Pesticidal emulsifiable concentrate

Abstract: The present invention provides a low-irritant pesticidal emulsifiable concentrate comprising (a) 1 to 60% by weight of at least one pesticidally active compound selected from pyriproxyfen and a pyrethroid compound, (b) 2 to 15% by weight of at least one surfactant and (c) 15 to 90% by weight of at least one aromatic ester solvent represented by the formula: Ar-X-COOR or the formula: RCOO-X-Ar [wherein R represents a non-aromatic group having 1 to 6 carbon atoms; Ar represents an aromatic group; and X represents a single bond or an alkylene group having 1 to 6 carbon atoms]. The pesticidal emulsifiable concentrate of the present invention can be used as an emulsion which is superior in emulsion stability when used after diluting with water, and has low irritation.

Description: The present invention relates to a low-irritant pesticidal emulsifiable concentrate which can be used as an emulsion which is superior in emulsion stability when used after diluting with water. Pesticidally active compounds are normally used in various forms which are easy to use, and one of the usual preparations for pyriproxyfen and a pyrethroid compound is an emulsifiable concentrate. The pesticidal emulsifiable concentrate is normally composed of a pesticidally active compound, a surfactant and an organic solvent, and is used after diluting with water. Various trials are made in selection of surfactants, selection of organic solvents and their combinations on making the pesticidal emulsifiable concentrate in order to enhance emulsion stability of the emulsion obtained by diluting with water and to reduce toxicity and phytotoxicity to crops depending on the kind of the pesticidally active compound. Document WO-A95/31898 discloses novel pesticidal oil-in-water emulsion compositions, containing an active substance, a solvent chosen from the class of phthalates and fatty esters derived from vegetable oils, optionally combined with a solvent chosen from ketones, amides and alkylpyrrolidones, and an aqueous phase containing a silicate derivative. WO 96/01047 describes emulsifiable concentrates containing one or more pesticidal active ingredients, a solvent selected from the class of esters, vegetable oils and esters thereof, and an emulsifying surfactant system forming an oil-in-water emulsion when the formulation is added to water. Finally, GB-A-.507 902 discloses an insecticidal concentrate comprising a fixed oil, a contact insecticide, a volatile liquid in which the contact insecticide is soluble and which is itself soluble in the oil and an emulsifying agent soluble in the other components of the concentrate. An object of the present invention is to provide a pesticidal emulsifiable concentrate which is superior in emulsion stability on dilution with water and has low irritation. The present invention provides a pesticidal emulsifiable concentrate comprising (a) 1 to 60% by weight of pyriproxyfen, (b) 2 to 15% by weight of at least one surfactant and (c) 15 to 90% by weight of at least one aromatic ester solvent represented by the formula: Ar-X-COOR or the formula: RCOO-X-Ar [wherein R represents a non-aromatic group having 1 to 6 carbon atoms; Ar represents an aromatic group; and X represents a single bond or an alkylene group having 1 to 6 carbon atoms] which is superior in emulsion stability on dilution with water and of low irritation. As a reference a pyrethroid compound is also mentioned as a pesticidally active compound. Examples of the pyrethroid compound include compounds represented by the formula: [wherein R 1 represents a group of the formula: or [wherein Y 1 and Y 2 are the same or different and each represents a methyl group, a trifluoromethyl group, a halogen atom or an alkoxycarbonyl group ( the number of carbon atoms of the alkoxy group