New Microcapsules Containing Active Substances

Abstract

Microcapsule having a shell and a core, wherein said core contains a non-aqueous liquid, said non-aqueous liquid being one or more liquid (at 21 C.) active substances or one or more active substances dissolved in a solvent S, solvent S being immiscible with water, and wherein said shell contains i) at least one protein PR that is overall negatively charged, ii) at least one polysaccharide PS that is overall positively charged, and iii) optionally an inorganic salt IS capable of crosslinking components protein PR and polysaccharide PS via formation of non-covalent bonds.

Claims

1. A microcapsule having a shell and a core, wherein said core comprises a non-aqueous liquid, said nonaqueous liquid being one or more liquid (at 21 C.) active substance or one or more active substance dissolved in a solvent S, saki solvent S being immiscible with water, and wherein said shell comprises i) at least one protein PR that is overall negatively charged, where said protein PR is a plant protein ii) at least one chitosan, and iii) optionally an inorganic salt IS capable of crosslinking components said at least one protein PR and a polysaccharide PS via formation of non-covalent bonds.

2. The microcapsule according to claim 1, where protein PR and chitosan are not crosslinked with aliphatic aldehydes.

3. The microcapsule according to claim 1, wherein said protein PR is a protein that is overall negatively charged at a pH above 4.

4. The microcapsule according to claim 1, wherein said protein PR is a vegan protein.

5. The microcapsule according to claim 1, wherein said protein PR is selected from the group consisting of pea proteins, rice proteins, wheat proteins, sunflower proteins, and soy proteins.

6. The microcapsule according to claim 1, wherein said protein PR is applied in its naturally occurring form or as a hydrolysate.

7. The microcapsule according to claim 1, wherein said polysaccharide PS contains amino groups.

8. The microcapsule according to claim 1, wherein said chitosan is obtained from a mushroom or a crustacean.

9. The microcapsule according to claim 1, wherein said inorganic salt IS contains at least two charged moieties.

10. The microcapsule according to claim 1, wherein said inorganic salt IS is a polyphosphate.

11. The microcapsule according to claim 1, further comprising a nonionic surfactant.

12. The microcapsule according to claim 1, wherein a mass ratio of the protein PR to the polysaccharide PS is from 1:10 to 10:1.

13. The microcapsule according to claim 1, wherein the microcapsules have an average diameter d50 of 0.1 to 20 m,.

14. The microcapsule according to claim 1, wherein the microcapsules contain microcapsule comprises from 1 to 95 wt % of said one or more active substance.

15. The microcapsule according to claim 1, wherein said one or more active substance is selected from pesticides, synergists, adjuvants, plant health agents, repellants, biocides, phase-change materials, pharmaceuticals, fragrances, perfumes, vitamins, essential oils, plant extracts, nutrients, vegetable oils, marine oils, vitamins, aromas, antioxidants, essential oils, plant extracts, pheromones, and catalysts.

16. A process for making a microcapsule, comprising: A) providing an aqueous solution of at least one protein PR, wherein said protein PR is overall negatively charged in said aqueous solution, and wherein said protein PR is at least partly dissolved in the aqueous solution, B) providing a separate aqueous solution of at least one polysaccharide PS, wherein said polysaccharide PS is overall positively charged and wherein said polysaccharide PS is at least partly dissolved in the aqueous solution, C) emulsifying a liquid active substance or a solution of an active substance in a solvent S, saki solvent S being immiscible with water, in the aqueous solutions provided under step A), optionally supported by stirring and/or a surfactant, D) adding the aqueous solution obtained in step B) to the emulsion obtained in step C). E) optionally adding at least one inorganic salt to the mixture obtained in step D), said inorganic salt IS being capable of crosslinking protein PR and said at least one polysaccharide PS via formation of noncovalent bonds.

17. The process according to claim 15, wherein a pH of the aqueous solution A) is adjusted to a value of 4 or higher before carrying out step D).

18. The process according to claim 15, wherein a pH of the aqueous solution B) is adjusted to a value of 7 or below before carrying out step D).

19. The process according to claim 15, wherein said surfactant used in step C) is a nonionic surfactant.

20. The process according to claim 15, wherein step C) is carried out such that an oil in water emulsion is obtained in step C).

