JPS644483B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to granular agricultural chemicals, and more particularly to sustained-release granular agricultural chemicals. [Prior Art] In recent years, many attempts have been made to achieve sustained release of active ingredients for the purpose of saving labor in agriculture, preventing chemical damage, and preventing environmental pollution caused by agricultural chemicals. There are various manufacturing techniques for sustained-release pesticides that have been proposed in the past, but they can be roughly divided into: (1) mixing a room-temperature-reactive curing resin and the pesticide together to achieve sustained release (Japanese Patent Application Laid-open No. 48-5940), (2) Microcapsule the pesticide (see Japanese Patent Application Laid-Open No. 48-4643), (3) Sprinkle synthetic resin on granular pesticides and then add fine powder to prevent them from forming blocks. Dressing in powder (Special Publications 1977-
19080), (4) containing a new oil base that is solid at room temperature (see JP-A-55-4356), (5) supporting an active ingredient on an adsorbent (JP-A-56-4356). 156201
(Refer to the Publication No.) and so on. However, all of these sustained-release pesticides have many drawbacks. In other words, in either case, the effect of sustained release is insufficient, and the objectives of sustained release, such as prolonging residual efficacy, preventing environmental pollution, and reducing drug damage, cannot be fully achieved. It requires a large amount of additives (synthetic resin, lipophilic base, adsorbent, etc.), and is not necessarily practical from an industrial or economic standpoint. For example, synthetic resins like (1) and (3), or (4)
When a solid lipophilic base is used, a considerably large amount of resin or lipophilic base is required to completely control elution, and even if elution can be suppressed by using a large amount, elution may still occur. It is extremely difficult to adjust freely. Furthermore, if the uniformity of the additives is lacking on the surface of the powdered pesticide treated with these, pinholes will occur, which will disrupt the balance of elution control and have low industrial utility value. (2)
However, in order to microcapsule it, a large amount of equipment, manufacturing process, etc. is required, and it lacks practicality. Regarding (5), in order to adsorb the active ingredient, a large amount of adsorbent is required, or an adsorbent with high adsorption power is required. But in this case,
As a result of strongly adsorbing the ingredients, it is often impossible to completely release the active ingredients in water, which is uneconomical. In view of the above-mentioned current situation, the present inventors have conducted extensive research into developing a formulation technology that is both industrially and economically practical and has sufficient sustained release properties, and as a result, they have completed the present invention. Ivy. [Object of the Invention] An object of the present invention is to provide a new sustained-release granular pesticide that solves the drawbacks of the prior art described above. [Structure of the Invention] To summarize the present invention, the sustained-release granular pesticide of the present invention is characterized in that a powder composition containing an active ingredient for pesticides and a carrier is provided with a coating layer consisting of an isocyanate compound and liquid paraffin. do. Further, the sustained-release granular pesticide of the present invention comprises a granular composition containing an agriculturally active ingredient and a carrier, provided with a coating layer made of an isocyanate compound and liquid paraffin, and further provided with a coating layer of organic powder and/or inorganic powder as an outer layer. It is characterized by having been established. In the present invention, the powder composition containing an agricultural chemical active ingredient and a carrier is provided with the coating layer to control the release of the active ingredient from the carrier in the granular composition, and the outer layer of the coating layer is It has been found that this can be promoted by providing a coating layer of organic powder and/or inorganic powder. Although it is difficult to theoretically explain the effects of the isocyanate compound and liquid paraffin in the coating layer, it has been experimentally confirmed that the effects of the present invention can only be achieved by using both in combination. Next, the isocyanate compound used in the present invention,
Liquid paraffin, organic powder or inorganic powder, and active ingredients for agricultural chemicals will be explained. In the present invention, as the isocyanate compound,
