Aqueous suspension agrochemical composition and method for producing same

Abstract

To provide an aqueous suspension-like agrochemical composition capable of improving stability with time of an agrochemical formulation while suppressing foaming caused by a surfactant which becomes a problem when producing the aqueous suspension-like agrochemical formulation, and to provide a method for producing the same.SOLUTION: An aqueous suspension agrochemical composition comprising (a) an agrochemical active ingredient, (b) fats and oils and fatty acids, (c) a surfactant, and (d) water, wherein the (b) fats and oils and fatty acids are at least one selected from the group consisting of fats and oils, fatty acids, and fatty acid salts having a melting point of 30 °C to 250 °C.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an aqueous suspension concentrate pesticidal composition and a method for producing the same, and more particularly to an aqueous suspension concentrate pesticidal composition in which foaming is suppressed during the production of the pesticidal composition and separation, sedimentation, etc. are suppressed even after aging, and a method for producing the same. [Background technology]

[0002] Aqueous suspension pesticide formulations (also called flowable formulations or suspoemulsion formulations) are liquid pesticide formulations in which water-insoluble or poorly soluble pesticide active ingredients are finely powdered and suspended or dispersed in water. Because this type of pesticide formulation is a heterogeneous system, phase separation and sedimentation generally occur over time, and the precipitation of the active ingredient dissolved in the dispersion medium can cause the growth of recrystallized particles and the aggregation of suspended particles. In order to prevent the sedimentation and separation of the pesticide active ingredients that can occur during storage and to improve the dispersion stability of the ingredients, various studies have been conducted on the types and amounts of additives and adjuvants such as various surfactants, thickeners, and organic solvents.

[0003] For example, a pesticide composition has been disclosed that contains a surfactant, a silicone-based antifoaming agent, and a liquid aliphatic hydrocarbon oil or glyceride oil such as olive oil or rapeseed oil, with the aim of stably suspending water-insoluble or poorly soluble pesticides in an aqueous medium without the need for environmentally harmful solvents (Patent Document 1: Japanese Patent No. 3313128). Patent Document 2 (Patent No. 3499376) discloses an aqueous suspension-type pesticide that has an objective of providing an aqueous suspension-type pesticide that has good suspension stability and redispersibility even when stored for a long period of time, and that contains a surfactant, a vegetable oil fatty acid alkyl ester, and a water-soluble polymer compound. Patent Document 3 (Japanese Patent No. 4818653) and Patent Document 4 (Japanese Patent Laid-Open Publication No. 2007-39370) disclose agricultural and horticultural aqueous suspension pesticide compositions that are intended to improve suspension stability at high temperatures and dispersibility when diluted with water, and to which kraft lignin and liquid vegetable oils such as castor oil, soybean oil, rapeseed oil, and oleic acid, or higher fatty acids derived from plants, have been added. Patent Document 5 (JP 2012-214495 A) and Patent Document 6 (JP 2007-77044 A) disclose water-suspendable pesticide formulations containing liquid pesticide components and solid pesticide components, which contain a liquid oil or fat such as soybean oil to provide formulations in which decomposition of the active ingredients is suppressed even after long-term storage, and precipitation and aggregation are also suppressed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 3313128 Publication [Patent Document 2] Patent No. 3499376 [Patent Document 3] Patent No. 4818653 [Patent Document 4] Japanese Patent Application Laid-Open No. 2007-39370 [Patent Document 5] Japanese Patent Application Laid-Open No. 2012-214495 [Patent Document 6] Japanese Patent Application Laid-Open No. 2007-77044 Summary of the Invention [Problem to be solved by the invention]

[0005] In conventional aqueous suspension pesticide formulations, it has been proposed to incorporate various surfactants, liquid oils and fats, fatty acids, etc. in order to improve the dispersion stability, sedimentation inhibition, and dilution stability of pesticide active ingredients, etc. On the other hand, silicone-based antifoaming agents are often used to suppress foaming that occurs during the production of aqueous suspension pesticide formulations due to the addition of surfactants. Issues remain, such as the high cost.

[0006] Although Patent Document 1 mentioned above discloses examples of formulations of pesticide compositions, it does not discuss the manufacturing method thereof, nor does it evaluate the stability over time or the anti-foaming effect. In Patent Document 2, the storage stability (degree of sedimentation) of the aqueous suspension pesticide prepared in the examples is evaluated, but the anti-foaming effect is not evaluated or discussed. In Patent Documents 3 and 4, the suspension stability and dispersibility in water of the aqueous suspension pesticide formulations prepared in the examples are evaluated, but the anti-foaming effect is not evaluated or discussed, and the amount of the vegetable oil etc. added to the entire composition is extremely large, at 5 to 30 mass %. Furthermore, Patent Documents 5 and 6 evaluate the decomposition rate of the pesticide ingredients in the formulation over time and the presence or absence of separation after storage of the formulation for a water-suspendable pesticide formulation produced by dissolving and emulsifying a liquid pesticide ingredient in liquid oil or fat, and then adding a solid pesticide ingredient thereto, but do not evaluate or discuss the anti-foaming effect.

