JP4068688B2 - Granules for paddy fields containing active ingredients of poorly water-soluble pesticides - Google Patents

Description

SSF−129を室温でN−メチルピロリドンに溶解し、この溶液にソルポール5060及びSAS−296を撹拌下、注加して乳剤を得た。

上記の混合物を押し出し造粒法にて空粒剤(平均粒子径１.２mm）を調製した。
（３）SSF−129粒剤
上記（１）の乳剤を（２）で調製した空粒剤に撹拌下滴下し、含浸させ、２％粒剤を得た。この粒剤の水中浮遊率は２％以下であった。
農薬有効成分の水面浮遊率の測定は以下の方法で行った。
粒剤５０mgを３度硬水１Ｌの入ったビーカーに添加した。２時間後、水面上に濾紙をそっと置くことによって、水面上に浮遊している有効成分を濾紙に吸着させた。約３０秒後に濾紙を回収し、同紙からアセトニトリルで有効成分を抽出後、ＨＰＬＣにて定量した。
【００１１】
実施例２ トリシクラゾールを含有する粒剤

トリシクラゾールを室温でN−メチルピロリドンに溶解し、この溶液にニューカルゲンTG−74及びソルベッソ#200を撹拌下、注加して乳剤を得た。

上記の混合物を押し出し造粒法にて空粒剤(平均粒子径１.２mm）を調製した。
（３）トリシクラゾール粒剤
上記（１）の乳剤を（２）で調製した空粒剤に撹拌下滴下し、含浸させ、３％粒剤を得た。この粒剤の水中浮遊率は２％以下であった。
【００１２】
参考例１ チフルザミドを含有する粒剤

チフルザミドを室温でN−メチルピロリドンに溶解し、この溶液にニューカルゲンP−150及びSAS−296を撹拌下、注加して乳剤を得た。

上記の混合物を押し出し造粒法にて空粒剤(平均粒子径１.２mm）を調製した。（３）チフルザミド粒剤
上記（１）の乳剤を（２）で調製した空粒剤に撹拌下滴下し、含浸させ、２％粒剤を得た。この粒剤の水中浮遊率は約２％以下であった。
【００１３】
上記の実施例又は参考例で調製した粒剤中の乳剤、農薬有効成分、極性溶剤、非極性溶剤の含有量を以下の表にまとめて示す。
【表１】

【００１４】
上記実施例１及び２、及び参考例１で用いた乳化性付与基剤の比重（理論値）を、以下に示す各成分の比重から求めた。結果を表２に示す。

【表２】

【００１５】
試験例１ 農薬有効成分の溶出試験
実施例、又は参考例で調製した粒剤５０mgを３度硬水１Ｌの入ったビーカーに添加し、２時間後にスパーテルで１分間に２０回の速度で２０回撹拌した後、ビーカーの中央部より２mlを採取し、定量用被検液とした。
この被検液を以下の条件下、クロマトグラフィーで定量した。
ＨＰＬＣ測定条件
カラム：ＹＭＣパック ODS-A,4.6X150mm 測定波長：230nm
移動相：SSF-129用 CH₃CN:H₂O=55:45 トリシクラゾール用 MeOH:H₂O=50:50
流速：SSF-129用 1.5ml/min トリシクラゾール用 1.0ml/min
結果を以下の表３に示す。
なお、比較のために、下記の有効成分、崩壊・拡展剤及び担体成分を記載した比率で用い、押し出し造粒法で調製した粒剤（比較例１及び３）又は市販の粒剤（比較例２）を用いた。

比較例２：トリシクラゾールの市販粒剤（ビームS粒剤、含量４％；ダウケミカル日本）

【００１６】
【表３】

1) 2時間後
上記の結果は、本発明の粒剤から、迅速に有効成分が溶出し、その水中濃度が上昇することを示している。
【００１７】
試験例２ 粒剤の即効性の評価
試験菌： イネいもち病菌（Pyricularia oryzae race 003)
試験植物：イネ（愛知旭）
被検薬物：実施例１のSSF-129の２％粒剤、実施例２のトリシクラゾールの３％粒剤、上記試験例１に記載の比較例１の２％粒剤及び比較例２の４％粒剤

