Fatty acid-based herbicide composition

Abstract

A herbicidal composition having an acidic pH and comprising water, a fatty acid having 6 to 12 carbon atoms, an alcohol alkoxylate, a hydrophobic liquid, a pH-sensitive hydrogel-forming polymer, and fumed silica.

Description

[Technical Field]

[0001] The present invention relates generally to the fields of horticulture, agriculture, and controlling unwanted plant growth. In particular, the present invention relates to fatty acid-based herbicidal compositions, methods for their preparation, and their use and application to kill or retard the growth of plants. [Background technology]

[0002] The use of herbicides to control unwanted plant growth is common in both home gardening and commercial agriculture, and herbicides are also commonly used to control unwanted plant growth around infrastructure such as public facilities.

[0003] Although beneficial, if not essential, in modern horticulture / agriculture and infrastructure maintenance, a major drawback of many herbicides currently in use is their toxicity to humans, animals, and the environment in general.

[0004] Glyphosate (N-(phosphonomethyl)glycine) is a widely used broad-spectrum systemic herbicide and plant desiccant. Despite being an effective herbicide, its excessive use has led to the development of glyphosate resistance in the soil. Furthermore, mounting evidence suggests that its use is having adverse effects on the environment and human health. As a result, there is currently a growing movement worldwide to ban the use of glyphosate-based herbicide compositions.

[0005] Other herbicide compositions that are more environmentally friendly are also known. For example, compositions containing fatty acids have been shown to exert herbicidal activity. It has been found that, upon application, the fatty acid active ingredient in such compositions decomposes very quickly to relatively non-toxic residues. Thus, fatty acids are promising as herbicide active ingredients. However, when used at recommended rates, conventional fatty acid-based herbicide compositions often require relatively high concentrations of fatty acid to promote sufficient herbicidal activity. For example, such conventional compositions are typically applied at rates of at least 30 kg / hectare of fatty acid. Furthermore, conventional fatty acid-based herbicide compositions often require frequent applications to effectively control plants. The need for higher active substance concentrations and more frequent applications makes the use of such herbicidal compositions economically unattractive. Although fatty acids pose fewer environmental concerns than other herbicidal active substances (due to their natural origin and biodegradability), their use at relatively high concentrations to achieve the desired herbicidal effect poses at least economic obstacles, if not environmental concerns.

[0006] Thus, there remains an opportunity to develop fatty acid-based herbicidal compositions with improved efficacy, particularly those that allow the fatty acid component to be used effectively at lower doses and still prove effective. Summary of the Invention [Means for solving the problem]

[0007] The present invention provides a herbicide composition having an acidic pH, comprising water, a fatty acid having 6 to 12 carbon atoms, an alcohol alkoxylate, a hydrophobic liquid, a pH-sensitive hydrogel-forming polymer, and fumed silica, wherein the pH of the composition does not promote hydrogel formation of the pH-sensitive hydrogel-forming polymer.

[0008] The present invention also provides a method for preparing a herbicide composition, comprising the steps of providing a silica-containing aqueous composition comprising water, fumed silica, and a pH-sensitive hydrogel-forming polymer; mixing the silica-containing aqueous composition with an alcohol alkoxylate to form a liquid alcohol alkoxylate-containing composition; and mixing the liquid alcohol alkoxylate-containing composition with a fatty acid having 6 to 12 carbon atoms and a hydrophobic liquid to prepare a herbicide composition, wherein the herbicide composition thus prepared has an acidic pH that does not promote hydrogel formation of the pH-sensitive hydrogel-forming polymer.

[0009] The present invention further provides herbicidal compositions made according to the methods of the present invention.

[0010] The present invention also provides a method for killing or retarding the growth of plants, which comprises the step of contacting the plants with a herbicidal composition according to the present invention.

[0011] The present invention further includes a method of controlling plant growth in a locus, comprising the step of applying to said locus a herbicidal composition according to the present invention.

[0012] The present invention also provides the use of the herbicidal composition according to the invention for killing or retarding the growth of plants.

[0013] The present invention further provides the use of a herbicidal composition according to the invention for controlling plant growth in a locus.

[0014] Surprisingly, it has been found that the herbicidal composition according to the invention has improved herbicidal action compared to conventional fatty acid-based herbicidal compositions, particularly in view of the need for lower dosages and less frequent applications.

[0015] In particular, unlike conventional fatty acid-based herbicidal compositions, the herbicidal composition of the present invention can exhibit excellent herbicidal activity at a fatty acid concentration as low as 1% or 2% by weight. For example, the herbicidal composition of the present invention is advantageous in that it can be effectively used at a dosage of about 15 kg / hectare of fatty acid.

[0016] Naturally, the herbicidal compositions of the present invention exhibit excellent herbicidal activity at high fatty acid concentrations, but what is particularly surprising and advantageous is their effectiveness at low fatty acid concentrations.

[0017] Without wishing to be limited by theory, it is believed that the enhanced herbicidal activity of the compositions of the present invention is due to the unique combination of the composition's components. In particular, it is believed that the non-fatty acid components of the composition in effect function as adjuvants to enhance the herbicidal activity of the fatty acid component and make it more bioavailable.

[0018] Again, without wishing to be limited by theory, it is believed that the C6-C12 fatty acid component of the herbicidal composition of the present invention promotes so-called "burndown" of plant tissue in much the same way as with conventional herbicidal compositions. However, it has surprisingly been found that the adjuvant component used in the composition of the present invention enhances the delivery and effectiveness of the fatty acid component, allowing the fatty acid to be used at lower concentrations while still achieving excellent herbicidal activity.

[0019] It is believed that the adjuvant components in the composition, i.e., water, alcohol alkoxylate, hydrophobic liquid, pH-sensitive hydrogel-forming polymer, and fumed silica, collectively provide an effective vehicle for delivering the fatty acid component to the plant surface and enhancing uptake of the fatty acid component by the plant at an acidic pH that does not promote hydrogel formation of the pH-sensitive hydrogel-forming polymer. The adjuvant components, individually and / or collectively, are believed to function in one or more ways to enhance delivery of the fatty acid component.

[0020] For example, it is believed that the alcohol alkoxylates at least play a role in facilitating the stabilization of the composition prior to application to the plant (as a concentrate or a ready-to-spray composition) and in facilitating the adhesion of the composition to the plant surface upon application.

[0021] It is believed that the hydrophobic liquid at least minimizes loss of composition from the plant surface upon application and / or facilitates removal / decomposition of the waxy cutin coating on the plant surface, facilitating drying and / or delivery of the fatty acid components to the plant tissue.

[0022] When the composition has an acidic pH, the pH-sensitive hydrogel-forming polymer does not exist as a hydrogel itself, and the increase in viscosity of the applied herbicide composition is limited, making it easy to apply by spraying, etc. However, when the herbicide composition is applied to a plant with at least alkaline sap, the pH-sensitive hydrogel-forming polymer transforms into a hydrogel, increasing the viscosity of the surrounding area and significantly destabilizing the plant's metabolism. This is thought to make the plant more susceptible to the effects of fatty acid components. In addition, using a pH-sensitive hydrogel-forming polymer to form a hydrogel in at least part of the process for producing the herbicide composition can greatly facilitate the dispersion of fumed silica in the final composition.

[0023] The fumed silica component of the composition is believed to facilitate the delivery of the components of the herbicide composition to plant tissue. Achieving good dispersion of the fumed silica in the herbicide composition is believed to be important for facilitating the delivery of the components of the herbicide composition to plant tissue.

[0024] Surprisingly, it has been found that all of the components of the composition as a whole act synergistically to enhance the herbicidal efficacy of the fatty acid-based herbicidal composition.

[0025] The variety of components in the herbicidal compositions of the present invention, and the low concentrations of these components typically used in practice, make the compositions much more economically and environmentally acceptable.

[0026] Other aspects and embodiments of the invention are discussed in more detail below. DETAILED DESCRIPTION OF THE INVENTION

[0027] The present invention provides a herbicidal composition. As used herein, the term "herbicide" is intended to be understood in its conventional sense and to define a composition containing one or more components capable of killing or retarding plant growth. Herbicides are generally applied to kill or retard the growth of one or more undesirable plant species, such as one or more weeds. Thus, the term "herbicidal action" refers to the potential or actual function of a composition acting as a herbicide to kill or retard plant growth.

[0028] As will be discussed in more detail, the herbicidal compositions of the present invention have an acidic pH. By the composition having an acidic pH, it is meant that the pH of the composition is less than 7.

[0029] The herbicidal compositions of the present invention can be classified as non-selective herbicides, where the term "non-selective" refers to the spectrum of plant species against which the herbicide is effective; non-selective herbicides are effective against most, if not all, plant species.

[0030] Typical plant species on which the herbicidal composition of the present invention exerts herbicidal activity include, but are not limited to, annual broadleaf weeds (such as blackberry nightshade, capeweed, burr medic, creeping oxalis, milk thistle, spear thistle, wireweed, pigweed, fat hen, shepherd's purse, algae, lichens, mosses, and mosses) and annual grasses (such as annual ryegrass), perennial broadleaf weeds (such as flatweed, hair hawkbit, lamb's tongue, dandelion, evening primrose, bell vine, and white clover) and perennial grasses (such as couch grass, kikuyu, lovegrass, paspalum, volunteer wheat, and perennial ryegrass).

