A water-dispersible granule of chlorthiazoline·acetamiprid and its preparation method

Abstract

This application relates to the field of pesticide compositions, specifically disclosing a water-dispersible granule of chlorpyrifos·acetamiprid and its preparation method, comprising the following raw materials in parts by weight: chlorpyrifos 40-50 parts; acetamiprid 15-25 parts; dispersant 8-12 parts; emulsifier 3-7 parts; synergist 0.5-1 part; mineral oil 3-5 parts; anti-caking agent 3-5.5 parts; cassava starch 2-8 parts; activated carbon powder 5.5-8 parts. The preparation method includes the following steps: S1, mixing the raw materials evenly according to the specified ratio; S2, granulating after air jet milling, drying, and sieving to obtain the water-dispersible granule. This application has the effect of inhibiting the migration of acetamiprid in the soil and reducing pesticide pollution of water resources.

Description

Technical Field

[0001] This application relates to the field of pesticide compositions, and in particular to a chlorthiazoline·acetamiprid water-dispersible granule and its preparation method. Background Technology

[0002] Pesticides are an important means of controlling plant diseases, pests, and weeds. Their application makes a significant contribution to ensuring high and stable yields in agriculture, forestry, and ranching industries, as well as protecting the environment from pest threats. Pesticides can be classified according to their formulation, including water-dispersible granules, soluble powders, emulsions, oils, and microgranules. Among these, water-dispersible granules, also known as dry suspensions or wettable powders, disintegrate and disperse rapidly in water, forming a highly suspended solid-liquid dispersion system. They offer advantages such as good safety, absence of organic solvents, and no dust, leading to their rapid development in the pesticide field.

[0003] Chlorthiazoline is a neonicotinoid insecticide with high efficiency, low toxicity, broad spectrum, and no temperature limitations. It has contact and systemic activity. It can selectively inhibit the binding of nicotinic acid acetylcholinesterase receptors in the insect nervous system, thereby disrupting the normal conduction of the central nervous system. This causes the insects to become paralyzed and die due to the obstruction of the normal conduction of the central nervous system. It is mainly used to control aphids on cruciferous vegetables, citrus aphids, whiteflies, rice planthoppers, tea leafhoppers, etc.

[0004] Acetaminophen has systemic and penetrating action, but no contact action. It blocks nerve conduction at insect synaptic receptors, thus exerting ovicidal, feeding-inhibiting, oviposition-inhibiting, and fungicidal effects. It is mainly used to control piercing-sucking pests such as aphids, rice planthoppers, tobacco whiteflies, pear psyllids, and leafhoppers, as well as thrips. However, acetamiprid is prone to phytotoxicity at high temperatures. When used in combination with chlorothiazoline, it can improve the stability of the composition in high-temperature environments.

[0005] Radishes, cauliflower, and cabbage are suitable for growing in sandy soil. When pesticide combinations are used to kill insects on these plants, the combination of acetamiprid and chlorothiazide falls on the surface of the sandy soil. Acetaminophen migrates in the soil and can easily enter the groundwater connected to rivers. Acetaminophen is toxic to aquatic animals, causing them to be poisoned. Summary of the Invention

[0006] In order to inhibit the migration of acetamiprid in the soil and reduce pesticide pollution to water resources, this application provides a chlorthiazoline-acetamiprid water-dispersible granule and a preparation method thereof.

[0007] In the first aspect, the chlorthiazoline·acetamiprid water-dispersible granules provided in this application adopt the following technical solution: A chlorthiazoline·acetamiprid water-dispersible granule comprises the following raw materials in parts by weight: chlorthiazoline 40-50 parts; acetamiprid 15-25 parts; dispersant 8-12 parts; emulsifier 3-7 parts; synergist 0.5-1 part; mineral oil 3-5 parts; anti-caking agent 3-5.5 parts; cassava starch 2-8 parts; activated carbon powder 5.5-8 parts.

