NEW MICROCAPSULES FOR AGRICULTURAL APPLICATIONS

Abstract

Microcapsule comprising a shell and a core, wherein said core comprises a pesticide and a water immiscible solvent and wherein said shell comprises an organic polymer, wherein said microcapsule further comprises a protective colloid of silica particles.

Claims

1. A microcapsule comprising a shell and a core, wherein said core comprises a pesticide and a water immiscible solvent and wherein said shell comprises an organic polymer, wherein said microcapsule further comprises a protective colloid of silica particles.

2. The microcapsule according to claim 1, wherein said protective colloid comprises silica particles and a stabilizer polymer SP.

3. The microcapsule according to claim 1, wherein said stabilizer polymer SP is a cellulose derivative C.

4. The microcapsule according to claim 3, wherein said cellulose derivative C is a methylhydroxy-(C.sub.1-C.sub.4)-alkylcellulose.

5. The microcapsule according to claim 1, wherein said water immiscible solvent has a solubility in water of less than 2 g/l.

6. The microcapsule according to claim 1, wherein said pesticide is pyraclostrobin and wherein the core comprises pyraclostrobin in dissolved form.

7. The microcapsule according to claim 1, wherein said polymer shell comprises a polyurea or a polyacrylate.

8. The microcapsule according to claim 1, wherein said microcapsule has an average diameter d.sub.90 of 0.1 μm to 50 μm.

9. A method for preparing a microcapsule according to claim 1, comprising: A) providing a water phase comprising disperse silica and optionally a stabilizer polymer SP; B) providing an oil phase comprising at least one water immiscible solvent, a pesticide, a polymerizable monomer M, and optionally at least one surfactant; C) emulsifying phase B) into phase A); and D) polymerizing said at least one polymerizable monomer M.

10. The method according to claim 9, wherein said polymerizable monomer M is selected from at least one polyisocyanate or at least one ethylenically unsaturated monomer.

11. The method according to claim 9, wherein said polymerization of said polymerizable monomer M is carried out by radical polymerization of at least one (meth)acrylate or by reaction of at least one polyisocyanate with at least one polyamine.

12. A formulation comprising the a microcapsule claim 1 dispersed in a solvent or a solvent mixture.

13. A method for controlling phytopathogenic fungi, where the microcapsules according to claim 1 are allowed to act on the phytopathogenic fungi, their habitat, or the plants to be protected from the phytopathogenic fungi or their habitat or the soil.

14. The method according to claim 9, wherein the pesticide is pyraclostrobin.

Description

EXAMPLES

[0163]

TABLE-US-00001 Materials used Surfactant A C16/C18 alkyl ether alkoxylate Surfactant B C12/14 alcohol, ethoxylated, propoxylated Silica A Silica having a specific surface area (N2, multipoint following ISO 9277) of 180 m2/g, a particle size (d50, laser diffraction following ISO 13320:2009) of 14.0 μm, loss on drying (2 h at 105°, following ISO 787-2) of <= 7.0%, pH value of 6.5, sieve residue 45 μm (spray following ISO 3262-19) of <= 1.5% Biocide A aqueous solution comprising 2.5 wt % methylisothiazolinone and 2.5 wt % benzisothiazolinone Polyisocyanate A Oligomer of MDI with an isocyanate content of 31.5 g/100 g, viscosity at 25° C. according to DIN 53 018: 180-250 mPa*s Solvent A Aromatic hydrocarbon fluid having an initial boiling point of 247° C. and a final boiling point of 301° C. (ASTM D86) Inorganic Clay A disk-shaped crystals 25 nm in diameter of synthetic layered silicate (85-90 wt %) and tetrasodium pyrophosphate (7-10 wt. %) Cellulose Methylhydroxypropylcellulose with an Derivative A average molecular mass MW of 25 kDa and a viscosity in a 2 wt % aqueous solution at 21° C. of 450 mPas.

