Antioxidant emamectin benzoate missible oil pesticide and production process thereof

Abstract

The invention discloses an antioxidant emamectin benzoate missible oil pesticide and a production process thereof. Comprising 1 to 5 parts of emamectin benzoate, 1 to 3 parts of an antioxidant, 5 to 10 parts of an emulsifier, 60 to 80 parts of a solvent, 5 to 10 parts of a cosolvent and 50 to 80 parts of water, wherein the antioxidant comprises 0.5 to 1.5 parts of butylated hydroxytoluene and 0.5 to 1.5 parts of triphenyl phosphate; the solvent comprises 30 to 60 parts of cyclohexanone and 10 to 40 parts of N-methyl pyrrolidone; calcium dodecyl benzene sulfonate and castor oil polyoxyethylene ether are compounded according to the proportion of 1: 1.5 to serve as an emulsifying agent, a stable interfacial film can be formed between an oil phase and a water phase, di-tert-butyl-p-cresol and triphenyl phosphite added in the product synergistically exert the anti-oxidation effect, di-tert-butyl-p-cresol can provide hydrogen atoms, and the anti-oxidation effect is good. And the triphenyl phosphite can decompose peroxides generated in the oxidation process of the emamectin benzoate, so that the problem of drug effect oxidation reduction caused by storage is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of emamectin benzoate emulsifiable concentrate pesticide production, and particularly relates to an antioxidant emamectin benzoate emulsifiable concentrate pesticide and a production process thereof. Background Art

[0002] Emamectin benzoate (emamectin benzoate), a semi-synthetic antibiotic insecticide derived from avermectin, occupies an important position in modern agricultural pest control due to its unique mechanism of action and good insecticidal activity. It can effectively act on the nervous system of pests, interfere with the nerve conduction process, and thus cause paralysis and eventual death of the pests. Emamectin benzoate has an excellent control effect, especially on Lepidoptera pests such as diamondback moth, beet armyworm, cotton bollworm, etc.

[0003] Currently, the chemical structure of emamectin benzoate contains multiple unsaturated bonds and active groups, which makes its chemical properties extremely active and prone to oxidative decomposition reactions under light, high temperature and oxygen conditions. During actual storage and use, emamectin benzoate emulsifiable concentrate pesticides are usually affected by natural environmental factors. For example, if exposed to direct sunlight for a long time or stored in a high-temperature environment, the active ingredients of emamectin benzoate will quickly decompose, which not only seriously affects the control effect of the pesticide, but may also cause farmers to increase the amount and frequency of use of the pesticide, thereby increasing agricultural production costs and environmental pollution risks. Summary of the Invention

[0004] The object of the present invention is to provide an antioxidant emamectin benzoate emulsifiable concentrate pesticide and a production process thereof, so as to solve the problems raised in the above background technology.

[0005] To achieve the above-mentioned object, the present invention provides the following technical solution: an antioxidant emamectin benzoate emulsifiable concentrate pesticide, which comprises, by weight, 1-5 parts of emamectin benzoate, 1-3 parts of an antioxidant, wherein the antioxidant is composed of 0.5-1.5 parts of di-tert-butyl-p-cresol and 0.5-1.5 parts of triphenyl phosphite, 5-10 parts of an emulsifier, 60-80 parts of a solvent, wherein the solvent is composed of 30-60 parts of cyclohexanone and 10-40 parts of N-methylpyrrolidone, 5-10 parts of a cosolvent, and 50-80 parts of water.

[0006] Preferably, the composition comprises, by weight, 4 parts of emamectin benzoate, 2 parts of antioxidant consisting of 1 part of di-tert-butyl-p-cresol and 1.5 parts of triphenyl phosphite, 8 parts of emulsifier, 75 parts of solvent consisting of 45 parts of cyclohexanone and 30 parts of N-methylpyrrolidone, 8 parts of cosolvent, and 70 parts of water.

