Suspending agent containing flonicamid and indoxacarb and preparation method thereof

Abstract

The invention provides a suspending agent containing flonicamid and indoxacarb and a preparation method of the suspending agent. According to the suspending agent, the compound thickening agent is used and matched with the specific anti-freezing agent, the proper raw material adding sequence and preparation steps as well as the shearing time, the grinding temperature and other process parameters are determined, the conditions of huddling or caking, active ingredient decomposition and the like which are prone to occurring in the suspending agent preparation process are avoided, and the suspending agent is suitable for large-scale industrial production. The suspending agent disclosed by the invention is good in stability and remarkable in pesticide effect. Field tests show that the control effect of the suspending agent on rice brown planthopper and tea lesser leafhopper reaches 95% or above, the lasting period is long, and the suspending agent is safe to crops and environmentally friendly.

Description

Technical Field

[0001] The invention belongs to the technical field of pesticide preparations, and particularly relates to a suspension concentrate containing flonicamid and indoxacarb, and a preparation method and application thereof. Background Art

[0002] Pesticide suspension concentrate (SC) is a stable suspension system that evenly disperses the active ingredients of solid pesticides in the aqueous phase. It has the advantages of being environmentally friendly, lasting efficacy, and easy to use. Suspension concentrates use a variety of adjuvants, the main adjuvants include dispersants, wetting agents, thickeners, antifreeze agents, preservatives, etc. The preparation process requires the use of stirring, grinding and other processes, and the process parameters are relatively difficult to control. If the adjuvants are not properly selected or the process parameters are unreasonable, it is easy to cause clumping or agglomeration, decomposition of active ingredients, etc. during the preparation process, affecting the fluidity, stability and efficacy of the preparation.

[0003] Flunicamid, chemical name N-cyanomethyl-4-(trifluoromethyl) nicotinamide, molecular formula C9H6F3N3O, molecular weight 229.16, white to light yellow crystalline solid, melting point 157-158℃. Water (20℃) solubility is 3.4 g / L, easily soluble in acetone, methanol, and dichloromethane. It is stable in acidic medium and slowly hydrolyzes under alkaline conditions. Flunicamid is a pyridine amide insecticide that inhibits the sucking behavior of pests and causes starvation death. It is highly effective against piercing-sucking pests such as aphids and planthoppers. It is widely used in greenhouse and field pest air defense worldwide, and can be used for a variety of vegetables, fruits and other field crops such as tomatoes, cucumbers, peppers, apples, grapes, citrus, cotton, potatoes, etc. The conventional formulations of flunicamid are wettable powders, water-dispersible granules and suspensions.

[0004] Indoxacarb, chemical name is 7-chloro-2,3,4a,5-tetrahydro-2-[methoxycarbonyl(4-trifluoromethoxyphenyl)carbamoyl]indeno[1,2-e][1,3,4]oxadiazine-4a-carboxylic acid methyl ester, molecular formula is C 22 H 17ClF3N3O7, molecular weight 527.83, white crystalline powder, melting point 88.1-88.6℃, water (20℃) solubility 0.2mg / L, easily soluble in acetone, dichloromethane, xylene, stable to light, stable in water with pH 5-9, decomposed in strong acid or alkali. Indoxacarb is a sodium channel inhibitor, which controls lepidopteran pests, including cotton bollworm, diamondback moth, beet armyworm, etc., through contact and stomach poisoning. Indoxacarb is used worldwide to control resistant lepidopteran pests and can be used for a variety of vegetables, fruits and field crops such as cabbage, cauliflower, tomato, apple, pear, grape, cotton, corn, soybean, etc. Common dosage forms include emulsion, suspension and water dispersible granules.

[0005] Chinese patent application CN103053578A discloses a composite insecticide composition of flubendiamide and indoxacarb, which mentions that the composition can be made into a 42% suspension and provides relevant examples. However, the content of active ingredients is too high, and the detailed steps and key process parameters of the preparation method are not provided, and quality index testing is not performed. Therefore, the formula should be simulated and not actually prepared successfully. Summary of the invention

[0006] On the one hand, the present invention provides a suspension concentrate of flunicromid and indoxacarb, which comprises, by weight percentage, 10-15% of flunicromid, 4-6% of indoxacarb, 5-10% of dispersant, 1-3% of wetting agent, 0.8-1.5% of thickener, 2-5% of antifreeze agent, 0.1-0.5% of defoamer, 0.1-0.5% of preservative, and deionized water makes up 100%.

