A stable and efficient pyrethrum insecticidal composition and a preparation method thereof

Abstract

The present application relates to the field of pesticide composition, especially to a stable and efficient pyrethrum insecticide composition and its preparation method. The composition comprises at least 1-10wt% of pyrethrum, 1-25wt% of the second active substance, 5-25wt% of functional adjuvant and the rest of solvent. The composition provided in the present application is different from the existing water dispersible granules, emulsifiable concentrate and suspension concentrate of pyrethrum and acetamiprid combination, which is a soluble concentrate composition with extremely high active ingredient content. The composition has obvious advantages in drug efficacy compared with solid preparations, and is more environmentally friendly than the existing emulsifiable concentrate type, and has excellent market prospect in the field of pesticides.

Description

Technical Field

[0001] This invention relates to the field of pesticide compositions (A01N27 / 00), and more particularly to a stable and highly effective cypermethrin insecticidal composition and its preparation method. Background Technology

[0002] Cypermethrin, also known as cypermethrin, is an insecticide that works by inhibiting the transmission of signals at the axonal sites of insects, thereby exerting repellent, knockdown, and toxic effects. In recent years, due to its excellent broad-spectrum insecticidal activity, high insecticidal activity, and resistance to rain washout, cypermethrin has been widely used in insecticidal pesticide compositions.

[0003] Existing technology, Chinese patent CN111096329A, provides a microcapsule suspension containing cypermethrin and neonicotinoid insecticidal active ingredients. It claims to effectively improve the insecticidal activity of the composition through the combination of synergistic adjuvants and improvements in the preparation process. Furthermore, it states that the preparation of microcapsule formulations can be carried out under milder conditions and with easier process control, thus meeting the needs of continuous industrial production. However, microcapsule formulations are prone to rupture, making them unsuitable for use with other pesticides, thus limiting their application areas and environments. Cypermethrin has a low melting point, making it unsuitable for use as a suspension in actual preparation. Additionally, the suspension formulation has a high viscosity and poor flowability, making it prone to stratification, precipitation, and agglomeration during storage. Moreover, it fails to address the risks of composition instability and reduced efficacy caused by the translocation of cypermethrin.

[0004] Therefore, in order to solve the above problems, this application provides a stable and efficient cypermethrin insecticidal composition, which yields a more stable soluble insecticidal composition and can effectively inhibit the translocation of cypermethrin in the system, thereby avoiding the decline in efficacy and stability. Summary of the Invention

[0005] The first aspect of this application provides a stable and highly effective cypermethrin insecticidal composition, comprising at least 1-10 wt% cypermethrin, 1-25 wt% a secondary active ingredient, 5-25 wt% a functional adjuvant, 5-15 wt% a cosolvent, and the balance being a solvent.

[0006] As a preferred embodiment, the second active ingredient is any one of thiamethoxam, acetamiprid, thiamethoxam, imidacloprid, acetamiprid, and flonicamid.

[0007] As a preferred embodiment, the second active ingredient is thiamethoxam or acetamiprid.

[0008] As a preferred embodiment, the second active ingredient is acetamiprid.

[0009] As a preferred embodiment, the mass ratio of cypermethrin to acetamiprid is 7-10:11-15.

[0010] As a preferred embodiment, the mass ratio of cypermethrin to acetamiprid is 8-9:12-14.

[0011] As a preferred embodiment, the mass ratio of cypermethrin to acetamiprid is 8:12.

[0012] As a preferred embodiment, the functional additive is at least one of emulsifier, antifreeze, and pH adjuster.

[0013] As a preferred embodiment, the emulsifier is a mixture of fatty alcohol polyoxyethylene ether and block copolymer.

[0014] As a preferred embodiment, the mass ratio of the fatty alcohol polyoxyethylene ether to the block copolymer is 14-18:2-6.

[0015] As a preferred embodiment, the mass ratio of the fatty alcohol polyoxyethylene ether to the block copolymer is 16:4.

[0016] As a preferred embodiment, the pH adjuster is at least one selected from phosphoric acid, hydrochloric acid, glacial acetic acid, acetic acid, sulfuric acid, and citric acid.

[0017] As a preferred option, the pH adjuster is glacial acetic acid or citric acid.

[0018] As a preferred embodiment, the pH adjuster is glacial acetic acid.

