Method for preparing coated organic particles

Abstract

The present invention is in the field of coated organic particles, in particular coated organic particles comprising small molecules, by using atomic layer deposition. The invention relates to a method for preparing coated organic particles, comprising the following steps in the following order: (a) moving particles containing an organic compound relative to one another, (b) contacting the organic particles with a pretreatment compound in the gaseous state, where the pretreatment compound is water, an alcohol or a carboxylic acid, and (d) removing the organic compound from the pretreatment compound. And (c) contacting the organic particles with a metal or semimetal-containing compound in a gaseous state and a decomposition compound in this order.

Description

[0001] The present invention is in the field of coated organic particles, in particular coated organic particles comprising small molecules, by using atomic layer deposition.

[0002] Small molecules, such as drugs, agricultural chemicals or laundry additives, are usually formulated to achieve effects that the original molecule does not have. Examples are protection against certain environments, compatibility in various media or controlled release, i.e. release over an extended period of time. A typical method to achieve this is to encapsulate the compound so that the contained compound is shielded by the capsule shell and is not released or is only released slowly, such as by diffusion through the shell. Various techniques can be used for encapsulation. Atomic layer deposition is a particularly useful technique because it allows very accurate, uniform and very thin deposition of inorganic or organic-inorganic hybrid materials. This allows a high degree of control over encapsulation, such as accurate adjustment of the release curve, and also high active ingredient loading.

[0003] D. Zhang et al., Nanoscale, Vol. 9 (2017), pp. 11410-11417, disclose the encapsulation of budesonide and lactose. They used a typical atomic layer deposition procedure, as it is used in many other applications. However, this method is only applicable to a very limited number of compounds. Most compounds are destroyed and / or agglomerated in this way.

[0004] US2018 / 0 221 294A1 discloses a method for coating drug particles (such as paracetamol) by ALD using trimethylaluminum. This method involves harsh conditions, so only very stable compounds like paracetamol can be coated without significant degradation. In addition, these particles tend to agglomerate in this method, so they need to be repeatedly deagglomerated during the method, which is difficult to scale up industrially.

[0005] Therefore, the object of this invention is to provide a coating method, which is applicable to a wide range of compounds, including sensitive compounds. This method is intended to keep the compound to be coated, so that it remains essentially unchanged and avoids particle agglomeration at the same time. The particle shell should have a very uniform thickness. The method should be robust, so it can be easily scaled up to industrial scale and allow interference-free production.

[0006] These objects are achieved by a method for preparing coated organic particles, comprising the steps in the following order:

[0007] (a) causing particles containing organic compounds to move relative to each other,

[0008] (b) contacting the organic particles with a pretreatment compound in a gaseous state, wherein the pretreatment compound is water, an alcohol or a carboxylic acid, and

[0009] (c) contacting the organic particles sequentially with a metal- or semi-metal-containing compound and a decomposition compound in a gaseous state.

[0010] Preferred embodiments of the invention can be found in the description and claims. Combinations of different embodiments fall within the scope of the invention.

[0011] In the method according to the invention, particles containing organic compounds are coated. These particles can also be referred to as organic particles. In the context of the present invention, organic refers to compounds containing at least one carbon-hydrogen or at least one carbon-carbon bond, preferably they contain at least one carbon-hydrogen and at least one carbon-carbon bond. Typically, the organic compound contains more than 80 at.-%, preferably more than 90 at.-% of non-metals, in particular completely or substantially completely. Even more preferably, these non-metals are C, H, O, N, S, Se and / or P.

[0012] The organic compound can be an agrochemical such as an insecticide, a fungicide, or a herbicide. Insecticides include insecticides from the following classes: carbamates, organophosphates, organochlorine insecticides, phenylpyrazoles, pyrethroids, neonicotinoids, spinosins, avermectins, milbemycins, juvenile hormone analogs, alkyl halides, organotin compounds, nereis toxin analogs, benzoylureas, dihydrazides, METI acaricides, and insecticides such as chloropicrin, pymetrozin, flonicamid, clofentezine, hexythiazox, etoxazole, diafenthiuron, fenpropimorph, triclofenac, cypermethrin, DNOC, buprofezin, cyromazine, amitraz, hydrazone, acequinoxaline, pyrimidine, rotenone, or derivatives thereof.

[0013] The fungicides include fungicides from the following classes: dinitroaniline, allylamine, anilinopyrimidine, antibiotics, aromatic hydrocarbons, benzenesulfonamide, benzimidazole, benzisothiazole, benzophenone, benzothiadiazole, benzotriazine, benzyl carbamate, carbamate, carboxamide, carboxylic acid diamide, chloronitrile, cyanoacetamide oxime, cyanoimidazole, cyclopropanecarboxamide, dicarboximide, dihydrodioxazine, dinitrophenyl crotonate, dithiocarbamate, dithiolane, ethyl phosphonate, ethylaminothiazolecarboxamide, guanidine, hydroxy-(2-amino)pyrimidine, hydroxyaniline, imidazole, imidazolinone, inorganic substances, isobenzofuranone, methyl Oxyacrylate, methoxycarbamate, morpholine, N-phenylcarbamate, oxazolidinedione, oxime acetate, oxime acetamide, peptidyl pyrimidine nucleoside, phenylacetamide, phenylamide, phenylpyrrole, phenylurea, phosphonate, phosphorothioate, o-aminobenzoic acid, phthalimide, piperazine, piperidine, propionamide, pyridazinone, pyridine, pyridylmethylbenzamide, pyrimidineamine, pyrimidine, pyrimidonehydrazone, pyrroloquinolinone, quinazolinone, quinoline, quinone, sulfonamide, sulfamoyltriazole, thiazolecarboxamide, thiocarbamate, thiophanate, thiophenecarboxamide, toluamide, triphenyltin compounds, triazine, triazole.