[0007] The thickener is a compound of xanthan gum and aluminum magnesium silicate, and the antifreeze agent is ethylene glycol. The mass ratio of xanthan gum to aluminum magnesium silicate is 0.15-0.2:0.8-1.2, preferably 0.18:1; the mass ratio of xanthan gum to ethylene glycol is 0.15-0.2:4, preferably 0.18:4.

[0008] Preferably, the dispersant can be selected from one or more of polycarboxylates, phosphates, polyether sulfates, lignin sulfonates, alkylnaphthalene formaldehyde condensate sulfonates, sodium lauryl polyoxyethylene ether sulfate, cresol-formaldehyde sodium salt concentrates, sodium dodecyl sulfate, ethoxyphenol ether sulfonates, modified polyacrylate copolymers, dodecyl polyoxyethylene ether phosphates, sulfate polyether multicomponents, etc. More preferably, the dispersant is a compound of cresol-formaldehyde sodium salt concentrates and lignin sulfonates in a mass ratio of 3:1.

[0009] Preferably, the wetting agent can be selected from one or more of EO-PO block copolymer, diisopropylnaphthalene sulfonate, fatty alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether, alkyl polyoxyethylene ether, phenylethyl phenylpropylphenol polyoxyethylene ether, pull-opening powder, sodium dodecylbenzene sulfonate, etc. More preferably, the wetting agent is EO-PO block copolymer.

[0010] Preferably, the defoaming agent can be selected from one or more of silicones, modified polyethers, acetylene glycols, tributyl phosphate, butanol, C8-C10 fatty alcohols, ester-ether compounds and the like.

[0011] Preferably, the preservative can be selected from one or more of benzisothiazolinone, sodium benzoate, formaldehyde, polyoxymethylene, sodium citrate, sodium salicylate, potassium sorbate, and kasone.

[0012] On the other hand, the present invention provides a method for preparing a composite suspension of flonicamid and indoxacarb, the steps of which are as follows: (1) Under shearing conditions, a wetting agent, a dispersant, and a defoaming agent are added to deionized water, and the shearing is continued. Fluniciamide and indoxacarb are added, and the shearing is continued; (2) firstly adding xanthan gum into antifreeze agent ethylene glycol and stirring and dispersing to form a dispersion, then adding the dispersion together with a preservative and another thickener magnesium aluminum silicate to the mixture obtained in step (1), and continuing to shear to obtain a suspension slurry; (3) Under cooling conditions, the suspension slurry obtained in step (2) is stirred evenly, and the temperature is controlled to perform three-stage sand grinding to obtain a finished product; (4) The finished product obtained in step (3) is sent for inspection and packaged after it passes the inspection. If it fails the inspection, it is further adjusted and sent for inspection again until it passes the inspection and packaged.

[0013] The qualified means that the suspension concentrate product meets the relevant quality control indicators in HG / T2467.5-2003 Pesticide Suspension Concentrate Product Standard Preparation Specification (such as the quality control indicator test data in the specific implementation method section of this article).

[0014] Xanthan gum and aluminum magnesium silicate are both commonly used thickeners. They have different physical and chemical properties. Xanthan gum can increase the viscosity of the suspension and inhibit particle sedimentation, but long-term storage may cause slight stratification due to gravity. On the other hand, aluminum magnesium silicate swells in water to form a colloidal dispersion, and forms a weak gel structure when left standing, which can prevent particle sedimentation. The structure is destroyed and thinned under shear force, and recovers quickly after the external force is removed. After the two are compounded in a certain proportion, xanthan gum provides basic viscosity, and aluminum magnesium silicate enhances thixotropy, which can balance the stability of the preparation and processing performance.

[0015] On the other hand, the inventors have found in practice that if all components are added at the same time or added one after another in no particular order and stirred, the components tend to clump or agglomerate in the container, making it difficult to shear to form a uniform suspended slurry. When transferred to the sand mill, a large amount of viscous material will remain at the bottom and wall of the container, which is difficult to handle.

[0016] Without being bound by any theory, the inventors believe that xanthan gum is easily soluble in water to form a high viscosity solution, but is insoluble in organic solvents, while magnesium aluminum silicate swells in water to form a colloidal dispersion, and the simultaneous contact of the two with water and organic solvents is the main reason for the components to clump or agglomerate. Therefore, the inventors optimized the order and method of adding various components in the composition and found that stirring and dispersing xanthan gum in antifreeze ethylene glycol to form a dispersion, and then adding it together with magnesium aluminum silicate to the mixture of other components can solve the above problem.

