MXPA06006203A - Corrosion inhibitors for aqueous pesticide formulations - Google Patents

Abstract

The present invention relates to aqueous-containing pesticide concentrates containing an ionic nitrate salt additive as a corrosion inhibitor as well as pesticide compositions prepared from these concentrates and to the use of said compositions for controlling pests.

Description

CORROSION INHIBITORS FOR WATER-BASED PESTICIDE FORMULATIONS Field of the Invention The present invention relates to pesticide concentrates comprising at least one pesticide and an ionic nitrate salt. The present invention also relates to pesticidal compositions prepared from these concentrates and to the use of these compositions to control pests.

Background of the Invention Water-based pesticidal formulations are increasingly popular because of their improved profile for mammalian toxicity and ecological effects, as well as lower costs compared to formulations using an organic solvent as a diluent. Unfortunately, the introduction of even a small amount of water into a pesticidal composition increases the corrosion potential of the metal surfaces of the equipment used in the manufacture, storage, transport or packaging of the product. These corrosive characteristics can result in higher costs of equipment maintenance or equipment failure. The use of additives to reduce corrosion in pesticidal compositions is known in the art. However, the Ref .: 173238 additives and applications described are of a very specific nature. For example, US 2,788,307 describes the use of Na2S203 to reduce tinplate corrosion in contact with solvent-based DDT or lindane formulations. 2,630,380 discloses aryloxy and polyethylene glycol compounds in corrosion inhibitors in formulations based on 2,4-dinitro-6-alkylphenols. The use of bis (m-methylphenyl) phosphate to prevent iron corrosion in the presence of S-methyl-N- [(methylcarbamoyl) oxy] thioacetimidate is described in JP 56034562. JP 2000034201 discloses compositions that describe silica for avoid corrosion of containers by aqueous aerosols of pyrethroid insecticides. US 5,061,698 describes compositions based on boric acid with utility as corrosion inhibitors. US 5,032,318 discloses N-acyl sarcosine C? 3-C14 alkylamine salts as aerosol corrosion inhibitors in tin cans produced from tinplate. US 5,118,444 describes the use of a specific class of amine oxide to reduce corrosion in aqueous compositions of pesticides. The corrosion potential in water-based formulations increases when the formulation has an acidic pH. There is a variety of important pesticide active ingredients that contain an acid entity in their structure and a water-based formulation of these products can have an acidic pH. There may be other reasons for keeping the pH of the pesticidal formulation at an acidic level, such as improved chemical stability for the active ingredient or improved physical stability for the product during storage. The presence of dissolved salts such as ionic chlorides or pesticide active ingredients present in a metal or salt complex can also accelerate the corrosion of metal surfaces. Surprisingly, it has been found that certain nitrate salt additives significantly reduce the corrosion properties of water-based pesticidal formulations, even at acidic pH levels and in the presence of a salt. The additives of the present invention can be incorporated into the pesticidal aqueous composition during the initial process of the formulation or can be added at any subsequent storage, transport or packaging step to reduce corrosion. The additives of the present invention also have the advantage of being easily found at a relatively low price. The use of nitrate salts, especially ammonium nitrate as nitrogen fertilizer, is well established in the agricultural industry and the use of ammonium nitrate and other nitrogen fertilizer solutions with the same carrier for tank mixing for the application of herbicides. they are preferably included in the instructions of the product label. However, the use of nitrate salts in nitrogen-bearing fertilizer liquids involves large quantities per acre. There are also reports in the patent literature (US 5,658,855, US 2003104947, US 2003125211 and WO 02/19823) for the use of compositions containing ammonium nitrate as additives for aerosol application for greater herbicidal activity. However, pesticidal compositions incorporating these additives are highly diluted aerosol mixtures that are normally prepared just before use by mixing the components directly in the spraying equipment.

Brief Description of the Invention Certain corrosion inhibiting additives are provided for pesticide formulations containing water that are effective under potentially severe corrosion conditions. The compositions of the present invention have utility in particular when the pH of the composition is less than or equal to 6 and / or where a salt or metal complex is present, either as the pesticidal active ingredient or as an adjunct to the formulation. In one embodiment, the invention relates to a pesticidal concentrate comprising: a) water b) at least one pesticide c) an amount of an ionic nitrate salt additive effective to reduce corrosion of metal surfaces d) optionally, other auxiliaries of the formulation where the proportion of component c) with respect to component b) is less than or equal to 0.3: 1. The invention also relates to pesticidal compositions prepared from these concentrates and to the use of the compositions for controlling pests.

