JP2012017266A - Mixed microcapsule agrochemical composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mixed microcapsule composition capable of satisfying both of initial effect and carry-over effect required for simultaneous control of a soil pest and an eelworm by the microcapsule preparation.SOLUTION: The mixed microcapsule agrochemical composition includes microcapsules (A) including a nematicidal active ingredient of the first agrochemical, and microcapsules (B) including a soil pest-controlling active ingredient of the second agrochemical, and is regulated so that the microcapsules (A) may have a volume median diameter within a range of 1-20 μm, and the microcapsules (B) may have a volume median diameter within a range of 20-100 μm.

Description

  The present invention relates to the field of agricultural chemical formulations for controlling soil pests and nematodes, and in particular to the field of microcapsule agricultural chemical formulations.

Currently, various pesticides are used in combination to simultaneously control pests such as soil pests and nematodes. Mixed use of pesticides can save labor for spraying pesticides and reduce the burden on the user. On the other hand, the interaction between agricultural chemicals may cause negative effects such as degradation of the active ingredient and reduction in efficacy, and enhancement of phytotoxicity to crops.
Patent Document 1 describes that a synergistic control effect against nematodes can be obtained by using a combination of a specific organophosphorus nematicide and an organophosphorus insecticide. However, in the combined use, there is no description about the result showing a synergistic control effect against soil pests, and there is no disclosure about the simultaneous control effect of nematodes and soil pests. In addition, it does not consider the stability in mixing the organophosphorus nematicide and the organophosphorus insecticide, and relates to a mixed preparation in which a plurality of pesticides having different physicochemical stability are mixed in a bottle is not.

  On the other hand, microcapsule formulations with microcapsules of pesticide ingredients are known to have excellent physicochemical stability and high safety to the user and the surrounding environment because the pesticide ingredients are encapsulated in a capsule membrane. ing. However, in general, microcapsule preparations are excellent in residual effect that can maintain agricultural chemical efficacy over a long period of time, but are often insufficient in initial efficacy immediately after application of agricultural chemicals. In the case of microcapsule preparations, it is difficult to set conditions for microcapsule preparations, such as controlling the dissolution of encapsulated drugs from capsule membranes and controlling the stability of microcapsules. There has been little research on expanding the spectrum of target pests.

  Patent Document 2 describes a microcapsule preparation in which two or more active ingredients are encapsulated. About the manufacturing method of the microcapsule containing the first pesticide clomazone and the second pesticide in the microcapsule, and the microcapsule suspension of the herbicide clomazone and other herbicide may be encapsulated A method for mixing suspensions is described. However, when two or more kinds of active ingredients are encapsulated in the same microcapsule, the physical properties such as water solubility and stability of each active ingredient are different, so that it becomes difficult to control elution and stabilize the preparation. In the method of mixing the encapsulated suspension, it is necessary to adjust the stability of both microcapsules. Further, it is a preparation for herbicidal purposes and is not a preparation for simultaneous control of soil pests and nematicides.

  Patent Document 3 describes a microcapsule of a pyrethroid insecticide for the purpose of initial activity, residual effect, and insecticidal spectrum expansion by mixing two types of microcapsules having different film thicknesses. Control the elution of active ingredients by setting the film thickness of two types of microcapsules to 0.001 μm to 0.01 μm on one side and 0.01 μm to 0.5 μm on the other side. To make it longer. However, controlling the elution by changing the film thickness is not preferable in terms of formulation stability because the strength of the microcapsules decreases. Moreover, there is no description using different active ingredients other than pyrethroid insecticides, and it is not a preparation intended for simultaneous control of insecticides and nematicides with two types of pesticides.

  The microcapsule preparation is an agrochemical preparation that exhibits a desired control effect by eluting the pesticidal components encapsulated in a film to the outside and sensitizing the target pests. However, pests in agriculture and horticulture are diverse, and the mechanism for eluting pesticide components from microcapsules, the optimum pesticide application rate and optimum sensitization time, and the sensitivity to drugs differ depending on each pest species. It was difficult to design a microcapsule formulation that can simultaneously control the target pests. In particular, harmful insects and nematodes that inhabit the soil have greatly different body lengths and ecology, and therefore microcapsule preparations that can simultaneously control these soil pests are not known. In other words, scarab beetle larvae, which are typical as soil pests, have a high motility with a body length of 1 to 3 cm, and are an ecology that damages the rhizomes of agricultural and horticultural crops in the soil. On the other hand, nematodes are extremely small with a body length of 1 mm or less, and are sucking organisms parasitic on agricultural and horticultural crops. Therefore, since insect larvae and nematodes are greatly different in ecology and also have different pesticide sensitivities, in order to prescribe microcapsule preparations that can control these harmful insects and nematodes at the same time, the elution mechanism of encapsulated pesticides is designed. It is important to control the dissolution rate of encapsulated pesticides and to select the encapsulated pesticides appropriately. In particular, nematodes have an extremely small body length and are highly ecologically proliferating in soil. Therefore, a high dose of nematicidal active ingredient is required for nematode control in nematode contaminated soil. Therefore, the microcapsules of nematicidal active ingredients are desired to have a characteristic that ensures rapid dissolution of the encapsulated drug, and in addition, characteristics that allow the encapsulated drug to be eluted continuously over a long period of time are desired.

JP 2007-269787 A Japanese translation of PCT publication No. 2002-523338 JP-A-10-59812

  In the agricultural and horticultural industry, nematodes and soil pests that inhabit the soil and damage agricultural and horticultural crops must be controlled. Although each method for controlling nematodes and soil pests is known, there is no known effective method that can control them simultaneously by spraying agricultural chemicals once. Furthermore, nematodes and soil pest control pesticides that can be safely sprayed by pesticide applicators are desired. In addition, there is a need for nematode and soil pest control pesticide formulations that exhibit sufficient initial control efficacy in the early stage of pesticide spraying and that can maintain their control effect over a long period of time with a single pesticide spray. However, it is not preferable from the viewpoint of the strength and stability of the microcapsules to make the microcapsule film thinner in order to obtain the initial control effect, and the residual effect cannot be maintained. The present invention aims to solve the above problems.

  That is, the present invention uses a microcapsule formulation technology, and in a microcapsule pesticide composition that ensures the safety and long-term medicinal sustainability of a pesticide sprayer, nematode and soil pests can be controlled simultaneously in a single pesticide spray. The microcapsule pesticide can satisfy both the initial effect by elution for achieving a sufficient effect on nematodes and the residual effect by sufficiently maintaining the strength and stability of the microcapsules. It is an object to provide a composition.

  As a result of diligent research to solve the above problems, the present inventors include a microcapsule having a volume median diameter of 1 to 20 μm containing a nematicidal active ingredient as a core substance, and a soil pest controlling active ingredient as a core substance. It was found that a desired effect can be achieved by preparing microcapsules each having a volume median diameter of 20 to 100 μm and mixing them to obtain a microcapsule mixed composition, thereby completing the present invention.