[0019] As a preferred embodiment, the co-solvent is any one of propylene carbonate, dimethyl carbonate, diethyl carbonate, and methyl ethyl carbonate.

[0020] As a preferred embodiment, the solvent is at least one selected from deionized water, N,N-dimethyloctyldecamide, N,N-dimethyldecamide, ethylene glycol butyl ether acetate, N,N-dimethylamide, N,N-dimethylpropionamide, cyclohexanone, solvent oil, dimethyl sulfoxide, n-butanol, ethanol, and methanol.

[0021] As a preferred embodiment, the functional additive includes at least an emulsifier and a pH adjuster; the cosolvent is propylene carbonate; the solvent is ethanol; and the mass ratio of the cosolvent to the solvent is 1–2:4–6.

[0022] As a preferred embodiment, the molar ratio of propylene carbonate, ethanol and glacial acetic acid is 1:4.2-5:0.04-0.06.

[0023] In this application, the use of a specific solvent and pH adjuster not only suppresses the translocation of cypermethrin in the present application, but also further improves the stability of the overall composition system, avoiding low-temperature precipitation and high-temperature discoloration. The applicant believes that when the ratio of propylene carbonate, ethanol, and glacial acetic acid is 1:4.2–5:0.04–0.06, propylene carbonate and ethanol can work together to encapsulate cypermethrin in the system, forming a good interfacial encapsulation system around the active ingredient, thereby suppressing excessive dispersion of cypermethrin in the system and its self-translocation; simultaneously, the addition of ethanol and glacial acetic acid can form a stable and homogeneous system under stable pH conditions, thus avoiding low-temperature precipitation.

[0024] As a preferred embodiment, the stable and highly effective cypermethrin insecticidal composition is formulated as a soluble concentrate.

[0025] The second aspect of the present invention provides a method for preparing the above-mentioned stable and efficient cypermethrin insecticidal composition, the steps of which include the following steps: (1) adding solvent to a preparation vessel, adding cypermethrin and the second active ingredient, stirring for 30 to 60 minutes until completely dissolved; (2) mixing the co-solvent and the functional additive, filtering after mixing, and obtaining the final product.

[0026] Beneficial effects:

[0027] 1. The cypermethrin insecticide composition provided in this application is different from the existing water-dispersible granules, emulsifiable concentrates and suspension concentrates of cypermethrin and acetamiprid. It is a soluble concentrate composition with extremely high active ingredient content. It has significantly better efficacy than solid formulations and suspension concentrates, and is also more environmentally friendly than existing emulsifiable concentrates. It has excellent market prospects in the pesticide field.

[0028] 2. The cypermethrin insecticidal composition provided in this application uses a combination of the active ingredients of cypermethrin and acetamiprid, which effectively improves the insecticidal effect of the composition. Compared with cypermethrin and acetamiprid used alone, it has a significant synergistic effect and can effectively control aphid diseases.

[0029] 3. The cypermethrin insecticide composition provided in this application uses a specific ethanol as one of the solvents in this application. It can not only be used as a solvent, but also effectively form a protective system at low temperatures, so as to promote the composition to achieve the best low-temperature stability. It can achieve zero precipitation at low temperatures and avoid the aggregation and crystallization of propylene carbonate at low temperatures.

[0030] 4. The cypermethrin insecticide composition provided in this application uses a specific propylene carbonate, which not only serves as a cosolvent for the composition, but also effectively protects the activity of cypermethrin under various environments, avoiding translocation and decomposition of cypermethrin under long-term storage conditions, thereby giving the composition excellent storage stability in both high and low temperature environments.

[0031] 5. The cypermethrin insecticide composition provided in this application uses a combination of specific solvents and pH adjusters, which not only inhibits the translocation of cypermethrin in this application, but also further improves the stability of the overall composition system, avoiding low-temperature precipitation and high-temperature discoloration. When the ratio of propylene carbonate, ethanol and glacial acetic acid is 1:4.2-5:0.04-0.06, propylene carbonate and ethanol can work together to form a good interfacial encapsulation system around the active ingredient, thereby inhibiting the excessive dispersion of cypermethrin in the system and the resulting translocation. At the same time, the addition of ethanol and glacial acetic acid can form a good stable and homogeneous system under the premise of stable pH. Attached Figure Description

[0032] Figure 1 The image shows the appearance of the composition prepared in Example 1 of this application after a high-temperature stability test.

