Abstract:
An effective emulsifiable concentrate for a low dosage fluorinated agricultural chemical, e.g. diflufenican, a herbicide, in optional admixture with a diluent active agricultural chemical, e.g. bromoxynil octanoate or isooctylmetachlorophenyl acetate herbicides is described herein.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to liquid delivery systems for active agricultural chemicals, and, more particularly, to an emulsifiable concentrate for delivering an admixture of a low dosage fluorinated agricultural chemical and a diluent active agricultural chemical to a plant site. 
     2. Description of the Prior Art 
     Emulsion concentrates are favored liquid delivery systems for active agricultural chemicals. See Narayanan U.S. Pat. Nos. 5,231,070; 5,298,529; 5,317,042; and 5,389,297. 
     An emulsifiable concentrate (EC) is a solution of the agchemical, solvents and surfactants that when diluted with water forms an emulsion which can be sprayed onto crops. An EC is needed for most agchemicals because they are usually water insoluble. Such concentrates are easy to store and transport, and various adjuvants may be added to increase the efficacy of the formulation. A good EC, however, requires that a stable emulsion be formed upon dilution with water, which emulsion does not separate upon standing. Furthermore, there should not be any crystallization of the active from the EC after water dilution. In addition, the EC itself must be stable with little degradation of the active over a long shelf life, and over a range of storage temperatures. 
     A poor EC is generally recognized by poor emulsion stability wherein the micelles of the emulsion are observed to coalesce upon water dilution, and by rapid crystal formation therein. For such ECs, it is necessary to add a crystal inhibitor, or, more likely, to reformulate the EC. A suitably reformulated EC thus must solubilize the active in a suitable solvent system which must also be sufficiently hydrophobic so that the active remains in the micelle and does not migrate into the water phase of the emulsion. 
     Accordingly, it is an object of this invention to provide an effective EC for an admixture of a low dosage, water-insoluble fluorinated active agricultural chemical and a diluent agricultural chemical. 
     These and other objects and features of the invention will be made apparent from the following more particular description of the invention. 
     SUMMARY OF THE INVENTION 
     What is provided herein is an EC for an admixture of a low dosage, water-insoluble fluorinated active agricultural chemical, such as diflufenican herbicide, and, optionally, a diluent active agricultural chemical such as bromoxynil octanoate or isooctyl-metachlorophenyl acetate herbicides which includes by weight, (a) about 20-60% of such an admixture of low dosage active and diluent active; (b) about 2-15% of an anionic surfactant, such as an ethoxylated nonyl phenol phosphate ester; optionally including 0-10% of a non-ionic surfactant, such as ethoxylated castor oil; and (c) about 15-30% of a C 6  -C 18  alkyl pyrrolidone; optionally including 0-10% of a C 1  -C 4  alkyl pyrrolidone or gamma-butyrolactone, and 0-30% of a C 6  -C 8  alkyl acetate. 
     DETAILED DESCRIPTION OF THE INVENTION 
     In accordance with the invention, the primary active agricultural chemical which has been formulated into a useful EC, is an admixture of a low dosage, water-insoluble fluorinated agricultural chemical, such as diflufenican, and, optionally, a diluent active agricultural chemical, such as bromoxynil octanoate. A typical admixture in the EC formulation includes about 2.6% diflufenican and about 37.1% bromoxynil octanoate. Other active agricultural chemicals as secondary diluents also may be included within this mixture if desired. 
     The EC composition thus includes (a) about 20-60% of the admixture of active agricultural chemicals; (b) about 2-15% of an anionic surfactant, suitably an ethoxylated nonyl phenol phosphate ester; optionally with up to about 10% of a non-ionic surfactant, suitably an ethoxylated castor oil; (c) about 15-30% of a C 6  -C 18  alkyl pyrrolidone, most suitably N-octyl pyrrolidone, N-isooctyl pyrrolidone or N-dodecyl pyrrolidone, or mixtures thereof, N-octyl pyrrolidone being preferred, optionally including up to 10% of a C 1  -C 4  alkyl pyrrolidone or gamma-butyrolactone, and optionally up to 30% of a C 6  -C 8  alkyl acetate. 
    
