Preparation method of long-acting weeding combined microemulsion

Abstract

The invention relates to the technical field of herbicides, and particularly discloses a preparation method of a long-acting weeding combined microemulsion, the long-acting weeding combined microemulsion is composed of three main weeding components of quizalofop-p-ethyl oil phase, fomesafen sodium salt water phase and bentazone sodium salt water phase, and additives such as an emulsifier, has a wide weeding range, and can be applied to the field of weeding. The microemulsion can kill most weeds and has good stability at different temperatures, crystals are not easy to separate out, and the content of effective components is not easy to decrease. By using the long-acting weeding combined microemulsion, the phenomena of random use, blind use, misuse and abuse of herbicides by a user at present can be well improved.

Description

Technical Field

[0001] The invention relates to the technical field of herbicides, and in particular to a method for preparing a long-acting herbicide combination microemulsion. Background Art

[0002] Soybean is an important food crop and oil crop. The demand for soybean from downstream industries such as soybean oil, soybean products, and livestock feed is also increasing year by year. Therefore, it is particularly important to increase the per-acre yield of soybean. Among them, the control of weeds in soybean fields has always been an important factor that plagues the per-acre yield of soybean.

[0003] At present, the use of herbicides in soybean fields is arbitrary and blind, due to the lack of knowledge of the relationship between single pesticide varieties and the scientific basis for compounding of some pesticide sales personnel and pesticide users, resulting in poor weed control effects, crop damage and reduced production. In addition, some farmers are accustomed to using a single pesticide variety, which has caused changes in the weed phase of soybean fields and weed resistance has become increasingly obvious. Therefore, it is urgent to use a diversified herbicide compound for weed control. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing a long-acting herbicide combination microemulsion to solve the problem of poor weed control effect caused by random compounding of herbicides.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] A long-acting herbicide combination microemulsion mainly comprises, by weight, 18 to 20 parts of quizalofop-p-ethyl oil phase, 15 to 20 parts of emulsifier, 15 to 18 parts of fomesafen sodium salt water phase, 40 to 45 parts of bentazon sodium salt water phase, and 5 to 12 parts of deionized water.

[0007] As a limitation of the present invention, the dosage of each component in the Quizalofop-Ph-ethyl oil phase is: 15 to 20 parts of Quizalofop-Ph-ethyl technical, 50 to 60 parts of xylene, and 25 to 30 parts of dimethyldecylamide.

[0008] As a limitation of the present invention, the amounts of the components in the sodium fomesafen salt phase are as follows, by weight: 50-70 parts of fomesafen technical, 5-7 parts of sodium hydroxide, and 30-40 parts of deionized water.

[0009] As a limitation of the present invention, the dosage of each component in the sodium bentazone salt water phase is: 50-70 parts of bentazone original drug, 6-9 parts of sodium hydroxide, and 25-35 parts of deionized water.

[0010] As a limitation of the present invention, the emulsifier used is a combination of one or more of AEO-5 emulsifier, AEO-7 emulsifier and OP-9 emulsifier.

[0011] A preparation method of a long-acting herbicidal combined microemulsion, specifically as follows:

[0012] First, mix the emulsifier with the quizalofop-p-ethyl oil phase evenly to form a mixed solution. Then, successively add the fomesafen sodium aqueous phase and the bentazone sodium aqueous phase to the mixed solution of the quizalofop-p-ethyl oil phase and the emulsifier, stir evenly, add deionized water, and adjust the pH to 6.5 - 7.0 with glacial acetic acid and sodium hydroxide aqueous solution to obtain the long-acting herbicidal combined microemulsion.

[0013] As a limitation of the present invention, the preparation method of the fomesafen sodium aqueous phase or the bentazone sodium aqueous phase is as follows:

[0014] Mix sodium hydroxide and deionized water, stir evenly to obtain a sodium hydroxide solution. Add the fomesafen technical or bentazone sodium technical to the sodium hydroxide solution, adjust the pH to 7.0 - 10.0 with glacial acetic acid and sodium hydroxide solution and keep stirring to make the system react fully until the mixed solution is clear and transparent, then stop stirring to obtain the fomesafen sodium aqueous phase or the bentazone sodium aqueous phase.

[0015] As a limitation of the present invention, by mass fraction, when preparing the long-acting herbicidal combined microemulsion, 0.4 - 0.6% of methylated vegetable oil, 0.2 - 0.3% of amino-oligosaccharide aqueous agent, and 4 - 6% of ethylene glycol can also be added based on the total mass of the long-acting herbicidal combined microemulsion.

