Claims
- 1. A method for preparing a stable aqueous suspension concentrate composition of pendimethalin, the method comprising: adding a surfactant and an antifoaming agent to hot water having a temperature of about 50.degree. C. to 80.degree. C.; emulsifying molten pendimethalin in said hot water; and cooling the hot emulsion to a temperature of less than about 35.degree. C.
- 2. The method according to claim 1, wherein said method prepares the stable composition of pendimethalin comprising, on a weight to weight basis, from about 4.0% to 100% orange crystal form and from about 0 to 96% yellow crystal form.
- 3. The method according to claim 1, wherein the pendimethalin-surfactant-antifoaming agent mixture has a droplet size of about 2 microns to 10 microns.
- 4. The method according to claim 3, further comprising: agitating while cooling the hot emulsion.
- 5. The method according to claim 4, further comprising: milling the emulsion following said cooling and said agitating.
- 6. The method according to claim 5, further comprising: adding an antifreezing agent or a preservative prior to milling the emulsion.
- 7. The method according to claim 6, wherein the molten pendimethalin is emulsified in hot water further containing at least one secondary herbicide which is water soluble or has a melting point greater than 70.degree. C.
- 8. The method according to claim 1, further comprising: adding at least one secondary herbicide which is water soluble or has a melting point greater than 70.degree. C. and an additional coformulant following said cooling of the emulsion to a temperature of less than about 35.degree. C.
- 9. The method according to claim 1, further comprising: adding a suspending agent to the hot water before or after emulsifying the molten pendimethalin.
- 10. The method according to claim 2, further comprising: milling the hot emulsion while cooling to a temperature of about 20.degree. C. to 25.degree. C.
- 11. The method according to claim 10, further comprising: aging the cooled mixture for about 0.5 hour to 48.0 hours.
- 12. The method according to claim 11, further comprising: adding 0% to 50.0%, on a weight to volume basis, of one or more secondary herbicides which are water soluble or have a melting point greater than 70.degree. C. and milling a second time.
- 13. The method according to claim 12, further comprising: adding a preservative, an antifreezing agent, an additional surfactant or a suspending agent.
- 14. The method according to claim 13, wherein the surfactant is an ethylene oxide/propylene oxide condensate; an alkyl,aryl-ethoxylate an aryl,aryl-ethoxylate or a derivative thereof; a lignosulfonate; a cresol-formaldehyde condensate; a sulfonated cresol-formaldehyde condensate; a naphthalene-formaldehyde condensate; a sulfonated naphthalene-formaldehyde condensate; a polycarboxylate or a derivative thereof; or a mixture thereof.
- 15. The method according to claim 14, wherein the surfactant is an alkyl, arylethoxylate, a triethanolamine or potassium salt of polyarylarylethoxylate phosphate, a polyarylarylpolyoxyethylene phosphoric acid, sodium cresol-formaldehyde condensate, sodium salt of sulfonated cresol-formaldehyde condensate or a mixture thereof.
- 16. The method according to claim 15, wherein the suspending agent is a polysaccharide gum or a cellulose derivative.
- 17. The method according to claim 16, wherein the polysaccharide gum is Xanthan gum, guar gum, gum arabic or a mixture thereof.
- 18. The method according to claim 17, wherein the antifreezing agent is ethylene glycol, propylene glycol, glycerine, urea or a mixture thereof.
- 19. The method according to claim 18, wherein said preservative is a 38% formaldehyde solution, methyl or propyl parahydroxybenzoate, 2-bromo-2-nitro-propane-1,3-diol, sodium benzoate, glutaraldehyde, o-phenylphenol, benzisothiazolinone, 5-chloro-2-methyl-4-isothiazolin-3-one, pentachlorophenol, 2,4-dichlorobenzylalcohol or a mixture thereof.
- 20. The method according to claim 19, wherein the secondary herbicide is isoproturon, linuron, metoxuron, chlortoluron, diuron, neburon, metobromuron, methabenzthiazuron, prometryn, atrazine, terbuthylazine, cyanazine, quinmerac, 2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)nicotinic acid or a water soluble salt thereof, 5-methyl-2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl) nicotinic acid or a water soluble salt thereof, 5-ethyl-2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl) nicotinic acid or a water soluble salt thereof, 2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-y l)-3-quinoline acid or a water soluble salt thereof, 2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)-5-(methoxymethyl) nicotinic acid or a water soluble salt thereof, or an isomeric mixture of methyl 6-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)-m-toluate and methyl 2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)-p-toluate.
- 21. The method according to claim 20, wherein said method prepares a stable composition comprising, on a weight to volume basis, about 5.0% to 50.0% pendimethalin, up to about 50.0% of the secondary herbicide, about 2.0% to 20.0% sodium cresol-formaldehyde condensate, sodium salt of sulfonated cresol-formaldehyde condensate, alkyl,arylethoxylate, triethanolamine or potassium salt of polyarylarylethoxylate phosphate, polyarylarylpoly-oxyethylene phosphoric acid or a mixture thereof, about 2.0% to 20.0% ethylene glycol, propylene glycol or urea, about 0.05% to 1.0% siliconic antifoaming agent, about 0.05% to 2.5% Xanthan gum, about 0.01% to 2.5% preservative and sufficient water to total 100%.
BACKGROUND OF THE INVENTION
This application is a continuation-in-part of copending application Ser. No. 08/173,809, filed Dec. 27, 1993, which is a continuation-in-part of two applications, (1) Ser. No. 07/395,925, filed Aug. 18, 1989, now U.S. Pat. No. 5,283,231, which is a division of application Ser. No. 07/045,458, filed May 7, 1987, now U.S. Pat. No. 4,875,929, which in turn is a continuation-in-part of application Ser. No. 06/867,107, filed May 23, 1986, abandoned and (2) Ser. No. 07/385,028, filed Jul. 25, 1989, abandoned, which is a division of application Ser. No. 7/045,457, filed May 7, 1987, now U.S. Pat. No. 4,871,392, which in turn is a continuation-in-part of application Ser. No. 06/867,106, filed May 23, 1986, abandoned.
US Referenced Citations (14)
Foreign Referenced Citations (2)
Number |
Date |
Country |
163598 |
Dec 1985 |
EPX |
190995 |
Aug 1986 |
EPX |
Non-Patent Literature Citations (3)
Entry |
The Agrochemicals Handbook, 1983, Old Working (Surrey), Unwin Brothers Ltd., p. A314/Oct. 1983. |
The Agrochemicals Handbook, 2nd ed., England, 1987, The Royal Society of Chemistry, p. A314/Aug. 1987 (both sides). |
The Merck Index, 10th ed., Merck & Co., Inc., p. 1016, No. 6936, 1983. |
Divisions (2)
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Number |
Date |
Country |
Parent |
45458 |
May 1987 |
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Parent |
45457 |
May 1987 |
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Continuation in Parts (5)
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Number |
Date |
Country |
Parent |
173809 |
Dec 1993 |
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Parent |
395925 |
Aug 1989 |
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Parent |
867107 |
May 1986 |
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Parent |
385028 |
Jul 1989 |
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Parent |
867106 |
May 1986 |
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