Pesticide suspending agent composition and preparation method thereof

Abstract

The invention provides a pesticide suspending agent composition and a preparation method thereof. The suspending agent comprises indoxacarb and other insecticides as active components, a compound thickening agent is used and matched with a specific anti-freezing agent, and proper raw material adding sequence, preparation steps, shearing time, grinding temperature and other process parameters are determined. The conditions of huddling or caking, active ingredient decomposition and the like easily occurring in the preparation process of the suspending agent are avoided, and the method is suitable for large-scale industrial production.

Description

Technical Field

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

[0002] Pesticide suspension concentrate (SC, usually referred to as suspension concentrate) is a stable suspension system that evenly disperses the active ingredients of solid pesticides in the aqueous phase. It has the advantages of environmental protection, long-lasting efficacy, and easy 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 adjuvant is not properly selected or the process parameters are unreasonable, it is easy to produce clumping or agglomeration, decomposition of active ingredients, etc. during the preparation process, affecting the fluidity, stability and efficacy of the preparation.

[0003] 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. 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.

[0004] Chlorfenapyr, chemical name is 4-bromo-2-(4-chlorophenyl)-1-ethoxymethyl-5-trifluoromethylpyrrole-3-carbonitrile, molecular formula is C 15 H 11 BrClF3N2O, molecular weight 407.62, melting point 100-104℃, slightly soluble in water, easily soluble in organic solvents such as acetone, ether, methanol, stable at room temperature, sensitive to light. Chlorfenapyr can be used for vegetables, cotton, fruit trees, grapes and other plants to control lepidopteran pests (such as diamondback moth, beet armyworm), mites, thrips, etc. Common dosage forms include suspension, emulsifiable concentrate, water-dispersible granules, etc.

[0005] Chlorantraniliprole, chemical name is 3-bromo-N-(4-chloro-2-methyl-6-((methylcarbamoyl)benzene)-1-(3-chloropyridin-2-yl)-1-hydrogen-pyrazole-5-carboxamide, molecular formula is C 18 H 14 BrCl2N5O2, molecular weight 483.15, melting point 208-210℃, extremely low solubility in water (1.023 mg / L), soluble in acetone, methanol, etc., stable at high temperature, low hydrolysis. Chlorantraniliprole can be used in rice, corn, vegetables, fruit trees, etc. to control lepidopteran pests (such as rice leaf roller, striped stem borer), some beetles and whiteflies. Common formulations include suspensions, granules, etc.

[0006] Tolfenpyrad, chemical name is 4-chloro-3-ethyl-1-methyl-N-{(4-(4-methylphenoxy)phenyl)-methyl}-1H-pyrazole-5-carboxamide, molecular formula is C 21 H 22 ClN3O2, molecular weight 383.9, melting point 87.8-88.2℃, slightly soluble in water (0.087 mg / L), easily soluble in organic solvents such as toluene and acetone, stable at pH 4-9. Tolfenpyrad can be used for vegetables, fruit trees, cotton, tea, etc. to control Lepidoptera, Hemiptera, mites, etc., mainly by contact killing. Common formulations include emulsifiable concentrates, suspensions, etc.

[0007] Lufenuron, chemical name: N-carbamoyl-2,6-difluorobenzamide, molecular formula: C 17 H8Cl2F8N2O3, molecular weight 511.15, melting point 164.7-167.7℃, almost insoluble in water (<0.006 mg / L), soluble in acetone and methanol, stable to light, low hydrolysis (pH 5-9). Lufenuron can be used for vegetables, cotton, corn, citrus, etc. to control lepidopteran larvae (such as diamondback moth, cotton bollworm), thrips, rust mites, etc. Common formulations include emulsifiable concentrates and suspensions.

[0008] Indoxacarb has been used in the field for a long time. In order to delay the development of drug resistance, indoxacarb can be compounded with other insecticides. On the other hand, indoxacarb itself has a low melting point. The melting points of fenpropiamide and tolfenpyrad are similar to indoxacarb, while the melting points of chlorfenapyr and lufenuron are slightly higher. When preparing the suspension, indoxacarb is easily decomposed due to the high temperature during the grinding process, and the heat generated during the grinding process will cause part of the low-melting-point original drug to melt, the slurry viscosity increases sharply, and a paste-like substance is formed, which seriously affects the fluidity, increases the grinding resistance, reduces the grinding efficiency, and prolongs the production time.

