A sanitary insecticide suspension and its preparation method

Abstract

The present invention relates to a sanitary insecticidal suspension concentrate and a preparation method thereof. The suspension concentrate comprises the following components in parts by weight: 0.1-40% of an active ingredient, 1.0-10% of a wetting agent, 1.0-10% of a dispersant, 0.05-10% of a thickener, 1.0-10% of an antifreeze agent, 0.1-1.0% of a defoamer, 0.1-1.0% of a preservative, and water making up to 100%. The suspension concentrate is prepared by combining preferred auxiliary agents and shortening the sand milling time, so that the drug particles have a larger particle size, have excellent wetting and dispersing properties, and maintain good stability during long-term storage. The sanitary insecticidal suspension concentrate, which is difficult to stabilize, is made more stable by selecting auxiliary agents such as preferred wetting agents, dispersants, and thickeners.

Description

Technical Field

[0001] The invention relates to the field of sanitary insecticides, in particular to a large-particle sanitary insecticide suspension containing pyrethroids, a preparation method and application thereof. Background Art

[0002] Pyrethroid pesticides are synthetic insecticides that mimic natural pyrethrins. Their broad spectrum of activity, high efficacy, low residual activity, and lack of accumulation have led to their widespread use over the past 30 years. In addition to combating agricultural pests, they have also achieved considerable success against pests of vegetables and fruit trees, as well as public health pests such as mosquitoes, flies, cockroaches, and head lice.

[0003] Suspension concentrates (SCs) are a viscous, flowable suspension formed by mixing the pesticide active ingredient with a carrier and a dispersant through wet ultrafine grinding. The insoluble or slightly soluble solid SC is dispersed relatively evenly in the water medium through ultrafine grinding with the aid of certain additives, forming a stable, highly suspended, flowable liquid-solid system with fine particles. SCs typically consist of the active ingredient, a dispersant, a thickener, an anti-precipitant, a defoamer, an antifreeze, and water. The processing of SCs places specific demands on pesticides: the SC must have low solubility in water, and the melting point of the solid SC system should ideally be above 60°C. The SC must also possess good chemical stability in water and resist hydrolysis or decomposition. The active ingredient content in pesticide SCs is generally 5% to 50%. Generally speaking, finer particle size results in more uniform distribution and a higher suspension efficiency. In my country, the suspension efficiency fineness is generally controlled at around 1-5 μm.

[0004] CN101953368A discloses a composition containing chlorofluoroether polyester and high-efficiency cypermethrin, which is used to make mosquito coils or insecticide aerosols for preventing and controlling sanitary pests.

[0005] CN102630699A discloses a compound insecticide containing dextrorotatory trans-chlorpropamide and a compound insecticide, wherein the compound insecticide may be a lethal pyrethroid compound such as highly effective cypermethrin, deltamethrin, etc., for preventing and controlling sanitary pests.

[0006] CN107372578A discloses a sanitary insecticide suspoemulsion, which contains knockdown pyrethroids such as d-trans-chlorpromazine, chlorflumethrin, transfluthrin, tefluthrin, metofluthrin, transfluthrin or transfluthrin, and lethal pyrethroids such as beta-cypermethrin, cis-cypermethrin, beta-cypermethrin, beta-cyfluthrin, beta-cyhalothrin, deltamethrin or bifenthrin, and is used for controlling sanitary pests.

[0007] CN114903050A discloses an insecticide composition containing chlorfenapyr and beta-cypermethrin, which can be prepared into water-dispersible granules and suspensions for preventing and controlling sanitary pests.

[0008] CN114342953A discloses a rain-resistant deltamethrin suspension, which contains deltamethrin, a wetting agent, a dispersant, a synergist, a thickener, a preservative, an antifreeze agent, a suspending agent, a defoaming agent, and the balance is water.

