A suspension containing pyriproxyfen and tolfenpyrad, its preparation method and application

Abstract

The present application relates to the technical field of pesticides, and discloses a suspension agent containing pyriproxyfen and tolfenpyrad as well as a preparation method and application thereof.The suspension agent containing pyriproxyfen and tolfenpyrad provided by the present application comprises the following components in mass percentage: 5-30% of pyriproxyfen, 5-30% of tolfenpyrad, 2-10% of a dispersing agent, 1-3% of a wetting agent, 0.3-2% of a thickening agent, 3-7% of an antifreezing agent, 0.1-0.8% of an antifoaming agent, 0.05-0.2% of an antifungal agent, and the balance of water; and the wetting agent has a hydrophilic-lipophilic balance value of 7-12.The present application uses the wetting agent with a hydrophilic-lipophilic balance value of 7-12 and other additives at specific mass contents, thereby improving the storage stability of the suspension agent containing two low-melting-point raw materials, i.e., pyriproxyfen and tolfenpyrad, at high and low temperatures, reducing the decomposition rate of effective components, and increasing the heat storage suspension rate of the suspension agent to more than 90%.

Description

Technical Field

[0001] This invention relates to the field of pesticide technology, specifically to a suspension concentrate containing pyriproxyfen and acetamiprid, its preparation method, and its application. Background Technology

[0002] Pyriproxyfen is a phenyl ether insect growth regulator that disrupts insect growth. It is a novel insecticide belonging to the juvenile hormone analogue family. Its chemical name is 4-phenoxyphenyl(RS)-2-(2-pyridyloxy)propyl ether, and its molecular formula is C2. 20 N 19 NO3 has the characteristics of systemic transfer activity, low toxicity, safety to crops, low toxicity to fish, minimal impact on the ecological environment, and long residual effect. It has good control effects on whiteflies, scale insects, diamondback moths, beet armyworms, cotton bollworms, pear psyllids, thrips, and cotton bollworms.

[0003] Tolfenpyrad is a novel pyrazole heterocyclic insecticide and acaricide, chemically named 4-chloro-3-ethyl-1-methyl-N-{[4-(4-methylphenoxy)phenyl]-methyl}-1H-pyrazole-5-carboxamide, with the molecular formula C1. 21 H 22 ClN3O2. Its mechanism of action is to inhibit electron transport system complex I in the mitochondrial metabolic system, thereby hindering electron transport and preventing insects from providing and storing energy. It is highly effective against diamondback moth larvae (Lepidoptera) and thrips (Thysanoptera). Suspension concentrates, as an environmentally friendly pesticide formulation, have become a research hotspot due to their small particle size, good dispersibility, and high efficacy. Existing technologies disclose suspension concentrates containing pyriproxyfen and acetamiprid to improve insecticidal effects.

[0004] However, the suspension prepared by combining pyriproxyfen and acetamiprid currently exhibits poor stability and is prone to melting and paste formation during sand milling. This is mainly because both active ingredients are low-melting-point active ingredients: pyriproxyfen has a melting point of 48-50℃, and acetamiprid has a melting point of 88-89℃. Combining these two low-melting-point active ingredients to prepare a suspension easily generates a large amount of heat during sand milling, causing the surface of the active ingredient particles to soften or even melt. The softened particles stick together, resulting in poor flowability. After cooling, the melted and stuck particles cannot return to their original microcrystalline state, leading to crystallization, precipitation, and a decrease in suspension rate under heat storage conditions. At the same time, the low-temperature stability is also poor, seriously affecting product quality and field efficacy. Summary of the Invention

[0005] This invention provides a suspension containing pyriproxyfen and acetamiprid, its preparation method, and its application, to solve the problems of poor stability, easy crystallization and precipitation, low suspension rate, and easy melting and paste formation of suspensions containing pyriproxyfen and acetamiprid under high and low temperature conditions in the prior art.

[0006] In a first aspect, the present invention provides a suspension containing pyriproxyfen and acetamiprid, comprising, by weight percentage, the following components: pyriproxyfen 5%-30%, acetamiprid 5%-30%, dispersant 2%-10%, wetting agent 1%-3%, thickener 0.3%-2%, antifreeze 3%-7%, defoamer 0.1%-0.8%, mildew inhibitor 0.05%-0.2%, with the balance being water; wherein the hydrophilic-lipophilic balance value of the wetting agent is 7-12.

[0007] In one alternative embodiment, the dispersant comprises at least one of lignin sulfonate, naphthalene sulfonate formaldehyde condensate, and polycarboxylate.

[0008] In one alternative embodiment, the wetting agent comprises at least one of block polyether and polyoxyethylene ether sulfate, preferably block polyether.

[0009] In one optional embodiment, the thickener includes at least one of xanthan gum, silica, magnesium aluminum silicate, and sepiolite; preferably sepiolite and xanthan gum.

