SK11732000A3 - Water-dispersible flake compositions - Google Patents

Abstract

A water-dispersible flake comprises a plurality of microcapsules or microparticles containing one or more encapsulated ingredients, for example a pesticide such as a herbicide or an insecticide, wherein the microcapsules or microparticles are held together in flake form by spacer material such as a nonencapsulated pesticide and/or one or more surfactants. The flake may be prepared by (a) mixing an aqueous suspension of the microcapsules or microparticles with spacer material and/or a surfactant to form a dispersion (b) drying the dispersion by thin-layer drying on a heated surface and (c) removing the dried product of step (b) from the heated surface to form flakes.

Description

Water-dispersible flake compositions

Technical field

The invention relates to a water-dispersible flocculent composition comprising a plurality of microcapsules or microparticles interconnected by a spacer material. The invention also relates to a process for the manufacture of these flakes.

BACKGROUND OF THE INVENTION

There is considerable demand in the agrochemical industry for active ingredient formulations that are safe, effective and economical. In this regard, pesticidal formulations existing in dry form, which can be rapidly dispersed in water, appear to be advantageous.

The advantage of dry formulations is their easier and less expensive release from the container in which they are delivered. Thus, the dry pesticide materials can be transported in containers made of paper or in water-soluble plastic bags. Another economic advantage of dry formulations is the substantial reduction or elimination of the aqueous or organic solvents used in other types of formulations. The advantage of these formulations is, last but not least, a smaller volume of material and thus easier handling.

For many active ingredients (both liquid and solid), microscopic encapsulation is a practical way of using solid formulations in the manufacture of stable aqueous sprayable suspensions. The use of microscopic encapsulation allows for the use of microscopic encapsulation. in many cases, reduce toxicity and / or prolong the effectiveness of the encapsulated active material. Further, the microscopic encapsulation can be effectively used to delay decomposition or use of pesticides that would otherwise rapidly lose their effectiveness. The microscopic encapsulation further provides a potential means of combining substances that are otherwise incompatible with each other.

True microscopic capsules are essentially particles that comprise a polymeric shell or packages surrounding one or more encapsulated ingredients. Another form of encapsulation involves making a polymer matrix that physically contains one or more dispersed dissolved or otherwise entrapped components in the polymer. The smaller particles are obtained by physically breaking the polymer matrix. The small particles obtained in this way are generally referred to as "microparticles and are produced in similar sizes and in similar size ranges as microscopic capsules. Solid formulations of microscopically encapsulated pesticides include extrusion or spray drying products. However, extrusion can cause the capsules to break and, due to the large amount of water required in this type of processing, does not allow the production of capsules with a higher concentration of active pesticide. In the manufacture of dry formulations, it is sought to produce formulations that are of sufficient size and structural integrity and that minimize potential dust problems.

US Patents 4,936,901 and 5,354,742 disclose generally spherical aggregates formed by microscopic capsules of encapsulated pesticides. These spherical granules exhibit many desirable economic and safety properties. However, the production of spray-dried materials can be economical

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it is difficult and generally desirable to produce other solid forms of microscopically encapsulated pesticidally active ingredients.

Accordingly, it is an object of the invention to provide a new dry formulation of a microscopically encapsulated component or microparticles comprising such a component that provides unexpected economic and safety benefits. The scope of the invention is not limited to products containing pesticides. Microscopic encapsulation and microparticles are also widely used for other materials where dry formulations may have similar advantages to pesticide formulations.

SUMMARY OF THE INVENTION

In one aspect, the invention relates to a water dispersible flake composition comprising a plurality of microscopic capsules or microparticles comprising one or more ingredients, said microscopic capsules or microparticles being held in flake form by a spacer material and / or one or more surfactants.

In another aspect, the invention is directed to a method of making water-dispersible flakes, each of said flakes comprising a plurality of microscopic capsules or microparticles that are held in flake form by a spacer material and / or one or more surfactants. :

a) mixing the aqueous suspension of microcapsules or microparticles with the spacer and / or one or more surfactants to form a suspension of the microcapsules or microparticles to form a surfactant; E) dispersions;

b) drying the dispersion in a thin layer on a heated surface; and

c) removing the dried product of step (b) from the heated surface to form flakes.

The compositions according to the invention can be stored in a larger volume due to their flocculent form and, since the flakes have fewer contact points than generally spherical granules, the likelihood of forming a compact whole, or solid blocks of material, is reduced and agglomeration of individual particles occurs.

The invention relates to water-dispersible flakes comprising a plurality of microscopic capsules or microparticles which are held together in the form of flakes by means of a spacer material and / or one or more surfactants.

The term "flake" as used herein includes a composition having a maximum length to thickness ratio greater than about 5: 1. This ratio is generally from about 5: 1 to 1000: 1, preferably from about 10: 1 to 100: 1. The flakes of the invention generally have a maximum thickness of about 0.05 mm to 2.0 mm, preferably about 0.1 mm to 1.0 mm.

The microcapsules formulated in the flake of the present invention consist of a core comprising a liquid active material and a polymeric sheath that encapsulates the core. The liquid core should be substantially insoluble or immiscible with water. It may consist of a single liquid ······························ Material or one or more active liquid or solid materials dissolved and / or suspended in an inert solvent, which in extreme cases is only slightly soluble in water. In this case, it is necessary that the liquid or solid solute remain predominantly in the organic phase.

The encapsulated material can be selected from many types of materials that are suitable for encapsulation, such as pharmaceuticals, biocides, cosmetics, dyes, hormones, repellents, growth regulators, pesticides, and others. While the invention will be described by way of example of compositions containing pesticides for simplicity, it can also be applied to all other substances mentioned above. If the encapsulated material is a pharmaceutical, then the flake components should be suitable for pharmaceutical compositions.

Pesticidal liquids and suspended solids suitable for encapsulation or microparticle production include chemical-biological agents such as herbicides, insecticides, fungicides, nematicides, bactericides, anti-rodent preparations, anti-mollusc preparations, acaricides and anti-larval preparations. . Non-pesticide materials used for pest control or other related activities, such as pest control in agriculture, households, commercial or industrial areas for which the invention is suitable include animal, insect and bird repellents, plant growth regulators, insect growth regulators, fertilizers, pheromones, lures and baits, flavorings and fragrances.

