A controlled release herbicidal composition and methods of making and using the same

Abstract

The present application relates to a kind of controllable release herbicide composition and its preparation method, the controllable release herbicide composition includes active ingredient 1-60 parts, 10-30 parts of load agent with porous structure, 10-20 parts of water-absorbing expansion material and 40-60 parts of solvent;Wherein, at least part of the active ingredient and at least part of the water-absorbing expansion material are located inside and surface of the load agent.The herbicide composition of the present application can achieve the effect of controllable slow release, improve the storage effect of herbicide composition under dry and wet conditions, improve the use efficiency of herbicide composition, improve the foliage concentration of vegetation, reduce the invalid degradation of active ingredient, improve the killing effect of herbicide composition on tuberous plants, perennial herbaceous plants and other various plants.

Description

Technical Field

[0001] This invention belongs to the field of herbicide technology, specifically relating to a controlled-release herbicidal composition and its preparation and application methods. Background Technology

[0002] With the development of agricultural technology, chemical weeding has become the mainstream weed control technology. Herbicides account for more than 60% of the total pesticide demand. Various compound herbicides and different types of herbicides have gradually emerged. With technological advancements, weed control technologies also face more demands, such as application cost, weed control timeliness, broad weed control spectrum, low toxicity of herbicides, and biodegradability.

[0003] With the gradual banning of highly toxic pesticides such as paraquat worldwide, glyphosate has become the mainstream herbicide for weed control. However, it has been found that glyphosate has a long weed-killing time, and weeds resistant to glyphosate are constantly emerging. Glufosinate is gradually becoming the mainstream herbicide due to its broad spectrum of weed control and rapid action.

[0004] The mechanism of glufosinate's weed control: It enters the plant through transpiration stomata on the leaf surface, interrupting the physiological process of glutamate synthesis, causing abnormal ammonia nitrogen metabolism and leading to plant damage and death. Glufosinate requires a concentration greater than 50 ppm on the plant leaf surface to produce a significant weed-controlling effect. Glufosinate is water-soluble; rainfall within 24 hours of application will reduce its weed-controlling effect. Furthermore, glufosinate requires a certain level of moisture to enter the plant leaf stomata and achieve its killing effect. If the plant surface has a thick waxy layer, glufosinate is less likely to enter the plant and is easily washed away by natural rainfall, losing its weed-controlling effect. Similarly, in areas with low temperatures or low humidity, glufosinate degrades before the plant can fully absorb it, resulting in ineffective weed control. Glufosinate has a half-life of approximately 200–600 days in water, but only 1.2–1.5 days in natural soil. Under natural conditions, a single application of glufosinate provides effective weed control for only about 20 days. This leads to many practical weed control problems, such as low actual effective utilization rate of glufosinate, short weed control time, and high usage cost.

[0005] Therefore, slow-release pesticides have emerged in existing technologies. For example, porous materials are used as physical carriers to mix pesticides with these materials to prepare slow-release pesticides. However, the release rate of pesticides prepared in this way is uncontrollable, and they are usually released in large quantities within a short period of time with rainwater, resulting in poor slow-release effects and a relatively short weed control time. Therefore, there is an urgent need for technological updates to solve these problems. Summary of the Invention

[0006] The purpose of this invention is to provide a controllable release herbicidal composition that enables the active ingredients to be gradually released as the external environment changes in humidity, as well as its preparation method and application method.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] The first aspect of the present invention provides a controlled-release herbicidal composition, comprising, by weight, 1 to 60 parts of an active ingredient, 10 to 30 parts of a loading agent having a porous structure, 10 to 20 parts of a water-absorbing and swelling material, and 40 to 60 parts of a solvent; wherein at least a portion of the active ingredient and at least a portion of the water-absorbing and swelling material are located inside and on the surface of the loading agent.