[0031] The herbicidal compositions of the present invention are liquid-based and can be conveniently applied to the target plant or locus using conventional liquid-based herbicide application means, including, but not limited to, spraying, pouring, or dusting.

[0032] The herbicidal compositions of the present invention will generally be used as post-emergent (ie, applied directly to the plant) herbicides.

[0033] The herbicidal compositions of the present invention will typically be applied so as to contact at least a portion of the plant structure above ground, for example, the composition may be applied to the leaves and / or stem structure of the plant.

[0034] The herbicidal composition is used in amounts and concentrations of the components to obtain the desired herbicidal effect. The desired herbicidal effect may be to kill the plant or simply to retard its growth. If necessary, the herbicidal composition may be applied to the plant or locus multiple times to obtain the desired herbicidal effect.

[0035] As one skilled in the art will appreciate, the amounts and concentrations of the components in the herbicide composition to be used in a given application will vary depending on several factors, such as the plant species and the desired herbicidal outcome (i.e., killing the plant or simply slowing its growth). Given the teachings herein, one skilled in the art will be readily able to select the amounts and concentrations of the components in the herbicide composition to be used in a given application.

[0036] The herbicidal compositions of the present invention are advantageously provided as concentrates that can be used directly or diluted with water depending on the intended application. For example, the concentrate form of the composition may be used on hardwood plants such as blackberry or lantana by injecting it into the root zone or by spraying it directly onto freshly cut stems, or the concentrate form may be diluted with water and used to spray, for example, broadleaf weeds or grasses.

[0037] Unless otherwise specified, the expression "wt. %" as used herein is intended to mean the weight percent of a particular component relative to the total weight of all components contained in the herbicide composition.

[0038] According to the present invention, the herbicidal composition has an acidic pH. By acidic pH, we mean a pH less than 7. Conversely, when we refer to an alkaline or basic pH, we mean a pH greater than 7.

[0039] Generally, the pH of the herbicidal composition will be in the range of about 2 to about 5, or about 3 to about 4.

[0040] As discussed in more detail below, the herbicidal composition of the present invention includes a pH-sensitive hydrogel-forming polymer. Furthermore, the acidic pH does not promote hydrogel formation of the pH-sensitive hydrogel-forming polymer. Instead, the pH of the composition must be made more alkaline (i.e., moved toward the alkaline side) in order for the pH-sensitive hydrogel-forming polymer to form a hydrogel. Without wishing to be limited by theory, it is believed that when the composition has an acidic pH, the hydrogel-forming polymer exists in a non-ionized state and, as a result, does not form a hydrogel by itself. However, as the pH of the composition increases toward an alkaline pH, the pH-sensitive hydrogel-forming polymer ionizes, thereby promoting swelling and hydrogel formation. Hydrogel formation significantly increases the viscosity of the composition and / or the liquid environment in which the composition resides.

[0041] Because the herbicidal compositions of the present invention have an acidic pH that does not promote hydrogel formation of the pH-sensitive hydrogel-forming polymer, the hydrogel-forming polymer exists in a non-hydrogel state, and as a result, the polymer imparts limited, if any, viscosity-increasing effect to the composition. Therefore, when the composition is in the acidic state, it can be easily applied by conventional techniques, such as spray application.

[0042] The acidity of the composition will typically be provided by one or more components of the composition, for example, a fatty acid component and / or a pH-sensitive hydrogel-forming polymer can provide the acidic pH of the composition.

[0043] Alternatively, one or more other ingredients may be included in the composition that provide or help provide an acidic pH to the composition, including, but not limited to, hydrochloric acid and acetic acid.

[0044] In one embodiment, the composition of the present invention comprises acetic acid.

[0045] As long as the herbicidal composition of the present invention is maintained at an acidic pH that does not promote hydrogel formation of the pH-sensitive hydrogel-forming polymer, the composition may contain one or more additives to adjust the pH. For example, the composition may contain conventional buffers and / or bases, such as alkali metal hydroxides (e.g., sodium hydroxide).

[0046] Adjusting the pH of the herbicide composition may be useful in the method of preparing the composition, further details regarding which method are outlined below.

[0047] In one embodiment, sodium hydroxide is used as the pH adjusting agent in preparing the herbicidal composition.

[0048] In another embodiment, the herbicidal composition does not contain potassium hydroxide.

[0049] The herbicidal composition of the present invention comprises water, hi one embodiment, the water is demineralized water.

[0050] The amount of water present will generally vary from about 0.1% to about 98% by weight.

[0051] Of course, the less water a composition contains, the more concentrated it will be. The concentration of a composition is often adjusted for a given application.

[0052] When referred to as a concentrate, the herbicide composition will typically contain less than about 10% by weight, less than about 7% by weight, or less than about 5% by weight water, or less than about 2% by weight water.

[0053] In one embodiment, water is present in the herbicide composition in an amount of less than about 10% by weight, less than about 7% by weight, less than about 5% by weight, or less than about 2% by weight water.

[0054] In another embodiment, water is present in the herbicide composition in an amount ranging from about 0.1% to about 10% by weight, from about 0.1% to about 7% by weight, from about 0.1% to about 5% by weight, from about 2% to about 10% by weight, from about 2% to about 7% by weight, or from about 2% to about 5% by weight.

[0055] As discussed below, herbicidal compositions are typically prepared as concentrates that are then diluted with water as needed before use.

[0056] Depending on the intended use, a concentrate form containing about 2% by weight water can be diluted with additional water to provide a sprayable working composition having a ratio of concentrate to water of, for example, 1:5, 1:10, 1:15, 1:20, 1:25, 1:30, or even up to 1:40.

[0057] When referred to as a spray working composition, the herbicide composition will typically contain at least about 50%, at least about 70%, or at least about 80% water by weight.

[0058] In another embodiment, water is present in the herbicide composition in an amount ranging from about 50% to about 98% by weight, from about 70% to about 98% by weight, from about 80% to about 98% by weight, or from about 85% to about 95% by weight.

[0059] In preparing such a spray working composition, a portion of the water used to dilute the concentrate composition may be replaced with acetic acid. For example, the spray working composition of the present invention may contain about 1% to about 6% by weight of acetic acid.

[0060] In one embodiment, a herbicide composition made according to the methods of the present invention is mixed with water and acetic acid to obtain a ready-to-use herbicide composition having an acidic pH that does not promote hydrogel formation of the pH-sensitive hydrogel-forming polymer.

[0061] A herbicide composition provided in a "ready-to-use" form means that the herbicide composition can be used for application without further modification, i.e., the herbicide composition provides its components in concentrations suitable for application as is.

[0062] The herbicidal composition according to the present invention contains a fatty acid having 6 to 12 carbon atoms. The term "6 to 12 carbon atoms" means that the fatty acid contains 6 to 12 carbon atoms. The fatty acid may be a saturated fatty acid, an unsaturated fatty acid, a straight-chain fatty acid, or a branched-chain fatty acid.

[0063] The fatty acid component of the composition is the key active ingredient in the herbicide.

[0064] In one embodiment, the fatty acid is a straight chain fatty acid.

[0065] By "fatty acid," it is intended to mean that a carbon chain or "aliphatic" moiety is covalently attached to a carboxylic acid, and that the carboxylic acid is in a protonated state (i.e., not in a salt state).

[0066] Those skilled in the art will appreciate that when the fatty acid having 6 to 12 carbon atoms is in its carboxylic acid form, it will have limited solubility in the water component of the herbicidal composition. That is, the fatty acid component will be present in the composition primarily as the oil phase of the emulsion. Further details regarding the stabilization of such emulsions are discussed below.

[0067] Nevertheless, those skilled in the art will appreciate that, even with low aqueous solubility, fatty acids having 6 to 12 carbon atoms can still contribute to the acidity of a herbicidal composition due to their high surface activity. However, those skilled in the art will also appreciate that as the carbon chain length of a fatty acid increases beyond 12 carbon atoms, its solubility in water decreases significantly, and such higher fatty acids have little, if any, effect on the pH of aqueous systems.

[0068] In one embodiment, the fatty acid having 6 to 12 carbon atoms is selected from caproic acid, enanthic acid, caprylic acid, nonanoic acid (also known as pelargonic acid), capric acid, undecylic acid, lauric acid, and sebacic acid.

[0069] In another embodiment, the fatty acid is selected from fatty acids having 8 to 12 carbon atoms.

[0070] In another embodiment, the fatty acid having 6 to 12 carbon atoms is nonanoic acid.

[0071] The fatty acids having 6 to 12 carbon atoms will generally be present in the herbicidal composition in an amount ranging from about 1% to about 60% by weight.

[0072] When referred to as a concentrate, the herbicidal composition will typically contain greater than about 30%, greater than about 40%, or greater than about 50% by weight of fatty acids having 6 to 12 carbon atoms.

[0073] In one embodiment, the fatty acid having 6 to 12 carbon atoms is present in the herbicide composition in an amount greater than about 30% by weight, greater than about 40% by weight, or greater than about 50% by weight.