[0007] Preferably, the emulsifier is calcium dodecylbenzenesulfonate and castor oil polyoxyethylene ether compounded in a ratio of 1:1.5. Calcium dodecylbenzenesulfonate has a lipophilic alkyl chain and a hydrophilic sulfonate group, and castor oil polyoxyethylene ether contains a long-chain polyoxyethylene group and a castor oil group with a certain lipophilicity. After the two are compounded, they can effectively reduce the oil-water interfacial tension in the emulsifiable concentrate system, so that the oil droplets are evenly dispersed in the aqueous phase to form a stable emulsion structure, ensuring that emamectin benzoate and other ingredients are evenly distributed during use. Water plays a role in regulating the specific gravity in the system, so that the emulsifiable concentrate can be better mixed with water when diluted and used. At the same time, as a diluent, it reduces the concentration of other ingredients, making the product more in line with practical application requirements, and can reduce the amount of organic solvent used to a certain extent, reducing the impact on the environment.

[0008] Preferably, the cosolvent is methanol. The hydroxyl groups of the methanol molecules interact with the polar groups in the emamectin benzoate molecules, thereby increasing the solubility of the emamectin benzoate in the solvent, improving the dispersion stability of the emamectin benzoate in the entire emulsifiable concentrate system, and ensuring the uniformity of the pesticide quality. The mixing ratio of the cyclohexanone and N-methylpyrrolidone is 3:1.5. At this ratio, the solubility of the mixed solvent for the emamectin benzoate and other adjuvants is optimized, and the viscosity of the emulsifiable concentrate can be controlled within the range of 10-30 mPa·s (measured at 25°C). The volatility is moderate, which ensures that the solvent is not easily excessively volatilized during storage and can be quickly dispersed during use, thereby improving the use effect of the pesticide.

[0009] A production process for an antioxidant emamectin benzoate emulsifiable concentrate pesticide specifically comprises the following steps:

[0010] S1. Accurately weigh all raw materials by weight using an electronic balance with an accuracy of 0.01 part. Ensure that the purity of emamectin benzoate is ≥ 95% to ensure its stable and efficient insecticidal effect in the pesticide. The active group in its molecular structure is key to its toxicity to pests. Within this content range, the insecticidal effect is balanced with production costs and environmental impact. Other raw materials meet the corresponding quality standards. Check the integrity of the raw material packaging.

[0011] S2. Add the accurately measured solvent and cosolvent in sequence to a reactor with a stirring device, turn on the stirring device, stir at a speed of 200-300 r / min for 5-10 minutes, then slowly add emamectin benzoate under stirring, and continue stirring for 15-20 minutes until it is completely dissolved;

[0012] S3. Slowly and evenly add the pre-mixed antioxidant to the reactor, increase the stirring speed to 300-400 r / min, stir for 10-15 minutes, then add the emulsifier, maintain the stirring speed at 300-400 r / min, stir for 15-20 minutes to emulsify, and control the temperature in the reactor at 25-35°C during the emulsification process;

[0013] S4. Test the appearance, active ingredient content, emulsion stability, pH value and other indicators of the prepared emulsifiable concentrate pesticides. If they pass the test, they are packaged in a light-proof and dry environment.

[0014] Preferably, in step S2, the stirring speed is set to 250 r / min and the stirring time is 8 min, so that the solvent and the co-solvent are fully mixed, the emamectin benzoate is dissolved quickly and completely, and a stable homogeneous solution can be formed.

[0015] Preferably, in step S3, the stirring speed is 350 r / min and the stirring time is 12 min, so that the antioxidant is fully dispersed in the system and fully contacts with emamectin benzoate and other components.

[0016] Preferably, in step S3, the stirring speed is 350 r / min, the stirring time is 18 min, and the temperature in the reactor is controlled at 30° C., so that the emulsifier can form a stable interface film in the system, the emulsion particle size distribution is uniform, and the emulsion stability is optimal, thereby ensuring the stable performance of the pesticide during storage and use.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) The butylated 4-tetramethylol (BTP) and triphenyl phosphite added to this product work together to exert antioxidant effects. BTP can provide hydrogen atoms to block the free radical chain reaction of emamectin benzoate oxidation, and triphenyl phosphite can decompose the peroxides produced during the oxidation of emamectin benzoate, so that the active ingredients of the pesticide are stable during long-term storage, reducing the problem of decreased efficacy caused by oxidation due to storage.