[0009] This invention involves dissolving the active ingredient and water-absorbing, swelling material in a solvent and loading them into the pores of a loading agent. When applied to the weeds, the herbicidal composition accumulates in the flower centers, leaf centers, veins, and root veins of the weeds. Furthermore, as the external environment changes between wet and dry, the loading agent in the herbicidal composition expands and contracts layer by layer from the outside in, along with the water-absorbing, swelling material, allowing for the controlled release of the active ingredient loaded in the pores of the loading agent. This increases the concentration of the herbicide on the plant leaves and reduces the ineffective degradation of the active ingredient. Specifically, when a dry herbicidal composition encounters rainfall, the water-swellable material, which has not yet absorbed water and swelled, is in a smaller volume. Rainwater can enter the pores of the loading agent, causing the water-swellable material to absorb water and swell. As the outer layer of water-swellable material increases in volume, the more fragile outer layer of the loading agent breaks down after exposure to wind and sun, releasing the active ingredients and other substances. By controlling the formulation of the herbicidal composition, the released active ingredients can achieve an effective herbicidal concentration (e.g., glufosinate-ammonium reaching 50 ppm or more). Meanwhile, the pores of the loading agent in the unbroken areas are blocked by the water-swellable material, preventing further dissolution of the active ingredients. After the weather clears, the water in the water-swellable material evaporates, and its volume shrinks. Thus, during and after the next rainfall, the active ingredients are released according to the above mechanism.

[0010] According to some specific embodiments, the number of parts of the active ingredient is 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, 30 parts. 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59 or 60 portions; preferably 5 to 30 portions.

[0011] According to some specific embodiments, the number of parts of the loading agent is 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 or 30 parts; preferably 10 to 20 parts.

[0012] According to some specific embodiments, the number of parts of the water-absorbing and swelling material is 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20.

[0013] According to some specific embodiments, the solvent is in the form of 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59 or 60 parts.

[0014] According to some specific embodiments, the active ingredients are a first active ingredient and a second active ingredient with a mass ratio of 0.01 to 100:1, wherein the first active ingredient is glufosinate and / or succinate, and the second active ingredient is sulfopyrazine.

[0015] Further, the mass ratio of the first active ingredient to the second active ingredient is 0.01:1, 0.05:1, 0.1:1, 0.5:1, 1:1, 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 45:1, 50:1, 55:1, 60:1, 65:1, 70:1, 75:1, 80:1, 85:1, 90:1, 95:1, or 100:1, preferably 1 to 50:1.

[0016] Sulfonazole appears as white crystals or white crystalline powder, with a melting point of 130.7℃. Solubility (20℃): 3.49 × 10⁻⁶ in water.-3 g / L (20℃±0.5℃); in organic solvents (g / L): n-hexane 0.072, toluene 11.3, dichloromethane 151, methanol 11.4, ethyl acetate 97, acetone >250. 40% sulfonylpyrazole suspension concentrate, pH 5.5~8.5; fineness (passing through a 75μm test sieve) ≥98%; suspension rate ≥80%. The product is stable under cold and hot storage and at room temperature for 2 years. Sulfonylpyrazole is a novel pyrazole selective herbicide, applied pre-emergence to control grass and broadleaf weeds in dryland crop fields. It has a wide application time range, from pre-planting to post-emergence, and is compatible with most commonly used herbicides. Its mechanism of action is that treatment with sulfonylpyrazole significantly reduces the biosynthesis of very long chain fatty acids (VLCFAs) and induces the construction of fatty acid precursors. Sulfonylpyrazole specifically inhibits many elongation steps catalyzed by VLCFA elongases. Indoor activity tests and field efficacy tests showed that 40% sulfopyrazole suspension had a good control effect on annual grass weeds such as winter wheat, wild oat, and wild millet, as well as some annual broadleaf weeds such as shepherd's purse, shepherd's purse, and cleavers.

[0017] This invention, by combining two active ingredients in a specific ratio, can broaden the weed control spectrum of the herbicidal composition and increase its effectiveness against broadleaf weeds.

[0018] According to some specific embodiments, the water-absorbing and swelling material is polyvinyl alcohol.

[0019] According to some specific embodiments, the loading agent is selected from one or more combinations of molecular sieves, silica, diatomaceous earth, and organic one-dimensional and two-dimensional cystic mesoporous structure complexes.

[0020] According to some specific and preferred embodiments, the pore size of the porous structure of the loading agent is one or more of micropores, mesopores, and macropores.

[0021] According to some specific and preferred embodiments, the pore size range of the porous structure of the supporting agent is 5 nm to 200 μm. Here, the pore size of the supporting agent refers to the range of diameters of the smallest and largest pores in the supporting agent; in practice, the supporting agent typically contains a porous structure system with pores of varying diameters.

[0022] More preferably, the pore size of the loading agent is in the range of 0.3 μm to 200 μm.

[0023] More preferably, at least some of the pores in the porous structure of the loading agent are blind pores.

