Pesticide suspending agent containing thiophanate-methyl and trifloxystrobin and preparation method thereof

Abstract

The invention relates to the field of pesticide compositions, in particular to a pesticide suspending agent containing thiophanate-methyl and trifloxystrobin and a preparation method of the pesticide suspending agent. The pesticide suspending agent containing the thiophanate-methyl and the trifloxystrobin, provided by the invention, is prepared from the following raw materials in parts by mass: 5 to 6 parts of the trifloxystrobin, 40 to 42 parts of the thiophanate-methyl, 3 to 5 parts of a wetting dispersant, 2 to 3 parts of a dispersant, 1 to 3 parts of a wetting emulsifier, 1 to 2 parts of a suspending thixotropic agent, 3 to 5 parts of an anti-freezing agent, 0.1 to 0.3 part of a preservative, 0.1 to 0.3 part of a thickening agent, 0.1 to 0.3 part of a de-foaming agent and 35 to 45 parts of water. The pesticide suspending agent containing thiophanate methyl and trifloxystrobin provided by the invention is excellent in stability, low in irritation to crops and good in environmental compatibility, and has good popularization and application values.

Description

Technical Field

[0001] This invention relates to the field of pesticide compositions, and more particularly to a pesticide suspension containing thiophanate-methyl and azoxystrobin, and a method for preparing the same. Background Technology

[0002] In the field of agricultural pest and disease control, citrus resinosis (also known as scab) is one of the most important diseases affecting the development of the citrus industry, severely reducing fruit quality and yield. Currently, single fungicides on the market have limited control effects and are prone to causing pathogen resistance, making it difficult to meet the needs of modern agriculture for efficient and long-lasting disease control. Thiophanate-methyl, a broad-spectrum benzimidazole fungicide, works by inhibiting pathogen cell division; azoxystrobin, on the other hand, belongs to the methoxyacrylate class of fungicides and achieves its fungicidal effect by blocking pathogen respiration. Their mechanisms of action are different, providing a technical basis for their combined use.

[0003] Existing technologies already contain research on the combination of thiophanate-methyl and azoxystrobin. For example, patent CN102217617A discloses a pesticide composition containing azoxystrobin, whose active ingredients include azoxystrobin (A) and carbendazim or thiophanate-methyl (B), with a weight ratio ranging from 1:64 to 16:1. The total content of the active ingredients accounts for 1% to 90% of the total weight of the composition, preferably 10% to 80%. This patent also discloses that the composition can be prepared into various formulations such as wettable powder, water-dispersible granules, suspension concentrates, and emulsions, providing a technical reference for the combined application of thiophanate-methyl and azoxystrobin.

[0004] Although existing patents disclose compound formulations of thiophanate-methyl and azoxystrobin, there is still room for optimization in practical applications. On the one hand, current technologies do not offer specific compound formulations for citrus resinosis, lacking targeted data support. On the other hand, existing suspension formulations still have potential for improvement in terms of stability, dispersibility, and ease of field application. Furthermore, the current weight ratio range is relatively wide, and the optimal ratio for a specific disease has not been clearly defined, making it difficult to achieve the best balance between control efficacy and cost control. Therefore, there is an urgent need to develop a more targeted and higher-performance pesticide suspension containing thiophanate-methyl and azoxystrobin. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a pesticide suspension containing thiophanate-methyl and azoxystrobin. The raw materials for its preparation, by weight, include 5-6 parts azoxystrobin, 40-42 parts thiophanate-methyl, 3-5 parts wetting and dispersing agent, 2-3 parts dispersant, 1-3 parts wetting emulsifier, 1-2 parts suspending thixotropic agent, 3-5 parts antifreeze, 0.1-0.3 parts preservative, 0.1-0.3 parts thickener, 0.1-0.3 parts defoamer, and 35-45 parts water.

[0006] As an example of implementation, the mass concentration of the oxime ester is 97-99%.

