Special auxiliary agent adaptive to propoxur and pyrethroid compound missible oil

Abstract

The invention discloses a special auxiliary agent adaptive to propoxur and pyrethroid compound missible oil, which adopts a ternary emulsification system, is designed aiming at polarity difference of propoxur and pyrethroid, solves the layering / devitrification problem of a high-concentration compound missible oil preparation, realizes quick-acting and long-acting pesticide effect balance, realizes low aromatic hydrocarbon residue on the premise of guaranteeing the pesticide effect, and has the advantages of simple preparation process and low cost. The problems of poor stability and safety are solved, and the technical trend of green pesticides is met.

Description

Technical Field

[0001] This invention belongs to the field of sanitary insecticide technology, specifically relating to a special adjuvant adapted to compound emulsifiable concentrates of propoxur and pyrethroids, and the corresponding emulsifiable concentrate formulations made therefrom. The emulsifiable concentrate formulations are particularly suitable for the control of sanitary pests such as mosquitoes, flies, and cockroaches in public places such as homes, shopping malls, and hospitals. Background Technology

[0002] The rampant infestation of sanitary pests not only affects the comfort of living environments but also easily spreads infectious diseases such as dengue fever and dysentery. Therefore, highly effective, safe, and long-lasting sanitary insecticides have always been a key focus of industry research and development. Carbamate insecticides such as propoxur possess strong stomach poison activity, showing significant efficacy against chewing pests like cockroaches, and exhibiting low toxicity to humans and animals. Pyrethroid pesticides such as cypermethrin, deltamethrin, and lambda-cyhalothrin generally possess excellent contact and fumigation activity, showing outstanding rapid effectiveness against flying sanitary pests such as mosquitoes and flies. Combining propoxur with pyrethroid pesticides can achieve a synergistic effect of "stomach poison + contact + fumigation," significantly improving the control effect against complex sanitary pest populations. Therefore, the combination system of propoxur and pyrethroid pesticides has become one of the mainstream research directions for sanitary insecticides.

[0003] The adjuvant system is the core of the performance of compound insecticide formulations, directly determining the dispersion stability of the active ingredient, the efficacy, and the safety of use. Currently, the adjuvant system for compounding carbendazim with pyrethroid insecticides mostly adopts the traditional combination of conventional anionic / nonionic emulsifiers + aromatic solvents + basic functional adjuvants, which presents the following technical problems: 1. Insufficient compatibility of emulsion systems: Reprodione is a moderately polar compound (logP≈2.8), while pyrethroid pesticides are mostly low-polar compounds (logP≈5.0-7.0), showing a significant difference in polarity. Current technologies mostly employ a binary emulsion system of linear dodecylbenzene sulfonate and ordinary castor oil polyoxyethylene ether. This system can only meet the basic dispersion requirements at conventional concentrations. When the total concentration of the active ingredient increases to 6% or higher, it is prone to crystallization at low temperatures (-5℃ and below) and demulsification after 3 months of storage at room temperature, resulting in uneven formulation efficacy and failing to meet the storage and use requirements of cold-climate regions in the north. Simultaneously, the binding force between conventional emulsifiers and the active ingredient is weak, and the active ingredient is easily lost from the target surface after spraying, reducing the actual control efficacy.

[0004] 2. Imbalance between the environmental friendliness and compatibility of solvent systems: Existing formulations generally use alcohol ether solvents and industrial mineral oils as the main solvents. Alcohol ether solvents have high water solubility, but they have significant chronic toxicity to aquatic organisms, are difficult to degrade and easily bioaccumulate, and can also be adsorbed on indoor object surfaces and slowly released, reacting with ozone to generate irritating aldehydes, causing secondary pollution. Industrial mineral oils have poor compatibility with ester co-solvents, which can easily lead to turbidity in the formulations, and cannot meet the different dissolution requirements of propoxur and pyrethroid pesticides. Some formulations may have local enrichment of active ingredients due to insufficient solvent compatibility, which may lead to acute toxicity risks to non-target organisms.

