Classifications

• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
  • A01N25/00—Biocides, pest repellants or attractants, or plant growth regulators, characterised by their forms, or by their non-active ingredients or by their methods of application, e.g. seed treatment or sequential application; Substances for reducing the noxious effect of the active ingredients to organisms other than pests
  • A01N25/02—Biocides, pest repellants or attractants, or plant growth regulators, characterised by their forms, or by their non-active ingredients or by their methods of application, e.g. seed treatment or sequential application; Substances for reducing the noxious effect of the active ingredients to organisms other than pests containing liquids as carriers, diluents or solvents
  • A01N25/04—Dispersions, emulsions, suspoemulsions, suspension concentrates or gels
• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
  • A01N25/00—Biocides, pest repellants or attractants, or plant growth regulators, characterised by their forms, or by their non-active ingredients or by their methods of application, e.g. seed treatment or sequential application; Substances for reducing the noxious effect of the active ingredients to organisms other than pests
  • A01N25/02—Biocides, pest repellants or attractants, or plant growth regulators, characterised by their forms, or by their non-active ingredients or by their methods of application, e.g. seed treatment or sequential application; Substances for reducing the noxious effect of the active ingredients to organisms other than pests containing liquids as carriers, diluents or solvents

Definitions

• the present invention relates to the preparation of concentrates of biologically active substances that may be dispersed in water for purposes of application thereof. More specifically, the invention refers to a method for the provision in nanometric scale of particles of water insoluble or almost water insoluble active ingredients that may be applied as active ingredients of agricultural defensives.
• biocides comprising among others, herbicides, fungicides and insecticides
• aqueous solution or dispersion by means of spraying or pulverization.
• active ingredients used as biocides are insoluble or poorly soluble in water, such fact hindering the preparation of stable formulations which upon the dilution thereof in water might result in a product both economic and effective.
• the insoluble active ingredients can be formulated in various forms, such as: concentrated suspensions (dispersion of solids in liquids, that are diluted with water to be applied); emulsionable concentrates (concentrated solutions that upon being diluted for application, form an emulsion), wettables (powders easily dispersible in water), water dispersible granules, among other forms.
• concentrated suspensions disersion of solids in liquids, that are diluted with water to be applied
• emulsionable concentrates concentrated solutions that upon being diluted for application, form an emulsion
• wettables wettables easily dispersible in water
• water dispersible granules among other forms.
• solvents and surfactants which account for the solubilization of the active ingredient in the concentrates and for the stabilization of the dispersions and ease of application thereof.
• these formulations when in the condition intended for application thereof to dilution in water, exhibit particle sizes in the micrometric scale (10-6m), such dimension scale limiting
• the stability of the concentrates is related to the obtainment of formulations without turbidity, crystallization, phase separation or decomposition of the active ingredient, and the stability of the aqueous dispersions is related to the time during which the same can be used for crop spraying without visually noticeable separation of the phases or decomposition of the active ingredient.
• Patent application No. BR PI 06028919-5 discusses this difficulty and describes emulsionable concentrates both stable and capable of providing emulsions upon proper water dilution for application, however exhibiting particles of nanometric scale upon the dispersion in water.
• Patent application No. WO 92/10937 describes a concentrate comprising a solid water-insoluble active which is solubilized in a dispersing medium comprised of water miscible solvents and surfactants, however this composition is different from that of the present invention in terms of the absence of need to use miscible solvents, the different nature of the surfactants, and in the fact that the present invention allows the use of water in the composition, as will be described in the invention. Additionally, the results of the formulations discussed in patent application No. WO 92/10937 are described to have a particle size of less than 1 micron, while the results achieved based on the instant patent application reach values of less than 400 nm, a situation in which the benefits of the nano-dispersion become fully available.
