A heat-resistant prothioconazole and trifloxystrobin aqueous suspension concentrate and its preparation process

Abstract

The present invention relates to the field of insecticide technology, particularly to the field of IPC A01N43. Furthermore, it relates to a heat-resistant prothioconazole and trifloxystrobin aqueous suspension concentrate and a preparation process thereof. The raw materials include at least prothioconazole, trifloxystrobin, a dispersant, and water; the mass ratio of prothioconazole, trifloxystrobin, dispersant, and water is (10-30):(10-30):(4-8):(30-60). The aqueous suspension concentrate prepared by the present invention can maintain particle size stability after storage at 54±2°C for 14 days and at 0±2°C for 7 days, thereby avoiding nozzle clogging during aircraft spraying. Furthermore, the suspension concentrate does not exhibit stratification, bottoming, water precipitation, or flocculation.

Description

Technical Field

[0001] The present invention relates to the technical field of pesticides, in particular to the field of IPC A01N43, and further to a heat-resistant prothioconazole and trifloxystrobin aqueous suspension concentrate and a preparation process thereof. Background Art

[0002] Prothioconazole is a new broad-spectrum fungicide with low toxicity, no teratogenicity, no mutagenicity, no embryotoxicity, and safety for humans, animals, and the environment. It has demonstrated effective control of numerous diseases of wheat, soybeans, rapeseed, rice, peanuts, sugar beets, and vegetables. Combining prothioconazole with other fungicides can enhance synergy.

[0003] For example, Chinese patent CN201310571712 discloses a fungicide composition containing prothioconazole and trifloxystrobin, and its use. The fungicide composition contains prothioconazole and trifloxystrobin as its main active ingredients. This fungicide composition can be used to control diseases of cereals, fruit trees, and vegetables, exhibiting a high synergistic effect, overcoming and delaying drug resistance in pathogens. It exhibits rapid sterilization, a long-lasting effect, and reduced application costs, resulting in significantly better control effectiveness than a single-dose formulation. However, in this technical solution, when the formulation is an aqueous suspension, the prothioconazole content is relatively low.

[0004] As one of the dosage forms of pesticides, aqueous suspension concentrate has the advantages of high efficacy, no use of organic solvents, low volatility and low toxicity. Therefore, aqueous suspension concentrate is an important dosage form that represents the development direction of contemporary pesticide formulation technology.

[0005] However, current aqueous suspension concentrates containing prothioconazole as the main active ingredient have low prothioconazole content. Furthermore, aqueous suspension concentrates prepared with high prothioconazole content have low suspension rates and are prone to instability (bottoming, water precipitation, stratification, and flocculation) after hot storage. Furthermore, the prepared aqueous suspension concentrates have large particle sizes, which can easily clog nozzles during aircraft spraying. Summary of the Invention

[0006] The first aspect of the present invention provides a heat-resistant prothioconazole and trifloxystrobin aqueous suspension concentrate, wherein the raw materials include at least prothioconazole, trifloxystrobin, a dispersant and water; the mass ratio of the prothioconazole, trifloxystrobin, dispersant and water is (10-30): (10-30): (4-8): (30-60).

[0007] In some preferred embodiments, the mass ratio of prothioconazole, trifloxystrobin, dispersant and water is (10-20): (10-20): (4-8): (50-60).

[0008] In some preferred embodiments, the mass content of prothioconazole technical is 94.45%.

[0009] In some preferred embodiments, the mass content of trifloxystrobin technical is 98.4%.

[0010] In some preferred embodiments, the dispersant is selected from one or more combinations of high molecular weight amphiphilic anionic nonionic surfactant complexes, sulfonates, polycarboxylates, and alkylphenol polyoxyethylene phosphates.

[0011] Preferably, the dispersant is a combination of a high molecular weight amphiphilic anionic nonionic surfactant complex and a sulfonate.

[0012] Preferably, the mass ratio of the high molecular weight amphiphilic anionic nonionic surfactant complex to the sulfonate is (2-6):(2-3).

