CN112075436B

CN112075436B - Weeding composition, preparation and preparation method thereof

Info

Publication number: CN112075436B
Application number: CN202011020663.1A
Authority: CN
Inventors: 刘东卫; 崔雨华; 常青; 戴文赞; 葛士斌; 张全; 张婷婷; 殷青艳; 蒋广生; 祝工作
Original assignee: Jiangsu Futian Agrochemical Co ltd
Current assignee: Jiangsu Futian Agrochemical Co ltd
Priority date: 2020-09-25
Filing date: 2020-09-25
Publication date: 2022-11-15
Anticipated expiration: 2040-09-25
Also published as: CN112075436A

Abstract

The invention relates to the technical field of pesticides, and particularly relates to a weeding composition, a preparation and a preparation method thereof. A herbicidal composition comprising metamifop and clodinafop-propargyl. The invention also provides a herbicide dispersible oil suspension agent containing the composition. The herbicide composition adopts the metamifop and the clodinafop-propargyl for compounding, has low toxicity, wide herbicide controlling spectrum, quick response and good persistence, has extremely strong herbicide controlling activity on broadleaf weeds and grassy weeds, is safe to crops, overcomes the defect of single active component herbicide, reduces the application dosage, delays the drug resistance, and lightens the drug burden of farmers and the pollution to the environment. The invention also provides a herbicide dispersible oil suspending agent containing the weeding composition, the particle size is small, the oil suspending agent can be well dispersed after being emulsified and wetted, the suspension rate is high, the physical stability is good, the adhesion capability on the surface of a plant is strong, the rain wash resistance is realized, and the pesticide effect is durable.

Description

Weeding composition, preparation and preparation method thereof

Technical Field

The invention relates to the technical field of pesticides, and particularly relates to a weeding composition, a preparation and a preparation method thereof.

Background

An aryloxyphenoxypropionic Acid (APP) herbicide is one of important herbicide types for preventing and killing gramineous weeds, but after a single agent is used for a long time, the weeds generate strong drug resistance, and the weeding effect is poor. And a single agent generally only aims at one type of weeds to be prevented and removed, and if a plurality of types of weeds, such as broadleaf weeds and annual gramineous weeds, need to be prevented and removed simultaneously, two or more than two herbicides need to be sprayed simultaneously, so that the application amount is large, and the application burden of farmers is increased.

The dispersible oil suspending agent is a liquid preparation with active ingredients stably suspended in liquid incompatible with water, is diluted and prepared by water and is used by spraying weeds, and has the advantages of safety, environmental protection, good drug effect, good adhesiveness, strong spreadability, strong rain erosion resistance and the like. However, under the influence of the emulsifier, the emulsion obtained by diluting the original drug with water is not uniform, so that the concentration of active ingredients in the obtained emulsion is not uniform, the concentration of the active ingredients sprayed on the surfaces of weeds is not uniform, so that the active ingredients on the surfaces of some weeds are too low to kill, and the expected weeding effect cannot be achieved in the actual use. The method is particularly urgent for better exerting the control effect of the active ingredients of the pesticide, particularly the dispersible oil suspending agent is not ideal as a new formulation, and the existing dispersible oil suspending agent has the defects of poor emulsifying dispersibility, serious layering, easy thickening or bottom forming.

Aiming at the technical problems, the invention provides a weeding composition and a herbicide dispersible oil suspension agent prepared from the weeding composition, which not only have better emulsion dispersibility and stability, but also overcome the defect of single active component herbicide, realize the prevention and control of broadleaf weeds and annual gramineous weeds, simultaneously reduce the application dosage, and reduce the medication burden of farmers and the pollution to the environment.

Disclosure of Invention

In order to solve the above technical problems, a first aspect of the present invention provides a herbicidal composition comprising metamifop and clodinafop-propargyl.

As a preferred embodiment of the present invention, the weight ratio of metamifop to clodinafop-propargyl is 100:1-1:100.

in a preferred embodiment of the present invention, the formulation of the herbicidal composition is at least one selected from the group consisting of oil suspension, aqueous suspension, emulsifiable concentrate, aqueous emulsion, microemulsion, concentrated emulsion, microcapsule, wettable powder, soluble powder, water dispersible granule, and effervescent tablet.

The second aspect of the present invention provides a herbicide dispersible oil suspension concentrate comprising the herbicidal composition, wherein the herbicide dispersible oil suspension concentrate is prepared from the following raw materials, by weight: 5-35% of weeding composition, 5-15% of emulsifier, 5-20% of dispersant, 1-5% of wetting agent, 1-5% of thickening agent and the balance of dispersion medium to 100%.

As a preferred embodiment of the present invention, the emulsifier is selected from hydrophilic emulsifiers having an HLB value of 3-6 and/or lipophilic emulsifiers having an HLB value of 9-12.

