Herbicide compositions comprising suspension concentrate with glyphosate acid, methods of preparation, and methods of use
Described are suspension concentrates that include glyphosate acid, herbicide compositions prepared therefrom, and methods of making and using each.
1. A herbicide application composition comprising
a suspension concentrate comprising glyphosate acid, and
acidifying agent in an amount so the pH of the herbicide application composition is below the pKa of glyphosate acid.
2. The composition of claim 1 wherein the pH of the herbicide application composition is below about 2.6.
3. The composition of claim 1 wherein the herbicide application composition does not contain sulfuric acid.
4. The composition of claim 1 comprising acidifying agent selected from the group consisting of: hydrochloric acid, nitric acid, acetic acid, phosphoric acid, polyphosphoric acid, perchloric acid, and combinations thereof.
5. The composition of claim 1 comprising:
about 10 to about 100 parts by volume suspension concentrate comprising
about 20 to about 50 parts by weight glyphosate acid,
about 5 to about 30 total parts by weight of one or more of surfactant, thickener, antifreeze, and antifoam,
about 20 to about 60 parts by weight water; and
about 1 to about 4 parts by volume aqueous acidifying agent.
6. A method of applying a herbicide application composition, the method comprising
preparing a herbicide application composition comprising
a suspension concentrate comprising glyphosate acid,
acidifying agent in an amount so the pH of the herbicide application composition is below the pKa of glyphosate acid, and
applying the herbicide application composition to control plant growth.
7. The method of claim 6 wherein the suspension concentrate comprises from about 25 to about 50 parts by weight glyphosate acid.
8. The method of claim 6 wherein the suspension concentrate comprises glyphosate acid particles suspended in water and surfactant.
9. The method of claim 8 wherein the glyphosate acid particles have an average particle size below about 10 micron.
10. The method of claim 6 wherein the suspension concentrate comprises cationic ethoxylated tallow amine surfactant.
11. The method of claim 6 wherein the pH of the herbicide application composition is below about 2.6.
12. The method of claim 6 wherein the acidifying agent is selected from the group consisting of: hydrochloric acid, nitric acid, acetic acid, phosphoric acid, polyphosphoric acid, perchloric acid, and combinations thereof.
13. A method of preparing a suspension concentrate comprising glyphosate acid, the method comprising:
combining glyphosate acid particles with water, surfactant, and dispersant,
wet milling the mixture of glyphosate acid particles, water, surfactant, and dispersant to reduce the size of glyphosate acid particles to a size that can be suspended in the water, surfactant, and dispersant, and
using a high speed mixer to mix the water, glyphosate acid particles, surfactant, and dispersant, to produce a suspension concentrate comprising the glyphosate acid particles.
14. The method of claim 13 wherein the glyphosate acid particles are wet milled to an average particle diameter less than 10 microns.
15. The method of claim 13 further comprising adding a thickener to the suspension concentrate comprising the glyphosate acid particles, and mixing.
16. A method of preparing a herbicide application composition comprising glyphosate acid, the method comprising
preparing a suspension concentrate composition by a method comprising
combining glyphosate acid particles with water and one or more of surfactant and dispersant, and
mixing or agitating the water, glyphosate acid particles, and one or more of surfactant and dispersant, to produce a suspension concentrate containing the glyphosate acid particles, and
adding acidifying agent in an amount so the pH of the herbicide application composition is below the pKa of glyphosate acid.
17. The herbicide application composition of claim 1 wherein the acidifying agent comprises a sulfuric acid adduct according to the formula:
wherein X is chalcogen, and each of R 1 , R 2 and R 3 is independently selected from hydrogen and organic radicals.
18. The composition of claim 1 wherein the acidifying agent is an adduct of sulfuric acid and urea.
19. The composition of claim 1 wherein the acidifying agent comprises sulfuric acid.
20. The composition of claim 1 comprising
suspension concentrate comprising glyphosate acid,
acidifying agent in an amount so the pH of the herbicide application composition is below the pKa of glyphosate acid, and
water.
21. The composition of claim 20 wherein the ratio of suspension concentrate to water is in the range from 1 pint of suspension concentration: 3 gallons of water to 1 pint of suspension concentrate: 15 gallons of water.
22. The method of claim 6 wherein the acidifying agent comprises sulfuric acid.
23. The method of claim 6 wherein the herbicide application composition comprises
suspension concentrate comprising glyphosate acid,
acidifying agent in an amount so the pH of the herbicide application composition is below the pKa of glyphosate acid, and
water.
24. The method of claim 23 wherein the ratio of suspension concentrate to water is in the range from 1 pint of suspension concentration: 3 gallons of water to 1 pint of suspension concentrate: 15 gallons of water.
25. The method of claim 16 wherein the acidifying agent comprises sulfuric acid.
26. The method of claim 16 comprising a step of diluting the suspension concentrate with water to provide the herbicide application composition.
27. The method of claim 26 wherein the ratio of suspension concentrate to water is in the range from 1 pint of suspension concentration: 3 gallons of water to 1 pint of suspension concentrate: 15 gallons of water.
28. The method of claim 16 wherein the acidifying agent is added to the suspension concentrate in an amount so the pH of the herbicide application composition is below the pKa of glyphosate acid.