[0024] According to some specific and preferred embodiments, the loading agent is in powder form, and the particle size of the powdered loading agent is such that it can be sprayed out in the form of a spray after being diluted with water in a controlled manner without clogging the nozzle.

[0025] Furthermore, after the loading agent is calcined under vacuum to remove the gas from the porous structure, it is mixed with other components of the controlled-release herbicidal composition, excluding the loading agent, under negative pressure to obtain the controlled-release herbicidal composition.

[0026] This invention utilizes vacuum conditions to calcine the support agent, effectively removing air and moisture from its pores. Then, a mixture containing the active ingredient and water-absorbing, swelling material is drawn in using negative pressure suction. This allows the active ingredient mixture to penetrate as much of the support agent's pores as possible, thereby increasing the loading capacity. If conventional methods are used to mix the support agent with the active ingredient mixture, the active ingredient typically remains on the surface of the support agent and cannot effectively penetrate its pores, resulting in a lower loading capacity and hindering long-term, controllable release.

[0027] According to some specific embodiments, the vacuum degree of the vacuum calcination is 0.1 to 100 kPa, for example 0.1 kPa, 1 kPa, 5 kPa, 10 kPa, 15 kPa, 20 kPa, 25 kPa, 30 kPa, 35 kPa, 40 kPa, 45 kPa, 50 kPa, 55 kPa, 60 kPa, 65 kPa, 70 kPa, 75 kPa, 80 kPa, 85 kPa, 90 kPa, 95 kPa, 100 kPa; preferably 10 to 80 kPa, and more preferably 50 to 100 kPa.

[0028] According to some specific embodiments, the calcination temperature of the vacuum calcination is 200-1000℃, for example, 200℃, 210℃, 220℃, 230℃, 240℃, 250℃, 260℃, 270℃, 280℃, 290℃, 300℃, 310℃, 320℃, 330℃, 340℃, 350℃, 360℃, 370℃, 380℃, 390℃, 400℃, 410℃, 420℃, 430℃, 440℃, 450℃, 460℃, 470℃, 480℃, 490℃, 500℃, 510℃, 520℃, 530℃, 540℃, 550℃, 560℃, 570℃, 580℃, and 590℃. Temperatures range from 600℃ to 1000℃; preferably 200 to 700℃, and more preferably 300 to 500℃.

[0029] According to some specific implementations, the mixing temperature is room temperature.

[0030] According to some specific embodiments, the loading amount of the loading agent is 5% to 90%.

[0031] According to some specific embodiments, the controlled-release herbicide composition has a weed control period of more than 200 days.

[0032] According to some specific embodiments, the controlled-release herbicidal composition releases 0.1% to 3% of the active ingredient by mass per wetting cycle.

[0033] According to some specific embodiments, the solvent is one or more of water, ethanol, isopropanol, NMP, and natural mineral oil.

[0034] According to some specific embodiments, the controlled-release herbicide composition further includes 5 to 15 parts of a synergist. By adding a synergist, the adhesion of the herbicide to the leaf surface can be improved, making it easier for the active ingredients, especially glufosinate and / or succinate, to enter the stomata of the leaves. This improves the herbicide's effectiveness in low-temperature areas, dry areas, or on thick-leaved waxy plants, thereby expanding the applicability of the controlled-release herbicide composition and reducing limitations on temperature, humidity, and the types of plants it can kill.

[0035] According to some specific and preferred embodiments, the number of parts of the synergist is 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15.

[0036] More preferably, the synergistic agent comprises a pH adjuster, a foliar wetting agent, and a stomatal opener in a mass ratio of 1:0.05–10:0.1–50. The combined use of the pH adjuster, foliar wetting agent, and stomatal opener facilitates the entry of active ingredients into the plant's stomata, thereby shortening the onset time of the active ingredients and achieving a rapid effect. Compared to glufosinate-ammonium herbicides that use only a foliar wetting agent as a synergist, where the weeds typically begin to turn yellow 2–3 days after application, the glufosinate-ammonium herbicides using the synergistic agent of this application begin to turn yellow 1–2 days after application.

[0037] More preferably, the mass ratio of the pH adjuster, the leaf wetting agent, and the stomatal opener is 1:0.1-8:0.1-40, preferably 1:0.4-8:0.1-20, preferably 1:1-7:0.1-10, preferably 1:1-5:0.1-5, preferably 1:1-5:0.1-2, preferably 1:1-5:0.1-1, and preferably 1:1-5:0.1-0.7.

