Patent Application
20100160168
This invention relates to agrochemical compositions and particularly to homogeneous concentrates which form stable dilutions with water, and which include oils and electrolyte agrochemicals such as fertilizer electrolytes or electrolyte pesticides.
Agrochemical compositions can provide nutrients, growth regulators and/or pesticides, e.g. herbicides, insecticides, fungicides or acaricides. To reduce their overall cost in use spray adjuvants as added to water based agrochemical spray mixtures. Various spray adjuvants are in commercial use to provide effects including foam control, increased agrochemical effectiveness, and/or spray mixture modification. Many spray adjuvants, particularly in the United States, are supplied as, especially concentrated, liquids, for example self-emulsifying oil/surfactant compositions—so-called crop oil concentrates (COCs), or readily water soluble or dispersible surfactant formulations—known as concentrated liquid non-ionic surfactants (NIS).
Spray components may include electrolytes e.g. plant nutrients (fertilizers), electrolyte agrochemical actives and other inorganic spray mixture additives. Plant nutrients are typically supplied as bulk solids or concentrated dense aqueous solutions usually at or near saturation, commonly called Liquid Fertilizers (LF). Their high concentration of dissolved electrolyte makes combining LFs with other adjuvant components in high concentration spray solutions challenging because including LFs can result in physical instability or incompatibility of the resulting mixture of pesticide alone or in combination with COC, NIS, and LF products. There are many complex processes producing such incompatibility including coalesence, creaming, sedimentation, flocculation, and heteroflocculation.
COCs typically contain from 60 to 90% (by volume) of agricultural oil or crop oil, and usually include oil soluble emulsifier, typically a blend of anionic and/or nonionic surfactants, that enables self-emulsification of the oil on dilution in water based spray mixtures, typically, at a total surfactant concentration of 1 to 40%, more usually 10 to 17% of the COC. COCs are a cost effective way of including such oils in water based e.g. emulsion, formulations because they are highly concentrated, reducing transport costs, and the disadvantages of water based, particularly emulsion, concentrate formulations, particularly complex development and manufacture, the need to include thickeners, preservatives, and anti-freeze additives (such emulsions may support microbial growth, cream, settle or sediment, and deteriorate over time particularly following freezing and thawing).
Recent improvements in COC cost-effectiveness include increasing the total concentration of oil compatible surfactant emulsifier, from 12-17% about ten years ago to currently about 40%, reducing the area application rate; and/or the selection of specific surfactant types, to give improved performance of the COCs with specific pesticide products.
PCT Published application WO 95/03881 A describes a stable homogeneous COC containing oil, hydrocarbyl saccharide surfactant, and additional non-ionic surfactant that emulsifies readily on dilution in water e.g. in tank mixes giving better weed control with glyphosate salts.
U.S. Pat. No. 5,945,377 describes aqueous spray postemergence herbicide compositions including monosaccharide, particularly fructose, to potentiate herbicidal activity without reducing tolerance of a crop plant to the herbicide.
U.S. Pat. No. 6,589,913 describes glyphosate formulations including lipophilic solvent, lipophobic plant nutrient and oil soluble base which forms a lipophilic solvent soluble complex with glyphosate assisting coupling of the lipophobic plant nutrient and lipophilic solvent. Relatively low concentrations of aqueous electrolyte are described and oil soluble amine salts i.e. cationic surfactants are the only surfactants described as effecting formulation of such compositions.
U.S. Pat. No. 5,356,861 (also U.S. Re-issue 36149) relates to homogeneous aqueous blends of ammonium sulfate and alkyl polysaccharide as the sole surfactant in tank mix adjuvants with glyphosate as herbicide particularly against broadleaf weeds, but does not contemplate including oils in the spray mixture.
U.S. Pat. No. 6,117,820 is directed to aqueous agrochemical concentrates comprising agrochemical electrolyte e.g. salts of glyphosate, fomesafen, glufosinate, paraquat or bentazone; alkoxylated adjuvant; alkylglycoside and co-surfactant, which forms a structured aqueous system with the alkylglycoside. Again this document does not contemplate including oils in the spray mix.
U.S. Pat. No. 6,255,253 describes agrochemical microemulsions with 80% having a droplet size from 10 to 100 nm, containing: alkyl(oligo)glycoside; and oil phase containing: organic water insoluble solvent; and water insoluble agrochemical.
WO 04/100661 A describes COCs including crop oil, saccharide adjuvant, and surfactant combined with water giving a robust, single phase composition allowing delivery of highly concentrated liquid agricultural adjuvant product with a total surfactant concentration similar to those in use today (ca. 10-40% w/w). The saccharide inclusion improves adjuvant formulation cost-effectiveness and enables provision of one very broadly effective adjuvant combining preferred characteristics of the COC, NIS, and newer saccharide adjuvant types.
As indicated by the above prior art, many improved COCs though themselves stable have tended not to be stable when combined directly with highly concentrated electrolyte, and such combined concentrate formulations are nowhere described or hinted at in any of the prior art listed above. This has generally led to separate additions of COCs and electrolyte components to aqueous spray formulations in so-called tank mixes e.g. as described in WO 04/100661 A. Desirable electrolytes include inorganic fertilizers and electrolyte actives particularly pesticides. Using COCs as tank mix additives provides desired adjuvant activity in the spray, but involves adding at least two separate tank mix components. It is recognised that a single concentrate would give significant user advantages, especially simplifying spray mix make up and minimizing product incompatibility.
