JPH0539202A - Oil-in-water pesticide composition and its production - Google Patents

Abstract

PURPOSE:To provide the subject composition easy to prepare in the form of an emulsion from an original form of pesticide, also causing no crystallization of the pesticide in the emulsion with longterm stable dispersion of emulsified droplets, thus excellent in preservability for a long period. CONSTITUTION:Part of an aqueous phase is added to a mixture of (A) poorly soluble or insoluble original form of a pesticide <=100 deg.C in melting point and <=0.5wt.% in the solubility at 20-25 deg.C in water and (B) a surfactant, and, in case said original form is solid at normal temperatures, furthermore (C) an oily phase containing an organic solvent pref. <=10wt.% in the solubility in water at 20 deg.C to form a gelled product. The rest of the aqueous phase is then added to this product to effect phase inversion from water-in-oil type to oil-in- water type, thus easily obtaining the objective composition having the original pesticide effect without no problems such as dusting in use and flash ignition danger in the production, transportation and storage etc. The preferable amounts of the components are as follows:A=1-60wt.% (esp. 1-50wt.%); B:1-30wt.% (esp. 5-20wt.%);andC=0-50wt.% (esp. 5-40wt.%).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel oil-in-water pesticide composition and a method for producing the same, and more specifically, the pesticide raw material in the emulsion does not crystallize, and the emulsion droplets are stably dispersed for a long period of time. Oil-in-water pesticide composition and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, various types of dispersion-type formulations in which solid or liquid pesticide particles are dispersed in an aqueous phase have been known as agricultural formulations. The characteristics of these dispersion-type preparations have solved the drawbacks of other preparations, such as the problem of dusting when using a wettable powder, the problem of ignition risk during production of emulsions, transportation, storage, etc. It is thought that there is a point. These dispersed formulations are
Broadly speaking, a suspension type formulation in which a solid pesticide raw material is crushed into fine particles and suspended in water and a liquid pesticide raw material or a liquid pesticide raw material added with an organic solvent are used with an appropriate dispersant. It is divided into emulsion type preparations that form a fine emulsion in water.
For the former, known techniques such as those shown in Japanese Patent Publication No. 53-46889 and for the latter are JP-A-55.
Known techniques such as those disclosed in JP-A-124707 and JP-A-62-167702 are known.

The form of such agricultural preparation is affected by the physical properties of the pesticide bulk. Suspension type preparations have solid particles of agrochemicals suspended in water in a fine state, but when these particles are stored in water for a long period of time, the growth of particles occurs due to fluctuations in storage temperature. Therefore, it was often impossible to maintain a stable suspension state. Especially the melting point is 10
In the case of a solid raw material at 0 ° C. or lower, stable dispersion of particles was difficult due to crystal growth of solid particles. Further, in the case of a pesticidal drug substance that is liquid at room temperature, it was impossible to formulate it as a suspension-type drug product. On the other hand, when using a liquid pesticidal drug substance with a melting point near room temperature, an emulsion-type drug product cannot be used as a liquid drug substance even if it is a stable emulsion immediately after formulation even if it is stored at low temperature for a long time. In some cases, crystallization of the body occurred, making it impossible to maintain a stable emulsion state. In the case of a solid drug substance that has a melting point near room temperature and is liquefied by adding an organic solvent,
Originally liquid pesticide raw materials added with organic solvent will reduce crystallization of pesticide raw materials at low temperature, but liquefy by adding organic solvent to solid raw materials with melting point above room temperature. With respect to the obtained product, crystallization at a low temperature may still occur. Even if the liquid pesticide raw material does not crystallize at a low temperature, the oil phase and the water phase gradually separate due to the high storage temperature and repeated low and high temperatures. The muddy state sometimes collapsed.

