JPH10139607A - Granular agrochemical wettable agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a granular agrochemical wettable agent excellent in hydra tion and solubility by formulating specific two kinds of compounds with O,S- dimethyl-N-acetylphosphorodiamidothioate. SOLUTION: This granular wettable agent is prepared by formulating dextrins having polymerization degree of 30 or less and ammonium sulfate with O, S- dimethyl-N-acetylphosphoro-diamidopthiate of active insecticidal ingredient. The using amount of low polymerized dextrins is 3-20wt.% based on the preparation weight and that of ammonium sulfate is 5-90wt.%. The phylotoxity of the wettable agent after spray is low. Further, liquid chemicals once prepared are excellent in the suspension stability and can be homogeneously sprayed with no sedimentation during spray of the liquid chemicals.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a granular pesticide containing O, S-dimethyl-N-acetylphosphoramidothioate (hereinafter referred to as "acephate") which is widely used as an agricultural and horticultural insecticide. For wettable powders. More specifically, the preparation of a chemical solution of a pesticide granular wettable powder at the time of preparation of the chemical solution facilitates the preparation of the chemical solution by facilitating hydration and solubility, and a stable insecticidal effect can be obtained by evenly applying the spray liquid to crops and pests. The present invention relates to a pesticidal granular wettable powder as described above.

[0002]

2. Description of the Related Art When a pesticide wettable powder is diluted with water to prepare a drug solution, dust may be generated. In order to solve this problem, many granulations of wettable powders have been studied, and the following granular wettable powders are known.

[0003] A granular wettable powder containing a water-soluble inorganic salt such as starch and ammonium sulfate as an active ingredient of an agricultural chemical.

[0004] Water-dispersible granules forming a good suspension, comprising a plant protective agent and a specific solid wetting agent and / or ammonium salt.

JP-A-6-92803 A water-soluble pesticide granule comprising a water-soluble pesticide active ingredient, lactose and a surfactant as essential components.

JP-A-6-128102 A granular wettable powder obtained by extruding a novel composition containing an agricultural chemical active ingredient and diatomaceous earth, preferably further containing a surfactant, by extrusion granulation.

The following are examples of solid preparations using a starch hydrolyzate.

JP, 60-36402, A starch hydrolyzate, seaweed extract, vegetable seed mucilage, vegetable fruit mucous, vegetable resinous mucous, microbial mucilage, water-soluble or water-soluble Agrochemical active ingredients and surfactants are adsorbed to a drum dryer dry powder of an aqueous dispersion of one or more polymer substances selected from the group consisting of dispersible proteins, cellulose derivatives and water-soluble synthetic polymers. A pesticidal composition in the form of a powder, characterized in that it is made to be produced by the method.

[0009] JP-A-3-47103 [0009] A pesticide containing a spray-dried aqueous emulsion containing, as essential components, an active ingredient of a pesticide having a melting point of 70 ° C or lower, a surfactant and dextrin and / or lactose and water. Solid emulsion.

[0010]

The conventional water dispersible agricultural chemical granules are poor in hydration and solubility even when poured into water, so that a complete dispersion cannot be obtained even when sufficiently stirred, There is a problem that the properties as an agent cannot be sufficiently exhibited, and it is not always satisfactory.

[0011] Therefore, there is a need for the development of a pesticidal granular wettable powder that can be hydrated and dissolved immediately when the pesticide granular wettable powder is put into water at the time of preparing a drug solution.

[0012]

Means for Solving the Problems The present inventors have made intensive studies to solve these problems. As a result, acephate was contained as an insecticidal active ingredient, and a dextrin having a degree of polymerization of 30 or less (hereinafter, referred to as “low-polymerized dextrin” unless otherwise specified) and ammonium sulfate were blended and mixed, followed by granulation by a conventional method. The water dispersible agricultural chemical granule obtained by the method described above solved the above-mentioned problems, and found that the wettability and solubility could be improved, thereby completing the present invention.

The term "degree of polymerization" used herein means an average degree of polymerization.

