FIELD OF THE INVENTION

[0001] The invention relates to an herbicide formulation comprising an Acetyl-CoA carboxylase (ACC) inhibitor and its process of preparation thereof and also to its use for controlling undesired vegetation.

BACKGROUND AND THE PRIOR ART
[0002] Herbicides acting as Acetyl-CoA carboxylase (ACCase) inhibitors are known to control undesired vegetation such as grasses (graminids). The ACCase inhibitors were first introduced in 1978 and are widely used to control grass species. There are three chemical groups of ACCase inhibitors, Aryloxyphenoxypropionates (APP), Cylcohexanediones (CHD), and Phenylpyrazolines (PPZ). APPs are is an important class of herbicides due to their high efficiency, broad spectrum, low toxicity and good selectivity. Some of the known APP herbicides are clodinafop-propargyl, cyhalofop-butyl, diclofop-methyl, diclofop-P-methyl, fenoxaprop-P-ethyl, fluazifop-butyl, fluazifop-P-butyl, haloxyfop, haloxyfop-P, haloxyfop-P-methyl, propaquizafop, quizalofop, quizalofop-ethyl, quizalofop-P, quizalofop-P-ethyl and quizalofop-P-tefuryl.

[0003] The APP herbicide, such as clodinafop-propargyl is employed as post-emergence grass herbicide (graminicide). Clodinafop-propargyl is 2-Propynyl-(2R)-2-[4-[(5-chlor-3-fluor-2-pyridinyl)oxy]phenoxy]propanoate which is an ester of 2-(4-(3-Chloro-5-fluoro-2-pyridyloxy)-phenoxy-propionic acid. It is a systemic herbicide that acts on post-emergent weeds such as wild oats, rough meadow-grass, green foxtail, barnyard grass, persian darnel and volunteer canary seed. Clodinafop-propargyl possesses herbicidal activity against grassy weeds in winter cereals especially in wheat and barley as well as pulses. Clodinafop-propargyl interacts with and inhibits the Acetyl-CoA carboxylase, which is essential for the production of lipids or fatty acids needed for plant growth. The selectivity of this herbicide is based on the difference in the speed of herbicide breakdown in the crop versus the weeds. Clodinafop-propargyl converts from the ester form to the active acid and then to biologically inactive compounds.

[0004] Clodinafop-propargyl herbicide is available in various types of formulations e.g. Wettable Powder (WP), Emulsion Concentrates (EC), Microemulsion (ME), or Oil Dispersion (OD).

[0005] Clodinafop-propargyl alone or in combination is preferred in the form of wettable powder and emulsion concentrates as it has some advantages such as a higher degree of systemicity and higher overall activity compared to the same pesticide formulated in various other forms.

[0006] A wettable powder is a solid formulation consisting of the active ingredient in a finely ground state combined with surface active compounds that ensure easy wettability with water. Wettable powders are designed to be applied as a dilute suspension through liquid spraying equipment. As wettable powders are not mixed with water until immediately before use, storing and transporting the products may be simplified as the weight and volume of the water is avoided.

[0007] One of the drawbacks of using clodinafop-propargyl WP is that they pose an inhalation hazard to the applicator while pouring and mixing the concentrated powder. Also, they require adequate and constant agitation (usually mechanical) in the spray tank and quickly settle out if agitation is turned off. They are abrasive to many pumps and nozzles and screens; and their residues may be visible.

[0008] An emulsion concentrate is a liquid formulation. The Emulsion Concentrate (EC) is a solution of the agrochemicals, solvents and surfactants that when diluted with water forms an emulsion which can be sprayed onto crops. The EC is preferred for agrochemicals which are usually water insoluble. Such concentrates are easy to store and transport. Also, it is easy to add various adjuvants in order to increase the efficacy of the formulation. Typical solvents for conventional EC formulations are aromatic hydrocarbons. These solvents have very low solubilities in water and a high capability of dissolving a wide range of active ingredients.

[0009] Stability of the EC formulations is important as it often emerges as a key challenge during development (lab to factory) as well as commercial distribution (factory to consumers). The stability is one of the important factors in determining the efficacy of liquid formulation. The liquid based formulations may undergo both physical and chemical changes depending upon the environment they are exposed to. The common problem associated with liquid formulations (E.g. EC) are creaming or sedimentation that occurs when less dense oil droplets rise to the top and a fatty cream appears; flocculation, when the internal phase droplets stick to each other forming small clumps (flocci); coalescence when internal phase droplets merge to ever larger droplets until the oil and water phase are completely separated.

[0010] Adjuvants play a major role in determining the properties of a formulation as well as in enhancing the activity of the active ingredients. The adjuvants in formulation affect various parameters such as stability, solubility, compatibility, foam, suspension, spreadability, penetration etc. With the large number of formulation options available (solutions, emulsions, wettable powders, flowables, granules, and encapsulated materials), adjuvants become even more important in assuring consistent performance. Adjuvants, such as oil adjuvants can be added directly to an agricultural formulation, such as an EC, to provide improved performance of the product upon application. It is also known that the application and action of the oil adjuvants improved significantly when combined with surface-active substances such as non-ionic, anionic or cationic surfactants.