[0010] In one optional embodiment, the mass ratio of sepiolite to xanthan gum is 3-8:1, preferably 4-7.5:1.

[0011] In one alternative embodiment, the antifreeze includes at least one of ethylene glycol, propylene glycol, glycerol, polyethylene glycol, and urea.

[0012] In one optional embodiment, the defoamer includes at least one of silicone defoamers, ketone defoamers, fatty acid defoamers, and fatty alcohol defoamers; preferably, it is a silicone defoamer.

[0013] In one optional embodiment, the antifungal agent includes at least one of isothiazolinone, Kathon, benzoic acid and its salts, and sorbic acid and its salts; preferably isothiazolinone.

[0014] In one optional embodiment, the mass ratio of acetamiprid to pyriproxyfen is 1:5-5:1.

[0015] In one alternative embodiment, the dispersant comprises a polycarboxylate and an alkylnaphthalene sulfonate formaldehyde condensate.

[0016] In one optional embodiment, the mass ratio of the polycarboxylate and alkylnaphthalene sulfonate formaldehyde condensate is 1:0.5-2, preferably 1:1.5.

[0017] Secondly, the present invention provides a method for preparing the above-mentioned suspension containing pyriproxyfen and acetamiprid, comprising the following steps: Pyriproxyfen, azoxystrobin, dispersant, wetting agent, antifreeze, a portion of defoamer, mildew inhibitor, a portion of thickener, and water are mixed, homogenized, and then ground. Another portion of defoamer and another portion of thickener are added, and the mixture is homogenized a second time to obtain a suspension containing pyriproxyfen and azoxystrobin.

[0018] In one optional embodiment, the mixing speed is 300-1000 rpm and the time is 10-30 min.

[0019] In one optional embodiment, the homogenization rotation speed is 500-2000 rpm, the temperature is 15-30°C, and the time is 15-45 min.

[0020] In one optional embodiment, the grinding speed is 1000-2000 rpm.

[0021] In one alternative embodiment, the particle size D90 is controlled to be less than 5 μm during the grinding process.

[0022] In one optional embodiment, the rotation speed of the secondary homogenization is 500-1000 rpm, and the temperature is 15-30℃.

[0023] In one optional embodiment, the mass ratio of one part of the defoamer to the other part of the defoamer is 1:3-2:1.

[0024] In one optional embodiment, the mass ratio of one portion of the thickener to the other portion of the thickener is 1:5 to 1:3.

[0025] Thirdly, the present invention provides the application of the above-mentioned suspension containing pyriproxyfen and azoxystrobin, or the suspension containing pyriproxyfen and azoxystrobin prepared by the above-mentioned preparation method, in the control of pests.

[0026] In one alternative embodiment, the pests include at least one of the following: tea green leafhopper, cabbage caterpillar, beet armyworm, cotton bollworm, whitefly, thrips, cotton bollworm, pear psyllid, and scale insects.

[0027] The technical solution of this invention has the following advantages: 1. This invention provides a suspension containing pyriproxyfen and acetamiprid, comprising, by mass percentage: pyriproxyfen 5%-30%, acetamiprid 5%-30%, dispersant 2%-10%, wetting agent 1%-3%, thickener 0.3%-2%, antifreeze 3%-7%, defoamer 0.1%-0.8%, fungicide 0.05%-0.2%, with the balance being water; the wetting agent has a hydrophilic-lipophilic balance value of 7-12. This invention, by selecting a wetting agent with a hydrophilic-lipophilic balance value of 7-12 and using it in combination with the dispersant, thickener, antifreeze, defoamer, and fungicide at specific mass concentrations, improves the storage stability of the combined suspension of pyriproxyfen and acetamiprid, two low-melting-point active ingredients, at high and low temperatures, reduces the decomposition rate of the active ingredients, and increases the thermal storage suspension rate of the suspension to over 90%.

[0028] Among them, the dispersant can prevent the sedimentation and aggregation of particles, the thickener constructs a three-dimensional network structure to maintain suspension stability, so that pyriproxyfen and acetamiprid are uniformly dispersed in the aqueous phase; the antifreeze is used to adjust the low temperature stability; the defoamer controls the process foam, so that the suspension has good fluidity and high wet screening pass rate; the antifungal agent can inhibit the growth of mold and ensure the quality of the suspension.

[0029] In summary, this application overcomes the problems of melting and emulsification of the active ingredient by a low HLB value wetting agent, combined with the strong dispersing effect provided by the dispersant, in the case of the pyriproxyfen and acetamiprid compound system during sand milling and easy crystallization and precipitation under heat storage conditions. Furthermore, indoor efficacy tests have demonstrated that this suspension can effectively control the tea green leafhopper.