21. The process according to claim 15, wherein said inorganic salt is added in step E) such that said the mixture obtained comprises 0.001 to 5 wt % of said inorganic salt, based on the entire mixture.

22. A formulation comprising microcapsules according to claim 1, wherein said microcapsules are present as dispersed particles in an aqueous medium.

23. The formulation according to claim 22, wherein said formulation comprises 1 to 50 wt % of said one or more active substances substance.

24. (canceled)

25. A method for controlling phytopathogenic fungi and/or undesired plant growth and/or undesired attack by insects or mites and/or for regulating the growth of plants, where microcapsules according to claim 1 comprising one or more pesticide as an active substance, are allowed to contact a particular pest, its habitat or plants to be protected from the particular pest, the soil, and/or undesired plants and/or useful plants and/or their habitat.

26. A seed containing microcapsules according to claim 1.

Description

EXAMPLES

[0542] Particle size Distribution (PSD) was determined by statistic laser scattering using a Malvern Mastersizer 200 according to European norm ISO 13320 EN. The data were treated according to the Mie-Theory by software using a universal model provided by Malvern Instruments. Important parameters are the d o -values for n=10, 50 and 90.

[0543] Materials used

[0544] Protein A: pea protein obtained from Nutralys Pea Protein S85 XF from Roquette (protein content ca 85%, loss on drying ca 10%).

[0545] Protein B: hydrolyzed wheat protein Nutralys W from Roquette (protein content ca 85%, loss on drying ca<8%)

[0546] Protein C: wheat protein having a soluble fraction at 21 C. at a pH of 7 of more than 95 wt % and having a viscosity (Brookfield A1540 method) of 2000-12 000 mPas (Solpro 050 from Syral), protein content ca 82%, loss on drying ca <7%

[0547] Protein D: hydrolyzed rice protein PeptAlde from BASF, protein content >75%

[0548] Polysaccharide A: chitosan having a viscosity <200 mPa.Math.s, 1% in acetic acid (20 C. Brookfield A1540 method), degree of acetylation (Determined by NMR, according to the method described Journal of Pharmaceutical and Biomedical Analysis 32 (2003), 1149-1158 in DOI 10.1016/S0731-7085(03)00155-9): >75% (Chitosan LV from Sigma Aldrich)

TABLE-US-00004 Surfactant A polysorbate ethoxylate lauryl ester Solvent A Methylated soybean oil Solvent B Solvesso 200 ND

Example 1

[0549] Cinmethylin liquid tgai (65.44 g) was emulsified into an aqueous pea protein solution (94.31 water, 3.35 g Protein A, 0.5 g Surfactant A) with an ULTRA-TURRAX 25 for 3 min at 22 500 rpm. A chitosan solution (2.46 g of chitosan in 59.26 g of water) with a pH of 4.65 (adjusted with acetic acid) was added to the emulsion.

[0550] The mixture was stirred for 30 min with a propeller stirrer at 250 rpm.

[0551] Afterwards, sodium hexametaphosphate (0.02 g in 24.94 g of DI water) was added.

[0552] The mixture was stirred for 2 h at room temperature.

[0553] The mean d50 of the capsule suspension obtained was 6.4 pm and the d90 was 29.5 m.

[0554] The so prepared capsules were compared to Emulsifiable Concentrate (EC) and Polyurea Capsules Suspension (PU CS) formulations. They showed excellent efficacies in controlling ALOMY, LOLRI, LOLMU, GALAP weeds but also good crop tolerance on winter wheat and barley, under greenhouse and field conditions. The capsules so prepared showed also much better volatility property than EC, surprisingly very similar to PU CS.

Example 2

[0555] Cinmethylin liquid tgai (400.101 g) was emulsified into 605.87 g of aqueous hydrolyzed wheat protein solution (containing 3.35% w:w of Protein B and 0.5% w:w of surfactant A, pH 5.4) with an ULTRA-TURRAX DF 25 for 3 min at 21 000 rpm.

[0556] 370.82 g of an aqueous chitosan solution (containing 4% w:w of polysaccharide A with a pH 4.65 in (adjusted with acetic acid) was added to the emulsion. Time to add the solution: 20 min

[0557] The mixture was stirred for 30 min with a propeller stirrer at 250 rpm.