方法
育苗箱に種籾を播種後、８日目に300ml容カップに苗を移植し、さらに５日間湛水状態で育苗した。次いで、実施例で調製した粒剤を上記の薬量で水面施用した。菌の接種を薬剤処理当日及び１日後に行った。５日後、発病面積を測定することにより、防除率（％）を計算した。結果を以下の表４に示す。
【表４】

上記の結果は、本発明の粒剤の場合には、イネいもち病菌に対する効果が迅速に現れ、しかも防除効果が高いことを示している。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a granule for paddy fields containing a poorly water-soluble pesticide active ingredient, and more particularly to a granule which can rapidly exhibit activity when applied to paddy fields.
[0002]
[Prior art and problems to be solved by the invention]
When a poorly water-soluble pesticide is applied to paddy fields, it takes time to reach the effective water concentration of the pesticide. For this reason, in order to express a sufficient disease control effect, it was necessary to apply an agrochemical or to apply a high dose considerably before the disease occurrence time. Therefore, in order to efficiently control with the smallest possible amount of drug, it is necessary to use a preparation that rapidly increases the concentration in water.
Conventionally, as an agrochemical formulation containing a poorly water-soluble agrochemical active ingredient, for example, 1) Agricultural solid formulation (Japanese Patent Publication No. 6-39362), 2) Improved agricultural granules and fine granules (Japanese Patent Publication No. 7-106961) 3) blight control composition (JP-A-6-336402), 4) readily dispersible emulsifiable solid agrochemical (JP-A-5-221803), 5) easily dissolvable emulsifiable powder in water (Japanese Patent Publication 3- 76281), 6) Agricultural granules for paddy field (Japanese Patent Laid-Open No. 9-12406) and the like have been disclosed, but these conventional techniques cannot solve the above-mentioned problems. That is, 1) is a preparation relating to an agrochemical active ingredient having a low melting point (0 to 65 ° C.) and has a limited application range. In addition, 2) is a field granule, which is irrelevant to the rapid efficacy at the time of paddy field application. 3) is a surface-floating formulation, and the effect of increasing the concentration in water cannot be expected due to the rapid dispersion of the active ingredient in water after application to paddy fields. 4) is a formulation that easily releases and separates active ingredients using alkaline substances. It is not applicable to active ingredients that are unstable to alkali, and there are problems with the safety of workers and the impact on the environment. Yes, 5) is a preparation in which a liquid containing an active ingredient is occluded in a thermally expanded rock granule, but rapid dissolution of the active ingredient in water cannot be expected. In addition, 6) discloses a granule in which a solution in which a poorly water-soluble pesticide active substance is dissolved in a water-insoluble organic solvent is supported on a carrier. This granule has a specific gravity adjusted to less than 1.0. Since it is a surface-floating type preparation, it is unsuitable for the purpose of rapidly increasing the concentration of the active substance in water.
Under these circumstances, after applying to paddy fields, the active ingredient is quickly released in large quantities by releasing the active ingredient of agricultural chemicals and increasing its concentration in water, resulting in a rapid effect. Development of a preparation containing a faster-acting slightly water-soluble pesticide active ingredient has been strongly desired.
[0003]
[Means for Solving the Problems]
As a result of earnest and research to solve the above-mentioned problems and provide a fast-acting pesticide formulation for paddy fields containing a poorly water-soluble pesticide active ingredient, the present inventors have found that the emulsion of the active ingredient is applied to fats and oils. The present inventors have found that the above-mentioned problems can be solved by supporting a carrier containing hydrophilic silicon dioxide having high affinity, and have completed the present invention.
That is, the present invention is characterized by impregnating a water-containing granule containing hydrous silicon dioxide with an emulsion obtained by dissolving a slightly water-soluble pesticide active ingredient (excluding tifluzamide) in an emulsifying agent in water. An easily emulsifiable and dispersible paddy granule for water is provided.
[0004]
Although it does not specifically limit as a poorly water-soluble agricultural chemical active ingredient contained in the grain for paddy fields of this invention (henceforth only a granule), It is soluble in the polar solvent contained in an emulsion base. Is preferred. Further, a high melting point component having a melting point of 70 ° C. or higher is also included. For example, (E) -2- [2- (2,5-dimethylphenoxy) methylphenyl] -2-methoxyimino-N-methylacetamide (hereinafter referred to as “E) -2- [2- (2,5-dimethylphenoxy) methylphenyl] -2-methoxyimino-N-methylacetamide” , SSF-129) (melting point 134 ° C., water solubility 2.8 ppm at 25 ° C.), 5-methyl-1,2,4-triazolo [3,4-b] benzothiazole (generally called tricyclazole) (melting point 187− 188 ° C, water solubility 1.6 ppm at 25 ° C) and 2 ', 6'-dibromo-2-methyl-4'-trifluoromethoxy-4-trifluoromethyl-1,3-thiazole-5-carboxyanilide (generic name) Tifluzamide) (melting point 177-178 ° C, water solubility 1.5ppm), pyrazolate (melting point 117.5-118.5 ° C, water solubility 0.056ppm at 25 ° C), benzophenap (melting point 131-133.5 ° C, water solubility 0.13ppm at 25 ° C) , Clomethoxynil (melting point 113-114 ° C, water solubility 0.3ppm at 15 ° C), bifenox (melting point 84-86 ° C, Water solubility 0.35 ppm at 25 ° C., flutolanil (melting point 108 ° C., water solubility 9.6 ppm at 20 ° C.), and pencyclone (melting point 132-133 ° C., water solubility 0.5 ppm).