[0014] The herbicides include herbicides from the following classes: acetamides, amides, aryloxyphenoxypropionates, benzamides, benzofurans, benzoic acids, benzothiadiazinones, bipyridiniums, carbamates, chloroacetamides, chlorocarboxylic acids, cyclohexanediones, dinitroanilines, dinitrophenols, diphenyl ethers, glycine, imidazolinones, isoxazoles, isoxazolidinones, nitriles, N-phenylphthalimide, oxadiazoles, oxazolidinediones, oxyacetamides, phenoxycarboxylic acids, phenylcarbamates, Phenylpyrazole, phenylpyrazoline, phenylpyridazine, phosphinic acid, phosphoramidate, phosphorodithioate, o-carbamoylbenzoate, pyrazole, pyridazinone, pyridine, pyridinecarboxylic acid, pyridinecarboxamide, pyrimidinedione, pyrimidinyl(thio)benzoate, quinolinecarboxylic acid, semicarbazone, sulfonylaminocarbonyltriazolinone, sulfonylurea, tetrazolinone, thiadiazole, thiocarbamate, triazine, triazone, triazole, triazolinone, triazolocarboxamide, triazolopyrimidine, triketone, uracil, urea. Mixtures of different pesticides are also suitable.

[0015] The organic compound may be a drug. Drugs include antipyretics, such as ibuprofen, naproxen, ketoprofen, nimesulide, choline salicylate, magnesium salicylate and sodium salicylate, paracetamol / acetaminophen, nabumetone, antipyrine; analgesics, such as paracetamol / acetaminophen, nonsteroidal anti-inflammatory drugs such as salicylates, and opioids such as morphine and oxycodone; antimalarials, such as quinine, chloroquine, amodiaquine, pyrimethamine, proguanil, sulfonamides, mefloquine, atovaquone, primaquine, artemisinin, halofantrine, doxycycline, clindamycin; antibiotics, such as penicillins, cephalosporins, polymyxins, rifamycins, intercalary mycins, quinolones, sulfonamides, macrolides, lincosamides, tetracyclic mood stabilizers, like valproate, lamotrigine, carbamazepine, aripiprazole, risperidone, olanzapine, quetiapine, asenapine, paliperidone, ziprasidone, lurasidone; hormone replacements, like estrogens and progestins; oral contraceptives, like estrogens, the progestin levonorgestrel, ulipristal acetate, mifepristone, and misoprostol; stimulants, like methylphenidate and amphetamines; tranquilizers, like meprobamate, chlorpromazine, reserpine, chlordiazepoxide, diazepam, and alprazolam; or statins, like lovastatin, pravastatin, and simvastatin.

[0016] The organic compound may be a cleaning additive such as a surfactant or a chelating agent. Surfactants include: nonionic surfactants such as alkoxylated alcohols, diblock and multiblock copolymers of ethylene oxide and propylene oxide, and reaction products of sorbitan with ethylene oxide or propylene oxide, alkyl polyglycosides (APG), hydroxyalkyl mixed ethers, and amine oxides; anionic surfactants such as alkali metal and ammonium salts of C8-C18-alkyl sulfates, alkali metal and ammonium salts of C8-C18-fatty alcohol polyether sulfates, ethoxylated C4-C12-alkylphenols; Alkali metal and ammonium salts of sulfuric acid half esters (ethoxylation: 1 to 50 mol ethylene oxide / mol), alkali metal and ammonium salts of C12-C18 sulfonic fatty acid alkyl esters (e.g. C12-C18 sulfonic fatty acid methyl esters), and also alkali metal and ammonium salts of C12-C18-alkylsulfonic acids and alkali metal and ammonium salts of C10-C18-alkylarylsulfonic acids; amphoteric surfactants, such as betaines, for example cocamidopropyl betaine (lauramidopropyl betaine). Chelating agents include salts of ethylenediaminetetraacetic acid (EDTA), iminodisuccinic acid (IDS), S,S-ethylenediamine-N,N′-disuccinic acid (EDDS), methylglycine diacetic acid (MGDA), glutamic acid diacetic acid (GLDA), polyaspartic acid, or citrate phosphonates (e.g. 1-hydroxyethane 1,1-diphosphonic acid (HEDP)). Examples of salts include sodium, potassium and ammonium salts, in particular sodium salts, such as methylglycine diacetate trisodium salt (MGDA-Na3), glutamic acid diacetate tetrasodium salt (GLDA-Na4) or 1-hydroxyethane 1,1-diphosphonic acid tetrasodium salt (HEDP-Na4).

[0017] The organic compound can be a saturated, mono- or polyunsaturated fatty acid. Saturated fatty acids include propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, octanoic acid, nonanoic acid, capric acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, heptadecanoic acid, stearic acid, nonadecanoic acid, arachidic acid, heneicosanoic acid, behenic acid, tricosanoic acid, lignoceric acid, pentacosanoic acid, cerotic acid, heptadecanoic acid, montanic acid, nonacosanoic acid, melissic acid, henriacontanoic acid, lacceric acid, leaf licorice acid, geddic acid, ceroplastic acid and / or hexatriacontylic acid. Monounsaturated fatty acids include myristoleic acid, palmitoleic acid, saponinic acid, oleic acid, elaidic acid, vaccenic acid or erucic acid. The polyunsaturated fatty acids (also called "PUFAs") may be conjugated fatty acids, such as conjugated linoleic acid, linolenic acid, alpha-linolenic acid, arachidonic acid, eicosapentaenoic acid, docosahexaenoic acid or pinolenic acid. Preferred polyunsaturated fatty acids are the so-called ω-3 fatty acids, ω-6 fatty acids and ω-9 fatty acids.

[0018] The organic compound may also be a fat containing one or more than one of the fatty acids described above.

[0019] The organic compound preferably contains a functional group, in particular a hydroxyl group, an aldehyde or ketone group, an ether group, an ester group, an amide group, an amine group, an imine group, a nitrile group, a thiol group, a thioether group, a thioketone group, a sulfoxide group, a sulfone group, or an olefin group. The organic compound preferably has a molecular weight of less than 2000 g / mol, more preferably less than 1000 g / mol, in particular less than 600 g / mol.

[0020] Preferably, the particles have a weight average mean particle size of 0.5 to 1000 μm, more preferably 1 to 200 μm, even more preferably 1.5 to 100 μm, especially 2 to 50 μm, for example 2 to 8 μm or 5 to 20 μm. The mean particle size is preferably measured by light scattering.