[0007] As an example of implementation, the mass concentration of thiophanate-methyl is 97-99%.

[0008] Furthermore, the mass concentration of the oxime ester is 98%.

[0009] Furthermore, the mass concentration of the thiophanate-methyl is 98%.

[0010] Traditional single-agent fungicides easily lead to pathogen resistance and have limited control effects and short duration of action. This solution utilizes the synergistic mechanism of thiophanate-methyl and azoxystrobin to inhibit pathogens from different targets, solving the problems of "rapid resistance development and poor control effect of single agents" while extending the duration of action and reducing the number of applications. Meanwhile, existing suspension concentrates generally suffer from problems such as stratification, sedimentation, increased particle size after heat / cold storage, uneven dispersion, poor atomization, and weak resistance to rain washout. This solution addresses the core pain points of "unstable suspension systems and poor convenience of field use" by scientifically combining wetting and dispersing agents, dispersants, and thixotropic agents, combined with strict control of active ingredient purity. Some pesticide formulations, due to high levels of impurities in the active ingredient and high toxicity of adjuvants, are prone to causing phytotoxicity to crops and polluting soil and water environments. This solution uses high-purity active ingredients and low-toxicity, environmentally friendly adjuvants, solving the problems of "high risk of phytotoxicity and significant environmental impact," and meeting green pesticide standards.

[0011] As an example of implementation, the wetting and dispersing agent is a block polyether mixture.

[0012] Furthermore, the block polyether mixture is designated MALIDIS 1895 and is available from Shanghai Yijia New Materials Co., Ltd.

[0013] As an example of implementation, the dispersant is a polycarboxylate.

[0014] Furthermore, the polycarboxylate is designated Ultrasurf 7023A and is available from Wuxi Yijingfeng Technology Co., Ltd.

[0015] Ultrasurf 7023A dispersant can rapidly reduce the surface tension of two active pharmaceutical ingredient solid particles, promoting the full penetration of the aqueous medium to the particle surface and preventing the active pharmaceutical ingredient from agglomerating due to hydrophobicity, forming "oil floating" or "precipitation". At the same time, through the binding of hydrophilic groups with water and the adsorption of hydrophobic groups on the surface of the active pharmaceutical ingredient particles in the molecular structure, a stable double electric layer and steric hindrance effect are formed, effectively preventing the dispersed particles from re-aggregating and ensuring the long-term stability of the suspension system. On the other hand, it can significantly optimize the performance of the formulation, controlling the suspension rate to ≥90% in pesticide suspensions, reducing the viscosity of the formulation to avoid "paste formation" during storage, ensuring the stability of the formulation's performance within a 2-year shelf life, and the uniformly dispersed active pharmaceutical ingredient particles can make more full contact with the surface of citrus leaves and branches, reducing the problems of "missed spraying" or "localized phytotoxicity", and also improving the adhesion of the agent to the crop surface, extending the effective period by 1-3 days compared to ordinary dispersants.

[0016] As an example of implementation, the wetting emulsifier is a block copolymer.

[0017] Furthermore, the block copolymer is designated MALIDIS 550L and is available from Shanghai Yijia New Materials Co., Ltd.

[0018] MALIDIS 550L, as a specialized surfactant, effectively reduces the interfacial tension between thiophanate-methyl and azoxystrobin technical materials and the aqueous medium, rapidly improving the wettability of the technical material particles. It also emulsifies the hydrophobic technical materials, stably dispersing them in the aqueous system and preventing particle aggregation. This fundamentally solves stability problems such as "stratification" and "precipitation" that easily occur in suspension preparations, perfectly matching the requirements of the target formulation. Simultaneously, MALIDIS 550L significantly optimizes formulation performance. On one hand, it improves the overall dispersion uniformity of the formulation, ensuring that the technical material particles adhere evenly to the surface of citrus leaves and branches during field spraying, reducing the risk of phytotoxicity caused by "missed spraying" or "localized excessive concentrations." On the other hand, its excellent emulsification stability extends the formulation's shelf life, ensuring that the active ingredients do not degrade or stratify within the shelf life, maintaining stable efficacy.

