Spinetoram dinotefuran water dispersible granule as well as preparation method and application thereof

Abstract

The invention relates to the technical field of pesticides, in particular to spinetoram dinotefuran water dispersible granules as well as a preparation method and application thereof. The water dispersible granule is prepared from the following raw materials in percentage by weight: 5 to 20 percent of spinetoram, 30 to 50 percent of dinotefuran, 8 to 25 percent of auxiliaries and the balance of filler. The spinetoram-dinotefuran water dispersible granule disclosed by the invention not only has a remarkable insect prevention effect, but also has excellent safety, and after the spinetoram-dinotefuran water dispersible granule is applied, the dry heart rate of rice is relatively low, and the plant protection effect is good. And the obtained water dispersible granules are uniform and dense solid particles, are free of impurities and hard blocks, and have stable physical and chemical properties and excellent comprehensive properties.

Description

Technical Field

[0001] This invention relates to the field of pesticide technology, and in particular to an ethyl spinosad·fipronil water-dispersible granule, its preparation method, and its application. Background Technology

[0002] The rice stem borer (Chilo suppressalis), a major borer pest in Asian rice-growing regions, has long relied on chemical control, leading to a significant increase in the risk of resistance to traditional pesticides. Recent field monitoring data show an increasing trend in pesticide resistance in the rice stem borer, making the development of a highly effective and safe insecticide essential for the sustainable control of pests such as the rice stem borer.

[0003] Meanwhile, most pesticide formulations on the market that combine ethyl spinosad and dinotefuran as active ingredients are in the form of suspensions or wettable powders, which suffer from poor suspension stability, easy hygroscopic agglomeration, and slow disintegration, thus failing to fully and effectively exert their efficacy. Water-dispersible granules (WDG), as an environmentally friendly formulation, have advantages such as good dispersibility and low dust. However, the solubility of ethyl spinosad in water is only about 10 mg / L, dinotefuran is extremely hygroscopic and prone to agglomeration, and dinotefuran and ethyl spinosad have poor compatibility. These properties make it difficult to formulate ethyl spinosad and dinotefuran into water-dispersible granules, limiting their application.

[0004] Chinese invention patent CN101961017B discloses a water-dispersible granule formulation of flufenoxuron and azadirachtin, and its preparation method. This formulation addresses the problems of single formulation and environmental pollution associated with existing products. Chinese invention patent application CN105851047A discloses a water-dispersible granule formulation of chlorfenapyr and dinotefuran, and its preparation method. This formulation addresses the problems of pesticide resistance in lepidopteran pests and environmental pollution. However, these existing technologies have not solved the aforementioned technical problems, and there is an urgent need for a novel insecticide formulation that combines high efficacy, reliable physicochemical stability, and environmental friendliness. Summary of the Invention

[0005] In response to the current challenges of increased resistance of rice stem borers to traditional pesticide formulations, the lack of effective and highly effective insecticides, and the difficulty in preparing ethyl spinosad and dinotefuran into water-dispersible granules, this invention proposes an ethyl spinosad·dinotefuran water-dispersible granule that combines high efficacy, reliable physicochemical stability, and environmental friendliness, and has broad application prospects.

[0006] The first aspect of the present invention provides an ethyl spinosad·fipronil water-dispersible granule, wherein the raw materials for preparing the water-dispersible granule include, by weight percentage: 5-20% ethyl spinosad, 30-50% fipronil, 8-25% adjuvants, and filler to make up the balance.

[0007] Preferably, the sum of the amounts of spinosad and dinotefuran accounts for 45-55% of the water-dispersible granules, and the mass ratio of spinosad to dinotefuran is 1:(2-6).

[0008] More preferably, the total mass of the ethyl spinosad and fipronil accounts for 50% of the water-dispersible granules, and the mass ratio of the ethyl spinosad and fipronil is 1:4; that is, 50% ethyl spinosad·fipronil water-dispersible granules.

[0009] Preferably, the adjuvants comprise 7-15% dispersant and 2-5% wetting agent based on the total mass of the water-dispersible granules.

[0010] More preferably, the weight ratio of the wetting agent to the dispersant is (2-6):1; most preferably 4.5:1.