Illustrative herbicides are α-chloro-2 ', 6'-diethyl-N-methoxymethylacetanilide (alachlor); N-butoxymethyl-α-chloro-2 ', 6'6

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- diethylacetanilide (butachlor); 2'-methyl-6'-ethyl-N- (1-methoxy-2-propyl) -2-chloroacetanilide (metolachlor); 2'-tert-butyl-2-chloro-N-methoxymethyl-6'-methylacetanilide; α-chloro-N- (2-methoxy-6-methylphenyl) -N- (1-methylethoxymethyl) acetamide; α-chloro-N- (ethoxymethyl) -N- [2-methyl-6-trifluoromethyl) phenyl] acetamide; α-chloro-N-methyl-N- [2-methyl-6- (3-methylbutoxyphenyl) acetamide; α-chloro-N-methyl-N- (2-methyl-6-propoxyphenyl) acetamide; butoxy-6-methylphenyl) -2-chloro-N-methylacetamide, N- (2,6-dimethylphenyl) -N- (1-pyrazolylmethyl) chloroacetanilide (metazochloro), N, N-dialyl-2-chloroacetamide (allidochloro); (2,4-Dichloro-phenoxy) -acetic acid isobutyl ester 2-chloro-N- (ethoxymethyl) -6'-ethyl-o-acetotoluidide (acetochloro); 1- (1-cyclohexen-1-yl) -3- (2- fluorophenyl) -1-methyl urea S-2,3,3-trichloralyldiisopropylthiocarbamate (triallate) S-2,3-dichloralyldiisopropylthiocarbamate (diallat) α, α, α-trifluoro-2,6-dinitro-N, N-dipropyl - p-toluidine (trifluralin) 2- (2-chlorophenyl) methyl-4,4-dimethyl-3-isoxazolidinone (clomazone) 3,5-pyridinedicarbothioic acid;

2- (difluoromethyl) -4- (2-methylpropyl) -6- (trifluoromethyl) -S, S-dimethyl ester; 3-pyridinecarboxylic acid; 2- (difluoromethyl) -5- (4,5-dihydro-2-thiazolyl) -4- (2-methylpropyl) -6- (trifluoromethyl) methyl ester; 3-pyridinecarboxylic acid; 2- (difluoromethyl) -4- (2-methylpropyl) -5- (1H-pyrazol-1-ylcarbonyl) -6- (trifluoromethyl) methyl ester; 5-methyl-4-methoxycarbonyl-3- (methoxycarbonyl-phenoxy) pyrazole; and 5-methyl-4-methoxycarbonyl-3- (3'-methoxyphenoxy) pyrazole.

Other herbicides include S-ethyl-N-cyclohexyl-N-ethylthiocarbamate (cycloate); S-ethylhexahydro-1H-azepine-1-carbothioate (molinate); S-ethyldipropylthiocarbamate (EPTC); S-4-chlorobenzyldiethylthiocarbamate (bentiocarb); S-ethyldiisobutylthiocarbamate (butylate); S-benzyl di-sec-butylthiocarbamate; S-propyldipropylthiocarbamate (vernolate); S-propylbutylethylthiocarbamate (pe7

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Bulau); S-benzyl-N-ethyl-N- (1,2-dimethylpropyl) thiocarbamate (esprocarb); S-benzyldipropylthiocarbamate (prosulfocarb); N- (2-mercaptoethyl) benzenesulfonamide S- (O, O-diisopropylphosphorothioate) ester (bensulide); N-benzyl-N-isopropyltrimethylacetamide (butam); 2-chloralyldiethyldithiocarbamate (CDEC); 2-sec-butyl-4,6-dinitrophenol (dinoseb); 2,6-dinitro-N, N-dipropylcumidine (isopropalin); N- (cyclopropylmethyl) -α, α, α, -trifluoro-2,6-dinitro-N-propyl-p-toluidine (profluralin);

2- (1,2-dimethylpropylamino) -4-ethylamino-6-methylthio-1,3,5-triazine (dimetametryn); 2-ethyl-5-methyl-5- (2-methyl-benzyloxy) -1,3-dioxane; 2- (2'-nitro-4'-methylsulfonylbenzoyl) -1,3-cyclohexanedione (mesotrione); and 2- (2-chloro-4-methylsulfonylbenzoyl) -1,3-cyclohexanedione (sulcotrione).

Illustrative insecticides are: S-tert-butylthiomethyl-O, O-diethylphosphorothioate (terbufos); O, O-diethyl-O-2-isopropyl-6-methylpyridimidin-4-ylphosphorothioate (diazinone); O, O-diethyl S-2-ethylthioethyl phosphorothioate (disulfotone); S-chloromethyl-O, O-diethylphosphorothioate (chlorphephos); O-ethyl-S, S-dipropylphosphorothioate (etoprofos); O, O-diethyl-S-ethylthiomethylphosphorothioate (forate), O- (4-bromo-2-chlorophenyl) -O-ethyl-S-propylphosphorothioate (profenophos); S-1,2-di (ethoxycarbonyl) ethyl-0,0-dimethylphosphorothioate (malathion); 0,0,0 ', 0'-tetraethyl-S, S'-methylenedi (phosphorothioate) (etion); O- (4-bromo-2,5-dichlorophenyl) -O, O-diethylphosphorothioate (bromophos-ethyl); S-4-chlorophenylthiomethyl-O, O-diethylphosphorothioate (carbophenothion); 2-chloro-1- (2,4-dichlorophenyl) vinyldiethylphosphate (chlorfenvinphos); 0-2,5-dichloro-4- (methylthio) phenyl-0,0-diethylphosphorothioate (chlorothiophos); O-4-cyanophenyl-O, O-dimethylphosphorothioate (cyanophos); O, O-dimethyl-O-2-methylthioethyl phosphorothioate (demephion);

O, O-diethyl O-2-ethylthioethyl phosphorothioate (demeton); 0-2,4-dichlorophenyl-O, O-diethylphosphorothioate (dichlorophention); 0-2,4-dichlorophenyl-O-ethylphenylphosphonothioate (EPBP); 0,0-diethyl-5-O-Fe-

