Patent Description:
Benzoic acid herbicides such as TBA (<NUM>,<NUM>,<NUM>-triiodobenzoic acid), chloramben3-amino-<NUM>,<NUM>-dichlorobenzoic acid) and dicamba (<NUM>,<NUM>-dichloro-<NUM>-methoxybenzoic acid) have been used as herbicides in the form of their esters and salts for many years.

Dicamba (<NUM>,<NUM>-dichloro-<NUM>-methoxybenzoic acid) is a herbicide used in control of broad leaf weeds in winter cereals, pastures, conservation tillage, sugar cane, turf, rice and also in non-crop areas. Dicamba may also be formulated with other herbicides such as other synthetic auxin herbicides as well as glyphosate and glufosinate based herbicides for use in fallow weed control and for use over genetically modified crops.

Benzoic acid herbicides in the acid form have poor solubility in water. For example dicamba in acid form has a water solubility of about <NUM>/L at <NUM> and is commonly formulated as an ester, such as the dicamba methyl ester or an amine salt such as the dimethylamine salt or as a diglycolamine or aminoethoxyethanol salt. The dicamba esters, such as dicamba methyl ester, are more active than the salts but are more likely to volatilize with the potential to damage off-target plants. The benzoic acid esters and salts are each converted in the target plants to the acid form which is active in controlling plant growth.

Some acid herbicides have been formulated as the form of the acid. <CIT>) discloses an acid herbicide concentrate with a specific alcohol ethoxylate emulsifier to form a microemulsion on dilution with water.

<CIT>) describes the use of certain fatty acid amide solvents to form concentrate emulsions (CEs) and emulsifiable concentrates (ECs) of synthetic auxin herbicides. The amide solvents are said to have high solvency for water insoluble compounds in preparing concentrates in the form of an emulsion (CEs) and emulsifiable concentrates (ECs). <CIT> discloses emulsifiable concentrates of carboxylic acid herbicides wherein either N,N-dialkylamide or a N-alkanoyl morpholine are used as solvent. The aim is the stabilization of the emulsions, in particular when more than one herbicide is present. <CIT> is directed to the preparation of stable emulsifiable concentrates of herbicides insoluble in water. A base should be present for the neutralization and is normally an alcohol amine. An oil solvent is the stabiliser but also a co-solvent such as a N-alkyl lactam should be present. The document shows only tebuconazole in the presence of an amide and an amine.

We have found that emulsifiable concentrates of benzoic acid herbicides in amide solvents have poor solution stability on storage giving rise to crystal formation in the concentrate and/or crystal formation on dilution of the concentrate to form an emulsion. Poor storage stability and the consequential formation of precipitates can disrupt effective use of the herbicide through clogging of spray equipment and/or dosing of the herbicide at a lower rate than desired.

There is a need for a more highly stable emulsifiable concentrate of benzoic acid herbicides which stabilises a concentrate of the herbicide in the acid form.

We provide an emulsifiable concentrate comprising dicamba in acid form dissolved in an amide solvent and at least one amine.

Preferably the amount of the amine in the concentrate composition is from <NUM>% to <NUM>% by weight, more preferably from <NUM>% to <NUM>%, still more preferably from <NUM>% to <NUM>% by weight of the amine based on the weight of the emusifiable concentrate.

There is further provided a method of controlling weeds comprising providing an emulsifiable concentrate according to the above, diluting the concentrate with water to provide an emulsion and applying the diluted concentrate to the weeds to be controlled.

The term "emulsion", as used herein, refers to a fine dispersion of minute droplets of one liquid in another in which it is not soluble or miscible and includes microemulsions and macroemulsions. The term "emulsifiable concentrate" refers to concentrates which, on dilution with water, form an emulsion such as a spontaneous milky white emulsion comprising a dispersed water immiscible phase.

Throughout the description and the claims of this specification the word "comprise" and variations of the word, such as "comprising" and "comprises" is not intended to exclude other additives, components, integers or steps.

The concentrate composition comprises benzoic acid herbicide. Typically the benzoic acid herbicide will be present in an amount of at least <NUM> benzoic acid herbicide per litre of emulsifiable concentrate preferably at least <NUM>/L, more preferably at least <NUM>/L, still more preferably at least <NUM>/L and most preferably at least <NUM>/L (such as at least <NUM>/L or at least <NUM>/L).