[0033] Figure 2 The images show the appearance results of the compositions prepared in Example 1 (right) and Comparative Example 1 (left) of this application after low-temperature stability testing.

[0034] Figure 3 The images show the appearance results of the compositions prepared in Comparative Examples 2 (left 1), 3 (left 2), 4 (right 1), and 5 (right 2) after low-temperature stability testing.

[0035] Figure 4 The images show the appearance results of the compositions prepared in Example 1 (right 1) and Comparative Examples 6 (left 1), 7 (left 2), and 8 (right 2) after high-temperature stability testing.

[0036] Figure 5 The images show the appearance results of the compositions prepared in Comparative Examples 9 (left 1), 10 (left 2), 11 (right 2), and 12 (right 1) after high-temperature stability testing. Detailed Implementation

[0037] Example 1

[0038] Example 1 provides a stable and efficient cypermethrin insecticidal composition, which, by weight percentage, comprises: 8% cypermethrin, 12% acetamiprid, 20.5% functional adjuvants, 10% cosolvent, and the balance being solvent replenishment.

[0039] The functional additives include 20% emulsifier and 0.5% pH adjuster. The emulsifier is a fatty alcohol polyoxyethylene ether and a block copolymer in a mass ratio of 16:4. The fatty alcohol polyoxyethylene ether was purchased from AEO-9 product sold by Kaiyuan Company, and the block copolymer was purchased from 500lq emulsifier product sold by Noryon. The pH adjuster is glacial acetic acid.

[0040] The cosolvent is propylene carbonate, and the solvent is ethanol, with a mass ratio of 1:4.95.

[0041] The second aspect of this embodiment provides a method for preparing the above-mentioned stable and efficient cypermethrin insecticidal composition: (1) Add the solvent to the preparation vessel, add cypermethrin and acetamiprid, stir for 45 min until completely dissolved; (2) Mix the co-solvent and functional additives, and after mixing, obtain a liquid product with pH 3.9 and filter it to obtain the final product.

[0042] Comparative Example 1

[0043] The specific implementation method of this comparative example is the same as that of Example 1, except that the content of the cosolvent propylene carbonate is 5%, because the remaining components due to the adjustment of the cosolvent content are supplemented by ethanol solvent.

[0044] Comparative Example 2

[0045] The specific implementation method of this comparative example is the same as that of Example 1, except that: the content of the cosolvent propylene carbonate is 4%, the solvent is N,N-dimethylpropionamide, and the remaining components due to the adjustment of the cosolvent content are supplemented by N,N-dimethylpropionamide solvent.

[0046] Comparative Example 3

[0047] The specific implementation method of this comparative example is the same as that of Example 1, except that the solvent is cyclohexanone.

[0048] Comparative Example 4

[0049] The specific implementation method of this comparative example is the same as that of Example 1, except that the content of the cosolvent propylene carbonate is 20%, and the content of other components other than the solvent remains unchanged.

[0050] Comparative Example 5

[0051] The specific implementation method of this comparative example is the same as that of Example 1, except that the content of the cosolvent propylene carbonate is 30%, and the content of other components other than the solvent remains unchanged.

[0052] Comparative Example 6

[0053] The specific implementation method of this comparative example is the same as that of Example 1, except that the solvent is solvent oil and ethanol, and the mass ratio of the two is 1:3.95.

[0054] Comparative Example 7

[0055] The specific implementation method of this comparative example is the same as that of Example 1, except that the solvent is cyclohexanone and ethanol, and the mass ratio of the two is 1:3.95.

[0056] Comparative Example 8

[0057] The specific implementation method of this comparative example is the same as that of Example 1, except that the solvent is methanol and ethanol, and the mass ratio of the two is 1:3.95.

[0058] Comparative Example 9

[0059] The specific implementation method of this comparative example is the same as that of Example 1, except that the pH adjuster is 0.5% dilute hydrochloric acid aqueous solution (10wt%).

[0060] Comparative Example 10

[0061] The specific implementation method of this comparative example is the same as that of Example 1, except that the pH adjuster is 0.5% citric acid.