[0016] As a limitation of the present invention, the preparation method of the methylated vegetable oil is as follows:

[0017] Mix peanut oil, methanol and sodium hydroxide solution, add zeolite to prevent bumping, reflux and heat in a water bath at 70 - 90 °C for 0.5 - 1.5 h. After heating is completed, drop in hydrochloric acid solution to adjust the pH, stir evenly, filter by suction to obtain higher fatty acids. Add methanol and concentrated sulfuric acid to the obtained higher fatty acids, stir evenly, reflux and heat in a water bath at 70 - 90 °C for 0.5 - 1.5 h, then stop heating, cool, let it stand for layering, wash with deionized water, and distill under reduced pressure to obtain methylated peanut oil. According to the same preparation method, mix corn oil, methanol and sodium hydroxide solution to prepare methylated corn oil;

[0018] Mix the methylated peanut oil and the methylated corn oil, add OP-7 emulsifier, PEG-400 emulsifier and ZR-5 emulsifier, stir evenly to obtain the synergist methylated vegetable oil.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] The present invention combines and compoundes quizalofop - p - ethyl, fomesafen, and bentazone to prepare a microemulsion. The killing scopes and action mechanisms of the three herbicides on weeds are different. After compounding, the killing scopes of weeds are complementary, and most weeds can be killed after use.

[0021] The present invention selects xylene and dimethyldecanamide as compounding solvents, avoiding the situation that when a single oily solvent is used as a carrier, it is difficult for the preparation to transform from an oil - in - water system to a water - in - oil system, and also avoiding the situation that when a single polar solvent is used as a carrier, it cannot encapsulate the technical material of the pesticide, and crystal precipitation occurs during use, affecting the use of the product.

[0022] In the present invention, the compounding of two emulsifiers can effectively improve the stability of the microemulsion and prevent the precipitation of the active ingredients. In addition, the selected AEO - 5 emulsifier has a significant penetration effect, helping the droplets to quickly penetrate the surface layer of the weeds, penetrate into the stems and leaves for conduction, promoting the absorption of the liquid medicine, and accelerating the death of the weeds. The selected OP - 9 emulsifier will form a colloid with water in a certain proportion and spread on the leaf surface layer, extending the effective duration.

[0023] The present invention adds methylated vegetable oil, which can significantly reduce the surface tension and contact angle of the microemulsion liquid medicine, is beneficial to increasing the deposition amount of the microemulsion liquid medicine on the surface of plant leaves, thereby enhancing the weeding effect and improving the control effect on weeds. It adds an amino - oligosaccharide aqueous solution, which can enhance the immune induction ability of crops, strengthen the defense ability of crops against harsh environments such as cold damage and high temperature, and relieve the phytotoxicity symptoms such as burning - type lesions and heart - leaf deformities caused by herbicides in crops. It adds ethylene glycol, enhancing the stability of the microemulsion at low temperatures. Specific Embodiments

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0025] The technical material of fomesafen (purity: 95%) is provided by Jiangsu Changqing Agro - Chemical Co., Ltd., the technical material of bentazone (purity: 97%) is provided by Jiangsu Institute of Hormones Co., Ltd., the technical material of quizalofop - p - ethyl (purity: 97%) is provided by Shandong Kingbo Agro - Chemical Technology Co., Ltd., peanut oil and corn oil are both commercially available, OP - 7 emulsifier, PEG - 400 emulsifier, ZR - 5 emulsifier, OP - 9 emulsifier, AEO - 5 emulsifier, AEO - 7 emulsifier, and 1104 emulsifier are provided by Beijing Guangyuan, and the amino - oligosaccharide aqueous solution (2%) is provided by Dalian Kaifei.

[0026] Example 1: A preparation method of a long-acting herbicidal combined microemulsion, specifically as follows:

[0027] Step 1: Prepare the sodium salt aqueous phase of fomesafen

[0028] By mass, 6.0 parts of sodium hydroxide and 35.0 parts of deionized water are mixed and stirred evenly to obtain a sodium hydroxide solution. 60 parts of fomesafen technical are added to the sodium hydroxide solution, and the pH is adjusted to 8.0 with glacial acetic acid and the sodium hydroxide solution while stirring continuously to make the system react fully until the mixed solution is clear and transparent. Then stop stirring to obtain the sodium salt aqueous phase of fomesafen.