The present invention is based on a development of COC type concentrates which can stably include substantial electrolyte concentrations, are amenable to bulk handling, and yet readily disperse to form emulsions on dilution with water and/or additional electrolyte solution in a spray mix. Particularly desirable properties sought in these concentrates include stability under cold (0° C.), ambient (typically about 20 to 25° C.), and high temperature (e.g. about 50° C.) conditions, low fluid viscosity, and ready emulsification on dilution into water. Further desirable attributes include rapid dispersion upon dilution in both colder waters (at or near 4° C.) and predissolved electrolyte, low spray mix surface tension, rapid wetting of agricultural substrates and foam control both in the concentrate and on dilution to a spray mix.
Accordingly, the present invention provides an agrochemical concentrate formulation which is a homogeneous stable liquid which is capable of forming a stable dilution with water and which comprises:
The invention particularly addresses the provision of concentrates including plant nutrient (fertilizer) and/or pesticide or, and particularly, herbicide materials. Accordingly the invention includes:
It is particularly desirable to use proportions of the components of the formulation within specific ranges and the present invention therefore includes an agrochemical concentrate formulation which is a homogeneous stable liquid which is capable of forming a stable dilution with water and which comprises:
Generally concentrates of the invention will be diluted with water to produce agrochemical containing spray mixes. Such spray mixes will contain one or more pesticidally active ingredients and/or herbicidally active ingredients and/or nutrients. The invention accordingly includes a concentrate of the invention which has been diluted with water, particularly from 10 to 10000, especially from 10 to 1000, parts water per part concentrate. The invention also includes a method of making an agrochemical spray formulation which comprises diluting a concentrate of the invention with water, particularly from 10 to 10000, especially from 10 to 1000 parts water per part concentrate. If desired, further electrolyte solution e.g. as concentrated electrolyte solution, particularly from 1 to 1000 parts electrolyte solution per part concentrate, may be added to the concentrate before dilution with water. The final overall rate of dilution is typically from 10 to 10000 parts water and further electrolyte solution per part concentrate.
The (diluted) formulations will generally be used to treat crops (or land where crops are to be grown) including to fertilize crops and to kill weeds in or pests on crops.
The invention accordingly includes the use of such (diluted) formulations to treat crops including to fertilize crops and to kill weeds in crops or pests on crops and further provides a method of treating crops or soil adjacent to crop plants or soil in which crops are to be grown with a spray formulation which is or includes a diluted agrochemical concentrate formulation which is a homogeneous stable liquid which is capable of forming a stable dilution with water and which comprises:
The invention is particularly directed to concentrate compositions that are homogeneous and form stable dilutions with water. By homogeneous we mean that the concentrate remains visibly homogeneous (optically clear) and stable for at least 24 hours, desirably for considerably longer e.g. up to 3 months, and sometimes longer. In this context, the concentrate is being considered free from deliberately added disperse phase components such as particulate solids or silicones e.g. present as antifoams (which may undergo dilution induced phase instability), as such deliberately included disperse phase components would be likely to make the concentrate hazy, milky or opaque.
In describing the concentrate as forming a stable dilution with water we mean that the concentrate forms a solution, microemulsion, or emulsion on simple mixing with the dilution water. When the product on dilution is an emulsion (or microemulsion) such compositions may be described as self emulsifying.
The term “biologically efficacious oil” means that the oil either itself has desired biological effects or that the oil is a carrier or solvent for a material with desired biological effects.
The term “stabilising surfactant” refers to a combination of at least one oil compatible electrolyte tolerant surfactant and at least one water soluble, electrolyte tolerant surfactant, which in combination stabilise the combination of the oil and the electrolyte solution to give a fluid homogeneous concentrate.
The oil component typically has a boiling point of over about 200° C. at atmospheric pressure and a melting point typically not higher than about 60° C. It may be or include mineral oil e.g. petroleum oil; silicone oil; optionally hydrogenated vegetable oil, such as optionally hydrogenated coconut, corn, cotton seed, linseed, mustard, neem, niger seed, oiticica, olive, palm, palm kernel, peanut, perilla, poppy seed, rape, particularly canola, seed, safflower, sesame, soybean or sunflower oil; or ester oil. Suitable ester oils include methylated or ethylated seed oils; esters of C1 to C8 alcohols with C8 to C22, particularly C12 to C18, fatty acids e.g. methyl, ethyl propyl and/or 2-ethylhexyl esters of caprylic, capric, lauric, myristic, palmitic, palmitoleic, stearic, iso-stearic, oleic, linoleic and/or linolenic acid(s), especially where such esters have a total of not more than 20 carbon atoms, and are preferably esters of C12 to C15 fatty acid, e.g. methyl, ethyl and/or propyl esters of lauric acid; and esters of C1 to C8 aliphatic or aromatic acids with C1 to C22 linear or branched alcohols e.g. isodecyl or isotridecyl acetate and/or isopropyl or 2ethylhexyl benzoate.