[0038] More preferably, the pH adjuster comprises one or more combinations of sodium pyrophosphate, ammonium phosphate, ammonium hydrogen phosphate, sodium borate, and sodium citrate.

[0039] More preferably, the leaf wetting agent includes one or more of fatty acid polyoxyethylene esters, OP-type surfactants and Tween-type surfactants; preferably, it is a combination of two or three.

[0040] More preferably, the pore-opening agent includes vanillin and / or sesquiterpene plant growth hormones.

[0041] According to some specific embodiments, the controlled-release herbicidal composition further includes 1 to 10 parts of an anti-volatilizer. Specifically, the anti-volatilizer is present in parts of 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10.

[0042] More preferably, the anti-volatile agent is one or more combinations selected from Silwet DRS60, TERMIX5920, AG-910, Maidao and SD-90.

[0043] This application, by further adding an anti-volatilization agent, can better improve the effectiveness of the controlled-release herbicide composition in arid areas, further enhance the surface wetting effect of the controlled-release herbicide composition, and, through the addition of the anti-volatilization agent, enable the controlled-release herbicide composition of this application to be sprayed by drones, thereby improving the efficiency of pesticide application, reducing labor costs, and reducing the harm of pesticides to the human body.

[0044] According to some specific embodiments, the controlled-release herbicidal composition further includes 0.1 to 5 parts of an odorant, wherein the odorant is one or more of tetrahydrothiophene, butyl mercaptan, n-propanethiol, and dibutyl sulfide.

[0045] According to some specific embodiments, the controlled-release herbicidal composition is formulated by weight as follows: 5-30 parts of active ingredient, 10-20 parts of loading agent, 10-20 parts of water-absorbing and swelling material, 5-15 parts of synergist, 1-10 parts of anti-volatilization agent, 0.1-5 parts of odorant, and 40-60 parts of solvent.

[0046] According to some embodiments, the state of the herbicidal composition can be controlled by adjusting the dosage ratio of the loading agent and other components. For example, when the dosage of the loading agent is increased to the point where it can completely adsorb other components into the pores of the loading agent, the herbicidal composition will be in a solid state. In this case, the solid herbicidal composition can be diluted with water and sprayed or sown. When the dosage of the loading agent is insufficient to completely absorb other components, the herbicidal composition is a liquid formulation, with at least a portion of the active ingredients located in a liquid other than the loading agent, such as a suspension. In this case, the controlled-release herbicidal composition can also be directly diluted with water and sprayed, or it can be centrifuged, with the solution portion diluted with water and sprayed, while the separated solid portion can be sown.

[0047] According to some specific and preferred embodiments, the controlled-release herbicidal composition is a liquid formulation, wherein at least a portion of the active ingredient is located in a liquid other than the loading agent.

[0048] A second aspect of the present invention provides a method for preparing the above-mentioned controlled-release herbicidal composition, comprising the following steps:

[0049] (1) Mix all components except the loading agent to prepare a liquid mixture;

[0050] (2) The loading agent is heated and calcined under vacuum conditions, and then cooled to room temperature;

[0051] (3) Under negative pressure, the liquid mixture prepared in step (1) is mixed and stirred with the loading agent cooled in step (2) to obtain a controllable release herbicidal composition.

[0052] A third aspect of the present invention provides a method for using the above-mentioned controlled-release herbicidal composition, wherein the controlled-release herbicidal composition is diluted with water and then applied by aerosol spraying.

[0053] The controlled-release herbicide composition of the present invention is used to control harmful plants in crops, pastures, green spaces / lawns, orchards, or non-cultivated land; the effective period is 1 to 2 days.

[0054] Furthermore, the controlled-release herbicidal composition of the present invention is used to control harmful plants in wheat, corn, rice, soybean, sugar beet, sugarcane, cotton, legumes, flax, barley, rapeseed, potato, sorghum, various vegetables, various fruit trees, pasture, green spaces / lawns, orchards, or on non-cultivated land.

[0055] This invention can achieve precise adjustment of the loading amount between 0.1% and 90% by controlling the pore size of the loading agent, the type of loading agent, and the amount of each component added. Furthermore, by controlling the water-absorbing and swelling material, the controllable release herbicidal composition of this application has a controllable cycle effect, which can accurately release the active ingredients according to the dry and wet cycle of the external environment, and the release cycle is precisely controllable with a controllable range of more than 0.1% / cycle.