That is, the present invention includes (1) a microcapsule (A) containing a nematicidal active ingredient as a first pesticide and a microcapsule (B) containing a soil pest controlling active ingredient as a second pesticide. A microcapsule mixed pesticide composition, wherein the microcapsule (A) has a volume median diameter of 1 to 20 μm, and the microcapsule (B) has a volume median diameter of 20 to 100 μm Agrochemical composition,
(2) The microcapsule mixed agricultural chemical composition according to (1), wherein at least one of the first agricultural chemical and the second agricultural chemical is an organic phosphorus agent,
(3) The first agrochemical is O-ethyl-Sn-propyl (2-cyanoimino-3-ethylimidazolidin-1-yl) phosphonothiolate (generic name: imisiaphos), S, S-di- sec-butyl-O-ethyl-phosphorodithioate (generic name: kazusafos), (R, S) -S-sec-butyl-O-ethyl-2-oxo-1,3-thiazolidin-ylphosphonothioate ( Any one or more organophosphorus nematicidal active ingredients selected from the group consisting of: general name: Phostiazate, wherein the second pesticide is O, O-diethyl-O-2-isopropyl-6- Methylpyrimidin-4-yl-phosphorothioate (generic name: diazinon), O, O-dimethyl-O-4-methylthio-m-toluyl-phosphorothioate (generic name: fenthion), Said (1)-which is any one or more organophosphorus soil pest control agents selected from the group consisting of O, O-dimethyl-O-4-nitro-m-toluyl-phosphorothioate (generic name: fenitrothion) The microcapsule mixed agricultural chemical composition according to any one of (2),
(4) The microcapsule mixed pesticide composition according to any one of (1) to (3), wherein an active ingredient ratio of the first pesticide and the second pesticide is 1: 5 to 5: 1. ,
(5) The microcapsule mixed agricultural chemical composition according to any one of (1) to (4), wherein a glycol is added,
(6) Diluting the microcapsule mixed agricultural chemical composition according to any one of (1) to (5) 10 to 200 times with respect to the total amount of active ingredients, Control method,
(7) The present invention relates to the method for controlling soil pests according to (6), wherein soil nematodes and soil pests are simultaneously controlled.

  Although the microcapsule mixed agricultural chemical composition of the present invention is a mixed composition of nematicidal active ingredients and soil pest control active ingredients having different physicochemical stability, it is excellent in stability as a mixed preparation. In the microcapsule mixed agricultural chemical composition, by mixing two microcapsule preparations, elution of the nematicidal active ingredient is promoted while maintaining the strength of the film from the microcapsule (A). It can satisfy both the initial spraying effect, especially the nematicidal effect, and the long-term control effect, which has been a problem with microcapsule preparations, and can simultaneously control nematodes and soil pests with a single spraying. To. Furthermore, since the agrochemical active ingredient is encapsulated in the microcapsule and the sprayer is not directly exposed to the high concentration of the agrochemical active ingredient, safety is also ensured.

  In the present invention, the nematicidal active ingredient is applied as the first pesticide. The nematicidal active ingredient used is not particularly limited. For example, specific examples of applicable nematicides include organophosphorus nematicides such as phosthiazet, imisiaphos, kazusafos, DD, chlorpicrin, Examples thereof include soil fumigants such as methyl isothiocyanate oil, carbum nematicides such as NCS and Kilper, and carbamate nematicides such as oxamyl. Of these, organophosphorus nematicides are particularly preferred in view of the nematicidal activity efficacy in microcapsule formulation, and imisiaphos, kazusafos, and phosphothiazate are particularly preferred. If there is no problem with mixing stability, two or more of these may be used.

  In the present invention, a soil pest control active ingredient is applied as the second agricultural chemical. The soil pest control active ingredient used is not particularly limited.For example, specific examples of applicable soil pest control agents include diazinon, fenitrothion, fenthion, calvinphos, chlorpyrifos, chlorpyrifosmethyl, cyanophenphos, cyanophos, dichlorvos, malathion, Organophosphorus insecticides such as nared, pyrimifosmethyl, prothiophos, pyridafenthion, salicione, tetrachlorovinphos, trichlorfone, promofos, propetanephos, BPMC, carbaryl, ethiophene curve, propoxer, carbamate insecticides such as XMC, cypermethrin, cyphenothrin , Deltamethrin, fenpropathrin, fenvalerate, cadreslin, permethrin, phenothrin, propulserin, resmesulin, al Amesulin, tralomethrin, fluthyrine, biphenothrin, cyhalothrin, flumethrin, fenclusulin, cycloprotorin, fulvalinate, pyrethroid insecticides such as etofenprox, silaneophan, imidacloprid, clothianidin, thiamethoxam, acetamiprid, thiacloprid, tenapiramide And neonicotinoid insecticides such as dinotefuran, other metaaldehydes, hexaflumuron, hydramethylnon, sulfuramide and the like. Among these, considering the insecticidal activity efficacy in microcapsule formulation, organophosphorus insecticides are preferable, and diazinon, fenitrothion, and fenthion are particularly preferable. If there is no problem with mixing stability, two or more of these may be used.

In the present invention, the microcapsules enclosing the nematicidal active ingredient as the first pesticide and the soil pest controlling active ingredient as the second pesticide are not particularly limited, and are microcapsules prepared by a known technique. Can be used. A preferred microcapsule preparation method is a chemical preparation method, and particularly preferred are the interfacial polymerization method and the InSitu method, which can be easily manufactured, can be encapsulated in a short time, and can be easily controlled in particle size. .
The interfacial polymerization method is, for example, a method of interfacially polymerizing a polybasic acid halide and a polyol to form a film made of polyester, a method of interfacially polymerizing a polybasic acid halide and a polyamine to form a film made of polyamide, A method of forming a film made of polyurethane by interfacial polymerization of polyisocyanate and polyol, a method of forming a film made of polyurea by interfacial polymerization of polyisocyanate and polyamine, and the like are used.
In the In Situ method, for example, a method of forming a film made of a polystyrene copolymer by copolymerizing styrene and divinylbenzene, or a film made of a polymethacrylate copolymer by copolymerizing methyl methacrylate and n-butyl methacrylate. For example, a method of forming a film made of a melamine resin by copolymerizing melamine and formaldehyde may be used.
In the present invention, which of the above-described methods is used to prepare the microcapsules can be appropriately selected depending on the kind of active ingredient, the purpose of use, or the application, but the interfacial polymerization method is particularly preferably used. Next, the manufacturing method of the microcapsule which includes such an active ingredient by the interfacial polymerization method will be described in more detail.

In the interfacial polymerization method, an oil phase component including an agrochemical active ingredient and an oil-soluble film forming component is first prepared.
Examples of the oil-soluble film forming component include polyisocyanate, polycarboxylic acid halide, polysulfonic acid halide, and the like.
Examples of the polyisocyanate include aromatic polyisocyanates such as diphenylmethane diisocyanate and toluene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, and hydrogenated diphenylmethane diisocyanate. Examples include araliphatic polyisocyanates such as methylene polyphenyl isocyanate, xylylene diisocyanate, and tetramethyl xylylene diisocyanate. In addition, derivatives of these polyisocyanates, such as dimers, trimers, biurets, allophanates, carbodiimides, uretdiones, oxadiazine triones, and modified products of these polyisocyanates, such as low molecular weight polyols and polyethers such as trimethylolpropane. A polyol-modified polyisocyanate obtained by reacting a high molecular weight polyol such as a polyol in advance may also be used.
Examples of the polycarboxylic acid halide include sebacic acid dihalide, adipic acid dihalide, azelaic acid dihalide, terephthalic acid dihalide, and trimesic acid dihalide. As the halide, chloride is widely used and is preferred.
Examples of the polysulfonic acid halide include benzenesulfonyl dihalide, and benzenesulfonyl chloride is more preferable.
These oil-soluble film-forming components may be used alone or in combination of two or more. Preferably, polyisocyanate is mentioned, More preferably, hexamethylene diisocyanate is mentioned.