[0008] By adopting the above technical solutions, the combination of chlorthiazoline and acetamiprid improves insecticidal efficiency. When preparing water-dispersible granules, the combination of mineral oil, anti-caking agents, and dispersants reduces the probability of cassava starch and activated carbon powder agglomeration. After pesticide application, the combination of cassava starch and activated carbon powder increases the viscosity of the pesticide, allowing it to adhere to the plant surface and reducing the probability of pesticide entering the soil. After the pesticide enters the soil, chlorthiazoline degrades in the soil, and the combination of acetamiprid, cassava starch, and activated carbon powder allows activated carbon particles to adsorb acetamiprid, while the paste formed by cassava starch increases the bonding strength between activated carbon and soil particles, reducing the migration rate of acetamiprid in the soil. Over time, under the influence of light and soil microorganisms, acetamiprid and chlorthiazoline decompose, reducing pesticide pollution of water resources.

[0009] Optionally, the anti-caking agent includes sodium oleate and potassium ferrocyanide, wherein the weight ratio of sodium oleate to potassium ferrocyanide is (6-8):3.

[0010] By adopting the above technical solution, during the storage of water-dispersible granules, the hydrophobic groups of sodium oleate, in combination with potassium ferrocyanide, prevent water molecules from penetrating into the granules, reducing the probability of the water-dispersible granules becoming damp and sticking together. During the preparation and formulation of pesticides using water-dispersible granules, sodium oleate, chlorpyrifos, and acetamiprid are adsorbed through polar adsorption. After application, when the pesticide comes into contact with the ground, sodium oleate adsorbs onto the surface of silica particles in the sandy soil, thereby fixing acetamiprid in the sandy soil, hindering its migration in the soil, and reducing pesticide pollution to water resources.

[0011] Optionally, the dispersant is selected from dispersants whose aqueous solution is acidic.

[0012] By employing the above technical solution, the acidic dispersant, in combination with chlorthiazoline and acetamiprid, reduces the probability of degradation of chlorthiazoline and acetamiprid, thereby improving the stability of water-dispersible granules. During the preparation of pesticides using water-dispersible granules, the viscosity of sodium oleate increases under the influence of water. Its combination with cassava starch and activated carbon powder enhances the adhesion of pesticides to plant stems and leaves, hinders the migration of acetamiprid in the soil, and reduces pesticide pollution of water resources.

[0013] Optionally, the dispersant is selected from sodium hexametaphosphate.

[0014] By adopting the above technical solution, the addition of sodium oleate and potassium ferrocyanide reduces the hygroscopicity of sodium hexametaphosphate, thereby reducing the probability of water-dispersible granules agglomerating.

[0015] Optionally, the emulsifier is selected from sodium dodecyl sulfate.

[0016] By adopting the above technical solution, sodium dodecyl sulfate provides emulsifying properties and, in combination with sodium oleate and sodium hexametaphosphate, acts as a buffer, reducing the probability of pesticide performance degradation due to acid-base changes during pesticide preparation, and improving the stability of chlorthiazoline and acetamiprid.

[0017] Optionally, the activated carbon powder is selected from wood-based activated carbon powder.

[0018] By adopting the above technical solution, compared with coal-based activated carbon, wood-based activated carbon has lower ash content, fewer impurities, and well-developed micropores and mesopores, which facilitates the loading of chlorthiazoline and acetamiprid, reduces the degradation rate of chlorthiazoline and acetamiprid under light, and improves the efficacy persistence of pesticides prepared by water-dispersible granules.

[0019] Optionally, the synergist is selected from humic acid-modified organosilicon powder.

[0020] By adopting the above technical solutions, humic acid-modified organosilicon powder possesses the low surface tension of organosilicon, easily clogging the stomata of pests. Combined with chlorpyrifos and acetamiprid, it improves the insecticidal effect of water-dispersible granules. The combination of humic acid-modified organosilicon powder and mineral oil enhances the sealing effect of pesticides on pest stomata. After pesticide application, the combination of mineral oil and humic acid-modified organosilicon powder aqueous solution facilitates pesticide spread on plant roots and stems, improving pesticide adhesion to insects and facilitating the action of chlorpyrifos. Humic acid-modified organosilicon is less likely to penetrate plants, reducing pesticide damage. After pesticides fall into the soil, humic acid promotes the growth of soil microorganisms, increasing the degradation rate of chlorpyrifos and acetamiprid, hindering the migration of acetamiprid in the soil, and reducing pesticide pollution to water resources.

