POLYMER FORMULATION FOR AGRICHEMICAL USE

Abstract

A composition including a salt of a monocarboxylic acid, and a polyacrylamide polymer that hydrates at a pH of at least approximately 6 in the presence of no more than approximately 40 wt % of the salt of a monocarboxylic acid. The present disclosure also includes a method for producing a homogeneous composition for agrichemical use including the following steps. Obtaining a salt of a monocarboxylic acid. Obtaining a polyacrylamide polymer that hydrolyzes in the presence of no more than 40 wt % (or 30 wt %) of the salt of a monocarboxylic acid at a pH of at least about 6. Combining the polyacrylamide and the monocarboxylic acid salt to produce a homogeneous composition. The polymer of the composition is preferably compatible and stable with formulations of potassium glyphosate and used in a spray mixture. The composition may also contain formulation components such a defoamers, water conditioners, surfactants, biocides, stickers and solvents.

Claims

1. A composition, comprising: a salt of a monocarboxylic acid, and a polyacrylamide polymer that hydrates at a pH of at least approximately 6 in the presence of no more than approximately 40 wt % said salt.

2. A composition of claim 1 where said polymer is compatible and stable with formulations of potassium glyphosate used in a spray mixture.

3. A composition of claim 1 also containing formulation components selected from a group consisting of defoamers, water conditioners, surfactants, biocides, stickers and solvents.

4. The composition of claim 1 wherein the anionic charge of the polyacrylamide polymer is less than approximately 10.

5. The composition of claim 1 wherein the anionic charge of the polyacrylamide polymer is less than approximately 50.

6. The composition of claim 1 wherein the pH is less than approximately 10. The composition of claim 1 wherein the pH is less than approximately 8.

8. The composition of claim 1 wherein the pH is approximately 8.

9. The composition of claim 1 wherein the concentration of said salt of am monocarboxylic acid is no more than approximately 30 wt %.

10. The composition of claim 1 which is adapted so as not to form a gel at temperatures of approximately 4° C. and above.

11. A method of producing a homogeneous composition for agrichemical use, comprising: obtaining a salt of a monocarboxylic acid; obtaining a polyacrylamide polymer that hydrolyzes in the presence of no more than 40wt % of said salt of a monocarboxylic acid at a pH of at least about 6; combining said polyacrylamide and said monocarboxylic acid salt to produce the homogeneous composition.

12. The method of claim 11 including adding said composition to formulations of potassium glyphosate for use in a spray mixture.

13. The method of claim 11 including adding one or more of a group consisting of defoamer, water conditioner, surfactant, biocide, sticker, solvent or a combination thereof.

14. The method of claim 11 wherein the anionic charge of the polyacrylamide polymer is less than approximately 10.

15. The composition of claim 11 wherein the anionic charge of the polyacrylamide polymer is less than approximately 50.

16. The composition of claim 11 wherein the pH is less than or equal to approximately 8.

17. The method of claim 11 including adding the homogeneous composition to a pesticide spray mixture to reduce driftable fine particles.

18. The method of claim 11 including adding the homogeneous composition to a pesticide spray mixture including auxinic herbicide in order to reduce volatility of said auxinic herbicide.

19. The method of claim 11 including adding the homogeneous composition to a spray mixture containing dicamba.

20. The method of claim 12 including the further step of adding the composition to tank mixtures containing isopropyl ammonium, monoethanolamine, diethanolamine and dimethylamne salts of glyphosate.

Description

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processes and manufacturing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the invention herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the claimed invention.

[0021] The current invention is a homogeneous single phase of a polymer combined with a salt of a monocarboxylic acid, thereby combining the feature of drift control and vapor reduction of a pesticide spray.

[0022] The polymer for this combination must have low to very low anionic charge density, less than 50, less than 40, less than 30, less than 20 preferably less than 15% and even more preferred under 10%. Low anionic charge polymers are often referred to as “nonionic”

[0023] In practice polyacrylamides are supplied by the manufacturer as a dry, free flowing powder. In one method of this invention, the polyacrylamide powder is hydrated in water to which the salt of the monocarboxylic acid is added during or after hydration but most preferably during hydration. In a second method a dry formulation of polyacrylamide powder and dry salt of monocarboxylic acid are blended together for use by addition to water in a spray tank.