[0011] U. S. Patent Application US20150189877 discloses an EC formulation of ACC inhibitors, preferably clodinafop-propargyl. The disclosed EC formulation expressed synergistic effect on the activity of co-applied herbicides. The EC formulation according to the invention has good miscibility, tank mix compatibility and good stability of the spray liquors over a wide concentration range. The formulations so obtained is said to be bio efficacious in controlling weeds.

[0012] E.P. Pat No. 1684583 discloses liquid formulations of ACCase inhibitors as an emulsifiable concentrates. The E.P. Pat No. 1684583 provides a stable EC comprising an herbicide, preferably clodinafop-propargyl, quinoline derivative safener, water-immiscible solvent, an oil adjuvant and a surfactant system. The optimum chemical stability of the composition has been achieved in this invention only when water component is kept below 3% and pH of the formulation is maintained between 4.5 and 8.

[0013] WO2012177832 discloses EC formulation of aryloxyphenoxypropionic acid, preferably cyhalofop-butyl and non-petroleum derived built-in adjuvant. It was found here that the weight ratio of the active ingredient to the non-petroleum derived built-in adjuvant provides the herbicidal efficacy to the composition.

[0014] Although good results are already being obtained for stable EC formulation of clodinafop-propargyl earlier but still there is a need to provide low temperature stable EC formulation for clodinafop-propargyl. Hitherto, no attempts have been made to solve the low temperature stability of clodinafop-propargyl EC formulation. The Low temperature stability becomes the prime importance for EC formulations when they need to be used or exposed in colder regions. Precipitation of actives or freezing of the EC formulations at low temperature climatic regions will lead to practical difficulties in handling the products and will result in poor bio-efficacy. The stability, particularly low temperature stability has been of great concern when Emulsion Concentrates (EC) is exposed to various changing weather conditions. In view of the above facts, there is a need for EC formulations; in particular, formulations stable at low temperature, especially at sub-zero temperatures, while maintaining the bio-efficacy of the formulations.

OBJECTS OF THE PRESENT INVENTION

[0015] It is an object of the present invention to provide an herbicide formulation which is stable at low temperature.

[0016] Another object of the present invention is to provide a process of obtaining an herbicide formulation which is stable at low temperature.

[0017] Yet another object of the invention is to obtain an herbicide formulation which is bio-efficacious.

SUMMARY OF THE INVENTION

[0018] The present invention provides an herbicide formulation comprising
a) at least one herbicidal active ingredient from the aryloxyphenoxypropionates;
b) one or more solvents;
c) one or more surfactants from the group polyethylene glycol ester of C8-C22 fatty acid;
d) one or more anionic surfactant; and
f) one or more adjuvant selected from oils of vegetable or animal origin or their derivatives;

[0019] Further, there is provided a process for preparation of an herbicide formulation, where the above mentioned components are mixed with each other according to the present invention.

[0020] Further, there is provided a method of controlling undesired vegetation, where an effective amount of the herbicide formulation according to the invention is applied to the undesired plants where they occur.

DETAILED DESCRIPTION OF THE INVENTION

[0021] In accordance with the present invention, there is provided arylphenoxypropionates herbicide as an active ingredient substantially formulated as liquid herbicide formulation stable at low temperature.

[0022] It has been found by the present inventors, surprisingly, that the problem of low temperature stability of liquid herbicide formulation of arylphenoxypropionates herbicide can be overcome by using combination of polyethylene glycol ester of C8-C22 fatty acid, anionic surfactants, solvents and adjuvants.

[0023] In an embodiment, the present invention provides the herbicide formulation comprising:
a) at least one herbicidal active ingredient from the aryloxyphenoxypropionates;
b) one or more solvents;
c) one or more surfactants from the group of polyethylene glycol ester of C8-C22 fatty acid;
d) one or more anionic surfactant;
e) one or more adjuvant selected from oils of vegetable or animal origin or their derivatives;
f) optionally one or more additional herbicide; and
g) optionally one or more other adjuvant.

[0024] In a preferred embodiment, the present invention provides an herbicide formulation comprising
a) at least one herbicidal active ingredient from the aryloxyphenoxypropionates;
b) one or more solvents;
c) one or more surfactants from the group of polyethylene glycol ester of C8-C22 fatty acid;
d) one or more anionic surfactant; and
e) one or more adjuvant selected from oils of vegetable or animal origin or their derivatives.

[0025] The preferred features described herein below should be interpreted such that the preferences apply either independently of one another or in combination with each other.

[0026] According to an embodiment of the present invention, low temperature refers to temperature below 10 °C, preferably it is below 5 °C and more preferably it is 0 °C and below 0 °C.

[0027] According to another embodiment of the present invention, the herbicide formulation comprises at least one herbicidally active substance from the class of the aryloxyphenoxypropionate, such as clodinafop-propargyl, cyhalofop-butyl, and haloxyfop p-methyl.

[0028] According to another embodiment of the present invention, the preferred aryloxyphenoxypropionate is clodinafop-propargyl.

