A suspension containing flonicamid and indoxacarb and a method for preparing the same

Abstract

The application provides a suspension agent containing flonicamid and indoxacarb and a preparation method thereof. The suspension agent uses a compound thickening agent, cooperates with a specific antifreezing agent, determines a proper raw material adding sequence and a preparation step, and determines process parameters such as shearing time and grinding temperature, so as to avoid situations such as clumping or caking and decomposition of active ingredients which are prone to occur in the preparation process of the suspension agent, and is suitable for large-scale industrial production. The suspension agent has good stability and remarkable drug efficacy. Field tests show that the suspension agent has a control effect of more than 95% on the rice brown planthopper and the tea green leafhopper, has a long effective period, is safe to crops, and is environment-friendly.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of pesticide preparation, and particularly relates to a suspension concentrate containing flonicamid and indoxacarb as well as a preparation method and application thereof. BACKGROUND

[0002] Pesticide water suspension concentrate (SC) is a stable suspension system in which solid pesticide active ingredients are uniformly dispersed in an aqueous phase, and has the advantages of environmental protection, long-lasting efficacy, and convenient use. Various types of adjuvants are used in the suspension concentrate, and the main adjuvants include dispersants, wetting agents, thickeners, antifreezing agents, and preservatives. In the preparation process, stirring and grinding processes are required, and the process parameters are relatively difficult to control. If the adjuvants are not properly selected or the process parameters are not reasonable, the active ingredients may be decomposed, and the flowability, stability, and efficacy of the preparation may be affected.

[0003] Flonicamid, chemical name N-cyanomethyl-4-(trifluoromethyl) nicotinamide, molecular formula C9H6F3N3O, molecular weight 229.16, white to light yellow crystalline solid, melting point 157-158℃. Solubility in water (20℃) is 3.4 g / L, easily soluble in acetone, methanol, dichloromethane. Stable in acidic medium, slowly hydrolyzed under alkaline conditions. Fonicamid is a pyridine amide insecticide, which can cause starvation death by inhibiting the sucking behavior of pests, and is highly effective against piercing-sucking pests such as aphids and planthoppers. It is widely used for pest control in greenhouses and fields worldwide, and can be used for tomatoes, cucumbers, peppers, apples, grapes, citrus, cotton, potatoes and other vegetables, fruits and other field crops. The conventional dosage form of flonicamid is wettable powder, water dispersible granule and suspension concentrate.

[0004] Indoxacarb, chemical name 7-chloro-2,3,4a,5-tetrahydro-2-[methoxycarbonyl(4-trifluoromethoxyphenyl) aminocarbonyl] indeno [1,2-e] [1,3,4] oxadiazine-4a-carboxylic acid methyl ester, molecular formula 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 at pH 5-9, decomposed by strong acid or strong base. Indoxacarb is a sodium channel inhibitor, preventing Lepidoptera pests including cotton bollworm, diamondback moth, beet armyworm, etc. by contact and stomach action. Indoxacarb is used in global scope for resistant Lepidoptera pest management, which can be used in cabbage, cauliflower, tomato, apple, pear, grape, cotton, corn, soybean, etc. in a variety of vegetables, fruits and field crops. Common dosage forms include emulsifiable concentrate, suspension concentrate and water dispersible granule.

[0005] Chinese patent application CN103053578A discloses a compound insecticidal composition of flonicamid and indoxacarb, wherein it is mentioned that the composition can be prepared into a 42% suspension concentrate and relevant examples are given, but the active ingredient content is too high, and the detailed steps of preparation method and key process parameters are not provided, and quality index detection is not carried out, so the formula should be simulated and not really prepared successfully. SUMMARY

[0006] In one aspect, the present application provides a suspension concentrate of flonicamid and indoxacarb, comprising flonicamid 10-15%, indoxacarb 4-6%, dispersant 5-10%, wetting agent 1-3%, thickening agent 0.8-1.5%, antifreeze 2-5%, defoaming agent 0.1-0.5%, preservative 0.1-0.5%, and deionized water to 100% by mass percentage.