[0021] Optionally, the preparation of the humic acid modified organosilicon powder includes the following steps: placing the organosilicon solution and dried humic acid in a sealed container, stirring at 80-90℃ for 20-30 minutes, taking it out and baking at 110-130℃ for 2-4 hours, then grinding and sieving to obtain the powder.

[0022] By adopting the above technical solution, through stirring and heating, humic acid and organosilicon are fully cross-linked. After drying, the humic acid-modified organosilicon powder forms an adhesive substance when it comes into contact with water. The particle size of this substance is larger than that of organosilicon, and its surface tension is also slightly greater than that of organosilicon. Therefore, it is not easy for it to penetrate into the plant from the stomata, thus reducing the phytotoxicity of pesticides.

[0023] Secondly, the preparation method of the chlorthiazoline·acetamiprid water-dispersible granules provided in this application adopts the following technical solution:

[0024] A method for preparing a chlorthiazoline·acetamiprid water-dispersible granule includes the following steps:

[0025] S1. Mix all raw materials evenly according to the specified ratio;

[0026] S2. After air jet milling, granulation, drying, and sieving, water-dispersible granules are obtained.

[0027] By adopting the above technical solution, the preparation process is simple, the raw materials are evenly dispersed, the product performance is stable, and it is easy to store.

[0028] In summary, this application includes at least one of the following beneficial technical effects:

[0029] 1. After application, the pesticide prepared as a water-dispersible granule increases its viscosity due to the combination of cassava starch and activated carbon powder, allowing it to adhere to the plant surface. Mineral oil and humic acid-modified organosilicon powder further expand the pesticide's reach on the plant's stems and leaves, increasing coverage and facilitating pest trapping, thus reducing the probability of pesticide entry into the soil. Once in the soil, chlorpyrifos degrades. The combination of acetamiprid, cassava starch, and activated carbon powder allows the activated carbon particles to adsorb acetamiprid, while the cassava starch paste strengthens the bond between activated carbon and soil particles, reducing the migration rate of acetamiprid in the soil. The humic acid-modified organosilicon powder enhances the activity of soil microorganisms. Over time, under the influence of light and soil microorganisms, acetamiprid and chlorpyrifos decompose, reducing pesticide pollution of water resources.

[0030] 2. Under the action of mineral oil and humic acid modified organosilicon, after the pesticide spreads on the stems and leaves of the plant, due to the modification of humic acid, the modified organosilicon is not easy to penetrate into the plant from the stomata, thus reducing the phytotoxicity of water-dispersible granules.

[0031] 3. During the storage of water-dispersible granules, the hydrophobic groups of sodium oleate, in conjunction with potassium ferrocyanide, prevent water molecules from penetrating into the granules, reducing the probability of moisture absorption and adhesion. In the preparation and formulation of pesticides using water-dispersible granules, sodium oleate, chlorpyrifos, and acetamiprid, through polar adsorption, after application, when the pesticide comes into contact with the ground, sodium oleate adheres to the surface of silica particles in the sandy soil, thereby immobilizing acetamiprid in the sandy soil, hindering its migration and reducing pesticide pollution to water resources.

[0032] 4. Wood-based activated carbon has low ash content and few impurities, and its micropores and mesopores are well-developed, which facilitates the loading of chlorthiazoline and acetamiprid. It plays a slow-release role for chlorthiazoline and acetamiprid, reduces the degradation rate of chlorthiazoline and acetamiprid in natural environments such as light, and improves the efficacy persistence of pesticides prepared by water-dispersible granules. Detailed Implementation

[0033] The present application will be further described in detail below with reference to embodiments and comparative examples.

[0034] Unless otherwise specified, the following examples shall be conducted under conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, all raw materials used in the following examples shall be commercially available.

[0035] Chlorpyrifos, technical grade, purity 99%; acetamiprid, technical grade, heavy metals 10 ppm, purity 99%, acidity coefficient 2.46±0.70; mineral oil, pesticide white oil, purity 25 cSt (40℃); potassium ferrocyanide, density 1.85 g / cm³ 3 The activated carbon powder is selected from wood-based activated carbon powder with a particle size of 325 mesh; the humic acid is of industrial grade with a purity of 99%; the viscosity of the organosilicon solution (at 25℃) is 315 mPa·s, and the pH value is 6.21.