[0021] In step (a) of the method according to the invention, the organic particles are moved relative to each other. This can be achieved in various ways, for example by using a mixer, such as a ploughshare mixer, a free-fall mixer or a blender; a dryer, such as a paddle dryer; an acoustic mixer; a fluidized bed reactor; a spouted bed reactor or a drum; a space reactor, such as a transport reactor; a vibration or pulse vibration device; or a cascade, such as a cascade of mixers, dryers or space reactors. Combinations of different technologies are also suitable, such as fluidization combined with vibration. A fluidized bed reactor is preferred, in particular a fluidized bed reactor combined with vibration. Therefore, preferably, the organic particles are fluidized.

[0022] The particles are moved relative to each other, typically avoiding agglomeration of particles during the coating process and producing organic particles with a more uniform coating. Therefore, the organic particles are preferably kept in motion during most of the coating process, particularly during the entire coating process. The organic particles are preferably kept in motion during step (b), more preferably, the organic particles are kept in motion during step (b) and step (c). Step (a) can be operated so that it constitutes a drying step. This can be accomplished by purging the organic particles with dry air or an inert gas (such as nitrogen or argon) at room temperature or high temperature (e.g., 30° C. to 80° C.), for example, for 10 min to 2 h.

[0023] According to the invention, in step (b) the organic particles are contacted with a pretreatment compound in gaseous form. It has been surprisingly found that such a pretreatment compound leads to a reduced decomposition of sensitive organic compounds and at the same time reduces agglomeration during the method. If the organic particles already contain the pretreatment compound before starting the method, the same effect cannot be achieved. Without wishing to be bound by any theory, it is believed that the decomposition compound only needs to be on the surface of the particles and should not be present in the interior of the organic particles.

[0024] The pretreatment compound is water, an alcohol or a carboxylic acid. Alcohols include monohydric alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, isobutanol, tert-butanol; and diols such as ethylene glycol, propylene-1,2-diol, butane-1,2-diol, butane-1,4-diol, hexane-1,2-diol, hexane-1,4-diol. Carboxylic acids include monocarboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, lactic acid, pyruvic acid, glycine, alanine; and dicarboxylic acids such as oxalic acid, malonic acid, glutaric acid, adipic acid, maleic acid, fumaric acid, citric acid, hydroxymalonic acid, mesoxalic acid, tartaric acid, malic acid. Preferably, the pretreatment compound has a molecular weight of 500 g / mol or less, in particular 200 g / mol or less. Preferably, the pretreatment compound has a vapor pressure of at least 1 mbar at 80°C.

[0025] Preferably, the organic particles are contacted with the pretreatment compound for 1 s to 30 min, in particular 1 min to 10 min. Preferably, the organic particles are contacted with the pretreatment compound at a temperature of 0° C. to 150° C., more preferably 20° C. to 120° C., in particular 25° C. to 80° C. Preferably, the organic particles are contacted with the pretreatment compound at a pretreatment compound partial pressure of 1 mbar to 1 bar, more preferably 2 to 100 mbar, in particular 5 to 100 mbar. Preferably, the organic particles are contacted with a mixture of the gaseous pretreatment compound and an inert gas (e.g. nitrogen or argon). The mixture of the gaseous pretreatment compound and the inert gas may have a pressure of about ambient pressure, such as 0.8 to 1.2 bar. The pretreatment compound may be made gaseous by the techniques described for the metal- or semimetal-containing compounds described below. Preferably, any excess pretreatment compound is removed from the gaseous state after the organic particles have been contacted with the pretreatment compound and before the organic particles are contacted with the metal- or semimetal-containing compound. Such removal can be achieved by evacuation or purging, for example with an inert gas such as nitrogen or argon. Evacuation or purging may take from 10 s to 1 h, preferably from 1 to 45 min, in particular from 5 to 30 min.

[0026] According to the present invention, in step (c), the organic particles are contacted with a metal- or semi-metal-containing compound and a decomposition compound in a gaseous state in sequence at a first temperature. In sequence, it can be meant that the organic particles are first contacted with a metal- or semi-metal-containing compound and then with a decomposition compound. Therefore, a sequence is performed, which includes contacting the organic particles with a metal- or semi-metal-containing compound and contacting the organic particles with a decomposition compound. This sequence can be performed 1 to 500 times, preferably 2 to 100 times, for example 3 to 20 times or 10 to 50 times. Preferably, the organic particles are contacted with the metal- or semi-metal-containing compound for 10s to 1h, preferably 1 to 45min, and in particular 5 to 30min.

[0027] Preferably, before the organic particles are contacted with the decomposition compound, the residual gaseous metal-containing or semi-metal compound is removed. Preferably, before the organic particles are contacted with the metal-containing or semi-metal compound, the residual gaseous decomposition compound is removed. Removal can be achieved by evacuation or by purging with an inert gas (e.g., nitrogen or argon). Therefore, the sequence may include contacting the organic particles with a metal-containing or semi-metal compound, removing the residual metal-containing or semi-metal compound from the gas phase, contacting the organic particles with the decomposition compound and removing the residual decomposition compound from the gas phase. Evacuation or purging may take 10s to 1h, preferably 1 to 45min, particularly 5 to 30min.

[0028] Preferably, the metal- or semi-metal-containing compound is capable of reacting with the organic compound on the surface of the particles, i.e., capable of forming a permanent bond with the particles. The metal- or semi-metal-containing compound contains at least one metal or semi-metal atom. Metals include Li, Be, Na, Mg, Al, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Cs, Ba, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Bi. Semi-metals include B, Si, Ge, As, Sb, Se, Te. Preferably, the metal- or semimetal-containing compound contains Ti, Al, Si, Fe, Mg, Zn, Sn, Zr, or Hf. More than one metal- or semimetal-containing compound may be used simultaneously or successively. If more than one metal- or semimetal-containing compound is used, all metal- or semimetal-containing compounds may contain the same metal or semimetal or different metals or semimetals, preferably they contain different metals or semimetals.