[0007] The thickening agent is a compound of xanthan gum and magnesium aluminum silicate, and the antifreeze is ethylene glycol, wherein the mass ratio of xanthan gum to magnesium aluminum 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 polycarboxylate, phosphate ester, polyether sulfate, lignin sulfonate, alkyl naphthalene formaldehyde condensate sulfonate, sodium lauryl polyoxyethylene ether sulfate, cresol-formaldehyde sodium salt concentrate, sodium dodecyl sulfate, ethoxyphenol ether sulfonate, modified polyacrylate copolymer, dodecyl polyoxyethylene ether phosphate, and polyether sulfate polybasic complex. More preferably, the dispersant is a compound of cresol-formaldehyde sodium salt concentrate and lignin sulfonate in a mass ratio of 3:1.

[0009] Preferably, the wetting agent can be selected from one or more of EO-PO block copolymer, diisopropyl naphthalene sulfonate, fatty alcohol polyoxyethylene ether, nonyl phenol polyoxyethylene ether, alkyl polyoxyethylene ether, phenethyl phenylpropyl phenol polyoxyethylene ether, talcum powder, sodium dodecyl benzene sulfonate, and the like. More preferably, the wetting agent is an EO-PO block copolymer.

[0010] Preferably, the antifoaming agent can be selected from one or more of organosilicon, modified polyether, acetylenic diol, tributyl phosphate, butanol, C8-C10 fatty alcohol, ester-ether type compound, and the like.

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

[0012] In another aspect, the present application provides a preparation method of a flonicamid and indoxacarb compound suspension concentrate, the steps of which are as follows:

[0013] (1) under shearing conditions, a wetting agent, a dispersing agent, and an antifoaming agent are added to deionized water, shearing is continued, and flonicamid and indoxacarb are added, and shearing is continued;

[0014] (2) xanthan gum is first added to an antifreeze agent, ethylene glycol, and stirred and dispersed to form a dispersion liquid, and then the dispersion liquid is added to the mixture obtained in step (1) together with a preservative and another thickening agent, magnesium aluminum silicate, and shearing is continued to obtain a suspension slurry;

[0015] (3) under cooling conditions, the suspension slurry obtained in step (2) is stirred uniformly, and temperature is controlled for three-stage sand milling to obtain a finished product;

[0016] (4) the finished product obtained in step (3) is sent for inspection, and if qualified, it is packed; if not qualified, it is further adjusted, and sent for inspection again until qualified for packing.

[0017] The qualification refers to that the suspension concentrate product meets the relevant quality control indicators in the HG / T 2467.5-2003 Pesticide Suspension Concentrate Product Standard Writing Specification (for example, the quality control indicator detection data in the specific embodiment part of the present application).

[0018] Both xanthan gum and magnesium aluminum silicate are commonly used thickening agents, and their physicochemical properties are different. Xanthan gum can increase the viscosity of the suspension concentrate and inhibit particle sedimentation, but it may cause slight stratification due to gravity during long-term storage. Magnesium aluminum silicate swells to form a colloidal dispersion liquid when it comes into contact with water, and forms a weak gel structure when it is left standing, which can prevent particle sedimentation, and the structure is destroyed and becomes thin under shearing force, and quickly recovers after the external force is removed. After the two are compounded in a certain proportion, the xanthan gum provides basic viscosity, and the magnesium aluminum silicate enhances thixotropy, which can balance the stability and processing performance of the preparation.

[0019] On the other hand, the inventors have found in practice that if all components are added at the same time or the components are added in sequence without any order and stirred, the components tend to clump or agglomerate in the container, and it is difficult to shear to form a uniform suspension slurry. When transferred to the sand mill, a large amount of viscous material is left on the bottom and walls of the container, which is difficult to handle.

[0020] 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 to form a colloidal dispersion when it comes into contact with water. The simultaneous contact of the two with water and organic solvents is the main reason for the clumping or agglomeration of the components. Therefore, the inventors have found that by optimizing the addition sequence and method of various components in the composition, adding xanthan gum dispersed in the 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 problems.