The emulsifiable concentrate composition comprises an amine. The amine is monoethanolamine or methoxypropylamine.

The concentrate composition comprises an amide solvent. The amide solvent is, in one set of embodiments, present in an amount of from <NUM>% to <NUM>% by weight of the composition, preferably from <NUM>% to <NUM>% and more preferably from <NUM>% to <NUM>% by weight of the emulsifiable concentrate composition.

The amide solvents of claim <NUM> include compounds of formula II:
<CHM>
wherein.

In one embodiment the amide solvent is of formula II wherein.

In a preferred set of embodiments, the amide solvent of formula II wherein.

Examples of the amide solvents include
N,N-dimethyl fatty acid amides such as N,N-dimethyl C<NUM> - C<NUM> fatty acid amide.

The preferred amide "solvents" are fatty acid amides comprising a C<NUM> to C<NUM> aliphatic group.

Specific examples of amide solvents include.

The benzoic acid herbicide emulsifiable concentrate may and preferably will, include a hydrocarbon co-solvent. The hydrocarbon co-solvent preferably has a flash point of at least <NUM>. The hydrocarbon co-solvent preferably comprises at least one hydrocarbon selected from alkyl substituted aromatics such as mono-, di- and trialkyl benzenes and alkyl naphthalenes. For example, C<NUM> alkyl benzene is reported to have a flash point of <NUM> whereas C<NUM> alkylbenzene is reported to have a flash point of <NUM>. A preferred co-solvent is a mixture of C<NUM> to C<NUM> di- and tri-alkyl benzenes, commercially available from Exxon Mobil as Solvesso <NUM>™ and Solvesso <NUM> ™ and their low naphthalene variants.

The hydrocarbon co-solvent is preferably in the range of from <NUM>% to <NUM>% w/w of the benzoic acid herbicide emulsifiable concentrate. Preferably the hydrocarbon co-solvent is present in an amount of from <NUM>% to <NUM>% w/w and more preferably from <NUM>% to <NUM>% w/w of the benzoic acid emulsifiable concentrate.

The benzoic acid herbicide emulsifiable concentrate will typically comprise an emulsifier component. The emulsifier component may, for example, be preferentially in an amount of from <NUM>% w/w to <NUM>% w/w of the dicamba emulsifiable concentrate. The emulsifier component preferably comprises from <NUM>% w/w to <NUM>% w/w and more preferably from <NUM>% w/w to <NUM>% w/w of the concentrate composition.

The emulsifier component may include anionic, non-ionic, cationic or mixed types of emulsifiers. In one embodiment the concentrate comprises an anionic emulsifier in an amount in the range of from <NUM>% w/w to <NUM>% w/w of the concentrate.

In one set of embodiments, the composition comprises an alkylarylsulfonate emulsifier. Alkylarylsulfonates are anionic surfactants and are available in compositions containing suitable counterions which may be optionally substituted ammonium and metal counterions. Examples of alkylarylsulfonates include butylnaphthalenesulfonic acid, the di- and tri-isopropylnaphthalenesulfonic acids, the salts of the condensation products of sulfonated naphthalene and naphthalene derivatives with formaldehyde, the salts of the condensation products of sulfonated naphthalene and naphthalene derivatives with phenol and formaldehyde, and the salts of alkylarylbenzenesulfonic acids such as dodecylbenzenesulfonic acid. Benzenesulfonates, such as alkyl- or arylbenzenesulfonates, e.g. (poly)alkyl- and (poly)arylbenzenesulfonates which are acidic and neutralized with suitable bases, for example having <NUM> to <NUM> carbon atoms per alkyl radical or having up to <NUM> styrene units in the polyaryl radical, preferably (linear) dodecylbenzenesulfonic acid and oil-soluble salts thereof, such as, for example, the calcium salt or the isopropylammonium salt of dodecylbenzenesulfonic acid.

