Suspending agent containing emamectin benzoate and indoxacarb

Abstract

The invention provides a suspending agent containing emamectin benzoate and indoxacarb. The suspending agent comprises emamectin benzoate and indoxacarb. 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 trials show that the suspending agent has an excellent control effect on lepidoptera pests, is long in lasting period, is safe to crops and is environment-friendly.

Description

Technical Field

[0001] The invention belongs to the technical field of pesticide preparations, and particularly relates to a suspension containing avermectin 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] Emamectin Benzoate is a new type of highly effective semi-synthetic antibiotic insecticide, a white or light yellow crystalline solid, with a melting point of 141-146°C, slightly soluble in dichloromethane, chloroform, methanol, slightly soluble in water, and insoluble in hexane. Emamectin Benzoate has high activity against a variety of pests, including Lepidoptera, Diptera, Coleoptera, and Thrips, and is widely used on vegetables, fruit trees, cotton, and field crops such as rice, corn, and wheat. Emamectin Benzoate is usually used in the form of its benzoate salt, and conventional dosage forms include emulsifiable concentrates, microemulsions, emulsions in water, wettable powders, water-dispersible granules, etc.

[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 17 ClF3N3O7, 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. It can be used for cabbage, cauliflower, tomato, apple, pear, grape, cotton, corn, soybean and other vegetables, fruits and field crops. Common dosage forms include emulsion, suspension and water dispersible granules.

[0005] Chinese patent application CN101263823A discloses a pesticide composition of indoxacarb and emamectin benzoate, in which the formula of the suspension concentrate is given. However, the patent application mainly focuses on the synergistic effect of the combination of indoxacarb and emamectin benzoate, rather than the development of applicable dosage forms, and does not conduct quality control index testing on the various dosage forms prepared. Therefore, the suspension concentrate formula should belong to a small batch trial formula on a laboratory scale. Therefore, the patent application does not focus on the process difficulties of the suspension concentrate in large-scale industrial production. Summary of the invention

[0006] To be suitable for large-scale industrial production, the present invention provides a suspension prepared by mixing avermectin and indoxacarb, which comprises, by weight percentage, 1.0-3.5% of avermectin, 5-12% of indoxacarb, 2-4% of a dispersant, 2-4% of a wetting agent, 1.5-3% of a thickener, 0.1-0.5% of a preservative, 2-5% of an antifreeze agent, 0.3-0.8% of a pH regulator, 0.1-0.5% of a defoaming agent, and the content of the suspension is supplemented to 100% by deionized water.

[0007] Among them, the thickener is a compound of xanthan gum, magnesium aluminum silicate and white carbon black, the antifreeze agent is ethylene glycol, the mass ratio of xanthan gum, magnesium aluminum silicate and white carbon black is 0.15-0.2:0.8-1.2:0.8-1.2, preferably 0.2:1.2:1.0; the mass ratio of xanthan gum to ethylene glycol is 0.15-0.2:4, preferably 0.2:4.

[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 multi-complexes, and the like.

[0009] Preferably, the wetting agent can be selected from one or more of EO-PO block copolymers, diisopropylnaphthalene sulfonates, fatty alcohol polyoxyethylene ethers, nonylphenol polyoxyethylene ethers, alkyl polyoxyethylene ethers, phenethyl phenylpropylphenol polyoxyethylene ethers, pull-opening powder, sodium dodecylbenzene sulfonate, and the like.

[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] Preferably, the pH adjuster can be selected from one or more of glacial acetic acid, citric acid, boric acid, dilute hydrochloric acid and the like.

[0013] On the other hand, the present invention provides a method for preparing a composite suspension of avermectin 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. Emamectin and indoxacarb are added, and the shearing is continued; (2) firstly add xanthan gum to antifreeze agent ethylene glycol and stir and disperse to form a dispersion, then add the xanthan gum together with a preservative and two other thickeners, magnesium aluminum silicate and white carbon black, to the mixture obtained in step (1), continue shearing, add a pH adjuster, and stir 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.

[0014] 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).

[0015] Xanthan gum, aluminum magnesium silicate and white carbon black are all commonly used thickeners, and the three 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; aluminum magnesium silicate swells in water to form a colloidal dispersion, and forms a weak gel structure when standing, which can prevent particle sedimentation. The structure is destroyed and thinned under shear force, and it recovers quickly after the external force is removed; white carbon black is insensitive to changes in temperature and pH value, is not easily affected by electrolytes and other additives, has no charge, and has good compatibility with various types of surfactants. After the three are compounded in a certain proportion, xanthan gum provides basic viscosity, aluminum magnesium silicate enhances thixotropy, and white carbon black is relatively stable and has good compatibility with other additives, which can balance the stability of the preparation and processing performance.

[0016] 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.

[0017] 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 to the mixture of other components together with white carbon black and magnesium aluminum silicate can solve the above problem.

[0018] On the other hand, the inventors found in practice that avermectin and indoxacarb have low melting points and poor thermal stability, and are easily decomposed during product processing, 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 the sand milling process.

[0019] 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.

[0020] 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. This avoided the clumping or caking and decomposition of active ingredients that are prone to occur during the preparation of the suspension, making it suitable for large-scale industrial production.

[0021] (2) The suspension concentrate of the present invention has good stability and significant efficacy. Field tests have shown that the suspension concentrate has excellent control effect on lepidopteran pests, has a long lasting effect, is safe for crops, and is environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] 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.

[0023] Figure 1 This is the suspension slurry production process of Formulation Example 1; Figure 2 This is the sand milling production process of Formulation Example 1. DETAILED DESCRIPTION

[0024] The present invention is further explained below in conjunction with specific implementation modes.