[0074] In another embodiment, the fatty acid having 6 to 12 carbon atoms is present in the herbicide composition in an amount ranging from about 30% to about 60% by weight, from about 40% to about 60% by weight, from about 50% to about 60% by weight, or from about 55% to about 60% by weight.

[0075] When referring to a spray working composition, the herbicide composition will typically contain less than about 10% by weight, less than about 5% by weight, or less than about 2% by weight of fatty acids having 6 to 12 carbon atoms.

[0076] In one embodiment, the herbicide composition comprises less than about 10% by weight, less than about 5% by weight, or less than about 2% by weight of fatty acids having 6 to 12 carbon atoms.

[0077] In another embodiment, the fatty acid having 6 to 12 carbon atoms is present in the herbicide composition in an amount ranging from about 1% to about 10% by weight, from about 1% to about 5% by weight, from about 1% to about 3% by weight, or from about 1% to about 2% by weight.

[0078] Unlike many conventional herbicide compositions, including those containing fatty acids, the herbicidal active ingredient (i.e., fatty acid) used in accordance with the present invention is provided in acid form (i.e., not as a salt), resulting in limited water solubility. Thus, the herbicidal compositions of the present invention provide the fatty acid component primarily as an emulsion. This contrasts with many conventional herbicide compositions, which typically use a highly water-soluble form of the herbicidal active ingredient, such as a metal salt or ammonium salt.

[0079] In one embodiment, the herbicide composition does not include a water-soluble metal or ammonium salt of the herbicidal active agent.

[0080] In another embodiment, the herbicide composition is provided as an emulsion, with the herbicide active ingredient being located in the oil phase of the emulsion.

[0081] The herbicidal compositions of the present invention also include an alcohol alkoxylate.

[0082] The alcohol alkoxylate component in the composition helps stabilize the composition in emulsion form.

[0083] Alcohol alkoxylates are well known nonionic surfactants derived from the alkoxylation of fatty alcohols.

[0084] The "alcohol" component or residue of an alcohol alkoxylate will generally be an alcohol containing 6 to 24 carbon atoms. The alcohol component may be linear or branched. In one embodiment, the alcohol component is linear.

[0085] In one embodiment, the alcohol alkoxylate is an alcohol alkoxylate having from 6 to 24 carbon atoms.

[0086] For the avoidance of doubt, the term "6 to 24 carbon atoms" in alcohol alkoxylates having 6 to 24 carbon atoms is intended to refer to the carbon atoms present in the alcohol residue.

[0087] The "alkoxylate" component of an alcohol alkoxylate refers to an oligomer or polymer composed of oxyalkylene units. The alkoxylate component may be branched or linear. In one embodiment, the alkoxylate component is linear.

[0088] In characterizing alcohol alkoxylates, it is sometimes convenient to refer to the number of oxyalkylene units comprising the alkoxylate component, which will generally contain from about 4 to about 12 or from 9 to about 12 oxyalkylene units.

[0089] Alcohol alkoxylates are represented by the general formula: RO((CR X R Y ) i O) j H (wherein R is alkyl having 6 to 24 carbon atoms. R X and R Y are each independently selected from hydrogen and alkyl; i is an integer ranging from 1 to 10; and j is an integer ranging from 4 to 12. X and R Y are each independently selected from hydrogen and alkyl having 1 to 6 carbon atoms, and i is an integer selected from 2, 3, and 4. When i>1, each (CR X R Y ) may be the same or different. For example, when the oxyalkylene unit is an oxyethylene unit, R X and R Yare both hydrogen, and i=2 (i.e., -O(CH2)2-). Alternatively, if the oxyalkylene unit is an oxypropylene unit, then i=2 and the first "i" R X and R Y are all hydrogen, and the second "i" R X and R Y may each be hydrogen and methyl (i.e., —OCH2CH(CH3)—).

[0090] The oxyalkylene units may be derived from alkylene oxides such as ethylene oxide, propylene oxide, or butylene oxide.

[0091] In one embodiment, the alcohol alkoxylate is an alcohol ethoxylate.

[0092] In another embodiment, the alcohol alkoxylate is an alcohol ethoxylate having 6 to 24 carbon atoms.

[0093] The alcohol alkoxylates used according to the invention may also be mixtures of different alcohol alkoxylates.

[0094] In one embodiment, the alcohol alkoxylate is a mixture of different alcohol alkoxylates.

[0095] In another embodiment, the alcohol alkoxylate comprises a mixture of an alcohol alkoxylate having 9 to 11 carbon atoms and an alcohol alkoxylate having 16 to 18 carbon atoms.

[0096] In another embodiment, the alcohol alkoxylate comprises a mixture of C9-C11 alcohol ethoxylate and C18 alcohol ethoxylate.

[0097] Without wishing to be limited by theory, it is believed that when the herbicidal composition of the present invention is formulated with a mixture of an alcohol alkoxylate having 9 to 11 carbon atoms and an alcohol alkoxylate having 16 to 18 carbon atoms, excellent stability and applicability of the composition are imparted, which is believed to result in improved applicability.

[0098] The alcohol alkoxylate will generally be present in the herbicidal composition in an amount ranging from about 0.5% to about 25% by weight.

[0099] When referred to as a concentrate, the herbicidal composition will typically contain greater than about 10%, greater than about 15%, or greater than about 20% by weight of alcohol alkoxylate.

[0100] In one embodiment, the alcohol alkoxylate is present in the herbicide composition in an amount greater than about 10% by weight, greater than about 15% by weight, or greater than about 20% by weight.

[0101] In another embodiment, the alcohol alkoxylate is present in the herbicide composition in an amount ranging from about 10% to about 25% by weight, from about 15% to about 25% by weight, or from about 20% to about 25% by weight.

[0102] When referring to a spray working composition, the herbicide composition will typically contain less than about 10%, less than about 5%, less than about 2%, or less than about 1% by weight of alcohol alkoxylate.

[0103] In one embodiment, the herbicide composition comprises less than about 10% by weight, less than about 5% by weight, less than about 2% by weight, or about 1% by weight of alcohol alkoxylate.

[0104] In another embodiment, the alcohol alkoxylate is present in the herbicide composition in an amount ranging from about 0.5% to about 10% by weight, from about 0.5% to about 5% by weight, from about 0.5% to about 3% by weight, or from about 0.5% to about 2% by weight.

[0105] When the herbicidal composition according to the invention comprises a mixture of different alcohol alkoxylates, these may be present in the same or different amounts.

[0106] In one embodiment, the herbicide composition comprises a mixture of an alcohol alkoxylate having 9 to 11 carbon atoms and an alcohol alkoxylate having 16 to 18 carbon atoms present in a weight ratio of about 1:2, respectively.

[0107] The herbicidal composition of the present invention comprises a hydrophobic liquid.

[0108] The expression "hydrophobic liquid" is intended to mean a substance that (i) is liquid at temperatures at which herbicidal compositions are normally applied, e.g., at least 5°C, 10°C, 15°C, 20°C, or 25°C, and (ii) has little or no solubility in water.

[0109] Examples of suitable hydrophobic liquids include, but are not limited to, organic solvents (such as xylene, toluene, and alkanes having 5 to 12 carbon atoms), mineral oils (such as paraffin oil), vegetable oils (such as seed oils and terpenes), petroleum fractions (such as kerosene, mineral spirits, white spirits, and Stoddard's solvent), animal oils, and combinations thereof.

[0110] Examples of suitable vegetable oils that can be used include, but are not limited to, methylated seed oils, alkylated seed oils, and the like.

[0111] In one embodiment, the hydrophobic liquid comprises one or more terpenes.

[0112] Examples of suitable terpenes that can be used include, but are not limited to, pinene, nerol, citral, menthol, limonene, carene, cineole, camphene, dipentene, and terpinolene.

[0113] In one embodiment, the hydrophobic liquid comprises one or more terpenes selected from pinene, nerol, citral, menthol, limonene, carene, cineole, camphene, dipentene, terpinolene, and combinations thereof.

[0114] In another embodiment, the hydrophobic liquid is selected from dipentene, pinene, and limonene.

[0115] Those skilled in the art will appreciate that terpenes are often derived from extracts of plant oils such as gum turpentine, pine oil, eucalyptus oil, conifer oil, tea tree oil, and combinations thereof.

[0116] In one embodiment, the herbicide composition comprises one or more of gum turpentine, pine oil, eucalyptus oil, conifer oil, tea tree oil, and combinations thereof.

[0117] In one embodiment, the herbicide composition comprises one or more terpenes derived from extracts of one or more of gum turpentine, pine oil, eucalyptus oil, conifer oil, tea tree oil, and combinations thereof.

[0118] The hydrophobic liquid will generally be present in the herbicide composition in an amount ranging from about 0.1% to about 30% by weight.

[0119] When referred to as a concentrate, the herbicide composition will typically contain greater than about 15%, greater than about 20%, or greater than about 25% by weight of the hydrophobic liquid.

[0120] In one embodiment, the hydrophobic liquid is present in the herbicide composition in an amount greater than about 15% by weight, greater than about 20% by weight, or greater than about 25% by weight.