Detailed Description of the Invention It has surprisingly been discovered that pesticide concentrates with reduced corrosion properties can be obtained by incorporating an ionic nitrate salt into the concentrate. The invention relates to a pesticidal concentrate comprising: a) 2-85% by weight of water b) 5-90% by weight of at least one pesticide c) an ionic nitrate salt additive in an amount effective to reduce the corrosion of metallic surfaces d) optionally, other auxiliaries of the formulation where the proportion of component c) with respect to component b) is less than or equal to 0.3: 1.

The invention also relates to pesticidal compositions prepared from these concentrates, with the use of ionic nitrate salt additives to reduce corrosion of metal surfaces and with the use of these compositions to control pests comprising the step of applying in the place that needs protection, an effective amount of the pesticidal composition of the invention. The compositions of the present invention have a particular utility when the pH of the composition is less than or equal to 6 and / or where a salt or metal complex is present, either as the pesticidal active ingredient or as an adjunct to the formulation. Suitable nitrate salts for use as additives of the corrosion inhibitor in the present invention include ammonium nitrate, alkali metal nitrates and alkaline earth metal nitrates, for example, sodium nitrate and calcium nitrate. These salts are easily found in commerce. The additives of the present invention can be incorporated into the pesticidal composition during the initial formulation process or can be added at any subsequent storage, transport or packaging step to reduce corrosion. The concentrates of the present invention contain water in a range of 2% to 85% by weight, preferably 5% to 65% by weight. The pesticidal concentration ranges from 5% to 90% by weight, preferably 25% to 75% by weight, the nitrate salt additive being present in an amount effective to reduce corrosion of metal surfaces, usually at a concentration ranging from 0.001% to 10% by weight. The ratio of nitrate salt additive to pesticide concentration is less than or equal to 0.3: 1. A preferred embodiment of the invention is a composition comprising ammonium nitrate as the corrosion inhibiting additive. A further preferred embodiment of the invention is the use of an ionic nitrate salt additive in an aqueous pesticidal composition to inhibit corrosion. Pesticidal active ingredients suitable for the present invention include both water-soluble and water-insoluble compounds. Water-soluble active ingredients include pesticides or plant growth regulators such as acephate, acifluorfen, acrolein, amitrol, asulam, benazolin, bentazon, bialaphos, borax, bromacil, bromoxynil, butoxycarboxy, calcium polysulfide, cartap, chloramben, chlormequat, chloroacetic acid, chlorofonium, clofencet, clopyralide, cloxifonac, copper sulfate, cyanamide, 2, 4-D, 2, 4-DB, dalapon, daminozide, dicamba, diclorprop, diclofop, diclotofos, difenzocuat, dicengulac, dicuat, endotal, ethephon, fenac, fenoxaprop, flamprop, fluazifop, fluoroglycophene, flupropanate, fomesafen, formetanate, fosamine, fosetyl, glufosinate, glyphosate, guazatine, haloxifop, hydroxyquinoline sulfate, imazamet, imazametabenz, imazamox, imazapic, imazapir, imazaquin, imazetapyr, iminoctadine, ioxinil, kasugamycin, MCPA, MCPB, mecocrop, mepicuat, mercuric chloride, metam, methanidofos , met-methyl, methylarsonic acid, mevinfos, monocrotophos, nabam, naptalam, nicotine, nitenpyran, nonanoic acid, ometoate, oxamyl, oxidemeton-methyl, paraquat, phosphamidon, picloram, polyoxin B, propamocarb, sulfamic acid, 2,3,6-TBA, thiocyclam, trichlorfon, trichloroacetic acid, triclopyr, validamycin and vamidothion as well as their esters and agriculturally acceptable salts. Preferred water-soluble active ingredients include glyphosate, glufosinate, paraquat, dicuat, dicamba, fomesafen, 2,4-D, 2,4-DB and their agriculturally acceptable salts. The most preferred water-soluble active ingredients include glyphosate, glyphosate, paraquat and their esters and agriculturally acceptable salts. Preferred salts of glyphosate include isopropylammonium, potassium, ammonium and trimethylsulfonium. Hydroinsoluble active ingredients