[0030] 2. This invention provides a suspension containing pyriproxyfen and acetamiprid, wherein the wetting agent is preferably a block polyether, the thickener is preferably sepiolite and xanthan gum, and the dispersant comprises a polycarboxylate and an alkylnaphthalene sulfonate formaldehyde condensate. By combining a composition of polycarboxylate and alkylnaphthalene sulfonate formaldehyde condensate as a dispersant with a block polyether having an HLB value of 7-12 as a wetting agent at specific concentrations, and supplemented with a combination of xanthan gum and sepiolite as a thickener, the stability of pyriproxyfen and acetamiprid in the suspension under both hot and cold storage conditions is significantly improved. The polycarboxylate dispersant has a high ionization state, providing sufficiently strong electrostatic repulsion to ensure thorough dispersion of the active pharmaceutical ingredient particles; the alkylnaphthalene sulfonate formaldehyde condensate has good heat resistance and dispersing properties, contributing to the stability of the suspension under high-temperature conditions.

[0031] 3. This invention provides a method for preparing a suspension containing pyriproxyfen and acetamiprid, comprising the following steps: mixing pyriproxyfen, acetamiprid, a dispersant, a wetting agent, an antifreeze agent, a portion of an antifoaming agent, a fungicide, a portion of a thickener, and water; homogenizing and grinding the mixture; adding another portion of the antifoaming agent and another portion of the thickener; homogenizing a second time to obtain a suspension containing pyriproxyfen and acetamiprid. This preparation method is simple to operate, and the resulting suspension has small particle size, high content of active ingredients, and high suspension rate, without causing problems such as paste formation or crystallization, which is conducive to large-scale production. Attached Figure Description

[0032] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0033] Figure 1 This is a comparison chart of the performance of the suspension prepared in Example 1 of this invention under various conditions in Experiment 1; Figure 2 This is a comparison chart of the performance of the suspension prepared in Example 2 of the present invention after testing under various conditions in Experiment 1. Detailed Implementation

[0034] The following embodiments are provided to better understand the present invention, but the following embodiments do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0035] Unless otherwise specified, all experimental steps or conditions in the examples were performed according to conventional experimental procedures and conditions in the art. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0036] The reagents used in the embodiments and comparative examples of this invention are as follows: Pyriproxyfen: Purchased from Rudong Zhongyi Company, pyriproxyfen content is 98%; Azoxystrobin: Purchased from Qingdao Hengning Biotechnology Co., Ltd., with a content of 98% azoxystrobin; Polycarboxylate dispersant 9100: purchased from Shanghai Zejia Trading Co., Ltd.; Dispersant alkyl naphthalene sulfonate formaldehyde condensate 2852: purchased from Jiangsu Qingyu Chemical Technology Co., Ltd.; Dispersant Soprophor SC: Chemical composition: styrene-phenol polyethylene glycol phosphate salt, purchased from Solvay. Wetting agent block polyethers L62, L43, L44, and L61: purchased from Jiahe Chemical Co., Ltd., with hydrophilic-lipophilic balance (HLB) values ​​of 7, 10, 12, and 3, respectively; Wetting agent block polyether Ethylan NS-500LQ: purchased from Nouryon, with a hydrophilic-lipophilic balance (HLB) value of 14; Organosilicon defoamer: Chemical composition: polydimethylsiloxane, purchased from Momentive, brand name 1522.

[0037] Example 1 This embodiment provides a suspension containing pyriproxyfen and acetamiprid, comprising the following components by mass percentage: pyriproxyfen 5%, acetamiprid 15%, dispersant: 3.2% polycarboxylate dispersant 9100 and 4.8% alkyl naphthalene sulfonate formaldehyde condensate 2852, wetting agent: 1.5% block polyether L62, thickener: 0.16% xanthan gum and 1.2% sepiolite, antifreeze agent: 5% ethylene glycol, defoamer: 0.5% silicone defoamer 1522, mildew inhibitor: 0.15% isothiazolinone, and deionized water to 100%.

[0038] This embodiment also provides a method for preparing a suspension containing pyriproxyfen and azoxystrobin, comprising the following steps: adding deionized water to a mixing tank and starting stirring; sequentially adding 5g of antifreeze ethylene glycol, 3.2g of dispersant polycarboxylate dispersant 9100, 4.8g of dispersant alkyl naphthalene sulfonate formaldehyde condensate 2852, and 1.5g of wetting agent block polyether L62, and stirring at 500rpm for 15min to dissolve; slowly adding 5.1g of pyriproxyfen, 15.3g of azoxystrobin, and 1g of other components. 0.2g sepiolite, 0.15g isothiazolinone and 0.2g organosilicon defoamer 1522 were added and homogenized at 900rpm and 25℃ for 30 minutes; then the material was transferred to a sand mill and ground at 1500rpm until D90 < 5μm; 0.16g xanthan gum and 0.3g defoamer were added, the speed was adjusted to 600rpm, and a second homogenization was carried out at 25℃ until the product was uniform and free of floating matter, thus obtaining a suspension containing pyriproxyfen and acetamiprid.

