A kind of pyrethroid anti-evaporation aqueous emulsion and preparation method thereof
By using athrin anti-evaporation agent in pesticide water emulsion and inhibiting its precipitation through crystal inhibitors, the problem of evaporation loss during spraying of pesticide water emulsion is solved, and higher anti-evaporation performance and more stable product quality are achieved.
Patent Information
- Application Number
- CN202411989082.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2025-04-08
AI Technical Summary
The existing pesticide water emulsions have high chemical loss due to evaporation during spraying, and the use of anti-evaporators has problems affecting product quality and increasing costs.
The problem of easy crystallization of anti-evaporation agent is solved by miscible the anti-evaporation agent with the original drug and dissolved it with a solvent, and then inhibiting the precipitation of the anti-evaporation agent through a crystal inhibitor.
It improves the anti-evaporation performance of pesticide emulsion, reduces the loss of the agent, ensures the stability of product quality, reduces environmental pollution, and improves the spray effect and prevention and control effect.
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Abstract
Description
Technical Field
[0001] The invention belongs to the field of pesticide preparations, and particularly relates to a pyrethroid anti-evaporation aqueous emulsion and a preparation method thereof. Background Art
[0002] Pesticide emulsion in water, also known as concentrated emulsion, is a preparation formed by dispersing a water-insoluble liquid technical drug or a solid technical drug in a water-insoluble organic solvent in water. It is an opaque emulsion in appearance. The oil droplet size is ≤20um, and a relatively narrow particle size distribution of ≤3.5um is usually more stable. Common pesticide emulsion in water is oil-in-water type, that is, oil is the dispersed phase and water is the continuous phase.
[0003] Water-based emulsions are a new type of pesticide dosage form that is internationally recognized as environmentally safe. They include emulsifiers, stabilizers, solvents, antifreeze agents, thickeners and other ingredients. They are diluted with water when used, have good stability and effectiveness, and are widely used in agricultural production.
[0004] In pesticide emulsions, the role of emulsifiers is to reduce surface and interfacial tension, disperse and emulsify the oil phase into tiny oil droplets, suspend them in the water phase, and form an emulsion. The emulsifiers are orderly arranged on the surface of the oil droplets to form a film, with the polar end facing the water and the non-polar end facing the oil, relying on spatial barriers and electrostatic effects to stabilize the emulsion.
[0005] For a long time, my country's pesticide production and consumption capacity has been among the highest in the world. However, due to the backward use technology, the utilization rate of pesticides in my country is low. 70%-80% of pesticides are lost to the soil or drift into the environment, which not only wastes resources but also pollutes the environment. The evaporation phenomenon during the spraying of pesticides is also one of the factors affecting the utilization rate of pesticides. According to test statistics and simulation calculations, during the spraying process of water-based pesticides, the loss of pesticides due to evaporation accounts for 1.5%-16.8% of the total spraying amount. Therefore, the selection of adjuvants with anti-evaporation properties is one of the main methods to reduce evaporation and improve the control effect.
[0006] The anti-evaporation agents currently on the market have a great impact on product quality. When added to the product using ordinary methods, it will cause stratification of the product. Therefore, most anti-evaporation agents use the barrel mixing method, which increases the cost of product packaging and transportation, and is more cumbersome during use. Summary of the invention
[0007] In view of the shortcomings of the existing process technology, the present invention provides a pyrethroid anti-evaporation aqueous emulsion and a preparation method thereof.
[0008] Calculated by mass percentage, the pyrethroid anti-evaporation aqueous emulsion of the present invention comprises 0.1%-25% of the active ingredient pyrethroid, 5%-30% of the organic solvent, 2%-8% of the crystal inhibitor, 2%-8% of the anti-evaporation agent, 5%-15% of the emulsifying dispersant, 0.1%-3% of the thickener, 3%-8% of the co-emulsifier, 3%-8% of the antifreeze agent, and the rest is deionized water.
[0009] Preferably, the active ingredients include one or two of permethrin, cis-cypermethrin, S-bioallethrin, efficient cyfluthrin, high-efficiency cypermethrin, cyfluthrin, tetrathrin, tetrathrin, bifenthrin, efficient cyfluthrin, and cypermethrin.