[0029] According to another embodiment of the present invention, the herbicide formulation comprises from about 0.1% to about 50% and preferably from about 1% to about 30% of aryloxyphenoxypropionate of the total weight of the herbicide formulation.

[0030] In a preferred embodiment of the present invention, aryloxyphenoxypropionate comprises from about 2% to about 20% of the total weight of the herbicide formulation.

[0031] In another embodiment of the present invention, the herbicide formulation comprises one or more solvents.
[0032] According to another embodiment of the present invention, the solvents may be selected from one or more aromatic hydrocarbons, or mixtures thereof.

According to another embodiment of the present invention, the solvent may be selected from one or more aromatic hydrocarbons such as benzene, toluene, xylene, C9 aromatic hydrocarbon, mineral oil or kerosene or substituted naphthalenes, mixtures of mono- and polyalkylated aromatics which are commercially available under the registered trademarks Solvesso® and Shellsol® and Petrol Spezial®, or aromatic solvents from the Caromax™ series (Petrochem earless) such as Caromax™ 20, 26, 28 and Caromax™ LN 20, LN 26, LN 28; halogenated aromatic hydrocarbons such as chlorobenzene, chloro-toluenes or chloro-xylenes and mixtures thereof.

In a preferred embodiment of the present invention, the aromatic hydrocarbon solvent is selected from xylene, toluene and C9 aromatic hydrocarbon.
[0033] According to another embodiment of the present invention, the herbicide formulation comprises from about 10% to about 90% and preferably from about 15% to about 80% of solvents of the total weight of the herbicide formulation.

[0034] In a preferred embodiment of the present invention, solvents comprises from about 20% to about 70% of the total weight of the herbicide formulation.

[0035] In another embodiment of the present invention, the herbicide formulation comprises of one or more surfactants selected from polyethylene glycol ester of C8-C22 fatty acids; preferably polyethylene glycol triglyceride of C8-C22 fatty acid.

[0036] In another embodiment of the present invention, the fatty acid components of polyethylene glycol ester of C8-C22 fatty acid include lauric acid, myristic acid, stearic acid, palmitic acid, oleic acid, ricinoleic acid, linoleic acid, linoleic acid, linolenic acid, dihydroxystearic acid and mixture thereof.

[0037] According to another embodiment of the present invention, polyethylene glycol ester of C8-C22 fatty acids which contains alkylene oxide unit that ranges from 1-80, preferable 1-60.

[0038] Examples of polyethylene glycol ester of C8-C22 fatty acids include: ethoxylated vegetable oil such as soybean oil, sunflower oil, linseed oil, rapeseed oil, castor oil, canola oil, RBD canola oil and mustard oil.

[0039] According to another embodiment of the present invention, the preferred surfactants selected from polyethylene glycol ester of C8-C22 fatty acid is ethoxylated castor oil.

[0040] In an embodiment of the present invention, the herbicide formulation comprises from about 1% to 30% by weight of polyethylene glycol ester of C8-C22 fatty acid, preferably it is from about 2% to about 25 % of aromatic hydrocarbon solvents of the total weight of the herbicide formulation.

[0041] In a preferred embodiment of the present invention, polyethylene glycol ester of C8-C22 fatty acid comprises from about 3% to about 20% of the total weight of the herbicide formulation.

[0042] In an embodiment of the present invention, the herbicide formulation comprises one or more anionic surfactants.

[0043] Examples of anionic surfactants include: anionic derivatives of fatty alcohols having 10-24 carbon atoms in the form of ether carboxylates, sulphonates, sulfates, and phosphates; derivatives of alkyl aryl phenols such as tristyrylphenol phosphates and sulphates; and linear alkyl benzene sulphonate and derivatives of dicarboxylic acid in the form of dicarboxylic ester sulfonate such as alkyl sulfosuccinate.

[0044] According to another embodiment of the present invention, the preferred anionic surfactant is selected from calcium alkyl benzene sulfonate, ethoxylated tristyrylphenol sulfate, ethoxylated tristyrylphenol phosphate and alkyl sulfosuccinate.

[0045] According to another embodiment of the present invention, the herbicide formulation comprises from about 0.1% to about 30% and preferably from about 0.5% to about 25% of anionic surfactant of the total weight of the herbicide formulation.

[0046] In a preferred embodiment of the present invention, the anionic surfactant comprises from about 1% to about 20% of the total weight of the herbicide formulation.

[0047] In an embodiment of the present invention, the herbicide formulation comprises one or more adjuvant selected from oils of vegetable or animal origin or their derivatives.

[0048] Examples of adjuvants include: oils of vegetable origin and its derivatives such as, for example, soyabean oil, linseed oil, rapeseed oil, canola oil, olive oil or sunflower oil, emulsified vegetable oil, biodiesel waste (glycol), corn oil and its concentrates, the lower alkyl derivatives of lauric acid, myristic acid, stearic acid, palmitic acid, oleic acid, ricinoleic acid, linoleic acid, linolenic acid, dihydroxystearic acid, or an oil of animal origin such as fish oil or beef tallow.

[0049] According to another embodiment of the present invention, the preferred adjuvants are lower alkyl derivatives of soyabean oil.