[0009] CN112056322A discloses a sanitary insecticidal composition containing chlorpyrifos, which contains chlorpyrifos and a specific knockdown fluorine-containing pyrethroid. Compared with a single dose, the composition has an unexpected toxicity enhancement effect and improves the insecticidal effect.

[0010] Prior art has studied the use of pyrethroids, or pyrethroid combinations, against pests, including the preparation of suspension concentrates. However, in practice, it has been found that appropriately increasing the particle size of the suspension concentrate drug particles can prevent more drug particles from penetrating the target surface and penetrating into the target interior, thereby allowing more drug particles to be deposited on the target surface, achieving better control effects. Therefore, compared with ordinary suspension concentrates, these agents have better long-term retention activity and faster knockdown activity, making them very suitable for indoor and outdoor pest control. However, the drug particles are large in size, and the suspension rate decreases after long-term storage. Therefore, there is an objective need to find an excellent large-particle suspension concentrate formula that is conducive to the stability of the formulation system and the full realization of the drug efficacy. Summary of the Invention

[0011] The purpose of the present invention is to overcome the problems existing in the prior art, develop a suspension concentrate with large particle size and good formulation stability through the screening of specific auxiliary agents, solve the problem of decreased quality indicators such as suspension rate, and thus achieve product stability and good prevention and control effects.

[0012] The present invention is accomplished through the following technical solutions.

[0013] One aspect of the present invention relates to a large-particle hygienic insecticidal suspension concentrate, wherein the components and their mass percentages in the large-particle hygienic insecticidal suspension concentrate are as follows:

[0014]

[0015] The mass percentage of each component is preferably:

[0016]

[0017] The mass percentage of each component is more preferably:

[0018]

[0019]

[0020] In the large-particle sanitary insecticide suspension formulation described in the present application, the active ingredients include lethal pyrethroids and knockdown pyrethroids. The lethal pyrethroid is selected from one or both of beta-cypermethrin and cis-cypermethrin. The knockdown pyrethroid is selected from one or more of D-trans chlorpropargyl, cypermethrin, and chlorpyrifos. Specific combinations include, but are not limited to: beta-cypermethrin + D-trans chlorpropargyl, beta-cypermethrin + cypermethrin, beta-cypermethrin + chlorpyrifos, cis-cypermethrin + D-trans chlorpropargyl, cis-cypermethrin + cypermethrin, and cis-cypermethrin + chlorpyrifos. Wherein, the ratio of the lethal pyrethroid to the knockdown pyrethroid can be 1:20-20:1, preferably 1:10-10:1, for example, 10:1, 9:1, 8:1, 7:1, 6:1, 5:1, 4:1, 3:1, 2:1, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10.

[0021] In one embodiment of the present invention, the wetting agent is selected from polymer block polyether wetting agents, preferably one or more of Emulsogen 3510, Atlox 4894, Ethylan NS 500LQ, and ANTAROX BL-759, more preferably Ethylan NS 500LQ or ANTAROX BL-759, and most preferably ANTAROX BL-759.

[0022] In one embodiment of the present invention, the dispersant is selected from phosphates and polycarboxylates, preferably a combination of phosphates and polycarboxylates. The phosphate dispersant is preferably selected from one or more of Soprophor SC, SP-SC3060, Dispersogen LFS, and YUS-FS3000; and the polycarboxylate dispersant is preferably selected from one or more of GEROPONT / 36, Agrilan 752, SP-2728, and GY-D06. More preferably, the combination of dispersants includes: Soprophor SC+GEROPON T / 36, Soprophor SC+Agrilan 752, Soprophor SC+SP-2728, Soprophor SC+GY-D06, SP-SC3060+GEROPON T / 36, SP-SC3060+Agrilan752, SP-SC3060+SP-2728, SP-SC3060+GY-D06, Dispersogen LFS+GEROPON T / 36, Dispersogen LFS+Agrilan752, Dispersogen LFS+SP-2728, Dispersogen LFS+GY-D06, YUS-FS3000+GEROPON T / 36, YUS-FS3000+Agrilan 752, YUS-FS3000+SP-2728, YUS-FS3000+GY-D06. Preferred are the combinations of Soprophor SC+GEROPON T / 36, Soprophor SC+Agrilan 752, SP-SC3060+Agrilan 752, Dispersogen LFS+GEROPON T / 36, Dispersogen LFS+SP-2728, YUS-FS3000+SP-2728, and YUS-FS3000+GY-D06. More preferred are the combinations of YUS-FS3000+GY-D06 or YUS-FS3000+SP-2728.