[0007] An object of the present invention is to provide an aqueous suspension pesticide composition and a method for producing the same, which can improve the stability over time of the pesticide formulation while suppressing foaming caused by surfactants, which is a problem during the production of the aqueous suspension pesticide formulation. [Means for solving the problem]

[0008] The present invention covers the following [1] to

[10] . [1] An aqueous suspension pesticide composition comprising: (a) an agricultural chemical technical grade; (b) oils and fatty acids; (c) a surfactant; and (d) water, The (b) oils and fats and fatty acids are at least one selected from the group consisting of oils and fats, fatty acids and fatty acid salts, each having a melting point of 30°C to 250°C. [2] The aqueous suspension pesticide composition according to [1], wherein the (a) pesticide technical ingredient is a solid pesticide technical ingredient having a solubility in water of 1000 ppm or less at 25°C and a melting point of 60°C or higher. [3] The pesticide composition according to [1], wherein the (b) oils and fatty acids are contained in an amount of 0.01 to 5% by mass relative to the total mass of the pesticide composition. [4] The pesticide composition according to [1], wherein the (b) oils and fats and fatty acids are hydrogenated castor oil. [5] The pesticidal aqueous suspension concentrate according to [1], which has a median diameter (D50) of 50 μm or less as determined by a laser diffraction scattering method. [6] The aqueous suspension pesticide composition according to [1], which is a flowable formulation for pesticides. [7] The pesticidal aqueous suspension concentrate according to [1], wherein the pesticidal aqueous suspension concentrate has a dispersed phase concentration of 1 to 50% by mass and does not form a hard cake even after storage at 54°C for 14 days. [8] A method for producing an aqueous suspension concentrate pesticide composition, comprising: The method includes a step of wet-grinding a mixture containing an agricultural chemical technical grade, oils and fats, fatty acids, a surfactant, and water (excluding an embodiment in which the oils and fats and fatty acids are added after the wet-grinding step), The wet-grinding step is a step of simultaneously wet-grinding the agricultural chemical technical product, the oils and fats, the fatty acids, and the surfactant, The fats and oils and fatty acids are selected from fats and oils, fatty acids and fatty acid salts having a melting point of 30°C to 250°C. At least one selected from the group consisting of A method for producing an aqueous pesticide suspension. [9] The method for producing an aqueous suspension concentrate pesticidal composition according to [8], wherein the oils and fatty acids before wet-milling have an average particle size of 1 cm or less.

[10] The method includes a step of wet-grinding a mixture containing an agricultural chemical technical grade, oils and fats, fatty acids, a surfactant, and water (excluding an embodiment in which the oils and fats and fatty acids are added after the wet-grinding step), A method for suppressing foaming during the production of an aqueous pesticide suspension. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide an aqueous suspension pesticide composition that is inhibited from separating, settling, etc. over time and that is inhibited from foaming when diluted and shaken before use. Furthermore, the present invention can provide a method for producing an aqueous pesticidal suspension concentrate, which can suppress foaming, which is a problem during production. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 shows the change over time in backscattered light (%) of the aqueous suspension concentrate pesticide composition of Example 3, measured using a solution stability evaluation device, Stability Tester ST-1 (14 days at 54°C, (a) 12-hour intervals, (b) 48-hour intervals). [Figure 2] FIG. 2 shows the change over time in backscattered light (%) of the aqueous suspension concentrate pesticide composition of Comparative Example 4, measured using a solution stability evaluation device, Stability Tester ST-1 (14 days at 54°C, (a) 12-hour intervals, (b) 48-hour intervals). DETAILED DESCRIPTION OF THE INVENTION

[0011] Foaming caused by the incorporation of surfactants can be a problem during the production of aqueous suspension pesticide formulations, for example, during grinding using a bead mill, or during dilution and shaking when using the pesticide formulation. For example, foaming during production can cause delays in the production process, such as reduced grinding efficiency, overflow from the grinding device, or difficulty in checking the formulation's condition (dispersibility, etc.) until the foam subsides. Furthermore, when using the pesticide formulation, foaming caused by diluting or shaking the formulation in a spray container can cause the formulation to overflow from the spray container, making spraying difficult. To address this foaming problem, the use of silicone-based antifoaming agents has been considered, but these agents are expensive and other problems may arise, such as the fact that the silicone compounds used are not registered (and therefore cannot be used) in some countries. In response to the problem of foaming in aqueous suspension pesticide formulations and the need for silicone-free antifoaming agents, the present inventors have discovered that by blending powdered or granular oils and fats or fatty acids that are solid at room temperature with a surfactant, foaming can be suppressed (foam suppression effect), thereby solving the above problems, and that the dispersion stability and redispersibility required of aqueous suspension pesticide formulations can be ensured. Furthermore, they have discovered that by subjecting these powdered or granular oils and fats or fatty acids to a mixing and grinding (dispersion) process together with pesticide active ingredients and surfactants, the problem of foaming in aqueous suspension pesticide formulations during manufacturing can be solved. Because aqueous suspension pesticide formulations are sprayed onto fields during use, the use of oils and fatty acids can also be considered beneficial from the perspective of environmental impact. As shown in the aforementioned patent documents, there have been proposals to incorporate liquid oils (vegetable oils, etc.) and fatty acid esters into aqueous suspension pesticide formulations to improve dispersion stability, but these proposals are limited to evaluating the dispersion stability of the pesticide formulations, and the amounts of liquid oils and fatty acid esters incorporated are very large. Furthermore, these proposals have not verified the suppression of foaming, and there has been no verification or discussion whatsoever about the suppression of foaming in formulations by incorporating liquid oils and fatty acid esters. Furthermore, as will be shown in the examples below, when liquid oils and fatty acid esters are used, the components settle over time, forming a hard cake. It has been confirmed that even when mixed upside down, the mixture does not become uniform. The present invention will be described in detail below.

[0012] The aqueous suspension concentrate pesticide composition of the present invention contains (a) an agrochemical product, (b) fats and oils and fatty acids, (c) a surfactant, and (d) water, and may further contain an adjuvant such as a thickener as other components.

[0013] Although there is no strict definition of the "aqueous suspension pesticide (composition / formulation)" that is the subject of this invention, it can generally be considered as a general term for a suspension pesticide formulation in which the solvent is mainly water and the solid active ingredient (pesticide) is dispersed. Aqueous suspension pesticide compositions (formulations) can be broadly classified into flowable formulations and suspoemulsion formulations, and the present invention can cover both formulations. A flowable formulation is a suspension of solid pesticide raw materials that are insoluble or poorly soluble in water, and is used by diluting with water or spraying the undiluted solution. A suspoemulsion formulation is a formulation in which a water-insoluble solid pesticide active ingredient is suspended in water, and an emulsion containing a water-insoluble liquid pesticide active ingredient (oil active ingredient) is added, dispersing both the solid and liquid active ingredients in a single solvent (water).

