SOLID, PHYTOACTIVE COMPOSITIONS, METHODS OF USE AND METHODS OF PREPARATION

Abstract: Disclosed are solid, phytoactive, N-phosphonomethyl-N-­ carboxy-methyl compositions. Also disclosed are processes for the preparation of such compositions by (a) forming an initial mixture comprising a phytoactive N-­ phosphonomethyl-N-carboxymethyl compound, a solvent and a molten surfactant, the surfactant being solid at ambient tempera­ tures; (b) removing solvent from the initial mixture to form a final mixture at a temperature above the melting point of the surfac­ tant; (c) cooling said final mixture to a temperature below the melting point of the surfactant to form a N-phosphonomethyl-N-­ carboxymethyl composition which is solid at ambient tempera­ tures; and (d) processing said composition into particulate form, such as pellets, flakes, granules, or powders. Further disclosed is the use thereof in controlling vegetation.

Description: SOLID, PHYTOACTIVE COMPOSITIONS, METHODS OF USE AND METHODS OF PREPARATION This invention relates to novel, solid, phytoactive compositions comprising certain surfactants and phytoactive compounds containing the moiety: EMI1.1 and to methods of manufacture of such canpositions. The phytoactive compounds containing the moiety set forth above as Formula I are designated herein as N-phosphoncmethylul-carboxymethyl compounds or "PMCM" compounds. These canpounds and the moiety of Formula I will be further defined and illustrated hereinafter. For convenience, the phytoactive canpounds containing the moiety of Formula I will herein after be designated 9MCM compounds. A large nunber of phytoactlve PMCM compounds are known in the art. The term "phytoactive" as used in describing this invention means effective as a plant growth regulator, as a herbicide, as a defoliant or the like. Illustrative of such PMCM canpounds and their use are: U.S. Patent 3,455,675, Irani, July 15, 1969, entitled "Aminophosphonate Herbicides"; U.S. Patent 3,556,762, Hamm, January 19, 1971, entitled "Increasing Carbohydrate Deposition in Plants with Aninophosphonate 5"; U.S. Patent 4,405,531, Franz, September 20, 1983, entitled "Salts of N-Phosphonomethylglycine"; U.S. Patent 3,868,407, Franz, February 25, 1975, entitled "Carboxyalkyl Esters of N-Phosphonanethylglyc ine; U.S. Patent 4,140,513, Prill, February 20, 1979, entitled "Sodium Sesquiglyphosate"; U.S. Patent 4,315,765, Large, February 16, 1982, entitled "Trialkylsulfonium Salts of N-Phosphonanethylglycine;" U.S. Patent 4,481,026, Prisbylla, November 6, 1984, entitled "Aluminum NPhosphonumethylglycine and Its Use As A Herbicide", U.S. Patent 4,397,676, Bakel, August 9, 1983, entitled "N-Phosphonomethylglycine Derivatives"; and International Application WO 84/03607, Chevron Pre search Company, September 27, 1984, entitled Glyphosate-Type Herbicidal Cumposi- tions". These patents are illustrative and are incorporated herein by reference. Most of these patents also include descriptions of processes employed to prepare such compounds. The following patents provide additional process descriptions U.S. Patent 3,288,846, Irani et al., November 29, 1966, entitled "Process for Preparing Organic Phosphonic Acids"; U.S. Patent 4,507,250, Bakel, March 26, 1985, entitled "Process for Producing N-Phosphoncmethylglycine Acid"; U.S. Patent 4,147,719, Franz, April 3, 1979, entitled "Pro- cess for Producing N-fhosphorxaethylglycine" ; and U.S. Patent 4,487,724, Felix, December 11, t984, entitled "Process for Preparation N-Phosphonomethylglycine Salts". These patents are also incorporated herein by reference. PMCM compounds, in particular water soluble PMCM salts, are often difficult to obtain in a solid form. They can be difficult to crystallize and isolate from aqueous solutions. They can form glassy, noncrystalline solids which transform rapidly into wet cakes When exposed to the air. Commercial formulations of PMCM compounds are generally not sold in a solid form, but sold as aqueous solutions. These solutions often contain only about 50% PMCM compound. Oonsequently, there is substantial waste in terms of storage, transportation charges and container disposal. EMCM compounds in water are usually acidic and exhibit chelating properties. Iron and aluminum tend to inactivate the phytoactivity of the compounds. They can react with unlined or galvinized steel to prcduce hydrogen gas which can form a highly canbustible gas mixture. If ignited, this mixture can flash or explcde, which may cause serious personal injury. Therefore, aqueous solutions of the compounds are usually stored and transported in plastic or specially lined steel containers. It would be desirable to package and sell iMCM compounds in a solid form in order to realize substantial savings in terms of storage, transporation and container disposal charges and to avoid the