[0004]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made it possible to achieve crystal growth of solid particles in suspension-type preparations or crystallization of liquid particles in emulsion-type preparations, which cannot be achieved by the prior art. Completely prevent the destabilization of the dispersed state in the emulsion formulation and completely prevent the destabilization of the dispersed state caused by the separation of the oil phase and the aqueous phase due to the coalescence of the liquid particles in the emulsion type formulation liquid. It has been examined for the purpose of prevention. As a result, the use of an appropriate organic solvent suppresses the crystallization of the pesticide raw material at low temperature. The use of an appropriate surfactant promotes the effect of preventing the precipitation of crystals. Prevention of the separation of the oil phase and the aqueous phase in the emulsion. The present invention has been completed by focusing on the consideration of the addition method of each component and the stirring efficiency during the production of an emulsion. That is, the gist of the present invention is characterized by comprising a pesticidal drug substance having a melting point of 100 ° C. or less and a solubility in water (20 to 25 ° C.) of 0.5% by weight or less, a surfactant, and an aqueous phase. The present invention resides in a phase-inversion emulsified oil-in-water agricultural chemical composition and a method for producing the same.

The present invention will be described in detail below. The pesticide raw material used in the present invention may be either liquid or solid at room temperature, but for example, it is generally difficult to stably disperse particles in a suspension-type preparation,
Solubility in water (20-25
It is characterized in that it is a poorly soluble or insoluble pesticide raw material having a content of 0.5% by weight or less. Specific examples of such pesticide raw materials include the following substances (unless specifically mentioned in terms of solubility, values at 25 ° C. are shown).

O-2,4-dichlorophenyl = o-ethyl = s-propyl phosphorodithioate (bp 13)
3 to 138 ° C./0.1 mmHg) 10 ppm Dimethyl-2, -2-dichlorovinyl phosphate (bp 35 ° C./0.05 mmHg) 1 ppm (RS) -α-cyano-3-phenoxybenzyl = (R
S) -2 (4-chlorophenyl) -3-methylbutanoate (bp 5.33 to 5.81 ° C / 250 mmHg)
0.31 ppm (RS) -α-cyano-3-phenoxybenzyl = N-
(2-chloro-α, α, α-trifluoro-p-tolyl) -D-valinate (viscous liquid) 0.002 ppm (RS) -α-cyano-3-phenoxybenzyl =
(S) -2- (4-difluoromethoxyphenyl) -3
-Methyl butyrate (viscous liquid) 0.5 ppm Ethyl paranitrophenyl thionobenzenephosphonate (mp 36 ° C) insoluble 2-Secondary butylphenyl-N-methylcarbamate (mp 32 ° C) 660 ppm 2- (4-Ethoxyphenyl) -2-methylpropyl =
3-phenoxybenzyl ether (mp 36.4)
~ 38 ° C) 0.001 ppm or less Ethyl 4,4'-dichlorobenzylate (mp. 35-35)
37 ° C.) 10 ppm o, o-diisopropyl-s-benzylthiophosphate (mp 22.5 to 33.8 ° C.) 400 ppm 2-methoxy-4H-1,3,2-benzodioxaphosphorin-2- Sulfide (mp 55-60 ° C) 50
ppm (RS) -α-cyano-3-phenoxybenzyl = 2
2,3,3-Tetramethylcyclopropanecarboxylate (mp 51.4 ° C.) 14,1 ppms-4-phenoxybutyl dimethylthiocarbamate (mp.
40-41 ° C.) 30 ppm (E) -4-chloro-α, α, α-trifluoro-N-
(1-imidazol-1-yl-2-propoxyethylidene) -o-toluidine (mp 63.5 ° C.) 12,
5 ppm N- (4-tert-butylbenzyl) -1-methyl-3-ethyl-4-chloro-5-pyrazolecarboxamide (mp 62 ° C.) 2,8 ppm 2-chloro-1- (2,4- Dichlorophenyl) vinyl dimethyl phosphate (mp 69-70 ° C) 130
ppm methatril-N-methyl carbamate (mp. 76-
77 ° C.) 0.26 ppm 3,4-xylyl-N-methylcarbamate (mp.
79-80 ° C.) 1300 ppm Ethyl-o-benzoyl-3-chloro-2,6-dimethoxybenzohydroxymate (mp 73 ° C.) 30 p
pm 2-Isopropylphenyl-N-methylcarbamate (mp 89-91 ° C) 265 ppm (±) -2- (1-ethoxyiminobutyl) -5- [2
-(Ethylthio) propyl] -3-hydroxycyclohex-2-enone (colorless oily liquid) 25-4700 pp
m (pH 4 to 7) / 20 ° C φ-ethyl-φ- (3-methyl-6-nitrophenyl)
sec-Butylphosphoroamidothioate (yellowish brown oily liquid) 5.1 ppm (20 ° C.) α, α, α-trifluoro-2,6-dinitro-n, n
-Dipropyl-paratoluidine (mp 49 ° C) 1p
less than pm 2-methylthio-4,6-bis (ethylamino) -S-
Triazine (mp 82 to 83 ° C.) 450 ppm 3-3,4-dichlorophenyl) -1-methoxy-methylurea (mp 93 to 94 ° C.) 75 ppm 2- (α-naphthoxy) -N, N-diethylpropionamide (mp 69.5 ° C.) 73 ppm 3 ′, 4′-dichloropropionanilide (92-93)
225 ppm 2-chloro-2 ', 6'-diethyl-N- (methoxymethyl) acetanilide (mp 40-41 ° C) 240
ppm S- (4-chlorobenzyl) -N, N-diethylthiocarbamate (mp 3.3 ° C.) 30 ppm Butyl = (RS) -2- [4-5-trifluoromethyl-2-pyridyloxy) Phenoxy] propionate (bp 202 ° C.) 1 ppm (20 °) diisopropyl = 1.3-dithiolane-2-ylidene-
Malonate (mp 54.5-55.0 ° C) 50pp
m 3′-isopropoxy-2-methylbenzanilide (mp 92-93 ° C.) 12.7 ppm φ-ethyl-S, S-diphenyldithiophosphate (bp 154 ° C./0.01 mmHg) 5 ppm 3 -Methyl-1,5-bis (2,4-xylyl) -1,
3,5-triazapenta-1,4-diene (mp. 8)
7-88 ° C.) less than 1 ppm 4,4′-dibromobenzylsan isopropyl (m.p.
p. 77 ° C) Less than 5 ppm Parachlorophenyl Parachlorobenzene sulfonate (mp 87 ° C) Poorly soluble in water 1,1-bis (chlorophenyl) -2,2,2-trichloroethanol (mp 79 ° C) 0.8 ppm (25
Degree) ethyl = N- [2,3-dihydro-2,2-dimethylbenzofuran-7-yloxycarbonyl (methyl) aminothio] N-isopropyl-β-alaninate (pale yellow viscous liquid) 8 ppm S-methyl-N -[(Methylcarbamoyl) oxy] thioacetimidate (mp 78-79 ° C) 6 ppm Ethyl dimethyldithiophosphoryl phenylacetate (m.p.
p. 20 ppm (2-isopropyl-4-methylpyridyl-6) -diethylthiophosphate (bp 83-84 ° C / 0.
0002 mmHg) 40 ppm Alkyl polyoxyethylene alcohol (mp 50)
Dodecyl Acetate (colorless transparent oily liquid) sparingly soluble in water (-55 ° C) These may be used alone or in combination of two or more kinds.