[0014] (a) Pesticide active ingredients The pesticide (a) to be incorporated into the pesticide aqueous suspension concentrate of the present invention is not particularly limited, and any pesticide generally used as a pesticide, such as a herbicide, insecticide, fungicide, or plant growth regulator, can be used.

[0015] Among the above-mentioned agricultural chemical raw materials, examples of herbicides include phenoxy acid-based, carbamate-based, acid amide-based, acetanilide-based, urea-based, sulfonylurea-based, pyrimidyloxybenzoic acid-based, triazine-based, diazine-based, diazole-based, bipyridylium-based, dinitroaniline-based, aromatic carboxylic acid-based, imidazolinone-based, fatty acid-based, organophosphorus-based, amino acid-based, diphenyl ether-based, nitrile-based, cyclohexanedione-based, phenylphthalimide-based, cineole-based, indandione-based, benzofuran-based, triazolopyrimidine-based, oxazinone-based, allyltriazolinone-based, isourazole-based, pyrimidinylthiophthalide-based, triazolinone-based, inorganic herbicides, and biological pesticides. Examples of insecticides include organophosphate, carbamate, pyrethroid, benzoylhydrazide, neonicotinoid, triazine, thiourea, oxadiazine, phenylpyrazole, nereistoxin, and benzoylphenylurea insecticides, natural insecticides, biological pesticides, acaricides, and nematicides. Examples of fungicides include inorganic coppers, organic coppers, inorganic sulfur agents, organic sulfur agents, organophosphorus, benzimidazole, dicarboximide, acid amide, triazole, thiazole, imidazole, piperazine, methoxyacrylate, oxazolidinedione, strobilurin, anilinopyrimidine, dithiolane, quinoxaline, aminopyrimidine, phenylpyrrole, triazine, cyanoacetamide, and guanidine fungicides, antibiotic fungicides, natural product fungicides, and biological pesticides. Examples of plant growth regulators include ethylene-based, auxin-based, cytokinin-based, and gibberellin-based compounds. These agricultural chemicals may be used singly or in combination of two or more.

[0016] The agricultural chemical raw material (a) used in the present invention may be a substance that is solid at room temperature and is poorly soluble or insoluble in water. For example, the agricultural chemical raw material may have a solubility in water of 1000 ppm or less at 25°C and a melting point of 60°C or higher. When the aqueous suspension concentrate pesticidal composition of the present invention is in the form of the suspoemulsion formulation described above, other liquid active ingredients such as liquid active ingredients can be used in addition to the pesticidal active ingredient (a) (solid) in order to expand the range of application of the pesticide or to enhance its efficacy.

[0017] In the aqueous suspension concentrate pesticide composition of the present invention, the content of (a) the pesticide active ingredient can be 1 to 50 mass % relative to the total mass of the aqueous suspension concentrate pesticide composition, and can also be, for example, 10 to 40 mass %, or 10 to 30 mass %. The shape and size of the (a) agricultural chemical technical ingredient are not particularly limited as long as it is in an embodiment that can suppress precipitation in the aqueous suspension pesticide composition and maintain dispersion stability. For example, it can have a size of about 0.5 μm to 1000 μm, 1 μm to 800 μm, 1 μm to 500 μm, 1 μm to 100 μm, or 1 μm to 50 μm.

[0018] (b) Fats, oils and fatty acids The (b) oils and fatty acids to be blended in the pesticidal aqueous suspension concentrate of the present invention are at least one selected from the group consisting of oils and fatty acids, fatty acids and fatty acid salts, each having a melting point of 30°C to 250°C. Component (b) having the above melting point is generally a substance that is solid at room temperature, and for example, granular or powdery component (b) can be suitably used. The (b) fats and oils and fatty acids may be selected from the group consisting of fats and oils, fatty acids and fatty acid salts, preferably having a melting point of 50°C to 150°C, more preferably 60°C to 100°C.

[0019] Specific examples of component (b) include, for example, vegetable oils and animal oils with a melting point of 30°C to 250°C, and processed oils and fats thereof (hydrogenated oils, interesterified oils, etc.). Specific examples include, but are not limited to, vegetable hydrogenated oils such as hydrogenated castor oil, palm hydrogenated oil, hydrogenated soybean oil, hydrogenated rapeseed oil, hydrogenated jojoba oil, hydrogenated peanut oil, hydrogenated sunflower oil, hydrogenated safflower oil, hydrogenated olive oil, and hydrogenated cottonseed oil, as well as their extremely hydrogenated oils (hydrogenated vegetable oils and extremely hydrogenated vegetable oils), and animal hydrogenated oils such as beef tallow hydrogenated oil and lard hydrogenated oil, as well as their extremely hydrogenated oils (hydrogenated animal oils and extremely hydrogenated animal oils). Examples of fatty acids and fatty acid salts having a melting point of 30°C to 250°C include, but are not limited to, fatty acids and hydroxy fatty acids having 12 to 26 carbon atoms, such as lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, hydroxystearic acid, behenic acid, and montanic acid, as well as mixtures of the above fatty acids, including lanolin fatty acid; and fatty acid salts, such as calcium salts, magnesium salts, zinc salts, and aluminum salts of the above fatty acids and hydroxy fatty acids. These oils and fatty acids can be used singly or in combination of two or more. Among these, hydrogenated castor oil (melting point 78 to 90° C.) can be preferably used as component (b).

[0020] The shape and size of (b) oils and fatty acids are not particularly limited as long as they are capable of suppressing precipitation in the aqueous suspension pesticide composition and maintaining dispersion stability. For example, they may have a size of about 0.5 μm to 1000 μm, 1 μm to 800 μm, 1 μm to 500 μm, 1 μm to 100 μm, or 1 μm to 50 μm. As will be described later, in the production of the aqueous suspension concentrate pesticidal composition, the efficiency of wet grinding can be improved by using component (b) that has been previously ground into granules or powder having a size of approximately 1 cm or less.