[0023] The weight ratio of the above-mentioned phosphate dispersant to the polycarboxylate dispersant is 1:10-10:1, preferably 1:5-5:1, more preferably 1:2.5-2.5:1, for example, 1:2.5, 1:2, 1:1.5, 1:1, 1:1.5, 1:2, 1:2.5; and most preferably 2.5:1.

[0024] In one embodiment of the present invention, the thickener is selected from one or two of xanthan gum and polyvinyl alcohol (PVA-1788, PVA-2088, PVA-2488), preferably a combination of xanthan gum and polyvinyl alcohol (PVA-1788, PVA-2088, PVA-2488), and the weight ratio of the two is 1:5-5:1, preferably 1:3-3:1, and more preferably 7:3.

[0025] The antifreeze agent is selected from one or more of ethylene glycol, propylene glycol, glycerol and urea.

[0026] The defoaming agent is selected from one or more of silicone oils, silicone compounds, C10-20 saturated fatty acids and their esters, and C8-12 fatty alcohol defoaming agents.

[0027] The preservative is selected from one or more of potassium sorbate, sodium benzoate, sodium diacetate, sodium dehydroacetate, kasone, bronopol and the like.

[0028] The present invention obtains a suitable compatibility of auxiliary agents through preliminary screening and formula screening of auxiliary agents such as wetting agents, dispersants, and thickeners, solves the technical contradiction that an increase in particle size in a suspension concentrate leads to deterioration of suspension stability, and prepares a large-particle suspension concentrate formula with excellent quality indicators such as suspension rate and stability. The particle size D90 of the large-particle suspension concentrate is between 15 and 20 μm, which is significantly larger than that of conventional suspension concentrates. In addition, efficacy tests have shown that the large-particle suspension concentrate is more effective than conventional suspension concentrates in specific fields such as sanitation and insecticide.

[0029] Another aspect of the present invention relates to a method for preparing the large-particle sanitary insecticide suspension concentrate, which comprises the following steps:

[0030] a. Mix the active ingredient with the wetting agent, dispersant, thickener, antifreeze agent, defoaming agent, preservative and appropriate amount of water according to the formula ratio and shear thoroughly until uniform;

[0031] b. Grind the mixture obtained above to a particle size D90 between 15-20 μm, and then filter it out.

[0032] Specifically, in the method for preparing a large-particle sanitary insecticide suspension according to the present invention, the temperature is preferably controlled below 40° C. during the grinding process.

[0033] Another aspect of the present invention relates to the use of the large-particle sanitary insecticidal suspension concentrate. Specifically, it can be used to control pests such as cockroaches, fleas, ants, bedbugs, mosquitoes, and flies. It is preferably used on absorbent surfaces, such as cement and lime surfaces. The specific application method and dosage are within the skill of one skilled in the art based on actual conditions.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] (1) Compared with conventional particle size suspension concentrates, the large particle size sanitary insecticidal suspension concentrate of the present invention has better long-term residual activity and better rapid knockdown activity.

[0036] (2) The present invention forms a stable super network structure by selecting auxiliary agents such as wetting agents, dispersants, and thickeners, so that the suspension does not precipitate water or stratify during long-term storage, the system is uniform, and the solid particles are not easily aggregated and Ostwald ripened.