[0005]
Since the granules of the present invention are not easily floating in water but are easily emulsifiable and dispersible in water, the specific gravity of the emulsifying base in water is preferably 1.0 or more, and an active ingredient of agricultural chemical is dissolved in the base. The specific gravity of the emulsion obtained is preferably 1.0 or more.
The underwater emulsification-imparting base contains a polar solvent, a nonpolar solvent and an emulsifier, and may contain other additives as necessary.
The ratio of the polar solvent to the nonpolar solvent in the base is in the range of 1: 1 to 1:20, preferably 1: 3 to 1:15 by weight ratio.
The amount of the polar solvent is 1 to 10%, preferably 2 to 5%, and the amount of the nonpolar solvent is 10 to 20%, preferably 12 to 18% based on the total weight of the granule.
[0006]
The polar solvent capable of dissolving the agricultural chemical active ingredient is appropriately selected from known polar organic solvents, but is selected from the group consisting of N-methyl-2-pyrrolidone, N-octyl-2-pyrrolidone, cyclohexanone and methyl ethyl ketone. One or more solvents are preferred.
The nonpolar solvent is also selected from known nonpolar organic solvents, but 1-phenyl-1-xylylethane (trade name Hysol SAS-296, Nippon Petrochemical Co., Ltd.), Solvesso # 100 (trade name, Exxon Chemical Co., Ltd.) , Solvesso # 150 (same as above), Solvesso # 200 (same as above), n-paraffin, cyclohexane, diethylbenzene, triethylbenzene, cumene, xylene, methylnaphthalene, benzyl ether, octyl adipate, butyl stearate, butyl laurate, One or more solvents selected from the group consisting of soybean oil, castor oil, olive oil and rapeseed oil are preferred.
[0007]
The emulsifier used in the production of the emulsion can be arbitrarily selected from emulsifiers commonly used in the technical field relating to agricultural chemical formulations. For example, Solpol 3880H (POE styryl phenyl + POE styryl phenyl ether polymer + alkyl allyl sulfonate; Toho Chemical Industry) ), Solpol 355L (POE styryl phenyl + alkyl allyl sulfonate; Toho Chemical Industry), New Calgen TG-74 (POA allyl phenyl ether sulfate NH ₄ + Na alkylbenzene sulfonate; Takemoto Yushi) and New Calgen P-150 (POA allyl phenyl) Ether sulfate NH ₄ ; Takemoto fats and oils) and the like, and New Calgen P-150 is preferable.
A combination and blending ratio of the polar solvent, the nonpolar solvent and the emulsifier are arbitrarily selected on the condition that the specific gravity of the emulsification-imparting base which is preferably a mixture thereof is 1.0 or more.
The emulsion is obtained, for example, by dissolving a selected poorly water-soluble agricultural chemical active ingredient in a polar solvent and adding an emulsifier and a nonpolar solvent thereto.
[0008]
The empty granule is a known method such as extrusion granulation method, tumbling granulation method, stirring granulation method, fluidized bed granulation method, etc., suitably mixed with hydrous silicon dioxide, mineral substance carrier and disintegration / spreading agent. For example, it is prepared by granulating into granules having an average particle diameter of 0.8 to 1.2 mm.
The larger the amount of hydrous silicon dioxide in the empty granule, the greater the amount of emulsion containing an active ingredient for agricultural chemicals can be impregnated. In consideration of the hardness of the granule and its disintegration in water, The amount of the hydrous silicon dioxide is 10 to 35%, preferably 15 to 30% of the total weight of the granule.
Hydrous silicon dioxide, also called white carbon, includes Carplex # 80, Carplex # 80-D, Carplex # 1120 (Yoshio Shionogi), Toxeal N, Toxeal P (Tokuyama Soda), Aerosil R972 (Nippon Aerosil), etc. Commercial products can be used.
As mineral carriers, clay (eg, Keiwa Fine Clay; Keiwa Furnace Co., Ltd.), calcium carbonate, potassium chloride, talc, kaolin, diatomaceous earth, gypsum, bentonite (eg, Kunigel VI; Kunimine Industries), etc. These may be used alone or in combination of two or more.
Disintegrating and spreading agents include polycarboxylic acid surfactants such as Toxanone GR-31A (Sanyo Kasei Kogyo) and Newkargen-TG33 (Takemoto Yushi), and polycarboxylic acids such as Newkargen-TG250 (Takemoto Yushi) And a mixture of naphthalenesulfonic acid surfactants, polyacrylic acid surfactants such as Boise 530 (Kao), and sulfonate type / phosphate salts such as Solpol 5060 (Toho Chemical Industries).
[0009]
In order to prepare the granule of the present invention, the emulsion containing an active ingredient for agricultural chemicals is dropped and impregnated into an empty granule with stirring as necessary. Since silicon dioxide contained in the empty granule has a high affinity for fats and oils, it can support a large amount of emulsion and can support up to about 40% (W / W). The granule of the present invention contains an active ingredient of an agricultural chemical in the form of an emulsion and has a specific gravity of 1 or more. Therefore, when applied to a paddy field, it immediately disperses in water as fine emulsion particles and the concentration in water increases. . Therefore, when the preparation of the present invention is used prophylactically, a sufficient control effect can be expected even after the occurrence of disease.
[0010]
Typical examples of the present invention are shown below, but the present invention is not limited thereto. The content (%) of each component indicates a value relative to the total weight of the granule.
Example 1 Granules containing SSF-129

