Microcapsule containing abamectin and fluopyram, suspending agent and preparation method and application thereof

Abstract

The invention discloses a microcapsule containing abamectin and fluopyram, a suspending agent and a preparation method and application of the microcapsule and the suspending agent, and belongs to the technical field of pesticide preparations. The invention provides a microcapsule containing abamectin and fluopyram. The microcapsule contains an active compound and a stabilizer, the active compound is prepared from abamectin and fluopyram; the stabilizing agent is prepared from dimethyl phthalate, acetyl tri-n-butyl citrate and dioctyl phthalate; the median particle size D50 of the microcapsule is 0.6 to 5.0 [mu] m, and the maximum particle size D90 of the microcapsule is 1.0 to 15.0 [mu] m; based on the micro-capsule, the invention also provides a micro-capsule suspending agent containing the micro-capsule containing abamectin and fluopyram and a preparation method of the micro-capsule suspending agent. The microcapsule suspending agent has the persistence of the active ingredients and the mobility of the microcapsules in soil during application, has a certain release amount near the depth of plant roots in the soil, and is expected to become a more effective compound pesticide preparation for preventing and treating plant root diseases.

Description

Technical Field

[0001] The present invention belongs to the technical field of pesticide formulations, and more specifically, relates to a microcapsule, suspension agent containing abamectin and fluopyram, and a preparation method and application thereof. Background Art

[0002] Abamectin is a type of sixteen-membered macrolide compound with insecticidal, acaricidal, and nematicidal activities, which was first developed by Satoshi Ōmura of Kitasato University in Japan and Merck & Co., Inc. in the United States, and is produced by fermentation of Streptomyces avermitilis. Abamectin kills insects by stimulating the release of γ-aminobutyric acid. Experiments have shown that abamectin has high activity against plant nematodes such as root-knot nematodes, root-lesion nematodes, cyst nematodes, stem nematodes, and pine wood nematodes, and has good control effects. Abamectin has the characteristics of broad spectrum, high efficiency, low toxicity, low residue, and environmental friendliness. Currently, abamectin mainly exists in traditional formulations such as emulsifiable concentrates and microemulsions. However, after the application of these formulations of abamectin, it will not move to the roots of plants, and it is adsorbed by the soil and decomposed by microorganisms, with a short effective period. Therefore, there is no cumulative effect in the environment, so the use effect of existing abamectin agents in the field is not ideal. There are reports in the prior art that abamectin is encapsulated in microcapsules, which to a certain extent improves the effective period of abamectin. However, since the plant lesions of nematodes are located at the roots of plants, the prior art has not paid attention to whether abamectin can actually reach the root lesions of plants in the soil to maximize the efficacy and control nematodes.

[0003] Fluopyram is a nematicide with a brand-new mechanism of action, belonging to the class of succinate dehydrogenase inhibitors (SDHIs), and has strong nematicidal activity. Its mechanism of action: inhibits the activity of the target succinate dehydrogenase, thereby interfering with its respiratory function.

[0004] The rational compounding or mixing of insecticidal active ingredients has positive characteristics such as expanding the insecticidal spectrum, improving the control effect, extending the suitable application period, reducing the dosage of pesticides, reducing phytotoxicity, reducing residues, and delaying the occurrence and development of pest drug resistance and resistance. Therefore, the compounding or mixing of insecticides is one of the methods to improve the above effects. The patent document with the Chinese patent application publication number CN104585190A discloses a composition for killing nematodes by compounding abamectin and fluopyram. At a specific ratio of abamectin and fluopyram, it has good toxicity effects under indoor conditions, and the field efficacy control effect on cucumber root-knot nematodes is better than that of abamectin or fluopyram alone. Although the prior art obtains a specific ratio of abamectin or fluopyram with a synergistic effect through the optimization of the ratio of the two, however, its active ingredients are still directly exposed to the soil body and adsorbed by the soil body after application, making it difficult to truly improve the effective period of the active ingredients and difficult to reach the root lesions of plants.

[0005] The patent document with the Chinese patent application publication number CN110150275A discloses a microcapsule suspension - suspension agent containing abamectin and fluxapyroxad. This microcapsule suspension - suspension agent actually prepares abamectin microcapsule suspension by encapsulating abamectin in microcapsules, and then mixes it with the fluxapyroxad suspension that is not encapsulated in microcapsules to obtain the abamectin · fluxapyroxad microcapsule suspension - suspension agent. That is to say, in this prior art, abamectin is encapsulated in microcapsules, while fluxapyroxad remains outside the microcapsules. After applying this abamectin · fluxapyroxad microcapsule suspension - suspension agent, since abamectin is encapsulated by the microcapsules, it will not be directly adsorbed by the upper soil layer. The microcapsules have a certain mobility in the soil, and during the movement, the microcapsules gradually break their walls to release abamectin, avoiding the inactivation of abamectin due to direct exposure to the external environment such as sunlight and soil pH during actual use, and effectively extending the effective period of abamectin. However, this prior art only solves the problem of the persistence of abamectin. After application, fluxapyroxad is still distributed in the upper layer of the soil. Affected by the external environment and the decomposition of microorganisms, it is difficult to reach the root lesion site, which affects its efficacy. In this prior art, fluxapyroxad is not encapsulated in the microcapsules either, because the solubility of the fluxapyroxad technical material is poor. Although the patent document with the Chinese patent application publication number CN114557342A also prepares fluxapyroxad microcapsules, the solvent used to dissolve fluxapyroxad is xylene, which is toxic and not environmentally friendly. This solution is somewhat contrary to the requirements of green environmental protection. Therefore, the prior art has not achieved dissolving the fluxapyroxad technical material with a non - toxic and green solvent and obtaining spherical microcapsules. At the same time, although these two prior arts respectively encapsulate abamectin and fluxapyroxad in microcapsules to solve the persistence problem of a single active ingredient, they also do not pay attention to the problem of whether the active ingredients can actually reach the root lesions of plants in the soil to maximize the efficacy and control nematodes. Summary of the Invention

[0006] 1. Problems to be Solved

[0007] One of the purposes of the present invention is to provide a microcapsule containing abamectin and fluxapyroxad, which dissolves and encapsulates both abamectin and fluxapyroxad in the microcapsules, so that the release rates of the two technical materials in the microcapsules are basically the same, and during the release process, they are both released efficiently and uniformly according to the preset proportion of the technical materials. Moreover, the particle size and the toughness of the capsule wall of the microcapsule make the microcapsule have good mobility after being applied to the soil surface, and can ensure that some active ingredients reach the root lesions of plants at a specific depth in the soil and then slowly release the technical materials, with high utilization rate and long effective period of the technical materials.

[0008] For the above purposes, the present invention further provides microcapsules containing abamectin and fluxapyroxad in powder form (such as lyophilized powder form). Microcapsules of this form are different from the microcapsule suspension with a fixed solid content in the prior art, can be prepared as needed, and the solid content of the microcapsules can be adjusted according to actual requirements. In production and sales, due to the better stability of the powder (such as lyophilized powder), the microcapsule powder is more conducive to storage, transportation, various forms of circulation, and the protection of thermosensitive components.

[0009] The second object of the present invention is to provide a microcapsule suspension containing abamectin and fluxapyroxad. In the abamectin and fluxapyroxad microcapsule suspension, there are microcapsules containing abamectin and fluxapyroxad dispersed in a specific percentage content. The microcapsules are evenly dispersed, do not agglomerate, and are not easily broken, with good storage stability. In the soil application environment, the technical performance of the active ingredient encapsulated by the microcapsules in the soil is good, the utilization rate of the active ingredient is high, and the long-lasting period is long.

[0010] 2. Technical solutions

[0011] To solve the above problems, the technical solutions adopted by the present invention are as follows:

[0012] In the present invention, it is found that the persistence and mobility in soil of abamectin and fluxapyroxad encapsulated in the same microcapsule mainly depend on the dissolution state of the technical materials in the microcapsule, the toughness of the microcapsule wall, and the microcapsule size. If the solubility of the technical materials in the microcapsule is poor, in addition to the low encapsulation rate during microcapsule preparation resulting in loss of active ingredients, when the microcapsules are applied to the soil, the capsule wall is under the dual pressure of the external soil and the internal solid, and there are also problems such as the capsule wall being prone to breakage during the release process and the technical materials existing in solid form in the soil after release and being difficult to exert their efficacy. When the microcapsules are applied to the soil, if the capsule wall has poor toughness or is in an environment containing crystalline substances, the encapsulated technical materials are very easy to release and there is an easy burst release of the technical materials, resulting in most of the technical materials floating on the soil surface and being difficult to move to the lesion location at the plant roots. When the microcapsule size is too large, there will also be problems of burst release and the technical materials floating on the soil surface and being difficult to move to the lesion location at the plant roots. If the microcapsule size is too small, there will be problems such as the microcapsules being difficult to break or moving too deep and the technical materials being difficult to release near the root lesions. Therefore, balancing the stabilizer for dissolving the technical materials, the toughness of the microcapsule wall, and the size is the key to achieving the persistence of the technical materials and their mobility in the soil. At the same time, the dissolution state of the technical materials in the microcapsule and the toughness of the microcapsule wall are affected by the dissolution characteristics of the solvent for the technical materials and the capsule wall. We hope that the solvent has good solubility for the technical materials and can also maintain support for the toughness of the microcapsule wall. Coupled with the control of the microcapsule particle size, the persistence and mobility of the microcapsules can be ensured. On this basis, through research, the present invention has found a stabilizer group (solvent group) that can simultaneously allow the persistence and mobility of the technical materials for dissolving the technical materials in the microcapsule and stabilizing the capsule wall. Under the stabilization of this stabilizer group, microcapsules of a specific size containing both abamectin and fluxapyroxad are formed to achieve both the persistence of the active ingredients and the mobility of the microcapsules in the soil to achieve the purpose of preventing and controlling plant root diseases.

[0013] [Microcapsules Containing Abamectin and Fluxapyroxad]

[0014] Based on this, in the first aspect of the present invention, there is provided a microcapsule containing abamectin and fluxapyroxad, and the microcapsule contains a technical material and a stabilizer;

[0015] The technical material contains a first active ingredient and a second active ingredient; the first active ingredient contains abamectin, and the second active ingredient contains fluxapyroxad;

[0016] The stabilizer contains dimethyl phthalate, tributyl acetylcitrate, and dioctyl phthalate;

[0017] The median particle size D50 of the microcapsule is 0.6 - 5.0 μm; preferably 0.8 - 4.0 μm; more preferably 1.0 - 3.0 μm; most preferably 1.0 - 2.0 μm;

[0018] The maximum particle size D90 of the microcapsule is 1.0 to 15.0 μm, preferably 1.2 to 12.0 μm, more preferably 2.0 to 6.0 μm, and most preferably 2.5 to 5.0 μm.

[0019] For example, it is preferred that the median particle size D50 of the microcapsule is 0.6-5.0 μm, and the maximum particle size D90 is 1.0-15.0 μm; or it is preferred that the median particle size D50 of the microcapsule is 0.8-4.0 μm, and the maximum particle size D90 is 1.2-12.0 μm; or it is preferred that the median particle size D50 of the microcapsule is 1.0-3.0 μm, and the maximum particle size D90 is 2.0-6.0 μm; or it is preferred that the median particle size D50 of the microcapsule is 1.0-2.0 μm, and the maximum particle size D90 is 2.5-5.0 μm.

[0020] The technical drug referred to in the present invention may also be referred to as an active ingredient. Specifically, it refers to two substances, avermectin and fluopyram. If the amount of the technical drug or active ingredient is involved, it refers to the total amount of the two substances, avermectin and fluopyram.

[0021] Natural avermectin contains 8 components, namely avermectin A 1a , A 2a , B 1a , B 2a , A 1b , A 2b , B 1b and B 2b ; The avermectins referred to in the present invention include avermectin A 1a , A 2a , B 1a , B 2a , A 1b , A 2b , B 1b or B 2b Any one of the above, or any combination of any two or more in any proportion, such as avermectin B 1a +B 1b , where B 1a Not less than 90%, B 1b Not more than 5%, also contains other isomers of avermectin that may be present.

[0022] Fluopyram, also known as fluopyram, has a CAS number of 658066-35-4 and the structural formula is as follows:

[0023]

[0024] In the present invention, the stabilizer can also be referred to as a solvent. Specifically, it refers to dimethyl phthalate, tributyl acetylcitrate, and dioctyl phthalate.

[0025] Dimethyl phthalate has a CAS number of 131-11-3 and its structural formula is as follows:

[0026]

[0027] Tributyl acetylcitrate has a CAS number of 195511-54-7 and its structural formula is as follows:

[0028]

[0029] Dioctyl phthalate has a CAS number of 117-81-7 and its structural formula is as follows:

[0030]

[0031] It should be noted that although the compound structures in the present invention do not specifically describe chirality, those skilled in the art should recognize that there may be stereochemical configurations in these chemical structures. The names of all compounds involved in the present invention refer to all reasonable and all possible stereochemical configurations and their combinations of the compound.