Typically the oil will form 0.5 to 50, more usually 5 to 40, particularly 10 to 35, % by weight of the total concentrate composition.
The stabilising surfactant is a combination of an oil compatible, electrolyte tolerant surfactant component and a water soluble, electrolyte tolerant surfactant component which stabilises the combination of the oil and the electrolyte solution to give a homogeneous concentrate. Desirably the stabilising surfactant combination is itself electrolyte tolerant and using oil soluble hydroxylic non-ionic surfactant(s) as or in the oil compatible surfactant(s) component can contribute to this (see further below).
In particular, it is desirable that:
Further proportions of the surfactant components are desirably within the following ranges:
The oil compatible surfactant component is one or more surfactant(s) which is(are) soluble or stably dispersible in the oil at a concentration that provides surfactant activity effective to stabilise an emulsion of an aqueous solution of the electrolyte in the oil. Typically, the oil compatible surfactant component is or includes a non-ionic surfactant, particularly a hydroxylic surfactant i.e. it retains one or more free hydroxyl groups, as this improves the electrolyte tolerance, and is itself either a liquid that is directly miscible in the oil or is a solid or semisolid that is soluble in the oil. Suitable oil soluble surfactants for use as or in the oil compatible surfactant component include nonionic surfactants such as polyol partial esters, particularly sorbitan (partial) esters, glycerol and polyglycerol partial esters and propylene glycol monoesters of fatty acids; alkanolamide surfactants; alkoxylated fatty alkylamines; and acid form anionic surfactants, such as alkyl sulphonates, alkylbenzene sulfonates, fatty acids, and acid form or partially neutralized (generally at an aqueous pH less than 5) alkyl phosphates and ether phosphates. Among these:
fatty acids—typically C8 to C22 monocarboxylic acids when present at neutral to acidic pH values (when ionised at relatively alkaline pH of from 8 to 12, C8 to C12 fatty acids may also be used as water soluble surfactants or co-surfactants), though care may be needed because fatty acids may be precipitated (as water insoluble salts) by alkali earth metal ions, particularly Ca2+, as in hard water. Examples include caprylic, capric, lauric, myristic, palmitic, palmitoleic, stearic, isostearic, oleic, linoleic, linolenic, docosanoic, behenic, eicosanoic, and arachidonic acids. Separated and/or fractionated or distilled fatty acids from naturally occurring fats and oils are also useful and examples of these include fatty acids derived from coco, palm, palm kernel, rape, particularly canola, soya and corn oils, tallow and lard.
The oil compatible surfactant may be used in combination with co-surfactants such as fatty e.g. C8 to C22, alcohols.
The water soluble electrolyte tolerant surfactant is a surfactant that is soluble in the electrolyte solution at from 20 to 25° C. and desirably will stabilise an emulsion of the biologically effective oil in the electrolyte solution in combination with the aforementioned oil compatible surfactant component—sometimes even on its own, usually within a target pH or sub-range in the overall range from 2 to 12, usually from 3 to 11, and more usually from 4 to 10. Typically surfactant combinations used in the invention will show such stability within the range pH 5 to 9.
Desirably the water soluble surfactant is soluble (and surface active) in a saturated or near saturated aqueous solution of the electrolyte agrochemical across the temperature range from 5 to 30° C., more desirably from 0 to 50° C. Suitable surfactants can be nonionic or ionic, particularly anionic or amphoteric, surfactants. Although water soluble cationic surfactants might provide some of the desired technical effects; they have undesirable environmental and toxicological properties and can contribute to compatibility problems in tank mixes, particularly complex tank mixtures and are, thus, not desirable, and are desirably absent.
Among nonionic surfactants, those including free hydroxyl groups, commonly based on saccharides, such as sugar, particularly glucose, e.g. hydrocarbyl polysaccharides and water soluble polyglycerol and sorbitol derivatives e.g. sorbitol or polyglycerol fatty acid esters having at least one free OH group for each 2 carbon atoms in the functional hydrophobe chain. Among anionic surfactants, high monoester content alkyl ether phosphates of short to medium chain length are especially effective as well as tetrasodium dicarboxyethyl stearyl sulfosuccinamate and alkyldiphenyloxide disulfonates where there is a potential molar charge density of greater than 1 depending on formulated product pH. Among amphoteric surfactants, alkyl iminodipropionates and alkyl amphopropionates are desirable.
Typical water soluble surfactants are: hydrocarbyl polysaccharides (conventionally called hydrocarbyl “polysaccharides” even where the “polysaccharide” moiety contains few or even only one saccharide unit—they are more systematically called hydrocarbyl “oligosaccharides”) are typically mixtures of compounds with mono-, di- and higher oligo-/poly-saccharide units; and desirably are alkyl polysaccharides, especially alkyl polyglycosides.
