MXPA98001160A - Composition for crop prosecution, quecomprende a solid particle for the protection of crops, covered with an insoluble material derevestimiento in water and a parala mix protection of crops that understands - Google Patents

Abstract

A composition comprising a solid mononuclear crop protection particle coated with a water insoluble coating material has a diameter in the range of 0.5 to 50æ. This composition is made by a process that results in substantial non-agglomeration of the coated particles. In a particle form, a crop protection composition comprises a solid, mononuclear crop protection particle coated with either wood rosin, rosin derivatives, waxes, fatty derivatives, sterols, long chain sterol esters and sulfur. Alternatively, the coating material may be a synthetic latex polymer, insoluble in water. The composition can be used in a mixture that also includes a chemical crop protection partner comprising a solid particle. The associate ordinarily degrades the particle for crop protection, solid when it is stored or aged together as a mixture of solid particles. However, when the solid particle of the composition is coated, this degradation is prevented.

Description

TITLE COMPOSITION FOR THE PROTECTION OF CROPS, WHICH UNDERSTAND A SOLID PARTICLE FOR PROTECTION OF CROPS, COVERED WITH AN INSOLUBLE COATING MATERIAL IN WATER AND A MIXTURE FOR THE PROTECTION OF CROPS THAT INCLUDES THE SAME BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a composition for the protection of. crops comprising a solid particle for crop protection, coated with a water-insoluble coating material. More specifically, this invention relates to a crop protection composition comprising a solid, mononuclear, individual particle, which can be either a solid particle for crop protection, chemistry, such as a herbicide, an acaricide, an insecticide, an npiticide, a plant growth regulator, a fungicide or a nematicide, or a solid particle for the protection of microbial cultures, such as beneficial viruses, nematodes, fungi, bacteria or protozoa, coated with a material REF: 26601 of insoluble coating in water. The chemical or particle for the protection of microbial cultures can be coated with either wood rosin, rosin derivatives, waxes, fat derivatives, sterols, long-chain sterol esters or sulfur. Alternatively, the chemical or particle for the protection of microbial cultures can be coated with a water insoluble latex polymer. Furthermore, the present invention relates to a mixture of such compositions for the protection of crops with an associate which is also a solid particle.

Description of Related Art The encapsulation of an active component, such as an insecticide is described in International Publication Number WO 95/08322. In this publication, "microcapsules" are prepared by dispersing or dissolving an active component or components in a solid matrix-forming material that has been thermally softened to form an encapsulation composition. The encapsulation composition is injected as an intact stream in a quench liquid to provide solid microcapsules. What is termed as "microcapsules" prepared by this method is actually a plurality of particles randomly dispersed through a solidified droplet or droplet of coating material. These microcapsules do not have a single mononuclear solid particle, such as a core surrounded by a wall of coating material. In addition, the diameter of such microcapsules has not been discovered. Large solid particles for crop protection, coated with water-insoluble materials (ie particles having a diameter of approximately greater than 50 microns) clog or obstruct the sieves and nozzles and thus can not be sprayed on the crops in the field. Known methods of coating or encapsulating small particles (approximately less than 50 microns) have serious process limitations. For example, spray drying results in aggregates of minute particles, or agglomerates, and requires the handling of solvents. In addition, such agglomeration reduces the biological effectiveness of the coated particles, since not all particles are available for activity. The fluidized bed coating is unsuitable for small particles, such as powders, because the tiny particles are difficult to fluidize in a fluid bed because the forces between the particles are greater than those that result from the action of the gas in the fluid bed. The particles are classified as Groups A, B, C and D of Geldart. The powders of Geldart Group C, that is, those less than 20 micrometers in diameter, are very difficult to fluidize. See Fluidization Engineering, Second Edition, Daizo Kunil and Octave Levespiel, Butterworth-Heinmann Series in Chemical Engineering, ISBN 0-409-90233-0, pp 77-79. The Wuster process is not suitable for coating small particles. Rotating disc processes are limited to particles greater than 50 micrometers, and require recovery / recycling steps of coating. Such