In a preferred embodiment of the present invention, the emulsifier is a mixture of polyoxyethylene sorbitan trioleate and sorbitan monooleate, and the weight ratio of the polyoxyethylene sorbitan trioleate to the sorbitan monooleate is (1-5): 1.

in a preferred embodiment of the present invention, the dispersant is at least one selected from the group consisting of alkylphenol ethoxylate formaldehyde condensate, lignosulfonate, polycarboxylate, naphthalene sulfonate formaldehyde condensate, p-methoxyfatty amido benzenesulfonic acid, and alkylphenol ethoxylate phosphate.

As a preferred embodiment of the invention, the dispersant is a mixture of a polycarboxylate and a naphthalene sulphonate formaldehyde polycondensate in a weight ratio of 1: (0.5-1.5).

As a preferred embodiment of the present invention, the dispersion medium includes at least methyl oleate.

The third aspect of the present invention provides a preparation method of the herbicide dispersible oil suspension concentrate, comprising the steps of:

(1) Mixing the dispersion medium, the emulsifier, the dispersant and the wetting agent, and stirring uniformly;

(2) Adding the weeding composition and the thickening agent, and shearing for 10-40 minutes at the rotating speed of 1000-10000 rpm; then the mixture is put into a sand mill and ground until the grain diameter D90 is less than 8 mu m, thus obtaining the product.

Advantageous effects

The invention provides a weeding composition, which is prepared by compounding metamifop and clodinafop-propargyl, has low toxicity, wide weeding spectrum, quick action and good persistence, has extremely strong weeding activity on broadleaf weeds and gramineous weeds, is safe to crops, overcomes the defect of a herbicide containing a single active component, reduces the application dosage, delays the drug resistance, and reduces the drug burden of farmers and the pollution to the environment. The invention also provides a herbicide dispersible oil suspending agent containing the weeding composition, the particle size is small, the oil suspending agent can be well dispersed after being emulsified and wetted, the suspension rate is high, and the physical stability is good; the plant disinfectant can be directly prepared into spray liquid for use, has strong adhesion capability on the surface of a plant, is rain-wash resistant, and has lasting drug effect; the preparation method is simple, no dust pollution is caused in the production process, flammable and explosive organic solvents are not used, the production method is safe for producers, users and environment, the storage and the transportation are convenient and safe, and the processing and the packaging cost is low.

Detailed Description

The disclosure may be understood more readily by reference to the following detailed description of preferred embodiments of the invention and the examples included therein. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control.

The term "prepared from …" as used herein is synonymous with "comprising". The terms "comprises," "comprising," "includes," "including," "has," "having," "contains," "containing," or any other variation thereof, as used herein, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

The conjunction "consisting of …" excludes any unspecified elements, steps or components. If used in a claim, this phrase shall render the claim closed except for the materials described except for those materials normally associated therewith. When the phrase "consisting of …" appears in a clause of the subject of the claims rather than immediately after the subject matter, it defines only the elements described in that clause; no other elements are excluded from the claims as a whole.

When an amount, concentration, or other value or parameter is expressed as a range, preferred range, or range defined by a list of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted to include the ranges "1 to 4", "1 to 3", "1 to 2 and 4 to 5", "1 to 3 and 5", and the like. When a range of values is described herein, unless otherwise stated, the range is intended to include the endpoints thereof and all integers and fractions within the range.

The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. "optional" or "either" means that the subsequently described event or events may or may not occur, and that the description includes instances where the event occurs and instances where it does not.

Approximating language, as used herein throughout the specification and claims, is intended to modify a quantity, such that the invention is not limited to the specific quantity, but includes portions that are literally received for modification without substantial change in the basic function to which the invention is related. Accordingly, the use of "about" to modify a numerical value means that the invention is not limited to the precise value. In some instances, the approximating language may correspond to the precision of an instrument for measuring the value. In the present description and claims, range limitations may be combined and/or interchanged, including all sub-ranges contained therein if not otherwise stated.

In a first aspect of the present invention there is provided a herbicidal composition comprising metamifop and clodinafop-propargyl.

In a preferred embodiment, the weight ratio of metamifop to clodinafop-propargyl is 100:1-1:100.

in a more preferred embodiment, the weight ratio of metamifop to clodinafop-propargyl is 1: (0.1-10).