[0050] According to another embodiment of the present invention, the herbicide formulation comprises from about 0.1% to about 90% and preferably from about 0.5% to about 85% of adjuvant of the total weight of the herbicide formulation.

[0051] In a preferred embodiment of the present invention, adjuvant comprises from about 2% to about 80% of the total weight of the herbicide formulation.

[0052] According to another embodiment of the present invention, the herbicide formulation further comprises one or more herbicides.

[0053] According to another embodiment of the present invention, the herbicide formulation further comprises one or more herbicide selected from 2,4-D, 2,4-DB, 2,4-DP, acetochlor, acifluorfen, alachlor, ametryn, amitrole, asulam, atrazine, benerin, bensulfuron, bensulide, bentazon, bromacil, bromoxynil, butachlor, butylate, chlorimuron, chlorimuron-ethyl, chlorsulfuron, cinmethylin, Clethodim, clomazone, clopyralid, clopyrasulfuron, cyanazine, cycloate, DCPA, desmedipham, dicamba, dichlobenil, diethatyl, difenzoquat, dimethachlor, diquat, dithiopyr, diuron, DSMA, endothall, EPTC, ethalfluralin, ethametsulfuron, ethofumesate, flumetsulam, fluometuron, fluridone, fluroxypyr, fomesafen, forchlorfenuron, glufosinate, glyphosate, halosulfuron, hexazinone, imazamethabenz, imazapyr, imazaquin, imazethapyr, imazmethapyr, ioxynil, isopropalin, isoxaben, lactofen, linuron, losamine, MCPA, MCPB, MCPP, metazachlor, metolachlor, metribuzin, metsulfuron, metsulfuron-methyl, molinate, MSMA, napropamide, naptalam, nicosulfuron, norflurazon, oryzalin, oxadiazon, oxyfluorfen, paclobutrazol, paraquat, pebulate, pendimethalin, phenmedipham, picloram, pretilachlor, primisulfuron, prodiamine, prometryne, pronamide, propachlor, propardi, prosulfuron, pyrazasulfuron, pyrazon, pyridate, quinclorac, rimsulfuron, sethoxydim, siduron, simazine, sulfometuron, tebuthiuron, terbacil, thiazopyr, thidiazuron, thifensulfuron, thiobencarb, triallate, triasulfuron, tribehuron, triclopyr, trifluralin, triflusulfuron, vernolat.

[0054] According to another embodiment of the present invention, the herbicide formulation further comprises one or more herbicide, preferably selected from oxyfluorfen, acifluorfen, fomesafen and metribuzin.

[0055] In an embodiment of the present invention, the herbicide formulation further comprises one or more performance enhancers such as non-ionic surfactants, humectants, antifoams, colorants, stickers or binders.

[0056] Examples of non-ionic surfactants are: fatty alcohols having 10-24 carbon atoms with 0-20 EO; fatty acid alkoxylates and triglyceride alkoxylates; fatty acid amide alkoxylates; alkylene oxide adducts of alkynediols; alkyl aryl ethoxylate such as tristyrylphenol ethoxylates; polyglycerides and derivatives thereof; preferably alcohol ethoxylate or ethoxylated castor oil.

[0057] Examples of suitable humectants are glycerol or sugar syrups, such as corn syrup, which is obtained from maize.

[0058] Suitable antifoams are, preferably, silicones, long-chain alcohols and salts of fatty acids.

[0059] Suitable colorants (for example in red, blue and green) are, preferably, pigments, which are sparingly soluble in water, and dyes. Examples are inorganic coloring agents (for example iron oxide, titanium oxide, and iron hexacyanoferrate) and organic coloring agents (for example alizarin, azo and phthalocyanin coloring agents).

[0060] Suitable stickers or binders are, preferably, polyvinylpyrrolidones, polyvinyl acetates, polyvinyl alcohols, polyacrylates, biological or synthetic waxes and cellulose ethers.

[0061] In an embodiment of the present invention, the herbicide formulation further comprises one or more additional pesticide active ingredients, plant growth regulators or safeners that are added to the emulsifiable herbicide concentrate of the present invention. These pesticide active ingredients, plant growth regulators and safeners may include one or more herbicide, a plant growth regulator and an herbicide safener. The additional pesticide active ingredients may be soluble, partially soluble or insoluble in the emulsifiable concentrate of the present invention.

[0062] In an embodiment of the present invention, the herbicide formulation further comprises one or more plant growth regulators or safeners that are added to the emulsifiable herbicide concentrate of the present invention.

[0063] In an embodiment of the present invention, the herbicide formulation further comprises one or more safeners selected from 1,8-naphthalic anhydride (NA), dichlormid, furilazole, AD-67, benoxaxor, cyometrinil, oxabetrinil, fluxofenim, flurazole, MG-191, fenclorim, dymron, dimepiperate, cloquintocet-mexyl, fenchlorazole-ethyl, mefenpyr-diethyl, isoxadifen-ethyl and cypro-sulfamide.

[0064] It is preferred to prepare the herbicide formulation according to the invention as Emulsifiable Concentrate (EC).