We particularly use compounds of the formula (and mixtures): R1OGa, where R1 is hydrocarbyl; G is a saccharide residue; and a is (an average value) of at least 1. R1 is desirably, optionally substituted, alkyl, cycloalkyl, aryl, alkaryl, aralkyl or alkenyl, preferably alkyl, and suitably contains from 4 to 22, more usually up to 18, particularly from 6 to 18 and especially from 8 to 12, carbon atoms. R1 can be mixed alkyl groups containing, on average, from 8 to 14 carbon atoms. The saccharide residue G may be derived from one or more of fructose, glucose, mannose, galactose, telose, gulose, allose, altrose, idose, arabinose, xylose, lyxose and ribose or from mixtures of these. The group G is particularly derived from glucose units and the compounds are then glucosides. If derived from sucrose the groups will comprise fructose and glucose residues. The value of a is the degree of polymerisation and typically will be at least 1.1, desirably at least 1.2 and particularly at least 1.3, but typically not more than 8, particularly not more than 4, for example not more than 2. When the glycoside is an alkyl glucoside, the value of a is desirably between 1 and 2.
Particularly useful alkyl polyglucoside are the formula:
CbH(2b+1).O.(C6H10O5)c.H
where b is from 8 to 14, particularly from 8 to 12 and especially 9 to 10, and c is (an average value) from 1 to 2, usually at least 1.3 and not more than 1.9. A particularly useful material has b is from 8 to 11 with an average value of 9 to 10 and c from 1.35 to 1.85.
Surfactant hydrocarbyl saccharides are commercially available and the materials available under the tradenames Atplus 452 and Atplus 438 (from Uniqema) or Triton BG 10 (from Dow Chemicals) or Agrimul PG 2067 and Agrimul PG 2069 (Cognis) can be used satisfactorily.
When present, the proportion of alkyl polysaccharide in the concentrate formulations of the invention are typically from 1 to 40, desirably 2 to 35, particularly 5 to 25, wt %. As is described below in more detail other surfactants may also be included in the concentrate compositions and the total amount of surfactant is typically from 5 to 40, desirably 10 to 35, particularly 10 to 25 wt % total surfactant.
Suitable oil soluble surfactants for use with hydrocarbyl, particularly alkyl, polyglycosides include sorbitan esters; propylene glycol fatty acid esters; polyglycerol fatty acid esters; fatty alkanolamides; mixed mono- and diester alkyl ether phosphates; alkyl ether sulphates; alkylbenzene sulphonates; fatty acids; and mixtures of these.
Anionic surfactants: alkyl ether phosphate surfactants typically of the formula [R2(OA1)dO]eP(O)OM(3-e) where R2 is a C8 to C18 alkyl group; OA2 is an oxyalkylene, particularly an oxyethylene, group; d is (an average value) from 2 to 15; e is (an average value) about 1; and M is H, an alkali metal, such as sodium or potassium, or a C1 to C3 alkyl or C2 to C3 hydroxyalkyl, mono-, di-, or trisubstituted amine or ammonium group. Alkyl ether phosphates with relatively low levels of alkoxylation, may need to be kept relatively alkaline in order to maintain their water solubility (see comments above on such materials as oil soluble surfactants at relatively acid pH values).
When present, the proportion of alkyl or alkyl ether phosphate in the concentrate formulations of the invention are typically from 1 to 40, desirably 2 to 35, particularly 5 to 25, wt %.
Suitable oil soluble surfactants for use with partially or fully neutralized alkyl or alkyl ether phosphates include sorbitan esters, polyglycerol esters of fatty acids, propylene glycol fatty acid esters, fatty alkanolamides, alkoxylated fatty alkylamines, alkylbenzene sulphonates, fatty acids and mixtures of these.
alkyl dicarboxyethyl sulfosuccinamate surfactants of the formula (to be provided), particularly tetrasodium dicarboxyethyl stearyl sulfosuccinamate e.g. available as Monawet SNO-35. Suitable oil soluble surfactants for use with partially or alkyl dicarboxyethyl sulfosuccinamates include sorbitan esters, polyglycerol esters of fatty acids, propylene glycol fatty acid esters, fatty acids and mixtures of these.
acyl sarcosinate surfactants of the formula (to be provided), particularly cocoyl sarcosinate e.g. available as Crodasinic from Croda. Suitable oil soluble surfactants for use with partially or alkyl dicarboxyethyl sulfosuccinamates include sorbitan esters, polyglycerol esters of fatty acids, propylene glycol fatty acid esters, fatty acids and mixtures of these.
alkyl diphenyl ether sulphonates, particularly C10 to C18, especially about C12, diphenyl oxide (diphenyl ether) sulphonates, particularly bis-sulphonates i.e. with one sulphonate group on each phenyl ring, particularly dodecyl diphenyl oxide bis-sulphonate e.g. as available as Dowfax 2A1. Suitable oil soluble surfactants for use with alkyl diphenyl ether sulphonates include sorbitan esters, polyglycerol esters of fatty acids, propylene glycol fatty acid esters, mixed mono- and diester alkyl ether phosphates, alkyl ether sulphates, fatty acids and mixtures of these.
