EP-3270690-B1 - ADJUVANT COMPOSITION, TREATMENT COMPOSITION AND AQUEOUS SPRAY FORMULATIONS SUITABLE FOR AGRICULTURALLY-RELATED USE

Inventors

• Bonn, Daniel

Dates

Publication Date

20260506

Application Date

20150320

Claims (7)

1. Use of polyethylene oxide having a molecular weight between 5 x 10 5 and 1 x 10 8 g/mole, and a non-ionic surfactant having a HLB value or Hydrophilic-Lipophilic Balance of at least 10, preferably at least 12, in an aqueous spray formulation for agricultural use said formulation comprising: * said polyethylene oxide in an amount of at least 0.005 gram/liter; * said non-ionic surfactant in an amount of at least 0.001 wt.%; * an active ingredient, preferably in an amount of at least 0.05 wt.%; and * water, wherein the active ingredient is selected from the group consisting of a plant growth regulator, a defoliant, a growth stimulator, a nutrient, and a pesticide, said pesticide preferably selected from the group consisting of a herbicide, an insecticide, a fungicide, a nematicide, a molluscicide, and a miticide; wherein said use of said polyethylene oxide and said non-ionic surfactant is for reducing spray drift and increasing the deposition of the active ingredients on plants and/or for increasing the rainfastness of the active ingredient applied to plants, preferably to a value of at least 50%.
2. Use according to claim 1, wherein the concentration of the non-ionic surfactant in the aqueous spray formulation is between 0.001 wt.% and 10.0 wt.%, preferably between 0.01 wt.% and 5 wt.%, more preferably between 0.1 wt.% and 1 wt.%.
3. Use according to claim 1 or 2, wherein the dynamic surface tension of the aqueous spray formulation is at most 50 mN/m after 100 milliseconds (DST 100ms ) and/or wherein the difference between the dynamic surface tension after 1 milliseconds (DST 1ms ) and after 100 milliseconds (DST 100ms ) is at least 15 mN/m, wherein the dynamic surface tension is measured using the maximum bubble pressure (MBP) method.
4. Use according to any one of the preceding claims, wherein the first normal stress coefficient of the aqueous spray formulation is greater than or equal to 10 -8 Pas 2 .
5. Use according to any one of the preceding claims, wherein the viscosity of the aqueous spray formulation is between 1 and 5 mPa.s, preferably at most 3 mPa.s, more preferably at most 2 mPa.s.
6. Use according to any one of the preceding claims, wherein the polyethylene oxide has a molecular weight of at least 1 x 10 6 , preferably at least 2 x 10 6 , more preferably at least 3 x 10 6 .
7. Use according to any one of the preceding claims, wherein the weight ratio between the non-ionic surfactant and the polymer is at least 1:5.

Description

The present invention relates to the use of polyethylene oxide and a non-ionic surfactant in an aqueous spray formulation for agricultural use for reducing spray drift and increasing the deposition of the active ingredients on plants and/or for increasing the rainfastness of the active ingredient applied to plants. In the agricultural industry, plant promoter substances such as nutrients may have to be applied and/or various types of problems or "pests" must be controlled or eliminated to enhance and/or promote growth of the plants in certain area, such as fields of crops, wooded areas, grazing areas for cattle etc.. With "pests" is meant small animals (such as field mice), weeds, insects, foliage, vegetation, etc.. A product must be selected which is effective in stimulating or promoting plant growth and/or controlling or eliminating a specific pest (called plant promoter product in the present invention) and which is usable in the particular area. This plant promoter product usually comprises an active ingredient, water and one or more additives. The product needs to be applied to the (plants on the) area, for example by spraying. The present invention discloses an adjuvant composition that can be used to improve the spraying of such plant promoter products. Such products may include as an active ingredient e.g. a pesticide or an agent for controlling plant growth. Such products are commercially available in the form of a solution, dispersion or emulsion in an aqueous medium. Plant promoter products are usually applied by means of spraying. Aqueous spray formulations have been used for several decades to apply agricultural compounds. By spray deposition the formulation is provided to plant parts, e.g. plant leaves. A spraying operation is generally conducted either from the air - aerial application using e.g. spray planes - or from the ground - ground application using e.g. crop spraying machines - depending on the situation. Ground spraying also includes hand-held refillable pressurized tank sprayers. Conventional equipment is available for either type of application. When spraying these commercial products on plants it is important to ensure good coverage of all plants or plants parts while at the same time preventing loss of product which is economically undesirable. Moreover, pollution of the ground and the surface water should be prevented as well as exposure of people and wildlife, which may cause health and environmental damages. During the spraying of plant protection products (in the form of an aqueous spray formulation further comprising water and optionally one or more additives) several factors play a role, such as the wind blowing away the droplets and the bouncing off the droplets of the plants parts. It is thus challenging to efficiently deposit such plant protection products. Parameters that play a role during agricultural spraying are the size of the droplets in in the spray of the formulation, the droplet size distribution of the spray as well as the interaction of these droplets with the plant parts (e.g. the stems and/or leaves). For efficient deposition, it is important to reduce spray drift, being the blowing away of droplets by the wind. The term "drift" is meant to refer to the tendency of a formulation to travel out of the desired area, in other words the tendency to miss the specific pest within the area. Moreover, it is important to increase the deposition. The term "deposition" is meant to refer to the amount of formulation which contacts and stays into contact with the pest within the desired area. It is on the one hand preferred that the droplet size is small, in order to prevent loss of the active ingredient because of droplets rebounding off the hydrophobic plant leaves. For efficient deposition, it is on the other hand preferred that the droplet size is large, in order to minimize spray drift. The problems of drift and deposition of aqueous spray formulations are encountered by people in agriculturally-related situations, whether farmers working with crops, people working with forests, etc.. Government regulations in many countries require the reduction of drift or require a so-called "crop-free" zone on the sides of the field to prevent drift of the plant protection products onto neighboring areas. There are hence two difficulties to address, the reduction of the drift and the optimization of the deposition. A prior art solution to the deposition problem is to introduce additives in the form of surfactants that greatly reduce the surface tension. These additives are referred to as depositions agents. While the deposition is improved, this increases spray drift which is undesirable. A prior art combined anti-drift and deposition agent is known from European patent application EP 2 732 705 by the present inventor. This patent application describes the use of polyethylene oxide having a molecular weight between 5 x 105 and 1 x 108 g/mole as a combined anti drift and depositi