Nylisoxazol-3-ylphosphorothioate (isoxathion); 1,3-di (methoxycarbonyl) -l-propen-2-yl dimethyl; S, S '- (1,4-dioxane-2,3-diyl) -0,0,0', 0'-tetraethyldi (phosphorothioate) (dioxathione);

O, O-dimethyl-O- (4-nitro-m-tolyl) phosphorothioate (phenitrothione);

O, O-dimethyl-O-4-methylthio-m-tolylphosphorothioate (fention);

O- (5-chloro-1-isopropyl-1,2,4-triazol-3-yl) -0, O-diethylphosphorothioate (isazofos); S-2-isopropylthioethyl-O, O-dimethylphosphorothioate (isothioate); 4- (methylthio) phenyl dipropyl phosphate (propafos); 1,2-dibromo-2,2-dichloroethyldimethyl phosphate (naled); O, O-diethyl-2-cyanobenzylideneaminooxyphosphonothioate (foxime);

O, O-diethyl O-4-nitrophenylphosphorothioate (parathion); O-2-diethylamino-6-methylpyrimidin-4-yl-O, O-diethylphosphorothioate (pirimiphosethyl); O-2-diethylamino-6-methylpyrimidin-4-yl-O, O-dimethylphosphorothioate (pirimiphos-methyl); (E) -O-2-isopropoxycarbonyl-1-methylvinyl-O-methylethylphosphoramidothioate (propetamphos);

0,0,0 ', 0'-tetraethyldithiopyrophosphate (sulfotep); 0,0,0 ', 0'-tetramethyl-0,0'-dithio-p-phenylenediphosphorothioate (emephos); S-2-ethylthioethyl-O, O-dimethylphosphorothioate (thiometone); O, O'-diethyl-O- (1-phenyl-1H-1,2,4-triazol-3-yl) phosphorothioate (triazophos); O-ethyl-O- (2,4,5-trichlorophenyl) ethyl phosphonothioate (trichloronate); O-ethyl-S-phenylethylphosphonothioate (phonophos); 3- (phenoxybenzyl - (+) - cis, trans-3- (2,2-dichlorvinyl-2,2-dimethylcyclopropanecarboxylate (permetrin); (±) -? - cyano-3-phenoxybenzyl - (+) cis, trans- 3- (2,2-Dichloro-vinyl) -2,2-dimethyl-cyclopropanecarboxylate (cypermethrin); (2,3,5,6-Tetrafluoro-4-methyl-phenyl) -methyl- (1a, 3a) - (Z) - (±) - 3- (2-chloro-3,3,3-trifluoro-1-propenyl) -2,2-dimethylcyclopropanecarboxylate (teflutrin); [1a (S *), 3a (Z)] - (±) cyano- (3- phenoxybenzyl) -3- (2-chloro-3,3,3-trifluoro-1-propenyl) -2,2-dimethylcyclopropanecarboxylate (lambda-cyhalothrin);

(S) -? - cyano-3-phenoxybenzyl-3- (2-chloro-3,3,3-trifluoro-1-propenyl) -2,2-dimethylcyclopropanecarboxylate (cyhalothrin);

(S) -α-Cyano-3-phenoxybenzyl- (1R, 3R) -3- (2,2-dibromo vinyl) -2.29 ············

-dimethylcyclopropanecarboxylate (deltamethrin);

and (1R, 3S) 3 [1 'RS] 1', 2 ', 2', 2'-Tetra-bromomethyl)] - 2,2-dimethyl-cyclopropanecarboxylate (S) - α-cyano-3-phenoxybenzyl ester (tralometrine); (±) -3-Allyl-2-methyl-4-oxocyclo-2-pentenyl- (±) - cis, transchrysantemate (alletrin); (±) -3-Allyl-2-methyl-4-oxocyclo-2-pentenyl- (±) -trans-chrysantemate (bioalletrin); 3-phenoxybenzyl (±) -cis, trans-chrysantemate (phenotrine); pyrethrines, 2- (2-butoxyethoxy) ethylthiocyanate; isobornythiocyanoacetate (terpinylthiocyanoacetate); 2- (4-tert-butoxyphenoxy) cyclohexyl-2-propynyl sulfite (propargite); 4,6-dinitro-6-octylphenyl crotonates (dinocap); and ethyl-4,4'-dichlorobenzilate (chlorobenzilate).

Defoliants include S, S, S-tributyl phosphorfortritioate and tributyl phosphorfortritioite (merphos).

Fungicides include copper naphthenates; 5-ethoxy-3-trichloromethyl-1,2,4-thiadiazole (etridiazole); O-ethyl-S, S-diphenylphosphorothioate (edifenphos); N-trichloromethyl-4-cyclohexene-1,2-dicarboximide (captan); and methyl (E) -2- {2- [6- (2-cyanophenoxy) pyrimidine-4-cyloxy] phenyl} -3-methoxyaerylate (azoxystrobin).

Insect repellents include 6-butoxycarbonyl-2,3-dihydro-2,2-dimethylpyran-4-one (butopyronoxyl); N, N-diethyl-m-toluamide (deet); dibutyl phthalate; dibutyl;

1,5a, 6,9,9a, 9b-hexahydro-4a (4H) -dibenzofuránkarboxaldehyd; and dipropylpyridine-2,5-dicarboxylate.

The polymeric coating of the microscopically encapsulated particles may consist of any material commonly used as a packaging material in the pesticide manufacturing area or other industrial area that does not melt at the temperatures used for drying. Overview of such materials ··

Er · · · poskytuje poskytuje Sch Sch Sch Sch Sch Sch Sch Sch Sch Sch Sch Sch Sch Sch Sch Sch Sch Sch Sch Sch Sch in "Controlled Release Pesticides, ACS Symposium, Series 53 (1977), p. 126-144. Similar polymers can be used in the production of microparticles.