[0005] 3. Lack of synergistic effect of functional adjuvants: In existing technologies, penetration adjuvants (such as lauryl acetone) and film-forming adjuvants (such as polyvinyl alcohol) are mostly added independently, without forming a synergistic effect. Although adding lauryl acetone alone can increase the penetration rate of the active ingredient into the insect body wall and achieve rapid insecticidal effect, it cannot prolong the residence time of the active ingredient on the target surface. The efficacy drops to below 60% after 7 days after application. Relying solely on polyvinyl alcohol for film formation will lead to obstructed penetration of the active ingredient, insufficient rapid effect, and difficulty in quickly suppressing insect populations. At the same time, existing systems generally do not add targeted anti-decomposition adjuvants. Pyrethroid pesticides can decompose at a rate of over 18% after 15 days under natural light, and propoxur will also show slight degradation under high temperature conditions, significantly shortening the effective period of the formulation.

[0006] 4. Limited safety and applicability: Components such as mineral oil and linear alkylbenzene sulfonates in traditional adjuvant systems pose certain risks of adhesion and corrosion. In addition, some adjuvants have poor biodegradability and are prone to leaving residues in the environment. This does not conform to the current industry development trend of "low residue and green environmental protection" for sanitary pesticides, nor can it meet the usage standards of sensitive places such as hospitals and kindergartens.

[0007] Although the industry has made some optimizations to adjuvant systems for single active ingredients, such as using ester cosolvents to improve the solubility of pyrethroids and using polycarboxylate emulsifiers to improve the dispersibility of carbamates, there is still a technological gap in adjuvant systems that simultaneously address the specific compound system of propoxur and pyrethroid pesticides, balancing "high concentration stability, rapid and sustained effect, environmental safety, and resistance to active ingredient decomposition." No dedicated adjuvant has yet emerged that can simultaneously solve multiple technical problems. Therefore, developing a dedicated adjuvant adapted to the characteristics of propoxur and pyrethroid pesticide emulsifiable concentrates is key to overcoming the performance bottlenecks of existing sanitary insecticide formulations. Summary of the Invention

[0008] To achieve the above objectives, the technical content disclosed in this invention is as follows: This invention provides a special adjuvant suitable for compound emulsifiable concentrates of propoxur and pyrethroids, made from the following raw materials in weight percentages: branched dodecylbenzenesulfonate calcium 1-10%, castor oil polyoxyethylene ether EL-40 1-10%, alkylphenol polyoxyethylene ether phosphate 0.1-5%, methylated vegetable oil 1-10%, diisopropyl adipate 5-25%, isopropyl myristate 1-15%, lauryl azone 0.1-5%, PVA1788 0.5-5%, xanthan gum 0.05-5%, polyquaternium-39 0.01-5%, UV-327 0.01-5%, and dearomatic solvent oil S-20 to make up to 100%.

[0009] Preferably, a special adjuvant adapted to compound emulsifiable concentrates of propoxur and pyrethroids is made from the following raw materials in weight percentages: 1-5% branched dodecylbenzenesulfonate, 2-8% castor oil polyoxyethylene ether EL-40, 0.1-1% alkylphenol polyoxyethylene ether phosphate, 3-8% methylated vegetable oil, 5-15% diisopropyl adipate, 5-10% isopropyl myristate, 0.5-1.5% lauryl azone, 1-3% PVA1788, 0.05-1% xanthan gum, 0.1-1.5% polyquaternium-39, 0.01-1.5% UV-327, and dearomatic solvent oil S-20 to make up to 100%.

[0010] Preferably, the weight ratio of the branched dodecylbenzenesulfonate calcium, castor oil polyoxyethylene ether EL-40, and alkylphenol polyoxyethylene ether phosphate is 4:6:1.

[0011] Preferably, the pyrethroid pesticide is selected from one of the following: permethrin, cypermethrin, cis-cypermethrin, high-efficiency cypermethrin, deltamethrin, bifenthrin, high-efficiency cyhalothrin, high-efficiency cyhalothrin, methamidophos, dextromethorphan, dextro-trans-propargyl, propargyl, dextromethorphan, tetrafluorobenzenefenpyrethrin, chlorfluazuron, chlorpyrifos, tetrafluorobenzenefenpyrethrin, tetrafluorobenzenefenpyrethrin, ES-bioallethrin, S-bioallethrin, methoxybenzenefenpyrethrin, cypermethrin, and tetrafluorobenzenefenpyrethrin.

[0012] Preferably, the amount of the additive added is 5-90% by mass percentage, more preferably 30-60% based on the total emulsifiable oil content.