[0029] Step 2: Prepare the sodium salt aqueous phase of bentazone

[0030] By mass, 7.5 parts of sodium hydroxide and 30.0 parts of deionized water are mixed and stirred evenly to obtain a sodium hydroxide solution. 60 parts of bentazone technical are added to the sodium hydroxide solution, and the pH is adjusted to 8.0 with glacial acetic acid and the sodium hydroxide solution while stirring continuously to make the system react fully until the mixed solution is clear and transparent. Then stop stirring to obtain the sodium salt aqueous phase of bentazone.

[0031] Step 3: Prepare the oil phase of quizalofop-p-ethyl

[0032] By mass, 55 parts of xylene and 28 parts of dimethyl decanamide are mixed and stirred evenly to obtain a xylene mixed solvent. 17 parts of quizalofop-p-ethyl technical are added to 83 parts of the xylene mixed solvent and stirred evenly to obtain the oil phase of quizalofop-p-ethyl.

[0033] Step 4: Prepare the long-acting herbicidal combined microemulsion

[0034] By mass, a mixture of 17 parts of AEO-7 emulsifier and OP-9 emulsifier (mass ratio 1:1) is first mixed evenly with 19 parts of the oil phase of quizalofop-p-ethyl to form a mixed solution. Then 16 parts of the sodium salt aqueous phase of fomesafen and 44 parts of the sodium salt aqueous phase of bentazone are successively added to the mixed solution of the oil phase and the emulsifier, stirred evenly, 8 parts of deionized water are added, and the pH is adjusted to 6.8 with glacial acetic acid and sodium hydroxide aqueous solution to obtain the long-acting herbicidal combined microemulsion.

[0035] Example 2: A preparation method of a long-acting herbicidal combined microemulsion, specifically as follows:

[0036] Step 1: Prepare the sodium salt aqueous phase of fomesafen

[0037] By mass parts, 6.0 parts of sodium hydroxide and 35.0 parts of deionized water are mixed and stirred evenly to obtain a sodium hydroxide solution. 60 parts of fomesafen technical are added to the sodium hydroxide solution, and the pH is adjusted to 8.0 with glacial acetic acid and the sodium hydroxide solution while stirring continuously to make the system react fully until the mixed solution is clear and transparent. Then, stop stirring to obtain the aqueous phase of sodium fomesafen.

[0038] Step 2: Prepare the aqueous phase of bentazone sodium

[0039] By mass parts, 7.5 parts of sodium hydroxide and 30.0 parts of deionized water are mixed and stirred evenly to obtain a sodium hydroxide solution. 60 parts of bentazone technical are added to the sodium hydroxide solution, and the pH is adjusted to 8.0 with glacial acetic acid and the sodium hydroxide solution while stirring continuously to make the system react fully until the mixed solution is clear and transparent. Then, stop stirring to obtain the aqueous phase of bentazone sodium.

[0040] Step 3: Prepare the oil phase of quizalofop-p-ethyl

[0041] By mass parts, 55 parts of xylene and 28 parts of dimethyldecanamide are mixed and stirred evenly to obtain a mixed xylene solvent. 17 parts of quizalofop-p-ethyl technical are added to 83 parts of the mixed xylene solvent and stirred evenly to obtain the oil phase of quizalofop-p-ethyl.

[0042] Step 4: Prepare the long-acting herbicidal combined microemulsion

[0043] By mass parts, 20 parts of a mixed solution of AEO-7 emulsifier and OP-9 emulsifier (mass ratio 1:1) are first mixed evenly with 20 parts of the oil phase of quizalofop-p-ethyl to form a mixed solution. Then, 18 parts of the aqueous phase of sodium fomesafen and 45 parts of the aqueous phase of bentazone sodium are successively added to the mixed solution of the oil phase and the emulsifier, stirred evenly, 12 parts of deionized water are added, and the pH is adjusted to 6.8 with glacial acetic acid and the aqueous sodium hydroxide solution to obtain the long-acting herbicidal combined microemulsion.

