PRECIPITATED FLOWABLE CONCENTRATE FORMULATIONS, THEIR PREPARATION AND THEIR AGRICULTURAL USES

Abstract: Disclosed are economical, stable pesticidal concentrate formulations, especially herbicidal, insecticidal and fungicidal formulations and their agricultural uses in water diluted form. Said concentrates contain a solid water-insoluble active material and a dispersant which are solubilized in a water miscible solvent and which upon dilution with water produces a narrowly distributed fine particle suspension suitable for use in agricultural spraying operations. These concentrate formulations being true solutions exhibit excellent stability during storage and the particle suspension formed upon dilution with water is readily suspendable and resistant to crystal growth.

Description: PRECIPITATED FLOWABLE CONCENTRATE FORMULATIONS, THEIR PREPARATION AND THEIR AGRICULTURAL USES The present invention is directed to economical, stable pesticidal agricultural concentrate - formulations, especially herbicidal, insecticidal and fungicidal concentrate formulations, their preparation and their agricultural uses in water diluted form. These concentrate formulations contain a solid water- insoluble active material and a dispersant solubilized 10 in a water miscible solvent which upon dilution with water, produces a narrowly distributed fine particle suspension suitable for use in agricultural spraying operations. These concentrate formulations being true solutions exhibit excellent storage stability and the 15 particle suspension formed on dilution with water is readily suspendable and resistant to crystal growth. These procedures generally practiced when a liquid based product concentrate is desired for an 20 active material which is insoluble in both water and , water immiscible solvents, is to prepare said material as a conventional suspension concentrate. These ζ concentrates are formulation systems wherein a finely 2c divided solid material is suspended in a liquid dispersing medium utilizing wetting agents, dispersants and rheological or suspending aids. In such formulations, the solid material usually constitutes from about 5 to 60 percent by weight and is present as distinct particles in the size range of 1 to 20 microns. Particle sizes of < 10 microns are preferred to enhance the suspensability of the active material in both the concentrate and upon dilution with water for field use. An even smaller particle size range, i.e., < 1 micron, depending on a specific active's mode of action, can also provide for improved biological efficacy. For example, when the diluted formulation is sprayed on a target surface, greater coverage and dissolution of the active material on the sprayed surface is achieved. In order to bring the solid material within the above indicated desired particle size ranges, it is generally necessary to mill or grind the active material either independently or in combination with the formulated system. This is usually carried out by expensive, time consuming and high energy use procedures such as, for example, air milling, sand milling, ball milling after initial hammer milling or other conventional wet or dry comminuting treatments known in the art. Problems associated with the concentrates thus prepared include: a. ) the non-homogeneous distribution of active material within the concentrate after extended storage from gravitational induced settling of these solid particles; b.) the potential that the active material which has settled during storage will resist resuspension into the dispersing medium; c.) the potential for the average particle to increase in size during storage due to thermal fluctuations and/or Ostwald ripening; d.) the active material cannot be readily reduced to the optimum particle size using mechanical methods. A desirable formulation for field use, involving active materials which are insoluble in both water and water immiscible solvents, would be one in which the active material