[0010] Preferably, the emulsifying dispersant includes at least one of fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether, triphenyl phenol polyoxyethylene ether, triphenyl phenol polyoxyethylene polyoxypropylene ether, castor oil polyoxyethylene ether, fatty acid polyoxyethylene ether, sorbitan fatty acid ester, sorbitan fatty acid ester polyoxyethylene ether, alkylphenol formaldehyde condensate polyoxyethylene ether, calcium dodecylbenzene sulfonate 500#, arylphenol polyoxyethylene ether phosphate and salts thereof, nonylphenol polyoxyethylene ether phosphate and salts thereof, fatty alcohol polyoxyethylene ether phosphate and salts thereof, and arylphenol polyoxyethylene ether sulfate.
[0011] Preferably, the crystal inhibitor includes at least one of nonionic hydroxy polyethylene oxide block polyether, butanol block polyether phosphate, sodium lauryl alcohol polyether sulfate, novel grafted comb-like carboxylic acid phosphate, and novel comb-like polyoxyethylene polyoxypropylene block polyether.
[0012] Preferably, the solvent includes at least one of dimethyl carbonate, benzyl acetate, ethylene glycol tert-butyl ether, N-methylpyrrolidone, N,N-dimethylformamide, tributyl citrate, piperonyl ether, solvent oil 150#, propylene glycol ether, isopentyl citrate, ethyl acetate, n-butyl acetate, and dimethyl phthalate.
[0013] Preferably, the anti-evaporation agent includes at least one of basic acrylic resin, sodium tripolyphosphate, sodium hexametaphosphate, disodium hydrogen phosphate, stearic acid, isooctyl alcohol, palmitic acid, and capric acid.
[0014] Preferably, the antifreeze agent is selected from at least one of ethylene glycol, propylene glycol, polyethylene glycol and isopropanol.
[0015] Preferably, the thickener is selected from at least one of xanthan gum, cellulose and its derivatives, polyethylene glycol, magnesium aluminum silicate, bentonite, kaolin, diatomaceous earth and attapulgite.
[0016] Preferably, the co-emulsifier is selected from one or more of glycerol, n-butanol, diethylene glycol, diglycerol polypropylene glycol ether, alkyl ammonium salts, quaternary ammonium salts and derivatives thereof.
[0017] The pyrethroid anti-evaporation aqueous emulsion of the present invention may further contain other auxiliary agents, such as a defoaming agent and the like.
[0018] The role of emulsifiers: reduce the time and energy required to complete the dispersion process, stabilize the dispersed body, modify the surface properties of the material particles, and adjust the mobility of the material particles, that is, shorten the dispersion time, prevent flocculation, and prevent sedimentation. The role of thickeners: adjust the viscosity of the preparation and prevent sedimentation. The role of antifreeze agents: reduce the freezing point of the preparation, improve the antifreeze ability of the preparation, and can also dissolve ice crystals and prevent ice crystal growth. The role of crystal inhibitors: by strengthening their affinity with floating particles, improving interfacial adsorption, and reducing the surface energy of particles, it can effectively inhibit the crystal growth process. The role of co-emulsifiers: reduce the interfacial tension of each component in the mixed system, so that the two immiscible liquids can be better mixed to form a uniform emulsion, form a monomolecular layer on the surface of the droplets, prevent the droplets from aggregating with each other, and thus maintain the stability of the emulsion. The role of anti-evaporation agents: inhibit the evaporation of water during the droplet landing process in the air, reduce the loss of the drug solution, and better settle on the target organisms.
[0019] The present invention also provides a method for preparing the pyrethroid anti-evaporation aqueous emulsion, which comprises the following steps:
[0020] S1: Add the measured original drug into the reactor, add anti-evaporation agent A and heat it to 90°C to make it molten. Slowly cool the material under stirring. When the temperature drops to 50°C, add solvent 1 to prevent the mother liquor from solidifying and dissolve the fine crystals in the product. After the product is cooled to 40°C and completely dissolved, add a crystal inhibitor to the mother liquor, add solvent 2, and continue stirring for 10 minutes to stabilize it.
[0021] S2: Continue to add emulsifying dispersant 1 and emulsifying dispersant 2 into the reaction container and continue to stir evenly to obtain an oil phase.
