WO2017021159A1 - Microcapsule compositions comprising pyrimethanil - Google Patents

Microcapsule compositions comprising pyrimethanil Download PDF

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Publication number
WO2017021159A1
WO2017021159A1 PCT/EP2016/067367 EP2016067367W WO2017021159A1 WO 2017021159 A1 WO2017021159 A1 WO 2017021159A1 EP 2016067367 W EP2016067367 W EP 2016067367W WO 2017021159 A1 WO2017021159 A1 WO 2017021159A1
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WIPO (PCT)
Prior art keywords
microcapsules
pyrimethanil
aqueous suspension
acid
weight
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PCT/EP2016/067367
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French (fr)
Inventor
Bastian Marten Noller
Yannick Fuchs
Nadine RIEDIGER
Rebekka VON BENTEN
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Basf Se
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Priority to EP16742268.2A priority Critical patent/EP3331362A1/en
Priority to MX2018001496A priority patent/MX2018001496A/en
Priority to BR112018002038A priority patent/BR112018002038A2/en
Publication of WO2017021159A1 publication Critical patent/WO2017021159A1/en
Priority to CONC2018/0002206A priority patent/CO2018002206A2/en

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    • A—HUMAN NECESSITIES
    • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
    • A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
    • A01N43/00—Biocides, pest repellants or attractants, or plant growth regulators containing heterocyclic compounds
    • A01N43/48—Biocides, pest repellants or attractants, or plant growth regulators containing heterocyclic compounds having rings with two nitrogen atoms as the only ring hetero atoms
    • A01N43/54—1,3-Diazines; Hydrogenated 1,3-diazines