[0024] The salt of the monocarboxylic acid also has an impact on the polymer. Potassium salts reduce the speed of hydration of all types of polyacrylamides (independent of anionic charge) in a concentration dependent manner.

[0025] Example 1: Effect of potassium acetate concentration on polymer hydration.

[0026] Two separate polymers were tested for hydration in various wt percentages of an exemplary salt of a monocarboxylic acid. For these examples, potassium acetate was selected at three different concentrations, 30%, 40%, and 50%. These concentrations can be achieved by dilution of potassium acetate powder in water to the target concentration, however, for the present examples, a commercially available 50% potassium acetate solution was obtained which was diluted with water to adjust to the other target concentrations (40% and 30%). A 0% (water only) control was also employed.

[0027] Two exemplary commercially available polymers were selected for these examples, Pamamer 29 and Magnafloc 351. The polymers were tested separately with each different potassium acetate concentration and the control. In these examples, Pamamer 29 (1.3%) and Magnafloc 351 (1.1%) were added separately to each separate concentration of potassium acetate at room temperature (approximately 20° C. to 25° C.). For this example, the pH was adjusted to approximately 8, if necessary, by addition of a 50% citric acid solution.

[0028] Each separate combination was mixed using a Cowles disperser/dissolver/dispersater for a minimum of eight (8) hours. Following mixing, hydration was observed visually where a clear solution indicated hydration and a suspension of polymer (visually observable fish eyes) indicated a lack of hydration. Both polymers hydrated in the control. The observed effect of potassium acetate concentration on polymer hydration is set forth in Table 1. It is apparent that both polymers will hydrate at concentrations of salt of monocarboxylic acid of less than about 40% and particularly at any concentration less than or equal to about 30%.

TABLE-US-00001 TABLE 1 Effect of potassium acetate concentration on polymer hydration Compatibility Hydration Hydration Hydration with in 50% in 40% in 30% Mol potassium potassium potassium potassium Polymer Charge weight glyphosate acetate acetate acetate Pamamer 29 Nonionic Low Compatible No Slightly Yes Magnafloc 351 Nonionic high Compatible No No Yes

[0029] Example 2: Effect of pH on polymer stability in solution at low temperatures in 30% potassium acetate

[0030] Temperature and pH of the polymer can also affect both hydration and physical stability of the resulting solution.

[0031] For these examples, the two polymers were tested separately with a potassium acetate concentration of approximately 30%. In these examples, Pamamer 29 (1.3%) and Magnafloc 351 (1.1%) were each added to two separate 30% solutions of potassium acetate at room temperature (approximately 20° C. to 25° C.). The pH of one pair of polymer/salt solutions was adjusted to approximately 6 and the pH of the second pair of polymer/salt solutions was adjusted to approximately 8 by addition of a 50% citric acid solution.

[0032] Each separate combinations were mixed using a Cowles disperser/dissolver/dispersater for a minimum of eight (8) hours. Following mixing, hydration was observed visually where a clear solution indicated hydration and a suspension of polymer (visually observable fish eyes) indicated a lack of hydration. Each separate combination which exhibited hydration was then refrigerated to approximately 4° C. for thirty (30) days. After thirty days the temperature response was visually observed. A negative temperature response was indicated by the presence of gelling of the solution while a positive temperature response was indicated by a clear solution with a lack of or very little gel formation. The effect of pH on polymer stability in solution at low temperatures in 30% salt of monocarboxylic acid is indicated in Table 2.