[0021] On the other hand, the inventors have found in practice that flonicamid and indoxacarb are prone to decomposition during processing, especially indoxacarb, which has a low melting point and poor thermal stability, resulting in a decrease in the content of active ingredients in the finished product. Without being bound by any theory, the inventors believe that this is caused by the excessively high temperature during the sand milling process.

[0022] Therefore, more preferably, the grinding process of step (3) needs to start the cooling device, and the temperature of the first-stage sand milling is controlled to be not more than 30℃, and the temperature of the second-stage and third-stage sand milling is controlled to be not more than 35℃.

[0023] By using the above technical solution, the present application has the following beneficial effects:

[0024] (1) Through a large number of tests in the preparation process, appropriate raw material addition sequence and preparation steps, as well as process parameters such as shearing time and grinding temperature are determined, which avoids the clumping or agglomeration, decomposition of active ingredients and other situations that are prone to occur during the preparation process of the suspension agent.

[0025] (2) The suspension agent of the present application has good stability and significant efficacy. Field tests show that the suspension agent has a control effect of more than 95% on the brown planthopper and the tea green leafhopper, has a long duration, is safe to crops, and is environmentally friendly. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed in the following specific embodiment or prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative labor.

[0027] Figure 1 The production process flow chart of the suspension slurry of the formulation example 1;

[0028] Figure 2 A flow chart of the grinding production process for Formulation Example 1 is shown. DETAILED DESCRIPTION

[0029] The application will be further explained in connection with specific embodiments.

[0030] I. Formulation Examples

[0031] Example 1: 18% flonicarimide·indoxacarb suspension concentrate

[0032] Formulation components:

[0033]

[0034] The preparation method is as follows:

[0035] (1) Under shearing conditions, the EO-PO block copolymer wetting agent, the cresol-formaldehyde sodium salt concentrate dispersant, the lignosulfonate dispersant, and the silicone antifoaming agent were added to deionized water, and shearing was continued for 5 min, then flonicarimide and indoxacarb were added, and shearing was continued for 5 min to obtain a mixture;

[0036] (2) The thickening agent xanthan gum was added to the antifreeze ethylene glycol and stirred and dispersed to form a dispersion, which was then added to the mixture obtained in step (1) together with the preservative BIT and the thickening agent magnesium aluminum silicate, and shearing was continued for 15 min to obtain a suspension slurry;

[0037] (3) The cooling device was turned on, the suspension slurry obtained in step (2) was stirred uniformly, and the temperature was controlled for three-stage sand milling to obtain the finished product, wherein the first-stage sand milling temperature was not more than 30℃, and the second- and third-stage sand milling temperatures were not more than 35℃;

[0038] (4) The finished product obtained in step (3) was sent for inspection, and if it was qualified, it was packaged; if it was not qualified, it was further adjusted, and then sent for inspection again until it was qualified for packaging.

[0039] For details, see the preparation process flow chart of Figure 1 and 2 .

[0040] Example 2: 16% flonicarimide·indoxacarb suspension concentrate

[0041] Formulation components:

[0042]

[0043] The preparation method is as follows:

[0044] (1) Under the shearing condition, nonylphenol polyoxyethylene ether wetting agent, lignin sulfonate dispersant, silicone antifoaming agent were added into deionized water, and shearing was continued for 5 min, then flonicamid and indoxacarb were added, and shearing was continued for 5 min to obtain a mixture;

[0045] (2) Thickening agent xanthan gum was added into antifreeze ethylene glycol to be stirred and dispersed to form a dispersion liquid, then the dispersion liquid was added into the mixture obtained in step (1) together with preservative BIT and thickening agent magnesium aluminum silicate, and shearing was continued for 15 min to obtain a suspension slurry;

[0046] (3) The cooling device was started, the suspension slurry obtained in step (2) was stirred uniformly, and three-stage sand milling was carried out at a controlled temperature to obtain a finished product, wherein the first-stage sand milling temperature was not more than 30℃, and the second-stage and third-stage sand milling temperatures were not more than 35℃;

[0047] (4) The finished product obtained in step (3) was sent for inspection, and was packed after being qualified; if unqualified, further adjustment was made, and the product was sent for inspection again until it was qualified for packing.