[0009] There are many patent documents in the prior art that disclose pesticide suspensions related to the present invention, but most of them only provide simple formulas, but do not provide corresponding quality control index data, and do not pay attention to the problems of raw material agglomeration, caking, active ingredient decomposition, etc. that may occur in large-scale industrial production. Summary of the invention

[0010] In order to delay the generation of drug resistance due to long-term single use of indoxacarb and avoid the problems of decomposition of active ingredients and low grinding efficiency in the preparation process of suspension concentrate, the present invention provides a pesticide suspension concentrate composition, which comprises, by weight percentage, 10-15% of active ingredient A, 5-10% of active ingredient B, 2-10% 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 100% of deionized water.

[0011] The active ingredient A is one or more of chlorfenapyr, chlorantraniliprole, tolafenamide, and lufenuron, the active ingredient B is indoxacarb, the thickener is a compound of xanthan gum and magnesium aluminum silicate, the antifreeze agent is ethylene glycol, wherein the mass ratio of xanthan gum to magnesium aluminum silicate is 0.15-0.2:0.8-1.0, preferably 0.15:0.8; the mass ratio of xanthan gum to ethylene glycol is 0.15-0.2:4, preferably 0.15:4.

[0012] Preferably, the dispersant can be selected from one or more of polycarboxylates, phosphates, polyether sulfates, lignin sulfonates, alkylnaphthalene formaldehyde condensate sulfonates, polymer comb copolymers, sodium lauryl polyoxyethylene ether sulfate, cresol-formaldehyde sodium salt concentrates, sodium dodecyl sulfate, benzene sulfonates, ethoxyphenol ether sulfonates, modified polyacrylate copolymers, dodecyl polyoxyethylene ether phosphates, sulfate polyether multi-complexes, and the like.

[0013] Preferably, the wetting agent can be selected from one or more of EO-PO block copolymers, diisopropylnaphthalene sulfonates, fatty alcohol polyoxyethylene ethers, phosphates, nonylphenol polyoxyethylene ethers, alkyl polyoxyethylene ethers, phenethyl phenylpropylphenol polyoxyethylene ethers, pull-opening powder, sodium dodecylbenzene sulfonate, and the like.

[0014] 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.

[0015] Preferably, the preservative can be selected from one or more of benzisothiazolinone, sodium benzoate, formaldehyde, polyoxymethylene, sodium citrate, sodium salicylate, potassium sorbate, and kasone.

[0016] 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, the shearing is continued, and active ingredients A and B are added, and the shearing is continued to obtain a mixture; (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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] On the other hand, the inventors have found in practice that indoxacarb is easily decomposed during processing, resulting in a decrease in the active ingredient content of the finished product. Without being bound by any theory, the inventors believe that this is due to the excessively high temperature during the sand milling process. In addition, the heat generated during the grinding process will also cause some low-melting-point original drugs to melt, the viscosity of the slurry will increase sharply, and a paste-like substance will be formed, which will seriously affect the fluidity, increase the grinding resistance, reduce the efficiency of the sand mill, and prolong the production time.

[0021] 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.

[0022] 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 order and method of adding raw materials, 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.

[0023] (2) The suspension concentrate of the present invention has good stability, significant efficacy, long lasting effect, and is safe for crops and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] 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.

[0025] Figure 1 This is a flow chart of the suspension slurry production process of Formulation Example 1, Figure 2 This is a flow chart of the grinding production process of Formulation Example 1. DETAILED DESCRIPTION

[0026] The present invention is further explained below in conjunction with specific implementation modes.

[0027] 1. Preparation Examples Example 1: 20% chlorfenapyr·indoxacarb suspension Recipe ingredients:

[0028] The preparation method is as follows: (1) Under shearing conditions, EO-PO block copolymer wetting agent, polycarboxylate dispersant, high molecular weight comb copolymer dispersant, and silicone defoamer were added to deionized water, and the shearing was continued for 5 minutes. Afenacet 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] For details, please refer to the attached Figure 1 and 2 Preparation process flow chart.

[0030] Quality Control Indicators

[0031] Example 2: 20% chlorantraniliprole·indoxacarb suspension Recipe ingredients:

[0032] The preparation method is as follows: (1) under shearing conditions, adding a phosphate anionic wetting agent, a benzenesulfonate anionic dispersant, and a silicone defoaming agent to deionized water, continuing shearing for 5 minutes, adding chlorantraniliprole and indoxacarb, and continuing shearing 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.

[0033] Quality Control Indicators

[0034] Example 3: 22.5% Tolfenpyrad·Indoxacarb SC Recipe ingredients:

[0035] The preparation method is as follows: (1) under shearing conditions, adding a polycarboxylate dispersant, a comb copolymer dispersant, an EO-PO block copolymer wetting agent, and a silicone defoamer to deionized water, continuing shearing for 5 minutes, adding tolfenpyrad and indoxacarb, and continuing shearing 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 xanthan gum together with the preservative BIT and the thickener magnesium aluminum silicate 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.