In the pesticidal water dispersible granules of the present invention, the particle size of the granules is not particularly limited, and in addition to the shape generally referred to as granules in the field of pesticide preparations, tablets, pills, etc. Any one of

Preparation of the pesticidal granular wettable powder is carried out using an extrusion granulator, a tumbling granulator or the like, which is usually used in formulating pesticides.

The dilution ratio of the pesticidal water dispersible powder of the present invention in water, the amount of the sprayed liquid, the method of spraying the diluent, and the like may be the same as those of a commercially available acephate wettable powder.

[0017]

[Embodiment of the present invention]

DETAILED DESCRIPTION OF THE INVENTION The pesticidal water dispersible powder of the present invention is composed of acephate, a low polymerized dextrin and ammonium sulfate as an insecticidal active ingredient.

The low-polymerized dextrin used in the present invention can be obtained by a conventional method using various starches such as wheat starch, potato starch, corn starch, and other starches such as amylose and amyloperitin degradation products, etherified starch and esterified starch. Among the dextrins obtained by hydrolysis by acid hydrolysis, alkali hydrolysis, enzymatic hydrolysis, or a combination thereof, low-polymerized dextrins having a degree of polymerization of 30 or less are obtained by a conventional method. The polymerization degree here is 3,
It may be measured by a conventional method such as a 5-dinitrosalicylic acid method.

A commercially available product containing this low-polymerized dextrin can be used.

The dextrin used in the water dispersible agricultural chemical granule of the present invention is preferably a low-polymerized dextrin having a degree of polymerization of 30 or less from the viewpoint of improving water solubility. Preferably, the degree of polymerization is 15 or less, particularly preferably 10 to 3.

Examples of these include those called maltodextrin, acrodextrin, erythrodextrin and the like, with maltodextrin being preferred. More specifically, the product names “Amicol No. 6H”, “Amicol No. 1”, “Amicol N”
o. 3L "(trade name, manufactured by Nisset Chemical Co., Ltd.) and the like.

The amount of the low-polymerized dextrin used is 3 to 20% by weight, preferably 5 to 10% by weight, based on the weight of the preparation.

The ammonium sulfate used in the present invention is:
Any form of granules or powders can be used without any problem, but powders that are easily mixed when mixed with the raw acephate powder or low-polymerized dextrin are preferable.

The amount of ammonium sulfate used is 5 to 90% by weight, preferably 30 to 50% by weight, based on the weight of the preparation.

Surfactants can be blended as required, and nonionic surfactants, anionic surfactants, cationic surfactants and amphoteric surfactants usually used in the following agricultural chemical formulations. And the like. These surfactants may be used alone or in combination.

Examples of nonionic surfactants : alkyl ether, polyoxyethylene alkyl aryl ether, polyoxyethylene styryl phenyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan alkylate, polyoxyethylene phenyl ether polymer, polyoxyethylene Aryl phenyl ether, polyoxyethylene alkylene glycol, polyoxyethylene polyoxypropylene block polymer, and the like.

Examples of anionic surfactants : lignin sulfonate, alkyl aryl sulfonate, dialkyl sulfosuccinate, polyoxyethylene alkyl aryl ether sulfate, alkyl naphthalene sulfonate, polyoxyethylene styryl phenyl ether sulfate, and the like.

Cationic and amphoteric surfactants
Examples of alkyl amine salts, quaternary ammonium salts alkyl betaines, amine oxides, and the like.

Examples of auxiliary agents that may be added as required include stabilizers for acephate, a granulating auxiliary agent added for improving granulation properties, an oil-absorbing retainer such as white carbon, and a water-diluting agent. Sometimes, a water-soluble pigment such as Food Blue No. 1 for discriminating a spray liquid is used, and these can be used in combination.

Next, the method for preparing the pesticidal granular wettable powder of the present invention will be described. However, the preparation method is not particularly limited, and the extrusion granulation method and the inverting method, which are conventionally known as a method for preparing a pesticidal solid preparation, are described. It can be prepared by a dynamic granulation method or the like. For example, in the case of the extrusion granulation method, it can be prepared, for example, by a method comprising the following steps.