[0019] (2) Calcium dodecylbenzenesulfonate and castor oil polyoxyethylene ether are mixed in a ratio of 1:1.5 as an emulsifier, which can form a stable interfacial film between the oil phase and the water phase, ensuring the uniform dispersion of the active ingredients of the pesticide during dilution and use, thereby improving the use effect.

[0020] (3) A solvent system composed of cyclohexanone and N-methylpyrrolidone is used. The two work synergistically and have good solubility for emamectin benzoate and other additives. At the same time, mixing cyclohexanone and N-methylpyrrolidone in a ratio of 3:1.5 can make the viscosity and volatility of the emulsifiable concentrate reach an ideal state. While ensuring the storage stability of the product, it is convenient for spraying in agricultural production, thereby improving the applicability of the pesticide. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a flowchart of the present invention. DETAILED DESCRIPTION

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0023] The present invention provides Figure 1 The production process of an antioxidant emamectin benzoate emulsifiable concentrate pesticide is shown;

[0024] Example 1

[0025] Raw material preparation: Use a professional electronic balance with an accuracy of 0.01 parts to weigh the raw materials to ensure high weighing accuracy. Accurately weigh 4 parts of 96% pure emamectin benzoate, 1 part of di-tert-butyl-p-cresol, 1.5 parts of triphenyl phosphite, and 3.2 parts of calcium dodecylbenzenesulfonate and 4.8 parts of castor oil polyoxyethylene ether in a ratio of 1:1.5. During the weighing process, use the tare function of the electronic balance to ensure the accuracy of each weighing. Inspect the appearance and color of the two emulsifiers to ensure that they are not damp and have no lumps.

[0026] Weigh 45 parts of cyclohexanone and 30 parts of N-methylpyrrolidone, check their transparency and odor before use to ensure good quality, weigh 8 parts of methanol as a co-solvent, and finally weigh 70 parts of deionized water to reduce the impact of impurities in the water on product quality. After weighing all raw materials, check the amount of each raw material again to ensure consistency with the formula.

[0027] Mixing and stirring: Clean and dry the stainless steel reactor with a stirring device to ensure that there are no residual impurities inside the reactor, and add 45 parts of cyclohexanone, 30 parts of N-methylpyrrolidone and 8 parts of methanol into the reactor in sequence. Turn on the stirring device, adjust the stirring blade to a suitable angle, set the stirring speed to 250r / min, and continue stirring for 8 minutes. During the stirring process, observe the mixing of the solvent and co-solvent through the observation window on the reactor to ensure that they are fully mixed and form a uniform liquid phase environment;

[0028] Then, while maintaining stirring, slowly add 4 parts of emamectin benzoate at a slower speed. When adding, try to evenly sprinkle the emamectin benzoate into the reactor to avoid caking or agglomeration. Continue stirring for 18 minutes. During this period, take out a small amount of sample from the reactor through a sampler every 3-5 minutes, and observe the dissolution of emamectin benzoate under a microscope until no emamectin benzoate particles can be seen in the microscope field of view and the solution is uniform and transparent. It is determined that the emamectin benzoate is completely dissolved, and a stable uniform solution is formed.

[0029] Adding antioxidants and emulsifiers: Slowly and evenly add 1 part of di-tert-butyl-p-cresol and 1.5 parts of triphenyl phosphite, which have been thoroughly mixed in a clean container, to the reactor. During the addition process, use auxiliary tools such as a funnel to ensure that all the antioxidants are added to the reactor without spilling. At the same time, quickly increase the stirring speed to 350 r / min, and replace the stirring blade with a turbine blade with stronger shear force. Stir for 12 minutes. During the stirring process, samples are taken from different positions in the reactor at regular intervals. The dispersion of the antioxidant is analyzed by high performance liquid chromatography-mass spectrometry to ensure that it is evenly dispersed in the system and fully in contact with emamectin benzoate and other ingredients.

