JP2001192305A - Pesticide particles for coated pesticide granules and coated pesticide granules using the pesticide particles - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pesticide particle for a coated pesticide granule capable of correcting the pH of the pesticide particle without impairing the original swelling power of montmorillonite, and a coated pesticide granule using the pesticide particle. Offer. SOLUTION: The content of the acidic substance in the pesticide particles for coated pesticide granules comprising montmorillonite, an acidic substance and a pesticide component is adjusted to the range of 0.01 to 5% by weight based on the pesticide particles, and the coating is performed. The surface of pesticide particles for pesticide granules
It is coated with a resin-containing coating material to obtain a coated pesticide granule.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a pesticide particle for coated pesticide granules, and a coated pesticide granule using the same. More specifically, pesticide particles for a coated pesticide granule containing montmorillonite, an acidic substance, and a pesticide component (hereinafter referred to as “core material”), and a coated pesticide in which the surface of the core material is coated with a coating material containing a resin For granules.

[0002]

2. Description of the Related Art Pesticide spraying for the purpose of controlling pests and insects is performed by:
There are many types of pesticide components to be used, and the frequency of spraying for each pesticide component is large. On the other hand, for the purpose of reducing the burden of spraying the pesticide, pesticide granules having a function of sustained release of the pesticide component have been developed.

[0003] Among them, coated pesticide granules obtained by coating the surface of pesticide particles containing a pesticide component with a coating material containing a resin are promising pesticide granules. Specific examples of the pesticide granules include coated pesticide granules (JP-A-9-77608) in which the film is disintegrated by the swelling power of montmorillonite to release the internal pesticide active ingredient. The coated pesticide granule is a promising material because the coating operation is simple and the production equipment is inexpensive.

[0004]

However, when the pesticide particles to be coated are produced by granulating a pesticide component together with montmorillonite, montmorillonite generally shows alkalinity, so that the original pesticide activity is reduced. In some cases it was impaired. In particular, it was remarkable when a pesticide component that was unstable under alkaline conditions was used.

[0005] In such a case, it is conceivable to correct the pH by adding an acidic substance to the pesticide particles in order to maintain the pesticide activity. As is clear from the description of “Crystalline swelling of montmorillonite—use of electrolyte for controlling swelling” on page 255, vol. 173, No. 437, generally, the addition of an electrolyte such as an acidic substance to montmorillonite causes It has been reported that the pH is lowered, and the correction of pH by adding an acidic substance to pesticide particles for coated pesticide granules containing montmorillonite and pesticide components has not been performed so far.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, it has been found that the present invention provides a coated pesticide particle comprising montmorillonite, an acidic substance and a pesticide component, When the content is in the range of 0.01 to 5% by weight with respect to the pesticide particles, it has been found that the pH of the pesticide particles can be corrected without impairing the original swelling power of montmorillonite. The present invention has been completed based on this finding.

The present invention comprises the following (1) to (7). (1) Coated pesticide particles for coated pesticides comprising montmorillonite, an acidic substance, and a pesticide component, wherein the content of the acidic substance is in the range of 0.01 to 5% by weight based on the pesticide particles. For pesticide particles.

(2) The pesticide particles for coated pesticide granules according to the above (1), wherein the acidic substance is at least one selected from the group consisting of phosphoric acid and phosphate.

(3) The first method, wherein the acidic substance is citric acid.
4. The pesticide particles for coated pesticide granules according to item 1.

(4) The circularity coefficient obtained from the following equation is 0.
4. The pesticide particles for coated pesticide granules according to any one of the above items 1 to 3, which are 7 or more. Circularity coefficient = (4π × projected area of particle) / (length of contour of particle projected view) ²

(5) A coated pesticide granule obtained by coating the surface of the coated pesticide particles for agrochemicals according to any one of the above items 1 to 4 with a coating material containing a resin.

(6) The coated pesticide granule according to the above (5), wherein the resin is an olefin polymer.