[0121] In another embodiment, the hydrophobic liquid is present in the herbicide composition in an amount ranging from about 15% to about 30% by weight, from 20% to about 30% by weight, or from 25% to about 30% by weight.

[0122] When referring to a spray working composition, the herbicide composition will typically contain less than about 10%, less than about 5%, or less than about 2% by weight of a hydrophobic liquid.

[0123] In one embodiment, the herbicide composition comprises less than about 10% by weight, less than about 5% by weight, or less than about 2% by weight of a hydrophobic liquid.

[0124] In another embodiment, the hydrophobic liquid is present in the herbicide composition in an amount ranging from about 0.1% to about 10% by weight, from about 0.1% to about 5% by weight, from about 0.5% to about 3% by weight, or from about 0.5% to about 2% by weight.

[0125] The herbicidal composition further comprises a pH-sensitive hydrogel-forming polymer.

[0126] By "pH-sensitive hydrogel-forming polymer" is meant a polymer that forms a hydrogel in response to a change in pH.

[0127] The herbicidal composition of the present invention has an acidic pH, at which the pH-sensitive hydrogel-forming polymer is not in a hydrogel state, i.e., the herbicidal composition of the present invention has an acidic pH that does not promote hydrogel formation of the pH-sensitive hydrogel-forming polymer.

[0128] pH-sensitive hydrogel-forming polymers suitable for use in accordance with the present invention will typically contain multiple acid functional groups (such as carboxylic acids) that exist in the acid or protonated form (i.e., non-hydrogel form) at a suitable acidic pH. As the pH increases toward alkaline pH, the acid functional groups of the polymer ionize, thereby promoting hydrogel formation.

[0129] Thus, such pH-sensitive hydrogel-forming polymers used in accordance with the present invention will typically change from a non-hydrogel state at acidic pH to a hydrogel state as the pH increases.

[0130] The pH-sensitive hydrogel-forming polymer may, for example, transform into a hydrogel at a pH greater than about 4, greater than about 4.5, greater than about 5, greater than about 5.5, greater than about 6, greater than about 6.5, or greater than 7.

[0131] The pH-sensitive hydrogel-forming polymer may, for example, transform into a hydrogel at a pH in the range of about 4-8, about 4.5-7, about 5-7, or about 5.5-7.

[0132] Because pH-sensitive hydrogel-forming polymers change into hydrogels in response to an increase in pH, they can also be called alkaline hydrogel-forming polymers.

[0133] Thus, an alkaline hydrogel-forming polymer may be described as a pH-sensitive hydrogel-forming polymer that changes into a hydrogel as the pH increases toward alkaline pH.

[0134] The pH-sensitive hydrogel-forming polymer used in accordance with the present invention is not present in the herbicidal composition in hydrogel form.

[0135] The pH-sensitive hydrogel-forming polymers used in accordance with the present invention will be suitably selected to exist in a non-hydrogel form at the acidic pH of the herbicidal composition.

[0136] The pH-sensitive hydrogel-forming polymers used in accordance with the present invention may be homopolymers or copolymers.

[0137] The pH-sensitive hydrogel-forming polymers used in accordance with the present invention may contain polymerized residues of acrylic acid.

[0138] The pH-sensitive hydrogel-forming polymer may have a degree of cross-linking.

[0139] In one embodiment, the pH-sensitive hydrogel-forming polymer comprises polymerized residues of acrylic acid and optionally one or more alkyl acrylates.

[0140] Suitable pH-sensitive hydrogel-forming polymers are readily available commercially, for example, those sold under the name Carbopol® by Lubrizol.

[0141] The pH-sensitive hydrogel-forming polymer will generally be present in the herbicide composition in an amount ranging from about 0.0002% to about 0.01% by weight.

[0142] When referred to as a concentrate, the herbicide composition will typically contain greater than about 0.001%, greater than about 0.005%, or greater than about 0.008% by weight of the pH-sensitive hydrogel-forming polymer.

[0143] In one embodiment, the pH-sensitive hydrogel-forming polymer is present in the herbicide composition in an amount greater than about 0.001% by weight, greater than about 0.005% by weight, or greater than about 0.008% by weight.

[0144] In another embodiment, the pH-sensitive hydrogel-forming polymer is present in the herbicide composition in an amount ranging from about 0.001% to about 0.01% by weight, from 0.005% to about 0.01% by weight, or from 0.008% to about 0.01% by weight.

[0145] When referring to a spray working composition, the herbicide composition will typically contain less than about 0.001%, less than about 0.0006%, or less than about 0.0004% by weight of a pH-sensitive hydrogel-forming polymer.

[0146] In one embodiment, the herbicide composition comprises less than about 0.001%, less than about 0.0006%, or less than about 0.0004% by weight of a pH-sensitive hydrogel-forming polymer.

[0147] In another embodiment, the pH-sensitive hydrogel-forming polymer is present in the herbicide composition in an amount ranging from about 0.0002% to about 0.001% by weight, from about 0.0002% to about 0.0006% by weight, or from about 0.0002% to about 0.0004% by weight.

[0148] The herbicidal composition also includes fumed silica.

[0149] Fumed silica is often produced by the flame pyrolysis of silicon halide compounds or by vaporizing quartz sand at high temperatures. The resulting silica particles are very small (typically in the range of about 5-50 nm primary particle size) and have a high surface area (typically about 50-600 m). 2 / g range).

[0150] Fumed silica suitable for use in accordance with the present invention is commercially available, for example, that sold under the name XYSIL®.

[0151] In one embodiment, the fumed silica has a primary particle size of about 5 nm to about 20 nm and a surface area of ​​100 m 2 / g~about 350m 2 / g.

[0152] The fumed silica will generally be present in the herbicidal composition in an amount ranging from about 0.0003% to about 0.01% by weight.

[0153] When referred to as a concentrate, the herbicide composition will typically contain greater than about 0.001%, greater than about 0.004%, or greater than about 0.006% by weight of fumed silica.

[0154] In one embodiment, the fumed silica is present in the herbicide composition in an amount greater than about 0.001% by weight, greater than about 0.004% by weight, or greater than about 0.006% by weight.

[0155] In another embodiment, the fumed silica is present in the herbicide composition in an amount ranging from about 0.001% to about 0.01% by weight, from 0.004% to about 0.01% by weight, or from 0.006% to about 0.01% by weight.

[0156] When referring to a spray working composition, the herbicide composition will typically contain less than about 0.001%, less than about 0.0008%, or less than about 0.0006% by weight of fumed silica.

[0157] In one embodiment, the herbicide composition comprises less than about 0.001%, less than about 0.0008%, or less than about 0.0006% by weight of fumed silica.

[0158] In one embodiment, the fumed silica is present in the herbicide composition in an amount ranging from about 0.0003% to about 0.001% by weight, from about 0.0003% to about 0.0008% by weight, or from about 0.0003% to about 0.0006% by weight.

[0159] The fumed silica will generally be present in the herbicidal composition as a substantially uniform distribution or dispersion.

[0160] The herbicidal composition may further comprise one or more other ingredients that facilitate preparation and / or application of the composition.

[0161] For example, the herbicidal composition may include a pH adjuster such as an alkali metal hydroxide (e.g., sodium hydroxide).

[0162] In one embodiment, the herbicide composition comprises water in an amount ranging from about 0.1% to about 10% by weight, from about 0.1% to about 7% by weight, or from about 0.1% to about 5% by weight; a C6-C12 fatty acid in an amount ranging from about 30% to about 60% by weight, from about 40% to about 60% by weight, from about 50% to about 60% by weight, or from about 55% to about 60% by weight; an alcohol alkoxylate in an amount ranging from about 10% to about 25% by weight, from about 15% to about 25% by weight, or from about 20% to about 25% by weight; a hydrophobic liquid in an amount ranging from about 15% to about 30%, 20% to about 30%, or 25% to about 30% by weight; a pH-sensitive hydrogel-forming polymer in an amount ranging from about 0.001% to about 0.01%, 0.005% to about 0.01%, or 0.008% to about 0.01% by weight; and fumed silica in an amount ranging from about 0.001% to about 0.01%, 0.004% to about 0.01%, or 0.006% to about 0.01% by weight.

[0163] In another embodiment, the herbicide composition comprises water in an amount ranging from about 50% to about 98%, about 70% to about 98%, about 80% to about 98%, or about 85% to about 95% by weight; a C6-C12 fatty acid in an amount ranging from about 1% to about 10%, about 1% to about 5%, about 1% to about 3%, or about 1% to about 2% by weight; an alcohol alkoxylate in an amount ranging from about 0.5% to about 10%, about 0.5% to about 5%, about 0.5% to about 3%, or about 0.5% to about 2% by weight; and an alcohol alkoxylate in an amount ranging from about 0.1% to about 10% by weight. %, about 0.1 wt % to about 5 wt %, about 0.5 wt % to about 3 wt %, or about 0.5 wt % to about 2 wt % hydrophobic liquid; a pH-sensitive hydrogel-forming polymer present in the herbicide composition in an amount ranging from about 0.0002 wt % to about 0.001 wt %, about 0.0002 wt % to about 0.0006 wt %, or about 0.0002 wt % to about 0.0004 wt %; and fumed silica in an amount ranging from about 0.0003 wt % to about 0.001 wt %, about 0.0003 wt % to about 0.0008 wt %, or about 0.0003 wt % to about 0.0006 wt %.

