Patent Application
20110118121
The invention generally relates to novel solvents for 2,4-D acid and plant growth regulating acids and to methods for preparing formulations containing them.
Many agricultural formulations contain actives such as herbicide or plant growth regulators (PGR's) in their acid form. The solubility of these acids is normally very low in both polar and non-polar solvents. Typically, in order to more easily solubilize these actives, they are conversed into their ester or salt form by further chemical reaction. However these added steps increase formulation costs and acid loading in the final formulations is typically lowed.
Another common way is to dissolve these actives at low level in alcohol. Isopropanol is commonly used as the solvent. The disadvantage of this approach is that the resulting formulation is highly flammable, creating storage and safety issues for users.
2,4-dichlorophenoxyacetic acid (2,4-D) and its non-amine salts have very low solubility in water. Because of this, the most commonly used 2,4-D herbicide is 2,4-D amine salts. Although hydrophobic 2,4-D esters are available, 2,4-D formulated and applied as a water-soluble salt has the added advantages of not requiring an emulsifier and/or an organic solvent.
Accordingly, it is an object of the invention to provide a formulation of 2,4-D acid or the acid of plant growth regulators in a non-flammable formulation, which is stable and cost effective.
The present inventors have surprisingly discovered that 2,4-D acid and many plant growth regulating acids can be dissolved very effectively in a certain class of surfactants. More specifically, it has been surprisingly discovered that certain surfactants, i.e., alkoxylated quaternary surfactants and alkyl quaternary surfactants are extremely effective and useful in solubilizing 2,4-D acid or acid plant growth regulators. Additionally, the surfactants of the invention improve formulation cost, allow high acid loading and improve storage stability, and the formulations no longer flammable, in that they have flash points over 200° F.
In one embodiment, the invention contemplates a formulation comprising at least one of 2,4-D acid or acid plant growth regulator and at least one alkoxylated quaternary surfactant, or alkyl quaternary surfactants surfactant in an effective amount such that said acid is dissolved in the surfactant and said at least one surfactant is present in a quantity 10 to 70% in the composition.
The invention also relates to a process for preparing a composition which comprises 2,4-D acid or acid plant growth regulator solubilized with the surfactants contemplated herein, and to a method for solubilizing same.
The present generally relates to a method of solubilizing 2,4-D acid and/or plant growth regulating acids with certain alkoxylated quaternary surfactants and/or alkyl quaternary surfactants. The invention also relates to agricultural formulations comprising 2,4-D and or plant growth regulating acids solubilized with certain alkoxylated quaternary surfactants and/or alkyl quaternary surfactants of the invention. These surfactants are surprisingly effective and useful in solubilizing 2,4-D acid and/or acid plant growth regulators, while at the same time improving formulation cost and storage stability and allowing high acid loading. The flash points of the formulations are over 200° F., which is also a dramatic improvement in flammability.
Acid plant growth regulators that are relatively insoluble in water, but can be readily solubilized by the surfactants of the invention include, but are not limited by: Synthetic auxins including, but not limited to Indole acetic acids, Indole butyric acids, Giberrelic acids, Naphthalene acetic acids, Cytokinins, Abscisic acid and the like.
The surfactants of the invention that have been found to be particularly useful include alkoxylated quaternary surfactants and alkyl quaternary surfactants. The alkoxylated quaternary surfactants that are useful in the context of the present invention are represented by the formula:
wherein R1 is a straight or branched chain, saturated or unsaturated alkyl group having from 8 to 22 carbon atoms; R2 is a hydrogen and/or a straight or branched chain alkyl group having from 1 to 4 carbon atoms; A is CxH2x where x is 2 to 4; B is CyH2y where y is 2 to 6; X− is a compatible anion such as methyl sulfate or chloride, f is zero to 10; m and n is an integer of from 0-30 with the proviso that m+n is at least 1, p is 1 to 7 and g can be any number from zero to 6 for each p and independent of p, and q is 1 to 7 with a provision that p may be greater than q. In one embodiment, the A is C2H4, f=0, and g=0. In another embodiment, the A is C2H4, f=0, g=0, m+n is 1 to 20, R2 is methyl group, p=1, q=1, and X is chloride.
