KR100232030B1 - Herbicidal aqueous-based microemulsion compositions - Google Patents

Abstract

The present invention relates to water-soluble salts of N-phosphonomethylglycine as active ingredients [example; Water-insoluble herbicides mixed with isopropylamine salts [example; Fluoxyoxypyr 1-methylheptyl ester]. The composition comprises one or more amine ethoxylates comprising two moles of ethylene oxite; One or more cokeamine ethoxylate surfactants comprising 10 to 20 moles of ethylene oxide; And stable microemulsions by selecting special surfactants such as glycol ethers, c ₄ -c ₁₂ aliphatic alcohols, ethylene, propylene or butylene oxide based alcohol ethers, or one or more crude surfactants which are nonionic surfactants having an HLB value of less than 10. It is formulated as.

Description

Herbicide Aqueous Microemulsion Composition

The present invention relates to a novel oil-in-water microemulsion of herbicidal chemicals, methods of preparation thereof and the use of such compositions for controlling undesirable plant species.

In the field of agriculture, methods for cultivating corp plants have been carried out using products comprising various active ingredients to obtain a broad spectrum of control of undesirable plant species. When two or more products are applied to a crop, formulations comprising two or more active ingredients are usually mixed in a tank just prior to application in the art. Such mixtures are often referred to as tank mixtures and include two or more active ingredients, where the mixed spectrum of activity results in specific defects of each individual ingredient.

Tank mixtures suffer from the drawback that farmers have to purchase and store each herbicide separately until the tank mixture is substantially manufactured in the art. Farmers also need to measure the amount of change in each of the different herbicides used in the tank mixture, potentially making mistakes in mixing. Thus, prepackaged mixtures (ie concentrates containing mixtures of herbicides in one container) require farmers to purchase and store only one prepackaged mixture containing the active ingredients and make mistakes in mixing. It is very desirable because the possibility is eliminated. Appropriate amounts of prepackaged concentrate can be added directly to the tank used for application and diluted by the addition of water to prepare the desired mixture in situ.

However, difficulties arise in preparing prepackaged concentrates when one of the herbicides is immiscible with water or the composition comprises herbicide mixtures that are not all miscible in the same target solvent. To overcome solvent incompatibility, concentrated emulsion formulations can be used. The concentrated emulsion formulation consists of two phases and is a dispersion of one immiscible liquid (discontinuous phase) of the second liquid (continuous phase). If the continuous phase is water, the emulsion is an oil in oil-in-water form, and the water immiscible liquid or solution is generally referred to as ″ oil ″ regardless of its properties. In concentrated emulsion formulations, the active ingredient is usually dissolved in organic solvents depending on the emulsifier or dispersant added. When the concentrate is added to water, the active ingredient is evenly dispersed in water.

In addition, formulations have been developed in which unused water soluble herbicides or mixtures of these herbicides are dissolved in the oil phase and the water soluble herbicide is carried out in the aqueous phase. A water dispersible herbicidal emulsion composition comprising mono-isopropylammonium N-phosphonomethylglycine, which is a water soluble herbicide in an aqueous phase, and a water-insoluble 2-haloacetanilide herbicide in an oil phase, is described in US Pat. No. 4,440,562. The emulsifier system in such formulations is an anionic-nonionic blend comprising alkaliaryl sulfonates, phosphate esters of nonylphenol ethoxylates and polyalkylene glycol ethers.

Emulsion formulations with a particle (drop) size of generally at least 0.4y and opaque to light require a significant supply of mechanical energy in the high shear mixed form. These emulsions are dynamically stable due to the mechanical energy required to form the emulsion. To prevent the emulsion from separating into the respective phases, a gel or thickening surfactant is added.

Microemulsions, on the other hand, exist as a unique kind of thermodynamically stable liquid dispersion in which the diameter of the dispersed particles (drops) is less than 0.1 γ. Microemulsions are transparent to light and have low interfacial tension, which makes them thermodynamically stable without the necessity of applying a large amount of mechanical energy, thereby thickening and stabilizing them by forming emulsions or adding gels. In order to achieve the low interfacial tension required to form microemulsions, they are generally prepared using one or more surfactants or a mixture of surfactants and cosurfactants (eg, polar compounds with a medium chain length). Such mixtures of surfactants generally need to provide a suitable balance between hydrophilicity and lipophilic in the required oil and aqueous phases.