(7) A time period in which the coated pesticide granule comprises a release suppression period in which the release of the pesticide active ingredient is suppressed for a certain period after application, and a release period in which the release of the pesticide active ingredient continues after the release suppression period has elapsed. 7. The coated pesticide granule according to the above item 5 or 6, having a release type sustained release function.

Hereinafter, the present invention will be described in detail. The montmorillonite used in the present invention has a sandwich-like three-layer structure (2: 1 type) in which one alumina octahedral sheet is sandwiched between two silicate tetrahedral sheets. It is a clay mineral which is composed of a crystal lattice in which trivalent aluminum of the sheet is partially substituted by magnesium or iron having a lower valence and has a swelling property in water absorption. Further, montmorillonite is 80% Also includes clay minerals contained above. In the present invention, one kind may be selected from these montmorillonite and used.
More than one species may be selected and used.

Specific examples of the montmorillonite include acid clay and bentonite. Bentonite is preferred as the montmorillonite used in the present invention. Bentonite has a large swelling power when absorbing water, and when using bentonite, it is easy to control the collapse of the coated pesticide granule coating.

Bentonite is rich in sodium ions and absorbs a large amount of water to exhibit high swelling properties, such as sodium-based bentonite, calcium- and magnesium-ions, low-swelling calcium-based bentonite, and has a swelling activity by soda treatment. There are three types of artificially applied activated bentonite.

Also, the swelling power of bentonite varies depending on the content of montmorillonite, and the properties and quality vary depending on the place of production and the product. Furthermore, the swelling power varies depending on the particle size. It is preferable to select and use as appropriate. In the present invention, it is preferable to use sodium bentonite having high swellability. Specific examples include Bentonite Fuji, Bentonite Hotaka, Bentonite New Hotaka, Bentonite Akagi, Bentonite Asama, Bentonite Haruna,
Super Clay, Kunimine Industries Kunipia F, Smecton SA, Kunigel V1, Kunigel V2, Kunigel V
A, Kunibond, Neo Kunibond, Japan Bentonite M-1, Aso, Takachiho 1, Takachiho 2, Unzen,
KG, KA-1, and KG-1 can be mentioned.

The content of montmorillonite contained in the core of the present invention is preferably in the range of 20 to 80% by weight based on the weight of the core.

The agricultural chemical component used in the present invention is not particularly limited, but mainly has an action of killing insects, killing nematodes, etc. in addition to insecticide, sterilization, weeding, and plant growth regulation. In addition, they also include repellents and attractants. The content of the agrochemical component contained in the core of the present invention is preferably in the range of 0.5 to 30% by weight based on the weight of the core.

Specific examples of the insecticide include (E) -N ^1-
[(6-Chloro-3-pyridyl) methyl] -N ² -cyano-N ¹ -methylacetamidine (generic name: acetamiprid), 1- (6-chloro-3-pyridylmethyl) -N
-Nitroimidazolidin-2-ylideneamine (generic name: imidacloprid), O, O-diethyl-S-2-
(Ethylthio) ethyl phosphorodithioate (generic name:
Ethylthiomethone), 2,3-dihydro-2,2-dimethyl-7-benzo [b] furanyl = N-dibutylaminothio-N-methylcarbamate (general name: carbosulfan), (E) -N- ( 6-chloro-3-pyridylmethyl) -N-ethyl-N'-methyl-2-nitrovinylidenediamine (generic name: nitenpyram);

(±) -5-amino- (2,6-dichloro-α, α, α-trifluoro-p-toluyl) -4-trifluoromethylsulfinylpyrazole-3-carbonitrile (generic name: fipronil) , Butyl = 2,3-
Dihydro-2,2-dimethylbenzofuran-7-yl =
N, N'-dimethyl-N, N'-thiodicarbamate (general name: furatiocarb), ethyl = N- [2,3-
Dihydro-2,2-dimethylbenzofuran-7-yloxycarbonyl (methyl) aminothio] -N-isopropyl-β-alaninate (generic name: benflacarb);
And 1-naphthyl-N-methyl carbamate (generic name: NAC).