• PI 9101691-6 and BR PI 9404456-2 there are disclosed formulations for various pesticides, among which the triazoles, using di-styryl-phenyl-tri-glycol ethers, fatty acid amides and phosphoric acid alkyl ether derivatives, for the purpose of warranting the stability of the formulations and inhibiting the formation of crystals.
• These formulations also generate micrometric-sized dispersions, and use fatty acid amides as solvents to formulate emulsionable concentrates.
• the existing agrochemical formulations have particle sizes varying between 4 and 12 microns, and the typical particle size distribution thereof can be seen in Figure 1.
• the agronomical performance may be improved with the reduction of the effective size of these particles. They further entail problems associated to the clogging of filters and application nozzles arising fro the formation of crystals and/or lumps.
• One other aspect begging improvement is the reduction of phytotoxicity, a problem that is frequently correlated with a decrease in productivity of the crop.
• nanometric materials might provide a significant contribution towards improving the application performance. At nanometric sizes it is possible to increase the solubility of the active ingredient in water, consequently enhancing the effectiveness of the biocide used, in addition to the benefits of increased stability and longer useful life of these dispersions.
• a first object of the present invention consists in the provision of a solubilizing medium for biocide actives, capable of providing stable concentrates, and upon the dilution thereof in water, achieving a dispersion with a particle size distribution of less than 400 nm, and more specifically, with a mean particle size of the order of 180 nm.
• the reduction of the particle size of the dispersion enhances the effect of the active ingredient, rendering possible a decrease of the application dosage, a lesser number of applications or an improved agronomical effectiveness.
• One other object of the invention consists in the provision of a method for the preparation of these concentrates and their dispersions that may be able to afford an economy of the amount of power used in comparison with the processes known from the prior art.
• One other object of the invention consists in the provision of a method able to be applied to biocides either in solid form or in liquid for at ambient temperature.
• Fig. 1 is a graphic representation of the particle size distribution of dispersions of the tebuconazole prepared from formulations of emulsionable concentrates.
• Fig. 2 is a graphic representation of the particle size distribution of composition A, showing nanometric particles of approximately 180 nanometers using Tebuconazole as the active ingredient.
• Fig. 3 is a graphic representation of the particle size distribution of the dispersion of composition B, showing nanometric particles of approximately 190 nanometers using Tebuconazole as the active ingredient.
• Fig. 4 is a graphic representation of the particle size distribution of the dispersion of composition C, showing nanometric particles of approximately 190 nanometers using Tebuconazole as the active ingredient.
• Fig. 5 is a graphic representation of the particle size distribution of the dispersion of composition D, showing nanometric particles of approximately 190 nanometers using Tebuconazole as the active ingredient.
• Fig. 6 is a graphic representation of the particle size distribution of the dispersion of composition E, showing nanometric particles of approximately 190 nanometers using Flutriafol as the active ingredient.
• Fig. 7 is a graphic comparison of the X-Ray Diffraction pattern of a solid sample of Tebuconazole (peaks 11, 12, 13 and 14) with that of Concentrate A of the set of examples (amorphous halo - curve 15).
• the solubilizing medium comprises at least one surfactant, optionally a water- soluble organic substance used as a carrier, and optionally water.
• the concentration of the water soluble organic compound is comprehended within a range of concentration from zero to 80% w/w of the formulation, the total concentration of surfactants is comprised in a range of from 10 to 95% w/w of the formulation, the concentration of the active ingredient may be of up to 40% w/w of the total formulation.