[0019] As an example of implementation, the suspended thixotropic agent includes one of bentonite, fumed silica, or magnesium aluminum silicate.

[0020] Furthermore, the suspended thixotropic agent is magnesium aluminum silicate, model YH-ED, which can be purchased from Zhejiang Yuheng New Materials Co., Ltd.

[0021] Magnesium aluminum silicate possesses a unique layered crystal structure, enabling rapid dispersion in aqueous systems and the formation of a three-dimensional network gel structure. Upon standing, this structure significantly increases system viscosity, effectively supporting the solid particles of thiophanate-methyl and azoxystrobin technical, preventing sedimentation or stratification due to density differences. During stirring, the network structure is disrupted by shear force, rapidly reducing system viscosity and ensuring excellent flowability and atomization of the formulation, perfectly meeting the core requirements of suspension concentrates: "preventing sedimentation upon standing and easy flowability during use." Furthermore, magnesium aluminum silicate exhibits no antagonistic effect with raw materials such as Ultrasurf 7023A and MALIDIS 550L, synergistically enhancing the uniformity of technical dispersion and avoiding problems such as paste formation or demulsification caused by interactions between adjuvants.

[0022] As an implementable example, the antifreeze includes one of ethylene glycol, 1,2-propanediol, glycerol, sorbitol, polyethylene glycol, or sodium chloride.

[0023] Furthermore, the antifreeze is 1,2-propanediol.

[0024] 1,2-Propanediol has a freezing point as low as -59°C. The addition amount is usually 3%-5%, which can effectively reduce the freezing point of the suspension system, prevent freezing during low-temperature storage, prevent ice layer from damaging the dispersion state of the active pharmaceutical ingredient particles and the network structure of the adjuvants, ensure that the formulation can still maintain a uniform suspension state after thawing, and improve stability.

[0025] As an feasible example, the preservative includes one or more of benzisothiazolinone, methylisothiazolinone, chloromethylisothiazolinone, dimethyloldimethylhydantoin, or potassium sorbate.

[0026] Furthermore, the preservative is benzisothiazolinone.

[0027] As an example of implementation, the thickener includes one of xanthan gum, guar gum, carbomer, or sodium carboxymethyl cellulose.

[0028] Furthermore, the thickener is xanthan gum.

[0029] As an example of implementation, the defoamer is polydimethylsiloxane.

[0030] Furthermore, the polydimethylsiloxane is designated as SAG-1511 and is available from Momentive Advanced Materials Co., Ltd.

[0031] A second aspect of the present invention provides a method for preparing a pesticide suspension containing thiophanate-methyl and azoxystrobin, comprising the following steps: In a homogenizing reactor, wetting and dispersing agent, dispersant, wetting emulsifier, suspending thixotropic agent, antifreeze, preservative, defoamer and water are added in sequence. Then, oxadiazon and thiophanate-methyl are added and stirred into a uniform slurry. The slurry is then ground in a sand mill and a thickener is added and stirred evenly to obtain a pesticide suspension containing thiophanate-methyl and oxadiazon.

[0032] Beneficial effects (I) This invention is a precise compound formulation for citrus resinosis. Through the synergistic and complementary action mechanism of thiophanate-methyl and azoxystrobin, it effectively improves the inhibition rate of pathogens. The field control effect is 15%-25% higher than that of single active ingredient or conventional compound formulations, and the effective period is extended to 10-14 days, reducing the number of applications.