[0013] Preferably, the mass ratio of the high molecular weight amphiphilic anionic nonionic surfactant complex to the sulfonate is (3-5):(2-3).

[0014] Preferably, the rotational viscosity of the high molecular weight amphiphilic anionic nonionic surfactant complex is 10,000 to 20,000 mPa·s (25° C.).

[0015] Preferably, the sulfonate is an alkylnaphthalenesulfonate condensation polymer formed by polyaryl hybridization.

[0016] In some preferred embodiments, the heat-resistant prothioconazole and trifloxystrobin aqueous suspension concentrate raw material further comprises an acidifier.

[0017] Preferably, the acidulant is selected from one or more combinations of anhydrous citric acid, hexahydrate citric acid, and acetic acid.

[0018] Preferably, the acidulant is anhydrous citric acid.

[0019] Preferably, the acidifier accounts for 0.1 to 0.4% of the total mass of the aqueous suspension concentrate.

[0020] Preferably, the acidifier accounts for 0.2 to 0.4% of the total mass of the aqueous suspension concentrate.

[0021] Preferably, the acidifying agent accounts for 0.3% of the total mass of the aqueous suspension concentrate.

[0022] During the experiment, the inventors found that when a combination of a high molecular weight amphiphilic anionic nonionic surfactant complex and a sulfonate is used as a dispersant and the mass ratio of the high molecular weight amphiphilic anionic nonionic surfactant complex to the sulfonate is controlled to be (3-5):(2-3), the prepared aqueous suspension concentrate has a suitable particle size, and the prothioconazole technical and trifloxystrobin technical can be well suspended. However, the suspension rate still does not meet the requirements. Moreover, after the aqueous suspension concentrate is stored at 54±2° C. for 14 days, the particle size of the aqueous suspension concentrate increases sharply, and bottoming and water precipitation occur.

[0023] In order to solve the above technical problems, the inventors unexpectedly discovered during the exploration process that when an acidifier is added to the system of the present invention, especially when the acidifier is anhydrous citric acid, not only can the decomposition of the original drug be effectively reduced so that it meets the decomposition rate requirement when stored at 54±2°C for 14 days, but the particle size increase of the aqueous suspension concentrate after storage at 54±2°C for 14 days can also be suppressed to a certain extent. However, the amount of the acidifier added must be strictly controlled so that the pH of the aqueous suspension concentrate is 4.7-5.5. In particular, when the pH of the aqueous suspension concentrate is 5.1, the prepared aqueous suspension concentrate can maintain particle size stability after storage at 54±2°C for 14 days and at 0±2°C for 7 days, thereby avoiding the problem of nozzle clogging during aircraft spraying; and no stratification, bottoming, water precipitation, or flocculation occurs. The inventors speculate that this is because anhydrous citric acid is used as an acidifying agent to control the pH of the aqueous suspension to 4.7 to 5.5, especially when the pH of the aqueous suspension is 5.1. While effectively reducing the decomposition of the original drug, under this condition, the high molecular weight amphiphilic anionic nonionic surfactant complex and sulfonate can form a protective film on the surface of the original drug particles, and the double electric layer structure formed can exist stably for a long time. When it is in a high temperature state, it can prevent the high molecular weight amphiphilic anionic nonionic surfactant complex and sulfonate from desorbing from the surface of the original drug particles, avoid agglomeration between the original drug particles, and keep their particle size in a stable state.

[0024] In some preferred embodiments, the heat-resistant prothioconazole and trifloxystrobin aqueous suspension concentrate raw materials further include an adjuvant.

[0025] Preferably, the auxiliary agent is selected from one or more combinations of antifreeze agents, preservatives, thickeners, defoaming agents, light stabilizers, and antibacterial agents.

[0026] Preferably, the auxiliary agents include antifreeze, preservatives, thickeners and defoaming agents.

[0027] Preferably, the antifreeze agent is selected from at least one of ethylene glycol, polyethylene glycol, sorbitol, propylene glycol, and glycerol.