[0062] Comparative Example 11

[0063] The specific implementation method of this comparative example is the same as that of Example 1, except that the pH adjuster is 0.25% glacial acetic acid.

[0064] Comparative Example 12

[0065] The specific implementation method of this comparative example is the same as that of Example 1, except that the pH adjuster is 0.5% phosphoric acid.

[0066] Performance Evaluation

[0067] I. Toxicity testing:

[0068] Experimental target: Peach aphid, collected from a vegetable greenhouse in Gangji Town, Hefei City, Anhui Province, and reared indoors for two generations.

[0069] Culture conditions: Peach aphids were reared with cabbage. The temperature in the artificial climate chamber was 26±1℃, the light:dark ratio was 16h:8h, the light intensity was 2000 lux, and the relative humidity was 75±5%RH. Wingless adult aphids with uniform growth were selected for use.

[0070] Experimental reagents: Cypermethrin technical grade, 95% concentration, sourced from Shanghai Yuelian Biotechnology Co., Ltd.; Acetamiprid technical grade, 99% concentration, sourced from Shanghai Yuelian Biotechnology Co., Ltd.; Other reagents: Acetone, Tween 80, etc.

[0071] Experimental treatment method: The two original drugs were dissolved in acetone and prepared into high-concentration stock solutions. These stock solutions were then diluted with 0.1% Tween 80 aqueous solution in a proportional series to obtain a series of concentrations. Experiments were conducted using different ratios of the two original drugs for mixing. The specific concentration treatments for each agent are shown in Table 1 below (each treatment was repeated 4 times, with 30 insects per replicate):

[0072] Table 1

[0073]

[0074] Test method: Insect immersion method. The mortality of the test insects was checked 48 hours after treatment. The total number of insects and the number of dead insects were recorded. The mortality standard was defined as the absence of reaction when the aphid's legs and antennae were gently touched with a paintbrush.

[0075] The aphid mortality rate and corrected mortality rate were calculated according to standard toxicity testing methods.

[0076] The results of the indoor bioassays are shown in Table 2 below:

[0077] Table 2

[0078]

[0079] The original data is shown in Table 3 below:

[0080] Table 3

[0081]

[0082] II. Field efficacy: The composition prepared in Example 1 of this application was subjected to field efficacy tests in five locations over two years.

[0083] (1) Heilongjiang Province, December 2019:

[0084] Test reagent: 20% cypermethrin-acetamiprid soluble solution (Example 1).

[0085] Comparative agents: 10% cypermethrin emulsion and 10% acetamiprid wettable powder, both sourced from Shanghai Hulian Chemical Co., Ltd.

[0086] Experimental site: Harbin, Heilongjiang Academy of Agricultural Sciences.

[0087] Experimental target: aphids.

[0088] Experimental crop: Chinese cabbage, Zhonggan 22. The previous crop in the experimental field was Chinese cabbage. Seedlings were raised in nutrient pots in the greenhouse on October 28 and transplanted to the greenhouse on November 28. The plant spacing was 25x30cm. Normal management was carried out after transplanting.

[0089] Test soil: black soil, organic matter content 2.7%, pH 6.9.

[0090] The weather conditions during the test are shown in Table 4 below:

[0091] Table 4

[0092]

[0093] The dosage and number of the medicines are shown in Table 5 below:

[0094] Table 5

[0095]

[0096] The community layout is as follows (Table 6)

[0097] Table 6

[0098] Repeat I 1 2 3 4 5 6 Repeat II 5 1 2 6 3 4 Repeat III 4 6 5 3 2 1 Repeat IV 6 5 4 2 1 3

[0099] Community area and overlap: The community is 4m long and 4.2m wide, with an area of ​​16.8m². 2 The number of repetitions is 4, and the arrangement is randomized.

[0100] Application: Spray application; application time is December 18th, during the aphid occurrence period, apply once, the amount of pesticide solution used in the area is 756 grams.

[0101] Survey Methodology:

[0102] Investigate the initial insect population before applying the pesticide, and investigate the number of live insects 2 days and 7 days after application.

[0103] Five points were randomly selected in each area, with six plants at each point, to investigate the number of live insects on the entire plant.

[0104]

[0105] PT0 - Number of insects before pesticide application in the pesticide-treated area; PT1 - Number of insects after pesticide application in the pesticide-treated area; CK0 - Number of insects before pesticide application in the blank control area; CK1 - Number of insects after pesticide application in the blank control area.