[0056] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0057] The herbicidal composition of this invention stores and accommodates active ingredients and water-absorbing and swelling materials within the pores of a loading agent. Through changes in the external environment's humidity, a cyclical process occurs: the outer layer of the loading agent breaks down, the active ingredient is released, the water-absorbing and swelling material absorbs water and swells, sealing the pores of the loading agent to prevent the dissolution of the active ingredient, the water-absorbing and swelling material shrinks, the outer layer of the loading agent cracks, the water-absorbing and swelling material absorbs water and swells, the outer layer of the loading agent breaks down, and the active ingredient is released. This allows the herbicidal composition of this application to achieve a controlled, slow release effect, improves the preservation effect of the herbicidal composition under dry and wet conditions, improves the application efficiency of the herbicidal composition, increases the foliar efficacy concentration of the herbicide, reduces the ineffective degradation of the active ingredient, and enhances the killing effect of the herbicidal composition on various types of plants, including tuberous plants and perennial herbaceous plants. Attached Figure Description

[0058] Figure 1 Microscopic image of the loading agent;

[0059] Figure 2 This is a schematic diagram of the structure of the herbicidal composition, wherein 1 is the core layer of the loading agent; 2 is the loading layer on which the loading agent is loaded with the herbicide; and 3 is the break-release layer.

[0060] Figure 3This is a schematic diagram of the drug release process in a single pore of the loaded agent. Detailed Implementation

[0061] The inventors of this invention have comprehensively considered and deeply researched a herbicidal composition prepared using a loading agent and water-absorbing and swelling materials. This composition allows a large amount of active ingredients and water-absorbing and swelling materials to be loaded into the pores of the loading agent. The outer layer of the loading agent weathers and loosens under external influences such as sunlight. During the next rainfall, while the active ingredients dissolve, the outer layer of water-absorbing and swelling material absorbs water and swells, causing the outer loading agent to break down. The inner layer of water-absorbing and swelling material absorbs water and swells, blocking the pores of the loading agent and preventing the dissolution of the inner active ingredients. Thus, with each wet-dry cycle, the active ingredients in the loading agent can be released in a controlled manner, rather than being released in large quantities with rainwater, achieving a longer-term controlled release of the herbicide. Furthermore, because the loading agent, which adsorbs a large amount of active ingredients and water-absorbing and swelling materials, can accumulate in the concave parts of weeds such as the flower centers and leaf centers, when tuberous weeds or perennial weeds sprout new shoots, the released active ingredients can kill the sprouts. At this time, the amount of active ingredients required to kill the new shoots is relatively small, thereby achieving the removal effect on tuberous weeds and perennial weeds.

[0062] Furthermore, by employing a specific method to load the herbicide into the pores of the loading agent, the controlled release time was further extended, increasing the herbicide loading capacity. Further, different types of herbicides were compounded to enhance the weed control spectrum. Moreover, by adding different types of synergists, the herbicide's absorption by vegetation was improved, reducing the application conditions required for herbicide use.

[0063] All features disclosed in this invention, or all steps in the disclosed methods or processes, may be combined in any way except for mutually exclusive features or steps.

[0064] The technical solution of the present invention will be further described below with reference to specific embodiments. However, the present invention should not be limited to these embodiments. Unless specifically stated otherwise, all features can be replaced by other equivalent or similar features. Unless specifically stated otherwise, each feature is only one example of a series of equivalent or similar features. All contents mentioned below are mass contents, parts are parts by mass, and "%" is a percentage by mass. Unless otherwise specified in the following embodiments, all raw materials are commercially available or prepared by conventional methods in the art. The room temperature in the following embodiments is 25℃±5℃.

[0065] The loading agents used in the following embodiments are all commercially available, for example, they can be purchased from Zibo Qichuang New Materials Technology Co., Ltd., Jiangsu Xianfeng Nanomaterials Technology Co., Ltd., Jilin Yuantong Mining Co., Ltd., etc.

[0066] Glufosinate and / or glufosinate-ammonium TC are supplied by Zhejiang Yongnong Chemical Co., Ltd.

[0067] Sulfonazole was supplied by Shanghai Qunli Chemical Co., Ltd.

[0068] The fatty acid polyoxyethylene ester is model CE-10 from Jiangsu Haian Petrochemical Plant.