SSF-129 was dissolved in N-methylpyrrolidone at room temperature, and Solpol 5060 and SAS-296 were added to this solution with stirring to obtain an emulsion.

An empty granule (average particle size 1.2 mm) was prepared by extruding the above mixture.
(3) SSF-129 granules The emulsion of (1) above was added dropwise to the empty granules prepared in (2) with stirring and impregnated to obtain 2% granules. The underwater floating rate of this granule was 2% or less.
The water surface floatation rate of the agricultural chemical active ingredient was measured by the following method.
50 mg of granules were added to a beaker containing 1 L of hard water 3 times. After 2 hours, the active ingredient floating on the water surface was adsorbed on the filter paper by gently placing the filter paper on the water surface. After about 30 seconds, the filter paper was collected, and the active ingredient was extracted from the paper with acetonitrile, followed by quantitative determination by HPLC.
[0011]
Example 2 Granules containing tricyclazole

Tricyclazole was dissolved in N-methylpyrrolidone at room temperature, and Neukalgen TG-74 and Solvesso # 200 were added to this solution with stirring to obtain an emulsion.

An empty granule (average particle size 1.2 mm) was prepared by extruding the above mixture.
(3) Tricyclazole granules The emulsion of (1) above was added dropwise to the empty granules prepared in (2) with stirring and impregnated to obtain 3% granules. The underwater floating rate of this granule was 2% or less.
[0012]
Reference Example 1 Granules containing tifluzamide

Tifluzamide was dissolved in N-methylpyrrolidone at room temperature, and Neukargen P-150 and SAS-296 were added to this solution with stirring to obtain an emulsion.

An empty granule (average particle size 1.2 mm) was prepared by extruding the above mixture. (3) Tifluzamide granules The emulsion of (1) above was added dropwise to the empty granules prepared in (2) with stirring and impregnated to obtain 2% granules. The water suspension of this granule was about 2% or less.
[0013]
The contents of the emulsion, the agricultural chemical active ingredient, the polar solvent, and the nonpolar solvent in the granules prepared in the above Examples or Reference Examples are summarized in the following table.
[Table 1]

[0014]
The specific gravity (theoretical value) of the emulsifying agent used in Examples 1 and 2 and Reference Example 1 was determined from the specific gravity of each component shown below. The results are shown in Table 2.

