Vinyl Ester Dispersion Stabilized Oil and Polymer Adjuvants for Drift Reduction

Vinyl ester dispersions provide a convenient way of formulating drift-reducing adjuvants with the minimal use of emulsifiers. These waterborne dispersions enable the formulator to combine oils and polymers in a single adjuvant package, making them versatile for use in a variety of herbicide and nozzle combinations. This new class of adjuvants shows excellent drift reduction that is largely independent of use rate and shows wetting and deposition characteristics on par with conventional surfactant-based oil-in-water emulsions. Vinyl ester-based oil dispersions can be formulated to lower the extensional viscosity of high molecular weight linear polymers, improving their ease of use without reducing their effectiveness in reducing drift. By varying the hydrophobicity and incorporating specific functional groups, highly stable premix concentrates can be made with water conditioners such as ammonium sulfate and trisodium citrate. These premixes have high shear stability and have shown excellent drift reduction in both ground and aerial spray applications.