• the use of water is also optional, and the same can be used up to the limit of 20% w/w of the formulation.
• the water soluble organic substance or carrier comprises one or more of the compounds listed in the following: alkylene glycols, ethylene oxide and/or propylene oxide derivatives; polyethylene glycols and/or polypropylene glycols; glycol ethers, ethylene oxide and/or propylene oxide derivatives; glycerol; polyglycerol; alcohols comprising 3 to 14 carbon atoms, and their isomers, other polyhydroxylated compounds such as pentaerythritol, trimethylolpropane, neopentyl glycol, and dimethylformamide, among other possible compounds.
• alkylene glycols ethylene oxide and/or propylene oxide derivatives
• the glycol ethers ethylene oxide and/or propylene oxide derivatives
• glycerin or alcohols comprising from 3 to 14 carbon atoms and isomers thereof.
• the surfactant present in the solubilizing medium may be comprised by one or more surfactants of the classes of anionic, cationic, non ionic, or amphoteric surfactants, or yet by polymeric surfactants.
• the anionic surfactants for use in the present inventions may comprise: Dodecylbenzene sulfonic acid, in linear form or with branching in the hydrocarbon chain, either in acid form or in the form of its alkaline metal salts (sodium, potassium, etc.), alkali earth metals (calcium, magnesium, etc.), nitrogenated compounds (ammonium, monoethanolamine, diethanolamine, triethanolamine, etc.), among others; alkyl ether sulfate salts of alkaline metals (sodium, potassium, etc.), alkali earth metals (calcium, magnesium, etc.), nitrogenated compounds (ammonium, monoethanolamine, diethanolamine, triethanolamine, etc.), among others; sulfoccinates in the form of salts, carboxylated surfactants, for example soaps, also in the form of salts, phosphated surfactants, also in the form of salts; among others.
• alkyl ether sulfates or some salts of the dodecylbenzene sulfonic acid derivatives it may be necessary to decrease the viscosity of the resulting concentrate, by means of addition of soluble ionic salts thereto, such as alkaline metal halides (NaCl, KCl, etc.). or yet, alkaline metal sulfates or permanganates.
• soluble ionic salts such as alkaline metal halides (NaCl, KCl, etc.). or yet, alkaline metal sulfates or permanganates.
• the dodecylbenzene sulfonic acid in its linear form or with branching in the hydrocarbon chain, in acid form or in the form of its salts of sodium, ammonium, monoethanolamine, diethanolamine, triethanolamme, calcium, among others.
• the non-ionic surfactants described in the present invention may be: alkoxylated, such as alkoxylated sorbitan esters, alkoxylated alcohols, alkoxylated vegetable oils, alkoxylated fatty acids, among others; fatty esters, such as polyethylene glycol esters, glycerol and/or polyglycerol esters, sorbitan esters; amides, such as fatty amides of ethanolamines or ethylene amines, fatty imidazolines, among others.
• alkoxylated such as alkoxylated sorbitan esters, alkoxylated alcohols, alkoxylated vegetable oils, alkoxylated fatty acids, among others
• fatty esters such as polyethylene glycol esters, glycerol and/or polyglycerol esters, sorbitan esters
• amides such as fatty amides of ethanolamines or ethylene amines, fatty imidazolines, among others.
• alkoxylated alcohols such as 2-ethylhexanoic acid, capric, caprylic, isodecyl, isotridecyl, undecyl, lauryl, cetyl, stearyl, isostearyl, hydroxystearyl, oleyl, alkoxylated to an alkoxylation level of between 1 and 12 moles of ethylene and/or propylene oxides
• alkoxylated vegetable oils such as alkoxylated castor oil with degrees of alkoxylation of between 1 and 60 moles of ethylene oxide and/or propylene oxide
• alkoxylated sorbitan esters with degrees of alkoxylation of between 5 and 80 moles of ethylene oxide and/or propylene oxide.
• the cationic surfactants of the present invention comprise, in a non- limitative list, the following substances: alkyl trimethyl ammonium chloride, dialkyl dimethyl ammonium chloride, alkyl hydroxyethyl dimethyl ammonium chloride, cetyl trimethyl ammonium chloride, esterquats, diestearyl dimethyl ammonium chloride, among others.
• the pesticides of the composition according to the present invention are chemical, synthetic or natural extraction products that evidence fungicidal activity, herbicidal activity, activity as insecticides, nematicides and/or acaricides, or mixtures thereof, and are used in the control and/or prevention of weeds, diseases, pests and other vectors that compete with agricultural production.