[0030] Next, 3.2 parts of calcium dodecylbenzenesulfonate and 4.8 parts of castor oil polyoxyethylene ether were added. When adding, the two emulsifiers were first preliminarily mixed in a small container and then slowly added to the reactor. The stirring speed was kept constant at 350 r / min and the emulsification was carried out for 18 minutes. At the same time, the reactor was heated or cooled by circulating water through the temperature control system of the reactor to accurately control the temperature at 30°C. During the emulsification process, the emulsion was tested every 5 minutes using a laser particle size analyzer to observe the change in the emulsion particle size. When the emulsion particle size D50 reached 2-3 μm and the particle size distribution span was less than 1.2, it indicated that the emulsification effect was good and a stable emulsion system was formed.

[0031] Quality inspection and packaging: The prepared emulsifiable pesticides are subjected to comprehensive quality inspection. During the appearance inspection, the product is poured into a clean transparent glass container and observed under natural light. The product should be in a uniform and transparent liquid state, without abnormal phenomena such as stratification, precipitation, turbidity or suspended matter. High-performance liquid chromatography is used to detect the content of the active ingredient of emamectin benzoate. After passing the test, the product is placed in a brown plastic bottle in a light-proof, dry and well-ventilated environment, and then sealed with a sealing cap to ensure that the product is not affected by the external environment during storage.

[0032] Example 2

[0033] Preparation of raw materials: Also using an electronic balance with an accuracy of 0.01 parts, accurately weigh 3 parts of 95% pure emamectin, 0.8 parts of di-tert-butyl-p-cresol, 1.2 parts of triphenyl phosphite, 3 parts of calcium dodecylbenzenesulfonate and 4.5 parts of castor oil polyoxyethylene ether in a ratio of 1:1.5, 40 parts of cyclohexanone and 25 parts of N-methylpyrrolidone, and 7 parts of methanol as a cosolvent. Operate in a ventilated environment, check its purity, weigh 75 parts of deionized water for use, and after weighing, check the amount of raw materials again to ensure accuracy.

[0034] Mixing and stirring: prepare a clean and dry reactor, add 40 parts of cyclohexanone, 25 parts of N-methylpyrrolidone and 7 parts of methanol in sequence, turn on the stirring device, set the stirring speed to 230r / min, adjust the stirring blade to the appropriate angle, and stir for 7 minutes to fully mix the solvent and co-solvent. During the stirring process, observe the flow state and uniformity of the solution to ensure good mixing effect. Then, slowly add 3 parts of emamectin benzoate while stirring. Pay attention to controlling the speed when adding to avoid caking of emamectin benzoate. Continue stirring for 16 minutes. During this period, confirm that the emamectin benzoate is completely dissolved and the solution is uniform through sampling observation and microscopic detection.

[0035] Add antioxidants and emulsifiers: slowly add 0.8 parts of pre-mixed di-tert-butyl-p-cresol and 1.2 parts of triphenyl phosphite into the reactor, increase the stirring speed to 330 r / min, replace with a turbine stirring blade, and stir for 11 minutes. During the stirring process, regularly take samples from different positions of the reactor to detect the dispersion of the antioxidant to ensure that it is evenly dispersed in the system. Then add 3 parts of calcium dodecylbenzenesulfonate and 4.5 parts of castor oil polyoxyethylene ether, keep the stirring speed at 330 r / min unchanged, and stir for 16 minutes for emulsification. During the emulsification process, the temperature is controlled at 28°C by the temperature control system of the reactor. The emulsion particle size is detected every 5 minutes using a laser particle size analyzer. When the emulsion particle size D50 reaches 2-3 μm and the particle size distribution span is less than 1.3, it indicates that the emulsification effect is good.

[0036] Quality Inspection and Packaging: The product was quality-tested. Appearance inspection revealed a homogeneous, transparent liquid with no abnormalities. High-performance liquid chromatography (HPLC) assayed the active ingredient content of emamectin benzoate, which was 2.92 parts per million, meeting expectations. Emulsion stability testing revealed stability after a 200-fold dilution according to the standard and stabilization at 25°C ± 1°C for 48 hours. The pH value was 6.5, within the recommended range. After passing the test, the product was packaged in a dark, dry environment into a brown plastic bottle, sealed, and labeled with product information.