The oil phase component can be prepared by blending these when the oil-soluble film-forming component is a liquid at room temperature and the agrochemical active ingredient can be dissolved or dispersed in the oil-soluble film-forming component. Alternatively, for example, it can be prepared by blending an agrochemical active ingredient and an oil-soluble film-forming ingredient, if necessary, using an organic solvent.
The organic solvent is not particularly limited as long as it can dissolve or disperse the agricultural chemical active ingredient, and can be appropriately selected according to the type of the active ingredient. Examples of such organic solvents include aliphatic hydrocarbons such as hexane, cyclohexane, octane, and decane, aromatic hydrocarbons such as benzene, toluene, and xylene, esters such as ethyl acetate and butyl acetate, and tetrachloride. Examples of halogenated hydrocarbons such as carbon, chloroform, dichloromethane, 1,1,1-trichloroethane, chlorobenzene, and dichlorobenzene, and high-boiling aromatic organic solvents include alkylbenzenes, alkylnaphthalenes, alkylphenols, More specific examples include various commercially available organic solvents obtained from petroleum fractions, such as Certrex 48 (high-boiling aromatic solvent, distillation range 254 to 386 ° C., Mobil Petroleum Co., Ltd. ), Alkene L (alkylbenzene, distillation range 28) 5 to 309 ° C., Nippon Petrochemical Co., Ltd.), Solvesso 150 (alkyl naphthalene, distillation range 179 to 213 ° C., Exxon Chemical Co., Ltd.), Solvesso 200 (alkyl naphthalene, distillation range 226 to 286 ° C., Exxon Chemical) KMC-113 (diisopropyl naphthalene, boiling point 300 ° C., Kureha Chemical Industry Co., Ltd.), SAS296 (phenylxylylethane, distillation range 290-305 ° C., Nippon Petrochemical Co., Ltd.), etc. Can be mentioned. These organic solvents may be used alone or in combination of two or more.
The blending ratio of the agricultural chemical active ingredient and the organic solvent is, for example, 5 to 60 parts by weight, preferably 10 to 50 parts by weight of the agricultural chemical active ingredient with respect to 100 parts by weight of the total of the agricultural chemical active ingredient and the organic solvent. The organic solvent is 40 to 95 parts by weight, preferably 50 to 90 parts by weight.

The blending ratio of the oil-soluble film forming component can be blended in the range of 0.1 to 99.9 parts by weight with respect to 100 parts by weight of the oil phase component, but 1 to 90 parts by weight, and further 10 to 50 parts by weight. It is preferable to mix in the range of parts by weight. When the blending ratio of the oil-soluble film forming component is increased, the resulting microcapsule film may be too thick. On the other hand, when the blending ratio of the oil-soluble film forming component is reduced, it may be impossible to form a microcapsule film.
And an oil phase component can be prepared by mix | blending an agrochemical active ingredient and an oil-soluble film formation component using an organic solvent if needed, and stirring and mixing.

In the interfacial polymerization method, the oil phase component thus prepared is then blended with the aqueous phase component, a dispersion of oil phase microdroplets is prepared by stirring, and then interfacial polymerization is performed.
The aqueous phase component is prepared based on a medium that is immiscible with the oil phase component, and preferably water is used. It can be prepared by blending a dispersion stabilizer in this medium.
Examples of the dispersant include acrylic acid polymer, (meth) acrylic acid copolymer (a copolymer of acrylic acid ester such as methyl acrylate, acrylic acid amide, acrylonitrile, styrene sulfonic acid, vinyl acetate, etc.), maleic Acid copolymers (copolymers with styrene, ethylene, propylene, methyl vinyl ether, vinyl acetate, isobutylene), polymer substances such as carboxymethyl cellulose, polyvinyl alcohol, natural polysaccharides such as xanthan gum, gum arabic, and sodium alginate, poly Oxyethylene alkyl allyl ethers, polyoxyethylene alkyl ethers, polyoxyethylene alkyl esters, polyoxyethylene alkyl phenyl condensates, polyoxyethylene alkyl amino ethers, polyoxyethylene alkyl ethers Surfactants such as polyoxyethylene polyoxypropylene block polymers, polyoxyethylene sorbitan fatty acid esters, sorbitan fatty acid esters, alkylnaphthalene sulfonic acid formaldehyde condensates, or a combination of two or more thereof. As a method of use, a predetermined amount of a dispersant is dissolved in an aqueous phase component. These dispersants also have a function of stabilizing the dispersion system so that there is no sedimentation and aggregation in the microcapsule dispersion after the microcapsules are produced. As the dispersant, polyvinyl alcohol is more preferable. The blending ratio of the dispersant is preferably 20 parts by weight or less, more preferably 5 parts by weight or less based on 100 parts by weight of the aqueous phase component. As the concentration of the dispersant increases, a fine volume median diameter can be obtained.

  In order to mix the oil phase component with the water phase component, the oil phase component is added to the water phase component, and the mixture is stirred and dispersed with a Hiscotron, homomixer, etc. at room temperature until the oil phase becomes fine droplets. .

And the method of interfacial polymerization includes, for example, a method of dropping the water-soluble film forming component after dispersing the oil phase component in the aqueous phase component.
The water-soluble film forming component is not particularly limited as long as it reacts with the oil-soluble film forming component and undergoes interfacial polymerization, and examples thereof include polyamines and polyols. That is, when polyamine is used as the water-soluble film forming component, if the oil-soluble film forming component is polyisocyanate, polycarboxylic acid halide, or polysulfonic acid halide, the film component formed as a microcapsule film is Microcapsules of polyurea membrane, polyamide membrane, and polysulfonamide membrane are prepared. On the other hand, when a polyol is used as the water-soluble film forming component, if the oil-soluble film forming component uses polyisocyanate, polycarboxylic acid halide, or polysulfonic acid halide, the polyurethane film, the polyester film, or the polysulfonic acid ester film respectively. Microcapsules will be prepared.

Examples of the polyamine used in the present invention include ethylenediamine, propylenediamine, hexamethylenediamine, diaminotoluene, phenylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, and piperazine. Mixtures of more than one type may be used.
Examples of the polyol include ethylene glycol, propanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, dipropylene glycol, cyclohexanedimethanol, glycerin, trimethylolpropane, Examples thereof include polyethylene glycol and polypropylene glycol, and a mixture of two or more of these may be used.

  In the microcapsule mixed agricultural chemical composition of the present invention, polyamine is preferably used as a water-soluble film-forming component. The water-soluble film forming component is used as it is or as an aqueous solution thereof. In order to make the water-soluble film-forming component into an aqueous solution, it is preferably used at a concentration of 50% by weight or less of the water-soluble film-forming component. This water-soluble film-forming component has an equivalent amount of the reactive group of the water-soluble film-forming component with respect to the reactive group of the oil-soluble film-forming component (for example, when polyisocyanate and polyamine are used, an isocyanate group / Amino group equivalent ratio is approximately 1) and subjected to the interfacial polymerization.

By adding such a water-soluble film forming component dropwise to a dispersion in which fine oil droplets of the oil phase component containing the agrochemical component and the oil-soluble film forming component are dispersed in the water phase component, The film-forming component and the oil-soluble film-forming component react at the interface between the oil-phase component fine oil droplet and the water-phase component, a microcapsule film is formed by a polymerization reaction, and the microcapsules in which the active ingredient is encapsulated, It can be obtained as a dispersion in the aqueous phase. In the microcapsule mixed agricultural chemical composition of the present invention, polyisocyanate is preferably used as an oil-soluble film-forming component, polyamine is preferably used as a water-soluble film-forming component, and a polyurea film prepared by forming a film by an interfacial polymerization reaction. It is preferable to use microcapsules according to
In order to promote this interfacial polymerization reaction, it is preferable to carry out the reaction at a reaction temperature of 25 to 85 ° C., preferably 40 to 80 ° C., and a reaction time of 30 minutes to 24 hours, preferably 1 to 12 hours.

  In the microcapsules thus obtained, known additives such as thickeners, antifreezing agents, preservatives, and specific gravity regulators may be appropriately blended as necessary. Examples of thickeners include natural polysaccharides such as xanthan gum and locust beam, bentonites such as magnesium aluminum silicate, and semisynthetic polysaccharides such as carboxymethylcellulose. Antifreeze agents include urea or glycols such as propylene glycol and ethylene glycol. Examples of the preservative include 1,2-benzisothiazolin-3-one and 2-methyl-isothiazoline-3-one. Specific gravity regulators include water-soluble salts such as sodium sulfate.