Although any isocyanate compound can be used, isocyanate compounds having a large number of isocyanate groups are particularly effective. As illustrated below, these compounds may be used alone or in a mixture of two or more. Aliphatic diisocyanates such as hexamethylene diisocyanate; m-phenylene diisocyanate, p-phenylene diisocyanate, tolylene-2,6-diisocyanate, tolylene-
2,4-diisocyanate, diphenylmethane
4,4'-diisocyanate, chlorphenylene-
2,4'-diisocyanate, naphthalene-1,5
-diisocyanate, diphenyl-4,4'-diisocyanate, 4,4'-diisocyanato-3,
Aromatic diisocyanates such as 3'-dimethyl-diphenyl, 3-methyl-diphenylmethane-4,4'-diisocyanate and diphenyl ether diisocyanate; 1-methylcyclohexyl-2,4-diisocyanate, 1-methylcyclohexyl-2,6 - diisocyanates, bis(isocyanatocyclohexyl)-cycloaliphatic diisocyanates such as methane; triisocyanates such as 2,4,6-triisocyanatotoluene, 2,4,4'-triisocyanatodiphenyl ether; general formula (wherein n is an integer of 0 or 1 or more) A methylene-crosslinked polyphenylene polyisocyanate produced by phosgenating a corresponding mixture of polyamines obtained by condensation of aniline and formaldehyde. The isocyanate compound in the present invention is not limited to the above compounds, but is preferably a crude mixture of methylene-crosslinked polyphenylene polyisocyanates containing aromatic isocyanates, especially diisocyanates, triisocyanates and highly functional polyisocyanates. The liquid paraffin used in the present invention is a saturated hydrocarbon obtained from petroleum that is liquid at room temperature, and is generally commercially available as a mixture having 20 or less carbon atoms. Examples of organic powders or inorganic powders used in the present invention include fine mineral powders such as clay, talc, diatomaceous earth, and bentonite, salts such as calcium carbonate, magnesium carbonate, and sodium chloride, white carbons, natural polymers such as starch, and cellulose, and polyvinyl Examples include fine powders of synthetic or semi-synthetic polymers such as alcohol and carboxymethylcellulose, particularly fine powders of 100 mesh or less, and even if they are water-soluble, they may be in powder form at the time of preparation. The active ingredient for agricultural chemicals in the present invention is not particularly limited, but a typical example is 5-methyl-
1,2,4-triazolo(3,4-b)-benzothiazole (tricyclazole), 1,2,5,
6-tetrahydro-4H-pyrrolo[3,2,1-
ij] Quinolin-4-one (pyroquilon), diisopropyl-1,3-dithiolan-2-ylidene-
Malonate (isoprothiolane), 3-allyloxy-1,2-benziisothiazole-1,1-
Dioxide (probenazole), 2,3-dihydro-2,2-dimethylbenzofuran-7-yl-
N-methyl carbamate (carbofuran), 2,
3-dihydro-2,2-dimethylbenzofuran-
7-yl(dibutylaminothio)-N-methylcarbamate (carbosulfan), 2,2-dimethyl-1,3-benzodioxol-4-yl-N
-Methyl carbamate (bendiocarb), O,
O-3,5,6-trichloro-2-pyridyl-
O,O-dimethylphosphorothioate (chlorpyrifosmethyl), 2-chloro-1-(2,4-dichlorophenyl)vinyldimethylphosphate (dimethylvinphos), O,O-dimethyl-O-[3-
Methyl-4-(methylthio)phenyl]thiophosphate (MPP), 1,3-bis(carbamoylthio)-2-(N,N-dimethylamino)propane hydrochloride (Cartap), 2,4-bis(ethylamino) -6-methylthio-1,3,5-triazine (dimethrine), S-ethylhexahydro-1H
-Azepine-1-carbothioate (molinate), 2-chloro-2',6'-diethyl-N-(butoxymethyl)acetanilide (butachlor),
2-(β-naphthyloxy)propionanido (naproanilide), 4-(2,4-dichlorobenzoyl)-1,3-dimethyl-5-pyrazoyl-
p-Toluenesulfonate (pyrazolate), S
-p-chlorobenzyldiethylthiocarbamate (benthiocarb) is mentioned, and the active ingredient may be used alone or in combination of two or more kinds. As the carrier to be mixed with the active ingredient, external adsorption carriers such as mineral fine powder, such as clay, talc, diatomaceous earth, and bentonite, which are used as carriers for general granular agricultural chemicals, are used. The blending ratio of the active ingredient and the carrier is not particularly limited, but is determined by the amount of the active ingredient used as the sustained-release granular pesticide. The amount of active ingredient is from 0.05 to 30% by weight, preferably from 0.1 to 20% by weight, based on the weight of the sustained release granular pesticide. The ratio of isocyanate compound to liquid paraffin forming the coating layer is 1:10 to 10:1, preferably 1:5 to 5:1. The amounts of the isocyanate compound and liquid paraffin used are each 1.0 to 20.0% by weight, preferably 2.0 to 10.0% by weight, based on the weight of the sustained-release granular pesticide. The amount of organic powder or inorganic powder used as the outer layer is
The amount is 3.0 to 30.0% by weight, preferably 5.0 to 20.0% by weight. The amount of each of the above-mentioned materials used is 1