Alkoxylated quaternary surfactants having utility in the context of the invention include, but are not limited to:
The following alkyl quaternary surfactants are useful in the context of the present invention:
wherein R1 is a straight or branched chain, saturated or unsaturated alkyl group having from 8 to 22 carbon atoms. R2 is a hydrogen and/or a straight or branched chain alkyl group having from 1 to 4 carbon atoms, R3 and R4 is independently a straight or branched chain alkyl group having from 1 to 4 carbon atoms, A is CxH2x where x is 2 to 4; B is CyH2y where y is 2 to 6; and X− is a compatible anion such as methyl sulfate or chloride. f is zero to 10; p is 1 to 7 and g can be any number from zero to 6 for each p and independent of p, and q is 1 to 7 with a provision that p may be greater than q. In one embodiment, the A is C2H4, f=0, and g=0. In another embodiment, the A is C2H4, f=0, g=0, R2 is methyl group, R3 is a methyl group, R4 is a methyl group, p=1, q=1, and X is chloride.
Alkyl quaternary surfactants having utility in the context of the present invention include, but are not limited to:
Typically, the formulations of the invention are formulated such that they comprise at least 2,4-D acid and/or one or more additional acid plant growth regulators and at least one surfactant in accordance with the invention in an effective amount such that said 2,4-D acid and/or acid plant growth regulator is dissolved in the surfactant and said at least one surfactant is present in a quantity 10 to 70 wt. % based on that of the final formulation.
2,4-D is a known herbicide, but at lower concentration rates it can also be used as plant growth regulator. The content of active ingredients might be varied which is depended on the chemical properties of the active ingredients. When the formulation is used as plant growth regulators, it is possible to have a formulation comprising different kinds of growth regulators i.e. 2,4-D acid and another plant regulator. However, when 2,4-d acid is used as a herbicide rather than a grow regulator, the formulation typically will not containing another plant growth regulator.
Plant growth regulating acids include, but are not limited to the acid forms of: synthetic auxins including, but not limited to: indole acetic acids, indole butyric acids, giberrelic acids naphthalene acetic acids, cytokinins, abscisic acid and mixtures and combinations thereof.
The formulations of the invention may also contain certain oil-based components. The oil or oil substitutes include, but are not limited to:
The formulation can contain one or more of the above oils or its equivalent. The oil can also be a blend of at least two oils. When oil is used in the formulation, a surfactant or emulsifier must also be used if the composition is intended for aqueous based sprays.
In one embodiment, the invention relates to an agricultural formulation comprising:
The surfactant(s) of the invention are included in an amount effective to solubilize the 2,4-D acid and/or acid plant growth regulator contained in the formulation. Generally, this amount is from about 8 to about 99%, in another embodiment from about 50 to about 90%, and in another embodiment from about 95 to about 98% by weight based on the total weight of the formulation. Typically, the ratio of 2,4-D acid and/or acid plant growth to surfactant in formulations of the invention is from about 1:6 to about 1:1.
Formulations of the invention containing 2,4-D acid or acid plant growth regulator can optionally contain other solvents such as water and/or one or more aromatic solvents. If additional solvents are included, it is preferred that they be included in amounts of from 0 to 50% by weight, in another embodiment at most 35% by weight and in still another embodiment at most 30% by weight.
The invention will now be illustrated by the following non-limiting examples.
In all of the above examples, the components are blended together and the technical dissolved entirely. The solution formed contains less than 2% of precipitates in the example 2 and in the case of example 1 and 3 which showed 0% precipitates.
One of ordinary skill in the art would recognize that various modifications within the spirit and scope of the invention can be made. For example, one could readily formulate pesticides in accordance with the invention, and fertilizers could be added to the formulations of the invention without deviating from the scope thereof.
All references discussed herein are incorporated by reference in their entirety for all useful purposes.
| Number | Date | Country | Kind |
|---|---|---|---|
| 08163975.9 | Sep 2008 | EP | regional |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP2009/058381 | 7/3/2009 | WO | 00 | 1/6/2011 |
| Number | Date | Country | |
|---|---|---|---|
| 61078912 | Jul 2008 | US |