[0029] Various metal or semimetal compounds that can be converted into a gaseous state are suitable. These compounds include metal or semimetal alkyls, such as dimethyl zinc or trimethyl aluminum; metal alkoxides, such as tetramethoxysilicon, tetraisopropoxy zirconium, tetraisopropoxy titanium or dimethylisopropoxy aluminum; metal or semimetal cyclopentadienyl complexes, such as pentamethylcyclopentadienyl-trimethoxytitanium or bis(ethylcyclopentadienyl)manganese; metal or semimetal carbenes, such as tri(neopentyl)neopentylene tantalum or bis(imidazolidinyl)ruthenium chloride; metal or semimetal halides, such as aluminum trichloride, silicon tetrachloride, pentachlorobenzene; The metal or semimetal compound preferably comprises a tantalum compound, a titanium tetrachloride, a molybdenum pentachloride, a germanium tetrachloride, a gallium trichloride, an arsenic trichloride or a tungsten hexachloride; a carbon monoxide complex, such as chromium hexacarbonyl or nickel tetracarbonyl; an amine complex, such as bis(tert-butylimino)-bis(dimethylamido)molybdenum, bis(tert-butylimino)bis(dimethylamido)tungsten or tetrakis(dimethylamido)titanium, di(isopropylamino)silane; a diketonate complex, such as tris(acetylacetonate)aluminum or bis(2,2,6,6-tetramethyl-3,5-heptanedione)manganese. Metal or semimetal alkyls are preferred, in particular trimethylaluminum. Preferably, the metal or semimetal compound has a molecular weight of up to 1000 g / mol, more preferably up to 800 g / mol, in particular up to 600 g / mol, such as up to 500 g / mol. Preferably, the metal or semimetal compound has a vapor pressure of at least 1 mbar at 80°C.

[0030] Preferably, the decomposition compound is capable of reacting with the metal- or semi-metal-containing compound and thereby forming a functional group that can react with a further metal- or semi-metal-containing compound. Various decomposition compounds are suitable, including: plasmas, such as oxygen plasma, hydrogen plasma, ammonia plasma, nitrous oxide or nitrogen plasma; oxidants, such as oxygen, oxygen radicals, ozone, nitrous oxide (N2O), nitric oxide (NO), nitrogen dioxide (NO2) or hydrogen peroxide; ammonia or ammonia derivatives, for example tert-butylamine, isopropylamine, dimethylamine, methylethylamine, or diethylamine; hydrazine or hydrazine derivatives, such as N,N-dimethylhydrazine; solvents, such as water, alkanes or carbon tetrachloride (tetrachlorocarbon); phosphorus compounds, such as phosphorus chloride, phosphane, trimethylphosphine, hexamethylphosphorus triamide (HMTP) or trimethylphosphonate; alcohols, including monohydric alcohols such as isopropanol or n-butanol and diols such as ethylene glycol, propylene glycol, butane-1,4-diol, hexane-1,6-diol; mercaptans, in particular mercaptans further containing hydroxyl groups, such as 4-mercaptophenol or 4-mercaptobenzyl alcohol; or boron compounds, such as borane. The choice depends on the chemical structure of the desired inorganic compound. For oxides, preference is given to using oxidants, plasmas or water, in particular oxygen, water, oxygen plasma or ozone. For nitrides, preference is given to using ammonia, hydrazine, hydrazine derivatives, nitrogen plasma or ammonia plasma. For borides, preference is given to using boron compounds. For carbides, preference is given to using alkanes or carbon tetrachloride. For carbide nitrides, preference is given to using a mixture comprising alkanes, carbon tetrachloride, ammonia and / or hydrazine. Preferably, the decomposition compound has a vapor pressure of at least 1 mbar at 80°C.

[0031] When in contact with the organic particles, the metal- or semi-metal-containing compound and the decomposition compound are in a gaseous state. They can be made gaseous, for example, by heating them to a high temperature. In any case, a temperature lower than the decomposition temperature of the metal- or semi-metal-containing compound or the decomposition compound must be selected. The decomposition temperature is the temperature at which the original metal- or semi-metal-containing compound or the decomposition compound begins to change its chemical structure and composition. Preferably, the heating temperature ranges from 0°C to 300°C, more preferably from 10°C to 200°C, even more preferably from 15°C to 150°C, particularly from 20°C to 100°C.

[0032] Another way to make metal-containing or semimetallic compound or decomposition compound become gaseous is direct liquid injection (DLI), as described in US2009 / 0 226 612A1 for example. In this method, typically metal-containing or semimetallic compound or decomposition compound is dissolved in solvent and sprayed in carrier gas or vacuum. If the vapor pressure and temperature of metal-containing or semimetallic compound or decomposition compound are high enough and pressure is low enough, metal-containing or semimetallic compound or decomposition compound becomes gaseous. Various solvents can be used, provided that metal-containing or semimetallic compound or decomposition compound show enough solubility in the solvent, such as at least 1g / l, preferably at least 10g / l, more preferably at least 100g / l. Examples of these solvents are coordination solvents (such as tetrahydrofuran, dioxane, diethoxyethane, pyridine) or non-coordinating solvents (such as hexane, heptane, benzene, toluene or xylene). Solvent mixtures are also suitable.

[0033] Alternatively, the metal- or semi-metal-containing compound or the decomposition compound can be made gaseous by direct liquid evaporation (DLE), as described, for example, by J. Yang et al. (Journal of Materials Chemistry C, Vol. 3 (2015), pp. 12098-12106). In this method, the metal- or semi-metal-containing compound is mixed with a solvent (e.g., a hydrocarbon such as tetradecane) and heated to a temperature below the boiling point of the solvent. By evaporating the solvent, the metal- or semi-metal-containing compound or the decomposition compound is made gaseous. This method has the advantage that particulate contamination is not formed.

[0034] It is preferred to make the metal- or semi-metal-containing compound or the decomposition compound gaseous under reduced pressure. In this way, the method can usually be carried out at a lower heating temperature, so that the decomposition of the metal- or semi-metal-containing compound is reduced. It is also possible to use supercharging to push the gaseous metal- or semi-metal-containing compound or the decomposition compound toward the solid substrate. Preferably, a pressure of about ambient pressure is used, such as 0.8 to 1.2 bar. For this purpose, an inert gas (such as nitrogen or argon) is usually used as a carrier gas. Preferably, the partial pressure of the metal- or semi-metal-containing compound or the decomposition compound is 100 to 10 -3 mbar, more preferably 10 mbar to 0.01 mbar, especially 5 to 0.05 mbar, such as 1 to 0.1 mbar.