Definitions

  • Microcapsule compositions comprising pyrimethanil
  • the present invention relates to microcapsules comprising pyrimethanil, to a method for their preparation to compositions comprising such microcapsules and to the use of these microcapsules and compositions for controlling fungal diseases.
  • Pyrimethanil is known as a fungicide and described in DD-A 151 404. Pyrimathanil has a lUPAC name N(4,6-dimethylpyrimidin-2-yl)aniline and can be described by the following formula I
  • WO 2004/004461 describes mixtures of pyrimethanil.
  • Pyrimethanil has an amino-acid synthesis perturbing effect and inhibits the methionine biosynthesis of fungal pathogens.
  • pyrimethanil prevents diseases caused by a wide spectrum of fungi, including Alternaria spp., Bortrytis cinerea, Cercospora spp., Cladosporium spp., Colleto- trichum spp, M on ilia spp., Mycosphaerella spp., Penicillium spp., and Venturia spp.
  • Pyrimethanil is a solid fungicide with a melting point which lays at 96,3°C, the density at 1.15 g/cm 3 and the vapor pressure at 2.2 mPa at 25°C. Pyrimethanil has a very low solubility in water of 0.12 g/L.
  • Fungicides such as pyrimehtanil
  • aqueous spray liquors which are prepared by diluting a concentrate formulation with water.
  • pesticide compounds may be formulated in solid forms, such as wettable powders (WP) and water- dispersible granules (WG), as well as in liquid forms, such as emulsions, emulsifiable concentrates (EC), suspoemulsions (SE) or suspension concentrates (SC).
  • WP wettable powders
  • WG water- dispersible granules
  • liquid forms such as emulsions, emulsifiable concentrates (EC), suspoemulsions (SE) or suspension concentrates (SC).
  • EC emulsifiable concentrates
  • SE suspoemulsions
  • SC suspension concentrates
  • the formulations can be easily diluted with water and that the dilution remains stable for a certain time without separation of the active ingredient, as this may cause clogging of the spraying nozz
  • Pyrimethanil is typically formulated as SC formulation.
  • the known formulations of pyrimethanil have a disadvantage compared with the formulation of other fungicides. This is due to the high volatility (vapour pressure) of pyrimethanil. A lot of a.i. does not maintain on the leaf after spray- ing and evapourates into the atmosphere. This leads to the loss of efficacy of such formulations. Therefore it is an object of the present invention to provide a formulation of pyrimethanil in which the high volatility of a.i. can be reduced and thus the efficacy of the formulation will be increased.
  • microcapsules of solid pyrimethanil surrounded or embedded by an aminoplast polymer provide for reduced volatility of pyrimethanil.
  • a first aspect of the invention relates to microcapsules, comprising solid pyrimethanil, which is surrounded or embedded by an aminoplast polymer, and a second aspect of the invention relates to a composition comprising such microcapsules.
  • microcapsules according to the invention have the advantage that the aminoplast polymer reduces volatility of pyrimethanil. At the same time aminoplast polymer according to the invention allows the controlled release of pyrimethanil whereby the a.i. will be controlled absorb by the crop and will not evaporate after spraying into the atmosphere. Thus it is achieved that the microcapsules of the present invention provide a higher fungicidal activity as compared to regu- lar SC formulations.
  • microcapsules according to the present invention pyrimethanil is less prone to degradation.
  • microcapsules of the present invention provide for both high physical and chemical stability over prolonged storage periods while maintaining the biological efficacy of pyrimethanil.
  • microcapsules of the present invention can be easily formulated.
  • Microencapsulation can be principally achieved by coacervation techniques, spray drying, fluidized-bed coating, electrostatic microencapsulation or in-situ polymerization. These techniques provide active compound parti- cles, wherein the active compound is surrounded by a polymeric wall material.
  • a first reactant e.g. a polyfunctional isocanate or acid chloride
  • a polyfunctional compound having a complemen- tary reactivity with regard to the first reactant, e.g. an diamine or diol (see H. Mollet, A. Grubenmann, loc. cit. page 394 and US 4,107,292, US 5,705,174, US 5,910,314, WO 0027519, EP 8207, US 2004/1 15280).
  • the polymerization occurring at the interface between the active substance and the aqueous phase completely encloses the fine droplets of active substance with a thin membrane of polyurea or polyamide.
  • a further in-situ polymerization technique includes microencapsulation by using aminoplasts such as melamine formaldehyde resins (MF resisn) or urea formaldehyde resins (UF resins) or melamine formaldehyde urea resins (MUF resins).
  • the aminoplast resins are used in the form of their prepolymers or pre-condensates, which are added to an aqueous suspension of the material to be encepsulated and cured by heating and/or altering the pH of the reaction mixture to effect polymerization of the prepolymers.
  • US 5,462,915 describes an improved process for micro-encapsulation of water-insoluble pesticides, which comprises adding to a suspension of the pesticide a liquid aminoplast prepolymer and curing the prepolymer at temperatures of above 100°C. The method was applied for microencapsulation of water-insoluble salts of dicamba. A similar process is known from WO
  • WO 96/03041 describes a microcapsule composition of pesticides, wherein the microcapsules have an outer aminoplast layer and an inner wax coating deposited around pesticide compound.
  • Modern techniques of microencapsulation include the radical suspension polymerization of water-insoluble acrylate monomers with (meth)acrylic acid and optionally polyfunctional monomers in the presence of an o/w-emulsion of the pesticide compound (see e.g. WO 2012/101070) or the radical emulsion polymerization of an aqueous monomer emulsions, wherein the pesticide is dissolved or suspended in the monomer droplets (see e.g. WO 2005/102044, WO2006/094792, WO 2006/094978).
  • microencapsulation may improve the acute toxicity of a pesticide or reduce degrada- tion, it is often difficult to achieve.
  • aggregation of the pesticide particles during or after encapsulation is the main problem, if one encapsulation method, which may work for a particular pesticide compound, does not necessarily work for another pesticide compound.
  • the solid material tends to agglomerate thereby forming large particles of active ingredient particles, which are embedded in the polymer matrix. A thus obtained suspension is usually no longer suitable for agricultural use.
  • solid pyrimethanil can be efficiently micro-encapsulated by using aminoplast pre-condensates and performing the process described hereinafter.
  • a second aspect of the present invention relates to a process for preparing
  • solid pyrimethanil is surrounded or embedded by an aminoplast polymer.
  • solid pyrimethanil forms the core material which is surrounded or embedded by at least one aminoplast polymer.
  • the aminoplast polymers may form a regular or irregular shell which surrounds the core material. It is not necessary that the aminoplast polymer forms a completely closed shell. Frequently, however, the shell will completely surround the core material like a membrane, thereby forming a barrier between the core material and the surrounding material.
  • microcapsules according to the invention build so-called particles with "domain structure" comprising between 3 and 10 crystals of pyrimethanil surrounded or embedded by the aminoplast polymer.
  • aldehydes such as formaldehyde, glyoxal, propanal, or glutaraldehyde
  • aminoplast polymers are polycondensates of melamine and formaldehyde (melamine-formaldehyde resins or MF resins), including resins derived from wholly or partially etherified melamine-formaldehyde condensates, urea-formaldehyde resins (UF resins), thiourea-formaldehyde resins (TUF resins), polycondensates of melamine, urea and formaldehyde (MUF resins), including resins derived from wholly or partially etherified melamine-urea-formaldehyde condensates, polycondensates of melamine, thiourea and formaldehyde (MTUF resins, including resins derived from wholly or partially etherified melamine-thiourea-formaldehyde condensates, urea-glutaraldehyde resins, benzoguanamine-formaldehyde polycondensates, dic
  • Suitable aminoplast polymers for microencapsulation are known and can be found, inter alia, in Kirk-Othmer, Encyclopedia of Chemical Technology, 3rd edition, Vol. 2, pp. 440-469, the prior art cited in the introductory part, US 4,918,317, EP 26914, EP 218887, EP 319337, EP 383,337, EP 415273, DE 19833347, DE 198351 14 and WO 01/51 197.
  • the aminoplast polymer is selected form the group consisting of melamine formaldehyde resins (MF) and/or urea formaldehyde resins (UF) and/or melamine urea formaldehyde resins (MUF).
  • the molar ratios of urea or thiourea to formaldehyde are generally in the range from 1 : 0.8 to 1 : 4, in particular from 1 : 1.5 to 1 : 4, especially from 1 :2 to 1 : 3.5. If glu- taraldehyde is used instead of formaldehyde, the molar ratios of urea or thiourea to glutaralde- hyde may in particular be in the range from 1 : 1.2 to 1 : 3, especially in the range from 1 : 1.5 to 1 : 2.5.
  • the molar ratios of melamine to formaldehyde are generally in the range from 1 : 1.5 to 1 : 10, in particular from 1 : 3 to 1 : 8 preferably 1 : 4 to 1 :6.
  • the molar ratios of melamine + urea or thiourea to formaldehyde are generally in the range from 1 : 0.8 to 1 : 9, in particular from 1 : 2 to 1 : 8 preferably 1 : 3 to 1 :6.
  • the molar ratio of urea or thiourea to melamine may be in the range from 50 : 1 to 1 : 100 and in particular from 30 : 1 to 1 : 30.
  • the pre-condensates may be used in the form of etherified pre-condensates of amino compound and aldehyde.
  • these etherified pre-condensates the methylol groups formed by the reaction of the amino groups with formaldehyde with an alkanol or an alkandiol, in particular with a Ci-C4-alkanol such as methanol, eth- anol, n-propanol or n-butano, in particular methanol, or a C2-C4-alkandiol such as ethylene gly- col.
  • the degree of etherification of these resins can be adjusted by the molar ratio of amino groups to alkanol which is typically in the range from 10 : 1 to 1 : 10, preferably in the range from 2 : 1 to 1 : 5.
  • the aminoplast polymers, which surround or embed the solid pyrimethanil are most preferably selected from the group consisting of melamine-formaldehyde resins, including melamine- formaldehyde resins derived from wholly or partially etherified melamine-formaldehyde condensates, and urea-formaldehyde resins and mixtures thereof.
  • the aminoplast polymers, which surrounds or embeds the solid pyrimethanil is a melamine-formaldehyde resin, derived from wholly or partially etherified melamine-formaldehyde condensates, which may contain small amount, e.g. 1 to 20 mol.-%, based on melamine, of urea.
  • the amount of aminoplast polymers, which surround or embed the solid pyrimethanil is preferably from 1 to 40 % by weight, in particular from 1 to 35 % by weight and especially from 5 to 25 % by weight, based on total capsule weight. According to one most preferred embodiment the amount aminoplast polymers, which surround or embed the solid pyrimethanil, is 10 to 20 % by weight, based on total capsule weight.
  • the encapsulat- ing polymers of the microcapsules of the invention, which surround or embed the solid pyrimethanil may comprise further water-insoluble polymers. However, the amount of such polymers will generally not exceed 20 % of the total amount of encapsulating polymers, and will preferably not exceed 10 % by weight of the total amount of encapsulating polymers.
  • the solid pyrimethanil which is surrounded or embedded by at least one aminoplast polymer, may be any known form of solid pyrimethanil, including amorphous pyrimethanil and in particular crystalline pyrimethanil, e.g. the crystalline anhydrate of pyrimethanil as described in WO 08/043835 or a crystalline hydrate of pyrimethanil as described in WO 08/043836.
  • the core material of the microcapsules may contain an oil, e.g. a hydrocarbon solvent such as an aromatic, paraffinic or isoparaffinic hydrocarbon, having preferably a boiling point above 100°C, a vegetable oil such as corn oil, rapeseed oil, or a fatty acid ester such as Ci-Cio-alkylester of a Cio-C22-fatty acid, in particular methyl- or ethyl esters of vegetable oils such as rapeseed oil methyl ester or corn oil methyl ester.
  • the core material does not contain an oil as defined herein or less than 10 % by weight, based on the weight of the core material, of an oil.
  • the core material of the microcapsules may further contain a further pesticide compound, in particular a pesticide compound or a safener, having preferably a reduced water solubility, which generally does not exceed 10 g/l, in particular 5 g/l or even 1 g/l at 25°C (deionised water).
  • a further pesticide compound in particular a pesticide compound or a safener, having preferably a reduced water solubility, which generally does not exceed 10 g/l, in particular 5 g/l or even 1 g/l at 25°C (deionised water).
  • solid pyrimethanil makes up at least 80 %, in particular at least 90 % of the pesticides contained in the microcapsules.
  • pesticide refers to at least one pesticide selected from the group of fungicides and insecticides. Also mixtures of pesticides from two or more of the aforementioned classes may be used. An expert is familiar with such pesticides, which might be found in the Pesticide Manual, 14th Ed. (2006), The British Crop Protection Council, London or e-Pesticide Manual V5.1 , ISBN 978 1 901396 84 3 among other publications.
  • Suitable fungicides are
  • coumoxystrobin dimoxystrobin, enestroburin, fenaminstrobin, fenoxy- strobin/flufenoxystrobin, fluoxastrobin, kresoxim-methyl, metominostrobin, orysastrobin, picoxystrobin, pyraclostrobin, pyrametostrobin, pyraoxystrobin, trifloxystrobin, 2-[2-(2,5- dimethyl-phenoxymethyl)-phenyl]-3-methoxy-acrylic acid methyl ester and 2-(2-(3-(2,6-di- chlorophenyl)-1-methyl-allylideneaminooxymethyl)-phenyl)-2-methoxyimino-N-methyl- acetamide; and pyribencarb, triclopyricarb/chlorodincarb, famoxadone, fenamidone;
  • - inhibitors of complex II e. g. carboxamides: benodanil, bixafen, boscalid, carboxin, fen- furam, fluopyram, flutolanil, fluxapyroxad, furametpyr, isopyrazam, mepronil, oxycarboxin, penflufen, penthiopyrad, sedaxane, tecloftalam, thifluzamide, N-(4'- trifluoromethylthiobiphenyl-2-yl)-3-difluoromethyl-1-methyl-1 H-pyrazole-4-carboxamide, N-(2- (1 ,3,3-trimethyl-butyl)-phenyl)-1 ,3-dimethyl-5-fluoro-1 H-pyrazole-4-carboxamide, N-[9- (dichloromethylene)-l ,2,3,4-tetrahydro-1 ,4-methanonaphthalen-5-yl]-3-(
  • respiration inhibitors e.g. complex I, uncouplers: diflumetorim, (5,8-difluoroquinazolin- 4-yl)- ⁇ 2-[2-fluoro-4-(4-trifluoromethylpyridin-2-yloxy)-phenyl]-ethyl ⁇ -amine; nitrophenyl deri- vates: binapacryl, dinobuton, dinocap, fluazinam; ferimzone; organometal compounds: ame- toctradin; and silthiofam;
  • complex I uncouplers
  • SBI fungicides Sterol biosynthesis inhibitors
  • DMI fungicides C14 demethylase inhibitors
  • triazoles azaconazole, bitertanol, bromucona- zole, cyproconazole, difenoconazole, diniconazole, diniconazole-M, epoxiconazole, fenbu- conazole, fluquinconazole, flusilazole, flutriafol, hexaconazole, imibenconazole, ipconazole, metconazole, myclobutanil, oxpoconazole, paclobutrazole, penconazole, propiconazole, prothioconazole, simeconazole, tebuconazole, tetraconazole, triadimefon, triadimenol, triti- conazole, uniconazole; imidazoles: imazal
  • phenylamides or acyl amino acid fungicides benalaxyl, benalaxyl-M, kiralaxyl, metalaxyl, metalaxyl-M (mefenoxam), ofurace, oxadixyl;
  • hymexazole hymexazole, octhilinone, oxolinic acid, bupirimate, 5-fluorocytosine, 5-fluoro-2-(p- tolylmethoxy)pyrimidin-4-amine, 5-fluoro-2-(4-fluorophenylmethoxy)pyrimidin-4-amine;
  • tubulin inhibitors such as benzimidazoles, thiophanates: benomyl, carbendazim, fuber- idazole, thiabendazole, thiophanate-methyl; triazolopyrimidines: 5-chloro-7-(4-methyl- piperidin-1-yl)-6-(2,4,6-trifluorophenyl)-[1 ,2,4]triazolo[1 ,5-a]pyrimidine
  • cell division inhibitors diethofencarb, ethaboxam, pencycuron, fluopicolide, zoxamide, metrafenone, pyriofenone;
  • - methionine synthesis inhibitors anilino-pyrimidines: cyprodinil, mepanipyrim, pyrimethanil;
  • blasticidin-S blasticidin-S, kasugamycin, kasugamycin hydrochloride-hydrate, mildiomycin, streptomycin, oxytetracyclin, polyoxine, validamycin A;
  • MAP / histidine kinase inhibitors fluoroimid, iprodione, procymidone, vinclozolin, fenpiclonil, fludioxonil;
  • - Phospholipid biosynthesis inhibitors edifenphos, iprobenfos, pyrazophos, isoprothiolane;
  • lipid peroxidation dicloran, quintozene, tecnazene, tolclofos-methyl, biphenyl, chloroneb, etridiazole;
  • phospholipid biosynthesis and cell wall deposition dimethomorph, flumorph, mandipropa- mid, pyrimorph, benthiavalicarb, iprovalicarb, valifenalate and N-(1-(1-(4-cyano-phenyl)- ethanesulfonyl)-but-2-yl) carbamic acid-(4-fluorophenyl) ester;
  • organochlorine compounds e.g. phthalimides, sulfamides, chloronitriles: anilazine, , di- chlofluanid, dichlorophen, flusulfamide, hexachlorobenzene, pentachlorphenole and its salts, phthalide, tolylfluanid, N-(4-chloro-2-nitro-phenyl)-N-ethyl-4-methyl-benzenesulfonamide;
  • organochlorine compounds e.g. phthalimides, sulfamides, chloronitriles: anilazine, , di- chlofluanid, dichlorophen, flusulfamide, hexachlorobenzene, pentachlorphenole and its salts, phthalide, tolylfluanid, N-(4-chloro-2-nitro-phenyl)-N-ethyl-4-methyl-benzenesulfonamide;
  • guanidine dodine, , guazatine, guazatine-acetate, iminoctadine, iminoctadine-triacetate, iminoctadine-tris(albesilate),;
  • glucan synthesis validamycin, polyoxin B; melanin synthesis inhibitors: pyroqui- lon, tricyclazole, carpropamid, dicyclomet, fenoxanil;
  • organo(thio)phosphates acephate, azamethiphos, azinphos-methyl, chlorpyrifos, chlorpyrifos-methyl, chlorfenvinphos, diazinon, dichlorvos, dicrotophos, dimethoate, disulfoton, ethion, fenitrothion, fenthion, isoxathion, malathion, methamidophos, methidathion, methyl- parathion, mevinphos, monocrotophos, oxydemeton-methyl, paraoxon, parathion, phenthoate, phosalone, phosmet, phosphamidon, phorate, phoxim, pirimiphos-methyl, profenofos, prothi- ofos, sulprophos, tetrachlorvinphos, terbufos, triazophos, trichlorfon;
  • - carbamates alanycarb, aldicarb, bendiocarb, benfuracarb, carbaryl, carbofuran, carbosul- fan, fenoxycarb, furathiocarb, methiocarb, methomyl, oxamyl, pirimicarb, propoxur, thiodi- carb, triazamate;
  • - pyrethroids allethrin, bifenthrin, cyfluthrin, cyhalothrin, cyphenothrin, cypermethrin, alpha- cypermethrin, beta-cypermethrin, zeta-cypermethrin, deltamethrin, esfenvalerate, etofenprox, fenpropathrin, fenvalerate, imiprothrin, lambda-cyhalothrin, permethrin, prallethrin, pyrethrin I and II, resmethrin, silafluofen, tau-fluvalinate, tefluthrin, tetramethrin, tralomethrin, transfluthrin, profluthrin, dimefluthrin, flucythirnate;
  • - insect growth regulators a) chitin synthesis inhibitors: benzoylureas: chlorfluazuron, cy- ramazin, diflubenzuron, flucycloxuron, flufenoxuron, hexaflumuron, lufenuron, novaluron, teflubenzuron, triflumuron; buprofezin, diofenolan, hexythiazox, etoxazole, clofentazine; b) ecdysone antagonists: halofenozide, methoxyfenozide, tebufenozide, azadirachtin; c) juve- noids: pyriproxyfen, methoprene, fenoxycarb; d) lipid biosynthesis inhibitors: spirodiclofen, spiromesifen, spirotetramat;