[0011] Preferably, the dispersant comprises at least one of polycarboxylate, sodium methylene bis(naphthalene) sulfonate, lignin sulfonate, alkyl naphthalene sulfonate, sulfonated succinate, polyoxyethylene ether or its derivatives, and phosphate ester.

[0012] More preferably, the dispersant comprises a polycarboxylate and sodium methylene bisnaphthalene sulfonate, wherein the mass ratio of the polycarboxylate to sodium methylene bisnaphthalene sulfonate is 1 (1.5-3); more preferably, it is 1:2.

[0013] Preferably, the wetting agent includes at least one of naphthalene sulfonate, alkyl sulfate, alkyl sulfonate, fatty alcohol polyoxyethylene ether, phosphate ester, alcohol ether carboxylate, and sulfosuccinate; more preferably, it is naphthalene sulfonate.

[0014] Preferably, the filler includes at least one of corn starch, cassava starch, ammonium sulfate, potassium dihydrogen phosphate, kaolin, calcium carbonate, and diatomaceous earth.

[0015] More preferably, the filler comprises corn starch and ammonium sulfate, wherein the mass ratio of corn starch to ammonium sulfate is 1:(1.2-4); more preferably 1:1.6.

[0016] This invention, through research, has discovered that a highly effective water-dispersible granule can be prepared by combining ethyl spinosad, dinotefuran, and specific adjuvants. Particularly preferred adjuvants include wetting agents and dispersants, with the dispersant comprising polycarboxylate and sodium methylene bis(naphthalene) sulfonate, and the wetting agent being a low-foaming naphthalene sulfonate wetting agent. This effectively enhances the control efficacy of the water-dispersible granule against rice stem borer. Furthermore, the optimized formulation of the water-dispersible granule also exhibits excellent safety, resulting in a lower rate of dead heart in rice plants after application and good plant survival.

[0017] A second aspect of the present invention provides a method for preparing ethyl spinosad·diflubenzuron water-dispersible granules, wherein the preparation steps of the dispersible granules include:

[0018] S1. Ethyl spinosad and fipronil were subjected to ultra-fine pulverization treatment respectively;

[0019] S2. Mix the ultra-finely pulverized ethyl spinosad and fipronil with the adjuvants and fillers, add solvent, knead, and obtain material one;

[0020] S3. Extrude and granulate material one to obtain material two;

[0021] S4. Dry and sieve the material 2 to obtain water-dispersible granules.

[0022] Preferably, the particle size of both ethyl spinosad and fipronil after ultrafine grinding is ≤20μm.

[0023] Preferably, the amount of solvent added is 10-30 wt% based on the total mass of the water-dispersible granules; more preferably, it is 15-20%.

[0024] The solvent is not particularly limited, as long as it can achieve the kneading purpose, such as water, methanol, acetone, ethyl acetate, 1,2-dichloroethane, n-octanol, xylene, n-hexane, heptane, acetonitrile, etc.

[0025] Preferably, the kneading time is 10-60 minutes; more preferably, the kneading time is 15-30 minutes.

[0026] Preferably, in step S4, the material is dried to a moisture content of ≤1.5%, and the particle size is 30-60 mesh after sieving.

[0027] Water-dispersible granules require extremely high standards for disintegration time and suspension rate of active ingredients, necessitating a disintegration time ≤ 60 seconds and a suspension rate ≥ 90%. However, the solubility of ethyl spinosad in water is only about 10 mg / L, and dinotefuran is highly hygroscopic and prone to agglomeration. Furthermore, dinotefuran and ethyl spinosad have poor compatibility. These factors often lead to agglomeration or crystallization defects in formulations containing ethyl spinosad and dinotefuran, resulting in water-dispersible granules with long disintegration times and low suspension rates, failing to meet usage requirements. Achieving high-activity-in-content formulations is even more challenging. Existing similar water-dispersible granules show a suspension rate decrease from 92% to 68% after heat storage (54℃±2℃, 14 days), rendering them ineffective. Simultaneously, water-dispersible granules containing ethyl spinosad and dinotefuran are highly sensitive to process conditions. This is mainly because during extrusion granulation, significant differences in the melting point or decomposition temperature of the active ingredients can lead to localized melting of some of the active ingredients. Ethyl spinosad decomposes at 497.8℃, while dinotefuran has a melting point of 107℃. During extrusion granulation, the particle surface is prone to adhesion or internal hollowness. Previous studies have shown that excessively fast dinotefuran feeding can cause the kneader discharge temperature to rise to 65℃, triggering dinotefuran decomposition and resulting in a 15% decrease in the effective ingredient content of the finished product.