[0021] In the pesticidal composition of the present invention, the content of (b) oils and fats and fatty acids is The content of the surfactant is preferably 0.01 to 5 mass % relative to the total mass of the pesticidal suspension concentrate, more preferably 0.1 to 5 mass %, and most preferably 0.5 to 3 mass %. Alternatively, the blending amount of the (b) oils and fatty acids in the aqueous suspension concentrate pesticidal composition can be set to a mass ratio of (a) pesticidal technical materials:(b) oils and fatty acids=1:0.01 to 1:1 relative to the blending amount of the above-mentioned (a) pesticidal technical materials, or can be set to a mass ratio of (b) oils and fatty acids:(c) surfactant=1:1.5 to 1:100 relative to the blending amount of the below-mentioned (c) surfactant.

[0022] (c) Surfactants The surfactants used in the pesticidal aqueous suspension concentrate of the present invention include nonionic surfactants, anionic surfactants, cationic surfactants and amphoteric surfactants. For example, nonionic surfactants include polyoxyalkylene alkyl ethers, polyoxyalkylene fatty acid esters, polyoxyethylene sorbitan esters, polyoxyethylene sorbitol fatty acid esters, polyoxyethylene resin acid esters, polyoxyalkylene glycols, polyoxyalkylene styryl (1 to 3 mol) phenyl ethers, polyoxyalkylene alkylaryl ethers, polyoxyalkylene castor oil ethers, sorbitan fatty acid esters, polyoxyethylene alkylamines, polyoxyalkylene hydrogenated castor oil ethers, polyhydric alcohol fatty acid esters, and polyoxyethylene polyhydric alcohol fatty acid esters. Examples of anionic surfactants include polyoxyalkylene alkyl sulfates, alkyl sulfates, (mono- and di-)alkyl sulfosuccinates, alkylbenzene sulfonates, polyoxyalkylene alkylaryl ether sulfates, polyoxyalkylene styryl (1 to 3 mol) phenyl ether sulfates, fatty acid salts (excluding those having a melting point of 30°C to 250°C), fatty acid alkyl taurines, polyoxyalkylene alkyl ether phosphates, polyoxyalkylene alkylaryl ether phosphates, alkyl phosphates, polyoxyalkylene styryl (1 to 3 mol) phenyl ether phosphates, polycarboxylates, turmeric oil, and polyalkylene glycol sulfates. Examples of cationic surfactants include alkyltrimethylammonium chloride and benzalkonium chloride. Examples of amphoteric surfactants include carboxybetaine salts (dialkylaminoethylbetaine, alkylbetaine, etc.), 2-alkylimidazoline derivatives, glycine types, and amine oxide types. These surfactants can be used alone or in combination of two or more.

[0023] In the aqueous suspension concentrate pesticidal composition of the present invention, the content of (c) the surfactant is preferably 1 to 20 mass % relative to the total mass of the aqueous suspension concentrate pesticidal composition, more preferably 1 to 15 mass %, and most preferably 2 to 10 mass %.

[0024] 〈(d)Water〉 The pesticidal composition of the present invention contains water as a solvent. The content of water in the pesticidal composition of the present invention (100% by mass) can be the remainder excluding the total amount of the components (a) to (c) and other adjuvants described below. The pesticidal aqueous suspension concentrate of the present invention may contain an aqueous solvent other than water, as long as the effect of the pesticidal composition is not impaired.

[0025] <Other adjuvants, etc.> The pesticidal aqueous suspension concentrate of the present invention may contain, as needed, additives such as thickeners (such as water-soluble polymers), antifreezing agents, preservatives, antifoaming agents, pH adjusters, specific gravity adjusters, antioxidants, and ultraviolet protection agents. Other active ingredients such as auxiliaries and fertilizers may also be added. Furthermore, as described above, when the aqueous suspension concentrate pesticidal composition of the present invention is in the form of a suspoemulsion formulation, other liquid active ingredients such as liquid concentrates can be used to expand the range of pesticide application or to enhance efficacy.

[0026] The thickener forms a three-dimensional network structure within the suspension, which can affect the flow and deformation (rheological properties) when force is applied, and can contribute to adjusting the dispersibility and sedimentation of dispersed microparticles, as well as the dischargeability when the pesticide composition is sprayed. Examples of thickeners include water-soluble polymers such as starch, dextrin, sodium alginate, carrageenan, locust bean gum, guar gum, tara gum, welan gum, tamarind gum, gum arabic, tragacanth gum, karaya gum, pectin, xanthan gum (xanthan gum), pullulan, arabinogalactan, cellulose, methyl cellulose, ethyl cellulose, carboxymethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, polyvinyl alcohol, polyacrylic acid and its salts, polyacrylamide-based water-soluble polymers, casein, and gelatin; nonionic thickeners such as polyalkylene oxide; and inorganic thickeners such as bentonite, hectorite, white carbon, and silica. These thickeners can be used alone or in combination of two or more. When the aqueous suspension concentrate pesticidal composition of the present invention contains a thickener, the content thereof is preferably 0.05 to 5 mass %, more preferably 0.05 to 3 mass %, and most preferably 0.1 to 1 mass %, relative to the total mass of the aqueous suspension concentrate pesticidal composition.

[0027] Examples of antifreeze agents include ethylene glycol, propylene glycol, glycerin, etc. The glycols also have properties as polar solvents and are sometimes classified as solvents. When the aqueous suspension concentrate pesticidal composition of the present invention contains an antifreeze agent, the content thereof is preferably 0.01 to 10 mass %, more preferably 0.1 to 10 mass %, or 1 to 10 mass %, and most preferably 3 to 7 mass %, relative to the total mass of the aqueous suspension concentrate pesticidal composition.