It does not mean the exact composition ratio of the grains, but the ratio of each material used during its preparation. The amount and proportion of each used can be adjusted depending on the desired degree of sustained release of the agrochemical active ingredient, thereby making it possible to freely control the dissolution of the active ingredient. In addition to the above-mentioned components, the sustained-release granular pesticide of the present invention contains a powder composition and an outer layer containing a physical property improver, a stabilizer,
Auxiliary agents such as colorants and surfactants may be added, and agricultural active ingredients that do not require sustained release properties may be added to the outer layer. The following method can be adopted as a method for producing the sustained-release granular pesticide of the present invention. First, the following three methods can be used to obtain a granular composition containing an agricultural chemical active ingredient and a carrier, but the method is not limited thereto. (1) Mixing active ingredients for pesticides, binders, and carrier fine powder,
After pulverization, a granular composition is obtained by kneading and granulation. (2) A granular composition is obtained by adsorbing a liquid pesticide or a solution of a solid pesticide in a nonvolatile solvent onto an oil-absorbing granular carrier or a granular carrier obtained by kneading and granulation. (3) There is a method in which a granular carrier or a granular carrier obtained by kneading and granulation is coated with an agrochemical active ingredient via a binder to obtain a granular composition. The isocyanate compound and liquid paraffin are added separately to the granular composition containing the active ingredient obtained by these methods, or the two are mixed and added simultaneously to coat the composition. Furthermore,
Coat with organic or inorganic powder. By uniformly coating these, the sustained-release granular pesticide of the present invention can be obtained. [Examples of the invention] The present invention will be described with reference to examples, reference examples, and test examples.
I will explain in more detail. All "parts" or "%" in the following examples and reference examples indicate "parts by weight" or "% by weight." Example 1 45 parts of tricyclazole and polyvinyl alcohol
After adding 30 parts and 925 parts of clay and mixing, add an appropriate amount of water and knead. Add this to the granulator with a hole diameter of 0.8
Granulate with a mm screen. After drying this granulator, the particles are sized to obtain a tricyclazole kneading base. Next, 900 parts of this tricyclazole kneading base was coated with 50 parts of a mixture of tolylene-2,4- and -2,6-diisocyanate (ratio 8:2), and then 50 parts of liquid paraffin was evenly coated. Granules containing 4% tricyclazole are obtained. Example 2 50 parts of tricyclazole and polyvinyl alcohol
30 parts and 920 parts of clay were added to obtain a tricyclazole kneading base according to the method of Example 1. Next, take 800 parts of this tricyclazole kneading base, add 50 parts of the following crude mixture of methylene-crosslinked polyphenylene polyisocyanate and liquid paraffin.
After adding 50 parts at the same time to uniformly coat, add 100 parts of diatomaceous earth as an outer layer and uniformly coat to obtain granules containing 4% tricyclazole. Methylene crosslinked polyphenylene polyisocyanate (The methylene group is attached at the O-, m-, and p-position relative to the isocyanato group) Example 3 Take 775 parts of granular calcium carbonate of 16 mesh and 32 mesh, and add 50 parts of pyroquilon to polyethylene glycol (molecular weight approximately 400). Mixed using 25 parts,
A granular composition containing pyroquilone is obtained. Next, 30 parts of 2,4,6-triisocyanate toluene is added and after coating, 30 parts of liquid paraffin is added and uniformly coated. In addition, talc 90 is added as an outer layer.
to obtain granules containing 5% of pyroquilone. Example 4 20 parts of polyvinyl alcohol, 100 parts of bentonite, and 806.5 parts of clay were added to 73.5 parts of carbosulfan to obtain a kneading base containing carbosulfan according to the method of Example 1. Next, 680 parts of this carbosulfan kneading base was coated with 60 parts of liquid paraffin, and diphenyl-
60 parts of 4,4'-diisocyanate are uniformly coated. Furthermore, 200 parts of clay is evenly coated as an outer layer.
Granules containing 5% carbosulfan are obtained. Example 5 Tricyclazole kneading base obtained in Example 1
Take 900 parts and add the diphenyl used in Example 4.