It is particularly preferred that the composition of the invention contain a salt of dodeclybenzenesulfonic acid. Preferred salts include calcium dodecylbenzenesulfonate and monoalkanolamine salts of dodecylbenzenesulfonate such as the monoethanolamine salt of dodecylbenzenesulfonate.

The composition preferably comprises a nonionic surfactant component. Preferred non-ionic surfactants include the condensation products of alkylene oxide with components forming nonpolar groups such as the condensation products of ethylene oxide with fatty alcohols such as oleyl alcohol and cetyl alcohol; the condensation products of ethylene oxide with phenols and alkylphenols such as isooctylphenol, octylphenol and nonylphenol; the condensation products of ethylene oxide with castor oil; the partial esters derived from long chain fatty acids and hexitol anhydrides, for example sorbitan monolaurate, and their condensation products with ethylene oxide; ethylene oxide/propylene oxide block copolymers; lauryl alcohol polyglycol ether acetal.

Examples of nonionic surfactants which may be used alone or in combination in the emulsifier component are listed below, in which EO = ethylene oxide units, such as PO = propylene oxide units and BO = butylene oxide units:.

C<NUM>-C<NUM>-alcohols which may be alkoxylated, e.g. with <NUM>-<NUM> alkylene oxide units, preferably <NUM>-<NUM> EO and/or <NUM>-<NUM> PO and/or <NUM>-<NUM> BO in any order. The terminal hydroxyl groups of these compounds can be terminally capped by an alkyl, cycloalkyl or acyl radical having <NUM> -<NUM> carbon atoms. Examples of such compounds are:.

Genapol® C, L, O, T, UD, UDD, X products from Clariant, Plurafac® and Lutensol® A, AT, ON, TO products from BASF, Marlipal® <NUM> and <NUM> products from Condea, Dehypon® products from Henkel, Ethylan® products from Akzo Nobel, such as Ethylan CD <NUM>.

Copolymers consisting of EO, PO and/or BO units, such as, for example, block copolymers, such as the Pluronic® products from BASF and the Synperonic® products from Uniquema with a molecular weight of from <NUM> to <NUM><NUM>.

Alkyleneoxy adducts of C<NUM>-C<NUM> alcohols, such as the Atlas® <NUM> series, or in particular Atlas G-<NUM> from Croda Crop Care or Hoe® -S3510 from Clariant.

Fatty acid and triglyceride alkoxylates, such as the Serdox® NOG products from Condea or alkoxylated plant oils, such as soybean oil, rapeseed oil, corn oil, sunflower oil, cottonseed oil, linseed oil, coconut oil, palm oil, thistle oil, walnut oil, peanut oil, olive oil or rhicinus oil (i.e. castor oil) , in particular rapeseed oil and castor oil, plant oils also being understood as meaning their transesterification products, e.g. alkyl esters, such as rapeseed oil methyl ester or rapeseed oil ethyl ester, for example the Emulsogen® products from Clariant, salts of aliphatic, cycloaliphatic and olefinic carboxylic acids and polycarboxylic acids, and alpha-sulfo fatty acid esters as available from Henkel. Particularly preferred in this group are castor oil ethoxylates such as TERMUL® ®<NUM> and TERMUL® ®<NUM> from Huntsman.

Fatty acid amide alkoxylates, such as the Comperlan® products from Henkel or the Amam® products from Rhodia.

Alkyleneoxy adducts of alkynediols, such as the Surfynol® products from Air Products. Sugar derivatives, such as amino and amido sugars from Clariant, glucitols from Clariant, alkyl polyglycosides in the form of the APG® products from Henkel or such as sorbitan esters in the form of the Span® or Tween® products from Uniquema or cyclodextrine esters or ethers from Wacker.

Alkyleneoxy adducts based on polyol, such as Polyglycol® products from Clariant. Interface-active polyglycerides and derivatives thereof from Clariant. Surface-active compounds based on silicone and/or silane, such as the Tegopren® products from Goldschmidt and the SE® products from Wacker, and the Bevaloid®, Rhodorsil® and Silcolapse® products from Rhodia (Dow Corning, Reliance, GE, Bayer).

Per- or polyfluorinated surface-active compounds, such as Fluowet® products from Clariant, the Bayowet® products from Bayer, the Zonyl® products from Du Pont and products of this type from Daikin and Asahi Glass.

