JP2021123581A - Microcapsule agrochemical composition - Google Patents

Abstract

To provide a microcapsule agrochemical composition, which secures safety of a worker who sprays the agrochemical and stability of the formulation, where an initial effect by disintegration or elution for achieving a sufficient effect against pest insects and sufficient strength and stability of microcapsules are maintained.SOLUTION: Microcapsules having a volume median diameter of 1 to 50 μm and a film thickness of 5 to 50 nm are prepared through an O/W emulsion dispersing step using a specific dispersant. Thereby, a high rate of inclusion in capsules, rapid releasability, and strength and stability of capsules are achieved.SELECTED DRAWING: Figure 2

Description

The present invention relates to the field of pesticide preparations for controlling pests, and more particularly to the field of microcapsule pesticide preparations.

Currently, various pesticides are used around the world to control pests that damage crops. Agricultural chemicals are indispensable products in modern times because they increase the value of crops and enable them to continuously provide safe crops to consumers. In recent years, exposure to workers by spraying pesticides has become a problem, and the Ministry of Agriculture, Forestry and Fisheries has enforced guidelines on worker exposure as a law. This sets new standards for worker exposure when spraying pesticides, and in the case of highly toxic pesticides, there is a possibility that the amount used will be reduced or the pesticides will not be usable. As a result, farmers are concerned that the amount of pesticides they can use on their crops will decrease, and that the quality and value of their crops may not be preserved.

It is conceivable to use a microcapsule preparation as a countermeasure against worker exposure of pesticides. Since the active ingredient of the pesticide is wrapped in a membrane in the microcapsule preparation, even if the worker is exposed to it during spraying, direct contact is avoided, so that it can be expected to have low toxicity and high safety. In addition, since the disappearance and decomposition of the active ingredient after spraying are suppressed and the residual effect is extended, long-term control effect can be expected, which leads to labor saving for farmers, and is a very useful pesticide preparation. However, in order to exert a stable control effect, detailed design for encapsulation and control of release of the pesticide active ingredient of the microcapsule preparation is required.

Patent Document 1 proposes a microcapsule agent having excellent initial insecticidal activity and long-term residual effect by mixing two types of microcapsules having different film thicknesses. However, the microcapsules are manufactured by the In-Situ method instead of the interfacial polymerization method, and the film material is composed of a very hard melamine resin. Further, although the microcapsules having a thin film thickness in the literature are excellent in the initial residual effect, a residual effect of 30% or more has been confirmed even 14 days after spraying, and there is a concern that the microcapsules may remain depending on the active ingredient. In addition, the active ingredient of pesticides is limited to pyrethroids, and not all active ingredients are effective.
Patent Documents 2 to 4 propose a method of controlling the elution of the pesticide active ingredient contained in the microcapsules by adding a surfactant or the like to the diluent without changing the composition of the microcapsules. However, since 0.1% of the surfactant is added to 1 L of the 1000-fold diluted solution of the preparation and the amount of the surfactant is the same as that of the preparation, the amount is too large to be added as the surfactant in the preparation. Too many. Further, when the pesticide is sprayed, the pesticide preparations are generally mixed and the spreading agent, which is a surfactant-based preparation, is generally used. Therefore, the elution control when the pesticide is used in combination becomes unclear and is not useful. In addition, the pesticide active ingredient is limited to pyriproxyfen, and not all pesticide active ingredients are effective.

Patent Document 5 describes when a microcapsule aqueous suspension composition containing a pesticide active ingredient and having a volume particle size in a specific particle size band is transferred by a pump or sprayed using a chemical sprayer. As described above, even when the microcapsules are subject to physical impact, the microcapsules are reported to be difficult to be destroyed. However, the strength of the microcapsules is greatly affected by the film thickness and the formulation of the composition, and it is expected that the impact will differ depending on the nozzle diameter of the pump or chemical sprayer used and the spraying method.

The microcapsule preparation is a pesticide preparation that exerts a desired control effect by sensitizing the target pest by rupturing the pesticide component enclosed in the film by an external factor or self-eluting the active ingredient from the inside. In order for the microcapsule preparation to exert a quick initial effect, a thin film thickness is required to make it easier for the capsule film to rupture. There is a concern that the capsule film may burst. On the other hand, in order to have a residual effect, it is necessary to increase the film thickness of the capsule film, but the residual pesticide becomes a problem depending on the crop. Therefore, in the formulation design of the microcapsule formulation for foliar spraying, it is important to design the dissolution mechanism of the encapsulated pesticide, control the dissolution rate of the encapsulated pesticide, and appropriately select the encapsulated pesticide. In particular, the foliage spray agent is often required to have an initial effect, but the microcapsule preparation may not exhibit a rapid initial effect due to the above reasons, and the efficacy may be insufficient or the active ingredient may remain.

Japanese Unexamined Patent Publication No. 10-59812 Japanese Patent No. 5202909 Japanese Patent No. 5202910 Japanese Patent No. 5223273 Japanese Patent No. 4882313

Exposure to workers by spraying pesticides has become a problem, and there is a need for pest control pesticides that can be safely sprayed by pesticide sprayers. In addition, a pest control pesticide preparation is required to exert a sufficient initial control effect in the initial stage of pesticide application. Therefore, as a microcapsule formulation that can alleviate the problem of spray exposure of workers, it can withstand the spraying pressure of pesticides and has a high active ingredient inclusion rate, but it releases the active ingredient promptly after spraying and has an initial control effect. A microcapsule preparation that can exert the above is required. An object of the present invention is to solve the above problems.
That is, the present invention uses the microcapsule formulation technology to ensure the safety and formulation stability of the pesticide sprayer, and the initial effect of disintegration or elution to achieve a sufficient effect on pests. An object of the present invention is to provide a microcapsule pesticide composition by sufficiently maintaining the strength and stability of the microcapsules.

As a result of diligent research to solve the above problems, the present inventors have obtained microcapsules having a volume median diameter of 1 to 50 μm and a film thickness of 5 to 50 nm as O / W emulsions using a specific dispersant. By preparing through a dispersion step, it has been found that the capsule encapsulation rate is high, the release property is rapid, and the desired effect can be achieved, and the present invention has been completed.
That is, the gist of the present invention is the following [1] to [11].

[1] A microcapsule pesticide composition containing a microcapsule containing a pesticide active ingredient having a water solubility of 1000 ppm or less at 20 ° C. and an aqueous phase.
The volume median diameter of the microcapsules is 1 to 50 μm, and the film thickness of the microcapsules defined by the following formula (I) is 5 to 50 nm.
The microcapsule membrane is a microcapsule composed of a polyurea membrane having an aromatic ring structure and / or a polyurethane membrane.
One selected from the group consisting of aromatic polymer salts and / or sodium chloride, potassium chloride, disodium hydrogen phosphate, sodium dihydrogen phosphate, dipotassium hydrogen phosphate and potassium dihydrogen phosphate as dispersants in the aqueous phase. Contains the above inorganic salts,
Microcapsule pesticide composition.
Formula (I) Film thickness (nm) = (Membrane material weight / Core material weight) × (Core material density / Membrane material density) × (Medium volume diameter / 6) × 1000
[2] The microcapsule pesticide composition according to the above [1], wherein the ratio of the volume median diameter of the microcapsules to the film thickness of the microcapsules (volume median diameter / film thickness) is 100 to 2000.
[3] The microcapsule pesticide composition according to the above [1] or [2], wherein the aromatic polymer salt is at least one selected from the group consisting of lignin sulfonate, alkylnaphthalene sulfonate and styrene maleate. thing.
[4] The microcapsule pesticide composition according to any one of the above [1] to [3], wherein the content of the dispersant in the microcapsule pesticide composition is 0.01 to 5% by mass.
[5] The microcapsule pesticide composition according to any one of the above [1] to [4], wherein the active ingredient of the pesticide is an organophosphorus insecticide or a carbamate insecticide.
[6] The active ingredient of the pesticide is O, O-diethyl-O-2-isopropyl-6-methylpyrimidine-4-yl-phosphorothioate (generic name: diazinon), (RS) -O-2,4-dichlorophenyl = O. -Ethyl = S-propyl = phosphorodithioate (generic name: prothiophos), S-α-ethoxycarbonylbenzyl = O, O-dimethyl = phosphorodithioate (generic name: PAP, fentoate), or 2-sec- The microcapsule pesticide composition according to any one of the above [1] to [5], which is butylphenylmethylcarbamate (generic name: BPMC, phenocarb).

[7] A method for producing a microcapsule pesticide composition.
(1) (a) An oil phase containing a pesticide active ingredient and a polyisocyanate having an aromatic ring structure, and the content of the polyisocyanate having an aromatic ring structure is 3% by mass or less, and (b) an aromatic polymer as a dispersant. An aqueous phase containing a salt and / or an inorganic salt that is at least one selected from the group consisting of sodium chloride, potassium chloride, disodium hydrogen phosphate, sodium dihydrogen phosphate, dipotassium hydrogen phosphate and potassium dihydrogen phosphate. , The process of mixing,
(2) A step of dispersing the mixture to prepare an O / W emulsion.
(3) Step of preparing microcapsules by adding polyamine and / or polyol,
A method for producing a microcapsule pesticide composition.
[8] The microcapsule pesticide composition according to the above [7], wherein the volume median diameter of the microcapsules is 1 to 50 μm, and the film thickness of the microcapsules defined by the following formula (I) is 5 to 50 nm. Manufacturing method.
Formula (I) Film thickness (nm) = (Membrane material weight / Core material weight) × (Core material density / Membrane material density) × (Medium volume diameter / 6) × 1000
[9] The microcapsule pesticide composition according to the above [7] or [8], wherein the ratio of the medium volume diameter of the microcapsules to the film thickness of the microcapsules (medium volume diameter / film thickness) is 100 to 2000. Manufacturing method.
[10] The item according to any one of [7] to [9] above, wherein the aromatic polymer salt is at least one selected from the group consisting of lignin sulfonate, alkylnaphthalene sulfonate and styrene maleate. A method for producing a microcapsule pesticide composition.
[11] The method for producing a microcapsule pesticide composition according to any one of the above [7] to [10], wherein the content of the dispersant in the microcapsule pesticide composition is 0.01 to 5% by mass. ..

The microcapsule pesticide composition of the present invention is safe because the inclusion rate of the pesticide active ingredient is high, the strength of the film can be ensured from the microcapsules, and the pesticide active ingredient is not directly exposed to the sprayer. Sex is also ensured. In addition, the release of the active ingredient of the pesticide after spraying is rapid, and both the initial effect and the residual crop, which have been the problems of the microcapsule preparation, can be satisfied. That is, it is possible to provide a microcapsule pesticide preparation capable of achieving both high capsule encapsulation property at the time of spraying and immediate release property after spraying for the pesticide active ingredient.

The fate of the pesticide active ingredient of Example 21 and Comparative Example 9 is shown. The state of the microcapsules on the 0th day of Example 21 (electron microscope (400 times)) is shown. The state of the microcapsules (electron microscope (400 times)) on the third day of Example 21 is shown. The state of the microcapsules on the 7th day of Example 21 (electron microscope (400 times)) is shown. The state of the microcapsules on the 0th day of Comparative Example 9 (electron microscope (400 times)) is shown. The state of the microcapsules on the third day of Comparative Example 9 (electron microscope (400 times)) is shown. The state of the microcapsules on the 7th day of Comparative Example 9 (electron microscope (400 times)) is shown.