[0028] Examples of preservatives include sorbic acid, potassium sorbate, p-chloro-metaxylenol, butyl p-oxybenzoate, and benzisothiazolinone compounds such as 1,2-benzisothiazol-3(2H)-one and 5-chloro-2-methyl-4-isothiazolin-3-one. When a preservative is used in the pesticidal aqueous suspension concentrate of the present invention, it can be used, for example, preferably in a proportion of 1 mass % or less, more preferably in a proportion of 0.1 to 1.0 mass %, and most preferably in a proportion of 0.2 to 0.7 mass %, relative to the total mass of the pesticidal aqueous suspension concentrate.

[0029] As the defoaming agent to be incorporated into the aqueous suspension pesticide composition, the above-mentioned silicone-based defoaming agents (e.g., dimethylpolysiloxane, etc.) are generally used, but nonionic defoaming agents and higher alcohols can also be used. In the present invention, (b) fats and oils and fatty acids are used for the purpose of using a silicone-free antifoaming agent, but silicone-based antifoaming agents or other antifoaming agents may also be used within the scope that does not impair the effects of the present invention.

[0030] <Average particle size: Median diameter (D50)> The pesticidal aqueous suspension concentrate of the present invention preferably has a median particle diameter (D50) of 50 μm or less when measured by a laser diffraction scattering method. The diameter (D50) of the particles is preferably 30 μm or less, and most preferably 5 μm or less. The median diameter (D50) is the particle diameter at which the particle concentration (volume concentration) measured by laser diffraction scattering is 50% cumulatively, and in the aqueous suspension pesticidal composition of the present invention, the dispersed phase measured as the median diameter (D50) is composed of (a) the pesticide active ingredient and (b) oils and fatty acids. For the measurement, a laser diffraction particle size distribution analyzer SALD-2300 (measurement principle: laser diffraction, cell: batch cell) manufactured by Shimadzu Corporation can be used.

[0031] The aqueous suspension concentrate pesticide composition of the present invention is a composition in which separation, sedimentation, etc. are suppressed even after aging, and even after aging, for example, after storage at 40°C for 28 days or after storage at 54°C for 14 days, the composition can have a median diameter (D50) measured by laser diffraction scattering method of 50 μm or less, more preferably 30 μm or less, and most preferably 5 μm or less. Furthermore, the aqueous suspension concentrate pesticide composition of the present invention can have particle size stability, such that the ratio of the median diameter (D50) before and after storage at 40°C for 28 days [D50 after storage / D50 before storage] is preferably 3 or less.

[0032] <Stability over time: Formation of hard cakes> As described above, the aqueous suspension pesticidal composition of the present invention is a composition in which separation, sedimentation, etc. are suppressed even after aging, and the presence or absence of the formation of a hard precipitate known as a hard cake (a precipitate that does not redisperse even when inverted and mixed) after a predetermined period of storage can be evaluated as an indicator of stability over time. That is, in one embodiment, a redispersible aqueous suspension concentrate pesticide composition can be obtained in which the concentration of the dispersed phase is 1 to 50 mass %, and which does not form a hard cake even after storage at 54°C for 14 days.

[0033] Note that even if a precipitate appears to have formed after a predetermined period of storage, it does not necessarily mean that the precipitate is a hard cake. That is, the presence or absence of hard cake formation can be evaluated by whether the precipitate can be redispersed, and can be evaluated, for example, by the following procedure. First, 20 mL of the aqueous suspension pesticide composition is placed in a glass bottle (e.g., 27 mm in diameter, 55 mm in height), sealed, and stored at 54°C for 14 days. At this time, the concentration of the dispersed phase of the aqueous suspension pesticide composition is adjusted to 1 to 50% by mass; for example, the total concentration of (a) the pesticide active ingredient and (b) the oils and fatty acids is adjusted to about 20% by mass. After storage, the glass bottle is inverted and mixed, and the number of inversions required until re-dispersion (no visible precipitate) is achieved is counted. Note that one round of inversion of the glass bottle is counted as one inversion. If the number of inversions required for redispersion is less than 50 (49 or less), it can be evaluated as not forming a hard cake (being redispersible). In other words, in consideration of the use of the aqueous suspension concentrate pesticide composition, the number of inversions is preferably less than 50, more preferably less than 20, and even more preferably less than 10.

[0034] <Stability over time: formulation separation rate> The stability over time of the pesticidal aqueous suspension concentrate of the present invention can also be evaluated by the formulation separation rate (see below), which is calculated as the rate of change in the sedimentation rate of the dispersed phase of the composition before and after storage for a specified period of time. The evaluation of the separation rate of the formulation can be carried out using a solution stability evaluation device, Stability Tester ST-1, manufactured by Eiko Seiki Co., Ltd. The Stability Tester ST-1 is a device that can measure backscattered light and transmitted light by irradiating light onto a sample in a sample tube. The light source and detector move up and down along the sample tube, scanning the amount of light at a minimum pitch of 5 μm. By repeating this scan at any time interval, it is possible to measure minute changes in the amount of light due to particle movement or changes in particle shape within the sample. do.