problems associated with i3!1CM solutions. Representative patents generally disclosing wettable powders containing PMCM compounds include U.S. Patents 4,025,331; 4,414,158; 4,481,026; and 4,405,531. They broadly disclose wettable powders containing a EMCY canpound, an inert solid extender, and one or more surfactants. A disadvantage of such wettable powders is that the solid extender reduces the amount of active ingredients which can be transported in a container of a particular size. A further disadvantage is that many of the phytoactive canpounds desirably contained in such powders, particularly PMCM salts, are hygroscopic or deliquescent. Great care is needed in packaging, storage and use of such wettable powders. If a final user chooses to employ only a portion of such a powder, extensive precautions must be taken to ensure the stability of the remainder. It has now been found, however, that phytoactive PMCM canposi- tions are readily obtained in a solid form which is substantially nonhygroscopic or non-deliquescent. Illustrative of a preferred process in accordance with the invention for preparing such solid canpositions is the process of: (a) forming an initial mixture comprising a phytoactive PMCM compound, a solvent and a molten surfactant, the surfactant being solid at ambient temperatures; (b) removing solvent from the initial mixture at a temperature above the melting point of the surfactant to form a final mixture; (c) cooling the final mixture to a temperature below the melting point of the surfactant to form an N-phosphonomethyl-N-carboxymethyl com- Fosition which is solid at ambient temperatures; and (d) processing said composition into particulate form, such as pellets, flakes, granules, or powders. As used herein, the term "solid" refers to the physical state wherein the composition has a specific shape and volume ard resists deformation. The solid may be processed into any suitable particulate form, such as pellets, flakes, granules, or powder. The solid composition can subsequently be dissolved in a suitable diluent, usually and preferably water, at a remote field site, and applied to the plants upon which the composition's phytoactivity is to be directed. Any liquid-dispersible, phytoactive PMCM compound can be used in the compositions and processes in accordance with the invention The term "liquid-dispersibleW is used in a broad sense to encompass compounds which are soluble in a liquid as well as compounds which are merely dispersible. In preferred eibcdiments, the EMCM compound is liouid-soluble. In most preferred embodiments, it is water-soluble. The PMCM compounds may be represented by the formula EMI4.1 wherein Z is hydrogen, an organic moiety or an inorganic moiety. Pepre- sentative patents disclosing PMC! compounds wherein Z is other than hdro- gen include U.S. Patent Nos. 3,888,915; 3,933,946; 4,062,699; 4,119,430; 4,322,239; and 4,084,953. In preferred PMCM compounds, Z is hydrogen or an organic substituent. Representative organic substituents include methylene carboxylic; methylene phosphonic; methylene cyano; carbonyl, such as formyl, acetyl; benzoyl; perfluorcoacyl; and thiocarbonyl; ethylene, such as cyano; carba zoyl or carboxyl substituted ethylenel and benzene sulfonyl substituents. Representative patents disclosing compounds wherein the nitrogen contains three organic substituents include U.S. Patent Nows. 3,455,675; 3,556,762; 4,312,662; 4,216,727; 3,988,142; 3,970,695; 4,180,394; 4,047,927; 3,853,530; 4,203,756; 3,991,095; and 3,996,040. A preferred tertiary nitrogen substituted PMCM compound is N,N-bis-(phosphonomethyl)glycine. Those EMCM compounds wherein Z is hydrogen are most preferred when the phytoactivity desired is herbicidal activity. Representative R's include halogen, NHOH, -oR2, R21 SR2 and QM, where R1 is independently selected from hydrogen; alkyl or hydroxyalkyl, preferably containing less than about 5 carbon atoms; alkenyl, preferably containing less than about 5 carbon atoms; or phenyl moieties. R2 is independently selected from hydrogen; alkyl; hydroxyalkyl; or chloroalkyl, preferably containing less than about 5 carbon atoms; alkoxy, preferably containing less than about 5 carbon atoms; alkyleneanine, preferably containing less than about 12 carbon atoms; phenyl; or benzyl moieties. M is selected from hydrogen and agriculturally acceptable saltforming moieties such as alkali metal, alkaline earth metal, stannic, ammonium, organic ammonium, alkylsulfonium, alkylsulfoxonium, alkylphosphonium moieties or combinations thereof. Representative patents disclosing at least some of such compounds include U.S. Patents 3,799,758; 4,397,676; 4,140,513; 4,315,765; 3,868,407; 4,405,531; 4,481,026; 4,414,158; 4,120,689; 4,472,189; 4,341,549; and 3,948,975. The above patents are herein incorporated by reference. Illustrative