JP3283552B2 - Coated granules with controlled dissolution and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a granule in which the dissolution of a pesticidal active ingredient into water is controlled, and a method for producing the same. More specifically, the present invention relates to a pesticidal active ingredient and bentonite and, if necessary, other carriers. Surfactant,
Mix and pulverize stabilizers for pesticide active ingredients to make bulk powder, water,
Alternatively, a binder obtained by combining one or more selected from the group consisting of saccharides, dextrin, hydroxypropylcellulose, carboxymethylcellulose, sodium alginate, polyvinyl alcohol, a vinyl acetate resin emulsion and an acrylic resin emulsion with water as a binder. The present invention relates to a coated granule having a controlled dissolution property, characterized in that the powder is coated on a non-disintegrating carrier, and a method for producing the same.

[0002]

2. Description of the Related Art Generally, pesticides are formulated and dispersed in powders, granules, wettable powders, emulsions and the like, and the formulation method is devised based on the solubility of the active ingredient in water. In the case of an insoluble or hardly soluble drug substance, how quickly it disperses in water to exhibit its effect, and if it is easily soluble, on the other hand, how to suppress elution and eliminate waste if necessary I have. In granules, for example, when the active ingredient is easily dissolved in water, the active ingredient is eluted in a short period of time even in wet soil containing a large amount of water as well as in water, causing phytotoxicity,
In addition, the continuity of the effect may be shortened due to the loss. In order to improve such disadvantages, the active ingredient is made into a salt structure (Japanese Patent Publication No. 42-21495) or the active ingredient is microencapsulated (Japanese Patent Laid-Open No. 48-4643).
No. 1), a first layer of liquid resin and a powder for preventing caking are formed in a second layer (Japanese Patent Publication No. 41-19080).
It contains a lipophilic base material that is solid at room temperature (Japanese Patent Laid-Open No.
No. 4356), but the production method is complicated, the production cost is high, and the control of elution is insufficient, and the desired effects, such as the manifestation of the desired effect and the maintenance, are not satisfactory. .

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel industrially useful coated granule having a controlled dissolution property and a method for producing the same.

[0004]

The present inventors have conducted various studies to achieve the above object, and as a result, have fortunately obtained a coated granule which can advantageously control the elution of an active ingredient economically and easily. Could be manufactured. Polyvinyl alcohol, a vinyl acetate resin emulsion or an acrylic resin emulsion, which is generally used as a binder of a coating type granule, has a low or almost insoluble dissolution rate in water. Elution is significantly suppressed.

According to the present invention, bentonite, which promotes the disintegration and spread of a film in water and accelerates the dissolution rate of the pesticidal active ingredient, is added to the active ingredient of the pesticidal active ingredient and pulverized into a bulk powder to obtain water or the pesticidal active ingredient. A saccharide controlling the dissolution rate of dextrin, hydroxypropylcellulose, carboxymethylcellulose, sodium alginate, polyvinyl alcohol, a vinyl acetate resin emulsion, an acrylic resin emulsion and the like in combination with water as a binder, using the above bulk powder as a binder A coated granule which is coated on non-disintegratable granules and controls the dissolution rate of an agricultural chemical active ingredient into water, and a method for producing the same. The granules of the present invention contain 1 to 30% by weight of bentonite
Containing 0.1 to 30% by weight of a binder other than water,
If necessary, the composition further contains an appropriate amount of a carrier such as amorphous silica or clay having a high oil absorbing property, a surfactant, a stabilizer for an agricultural chemical active ingredient, and the like.

[0006] The pesticidal active ingredient applicable to the present invention preferably has a solubility in water at 20 ° C of 100 ppm or less, and pesticides having the above-mentioned solubility, such as insecticides, fungicides, herbicides, etc. Does not matter. As the pesticides that can be used in the present invention, organophosphorus, carbamate,
The urea-based, heterocyclic-based, and acid-amide-based compounds and specific examples thereof are listed below, but the invention is not limited thereto. The pesticidal active ingredient may be used alone or in a combination of two or more.

O, O-dimethyl-O- [3-methyl-4
-(Methylthio) phenyl] thiophosphate (generic name: phenthione), (2-isopropyl-4-methylpyrimidyl-6) -diethylthiophosphate (generic name: diazinon), O, O-diethyl-S-2- (ethylthio) ) Ethyl phosphorodithioate (generic name: ethylthiomethone), O-2,4-dichlorophenyl O-
Ethyl S-propyl phosphorodithioate (generic name:
Prothiophos), O-ethyl-S, S-diphenyldithiophosphate (generic name: hinozan),

