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1. WO1997041730 - CONCENTRES HERBICIDES DE TYPE NOUVEAU

Note: Texte fondé sur des processus automatiques de reconnaissance optique de caractères. Seule la version PDF a une valeur juridique

[ EN ]

DESCRIPTION

NOVEL HERBICIDALLY-ACTIVE CONCENTRATES

Background of the Invention
Weeds cost farmers billions of dollars annually in crop losses and in the expense of keeping weeds under control. Much of the cost of intertillage of row crops, maintenance of fallow, seedbed preparation, and seed cleaning is chargeable to weed control. Suppression of weeds along highways and railroad πght-of-ways, and in irrigation ditches, navigation channels, yards, parks, grounds, and home gardens also is expensive Ragweed pollen is the source of annual periodic distress to several million hayfever sufferers Poison ivy, poison oak, poison sumac, nettles, thistles, sandburs, and puncturevine also bπng pam to millions Weeds also serve as hosts for other crop diseases as well as for insect pests
The losses caused by weeds in agricultural production environments include decrease in crop yield, reduced crop quality, increased irrigation costs, increased harvesting costs, decreased land value, injury to livestock, and crop damage from insects and diseases harbored by the weeds.
Chemical herbicides have provided an effective method of weed control; however, the public has become concerned about the amount of residual chemicals which might be found in food, ground water, and the environment Stringent new restrictions on the use of herbicides and the elimination of some effective herbicides from the market place could limit economical and effective options for controlling costly weeds. Additionally, the visually apparent phytotoxic effects of some systemic herbicides appear very slowly on the target weeds, so pesticide users often seek methods by which the apparent speed of action of the herbicide is increased.
Recently, fatty acids and salts of fatty acids have been used commercially as pesticides and herbicides. Compositions having excellent pesticidal properties which exploit fatty acid salts are available commercially under the trademark SAFER INSECTICIDAL SOAP. A herbicidally-active composition utilizing partially saponified fatty acids as the active ingredient is sold under the trademark SHARPSHOOTER. These fatty acid compositions have no known long-term environmental effects.
U.S. Patent No. 5,196,044 concerns novel compositions and methods for selective or non-selective control of plants More specifically, that patent pertains to the application to weeds of a combination of certain chemical herbicides and one or more fatty acids, or their salts, which results in the effective control of a broad range of plants U.S. Patent Nos. 2,626,862; 4,975,110; and 5,035,741 describe certain fatty acid compositions useful as herbicides. These documents mention the use of salts of fatty acids. Specifically, "saponified" fatty acids are discussed. Saponifϊcation means "to form the sodium or potassium salt of a fatty acid." It stems from the soap making industry where animal fats (esters of fatty acids and glycerol) are hydrolyzed in sodium or potassium hydroxide to form the sodium or potassium salts of the fatty acids (soaps) and free glycerol Mixing sodium or potassium hydroxide with a free fatty acid to form the salt is also called saponifϊcation "Complete" saponification means that 100% of the fatty acid is converted to the salt; "partial" sapomfication means that <100% of the acid is converted to the salt. This means there is a mixture of the free fatty acid and the fatty acid salt. U.S. Patent No. 4,975,110 indicates that the free fatty acid form is preferable to fatty acid salts for use as a herbicide. These patents also teach that the proper formulation of a fatty acid herbicide requires one or more surfactants.
In the past, fatty acid esters have been used as chemical pinching agents for the inhibition of bud growth of certam plants (Tso, T.C., G.L. Steffens, M.E. Engelhaupt [1965] J. Agr. Food Chem. 13(1):78-81; Sill, L.Z., P.V. Nelson [1970] J. Amer. Soc. Hort. Sci. 95(3):270- 273). Herbicidally-active fatty acid esters are descπbed m U.S. Patent No. 5,284,819, which is incorporated herein by reference.
PCT application No. WO93/09669 discloses fatty acid amine salts with herbicidal activity.
There is a great need for novel weed control methods which reduce the amount of chemical herbicide necessary to obtain acceptable levels of weed control. Especially advantageous would be herbicidally-active emulsifiable concentrates, rather than "ready to use" mixtures. Practitioners in the herbicide art often expeπence difficulty in formulating or obtaining mixtures of herbicides. There are vaπous obstacles to success, including chemical incompatibility of the component herbicides. Such incompatibility is especially problematic with concentrates, because the herbicidal components must, by definition, be present in high concentrations. While it is often difficult to combine two different herbicides without obtaining chemical antagonism when the components are at "ready to use" concentrations, it is even more difficult to avoid chemical antagonism, undesirable chemical interactions, or incompatibilities when the components are combined at very high concentrations Brief Summary of the Invention
The subject invention provides novel herbicidally-active concentrates and methods of formulating the same. The compositions of the subject invention are highly advantageous because they provide thermostable concentrated solutions of immiscible components.
In a preferred embodiment, the concentrates of the subject invention comprise a glyphosate compound and a fatty acid compound. The fatty acid compound may be in the acid form or a lipophilic fatty acid derivative. Such derivatives include esters and amine salts. In a preferred embodiment, the glyphosate compound is the isopropylamine salt, and the fatty acid compound is an ester. In a preferred embodiment, the fatty acid ester component is an ethylene glycol pelargonate. The herbicidal concentrates of the subject invention comprise, in addition to the glyphosate compound and the fatty acid compound, a suitable surfactant and solvent. Although the fatty acid component is preferably an ester, mixtures of fatty acid compounds may be used according to the subject invention.
The fatty acid compound of the subject invention can be represented by the following formula:
o
II
RιY1Y2CZR2XιX2
wherein
Z = O, N, or S
R, = C5 to C12 saturated or unsaturated hydrocarbon, or an epoxide, or
cyclopropane thereof
Y, = H, C1-C5 hydrocarbon, or hydroxyl at any position along R,
Y2 = H, C1-C5 hydrocarbon, or hydroxyl at any position along R,
R2 = H; Cl to CIO saturated or unsaturated hydrocarbon; or a salt-forming
moiety chosen from the group consisting of aliphatic amines which
form cationic aliphatic ammonium compounds
X, = H, hydroxyl, or Cl to C3 hydrocarbon at any position along R2
X2 = H, hydroxyl, or Cl to C3 hydrocarbon at any position along R2.
If Z is N, then of course there would be two R2 groups. If R2 is H, then of course there would be no X, or X2.
Specifically exemplified herein are saturated lipophilic fatty acid compounds of length C6 to C13 (R, = C5 to C12). In a preferred embodiment of the subject invention R2 is the mono-glycol ester of pelargonic (C9) acid.