[0013] Furthermore, the present invention also provides a compound emulsifiable concentrate of propoxur and pyrethroids prepared from the above-mentioned emulsifiable concentrate adjuvants, and its application in controlling sanitary pests. The sanitary pests are cockroaches, fleas, cockroaches, ants, bedbugs, mosquitoes, and flies; The preferred species are light-colored Culex mosquitoes, houseflies, and cockroaches.

[0014] Compared with existing technologies, the above technical solution achieves the following significant advantages: 1. This invention employs a ternary emulsification system designed to address the polarity differences of "cypermethrin-reducing compounds," thus solving the layering / crystallization problem in high-concentration compound formulations. Existing technologies do not have emulsification combinations specifically designed for this active ingredient.

[0015] 2. The combination of lauryl azone, PVA, and polyquaternium salt used in this invention achieves a balance between rapid and long-lasting efficacy, far exceeding the effect of a single penetration / film-forming aid in the prior art.

[0016] 3. The combination of the environmentally friendly solvent dearomatic solvent and plant-derived methyl ester oil in this invention achieves low aromatic residue while ensuring efficacy, solving the problems of poor stability and safety, and conforming to the technical trend of green pesticides. Detailed Implementation

[0017] The present invention will be described below with reference to specific embodiments. It should be noted that the following embodiments are examples of the present invention and are used only to illustrate the invention, not to limit it. Other combinations and various modifications within the scope of the present invention can be made without departing from its spirit or scope. The component contents of each embodiment and comparative example are all percentage contents (%).

[0018] The parameters of some raw materials used in the examples and comparative examples are as follows: The branched-chain dodecylbenzenesulfonate calcium was purchased from Handan Xindiya Chemical Co., Ltd., with a content of 70% and is a liquid. Examples 1-6

[0019] Examples 7-12

[0020] Comparative Examples 1-3

[0021] Application Example 1 Emulsion stability: Tested according to GB / T 1603-2001. Dilute the formulation 500 times and observe the layering after 24 hours. No layering is acceptable.

[0022] Permeation performance: The filter paper permeation method was used. 50mm diameter, 0.1mm thick qualitative medium-speed filter paper was selected, and 0.05% carmine was added to the spray solution. 0.2mL of the test spray solution was taken with a 1mL syringe and added vertically dropwise onto 30 stacked layers of filter paper. The diameter and depth of the wetting spots were observed and measured.

[0023] Insecticidal effect: The drug film method was used, in which different concentrations of extract were prepared into drug films. Thirty houseflies (half male and half female) that had emerged 15-20 days after mating were placed in a dried drug film bottle, the bottle opening was sealed with gauze, and after 2 hours of contact, the houseflies in each treatment were transferred to an insect rearing cage. After 24 hours, the mortality rate was recorded. Each group was repeated three times, and a mortality rate of ≥95% was considered excellent.

[0024] Mortality rate (%) = Number of dead test insects / Total number of test insects × 100 Corrected mortality rate (%) = (treatment group mortality rate - control group mortality rate) / (1 - control group mortality rate) × 100 Storage stability: Store in a constant temperature chamber at 54℃ for 14 days, and measure the change rate of active ingredient content before and after storage. A change rate of ≤5% is considered acceptable.

[0025] The test results are shown in Table 1: Examples 1-3 and Comparative Examples 1 and 3 all passed the tests, while only Comparative Example 2 failed the emulsification test. The main difference between Examples 1 and Comparative Example 2 lies in the emulsifier system: Examples 1 used a ternary composite system of "branched dodecylbenzenesulfonate calcium + castor oil polyoxyethylene ether EL-40 + alkylphenol polyoxyethylene ether phosphate". This system, through the synergistic effect of anionic and nonionic emulsifiers, can simultaneously adapt to the different polarity requirements of propoxur (medium polarity) and tetrafluoromethrin (low polarity), forming a stable oil-water interface film with no stratification within 24 hours; while Comparative Example 2 used the traditional single anionic emulsifier sodium dodecyl sulfate, whose lipophilic groups have weak binding force with the nonpolar tetrafluoromethrin, failing to maintain system stability, resulting in stratification after dilution, directly affecting the subsequent efficacy.