In the microcapsule preparation according to the present invention, the volume median diameter of the applied microcapsule greatly affects the exertion of the soil pest control effect. The volume median diameter here refers to the average particle diameter on a volume basis, and refers to the particle diameter at a point that is 50% of the cumulative curve when the total curve of the group is 100%.
In the preparation of microcapsules, the type and concentration of the dispersant and the stirring conditions for dispersing the oil phase components (stirring model, stirring speed, stirring time, etc.) play an important role in adjusting to the target volume median diameter. The particle size of the microcapsules is almost determined in the process of forming a microdroplet in the core material in water and creating a dispersion system. In this process, the dispersant and the stirring method must be selected according to the capsule particle design. is important.

  Examples of the stirring model include Hiscotron (manufactured by Microtech Nichion Co., Ltd.) and a mixing analyzer (manufactured by Tokushu Kika Kogyo Co., Ltd.). As a stirring speed, it is preferable to stir in the range of 100-10000 rpm, and 1000-8000 rpm is more preferable. As stirring time, it is preferable to carry out in the range of 0.1 to 30 minutes, and the range of 0.5 to 15 minutes is more preferable. By increasing the stirring speed, microcapsules with a small volume median diameter can be prepared. In addition, microcapsules having a small volume median diameter can be prepared by increasing the stirring time.

  In the microcapsule mixture composition of the present invention, the volume median diameter of the microcapsules is, for example, using a commercially available laser diffraction particle size distribution analyzer, specifically SALD2200 (manufactured by Shimadzu Corporation), etc. It can be determined by measuring the volume median diameter and its distribution.

  The microcapsule mixed agricultural chemical composition of the present invention is characterized by combining and mixing microcapsule preparations having different volume median diameters. That is, the volume median diameter of the microcapsule (A) containing the nematicidal active ingredient as the first pesticide as compared with the microcapsule (B) containing the soil pest controlling active ingredient as the second pesticide. Specifically, it is preferable that the volume median diameter of the microcapsule (A) is 1 to 20 μm, and the volume median diameter of the microcapsule (B) is 20 to 100 μm. . In particular, nematodes have a very small body length, and accordingly, the microcapsule (A) is desired to have a smaller volume median diameter, and the volume median diameter of the microcapsule (A) is 1 to 10 μm. It is preferable that it is 1-5 micrometers. On the other hand, since the microcapsule (B) has a large body position of the pest to be controlled, it is desirable that the microcapsule (B) has a volume median diameter, and more preferably 30 to 80 μm.

  From another viewpoint, it is preferable that the weight ratio of each active ingredient of the first pesticide and the second pesticide in the microcapsule (A) and the microcapsule (B) is 1: 5 to 5: 1. The present invention has the effect of promoting the elution of the nematicidal active ingredient as the first pesticide from the microcapsule (A) by mixing two kinds of microcapsules. By increasing the composition content ratio, the elution promotion effect of the first agricultural chemical is enhanced. Therefore, more preferably, the composition content ratio in which the weight ratio of each active ingredient of the first pesticide and the second pesticide is mixed in the ratio of 1: 0.9 to 1: 2.

  The microcapsule mixed agricultural chemical composition of the present invention is prepared by the above-described microcapsule preparation method to prepare microcapsules (A) and (B) each having a defined volume median diameter, and then the microcapsules (A) and It can be obtained by mixing (B). Mixing may be performed by physical mixing. In the production method of the present invention, in the mixing step, it is convenient to perform mechanical stirring at a stirring force such that the respective microcapsules are not broken, and the stirring conditions are made constant. This enables uniform mixing. A blade, a propeller, a turbine, etc. can be used for stirring.

The microcapsule mixed agricultural chemical composition of the present invention may be produced by further adding an auxiliary agent to the nematicidal microcapsule (A) and soil pest-control microcapsule (B) and mixing them.
As auxiliary agents, thickeners, osmotic pressure regulators, pH adjusters, antifreeze agents, bactericides, antifungal agents, stabilizers, colorants, dispersants and the like can be used. For example, specific examples of adjuvants that can be applied include natural polysaccharides such as xanthan gum and locust beam as thickeners, bentonites such as magnesium aluminum silicate, semisynthetic polysaccharides such as carboxymethylcellulose, and osmotic pressure regulators. Examples include saccharides such as mannitol, glucose and sorbitol, and inorganic substances such as sodium chloride and potassium chloride. PH adjusting agents include acids such as phosphoric acid, acetic acid, hydrochloric acid and citric acid, bases such as sodium hydroxide, potassium hydroxide and ammonia. Examples of antifreeze agents include urea, and glycols such as propylene glycol and ethylene glycol. Examples of bactericides and antifungal agents include 1,2-benzisothiazolin-3-one and 2-methyl-isothiazoline- 3-on etc. As the stabilizer BHT and copper oxide and the like, various dyes as colorants, naphthalenesulfonic acid formaldehyde condensate as a surfactant, such as various dispersants and polystyrene maleic acid sodium salt can be used. Those which do not affect the microcapsule composition are preferable, and these can be used alone or in combination of two or more. Glycols are particularly preferred because they have a function of improving the association between microcapsules in addition to the antifreezing effect. These adjuvants can be used within a range of 0 to 30% by mass.

  The microcapsule mixed agricultural chemical composition of the present invention is usually diluted 10 to 200 times with respect to the total active ingredient weight of the composition, and directly treated on the soil by soil mixing, soil irrigation treatment or the like. It is preferable to use water as the diluent. Alternatively, it is possible to treat the soil as a microcapsule slurry as it is without removing the dispersion medium, which is an aqueous phase component used for microcapsule preparation, without performing a dilution operation. Alternatively, the dispersion medium can be removed and used as a microcapsule alone for soil treatment. Further, for example, it may be formulated into known dosage forms as appropriate, such as powders and granules.

  The microcapsule mixed pesticide composition of the present invention is mainly used as a pesticide for controlling pests in the soil where fruit trees, tea trees, vegetables and florets are grown. Examples of soil pests to be controlled include scarab beetle larvae, bark beetle larvae, bark beetle larvae, and kiss beetle horn beetles, and other examples include long-tailed butterflies, white-spotted beetles, white-spotted moths, white-spotted beetles, keratoes, German cockroaches, and others. Examples of nematodes include root-knot nematodes and root-knot nematodes. The microcapsule mixed pesticide composition of the present invention is effective in controlling both the above-mentioned soil pests and nematodes, and achieves simultaneous control of the soil pests and nematodes in one application of the pesticide composition. In addition, it is possible to achieve both the initial efficacy immediately after the application of the agricultural chemical and the long-term residual effect thereafter.