amphoteric surfactants—are (in the present context) ionic surfactants containing a linear or branched, saturated or unsaturated C4 to a C2-2 hydrocarbyl chain covalently bound to (i) at least one primary, secondary, or tertiary nitrogen atom having a free (unbonded) electron pair capable of being protonated to give net positive charge on that nitrogen, and (ii) at least one anionic functional group. Amphoteric surfactants are neutral at their isoelectric point and have either net positive charge at lower pH values and/or net negative charge higher pH values. Among such surfactants are adducts of C8 to C18 primary alkylamines and unsaturated acids and which are typically described as alkylamino mono- or alkylimino di-acids such as C8 to C10 alkyl-, 2-ethylhexyl-, laur-, tallow alkyl-, soya alkyl-, or coco alkyl-aminomono- or iminodi-propionates. Adducts of C5 to C22 fatty acids and aminoethyl ethanolamine (AEEA) (hydroxyethyl alkylimidazolines) and unsaturated acids, such surfactants are typically described as alkyl, particularly hydroxyalkyl amphoacids such as hydroxyethyl (C4 to C8)alkyl-, hydroxyethyl (C7 to C9) alkyl-, hydroxyethyl laur-, and hydroxyethyl coco-amphomono- and amphodi-propionates.
When present, the proportion of amphoteric surfactant in the concentrate formulations of the invention are typically from 1 to 40, desirably 2 to 35, particularly 5 to 25, wt %.
Suitable oil soluble surfactants for use in conjunction with amphoteric surfactants include mixed mono- and di-ester alkyl ether phosphates, alkyl ether sulphates, sorbitan esters, fatty acid partial glycerides, fatty acid polyglycerol esters, propylene glycol fatty acid esters, fatty alkanolamides, alkoxylated fatty alkylamines, alkylbenzene sulfonates, fatty acids and mixtures of these.
In practice, alkyl ether phosphate surfactants are commonly commercially available as mixtures of mono- and di-alkyl ether phosphate esters. This opens the possibility of controlling the pH so that the mono-phosphate is ionised, but the di-phosphate remains un-ionised in the acid form. Such a combination can be effective to provide both the oil and water soluble surfactants as used in this invention.
The electrolyte compatible and water soluble surfactant may be used in combination with hydrotroping surfactants such as sodium, potassium, and ammonium mono- and di(C1 to C4) alkylbenzenesulfonates, mono- and di-(2-butoxyethoxyethyl) phosphates, or C4 to C10 fatty alkyl carboxylates.
Additional surfactant(s), particularly non-ionic surfactants or anionic surfactants, may be included to obtain desired properties in the final composition or in the spray formulation upon dilution e.g. wetting, foam resistance etc. (of course provided that they do not make the concentrate unstable).
The total amount of surfactant in the concentrate is typically from 2.5 to 25 wt % total surfactant based on the total formulation. It may be more practically useful to consider total surfactant concentration in relation to the proportion of oil in the formulation, so that at the general lower end of overall oil concentration of about 1% the proportion of surfactant will typically be about 2.5 parts by weight (pbw) surfactant to 1 pbw oil and at the general upper end of oil concentration of 40 to 50% the proportion of surfactant will typically be about 1 pbw surfactant to 2 pbw oil.
Water is included in the concentrate composition to dissolve the electrolyte agrochemical (fertilizer and/or pesticide) and the polyol or saccharide component (when present) and may aid solublisation of the stabilising surfactant, particularly the water soluble component. The amount of water used is sufficient to dissolve these components, but is desirably sufficiently low for the composition to remain homogenous for at least 24 hours after being made.
Within these guidelines we have found it desirable to use as little water (including water that is supplied to the formulation as solvent or carrier for other components) as is practical—generally limited to the amount required to dissolve (and retain in solution) the electrolyte agrochemical across a desired range of temperatures. Overall the total amount of water present is generally not more than 60%, particularly not more than 45%, and desirably from 15 to 35% by weight of the total formulation. Amounts of less that about 15% reduce the ability to carry an efficacious amount of the water soluble electrolyte agrochemical. The (relatively) higher proportions of water will generally be suitable for incorporating solid fertilizer materials such as ammonium sulfate, urea, ammonium nitrate or ammonium phosphate.
The components and their proportions are preferably chosen such that where any components are readily available (only) as aqueous solutions, such as high fructose corn syrup (HFCS) (see the discussion of polyols below), the composition provided by mixing the composition components is stable, notwithstanding the water which is thereby introduced. The concentrate will usually be a solution of the oil in the water, the surfactant combination acting to solublise the oil, or as an oil-in-water colloidal emulsion or a microemulsion in which the oil is dispersed as very fine droplets such that the composition is clear or transparent.
The electrolyte agrochemical is typically either or both of a fertilizer, particularly a water soluble inorganic fertilizer, or a water soluble ionic pesticide (electrolyte pesticide), usually a herbicide, and most commonly a foliar applied (post-emergence) herbicide when present. Typically the concentration of electrolyte in the concentrate composition is from 1 to 50%, more usually 5 to 40%, particularly 10 to 30% by weight of the total composition.
Among water soluble fertilisers that for electrolyte solutions in water are the common water soluble inorganic fertilizers that provide nutrients such as nitrogen, phosphorus, potassium or sulphur. Examples of such fertilizers include: for nitrogen as the nutrient:
Other water soluble nutrient containing compounds (commonly identified as “micronutrients”) may also be included in the compositions e.g. to provide minor or trace nutrients to the formulation. Similarly, water soluble buffering and chelating agents such as ammonium and alkali metal citrates, gluconates, lactates, and polyacrylates may be included as part or all of the electrolyte component of the formulation.