[0039] Example 2 This embodiment provides a suspension containing pyriproxyfen and acetamiprid and its preparation method, which is basically the same as that in Example 1, except that the sepiolite in the thickener is replaced with magnesium aluminum silicate with a mass percentage of 1.2%.

[0040] Example 3 This embodiment provides a suspension containing pyriproxyfen and acetamiprid, comprising the following components by mass percentage: pyriproxyfen 5%, acetamiprid 30%, dispersant: 4% polycarboxylate dispersant 9100 and 6% alkyl naphthalene sulfonate formaldehyde condensate 2852, wetting agent: 3% block polyether L43, thickener: 0.3% xanthan gum and 1.7% sepiolite, antifreeze agent: 3% ethylene glycol, defoamer: 0.8% silicone defoamer 1522, mildew inhibitor: 0.2% isothiazolinone, and deionized water to 100%.

[0041] This embodiment also provides a method for preparing a suspension containing pyriproxyfen and azoxystrobin, comprising the following steps: adding deionized water to a mixing tank and starting stirring; sequentially adding 3g of antifreeze propylene glycol, 4g of dispersant polycarboxylate dispersant 9100, 6g of dispersant alkyl naphthalene sulfonate formaldehyde condensate 2852, and 3g of wetting agent block polyether L43, and stirring at 1000rpm for 10min to dissolve; slowly adding 5.1g of pyriproxyfen, 30.6g of azoxystrobin, and 1.7g of other components. Add 0.2g of isothiazolinone and 0.4g of organosilicon defoamer 1522 to sepiolite, and homogenize at 2000rpm and 30℃ for 15 minutes; then transfer the material to a sand mill and grind at 1000rpm until D90 < 5μm; add 0.3g of xanthan gum and 0.4g of defoamer, adjust the speed to 500rpm, and homogenize again at 30℃ until the product is uniform and free of floating matter, to obtain a suspension containing pyriproxyfen and acetamiprid.

[0042] Example 4 This embodiment provides a suspension containing pyriproxyfen and acetamiprid, comprising the following components by mass percentage: pyriproxyfen 30%, acetamiprid 5%, dispersant: 2% polycarboxylate dispersant 9100 and 2% alkyl naphthalene sulfonate formaldehyde condensate 2852, wetting agent: 1% block polyether L44, thickener: 0.1% xanthan gum and 0.5% sepiolite, antifreeze agent: 7% ethylene glycol, defoamer: 0.1% silicone defoamer 1522, mildew inhibitor: 0.05% isothiazolinone, and deionized water to 100%.

[0043] This embodiment also provides a method for preparing a suspension containing pyriproxyfen and azoxystrobin, comprising the following steps: adding deionized water to a mixing tank and starting stirring; sequentially adding 7g of antifreeze propylene glycol, 2g of dispersant polycarboxylate dispersant 9100, 2g of dispersant alkyl naphthalene sulfonate formaldehyde condensate 2852, and 1g of wetting agent block polyether L44, and stirring at 300rpm for 30min to dissolve; slowly adding 30.6g of pyriproxyfen, 5.1g of azoxystrobin, and 0.5g of hygroscopic agent. Add 0.05g of isothiazolinone and 0.05g of organosilicon defoamer 1522 to the foaming stone, and homogenize at 500rpm and 15℃ for 45 minutes; then transfer the material to a sand mill and grind at 1000rpm until D90 < 5μm; add 0.1g of xanthan gum and 0.05g of defoamer, adjust the speed to 1000rpm, and homogenize again at 15℃ until the product is uniform and free of floating matter, to obtain a suspension containing pyriproxyfen and acetamiprid.

[0044] Example 5 This embodiment provides a suspension containing pyriproxyfen and acetamiprid and its preparation method, which is basically the same as that in Example 1, except that the dispersant is replaced with 3% polycarboxylate dispersant 9100 and 6% alkyl naphthalene sulfonate formaldehyde condensate 2852.

[0045] Example 6 This embodiment provides a suspension containing pyriproxyfen and acetamiprid and its preparation method, which is basically the same as that in Example 1, except that the thickener is replaced with 0.5% xanthan gum and 1.5% sepiolite.

[0046] Example 7 This embodiment provides a suspension containing pyriproxyfen and acetamiprid and its preparation method, which is basically the same as that in Example 1, except that xanthan gum in the thickener is omitted.

[0047] Example 8 This embodiment provides a suspension containing pyriproxyfen and acetamiprid and its preparation method, which is basically the same as that in Example 1, except that sepiolite in the thickener is omitted.

[0048] Comparative Example 1 This comparative example provides a suspension containing pyriproxyfen and acetamiprid and its preparation method, which is basically the same as that in Example 1, except that the wetting agent block polyether L62 is omitted.

