase with
reduction in the diameter of the pores and cause increased
fragility of the screen thereby precluding the granulation itself.
[0006]
Also, as a method for producing a granular
agricultural-chemical composition having improved
water-dispersibility and suspensibility of
agricultural-chemical ingredient, there is a method in which a
mixture containing an agricultural-chemical active ingredient and
a surfactant is kneaded with water, and the kneaded mixture is
pulverized to have a predetermined particle size and dried, or
the kneaded mixture is dried and made to have a predetermined
particle size (Patent Document 1) . In this method, although the
resulting granules are not in a consolidated state and have good
water-dispersibility, the step of pulverizing the kneaded mixture
may cause problems. Specifically, in the case where the kneaded
mixture before dried is pulverized, the mixture significantly
adheres to the pulverizer because of water contained in the mixture
On the other hand, the kneaded mixture which is dried before the
pulverization is extremely brittle and the size distribution of

the pulverized particles is large, therefore the production yield
of the granular agricultural-chemical composition having the
intended particle size is extremely low.
[0007]
Patent Document 1: JP-A 2001-288004
Non-Patent Document 1: Handbook of Granulation Technology,
edited by the Association of Power Process Industry and
Engineering, Japan
Non-Patent Document 2: Granulation Manual, edited by the
Association of Power Process Industry and Engineering, Japan
Disclosure of Invention
Problem to be Solved by the Invention
[0008]
Accordingly, an object of the invention is to provide a
method for efficient production of a water-dispersible
particulate agricultural-chemical composition having improved
disintegrability/dispersibility in water.
Means for Solving the Problems
[0009]
The present inventors have assiduously studied methods for
producing granular agricultural-chemical composition and, as a
result, have found that a water-dispersible particulate
agricultural-chemical composition having a desired particle size
range can be extremely efficiently obtained by producing granules
according to an extrusion granulation method using a screen having
pores slightly larger in diameter than the desired particle size,
drying and pulverizing the granules so as not to powder, and further
sieving the pulverized particles to have a desired particle size.
Thus, the present invention was completed.
[0010]
Specifically, the present invention may be summarized as
follows.
(1) A method for producing a water-dispersible particulate
agricultural-chemical composition having a particle size within
a range of from 50 to 1,000 )µm, the method comprises the following
steps (a) to (e):
(a) a step of kneading an agricultural-chemical active
ingredient, a surfactant and water,
(b) a step of extruding the kneaded mixture through a screen

having pores from 600 to 2,000 font in diameter to form granules,
(c) a step of drying the granules,
(d) a step of rotating two toothed rolls with irregularities
on the surface arranged in parallel to each other, and leading
the dried granules to pass through the toothed rolls thereby-
pulverizing the granules, and
(e) a step of sieving the pulverized particles.
(2) The method for producing a water-dispersible particulate
agricultural-chemical composition of the above (1), wherein in
the step (e) , the pulverized particles are sieved through two types
of meshes each having an opening diameter within a range of from
50 to 1,000 µm.
(3) The method for producing a water-dispersible particulate
agricultural-chemical composition of the above (2), wherein in
the step (e) , the pulverized particles are sieved in such a manner
that the particles are first sieved through the mesh having the
larger opening diameter of the two types of meshes each having
an opening diameter within a range of from 50 to 1,000 µm, then
those having passed through the sieve are further sieved through
the mesh having the smaller opening diameter, and those having
remained on the mesh are collected.
Effect of the Invention
[0011]
In the method for producing a water-dispersible particulate
agricultural-chemical composition of the present invention, the
material loss in the production process is low and the load to
the machines for the production is also low. In addition, the
production yield of the water-dispersible particulate
agricultural-chemical composition having the intended particle
size is high compared with that in conventional production
methods.
[0012]
Accordingly, the method of the present invention is an
extremely efficient and economical method for producing a
water-dispersible particulate agricultural-chemical
composition.
Best Mode for Carrying Out the Invention
[0013]
The term "particle size" as used herein, means the range

in which the diameter of the individual particles in the
water-dispersible particulate agricultural-chemical composition
falls. For example, a water-dispersible particulate
agricultural-chemical composition having a particle size of from
250 to 500 µm means the particles which have passed through a mesh
having an opening diameter of 500 µm and remain on a mesh having
an opening diameter of 250 µm, that is, the composition in which
the diameter of all the particles falls within a range of from
250 to 500 µm.
[0014]
The method of the present invention for producing a
water-dispersible particulate agricultural-chemical composition
having a particle size within a range of from 50 to 1,000 µm (hereinafter referred to as "the method of the invention") is
characterized by comprising the following steps (a) to (e):
(a) a step of kneading an agricultural-chemical active
ingredient, a surfactant and water,
(b) a step of extruding the kneaded mixture through a screen
having pores from 600 to 2,000 µm in diameter to form granules,
(c) a step of drying the granules,
(d) a step of rotating two toothed rolls with irregularities
on the surface arranged in parallel to each other, and leading
the dried granules to pass through the toothed rolls thereby
pulverizing the granules, and
(e) a step of sieving the pulverized particles.
[0015]
The step (a) in the method of the invention is a step of
kneading an agricultural-chemical active ingredient, a surfactant
and optionally any other ingredient and water. In this step, the
above-mentioned ingredients are uniformly mixed, thereby enabling
efficient granulation in the next step (b) . Apparatuses for use
in the kneading include a Henschel mixer, a twin-arm kneader, a
paddle mixer, a blade mixer, a high-speed mixer, a vertical mixer,
and the like. The amount of water in kneading may be adjusted
to a level suitable for extrusion granulation, and may be from
5 to 30 parts, preferably from 10 to 20 parts relative to the total
amount, 100 parts of the above-mentioned agricultural-chemical
active ingredient, surfactant and any other optional ingredient.
[0016]
Prior to being kneaded with water, preferably, the
agricultural-chemical active ingredient, the surfactant and the