40 parts of a mixture (1:1) of 4,4'-diisocyanate and liquid paraffin are coated. Next, after uniformly coating 10 parts of white carbon, 50 parts of propafos (O,O-dipropyl-O-methylthiophenyl phosphate) is adsorbed to obtain a powder containing 4% tricyclazole and 5% propafos. Example 6 55 parts of tricyclazole, 68 parts of carbosulfan, 10 parts of sodium carboxymethyl cellulose,
300 parts of bentonite and 567 parts of talc were added to obtain a tricyclazole and carbosulfan kneading base according to the method of Example 1. Next, 730 parts of this kneading base was taken, and Example 2
80 parts of the crude mixture of methylene-crosslinked polyphenylene polyisocyanate used in and 40 parts of liquid paraffin
were added at the same time and coated. Furthermore, calcium carbonate
150 parts are coated to obtain granules containing 4% tricyclazole and 5% carbosulfan. Example 7 91 parts of molinate and 10 parts of polyvinyl alcohol,
200 parts of bentonite and 699 parts of clay were added to obtain a molinate kneading base according to the method of Example 1. Take 880 parts of a molinate kneading base and add a mixed solution of 100 parts of liquid paraffin and 20 parts of tetramethylene pentaphenyl pentaisocyanate with stirring to uniformly coat the mixture to obtain granules containing 8% of molinate. Example 8 100 parts of diatomaceous earth, 300 parts of bentonite, and 600 parts of calcium carbonate are mixed, and a granular empty base material containing no active ingredient is obtained according to the granulation method of Example 1. 760 parts of this blank base material was taken, 40 parts of butachlor was adsorbed thereon, and then 70 parts of liquid paraffin was coated, then 30 parts of diphenyl-4,4-diisocyanate was coated, and then 100 parts of powdered starch was evenly coated. Granules containing 4% butachlor are obtained. Example 9 840 parts of the empty base of Example 8 was taken, and 15 parts of dimethrine was added.
A solution prepared by dissolving 1 part in 70 parts of Benthiocarb is adsorbed. These are coated with 45 parts of liquid paraffin. Next, 30 parts of tetramethylene pentaphenyl pentaisocyanate was evenly coated, and simetrine
Granules containing 1.5% and 7% penthiocarb are obtained. Reference Example 1 After mixing 40 parts of tricyclazole and 600 parts of clay, this mixture was mixed with solid paraffin with a melting point of 58°C.
Gradually add and mix into a heated molten mixture of 210 parts and 150 parts of stearic acid (melting point 58-59°C). After heating these mixtures to approximately 80°C to form a suspension, they were spray-granulated using a spray-type granulator to obtain tricyclazole 4.
Granules containing %. Reference Example 2 900 parts of the tricyclazole kneading base (containing 4.5% of tricyclazole) obtained in Example 1 was taken, and 100 parts of a mixture of tolylene-2,4- and 2,6-diisocyanate was uniformly coated, and 4% of tricyclazole was added. Obtain granules containing: Reference Example 3 40 parts of tricyclazole are mixed with 300 parts of activated carbon, 30 parts of polyvinyl alcohol, and 630 parts of clay, and granulated and dried according to the granulation method of Example 1 to obtain granules containing 4% tricyclazole. Reference Example 4 Take 850 parts of the granular composition containing 5.9% pyroquilone obtained in Example 3, coat it with 60 parts of liquid paraffin, and then uniformly coat it with 90 parts of talc to obtain a granule containing 5% pyroquilone. . Reference Example 5 Carbosulfan kneading base 680 obtained in Example 4
A mixture of 240 parts of diphenyl-4,4'-diisocyanate and 20 parts of the acrylic polyol described below was added thereto to uniformly coat the mixture to obtain granules containing 5% of carbosulfan. Acrylic polyol general formula The compound represented by and the general formula Polymer of the compound shown (average molecular weight 2000~
4600) Reference Example 6 Tricyclazole kneading base obtained in Example 1
Take 900 parts liquid paraffin 50 parts and propaphos 50 parts
A mixed solution of 5% is added, adsorbed and coated to obtain granules containing 4% tricyclazole and 5% propafos. Reference Example 7 730 parts of the tricyclazole and carbosulfan kneading base obtained in Example 6 were taken and coated with 120 parts of the crude mixture of methylene crosslinked polyphenylene polyisocyanate used in Example 2, and further 150 parts of calcium carbonate was added. are uniformly coated to obtain granules containing 4% tricyclazole and 5% carbosulfan. Reference Example 8 Take 880 parts of the molinate kneading base obtained in Example 7, add 30 parts of liquid paraffin, 60 parts of an epoxy compound (GAN: manufactured by Nippon Kayaku Co., Ltd.), and a polyamide compound (React CA-101: Sanyo Chemical). Co., Ltd.) to obtain uniformly coated granules containing 8% molinate. Reference Example 9 Take 760 parts of the empty base obtained in Example 8, add 40 parts of butachlor, and add epoxy compound (GOT: Nippon Kayaku Co., Ltd.).