[0044] Example 3: A preparation method of a long-acting herbicidal combined microemulsion, specifically:

[0045] Step 1: Prepare the aqueous phase of sodium fomesafen

[0046] By mass parts, 6.0 parts of sodium hydroxide and 35.0 parts of deionized water are mixed and stirred evenly to obtain a sodium hydroxide solution. 60 parts of fomesafen technical are added to the sodium hydroxide solution, and the pH is adjusted to 8.0 with glacial acetic acid and the sodium hydroxide solution while stirring continuously to make the system react fully until the mixed solution is clear and transparent. Then, stop stirring to obtain the aqueous phase of sodium fomesafen.

[0047] Step 2: Prepare the aqueous phase of bentazone sodium

[0048] Mix 7.5 parts by mass of sodium hydroxide and 30.0 parts of deionized water, stir evenly to obtain a sodium hydroxide solution. Add 60 parts of bentazone technical to the sodium hydroxide solution, adjust the pH to 8.0 with glacial acetic acid and sodium hydroxide solution while stirring continuously, allow the system to react fully until the mixed solution is clear and transparent, stop stirring, and obtain the bentazone sodium salt aqueous phase.

[0049] Step 3: Prepare the quizalofop-p-ethyl oil phase

[0050] Mix 55 parts by mass of xylene and 28 parts of dimethyldecanamide, stir evenly to obtain a xylene mixed solvent. Add 17 parts of quizalofop-p-ethyl technical to 83 parts of the xylene mixed solvent, stir evenly to obtain the quizalofop-p-ethyl oil phase.

[0051] Step 4: Prepare the long-acting herbicidal combination microemulsion

[0052] Mix 15 parts by mass of a mixture of AEO-7 emulsifier + OP-9 emulsifier (mass ratio 1:1) with 18 parts of the quizalofop-p-ethyl oil phase first to form a mixed solution. Then add 15 parts of the fomesafen sodium salt aqueous phase and 40 parts of the bentazone sodium salt aqueous phase successively to the mixed solution of the oil phase and the emulsifier, stir evenly, add 5 parts of deionized water, and adjust the pH to 6.8 with glacial acetic acid and sodium hydroxide aqueous solution to obtain the long-acting herbicidal combination microemulsion.

[0053] Example 4: A preparation method of a long-acting herbicidal combination microemulsion, specifically as follows:

[0054] Step 1: Prepare the fomesafen sodium salt aqueous phase

[0055] Mix 6.0 parts by mass of sodium hydroxide and 35.0 parts of deionized water, stir evenly to obtain a sodium hydroxide solution. Add 60 parts of fomesafen technical to the sodium hydroxide solution, adjust the pH to 8.0 with glacial acetic acid and sodium hydroxide solution while stirring continuously, allow the system to react fully until the mixed solution is clear and transparent, stop stirring, and obtain the fomesafen sodium salt aqueous phase.

[0056] Step 2: Prepare the bentazone sodium salt aqueous phase

[0057] Mix 7.5 parts by mass of sodium hydroxide and 30.0 parts of deionized water, stir evenly to obtain a sodium hydroxide solution. Add 60 parts of bentazone technical to the sodium hydroxide solution, adjust the pH to 8.0 with glacial acetic acid and sodium hydroxide solution while stirring continuously, allow the system to react fully until the mixed solution is clear and transparent, stop stirring, and obtain the bentazone sodium salt aqueous phase.

[0058] Step 3: Prepare the quizalofop-p-ethyl oil phase

[0059] By mass, 55 parts of xylene and 28 parts of dimethyldecylamide were mixed and stirred to obtain a xylene mixed solvent, and 17 parts of Quizalofop-Ph-ethyl technical were added to 83 parts of the xylene mixed solvent, stirred to obtain a Quizalofop-Ph-ethyl oil phase.

[0060] Step 4: Preparation of long-acting herbicidal combination microemulsion

[0061] By mass, 17 parts of a mixed solution of AEO-7+OP-9 emulsifiers (mass ratio of 1:1) were first mixed evenly with 19 parts of quizalofop-p-ethyl oil phase to form a mixed solution, and then 16 parts of fomesafen sodium salt water phase and 44 parts of methicillin sodium salt water phase were successively added to the mixed solution of the oil phase and the emulsifier, 0.5 parts of methylated vegetable oil, 0.25 parts of amino oligosaccharides aqueous solution, and 5.0 parts of ethylene glycol were added, stirred evenly, 8 parts of deionized water were added, and the pH was adjusted to 6.8 with glacial acetic acid and sodium hydroxide aqueous solution to obtain a long-acting herbicide combination microemulsion.