[Table 2]

[0015]
Test Example 1 Dissolution test of active ingredients of agricultural chemicals 50 mg of the granules prepared in Examples or Reference Examples were added to a beaker containing 1 L of hard water 3 times, and stirred 20 times at a rate of 20 times per minute with a spatula 2 hours later. After that, 2 ml was collected from the center of the beaker and used as a test solution for quantification.
This test solution was quantified by chromatography under the following conditions.
HPLC measurement column: YMC pack ODS-A, 4.6X150mm Measurement wavelength: 230nm
Mobile phase: For SSF-129 CH ₃ CN: H ₂ O = 55: 45 For tricyclazole MeOH: H ₂ O = 50: 50
Flow rate: 1.5ml / min for SSF-129 1.0ml / min for tricyclazole
The results are shown in Table 3 below.
For comparison, granules (Comparative Examples 1 and 3) prepared by an extrusion granulation method or commercially available granules (comparison) were used in the ratios described below for the following active ingredients, disintegration / spreading agents and carrier components. Example 2) was used.

Comparative Example 2: Commercially available granule of tricyclazole (Beam S granule, content 4%; Dow Chemical Japan)

[0016]
[Table 3]

1) After 2 hours, the above results indicate that the active ingredient is rapidly eluted from the granules of the present invention, and the concentration in water increases.
[0017]
Test Example 2 Evaluation of immediate effect of granules
Test fungus : Rice blast fungus ( Pyricularia oryzae race 003)
Test plant : Rice (Aichi Asahi)
Test drug : 2% granule of SSF-129 of Example 1, 3% granule of tricyclazole of Example 2, 2% granule of Comparative Example 1 described in Test Example 1 and 4% of Comparative Example 2 Granule

Method After seed pods were sowed in a seedling box, seedlings were transplanted into a 300 ml cup on the 8th day, and further bred for 5 days. Next, the granules prepared in the examples were applied to the water surface at the above doses. The bacteria were inoculated on the day of drug treatment and one day later. After 5 days, the disease control area (%) was calculated by measuring the disease area. The results are shown in Table 4 below.
[Table 4]

The above results show that in the case of the granule of the present invention, the effect on rice blast fungus appears rapidly and the control effect is high.

Claims (9)

An easily emulsifiable and dispersible granule for paddy fields, wherein an emulsion in which SSF-129 or tricyclazole is dissolved in an emulsifying agent in water is impregnated in a hollow granule containing hydrous silicon dioxide.   The granule for paddy fields according to claim 1, wherein the specific gravity of the emulsifying agent in water is 1.0 or more.   The granule for paddy fields according to claim 1, wherein the specific gravity of the emulsion is 1.0 or more. The granule for paddy fields according to claim 1, wherein the emulsifying agent in water contains a polar solvent, a nonpolar solvent and an emulsifier in which SSF-129 or tricyclazole is soluble. The proportion of polar solvent and a nonpolar solvent is 1: 1 to 1: paddy for granules according to claim 4 is in the range of 20.   The granule for paddy fields according to claim 4, wherein the polar solvent is one or more solvents selected from the group consisting of N-methyl-2-pyrrolidone, N-octyl-2-pyrrolidone, cyclohexanone and methyl ethyl ketone.   Non-polar solvent is 1-phenyl-1-xylylethane, Solvesso # 100, Solvesso # 150, Solvesso # 200, Cyclohexane, Diethylbenzene, Triethylbenzene, Cumene, Xylene, Methylnaphthalene, Benzyl ether, Octyl adipate, Butyl stearate, Lauryl The granule for paddy fields according to claim 4, which is one or more solvents selected from the group consisting of butyl acid, soybean oil, castor oil, olive oil and rapeseed oil. The granule for paddy fields according to claim 1, wherein the emulsion is obtained by emulsifying a polar solvent solution of SSF-129 or tricyclazole in a nonpolar solvent in the presence of an emulsifier.   The granule for paddy fields according to claim 1, wherein the content of hydrous silicon dioxide is 10 to 35% of the total weight of the granule.