Microemulsions can generally be obtained by having a particular surfactant mixture and a desired concentration of such mixtures, but formulating herbicidal microemulsions is known in the art. For example, the choice of solvents and emulsifiers should be made such that the herbicides in the concentrated solution, even at low temperatures, may be emulsifiable if they are maintained and diluted in water. In preparing microemulsion formulations, herbicides that are soluble in the aqueous phase should be essentially insoluble in the organic phase. In contrast, herbicides that are soluble or suspended in organic solvents must be essentially insoluble in the aqueous phase. It is necessary to ensure that the concentrate remains physically stable over the shelf life of the concentrated product. If the water solubility should be excessive, crystal growth occurs in the concentrate, causing its physical breakup.

Further difficulty arises when preparing microemulsions where it is desirable to place the active ingredients inside both the oil and the aqueous phase. In preparing concentrated products of such mixtures, there is a need to develop a system comprising a suitable surfactant or blend of surfactants and a cosurfactant to maintain the stability of the microemulsion and to maintain the stability of the active ingredients in the two phases. There is.

The present invention relates to a water dispersible herbicidal microemulsion composition comprising the following components.

A. 1 to 30 weight percent of one or more water insoluble herbicides;

B. optionally from 0 to 25 weight percent of a water-immiscible organic solvent in which the water-insoluble herbicide is soluble;

C. 1 to 30% water soluble salts of glyphosate;

D. 0.5 to 35, preferably 0.5 to 10 weight percent of at least one aman ethoxylate surfactant comprising 2 to 5 moles of ethylene oxide;

E. 0.5 to 35, preferably 0.5 to 10 weight percent of at least one amine ethoxylate surfactant comprising 8 to 20 moles of ethylene oxide;

F. 0.5-10% by weight of one or more cosurfactants which are glycol ethers, c ₄ -c ₁₂ aliphatic alcohols, ethylene, propylene or butylene oxide based alcohol ethers, or nonionic surfactants having an HLB value of less than 10; And

G. A sufficient amount of water to act as a continuous phase for the emulsion.

As used herein, the term `` herbicide '' regulates or reversely modifies the growth of a plant because of the polytoxicity or other effect that is substantially sufficient to severely delay the growth of the plant or cause additional damage enough to kill the plant. Means the active ingredient.

The term "stability" refers to the emulsion's resistance to the coalescence of dispersed droplets.

The term ″ plants ″ refers to growing seeds, eminging seedlings, rhizomes and established vegetation.

The term ″ water insoluble ″ as used herein means that the water solubility is less than about 0.1% by weight at 25 ° C.

The active herbicidal compounds or compounds in the nonaqueous or ″ oil ″ phase of the invention are preferably water incompatible herbicides which are liquid below 30 ° C. and are generally used as herbicide carriers in amounts of 30% by weight or more at 20 ° C. Soluble in aqueous solvent. Examples of water-immiscible herbicides that are liquid below 30 ° C. are all commercially available as follows:

3,5,6-trichloro-2-pyridinyloxyacetic acid as butoxyethyl ester (trichloropyr appendecylethyl ester); (4-chloro-2- as butoxyethyl or isooctyl ester (MCPA isooctyl ester) Methylphenoxy) acetic acid;

(±) -2- (4-chloro-2-methylphenoxy) propionic acid as isooctyl ester (mecoprop isooctyl ester);

3,6-dichloropyridine-2-carboxylic acid as isooctyl ester (clopyralide isooctyl ester);

(±) -2- [4-[{5- (trifluoromethyl) -2-pyridinyl]} phenoxy] propionic acid as butyl ester (fluazifop-butyl);

(R) -2- [4-[[(5-trifluoromethyl) -2-pyridinyl] oxy] phenoxy] propionic acid as butyl ester (fluazipor-R-butyl);

(2,4-dichlorophenoxy) as 2-butoxyethyl, isooctyl or butyl ester, (2,4-D butoxyethyl ester, 2,4-D isooctyl ester and 2,4-D butyl ester) Acetic acid (2,4-D);

(±) -2- (2,4-dichlorophenoxy) propionic acid (2) as isooctyl and 2-butoxyethyl ester (2,4-DP isooctyl ester and 2,4-DP 2-butoxyethyl ester) , 4-DP); And

S-octyl O- (6-chloro-3-phenyl-4-pyridazinyl) carbamothioate (pyridate).