is maintained homogeneously throughout the product concentrate prior to use. The user can then accurately prepare the end use system in the field and apply this to the target host in the appropriate dosage by controlling the amount of dilution in water. This product concentrate must readily disperse in water and the active material's particle size must be of such a size to ensure that a uniform spray solution can be maintained with minimal tank agitation, as well as, ensuring satisfactory, if not enhanced biological efficacy. It would also be desirable if this required particle size could be • obtained without resorting to the expensive comminuting treatments set forth hereinabove. The present invention is directed to three component stable pesticidal agricultural concentrates, which are defined as "precipitated flowables", and their preparation. In addition, the present invention is also directed to the agricultural uses of the spray system -H- formulations created by diluting the "precipitated flowable" concentrate with water. These concentrates of the present invention are comprised essentially of 1. ) a solid water insoluble active material and 2.) a dispersant which are solubilized in 3.) a water miscible solvent wherein said concentrate is in the form of a true solution and not susceptible to the general storage concerns of conventional suspension concentrates. The room temperature viscosity is between 10 and 1500 cps (centipose per second) at a shear rate of 100 sec-1 as measured by a conventional viscosity measuring device such as, for example, a Rotovisco RV 12 Viscometer (manufactured by Haake Buchler Inc.). The above solution concentrate on dilution with water, forms a system wherein the active material undergoes a controlled precipitation creating a non-settling dispersed aqueous suspension of solid particles which particles have a volume median diameter (VMD) of < 1 micron. The generation of this particle suspension is independent of water hardness, water temperature, concentrate viscosity, and "user" tank agitation and, as such, is very suitable for agricultural spray operations. This diluted phase of the "precipitated flowable" exhibits excellent static stability and is resistant to unwanted crystal growth for time periods that equal or exceed 4 hours. In preparing these concentrates of the present invention, one or more active pesticidal materials together with one or more appropriate dispersants, in a ratio of from about 1 percent by weight of the active to about 6 percent by weight of the dispersant up to a ratio of about 30 percent by weight of the active to about 1 percent by weight of the dispersant, are solubilized in a water-miscible solvent which comprises the remainder of the concentrate and which is usually present in from about 50 to about 95 percent by weight of the total concentrate. These ingredients can be added to the solvent in any order, with agitation. Normally, these preparation steps are carried out under ambient conditions, however, if it is desired to increase the rate of solubilization, the preparation can also be conducted at temperatures up to about 50°C. These active water-insoluble pesticidal materials useful in preparing these concentrates of the present invention have melting points greater than 50°C. and an inherent water solubility of less than 500 parts per million. Representative active water-insoluble pesticidal materials useful in preparing these above concentrate formulations are pesticidal materials which include but are not limited to those set forth below, for example: Atrazine: 2-chloro-4-ethylamino-6-isopropyl- amino-s-triazine; Assure: 2-(4-((6-chloro-2-quinoxalinyl)oxy)- phenoxy)propionic acid, ethyl ester; 2-(4-( (6-chloro-2-quinoxalinyl)oxy)phenoxy)-N- -propenylpropanamide; 2-(4-( (6-chloro-2-quinoxalinyl)oxy)phenoxy)-N- -(4-( 1 , 1 ,2,2-tetrafluoroethoxy)phenyl)propanamide; 2-(4- ( ( 6-chloro-2-quinoxalinyl )oxy) phenoxy) -N- -(4-( 2 , 2 , 2-trifluoroethoxy) phenyl )propanamide ; 4,4,4-t ichloro-2-( (3,5-dichlorophenyl)- -1,2-butanediol)-1-(4-methylphenylsulfonate) ; Cyanazine: 2-(4-chloro-6-ethylamino-1,3»5- -triazi - - l-amino)-2-methyl- propionitrile; Prometryne: 2,4-bis(isopropylamino)-6- -(methylthio)-l,3»5-triazine; Propanil: 3' > '-dichloropropionanilide; Naptalam: N-1-naphthylphthalamic acid; 10 Isoproturon: 3-(4-isopropylphenyl)-1 , 1-dimethylurea Chlorbromuron: 3-(4-bromo-3-chlorophenyl)-1- -methoxy-1-methylurea; Monuron: 3-( -chloropheny1)-1 , 1-dimethylurea; 15 Diuron: 3-(3 » 4-dichlorophenyl)-1 , 1-dimethylurea; Ethal luralin: N-ethyl-N-(2-methyl-2-propenyl)-2,6- -dinitro-4-(trifluoromethyl)- benzamine; Pendimethalin: N-(1-ethylpropyl)-3»4-dimethyl-2,6- -dinitrobenzenamine; 20 Oxadiazon: 5-£-butyl-3-(2,4-dichloro-5-isopropoxy- phenyl)-1 ,3»4-oxadiazol-2-one; Methazoie: 2-(3»4-dichlorophenyl)-4-methyl-1 ,2,4- -oxadiazolidine-3i5-dione; Chlorsulfuron: 1-(2-chlorophenylsulfonyl)-3-(4- 2 -methoxy-6-methyl-1,3»5-triazin- -2-yl)urea; Metsulfuron-methyl: methyl 2-((4-methoxy-6-methyl- -1 ,3-5-triazin-2-yl)- ureidosulfonyDbenzoate; ■ 3Q Imazaquin: 2-(4,5-dihydro-4-( 1-methylethyl)-5- -oxo-1H-imidazol-2-yl)-3-quinoline carboxylic acid; 2,4-DB: 4-(2,4-dichlorophenoxy)butyric acid; MCPB: 4-(4-chloro-o-tolyoxy)butyric acid; Dithianon: 5, 10-dihydro-5, 10-dixonaphtho-(2,3-b)- -1 ,4-dithi r.-2.3-dicarbonitrile; Tralkoxydim: 2-( 1-(ethoxyimino)propyl)-3-hydroxy-5' -(2,4,6-trimethylphenyl)cyclohex-2- -enone; 2-( 1-(ethoxyimino)propyl)-3-hydroxy-5-(4- -( (dichloro-2-pyridinyl)oxy)phenyl)cyclohex-2- -enone; N-(2,6-difluorophenyl)-5-methyl-1 ,2,4-triazolo- ( 1 ,5-a)pyrimidine-2-sulfonamide; 2-( ((7-chloro-5-methoxy-1 ,2,4-triazolo( 1 ,5-c)- pyrimidin-2-yl)sulfonyl)amino)-3-fluoro benzoic acid, methyl ester; 2-(4-((3-fluoro-5-(trifluoromethyl)-2- -pyridinyl)oxy)phenoxy)propionic acid; 4-amino-3,5-dichloro-6- luoro-2-pyridyloxy acetic acid; (+/-)ethyl 2,4-( (6-chloro-2-benzoxazolyloxy)- phenoxy)propanoate; 4-amino-3,5-dichloro-6-fluoro-2-pyridinyloxy acetic acid; Azinphos-ethyl: S-(3»4-dihydro-4-oxobenzo)(d)- -( 1,2,3)-((triazin-3-yl)methyl)- 0,0-diethylphosphorodithioate; Carbofuran: 2,3-dihydro-2,2-dimethylbenzofuran-7- -yl methylcarbamate; Heptachlor: 1 ,4,5,6,7,8,8-heptachlor-3a,7,7a- -tetrahydro- ,7-methanoindene; Tetramethrin: 3,4,5,6-tetrahydrophathalimido- methy1( 1RS) -cis,trc s-chrysanthemate; 1-(3,5-dichloro-4-( 1 , 1 ,2,2-tetrafluoroethoxy)- phenyl)-3-(2,6-difluorobenzoyl)urea; Diflubenzuron: 1-(4-chlorophenyl)-3-(2,6- difluorobenzoyDurea; 4-(4-( 1 , 1-dimethylethyl)phenyl)ethoxy)quinazoline; Amitraz: N-methylbis(2,4-xylyliminomethyl)amine; Benomyl: methyl 1-(butylcarbamoyl)benzimidazol- -2-ylcarbamate; Carbendazi : methyl benzimidazol-2-ylcarbamate; α-(4-chlorophenyl)-α-(2,2,2-trichloroethyl)-1H- -1 ,2,4-triazole-1-ethanol: Triadimefon: 1-(4-chlorophenoxy)-3,3-dimethyl-1- -(1H-1,2,4-triazole-1-yl)-2-butanone; Vinclozolin: 3-(3,5-dichlorophenyl)-5-methyl-5- -vinyloxazolidine-2,4-dione; Procymidone: N-(3,5-dichlorophenyl)-1,2-dimethyl- cyclopropane-1 ,2-dicarboximide Carboxin: 5,6-dihydro-2-methyl-1,4-oxathiin-3- -carboxanilide; Triforine: 1 ,4-bis(2,2,2-trichloro-1- -formamidoethyDpiperazine; Fenarimol: 2,4'-dichloro-α-(pyrimidin-5-yl)- benzhydryl alcohol; Nuarimol: 2-chloro-4'- luoro-α-(pyrimidin-5-yl)- benzhydryl alcohol; Captan: 1,2,3,6-tetrahydro-N-((trichloromethyl)- thio)phthalimide Folpet: N-((trichloromethyl)thio)phthalimide Tolyfluanid: N-((dichlorofluoromethyl)thio)N' ,N'- -dimethyl-N-p-tolysulphamide; Dichlofluanid: N-((dichlorofluoromethyl)thio)N' ,N'- -dimethyl-N-phenylsulphamide; and Chlorothalonil: tetrachloroisophthalonitrile. Representative dispersants useful in preparing these concentrates of the present invention include, for example: Ganex P-904: alkylated vinylpyrrolidone polymer; average molecular weight=l6,000; a product of GAF Corp.; Pluronic P-105: condensate of ethylene oxide with hydrophobia base formed by condensing propylene oxide