[0035] The metal- or semimetal-containing compounds and decomposition compounds used in the method according to the invention are used in high purity to achieve the best results. High purity means that the substances used contain at least 90 wt.-%, preferably at least 95 wt.-%, more preferably at least 98 wt.-%, in particular at least 99 wt.-% of metal- or semimetal-containing compounds and decomposition compounds. The purity can be determined by elemental analysis according to DIN 51721 (Prüfung fester Brennstoffe-Bestimmung des Gehaltes an Kohlenstoff und Wasserstoff-Verfahren nach Radmacher-Hoverath [Testing of solid fuels - Determination of carbon and hydrogen content - Radmacher-Hoverath method], August 2001).

[0036] Contacting the organic particles with the metal- or semimetal-containing compound and the decomposition compound in step (c) can be carried out at a temperature of 0° C. to 150° C., preferably 20° C. to 120° C., more preferably 40° C. to 100° C., and particularly 50° C. to 80° C. The temperature refers to the temperature of the organic particles when they are contacted with the metal- or semimetal-containing compound and the decomposition compound in step (c). The temperature of the organic particles is typically controlled by adjusting the temperature of the gas and the apparatus surrounding the organic particles.

[0037] If the sequence in step (c) comprising contacting the organic particles with a metal- or semimetal-containing compound and contacting the organic particles with a decomposition compound is performed more than once, the same temperature or different temperatures may be used for each sequence. Preferably, the first part of the sequences is carried out at a first temperature and the second part of the sequences is carried out at a second temperature, wherein the second temperature is at least 20° C., more preferably at least 25° C., even more preferably at least 30° C., in particular at least 40° C. higher than the first temperature. It has been surprisingly found that such a temperature difference makes the process even more suitable for organic particles containing sensitive compounds and leads to a further reduction in the degree of agglomeration.

[0038] The same metal- or semimetal-containing compound or different metal- or semimetal-containing compounds, preferably different metal- or semimetal-containing compounds, can be used in each sequence of step (c). The same decomposition compound or different decomposition compounds, preferably different decomposition compounds, can be used in each sequence of step (c).

[0039] The method of the present invention may comprise the steps in the following order:

[0040] (a) causing particles containing organic compounds to move relative to each other,

[0041] (b) contacting the organic particles with a pretreatment compound in a gaseous state, wherein the pretreatment compound is water, an alcohol or a carboxylic acid, and

[0042] (c1) contacting the organic particles with a first metal- or semimetal-containing compound and a first decomposition compound in a gaseous state in sequence at a first temperature, and

[0043] (c2) contacting the organic particles in sequence with a second metal- or semimetal-containing compound and a second decomposition compound in a gaseous state at a second temperature.

[0044] Preferably, the reaction enthalpy of the reaction of the first metal- or semi-metal-containing compound with the first decomposition compound is lower than the reaction enthalpy of the reaction of the second metal- or semi-metal-containing compound with the second decomposition compound, preferably the reaction enthalpy of the reaction of the first metal- or semi-metal-containing compound with the first decomposition compound is 20% lower than the reaction enthalpy of the reaction of the second metal- or semi-metal-containing compound with the second decomposition compound, in particular the reaction enthalpy of the reaction of the first metal- or semi-metal-containing compound with the first decomposition compound is 30% lower than the reaction enthalpy of the reaction of the second metal- or semi-metal-containing compound with the second decomposition compound. The reaction enthalpy of the reaction of the first metal- or semi-metal-containing compound with the first decomposition compound at 25° C. may be less than 800 kJ / mol, in particular less than 600 kJ / mol. The reaction enthalpy of the reaction of the second metal- or semi-metal-containing compound with the second decomposition compound at 25° C. may be greater than 800 kJ / mol, in particular greater than 1000 kJ / mol.

[0045] The reaction enthalpy can be obtained by calculating the difference between the standard enthalpies of formation of the reagents and products of the reaction between the metal- or semimetal-containing compound and the decomposition compound. The standard enthalpies of formation can be found in various databases, such as the NIST Chemistry WebBook (https: / / webbook.nist.gov / chemistry) or the Detherm database (https: / / i-systems.dechema.de / detherm / mixture.php).

[0046] When the first decomposition compound and the second decomposition compound are the same, the reactivity of the first metal- or semi-metal-containing compound may be lower than the reactivity of the second metal- or semi-metal-containing compound. For example, the first metal- or semi-metal-containing compound may be one of diethylzinc, silicon tetrachloride, tetrakis(dimethylamino)titanium(IV) or titanium tetrachloride. The second metal- or semi-metal-containing compound may be one of trimethylaluminum or dimethylisopropoxyaluminum.

[0047] When the first metal- or semimetal-containing compound and the second metal- or semimetal-containing compound are the same, the reactivity of the first decomposition compound with the first metal- or semimetal-containing compound may be lower than the reactivity of the second decomposition compound with the second metal- or semimetal-containing compound. For example, the first decomposition compound may be isopropanol and the second decomposition compound may be water.

[0048] When the first metal- or semimetal-containing compound and the second metal- or semimetal-containing compound are different from each other, the reactivity of the first decomposition compound with the first metal- or semimetal-containing compound may be lower than the reactivity of the second decomposition compound with the second metal- or semimetal-containing compound, and the first decomposition compound is different from the second decomposition compound. For example, the first metal- or semimetal-containing compound may be diethyl zinc, the first decomposition compound may be water, the second metal- or semimetal-containing compound may be trimethyl aluminum, and the second decomposition compound may be ozone.

[0049] Preferably, the sequence in step (c2) is performed more frequently than the sequence in step (c1), more preferably, the sequence in step (c2) is performed 1.5 times the sequence in step (c1), in particular the sequence in step (c2) is performed twice the sequence in step (c1).

[0050] The method of the present invention produces organic particles containing a core and a shell surrounding the core. The core contains an organic compound as described above for the method. Preferably, the core has a weight average particle size of 0.5 to 1000 μm, more preferably 1 to 200 μm, even more preferably 2 to 100 μm, in particular 3 to 50 μm, for example 5 to 20 μm. The average particle size is preferably measured by light scattering.