As a bactericide, (1RS, 3SR) -2,
2-dichloro-N- [1- (4-chlorophenyl) ethyl] -1-ethyl-3-methylcyclopropanecarboxamide (generic name: carpropamide), 5-methyl-1,
2,4-triazolo [3,4-b] benzothiazole (generic name: tricyclazole), 1,2,5,6-tetrahydropyrrolo [3,2,1-ij] quinolin-4-one (generic name: pyroquilon ), (RS) -5-chloro-N
-(1,3-dihydro-1,1,3-trimethylisobenzofuran-4-yl) -1,3-dimethylpyrazole-4-carboxamide (common name: flametopyr), and 3-allyloxy-1,2-benzoyl Isothiazole-
Examples thereof include 1,1-dioxide (generic name: probenazole).

As the herbicides, 2-chloro-4-ethylamino-6-isopropylamino-s-triazine (general name: atrazine), 1- (2-chloroimidazo [1,2
-A] pyridin-3-ylsulfonyl) -3- (4,6
-Dimethoxypyrimidin-2-ylurea (generic name: imazosulfuron), S-benzyl = 1,2-dimethylpropyl (ethyl) thiocarbamate (generic name: esprocarb), ethyl = (RS) -2- [4- ( 6-chloroquinoxalin-2-yloxy) phenoxy] propionate (generic name: quizalofop butyl), butyl = (R)
-2- [4- (4-cyano-2-fluorophenoxy)
Phenoxy] propionate (generic name: cyhalofop butyl), 2-methylthio-4-ethylamino-6-
(1,2-dimethylpropylamino) -s-triazine (generic name: dimethamethrin), 2-methylthio-4,6
-Bis (ethylamino) -s-triazine (generic name: simetryn),

1- (α, α-dimethylbenzyl) -3-
(Paratolyl) urea (generic name: Daimulon), 2-chloro-N- (3-methoxy-2-thenyl) -2 ′, 6′-
Dimethylacetanilide (generic name: tenylchlor),
α- (2-naphthoxy) propionanilide (generic name:
Naproanilide), methyl 3-chloro-5- (4,6
-Dimethoxypyrimidin-2-ylcarbamoylsulfamoyl) -1-methylpyrazole-4-carboxylate (generic name: halosulfuronmethyl), ethyl = 5-
(4,6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl) -1-methylpyrazole-4-carboxylate (generic name: pyrazosulfuronethyl), S
-(4-chlorobenzyl) -N, N-diethylthiocarbamate (generic name: benchthiocarb), methyl = α-
(4,6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl) -o-toluate (generic name: bensulfuronmethyl), 2-benzothiazol-2-yloxy-N-methylacetanilide (generic name: mefenacet) and the like. Can be mentioned.

The acidic substance used in the present invention is an acid and a salt which is acidic in an aqueous solution. The acidic substance used in the present invention may be one kind or two or more kinds. An acid is a substance that releases hydrogen ions, and a salt that is acidic in an aqueous solution means that when the salt is dissolved in water, a part of the salt returns to the original acid or base (by hydrolysis of the salt). Is an acidic salt.

Specific examples of the acid include various inorganic acids and organic acids such as hydrochloric acid, sulfuric acid, phosphoric acid, carboxylic acid and sulfonic acid.

Specific examples of the salt exhibiting acidity in an aqueous solution include:
Examples thereof include monoammonium phosphate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, calcium bis (dihydrogen phosphate), ammonium chloride, and magnesium sulfate.

In the present invention, among these acidic substances, it is preferable to use one or more selected from phosphoric acid and phosphate, or an organic acid.

Specific examples of the phosphate include sodium dihydrogen phosphate, potassium dihydrogen phosphate, sodium tripolyphosphate, sodium hexametaphosphate, potassium hexametaphosphate, sodium polyphosphate, sodium pyrophosphate, and potassium pyrophosphate. Can be mentioned.

Specific examples of the organic acid include acetic acid, lactic acid,
Mention may be made of citric acid, malic acid, sorbic acid, ascorbic acid, hyaluronic acid, mugineic acid, humic acid and the like. Among them, citric acid is preferred in the present invention.