of agriculturally acceptable salt-forming moieties represented by M are the alkali metals having atcmic weights of from 22 through 133, inclusive, such as sodium, potassium or rubidium, the alkaline earth metals having atomic weights of from about 24 through 88, inclusive, such-as magnesium or calcium; ammonium and aliphatic ammonium, wherein the aliphatic arrrnonlum is primary, secondary, tertiary or quater nary and preferably wherein the total number oi carbon atoms does not exceed more than about 12; phenylammonium; trialkylsulfonium, preferably wherein the total number of carbons in the three alkyl substituents does not exceed more than about 6, sich as trimethylsuifonium, ethyldimethylsulfonium, propyldimethylsulfonium and the like; trialkylsulfoxonium, preferably wherein the total number of carbon atoms in the three alkyl substituents does not exceed more than about 6, such as trimethylsulfoxonium, ethyid imethylsulfoxonium, propyldimethylsulfoxonium and the like; tetraalkylphosphonium, ethyltrimethylphosphonium, propyltrimethylphosphon and and the like. It should be noted that the alkaline earth metal salts, while agriculturally acceptable, provide only marginal herbicidal activity. In preferred compositions according to this invention, M is independently selected frcm the above-described agriculturally acceptable salt-forming moieties and hydrogen. In more preferred compositions, H is an alkali metal, ammonium, monoalkylammonium, or trialkylsulfonium moiety. In most preferred compositions only one M is an alkali metal, amnonium, monoalkyl ammonium, or trialkylsulfonium moiety, while the other two M's are hydrogen. Representative most preferred compositions include isopropylamine N-phosphonomethylglycine , trimethylslfonium N-phosphonomethylglycine and sodium sesquiN-Fhosphorxmethylglyc ine. Combinations of two or more EMCM compounds can be employed in the compositions and processes in accordance with the invention. The choice of the particular surfactant to be used with a PHCM compound is important. The choice of a particular surfactant to be used in connection with a particular PMCM compound will be easily made by one skilled in the art, without undue experimentation based on the teachings of this application. W-hatever surfactant is used, it must be a solid at ambient temperature, i.e, it must have a high melting point. Preferred surfactants have a melting point above 50 C. The surfactant should also not be hygroscopic or deliquescent. When solid, the surfacant should be readily soluble or dispersible in the diluent chosen by the ultimate user of the phytoactive composition. In preferred embodiments, the solid surfactant is soluble in water. The surfactant should cause a minimum amount of foaming, particularly urner vacuum, when the solvent is removed during the processes in accordance with the invention and should cause a minimum amount of foaming when the final prcduct is subsequently mixed with the diluent. It is particularly important that the surfactant is solid at ambient temperatures. In practical terms, it must be solid at the highest temperatures to which the solid produce may be exposed before it is mixed with the diluent by the ultimate user. Such temperatures are generally in the range of from about -20 to 50"C. Preferred surfactants for use in the invention are nonionic block copolymers of alkyl oxides having a functional group EMI7.1 where R3 and R4 are the same or different and are selected from hydrogen, EMI7.2 and wherein R7 is selected from an alkyl having from about 8 to about 30 carbon atoms or an alkylaryl group, wherein the alkyl portion of the alkylaryl group ranges from about 8 to about 30 carbon atoms, and mixtures thereof, and wherein m ranges from about 20 to about 200, n ranges from about 0 to about 10, and m + n is equal to or greater than about 25. Examples of R7 include sorbitan, fatty radicals such as coco, oleyl, palmityl, tallow, stearyl, lauryl, soya, castor, nonylphenoxy, d inonyl phenoxy, octylphenoxy, and d ioc tyl phenoxy. Preferred nonionic surfactants for use in the compositions of the invention include Pluronic surfactants, such as Pluronic F-38, F-68, F-77, F-87, F-88, F-89, F-108 and F-127. The Pluronic surfactants are available commercially (EFSF), and comprise ethylene oxide or propylene oxide block copolamers. The advantages of the use of a nonionic surfactant in the process and compositions of this invention are that they are generally inexpensive readily available, low or non-irritating, often of low toxicity to mammals and generally, low or non-foaming when under vacuum in a molten state. Other surfactants can be used, such as cationic, anionic, or amphoteric surfactants. However, they may give rise to foaming. They also may be more toxic to mammals. Such other surfactants include Emcol