Step: Raw acephate, low-polymerized dextrin, ground ammonium sulfate, and if necessary, an auxiliary agent such as a surfactant, are added and mixed well to obtain a powdery raw material composition.

Step: An appropriate amount of water is added to the powdery raw material composition, the mixture is kneaded well in a double-arm kneader, and then granulated by a basket-type extrusion granulator.

Step: After granulation, sieving and drying are performed, followed by sieving to obtain the pesticidal wettable powder of the present invention.

Next, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

In the examples, "parts" means "parts by weight".

Example 1 50 parts of raw acephate powder, 5 parts of low-polymerized dextrin (degree of polymerization: about 9 to 11) (trade name of “Amicol No. 6H” of Nisseki Chemical Co., Ltd.), ammonium sulfate (manufactured by Ube Industries, Ltd.) 45 parts are mixed together by a hammer mill (manufactured by Fuji Paudal Co., Ltd.) to obtain a powdery raw material composition. This powdery raw material composition was put into a double-arm kneader (manufactured by Fuji Paudal Co., Ltd.), and after adding 7 parts of water and kneading well, 1 mm
Basket type extrusion granulator (Nippon Pharmaceutical Co., Ltd.)
After granulation and sizing, the mixture was dried to obtain a pesticidal granular wettable powder.

Example 2 50 parts of raw acephate powder, low-polymerized dextrin (degree of polymerization: about 5 to 6) (trade name: AMICOL, manufactured by Nisse Chemical Corporation)
No. 1 ") 10 parts, 0.2 parts of polyoxyethylene (POE) nonylphenyl ether (trade name" Newcol # 560 "of a surfactant manufactured by Nippon Emulsifier Co., Ltd.)
0.01 parts of Food Blue No. 1 is added to water, and 39.79 parts of ammonium sulfate are mixed together by a hammer mill to obtain a powdery raw material composition. This powdery raw material composition is put into a double-arm kneader, 7 parts of water is added, and the mixture is kneaded well. It was dried to obtain a pesticide granular wettable powder.

Example 3 The procedure of Example 2 was repeated, except that the low-polymerized dextrin was changed to a degree of polymerization of about 3 to 4 (trade name “Amicol No. 3L” manufactured by Nissen Chemical Industry Co., Ltd.). It was prepared according to Example 2 to obtain a pesticide granular wettable powder.

Example 4 The procedure of Example 1 was repeated, except that the low-polymerized dextrin was changed to a polymerization degree of about 27 to 28 (trade name “Amicol No. 7H” manufactured by Nisseki Chemical Industry Co., Ltd.). Example 1
To obtain a pesticidal granular wettable powder.

Comparative Example 1 An agricultural chemical was prepared in the same manner as in Example 1 except that 5 parts of the low-polymerized dextrin of Example 1 was changed to 5 parts of carboxymethylcellulose (trade name “Selogen 6A” of Daiichi Kogyo Seiyaku Co., Ltd.). A granular wettable powder was obtained.

Comparative Example 2 5 parts of the low-polymerized dextrin of Example 1 was replaced with yellow dextrin (trade name “Akadama dextrin No.
102 ") It was prepared in the same manner as in Example 1 except that the amount was changed to 5 parts to obtain an agricultural chemical particulate wettable powder.

Comparative Example 3 5 parts of the low-polymerized dextrin of Example 1 was replaced with polyvinyl alcohol (trade name “GOHSENOL G” of Nippon Synthetic Chemical Company, Ltd.)
L-05S ") was prepared in the same manner as in Example 1 except that the amount was changed to 3 parts and the amount of ammonium sulfate was changed to 45 parts to obtain 47 parts of an agricultural chemical particulate wettable powder.

Comparative Example 4 An agricultural chemical granular wettable powder was obtained in the same manner as in Example 2 except that 10 parts of the low-polymerized dextrin of Example 2 was changed to 10 parts of corn starch.

