STABILIZATION OF DIMPROPYRIDAZ SUSPENSIONS BY TRIETHYLAMMONIUM CHLORIDE

Abstract

The invention relates to an aqueous pesticidal composition comprising a) suspended particles comprising dimpropyridaz, and b) triethylammonium chloride. It also relates to a method for producing the pesticidal composition; to a method for treating plant propagation material; to the use of triethylammonium chloride for inhibiting the crystal growth of particles of dimpropyridaz that are suspended in an pesticidal composition; a method for treating or protecting an animal from infestation or infection by invertebrate pests which comprises bringing the animal in contact with a pesticidally effective amount of the pesticidal composition; to a method for combating or controlling invertebrate pests, which method comprises contacting said pest or its food supply, habitat or breeding grounds with a pesticidally effective amount of the pesticidal composition; and to a method for protecting growing plants from attack or infestation by invertebrate pests, which method comprises contacting a plant, or soil or water in which the plant is growing, with a pesticidally effective amount of the pesticidal composition.

Claims

1. An aqueous pesticidal composition comprising a) suspended particles comprising dimpropyridaz; and b) triethylammonium chloride; wherein a concentration of the triethylammonium chloride is at least 0.3 wt % based on the total weight of the pesticidal composition.

2. The pesticidal composition according to claim 1, wherein the suspended particles a) have a D50-value of from 1 to 5 μm.

3. The pesticidal composition according to claim 1, wherein the concentration of the triethylammonium chloride is up to 2 wt %.

4. The pesticidal composition according to claim 1, wherein the suspended particles are suspended crystalline particles.

5. The pesticidal composition according to claim 1, wherein a weight ratio of the suspended particles a) to the triethylammonium chloride is at up to 70:1.

6. The pesticidal composition according to claim 1 comprising a) 40 to 95 wt % of water b) 5 to 40 wt % of the suspended particles; c) 0.3 to 2 wt % of triethylammonium chloride; each based on the total weight of the pesticidal composition.

7. The pesticidal composition according to claim 1, wherein the triethylammonium chloride is present in dissolved form.

8. The pesticidal composition according to claims 1 comprising a further pesticidally active ingredient.

9. A process for producing a pesticidal composition as defined in claim 1, comprising the step of contacting triethylammonium chloride, particles comprising dimpropyridaz, and water.

10. A method for inhibiting the crystal growth of particles of dimpropyridaz that are suspended in an aqueous pesticidal composition comprising the use of triethylammonium chloride.

11. A method of treating a plant propagation material comprising contacting the plant propagation material with the pesticidal composition as defined in claim 1.

12. A method for treating or protecting an animal from infestation or infection by invertebrate pests comprising bringing the animal in contact with a pesticidally effective amount of the pesticidal composition as defined in claim 1.

13. A method for combating or controlling invertebrate pests, comprising contacting said pest or its food supply, habitat or breeding grounds with a pesticidally effective amount of the pesticidal composition as defined in claim 1.

14. A method for protecting growing plants from attack or infestation by invertebrate pests, comprising contacting a plant, or soil or water in which the plant is growing, with a pesticidally effective amount of the pesticidal composition as defined in claim 1.

Description

EXAMPLES

[0084] The following ingredients were used for preparing the pesticidal compositions of the examples. Insecticide A: 1-[(1RS)-1,2-dimethylpropyl]-N-ethyl-5-methyl-N-pyridazin-4-yl-1H-pyrazole-4-carboxamide.

[0085] Weting Agent: ethoxylated castor oil, 40 polymerized ethylene oxide units per molecule on average, saponification value 58-66 (according to ISO 3657)

[0086] Polymeric Additive: sulfomethylated lignosulfonate, organic sulfur content approximately 9 wt %, mass average molecular weight 20 to 50 kDa

[0087] Antifoam: emulsion of dimethylsiloxan on silica particles, defoamer content 20 wt %

[0088] Biocide A: glycol based solution of benzisothiazolinone

[0089] Biocide B: aqueous composition of benzisothiazolinones and 5-chloro-2-methylisothiazolin one

[0090] Additive A: hydrophobic fumed silica, surface modified with dimethyldichlorosilane, surface area 130 m.sup.2/g

[0091] Stabilizer A: polyarylphenylether sulfate, ammonium salt, viscous liquid at 20° C.