[0007] When the above-mentioned pesticide raw material is a solid at room temperature,
An organic solvent is used in combination to form an emulsion.
As an organic solvent, the solubility in water at 20 ° C. is 10
Those having a weight% or less are preferably used. In particular,
Cumene, xylene, Kawakazole (Kawasaki Kasei Co., Ltd., main component methylnaphthalene), Solvesso 150
(Exxon Chemical Co., Ltd., aromatic content 99.3%), Solvesso 200 (Exxon Chemical Co., Ltd., aromatic content 9
Aromatic hydrocarbons such as 9.8%); aliphatic hydrocarbons such as n-hexane, liquid paraffin and kerosene; esters such as ethyl acetate and n-amyl acetate; vegetable oils such as soybean oil and corn oil And alcohols such as n-butanol and n-octanol, etc., and they are used alone or as a mixed solvent of two or more kinds.

As the surfactant, both nonionic and anionic surfactants can be used. Specifically, polyoxyethylene alkyl allyl ethers, polyoxyethylene castor oil ethers, polyoxyalkylene glycols, etc. Nonionic surfactants; lignin sulfonates, naphthalene sulfonates, polyoxyethylene alkyl phenyl ether phosphate and the like anionic surfactants, and the like, nonionic surfactants, even if each anionic surfactant is used alone, It can be used as a mixture.