CC-57 (cationic), Arquad C-50 (cationic), Ethomeen 18/12 (cationic), Ethomeen 18/15 (cationic), Ethomeen 18/60 (cationic), Ethomeen T/60 (cationic), Alkaphos K-380 (anionic) and Witconate AOK (anionic). Mixtures of various non-ionic surfactants, or nonionics with cationic, anionic or amphoteric surfactants, can also be used if desired. The following surfactants, among others, have been found to be useful in the processes and compositions of this invention. TABLE I Surfactant Manufacturer Structure/Type m.p. C Trycol 5946 Emery tridecyl alcohol EQ* 39 Trycol 5967 Emery lauryl alcohol EO Trycol 5964 Emery lauryl alcohol EO 39 Trycol 6954 Emery nonylphenol 15 EO Trycol NP-20 Emery nonylphenol 20 EO 34 Trycol IAL-1 2 Emery lauryl alcohol 12 EO 32 Trycol LAL-23 Emery lauryl alcohol 23 EO 40 Trycol OAL-23 Emery alkyl alcohol 23 EO 47 Emery 6873 Emery Trycol 6988 Emery dinonylphenol 15 EO 55 Pluronic F-88 BASF block EO, PO** copolymer 54 Industrol BASF polyethylene glycol fatty acid 48 MS-40 ester 40 EO Iconol DNP-150 dinonylphenol 15 EO 55 Pluronic F-127 BASF block EO, PD copolymer 56 Pluronic F-108 BASF block EO, PO copolymer 57 Plurafac A-39 BASF linear alcohol ethoxylate 56 Alkasurf S-40 Alkaril stearic acid ethoxylate 40 EO 46 Alkasurf TA-50 Alkaril tallow alcohol ethoxylate 50 EO 47 Alkasurf OP-40 Alkaril octylphenol ethoxylate 40 EO 48 Alkasurf LAD-23 Alkaril fatty alcohol ethoxylate 23 EO a7 Alkatronic Alkaril block EO, PO copolymer 52 PGP 18-8 (80% EO) Alkatronic Alkaril block EO, PO copolymer PGP 23-8 (80% EO) Alkatronic Alkaril block, EO, PO copolymer 57 PGP 33-8 (80% EO) TOET BP-1 Thompson- 28 Hayward T-DET N-100 Thompson- nonylphenol 100 EO 50 Hayward Staley APG 91-3 A.E. Staley alkyl polyglyoside (solid form) * EO = ethylene oxide ** PO = propylene oxide Additional classes of surfactants which can be used in accordance with the invention are listed in Table II below. TABLE II EMI10.1 <tb> Surfactants <SEP> Type <SEP> Structure <tb> <SEP> 0 <tb> Alkamul <SEP> s <SEP> fatty <SEP> acid <SEP> ethoxylate <SEP> II: :O(CH2CH20)xCR2CR20H <tb> Industrol <tb> Alkasur <SEP> f <tb> Trydet <tb> <SEP> O <SEP> 0 <tb> <SEP> n <SEP> 11 <tb> Alkamuls <SEP> di-fatty <SEP> acid <SEP> esters <tb> Industrol <tb> Emerest <tb> Alkamuls <SEP> sorbitan <SEP> ester <SEP> ethoxylate <SEP> BO(CH2CHzO)W <SEP> (CCH2CH2) <tb> Emsorb <SEP> Q <tb> <SEP> O^CH(oCHzCH2)yQH <tb> <SEP> CH2(OCH2CH2)CR <tb> <SEP> 0 <tb> <SEP> X <SEP> (CH2CHzO)xcE2cH2 <tb> Alkaminox <SEP> anine <SEP> ethoxylate <tb> Irymeen <SEP> \(CHzCE2O)yCH2CH2OH <tb> <SEP> (cH <SEP> ) <SEP> yCE2CH <tb> <SEP> O <SEP> (CE <SEP> ) <SEP> XCH2CH2 H <tb> <SEP> 0 <tb> <SEP> II <tb> Alkasurf <SEP> castor <SEP> oil <SEP> ethoxyl <SEP> ates <SEP> CH3(CH2)sCECH2CH=CH(CH2)7CCCH2 <tb> Indus <SEP> rol <SEP> RD-; ;CH <tb> <SEP> H2 <tb> Pluronic <SEP> polyoxypropyl <SEP> ene <SEP> glycol <SEP> Who <SEP> (CR2CH2O),-(CCH20 <SEP> )y-(CH2CII2O <SEP> )2-H <tb> <SEP> ethoxylate <SEP> CH3 <tb> <SEP> o <SEP> Z <SEP> (C82CH2O),H <tb> Alkamidox <SEP> alkanolamice <SEP> ethoxylates <SEP> SCN <tb> Emid <SEP> (CH2CH2o)yH <tb> Alkasurf <SEP> alcohol <SEP> ethoxylates <SEP> R-(OCH2CH2)X-OH <tb> Inuustrol <tb> Plurafac <tb> Iconol <tb> Trycol <tb> Some surfactants which are solid at ambient temperatures foam. The foaming problem may arise both during the initial preparation of the composition, particularly if the solvent is removed under vacuum, and when the final product is subsequently mixed with a diluent by the ultimate user. Therefore, some embodiments of the invention include an anti-foaming agent. The anti-foaming agent may be added any time before the solvent is removed. Representative of useful anti-foaming agents include compounds such as Silcolapse 5008 (silicone-based anti-foam) and Anti-foam Emulsion Q-94 (SWS Silicones Corp.). In addition to the PMCM compound, the surfactant and the antifoaming agents, the composition can also include other conventional adjuvants such as drying aids, heat stabilizers, ultraviolet absorbers, dispersants, wetting agents, and other agriculturally acceptable materials. Representative drying aids include Microcel E, Aerosil 200, and Hi-SilX 233. Representative heat stabilizers include phenylenediamines, phenazine, butylated hydroxy toluene. Representative ultraviolet absorbers include Tinuvin 770, Tinuvin P, and dinitroanilines. The ratio of PMC! compound to surfactant varies over a wide range. Since it is known that the choice of a particular surfactant can affect the photoactivity of the EMC! compounds used in accordance with this invention, the desired activity of the solid composition should be considered when selecting a particular surfactant. As much surfactant as desired may be employed so long as the products dissolve totally or disperse readily in the diluent prior to the apolicaton. For cost considers tions, a minimum of surfactant should be used which still enables tbe objects of the invention to be obtained, e.g., the production of a solid product which is substantially non-hygroscopic. The ratio of EMCM compound to surfactants by weight, is typically from about 10:1 to about 1:10. me preferred ratio is from about 4: 1 to about 1:2. The most preferred ratio is from about 2:1 to about 1:1. Representative formulations of the compositions of this invention are as follows. The formulations are based on percent by weight, unless otherwise noted. 