[0022] S3: Add measured deionized water into a beaker, add co-emulsifier, antifreeze agent, thickener, anti-evaporation agent B, stir to form a uniform solution, and completely disperse the thickener by shearing to prepare the water phase.
[0023] S4: Add the oil phase while the water phase is being stirred. The initial mixed solution will become viscous. The viscosity will decrease after continued stirring. Use a high-speed shearing machine for homogenization to obtain a product with stable quality.
[0024] The invention pre-treats the original drug, the anti-evaporation agent and the crystal inhibitor, thereby effectively inhibiting the precipitation of the anti-evaporation agent while maintaining the effect of the anti-evaporation agent.
[0025] Compared with the prior art, the present invention has the following beneficial effects:
[0026] (1) The present invention adopts a new process to mix the anti-evaporation agent with the original drug, dissolve it in a solvent, and then inhibit the precipitation of the anti-evaporation agent by a crystal inhibitor, thereby solving the problem that the anti-evaporation agent is easy to crystallize. The anti-evaporation agent originally added by the barrel mixing process is directly added to the product formula, thereby improving the anti-evaporation ability while ensuring the stability of product quality and reducing the pollution of packaging materials to the environment.
[0027] (2) The present invention improves the anti-evaporation effect, inhibits the evaporation of droplet water, and increases the amount of drug droplets attached to the target biological surface, thereby ensuring the stability and performance of the final product. Compared with conventional formulations, the product of the present invention has stronger anti-evaporation properties, better spray effects when used outdoors, and better rapid knockdown activity. DETAILED DESCRIPTION
[0028] The technical scheme of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. The experimental methods used in the following embodiments are conventional methods unless otherwise specified; the reagents, materials, etc. used in the following embodiments, unless otherwise specified, can be obtained from commercial channels.
[0029] Unless otherwise specified, the percentages in the following examples are by mass percentages.
[0030] 1. Preparation of Examples and Comparative Examples
[0031] 1. Embodiment:
[0032] The 7% permethrin + cypermethrin aqueous emulsion of the example was prepared with reference to the raw material composition ratio in Table 1 below.
[0033] Table 1:
[0034]
[0035] The preparation method is as follows:
[0036] S1: Add the measured original drug into the reactor, add anti-evaporation agent A and heat it to 90°C to make it molten. Slowly cool the material under stirring. When the temperature drops to 50°C, add solvent 1 to prevent the mother liquor from solidifying and dissolve the fine crystals in the product. After the product is cooled to 40°C and completely dissolved, add a crystal inhibitor to the mother liquor, add solvent 2, and continue stirring for 10 minutes to stabilize it.
[0037] S2: Continue to add emulsifying dispersant 1 and emulsifying dispersant 2 into the reaction container and continue to stir evenly to obtain an oil phase.
[0038] S3: Add measured deionized water into a beaker, add co-emulsifier, antifreeze agent, thickener, anti-evaporation agent B, stir to form a uniform solution, and completely disperse the thickener by shearing to prepare the water phase.
[0039] S4: Add the oil phase while the water phase is being stirred. The initial mixed solution will become viscous. The viscosity will decrease after continued stirring. Use a high-speed shearing machine for homogenization to obtain a product with stable quality.
[0040] The above method was used to produce three batches continuously, which were recorded as 100901, 100902 and 100903, and their various technical indicators were tested.
[0041] 2. Comparative Example
[0042] The 7% permethrin+cypermethrin aqueous emulsion of Comparative Example 1 was prepared with reference to the raw material composition ratio in Table 2 below.
[0043] Table 2:
[0044]
[0045] The preparation method of Comparative Example 1 is as follows:
[0046] D1: Add the measured original drug into the reactor, add solvent 1 and solvent 2 to dissolve it, add emulsifier 1 and emulsifier 2 after dissolution, and stir for 15 minutes to obtain the oil phase.
[0047] D2: Add measured deionized water, antifreeze and thickener into a beaker, stir to form a uniform solution, and disperse the thickener completely by shearing to obtain the water phase.
[0048] D3: While the water phase is being stirred, the oil phase is added, stirred evenly, and then homogenized using a high-speed shearing machine to obtain a product with stable quality.