processes are also unsuitable for non-spherical particle shapes and require a range of particle size, narrow for uniform coating. With the concentric nozzles, the active ingredients are driven through a coating composition. However, a technique of this kind is unsuitable for the coating of the individual particles, and they are aggregated. In addition, coating recovery systems are required with concentric nozzles. Finally, chemical coacervation is a batch-type process that produces aggregates of fine particles, is a diluted process, and requires the recovery of extensive solvent. Coated particles made from the techniques described above are also known. For example, European patent application, published No. 0 548 901 A1 discloses a microcapsule comprising agricultural active ingredients that are made by spray drying, which produces agglomerates as noted above. In addition, this publication describes the use of water soluble coatings, which may be hygroscopic and which are not useful for controlled release. European patent application No. 0 379 379 A2 describes coated agrochemicals and other particulate compositions, where the coating is formed by the coacervation of at least two water-soluble coacervation polymers. As noted above, coacervation requires the recovery of extensive solvent. In addition, publication 379 is directed to liquid coating active ingredients, liquid, coated active ingredients which have less tendency to settle in water than solids. The published international application WO 94/22302 discloses biologically active, coated particles and a process for manufacturing such particles by forming an aqueous suspension, emulsion or solution of a polymer or a polymer formation precursor which is used for the coating of the active particle, suspended. This coating process is not capable of completely coating a particle in one step, as evidenced by the fact that a second coating layer is necessary in order to coat the areas that are not coated by the first coating layer. The published international application WO 89/03638 describes a pesticidal compound which is composed of a substrate and a sulfonated polymer coating film. The substrate is relatively large in size, i.e., 1-10 mm. (1,000 to 10,000 micrometers). At least one surface of the substrate is coated with a sulfonated polymer film, dissolved in a solvent system. All the publications discussed in the previous paragraph require that the material to be coated first be suspended in a liquid to achieve the coating, which in this way creates problems of recovery of solids, difficult and which generates large streams of waste from the process. In addition, if such processes require water as the liquid, they can not encapsulate water-soluble particles. Thus, there is a need for solid particles for the protection of coated crops having a very small diameter, approximately less than 50 microns, and not agglomerating so that they can be sprayed without clogging a nozzle or screen. In addition, there is a need to develop a process for coating or encapsulating particles with very small diameters, approximately less than 50 micrometers, which results in a high yield of even non-agglomerated, coated, small particles. further, there is a need for a process that does not have problems of recovering solid helpers or assistants or large waste streams from the process. In addition, there is a need to develop a process that can encapsulate solid particles soluble in water, and by the resulting solid coated particles.

BRIEF DESCRIPTION OF THE INVENTION The present invention solves the problems of the prior art by providing a non-agglomerated crop protection composition where the diameter of the composition is very small, ie, in the range of 0.5 to 50 micrometers. The solid, coated particles of the present invention have increased biological efficiency as compared to agglomerated particles, since all non-agglomerated particles are available for activity. In addition, the solid, coated particles of the present invention are made by a process that results in a higher percentage of coated, small particles than do the processes of the prior art. This non-agglomeration is a result of the process by which the composition is made, which allows a solid particle to be coated directly with a coating material that is in the form of a molten material, without having to be suspended in a liquid. In this way, this process allows the encapsulation of solid particles, soluble in water. However, the coating material of the present invention needs not to be limited to a molten material, but may also be in the form of a solution or a slurry, which may be aqueous, where the coating material is either dissolved or without dissolving in a liquid, such as water, respectively. The solid, coated, non-agglomerated, small-diameter particles of the crop protection composition of the present invention can be sprayed on a