[0037] Comparative Example

[0038] The common emamectin benzoate emulsifiable concentrate pesticide on the market was selected as a comparative example, and the performance tests were performed on the antioxidant emamectin benzoate emulsifiable concentrate pesticide prepared in Example 1-2 and the emamectin benzoate emulsifiable concentrate pesticide of the comparative example:

[0039] The comparative test results of the antioxidant emamectin benzoate emulsifiable concentrate pesticide prepared by the present invention and the traditional emamectin benzoate emulsifiable concentrate pesticide are shown in Table 1 below:

[0040] Table 1 is a comparative test result table of the performance test of the antioxidant emamectin benzoate emulsifiable concentrate pesticide prepared in Example 1-2 and the traditional emamectin benzoate emulsifiable concentrate pesticide:

[0041]

[0042]

[0043] Test results and analysis

[0044] Antioxidant performance test results:

[0045] In Example 1, after aging for 10 days, the retention rate of the active ingredient of emamectin benzoate was 95%; after aging for 20 days, the retention rate was 92%; and after aging for 30 days, the retention rate was 88%.

[0046] In Example 2, after aging for 10 days, the retention rate of the active ingredient of emamectin benzoate was 94%; after aging for 20 days, the retention rate was 90%; and after aging for 30 days, the retention rate was 86%.

[0047] In the comparative example, after aging for 10 days, the retention rate of the effective component of emamectin benzoate was 80%; after aging for 20 days, the retention rate was 65%; and after aging for 30 days, the retention rate was 50%.

[0048] Analysis: The effective ingredient retention rate of the emamectin benzoate emulsifiable concentrate pesticides of Example 1 and Example 2 under high temperature and strong light environment is significantly higher than that of the comparative example, indicating that the antioxidant performance of the products of the present invention is significantly better than that of ordinary products on the market, and can effectively inhibit the oxidative decomposition of emamectin benzoate and extend the shelf life of the product.

[0049] Emulsion stability test results:

[0050] After being left to stand for 48 hours, the diluted emulsions of Example 1 and Example 2 remained uniform without any stratification, flocculation or precipitation.

[0051] After standing for 24 hours, the diluted emulsion of the comparative example showed obvious stratification, with a stratification volume ratio of about 1:4; and a small amount of flocculants precipitated at the bottom of the measuring cylinder.

[0052] Analysis: The emulsions of the products of Examples 1 and 2 have good stability, which can ensure that the active ingredients are evenly dispersed when diluted for use. However, the emulsion of the comparative example has poor stability, which will affect the use effect of the pesticide.

[0053] Results of determination of active ingredient content:

[0054] The initial emamectin benzoate content in Example 1 was 4%, and after 30 days of aging, the content was 3.52%.

[0055] The initial emamectin benzoate content in Example 2 was 3%. After 30 days of aging, the content was 2.58%.

[0056] The initial emamectin benzoate content of the comparative example was 3.5%, and after 30 days of aging, the content was 1.75%.

[0057] Analysis: Under the same aging conditions, the decrease in the active ingredient content of the emamectin benzoate emulsifiable concentrate pesticide in Examples 1 and 2 is significantly smaller than that in the comparative example, which once again proves that the active ingredient of the product of the present invention is more stable during storage.

[0058] Insecticidal effect test results:

[0059] On the first day after application, the insect population reduction rate in area A (Example 1) was 70%, the insect population reduction rate in area B (Example 2) was 65%, and the insect population reduction rate in area C (Comparative Example) was 50%.

[0060] On the third day after application, the insect population reduction rate in area A was 85%, the insect population reduction rate in area B was 80%, and the insect population reduction rate in area C was 60%.

[0061] On the 7th day after application, the insect population reduction rate in area A was 90%, the insect population reduction rate in area B was 85%, and the insect population reduction rate in area C was 70%.