[0017] On the other hand, the inventors found in practice that flonicamid and indoxacarb are easily decomposed during processing, especially indoxacarb has a low melting point and poor thermal stability, resulting in a reduction in the content of active ingredients in the finished product. Without being bound by any theory, the inventors believe that this is due to excessively high temperatures during sand milling.

[0018] Therefore, more preferably, the cooling device needs to be turned on during the grinding process of step (3) to control the temperature of the first-stage sanding to not exceed 30°C, and the temperature of the second and third-stage sanding to not exceed 35°C.

[0019] By adopting the above technical solution, the present invention has the following beneficial effects: (1) During the preparation process, a large number of experiments were conducted to determine the appropriate sequence of raw material addition and preparation steps, as well as process parameters such as shear time and grinding temperature, to avoid clumping or caking, and decomposition of active ingredients, which are common in the preparation of suspension concentrates.

[0020] (2) The suspension concentrate of the present invention has good stability and significant efficacy. Field tests have shown that the suspension concentrate has a control effect of more than 95% on rice brown planthoppers and tea green leafhoppers, has a long lasting effect, is safe for crops, and is environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 The suspension slurry production process flow chart of Formulation Example 1; Figure 2This is a flow chart of the grinding production process of Formulation Example 1. DETAILED DESCRIPTION

[0023] The present invention is further explained below in conjunction with specific implementation modes.

[0024] 1. Preparation Examples Example 1: 18% Fluphenacamide-Indoxacarb Suspension Concentrate Recipe ingredients:

[0025] The preparation method is as follows: (1) Under shearing conditions, an EO-PO block copolymer wetting agent, a cresol-formaldehyde sodium salt concentrate dispersant, a lignin sulfonate dispersant, and a silicone defoamer are added to deionized water, and the shearing is continued for 5 minutes. Flonacam and indoxacarb are added, and the shearing is continued for 5 minutes to obtain a mixture; (2) adding xanthan gum as a thickener to ethylene glycol as an antifreeze agent and stirring and dispersing the mixture to form a dispersion, then adding the dispersion together with BIT as a preservative and aluminum magnesium silicate as a thickener to the mixture obtained in step (1), and continuing to shear for 15 minutes to obtain a suspension slurry; (3) turning on the cooling device, stirring the suspension slurry obtained in step (2) uniformly, and controlling the temperature to perform three-stage sand grinding to obtain a finished product, wherein the first-stage sand grinding temperature does not exceed 30° C., and the second and third-stage sand grinding temperatures do not exceed 35° C.; (4) The finished product obtained in step (3) is sent for inspection and packaged after it passes the inspection. If it fails the inspection, it is further adjusted and sent for inspection again until it passes the inspection and packaged.

[0026] For details, please refer to the attached Figure 1 and 2 Preparation process flow chart.

[0027] Example 2: 16% Fluphenacamide-Indoxacarb Suspension Concentrate Recipe ingredients:

[0028] The preparation method is as follows: (1) Under shearing conditions, nonylphenol polyoxyethylene ether wetting agent, lignin sulfonate dispersant, and silicone defoaming agent were added to deionized water, and the shearing was continued for 5 minutes. Flonacam and indoxacarb were added, and the shearing was continued for 5 minutes to obtain a mixture; (2) adding xanthan gum as a thickener to ethylene glycol as an antifreeze agent and stirring and dispersing the mixture to form a dispersion, then adding the dispersion together with BIT as a preservative and aluminum magnesium silicate as a thickener to the mixture obtained in step (1), and continuing to shear for 15 minutes to obtain a suspension slurry; (3) turning on the cooling device, stirring the suspension slurry obtained in step (2) uniformly, and controlling the temperature to perform three-stage sand grinding to obtain a finished product, wherein the first-stage sand grinding temperature does not exceed 30° C., and the second and third-stage sand grinding temperatures do not exceed 35° C.; (4) The finished product obtained in step (3) is sent for inspection and packaged after it passes the inspection. If it fails the inspection, it is further adjusted and sent for inspection again until it passes the inspection and packaged.