Surface-active polyvinyl compounds, such as modified polyvinylpyrolidone, such as the Luviskol® products from BASF and the Agrimer® products from ISP or the derivatized polyvinylacetates, such as the Mowilith® products from Clariant or the butyrates, such as the Lutonal® products from BASF, the Vinnapas® and the Pioloform® products from Wacker or modified polyvinyl alcohols, such as the Mowiol® products from Clariant.

Surface-active polymers based on maleic anhydride and/or reaction products of maleic anhydride, and maleic anhydride and/or reaction products of copolymers which include maleic anhydride, such as the Agrimer®- VEM A products from ISP.

Surface-active derivatives of montane, polyethylene and polypropylene waxes, such as the Hoechst® waxes or the Licowet® products from Clariant.

Poly- or perhalogenated surfactants, such as, for example Emulsogen®-<NUM> from Clariant.

Phenols which may be alkoxylated, for example phenyl (C<NUM>-C<NUM>)alkyl ethers or (poly)alkoxylated phenols [=phenol (poly)alkylene glycol ethers], for example having <NUM> to <NUM> alkyleneoxy units in the (poly)alkyleneoxy moiety, where the alkylene moiety preferably in each case has <NUM> to <NUM> carbon atoms, preferably phenol reacted with <NUM> to <NUM> mol of alkylene oxide.

(Poly)alkylphenols or (poly)alkylphenol alkoxylates [=polyalkylphenol (poly)alkylene glycol ethers], for example with <NUM> to <NUM> carbon atoms per alkyl radical and <NUM> to <NUM> alkyleneoxy units in the polyalkyleneoxy moiety, preferably tri-n-butylphenol or triisobutylphenol reacted with <NUM> to <NUM> mol of ethylene oxide,.

Polyarylphenols or polyarylphenol alkoxylates [=polyarylphenol (poly)alkylene glycol ethers], for example tristyrylphenol polyalkylene glycol ethers with <NUM> to <NUM> alkyleneoxy units in the polyalkyleneoxy moiety, preferably tristyrylphenol reacted with <NUM> to <NUM> mol of ethylene oxide.

Examples of surfactants from the group of aromatic-based surfactants are the surfactants of the abovementioned groups, preferably phenol reacted with <NUM> to <NUM> mol of ethylene oxide, available commercially, for example, in the form of the Agrisol® products (Akcros), triisobutylphenol reacted with <NUM> to <NUM> mol of ethylene oxide, commercially available, for example, in the form of the Sapogenat® T products (Clariant), nonylphenol reacted with <NUM> to <NUM> mol of ethylene oxide, commercially available, for example, in the form of the Arkopal® products (Clariant), tristyrylphenol reacted with <NUM> to <NUM> mol of ethylene oxide, for example from the Soprophor® series, such as Soprophor® FL, Soprophor® 3D33, Soprophor® BSU, Soprophor® 4D-<NUM>, Soprophor® CY/<NUM> (Rhodia).

The non-ionic emulsifier present in the compositions of the invention may comprise one such surfactant or a blend of two or more non-ionic surfactants.

The emulsifier is more preferably selected from alcohol ethoxylates, fatty acid ethoxylates, fatty amide ethoxylates and EO/PO block copolymers including butyl based block copolymers. The non-ionic emulsifier preferably comprises in the range of from <NUM>% w/w to <NUM>% w/w of the composition. More preferably the non-ionic emulsifier comprises in the range of from <NUM>% w/w to <NUM>% w/w and more preferably from <NUM>% w/w to <NUM>% w/w of the concentrate.

In one embodiment, the anionic emulsifier comprises from <NUM>% to <NUM>% w/w of the composition and the non-ionic emulsifier comprises from <NUM>% to <NUM>% w/w of the composition.

In one set of embodiments the concentrate composition comprises:.

The composition of the invention has been found to provide good storage stability and also forms an emulsion on dilution with water which has good stability to allow effective application to plants.

There is further provided a method for the preparation of an emulsifiable concentrate of comprising combining benzoic acid herbicide with an amide solvent and amine and heating the compositions, preferably to a temperature of at least <NUM>, more preferably <NUM>, still more preferably at least <NUM> and most preferably at least <NUM>, to provide a solution of the benzoic acid herbicide.

