Controlled-release granules for aerial pest control and preparation method thereof

Abstract

The present invention relates to A01N, and more specifically, to a controlled-release granule for aerial pest control and a preparation method thereof. The raw materials for preparing the granule include: an active ingredient, an oily liquid, a water-soluble coating material, and a carrier. The granule of the present invention is suitable for aerial pest control operations. It is more convenient and more efficient to use a drone to spread it in beaches, ditches, etc. The outer layer of the prepared granule is coated with a film-forming agent, which has good strength. There is no dust during the drone aerial pest control operation and no waste of the medicine. The granule of the present invention is coated with a moisture-sensitive film-forming material. Only when there is water, moisture or high humidity in the target area will the film-forming material dissolve and the medicine liquid will be released, achieving the effect of controlled release and increasing the scope of action of the medicine. The medicine liquid adsorbed by the granule carrier of the present invention is an oily medicine liquid. When it comes into contact with water, it will spread along the water-wetting surface, thereby increasing the scope of action of the medicine.

Description

Technical Field

[0001] The present invention relates to A01N, and more particularly to a controlled-release granule for aerial pest control and a preparation method thereof. Background Art

[0002] Using granules containing active ingredients that kill pests or pathogens is one way to prevent threats such as crop diseases or insect pests. Currently, granules are mainly applied manually using backpack sprayers or spreaders. These methods have problems such as low labor efficiency, bulky equipment, and low average spread rate and spread area. In addition, for some disease or insect pest distribution areas, such as snail distribution areas on river and lake beach beaches and ditches, canals, ponds, and field ridges without water accumulation, the existing manual backpack spraying method of granules is very inconvenient and time-consuming. Therefore, it is necessary to provide a granule that can be used for aerial spraying operations, that is, using drones for pest control to improve efficiency.

[0003] Currently, granules are often prepared by coating a drug powder with a carrier, such as fine sand, and a binder. For example, CN103766332A provides a novel, environmentally friendly, snail-killing granule for spraying and its preparation method. The granule comprises an active ingredient for killing snails, a composite binder, and fine sand as a carrier. The granule provides a sand-based formulation with moderate quality, minimal impact on production and application equipment, and long-term sustained release. However, there are issues with the drug powder's insufficient bonding strength, resulting in high dust levels during drone spraying operations, polluting the environment and wasting the drug. Furthermore, the spraying process suffers from poor fluidity, resulting in clogged materials and uneven application.

[0004] In addition, the existing granules release the drug directly after reaching the target, which wastes the drug. At the same time, the effective range of a single particle of the traditional granules is very small, and a large number of granules are needed to cover the application area, which also causes excessive use of the drug. Summary of the Invention

[0005] In order to solve the above problems, the first aspect of the present invention provides a controlled-release granule for aerial pest control. The raw materials for preparing the granule include, by weight, 5 to 40 parts of active ingredients, 5 to 30 parts of oily liquid, 0.5 to 5 parts of water-soluble coating material, and the carrier is supplemented to 100 parts.

[0006] The present invention does not make any specific limitation on the active ingredients, and can be an active ingredient for preventing and controlling pests and diseases, such as blood-preventing snails, preventing and controlling insect pests such as spider mites, striped stem borers, planthoppers, aphids, and rice seedling pathogens, leaf fall disease, leaf spot disease, rice blast disease, etc., without specific limitation.

[0007] When the granules are used for snail control, the active ingredients include, but are not limited to, sodium pentachlorophenate, niclosamide ethanolamine salt, niclosamide, metaldehyde, calcium cyanamide, chloroacetamide, nicotinamide, and the like.

[0008] The present invention does not specifically limit the type of carrier, and the carrier is well known in the art, and can be exemplified by one or more of attapulgite, ceramsite sand, kaolin, clay, white carbon black, and diatomaceous earth.