others are mixed and optionally these ingredients are ground into
powdery particles having a uniform particle size, using a grinder
as typified by an impact grinder, a high-speed airflow-assisted
grinder or the like. The mean particle diameter of the ground
powdery particles is from 1 to 20 µm, preferably from 1 to 15 µm,
more preferably from 2 to 10 µm. The term "mean particle diameter"
as referred to herein, means a volume median diameter.
[0017]
The agricultural-chemical active ingredients include those
known in the agricultural-chemical field, such as insecticides,
microbicides, herbicides, plant growth regulators, and the like.
The agricultural-chemical active ingredients may be in any form
of liquid, solid or paste, including the following examples, to
which, however, the invention should not be limited.
[0018]
Specific examples of insecticides include acrinathrin,
acetamiprid, acephate, amitraz, alanycarb, arimarua, alumigelure,
isoxathion, imidacloprid, indoxacarb MP, uwabarua,
ethylthiometon, etoxazole, etofenprox, emamectin benzoate,
oxamyl, orifurua, sodium oleate, carbarn ammonium salt, carbarn
sodium salt, cadusafos, cartap hydrochloride, carbosulfan,
clothianidin, clofentezine, chromafenozide, chloropicrin,
chlorpyrifos, chlorpyrifos-methyl, chlorofenapyr,
chlorfluazuron, diatomaceous earth, fenbutatin oxide, dienochlor,
cycloprothrin, dinotefuran, cyhalothrin, cyfluthrin,
diflubenzuron, cypermethrin, fatty acid glycerides, dimethoate,
methyl bromide, silafluofen, cyromazine, spinosad, spirodiclofen,
sulprofos, diazinon, diamolure, thiacloprid, thiamethoxam,
thiodicarb, thiocyclam, thiometon, cheritoria, tetradifon,
tetradecenyl acetate, tebufenozide, tebufenpyrad, tefluthrin,
teflubenzuron, tralomethrin, tolfenpyrad, nitenpyram, pasteuria
penetrans, halfenprox, peachflure, pitoamirua, bifenazate,
bifenthrin, pymetrozine, pyraclofos, pyridaphenthion, pyridaben,
pyridalyl, pirimarua, pyrimidifen, pirimiphos-methyl, pyrethrin,
fipronil, fenothiocarb, fenvalerate, fenpyroximate,
fenpropathrin, buprofezin, furathiocarb, fluacrypyrim,
flucythrinate, fluvalinate, flufenoxuron, prothiofos, propaphos,
propylene glycol fatty acid esters, profenofos, hexythiazox,
permethrin, bensultap, benzoepin, benfuracarb, phosalone,
fosthiazate, machine oil, marathon, milbemectin, methomyl,
metaldehyde, methyl isothiocyanate, methoxyfenozide, litlure,
lufenuron, rotenone (derris), BPMC, BPPS, BRP, BT, CYAP, D-D, DCIP,
DDVP, DEP, DMTP, ECP, EPN, MEP, MPP, NAC, PAP, XMC, ethiprole.
Ethofenprox is preferred among these insecticides.
[0019]
Specific examples of microbicides include azoxystrobin,
amobam, sulfur, isoprothiolane, ipconazole, iprodione,
iminoctadine albesilate, iminoctadine acetate, imibenconazole,
echlomezole, oxadixyl, oxytetracycline, oxpoconazole fumarate,
oxolinic acid, kasugamycin, carpropamid, quinoxalines, captan,
kresoxim-methyl, cyazofamid, shiitake mushroom mycelium extract,
diethofencarb, diclocymet, diclomezine, dithianon,
difenoconazole, cyproconazole, cyflufenamid, cyprodinil,
simeconazole, dimethomorph, cymoxanil, Pseudomonas bacteria
CAB-02, ziram, streptomycin, lime sulfur mixture, dazomet,
potassium bicarbonate, sodium bicarbonate, thiadiazine, tiadinil,
thiabendazole, thiuram, thiophanate-methyl, thifluzamide,
tecloftalam, tebuconazole, tetraconazole, basic copper chloride,
basic copper sulfate, cupric hydroxide, triadimefon, triazine,
trichoderma atroviride SKT-1, tricyclazole, triflumizole,
trifloxystrobin, triforine, tolclofos-methyl, rapeseed oil,
copper nonylphenolsulfonate, Bacillus subtilis bacteria (living
cells), validamycin, bitertanol, hydroxyisoxazole,
non-pathogenic Erwinia carotovora, pyrifenox, pyribencarb,
pyroquilon, famoxadone, fenarimol, fenoxanil, ferimzone,
fenbuconazole, fenhexamid, fthalide, Blasticidin S, furametpyr,
fluazinam, fluoroimide, fludioxonil, flusulfamide, flutolanil,
prochloraz, procymidone, propamocarb hydrochloride,
propiconazole, propineb, probenazole, hexaconazole, benomyl,
pefurazoate, pencycuron, benthiavalicarb-isopropyl, fosetyl,
polyoxin, polycarbamate, manzeb, maneb, mildiomycin, anhydrous
copper sulfate, metalaxyl, metominostrobin, mepanipyrim,
mepronil, organocopper, DBEDC, EDDP, IBP, TPN, boscalid, and the
like. Pyribencarb, benthiavalicarb-isopropyl, iminoctadine
albesilate, mepanipyrim and mepronil are preferred among these
microbicides.
[0020]
Specific examples of herbicides include ioxynil,
azimsulfuron, asulam, atrazine, anilofos, alachlor, isoxaben,
isouron, imazamox ammonium salt, imazosulfuron, indanofan,
esprocarb, ethoxysulfuron, etobenzanide, chlorates, oxadiazon,
oxaziclomefone, cafenstrole, karbutilate, quizalofop-ethyl,