69.3% trimethylsulfonium salt of N-phosphonomethylglYcine 30.7% F-108 (m.p. 57 C) 100% Total 69.3% isopropylamine salt of N-phosphonomethylglycine 30.7% Tetronic 909 (m.p. 590C) 100% Total 69.3% isopropylamine salt of N-phosphonomethylglycine 30.7% Pluronic F-108 (m.p. 57 C) 100% Total The solid compositions in accordance with this invention are characterized in that the PMCM compound forms an intimate mixture with the surfactant. The PMCM compound is initially dispersed throughout a surfactant matrix. It is believed that such an intimate dispersion prevents absorption of moisture by the PMCM compounds. The compositions of this invention can be prepared in any suitable manner. A preferred process, however, comprises first preparing a mixture containing the PMCM compound and the solvent. In preferred edbod- iments, the PMCM compound is dissolved in the solvent. In other embody ments, the P!GM compound is dispersed therein. In some embodiments, the mixture is prepared by forming the PMCM compound in situ. For example, in sane embodiments, N-phosphonomethylgly- cine is reacted with a desired base, in the presence of water, to form an aqueous solution containing the PMCM compound. In preferred embcdiments, solutions of isopropylanine N-phosphoncmethylglycine can be prepared in this manner. The choice of the solvent for use in accordance with the process of the invention is not critical, but the solvent must meet certain requirements. The solvent must be capable of dissolving or dispersing a desired EMCM compound at the temperature used to form the initial mixture, without adversely effecting the PMCM ccmpound's phytoactivity. The greater the solublity or ease of dispersibility of the PMCM compound in solvent, the less solvent will be required and the subsequent removal of solvent will be facilitated. It is preferred that the normal boiling point of the solvent is greater than the melting of the particular surfactant chosen. However, what is most important is that the solvent be removed at a temperature greater than the surfactant's melting point. Consequently, where the normal boiling point of the solvent is less than the melting point of the surfactant, the solvent must be remcved under elevated pressure. Preferred solvents include water and polar organic solvents, such as methanol, ethanol, isopropyl alcohol and acetone. Water is most preferred. The third component of the initial mixture is the surfactant. The surfactant may be added by conventional techniques to the solvent before, during or after the addition of the PMCM compound. Preferably, the surfactant is added in the molten state, although in scme embodiments it is initially merely dissolved or dispersed in the solvent and the temperature then raised above the melting point of the surfactant. Initial use of a molten surfactant permits easy mixing and can aid in reducing the amount of solvent, which is required. In those embodiments where the molten surfactant is itself capable of dissolving or dispersing the desired PMCM compound, it can be employed in lieu of the solvent. In order to form or maintain the molten surfactant, the lower limit on the temperature of the initial mixture is the melting point of the surfactant. Ihe upper limit is the temperature at which a particular PMCM ccmFound, surfactant or other additives will decompose. When tri alkyl sul foni un-N-pho sphoncmethylglye ines are chosen as a FMCM compound, temperatures in the range of 30 to 110 C are generally employed. The solvent is then removed from the initial mixture. Any solvent removal technique can be employed, so long as the temperature is below the decomposition temperature is above the melting point of the surfactant. Representative techniques include heating and vacuum techniques and ccmbinations of both. Fbr example, the final mixture can simply be heated to a temperature sufficient to evaporate the solvent of the above requirements are met. The temperature at which the solvent is evaporated is a function of temperature, absolute pressure and composition of the mixture. Thus, if a reduced pressure is employed, removal of the solvent can be achieved at lower temperatures. A preferred device for solvent removal at reduced pressure is an industrial-type film evaporator. Because the residence