JP5437811B2 - Method for producing microcapsules - Google Patents

Description

  The present invention relates to a microcapsule containing a microcapsule containing a pesticidal component and a method for producing the same.

The microencapsulation of the pest control component has advantages such as improving the alkali resistance, soil stability, and efficacy sustainability of the encapsulated bioactive component.
For example, a neonicotinoid compound is known to have insufficient alkali resistance, but a slurry containing a neonicotinoid compound, a dispersion medium, and a dispersant having a molecular weight of 1000 or more, including a tertiary amine. It has been proposed to improve the alkali resistance, soil stability, and efficacy sustainability of neonicotinoid compounds by wet-grinding and microencapsulating (see, for example, Patent Document 1 below).
Japanese Unexamined Patent Publication No. 2000-247821

  However, in the termite control agent described in Patent Document 1, an interfacial polymerization method is used for microencapsulating a neonicotinoid compound. In the interfacial polymerization method, an oil phase and an aqueous phase are required, and the organic solvent contained in the oil phase remains in the microcapsules obtained thereby. On the other hand, since termite control agents are sprayed under the floor of a house, reduction of organic solvents is desired.

  Then, the objective of this invention is providing the microcapsule agent with which the remaining organic solvent was reduced.

  In order to achieve the above object, the present inventors diligently studied the reduction of the organic solvent contained in the microcapsule, and found that a pest control component having a saturation solubility in water at 20 ° C. of 0.5% by weight or less. And a dispersion stabilizer, or a dispersion stabilizer and a surfactant are microencapsulated using an interfacial polymerization method, or the saturated solubility in water at 20 ° C. is 0.5. The organic suspension contained in the microcapsule is prepared by microencapsulating an aqueous suspension containing a weight percent or less pest control component and a surfactant using a method selected from an insolubilization reaction method and a spray drying method. As a result of finding the knowledge that can reduce the solvent and further researching it, the present invention has been completed.

That is, the present invention
(1) An aqueous suspension containing a pesticidal component having a saturation solubility in water at 20 ° C. of 0.5% by weight or less and a dispersion stabilizer, or a dispersion stabilizer and a surfactant, A microcapsule obtained by microencapsulation using an aqueous suspension containing a pest control component having a saturation solubility in water at 20 ° C. of 0.5% by weight or less and a surfactant are insolubilized. And microcapsules obtained by microencapsulation using a method selected from spray drying methods,
(2) The microcapsule according to (1), wherein the dispersion stabilizer is a water-soluble polymer,
(3) The microcapsule according to (1), wherein the surfactant is an aromatic sulfonate.
(4) The microcapsule according to (1), wherein the aromatic sulfonate is formaldehyde condensed naphthalene sulfonate or alkyldiphenyl ether sulfonate,
(5) An interfacial polymerization method is used for the microcapsule, and in the interfacial polymerization method, an oil phase containing a first film-forming component and an organic solvent having a boiling point of 130 ° C. or lower, and a first water containing the aqueous suspension The first emulsion is prepared by blending the phase, and then the second emulsion is prepared by blending the first emulsion and the second aqueous phase containing the dispersion stabilizer and water, The microcapsule according to (1), wherein an organic solvent is removed after blending a second film-forming component that reacts with the first film-forming component into the second emulsion.
(6) a step of preparing an aqueous suspension containing a pest control component having a saturated solubility in water at 20 ° C. of 0.5% by weight or less and a surfactant, and a first film-forming component and a boiling point of 130 ° C. or less A step of preparing a first emulsion by blending an oil phase containing an organic solvent and a first aqueous phase containing the aqueous suspension, a first emulsion containing the first emulsion, a dispersion stabilizer and water. A step of preparing a second emulsion by blending two aqueous phases, a step of blending a second film-forming component that reacts with the first film-forming component into the second emulsion, and removing the organic solvent And a process for producing a microcapsule.

  According to the microcapsule of the present invention, since the pest control component prepared as an aqueous suspension is encapsulated in the microcapsule, the organic solvent remaining in the microcapsule can be reduced. Further, according to the method for producing a microcapsule of the present invention, since the second emulsion is further prepared after the first emulsion is prepared, the pest control component prepared as an aqueous suspension is microencapsulated. it can. Furthermore, since the organic solvent mix | blended with an oil phase is removed, the microcapsule agent with which the remaining organic solvent was reduced can be manufactured.

The microcapsule of the present invention is prepared by treating an aqueous suspension containing a pest control component having a saturated solubility in water at 20 ° C. of 0.5% by weight or less by any of an interfacial polymerization method, an insolubilization reaction method, and a spray drying method. Microcapsules obtained by microencapsulation using any of these methods are contained.
The pest control component is not particularly limited as long as the saturated solubility in water at 20 ° C. is 0.5% by weight or less, and preferably 0.1% by weight or less, and examples include an antifungal agent and a bactericide.

Examples of the anti-anticide include neonicotinoid compounds, pyrethroid compounds, organochlorine compounds, organophosphorus compounds, carbamate compounds, pyrrole compounds, phenylpyrazole compounds, oxadiazine compounds, semicarbazone compounds, and the like. Can be mentioned. Preferably, neonicotinoid compounds are used.
Examples of neonicotinoid compounds include (E) -1- (2-chlorothiazol-5-ylmethyl) -3-methyl-2-nitroguanidine (generic name: clothianidin), N-acetyl-N- (2 -Chlorothiazol-5-yl) methyl-N'-methyl-N "-nitroguanidine, N- (2-chlorothiazol-5-yl) methyl-N-methoxycarbonyl-N'-methyl-N" -nitroguanidine 1- (6-chloro-3-pyridylmethyl) -N-nitroimidazoline-2-ylideneamine (generic name: imidacloprid), 3- (2-chloro-thiazol-5-ylmethyl) -5- [1,3, 5] oxadiazinan-4-ylindene-N-nitroamine (generic name: thiamethoxam), (E) -N ′-[(6-chloro-3-pyridinyl) methyl]- N "-cyano-N'-methylacetamidine (generic name: acetamiprid) and the like. Preferably, (E) -1- (2-chlorothiazol-5-ylmethyl) -3-methyl-2-nitroguanidine (Generic name: clothianidin).

Examples of pyrethroid compounds include allethrin, permethrin, tralomethrin, bifenthrin, acrinatrin, alpha cypermethrin, cyfluthrin, ciphenothrin, praretrin, etofenprox, silafluophene, fenvalerate, and the like.
Examples of the organic chlorine compound include Kelsen.

Examples of the organophosphorus compounds include phoxime, pyridafenthione, fenitrothion, tetrachlorvinphos, diclofenthione, propetanephos, and the like.
Examples of the carbamate compound include carbaryl, fenobucarb, propoxur and the like.
Examples of the pyrrole compound include chlorfenapyr.

Examples of the phenylpyrazole-based compound include fipronil.
Examples of the oxadiazine compound include indoxacarb.
Examples of the semicarbazone compound include α- (α, α, α-trifluoro-m-toluoyl) -p-trinitrile-4- (p-trifluoromethoxyphenyl) semicarbazone.

  Examples of bactericides include organic iodine compounds such as IPBC (3-iodo-2-propenylbutylcarbamate) and Sampras (3-bromo-2,3-diiodo-2-propenylethyl carbonate), cyproconazole. ((2RS, 3RS; 2RS, 3SR) -2- (4-chlorophenyl) -3-cyclopropyl-1- (1H-1,2,4-triazol-1-yl) butan-2-ol), azaconazole ( 1-[[2- (2,4-dichlorophenyl) -1,3-dioxolan-2-yl] methyl] -1H-1,2,4-triazole), tebuconazole (α- [2- (4-chlorophenyl) Ethyl] -α (1,1-dimethylethyl) -1H-1,2,4-triazole-1-ethanol), propiconazole (1- [2- (2,4-dichloropheny ) -4-propyl-1,3-dioxolan-2-ylmethyl] -1H-1,2,4-triazole), thiabendazole (2- (4-thiazolyl) benzimidazole), isothiazoline (2- Organic nitrogen sulfur compounds such as n-octyl-4-isothiazolin-3-one), organic nitrogen such as dichlorofluanide (N, N-dimethyl-N′-phenyl- (N′-fluorodichloromethylthio) -sulfamide) Examples thereof include sulfur halogen compounds and benzimidazole compounds such as MBC (methyl-2-benzimidazole carbamate).