The content ratio of the acidic substance contained in the core material of the present invention is in the range of 0.01 to 5% by weight based on the weight of the core material. When the content ratio of the acidic substance is less than 0.01% by weight, the effect of the addition of the acidic substance is low and the correction of the pH may be insufficient. The swelling power of montmorillonite is the original swelling power of the montmorillonite to be used or is higher than that. However, when 3% by weight or more is added, the swelling power gradually decreases. Cannot be maintained. In the present invention, the content ratio of the acidic substance is 0.1 to 3
More preferably, it is in the range of% by weight.

Further, in addition to the above-mentioned components, known materials as granulation aids can be used in the core material of the present invention. As the granulation aid, mineral carrier, vegetable carrier, slaked lime,
Examples include urea-based fertilizers and plastic foams. Mineral carriers include clay, kaolin, sericite, talc, acid clay, pumice, quartz sand, quartzite, calcium carbonate, zeolite, perlite, vermiculite, etc., and plant carriers such as peach, sawdust, and wood powder. , Pulp floc, soy flour, corn stalk, starch, and the like. The urea-based fertilizer includes urea, acetaldehyde condensed urea, and isobutyraldehyde condensed urea.

In the present invention, the content of the above-mentioned granulating assistant is preferably in the range of 10 to 80% by weight based on the weight of the core material.

Further, a substance known as a binder can be used in the core material of the present invention. Examples of the binder include gum arabic, carboxymethyl cellulose, hydroxyethyl cellulose, lignin sulfonates, polyvinyl alcohol, polyethylene glycol, surfactants, and liquid paraffin.
In the present invention, it is preferable to use one having high water solubility.

Examples of the method for granulating the core material of the present invention include an extrusion granulation method, a coating granulation method, and an adsorption granulation method.
In the present invention, any of these granulation methods may be used, but the extrusion granulation method is the simplest.

Although the shape of the core material of the present invention is not particularly limited, it is preferably a shape close to a true sphere, and specifically, the circularity coefficient obtained by the following equation is 0.7 or more. Is preferred. It is more preferably at least 0.75, particularly preferably at least 0.8. Circularity coefficient =
(4π × projected area of particle) / (length of contour of particle projected view) ²
The maximum value of the circularity coefficient is 1, and as the circularity coefficient approaches 1, the shape of the core material approaches a perfect circle. When the core material is a perfect perfect circle, the circularity coefficient becomes 1. The circularity coefficient becomes smaller as the shape of the core material collapses from a perfect circle.

When the number of cores less than the lower limit of the circularity coefficient increases, the initial release becomes unstable in the case of coated pesticide granules. Is preferable, but a small amount may be present below the lower limit, as long as the effect of the present invention is not significantly impaired. The above circularity coefficient is determined by the piercing (PI
(AS) -IV (manufactured by Pierce Co., Ltd.).

When a coated pesticide granule using a core material having a circularity coefficient of 0.7 or more has a time-release type sustained release function described below, it is necessary to significantly suppress leakage of the pesticide during the release suppression period. It is particularly effective.

The particle size of the core material of the present invention is not particularly limited, and may be 0.3 mm or more, but is preferably in the range of 0.7 to 5.0 mm. 0.
If it is less than 3 mm, it is difficult to coat.

Examples of the resin used for the coated pesticide granules of the present invention include a thermoplastic resin and a thermosetting resin. Further, in the present invention, it is preferable to use a thermoplastic resin, and it is more preferable to use an olefin resin such as polyethylene and polypropylene.

The coating material used in the present invention may contain an auxiliary component in addition to the resin. The auxiliary component is preferably a fine powder of 0.1 to 100 μm, specifically, a fine powder of mineral substances such as talc and mica, a saccharide polymer powder such as starch, a metal complex such as sulfur, iron acetylacetone, and nickel dibutyldithiocarbamate. And the like. By adding the auxiliary component to the coating, the coated pesticide granules of the present invention
Functions such as improvement of the decomposability of the film after the release of the pesticidal active ingredient can be added.