Example-1: Preparation of Suspension Concentrates

[0092] Suspension concentrate were prepared containing the ingredients according to Table A. The suspension concentrates differed by the type and concentration of Stabilizer used. For each type of Stabilizer, suspension concentrates with 0.0 wt %, 0.1 wt %, 0.2 wt %, 0.4 wt %, 0.6 wt %, 0.8 wt % and 1 wt % of the respective Stabilizer were produced. Tested Stabilizers were triethylammonium chloride, sodium chloride, ammonium chloride, ammonium sulfate, tri-ethylammonium bromide, Stabilizer A, and tetraethylammonium iodide.

[0093] In a first step, a premix containing 3 wt % of Xanthan Gum was made by adding Xanthan Gum, part of Biocide A and Biocide B to water. The premix was mixed with a cowles blade until the Xanthan Gum was fully hydrated and the premix was homogenous.

[0094] In a second step, Stabilizer solutions containing 10 wt % of a given Stabilizer as listed in Table B were prepared by diluting the respective Stabilizer in water with agitation.

[0095] In a third step, a millbase was prepared by adding Insecticide A, 50% of the allotted Wetting Agent, Polymeric Additive, Antifoam, the remaining Biocide A, the remaining Biocide B, acetic acid, and Additive A to the remaining water. The mixture was homogenized until uniform and then milled in a bead mill until a mean particle size of 2-3 microns was achieved.

[0096] After the millbase reached particle size, it was mixed with the remaining Wetting Agent, and the premix to yield the final suspension concentrates.

[0097] After the final suspension concentrate had been prepared, the volume of the suspension concentrate was split into several subsamples and the respective Stabilizer solution and water were added and mixed until homogeneous.

TABLE-US-00001 TABLE A Ingredients of suspension concentrates SC-1, and SC-C1, SC-C2, SC-C3, SC-C4, SC-C5, and SC-C6. Component Concentration [wt %] Insecticide A 20.91 Wetting Agent 8.00 Polymeric Additive 2.00 Antifoam 0.40 Biocide A 0.20 Biocide B 0.10 Xanthan Gum 0.13 Acetic acid 0.10 Additive A 1.00 Stabilizer As listed in Table B Water to 100

Example-2: Stability Assessment

[0098] All suspension concentrates as prepared in Example-1 were placed in a −10° C. / 30° C. cycling chamber (temperature cycled at every 24 hours). After 8 or 16 weeks storage, samples were evaluated under microscope for crystal growth. The results are summarized in Table B:

TABLE-US-00002 TABLE B Summary of stability assessment for suspension concentrates that contain different stabilizers at various concentrations. Time in Microscope Observations cycling Stabilizer concentration in suspension concentrates [wt %] Stabilizer chamber 0.00% 0.10% 0.20% 0.40% 0.60% 0.80% 1.00% Triethyl- 16 Crystal Crystal Crystal No No No No ammonium weeks growth Growth Growth Crystal Crystal Crystal Crystal chloride Growth Growth Growth Growth Sodium 8 Crystal Crystal Crystal Crystal Crystal Crystal Crystal chloride weeks Growth Growth Growth Growth Growth Growth Growth Ammonium 8 Crystal Crystal Crystal Crystal Crystal Crystal Crystal chloride weeks Growth Growth Growth Growth Growth Growth Growth Ammonium 8 Crystal Crystal Crystal Crystal Crystal Crystal Crystal sulfate weeks Growth Growth Growth Growth Growth Growth Growth Triethyl- 8 Crystal Crystal Crystal Crystal Crystal Crystal Crystal ammonium weeks Growth Growth Growth Growth Growth Growth Growth bromide Stabilizer 8 Crystal Crystal Crystal Crystal Crystal Crystal Crystal A weeks Growth Growth Growth Growth Growth Growth Growth Tetraethyl- 8 Crystal Crystal Crystal Crystal Crystal Crystal Crystal ammonium weeks Growth Growth Growth Growth Growth Growth Growth iodide