sprinkler, without obstructing the sprinkler nozzle. In addition, with the present invention, unstable compounds, as well as stable ones, are capable of being isolated in a solid formulation. The crop protection composition of the present invention has a low acute toxicity during transfer, or even during spray application. Such a composition for the protection of crops regulates the mobility in soil of the active compounds in soils. With the crop protection composition of the present invention, the rates of application are reduced, and the selectivity between the crops and the weed is improved. In addition, the crop protection composition of the present invention provides the protection of microbes, both on the shelf and in the field environment. In addition, the present invention allows a crop protection composition to be mixed with an associate that ordinarily and chemically degrades the crop protection composition when stored or aged together as a mixture. Thus, with the crop protection composition of the present invention, the chemically unstable compounds are protected from hydrolysis, photolysis or other forms of degradation. Accordingly, the stable mixture of the present invention provides a broader spectrum of weed control, resistance or degradation, and possibilities for synergism. To achieve the above solutions and advantages, a crop protection composition is provided which comprises a solid mononuclear crop protection particle coated with a water insoluble coating material, wherein the coating material is selected from the group consisting of: wood rosin, rosin derivatives, waxes, fatty derivatives, sterols, long-chain sterol esters and sulfur, and the diameter of the composition for crop protection is in the range of 0.5 to 50 micrometers. Also in accordance with the present invention, there is provided a crop protection composition comprising a solid mononuclear crop protection particle coated with a water insoluble coating material, wherein the coating material is a polymer of synthetic latex selected from the group consisting of: a homopolymer of a first group of monomers and a co-polymer made from the first group of monomers combined with at least one monomer of a second group of monomers, and the diameter of the composition for protection of crops is in the range of 0.5 to 50 micrometers.

Also in accordance with the present invention, a crop protection composition is provided, comprising a mononuclear solid culture protection particle coated with a water insoluble coating material, wherein the coating material is a polymer of synthetic latex selected from the group consisting of: poly (ethylene terephthalate), polyamide resin, synthetic polyterpene, synthetic poly (beta-pinene) and cellulose esters, and the diameter of the composition for crop protection is in the range from 0.5 to 50 micrometers. Further, in accordance with the present invention, a crop protection mixture is provided, which includes a crop protection composition comprising a crop protection partner comprising a solid particle; and a composition for crop protection as described in any of the three preceding paragraphs.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic diagram of a portion of the apparatus according to the present invention. Figure 2 is a cross-sectional view, expended, in section of a portion of the apparatus shown in Figure 1.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES According to a first embodiment of the present invention, there is provided a crop protection composition comprising a solid mononuclear crop protection particle coated with a water insoluble coating material. In a version of the first embodiment, the water-insoluble coating material can comprise any of wood rosin, rosin derivatives, waxes, fatty derivatives, sterols, long-chain sterol esters or sulfur. In addition, the coating material may also be a mixture of any of these materials, except sulfur, and this may comprise other components. The diameter of the composition, that is, the final coated particle, is in the range of 0.5 to 50 micrometers (m), and preferably less than 30 micrometers. The coating is thin enough to make an insignificant difference in the diameter of the solid particle after it is coated, as compared before it is coated. For example, assuming the same density for the coating material and the solid particle, for a coating that is 5% by weight of the composition, the thickness of the coating material is 0.87% of the diameter of the solid, uncoated particle. For a coating that is 10% by weight of the composition, the thickness of the coating material is 1.7% of the diameter of the solid, uncoated particle. For a coating that is 50% by weight of the composition, the thickness of the coating material is 11.8% of the diameter of the solid particle, uncoated. With respect to the particular coating materials, the rosin derivatives can be any of the following: partially dimerized rosin, partially hydrogenated rosin, divalent metal salts, trivalent metal salts, maleic acid adducts / fumaric acid adducts, fumaric acid adducts / anhydride or pentaerythritol adducts, or mixtures of any of the foregoing. The salts of the divalent or trivalent metals are derived from any of the following: calcium, magnesium, iron, zinc, aluminum, manganese and barium, or mixtures of any of these. The waxes can be of natural origin, which means that these can be of animal, vegetable or mineral origin. Animal waxes include beeswax, lanolin, shellac wax and insect wax, china. The vegetable wax includes waxes of carnauba, of candelilla, of wax tree (Myruca pensyl vani ca), and of sugar cane. The mineral wax includes fossils or terrestrial waxes, which include ozokerite, ceresin and lignite montana, or petroleum waxes, which include paraffin and microcrystalline waxes. Alternatively, the waxes can be synthetic, or mixtures of natural or synthetic waxes. For example, particular coating materials may include a partially oxidized, low molecular weight polyethylene, which is preferably co-fused with paraffin, low molecular weight poly (ethylene / acrylic acid) or poly (ethylene / acid) low molecular weight methacrylic). It should be noted that the coating material can be any of the waxes described in this paragraph, or a mixture of any of these. The fatty derivatives can be either fatty acids, fatty metal salts of these fatty acids, fatty acid amides, fatty alcohols and fatty esters, or mixtures of any of the foregoing. In this context, "fatty" means long-chain aliphatic. In particular, the acid may be a carboxylic acid, such as stearic acid, and the salts may be calcium, magnesium, zinc or aluminum salts. The acid amine may be stearamide. The alcohol can be stearyl alcohol. The ester is formed from the reaction of a long chain acid with a long chain alcohol. The ester can be a fatty acid ester of a fatty alcohol or a fatty acid ester of glycerol. Sterols as such, or long chain sterol esters, mean an ester formed from a sterol, can also be used as the coating material. In any case, the sterols can be of animal origin (for example, cholesterol) or of plant origin (for example, ergosterol).

When wood rosin, rosin derivatives, waxes, fatty derivatives, sterols, long chain sterol esters or sulfur are used as the coating material, the coating material has a melting point within the range of 55 - 220 ° C. When one is within 20 ° C of the melting point, the molten coating material does not decompose and is film-forming, but not filament-forming. A laboratory test for film formation and filament formation can be described as follows: The first part of the test consists of melting the test coating material on a plate to measure the weight of aluminum, small so that in the cooling a thin, continuous film (1 mm or less in thickness) is formed, even when there is not enough material to spread on the bottom of the plate. The second part of the test involves dipping the end of a small spatula into a one-centimeter-deep mass of molten coating material and lifting the end of the spatula to approximately 2 cm. above the molten surface. The coating material is not filament former if the strands or filaments are formed between the molten material and the end of the spatula. This third part of the test is to keep the coating material at a temperature where the material is film-forming, but not filament-forming, to show that at least under a blanket of nitrogen, no significant degradation occurs, which is indicated by gas smelly, thick, etc., at this temperature for 10 minutes or more. Finally, the temperature at which the molten coating material is maintained must not be greater than 20 ° C from the melting point of the coating material. The coating material of the present invention is insoluble in water. Insoluble in water means those coating materials having a solubility in water of < 5% at 25 ° C. Thus, although it is preferred to coat solid particles using a coating material as a molten material, those coating materials that contain pendant carboxylic acid groups (eg, rosin, oxidized polyethylene, fatty acids) can be applied from a solution aqueous containing ammonia. As ammonia evaporates rapidly during the coating process, the original water-insoluble coating material is deposited on the solid particles. Alternatively, the coating material of the crop protection composition of the first embodiment may be a latex polymer, synthetic, water insoluble, or carboxylated versions thereof. A latex is an aqueous, colloidal suspension of a polymer resulting from the emulsion polymerization of one or more hydrophobic monomers in the presence of a sufactant and an initiator, which form small islands of plasticized polymer. These small islands join and form a continuous film coating on the surface of the solid particle during the process, while the water