[0049] The method of Comparative Example 1 was adopted to continuously produce three batches, which were recorded as 101101, 101102 and 101103, and their various technical indicators were tested.
[0050] Comparative Example 2 was prepared by referring to the formulation and preparation method of the examples, except that no crystal inhibitor was added to the formulation of Comparative Example 1.
[0051] The method of Comparative Example 2 was adopted to continuously produce three batches, which were recorded as 101201, 101202 and 101203, and their various technical indicators were tested.
[0052] 2. Technical indicators test results
[0053] The technical indicators of the 7% permethrin + cypermethrin aqueous emulsion prepared in the above example and comparative example 1 are shown in Table 3:
[0054] Table 3
[0055]
[0056]
[0057] The initial test results of various indicators of each batch of the embodiment and comparative example 1 products are shown in the following table 4:
[0058] Table 4:
[0059]
[0060] It can be seen from the above technical index data that the formula and preparation method of Example 1 and Comparative Example 1 can prepare qualified aqueous emulsions.
[0061] The initial test results of various indicators of the comparative example 2 products of each batch are shown in the following table 5:
[0062] Table 5:
[0063]
[0064] The above data show that the low-temperature stability of the product of Comparative Example 2 is unqualified. The reason is that the product does not add a crystallization inhibitor. During the low-temperature stability test, the solubility of the anti-evaporation agent basic acrylic resin in the solvent is reduced, and it slowly precipitates and produces precipitation. In addition, after the product of Comparative Example 2 is stored at room temperature for more than three months, precipitation will gradually occur. After testing, the precipitation produced in the low-temperature stability test and the room-temperature storage test is basic acrylic resin.
[0065] 3. Anti-evaporation test
[0066] Test method: Use a microinjection needle to accurately push out 0.2μL of sample, suspend it at the tip of the needle, and record the evaporation time of the liquid under the same temperature, humidity and wind speed conditions.
[0067] The test results are as follows:
[0068]
[0069] It can be seen from the above data that the anti-evaporation performance of the samples in the embodiment of the present invention and the comparative example 2 is significantly better than that of the sample in the comparative example 1.
[0070] 4. Biological Experiments
[0071] Experiment 1:
[0072] Indoor ultra-low volume spraying, to control mosquitoes and flies
[0073] Residual spraying test, according to GBT 13917.10-2009 Indoor efficacy test and evaluation of public health insecticides for pesticide registration Part 10: Simulated field, the experimental sample was diluted 200 times to make a spray solution, and sprayed with a hand pressure sprayer. The knockdown rate of mosquitoes and flies was recorded as 1 hour, and the mortality rate was recorded as 24 hours;
[0074] After 1 hour, the knocked-down test insects were collected into clean insect cages and the standard feeding was resumed. The test insects that were not knocked down were not collected and counted in the number of live insects in 24 hours. The number of dead test insects was checked after 24 hours.
[0075] The recorded data is as follows:
[0076]
[0077]
[0078] Experiment 2
[0079] Outdoor ultra-low volume spraying, to control mosquitoes and flies
[0080] In the residual spraying test, according to GBT 27781-2011 on-site efficacy determination and evaluation of sanitary insecticides, the experimental samples were diluted 200 times to make spray solution, and sprayed using a hand pressure sprayer. The 24-hour mortality of mosquitoes and flies was recorded;
[0081] The recorded data is as follows:
[0082]
[0083] The above results show that the formulations of the embodiments of the present invention have excellent mosquito and fly control effects. When sprayed indoors at ultra-low volume, the control effects of the three reached Class A, and the effect of Example 1 was slightly better than that of Comparative Examples 1 and 2. However, due to the use of anti-evaporation agents in Example 1 and Comparative Example 2, the outdoor ultra-low volume spray effect was significantly higher than that of Comparative Example 1.
[0084] 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 pyrethroid anti-evaporation aqueous emulsion, characterized in that: Calculated by mass percentage, it contains active ingredient pyrethroid 0.1%-25%, organic solvent 5%-30%, crystal inhibitor 2%-8%, anti-evaporation agent 2%-10%, emulsifying dispersant 5%-15%, thickener 0.1%-3%, co-emulsifier 3%-8%, antifreeze 3%-8%, and the rest is deionized water.