These pest control components may be used alone or in combination of two or more.
Preferably, an anti-anticide is used, more preferably a neonicotinoid compound.
In the present invention, in order to produce microcapsules using the interfacial polymerization method, first, the above-mentioned pest control component as an essential component and a dispersion stabilizer, a surfactant, an additive and water as optional components are blended. An aqueous suspension is prepared by wet grinding.

Examples of the dispersion stabilizer include a water-soluble polymer.
Examples of the water-soluble polymer include a polyol polymer (eg, Agrisol FL-104FA: manufactured by Kao), sodium polyacrylate (eg, Rhegic 250H: manufactured by Nippon Pure Chemical), polyvinyl alcohol (eg, Kuraray Poval 217 ( Degree of saponification: about 87.0-89.0 mol%, degree of polymerization: 1700): Kuraray, Kuraray Poval 224 (degree of saponification: about 87.0-89.0 mol%, degree of polymerization: 2400): Kuraray, Kuraray Poval 117 (degree of saponification: about 98.0 to 99.0 mol%, degree of polymerization: 1700): manufactured by Kuraray), polysaccharide (eg, gum arabic, gelatin, guar gum, xanthan gum (eg, Rhodopol 23: manufactured by Rhone-Poulenc), Starch (eg, manufactured by Wako Pure Chemical Industries), starch derivatives [eg, starch hydrolysates (eg, paraindex: pine Chemical Industry), soluble starch (eg, Stabilose S-10: made by Matsutani Chemical Industry), enzyme-modified starch (eg, Amicol 6L: made by Nissho Chemical), pregelatinized starch (eg, Corn Alpha: made by Nissho Chemical) ), Dextrins (eg, dextrin, cyclodextrin) and the like]], carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose (eg, Metrolose 60SH-15 (manufactured by Shin-Etsu Chemical)) and the like. Preferably, polyvinyl alcohol is used.

The dispersion stabilizer may be added when preparing an aqueous suspension containing a pesticidal component, and will be described in detail later. It may be added both in the preparation of the suspension and in the microencapsulation.
Examples of the surfactant include an anionic surfactant and a nonionic surfactant.

Examples of the anionic surfactant include aromatic sulfonate alkyl sulfonate, carboxylate, sulfate ester salt, phosphate, phosphonate, amino acid salt and the like.
Aromatic sulfonates include alkyl phenyl sulfonates (eg, sodium dodecylbenzene sulfonate), alkyl naphthalene sulfonates, aralkyl naphthalene sulfonates, alkyl anthracene sulfonates, aryl phenyl sulfonates, aryl phenol sulfones. Acid salt, formaldehyde condensed naphthalene sulfonate (example: sodium formaldehyde condensed naphthalene sulfonate, New Calgen FS-4 (manufactured by Takemoto Yushi)), alkyl diphenyl ether sulfonate (example: Perex SS-L (manufactured by Kao)), dialkyl Examples include sulfosuccinate (eg, Neocor P (Daiichi Kogyo Seiyaku)) and lignin sulfonate.

  Examples of the aryl group in arylphenyl sulfonic acid or arylphenol sulfonic acid include aryl groups having 6 to 14 carbon atoms such as phenyl and naphthyl. The number of substitution is 1 to 3. Examples of the alkyl group in the alkyl naphthalene sulfonic acid include alkyl groups having 1 to 6 carbon atoms such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl and tert-butyl. . The number of substitution is 1-7. Examples of the aralkyl group in aralkylnaphthalenesulfonic acid include phenyl-C1-C4 alkyl groups such as benzyl, phenethyl, and phenylpropyl, benzhydryl, and trityl. The number of substitution is 1 to 3. Examples of the alkyl group in the alkylanthracenesulfonic acid include alkyl groups having 1 to 6 carbon atoms such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, and tert-butyl. . The number of substitution is 1-9. The degree of condensation of the aromatic ring and formaldehyde in the formaldehyde condensed aromatic sulfonate is 1.2 to 30, preferably 1.2 to 10.

Examples of the alkyl sulfonate include alkyl sulfonate, alpha olefin sulfonate, polynaphthyl methane sulfonate, polyoxyalkylene alkyl ether sulfonate, polyoxyalkylene alkyl phenyl ether sulfonate, and the like.
Examples of carboxylates include fatty acid salts, polyoxyalkylene alkyl ether carboxylates, polyoxyalkylene alkyl phenyl ether carboxylates, and the like.
Examples of the sulfate ester salt include alkyl sulfate ester salts, polyoxyethylene alkyl ether sulfate salts, and oil and fat sulfate ester salts.

Examples of the phosphate include alkyl phosphates, polyoxyalkylene alkyl ether phosphates, polyoxyalkylene alkyl phenyl ether phosphates, and the like.
Examples of phosphonates include polyoxyalkylene alkyl ether phosphonates and polyoxyalkylene alkyl phenyl ether phosphonates.
Examples of amino acid salts include N-acyl sarcosinate, N-acyl glutamate, and N-methyl-N-acyl taurate.

As the anionic surfactant, an aromatic sulfonate is preferable, and formaldehyde condensed naphthalene sulfonate and alkyl diphenyl ether sulfonate are particularly preferable among them.
As the anionic surfactant, an aromatic sulfonate is preferable, and formaldehyde condensed naphthalene sulfonate and alkyl diphenyl ether sulfonate are particularly preferable among them.

Examples of nonionic surfactants include polyoxyalkylene alkyl ethers, polyoxyalkylene alkyl aryl ethers, polyoxyalkylene aralkyl aryl ethers, polyoxyalkylene aralkyl aryl ether formaldehyde condensates, polyoxyalkylene block copolymers, and the like. .
Examples of the polyoxyalkylene alkyl ether include polyoxyethylene alkyl ether (eg, Emulgen 108 (manufactured by Kao)).

Examples of the polyoxyalkylene alkyl aryl ether include polyoxyethylene nonyl phenyl ether (eg, Emulgen 950 (manufactured by Kao)), polyoxyethylene octyl phenyl ether, and the like.
As polyoxyalkylene aralkyl aryl ether. Examples include polyoxyethylene distyrenated phenyl ether (eg, Neugen EA-177 (Daiichi Kogyo Seiyaku)), polyoxyethylene monostyrenated phenyl ether, and the like.

Examples of the polyoxyalkylene block copolymer include polyoxyethylene-polyoxypropylene block copolymers (eg, Epan 485 (Daiichi Kogyo Seiyaku)). These surfactants may be used alone or in combination of two or more.
As the nonionic surfactant, polyoxyethylene alkyl ether is preferable.
These surfactants may be used alone or in combination of two or more.

A dispersion aid can be preferably added as an additive to the aqueous suspension. In addition, a suspension aid can be added as an additive for stabilizing the suspension and adjusting the viscosity. In addition, a water-soluble polymer, a pH adjuster, an antifreezing agent, an antifoaming agent, and an antiseptic can be optionally added as additives.
Dispersing aids include, for example, protective colloid agents that adsorb other hydrophobic substances by means of hydrophobic groups in the molecule.