The microcapsule pesticide composition according to the present invention will be described below.
In the present invention, any compound for controlling pests having a water solubility of 1000 ppm or less at 20 ° C. as an active ingredient for pesticides can be applied without particular limitation. It is preferable to apply a compound used as an active ingredient of an insecticide. Specific examples of applicable pesticides include diadinone, prothiophos, cyanophos, fenitrothione, fenthion, pyrimiphosmethyl, isoxathione, chlorpyryphos, chlorpyriphosmethyl, malathion, fentate, dimethote, hosalon, metidation, acephate, trichlorfon, EPN, ethylthiomethon, profenophos. , Propetanphos, Hostiazeto, Imiciaphos, Kazusaphos and other organic phosphorus insecticides, Carbalyl, BPMC, MIPC, Carbosulfane, Benfracarb, Mesomil, Oxamil, Thiodicalb, Aranicalve and other carbamate insecticides, Pyrethrin, Areslin, Permethrin, Cipermethrin , Cihalothrin, Cifluthrin, Tralomethrin, Fenpropatrin, Bifenthrin, Fenvalerate, Flucitrinate, Fluvalinate, Acrinathrin, Cycloprothrin, Tefluthrin, Etofenprox, Silafluofen, Ciphenothrin, Phenotrin, Propulserin, Resmesrin, Alphames Pyrethroid insecticides such as phosphorus, flucythrinate, cyhalothrin, flumethrin, fenclusulin, and silaneophane, neonicotinoid insecticides such as imidacloprid, clothianidin, thiamethoxam, acetamiprid, thiacloprid, nitempyram, and other chromaphenozide, spinosad, spinosad Diflubenzron, Teflubenzron, Ruphenuron, Fluphenoxlon, Chlorfluazuron, Novalron, Tebuphenozide, methoxyphenozide, Syromadine, Pyriproxyfen, Buprofezin, Pymetrodin, Pyriflukinazone, Flonicamid, Pyridalyl, Chlorphenapyl, Torfenpyrado, Diafenthiurone Calve, Metaaldehyde, Tetradiphon, Propargit, Amitraz, Phenothiocarb, Hexiazoticus, Dienocle, Fempiroximate, Tebufenpyrad, Pyridaben, Pyrimidiphen, Clofenthedin, Etoxazole, Bufenazeto, Acequinosyl, Sienopyraphen, Piflubmid, Fluacrypyripyrim Mesifene, Siflumethofen, DD, DCIP, Methylisothiocianate, Carbam sodium salt, Nemadetin, BT, Frometkin, Hexaflumuron, Hi Examples thereof include dramethylnone, sulfullamin, fluxametamide, emamectin, repimectin, abamectin, milbemectin and the like. If there is no problem with mixing stability, two or more of these may be used.
Among them, an organic phosphorus insecticide is preferable in consideration of the significance of making a microcapsule formulation as a spray agent, and diazinon (chemical name: O, O-diethyl-O-2-isopropyl-6-methylpyrimidine-4-yl-) is preferable. Phosphorothioate), prothiophos ((RS) -O-2,4-dichlorophenyl = O-ethyl = S-propyl = phosphorodithioate), fentate, PAP (S-α-ethoxycarbonylbenzyl = O, O-dimethyl = phospho) Logithioate) or BPMC (phenocarb chemical name: 2-sec-butylphenylmethylcarbamate) is particularly preferable.
The content of the pesticide active ingredient is preferably 0.1 to 50 parts by mass, particularly preferably 1 to 50 parts by mass with respect to 100 parts by mass of the pesticide composition.

In the present invention, the microcapsules containing the pesticide active ingredient are not particularly limited, and microcapsules prepared by a known technique can be used. A preferred method for preparing microcapsules is a chemical preparation method, and particularly preferably, the method is prepared by an interfacial polymerization method because it is easy to produce, can be encapsulated in a short time, and the particle size can be easily controlled. Microcapsules can be mentioned.

The interfacial polymerization method is, for example, a method of polymerizing polyisocyanate and a polyol at a two-phase interface of an oil phase and an aqueous phase to form a film made of polyurethane, and a method of interfacially polymerizing polyisocyanate and polyamine to form a film made of polyurea. A method of forming or the like is used. In the present invention, the method for preparing microcapsules can be appropriately selected depending on the type of active ingredient, purpose of use, application, etc., but the interfacial polymerization method is particularly preferably used. In the present invention, microcapsules composed of a polyurea film and / or a polyurethane film and prepared by an interfacial polymerization method are preferable.
Hereinafter, the microcapsule pesticide composition according to the present application will be described in more detail based on a method for producing microcapsules prepared by an interfacial polymerization method.

In the interfacial polymerization method, an oil phase containing a pesticide active ingredient and an oil-soluble film-forming component is first prepared. In the present application, polyisocyanate is mentioned as an oil-soluble film-forming component, and in the present invention, polyisocyanate having an aromatic ring structure in the molecule is used.
Examples of the polyisocyanate having an aromatic ring structure include aromatic polyisocyanates such as diphenylmethane diisocyanate and toluene diisocyanate, aromatic polyisocyanates such as polymethylene polyphenyl isocyanate, xylylene diisocyanate, and tetramethylxylylene diisocyanate. .. Derivatives of these polyisocyanates, such as dimer, trimmer, biuret, allophanate, carbodiimide, uretdione, oxadiazine trione, and modified products of these polyisocyanates, such as low molecular weight polyols and polyethers such as trimethylolpropane. Examples thereof include a polyol-modified polyisocyanate obtained by reacting a high-molecular-weight polyol such as a polyol in advance. These oil-soluble film-forming components may be used alone or in combination of two or more.
Further, an alicyclic polyisocyanate such as an aliphatic polyisocyanate of hexamethylene diisocyanate, an isophorone diisocyanate, a hydrogenated xylylene diisocyanate, or a hydrogenated diphenylmethane diisocyanate may be used in combination.

The oil phase is when the polyisocyanate is a room temperature liquid and the pesticide active ingredient can be dissolved or dispersed therein, or when the pesticide active ingredient is a room temperature liquid and the polyisocyanate can be dissolved or dispersed therein. It can be prepared by blending these. Alternatively, for example, the oil phase can be prepared by dissolving or dispersing the pesticide active ingredient and the polyisocyanate using an organic solvent, if necessary.
The organic solvent is not particularly limited as long as it is an organic solvent capable of dissolving or dispersing the pesticide active ingredient and the polyisocyanate, and can be appropriately selected depending on the type of the active ingredient. It is preferable to use an aromatic organic solvent, and examples thereof include alkylbenzenes, alkylnaphthalene, alkylphenols, and phenylxysilylethane. More specifically, various commercially available organic solvents obtained from petroleum distillates, for example, Solbesso 100 (manufactured by ExxonMobil Co., Ltd.) Solbesso 150 (manufactured by ExxonMobil Co., Ltd.), Solbesso 200 (manufactured by ExxonMobil Co., Ltd.) , Solbesso 150ND (manufactured by ExxonMobil Co., Ltd.), Solbesso 200ND (manufactured by ExxonMobil Co., Ltd.), Swazol 1000 (manufactured by Maruzen Petroleum Co., Ltd.), Swazol 1500 (manufactured by Maruzen Petroleum Co., Ltd.), Swazol 1800 (manufactured by Maruzen Petroleum Co., Ltd.) Maruzen Petroleum Co., Ltd.), etc., and Solbesso 150ND is particularly preferable. These organic solvents may be used alone or in combination of two or more.

The mixing ratio of the pesticide active ingredient and the organic solvent is, for example, 25 to 100 parts by mass, preferably 50 to 95 parts by mass, and 0 to 0 to 95 parts by mass of the pesticide active ingredient with respect to 100 parts by mass of the total oil phase. The ratio is preferably 75 parts by mass, preferably 5 to 50 parts by mass.

The mixing ratio of the polyisocyanate having an aromatic ring structure can be in the range of 0.01 to 3 parts by mass with respect to 100 parts by mass of the oil phase, but it is mixed in the range of 0.02 to 2 parts by mass. It is preferable to do so. If the blending ratio of the polyisocyanate is large, the film of the obtained microcapsules may become too thick. On the other hand, if the blending ratio of the polyisocyanate is small, it may not be possible to form a film of microcapsules.

Other components that can be added to the oil phase include stabilizers, surfactants, plasticizers, gelling agents, etc. that are non-reactive with polyisocyanates in the oil phase and do not inhibit the interfacial polymerization reaction. Can be used.
Examples of the stabilizer include a quencher, a radical scavenger, an ultraviolet absorber, an antioxidant and the like. Quenchers include K-800 ((trade name), epoxidized soybean oil, manufactured by Takemoto Oil & Fat Co., Ltd.), epoxidized flaxseed oil, epoxidized fatty acid octyl, epoxidized fatty acid butyl, epoxidized nuka fatty acid methyl, and epoxidation. Examples thereof include rapeseed oil, and K-800 is particularly preferable. Examples of the radical scavenger include vitamin E, vitamin C, ubiquinol, uric acid, flavonoids, tannins, sesaminol, curcumin and the like. Examples of the ultraviolet absorber include benzotriazole-based ultraviolet absorbers and benzophenone-based ultraviolet absorbers. Examples of the antioxidant include phenolic antioxidants, phosphorus-based antioxidants, sulfur-based antioxidants and the like. Further, these stabilizers may be used by mixing two or more kinds at an arbitrary ratio.
The ratio of the stabilizer is preferably in the range of 0 to 10 parts by mass, and more preferably in the range of 0.1 to 5 parts by mass with respect to 100 parts by mass of the oil phase.

Surfactants include polyoxyethylene alkyl ether, polyoxyethylene alkylaryl ether, polyoxyethylene alkylphenol formalin condensate, polyoxyethylene castor oil derivative, polyoxyethylene fatty acid ester, higher fatty acid glycerin ester, polyoxyethylene fatty acid amide, and archi. Nonionic surfactants such as rollamide, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, polyoxyethylene polyoxypropylene block polymer, sucrose fatty acid ester, and polyglycerin fatty acid ester can be mentioned. Further, these surfactants may be used by mixing two or more kinds in an arbitrary ratio.
The ratio of the surfactant is preferably in the range of 0 to 10 parts by mass with respect to 100 parts by mass of the oil phase.

Examples of the plasticizer include phthalates, adipates, polyesters, phosphates, citric acids, sebacic acids, maleic acids and the like. Further, these plasticizers may be used by mixing two or more kinds at an arbitrary ratio.
The proportion of the plasticizer is preferably in the range of 0 to 10 parts by mass with respect to 100 parts by mass of the oil phase.
Examples of the gelling agent include waxes and resins, and examples thereof include hardened castor oil, 12-hydroxystearic acid, sorbitan fatty acid ester, polyglycerin fatty acid ester, stearic acid, stearyl alcohol, isopropyl myristate, glycol fatty acid ester, montan wax, and paraffin wax. , Candilla wax, carnauba wax, rice wax, beef fat hardening oil, beef fat extremely hardened oil, soybean hardened oil, honey wax, lanolin, whale wax, selecin, celac and other waxes. Further, these gelling agents may be used by mixing two or more kinds at an arbitrary ratio.
The ratio of the gelling agent is preferably in the range of 0 to 10 parts by mass with respect to 100 parts by mass of the oil phase.