[0036] Preparation Example

[0037] The organosilicon solution and dried humic acid were placed in a sealed container and stirred at 85°C for 25 minutes. After being removed, the mixture was baked at 120°C for 3 hours. The mixture was then ground and sieved to obtain humic acid-modified organosilicon powder with a particle size of 325 mesh.

[0038] Example

[0039] Example 1

[0040] S1. Mix 1 kg of sodium oleate and 0.5 kg of potassium ferrocyanide evenly as an anti-caking agent; mix 20 kg of chlorothiazoline, 12.5 kg of acetamiprid, 4 kg of sodium hexametaphosphate, 1.5 kg of sodium dodecyl sulfate, 2.5 kg of mineral oil, the above anti-caking agent, 4 kg of cassava starch, and 4 kg of activated carbon powder, and stir evenly at room temperature at a stirring speed of 550 rpm to obtain a mixed solution;

[0041] S2. The mixed drug solution is granulated after being pulverized by airflow, dried in a vacuum drying oven at 40℃ for 20 minutes, and then sieved to obtain water-dispersible granules with a particle size of 1 mm.

[0042] Example 2

[0043] S1. Mix 1.5 kg of sodium oleate and 0.6 kg of potassium ferrocyanide evenly as an anti-caking agent; mix 22.5 kg of chlorothiazoline, 10 kg of acetamiprid, 5 kg of sodium hexametaphosphate, 2.5 kg of sodium dodecyl sulfate, 2 kg of mineral oil, the above anti-caking agent, 2.5 kg of cassava starch, and 3.4 kg of activated carbon powder, and stir evenly at room temperature at a stirring speed of 550 rpm to obtain a mixed solution;

[0044] S2. The mixed drug solution is granulated after being pulverized by airflow, dried in a vacuum drying oven at 40℃ for 20 minutes, and then sieved to obtain water-dispersible granules with a particle size of 1 mm.

[0045] Example 3

[0046] S1. Mix 2 kg of sodium oleate and 0.75 kg of potassium ferrocyanide evenly as an anti-caking agent; mix 25 kg of chlorothiazoline, 7.5 kg of acetamiprid, 6 kg of sodium hexametaphosphate, 3.5 kg of sodium dodecyl sulfate, 1.5 kg of mineral oil, the above anti-caking agent, 1 kg of cassava starch, and 2.75 kg of activated carbon powder, and stir evenly at room temperature at a stirring speed of 550 rpm to obtain a mixed solution.

[0047] S2. The mixed drug solution is granulated after being pulverized by airflow, dried in a vacuum drying oven at 40℃ for 20 minutes, and then sieved to obtain water-dispersible granules with a particle size of 1 mm.

[0048] Example 4

[0049] The difference from Example 2 is that the amount of sodium oleate added is 1 kg.

[0050] Example 5

[0051] The difference from Example 2 is that the amount of sodium oleate added is 2 kg.

[0052] Example 6

[0053] The difference from Example 2 is that the amount of tapioca starch added is 1 kg.

[0054] Example 7

[0055] The difference from Example 2 is that the amount of tapioca starch added is 4 kg.

[0056] Example 8

[0057] The difference from Example 2 is that 0.25 kg of the humic acid modified organosilicon powder prepared in the preparation example is added to S1.

[0058] Example 9

[0059] The difference from Example 2 is that 0.35 kg of the humic acid modified organosilicon powder prepared in the preparation example is added to S1.

[0060] Example 10

[0061] The difference from Example 2 is that 0.5 kg of the humic acid modified organosilicon powder prepared in the preparation example is added to S1.

[0062] Comparative Example

[0063] Comparative Example 1

[0064] The difference from Example 2 is that no chlorothiazoline was added in S1, and the amount of acetamiprid added was 32.5 kg.

[0065] Comparative Example 2

[0066] The difference from Example 2 is that no acetamiprid was added in S1, and the amount of chlorothiazoline added was 32.5 kg.

[0067] Comparative Example 3

[0068] The difference from Example 2 is that sodium oleate was not added in S1.

[0069] Comparative Example 4

[0070] The difference from Example 2 is that potassium ferrocyanide was not added in S1.