[0009] In order to improve the adsorption performance of the carrier, the carrier can be activated, such as acid activation or heat activation of the attapulgite. When acid activation is performed, it can be activated by hydrochloric acid, sulfuric acid, etc. When heat activation is performed, it can be heated at 200-300°C, without specific limitation.

[0010] In order to improve the fluidity of the granules and reduce dust pollution during the flying spraying process of the granules, the shape of the carrier is spherical or quasi-spherical, and the particle size of the carrier is in the range of 1 to 3 mm. The particle size range of the carrier is 1 to 3 mm, which means that the particle size of the carrier is distributed between 1 and 3 mm (including 1 mm and 3 mm).

[0011] As a preferred technical solution of the present invention, the oily liquid is selected from one or more of ester liquids, mineral oils, vegetable oils, and esterified vegetable oils.

[0012] As a preferred technical solution of the present invention, the ester liquid is selected from one or more of methyl oleate, ethyl acetate, butyl oleate, ethyl laurate, methyl laurate, butyl laurate, methyl palmitate, ethyl palmitate, butyl palmitate, and esterified vegetable oil. Preferably, the ester liquid is a chain ester liquid, and the number of carbon atoms in the ester liquid is 10 to 25, and examples thereof include 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, and 25.

[0013] As a preferred technical solution of the present invention, the esterified vegetable oil is an ester substance obtained by reacting vegetable oil with alcohol. According to the type of alcohol in the reaction, it can be divided into methylated vegetable oil, butylated vegetable oil, octylated vegetable oil, etc., and examples include methylated soybean oil, methylated coconut oil, etc., without specific limitation.

[0014] As a preferred technical solution of the present invention, the vegetable oil is selected from one or more of corn oil, rapeseed oil, soybean oil, coconut oil, and sunflower oil.

[0015] As a preferred technical solution of the present invention, the oily liquid includes ester liquid and vegetable oil in a weight ratio of 1:(0.2-0.4).

[0016] As a preferred technical solution of the present invention, the raw materials for preparing the granules further include 1 to 5 parts of a diffusing agent and 0.1 to 3 parts of a dispersant in parts by weight.

[0017] As a preferred technical solution of the present invention, the diffusing agent includes silicone polyoxyethylene ether, which is obtained by graft copolymerization of polyether and dimethylsiloxane. Examples of silicone polyoxyethylene ether include but are not limited to DM-MSD9196 (HLB is 7.8), DM-MSD9113 (HLB is 8.1), MSD9103 (HLB is 11.8), and MSD9101 (HLB is 13.4) of Qingdao Meiside Silicone Co., Ltd.

[0018] As a preferred technical solution of the present invention, the HLB of the silicone polyoxyethylene ether is 7 to 10, and examples thereof include 7, 8, 9, and 10.

[0019] As a preferred technical solution of the present invention, the dispersant includes at least one of lignin sulfonate and polycarboxylate. Examples of lignin sulfonate include, but are not limited to, sodium lignin sulfonate, potassium lignin sulfonate, calcium lignin sulfonate, and magnesium lignin sulfonate. Calcium lignin sulfonate and magnesium lignin sulfonate are preferred.

[0020] Currently, granules are generally prepared by coating medicinal powder with a carrier and a binder, which has problems such as weak coating strength and poor fluidity of the resulting granules. If used for aerial spraying, problems such as outlet blockage and dust flying are prone to occur. The present invention, by preparing the active ingredient powder into a medicinal liquid and using a carrier with a larger particle size and a spherical or spherical shape for adsorption, obtains granules with a more uniform shape and suitable gravity, which can reduce problems such as dust flying during aerial spraying operations.

[0021] However, the inventors also found that the present invention uses a carrier with a larger particle size, which makes it difficult to completely adsorb the drug solution. The drug solution remaining on the surface will cause part of the drug solution to be exposed on the coating surface because of its different properties from the coating material, resulting in blockage of the outlet and easy adhesion after long-term storage. The inventors found that by adding suitable mobile liquids and dispersants and diffusing agents, the exposure of the drug solution to the coating surface can be reduced, avoiding problems such as blockage of the coating and adhesion during storage.