cumyluron, glyphosate ammonium salt, glyphosate isopropylamine
salt, glyphosate trimesium salt, glyphosate sodium salt,
glufosinate, clethodim, clomeprop, cyanazine, sodium cyanate,
cyclosulfamuron, diquat dibromide, siduron, cyhalofop butyl,
diflufenican, dimethametryn, dimethenamid, simetryne,
dimepiperate, sethoxydim, terbacil, dymron,
thifensulfuron-methyl, desmedipham, thenylchlor, tebuthiuron,
tepraloxydim, trifluralin, nicosulfuron, paraquat,
halosulfuron-methyl, bialaphos, bispyribac sodium salt, bifenox,
pyrazoxyfen, pyrazosulfuron-ethyl, pyrazolate, pyraflufen-ethyl,
pyriftalid, pyributicarb, pyrimisulfan, pyriminobac-methyl,
pyroxasulfone, fenoxaprop-ethyl, fentrazamide, phenmedipham,
butachlor, butamifos, flazasulfuron, fluazifop P, pretilachlor,
bromacil, prometryn, bromobutide, bensulfuron-methyl,
benzobicyclon, benzofenap, bentazone, benthiocarb,
pendimethalin, pentoxazone, benfuresate, metamitron,
metolachlor, metribuzin, mefenacet, molinate, linuron, lenacil,
2,4 PA, ACN, CAT, DBN, DCMU, DCPA, DPA, IPC, MCPA ethyl, MCPA
thioethyl, MCPA sodium salt, MCPB, MDBA, PAC, SAP, and isoxazoline
derivatives represented by a formula [I]:

[wherein n indicates an integer of from 0 to 2; T1 and T2 each
independently represent a hydrogen atom, a halogen atom, a cyano
group, a lower alkoxycarbonyl group, or a C1-C6 alkyl group; G1
and G2 each independently represent a hydrogen atom, a C1-C6 alkyl
group, or a C1-C6 haloalkyl group; W represents a phenyl group
(substituted with from 1 to 5 and the same or different V's); V
represents a hydrogen atom, a C1-C6 alkyl group {optionally
substituted with from 1 to 3 and the same or different substituents
of a halogen atom, a C1-C6 alkoxy group, a hydroxyl group, a C1-C6
alkylthio group, a C1-C6 alkylsulf inyl group, a C1-C6 alkylsulfonyl
group, a C1-C6 alkylamino group, a C1-C6 dialkylamino group, a cyano
group or a phenoxy group (optionally substituted) }, a C1-C6 alkoxy
group (optionally substituted with from 1 to 3 and the same or
different substituents of a halogen atom, a C1-C6 alkoxy group,
a C2-C6 alkenyl group, a C2-C6 alkynyl group, a C1-C6 alkoxycarbonyl
group, a C1-C6 alkylcarbonyl group or a C3-C8 cycloalkyl group),
a C3-C8 cycloalkyloxy group, or a halogen atom].
Pyriminobac-methyl, pyrimisulfan, pyroxasulfone and
isoxazoline derivatives of formula [I] are preferred among these
herbicides.
[0021]
Specific examples of plant growth regulators include
1-naphthylacetamide, inabenfide, indole butyric acid,
uniconazole P, ethyclozate, ethephon, calcium peroxide,
cloxyfonac, chlormequat, choline, dichlorprop, gibberellin,
daminozide, decyl alcohol, paclobutrazol, prohexadione-calcium,
benzylaminopurine, forchlorfenuron, mepiquat-chloride, 4-CPA,
and the like.
[0022]
These agricultural-chemical active ingredients may be used
singly, or two or more different types thereof may be used in
combination depending on the pests and the weeds to be controlled
and the crops to be protected. The total content of the
agricultural-chemical active ingredients in the
water-dispersible particulate agricultural-chemical composition
to be produced according to the method of the invention is not
specifically defined, and may be approximately from 1 to 85 parts
by weight relative to 100 parts by weight of the composition.
[0023]
As the surfactant, nonionic surfactants, anionic
surfactants, cationic surfactants, ampholytic surfactants, and
the like may be used with no limitation. Examples of those types
of surfactants are mentioned below, to which, however, the
invention should not be limited.
[0024]
Specific examples of nonionic surfactants include
polyoxyalkylene glycols, polyoxyalkylene alkyl ethers,
polyoxyalkylene alkyl aryl ethers, polyoxyalkylene fatty acid
esters, polyoxyethylene-polyoxypropylene block polymers,
sorbitan monoalkylates, alkynols and alkynediols, as well as
alkylene oxide adducts thereof.
[0025]
Specific examples of anionic surfactants include alkali
metal salts, alkaline earth metal salts or ammonium salts of alkyl
sulfuric acids, alkyl sulfonic acids, alkyl phosphoric acids,
alkyl phosphonic acids, alkylaryl sulfonic acids, alkylaryl
phosphonic acids, polyoxyalkylene alkyl ether sulfate esters,