[0164] The present invention also provides a method for preparing a herbicidal composition, comprising providing a silica-containing aqueous composition comprising water, fumed silica, and a pH-sensitive hydrogel-forming polymer.

[0165] Silica-containing aqueous compositions will generally comprise about 90% to about 99.5% by weight water, about 0.25% to about 2.5% by weight fumed silica, and about 0.25% to about 2.5% by weight pH-sensitive hydrogel-forming polymer.

[0166] In one embodiment, the silica-containing aqueous composition comprises about 90% to about 99.5% by weight water, about 0.25% to about 2.5% by weight fumed silica, and about 0.25% to about 2.5% by weight pH-sensitive hydrogel-forming polymer.

[0167] The silica-containing aqueous composition may be provided by mixing ingredients including water, fumed silica, and a pH-sensitive hydrogel-forming polymer in a container.

[0168] The silica-containing aqueous composition may also contain one or more other formulation ingredients, such as ingredients to adjust pH.

[0169] In one embodiment, the silica-containing aqueous composition has a pH that is increased to an alkaline pH by adding an alkali metal hydroxide, such as sodium hydroxide.

[0170] When a pH adjusting reagent is used, it may be added in an amount ranging from about 0.001% by weight to about 0.05% by weight.

[0171] In one embodiment, a pH adjusting reagent is used to increase the pH of the silica-containing aqueous composition.

[0172] Typically, a pH-adjusting reagent is added to the silica-containing aqueous composition to raise the pH of the composition so that the pH-sensitive hydrogel-forming polymer begins to transform into a hydrogel, i.e., the pH-adjusting reagent is used to raise the pH of the silica-containing aqueous composition to a pH that will cause the pH-sensitive hydrogel-forming polymer to form a hydrogel.

[0173] A pH adjusting reagent that increases the pH can also be referred to as an alkaline pH adjusting reagent.

[0174] In one embodiment, an alkaline pH-adjusting reagent is introduced into the silica-containing aqueous composition to raise the pH to greater than about 4, greater than about 4.5, greater than about 5, greater than about 5.5, greater than about 6, greater than about 6.5, or greater than 7.

[0175] In another embodiment, an alkaline pH adjusting reagent is added to the silica-containing aqueous composition to raise the pH to a range of about 4-8, about 4.5-7, about 5-7, or about 5.5-7.

[0176] In another embodiment, the silica-containing aqueous composition is provided at a pH that promotes hydrogel formation of the pH-sensitive hydrogel-forming polymer.

[0177] In one embodiment, the silica-containing aqueous composition is provided at a pH greater than about 4, greater than about 4.5, greater than about 5, greater than about 5.5, greater than about 6, greater than about 6.5, or greater than 7 to promote hydrogel formation of the pH-sensitive hydrogel-forming polymer.

[0178] In another embodiment, the silica-containing aqueous composition is provided at a pH in the range of about 4 to 8, about 4.5 to 7, about 5 to 7, or about 5.5 to 7 to promote hydrogel formation of the pH-sensitive hydrogel-forming polymer.

[0179] In one embodiment, the silica-containing aqueous composition has an alkaline pH.

[0180] The presence of the hydrogel thickens the silica-containing aqueous composition by promoting an increase in pH of the composition such that the pH-sensitive hydrogel-forming polymer forms a hydrogel. It has been found that increasing the viscosity of the silica-containing aqueous composition helps maintain a substantially uniform distribution of the fumed silica particles throughout the composition. That is, it has been found that the formation of the hydrogel helps minimize or prevent undesirable agglomeration of the fumed silica particles in the silica-containing aqueous composition. The resulting silica-containing aqueous composition in such a thickened state can then be mixed with other components of the herbicide composition in a manner that promotes excellent dispersion / distribution of the fumed silica particles in the herbicide composition thus prepared.

[0181] It can be appreciated that mixing the silica-containing aqueous composition in this thickened state with other components of the herbicide composition provides a final herbicide composition having an acidic pH that does not promote hydrogel formation of the pH-sensitive hydrogel-forming polymer, i.e., one or more other components of the herbicide composition provide sufficient acidity to cause the hydrogel form of the pH-sensitive hydrogel-forming polymer derived from the silica-containing aqueous composition to revert to a non-hydrogel form.

[0182] A method of preparing a herbicidal composition includes mixing the silica-containing aqueous composition thus prepared with an alcohol alkoxylate to form a liquid alcohol alkoxylate-containing composition.

[0183] Forming a "liquid" alcohol alkoxylate-containing composition means that at least the alcohol alkoxylate component of the composition is in liquid form. Because some alcohol alkoxylates suitable for use in the present invention exist as solids at room temperature, the step of mixing the aqueous silica-containing composition with the alcohol alkoxylate may require the application of heat to facilitate the liquid state of the alcohol alkoxylate used.

[0184] In one embodiment, the step of combining the silica-containing aqueous composition with the alcohol alkoxylate is carried out under heat.

[0185] Depending on the type of alcohol alkoxylate used, it may be mixed with the silica-containing aqueous composition in one or multiple stages. For example, when using a mixture of different alcohol alkoxylates, one of the alcohol alkoxylates may be mixed with the silica-containing aqueous composition, and then the other alcohol alkoxylate may be added separately.

[0186] Regardless of the method used to combine the alcohol alkoxylate with the silica-containing aqueous composition, it is important that the added alcohol alkoxylate be in a liquid state before proceeding to the next step.

[0187] Subsequently, the method for preparing a herbicidal composition comprises the step of mixing the liquid alcohol alkoxylate-containing composition thus prepared with a fatty acid having 6 to 12 carbon atoms and a hydrophobic liquid.

[0188] The fatty acid component and the hydrophobic liquid component may be mixed with the liquid alcohol alkoxylate-containing composition separately, sequentially, or as a mixture.

[0189] When adding one or more ingredients in accordance with the methods of the present invention, the composition may be agitated (eg, stirred) and / or heated to facilitate mixing and / or dispersion of the ingredients.

[0190] As described above, the herbicide composition thus prepared has an acidic pH. The acidic pH may be obtained essentially when all of the components used are mixed. Alternatively, the pH of the composition may be adjusted at any point during preparation so that the final composition has an acidic pH.

[0191] For example, a fatty acid component and / or a pH-sensitive hydrogel-forming polymer can provide an acidic pH for the composition.

[0192] Alternatively, the composition may contain / incorporate one or more other ingredients that provide or help provide an acidic pH to the composition, including, but not limited to, hydrochloric acid and acetic acid.

[0193] The components of the herbicidal composition may be mixed according to the method of the present invention in any suitable amounts to result in the concentrations of the components described herein.

[0194] Generally, the method of preparing a herbicidal composition will involve mixing the components in amounts to obtain a concentrate that is then diluted with water to obtain the required working composition for the intended use.

[0195] In one embodiment, the concentrate so produced is then diluted with a mixture of water and acetic acid to obtain the required (ie, ready-to-use) working composition for the intended application.

[0196] In one embodiment, a method for preparing a herbicide composition includes mixing together an aqueous silica-containing composition in an amount of about 1% to about 5% by weight, an alcohol alkoxylate in an amount of about 15% to about 25% by weight, a fatty acid having 6 to 12 carbon atoms in an amount of about 40% to about 60% by weight, and a hydrophobic liquid in an amount of about 20% to about 40% by weight.

[0197] In another embodiment, a method for preparing a herbicide composition includes mixing together an aqueous silica-containing composition in an amount of about 1% to about 5% by weight, an alcohol alkoxylate in an amount of about 15% to about 25% by weight, a C6-C12 fatty acid in an amount of about 40% to about 60% by weight, a hydrophobic liquid in an amount of about 20% to about 40% by weight, and acetic acid in an amount ranging from about 0.01% to about 1% by weight.

[0198] The present invention further provides herbicidal compositions made according to the methods described herein.

[0199] The present invention also provides a method for killing or retarding the growth of plants, which comprises the step of contacting the plants with a herbicidal composition according to the present invention.

[0200] The present invention further provides a method for controlling plant growth in a locus, comprising the step of applying to said locus a herbicidal composition according to the present invention.

[0201] As used herein, the expression "controlling plant growth at a locus" is intended to mean that plant growth at said locus is retarded, inhibited, or prevented. The term "locus" is intended to mean any location where plant growth can occur. For example, a locus may be an area of ​​soil on which plants can grow, or a surface on which plants can grow.

[0202] Contact of the herbicide composition of the present invention with a plant or application to a locus can be achieved by conventional means for applying a herbicide composition. For example, the herbicide composition can be directly rubbed or injected onto the plant or locus. Alternatively, the herbicide composition can be sprayed onto the plant or locus.

[0203] The present invention also provides the use of a herbicide composition according to the present invention for killing or retarding the growth of plants.The present invention further provides the use of a herbicide composition according to the present invention for controlling the growth of plants in a locus.