  Examples of such a dispersion aid include polyvinyl pyrrolidone, alkylated vinyl pyrrolidone copolymer, vinyl pyrrolidone-styrene copolymer, vinyl pyrrolidone-vinyl acetate copolymer, vinyl pyrrolidone-unsaturated hydrocarbon copolymer, Vinyl pyrrolidone- (meth) acrylic acid ester copolymer, methyl vinyl ether-maleic anhydride copolymer, poly (meth) acrylic acid, alkali metal salt of poly (meth) acrylic acid, amine salt of poly (meth) acrylic acid , Poly (meth) acrylic acid- (meth) acrylic acid ester copolymer, carboxymethyl cellulose, and hydroxyethyl cellulose. Preferably, an alkylated vinylpyrrolidone copolymer and a vinylpyrrolidone-unsaturated hydrocarbon copolymer may be mentioned. In the present invention, an alkylated vinylpyrrolidone copolymer and a vinylpyrrolidone-unsaturated hydrocarbon copolymer are used. It is generically called an alkyl vinyl pyrrolidone copolymer.

  Examples of the alkyl group of the alkylvinylpyrrolidone copolymer include methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, tert-butyl, pentyl, iso-pentyl, tert-pentyl, Neopentyl, hexyl, iso-hexyl, 2,2-dimethylbutyl, heptyl, 2-methylhexyl, octyl, 2,2,4-trimethylpentyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl , Octadecyl, nonadecyl, icosyl, henicosyl, docosyl, tricosyl, tetracosyl and the like, and an alkyl group having 1 to 30 carbon atoms. Preferably, an alkyl group having 1 to 24 carbon atoms is used.

The percentage of the number of moles of the monomer having an alkyl group with respect to the total number of moles of the monomer forming the alkylvinylpyrrolidone copolymer is defined as the alkylation rate, and the alkylation rate is preferably alkyl. The conversion ratio is 70% or less, and more preferably the alkylation ratio is 5 to 50%.
Examples of the suspension aid include montmorillonite (eg, Kunipia F: manufactured by Kunimine Kogyo, Laponite: manufactured by Nisshin Kasei), colloidal silicon oxide (eg, Aerosil such as Aerosil 200: manufactured by Nippon Aerosil), colloidal silicon oxide -Aluminum oxide mixture (e.g., Aerosil COK84; SiO2 / Al2O3 = 82 to 86 (%) / 14 to 18 (%): manufactured by Nippon Aerosil), sepiolite (e.g., Aid Plus ML70DS-NV: manufactured by Mizusawa Chemical Industry), etc. Can be mentioned. Preferably, a colloidal silicon oxide-aluminum oxide mixture is used.

  Examples of the water-soluble polymer include polyol polymers (eg, Agrisol FL-104FA: manufactured by Kao), sodium polyacrylate (eg, Rheozic 250H: manufactured by Nippon Pure Chemical), polyvinyl alcohol (eg, Kuraray Poval 217 (degree of saponification: About 87.0-89.0 mol%, polymerization degree: 1700): Kuraray, Kuraray Poval 224 (degree of saponification: about 87.0-89.0 mol%, degree of polymerization: 2400): Kuraray, Kuraray poval 117 (saponification) Degree: about 98.0 to 99.0 mol%, degree of polymerization: 1700): manufactured by Kuraray), polysaccharides (eg, gum arabic, gelatin, guar gum, xanthan gum (eg, Rhodopol 23: manufactured by Rhone-Poulenc), starch (example) , Manufactured by Wako Pure Chemical Industries, Ltd.), starch derivatives [eg, starch hydrolysates (eg, Paindex: Matsutani Chemical Industry) ), Soluble starch (eg, Stabilose S-10: manufactured by Matsutani Chemical Co., Ltd.), enzyme-modified starch (eg, Amikol 6L: manufactured by Nissho Chemical), pregelatinized starch (eg, corn alpha: manufactured by Nissho Chemical), dextrin And the like (eg, dextrin, cyclodextrin) and the like]], polyethylene glycol (eg, PEG 6000: manufactured by Sanyo Kasei) and the like.

Examples of the pH adjuster include citric acid monohydrate.
Examples of the antifreezing agent include ethylene glycol, diethylene glycol, propylene glycol, glycerin and the like.
Examples of the antifoaming agent include silicone-based antifoaming agents (for example, Antihome E-20: manufactured by Kao Corporation).

Examples of the preservative include butyl paraben (n-butyl parahydroxybenzoate), potassium sorbate, sorbic acid, iodoacetamide and the like.
In the present invention, in order to produce microcapsules using the insolubilization reaction method or the spray drying method, first, the above-mentioned pest control component and surfactant are blended as essential components, and additives and water as optional components. And an aqueous suspension is prepared by wet milling.

Examples of the surfactant include the same surfactants as those exemplified for the surfactant in the above-mentioned interfacial polymerization method.
As an additive, the additive similar to the illustration of the additive in the said interfacial polymerization method is mentioned, for example.
For aqueous suspension,
(I) In the case of microencapsulation using the interfacial polymerization method,
(A) An aqueous suspension containing a pesticidal component and a dispersion stabilizer as essential components is prepared.
(B) An aqueous suspension containing a pest control component as an essential component is prepared, and then a dispersion stabilizer is added to form an aqueous phase.
(C) An aqueous suspension containing the pesticidal component and the dispersion stabilizer as essential components is prepared, and then the dispersion stabilizer is added again.
(D) An aqueous suspension containing a pest control component, a dispersion stabilizer, and a surfactant as essential components is prepared.

For aqueous suspensions,
(Ii) In the case of microencapsulation using a method selected from an insolubilization reaction method and a spray drying method, the aqueous suspension contains a pest control component and a surfactant.
In the above (i), (a), (b) and (c) in the case of microencapsulation using the interfacial polymerization method, for example, a dispersion stabilizer (aqueous suspension) is added to 100 parts by weight of the pest control component. When added before and after adjusting the liquid, the total amount is shown.) 1-1000 parts by weight, preferably 10-300 parts by weight, water 100-900 parts by weight, preferably 100-500 parts by weight It mixes with the compounding ratio of.

  Furthermore, for example, with respect to 100 parts by weight of the pest control component, the dispersion aid is 0.1 to 20 parts by weight, preferably 0.5 to 10 parts by weight, and the suspension aid is 0.1 to 20 parts by weight, preferably 0.5-10 parts by weight, water-soluble polymer 0-20 parts by weight, preferably 0-10 parts by weight, pH adjuster 0-20 parts by weight, preferably 0-10 parts by weight, antifreeze 0 -50 parts by weight, preferably 0-30 parts by weight, defoaming agent 0-5 parts by weight, preferably 0-2.5 parts by weight, preservative 0-5 parts by weight, preferably 0-2.5 parts. It mixes in the mixing ratio of parts by weight.

Next, after blending as described above, mixing is performed using a high-speed stirrer, and then wet pulverization is performed using a dyno mill or the like to complete the preparation of the aqueous suspension. The average particle diameter after wet pulverization is preferably 10 μm or less, more preferably 0.1 to 5 μm.
Here, as described above, the dispersion stabilizer may be added before the preparation of the aqueous suspension, or the aqueous suspension is prepared without adding the dispersion stabilizer, and then the dispersion stabilizer is added. Alternatively, an aqueous suspension may be prepared by adding a dispersion stabilizer, and then the dispersion stabilizer may be added again.

  In the case of microencapsulation using the interfacial polymerization method (in the case of (i) above) and including a pest control component, a dispersion stabilizer and a surfactant (in the case of (d) above) To prepare an aqueous suspension, first, for example, 1 to 1000 parts by weight of a dispersion stabilizer, preferably 10 to 300 parts by weight, and 1 to 50 parts by weight of a surfactant for 100 parts by weight of a pest control component. The blending ratio is 5 to 25 parts by weight, preferably 100 to 900 parts by weight of water, and preferably 100 to 500 parts by weight.

Further, the aqueous suspension has the same blending ratio as in the cases (a), (b) and (c), and if necessary, a dispersion aid, a suspension aid, a water-soluble polymer, a pH adjuster, Add antifreeze, antifoam, preservative.
Next, as in the case of (a), (b) and (c) above, the mixture is mixed using a high speed stirrer and then wet pulverized using a dyno mill or the like to complete the preparation of the aqueous suspension. The average particle diameter after wet pulverization is preferably 10 μm or less, more preferably 0.1 to 5 μm.