Examples of microscopic capsules that may be used are polyurea materials made by the method described in US Patent 4,285,720. These polyurea walls are made by heating or adding a suitable catalyst to a water-immiscible material dispersed in the aqueous phase. The water-immiscible material comprises one or more aromatic polyisocyanates, for example, 1-chloro-2,4-phenylenediisocyanate, m-phenylenediisocyanate, p-phenylenediisocyanate, 4,4'-methylene-bis (phenyl isocyanate), 2,4-tolylenediisocyanate (tolylene diisocyanate) 60% 2,4-isomer, 40% 2,6-isomer), 2,6-tolylenediisocyanate, 3,3'-dimethyl-4,4'-biphenylenediisocyanate, 4,4'-methylenebis (2-methylphenylisocyanate), 3 , 3'-dimethoxy-4,4'-biphenylenediisocyanate, 2,2 ', 5,5'-tetramethyl-4,4'-biphenylenediisocyanate, 80% 2,4-isomer and 20% 2,6-isomer of tolylene diisocyanate or polymethylene polyphenyl isocyanate (PAPI).

Another class of materials that can be used are aminoplast microscopic capsules manufactured by the method described in US Patent 4,956,129. These microcapsules are prepared by (a) preparing an organic solution comprising a substantially water-insoluble liquid material and an etherified urea-formaldehyde prepolymer dissolved therein in which about 50% to 98% of the methylol groups are etherified with a C 4 -C 10 alcohol; (b) forming an emulsion of the organic solution in a continuous phase comprising an aqueous solution comprising water and a surfactant, the emulsion comprising discrete droplets of an organic solution dispersed in the continuous phase of an aqueous solution;

·········, thus forming an interface between discrete droplets of organic solution and the surrounding continuous phase formed by the aqueous solution; and (c) simultaneously heating the emulsion to a temperature of about 20 ° C to 100 ° C and adding an acidifying agent and maintaining the emulsion at a pH of about 0 to 4 for sufficient time to fully condense the resin prepolymers in situ and cure the urea-formaldehyde prepolymer. an organic phase of discrete droplets adjacent to an interface in which the organic solution droplets are converted into capsules formed by solid permeable polymeric envelopes encapsulating the liquid material.

A third illustrative class of polymeric walls that can be used with the microcapsules in the flake of the invention are polymeric walls made by the method described in US 3,577,515. In this method, the encapsulation of the material is first accomplished in the liquid by polycondensation of the coating intermediates at the interface of the respective immiscible liquids and a few droplets of one liquid are introduced into the body of the second liquid, then a second intermediate is incorporated into the second liquid to form microcapsules of the first liquid having the coating. formed by a polycondensate, for example polyamide, polysulfonamide, polyester, polycarbonate, polyurethane or polyurea.

A fourth type of polymeric wall is a polyurea wall made by condensation of an aromatic isocyanate with an amine, as described, for example, in US Patent 5,354,742. Still other types of polymeric walls are described in US Patent 5,354,742.

The spacer material present in the flakes of the invention may include any water-soluble or insoluble substance. If a solid is used as a spacer

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insoluble in water, then it will generally have a particle size of about 0.01 µm to 100 µm, preferably about 0.05 µm to 15 µm. The spacer material performs several functions. Firstly, it serves as a drying matrix that holds the capsules together in the form of a flake and simultaneously separates them from each other; secondly, it promotes water dispersibility and acts essentially as a granulating agent. It also serves as a lubricant in the manufacture of flakes during drying, see below, which facilitates their removal from the heated surface.

Some substances, especially surfactants, may perform these functions in addition to the surfactant functions described below. If so, the single material may act as a spacer and at the same time as a surfactant. However, in the case of surfactants which are unable to perform all the necessary functions of the spacer material, a separate spacer material is added. Alternatively, a cheaper spacer material can be used instead of a portion of the expensive surfactant, thereby saving.

When used with pesticides, the spacer material may comprise a pesticidally active or pesticidally inactive material. Examples of inactive materials that can be used are bleaching clay, kaolins, bentonite, diatomaceous earth, dolomite, calcium carbonate, talc, powdered magnesium oxide, gypsum, and inorganic salts such as sodium chloride. These or other inactive materials may suitably be used as spacer materials for other types of encapsulated components.

A wide variety of pesticides, in particular herbicides or growth regulators, can be used as a spacer component of the compositions of the invention. These herbicides and growth regulators are derived from various classes of compounds. which include various water-soluble and water-insoluble derivatives of ureas, triazines, carbamates and their thio-, dithio- and thiol-variations, acetamides, acetanilides, diphenyl ethers and dinitrophenyl ethers, imidazolidines, N-phosphonomethylglycines, glyphosates, glyphosates etc. Particularly interesting and preferred non-encapsulated herbicidal or plant growth regulating ingredients in the form of the water-dispersible granules according to the invention are the water-soluble salts of glyphosate, in particular alkaline earth metal salts, ammonium salts or ammonium salts and water-insoluble 2-chloro-4-ethylamino compounds -6-isopropylamino-1,3,5-triazine (atrazine), 2- (4,5-dihydro-4-methyl-4- (1-methylethyl) -5-oxo-1H-imidazol-2-yl) -3-quinolinecarboxylic (imazaquin) and benzoylcyclohexanediones, for example 2- (2'-nitro-4'-methylsulfonylbenzoyl) -1,3-cyclohexanedione and their metal chelates.

Other suitable herbicides useful as the unencapsulated ingredients of the water dispersible granules of the invention include the following products (listed under the general designation): ametryne, aminotriazole, ammonium sulphamate, barban, bentazone _of benzthiazuron, bifenox, bromacil, boromofenoxim, bromophosoxyethyl, bromoxynil, bromoxynil, , brompyrazone, butylate, chloramben, chloroxuron, chlorthal-dimethyl, chlorthiamide, chlortoluron, cyanazine, cycluron, dalapone, desmedipham, 2,4-D, desmetryne, dicamba, dichlorbenil, dichlorprop, dinitramine, dinoterb, diquat, diuron, EPMA, EPMA, EP , fenoprop, fenuron, flumeturon, isoproturon, linuron, maleic hydrazide, MCPA, MCPB, metamitron, methabenzthiazuron, methazole, metoxuron, metribuzin, monolinuron, monnuron, naptalam, neburon, paraquat, picloram, propanil, propanil, propachil, propachil, propachil simazine, simetryne and 2,4,5-T.