[0049] Comparative Example 2 This comparative example provides a suspension containing pyriproxyfen and acetamiprid and its preparation method, which is basically the same as that in Example 1, except that the wetting agent block polyether L62 is replaced with wetting agent L61 with a mass percentage of 1.5%.

[0050] Comparative Example 3 This comparative example provides a suspension containing pyriproxyfen and acetamiprid and its preparation method, which is basically the same as that in Example 1, except that the wetting agent block polyether L62 is replaced with a wetting agent EthylanNS-500LQ with a mass percentage of 1.5%.

[0051] Comparative Example 4 This comparative example provides a suspension containing pyriproxyfen and acetamiprid and its preparation method, which is basically the same as Example 1, except that the preparation method is different. Specifically, deionized water is added to the mixing tank and stirring is started; 5g of antifreeze ethylene glycol, 3.2g of dispersant polycarboxylate dispersant 9100, 4.8g of dispersant alkyl naphthalene sulfonate formaldehyde condensate 2852, and 1.5g of wetting agent block polyether L62 are added sequentially, and stirred at 500rpm for 15min to dissolve; 5.1g of [unspecified substance] is slowly added. Pyriproxyfen, 15.3g acetamiprid, 1.2g sepiolite, 0.16g xanthan gum, 0.15g isothiazolinone, and 0.5g silicone defoamer 1522 were homogenized at 900rpm and 25℃ for 30 minutes. The material was then transferred to a sand mill and ground at 1500rpm until D90 < 5μm. The speed was adjusted to 6000rpm, and a second homogenization was performed at 25℃ until the product was uniform and free of floating matter, thus obtaining a suspension containing pyriproxyfen and acetamiprid.

[0052] Experimental Example 1 This experimental example tested the performance of the suspensions containing pyriproxyfen and acetamiprid prepared in each embodiment and comparative example.

[0053] 1. Testing Method (1) pH: The pH of the suspensions prepared in each example and comparative example were determined by dilution method according to GB / T 1601-2023 "Determination of pH value of pesticides".

[0054] (2) Initial content and suspension rate: After the suspensions were prepared in each example and comparative example, the contents of pyriproxyfen and acetamiprid and the suspension rate were directly determined. The determination of pyriproxyfen content was carried out in accordance with the determination of pyriproxyfen mass fraction in HG / T 5239-2017 "Industry Standard for Pyriproxyfen Technical Grade". The determination of acetamiprid content was carried out in accordance with section 5.3, "Determination of acetamiprid mass fraction," of Q / 370283HN 067-2024, "acetamiprid technical grade." The suspension rate was determined according to GB / T 14825-2023 "Method for Determination of Suspension Rate of Pesticides" using the active ingredient method.

[0055] (3) Thermal storage stability: The thermal storage stability of each suspension was tested in accordance with GB / T 19136-2021 "Method for Determination of Thermal Storage Stability of Pesticides". The suspensions prepared in each example and comparative example were stored at 54℃ and 65℃ for 14 days respectively. The contents of pyriproxyfen and acetamiprid and the suspension rate of each suspension after thermal storage at the two different temperatures were measured. The measurement method was the same as above. The contents after thermal storage were obtained. The decomposition rate was calculated by comparing the contents after thermal storage with the initial contents. The formula is: thermal storage decomposition rate = (initial contents - contents after thermal storage) / initial contents × 100%.

[0056] (4) Cold storage stability: The low-temperature stability of each suspension was tested according to GB / T 19136-2003 "Determination of Low-Temperature Stability of Pesticides". The suspensions prepared in each example and comparative example were placed at 0±2℃ for 7 days. The content and suspension rate of pyriproxyfen and acetamiprid in each suspension after cold storage were determined. The determination method was the same as above.

[0057] (5) Persistent foaming property: The determination of persistent foaming property of pesticides was carried out in accordance with GB / T 28137-2011. Standard hard water was added to the graduated cylinder to the 180 mL mark. The graduated cylinder was placed on a balance. 1.0 g of sample was weighed, and hard water was added to the mark 9 cm ± 0.1 cm from the bottom of the graduated cylinder stopper. The stopper was closed, and the cylinder was inverted 30 times (2 s each time) with the middle of the graduated cylinder as the center. The cylinder was placed vertically on the test platform and allowed to stand. The foam volume at 1 min ± 10 s was recorded (accurate to 2 mL). The determination was repeated 3 times, and the arithmetic mean was taken as the result of the persistent foaming property determination.

[0058] (6) Particle size: The suspensions prepared in each example and comparative example were immediately subjected to particle size testing. The specific steps are as follows: The suspension sample was dropped into a laser particle size analyzer for automatic testing to obtain the initial particle size D90; then the suspension was placed at 54℃ and 65℃ for 14 days respectively, and the heat storage particle size D90 at 54℃ and 65℃ was measured as above; similarly, the suspension was placed at 0℃ for 7 days and the particle size D90 at 0℃ was measured.