Advantages provided by concentrates of the subject invention include reduced packaging costs and increased stability, longer shelf life, and ease of storage. The concentrates are easy to dilute for use at a desired concentration. Thus, an additional advantage of the concentrates descπbed herein is the reduction m the time and effort needed to formulate the desired end product. It should be noted that the advantages of the subject invention mclude all of the advantages provided by using these active ingredients in combination; the advantageous combination of the subject active ingredients, glyphosate and fatty acid compounds, can reduce the amount of harmful chemical herbicides that are introduced mto the environment Numerous other advantages of the subject mvention will become apparent to those skilled in the art, in light of the following disclosure.

Detailed Disclosure of the Invention
The subject invention concerns herbicidally-active concentrates. The concentrates of the subject invention compπse a two component active ingredient system The first active component compnses a glyphosate compound. The second active component compnses a fatty acid compound. The fatty acid compound is lipophilic and may be the free fatty acid or, preferably, an ester or aliphatic amine salt.
Advantageously, the subject invention provides a concentrated, thermodynamically stable solution compnsing two normally immiscible components, the water-insoluble fatty acid component and a highly polar solution of a glyphosate salt. Surpnsmgly, a normally incompatible system such as descπbed herein may be prepared according to the subject invention as a stable microemulsion. The concentrate may have, for example, from about 1 to about 5 lbs. of active ingredient per gallon. As used herein, the concentrations of active ingredients are expressed as acid equivalents of each component.
In a preferred embodiment, the glyphosate compound is present as the isopropyl amine salt. Other glyphosate compounds can be used according to the subject invention. The skilled artisan will appreciate that glyphosate can be any one of a number of salts of the acid compound