[0029] Example 3: 19% Fluphenacamide-Indoxacarb Suspension Concentrate Recipe ingredients:

[0030] The preparation method is as follows: (1) under shearing conditions, a fatty alcohol polyoxyethylene ether wetting agent, a sodium methyl naphthalene sulfonate formaldehyde condensate dispersant, and a silicone defoaming agent were added to deionized water, and the shearing was continued for 5 minutes, and flonicamid and indoxacarb were added, and the shearing was continued for 5 minutes to obtain a mixture; (2) adding xanthan gum as a thickener to ethylene glycol as an antifreeze agent and stirring and dispersing the mixture to form a dispersion, then adding the dispersion together with BIT as a preservative and aluminum magnesium silicate as a thickener to the mixture obtained in step (1), and continuing to shear for 15 minutes to obtain a suspension slurry; (3) turning on the cooling device, stirring the suspension slurry obtained in step (2) uniformly, and controlling the temperature to perform three-stage sand grinding to obtain a finished product, wherein the first-stage sand grinding temperature does not exceed 30° C., and the second and third-stage sand grinding temperatures do not exceed 35° C.; (4) The finished product obtained in step (3) is sent for inspection and packaged after it passes the inspection. If it fails the inspection, it is further adjusted and sent for inspection again until it passes the inspection and packaged.

[0031] Comparative Example 1: The product of Comparative Example 1 was prepared according to the formula composition of Example 1, but the preparation method was different, that is, all the components were added to the stirring container in order under shearing conditions, and stirred and sheared. After the stirring and shearing was completed, the suspension slurry was transferred to a sand mill, and steps (3) and (4) of the preparation method were continued. As mentioned above, a large amount of block material remained at the bottom of the stirring container.

[0032] Comparative Example 2: The product of Comparative Example 2 was prepared according to the formulation of Example 1, except that the preparation method was different, i.e., no cooling was performed in step (3).

[0033] 2. Quality control index testing Multiple batches of examples and comparative examples were prepared, and common indicators of pesticide suspensions such as active ingredient content, suspension rate, and pH value were tested.

[0034] The index data of the samples of Examples 1-3 are shown in the following table:

[0035] Since the active ingredient content of the samples of Comparative Example 1-2 was expected to be unqualified, other indicators were not tested. The active ingredient content data are shown in the following table:

[0036] From the above data, it can be seen that the samples of the embodiments of the present invention all meet the general requirements of pesticide suspension concentrates. Embodiment 1 is the best embodiment of the present invention, and the selection and proportion of the active ingredient, dispersant, and thickener in its formula are reasonable, so that the suspension rate of the active ingredient is above 95%; Embodiments 2 and 3 use other dispersants, and the degree of coordination with the active ingredient and thickener is not as good as that of Embodiment 1, and the suspension rate of the active ingredient is slightly lower, but it is also more than 90%, which meets the general requirements of pesticide suspension concentrates.

[0037] In addition, the active ingredient content of the comparative samples was significantly reduced. Combined with the observation and detection during the preparation process, when the sample of comparative example 1 was prepared, after the suspension slurry was transferred to the sand mill, a large amount of blocky viscous materials remained on the bottom and wall of the container, which was difficult to clean. This was the main reason for the decrease in the active ingredient content. Although the residual materials could be cleaned up additionally, the production efficiency would be seriously reduced during production, and there were also safety hazards. Therefore, this process could not be used in large-scale industrial production.

[0038] No cooling equipment was used during grinding of the sample in Comparative Example 2, and the highest grinding temperature reached about 90°C, with the local instantaneous temperature being even higher, which resulted in a decrease in the content of the two active ingredients, especially indoxacarb, with a residual amount of less than 30%. Indoxacarb has a low melting point, and the heat generated during the grinding process caused part of the original drug to melt, causing the viscosity of the slurry to increase sharply, forming a paste-like substance, which seriously affected the fluidity, increased the grinding resistance, reduced the efficiency of the sand mill, and prolonged the production time.

[0039] 3. Field trials Experimental design (according to GB / T 17980.52-2000) Test location: Nanjing, Jiangsu Province (rice fields), Hangzhou, Zhejiang Province (tea gardens) Cell area: 30 m² (5m×6m), 0.5m interval; Drugs used: SC of Examples 1-3, 10% flonicamid SC, 5% indoxacarb SC Application method: dilute the agent 1000 times, spray 45 L per mu, apply the agent twice in a row (with an interval of 7 days) during the rice tillering stage and the early outbreak of tea green leafhoppers (early July).