[0037] (3) The present invention adds a new dosage form to the domestic sanitary insecticide field, has significant efficacy, and can be widely promoted and applied. DETAILED DESCRIPTION

[0038] The present invention will be further described below with reference to specific examples, but the present invention is not limited to these specific embodiments.

[0039] Unless otherwise specified, the experimental methods used in the following examples are conventional methods; the reagents, materials, etc. used in the following examples are all commercially available unless otherwise specified.

[0040] Emulsogen 3510 and Dispersogen LFS used in the following examples were purchased from Clariant, Atlox 4894 was purchased from Croda, Ethylan NS 500LQ and Agrilan 752 were purchased from Akzo Nobel, ANTAROX BL-759, Soprophor SC, and GEROPON T / 36 were purchased from Solvay, SP-SC3060 and SP-2728 were purchased from Qingyu, YUS-FS3000 was purchased from Takemoto Oils & Fats Co., Ltd., and GY-D06 was purchased from Guangyuan Yinong. All other raw materials were readily available on the market.

[0041] (1) Initial screening of wetting agents and dispersants

[0042] The flow point method is used to conduct preliminary screening of wetting agents and dispersants.

[0043] Specific wetting agents tested include: Emulsogen 3510, Atlox 4894, Ethylan NS500LQ, ANTAROX BL-759, SP-1600P;

[0044] Specific dispersants tested include: Soprophor SC, SP-SC3060, Dispersogen LFS, YUS-FS3000, GEROPON T / 36, Agrilan 752, SP-2728, GY-D06, FTRT DS523, SD-661;

[0045] The specific testing method is as follows: First, various wetting agents and dispersants are prepared into 5% aqueous solutions and set aside. Then, 2.0g of ground cypermethrin stock is weighed and added to a 20mL beaker and weighed. Afterwards, the above-prepared aqueous solution is added dropwise while mixing with ultrasound until the paste just slides down the beaker wall. Then, the addition is stopped and the beaker is weighed again. The mass of the aqueous solution used is calculated (the difference between the two weighing masses), and the average value of these three repetitions is taken. Then, the mass of the solution used per unit mass of cypermethrin is calculated, which is the pour point value of the wetting and dispersing agent for the tested stock. The specific calculation method is shown in the following formula (I).

[0046]

[0047] The initial screening results of the above wetting agents are shown in Table 1 below.

[0048] Table 1 Wetting agent initial screening results

[0049] Serial number Wetting agent Pour point (g / g) 1 Emulsogen 3510 0.74 2 Atlox 4894 0.79 3 Ethylan NS 500LQ 0.69 4 ANTAROX BL-759 0.63 5 SP-1600P 1.35

[0050] The screening results showed that Emulsogen 3510, Atlox 4894, Ethylan NS 500LQ, and ANTAROX BL-759 had smaller flow points, all lower than 0.8, which were favorable; among them, Ethylan NS500LQ and ANTAROX BL-759 were more preferred, and ANTAROX BL-759 was most preferred.

[0051] The preliminary screening results of the above dispersants are shown in Table 2 below.

[0052] Table 2 Dispersant initial screening results

[0053] Serial number dispersants Pour point (g / g) Serial number dispersants Pour point (g / g) 1 Soprophor SC 0.95 6 Agrilan 752 0.94 2 SP-SC3060 0.92 7 SP-2728 0.82 3 Dispersogen LFS 0.89 8 GY-D06 0.91 4 YUS-FS3000 0.86 9 FTRT DS523 1.36 5 GEROPON T / 36 0.93 10 SD-661 1.45

[0054] Screening results showed that FTRT DS523 and SD-661 had high flow points, both greater than 1.3, which was unfavorable. The flow points of the remaining dispersants were all between 0.8 and 1, but were not ideal. Therefore, further screening of dispersant combinations was conducted.

[0055] Based on the above preliminary screening results, various combinations of phosphate dispersants and polycarboxylate dispersants (the mass ratio of the two is 2.5:1) were further screened, and the results are shown in Table 3 below.