[0022] This may be because, by adding chain ester liquids of a certain length, and vegetable oils containing fatty acids of a certain chain length, and adding low HLB organosilicon polyoxyethylene ether, lignin sulfonate, and the effective ingredients, a structure with lignin sulfonate and vegetable oil inside and organosilicon polyoxyethylene ether and ester liquid outside can be formed on the surface of the organic component. When mixed with a carrier, such as activated attapulgite, the anionic sulfonate on the surface of the organic component and the adsorption of the attapulgite surface, and cation exchange, drive the organic component and the ester liquid and organosilicon polyoxyethylene ether and attapulgite outside the organic component to react. Because of the low intermolecular force of silicone in organosilicon polyoxyethylene ether and the effect of flexible polyoxyethylene ether, organic components, oily liquids, diffusants, dispersants, etc. are promoted to enter the interior of the carrier, reducing the residual liquid medicine outside the carrier, thereby avoiding blockage and adhesion caused by exposure of the liquid medicine to the surface.

[0023] As a preferred technical solution of the present invention, the water-soluble coating material is selected from one or more of hydroxypropyl methylcellulose, hydroxypropyl cellulose, polyvinyl pyrrolidone, povidone, and polyvinyl alcohol.

[0024] Examples of polyvinyl alcohol include PVA 1788 (average degree of polymerization of 1700, degree of alcoholysis of 87-89%), PVA 2088 (average degree of polymerization of 2000, degree of alcoholysis of 87-89%), PVA2488 (average degree of polymerization of 2400, degree of alcoholysis of 87-89%), and PVA0588 (average degree of polymerization of 500, degree of alcoholysis of 87-89%). Polyvinyl alcohol is obtained by alcoholysis of polyvinyl acetate. The degree of alcoholysis is the percentage of alcoholysed functional groups in the total functional groups, and the degree of polymerization is the number of monomers in the macromolecule.

[0025] To achieve controlled release in aqueous environments, the inventors discovered that the alcoholysis degree of polyvinyl alcohol should not be too high, as this hinders dissolution in water. The average degree of polymerization of the polyvinyl alcohol is 500 to 3000, preferably 1000 to 3000, and more preferably 1500 to 3000. The alcoholysis degree is less than 90%, preferably 70 to 90%, and more preferably 80 to 90%.

[0026] Examples of polyvinyl pyrrolidone include PVPK17, PVP K30, PVP K60, and PVP K90 manufactured by Shandong Guangshen Electronic Technology Co., Ltd. The K value of the polyvinyl pyrrolidone is 15-30.

[0027] As a preferred technical solution of the present invention, the weight ratio of polyvinyl alcohol to polyvinyl pyrrolidone is 1:(0.1-0.3).

[0028] Currently, granules are released directly after reaching the target area, which easily leads to waste of liquid medicine. The present invention coats the surface of the granules, for example, using a water-soluble material such as polyvinyl alcohol for coating, which can control the conditions for the release of the granules. When the granules come into contact with water or when the humidity is high, the coating material dissolves and the liquid medicine is released, achieving a controlled release effect. The invention is particularly suitable for controlling pests or diseases in humid or watery environments and reduces dust generation.

[0029] However, the inventors also found that because the water-soluble materials used in the present invention, such as polyvinyl alcohol, form a relatively soft coating film, and are mutually repelled by the oily liquid of the drug solution, the water-soluble materials, such as polyvinyl alcohol, have poor adsorption properties, which increases the occurrence of shedding. The shedding of the coating will also cause the loss of the drug solution. The inventors found that by adding polyvinyl pyrrolidone with a lower molecular weight and polyvinyl alcohol with a suitable molecular weight as coating materials, and adding vegetable oil to the oily liquid, the stability of the coating can be promoted and shedding can be reduced.