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According to one aspect of the invention, some of the aforementioned water-insoluble herbicides used as encapsulated components may be used in alternative embodiments as the encapsulated component of the water-dispersible granules and vice versa. The capsules may contain two pesticidal ingredients, using a third pesticide as a spacer. For example, the encapsulated material may comprise a solid pesticide suspended in a second liquid pesticide, while the third pesticide may be used as a spacer. If the total product contains more than one pesticide, then the pesticides present may have similar activity (for example, all may be herbicides) or different activity (for example, the product may contain different combinations of herbicide and fungicide, herbicide and insecticide, fungicide and insecticide and insect growth regulator etc.). ).

Some solid herbicides such as N- (3,4-dichlorophenyl) -N'-methoxy-N'-methylurea (linuron) or 4-amino-6-tert-butyl-3- (methylthio-as-triazine-5- ( 4H) -one (metribuzin), when used as encapsulated components, cannot be encapsulated directly but can be dissolved or suspended in water or solvent insoluble copesticide (s) and subsequently encapsulated.

Representative insecticidal pesticides that are not encapsulated but can be introduced together with an encapsulated water-soluble herbicide include, for example, the following products: abamectin, aldicarb, acephate, aldrin, aminocarb, azinphos, bendiocarb ,.

carbaryl, chlormephos, DDT, dicofol, diflubenzuron, endothion, fenvalerate, heptachlor, methiocarb, methomyl, methyl- and ethyl-parathion, permethrin, cypermethrin, pyrethrin, terbufos, etc.

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Representative fungicidal pesticides which are not encapsulated but which can be used in conjunction with the above encapsulated herbicides and / or insecticides include the following products: anilazine, benodanil, benomyl, butacarb, captafol, captan, carboxin, chloranil, chlorbromuron, chloroneb, chlorthalonil, chlorquinox, dazomet, dichlofluanid, diclone, dichloraphen, dichloran, dithianon, dodine, ferbam, ŕolpet, mancozeb, maneb, thiabendazole, thiram, zineb, ziram, etc. \ ^N ° microencapsulated component of the water-dispersible granules may be, together with low-melting insecticides and herbicides or plant growth regulators to use other fungicides having a low melting point. Examples of such fungicides are dinocat, edifenphos and pyrazophos.

Representative nematicides that may serve as an encapsulated component herein include, for example, terbufos, fensulfothion, carbofuran, ethoprop, fenamiphos, dichloropropene, aldicarb, and oxamyl.

Representative acaricides that may serve as an encapsulated component include, for example, formetanate hydrochloride, omite, profenophos dimethoate, ethion, dinocapticofol, amitraz, oxythioquinox, cyhexatin, fenbutatin oxide, oxamyl and phosalone.

Representative antidotes useful with herbicides that are particularly suitable for the water-dispersible granules of the invention include, for example, 5-thiazolecarboxylic acid, 2-chloro-4- (trifluoromethyl), (phenylmethyl) ester, (flurazole);

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N-dichloroacetyl-1-oxa-4-azaspiro [4.5] decane (AD-67); N-dichloroacetyl-N, N-dialylacetamide (R-25788); N-dichloroacetyl-2,2-dimethyl-3-oxazolidine; N-dichloroacetyl-2,2,5-trimethyl-1,3-oxazolidine (R-29148); 2 - [(cyanomethoxy) imino] benzeneacetonitrile; 2 - [(1,3-dioxypyran-2-ylmethoxy) imino] benzeneacetonitrile; ethanone; 2,2-dichloro-1- (1,2,3,4-tetrahydro-1-methyl-2-isoquinolyl) - and the like.

Representative plant growth regulators which are particularly used herein as an unencapsulated component in water dispersible granules are, for example, chlormequat chloride, calcium arsenate, diaminozide, ephofumesate, ancymidol, dicegulac sodium, ethephon, XE 1019, maleic hydrazide, flurprimidol, mefluididol, mefluididol, mefluide fluridamidel, amidichlor, sulfometuron methyl.

The water-dispersible granules according to the invention may comprise mixtures of the encapsulated pesticide or pesticide-containing microparticles and the unencapsulated antidote or mixture of antidotes.

The flakes of the invention may be prepared by (a) mixing the aqueous dispersion of microcapsules or microparticles with the spacer material (s) and / or one or more water-soluble solid surfactants to form a dispersion; (b) drying the dispersion in a thin layer.

The surfactants used in the present invention may be nonionic, anionic, cationic or amphoteric and must be selected from those which are in liquid or molten state at the temperatures used to dry or remove the dried product. Surface selection

· · ···· ·· ···· · · • • · • • · · • · • · • • • · · • · • • • • · · · • · · • • • · • · · • · • ···· · · ·· · · · · · ·

care should be taken to avoid the use of surfactants which are so hydrophobic as to allow the encapsulation of the material to be extracted.

Suitable cationic surfactants include, for example, quaternary ammonium compounds such as cetyltrimethylammonium bromide. Suitable anionic surfactants are, for example, soaps, salts or monoesters of sulfuric acid, for example sodium lauryl sulphate, salts of solfonated aromatic compounds, for example sodium dodecylbenzene sulphonate, sodium, calcium or ammonium lignosulphonate or butyl di-phthalene sulphonate and triphthalenesulphonate sulphate, and triphenyl sulphonate sulphonate. Suitable nonionic surfactants are, for example, ethylene oxide condensation products with fatty alcohols, such as oleyl alcohol or cetyl alcohol, or alkylphenols, for example octylphenol, nonylphenol and octylcresol. Other nonionic surfactants include block copolymers of ethylene oxide and propylene oxide, partial esters derived from long chain fatty acids and hexitol anhydrides, and condensation products of these partial esters with ethylene oxide.

The aqueous dispersion to be dried generally contains about 25 wt. % to 75 wt. solids (microcapsules and spacer and / or surfactant), wherein the weight ratio of spacer and / or surfactant to microcapsules is from about 1:20 to 20: 1 and preferably from about 1:15 to 1: 3. The composition will generally contain about 1 wt. % to 90 wt.%, preferably about 3 wt. % to 15 wt. surfactant with respect to dry matter content.

• é ·· ···· · · • • · • • in · • · · · • • • · · • • • • • · • · · e • · • • • · • · · • • • ···· · · ·· · · · · · ·

Thin-layer drying used to produce the product of the invention can be carried out by any technique known in the art. In this drying, the material to be dried is fed to the heated surface in the form of a relatively thin film and the liquid (e.g. water) is removed by the generated heat and / or a stream of air or inert gas.