[0051] The shell may include an inner portion and an outer portion, wherein the inner portion and the outer portion contain a metal or semi-metal. Metals include Li, Be, Na, Mg, Al, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Cs, Ba, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Bi. Semi-metals include B, Si, Ge, As, Sb, Se, Te. Preferably, the compound containing a metal or semi-metal contains Ti, Al, Fe, Mg, Zn, Sn, Zr, or Hf. The shell may contain an inorganic compound, such as a metal or semimetal oxide, nitride, boride, carbide, or carbide nitride of a metal or semimetal. The inorganic compound may contain one metal or semimetal or more than one metal or semimetal. Preferably, the shell contains at least 90 wt.-%, even more preferably at least 95 wt.-%, in particular at least 98 wt.-% of inorganic compound.

[0052] The inner part of the shell can have a lower refractive index than the outer part of the shell, particularly if the inner part of the shell is made at a lower temperature than the outer part of the shell. Without wishing to be bound by any theory, it is believed that the lower temperature of the inner part of the shell causes a lower refractive index, which may be due to incomplete chemical conversion and therefore lower crystallinity and more crystal defects. The dependence of the refractive index on the film deposition temperature has been shown by MD Groner et al. in Chemistry of Materials [Chemistry of Materials], Vol. 16 (2004), pp. 639-645. The refractive index can be measured by phase contrast imaging (e.g., by Zernike phase contrast microscopy), differential interference contrast microscopy (DIC) or interferometry. Preferably, the refractive index of the inner part of the shell is 0.05 higher than the refractive index of the outer part of the shell, and the refractive index of the inner part of the shell is 0.1 higher than the refractive index of the outer part of the shell.

[0053] The inner part of the shell may have a lower density than the outer part of the shell. Preferably, the density of the inner part of the shell is 2% lower than the density of the outer part of the shell, in particular the density of the inner part of the shell is 5% lower than the density of the outer part of the shell.

[0054] Preferably, the shell is conformal to the core. Preferably, the shell has a thickness of 0.5 to 100 nm, more preferably 1 to 50 nm, particularly 2 to 20 nm. The inner portion of the shell may be thinner, thicker or thicker than the outer shell. The inner shell may have a thickness of 0.2 to 100 nm, preferably 0.5 to 50 nm, particularly 1 to 15 nm. The outer shell may have a thickness of 0.2 to 100 nm, preferably 0.5 to 50 nm, particularly 1 to 15 nm.

[0055] The organic particles may be included in the composition. The composition may be a composition used as an agricultural chemical, particularly if the particles contain insecticides, herbicides or fungicides. In this case, the composition is preferably a conventional formulation type of an agricultural chemical composition, such as an aqueous liquid capsule formulation (e.g., CS, ZC), a paste, a lozenge, a wettable powder or dust (e.g., WP, SP, WS, DP, DS), a compressed tablet (e.g., BR, TB, DT), a granule (e.g., WG, SG, GR, FG, GG, MG), an insecticide formulation (e.g., LN), and a gel formulation (e.g., a gel formulation for treating plant propagation materials such as seeds) (e.g., GF). These and other composition types are defined in "Catalogue of pesticide formulation types and international coding system", Technical Monograph, Issue 2, May 2008, 6th edition, CropLife International.

[0056] These compositions are prepared in a known manner, as described by Mollet and Grubemann, Formulation technology, Wiley VCH, Weinheim, 2001; or Knowles, New developments in crop protection product formulation, Agrow Reports DS 243, T&F Informa, London, 2005.

[0057] Preferably, the composition contains one or more adjuvants selected from solvents, liquid carriers, solid carriers or fillers, surfactants, dispersants, emulsifiers, wetting agents, adjuvants, solubilizers, penetration enhancers, protective colloids, adhesives, thickeners, humectants, repellents, attractants, feeding stimulants, compatibilizers, bactericides, antifreeze agents, defoamers, colorants, tackifiers and adhesives.

[0058] Suitable solvents and liquid carriers are water and organic solvents, such as medium to high boiling mineral oil fractions, for example kerosene, diesel; oils of vegetable or animal origin; aliphatic, cyclic and aromatic hydrocarbons, for example toluene, paraffins, tetralin, alkylated naphthalenes; alcohols, for example ethanol, propanol, butanol, benzyl alcohol, cyclohexanol; glycols; DMSO; ketones, for example cyclohexanone; esters, for example lactates, carbonates, fatty acid esters, γ-butyrolactone; fatty acids; phosphonates; amines; amides, for example N-methylpyrrolidone, fatty acid dimethylamides; and mixtures thereof.

[0059] Suitable solid carriers or fillers are mineral earths, for example silicates, silica gel, talc, kaolin, limestone, lime, chalk, clay, dolomite, diatomaceous earth, bentonite, calcium sulfate, magnesium sulfate, magnesium oxide; polysaccharide powders, for example cellulose, starch; fertilizers, for example ammonium sulfate, ammonium phosphate, ammonium nitrate, urea; products of plant origin, for example cereal flour, bark flour, wood flour, nut shell flour and mixtures thereof.

[0060] Suitable surfactants are surface-active compounds such as anionic, cationic, nonionic and amphoteric surfactants, block polymers, polyelectrolytes, and mixtures thereof. Such surfactants can be used as emulsifiers, dispersants, solubilizers, wetting agents, penetration enhancers, protective colloids, or adjuvants. Examples of surfactants are listed in McCutcheon's, Vol. 1: Emulsifiers & Detergents, McCutcheon's Directories, Glen Rock, USA, 2008 (International or North American Edition).

[0061] Suitable anionic surfactants are alkali metal salts, alkaline earth metal salts or ammonium salts of sulfonates, sulfates, phosphates, carboxylates and mixtures thereof. The example of sulfonates is alkyl aryl sulfonates, diphenyl sulfonates, α-olefin sulfonates, lignin sulfonates, fatty acids and oily sulfonates, sulfonates of ethoxylated alkylphenols, sulfonates of alkoxylated arylphenols, sulfonates of condensed naphthalene, dodecyl- and tridecylbenzene sulfonates, sulfonates of naphthalene and alkylnaphthalene, sulfosuccinates or sulfosuccinamates. The example of sulfates is sulfates of fatty acids and oily sulfates, sulfates of ethoxylated alkylphenols, sulfates of alcohols, sulfates of ethoxylated alcohols or sulfates of fatty acid esters. The example of phosphates is phosphoric acid esters. The example of carboxylates is alkyl carboxylates and carboxylated alcohols or alkylphenol ethoxylates.