Example 1

[0164] Water Phase:

[0165] 563.35 g DI water (DI=fully deionized water)

[0166] 80.00 g of a 50% strength by weight silica sol (specific surface area ca. 80 m2/g)

[0167] 12.00 g of a 5% strength by weight aqueous solution of Cellulose Derivative A

[0168] 1.60 g of a 2.5% strength by weight aqueous sodium nitrite solution

[0169] 12.00 g of a 20% strength by weight nitric acid solution in water

[0170] Feed 1

[0171] 204.00 g Solvent A

[0172] 136.00 g Pyraclostrobin

[0173] 36.00 g methyl methacrylate

[0174] 24.00 g pentaerythritol triacrylate

[0175] Feed 2:

[0176] 0.80 g tert-butylperpivalate

[0177] Feed 3:

[0178] 30.00 g of a 2% strength by weight aqueous solution sodium peroxodisulfate

[0179] Feed 4:

[0180] 1.31 g of a 25% strength by weight aqueous solution of sodium hydroxide

[0181] Feed 5:

[0182] 2.29 g Xanthan gum

[0183] 11.43 1,2-propane diol

[0184] 2.29 g DI water

[0185] The water phase above was introduced at 25° C. Feed 1 was added and the mixture was dispersed for 40 minutes at 3500 rpm. Following the introduction of feed 2, the reaction batch was heated to 67° C. in 60 minutes and then further heated to 90° C. in 60 minutes. Then, while holding the temperature constant at 90° C., feed 3 was added in 90 minutes. Afterwards, the temperature was held constant at 90° C. for another 60 minutes. The dispersion was then cooled to room temperature and feed 4 and feed 5 was added. The size of the capsules obtained is displayed in Table 1.

Example 2

[0186] Water Phase:

[0187] 564.60 g DI water (DI=fully deionized water)

[0188] 200.00 g of a 50% strength by weight silica sol (specific surface area ca. 80 m2/g)

[0189] 12.00 g of a 5% by weight aqueous solution Cellulose Derivative A

[0190] 1.60 g of a 2.5% strength by weight aqueous sodium nitrite solution

[0191] 12.00 g of a 20% strength by weight nitric acid solution in water

[0192] Feed 1

[0193] 168.00 g Solvent A

[0194] 112.00 g Pyraclostrobin

[0195] 48.00 g methyl methacrylate

[0196] 24.00 g pentaerythritol triacrylate

[0197] 24.00 g 1,4-butane diol diacrylate

[0198] 24.00 g methacrylic acid

[0199] Feed 2:

[0200] 1.60 g tert-butylperpivalate

[0201] Feed 3:

[0202] 60.00 g of a 2% strength by weight aqueous solution sodium peroxodisulfate

[0203] Feed 4:

[0204] 5.71 g of a 25% strength by weight aqueous solution of sodium hydroxide

[0205] Feed 5:

[0206] 2.50 g Xanthan gum

[0207] 12.50 1,2-propane diol

[0208] 2.5 g DI water

[0209] The water phase above was introduced at 25° C. Feed 1 was added and the mixture was dispersed for 40 minutes at 3500 rpm. Following the introduction of feed 2, the reaction batch was heated to 67° C. in 60 minutes and then further heated to 90° C. in 60 minutes. Then, while holding the temperature constant at 90° C., feed 3 was added in 90 minutes. Afterwards, the temperature was held constant at 90° C. for another 60 minutes. The dispersion was then cooled to room temperature and feed 4 and feed 5 was added. The size of the capsules obtained is displayed in Table 1.

Example 3

[0210] Water Phase:

[0211] 396.68 g DI water (DI=fully deionized water)

[0212] 53.00 g of a 50% strength by weight silica sol (specific surface area ca. 80 m2/g)

[0213] 7.95 g of a 5% strength by weight aqueous solution of Cellulose Derivative A

[0214] 1.06 g of a 2.5% strength by weight aqueous sodium nitrite solution

[0215] 1.65 g of a 20% strength by weight nitric acid solution in water

[0216] Feed 1

[0217] 114.88 g Solvent A

[0218] 76.58 g Pyraclostrobin

[0219] 33.79 g Surfactant A

[0220] 9.94 g methyl methacrylate

[0221] 9.94 g methacrylic acid

[0222] 10.14 g 2-hydroxy ethyl methacrylate

[0223] 10.14 g ethylene glycol dimethacrylate

[0224] Feed 2:

[0225] 0.53 g tert-butylperpivalate

[0226] Feed 3:

[0227] 19.88 g of a 2% strength by weight aqueous solution sodium peroxodisulfate

[0228] Feed 4:

[0229] 2.00 g Xanthan gum

[0230] 1.60 g Biocide A (5% by weight)

[0231] 40.00 g glycerin

[0232] 123.2 g DI water

[0233] Feed 5:

[0234] 85.00 g Surfactant B

[0235] 4.25 g Silica A

[0236] Feed 6:

[0237] 0.90 g of a 25% strength by weight aqueous solution of sodium hydroxide

[0238] The water phase above was introduced at 25° C. Feed 1 was added and the mixture was dispersed for 40 minutes at 3500 rpm. Following the introduction of feed 2, the reaction batch was heated to 67° C. in 60 minutes and then further heated to 90° C. in 60 minutes. Then, while holding the temperature constant at 90° C., feed 3 was added in 90 minutes. Afterwards, the temperature was held constant at 90° C. for another 60 minutes. The dispersion was then cooled to room temperature and feed 4, feed 5 and feed 6 was added. The size of the capsules obtained is displayed in Table 1.

Example 4

[0239] Water Phase:

[0240] 396.68 g DI water (DI=fully deionized water)

[0241] 53.00 g of a 50% strength by weight silica sol (specific surface area ca. 80 m2/g)

[0242] 7.95 g of a 5% strength by weight aqueous solution of Cellulose Derivative A

[0243] 1.06 g of a 2.5% strength by weight aqueous sodium nitrite solution

[0244] 1.65 g of a 20% strength by weight nitric acid solution in water

[0245] Feed 1

[0246] 114.88 g Solvent A

[0247] 76.58 g Pyraclostrobin

[0248] 33.79 g Surfactant A

[0249] 15.90 g methyl methacrylate

[0250] 7.95 g pentaerythritol triacrylate

[0251] 7.95 g 1,4-butane diol diacrylate

[0252] 7.95 g methacrylic acid

[0253] Feed 2:

[0254] 0.53 g tert-butylperpivalate

[0255] Feed 3:

[0256] 19.88 g of a 2% strength by weight aqueous solution sodium peroxodisulfate

[0257] Feed 4:

[0258] 2.00 g Xanthan gum

[0259] 1.60 g Biocide A (5% by weight)

[0260] 40.00 g glycerin

[0261] 123.2 g DI water

[0262] Feed 5:

[0263] 85.00 g Surfactant B

[0264] 4.25 g Silica A

[0265] Feed 6:

[0266] 1.80 g of a 25% strength by weight aqueous solution of sodium hydroxide

[0267] The water phase above was introduced at 25° C. Feed 1 was added and the mixture was dispersed for 40 minutes at 3500 rpm. Following the introduction of feed 2, the reaction batch was heated to 67° C. in 60 minutes and then further heated to 90° C. in 60 minutes. Then, while holding the temperature constant at 90° C., feed 3 was added in 90 minutes. Afterwards, the temperature was held constant at 90° C. for another 60 minutes. The dispersion was then cooled to room temperature and feed 4 and feed 5 was added. The size of the capsules obtained is displayed in Table 1.

Example 5

[0268] Water Phase:

[0269] 658.00 g DI water (DI=fully deionized water)

[0270] 90.00 g of a 50% strength by weight silica sol (specific surface area ca. 80 m2/g)

[0271] 13.50 g of a 5% strength by weight aqueous solution of Cellulose Derivative A

[0272] 9.87 g of a 50% strength by weight citric acid in water

[0273] Feed 1

[0274] 195.08 g Solvent A

[0275] 130.05 g Pyraclostrobin

[0276] 57.38 g Surfactant A

[0277] 16.88 g methyl methacrylate

[0278] 16.88 g methacrylic acid

[0279] 17.22 g 2-hydroxy ethyl methacrylate

[0280] 17.22 g ethylene glycol dimethacrylate

[0281] Feed 2:

[0282] 0.90 g tert-butylperpivalate

[0283] Feed 3:

[0284] 33.75 g of a 2% strength by weight aqueous solution sodium peroxodisulfate

[0285] Feed 4:

[0286] 3.38 g Xanthan gum

[0287] 2.70 g Biocide A (5% by weight)

[0288] 67.60 g glycerin

[0289] 208.52 g DI water

[0290] Feed 5:

[0291] 143.91.00 g Surfactant B

[0292] 7.19 g Silica A

[0293] Feed 6:

[0294] 1.50 g of a 25% strength by weight aqueous solution of sodium hydroxide

[0295] The water phase above was introduced at 25° C. Feed 1 was added and the mixture was dispersed for 40 minutes at 3500 rpm. Following the introduction of feed 2, the reaction batch was heated to 67° C. in 60 minutes and then further heated to 90° C. in 60 minutes. Then, while holding the temperature constant at 90° C., feed 3 was added in 90 minutes. Afterwards, the temperature was held constant at 90° C. for another 60 minutes. The dispersion was then cooled to room temperature and feed 4 and feed 5 was added. The size of the capsules obtained is displayed in Table 1.

Example 6

[0296] Water Phase:

[0297] 668.00 g DI water (DI=fully deionized water)

[0298] 90.00 g of a 50% strength by weight silica sol (specific surface area ca. 80 m2/g)

[0299] 13.50 g of a 5% strength by weight aqueous solution of Cellulose Derivative A

[0300] 17.00 g of a 50% strength by weight citric acid in water

[0301] Feed 1

[0302] 206.4 g Solvent A

[0303] 137.60 g Pyraclostrobin

[0304] 60.75 g Surfactant A

[0305] 11.25 g methyl methacrylate

[0306] 11.25 g methacrylic acid

[0307] 11.48 g 2-hydroxy ethyl methacrylate

[0308] 11.48 g ethylene glycol dimethacrylate

[0309] Feed 2:

[0310] 0.60 g tert-butylperpivalate

[0311] Feed 3:

[0312] 22.50 g of a 2% strength by weight aqueous solution sodium peroxodisulfate

[0313] Feed 4:

[0314] 3.38 g Xanthan gum

[0315] 2.70 g Biocide A (5% by weight)

[0316] 67.60 g glycerin

[0317] 208.52 g DI water

[0318] Feed 5:

[0319] 143.91.00 g Surfactant B

[0320] 7.19 g Silica A

[0321] Feed 6:

[0322] 1.50 g of a 25% strength by weight aqueous solution of sodium hydroxide

[0323] The water phase above was introduced at 25° C. Feed 1 was added and the mixture was dispersed for 40 minutes at 3500 rpm. Following the introduction of feed 2, the reaction batch was heated to 67° C. in 60 minutes and then further heated to 90° C. in 60 minutes. Then, while holding the temperature constant at 90° C., feed 3 was added in 90 minutes. Afterwards, the temperature was held constant at 90° C. for another 60 minutes. The dispersion was then cooled to room temperature and feed 4 and feed 5 was added. The size of the capsules obtained is displayed in Table 1.

Example 7

[0324] Water Phase:

[0325] 692.20 g DI water (DI=fully deionized water)

[0326] 134.55 g of a 10% strength by weight aqueous solution of a polyvinyl alcohol with a molecular weight of Mw˜130 000 g/mol and a degree of hydrolysis of 88 mol %

[0327] Feed 1

[0328] 194.40 g Solvent A

[0329] 129.60 g Pyraclostrobin

[0330] 57.38 g Surfactant A

[0331] 16.88 g methyl methacrylate

[0332] 16.88 g methacrylic acid

[0333] 17.22 g 2-hydroxy ethyl methacrylate

[0334] 17.22 g ethylene glycol dimethacrylate

[0335] Feed 2:

[0336] 0.90 g tert-butylperpivalate

[0337] Feed 3:

[0338] 33.75 g of a 2% strength by weight aqueous solution sodium peroxodisulfate

[0339] Feed 4:

[0340] 3.38 g Xanthan gum

[0341] 2.70 g Biocide A (5% by weight)

[0342] 67.60 g glycerin

[0343] 208.52 g DI water

[0344] Feed 5:

[0345] 143.91.00 g Surfactant B

[0346] 7.19 g Silica A

[0347] Feed 6:

[0348] 1.50 g of a 25% strength by weight aqueous solution of sodium hydroxide

[0349] The water phase above was introduced at 25° C. Feed 1 was added and the mixture was dispersed for 40 minutes at 3500 rpm. Following the introduction of feed 2, the reaction batch was heated to 67° C. in 60 minutes and then further heated to 90° C. in 60 minutes. Then, while holding the temperature constant at 90° C., feed 3 was added in 90 minutes. Afterwards, the temperature was held constant at 90° C. for another 60 minutes. The dispersion was then cooled to room temperature and feed 4 and feed 5 was added. The size of the capsules obtained is displayed in Table 1.

Example 8

[0350] Water Phase:

[0351] 702.80 g DI water (DI=fully deionized water)

[0352] 134.55 g of a 10% strength by weight aqueous solution of a polyvinyl alcohol with a molecular weight of Mw˜130 000 g/mol and a degree of hydrolysis of 88 mol %

[0353] Feed 1

[0354] 205.86 g Solvent A

[0355] 137.60 g Pyraclostrobin

[0356] 60.75 g Surfactant A

[0357] 11.25 g methyl methacrylate

[0358] 11.25 g methacrylic acid

[0359] 11.48 g 2-hydroxy ethyl methacrylate

[0360] 11.48 g ethylene glycol dimethacrylate

[0361] Feed 2:

[0362] 0.60 g tert-butylperpivalate

[0363] Feed 3:

[0364] 22.50 g of a 2% strength by weight aqueous solution sodium peroxodisulfate

[0365] Feed 4:

[0366] 3.38 g Xanthan gum

[0367] 2.70 g Biocide A (5% by weight)

[0368] 67.60 g glycerin

[0369] 208.52 g DI water

[0370] Feed 5:

[0371] 143.91.00 g Surfactant B

[0372] 7.19 g Silica A

[0373] Feed 6:

[0374] 1.50 g of a 25% strength by weight aqueous solution of sodium hydroxide

[0375] The water phase above was introduced at 25° C. Feed 1 was added and the mixture was dispersed for 40 minutes at 3500 rpm. Following the introduction of feed 2, the reaction batch was heated to 67° C. in 60 minutes and then further heated to 90° C. in 60 minutes. Then, while holding the temperature constant at 90° C., feed 3 was added in 90 minutes. Afterwards, the temperature was held constant at 90° C. for another 60 minutes. The dispersion was then cooled to room temperature and feed 4 and feed 5 was added. The size of the capsules obtained is displayed in Table 1.

Example 9

[0376] Water Phase:

[0377] 713.40 g DI water (DI=fully deionized water)

[0378] 134.55 g of a 10% strength by weight aqueous solution of a polyvinyl alcohol with a molecular weight of Mw˜130 000 g/mol and a degree of hydrolysis of 88 mol %

[0379] Feed 1

[0380] 217.29 g Solvent A

[0381] 144.87 g Pyraclostrobin

[0382] 63.91 g Surfactant A

[0383] 5.61 g methyl methacrylate

[0384] 5.61 g methacrylic acid

[0385] 5.72 g 2-hydroxy ethyl methacrylate

[0386] 5.72 g ethylene glycol dimethacrylate

[0387] Feed 2:

[0388] 0.30 g tert-butylperpivalate

[0389] Feed 3:

[0390] 11.25 g of a 2% strength by weight aqueous solution sodium peroxodisulfate

[0391] Feed 4:

[0392] 3.38 g Xanthan gum

[0393] 2.70 g Biocide A (5% by weight)

[0394] 67.60 g glycerin

[0395] 208.52 g DI water

[0396] Feed 5:

[0397] 143.91.00 g Surfactant B

[0398] 7.19 g Silica A

[0399] Feed 6:

[0400] 1.50 g of a 25% strength by weight aqueous solution of sodium hydroxide

[0401] The water phase above was introduced at 25° C. Feed 1 was added and the mixture was dispersed for 40 minutes at 3500 rpm. Following the introduction of feed 2, the reaction batch was heated to 67° C. in 60 minutes and then further heated to 90° C. in 60 minutes. Then, while holding the temperature constant at 90° C., feed 3 was added in 90 minutes. Afterwards, the temperature was held constant at 90° C. for another 60 minutes. The dispersion was then cooled to room temperature and feed 4 and feed 5 was added. The size of the capsules obtained is displayed in Table 1.

Example 10

[0402] Water Phase:

[0403] 535.20 g DI water (DI=fully deionized water)

[0404] 30.00 g of Inorganic Clay A

[0405] 36.27 g of sodium chloride

[0406] Feed 1

[0407] 137.70 g Solvent A

[0408] 91.80 g Pyraclostrobin

[0409] 40.50 g Surfactant A

[0410] 7.50 g methyl methacrylate

[0411] 7.50 g methacrylic acid

[0412] 7.65 g 2-hydroxy ethyl methacrylate

[0413] 7.65 g ethylene glycol dimethacrylate

[0414] Feed 2:

[0415] 0.40 g tert-butylperpivalate

[0416] Feed 3:

[0417] 15.00 g of a 2% strength by weight aqueous solution sodium peroxodisulfate

[0418] Feed 4:

[0419] 3.38 g Xanthan gum

[0420] 2.70 g Biocide A (5% by weight)

[0421] 67.60 g glycerin

[0422] 208.52 g DI water

[0423] Feed 5:

[0424] 143.91.00 g Surfactant B

[0425] 7.19 g Silica A

[0426] Feed 6:

[0427] 1.50 g of a 25% strength by weight aqueous solution of sodium hydroxide

[0428] The water phase above was introduced at 25° C. Feed 1 was added and the mixture was dispersed for 40 minutes at 3500 rpm. Following the introduction of feed 2, the reaction batch was heated to 67° C. in 60 minutes and then further heated to 90° C. in 60 minutes. Then, while holding the temperature constant at 90° C., feed 3 was added in 90 minutes. Afterwards, the temperature was held constant at 90° C. for another 60 minutes. The dispersion was then cooled to room temperature and feed 4 and feed 5 was added. The size of the capsules obtained is displayed in Table 1.

Example 11

[0429] For formulations obtained in examples 1 to 10, the average size (d50) of the microcapsules was determined by laser diffraction according to ISO 13320, Particle Size Analysis—Laser Diffraction Methods, Dec. 1, 2009.

[0430] Furthermore, the formulations obtained in examples 1 to 10 were subjected to a release test according to the following procedure:

[0431] In a glass beaker, equipped with a magnetic stirrer, 100 ml of a 10% solution of an ethylene-oxide/propylene oxide block co-polymer surfactant in demineralized water was placed. To this solution 50 μl of the formulation were added and after 10 min an aliquot was taken for analysis of free pyraclostrobin. For this analysis, the aliquot was firstly filtered through a 22 μm syringe filter, then injected into an HPLC equipment for quantitative analysis of pyraclostrobin. The value obtained represents the released pyraclostrobin in a 10% surfactant solution after 10 minutes at room temperature (21° C.).

[0432] The results are shown in table 1:

TABLE-US-00002 TABLE 1 Analytical Results: Average d50 particle size and release properties of capsules according to examples 1 to 10 Release of pesticide according to example 11 [% of released pesticide after D (50)/μm 10 min]. Example 1   9.73 Example 2   6.72 Example 3  12.26 Example 4  10.55 Example 5   8.94  0.60 Example 6  10.24  1.30 Example 7   4.00 59.8  Example 8   2.50 75.3  Example 9   2.04 94.8  Example 10  5.03 14.3 

Example 12

[0433] Water Phase:

[0434] 177.00 g DI water (DI=fully deionized water)