[0030] This may be because during the coating process, by using polyvinyl pyrrolidone and polyvinyl alcohol for coating together, the structure of polyvinyl pyrrolidone can be evenly cross-linked on the formed polyvinyl alcohol coating film, so that on the one hand, while the polyvinyl alcohol hydroxyl group and the carrier hydroxyl group act on each other, the ring structure of polyvinyl pyrrolidone further supports the coating film. At the same time, its relatively polar ring structure also reduces the repulsion of oily liquids, thereby further increasing the adsorption of the coating film and avoiding shedding.

[0031] As a preferred technical solution of the present invention, the diffusant also includes at least one of alkylphenol polyoxyethylene ether and fatty alcohol polyoxyethylene ether, and the weight ratio of the silicone polyoxyethylene ether to at least one of alkylphenol polyoxyethylene ether and fatty alcohol polyoxyethylene ether is (2 to 4):1.

[0032] Examples of alkylphenol polyoxyethylene ethers include, but are not limited to, octylphenol polyoxyethylene ethers, such as OP-4 (HLB 8-8.6), OP-7 (HLB 11.5-12.5), OP-9 (HLB 12.7-13.4), OP-10 (HLB 13.3-14), OP-13 (HLB 14), OP-15 (HLB 15), OP-20 (HLB 16), OP-30 (HLB 17), OP-40 (HLB 18), and OP-50 (HLB 19) of the sea anemone. The HLB of the alkylphenol polyoxyethylene ethers is 11-16.

[0033] Examples of fatty alcohol polyoxyethylene ethers include, but are not limited to, oleyl alcohol polyoxyethylene ethers, such as OV-3 (HLB 6), OV-5 (HLB 8), OV-10 (HLB 12.4), OV-15, OV-20 (HLB 15.4), and OV-24 of sea stone flower, isodecyl alcohol polyoxyethylene ethers, such as E-1007 and E-1009 of sea stone flower, C16-18 fatty alcohol polyoxyethylene ethers, such as O- 8 (HLB is 11-12), O-9 (HLB is 12-12.5), O-10 (HLB is 12.5-13), O-15 (HLB is 14-15), O-20 (HLB is 15-16), C12-14 fatty alcohol polyoxyethylene ether, such as MOA-7 (HLB is 12-13), MOA-19 (HLB is 13-14), MOA-15 ​​(HLB is 15-16) of sea anise. The HLB of the fatty alcohol polyoxyethylene ether is 11-16.

[0034] As a preferred technical solution of the present invention, the dispersant further includes an EO-PO block copolymer, and the weight ratio of at least one of the lignin sulfonate and polycarboxylate to the EO-PO block copolymer is (2-4):1.

[0035] Examples of EO-PO block copolymers include, but are not limited to, BASF's RPE1740 (40% EO content), RPE1720 (20% EO content), RPE2520 (20% EO content), RPE3110 (10% EO content), RPE 2035 (35% EO content), RPE 2520 (20% EO content), and RPE 2525 (25% EO content). The EO content is the mole percentage of EO to PO in the EO-PO block copolymer. The EO content of the EO-PO block copolymer is 20-50%, preferably 25-50%, and more preferably 30-50%.

[0036] The inventors discovered that while using both polyvinyl alcohol and polyvinyl pyrrolidone as coating materials improves coating adsorption and strength, the polar ring structure in polyvinyl pyrrolidone can cause some dissolution with the internal drug solution over time or at high temperatures, leading to partial adhesion. The inventors discovered that using a longer-chain oily liquid and adding appropriate diffusing and dispersing agents can reduce dissolution of the coating and improve high-temperature fluidity.