In the preparation of microcapsules by the interfacial polymerization method, the oil phase prepared by mixing the oil phase components is mixed with the aqueous phase components, and the oil phase microdroplets are dispersed in the aqueous phase by stirring. It can be prepared by preparing an (O / W) emulsion and then taking a step of interfacial polymerization.
The aqueous phase is prepared by using a medium that is immiscible with the oil phase as a main component, and water is used as a medium and can be prepared by blending a dispersant in this aqueous medium. After producing the microcapsules, the dispersant also has a function of stabilizing the dispersion system so that sedimentation and agglutination do not occur in the microcapsule dispersion.
In the present invention, the aqueous phase is prepared as microcapsules using an aqueous phase containing an aromatic polymer salt or a specific inorganic salt as a dispersant, so that the aqueous phase contains the active ingredient of pesticides even though it is a thin-film microcapsule. A microcapsule dispersant having a high rate and excellent storage stability can be prepared. Further, in addition to the aromatic polymer salt and the specific inorganic salt, an aqueous phase containing a water-soluble polymer dispersant may be used.
In the microcapsule pesticide composition of the present invention, those applied as dispersants are aromatic polymer salts and / or sodium chloride, potassium chloride, disodium hydrogen phosphate, dipotassium hydrogen phosphate, sodium dihydrogen phosphate and One or more inorganic salts selected from the group consisting of potassium dihydrogen phosphate are used. The aromatic polymer salt and the inorganic salt may be used alone, or both may be used in combination.

Aromatic polymer salts are salts of polyanionic polymers that have an aromatic ring structure in the molecule. For example, lignin sulfonate, alkylnaphthalene sulfonate and styrene maleate can be mentioned. Alkali metal salts, alkaline earth metal salts or ammonium salts of these polyanionic polymers are used.
The aromatic polymer salt may be used alone as a dispersant, or may be used in combination with a water-soluble polymer dispersant described later.
The blending ratio of the aromatic polymer salt is preferably 0.1 parts by mass or more and 10 parts by mass or less, and more preferably 0.5 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the aqueous phase. The higher the concentration of the dispersant, the finer the volume median diameter can be obtained. Further, it is preferable to use 0.01 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the microcapsule pesticide composition according to the present application, and more preferably 0.01 part by mass or more and 5 parts by mass or less.

The water-soluble polymer dispersant that may be contained in the aqueous phase is used as a dispersion aid and is used to maintain the stabilization of the O / W dispersion system. Examples of the water-soluble polymer dispersant include polyvinyl alcohol, polyvinylpyrrolidone, vinylpyrrolidone vinyl acetate copolymer, methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, polyacrylic acid, polyacrylic acid metal salt, and the like. More preferred.
The mixing ratio of the water-soluble polymer dispersant is preferably 0.1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the aqueous phase, and more preferably 0.5 parts by mass or more and 10 parts by mass or less. The composition is preferably, more preferably 1 part by mass or less. Further, it is preferable to use 0.1 part by mass or more and 15 parts by mass or less with respect to 100 parts by mass of the microcapsule pesticide composition according to the present application, and more preferably 0.5 parts by mass or more and 10 parts by mass or less.

The inorganic salt is used in combination with a water-soluble polymer dispersant. The inorganic salt has a function of stabilizing the function of the water-soluble polymer dispersant and a function of preventing the components of the oil phase from being dissolved in the aqueous phase. Examples of the inorganic salt used in the present application are sodium chloride, potassium chloride, disodium hydrogen phosphate, dipotassium hydrogen phosphate, sodium dihydrogen phosphate, and potassium dihydrogen phosphate. These inorganic salts may be used alone or in combination of two or more. As a method of use, a predetermined amount of an inorganic salt is dissolved in an aqueous phase together with a water-soluble polymer dispersant. These dispersants also have a function of stabilizing the dispersion system so that sedimentation and agglutination do not occur in the microcapsule dispersion liquid after the microcapsules are produced.
The blending ratio of the inorganic salt is preferably 0.01 parts by mass or more and 20 parts by mass or less, and more preferably 0.5 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the aqueous phase. Further, it is preferable to use 0.01 part by mass or more and 15 parts by mass or less, more preferably 0.01 part by mass or more and 10 parts by mass or less, based on 100 parts by mass of the microcapsule pesticide composition according to the present application. The content is preferably 0.01 parts by mass or more and 5 parts by mass or less.

Examples of other optional components to be added to the aqueous phase include a defoaming agent, a pH adjuster, a surfactant, and the like, which are added in order to efficiently disperse the oil phase and the aqueous phase.
Silicone emulsion is generally used as the defoaming agent, and ((trade name), Antifoam E-20, manufactured by Kao Corporation) is particularly preferable. The blending ratio of the defoaming agent is preferably 10 parts by mass or less, and more preferably 5 parts by mass or less with respect to 100 parts by mass of the aqueous phase.
Acidity regulators include inorganic salts such as sodium hydroxide, potassium hydroxide, disodium hydrogen phosphate, sodium dihydrogen phosphate, dipotassium hydrogen phosphate, potassium dihydrogen phosphate, hydrochloric acid, sulfuric acid, acetic acid, formic acid, and citrus. Inorganic acids such as acids and phosphoric acids or organic acids can be used, and the proportion of the pH adjuster is preferably 10 parts by mass or less, more preferably 5 parts by mass or less with respect to 100 parts by mass of the aqueous phase. be.
Surfactants include polyoxyethylene alkyl ether, polyoxyethylene alkylaryl ether, polyoxyethylene alkylphenol formalin condensate, polyoxyethylene castor oil derivative, polyoxyethylene fatty acid ester, higher fatty acid glycerin ester, polyoxyethylene fatty acid amide, Nonionic surfactants such as alkylolamide, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, polyoxyethylene polyoxypropylene block polymer, sucrose fatty acid ester, polyglycerin fatty acid ester, polyoxyethylene alkyl ether sulfate Anionic surfactants such as salts, polyoxyethylene alkyl ether phosphates, polyoxyethylene alkylaryl ether sulfates, polyoxyethylene alkylaryl ether phosphates, alkyl sulfosuccinates, and betaine-type surfactants. Examples include amphoteric surfactants. Further, these surfactants may be used by mixing two or more kinds in an arbitrary ratio.

To mix the oil phase component with the water phase component, add the oil phase component to the water phase component, and at a constant temperature, use hiscotron, homomixer, dessolver, colloid mill, homogenizer, and super until the oil phase becomes fine droplets. Examples thereof include a method of stirring and dispersing with a disperser such as a sonic stirrer. At this time, the control for adjusting the particle size includes the model of the disperser, the stirring speed and the stirring time, the temperature of the aqueous phase and the oil phase, and the pH of the aqueous phase, and the optimum pH and temperature differ depending on the active ingredient to be dispersed. Specifically, the oil phase may be added while stirring the aqueous phase with a disperser under a constant temperature, and the stirring speed and stirring time may be controlled until the target volume medium diameter is reached. The volume median diameter when the oil phase is dispersed in the aqueous phase becomes a value close to the volume median diameter after the final interfacial polymerization reaction.
As a stirring model, Hiscotron (manufactured by Microtech Nithion Co., Ltd.) and T.I. K. Homo mixer (manufactured by Primix Corporation) and the like can be mentioned. The stirring speed is preferably in the range of 100 to 10000 rpm, more preferably 1000 to 8000 rpm. The stirring time is preferably in the range of 0.1 to 30 minutes, more preferably in the range of 0.5 to 15 minutes. By increasing the stirring speed, microcapsules having a small volume and a medium diameter can be prepared. Also, by lengthening the stirring time, microcapsules having a small volume and a medium diameter can be prepared.
The optimum temperature of the aqueous phase and the oil phase varies depending on the physical properties of the active ingredient to be dispersed, but is generally preferably in the range of 0.1 to 50 ° C, more preferably in the range of 1 to 30 ° C.
The optimum pH of the aqueous phase differs depending on the physical properties of the active ingredient to be dispersed, but in general, a pH that contributes to the stability of the active ingredient is preferable.

In the method for preparing microcapsules according to the present application by an interfacial polymerization method, an oil phase containing a pesticide active ingredient and a polyisocyanate having an aromatic ring structure is dispersed in an aqueous phase containing a dispersant, and then a water-soluble film-forming component is used. A method of dropping and mixing a certain curing agent can be mentioned.
The curing agent as a water-soluble film-forming component is a polyamine and / or a polyol that interfacially polymerizes by reacting with a polyisocyanate having an aromatic ring structure. That is, when polyamine is used as a curing agent, microcapsules of a polyurea film are prepared. On the other hand, when a polyol is used, polyurethane membrane microcapsules will be prepared. When both agents are used in combination, microcapsules made of a membrane material in which polyurea and polyurethane coexist are prepared.

Examples of the polyamine used as a curing agent include ethylenediamine, propylenediamine, hexamethylenediamine, diaminotoluene, phenylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, piperazine and the like, and alone or these. Two or more kinds of mixtures may be used. Ethylenediamine and diethylenetriamine are particularly preferable.

Examples of the polyol used as a curing agent include ethylene glycol, propanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, dipropylene glycol, cyclohexanedimethanol, and glycerin. , Trimethylol propane, polyethylene glycol, polypropylene glycol and the like, and may be used alone or in admixture of two or more of these. Diethylene glycol or propylene glycol is particularly preferred.

The curing agent is used as it is or as an aqueous solution thereof. In order to make the curing agent an aqueous solution, it is preferable to use it at a concentration of 50% by weight or less of the curing agent.
In the curing agent, the reactive groups of the film-forming component are approximately equal to the reactive groups of the polyisocyanate (for example, when polyisocyanate and polyamine are used, the equivalent ratio of isocyanate groups / amino groups is approximately 1). It is dropped until it becomes (ratio), and is subjected to the interfacial polymerization.
By dropping a curing agent onto an O / W emulsion in which fine oil droplets of an oil phase containing a pesticide active ingredient and a polyisocyanate having an aromatic ring structure are dispersed in the aqueous phase component, the curing agent and the polyisocyanate are formed. , Oil phase component Microcapsules can be obtained as a dispersion liquid in the aqueous phase by reacting at the interface between the fine oil droplets and the aqueous phase component to form a microcapsule film by the interfacial polymerization reaction and containing the active ingredient. can.
In order to promote this interfacial polymerization reaction, it is preferable to stir 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.
Examples of the stirrer used for mixing used when promoting the interfacial polymerization reaction include a chemical mixer and a three-one motor.

The microcapsule dispersion thus obtained may contain, if necessary, a thickener, an antifreeze agent, a preservative, a specific gravity adjusting agent, an osmotic pressure adjusting agent, a pH adjusting agent, a stabilizer, a coloring agent, a fragrance, and a surfactant. A known additive such as the above may be appropriately blended.
Examples of the thickener include natural polysaccharides such as zanthan gum, locust bean gum and xanthan gum, mineral substances such as magnesium aluminum silicate and bentonite, semi-synthetic polysaccharides such as sodium carboxymethyl cellulose salt, and synthetic water-soluble such as polyacrylic acid salt. Examples include sex polymers.
Examples of the antifreeze agent include urea and glycols such as propylene glycol, ethylene glycol, diethylene glycol, dipropylene glycol, polyethylene glycol and polypropylene glycol.
Examples of the preservative include Proxel GXL (S) ((trade name) 1,2-benzoisothiazolin-3-one, manufactured by Lonza Japan Co., Ltd.), 2-methyl-isothiazolin-3-one, formalin and the like. Proxel GXL (S) is particularly preferred.
Examples of the specific gravity adjusting agent include water-soluble salts such as sodium sulfate.
Examples of the osmotic pressure regulator include sugars such as mannitol, glucose and sorbitol, and inorganic substances such as sodium chloride and potassium chloride.
Examples of the pH adjuster include acids such as phosphoric acid, acetic acid, hydrochloric acid and citric acid, and bases such as sodium hydroxide, potassium hydroxide and ammonia.
Examples of the stabilizer include BHT and copper oxide.
Examples of the colorant include tartrazines such as Rhodamine B, Yellow No. 4, Blue No. 1, and Red No. 2, and various dyes.
Fragrances include esters such as ethyl acetoacetate, methyl anthranilate, ethyl silicate, organic acids such as caproic acid and silicate, alcohols such as geraniol, cinnamic alcohol, citral and decyl alcohol, vanillin, piperonal, etc. Examples thereof include aldehydes such as perylaldehyde and cinnamaldehyde, ketones such as marnitol and methyl β-naphthyl ketone, and menthols.
As a surfactant, various dispersants for the purpose of stabilizing dispersion can be used.
These can be used alone or in combination of two or more, but those that do not affect the microcapsule composition are preferable, and thickeners, preservatives, and glycols are particularly preferable. These additives can be used in the range of 0 to 30% by mass.