[0071] Comparative Example 5

[0072] The difference from Example 2 is that no tapioca starch was added in S1.

[0073] Comparative Example 6

[0074] The difference from Example 2 is that no activated carbon powder was added in S1.

[0075] Table 1. Raw material list (kg) for the Examples and Comparative Examples

[0076]

[0077] Performance testing

[0078] Test methods

[0079] 1. Field experiment

[0080] Experimental crop: Radish experimental field, area 200m² 2 The density is 4500 nests / 667m³ 2 Each clump contains 2-3 plants, and the radish variety is Wanluo No. 1.

[0081] Experimental subject: Aphids;

[0082] Pesticide preparation: The water-dispersible granules prepared in the examples and comparative examples were diluted with water to prepare pesticides.

[0083] Dosage: 150 g / hm² based on the weight of chlorpyrifos and acetamiprid. 2 Spray volume 500 kg / hm 2 ;

[0084] The pesticide was divided into 64 zones, each separated by a buffer zone. Each pesticide prepared in each embodiment / comparative example was applied to three zones, and the application zones of the same embodiment / comparative example were not adjacent.

[0085] Application time and frequency:

[0086] The first application of pesticide was on August 14, 2022, when the radishes had grown to 6-7 leaves. There was no rain for five days after the application, followed by thunderstorms on the sixth day, with an average rainfall of 1.6 mm across the city. The seventh day was cloudy turning overcast. The highest temperature during the seven days was 35℃ and the lowest temperature was 22℃. The survey time and frequency were as follows: the first survey was conducted on August 14, 2022, before the application of pesticide; the second survey was conducted on August 20, 2022, seven days after the application of pesticide.

[0087] Survey method: Count the number of aphids on radish leaves and record the number of live insects.

[0088] Insect population reduction rate (%) = (Insect population before pesticide application - Insect population after pesticide application) / Insect population before pesticide application × 100%

[0089] Control efficacy (%) = (Pest population reduction rate in the treated area - Pest population reduction rate in the blank control area) / (100 - Pest population reduction rate in the blank control area) × 100%

[0090] The final control effect (%) was the average of the control effects calculated from the experimental fields with the same pesticide application. The experimental results are detailed in Table 2.

[0091] 2. Collect soil samples from the radish experimental field and test for pesticide residues in the soil. The specific steps are as follows:

[0092] Sampling: Take samples of deep soil (2m below ground level) the day after application;

[0093] Take a deep soil sample (2m below the ground) on the 7th day after application;

[0094] The results of the test using a combined mass spectrometry and liquid chromatography system (UHPLC-QTOF / MS) to determine the content of acetamiprid in soil (mg / kg) are detailed in Table 2.

[0095] Table 2. Test results data for each embodiment and comparative example.

[0096]

[0097]

[0098] Soil experiments revealed that, on the second day after application, no acetamiprid was detected in the soil for any of the water-dispersible granules prepared in the various examples. The presence of acetamiprid on the seventh day was primarily due to rain on the sixth day after application, which washed away some of the acetamiprid and allowed it to migrate into the soil.

[0099] Based on Examples 1, 2, and 3 and Table 2, it can be seen that by adjusting the amounts of chlorothiazoline, acetamiprid, sodium hexametaphosphate, sodium dodecyl sulfate, mineral oil, sodium oleate, potassium ferrocyanide, cassava starch, and activated carbon powder, a water-dispersible granule that inhibits the migration of acetamiprid in the soil can be prepared.

[0100] Combining Examples 2, 4, and 5, the differences between them are as follows: in Example 2, the amount of sodium oleate added is 1.5 kg, and the weight ratio of sodium oleate to potassium ferrocyanide is 5:2; in Example 4, the amount of sodium oleate added is 1 kg, and the weight ratio of sodium oleate to potassium ferrocyanide is 5:3; in Example 5, the amount of sodium oleate added is 2 kg, and the weight ratio of sodium oleate to potassium ferrocyanide is 10:3. As can be seen from Table 2, with the increase of sodium oleate addition, the 7-day control effect of the pesticide prepared by water-dispersible granules first increases and then decreases, and the 7-day soil acetamiprid content first increases and then decreases.