The inventor finds that the timeliness and the weeding effect of the herbicide can be remarkably improved by compounding the metamifop and the clodinafop-propargyl, and the weeding effect on grassy and broadleaf weeds is particularly optimal. The inventors believe that the possible reason is that fatty acids have important physiological roles in the plant body, being the basic structural components of triglycerides, which are the main energy-storing and-supplying substances, and the phospholipids converted from them are also constituents of cell membranes, and fatty acids can also be converted into metabolic hormone-like substances, of which acetyl-coa carboxylase (ACCase) is a key enzyme in fatty acid biosynthesis. The molecular structures of the metamifop and the clodinafop-propargyl both have active group F atoms, and the molecular structures also contain ester groups, so that the metamifop and the clodinafop-propargyl are easier to absorb by weeds. The effective components are absorbed by leaves and leaf sheaths of plants, transmitted by phloem, accumulated in meristems of plants, can inhibit biosynthesis of lipid into acetyl-coenzyme A hydroxylase inhibitor, inhibit acetyl-coenzyme A carboxylase (ACCase), stop fatty acid synthesis, and hinder processes of further synthesizing fatty acid, so that the processes of forming oleic acid, linoleic acid, linolenic acid, a wax layer and a cuticle are hindered, thus cell growth and division can not be normally carried out, a membrane structure is rapidly destroyed, permeability is enhanced, and finally plant death is caused. The inventor finds in the process of experiments that if only a single agent is used, the weeding range has certain limitation, and the weeds are easy to generate drug resistance, so that the weeding effect is poor. By compounding the metamifop and the clodinafop-propargyl, the defect and limitation of the single-dose application are made up, especially the major harm of the clodinafop-propargyl to crops is relieved, the herbicidal spectrum can be enlarged, the herbicidal effect is improved, the pesticide application optimum period is widened, the phytotoxicity is reduced, the occurrence and development of the drug resistance of the herbicide are delayed, the problem of low control effect of the single clodinafop-propargyl on Poa pratensis is solved, the excellent herbicidal effect on broadleaf and gramineous weeds is shown, and especially the best removal effect on annual gramineous weeds is achieved. The inventor also unexpectedly finds that clodinafop-propargyl is quickly degraded into free acid phenyl and pyridine parts in soil to enter the soil and mineralize, metamifop has low toxicity and environment-friendly effect, and after the two agents are compounded, the using dosage of pesticide is reduced, and the adverse effect of the pesticide on the ecological environment is reduced.

The inventor also unexpectedly found that the weight ratio of metamifop to clodinafop-propargyl in the invention is not higher than 1:1, the weeding composition is suitable for removing annual weeds, particularly grassy weeds, and has the best removal effect; with the continuous increase of the amount of clodinafop-propargyl, the weeding spectrum of the clodinafop-propargyl is gradually increased, so that the clodinafop-propargyl can be used for removing perennial malignant weeds and deepening the phytotoxicity degree of the clodinafop-propargyl on crops. Thus, the amount of clodinafop-propargyl in the formulation cannot exceed 35%.

In the invention, the dosage form of the weeding composition is at least one selected from oil suspending agent, water suspending agent, missible oil, aqueous emulsion, microemulsion, concentrated emulsion, microcapsule, wettable powder, soluble powder, water dispersible granule, granule and effervescent tablet.

The inventor finds that the metamifop and clodinafop-propargyl adopted by the invention are solid pesticides, and the lipophilicity, the membrane permeability, the anti-metabolic stability, the volatility, the thermal stability and the chemical stability of the compound are increased due to the introduction of fluorine atoms, so that the biological activity of the compound can be improved, and the resistance of organisms to the compound is difficult to generate. The structures of the metamifop and the clodinafop-propargyl contain fluorine atoms, so that the lipophilicity of the active ingredient is greatly enhanced. If the aqueous suspension agent is processed into an aqueous suspension agent, when the aqueous suspension agent is diluted by water and sprayed on a target, particularly on rice leaf surfaces, the aqueous suspension agent is difficult to wet and spread due to large surface tension and poor adhesiveness, and is easy to roll off, so that the pesticide effect is reduced. The metamifop and the clodinafop-propargyl are systemic conduction herbicides, and the use of the oil can quickly help the active ingredients to conduct and penetrate through the epidermis of crops to enter the interior of the plants, so that the permeability, the adhesiveness and the absorption capacity of the active ingredients are improved, and the aim of improving the pesticide effect is fulfilled.

In a more preferred embodiment, the herbicide dispersible oil suspension comprises the following components in percentage by weight: 24% of weeding composition, 10% of emulsifier, 8% of dispersant, 2% of wetting agent, 3% of thickening agent and the balance of dispersion medium to 100%.

Emulsifier

In the present invention, the emulsifier is a nonionic emulsifier, and there is no particular limitation, and a hydrophilic emulsifier and a lipophilic emulsifier can be mentioned.