The sustained release function of the coated pesticide granules of the present invention may be of a type in which release is started immediately after application,
It has a timed release type sustained release function consisting of a release suppression period in which the release of the pesticide active ingredient is suppressed for a certain period of time after application and a release period in which the rapid release of the pesticide active ingredient continues after a certain period of time. For example, labor-saving cultivation, for example, reducing the number of pesticide applications by applying at the same time as seeding, or applying it in the very vicinity of seeds, releasing a necessary amount after growing to some extent, and causing phytotoxicity such as germination disorders Not
It is also possible to improve the utilization efficiency of the pesticide components.

The time-release-type sustained release function referred to in the present invention specifically refers to a period from application to release of 10% by weight of the pesticidal active ingredient in the coated pesticide granules as a release suppression period, When the period from the release date of 10% by weight to the release date of 90% by weight is defined as the release period, it means a release pattern in which the ratio of release inhibition period / release period is 0.2 or more. It is in the range of 4 to 10, particularly preferably in the range of 0.5 to 5.

The timed release type sustained release function of the present invention may be based on any expression mechanism. Since pesticides are generally harder to dissolve in water than fertilizers, in order to release the pesticide components contained in the core material to the outside, JP-A-6-9 / 1994
No. 303, JP-A-6-9304, JP-A-6-9304
As disclosed in JP-A-72805, JP-A-6-80514, JP-A-9-77608, etc., the coating is broken down or dissolved and the pesticide granules inside the coating are removed from the environment (soil, water, etc.) outside the coating. , Etc.).

Among the above prior arts, Japanese Patent Laid-Open No. 6-9303
JP, JP-A-6-9304, JP-A-6-728
The coated pesticide granules disclosed in JP-A No. 05-2005 and JP-A-6-80514 are obtained by coating the surface of a granular simple substance containing an agricultural chemical component with a two-layer coating, but forming a two-layer coating. It is preferable that the number of coatings is one, in view of the complexity of the coating operation and the cost of capital investment for manufacturing equipment.

Examples of coated pesticide granules achieving a time-release type sustained release function with a single layer film are disclosed in, for example,
JP-A-77608 discloses a coated pesticide granule in which the surface of pesticide particles composed of at least one or more pesticide components and at least one or more water-swellable substances is coated with a coating mainly composed of a resin. be able to. After the coated pesticide granule of this composition is applied to a field or the like, the moisture supplied to the field acts on the water-swellable substance of the core material due to the moisture permeability of the film, and the pesticide particles start swelling. The coating collapses after a certain period of time due to the stress generated by the swelling of the water-swellable substance, and the pesticide particles inside the coating are directly exposed to the environment (soil, water, etc.) outside the coating.

The amount of the coating material is not particularly limited as long as the release can be controlled, but the proportion of the coating material is preferably 0.5 to 30 parts by weight with respect to 100 parts by weight of the core material. However, if the coating is too thick, the amount of the coating material increases, and the content of the agricultural chemical component decreases relatively, which increases the cost.

The method for producing the coated pesticide granules of the present invention is not particularly limited, but a film is formed by spraying a resin-containing coating material on the surface of a core material in a rolling or flowing state. It is preferable to use a production method that allows for
The coating material to be sprayed is preferably a dissolved or molten liquid. In consideration of ease of handling of the dissolved liquid and the molten liquid and ease of spraying in coating, the coating material is a liquid in which the coating material (resin) is dissolved in an organic solvent. Preferably, there is.

As a preferred example, a mixed solution obtained by dissolving a coating material containing a resin as a main component in an organic solvent is sprayed on a core in a jet state, and the solvent on the surface of the core is sprayed by a high-speed hot air flow. , And a method of coating the surface of the core material with a coating material.

An example of a coating apparatus that can be used in the production method will be described with reference to the accompanying drawings. Most preferably, the method for producing the product of the present invention is performed using the spouted bed shown in FIG. In the production method, in order to uniformly disperse the coating material according to the present invention, it is necessary to particularly strongly agitate the coating liquid. The spouted bed transports the mixed solution (coating solution) of the coating material to the rolling or flowing state of the pesticide particles 3 via the pipe 5, sprays the sprayed solution by the spray nozzle 2, and sprays the surface of the pesticide particles 3. At the same time as coating the surface, a high-temperature gas is caused to flow from the lower part of the jet tower 1 toward the guide tube 6, and the high-speed hot air flow causes
The solvent in the mixed solution adhering to the surface of the granules is instantaneously evaporated and dried.

