STABILIZATION OF SUSPENSION CONCENTRATES BY HIGHLY SULFONATED LIGNOSULFONATE

Abstract

The invention relates to an aqueous agrochemical composition comprising a) suspended particles of an active ingredient; and b) lignosulfonate. It also relates to use of the lignosulfonate for stabilizing an aqueous agrochemical composition comprising suspended particles of the active ingredient. Further objects are a method of stabilizing an aqueous agrochemical composition comprising suspended particles of an active ingredient; a method for treating, controlling pre-venting or protecting animals against infestation or infection by parasites; a method for the preparation of the agrochemical composition; and plant propagation material comprising the agrochemical composition.

Claims

1. An aqueous agrochemical composition comprising a) suspended particles of dimpropyridaz; and b) lignosulfonate.

2. The agrochemical composition of claim 1, wherein the lignosulfonate has an organic sulfur content of at least 5 wt % based on the total weight of the lignosulfonate.

3. The agrochemical composition of claim 1, wherein the lignosulfonate has an organic sulfur content of at least 8 wt % based on the total weight of the lignosulfonate.

4. The agrochemical composition according to claim 1, containing the lignosulfonate in a concentration of from 0.5 to 10 wt % based on the total weight of the agrochemical composition.

5. The agrochemical composition according to claim 1, containing the lignosulfonate in a concentration of at least 1 wt % based on the total weight of the agrochemical composition.

6. The agrochemical composition according to claim 1, wherein a weight ratio of dimpropyridaz to the lignosulfonate is from 1:1 to 50:1.

7. The agrochemical composition according to claim 1, wherein the suspended particles of dimpropyridaz have a mean diameter of from 0.5 μm to 20 μm.

8. The agrochemical composition according to claim 1, wherein a concentration of the suspended particles of dimpropyridaz in the agrochemical composition is at least 5 wt %.

9. The agrochemical composition according to claim 1, containing a second active ingredient selected from fungicides, insecticides, and herbicides.

10. (canceled)

11. A method of stabilizing an aqueous agrochemical composition comprising suspended particles of dimpropyridaz comprising contacting a lignosulfonate with particles of dimpropyridaz and water.

12. A method for treating, controlling, preventing or protecting animals against infestation or infection by parasites by administering or applying orally, topically or parenterally to the animals the agrochemical composition as defined in claim 1.

13. A method for the preparation of the agrochemical composition as defined in claim 1 comprising contacting a lignosulfonate with dimpropyridaz in the presence of water.

14. A plant propagation material comprising the agrochemical composition as defined in claim 1

Description

EXAMPLES

[1203] The following ingredients were used for preparing the agrochemical compositions of the examples.

[1204] Insecticide A: 1-[(1RS)-1,2-dimethylpropyl]-N-ethyl-5-methyl-N-pyridazin-4-yl-1H-pyrazole-4-carboxamide.

[1205] Polymeric Stabilizer A: sulfomethylated lignosulfonate, organic sulfur content approximately 9 wt %, mass average molecular weight 20 to 50 kDa Polymeric Stabilizer B: polyoxypropylene-polyoxyethylene block copolymer, liquid at 20° C., dynamic viscosity 750 mPas at 25° C., average molecular weight 6500 Polymeric Stabilizer C: nonionic ethoxylated and propoxylated butyl alcohol, HLB 17, solid at 25° C.

[1206] Polymeric Stabilizer D: reaction product of methyl methacrylate, methacrylic acid and methoxy polyethylene glycol methacrylate, dynamic viscosity at 25° C. 800 to 2000 mPas

[1207] Wetting Agent: mixture of sulfated alkylcarboxylate with sulfonated alkylnaphthalene sodium salt

[1208] Antifoam: emulsion of dimethylsiloxan on silica particles, defoamer content 20 wt %

[1209] Biocide A: glycol based solution of benzisothiazolinone

[1210] Biocide B: aqueous composition of benzisothiazolinones and 5-chloro-2-methylisothiazolin-3-one

[1211] Thickener: magnesium aluminium silicate, smectite

[1212] Additive A: hydrophobic fumed silica, surface modified with dimethyldichlorosilane, surface area 130 m.sup.2/g

Example—1

[1213] Suspension concentrate SC-1 and comparative suspension concentrates SC-C1, SC-C2, and SC-C3 were prepared containing the ingredients according to Table A. The suspension concentrates differed by the type of Polymeric Stabilizer used, as provided in Table B.