As the hydrophilic emulsifier, there may be mentioned polyoxyethylene sorbitan monooleate, polyoxypropylene stearate, polyoxyethylene lanolin alcohol ester, sorbitan laurate, polyoxyethylene fatty acid, polyoxyethylene oxypropylene oleate, polyoxyethylene sorbitol beeswax derivative, tetraethylene glycol mono-and silicate ester, polyoxyethylene lauryl ether, polyoxyethylene sorbitan monostearate, hexaethylene glycol monostearate, polyoxyethylene lanolin alcohol ether, polyoxyethylene cetyl ether, polyoxyethylene sorbitan tristearate, polyoxyethylene lauryl ether, polyoxyethylene sorbitan trioleate, polyoxyethylene oxypropylene oleate, polyoxyethylene lanolin derivative, polyoxyethylene monooleate, polyoxyethylene monostearate, polyoxyethylene monooleate, polyoxyethylene monostearate, polyoxyethylene monopalmitate, alkylaryl sulfonate, triethanolamine oleate, polyoxyethylene oleic ether, polyoxyethylene monolaurate, polyoxyethylene alkylphenol, polyoxyethylene acetylated lanolin derivative, polyoxyethylene alkylaryl sorbitan ether, polyoxyethylene monolaurate, polyoxyethylene lauryl ether, polyoxyethylene castor oil, polyoxyethylene vegetable oil, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monostearate and the like.

As the lipophilic emulsifier, there may be mentioned propylene glycol fatty acid ester, propylene glycol monostearate, sorbitan sesquioleate, polyethylene sorbitol, glyceryl monostearate, polyoxyethylene sorbitol beeswax derivative, propylene glycol fatty acid ester, sorbitan monooleate, propylene glycol laurate, propylene glycol monolaurate, propylene glycol fatty acid ester, sorbitan monostearate, diethylene glycol monooleate, diethylene glycol monostearate, diethylene glycol fatty acid ester, polyoxyethylene oleyl ether, polyoxyethylene sorbitol beeswax derivative, ethylene glycol fatty acid ester, glyceryl monostearate, diethylene glycol fatty acid ester, tetraethylene glycol monostearate, tetraethylene glycol monooleate, and the like.

In a preferred embodiment, the emulsifier is selected from hydrophilic emulsifiers having an HLB value of from 3 to 6 and/or lipophilic emulsifiers having an HLB value of from 9 to 12.

In a preferred embodiment, the emulsifier is a mixture of polyoxyethylene sorbitan trioleate and sorbitan monooleate in a weight ratio of (1-5): 1.

in a more preferred embodiment, the emulsifier is a mixture of polyoxyethylene sorbitan trioleate and sorbitan monooleate in a weight ratio of 3:1.

the inventor finds that the dispersible oil suspending agent takes oil as a dispersing medium, the density of the oil is lower than that of water, and if the oil is directly dropped into the water, the oil can float on the water surface and seriously affect the dispersion of the agent in the water, thereby affecting the weeding effect, so whether an oily preparation can be fully emulsified to form a good secondary dispersing system when the oily preparation is used for water or not can remarkably affect the weeding effect of the dispersible oil suspending agent. The inventor finds that the compounding of polyoxyethylene sorbitan trioleate and sorbitan monooleate can play a role in synergy, so that after the prepared dispersible oil suspending agent is diluted by water, oil drops are not easy to form on the surface of an emulsion, the emulsion with uniform texture can be formed, and therefore when weeds are sprayed, active ingredients of pesticides on the surfaces of the weeds are uniformly attached to the surfaces of stems and leaves of the weeds, and the weeding effect is improved. The inventor believes that the possible reasons are that the interfacial tension of the micro-droplets of the dispersible oil suspending agent is greatly reduced after the dispersible oil suspending agent is diluted by water, the volume of the droplets formed by scattering in the water is small, the dispersion suspension property is good, and the obtained emulsion is uniform in texture and stable; because the compound emulsifier of the polyoxyethylene sorbitan trioleate and the sorbitan monooleate contains ester structures, the emulsifier has better affinity with the original medicines of the metamifop and the clodinafop-propargyl, the molecules are crosslinked through chemical bonds, the small-molecular original medicine is firmly wrapped in the emulsifier, meanwhile, a plurality of long chains of the polyoxyethylene sorbitan trioleate are entangled into a net structure, a layer of water film is formed on the surface of the original medicine, the fixing effect is achieved, the distribution uniformity and stability of the effective components in the emulsion are improved, the clotted and separated-out and settled clodinafop-propargyl in water are prevented, and particularly under the low-temperature condition, the dispersibility, the suspension property and the stability of the effective components are obviously improved. Because the concentration of the effective components is an important factor for the control effect of the weeds, the compound emulsifier is adopted, so that the concentration of the effective components sprayed on the stems and leaves of the weeds is uniform, and the insecticidal effect can be improved. The inventor also unexpectedly finds that the compounding of the polyoxyethylene sorbitan trioleate and the sorbitan monooleate can improve the adhesion, wetting, spreading, permeation and other properties of the liquid medicine on the plant leaf surfaces.