N- [1- (4-chlorophenyl) -ethyl] -2,2-dichloro-1,3,3-trimethylcyclopropanecarboxamide, N- [1- (4-chlorophenyl) -ethyl] -2, 2-dichloro-1-ethyl-
3-methylcyclopropanecarboxamide, N- [1-
(4-chlorophenyl) -ethyl] -2,2-dichloro-1-isopropylcyclopropanecarboxamide, N
-[1- (4-bromophenyl) -ethyl] -2,2-
Dichloro-1-isopropylcyclopropanecarboxamide, N- [1- (4-chlorophenyl) -ethyl]-
2,2-dichloro-1-methyl- (trans) -3-methylcyclopropanecarboxamide, N- [1- (4-
Chlorophenyl) -ethyl] -2,2-dichloro-1-
Ethyl-3,3-dimethylcyclopropanecarboxamide, N- (R)-[1- (4-chlorophenyl) -ethyl] -2,2-dichloro-1-ethyl-3t-methyl-
A mixture of diastereomers of 1r-cyclopropanecarboxamide,

N- (R)-[1- (4-chlorophenyl) -ethyl]-(1S) -2,2-dichloro-1-ethyl-3t-methyl-1r-cyclopropanecarboxamide, N- [1- (4-bromophenyl) -ethyl]-
2,2-dichloro-1,3,3-trimethylcyclopropanecarboxamide, N- (R)-[1- (4-chlorophenyl) -ethyl] -2,2-dichloro-1-isopropylcyclopropanecarboxamide diastereoisomer A mixture of N- (R)-[1- (4-chlorophenyl) -ethyl]-(1S) -2,2-dichloro-1-isopropylcyclopropanecarboxamide, 1- (4-
(Chlorophenoxy) -3,3-dimethyl-1- (1,
2,4-triazol-1-yl) -2-butanone (generic name: triadimefon), O-methyl O- (2-nitro-4-methylphenyl) N-isopropylphosphoramidothioate (generic name: Amipro Phosmethyl), 2-
Benzothiazol-2-yloxy-N-methylacetanilide (generic name: mefenacet)

The method for producing the coated granules of the present invention is described below. As the core of the coated granules, silica sand, calcium carbonate, clay granules, granulated non-disintegrable granules, etc. are used, and water or sugar, dextrin, hydroxypropyl cellulose, carboxymethyl cellulose, sodium alginate, polyvinyl An appropriate amount of an alcohol, a vinyl acetate resin emulsion, an acrylic resin emulsion or the like in combination with water is mixed as a binder. Next, the base of the pesticidal active ingredient manufactured by mixing and pulverizing the pesticidal active ingredient with bentonite and, if necessary, a carrier such as amorphous silica having high oil absorption properties, clay, a surfactant, a pesticide active ingredient stabilizer, etc. Add the powder, mix well, and dry to produce the product.

Examples of the core of the coated granules usable in the present invention include non-disintegrating carriers such as silica sand, calcium carbonate, pumice, clay granules and granulated non-disintegrable granules. It is not limited to this. Examples of the binder include, but are not limited to, water, sugars, dextrin, hydroxypropyl cellulose, carboxymethyl cellulose, sodium alginate, polyvinyl alcohol, vinyl acetate resin emulsion, acrylic resin emulsion, acrylic styrene copolymer resin emulsion, and the like. Not something. As the surfactant, alkyl sulfate salts, aryl sulfonates, polyoxyethylene glycol ethers,
Examples thereof include, but are not limited to, polyhydric alcohol esters, dialkyl sulfosuccinate salts, and polycarboxylic acid type surfactants. Next, examples are provided to prove the usefulness of the present invention, but the present invention is not limited only to these. The granules of the present invention were prepared by the following method.

[0012]

【Example】

Example 1 A solution obtained by dissolving a surfactant (0.50 parts by weight) and polyvinyl alcohol (0.40 parts by weight) in an appropriate amount of water was sprayed on silica sand (93.10 parts by weight), and the mixture was stirred. Wet evenly. Add bentonite (2.0
(0 parts by weight) and the active ingredient comprising the pesticidal active ingredient (I) (4.00 parts by weight) are added, stirred and mixed, and then dried. Examples 2 to 4 were similarly prepared.

[0013]

[Table 1]

Test Example Dissolution Test in Water Granules prepared in accordance with the formulations of Examples 1 to 4, 50 mg each, were placed in a beaker containing 1 liter of water, and the solution was placed at regular intervals from the center of the beaker. A part was collected, the content of the active ingredient was analyzed, and the dissolution rate was calculated.

[0015]

[Table 2]

Example 5 A solution obtained by dissolving a surfactant (0.50 parts by weight) and polyvinyl alcohol (0.40 parts by weight) in an appropriate amount of water was sprayed on silica sand (93.10 parts by weight). Stir to wet uniformly. Add bentonite (2.0
(0 parts by weight) and the bulk powder consisting of the pesticidal active ingredient (II) (4.00 parts by weight) are added, mixed with stirring, and dried. Examples 6 to 8 were similarly prepared.