[0069] The OP-type surfactant is model OP-10 from Jiangsu Haian Petrochemical Plant Company;

[0070] The Tween-type surfactant is model TW-80 from Jiangsu Haian Petrochemical Plant Company;

[0071] Vanillin hormones are produced by Shanghai Kangtuo Chemical Co., Ltd.

[0072] The sesquiterpene hormone was *Zhu Luan* sesquiterpene ((+)-Valeniaene), provided by Shanghai Jizhi Biochemical Technology Co., Ltd.

[0073] AG-910 is an aerial spraying additive from Momentive Advanced Materials Group;

[0074] Maidao is an aerial spraying adjuvant of Beijing Guangyuan Yinong Chemical Co., Ltd.

[0075] SD-90 is an aerial spraying additive from Shanghai Shida Polymer Materials Co., Ltd.

[0076] The polyvinyl alcohol is model 1788 from Henan Dingxiang Chemical Products Co., Ltd.

[0077] The ethanol aqueous solution used in the following examples has a concentration of 70%, which is commercially available or can be prepared at home.

[0078] Examples 1 to 4

[0079] The active ingredients, synergists, odorants, anti-volatile agents, water-absorbing and swelling materials, and solvents are mixed and stirred according to the mass proportions shown in Table 1 to obtain a liquid mixture;

[0080] In a vacuum calcining furnace, the loading agent is calcined for about 2 hours at the vacuum degree and calcination temperature shown in Table 1 to fully remove air and moisture from the pores of the loading agent. After cooling to room temperature, the vacuum calcining furnace is kept under negative pressure. The above liquid mixture is introduced into the vacuum calcining furnace through a pipe. The stirring device is turned on to fully mix the liquid mixture with the loading agent to obtain a controllable release herbicidal composition.

[0081] Table 1

[0082]

[0083]

[0084] The loading test method in Table 1 is as follows: Weigh the raw material loading agent (i.e., the loading agent before the above-mentioned vacuum calcination), and record it as W1. Centrifuge the prepared controlled-release herbicidal composition to precipitate the loading agent, perform solid-liquid separation, and weigh the separated loading agent, recording it as W2. Loading amount = (W2-W1) / W1*100%.

[0085] Comparative Example 1

[0086] The formulation and components of Comparative Example 1 are the same as those of Example 1, except for the preparation method. The preparation method of Comparative Example 1 is as follows:

[0087] The active ingredient, synergist, odorant, anti-volatile agent, water-absorbing and swelling material, and solvent are mixed and stirred according to the mass ratio to obtain a liquid mixture; then the loading agent is mixed and stirred evenly with the liquid mixture to obtain the herbicidal composition of Comparative Example 1.

[0088] Comparative Example 2

[0089] Comparative Example 2 is basically the same as Example 1, except that the water-absorbing and swelling material in Example 1 is omitted in Comparative Example 1.

[0090] Experimental results

[0091] 1. Release rate test per wetting cycle

[0092] The method for testing the release amount per wetting cycle is as follows: Take 20g of the herbicidal composition of each example and comparative example, add it to 5L of water and soak for 12 hours. Centrifuge to precipitate the loading agent, and perform solid-liquid separation to obtain the loading agent. After exposing the loading agent to the sun, add it to 1L of water and soak for 12 hours to fully dissolve the active ingredients on the surface of the loading agent in the water. Centrifuge to precipitate the loading agent, and perform solid-liquid separation to obtain the loading agent. After exposing the loading agent to the sun again, repeat the above soaking and centrifugation steps 3 times to fully wash away the active ingredients on the surface of the loading agent, so that the test results of the release amount per wetting cycle are more accurate. Add the loading agent collected after the fourth centrifugation and sun exposure to 1L of water and soak for 12 hours. Then, use the existing liquid chromatography-mass spectrometry method to determine the concentration of glufosinate in the water, and calculate the percentage of the mass of glufosinate released by these loading agents during this soaking to the mass of glufosinate initially loaded in the loading agent, which is the release amount per wetting cycle.

[0093] The test results for each embodiment and comparative example are shown in Table 2 below.