with propylene glycol; a product of BASF Wyandotte Ind. Chem. Group.; T-Det N-6: nonylphenol-6 mole ethylene oxide adduct; a product of Thompson-Hayward Chemical Co. ; T-Det N-14: nonylphenol-14 mole ethylene oxide adduct; a product of Thompson-Hayward Chemical Co. ; T-Det N-30: nonylphenol-30 mole ethylene oxide adduct; a product of Thompson-Hayward Chemical Co. ; T-Det N-50: nonylphenol-50 mole ethylene oxide adduct; a product of Thompson-Hayward Chemical Co. ; Polyfon H: sodium salt of polymethacrylic acid; a product of W.R. Grace & Co.; Daravan No, 1 : sodium naphthalene sulfonic acid formaldehyde; a product of R.T. Vanderbilt Co.; PVP -15: polyvinylpyrrolidone polymer; average molecular weight=10,000; a product of GAF Corp.; PVP/VA E-735: vinylpyrrolidone/vinyl acetate co- polymer (50 percent ethanol solution); a product of GAF Corp.; Gafquat 734: vinylpyrrolidone/quaternized dimethylaminoethylmethacrylate co- polymer (50 percent ethanol solution); a product of GAF Corp.; Gantrez AN-119: poly(methyl vinyl ether/maleic anhydride) Low-mol.Wt. grade; a product of GAF Corp.; Genamin 0-200: fatty amine ethoxylate (oleyl; 20 moles ethylene oxide); a product of American Hoechst Corp.; Genamin S-200: fatty amine ethoxylate (stearyl; 20 moles ethylene oxide); a product of American Hoechst Corp.; Genapol 0-150: fatty alcohol ethoxylate (oleyl; 15 moles ethylene oxide); a product of American Hoechst Corp.; and Sapogenat T-130: tributylphenol ethoxylate (13 moles ethylene oxide); a product of American Hoechst Corp. These dispersants may be used alone or in combination depending on the specific final usage. Representative water miscible solvents useful in preparing these concentrates of the present invention include, for example: dimethyl ketone; α-butyrolactone; dimethylfuran; dimethylsulfoxide; methyl cyanide; methanol; and N-methyl pyrrolidone. These solvents may be used alone or in combination depending on the specific final usage. In making the concentrate of the present invention, one or more of these active compounds together with one or more of the dispersants in a ratio of from about 1 percent by weight of the active material to about 6 percent by weight of the dispersant to about 30 percent by weight of the active material to 1 percent by weight of the dispersant, are added to the solvent which makes up the remainder of the concentrate. While each of the dispersants and each of these solvents are very useful as indicated hereinabove, all combinations of the two are not always equally effective with all active materials. Prior to use, the concentrate is diluted with water to prepare these final aqueous formulations containing from about 0.00024 to about 0.24 percent by 10 weight of the active material. In their use a pesticidal or pesticidally effective amount of the active compound is used as the m m toxicant for contact with the pest or its habitat. The pesticidal amount, of course, is that quantity which elicits toxic mortality among these treated pests. Generally, such responses result by contacting these target pests or their habitat with said aqueous 0 formulation. In these agricultural uses set forth hereinbefore, the present invention also embraces the c employment of the present formulation in combination with one or more additional pesticidal compounds. Such additional pesticidal compounds may be other types of insecticides, nematocides, miticides, arthropodicides, herbicides, fungicides or bactericides that are 0 compatible with these compounds of the present invention in the aqueous medium used for application and which are not antagonistic to the activity of the present compounds. Accordingly, :n such embodiments, the additional pesticidal compound(s) is employed as a supplemental toxicant for i e same or for a different pesticidal use or as an additament. These compounds in combination can generally be present in a ratio of from about 1 to about 100 parts of the compound of the present invention with