[0035] Specifically, 20 mL of the aqueous suspension pesticide composition is placed in a stability tester sample tube (diameter 27.5 mm, height 72.5 mm) and sealed, which is then placed in the measurement section of the Stability Tester ST-1, and backscattered light is measured every 3 to 6 hours at 40°C for 28 days (or alternatively at 54°C for 14 days). The concentration of the dispersed phase ((a) pesticide technical grade + (b) oils and fatty acids) of the aqueous suspension pesticide composition used in the backscattered light measurement can be 1 to 50% by mass; for example, as in the evaluation of the presence or absence of hard cake formation (evaluation of redispersibility), the total concentration of (a) pesticide technical grade and (b) oils and fatty acids can be adjusted to around 20% by mass. Scanning is performed from the top to the bottom of the sample tube, and the position (mm) where the backscattered light has decreased by 80% or more is taken to be the interface between the suspension phase (the phase where the dispersed phase has settled) and the supernatant phase, and the distance from the bottom of the sample tube (0 mm) to this interface is measured as the interface position (mm).The formulation separation rate is calculated using the following formula from the interface position (mm) at the start of the measurement (initial) and the interface position (mm) after the passage of time (during the test). Formulation separation rate (%) = 100 - [interface position (mm) after time has passed (during the test) / interface position (mm) at the start of measurement (initial)] × 100

[0036] Considering the practical use of the aqueous suspension pesticide composition, it is desirable that the formulation separation rate is 80% or less, and more preferably, 60% or less, or 50% or less, before and after 28 days of storage at 40° C. Note that the sedimentation phase evaluated as the formulation separation rate includes both redispersible precipitates and non-redispersible precipitates (hard cake).

[0037] <Foaming suppression> As described above, the pesticidal aqueous suspension concentrate of the present invention is also a composition that is inhibited from foaming when diluted and shaken. Foaming suppression can be evaluated by the following procedure. Specifically, 1 mL of the aqueous suspension concentrate pesticide composition is poured into a 100 mL measuring cylinder (3.2 cm diameter, 25 cm height) containing 100 mL of pure water or 19.2°C hard water at 20°C, and the measuring cylinder is sealed. The measuring cylinder is then inverted and mixed 30 times, and the height of foam above the liquid surface is measured. Note that in the inverted mixing, one reciprocal up-and-down inversion of the measuring cylinder is counted as one count (one rotation). The concentration of the dispersed phase of the aqueous suspension concentrate pesticide composition used in this evaluation (inverted mixing) can be 1 to 50% by mass. For example, similar to the evaluation of hard cake formation (evaluation of redispersibility) described above, the total concentration of (a) the pesticide technical ingredient and (b) the oils and fatty acids can be adjusted to around 20% by mass. If the height of foam from the liquid surface is 5.0 cm or less, the aqueous suspension concentrate pesticide composition can be evaluated as suitable for use without overflowing from the spray container when actually used.

[0038] <viscosity> The aqueous suspension concentrate pesticidal composition of the present invention is desirably formulated by adjusting the viscosity of the composition to fall within a specific range. For example, the viscosity (25°C) of the aqueous suspension concentrate pesticidal composition at the time of preparation can be preferably 10 mPa·s to 100 mPa·s, more preferably 20 mPa·s to 100 mPa·s, and most preferably 30 mPa·s to 95 mPa·s. If the viscosity at the time of preparation is too low, there is a risk that the dispersion stability (suspension stability) of the composition will gradually deteriorate, while if the viscosity at the time of preparation is too high, there is a risk that it will take a long time to discharge the composition from the spray container when used.

[0039] <Method for producing aqueous suspension pesticide composition> The aqueous suspension concentrate pesticidal composition according to the present invention is produced by wet-pulverizing a mixture containing an agrochemical technical product, oils and fats, fatty acids, a surfactant, and water. The embodiment in which fats and oils and fatty acids are added after step (2) is excluded. The embodiment is characterized in that fats and oils and fatty acids are subjected to the wet grinding step simultaneously with the agricultural chemical raw materials and surfactant.

[0040] An example of the method for producing the pesticidal aqueous suspension concentrate according to the present invention will be shown below, but the method is not limited thereto. The pesticide technical ingredient, which has been previously pulverized to about 5 to 50 μm using a dry pulverizer such as a hammer mill or Jet-Oh-Myser, is mixed with fats and oils, fatty acids, surfactants, a solvent (water), and, if necessary, adjuvants such as antifreeze agents and thickeners, and the mixture is then finely pulverized using a wet pulverizer such as a sand grinder, Dynomill, or colloid mill filled with media such as glass beads, zirconia beads, or alumina beads. The beads (media) are removed from the resulting wet-pulverized solution, and, if necessary, water or a mixture of water and a separately prepared adjuvant such as a thickener or antifreeze agent is added, followed by uniform mixing and viscosity adjustment to obtain the aqueous suspension pesticide composition of the present invention. In order to improve the efficiency of the grinding, the fats and oils and fatty acids to be subjected to wet grinding are preferably ground into granules or powder having a size of about 1 cm or less, for example, about 500 μm, as described above.

[0041] The present invention also relates to a method for suppressing foaming during the production of an aqueous suspension pesticide composition, which method comprises a step of wet-grinding a mixture containing an agrochemical active ingredient, oils and fats, fatty acids, a surfactant, and water (excluding an embodiment in which the oils and fats and fatty acids are added after the wet-grinding step). [Example]

[0042] The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples in any way. Unless otherwise specified, % shown below represents % by mass.

[0043] [Preparation of thickener aqueous solution (KELZAN 1% aqueous solution)] The aqueous thickener solution (1% aqueous solution of KELZAN) used in the "Preparation of aqueous pesticide suspension formulations" described below was prepared by mixing 490 g of purified water, 5 g of KELZAN (xanthan gum (thickener), Sansho Co., Ltd.), and 5 g of Proxel GXL(S) (1,2-benzisothiazol-3(2H)-one (preservative), SC Johnson) using a homogenizer (ED-7, manufactured by Nippon Seiki Co., Ltd.) at 1,000 rpm for 20 minutes.