  In the case of microencapsulation using a method selected from an insolubilization reaction method and a spray drying method (in the case of (ii) above), in order to prepare an aqueous suspension, first, for example, pest control 1 to 50 parts by weight of surfactant, preferably 5 to 25 parts by weight, and 100 to 900 parts by weight of water, preferably 100 to 500 parts by weight, based on 100 parts by weight of component.

Furthermore, the aqueous suspension is mixed in the same proportion as in the case of (i) above, and if desired, a dispersion aid, suspension aid, water-soluble polymer, pH adjuster, antifreeze agent, antifoaming agent, Add preservatives.
Next, as in the case of (i) above, the mixture is mixed using a high-speed stirrer and then wet pulverized using a dyno mill or the like to complete the preparation of the aqueous suspension. The average particle diameter after wet pulverization is preferably 10 μm or less, more preferably 0.1 to 5 μm.

In any of the above cases, in order to add the water-soluble polymer, preferably, an aqueous solution of the water-soluble polymer is prepared in advance, and the aqueous solution is added so that the water-soluble polymer becomes the above-mentioned blending amount in terms of solid content ,Added.
Subsequently, in order to encapsulate the aqueous suspension thus wet pulverized, an interfacial polymerization method, an insolubilization reaction method, or a spray drying method is used, and an interfacial polymerization method is preferably used.

In addition, the insolubilization reaction method may use the name of the submerged curing coating method.
In the interfacial polymerization method, for example, an oil phase containing a first film-forming component and an organic solvent having a boiling point of 130 ° C. or less, and the above aqueous suspension (however, an aqueous suspension containing the pest control component (surfactant) The dispersion stabilizer may be added before, after, or before and after the preparation of the first emulsion. And then blending the first emulsion and a second aqueous phase containing a dispersion stabilizer and water to prepare a second emulsion, and then adding the first film-forming component to the second emulsion After blending the reactive second film forming component, the organic solvent is removed.

The oil phase is prepared by blending the first film forming component in an organic solvent having a boiling point of 130 ° C. or less and mixing.
The first film-forming component is an oil-soluble compound, and is a compound that forms a film by reacting with a second film-forming component described later. As a 1st film | membrane formation component, the well-known thing normally used for microencapsulation may be used, For example, polyisocyanate, polycarboxylic acid chloride, polysulfonic acid chloride, etc. are mentioned.

  Examples of the polyisocyanate include aromatic polyisocyanates such as diphenylmethane diisocyanate and toluene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, and alicyclic polyisocyanates such as hydrogenated diphenylmethane diisocyanate, And araliphatic polyisocyanates such as xylylene diisocyanate and tetramethyl xylylene diisocyanate and the like, and further, modified products thereof such as dimers, trimers, biurets, allophanates, carboimides, uretdiones, oxalates, which are derivatives of these polyisocyanates. Derivative-modified polyisocyanate modified with diazinetrione or the like, for example, Such as polyol-modified polyisocyanate obtained by pre-reacting low molecular weight polyols such as Chi roll propane.

Examples of the polycarboxylic acid chloride include sebacic acid dichloride, adipic acid dichloride, azelaic acid dichloride, terephthalic acid dichloride, and trimesic acid dichloride. Examples of the polysulfonic acid chloride include benzenesulfonyl dichloride. Can be mentioned.
These first film forming components may be used alone or in combination of two or more. Preferred are polyisocyanates, more preferred are aliphatic and alicyclic polyisocyanates, and particularly preferred are trimer-modified products and polyol-modified products of hexamethylene diisocyanate and isophorone diisocyanate.

  The organic solvent is an organic solvent having a boiling point of 130 ° C. or less, preferably a boiling point of 25 to 130 ° C., for example, methyl formate, ethyl formate, propyl formate, butyl formate, isobutyl formate, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate , Esters such as butyl acetate isobutyl acetate, sec-butyl acetate, ethyl propionate, methyl butyrate, ethyl butyrate, ketones such as methyl ethyl ketone (MEK), methyl propyl ketone, methyl butyl ketone, methyl isobutyl ketone, diethyl ketone, , Pentane, 2-methylbutane, hexane, 2-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, heptane, 2,2,3-trimethylpentane, isooctane, 2,2,5-trimethylhexane, Cyclopentane, methyl cycl Hydrocarbons such as pentane, cyclohexane, methylcyclohexane, cyclohexene, benzene, toluene, such as dichloromethane, trichloromethane, tetrachloromethane, 1,1-dichloroethane, 1,2-dichloroethane, 1,1,1-trichloroethane, 1 1,2-trichloroethane, 1,1-dichloroethylene, 1,2-dichloroethylene, trichloroethylene, tetrachloroethylene, 1-chloropropane, 2-chloropropane, 1,2-dichloropropane, 3-chloropropene, 1-chlorobutane, 2-chlorobutane 1-chloro-2-methylpropane, 2-chloro-2-methylpropane, 1-chloropentane, bromoethane, 1-bromopropane, 2-bromopropane, fluorobenzene, trifluorotoluene, Safluorobenzene, chlorobromomethane, 1-bromo-2-chloroethane, 1,1,2-trichloro-1,2,2-trifluoroethane, 1,1,2,2-tetrachloro-1,2-difluoroethane, etc. And halogenated hydrocarbons.

The oil phase is prepared, for example, by using the first film-forming component in an organic solvent, and the blending ratio of the first film-forming component is 10 to 100 parts by weight, preferably 30 to 100 parts by weight with respect to 100 parts by weight of the organic solvent. Blend and mix.
The first aqueous phase is prepared by mixing the dispersion stabilizer, the aqueous suspension, and water.
Examples of the dispersion stabilizer include polyvinyl alcohol, polyvinyl pyrrolidone, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl methylcellulose, poly (meth) acrylic acid, alkali metal salt of poly (meth) acrylic acid, and amine of poly (meth) acrylic acid. Examples include salt, guar gum, and xanthan gum. Preferably, polyvinyl alcohol is used.

The dispersion stabilizer is preferably prepared in advance as an aqueous solution. For example, the dispersion stabilizer is dissolved and prepared in water to a concentration of 1 to 30% by weight, preferably 5 to 15% by weight.
The first aqueous phase is prepared, for example, by adding 10 to 100 parts by weight, preferably 20 to 50 parts by weight, of the dispersion stabilizer aqueous solution and the aqueous suspension with respect to 100 parts by weight of the aqueous suspension. Mix in the mixing ratio of parts and mix.

Next, the first aqueous phase and the oil phase are mixed to prepare a first emulsion.
The first emulsion is prepared, for example, by mixing the oil phase and the first aqueous phase with respect to 100 parts by weight of the oil phase, 30 to 100 parts by weight of the first aqueous phase, preferably 50 to 100 parts by weight. And is stirred at room temperature using a homomixer or the like.
Thus, the first emulsion is prepared as a W / O type emulsion.

Subsequently, the 2nd aqueous phase containing a dispersion stabilizer and water is mix | blended with a 1st emulsion, and a 2nd emulsion is prepared.
For the preparation of the second aqueous phase, for example, the dispersion stabilizer is dissolved in water to a concentration of 1 to 30% by weight, preferably 2.5 to 15% by weight.
The preparation of the second emulsion includes, for example, the first emulsion and the second aqueous phase, 30 to 200 parts by weight of the second aqueous phase, preferably 40 to 100 parts by weight with respect to 100 parts by weight of the first emulsion. The mixture is mixed at a mixing ratio of 1 part, and stirred at room temperature using a homomixer or the like.

Thus, the second emulsion is prepared as a W / O / W type emulsion. Note that the second aqueous phase is not prepared separately, and the second aqueous phase is mixed with the first emulsion directly by adding the dispersion stabilizer and water (or dispersion stabilizer aqueous solution) in the above-described ratio. One emulsion can be blended.
Next, a second film-forming component that reacts with the first film-forming component is added to the second emulsion and reacted.