In the microcapsule preparation according to the present invention, the volume median diameter of the applied microcapsules has a great influence on the exertion of the pest control effect. The volume median diameter here represents the average particle size on a volume basis, and refers to the particle size at a point that is 50% of the cumulative curve when the cumulative curve is calculated with the total volume of the group as 100%.
In the microcapsule pesticide composition of the present invention, the volume median diameter of the microcapsules at the time of dispersion is determined by, for example, a commercially available laser diffraction type particle size distribution measuring device, specifically SALD2200 (manufactured by Shimadzu Corporation). It can be obtained by measuring the size of the medium volume diameter and its distribution state.
The microcapsule pesticide composition of the present invention has a volume median diameter of 1 to 50 μm. Since the nozzle diameter of the pesticide preparation used as a spraying agent is small at the time of spraying, it is desirable that the microcapsules have a small volume median diameter accordingly. More preferably, the median volume diameter is 4 to 45 μm, and even more preferably 10 to 30 μm.

In the microcapsule pesticide composition of the present invention, the film thickness of the microcapsules is 5 to 50 nm. The film thickness of the microcapsules is the film thickness calculated by the following formula (I) described on page 66 of the Agricultural Chemicals Formulation Guide (published by the Japan Plant Protection Association in 1997).
Formula (I) Film thickness (nm) = (Membrane material weight / Core material weight) × (Core material density / Membrane material density) × (Medium volume diameter / 6) × 1000
In the formula (I), the membrane substance is a component used in the reaction of the interfacial polymerization method, and is a polyisocyanate such as aromatic isocyanate and aliphatic isocyanate, and a curing agent such as polyamine and polyol. The core substance is a component other than the polyisocyanate contained in the oil phase, and specifically, is a solvent such as a pesticide active ingredient and an aromatic organic solvent. These weights are the total weights of each component, and these densities are the weighted average densities of the densities of each component. This defines the film thickness of the microcapsules according to the present invention.
In the present invention, the film thickness is preferably 1 to 50 nm, more preferably 5 to 40 nm, and even more preferably 10 to 30 nm.

Further, the microcapsule pesticide composition of the present invention preferably has a thin film thickness because it aims at rapid release of the active ingredient, and is 100 to 2000 according to the index indicated by (medium volume diameter / film thickness). Is preferable. This index shows the relationship between the median volume of microcapsules and the film thickness, which withstands the pressure at the time of spraying, exerts the most effective insecticidal effect, and rapidly disappears from the environment. In the present invention, (median volume diameter / film thickness) is preferably 200 to 1500, more preferably 400 to 1000.

The microcapsule pesticide composition of the present invention is usually diluted 10 to 10000 times with respect to the total weight of the active ingredient of the composition, and is directly treated by foliar spraying, soil mixing, soil irrigation treatment and the like. It is preferable to use water as the diluent. Alternatively, it is also possible to treat the soil as a microcapsule slurry as it is without removing the dispersion medium which is the aqueous phase component used for preparing the microcapsules without performing the dilution operation. Alternatively, the dispersion medium can be removed and the microcapsules can be used as a simple substance for soil treatment. Further, for example, it may be formulated into a known dosage form such as powder or granules.

The microcapsule pesticide composition of the present invention is mainly used as a pesticide for controlling pests generated in fruit trees, tea plants, vegetables and flowers. Pests to be controlled include peach stag beetle, pear spodoptera depras, apple spodoptera depras, spodoptera depras chinensis, wooly apple aphid, spodoptera depras larvae, worms, aphids, larvae of spodoptera deprasius, spodoptera depras chinensis , Umeshirokaigaramushi, Midorihimeyokobai, Kiboshimarutobimushi, Konaga, Kisujinomihamushi, Aomushi, Azamiuma, Negihamoguribae, Negikoga, Spider mites, Tentumushidamashi, Koganemushi larvae Examples include keratin, German cockroach, black cockroach, and nematodes. The microcapsule pesticide composition of the present invention can achieve both an initial effect immediately after spraying a pesticide and an appropriate residual effect thereafter.

The mechanism of action by which the microcapsule preparation exerts a control effect on pests is the first mechanism due to contact or absorption with the target pest due to leakage of the pesticide active ingredient due to physical destruction of the microcapsules, or micro. The second mechanism is due to contact with or absorption of the target pest by elution of the pesticide active ingredient from the capsule.
Regarding pest control, when the size of the pest itself is large, it is possible to destroy the microcapsules by exercising or feeding the target pest, and the effect of the first action mechanism is exhibited. On the other hand, when the size of the pest itself is small, the active ingredient eluted from the microcapsules comes into contact with the micropest and exerts its effect. From the viewpoint of ensuring the stability of the active ingredient and safety for workers at the time of spraying, it is desirable to use a formulation in which the elution of the active ingredient from the microcapsule membrane is suppressed. Therefore, the microcapsules containing the pest control active ingredient suppress the elution of the drug immediately after spraying, and the microcapsules disintegrate and elute due to light or drying and are easily taken into the body of the target pest or adhere to the body surface. As described above, it is efficient to prepare a microcapsule preparation having an appropriate medium diameter, and it is preferable to design such a microcapsule preparation.
Normally, in order to prolong the residual effect, the microcapsule preparation adjusts the residual effect by increasing the film thickness of the microcapsules, but if the residual effect is lengthened, the elution of the active ingredient decreases, so the initial effect Decreases. On the other hand, when the film thickness is reduced, the elution of the active ingredient of the pesticide increases, the content of the free ingredient of the active ingredient increases, and the initial effect is secured, but the strength of the microcapsules becomes weak and the stability decreases, and the formulation Problems such as an increase in the amount of the active ingredient outside the capsule inside and the breakage of the microcapsules due to the pressure at the time of spraying occur. Therefore, it is necessary to design a microcapsule formulation that enhances the insecticidal effect by increasing the stability of the microcapsules and increasing the amount of contact between the active ingredient eluted from the microcapsules and pests while setting the thickness of the microcapsules to be thin. There is.
In the microcapsule pesticide composition according to the present invention, by adding an aromatic polymer salt and / or a specific inorganic salt as a dispersant in the process of manufacturing microcapsules, even if the thickness of the microcapsules is thin, the capsule of the active ingredient is used. The inclusion rate is 95% or more. In addition, it is a preparation having excellent storage stability. Therefore, it is possible to surely secure the initial effect on the pests and solve the problem of drug exposure of the sprayer.

Hereinafter, the present invention will be described in more detail with reference to Examples.
As diazinon, one manufactured by Nippon Kayaku Co., Ltd. (purity 95.3%) was used. For prothiophos, a commercially available Tocthione wettable powder (manufactured by Arista Life Science Co., Ltd.) was purchased, extracted with ethyl acetate, concentrated, and purified (purity 94.4%). As the bulk material of Fentate, a commercially available Elsan wettable powder (manufactured by Nissan Chemical Industries, Ltd.) was purchased, extracted with hexane, concentrated, and purified (purity 91.7%). For BPMC, the stored product of unknown purity was used.

The prepared microcapsules were measured under the following analytical instruments and analytical conditions. Analytical instruments: Laser diffraction type particle size distribution measuring device 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: Flow cell method Cell material: Quartz glass Software: WingSALD-2200
Analytical sample: The prepared microcapsules were prepared by adding water so that the active ingredient had a concentration of 0.1 to 5% by weight and dispersing the prepared microcapsules.

The film thickness of the prepared microcapsules was calculated by the calculation method according to the following approximate formula (I).
Formula (I) Film thickness = (Membrane material weight / Core material weight) × (Core material density / Membrane material density) × (Medium volume diameter / 6)
Here, the following numerical values were used for each weight and density.
Film material weight = Polyisocyanate weight + Hardener weight Core material weight = Oil phase weight-Polyisocyanate weight Core material density = Density weighted average of the densities of oil phase components excluding polyisocyanate Film material density = Polyisocyanate and hardener The following density (specific gravity) values were used to calculate the film thickness of the density example in which the densities were weighted and averaged.
Diazinon: 1.117
Prothiophos: 1.310
Fentate: 1.226
BPMC: 1.10
MR-400: 1.240
MR-100: 1.231
TMDI: 1.020
Solvesso150ND: 0.886
Solvesso 150: 0.895
JX Normal Paraffin: 0.750
Diethylenetriamine: 0.955
Ethylenediamine: 0.960
Diethylene glycol: 1.118
Propylene glycol: 1.038

The encapsulation rate of the active ingredient in the prepared microcapsules is determined by measuring the content of the active ingredient in the formulation and the amount of free ingredient of the active ingredient outside the capsule by the analysis method shown below. The amount of the active ingredient in the capsule was calculated by subtracting the amount of the free ingredient of the active ingredient of ..
As a method for analyzing the content of the active ingredient in the formulation, weigh about 1 g of the microcapsule composition, add 100 mL of the internal standard substance and acetonitrile, shake at a rate of 300 times / min for 20 minutes, and add 1 mL of the supernatant to 0. It was filtered through a .45 μm syringe filter to prepare a sample solution for content analysis.
The sample solution was analyzed by high performance liquid chromatography, and the active ingredient content was determined by the internal standard method.
As a method for analyzing the amount of free component of the active ingredient outside the capsule, about 1 g of the microcapsule composition is weighed, an internal standard substance and 50 mL of toluene or hexane are added, and the mixture is shaken at a rate of 300 times / minute for 5 minutes to make a supernatant. 1 mL was mixed with 9 mL of acetonitrile to prepare a sample solution for analyzing the amount of free components. The sample solution was analyzed by high performance liquid chromatography, the amount of free component of the active ingredient was determined by the internal standard method, and then the encapsulation rate of the active ingredient was calculated from the following formula (II).
Formula (II) Capsule encapsulation rate (%) = (((microcapsule composition amount x active ingredient content) -free ingredient amount) / (microcapsule composition amount x active ingredient content)) x 100

Example 1
(2-Isopropyl-4-methylpyrimidyl-6) -diethylthiophosphate (generic name: diazinone, purity 95.6%) in 35.9 parts by mass, MR-400 ((trade name), poly) as an oil-soluble film-forming component. Methylenepolyphenylpolyisocyanate, manufactured by Toso Co., Ltd., 0.12 parts by mass, and TMDI ((trade name), trimethylhexamethylene diisocyanate, manufactured by Ebony Japan Co., Ltd.), 0.12 parts by mass, K-800 (((trade name)). (Product name), epoxidized soybean oil, and Takemoto Oil & Fat Co., Ltd.) 2.5 parts by mass were added and mixed uniformly to prepare an oil phase component.
In another container, 6.0 parts by mass of a 5% by mass aqueous solution of PVA-217 ((trade name), polyvinyl alcohol, manufactured by Kuraray Co., Ltd.), Sun Extract P-252 ((trade name), lignin sulfonate, lignin sulfonate, 0.5 parts by mass of Nippon Paper Industries Co., Ltd. and 34.88 parts by mass of tap water were added to prepare an aqueous phase component.
Put the oil phase component and the aqueous phase component in a 300 mL separable flask, use Hiscotron (manufactured by Microtech Nithion Co., Ltd.), stir for 2 minutes at a rotation speed of 2500 rpm, and then stir for 3 minutes at 7000 rpm to stir the oil phase component. Was dispersed to prepare an O / W type emulsion. A mixed solution of 0.08 part by mass of diethylenetriamine ((reagent), manufactured by Huntsman Japan Co., Ltd.) and 0.6 part by mass of tap water was added to this as a water-soluble film-forming component, and the mixture was reacted at 60 ° C. for 3 hours under stirring. , Microcapsule-containing solution was prepared.
In addition, as a settling inhibitor, 10 parts by mass of propylene glycol ((trade name), manufactured by ADEKA Corporation), 0.1 part by mass of Roadpole 23 ((trade name), xanthan gum, manufactured by Solvay Nikka Co., Ltd.), Theoras RC591 ((trade name), carboxymethyl cellulose, manufactured by Asahi Kasei Co., Ltd.), 0.25 parts by mass, Proxel GXL (S) ((trade name), bactericide, manufactured by Lonza Japan Co., Ltd.) by 0.2 mass A part and 8.75 parts by mass of tap water were added and mixed uniformly to obtain a dispersion containing pest control microcapsules having a diadinone content of 34% by mass.
The measured value of the median volume of the obtained microcapsules was 16.4 μm. The calculated value of the film thickness of the microcapsules was 23 nm. The capsule inclusion rate was 96.4%.