[0062] The preparation method of the synergist methyl esterified vegetable oil is as follows:

[0063] 18 parts of peanut oil, 16 parts of methanol and 53 parts of sodium hydroxide solution were mixed, zeolite was added to prevent violent boiling, and the mixture was refluxed in a water bath at 80°C for 1 hour. After the heating was completed, a hydrochloric acid solution was added dropwise to adjust the pH to 7.0, the mixture was stirred evenly, and suction filtered to obtain higher fatty acids. 119 parts of methanol and 19.32 parts of concentrated sulfuric acid were added to the obtained higher fatty acids, the mixture was stirred evenly, and the mixture was refluxed in a water bath at 80°C for 1 hour before heating was stopped. The mixture was cooled, allowed to stand for stratification, washed with deionized water, and distilled under reduced pressure to obtain methylated peanut oil. According to the same preparation method, 18 parts of corn oil, 16 parts of methanol and 53 parts of sodium hydroxide solution were mixed to prepare methylated corn oil.

[0064] 4.0 parts of methylated peanut oil and 2.0 parts of methylated corn oil were mixed, and 0.6 parts of OP-7 emulsifier, 0.6 parts of PEG-400 emulsifier and 0.3 parts of ZR-5 emulsifier were added, stirred evenly, and fully emulsified to obtain the synergist methylated vegetable oil.

[0065] Based on Example 1, control experiments were carried out, specifically Comparative Example 1, Comparative Example 2, Comparative Example 3 and Comparative Example 4, as described below:

[0066] Comparative Example 1: This comparative example involves the preparation of a long-acting herbicide combination microemulsion, and the only difference from Example 1 is that the emulsifier used in this comparative example is AEO-5 emulsifier + 1104 emulsifier.

[0067] Specifically:

[0068] Step 1: Preparation of fomesafen sodium brine phase

[0069] By mass parts, 6.0 parts of sodium hydroxide and 35.0 parts of deionized water are mixed and stirred evenly to obtain a sodium hydroxide solution. 60 parts of fomesafen technical are added to the sodium hydroxide solution, and the pH is adjusted to 8.0 with glacial acetic acid and the sodium hydroxide solution while stirring continuously to make the system react fully until the mixed solution is clear and transparent. Then, stop stirring to obtain the aqueous phase of sodium fomesafen.

[0070] Step 2: Prepare the aqueous phase of bentazone sodium

[0071] By mass parts, 7.5 parts of sodium hydroxide and 30.0 parts of deionized water are mixed and stirred evenly to obtain a sodium hydroxide solution. 60 parts of bentazone technical are added to the sodium hydroxide solution, and the pH is adjusted to 8.0 with glacial acetic acid and the sodium hydroxide solution while stirring continuously to make the system react fully until the mixed solution is clear and transparent. Then, stop stirring to obtain the aqueous phase of bentazone sodium.

[0072] Step 3: Prepare the oil phase of quizalofop-p-ethyl

[0073] By mass parts, 55 parts of xylene and 28 parts of dimethyldecanamide are mixed and stirred evenly to obtain a mixed xylene solvent. 17 parts of quizalofop-p-ethyl technical are added to 83 parts of the mixed xylene solvent and stirred evenly to obtain the oil phase of quizalofop-p-ethyl.

[0074] Step 4: Prepare the long-acting herbicidal combination microemulsion

[0075] By mass parts, first mix 17 parts of the mixture of AEO-5 emulsifier and 1104 emulsifier (mass ratio 1:1) evenly with 19 parts of the oil phase of quizalofop-p-ethyl to form a mixed solution. Then, add 16 parts of the aqueous phase of sodium fomesafen and 44 parts of the aqueous phase of bentazone sodium to the mixed solution of the oil phase and the emulsifier successively, stir evenly, add 8 parts of deionized water, and adjust the pH to 6.8 with glacial acetic acid and the aqueous sodium hydroxide solution to obtain the long-acting herbicidal combination microemulsion.

[0076] Comparative Example 2: This comparative example relates to the preparation of a long-acting herbicidal combination microemulsion. The difference from Example 1 is only that: the emulsifier used in this comparative example is OP-9 emulsifier + 1104 emulsifier. Specifically:

[0077] Step 1: Prepare the aqueous phase of sodium fomesafen

[0078] By mass parts, 6.0 parts of sodium hydroxide and 35.0 parts of deionized water are mixed and stirred evenly to obtain a sodium hydroxide solution. 60 parts of fomesafen technical are added to the sodium hydroxide solution, and the pH is adjusted to 8.0 with glacial acetic acid and the sodium hydroxide solution while stirring continuously to make the system react fully until the mixed solution is clear and transparent. Then, stop stirring to obtain the aqueous phase of sodium fomesafen.