[0037] This may be because when adding longer-chain oily liquids, such as the chain length of ester liquids, and controlling the amount of vegetable oil, the polarity of the drug solution can be controlled, which can reduce compatibility with polyvinyl pyrrolidone in the coating film. At the same time, adding hydroxy polyoxyethylene ether with a higher HLB and EO-PO block copolymer with a higher EO value, and utilizing the difference in lipophilicity between hydroxy polyoxyethylene ether and block polyether, the outer layer of the drug solution is mainly composed of polyoxyethylene ether and EO blocks of block polyether, reducing the contact between the oily liquid in the drug solution and the coating material, further reducing the rejection of the oily liquid to the coating, improving high-temperature fluidity, and reducing the occurrence of shedding.

[0038] The second aspect of the present invention provides a method for preparing the controlled-release granules for aerial pest control, comprising:

[0039] Preparation of adsorbent liquid: The active ingredient, oily liquid, wetting agent and dispersant are blended and ground to obtain an adsorbent liquid with a particle size D90 less than 3 μm;

[0040] Carrier adsorption: The adsorbent liquid and the carrier are stirred and adsorbed to obtain a loaded liquid. The mixing and stirring time of the present invention is not specifically limited, and the adsorbent liquid can be adsorbed into the carrier.

[0041] Coating: putting the loaded drug solution into a coating machine, adding a water-soluble coating material for coating to obtain the granules.

[0042] The inventors discovered that by controlling the particle size of the drug solution, while promoting the adsorption of the drug solution and the carrier, during the controlled release process, as the coating dissolves, the drug solution of appropriate particle size is released into water or a humid environment. The spreading effect of the oily liquid, dispersant and diffusant of the drug solution can be utilized to promote the uniform diffusion of small-particle active ingredients and increase the range of action of the drug solution.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] (1) The granules of the present invention are suitable for aerial spraying operations. Using drones to spread the granules in beaches, ditches, etc. is more convenient and more efficient, saving time and effort.

[0045] (2) The preparation method adopted by the present invention is as follows: after the adsorption carrier absorbs the drug solution, the carrier is coated with a film-forming agent. The granules prepared by this method have an outer layer coated with a film-forming agent, which has good strength. During the drone spraying operation, there is no dust and no waste of drug.

[0046] (3) The granular carrier used in the present invention is a spherical or nearly spherical regular carrier particle with a narrow particle size distribution range, uniform size, good fluidity, and smooth feeding, which is convenient for drone spreading and more uniform.

[0047] (4) The granules of the present invention are coated with a moisture-sensitive film-forming material. Only when there is water, moisture or high humidity in the target area will the film-forming material dissolve and the drug solution be released, thereby achieving controlled release and increasing the scope of action of the drug.

[0048] (5) The drug liquid adsorbed by the granular carrier of the present invention is an oily drug liquid. When it comes into contact with water, it will spread along the water-wetting surface, thereby increasing the scope of action of the drug. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 This is a picture of the granular agent provided in Example 1 being applied to the soil through aerial spraying. DETAILED DESCRIPTION

[0050] Example

[0051] Example 1

[0052] This example provides a granule, and the raw materials for preparing the granule include, by weight, 8 parts of an active ingredient, 10 parts of an oily liquid, 4 parts of a water-soluble coating material, 3 parts of a diffusing agent, 1 part of a dispersant, and a carrier to make up to 100 parts; the active ingredient is niclosamide ethanolamine salt, the carrier is heat-activated attapulgite, and when heat-activated, it is heated at 250°C. The shape of the carrier is spherical, and the particle size of the carrier ranges from 1 to 3 mm. The oily liquid is selected from an ester liquid and a vegetable oil in a weight ratio of 1:0.3, the ester liquid is selected from methyl oleate, and the vegetable oil is selected from soybean oil. The diffusing agent includes silicone polyoxyethylene ether DM-MSD9196 and alkylphenol polyoxyethylene ether OP-9 in a weight ratio of 3:1, the dispersant includes calcium lignin sulfonate and EO-PO block copolymer RPE1740 in a weight ratio of 3:1, and the water-soluble coating material is selected from polyvinyl alcohol PVA2088 and polyvinyl pyrrolidone PVP K17, weight ratio is 1:0.2.