[0106] The efficacy results are shown in Table 7 below:

[0107] Table 7

[0108]

[0109] (2) Heilongjiang Province, June 2020:

[0110] The specific operation of this experiment was the same as that of (1) the Heilongjiang test in December 2019; the meteorological conditions during this test were recorded in Table 8 below:

[0111] Table 8

[0112]

[0113] The test results are shown in Table 9 below:

[0114] Table 9

[0115]

[0116] (3) Shanxi in December 2019

[0117] Test reagent: 20% cypermethrin-acetamiprid soluble solution (Example 1).

[0118] Comparative agents: 10% cypermethrin emulsion and 10% acetamiprid wettable powder, both sourced from Shanghai Hulian Chemical Co., Ltd.

[0119] Experimental site: Juxin Industrial Park, Taigu County, Shanxi Province.

[0120] Experimental target: aphids.

[0121] Experimental crop: Cabbage, Zhonggan 22.

[0122] Test soil: loam, with moderate organic matter content and no intercropping, pH 8.0.

[0123] The weather conditions during the test are shown in Table 10 below:

[0124] Table 10

[0125]

[0126] The dosage and number of the medicines are shown in Table 11 below:

[0127] Table 11

[0128]

[0129] The community is arranged as shown in Table 12 below:

[0130] Table 12

[0131]

[0132] Area and overlap: The area is 4.0m × 2.0m = 8m 2The number of repetitions is 4.

[0133] Application of pesticide: The pesticide was applied on December 13, 2019, once during the initial peak of aphid infestation. The pesticide was sprayed, with a pesticide solution volume of 50 liters per acre.

[0134] Survey Methodology:

[0135] Investigate the initial insect population before applying the pesticide, and investigate the number of live insects 2 days and 7 days after application.

[0136] Five points were randomly selected in each community, with three plants at each point, to investigate the number of live insects on the entire plant.

[0137]

[0138] PT0 - Number of insects before pesticide application in the pesticide-treated area; PT1 - Number of insects after pesticide application in the pesticide-treated area; CK0 - Number of insects before pesticide application in the blank control area; CK1 - Number of insects after pesticide application in the blank control area.

[0139] The efficacy results are shown in Table 13 below:

[0140] Table 13

[0141]

[0142] (4) Shanxi in July 2020

[0143] The specific operation of this experiment was the same as that of the Shanxi test in December 2019 (3); the application time was July 13 and the end time was July 20; the meteorological conditions during this test were recorded in Table 14 below:

[0144] Table 14

[0145]

[0146] The test results are shown in Table 15 below:

[0147] Table 15

[0148]

[0149] (5) Shanghai, December 2019

[0150] Test reagent: 20% cypermethrin-acetamiprid soluble solution (Example 1).

[0151] Comparative agents: 10% cypermethrin emulsion and 10% acetamiprid wettable powder, both sourced from Shanghai Hulian Chemical Co., Ltd.

[0152] Experimental site: Vegetable base in Xujiacao Village, Xinbang Town, Songjiang District, Shanghai; contractor: Shen Dehua; planting in a greenhouse with an area of ​​320m². 2The plant is 40m long and 80m wide, divided into 4 beds 2m wide. It was transplanted on October 8 and sprayed with pesticide on December 18.

[0153] Experimental targets: aphids, specifically the turnip aphid and the cabbage aphid.

[0154] Experimental crop: Cabbage, variety: Atomi.

[0155] The treatment and numbering of the test reagents are shown in Table 16 below.

[0156] Table 16

[0157]

[0158] Area of ​​the residential complex: 6m × 2m = 12m 2 Six processes were set up, each repeated four times, for a total of 24 cells.

[0159] The neighborhoods are arranged as shown in Table 17:

[0160] Table 17

[0161]

[0162] Application of pesticide: The pesticide was applied on December 18, 2019, once during the initial peak of aphid infestation. The pesticide was sprayed at a rate of 55 liters per acre.

[0163] The weather conditions during the experiment are shown in Table 18:

[0164] Table 18

[0165]

[0166] Survey Methodology:

[0167] Before applying the pesticide, investigate the initial insect population. After applying the pesticide, investigate the number of live insects once each at 2, 7, and 12 days.