The second film-forming component is a water-soluble compound and may be a known one that is usually used for microencapsulation, and examples thereof include chain extenders such as polyamines and polyols.
Examples of the polyamine include ethylenediamine, propylenediamine, hexamethylenediamine, diaminotoluene, phenylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, piperazine and the like.

  Examples of the polyol include ethylene glycol, propanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, dipropylene glycol, cyclohexanedimethanol, glycerin, and trimethylol. Examples include propane, polyethylene glycol, and polypropylene glycol.

These second film-forming components may be used alone or in combination of two or more. Preferably, polyamine, especially diethylenetriamine is preferably used.
In order to add the second film forming component, for example, the second film forming component may be dropped into the second emulsion, and in order to add the second film forming component, for example, the second film forming component It is dripped until it becomes the quantity which becomes a substantially equivalent equivalent (For example, when polyisocyanate and a polyamine are used, the ratio by which the equivalent ratio of an isocyanate group / amino group will be substantially 1) with respect to 1 film formation component.

  By adding such a second film-forming component, the first film-forming component and the second film-forming component react at the interface between the oil phase and the water phase, thereby enclosing the pest control component. Capsules can be obtained. In order to promote this reaction, for example, after the addition of the second film forming component, at about 50 to 150 ° C., preferably about 50 to 100 ° C., about 30 minutes to 5 hours, preferably about 1 to 3 hours. It is preferable to heat with stirring.

Then, if necessary, known additives such as thickeners, antifreeze agents, fungicides, preservatives, suspension aids, and water are appropriately added to the dispersion containing the microcapsules thus obtained. Can be blended.
Examples of the thickener include sodium polyacrylate.
Examples of the antifreezing agent include ethylene glycol, diethylene glycol, propylene glycol, glycerin and the like.

Examples of the antifungal agent include 3-iodo-2-propynylbutylcarbamate.
Examples of the preservative include butyl paraben (n-butyl parahydroxybenzoate), potassium sorbate, sorbic acid, iodoacetamide and the like.
Examples of the suspension aid include the same compounds as those described in the preparation of the aqueous suspension, and preferably montmorillonite.

Subsequently, the microcapsule of this invention can be obtained by removing the organic solvent mix | blended with the oil phase from the obtained dispersion liquid containing the microcapsule. Examples of the method for removing the organic solvent include heating, vacuum distillation and the like, and preferably vacuum distillation.
The vacuum distillation is performed by heating to 30 to 130 ° C., preferably 40 to 130 ° C. while distilling the system to 130 to 75000 Pa, preferably 130 to 55000 Pa.

In the insolubilization reaction method, for example, a dispersion obtained by mixing an aqueous solution of an alkali metal salt of a polyanion that exhibits water insolubility by forming a salt with calcium ions and the aqueous suspension is converted into an aqueous calcium salt solution. What is necessary is just to dripping.
Examples of such alkali metal salts of polyanions include potassium salts and sodium salts such as alginic acid, pectic acid and carboxymethylcellulose. Preferably, the sodium salt of alginic acid is used.

The calcium salt is not particularly limited as long as it shows water solubility, and examples thereof include calcium chloride, calcium bromide, calcium iodide, calcium hydroxide, calcium nitrate, and calcium acetate. Preferably, calcium chloride is used.
The aqueous alkali metal salt solution of the polyanion is prepared by, for example, dissolving the alkali metal salt of the polyanion in water to a concentration of 0.1 to 10% by weight, preferably 0.5 to 5% by weight.

The calcium salt aqueous solution is prepared, for example, by dissolving the calcium salt in water so as to have a concentration of 0.1 to 10% by weight, preferably 0.5 to 5% by weight.
In the insolubilization reaction method, for example, an aqueous sodium salt solution of a polyanion is dropped into an aqueous calcium salt solution by using a micropipette, a syringe, and a spray to obtain the microcapsule of the present invention.

In the spray drying method, for example, an aqueous suspension and an aqueous polymer are mixed to prepare a dispersion, and the obtained dispersion may be sprayed and dried.
Examples of the water-based polymer include water-soluble polymers such as gum arabic, gelatin, polyvinyl pyrrolidone, polyvinyl alcohol, carboxymethyl cellulose, and methyl cellulose, and resin emulsions in which resins such as acrylic resin, polyurethane, and polyester are dispersed in water. It is done. An acrylic emulsion in which an acrylic resin is dispersed in water is preferable.

In the spray drying method, for example, an aqueous suspension and an aqueous polymer are blended in an amount of 25 to 300 parts by weight, preferably 50 to 150 parts by weight, based on 100 parts by weight of the aqueous suspension. After preparing a dispersion by mixing, the obtained dispersion can be sprayed and dried with a spray dryer to obtain the microcapsule of the present invention.
The microcapsules of the present invention thus obtained can be formulated into known dosage forms such as powders and granules. And among the interfacial polymerization method, spray drying method, insolubilization reaction method, the microcapsule of the present invention obtained by using a spray has a median diameter of, for example, 0.1 to 200 μm, preferably 1 to 200 μm. Yes, the microcapsule of the present invention obtained by using the insolubilization reaction method is a microcapsule of 1 to 5 mm when dropped using a syringe, a micropipette or the like. In addition, the microcapsule of the present invention contains 0.01 to 90% by weight, preferably 1 to 50% by weight of a pest control component. Such a microcapsule of the present invention can reduce the remaining organic solvent while exhibiting the same effect as a conventional microcapsule, and is further prepared so as not to substantially contain an organic solvent. Has been.

Therefore, although the microcapsule of the present invention depends on the components to be encapsulated, for example, when it contains an antifungal agent, it is used as a termite control agent, and when it contains an antibacterial agent, it is an industrial antibacterial agent. As such, it can be used without being limited to the use environment.
Further, the method of using the microcapsule of the present invention is not particularly limited. For example, when encapsulating an antifungal agent or fungicide, it may be sprayed on the soil by a known spraying method. More specifically, for example, Sprinkle microcapsules prepared with a concentration of the pest control component of 0.01 to 5% by weight on the soil surface at 3-5 L / m ² using a power injector or manual injector. That's fine.

(Preparation of aqueous suspension)
Production Example 1
Clothianidin (Clothianidin base: Sumika Takeda Agrochemicals) 200 parts by weight, Neucargen FS-4 (Naphthalenesulfonate sodium formaldehyde condensate: Takemoto Yushi) 20 parts by weight, Agrimer AL-10LC (alkyl vinylpyrrolidone copolymer: Carbon number of alkyl group 4: alkylation rate: about 10%: average molecular weight: about 70,000: manufactured by ISPP, 10 parts by weight, starch (made by corn: manufactured by Wako Pure Chemical Industries), 5 parts by weight, antihome E-20 (modified silicone emulsion) : Kao) 2 parts by weight, Aerosil COK84 (colloidal silicon oxide-aluminum oxide mixture: Nippon Aerosil) 10 parts by weight, Butylparaben (butyl paraoxybenzoate: Wako Pure Chemical Industries) 1 part by weight, and distilled water 752 parts by weight After mixing with a high-speed stirrer, (0.85-1 mm diameter glass beads: filling rate 80%: peripheral speed 10.5 m / s: manufactured by Shinmaru Enterprises) Got.