[0026] Example 3 exhibited the best penetration performance (penetration depth 19.8 mm, wetting diameter 9.8 mm) because its lauryl azone content was increased to 1.5 parts by weight and its methylated vegetable oil content was increased to 7.0 parts by weight. Lauryl azone can destroy the waxy layer of the housefly body wall, while methylated vegetable oil enhances the solubility of the active ingredient. The two work synergistically to make the penetration depth close to the level of Example 1 and the wetting diameter even better. Comparative Example 1 had the worst two indicators (penetration depth 14.3 mm, wetting diameter 6.2 mm) because it completely lacked lauryl azone, so the formulation could not quickly break through the housefly body wall barrier and had poor surface spreadability. The active ingredient remained on the target surface and was difficult to enter the body to exert its effect. Comparative Examples 2 and 3 had penetration depths close to the levels of the examples, but Comparative Example 2 had a slightly lower wetting diameter due to uneven emulsification. Comparative Example 3 did not add a stabilizer, which did not affect the immediate penetration performance, but the long-term stability was reduced.

[0027] The corrected mortality rates of Examples 1-3 were all ≥95.40%, meeting the "excellent" standard. Among them, Example 2 ranked first with a mortality rate of 98.85%. The mortality rates of Comparative Examples 1-3 were all lower than 87.36% and did not reach the excellent standard. By increasing the dosages of alkylphenol polyoxyethylene ether phosphate and polyquaternium-39, Example 2 can maintain the stability of the active ingredient in the simulated humid environment, avoid the attenuation of drug efficacy caused by the influence of moisture. At the same time, the dosage of the film-forming agent PVA1788 was increased to 1.8 parts by mass, prolonging the residence time of the active ingredient on the target surface and achieving the balance between quick effect and long-lasting effect. In Comparative Example 1, due to the absence of a penetration enhancer, the active ingredient could not enter the housefly body efficiently, and the mortality rate was only 80.46%. In Comparative Example 2, due to unqualified emulsification, the active ingredient was unevenly dispersed, and the concentration in some areas was insufficient, resulting in a mortality rate of 86.2%. In Comparative Example 3, due to the absence of UV-327 and polyquaternium-39, the active ingredient had been slightly degraded before the test, resulting in a mortality rate of 87.36%. Although it was higher than the previous two, it still did not meet the standard.

[0028] Only Comparative Example 3 showed unqualified storage stability, and the rest of the formulations were qualified. The key influencing factor was the stability system: UV-327 and polyquaternium-39 were added to Examples 1-3. UV-327 can absorb ultraviolet light and inhibit the photodegradation of pyrethroid pesticides, while polyquaternium-39 prevents the hydrolysis reaction of propoxur by chelating metal ions. After accelerating storage at 54°C for 14 days, the degradation rates of the active ingredients were all controlled within the qualified range. In Comparative Example 3, the above two stabilizers were not used, and the photodegradation of the active ingredient accelerated at high temperature, resulting in a decrease in the total amount of the active ingredient and being judged as unqualified for storage, directly shortening the shelf life of the preparation.

[0029] Table 1 Test of Emulsion Index

[0030] Application Example 2 Control Effects of the Mixture of Propoxur and Pyrethroid Pesticides on Culex pipiens pallens and Cockroaches Culex pipiens pallens (3-5-day-old adults, half male and half female, 30 per treatment); Blattella germanica (7-10-day-old adults, 20-30 mg, 40 per treatment), all were laboratory sensitive strains.

[0031] Experimental agents: Examples 1, 4, 5, 6; Control agents: 10% beta-cyfluthrin wettable powder (commercially available), 5% dimefluthrin·permethrin aqueous emulsion (commercially available). For the spray test, the agents were all diluted 100 times with water. The blank control (CK) was only treated with diluting 100 times with de-aromatic solvent oil S-200 and had no active ingredient.

[0032] Experimental Methods: Following the guidelines for indoor bioassay of pesticides, Part 1: Contact Activity Test, the activity of *Culex pipiens pallens* was determined using the droplet method according to NY / T1154.1-2006. Based on the survey data, the corrected mortality rate for each treatment was calculated as a percentage (%). Calculations were performed according to formulas (1) and (2), and all results were rounded to two decimal places. ....................................................(1) In the formula: P -- Mortality rate; K-- indicates the number of dead insects; N-- represents the total number of insects treated.