[0079] Step 2: Prepare the aqueous phase of bentazone sodium

[0080] Mix 7.5 parts by mass of sodium hydroxide and 30.0 parts of deionized water, stir evenly to obtain a sodium hydroxide solution. Add 60 parts of bentazone technical to the sodium hydroxide solution, adjust the pH to 8.0 with glacial acetic acid and sodium hydroxide solution while stirring continuously, and allow the system to react fully until the mixture becomes clear and transparent. Then stop stirring to obtain the bentazone sodium salt aqueous phase.

[0081] Step 3: Prepare the quizalofop-P-ethyl oil phase

[0082] Mix 55 parts by mass of xylene and 28 parts of dimethyldecanamide, stir evenly to obtain a xylene mixed solvent. Add 17 parts of quizalofop-P-ethyl technical to 83 parts of the xylene mixed solvent, stir evenly to obtain the quizalofop-P-ethyl oil phase.

[0083] Step 4: Prepare the long-acting herbicide combination microemulsion

[0084] Mix 17 parts by mass of a mixture of OP-9 emulsifier and 1104 emulsifier (mass ratio 1:1) with 19 parts of the quizalofop-P-ethyl oil phase first to form a mixed solution. Then add 16 parts of the fomesafen sodium salt aqueous phase and 44 parts of the bentazone sodium salt aqueous phase successively to the mixed solution of the oil phase and the emulsifier, stir evenly, add 8 parts of deionized water, and adjust the pH to 6.8 with glacial acetic acid and sodium hydroxide aqueous solution to obtain the long-acting herbicide combination microemulsion.

[0085] Comparative Example 3: This comparative example relates to the preparation of a long-acting herbicide combination microemulsion, and the difference from Example 1 is only that: when preparing the long-acting herbicide combination microemulsion in this comparative example, the pH is adjusted to 7.8. Specifically:

[0086] Step 1: Prepare the fomesafen sodium salt aqueous phase

[0087] Mix 6.0 parts by mass of sodium hydroxide and 35.0 parts of deionized water, stir evenly to obtain a sodium hydroxide solution. Add 60 parts of fomesafen technical to the sodium hydroxide solution, adjust the pH to 8.0 with glacial acetic acid and sodium hydroxide solution while stirring continuously, and allow the system to react fully until the mixture becomes clear and transparent. Then stop stirring to obtain the fomesafen sodium salt aqueous phase.

[0088] Step 2: Prepare the bentazone sodium salt aqueous phase

[0089] Mix 7.5 parts by mass of sodium hydroxide and 30.0 parts of deionized water, stir evenly to obtain a sodium hydroxide solution. Add 60 parts of bentazone technical to the sodium hydroxide solution, adjust the pH to 8.0 with glacial acetic acid and sodium hydroxide solution while stirring continuously, and allow the system to react fully until the mixture becomes clear and transparent. Then stop stirring to obtain the bentazone sodium salt aqueous phase.

[0090] Step 3: Prepare the quizalofop-p-ethyl oil phase

[0091] By mass, mix 55 parts of xylene and 28 parts of dimethyldecanamide, stir evenly to obtain a xylene mixed solvent, add 17 parts of quizalofop-p-ethyl technical to 83 parts of the xylene mixed solvent, stir evenly to obtain the quizalofop-p-ethyl oil phase.

[0092] Step 4: Prepare the long-acting herbicidal combination microemulsion

[0093] By mass, first mix 17 parts of a mixture of AEO-7 emulsifier and OP-9 emulsifier (mass ratio 1:1) evenly with 19 parts of the quizalofop-p-ethyl oil phase to form a mixed solution, then successively add 16 parts of the sodium salt aqueous phase of fomesafen and 44 parts of the sodium salt aqueous phase of bentazone to the mixed solution of the oil phase and the emulsifier, stir evenly, add 8 parts of deionized water, and adjust the pH to 7.8 with glacial acetic acid and sodium hydroxide aqueous solution to obtain the long-acting herbicidal combination microemulsion.