time of the product in the device is very short, any decomposition which may tend to occur is minimized. In carrying out the process of this invention, atmospheric con- ditions- are most preferred for solvent removal because they eliminate the use of special equipment, or special techniques for maintaining a vacuum and for removing the resulting solid composition from such equipment. As the solvent is removed at temperatures above the melting point of the surfactant and higher concentrations of surfactant are contained in the mixture, a viscous final mixture is formed. Upon cooling, the final mixture readily solidifies. It is not necessary to remove all the solvent from the final mixture. All that is required is that sufficient solvent be removed so that the final ccmposlticn solidifies upon cooling. In preferred embcdiments, however, substantially all the solvent is removed. The resulting solid composition can then be processed into any suitable particulate form, such as pellets, flakes, granules, or powder, by conventional techniques. As will be readily appreciated by one skilled in the art, the size of the final particle will affect the ease of solution or dispersion of the final product in the diluent by the ultimate user. Generally, the ease of solution or dispersion increases as particle size decreases. In contrast, however, the ease of handling thefinal product increases as particle size increases. The more soluble or dispersible the solid composition, the larger the particle size that can be employed. In preferred ebbed iments, the final product is processed into particles ranging from powders having a diameter of about 3 to about 15 microns, to granules, having a diameter of about 8 to about 30 mesh to flakes. The following examples illustrate production of the compositions of the invent on in accordance with the process described herein. All percefltTes are based or weight, unless othe- ise clearly indicate. EXAMPLE I In a laboratory Buchi Rotavator, 12. 5 grams (g) of IETRONIC9 908 surfactant (block copolymer of ethylene oxide and propylene oxide from BASF), m.p. 58 C, were melted in a 200 milliliter (ml) round-bottom flask at 70 C. To the molten surfacant 42.5 g of a 58% aqueous trimethylsulfonium-N-phosphonomethylglycine solution at ambient temperature were added slowly while the elevated temperature was maintained. The mixture was heated slowly to 95 C under vacuum (5 tntttg absolute pressure) and mcderately rotated to control ebullition. After 1/2 hour, substantially all the water had been removed and the mixture was solidified by cooling to room temperature. The solids obtained were removed from the flask with a spatula and ground into a powder with a pestle and a mortar under nitrogen. A sample of the powder left in an open crucible did not deliquese. EXXMPLE II A composition was prepared as in Example I, except for using 12.5 g of IGEPAL DM 970 (dialkylphenoxypoly(ethylenoxy)ethanol from GAF Corp.) as the surfactant. A solid was obtained which did not deliquesce upon standing in the open. EXAMPLE III A composition was prepared as in Example I, except for using 15 g of ICONOL DNP 150, m.p. 55 C, as the surfactant, 1 g of Hi-SilX (fumed silica from PPG), 2 drops of anti-foaming agent (Silcolapse 5008) and evaporating at 10 C for one-half hour at 1 mmHg (absolute). A solid was obtained which did not deliquesce upon standing in the open. EXAMPLE IV A composition was prepared as in Example I, except for using 15 g of PLURONICR F-108, m.p. 56 C, as the surfactant and evaporating at 950C for 1/2 hour at 10 mmHg. The viscous paste obtained was solidified by cooling to rocm temperature. It did not deliquesce upon standing in the open. EXAMPLE V A composition was prepared as in Example IV, except for using a mixture of 2 surfactants (10 g of PLURONICR 17R8 and 5 g of TRYCOLR 5946, ethoxylated alkylphenol surfactant from Emery) and evaporating at 5 mmHG absolute pressure (final condition) and 100 C for 15 minutes. The viscous paste obtained solidified after cooling to room temperature. It did not deliquesce upon standing in the open. EXAMPLE VI A composition was prepared as in Example I, except for using 15 g of PLURONICR F-108, m.p. 56 C, 1 g of Hi-SilR (fumed silica from PPG) and evaporating at 5 mmHg absolute pressure (final condition) at 100 CC for 1/2 hour. The product obtained solidified quickly when cooled. It did not deliquesce upon standing in the open. EXAMPLE VII A composition was prepared as in Example I, except for using 25 g of PLURAFAC A-39 (a linear alcohol ethoxylate surfactant from BASF), m.p. 56 CC, as the surfactant and evaForating at 1 mE5g absolute pressure (final condition) at 100 CC for 1/2 hour. The viscous liquid obtained solidified when cooled to room temperature. It did not deliquesce upon standing in the open. EXAMPLE VIII