[0065] According to an embodiment of the present invention, there is provided an herbicide formulation comprising clodinafop-propargyl, ethoxylated castor oil, calcium dodecyl benzene sulfonate, C9 aromatic hydrocarbon and linseed oil methyl ester.

[0066] According to another embodiment of the present invention, there is provided an herbicide formulation comprising from about 0.1% to about 50% by weight of clodinafop-propargyl, from about 1% to about 30% by weight of ethoxylated castor oil, from about 0.1% to about 30% by weight of calcium dodecyl benzene sulfonate, from about 10% to about 80% by weight of C9 aromatic hydrocarbon and from about 2% to about by 80% weight of linseed oil.

[0067] According to another embodiment of the present invention, there is provided an herbicide formulation comprising clodinafop-propargyl, ethoxylated castor oil, calcium dodecyl benzene sulfonate, mix-xylene and soyabean oil methyl ester.

[0068] According to another embodiment of the present invention, there is provided an herbicide formulation comprising from about 0.1% to about 50% by weight of clodinafop-propargyl, from about 1% to about 50% by weight of ethoxylated castor oil, from about 0.1% to about 30% by weight of calcium dodecyl benzene sulfonate, from about 10% to about 80% by weight of mix-xylene and from about 1% to about 50% weight of soyabean oil methyl ester.

[0069] In an embodiment of the present invention there is provided a process for preparation of the herbicide formulation comprising
• adding active ingredient in the formulation vessel followed by addition of suitable quantity of solvent and an adjuvant;
• mixing the ingredients together until active ingredient dissolves completely to obtain a mixture;
• optionally dissolving second herbicide separately in a solvent to obtain a solution and adding solution of second herbicide in a mixture to obtain a blend;
• adding suitable quantity of surfactant from the group polyethylene glycol ester of C8-C22 fatty acid and anionic surfactant to said blend and mixing it upto 30 min until the resultant blend is homogenized with uniformly dispersed phase droplets to obtain an EC; and
• optionally adding other auxiliaries such as non-ionic surfactants, solvents or solubilizers, penetrants, protective colloids, stickers, thickeners, humectants, compatibilizers, bactericides, antifreeze agents, antifoams, colorants, adhesive and binders and mixing it upto 30 min until the resultant blend is homogenized with uniformly dispersed phase droplets to obtain the EC.

[0070] In another embodiment, the invention is liquid herbicide formulations which is stable at low temperature and demonstrate excellent stability and is bio efficacious.

[0071] In another embodiment, the invention provides a method of controlling undesired vegetation, where an effective amount of an herbicide formulation according to the invention is applied to the undesired plants where they occur.

[0072] In another embodiment, the herbicide formulation of the invention has a selective herbicidal action and may be used for the control of grassy weeds like Cynodone dectylone, Echinochloa colonum, Elusine indica, Dactyloctenium aegyptium, Dinebra arabica, Erogrostis sp Phalaris minor, Avena fatua, Poa annoa and Sorghum helpens in post emergence weed control of various dicot crops viz. soybean, cotton, groundnut , pulses (green gram, black gram, bengal gram, pigeon pea), mustard; vegetables like okra, tomato, cabbage, brinjal, chilli, carrot, onion; plantation crops like tea, grape, coffee, coconut; spices like cumin, coriander and fennel.

[0073] The reason to develop said herbicide formulation in the form of an emulsifiable concentrate (EC) is that it is needed for agrochemicals which are usually water insoluble. Such concentrates are easy to store and transport and various adjuvants may be added to increase the efficacy of the formulation. A good EC, however, requires that a stable emulsion be formed upon dilution with water, which emulsion does not separate upon standing.

[0074] Inventors of the present invention succeeded in inventing the stable formulation by careful combination of the aryloxyphenoxypropionates, emulsifiers and suitable solvents. The optimum concentration of the adjuvants as well as solvents which led to the stable EC formulation has been arrived at by the experiments as exemplified below.
EXAMPLES:
Example 1: Clodinafop-propargyl 12.5% w/w EC was prepared as follows:
Ingredients
Percentage (w/w)
Clodinafop-propargyl 12.5
Calcium dodecyl benzene sulphonate 3.0
Ethoxylated castor oil 14.0
Mix-xylene 43.5
Soyabean oil methyl ester 27.0
Total 100

[0075] Clodinafop-propargyl and mix-xylene were added in the formulation vessel and mixed together until clodinafop-propargyl dissolved completely to obtain a mixture. Then the required quantity of calcium dodecyl benzene sulphonate, ethoxylated castor oil and soyabean oil methyl ester was added to the mixture and mixed upto 30 min until the resultant blend was homogenized with uniformly dispersed phase droplets to obtain an emulsion concentrate.