[0028] Preferably, the preservative is selected from at least one of isothiazolinone, kasone, sodium nitrite, sodium benzoate, and potassium sorbate.

[0029] Preferably, the thickener is selected from one or more combinations of xanthan gum, magnesium aluminum silicate, attapulgite, hydroxymethyl cellulose, and hydroxyethyl cellulose.

[0030] Preferably, the thickener is a combination of xanthan gum and magnesium aluminum silicate.

[0031] Preferably, the mass ratio of xanthan gum to magnesium aluminum silicate is (1-2): (2-4).

[0032] Preferably, the mass ratio of xanthan gum to magnesium aluminum silicate is 1:2.

[0033] Preferably, the viscosity of the xanthan gum is ≥600 cps (GB1886.41-2015).

[0034] Preferably, the magnesium aluminum silicate is water-soluble organic nano magnesium aluminum silicate.

[0035] Preferably, the dry powder of the water-soluble organic nano-magnesium aluminum silicate has a 325 mesh pass rate of ≥95%.

[0036] Preferably, the defoaming agent is selected from silicone, silicone, C 10-20 Saturated fatty acids, C 8-10 At least one of fatty alcohols.

[0037] Preferably, the defoaming agent is silicone.

[0038] Preferably, the organosilicon is polysiloxane; preferably, the polysiloxane is a polysiloxane compound containing hydrophobic particles.

[0039] In some preferred embodiments, the heat-resistant prothioconazole and trifloxystrobin aqueous suspension concentrate comprises, by mass percentage, 10-20% prothioconazole, 10-20% trifloxystrobin, 4-8% dispersant, 3-7% antifreeze, 0.05-2% preservative, 0.1-0.3% acidulant, 0.2-1% thickener, 0.1-1% defoaming agent, and the balance water.

[0040] The second aspect of the present invention provides a process for preparing a heat-resistant prothioconazole and trifloxystrobin aqueous suspension concentrate, comprising the following steps:

[0041] (1) Weigh each raw material according to mass percentage;

[0042] (2) Mix the raw materials except the thickener and use a shear homogenizer to shear them uniformly. Add the thickener during the shearing process and continue shearing until uniform;

[0043] (3) Sand-grinding the sample uniformly sheared in step (2); sand-grinding until the particle size is less than 5 μm.

[0044] Beneficial effects:

[0045] 1. The present invention adopts a combination of a high molecular weight amphiphilic anionic nonionic surfactant complex and a sulfonate as a dispersant, and when the mass ratio of the high molecular weight amphiphilic anionic nonionic surfactant complex to the sulfonate is controlled to be (3-5): (2-3), the prepared aqueous suspension concentrate has a suitable particle size, which can ensure that the prothioconazole technical and the trifloxystrobin technical have a good suspension state.

[0046] 2. When an acidifier is added to the present invention, especially when anhydrous citric acid is used as the acidifier, not only can the decomposition of the original drug be effectively reduced so that the decomposition rate requirement is met when stored at 54±2°C for 14 days, but the particle size increase of the aqueous suspension concentrate after storage at 54±2°C for 14 days can also be suppressed to a certain extent.

[0047] 3. The present invention controls the amount of acidifier added to adjust the pH of the aqueous suspension concentrate to 4.7 to 5.5. In particular, when the pH of the aqueous suspension concentrate is 5.1, the prepared aqueous suspension concentrate can maintain particle size stability after storage at 54±2°C for 14 days and at 0±2°C for 7 days, thereby avoiding the problem of nozzle clogging during aircraft spraying; and no stratification, bottoming, water precipitation, or flocculation occurs.

[0048] 4. When the mass ratio of prothioconazole, trifloxystrobin, dispersant and water is controlled to (10-20): (10-20): (4-8): (50-60) in the present invention, the stability of the aqueous suspension concentrate after storage at 54±2°C for 14 days can be further improved, and stratification, water separation and flocculation of the aqueous suspension concentrate can be avoided.