Production Example 2
Clothianidin (Clothianidin base: Sumika Takeda Agrochemicals) 200 parts by weight, Neucargen FS-4 (Naphthalenesulfonate sodium formaldehyde condensate: Takemoto Yushi) 20 parts by weight, Agrimer AL-10LC (alkyl vinylpyrrolidone copolymer: Carbon number of alkyl group 4: alkylation rate of about 10%: average molecular weight of about 70,000: manufactured by ISPP, 10 parts by weight, antihome E-20 (modified silicone emulsion: manufactured by Kao), 2 parts by weight, Aerosil COK84 (colloidal oxidation) After mixing 10 parts by weight of a silicon-aluminum oxide mixture (manufactured by Nippon Aerosil Co., Ltd.) and 758 parts by weight of distilled water using a high-speed stirrer, DISPERMAT (0.85-1 mm diameter zirconia beads: filling rate 80%: peripheral speed) 15.7 m / s: VMA-GETZMANN GM Wet pulverization (2 passes) using BH) to obtain an aqueous suspension containing 20% by weight of clothianidin.

Production Example 3
Clothianidin (Clothianidin base: Sumika Takeda Agricultural Chemicals) 200 parts by weight, New Calgen FS-4 (Naphthalene sulfonate sodium formaldehyde condensate: Takemoto Yushi) 20 parts by weight, Antihomer E-20 (modified silicone emulsion: Kao) ) 2 parts by weight, 10 parts by weight of Aerosil COK84 (a colloidal silicon oxide-aluminum oxide mixture: manufactured by Nippon Aerosil) and 768 parts by weight of distilled water were mixed using a high-speed stirrer, and then DISPERMAT (0.85-1 mm diameter). Zirconia beads: filling rate 80%: peripheral speed 15.7 m / s: VMA-GETZMANN GMBH) was used for wet grinding (2 passes) to obtain an aqueous suspension containing clothianidin 20 wt%.

Production Example 4
Clothianidin (Clothianidin base: Sumika Takeda Agrochemicals) 200 parts by weight, Neucargen FS-4 (Naphthalenesulfonate sodium formaldehyde condensate: Takemoto Yushi) 20 parts by weight, Agrimer AL-10LC (alkyl vinylpyrrolidone copolymer: Carbon number of alkyl group 4: alkylation rate of about 10%: average molecular weight of about 70,000: made by ISPE), 10 parts by weight of antihome E-20 (modified silicone emulsion: made by Kao), and 768 parts by weight of distilled water Are mixed using a high-speed stirrer, and then wet pulverization (2-pass) using DISPERMAT (0.85-1 mm diameter zirconia beads: filling rate 80%: peripheral speed 15.7 m / s: VMA-GETZMANN GMBH) And an aqueous suspension containing 20% by weight clothianidin was obtained.

Production Example 5
Clothianidin (Clothianidin base: Sumika Takeda Agricultural Chemicals) 200 parts by weight, New Calgen FS-4 (Naphthalene sulfonate sodium formaldehyde condensate: Takemoto Yushi) 20 parts by weight, Antihomer E-20 (modified silicone emulsion: Kao) ) After mixing 2 parts by weight and 778 parts by weight of distilled water using a high-speed stirrer, DISPERMAT (0.85-1 mm diameter zirconia beads: filling rate 80%: peripheral speed 15.7 m / s: VMA-GETZMANN Wet pulverized (2 passes) using GMBH to obtain an aqueous suspension containing clothianidin at 20% by weight.

Production Example 6
After mixing 200 parts by weight of clothianidin (original clothianidin: manufactured by Sumika Takeda Agrochemicals), 2 parts by weight of antihome E-20 (modified silicone emulsion: manufactured by Kao), and 798 parts by weight of distilled water, Aqueous suspension containing 20% by weight of clothianidin using DISPERMAT (0.85-1 mm diameter zirconia beads: filling rate 80%: peripheral speed 15.7 m / s: VMA-GETZMANN GMBH). A turbid liquid was obtained.

Production Example 7
An aqueous suspension containing 20% by weight of clothianidin was obtained in the same manner as in Production Example 2 except that Neucargen FS-4 in Production Example 2 was replaced with Emulgen 108 (manufactured by Kao).
Production Example 8
In the same manner as in Production Example 2, except that 20 parts by weight of Neukalgen FS-4 in Production Example 2 was replaced with 41 parts of Perex SS-L (manufactured by Kao) and 758 parts by weight of distilled water was replaced with 737 parts by weight of distilled water. An aqueous suspension containing 20% by weight of clothianidin was obtained.

Production Example 9
MBC (Carbendazim G: manufactured by Yakotsusho) 200 parts by weight, Newkalgen FS-4 (Naphthalenesulfonate sodium formaldehyde condensate: manufactured by Takemoto Yushi), Antihome E-20 (modified silicone emulsion: manufactured by Kao) 2 Part by weight, 10 parts by weight of Aerosil COK84 (colloidal silicon oxide-aluminum oxide mixture: made by Nippon Aerosil) and 768 parts by weight of distilled water were mixed using a high-speed stirrer, and then DISPERMAT (manufactured by 0.85-1 mm diameter zirconia). Wet grinding (2 passes) was performed using beads: filling rate 80%: peripheral speed 15.7 m / s: manufactured by VMA-GETZMANN GMBH to obtain an aqueous suspension containing 20% by weight of MBC.

Production Example 10
In the same manner as in Production Example 2, except that 20 parts by weight of Neukalgen FS-4 in Production Example 2 was replaced with 32 parts by weight of polyvinyl alcohol (Kuraray Poval 217) and 758 parts by weight of distilled water was replaced with 746 parts by weight of distilled water, An aqueous suspension containing 20% by weight clothianidin was obtained.

Production Example 11
20 parts by weight of Newkalgen FS-4 in Production Example 2 is replaced with 20 parts by weight of Newkalgen FS-4 and 32 parts by weight of polyvinyl alcohol (Kuraraypoval 217), and 758 parts by weight of distilled water is replaced with 726 parts by weight of distilled water. Except for the above, an aqueous suspension containing clothianidin in an amount of 20% by weight was obtained in the same manner as in Production Example 2.

Production Example 12
An aqueous suspension containing 20% by weight of clothianidin was obtained in the same manner as in Production Example 2 except that Neucalgen FS-4 in Production Example 2 was replaced with polyvinyl alcohol (Kuraray Poval 217).
Production Example 13
20 parts by weight of Newkalgen FS-4 in Production Example 2 is replaced with 20 parts by weight of Newkalgen FS-4 and 20 parts by weight of polyvinyl alcohol (Kuraraypoval 217), and 758 parts by weight of distilled water is replaced with 738 parts by weight of distilled water. Except for the above, an aqueous suspension containing clothianidin in an amount of 20% by weight was obtained in the same manner as in Production Example 2.

Example 1
37.7 g of ethyl acetate was added to 28.4 g of Takenate D-140N (trimethylolpropane modified isophorone diisocyanate: made by Mitsui Chemical Polyurethane) and stirred to prepare an oil phase.
Separately, the aqueous suspension obtained in Production Example 1 with respect to 11.8 g of 10% by weight polyvinyl alcohol (Kuraray Poval 217 (degree of saponification: about 87.0-89.0 mol%, degree of polymerization: 1700): manufactured by Kuraray) 37.6 g of liquid was added and stirred to prepare a first aqueous phase.

Next, the oil phase and the first aqueous phase were mixed, and the T.W. K. The mixture was stirred for several minutes using a homomixer MARKII (manufactured by Tokushu Kika Kogyo Co., Ltd.) (rotation speed: 1500 rpm) to prepare a first emulsion.
To the obtained first emulsion, 49.4 g of 10% by weight polyvinyl alcohol (Kuraray Poval 217: manufactured by Kuraray) and 16.5 g of water as a second aqueous phase were added. K. The mixture was stirred for several minutes using a homomixer MARKII (rotation speed: 1500 rpm) to prepare a second emulsion.

While gently stirring the obtained second emulsion, 2 g of diethylenetriamine (manufactured by Wako Pure Chemical Industries, Ltd.) was added dropwise and reacted in a thermostatic bath at 75 ° C. for 3 hours to obtain a microcapsule dispersion.
After the reaction, propylene glycol (freezing agent: manufactured by Asahi Glass), MP-100 (antifungal agent: 3-iodo-2-propynylbutylcarbamate: manufactured by Bayer), and Delltop (preservative) : Iodoacetamide: manufactured by Nippon Envirochemicals) and mixed.