[0033] (II) Through the scientific combination of Ultrasurf 7023A, MALIDIS 550L and other adjuvants, combined with the suspension thixotropic effect of magnesium aluminum silicate and the antifreeze protection of 1,2-propanediol, the active ingredient decomposition rate is ≤3% and the suspension rate is ≥95% after the formulation is stored at 54℃ for 14 days and at 0℃ for 14 days. There is no stratification, precipitation or crystallization. The shelf life can reach 2 years.

[0034] (iii) The suspension formulation is evenly dispersed and has a good atomization effect. After spraying, it can quickly adhere to the surface of citrus leaves and branches and has strong resistance to rain washout. Moreover, the viscosity of the formulation is moderate, which avoids "missed spraying" and "running" during spraying, and will not affect atomization due to excessive viscosity. It is suitable for use with different spraying equipment.

[0035] (iv) The active ingredients selected in this invention, oxamyl ester and thiophanate-methyl, have high purity and few impurities. The adjuvants, such as low-toxicity 1,2-propanediol and natural mineral magnesium aluminum silicate, have extremely low irritation to citrus trees and no risk of phytotoxicity. At the same time, the formulation has good biodegradability and has little impact on the soil and water environment after field application, which meets the standards for green pesticide use.

[0036] (v) The optimized formula requires less additives and the raw material cost is controllable; the synergistic effect of additives during the sand milling process can shorten the grinding time by 10%-20% and reduce production energy consumption; at the same time, it reduces the number of times and the amount of pesticides used, thus reducing the overall planting cost for farmers. Attached Figure Description

[0037] Figure 1 This is a schematic diagram showing the appearance of the pesticide suspension in Example 1 after being stored at 54°C for 14 days.

[0038] Figure 2 This is a schematic diagram showing the appearance of pesticide suspension concentrate of Comparative Example 6 after being stored at 54℃ for 14 days. Detailed Implementation

[0039] Example 1 This example provides a pesticide suspension containing thiophanate-methyl and azoxystrobin, namely 45% thiophanate-methyl·azoxystrobin suspension. The raw materials for its preparation, by mass parts, include 5.1 parts 98wt% azoxystrobin, 41 parts 98wt% thiophanate-methyl, 3 parts wetting and dispersing agent, 3 parts dispersant, 2 parts wetting emulsifier, 1 part suspending thixotropic agent, 5 parts antifreeze, 0.2 parts preservative, 0.2 parts thickener, 0.2 parts defoamer, and 39.3 parts water.

[0040] The 98wt% oxadiazon and 98wt% thiophanate-methyl mentioned above are both from Xingnong Pharmaceutical (China) Co., Ltd.

[0041] The wetting and dispersing agent is a block copolymer, brand name MALIDIS 1895, purchased from Shanghai Yijia New Materials Co., Ltd.

[0042] The dispersant is a polycarboxylate, brand name Ultrasurf 7023A, purchased from Wuxi Yijingfeng Technology Co., Ltd.

[0043] The wetting emulsifier is a block copolymer, brand name MALIDIS 550L, purchased from Shanghai Yijia New Materials Co., Ltd.

[0044] The suspending thixotropic agent is magnesium aluminum silicate, brand name YH-ED, purchased from Zhejiang Yuheng New Materials Co., Ltd.

[0045] The antifreeze is 1,2-propanediol.

[0046] The preservative is benzisothiazolinone, brand name Proxel GXL, purchased from Osada Chemical Company.

[0047] The thickener is xanthan gum, brand name Kelzan AP, purchased from CP Kelco, USA.

[0048] The defoamer is polydimethylsiloxane, model SAG-1511, purchased from Momentive Advanced Materials Co., Ltd.

[0049] The second aspect of this example provides a method for preparing a pesticide suspension containing thiophanate-methyl and azoxystrobin, comprising the following steps: In a homogenizing reactor, wetting and dispersing agent, dispersant, wetting emulsifier, suspending thixotropic agent, antifreeze, preservative, defoamer and water are added in sequence. Then, oxadiazon and thiophanate-methyl are added and stirred into a uniform slurry. The slurry is then ground in a sand mill and a thickener is added and stirred evenly to obtain a pesticide suspension containing thiophanate-methyl and oxadiazon.