[0033] ..............................................(2) In the formula: P2 -- Corrected mortality rate; P t --Managing mortality rates; P0 -- Mortality rate in the blank control group.

[0034] If the control mortality rate is <5%, no correction is needed; if the control mortality rate is between 5% and 20%, correction should be made according to formula (2); if the control mortality rate is >20%, the experiment needs to be repeated.

[0035] Examples 1, 4, 5, and 6 of this invention showed significantly better performance against cockroaches and Culex pipiens pallens than 10% high-efficiency cyhalothrin wettable powder and 5% tetrafluoroethylene. The control effect of permethrin emulsion was evaluated, with Example 1 showing the best overall control efficacy (97.65% mortality rate for cockroaches and 90.83% mortality rate for Culex pipiens pallens), demonstrating good potential for practical application.

[0036] Table 2. Control efficacy of a mixture of propoxur and pyrethroid pesticides against Culex pipiens pallens and cockroaches.

[0037] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0038] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. Furthermore, various different embodiments of the present invention can also be arbitrarily combined, as long as they do not violate the spirit of the present invention, and they should also be regarded as the content disclosed by the present invention.

Claims

1. A special adjuvant adapted to compound emulsifiable concentrates of propoxur and pyrethroids, characterized in that, Made from the following raw materials in weight percentage: branched dodecylbenzenesulfonate calcium 1-10%, castor oil polyoxyethylene ether EL-40 1-10%, alkylphenol polyoxyethylene ether phosphate 0.1-5%, methylated vegetable oil 1-10%, diisopropyl adipate 5-25%, isopropyl myristate 1-15%, lauryl azone 0.1-5%, PVA1788 0.5-5%, xanthan gum 0.05-5%, polyquaternium-39 0.01-5%, UV-327 0.01-5%, and dearomatic solvent oil S-20 to 100%.

2. The special adjuvant adapted to compound emulsifiable concentrates of propoxur and pyrethroids according to claim 1, characterized in that, Made from the following raw materials in weight percentage: branched dodecylbenzenesulfonate calcium 1-5%, castor oil polyoxyethylene ether EL-40 2-8%, alkylphenol polyoxyethylene ether phosphate 0.1-1%, methylated vegetable oil 3-8%, diisopropyl adipate 5-15%, isopropyl myristate 5-10%, lauryl azone 0.5-1.5%, PVA1788 1-3%, xanthan gum 0.05-1%, polyquaternium-39 0.1-1.5%, UV-327 0.01-1.5%, and dearomatic solvent oil S-20 to 100%.

3. The special adjuvant adapted to compound emulsifiable concentrates of propoxur and pyrethroids according to claim 2, characterized in that, The weight ratio of the branched dodecylbenzenesulfonate calcium, castor oil polyoxyethylene ether EL-40, and alkylphenol polyoxyethylene ether phosphate is 4:6:

1.

4. A special adjuvant adapted to compound emulsifiable concentrates of propoxur and pyrethroids according to any one of claims 1-3, characterized in that, The pyrethroid pesticides are selected from one of the following: permethrin, cypermethrin, cis-cypermethrin, high-efficiency cypermethrin, deltamethrin, bifenthrin, high-efficiency cyhalothrin, high-efficiency cyhalothrin, methamidophos, dextromethorphan, dextro-trans-propargyl, propargyl, dextromethorphan, tetrafluorobenzyl, chlorfluazuron, chlorpyrifos, tetrafluorobenzyl, tetrafluorobenzyl, ES-bioallethrin, S-bioallethrin, methoxybenzylfluazuron, cypermethrin, and tetrafluorobenzylfluazuron.

5. A special adjuvant adapted to compound emulsifiable concentrates of propoxur and pyrethroids according to any one of claims 1-3, characterized in that, The amount of this additive added is 5-90% by mass, based on the total emulsifiable concentrate.

6. The emulsifiable concentrate adjuvant adapted for compounding propoxur and pyrethroids according to claim 5, characterized in that, The amount of this additive added is 30-60% by mass, based on the total emulsifiable concentrate.

7. The use of a compound emulsifiable concentrate of propoxur and pyrethroids, made from the emulsifiable concentrate adjuvants according to any one of claims 1-6, for the control of sanitary pests.

8. The use according to claim 7, characterized in that, The sanitary pests mentioned are houseflies, cockroaches, and mosquitoes.

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