[0051]

The present invention will be specifically described below with reference to examples. 1. Manufacture of core material (Examples 1 to 8, Comparative Examples 1 to 3) Bentonite (manufactured by Nippon Bentonite Industry, trade name: KA)
-1) 4200 g, clay (Takehara Chemical Industries, trade name: 5)
No. Clay) 1500 g, and N, N-diethyl-3-
Mesitylsulfonyl-1H-1,2,4-triazole-
A mixer (FKM300D,
(Manufactured by Redige Co., Ltd.) and mixed, and then 1200 ml of an aqueous solution was added to the acidic substance so as to have the amount shown in Table 1, and further mixed. The mixture was extruded and granulated with a screw extrusion granulator (TDG-110, manufactured by Fuji Paudal, screen diameter: 0.8 mmφ), and then rotated with a rotating disk-type granulator (QJ-400, manufactured by Fuji Paudal). The granulated product was spherically sized. Subsequently, fluid drying is performed (MDD-400
N, manufactured by Fuji Paudal Co., Ltd., hot air temperature: 100 ° C., 20 minutes) and sieved to obtain a core material having a particle size of 0.8 to 1.4 mmφ.

2. Evaluation of physical properties of core material (Swelling force test) The core materials (Examples 1 to 8 and Comparative Examples 1 to 3) obtained by “1. Production of core material” were pulverized, and 2 g each was quietly placed in 100 ml pure water. In addition to the above, the volume of the sample after 24 hours was read and defined as the swelling force. The results are shown in Table 1.

(Measurement of Shape) The circularity coefficient of the core material was measured using Pierce (PIAS) -IV manufactured by Pierce Co., Ltd. The measurement was performed using 100 particles (core material) taken out at random. The circularity coefficient was based on the following equation. The results are shown in Table 1. Circularity coefficient = (4π × projected area of particle) / (length of contour of particle projected view) ²

(PH measurement) The core material was pulverized, and 4 g
Each was placed in 200 ml of pure water and stirred to form a uniform dispersion, and immediately measured with a pH meter. The results are shown in Table 1.

[0055]

[Table 1] * 1 Phosphoric acid: Wako Pure Chemical, special grade reagent * 2 Hydrochloric acid: Wako Pure Chemical, special grade reagent * 3 Hydrochloric acid: Wako Pure Chemical, special grade reagent * 4 Sodium dihydrogen phosphate: Wako Pure Chemical, special grade reagent * 5 Sodium dihydrogen phosphate: made by Wako Pure Chemical, special grade reagent

As is clear from Table 1, the core materials of Examples 1 to 8 exhibited a sufficient swelling force to disintegrate the coating. Among them, phosphoric acid showed a swelling power higher than that of Comparative Example 3 with no electrolyte added, as is clear from Examples 1 to 3. Further, 2.
About 0% by weight, the swelling power was about twice as high. Further, the sodium dihydrogen phosphate of Example 6 also exhibited a swelling power higher than that of Comparative Example 3, and Example 7 in which phosphoric acid and sodium dihydrogen phosphate were added in combination also maintained the swelling power. Further, in Example 8 in which citric acid was added in addition to phosphoric acid and phosphate, the swelling power was maintained. In Comparative Examples 1 and 2, no swelling was observed. Each of the circularity coefficients was 0.8 or more, which was a good shape.