Preferably, the liquid water immiscible herbicide is triclopyr or an ester thereof [eg; Triclopyrbutoxyethyl ester (commercially available under the trade name CROSSBOW from Douelanco).

Examples of water-immiscible herbicides that are solid above 30 ° C. are all commercially available as follows;

1-methylheptyl ester ([4-amino-3,5-dichloro-6-fluoro-2-pyridinyl) oxy] acetic acid as fluroxypyr methylheptyl ester;

N-benzoyl-N- (3,4-dichlorophenyl) -DL-alanine ethyl ester (benzoalprop-ethyl);

2,6-dichloro-4-cyanophenyl octanoate (bromineoxyyl octanoate);

2- [1- (ethoxyimino) butyl] -3-hydroxy-5- (tetrahydro-2H-thiopyran-3-yl) -2-cyclohexan-1-one

(Cyclooxydim);

S- (2,3-dichloro-2-propenyl) bis (1-methylethyl) -carbamothioate (dialate);

(RS) -2- [4- (2,4-dichloro phenoxy) phenoxy] propanoic acid as methyl ester (dichlorophosph methyl);

(±) -2- [4-[(6-dichloro-2-benzoxazolyl) oxy] phenoxy] propanoic acid as ethyl ester (phenoxaprop ethyl);

N-benzoyl-N- (3-chloro-4-fluorophenyl) -D-alanine as methyl and isopropyl esters (flamprop-M-isopropyl and flamprop-M-methyl);

(±) -2- [4-[(3-chloro-5- (trifluoromethyl) -2-pyridinyl as methyl and ethoxy ethyl esters (haloxyphor-methyl and halooxyphosph-ethoxyethyl) ] Oxy] phenoxy] propionic acid;

2,6-diiodido-4-cyanophenyl octanoate (oxynyl octanoate);

N- (1-ethylpropyl) -3,4-dimethyl-2,6-dinitrobenzeneamine (pentimethalin) and

(±) -2- [4-[(6-chloro-2-quinoxalinoxy) phenoxy] propionic acid as ethyl ester (quizalopope-ethyl).

Preferably, the water-immiscible herbicide that is solid above 30 ° C. is fluroxypyr or a solid ester thereof. Fluoxyoxypyr is described in US Pat. No. 3,761,486 and represented by the following general formula.

Esters of fluroxypyr are described in US Pat. No. 3,755,339. Fluoxyoxypyr 1-methylheptyl ester is commercially available from Dow Elanco under the trademark STARANE. Water-insoluble herbicides [eg; Fluroxypyr or triclopyr] is present in the emulsion composition at a concentration of about 1 to about 30 weight percent, preferably about 2 to about 20 weight percent, more preferably about 2 to about 15 weight percent.

Certain organic solvents may be used in the emulsion of the present invention in which fluoxyoxy or triclopyr are soluble and nonreactive with glyphosate and are essentially water insoluble (less than 1% by weight). Suitable organic solvents are, for example, xylenes, kerosene, C ₉ aromatics, N-alkylpyrrolidines derived from naturally occurring fatty acids (eg N-octyl or N-dodecyl] esters, monoflo Robenzenes, etc., or two or more blends of such materials, etc. Organic solvents having a high flash point and low toxicity to humans are preferably used in the tanning compositions of the present invention. %, Preferably at a concentration of 5 to 20% by weight.

The water soluble herbicidal active ingredient of the present invention is zero (glyphosate) of N-phosphonomethyl glycine. Suitable salts of glyphosate are, for example, Group I and II metals having an atomic number of 30 or less, pyridine, ammonium, aniline, lower aliphatic hydrocarbon amines and lower alkanol amines, where the term ″ lower ″ Or an aliphatic radical having 4 or less carbon atoms in the straight or branched chain thereof. Preferred salts of glyphosate for use in the present invention are isopropylamine salts. The concentration of glyphosate salt present in the emulsion of the present invention is 30% by weight, preferably 10-25% by weight of the total composition. The isopropylamine salt of N-phosphonomethyl glycine is commercially available from Monsanto Company under the trademark ROUNDUP.