polyoxyalkylene alkylaryl ether sulfate esters, polyoxyalkylene
alkyl ether phosphate esters, polyoxyalkylene alkylaryl ether
phosphate esters, polycarboxylic acid-type polymers, lignin
sulfonic acids, aryl sulfonic acids, aryl sulfonic acid-formalin
condensates, alkylaryl sulfonic acid-formalin condensates, and
the like. Salts of alkyl sulfuric acids, alkylaryl sulfonic acids,
polycarboxylic acids, lignin sulfonic acids, aryl sulfonic acids,
or arylsulfonic acid-formalin condensates are preferred among
these anionic surfactants.
[0026]
Specific examples of cationic surfactants include
hydrochlorides, sulfates or carboxylates of alkylamines,
polyalkylamines, alkanolamines, polyalkanolamines,
polyalkylenepolyamines, alkylpyridines, alkylmorpholines,
alkylhydrazines, and the like.
[0027]
These surfactants may be used singly, or two or more
different types thereof may be used in combination. The total
content of the surfactants in the water-dispersible particulate
agricultural-chemical composition to be produced according to the
method of the invention is not specifically defined, and may be
approximately from 2 to 30 parts by weight relative to 100 parts
by weight of the composition.
[0028]
Other ingredients that may be optionally added to the
above-mentioned agricultural-chemical active ingredient,
surfactant and water include those that may be used in ordinary
water-dispersible agricultural-chemical composition. For
example, formulation additives such as water-soluble fine powder,
mineral fine powder, oil-absorbing fine powder, binder, grinding
aid, defoaming agent and the like may be optionally incorporated.
The water-soluble fine powder includes lactose, water-soluble
starch, urea, alkali metal salts or ammonium salts of organic acids
or inorganic acids, and the like. The mineral fine powder includes
diatomaceous earth, clay, calcium carbonate, and the like. The
oil-absorbing fine powder includes white carbon, diatomaceous
earth, microcrystalline cellulose, and the like. The binder
includes polyvinyl alcohol, carboxymethyl cellulose,
hydroxypropyl cellulose, and the like. The grinding aid includes
white carbon, silica sand, pumice, and the like. The defoaming
agent is not specifically defined, and may include silicone-based
surfactants, free long-chain fatty acids or alkali metal salts
thereof, and the like.
[0029]
The mixture kneaded in the above-mentioned step is-then
extruded through a screen having pores from 600 to 2,000 µm in
diameter to form granules in the next step (b). The pore size
of the screen is preferably from 600 to 1,800 µm, more preferably
from 600 to 1,500 µm. In cases where the pore size of the screen
is smaller than the range, not only does the yield per unit time
in extrusion granulation extremely decline but the pressure in
passing through the screen increases, leading to increased
frequency of screen breakage. On the other hand, when the pore
size is larger than the range, the granulation yield per unit time
could be large but the efficiency may be undermined because more
time is required for drying and the production yield in the step
(d) may be decline with increase in unintended fine powder in
grinding. The pore size of the screen is preferably from 0.6 to
3 times, more preferably from 0.8 to 2 times the larger opening
diameter of the meshes for use in sieving in the step (e).
[0030]
Any granulator can be used for extrusion granulation as long
as the machine is equipped for granulation, and its shape is not
specifically defined. Specific examples of the granulator
include a horizontal extrusion-type screw-extrusion granulator,
a disc die-type roll-extrusion granulator, a basket-type
blade-extrusion granulator, and the like.
[0031]
The granules formed as above are then dried in the step (c) .
Using a drier such as a fluidized bed drier or the like, the granules
are dried at a hot air temperature of from 50 to 100°C or so for
10 to 20 minutes or so. In the operation, the intralayer
temperature in the granules rises to the same level as that of
the hot air temperature and the water content thereof decreases
generally to 0.5 to 3% by mass. When not dried, the granules may
be again kneaded together by the rotational movement of the
pulverizer in the next step (d) and therefore the granules could
not be pulverized.
[0032]
The granules obtained in the above-mentioned step are in
the form of columns having a constant size, having each of the
ingredients uniformly dispersed therein, and are in a consolidated
state (a strongly-compacted state having a uniform density).
[0033]
The granules are then subjected to the step (d) . In the step,
two toothed rolls with irregularities formed on the surface are
arranged in parallel to each other with a predetermined distance,
and these toothed rolls are rotated. Then the dried granules are
led to pass through the rotating rolls for pulverization. Through
this step, the pulverized particles comprising a lot of granules
of a desired particle size can be obtained to enable efficient
production of the water-dispersible particulate
agricultural-chemical composition having a desired particle size
range. In this step, preferably, the toothed rolls are arranged
in parallel to the ground and the dried granules are thrown from
above into the toothed rolls.
[0034]
The toothed rolls for use in this step each have
irregularities formed on the roll surface. In general, the
diameter of the roll is from 50 mm to 300 mm and the length thereof
is from 20 mm to 1,500 mm. The shape of the irregularities of
the toothed rolls is not specifically defined. Preferably, the
cross section of the irregularities has a profile of continuous
triangular mounds. The shape of the triangles is not also
specifically defined. Preferably, the height and the width (base)
of the triangle fall within a range of from 0.3 mm to 10 mm and
more preferably, the height and the width are the same. Further,
the distance between the rolls is not specifically defined, and
in general, it may be from 0.05 mm to 1.5 mm. The size of the
pulverized particles can be controlled by changing the shape of
the teeth of the rolls and the distance between the rolls. In
general, when the height and the width of the triangles of the
teeth are narrower, and when the distance between the rolls is
narrower, the pulverized particles may be smaller. The apparatus
for such pulverizing may be a frame-type pulverizing apparatus.
[0035]
In the present invention, the particles pulverized as in
the above may be further pulverized by using two or more of the
above-mentioned pair of two toothed rolls in combination. In this
case, preferably, the shape of the teeth of the rolls and the
distance between the rolls are so configured that the latter
pulverizing could give particles having a smaller particle size
than the first pulverizing. A combination of these toothed rolls