evaporates rapidly. In a version of this alternative of the first embodiment, the synthetic water-insoluble latex polymer can be either a homopolymer of a first group of monomers, or a copolymer made from the first group of monomers combined with at least one monomer of a second group of monomers. The second group of monomers includes monomers that are used to make copolymers by using at least one member of the first group of monomers. The first group of monomers is hydrophobic and the second group of monomers is hydrophilic. The first group of monomers includes ethylene; propylene; styrene; alpha-methylstyrene; vinyl chloride; alkyl acrylate, alkyl methacrylate; vinyl acetate; tetrafluoroethylene, acrylonitrile; alkylene, which includes butylene, isobutylene, isoprene and butadiene; chloroprene, divinylbenzene and vinyl alkyl esters (>; CIO). The second group of monomers includes an acrylic acid, methacrylic acid, vinyl alcohol, vinyl pyrrolidone and acrylamide. Examples of co-polymers of the first and second group of monomers include poly (ethylene / acrylic acid), poly (ethylene / methacrylic acid), poly (stearyl methacrylate / acrylic acid), poly (stearyl methacrylate / methacrylic acid), poly (styrene / maleic anhydride), poly (ethylene / vinyl alcohol), poly (alpha-alkene) (> CIO) / vinyl pyrrolidone), poly (ethylene / maleic anhydride), poly (ethylene / vinyl acetate), poly ( styrene / acrylonitrile) and poly (styrene / acrylonitrile / butadiene).

In another version of the alternative of the first embodiment, the synthetic water-insoluble latex polymer can be either poly (ethylene terephthalate), polyamide resin, synthetic polyterpene, synthetic poly (beta-pinene), cellulose esters, which include cellulose acetate and cellulose acetate / butyrate. The solid mononuclear crop protection particle of the present invention can be a solid, crystalline, individual particle. In addition, it can be a chemical for the protection of crops. Examples of such crop protection chemicals include herbicides, insecticides, acaricides, miticides, fungicides, nematicides, and plant growth regulators. Alternatively, the solid culture protection particle of the present invention may be a microbe for crop protection. Such microbes include beneficial viruses, bacteria, nematodes, fungi and protozoa. In addition, instead of a solid particle, the solid particle may comprise a low melting point active ingredient and a solid, porous, inert carrier particle where the low melting active substance is absorbed in the carrier particle, inert, solid , porous. By "low melting point active substance" is meant a material that is not a solid at room temperature, or at least a material that softens easily. In particular, the particle for solid culture protection can be bromacil (5-bromo-3-sec-butyl-β-methyluracil) (International Union of Pure and Applied Chemistry (IUPAC).) Alternatively, the particle for the Crop protection, solid can be a herbicide, such as a sulfonylurea.Sulfonylurea can be, but is not limited to, the following: tribenuron-methyl, thiofensulfuron, metsulfuron-methyl, bensulforon-methyl, chlorimuron-ethyl, rimsulfuron and azimsulfuron In a preferred embodiment of the present invention, the sulfonylurea herbicide is tribenuron-methyl, and the coating material is a mixture of low molecular weight, partially oxidized polyethylene, which is sold by Eastman Chemical Co. of Kingsport, Tenn. as EPOLENE E10 (later referred to as "EPOLENE E10"), and paraffin In another preferred embodiment of the present invention, the sulfonylurea herbicide is tribenuron-methyl, and the coating material is rosin from With the present invention, the solid particles coated with the composition can be joined together by means of water-dispersible bridges in the form of water-dispersible granules. These granules are dispersed to individual, small coated particles in a mixing water tank, so that they can be sprayed without clogging the screen or nozzle. This makes sprayable possible, since it is necessary for the composition to disperse the coated, individual particles when mixed with water in a mixing tank before spraying. It also increases the biological effectiveness of the particles, since they do not agglomerate. The composition of the present invention can be made into a wettable powder by adding adjuvants such as surfactants, wetting agents, dispersants and diluents. The wettable powder can also be formed in a water dispersible granule. This can be done by any of the conventional methods in the art such as compaction, which is preferred, extrusion of molten material or paste, pan-granulation or a fluidized bed. Particle agglomeration occurs in dipserial granules in water, but particle-to-particle bonds are dispersible in water. The wettable powder can be packaged in conventional containers or preferentially as water soluble bags. This allows one to add a soluble bag to a powder-free