[0048] Example 3: 19% flonicamid·indoxacarb suspension concentrate

[0049] Formulation components:

[0050]

[0051] The preparation method was as follows:

[0052] (1) Under the shearing condition, fatty alcohol polyoxyethylene ether wetting agent, sodium methyl naphthalene sulfonate formaldehyde condensate dispersant, silicone antifoaming agent were added into deionized water, and shearing was continued for 5 min, then flonicamid and indoxacarb were added, and shearing was continued for 5 min to obtain a mixture;

[0053] (2) Thickening agent xanthan gum was added into antifreeze ethylene glycol to be stirred and dispersed to form a dispersion liquid, then the dispersion liquid was added into the mixture obtained in step (1) together with preservative BIT and thickening agent magnesium aluminum silicate, and shearing was continued for 15 min to obtain a suspension slurry;

[0054] (3) The cooling device was started, the suspension slurry obtained in step (2) was stirred uniformly, and three-stage sand milling was carried out at a controlled temperature to obtain a finished product, wherein the first-stage sand milling temperature was not more than 30℃, and the second-stage and third-stage sand milling temperatures were not more than 35℃;

[0055] (4) The finished product obtained in step (3) was sent for inspection, and was packed after being qualified; if unqualified, further adjustment was made, and the product was sent for inspection again until it was qualified for packing.

[0056] Comparative Example 1:

[0057] The product of Comparative Example 1 was prepared according to the formulation of Example 1, but the preparation method was different, i.e. all the components were sequentially added into a stirring container without any sequence under shearing condition, and stirring and shearing were performed. After the stirring and shearing were completed, the suspension slurry was transferred into a sand mill, and steps (3) and (4) of the preparation method were continued. As mentioned above, there were more blocky materials remaining at the bottom of the stirring container.

[0058] Comparative Example 2:

[0059] The product of Comparative Example 2 was prepared according to the formulation of Example 1, but the preparation method was different, i.e. cooling was not performed in step (3).

[0060] II. Quality control index detection

[0061] A plurality of batches of the sample of Example and Comparative Example were prepared, and the content of active ingredient, suspension rate, pH value and other common indexes of pesticide suspension concentrate were detected.

[0062] The index data of the samples of Example 1-3 are shown in the following table:

[0063]

[0064] Since the content of active ingredient of the samples of Comparative Examples 1-2 was not qualified, other indexes were not detected. The content of active ingredient of the samples is shown in the following table:

[0065]

[0066] From the above data, it can be seen that the samples of the examples of the present application all meet the general requirements of pesticide suspension concentrate. Example 1 is the best example of the present application, and the selection and ratio of active ingredient, dispersant and thickening agent in the formulation are reasonable, so that the suspension rate of active ingredient is more than 95%; Examples 2 and 3 use other dispersants, and the cooperation degree with active ingredient and thickening agent is not as good as that of Example 1, so that the suspension rate of active ingredient is slightly lower, but also more than 90%, which meets the general requirements of pesticide suspension concentrate.

[0067] In addition, the content of active ingredient of the samples of Comparative Examples is obviously decreased. Combined with the observation and detection during preparation, after the suspension slurry of the sample of Comparative Example 1 was transferred into a sand mill, there were more blocky viscous materials remaining at the bottom and wall of the container, which were difficult to clean, which was the main reason for the decrease of the content of active ingredient. Although the residual materials can be additionally cleaned, it will seriously reduce the production efficiency in production, and there is a safety hazard, so this process cannot be used in large-scale industrial production.

[0068] The sample of the comparative example 2 was not cooled during grinding, and the maximum grinding temperature was about 90℃, and the local instantaneous temperature was higher, which caused the content of the two active ingredients to decrease, especially the residual content of indoxacarb was less than 30%; the melting point of indoxacarb was low, and the heat generated during grinding caused part of the technical material to melt, the viscosity of the slurry increased sharply, and a paste-like substance was formed, which seriously affected the fluidity, increased the grinding resistance, reduced the efficiency of the sand mill, and prolonged the production time.