comprises, for example, rolls with triangle teeth having a height
and a width of 1 mm each, arranged at the distance of 0.27 mm for
the first pulverization; and rolls with triangle teeth having a
height and a width of 0.6 mm each, arranged at the distance of
0.25 mm for the latter pulverization.
[0036]
The particles pulverized as in the above are then sieved
in the step (e). The sieving is conducted to obtain the
water-dispersible particulate agricultural-chemical composition
having a particle size within a range of from 50 to 1,000 µm,
preferably from 100 to 850 µm, more preferably from 250 to 700
µm. Concretely, the sieving may be attained by the use of two types
of meshes each having an opening diameter within a range of from
50 to 1,000 µm. More concretely, the pulverized particles are
first sieved through the mesh having the larger opening diameter
of the two types of meshes each having an opening diameter within
a range of from 50 to 1,000 µm, then the particles having passed
through the sieve are further sieved through the mesh having the
smaller opening diameter, and those having remained on the mesh
are collected. For example, the water-dispersible particulate
agricultural-chemical composition having a particle size of from
250 to 600 µm can be obtained by first sieving the pulverized
particles through a mesh having an opening diameter of 600 µm,
then further sieving those having passed through it, through a
mesh having an opening diameter of 250 µm, and collecting those
having remained on the mesh. The machine for the sieving includes
a rotary shifter, a shaking sieve, and the like.
[0037]
According to the steps (a) to (e) described above, the
water-dispersible particulate agricultural-chemical composition
having a particle size of from 50 to 1,000 µm can be produced
efficiently.
[0038]
The water-dispersible particulate agricultural-chemical
composition thus produced is excellent in
disintegrability/dispersibility in water.
[0039]
In the present invention, the reason why the
water-dispersible particulate agricultural-chemical composition
having a particle size of from 50 to 1,000 µm can be produced
efficiently is because a uniform kneaded mixture of ingredients
such as an agricultural-chemical active ingredient and others is
produced in the step (a), and then granules having a shape of
columns with a constant size in a consolidated state are produced
in the step (b) . In addition, when the granules dried in the step
(c) are led to pass through two toothed rolls used in the
latter-stage of the step (d) , almost all the granules are cut from
the side of each column to be pulverized since the granules have
a shape of columns with a constant size; and while they are
pulverized, the consolidated structure of the granules prevents
generation of large amount of unintended fine powder, with the
result that the water-dispersible particulate
agricultural-chemical composition having a desired particle size
can be obtained efficiently in a high production yield.
[0040]
On the other hand, when the ingredients of the granules to
be processed in the step (d) are not homogeneous, when the density
of the granules is not uniform, or when the granules are amorphous,
then the particles pulverized in the step (d) have a broad particle
size distribution, and in particular, unintended fine particles
are formed much, resulting in a low production yield.
Examples
[0041]
The present invention will be described in more detail with
reference to Examples and Comparative Examples; however, the
invention should not be limited to these Examples. In the
following Examples, the term "part" means part by weight.
[0042]
Example 1
40 parts of pyribencarb, 4 parts of sodium alkyl sulfate,
5 parts of sodium lignin sulfonate, and 51 parts of calcium
carbonate were mixed, and ground with a high-speed
airflow-assisted grinder so that the mean particle size of the
ingredients could be 7 µm. Next, 15 parts of water was added to
100 parts of the ground particles, and further kneaded. At the
time when the added water had penetrated into the whole mixture,
the kneaded mixture was granulated with a horizontal
extrusion-type screw-extrusion granulator. The screen used in
extrusion granulation had pores 800 µm in diameter. The obtained
granules were dried in a fluidized bed drier at a hot air
temperature of 55°C for about 10 minutes until the intralayer
temperature could reach 55°C. Subsequently, using a frame-type
pulverizing apparatus having two toothed rolls arranged in
parallel to the ground and having a slot above the rolls, the dried
granules were led to pass through the rotating rolls in this
apparatus and pulverized. The height and the width of the
triangles of the teeth were both 0.6 mm and the distance between
the rolls was 0.25 mm. The pulverized particles were then sieved
through a mesh having an opening diameter of 500 µm, and those
having passed through the mesh were further sieved through a mesh
having an opening diameter of 250 µm; and those having remained
on the mesh were collected to obtain a water-dispersible
particulate agricultural-chemical composition having a particle
size within a range of from 250 to 500 µm.
[0043]
Example 2
40 parts of pyribencarb, 4 parts of sodium alkyl sulfate,
5 parts of sodium lignin sulfonate, and 51 parts of calcium
carbonate were mixed, and ground with a high-speed
airflow-assisted grinder so that the mean particle size of the
ingredients could be 7 µm. Next, 15 parts of water was added to
100 parts of the ground particles, and further kneaded. At the
time when the added water had penetrated into the whole mixture,
the kneaded mixture was granulated with a horizontal
extrusion-type screw-extrusion granulator. The screen used in
extrusion granulation had pores 1,800 fim in diameter. The
obtained granules were dried in a fluidized bed drier at a hot
air temperature of 55°C for about 20 minutes until the intralayer
temperature could reach 55°C. Subsequently, using a frame-type
pulverizing apparatus having two pairs of toothed rolls arranged
one above the other in parallel to the ground and having a slot
above the rolls, the dried granules were led to pass through the
rotating rolls in this apparatus and pulverized. The height and
the width of the triangles of the teeth were both 1.5 mm and the
distance between the rolls was 0.8 mm in the upper pair of rolls;
and the height and the width were both 0.6 mm and the distance
was 0.25 mm in the lower pair of rolls. The pulverized particles
were then sieved through a mesh having an opening diameter of 500
µm, and those having passed through the mesh were further sieved
through a mesh having an opening diameter of 250 µm; and those
having remained on the mesh were collected to obtain a
water-dispersible particulate agricultural-chemical composition