  • nicotinic receptor agonists/antagonists compounds clothianidin, dinotefuran, imidacloprid, thiamethoxam, nitenpyram, acetamiprid, thiacloprid, 1 -(2-chloro-thiazol-5-ylmethyl)-2- nitrimino-3,5-dimethyl-[1 ,3,5]triazinane;
  • - GABA antagonist compounds endosulfan, ethiprole, fipronil, vaniliprole, pyrafluprole,
  • - macrocyclic lactone insecticides abamectin, emamectin, milbemectin, lepimectin, spinosad, spinetoram;
  • oxidative phosphorylation inhibitors cyhexatin, diafenthiuron, fenbutatin oxide, propargite;
  • cryomazine cryomazine
  • the microcapsules of the present invention are discrete particles having usually a particle size of less than 50 ⁇ .
  • the particle size of the microcapsule particles i.e. their diameter, will in general not exceed 40 ⁇ , preferably not exceed 35 ⁇ and in particular not exceed 30 ⁇ .
  • the particle size given is the so called dgo-value, which has to be understood as the value that is not exceeded by the diameters of at least 90 % by weight of the microcapsule particles, the microcapsule particles have an average particle diameter, herein also termed dso-value, ranging from 1 to 25 ⁇ , in particular from 1 .5 to 20 ⁇ , especially from 1 to 10 ⁇ .
  • the dso- value is defined as the value that is above the diameters of 50 % by weight of the particles and below the diameters of 50 % by weight of the particles.
  • the dgo value as well as the dso value can be calculated from the particle size distribution of the microcapsule particles.
  • the particle size distribution of the microcapsule particles i.e. the diameters
  • the particle size distribution of the microcapsule particles can be determined by conven- tional methods such as dynamic or static light-scattering of an aqueous dispersion of the microcapsule composition, e.g. at 25 °C and a concentration in the range of 0.1 to 1 % by weight.
  • composition comprises the microcapsules as defined above.
  • composition according to the invention comprises further at least one anionic polymeric surfactant having a plurality of sulfate or sulfonate groups.
  • the microcapsules contain at least one anionic polymeric surface-active substance A, hereinafter anionic polymeric surfactant, which contains a plurality of anionic groups, such as carboxylate groups, sulfonate groups, phosphonate groups, sulfate groups and/or phosphate groups.
  • anionic groups are selected from sulfonate groups.
  • Examples for poly- meric surfactant A are the surfactants of the following groups A1 to A3, including the salts thereof:
  • A.1 lignin based sulfonic acids such as lignosulfonic acid, ethoxylated ignosulfonic acid or oxidized lignins;
  • arylsulfonic acid formaldehyde condensates and arylsulfonic acid formaldehyde urea con- densates such as naphthalene sulfonic acid formaldehyde condensates, phenol sulfonic acid formaldehyde condensates, cresol sulfonic acid formaldehyde condensates etc,
  • anionic groups in these anionic polymeric surfactants may be partially or fully neutralized.
  • Suitable counter ions are alkalimetal ions such as sodium, potassium, earthalkaline ions such as magnesium or calcium, and ammonium.
  • the anionic groups are preferably at least partly neutralized.
  • the polymeric surfactant A.3 are in particular selected from homo- or copolymers of i) at least one monoethylenically unsaturated monomer M1 having a sulfonic acid group, such as vinylsulfonic acid, allylsulfonic acid, styrene sulfonic acid, vinyltoluene sulfonic acid, (meth)acrylate monomers having a sulfonic acid group, such as 2-acryloxyethylsulfonic acid, 2-acryloxypropylsulfonic or 4-acryloxybutylsulfonic acid, and (meth)acrylamide mon- omer having a sulfonic acid group, such as 2-acrylamidoethylsulfonic acid, 2- acrylamidopropylsulfonic acid or 2-acrylamido-2-methylpropane sulfonic acid ii) optionally with one or more monoethylenically unsaturated comonomers
  • the polymeric surfactant A comprises or is selected from homo- or copolymers of i) monomers M1 , which are selected from (meth)acrylate monomers having a sulfonic acid group, such as 2-acryloxyethylsulfonic acid, 2-acryloxypropylsulfonic or 4- acryloxybutylsulfonic acid, and (meth)acrylamide monomer having a sulfonic acid group, such as 2-acrylamidoethylsulfonic acid, 2-acrylamidopropylsulfonic acid or 2-acrylamido- 2-methylpropane sulfonic acid, .
  • monomers M1 which are selected from (meth)acrylate monomers having a sulfonic acid group, such as 2-acryloxyethylsulfonic acid, 2-acryloxypropylsulfonic or 4- acryloxybutylsulfonic acid, and (meth)acrylamide monomer having a sulfonic acid group, such as 2-acryl
  • monoethylenically unsaturated comonomers M2 different from monomers M1 such as styrene, C1-C4-alkylacrylat.es, C1-C4-alkylmethacrylat.es, acryla- mide, methacrylamide, acrylic acid, methacrylic acid, C1-C4-alkylacrylat.es, C1-C4- alkylmethacrylates.
  • the polymeric surfactant A comprises or is selected from homo- or copolymers of i) monomers M1 , which is 2-acrylamido-2-methylpropane sulfonic acid, .
  • monoethylenically unsaturated comonomers M2 different from monomers M1 such as styrene, C1-C4-alkylacrylat.es, C1-C4-alkylmethacrylat.es, acryla- mide, methacrylamide, acrylic acid, methacrylic acid, C1-C4-alkylacrylat.es, C1-C4- alkylmethacrylates.
  • the amount of monomers M1 is preferably at least 50 % by weight, based on the total amount of monomers forming the polymeric surfactant.
  • polymeric surfactants A which are homo- or copolymers of monomers M1 , wherein the amount of monomers M1 is at least 90 % by weight, based on the total amount of monomers forming the polymeric surfactant.
  • These polymers are known, e.g. from commercially available under the tradenames Lupasol S Lupasol PA 140 (from BASF SE), and Wettol D1.
  • the amount of the anionic polymeric surfactant A in the composition is preferably from 0.1 to 50 % by weight, in particular from 3 to 40 % by weight and most preferred from 5 to 30 % by weight, based on the total amount of pyrimethanil and aminoplast polymer.
  • compositions according to the invention may also contain a nonionic surface-active compound (nonionic surfactant) which provide for the stabilization of an aqueous formulation comprising the microcapsules.
  • Suitable anionic surface-active compounds B are surfactants having one anionic group, which is selected from phosphate or phosphonate groups and sulfate or sulfonate groups, the latter compounds being preferred. These surfactants B will usually be included into the microcapsule composition in the form of their salts, in particular the sodium, potassium or ammonium salts.
  • anionic surfactants B include the salts of alkylsulfonates, alkylsulfates, alkylphosphates, semi-esters of alkoxylated alkanols with sulfuric acid or phos- phoric acid, alkylarylsulfonates, alkylarylphosphates, semi-esters of alkoxylated alkylphenols with sulfuric acid or phosphoric acid and semi-esters of alkoxylated mono-, di- or tristyrylphenols with sulfuric acid or phosphoric acid.
  • anionic surfactants B those of the formula I are preferred:
  • R is a hydrocarbon radical having from 8 to 40 carbon atoms and preferably from 12 to 30 carbon atoms and optionally one oxygen atom;
  • A is independently from one another 1 ,2-ethylene, 1 ,2-propylene or 1 ,3-propylene, especial- ly 1 ,2-ethylene;
  • m is from 0 to 50, preferably from 0 to 30 and especially preferred from 0 to 20;
  • X is SO3M or PO3M2 with M being selected from H, alkaline metal ions, such as K and Na, alkaline earth metal ions, such as 1 ⁇ 2 Ca and 1 ⁇ 2 Mg and ammonium.
  • M is an alkaline metal ion and especially sodium.
  • suitable hydrocarbon radicals R having from 8 to 40 carbon atoms are alkyl having from 8 to 40 and preferably from 12 to 30 carbon atoms, phenyl, which may be substituted with one or two alkyl radicals having from 4 to 20 carbon atoms, phenyl, which is substituted with a phenoxy radical, wherein phenyl and/or phenoxy may contain an alkyl radical having from 4 to 20 carbon atoms, tristyrylphenyl radical etc.
  • the radical R in formula I is a tristyrylphenyl radical.
  • anionic surfactants B which are of the formula (I), wherein R, m and X have the following meanings:
  • R is alkyl having from 8 to 30, in particular from 10 to 20 carbon atoms
  • X is is SO3M with m being selected from alkaline metal ions, such as K and Na, alkaline earth metal ions, such as 1 ⁇ 2 Ca and 1 ⁇ 2 Mg and ammonium.
  • alkaline metal ions such as K and Na
  • alkaline earth metal ions such as 1 ⁇ 2 Ca and 1 ⁇ 2 Mg and ammonium.
  • M is an alkaline metal and especially sodium.
  • the amount of anionic surfactant B, in particular the surface-active compound of the formula I is preferably from 0.01 to 1 % by weight, in particular from 0.1 to 0.5 % by weight, based on the total amount of the aqueous suspension. If present, the amount of anionic surfactant B, in particular the surface-active compound of the formula I, is preferably chosen such that the weight ratio of anionic polymeric surfactant A to anionic surfactant B is from 1 : 1 to 20 : 1 in particular from 2 : 1 to 10 : 1 .
  • the suspension comprises at least one anionic emulsifier in addition to the polymeric surfactant.
  • the microcapsule composition is in the form of an aqueous suspension.
  • a suspension contains the microcapsules of solid pyrimethanil as a disperse phase, and an aqueous medium as the continuous phase.
  • the aqueous suspension may be obtained by the process for preparing the microcapsule composi- tion as described herein. It may also be obtained by re-dispersing a solid microcapsule composition as described herein in an aqueous medium.
  • aqueous medium stands for the liquid phase of the composition and comprises an aqueous solvent and optionally compounds dissolved therein, e.g. surfactants as mentioned above, and if present, conventional one or more conventional formulation additives, such as thickeners or biocides.
  • the aqueous solvent of the aqueous suspension is either water or a mixture thereof with a water-miscible organic solvent, such as Ci-C4-alkanols, e.g. methanol, etha- nol, n-propanol, isopropanol, n-butanol, 2-butanol, isobutanol, or tert.
  • the amount of water in the aqueous solvent is at least 50 % by weight, in particular at least 80 % by weight or at least 90 % by weight, based on the aqueous solvent.
  • the aqueous solvent may consist mainly of water, i.e. water makes up at least 95 % by weight of the total amount of solvent present in the suspension.
  • the aqueous solvent may also be a mixture of the aforementioned water-miscible organic solvent and water.
  • the weight ratio of water to water-miscible organic solvent in the aqueous solvent preferably is in the range of from 99 : 1 to 1 : 1 ; more preferably in the range of from 50 : 1 to 3 : 1 ; and most preferably in the range of from 20 : 1 to 4 : 1 .
  • the amount of organic solvent may be from 1 to 50 % by weight, more preferably from 2 to 25% by weight, and most preferably from 5 to 20% by weight, based on the total weight of the aqueous solvent.
  • the aqueous suspension will usually contain the microcapsules in an amount of at least 5 % by weight and the amount may be as high as 50 % by weight or even higher, in each case based on the total weight of the aqueous suspension and calculated as the total amount of aminoplast- polymer and pyrimethanil.
  • the aqueous suspension will contain the microcapsules in an amount from 10 to 45 % by weight, in particular from 20 to 40 % by weight, in each case based on the total weight of the aqueous suspension and calculated as the total amount of ami- noplast-polymer and pyrimethanil.
  • the concentration of pyrimethanil in the aqueous suspension will frequently be in the range from 5 to 40 % by weight, in particular from 15 to 30 % by weight, based on the total weight of the aqueous suspension.
  • the concentration of the polymeric anionic surfactant A in the aqueous suspension of step (iii) will frequently be in the range from 0.1 to 15 % by weight, in particular from 0.2 to 6 % by weight, based on the total weight of the aqueous suspension.
  • the concentration of the anionic surfactant B in the aqueous suspension of step (iii) will frequently be in the range from 0.05 to 15 % by weight, in particular from 0.1 to 6 % by weight, based on the total weight of the aqueous suspension.
  • the aqueous compositions according to the invention may also comprise customary formulation auxiliaries, such as viscosity-modifying additives (thickeners), antifoam agents, preservatives, buffers, inorganic dispersants, etc, which are usually employed in aqueous formulations of herbicides.
  • auxiliaries may be incorporated into the aqueous suspension after step iii) of the preparation process described herein has been carried out.
  • the amount of additives will generally not exceed 10 % by weight, in particular 5 % by weight of the total weight of the aqueous suspension.
  • Suitable inorganic dispersants also termed anticaking agents, for preventing agglutination of the microcapsule particles, are silica (such as, for example Sipernat ® 22 from Degussa), alumina, calcium carbonate and the like.
  • silica is a preferred inorganic dispersant.
  • the concentration of inorganic dispersants in the final suspension will generally not exceed 2 % by weight, based on the total weight of the final suspension, and, if present, it is preferably in the range from 0.01 to 2 % by weight, in particular from 0.02 to 1 .5 % by weight and especially from 0.1 to 1 % by weight, based on the total weight of the final suspension.
  • Suitable thickeners are compounds which affect the flow behavior of the suspension concen- trate and may assist in stabilizing the aqueous suspension against caking and sedimentation. Mention may be made, in this connection, for example, of commercial thickeners based on polysaccharides, such as methylcellulose, carboxymethylcellulose, hydroxypropylcellulose (Klucel ® grades), Xanthan Gum (commercially available e.g. as Kelzan ® grades from Kelco or Rhodo- pol ® grades from Rhodia), synthetic polymers such as acrylic acid polymers (Carbopol ® grades), polyvinyl alcohol (e.g.
  • Mowiol ® and Poval ® grades from Kuraray or polyvinyl pyrrolones, silicic acid or phyllosilicates such as montmorillonite and bentonites, which may be hydrophobized, (commercially available as Attaclay ® grades and Attaflow ® grades from BASF SE; or as
  • Xanthan Gum is a preferred thickener.
  • the concentration of thickeners in the aqueous suspension will generally not exceed 5 % by weight, based on the total weight of the aqueous suspension, and is preferably in the range from 0.01 to 3.5 % by weight, in particular from 1 to 3 % by weight and especially from 2 to 3,5 % by weight, based on the total weight of the aqueous suspension.
  • Antifoam agents suitable for the formulations according to the invention are, for example, sili- cone emulsions (such as, for example, Silicone SRE-PFL from Wacker or Rhodorsil ® from Bluestar Silicones, FoamStar ® from BASF), long-chain alcohols, fatty acids, organofluorine compounds and mixtures thereof.
  • sili- cone emulsions such as, for example, Silicone SRE-PFL from Wacker or Rhodorsil ® from Bluestar Silicones, FoamStar ® from BASF
  • long-chain alcohols such as, for example, Silicone SRE-PFL from Wacker or Rhodorsil ® from Bluestar Silicones, FoamStar ® from BASF
  • long-chain alcohols such as, for example, Silicone SRE-PFL from Wacker or Rhodorsil ® from Bluestar Silicones, FoamStar ® from BASF
  • long-chain alcohols such as, for example, Silicone SRE-PFL from Wacker or Rhodor
  • Suitable preservatives to prevent microbial spoiling of the compositions of the invention include formaldehyde, alkyl esters of p-hydroxybenzoic acid, sodium benzoate,
  • thiazolinones such as benzisothiazolinone, 5- chloro-2-methyl-4-isothiazolinone, pentachlorophenol, 2,4-dichlorobenzyl alcohol and mixtures thereof.
  • preservatives that are based on isothiazolinones are for example marketed under the trademarks Proxel ® (Arch Chemical), Acticide ® MBS (Thor Chemie) and Kathon ® MK (Rohm & Haas).
  • the aqueous suspension according to the invention may comprise buffers to regulate the pH.
  • buffers are alkali metal salts of weak inorganic or organic acids such as, for example, phosphoric acid, boric acid, acetic acid, propionic acid, citric acid, fumaric acid, tartaric acid, oxalic acid and succinic acid.
  • the aqueous suspensions can be formulated with conventional binders, for example aqueous polymer dispersions, water-soluble resins, for example water-soluble alkyd resins, or waxes.
  • the microcapsule composition is in the form of solid composition.
  • Such a solid composition contains the microcapsules of solid pyrimethanil, optionally one or more surfactants, in particular the polymeric surfactant A and optionally the anionic surfactant B, and optionally an inert solid carrier material.
  • the solid composititions may e.g. be redispersible powders, water-dispersible granules wettable powders and the like.
  • Solid carriers include e.g. mineral earths such as silicas, silica gels, silicates, talc, kaolin, limestone, lime, chalk, bole, loess, clay, dolomite, diatomaceous earth, calcium sulfate, magnesium sulfate, magnesium oxide, ground synthetic materials, fertilizers such as ammonium sulfate, ammonium phosphate, ammonium nitrate, ureas, and products of vegetable origin such as ce- real meal, tree bark meal, wood meal and nutshell meal, cellulose powders, or other solid carriers.
  • mineral earths such as silicas, silica gels, silicates, talc, kaolin, limestone, lime, chalk, bole, loess, clay, dolomite, diatomaceous earth, calcium sulfate, magnesium sulfate, magnesium oxide, ground synthetic materials, fertilizers such as ammonium sulfate, ammonium phosphate, ammonium n
  • the solid compositions according to the invention may also comprise customary formulation auxiliaries, such as antifoam agents, preservatives, buffers, inorganic dispersants, etc, which are usually employed in solid formulations of herbicides.
  • auxiliaries may be incorporated into the solid formulation at any conventional stage of their preparation process.
  • the amount of additives will generally not exceed 10 % by weight, in particular 5 % by weight of the total weight of the solid composition.
  • the solid composition may be obtained from an aqueous suspension which is primarily formed in the process for preparing the microcapsule composition as described herein by removing the aqueous phase from the aqueous suspension. Removal of the aqueous phase can be achieved by either separating the aqueous phase from the solid microparticles, e.g. by centrifugation or filtration. Preferably, the aqueous phase is removed by an evaporation process, such as spray drying or freeze dry.
  • an aqueous suspension or dispersion of pyrimethanil particles is provided;
  • solid pyrimethanil is suspended or dispersed in an aqueous solvent, in particular in water.
  • the aqueous solvent may contain one or more surfactants, in particular at least one polymeric surfactant A as a protective colloid as described above and optionally one or more anionic surfactants B.
  • pyrimethanil is dispersed in water in the presence of surfactants and aminoplast pre-condensate.
  • the particle size of the pyrimethanil particles in the aqueous suspension is less than 45 ⁇ , in particular it will not exceed 45 ⁇ , preferably not exceed 30 ⁇ and in particular not exceed 25 ⁇ .
  • the particle size given is the so called devalue.
  • the active substance particles have an average particle diameter, herein also termed dso-value, ranging from 1 to 25 ⁇ , in particular from 1.2 to 20 ⁇ , especially from 1.5 to 10 ⁇ .
  • the dso-value is defined as the value that is above the diameters of 50 % by weight of the particles and below the diameters of 50 % by weight of the particles.