[0204] The use of the herbicidal compositions of the present invention can be carried out as described herein and is well known to those skilled in the art.

[0205] As used herein, the term "alkyl" as used alone or in a compound term refers to straight-chain, branched-chain, or cyclic alkyl, preferably alkyl having 1 to 20 carbon atoms, for example, alkyl having 1 to 10 carbon atoms or 1 to 6 carbon atoms. Examples of straight-chain and branched-chain alkyl include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, t-butyl, n-pentyl, 1,2-dimethylpropyl, 1,1-dimethylpropyl, hexyl, 4-methylpentyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 1,1-dimethylbutyl, 2,2-dimethylbutyl, 3,3-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 1,2,2-trimethylpropyl ... methyl, 1,1,2-trimethylpropyl, heptyl, 5-methylhexyl, 1-methylhexyl, 2,2-dimethylpentyl, 3,3-dimethylpentyl, 4,4-dimethylpentyl, 1,2-dimethylpentyl, 1,3-dimethylpentyl, 1,4-dimethylpentyl, 1,2,3-trimethylbutyl, 1,1,2-trimethylbutyl, 1,1,3-trimethylbutyl, octyl, 6-methylheptyl, 1-methylheptyl, 1,1,3,3-tetramethylbutyl, nonyl, 1-, 2-, 3-, 4-, 5-, 6-, or 7-methyloctyl, 1-, 2-, 3-, 4-, or 5-ethylheptyl, 1-, 2-, or 3-propylhexyl, decyl, 1-, 2-, 3-, 4-, 5-, 6-, 7-, and 8-methylnonyl, 1-, 2-, 3-, 4-, 5-, or 6-ethyloctyl, 1-, 2-, 3-, or 4-propylheptyl, undecyl, 1-, 2-, 3-, 4-, 5-, 6-, 7-, 8-, or 9-methyldecyl, 1-, 2-, 3-, 4-, 5-, Examples of the alkyl group include 6- or 7-ethylnonyl, 1-, 2-, 3-, 4-, or 5-propyloctyl, 1-, 2-, or 3-butylheptyl, 1-pentylhexyl, dodecyl, 1-, 2-, 3-, 4-, 5-, 6-, 7-, 8-, 9-, or 10-methylundecyl, 1-, 2-, 3-, 4-, 5-, 6-, 7-, or 8-ethyldecyl, 1-, 2-, 3-, 4-, 5-, or 6-propylnonyl, 1-, 2-, 3-, or 4-butyloctyl, and 1-2-pentylheptyl.Examples of cyclic alkyls include monocyclic or polycyclic alkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, etc. When referring to an alkyl group generally as "propyl," "butyl," etc., it is understood that any of the straight-chain, branched-chain, and cyclic isomers can be referred to as appropriate.

[0206] The invention will now be described with reference to the following non-limiting examples. [Example]

[0207] Comparative Example 1: Composition 1 A dispersion of fumed silica, water, and ethoxylated alcohol was prepared based on the formulation shown in Table 1. Nonanoic acid and pine oil were added. The solution was stirred for 15 minutes and filtered through a nylon filter. The resulting solution was stored in an airtight container.

[0208] [Table 1]

[0209] Comparative Example 2: Composition 2 An ethoxylated alcohol dispersion of fumed silica was prepared based on the formulation shown in Table 2. Nonanoic acid and pine oil were added. The solution was stirred for 15 minutes and filtered through a nylon filter. The resulting solution was stored in an airtight container.

[0210] [Table 2]

[0211] Comparative Example 3: Composition 3 A dispersion of fumed silica, water, and ethoxylated alcohol was prepared based on the formulation shown in Table 3. Nonanoic acid and dipentene were added. The solution was stirred for 15 minutes and filtered through a nylon filter. The resulting solution was stored in an airtight container.

[0212] [Table 3]

[0213] Comparative Example 4: Composition 4 A dispersion of fumed silica, water, and ethoxylated C9-11 alcohol was prepared based on the formulation shown in Table 4. The ethoxylated C18 alcohol was heated to 40°C to melt and added to the dispersion under stirring. The product was warmed to 40°C and stirred. Nonanoic acid and dipentene were added. The composition was stirred for 15 minutes, cooled to room temperature, and filtered through a nylon filter. The resulting product was stored in an airtight container.

[0214] [Table 4]

[0215] Comparative Example 5: Composition 5 A dispersion of Carbopol acrylic polymer in water and ethoxylated C9-11 alcohol was prepared based on the formulation shown in Table 5. The ethoxylated C18 alcohol was heated to 40°C to melt and added to the dispersion under stirring. The product was warmed to 40°C and stirred. Nonanoic acid and dipentene were added. The composition was stirred for 15 minutes, cooled to room temperature, and filtered through a nylon filter. The resulting product was stored in an airtight container.

[0216] [Table 5]

[0217] Example 1: Composition 6 A silica colloid composition was prepared by adding fumed silica and Carbopol acrylic polymer to water under stirring, based on the formulation shown in Table 6. Sodium hydroxide solution was added to raise the pH of the liquid to 5.5, forming a hydrogel polymer that thickened the liquid, helping to keep the silica well dispersed.

[0218] The silica colloid composition (Table 6) was added to an ethoxylated C9-11 alcohol to produce the composition shown in Table 7. The ethoxylated C18 alcohol was heated to 40°C to melt and added to the dispersion under stirring. The product was warmed to 40°C and stirred. Nonanoic acid and pure gum turpentine were added. The composition was stirred for 15 minutes, cooled to room temperature, and filtered through a nylon filter. The resulting product had an acidic pH and was stored in an airtight container.

[0219] [Table 6]

[0220] [Table 7]

[0221] Example 2: Composition 7 A silica colloid composition was prepared by adding fumed silica and Carbopol acrylic polymer to water under stirring based on the formulation shown in Table 8. Sodium hydroxide solution was added to raise the pH of the liquid to 5.5, forming a hydrogel polymer that thickened the liquid, helping to keep the silica well dispersed.

[0222] The silica colloid composition (Table 8) was added to an ethoxylated C12-14 alcohol to produce the composition shown in Table 9. The ethoxylated C18 alcohol was heated to 40°C to melt and added to the dispersion under stirring. The product was warmed to 40°C and stirred. Nonanoic acid and pure gum turpentine were added. The composition was stirred for 15 minutes, cooled to room temperature, and filtered through a nylon filter. The resulting product had an acidic pH and was stored in an airtight container.

[0223] [Table 8]

[0224] [Table 9]

[0225] Example 3: Composition 8 A silica colloid composition was prepared by adding fumed silica and Carbopol acrylic polymer to water under stirring based on the formulation shown in Table 10. Sodium hydroxide solution was added to raise the pH of the liquid to 5.5, forming a hydrogel polymer that thickened the liquid, helping to keep the silica well dispersed.

[0226] The silica colloid composition (Table 10) was added to an ethoxylated C9-11 alcohol to produce the composition shown in Table 11. The ethoxylated C18 alcohol was heated to 40°C to melt and added to the dispersion under stirring. The product was warmed to 40°C and stirred. Nonanoic acid and dipentene were added. The composition was stirred for 15 minutes, cooled to room temperature, and filtered through a nylon filter. The resulting product had an acidic pH and was stored in an airtight container.

[0227] [Table 10]

[0228] [Table 11]

[0229] Example 4: Composition 9 A low pH spray working mixture, Composition 9, was prepared based on the formulation shown in Table 12. The pH of the emulsion was reduced using acetic acid. The resulting product had an acidic pH and was stored in an airtight container.

[0230] [Table 12]

[0231] Example 5: Field application of Compositions 1 to 9 Example 5a: Field trial to evaluate the effectiveness of Composition 1 for controlling weeds in fallow soil

[0232] A field trial was conducted in Victoria to evaluate the effectiveness of Composition 1 (515.6 g / L nonanoic acid) for weed control in fallow fields. Treatments used 7 L of Composition 1 per 100 L of water, diluted to runoff, in a spray volume of 1000 L / ha. This was compared to Slasher Weed Killer (525 g / L nonanoic acid, 7 L per 100 L) in a spray volume of 1000 L / ha of water or diluted to runoff, and an untreated control.

[0233] Broadleaf weed species included plantain (Plantago major; PLANTA), marshmallow (Malva parviflora; MALPO), and sowthistle (Sonchus oleraceus; SONOL). Grass weed species included only annual bluegrass (Poa annua; POAAN).

[0234] A single foliar spray was administered to weeds at BBCH growth stages 13-15. Weed density was assessed before treatment application at 0 days after application (0 DAA) and 27 DAA. Weed brownout was assessed at 7 DAA, 17 DAA, and 27 DAA.

[0235] Composition 1 at 7 L / 100 L applied at a spray volume of 1000 L / ha or diluted to runoff resulted in significant brownout of PLANTA and MALPA and significant brownout and density reduction of SONOL and POAAN compared to untreated controls on fallow fields, with the highest rates and diluted applications to runoff generally being superior to lower rates.

[0236] When compared to Slasher Weed Killer, Composition 1 was 5-10% less effective at controlling PLANTA, MALPA, SONOL, and POAAN.