include pesticides, herbicidal antidotes or plant growth regulators such as abamectin, acetochlor, aclonifen, acrinatrin, amitraz, atrazine, azadirachtin, azamethiphos, azinphos-methyl, azocyclotin, azoxystrobin, BAS 670, benalaxyl, benomyl, benoxacor, bensulfuron- methyl, bensultap, benzophenap, 6-benzylaminopurine, bifenox, bifenthrin, bitertanol, bromobutide, bromophenoxy, bromopropylate, bromuconazole, buprofezin, butafenacil, captafol, captan, carbendazim, chinomethionate, chloroxuron, chlorbomuron, chlorfenapyr, chlorfenson, clorduazuron, chlorimuron-ethyl, clornitrofen, chlorothalonil, chlorotoluron, chlortal-dimethyl, clozolinate, clofenzene, clomeprop, coumaphos, cyclanilide, cyfluthrin, beta-cyfluthrin, cypermethrin, alpha-cyperpentrin, teta-cypermethrin, cymiminyl, cyprodinil, dai uron, DDT, deltamethrin, desmedipham, diafentiuron, diclobenil, diclofluanide, dichlormid, 4-dichloroacetyl-l-oxa4-aza-spiro [4, 5] decane, dicl orophen, diclomezine, dicloran, dicofol, diciclonon, dietofencarb, diflubenzuron, diflufenicam, dimefuiron, dimethenamid, dimetomorph, diniconazole, dinitramide, dithianon, diuron, endosulfan, epoxiconazole, esfenvalerate, etametsulfuron-methyl, etoxazole, famozadone, fenarimol, fenazaquine, fenbuconazole, fenbutatin oxide, fenchlorim, fenfuram, fenoxaprop-ethyl, fenoxicarb, fenpiclonil, feniproximate, fentino, fipronil, flamprop-methyl, flazasulfuron, flurazole, fluazinam, fluazuron, flucycloxuron, fludioxonil, flufenoxuron, flumetralin, flumetsulam, flumiclorac-pentyl, flumioxazine, fluoroimide, flupoxam, fluquinconazole, fluridone, flurtamone, flusulfamide, flutolanil, fluxofenim, folpet, forclorfenurom, flurilazole, glyphosate acid, halofenoxide, gamma-HCH, hexachlorobenzene, hexaconazole, hexaflumuron, hexitiazox, hydramethylnon, imibenconazole, inabenfide, ipconazole, iprodione, isoproturon , isoxabeno, isoxaflutol, isoxapirifop, kresoxim-methyl, lactofen, lenacilo, linuron, l ufenuron, mancozeb, manebo, mefenacet, mepanipyrim, mepronil, mesotrione, metal complexes of mesotrione, metalaxyl, metconazole, metabenzitiazuron, methiocarb, metolachlor, s-metolachlor, methoxychlor, metiram, etobenzuron, milbemectin, 2- (1-naphthyl) acetamide, naproanilide, neburon, nickel bis (dimethyldithiocarbamate), nicosulfuron, norflurazon, novaluron, nuarimol, orizaline, oxabetrinyl, oxadiazon, oxine copper, oxolinic acid, oxyfluorfen, paclobutrazol, pencicuron, pentachlorophenol, fenmedifan, N-phenylphthalamic acid, phthalic, primisulfuron, procymidone, prodiamine, prometryn, propazine, propiconazole, propineb, propyzamide, propsulfuron, pyrazolinate, pyrazosulfuron-ethyl, pyributicarb, pyridaben, quinclorac, quintozene, quizalofop-etil, resmetrina, rimsulfuron, rotenona, siduron, simazina, sulfotriona, sulfluramida, sulfur, tebuconazol, tebufenozida, tebufenpirad, tebupirimfos, tecloftálamo, tecnaceno, teflubenzuron, terbutilazina, terbutrina, tetrachlorvinfos, tetradifon, tetratrina, tiametoxa, thiazopir, tidiazuron , tifluzamide, thiodicarb, thiophanate-methyl, thiram, tolclofos-methyl, tolylfluamide, talcoxidime, tralometrine, triadimefon, triadimenol, triazoxide, trietazine, triflumuron, triforine, trimetacarb, triticonazole, uniconazole, vinclozoline, zineb and ziram as well as their esters and salts agriculturally acceptable. Preferred hydroinsoluble active ingredients include mesotrione and metal chelates of mesotrione, atrazine, simazine, terbutilazine, sulcotrione, metolachlor, s-metolachlor, acetochlor, dimethenamid, abamectin, thiamethoxane, azoxystrobin, metalaxyl, propiconazole, benoxacor, dichloride, 4-dichloroacetyl- l-oxa4-aza-spiro [4, 5] decane and furilazole. The most preferred hydroinsoluble active ingredients include mesotrione and metal chelates of mesotrione, atrazine, metolachlor, s-metolachlor and benoxacor. The most preferred mesotrione metal chelates include those where the transition metal is selected from the group comprising copper, cobalt, zinc and nickel. In a particularly preferred embodiment, the compositions comprise a mesotrione metal chelate, preferably a copper or zinc chelate of mesotrione. Formulation aids that may be present in the form of salts include alkaline earth metal and alkali metal chlorides such as sodium chloride and calcium chloride.