[0094] Comparative Example 4: This comparative example relates to the preparation of a long-acting herbicidal combination microemulsion. The difference from Example 1 is only that: when preparing the long-acting herbicidal combination microemulsion in this comparative example, the pH is adjusted to 5.8. Specifically:

[0095] Step 1: Prepare the sodium salt aqueous phase of fomesafen

[0096] By mass, mix 6.0 parts of sodium hydroxide and 35.0 parts of deionized water, stir evenly to obtain a sodium hydroxide solution, add 60 parts of fomesafen technical to the sodium hydroxide solution, adjust the pH to 8.0 with glacial acetic acid and sodium hydroxide solution and stir continuously to make the system react fully until the mixed solution is clear and transparent, stop stirring to obtain the sodium salt aqueous phase of fomesafen.

[0097] Step 2: Prepare the sodium salt aqueous phase of bentazone

[0098] By mass, mix 7.5 parts of sodium hydroxide and 30.0 parts of deionized water, stir evenly to obtain a sodium hydroxide solution, add 60 parts of bentazone technical to the sodium hydroxide solution, adjust the pH to 8.0 with glacial acetic acid and sodium hydroxide solution and stir continuously to make the system react fully until the mixed solution is clear and transparent, stop stirring to obtain the sodium salt aqueous phase of bentazone.

[0099] Step 3: Prepare the quizalofop-p-ethyl oil phase

[0100] By mass, mix 55 parts of xylene and 28 parts of dimethyldecanamide, stir evenly to obtain a xylene mixed solvent, add 17 parts of quizalofop-p-ethyl technical to 83 parts of the xylene mixed solvent, stir evenly to obtain the quizalofop-p-ethyl oil phase.

[0101] Step 4: Prepare the long-acting herbicidal combination microemulsion

[0102] By mass, first mix 17 parts of a mixture of AEO-7 emulsifier and OP-9 emulsifier (mass ratio 1:1) evenly with 19 parts of quizalofop-p-ethyl oil phase to form a mixed solution. Then, add 16 parts of fomesafen sodium aqueous phase and 44 parts of bentazone sodium aqueous phase successively to the mixed solution of oil phase and emulsifier, stir evenly, add 8 parts of deionized water, and adjust the pH to 5.8 with glacial acetic acid and sodium hydroxide aqueous solution to obtain a long-acting herbicidal combination microemulsion.

[0103] Detection experiment:

[0104] Microemulsion stability test: According to the processes in Example 1, Example 2, Example 3, Example 4, Comparative Example 1, Comparative Example 2, Comparative Example 3, and Comparative Example 4, prepare equal amounts of long-acting herbicidal combination microemulsion samples. Divide the 7 samples into 3 parts evenly. Seal one part and store it in a constant temperature oven at 0°C for 14 days. Place the other two parts of the samples in a constant temperature oven at -5°C for 7 days and at 54°C for 28 days respectively according to the same method. After storage, take out the samples, observe the state, and judge the stability of the samples at different temperatures.

[0105] Determination of effective content: Determine according to the "General Analytical Method for the Determination of the Content of Active Ingredients in Pesticide Products - Gas Chromatography Method". Weigh 0.1 g of each long-acting herbicidal combination microemulsion sample and dilute it to 50 mL with the mobile phase (m 正己烷 :m 异丙醇 = 90:10), ultrasonically disperse for 5 min. Pipette 5 mL of the mixed solution respectively, and dilute it to 50 mL again with the above mobile phase to obtain each test solution. Use a high-performance liquid chromatograph to determine the effective content of quizalofop-p-ethyl in the test solution.

[0106]

[0107] Conclusion: According to the test data, it can be seen that the long-acting herbicidal combination microemulsion of the present invention has excellent cold storage stability, freeze stability, and heat storage stability.

[0108] By comparing the data of Comparative Example 1 and Comparative Example 2 with Example 1, it can be known that the cold storage stability, freeze stability, and heat storage stability of the long-acting herbicidal combination microemulsion are related to the emulsifier used. After changing the components of the emulsifier in Comparative Example 1 and Comparative Example 2, the stability of the prepared long-acting herbicidal combination microemulsion becomes significantly worse.

[0109] By comparing the data of Comparative Example 3 and Comparative Example 4 with Example 1, it can be known that the decomposition rate of quizalofop-p-ethyl is related to the pH of the long-acting herbicidal combination microemulsion. Too high or too low pH will increase the decomposition rate of quizalofop-p-ethyl and affect the long-term storage of the long-acting herbicidal combination microemulsion.