[0558] Then, 154 g of an aqueous sodium hexametaphosphate solution (containing 0.1% w/w sodium hexametaphosphate, pH 7.4) was added.

[0559] The mixture was stirred for 1 h 30 at room temperature.

[0560] The pH at the end of the reaction was 4.7.

[0561] The mean d50 of the capsule suspension obtained was 3 m and the d90 was 10 m.

Example 3

[0562] Cinmethylin liquid tgai (400.97 g) was emulsified into 606.18 g of aqueous wheat protein solution (containing 3.40% w:w of Protein C and 0.5% w:w of surfactant A, pH 6.3) with an ULTRATURRAX DF 25 for 3 min at 21 000 rpm.

[0563] 370.30 g of an aqueous chitosan solution (containing 4% w:w of polysaccharide A) at pH 4.65 (adjusted with acetic acid) was added to the emulsion. Time to add the chitosan solution: 20 min

[0564] The mixture was stirred for 30 min with a propeller stirrer at 250 rpm.

[0565] Then, 153 g of an aqueous sodium hexametaphosphate solution (containing 0,1% w:w sodium hexametaphosphate, pH 7.4) was added.

[0566] The mixture was stirred for 1h 30 at room temperature.

[0567] The pH at the end of the reaction was 4 (adjusted with acetic acid)

[0568] The mean d50 of the capsule suspension obtained was 3 m and the d90 was 8 m.

Example 4

[0569] Cinmethylin liquid tgai (161.52 g) was emulsified into 242.86 g of aqueous hydrolyzed rice protein solution (containing 3.40% w:w of Protein D and 0.5% w:w of surfactant A, pH 8.9) with an ULTRA-TURRAX DF 25 for 2 min at 21 000 rpm.

[0570] 148.47 g of an aqueous chitosan solution (containing 4% w:w of polysaccharide A) at pH 4.65 (adjusted with acetic acid) was added to the emulsion. Time to add the chitosan solution: 20 min

[0571] The mixture was stirred for 30 min with a propeller stirrer at 250 rpm.

[0572] Then, 66 g of an aqueous sodium hexametaphosphate solution (containing 0,1% w:w sodium hexametaphosphate, pH 7.4) was added.

[0573] The mixture was stirred for 1 h 30 at room temperature.

[0574] The pH at the end of the reaction was 4 (adjusted with acetic acid)

[0575] The mean d50 of the capsule suspension obtained was 9 m and the d90 was 57 m.

Example 5

[0576] Scale-up for production:

[0577] Cinmethylin liquid (3.9 kg) was continuously emulsified into an aqueous pea protein solution (5.7 kg water, 0.2 kg Protein A, 30 g Surfactant A) with a three stage in-line Rotor-Stator, with the ratios between the active ingredient and other components being as in example 1.

[0578] After emulsification, the Chitosan solution (0.147 kg of Polysaccharide A in 1,5 kg of water) was added continuously into the stirred product vessel from the continuous emulsification. The mixture was stirred for 60 min with an anchor stirrer.

[0579] Sodium hexamethaphosphate (1.2 g solution in 1.5 kg of deionized water) was then added to the mixture and stirred for 2 h.

[0580] The mean d50 of the scale-up capsule suspension obtained is 3.9 m and the d90 is 8.5 m.

Example 6

[0581] Dimethenamid-P liquid tgai (123.97 g), Clomazone viscous liquid tgai (15.50 g) and Solvent B (108.47 g) were mixed and then emulsified into 227.8 g of aqueous wheat protein solution (containing 2.96% w:w of Protein C and 0.44% w:w of surfactant A, pH 6.3) with an ULTRA-TURRAX DF 25 for 3 min at 18 000 rpm.

[0582] 124.23 g of an aqueous chitosan solution (containing 4% w:w of polysaccharide A) at pH 4.65 (adjusted with acetic acid) was added to the emulsion. Time to add the chitosan solution: 45 min

[0583] The mixture was stirred for 60 min with a propeller stirrer at 150 rpm.

[0584] Then, 20.06 g of an aqueous ammonium polyphosphate solution (Exolite AP 420) (containing 0.25% w:w ammonium polyphosphate) was added over 15 minutes.