Dispersing agent

In the invention, the dispersant is at least one selected from alkylphenol polyoxyethylene ether formaldehyde condensate, lignosulfonate, polycarboxylate, naphthalenesulfonate formaldehyde condensate, p-methoxy fatty amido benzene sulfonic acid and alkylphenol polyoxyethylene ether phosphate.

In a preferred embodiment, the dispersant is a mixture of a polycarboxylate and a naphthalene sulfonate formaldehyde polycondensate in a weight ratio of 1: (0.5-1.5).

In a more preferred embodiment, the weight ratio of the polycarboxylate and naphthalene sulfonate formaldehyde polycondensate is 1:0.8.

in a most preferred embodiment, the polycarboxylate has a comb-like structure; the naphthalene sulfonate formaldehyde polycondensate is a modified naphthalene sulfonate formaldehyde polycondensate.

In the invention, the polycarboxylate can be obtained from Beijing broad-source agricultural chemical company with the models of GY-D800, GY-D900, GY-D600, GY-D04, GY-D06, GY-D08 and the like; GY-D800 and GY-D900 are preferred.

In the present invention, as the source of the naphthalene sulfonate formaldehyde polycondensate, there may be mentioned Beijing Guangyuan Yinong chemical LLC, model GY-D10, NDS and the like.

In the invention, the weight ratio of the emulsifier to the dispersant is 1: (0.3-1.5).

In a preferred embodiment, the weight ratio of emulsifier to dispersant is 1:0.8.

in order to ensure the long-term stable uniform dispersion of solid original drug particles in an oil dispersion medium and prevent the problems of flocculation, large particle size, storage caking and the like of a sample. The inventor finds that the dispersibility and stability of the dispersible oil suspending agent in an oil dispersion medium can be remarkably improved by compounding the polycarboxylate dispersing agent and the naphthalenesulfonate formaldehyde polycondensate. The inventor thinks that the possible reason is that the surface of the original drug particles has a hydrophobic structure, while the polycarboxylate dispersing agent adopted by the invention has an amphiphilic structure, so that the polycarboxylate dispersing agent can be adsorbed on the surface of the original drug particles, reduce the interfacial free energy of the original drug particles and weaken the merging tendency among the pesticide particles, and on the other hand, an electric double layer is formed on the surface of the original drug particles through self ionization, and the dispersed original drug particles are stably dispersed in an oily dispersing medium by virtue of the steric hindrance formed by the electric double layer and the macromolecules; when the dispersible oil suspending agent is diluted by water, a conjugated system in naphthalene rings of the modified naphthalene sulfonate formaldehyde polycondensate has strong deformability, is very easy to adsorb on the surfaces of pesticide particles, and hydrophilic groups of the dispersible oil suspending agent can easily form hydrogen bonds with water to generate association, so that a stable water film is formed on the surfaces of the pesticide particles, the fluidity and the suspensibility of pesticide particles are obviously improved, and the dispersible oil suspending agent has good salt resistance, hard water resistance and thermal stability. After the polycarboxylate dispersant and the naphthalenesulfonate formaldehyde polycondensate are compounded for use, the original drug molecules have good stability in an oily dispersion medium and water. In the test process, the inventor finds that when the dosage of the dispersing agent is less than 5%, the dispersing agent does not reach saturated adsorption on the surface of original drug particles, pesticide particles cannot be fully coated by dispersing agent molecules, and the particles are agglomerated and settled under the action of van der waals acting force and gravity field, so that the viscosity of the preparation is increased. When the amount of the dispersant is about 5%, the viscosity is reduced to a value range which is relatively small and suitable for pourability. When the amount of the dispersant is further increased to more than 10%, the excessive dispersant molecules in the suspension are entangled with the coating layer on the surface of the active ingredient particles, causing bridging between the particles, resulting in flocculation, resulting in an increase in the viscosity of the formulation. Meanwhile, in the sanding process, the compounding of the polycarboxylate and the naphthalenesulfonate formaldehyde polycondensate has the obvious viscosity reducing effect and improves the sanding efficiency. In addition, the inventors have surprisingly found that the compounding of a comb-like polycarboxylate structure with a naphthalene sulphonate formaldehyde polycondensate can also effectively alleviate the problems of oil bleeding and hot-storage viscous creaming of dispersible oil suspensions. The inventor thinks that the invention selects the emulsifier with ester group, which has better compatibility with the oily dispersion medium, and the polyoxyethylene sorbitan trioleate has four long-chain structures, which can be entangled with the comb-shaped polycarboxylate to form a network structure, thus improving the stability of the system and keeping the rheological property; in particular, the naphthalene sulfonate formaldehyde condensate can be adsorbed on the surface of a raw pesticide, the steric hindrance of molecules is increased, and the migration, aggregation and sedimentation of the raw pesticide molecules are inhibited under the synergistic charge effect.