Example 2
All operations were carried out in the same manner except that the aqueous phase sun extract P-252 in Example 1 was changed to 0.02 parts by mass and tap water was changed to 35.36 parts by mass. A dispersion containing capsules was obtained.
The measured value of the median volume of the obtained microcapsules was 21.6 μm. The calculated value of the film thickness of the microcapsules was 31 nm. The pessel inclusion rate was 97.1%.

Example 3
All operations were carried out in the same manner except that the aqueous phase sun extract P-252 in Example 1 was changed to 1.0 part by mass and tap water was changed to 34.38 parts by mass. A dispersion containing capsules was obtained.
The measured value of the median volume of the obtained microcapsules was 24.5 μm. The calculated value of the film thickness of the microcapsules was 35 nm. The pessel inclusion rate was 97.7%.

Example 4
All operations were carried out in the same manner except that the aqueous phase sun extract P-252 in Example 1 was changed to 2.0 parts by mass and tap water was changed to 33.38 parts by mass. A dispersion containing capsules was obtained.
The measured value of the median volume of the obtained microcapsules was 17.4 μm. The calculated value of the film thickness of the microcapsules was 25 nm. The pessel inclusion rate was 96.8%.

Example 5
0.5 parts by mass of Sun Extract P-252 of the aqueous phase in Example 1 was added to 0.5 parts by mass of Molwet D-425 POWDER ((trade name), alkylnaphthalene sulfonate, manufactured by Lion Specialty Chemicals Co., Ltd.). All operations were carried out in the same manner except that 10.0 parts by mass of propylene glycol as an anti-settling agent was changed to 5.0 and 8.75 parts by mass of tap water was changed to 13.75 parts by mass. A dispersion containing microcapsules for use was obtained.
The measured value of the median volume of the obtained microcapsules was 26.2 μm. The calculated value of the film thickness of the microcapsules was 37 nm. The pessel inclusion rate was 96.7%.

Example 6
All operations were carried out in the same manner except that 0.02 parts by mass of the aqueous phase sun extract P-252 in Example 2 was changed to 0.02 parts by mass of Molwet D-425 POWDER, and the microcapsules for pest control having a diazinon content of 34% by weight were operated in the same manner. A dispersion containing the above was obtained.
The measured value of the median volume of the obtained microcapsules was 22.4 μm. The calculated value of the film thickness of the microcapsules was 32 nm. The pessel inclusion rate was 97.5%.

Example 7
34.88 parts by mass of tap water in the aqueous phase in Example 1 was added to 33.38 parts by mass, and 2.0 parts by mass of sodium chloride was added to the aqueous phase, while 0.5 parts by mass of Sun Extract P-252 was added to 0 parts by mass. All the same operations were carried out except that the parts were changed to parts, and a dispersion containing pest control microcapsules having a diazinone content of 34% by mass was obtained.
The measured value of the median volume of the obtained microcapsules was 20.3 μm. The calculated value of the film thickness of the microcapsules was 29 nm. The capsule inclusion rate was 97.8%.

Example 8
A dispersion containing a pest control microcapsule having a diazinon content of 34% by mass by operating in the same manner except that 2.0 parts by mass of sodium chloride in the aqueous phase in Example 7 was changed to 2.0 parts by mass of potassium chloride. Got
The measured value of the median volume of the obtained microcapsules was 23.4 μm. The calculated value of the film thickness of the microcapsules was 33 nm. The capsule inclusion rate was 97.7%.

Example 9
All the same except that 1.0 part by mass of Sun Extract P-252 of the aqueous phase in Example 3 was changed to 1.0 part by mass of Demol MS ((trade name), alkylnaphthalene sulfonate, manufactured by Kao Co., Ltd.). To obtain a dispersion containing pest control microcapsules having a diazinone content of 34% by mass.
The measured value of the median volume of the obtained microcapsules was 19.6 μm. The calculated value of the film thickness of the microcapsules was 28 nm. The capsule inclusion rate was 96.7%.

Example 10
Except that 1.0 part by mass of the aqueous phase sun extract P-252 in Example 3 was changed to 1.0 part by mass of Srz-402K ((trade name), alkylstyrene maleate, manufactured by Taoka Chemical Co., Ltd.). All were operated in the same manner to obtain a dispersion containing pest control microcapsules having a diazinon content of 34% by mass.
The measured value of the median volume of the obtained microcapsules was 21.7 μm. The calculated value of the film thickness of the microcapsules was 31 nm. The capsule inclusion rate was 95.5%.

Example 11
All the same except that 1.0 part by mass of Sun Extract P-252 of the aqueous phase in Example 3 was changed to 1.0 part by mass of Vanillex N ((trade name), lignin sulfonate, manufactured by Nippon Paper Industries, Ltd.). To obtain a dispersion containing microcapsules for pest control having a diazinon content of 34% by mass.
The measured value of the median volume of the obtained microcapsules was 20.7 μm. The calculated value of the film thickness of the microcapsules was 29 nm. The capsule inclusion rate was 98.3%.

Example 12
All were operated in the same manner except that 1.0 part by mass of Vanillex N in the aqueous phase in Example 11 was changed to 0.5 part by mass and 34.38 parts by mass of tap water was changed to 34.88 parts by mass, and the diazinone content was 34. A dispersion containing% by weight of pest control microcapsules was obtained.
The measured value of the median volume of the obtained microcapsules was 21.7 μm. The calculated value of the film thickness of the microcapsules was 31 nm. The capsule inclusion rate was 98.2%.

Example 13
All were operated in the same manner except that 1.0 part by mass of Vanillex N of the aqueous phase in Example 11 was changed to 3.0 parts by mass and 34.38 parts by mass of tap water was changed to 32.38 parts by mass, and the diazinone content was 34. A dispersion containing% by weight of pest control microcapsules was obtained.
The measured value of the median volume of the obtained microcapsules was 20.0 μm. The calculated value of the film thickness of the microcapsules was 28 nm. The capsule inclusion rate was 96.5%.

Example 14
In Example 3, 34.38 parts by mass of tap water in the aqueous phase was added to 32.38 parts by mass, and 2.0 parts by mass of sodium chloride was added to the aqueous phase. A dispersion containing microcapsules for controlling pests was obtained.
The measured value of the median volume of the obtained microcapsules was 22.9 μm. The calculated value of the film thickness of the microcapsules was 32 nm. The capsule inclusion rate was 98.8%.

Example 15
In Example 14, 0.12 parts by mass of MR-400 in the oil phase was 0.06 parts by mass, 0.12 parts by mass of TMDI was 0.06 parts by mass, and 32.38 parts by mass of tap water in the aqueous phase was 32. All operations were carried out in the same manner except that 0.08 parts by mass of the curing agent diethylenetriamine was changed to 0.04 parts by mass in 54 parts by mass to obtain a dispersion containing microcapsules for pest control having a diadinone content of 34% by mass. rice field.
The measured value of the median volume of the obtained macrocapsules was 22.6 μm. The calculated value of the film thickness of the microcapsules was 16 nm. The capsule inclusion rate was 97.2%.

Example 16
In Example 15, 32.54 parts by mass of tap water in the aqueous phase was changed to 30.54 parts by mass, and 2.0 parts by mass of sodium chloride was changed to 4.0 parts by mass. A dispersion containing% by weight of pest control microcapsules was obtained.
The measured value of the median volume of the obtained microcapsules was 22.8 μm. The calculated value of the film thickness of the microcapsules was 16 nm. The capsule inclusion rate was 95.5%.

Example 17
Pests having a diazinon content of 34% by mass were all operated in the same manner except that 34.38 parts by mass of tap water in the aqueous phase in Example 11 was changed to 31.38 parts by mass and sodium chloride was changed to 3.0 parts by mass. A dispersion containing control microcapsules was obtained.
The measured value of the median volume of the obtained microcapsules was 23.5 μm. The calculated value of the film thickness of the microcapsules was 33 nm. The capsule inclusion rate was 98.6%.

Example 18
MR-400 ((trade name), poly) as an oil-soluble film-forming component in 31.59 parts by mass of (2-isopropyl-4-methylpyrimidyl-6) -diethylthiophosphate (generic name: diazinone, purity 95.6%) Methylenepolyphenylpolyisocyanate, manufactured by Toso Co., Ltd., 0.12 parts by mass, and TMDI ((trade name), trimethylhexamethylene diisocyanate, manufactured by Ebony Japan Co., Ltd.), 0.12 parts by mass, K-800 ((commodity name)) Name), epoxidized soybean oil, Takemoto Oil & Fat Co., Ltd.) 1.0 parts by mass, Solbesso 150 ((trade name), Exxon Mobile Co., Ltd.) 10.0 parts, mix uniformly and mix oil phase Ingredients were prepared.
In another container, 6.0 parts by mass of a 5% by mass aqueous solution of PVA-217 ((trade name), polyvinyl alcohol, manufactured by Kuraray Co., Ltd.), Sun Extract P-252 ((trade name), lignin sulfonate, lignin sulfonate, An aqueous phase component was prepared by adding 1.0 part by mass of Nippon Paper Co., Ltd., 2.5 parts by mass of sodium chloride, and 33.44 parts by mass of tap water.
Put the oil phase component and the aqueous phase component in a 300 mL separable flask, and use Hiscotron (manufactured by Microtech Nithion Co., Ltd.) to stir at 2500 rpm for 3 minutes and then at 5000 rpm for 4 minutes. The phase components were dispersed to prepare an O / W type emulsion. A mixed solution of 0.08 part by mass of diethylenetriamine and 0.6 part by mass of tap water was added thereto as a water-soluble film-forming component, and the mixture was reacted at 60 ° C. for 3 hours under stirring to prepare a microcapsule-containing liquid.
In addition, as a settling inhibitor, 5 parts by mass of propylene glycol ((trade name), manufactured by ADEKA Corporation), 0.1 part by mass of Roadpole 23 ((trade name), xanthan gum, manufactured by Solvay Nikka Co., Ltd.), Theoras RC591 ((trade name), carboxymethyl cellulose, manufactured by Asahi Kasei Co., Ltd.), 0.25 parts by mass, Proxel GXL (S) ((trade name), bactericide, manufactured by Lonza Japan Co., Ltd.) by 0.2 mass A part and 8 parts by mass of tap water were added and mixed uniformly to obtain a dispersion containing pest control microcapsules having a diadinone content of 30% by mass.
The measured value of the median volume of the obtained microcapsules was 19.9 μm. The calculated value of the film thickness of the microcapsules was 24 nm. The capsule inclusion rate was 98.6%.