[0076] The formulation obtained was clear and no phase separation was observed at 54°C, 25°C and 0°C after 7 days as per CIPAC guidelines, indicating that the formulation was stable. Sub-zero stability test has been done by keeping samples at -5°C for 7 days.
Ingredients
Percentage (w/w)
Clodinafop-propargyl 12.5
Calcium dodecyl benzene sulphonate 7.5
Ethoxylated castor oil 7.5
C9 aromatic hydrocarbon 42.5
Soyabean oil methyl ester 30.0
Total 100
Example 2: Clodinafop-propargyl 12.5% w/w EC was prepared as follows:

[0077] Clodinafop-propargyl 12.5% w/w EC including calcium dodecyl benzene sulphonate, ethoxylated castor oil, C9 aromatic hydrocarbon and soyabean oil methyl ester in a given ratio shown above was prepared as per the process of Example 1.
Example 3: Cyhalofop-butyl 12.5% w/w EC was prepared as follows:
Ingredients
Percentage (w/w)
Cyhalofop-butyl 12.5
Aerosol OT-100 5.0
Ethoxylated castor oil 12.0
Mix-xylene 45.5
Linseed oil methyl ester 25.0
Total 100

[0078] Cyhalofop-butyl 12.5% w/w EC including aerosol OT-100, ethoxylated castor oil, mix-xylene, linseed oil methyl ester in a given ratio shown above was prepared as per the process of Example 1.

[0079] Examples 1-3 of the present invention were prepared using aryloxyphenoxypropionates such as clodinafop-propargyl and cyhalofop-butyl and solvents, surfactants as well as adjuvants at varied concentrations and ratio. In examples 1-3 clodinafop-propargyl when mixed with solvents such as C9 aromatic hydrocarbon and mix xylene; surfactants such as polyethylene glycol ester of C8-C22 fatty acid; and anionic surfactants such as calcium dodecyl benzene sulfonate, ethoxylated tristyryl phenol phosphate and alkyl sulfosuccinate resulted into the clear and stable EC formulation without phase-separation, flocculation or crystallization. Similarly, cyhalofop-butyl when mixed with mix-xylene, alkyl sulfosuccinate, ethoxylated castor oil and linseed oil methyl ester resulted into stable EC formulation.
Example 4: Comparison example wherein Clodinafop-propargyl 12.5% w/w EC is prepared according to WO2012177832 as follows:
Ingredients
Percentage (w/w)
Clodinafop-propargyl 12.5
Calcium dodecyl benzene sulfonate 3.0
Ethoxylated castor oil 14.0
Soyabean oil methyl ester 70.5
Total 100

[0080] Here, the inventors of the present invention prepared the EC formulation of clodinafop-propargyl according to WO2012177832. Clodinafop-propargyl 12.5% w/w EC was prepared by adding calcium dodecyl benzene sulfonate, ethoxylated castor oil, and soyabean oil in a given ratio shown above as per the process disclosed in WO2012177832. The resultant EC formulation of clodinafop-propargyl became solidified when kept at low-temperature thereby not suitable for further intended use.

Example 5: Clodinafop-propargyl 12.5% w/w EC was prepared as follows:
Ingredients
Percentage (w/w)
Clodinafop propargyl 12.5
Calcium alkyl benzene sulphonate 5.0
Ethoxylated castor oil 12.0
Mix-xylene 45.5
Rapeseed oil methyl ester 25.0
Total 100

[0081] Clodinafop-propargyl 12.5% w/w EC including calcium alkyl benzene sulphonate, ethoxylated castor oil, mix-xylene, rapeseed oil methyl ester in a given ratio shown above was prepared as per the process of Example 1.
Example 6: Haloxyfop p-methyl 12.5% w/w EC was prepared as follows:
Ingredients
Percentage (w/w)
Haloxyfop p-methyl 12.5
Calcium alkyl benzene sulphonate 4.5
Ethoxylated castor oil 12.5
Mix-xylene 45.5
Soyabean oil methyl ester 25.0
Total 100

[0082] Haloxyfop p-methyl 12.5% w/w EC including calcium alkyl benzene sulphonate, ethoxylated castor oil, mix-xylene, soyabean oil methyl ester in a given ratio shown above was prepared as per the process of Example 1.
Example 7: Clodinafop-propargyl 46.29% w/w EC was prepared as follows:
Ingredients
Percentage (w/w)
Clodinafop-propargyl 46.29
Ethoxylated tristryl phenol phosphate -
Ethoxylated castor oil -
MSO 53.71
Total 100

[0083] Clodinafop-propargyl 46.29% w/w EC was prepared by adding soyabean oil methyl ester in a given ratio shown above was prepared as per the process of Example 1.

Example 8: Clodinafop-propargyl 28.73% w/w EC was prepared as follows:
Ingredients
Percentage (w/w)
Clodinafop-propargyl 28.73
Ethoxylated tristryl phenol phosphate -
Ethoxylated castor oil -
Mix-xylene 71.27
Total 100

[0084] Clodinafop-propargyl 28.73% w/w EC was prepared by adding mix-xylene in a given ratio shown above was prepared as per the process of Example 1.
[0085] Examples 7-8 of the present invention were prepared using clodinafop-propargyl, solvents and adjuvants. In Example 7 clodinafop-propargyl when mixed with solvents such as soyabean oil methyl ester resulted into a failed preparation that solidified at sub-zero temperature. Similarly, when clodinafop-propargyl mixed with mix xylene as shown in Example 8 also resulted into failed preparation that solidified at sub-zero temperature. With this observation, inventors have found out that a mixture of C9 aromatic hydrocarbon and soyabean oil methyl ester in combination is essential to impart cold temperature stability to the clodinafop-propargyl EC formulation.