[0017]

[Table 3]

Example 9 A surfactant (0.50 parts by weight) and carboxymethylcellulose (1.00 parts by weight) were added to a silica sand (92.50 parts by weight) together with an appropriate amount of water, and the mixture was stirred to uniformly wet. Let it. The raw powder consisting of bentonite (2.00 parts by weight) and the pesticidally active ingredient (III) (4.00 parts by weight) is added thereto, mixed by stirring, and dried. Examples 10 to 12
Was similarly prepared.

[0019]

[Table 4]

Example 13 A surfactant (0.50 parts by weight) and a vinyl acetate resin emulsion (0.40 parts by weight) were added to a silica sand (93.10 parts by weight) together with an appropriate amount of water, and the mixture was stirred to obtain a uniform mixture. Wet. The raw powder consisting of bentonite (2.00 parts by weight) and the pesticidally active ingredient (IV) (4.00 parts by weight) is added to the mixture, mixed with stirring, and dried. Examples 14 to 16 were similarly prepared.

[0021]

[Table 5]

Example 17 A surfactant (0.50 parts by weight) and an acrylic resin emulsion (0.40 parts by weight) were added to a silica sand (93.10 parts by weight) together with an appropriate amount of water, and the mixture was stirred to obtain a uniform mixture. Let it wet. The raw powder consisting of bentonite (2.00 parts by weight) and the pesticidal active ingredient (V) (4.00 parts by weight) is added thereto, mixed with stirring, and dried. Examples 18 to 20 were similarly prepared.

[0023]

[Table 6]

Test Example Dissolution test in water Granules prepared according to the formulations of Examples 5 to 20, 50 mg each,
The solution was charged into a beaker containing 1 liter of water, and at regular intervals, a part of the solution was collected from the center of the beaker, the content of the active ingredient was analyzed, and the elution rate was calculated.

[0025]

[Table 7]

[0026]

[Table 8]

[0027]

[Table 9]

[0028]

[Table 10]

(Note) The pesticidal active ingredients (I) to (V) in each Example are as follows. (I): 2-benzothiazol-2-yloxy-N-
Methylacetanilide (II): N- [1- (4-chlorophenyl) -ethyl]
-2,2-dichloro-1-ethyl-3-methylcyclopropanecarboxamide (III): N- [1- (4-chlorophenyl) -ethyl]
-2,2-dichloro-1-isopropylcyclopropanecarboxamide (IV): N- (R)-[1- (4-chlorophenyl)-
Mixture of diastereomers of ethyl] -2,2-dichloro-1-ethyl-3t-methyl-1r-cyclopropanecarboxamide (V): N- (R)-[1- (4-chlorophenyl)-
Mixture of diastereomers of [ethyl] -2,2-dichloro-1-isopropylcyclopropanecarboxamide

As is apparent from the above Examples and Test Examples, the present invention promotes the disintegration and spread of the film and reduces the dissolution rate of the pesticidal active ingredient in coating the non-degradable carrier with the pesticidal active ingredient. By changing the composition ratio of the accelerated bentonite and the binder that significantly suppresses the elution of the active ingredient into water, the elution of the pesticidal active ingredient can be controlled, and the desired concentration in water and the duration of the drug effect can be measured. Therefore, the active ingredient can be used for a long period of time within a concentration range that does not cause harm. This makes it possible to spray chemicals in a nursery box that is indispensable for mechanical transplantation, which is currently the mainstream in the form of rice cultivation, thereby saving labor.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-53-118526 (JP, A) JP-A-62-263101 (JP, A) JP-A-2-40301 (JP, A) JP-A 48-48 18435 (JP, A) JP-A-60-237007 (JP, A) JP-A-64-56601 (JP, A) Sumitomo Chemical 1982-II pp. 3 to 19 (58) Fields investigated (Int. . ^7, DB name) A01N 25/26 A01N 25/08 A01N 25/10 A01N 25/14

Claims (2)

(57) [Claims] Claims: 1. In a dissolution-controlling granule, an active ingredient of pesticide and bentonite are mixed and pulverized as essential components to obtain a raw powder,
Water or a saccharide, dextrin, hydroxypropylcellulose, carboxymethylcellulose, sodium alginate, polyvinyl alcohol, a vinyl acetate resin emulsion, a combination of water and one or more selected from the group consisting of acrylic resin emulsion as a binder, A coated granule having controlled dissolution, characterized by coating the above-mentioned bulk powder on a non-disintegrating carrier. 2. In a dissolution-controlling granule, an active ingredient of pesticide and bentonite are mixed and pulverized as essential components to obtain a raw powder,
Water or a saccharide, dextrin, hydroxypropylcellulose, carboxymethylcellulose, sodium alginate, polyvinyl alcohol, a vinyl acetate resin emulsion, a combination of water and one or more selected from the group consisting of acrylic resin emulsion as a binder, A method for producing a coated granule with controlled dissolution, characterized by coating the bulk powder on a non-disintegrating carrier.