[0101] Combining Examples 2, 6, and 7, the differences between the three are as follows: in Example 2, the amount of cassava starch added is 2.5 kg; in Example 6, the amount of cassava starch added is 1 kg; and in Example 7, the amount of cassava starch added is 4 kg. As can be seen from Table 2, with the increase of the amount of cassava starch added, the 7-day control effect of the pesticide prepared by the water-dispersible granules first increases and then decreases, and the 7-day soil acetamiprid content first increases and then decreases.

[0102] Compared to Example 2, Example 8 added humic acid-modified organosilicon powder. As can be seen from Table 2, the addition of humic acid-modified organosilicon powder improved the 7-day control effect of the pesticide, which first increased and then decreased, and reduced the 7-day soil acetamiprid content.

[0103] Combining Examples 8, 9, and 10, the differences between the three are as follows: in Example 8, the amount of humic acid-modified organosilicon powder added is 0.25 kg; in Example 9, the amount of humic acid-modified organosilicon powder added is 0.35 kg; and in Example 10, the amount of humic acid-modified organosilicon powder added is 0.5 kg. As can be seen from Table 2, with the increase of the amount of humic acid-modified organosilicon powder added, the 7-day control effect of the pesticide prepared by the water-dispersible granules first increases and then decreases, and the 7-day soil acetamiprid content first increases and then decreases.

[0104] Compared to Example 2, Comparative Example 1 did not contain chlorothiazoline, and Comparative Example 2 did not contain acetamiprid. As can be seen from Table 2, the combined use of chlorothiazoline and acetamiprid effectively improved the 7-day control effect of the pesticide, first increasing and then decreasing, and reduced the 7-day soil acetamiprid content.

[0105] Compared to Example 2, Comparative Example 3 did not add sodium oleate. As can be seen from Table 2, the addition of sodium oleate improved the 7-day control effect of the pesticide, which first increased and then decreased, and reduced the soil acetamiprid content at 2 days and 7 days.

[0106] Compared to Example 2, Comparative Example 4 did not add potassium ferrocyanide. As can be seen from Table 2, the addition of potassium ferrocyanide improved the 7-day control effect of the pesticide, which first increased and then decreased, and reduced the soil acetamiprid content at 2 days and 7 days.

[0107] Compared to Example 2, Comparative Example 5 did not add cassava starch. As can be seen from Table 2, the addition of cassava starch improved the 7-day control effect of the pesticide, first increasing and then decreasing it, and reduced the soil acetamiprid content at 2 days and 7 days.

[0108] Compared to Example 2, Comparative Example 6 did not add activated carbon powder. As can be seen from Table 2, the addition of activated carbon powder improved the 7-day control effect of the pesticide, which first increased and then decreased, and reduced the soil acetamiprid content at 2 days and 7 days.

[0109] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A chlorothalonil · pyridalyl water dispersible granule, characterized by, The raw materials include the following weight parts: chlorothalonil 40-50 parts; nitenpyram 15-25 parts; dispersing agent 8-12 parts; emulsifying agent 3-7 parts; synergist 0.5-1 part; mineral oil 3-5 parts; anti-caking agent 3-5.5 parts; cassava starch 2-8 parts; activated carbon powder 5.5-8 parts; the anti-caking agent includes sodium oleate and potassium ferrocyanide, the weight ratio of the sodium oleate to the potassium ferrocyanide is (6-8):3, the dispersing agent is selected from the dispersing agent in the aqueous solution in an acid state, the dispersing agent is selected from sodium hexametaphosphate, the emulsifying agent is selected from sodium dodecyl sulfate, the activated carbon powder is selected from wooden activated carbon powder, the synergist is selected from humic acid modified organic silicon powder, the preparation of the humic acid modified organic silicon powder includes the following steps: placing the organic silicon solution and the dried humic acid in a sealed container, stirring at 80-90 DEG C for 20-30 min, taking out and baking at 110-130 DEG C for 2-4 h, grinding and sieving to obtain.

2. The method of producing the chlorothalonil • nitenpyram water dispersible granules according to claim 1, characterized by, The method includes the following steps: S1, uniformly mixing the raw materials according to the proportioning; S2, granulating after airflow crushing, drying and sieving to obtain the water dispersible granules.

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