[0110] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, in any regard, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Accordingly, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention.

Claims

1. A long-acting herbicidal combined microemulsion, characterized in that: By mass, the long-acting herbicidal combined microemulsion mainly comprises 18 - 20 parts of quizalofop-p-ethyl oil phase, 15 - 20 parts of emulsifier, 15 - 18 parts of fomesafen sodium aqueous phase, 40 - 45 parts of bentazone sodium aqueous phase, and 5 - 12 parts of deionized water.

2. The long-acting weeding combined microemulsion according to claim 1, characterized in that: By mass, the amounts of each component in the quizalofop-p-ethyl oil phase are: 15 - 20 parts of quizalofop-p-ethyl technical, 50 - 60 parts of xylene, and 25 - 30 parts of dimethyldecanamide.

3. The long-acting herbicidal combined microemulsion according to claim 1, characterized in that: By mass, the amounts of each component in the fomesafen sodium aqueous phase are: 50 - 70 parts of fomesafen technical, 5 - 7 parts of sodium hydroxide, and 30 - 40 parts of deionized water.

4. The long-acting weeding combined microemulsion according to claim 1, characterized in that: By mass, the amounts of each component in the bentazone sodium aqueous phase are: 50 - 70 parts of bentazone technical, 6 - 9 parts of sodium hydroxide, and 25 - 35 parts of deionized water.

5. The long-acting weeding combined microemulsion according to claim 1, characterized in that: The emulsifier used is one or a combination of AEO-5 emulsifier, AEO-7 emulsifier, and OP-9 emulsifier.

6. A preparation method of a long-acting weeding combined microemulsion, characterized in that: Specifically: First, mix the emulsifier evenly with the quizalofop-p-ethyl oil phase to form a mixed solution. Then, successively add the fomesafen sodium aqueous phase and the bentazone sodium aqueous phase to the mixed solution of the quizalofop-p-ethyl oil phase and the emulsifier, stir evenly, add deionized water, and adjust the pH to 6.5 - 7.0 with glacial acetic acid and sodium hydroxide aqueous solution to obtain the long-acting herbicidal combined microemulsion.

7. The preparation method of a long-acting weeding combined microemulsion according to claim 6, characterized in that: The preparation method of the fomesafen sodium aqueous phase or the bentazone sodium aqueous phase is: Mix sodium hydroxide and deionized water, stir evenly to obtain a sodium hydroxide solution. Add fomesafen technical or bentazone sodium technical to the sodium hydroxide solution, adjust the pH to 7.0 - 10.0 with glacial acetic acid and sodium hydroxide solution and keep stirring to make the system react fully until the mixed solution is clear and transparent. Stop stirring to obtain the fomesafen sodium aqueous phase or the bentazone sodium aqueous phase.

8. The preparation method of a long-acting weed control combined microemulsion according to claim 6, characterized in that: By mass fraction, when preparing the long-acting herbicidal combined microemulsion, 0.4 - 0.6% of methylated vegetable oil, 0.2 - 0.3% of amino-oligosaccharide aqueous agent, and 4 - 6% of ethylene glycol based on the total mass of the long-acting herbicidal combined microemulsion can also be added.

9. The preparation method of a long-acting weeding combined microemulsion according to claim 8, characterized in that: The preparation method of the methylated vegetable oil is: Mix peanut oil, methanol, and sodium hydroxide solution, add zeolite to prevent bumping, reflux and heat in a water bath at 70 - 90 °C for 0.5 - 1.5 h. After heating is completed, drop in hydrochloric acid solution to adjust the pH, stir evenly, filter by suction to obtain higher fatty acids. Add methanol and concentrated sulfuric acid to the obtained higher fatty acids, stir evenly, reflux and heat in a water bath at 70 - 90 °C for 0.5 - 1.5 h, then stop heating, cool, let it stand for layering, wash with deionized water, and distill under reduced pressure to obtain methylated peanut oil. According to the same preparation method, mix corn oil, methanol, and sodium hydroxide solution to prepare methylated corn oil; Mix methylated peanut oil and methylated corn oil, add OP-7 emulsifier, PEG-400 emulsifier, and ZR-5 emulsifier, and stir evenly to obtain the synergist methylated vegetable oil.

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