[0056] Table 3 Dispersant combination screening results

[0057]

[0058] Among the above-mentioned combinations of phosphate dispersants and polycarboxylate dispersants, the pour points of the combinations of Soprophor SC+GEROPON T / 36, Soprophor SC+Agrilan 752, SP-SC3060+Agrilan 752, Dispersogen LFS+GEROPON T / 36, Dispersogen LFS+SP-2728, YUS-FS3000+SP-2728, and YUS-FS3000+GY-D06 are lower than 0.8, and are more preferred; further, the combinations of YUS-FS3000+SP-2728 and YUS-FS3000+GY-D06 are more preferred; among them, the combination of YUS-FS3000+GY-D06 is most preferred.

[0059] (2) Preparation Examples

[0060] According to the above screening results, the following formulations were prepared. Unless otherwise specified, the percentages in the present invention are all by weight.

[0061] Example 1: 10% cis-cypermethrin·cypermethrin large particle size sanitary insecticide suspension

[0062]

[0063]

[0064] The materials are mixed according to the formula ratio and sheared thoroughly and evenly, the mixture obtained above is ground to a particle size D90 between 15-20 μm, and then filtered out to obtain the product.

[0065] Example 2: 10% highly effective cypermethrin-cypermethrin large particle size sanitary insecticide suspension

[0066]

[0067] The materials are mixed according to the formula ratio and sheared thoroughly and evenly, the mixture obtained above is ground to a particle size D90 between 15-20 μm, and then filtered out to obtain the product.

[0068] Example 3: 10% cis-cypermethrin and D-trans-chlorprophmethrin large particle size sanitary insecticide suspension

[0069]

[0070] The materials are mixed according to the formula ratio and sheared thoroughly and evenly, the mixture obtained above is ground to a particle size D90 between 15-20 μm, and then filtered out to obtain the product.

[0071] Example 4: 10% highly effective cypermethrin-dextran-chlorprophmethrin large particle size sanitary insecticide suspension

[0072]

[0073]

[0074] The materials are mixed according to the formula ratio and sheared thoroughly and evenly, the mixture obtained above is ground to a particle size D90 between 15-20 μm, and then filtered out to obtain the product.

[0075] Example 5: 10% highly effective cypermethrin-chlorfenapyr large particle size sanitary insecticide suspension

[0076]

[0077] The materials are mixed according to the formula ratio and sheared thoroughly and evenly, the mixture obtained above is ground to a particle size D90 between 15-20 μm, and then filtered out to obtain the product.

[0078] Example 6: 10% cis-cypermethrin-chlorfenapyr large particle size sanitary insecticide suspension

[0079]

[0080]

[0081] The materials are mixed according to the formula ratio and sheared thoroughly and evenly, the mixture obtained above is ground to a particle size D90 between 15-20 μm, and then filtered out to obtain the product.

[0082] Example 7: 10% highly effective cypermethrin-dextran-chlorprophmethrin large particle size sanitary insecticide suspension

[0083]

[0084] The materials are mixed according to the formula ratio and sheared thoroughly and evenly, the mixture obtained above is ground to a particle size D90 between 15-20 μm, and then filtered out to obtain the product.

[0085] Example 8: 10% cis-cypermethrin·cypermethrin large particle size sanitary insecticide suspension

[0086]

[0087] The materials are mixed according to the formula ratio and sheared thoroughly and evenly, the mixture obtained above is ground to a particle size D90 between 15-20 μm, and then filtered out to obtain the product.

[0088] Comparative Example 1: 10% highly effective cypermethrin·dextrorotatory trans-chlorpropamide suspension concentrate

[0089]

[0090]

[0091] The materials are mixed according to the formula ratio and sheared thoroughly and evenly, the mixture obtained above is ground to a particle size D90 between 15-20 μm, and then filtered out to obtain the product.