An emulsifier system essential for the present invention is a blend of amine-ethoxylate surfactants that produce a suitable hydrophilic: lipophilic balance (HLB) to maintain the herbicide of the present invention as an emulsion. According to the HLB system, surfactants are classified as the size and strength of the hydrophilic and lipophilic portions of the molecule. The size and strength balance of these two opposite groups is called the hydrophilic-lipophilic balance or HLB. The lipophilic emulsifier has a small HLB value, but the hydrophilic emulsifier has a large HLB value. The HLB values assigned to emulsifiers range from 1 to 40 and the midpoint is about 10. A general description of the hydrophilic lipophilic balance is given in the literature.

[Reference; L.I. Osipov, Surface Chemistry (1962).

Suitable ethoxylated amine surfactants for use in the present invention include, for example, ethoxylated primary amines derived from animal and vegetable fatty acids; Ethoxylated synthetic C ₁₂ -C ₁₈ primary, secondary or tertiary amines; Ethoxylated di- and polyamines; Polyoxy ethylenated alkylamines, quaternized polyoxyethylenated amines (eg alkylamines) and alkyldimethylamine oxides. Especially useful are ethoxylated amines, all of which have from 1 to 20 moles of ethylene oxide [eg; Oleylamine, xamine, tallow amine or hydrogenated tallow amine. The total amount of emulsifier is generally from 1 to 30% by weight, preferably from 2 to 25% by weight, more preferably from 2 to 15% by weight of the total seed. Preferred surfactant mixtures are mixtures of amine ethoxylates containing from 2 to 5 moles of ethylene oxide and cochamine ethoxylates containing from 10 to 20 moles of ethylene oxide.

Commercially available ethoxylated amines are generally mixtures of long chain ethoxy. For example, a commercially nominally 2 mole ethoxylated commercial product usually contains a small amount of product that is 1-3 moles ethoxylated. As the degree of ethoxylation increases, the ″ spread ″ of the long chain ethoxylates also increases. However, the ductility of the long chain ethoxylates in such commercial products is generally not widespread, and materials having a nominal ethoxylate content of 15 moles of ethylene oxide per molecule generally have a certain significant amount of less than 13 or 17 or more ethylene oxide units. Does not contain substances.

Ethoxylated amine surfactants used in the present invention are commercially available from a number of manufacturers in a manner as described in the literature [see; ″ McCutcheon ′s Emulsifiers and Detergents ″, North American Edition, 1989, McCutcheon Division, MC Publishing Co., 175 Rock Rd., Glen Pock, N.J. 07452, U.S.A.]

Emulsifier blends result in the production of microemulsions with a droplet size of 5 to 500 nm, preferably 5 to 250 nm and more preferably 5 to 100 nm.

The present invention also requires the presence of a cosurfactant that provides a suitable balance between hydrophilicity and lipophilic for the oil and water phase needed under the conditions of use. Suitable surfactants for use in the present invention are, for example, primary C ₄ -C ₁₂ aliphatic alcohols [eg; Butanol and nonanol; Ethylene, propylene or butylene oxide alcohol ethers [eg; 2-butoxyethanol and dipropylene glycol monomethyl ether]; And nonionic surfactants having an HLB value of less than 10. Examples of suitable nonionic surfactants are block copolymers of C ₉ -C ₁₆ alcohol ethoxylates and propylene oxide or ethylene oxide. Other suitable nonionic surfactants are alkyl phenol ethoxylates having 1 to 5 moles of ethylene oxide [eg; Nonylphenol having 1 mole of ethylene oxide]. The amount of crude surfactant of the present invention is from 0.5 to 10% by weight, preferably from 2 to 5% by weight of the total composition.

Suitable cosurfactants are dipropylene glycol methyl ethers sold under the trade name DOWANOL by The Dow Chemical Company.

In the emulsions of the present invention, water is present in varying amounts depending on the amount of other ingredients used and in an amount sufficient to act as a continuous phase for the water insoluble herbicidal ingredients.