[0044] [Examples 1 to 13, Comparative Examples 1 to 5] [Preparation of aqueous suspension pesticide composition] The specified amounts of the agricultural chemical active ingredients (A-C), surfactants (A-C), solvent (pure water), antifreeze (propylene glycol), and oils, fats, and fatty acids (A-J) or silica listed in Table 2 (column (1)) were charged into the vessel (grinding container: Vessel 01, 120 mL capacity (bottom diameter 50 mm, height 90 mm)) of a batch bead mill (Easy Nano RMB II, manufactured by Imex Co., Ltd.), and an equal volume of glass beads (diameter 1.0-1.4 mm) was added. Wet grinding was carried out (2750 rpm, 30 minutes). Immediately after grinding, the amount of foam in the vessel was measured (see below). The beads were filtered out from the obtained wet-milled solution, and the solvent (pure water) and thickener aqueous solution (KELZAN 1% aqueous solution) shown in Table 2 (column (2)) were added thereto to adjust the sample concentration, thereby obtaining an aqueous suspension pesticide composition. The obtained aqueous suspension concentrate pesticidal composition was subjected to various evaluations according to the evaluation methods described below.

[0045] The components incorporated in the aqueous suspension pesticide compositions of the Examples and Comparative Examples are shown in [Table 1-1] to [Table 1- 4] is shown. The particle sizes of the oils and fatty acids shown in Table 1-2 were measured using the following procedure. First, 10 g of a 1% aqueous solution of surfactant (Aerorol CT-1L, manufactured by Toho Chemical Industry Co., Ltd.) was added to 0.1 g of these oils and fatty acids, followed by 10 minutes of ultrasonic treatment. The average particle size (median diameter (D50): μm) of this sample was measured using a laser diffraction particle size distribution analyzer (SALD-2300, manufactured by Shimadzu Corporation) in the absorbance range of 0.04 to 0.20. [Table 1] [Table 2] [Table 3] [Table 4]

[0046] [Evaluation method] The aqueous suspension concentrate pesticide compositions prepared in Examples 1 to 13 and Comparative Examples 1 to 5 were evaluated for stability over time, foaming, etc., according to the following procedures. The results are shown in Table 3.

[0047] (1) Presence or absence of hard cake (storage stability of aqueous suspension pesticide composition) [Evaluation of hard cake formation] A glass bottle (diameter 27 mm, height 55 mm) containing 20 mL of each of the aqueous suspension concentrate pesticide compositions of Examples 1 to 13 and Comparative Examples 1 to 5 was sealed and stored at 54°C for 14 days. After storage, the sample (glass bottle) was inverted and mixed, and the presence or absence of hard cake formation was evaluated based on the number of inversions required until redispersion (one round of inversion up and down was counted as one inversion). Evaluation Criteria The number of inversions required for redispersion was 50 or more: × (hard cake present) The number of inversions required for redispersion was 20 to 49: △ (no hard cake) Number of inversions required for redispersion: 10-19: Yes (no hard cake) Number of inversions required for redispersion: 1 to 9 times: ◎ (no hard cake)

[0048] (2) Foam height during grinding In the above [Preparation method for flowable formulation], immediately after wet grinding (2750 rpm, 30 minutes), the vessel was removed from the apparatus, and the distance from the top of the vessel to the foam of the formulation was measured and recorded as [Measured value]. Before pulverization, the distance from the top of the vessel to the charged components (slurry) was measured (6.0 cm in both cases), and the foam height during pulverization was calculated using the following formula. When crushed, foam height = 6.0 cm - [measured value] (cm)

[0049] (3) Formulation separation rate The separation rate of the formulation was evaluated using a solution stability evaluation device, Stability Tester ST-1, manufactured by Eiko Seiki Co., Ltd.

[0050] 20 mL of each aqueous suspension pesticide composition of Examples 1 to 13 and Comparative Examples 1 to 5 was weighed out and placed in a stability tester sample tube (diameter 27.5 mm, height 72.5 mm), which was then placed in the solution stability evaluation device. Test conditions: Backscattered light (870 nm) was measured every 3 to 6 hours from the top to the bottom (55 mm) of the sample tube at 5.5 μm intervals for 28 days at 40°C or 14 days at 54°C. The position (mm) where the backscattered light decreased by 80% or more was considered to be the interface between the suspension phase (phase where the dispersed phase has settled) and the supernatant phase of the formulation, and the distance from the bottom of the sample tube (0 mm) to this interface was defined as the interface position (mm).The formulation separation rate was calculated using the interface position (mm) at the start of measurement (initial) and the interface position (mm) after the passage of time (during the test) using the following formula. Formulation separation rate (%) = 100 - [interface position (mm) after time has passed (during the test) / interface position (mm) at the start of measurement (initial)] × 100

[0051] Figures 1 and 2 show the change over time in backscattered light (%) measured for the aqueous suspension concentrate pesticide compositions of Example 3 and Comparative Example 4 under test conditions of 54°C for 14 days. In Figures 1 and 2, the horizontal axis corresponds to the height of the sample tube (50 mm at the right end is the top of the sample tube, and 0 mm at the left end is the bottom of the sample tube), and the vertical axis corresponds to scattered light intensity (%). The scattered light intensity (%) changes as the particle concentration increases or decreases. Figures 1(a) and 2(a) show data at 12-hour intervals, and Figures 1(b) and 2(b) show data at 48-hour intervals. As shown in Figure 1, in Example 3, the scattered light intensity (%) decreased slightly over time throughout the sample, indicating that some slight particle size growth occurred throughout the sample. However, compared to Figure 2, which will be described later, the decrease in scattered light intensity in the upper layer of the sample was smaller, and it can be said that sample sedimentation was suppressed. On the other hand, as shown in FIG. 2, in Comparative Example 4, the scattered light intensity (%) in the upper layer of the sample decreased significantly over time, which corresponds to the occurrence of sedimentation of the sample.