In a further aspect, the invention provides a method of controlling weeds comprising providing an emulsifiable concentrate as hereinbefore described; diluting the concentrate with water to form an emulsion and applying the diluted composition to the weeds.

In a further embodiment the invention provides a method of applying a benzoic acid emulsifiable concentrate composition comprising:.

The emulsifiable concentrate may be combined with the liquid fertilizer with additional water being combined with the concentrate and/ or the fertilizer or alternatively in some cases an emulsion may be formed with the neat concentrate using liquid nitrogenous fertilizer in the form supplied by the manufacturer.

The composition may comprise one or more further actives selected from the group consisting of herbicides, fungicides, insecticides, plant growth regulators, biologicals and mixtures of two or more thereof.

Examples of additional herbicides may be selected from the following classes:.

The weight ratio of dicamba to other herbicide will depend on the nature of the other herbicide and desired loading of dicamba.

However, typically the weight ratio of dicamba to other herbicide (or herbicides) is in the range of from <NUM> : <NUM> to <NUM> : <NUM>. Preferably dicamba will constitute more than <NUM>%w/w of the total herbicide content, more preferably at least <NUM>%w/w and most preferably at least <NUM>%w/w.

In one set of embodiments, the other herbicide comprises a pyridine herbicide selected from the group consisting of picloram, clopyralid, aminopyralid, fluoroxypyr and triclopyr.

In a further set of embodiments, the other herbicide comprises a phenoxyalkanoic acid herbicide selected from the group consisting of <NUM>,<NUM>-D, MCPA, dichlorprop, dichlorprop-P, mecoprop and mecoprop-P.

The invention exhibits increased efficacy of the benzoic acid herbicide on an active gram for gram basis when compared to benzoic acid herbicides presently sold in the marketplace, such as salts, amine salts and esters.

The invention exhibits lower volatility and reduced propensity to drift when compared to other benzoic acid herbicide formulations presently sold in the marketplace.

The invention will now be described with reference to the following Examples.

The examples compare the effect of different alkanolamines on the stability of emulsifiable concentrates. Compositions were prepared by combining the components in Table <NUM> in the amounts listed using the method of manufacture described below.

A composition in accordance with the invention comprising dicamba acid herbicide and monoethanolamine was prepared by combining the components of Table <NUM> using the method of manufacture described below. The results are described in Table <NUM>.

The composition of the invention comprising dicamba acid herbicide was prepared by combining the components shown in Table <NUM> using the Method of Manufacture described. The resulting composition had the properties shown in Table <NUM>.

Formulations and manufacturing method details:.

<NUM>/L Dicamba Acid EC: batch size <NUM>. The composition was prepared by combining the components in Table <NUM> using the method of manufacture described. The properties of the composition are shown in Table <NUM>.

<NUM>/L Dicamba Acid EC: batch size <NUM>, formula similar to previous Examples but prepared using a method of manufacture in which the benzoic acid herbicide was added before emulsifier. The composition was prepared by combining the components shown in Table <NUM> using the method of manufacture. The properties of the composition are shown in Table <NUM>.

<NUM>/L Dicamba Acid EC: batch size <NUM>, formula similar to Example <NUM> but prepared using a method in which HALLCOMID and SOLVESSO <NUM> solvents were initially added.

The composition was prepared by combining the components shown in Table <NUM> using the listed method of manufacture. The properties of the composition are shown in Table <NUM>.

This Example was prepared using Methoxypropyl amine (MOPA) instead of Monoethanolamine (MEA) and by a method in which formulations were attempted to evaluate Methoxy Propyl Amine (MOPA) in Dicamba acid EC. The composition was prepared by combining the components of Table <NUM> using the method of manufacture and were tested for emulsion stability, density and low temperature storage stability. The results are shown in Table <NUM>.

<NUM>/L Dicamba Acid EC: batch size <NUM>, formulation with MOPA, prepared using a new method of manufacture.

The composition was prepared by combining the components shown as Table <NUM> using the method of manufacture listed and provided the results shown in Table <NUM>.