[0585] The mixture was stirred for 1 h at room temperature.

[0586] The mean d50 of the capsule suspension obtained was 4.5 m and the d90 was 11.6 m.

[0587] The so prepared capsules were compared to a tank-mix of Dimethenamid-P Emulsifiable Concentrate (EC) and Clomazone Polyurea Capsules Suspension (PU CS), as well as to Dimethenamid-P and Clomazone co-Polyurea Capsules Suspension. The capsules example 6 showed excellent efficacies in controlling SETFA, STEME weeds under greenhouse conditions.

Example 7

[0588] Dimethenamid-P liquid tgai (107.8 g) and Solvent B (107.8 g) were mixed and then emulsified into 198.08 g of aqueous wheat protein solution (containing 2.96% w:w of Protein C and 0.44% w:w of surfactant A, pH 6.3) with an ULTRA-TURRAX DF 25 for 3 min at 18 000 rpm. 108.01 g of an aqueous chitosan solution (containing 4% w:w of polysaccharide A) at pH 4.65 (adjusted with acetic acid) was added to the emulsion. Time to add the chitosan solution: 45 min

[0589] The mixture was stirred for 60 min with a propeller stirrer at 150 rpm.

[0590] Then, 17.43 g of an aqueous ammonium polyphosphate solution (Exolite AP 420), containing 0.25% w:w ammonium polyphosphate, was added over 15 minutes.

[0591] The mixture was stirred for 1 h at room temperature.

[0592] The mean d50 of the capsule suspension obtained was 2.7 m and the d90 was 7 m.

[0593] The so prepared capsules were compared to Dimethenamid-P Emulsifiable Concentrate (EC)

[0594] They showed excellent efficacies in controlling CAPBP, GALAP, STEME, VIDAR, LAMPU weeds, also SETVI, ECHCG, DIGSA grasses under greenhouse conditions.

[0595] In the field the so prepared capsules showed good handling, better crop tolerance and similar weed control when compared to EC on soybean, and cotton.

Example 8

[0596] S-Metalochlor liquid tgai (179 g) and Solvent B (89 g) were mixed and then emulsified into 207.73 g of aqueous wheat protein solution (containing 3.23% w:w of Protein C and 0.49% w:w of surfactant A, pH 6.3) with an ULTRA-TURRAX DF 25 for 3 min at 18 000 rpm. 124.62 g of an aqueous chitosan solution (containing 4.3% w:w of polysaccharide A) at pH 4.65 (adjusted with acetic acid) was added to the emulsion. Time to add the chitosan solution: 45 min

[0597] The mixture was stirred for 60 min with a propeller stirrer at 150 rpm.

[0598] Then, 20.05 g of an aqueous ammonium polyphosphate solution (Exolite AP 420), containing 0.25% w:w ammonium polyphosphate, was added over 15 minutes.

[0599] The mixture was stirred for 1 h 00 at room temperature. Finally, 0.61 g of 2-phenoxyethanol were added and the mixture was stirred for an additional 10 minutes at room temperature.

[0600] The mean d50 of the capsule suspension obtained was 3.8 m and the d90 was 8.9 m.

Example 9

[0601] Acetochlor liquid tgai (247.94 g) was emulsified into 247.94 g of aqueous wheat protein solution (containing 2.72% w:w of Protein C and 0.41% w:w of surfactant A, pH 6.3) with an ULTRATURRAX DF 25 for 3 min at 18 000 rpm.

[0602] 124.96 g of an aqueous chitosan solution (containing 4% w:w of polysaccharide A) at pH 4.65 (adjusted with acetic acid) was added to the emulsion. Time to add the chitosan solution: 45 min

[0603] The mixture was stirred for 60 min with a propeller stirrer at 150 rpm.

[0604] Then, 20.05 g of an aqueous ammonium polyphosphate solution (Exolite AP 420), containing 0.25% w:w ammonium polyphosphate, was added over 15 minutes.

[0605] The mixture was stirred for 1 h 00 at room temperature. Finally, 0.64 g of 2-phenoxyethanol were added and the mixture was stirred for an additional 10 minutes at room temperature.

[0606] The mean d50 of the capsule suspension obtained was 9.5 m and the d90 was 21 m.