Example 9: Clodinafop-propargyl 12.5% w/w + Oxyfluorfen 15.0% w/w EC was prepared as follows

Ingredients Amount (w/w, %)
clodinafop-propargyl 12.5
Oxyfluorfen 15.0
C9 aromatic hydrocarbon 31.5
Cyclohexanone 20
Soyabean oil methyl ester 5
Calcium alkyl benzene sulphonate 3
Ethoxylated Polyarylphenol 13

[0086] EC formulation of clodinafop-propargyl and oxyfluorfen was prepared as per the process of Example 1.

Example 10: Clodinafop-propargyl 15.5% w/w + Oxyfluorfen 14.5% w/w EC was prepared as follows

Ingredients Amount (w/w, %)
clodinafop-propargyl 15.5
Oxyfluorfen 14.5
C9 aromatic hydrocarbon 26.5
Cyclohexanone 25
Linseed oil methyl ester 2.5
Calcium alkyl benzene sulphonate 2
Ethoxylated Polyarylphenol 14

[0087] EC formulation of clodinafop-propargyl and oxyfluorfen was prepared as per the process of Example 1.

[0088] Table 1 below discloses some more formulations which can be prepared according to the present invention.

Table 1
Formulation no. Example 11 Example 12 Example 13 Example 14 Example 15
Clodinafop-propargyl 8.0 10.0 16.0 24 30
Solvent (%) 64.5 55.0 60.0
41.5 35
Anionic Surfactant: Surfactant (%) 2.0 2.0 3.0 3 5
Polyethylene glycol ester of C8-C22 fatty acid 5.0 7.5 5.0 14 20
Other Adjuvant (%) 20.5 25.5 16.0 7.5 10

Tests for storage stability, solubility and emulsifiability
[0089] The EC formulation according to the present invention was tested for storage stability, solubility and emulsifiability. The EC formulation according to the present invention was tested for stability as per CIPAC MT 39.3 at different temperature. Observations of samples for 25°C, 0°C and -5°C after 7 days has been summarised in below Table 2:

Table 2
Formulation Example no. Appearance at 25°C after 7 days Appearance at 0°C after 7 days Appearance at -5°C after 7 days
Example 1 clear clear clear
Example 2 clear clear clear
Example 3 clear clear clear
Example 4
WO2012177832 clear solidified solidified
Example 5 clear clear clear
Example 6 clear clear clear
Example 7 clear Failed Failed
Example 8 clear Failed Failed
Example 9 clear clear clear
Example 10 clear clear clear

Emulsion Stability
The emulsion stability of the formulations according to the present invention was tested after 24 hrs of dilution at 30±2°C as per CIPAC MT 36.1 and the results are summarised below in Table-3.

Table 3
Formulation Emulsion stability on dilution
Cream formation or sedimentation after 24 hrs
Example 1 creaming = 2 ml
Sediment = Nil
Example 2 creaming = 2 ml
Sediment = Nil
Example 3 creaming = 2 ml
Sediment = Nil
Example 5 creaming = 2 ml
Sediment = Nil
Example 6 creaming = 2 ml
Sediment = Nil
Example 9 creaming = 2 ml
Sediment = Nil
Example 10 creaming = 2 ml
Sediment = Nil

[0090] Examples 1-3, 5-6 and 9 -10 as shown in the table-2 were tested for stability of the formulation at different temperatures after 7 days. It was found that all these formulation resulted into stable emulsion concentrate at 25°C, 0°C and -5°C. A clear and stable EC formulation was obtained without any phase separation for all the samples over all temperatures after 7 days. This indicates that the combination of solvents and surfactants imparted excellent low temperature stability to said EC formulation of aryloxyphenoxypropionates. Example-4 was prepared according to WO2012177832 that discloses EC formulation of aryloxyphenoxypropionic acid. The formulation was prepared using clodinafop-propargyl according to the process disclosed in WO2012177832. Said formulation upon storage at cold temperatures started to solidify at 0°C and below temperatures. Further, examples 1-3, 5-6 and 9-10 were tested for emulsion stability and it was found that all the four formulations found to be stable without any sedimentation when kept under observation for 24 hours (results summarised in table-3).

Stability of the active ingredient
[0091] The formulation prepared according to the present invention was investigated for degradation of active ingredient as well as its effect on emulsion stability. The sample prepared according to Example-1 was observed for stability by keeping at 54±2°C for upto 28 days (AHS as per CIPAC MT 46.3) and the results are summarized in Table 4.
Table 4
Physico/chemical property
0 day 14 days AHS 28 days AHS
% Clodinafop propargyl
12.51 12.13 12.11
pH 1% aqueous emulsion
4.35 4.29 4.25

[0092] As shown in Table 4, degradation of active clodinafop-propargyl in EC formulation was not observed when kept at of 54±2°C for 28 days. It was also found that the pH of the EC formulation did not change over the period of 28 days. This signifies that the EC formulation of clodinafop-propargyl so obtained has an excellent stability. The combination of adjuvants according to the present invention leads to the stable formulation which does not undergo any chemical and physical changes on storage at low temperatures and is also easy to handle for further use.