  • the dgo value as well as the deo value can be calculated from the particle size distribution of the pyrimethanil particles which can be determined by conventional methods such as dynamic light-scattering at 25 °C and a concentration in the range of 0.1 to 1 % by weight.
  • the aqueous suspension of step i) contains at least one anionic polymeric surfactant A, in particular an anionic polymeric surfactant which comprises or is selected from the polymeric surfactants of group A.3.
  • concentration of the polymeric anionic surfactant A, which is in particular selected from the surfactants of group A.3, in the reaction mixture of step iii) will frequently be in the range from 0.1 to 10 % by weight, in particular from 1 to 6 % by weight, based on the total weight of the aqueous suspension.
  • the aqueous suspension of the pyrimethanil particles can be provided by analogy to known methods of preparing aqueous suspensions of pyrimethanil, e.g. as described in WO
  • the method comprises a step i.a), where solid pyrimethanil, in particular a crystalline form of pyrimethanil, such as pyrimethanil anhydrate or one of the hydrate forms, and the aqueous solvent and optionally at least a part of the surfactant are mixed in any conventional mixing device which is capable of providing sufficient shear to form the desired suspension.
  • suitable mixing devices include in particular high shear mixers, such as Ultra-Turrax apparatus, static mixers, e.g. systems having mixing nozzles, agitator bead mills, colloid mills, cone mills and other homogenizers.
  • the sequence in which the individual components are combined is not critical.
  • step i.a) it may be advantageous to carry step i.a) out by firstly mixing the solvent and the surfactant until a homogenous mixture is obtained, and then adding the solid pyrimethanil with shear to said homogenous mixture.
  • the mixture obtained from step i.a), i.e. in the form of a coarse suspension, is then subjected to suitable means for reducing the particle size of the pyrimethanil particles present in the mixture typically to below 40 ⁇ , preferably to below 30 ⁇ and in particular to below 30 ⁇ (D 9 o-value), especially 0.5 to 15 ⁇ (fot wet milling) and 1 to 30 ⁇ (dry milling) (hereinafter step i.b).
  • Step i.b) may be carried out by any physical attrition method, such as grinding, crushing or milling, in particular by wet grinding or wet milling, including e.g. bead milling, hammer milling, jet milling, air classifying milling, pin milling, cryogenic grinding processes and the like. Steps i.a) and i.b) are usually performed subsequent- ly. However it is also possible to perform these steps together.
  • any physical attrition method such as grinding, crushing or milling, in particular by wet grinding or wet milling, including e.g. bead milling, hammer milling, jet milling, air classifying milling, pin milling, cryogenic grinding processes and the like.
  • Steps i.a) and i.b) are usually performed subsequent- ly. However it is also possible to perform these steps together.
  • aqueous suspension of step i) contains further a dispersing agent.
  • step ii) of the method according to the invention an aminoplast pre-condensate is added to the aqueous suspension of step i), which, upon curing in step iii), forms the solid, water- insoluble aminoplast polymer, which embeds or surrounds the solid pyrimethanil particles, be- cause the polycondensation preferentially occurs on the surface of the solid pyrimethanil particles.
  • the amount of aminoplast pre-condensate added in step ii) is chosen such that the desired amount of aminoplast polymer in the final microcapsule composition is achieved.
  • the amount added corresponds to the amount of aminoplast resin in the microcapsules taking into account that the mass is reduced by the amout if water which is formed during the polycon- densation, and is usually in the range 0.5 to 40 % by weight, in particular from 1 to 35 % by weight and especially from 5 to 25 %by weight, based on pyrimethanil and calculated as organic matter.
  • Suitable pre-condensates which can be added in step ii) include pre-condensates of melamine and formaldehyde, including wholly or partially etherified melamine-formaldehyde pre- condensates, urea-formaldehyde pre-condensates, thiourea-formaldehyde pre-condensates, pre-condensates of melamine, urea and formaldehyde (MUF resins), including mixtures of wholly or partially etherified melamine-formaldehyde pre-condensates and urea-formaldehyde pre- condesates, pre-condensates of urea and glutaraldehyde, pre-condensates of benzoguanamine and formaldehyde, mixtures of dicyandiamide and formaldehyde and urea-glyoxal polyconden- sates.
  • Suitable aminoplast pre-condensates for microencapsulation are known and can be found, inter alia, in Kirk-Othmer, Encyclopedia of Chemical Technology, 3rd edition, Vol. 2, pp. 440-469, the prior art cited in the introductory part, US 4,918,317, EP 26914, EP 218887, EP 319337, EP 383,337, EP 415273, DE 19833347, DE 198351 14 and WO 01/51 197.
  • Suitable pre-condensates are commercially available, e. g. Cymel types, such as Cymel® 303, 327, 328 or 385 (etherified melamine formaldehyde resins of Cytec), Maprenal® types, such as
  • the molar ratios of urea or thiourea to formaldehyde are generally in the range from 1 : 0.8 to 1 : 4, in particular from 1 : 1.5 to 1 : 4, especially from 1 :2 to 1 : 3.5.
  • the molar ratios of melamine to formaldehyde are generally in the range from 1 : 1 .5 to 1 : 10, in particular from 1 : 3 to 1 : 8 preferably 1 : 4 to 1 :6.
  • the molar ratios of melamine + urea or thiourea to formaldehyde are generally in the range from 1 : 0.8 to 1 : 9, in particular from 1 : 2 to 1 : 8 preferably 1 : 3 to 1 :6.
  • the molar ratio of urea or thiourea to melamine may be in the range from 50 : 1 to 1 : 100 and in particular from 30 : 1 to 1 : 30.
  • the pre-condensates may be used in the form of etherified pre-condensates of amino compound and aldehyde.
  • these etherified pre-condensates the methylol groups formed by the reaction of the amino groups with formaldehyde with an alkanol or an alkandiol, in particular with a Ci-C4-alkanol such as methanol, ethanol, n-propanol or n-butanol, in particular methanol, or a C2-C4-alkandiol such as ethylene glycol.
  • the degree of etherification of these resins can be adjusted by the molar ratio of amino groups to alkanol which is typically in the range from 10 : 1 to 1 : 10, preferably in the range from 2 : 1 to 1 : 5.
  • the pre-condensates are most preferably selected from the group consisting of melamine- formaldehyde resins, including wholly or partially etherified melamine-formaldehyde pre- condensates, and urea-formaldehyde pre-condensates and mixtures thereof.
  • the pre-condensate is a wholly or partially etherified melamine-formaldehyde condensate, which may contain small amounts, e.g. 1 to 20 mol.-%, based on melamine, of urea.
  • Addition of the pre-condensate to the aqueous suspension is normally achieved by adding the pre-condensate in the form of an aqueous or alcoholic solution of the pre-condensate to the aqueous suspension or by mixing suitable amounts of the dissolved pre-condensate.
  • suitable mixing devices such as stirrers or inline-mixers are used in order to achieve a uniform distribution of the pre-condensate in the aqueous suspension. It may be beneficial to add the pre-condensate, preferably in the form of a solution, to the aqueous suspension of pyrime- thanil with stirring.
  • the addition of the pre-condensate is performed under conditions, where the polycondensation reaction is slow or does not occur, e.g. where either the pH of the aqueous suspension at least pH 6, e.g. in the range form pH 6 to pH 10, or where the temperature does not exceed 30°C or both.
  • the polycondensation of the aminoplast pre-condensate can be affected in a well-known manner, e.g. by lowering the pH of the aqueous suspension or by heating the aqueous suspension or combinations of these measures.
  • the aminoplast pre- condensate is converted into a water-insoluble aminoplast resin, which precipitates from the aqueous phase and deposits preferably on the surface of the solid pyrimethanil particles, thereby embedding or surrounding the solid pyrimethanil particles.
  • the polycondensation of the aminoplast is performed at pH less than pH 6, in par- ticular at a pH of at most pH 5, e.g. in the range of pH 0 to 6, more particularly in the range from pH 1 to 5 or in the range from pH 2 to 4.
  • the pH of the aqueous suspension is usually adjusted by addition of suitable amounts of an organic or inorganic acid, such as sulfuric acid, hydrochloric acid, phosphoric acid, a carboxylic acid including alkanoic acids, alkandioic acids or hydroxycarboxylic acids, such as formic acid, acetic acid, propionic acid, oxalic acid, malic acid or citric acid, and alkyl or arylsulfonic acids such as methanesulfonic acid or toluenesulfonic acid.
  • an organic or inorganic acid such as sulfuric acid, hydrochloric acid, phosphoric acid, a carboxylic acid including alkanoic acids, alkandioic acids or hydroxycarboxylic acids, such as formic acid, acetic acid, propionic acid, oxalic acid, malic acid or citric acid, and alkyl or arylsulfonic acids such as methanesulfonic acid or toluenes
  • the polycondensation of the aminoplast pre-condensate is performed at elevated temperature, in particular at a temperature of at least 30 °C, in particular at least 40 °C or at least 50°C, e.g. at a temperature in the range of 30 to 100°C, in particular in the range of 40 to 95°C or in the range of 50 to 90 °C. It may be possible to effect the start of the polycondensation of the aminoplast at a comparatively low temperature, e.g. a temperature in the range of 30 to 65°C or 35 to 60°C and then complete the polycondensation reaction at a higher temperature of e.g. 50 to 100°C or 60 to 90°C.
  • the time for completing the polycondensation may vary, depending on the reactivity of the pre-condensate, the temperature and the pH of the aqueous suspension and may take from 1 h to 24 h, in particular from 2 to 12 h.
  • the polycondensation reaction is at least partly performed at temperatures of at least 50°C, in particular at least 60°C, e.g. for 1 to 8 h at a temperature in the range from 50 to 100°C, in particular 60 to 90°C.
  • aqueous suspension of the pyrimethanil microcapsule particles may be neutralized by the addition of a base.
  • the pH of the suspension is adjusted to a pH of at least 6, e.g. a pH in the range of pH 6 to 10, in particular in the range of pH 6.5 to 9.0.
  • the microcapsules can be isolated, e.g. by filtration or centrifugation, or the aqueous suspension may be spray-dried, granulated or freeze-dried, to obtain a solid composition in the form of a powder or granules.
  • the solid composition may be redispersed or formulated by using formulation auxiliaries as described above.
  • the method comprises as step iv) a stabilization of the capsule sus- pension by formulation.
  • nonionic surfactants of formula II include the neutral surface-active compounds of the formula II,
  • R' is a hydrocarbon radical having from 8 to 40 and more preferably from 12 to 30 carbon atoms and optionally one oxygen atom,
  • B is C2-C4-alkane-1 ,2-diyl such as 1 ,2-ethylene, 1 ,2-propylene or 1 ,2-butylene or a combina- tion thereof and more preferred 1 ,2-ethylene or a combination thereof with 1 ,2-propylene, and
  • n is from 3 to 100, preferably from 4 to 50 and more preferred from 5 to 40.
  • Suitable hydrocarbon radials R' include the radicals mentioned for R.
  • the radical R' is a phenyl radical being substituted with one C4-C18- alkyl group.
  • the amount of nonionic surfactant, in particular the surface-active compound of the formula II, is in the formulation preferably from 1 to 150 g/L, in particular from 2 to 60 g/L.
  • the composition does not contain nonionic surfactant or less than 1 % by weight of nonionic surfactant, in particular less than 0.5 % by weight of nonionic surfactant, based on the total amount of pyrimethanil and aminoplast polymer.
  • Suitable bactericides are bronopol and isothiazoli- none derivatives such as alkylisothiazolinones and benzisothiazolinones.
  • the amount of biocide in the final formulation ranges from 0.1 - 1 %w/w, preferably from 0.1 - 0.5 % w/w, even more preferred from 0,1 - 0,3 % w/w.
  • a thickener is polysaccharides (e.g. xanthan gum, carboxymethylcellulose), anorganic clays (organically modified or unmodified), polycarboxylates, and silicates.
  • the amount of thickeners in the final formulation ranges from 0,1 - 1 ,5 % w/w, preferably from 0,1 - 1 ,0% w/w, even more preferred from 0,2 - 0,5 %.
  • the invention also relates to uses of the microcapsule composition of the invention for protect- ing crop plants and to methods of controlling fungal diseases, which comprise applying the formulations, in diluted or undiluted form, to plants, their environment and/or seeds.
  • compositions of the invention provide for a very good control of fungal pathogens in non- crop areas, especially at high application rates. However, generally no higher application rates are required in comparison with conventional formulations of non-encapsulated pyrimethanil for achieving similar control.
  • compositions of the invention are active against broad-leaved weeds and grass weeds and provide for less damage to the crop plants in comparison with conventional formulations of non-encapsulated pyrimethanil. This effect is par- ticularly observed at low application rates.
  • compositions of the invention provide for long lasting residual activity, which exceeds the residual activity of conventional formulations of non-encapsulated pyrimethanil.
  • the formulations of the invention can additionally be employed in a further number of crop plants to remove undesired plants.
  • Crops which are suitable are, for example, the following: potatoes sugar beets, tobacco, wheat, rye, barley, oats, rice, corn, cotton, soybeans, rape, legumes, sunflowers, coffee or sugar cane; fruits; vines; ornamentals; or vegetables, such as cucumbers, tomatoes, beans or squashes.
  • compositions of the invention as described herein are useful for combating undesired vegetation.
  • the compositions may be applied as such or are preferably applied after dilution with water.
  • a so-called aqueous spray-liquor is prepared by diluting the compositions of the present invention with water, e.g. tap water.
  • the spray-liquors may also comprise further constituents in dissolved, emulsified or suspended form, for example fertilizers, active substances of other groups of herbicidal or growth-regulatory active substances, further active substances, for example ac- tive substances for controlling animal pests or phytopathogenic fungi or bacteria, furthermore mineral salts which are employed for alleviating nutritional and trace element deficiencies, and nonphytotoxic oils or oil concentrates.
  • fertilizers active substances of other groups of herbicidal or growth-regulatory active substances
  • further active substances for example ac- tive substances for controlling animal pests or phytopathogenic fungi or bacteria
  • mineral salts which are employed for alleviating nutritional and trace element deficiencies
  • nonphytotoxic oils or oil concentrates are added to the spray mixture before, during or after dilution of the compositions according to the invention.
  • compositions of the invention can be applied by the pre-emergence or the post-emergence method. If the pyrimethanil is less well tolerated by certain crop plants, application techniques may be employed where the herbicidal compositions are sprayed, with the aid of the spraying apparatus, in such a way that the leaves of the sensitive crop plants ideally do not come into contact with them, while the active substances reach the leaves of undesired plants which grow underneath, or the bare soil surface (post-directed, lay-by).
  • compositions of the invention are applied to such a degree that the application rates of pyrimethanil are from 0.001 to 3.0, preferably from 0.01 to 1.0 kg/ha active substance (a.s.).
  • compositions of the invention can be mixed with a large number of representatives of other groups of fungicidal active substances and applied together with these as defined above in group A) to J).
  • suitable mixing partners are azoxystrobin, coumethoxystrobin, coumoxystrobin, dimoxystrobin, enestroburin, fenaminstrobin, fenoxystrobin/flufenoxystrobin, fluoxastrobin, kres- oxim-methyl, metominostrobin, orysastrobin, picoxystrobin, pyraclostrobin, pyrametostrobin, pyraoxystrobin, trifloxystrobin, 2-[2-(2,5-dimethyl-phenoxymethyl)-phenyl]-3-methoxy-acrylic acid methyl ester and 2-(2-(3-(2,6-dichlorophenyl)-1-methyl-allylideneaminooxymethyl)-phenyl)- 2-methoxyimino-N-methyl-acetamide, the group of carboxamide fungicide selected from be- nodanil, bixafen, boscalid, carboxin, fenfuram, fluo
  • compositions of the present invention are of also possible to use as a tank-mix partner with other formulations.
  • miscibility with mineral salt solutions which are employed for alleviating nutritional and trace element deficiencies. Nonphytotoxic oils and oil concentrates may also be added.
  • Surfactant 1 20% aqueous solution of poly(2-acrylamido-2-methylpropane sulfonic acid) sodium salt with pH 2.5-4;
  • Surfactant 2 15% aqueous solution of sodium dodecyl sulfate
  • Surfactant 3 Naphthalenesulfonic acid formaldehyde condensate Sodiu salt
  • Pre-condensate P1 70% w/w aqueous solution of etherified melamine
  • the resulting aqueous suspension had a solid content of 22.7%.
  • the particle size distribution is given in table 1 .
  • Examples 2 - 4 The microparticles of examples 2 to 4 were prepared by using the following protocol:
  • the amount of free pesticide was determined as followed: First, a 10 w% solution of poloxamer 335 (Pluronic® PE 10500) was prepared which was adjusted to pH 5 with acetic acid. This solution actedas a receiver solution for non- or not well encapsulated pesticide. To 250 ml of thereceiver solution was added 125 mg of the microparticle dispersion and stirred over 4days. After 10min, 5h, 1 d and 3d samples were taken and drawn through a 0.2 ⁇ Teflon filter to remove intact microparticles.
  • poloxamer 335 Pluronic® PE 10500
  • aqueous microparticle suspensions of the present invention are mixed with water and additives while stirring at room temperature.
  • an aqueous CS agrochemical formulation was prepared by mixing an aqueous suspension of microparticles of the invention with an anionic surfactant, a non-ionic surfactant, antifoam, preservative, propylene glycole as antifreeze agent, thickener in such amounts that the final concentration is as follows:
  • anionic surfactant e.g. naphthalenesulfonic acid formaldehyde condensate sodium salt or phenolsulfonic acid urea formaldehyde condensate;
  • non-ionic alkylalkoxylated surfactants e.g. a non-ionic block copolymer of
  • ethyleneoxide and propyleneoxide such as Pluronic® PE 10500;
  • antifoam e.g. a silicon defoamer, such as Wacker Silicon® SRE-PFL;
  • preservatives such as Acticide® MBS
  • 0.1-0.3 wt% thickener such as xanthan gum, e.g. Rhodopol® G;
  • the biological activity of the aqueous microparticle suspensions was evaluated by using a seven day and three day preventive spray application in lambs lettuce infested with Botrytis cinerea (grey mold).
  • Lambs lettuce plants (5 weeks old) were sprayed with the microparticle suspensions (diluted in water) seven days before artificial inoculation with B. cinerea.
  • the concentration of the spray dilution was chosen in a manner that defined use rates of 800, 300 and 135 ppm were applied (in 100 ml spray volume). Four replicates were sprayed per treatment.
  • plants were kept in a greenhouse chamber at 19,5-21 °C, 40-60% RH for seven days.

