WATER SOLUBLE POWDER GLYPHOSATE FORMULATION

Abstract: A novel water-soluble powder glyphosate formulation.

Description: Title: "WATER SOLUBLE POWDER GLYPHOSATE FORMULATION" This invention relates to a novel watersoluble powdered glyphosate formulation. Glyphosate (N-phosphonomethylglycine) is well- known in the art as an effective herbicide. It is known in the art that glyphosate, which is an organic acid, is rela¬ tively insoluble in water. Therefore, glyphosate is normally formulaed and applied as a water-soluble salt, especially as the isopropylamine salt. Various formulations of glyphosate are disclosed in U.S. Patents 4,405,531, 3977,860 and 3,853,530. Roundup^ Herbicide is the widely used commercial form of glyphosate and comprises the isopropylamine salt of glyphosate, surfactant(s) , other adjuvants and water. Roundup® Herbicide is sold as a water-soluble concentrate. It is desired in the art to find a water-soluble powder formulation of glyphosate which has the equivalent efficacy of Roundup^ Summary of the Invention The present invention relates to a herbicidal water¬ soluble dry-particulate glyphosate formulation comprising the sodium salt of glyphosate and a surface active agent having the following formula: wherein R, and R~ are independently methyl or ethyl; R 3 is methyl, ethyl, benzyl or C 1Q to C _ alkyl; R. is Cm r , to C- o alkyl and X is chloro or bromo. The water soluble powder formulation of the present invention has an efficacy substantially equivalent to Roundup® Herbicide ' . The powdered formulation will enable substantial savings in transportation and storage costs. A more thorough disclosure of the present invention is presented in the detail¬ ed description which follows. Detailed Description of The Invention The present invention relates to a herbicidal, water soluble dry-particulate glyphosate formulation compris¬ ing the sodium salt of glyphosate and a surface-active agent having the following formula: R 2 NR 3 (X) R„ wherein R, and R~ are independently methyl or ethyl; R 3 is methyl, ethyl, benzyl or C . to C g alkyl, R 4 is C- Q to C.g alkyl and C is chloro or bromo. The water-soluble dry-particulate glyphosate formu¬ lation of the present invention has herbicidal efficacy which is substantially equivalent to the commercial glyphosate • formulation Roundup. Further; the formulation of the present invention is comparably efficacious at smaller surfactant to glyphosate rations than sodium glyphosate formulations com¬ prising the same surfactant(s) as' used in Roundup Herbicide. This indicates that the surfactants of the present invention are more efficient in maintaining the sodium salt of glypho- • sate in contact with the surface of the. plant to facilitate penetration of the glyphosate into the plant than is the surf¬ actant(s) used in Roundupr Herbicide. Glyphosate is well-known to those skilled in the art. Several processes for the preparation of glyphosate are disclosed in the patent and chemical literature, e.g., U.S. Patents 3,977,860 and 4,486,358. The * powdered sodium salt of glyphosate (mono, di, sesqui) can be prepared by a variety of processes. First, the sodium salt of glyphosate can be prepared in accordance with the procedure set forth in U.S. Patent 4,140,513. Alternatively, glyphosate can be mixed with an alkali base such as sodium hydroxide and the solution spray- dried to form the powdered sodium salt of gylphosate. Alternatively, the mono-sodium salt can be prepared by adding a solid alkali metal base with agitation to an aqueous slurry of N-phosphonomethylglycine containing at least 50% solids. Surfactants useful in the formulation of the present invention are commercially available from a number of manufacturers. Suitable surfactants are •described in McCutcheon's Detergents and Emulsifiers, North American Edition 1980 Annual and in McCutcheon's Detergent and Emulsifiers International Edition 1982. Suitable surfactants which are useful in the formulation of the present invention are alkyl-trimethyl ammonium chloride, alkyl-benzyl-dimethyl ammonium chloride and dialkyl dimethyl ammonium chloride. The preferred alkyl-trimethyl ammonium chloride surfactant is cetyl- trimethyl ammonium chloride. Preferred cetyl-trimethyl. ammonium chlorides are Emulgin IB-25, Drewfax 277, Dehyquat A and Dodigin 226. It will be obvious to one skilled in the art that other surfactants within the scope of the present invention will also be useful. The formulations of the present invention are comprised of a dry, free-flowing particulate solid with varying particle sizes from powder to granules. Formulations of the present invention comprise the following ingredients: Ingredient Wt % sodium glyphosate 5 to 95 Surfactant 5 to 40 Preferred formulations are as follows: Ingredient Wt % sodium glyphosate 15 to 85 surfactant 5 to 20 The sodium sailt of glyphosate useful in the formulation of the present invention will suitably have a water content of less than 3% by weight. The formulations of the present invention may also be admixed with other additives such as urea, ammonium sulfate, silica, thickening agents, anti-foam agents such as silicones, water-repellants, humectants, chelating agents, dyes, dispersing agents, and other powdered active " ingredients such as herbicides and fungicides or the like. The formulations of the present invention can be readily diluted in water by the farmer in a spray tank prior to use. Suitable application rates of active ingredients will vary depending on plant species, but generally 90 to 360 grams per hectare on an acid equivalent basis will be suitable. The following examples are presented to illustrate the present invention as well as some of the various embodiments of the invention. These examples are presented as being illustrative of the novel formulations and are.not intended to be a limitation after the scope thereof. Example 1 Typical formulation Wt % 1. monosodium glyphosate 91.2 cetyl trimethyl ammonium chloride 8.8 2. monosodium glyphosεte 90.9 alkyl dimethyl benzyl ammonium 9.1 chloride Example 2 In this greenhouse test, two variety of difficult to kill plants prevalent in Brazil were treated with formulations of the present invention, Brachiaria (a narrow leaf plant) and Euphorbia (a broad leaf plant). The mono-sodium salt of glyphosate was tank-mixed in water with the indicated surfactant to provide indicated glyphosate concentration as set forth in the following tables. "A" designated trade secret surfactant(s) used in Roundup® Herbicide. "B" designates a surfactant chemically identical to "A" but produced by a different manufacture. Table. I • Test 1 Rate Percent Control Glyphosate ** Surfactant Brachiaria Euphorbia (q/ha) Surfactant Rate DAT) DAT)* 360 Drewfax 277 90 99 (20) 69 (20) II 180 99 74 II Emulgin IB-25 90 95 63 II II 180 97 67 II B 90 97 74 II II 180 100 80 II Roundup® 99 80 II Test 2 360 Emulgin IB-25 90 96 (21) 41 (21) II 180 97 66 II Dehyquat A 90 92 49 II II 180 100 67 II A 90 98 59 II II 180 96 62 II •B 90 98 64 II II 180 98 71 II Roundup® 100 73 II * Days after treatment ** Acid equivalent basis Table II Surfactant Percent Control Commercial Ratio BRACHIARIA EUPHORBIA Name Common Name Glyph*:Surf 10 DAT. 21 DAT 10 DAT 21 DAT Emulgin cetyl-trimethyl IB-25 ammonium chloride 1:0.06 83 92 53 69 II II 1:0.13 86 97 58 74 II II 1:0.19 96 99 60 72 Dodigen 226 alkyl-benzyl- 10 dimethyl ammonium chloride 1:0,13 69 91 61 74 II II 1:0.25 78 96 59 75 II II 1:0.38 93 98 77 79 • Dodigen dialkyl dimethyl 15 1881 ammonium chloride 1:0.13 79 91 52 68 II II 1:0.25 87 97 63 71 Roundup® 97 99 50 75 * Acid equivalent basis Table III Application glyphosate concentration 360 g ha (a.e.) Percent Control Rate Brachiaria Euphorbia Surfactant g ha 21 DAT 21 DAT Emulgin IB-25 45 91 32 II 90 93 47 II 180 95 53 A 45 85 47 ω 10 II 90 95 56 I II 180 98 68 Roundup® • 98 50 Although this invention has been described with respect to specific embodiments, the details " hereof are not to be construed as limitations, for it will be apparent that various equivalents, changes and- modifications may be resorted to without departing from the spirit and scope thereof and it is understood that such equivalent embodiments are intended to be included within the scope of this invention.