[0062] Suitable nonionic surfactants are alkoxylates, N-substituted fatty acid amides, amine oxides, esters, sugar-based surfactants, polymeric surfactants, and mixtures thereof. Examples of alkoxylates are compounds such as alcohols, alkylphenols, amines, amides, arylphenols, fatty acids or fatty acid esters that have been alkoxylated by 1 to 50 equivalents. Oxyethylene oxide and / or propylene oxide can be used for alkoxylation, preferably ethylene oxide. Examples of N-substituted fatty acid amides are fatty acid glucamides or fatty acid alkanolamides. Examples of esters are fatty acid esters, glycerides or monoglycerides. Examples of sugar-based surfactants are sorbitan, ethoxylated sorbitan, sucrose and glucose esters or alkyl polyglucosides. Examples of polymeric surfactants are homopolymers or copolymers of vinyl pyrrolidone, vinyl alcohol or vinyl acetate.

[0063] Suitable cationic surfactants are quaternary ammonium surfactants, for example quaternary ammonium compounds with one or two hydrophobic groups or salts of long chain primary amines. Suitable amphoteric surfactants are alkyl betaines and imidazolines. Suitable block polymers are AB or ABA type block polymers comprising blocks of polyethylene oxide and polypropylene oxide, or ABC type block polymers comprising alkanol, polyethylene oxide and polypropylene oxide. Suitable polyelectrolytes are polyacids or polybasics. The example of polyacids is an alkali metal salt of polyacrylic acid or a polyacid comb polymer. The example of a polybasic base is polyvinylamine or polyvinylamine.

[0064] Suitable adjuvants are compounds which themselves have negligible or even no pesticidal activity and which improve the biological performance of compound I on the target. Examples are surfactants, mineral or vegetable oils and other adjuvants. Further examples are listed by Knowles, Adjuvants and additives, Agrow Reports DS256, T&F Informa UK, 2006, Chapter 5.

[0065] Suitable thickeners are polysaccharides (e.g., xanthan gum, carboxymethyl cellulose), inorganic clays (organically modified or unmodified), polycarboxylates, and silicates. Suitable bactericides are bronopol and isothiazolinone derivatives, such as alkylisothiazolinone and benzisothiazolinone. Suitable antifreeze agents are ethylene glycol, propylene glycol, urea, and glycerol. Suitable defoamers are salts of silicone, long-chain alcohols, and fatty acids. Suitable colorants (e.g., red, blue, or green) are low water-soluble pigments and water-soluble dyes. Examples are inorganic colorants (e.g., iron oxide, titanium oxide, hexacyanoferrate) and organic colorants (e.g., alizarin colorants, azo colorants, and phthalocyanine colorants). Suitable tackifiers or adhesives are polyvinyl pyrrolidone, polyvinyl acetate, polyvinyl alcohol, polyacrylates, biowax or synthetic wax, and cellulose ethers.

[0066] The composition may be a composition for use as a cleaning composition, particularly if the particles contain a cleaning additive. In this case, preferably, the composition contains one or more of a surfactant, a bleaching agent, a bleaching catalyst, a bleaching activator, a corrosion inhibitor, a builder, an enzyme, a zinc salt.

[0067] The surfactant can be selected from anionic surfactants, amphoteric surfactants or nonionic surfactants, preferably nonionic surfactants. Anionic surfactants are C8-C 18 -Alkali metal and ammonium salts of alkyl sulfates, C8-C 18 -Alkali metal and ammonium salts of fatty alcohol polyether sulfates, ethoxylated C4-C 12 -Alkali metal and ammonium salts of sulfuric acid half esters of alkylphenols (ethoxylation: 1 to 50 mol ethylene oxide / mol), C 12 -C 18 Sulfonic fatty acid alkyl esters (such as C 12 -C 18 sulfonic acid methyl esters) of alkali metal and ammonium salts, and C 12 -C 18 -Alkali metal and ammonium salts of alkylsulfonic acids and C 10 -C 18- alkali metal and ammonium salts of alkylarylsulfonic acids, sodium or potassium salts of stearic acid, oleic acid, palmitic acid, ether carboxylates and alkyl ether phosphates. Amphoteric surfactants are those which carry a positive and a negative charge in the same molecule under the conditions of use. Preferred examples of amphoteric surfactants are so-called betaine surfactants. Many examples of betaine surfactants carry one quaternary nitrogen atom and one carboxylic acid group per molecule. A particularly preferred example of an amphoteric surfactant is cocamidopropyl betaine (lauramidopropyl betaine). Nonionic surfactants may be alkoxylated alcohols, diblock and multiblock copolymers of ethylene oxide and propylene oxide and reaction products of sorbitan with ethylene oxide or propylene oxide, alkyl polyglycosides (APGs), hydroxyalkyl mixed ethers and amine oxides.

[0068] The bleaching agent may be selected from chlorine bleach and peroxide bleach, and the peroxide bleach may be selected from inorganic peroxide bleach and organic peroxide bleach. Preferred are inorganic peroxide bleaches selected from alkali metal percarbonates, alkali metal perborates and alkali metal persulfates. An example of an organic bleach is a percarboxylic acid. The composition may contain 3 to 10 wt.-% of bleach.

[0069] The bleach catalyst can be selected from transition metal salts or transition metal complexes which promote bleaching, such as, for example, manganese-, iron-, cobalt-, ruthenium- or molybdenum-salen complexes or carbonyl complexes. Manganese, iron, cobalt, ruthenium, molybdenum, titanium, vanadium and copper complexes with nitrogen-containing tripod-type ligands and also cobalt-, iron-, copper- and ruthenium-amine complexes can also be used as bleach catalysts.

[0070] The bleach activator may be selected from N-methylmorpholinium-acetonitrile salts ("MMA salts"), trimethylammonium acetonitrile salts, N-acylimides such as, for example, N-nonanoylsuccinimide, 1,5-diacetyl-2,2-dioxohexahydro-1,3,5-triazine ("DADHT") or quaternary ammonium nitrile salts (trimethylammonium acetonitrile salts), tetraacetylethylenediamine (TAED) and tetraacetylhexanediamine.