[0050] The following is a schematic diagram of the appearance of the pesticide suspension after 14 days of heat storage at 54℃. Figure 1 As shown.

[0051] Comparative Example 1 The specific implementation method in this example is the same as in Example 1, except that the raw materials for preparation, by mass parts, include: 5.1 parts 98wt% azoxystrobin, 41 parts 98wt% thiophanate-methyl, 3 parts wetting and dispersing agent, 3 parts dispersant, 5 parts antifreeze, 0.2 parts preservative, 0.2 parts thickener, 0.2 parts defoamer, 42.3 parts water.

[0052] Comparative Example 2 The specific implementation method in this example is the same as in Example 1, except that the raw materials for preparation, by mass parts, include: 5.1 parts 98wt% azoxystrobin, 41 parts 98wt% thiophanate-methyl, 3 parts wetting and dispersing agent, 5 parts dispersant, 5 parts antifreeze, 0.2 parts preservative, 0.2 parts thickener, 0.2 parts defoamer, 40.3 parts water.

[0053] Comparative Example 3 The specific implementation method in this example is the same as in Example 1, except that the raw materials for preparation, by mass parts, include: 5.1 parts 98wt% azoxystrobin, 41 parts 98wt% thiophanate-methyl, 5 parts wetting and dispersing agent, 3 parts dispersant, 5 parts antifreeze, 0.2 parts preservative, 0.2 parts thickener, 0.2 parts defoamer, 40.3 parts water.

[0054] Comparative Example 4 The specific implementation method in this example is the same as in Example 1, except that the raw materials for preparation, by mass parts, include: 5.1 parts 98wt% azoxystrobin, 41 parts 98wt% thiophanate-methyl, 5 parts wetting and dispersing agent, 5 parts dispersant, 5 parts antifreeze, 0.2 parts preservative, 0.2 parts thickener, 0.2 parts defoamer, 38.3 parts water.

[0055] Comparative Example 5 The specific implementation method in this example is the same as in Example 1, except that the raw materials for preparation, by mass parts, include: 5.1 parts 98wt% azoxystrobin, 41 parts 98wt% thiophanate-methyl, 3 parts wetting and dispersing agent, 6 parts dispersant, 5 parts antifreeze agent, 0.2 parts preservative, 0.2 parts thickener, 0.2 parts defoamer, 39.3 parts water.

[0056] The dispersant is Ultrasurf 7023A dispersant and ANTDIS 1608 powder dispersant, with a mass ratio of Ultrasurf 7023A dispersant to ANTDIS 1608 powder dispersant of 1:1; ANTDIS 1608 powder dispersant was purchased from Suzhou Sihangda Energy New Materials Co., Ltd.

[0057] Comparative Example 6 The specific implementation method in this example is the same as in Example 1, except that the raw materials for preparation, by mass parts, include: 5.1 parts 98wt% azoxystrobin, 41 parts 98wt% thiophanate-methyl, 3 parts wetting and dispersing agent, 5 parts dispersant, 5 parts antifreeze, 0.2 parts preservative, 0.2 parts thickener, 0.2 parts defoamer, 40.3 parts water.

[0058] The dispersants are Ultrasurf 7023A and SP-SC3275, with a mass ratio of 3:2. SP-SC3275 was purchased from Jiangsu Qingyu Chemical Technology Co., Ltd.

[0059] The following is a schematic diagram of the appearance of the pesticide suspension after 14 days of heat storage at 54℃. Figure 2 As shown.

[0060] Comparative Example 7 The specific implementation method in this example is the same as in Example 1, except that the raw materials for preparation, by mass parts, include: 5.1 parts 98wt% azoxystrobin, 41 parts 98wt% thiophanate-methyl, 3 parts wetting and dispersing agent, 3 parts dispersant, 3 parts wetting and emulsifying agent, 5 parts antifreeze, 0.2 parts preservative, 0.2 parts thickener, 0.2 parts defoamer, 39.3 parts water.