• the said pesticide is a fungicide, particularly a compound of the group of triazoles, more particularly tebuconazole, propiconazole, epoxyconazole, tetraconazole, metconazole, ciproconazole, amitrole, azaconazole, bitertanole, bromoconazole, difenoconazole, diniconazole, fenbuconazole, fluquinconazole, flusilazole, flutriafol, hexaconazole, imibenconazole, ipconazole, paclobutrazole, penconazole, prothioconazole, simeconazole, triadimefon, triadimenol, triazamatoe and/or triticonazole.
• a fungicide particularly a compound of the group of triazoles, more particularly tebuconazole, propiconazole, epoxyconazole, tetraconazo
• fungicides useful in the present invention are the benzoimidazoles, such as benomyl, carbendazim, Albendazole, thiabendazole, thiophanate-methyl and the strobirulines such as azoxystrobin, kresoxim-methyl, picoxystrobin, pyraclostrobin.
• the active ingredient may be formulated in concentrations of up to 40% w/w in the concentrated product.
• the nanodispersions of the active substances comprised in the formulation are applicable in agricultural defensives, and in other applications such as for treatment of wood, treatment of seeds, pharmaceutical applications, paints, treatment of leathers and fabrics, among other possible applications.
• the solubilizing medium of the present invention may comprise water in an amount of up to 20% of the concentrate.
• the formation of the concentrate occurs spontaneously by the solubilization of the biocide under gentle stirring, which may be provided by simple mechanical stirring means, by recirculation systems, or by any other means used in industrial practice, and it is possible, although unnecessary, to use means of high-energy or shearing such as grinding mills, dispersing devices, sonification systems, etc.
• antifoaming additives for the preparation of the concentrate, there may be optionally used antifoaming additives, should there occur any excessive formation of foam.
• the function of the surfactants consists in: solubilizing the biocide in the concentrate, reducing the particle crystallization kinetics and avoiding the formation of crystals during the shelf storage time of the product; stabilizing the nanodispersion of the active ingredient upon dilution in water, further avoiding the crystallization and the remaining mechanisms of loss of stability such as formation of aggregates, flocculation, etc.
• the stabilization of the dispersion is essential for the homogeneity of the liquor during the application thereof and to avoid clogging the injection nozzles on spraying type application.
• Formulations A, B, C, D and E were prepared by adding the active ingredient to the dispersant mixture under gentle stirring and heating between 50° C and 100° C, with subsequent stirring for 20 minutes and cooling to ambient temperature. From the concentrates, the nanodispersions were prepared by means of the dilution thereof in water with hardnesses of 20 to 342 ppm of alkali earth metals, in concentrations of between 0.25 and 1.25% weight/volume.
• examples A and C evidence the obtainment of nanodispersions with monomodal distribution, thereby evidencing the effectiveness of the invention to promote the reduction of the particle size of all active ingredient. This fact contributes to improve the stability of the nanodispersion.
• examples B and D show the majority of the sample (-85%) in a peak with particle size of the order of 180 nm, and a small amount of the sample with a larger particle size, of micrometric scale. This fact, however, did not influence the stability of the nanodispersion within a period of 13 days.
• Peaks 11, 12, 13, 14 are characteristic of a crystalline solid, in the present case, the tebuconazole.
• Curve 15 shows the existence of a great amorphous halo, indicating that the active ingredient is solubilized, without any presence of crystalline particles dispersed in the liquid.

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• Life Sciences & Earth Sciences (AREA)
• General Health & Medical Sciences (AREA)
• Health & Medical Sciences (AREA)
• Toxicology (AREA)
• Pest Control & Pesticides (AREA)
• Plant Pathology (AREA)
• Agronomy & Crop Science (AREA)
• Engineering & Computer Science (AREA)
• Dentistry (AREA)
• Wood Science & Technology (AREA)
• Zoology (AREA)
• Environmental Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Dispersion Chemistry (AREA)
• Agricultural Chemicals And Associated Chemicals (AREA)

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Cited By (7)

Citations (5)

• 2008
  • 2008-11-06 BR BRPI0804820 patent/BRPI0804820A2/pt not_active Application Discontinuation
• 2009
  • 2009-10-21 WO PCT/BR2009/000345 patent/WO2010051607A1/en active Application Filing

Patent Citations (5)

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