Claims: WE CLAIM: 1. A herbicidal water-soluble, particulate formulation comprising the sodium salt of N-phosphono- methylgycine and a surface-active agent having the following formula: wherein t and R 2 are independently methyl or ethyl; R 3 is methyl, ethyl benzyl or C 10 to C 18 alkyl; R 4 is Cio to Cis alkyl and X is chloro or bromo. 2. The formulation of Claim 1 wherein the salt of N-phosphonomethylglycine is the monosodium salt. 3. The formulation of Claim 1 wherein the- surface active agent is cetyl-trimethylammonium chloride. 4. The formulation of Claim 1 wherein the surface active agent is alkyl-benzyl-dimethylammonium chloride. 5. The formulation of Claim 1 wherein the surface active agent is dialkyl dimethylammonium chloride. -11- 6. A herbicidal, water soluble, particulate formulation comprising the monosodium salt ' of N-phosphonomethylglycine and a surface active agent having the following formula: wherein R x and R 2 are independently methyl, ethyl; R 3 is methyl, ethyl, or benzylor Cι 0 to C 18 alkyl; R 4 is Cio to C 18 alkyl and X is chloro or bromo. 7. A herbicidal, water soluble, particulate formulation comprising the monosodium salt of N-phos¬ phonomethylglycine and cetyl-trimethyl ammonium chloride,

Inventors: BERGSON FERNANDES BARRETO HENR, TEIXEIRA COSTA FILHO GERALDO, VON ZUBEN FERNANDO JOSE, BERGSON FERNANDES BARRETO, HENRI, TEIXEIRA COSTA FILHO, GERALDO, VON ZUBEN, FERNANDO, JOSE
Applicants: MONSANTO BRASIL, MONSANTO DO BRASIL S.A.
Application year: 1987
Main classification: A01N57
IPC codes: A01N25, A01N57