[0053] This example also provides a method for preparing the granules as described above, comprising:

[0054] Preparation of adsorbent liquid: The active ingredient, oily liquid, wetting agent and dispersant are blended and ground to obtain an adsorbent liquid with a particle size D90 less than 3 μm;

[0055] Carrier adsorption: Place the carrier into a blender, spray the adsorbent solution, stir and adsorb to obtain the loaded solution;

[0056] Coating: putting the loaded drug solution into a coating machine, dissolving the water-soluble coating material in anhydrous ethanol and spraying it into the coating machine for coating, and drying to obtain the granules.

[0057] Example 2

[0058] This example provides a granule, and the raw materials for preparing the granule include, by weight, 10 parts of an active ingredient, 14 parts of an oily liquid, 5 parts of a water-soluble coating material, 5 parts of a diffusing agent, 2 parts of a dispersant, and a carrier to make up to 100 parts. The active ingredient is niclosamide, and the carrier is heat-activated attapulgite. When heat-activated, it is heated at 300°C. The shape of the carrier is spherical, and the particle size of the carrier ranges from 1 to 3 mm. The oily liquid is selected from an ester liquid and a vegetable oil in a weight ratio of 1:0.4. The ester liquid is selected from butyl oleate, and the vegetable oil is selected from coconut oil. The diffusing agent includes silicone polyoxyethylene ether DM-MSD9113 and fatty alcohol polyoxyethylene ether OV-10 in a weight ratio of 4:1. The dispersant includes magnesium lignin sulfonate and EO-PO block copolymer RPE 2035 in a weight ratio of 4:1. The water-soluble coating material is selected from polyvinyl alcohol PVA2488 and polyvinyl pyrrolidone PVP. K30, weight ratio is 1:0.3.

[0059] This example also provides a method for preparing the granules as described above, comprising:

[0060] Preparation of adsorbent liquid: The active ingredient, oily liquid, wetting agent and dispersant are blended and ground to obtain an adsorbent liquid with a particle size D90 less than 3 μm;

[0061] Carrier adsorption: Place the carrier into a blender, spray the adsorbent solution, stir and adsorb to obtain the loaded solution;

[0062] Coating: putting the loaded drug solution into a coating machine, dissolving the water-soluble coating material in anhydrous ethanol and spraying it into the coating machine for coating, and drying to obtain the granules.

[0063] Example 3

[0064] This example provides a granule, wherein the raw materials for preparing the granule include, by weight, 5 parts of an active ingredient, 7 parts of an oily liquid, 3 parts of a water-soluble coating material, 2 parts of a diffusing agent, 0.8 parts of a dispersant, and a carrier to make up to 100 parts. The active ingredient is calcium cyanamide, the carrier is heat-activated attapulgite, and when heat-activated, the carrier is heated at 230° C. The shape of the carrier is spherical, and the particle size of the carrier ranges from 1 to 3 mm. The oily liquid is selected from an ester liquid and a vegetable oil in a weight ratio of 1:0.2, the ester liquid is selected from methyl palmitate, and the vegetable oil is selected from corn oil. The diffusing agent includes organosilicon polyoxyethylene ether DM-MSD9113 and fatty alcohol polyoxyethylene ether MOA-15 ​​in a weight ratio of 2:1. The dispersant includes magnesium lignin sulfonate and EO-PO block copolymer RPE 2035 in a weight ratio of 2:1. The water-soluble coating material is selected from polyvinyl alcohol PVA1788 and polyvinyl pyrrolidone PVP. K17, weight ratio is 1:0.1.