The herbicidal emulsions of the invention, in particular when the compositions are stored for a certain prolonged period of time prior to use (especially under reverse storage conditions), may contain one or more inert formulation aids [eg; Anti-foaming agents, anti-caking agents, biocide, dyes, preservatives, freezing point depressants, and the like.

The emulsion compositions described in the present invention can be prepared using standard methods in the art. Generally, water insoluble herbicides are first dissolved in organic solvents and then combined with emulsifying surfactants. The glyphosate isopropylamine salt concentrate (trade name ROUNDUP) is then combined with a solution comprising a water insoluble herbicide under low shear. Thereafter, crude surfactant is added and then water is added to obtain the composition in the desired concentration. Thereafter, the complete mixture is blended until homogeneous. Advantageously, when using a herbicide such as fluroxypyr methylheptyl ester that is solid below 30 ° C., the herbicide is added to the organic solvent in the molten state.

Embodiments of the present invention will be described by the following examples.

Example 1

Microemulsions Including Fluuroxypyr 1-methylheptyl Esters and Glyphosate Isopropylamine Salts The following compositions are examples of formulations of the present invention.

The formulation is prepared by the following method;

A. The molten fluoxyoxy 1-methylheptyl ester is dissolved in Solvesso150 and then combined with the two surfactants, Ethomeen S-12 and c-25.

B. The solution prepared in (A) is added to the glyphosate isopropylamine concentrate. Glyphosate isopropylamine concentrate is added with 614 g of a commercially available herbicidal concentrate ROUNDUP.

C. Subsequently, Doan is added DPM to the mixture of B described above and then the water is combined to mix the complete mixture until homogeneous.

Example 1a

The chemical stability of the emulsion formulations prepared according to Example 1 at various storage temperatures is shown in Table 1A. The data in Table 1a are measured by high performance chromatography using an emulsion sample stored in glass and coated with an APEX ODS (5γ) stationary phase eluted with 65:35 acetonitrile: water. The data indicate that less than about 3% is lost after 1 month of storage at 55 ° C.

TABLE 1a

Example 1b

A training (20ppm caco ₃₎ and the dilution properties of the emulsion formulation as prepared in Example I in hard water (500ppm caco ₃₎ defined by the World Health Organization (WHO) shown in Table IB, storage for one month at various temperatures The characteristics after the removal are shown in Table 1c. Dilution tests are performed using 2% V / V dilutions in 20 and 500 ppm caco ₃ equivalents water at 20 ° C in accordance with the International Pesticide Analysis Joint Committee (CIPAC) test set MT 36.1dp.

TABLE 1b

TABLE 1c

Example 1d

The tanning formulations as prepared in Example I were stored in glass under a variety of conditions for one month and their pH change is shown in Table ID.

TABLE 1d

Example 2

Microemulsions comprising a halooxyphosph ethoxyethyl ester and glyphosate isopropylamine salt The microemulsion preparation is prepared using the following components;

The formulation is prepared by the following method. The molten halooxyphosph ethoxyethyl ester is dissolved in Solvesso 150 and then combined with two surfactants, etomine C-15 and C-25. The resulting solution is added to glyphosate isopropylamine salt concentrate. 553 g of glyphosate concentrate are added with commercially available herbicidal concentrate ROUNDUP. Thereafter, DOWANOL DPM is added to the mixture, and the finished mixture is combined until uniform.

Example 3

Microemulsion concentrate comprising triclopyr butoxyethyl ester and glyphosate as isopropylamine salt

Microemulsion compositions using the following components are used;

The formulation is prepared by the following method. Ethomin C-15 and C-25 are combined with triclopyr butoxyethyl ester. The resulting solution is added to 553 g of herbicidal concentrate ROUNDUP, commercially available. Thereafter, DOWANOL DPM is added to the mixture, followed by the addition of water to mix the finished mixture until homogeneous.

Example 4

Microemulsion concentrate comprising 2,4-D isooctyl ester and glyphosate isopropylamine salt

A microemulsion is prepared using the following ingredients.

The formulation is prepared by the following method. Ethomin C-12 and C-25 are combined with 2,4-D isooctyl ester. The resulting solution is added to 553 g of herbicidal concentrate ROUNDUP, commercially available. Thereafter, DOWANOL DPM is added to the mixture, followed by the addition of water to mix the finished mixture until homogeneous.