having a particle size within a range of from 250 to 500 µm.
[0044]
Example 3
40 parts of mepanipyrim, 2 parts of sodium alkyl sulfate,
8 parts of sodium lignin sulfonate, and 50 parts of clay were mixed,
and ground with a high-speed airflow-assisted grinder so that the
mean particle size of the ingredients could be 5 µm. Next, 18 parts
of water was added to 100 parts of the ground particles, and further
kneaded. At the time when the added water had penetrated into
the whole mixture, the kneaded mixture was granulated with a
horizontal extrusion-type screw-extrusion granulator. The
screen used in extrusion granulation had pores 1, 000 µm in diameter.
The obtained granules were dried in a fluidized bed drier at a
hot air temperature of 55°C for about 10 minutes until the
intralayer temperature could reach 55°C. Subsequently, using a
frame-type pulverizing apparatus having two toothed rolls
arranged in parallel to the ground and having a slot above the
rolls, the dried granules were led to pass through the rotating
rolls in this apparatus and pulverized. The height and the width
of the triangles of the teeth were both 0.6 mm and the distance
between the rolls was 0.25 mm. The pulverized particles were then
sieved through a mesh having an opening diameter of 600 µm, and
those having passed through the mesh were further sieved through
a mesh having an opening diameter of 150 µm; and those having
remained on the mesh were collected to obtain a water-dispersible
particulate agricultural-chemical composition having a particle
size within a range of from 150 to 600 µm.
[0045]
Example 4
10 parts of pyribencarb, 30 parts of a mixture (1/1 by weight)
of iminoctadine albesilate and white carbon, 4 parts of sodium
alkyl sulfate, 15 parts of maleic anhydride-isobutylene
copolycondensate, and 41 parts of calcium carbonate were mixed,
and ground with a high-speed airflow-assisted grinder so that the
mean particle size of the ingredients could be 9 µm. Next, 20 parts
of water was added to 100 parts of the ground particles, and further
kneaded. At the time when the added water had penetrated into
the whole mixture, the kneaded mixture was granulated with a
horizontal extrusion-type screw-extrusion granulator. The
screen used in extrusion granulation had pores 600 µm in diameter.
The obtained granules were dried in a fluidized bed drier at a
hot air temperature of 55°C for about 10 minutes until the
intralayer temperature could reach 55°C. Subsequently, using a
frame-type pulverizing apparatus having two toothed rolls
arranged in parallel to the ground and having a slot above the
rolls, the dried granules were led to pass through the rotating
rolls in this apparatus and pulverized. The height and the width
of the triangles of the teeth were both 0.6 mm and the distance
between the rolls was 0.25 mm. The pulverized particles were then
sieved through a mesh having an opening diameter of 600 µm, and
those having passed through the mesh were further sieved through
a mesh having an opening diameter of 150 µm; and those having
remained on the mesh were collected to obtain a water-dispersible
particulate agricultural-chemical composition having a particle
size within a range of from 150 to 600 µm.
[0046]
Example 5
50 parts of pyriminobac-methyl, 20 parts of sodium
alkylnaphthalene sulfonate-formalin condensate, 1 part of
polyoxyalkylene alkylaryl ether, and 29 parts of calcined
diatomaceous earth were mixed, and ground with a high-speed
airflow-assisted grinder so that the mean particle size of the
ingredients could be 4 µm. Next, 15 parts of water was added to
100 parts of the ground particles, and further kneaded. At the
time when the added water had penetrated into the whole mixture,
the kneaded mixture was granulated with a horizontal
extrusion-type screw-extrusion granulator. The screen used in
extrusion granulation had pores 700 µm in diameter. The obtained
granules were dried in a fluidized bed drier at a hot air
temperature of 55°C for about 10 minutes until the intralayer
temperature could reach 55°C. Subsequently, using a frame-type
pulverizing apparatus having two toothed rolls arranged in
parallel to the ground and having a slot above the rolls, the dried
granules were led to pass through the rotating rolls in this
apparatus and pulverized. The height and the width of the
triangles of the teeth were both 0.6 mm and the distance between
the rolls was 0.25 mm. The pulverized particles were then sieved
through a mesh having an opening diameter of 500 µm, and those
having passed through the mesh were further sieved through a mesh
having an opening diameter of 250 µm; and those having remained
on the mesh were collected to obtain a water-dispersible
particulate agricultural-chemical composition having a particle
size within a range of from 250 to 500 µm.
[0047]
Example 6
85 parts of pyroxasulfone, 3 parts of sodium
alkylnaphthalene sulfonate-formalin condensate, 8 parts of sodium
lignin sulfonate, 1 part of polyoxyalkylene aryl ether, and 3 parts
of calcined diatomaceous earth were mixed, and ground with a
high-speed airflow-assisted grinder so that the mean particle size
of the ingredients could be 5 µm. Next, 15 parts of water was added
to 100 parts of the ground particles, and further kneaded. At
the time when the added water had penetrated into the whole mixture,
the kneaded mixture was granulated with a horizontal
extrusion-type screw-extrusion granulator. The screen used in
extrusion granulation had pores 800 µm in diameter. The obtained
granules were dried in a fluidized bed drier at a hot air
temperature of 55°C for about 10 minutes until the intralayer
temperature could reach 55°C. Subsequently, using a frame-type
pulverizing apparatus having two toothed rolls arranged in
parallel to the ground and having a slot above the rolls, the dried
granules were led to pass through the rotating rolls in this
apparatus and pulverized. The height and the width of the
triangles of the teeth were both 0.6 mm and the distance between
the rolls was 0.25 mm. The pulverized particles were then sieved
through a mesh having an opening diameter of 500 µm, and those
having passed through the mesh were further sieved through a mesh
having an opening diameter of 250 µm; and those having remained
on the mesh were collected to obtain a water-dispersible
particulate agricultural-chemical composition having a particle
size within a range of from 250 to 500 µm.
[0048]
Comparative Example 1
40 parts of pyribencarb, 4 parts of sodium alkyl sulfate,
5 parts of sodium lignin sulfonate, and 51 parts of calcium
carbonate were mixed, and ground with a high-speed
airflow-assisted grinder so that the mean particle size of the
ingredients could be 7 µm. Next, 15 parts of water was added to
100 parts of the ground particles, and further kneaded. At the
time when the added water had penetrated into the whole mixture,
the kneaded mixture was granulated with a horizontal
extrusion-type screw-extrusion granulator. The screen used in
extrusion granulation had pore 300 µm in diameter. However, since
the screen was broken and the granulation could not be attained,
the intended water-dispersible particulate
agricultural-chemical composition could not be obtained.
[0049]
Comparative Example 2
40 parts of pyribencarb, 4 parts of sodium alkyl sulfate,
5 parts of sodium lignin sulfonate, and 51 parts of calcium
carbonate were mixed, and ground with a high-speed
airflow-assisted grinder so that the mean particle size of the
ingredients could be 7 µm. Next, 15 parts of water was added to
100 parts of the ground particles, and further kneaded. At the
time when the added water had penetrated into the whole mixture,
the kneaded mixture was granulated with a horizontal
extrusion-type screw-extrusion granulator. The screen used in
extrusion granulation had pores 3,000 µm in diameter. The
obtained granules were dried in a fluidized bed drier at a hot
air temperature of 55°C for about 20 minutes until the intralayer
temperature could reach 55°C. Subsequently, using a frame-type
pulverizing apparatus having three pairs of toothed rolls arranged
in upper, middle and lower three stages so as to be in parallel
to the ground and having a slot above the rolls, the dried granules
were led to pass through the rotating rolls in this apparatus and
pulverized. The height and the width of the triangles of the teeth
were both 2.0 mm and the distance between the rolls was 1.5 mm
in the upper pair of rolls; the height and the width were both
1.5 mm and the distance was 0.8 mm in the middle pair of rolls;
and the height and the width were both 0.6 mm and the distance
was 0.25 mm in the lower pair of rolls. The pulverized particles
were then sieved through a mesh having an opening diameter of 500
µm, and those having passed through the mesh were further sieved
through a mesh having an opening diameter of 250 µm; and those
having remained on the mesh were collected to obtain a
water-dispersible particulate agricultural-chemical composition
having a particle size within a range of from 250 to 500 µm.
[0050]
Comparative Example 3
40 parts of pyribencarb, 4 parts of sodium alkyl sulfate,
5 parts of sodium lignin sulfonate, and 51 parts of calcium
carbonate were mixed, and ground with a high-speed
airflow-assisted grinder so that the mean particle size of the
ingredients could be 7 urn. Next, with spraying 15 parts of water
onto 100 parts of the ground particles, granules having a particle
size of from 100 to 5,000 µm or so were obtained by means of a
stirring granulator. The obtained granules were dried in a
fluidized bed drier at a hot air temperature of 55°C for about
10 minutes until the intralayer temperature could reach 55°C.
Subsequently, using a frame-type pulverizing apparatus having two
toothed rolls arranged in parallel to the ground and having a slot
above the rolls, the dried granules were led to pass through the
rotating rolls in this apparatus and pulverized. The height and
the width of the triangles of the teeth were both 0.6 mm and the
distance between the rolls was 0.25 mm. The pulverized particles
were then sieved through a mesh having an opening diameter of 500
µm, and those having passed through the mesh were further sieved
through a mesh having an opening diameter of 250 µm; and those
having remained on the mesh were collected to obtain a
water-dispersible particulate agricultural-chemical composition
having a particle size within a range of from 250 to 500 µm.
[0051]
Comparative Example 4
40 parts of pyribencarb, 4 parts of sodium alkyl sulfate,
5 parts of sodium lignin sulfonate, and 51 parts of calcium
carbonate were mixed, and ground with a high-speed
airflow-assisted grinder so that the mean particle size of the
ingredients could be 7 µm. Next, with spraying 15 parts of water
onto 100 parts of the ground particles, granules having a particle
size of from 100 to 5,000 µm or so were obtained by means of a
stirring granulator. Using a frame-type pulverizing apparatus
having two toothed rolls arranged in parallel to the ground and
having a slot above the rolls, the obtained granules were, without
being dried, led to pass through the rotating rolls in this
apparatus so as to be pulverized. However, since the granules
were again kneaded together between the rolls and could not be
pulverized, the intended water-dispersible particulate
agricultural-chemical composition could not be obtained. The
height and the width of the triangles of the teeth were both 0.6
mm and the distance between the rolls was 0.25 mm.
[0052]
Comparative Example 5
10 parts of pyribencarb, 30 parts of a mixture (1/1 by weight)
of iminoctadine albesilate and white carbon, 4 parts of sodium
alkyl sulfate, 15 parts of sodium