[0028] This invention, through an optimized water-dispersible granule formulation and specific preparation conditions, prepares ethyl spinosad·fipronil water-dispersible granules, effectively solving technical problems such as particle disintegration, suspension rate, and stability under high active ingredient loading. The resulting water-dispersible granules possess both high efficacy and reliable stability, exhibiting normal performance after high and low temperature storage without clumping. They also demonstrate reliable dilution stability, persistent low foaming, low residue content after pouring or washing, and pass wet sieving tests. In contrast, adjusting the adjuvants to other wetting and dispersing agents results in varying degrees of degradation in physicochemical properties, failing to achieve similar technical effects. Furthermore, the water-dispersible granules prepared by this invention exhibit fine, dense, and uniform particles, without surface adhesion, uneven distribution, hollow particles, or other abnormalities.

[0029] In some embodiments, an air jet mill is used to perform ultrafine grinding of ethyl spinosad and dinotefuran.

[0030] This invention does not impose any particular limitation on the kneading equipment, as long as it can achieve the purpose of kneading; for example: twin-shaft paddle kneader, planetary mixing kneader, high-power disperser, vacuum kneader, etc.

[0031] This invention does not impose any particular limitation on the equipment used for extrusion granulation, as long as it can achieve the purpose of extrusion granulation; for example: rotary granulator, swing granulator, screw extrusion granulator, twin-screw extrusion granulator, ring die granulator, flat die granulator, melt spray granulator, fluidized bed granulator, double roller extrusion granulator, etc.

[0032] This invention does not impose any particular limitation on the drying equipment, as long as it can achieve the purpose of drying; for example: fluidized bed dryer, spray dryer, airflow dryer, flash dryer, paddle dryer, disc dryer, vacuum rake dryer, belt dryer, rotary drum dryer, spouted bed dryer, etc.

[0033] The third aspect of this invention provides an application of ethyl spinosad·fipronil water-dispersible granules, which are used for the control of rice stem borer, rice leaf roller, rice planthopper and thrips.

[0034] Beneficial effects:

[0035] This invention provides an ethyl spinosad·fipronil water-dispersible granule, its preparation method, and its application, which have the following advantages:

[0036] (1) This invention uses ethyl spinosad and dinotefuran in a specific ratio to exert a control effect through a dual mechanism of rapidly paralyzing larvae and killing borer larvae via systemic transmission, which can cover the entire damage cycle of rice stem borer; according to indoor toxicity tests, the co-toxicity coefficient of 10% ethyl spinosad + 40% dinotefuran is 145, which shows synergistic effect and can effectively control rice pests.

[0037] (2) The present invention has found that the combination of ethyl spinosad and dinotefuran can effectively delay the development of resistance in rice stem borer and further improve the efficacy of the pesticide; it also has excellent safety, and the rice has a low dead heart rate after application and good plant protection effect.

[0038] (3) The ethyl spinosad·fipronil water-dispersible granules of the present invention have the technical advantages of multi-target coverage and broad-spectrum insecticidal effect; in addition to rice stem borer, it also shows excellent control effect on rice planthopper (e.g. brown planthopper, white-backed planthopper), thrips and rice leaf roller; after trials in the rice-growing areas of South China, the obtained water-dispersible granules can control rice stem borer, rice planthopper and rice leaf roller at the same time with one application, reducing the number of applications by 30% and also reducing costs.

[0039] (4) The preferred adjuvants of this invention include wetting agents and dispersants. The dispersants include polycarboxylate and sodium methylene bis(naphthalene) sulfonate, and the wetting agent is a low-foaming wetting agent of naphthalene sulfonate, which can effectively improve the physicochemical stability of water-dispersible granules against rice stem borers. Even with the addition of high concentrations of active ingredients (50% of ethyl spinosad and dinotefuran), the resulting water-dispersible granules can still maintain rapid disintegration (disintegration time 15s) and high suspension rate (95%), ensuring that the water-dispersible granules are evenly distributed at the base of the rice stem, further enhancing the control effect against boring pests.