Auxiliaries of the formulation for the present invention further include, inter alia, surfactants, thixotropic agents, antifoaming agents, antifreeze agents and preservatives. Normally, the surfactants will be present in the concentrates of the invention. Suitable surfactant compounds are, depending on the nature of the active ingredient, nonionic, cationic and / or anionic surfactants and mixtures of surfactants with good emulsifying, dispersing and wetting properties. Examples of suitable anionic, nonionic and cationic surfactants are listed, for example, in U.S. Pat. Number 6,063,732, column 5 row 1 to column 6, row 2 whose contents are incorporated herein by reference. Moreover, the surfactants commonly used in formulation technology, which are described, among others, in "Me Cutcheon's Detergents and Emulsifiers Annual" MC Publishing Corp., NJ Ridgewood, 1981, Stache, H., "Tensid-Tascheribuch", Carl Hanser Verlag, Munich Nienna, 1981 and M. and J. Ash "Encyclopedia of Surfactants", Vol. I-III, Chemical Publishing Co., New York, 1980-81, are also suitable for the preparation of herbicidal compositions of the invention. The amount of surfactants depends on the particular active ingredients selected for the composition and the absolute and relative amounts that are desired of them. Suitable amounts of stabilizer system components selected from these classes or specific examples provided herein can be determined by routine experimentation, the test being that substantially no separation, sedimentation or flocculation phase is shown by the composition from storage to 20-25. ° C for a period of time of 24 hours or for the preferred embodiments, after a longer storage period during a wider range of temperatures as indicated above. Normally, the total concentration of all the surfactants give the composition as a whole, is from about 1% to 30% by weight, excluding the weight of the counterions if they are present. The invention also relates to pesticidal compositions obtained by i) diluting the pesticide concentrate of the present invention in a suitable carrier such as water, so that the final pesticide concentration is between about 0.01% to about 10% of the active ingredient (ai). ). The invention also relates to a method for the control of pests, the method comprising forming a pesticide composition by i) diluting the pesticide concentrate of the present invention in a suitable carrier such as water, so that the final concentration of pesticide is of about 0.01% to about 10% of the active ingredient (ai) and ii) treating the desired area as a culture, its seeds or shoots or the area of the culture with that composition. The invention also relates to the use of an ionic nitrate salt additive in an aqueous pesticide composition to inhibit corrosion. The composition according to the invention is suitable for all application methods conventionally used in agriculture, for example preemergent application, postemergent application and seed coating. The composition according to the invention is especially suitable for controlling pests in crops of useful plants such as cereals, rapeseed, beets, sugar cane, plantations, rice, corn and soybeans. In this definition, the term "crops" also includes those crops that have become tolerant to pests and pesticides, including herbicides or classes of herbicides as a result of conventional methods of genetic manipulation or breeding. The components used in the composition of the invention can be applied in a variety of ways known to those skilled in the art and at various concentrations. The speed at which pesticide compositions are applied will depend on the particular type of pest to be controlled, the required degree of control and the method and timing of application. The cultivation areas are areas of land on which the cultivated plants are growing or where the seeds of those cultivated plants have been sown and also areas of land where these cultivated plants are to be cultivated. Other active ingredients such as coherbicides, fungicides, insecticides, acaricides and nematocides may be present in the emulsifiable concentrate or may be added together with the tank mixture with the emulsifiable concentrate. Suitable thixotropic additives are compounds that impart a pseudoplastic flow behavior to the formulation, that is, a high viscosity at rest and a low viscosity in an agitated state. Examples of suitable compounds include polysaccharides such as xanthan gum, elzan® by Kelco or Rhodopol® 23 by Rhone Poulenc.

For example, suitable defoamers include silicone emulsions, long chain alcohols, fatty acids, organofluoride compounds and mixtures thereof. The following examples further illustrate some aspects of the invention but are not intended to limit its scope. Where not specified during this specification and claims, temperatures are given in degrees centigrade and the percentages are by weight.