Sprayable herbicidal compositions formulated from the microemulsion concentrates of the present invention can be applied from any type of device currently in use that does not result in plugging of the spray nozzles or other malfunctions of the spray device. have.

The herbicidal emulsions described herein produce weed control that is comparable to conventional tank mixtures of active herbicidal components. When comparing the emulsion of Example I with a control tank mixture comprising active ingredients based on commercially available products, no significant difference in weed control was found.

As can be seen from the foregoing, a preferred embodiment of the present invention is a pre-packaged, single container mixture that can be conveniently stored and handled and has improved storage stability. A flowable herbicidal microemulsion concentrated composition comprising a water-soluble isopropylamine salt of) and a water-insoluble fluroxypyr or triclopyr ester herbicide.

Other aspects of the present invention will become apparent to those skilled in the art in view of the embodiments of the invention described herein or herein. Embodiments of the invention should be considered only as illustrative of the invention and the scope of the invention is indicated by the appended claims.

Claims (10)

A. 1 to 30 weight percent of one or more water insoluble herbicides; B. optionally from 0 to 25 weight percent of a water-immiscible organic solvent in which the water-insoluble herbicide is soluble; C. 1 to 30% water soluble salts of glyphosate; D. 0.5-35% by weight of one or more aman ethoxylate surfactants comprising 2-5 moles of ethylene oxide; E. 0.5-35% by weight of one or more amine ethoxylate surfactants comprising 8-20 moles of ethylene oxide; F. 0.5-10% by weight of one or more cosurfactants which are glycol ethers, C ₄ -C ₁₂ aliphatic alcohols, ethylene, propylene or butylene oxide based alcohol ethers, or nonionic surfactants having an HLB value of less than 10; And G. water-dispersible herbicidal microemulsion concentrated composition comprising water of sufficient aroma acting as a continuous phase with respect to the emulsion. The composition of claim 1 wherein the one or more water insoluble herbicides is one or more of fluroxypyr, triclopyr, and esters thereof. The composition of claim 2 wherein the water-insoluble herbicide is fluroxypyr 1-methylheptyl ester. The composition according to claim 1, wherein the salt of glyphosate is an isopropylamine salt. A composition according to claim 1, wherein the amount of component D is 0.5-10% by weight of the composition. The composition according to claim 1, wherein the amount of component E is 0.5 to 10% by weight of the composition. The method of claim 1, further comprising: A. 2-20% by weight of fluoroxypyr 1-methylheptyl ester; B. 5-20% by weight of a water immiscible organic solvent in which fluoroxypyr is soluble; C. 10-25 weight percent isopropylamine salt of glyphosate; D. 0.5-10% by weight of one or more amine ethoxylides comprising 2 moles of ethylene oxide; E. 0.5-10% by weight of one or more cokeamine ethoxylate surfactants comprising 10-20 moles of ethylene oxide; F. Glycol Ethers. 2-5% by weight of one or more cosurfactants which are C ₄ -C ₁₂ aliphatic alcohols, ethylene, propylene or butylene oxide based alcohol ethers, or nonionic surfactants having an HLB value of less than 10 and G. act as a continuous phase for the emulsion A composition comprising a sufficient amount of water to make. 8. A composition according to claim 7, comprising essentially 2 to 20% by weight of A. fluoroxypyr 1-methylheptyl ester; B. 5-20% by weight of a water immiscible organic solvent in which fluoroxypyr is soluble; C. 10-25 weight percent isopropylamine salt of glyphosate; D. 0.5-10% by weight of one or more amine ethoxylides comprising 2 moles of ethylene oxide; E. 0.5-10% by weight of one or more cokeamine ethoxylate surfactants comprising 10-20 moles of ethylene oxide; F. Glycol Ethers. C ₄ -C ₁₂ aliphatic alcohol, ethylene, propylene or butylene oxide alcohol ether, or a composition consisting of 2 to 5% by weight of one or more cosurfactants which are nonionic surfactants having an HLB value of less than 10. A herbicidal composition prepared by diluting the herbicidal microemulsion concentrate composition according to claim 1 with a diluent suitable for application to weeds. A method of controlling or preventing weed infestation comprising applying the composition of claim 9 to a site to be prevented from growing weeds or weeds.