[0062] Analysis: The emamectin benzoate emulsifiable concentrate pesticides prepared in Examples 1 and 2 are significantly better than the comparative example in terms of insecticidal effect, and can more effectively control the diamondback moth. Moreover, the advantages become more obvious over time. This is due to its stable active ingredient content and good emulsion stability, which ensures the continued effectiveness of the drug.

[0063] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An antioxidant emamectin benzoate emulsifiable concentrate pesticide, characterized in that, The invention comprises, by weight, 1-5 parts of emamectin benzoate, 1-3 parts of antioxidant composed of 0.5-1.5 parts of di-tert-butyl-p-cresol and 0.5-1.5 parts of triphenyl phosphite, 5-10 parts of emulsifier, 60-80 parts of solvent composed of 30-60 parts of cyclohexanone and 10-40 parts of N-methylpyrrolidone, 5-10 parts of cosolvent, and the balance is water.

2. a kind of antioxidant type emamectin benzoate emulsifiable concentrate pesticide according to claim 1, is characterized in that: In parts by weight, the invention comprises 4 parts of emamectin benzoate, 2 parts of antioxidant consisting of 1 part of di-tert-butyl-p-cresol and 1.5 parts of triphenyl phosphite, 8 parts of emulsifier, 75 parts of solvent consisting of 45 parts of cyclohexanone and 30 parts of N-methylpyrrolidone, 8 parts of cosolvent and 70 parts of water.

3. a kind of antioxidant type emamectin benzoate emulsifiable concentrate pesticide according to claim 1, is characterized in that: The emulsifier is prepared by mixing calcium dodecylbenzenesulfonate and castor oil polyoxyethylene ether in a ratio of 1:1.

5.

4. a kind of antioxidant type emamectin benzoate emulsifiable concentrate pesticide according to claim 1, is characterized in that: The cosolvent is methanol, and the mixing ratio of cyclohexanone and N-methylpyrrolidone is 3:1.

5.

5. a production technology of the antioxidant emamectin benzoate emulsifiable concentrate pesticide described in any one of claim 1-4, is characterized in that, The specific steps include: S1. Accurately weigh each raw material according to parts by weight using an electronic balance with an accuracy of 0.01 parts. Ensure that the purity of emamectin benzoate is ≥95%, that other raw materials meet the corresponding quality standards, and check the integrity of the raw material packaging. S2. Add the accurately measured solvent and cosolvent in sequence to a reactor with a stirring device, turn on the stirring device, stir at a speed of 200-300 r / min for 5-10 minutes, then slowly add emamectin benzoate under stirring, and continue stirring for 15-20 minutes until it is completely dissolved; S3. Slowly and evenly add the pre-mixed antioxidant to the reactor, increase the stirring speed to 300-400 r / min, stir for 10-15 minutes, then add the emulsifier, maintain the stirring speed at 300-400 r / min, stir for 15-20 minutes to emulsify, and control the temperature in the reactor at 25-35°C during the emulsification process; S4. Test the appearance, active ingredient content, emulsion stability, pH value and other indicators of the prepared emulsifiable concentrate pesticides. If they pass the test, they are packaged in a light-proof and dry environment.

6. the production technology of a kind of antioxidant type emamectin benzoate emulsifiable concentrate pesticide according to claim 5, is characterized in that: In step S2, the stirring speed is set to 250 r / min and the stirring time is 8 min, so that the solvent and the co-solvent are fully mixed, and the emamectin benzoate is dissolved quickly and completely to form a stable homogeneous solution.

7. the production technology of a kind of antioxidant type emamectin benzoate emulsifiable concentrate pesticide according to claim 5, is characterized in that: In step S3, the stirring speed is 350 r / min and the stirring time is 12 min, so that the antioxidant is fully dispersed in the system and fully contacts with emamectin benzoate and other components.

8. the production technology of a kind of antioxidant type emamectin benzoate emulsifiable concentrate pesticide according to claim 5, is characterized in that: In step S3, the stirring speed is 350 r / min, the stirring time is 18 min, and the temperature in the reactor is controlled at 30° C., so that the emulsifier can form a stable interface film in the system.

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