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Abstract

Microcapsules, comprising solid pyrimethanil, which is surrounded or embedded by an amino- plast polymer, and a composition comprising such microcapsules.

Description

Microcapsule compositions comprising pyrimethanil
Description Background and Summary of the Invention
The present invention relates to microcapsules comprising pyrimethanil, to a method for their preparation to compositions comprising such microcapsules and to the use of these microcapsules and compositions for controlling fungal diseases.
Pyrimethanil is known as a fungicide and described in DD-A 151 404. Pyrimathanil has a lUPAC name N(4,6-dimethylpyrimidin-2-yl)aniline and can be described by the following formula I
Figure imgf000002_0001
WO 2004/004461 describes mixtures of pyrimethanil.
Pyrimethanil has an amino-acid synthesis perturbing effect and inhibits the methionine biosynthesis of fungal pathogens. Thus pyrimethanil prevents diseases caused by a wide spectrum of fungi, including Alternaria spp., Bortrytis cinerea, Cercospora spp., Cladosporium spp., Colleto- trichum spp, M on ilia spp., Mycosphaerella spp., Penicillium spp., and Venturia spp.
Pyrimethanil is a solid fungicide with a melting point which lays at 96,3°C, the density at 1.15 g/cm3 and the vapor pressure at 2.2 mPa at 25°C. Pyrimethanil has a very low solubility in water of 0.12 g/L.
Fungicides, such as pyrimehtanil, are normally applied in the form of dilute aqueous spray liquors, which are prepared by diluting a concentrate formulation with water. For this purpose, pesticide compounds may be formulated in solid forms, such as wettable powders (WP) and water- dispersible granules (WG), as well as in liquid forms, such as emulsions, emulsifiable concentrates (EC), suspoemulsions (SE) or suspension concentrates (SC). It is of particular importance, that the formulations can be easily diluted with water and that the dilution remains stable for a certain time without separation of the active ingredient, as this may cause clogging of the spraying nozzels. For ecological reasons it is preferred that the formulation does not con- tain large amounts of organic solvents. Thus water based formulations (SC) and dry formulations are preferred.
Pyrimethanil is typically formulated as SC formulation. The known formulations of pyrimethanil have a disadvantage compared with the formulation of other fungicides. This is due to the high volatility (vapour pressure) of pyrimethanil. A lot of a.i. does not maintain on the leaf after spray- ing and evapourates into the atmosphere. This leads to the loss of efficacy of such formulations. Therefore it is an object of the present invention to provide a formulation of pyrimethanil in which the high volatility of a.i. can be reduced and thus the efficacy of the formulation will be increased.
It was surprisingly found that microcapsules of solid pyrimethanil surrounded or embedded by an aminoplast polymer provide for reduced volatility of pyrimethanil.
Therefore, a first aspect of the invention relates to microcapsules, comprising solid pyrimethanil, which is surrounded or embedded by an aminoplast polymer, and a second aspect of the invention relates to a composition comprising such microcapsules.
The microcapsules according to the invention have the advantage that the aminoplast polymer reduces volatility of pyrimethanil. At the same time aminoplast polymer according to the invention allows the controlled release of pyrimethanil whereby the a.i. will be controlled absorb by the crop and will not evaporate after spraying into the atmosphere. Thus it is achieved that the microcapsules of the present invention provide a higher fungicidal activity as compared to regu- lar SC formulations.
In the microcapsules according to the present invention, pyrimethanil is less prone to degradation. Thus, microcapsules of the present invention provide for both high physical and chemical stability over prolonged storage periods while maintaining the biological efficacy of pyrimethanil. Moreover, microcapsules of the present invention can be easily formulated.
It is principally known to provide pesticidally active compounds in the form of micrcocapsule formulations (see H. Mollet, A. Grubenmann "Formulation Technology" 1 st ed., Wiley-VCH Ver- lag GmbH, Weinheim 2001 , Chapter 6.4 and Chapter 14.2.2). Microencapsulation can be principally achieved by coacervation techniques, spray drying, fluidized-bed coating, electrostatic microencapsulation or in-situ polymerization. These techniques provide active compound parti- cles, wherein the active compound is surrounded by a polymeric wall material.
The most common method for microencapsulation of agrochemical materials is the interfacial polymerization. In this process, a first reactant, e.g. a polyfunctional isocanate or acid chloride, is dissolved in the liquid active ingredient or a solution thereof, which is then dispersed in water and subjected to polymerization by addition of a polyfunctional compound having a complemen- tary reactivity with regard to the first reactant, e.g. an diamine or diol (see H. Mollet, A. Grubenmann, loc. cit. page 394 and US 4,107,292, US 5,705,174, US 5,910,314, WO 0027519, EP 8207, US 2004/1 15280). The polymerization occurring at the interface between the active substance and the aqueous phase completely encloses the fine droplets of active substance with a thin membrane of polyurea or polyamide.
A further in-situ polymerization technique includes microencapsulation by using aminoplasts such as melamine formaldehyde resins (MF resisn) or urea formaldehyde resins (UF resins) or melamine formaldehyde urea resins (MUF resins). The aminoplast resins are used in the form of their prepolymers or pre-condensates, which are added to an aqueous suspension of the material to be encepsulated and cured by heating and/or altering the pH of the reaction mixture to effect polymerization of the prepolymers. Thereby, an aqueous suspensions of the microcapsules are obtained, where the particles of the encapsulated material are surrounded by or em- bedded in an aminoplast polymer. A survey of this method is given in Acta Polymerica 40, (1989) No. 5, pp. 325-331 and C.A. Finch, R. Bodmeier, Microencapsulation, Ullmann's Encyclopedia of Industrial Chemistry, 6th Edition, 2001 Electronic Release).
Microencapsulation of pesticides using in-situ polymerization of aminoplasts pre-condensates have been described several times. For example, US 4,557,755 describes the microencapsulation of water-insoluble pesticides by polymerizing an aminoplast pre-condensate, such as a melamine formaldehyde or melamine urea formaldehyde resin in an aqueous suspension of the pesticide compound in the presence of a cationic urea resin. The method is suggested for certain insecticides and fungicides.
US 5,462,915 describes an improved process for micro-encapsulation of water-insoluble pesticides, which comprises adding to a suspension of the pesticide a liquid aminoplast prepolymer and curing the prepolymer at temperatures of above 100°C. The method was applied for microencapsulation of water-insoluble salts of dicamba. A similar process is known from WO
00/27519, which was applied for microencapsulation of carbofuran.
WO 96/03041 describes a microcapsule composition of pesticides, wherein the microcapsules have an outer aminoplast layer and an inner wax coating deposited around pesticide compound.
Modern techniques of microencapsulation include the radical suspension polymerization of water-insoluble acrylate monomers with (meth)acrylic acid and optionally polyfunctional monomers in the presence of an o/w-emulsion of the pesticide compound (see e.g. WO 2012/101070) or the radical emulsion polymerization of an aqueous monomer emulsions, wherein the pesticide is dissolved or suspended in the monomer droplets (see e.g. WO 2005/102044, WO2006/094792, WO 2006/094978).
Although microencapsulation may improve the acute toxicity of a pesticide or reduce degrada- tion, it is often difficult to achieve. In particular, aggregation of the pesticide particles during or after encapsulation is the main problem, if one encapsulation method, which may work for a particular pesticide compound, does not necessarily work for another pesticide compound. When trying to encapsulate a solid material in an aqueous suspension of the solid material by an in-situ-polymerization technique, the solid material tends to agglomerate thereby forming large particles of active ingredient particles, which are embedded in the polymer matrix. A thus obtained suspension is usually no longer suitable for agricultural use.
Therefore it is a further object of the present invention to provide a simple method for preparation of the microcapsules according to the invention and the compositions comprising the inventive microcapsules.
It was also surprisingly found that solid pyrimethanil can be efficiently micro-encapsulated by using aminoplast pre-condensates and performing the process described hereinafter.
Therefore, a second aspect of the present invention relates to a process for preparing
(i) providing an aqueous suspension or dispersion of pyrimethanil particles;
(ii) adding an aminoplast pre-condensate to the aqueous suspension,
(iii) initiating the polycondensation of the amoniplast pre-condensate,
(iv) stabilization of the capsule suspension by formulation This process results in a stable aqueous suspension, wherein pyrimethanil is present in the form of microcapsules, which comprise solid pyrimethanil, which is surrounded or embedded by an aminoplast polymer. From this, the microcapsules can be isolated, if necessary. Surprisingly, this process does not result in significant agglomeration of the pyrimethanil particles, as was observed for other in-situ polymerization techniques.
Detailed Description of Invention
In the microcapsules according to the invention solid pyrimethanil is surrounded or embedded by an aminoplast polymer. In the microcapsules solid pyrimethanil forms the core material which is surrounded or embedded by at least one aminoplast polymer. In this context, it has to be understood that the aminoplast polymers may form a regular or irregular shell which surrounds the core material. It is not necessary that the aminoplast polymer forms a completely closed shell. Frequently, however, the shell will completely surround the core material like a membrane, thereby forming a barrier between the core material and the surrounding material.
The microcapsules according to the invention build so-called particles with "domain structure" comprising between 3 and 10 crystals of pyrimethanil surrounded or embedded by the aminoplast polymer.
Aminoplast polymers, which are also termed amino resins, amino condensation resins or amido resins are polycondensation products of one or more aldehydes, such as formaldehyde, glyoxal, propanal, or glutaraldehyde, with one or more amino compounds having usually at least 2 primary amino groups, such as urea, thiourea, melamine, which may be wholly or partially etheri- fied, cyanoguanamine (= dicyandiamide) and benzoguanamine. Examples of aminoplast polymers are polycondensates of melamine and formaldehyde (melamine-formaldehyde resins or MF resins), including resins derived from wholly or partially etherified melamine-formaldehyde condensates, urea-formaldehyde resins (UF resins), thiourea-formaldehyde resins (TUF resins), polycondensates of melamine, urea and formaldehyde (MUF resins), including resins derived from wholly or partially etherified melamine-urea-formaldehyde condensates, polycondensates of melamine, thiourea and formaldehyde (MTUF resins, including resins derived from wholly or partially etherified melamine-thiourea-formaldehyde condensates, urea-glutaraldehyde resins, benzoguanamine-formaldehyde polycondensates, dicyandiamide formaldehyde polycondensates and urea-glyoxal polycondensates. Suitable aminoplast polymers for microencapsulation are known and can be found, inter alia, in Kirk-Othmer, Encyclopedia of Chemical Technology, 3rd edition, Vol. 2, pp. 440-469, the prior art cited in the introductory part, US 4,918,317, EP 26914, EP 218887, EP 319337, EP 383,337, EP 415273, DE 19833347, DE 198351 14 and WO 01/51 197.
According to one embodiment of the invention the aminoplast polymer is selected form the group consisting of melamine formaldehyde resins (MF) and/or urea formaldehyde resins (UF) and/or melamine urea formaldehyde resins (MUF).
In UF and TUF resins, the molar ratios of urea or thiourea to formaldehyde are generally in the range from 1 : 0.8 to 1 : 4, in particular from 1 : 1.5 to 1 : 4, especially from 1 :2 to 1 : 3.5. If glu- taraldehyde is used instead of formaldehyde, the molar ratios of urea or thiourea to glutaralde- hyde may in particular be in the range from 1 : 1.2 to 1 : 3, especially in the range from 1 : 1.5 to 1 : 2.5.
In MF and MUF resins, the molar ratios of melamine to formaldehyde are generally in the range from 1 : 1.5 to 1 : 10, in particular from 1 : 3 to 1 : 8 preferably 1 : 4 to 1 :6.
In MUF and MTUF resins, the molar ratios of melamine + urea or thiourea to formaldehyde are generally in the range from 1 : 0.8 to 1 : 9, in particular from 1 : 2 to 1 : 8 preferably 1 : 3 to 1 :6. The molar ratio of urea or thiourea to melamine may be in the range from 50 : 1 to 1 : 100 and in particular from 30 : 1 to 1 : 30.
In the preparation of the aforementioned aminoplast resins, the pre-condensates may be used in the form of etherified pre-condensates of amino compound and aldehyde. In these etherified pre-condensates the methylol groups formed by the reaction of the amino groups with formaldehyde with an alkanol or an alkandiol, in particular with a Ci-C4-alkanol such as methanol, eth- anol, n-propanol or n-butano, in particular methanol, or a C2-C4-alkandiol such as ethylene gly- col. The degree of etherification of these resins can be adjusted by the molar ratio of amino groups to alkanol which is typically in the range from 10 : 1 to 1 : 10, preferably in the range from 2 : 1 to 1 : 5.
The aminoplast polymers, which surround or embed the solid pyrimethanil, are most preferably selected from the group consisting of melamine-formaldehyde resins, including melamine- formaldehyde resins derived from wholly or partially etherified melamine-formaldehyde condensates, and urea-formaldehyde resins and mixtures thereof. Especially, the aminoplast polymers, which surrounds or embeds the solid pyrimethanil, is a melamine-formaldehyde resin, derived from wholly or partially etherified melamine-formaldehyde condensates, which may contain small amount, e.g. 1 to 20 mol.-%, based on melamine, of urea.
In the microcapsules of the invention, the amount of aminoplast polymers, which surround or embed the solid pyrimethanil, is preferably from 1 to 40 % by weight, in particular from 1 to 35 % by weight and especially from 5 to 25 % by weight, based on total capsule weight. According to one most preferred embodiment the amount aminoplast polymers, which surround or embed the solid pyrimethanil, is 10 to 20 % by weight, based on total capsule weight. The encapsulat- ing polymers of the microcapsules of the invention, which surround or embed the solid pyrimethanil, may comprise further water-insoluble polymers. However, the amount of such polymers will generally not exceed 20 % of the total amount of encapsulating polymers, and will preferably not exceed 10 % by weight of the total amount of encapsulating polymers.
The solid pyrimethanil, which is surrounded or embedded by at least one aminoplast polymer, may be any known form of solid pyrimethanil, including amorphous pyrimethanil and in particular crystalline pyrimethanil, e.g. the crystalline anhydrate of pyrimethanil as described in WO 08/043835 or a crystalline hydrate of pyrimethanil as described in WO 08/043836.
In addition to the solid pyrimethanil, the core material of the microcapsules may contain an oil, e.g. a hydrocarbon solvent such a an aromatic, paraffinic or isoparaffinic hydrocarbon, having preferably a boiling point above 100°C, a vegetable oil such as corn oil, rapeseed oil, or a fatty acid ester such as Ci-Cio-alkylester of a Cio-C22-fatty acid, in particular methyl- or ethyl esters of vegetable oils such as rapeseed oil methyl ester or corn oil methyl ester. In a particular embod- iment, the core material does not contain an oil as defined herein or less than 10 % by weight, based on the weight of the core material, of an oil.
In addition to the solid pyrimethanil, the core material of the microcapsules may further contain a further pesticide compound, in particular a pesticide compound or a safener, having preferably a reduced water solubility, which generally does not exceed 10 g/l, in particular 5 g/l or even 1 g/l at 25°C (deionised water). In particular, solid pyrimethanil makes up at least 80 %, in particular at least 90 % of the pesticides contained in the microcapsules.
The term "pesticide" refers to at least one pesticide selected from the group of fungicides and insecticides. Also mixtures of pesticides from two or more of the aforementioned classes may be used. An expert is familiar with such pesticides, which might be found in the Pesticide Manual, 14th Ed. (2006), The British Crop Protection Council, London or e-Pesticide Manual V5.1 , ISBN 978 1 901396 84 3 among other publications.
Suitable fungicides are
A) Respiration inhibitors
- Inhibitors of complex III at Q0 site: the strobilurines azoxystrobin, coumethoxystrobin,
coumoxystrobin, dimoxystrobin, enestroburin, fenaminstrobin, fenoxy- strobin/flufenoxystrobin, fluoxastrobin, kresoxim-methyl, metominostrobin, orysastrobin, picoxystrobin, pyraclostrobin, pyrametostrobin, pyraoxystrobin, trifloxystrobin, 2-[2-(2,5- dimethyl-phenoxymethyl)-phenyl]-3-methoxy-acrylic acid methyl ester and 2-(2-(3-(2,6-di- chlorophenyl)-1-methyl-allylideneaminooxymethyl)-phenyl)-2-methoxyimino-N-methyl- acetamide; and pyribencarb, triclopyricarb/chlorodincarb, famoxadone, fenamidone;
- inhibitors of complex III at Q, site: cyazofamid, amisulbrom, [(3S,6S,7R,8R)-8-benzyl-3-[(3- acetoxy-4-methoxy-pyridine-2-carbonyl)amino]-6-methyl-4,9-dioxo-1 ,5-dioxonan-7-yl] 2-methylpropanoate, [(3S,6S,7R,8R)-8-benzyl-3-[[3-(acetoxymethoxy)-4-methoxy-pyridine- 2-carbonyl]amino]-6-methyl-4,9-dioxo-1 ,5-dioxonan-7-yl] 2-methylpropanoate,
[(3S,6S,7R,8R)-8-benzyl-3-[(3-isobutoxycarbonyloxy-4-methoxy-pyridine-2-carbonyl)amino]- 6-methyl-4,9-dioxo-1 ,5-dioxonan-7-yl] 2-methylpropanoate, [(3S,6S,7R,8R)-8-benzyl-3-[[3- (1 ,3-benzodioxol-5-ylmethoxy)-4-methoxy-pyridine-2-carbonyl]amino]-6-methyl-4,9-dioxo- 1 ,5-dioxonan-7-yl] 2-methylpropanoate;
- inhibitors of complex II (e. g. carboxamides): benodanil, bixafen, boscalid, carboxin, fen- furam, fluopyram, flutolanil, fluxapyroxad, furametpyr, isopyrazam, mepronil, oxycarboxin, penflufen, penthiopyrad, sedaxane, tecloftalam, thifluzamide, N-(4'- trifluoromethylthiobiphenyl-2-yl)-3-difluoromethyl-1-methyl-1 H-pyrazole-4-carboxamide, N-(2- (1 ,3,3-trimethyl-butyl)-phenyl)-1 ,3-dimethyl-5-fluoro-1 H-pyrazole-4-carboxamide, N-[9- (dichloromethylene)-l ,2,3,4-tetrahydro-1 ,4-methanonaphthalen-5-yl]-3-(difluoromethyl)-1 - methyl-1 H-pyrazole-4-carboxamide;
- other respiration inhibitors (e.g. complex I, uncouplers): diflumetorim, (5,8-difluoroquinazolin- 4-yl)-{2-[2-fluoro-4-(4-trifluoromethylpyridin-2-yloxy)-phenyl]-ethyl}-amine; nitrophenyl deri- vates: binapacryl, dinobuton, dinocap, fluazinam; ferimzone; organometal compounds: ame- toctradin; and silthiofam;
B) Sterol biosynthesis inhibitors (SBI fungicides) - C14 demethylase inhibitors (DMI fungicides): triazoles: azaconazole, bitertanol, bromucona- zole, cyproconazole, difenoconazole, diniconazole, diniconazole-M, epoxiconazole, fenbu- conazole, fluquinconazole, flusilazole, flutriafol, hexaconazole, imibenconazole, ipconazole, metconazole, myclobutanil, oxpoconazole, paclobutrazole, penconazole, propiconazole, prothioconazole, simeconazole, tebuconazole, tetraconazole, triadimefon, triadimenol, triti- conazole, uniconazole; imidazoles: imazalil, pefurazoate, prochloraz, triflumizol; pyrimidines, pyridines and piperazines: fenarimol, nuarimol, pyrifenox, triforine;
- Delta 14-reductase inhibitors: aldimorph, dodemorph, dodemorph-acetate, fenpropimorph, tridemorph, fenpropidin, piperalin, spiroxamine;
- Inhibitors of 3-keto reductase: fenhexamid;
C) Nucleic acid synthesis inhibitors
- phenylamides or acyl amino acid fungicides: benalaxyl, benalaxyl-M, kiralaxyl, metalaxyl, metalaxyl-M (mefenoxam), ofurace, oxadixyl;
- others: hymexazole, octhilinone, oxolinic acid, bupirimate, 5-fluorocytosine, 5-fluoro-2-(p- tolylmethoxy)pyrimidin-4-amine, 5-fluoro-2-(4-fluorophenylmethoxy)pyrimidin-4-amine;
D) Inhibitors of cell division and cytoskeleton
- tubulin inhibitors, such as benzimidazoles, thiophanates: benomyl, carbendazim, fuber- idazole, thiabendazole, thiophanate-methyl; triazolopyrimidines: 5-chloro-7-(4-methyl- piperidin-1-yl)-6-(2,4,6-trifluorophenyl)-[1 ,2,4]triazolo[1 ,5-a]pyrimidine
- other cell division inhibitors: diethofencarb, ethaboxam, pencycuron, fluopicolide, zoxamide, metrafenone, pyriofenone;
E) Inhibitors of amino acid and protein synthesis
- methionine synthesis inhibitors (anilino-pyrimidines): cyprodinil, mepanipyrim, pyrimethanil;
- protein synthesis inhibitors: blasticidin-S, kasugamycin, kasugamycin hydrochloride-hydrate, mildiomycin, streptomycin, oxytetracyclin, polyoxine, validamycin A;
F) Signal transduction inhibitors
- MAP / histidine kinase inhibitors: fluoroimid, iprodione, procymidone, vinclozolin, fenpiclonil, fludioxonil;
- G protein inhibitors: quinoxyfen;
G) Lipid and membrane synthesis inhibitors
- Phospholipid biosynthesis inhibitors: edifenphos, iprobenfos, pyrazophos, isoprothiolane;
- lipid peroxidation: dicloran, quintozene, tecnazene, tolclofos-methyl, biphenyl, chloroneb, etridiazole;
- phospholipid biosynthesis and cell wall deposition: dimethomorph, flumorph, mandipropa- mid, pyrimorph, benthiavalicarb, iprovalicarb, valifenalate and N-(1-(1-(4-cyano-phenyl)- ethanesulfonyl)-but-2-yl) carbamic acid-(4-fluorophenyl) ester;
- compounds affecting cell membrane permeability and fatty acides: propamocarb, propamo- carb-hydrochlorid
H) Inhibitors with Multi Site Action
- inorganic active substances:
- organochlorine compounds (e.g. phthalimides, sulfamides, chloronitriles): anilazine, , di- chlofluanid, dichlorophen, flusulfamide, hexachlorobenzene, pentachlorphenole and its salts, phthalide, tolylfluanid, N-(4-chloro-2-nitro-phenyl)-N-ethyl-4-methyl-benzenesulfonamide;
- guanidines and others: guanidine, dodine, , guazatine, guazatine-acetate, iminoctadine, iminoctadine-triacetate, iminoctadine-tris(albesilate),;
I) Cell wall synthesis inhibitors
- inhibitors of glucan synthesis: validamycin, polyoxin B; melanin synthesis inhibitors: pyroqui- lon, tricyclazole, carpropamid, dicyclomet, fenoxanil;
J) Plant defence inducers
- acibenzolar-S-methyl, probenazole, isotianil, tiadinil, prohexadione-calcium; phosphonates:
K) Unknown mode of action
- , chinomethionat, cyflufenamid, cymoxanil, , debacarb, diclomezine, difenzoquat, difen- zoquat-methylsulfate, , fenpyrazamine, flumetover, flusulfamide, flutianil, methasulfocarb, ni- trapyrin, nitrothal-isopropyl, , proquinazid, tebufloquin, tecloftalam, triazoxide, 2-butoxy-6- iodo-3-propylchromen-4-one, N-(cyclopropylmethoxyimino-(6-difluoro-methoxy-2,3-difluoro- phenyl)-methyl)-2-phenyl acetamide, N'-(4-(4-chloro-3-trifluoromethyl-phenoxy)-2,5-dimethyl- phenyl)-N-ethyl-N-methyl formamidine, N'-(4-(4-fluoro-3-trifluoromethyl-phenoxy)-2,5- dimethyl-phenyl)-N-ethyl-N-methyl formamidine, N'-(2-methyl-5-trifluoromethyl-4-(3-trimethyl- silanyl-propoxy)-phenyl)-N-ethyl-N-methyl formamidine, N'-(5-difluoromethyl-2-methyl-4-(3- trimethylsilanyl-propoxy)-phenyl)-N-ethyl-N-methyl formamidine, 2-{1-[2-(5-methyl-3- trifluoromethyl-pyrazole-1 -yl)-acetyl]-piperidin-4-yl}-thiazole-4-carboxylic acid methyl- (1 ,2,3,4-tetrahydro-naphthalen-1 -yl)-amide, 2-{1-[2-(5-methyl-3-trifluoromethyl-pyrazole-1 - yl)-acetyl]-piperidin-4-yl}-thiazole-4-carboxylic acid methyl-(R)-1 ,2,3,4-tetrahydro-naphthalen- 1 -yl-amide,
1 - [4-[4-[5-(2,6-difluorophenyl)-4,5-dihydro-3-isoxazolyl]-2-thiazolyl]-1 -piperidinyl]-
2- [5-methyl-3-(trifluoromethyl)-1 H-pyrazol-1-yl]ethanone, methoxy-acetic acid
6-tert-butyl-8-fluoro-2,3-dimethyl-quinolin-4-yl ester, NMethyl-2-{1-[(5-methyl-3-trifluoro- methyl-1 H-pyrazol-1 -yl)-acetyl]-piperidin-4-yl}-/V-[(1 R)-1 ,2,3,4-tetrahydronaphthalen-1-yl]-4- thiazolecarboxamide, 3-[5-(4-methylphenyl)-2,3-dimethyl-isoxazolidin-3-yl]-pyridine, 3-[5-(4- chloro-phenyl)-2,3-dimethyl-isoxazolidin-3-yl]-pyridine (pyrisoxazole), N-(6-methoxy-pyridin-
3- yl) cyclopropanecarboxylic acid amide, 5-chloro-1 -(4,6-dimethoxy-pyrimidin-2-yl)-2-methyl- 1 H-benzoimidazole,
2-(4-chloro-phenyl)-N-[4-(3,4-dimethoxy-phenyl)-isoxazol-5-yl]-2-prop-2-ynyloxy-acetamide;
L) ;
Suitable Insecticides are
organo(thio)phosphates: acephate, azamethiphos, azinphos-methyl, chlorpyrifos, chlorpyrifos-methyl, chlorfenvinphos, diazinon, dichlorvos, dicrotophos, dimethoate, disulfoton, ethion, fenitrothion, fenthion, isoxathion, malathion, methamidophos, methidathion, methyl- parathion, mevinphos, monocrotophos, oxydemeton-methyl, paraoxon, parathion, phenthoate, phosalone, phosmet, phosphamidon, phorate, phoxim, pirimiphos-methyl, profenofos, prothi- ofos, sulprophos, tetrachlorvinphos, terbufos, triazophos, trichlorfon;