The water phase is not particularly limited as long as it contains water, but may contain additives such as an antifoaming agent and an antifreezing agent, if necessary. Examples of such antifoaming agents include Solpol EX-300 (Toho Chemical Industry Co., Ltd., main component silicone emulsion), Solpol B184 (Company, main component polyalkylene glycol), and antifreeze agents such as ethylene glycol and propylene glycol. Alcohols such as polypropylene glycol and glycerin are preferably used.

Next, a method for producing the agricultural chemical composition of the present invention will be described. When producing an emulsion using each of the above components, the method of adding each component is to first mix the pesticide raw material, the surfactant and, if necessary, the total amount of the organic solvent into a uniform solution, and add water to this. A portion of the phase is added to form a gel.
When a gel-like substance is formed, the viscosity of the solution (mixture) rapidly increases. The addition of the aqueous phase at this time is not particularly limited as long as the oil phase forms a gel, but in order to produce a high quality pesticide composition efficiently in a short time, the necessary amount is added at once. Rather, it is preferable to continuously add the aqueous phase little by little while confirming the phase change. Subsequently, the remaining aqueous phase is added to the gel-like material. With the addition of this aqueous phase,
The viscosity of the solution (mixture) decreases again. The addition of the aqueous phase at this time is not particularly limited, as long as the gel material is phase-inverted from the water-in-oil type to the oil-in-water type.

By the above operation, the emulsified system is phase-inverted from the initial water-in-oil emulsion to the latter oil-in-water emulsion. The addition amount of each component at this time is not particularly limited as long as it is an amount that forms a gel, but the pesticide raw material is preferably 1 to 60% by weight, more preferably 1 to 50% by weight, and the surfactant is It is preferably 1 to 30% by weight, more preferably 5 to 20% by weight, and preferably 0 to 50% by weight, and more preferably 5 to 40% by weight when an organic solvent is added. When an antifoaming agent is added to the aqueous phase, it is preferably 0.1 to 1.0% by weight, more preferably 0.1 to 1.0% by weight.
0.5% by weight, preferably 5 to 15% by weight when an antifreezing agent is added, and more preferably 5 to 10% by weight.

Uniform mixing of such systems is described, for example, in T.W. K Aji Homo Mixer (Special Kika Kogyo Co., Ltd.), KENMIX
Uniform mixing can be easily performed by using an emulsion mixer such as CHEF resist (Kodaira Manufacturing Co., Ltd.) or a stirring mixer type mixer having a barrel having an appropriate size and shape with respect to the inner diameter of the mixing container. In addition, in order to smoothly carry out the phase inversion, it is more preferable to carry out the operation of only stirring and mixing without adding the aqueous phase for several minutes to 30 minutes after the gel-like substance is formed.
The temperature at the time of stirring is preferably 15 to 35 ° C., and it is particularly preferable to perform the stirring near room temperature.

[0013]

EXAMPLES The present invention will be described in detail below with reference to examples, but the invention is not limited to the examples as long as the gist thereof is not exceeded. Example 1 N- (4-t-butylbenzyl) -1-methyl-3-ethyl-4-chloro-5-pyrazolecarboxamide (mp 62 ° C, water solubility 2.8 ppm / 25 ° C) was added to 10. 3 parts by weight, Kawakazol (organic solvent manufactured by Kawasaki Kasei Co., Ltd., main component methylnaphthalene) 20 parts by weight and Solpol CA-42 (surfactant manufactured by Toho Chemical Industry, polyoxyethylene castor oil ether) 1
An oil portion was obtained by sufficiently mixing and dissolving 0 weight part of each. At this time, the viscosity of the oil part was 20 cps (20 ° C.). On the other hand, 59.45 parts by weight of water and Pronal EX-30
0 (Toho Chemical Industry Co., Ltd. antifoaming agent, silicon emulsion) 0.25 parts by weight was mixed to obtain a water part.

First, T. K. Aji Homo Mixer HV-SL
Type (made by Tokushu Kika Kogyo Co., Ltd.) 30l container and oil part 806
0 g was added, and 1400 g of water was added thereto continuously using a roller pump over 21 minutes. At this time, the viscosity of the solution increased to 200,000 cps (20 ° C.) or higher, and formation of a gel-like substance was confirmed. Next, after the addition of the water portion was stopped and only stirring was performed for 10 minutes, the remaining water portion 1054
0 g was added continuously with a roller pump in 31 minutes.
Finally, the mixture was stirred for 10 minutes to prepare an emulsion. The viscosity of the emulsion thus obtained was 10 cps (20 ° C.).