[0065] This example also provides a method for preparing the granules as described above, comprising:

[0066] Preparation of adsorbent liquid: The active ingredient, oily liquid, wetting agent and dispersant are blended and ground to obtain an adsorbent liquid with a particle size D90 less than 3 μm;

[0067] Carrier adsorption: Place the carrier into a blender, spray the adsorbent solution, stir and adsorb to obtain the loaded solution;

[0068] Coating: putting the loaded drug solution into a coating machine, dissolving the water-soluble coating material in anhydrous ethanol and spraying it into the coating machine for coating, and drying to obtain the granules.

[0069] Example 4

[0070] This example provides a granule. The raw materials for preparing the granule include, by weight, 8 parts of an active ingredient, 10 parts of an oily liquid, 4 parts of a water-soluble coating material, 3 parts of a diffusing agent, 1 part of a dispersant, and the carrier is supplemented to 100 parts. The active ingredient is niclosamide ethanolamine salt, the carrier is heat-activated attapulgite, and when heat-activated, it is heated at 250°C. The shape of the carrier is spherical, and the particle size of the carrier ranges from 1 to 3 mm. The oily liquid is selected from an ester liquid, and the ester liquid is selected from methyl oleate. The diffusing agent includes silicone polyoxyethylene ether DM-MSD9196 and alkylphenol polyoxyethylene ether OP-9, in a weight ratio of 3:1. The dispersant includes calcium lignin sulfonate and EO-PO block copolymer RPE1740, in a weight ratio of 3:1. The water-soluble coating material is selected from polyvinyl alcohol PVA 2088 and polyvinyl pyrrolidone PVP K17, in a weight ratio of 1:0.2.

[0071] This example also provides a method for preparing the granules as described above, comprising:

[0072] Preparation of adsorbent liquid: The active ingredient, oily liquid, wetting agent and dispersant are blended and ground to obtain an adsorbent liquid with a particle size D90 less than 3 μm;

[0073] Carrier adsorption: Place the carrier into a blender, spray the adsorbent solution, stir and adsorb to obtain the loaded solution;

[0074] Coating: putting the loaded drug solution into a coating machine, dissolving the water-soluble coating material in anhydrous ethanol and spraying it into the coating machine for coating, and drying to obtain the granules.

[0075] Example 5

[0076] This example provides a granule preparation, and the raw materials for preparing the granule preparation include, by weight, 8 parts of an active ingredient, 10 parts of an oily liquid, 4 parts of a water-soluble coating material, 3 parts of a diffusing agent, 1 part of a dispersant, and a carrier to make up to 100 parts; the active ingredient is niclosamide ethanolamine salt, the carrier is heat-activated attapulgite, and when heat-activated, it is heated at 250°C. The shape of the carrier is spherical, and the particle size range of the carrier is 1 to 3 mm. The oily liquid is selected from an ester liquid and a vegetable oil, and the weight ratio is 1:0.3. The ester liquid is selected from methyl oleate, and the vegetable oil is selected from soybean oil. The diffusing agent includes silicone polyoxyethylene ether DM-MSD9196, the dispersant includes calcium lignin sulfonate, and the water-soluble coating material is selected from polyvinyl alcohol PVA 2088 and polyvinyl pyrrolidone PVP K17, and the weight ratio is 1:0.2.

[0077] This example also provides a method for preparing the granules as described above, comprising:

[0078] Preparation of adsorbent liquid: The active ingredient, oily liquid, wetting agent and dispersant are blended and ground to obtain an adsorbent liquid with a particle size D90 less than 3 μm;

[0079] Carrier adsorption: Place the carrier into a blender, spray the adsorbent solution, stir and adsorb to obtain the loaded solution;

[0080] Coating: putting the loaded drug solution into a coating machine, dissolving the water-soluble coating material in anhydrous ethanol and spraying it into the coating machine for coating, and drying to obtain the granules.