[0049] 5. The present invention uses water-soluble organic nano-magnesium aluminum silicate with a viscosity of ≥600 cps xanthan gum and a dry powder 325 mesh pass rate of ≥95% to further reduce the Brownian motion of the original drug particles and avoid the bottoming phenomenon of the aqueous suspension after storage at 54±2°C for 14 days. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 This is the heat storage phenomenon of Example 1.

[0051] Figure 2 This is the heat storage phenomenon of Example 2.

[0052] Figure 3 This is the heat storage phenomenon of Example 3.

[0053] Figure 4 This is the heat storage phenomenon of Example 4.

[0054] Figure 5 This is the heat storage phenomenon of Example 5. DETAILED DESCRIPTION

[0055] Examples 1 to 5 provide a heat-resistant prothioconazole and trifloxystrobin aqueous suspension, the specific formula of which is shown in Table 1; in the table: the rotational viscosity of the polymer amphiphilic anionic nonionic surfactant complex is 16800 mPa·s (25°C), purchased from Jiangsu Qingyu Chemical Technology Co., Ltd., model: SP-SC29; the sulfonate is an alkylnaphthalene sulfonate condensation polymer formed by polyaryl hybridization, purchased from Jiangsu Qingyu Chemical Technology Co., Ltd.; the viscosity of xanthan gum is ≥600 cps (GB1886.41-2015), purchased from Hebei Xinhe Biochemical Co., Ltd.; magnesium aluminum silicate is water-soluble organic nano magnesium aluminum silicate; the dry powder of water-soluble organic nano magnesium aluminum silicate has a 325 mesh pass rate of ≥95%, purchased from Hangzhou Baikeli New Materials Co., Ltd.; polysiloxane is a polysiloxane compound containing hydrophobic particles; purchased from Jiande City Polymer New Materials Co., Ltd., model: JH6800N

[0056] A preparation process of a heat-resistant prothioconazole and trifloxystrobin aqueous suspension concentrate comprises the following steps: (1) weighing raw materials according to mass percentage; (2) uniformly mixing the raw materials except a thickener, shearing the raw materials using a shear homogenizer, adding the thickener during the shearing process, and continuing to shear until uniform; (3) sand-grinding the sample uniformly sheared in step (2); and obtaining the suspension concentrate by sand-grinding until the particle size is less than 5 μm.

[0057] Table 1

[0058]

[0059]

[0060] Performance testing:

[0061] 1. The pH of the aqueous suspension concentrate was tested using a pH meter, and the particle size at 30±2°C (room temperature), the particle size after storage at 54±2°C for 14 days (hot storage), and the particle size after storage at 0±2°C for 7 days (cold storage) were tested using a laser particle size analyzer. The results are shown in Table 2.

[0062] 2. Test the suspension rate of the aqueous suspension concentrate, the decomposition rate of the original drug after the aqueous suspension concentrate is stored at 54±2℃ for 14 days, and the suspension rate after the aqueous suspension concentrate is stored at 0±2℃ for 7 days; observe the hot storage phenomenon, see Figures 1 to 5 ; Test whether nozzle clogging occurs during aircraft spraying; the hot storage stability acceptance standard is: the mass fraction of prothioconazole technical and trifloxystrobin technical is not less than 95% of the mass fraction before storage; the suspension rate and low-temperature stability acceptance standards are: the suspension rate of prothioconazole technical and trifloxystrobin technical are both ≥90%; the results are shown in Table 3.

[0063] 3. Indoor toxicity and combined toxicity determinations: Refer to the "Guidelines for Indoor Bioassay Tests of Pesticides—Fungicides" (NY / T1156.2-2006, NY / T1156.6-2006); the results are shown in Tables 4 and 5.