Thickening agent

In the present invention, the thickener is not particularly limited.

In a preferred embodiment, the thickener is selected from bentonite, white carbon, silica, xanthan gum, attapulgite, anti-settling thixotropic agents and the like.

In a preferred embodiment, the thickener is a mixture of bentonite and silica.

In a more preferred embodiment, the weight ratio of bentonite to white carbon black is 1: (0.05-0.4).

In a most preferred embodiment, the weight ratio of bentonite to white carbon black is 1:0.2.

the inventor believes that the addition of the thickener in the present invention increases the viscosity of the suspension system, and maintains the stability of the dispersion system by adsorbing the dispersion medium with the thickener. However, as the temperature increases, the dispersion medium adsorbed in the thickener is released, resulting in the occurrence of oil bleeding. In the invention, by compounding the bentonite and the white carbon black, and the methyl oleate contained in the dispersion medium, the problem of oil separation of the dispersible oil suspending agent under high temperature conditions can be better solved. The inventor believes that the possible reason is that the bentonite can absorb oil in methyl oleate to expand to form a network gel structure, so that a large amount of oily dispersion medium molecules are wrapped in network gaps, and the viscosity of the system is increased. However, as the shear rate increases, the structure is broken, and a large amount of the encapsulated oily dispersion medium is released again, thereby exhibiting a shear-thinned state. However, a certain amount of white carbon black is added, and the white carbon black can form a three-dimensional structure after oil absorption and expansion, so that the overlapping and covering opportunities of organic carbon chains of bentonite are increased, the structural damage resistance is increased, the yield value of a system is increased, and the oil separation rate of the dispersible oil suspending agent in the normal temperature and heat storage states is reduced; meanwhile, as the carbon chains of the bentonite are mutually overlapped to form a network structure, the structure can support pesticide particles and enable the pesticide particles to be well suspended in a dispersion system.

Dispersion medium

In the present invention, the dispersion medium is not particularly limited.

In a preferred embodiment, the dispersion medium comprises at least methyl oleate.

In a more preferred embodiment, the amount of methyl oleate present in the dispersion medium is from 20 to 60% by weight.

In a more preferred embodiment, the amount of methyl oleate present in the dispersion medium is 40% by weight.

In a preferred embodiment, vegetable light oil, rosin oil, palm oil, mineral oil, fatty acid methyl ester, and the like can also be mentioned as the dispersion medium.

According to the invention, the addition of the methyl oleate not only can be used for coordinating with the thickener, reducing the oil bleeding phenomenon of the dispersible oil suspending agent, and improving the suspension rate of the effective components; meanwhile, the inventor also finds that the dispersing agent used by the invention, namely polyoxyethylene sorbitan trioleate and sorbitan monooleate, has poor compatibility and dispersibility, and the problem can be well solved by adding methyl oleate.

A second aspect of the present invention provides a method for preparing the herbicide dispersible oil suspension, comprising the steps of:

(1) Mixing the dispersion medium, emulsifier, dispersant and wetting agent, and stirring;

(2) Adding the weeding composition and the thickening agent, and shearing for 10-40 minutes at the rotating speed of 1000-10000 rpm; and then the mixture is put into a sand mill and ground until the particle size D90 is less than 8 mu m, thus obtaining the product.

The particle size measuring method comprises the following steps:

1. laser particle size method: and (3) measuring the average particle size Dav of the suspension sample by using a laser particle size analyzer, wherein the sample introduction is carried out for 3 times during the particle size measurement, the measurement is repeated for 3 times each time, and the average value is taken.

2. A microscopic method: accurately taking 1mL of dispersible oil suspending agent by using an injector, dripping the dispersible oil suspending agent into a beaker, adding methyl oleate for diluting by 250 times, coating the mixture on a glass slide, observing under a microscope, and taking a picture, recording and analyzing.

The present invention will be specifically described below by way of examples. It is to be noted that the following examples are given solely for the purpose of illustration and are not to be construed as limitations on the scope of the invention, as many insubstantial modifications and variations of the invention described above will now occur to those skilled in the art.

In addition, the starting materials used are all commercially available, unless otherwise specified.

Examples

Example 1

Example 1 provides a herbicide dispersible oil suspension agent, which is prepared from the following raw materials in percentage by weight: 24% of weeding composition, 10% of emulsifier, 8% of dispersant, 2% of wetting agent, 3% of thickening agent and the balance of dispersion medium to 100%.