[0069] III. Field test

[0070] Test design (according to GB / T 17980.52-2000)

[0071] Test site: Nanjing City, Jiangsu Province (rice field), Hangzhou City, Zhejiang Province (tea garden)

[0072] Plot area: 30 m² (5m x 6m), with a spacing of 0.5m;

[0073] Pesticide used: Example 1-3 suspending agent, 10% flonicamid suspending agent, 5% indoxacarb suspending agent

[0074] Application method: dilute the pesticide 1000 times, and spray 45 L per mu of liquid; spray twice (with an interval of 7 days) during the tillering period of rice and at the initial stage of tea leafhopper occurrence (early July).

[0075] The data of the test pesticide on the control effect and the persistence period of brown planthopper and tea leafhopper:

[0076]

[0077] The test data show that the control effect of the compound suspending agent of the application is improved by 15%-30% compared with single agent, and the persistence period is prolonged by 12-17 days. After dilution with water in the field, the pouring residue is ≤0.5%, which meets the national standard requirements.

[0078] Finally, it should be pointed out that: the above examples are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A suspension containing flonicamid and indoxacarb, characterized in that, The pesticide composition comprises, by mass percentage, flonicamid 10-15%, indoxacarb 4-6%, dispersing agent 3-10%, wetting agent 1-3%, thickening agent 0.8-1.5%, antifreezing agent 2-5%, antifoaming agent 0.1-0.5%, preservative 0.1-0.5%, and deionized water to 100%. The thickening agent is compounded from xanthan gum and magnesium aluminum silicate, and the antifreezing agent is ethylene glycol. The mass ratio of the xanthan gum to the magnesium aluminum silicate is 0.15-0.2:0.8-1.2, and the mass ratio of the xanthan gum to the ethylene glycol is 0.15-0.2:

4. The dispersing agent is compounded from methylphenyl carbinol-formaldehyde sodium salt concentrate and lignosulfonate at a mass ratio of 3:

1. The wetting agent is an EO-PO block copolymer.

2. The suspension of claim 1, wherein, The antifoaming agent is selected from one or more of organosilicon, modified polyether, acetylenic diol, tributyl phosphate, butanol, C8-C10 fatty alcohol, ester-ether type compound.

3. The suspension of claim 1, wherein, The preservative is selected from one or more of benzisothiazolinone, sodium benzoate, formaldehyde, polyformaldehyde, sodium citrate, sodium salicylate, potassium sorbate, and carboxin.

4. A process for the preparation of a suspension concentrate of flonicamid and indoxacarb according to any one of claims 1 to 3, characterized in that, The steps are as follows: (1) under shearing conditions, the wetting agent, dispersing agent, and antifoaming agent are added to deionized water, shearing is continued, and flonicamid and indoxacarb are added, and shearing is continued; (2) the xanthan gum is first added to the antifreezing agent ethylene glycol and stirred and dispersed to form a dispersion, and then the dispersion is added to the mixture obtained in step (1) together with the preservative and another thickening agent, magnesium aluminum silicate, and shearing is continued to obtain a suspension slurry; (3) under cooling conditions, the suspension slurry obtained in step (2) is stirred uniformly, and the temperature is controlled to perform three-stage sand milling to obtain the finished product, wherein the temperature of the first-stage sand milling is not more than 30℃, and the temperatures of the second-stage and third-stage sand milling are not more than 35℃; (4) the finished product obtained in step (3) is sent for inspection, and if qualified, it is packed; if not qualified, it is further adjusted, and then sent for inspection again until qualified and packed.

5. Use of a suspension concentrate containing flonicamid and indoxacarb according to any one of claims 1 to 3 or a suspension concentrate containing flonicamid and indoxacarb prepared according to the production process of claim 4 for controlling agricultural pests, characterized in that, The pests are brown planthopper and tea green leafhopper.

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