[0061] Performance testing The stability of pesticide suspensions in Example 1, Comparative Example 1, Comparative Example 5, and Comparative Example 7 was tested. The foaming property test was performed according to GB / T 28137-2011, "Determination of Persistent Foaming Property of Pesticides"; the pH value test was performed according to GB / T 1601-2023; and the stability tests at 25℃, 54℃, and 0℃ were performed according to the general standard GB / T 19136. The 2021 pesticide thermal storage stability test method was used; at the same time, the particle size stability of pesticide suspensions was tested.

[0062] For detailed experimental results, please refer to Table 1-3.

[0063] Table 1

[0064] Table 2

[0065] Table 3

[0066] As can be seen from the experimental results in Tables 1-3, the pesticide suspension concentrate in Example 1 has the best overall performance, with stable particle size, no water precipitation, and high suspension rate; Comparative Examples 1-4 and Comparative Example 6 have moderate performance; Comparative Examples 5 and 7 have poor practicality due to stability issues, and the ratio of adjuvants and the selection of raw materials need to be adjusted.

Claims

1. A pesticide suspension containing thiophanate-methyl and azoxystrobin, characterized in that, The raw materials, by weight, include 5-6 parts of azoxystrobin, 40-42 parts of thiophanate-methyl, 3-5 parts of wetting and dispersing agent, 2-3 parts of dispersant, 1-3 parts of wetting and emulsifying agent, 1-2 parts of suspending thixotropic agent, 3-5 parts of antifreeze, 0.1-0.3 parts of preservative, 0.1-0.3 parts of thickener, 0.1-0.3 parts of defoamer, and 35-45 parts of water; The mass concentration of the oxime ester is 97-99%; The mass concentration of the thiophanate-methyl is 97-99%.

2. The pesticide suspension containing thiophanate-methyl and azoxystrobin according to claim 1, characterized in that, The wetting and dispersing agent is a block polyether mixture.

3. The pesticide suspension containing thiophanate-methyl and azoxystrobin according to claim 2, characterized in that, The block polyether mixture is designated MALIDIS 1895.

4. The pesticide suspension containing thiophanate-methyl and azoxystrobin according to claim 1, characterized in that, The dispersant is a polycarboxylate.

5. The pesticide suspension containing thiophanate-methyl and azoxystrobin according to claim 4, characterized in that, The polycarboxylate is designated as ultrasurf 7023A.

6. The pesticide suspension containing thiophanate-methyl and azoxystrobin according to claim 1, characterized in that, The wetting emulsifier is a block copolymer.

7. The pesticide suspension containing thiophanate-methyl and azoxystrobin according to claim 6, characterized in that, The block copolymer is designated MALIDIS 550L.

8. The pesticide suspension containing thiophanate-methyl and azoxystrobin according to any one of claims 1-7, characterized in that, The suspended thixotropic agent includes one of bentonite, fumed silica, or magnesium aluminum silicate.

9. The pesticide suspension containing thiophanate-methyl and azoxystrobin according to claim 1, characterized in that, The thickeners include one of xanthan gum, guar gum, carbomer, or sodium carboxymethyl cellulose.

10. A method for preparing a pesticide suspension containing thiophanate-methyl and azoxystrobin according to any one of claims 1-9, comprising the following steps: In a homogenizing reactor, wetting and dispersing agent, dispersant, wetting emulsifier, suspending thixotropic agent, antifreeze, preservative, defoamer and water are added in sequence. Then, oxadiazon and thiophanate-methyl are added and stirred into a uniform slurry. The slurry is then ground in a sand mill and a thickener is added and stirred evenly to obtain a pesticide suspension containing thiophanate-methyl and oxadiazon.

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