[0094] Table 2

[0095]

[0096] Comparing Example 1 and Comparative Example 1 in Table 2 above, it can be seen that by vacuum calcining the loading agent and then mixing it with the liquid mixture containing the active ingredient under negative pressure, a large amount of the liquid can be ensured to enter the pores of the loading agent, rather than just being loaded on the surface of the loading agent, thus increasing the loading capacity of the loading agent. Therefore, the release amount per wetting cycle in Example 1 is higher than that in Comparative Example 1. Furthermore, comparing Example 1 and Comparative Example 2, it can be seen that by adding a water-absorbing and swelling material to the formulation, the release amount per wetting cycle can be well controlled within a suitable range, avoiding a large release of the active ingredient in the early stages, thereby further extending the sustained-release cycle and effectively prolonging the weed control period. Finally, comparing the examples in Table 2 above, it can be seen that by adjusting the loading agents with different pore sizes and types, as well as the water-absorbing and swelling materials, the release amount per wetting cycle can be adjusted.

[0097] 2. Weed control cycle:

[0098] The active ingredient is 30 grams per acre. After diluting the herbicide composition with water, the solution is applied as a foliar spray at a rate of 45 liters per acre.

[0099] The test was conducted in Sanya, Hainan Province. The pesticide was applied in the evening, on a sunny day with a temperature of 30-40℃ and humidity of around 90%.

[0100] Survey methods and efficacy calculation: A weed survey was conducted before application. Five random "Z"-shaped points were selected in each plot, with each point covering 20 square meters. The types and number of weeds were recorded. A water treatment was used as a blank control. The weed control efficacy was assessed periodically after application.

[0101] Weed control efficacy (%) = (Number of weeds in the blank control area - Number of weeds in the treated area) / Number of weeds in the blank control area × 100%.

[0102] The experiment was conducted in accordance with GB / T 17980-2000 guidelines for field efficacy trials of pesticides.

[0103] Weed species included: barnyard grass, crabgrass, purslane, angelica, lambsquarters, garland chrysanthemum, potentilla, sedge, fern shoots, knotweed, bulrush, fleabane, and others. At the time of application, weed coverage in each treatment plot was 90%, with plant height ranging from 20 to 50 cm.

[0104] The weed control period was defined as the number of days following application when the herbicide efficacy began to fall below 90%. The experimental results are shown in Table 3 below.

[0105] Table 3

[0106] project Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Control period d 400 250 300 220 40 150

[0107] A comparison of Example 1 and Comparative Example 2 in Table 3 above shows that adding a water-absorbing and swelling material to the formulation can further improve the weed control cycle of the herbicide composition. A comparison of Example 1 and Comparative Example 1 in Table 3 above also shows that by vacuum calcining the loading agent and then mixing it with a liquid mixture containing the active ingredient under negative pressure, a large amount of the herbicide solution can be ensured to enter the pores of the loading agent as much as possible, rather than just being loaded on the surface of the loading agent, thus increasing the loading capacity of the loading agent and effectively extending the weed control cycle. Furthermore, a comparison of the various examples in Table 3 above shows that by adjusting the pore size and type of loading agent and the water-absorbing and swelling material, the weed control cycle can be adjusted.

[0108] Furthermore, the aforementioned herbicidal compositions are in a solid-liquid mixture state. Some active ingredients are loaded within the pores of the loading agent to achieve slow release of the active ingredients, while the majority of the active ingredients are located in the liquid. Therefore, when the herbicidal composition is applied, the active ingredients in the liquid can directly and rapidly kill weeds. Simultaneously, while the liquid components kill weeds, the loading agent is sprayed along with the liquid onto the flower centers, stems, and leaves of the plants. As the weeds wither, the loading agent accumulates at the weed roots. Because the active ingredients are inside the loading agent, their degradation is effectively delayed. Moreover, in each wet-dry cycle, with the assistance of water-absorbing and swelling materials, the effective amount of active ingredients can be released with each rainfall, acting on the weed roots and buds, effectively controlling weed germination and thus extending the weed control period.

[0109] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A controlled-release herbicidal composition, characterized in that: Based on parts by weight, it comprises 1-60 parts of active ingredient, 10-30 parts of a porous support agent, 10-20 parts of a water-absorbing and swelling material, and 40-60 parts of solvent; wherein at least a portion of the active ingredient and at least a portion of the water-absorbing and swelling material are located inside and on the surface of the support agent. The water-absorbing and swelling material is polyvinyl alcohol; The loading agent is selected from one or more of molecular sieves, silica, diatomaceous earth, and organic one-dimensional and two-dimensional mesoporous structure complexes; the pore size of the porous structure of the loading agent is one or more of micropores, mesopores, and macropores; the pore size range of the loading agent is 5 nm to 200 μm. After the loading agent is calcined under vacuum to remove the gas from the porous structure, it is mixed with other components of the controlled-release herbicidal composition, excluding the loading agent, under negative pressure to obtain the controlled-release herbicidal composition.