[0059] (7) Wet sieving: The wet sieving test was conducted according to GB / T 16150-2025 "Test Methods for Screening of Pesticides". 10g of freshly prepared suspensions from each example and comparative example, as well as those that had undergone the above-mentioned heat and cold storage, were placed in a 250mL beaker. 100mL of tap water was added, and the mixture was allowed to stand for 60s. Then, it was stirred with a magnetic stirrer for 5min. The wetted sample was transferred to the test sieve and rinsed with tap water. The magnetic stirrer was removed and rinsed with a gentle stream of tap water through a 10mm inner diameter rubber tube. The water flow rate was controlled at 1-5L / min, maintaining a distance of 2cm-5cm between the water flow and the test sieve surface. The residue on the sieve wall was washed onto the sieve surface, and the residue was flushed together with water. Rinsing continued until the amount of visible residue remained constant (maximum 10min). The tap water was then removed from the edge of the sieve. If no visible residue was found, the test was stopped, and weighing was not required. The wet screening pass rate w1 is calculated according to the formula w1=(m1-m2) / m1)×100%, where m1 is the sample mass of the suspension and m2 is the mass of the residue.

[0060] 2. Test Results (1) pH and persistent foaming properties Table 1 Results of pH and persistent foaming tests

[0061] As shown in Table 1, the suspending agents provided in Examples 1-8 have suitable pH and persistent foaming properties.

[0062] (2) Initial content and suspension rate Table 2. Results of Initial Content and Suspension Rate Tests

[0063] From Table 2, Figure 1 and Figure 2 It can be seen that the suspension rates of Examples 1-8 are significantly better than those of the comparative examples, with Example 1 having the highest suspension rate. Figure 1 It can also be observed that there is no obvious stratification and the suspension effect is good. In contrast, the wetting and dispersion effects of Comparative Examples 1-3, after omitting or replacing the wetting agent, are significantly inferior to those obtained by using the wetting agent with a specific HLB value range in this application. The above results indicate that the suspending agent using a wetting agent with a specific HLB value range and the specific preparation method provided by this invention can significantly improve the suspension rate of the suspending agent.

[0064] (3) Stability Table 3 Results of thermal storage stability test at 54℃

[0065] Table 4. Results of thermal storage stability test at 65℃

[0066] Table 5 Results of Cold Storage Stability Test

[0067] As shown in Tables 3-5, the suspension rates of Examples 1-8 after hot and cold storage were significantly better than those of the comparative examples. In Comparative Examples 1-3, omitting or replacing the wetting agent resulted in decreased wetting and dispersion effects at both high and low temperatures. In Comparative Example 4, the xanthan gum thickener was added entirely before sand milling, reducing its thickening ability and leading to a decrease in the suspension rate, which further decreased at both high and low temperatures. These results demonstrate that the suspensions using wetting agents within a specific HLB value range and the specific preparation method provided by this invention can significantly improve the stability of the suspensions under both hot and cold storage conditions, ensuring the quality of the suspensions.

[0068] (4) Particle size Table 6. Particle size test results

[0069] When two low-melting-point active ingredients are combined and heat-stored into a suspension, the particle size tends to increase, and the higher the temperature, the larger the particle size. Table 6 shows that the particle size of Examples 1-8 is significantly smaller than that of the comparative examples after heat storage. In Comparative Examples 1-3, omitting or replacing the wetting agent resulted in significantly inferior wetting and dispersion effects compared to the application using a wetting agent with a specific HLB value range, leading to increased particle size after heat storage and a higher likelihood of crystallization and precipitation. These results demonstrate that the suspension provided by this invention, using a wetting agent with a specific HLB value range, can significantly reduce the particle size of the suspension.

[0070] (5) Wet sieving Table 7 Wet Screening Rate Test Results

[0071] As shown in Table 7, after wet sieving of the suspensions prepared in each embodiment and comparative example, Examples 1-8 showed no stratification, water separation, or residual particles, thus better maintaining the physical stability of the product during storage, significantly superior to the comparative examples. In Comparative Examples 1-3, omitting or replacing the wetting agent resulted in significantly inferior wetting and dispersion effects compared to those obtained using the wetting agent within the specific HLB value range in this application. This led to increased particle size and crystal precipitation after heat storage, resulting in a significant decrease in wet sieving pass rate. These results demonstrate that the suspensions using wetting agents within a specific HLB value range and the specific preparation method provided by this invention can significantly improve the suspension rate of the suspensions.

[0072] Experimental Example 2: Indoor Efficacy Test 1. Test conditions 1.1 Test Target The tea green leafhopper (Empoascaonukii Matsuda) was collected from damaged tea trees in Qingxi Town, Hanshan County, Ma'anshan City, Anhui Province. The tea trees were covered with a net, and adult leafhoppers were collected using a suction device. The following methods were used to cultivate 2-3 generations before the experiment was conducted.