TABLE-US-00002 TABLE 2 Effect of pH on polymer stability in solution at low temperatures in 30% potassium acetate Mol Temperature Temperature Polymer Charge weight pH Response pH response Pamamer 29 nonionic low 6 - hydrates 4 C. no gel 8 - hydrates 4 C. gels Magnafloc 351 nonionic high 6 - will not — 8 -hydrates 4 C. gels hydrate

[0033] The current disclosure provides a composition and method to produce stable homogeneous combinations of a nonionic (eg very low anionic charge) polyacrylamide and a salt of a monocarboxylic acid that are compatible with commonly used combinations of an auxin herbicide and/or potassium glyphosate, and effectively reduce driftable fines while suppressing volatility for auxin herbicides.

[0034] It is to be understood that the terms “including”, “comprising”, “consisting” and grammatical variants thereof do not preclude the addition of one or more components, features, steps, or integers or groups thereof and that the terms are to be construed as specifying components, features, steps or integers.

[0035] If the specification or claims refer to “an additional” element, that does not preclude there being more than one of the additional element.

[0036] It is to be understood that where the claims or specification refer to “a” or “an” element, such reference is not be construed that there is only one of that element.

[0037] It is to be understood that where the specification states that a component, feature, structure, or characteristic “may”, “might”, “can” or “could” be included, that particular component, feature, structure, or characteristic is not required to be included.

[0038] Where applicable, although state diagrams, flow diagrams or both may be used to describe embodiments, the invention is not limited to those diagrams or to the corresponding descriptions. For example, flow need not move through each illustrated box or state, or in exactly the same order as illustrated and described.

[0039] Methods of the present invention may be implemented by performing or completing manually, automatically, or a combination thereof, selected steps or tasks.

[0040] The term “method” may refer to manners, means, techniques and procedures for accomplishing a given task including, but not limited to, those manners, means, techniques and procedures either known to, or readily developed from known manners, means, techniques and procedures by practitioners of the art to which the invention belongs.

[0041] The term “at least” followed by a number is used herein to denote the start of a range beginning with that number (which may be a ranger having an upper limit or no upper limit, depending on the variable being defined). For example, “at least 1” means 1 or more than 1. The term “at most” followed by a number is used herein to denote the end of a range ending with that number (which may be a range having 1 or 0 as its lower limit, or a range having no lower limit, depending upon the variable being defined). For example, “at most 4” means 4 or less than 4, and “at most 40%” means 40% or less than 40%. Terms of approximation (e.g., “about”, “substantially”, “approximately”, etc.) should be interpreted according to their ordinary and customary meanings as used in the associated art unless indicated otherwise. Absent a specific definition and absent ordinary and customary usage in the associated art, such terms should be interpreted to be ±10% of the base value.

[0042] When, in this document, a range is given as “(a first number) to (a second number)” or “(a first number)-(a second number)”, this means a range whose lower limit is the first number and whose upper limit is the second number. For example, 25 to 100 should be interpreted to mean a range whose lower limit is 25 and whose upper limit is 100. Additionally, it should be noted that where a range is given, every possible subrange or interval within that range is also specifically intended unless the context indicates to the contrary. For example, if the specification indicates a range of 25 to 100 such range is also intended to include subranges such as 26-100, 27-100, etc., 25-99, 25-98, etc., as well as any other possible combination of lower and upper values within the stated range, e.g., 33-47, 60-97, 41-45, 28-96, etc. Note that integer range values have been used in this paragraph for purposes of illustration only and decimal and fractional values (e.g., 46.7-91.3) should also be understood to be intended as possible subrange endpoints unless specifically excluded.

[0043] It should be noted that where reference is made herein to a method comprising two or more defined steps, the defined steps can be carried out in any order or simultaneously (except where context excludes that possibility), and the method can also include one or more other steps which are carried out before any of the defined steps, between two of the defined steps, or after all of the defined steps (except where context excludes that possibility).

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[0044] Thus, the present invention is well adapted to carry out the objects and attain the ends and advantages mentioned above as well as those inherent therein. While presently preferred embodiments have been described for purposes of this disclosure, numerous changes and modifications will be apparent to those skilled in the art. Such changes and modifications are encompassed within the spirit of this invention as defined by the appended claims.