The operating conditions of the stirrer were that the peripheral speed of the homomixer was 22.3 m / sec (rotation speed 8900 rpm).
The pass rotation at this time was 930. The rotation speed of the paddle mixer was 44 rpm. The temperature remained constant at 29 ° C throughout. Example 2 In addition of the water part of Example 1, the remaining water part 10540
An emulsion was obtained in the same manner except that g was added all at once.

Comparative Example 1 An emulsion was obtained in the same manner as in Example 1 except that the total amount of 11940 g was continuously added for 60 minutes by using a roller pump. At this time, the viscosity of the solution hardly changed from beginning to end, and formation of a gel-like substance was not confirmed. Comparative Example 2 An emulsion was obtained in the same manner as in the addition of the water part in Example 1, except that the total amount of 11940 g was added at once. No formation of gel was confirmed.

Test Example 1 Room temperature (RT): 40 ° C., 6 for the emulsions prepared in Examples 1 and 2 and Comparative Examples 1 and 2, respectively.
Shake in a 0 ° C incubator (60 ° C, V) and 1 at 40 ° C
A storage test was carried out for 10 days to 360 days under the condition of 2 hours / -10 ° C. and repeated (FT) for 12 hours, and the change in the separation rate of the composition with time and the presence or absence of crystal precipitation were determined as follows. I looked it up. The results are shown in Table 1.

Separation rate (%) of sample: diameter 3 cm, height 6
The sample was poured into a transparent glass bottle with a screw cap of cm to a height of 5 cm, and the separation rate was calculated by the following formula.

[0019]

[Equation 1]

Presence or absence of crystal precipitation: Visual observation with the naked eye

[0021]

[Table 1]

Example 3 (RS) -α-cyano-3-phenoxybenzyl = N-
(2-chloro-α, α, α-trifluoro-p-tolyl) -D-valinate (viscous liquid, 2 × 10 ⁻⁶ g / l)
20.6 parts by weight and Solpol CA-4
10 parts by weight of 2 (surfactant manufactured by Toho Chemical Industry Co., Ltd., polyoxyethylene castor oil ether) were mixed and dissolved to obtain an oil portion. At this time, the viscosity of the oil part is 660 cps
(40 ° C). On the other hand, 61.15 parts by weight of water, 8 parts by weight of ethylene glycol (antifreezing agent) and 0.25 parts by weight of Pronal EX-300 (a defoaming agent made by Toho Chemical Industry Co., Ltd., a silicon emulsion) are mixed to prepare water. I got a part.

First, 1224 g of the oil portion was put into a 20 L container of universal mixer 20 L (manufactured by Kodaira Seisakusho), and 260 g of water portion was continuously added thereto for 20 minutes using a roller pump. At this time, the viscosity of the solution is 200,000 cps
The temperature increased to (40 ° C.) or higher, and formation of a gel-like substance was confirmed. Next, the addition of the water part was stopped, and after stirring was performed for 20 minutes, the remaining water part (2516 g) was continuously added in 20 minutes using a roller pump. Finally, stirring was performed for 10 minutes to obtain an emulsion. The viscosity of the emulsion thus obtained was 5.4 cps (40 ° C). The temperature is 25
Maintained ~ 30 ° C. Example 4 In the addition of the water part of Example 3, the remaining water part was 2516 g.
Was added at once, and an emulsion was obtained in the same manner.

Comparative Example 3 In the addition of the water part of Example 3, the total amount of the water part was 2776 g.
Was added at once, and an emulsion was obtained in the same manner. No formation of gel was confirmed. Comparative Example 4 In the addition of the water part of Example 3, the total amount of the water part was 2776 g.
An emulsion was obtained in the same manner except that was added continuously using a roller pump for 60 minutes. The viscosity of the solution hardly changed from beginning to end, and formation of a gel was not confirmed.

Test Example 2 The emulsions prepared in Examples 3 and 4 and Comparative Examples 3 and 4 were subjected to a storage test under the same conditions as in Test Example 1 for 0 to 200 days to separate each composition. The change in the rate with time and the change in the particle size were measured as follows. The results are shown in Table 2.