from about 100 to about 1 part of the additional compound. To determine whether or not a specific dispersant/solvent/active ingredient combination will be within these boundaries of the present invention, the concentrate is prepared and then diluted with water and the volume median diameter (VMD) of the particles in the dispersed particle suspension thus prepared is measured with a laser scattering particle sizer such as a Cilas 715 Granulometer (manufactured by Cilas Alcatel or an equivalent instrument) to determine if the volume median diameter is less than 1 micron. If the volume median diameter of the diluted system exceeds 1 micron either initially or within 4 hours after dilution, the diluted system is considered outside the specifications of the present invention. The following Examples illustrate the present invention and the manner by which it can be practiced, but as such, should not be construed as limitations upon the overall scope of the same. Example I A seven (7.0) gram (g) concentrate formulation was prepared by sequentially solubilizing 0.42 g (6 percent by weight) of 2-(4-(6-chloro-2-quinoxa- linyloxy)phenoxy)-N-(4-( 1 , 1 ,2,2-tetrafluoroethoxy)- phenyDpropionamide and 0.84 g (12 percent by weight) of Ganex P-904 in 5.74 g (82 percent by weight) of N- -methyl-2-pyrrolidone (NMP). 1:100 dilutions were prepared by mixing one (1) milliliter (mL) of the thus prepared concentrate with 100 mL of room temperature water of various hardness types. Twenty four hours thereafter, the particle size of these particles dispersed in the diluted formulation was measured with a Cilas 715 Granulometer and these results are set forth hereinbelow in Table I. TABLE I Example II A fifty (50.0) gram (g) concentrate formulation was prepared by sequentially solubilizing 3.00 g (6 percent by weight) of Atrazine and 0.15 g (0.3 percent by weight) of T-Det N-50 in 46.85 g (93-7 percent by weight) of NMP. 1:100 dilutions were prepared by mixing one (1) milliliter (mL) of the thus prepared concentrate with 100 mL of water of various temperatures. Twenty four hours thereafter, the particle size of the particles dispersed in the diluted formulation was measured with a Cilas 715 Granulometer and these results are set forth below in Table II. TABLE II Example III 1:100 dilutions were prepared by mixing one (1) milliliter (mL) of the concentrate prepared above in Example II with 100 mL of room temperature water both with and without agitation. Twenty four hours thereafter, the particle size of the particles dispersed in the diluted formulation was measured with a Cilas 715 Granulometer and these results are set forth below in Table III. TABLE III Example IV Five (5.0) gram (g) concentrate formulations were prepared by sequentially solubilizing a predetermined amount of Atrazine and a predetermined amount of Pluronic P-105 (P-105) in a predetermined amount of NMP. 1:100 dilutions were then prepared by mixing one (1) milliliter (mL) of one of the thus prepared concentrates with 100 mL of room temperature water. Thereafter, the particle size of the particles dispersed in the diluted formulation was measured with a Cilas 715 Granulometer and these results are set forth hereinbelow. TABLE IV Example V A thirty (30.0) gram (g) concentrate was prepared by sequentially solubilizing 1.8 g of one of 2- -(4-((6-chloro-2-quinoxalinyl)oxy)phenoxy)-N-(4-(2,2,2- -trifluoroethoxy)phenyl)propanamide or 2-(4-((6-chloro- -2-quinoxalinyl)oxy)phenoxy)-N-(4-( 1 , 1 ,2,2-tetrafluoro- ethoxy)phenyl)propanamide and 3.6 g of Ganex P-904 in 24 g of NMP. Serial dilution formulations were then prepared by mixing a predetermined amount of the thus prepared concentrate with separate 80 mL portions of room temperature water each containing 0.4mL of Silwet L-77 wetting agent. These thus diluted formulations all had a VMD of 1.0 or less as measured with a Cilas 715 Granulometer. Giant foxtail plants grown in beds of good agricultural soil and grown in a greenhouse to