The action mechanism by which the microcapsule formulation exerts a pest control effect is the first mechanism by contact or absorption of the target pest due to leakage of the active ingredient of agricultural chemicals due to physical destruction of the microcapsule, or micro The second mechanism is the contact and absorption of the target pests by elution of the active ingredients of the agricultural chemicals from the capsule.
Regarding soil pest control, since the size of the pest itself is large, it is possible to destroy the microcapsule by movement of the target pest or feeding, and the contribution of the effect expression by the first action mechanism is large. Furthermore, from the viewpoint of securing the stability of the active ingredient and maintaining the medicinal effect for a long period of time, a preparation in which elution of the active ingredient from the microcapsule membrane is suppressed is desirable. Therefore, the microcapsule (B) containing a soil pest control active ingredient is large so that the drug elution is suppressed and the microcapsule is easily taken into the body of the target pest by feeding or the like, or is easily attached to the body surface. It is efficient to use a microcapsule formulation with a volume median diameter, and such a microcapsule formulation design is preferable.
On the other hand, with respect to nematode control, nematodes are very sucking organisms with a very small body size and cannot physically destroy microcapsules by exercise or feeding behavior. For this reason, only the direct contact of the nematicidal active ingredient eluted from the microcapsule which is the latter second mechanism of action contributes to the nematicidal activity expression. Furthermore, nematodes have the property of growing in the soil at high density, and in order to effectively exert nematode control effects in the soil, it is also important to be able to secure a high dose of nematicidal active ingredient. .
Usually, in order to increase the residual effect, the microcapsule preparation increases the film thickness and volume median diameter of the microcapsule, but adjusting these decreases the elution property of the active ingredient and lowers the initial effect. On the other hand, when the film thickness or volume median diameter is reduced, the elution of the agrochemical active ingredient is increased and the initial effect is ensured, but the inconvenience is reduced. For soil pest control, even if the formulation of the microcapsules is adjusted to increase the residual effect, the initial effect is based on the first action mechanism by contact of the pests and physical destruction of the microcapsules. Can also be expected. However, as a microcapsule preparation for nematicidal control, the initial effect cannot be expected as the property that the capsule cannot be broken by nematodes and the soil pest control agent. Therefore, the necrotic microcapsule (A) has a small volume median diameter, and by increasing the surface area of the microcapsule, the amount of microcapsule (A) attached to the nematode is increased and the eluted nematicidal It is necessary to design a microcapsule formulation that increases the nematicidal effect on nematodes by increasing the amount of contact with the insect active ingredient.

  Furthermore, the microcapsule mixed composition according to the present invention mixes the other micropowder for controlling insect pests (B) with the microcapsule for nematicide (A), so that the nematode microcapsule (A) A new effect was found in the mixture of both agents that exerted the action of promoting the elution of the nematicidal active ingredient. This effect further increased the amount of sensitization of the nematicidal active ingredient to nematodes, making it possible to ensure the initial effect. Therefore, the microcapsule mixed composition for simultaneously controlling soil pests and nematodes by spraying a pesticide composition once is a preparation in which the microcapsules for nematicide (A) have the ability to enhance drug dissolution. It is a formulation design in which the microcapsules (B) for controlling soil pests have a performance that increases the probability of contact with the target pests and suppresses drug dissolution as much as possible. In the microcapsule mixed composition of the present invention, the water elution rate of each encapsulated drug under shaking at 25 ° C. for 20 minutes is 10% or more for nematicide microcapsules (A), and is used for controlling pests in soil. The microcapsule (B) is substantially suppressed in elution and has a compositional property of 1% or less in water.

Hereinafter, the present invention will be described in more detail with reference to production examples and examples. Moreover, the prepared microcapsule measured the volume median diameter with the following analytical instruments and analysis conditions.
Analytical instrument: Laser diffraction particle size distribution analyzer SALD-2200 (manufactured by Shimadzu Corporation)
Measurement method: Laser diffraction and laser scattering method Measurement range: 0.03 to 1000 μm
Light source: Semiconductor laser (wavelength 680 nm, output 3 mW)
Cell: Batch cell type Cell material: Quartz glass Software: WingSALD-2200
Analysis sample: Prepared microcapsules were prepared by adding water and dispersing so that the active ingredient had a concentration of 0.1 to 0.25% by weight.

Production Example 1
MR-400 ((trade name), polymethylene polyphenyl polyisocyanate, Nippon Polyurethane as an oil-soluble film-forming component in 236 parts by weight of (2-isopropyl-4-methylpyrimidyl-6) -diethylthiophosphate (generic name: diazinon) 22 parts by weight (manufactured by Co., Ltd.) and 81 parts by weight of Solvesso 150 ((trade name) manufactured by Exxon Chemical Co., Ltd.) as a solvent were added and mixed uniformly to prepare an oil phase component. In another container, 444 parts by weight of a 0.5% by weight aqueous solution of Gohsenol AL-06 ((trade name), polyvinyl alcohol, manufactured by Nippon Synthetic Chemical Co., Ltd.) as a dispersant is placed and heated to 30 ° C., and the aqueous phase Ingredients were prepared. The oil phase component and the water phase component are put into a 1 L container, and the mixture is stirred for 10 minutes at 2000 rpm using a mixing analyzer 2500 type (manufactured by Tokushu Kika Kogyo Co., Ltd.) to disperse the oil phase component. A mold emulsion was prepared. A mixed solution of 6 parts by weight of ethylenediamine and 6 parts by weight of diethylenetriamine was added thereto as a water-soluble film forming component, and the mixture was reacted at 60 ° C. for 3 hours with stirring to prepare a microcapsule-containing liquid for a polyurea film. To this, 100 parts by weight of a 50% aqueous solution of propylene glycol and 50 parts by weight of a 2% aqueous solution of xanthan gum were added and mixed uniformly, and a dispersion containing microcapsules (B) for controlling soil pests having a diazinon content of 25% by weight Got. The measured value of the volume median diameter of the obtained macrocapsule was 40 μm.

Production Example 2
219 parts by weight of S, S-di-sec-butyl-O-ethyl-phosphorodithioate (generic name: kazusafos) and MR-400 ((trade name) polymethylene polyphenyl polyisocyanate as an oil-soluble film-forming component 82 parts by weight of Nippon Polyurethane Co., Ltd., and 88 parts by weight of Solvesso 150 (trade name, manufactured by Exxon Chemical Co., Ltd.) as a solvent were added and mixed uniformly to prepare an oil phase component. 410 parts by weight of a 3% aqueous solution of Gohsenol AL-06 ((trade name) polyvinyl alcohol, manufactured by Nippon Synthetic Chemical Co., Ltd.) was placed in another container and heated to 30 ° C. to prepare an aqueous phase component. The oil phase component and the water phase component are put into a 1 L container, and the mixture is stirred for 1 minute at a rotation speed of 8000 rpm using a mixing analyzer 2500 type (manufactured by Tokushu Kika Kogyo Co., Ltd.) to disperse the oil phase component. A mold emulsion was prepared. To this was added a mixed solution of 27 parts by weight of ethylenediamine and 27 parts by weight of diethylenetriamine as a water-soluble film forming component, and the mixture was reacted at 60 ° C. for 3 hours with stirring to prepare a microcapsule-containing liquid of a polyurea film. To this was added 200 parts by weight of a 50% aqueous solution of propylene glycol and 100 parts by weight of a 2% aqueous solution of xanthan gum, mixed uniformly, and a dispersion containing necrotic microcapsules (A) having a kazusafos content of 19% Got. The measured value of the volume median diameter of the obtained microcapsules was 3.5 μm.

Production Example 3
Production Example, except that the aqueous phase component in Production Example 1 was prepared by changing the aqueous solution of GOHSENOL AL-06 ((trade name), polyvinyl alcohol, manufactured by Nippon Synthetic Chemical Co., Ltd.) to a 0.2% by weight aqueous solution. A microcapsule was prepared using the same raw materials and operations as in No. 1 to obtain a dispersion containing microcapsules (B) for controlling soil pests having a diazinon content of 25%. The measured value of the volume median diameter of the obtained microcapsules was 68 μm.

Production Example 4
In the operation for preparing the aqueous phase component in Production Example 2, the same procedure as in Production Example 2 was performed except that stirring using a mixing analyzer 2500 type (manufactured by Tokushu Kika Kogyo Co., Ltd.) was changed to 1 minute at a rotation speed of 6000 rpm. A microcapsule was prepared using the above raw materials and operations to obtain a dispersion containing nematicide microcapsules (A) having a kazusafos content of 19%. The measured value of the volume median diameter of the obtained microcapsules was 15.1 μm.