[0032] In addition, it should be noted that the stabilizer in the present invention has the functions of dissolving the original drug and stabilizing the microcapsule wall, so it can also be called a solvent. Among the stabilizers, dimethyl phthalate, tributyl acetylcitrate, and dioctyl phthalate all have a certain dissolving effect on abamectin and fluxapyroxad; among them, dioctyl phthalate also supports and stabilizes the toughness of the microcapsule wall of the microcapsule containing urea groups, making the microcapsule wall have a certain toughness, maintaining the thermal storage stability and cold storage stability of the microcapsule, and making the wall have a certain strength, so as to achieve the purpose of slow release of the original drug. At the same time, combined with the particle size characteristics of the microcapsule, the purpose of releasing the microcapsule at a specific depth under the soil body can be achieved. During the preparation of the microcapsule, the ratio and dosage of dimethyl phthalate, tributyl acetylcitrate, and dioctyl phthalate can be adjusted according to the percentage content of the original drugs abamectin and fluxapyroxad. For example, when the proportion of abamectin in the original drug is relatively high, the proportion of dioctyl phthalate in the solvent (stabilizer) can be appropriately increased; when the proportion of fluxapyroxad in the original drug is relatively high, the proportion of tributyl acetylcitrate and dioctyl phthalate in the solvent (stabilizer) can be appropriately increased; in addition, from the perspective of the toughness of the microcapsule wall, in the mixed solvent of dimethyl phthalate, tributyl acetylcitrate, and dioctyl phthalate, the weight percentage of dioctyl phthalate in the mixed solvent should not be less than 10%, but from the perspective of cost, the weight percentage of dioctyl phthalate in the mixed solvent is preferably not more than 35%. At the same time, as a general principle, when preparing the microcapsule, the amount of the solvent (stabilizer) used to dissolve the original drug should generally not be higher than 4 times the content of the original drug, preferably not higher than 3 times the content of the original drug. When the amount of the solvent is too high, it is easy to cause a decrease in the coating rate of the original drug; the amount of the solvent (stabilizer) used to dissolve the original drug should be based on the standard of being able to completely dissolve the original drug, or the amount of the solvent (stabilizer) is slightly higher than the amount of the solvent (stabilizer) that can completely dissolve the original drug, such as more than 10% higher.

[0033] The median particle size and the maximum particle size of the microcapsule are measured by the following method:

[0034] Using a Bettersize wet laser particle size analyzer (model BT-2000), 0.5 g of microcapsules were dispersed in 50 mL of water. The circulation and ultrasound were turned on, and the median particle size and maximum particle size of the microcapsules were measured. As is well known to those skilled in the art, for the laser method of detecting and analyzing particle size, even when using the same laser particle size analyzer and measurement conditions, the detection of different batches of samples will result in slight differences in the particle size distribution behavior, thus leading to slight differences in the measurement results, which are generally acceptable to those skilled in the art. Those skilled in the art know that under the same instrument and fixed test conditions, although theoretically the particle size distribution behavior of particles will be relatively fixed, in fact, it is only relatively fixed within a certain range; for example, for the same batch of samples, under the laser particle size analyzer and measurement conditions specified in the present invention, after multiple measurements, theoretically the size of the maximum particle size D90 should be 15 μm, but the actual test results are 13 μm or 14 μm or 16 μm or 17 μm, etc. These different results should also be regarded as the protection scope of the present invention.

[0035] In the present invention, the particle size tests were all carried out using a Bettersize 2000 laser particle size analyzer, and the specific measurement conditions are as follows:

[0036] Test range: 0.02 μm - 2000 μm;

[0037] Light source: single beam double lens;

[0038] Test method: wet method;

[0039] Sample concentration: 0.5‰ - 1%;

[0040] Scanning speed: 2 - 3 min / time.

[0041] When the microcapsules are in a liquid medium (for example, forming a suspending agent), they are converted to contain 1 g of microcapsules according to their solid content, and the total dispersion medium is kept at 50 mL, and then the above measurements are carried out.

[0042] Compounds such as abamectin, fluopyram, dimethyl phthalate, tributyl acetyl citrate, and dioctyl phthalate can be determined by conventional chemical characterization means, such as nuclear magnetic resonance, mass spectrometry, high performance liquid chromatography (HPLC), liquid chromatography - mass spectrometry (HPLC - MS), gas chromatography - mass spectrometry, etc. Preferably, HPLC or HPLC - MS is used.

[0043] Preferably, the wall of the microcapsule contains a ureido (-NH-CO-NH-) group. The ureido (-NH-CO-NH-) group in the microcapsule wall is generally formed by reacting an isocyanate group (-NCO) with an amino group (-NH 2) It is obtained by reaction. The ureido group can be determined by conventional chemical characterization means, such as Fourier transform infrared spectroscopy (FT-IR) or carbon-13 solid nuclear magnetic resonance spectroscopy ( 13 C CP / MAS NMR). For example, test the Fourier transform infrared spectroscopy (FT-IR) of the microcapsules with intact or disrupted capsule walls; in the infrared spectrum, there is a peak in the range of 2200-2500 cm -1 , which is attributed to the C=O vibration peak in the ureido group (-NH-CO-NH-). Generally, the infrared peak of the C=O vibration in the ureido group (-NH-CO-NH-) may have slight differences due to the differences in the structures of the starting compounds. For example, it is located in the range of 2200-2250 cm -1 , or 2250-2300 cm -1 , 2300-2350 cm -1 , 2350-2400 cm -1 , 2400-2450 cm -1 , or 2450-2500 cm -1 , but generally does not exceed the range of 2200-2500 cm -1 . Again, for example, test the carbon-13 solid nuclear magnetic resonance spectroscopy ( 13 C CP / MAS NMR) of the microcapsules with intact or disrupted capsule walls, which has a characteristic signal peak at 160±15 ppm, preferably at 160±10 ppm. This characteristic signal peak is the characteristic signal peak of the C in the C=O group of the ureido unit. It should be noted that the samples used for Fourier transform infrared spectroscopy (FT-IR) or carbon-13 solid nuclear magnetic resonance spectroscopy ( 13 C CP / MAS NMR) determination should be dried samples.

[0044] As a preference of any technical solution of the first aspect of the present invention, the capsule wall of the microcapsule is obtained by reacting raw materials including isocyanate as an oily wall material and polyamine as an aqueous wall material. The -NCO in the isocyanate reacts with the -NH 2 in the polyamine to form the -NH-CO-NH- group.

[0045] It is well known in the art that the isocyanate can be selected from: IPDI (isophorone diisocyanate), TDI (toluene diisocyanate), HDI (hexamethylene diisocyanate), H12MDI (4,4'-dicyclohexylmethane diisocyanate), MDI (diphenylmethane diisocyanate), etc., and the polyamine can be selected from diethylenetriamine, triethylenetetramine, ethylenediamine, hexamethylenetetramine, isophoronediamine, etc. The raw materials can be selected according to the requirements of the sustained release effect, mobility, and stability of the desired microcapsules. For example, MDI reacts with ethylenediamine to form the wall of the microcapsule, or MDI reacts with hexamethylenediamine to form the wall of the microcapsule, or MDI reacts with triethylenetetramine to form the wall of the microcapsule. Preferably, the amount of amino groups (-NH 2 ) in the polyamine is greater than the amount of isocyanate groups (-NCO) in the isocyanate.

[0046] Generally, in the process of preparing the microcapsules, the amount of -NH 2 in the aqueous wall material should not be lower than the amount of -NCO in the oily wall material. Preferably, the amount of -NH 2 in the aqueous wall material is slightly higher than the amount of -NCO in the oily wall material. For example, compared with the amount of -NCO in the oily wall material, the amount of -NH 2 in the aqueous wall material is 5% - 20% more than the amount of -NCO in the oily wall material. Or in some cases, compared with the mass of the oily wall material, the amount of the aqueous wall material is 5% - 20% more than the mass of the oily wall material, so that the oily wall material can fully react.

[0047] In the process of preparing the microcapsules, to ensure the coating rate of the original drug and the thickness and toughness of the wall of the microcapsule, based on the amount of the original drug, the amount of the oily wall material is generally not lower than 20% of the total mass of the original drug, preferably not lower than 30% of the total mass of the original drug. As the amount of the original drug increases, the amount of the oily wall material should also increase. However, the amount of the oily wall material is not the more the better. Excessive amounts of the oily wall material and the aqueous wall material will also cause the wall of the microcapsule to be too thick or empty microcapsules to appear. Generally, the amount of the oily wall material is not higher than 60% of the total mass of the original drug, and preferably, not higher than 50% of the total mass of the original drug.

[0048] As a preference of any technical solution of the first aspect of the present invention, the content of abamectin in the microcapsules is 0.05 - 0.20 g / g.

[0049] As a preference of any technical solution of the first aspect of the present invention, the content of fluopyram in the microcapsules is 0.10 - 0.30 g / g.

[0050] It should be noted that due to the influence of factors such as the solubility of abamectin and fluxapyroxad technical, the dosage of stabilizer, and the requirements for the final release and mobility of the microcapsules in the soil, within the above content range of the technical, microcapsules with better persistence and mobility in the soil can be comprehensively obtained.

[0051] As a preference of any technical solution of the first aspect of the present invention, the content (by weight) ratio of the first active ingredient to the second active ingredient is A:B, wherein,

[0052] The A can be selected from any one of the following numerical ranges or any numerical value: (0.1 - 20), (0.5 - 20), (1 - 20), (3 - 20), (4 - 20), (5 - 20), (7 - 20), (9 - 20), (10 - 20), (12 - 20), (14 - 20), (16 - 20), (0.1 - 15), (0.5 - 15), (1 - 15), (3 - 15), (4 - 15), (5 - 15), (7 - 15), (9 - 15), (10 - 15), (12 - 15), (14 - 15), (0.1 - 10), (0.5 - 10), (1 - 10), (3 - 10), (4 - 10), (5 - 10), (7 - 10), (9 - 10), (0.1 - 8), (0.5 - 8), (1 - 8), (3 - 8), (4 - 8), (5 - 8), (7 - 8), (0.1 - 7), (0.5 - 7), (1 - 7), (3 - 7), (4 - 7), (5 - 7), (0.1 - 3), (0.5 - 3), (1 - 3), 1, 2, 3, 4, 5, 6, 7, 8, 9, 10;

[0053] B can be selected from any one of the following numerical ranges or any numerical value: (0.1 - 20), (0.5 - 20), (1 - 20), (3 - 20), (4 - 20), (5 - 20), (7 - 20), (9 - 20), (10 - 20), (12 - 20), (14 - 20), (16 - 20), (0.1 - 15), (0.5 - 15), (1 - 15), (3 - 15), (4 - 15), (5 - 15), (7 - 15), (9 - 15), (10 - 15), (12 - 15), (14 - 15), (0.1 - 10), (0.5 - 10), (1 - 10), (3 - 10), (4 - 10), (5 - 10), (7 - 10), (9 - 10), (0.1 - 8), (0.5 - 8), (1 - 8), (3 - 8), (4 - 8), (5 - 8), (7 - 8), (0.1 - 7), (0.5 - 7), (1 - 7), (3 - 7), (4 - 7), (5 - 7), (0.1 - 3), (0.5 - 3), (1 - 3), 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.

[0054] For example, the weight ratio of abamectin to fluxapyroxad in the microcapsules is (1 - 20):(1 - 20). Further, the weight ratio of abamectin to fluxapyroxad in the microcapsules is (1 - 10):(1 - 15). Still further, the weight ratio of abamectin to fluxapyroxad in the microcapsules is (3 - 10):(3 - 15).

[0055] More preferably, the weight ratio of abamectin to fluxapyroxad in the microcapsules is 3:(4 - 12); preferably 3:(5 - 10); most preferably 3:(6 - 9).

[0056] As a preference for any technical solution of the first aspect of the present invention, the content (by weight) ratio of dimethyl phthalate, tributyl acetylcitrate and dioctyl phthalate in the stabilizer is C:D:E, where

[0057] C can be any one of the following value ranges or any value: selected from (1 - 30), (3 - 30), (4 - 30), (5 - 30), (7 - 30), (9 - 30), (10 - 30), (12 - 30), (14 - 30), (16 - 30), (20 - 30), (1 - 25), (3 - 25), (4 - 25), (5 - 25), (7 - 25), (9 - 25), (10 - 25), (12 - 25), (14 - 25), (16 - 25), (20 - 25), (1 - 20), (3 - 20), (4 - 20), (5 - 20), (7 - 20), (9 - 20), (10 - 20), (12 - 20), (14 - 20), (15 - 20), (16 - 20), (1 - 15), (3 - 15), (4 - 15), (5 - 15), (7 - 15), (9 - 15), (10 - 15), (12 - 15), (14 - 15), (1 - 10), (3 - 10), (4 - 10), (5 - 10), (7 - 10), (9 - 10), (1 - 8), (3 - 8), (4 - 8), (5 - 8), (7 - 8), (1 - 7), (3 - 7), (4 - 7), (5 - 7), (1 - 5), 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20;

[0058] D can be any one of the following value ranges or any value: selected from (1 - 25), (3 - 25), (4 - 25), (5 - 25), (7 - 25), (9 - 25), (10 - 25), (12 - 25), (14 - 25), (16 - 25), (20 - 25), (1 - 20), (3 - 20), (4 - 20), (5 - 20), (7 - 20), (9 - 20), (10 - 20), (12 - 20), (14 - 20), (15 - 20), (16 - 20), (1 - 15), (3 - 15), (4 - 15), (5 - 15), (7 - 15), (9 - 15), (10 - 15), (12 - 15), (14 - 15), (1 - 10), (3 - 10), (4 - 10), (5 - 10), (7 - 10), (9 - 10), (1 - 8), (3 - 8), (4 - 8), (5 - 8), (7 - 8), (1 - 7), (3 - 7), (4 - 7), (5 - 7), (1 - 5), (3 - 5), (1 - 4), (3 - 4), 1, 2, 3, 4, 5, 6, 7, 8, 9, 10;

[0059] E can be any one selected from the following value ranges or any value: (1-25), (3-25), (4-25), (5-25), (7-25), (9-25), (10-25), (12-25), (14-25), (16-25), (20-25), (1-20), (3-20), (4-20), (5-20), (7-20), (9-20), (10-20), (12-20), (14-20), (15-20), (16-20), (1-15), (3-15), (4-15), (5-15), (7-15), (9-15), (10-15), (12-15), (14-15), (1-10), (3-10), (4-10), (5-10), (7-10), (9-10), (1-8), (3-8), (4-8), (5-8), (7-8), (1-7), (3-7), (4-7), (5-7), (1-5), (3-5), (1-4), (3-4), 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.