2. The pyrethroid anti-evaporation aqueous emulsion according to claim 1, characterized in that: The active ingredients include one or two of permethrin, cis-cypermethrin, S-bioallethrin, high-efficiency cyfluthrin, high-efficiency cypermethrin, cyfluthrin, tetrathrin, tetrathrin, bifenthrin, high-efficiency cyfluthrin, and cypermethrin.
3. The pyrethroid anti-evaporation aqueous emulsion according to claim 1, characterized in that: The emulsifying dispersant includes at least one of fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether, triphenyl phenol polyoxyethylene ether, triphenyl phenol polyoxyethylene polyoxypropylene ether, castor oil polyoxyethylene ether, fatty acid polyoxyethylene ether, sorbitan fatty acid ester, sorbitan fatty acid ester polyoxyethylene ether, alkylphenol formaldehyde condensate polyoxyethylene ether, calcium dodecylbenzene sulfonate 500#, arylphenol polyoxyethylene ether phosphate and salts thereof, nonylphenol polyoxyethylene ether phosphate and salts thereof, fatty alcohol polyoxyethylene ether phosphate and salts thereof, and arylphenol polyoxyethylene ether sulfate.
4. The pyrethroid anti-evaporation aqueous emulsion according to claim 1, characterized in that: The crystal inhibitor comprises at least one of nonionic hydroxy polyethylene oxide block polyether, butanol block polyether phosphate, sodium lauryl alcohol polyether sulfate, novel grafted comb-shaped carboxylic acid phosphate, and novel comb-shaped polyoxyethylene polyoxypropylene block polyether.
5. The pyrethroid anti-evaporation aqueous emulsion according to claim 1, characterized in that: The solvent includes at least one of dimethyl carbonate, benzyl acetate, ethylene glycol tert-butyl ether, N-methylpyrrolidone, N,N-dimethylformamide, tributyl citrate, piperonyl ether, solvent oil 150#, propylene glycol ether, isopentyl citrate, ethyl acetate, n-butyl acetate, and dimethyl phthalate.
6. The pyrethroid anti-evaporation aqueous emulsion according to claim 1, characterized in that: The anti-evaporation agent includes at least one of basic acrylic resin, sodium tripolyphosphate, sodium hexametaphosphate, disodium hydrogen phosphate, stearic acid, isooctyl alcohol, palmitic acid, and capric acid.
7. The pyrethroid anti-evaporation aqueous emulsion according to claim 1, characterized in that: The antifreeze agent is selected from at least one of ethylene glycol, propylene glycol, polyethylene glycol and isopropanol.
8. The pyrethroid anti-evaporation aqueous emulsion according to claim 1, characterized in that: The thickener is selected from at least one of xanthan gum, cellulose and its derivatives, magnesium aluminum silicate, bentonite, kaolin, diatomaceous earth and attapulgite.
9. The pyrethroid anti-evaporation aqueous emulsion according to claim 1, characterized in that: The co-emulsifier is selected from one or more of glycerol, n-butanol, diethylene glycol, diglycerol polypropylene glycol ether, alkyl ammonium salt, quaternary ammonium salt and derivatives thereof.
10. The method for preparing the pyrethroid anti-evaporation aqueous emulsion according to claim 1, characterized in that: The method comprises the following steps: S1: Add the measured pyrethroid technical into the reactor, add anti-evaporation agent A and heat to 90°C to make it melt. Slowly cool the material under stirring. When the temperature drops to 50°C, add solvent 1 to prevent the mother liquor from solidifying and dissolve the fine crystals in the product. After the product is cooled to 40°C and completely dissolved, add a crystal inhibitor to the mother liquor, add solvent 2, and continue stirring for 10 minutes to stabilize it. S2: continue to add emulsifying dispersant 1 and emulsifying dispersant 2 into the reaction container, continue to stir evenly, and obtain an oil phase; S3: Add measured deionized water into a beaker, add a co-emulsifier, an antifreeze agent, a thickener, and an anti-evaporation agent B, stir to form a uniform solution, and completely disperse the thickener by shearing to obtain a water phase; S4: Add the oil phase while the water phase is being stirred. The initial mixed solution will become viscous. The viscosity will decrease after continued stirring. Use a high-speed shearing machine for homogenization to obtain a product with stable quality.