EXAMPLE 1 Preparation of test material for the mesotrione and copper suspension concentrate. The test material is prepared according to the following composition: Mesotrione 35.0% Surfactant of Soprofor BSU (tristirylphenol of 16 moles ethoxylate) 3.5% Acetic acid (ice cream) 6.2% Copper hydroxide (100%) 5.1% 0.1% silicone antifoam agent 0.1% xanthan gum thixotropic agent Water 50.0% is born xa mix of water, acetyl iron and copper maroxiao. Add mesotrione and then the surfactant, antifoam and thixotropic agent and mix until uniform. Mash until the particle size of the suspended solid is less than 10 microns. The resulting mixture has a pH of about 3.0.

EXAMPLE 2 Testing candidates for corrosion inhibiting additives The following procedure was used to test a series of 17 candidate materials as corrosion inhibitors together with a control sample containing no inhibitor. Weigh in a 16-ounce sample bottle and mix thoroughly: 1) 325 grams of the concentrate of the copper mesotrione suspension of Example 1, 2) 15 grams of the mixture of xanthan gum, thixitropic agent / water (2%) concentration) and 3) 10 grams of the candidate corrosion inhibitor material.

Submerge two heavy corrosion coupons of 304 stainless steel (one welded and one without solder) in the liquid, close and seal the lid and place the bottle in an oven at 50 ° C. After four weeks of storage at 50 ° C, remove the coupon from the liquid, wash with a hard toothbrush in soap and water, rinse with acetone and dry. Weigh the coupon and visually inspect to determine the severity of the corrosion. The results of the corrosion inhibition test are presented in the following Table 1.

* Composition within the scope of the present invention. The control sample (# 1) which had no corrosion inhibitor present showed significant corrosion of the 304 stainless steel coupon as indicated by the weight loss of both the welded and unwelded coupons and the visual inspection showed that there was a lot of corrugation. Several of the candidate inhibitors did in fact result in increased corrosion while others showed a moderate inhibition of corrosion. Two samples (# 6, # 7) showed weight gain, probably due to the formation of copper plate in the coupons. The sample with ammonium nitrate (# 18) of the present invention, however, showed a dramatic increase in corrosion with respect to the control as evidenced by a very small weight loss for the coupons and visual inspection that "- showed no rust or other residues present Although only a few exemplary embodiments of this invention have been described in detail, those skilled in the art readily appreciate that various modifications to the exemplary embodiments may be made possible without departing materially from the teachings and advantages of this invention. , all these modifications are intended to be included within the scope of the invention as defined in the following claims.It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it refers.

Claims (13)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property: 1. A pesticide concentrate characterized in that it comprises: a) 2-85% by weight of water b) 5-90% by weight of at least one pesticide c) an amount of ionic nitrate salt additive effective to reduce corrosion of metal surfaces d) optionally, other auxiliaries of the formulation where the ratio of component c) to component b) is less than or equal to 0.3: 1 .
2. 2. The concentrate according to claim 1, characterized in that the pH of the concentration is 6 or less.
3. 3. The concentrate according to claim 1, characterized in that the pesticide is in the form of a metal salt or chelate.
4. 4. The concentrate according to claim 1, characterized in that it comprises at least one auxiliary of the formulation in the form of a salt.
5. 5. The concentrate according to claim 4, characterized in that the formulation aid in the form of a salt comprises at least one alkaline metal or alkali metal chloride.
6. 6. The concentrate according to claim 1, characterized in that the ionic nitrate salt comprises ammonium nitrate.
7. 7. The concentrate according to claim 1, characterized in that the pesticide comprises mesotrione or a metal chelate or agriculturally acceptable salt thereof.
8. 8. The concentrate according to claim 7, characterized in that the pesticide comprises a zinc or copper chelate of mesotrione. 9. A pesticidal composition characterized in that it is obtained by diluting a concentrate according to claim 1, with an adequate amount of a carrier. 10. A pesticidal composition according to claim 9, characterized in that the carrier is water. 11. A pesticidal composition according to claim 9, characterized in that it comprises at least one member selected from the group comprising herbicides, fungicides, insecticides, acaricides and nematocides. 12. A method for the selective control of pests in crops of useful plants, characterized in that it comprises a treatment of useful plants, their seeds or their shoots or the culture area thereof with a pesticidal composition according to claim
9. 9. 13 The use of an ionic nitrate salt to inhibit corrosion in an aqueous pesticide formulation.