[0060] For example, the weight ratio of dimethyl phthalate, tributyl acetylcitrate and dioctyl phthalate in the stabilizer is (1-30):(1-25):(1-25). Further, the weight ratio of dimethyl phthalate, tributyl acetylcitrate and dioctyl phthalate in the stabilizer is (1-25):(1-15):(1-15). Still further, the weight ratio of dimethyl phthalate, tributyl acetylcitrate and dioctyl phthalate in the stabilizer is (10-20):(1-10):(1-10).

[0061] As a preference of any technical solution of the first aspect of the present invention, the weight ratio of dimethyl phthalate, tributyl acetylcitrate and dioctyl phthalate in the microcapsule is (1-25):(1-15):1; preferably (1-20):(1-8):1; more preferably (1-10):(1-5):1; most preferably (1-5):(1-4):1.

[0062] As a preferred solution of the technical solution of the first aspect of the present invention, the second aspect of the present invention provides a microcapsule containing abamectin and fluxapyroxad, and the microcapsule contains abamectin, fluxapyroxad, dimethyl phthalate, tributyl acetylcitrate and dioctyl phthalate;

[0063] The median particle size D50 of the microcapsule is 0.6-5.0 μm; preferably 0.8-4.0 μm; more preferably 1.0-3.0 μm; most preferably 1.0-2.0 μm;

[0064] The maximum particle size D90 of the microcapsules is 1.0 to 15.0 μm; preferably 1.2 to 12.0 μm; more preferably 2.0 to 6.0 μm; most preferably 2.5 to 5.0 μm;

[0065] By weight, the microcapsules contain:

[0066]

[0067] As a preference for any technical solution of the second aspect of the present invention, by weight, the microcapsules contain:

[0068]

[0069] The measurement methods of the microcapsule particle size and the weight percentages of various substances are the same as those described above, and will not be elaborated here.

[0070] Preferably, the wall of the microcapsules contains ureido (-NH-CO-NH-) groups; the ureido (-NH-CO-NH-) groups in the microcapsule wall are generally obtained by the reaction of isocyanate groups (-NCO) with amino groups (-NH 2 ) groups, and the ureido groups can be determined by conventional chemical characterization means, such as Fourier transform infrared spectroscopy (FT-IR) or carbon-13 solid nuclear magnetic resonance spectroscopy ( 13 C CP / MAS NMR). For example, test the Fourier transform infrared spectroscopy (FT-IR) of the microcapsules with undamaged walls or damaged walls; in the infrared spectrum, there is a peak at 2200 - 2500 cm -1 , which belongs to the C=O vibration peak of the ureido group (-NH-CO-NH-). Generally, the infrared peak of the C=O vibration peak in the ureido group (-NH-CO-NH-) will have slight differences due to the differences in the structures of the raw material compounds, such as at 2200 - 2250 cm -1 , or 2250 - 2300 cm -1 , 2300 - 2350 cm -1 , 2350 - 2400 cm -1 , 2400 - 2450 cm -1 , or 2450 - 2500 cm -1 , but generally will not exceed the range of 2200 - 2500 cm -1 . Again, for example, test the carbon-13 solid nuclear magnetic resonance spectroscopy of the microcapsules with undamaged walls or damaged walls ( 13C CP / MAS NMR), has a characteristic signal peak at 160 ± 15 ppm, preferably at 160 ± 10 ppm. This characteristic signal peak is the characteristic signal peak of C in the C=O group of the urea unit. It should be noted that the samples used for Fourier transform infrared spectroscopy (FT-IR) or carbon-13 solid nuclear magnetic resonance spectroscopy ( 13 The samples for C CP / MAS NMR determination should be dried samples.

[0071] As a preference of any technical solution of the second aspect of the present invention, the wall of the microcapsule is obtained by reacting raw materials including isocyanate as an oily wall material and polyamine as an aqueous wall material. -NCO in the isocyanate reacts with -NH 2 in the polyamine to form -NH-CO-NH- groups.

[0072] It is well known in the art that isocyanates can be selected from: IPDI (isophorone diisocyanate), TDI (toluene diisocyanate), HDI (hexamethylene diisocyanate), H12MDI (4,4'-dicyclohexylmethane diisocyanate), MDI (diphenylmethane diisocyanate), etc., and polyamines can be selected from hexamethylenediamine, triethylenetetramine, ethylenediamine, hexamethylenetetramine, isophoronediamine, etc. The raw materials can be selected according to the requirements of the sustained release property, mobility, and stability of the required microcapsules. For example, MDI reacts with ethylenediamine to form the wall of the microcapsule, or MDI reacts with hexamethylenediamine to form the wall of the microcapsule, or MDI reacts with triethylenetetramine to form the wall of the microcapsule.

[0073] Generally, in the process of preparing the microcapsules, the amount of substance of -NH 2 in the aqueous wall material should not be lower than the amount of substance of -NCO in the oily wall material. Preferably, the amount of substance of -NH 2 in the aqueous wall material is slightly higher than the amount of substance of -NCO in the oily wall material. For example, compared with the amount of substance of -NCO in the oily wall material, the amount of substance of -NH 2 in the aqueous wall material is 5% - 20% more than the amount of substance of -NCO in the oily wall material, or in some cases, compared with the mass of the oily wall material, the amount of the aqueous wall material is 5% - 20% more than the mass of the oily wall material, so that the oily wall material can react fully.

[0074] During the preparation of microcapsules, to ensure the encapsulation rate of the original drug and the thickness and toughness of the capsule wall, the amount of the oily wall material is based on the amount of the original drug. Generally, the dosage of the oily wall material is not less than 20% of the total mass of the original drug, preferably not less than 30% of the total mass of the original drug. As the amount of the original drug increases, the amount of the oily wall material should also increase. However, the dosage of the oily wall material is not the more the better. Excessive amounts of the oily wall material and the aqueous wall material will also cause the capsule wall to be too thick or empty capsules to appear. Usually, the dosage of the oily wall material is not higher than 60% of the total mass of the original drug, preferably not higher than 50% of the total mass of the original drug.

[0075] [Method for preparing microcapsules containing abamectin and fluxapyroxad]

[0076] The third aspect of the present invention provides a method for preparing the microcapsules according to any one of the technical solutions of the first aspect or the second aspect, including:

[0077] Configuration of the aqueous phase component, and the aqueous phase component contains an emulsifying dispersant and an antifoaming agent;

[0078] Configuration of the oil phase component, and the oil phase component contains abamectin and fluxapyroxad dissolved in a mixed solvent of dimethyl phthalate, tributyl acetylcitrate and dioctyl phthalate, and an oily wall material;

[0079] Emulsification, making the configured oil phase component contact and mix with the aqueous phase component and shearing and stirring to obtain an oil-in-water emulsion;

[0080] Reaction of the capsule wall, mixing the aqueous wall material with the emulsified emulsion, and carrying out interfacial polymerization to form the capsule wall to obtain microcapsules containing the active ingredient, continuously accompanied by a stirring operation;

[0081] Heat preservation and curing.

[0082] The schematic diagram of the preparation principle of the microcapsules is as Figure 1 shown.

[0083] At this time, the obtained microcapsules are in a liquid medium, and it can be decided whether to separate the microcapsules in the liquid medium according to actual needs. For example, if a microcapsule suspension is to be prepared, the microcapsules in the liquid medium can be directly used for the next step;

[0084] If a microcapsule powder is to be prepared, the microcapsules in the liquid medium can be dried to obtain dry microcapsules. The drying treatment method can adopt freeze-drying, spray drying and other methods. Specifically, for example:

[0085] i. Separating the microcapsules from the liquid medium by centrifugation

[0086] Centrifuging at 10,000 rpm for 5 min, discarding the supernatant, and washing with deionized water to obtain the microcapsules;

[0087] ii. Then freeze-dry the obtained microcapsules to obtain freeze-dried microcapsule powder.

[0088] By freeze-drying at -70°C for 8 hours, freeze-dried microcapsule powder is obtained.

[0089] As a preference of any technical solution of the third aspect of the present invention, the oily wall material can be isocyanate, and the isocyanate can be selected from: IPDI, TDI, HDI, H12MDI, MDI, etc.

[0090] As a preference of any technical solution of the third aspect of the present invention, the aqueous wall material can be polyamine, and the polyamine can be selected from diamine, triethylenetetramine, ethylenediamine, hexamethylenetetramine, isophoronediamine, etc.

[0091] During the preparation process, microcapsules with different particle size ranges can be obtained by adjusting the shear rate in the emulsification step. For example, when it is desired to obtain microcapsules with a lower median particle size (D50) and a lower maximum particle size (D90), a higher shear rate can be adopted; while when it is desired to obtain microcapsules with a higher median particle size (D50) and a higher maximum particle size (D90), a lower shear rate can be adopted. In the experiment, the shear rate can be specifically adjusted according to this principle to obtain microcapsules with a median particle size (D50) and a maximum particle size (D90) that meet the requirements of the present invention; in the present invention, the shear rate is generally not lower than 10000 rpm, more preferably not lower than 12000 rpm; the shear rate is generally not higher than 17000 rpm, preferably not higher than 15000 rpm.

[0092] As a preference of any technical solution of the third aspect of the present invention, the temperature of heat preservation and curing generally ranges from 60 to 70°C. Considering the improvement of the completion of the polymerization reaction, the temperature of heat preservation and curing can be selected at a relatively low level within the range of 60 to 65°C; considering the improvement of the polymerization reaction rate, the temperature of heat preservation and curing can be selected at a relatively high level within the range of 65 to 70°C.

[0093] As a preference of any technical solution of the third aspect of the present invention, the time of heat preservation and curing generally ranges from 2 to 4 hours. Considering the improvement of the toughness of the microcapsule wall material, the time of heat preservation and curing can range from 2 to 3 hours; considering the improvement of the encapsulation efficiency of the microcapsules, the time of heat preservation and curing can range from 3 to 4 hours.

[0094] The present invention also provides the application of the microcapsules containing abamectin and fluxapyroxad described in any one of the first aspect or the second aspect of the present invention, or the microcapsules containing abamectin and fluxapyroxad prepared by the preparation method described in any one of the third aspect in pesticides.

[0095] Preferably, the microcapsules containing abamectin and fluxapyroxad are used for killing nematodes and / or sterilizing. Since nematodes are usually located at the roots of plants, after the microcapsules of the present invention are applied to the soil body, the microcapsules have good vertical mobility in the soil and are easily able to reach the diseased roots of plants and slowly release the active ingredients. Therefore, the microcapsule suspension of the present invention has a good control and killing effect on nematodes at the roots of plants.

[0096] [Microcapsule Suspension Containing Abamectin and Fluxapyroxad]

[0097] It should be noted that usually in the process of preparing a microcapsule suspension, first a microcapsule liquid containing microcapsules is obtained, and then other reagents are added to the microcapsule liquid to obtain a microcapsule suspension with additional specific properties. For example, when it is required that the microcapsule suspension has improved anti-freezing properties, an anti-freezing agent is added to the microcapsule liquid; when it is required that the microcapsule suspension has enhanced storage stability, a thickening agent is added to the microcapsule liquid; when it is required that the microcapsule suspension has improved anti-corrosion properties, a preservative is added to the microcapsule liquid. Therefore, the preparation of microcapsules can be regarded as a part of the process of preparing a microcapsule suspension, and microcapsules can also be regarded as intermediate products obtained during the process of preparing a microcapsule suspension. Therefore, some definitions, explanations, and the functions and effects of reagents in the microcapsule part and the microcapsule suspension part are generally the same in principle.