[1214] The suspension concentrates were prepared by adding in a first step Insecticide A, Wetting Agent, Biocide A, Biocide B, Thickener, Acetic Acid, Antifoam, and Additive A to water.

[1215] The resulting mill base was homogenized in a second step until uniform, and then milled in a bead mill until a mean particle size of 2-3 microns was achieved.

TABLE-US-00001 TABLE A Ingredients of suspension concentrates SC-1, SC-C1, SC-C2, and SC-C3 Concentration Component [wt %] Insecticide A 31.88 Wetting Agent 4.50 Polymeric Stabilizer 3.00 Antifoam 0.40 Biocide A 0.20 Biocide B 0.10 Thickener 0.25 Acetic acid 0.22 Additive A 1.00 Water to 100

TABLE-US-00002 TABLE B Polymeric Thickeners contained in suspension concentrates SC-1, SC-C1, SC-C2, SC-C3; and results of stability analysis after incubation in the cycling chamber. Stability Analyses after incubation in the cycling chamber Incubation two Incubation four Suspension weeks 20° C./ weeks −10° C./ Concentrate Polymeric Stabilizer 40° C. cycling 30° C. cycling SC-1 Polymeric Thickener Flowable No crystal growth A (less than 7 μm) SC-C1 Polymeric Thickener Gelled Significant crystal B growth (up to 23 μm) SC-C2 Polymeric Thickener Gelled Significant crystal C growth (up to 16 μm) SC-C3 Polymeric Thickener Gelled Significant crystal D growth (up to 27 μm)

[1216] The suspension concentrates were then placed in either a 20° C./40° C. cycling chamber (24 hours at 20° C. and 24 hours at 40° C.) for two weeks, or placed in a −10° C./30° C. cycling chamber (24 hours at −10° C. and 24 hours at 40° C.) for four weeks, upon which the suspension concentrates were analyzed by visual inspection and testing of its rheological profile, and by measuring the crystal growth of particles under a microscope. The results were summarized in Table B.

Example—2

[1217] Suspension concentrates SC-2 to SC-6, and comparative suspension concentrate SC-C4, were prepared containing the ingredients according to Table C. The suspension concentrates differed by the amount of Polymeric Stabilizer A used, as provided in Table D.

[1218] The suspension concentrates were prepared by adding in a first step Insecticide A, Wetting Agent, Biocide A, Biocide B, Thickener, Acetic Acid, Antifoam, and Additive A to water.

[1219] The resulting mill base was homogenized in a second step until uniform, and then milled in a bead mill until a mean particle size of 2-3 microns was achieved.

[1220] The suspension concentrates were then placed in either a 20° C./40° C. cycling chamber (24 hours at 20° C. and 24 hours at 40° C.) for two weeks, or placed in a −10° C./30° C. cycling chamber (24 hours at −10° C. and 24 hours at 40° C.) for four weeks, upon which the suspension concentrates were analyzed by visual inspection and testing of its rheological profile, and by measuring the crystal growth of particles under a microscope. The results were summarized in Table D.

TABLE-US-00003 TABLE C Ingredients of suspension concentrates SC-2, to SC-6, and SC-C4. Concentration Component [wt %] Insecticide A 31.88 Wetting Agent 4.50 Polymeric Stabilizer A see Table D Antifoam 0.40 Biocide A 0.20 Biocide B 0.10 Thickener 0.25 Acetic acid 0.22 Additive A 1.00 Water to 100

TABLE-US-00004 TABLE D Concentration of Polymeric Stabilizer A in SC-C4, and SC-2 to SC-4, as well as ob- servations on rheological properties and crystal growth under different cycling conditions. Stability Analyses Stability Analyses after after incubation for Concentration of incubation for three two weeks in the 20° C./ Suspension Polymeric Stabi- weeks in the −10° C./ 40° C. cycling Concentrate lizer A in wt % 30° C. cycling chamber chamber SC-C4 0.0 Very significant crystal Gelled growht SC-2 1.0 Significant crystal growth Semi-flowable SC-3 2.0 Crystal growth detected Very flowable SC-4 3.0 Minimal crystal growth Very flowable SC-5 4.0 Minimal crystal growth Very flowable SC-6 5.0 No crystal growth Very flowable