The dicamba acid EC compositions in Table <NUM> were prepared according to them method identified in the Table as set out below.

Step <NUM>: Weigh <NUM>% of HALLCOMID M <NUM>-<NUM>) into a <NUM> beaker, Step <NUM>: Add a magnetic flea to the beaker, place beaker on a hot plate, commence stirring & heat to <NUM> Deg. Step <NUM>: while maintaining temperature at <NUM> degree C, add KEMMAT HF60, Toximul <NUM> ,TERMUL1284 and Solvesso <NUM> Step <NUM>: Continue to mix until a clear solution is achieved Step <NUM>: Add Dicamba tech, maintain temperature at <NUM> degree C,Continue to mix until a clear solution is achieved Step <NUM>: switch off the heating, add alkaline base. Step <NUM>: Continue stirring for approximately <NUM> to <NUM> minutes, or until clear. Step <NUM>: remove the beaker, transfer the content to <NUM> vol. Flask , make up to the mark with Hallcomid M <NUM>-<NUM>.

Step <NUM>: Weigh <NUM>% of HALLCOMID M <NUM>- <NUM> and Solvesso <NUM> ( total qty) into a <NUM> beaker, Step <NUM>: Add a magnetic flea to the beaker, place beaker on a hot plate, commence stirring & heat to <NUM> Deg. Step <NUM>: Add Dicamba tech, continue to mix until a clear solution is achieved Step <NUM>: while maintaining temperature at <NUM> degree C, add KEMMAT HF60,TERMUL1284 and Toximul <NUM> Step <NUM>: continue to mix until a clear solution is achieved Step <NUM>: switch off the heating, add alkaline base. Step <NUM>: Continue stirring for approximately <NUM> to <NUM> minutes, or until clear. Step <NUM>: remove the beaker, transfer the content to <NUM> vol. Flask , make up to the mark. , with Hallcomid M8-<NUM>.

Note: In SS1 and SS3, Dicamba tech. was added after the addition of emulsifiers, while in SS2, SS4, SS5 and SS6 Dicamba tech. was added prior to the addition of emulsifiers. Refer to Method of manufacture for details.

Emulsifiable concentrates were prepared by combining the components shown in Table <NUM> using the method of manufacture shown below. The compositions were found to have good stability and properties shown also in Table <NUM>.

Emulsifiable concentrate compositions were prepared by combining the components shown in Table <NUM> in the parts by weight listed and using the manufacturing method described. Composition properties are also recorded in Table <NUM>.

The following Comparative Examples related to compositions prepared using a range of solvents in accordance with the following procedure:.

Several attempts were made to formulate an EC product using various solvents and emulsifiers, but the formulations were not satisfactory. The combinations with <NUM>% to <NUM>% dicamba loading showed very poor emulsifications.

The emulsifiable concentrates were prepared using the procedure of Comparative Examples <NUM>-<NUM> and the observations listed. In general, the compositions did not have the desired stability.

Claim 1:
An emulsifiable concentrate composition comprising:
• dicamba acid in an amount of at least <NUM>/L;
• fatty acid amide solvent in an amount of from <NUM>% to <NUM>% w/w of the concentrate composition, wherein the fatty acid amide solvent is of formula II
<CHM>
wherein
R<NUM> is selected from the group consisting of hydrogen and C<NUM> to C<NUM> hydrocarbyl;
R<NUM> is selected from the group consisting of C<NUM> to C<NUM> hydrocarbyl;
R<NUM> is selected from the group consisting of C<NUM> to C<NUM> hydrocarbyl; and
R<NUM> and R<NUM> may together from a ring incorporating the nitrogen of the amide comprising <NUM> or <NUM> methylene groups;
• hydrocarbon co-solvent in an amount of from <NUM>% to <NUM>% w/w of the concentrate composition;
• anionic emulsifier in an amount of from <NUM>% to <NUM>% w/w of the concentrate composition;
• non-ionic emulsifier in an amount of from <NUM>% to <NUM>% w/w of the concentrate composition; and
• monoethanolamine, methoxypropylamine or mixture thereof in an amount of from <NUM>% to <NUM>% by weight based on the weight of the concentrate composition.