[0098] The fourth aspect of the present invention provides a microcapsule suspension containing abamectin and fluxapyroxad, comprising microcapsules dispersed in an aqueous liquid medium, wherein the microcapsules contain the technical material and a stabilizer;

[0099] The technical material contains a first active ingredient and a second active ingredient; the first active ingredient contains abamectin, and the second active ingredient contains fluxapyroxad;

[0100] The stabilizer contains dimethyl phthalate, tributyl acetylcitrate, and dioctyl phthalate;

[0101] The median particle size D50 of the microcapsules is 0.6 - 5.0 μm; preferably 0.8 - 4.0 μm; more preferably 1.0 - 3.0 μm; most preferably 1.0 - 2.0 μm;

[0102] The maximum particle size D90 of the microcapsules is 1.0 - 15.0 μm; preferably 1.2 - 12.0 μm; more preferably 2.0 - 6.0 μm; most preferably 2.5 - 5.0 μm;

[0103] For example, the median particle size D50 of the microcapsules is 0.6 to 5.0 μm, and the maximum particle size D90 is 1.0 to 15.0 μm; or preferably, the median particle size D50 of the microcapsules is 0.8 to 4.0 μm, and the maximum particle size D90 is 1.2 to 12.0 μm; or preferably, the median particle size D50 of the microcapsules is 1.0 to 3.0 μm, and the maximum particle size D90 is 2.0 to 6.0 μm; or preferably, the median particle size D50 of the microcapsules is 1.0 to 2.0 μm, and the maximum particle size D90 is 2.5 to 5.0 μm;

[0104] Among them, the percentage (wt%) of abamectin in the suspending agent is 1 to 20 wt%, and more preferably 1 to 10 wt%;

[0105] The percentage (wt%) of fluxapyroxad in the suspending agent is 1 to 20 wt%, and more preferably 2 to 15 wt%.

[0106] Among them, based on the total weight of the microcapsule suspending agent being 100%.

[0107] As a preference for any technical solution of the fourth aspect of the present invention, the percentage (wt%) of the sum of the weights of abamectin and fluxapyroxad in the suspending agent can be any value taken from any of the following numerical ranges or within the ranges:

[0108] 2 - 40 wt%, 2 - 35 wt%, 2 - 30 wt%, 2 - 25 wt%, 2 - 20 wt%, 2 - 15 wt%, 2 - 10 wt%, 2 - 5 wt%;

[0109] 5 - 40 wt%, 5 - 35 wt%, 5 - 30 wt%, 5 - 25 wt%, 5 - 20 wt%, 5 - 15 wt%, 5 - 10 wt%;

[0110] 10 - 40 wt%, 10 - 35 wt%, 10 - 30 wt%, 10 - 25 wt%, 10 - 20 wt%, 10 - 15 wt%;

[0111] 20 - 40 wt%, 20 - 35 wt%, 20 - 30 wt%, 20 - 25 wt%;

[0112] 30 - 40 wt%, 30 - 35 wt%.

[0113] As a preference for any technical solution of the fourth aspect of the present invention, the percentage (wt%) of the sum of the weights of abamectin and fluxapyroxad in the suspending agent is 5 to 25 wt%, and more preferably 5 to 15 wt%.

[0114] Preferably, for any technical solution of the fourth aspect of the present invention, the percentage by weight (wt%) of abamectin in the suspending agent may be any value taken from any of the following numerical ranges or within the ranges:

[0115] 1 - 20 wt%, 1 - 18 wt%, 1 - 15 wt%, 1 - 12 wt%, 1 - 10 wt%, 1 - 8 wt%, 1 - 7 wt%, 1 - 5 wt%, 1 - 3 wt%, 1 - 2 wt%;

[0116] 2 - 20 wt%, 2 - 18 wt%, 2 - 15 wt%, 2 - 12 wt%, 2 - 10 wt%, 2 - 8 wt%, 2 - 7 wt%, 2 - 5 wt%, 2 - 3 wt%;

[0117] 3 - 20 wt%, 3 - 18 wt%, 3 - 15 wt%, 3 - 12 wt%, 3 - 10 wt%, 3 - 8 wt%, 3 - 7 wt%, 3 - 5 wt%;

[0118] 4 - 20 wt%, 4 - 18 wt%, 4 - 15 wt%, 4 - 12 wt%, 4 - 10 wt%, 4 - 8 wt%, 4 - 7 wt%, 4 - 5 wt%;

[0119] 5 - 20 wt%, 5 - 18 wt%, 5 - 15 wt%, 5 - 12 wt%, 5 - 10 wt%, 5 - 8 wt%, 5 - 7 wt%;

[0120] 7 - 20 wt%, 7 - 18 wt%, 7 - 15 wt%, 7 - 12 wt%, 7 - 10 wt%, 7 - 8 wt%;

[0121] 10 - 20 wt%, 10 - 18 wt%, 10 - 15 wt%, 10 - 12 wt%;

[0122] 12 - 20 wt%, 12 - 18 wt%, 12 - 15 wt%;

[0123] 15 - 20 wt%, 15 - 18 wt%.

[0124] Preferably, for any technical solution of the fourth aspect of the present invention, the percentage by weight (wt%) of fluxapyroxad in the suspending agent may be any value taken from any of the following numerical ranges or within the ranges:

[0125] 1 - 20 wt%, 1 - 18 wt%, 1 - 15 wt%, 1 - 12 wt%, 1 - 10 wt%, 1 - 8 wt%, 1 - 7 wt%, 1 - 5 wt%, 1 - 3 wt%, 1 - 2 wt%;

[0126] 2 - 20 wt%, 2 - 18 wt%, 2 - 15 wt%, 2 - 12 wt%, 2 - 10 wt%, 2 - 8 wt%, 2 - 7 wt%, 2 - 5 wt%, 2 - 3 wt%;

[0127] 3 - 20 wt%, 3 - 18 wt%, 3 - 15 wt%, 3 - 12 wt%, 3 - 10 wt%, 3 - 8 wt%, 3 - 7 wt%, 3 - 5 wt%;

[0128] 4 - 20 wt%, 4 - 18 wt%, 4 - 15 wt%, 4 - 12 wt%, 4 - 10 wt%, 4 - 8 wt%, 4 - 7 wt%, 4 - 5 wt%;

[0129] 5 - 20 wt%, 5 - 18 wt%, 5 - 15 wt%, 5 - 12 wt%, 5 - 10 wt%, 5 - 8 wt%, 5 - 7 wt%;

[0130] 7 - 20 wt%, 7 - 18 wt%, 7 - 15 wt%, 7 - 12 wt%, 7 - 10 wt%, 7 - 8 wt%;

[0131] 10 - 20 wt%, 10 - 18 wt%, 10 - 15 wt%, 10 - 12 wt%;

[0132] 12 - 20 wt%, 12 - 18 wt%, 12 - 15 wt%;

[0133] 15 - 20 wt%, 15 - 18 wt%.

[0134] As a preference of any technical solution of the fourth aspect of the present invention, the weight ratio of abamectin to fluxapyroxad in the suspending agent is 3:(4 - 12); preferably 3:(5 - 10); most preferably 3:(6 - 9).

[0135] As a preference of any technical solution of the fourth aspect of the present invention, the total weight of the stabilizers in the suspending agent generally accounts for 20 - 40 wt%, preferably 20 - 30 wt%. When the content of the stabilizer is low, it is not sufficient to dissolve the technical material, resulting in a low coating rate; considering from the perspective of dissolving the technical material as much as possible, when the content of the technical material increases, the content of the stabilizer also increases accordingly; however, when the content of the stabilizer is too high, oil droplets will appear in the shearing step, which will also cause the problem of low coating rate of the technical material.

[0136] As a preference of any technical solution of the fourth aspect of the present invention, the percentage (wt%) of dioctyl phthalate in the suspending agent can be any value taken from any of the following numerical ranges or within the ranges:

[0137] 2 - 20 wt%, 2 - 18 wt%, 2 - 15 wt%, 2 - 12 wt%, 2 - 10 wt%, 2 - 8 wt%, 2 - 7 wt%, 2 - 5 wt%, 2 - 3 wt%;

[0138] 3 - 20 wt%, 3 - 18 wt%, 3 - 15 wt%, 3 - 12 wt%, 3 - 10 wt%, 3 - 8 wt%, 3 - 7 wt%, 3 - 5 wt%;

[0139] 4 - 20 wt%, 4 - 18 wt%, 4 - 15 wt%, 4 - 12 wt%, 4 - 10 wt%, 4 - 8 wt%, 4 - 7 wt%, 4 - 5 wt%;

[0140] 5 - 20 wt%, 5 - 18 wt%, 5 - 15 wt%, 5 - 12 wt%, 5 - 10 wt%, 5 - 8 wt%, 5 - 7 wt%;

[0141] 7 - 20 wt%, 7 - 18 wt%, 7 - 15 wt%, 7 - 12 wt%, 7 - 10 wt%, 7 - 8 wt%;

[0142] 10 - 20 wt%, 10 - 18 wt%, 10 - 15 wt%, 10 - 12 wt%;

[0143] 12 - 20 wt%, 12 - 18 wt%, 12 - 15 wt%;

[0144] 15 - 20 wt%, 15 - 18 wt%.

[0145] As a preference of any technical solution of the fourth aspect of the present invention, the percentage of dioctyl phthalate in the suspending agent is 3 - 20 wt%; considering from the economic perspective, the percentage of dioctyl phthalate in the suspending agent is 3 - 10 wt%.

[0146] As a preference of any technical solution of the fourth aspect of the present invention, the percentage of dimethyl phthalate in the suspending agent (wt%) can be any value taken from any of the following numerical ranges or within the ranges:

[0147] 5 - 25 wt%, 5 - 20 wt%, 5 - 18 wt%, 5 - 15 wt%, 5 - 12 wt%, 5 - 10 wt%, 5 - 8 wt%, 5 - 7 wt%;

[0148] 7 - 25 wt%, 7 - 20 wt%, 7 - 18 wt%, 7 - 15 wt%, 7 - 12 wt%, 7 - 10 wt%, 7 - 8 wt%;

[0149] 10 - 25 wt%, 10 - 20 wt%, 10 - 18 wt%, 10 - 15 wt%, 10 - 12 wt%;

[0150] 12 - 25 wt%, 12 - 20 wt%, 12 - 18 wt%, 12 - 15 wt%;

[0151] 15 - 25 wt%, 15 - 20 wt%, 15 - 18 wt%.

[0152] 20 - 25 wt%.

[0153] As the preference of any technical solution of the fourth aspect of the present invention, the percentage of dimethyl phthalate in the suspending agent is 10 - 20 wt%; preferably 15 - 20 wt%.

[0154] As the preference of any technical solution of the fourth aspect of the present invention, the percentage of tributyl acetylcitrate in the suspending agent (wt%) can be any value taken from any of the following value ranges or within the range:

[0155] 3 - 12 wt%, 3 - 10 wt%, 3 - 8 wt%, 3 - 7 wt%, 3 - 5 wt%;

[0156] 4 - 12 wt%, 4 - 10 wt%, 4 - 8 wt%, 4 - 7 wt%, 4 - 5 wt%;

[0157] 5 - 12 wt%, 5 - 10 wt%, 5 - 8 wt%, 5 - 7 wt%;

[0158] 7 - 12 wt%, 7 - 10 wt%, 7 - 8 wt%;

[0159] 10 - 12 wt%.

[0160] As the preference of any technical solution of the fourth aspect of the present invention, the percentage of tributyl acetylcitrate in the suspending agent is 3 - 10 wt%; preferably 3 - 8 wt%.

[0161] Preferably, the wall of the microcapsule contains ureido (-NH-CO-NH-) groups. The ureido (-NH-CO-NH-) groups in the wall of the microcapsule are generally obtained by the reaction of isocyanate groups (-NCO) with amino groups (-NH 2 ) and the ureido groups can be determined by conventional chemical characterization means, such as Fourier transform infrared spectroscopy (FT-IR) or carbon-13 solid state nuclear magnetic resonance spectroscopy ( 13 C CP / MAS NMR). For example, test the Fourier transform infrared spectroscopy (FT-IR) of the microcapsules with intact or damaged walls; the infrared spectrum is located at 2200 - 2500 cm -1There is a peak, which belongs to the C=O vibration peak in the ureido group (-NH-CO-NH-). Generally, the infrared peak of the C=O vibration peak in the ureido group (-NH-CO-NH-) will have slight differences due to the differences in the structures of the raw material compounds. For example, it is located at 2200-2250 cm -1 , or 2250-2300 cm -1 , 2300-2350 cm -1 , 2350-2400 cm -1 , 2400-2450 cm -1 , or 2450-2500 cm -1 , but generally it will not exceed the range of 2200-2500 cm -1 . For another example, when testing the carbon-13 solid nuclear magnetic resonance spectrum ( 13 C CP / MAS NMR) of the microcapsules with intact or damaged capsule walls, a characteristic signal peak is present at 160±15 ppm, preferably at 160±10 ppm. This characteristic signal peak is the characteristic signal peak of C in the C=O group of the ureido unit.

[0162] As a preference for any technical solution of the fourth aspect of the present invention, the capsule wall of the microcapsule is obtained by reacting raw materials including an isocyanate as an oily wall material and a polyamine as an aqueous wall material. The -NCO in the isocyanate reacts with the -NH 2 in the polyamine to form an -NH-CO-NH- group.