[0092] Comparative Example 2: 10% cis-cypermethrin-chlorfenapyr suspension concentrate

[0093]

[0094] The materials are mixed according to the formula ratio and sheared thoroughly and evenly, the mixture obtained above is ground to a particle size D90 between 15-20 μm, and then filtered out to obtain the product.

[0095] Comparative Example 3: 10% highly effective cypermethrin-dextran-chlorpropamide suspension concentrate

[0096]

[0097]

[0098] The materials are mixed according to the formula ratio and sheared thoroughly and evenly, the mixture obtained above is ground to a particle size D90 between 15-20 μm, and then filtered out to obtain the product.

[0099] Comparative Example 4: 10% cis-cypermethrin·cypermethrin suspension concentrate

[0100]

[0101] The materials are mixed according to the formula ratio and sheared thoroughly and evenly, the mixture obtained above is ground to a particle size D90 between 15-20 μm, and then filtered out to obtain the product.

[0102] Comparative Example 5: 10% highly effective cypermethrin-chlorfenapyr suspension concentrate

[0103]

[0104]

[0105] The materials are mixed according to the formula ratio and sheared thoroughly and evenly, the mixture obtained above is ground to a particle size D90 between 15-20 μm, and then filtered out to obtain the product.

[0106] Comparative Example 6: 10% highly effective cypermethrin-dextran-chlorpropamide suspension concentrate

[0107] The preparation process is the same as that of Example 4, except that the mixed solution is ground to a particle size D90 of about 3.0 μm.

[0108] The quality control indicators of the above examples and comparative examples were tested according to the following methods: 1. The mass fraction of the active ingredient was determined by high performance liquid chromatography; 2. The pH was determined according to CIPAC MT 75.3; 3. The suspension rate was determined according to CIPAC MT 184; 4. The wet sieving test was performed according to CIPAC MT 185; 5. The persistent foaming property was determined according to CIPAC MT 47.2; 6. The heat storage stability was determined according to 2.3 of GB / T 19136-2003 (54°C, 14 days), with the post-heat storage data mainly testing the suspension rate and particle size; 7. The pourability was determined according to CIPAC MT 148.1.

[0109] The quality and technical indicators of the suspending agents of Examples 1-8 are shown in Table 4.

[0110] Table 4 Technical Specifications of Suspension Concentrates of Examples 1-8

[0111]

[0112]

[0113] The quality and technical indicators of the suspending agents of Comparative Examples 1-5 are shown in Table 5.

[0114] Table 5 Technical indicators of the quality of the suspension concentrates of comparative examples 1-5

[0115] Test indicators Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Test Basis Mass fraction of active ingredients 10.1 10.1 10.1 10.1 10.1 Liquid chromatography pH 6.7 7.3 7.1 7.1 6.8 CIPAC MT 75.3 Wet sieve test, ≥ 99 99 99 99 99 CIPAC MT 185 Long-lasting foaming, after 1 minute 20 15 20 25 25 CIPAC MT 47.2 dumping 3.8 3.5 3.3 3.4 3.3 CIPAC MT 148.1 Suspension rate before heat storage 92.5 88.1 82.1 82.4 75.4 CIPAC MT 184 Suspension rate after heat storage 90.1 86.3 79.4 79.1 72.1 CIPAC MT 184 Particle size before thermal storage, D90, μm 15.4 16.1 16.6 15.7 16.3 Laser particle size analyzer Particle size after thermal storage, D90, μm 19.3 18.1 17.9 17.1 18.7 Laser particle size analyzer

[0116] The above data show that Examples 1-8 exhibit excellent quality across various indicators, with Examples 4 and 6 being preferred, and Example 4 being the most preferred. This is primarily due to the minimal decrease in suspension rate and minimal particle size growth before and after heat storage in these examples, indicating superior heat storage stability. Correspondingly, in Comparative Examples 1-2, 4-5, changes in the wetting agent or dispersant resulted in deterioration in various indicators, such as heat storage stability. Similarly, in Comparative Examples 3 and 5, when the composite thickener of xanthan gum and polyvinyl alcohol was replaced with magnesium aluminum silicate, deterioration in various indicators, such as heat storage stability, was also observed. This comparison demonstrates the excellent stability of the formulation of the present application.