Production Example 5
In the operation of preparing the aqueous phase component in Production Example 2, an aqueous solution of GOHSENOL AL-06 ((trade name), polyvinyl alcohol, manufactured by Nippon Synthetic Chemical Co., Ltd.) was changed to a 0.3 wt% aqueous solution, and mixing analyzer 2500 type (special A microcapsule was prepared with the same raw materials and operation as in Production Example 2 except that stirring using Kika Kogyo Co., Ltd. was changed to 10 minutes at a rotational speed of 2000 rpm. A dispersion containing the insect microcapsules (A) was obtained. The measured value of the volume median diameter of the obtained microcapsules was 51 μm.

Example 1
300 parts by weight of the pest control (diazinon) -containing microcapsules (B) obtained in Production Example 1 and 300 parts by weight of the nematicide (Kazusafos) -containing microcapsules (A) obtained in Production Example 2 The mixture was added dropwise with stirring at 600 rpm with a two-stage propeller stirrer at a temperature of ° C. This was stirred for 10 minutes to obtain a microcapsule mixed agricultural chemical composition. The diazinon content was 12.5% by weight and the kazusafos content was 9.5% by weight.

Example 2
150 parts by weight of the pest control (diazinone) -containing microcapsules (B) obtained in Production Example 1 and 25 parts by weight of the nematicidal (Kazusafos) -containing microcapsules (A) obtained in Production Example 2 The mixture was added dropwise with stirring at 600 rpm with a two-stage propeller stirrer at a temperature of ° C. This was stirred for 10 minutes to obtain a microcapsule mixed agricultural chemical composition. The diazinon content was 8.33% by weight and the kazusafos content was 12.7% by weight.

Example 3
300 parts by weight of the pest-controlling (diazinone) -containing microcapsules (B) obtained in Production Example 1 and 150 parts by weight of the nematicidal (Kazusafos) -containing microcapsules (A) obtained in Production Example 2 The mixture was added dropwise with stirring at 600 rpm with a two-stage propeller stirrer at a temperature of ° C. This was stirred for 10 minutes to obtain a microcapsule mixed agricultural chemical composition. The diazinon content was 16.7% by weight and the kazusafos content was 6.33% by weight.

Example 4
To 380 parts by weight of the soil pest control (diazinone) -containing microcapsules (B) obtained in Production Example 1, 285 parts by weight of the nematicide (Kazusafos) -containing microcapsules (A) obtained in Production Example 2 While stirring at 600 rpm with a two-stage propeller stirrer at a temperature of ° C., 35 parts by weight of propylene glycol was added and stirred for 10 minutes to obtain a microcapsule mixed agricultural chemical composition. The diazinon content was 13.6% by weight and the kazusafos content was 7.74% by weight.

Example 5
285 parts by weight of the microcapsule (B) containing soil pest control (diazinone) obtained in Production Example 1 and 285 parts by weight of the microcapsule composition containing Kazusafos obtained in Production Example 2 were added at 25 ° C. The mixture was added dropwise with stirring at 600 rpm with a two-stage propeller stirrer, and then 30 parts by weight of propylene glycol was added and stirred for 10 minutes to obtain a microcapsule mixed agricultural chemical composition. The diazinon content was 11.9% by weight and the kazusafos content was 9.03% by weight.

Example 6
190 parts by weight of the soil pest control (diazinone) -containing microcapsules (B) obtained in Production Example 1 and 285 parts by weight of the nematicide (Kazusafos) -containing microcapsules (A) obtained in Production Example 2 While stirring at 600 rpm with a two-stage propeller stirrer at a temperature of ° C., 25 parts by weight of propylene glycol was added and stirred for 10 minutes to obtain a microcapsule mixed agricultural chemical composition. The diazinon content was 9.50% by weight and the kazusafos content was 10.8% by weight.

Example 7
25 microparts (B) containing soil pest control (diazinone) obtained in Production Example 1 was added to 285 parts by weight, and 190 parts by weight of microcapsules (A) containing nematocide (Kazusafos) obtained in Production Example 2 were added to 25 parts by weight. While stirring at 600 rpm with a two-stage propeller stirrer at a temperature of ° C., 25 parts by weight of propylene glycol was added and stirred for 10 minutes to obtain a microcapsule mixed agricultural chemical composition. The diazinon content was 14.3% by weight and the kazusafos content was 7.22% by weight.

Example 8
To 380 parts by weight of the soil pest control (diazinone) -containing microcapsules (B) obtained in Production Example 3, 285 parts by weight of the nematicide (Kazusafos) -containing microcapsules (A) obtained in Production Example 2 The mixture was added dropwise with stirring at 600 rpm with a two-stage propeller stirrer at a temperature of 0 ° C., and stirred for 10 minutes to obtain a microcapsule mixed agricultural chemical composition. The diazinon content was 14.3% by weight and the kazusafos content was 8.14% by weight.

Example 9
To 380 parts by weight of the soil pest control (diazinone) -containing microcapsules (B) obtained in Production Example 1, 285 parts by weight of the nematicidal (Kazusafos) -containing microcapsules (A) obtained in Production Example 4 The mixture was added dropwise with stirring at 600 rpm with a two-stage propeller stirrer at a temperature of 0 ° C., and stirred for 10 minutes to obtain a microcapsule mixed agricultural chemical composition. The diazinon content was 14.3% by weight and the kazusafos content was 8.14% by weight.

Comparative Example 1
To 380 parts by weight of the soil pest control (diazinone) -containing microcapsules (B) obtained in Production Example 1, 285 parts by weight of the nematode (Kazusafos) -containing microcapsules (A) obtained in Production Example 5 While stirring at 600 rpm with a two-stage propeller stirrer at a temperature of ° C., the mixture was added dropwise and stirred for 10 minutes to obtain a microcapsule mixed agricultural chemical composition. The diazinon content was 14.3% by weight and the kazusafos content was 8.14% by weight.

Comparative Example 2
4 kg of microcapsules (B) containing soil pest control (diazinone) of Production Example 1 (1.0 kg as diazinon), and 1 kg of guard hope solution ((trade name) manufactured by Ishihara Sangyo Co., Ltd., 30% phosphiazate content) 0.3 kg as phostiazate) was uniformly mixed in a plastic container at a temperature of 25 ° C.

Test example 1 (mixing stability test)
Examples 1 to 3, and as a control example, kazusafos base (control example 1), diazinon base (control example 2), and these bases in a weight ratio of 1: 2 (control example 3), 1: 1 (control) Example 4) The drug substance mixed composition mixed in 2: 1 (Control Example 5) was sealed in a glass ampoule and stored in a constant temperature bath at 54 ° C. for 2 weeks. A stability test was performed. Each test sample after the storage period under accelerated conditions was quantitatively analyzed for kazusafos and / or diazinon by the following analysis method, and the stability test of each sample was performed. The results are shown in Table 1.

  The content analysis method of the kazusafos drug substance (Control Example 1), the diazinon drug substance (Control Example 2) drug substance samples, and these drug substance mixture samples (Control Examples 3 to 5) was added to 200 parts by weight of each test sample. After adding 20 parts by weight of an internal standard substance (4,4′-dichlorobenzophenone), 100 parts by weight of acetonitryl was added to obtain an analytical sample solution. Separately, 100 parts by weight of diazinon and 100 parts by weight of kazusafos were weighed, 20 parts by weight of an internal standard substance (4,4′-dichlorobenzophenone) and 100 parts by weight of acetonitryl were added to obtain a standard solution. The standard solution and the analysis sample solution were each analyzed by high performance liquid chromatography, and the content of kazusafos and / or diazinon in each sample was determined by an internal standard analysis method.