[0435] 12.00 g of a 50% strength by weight silica sol (specific surface area ca. 80 m2/g)

[0436] 3.60 g of a 5% strength by weight aqueous solution of Cellulose Derivative A

[0437] 0.48 g of a 2.5% strength by weight aqueous sodium nitrite solution

[0438] 0.49 g of a 20% strength by weight nitric acid solution in water

[0439] Feed 1

[0440] 46.84 g Solvent A

[0441] 46.94 g Pyraclostrobin

[0442] 23.80 g Surfactant A

[0443] 2.40 g Polyisocyanate A

[0444] Feed 2:

[0445] 2.80 g of a 25% strength by weight aqueous solution of tetraethylene pentamine

[0446] The water phase above was introduced at 25° C. Feed 1 was added and the mixture was dispersed for 3 minutes at 21000 rpm. Afterwards, Feed 2 was added slowly. Subsequently, the mixture was heated to 80° C. in one hour and kept at that temperature for two hours. The dispersion was then cooled to room temperature. The size of the capsules obtained is displayed in Table 2.

Example 13

[0447] Water Phase:

[0448] 212.75 g DI water (DI=fully deionized water)

[0449] 12.00 g of a 50% strength by weight silica sol (specific surface area ca. 80 m2/g)

[0450] 3.60 g of a 5% strength by weight aqueous solution of Cellulose Derivative A

[0451] 0.48 g of a 2.5% strength by weight aqueous sodium nitrite solution

[0452] 0.49 g of a 20% strength by weight nitric acid solution in water

[0453] Feed 1

[0454] 59.98 g Solvent A

[0455] 39.98 g Pyraclostrobin

[0456] 17.64 g Surfactant A

[0457] 2.40 g Polyisocyanate A

[0458] Feed 2:

[0459] 2.80 g of a 25% strength by weight aqueous solution of tetraethylene pentamine

[0460] Feed 3:

[0461] 1.07 g Xanthan gum

[0462] 0.86 g Biocide A (5% by weight)

[0463] 21.46 g glycerin

[0464] 66.11 g DI water

[0465] Feed 4:

[0466] 42.93 g Surfactant B

[0467] 2.15 g Silica A

[0468] 0.64 g of a 50% strength by weight aqueous solution of citric acid

[0469] The water phase above was introduced at 25° C. Feed 1 was added and the mixture was dispersed for 3 minutes at 21000 rpm. Afterwards, Feed 2 was added slowly. Subsequently, the mixture was heated to 80° C. in one hour and kept at that temperature for two hours. The dispersion was then cooled to room temperature and feed 3 and feed 4 were added. The size of the capsules obtained is displayed in Table 2.

Example 14

[0470] Water Phase:

[0471] 588.50 g DI water (DI=fully deionized water)

[0472] 40.00 g of a 50% strength by weight silica sol (specific surface area ca. 80 m2/g)

[0473] 12.00 g of a 5% strength by weight aqueous solution of Cellulose Derivative A 1.60 g of a 2.5% strength by weight aqueous sodium nitrite solution

[0474] 12.00 g of a 20% strength by weight nitric acid solution in water

[0475] Feed 1

[0476] 235.2 g Solvent A

[0477] 156.80 g Pyraclostrobin

[0478] 8.00 g Polyisocyanate A

[0479] Feed 2:

[0480] 9.30 g of a 25% strength by weight aqueous solution of tetraethylene pentamine

[0481] Feed 3:

[0482] 1.67 g of a 50% strength by weight aqueous solution of citric acid

[0483] Feed 4:

[0484] 2.20 g Xanthan gum

[0485] 11.00 g 1,2-propane diol

[0486] 2.20 g DI water

[0487] The water phase above was introduced at 25° C. Feed 1 was added and the mixture was dispersed for 40 minutes at 3500 rpm. Afterwards, Feed 2 was added slowly. Subsequently, the mixture was heated to 80° C. in one hour and kept at that temperature for two hours. The dispersion was then cooled to room temperature and feed 3 and feed 4 were added. The size of the capsules obtained is displayed in Table 2.