[0040] (4) Through the optimization of the formulation and process, this invention effectively overcomes the various resistances of ethyl spinosad and fipronil when applied to water-dispersible granules, and solves the technical problems of particle disintegration, suspension rate and stability under high active ingredient load. The final water-dispersible granules are fine, dense and uniform particles, and there will be no abnormalities such as particle surface adhesion, uneven distribution and hollowness. It is highly operable.

[0041] (5) Compared with suspending agents, the water-dispersible granules prepared by the present invention can reduce dust pollution by 80% during application, making them more suitable for operation methods such as drone aerial spraying and having broad application prospects. Attached Figure Description

[0042] Figure 1 Actual image of the water-dispersible granules from Example 1;

[0043] Figure 2 Photo of the water-dispersible granules from Comparative Example 5. Detailed Implementation

[0044] The sources of some of the raw materials in the specific embodiments of the present invention are as follows.

[0045] Polycarboxylate: sourced from Parrun (Shanghai) Industrial Technology Co., Ltd., product model PRTech-D8729.

[0046] Sodium methylene bisnaphthalene sulfonate: sourced from Parrun (Shanghai) Industrial Technology Co., Ltd., product model PRTech-D8636.

[0047] Naphthalene sulfonate: sourced from Parrun (Shanghai) Industrial Technology Co., Ltd., product model PRTech-DW6671.

[0048] Corn starch: sourced from Weifang Shengtai, product model YMDF.

[0049] Ammonium sulfate: sourced from Shandong Rongxin, product model LSA.

[0050] Isooctyl alcohol polyoxyethylene ether: sourced from Nantong Deyi Chemical Co., Ltd., product model JFC-E.

[0051] Polyethylene glycol: sourced from Qingdao Kenuo Chemical Co., Ltd., product model PEG-400.

[0052] Sulfate salt: sourced from Beijing Hanmok Chemical Technology Co., Ltd., product model W-2006.

[0053] Nonionic block polyether compound: sourced from Beijing Hanmok Chemical Technology Co., Ltd., product model DSC-5005.

[0054] Example 1

[0055] This embodiment provides an ethyl spinosad·fipronil water-dispersible granule and its preparation method. The formulation of the water-dispersible granule is shown in Table 1 below.

[0056] Table 1

[0057]

[0058] The preparation steps of the water-dispersible granules include:

[0059] S1. Ethyl spinosad and dinotefuran were subjected to ultrafine grinding using an air jet mill, and the particle size of ethyl spinosad and dinotefuran after treatment was ≤20μm.

[0060] S2. The ultra-finely pulverized ethyl spinosad and fipronil were mixed with adjuvants and fillers in a twin-shaft paddle kneader, and solvent (water, the amount added was 16wt% of the water-dispersible granules) was added. The mixture was kneaded for 15 minutes to obtain material one.

[0061] S3. Material 1 is continuously fed into the extruder hopper via a screw conveyor, and then extruded and granulated in a rotary granulator at 38 r / min to obtain material 2.

[0062] S4. Transfer material 2 to a fluidized bed dryer and dry it until the moisture content is ≤1.5%. After grading by a 30-60 mesh vibrating screen, water-dispersible granules are obtained.

[0063] Comparative Example 1

[0064] The specific implementation method is the same as in Example 1; the difference is that the auxiliary agent is sodium methylene bisnaphthalene sulfonate, and the amount added is adjusted to 7.0 wt%; the difference is made up with ammonium sulfate.

[0065] Comparative Example 2

[0066] The specific implementation method is the same as in Example 1; the difference is that the additive is isooctanol polyoxyethylene ether, and the amount added is adjusted to 6.5 wt%; the difference is made up with ammonium sulfate.

[0067] Comparative Example 3

[0068] The specific implementation method is the same as in Example 1; the difference is that the additive is polyethylene glycol, and the amount added is adjusted to 7.0 wt%; the difference is made up with ammonium sulfate.