[0073] This study describes a method for indoor rearing of the tea green leafhopper. A 2% potassium nitrophenolate solution and repeatedly pruned potted tea seedlings were used as rearing materials to ensure continuous bud production throughout the year. Adult tea green leafhoppers were collected and transferred to rearing cages containing fresh tea shoots, allowing them to mate and lay eggs naturally. The rearing cages were placed in a rearing room with a daytime temperature of 20–26°C, a nighttime temperature of 18–22°C, a relative humidity of 60%–80%, and a natural light cycle. Egg-laying tea shoots were collected and transferred to new rearing cages, which were then placed on fresh potted tea seedlings for hatching. As nymphs hatched from the eggs, new tea seedlings were added as needed based on the feeding activity. The room temperature was maintained at 24–26°C throughout the day, with a relative humidity of 80%–90% and a natural light cycle. This rearing process continued until the adults emerged, at which point the next rearing cycle began.

[0074] 1.2 Test Materials Fresh tea tree buds. Collected from potted tea seedlings cultivated in an experimental greenhouse; the seedlings were purchased from the market.

[0075] 2 Experimental Design 2.1 Test reagents 98.8% pyriproxyfen technical grade, 98% acetamiprid technical grade.

[0076] 2.2 Composition Proportion Design Pyriproxyfen: Azoxystrobin = 1:1, 1:2, 1:3, 1:4, 1:5.

[0077] 2.3 Dosage of the drug:

[0078] 2.4 Drug Preparation Weigh out a certain amount of the original drug and dissolve it separately in acetone to form a mother liquor. Dilute the single-dose formulation with a 0.1% (w / w) Tween-80 aqueous solution to the highest concentration designed in the table above. For the composition, first dilute the single-dose mother liquor with a 0.1% (w / w) Tween-80 aqueous solution to the same concentration (i.e., the highest concentration of the composition shown in the table above), then mix them by volume according to the composition ratio designed in 2.2. Dilute the single-dose formulation and the composition using a gradient dilution method, setting up 5 series doses (as shown in the table above). A blank control was set up containing only acetone and Tween-80 and no active ingredient.

[0079] 2.5 Sample Preparation Pick fresh tea tree buds and shoots for later use.

[0080] 2.6 Test Methods 2.6.1 Chemical treatment Immerse the prepared tea buds in a beaker containing the above-mentioned medicinal solution for 20 seconds, then remove and place them on a petri dish lined with filter paper to air dry naturally in a cool place. After drying, transfer them to centrifuge tubes for later use. During treatment, first process the blank control, then process the single-dose agents in order of increasing concentration, and finally process the combined agent. Mark the petri dish and centrifuge tube immediately after each treatment.

[0081] 2.6.2 Inoculation Use a siphon to collect uniformly growing third-instar leafhopper nymphs cultured indoors. Then, treat them at a low temperature for a short period to reduce their mobility and prevent escape during collection. After treatment, sweep the nymphs from the siphon into centrifuge tubes using a brush. Seal the centrifuge tubes with gauze and place them at 24-26℃, 80%-90% relative humidity, and natural light cycles for rearing and observation. Supplement with fresh, untreated tea tree buds as needed.

[0082] 2.7 Experimental Replication Each treatment involves 20 heads and is repeated 4 times.

[0083] 3. Observations and Statistical Analysis 3.1 Results Observation After 7 days of experimentation, the results were observed. The mortality rate was checked by gently touching the insects with a brush. Insects that did not attempt to escape, twitch, or struggle were considered dead. The total number of insects and the number of dead insects were recorded. A mortality rate of less than 10% was considered a valid experiment.

[0084] 3.2 Calculation of drug efficacy

[0085]

[0086] 3.3 Regression Analysis Regression analysis was performed on the results using DPS18.10 software to derive the toxicity equation and LC ratio. 50 LC 90 and its confidence interval.

[0087] 3.4 Calculation of Co-toxicity Coefficient The co-toxicity coefficient (CTC) of the mixture was calculated using the co-toxicity coefficient method calculated by Sun Yunpei, and the synergistic effect of the mixture was determined.

[0088] Using a single agent from the mixture as the standard reagent (usually selected by LC) 50 (The lower one), calculate: Single-dose toxicity index = (LC50 of standard agent) 50 A single-dose LC 50 )×100.

[0089] Theoretical Toxicity Index (TTI) = Toxicity index of single agent A × Proportion of single agent A in the mixture + Toxicity index of single agent B × Proportion of single agent B in the mixture

[0090] Actual Toxicity Index (ATI) = (LC of a standard single dose) 50 LC of values / mixtures 50 (value) × 100.