[0237] Example 5b: Field trial to evaluate the efficacy of Compositions 2, 3, and 4 for weed control in fallow soil

[0238] Field trials were conducted in Victoria to evaluate Composition 2 (nonanoic acid content: 443.0 g / L), Composition 3 (nonanoic acid content: 424.8 g / L), and Composition 4 (nonanoic acid content: 445.9 g / L) for the control of bull thistle (Cirsium vulgare), butterweed (Packera glabella), annual ryegrass (Lolium rigidum), and bermuda buttercup (Oxalis pes-caprae) in fallow fields. Compositions 2-4 were each applied as a spray mixture at 7 L per 100 L of water by boom sprayer with a flat fan nozzle at a spray volume of 1000 L / ha to runoff. Compositions 2-4 were compared to Slasher Weed Killer (nonanoic acid 525 g / L, 7 L per 100 L) applied by boom sprayer at a total spray volume of 1000 L / ha and an untreated control. All herbicide treatments were applied as a coarse spray to actively growing weeds at the 5- to 6-leaf stage for bull thistle, butterweed, and Bermuda buttercup, and at the 3- to 4-leaf stage for annual ryegrass at the time of application.

[0239] Pre-spray weed counts were performed for each species at 0 days after application (0 DAA), and viable weed counts for each species were assessed at 27 DAA. Weed brownout was assessed for each species at 7, 14, and 27 DAA.

[0240] Composition 2 (nonanoic acid content: 443.0 g / L) and Composition 3 (nonanoic acid content: 424.8 g / L) were less effective (2-5%) than Slasher Weed Killer at the same application rate. Compositions 2 and 3, when applied at rates greater than 1000 L / ha, provided broadleaf weed control, achieving 92% and 96% control of bull thistle, 82% and 85% control of butterweed, and 92% and 90% control of Bermuda buttercup compared to untreated controls. Annual ryegrass control was less effective, with good brownout at 14 DAA but 40% and 45% control at 27 DAA compared to untreated controls.

[0241] Composition 4 (nonanoic acid content: 445.9 g / L) applied at 1000 L / ha was effective in controlling broadleaf weeds, providing complete control of bull thistle, 93% control of butterweed, and 95% control of Bermuda buttercup compared to untreated controls. It was less effective in controlling annual ryegrass, with excellent brownout at 14 DAA but 60% control at 27 DAA compared to untreated controls.

[0242] Composition 4 showed a strong dose response for weed brownout. When applied at rates above 1000 L / ha, Composition 4 provided slightly less control of annual ryegrass and equivalent control of broadleaf weeds compared to Slasher Weed Killer.

[0243] Example 5c: Field trial to evaluate the effectiveness of Composition 5 for controlling weeds in fallow soil

[0244] A field trial was conducted in Victoria to evaluate the effectiveness of Composition 5 (nonanoic acid content: 445.9 g / L) for weed control in fallow fields. Treatments were applied at 7 L of Composition 5 per 100 L of water in a spray volume of 1000 L / ha. Treatments were compared to 7 L of Slasher Weed Killer (nonanoic acid 525 g / L) per 100 L of water in a spray volume of 1000 L / ha and an untreated control.

[0245] Broadleaf weed species included prickly lettuce (Lactuca serriola), hedge mustard (Sisymbrium officiale), and sawthistle (Sonchus oleraceus; SONOL). Grass weed species included only buffalo grass (Stenotaphrum secundatum).

[0246] A single foliar spray was administered to weeds at BBCH growth stages 10-12. Weed density was assessed before treatment application at 0 days after application (0 DAA) and 27 DAA. Weed brownout was assessed at 7 DAA, 17 DAA, and 27 DAA.

[0247] When 7 L / 100 L of Composition 5 (nonanoic acid content: 445.9 g / L) was applied at a spray volume of 1000 L / ha, advanced brownout and density reduction was achieved for hedge mustard (87%) and sawthistle (85%), and limited brownout and density reduction was achieved for prickly lettuce (75%) and buffalo grass (77%) compared to untreated controls.

[0248] Composition 5 was generally less effective than Slasher Weed Killer for controlling hedge mustard, sawthistle, prickly lettuce, and buffalo grass. Brownout and density reductions achieved with Slasher ranged from 93 to 96%.

[0249] Example 5d: Field trial evaluating the efficacy of compositions 6, 7, and 8 for weed control in fallow soil

[0250] A field trial was conducted in Victoria to evaluate and compare Composition 6 (nonanoic acid content: 455.7 g / L), Composition 7 (nonanoic acid content: 455.7 g / L), and Composition 8 (nonanoic acid content: 444.1 g / L) for the control of common mallow (Malva neglecta), prickly sawthistle (Sonchus asper), cape dandelion (Arctotheca calendula), and annual bluegrass (Poa annua) in fallow fields. Treatments were performed with Compositions 6-8, each applied at 5 L per 100 L of water, at a spray volume of 1000 L / ha. Treatments were applied as foliar sprays to actively growing weeds at BBCH growth stages 10-14 using a hollow cone nozzle at a spray volume of 1000 L / ha.

[0251] Treatments were compared to 7 L of Slasher Weed Killer (525 g nonanoic acid / L) per 100 L of water in a spray application volume of 1000 L / ha and an untreated control.

[0252] Weed brownout was assessed at 7 days after application (7 DAA), 14 DAA, and 28 DAA, and weed density was also assessed at 28 DAA.

[0253] Composition 6 (nonanoic acid content: 455.7 g / L) and Composition 7 (nonanoic acid content: 455.7 g / L) at 5 L per 100 L of water were at least as effective and reduced regrowth rates as Slasher Weed Killer (nonanoic acid content: 525 g / L) at 7 L per 100 L of water for controlling common mallow, prickly sawthistle, cape dandelion, and annual bluegrass. Composition 8 (nonanoic acid content: 444.1 g / L) at 5 L per 100 L of water was significantly more effective and reduced regrowth rates than Slasher Weed Killer (nonanoic acid content: 525 g / L) at 7 L per 100 L of water.

[0254] At 1000 L / ha, 5 L of Composition 8 per 100 L of water provided significant control of common mallow, prickly sowthistle, cape dandelion, and annual bluegrass. By 28 DAA, Composition 8 achieved 93% brownout of common mallow, 100% brownout of prickly sowthistle and cape dandelion, and 96% brownout of annual bluegrass.

[0255] Seven liters of Slasher Weed Killer per 100 liters of water provided good control of common mallow, prickly sawthistle, cape dandelion, and annual bluegrass. By 28 DAA, Slasher Weed Killer achieved 90% brownout of common mallow, 90% brownout of prickly sawthistle and cape dandelion, and 88% brownout of annual bluegrass.

[0256] Compositions 6 to 8 gave similar or better results than Slasher Weed Killer even when used in smaller doses.

[0257] Example 5e: Field trial to evaluate the efficacy of herbicide composition 8 for controlling weeds in fallow soil

[0258] Field trials were conducted in South Australia to evaluate Composition 8 (nonanoic acid content: 444.1 g / L) for the control of brome grass (Bromus sp.), long-fruited turnip (Brassica tournefortii), capeweed (Arctotheca calendula), and sand rocket (Diplotaxis tenuifolia). Treatments involved applying Composition 8 at 50 mL / L (water) in spray volumes of approximately 750 L / ha and 1000 L / ha. Composition 8 treatments were compared to Slasher Weed Killer (nonanoic acid content: 525 g / L) applied at 70 mL / L in a spray volume of approximately 1000 L / ha and an untreated control (UTC). Treatments were applied as foliar sprays to actively growing weeds using a wide-angle flat fan nozzle (Lechler LU120-08 nozzle).

[0259] Weed density was assessed before treatment application at 0 days after application (0 DAA) and 27 DAA. Weed brownout was assessed at 7 DAA, 17 DAA, and 27 DAA.

[0260] Composition 8 (nonanoic acid content: 444.1 g / L) applied at 50 mL / L of water provided significant control of all weeds at both evaluation time points compared to UTC. By 28 DAA, Composition 8 achieved greater than 90% brownout of all weeds at both 750 L / ha and 1000 L / ha.

[0261] Slasher Weed Killer applied at 70 mL / L provided similar weed control with greater than 90% weed brownout at an application of 1000 L / ha.

[0262] This field test demonstrated the high performance of Composition 8 as an effective herbicide for weed control in fallow fields. Compared to Slasher Weed Killer, Composition 8 performed well even at lower concentrations of the active ingredient, nonanoic acid (444.1 g / L for Composition 8 vs. 525 g / L for Slasher Weed Killer), higher dilutions (50 g / L for Composition 8 vs. 70 g / L for Slasher Weed Killer), and lower application rates (750 L / ha for Composition 8 vs. 1000 L / ha for Slasher Weed Killer). Composition 8 effectively controlled weeds at 16.65 kg / ha of nonanoic acid compared to 36.75 kg / ha for Slasher Weed Killer.