The preferred thin-layer drying method used in the present invention is drum or roller drying, in particular drying, wherein the suspension of capsules or microcapsules is fed between two drums which rotate against each other. The emulsion forms a film on the surface of the drums which passes through the space between the drums and which is dried on the surface of the drum. Other forms of drum or roller drying can also be used, for example single cylinder drying, in which the slurry is applied to the heated roller by immersing the roller in the slurry or can be applied to the rollers from above. Other techniques may also be used, such as spilling the suspension on a horizontal heated surface or heated moving belt or evaporating the spread film.

The flakes produced are removed from the heated surface by scraping, shaking, etc. at the temperature at which the surfactant used is still in liquid or molten form. The removal may be carried out continuously (for example, using a continuously scraped drum dryer) or batchwise (for example, scraping or shaking the horizontal heated surface). Drying can also be carried out continuously or batchwise.

The film or sheet may be of any size to produce the desired flakes in use.

· · ···· ·· ···· · · • · • • · · • · • • • · · • · • • · • · · • · · • • · • · · • · ···· · · ·· · · ·

of the selected device. Preferably, the film will have a maximum thickness three times greater than the maximum desired thickness of the flakes produced, or a thickness of about 0.075 mm to 6 mm.

The drying temperature will depend on the nature of the encapsulated material or microparticle material and the spacer / surfactant material and should be such as to allow economical and efficient drying while not causing decomposition or degradation of the encapsulated material. Generally, temperatures from about 20 ° C to 200 ° C, preferably from 50 ° C to 150 ° C, and most preferably from about 70 ° C to 100 ° C can be used. The above temperatures refer to the product temperature and not the ambient temperature. If the encapsulated material is heat sensitive, then the process is carried out under reduced pressure. The pressure may generally be atmospheric pressure or lower pressure.

One advantage of this method is that it can produce dry dispersed microcapsules or microparticles from more concentrated or more viscous suspensions, such as those that can be used in spray-drying methods, if the viscosity of the suspension is not high enough to interfere with thin film formation. , on the heated surface of the dryer.

The flakes of the invention will generally be less likely to agglomerate when subjected to compressive forces and will be less dusty than spherical formulations and more readily dispersible than extruded formulations.

The following examples are illustrative only and are not to be construed as limiting the scope of the invention as set forth in the appended claims.

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DETAILED DESCRIPTION OF THE INVENTION

Example 1

In a one liter, blade disperser to prepare a formulation, the composition of which is summarized below under the designation IA-1E, and the formulations were mixed at a medium 2000 ^min-1 to 3000 ^min-1, while the solutions were homogenized. Formulations IA to 1E contained polyurea microcapsules containing about 80 wt. alachlor from Monsanto Company, sold under the trade name Lasso Micro-Tech.

These formulations were processed in a laboratory two-drum dryer operating at atmospheric pressure. The laboratory unit was a model with a diameter of 15 cm and a length of 19.06 cm. The drums were arranged to rotate inwards and downwards and were driven by a motor which gave them a speed of 0.5 min ^-1 to 13 min ^-1 . The drums were rotated at a rate of 0.75 min ^-1 to 3.5 min ^-1 and formed a gap of 1.1 mm between them. The steam was supplied at a pressure of 0.1 MPa to 0.14 MPa and gave a surface temperature of 120 ° C to 126 ° C.

• f ···· ·· ····

STATEMENT A B C D E Microcapsules in water (60% by weight) 500 500 500 500 500 Daxad 23 (dispersant) 20 15 10 5 - Talc (lubricant) - 5 5 5 5 Pluronic F108 (non-ionic surfactant) - - 5 5 10 Total (grams) 520 520 520 520 520 Vapor pressure (MPa) 0,103 0,103 0,110 0,131 0,138 Drum speed (min ^-1 ) 0.75 0.75 0.75 1.0 1.0 Gap (mm) 1.75 1.75 1.75 1.75 2.54

The suspensions were introduced into the gap at a varying speed by means of a peristaltic pump. The flow of liquid introduced into the gap gradually increased until a uniform foil formed on the surface of the drums. The dried film was scraped off with knives and stored in receiving pans. The dried products obtained in this way were dust-free and their particles were in the form of thin flakes. The length of the flake ranged from 1 mm to 10 mm and the thickness from 0.05 mm to 2.0 mm.

The flakes produced at each run were used for tests to determine their dispersibility. These tests were performed as follows:

In a dispersion tube (250 ml) with a conical tapered bottom and cap, filled with 200 g of water, 2 g of the product (preweighed) were poured and the tube was quickly sealed. Immediately thereafter, the tube was rotated 180 °, left in this position for 5 seconds, and then returned to its original position. This overturn was repeated twenty times. The tube was allowed to stand for approximately 5 minutes and then sedimentation was determined.

·· ···· 99 999999

9

9 9 9 9 9

9 9 9 9 99

9999 99 99 99 99999

No sedimentation was observed in any sample. A sample was taken from the solution and used for observation under a microscope. Observations showed no damage to the capsules. For the sample, the redispersibility was determined by visual inspection of the material in a dispersion tube and inspection of the material under a microscope.

All the products obtained in Example 1 were shown to be capable of redispersing in water.

Example 2

An aqueous suspension of aminoplast microcapsules containing acetochlor herbicide (66.6 wt%) and the antidote dichloromethane (R-R-25788) (11.4 wt%) and adjuvant was prepared.

The capsule suspension contained 58.5 wt. % microcapsules and 41.50 wt. water and dissolved materials. In a one-liter flask were then prepared formulations 2A to 2E, and the formulation was stirred at 2000 min ^-1 to 3000 min ^-1, while were homogenized.

The obtained formulations were again processed in a laboratory two-drum dryer operating at atmospheric pressure, which was already used in Example 1.