Example 19
In Example 18, 0.12 parts by mass of MR-400 of the oil phase component was 0.09 parts by mass, 0.12 parts by mass of TMDI was 0.09 parts by mass, and 33.44 parts by mass of tap water in the aqueous phase was 33 parts. The same procedure was applied to .52 parts by mass except that 0.08 parts by mass of the curing agent diethylenetriamine was changed to 0.06 parts by mass, and a dispersion containing a pest control microcapsule having a diadinone content of 30% by mass was added. Obtained.
The measured value of the median volume of the obtained microcapsules was 17.2 μm. The calculated value of the film thickness of the microcapsules was 16 nm. The capsule inclusion rate was 96.9%.

Example 20
All operations were carried out in the same manner except that 2.5 parts by mass of sodium chloride in the aqueous phase in Example 19 was changed to 2.5 parts by mass of disodium hydrogen phosphate, and a pest control microcapsule having a diazinone content of 30% by mass was contained. A dispersion was obtained.
The measured value of the median volume of the obtained microcapsules was 20.1 μm. The calculated value of the film thickness of the microcapsules was 18 nm. The capsule inclusion rate was 98.0%.

Example 21
MR-400 0.12 parts by mass of the oil phase component in Example 18 was added to MR-100 ((trade name), polymethylene polyphenyl polyisocyanate, manufactured by Toso Co., Ltd.) to 0.30 parts by mass, and TMDI 0. 12 parts by mass is 0 parts by mass, 10 parts by mass of Solbesso 150 is 8 parts by mass of Solbesso 150ND, 33.44 parts by mass of tap water in the aqueous phase is 35.86 parts by mass, and 2.5 parts by mass of sodium chloride is 2. All operations were carried out in the same manner except that 0.08 parts by mass of the curing agent diethylenetriamine was added to 0 parts by mass and 0.05 parts by mass of propylene glycol was added to the curing agent. A dispersion containing control microcapsules was obtained.
The measured value of the median volume of the obtained microcapsules was 21.8 μm. The calculated value of the film thickness of the microcapsules was 33 nm. The capsule inclusion rate was 98.8%.

Example 22
In Example 18, 0.12 parts by mass of MR-400 of the oil phase component was 0.36 parts by mass, 0.12 parts of TMDI was 0.36 parts by mass, and 10 parts by mass of Solbesso 150 was 10 parts by mass of Solbesso 150ND. Except that 6 g of 5% PVA aqueous solution in the aqueous phase was changed to 12 g, 33.44 parts by mass of tap water was changed to 26.8 parts by mass, and 0.08 parts by mass of the curing agent diethylenetriamine was changed to 0.24 parts by mass. The same procedure was carried out to obtain a dispersion containing pest control microcapsules having a diazinone content of 30% by mass.
The measured value of the median volume of the obtained microcapsules was 9.2 μm. The calculated value of the film thickness of the microcapsules was 34 nm. The capsule inclusion rate was 99.0%.

Example 23
MR-400 0.12 parts by mass, TMDI 0.12 parts by mass, 0.18 parts by mass, Solbesso 150, 10 parts by mass, Solbesso 150ND, 10 parts by mass, in Example 18 In addition, 33.44 parts by mass of tap water in the aqueous phase was changed to 33.28 parts by mass, and 0.08 parts by mass of the curing agent diethylenetriamine was changed to 0.12 parts by mass. A dispersion containing% by weight of pest control microcapsules was obtained.
The measured value of the median volume of the obtained microcapsules was 19.4 μm. The calculated value of the film thickness of the microcapsules was 36 nm. The capsule inclusion rate was 99.1%.

Example 24
In Example 18, 0.12 parts by mass of MR-400 of the oil phase component was 0.09 parts by mass, 0.12 parts of TMDI was 0.09 parts by mass, and 10 parts by mass of Solbesso 150 was 10 parts by mass of Solbesso 150ND. In addition, 33.4 parts by mass of tap water in the aqueous phase was changed to 33.52 parts by mass, and 0.08 parts by mass of the curing agent diethylenetriamine was changed to 0.06 parts by mass. A dispersion containing% by weight of pest control microcapsules was obtained.
The measured value of the median volume of the obtained microcapsules was 40.7 μm. The calculated value of the film thickness of the microcapsules was 37 nm. The capsule inclusion rate was 99.3%.

Example 25
In Example 18, 0.12 parts by mass of MR-400 of the oil phase component was 0.72 parts by mass, 0.12 parts of TMDI was 0.72 parts by mass, and 10 parts by mass of Solbesso 150 was 10 parts by mass of Solbesso 150ND. In addition, 1.0 part by mass of Sun Extract P-252 in the aqueous phase was added to 2.0 parts by mass, 6 g of the 5% PVA aqueous solution in the aqueous phase was added to 12 g, and 33.44 parts by mass of tap water was added to 27.7 parts by mass. All were operated in the same manner except that 0.08 parts by mass of diethylenetriamine as a curing agent was changed to 0.48 parts by mass and 8.0 parts by mass of tap water as an anti-settlement agent was changed to 3.0 parts by mass. A dispersion containing% pest control microcapsules was obtained.
The measured value of the median volume of the obtained microcapsules was 4.5 μm. The calculated value of the film thickness of the microcapsules was 33 nm. The capsule inclusion rate was 98.2%.

Example 26
In Example 21, 0.3 parts by mass of MR-100 of the oil phase component was 0.3 parts by mass of MR-400, 0.05 parts by weight of diethylenetriamine as a curing agent was 0 parts by mass, and 0.05 parts by mass of propylene glycol was 0 parts by mass. All operations were carried out in the same manner except that the content was changed to 1 part by mass to obtain a dispersion containing microcapsules for pest control having a diazinone content of 30% by weight.
The measured value of the median volume of the obtained microcapsules was 19.6 μm. The calculated value of the film thickness of the microcapsules was 29 nm. The capsule inclusion rate was 96.8%.

Example 27
MR-400 ((trade name)) as an oil-soluble film-forming component in 21.45 parts by mass of (RS) -O-2,4-dichlorophenyl = O-ethyl = S-propyl = phosphorodithioate (generic name: prothiophos) ), Polymethylene polyphenyl polyisocyanate, manufactured by Tosoh Corporation) 0.13 parts by mass was added and mixed uniformly to prepare an oil phase component.
In a separate container, 1.8 parts by mass of an 8.3 wt% aqueous solution of PVA-217 ((trade name), polyvinyl alcohol, manufactured by Kuraray Co., Ltd.), Morwet D-425 Water ((trade name), alkylnaphthalene sulfonate). , Lion Specialty Chemicals Co., Ltd.) 1.0 part by mass and 19.63 parts by mass of tap water were added to prepare an aqueous phase component.
Put the oil phase component and the aqueous phase component in a 300 mL separable flask, and use Hiscotron (manufactured by Microtech Nithion Co., Ltd.) to stir at a rotation speed of 2000 rpm for 2 minutes and then at 7500 rpm for 2 minutes to disperse the oil phase component. Then, an O / W type emulsion was prepared. A mixed solution of 0.04 parts by mass of ethylenediamine ((reagent), manufactured by Wako Pure Chemical Industries, Ltd.) and 0.3 parts by mass of tap water was added to this as a water-soluble film-forming component, and reacted at 60 ° C. for 3 hours under stirring. To prepare a microcapsule-containing solution.
In addition, as a settling inhibitor, 5 parts by mass of propylene glycol ((trade name), manufactured by ADEKA Corporation), 0.1 part by mass of Roadpole 23 ((trade name), xanthan gum, manufactured by Solvay Nikka Co., Ltd.), Kunipia F ((trade name), bentonite, manufactured by Kunimine Kogyo Co., Ltd.), 0.2 parts by mass, Proxel GXL (S) ((trade name), bactericide, manufactured by Lonza Japan Co., Ltd.) 0.15 mass Partially added and mixed uniformly to obtain a dispersion containing pest control microcapsules having a prothiophos content of 40% by mass.
The measured value of the volume median diameter of the obtained microcapsules was 10.5 μm. The calculated value of the film thickness of the microcapsules was 15 nm. The capsule inclusion rate was 99.5%.

Example 28
S-α-ethoxycarbonylbenzyl = O, O-dimethyl = phosphorodithioate (generic name: PAP, fentoate) 21.81 parts by mass, MR-400 ((trade name), polymethylene) as an oil-soluble film-forming component Polyphenyl polyisocyanate, manufactured by Tosoh Corporation, 0.075 parts by mass was added and mixed uniformly to prepare an oil phase component.
In a separate container, 3.0 parts by mass of a 5% aqueous solution of PVA-217 ((trade name), polyvinyl alcohol, manufactured by Kuraray Co., Ltd.), Sun Extract P-252 ((trade name), lignin sulfonate, Nippon Paper Co., Ltd.) (Manufactured by Co., Ltd.) 0.5 parts by mass, sodium chloride 1.25 parts by mass, tap water 15.715 parts by mass, antifoam E-20 ((trade name), silicone emulsion, 0.05 parts by mass) And prepared the aqueous phase component.
Put the oil phase component and the aqueous phase component in a 300 mL separable flask, and use Hiscotron (manufactured by Microtech Nithion Co., Ltd.) to stir for 2 minutes at a rotation speed of 2500 rpm and then for 2 minutes at a rotation speed of 6000 rpm to obtain the oil. The phase components were dispersed to prepare an O / W type emulsion. A mixed solution of 0.025 parts by mass of diethylenetriamine and 0.3 parts by mass of tap water 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.
In addition, 3.5 parts by mass of propylene glycol ((trade name), manufactured by ADEKA Corporation) and 0.05 mass by load pole 23 ((trade name), xanthan gum, manufactured by Solvay Nikka Co., Ltd.) as anti-settlement agents. , Theoras RC591 ((trade name), carboxymethyl cellulose, manufactured by Asahi Kasei Co., Ltd.), 0.125 parts by mass, Proxel GXL (S) ((trade name), bactericide, manufactured by Lonza Japan Co., Ltd.). 1 part by mass and 3.5 parts by mass of tap water were added and mixed uniformly to obtain a dispersion containing pest control microcapsules having a fentoate content of 40% by mass.
The measured value of the median volume of the obtained microcapsules was 26.5 μm. The calculated value of the film thickness of the microcapsules was 21 nm. The capsule inclusion rate was 98.5%.