Comparative Example 5 A pesticidal granular wettable powder was obtained in the same manner as in Example 2 except that 39.79 parts of ammonium sulfate in Example 2 was changed to glucose.

Comparative Example 6 The procedure of Example 2 was repeated, except that 39.79 parts of ammonium sulfate in Example 2 was changed to lactose, to give an agricultural chemical particulate wettable powder.

Comparative Example 7 A pesticidal granular wettable powder was prepared in the same manner as in Example 2 except that 39.79 parts of ammonium sulfate in Example 2 was changed to pulverized granulated sugar.

Comparative Example 8 The procedure of Example 1 was repeated, except that 45 parts of ammonium sulfate was changed to 44.8 parts of diatomaceous earth and 0.2 part of POE nonylphenyl ether to obtain a water dispersible agricultural chemical granule. .

Comparative Example 9 5 parts of the low-polymerized dextrin of Example 1 was added to 5 parts of pullulan (trade name "Trigluco A" of Hayashibara Co., Ltd.), 45 parts of ammonium sulfate were added to 44.8 parts of diatomaceous earth, and POE nonylphenyl ether 0.2 Except for having changed to a part, it prepared according to Example 1 and obtained the pesticidal granular wettable powder.

Comparative Example 10 5 parts of the low-polymerized dextrin of Example 1 was added to 5 parts of gum arabic (trade name “Arabic gum HP” of Sanshin Co., Ltd.).
Except that 45 parts of ammonium sulfate was changed to 44.8 parts of wettable clay and 0.2 part of POE nonylphenyl ether, the same procedure was followed as in Example 1 to obtain a pesticidal granular wettable powder.

Comparative Example 11 Preparation was attempted according to Example 1 except that 45 parts of ammonium sulfate in Example 1 were changed to urea. However, after granulation, the preparation could not be dried, and an agricultural chemical granular wettable powder could be obtained. Did not.

Next, the usefulness of the particulate wettable powder of the present invention will be shown by test examples.

Test Example 1 ( Measurement of physical properties of pesticide granular wettable powder ) 100 mg of each of the preparations prepared according to Examples 1 to 4 was used.
100m each containing 100ml of 3 degree hard water at 20 ° C
Put in a 1-volume stoppered graduated cylinder and let the formulation submerge in time as the hydration time, gently invert the cylinder after the formulation has settled to the bottom of the water, and determine the number of cylinder inversions until the particles are completely disintegrated. Was measured.

Then, let the cylinder stand still, and after 30 minutes,
After 60 minutes, observe the state of the diluted liquid of the pesticide granular wettable powder after 120 minutes. If there is a sediment after 120 minutes, turn the cylinder over again and observe whether the sediment is resuspended. ,
For the resuspension, the number of times of cylinder inversion until redispersion was measured to evaluate redispersibility.

For comparison, 100 mg of each of the preparations prepared in Comparative Examples 1 to 11 was measured in the same manner as in Examples 1 to 4.

As a control, a commercially available acephate wettable powder as a control was also measured in the same manner. However, the dissolution time was not measured because the dosage form was not granular.

Table 1 shows the obtained results.

[0057]

[Table 1]

[0058]

The pesticidal water dispersible powder of the present invention has the following advantages. There is no dust when the preparation is weighed or diluted with water, and the safety and workability are greatly improved compared to wettable powders. The hydration time is significantly reduced as compared to conventional wettable powders. The dissolution time is reduced as compared with the conventional granular wettable powder. Low contamination to plants after spraying chemicals. The suspension stability of the chemical solution once prepared is high, and the chemical solution can be sprayed uniformly without settling during spraying. The conventional method for producing pesticide granules can be used as it is, and the conventional technology can also be used as it is for the chemical treatment method.

Claims (1)

[Claims] 1. An insecticidal active ingredient comprising O, S-dimethyl-
N-acetyl phosphoramidothioate, having a degree of polymerization of 30
A water dispersible agricultural chemical granule characterized by comprising the following dextrin and ammonium sulfate.