The weeding composition comprises metamifop and clodinafop-propargyl in a weight ratio of 1:4; the emulsifier is a mixture of polyoxyethylene sorbitan trioleate and sorbitan monooleate, and the weight ratio of the polyoxyethylene sorbitan trioleate to the sorbitan monooleate is 3:1; the dispersant is a mixture of polycarboxylate and naphthalene sulfonate formaldehyde polycondensate, and the weight ratio of the polycarboxylate to the naphthalene sulfonate formaldehyde polycondensate is 1:0.8; the thickening agent is a combination of bentonite and white carbon black, and the weight ratio is 1:0.2; the dispersion medium is a combination of methyl oleate and soybean oil, and the weight ratio is 2:3.

the preparation method of the herbicide dispersible oil suspending agent comprises the following steps:

(2) Adding the weeding composition and the thickening agent, and shearing for 30 minutes at the rotating speed of 8000 revolutions per minute; and then the mixture is put into a sand mill and ground until the particle size D90 is less than 8 mu m, thus obtaining the product.

Example 2

Embodiment 2 provides a herbicide dispersible oil suspension agent, which comprises the following raw materials in percentage by weight: 5% of weeding composition, 5% of emulsifier, 5% of dispersant, 1% of wetting agent, 1% of thickening agent and the balance of dispersion medium to 100%.

The weeding composition comprises metamifop and clodinafop-propargyl in a weight ratio of 10:1; the emulsifier is a mixture of polyoxyethylene sorbitan trioleate and sorbitan monooleate, and the weight ratio of the polyoxyethylene sorbitan trioleate to the sorbitan monooleate is 1:0.5; the dispersant is a mixture of polycarboxylate and naphthalene sulfonate formaldehyde polycondensate, and the weight ratio of the polycarboxylate to the naphthalene sulfonate formaldehyde polycondensate is 1:0.8; the thickening agent is a combination of bentonite and white carbon black, and the weight ratio is 1:0.05; the dispersion medium is a combination of methyl oleate and soybean oil, and the weight ratio is 1:4.

Example 3

Example 3 provides a herbicide dispersible oil suspension agent, which is prepared from the following raw materials in percentage by weight: 35% of weeding composition, 15% of emulsifier, 20% of dispersant, 5% of wetting agent, 5% of thickener and dispersion medium, wherein the total amount is 100%.

The weeding composition comprises metamifop and clodinafop-propargyl in a weight ratio of 1:10; the emulsifier is a mixture of polyoxyethylene sorbitan trioleate and sorbitan monooleate, and the weight ratio of the polyoxyethylene sorbitan trioleate to the sorbitan monooleate is 5:1; the dispersant is a mixture of polycarboxylate and naphthalene sulfonate formaldehyde polycondensate, and the weight ratio of the polycarboxylate to the naphthalene sulfonate formaldehyde polycondensate is 1:1.5; the thickening agent is a combination of bentonite and white carbon black, and the weight ratio is 1:0.4 of the total weight of the mixture; the dispersion medium is a combination of methyl oleate and soybean oil, and the weight ratio is 3:2.

Example 4

Example 4 differs from example 1 in that the sorbitan monooleate is replaced by sorbitan tristearate; the HLB value of the sorbitan monooleate is 4.3; the HLB value of the sorbitan tristearate is 1.8.

Example 5

Example 5 differs from example 1 in that the polyoxyethylene sorbitan trioleate is replaced by polyoxyethylene sorbitan monolaurate; the HLB value of the polyoxyethylene sorbitan trioleate is 11; the HLB value of the polyoxyethylene sorbitan monolaurate is 13.3.

Example 6

Example 6 differs from example 1 in that the sorbitan monooleate is replaced with calcium dodecylbenzene sulfonate.

Example 7

Example 7 differs from example 1 in that the dispersant is a polycarboxylate.

Example 8

Example 8 differs from example 1 in that the dispersant is a naphthalene sulfonate formaldehyde condensate.

Example 9

Example 9 differs from example 1 in that the thickener is bentonite.

Example 10

Example 10 differs from example 1 in that the thickener is xanthan gum.

Example 11

Example 11 differs from example 1 in that the dispersion medium is soybean oil.