[0163] It is well known in the art that the isocyanate can be selected from: IPDI (isophorone diisocyanate), TDI (toluene diisocyanate), HDI (hexamethylene diisocyanate), H12MDI (4,4'-dicyclohexylmethane diisocyanate), MDI (diphenylmethane diisocyanate), etc., and the polyamine can be selected from ethylenediamine, triethylenetetramine, ethylenediamine, hexamethylenetetramine, isophorone diamine, etc. The raw materials can be selected according to the requirements of the sustained release effect, mobility, and stability of the required microcapsules. For example, MDI reacts with ethylenediamine to form the capsule wall of the microcapsule, or MDI reacts with hexamethylenediamine to form the capsule wall of the microcapsule, or MDI reacts with triethylenetetramine to form the capsule wall of the microcapsule.

[0164] Generally, in the process of preparing the microcapsule, the amount of substance of -NH 2 in the aqueous wall material should not be lower than the amount of substance of -NCO in the oily wall material. Preferably, the amount of substance of -NH 2 in the aqueous wall material is slightly higher than the amount of substance of -NCO in the oily wall material. For example, compared with the amount of substance of -NCO in the oily wall material, the amount of substance of -NH 2The amount of substance is 5% - 20% more than the amount of -NCO in the oily wall material, or in some cases, the amount of the aqueous wall material is 5% - 20% more than the mass of the oily wall material compared to the mass of the oily wall material, so that the oily wall material can react sufficiently.

[0165] During the preparation of the microcapsules, to ensure the encapsulation rate of the original drug and the thickness and toughness of the capsule wall, based on the amount of the original drug, the amount of the oily wall material generally is not less than 20% of the total mass of the original drug, preferably not less than 30% of the total mass of the original drug. As the amount of the original drug increases, the amount of the oily wall material should also increase. However, the amount of the oily wall material is not the more the better. Excessive amounts of the oily wall material and the aqueous wall material will also cause the capsule wall to be too thick or empty capsules to appear. Generally, the amount of the oily wall material is not higher than 60% of the total mass of the original drug, and preferably, not higher than 50% of the total mass of the original drug.

[0166] As a preference of any technical solution of the fourth aspect of the present invention, during the preparation of the suspending agent, the amount of the oily wall material accounts for 3 - 10%; as the amount of the original drug increases, the amount of the oily wall material should also increase. Preferably, during the preparation of the suspending agent, -NH 2 in the aqueous wall material should be slightly higher than the amount of -NCO in the oily wall material so that the oily wall material can react sufficiently.

[0167] As a preference of any technical solution of the fourth aspect of the present invention, the weight percentage of the microcapsules in the suspending agent is 10 - 70 wt%; further preferably, the weight percentage of the microcapsules in the suspending agent is 20 - 60 wt%; further preferably, the weight percentage of the microcapsules in the suspending agent is 30 - 50 wt%.

[0168] Among them, the weight percentage of the microcapsules in the suspending agent can be obtained by the following method:

[0169] i. Separating the microcapsules from the suspension by centrifugation:

[0170] The microcapsules are obtained by centrifuging at 10000 rpm for 5 min, discarding the supernatant, and washing with deionized water.

[0171] ii. Then freeze-drying the obtained microcapsules to obtain microcapsule freeze-dried powder:

[0172] The microcapsule freeze-dried powder is obtained by freeze-drying at -70°C for 8 h.

[0173] iii. Weighing the weight of the microcapsule freeze-dried powder and calculating the percentage content of the microcapsule freeze-dried powder in the suspension.

[0174] Preferably, for any technical solution of the fourth aspect of the present invention, the suspension further contains an emulsifying dispersant. The emulsifying dispersant can improve the surface tension between phases in the emulsifying system, enhance the emulsifying and dispersing property of the system, and make the system more uniform and stable.

[0175] The emulsifying dispersant is selected from one or more of sodium lignosulfonate or calcium salt, alkylaryl polyoxyethylene polyoxypropylene ether, sodium salt of naphthol sulfonic acid formaldehyde condensate, alkylphenol polyoxyethylene polyoxypropylene ether, styrene maleic anhydride, methylnaphthalene sulfonic acid formaldehyde condensate, castor oil ethylene oxide adduct, alkylphenol polyoxyethylene polyoxypropylene ether, alkyl-diethylene glycol ether-sulfonate, and sodium N-methyl-oleoyl-taurine.

[0176] The emulsifying dispersant accounts for 0.1-10 wt% of the weight of the suspending agent; preferably 0.5-5 wt%.

[0177] Preferably, for any technical solution of the fourth aspect of the present invention, the suspension further contains an antifoaming agent.

[0178] The antifoaming agent is selected from one or more of silicone SAG1522, silicones, silicone oils, fatty alcohols with 8-10 carbon atoms, phosphate esters, saturated fatty acids with 10-20 carbon atoms (such as capric acid), and amides.

[0179] The antifoaming agent accounts for 0.1-10 wt% of the weight of the suspending agent; preferably 0.5-5 wt%.

[0180] Preferably, for any technical solution of the fourth aspect of the present invention, the suspension further contains an antifreezing agent. The antifreezing agent can improve the antifreezing ability of the suspension system and effectively prevent the condensation of ice crystals in the suspension system or the dissolution of the condensed ice crystals in the solution system.

[0181] The antifreezing agent is selected from, but not limited to, one or more of ethanol, isopropanol, ethylene glycol, propylene glycol, glycerol, diethylene glycol, ethylene glycol monobutyl ether, propylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate, and urea.

[0182] The antifreezing agent accounts for 0.1-10 wt% of the weight of the suspending agent; preferably 0.5-5 wt%.

[0183] Preferably, for any technical solution of the fourth aspect of the present invention, the suspension further contains a preservative.

[0184] The preservative is selected from, but not limited to, one or more of sodium benzoate, benzoic acid, Kathon, potassium sorbate, sorbic acid, or sulfites.

[0185] The preservative accounts for 0.1-5 wt% of the weight of the suspending agent; preferably 0.5-2 wt%.

[0186] Preferably, in any technical solution of the fourth aspect of the present invention, the suspension further contains a thickener. The thickener can increase the viscosity of the solution mixing system and enhance the storage stability of the suspension emulsion.

[0187] The thickener is selected from, but not limited to, one or more of clay, rock powder, chalk, quartz, clay, montmorillonite, sodium sulfate, silica, diatomaceous earth, pumice, gypsum, talc, bentonite, kaolin, attapulgite, light calcium carbonate, pottery clay, montmorillonite, magnesium aluminum silicate, activated clay, precipitated silica, ammonium sulfate, benzofuran resin, superphosphate, alumina, calcite, marble, pumice, xanthan gum, arabic gum, gelatin or cyclodextrin.

[0188] The weight percentage (wt%) of the thickener in the suspending agent is 1-20 wt%; preferably 2-10 wt%.

[0189] As a preferred technical solution of the fourth aspect of the present invention, the fifth aspect of the present invention provides a microcapsule suspension containing abamectin and fludioxonil, including microcapsules dispersed in an aqueous liquid medium, and the microcapsules contain abamectin, fludioxonil, dimethyl phthalate, tributyl acetylcitrate and dioctyl phthalate;

[0190] The median particle size D50 of the microcapsules is 0.6-5.0 μm; preferably 0.8-4.0 μm; more preferably 1.0-3.0 μm; most preferably 1.0-2.0 μm;

[0191] The maximum particle size D90 of the microcapsules is 1.0-15.0 μm; preferably 1.2-12.0 μm; more preferably 2.0-6.0 μm; most preferably 2.5-5.0 μm;

[0192] By weight percentage (wt%), the suspending agent contains:

[0193]

[0194] Preferably, in any technical solution of the fifth aspect of the present invention, it further contains:

[0195] Antifreeze 0.1-10 wt%

[0196] Thickener 1-20 wt%.

[0197] Preferably, in any technical solution of the fifth aspect of the present invention, it further contains:

[0198] Preservative 0.1-5 wt%.

[0199] Preferably, by weight percentage (wt%), the suspending agent contains:

[0200]

[0201] Preferably, the wall of the microcapsule contains a ureido (-NH-CO-NH-) group. The ureido (-NH-CO-NH-) group in the microcapsule wall is generally obtained by reacting an isocyanate group (-NCO) with an amino group (-NH 2 ), and the ureido group can be determined by conventional chemical characterization means, such as Fourier transform infrared spectroscopy (FT-IR) or carbon-13 solid nuclear magnetic resonance spectroscopy ( 13 C CP / MAS NMR). For example, test the Fourier transform infrared spectroscopy (FT-IR) of the microcapsules with the wall intact or the wall damaged; in the infrared spectrum, there is a peak at 2200-2500 cm -1 , which belongs to the C=O vibration peak of the ureido group (-NH-CO-NH-). Usually, the infrared peak of the C=O vibration peak in the ureido group (-NH-CO-NH-) will have slight differences due to the differences in the structures of the raw material compounds. For example, it is located at 2200-2250 cm -1 , or 2250-2300 cm -1 , 2300-2350 cm -1 , 2350-2400 cm -1 , 2400-2450 cm -1 , or 2450-2500 cm -1 , but generally does not exceed the range of 2200-2500 cm -1 . For another example, test the carbon-13 solid nuclear magnetic resonance spectroscopy ( 13 C CP / MAS NMR) of the microcapsules with the wall intact or the wall damaged, and there is a characteristic signal peak at 160±15 ppm, preferably at 160±10 ppm. This characteristic signal peak is the characteristic signal peak of the C in the C=O group of the ureido unit.

[0202] Preferably, the wall of the microcapsule is obtained by reacting raw materials including an isocyanate as an oily wall material and a polyamine as an aqueous wall material. The -NCO in the isocyanate reacts with the -NH 2 in the polyamine to form a -NH-CO-NH- group.

[0203] It is well known in the art that the isocyanate can be selected from: IPDI (isophorone diisocyanate), TDI (toluene diisocyanate), HDI (hexamethylene diisocyanate), H12MDI (4,4'-dicyclohexylmethane diisocyanate), MDI (diphenylmethane diisocyanate), etc., and the polyamine can be selected from diethylamine, triethylenetetramine, ethylenediamine, hexamethylenetetramine, isophoronediamine, etc. The raw materials can be selected according to the requirements of the sustained release, mobility, and stability of the desired microcapsules. For example, MDI reacts with ethylenediamine to form the wall of the microcapsules, or MDI reacts with hexamethylenediamine to form the wall of the microcapsules, or MDI reacts with triethylenetetramine to form the wall of the microcapsules.

[0204] Under normal circumstances, in the process of preparing the microcapsules, the amount of substance of -NH 2 in the aqueous wall material should not be lower than the amount of substance of -NCO in the oily wall material. Preferably, the amount of substance of -NH 2 in the aqueous wall material is slightly higher than the amount of substance of -NCO in the oily wall material. For example, compared with the amount of substance of -NCO in the oily wall material, the amount of substance of -NH 2 in the aqueous wall material is 5% - 20% more than the amount of substance of -NCO in the oily wall material. Or in some cases, compared with the mass of the oily wall material, the amount of the aqueous wall material is 5% - 20% more than the mass of the oily wall material, so that the oily wall material can fully react.

[0205] In the process of preparing the microcapsules, to ensure the coating rate of the original drug and the thickness and toughness of the wall of the microcapsules, based on the amount of the original drug, the amount of the oily wall material is generally not lower than 20% of the total mass of the original drug, preferably not lower than 30% of the total mass of the original drug. As the amount of the original drug increases, the amount of the oily wall material should also increase. However, the amount of the oily wall material is not the more the better. Excessive amounts of the oily wall material and the aqueous wall material will also cause the wall of the microcapsules to be too thick or empty microcapsules to appear. Under normal circumstances, the amount of the oily wall material is not higher than 60% of the total mass of the original drug, and preferably, it is not higher than 50% of the total mass of the original drug.

[0206] As a preference of any technical solution of the fifth aspect of the present invention, the weight percentage (wt%) of abamectin and fluxapyroxad in the suspending agent is 5 - 25 wt%, and more preferably 5 - 15 wt%.

[0207] As a preference of any technical solution of the fifth aspect of the present invention, the weight ratio of abamectin to fluxapyroxad in the suspending agent is 3:(4 - 12); preferably 3:(5 - 10); most preferably 3:(6 - 9).

[0208] Preferably, for any technical solution of the fifth aspect of the present invention, the weight percentage of the microcapsules in the suspending agent is 10-70 wt%; more preferably, the weight percentage of the microcapsules in the suspending agent is 20-60 wt%; more preferably, the weight percentage of the microcapsules in the suspending agent is 30-50 wt%.

[0209] Among them, the weight percentage of the microcapsules in the suspending agent can be obtained by the following method:

[0210] i. Separating the microcapsules from the suspension by centrifugation:

[0211] The microcapsules are obtained by centrifuging at 10000 rpm for 5 min, discarding the supernatant, and washing with deionized water;

[0212] ii. Freezing and drying the obtained microcapsules to obtain freeze-dried microcapsule powder:

[0213] The freeze-dried microcapsule powder is obtained by freeze-drying at -70°C for 8 h;

[0214] iii. Weighing the weight of the freeze-dried microcapsule powder and calculating the percentage content of the freeze-dried microcapsule powder in the suspension.