[0091] Co-toxicity coefficient = (measured toxicity index / theoretical toxicity index) × 100.

[0092] When CTC is greater than or equal to 120, the mixture has a synergistic effect; when CTC is less than or equal to 80, it has an antagonistic effect; and when CTC is between 80 and 120, it has an additive effect.

[0093] 4 Results and Analysis Table 8 Results of indoor efficacy tests (using pyriproxyfen as the standard reagent)

[0094] Table 8 shows that compositions of pyriproxyfen and acetamiprid at ratios of 1:1, 1:4, and 1:5 exhibit additive effects, while compositions at ratios of 1:2 and 1:3 show synergistic effects, with co-toxicity coefficients of 140.37 and 158.15, respectively. These two compounds can be mixed. The 1:3 composition shows higher activity against the tea green leafhopper.

[0095] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A suspension concentrate containing pyriproxyfen and azoxystrobin, characterized in that, The product comprises, by weight percentage, the following components: pyriproxyfen 5%-30%, azoxystrobin 5%-30%, dispersant 2%-10%, wetting agent 1%-3%, thickener 0.3%-2%, antifreeze 3%-7%, defoamer 0.1%-0.8%, mildew inhibitor 0.05%-0.2%, with the balance being water; the hydrophilic-lipophilic balance value of the wetting agent is 7-12.

2. The suspension concentrate containing pyriproxyfen and azoxystrobin according to claim 1, characterized in that, The dispersant includes at least one of lignin sulfonate, naphthalene sulfonate formaldehyde condensate, and polycarboxylate.

3. The suspension concentrate containing pyriproxyfen and azoxystrobin according to claim 1, characterized in that, The wetting agent includes at least one of block polyether and polyoxyethylene ether sulfate, preferably block polyether.

4. The suspension concentrate containing pyriproxyfen and azoxystrobin according to claim 1, characterized in that, The thickener includes at least one of xanthan gum, silica, magnesium aluminum silicate, and sepiolite; preferably sepiolite and xanthan gum. Optionally, the mass ratio of sepiolite to xanthan gum is 3-8:1, preferably 4-7.5:

1.

5. The suspension concentrate containing pyriproxyfen and azoxystrobin according to claim 1, characterized in that, The antifreeze agent includes at least one of ethylene glycol, propylene glycol, glycerol, polyethylene glycol, and urea. And / or, the defoamer includes at least one of organosilicon defoamers, silicone defoamers, fatty acid defoamers, and fatty alcohol defoamers; preferably, it is an organosilicon defoamer; And / or, the antifungal agent includes at least one of isothiazolinone, Kathon, benzoic acid and its salts, sorbic acid and its salts; preferably isothiazolinone.

6. The suspension concentrate containing pyriproxyfen and azoxystrobin according to claim 1, characterized in that, The mass ratio of acetamiprid to pyriproxyfen is 1:5-5:

1.

7. The suspension concentrate containing pyriproxyfen and acetamiprid according to claim 1, characterized in that, The dispersant comprises a polycarboxylate and an alkylnaphthalene sulfonate formaldehyde condensate; Optionally, the mass ratio of the polycarboxylate and alkylnaphthalene sulfonate formaldehyde condensate is 1:0.5-2, preferably 1:1.

5.

8. The method for preparing the suspension containing pyriproxyfen and acetamiprid according to any one of claims 1-7, characterized in that, Includes the following steps: Pyriproxyfen, azoxystrobin, dispersant, wetting agent, antifreeze, a portion of defoamer, mildew inhibitor, a portion of thickener, and water are mixed, homogenized, and then ground. Another portion of defoamer and another portion of thickener are added, and the mixture is homogenized a second time to obtain a suspension containing pyriproxyfen and azoxystrobin.

9. The preparation method according to claim 8, characterized in that, The mixing speed is 300-1000 rpm, and the time is 10-30 min; And / or, the homogenization is carried out at a rotation speed of 500-2000 rpm, a temperature of 15-30°C, and a time of 15-45 min; And / or, the grinding speed is 1000-2000 rpm; And / or, the particle size D90 is controlled to be less than 5 μm during the grinding process; And / or, the rotation speed of the secondary homogenization is 500-1000 rpm, and the temperature is 15-30℃; And / or, the mass ratio of one part of the defoamer to another part of the defoamer is 1:3-2:1; And / or, the mass ratio of one part of the thickener to another part of the thickener is 1:5 to 1:

3.

10. The application of the suspension concentrate containing pyriproxyfen and azoxystrobin according to any one of claims 1-7 or the suspension concentrate containing pyriproxyfen and azoxystrobin prepared by the preparation method according to claim 8 or 9 in the control of pests; optionally, the pests include at least one of tea green leafhopper, cabbage caterpillar, beet armyworm, cotton bollworm, whitefly, thrips, cotton bollworm, pear psyllid, and scale insects.

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