Performance testing

1. Determination of the suspension Rate

The test of the suspension rate can refer to HG/T2467.5-2003. Accurately weighing 1.0 + -0.02 g (m) ₁ ) The oil suspension dispersible sample prepared in example was poured into a stoppered measuring cylinder containing 250mL of standard hard water, and the stoppered measuring cylinder was closed and inverted 30 times (1 time of up-down 180 ℃). The measuring cylinder with the plug is placed in a constant-temperature water bath device with the temperature of 25 +/-1 ℃ and is not fluctuated, timing is started, the measuring cylinder is taken out of a water bath kettle after 30min, 225mL (namely 9/10) of solution at the upper layer is slowly pumped out by using a micro vacuum pump, the measuring cylinder is not shaken in the process, the tail end of a suction pipe is kept to be attached to the liquid level as far as possible, and the phenomenon that the latex pipe stretches into the measuring cylinder too long to suck out sediment at the bottom of the measuring cylinder is avoided, so that the accuracy of a test result is influenced. The remaining 25mL of sample at the bottom of the cylinder was transferred to a weighed clean petri dish, and the mass of the clean petri dish was recorded (m) ₂ ) Placing the culture dish containing the solution in a drying oven at 74 +/-1 ℃ to dry to constant weight, and weighing the mass (m) of the dried culture dish ₃ ) The mean was taken 3 times. The suspension ratio W (%) is calculated as follows: w = [1- (m) ₃ -m ₂ )/m1]X 9/10 x 100%; wherein m is ₁ Is the mass, m, of the sample ₂ Mass m of the culture dish before drying ₃ The mass of the dried culture dish.

2. Measurement of oil bleeding Rate

And (3) centrifuging 5mL of the dispersible oil suspending agent prepared in the embodiment for 30min at 3000r/min, taking out, observing and recording the oil separation and precipitation conditions, and calculating the oil separation rate according to the ratio of the oil separation volume to the total volume.

3. Stability determination

1. And (3) testing the heat storage stability:

sucking 10g of the dispersible oil suspending agent prepared in the embodiment by using a suction pipe, injecting the oil suspending agent into a clean ampoule bottle, sealing the ampoule bottle at high temperature, putting the ampoule bottle into a constant-temperature (54 +/-2 ℃) incubator, carrying out hot storage for 14 days, taking out the ampoule bottle, respectively detecting various indexes of the dispersible oil suspending agent, such as suspension rate, viscosity and the like, and if the indexes before and after the hot storage reach the national standard, carrying out the hot storage for 2 years.

2. Cold storage stability test:

sucking 80mL of the dispersible oil suspending agent prepared in the embodiment by using a suction pipe, placing the dispersible oil suspending agent in a 100mL beaker, refrigerating the dispersible oil suspending agent in a refrigerator (0 +/-2 ℃), placing the beaker for one hour, stirring the beaker once every 15 minutes, wherein the stirring time is 15s each time, observing the change of the appearance, continuously placing the beaker in the refrigerator for 7 days, taking out the beaker after 7 days, placing the beaker to room temperature, respectively detecting various indexes such as the suspension rate, the viscosity and the like of the dispersible oil suspending agent, and if the indexes before and after cold storage reach the national standard, judging that the cold storage is qualified, and storing the sample at normal temperature for 2 years.

Test results are shown in table 1.

TABLE 1 results of the Performance test of dispersible oil suspensions obtained in examples 1 to 11

The foregoing examples are merely illustrative and serve to explain some of the features of the method of the present invention. The appended claims are intended to claim as broad a scope as is contemplated, and the examples presented herein are merely illustrative of selected implementations in accordance with all possible combinations of examples. Accordingly, it is applicants' intention that the appended claims are not to be limited by the choice of examples illustrating features of the invention. Where the claims recite a range of values, such ranges are intended to include all sub-ranges subsumed therein, and variations within the ranges are intended to be encompassed by the claims as appended hereto where possible.

Claims

1. The herbicide is characterized in that the herbicide is a dispersible oil suspending agent, and the raw materials for preparing the dispersible oil suspending agent comprise the following components in percentage by weight: 24% of herbicide composition, 10% of emulsifier, 8% of dispersant, 2% of wetting agent, 3% of thickener and dispersion medium, wherein the total amount is 100%;

the herbicide composition is metamifop and clodinafop-propargyl; the weight ratio of the metamifop to the clodinafop-propargyl is 1:4;

the emulsifier is selected from hydrophilic emulsifier with HLB value of 3-6 and/or lipophilic emulsifier with HLB value of 9-12;

the emulsifier is a mixture of polyoxyethylene sorbitan trioleate and sorbitan monooleate, and the weight ratio of the polyoxyethylene sorbitan trioleate to the sorbitan monooleate is 3:1;

the dispersant is a mixture of polycarboxylate and naphthalene sulfonate formaldehyde polycondensate, and the weight ratio of the polycarboxylate to the naphthalene sulfonate formaldehyde polycondensate is 1:0.8;

the thickening agent is a combination of bentonite and white carbon black, and the weight ratio is 1:0.2;

the dispersion medium is a combination of methyl oleate and soybean oil, and the weight ratio is 2:3.

2. a process for the preparation of a herbicide as claimed in claim 1, characterized in that it comprises the following steps:

(2) Adding herbicide and thickener, and shearing at 1000-10000 rpm for 10-40 min; and then the mixture is put into a sand mill and ground until the particle size D90 is less than 8 mu m, thus obtaining the product.