Example 15

[0488] Water Phase:

[0489] 149.60 g DI water (DI=fully deionized water)

[0490] 30.00 g of a 50% strength by weight silica sol (specific surface area ca. 80 m2/g)

[0491] 0.60 g of a 5% strength by weight aqueous solution of Cellulose Derivative A

[0492] 0.60 g of a 20% strength by weight nitric acid solution in water

[0493] Feed 1

[0494] 48.86 g Solvent A

[0495] 46.94 g Pyraclostrobin

[0496] 23.80 g Surfactant A

[0497] 2.40 g Polyisocyanate A

[0498] Feed 2:

[0499] 6.00 g sodium lignosulfonate

[0500] 0.60 g of a 20% strength by weight nitric acid solution in water

[0501] Feed 3:

[0502] 2.80 g of a 25% strength by weight aqueous solution of tetraethylene pentamine

[0503] The water phase above was introduced at 25° C. Feed 1 was added and the mixture was dispersed for 3 minutes at 26000 rpm. Then feed 2 was added and mixed in by dispersing for 2 minutes at 26000 rpm. Afterwards, Feed 3 was added slowly. Subsequently, the mixture was heated to 80° C. in one hour and kept at that temperature for two hours. The dispersion was then cooled to room temperature. The size of the capsules obtained is displayed in Table 2.

Example 16

[0504] Water Phase:

[0505] 217.55 g DI water (DI=fully deionized water)

[0506] 6.0 g of polyvinylalcohol

[0507] 0.48 g of a 2.5% strength by weight aqueous sodium nitrite solution

[0508] Feed 1

[0509] 59.98 g Solvent A

[0510] 39.98 g Pyraclostrobin

[0511] 17.64 g Surfactant A

[0512] 2.40 g Polyisocyanate A

[0513] Feed 2:

[0514] 2.80 g of a 25% strength by weight aqueous solution of tetraethylene pentamine

[0515] Feed 3:

[0516] 1.07 g Xanthan gum

[0517] 0.86 g Biocide A (5% by weight)

[0518] 21.46 g glycerine

[0519] 66.11 g DI water

[0520] Feed 4:

[0521] 42.93 g Surfactant B

[0522] 2.15 g Silica A

[0523] 0.64 g of a 50% strength by weight aqueous solution of citric acid

[0524] The water phase above was introduced at 25° C. Feed 1 was added and the mixture was dispersed for 3 minutes at 21000 rpm. Afterwards, Feed 2 was added slowly. Subsequently, the mixture was heated to 80° C. in one hour and kept at that temperature for two hours. The dispersion was then cooled to room temperature and feed 3 and feed 4 were added. The size of the capsules obtained is displayed in Table 2.

Example 17

[0525] For formulations obtained in examples 12 to 16, the average size (d50) of the microcapsules was determined by laser diffraction according to ISO 13320, Particle Size Analysis—Laser Diffraction Methods, Dec. 1, 2009.

[0526] Furthermore, the formulations obtained in examples 12 to 16 were subjected to a release test according to the following procedure:

[0527] In a glass beaker, equipped with a magnetic stirrer, 100 ml of a 10% solution of an ethylene-oxide/propylene oxide block co-polymer surfactant in demineralized water was placed. To this solution 50 μl of the formulation were added and after 10 min an aliquot was taken for analysis of free pyraclostrobin. For this analysis, the aliquot was firstly filtered through a 22 μm syringe filter, then injected into an HPLC equipment for quantitative analysis of pyraclostrobin. The value obtained represents the released pyraclostrobin in a 10% surfactant solution after 10 minutes at room temperature (21° C.).

[0528] The results are shown in table 2:

TABLE-US-00003 TABLE 2 Analytical Results: Average d50 particle size and release properties of capsules according to examples 12 to 16 Release of pesticide according to example 17 [% of released pesticide after D (50)/μm 10 min]. Example 12 14.00  0.80 Example 13 10.72 23.9  Example 14 16.40 0.2 Example 15  4.38 19.4  Example 16  8.01 84.1