[0215] For the types and weight percentages of the emulsifying dispersant, defoaming agent, antifreeze agent, preservative, and thickening agent, reference can be made to the description in the fourth aspect of the present invention, which will not be elaborated here.

[0216] [Preparation method of abamectin and fluxapyroxad microcapsule suspending agent]

[0217] The sixth aspect of the present invention provides a preparation method of the suspending agent according to any technical solution of the fourth or fifth aspect, including:

[0218] Preparing the aqueous phase components, which contain an emulsifying dispersant and a defoaming agent;

[0219] Preparing the oil phase components, which contain abamectin and fluxapyroxad dissolved in a mixed solvent of dimethyl phthalate, tributyl acetylcitrate, and dioctyl phthalate, as well as an oily wall material;

[0220] Emulsifying, contacting and mixing the prepared oil phase components with the aqueous phase components and shearing and stirring to obtain an oil-in-water emulsion;

[0221] Carrying out a capsule wall reaction, mixing the aqueous wall material with the emulsified emulsion, and carrying out interfacial polymerization to form a capsule wall to obtain microcapsules containing active ingredients, continuously accompanied by a stirring operation;

[0222] Carrying out heat preservation and curing to obtain a microcapsule solution;

[0223] Suspension: Add an antifreeze agent and a thickening agent to the obtained microcapsule solution, and preferably add a preservative to form a microcapsule suspension containing abamectin and fluxapyroxad.

[0224] [Method for preparing a microcapsule suspension using a microcapsule powder containing abamectin and fluxapyroxad]

[0225] The seventh aspect of the present invention provides a method for preparing a microcapsule suspension, including:

[0226] Prepare the microcapsules described in any one of the technical solutions of the first or second aspect of the present invention into microcapsule powders, disperse the microcapsule powders in a liquid medium, add an antifreeze agent and a thickening agent, and add or not add a preservative according to the actual situation (generally add a preservative during commercial use) to form a microcapsule suspension containing abamectin and fluxapyroxad.

[0227] Preferably, the weight percentage of the microcapsules in the suspension is 10 - 70 wt%; further preferably, the weight percentage of the microcapsules in the suspension is 20 - 60 wt%; further preferably, the weight percentage of the microcapsules in the suspension is 30 - 50 wt%.

[0228] The present invention also provides the application of the microcapsule suspension containing abamectin and fluxapyroxad described in any one of the fourth or fifth aspects of the present invention, or the microcapsule suspension containing abamectin and fluxapyroxad prepared by the preparation method described in any one of the third aspects in pesticides.

[0229] Preferably, the microcapsule suspension containing abamectin and fluxapyroxad is used for killing nematodes and / or sterilization. Since nematodes are usually located at the roots of plants, after the microcapsule suspension of the present invention is applied to the soil body, the microcapsules have good vertical mobility in the soil and are easy to reach the diseased roots of plants and slowly release the active ingredients. Therefore, the microcapsule suspension of the present invention has a good control and killing effect on nematodes at the roots of plants.

[0230] [Definition]

[0231] The term "median particle size D50" used in the present invention, where "median particle size" is also called "median diameter" or "average particle size", and "D50" can also be expressed as "Dv50" or "d(0.5)", represents the particle size corresponding to when the cumulative particle size distribution percentage of a sample reaches 50%. Further, its physical meaning is that 50% of the particles are larger than it and 50% of the particles are smaller than it.

[0232] The term "maximum particle size D90" used in the present invention, where "D90" can also be expressed as "Dv90" or "d(0.9)", refers to the particle size corresponding to when the cumulative particle size distribution percentage of a sample reaches 90%. Its physical meaning is that 10% of the particles are larger than it and 90% of the particles are smaller than it.

[0233] The "microcapsule suspension" described in the present invention uses a polymer material as the wall material, and by chemical, physical or physicochemical methods, the active ingredient as the core material is encapsulated to form a microcapsule with a semi-permeable capsule membrane, and they are stably dispersed and suspended in an aqueous medium as the continuous phase at a certain concentration.

[0234] The "slow release" described in the present invention can also be called "controlled release", which refers to the performance that the active ingredient can release the active ingredient at a predetermined speed within a set time and under specific environmental conditions.

[0235] The "persistence" described in the present invention refers to the performance that can continuously release the drug for a long time after application to achieve the purpose of prolonging the drug effect.

[0236] 3. Beneficial effects

[0237] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0238] (1) Generally speaking, the present invention uses a green and environmentally friendly solvent mixture of dimethyl phthalate, tributyl acetylcitrate and dioctyl phthalate that can maintain the toughness of the capsule wall and dissolve abamectin and fluxapyroxad at the same time as a stabilizer to form microcapsules encapsulating the original drugs of abamectin and fluxapyroxad. Combining the particle size characteristics of the microcapsules, the microcapsules have both the persistence of the active ingredient and the mobility of the microcapsules in the soil during application, and have a certain release amount near the depth of the plant roots in the soil, and are expected to become a more effective compound pesticide preparation for preventing and treating plant root diseases.

[0239] (2) The microcapsules encapsulating the original drugs of abamectin and fluxapyroxad of the present invention have good persistence. Examples 1-7 show that abamectin and fluxapyroxad can maintain a relatively uniform release within up to 300 h, and compared with the prior art of the abamectin·fluxapyroxad microcapsule suspension-suspension agent that only encapsulates abamectin, the fluxapyroxad in the present invention also achieves long-term slow release.

[0240] (3) The microcapsules encapsulating the original drugs of abamectin and fluxapyroxad of the present invention, due to the moderate toughness of their capsule walls and appropriate particle size, the capsule walls are not easily broken, and have good mobility in the soil. A certain proportion of the microcapsules can move to a certain depth (9-12 cm) in the soil and then release, ensuring that the microcapsules can have a certain concentration near the depth of the plant roots in the soil and can be effectively used for killing purposes such as nematode diseases in plant roots.

[0241] (4) The microcapsule suspension containing abamectin and fluxapyroxad of the present invention has uniformly dispersed microcapsules that do not agglomerate and are not easily broken, with good cold and heat storage stability. In the soil application environment, both original drugs are encapsulated in the microcapsules. The microcapsules have good mobility in the soil, high utilization rate of the original drugs, long residual period, and can play a therapeutic role in the plant root lesions deep in the soil body. Description of the Drawings

[0242] Figure 1 Schematic diagram for the preparation of the microcapsule suspension of abamectin and fluxapyroxad in the examples;

[0243] Figure 2 SEM image of the microcapsules in the microcapsule suspension of abamectin and fluxapyroxad in Example 1;

[0244] Figure 3 SEM image of the microcapsules in the microcapsule suspension of abamectin and fluxapyroxad in Example 2;

[0245] Figure 4 SEM image of the microcapsules in the microcapsule suspension of abamectin and fluxapyroxad in Example 3;

[0246] Figure 5 SEM image of the microcapsules in the microcapsule suspension of abamectin and fluxapyroxad in Comparative Example 1;

[0247] Figure 6 SEM image of the microcapsules in the microcapsule suspension of abamectin and fluxapyroxad in Comparative Example 2;

[0248] Figure 7 Cumulative release diagram of abamectin in the microcapsules of abamectin and fluxapyroxad in Example 8;

[0249] Figure 8 Cumulative release diagram of fluxapyroxad in the microcapsules of abamectin and fluxapyroxad in Example 8;

[0250] Figure 9 Cumulative release diagram of abamectin and fluxapyroxad in the microcapsules of abamectin and fluxapyroxad prepared in Example 1;

[0251] Figure 10 Infrared spectrum diagram in Example 11, where: a: abamectin + fluxapyroxad original drug; b: abamectin + fluxapyroxad microcapsules; c: blank microcapsules. Detailed Embodiments

[0252] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs; the term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0253] For those not specified in the examples, they are carried out under conventional conditions or conditions recommended by the manufacturer. For reagents or instruments not specified by the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0254] As used herein, the term "about" is used to provide flexibility and imprecision associated with a given term, measurement, or value. One of ordinary skill in the art can readily determine the degree of flexibility for a particular variable.

[0255] Concentrations, amounts, and other numerical data may be presented herein in a range format. It should be understood that such range formats are used merely for convenience and brevity and should be interpreted flexibly as including not only the explicitly recited numerical values as the limits of the range, but also all individual numerical values or sub-ranges subsumed within the stated range as if each numerical value and sub-range were explicitly recited. For example, a numerical range of about 1 to about 4.5 should be interpreted as including not only the explicitly recited limits of 1 to about 4.5, but also the individual numbers (such as 2, 3, 4) and sub-ranges (such as 1 to 3, 2 to 4, etc.). The same principle applies to ranges that recite only one numerical value, such as "less than about 4.5", which should be interpreted as including all of the above values and ranges. In addition, this interpretation should apply regardless of the breadth of the range or feature described.

[0256] Determination method of coating rate in the examples: Weigh 1 g of the microcapsule suspension sample, mix it evenly with 5 mL of 20% ethylene glycol aqueous solution, place it in a 10 mL centrifuge tube, centrifuge at 5000 rmp in a high-speed centrifuge for 6 min, take out the supernatant, and after filtration, use a high-performance liquid chromatograph for determination. The HPLC detection methods for abamectin and fluxapyroxad are as follows:

[0257] HPLC detection conditions for abamectin:

[0258] Mobile phase: methanol: water = 90:10 (v:v); detection wavelength: 250 nm; flow rate: 1.0 mL / min; column temperature: 30 °C.

[0259] HPLC detection conditions for fluxapyroxad:

[0260] Mobile phase: acetonitrile: water = 60:40 (v:v); detection wavelength: 220 nm; flow rate: 1.0 mL / min; column temperature: 30 °C.

[0261] Abamectin coating rate = (1 - concentration detected by liquid chromatography / original abamectin concentration) × 100%

[0262] Fludioxonil coating rate = (1 - concentration detected by liquid chromatography / original fludioxonil concentration) × 100%

[0263] The original abamectin concentration refers to the weight percentage of the original drug abamectin initially added, calculated based on the total amount of the microcapsule suspension being 100%; the original fludioxonil concentration refers to the weight percentage of the original drug fludioxonil initially added, calculated based on the total amount of the microcapsule suspension being 100%.

[0264] Reagents:

[0265]

[0266] Instruments:

[0267]

[0268] The present invention will be further described below in conjunction with specific embodiments.

[0269] Example 1

[0270] In this example, the components and parts by weight of the abamectin and fludioxonil microcapsule liquid are as follows:

[0271]

[0272] The preparation method of the above abamectin and fludioxonil microcapsule liquid is as follows:

[0273] (1) Preparation of the aqueous phase components: Add an emulsifying dispersant and an antifoaming agent to water, mix evenly, and set aside;

[0274] (2) Preparation of the oil phase components: Dissolve abamectin and fludioxonil in dimethyl phthalate, tributyl acetyl citrate, and dioctyl phthalate, add an oily wall material, stir evenly, and set aside;

[0275] (3) At a water bath temperature of 60 °C, under high-speed shearing and stirring at 12000 - 15000 rmp, add (2) to (1), shear to an appropriate particle size to form a stable oil-in-water (O / W) emulsion;

[0276] (4) While stirring, at a water bath temperature of 60 °C, add an aqueous wall material dropwise to the emulsion in (3);

[0277] (5) Heat and keep warm to form capsules, the heating temperature is 65 °C, and the holding time is 3.5 hours to form the abamectin and fludioxonil microcapsule liquid.

[0278] The SEM of the microcapsules is as Figure 2As shown, the microcapsules have a good appearance, being spherical in shape, without any damage, with relatively uniform particle sizes, and the surface of the microcapsules is relatively smooth and dense.

[0279] (6) The microcapsules in the microcapsule liquid can be obtained by taking a part of the microcapsule liquid through the following method:

[0280] i. Separate the microcapsules from the microcapsule liquid by centrifugation:

[0281] Centrifuge at 10,000 rpm for 5 minutes, discard the supernatant, and wash with deionized water to obtain the microcapsules;

[0282] ii. Then lyophilize the obtained microcapsules to obtain microcapsule lyophilized powder:

[0283] Lyophilize at -70 °C for 8 hours to obtain the microcapsule lyophilized powder;

[0284] iii. Weigh the mass of the microcapsule lyophilized powder.

[0285] (7) Add an antifreeze, a preservative, and a thickening agent to the abamectin and fluxapyroxad microcapsules formed in (5), and stir evenly to form an abamectin and fluxapyroxad microcapsule suspension.

[0286] For the abamectin and fluxapyroxad microcapsule suspension prepared by the above preparation method, the components and contents are as follows (calculated based on the total weight of the suspension being 100%, where the oily wall material and the aqueous wall material are the dosages, and this meaning is understood in the examples):

[0287]

[0288] Example 2

[0289] In this example, the components and parts by weight of the abamectin and fluxapyroxad microcapsule liquid are as follows:

[0290]

[0291]

[0292] The preparation method steps (1)-(6) of the above abamectin and fluxapyroxad microcapsule liquid are the same as those in Example 1;

[0293] (7) Add an antifreeze, a preservative, and a thickening agent to the abamectin and fluxapyroxad microcapsules formed in (5), and stir evenly to form an abamectin and fluxapyroxad microcapsule suspension.