[0093] Therefore the herbicide formulation of clodinafop-propargyl as emulsifiable concentrate prepared according to the present invention exhibited good low temperature stability. The instant invention is more specifically explained by above example. However, it should be understood that the scope of the present invention is not limited by the examples in any manner. It will be appreciated by any person skilled in this art that the present invention includes aforesaid examples and further can be modified and altered within the technical scope of the present invention.
,CLAIMS:1. A herbicide formulation comprising:
a) at least one herbicidal active ingredient from the aryloxyphenoxypropionates;
b) one or more solvents;
c) one or more surfactants from the group polyethylene glycol ester of C8-C22 fatty acid;
d) one or more anionic surfactants; and
f) one or more adjuvants selected from oils of vegetable or animal origin or their derivatives.

2. The herbicide formulation as claimed in claim 1 wherein, said aryloxyphenoxypropionate is selected from clodinafop-propargyl, cyhalofop-butyl and haloxyfop-p-methyl.

3. The herbicide formulation as claimed in claim 1 wherein, said aryloxyphenoxypropionate is clodinafop-propargyl.

4. The herbicide formulation as claimed in claim 1 wherein, said formulation comprises from about 0.1% to about 50% of aryloxyphenoxypropionates of the total weight of the herbicide formulation.

5. The herbicide formulation as claimed in claim 1 wherein, said solvent is selected from aromatic hydrocarbons or mixtures thereof.

6. The herbicide formulation as claimed in claim 1 wherein, said herbicide formulation comprises from about 10% to about 90% of solvent of the total weight of the formulation.

7. The herbicide formulation as claimed in claim 1 wherein, said surfactant from the group of polyethylene glycol ester of C8-C22 fatty acids is selected from ethoxylated vegetable oil such as soybean oil, sunflower oil, linseed oil, rapeseed oil, castor oil, canola oil, canola oil and mustard oil.

8. The herbicide formulation as claimed in claim 1 wherein, said herbicide formulation comprises from about 1% to 30% by weight of surfactant of the total weight of the herbicide formulation.

9. The herbicide formulation as claimed in claim 1 wherein, said anionic surfactants are selected from anionic derivatives of fatty alcohols having 10-24 carbon atoms in the form of ether carboxylates, sulphonates, sulfates, and phosphates; derivatives of alkyl aryl phenols such as tristyrylphenol phosphates and sulphates; and linear alkyl benzene sulphonate and derivatives of dicarboxylic acid in the form of dicarboxylic ester sulfonate such as alkyl sulfosuccinate.

10. The herbicide formulation as claimed in claim 1 wherein, said herbicide formulation comprises from about 0.1% to about 30% of anionic surfactant of the total weight of the herbicide formulation.

11. The herbicide formulation as claimed in claim 1 wherein, said adjuvant of oils of vegetable or animal origin is selected from lower alkyl derivatives of soyabean oil, linseed oil, rapeseed oil, canola oil, olive oil or sunflower oil, emulsified vegetable oil, biodiesel waste (glycol), corn oil and its concentrates, the lower alkyl derivatives of lauric acid, myristic acid, stearic acid, palmitic acid, oleic acid, ricinoleic acid, linoleic acid, linolenic acid, dihydroxystearic acid, fish oil or beef tallow or their derivatives.

12. The herbicide formulation as claimed in claim 11 wherein, said adjuvant is lower alkyl derivatives of soyabean oil.

13. The herbicide formulation as claimed in claim 11 wherein, said formulation comprises from about 0.1% to about 90% of adjuvant of the total weight of the herbicide formulation.

14. The herbicide formulation as claimed in claim 1 wherein, said formulation further comprises one or more other herbicides.

15. The herbicide formulation as claimed in claim 14 wherein, said herbicide is selected from oxyfluorfen, acifluorfen, fomesafen and metribuzin.

16. A process of preparing an herbicide formulation, said process comprising:

(a) mixing an active ingredient selected from the aryloxyphenoxypropionates with at least one solvent and adding an adjuvant selected from oils of vegetable or animal origin or their derivatives to obtain a blend;
(b) optionally dissolving a second herbicide separately in a solvent to obtain a solution and adding solution of second herbicide to said blend;
(c) adding at least one surfactant selected from the group of polyethylene glycol ester of C8-C22 fatty acid and at least one anionic surfactant to said blend; and
(d) optionally adding one or more performance enhancers and mixing it until said blend is homogenized to obtain an emulsifiable concentrate.

17. A method of controlling undesired vegetation, said method comprising applying an herbicide formulation to undesired plants where they occur, said herbicide formulation comprising:
a) at least one herbicidal active ingredient from the aryloxyphenoxypropionates;
b) one or more solvents;
c) one or more surfactants from the group polyethylene glycol ester of C8-C22 fatty acid;
d) one or more anionic surfactants; and
f) one or more adjuvants selected from oils of vegetable or animal origin

18. The method as claimed in claim 17 wherein said herbicide formulation is applied to grassy weeds for post emergence weed control on crops selected from dicot crops, pulses, vegetables, plantation crops and spices.