When present, the fertiliser is typically included as a concentrated aqueous solution e.g. having a concentration of 10 to 90, particularly 10 to 40% by weight and the proportion of anhydrous fertiliser in the total concentrate formulation is typically from 5 to 40, more usually, 10 to 35, particularly 15 to 30, % by weight based on the concentrate.
Water soluble ionic pesticides include particularly water soluble non-selective herbicides such as the glyphosate, gluphosinate and paraquat and diquat types. The well known and widely used broad spectrum glyphosate type of herbicides are N-phosphono-methyl-N-carboxyalkyl compounds, particularly N-phosphonomethyl glycines, usually as a water soluble agrochemically acceptable salt, commonly alkali metal e.g. sodium or potassium or amine e.g. isopropylamine, or trimesium, salts. The gluphosinate type of herbicides are phosphinyl amino acids such as Glufosinate [2-amino-4-(hydroxymethylphosphinyl) butanoic acid] particularly as the ammonium salt. For both the glyphosate and gluphosinate types of herbicide, the main active component is present in aqueous solution as an anion (or overall negatively charged zwitterion). The paraquat and diquat types of herbicides are bipyridinium compounds particularly Paraquat [1,1′-dimethyl-4,4′-bipyridinium] and Diquat [1,1′-dimethyl-2,2′-bipyridinium]. This type of compound is present in aqueous solution as a cationic ammonium species.
When present, the electrolyte pesticide it typically included in the concentrate compositions typically from 1 to 50%, more usually, 5 to 40%, particularly 5 to 35% by weight based on the concentrate.
Overall, the concentration of the water soluble electrolyte agrochemical will typically be at least 5% for materials that are less soluble in water such as triammonium phosphate and up to 50% by weight for more water soluble materials e.g. urea and/or ammonium nitrate. Generally the concentration will be close to saturation as this gives the highest concentration of this material in the concentrate formulation. The saturation concentration (usually between 0 and 50° C.) in combination with the amount of water included in the formulation determine the amount of water soluble electrolyte agrochemical. Generally, it is particularly useful to make the concentrates using (premixed) aqueous solutions of the water soluble electrolyte agrochemicals as near as is practically possible to their saturation concentration at about 20° C.
The concentrate further desirably includes a polyol component to improve fluid viscosity, compatibility, ease of dispersion in spray mixtures and concentrate stability. The polyol component is a non-surfactant material having multiple free OH groups and will usually be provided to the formulation as a liquid component conveniently included by mixing it with the electrolyte solution to form a stable premixture.
The polyol can be a simple polyhydroxy material such as a glycol e.g. ethylene or propylene glycol, glycerol, polyglycerol or polyols such as sorbitol, pentaerythritol, trimethylol ethane or trimethylol propane. Where the polyol is a liquid e.g. ethylene or propylene glycol, glycerol or polyglycerol, it may be used as neat material, and where the polyol is solid it will usually be used as a solution in water or a suitable organic solvent such as a glycol e.g. ethylene or propylene glycol or glycerine. When the polyols are used as aqueous or organic solutions, the solutions typically have a polyol concentration of from 50 to 95% by weight.
When used the polyol is typically present in an amount of from 1 to 25, more usually from 2 to 15, and particularly from 3 to 10, % by weight of the concentrate formulation.
As well as simple polyols, saccharides may be used, and because saccharides are generally solids, they will usually be used as solutions. The saccharide may be a monosaccharide, oligosaccharide or a polysaccharide or mixture of these and the saccharides may be linear, branched, or cyclic. Functional saccharides are also useful and include either or both acid and amine functional sugars such as N-methylglucamine, gluconic acid, and glutaric acid. Where the saccharide is a solution, the solvent may be water or an organic hydrophilic solvent such as propylene glycol, or glycerol or mixtures of these, but is desirably water. Such liquid saccharide solutions are commonly called “syrups”. Oligosaccharides present in solution are commonly called maltodextrins while polysaccharides are commonly called dextrins. Among liquid saccharide solutions, materials of particular use in this invention include compounds and mixtures of compounds described as corn syrup, HFCS (high fructose corn syrup), corn sweetener, invert sugar, invert sugar syrup, sugar, sugar syrup, glucose, fructose, sucrose, lactose, maltose, corn syrup solids and maltodextrins. Such liquid saccharide solutions are generally homogeneous and stable for at least 24 hours. Typically saccharide solutions used in this invention contain from 20 to 40% by weight of water.
Desirable oligosaccharides are of the general formula: HO.(C6H10O5)n.H where n is (an average value) of from 1 to 50. In particular, the saccharide may be one in which the average value of n is from 1 to 5. A particularly useful material of this type has n of approximately 1 and where the saccharide is a monosaccharide keto-sugar, particularly fructose. Fructose is commercially available as HFCS and the material designated for example as IsoClear 55 by Cargill can be used satisfactorily.
The saccharide is typically included in the concentrate compositions from 1 to 30, more usually, 5 to 20, particularly 5 to 15% by weight based on the concentrate. Expressed as the liquid saccharide the amount used is typically up to about 20% by weight of the concentrate formulation.