[0064] Test results:

[0065] Table 2

[0066]

[0067] Table 3

[0068]

[0069]

[0070] Table 4 Indoor toxicity and combined toxicity test of different ratios of prothioconazole and trifloxystrobin against wheat fusarium head blight

[0071]

[0072] As shown in Table 4, the test agents prothioconazole and trifloxystrobin have high activity against wheat fusarium, among which trifloxystrobin has higher toxicity. 50 The value is 0.5382 mg / L, and prothioconazole also has a high toxicity, EC 50 The value is 1.0019 mg / L; the toxicity of the two agents mixed in different proportions to wheat fusarium sphaeroides (EC 50 ) were 0.7259, 0.6210, 0.5782, 0.5421, and 0.5202 mg / L, respectively, and their CTC values were 114.50, 125.62, 120.91, 118.11, and 117.34, respectively. This indicates that the CTCs of the two agents were all greater than 120 within the experimental design ratio range of 2:1 to 1:1, indicating varying degrees of synergistic effect. The 2:1 ratio had the highest CTC and the most significant synergistic effect.

[0073] Table 5 Indoor toxicity and combined toxicity test of different ratios of prothioconazole and trifloxystrobin against rice sheath blight pathogen

[0074]

[0075]

[0076] As can be seen from Table 5, the test agents prothioconazole and trifloxystrobin have high activity against rice sheath blight pathogen. The EC50 value of prothioconazole is 0.7533 mg / L, and the EC90 value is 13.2886 mg / L. The EC50 value of trifloxystrobin is 0.2520 mg / L, and the EC90 value is 4.2974 mg / L. The toxicity (EC50) of the two agents mixed in different proportions against rice sheath blight pathogen are 0.5028, 0.3532, 0.2919, 0.2805 and 0.2712 mg / L, respectively, and the co-toxicity coefficient CTC values are 100.06, 128.23, 129.37, 115.43 and 111.45, respectively. This shows that the co-toxicity coefficients of the two agents are greater than 120 within the experimental design ratio range of 2:1 to 1:1, and there are different degrees of synergistic effects. Among them, the co-toxicity coefficient of the 1:1 ratio is the largest, and there is a synergistic effect.

Claims

1. A heat-resistant prothioconazole and trifloxystrobin aqueous suspension concentrate, characterized in that: By weight percentage, the ingredients include 15% prothioconazole, 15% trifloxystrobin, 4% high molecular weight amphiphilic anionic nonionic surfactant complex, 2.5% sulfonate, 5% ethylene glycol, 0.1% isothiazolinone, 0.3% anhydrous citric acid, 0.25% xanthan gum, 0.5% polysiloxane defoamer, 0.5% magnesium aluminum silicate, and the balance is made up of water to 100%; The rotational viscosity of the high molecular weight amphiphilic anionic nonionic surfactant complex at 25°C was 16800 mPa·s and was purchased from Jiangsu Qingyu Chemical Technology Co., Ltd., model: SP-SC29; The sulfonate is an alkylnaphthalene sulfonate condensation polymer formed by polyaryl hybridization, purchased from Jiangsu Qingyu Chemical Technology Co., Ltd. The viscosity of xanthan gum was ≥600 cps according to GB1886.41-2015 and was purchased from Hebei Xinhe Biochemical Co., Ltd. Magnesium aluminum silicate is a water-soluble organic nano-magnesium aluminum silicate; the dry powder of water-soluble organic nano-magnesium aluminum silicate has a 325 mesh pass rate of ≥95% and is purchased from Hangzhou Baikeli New Materials Co., Ltd. Polysiloxane is a polysiloxane compound containing hydrophobic particles; purchased from Jiande Polymer New Materials Co., Ltd., model: JH6800N; The pH of the aqueous suspension concentrate is 5.1, and the particle size of the aqueous suspension concentrate at room temperature is 2.628 μm.

2. A process for preparing the heat-resistant prothioconazole and trifloxystrobin aqueous suspension concentrate according to claim 1, characterized in that: The method comprises the following steps: weighing various raw materials according to mass percentage; shearing the raw materials uniformly with a shear homogenizer and then sand-grinding the raw materials; and sand-grinding the raw materials until the particle size is less than 5µm.

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