naphthalenesulfonate-formaldehyde condensate, and 41 parts of
calcium carbonate were mixed, and ground with a high-speed
airflow-assisted grinder so that the mean particle size of the
ingredients could be 9 µm. Next, 20 parts of water was added to
100 parts of the ground particles, and further kneaded. At the
time when the added water had penetrated into the whole mixture,
the kneaded mixture was granulated with a horizontal
extrusion-type screw-extrusion granulator. The screen used in
extrusion granulation had pores 600 µm in diameter. The obtained
granules were dried in a fluidized bed drier at a hot air
temperature of 55°C for about 10 minutes until the intralayer
temperature could reach 55°C. The dried granules were sieved
through a mesh having an opening diameter of 600 µm, and those
having passed through the mesh were further sieved through a mesh
having an opening diameter of 150 µm; and those having remained
on the mesh were collected to obtain a water-dispersible
particulate agricultural-chemical composition having a particle
size within a range of from 150 to 600 µm.
[0053]
Test Example 1
Disintegration Test:
0.3077 g of calcium carbonate and 0.092 g of magnesium oxide
were dissolved in a small amount of diluted hydrochloric acid,
then heated and boiled on a sand bath to remove hydrochloric acid.
Distilled water was added to the remaining solution to make 10
liters in total. Subsequently, 100 ml of the obtained solution
was put into a 100-ml stoppered measuring cylinder, and kept at
20°C in a temperature-controlled room. 100 mg of the
water-dispersible particulate agricultural-chemical composition
produced in Examples 1 to 6 and Comparative Example 5 was put into
the measuring cylinder, statically left as it was for 30 seconds,
and then the measuring cylinder was turned upside down repeatedly
in a ratio of once a second, whereupon the turning-down frequency
needed for disintegrating the whole water-dispersible particulate
agricultural-chemical composition was counted. The results are
shown in Table 1.
[0054]
Table 1
[0055]
From Table 1, it is known that the water-dispersible
particulate agricultural-chemical compositions of the present
invention have high disintegrability in water and are excellent
in dispersibility.
[0056]
Test Example 2
Evaluation of Production Efficiency:
Using starting materials of 10 kg in total,
water-dispersible particulate agricultural-chemical
compositions were produced according to the above-mentioned
Examples and Comparative Examples, and the weight of the
finally-obtained water-dispersible particulate
agricultural-chemical composition was measured. The results are
shown in Table 2.
[0057]
Table 2
[0058]
From Table 2, it is known that the method for producing a
water-dispersible particulate agricultural-chemical composition
of the present invention provides a high production yield and is
excellent in production efficiency.
Industrial Applicability
[0059]
According to the method for producing a water-dispersible
particulate agricultural-chemical composition of the present
invention, a loss of starting materials in the production process
is small, a load to the machine for the production is low, and
the production yield of the water-dispersible particulate
agricultural-chemical composition having a desired particle size
is high as compared with conventional production methods.
[0060]
Therefore, the method of the present invention can be
advantageously used in producing a water-dispersible particulate
agricultural-chemical composition for use in controlling pests
and weeds for agricultural/horticultural crops.
CLAIMS
1. A method for producing a water-dispersible
particulate agricultural-chemical composition having a particle
size within a range of from 50 to 1,000 µm, the method comprising
the following steps (a) to (e):
(a) a step of kneading an agricultural-chemical active
ingredient, a surfactant and water,
(b) a step of extruding the kneaded mixture through a screen
having pores from 600 to 2,000 µm in diameter to form granules,
(c) a step of drying the granules,
(d) a step of rotating two toothed rolls with irregularities
on the surface arranged in parallel to each other, and leading
the dried granules to pass through the toothed rolls thereby
pulverizing the granules, and
(e) a step of sieving the pulverized particles.
2. The method for producing a water-dispersible
particulate agricultural-chemical composition according to claim
1, wherein in the step (e), the pulverized particles are sieved
through two types of meshes each having an opening diameter within
a range of from 50 to 1,000 µm.
3. The method for producing a water-dispersible
particulate agricultural-chemical composition according to claim
2, wherein in the step (e), the pulverized particles are first
sieved through the mesh having the larger opening diameter of the
two types of meshes each having an opening diameter within a range
of from 50 to 1,000 µm, then those having passed through the sieve
are further sieved through the mesh having the smaller opening
diameter, and those having remained on the mesh are collected.