2. The controlled-release herbicidal composition according to claim 1, characterized in that: The active ingredients are a first active ingredient and a second active ingredient in a mass ratio of 0.01 to 100:1, wherein the first active ingredient is glufosinate and / or succinyl glufosinate, and the second active ingredient is sulfopyrazine.

3. The controlled-release herbicidal composition according to claim 1, characterized in that: At least some of the pores in the porous structure of the loading agent are blind pores.

4. The controlled-release herbicidal composition according to claim 1, characterized in that: The pore size of the loading agent ranges from 0.3 μm to 200 μm.

5. The controlled-release herbicidal composition according to claim 1, characterized in that: The vacuum degree of the vacuum calcination is 0.1~100kPa; and / or the calcination temperature of the vacuum calcination is 200~1000℃; and / or the mixing temperature is room temperature.

6. The controlled-release herbicidal composition according to claim 5, characterized in that: The vacuum degree of the vacuum calcination is 50~100kPa; and / or the calcination temperature of the vacuum calcination is 200~700℃.

7. The controlled-release herbicidal composition according to claim 6, characterized in that: The calcination temperature of the vacuum calcination is 300~500℃.

8. The controlled-release herbicidal composition according to claim 1, characterized in that: The loading amount of the loading agent is 5% to 90%.

9. The controlled-release herbicidal composition according to claim 1, characterized in that: The controlled-release herbicide composition has a weed control period of more than 200 days; and / or, the controlled-release herbicide composition releases 0.1% to 3% of the active ingredient by mass per wetting cycle.

10. The controlled-release herbicidal composition according to claim 1, characterized in that: The solvent is one or more of water, ethanol, isopropanol, NMP, and natural mineral oil.

11. The controlled-release herbicidal composition according to claim 1, characterized in that: The controlled-release herbicidal composition further includes 5-15 parts of a synergist; the controlled-release herbicidal composition further includes 1-10 parts of an anti-volatilizer; the controlled-release herbicidal composition further includes 0.1-5 parts of an odorant.

12. The controlled-release herbicidal composition according to claim 11, characterized in that: The synergistic agents include a pH adjuster, a leaf wetting agent, and a stomatal opener in a mass ratio of 1:0.05~10:0.1~50; The odorant is one or more of tetrahydrothiophene, butyl mercaptan, n-propanethiol, and dibutyl sulfide.

13. The controlled-release herbicidal composition according to claim 12, characterized in that: The pH adjuster includes one or more combinations of sodium pyrophosphate, ammonium phosphate, ammonium hydrogen phosphate, sodium borate, and sodium citrate; The leaf wetting agent includes one or more combinations of fatty acid polyoxyethylene esters, OP-type surfactants and Tween-type surfactants; The pore-opening agent includes vanillin and / or sesquiterpenoid plant growth hormones.

14. The controlled-release herbicidal composition according to claim 1, characterized in that: The controlled-release herbicide composition is formulated from the following components in parts by weight: Composition: 5-30 parts of active ingredient, 10-20 parts of loading agent, 10-20 parts of water-absorbing and swelling material, 5-15 parts of synergist, 1-10 parts of anti-volatilization agent, 0.1-5 parts of odorant, and 40-60 parts of solvent.

15. The controlled-release herbicidal composition according to claim 1, characterized in that: The controlled-release herbicidal composition is a liquid formulation, wherein at least a portion of the active ingredient is located in the liquid outside the loading agent.

16. A method for preparing a controlled-release herbicidal composition as described in any one of claims 1 to 15, characterized in that: Includes the following steps: (1) Prepare a liquid mixture by mixing all components except the loading agent; (2) The loading agent is heated and calcined under vacuum conditions, and then cooled to room temperature; (3) Under negative pressure, the liquid mixture prepared in step (1) is mixed and stirred with the loading agent cooled in step (2) to obtain a controllable release herbicidal composition.

17. A method of using a controlled-release herbicidal composition as described in any one of claims 1 to 15, characterized in that: The controlled-release herbicide composition is diluted with water and then applied by aerosol spraying.

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