is from 1 to 4); and Z represents a halogen atom or a difluoromethoxy group]; R 2 represents a hydrogen atom or a cyano group; and R 3 represents a hydrogen atom or a fluorine atom]. Examples of the compounds represented by the formula [3] include pyrethroid compounds such as Fenvalerate [α - cyano-3-phenoxybenzyl 2-(4-chlorophenyl)-3-methylbutyrate], es-Fenvalerate [(S)-α-cyano-3-phenoxybenzyl (S)-2-(4-chlorophenyl)-3-methylbutyrate], Fenpropathrin [α-cyano-3-phenoxybenzyl 2,2,3,3-tetramethylcyclopropanecarboxylate], Permethrin [3-phenoxybenzyl 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate], Cypermethrin [α-cyano-3-phenoxybenzyl 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate], d-phenothrin [3-phenoxybenzyl (1R)-chrysanthemate], Cyphenothrin [α-cyano-3-phenoxybenzyl (1R)-chrysanthemate], Cyhalothrin [α -cyano-3-phenoxybenzyl (Z)-(2-chloro-3,3,3-trifluoropropenyl)-2,2-dimethylcyclopropanecarboxylate], Cyfluthrin [α-cyano-4-fluoro-3-phenoxybenzyl 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate] and Flucythrinate [α-cyano-3-phenoxybenzyl (S)-2-(4-difluoromethoxyphenyl)-3-methylbutyrate]. Further pyrethroid compounds such as Tralomethrin [(S)-α-cyano-3-phenoxybenzyl 2,2-dimethyl-3-(1,2,2,2-tetrabromoethyl)cyclopropanecarboxylate], Allethrin [3-allyl-2-methyl-4-oxo-2-cyclopentenyl - chrysanthemate], Cycloprothrin [α-cyano-3-phenoxybenzyl 2,2-dichloro-1-(4-ethoxyphenyl)cyclopropanecarboxylate], Fluvalinate [α-cyano-3-phenoxybenzyl N-(2-chloro-α, α, α -trifluoro-p-tolyl)valinate] and Etofenprox [2-(4-ethoxyphenyl)-2-methylpropyl 3-phenoxybenzyl ether], can be mentioned as a pesticidal active ingredient compound in the pesticidal emulsifiable concentrate. The pesticidally active compound is contained in the pesticidal emulsifiable concentrate of the present invention in an amount of 1 to 60% by weight, preferably 2 to 40 % by weight. Examples of the surfactant used in the present invention include nonionic surfactants such as polyoxyethylene polyoxypropylene block polymers, fatty acid ester of polyoxyethylene polyoxypropylene block polymers, polyoxyethylene polyoxypropylene polyaryl ethers, polyoxyethylene polyoxypropylene alkyl aryl ethers, polyoxyethylene alkyl aryl ethers, polyoxyethylene vegetable oils (e.g. polyoxyethylene castor oil), polyoxyethylene polyaryl ethers, polyoxyethylene polyaryl ether polymers, polyoxyethylene hardened vegetable oils (e.g. polyoxyethylene hardened castor oil), polyoxyethylene fatty acid esters, polyoxyethylene alkyl ethers, polyoxyethylene tristyryl phenylphosphate diesters, polyoxyethylene polyoxypropylenetristyryl phenylphosphate diesters, fatty acid alcohol polyglycol ethers and glycerin fatty acid ester, and anionic surfactants such as alkaline earth metal salts (e.g. calcium salts) and amine salts of alkyl aryl phosphates, alkaline earth metal salts (e.g. calcium salts) and amine salts of alkylaryl sulfonates, alkaline earth metal salts of polyoxyethylene alkyl aryl sulfonates, alkaline earth metal salts (e.g. calcium salts) of polyoxyethylene alkyl aryl phosphates, alkaline earth metal salts (e.g. calcium salts) of polyoxyethylene polyaryl phosphates and alkaline earth metal salts (e.g. calcium salts) and amine salts of dialkylsulfosuccinates. Among them, polyoxyethylene polyaryl ethers(e.g. polyoxyethylene tristyryl phenol ether), polyoxyethylene polyoxypropylene polyaryl ethers (e.g. polyoxyethylene polyoxypropylene tristyrylphenol ether), polyoxyethylene castor oil, polyoxyethylene hardened castor oil, and salts of alkyl aryl sulfonates (e.g. calcium) dodecylbenzene sulfonate) are preferred. The surfactant is contained in the pesticidal emulsifiable concentrate of the present invention in an amount of 2 to 15% by weight, preferably 2 to 10 % by weight. In the aromatic ester solvent used in the present