[0069] Comparative Example 4

[0070] The specific implementation method is the same as in Example 1; the difference is that the auxiliary agent is a sulfate ester salt, and the amount added is adjusted to 6.0 wt%; the difference is made up with ammonium sulfate.

[0071] Comparative Example 5

[0072] The specific implementation method is the same as in Example 1; the difference is that the auxiliary agent is naphthalene sulfonate, and the amount added is adjusted to 5.5 wt%; the difference is made up with ammonium sulfate.

[0073] Comparative Example 6

[0074] The specific implementation method is the same as in Example 1; the difference is that the additive is sodium lignosulfonate, and the amount added is adjusted to 6.5 wt%; the difference is made up with ammonium sulfate.

[0075] Comparative Example 7

[0076] The specific implementation method is the same as in Example 1; the difference is that the additive is a nonionic block polyether, and the amount added is adjusted to 6.0 wt%; the difference is made up with ammonium sulfate.

[0077] Performance testing

[0078] 1. Field efficacy test

[0079] The field efficacy test of this invention was conducted in July 2024 in Sanfanggang Village, Wushitou Community, Xinzhan District, Hefei City, Anhui Province. The experimental site had suffered from severe rice stem borer infestations in previous years.

[0080] As shown in Table 2, experimental groups 1-6 were designed, with each group treated 4 times (a total of 24 plots), and each plot area was 20m². 2 The study employed a randomized block design. A single application of pesticide was conducted during the peak hatching period of rice stem borer eggs to the initial peak of young larvae. The pesticide was prepared using a two-stage dilution method, and then sprayed evenly and at a uniform rate, progressing from low to high concentration, ensuring no overlap or missed areas. The sprayers were rinsed with clean water before each pesticide treatment. A blank control was sprayed with an equal volume of water, approximately 600 liters per hectare. Reagent safety was assessed 3 days post-application; all tested pesticides (numbers 1-5) were found to be safe for the crop with no harmful effects. 30 days post-application, the number of dead cores, plant survival rate, number of live insects, and pest control effect were measured and calculated in the experimental areas. The results are recorded in Table 3.

[0081] Safety investigation method: 3 days after application, visually inspect the rice for symptoms of pesticide damage such as dwarfing, chlorosis, and deformity.

[0082] The calculation methods for dead heart count, plant preservation effect, and insect control effect are as follows:

[0083] Dead heart rate (%) = (Number of dead hearts investigated / Total number of plants investigated) × 100%;

[0084] Plant retention rate (%) = (post-treatment heart rot rate in blank control area - post-treatment heart rot rate in drug-treated area) / post-treatment heart rot rate in blank control area × 100%;

[0085] Insect control effect (%) = (Number of live insects in the blank control area - Number of live insects in the pesticide-treated area) / Number of live insects in the blank control area × 100%.

[0086] Table 2

[0087]

[0088]

[0089] The test agents listed in Table 2 are: 50% ethyl spinosad·fipronil water-dispersible granules, which are the finished ethyl spinosad·fipronil water-dispersible granules provided in Example 1; 20% fipronil soluble granules, which are from Shandong Heze Beilian Pesticide Manufacturing Co., Ltd.; and 25% ethyl spinosad water-dispersible granules, which are from Corteva Agricultural Technology Co., Ltd.

[0090] Table 3

[0091]

[0092] As can be seen from the data in Table 3, the 50% ethyl spinosad·fipronil water-dispersible granules of the present invention have not only significant insect control effects, but also excellent safety. After application, the rice has a low rate of dead heart and good plant protection effect.

[0093] 2. Physicochemical tests

[0094] The physicochemical properties of the 50% ethyl spinosad·dinotefuran water-dispersible granules of Example 1 are shown in Table 4 below. As can be seen from the data in Table 4, the 50% ethyl spinosad·dinotefuran water-dispersible granules of the present invention are dry and free-flowing solid particles, free of dust, visible foreign impurities, and lumps, meeting the product requirements.

[0095] Table 4

[0096]

[0097]

[0098] Physicochemical tests were performed on Example 1 and Comparative Examples 1-7, and the results are recorded in Table 5. The test conditions for some indicators in Table 5 are as follows.