The fatty acid compound used according to the subject invention can be unsubstituted, or substituted, saturated, or unsaturated, lipophilic fatty acid compounds of about C6 to about C 13. Specifically exemplified are fatty acids of length C9 to C 12, as typified by, but not limited to, decanoic and pelargonic acids In a particularly preferred embodiment, the fatty acid compound is the ethylene glycol pelargonate ester. The fatty acid component of the subject invention may be a single fatty acid compound or a mixture of two or more fatty acid compounds. In a preferred embodiment, the fatty acid carbon chain is saturated For example, ethylene glycol pelargonate is available from Henkel (product no. EMM/33095); this product consists of approximately 65-75% monoester and 25-35% diester. Other mixtures are available. As used herein, "lipophilic fatty acid compounds" refers to fatty acids and their derivatives which have a solubility in water which is similar to the solubility of the compounds specifically exemplified herein.
Although esters are preferred, other lipophilic fatty acid compounds can be used Aliphatic amme salts of fatty acid which can be used according to the subject invention are those which form lipophilic compounds. R2 can be an aliphatic amine or other compound which would form a lipophilic fatty acid compound Aliphatic amines which may be used to form the fatty acid compound useful according to the subject invention can be selected from the group including, but not limited to, tryptamine, n-amylamine, ethanolamine, n-hexylamine, sec-butylamine, or isopropylamine. A preferred example is isopropylamine. Other organic amines (or non-amme organic bases) can be used according to the subject invention so long as these other bases have comparable attributes of base strength and polaπty. Further examples of the compounds which can be used according to the subject invention include, but are not limited to, the alkyl amines, alkylene amines and alkanol amines containing not more than 2 amme groups, such as methylamme, ethylamine, n-propylamine, isopropylamine, «-butylamme, isobutylamine, .seobutylamine, n-amylamme, isoamylamine, hexylamine, heptylamme, octylamine, nonylamine, decylamme, undecylamme, dodecylamme, tridecylamme, tetradecyclamine, pentadecylamine, hexadecylamme, heptadecylamme, octadecylamine, methylethylamine, methyhsopropylamme, methylhexylamine, methylnonylamine, methylpentadecylamine, methyloctadecylamine, ethylbutylamme, ethylheptylamine, ethyloctylamme, hexylheptylamme, hexyloctylamine, dimethylamine, diethylamine, dι-H-propylamιne, diisopropylamine, dι-«-amylamvne, dusoamylamine, dihexylamine, diheptylamme, dioctylamme, tπmethylamine, tnethylamine, tn-M-propylamine, tπisopropylamine, tπ-n-butylamine, tπisobutylamine, tπ-Λec-butylamine, tπ-n-amylamine, ethanolamine, n-propanolamine, isopropanolamine, diethanolamine, N,N-dιethylethanolamιne, N-ethylpropanolamine, N-butylethanolamine, allylamine, «-butenyl-2 -amine, n-pentenyl-2-amιne, «-hexenyl-2-amme, and propylenediamme, pπmary aryl amines such as aniline, methoxyanilme, ethoxyamhne, o,m,p-toluιdιne, phenylenediamme, 2,4,6-tπbromoanιhne, benzidme, naphthylamme, o,m,p-chloroanιlme, and the like; and heterocyclic amines such as pyπdine, morphohne, pipeπdine, pyrrolidine, mdolirie, azepme and the like. Further, the compounds formed according to the subject mvention can be, for example, from the group consisting of monoalkylammonium, dialkylammonium, tπalkylammonium, monoalkenylammomum, dialkenylammomum, tnalkenylammomum, monoaklynylammonium, dialkynylammomum, tnalkynylammonium, monoalkanolammonium, dialkanolammomum, and tπalkanolammomum.
The two-component active ingredient composition of the subject invention can be prepared by combining glyphosate and a fatty acid compound together with a non-ionic, anionic, or cationic surfactant. As used herein, reference to "glyphosate," or a "glyphosate compound," includes the vaπous herbicidal forms of this product. Aqueous formulations of glyphosate can contain one or more salts, such as an alkylamine, for example, isopropylammonium salt, the ammonium salt, the trimethylsulfonium salt, or an alkali metal, for example potassium or sodium, salt of glyphosate. Additional salts are described in U.S. Patent No 4,405,531, which is incorporated herein by reference.