[0036] Quality Control Indicators

[0037] Example 4: 18% Lufenuron-Indoxacarb Suspension Recipe ingredients

[0038] The preparation method is as follows: (1) under shearing conditions, adding a cresol-formaldehyde sodium salt concentrate dispersant, a phosphate dispersant, an EO-PO block copolymer wetting agent, and a silicone defoamer to deionized water, and continuing shearing for 5 minutes, adding lufenuron and indoxacarb, and continuing shearing 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 xanthan gum together with the preservative BIT and the thickener magnesium aluminum silicate 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.

[0039] Quality Control Indicators

[0040] It can be seen from the above data that the samples of the embodiments of the present invention all meet the general requirements of pesticide suspensions. Combined with the observations and tests during the preparation process, if all active ingredients are added together, or added one after another regardless of order, the components often clump or agglomerate in the container, and it is difficult to shear to form a uniform suspension slurry. After the suspension slurry is transferred to the sand mill, there are obviously more blocky viscous materials remaining at the bottom and wall of the container, which are difficult to clean. This is the main reason for the decrease in the content of active ingredients. Although the residual materials can be cleaned up additionally, it will seriously reduce the production efficiency during production, and there are also safety hazards, so large-scale industrialization is carried out.

[0041] If cooling equipment is not used during grinding, the maximum grinding temperature will reach about 90°C, and the local instantaneous temperature will be higher, which will cause the active ingredient content to decrease. Indoxacarb, cypermethrin and tolfenpyrad have low melting points, while chlorfenapyr and lufenuron have slightly higher melting points. The heat generated during the grinding process causes part of the original drug to melt, and the slurry viscosity increases sharply to form a paste-like substance, which seriously affects fluidity, increases grinding resistance, reduces grinding efficiency, and prolongs production time.

[0042] Example 5: Field Trial Experimental design (according to GB / T 17980.52-2000) Test sites: Shouguang, Shandong (spinach fields, beet armyworm, July-September), Zhoushan, Zhejiang (rice fields, rice leaf roller, May-June), Hangzhou, Zhejiang (tea gardens, tea green leafhopper, July-August) Cell area: 30 m² (5m×6m), 0.5m interval; Used medicine: Example 1-4 suspension Application method: dilute the agent 800 times, spray 50 L per mu, and apply the agent twice continuously (10 days apart).

[0043] Test results

[0044] It can be seen that the pesticides in the embodiments of the present application can effectively prevent and control piercing-sucking pests such as beet armyworm, rice leaf roller, tea green leafhopper, etc., and the effective period is about 40 days.

[0045] 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 pesticide suspension composition, characterized in that: Calculated by mass percentage, it contains active ingredient A 10-15%, active ingredient B 5-10%, dispersant 2-10%, wetting agent 1-3%, thickener 0.8-1.5%, antifreeze 2-5%, defoamer 0.1-0.5%, preservative 0.1-0.5%, and deionized water makes up 100%; The active ingredient A is one or more of chlorfenapyr, chlorfenapyr, tolafenamide, and lufenuron, the active ingredient B is indoxacarb, the thickener is a compound of xanthan gum and magnesium aluminum silicate, the antifreeze agent is ethylene glycol, the mass ratio of xanthan gum to magnesium aluminum silicate is 0.15-0.2:0.8-1.0, and the mass ratio of xanthan gum to ethylene glycol is 0.15-0.2:

4.

2. A pesticide suspension composition 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, high molecular comb copolymers, sodium lauryl polyoxyethylene ether sulfate, cresol-formaldehyde sodium salt concentrates, sodium dodecyl sulfate, benzene sulfonates, ethoxyphenol ether sulfonates, modified polyacrylate copolymers, dodecyl polyoxyethylene ether phosphates, and sulfate polyether multi-complexes.

3. A pesticide suspension composition 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, phosphate, nonylphenol polyoxyethylene ether, alkyl polyoxyethylene ether, phenylethyl phenylpropylphenol polyoxyethylene ether, pull-opening powder, sodium dodecylbenzene sulfonate.

4. A pesticide suspension composition 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.

5. A pesticide suspension composition 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.

6. A method for preparing a pesticide suspension composition according to any one of claims 1 to 5, 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, the shearing is continued, and active ingredients A and B are added, and the shearing is continued to obtain a mixture; (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.

7. The method for preparing a pesticide suspension composition according to claim 6, 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.

8. Use of a pesticide suspension composition according to any one of claims 1 to 5 or a pesticide suspension composition prepared according to the preparation method of any one of claims 6 to 7 in controlling agricultural pests, characterized in that The agricultural pests include beet armyworm, rice leaf folder and tea green leafhopper.

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