Co., Ltd.) 70 parts, polyamide curing agent (React CA
-101: Add a solution containing 30 parts of the above) and let it adsorb onto the empty base. After uniform adsorption, powder starch
100 parts are coated to obtain granules containing 4% butachlor. Reference Example 10 Take 915 parts of the blank base obtained in Example 8, dissolve 15 parts of cymetrine in 70 parts of penthiocarb, and adsorb the solution to the base to obtain granules containing 1.5% cymetrine and 7% of benchcarb. . The following tests were conducted on the granules prepared in Examples 1 to 9 and Reference Examples 1 to 10 described above. Test Example 1 Dissolution Test in Water The dissolution properties of the components of each granule prepared in accordance with Examples and Reference Examples in water were tested. The test method is as follows. Prepare 3 beakers and fill them with 3 degree hard water 900
ml and leave it in a constant temperature room at 20℃ for 1 day. Spread 90 mg of granules whose component values have been measured in advance evenly into the beaker. 1, 10, 30, 60, and 100 days after spraying, water was sampled from the center of the beaker (1 cm deep), and each component was quantified using gas chromatography or high performance liquid chromatography. Elution rate is the amount of each component eluted in water (μg)
and the amount of each component contained in the sprayed granules (μg)
It was calculated from the following formula. The results are shown in Table 1. Dissolution rate in water (%) = Amount of component eluted in water (μg) / Amount of component contained in the dispersed granules (μg) x 100 The quantitative method for each component is carbosulfan, propafos, molinate, butachlor, penthiocarb, Cymetrine was analyzed by gas chromatography, and tricyclazole and pyroquilone were analyzed by high performance liquid chromatography.

【table】

[Table] Test Example 2 Blast control test Examples 1, 2, 3, 5, 6 and Reference Examples 1, 2,
Granules Nos. 3, 4, 6, and 7 were used to observe blast control effects and chemical damage. The test method is shown below. Seedling raising Rice seedlings at the 2.5 leaf stage (variety: Aichi Asahi) grown in a seedling raising box (30 x 60 x 3 cm) were tested. Chemical treatment The day before transplantation, 100 g of each test granule was mixed per seedling box, and after treatment, 500 ml of water per box was applied. Cultivation of rice One day after chemical treatment, cut the rice with a rice transplanter and
5 stems each in a container (TS-36, 54×
Four plants were planted in an area (36 x 15 cm). In addition, the planting density of 4 plants per container is approximately 20,000 plants/10a planted in the field.
corresponds to Testing the effect of controlling rice blast disease: Transfer the container to a greenhouse bed where blast disease is prevalent and naturally infect it. 10 days after transplantation (chemical damage), 55 days after transplantation (leaf blast disease), and 100 days after transplantation. An investigation was conducted on the eyes (ear blast disease) to examine the control effect and chemical damage. However, the investigation of leaf blast was carried out based on the lesion area ratio per plant according to the day plant prevention prevention survey standards. Regarding the panicle blast disease, the morbidity (%) was calculated using the following formula. Disease severity (%) = (Number of panicles affected by node/neck blast disease) × 4 + (Number of panicles affected by 2/3 or more of the branches) / (Total number of investigated panicles) × 4 × 3 + (1/3 to 2/3 of the branches) 3 Number of affected panicles × 2 + (number of affected panicles of 1/3 or less of the stems) / × 100 In addition, the evaluation of chemical damage was performed according to the following criteria: −: Healthy leaves (no chemical damage) +: Approximately 20 to 30 of the leaves Phytotoxicity is observed in approximately 30% of the leaves. The results are shown in Table 2.