the 2-3 leaf stage were sprayed using an Allen greenhouse track sprayer (manufactured by Allen Machine Works) equipped with two (2) 8003 flat fan nozzles (manufactured by the Spraying Systems Co.) at a traversing speed and spray pressure so as to deliver a total spray volume of 20 gallon/acre, with one of these above prepared formula¬ tions at a predetermined treating rate. Other beds of these plants were sprayed with a Ganex P-904, NMP and Silwet L-77 mixture containing no active compound to serve as controls. After treatment, these beds were maintained for 13 days under greenhouse conditions conducive for good plant growth. At the end of this period, these beds were examined to determine the amount of kill and control of the foxtail plants. The dosage rate in the equivalent of pounds per acre and the percent kill and control (average of 2 runs) are set forth below in Table V. TABLE V

Claims: WHAT IS CLAIMED IS: 1. A stable three-component pesticide concentrate which comprises essentially a), from about 1 to about 30 percent by weight of a solid water-insoluble agricultural pesticidal compound; and b). from about 6 to about 1 percent by weight of a dispersant which are solubilized in c). a water-raiscible solvent wherein said concentrate is in the form of a true • solution. 2. The concentrate as defined in Claim 1 wherein the solid water-insoluble agricultural pesticidal compound is Atrazine. 3. The concentrate as defined in Claim 1 wherein the solid water-insoluble agricultural pesticidal compound is 2-(4-((6-chloro-2-quinoxalinyl)- oxy)phenox )-N-( -(2, ,2-trifluoroethoxy)pheny1)- propanamide. 4. The concentrate as defined in Claim 1 wherein the solid water-insoluble agricultural pesticidal compound is 2-(4-(6-chloro-2-quinoxalinyl)- oxy)phenoxy-N-(4-( 1,1,2,2-tetrafluoroethoxy)phenyl)- propionamide. 5. A method of preparing a stable three- component pesticidal agricultural concentrate formulation which consists essentially of solubilizing a), from about 1 to about 30 percent by weight of a solid water-insoluble active material pesticidal compound together with from about 6 to about 1 percent by weight of a dispersant b). in a water-miscible solvent wherein said concentrate is in the form of a true solution. 6. The method as defined in Claim 5 wherein the solid water-insoluble agricultural pesticidal compound is Atrazine. 7. The method as defined in Claim 5 wherein the solid water-insoluble agricultural pesticidal compound is 2-(4-((6-chloro-2-quinoxalinyl)oxy)phenoxy)- -N-( -(2,2,2-trifluoroethoxy)phenyl)propanamide. 8. The method as defined in Claim 5 wherein the solid water-insoluble agricultural pesticidal compound is 2-(4-(6-chloro-2-quinoxalinyl)oxy)phenoxy- -N-(4-(1 , 1 ,2,2-tetrafluoroethoxy)phenyl)propionamide. 9. A method for the kill and control of agricultural pest which comprises applying to said pest or their habitat a pesticidal amount of an aqueous formulation prepared by mixing water with a three- component stable pesticidal agricultural concentrate which concentrate consists essentially of a), a solid water-insoluble active material and b). a dispersant which are solubilized in c). a water-miscible solvent wherein said concentrate is in the form of a true solution. 10. The method as defined in Claim 9 wherein the solid water-insoluble agricultural pesticidal compound is Atrazine. 11. The method as defined in Claim 9 wherein the solid water-insoluble agricultural pesticidal compound is 2-(4-((6-chloro-2-quinoxalinyl)oxy)phenoxy)- -N-( -(2,2,2-trifluoroethoxy)phenyl)propanamide. 12. The method as defined in Claim 9 wherein the solid water-insoluble agricultural pesticidal compound is 2-(4-(6-chloro-2-quinoxalinyl)oxy)phenoxy- -N-(4-(1, 1,2,2-tetrafluoroethoxy)phenyl)propionamide.

Inventors: FLAIM TONY D, JENSEN JEFFREY L, KURIHARA NORMAN H, FLAIM, TONY, D., JENSEN, JEFFREY, L., KURIHARA, NORMAN, H.
Applicants: DOWELANCO
Application year: 1991
Main classification: A01N43
IPC codes: A01N25, A01N43