[0099] Thermal storage conditions: Store at 54℃ for 14 days.

[0100] Cold storage conditions: Store at -20℃ for 14 days.

[0101] Dilution stability: Dilute with water 20 times, mix well and test. If the diluted solution is homogeneous and has no precipitates, it is recorded as A. If the diluted solution is not homogeneous and has precipitates, it is recorded as B.

[0102] Table 5

[0103]

[0104]

[0105] The data in Table 5 show that the 50% ethyl spinosad·dinotefuran water-dispersible granules of this invention exhibit excellent physicochemical properties, performing normally after both high and low temperature treatments without clumping. It also demonstrates reliable dilution stability, persistent low foaming, low residue content after pouring or washing, and passes wet sieving tests. However, when other wetting and dispersing agents are used, the physicochemical properties deteriorate to varying degrees, and none achieve similar technical effects.

[0106] Meanwhile, comparative images of the water-dispersible granules from Example 1 and Comparative Example 5 (corresponding to...) Figure 1 and Figure 2 As can be seen, the water-dispersible granules prepared by the specific additives in this invention exhibit normal quality, with fine, dense, and uniform particles; while the water-dispersible granules prepared in Comparative Example 5 (with naphthalene sulfonate low-foaming wetting agent as the additive) exhibit abnormal quality, with uneven particles and voids.

Claims

1. A water-dispersible granule formulation of ethyl spinosad·fipronil, characterized in that, The raw materials for preparing the water-dispersible granules, by weight percentage, include: 5-20% ethyl spinosad, 30-50% dinotefuran, 8-25% auxiliaries, and filler to make up the balance.

2. The preparation method according to claim 1, characterized in that, The sum of the amounts of spinosad and dinotefuran accounts for 45-55 wt% of the water-dispersible granules, and the mass ratio of spinosad to dinotefuran is 1:(2-6).

3. The ethyl spinosad·dinotefuran water-dispersible granules according to claim 1, characterized in that, Based on the total mass of the water-dispersible granules, the additives include 7-15% dispersant and 2-5% wetting agent.

4. The ethyl spinosad·dinotefuran water-dispersible granules according to claim 3, characterized in that, The weight ratio of the wetting agent to the dispersant is (2-6):

1.

5. The ethyl spinosad·dinotefuran water-dispersible granules according to claim 3 or 4, characterized in that, The dispersant comprises a polycarboxylate and sodium methylene bisnaphthalene sulfonate, wherein the mass ratio of the polycarboxylate to sodium methylene bisnaphthalene sulfonate is 1:(1.5-3).

6. The ethyl spinosad·dinotefuran water-dispersible granules according to claim 3 or 4, characterized in that, The wetting agent includes at least one of naphthalene sulfonate, alkyl sulfate, alkyl sulfonate, fatty alcohol polyoxyethylene ether, phosphate ester, alcohol ether carboxylate, and sulfosuccinate.

7. The ethyl spinosad·dinotefuran water-dispersible granules according to claim 1 or 2, characterized in that, The filler includes at least one of corn starch, cassava starch, ammonium sulfate, potassium dihydrogen phosphate, kaolin, calcium carbonate, and diatomaceous earth.

8. The ethyl spinosad·dinotefuran water-dispersible granules according to claim 7, characterized in that, The filler comprises corn starch and ammonium sulfate, wherein the mass ratio of corn starch to ammonium sulfate is 1:(1.2-4).

9. A method for preparing ethyl spinosad·diflubenzuron water-dispersible granules according to any one of claims 1 to 8, characterized in that, include: S1. Ethyl spinosad and fipronil were subjected to ultra-fine pulverization treatment respectively; S2. Mix the ultra-finely pulverized ethyl spinosad and fipronil with the adjuvants and fillers, add solvent, knead, and obtain material one; S3. Extrude and granulate material one to obtain material two; S4. Dry and sieve the material 2 to obtain water-dispersible granules.

10. The application of the ethyl spinosad·dinotefuran water-dispersible granules according to any one of claims 1 to 8, characterized in that, The water-dispersible granules are used for the control of rice stem borer, rice leaf roller, rice planthopper, and thrips.

Images