[0081] Performance evaluation

[0082] 1. Flying spray test: The granules provided in Example 1 were subjected to flying spray test, wherein the flying height was 3.5 m-4 m and the speed was 5 m / s for spraying the granules. The granules sprayed on the ground were as follows: Figure 1 The particles are shown in Figure 1 It can be seen that the granules of the present invention are sprayed evenly, and the granules do not stick to each other. Moreover, during the 8-hour spraying process, there is no problem of clogging of the spraying port, and the operation is good.

[0083] 2. Flowability: The flowability of the granules provided in Examples 1-5 after storage at 23°C and 54°C for 14 days was observed. Excellent indicates good flowability with no sticking, good indicates relatively good flowability with less than 2% sticking of the granules, fair indicates fair flowability with 2-5% sticking of the granules, and poor indicates poor flowability with more than 5% sticking of the granules. The results are shown in Table 1.

[0084] 3. Shedding rate: The granules provided in Examples 1 to 5 were vibrated at a vibration frequency of 150 times / min for 30 min. The masses before and after vibration were measured as m0 and m1. The shedding rate was (m0-m1) / m0*100%. The results are shown in Table 1.

[0085] 4. Performance test: The moisture content and bulk density of Examples 1 to 3 were tested, and it was found that the moisture content was <3% and the bulk density was 1.1 to 1.5 g / mL.

[0086] Table 1 Performance characterization test

[0087]

[0088] As can be seen from the test results in Table 1, the granules provided by the present invention have good controlled-release properties. When used in aerial spraying operations, they can avoid problems such as clogging of openings and flying dust, thereby improving the efficiency of granule spraying and reducing labor costs.

[0089] It should be understood that the embodiments described herein should be considered in a descriptive sense only and not for limiting purposes. Descriptions of features, advantages, or aspects within each embodiment should be considered applicable to other similar features, advantages, or aspects in other embodiments.

Claims

1. A controlled-release granule for aerial pest control, characterized in that: The raw materials for preparing the granules include, by weight, 5 to 40 parts of active ingredients, 5 to 30 parts of oily liquid, 0.5 to 5 parts of water-soluble coating material, 1 to 5 parts of diffusing agent, 0.1 to 3 parts of dispersant, and the carrier is supplemented to 100 parts. The carrier is spherical or quasi-spherical in shape, with a particle size ranging from 1 to 3 mm; The oily liquid includes an ester liquid and a vegetable oil in a weight ratio of 1:(0.2-0.4); The water-soluble coating material includes polyvinyl alcohol and polyvinyl pyrrolidone in a weight ratio of 1:(0.1-0.3); The average degree of polymerization of the polyvinyl alcohol is 1500 to 3000, and the K value of the polyvinyl pyrrolidone is 15 to 30; The diffusing agent includes organic silicon polyoxyethylene ether and at least one of alkylphenol polyoxyethylene ether and fatty alcohol polyoxyethylene ether; the weight ratio of organic silicon polyoxyethylene ether to at least one of alkylphenol polyoxyethylene ether and fatty alcohol polyoxyethylene ether is (2-4):1; The dispersant includes at least one of lignin sulfonate and polycarboxylate; and also includes EO-PO block copolymer, wherein the weight ratio of at least one of lignin sulfonate and polycarboxylate to EO-PO block copolymer is (2-4):1; The carbon number of the ester liquid is 10-25.

2. The controlled-release granules for aerial pest control according to claim 1, characterized in that The vegetable oil is selected from one or more of corn oil, rapeseed oil, soybean oil, coconut oil and sunflower oil.

3. A method for preparing the controlled-release granules for aerial pest control according to claim 2, characterized in that: include: Preparation of adsorbent liquid: The active ingredient, oily liquid, wetting agent and dispersant are blended and ground to obtain an adsorbent liquid with a particle size D90 less than 3 μm; Carrier adsorption: The adsorbent liquid and the carrier are stirred and adsorbed to obtain the loaded liquid; Coating: putting the loaded drug solution into a coating machine, adding a water-soluble coating material for coating to obtain the granules.

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