The fatty acid component may be an acid, ester, or a lipophilic amme salt to which the glyphosate component may be added. Conversion to a microemulsion can then be made by the addition of a surfactant, typically an alkyl or aryl ethoxylate dissolved in a co-solvent. Other surfactants having similar surface active properties may be used in the practice of the subject invention. Typically, use of a surfactant together with a co-solvent facilitates phase changes resulting in a microemulsion. The microemulsion will preferably compπse micelles of approximately lOOOA or smaller. If a co-solvent is used, it can be, for example, an alcohol having from about 1 to about 8 carbons. Examples of suitable alcohols include methyl, propyl, and octyl alcohols. Water can be provided for the microemulsion by the glyphosate solution. If an ethoxylated surfactant is used, the degree of ethoxylation of the surfactant can be vaned by one skilled in the art in accordance with the teachings provided herein. One could choose, for example, a surfactant having from about 5 moles to about 15 moles or more of ethoxylation.
Various concentrations of the components of the subject emulsifiable herbicide concentrates can be used according to the subject invention. For example, approximately 0.05 to 2.0 lbs. of the glyphosate component can be used per gallon of concentrate. Preferably, about 0.25 to about 1.5 lbs., and more preferably about 1.0 lb. of the glyphosate component will be used per gallon of concentrate. Approximately 0.5 to 6.0 lbs. of fatty acid ester can be used per gallon of concentrate. Preferably, about 1 lb. to about 5 lbs., and more preferably about 4 lbs , of the fatty acid ester will be used per gallon of concentrate. Typically, about 0.25 to 2.0 lbs of surfactant per gallon of concentrate can be added to emulsify the active components Preferably, about 0.5 to about 1.5 lbs., and more preferably about 1.0 lb. of surfactant will be used per gallon of concentrate. Duπng the formation of the microemulsion, 0 to 2.5 lbs. of a co-solvent can be added per gallon of the final concentrate volume. Preferably, about 1 to about 2 lbs. of co-solvent, and more preferably about 1.5 lbs. of co-solvent, will be used per gallon of concentrate. In each gallon of the concentrate, there will be approximately 1 to 5 lbs. of active ingredients (total weight of the fatty acid compound and glyphosate compound).
Thus, the active ingredients of the concentrates of the subject invention will typically comprise about 12% to about 85% of the concentrates. The fatty acid compound itself can compπse up to about 80% of the final composition. The surfactant will typically be present in the amount of about 2% to about 20% of the final mixture. The co-solvent will typically range from about 0% to about 30% of the final composition. The remainder of the subject emulsifiable concentrates can be comprised of water as the base solvent. Other polar base solvents can be used. The ratio of fatty acid compound to glyphosate compound can range from about 1 1 to about 50:1
Appropriate concentrations for the components can readily be determined for a particular use by a person skilled in the art having the guidance and specific examples provided herein.
In light of the foregoing, it should be clear that vaπous amounts of the ingredients of the subject compositions can be combined in the successful practice of the subject invention Following are examples of possible combinations of the components of the subject compositions: 0 5 1b of the glyphosate component, 0.5 lb of the fatty acid component, and 0.25 lbs of the surfactant solution can be combined, with the water being contπbuted by the glyphosate, to form one gallon of an embodiment of the subject composition As another example, 0.33 lbs. of the glyphosate component, 4.16 lbs. of the fatty acid component, and 1 lb of the surfactant can be combined, and 2 lbs. of the co-solvent can be added, with water as the base solvent, to form one gallon of an embodiment of the subject composition. As a further example, 1 lb. of the glyphosate component, 1 lb. of the fatty acid component, and 1 lb. of the surfactant can be combined, and 1 lb. of the co-solvent can be added, with water as the base solvent, to form one gallon of an embodiment of the subject composition. As a still further example, 1.5 lbs. of the glyphosate component, 1.5 lbs. of the fatty acid component, and I 5 lbs. of the surfactant can be combined, and 1.5 lbs. of the co-solvent can be added, with water as the base solvent, to form one gallon of an embodiment of the subject composition. Yet another example would be to combine 1.5 lbs of the glyphosate component, 3 lbs. of the fatty acid component, with 1 lb. of the surfactant, and 2 lbs. of the co-solvent can be added, with additional water as would be needed, depending on the concentrations of the available component sources, to form one gallon of an embodiment of the subject composition.