[0071] Corrosion inhibitors are typically compounds that inhibit metal corrosion. Examples of suitable corrosion inhibitors are triazoles, in particular benzotriazole, bisbenzotriazole, aminotriazole, alkylaminotriazole, and also phenol derivatives, such as, for example, hydroquinone, pyrocatechol, hydroxyhydroquinone, gallic acid, phloroglucinol or pyrogallol. Preferably, the composition comprises 0.1 to 1.5 wt.-% of corrosion inhibitor.

[0072] The builder can be selected from organic and inorganic builders. Examples of suitable inorganic builders are sodium sulfate or sodium carbonate or silicates, in particular sodium disilicate and sodium metasilicate, zeolites, phyllosilicates, in particular those with the formula α-Na2Si2O5, β-Na2Si2O5 and δ-Na2Si2O5, as well as fatty acid sulfonates, α-hydroxypropionic acid, alkali metal malonates, fatty acid sulfonates, alkyl and alkenyl disuccinates, tartrate diacetate, tartrate monoacetate, oxidized starch, and polymer builders, such as polycarboxylates and polyaspartic acid. Examples of organic builders are especially polymers and copolymers. In one embodiment of the invention, the organic builders are selected from polycarboxylates, such as alkali metal salts of (meth) acrylic acid homopolymers or (meth) acrylic acid copolymers. Preferably, the composition contains 10 to 70 wt.-% of a builder.

[0073] The enzyme may be selected from the group consisting of lipases, hydrolases, amylases, proteases, cellulases, esterases, pectinases, lactases and peroxidases.Preferably, the composition contains 0.1 to 5 wt.-% of enzymes.

[0074] The zinc salt may be selected from water-soluble zinc salts and water-insoluble zinc salts. Water-insoluble is used to refer to those zinc salts having a solubility of 0.1 g / l or less in distilled water at 25° C. Correspondingly, zinc salts having a higher solubility in water are referred to as water-soluble zinc salts in the context of the present invention. Preferably, the zinc salt is selected from zinc benzoate, zinc gluconate, zinc lactate, zinc formate, ZnCl , ZnSO , zinc acetate, zinc citrate, Zn(NO ) , Zn(CH SO ) , and zinc gallate, preferably ZnCl , ZnSO , zinc acetate, zinc citrate, Zn(NO ) , Zn(CH SO ) , and zinc gallate, ZnO, aqueous ZnO, Zn(OH) , and ZnCO .

[0075] Examples

[0076] Example 1 (the present invention)

[0077] Fluopyram powder was charged into a fluidized bed reactor with a volume of 300 ml. The powder was dried at 50 ° C for 1 h under N2 with a flow rate of 700 sccm. After drying, the powder was exposed to a controlled amount of water vapor for two minutes through an ALD dosing unit at a precursor dosing rate of 75 sccm. After the time, the water vapor was removed by purging with nitrogen for 5 minutes. After this pretreatment, 20 trimethylaluminum (TMA) / H2O ALD cycles were performed by exposing the powder to TMA vapor and water vapor with the following dosing times:

[0078] TMA: 10min, 50sccm

[0079] Purge: 15min, 100sccm

[0080] H2O: 5min, 75sccm

[0081] Purge: 15min, 100sccm

[0082] A free-flowing white powder was obtained.

[0083] Example 2 (Comparison)

[0084] Example 1 was repeated except that the fluopyram powder was not exposed to water vapor before exposing it to TMA and water vapor. Strong agglomeration and yellowing of the powder was observed.

Claims

1. A method for preparing coated organic particles, the method comprising the steps in the following order: (a) causing particles containing organic compounds to move relative to each other, (b) contacting the organic particles with a pretreatment compound in a gaseous state, wherein the pretreatment compound is water, an alcohol or a carboxylic acid, and (c) contacting the organic particles sequentially with a metal- or semi-metal-containing compound and a decomposition compound in a gaseous state.

2. The method according to claim 1, wherein: The pretreatment compound has a vapor pressure of at least 1 mbar at 80°C.

3. The method according to claim 1 or 2, wherein: The organic particles are fluidized.

4. The method according to any one of claims 1 to 3, wherein: In step (b) the organic particles are contacted with the pretreatment compound for 1 to 30 min.

5. The method according to any one of claims 1 to 4, wherein: The metal- or semi-metal-containing compound contains Ti, Al, Si, Fe, Mg, Zn, Sn, Zr, or Hf.

6. The method according to any one of claims 1 to 5, wherein: The organic particles contain agricultural chemicals, pharmaceuticals or cleaning additives.

7. The method according to any one of claims 1 to 6, wherein: The organic particles have a weight average particle size of 2 to 50 μm.

8. The method according to any one of claims 1 to 7, wherein: The organic particles are dried in step (a) by blowing the organic particles at 30° C. to 80° C. for 10 min to 2 h.

9. The method according to any one of claims 1 to 8, wherein: In step (c), the sequence of contacting the organic particles with a metal- or semi-metal-containing compound, removing residual metal- or semi-metal-containing compound from the gas phase, contacting the organic particles with a decomposition compound and removing residual decomposition compound from the gas phase is performed 2 to 100 times.

10. The method according to any one of claims 1 to 9, wherein: Step (c) comprises (c1) contacting the organic particles with a first metal- or semimetal-containing compound and a first decomposition compound in a gaseous state in sequence at a first temperature, and (c2) contacting the organic particles with a second metal- or semimetal-containing compound and a second decomposition compound in a gaseous state in sequence at a second temperature, The second temperature is at least 20° C. higher than the first temperature.

11. The method according to any one of claims 1 to 10, wherein: Step (c) comprises (c1) contacting the organic particles with a first metal- or semimetal-containing compound and a first decomposition compound in a gaseous state in sequence at a first temperature, and (c2) contacting the organic particles with a second metal- or semimetal-containing compound and a second decomposition compound in a gaseous state in sequence at a second temperature, The reaction enthalpy of the reaction between the first metal- or semi-metal-containing compound and the first decomposition compound is lower than the reaction enthalpy of the reaction between the second metal- or semi-metal-containing compound and the second decomposition compound.

12. The method according to claim 10 or 11, wherein: The sequence in step (c2) is performed more frequently than the sequence in step (c1).