Separation rate (%) of sample: same as the measuring method of Test Example 1 Particle size (μm): Measured by using OTUKA laser beam particle size measuring device.

[0027]

[Table 2]

Example 5 φ-2,4-dichlorophenyl = φ-ethyl = S-propyl phosphorodithioate (brown liquid, bp 133)
˜138 ° C./0.1 mmHg, 10 ppm / 25 ° C.) 10.30 parts by weight and Solpol CA-42 (Toho Chemical Industry Co., Ltd. surfactant, polyoxyethylene castor oil ether) 10.00 parts by weight, respectively. The mixture was thoroughly mixed and dissolved to obtain an oil part. On the other hand, 79.45 parts by weight of water and 0.25 parts by weight of Pronal EX-300 (an antifoaming agent manufactured by Toho Chemical Industry Co., Ltd., a silicon emulsion) were mixed to obtain a water part. Oil portion 20.3g in 200ml beaker
Was charged and mixed with a four-bladed stirrer having a blade diameter of 0.8 D with respect to the inner diameter D of the container. When 5.6 g of water was gradually added to this and stirred for 20 minutes, the viscosity of the solution was remarkably increased and formation of a gel was confirmed. Next, the addition of the water part was stopped, and after only stirring for 20 minutes, the remaining water part of 74.1 g was continuously added over 20 minutes. Finally, the emulsion was prepared by stirring for 10 minutes. The stirring conditions were 500 rpm and 18 ° C. throughout. The viscosity and particle size of the obtained emulsion are shown in Table 4. The particle size was measured by the same method as in Test Example 2. Examples 6 to 11 In the same manner as in Example 5, emulsions having the compositions shown in Table 3 were obtained. Table 4 shows the viscosity, particle size, preparation temperature, and amount of water portion added until the formation of a gel-like substance in the obtained emulsion. The particle size was measured by the same method as in Test Example 2. Test Example 3 For the emulsions prepared in Examples 5-11, 10-30
A storage test was carried out for one day to examine changes in the separation rate of the composition over time and the presence or absence of crystal precipitation. The results are shown in Table 5. The storage conditions and the test method were the same as in Test Example 1.

[0029]

[Table 3] Weight parts ──────────────────────────────────── Example 5 Oil portion; φ− 2,4-Dichlorophenyl = φ-ethyl = S-propyl phosphorodithioate (brown liquid, 10.30 bp 133-138 / 0.1 mmHg, water solubility 10 ppm) Polyoxyethylene castor oil ether 10.00 Water part; Water 79.45 Silicone emulsion (antifoaming agent) 0.25 Example 6 Oil part; Ethyl = N- [2,3-dihydro-2,2-dimethylbenzofuran-7-yloxycarbonyl (10.40 methyl) Aminothio] -N-isopropyl-β-alaninate (pale yellow viscous liquid, water solubility 8 ppm) Polyoxyethylene castor oil ether 10.00 Water part; water 78.45 Silicone emulsion (antifoaming agent) 0 .25 Example 7 Oil part; diisopropyl = 1,3-dithiolane-2-ylidene-malonate (mp 54.5-55.0 ° C, 10.30 water solubility 50 ppm) Kawakazole 20.00 Polyoxyethylene castor oil ether 10.00 Water part; Water 59.45 Silicone emulsion (defoaming agent) 0.25 Example 8 Oil part; 2-chloro-2 ', 6'-diethyl-N- (methoxymethyl) acetanilide (mp 40-41) ℃, 10.30 water solubility 240ppm) Kawakazole 20.00 Polyoxyethylene castor oil ether 10.00 Water part; Water 59.45 Silicone emulsion (antifoaming agent) 0.25 Example 9 Oil part; 2-sec-butyl Phenyl-N-methyl carbamate (mp 32 ° C., water solubility 660 ppm) 10.30 Kawakazole 10 00 polyoxyethylene castor oil ether 10.00 water part; water 69.45 silicon emulsion (antifoaming agent) 0.25 Example 10 oil part; 3 ', 4'-dichloropropionanilide (mp 92-93 ° C, Water solubility 225 ppm) 5.00 Acetic acid-n-amyl acetate 7.50 Polyoxyethylene castor oil ether 10.00 Water part; Water 77.25 Silicone emulsion (antifoaming agent) 0.25 Example 11 Oil part; Dimethyldithiophosphoryl Ethyl phenylacetate (mp 17.5 ° C, water solubility 10ppm) 10.30 Polyoxyethylene castor oil ether 10.00 Water part; Water 79.45 Silicone emulsion (antifoaming agent) 0.25