In a laboratory Buchi Rotavator, 12.5 g of IGEPALR DM 970 surfactant (trialkylphenoxy poIy( ethylenny) ethanol from GAF Corp.) were melted in a 200 ml round-bottom flask at 70 CC. To the moleten surfactant, 47.8 g of a 53.5 wt. % isopropylamino-N-phosphonomethylglycine aqueous solution Rodeo from Monsanto) at ambient temperature was maintained. The mixture was then heated slowly to 95 CC under vacuum (5 mmHg absolute pressure) and mcderately rotated to control the ebullition. After 1/2 hour substantially all the water had been rencved and the mixture was cooled to room temperature. The solids obtained were removed from the flask with a spatula and ground into a powder with a pestle and a mortar under nitrogen. A sample of the powder left in an open crucible did not deliquesce. EXAMPLE IX A composition was prepared as in Example VIII, except for using 12.5 g of PLURCNIC 17R8 surfactant (block copolymer of propylene oxide and ethylene oxide from BASF, Wyandotte) and evaporating at 90 C for 1/2 half hour at 5 mmHg (absolute). The resulting solid product did not deliquesce. EXAMPLE X Twelve additional powders were prepared. All the solids obtained were ground into water-soluble powders. The powders were prepared as follows: (a) Six different surfactants (15 g for each powder) were mixed with 1 g of Hi-Sile (fumed silica from PPG) and 42.5 g of a 58% aqueous solution of trimethylsulfonium-N-phosphonomethylglycine and worked-up as in Example VI. Table III indicates the surfactants used. TABLE III Surfactants Melting Average Viscosity Pow- point Molecular &commat; 77 C der Tradename Mfgr. ( C) Weight (ops) Class or Formula 1 Pluronic 108 BASF 57 14,600 2800 Polyol 2 TetrinicX 909 BASF 59 30,000 8200 Polyol 3 PluracolX E8000 BASF 61 7,500 - Polyethylene glycol 4 PlurafacX A-39 BASF 56 2,600 125 Linear alcohol ethoxyl ate 5 Iconol DNP-150 BASF 55 6,900 - Dinonylphenol ethoxylate 6 Tricol 6954 EMery 54 - - bbnylphenol ethoxyl ate (b) In addition, six powders were prepared from a combination of two surfactants, Iconol DNP-150, m.p. 55 C and TrycolR 6954, m.p. 54 C, at 3 different levels: 15, 20 and 25 g with 42.5 g of a 58 wt. % solution of trimethylsulfonium-N-phosphonomethylglycine as in Example VI. In each instance a dry powder was obtained. EXAMPLE XI A composition was prepared as in Example I, except for using 300 g of Pluronic F-88 (block copolymer of propylene oxide) and ethylene oxide (from BASF, m.p. 54 C) as the surfactant, 574 g of a 58% aqueous trimethylsulfoniun N-phosphonomethylglycine solution, 10 drops of Silcolapse 5008 and mixing in a 2 liter round-bottomed flask. The solid obtained did not deliquesce upon standing in the open. The phytoactive compositions of this invention are effective when subsequently dissolved or dispersed in a suitable diluent, preferably water, and applied to thelocus desired by spray or other conventional menas. Conventional adjuvants, including wetting agents, penetrating agents, spreading or sticking agents, carriers, extenders and conditioning agents, such as dispersing agents can be added to the final solution or dispersion. the following examples demonstrate the herbicidal effectiveness of the compositions of the invention. The effectiveness was cbserved by comparing the extent of weed control in test containers treated with the PMCM compositons in accordance with the invention with that occurring in similar control containers. The soil used in these tests was a sandy loam soil from the Livermcre, California area. The soil was treated by the addition of 17-17-17 fertilizer (N P2O5-K2O on on a weight basis), amounting to 50 ppn by weight, with respect to the soil, and CAPTANR, a soil fungicide. The thus treated soil was then placed in plastic tubs, 6 inches in diameter and 5 inches deep with drainage holes. Johnsongrass rhizomes, Bermuda grass cuttings and purple nutsedge tubers were planted in the test containers. The test weeds were as follows: Conrmon Name Scientific Name Weeds: A. Johnsongrass Sorghum halepense B. Bermuda grass Cynodon dactylon C. purple nutsedge Cyperus rotundus Sufficient stock or cuttings were planted to produce several seedlings per container. After planting, the containers were placed in a greenhouse maintained at 21 to 30 C and watered daily with a sprinkler. A variety of PMCM compositions based on trimethylsulfoniun N-phosphonomethylglycine were sprayed on the seedling approximately 35 days after planting. The compositions are shown in Table IV. Composition 1 was a liquid formulation. Compositions 2 through 13 were solid compositions, prcduced in accordance with the invention. Each composition was dissolved in 400 ml of water and than a 40 ml aliquot of the resulting solution was used for spraying at the rates indicated in Table IV. Approximately 28 days after the spraying, the degree of weed