[0117] (3) Biological tests

[0118] Targets of control: Culex pipiens, housefly;

[0119] Test method: Residual spray test, according to GBT 13917.1-2009 Indoor efficacy test and evaluation of public health insecticides for pesticide registration Part 1: Residual spray test for sprays, the knockdown time KT is measured 30 days after the absorption surface is coated 50 and mortality rates.

[0120] Experimental treatment: The preparations of Examples 1-8 and Comparative Examples 1-6 were diluted 200 times with water to prepare a spray solution, and then the active ingredient was 20 mg / m 2 The white lime board was coated with the dosage and the knockdown time KT was measured 30 days after coating. 50 and 24-hour mortality rate.

[0121] The test results for Culex pipiens pallens and housefly are shown in Tables 6-7 below.

[0122] Table 6 Results of the efficacy test on Culex pipiens pallens

[0123]

[0124] Table 7 Results of housefly efficacy test

[0125]

[0126]

[0127] The above embodiments are merely exemplary embodiments for illustrating the present invention, and the present invention is not limited thereto. Those skilled in the art should recognize that the present invention encompasses all possible alternatives, improvements, and equivalents within the scope of the claims.

Claims

1. A large particle size sanitary insecticidal suspension, characterized in that: The components and their mass percentages in the large-particle sanitary insecticide suspension are as follows: The active ingredients include lethal pyrethroids and knockdown pyrethroids, with a weight ratio of 1:10 to 10:1; and The lethal pyrethroid is selected from one or both of beta-cypermethrin and cis-cypermethrin; The knockdown pyrethroid is selected from one or more of d-trans chlorpromazine, cypermethrin, and chlorfenapyr; The wetting agent is selected from one or more of the polymer block polyether wetting agents Emulsogen 3510, Atlox4894, Ethylan NS500LQ, and ANTAROX BL-759; The dispersant is selected from a combination of phosphates and polycarboxylates, with the weight ratio of the two being 1:10-10:1; and The phosphate dispersant is selected from one or more of Soprophor SC, SP-SC3060, Dispersogen LFS, and YUS-FS3000; The polycarboxylate dispersant is selected from one or more of GEROPON T / 36, Agrilan 752, SP-2728, and GY-D06; The thickener is selected from a combination of xanthan gum and polyvinyl alcohol, and the weight ratio of the two is 1:5-5:1; The particle size D90 of the large-particle sanitary insecticide suspension is between 15 and 20 μm.

2. A large-particle sanitary insecticide suspension according to claim 1, characterized in that: The antifreeze agent is selected from one or more of ethylene glycol, propylene glycol, glycerol, and urea; The defoaming agent is selected from one or more of silicone compounds, C10-20 saturated fatty acids and their esters, and C8-12 fatty alcohol defoaming agents; The preservative is selected from one or more of potassium sorbate, sodium benzoate, sodium diacetate, sodium dehydroacetate, kasone, and bronopol.

3. A method for preparing a large-particle sanitary insecticide suspension according to any one of claims 1 to 2, characterized in that: The method comprises the following steps: a. Mix the active ingredient with the wetting agent, dispersant, thickener, antifreeze agent, defoaming agent, preservative and appropriate amount of water according to the formula ratio and shear thoroughly until uniform; b. Grind the mixture obtained above to a particle size D90 between 15-20 μm, and then filter it out.

4. The method for preparing a large-particle sanitary insecticide suspension according to claim 3, wherein: The temperature was controlled below 40°C during the grinding process.

5. The use of a large-particle sanitary insecticide suspension according to any one of claims 1 to 2, characterized in that: Used for absorbing surface to control sanitary pests.

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