A process for efficiently producing a water-dispersible
particulate agricultural-chemical composition having improved
disintegrability/dispersibility in water, the composition having
a particular size in the range of 50 - 1,000 µm. The process is
characterized by comprising the following steps (a) to (e) : (a)
a step of kneading an agricultural-chemical active ingredient,
a surfactant, and water; (b) a step of extruding the resultant
mixture through a screen having pores 600 - 2,000 µm in diameter
to form granules; (c) a step of drying the granules; (d) a step
of rotating two toothed rolls with irregularities on the surface
arranged in parallel to each other, and leading the dried granules
to pass between the toothed rolls thereby pulverizing the
granules; and (e) a step of sieving the pulverized granules.

Documents:

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Patent Number

278229

Indian Patent Application Number

2394/KOLNP/2011

PG Journal Number

53/2016

Publication Date

23-Dec-2016

Grant Date

19-Dec-2016

Date of Filing

08-Jun-2011

Name of Patentee

KUMIAI CHEMICAL INDUSTRY CO., LTD.

Applicant Address

4-26, IKENOHATA 1-CHOME, TAITO-KU, TOKYO 1108782 JAPAN

Inventors:

#	Inventor's Name	Inventor's Address
1	FUJITA, SHIGEKI	C/O KUMIAI CHEMICAL INDUSTRY CO., LTD., 4-26, IKENOHATA 1-CHOME, TAITO-KU, TOKYO 1108782 JAPAN
2	KURITA, KAZUNORI	C/O KUMIAI CHEMICAL INDUSTRY CO., LTD., 4-26, IKENOHATA 1-CHOME, TAITO-KU, TOKYO 1108782 JAPAN

PCT International Classification Number

A01N 25/12

PCT International Application Number

PCT/JP2009/068793

PCT International Filing date

2009-11-04

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	2008-306159	2008-12-01	Japan