[0168] Five points were randomly selected in each community, with two plants at each point. The number of aphids on two leaves of each plant was recorded, and the number of aphids was counted in units of 5 during the survey.

[0169]

[0170] PT0 - Number of insects before pesticide application in the pesticide-treated area; PT1 - Number of insects after pesticide application in the pesticide-treated area; CK0 - Number of insects before pesticide application in the blank control area; CK1 - Number of insects after pesticide application in the blank control area.

[0171] The preventive efficacy is shown in Table 19 below:

[0172] Table 19

[0173]

[0174] (6) Shanghai, May 2020

[0175] The specific operation of this experiment was the same as that of the Shanghai test in December 2019 (5); the application time was May 12 and the end time was May 26.

[0176] The difference is that the crop used in this experiment was cabbage-early summer sixteen, and the experimental subjects were cabbage aphid and peach aphid, mainly peach aphid.

[0177] The residential communities are shown in Table 20 below:

[0178] Table 20

[0179] District Group 1 District Group 2 District Group 3 Block 4 4 3 5 6 2 5 4 1 6 1 3 2 3 2 1 4 1 6 6 5 5 4 2 3

[0180] The area of ​​the residential area is 15m² 2 Repeat 4 times.

[0181] The amount of pesticide solution applied is 30 liters per mu.

[0182] The investigation points were 3 days, 7 days and 14 days after the application of the medication.

[0183] The weather conditions during the experiment are shown in Table 21 below:

[0184] Table 21

[0185]

[0186] The results of the efficacy test are shown in Table 22 below:

[0187] Table 22

[0188]

[0189] (7) In 2019, Hainan and (8) in 2020, Sichuan used the same methods as (1) to (6) above to conduct efficacy tests in Hainan in 2019 and Sichuan in 2020.

[0190] The weather conditions in Hainan during the 2019 testing period are shown in Table 23:

[0191] Table 23

[0192]

[0193] The results of the 2019 Hainan test for disease prevention efficacy are shown in Table 24:

[0194] Table 24

[0195]

[0196] The weather conditions in Sichuan during the testing period in 2020 are shown in Table 25:

[0197] Table 25

[0198]

[0199] The results of the 2020 Sichuan test on the effectiveness of the disease control are shown in Table 26.

[0200] Table 26

[0201]

[0202] The results of the two-year, five-location experiment are summarized in Table 27:

[0203] Table 27

[0204]

[0205] a: Control 1 was 10% high-efficiency cypermethrin emulsion;

[0206] b: Control 2 is acetamiprid wettable powder;

[0207] c: In Sichuan, the preventive effect is measured one day after the medication is applied.

[0208] III. Physicochemical Properties:

[0209] (1) Low-temperature stability: Low-temperature stability tests for thermal storage were conducted according to GB / T 19137-2003, with the test temperature changed from 0±2℃ to -6±2℃. The test results for Example 1 and Comparative Examples 1-5 are as follows: Figures 2-3 As shown.

[0210] (2) Thermal storage stability: Thermal storage experiments were conducted in accordance with the standard GB / T 19136-2003. The test results of Example 1 and Comparative Examples 6-12 are as follows: Figure 1 and Figures 4-5 As shown.

Claims

1. A stable and highly effective pyrethroid insecticide composition, characterized in that: The ingredients include 8 wt% cypermethrin, 12 wt% acetamiprid, 20.5 wt% functional adjuvants, 10 wt% solubilizer, and the remaining amount of solvent. The stable and efficient cypermethrin insecticidal composition is formulated as a soluble concentrate. The functional additives consist of 20% emulsifier and 0.5% pH adjuster; the pH adjuster is glacial acetic acid. The co-solvent is propylene carbonate; the solvent is ethanol; the mass ratio of the co-solvent to the solvent is 1:4.95; The emulsifier is a mixture of fatty alcohol polyoxyethylene ether and block copolymer, with a mass ratio of 16:

4.

2. A method for preparing the stable and efficient cypermethrin insecticidal composition according to claim 1, characterized in that: The steps include the following steps: (1) Add the solvent to the preparation vessel, add cypermethrin and the second active ingredient, stir for 30-60 minutes until completely dissolved; (2) Mix the cosolvent and functional additives, filter after mixing, and obtain the product.

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