  In the microcapsule mixed sample (Examples 1 to 3), each kazusafos and / or diazinon content analysis method was performed by weighing 800 parts by weight of each test sample, 10 parts by weight of silica sand, and (4,4 ' -Dichlorobenzophenone) 130 parts by weight and 40 parts by weight of acetone were added and shaken for 1 hour, followed by filtration to obtain an analytical sample solution. Separately, 200 parts by weight of diazinon and kazusafos were weighed, and 130 parts by weight of (4,4′-dichlorobenzophenone) as an internal standard substance and 40 parts by weight of acetone were added to obtain a standard solution. The analysis sample solution and the standard solution were injected into gas chromatography, and the contents of kazusafos and / or diazinon in each sample were determined by an internal standard analysis method.

Table 1 Sample of mixing stability test results Initial content Content after storage Decomposition rate (%)
Example 1 CD content 9.6 9.6 0.0
DZ content 13.0 12.9 0.8
Example 2 CD content 12.7 12.5 1.6
DZ content 8.5 8.5 0.0
Example 3 CD content 6.3 6.2 1.6
DZ content 17.1 16.9 1.2

Control Example 1 (CD bulk) CD content 91.1 90.0 1.2
Control Example 2 (DZ base) DZ content 94.4 87.0 7.8
Control 3 CD content 30.2 30.0 0.7
(CD 1: DZ 2) DZ content 63.1 56.3 10.8
Control Example 4 CD content 46.7 46.1 1.3
(CD 1: DZ 1) DZ content 46.1 37.4 18.9
Control Example 5 CD content 61.3 60.4 1.5
(CD 2: DZ 1) DZ content 31.4 22.8 27.4
CD: Kazusafos, DZ: Diazinon

As is apparent from the results in Table 1, diazinon, which is an active ingredient for controlling soil pests, has a degradation rate of 7.8% by weight in the diazinon raw material sample (control example 2), and has relatively low physicochemical stability. It was a physical property. When kazusafos was added to this, the decomposition of diazinon was promoted, and a marked decrease in mixing stability was observed (Control Examples 3 to 5). In the bulk mixing, the decomposition of diazinon tended to be accelerated as the amount of kazusafos was increased. Kazusafos is known to be stable in the acidic region, and diazinon is known to be stable in the basic region, and each has different physicochemical stability characteristics. It is thought to happen.
On the other hand, in Examples 1 to 3, which are mixed compositions of the kazusafos-containing microcapsules and the diazinon-containing microcapsules of the present invention, the decomposition of diazinon was kept low at any mixing ratio. The microcapsule mixed composition of the present invention was confirmed to be stable in terms of distribution, and the effectiveness of the mixed preparation was confirmed even when prescribing a combination preparation in which agrochemicals with different stability regions were mixed in pots. .

Test example 2 (water dissolution test)
Microcapsules when Examples 4 to 9 and Production Examples 1 to 5 which are individual samples of microcapsules as a comparative sample and Comparative Example 1 which is a microcapsule mixed preparation were shaken in water at 25 ° C. for 20 minutes The water dissolution rate of the active ingredients from was measured. The results are shown in Table 2.
Here, the dissolution rate in water refers to the dissolution rate of active ingredients from microcapsules in 300 parts by weight of water, which is calculated from the following formula based on the total amount of active ingredients. As a test method and an analysis method, 1 part by weight of the test microcapsule composition was weighed and 300 parts by weight of water was added to prepare a test sample. This was shaken for 20 minutes at a speed of 270 rpm, and filtered through a membrane filter having a pore size of 1 μm to obtain a sample solution. Separately, an acetonitrile solution of 20 ppm kazusafos and 5 ppm diazinon was prepared as a standard solution. The standard solution and the sample solution were analyzed by high performance liquid chromatography, the respective elution amounts were determined, and the elution rates in water of diazinon and kazusafos were calculated.

Elution amount (mg) = standard solution (ppm) × 0.3 (L) × (AT / AS)
AT: Peak area of sample solution AS: Peak area of standard solution [Formula 1]: Elution rate in water (%) = elution amount (mg) / total active ingredient amount (mg) × 100
Is calculated by

Table 2 Elution test in water
Active ingredient ratio Volume median diameter (μm) Elution rate in water (%)
Sample CD: DZ CD DZ CD DZ
Example 4 1: 1.8 3.5 40 25.0 0.1
Example 5 1: 1.3 3.5 40 24.1 0.1
Example 6 1: 0.9 3.5 40 22.1 0.1
Example 7 1: 2.0 3.5 40 29.3 0.1
Example 8 1: 1.8 3.5 68 16.9 0
Example 9 1: 1.8 15.1 40 13.8 0.1

Production Example 1 DZ-MC-40-0.1
Production Example 2 CD-MC 3.5-15.4-
Production Example 3 DZ-MC-68-0
Production Example 4 CD-MC 15.1-11.0-
Production Example 5 CD-MC 51 -0.6-
Comparative Example 1 1: 1.8 51 40 0.4 0.1
CD: Kazusafos, DZ: Diazinon, DZ-MC; Diazinon microcapsule, CD-MC; Kazusafos microcapsule

As is clear from Table 2, in the examples and comparative examples, the elution rate of diazinon in microcapsules enclosing diazinon is 0.0 to 0.1% in all cases, and almost no elution is observed in the aqueous dispersion. I couldn't. In soil pest control, contact and absorption of leaked pesticides by physical destruction of microcapsules due to the action of the target pests are assumed to be the main mechanism of drug sensitization of the target pests. From the viewpoint of securing the properties, the dissolution rate of the active ingredient included was low, and desirable physical properties were shown.
On the other hand, the elution rate of kazusafos in water in the microcapsules enclosing kazusafos tended to show higher elution in water as the volume median diameter was smaller. This is thought to be because the surface area of the microcapsule increases as the volume median diameter decreases, and the release of kazusafos from the microcapsule surface is promoted. Furthermore, in the examples, mixing of the diazinon microcapsule composition was found to promote the release of kazusafos. This tendency becomes more prominent as the volume median diameter of the kazusafos-encapsulated microcapsules is smaller, and was observed when the volume median diameter of the kazusafos-encapsulated microcapsules was 20 μm or less.
On the other hand, in the composition containing the kazusafos-encapsulated microcapsules having a volume median diameter of 51 μm in Comparative Example 1, the elution promoting effect of kazusafos was not observed. In order to achieve the dissolution promotion effect of kazusafos, an optimal combination of the volume median diameters of the two microcapsule preparations was necessary. In particular, a composition in which the volume median diameter of the microcapsules in kazusafos was 3.5 μm and the microcapsules in which diazinon was included was 40 μm exhibited a remarkable elution promoting effect of kazusafos.
Further, as the active ingredient ratio in mixing, the higher the diazinon ratio, the higher the elution rate of kazusafos in water. In order to promote elution of kazusafos, it was achieved by increasing the active ingredient ratio of diazinon by 0.9 or more than kazusafos, and it was a desirable mixed composition in order to exert a sufficient nematicidal control effect.

  The microcapsule mixed composition of Comparative Example 1 has a low elution rate of kazusafos in water, and thus there is a possibility that sufficient initial efficacy against nematodes cannot be obtained. In order to secure the amount of kazusafos-eluting active ingredient, it is necessary to increase the composition content of the kazusafos-encapsulated microcapsule formulation, but this increases the cost of the agricultural chemical formulation and may further increase the phytotoxicity. Also, depending on the pesticide, the total amount used is limited and it is difficult to increase the dose. From the above results, it is preferable that the active ingredient ratio is larger than diazinone than kazusafos, and the nematicidal microcapsule having a volume median diameter range of 1 to 20 μm and soil pest control having a range of 20 to 100 μm. In the microcapsule mixed pesticide composition of microcapsules, elution of the drug from nematicidal microcapsules was promoted, and it was confirmed that the formulation characteristics were expected to ensure the initial application effect in nematode control. .