- carbamates: alanycarb, aldicarb, bendiocarb, benfuracarb, carbaryl, carbofuran, carbosul- fan, fenoxycarb, furathiocarb, methiocarb, methomyl, oxamyl, pirimicarb, propoxur, thiodi- carb, triazamate;
- pyrethroids: allethrin, bifenthrin, cyfluthrin, cyhalothrin, cyphenothrin, cypermethrin, alpha- cypermethrin, beta-cypermethrin, zeta-cypermethrin, deltamethrin, esfenvalerate, etofenprox, fenpropathrin, fenvalerate, imiprothrin, lambda-cyhalothrin, permethrin, prallethrin, pyrethrin I and II, resmethrin, silafluofen, tau-fluvalinate, tefluthrin, tetramethrin, tralomethrin, transfluthrin, profluthrin, dimefluthrin, flucythirnate;
- insect growth regulators: a) chitin synthesis inhibitors: benzoylureas: chlorfluazuron, cy- ramazin, diflubenzuron, flucycloxuron, flufenoxuron, hexaflumuron, lufenuron, novaluron, teflubenzuron, triflumuron; buprofezin, diofenolan, hexythiazox, etoxazole, clofentazine; b) ecdysone antagonists: halofenozide, methoxyfenozide, tebufenozide, azadirachtin; c) juve- noids: pyriproxyfen, methoprene, fenoxycarb; d) lipid biosynthesis inhibitors: spirodiclofen, spiromesifen, spirotetramat;
- nicotinic receptor agonists/antagonists compounds: clothianidin, dinotefuran, imidacloprid, thiamethoxam, nitenpyram, acetamiprid, thiacloprid, 1 -(2-chloro-thiazol-5-ylmethyl)-2- nitrimino-3,5-dimethyl-[1 ,3,5]triazinane;
- GABA antagonist compounds: endosulfan, ethiprole, fipronil, vaniliprole, pyrafluprole,
pyriprole, 5-amino-1-(2,6-dichloro-4-methyl-phenyl)-4-sulfinamoyl-1 H-pyrazole-3-carbothioic acid amide;
- macrocyclic lactone insecticides: abamectin, emamectin, milbemectin, lepimectin, spinosad, spinetoram;
- mitochondrial electron transport inhibitor (METI) I acaricides: fenazaquin, pyridaben,
tebufenpyrad, tolfenpyrad, flufenerim;
- METI II and III compounds: acequinocyl, fluacyprim, hydramethylnon;
- Uncouplers: chlorfenapyr;
- oxidative phosphorylation inhibitors: cyhexatin, diafenthiuron, fenbutatin oxide, propargite;
- moulting disruptor compounds: cryomazine;
- mixed function oxidase inhibitors: piperonyl butoxide;
- sodium channel blockers: indoxacarb, metaflumizone;
- others: benclothiaz, bifenazate, cartap, flonicamid, pyridalyl, pymetrozine, sulfur, thiocyclam, flubendiamide, chlorantraniliprole, cyazypyr (HGW86), cyenopyrafen, flupyrazofos, cyflumetofen, amidoflumet, imicyafos, bistrifluron, and pyrifluquinazon.
The microcapsules of the present invention are discrete particles having usually a particle size of less than 50 μηη. Preferably, the particle size of the microcapsule particles, i.e. their diameter, will in general not exceed 40 μηι, preferably not exceed 35 μηι and in particular not exceed 30 μηι. The particle size given is the so called dgo-value, which has to be understood as the value that is not exceeded by the diameters of at least 90 % by weight of the microcapsule particles, the microcapsule particles have an average particle diameter, herein also termed dso-value, ranging from 1 to 25 μηη, in particular from 1 .5 to 20 μηη, especially from 1 to 10 μηη. The dso- value is defined as the value that is above the diameters of 50 % by weight of the particles and below the diameters of 50 % by weight of the particles. The dgo value as well as the dso value can be calculated from the particle size distribution of the microcapsule particles. The particle size distribution of the microcapsule particles (i.e. the diameters) can be determined by conven- tional methods such as dynamic or static light-scattering of an aqueous dispersion of the microcapsule composition, e.g. at 25 °C and a concentration in the range of 0.1 to 1 % by weight.
Further aspect of the invention relates to a composition comprises the microcapsules as defined above.
The composition according to the invention comprises further at least one anionic polymeric surfactant having a plurality of sulfate or sulfonate groups. In a preferred embodiment of the invention, the microcapsules contain at least one anionic polymeric surface-active substance A, hereinafter anionic polymeric surfactant, which contains a plurality of anionic groups, such as carboxylate groups, sulfonate groups, phosphonate groups, sulfate groups and/or phosphate groups. Preferably, the anionic groups are selected from sulfonate groups. Examples for poly- meric surfactant A are the surfactants of the following groups A1 to A3, including the salts thereof:
A.1 lignin based sulfonic acids, such as lignosulfonic acid, ethoxylated ignosulfonic acid or oxidized lignins;
A.2 arylsulfonic acid formaldehyde condensates and arylsulfonic acid formaldehyde urea con- densates, such as naphthalene sulfonic acid formaldehyde condensates, phenol sulfonic acid formaldehyde condensates, cresol sulfonic acid formaldehyde condensates etc,
A.3 and homo- or copolymers of monoethylenically unsaturated monomers M1 having a sulfonic acid group optionally with one or more comonomers M2 different from monomers M1.
The anionic groups in these anionic polymeric surfactants may be partially or fully neutralized. Suitable counter ions are alkalimetal ions such as sodium, potassium, earthalkaline ions such as magnesium or calcium, and ammonium. In case of anionic polymeric surfactants having a sulfonate group, the anionic groups are preferably at least partly neutralized.
Preferably, the polymeric surfactant A.3 are in particular selected from homo- or copolymers of i) at least one monoethylenically unsaturated monomer M1 having a sulfonic acid group, such as vinylsulfonic acid, allylsulfonic acid, styrene sulfonic acid, vinyltoluene sulfonic acid, (meth)acrylate monomers having a sulfonic acid group, such as 2-acryloxyethylsulfonic acid, 2-acryloxypropylsulfonic or 4-acryloxybutylsulfonic acid, and (meth)acrylamide mon- omer having a sulfonic acid group, such as 2-acrylamidoethylsulfonic acid, 2- acrylamidopropylsulfonic acid or 2-acrylamido-2-methylpropane sulfonic acid ii) optionally with one or more monoethylenically unsaturated comonomers M2 different from monomers M1 , such as styrene, C1-C4-alkylacrylat.es, C1-C4-alkylmethacrylat.es, acryla- mide, methacrylamide, acrylic acid, methacrylic acid, C1-C4-alkylacrylat.es, C1-C4- alkylmethacrylates.
In particular the polymeric surfactant A comprises or is selected from homo- or copolymers of i) monomers M1 , which are selected from (meth)acrylate monomers having a sulfonic acid group, such as 2-acryloxyethylsulfonic acid, 2-acryloxypropylsulfonic or 4- acryloxybutylsulfonic acid, and (meth)acrylamide monomer having a sulfonic acid group, such as 2-acrylamidoethylsulfonic acid, 2-acrylamidopropylsulfonic acid or 2-acrylamido- 2-methylpropane sulfonic acid, .
ii) optionally with one or more monoethylenically unsaturated comonomers M2 different from monomers M1 , such as styrene, C1-C4-alkylacrylat.es, C1-C4-alkylmethacrylat.es, acryla- mide, methacrylamide, acrylic acid, methacrylic acid, C1-C4-alkylacrylat.es, C1-C4- alkylmethacrylates.
Especially, the polymeric surfactant A comprises or is selected from homo- or copolymers of i) monomers M1 , which is 2-acrylamido-2-methylpropane sulfonic acid, .
ii) optionally with one or more monoethylenically unsaturated comonomers M2 different from monomers M1 , such as styrene, C1-C4-alkylacrylat.es, C1-C4-alkylmethacrylat.es, acryla- mide, methacrylamide, acrylic acid, methacrylic acid, C1-C4-alkylacrylat.es, C1-C4- alkylmethacrylates.
In these preferred, particular preferred or especially preferred polymeric surfactants A.3, the amount of monomers M1 is preferably at least 50 % by weight, based on the total amount of monomers forming the polymeric surfactant. Even more preferred are polymeric surfactants A, which are homo- or copolymers of monomers M1 , wherein the amount of monomers M1 is at least 90 % by weight, based on the total amount of monomers forming the polymeric surfactant. These polymers are known, e.g. from commercially available under the tradenames Lupasol S Lupasol PA 140 (from BASF SE), and Wettol D1.
The amount of the anionic polymeric surfactant A in the composition is preferably from 0.1 to 50 % by weight, in particular from 3 to 40 % by weight and most preferred from 5 to 30 % by weight, based on the total amount of pyrimethanil and aminoplast polymer.
The compositions according to the invention may also contain a nonionic surface-active compound (nonionic surfactant) which provide for the stabilization of an aqueous formulation comprising the microcapsules. Suitable anionic surface-active compounds B are surfactants having one anionic group, which is selected from phosphate or phosphonate groups and sulfate or sulfonate groups, the latter compounds being preferred. These surfactants B will usually be included into the microcapsule composition in the form of their salts, in particular the sodium, potassium or ammonium salts. Examples of anionic surfactants B include the salts of alkylsulfonates, alkylsulfates, alkylphosphates, semi-esters of alkoxylated alkanols with sulfuric acid or phos- phoric acid, alkylarylsulfonates, alkylarylphosphates, semi-esters of alkoxylated alkylphenols with sulfuric acid or phosphoric acid and semi-esters of alkoxylated mono-, di- or tristyrylphenols with sulfuric acid or phosphoric acid. Amongst these anionic surfactants B, those of the formula I are preferred:
R-(0-A)m-0-X
wherein
R is a hydrocarbon radical having from 8 to 40 carbon atoms and preferably from 12 to 30 carbon atoms and optionally one oxygen atom;
A is independently from one another 1 ,2-ethylene, 1 ,2-propylene or 1 ,3-propylene, especial- ly 1 ,2-ethylene;
m is from 0 to 50, preferably from 0 to 30 and especially preferred from 0 to 20; and
X is SO3M or PO3M2 with M being selected from H, alkaline metal ions, such as K and Na, alkaline earth metal ions, such as ½ Ca and ½ Mg and ammonium. Preferably, M is an alkaline metal ion and especially sodium.
Examples of suitable hydrocarbon radicals R having from 8 to 40 carbon atoms are alkyl having from 8 to 40 and preferably from 12 to 30 carbon atoms, phenyl, which may be substituted with one or two alkyl radicals having from 4 to 20 carbon atoms, phenyl, which is substituted with a phenoxy radical, wherein phenyl and/or phenoxy may contain an alkyl radical having from 4 to 20 carbon atoms, tristyrylphenyl radical etc. In a preferred embodiment of the present invention the radical R in formula I is a tristyrylphenyl radical.
Preference is given to anionic surfactants B, which are of the formula (I), wherein R, m and X have the following meanings:
R is alkyl having from 8 to 30, in particular from 10 to 20 carbon atoms,
m is 0,
X is is SO3M with m being selected from alkaline metal ions, such as K and Na, alkaline earth metal ions, such as ½ Ca and ½ Mg and ammonium. Preferably, M is an alkaline metal and especially sodium.
If present, the amount of anionic surfactant B, in particular the surface-active compound of the formula I, is preferably from 0.01 to 1 % by weight, in particular from 0.1 to 0.5 % by weight, based on the total amount of the aqueous suspension. If present, the amount of anionic surfactant B, in particular the surface-active compound of the formula I, is preferably chosen such that the weight ratio of anionic polymeric surfactant A to anionic surfactant B is from 1 : 1 to 20 : 1 in particular from 2 : 1 to 10 : 1 .
In a preferred embodiment the suspension comprises at least one anionic emulsifier in addition to the polymeric surfactant. In particular groups of embodiments, the microcapsule composition is in the form of an aqueous suspension. Such a suspension contains the microcapsules of solid pyrimethanil as a disperse phase, and an aqueous medium as the continuous phase. The aqueous suspension may be obtained by the process for preparing the microcapsule composi- tion as described herein. It may also be obtained by re-dispersing a solid microcapsule composition as described herein in an aqueous medium.
The term "aqueous medium" stands for the liquid phase of the composition and comprises an aqueous solvent and optionally compounds dissolved therein, e.g. surfactants as mentioned above, and if present, conventional one or more conventional formulation additives, such as thickeners or biocides. The aqueous solvent of the aqueous suspension is either water or a mixture thereof with a water-miscible organic solvent, such as Ci-C4-alkanols, e.g. methanol, etha- nol, n-propanol, isopropanol, n-butanol, 2-butanol, isobutanol, or tert. butanol, C2-Cs-alkanediols and Cs-Cs-alkanetriols, preferably from the group consisting of ethylene glycol, 1 ,2-propanediol, 1 ,3-propanediol, glycerol and 1 ,4-butanediol. Generally, the amount of water in the aqueous solvent is at least 50 % by weight, in particular at least 80 % by weight or at least 90 % by weight, based on the aqueous solvent. The aqueous solvent may consist mainly of water, i.e. water makes up at least 95 % by weight of the total amount of solvent present in the suspension. The aqueous solvent may also be a mixture of the aforementioned water-miscible organic solvent and water. In the latter case, the weight ratio of water to water-miscible organic solvent in the aqueous solvent preferably is in the range of from 99 : 1 to 1 : 1 ; more preferably in the range of from 50 : 1 to 3 : 1 ; and most preferably in the range of from 20 : 1 to 4 : 1 . Expressed differently the amount of organic solvent may be from 1 to 50 % by weight, more preferably from 2 to 25% by weight, and most preferably from 5 to 20% by weight, based on the total weight of the aqueous solvent.
The aqueous suspension will usually contain the microcapsules in an amount of at least 5 % by weight and the amount may be as high as 50 % by weight or even higher, in each case based on the total weight of the aqueous suspension and calculated as the total amount of aminoplast- polymer and pyrimethanil. Frequently, the aqueous suspension will contain the microcapsules in an amount from 10 to 45 % by weight, in particular from 20 to 40 % by weight, in each case based on the total weight of the aqueous suspension and calculated as the total amount of ami- noplast-polymer and pyrimethanil. The concentration of pyrimethanil in the aqueous suspension will frequently be in the range from 5 to 40 % by weight, in particular from 15 to 30 % by weight, based on the total weight of the aqueous suspension.
If present, the concentration of the polymeric anionic surfactant A in the aqueous suspension of step (iii) will frequently be in the range from 0.1 to 15 % by weight, in particular from 0.2 to 6 % by weight, based on the total weight of the aqueous suspension.
If present, the concentration of the anionic surfactant B in the aqueous suspension of step (iii) will frequently be in the range from 0.05 to 15 % by weight, in particular from 0.1 to 6 % by weight, based on the total weight of the aqueous suspension.
The aqueous compositions according to the invention may also comprise customary formulation auxiliaries, such as viscosity-modifying additives (thickeners), antifoam agents, preservatives, buffers, inorganic dispersants, etc, which are usually employed in aqueous formulations of herbicides. Such auxiliaries may be incorporated into the aqueous suspension after step iii) of the preparation process described herein has been carried out. The amount of additives will generally not exceed 10 % by weight, in particular 5 % by weight of the total weight of the aqueous suspension. Suitable inorganic dispersants, also termed anticaking agents, for preventing agglutination of the microcapsule particles, are silica (such as, for example Sipernat® 22 from Degussa), alumina, calcium carbonate and the like. In the context of the present invention silica is a preferred inorganic dispersant. The concentration of inorganic dispersants in the final suspension will generally not exceed 2 % by weight, based on the total weight of the final suspension, and, if present, it is preferably in the range from 0.01 to 2 % by weight, in particular from 0.02 to 1 .5 % by weight and especially from 0.1 to 1 % by weight, based on the total weight of the final suspension.
Suitable thickeners are compounds which affect the flow behavior of the suspension concen- trate and may assist in stabilizing the aqueous suspension against caking and sedimentation. Mention may be made, in this connection, for example, of commercial thickeners based on polysaccharides, such as methylcellulose, carboxymethylcellulose, hydroxypropylcellulose (Klucel® grades), Xanthan Gum (commercially available e.g. as Kelzan® grades from Kelco or Rhodo- pol® grades from Rhodia), synthetic polymers such as acrylic acid polymers (Carbopol® grades), polyvinyl alcohol (e.g. Mowiol® and Poval® grades from Kuraray) or polyvinyl pyrrolones, silicic acid or phyllosilicates such as montmorillonite and bentonites, which may be hydrophobized, (commercially available as Attaclay® grades and Attaflow® grades from BASF SE; or as
Veegum® grades and Van Gel® grades from R.T. Vanderbilt). In the context of the present invention Xanthan Gum is a preferred thickener. The concentration of thickeners in the aqueous suspension will generally not exceed 5 % by weight, based on the total weight of the aqueous suspension, and is preferably in the range from 0.01 to 3.5 % by weight, in particular from 1 to 3 % by weight and especially from 2 to 3,5 % by weight, based on the total weight of the aqueous suspension.
Antifoam agents suitable for the formulations according to the invention are, for example, sili- cone emulsions (such as, for example, Silicone SRE-PFL from Wacker or Rhodorsil® from Bluestar Silicones, FoamStar® from BASF), long-chain alcohols, fatty acids, organofluorine compounds and mixtures thereof.
Suitable preservatives to prevent microbial spoiling of the compositions of the invention include formaldehyde, alkyl esters of p-hydroxybenzoic acid, sodium benzoate,
2-bromo-2-nitropropane-1 ,3-diol, o-phenylphenol, thiazolinones, such as benzisothiazolinone, 5- chloro-2-methyl-4-isothiazolinone, pentachlorophenol, 2,4-dichlorobenzyl alcohol and mixtures thereof. Commercially available preservatives that are based on isothiazolinones are for example marketed under the trademarks Proxel® (Arch Chemical), Acticide® MBS (Thor Chemie) and Kathon® MK (Rohm & Haas).
If appropriate, the aqueous suspension according to the invention may comprise buffers to regulate the pH. Examples of buffers are alkali metal salts of weak inorganic or organic acids such as, for example, phosphoric acid, boric acid, acetic acid, propionic acid, citric acid, fumaric acid, tartaric acid, oxalic acid and succinic acid.
In addition, the aqueous suspensions can be formulated with conventional binders, for example aqueous polymer dispersions, water-soluble resins, for example water-soluble alkyd resins, or waxes. In other particular groups of embodiments, the microcapsule composition is in the form of solid composition. Such a solid composition contains the microcapsules of solid pyrimethanil, optionally one or more surfactants, in particular the polymeric surfactant A and optionally the anionic surfactant B, and optionally an inert solid carrier material. The solid composititions may e.g. be redispersible powders, water-dispersible granules wettable powders and the like.
Solid carriers include e.g. mineral earths such as silicas, silica gels, silicates, talc, kaolin, limestone, lime, chalk, bole, loess, clay, dolomite, diatomaceous earth, calcium sulfate, magnesium sulfate, magnesium oxide, ground synthetic materials, fertilizers such as ammonium sulfate, ammonium phosphate, ammonium nitrate, ureas, and products of vegetable origin such as ce- real meal, tree bark meal, wood meal and nutshell meal, cellulose powders, or other solid carriers.
The solid compositions according to the invention may also comprise customary formulation auxiliaries, such as antifoam agents, preservatives, buffers, inorganic dispersants, etc, which are usually employed in solid formulations of herbicides. Such auxiliaries may be incorporated into the solid formulation at any conventional stage of their preparation process. The amount of additives will generally not exceed 10 % by weight, in particular 5 % by weight of the total weight of the solid composition.
The solid composition may be obtained from an aqueous suspension which is primarily formed in the process for preparing the microcapsule composition as described herein by removing the aqueous phase from the aqueous suspension. Removal of the aqueous phase can be achieved by either separating the aqueous phase from the solid microparticles, e.g. by centrifugation or filtration. Preferably, the aqueous phase is removed by an evaporation process, such as spray drying or freeze dry. As outlined above, the method for producing the microcapsules and the composition as disclosed above according to any of claims 1 to 6 and the composition according to any of claims 7 to 10, wherein the method comprises following steps:
(i) providing an aqueous suspension or dispersion of pyrimethanil particles;
(ii) adding an aminoplast pre-condensate to the aqueous suspension,
(iii) initiating the polycondensation of the amoniplast pre-condensate,
(iv) stabilization of the capsule suspension by formulation.
In the first step an aqueous suspension or dispersion of pyrimethanil particles is provided; For this, solid pyrimethanil is suspended or dispersed in an aqueous solvent, in particular in water. The aqueous solvent may contain one or more surfactants, in particular at least one polymeric surfactant A as a protective colloid as described above and optionally one or more anionic surfactants B.
According to another embodiment of the invention pyrimethanil is dispersed in water in the presence of surfactants and aminoplast pre-condensate.
It has been found beneficial to comminute the solid pyrimethanil particles in the aqueous sus- pension to the desired particle size. Preferably, the particle size of the pyrimethanil particles in the aqueous suspension is less than 45 μηι, in particular it will not exceed 45 μηι, preferably not exceed 30 μηι and in particular not exceed 25 μηι. The particle size given is the so called devalue. Preferably the active substance particles have an average particle diameter, herein also termed dso-value, ranging from 1 to 25 μηη, in particular from 1.2 to 20 μηη, especially from 1.5 to 10 μηη. The dso-value is defined as the value that is above the diameters of 50 % by weight of the particles and below the diameters of 50 % by weight of the particles. The dgo value as well as the deo value can be calculated from the particle size distribution of the pyrimethanil particles which can be determined by conventional methods such as dynamic light-scattering at 25 °C and a concentration in the range of 0.1 to 1 % by weight.
It has been found beneficial, if the aqueous suspension of step i) contains at least one anionic polymeric surfactant A, in particular an anionic polymeric surfactant which comprises or is selected from the polymeric surfactants of group A.3. If present, the concentration of the polymeric anionic surfactant A, which is in particular selected from the surfactants of group A.3, in the reaction mixture of step iii) will frequently be in the range from 0.1 to 10 % by weight, in particular from 1 to 6 % by weight, based on the total weight of the aqueous suspension.
The aqueous suspension of the pyrimethanil particles can be provided by analogy to known methods of preparing aqueous suspensions of pyrimethanil, e.g. as described in WO
201 1/023759. Usually the method comprises a step i.a), where solid pyrimethanil, in particular a crystalline form of pyrimethanil, such as pyrimethanil anhydrate or one of the hydrate forms, and the aqueous solvent and optionally at least a part of the surfactant are mixed in any conventional mixing device which is capable of providing sufficient shear to form the desired suspension. Suitable mixing devices include in particular high shear mixers, such as Ultra-Turrax apparatus, static mixers, e.g. systems having mixing nozzles, agitator bead mills, colloid mills, cone mills and other homogenizers. In general, the sequence in which the individual components are combined is not critical. However, it may be advantageous to carry step i.a) out by firstly mixing the solvent and the surfactant until a homogenous mixture is obtained, and then adding the solid pyrimethanil with shear to said homogenous mixture. The mixture obtained from step i.a), i.e. in the form of a coarse suspension, is then subjected to suitable means for reducing the particle size of the pyrimethanil particles present in the mixture typically to below 40 μηη, preferably to below 30 μηη and in particular to below 30 μηη (D9o-value), especially 0.5 to 15 μηη (fot wet milling) and 1 to 30 μηη (dry milling) (hereinafter step i.b). Step i.b) may be carried out by any physical attrition method, such as grinding, crushing or milling, in particular by wet grinding or wet milling, including e.g. bead milling, hammer milling, jet milling, air classifying milling, pin milling, cryogenic grinding processes and the like. Steps i.a) and i.b) are usually performed subsequent- ly. However it is also possible to perform these steps together.