[0294] For the abamectin and fluxapyroxad microcapsule suspension prepared by the above preparation method, the components and contents are as follows (calculated based on the total weight of the suspension being 100%):

[0295]

[0296] Example 3

[0297] In this example, the components and parts by weight of the abamectin and fluxapyroxad microcapsule liquid are as follows:

[0298]

[0299] The preparation method steps (1)-(6) of the above abamectin and fluxapyroxad microcapsule liquid are the same as those in Example 1;

[0300] (7) In the abamectin and fluxapyroxad microcapsules formed in (5), add antifreeze, preservative, and thickener, and stir evenly to form an abamectin and fluxapyroxad microcapsule suspension.

[0301] The components and contents of the abamectin and fluxapyroxad microcapsule suspension prepared by the above preparation method are as follows (based on the total weight of the suspension being 100%):

[0302]

[0303]

[0304] Example 4

[0305] In this example, the components and parts by weight of the abamectin and fluxapyroxad microcapsule liquid are as follows:

[0306]

[0307] The preparation method steps (1)-(6) of the above abamectin and fluxapyroxad microcapsule liquid are the same as those in Example 1;

[0308] (7) In the abamectin and fluxapyroxad microcapsules formed in (5), add antifreeze, preservative, and thickener, and stir evenly to form an abamectin and fluxapyroxad microcapsule suspension.

[0309] The components and contents of the abamectin and fluxapyroxad microcapsule suspension prepared by the above preparation method are as follows (based on the total weight of the suspension being 100%):

[0310]

[0311] Example 5

[0312] In this example, the components and parts by weight of the abamectin and fluxapyroxad microcapsule liquid are as follows:

[0313]

[0314] The preparation method steps (1)-(6) of the above abamectin and fluxapyroxad microcapsule liquid are the same as those in Example 1;

[0315] (7) In the avermectin and fluxapyroxad microcapsules formed in (5), an antifreeze agent, a preservative, and a thickening agent are added and stirred evenly to form an avermectin and fluxapyroxad microcapsule suspension.

[0316] For the avermectin and fluxapyroxad microcapsule suspension prepared by the above preparation method, the components and contents are as follows (based on the total weight of the suspension being 100%):

[0317]

[0318] Example 6

[0319] In this example, the components and parts by weight of the avermectin and fluxapyroxad microcapsule liquid are as follows:

[0320]

[0321] The preparation method steps (1)-(6) of the above avermectin and fluxapyroxad microcapsule liquid are the same as those in Example 1;

[0322] (7) In the avermectin and fluxapyroxad microcapsules formed in (5), an antifreeze agent, a preservative, and a thickening agent are added and stirred evenly to form an avermectin and fluxapyroxad microcapsule suspension.

[0323] For the avermectin and fluxapyroxad microcapsule suspension prepared by the above preparation method, the components and contents are as follows (based on the total weight of the suspension being 100%):

[0324]

[0325] Example 7

[0326] In this example, the components and parts by weight of the avermectin and fluxapyroxad microcapsule liquid are as follows:

[0327]

[0328]

[0329] The preparation method steps (1)-(6) of the above avermectin and fluxapyroxad microcapsule liquid are the same as those in Example 1;

[0330] (7) In the avermectin and fluxapyroxad microcapsules formed in (5), an antifreeze agent, a preservative, and a thickening agent are added and stirred evenly to form an avermectin and fluxapyroxad microcapsule suspension.

[0331] For the avermectin and fluxapyroxad microcapsule suspension prepared by the above preparation method, the components and contents are as follows (based on the total weight of the suspension being 100%):

[0332]

[0333] The property parameters of the microcapsules and the microcapsule suspension prepared in Examples 1-7 are shown in Table 1.

[0334] Table 1 Property parameters of the microcapsules and the microcapsule suspension prepared in Examples 1-7

[0335]

[0336] Note: The unit of the abamectin content in the microcapsules, g / g, represents the number of grams of abamectin contained in each gram of the microcapsules. The unit of the fluxapyroxad content in the microcapsules, g / g, represents the number of grams of fluxapyroxad contained in each gram of the microcapsules.

[0337] Comparative Example 1

[0338] Effect of the selection of stabilizer on the microcapsules

[0339] Other conditions were the same as in Example 1, except that: dioctyl phthalate was replaced with solvent oil 150#, and in order to completely dissolve abamectin and fluxapyroxad, the amount of solvent oil was increased by 20% (calculated based on the total weight of the microcapsule suspension being 100%) to obtain microcapsules containing abamectin and fluxapyroxad and the microcapsule suspension. The microcapsule suspension was taken for SEM as Figure 5 shown, and more original drugs were precipitated outside the microcapsule particles.

[0340] As shown in Table 2, when using solvent oil 150# as the solvent to replace dioctyl phthalate, on the one hand, it is necessary to increase the amount of solvent oil to dissolve the original drugs, and on the other hand, the encapsulation rates of abamectin and fluxapyroxad in the obtained microcapsule suspension are relatively low, and the thermal storage stability and cold storage stability of the microcapsule suspension sample in Example 10 are unqualified (Table 7).

[0341] Comparative Example 2

[0342] Effect of the selection of stabilizer on the microcapsules

[0343] Other conditions were the same as in Example 1, except that: dioctyl phthalate was replaced with N-methylpyrrolidone, and the amount used remained unchanged, to obtain microcapsules containing abamectin and fluxapyroxad and the microcapsule suspension. The microcapsule suspension was taken for SEM as Figure 6 shown, and there were more depressions in the capsule wall of the microcapsule particles.

[0344] As shown in Table 2, when N-methylpyrrolidone was used instead of dioctyl phthalate as the solvent, although it had good solubility for the technical material, since N-methylpyrrolidone had a certain solubility for the capsule wall, it was not conducive to maintaining the toughness of the capsule wall. The prepared microcapsule capsule wall collapsed severely, and it also led to low contents of abamectin and fluxapyroxad in the microcapsule suspension. Moreover, the thermal storage stability and cold storage stability of the microcapsule suspension in Example 10 were unqualified (Table 7).

[0345] Comparative Example 3

[0346] Effect of stabilizer selection on microcapsules

[0347] Other conditions were the same as in Example 1, except that: dioctyl phthalate was not added, and the technical material could not be dissolved, resulting in the inability to further prepare microcapsules and microcapsule suspensions.

[0348] Comparative Example 4

[0349] Effect of average microcapsule particle size on microcapsule properties

[0350] Other conditions were the same as in Example 1, except that: step (3) in the preparation method of the abamectin and fluxapyroxad microcapsule liquid was as follows:

[0351] (3) Under high-speed shearing and stirring at 6000 - 8000 rmp, (2) was added to (1) to form a stable oil-in-water (O / W) emulsion.

[0352] Other steps were the same, and microcapsules and microcapsule suspensions containing abamectin and fluxapyroxad were obtained.

[0353] As shown in Table 2, the microcapsules obtained at a shearing speed of 6000 - 8000 rmp had a larger particle size, were prone to sedimentation during storage, and had water separation on the upper layer; moreover, when the microcapsule particle size was large, the release of the technical material was too fast to achieve the purpose of long-acting release (Tables 3 and 4). And when the microcapsule size was relatively large, the thermal storage stability and cold storage stability of the microcapsule suspension in Example 10 were unqualified (Table 7).

[0354] Comparative Example 5

[0355] Effect of average microcapsule particle size on microcapsule properties

[0356] Other conditions were the same as in Example 1, except that: step (3) in the preparation method of the abamectin and fluxapyroxad microcapsule liquid was as follows:

[0357] (3) Under high-speed shearing and stirring at 20000 - 22000 rmp, (2) was added to (1) to form a stable oil-in-water (O / W) emulsion.

[0358] Other steps are the same, and microcapsules containing abamectin and fluxapyroxad and a microcapsule suspension are obtained.

[0359] As shown in Table 2, the microcapsules obtained at a shear rate of 22000 - 25000 rmp have a smaller particle size, and water is prone to separate out at the lower layer during storage; moreover, when the particle size of the microcapsules is small, the release of the technical drug is too slow to achieve the purpose of exerting the drug effect (Tables 3 and 4). And when the microcapsule size is small, the thermal storage stability and cold storage stability of the microcapsule suspension in Example 10 are unqualified (Table 7).

[0360] Property parameters of the microcapsules and microcapsule suspensions prepared in Comparative Examples 1, 2, 4, and 5 in Table 2

[0361]

[0362] Example 8

[0363] Original drug release experiments of the microcapsule suspensions prepared in Examples 1 - 7 and Comparative Examples 1 - 5 (except Comparative Example 3)

[0364] The release behavior of microcapsules in soil was simulated by using microcapsule release kinetics research.

[0365] The dialysis bag method was used to study the microcapsule release kinetics. The purchased dialysis bag (cut-off molecular weight: 8000 - 14000) was cut into small sections about 5 cm long for pretreatment. 1.00 g of the newly prepared microcapsule suspension was accurately weighed and placed in the dialysis bag. The dialysis bag was immersed in a 100 mL conical flask containing 50 mL of release medium. The release medium was 50 / 50 acetonitrile / water (v / v). The release test was carried out at a rotation speed of 100 rpm in a double-layer shaking incubator at 25 ± 2 °C. At different time intervals, an equal amount (1 mL) of the medium outside the dialysis bag was collected, and 1 mL of the acetonitrile / water solution of the release medium was replenished to keep the volume of the release medium always 50 mL. The sampling solution passed through an organic phase microporous filter membrane with a pore size of 0.22 μm. High performance liquid chromatography was used to determine the contents of abamectin and fluxapyroxad in the filtered solution. According to the measurement results, the cumulative release amounts of the two original drugs in the microcapsules were calculated respectively.

[0366] Calculation formula for cumulative release amount:

[0367]

[0368] Among them, Ct represents the concentration of abamectin (fluxapyroxad) in the release medium at time t, mt-act represents the cumulative release amount of abamectin (fluxapyroxad) at time t, v represents the volume of the release medium taken out each time (1 mL in this experiment), and V represents the total volume of the release medium (50 mL in this experiment).

[0369] The cumulative release amount of abamectin over time is as shown in Table 3 below:

[0370] Table 3 Cumulative release amount of avermectin over time

[0371]

[0372]

[0373] The cumulative release curve of avermectin over time is as follows Figure 7 shown. The microcapsule suspensions prepared in Examples 1-7 showed a relatively uniform release state within 312 h. Among them, the release rate from 0 to 192 h was slightly higher than that from 192 to 312 h. There was a phenomenon of burst release during the release of avermectin from the microcapsules prepared in Comparative Example 1 (96-120 h), and the cumulative release amount reached about 70%-80%. The reason for this phenomenon may be that the solvent (stabilizer) for dissolving the original drug had poor solubility, resulting in the easy rupture of the capsule wall and sudden release of the original drug. There was a phenomenon of burst release during the release of avermectin from the microcapsules prepared in Comparative Example 2 (48-168 h). The reason for this phenomenon may be that the solvent (stabilizer) for dissolving the original drug had erosion on the capsule wall, resulting in a thinner capsule wall and easy rupture to release the original drug. The microcapsules prepared in Comparative Example 4 had a larger particle size and a thinner capsule wall, and there was a phenomenon of burst release during the oscillatory release process (48-168 h). The microcapsules prepared in Comparative Example 5 had a smaller particle size, and it was difficult to release the active ingredient.

[0374] The cumulative release amount of fluxapyroxad over time is shown in Table 4 below

[0375] Table 4 Cumulative release amount of fluxapyroxad over time

[0376]

[0377] As Figure 8 shown, the cumulative release curve of fluxapyroxad was relatively similar to that of avermectin. The microcapsule suspensions prepared in Examples 1-7 showed a relatively uniform release state within 312 h. Among them, the release rate from 0 to 192 h was slightly higher than that from 192 to 312 h. There was a phenomenon of burst release during the release of fluxapyroxad from the microcapsules prepared in Comparative Example 1 (96-120 h). The reason for this phenomenon may be that the solvent (stabilizer) for dissolving the original drug had poor solubility, resulting in the easy rupture of the capsule wall and sudden release of the original drug. There was a phenomenon of burst release during the release of fluxapyroxad from the microcapsules prepared in Comparative Example 2 (48-144 h). The reason for this phenomenon may be that the solvent (stabilizer) for dissolving the original drug had erosion on the capsule wall, resulting in a thinner capsule wall and easy rupture to release the original drug; the microcapsules prepared in Comparative Example 4 had a larger particle size and a relatively thinner capsule wall, and there was a phenomenon of burst release during the oscillatory release process (48-144 h). The microcapsules prepared in Comparative Example 5 had a smaller particle size, and it was difficult to release the active ingredient.