control was rated and recorded as a percentage control compared to the control exhibited on the same species of the same age which had not been sprayed. The rating ranged from 0 to 100%, where 0 equaled no effect on plant growth when compared to the untreated control, and 100 equals complete killing of the test weeds. The results are listed in Table IV. TABLE IV Percent Cbntrol Ratings Weight Rate Johnson Bermuda Purple Cmposition in grams (1b/A) grass grass Nutsedge 1. Herbicide 3.84 1/4 65 65 Ethaquod 12 1.54 1/2 97 99 55 1 - - 93 2. Herbicide 3.84 1/4 40 15 Pluronic F-I 08 2.30 1/2 85 55 45 1 - - 93 3. Herbicide 3.84 1/4 25 10 Tetronic 909 2.30 1/2 80 45 40 1 - - 85 4. Herbicide 3.84 1/4 10 15 Pluracol E8000 2.30 1/2 75 50 35 1 - - 80 5. Herbicide 3.84 1/4 15 25 Plurafac A-39 2.30 1/2 80 60 25 6. Herbicide 3.84 1/4 15 15 Iconol DNP-150 2.30 1/2 70 60 25 1 1 - - 75 7. Herbicide 3.84 1/4 35 20 Trycol 6954 2.30 1/2 80 70 25 8. Herbicide 3.84 1/4 35 20 Iconol DWP-150 2.68 1/2 75 70 35 1 - - 85 9. Herbicide 3.84 1/4 25 35 Iconol DNP-150 3.07 1/2 75 70 45 1 - - 80 10. Herbicide 3.84 1/4 25 35 Iconol DNP 150 3.84 1/2 75 70 50 1 - - 80 11. Herbicide 3.84 1/4 35 35 Inocol DNP-150 3.84 1/2 85 80 35 1 - - 75 12. Herbicide 3.84 1/4 40 35 Plurafac A-39 3.07 1/2 85 75 35 1 - - 88 13. Herbicide 3.84 1/4 55 40 Plurafac A-39 3.84 1/2 95 98 35 1 - - 93 control # # # # The amount of the composition which constitues a phytoactive amount depend on the nature of the plants and the effect desired. me rate of application generally varies from about 0.01 to about 50 pounds of PMCM compound per acre, preferably about 0. 1 to about 25 pounds per acre with the actual amount depending on the overall cost and the desired results. It will be readily apparent to one skilled in the art that compositions exhibiting lower phytoactivity will require a higher application rate than the more active compounds for the same degree of effectiveness.

Claims: Claims 1. A solid, substantially non-hygroscopic, phytoactive composition comprising an intimate mixture of a phytoactive N-phosphonomethyl-N- carboxymethyl compound and a surfactant where the surfactant is solid at ambient temperature. 2. A composition in accordance with Claim I wherein the N-phos- phonomethyl-N-carboxymethyl compound is of the formula EMI22.1 and where M is independently selected from hydrogen and agriculturally acceptable salt-forming moieties. -3. A composition in accordance with Claim 2 wherein the N-phos- phonomethyl-N-carboxymethyl compound is N-phosphonomethylglycine. 4. A composition in accordance with Claim 2 wherein the N-phos- phonomethyl-N-carboxymethyl compound is trimethylsulfonium-N-phosphonomethylglycine. 5. A composition in accordance with Claims 1, 2, 3 or 4 wherein the surfactant is an ethylene oxide or propylene oxide block copolymer. 6. A composition in accordance with Clams 1, 2, 3 or 4 wherein the surfactant is a block copolyner of alkyl axides having a functional group EMI22.2 wherein R and R' are independently selected from hydrogen, EMI22.3 EMI22.4 EMI22.5 wherein R" is selected from the alkyl group having from about 8 to about 30 carbon atoms or alkylaryl groups wherein the alkyl portion of the alkylaryl group ranges from about 8 to about 3C carbon atoms, and mixtures thereof, and wherein m ranges from about 20 to about 200, n ranges from about 0 to about 10, and m + n is equal to or greater than about 25. 7. A method for the preparation of a solid, phytoactive, canposition comprising: (a) forming an initial mixture canprising a phytoactive N-phos- phonomethyl-N-carboxylnethyl compound, a solvent and a molten surfactant, the surfactant being solid at ambient temperatures; (b) removing sovlent from said initial mixture to form a final mixture at a temperature above the melting point of the surfactant; and (c) cooling said final mixture to a temperature below the melting point of the surfactant to form a N-phosphoncmethyllU-carboxymethyl ccmEosition which is solid at ambient temperature. 8. A method in accordance with Claim 7 wherein the N-phosphono methylaN-carboxymethyl compound is of the formula EMI23.1 and where M is independently selected from hydrogen and agriculturally acceptable salt-forming moieties. 9. A method in accordance with Claim 8 wherein the N-phosphono methyl-N-carboxymethyl compound is N-phosphonomethylglycine. 10. A method in accordance with Claim 8 wherein the N-phos phoncmethyloN-carboxEmethyl compound is isopropylamine-N-phosphonomethyl- glycine. 11. A method of controlling vegetation wherein a phytoactive amount of a composition in accordance with claim 1, optionally in admixture with a diluent, is applied thereto.

Inventors: CHAN, JIMMY HUA-HIN, DJAFAR, ROGER RACHID
Applicants: STAUFFER CHEMICAL COMPANY
Application year: 1986
Main classification: A01N57
IPC codes: A01N25, A01N57