Further the aqueous suspension of step i) contains further a dispersing agent.
In step ii) of the method according to the invention, an aminoplast pre-condensate is added to the aqueous suspension of step i), which, upon curing in step iii), forms the solid, water- insoluble aminoplast polymer, which embeds or surrounds the solid pyrimethanil particles, be- cause the polycondensation preferentially occurs on the surface of the solid pyrimethanil particles. The amount of aminoplast pre-condensate added in step ii) is chosen such that the desired amount of aminoplast polymer in the final microcapsule composition is achieved. In fact, the amount added corresponds to the amount of aminoplast resin in the microcapsules taking into account that the mass is reduced by the amout if water which is formed during the polycon- densation, and is usually in the range 0.5 to 40 % by weight, in particular from 1 to 35 % by weight and especially from 5 to 25 %by weight, based on pyrimethanil and calculated as organic matter.
Suitable pre-condensates, which can be added in step ii) include pre-condensates of melamine and formaldehyde, including wholly or partially etherified melamine-formaldehyde pre- condensates, urea-formaldehyde pre-condensates, thiourea-formaldehyde pre-condensates, pre-condensates of melamine, urea and formaldehyde (MUF resins), including mixtures of wholly or partially etherified melamine-formaldehyde pre-condensates and urea-formaldehyde pre- condesates, pre-condensates of urea and glutaraldehyde, pre-condensates of benzoguanamine and formaldehyde, mixtures of dicyandiamide and formaldehyde and urea-glyoxal polyconden- sates. Suitable aminoplast pre-condensates for microencapsulation are known and can be found, inter alia, in Kirk-Othmer, Encyclopedia of Chemical Technology, 3rd edition, Vol. 2, pp. 440-469, the prior art cited in the introductory part, US 4,918,317, EP 26914, EP 218887, EP 319337, EP 383,337, EP 415273, DE 19833347, DE 198351 14 and WO 01/51 197. Suitable pre-condensates are commercially available, e. g. Cymel types, such as Cymel® 303, 327, 328 or 385 (etherified melamine formaldehyde resins of Cytec), Maprenal® types, such as
Maprenal® MF 900w/95, MF 915/75IB, MF 920/75WA, MF 921w/85WA, (etherified melamine formaldehyde resins of Ineos), Kauramin® types of BASF SE, such as but not limited to Kau- ramin® 783, Kauramin® 792 or Kauramin® 753 (melamine formaldehyde resins), Kauramin® 620 or Kauramin® 621 (melamine urea formaldehyde resins) or Kaurit® types of BASF SE, such as but not limited to Kaurit® 210, 216, 217 or 220 (urea formaldehyde resins) and Luracoll® types such as but not limited to Luracoll® SD (etherified melamine formaldehyde resins) Luwipal(R) types such as but not limited to Luwipal (R) 063, Luwipal(R) 069 (etherified mela- mine formaldehyde resins), or Plastopal(R) types such as but not limited to Plastopal(R) BTM, Plastopal(R) BTW (etherified urea formaldehyde resins).
In suitable urea-formaldehyde or thiourea-formaldehyde pre-condensates, the molar ratios of urea or thiourea to formaldehyde are generally in the range from 1 : 0.8 to 1 : 4, in particular from 1 : 1.5 to 1 : 4, especially from 1 :2 to 1 : 3.5.
In suitable melamine-formaldehyde or melamine-(thio)urea-formaldehyde pre-condensates, the molar ratios of melamine to formaldehyde are generally in the range from 1 : 1 .5 to 1 : 10, in particular from 1 : 3 to 1 : 8 preferably 1 : 4 to 1 :6.
In suitable melamine-formaldehyde or melamine-(thio)urea-formaldehyde pre-condensates, the molar ratios of melamine + urea or thiourea to formaldehyde are generally in the range from 1 : 0.8 to 1 : 9, in particular from 1 : 2 to 1 : 8 preferably 1 : 3 to 1 :6. The molar ratio of urea or thiourea to melamine may be in the range from 50 : 1 to 1 : 100 and in particular from 30 : 1 to 1 : 30.
The pre-condensates may be used in the form of etherified pre-condensates of amino compound and aldehyde. In these etherified pre-condensates the methylol groups formed by the reaction of the amino groups with formaldehyde with an alkanol or an alkandiol, in particular with a Ci-C4-alkanol such as methanol, ethanol, n-propanol or n-butanol, in particular methanol, or a C2-C4-alkandiol such as ethylene glycol. The degree of etherification of these resins can be adjusted by the molar ratio of amino groups to alkanol which is typically in the range from 10 : 1 to 1 : 10, preferably in the range from 2 : 1 to 1 : 5.
The pre-condensates are most preferably selected from the group consisting of melamine- formaldehyde resins, including wholly or partially etherified melamine-formaldehyde pre- condensates, and urea-formaldehyde pre-condensates and mixtures thereof. Especially, the pre-condensate is a wholly or partially etherified melamine-formaldehyde condensate, which may contain small amounts, e.g. 1 to 20 mol.-%, based on melamine, of urea.
Addition of the pre-condensate to the aqueous suspension is normally achieved by adding the pre-condensate in the form of an aqueous or alcoholic solution of the pre-condensate to the aqueous suspension or by mixing suitable amounts of the dissolved pre-condensate. Preferably, suitable mixing devices, such as stirrers or inline-mixers are used in order to achieve a uniform distribution of the pre-condensate in the aqueous suspension. It may be beneficial to add the pre-condensate, preferably in the form of a solution, to the aqueous suspension of pyrime- thanil with stirring. Preferably, the addition of the pre-condensate is performed under conditions, where the polycondensation reaction is slow or does not occur, e.g. where either the pH of the aqueous suspension at least pH 6, e.g. in the range form pH 6 to pH 10, or where the temperature does not exceed 30°C or both.
The polycondensation of the aminoplast pre-condensate can be affected in a well-known manner, e.g. by lowering the pH of the aqueous suspension or by heating the aqueous suspension or combinations of these measures. During the polycondensation, the aminoplast pre- condensate is converted into a water-insoluble aminoplast resin, which precipitates from the aqueous phase and deposits preferably on the surface of the solid pyrimethanil particles, thereby embedding or surrounding the solid pyrimethanil particles.
Preferably, the polycondensation of the aminoplast is performed at pH less than pH 6, in par- ticular at a pH of at most pH 5, e.g. in the range of pH 0 to 6, more particularly in the range from pH 1 to 5 or in the range from pH 2 to 4.
The pH of the aqueous suspension is usually adjusted by addition of suitable amounts of an organic or inorganic acid, such as sulfuric acid, hydrochloric acid, phosphoric acid, a carboxylic acid including alkanoic acids, alkandioic acids or hydroxycarboxylic acids, such as formic acid, acetic acid, propionic acid, oxalic acid, malic acid or citric acid, and alkyl or arylsulfonic acids such as methanesulfonic acid or toluenesulfonic acid.
Preferably, the polycondensation of the aminoplast pre-condensate is performed at elevated temperature, in particular at a temperature of at least 30 °C, in particular at least 40 °C or at least 50°C, e.g. at a temperature in the range of 30 to 100°C, in particular in the range of 40 to 95°C or in the range of 50 to 90 °C. It may be possible to effect the start of the polycondensation of the aminoplast at a comparatively low temperature, e.g. a temperature in the range of 30 to 65°C or 35 to 60°C and then complete the polycondensation reaction at a higher temperature of e.g. 50 to 100°C or 60 to 90°C. The time for completing the polycondensation may vary, depending on the reactivity of the pre-condensate, the temperature and the pH of the aqueous suspension and may take from 1 h to 24 h, in particular from 2 to 12 h. Preferably, the polycondensation reaction is at least partly performed at temperatures of at least 50°C, in particular at least 60°C, e.g. for 1 to 8 h at a temperature in the range from 50 to 100°C, in particular 60 to 90°C.
The thus obtained aqueous suspension of the pyrimethanil microcapsule particles may be neutralized by the addition of a base. Preferably, the pH of the suspension is adjusted to a pH of at least 6, e.g. a pH in the range of pH 6 to 10, in particular in the range of pH 6.5 to 9.0.
From the thus obtained aqueous suspension the microcapsules can be isolated, e.g. by filtration or centrifugation, or the aqueous suspension may be spray-dried, granulated or freeze-dried, to obtain a solid composition in the form of a powder or granules. The solid composition may be redispersed or formulated by using formulation auxiliaries as described above.
According to the invention the method comprises as step iv) a stabilization of the capsule sus- pension by formulation.
It was found that for the stabilization nonionic surfactants of formula II is required. Preferred nonionic surfactants include the neutral surface-active compounds of the formula II,
R'-(0-B)n-OH II
wherein
R' is a hydrocarbon radical having from 8 to 40 and more preferably from 12 to 30 carbon atoms and optionally one oxygen atom,
B is C2-C4-alkane-1 ,2-diyl such as 1 ,2-ethylene, 1 ,2-propylene or 1 ,2-butylene or a combina- tion thereof and more preferred 1 ,2-ethylene or a combination thereof with 1 ,2-propylene, and
n is from 3 to 100, preferably from 4 to 50 and more preferred from 5 to 40.
Examples of suitable hydrocarbon radials R' include the radicals mentioned for R. In a preferred embodiment of the invention the radical R' is a phenyl radical being substituted with one C4-C18- alkyl group.
If present, the amount of nonionic surfactant, in particular the surface-active compound of the formula II, is in the formulation preferably from 1 to 150 g/L, in particular from 2 to 60 g/L. In one particular embodiment of the invention, the composition does not contain nonionic surfactant or less than 1 % by weight of nonionic surfactant, in particular less than 0.5 % by weight of nonionic surfactant, based on the total amount of pyrimethanil and aminoplast polymer.
Further comprises the formulation a biocide. Suitable bactericides are bronopol and isothiazoli- none derivatives such as alkylisothiazolinones and benzisothiazolinones.
If bactericides is present in the formulation, the amount of biocide in the final formulation ranges from 0.1 - 1 %w/w, preferably from 0.1 - 0.5 % w/w, even more preferred from 0,1 - 0,3 % w/w. Further comprises the formulation a thickener. Suitable thickeners are polysaccharides (e.g. xanthan gum, carboxymethylcellulose), anorganic clays (organically modified or unmodified), polycarboxylates, and silicates. If thickeners are present in the formulation, the amount of thickeners in the final formulation ranges from 0,1 - 1 ,5 % w/w, preferably from 0,1 - 1 ,0% w/w, even more preferred from 0,2 - 0,5 %.
The invention also relates to uses of the microcapsule composition of the invention for protect- ing crop plants and to methods of controlling fungal diseases, which comprise applying the formulations, in diluted or undiluted form, to plants, their environment and/or seeds.
The compositions of the invention provide for a very good control of fungal pathogens in non- crop areas, especially at high application rates. However, generally no higher application rates are required in comparison with conventional formulations of non-encapsulated pyrimethanil for achieving similar control.
In crops such as soybean, cotton, oilseed rape, flax, lentils, rice, sugar beet, sunflower, tobacco and cereals, such as, for example maize or wheat, the compositions of the invention are active against broad-leaved weeds and grass weeds and provide for less damage to the crop plants in comparison with conventional formulations of non-encapsulated pyrimethanil. This effect is par- ticularly observed at low application rates.
Furthermore, the compositions of the invention provide for long lasting residual activity, which exceeds the residual activity of conventional formulations of non-encapsulated pyrimethanil.
Depending on the application method in question, the formulations of the invention can additionally be employed in a further number of crop plants to remove undesired plants. Crops which are suitable are, for example, the following: potatoes sugar beets, tobacco, wheat, rye, barley, oats, rice, corn, cotton, soybeans, rape, legumes, sunflowers, coffee or sugar cane; fruits; vines; ornamentals; or vegetables, such as cucumbers, tomatoes, beans or squashes.
In general, the compositions of the invention as described herein are useful for combating undesired vegetation. For this purpose, the compositions may be applied as such or are preferably applied after dilution with water. Preferably, for various purposes of end user application, a so- called aqueous spray-liquor is prepared by diluting the compositions of the present invention with water, e.g. tap water. The spray-liquors may also comprise further constituents in dissolved, emulsified or suspended form, for example fertilizers, active substances of other groups of herbicidal or growth-regulatory active substances, further active substances, for example ac- tive substances for controlling animal pests or phytopathogenic fungi or bacteria, furthermore mineral salts which are employed for alleviating nutritional and trace element deficiencies, and nonphytotoxic oils or oil concentrates. As a rule, these constituents are added to the spray mixture before, during or after dilution of the compositions according to the invention.
The compositions of the invention can be applied by the pre-emergence or the post-emergence method. If the pyrimethanil is less well tolerated by certain crop plants, application techniques may be employed where the herbicidal compositions are sprayed, with the aid of the spraying apparatus, in such a way that the leaves of the sensitive crop plants ideally do not come into contact with them, while the active substances reach the leaves of undesired plants which grow underneath, or the bare soil surface (post-directed, lay-by).
Depending on the aim of the control measures, the season, the target plants and the growth stage, the compositions of the invention are applied to such a degree that the application rates of pyrimethanil are from 0.001 to 3.0, preferably from 0.01 to 1.0 kg/ha active substance (a.s.).
To widen the spectrum of action and to obtain synergistic effects, the compositions of the invention can be mixed with a large number of representatives of other groups of fungicidal active substances and applied together with these as defined above in group A) to J).
Examples of suitable mixing partners are azoxystrobin, coumethoxystrobin, coumoxystrobin, dimoxystrobin, enestroburin, fenaminstrobin, fenoxystrobin/flufenoxystrobin, fluoxastrobin, kres- oxim-methyl, metominostrobin, orysastrobin, picoxystrobin, pyraclostrobin, pyrametostrobin, pyraoxystrobin, trifloxystrobin, 2-[2-(2,5-dimethyl-phenoxymethyl)-phenyl]-3-methoxy-acrylic acid methyl ester and 2-(2-(3-(2,6-dichlorophenyl)-1-methyl-allylideneaminooxymethyl)-phenyl)- 2-methoxyimino-N-methyl-acetamide, the group of carboxamide fungicide selected from be- nodanil, bixafen, boscalid, carboxin, fenfuram, fluopyram, flutolanil, fluxapyroxad, furametpyr, isopyrazam, mepronil, oxycarboxin, penflufen, penthiopyrad, sedaxane, tecloftalam, thifluz- amide, N-(4'-trifluoromethylthiobiphenyl-2-yl)-3-difluoromethyl-1-methyl-1 H-pyrazole-4- carboxamide, N-(2-(1 ,3,3-trimethyl-butyl)-phenyl)-1 ,3-dimethyl-5-fluoro-1 H-pyrazole- 4-carboxamide, N-[9-(dichloromethylene)-1 ,2,3,4-tetrahydro-1 ,4-methanonaphthalen-5-yl]-3- (difluoromethyl)-1-methyl-1 H-pyrazole-4-carboxamide, the group of azoles for example azacon- azole, bitertanol, bromuconazole, cyproconazole, difenoconazole, diniconazole, diniconazole-M, epoxiconazole, fenbuconazole, fluquinconazole, flusilazole, flutriafol, hexaconazole, imiben- conazole, ipconazole, metconazole, myclobutanil, oxpoconazole, paclobutrazole, penconazole, propiconazole, prothioconazole, simeconazole, tebuconazole, tetraconazole, triadimefon, triad- imenol, triticonazole, uniconazole and from the group of various actives such as tricyclazole, isoprothiolane and carpropamid.
It is of also possible to use the compositions of the present invention as a tank-mix partner with other formulations. Moreover, it may be useful to apply the pyrimethanil-containing compositions of the invention, separately or in combination with other herbicides, jointly as a mixture with yet further plant protection agents, for example with agents for controlling pests or phytopathogenic fungi or bacteria. Also of interest is the miscibility with mineral salt solutions which are employed for alleviating nutritional and trace element deficiencies. Nonphytotoxic oils and oil concentrates may also be added.
The following examples are intended to further illustrate the present invention without limiting its scope in any way.
I. Analytics:
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 dn-values for n = 10, 50 and 90, the35 d10, d50 and d90.
Solid content of the final dispersion was measured by evaporating the volatiles of small probe of the aqueous suspension in an oven at 105°C for 2 hours. The value indicated for the examples is an average value from three parallel experiments. II. Ingredients:
Surfactant 1 : 20% aqueous solution of poly(2-acrylamido-2-methylpropane sulfonic acid) sodium salt with pH 2.5-4;
Surfactant 2: 15% aqueous solution of sodium dodecyl sulfate
Surfactant 3: Naphthalenesulfonic acid formaldehyde condensate Sodiu salt
Pre-condensate P1 : 70% w/w aqueous solution of etherified melamine
formaldehyde pre-condensate (Luracoll® SD of BASF SE);
Pyrimethanil, purity ca. 99,9%
III. Preparation of the compositions of the invention:
Example
518.77g of water, 17 g of surfactant 2, 164.0 g of surfactant 1 , 51 .0 g pre-condensate P1 and 227.23 g of Pyrimethanil, which had been previously wet milled to a particle size (d90) of about 3 μηη, where charged into a 2 L reaction vessel, equipped with a stirrer having anchor stirring blade (20min, 5000rpm). 12.6g of 20% w/w aqueous formic acid was added and then the reac- tion vessel was heated to 30°C and the mixture was stirred at 30°C. Then the reaction vessel was slowly heated within 1 h to 80°C and the temperature was kept at 80°C for further 2 h. Then the reactor was cooled to RT. The resulting aqueous suspension had a solid content of 22.9 soll%. The particle size Distribution is given in table 1 .
Example 2
590 g of water, 18.67g of surfactant 2, 252 g of, Pyrimethanil, which had been previously air- milled to a particle size (d90) of about 3 μηη, 57.16 g of pre-condensate P1 and 12.6g of a 20%w/w aqueous formic acid where charged into a 2L reaction vessel, equipped with a stirrer having anchor stirring blade (20min, 5000rpm). Then 91 .00g of surfactant 1 was added— The reaction vessel was heated to 30°C and the mixture was stirred for 1 h at 30°C with 300rpm. Then the reaction vessel was slowly heated within 1 h to 80°C and the temperature was kept at 80°C for further 2 h. Then the reactor was cooled to RT and the pH of the obtained suspension was adjusted to pH 7 by adding triethanol amine.
The resulting aqueous suspension had a solid content of 22.7%. The particle size distribution is given in table 1 .
Table 1
Particle size distribution (μηη)
Figure imgf000023_0001
Examples 2 - 4: The microparticles of examples 2 to 4 were prepared by using the following protocol:
Water, Pyrimethanil, which had been previously air-milled to a particle size (d90) of about 3 μηη, pre-condensate P1 , surfactant 1 and aqueous formic acid where charged into a 2L reaction vessel, equipped with a stirrer having anchor stirring blade. The reaction vessel was heated to 30°C and the mixture was stirred for 40 minutes at 30°C with 700 rpm. Then surfactant 2 was added. The reaction vessel was heated to 30°C and the mixture was stirred for 1 h at 30°C with 300 rpm. Then the reaction vessel was slowly heated within 1 h to 80°C and the temperature was kept at 80°C for further 2 h. Then the reactor was cooled to RT and the pH of the obtained suspension was adjusted to pH 7 by adding triethanol amine.
Table 2
Figure imgf000024_0001
Table 3: Analytical assessment of exampl
Particle size distribution (μηη):
Figure imgf000024_0002
For examples 2 - 4, the amount of free pesticide (non-encapsulated and released) was determined as followed: First, a 10 w% solution of poloxamer 335 (Pluronic® PE 10500) was prepared which was adjusted to pH 5 with acetic acid. This solution actedas a receiver solution for non- or not well encapsulated pesticide. To 250 ml of thereceiver solution was added 125 mg of the microparticle dispersion and stirred over 4days. After 10min, 5h, 1 d and 3d samples were taken and drawn through a 0.2 μηη Teflon filter to remove intact microparticles. In the filtrate, the amount of pesticide was determined by reverse phase HPLC and normalized in way that the entire amount of pesticide would account for 100% (100% "free fungicide", this is found, e.g., if no encapsulationwould have taken place at all). The results are summarized in table 4: Table 4: Release of Pyrimethanil from microparticles
Figure imgf000025_0001
IV. Formulation examples:
General procedure:
The aqueous microparticle suspensions of the present invention are mixed with water and additives while stirring at room temperature. Thus, an aqueous CS agrochemical formulation was prepared by mixing an aqueous suspension of microparticles of the invention with an anionic surfactant, a non-ionic surfactant, antifoam, preservative, propylene glycole as antifreeze agent, thickener in such amounts that the final concentration is as follows:
15-30 wt% Pyrimethanil in the form of microparticles;
0.2-1 wt% anionic surfactant, e.g. naphthalenesulfonic acid formaldehyde condensate sodium salt or phenolsulfonic acid urea formaldehyde condensate;
1-6 wt% non-ionic alkylalkoxylated surfactants, e.g. a non-ionic block copolymer of
ethyleneoxide and propyleneoxide, such as Pluronic® PE 10500;
0.1-0.05 wt% antifoam, e.g. a silicon defoamer, such as Wacker Silicon® SRE-PFL;
0.2-5 wt% polymeric dispersant;
0.2 wt% preservatives, such as Acticide® MBS;
0.5-0.7 wt% propylene glycol antifreeze;
0.1-0.3 wt% thickener, such as xanthan gum, e.g. Rhodopol® G;
and water up to 100 w%.
Example 6: CS-Formulation
51 1 g of the capsule suspension from example 2 were mixed at RT with 70 g propylene glycol, 30 g of a triblockcopolymer of ethyleneoxide/propyleneoxide, 20 g phenolsulfonic acid urea formaldehyde condensate, 5 g silicon defoamer, 2 g preservative, 3 g xanthan gum and water up to 1 liter. Storage stability of formulation at different temperatures was studied (see Table 5) Table 5: Formulation storage stability (Particle Size Distribution)
Figure imgf000026_0001
* cycling temperatures from -10°C to +10°C with cycle interval of 12h
** cycling temperatures from -5°C to +30°C with cycle interval of 12h
V. Fungicidal activity
The biological activity of the aqueous microparticle suspensions was evaluated by using a seven day and three day preventive spray application in lambs lettuce infested with Botrytis cinerea (grey mold).
Lambs lettuce plants (5 weeks old) were sprayed with the microparticle suspensions (diluted in water) seven days before artificial inoculation with B. cinerea. The concentration of the spray dilution was chosen in a manner that defined use rates of 800, 300 and 135 ppm were applied (in 100 ml spray volume). Four replicates were sprayed per treatment.
As a reference, the non-encapsulated formulation of same active ingredient was used.
After the application in a spray chamber with a horizontal spray boom, plants were kept in a greenhouse chamber at 19,5-21 °C, 40-60% RH for seven days.
Afterwards all plants were artificially inoculated with a B. cinerea spore suspension (2 x 106 Spores/ml Lihof isolate in 2% malt broth) until run-off.
To favor disease development all plants were kept under dark conditions with 80-90% RH at 21 °C for approximately 4-6 days.
During this time, the plants were tended, and their response to the individual treatments was evaluated when the untreated control showed high enough disease level to differentiate treatments. The evaluation was carried out by visual estimation of diseased leaf area (percentage), using a scale from 0 to 100. 100 means all leaves were fully diseased, 0 means no damage, or normal course of growth. A good fungicidal activity is given at values of at least 25% and a very good fungicidal
activity is given at values of at least 0-10% infestation. In comparison to the current available market solution (0% polymer = non-encapsulated SC) the encapsulated formulations should bring under best case (1 -3 day preventive) and worst case (7 day preventive) conditions at least performance on a level of non-encapsulated formulation.
The results are summarized in the following tables 6 and 7:
Table 6: Infestation level of lambs lettuce applied with Pyrimethanil encapsulated. Results of infestation after 3 days
Figure imgf000027_0001
Table 7: Infestation level of lambs lettuce applied with Pyrimethanil encapsulated. Results of infestation after 7 days
Lambs lettuce a.i amount Reference Example 2
(7 days, preventive) A.i Crystals
(0% polymer) (10% polymer)
Infestation in green800ppm 55 3
house test [%]
300ppm 88 9
128ppm 84 9