Test Example 3 (Scarab beetle nematode test)
Example 4-7 was treated as 15 m ² (3.0 × 5.0 m) per section, and the amount of treatment per section was 104 g (Diazinon; 14.1 g, Kazusafos 8.05 g), Example 5 90 g (diazinone; 10.7 g, kazusafos; 8.13 g), 75 g of example 6 (diazinone; 7.13 g, kazusafos; 8.12 g) and 75 g of example 7 (diazinone; 10.7 g, kazusafos; 5 .42 g) was diluted with water so that the amount of the treatment liquid per 1 liter became 1.5 L, and evenly sprayed with a watering can. After spraying, the entire soil was mixed. As a comparative example, 75 g (diazinone; 15 g, phostiazate; 4.5 g) of Comparative Example 2 was diluted with water so that the amount of treated water per section was 1.5 L, and uniformly dispersed with a watering can. The soil was mixed after spraying. After that, veneers were planted by 3 cm at a spacing of 100 cm and 1 row at a spacing of 30 cm between plants. In addition, about 70 L of soil on which Nekob nematode was grown 9 days before the chemical treatment was inoculated, and the entire surface was mixed with soil.
120 days, 147 days, and 174 days later, one of the three cocoons in each ward was dug, and the damage of crops caused by scarab beetles larvae and nematodes was examined for the 10 strains in the center. The results are shown in Table 3.

In addition, the damage situation by the scarab beetle larva was represented by the damage degree of the crop calculated by the following formula 2.
[Formula 2]: Damage level = (about 1 + about 2 × 2 + about 3 × 3) / (number of investigations × 3) × 100
Degree 1: Damage mark is small and A product can be shipped. Degree 2: Although there is damage mark, B product can be shipped. Degree 3: Many damage marks and nonstandard products.

Moreover, the damage situation by a nematode was represented by the damage degree of the crop calculated by the following formula 3.
[Expression 3]: Damage level = (about 1 + about 2 × 2 + about 3 × 3) / (number of investigations × 3) × 100
About 1: The number of roots is about 1-2.
Degree 2: The number of root bumps is large but not recognized in the main root.
Degree 3: The number of humps is large, and it is also recognized in the main root.

Table 3 Scaraba beetle nematode test results in veneers
Damage degree (Scarabaeidae larvae) Damage degree (Nematode)
Sample 120 days 147 days 174 days 120 days 147 days 174 days Example 4 1.9 0.0 1.5 0.0 0.0 0.0
Example 5 2.6 5.0 4.3 0.0 0.0 0.0
Example 6 0.0 23.9 0.0 0.0 0.0 0.0
Example 7 0.0 4.4 13.1 0.0 0.0 0.0
Comparative Example 2 2.5 0.0 1.1 0.0 0.0 0.0 0.0
No treatment 75.2 74.7 75.4 43.6 77.0 67.1

  As is clear from Table 3, crop damage caused by scarab beetles larvae was observed in untreated areas. The results of Example 4 were the same as those of Comparative Example 2 in Example 4, and the damage level was also low in Examples 5 to 7 with a small amount of diazinon, indicating a stable effect against scarab beetles. As can be seen from Test Example 2, the microcapsule mixed compositions of Examples 4 to 7 were those in which the dissolution of diazinon was suppressed, but exhibited a strong control effect against scarab beetles. In addition, in the damage of nematode, a bud grew on the root of the untreated potato, and the damage level was recognized. On the other hand, no growth of the aneurysm was observed in the examples and comparative examples, and no damage to the crops due to nematodes was observed. It was shown that the elution form of this microcapsule composition enabled simultaneous control of scarab beetles larvae and nematodes.

Test Example 4 (Nematode density test)
The soil around the crop was collected in the area where Test Example 3 was conducted, and the nematode density in the soil indicated by the number of nematodes per 30 g of soil measured by the Beerman method was investigated. The results are shown in Table 4.
The Beerman method is an operation for separating nematodes from soil. Place the soil wrapped with a bleached cloth on a stainless steel or nylon net and set it in a funnel soaked in water. This is a method of allowing nematodes to enter the water by separating the water at the bottom of the funnel after leaving overnight at ℃.

The nematode density of each soil is indicated by the nematode density index calculated by the following formula 4.
[Formula 4] Nematode density index (%) = number of nematodes in treated group / number of nematodes in untreated group × 100

Table 4 Nematode density test
Nematode density index (%)
Sample Before treatment 30 days 60 days 90 days 120 days 147 days 174 days Example 4 220 7.1 19.6 3.2 2.8 2.9 3.0
Example 5 96.7 3.6 9.1 8.2 7.7 7.3 6.3
Example 6 168 2.7 19.6 2.7 2.4 2.4 3.2 3.5
Example 7 153 13.4 43.0 1.6 2.7 3.6 3.2
Comparative Example 2 83.2 41.9 59.2 28.4 22.2 33.3 34.4
No treatment 100 100 100 100 100 100 100

Test Example 4 examined the detailed nematode control effect. As is clear from the results in Table 4, Examples 4 to 5 showed a difference in nematode density index as compared with Comparative Example 2. In Examples 4 to 7, it was confirmed that the nematode density index in the soil was suppressed to about 10% or less. On the other hand, in the comparative example, the nematode density index changed in the range of 20% to 60%, and the example showed a higher effect than the comparative example. In the examples, the effect was stably maintained from the beginning to 174 days, and it was confirmed that the residual effect and stability of kazusafos, which is a nematicide, were sufficiently achieved.
From the above, in order to keep the nematode density low over a long period of time, it is effective to promote elution of the nematode control agent by mixing two kinds of microcapsule compositions with soil pests and nematode control agents. A sufficient effect was also confirmed in gender. Further, as shown in Test Example 3, since the control of soil pests was achieved with a stable effect, it was shown that the present invention is useful for the simultaneous control of soil pests and nematodes.

Claims (7)

  A microcapsule mixed pesticide composition containing a microcapsule (A) containing a nematicidal active ingredient as a first pesticide and a microcapsule (B) containing a soil pest control active ingredient as a second pesticide A microcapsule mixed agricultural chemical composition in which the volume median diameter of the microcapsules (A) is in the range of 1 to 20 μm, and the volume median diameter of the microcapsules (B) is 20 to 100 μm.   The microcapsule mixed agricultural chemical composition according to claim 1, wherein at least one of the first agricultural chemical and the second agricultural chemical is an organic phosphorus agent.   The first pesticide is O-ethyl-Sn-propyl (2-cyanoimino-3-ethylimidazolidin-1-yl) phosphonothiolate (generic name: imisiaphos), S, S-di-sec-butyl. -O-ethyl-phosphorodithioate (generic name: kazusafos), (R, S) -S-sec-butyl-O-ethyl-2-oxo-1,3-thiazolidine-ylphosphonothioate (generic name: Any one or more organophosphorus nematicidal active ingredients selected from the group consisting of phostiazates), wherein the second pesticide is O, O-diethyl-O-2-isopropyl-6-methylpyrimidine- 4-yl-phosphorothioate (generic name: diazinon), O, O-dimethyl-O-4-methylthio-m-toluyl-phosphorothioate (generic name: fenthion), O, O It is any one or more organophosphorus soil pest control agents selected from the group consisting of dimethyl-O-4-nitro-m-toluyl-phosphorothioate (generic name: fenitrothion). The microcapsule mixed agricultural chemical composition according to Item.   The microcapsule mixed agricultural chemical composition according to any one of claims 1 to 3, wherein an active ingredient ratio of the first agricultural chemical and the second agricultural chemical is 1: 5 to 5: 1.   The microcapsule mixed agricultural chemical composition according to any one of claims 1 to 4, wherein glycols are added.   A method for controlling soil pests, wherein the microcapsule mixed agricultural chemical composition according to any one of claims 1 to 5 is diluted 10 to 200 times with respect to the total amount of active ingredients and sprayed directly onto the soil.   The method for controlling soil pests according to claim 6, wherein soil nematodes and soil pests are controlled simultaneously.