Example 29
2-sec-Butylphenyl-N-methylcarbamate (generic name: BPMC, phenocarb) in 15.5 parts by mass, MR-400 ((trade name), polymethylenepolyphenylpolyisocyanate, Tosoh) as an oil-soluble film-forming component 0.18 parts by mass of (manufactured by Co., Ltd.) and 5.0 parts of Solbesso ((trade name), manufactured by Exxon Mobile Co., Ltd.) were added and mixed uniformly to prepare an oil phase component.
In another container, 3.6 parts by mass of a 5% by mass aqueous solution of PVA-217 ((trade name), polyvinyl alcohol, manufactured by Kuraray Co., Ltd.), Sun Extract P-252 ((trade name), lignin sulfonate, lignin sulfonate, An aqueous phase component was prepared by adding 0.6 parts by mass, 1.5 parts by mass of sodium chloride, and 15.46 parts by mass of tap water (manufactured by Nippon Paper Co., Ltd.).
Put the oil phase component and the aqueous phase component in a 300 mL separable flask, and stir with Hiscotron (manufactured by Microtech Nithion Co., Ltd.) at a rotation speed of 2500 rpm for 2 minutes and then at a rotation speed of 4000 to 8000 rpm for 3 minutes. The oil phase component was dispersed to prepare an O / W type emulsion. A mixed solution of 0.06 part by mass of diethylenetriamine and 0.3 part by mass of tap water was added thereto as a water-soluble film-forming component, and the mixture was reacted at 60 ° C. for 3 hours under stirring to prepare a microcapsule-containing liquid.
In addition, 2.5 parts by mass of propylene glycol ((trade name), manufactured by ADEKA Corporation) and 0.1 mass of load pole 23 ((trade name), xanthan gum, manufactured by Solvay Nikka Co., Ltd.) as anti-settlement agents. , Theoras RC591 ((trade name), carboxymethyl cellulose, manufactured by Asahi Kasei Co., Ltd.), 0.1 part by mass, Proxel GXL (S) ((trade name), bactericide, manufactured by Lonza Japan Co., Ltd.). 1 part by mass and 5 parts by mass of tap water were added and mixed uniformly to obtain a dispersion containing pest control microcapsules having a BPMC content of 30% by mass.
The measured value of the median volume of the obtained microcapsules was 29.0 μm. The calculated value of the film thickness of the microcapsules was 51 nm. The capsule inclusion rate was 95.3%.

Comparative Example 1
MR-400 ((trade name), polymethylene polyphenyl polyisocyanate) as an oil-soluble film-forming component in 35.9 parts by mass of (2-isopropyl-4-methylpyrimidyl-6) -diethylthiophosphate (generic name: diazinone), Tosoh Co., Ltd.) 0.12 parts by mass, TMDI ((trade name), trimethylhexamethylene diisocyanate, Ebonic Japan Co., Ltd.) 0.12 parts by mass, K-800 ((trade name), large epoxidation Soybean oil and Takemoto Oil & Fat Co., Ltd. (manufactured by Takemoto Oil & Fat Co., Ltd.) added 2.5 parts by mass and mixed uniformly to prepare an oil phase component.
In another container, 6.0 parts by mass of a 5% by mass aqueous solution of PVA-217 ((trade name), polyvinyl alcohol, manufactured by Kuraray Co., Ltd.) and 35.38 parts by mass of tap water were placed to prepare an aqueous phase component. ..
Put the oil phase component and the aqueous phase component in a 300 mL separable flask, and stir for 2 minutes at a rotation speed of 2500 rpm using Hiscotron (manufactured by Microtech Nithion Co., Ltd.), and then stir for 2 minutes at a rotation speed of 5000 rpm. The oil phase component was dispersed to prepare an O / W type emulsion. A mixed solution of 0.08 part by mass of diethylenetriamine ((trade name), manufactured by Huntsman Japan Co., Ltd.) and 0.6 part by mass of tap water was added to this as a water-soluble film-forming component, and the mixture was reacted at 60 ° C. for 3 hours under stirring. To prepare a microcapsule-containing solution.
In addition, as a settling inhibitor, 10 parts by mass of propylene glycol ((trade name), manufactured by ADEKA Corporation), 0.1 part by mass of Roadpole 23 ((trade name), xanthan gum, manufactured by Solvay Nikka Co., Ltd.), Abyssel RC591 ((trade name), carboxymethyl cellulose, manufactured by Asahi Kasei Co., Ltd.), 0.25 parts by mass, Proxel GXL (S) ((trade name), bactericide, manufactured by Lonza Japan Co., Ltd.) by 0.2 mass A part and 8.75 parts by mass of tap water were added and mixed uniformly to obtain a dispersion containing pest control microcapsules having a diadinone content of 34% by mass.
The measured value of the median volume of the obtained microcapsules was 18.2 μm. The calculated value of the film thickness of the microcapsules was 26 nm. The capsule inclusion rate was 89.7%.

Comparative Example 2
2.0 parts by mass of New Calgen WG-5 ((trade name), sodium polycarboxylic acid, manufactured by Takemoto Yushi Co., Ltd.) was added to the aqueous phase of Comparative Example 1, and 0.4 parts by mass of Antiform E-20 was added. When all the operations were performed in the same manner except that tap water was changed to 32.98 parts by mass and 0.08 parts by mass of the curing agent diethylenetriamine was changed to 0.08 parts by mass of ethylenediamine, the microcapsule dispersion liquid solidified during the reaction. I couldn't get it.

Comparative Example 3
All were operated in the same manner except that 0.08 part by mass of diethylenetriamine of Comparative Example 1 was changed to 0.08 part by mass of diethylene glycol ((reagent), manufactured by Wako Pure Chemical Industries, Ltd.), and the diazinon content was 34% by mass. A dispersion containing microcapsules for pest control was obtained.
The measured value of the median volume of the obtained microcapsules was 21.4 μm. The calculated value of the film thickness of the microcapsules was 29 nm. The capsule inclusion rate was 88.0%.

Comparative Example 4
Except for adding 35.38 parts by mass of tap water in the aqueous phase of Comparative Example 1 to 33.38 parts by mass and 2.0 parts by mass of calcium chloride ((reagent), manufactured by Wako Pure Chemical Industries, Ltd.) to the aqueous phase. When all of them were operated in the same manner, they solidified during the reaction, and a microcapsule dispersion could not be obtained.

Comparative Example 5
All except that 35.38 parts by mass of tap water in the aqueous phase of Comparative Example 1 was added to 33.38 parts by mass and 2.0 parts by mass of ammonium chloride ((reagent), manufactured by Tokyo Kasei Co., Ltd.) was added to the aqueous phase. When the same operation was carried out, it solidified during the reaction, and a microcapsule dispersion could not be obtained.

Comparative Example 6
All except that 35.38 parts by mass of tap water in the aqueous phase of Comparative Example 1 was added to 33.38 parts by mass and 2.0 parts by mass of sodium acetate ((reagent), manufactured by Tokyo Kasei Co., Ltd.) was added to the aqueous phase. When the same operation was carried out, it solidified during the reaction, and a microcapsule dispersion could not be obtained.

Comparative Example 7
In the oil phase of Comparative Example 1, 0.12 parts by mass of MR-400 was 0.23 parts by mass, 0.12 parts by mass of TMDI was 0 parts by mass, and 35.38 parts by mass of tap water in the aqueous phase was 35.39 parts. All were operated in the same manner except that 5.0 parts by mass of propylene glycol, which is an inhibitor of sedimentation agent, was changed to 10.0 parts by mass, and 8.75 parts by mass of tap water was changed to 13.75 parts by mass. A dispersion containing 34% by mass of pest control microcapsules was obtained.
The measured value of the median volume of the obtained microcapsules was 26.9 μm. The calculated value of the film thickness of the microcapsules was 34 nm. The capsule inclusion rate was 93.4%.

Comparative Example 8
In the oil phase of Comparative Example 1, 0.12 parts by mass of MR-400 was 0 parts by mass, 0.12 parts by mass of TMDI was 0.46 parts by mass, and 35.38 parts by mass of tap water in the aqueous phase was 35.16 parts. When all the operations were carried out in the same manner except that 8.75 parts by mass of tap water of the sedimentation inhibitor was changed to 13.75 parts by mass, aggregation occurred during aging and no microcapsule dispersion was obtained. ..

Comparative Example 9
Comparative Example 1 (2-isopropyl-4-methylpyrimidyl-6) -diethylthiophosphate (generic name: diazinone) 35.9 parts by mass to 27.1 parts by mass, MR-400 0.12 parts by mass of the oil phase 1.0 part by mass, TMDI 0.12 part by mass to 1.0 part by mass, K-800 2.5 part by mass to 2.0 part by mass, oil phase JX normal paraffin ((trade name), Add 7.5 parts by mass of hydrocarbon solvent, JXTG Energy Co., Ltd., add 34.9 parts by mass of tap water in the aqueous phase, 0.08 parts by mass of hardener diethylenetriamine, 0.3 parts by mass, and ethylenediamine. All operations were carried out in the same manner except that 0.3 parts by mass was added and 8.75 parts by mass of tap water as an anti-settlement agent was changed to 13.75 parts by mass, and a pest control microcapsule having a diazinone content of 25% by mass was contained. A dispersion was obtained.
The measured value of the median volume of the obtained microcapsules was 40.0 μm. The calculated film thickness of the microcapsules was 450 nm. The capsule inclusion rate was 99.9%.

Comparative Example 10
MR-400 ((trade name)) as an oil-soluble film-forming component in 21.45 parts by mass of (RS) -O-2,4-dichlorophenyl = O-ethyl = S-propyl = phosphorodithioate (generic name: prothiophos) ), Polymethylene polyphenyl polyisocyanate, manufactured by Tosoh Corporation) 0.13 parts by mass was added and mixed uniformly to prepare an oil phase component.
In another container, 1.8 parts by mass of an 8.3% by mass aqueous solution of PVA-217 ((trade name), polyvinyl alcohol, manufactured by Kuraray Co., Ltd.), 20.49 parts by mass of tap water, Antifoam E-20 ( (Trade name), silicone emulsion, manufactured by Kao Corporation) 0.2 parts by mass was added to prepare an aqueous phase component.
Put the oil phase component and the aqueous phase component in a 300 mL separable flask, and use Hiscotron (manufactured by Microtech Nithion Co., Ltd.) to stir for 2 minutes at a rotation speed of 2500 rpm and then for 6 minutes at a rotation speed of 12500 rpm. The oil phase component was dispersed to prepare an O / W type emulsion. A mixed solution of 0.04 part by mass of ethylenediamine and 0.3 part by mass of tap water 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.
In addition, as a settling inhibitor, 5 parts by mass of propylene glycol ((trade name), manufactured by ADEKA Corporation), 0.1 part by mass of Roadpole 23 ((trade name), xanthan gum, manufactured by Solvay Nikka Co., Ltd.), Kunipia F ((trade name), bentonite, manufactured by Kunimine Kogyo Co., Ltd.), 0.2 parts by mass, Proxel GXL (S) ((trade name), bactericide, manufactured by Lonza Japan Co., Ltd.) 0.15 mass Parts were added and mixed uniformly to obtain a dispersion containing pest control microcapsules having a prothiophos content of 40% by mass.
The measured value of the median volume of the obtained microcapsules was 17.0 μm. The calculated value of the film thickness of the microcapsules was 25 nm. The capsule inclusion rate was 91.9%.

Comparative Example 11
S-α-ethoxycarbonylbenzyl = O, O-dimethyl = phosphorodithioate (generic name: PAP, fentoate) in 21.68 parts by mass, MR-400 ((trade name), polymethylene) as an oil-soluble film-forming component. Polyphenyl polyisocyanate, manufactured by Tosoh Corporation, 0.075 parts by mass was added and mixed uniformly to prepare an oil phase component.
An aqueous phase component was prepared by placing 3.0 parts by mass of a 5% aqueous solution of PVA-217 ((trade name), polyvinyl alcohol, manufactured by Kuraray Co., Ltd.) and 15.27 parts by mass of tap water in another container.
Put the oil phase component and the aqueous phase component in a 300 mL separable flask, and use Hiscotron (manufactured by Microtech Nithion Co., Ltd.) to stir for 2 minutes at a rotation speed of 2500 rpm and then for 2 minutes at a rotation speed of 5000 rpm to obtain the oil. The phase components were dispersed to prepare an O / W type emulsion. A mixed solution of 0.025 parts by mass of diethylenetriamine and 0.3 parts by mass of tap water 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.
In addition, as an anti-precipitation agent, 5 parts by mass of propylene glycol ((trade name), manufactured by ADEKA Corporation), 0.05 parts by mass of Roadpole 23 ((trade name), xanthan gum, manufactured by Solvay Nikka Co., Ltd.), Theoras RC591 ((trade name), carboxymethyl cellulose, manufactured by Asahi Kasei Co., Ltd.), 0.125 parts by mass, Proxel GXL (S) ((trade name), bactericide, manufactured by Lonza Japan Co., Ltd.) by 0.1 mass A part and 4.375 parts by mass of tap water were added and mixed uniformly to obtain a dispersion containing pest control microcapsules having a fentoate content of 40% by mass.
The measured value of the median volume of the obtained microcapsules was 24.0 μm. The calculated value of the film thickness of the microcapsules was 19 nm. The capsule inclusion rate was 94.2%.