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STATEMENT 2A 2B 2C 2D 2E Microcapsules (58.5 wt. 780 780 780 780 780 in the water) Morwet IP (dispersant) 20 20 20 20 40 Pluronic F108 (non-ionic surface- - 10 10 10 breeding active agent) Zeofree 80 (Silica) - 10 - - - talc - - - 10 - Total (grams) 800 820 810 820 785 Drum speed (min ^-1 ) 4.5 4.5 2.5 2.5 2.5 Surface temperature (° C) 132 132 132 132 132 Gap (mm) 1.78 2.03 2.03 2.03 2.03

The dried products were dust-free, the flake length being in the range of 1.0 mm to mm and the thickness in the range of 0.05 mm to

1.0 mm. All samples were redispersed in water.

Example 3

The following formulations (3A to 3E) were prepared from the same microcapsule suspension as those of Example 2 and mixed at medium speed (2000 min ^-1 to 3000 min ¹ until homogenized).

24 ·· ···· · · · · · • · · ····· ·· ···· · · · · · · • · · ·· · ·· • · • · • · · · • • · • • ·· · STATEMENT 3A 3B 3C 3D 3E Microcapsules (58.5 wt% in water) 725 560 560 560 650 Morwet IP (dispersant) 20 12.5 - Pluronic F108 (non-ionic surfactant) 29 Carbowax 8000 NF (humidifying agent) 20 20 20 Daxad 23 - - 12.5 - 12 Reax 85 (dispersant) - - - 12.5 - " Sodium chloride 20 15 15 15 - Calcium chloride 20 15 15 15 - talc - - - - 5 Water (viscosity reducing agent) 100 200 100 100 -

Total (grams)

Drum speed (min ^-1 ) 3.0 2.5 2.5 2.5 3.0 Surface temperature (° C) 125 125 125 125 120 Gap (mm) 2.03 2.03 2.03 2.03 2.03

The dried products were dust-free, the flake length being in the range of 1.0 mm to 5 mm and the thickness in the range of 0.05 mm to 1.0 mm. All samples were redispersed in water.

Example 4

The following formulations (4A to 4E) were prepared from the same microcapsule suspension as those of Example 2 and mixed at medium speed (2000 min ¹ to 3000 min ^-1 ) until homogenized.

The formulations were again processed in a laboratory two-drum dryer operating at atmospheric pressure as described in Example 1.

·· ···· ·· ···· ··

• • · · • · • · • · · • 25 • • · · · ··· • · ·· · • ·· · STATEMENT A B C D E Microcapsules (58.5 wt% in water) 685 555 555 555 555 Morwet IP (dispersant) 12.5 10 10 10 10 Igepal DM970 (non-ionic surfactant) 20 20 20 - Carbowax 8000 NF (humidifying agent) 20 - - - - Sodium chloride 15 20 - 12.5 10 Calcium chloride 15 '- 25 12.5 15 Total (grams) 147 605 610 610 600 Drum speed (min ^-1 ) 2.5 1.5 1.5 1.5 1.5 Surface temperature (° C) 125 125 125 125 125 Gap (mm) 2.03 1.52 1.52 1.52 1.52 The dried products were dust-free, length flakes was in ranging from 1.0 mm to 5 mm and thickness ranging from 0,05 mm to

1.0 mm. All samples were redispersed in water.

The flake was analyzed for acetochlor and R-25788 and the results are shown below.

INSERTS FROM ERÉKLAHJ 4A 4B 4C 4D 4E Wt. 57.8 57.6 58.9 58.3 61.3 R-25788 wt. 9.8 9.8 10.1 10,0 10.5

Biological assessments

The products obtained in Examples 4A to 4E compared the biological activity of these products with the biological activity of the acetochlorine product produced by spray drying similar microcapsules with four dispersion samples prepared from aqueous suspensions.

· · ···· ·· ···· · · • • • • · · • • • • • • · · • • • • · • · · • · • • • · • · · • · ···· · · ·· · · · •

Polyurea microcapsules containing acetochlor and not dried and with one liquid product (emulsifiable concentrate) which contained acetochlor without an antidote.

The products were diluted with water and preemergently applied to containers containing maize, soybean and weed seeds of the following weeds: Ipomenoea sp.-IPOSS, Panicum miliaceum Gentlemen, Sorghum bicolor - SORVU, Echinochloa crusgalli ECHCVI and Eriochloa villosa.

All products were appropriately diluted and applied at application rates (acetochlor) of 1.56 g / ha to 6400 g / ha. Control of weed and corn and soybean damage was evaluated twice, on the ninth day after acetochlor administration (Table I) and on the twentieth day after administration (Table II).

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· ·

TABLE 1-9 days after application Acetochlor g / ha sweet corn. SOYBEAN IPOSS lords S0R.VU ECHCG suspension 1.56 3 0 0 5 5 · capsules 6.25 25 2 5 5 0 3 5 20 0 23 30 93 Sample I 100 4 3 20 85 85 95 400 4 18 10 85 93 99 1600 4 6400 4 suspension 1.56 3 0 0 0 0 6.25 1 10 3 1 8 capsules 25 4 0 15 18 23 97 Sample II 100 5 3 5 90 93 97 400 1 35 43 85 95 99 1600 1 6400 4 suspension 1.56 0 18 0 0 0 capsules 6.25 25 2 3 3 18 5 0 8 0 25 5 90 Sample III 100 1 13 15 93 88 97 400 3 23 30 88 95 99 1600 2 6400 8 suspension 1.56 3 18 0 0 0 6.25 3 18 5 0 55 capsules 25 5 3 13 53 45 93 ' Sample IV 100 1 5 15 97 90 95 400 8 33 23 88 9 99 1600 1 6400 8 invention 1.56 3 18 0 0 0 Example 4A 6.25 3 18 0 0 0 25 4 3 13 5 5 90 100 3 3 15 80 68 97 400 0 5 23 97 90 98 1600 1 6400 1 invention 1.56 0 8 0 0 0 Example 4B 6.25 * 3 8 0 0 5 25 4 3 5 23 5 85 100 1 23 0 78 78 97 400 1 3 20 95 95 98 1600 3 6400 5 invention 1.56 3 10 5 0 0 Example 4C 6.25 3 8 0 0 0 25 4 0 18 0 0 93 100 1 3 15 38 75 97 400 2 10 23 95 93 98 1600 1 6400 13

(continued) ·· ···· ·· ···· ··

TABLE I (continued)