    
     EXAMPLES OF FLUORINATED ACTIVE INGREDIENTS AND DILUENTS 
     (A) Fluorinated active ingredients 
     Fluorinated Herbicides/Insecticides 
     Herbicides 
     FLURTAMONE (Chevron) 
     FLUMETSULAM (Dow Elanco) 
     CLODINAFOP-PROPARGYL (Ciba Geigy) 
     THIAZOPYR (Monsanto/Rhom AND Haas) 
     FLURPRIMIDOL (Dow Elanco) 
     ETHOXYFEN-ETHYL (Budapest Chemical) 
     FLUTHIACET-METHYL (Kumiai Chemical/Ihara Chemical) 
     SULFENTRAZONE (FMC) 
     FLUPOXAM (Kureha Chemical/Monsanto) 
     FLUMIOXAZIN (Sumitomo) 
     ISOXAFLUTOLE (FMC) 
     CARFENTRAZONE-ETHYL (FMC) 
     Herbicides (Diluents): 
     METOLACHLOR (Ciba Geigy) 
     TRIFLURALIN (Dow Elanco) 
     CHLOPYRALID (Dow Elanco) 
     2,4, D (Several Companies) 
     CLODINAFOP-PROPARGYL (Ciba Geigy) 
     ISOPROTURON (Rhone Poulenc) 
     DIURON (Rhone Poulenc) 
     DSMA (Disodium Methane Arsonate), and MSMA (Monosodium Methane Arsonate) 
     Insecticides 
     FIPRONIL (Rhone Poulenc) 
     FLUFENOXURON (Ciba Geigy) 
     FLUVALINATE (Sandoz) 
     FLUCYTHRINATE (Du Pont) 
     CYFLUTRRIN (Bayer) 
     TEFLUTHRIN (ICI) 
     BIFENTHRIN (FMC) 
     DIFLUBENZURON (Duphar, Netharlands) 
     TRIFLUMURON (Bayer) 
     CHLORFLURAZUM (Ciba Geigy/Ishihara) 
     Insecticides (Diluents) 
     CARBARYL (Rhone Poulenc) 
     PERMETHRIN (Several) 
     PIPERONYL BUTOXIDE (Several) 
     HYDRAMETHYLNON (Am. Cy) 
     DIAZINON (Ciba Geigy) 
     ALDECARB (Union Carbide) 
     Fungicides 
     FLUOROMIDE (Mitsubhishi) 
     FLUTRIAFOL (ICI) 
     FLUTOLANIL (Nihaku Nohyaku, Japan) 
     FLUSILAZOL (Du Pont) 
     TRIFLUMIZOLE (Nippon Soda Co) 
     Fungicide (Diluents) 
     PROPICONAZOLE (Ciba Geigy) 
     PENCONAZOLE (Ciba Geigy) 
     TRIFORINE (CelamercK, Germany) 
     THIABENDAZOLE (Merck) 
     DACONIL (ISK Biotech) 
     MANCOZEB (Rhom and Haas) 
     Plant Growth Regulators/Repellents/Rodenticides 
     FLUMETRALIN (Ciba Geigy) 
     FLURPRIMIDOL (Dow Elanco) 
     EFLUIDIDE (3M) 
     FLURAZOLE (Monsanto) 
     BROMETHALIN (Eli Lilly) 
     Plant Growth Regulators/Repellents/Rodenticides--Diluents 
     THIRAM (TETRAMETHYL THIURAM DISULFIDE)--(Du Pont) 
     ETHEPHON (Rhone Poulenc) 
     The EC compositions thus-prepared are shown in Table 1 below. The degree of stability of such EC compositions upon dilution with water (1:50) is given in Table 2 below. 
     
                       TABLE 1______________________________________EC COMPOSITIONS OF INVENTION           (1)  (2)    (3)    (4)  (5)______________________________________(a) Diflufenican      2.6    2.6  2.6  2.8  2.6    Bromoxynil octanoate                 37.1   37.1 37.1 --   37.1    MCPA Iso-octylester                 --     --   --   42.0 --(b) Nonyl phenol ethoxylated    phosphate ester    (Rhodofac ® RE610)                 5.0    5.0  5.0  --   5.0    (Rhodofac RM 710) --     --   --   6.0  --    Ethoxylated castor oil    (Alkamuls ® EL 719)                 5.0    5.0  5.0  6.0  5.0(c) N-Octyl pyrrolidone    (Agsol ® EX 8)                 22.6   22.6 25.2 25.9 25.2    N-Methyl pyrrolidone    (Agsol ® EX 1)                 --     5.1  --   4.3  --    Aromatic petroleum distillate    (Aromatic 200) (Exxon)                 5.1    --   --   --   20.1    Heptyl acetate    (Exxate 700) (Exxon)                 22.6   22.6 25.1 13.0 --    gamma-butyrolactone (BLO)                 --     --   --   --   5.0______________________________________ 
    
     
                                           TABLE 2__________________________________________________________________________Stability of EC CompositionsUpon Dilution with Water ((1:50)          Appearance    (1)   (2)   (3)   (4)  (5)__________________________________________________________________________Initial bloom    Excellent          Excellent                Excellent                      Excellent                           ExcellentAfter 20 inversions    Excellent          Excellent                Excellent                      Excellent                           ExcellentAfter 24 hrs    Excellent          Excellent                Excellent                      Excellent                           Excellent    (sl. trace          (sl. trace                (sl. trace (sl trace    ppt)  ppt)  ppt)       ppt)After 4 days    Excellent          Excellent                Excellent                      Excellent                           Excellent    (Trace ppt)          (Trace ppt)                (Trace ppt)                           (sl trace                           ppt)__________________________________________________________________________