invention, Ar of formula [1] and formula [2] is preferably a phenyl group which may be substituted e.g. with at least one methyl group; X is preferably a single bond, a methylene group or an ethylene group; R is preferably an alkyl group having 1 to 6 carbon atoms. Preferred examples of the aromatic ester solvent include benzyl esters such as benzyl acetate, phenyl esters such as phenyl acetate, tolyl esters such as p-tolyl acetate, 4-phenylbutyl esters such as 4-phenylbutyl acetate, benzoate esters such as methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate and isoamyl benzoate, methyl benzoates such as ethyl 2-methyl benzoate, methyl 2-methylbenzoate, ethyl 3-methylbenzoate and ethyl 4-methylbenzoate, phenyl propionates such as ethyl phenyl propionate, and phenyl acetates such as ethyl phenylacetate. The aromatic ester solvent is contained in the pesticidal emulsifiable concentrate of the present invention in an amount of 15 to 90% by weight, preferably 20 to 60 % by weight. The pesticidal emulsifiable concentrate of the present invention may further contain other solvents and usual additives in addition to the pesticidally active compound (a), the surfactant (b), and the aromatic ester solvent (c), if necessary. Examples of the solvent include aromatic hydrocarbon solvents such as alkylbenzenes (e.g. xylene and tetramethylbenzene), alkylnaphthalenes (e.g. methylnaphthalene), diphenylethane, dixylylethane and phenylxylylethane, non-aromatic ester solvents such as methyl laurate, isopropyl myristate, isopropyl palmitate, methyl caprinate, methyl oleate, isobutyl oleate, butyl propionate, isoamyl propionate, ethyl butyrate, butyl butyrate, isoamyl butyrate, isoamyl isovalerate, amyl lactate, methyl linoleate, methyl linolenate and coconut fatty acid methyl ester, vegetable oils such as soybean oil, corn oil, rape seed oil, linseed oil, castor oil, cottonseed oil, peanut oil and sesame oil, aliphatic hydrocarbon solvents; alcohol solvents such as 2-ethyl hexanol, and ketone solvents such as cyclohexanone and acetophenone. Examples of the additives include antioxidants such as 3-/2-t-butyl-4-hydroxyanisole and butylated hydroxytoluene, and pigments. The pesticidal emulsifiable concentrates of the present invention are normally used as an agent for foliar treatment, or seed treatment. When using in the foliar treatment, an emulsion prepared by diluting the pesticidal emulsifiable concentrate of the present invention with water (generally from about 100 to 5000 times) is normally applied to foliage, although the concentration varies depending on the kind and content of the active ingredient. Also, an emulsion prepared by diluting the pesticidal emulsifiable concentrate of the present invention with water (generally from about 10 to 5000 times) may be aerial-applied by a helicopter. When using in the seed treatment, seeds are dipped in a dilution of the pesticidal emulsifiable concentrate of the present invention prepared by diluting with water (from about 10 to 100 times), or a dilution of the pesticidal emulsifiable concentrate of the present invention prepared by diluting with water (from about 2 to 100 times) is sprayed onto the seed. The following Examples further illustrate the present invention in detail. First, Formulation Examples of the pesticidal emulsifiable concentrate of the present invention will be shown. In the following Examples, "parts" are "parts by weight". Formulation Example 1 11 Parts of pyriproxyfen, 1.25 parts of Soprophor 796/P (surfactant manufactured by Rhone-Poulenc, polyoxyethylene polyoxypropylene polyaryl ether having HLB of 13.5), 3.75 parts of Geronol FF-4-E (surfactant manufactured by Rhone-Poulenc, containing 50 % by weight of calcium dodecylbenzenesulfonate), 22 parts of benzyl acetate, and the residual parts of Solvesso 150 (manufactured