[0030]

[Table 4] Viscosity until formation of gel (cps) Particle size (μm) Preparation temperature (℃) Water part added (g) ──────────────────── ───────────────── Example 5 0.14 18 5.6 Example 6 5.3 0.15 18 6.5 Example 7 0.22 18 8.0 Example 8 12.8 0.28 17 12.0 Example 9 7.4 0.21 25 11.9 Example 10 4.3 22 22 8.0 Example 11 0.13 21 6.3 --- ────────────────────────────────

[0031]

Table 5 Example NO. 5 6 7 8 9 10 11 ──────────────────────────────────── 10 days later. T. 0 0 0 0 0 0 0 0 Separation rate (%) 40 ° C 0 0 0 0 0 0 0 0 60 ° C, V 0 0 0 0 0 0 0 F. T. R. 0 0 0 0 0 0 0 30 days later. T. 0 0 0 0 0 0 0 Separation rate (%) 40 ° C 0 0 0 0 0 0 0 0 F. T. 0 0 0 0 0 0 0 ─────────────────────────────────────

Reference Example 1 20.1 parts by weight of N- (4-t-butylbenzyl) -1-methyl-3-ethyl-4-chloro-5-pyrazolecarboxamide (mp 62 ° C.), Solpol 76
05 (Toho Chemical Industry Co., Ltd. surfactant POE dialkyl phenyl ether phosphate) 5.0 parts by weight,
5.0 parts by weight of ethylene glycol (antifreezing agent), 0.5 parts by weight of Pronal EX300 (a defoaming agent manufactured by Toho Chemical Industry Co., Ltd., a silicone emulsion), Kunipia F (a thickener manufactured by Kunimine Industry Co., Ltd., Sodium)・ Montmorillonite)
1.0 part by weight and 67.5 parts by weight of water were mixed at once, and 100 g of the sample was mixed and pulverized with Dynomill KDL for 4 minutes. A 150 ml vessel was used for crushing, and beads (diameter 1.
(0 to 1.5 mm) 120 ml, peripheral speed 10 m / s (rotation speed; 3000 rpm). After grinding, the beads were removed to obtain a suspension. Test Example 4 The emulsion prepared in Example 1 and the suspension prepared in Reference Example 1 were subjected to a storage test for 1 to 14 days at room temperature (RT) and 50 ° C., respectively, and the appearance was aged. The change was visually observed with the naked eye to examine the presence or absence of liquid clogging, separation, and crystal precipitation. The results are shown in Table 6.

[0033]

[Table 6]

[0034]

The oil-in-water type agricultural chemical emulsion of the present invention has a problem of dusting when a wettable powder is used, which has been observed in conventional dispersion type preparations, during production in emulsion, during transportation, during storage, etc. It is possible to provide a pesticide formulation which is excellent in storage stability for a long period of time without causing the problem of fire risk in the above.
Further, by using the emulsion of the method of the present invention, it is possible to easily prepare an oil-in-water type pesticide raw material, for example, a pesticide raw material that is solid at room temperature by a conventional technique, which is difficult to obtain a stable emulsion. It can be an emulsion formulation.

Claims (2)

[Claims] 1. A phase inversion emulsifier comprising a pesticidal drug substance having a melting point of 100 ° C. or less and a water solubility (20 to 25 ° C.) of 0.5% by weight or less, a surfactant, and an aqueous phase. Oil-in-water agricultural chemical composition. 2. A part of the aqueous phase is added to an oil phase containing a pesticidal drug substance having a melting point of 100 ° C. or less and a water solubility (20 to 25 ° C.) of 0.5% by weight or less, and a surfactant. A method for producing an oil-in-water type agrochemical composition, which comprises adding a gel to form a gel, and then adding the remaining aqueous phase to the phase to convert from a water-in-oil type to an oil-in-water type.