Claims

A microcapsules comprising solid pyrimethanil which is surrounded or embedded by an aminoplast polymer.
The microcapsules according claim 1 , wherein the aminoplast polymer is selected form the group consisting of melamine formaldehyde resins and/or urea formaldehyde resins and/or melamine urea formaldehyde resins.
The microcapsules according claim 1 or 2, wherein the microcapsule comprises from 1 wt% to 40 wt% of the aminoplast polymer based on total capsule weight.
The microcapsules according claim 3, wherein the microcapsule comprises from 10 wt% to 20 wt% of the aminoplast polymer based on total capsule weight.
The microcapsules according to any of claims 1 to 4, wherein the microcapsule have an average particle diameter in the range from 0,5 to 100 μηη as determined by dynamic light scattering of an aqueous dispersion of the microcapsules.
The microcapsules according to claim 5, wherein the microcapsule have a weight average particle diameter in the range from 1 to 10 μηη as determined by dynamic light scattering of an aqueous dispersion of the microcapsules.
A composition comprising microcapsules according to any claims 1 to 6, which comprises further at least one anionic polymeric surfactant having a plurality of sulfate or sulfonate group.
The composition according to claim 7, which comprises at least one anionic emulsifier in addition to the polymeric surfactant.
9. The composition according to claim 7 or 8, which is an aqueous suspension of the microcapsules.
10. The composition according to claim 7 or 8, which is a solid composition of the microcap- sules.
1 1. A method for producing the microcapsules according to any of claims 1 to 6 and the composition according to any of claims 7 to 10, wherein the method comprises the following steps:
(v) providing an aqueous suspension or dispersion of pyrimethanil particles;
(vi) adding an aminoplast pre-condensate to the aqueous suspension,
(vii) initiating the polycondensation of the amoniplast pre-condensate,
(viii) stabilization of the capsule suspension by formulation.
The method according to claim 1 1 , wherein the aqueous suspension of step i) contains further at least one anionic polymeric surfactant as a protective colloid.
13. The method according to claims 1 1 or 12, wherein the aqueous suspension of step i) contains further a dispersing agent.
14. The use of the microcapsules according to any of claims 1 to 6 and the composition according to any of claims 7 to 10 for controlling undesired fungal pathogens.
The method of claim 1 1 , where the stabilization step iv) includes adding dispersants, bio- cides, thickeners, anti-freezing agents and further formulants to finalize the composition
PCT/EP2016/067367 2015-08-03 2016-07-21 Microcapsule compositions comprising pyrimethanil WO2017021159A1 (en)

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US10695734B2 (en) 2015-11-23 2020-06-30 Basf Se Microcapsule comprising a polyester-urethane shell and a hydrophilic core material
EP4011208A1 (en) * 2020-12-08 2022-06-15 BASF Corporation Microparticle compositions comprising fluopyram

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GB2113170A (en) * 1982-01-18 1983-08-03 Kureha Chemical Ind Co Ltd Microencapsulated agricultural pesticides
CN103783046A (en) * 2013-12-09 2014-05-14 海利尔药业集团股份有限公司 Fungicidal composition containing prothioconazole and pyrimethanil
WO2014135392A1 (en) * 2013-03-07 2014-09-12 Basf Se Co-crystals of pyrimethanil and selected dithiine tetracarboximide
CN104351188A (en) * 2014-11-11 2015-02-18 济南新起点医药科技有限公司 Microcapsule suspension for preventing and treating gray mold

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GB2113170A (en) * 1982-01-18 1983-08-03 Kureha Chemical Ind Co Ltd Microencapsulated agricultural pesticides
WO2014135392A1 (en) * 2013-03-07 2014-09-12 Basf Se Co-crystals of pyrimethanil and selected dithiine tetracarboximide
CN103783046A (en) * 2013-12-09 2014-05-14 海利尔药业集团股份有限公司 Fungicidal composition containing prothioconazole and pyrimethanil
CN104351188A (en) * 2014-11-11 2015-02-18 济南新起点医药科技有限公司 Microcapsule suspension for preventing and treating gray mold

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* Cited by examiner, † Cited by third party
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US10695734B2 (en) 2015-11-23 2020-06-30 Basf Se Microcapsule comprising a polyester-urethane shell and a hydrophilic core material
US11077417B2 (en) 2015-11-23 2021-08-03 Basf Se Microcapsule comprising a polyester-urethane shell and a hydrophobic core material
EP4011208A1 (en) * 2020-12-08 2022-06-15 BASF Corporation Microparticle compositions comprising fluopyram
WO2022122520A1 (en) * 2020-12-08 2022-06-16 Basf Corporation Microparticle compositions comprising fungicides

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