by Exxon Co., aromatic hydrocarbon solvent having 9 to 11 carbon atoms) were combined to make 100 parts, followed by sufficient mixing to obtain a pesticidal emulsifiable concentrate of the present invention. Formulation Example 2 According to the same manner as that described in Formulation Example 1 except for using 44 parts of benzyl acetate in place of 22 parts of benzyl acetate, a pesticidal emulsifiable concentrate of the present invention was obtained. Formulation Example 3 11 Parts of pyriproxyfen, 10 parts of Sorpol 3816 (surfactant manufactured by Toho Chemical Industry Co., containing polyoxyethylene polyaryl ether, polyoxyethylene polyaryl ether polymer and calcium salt of alkylaryl sulfonate), 22 parts of benzyl acetate and the residual part of Solvesso 150 were combined to make 100 parts, followed by sufficient mixing to obtain a pesticidal emulsifiable concentrate of the present invention. Formulation Example 4 11 Parts of pyriproxyfen, 7 parts of Sorpol 3816, 44 parts of benzyl acetate and the residual part of Solvesso 150 were combined to make 100 parts, followed by sufficient mixing to obtain a pesticidal emulsifiable concentrate of the present invention. Formulation Example 5 11 Parts of pyriproxyfen, 10 parts of T-MULZ PB High (surfactant manufactured by Harcros Co., nonionic surfactant), 50 parts of benzyl acetate and the residual part of Solvesso 150 were combined to make 100 parts, followed by sufficient mixing to obtain a pesticidal emulsifiable concentrate of the present invention. Formulation Example 6 11 Parts of pyriproxyfen, 7 parts of Geronol FF-6-E (surfactant manufactured by Rhone-Poulenc Co., blend emulsifier containing polyoxyethylene polyaryl ether and calcium salt of alkylaryl sulfonate), 3 parts of Geronol FF-4-E, 50 parts of benzyl acetate and the residual part of Solvesso 150 were combined to make 100 parts, followed by sufficient mixing to obtain a pesticidal emulsifiable concentrate of the present invention. Formulation Example 7 11 Parts of pyriproxyfen, 7 parts of Geronol FF-6-E, 3 parts of Geronol FF-4-E and 79 parts of benzyl acetate were sufficiently mixed to obtain a pesticidal emulsifiable concentrate of the present invention. Formulation Example 8 (Reference Example) 5 Parts of Fenvalerate, 1.25 parts of Soprophor 796/P, 3.75 parts of Geronol FF-4-E, 25 parts of benzyl acetate and the residual part of Solvesso 150 were combined to make 100 parts, followed by sufficient mixing to obtain a pesticidal emulsifiable concentrate of the present invention. Formulation Example 9 (Reference Example) According to the same manner as that described in Formulation Example 8 except for using 11 parts of Fenvalerate in place of 5 parts of Fenvalerate, a pesticidal emulsifiable concentrate of the present invention was obtained. Formulation Example 10 (Reference Example) According to the same manner as that described in Formulation Example 8 except for using 5 parts of Permethrin in place of 5 parts of Fenvalerate, a pesticidal emulsifiable concentrate of the present invention was obtained. Formulation Example 11 (Reference Example) According to the same manner as that described in Formulation Example 5 except for using 11 parts of Cypermethrin in place of 11 parts of pyriproxyfen, a pesticidal emulsifiable concentrate of the present invention was obtained. Formulation Example 12 According to the same manner as that described in Formulation Example 1 except for using 22 parts of p-tolyl acetate in place of 22 parts of benzyl acetate, a pesticidal emulsifiable concentrate of the present invention was obtained. Formulation Example 13 According to the same manner as that described in Formulation Example 1 except for using 22 parts of propyl benzoate in place of 22 parts of benzyl acetate, a pesticidal emulsifiable concentrate of the present