[Table] Test Example 3 Insecticidal power residual effect test (residual effect test using rice weevil larvae) Using the granules of Examples 4 and 6 and Reference Examples 5 and 7,
An insecticidal residual effect test against rice weevil larvae was conducted. The test method is shown below. Seedling raising and chemical treatment were carried out according to the method of Test Example 2. One day after the chemical treatment, each plant with 5 stems was transplanted into a Wagner pot with an area of 1/5000. After transplanting, the pots were stored in a covered field with a water depth of 3 cm. For inoculation of larvae, adult larvae were used to lay eggs in a container in a greenhouse and reared while supplementing with rice. Ten animals of each type were released per pot. The investigation was conducted by washing the rice roots with water one week after inoculating the larvae and checking the number of larvae. The results are shown in Table 3.

【table】

[Table] For example, the data on the 20th day in the table indicates that larvae were inoculated on the 20th day after the drug treatment, and the number of larvae was examined one week later. Test Example 4 Herbicidal Effect Test A herbicidal effect test was conducted using the granules of Examples 7, 8, 9 and Reference Examples 8, 9, and 10. The test method is shown below. After using Wagner pots with a size of 1/5000 are to prepare the pots for puddling, each pot was sown with 30 grains of Japanese millet and a mixture of seeds of azalea, azalea, and Japanese japonica, and covered with 5 mm of soil. On the 8th day after weed sowing, an equivalent amount of 3 kg/10 a of the test granules was removed, and 10
The remaining amounts of Japanese millet, Japanese azalea, Kikashigusa, and Konagi after 1, 20, 30, and 40 days were investigated. The water depth at the time of chemical treatment was approximately 3 cm, and after that, the water depth was maintained at 3 cm by irrigation. The results are shown in Table 4.

【table】

〔Effect of the invention〕

As is clear from the above explanation, by using an isocyanate compound and liquid paraffin together as a coating layer, the sustained-release granular pesticide of the present invention complements each other's coating unevenness, compared to when they are used alone. This not only prevents coating non-uniformity and pinhole formation, but also makes it possible to obtain a remarkable sustained release effect with a small amount of use. Furthermore, by using an organic powder or an inorganic powder in combination, the sustained release effect can only be further improved by eliminating the small amount of pinholes that still exist even when the two types of compounds mentioned above are used together, due to the filling effect of the powder. It is possible to reduce the amount of each used. Furthermore, according to the present invention, the sustained release effect can be freely controlled by adjusting the amount of additives used, and furthermore, biological effects (extension of residual effects, avoidance of drug damage), which were not possible with conventional techniques, can be achieved. Sufficient sustained release properties can be obtained. On the other hand, after coating the isocyanate compound and liquid paraffin, by using oil-absorbing fine powder such as white carbon, diatomaceous earth, etc. as a powder, and by adsorbing other agricultural active ingredients or coating with a binder,
Granular pesticides are obtained which carry active ingredients in a multilayered structure, and it is also possible to release several active ingredients at different rates. Further, the additives used in the present invention can achieve sufficient effects with a relatively small amount, and no special steps are required in the manufacturing process, so that they are practical from an economical and industrial standpoint. As described above, the sustained-release granular pesticide of the present invention has several excellent features not available in conventional sustained-release preparations, which will be summarized and listed below. 1. Since the sustained-release granular pesticide according to the present invention can freely control the release of active ingredients, the duration of drug efficacy is significantly extended. As a result, it is now possible to reduce the number of times of spraying, compared to the conventional method of spraying in multiple times. In addition, especially in seedling boxes, which is a growing form of paddy rice that has been frequently used in recent years, the chemicals that should normally be sprayed on the rice fields after rice planting are concentrated at a high density during the seedling growing stage (because the area is small, it is very easy to spray). It can be sprayed, etc., which has a large labor-saving effect. 2. On the other hand, even if the active ingredient has a harmful effect (phytotoxicity) on the plant body if it is eluted at a high concentration at once, it is possible to keep the concentration to a low enough range to obtain medicinal efficacy, and it is possible to keep it in a single spraying treatment. can be avoided while maintaining drug efficacy for a longer period of time. Furthermore, since a high concentration of the drug does not elute at once, it has the advantage of being safer for seafood and wildlife.

Claims (1)

[Scope of Claims] 1. A sustained-release granular agricultural chemical, characterized in that a granular composition containing an agricultural chemical active ingredient and a carrier is provided with a coating layer comprising an isocyanate compound and liquid paraffin. 2. A sustained-release granular pesticide, characterized in that a granular composition containing an active ingredient for pesticides and a carrier is provided with a coating layer consisting of an isocyanate compound and liquid paraffin, and a coating layer of organic powder and/or inorganic powder as an outer layer.