[0378] Combined with the cumulative release curves of abamectin and fluxapyroxad, as Figure 9 shown, the cumulative release percentages of abamectin and fluxapyroxad in Example 1 were basically the same within 312 h, that is, they were uniformly and long-acting released basically according to the feeding percentage during coating.

[0379] Example 9

[0380] The mobility experiment of the microcapsule suspension prepared in Examples 1-7 and Comparative Examples 1-5 (except Comparative Example 3) in soil

[0381] To investigate the leaching characteristics of abamectin and fluxapyroxad in soil, a leaching experiment was carried out on the prepared microcapsule suspension by the soil column leaching method. Through the soil column leaching test, the leaching characteristics of the microcapsule suspension prepared in Examples 1-7 and Comparative Examples 1-5 (except Comparative Example 3) in soil were determined. Weigh 720 g of the tested soil passed through a 20-mesh sieve and fill it into the cylindrical PVC plastic pipe to make a soil column with a height of 30 cm. Spread 1 cm thick quartz sand on the surface of the soil column, and add 0.1 mol / L CaCl 2 solution to reach 60% of the saturated water holding capacity. Then, the microcapsule suspension prepared in Examples 1-7 and Comparative Examples 1-5 (except Comparative Example 3) was uniformly dripped into the quartz sand layer at 10 mg / cm 2 a.i., and leached with 0.01 mol / L CaCl 2 solution at a rate of 30 mL / h, and a total of 300 mL of leachate was collected. Each treatment was repeated three times and the average value was taken. After the leaching was completed, the soil column was evenly divided into 10 sections, and the contents of abamectin and fluxapyroxad in each section of the soil and the leachate were measured respectively. The content calculation method is as follows:

[0382]

[0383] In the formula: R i : the proportion of the pesticide content in each section of the soil and the leachate (%); m i : the mass of the pesticide in each section of the soil and the leachate (mg); m o : the total amount of pesticide added (mg).

[0384] The content of abamectin varying with depth is as follows:

[0385] Table 5 The content of abamectin varying with depth

[0386]

[0387] The content of fluxapyroxad varying with depth is as follows:

[0388] Table 6 Content of fluxapyroxad varying with depth

[0389]

[0390] Since the root lesion sites are generally about 10 cm below the soil surface, it is desired that the microcapsules containing the technical material can have a certain release at an appropriate depth below the soil surface. In this experiment, the vertical mobility of the microcapsules in the soil mass was simulated. The results showed that the percentage content of abamectin in the microcapsules prepared in Examples 1-7 reached 4% - 8% near the depth of 9 - 12 cm. Similar to the mobility of abamectin in the soil mass, fluxapyroxad in all 7 examples could reach the depth of 9 - 12 cm, reaching the disease site, and the percentage content reached 3% - 7%. It indicates that the microcapsule samples prepared in Examples 1-7 have good vertical mobility in the soil column. In contrast, after the microcapsules prepared in Comparative Examples 1, 2 and 4 were applied, abamectin and fluxapyroxad were basically concentrated at 0 - 6 cm below the soil surface and could not move vertically, almost distributed in the upper part of the soil, with poor vertical distribution and mobility in the soil. It should be noted that a relatively high content of abamectin and fluxapyroxad was detected in the leachate of Comparative Example 5, which may be due to the fact that the average particle size of the microcapsules was too small, resulting in too good mobility in the soil.

[0391] Example 10

[0392] Storage stability experiment of the microcapsule suspension prepared in Examples 1-7 and Comparative Examples 1-5

[0393] The thermal storage stability was determined according to the method in the National Standard of the People's Republic of China "Determination Method for Thermal Storage Stability of Pesticides", GB / T 19136-2003. Specifically: Use a syringe to inject about 30 mL of the test sample into a clean ampoule bottle (avoiding the test sample contacting the bottleneck), place this ampoule bottle in an ice-salt bath for refrigeration, seal it with a high-temperature flame (avoiding solvent volatilization), and cool it to room temperature and weigh. Place the sealed ampoule bottle in a metal container, and then place the metal container in a constant temperature oven (or constant temperature water bath) at (54 ± 2) °C for 14 d. Take it out, wipe the outside of the ampoule bottle clean and weigh. For the test sample with unchanged mass, complete the inspection of the specified items such as the content of the active ingredient within 24 h.

[0394] The inspection indicators are as follows:

[0395] (1) Macroscopic observation: After 14 d, it is qualified if it can flow, is not pasted, and the water separation is less than 20%;

[0396] (2) Microscopic observation: It is qualified if the microcapsules are not agglomerated and have a good shape;

[0397] (3) Content analysis: It is qualified if the effective content of the technical material is within the range of ±3%;

[0398] (4) Suspension rate analysis: It is qualified if the suspension rate is greater than or equal to 95%;

[0399] The cold storage stability was determined according to the method in the National Standard of the People's Republic of China, "Determination Method for Low Temperature Stability of Pesticides", GB / T 19137-2003. Specifically: Take 80 mL of the test sample and place it in a 100 mL beaker. Cool it to (0 ± 2) °C in a refrigerator, keep it for 1 h, stir it every 15 min for 15 s each time, and observe whether there is any change in appearance. Put the beaker back into the refrigerator and continue to place it at (0 ± 2) °C for 7 d. After 7 d, take out the beaker, restore it to room temperature, and test the sieve analysis, suspension rate or other necessary physical and chemical indexes.

[0400] The inspection indexes are as follows:

[0401] (1) Macroscopic observation: After 7 d, it is qualified if it is flowable, no crystal is separated out, and the water separation is less than 15%;

[0402] (2) Microscopic observation: After microscopic observation, it is qualified if the microcapsules are not agglomerated and have a good shape;

[0403] (3) Content analysis: It is qualified if the effective content of the technical material is within the range of ±3%;

[0404] (4) Suspension rate analysis: It is qualified if the suspension rate is greater than or equal to 95%;

[0405] Table 7 Thermal storage stability and cold storage stability of the microcapsule suspension in Examples 1-7 and Comparative Examples 1, 2, 4 and 5

[0406]

[0407] Example 11

[0408] Fourier transform infrared spectroscopy detection

[0409] Method: After pressing the sample into a KBr tablet, the structure of the sample to be tested was identified by infrared spectroscopy. Weigh 2 mg of the dried sample to be tested, add KBr, grind it into powder, then press it into a tablet, and scan it at a wavelength of 4000-450 cm in the Fourier transform infrared spectrum to obtain the infrared spectrum. -1 Wavelength for scanning to obtain the infrared spectrum.

[0410] Figure 10 Curves a-c respectively represent the infrared spectra of abamectin + fluxapyroxad technical material (with the same ratio as in Example 1), abamectin + fluxapyroxad microcapsules (prepared in Example 1), and blank microcapsules without the technical material and stabilizer (basically the same as the wall material, ratio and preparation method in Example 1). In infrared curve a, the broad peak around 3000-2850 cm is the stretching vibration absorption peak of methyl and methylene groups of abamectin; the strong absorption peak at 1720 cm is the stretching vibration absorption peak of the carbonyl group in fluxapyroxad. In infrared curve c, at 2250 cm -1 around is the stretching vibration absorption peak of methyl and methylene groups of abamectin; the strong absorption peak at 1720 cm is the stretching vibration absorption peak of the carbonyl group in fluxapyroxad. In infrared curve c, the strong absorption peak at 2250 cm -1 is the stretching vibration absorption peak of the carbonyl group in fluxapyroxad. In infrared curve c, at 2250 cm-1 The broad peak at [location] is the stretching vibration absorption peak of the carbonyl group in the polyurea. Compared with the infrared c curve, in the infrared b curve, there is an obvious infrared absorption peak at around 2250 cm -1 , indicating that the isocyanate group reacts with the amino group to form polyurea. At the same time, the characteristic absorption peak at around 3000 - 2850 cm -1 and the strong absorption peak at 1720 cm -1 are the characteristic absorption peaks of the original drug. The infrared b curve contains both the polyurea absorption peak and the characteristic absorption peak of the original drug, further proving that abamectin and the original fludioxonil drug are successfully encapsulated by the capsule wall formed by the reaction of MDI and ethylenediamine.

[0411] The above content is a schematic description of the present invention and its implementation manners. This description is not restrictive. What is shown in the embodiments is only one of the implementation manners of the present invention, and the actual implementation manners are not limited thereto. Therefore, if those of ordinary skill in the art are inspired by it and, without departing from the gist of the present invention, design similar implementation manners and embodiments to this technical solution without creative efforts, they shall fall within the protection scope of the present invention.

Claims

1. Microcapsules containing abamectin and fluxapyroxad, characterized in that, the microcapsules contain the technical material and a stabilizer; the technical material contains a first active ingredient and a second active ingredient; the first active ingredient contains abamectin, and the second active ingredient contains fluxapyroxad; the stabilizer contains dimethyl phthalate, tributyl acetylcitrate and dioctyl phthalate; the median particle size D50 of the microcapsules is 0.6 - 5.0 μm, and the maximum particle size D90 is 1.0 - 15.0 μm.

2. The microcapsules containing abamectin and fluxapyroxad according to claim 1, characterized in that, the content of abamectin in the microcapsules is 0.05 - 0.20 g / g.

3. The microcapsules containing abamectin and fluxapyroxad according to claim 1 or 2, characterized in that, the content of fluxapyroxad in the microcapsules is 0.10 - 0.30 g / g.

4. The microcapsules containing abamectin and fluxapyroxad according to claim 1, characterized in that, the weight ratio of dimethyl phthalate, tributyl acetylcitrate and dioctyl phthalate in the stabilizer is (1 - 25):(1 - 15):1; preferably (1 - 20):(1 - 8):1; more preferably (1 - 10):(1 - 5):1; most preferably (1 - 5):(1 - 4):

1.

5. The microcapsules containing abamectin and fluxapyroxad according to claim 1, characterized in that, the mass of the stabilizer is not higher than 4 times the mass of the technical material.

6. The microcapsules containing abamectin and fluxapyroxad according to claim 1, characterized in that, in the stabilizer, the weight percentage of dioctyl phthalate in the stabilizer is not less than 10%.

7. Microcapsules containing abamectin and fluxapyroxad, characterized in that, the microcapsules contain abamectin, fluxapyroxad, dimethyl phthalate, tributyl acetylcitrate and dioctyl phthalate; the median particle size D50 of the microcapsules is 0.6 - 5.0 μm, and the maximum particle size D90 is 1.0 - 15.0 μm; preferably the median particle size D50 of the microcapsules is 0.8 - 4.0 μm, and the maximum particle size D90 is 1.2 - 12.0 μm; preferably the median particle size D50 of the microcapsules is 1.0 - 3.0 μm, and the maximum particle size D90 is 2.0 - 6.0 μm; preferably the median particle size D50 of the microcapsules is 1.0 - 2.0 μm, and the maximum particle size D90 is 2.5 - 5.0 μm; by weight parts, the microcapsules contain:

8. The microcapsules containing abamectin and fluxapyroxad according to any one of claims 1 - 7, characterized in that, the capsule wall of the microcapsules contains a ureido group; the ureido group is obtained by reacting an isocyanate group with an amino group.

9. The microcapsules containing abamectin and fluxapyroxad according to claim 8, characterized in that, The isocyanate group is derived from an isocyanate, and the isocyanate is selected from one or more of isophorone diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, and diphenylmethane diisocyanate; the amino group is derived from a polyamine, and the polyamine is selected from one or more of hexamethylenediamine, triethylenetetramine, ethylenediamine, hexamethylenetetramine, and isophorone diamine.

10. A microcapsule suspension containing abamectin and fluxapyroxad, characterized in that, The microcapsules containing abamectin and fluxapyroxad according to any one of claims 1 to 9 are dispersed in a solution to obtain a microcapsule suspension containing abamectin and fluxapyroxad; preferably, the microcapsule suspension further contains an antifreeze and a thickener.

11. The microcapsule suspension containing abamectin and fluxapyroxad according to claim 10, characterized in that, The weight percentage of the microcapsules in the microcapsule suspension is 10 to 70 wt%; Preferably, the weight percentage of the microcapsules in the suspension is 20 to 60 wt%; More preferably, the weight percentage of the microcapsules in the suspension is 30 to 50 wt%.

12. A method for preparing the microcapsules containing abamectin and fluxapyroxad according to any one of claims 1 to 9, comprising: Preparing an aqueous phase component, the aqueous phase component containing an emulsifying dispersant and an antifoaming agent; Preparing an oil phase component, the oil phase component containing abamectin and fluxapyroxad dissolved in a mixed solvent of dimethyl phthalate, tributyl acetylcitrate, and dioctyl phthalate, and an oily wall material; Emulsifying, bringing the prepared oil phase component into contact and mixing with the aqueous phase component and shearing and stirring to obtain an oil-in-water emulsion; Wall reaction of the capsule, mixing the aqueous wall material with the emulsion obtained by emulsification, and performing interfacial polymerization to form a capsule wall to obtain microcapsules containing active ingredients, continuously accompanied by a stirring operation; Heat preservation and curing to obtain a solution containing microcapsules.

13. Use of the microcapsules containing abamectin and fluxapyroxad according to any one of claims 1 to 9 in pesticides.

14. The use according to claim 13, for killing nematodes and / or sterilizing.

Images