invention was obtained. Next, the stability on dilution of the pesticidal emulsifiable concentrate of the present invention with water will be illustrated by the Test Examples. Test Example 1 Each of the pesticidal emulsifiable concentrates (0.1 ml) of the present invention obtained in the Formulation Examples 1 to 7 was poured into a 100 ml tapped measuring cylinder filled with hard water (500 ppm). Then, each measuring cylinder was turned upside down in a rate of 30 times per minute, and the content liquid was mixed uniformly and allowed to stand. One hour after the beginning of standing, the presence or absence of the separation of the liquid was observed. As a result, no separation of the liquid was recognized in any pesticidal emulsifiable concentrate of the present invention. Two hours after the beginning of standing, no separation of the liquid was recognized. Furthermore, the test for irritation to eyes of the pesticidal emulsifiable concentrate of the present invention will be shown. Test Example 2 Eyes of rabbits were treated with the pesticidal emulsifiable concentrate (0.1 ml) of the present invention obtained in Formulation Example 5, and the eyelids were lightly closed for 1 second and, after 30 seconds, 300 ml of warm water was sprayed to rinse eyes for 1 minute. After 1 week, the degree and area of corneal opacity were examined. As a result, no corneal opacity was recognized. The pesticidal emulsifiable concentrate of the present invention is an emulsifiable concentrate which is superior in emulsion stability on use after diluting with water, and has a property of low irritation.

Claims: A pesticidal emulsifiable concentrate comprising (a) 1 to 60% by weight of pyriproxyfen, (b) 2 to 15% by weight of at least one surfactant and (c) 15 to 90% by weight of at least one aromatic ester solvent represented by the formula: Ar-X-COOR or the formula: RCOO-X-Ar [wherein R represents a non-aromatic group having 1 to 6 carbon atoms; Ar represents an aromatic group; and X represents a single bond or an alkylene group having 1 to 6 carbon atoms]. The pesticidal emulsifiable concentrate according to the claim 1, wherein the aromatic ester solvent (c) is at least one selected from benzyl acetate, phenyl acetate, p-tolyl acetate, 4-phenylbutyl acetate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate isoamyl benzoate, ethyl 2-methylbenzoate, methyl 2-methylbenzoate, ethyl 3-methylbenzoate, ethyl 4-methylbenzoate, ethyl phenylpropionate and ethyl phenylacetate. The pesticidal emulsifiable concentrate according to claim 1 or 2, wherein the surfactant (b) is a nonionic surfactant and/or anionic surfactant. The pesticidal emulsifiable concentrate according to any one of claims 1 to 3, wherein the amounts of the pesticidal active ingredient compound (a), the surfactant (b) and the aromatic ester solvent (c) are 2 to 40% by weight, 2 to 10% by weight and 20 to 60% by weight, respectively The pesticidal emulsifiable concentrate according to any one of claims 1, 3 or 4, wherein the aromatic ester solvent (c) is one represented by the formula [1]: Ar-X-COOR [wherein R represents a non-aromatic group having 1 to 6 carbon atoms; Ar represents an aromatic group; and X represents a single bond or an alkylene group having 1 to 6 carbon atoms]. The pesticidal emulsifiable concentrate according to any one of claims 1, 3 or 4, wherein the aromatic ester solvent (c) is one represented by the formula [2]: RCOO-X-Ar [wherein R represents a non-aromatic group having 1 to 6 carbon atoms; Ar represents an aromatic group; and X represents a single bond or an alkylene group having 1 to 6 carbon atoms].

Inventors: ZEN SHIGEKAZU, ZEN, SHIGEKAZU
Applicants: SUMITOMO CHEMICAL CO, SUMITOMO CHEMICAL COMPANY, LIMITED
Application year: 1997
Main classification: A01N25
IPC codes: A01N25, A01N53, A01N43