[0040] The efficacy data and duration of the test agent against brown planthopper and tea green leafhopper:

[0041] The test data show that the compound suspension concentrate of the present invention has a 15%-30% higher control effect than a single agent, and the effective period is extended by 12-17 days. After dilution with water in the field, the dumping residue is ≤0.5%, which meets the national standard requirements.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A suspension concentrate containing flonicamid and indoxacarb, characterized in that: Calculated by mass percentage, it contains 10-15% of flonicamid, 4-6% of indoxacarb, 3-10% of dispersant, 1-3% of wetting agent, 0.8-1.5% of thickener, 2-5% of antifreeze agent, 0.1-0.5% of defoamer, 0.1-0.5% of preservative, and deionized water makes up 100%; The thickener is a compound of xanthan gum and magnesium aluminum silicate, the antifreeze is ethylene glycol, the mass ratio of xanthan gum to magnesium aluminum silicate is 0.15-0.2:0.8-1.2, and the mass ratio of xanthan gum to ethylene glycol is 0.15-0.2:

4.

2. The suspension concentrate containing flonicamid and indoxacarb according to claim 1, characterized in that: The dispersant can be selected from one or more of polycarboxylates, phosphates, polyether sulfates, lignin sulfonates, alkylnaphthalene formaldehyde condensate sulfonates, sodium lauryl polyoxyethylene ether sulfate, cresol-formaldehyde sodium salt concentrates, sodium dodecyl sulfate, ethoxyphenol ether sulfonates, modified polyacrylate copolymers, dodecyl polyoxyethylene ether phosphates, and sulfate polyether multi-complexes.

3. A suspension concentrate containing flonicamid and indoxacarb according to claim 2, characterized in that: The dispersant is prepared by mixing cresol-formaldehyde sodium salt concentrate and lignin sulfonate in a mass ratio of 3:

1.

4. The suspension concentrate containing flonicamid and indoxacarb according to claim 1, characterized in that: The wetting agent can be selected from one or more of EO-PO block copolymer, diisopropylnaphthalene sulfonate, fatty alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether, alkyl polyoxyethylene ether, phenethyl phenylpropylphenol polyoxyethylene ether, pull-opening powder, sodium dodecylbenzene sulfonate.

5. The suspension concentrate containing flonicamid and indoxacarb according to claim 4, characterized in that: The wetting agent is an EO-PO block copolymer.

6. The suspension concentrate containing flonicamid and indoxacarb according to claim 1, characterized in that: The defoaming agent can be selected from one or more of silicones, modified polyethers, acetylene glycols, tributyl phosphate, butanol, C8-C10 fatty alcohols, and ester-ether compounds.

7. The suspension concentrate containing flonicamid and indoxacarb according to claim 1, characterized in that: The preservative can be selected from one or more of benzisothiazolinone, sodium benzoate, formaldehyde, polyoxymethylene, sodium citrate, sodium salicylate, potassium sorbate and kasone.

8. A method for preparing a suspension concentrate containing flonicamid and indoxacarb according to any one of claims 1 to 7, characterized in that: Here are the steps: (1) Under shearing conditions, a wetting agent, a dispersant, and a defoaming agent are added to deionized water, and the shearing is continued. Fluniciamide and indoxacarb are added, and the shearing is continued; (2) firstly adding xanthan gum into antifreeze agent ethylene glycol and stirring and dispersing to form a dispersion, then adding the dispersion together with a preservative and another thickener magnesium aluminum silicate to the mixture obtained in step (1), and continuing to shear to obtain a suspension slurry; (3) Under cooling conditions, the suspension slurry obtained in step (2) is stirred evenly, and the temperature is controlled to perform three-stage sand grinding to obtain a finished product; (4) The finished product obtained in step (3) is sent for inspection and packaged after it passes the inspection. If it fails the inspection, it is further adjusted and sent for inspection again until it passes the inspection and packaged.

9. The method for preparing a suspension concentrate containing flonicamid and indoxacarb according to claim 8, characterized in that: The cooling device must be turned on during the grinding process of step (3) to control the first-stage sanding temperature not to exceed 30°C, and the second and third-stage sanding temperatures not to exceed 35°C.

10. Use of a suspension concentrate containing flonicamid and indoxacarb according to any one of claims 1 to 7 or a suspension concentrate containing flonicamid and indoxacarb prepared according to the preparation method of any one of claims 8 to 9 in controlling agricultural pests, characterized in that: The pests include brown planthopper and tea green leafhopper.

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