3. Production of coated pesticide granules (Examples 9-1)
6, Comparative Examples 4 to 6) The core materials of Examples 1 to 8 and Comparative Examples 1 to 3 were applied to the coating material using the jet coating apparatus (tower diameter 250 mm, height 3000 mm) shown in FIG. , Low density polyethylene (MF
R 6.6 to 7.4 g / 10 min) 15% by weight, ferric acetylacetone 0.5% by weight, talc (average particle size 5 μm)
m) Coating materials each having a composition of 84.5% by weight were coated until the coating ratio became 20% by weight with respect to the coated pesticide granules, thereby obtaining each of the coated pesticide granules of the present invention (implementation) Examples 9 to 16 and Comparative Examples 4 to 6). The manufacturing conditions are as follows. The coverage is the ratio of the weight (b) of the coating to the coated pesticide granules, with the sum of the weight (a) of the pesticide particles (a) and the weight (b) of the coating being 100%, and is calculated by the formula [b × 100 / (a)
+ b)]. For coating, the above-mentioned coating material was dissolved in tetrachloroethylene, and a 2.5% uniform coating material solution was used. One-fluid nozzle: 0.4 mm full cone type core Material: 3 kg Hot air temperature: 105 ± 2 ° C Hot air volume: 4 m ³ / min Spray flow rate: 0.27 kg / min

4. Evaluation of sustained release function of coated pesticide granules (water release test) A coated pesticide granule obtained in “3. Production of coated pesticide granules” was subjected to a water release test. Test tube with cap (12
1.5 mL of water (not degassed) was placed in a sample tube (mm × 72 mm). Using 100 tubes (particles) per test plot, the number of collapses of the coated pesticide granules was counted at a constant water temperature of 20 ° C., considering the collapse of the coating as release. Observations were made daily for 50 days from the start of the test.
Observed for days. The cumulative release rate is the number of disintegrations of the test granules. The release inhibition period is defined as the cumulative release rate reaches 10%, and the release period is defined as the cumulative release rate reaches 10 to 90%. The results are shown in Table 2. .

[0059]

[Table 2]

In Examples 9 to 16, the time-release type, which comprises a release suppression period in which the release of the pesticide active ingredient is suppressed for a certain period of time and a release period in which the release of the pesticide active ingredient continues after the release suppression period has elapsed. It had a sustained release function. On the other hand, when the non-swelled core materials of Comparative Examples 1 and 2 were used, no release was confirmed even after 50 days had elapsed.

[0061]

According to the present invention, the content of the acidic substance in the coated pesticide particle for montmorillonite, the acidic substance and the pesticide component is
When the amount is within the range of 0.01 to 5% by weight based on the pesticide particles, the pH of the pesticide particles can be corrected without impairing the original swelling power of montmorillonite, and the pesticide particles for the coated pesticide granules can be used. If a coated pesticide granule coated with a coating material is used, even a pesticide which is originally alkaline and unstable can exhibit stable efficacy.

[Brief description of the drawings]

FIG. 1 is a sectional view of a spouted bed coating apparatus.

[Explanation of symbols]

 Spout tower Spray nozzle Core material Hot air supply pipe Coating material introduction pipe Guide pipe

Claims (7)

[Claims] 1. A pesticide particle for a coating pesticide granule comprising montmorillonite, an acidic substance, and an agricultural chemical component, wherein the content of the acidic substance is in the range of 0.01 to 5% by weight based on the pesticide particle. A pesticide particle for a coated pesticide granule. 2. The pesticide particles for coated pesticide granules according to claim 1, wherein the acidic substance is at least one selected from the group consisting of phosphoric acid and phosphate. 3. The pesticide particles for coated pesticide granules according to claim 1, wherein the acidic substance is citric acid. 4. The pesticide particles for coated pesticide granules according to any one of claims 1 to 3, wherein the circularity coefficient determined by the following equation is 0.7 or more. Circularity coefficient = (4π × projected area of particle) / (length of contour of particle projected view) ² 5. A coated pesticide granule obtained by coating the surface of the coated pesticide particles for agrochemicals according to claim 1 with a coating material containing a resin. 6. The resin according to claim 5, wherein the resin is an olefin polymer.
4. The coated pesticide granule according to item 1. 7. A timed release of a coated pesticide granule comprising a release suppression period in which the release of a pesticide active ingredient is suppressed for a certain period after application, and a release period in which the release of the pesticide active ingredient continues after the release suppression period has elapsed. The coated pesticide granule according to claim 5 or 6, which has a sustained release function.