  Next, Kunipia F (suspension aid: montmorillonite: manufactured by Kunimine Kogyo) and Rheojic 250H (thickener: sodium polyacrylate: manufactured by Nippon Pure Chemical) were blended and mixed. Then, the microcapsule containing 2.2% by weight of clothianidin was obtained by distillation under reduced pressure and removing ethyl acetate blended in the oil phase. The median diameter of the microcapsule at this time was 2.7 μm.

Example 2
T. in Example 1 K. A microcapsule having a median diameter of 6.0 μm was obtained in the same manner as in Example 1 except that the rotation speed of the homomixer MARKII was set to 1000 rpm.
Example 3
Sodium alginate (manufactured by Kibun Food Chemifa) is dissolved in water to prepare a 2 wt% aqueous sodium alginate solution. The 2 wt% aqueous sodium alginate solution and the aqueous suspension obtained in Production Example 1 are in a weight ratio of 1: 1 mixed.

Separately, calcium chloride (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in water to prepare a 1% by weight calcium chloride aqueous solution.
Using a micropipette, a syringe, and a spray, a mixture of a 2% by weight sodium alginate aqueous solution and the aqueous suspension obtained in Production Example 1 was dropped into a 1% by weight calcium chloride aqueous solution. Were used, the diameter was around 4 mm, around 2 mm, and when a spray was used, a microcapsule having a median diameter of 161 μm was obtained.

Example 4
Acrylic emulsion (Ultrasol N-203: manufactured by Gantz Kasei) and the aqueous suspension obtained in Production Example 1 were mixed at a weight ratio of 1: 3, and a spray dryer (Palvis Mini Spray GA32: manufactured by Yamato Kagaku) was mixed. ) And then microencapsulated to obtain a microcapsule having a median diameter of 4.7 μm. The spray dryer was operated at a drying chamber inlet temperature: 105 ° C., a drying chamber outlet temperature: 60 ° C .: a drying air flow rate: 0.28 m 3 / min, and an atomizing air pressure: 1 kgf / cm 2.

Example 5
Microencapsulation was performed in the same manner as in Example 4 except that the acrylic emulsion and the aqueous suspension obtained in Production Example 1 were mixed at a weight ratio of 1: 1, and a microcapsule having a median diameter of 6.8 μm was obtained. Capsules were obtained.
Example 6
Microencapsulation was performed in the same manner as in Example 4 except that the acrylic emulsion and the aqueous suspension obtained in Production Example 1 were mixed at a weight ratio of 3: 1 to obtain a microcapsule having a median diameter of 9.3 μm. Capsules were obtained.

Example 7
32.8 g of ethyl acetate was added to 24.7 g of Takenate D-140N (trimethylolpropane modified isophorone diisocyanate: made by Mitsui Chemicals Polyurethane) and stirred to prepare an oil phase.
Separately, 32.7 g of the aqueous suspension obtained in Production Example 2 was added to 10.3 g of a 10% by weight polyvinyl alcohol (Kuraray Poval 217: manufactured by Kuraray) aqueous solution and stirred to prepare a first aqueous phase. .

Next, the oil phase and the first aqueous phase were mixed, and the T.W. K. The mixture was stirred for several minutes using a homomixer MARKII (manufactured by Primex) (rotation number: 1500 rpm) to prepare a first emulsion.
To the obtained first emulsion, 42.9 g of a 10 wt% aqueous solution of polyvinyl alcohol (Kuraray Poval 217: manufactured by Kuraray) and 14.4 g of water are added as a second aqueous phase. K. The mixture was stirred for several minutes using a homomixer MARKII (rotation speed: 1500 rpm) to prepare a second emulsion.

While gently stirring the obtained second emulsion, 1.7 g of diethylenetriamine (manufactured by Wako Pure Chemical Industries, Ltd.) and 14.8 g of water are added dropwise and reacted in a thermostat at 75 ° C. for 3 hours to obtain a microcapsule dispersion. Got.
After the reaction, propylene glycol (freezing agent: manufactured by Asahi Glass), MP-100 (antifungal agent: 3-iodo-2-propynylbutylcarbamate: manufactured by Bayer), and Delltop (preservative) : Iodoacetamide: manufactured by Nippon Envirochemicals) and mixed.

  Next, Kunipia F (suspension aid: montmorillonite: manufactured by Kunimine Kogyo), Rheojic 250H (thickener: sodium polyacrylate: manufactured by Nippon Pure Chemical), and water were blended and mixed. Then, the microcapsule containing 2.6% by weight of clothianidin was obtained by distillation under reduced pressure and removing ethyl acetate mixed in the oil phase. The median diameter of the microcapsule at this time was 2.3 μm.

Example 8
A microcapsule was obtained in the same manner as in Example 7, except that the aqueous suspension obtained in Production Example 3 was used instead of the aqueous suspension obtained in Production Example 2. The median diameter of the microcapsule at this time was 2.7 μm.
Example 9
A microcapsule was obtained in the same manner as in Example 7, except that the aqueous suspension obtained in Production Example 4 was used instead of the aqueous suspension obtained in Production Example 2. The median diameter of the microcapsule at this time was 2.8 μm.

Example 10
A microcapsule was obtained in the same manner as in Example 7, except that the aqueous suspension obtained in Production Example 5 was used instead of the aqueous suspension obtained in Production Example 2. The median diameter of the microcapsule at this time was 2.4 μm.
Example 11
Implementation was performed except that polyvinyl alcohol (Kuraray Poval 117 (degree of saponification: about 98.0 to 99.0 mol%, degree of polymerization: 1700): made by Kuraray) was used instead of polyvinyl alcohol (Kuraray Poval 217: made by Kuraray). Microcapsules were obtained in the same manner as in Example 7. The median diameter of the microcapsule at this time was 4.9 μm.

Example 12
A microcapsule was obtained in the same manner as in Example 7 except that hydroxypropylmethylcellulose (Metroze 60SH-15: manufactured by Shin-Etsu Chemical Co., Ltd.) was used instead of polyvinyl alcohol (Kuraray Poval 217: manufactured by Kuraray). The median diameter of the microcapsule at this time was 18.0 μm.

Example 13
A microcapsule was obtained in the same manner as in Example 7, except that the aqueous suspension obtained in Production Example 6 was used instead of the aqueous suspension obtained in Production Example 2. The median diameter of the microcapsule at this time was 4.2 μm.
Example 14
A microcapsule was obtained in the same manner as in Example 7, except that the aqueous suspension obtained in Production Example 7 was used instead of the aqueous suspension obtained in Production Example 2. The median diameter of the microcapsule at this time was 2.1 μm.

Example 15
A microcapsule was obtained in the same manner as in Example 7, except that the aqueous suspension obtained in Production Example 8 was used instead of the aqueous suspension obtained in Production Example 2. The median diameter of the microcapsule at this time was 1.9 μm.
Example 16
Instead of the aqueous suspension obtained in Production Example 2, the aqueous suspension obtained in Production Example 10 was used, except that 10.3 g of 10% by weight polyvinyl alcohol aqueous solution was replaced with 10.3 g of distilled water. Microcapsules were obtained in the same manner as in Example 7. The median diameter of the microcapsule at this time was 2.4 μm.

Example 17
Instead of the aqueous suspension obtained in Production Example 2, the aqueous suspension obtained in Production Example 11 was used, except that 10.3 g of 10% by weight polyvinyl alcohol aqueous solution was replaced with 10.3 g of distilled water. Microcapsules were obtained in the same manner as in Example 7. At this time, the median diameter of the microcapsule was 2.2 μm.

Example 18
Instead of the aqueous suspension obtained in Production Example 2, the aqueous suspension obtained in Production Example 12 was used, and 10.3 g of 10% by weight polyvinyl alcohol aqueous solution was distilled with 3.8 g of 10% by weight polyvinyl alcohol aqueous solution. A microcapsule was obtained in the same manner as in Example 7 except that 6.5 g of water was used. The median diameter of the microcapsule at this time was 2.3 μm.