[0052] <Measurement conditions> Equipment: Eiko Seiki Co., Ltd. Solution stability evaluation equipment Stability Tester ST-1 Measurement method: Optical multiple scattering method (backscattered light) Measurement conditions: (1) 40°C, 28 days, (2) 54°C, 14 days Measurement interval: 3 to 6 hours (Figures 1 and 2 show results at 12-hour and 48-hour intervals) Light source wavelength: 870nm Sample volume: 20 mL

[0053] (4) Dilution stability (foam height (cm), sedimentation volume (mL)) (4-1) Foaming during initial dilution and dispersion 100 mL of pure water or 19.2°C hard water was placed in a 100 mL measuring cylinder (diameter 3.2 cm, height 25 cm), and while the temperature was maintained at 20°C in a constant temperature water bath, 1 mL of each of the aqueous suspension pesticide compositions of Examples 1 to 13 and Comparative Examples 1 to 5 was added and the cylinder was sealed. After 30 cycles of inversion mixing, the foam height (height of foam at initial dilution dispersion) (cm) from the liquid surface immediately after inversion mixing was measured. (4-2) Sedimentation amount after 120 minutes The samples used to evaluate foaming during initial dilution and dispersion (each aqueous suspension pesticide composition and a measuring cylinder containing pure water or hard water) were left to stand at 20°C for 120 minutes, and the amount of sedimentation (mL) after standing was measured.

[0054] (5) Stability over time (average particle size (median diameter: D50)) 0.05 g of each of the aqueous suspension pesticide compositions of Examples 1 to 13 and Comparative Examples 1 to 5 was diluted and dispersed by adding 10 g of pure water, and the average particle size (median diameter (D50): μm) of each sample was measured using a laser diffraction particle size distribution analyzer manufactured by Shimadzu Corporation in the absorbance range of 0.04 to 0.20. Measurements were carried out immediately after sample preparation (initial stage) and after 28 days at 40°C. <Measurement conditions> Equipment: Shimadzu Corporation laser diffraction particle size distribution analyzer SALD-2300 Measurement principle: Laser diffraction Cell: Batch cell Average particle size calculation method: Median diameter (D50)

[0055] (6) Stability over time (viscosity) For each of the aqueous suspension concentrate pesticide compositions of Examples 1 to 13 and Comparative Examples 1 to 5, the viscosity was measured at 20 rpm at 25°C using an E-type viscometer. Measurements were carried out immediately after preparation of the formulation (initial stage) and after 28 days at 40°C. <Measurement conditions> Equipment: TVE-25H (jig (cone rotor) 1°34' x R24) (Tokyo Glass Instrument Co., Ltd.)

[0056] [Table 5]

[0057] [Table 6]

[0058] As shown in the evaluation results in [Table 3], the aqueous suspension pesticide compositions of Examples 1 to 13 did not form hard cakes after 14 days of storage at 54°C, and it was confirmed that most of them could be redispersed by simply inverting and mixing about 20 times. Furthermore, the foam height during grinding was 3.0 cm or less, and the foaming during dilution and dispersion was 5 cm or less, confirming that these compositions are excellent in suppressing foaming during formulation production and dilution and shaking. Furthermore, the stability tester The formulation separation rate measured and calculated using ST-1 was 80% or less, and separation and sedimentation were suppressed even after aging. The median diameter (D50) was 50 μm or less both initially and after aging, confirming that the composition maintained its particle size. Although there were examples with a higher formulation separation rate (%) than the comparative examples described below, the hard cake formation evaluation confirmed that all were redispersible, ensuring sufficient redispersibility as an aqueous suspension pesticide composition. On the other hand, in Comparative Examples 1 to 5, hard cakes formed after storage (when liquid oils and fatty acid esters were used), and the formulations were unable to be produced due to excessive foaming during production, which caused the formulations to overflow from the grinding equipment, making subsequent evaluation impossible.

Claims

1. An aqueous suspension pesticide composition comprising: (a) an agrochemical technical grade; (b) oils and fats and fatty acids; (c) a surfactant; and (d) water, The (b) oils and fats and fatty acids are at least one selected from the group consisting of oils and fats, fatty acids, and fatty acid salts, each having a melting point of 30°C to 250°C, Aqueous suspension pesticide composition.

2. 2. The pesticidal aqueous suspension concentrate according to claim 1, wherein the pesticide (a) is a solid pesticide active ingredient having a solubility in water of 1000 ppm or less at 25°C and a melting point of 60°C or higher.

3. 2. The pesticidal composition according to claim 1, wherein the (b) oils and fatty acids are contained in an amount of 0.01 to 5% by mass relative to the total mass of the pesticidal composition.

4. 2. The pesticidal aqueous suspension concentrate according to claim 1, wherein the oils and fatty acids (b) are hydrogenated castor oil.

5. 2. The pesticidal aqueous suspension concentrate according to claim 1, which has a median diameter (D50) of 50 μm or less as determined by a laser diffraction scattering method.

6. 2. The pesticidal aqueous suspension concentrate according to claim 1, which is a flowable formulation for pesticides.

7. 2. The pesticidal composition according to claim 1, wherein the concentration of the dispersed phase is 1 to 50% by mass, and the pesticidal composition does not form a hard cake even after storage at 54°C for 14 days.

8. A method for producing an aqueous suspension concentrate pesticide composition, comprising: The method includes a step of wet-grinding a mixture containing an agricultural chemical technical grade, oils and fats, fatty acids, a surfactant, and water (excluding an embodiment in which the oils and fats and fatty acids are added after the wet-grinding step), The wet-grinding step is a step of simultaneously wet-grinding the agricultural chemical technical product, the oils and fats, the fatty acids, and the surfactant, The fats and oils and fatty acids are at least one selected from the group consisting of fats and oils, fatty acids, and fatty acid salts having a melting point of 30°C to 250°C. A method for producing an aqueous pesticide suspension.

9. The method for producing an aqueous suspension concentrate pesticidal composition according to claim 8, wherein the oils and fatty acids before wet-milling have an average particle size of 1 cm or less.

10. The method includes a step of wet-grinding a mixture containing an agricultural chemical technical grade, oils and fats, fatty acids, a surfactant, and water (excluding an embodiment in which the oils and fats and fatty acids are added after the wet-grinding step), A method for suppressing foaming during the production of an aqueous pesticide suspension.

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