[0263] Example 5f: Field trial to evaluate the efficacy of herbicide composition 9 for controlling weeds in fallow soil

[0264] A field trial was conducted in New South Wales to evaluate and compare Composition 8 (nonanoic acid content: 444.1 g / L) and a spray mixture of Composition 9 (acetic acid content: 60.0 g / L, nonanoic acid content: 20.3 g / L) applied at 50 mL / L of water (nonanoic acid content: 21.1 g / L in the spray mixture) for the control of black grass (eragrostis setifolia) and volunteer canola (brassica napus) in fallow fields. Treatments were compared to Slasher Weed Killer (nonanoic acid content: 525 g / L) at 70 mL / L of water (nonanoic acid content: 34.3 g / L in the spray mixture) and an untreated control (UTC).

[0265] Treatments were applied by foliar spray to actively growing weeds at BBCH growth stages 10-14 using a hollow cone nozzle with spray volume up to the run-off point to simulate application in a home garden or amenity area.

[0266] Weed brownout (visual % of untreated control) was assessed at 7 DAA (days after application), and weed density (number of plants / m) was assessed at 0 and 15 DAA. 2 ) was evaluated.

[0267] Composition 8 (nonanoic acid content: 444.1 g / L) applied at 50 mL / L (water) (nonanoic acid content: 21.1 g / L in the spray mixture) significantly controlled all weeds at both evaluation times compared to UTC. Black grass brownout (% leaf area) was 94% after 3 DAA and 94% after 7 DAA. Black grass counts (counts / m) after 15 DAA were 94%. 2 ) was 6.5 compared to 20 for UTC. The brownout (% leaf area) of volunteer canola was 99% after 3 DAA and 99% after 7 DAA. The number of volunteer canola (number / m) after 15 DAA 2 ) was 0.4 compared to 7.5 for UTC.

[0268] The spray mixture of Composition 9 (acetic acid content: 60.0 g / L, nonanoic acid content: 20.3 g / L) was superior to UTC in controlling all weeds at both evaluation time points. Black grass brownout (% leaf area) was 100% after 3 DAA and 99% after 7 DAA. Black grass counts (counts / m) after 15 DAA were 100% and 99%, respectively. 2 ) was 2.5 compared to 20 for UTC. The brownout (% leaf area) of volunteer canola was 100% after 3 DAA and 100% after 7 DAA. The number of volunteer canola (number / m) after 15 DAA 2 ) was 0 compared to 7.5 in UTC.

[0269] Slasher Weed Killer (nonanoic acid 525 g / L) at 70 mL / L (water) provided moderate control of all weeds at both evaluation times compared to UTC. Black grass brownout (% leaf area) was 93% after 3 DAA and 76% after 7 DAA. Black grass counts (counts / m) after 15 DAA were significantly lower.2 ) was 12.8 compared to 20 for UTC. The brownout (% leaf area) of volunteer canola was 98% after 3 DAA and 93% after 7 DAA. The number of volunteer canola (number / m) after 15 DAA 2 ) was 0.3 compared to 7.5 for UTC.

[0270] A comparison of two spray mixtures containing only nonanoic acid showed that Composition 8 (nonanoic acid content: 444.1 g / L) applied at 50 mL / L (water) (nonanoic acid content: 21.1 g / L in spray mixture) provided numerically greater weed control than Slasher Weed Killer (nonanoic acid content: 525 g / L) applied at 70 mL / L (water) (nonanoic acid content: 34.3 g / L in spray mixture), despite the lower nonanoic acid content (21.1 g / L) compared with 34.3 g / L for Slasher. This difference in performance is particularly evident because black grass is more difficult to eradicate. The black grass counts (numbers / m) after 15 DAA were significantly higher. 2 ) was 6.5 for Composition 8, compared to 12.8 for Slasher Weed Killer and 20 for UTC.

[0271] The spray mix of Composition 9 (acetic acid content: 60.0 g / L, nonanoic acid content: 20.3 g / L) provided superior control of all weeds compared to the high-performing Composition 8 (nonanoic acid content: 444.1 g / L) applied at 50 mL / L of water (nonanoic acid content: 21.1 g / L in the spray mix) and Slasher Weed Killer (nonanoic acid content: 525 g / L) applied at 70 mL / L of water (nonanoic acid content: 34.3 g / L in the spray mix). The difference is particularly evident because black grass is more difficult to eradicate. The black grass counts (counts / m) after 15 DAA were significantly higher. 2 ) was 6.5 for composition 8, 12.8 for Slasher Weed Killer, and 20 for UTC, compared to 2.5 for composition 9.

[0272] The reference herein to any prior publication (or information derived therefrom) or any known matter is not, and should not be considered, an admission or acknowledgement, or in any way an indication that the prior publication (or information derived therefrom) or known matter is part of the common general knowledge in the field to which this specification pertains.

[0273] Throughout this specification and the claims that follow, unless the context requires otherwise, the word "comprise" and variations such as "comprises" and "comprising" will be understood to mean the inclusion of a stated integer or step or group of integers or steps, but not the exclusion of any other integer or step or group of integers or steps.

Claims

1. 1. A herbicide composition having an acidic pH, comprising: a hydrophobic liquid comprising water, a fatty acid having 6 to 12 carbon atoms, an alcohol alkoxylate having 6 to 24 carbon atoms, one or more terpenes, a pH-sensitive hydrogel-forming polymer comprising polymerized residues of acrylic acid, and fumed silica; the pH of the composition does not promote hydrogel formation of the pH-sensitive hydrogel-forming polymer; Herbicidal compositions.

2. 10. The herbicidal composition of claim 1, wherein water is present in an amount ranging from 0.1% to 10% by weight.

3. 10. The herbicidal composition of claim 1, wherein water is present in an amount ranging from 50% to 98% by weight.

4. 10. The herbicidal composition of claim 1, wherein water is present in an amount ranging from 0.1% to 10% by weight, the fatty acid having 6 to 12 carbon atoms is present in an amount ranging from 30% to 60% by weight, the alcohol alkoxylate having 6 to 24 carbon atoms is present in an amount ranging from 10% to 25% by weight, the hydrophobic liquid comprising one or more terpenes is present in an amount ranging from 15% to 30% by weight, the pH-sensitive hydrogel-forming polymer comprising polymerized residues of acrylic acid is present in an amount ranging from 0.001% to 0.01% by weight, and the fumed silica is present in an amount ranging from 0.001% to 0.01% by weight.

5. 10. The herbicidal composition of claim 1, wherein water is present in an amount ranging from 50% to 98% by weight, the fatty acid having 6 to 12 carbon atoms is present in an amount ranging from 1% to 10% by weight, the alcohol alkoxylate having 6 to 24 carbon atoms is present in an amount ranging from 0.5% to 10% by weight, the hydrophobic liquid comprising one or more terpenes is present in an amount ranging from 0.1% to 10% by weight, the pH-sensitive hydrogel-forming polymer comprising polymerized residues of acrylic acid is present in an amount ranging from 0.0002% to 0.001% by weight, and the fumed silica is present in an amount ranging from 0.0003% to 0.001% by weight.

6. 2. The herbicidal composition according to claim 1, wherein the alcohol alkoxylate having 6 to 24 carbon atoms comprises a mixture of an alcohol alkoxylate having 9 to 11 carbon atoms and an alcohol alkoxylate having 16 to 18 carbon atoms.

7. 2. The herbicidal composition according to claim 1, wherein the fatty acid having 6 to 12 carbon atoms is selected from caproic acid, enanthic acid, caprylic acid, nonanoic acid, capric acid, undecylic acid, lauric acid, and sebacic acid.

8. 2. The herbicidal composition according to claim 1, wherein the fatty acid having 6 to 12 carbon atoms comprises nonanoic acid.

9. 2. The herbicide composition of claim 1, wherein the terpenes comprise one or more selected from pinene, nerol, citral, menthol, limonene, carene, cineole, camphene, dipentene, terpinolene, and combinations thereof.

10. 10. The herbicidal composition of claim 1, further comprising acetic acid.

11. A method for killing or retarding the growth of plants, comprising the step of contacting the plants with the herbicidal composition according to any one of claims 1 to 10.

12. providing a silica-containing aqueous composition comprising water, fumed silica, and a pH-sensitive hydrogel-forming polymer comprising polymerized residues of acrylic acid; mixing the silica-containing aqueous composition with an alcohol alkoxylate having 6 to 24 carbon atoms to form a liquid alcohol alkoxylate-containing composition; and mixing the liquid alcohol alkoxylate-containing composition with a hydrophobic liquid containing a fatty acid having 6 to 12 carbon atoms and one or more terpenes to form a herbicide composition.

1. A method for preparing a herbicidal composition comprising: The herbicide composition thus prepared has an acidic pH that does not promote hydrogel formation of the pH-sensitive hydrogel-forming polymer. Methods for preparing herbicidal compositions.

13. 13. The method of claim 12, wherein the silica-containing aqueous composition is provided at a pH that promotes hydrogel formation of the pH-sensitive hydrogel-forming polymer.

14. The method according to claim 12 or 13, wherein the fatty acid having 6 to 12 carbon atoms includes nonanoic acid.

15. 14. The method of claim 12 or 13, wherein the prepared herbicide composition is mixed with water and acetic acid to obtain a ready-to-use herbicide composition having an acidic pH that does not promote hydrogel formation of the pH-sensitive hydrogel-forming polymer.

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