Example 19
Instead of the aqueous suspension obtained in Production Example 2, the aqueous suspension obtained in Production Example 13 was used, and 10.3 g of 10% by weight aqueous polyvinyl alcohol solution was distilled with 3.8 g of 10% by weight aqueous polyvinyl alcohol solution. A microcapsule was obtained in the same manner as in Example 7 except that 6.5 g of water was used. The median diameter of the microcapsule at this time was 2.1 μm.

Example 20
To 13.3 g of Takenate D-140N (modified trimethylolpropane of isophorone diisocyanate: made by Mitsui Chemicals Polyurethane), 52.8 g of ethyl acetate was added and stirred to prepare an oil phase.
Separately, 37.6 g of the aqueous suspension obtained in Production Example 9 was added to 11.8 g of a 10% by weight polyvinyl alcohol (Kuraray Poval 217: manufactured by Kuraray) aqueous solution and stirred to prepare a first aqueous phase. .

Next, the oil phase and the first aqueous phase were mixed, and the T.W. K. The mixture was stirred for several minutes using a homomixer MARKII (manufactured by Primex) (rotation number: 1500 rpm) to prepare a first emulsion.
To the obtained first emulsion, 49.4 g of a 10 wt% aqueous solution of polyvinyl alcohol (Kuraray Poval 217: manufactured by Kuraray) and 16.5 g of water were added as a second aqueous phase. K. The mixture was stirred for several minutes using a homomixer MARKII (rotation speed: 3000 rpm) to prepare a second emulsion.

While gently stirring the obtained second emulsion, 2 g of diethylenetriamine (manufactured by Wako Pure Chemical Industries, Ltd.) was added dropwise and reacted in a thermostatic bath at 75 ° C. for 3 hours to obtain a microcapsule dispersion.
After the reaction, propylene glycol (freezing agent: manufactured by Asahi Glass), MP-100 (antifungal agent: 3-iodo-2-propynylbutylcarbamate: manufactured by Bayer), and Delltop (preservative) : Iodoacetamide: manufactured by Nippon Envirochemicals) and mixed.

Thereafter, the mixture was distilled under reduced pressure to remove ethyl acetate blended in the oil phase to obtain a microcapsule. The median diameter of the microcapsule at this time was 1.6 μm.
Test example 1 (ant ant efficacy test)
A laboratory test was conducted by a method in accordance with the Japan Wood Preservation Association standard “Testing method and performance standards for ant protection for soil treatment and the like (JWPS-TS-S)”.

Sand loam collected from the termite habitat was screened with 20 mesh, dried, and kept at a temperature of 60 ° C. ± 2 ° C. to obtain untreated dry soil.
Separately, the microcapsules obtained in Example 1 and Examples 7 to 19 were diluted with water to adjust the clothianidin concentration to 0.05 and 0.025% by weight, and the obtained microcapsules The diluted solution (3.0 g) was added to untreated dry soil (12.0 g) and mixed to obtain treated soil.

  Two glass cylinders having an inner diameter of 5 cm and a height of 12 cm (having an opening that can be connected to a glass tube, which will be described later, about 2 cm above the bottom surface) are arranged in parallel so as to be parallel to each other at intervals in the vertical direction. At the opening, a glass tube having an inner diameter of 1.5 cm and a length of about 10 cm (there is a rubbing portion at both ends, the length of the transparent portion excluding the rubbing portion is about 5 cm, and the transparent portion is 5 mm The scales are attached at intervals.) Are connected in the horizontal direction to obtain a test container in which two glass cylinders are connected by a glass tube.

About 60 g of silica sand No. 5 adjusted to a water content of about 8% was placed in one of the glass cylinders of the test container, and about 3 g of red pine wood was placed in the other. Treated soil or untreated dry soil was packed in the transparent part at the center of the glass tube.
100 termite ants and 10 termite soldier ants were put into a glass cylinder containing silica sand No. 5 as a test vessel. The test container was allowed to stand in a temperature-controlled room at 28 ± 2 ° C. and a humidity of 70% or more for 21 days, and the condition of drilling of termites on treated soil or untreated dried soil was tested. The results are shown in Table 1, Table 2 and Table 3.

Perforation degree 0: No perforation of soil is observed.
Drilling degree 1: Drilling distance less than 1 cm Drilling degree 2: Drilling distance less than 2 cm Drilling degree 3: Drilling distance less than 3 cm Drilling degree 4: Drilling distance less than 4 cm Drilling degree 5: Drilling distance of 4 cm or more It is supposed to have ant-proof performance.

Test Example 2 (Alkali resistance of microcapsules)
The microcapsules obtained in Example 1 and Examples 7 to 19 were diluted 100 times with water, 9 ml of the obtained diluted solution was placed in a glass bottle, 3 ml of a saturated aqueous solution of calcium hydroxide was added, and the test solution and did. The test solution was allowed to stand at 40 ° C., and clothianidin in the test solution was quantified after 1 day and 7 days.

Clothianidin was quantified using high performance liquid chromatography (HPLC) after the test solution was diluted 5-fold with acetonitrile and extracted. The residual rate was calculated from the amount of clothianidin determined.
As a comparative test, a similar test was performed using an aqueous solution of clothianidin raw material. The results are shown in Table 4.

Compared with the active ingredient, the microcapsules were recognized to have superior alkali resistance, and even the solventless microcapsules using an aqueous suspension could impart alkali resistance.
Test example 3 (ant killing efficacy test)
The following tests were conducted on the microcapsules obtained in Example 3 and Examples 7 to 19.

A glass bottle containing 50 g of silica sand adjusted to a water content of about 8% is charged with 50 termites and 0.03 g of microcapsule, and the test container is kept at a constant temperature of 28 ° C. ± 2 ° C. and a humidity of 70% or more. The specimen was left in the room for 21 days, and the mortality and behavior of termites were observed. The results are shown below.
Test Example 3 Results (Death Rate)
Four days after the start of the test, the death rate was 100%, and all the microcapsules tested showed an ant killing effect.
(behavior)
In all the microcapsules tested, termite behavior slowed after 3 hours from the start of the test.

Note that termites did not show repellent response to all the microcapsules tested.
Test example 4 (mold prevention test)
The following tests were performed on the microcapsules obtained in Example 20.
(1) A potato dextrose agar (PDA) medium was prepared.
(2) The microcapsule diluted 200 times with water was immersed in a 3 cm side filter paper in the drug and air-dried.
(3) The filter paper after air drying was stuck on the PDA plate, and five kinds of mixed bacteria (Aspergillus niger, Penicillium citrinum, Cladosporium cladosporides, Aureobasidium pullans and Gliocladium virens) were sprayed.
(4) After culturing at 28 ° C. for 1 week, the degree of mold growth on the filter paper was observed with the naked eye. The results are shown in Table 5.

0: No mold growth was observed on the sample surface.
1: Slight growth of mold on the sample surface.
2: Mold growth is observed in 1/3 or less of the sample surface.
3: Mold growth is observed in 1/3 to 2/3 of the sample surface.
4: Mold growth is observed on the entire sample surface.

  The microcapsule of the present invention can be used as a termite control agent or an industrial antibacterial agent.

Claims (1)

Preparing an aqueous suspension comprising a pest control component having a saturated solubility in water at 20 ° C. of 0.5% by weight or less, and a surfactant;
A step of preparing a first emulsion by blending an oil phase containing a first film-forming component and an organic solvent having a boiling point of 130 ° C. or less and a first aqueous phase containing the aqueous suspension;
Blending the first emulsion and a second aqueous phase containing a dispersion stabilizer and water to prepare a second emulsion;
A method for producing a microcapsule, comprising: adding a second film-forming component that reacts with the first film-forming component to the second emulsified liquid; and removing an organic solvent.