In order to achieve the desired amounts of the individual components of the subject invention m light of the acceptable concentration ranges as discussed above, the skilled artisan will know that the amount of commercially available product will be adjusted depending on the concentration at which the desired component is formulated m the source product For example, "ROUNDUP" is available as a 41% glyphosate solution m water with surfactant. "RODEO" is available as a 53.8% glyphosate formulation without surfactant. Thus, if either of these commercially available products is to be used as the source of glyphosate, the amount of commercially available product added will be according to the amount of glyphosate that is present in the starting product.

Materials and Methods
Synthesis of ethylene glvcol monopelargonate. 51.5 g pelargonic acid and 51 g ethylene glycol were dissolved in 200 ml of dichloromethane, and 20 drops of H2S04 were added to the mixture. It was stored at room temperature for 6 days. After 6 days, 150 ml of 0.1 N NaOH was added to the reaction mixture which was then vigorously shaken. The dichloromethane layer

(lower layer) was collected and washed with saturated NaCl solution.
After drying on Na2S04, the chloroform layer was evaporated. Remaining oil (38 g) was subjected to vacuum distillation yielding 34 8 g (yield 53.8%) of ethylene glycol monopelargonate (b.p. 135-137°C (7 mm Hg)).
Synthesis of the esters of C. to CH acids.
(a) Hexanoic acid (C6 acid) and heptanoic acid (C7 acid) — each of 100 mmol of Q and C7 acids were added to 300 mmol of ethylene glycol. Several drops of H2S04 were added to the mixture and stored at room temperature for 9 days. Isolation of the esters were earned out using the same procedure as that to isolate ethylene glycol monopelargonate.
(b) Decanoic acid (C)0 acid), dodecanoic acid (C12 acid), and tetradecanoic acid (C,4 acid) — each of 100 mmol of C10, C12 and C,4 acids were dissolved in 50 ml dichloromethane, and 300 mmol of ethylene glycol was added to the solutions. Several drops of H2S04 were added to the mixture. The reaction mixtures were stored at room temperature for 9 days. Isolation of the esters were earned out using the same procedure as that to isolate ethylene glycol monopelargonate. Distillations were not undertaken.
Synthesis of fattv acid amme compounds An aqueous formulation of the isopropylamine deπvative of pelargonic (nonanoic) acid was prepared. The pelargonic acid was obtained as "EMERY 1202" from Quantum Chemical Corporation, Cincinnati, Ohio, and is a mixture of normal fatty acids of chain length 8, 9, and 10, with C9 being predominant Vanous aqueous formulations were prepared with up to 20% active ingredient as the fatty acid and up to 6% isopropylamine, with the balance being water. The requisite amount of pelargonic acid was dispensed into an appropπate mixing vessel and the mixing initiated. The requisite amount of water was added to the acid and the acid dispersed into the water by mixing, thus forming a cloudy, unstable dispersion. Isopropylamine (ALDRICH Chemical Company, Milwaukee, WI) was added slowly, with continuous mixing, in sufficient quantity to bnng the pH of the formulation to approximately 7.4-7.8. At this approximate pH the cloudy dispersion became translucent as the fatty acid isopropylamine compound became water soluble. By employing the proportions of acid to isopropylamine descnbed here, formulations of up to about 75% fatty acid can be prepared by this method.

Following are examples which illustrate procedures for practicing the invention. The examples provided herein should not be construed as limiting. All percentages are by weight and all solvent mixture proportions are by volume unless otherwise noted.

Example 1 — Preparation of Emulsifiable Concentrate
Two to three pounds of a glyphosate compound can be combined by moderate mixing with five to six pounds of a fatty acid compound and three to five pounds of a co-solvent solution of a nonionic surfactant. The ratio of co-solvent to surfactant can be vaπed depending on, for example, the number of moles of ethoxylation of the surfactant. For example, the co-solvent to surfactant ratio can vary from about 1: 1 to about 10.1. Ratios of fatty acid to glyphosate used to prepare the stable concentrates of the subject invention can range from about 1 : 1 to about 50: 1. The resulting microemulsion can be emulsified with water, which results in a typical colloidal emulsion. By varying the amount of component products, as discussed above, concentrates can readily be produced that contain between about 1 and about 5 lbs. total active ingredient/gallon of concentrate.

Example 2 - Use of Concentrates
The concentrates prepared as descnbed herein can be diluted to a desired concentration by adding water or other appropnate solvent to the concentrates. The composition resulting from the dilution of the concentrate is suitable for application to plants, or the site of plants, via any number of techniques that are known in the art. Suitable application techniques include backpack spraying It should be understood that the examples and embodiments descnbed herein are for illustrative purposes only and that vaπous modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spint and purview of this application and the scope of the appended claims