A further optional component that may be included to improve compatibility, stability and/or bioperformance of the concentrate formulations is one or more polyelectrolyte polymers. Suitable polymers are those which are soluble in the, typically saturated or near saturated, electrolyte solutions, and can include water soluble polyacrylates maleate polymers and copolymers e.g. styrene maleic anhydride copolymers, maleic-acrylic copolymers and sulphonated polystyrenes. When used the polyelectrolyte polymer is typically present in an amount of from 1 to 20, more usually from 1 to 10, and particularly from 1 to 5, % by weight of the concentrate formulation.
The concentrate formulation may also include one or more of other surfactants, particularly non-ionic and/or anionic surfactants, and/or additives such as antifoam or foam suppressant materials. As is noted above, the inclusion of silicone antifoam materials may cause minor haziness or milkiness in the concentrate formulation because the silicone is not completely homogeneously dissolved in the formulation. On dilution the silicone will come out of solution and migrate to the liquid/air interface so as to effect the desired foam control.
The relative proportions of the components of the formulation are desirably as follows:
The concentrate is typically a light yellowish to amber readily pourable (at ambient temperature) liquid of relatively low fluid viscosity suitable for pumping and bulk handling. Particularly desirable compositions are stable across a temperature range from about −10° C. to about 50° C. for a period of 30 days and show acceptable dilution stability i.e. no oil separation and minimal creaming or sedimentation when diluted between 1 and 2.5% by volume even in 50, 342, and 1000 ppm hardness waters.
The concentrate formulations of the invention can in many instances be successfully made up by directly mixing the components together in an unspecified order. Usually simple mixing will be adequate to form the homogeneous concentrate although the use of specified premixes and particular orders of addition typically show better results.
Greatest product consistency is provided when a form of emulsion inversion processing is applied. The inversion process may desirably be done either by: (1) changing the differential solubility of the selected surfactant composition by increasing or decreasing the degree of ionization for initially unneutralized or uncharged ionic surfactants, or (2) by progressively changing the ratio of water soluble electrolyte tolerant surfactant to oil compatible electrolyte tolerant surfactant.
For ionic surfactants, phase inversion may be carried out by solubilizing for example mixed mono-diester alkyl ether phosphate in the biologically efficacious oil at a desired concentration, often between 25% and 75% of the total finished oil and surfactant premixture weight. This premixture subsequently may be dispersed with shear into the target concentrated electrolyte, already containing any optional polyols, saccharides, or polymers. Alternatively, for acid mono- and diester alkyl ether phosphate surfactants an alkalizing agent e.g. ammonium or potassium hydroxide, mono- di- or triethanolamine may be gradually added to reach a total amount sufficient to achieve a target pH (greater than 5, often between 5.5 and 8.5) during which the dispersion increases in homogeneity and rises in viscosity until it passes through its inversion point to becomes a stable microemulsion.
In the case of completely nonionic systems or fully charged ionic species e.g. neutralized anionic, and neutralized amphoteric surfactants (typically already in aqueous solution at between 25 and 70% active surfactant by weight) the surfactant solution can be gradually added to reach a total amount sufficient to drive the mixture through its inversion point to become a stable microemulsion.
The concentrate formulations of the invention will generally be used by first being diluted with water to generate an agricultural spray mixtures containing an agrochemical which is then used to treat crops (or land where crops are to be grown) including to fertilize crops and to kill weeds in or pests on crops, by spraying. Such spray mixtures will contain one or more pesticidally active ingredients and/or nutrients.
The invention further includes a diluted formulation which comprises a composition comprising components (a), (b) and (c) according to the invention with from about 10 to about 10,000 times the weight of the composition of water. The concentrate compositions of the invention emulsify readily on dilution in water to form the formulation. At relatively low levels of dilution, the diluted product will be an oil-in-water emulsion having a relatively high concentration of oil. This intermediate emulsion subsequently can be further diluted by water or an aqueous solution or suspension of other components desired in the final formulation.
In a further aspect, the invention provides a method of applying a formulation of the invention to a substrate. Embodiments of this method include a method of treating vegetation, particularly a crop or weeds in soil in which a crop is sown subsequently, by applying to plants and/or soil a diluted concentrate formulation of the invention which comprises an agrochemical.
The agrochemical may be one or more growth regulators, herbicides, and/or pesticides, for example insecticides, fungicides or acaricides and the invention accordingly includes:
In this embodiment, the effect of the agrochemical, whether one or more growth regulators, herbicides, and/or pesticides, for example insecticides, fungicides or acaricides, may be potentiated by the oil component and/or the saccharide and/or the surfactant composition present in the composition.
The agrochemical may be one or more fertiliser and/or plant nutrient and/or micronutrient and the invention accordingly includes:
Desirably the agrochemical is a combination of one or more growth regulators and/or herbicides and/or pesticides with a fertiliser and/or plant nutrient and/or micronutrient and the invention accordingly includes:
The following Examples illustrate the invention. All parts and percentages are by weight unless otherwise indicated.