[0025] 1. Preparation Examples Example 1: 8.8% Emamectin·Indoxacarb Suspension Recipe ingredients:

[0026] The preparation method is as follows: (1) Under shearing conditions, EO-PO block copolymer wetting agent, polycarboxylate dispersant, and silicone defoamer are added to deionized water, and the shearing is continued for 5 minutes. Emamectin benzoate and indoxacarb are added, and the shearing is continued for 5 minutes to obtain a mixture; (2) adding the thickener xanthan gum to the antifreeze agent ethylene glycol and stirring and dispersing the mixture to form a dispersion, and then adding the dispersion together with the preservative BIT and two other thickeners white carbon black and magnesium aluminum silicate to the mixture obtained in step (1), and continuing to shear for 15 minutes, during which time citric acid is added and stirred 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.

[0027] For details, please refer to the attached Figure 1 and 2 Production process flow chart.

[0028] Example 2: 15.5% Emamectin·Indoxacarb Suspension Recipe ingredients:

[0029] 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, and avermectin benzoate and indoxacarb were added, and the shearing was continued for 5 minutes to obtain a mixture; (2) adding the thickener xanthan gum to the antifreeze agent ethylene glycol and stirring to disperse, then adding the preservative BIT and the thickeners magnesium aluminum silicate and white carbon black to form a dispersion, adding the dispersion to the mixture obtained in step (1), and continuing to shear for 15 minutes, during which time citric acid is added and stirred 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.

[0030] Example 3: 6.8% Emamectin·Indoxacarb Suspension Recipe ingredients:

[0031] 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 avermectin benzoate and indoxacarb were added, and the shearing was continued for 5 minutes to obtain a mixture; (2) adding the thickener xanthan gum to the antifreeze agent ethylene glycol and stirring to disperse, then adding the preservative BIT and the thickeners magnesium aluminum silicate and white carbon black to form a dispersion, adding the dispersion to the mixture obtained in step (1), and continuing to shear for 15 minutes, during which time citric acid is added and stirred 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.

[0032] 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 no particular 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.

[0033] 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).

[0034] 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.

[0035] The index data of the samples of Examples 1-3 are shown in the following table:

[0036] The active ingredient content data of Comparative Examples 1-2 are shown in the following table

[0037] 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 97%; 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.

[0038] 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.

[0039] No cooling equipment was used during grinding of the sample in Comparative Example 2, and the highest grinding temperature reached about 90°C, and the local instantaneous temperature may be higher, which caused a significant decrease in the content of the two active ingredients; and the melting points of the two active ingredients were not high. The heat generated during the grinding process caused part of the original drug to melt, and the viscosity of the slurry increased sharply to form a paste-like substance, which seriously affected the fluidity, increased the grinding resistance, reduced the efficiency of the sand mill, prolonged the production time, and ultimately affected the stability of the suspension.

[0040] 3. Field trials Experimental design (according to GB / T 17980.52-2000) Test sites: Shouguang City, Shandong Province (cabbage fields, diamondback moth and beet armyworm, May-August), Zhoushan City, Zhejiang Province (rice fields, striped stem borer, July-August) Cell area: 30 m² (5m×6m), 0.5m interval; Drugs used: Example 1-3 suspension, 2% avermectin suspension, 5% indoxacarb suspension Application method: dilute the agent 800 times, spray 50 L per mu, and apply the agent twice continuously (10 days apart).

[0041] Data on the efficacy and duration of the tested pesticides against diamondback moth, beet armyworm and striped stem borer:

[0042] 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 a longer effective period. After dilution with water in the field, the dumping residue is ≤0.5%, meeting the national standard requirements.

[0043] 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 avermectin and indoxacarb, characterized in that: Calculated by mass percentage, it contains 1.0-3.5% of avermectin, 5-12% of indoxacarb, 2-5% of dispersant, 2-5% of wetting agent, 1.5-3% of thickener, 0.1-0.5% of preservative, 2-5% of antifreeze agent, 0.3-0.8% of pH regulator, 0.1-0.5% of defoamer, and the content is made up to 100% with deionized water; The thickener is a compound of xanthan gum, magnesium aluminum silicate and white carbon black, the antifreeze agent is ethylene glycol, the mass ratio of xanthan gum, magnesium aluminum silicate and white carbon black is 0.15-0.2:0.8-1.2:0.8-1.2, and the mass ratio of xanthan gum to ethylene glycol is 0.15-0.2:

4.

2. A suspension concentrate containing avermectin 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 avermectin and indoxacarb according to claim 2, characterized in that: The dispersant is a polycarboxylate.

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

6. A suspension concentrate containing avermectin 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 avermectin and indoxacarb according to claim 1, characterized in that: The preservative may be selected from one or more of benzisothiazolinone, sodium benzoate, formaldehyde, polyoxymethylene, sodium citrate, sodium salicylate, potassium sorbate, and kasone; the pH adjuster may be selected from one or more of glacial acetic acid, citric acid, boric acid, and dilute hydrochloric acid.

8. A method for preparing a suspension concentrate containing avermectin 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. Emamectin and indoxacarb are added, and the shearing is continued; (2) firstly add xanthan gum to antifreeze agent ethylene glycol and stir and disperse to form a dispersion, then add the xanthan gum together with a preservative and two other thickeners, magnesium aluminum silicate and white carbon black, to the mixture obtained in step (1), continue shearing, add a pH adjuster, and stir 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 avermectin 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 avermectin and indoxacarb according to any one of claims 1 to 7 or a suspension concentrate containing avermectin 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 diamondback moth, beet armyworm and rice stem borer.

Images