Acetochldr g / ha SWEET CORN SOYBEAN IPOSS lords Sorve ECHCG invention 1.56 5 18 0 0 3 Example 4D 6.25 3 0 13 0 0 0 25 0 0 8 10 0 88 100 0 5 15 63 73 97 400 4 13 13 95 90 97 1600 5 6400 invention 1.56 0 5 0 0 0 Example 4E 6.25 0 8 0 0 0 25 5 3 8 15 13 93 100 0 8 8 75 90 97 400 1 35 28 97 93 98 1600 1 6400 3 , the capsules 1.56 3 10 0 0 3 dried 6.25 0 13 0 0 0 spray 25 4 10 8 0 0 88 100 3 8 3 38 73 97 400 6 10 10 95 90 97 1600 1 6400 5 Bnulgovatefný 1.56 8 3 0 0 3 Concentrate. 6.25 5 13 0 0 10 without antidote 25 0 0 25 28 45 93 100 2 15 15 45 90 97 400 2 40 5 93 95 98 1600 10 6400 10

······················ · t

· · ·

TABLE II - 20 days after application

Acetochlor g / ha Sweet corn SOYBEAN IPOSS lords Sorve ECHCG ERBVI suspension 1.56 6.25 0 0 0 0 0 5 0 0 0 0 0 5 capsules 25 0 0 0 15 8 100 15 Sample I 100 0 0 0 97 94 100 65 400 0 13 0 93 100 100 99 1600 3 6400 0 suspension 1.56 6.25 0 0 0 0 0 0 0 0 0 0 0 0 capsules 25 0 0 0 10 20 99 5 Sample II 100 0 0 0 94 100 100 93 400 3 43 0 '88 100 100 83 1600 0 6400 1 suspension 1.56 0 0 0 0 0 0 capsules 6.25 0 0 0 0 0 0 25 0 0 0 10 0 98 0 Sample III 100 0 0 0 99 97 100 73 400 0 18 0 90 100 100 97 1600 4 6400 8 suspension 1.56 6.25 0 0 0 0 0 0 0 0 0 63 0 0 capsules 25 0 0 0 38 33 97 0 Sample IV 100 0 0 0 100 97 100 93 400 4 13 0 95 100 100 93 1600 2 6400 2 invention 1.56 0 0 0 0 0 0 Example 4A 6.25 0 0 0 0 0 0 25 0 0 0 0 0 93 0 100 0 0 0 83 48 100 60 400 1 15 0 100 48 100 93 1600 5 6400 4 invention 1.56 0 0 0 0 0 0 Example 4B 6.25 0 0 0 0 0 0 25 0 0 0 0 0 88 0 100 0 15 0 80 80 100 65 400 0 0 0 98 98 100 95 1600 0 6400 1 invention 1.56 0 0 0 0 0 0 Example 4C 6.25 0  0 0 0 5 0 25 0 0 0 0 0 95 0 100 0 0 0 43 75 99 95 400 0 18 0 100 100 100 97 1600 3 6400 4

(continued) t I ,, ·· ················

TABLE II (continued)

Acetochlor g / ha KUKUŔrcA SOYBEAN IPOSS lords Sorve ECHCG ERBVI invention 1.56 0 0 0 0 0 0 Example 40 6.25 0 0 0 0 0 0 25 0 0 0 0 0 75 0 100 0 5 0 60 78 100 88 400 0 5 0 100 100 100 95 1600 16 6400 0 invention 1.56 0 0 0 0 0 0 Example 4E 6.25 0 0 0 0 0 0 25 1 0 0 0 0 95 0 100 0 0 0 78 95 100 88 400 0 25 0 100 100 100 95 1600 0 6400 1 The capsules 1.56 0 '0 0 0 0 0 dried 6.25 0 0 0 0 0 0 spray 25 0 0 0 0 0 75 0 100 0 0 0 30 68 98 93 400 0 8 0 100 95 100 93 1600 2 6400 1 Eraulgovateiný 1.56 0 0 0 0 0 0 concentrate 6.25 5 0 0 0 10 0 without antidote 25 0 0 0 43 35 97 15 100 1 18 0 33 83 100 90 400 1 28 0 100 100 100 95 1600 4 6400 10

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Claims (16)

PATENT CLAIMS A water-dispersible flake comprising a plurality of microcapsules or microparticles comprising one or more encapsulated components, wherein said microcapsules or microparticles are held together in the form of a flake by a spacer and / or one or more surfactants . Flake according to claim 1, characterized in that the microcapsule shell is a polyurea material. The flake of claim 1, wherein the microcapsule shell is an aminoplast material. Flake according to claim 1, characterized in that the encapsulated components comprise one or more pesticides. Flake according to claim 4, characterized in that the encapsulated components comprise one or more herbicides. A Flake according to claim 5, characterized by. in that the encapsulated components comprise acetochlor. Flake according to claim 4, characterized in that the encapsulated components comprise one or more insecticides. ·· ···· ·· ···· Flake according to claim 7, characterized in that the encapsulated components comprise a pyrethroid. The flake of claim 8, wherein the pyrethroid is lambda-cyhalothrin. The flake of claim 1, wherein the spacer material comprises one or more non-encapsulated pesticides. The flake of claim 10, wherein the spacer material comprises atrazine. Flake according to claim 1, characterized in that the microcapsules or microparticles are held together by a spacer material and / or one or more surfactants. A process for producing a water-dispersible flake comprising a plurality of microcapsules or microparticles comprising one or more encapsulated components and held together by a spacer and / or one or more surfactants, characterized in that: a) admixing the aqueous suspension of said microcapsules or microparticles with a spacer and / or a surfactant to form a dispersion; b) drying the dispersion obtained by thin-layer drying on a heated surface; and c) removing the dried product of step (b) from the heated surface to form flakes. ·· ··········· • e ·· • • · • · • • · 33 • · · · • · · · · • • · • · • · • • • · · · · 9 • · • ···· ·· ·· • · · · · · The method of claim 13, wherein at least one of the steps is continuous. y of (b) (c) is carried out The process according to claim 13, wherein one or more active agents which are molten at the step temperature are used. in the case of solid surface (b) The method of claim 13, wherein step (b) is carried out at a temperature of about 20 ° C to 200 ° C.