Oil Soluble Surfactants
OSS1 nonylphenol 9-ethoxylate, Renex 698, ex Uniqema
OSS2 sorbitan monolaurate, Span 20, ex Uniqema
OSS3 C12/15 alcohol 4-ethoxylate, nonionic surfactant, Synperonic A4, ex Uniqema
Fatty Acid Co-Surfactants
FA1 oleic acid
FA2 tall oil fatty acids, Pamak MFAF, ex Hercules
Water Soluble Surfactants
Oils
Oil1 paraffinic mineral oil, Sun 7N, ex Sunoco
Oil2 methyl oleate ester oil, Priolube 1400/1530, ex Uniqema
Oil3 d-limonene terpene oil, ex Florida Chemicals
Oil4 isoparaffinic mineral oil, Isopar M, ex ExxonMobil
Oil5 aromatic naphtha oil, Aromatic 150, ex ExxonMobil
Oil6 a blend of 50 wt % Oil1, 25 wt % Oil5 and 25 wt % Oil3
Oil7 methylated soybean oil, ex Soy Power
Electrolytes
Elec1 ammonium sulphate (anhydrous)
Polyols
Samples of formulated adjuvants were subjected to storage testing to assess their stability over extended periods or non-ambient temperatures. The storage conditions are indicated in abbreviated form as Time/Temp—times in days (D) or weeks (W) and temperatures are indicated as amb=ambient or in ° C. Samples are assessed as stable if they remain clear over the storage period, no sep=no visible separation of the stored sample confirming excellent stability. Samples which are not fully stable on extended storage are noted as hazy/cloudy (sl=slightly; v sl=very slightly) or by the amount of separation by volume (as a % figure) bs=bottom separation and is =top separation.
No Neutralisation Required
Neutralisation Required
In either case, the final stable formulations are substantially transparent liquid that either remains transparent or whitens (“blooms”) upon dilution in water (of various hardness).
Crop oil/surfactant concentrate (COC) formulations were made up as described above (no neutralisation) dissolving the oil compatible surfactant and co-surfactant in the crop oil at 40% by weight. In each case the COC was a clear yellowish liquid which was stable and self-emulsifying on dilution with water. Separately, ammonium sulphate was dissolved in water to give a 40 wt % aqueous solution and this electrolyte solution mixed with the COC and the alkylpolysaccharide water soluble surfactant and high fructose corn syrup was added under agitation to give the final combined adjuvant formulation. The materials used and amounts (weight percentages on the overall formulation) are set out in Table 1 below.
The electrolyte containing COC adjuvant formulation of Example 1.1 was a slightly hazy dark brown solution and Example 1.2 a dark brown solution with a greenish tint. Both formulations were stable at ambient temperature and readily emulsified on dilution with water.
An aqueous electrolyte fertilizer solution was made up from the following components:
Crop Oil Concentrates were made up using Oil1 oil compatible surfactant (OSS1) and co-surfactant (FA1) as follows:
The final adjuvant formulations were made up as generally described above (for nonionic surfactants), using an alkyl polysaccharide surfactant (WSS1) as the water soluble surfactant using the weight proportions of formulation components set out in Table 2a below.
The overall percentage composition of the final adjuvant compositions and their properties are set out in Tables 2b and 2c below.
Further formulations were made up to test variation in the proportions of oil compatible surfactant and co-surfactant using the aqueous electrolyte fertilizer solution used in Example 2. The Crop Oil Concentrates were made up using 60 wt % Oil1 and 40 wt % combined oil compatible surfactant (OSS1) and co-surfactant (FA1) as set out in Table 3a below:
The final adjuvant formulations were made up as generally described above (for nonionic surfactants), using an alkyl polysaccharide surfactant (WSS1) as the water soluble surfactant using the proportions of formulation components (parts by weight) set out in Table 3b below:
The overall percentage composition of the final adjuvant compositions and their behaviour under test storage conditions are set out in Tables 3c and 3d below:
An aqueous electrolyte fertilizer solution was made up from the following components:
Portions of this solution were formulated as described above into three electrolyte/crop oil adjuvant combinations labelled “A”, “B” and “C” having the compositions (wt %) set out in Table 4a below:
Portions of these three combinations were mixed in the proportions set out in Table 4b below to give stable formulations. Table 4b also includes the calculated percentage composition of the adjuvant formulations:
All these formulations were stable for 24 hours at Ambient temperature.
Alkaline solvent microemulsion concentrates were made up as follows. Seven electrolyte/crop oil adjuvant combinations labelled “A1”, “A2”, “A3”, “B1”, “B2”, “C1”, “C2” and “C3”, having the following percentage compositions:
were made up generally as described above. Portions of these seven combinations were mixed in the proportions set out in Table 5a below to give stable formulations.
The calculated percentage composition of the stable adjuvant formulations is set out in Table 5b below.
All these formulations were stable for 24 hours at Ambient temperature.
This application claims the benefit of priority from U.S. Provisional Application No. 60/907,648, filed Apr. 12, 2007. This application, in its entirety, is incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/US08/04721 | 4/11/2008 | WO | 00 | 3/1/2010 |
| Number | Date | Country | |
|---|---|---|---|
| 60907648 | Apr 2007 | US |