Comparative Example 12
2-sec-Butylphenyl-N-methylcarbamate (generic name: BPMC, phenocarb) in 15.5 parts by mass, MR-400 ((trade name), polymethylenepolyphenylpolyisocyanate, Tosoh) as an oil-soluble film-forming component 0.15 parts by mass of (manufactured by Co., Ltd.) and 5.0 parts of Solbesso ((trade name), manufactured by Exxon Mobile Co., Ltd.) were added and mixed uniformly to prepare an oil phase component.
In another container, 3 parts by mass of a 5% by mass aqueous solution of PVA-217 ((trade name), polyvinyl alcohol, manufactured by Kuraray Co., Ltd.) and 18.2 parts by mass of tap water were placed to prepare an aqueous phase component.
Put the oil phase component and the aqueous phase component in a 300 mL separable flask, and stir with Hiscotron (manufactured by Microtech Nithion Co., Ltd.) at a rotation speed of 2500 rpm for 2 minutes and then at a rotation speed of 5000 to 6000 rpm for 2 minutes. The oil phase component was dispersed to prepare an O / W type emulsion. A mixed solution of 0.05 parts by mass of diethylenetriamine and 0.3 parts by mass of tap water 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.
In addition, 2.5 parts by mass of propylene glycol ((trade name), manufactured by ADEKA Corporation) and 0.1 mass of load pole 23 ((trade name), xanthan gum, manufactured by Solvay Nikka Co., Ltd.) as anti-settlement agents. , Theoras RC591 ((trade name), carboxymethyl cellulose, manufactured by Asahi Kasei Co., Ltd.), 0.1 part by mass, Proxel GXL (S) ((trade name), bactericide, manufactured by Lonza Japan Co., Ltd.). 1 part by mass and 5 parts by mass of tap water were added and mixed uniformly to obtain a dispersion containing pest control microcapsules having a BPMC content of 30% by mass.
The measured value of the median volume of the obtained microcapsules was 24.0 μm. The calculated value of the film thickness of the microcapsules was 35 nm. The capsule inclusion rate was 88.5%.

For Examples 1 to 27 and Comparative Examples 1 to 10 (comparative examples that could be microencapsulated), the median volume diameter, film thickness, and capsule encapsulation rate of the microcapsules are summarized in Tables 1-1 and 1-2. Example 28 and Comparative Example 11 are summarized in Table 1-3. In addition, Example 29 and Comparative Example 12 are summarized in Table 1-4.

All of the formulations of the examples showed a high capsule encapsulation rate of 95% or more. It is probable that the inclusion of the dispersant maintained high dispersion stability during dispersion, so that encapsulation proceeded rapidly and stably, and the capsule membrane became stronger. On the other hand, the capsule encapsulation rate of Comparative Examples containing no dispersant was less than 95% except for Comparative Example 9 having a thick film thickness, and it is considered that the membrane is weak and the capsules are easily broken.

Test Example 1 (accelerated stability test)
The formulations of Examples and Comparative Examples were stored in a constant temperature bath at 54 ° C. for 2 weeks and then taken out, and the active ingredient content and capsule encapsulation rate were measured. The results are shown in Table 2-1 and Table 2-2.

Regarding the active ingredient content, there was no significant difference between the initial value and the formulation of the example and the comparative example at 54 ° C. for 2 weeks, and both were stable. Regarding the capsule encapsulation rate, the decomposition rate of the formulation of the example was 5% or less even after storage at 54 ° C. for 2 weeks, and the decomposition rate was kept very low as a whole. On the other hand, in the pharmaceutical product of the comparative example, a high capsule decomposition rate was observed after storage at 54 ° C. for 2 weeks, or an apparent increase in capsule encapsulation rate was observed, in which it is presumed that the free component of the active ingredient was decomposed. Since the expiration date of the pesticide preparation is usually 2 years or more, it is considered that the storage stability of the preparation of the example is high from the result of the accelerated test at 54 ° C. for 2 weeks, which is the storage condition equivalent to the room temperature of 2 years. ..

Test Example 2 (spray test)
A diluent is prepared using the formulation of the example, a spray pressure test is performed using a power atomizer, and the amount of free ingredient of the active ingredient outside the microcapsules before and after spraying in the diluent is measured and calculated. The encapsulation rate in the formulation was measured. The results are shown in Table 3.
The spray pressure test was carried out by the following method. A diluted solution for spraying was prepared by diluting 50 mL of the preparation in 50 L of tap water, and then sprayed on a poly film at a spraying pressure of 1.5 to 4.0 MPa to recover the sprayed solution.
(Used equipment)
Power sprayer: BIG M GS205
Nozzle used: D8 fan-shaped nozzle (manufactured by Yamaho Co., Ltd.)
(Formation used)
Example 21

Here, the free component content in the dilute solution is the amount of free components outside the microcapsules in the dilute solution calculated from the following formula based on the total amount of active ingredients, and the analysis method is as follows. About 100 parts by mass of a 1000-fold diluted solution of the microcapsule preparation was passed through a membrane filter having a pore size of 45 μm, and the microcapsules were filtered to obtain a sample solution. Separately, an acetonitrile solution having an active ingredient of about 20 ppm was prepared and used as a standard solution. The standard solution and the sample solution were analyzed by high performance liquid chromatography, the concentration of the free ingredient of the active ingredient was determined by the absolute calibration curve method, and then the encapsulation rate of the active ingredient was calculated by the following formula (III).

Formula (III) Free component amount (mg) = standard solution concentration (ppm) x (peak area of sample solution / peak area of standard solution) x amount of diluted solution (L)

The formulation of the example showed a high capsule encapsulation rate regardless of the spray pressure. Normally, when spraying pesticides such as speed sprayers, it is often sprayed at 1.5 MPa or less, so it is considered that the formulation of this example does not break the capsule even after spraying, ensuring safety for workers. Be done.

Test Example 3 (disappearance test)
Add 2 mL of a 200-fold diluted solution of the microcapsule pesticide composition preparation of Example 21 and Comparative Example 9 to a petri dish, leave it in a greenhouse after drying, analyze the amount of active ingredient after 1, 3 and 7 days, and analyze the initial force. The attenuation factor of was calculated. The result is shown in FIG. Further, the electron micrographs showing the microcapsule shape after 1, 3, and 7 days of Example 21 are shown in FIGS. 2 to 4, and the electron micrographs showing the microcapsule shape after 1, 3, and 7 days of Comparative Example 9 are shown in FIGS. 5 and 5. Shown in 7.

Since the pharmaceutical product of the example disappears rapidly, then decays with time and disappears by 90% or more after 7 days, the initial effect of the active ingredient can be expected. On the other hand, in the formulation of the comparative example, the active ingredient is hardly attenuated even after 3 days, and only about 40% disappears even after 7 days, so that the initial effect cannot be expected and there is a concern that the active ingredient remains.
Based on the above, the microcapsule pesticide composition of the present invention can achieve both a thin capsule film thickness and a high capsule encapsulation rate, which was not possible in the past, and as a result, can withstand a high spraying pressure during pesticide spraying. The toxicity to workers can be reduced, and the initial effect can be achieved by promptly releasing the active ingredient.

Claims (11)

A microcapsule pesticide composition containing a microcapsule containing a pesticide active ingredient having a water solubility of 1000 ppm or less at 20 ° C. and an aqueous phase.
The volume median diameter of the microcapsules is 1 to 50 μm, and the film thickness of the microcapsules defined by the following formula (I) is 5 to 50 nm.
The microcapsule membrane is a microcapsule composed of a polyurea membrane having an aromatic ring structure and / or a polyurethane membrane.
One selected from the group consisting of aromatic polymer salts and / or sodium chloride, potassium chloride, disodium hydrogen phosphate, sodium dihydrogen phosphate, dipotassium hydrogen phosphate and potassium dihydrogen phosphate as dispersants in the aqueous phase. Contains the above inorganic salts,
Microcapsule pesticide composition.
Formula (I) Film thickness (nm) = (Membrane material weight / Core material weight) × (Core material density / Membrane material density) × (Medium volume diameter / 6) × 1000 The microcapsule pesticide composition according to claim 1, wherein the ratio of the volume median diameter of the microcapsules to the film thickness of the microcapsules (volume median diameter / film thickness) is 100 to 2000. The microcapsule pesticide composition according to claim 1 or 2, wherein the aromatic polymer salt is at least one selected from the group consisting of lignin sulfonate, alkylnaphthalene sulfonate and styrene maleate. The microcapsule pesticide composition according to any one of claims 1 to 3, wherein the content of the dispersant in the microcapsule pesticide composition is 0.01 to 5% by mass. The microcapsule pesticide composition according to any one of claims 1 to 4, wherein the pesticide active ingredient is an organophosphorus-based or carbamate-based insecticide. The active pesticide is O, O-diethyl-O-2-isopropyl-6-methylpyrimidine-4-yl-phosphorothioate (generic name: diazinon), (RS) -O-2,4-dichlorophenyl = O-ethyl = S-propyl = phosphorodithioate (generic name: prothiophos), S-α-ethoxycarbonylbenzyl = O, O-dimethyl = phosphorodithioate (generic name: PAP, fentoate), or 2-sec-butylphenylmethyl The microcapsule pesticide composition according to any one of claims 1 to 5, which is carbamate (generic name: BPMC, phenocarb). A method for producing a microcapsule pesticide composition.
(1) (a) An oil phase containing a pesticide active ingredient and a polyisocyanate having an aromatic ring structure, and the content of the polyisocyanate having an aromatic ring structure is 3% by mass or less, and (b) an aromatic polymer as a dispersant. An aqueous phase containing a salt and / or an inorganic salt that is at least one selected from the group consisting of sodium chloride, potassium chloride, disodium hydrogen phosphate, sodium dihydrogen phosphate, dipotassium hydrogen phosphate and potassium dihydrogen phosphate. , The process of mixing,
(2) A step of dispersing the mixture to prepare an O / W emulsion.
(3) Step of preparing microcapsules by adding polyamine and / or polyol,
A method for producing a microcapsule pesticide composition. The method for producing a microcapsule pesticide composition according to claim 7, wherein the volume median diameter of the microcapsules is 1 to 50 μm, and the film thickness of the microcapsules defined by the following formula (I) is 5 to 50 nm.
Formula (I) Film thickness (nm) = (Membrane material weight / Core material weight) × (Core material density / Membrane material density) × (Medium volume diameter / 6) × 1000 The method for producing a microcapsule pesticide composition according to claim 7 or 8, wherein the ratio of the volume median diameter of the microcapsules to the film thickness of the microcapsules (volume median diameter / film thickness) is 100 to 2000. The microcapsule pesticide composition according to any one of claims 7 to 9, wherein the aromatic polymer salt is at least one selected from the group consisting of lignin sulfonate, alkylnaphthalene sulfonate and styrene maleate. Manufacturing method. The method for producing a microcapsule pesticide composition according to any one of claims 7 to 10, wherein the content of the dispersant in the microcapsule pesticide composition is 0.01 to 5% by mass.

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