mixing tank to find powder, which often accompanies the very small size manageable particles. As noted above, the coating materials of the present invention are insoluble in water. This prevents rapid uptake of water from the air. However, the coating materials are sufficiently water permeable as a thin coating to effectively release the solid particle for crop protection in the brief mixing in a mixing tank with water, and / or in contact with dew, once deposited in the target plant or soil. In this way, when the faster release of the solid particle, especially an active substance, is desired, then less hydrophobic and / or thinner or more permeable coatings may be used, for example, <; 20%, and usually < 10% This ensures the immediate availability of the solid particle for crop protection in mixing with water in a mixed tank. If a controlled release formulation is desired in the spray on the crop or soil, a thicker or more hydrophobic coating can be selected. In this case, the solid particle for crop protection would be slowly released when exposed to rain or dew. When an insecticide is used as the controlled release solid particle, it can be released upon ingestion and extraction in the digestive tract of the insect. In addition, according to a second embodiment of the present invention, a mixture for crop protection is provided. The mixture comprises an associate for the protection of crops. The partner is a solid particle, and it can be either a chemical substance or a microbial partner. The solid particle may comprise a low melting active substance and an inert, solid carrier particle where the low melting active substance is absorbed in the carrier particle, inert, solid. In addition, the mixture comprises a composition for crop protection, as described above with respect to the first embodiment. The associate ordinarily degrades the particle for crop protection, solid when it is stored or aged together with a mixture. The present invention prevents the particle for the protection of crops from degradation when it comes in contact with the associate. With the crop protection mixture of the second embodiment, it is possible to have a water-dispersible granule of a crop protection composition mixed or stored with the associated, in the form of a powder, a water-dispersible granule of the partner mixed or stored with the composition for the protection of crops, in the form of a powder, a water-dispersible granule of the crop protection composition mixed or stored with a water-dispersible granule of the associate, or a water-dispersible granule , individual containing particles of the composition for crop protection and the associated. The key requirement of the present invention is that each of these water-dispersible granules is dispersed in the individual coated particles or the partner particles when added to the water in a mixing tank. As with the composition for crop protection as described above, the solid particles, coated with either the crop protection composition or the crop protection mixture, which may be in the form of a powder, can be to make in a wettable powder by adding adjuvants such as surfactants, wetting agents, dispersants and diluents. The wettable powder can also be formed in a water dispersible granule. This can be done by any of the conventional methods in the art such as compaction, which is preferred, melt or paste extrusion, pan-granulation or a fluidized bed. As noted above with respect to the first embodiment, particle agglomeration occurs in water-dispersible granules, but particle-to-particle bonds are dispersible in water. As with the crop protection composition, the wettable powder form of the crop protection mixture of the present invention can be packaged in conventional containers or preferentially as water soluble bags. The crop protection composition or the partner particles, or both, are stored individually or mutually in the mixture as water dispersible granules. The partner can be a herbicide, such as a hormone, anticholinesterase, or glyphosate family. Examples of hormones include phenoxies, such as 2, 4-D derivatives (2,4-dichlorophexyacetic acid), especially the sodium or acid form, and MCPA [(4-chloro-2-methylphenoxy) acetic acid]. Examples of anticholinesters include organophosphorous herbicides, such as anilophos. The partner can be a solid particle or can comprise a low melting active substance and a solid, porous, inert carrier particle, where the active substance is absorbed in the carrier particle, inert, solid, porous. As discussed above, the particle for crop protection, solid of the composition can be a chemical for the protection of crops. Examples of such chemicals for crop protection include herbicides, insecticides, acaricides, miticides, fungicides, necticides and plant growth regulators. Alternatively, the solid culture protection particle of the present invention may be a microbe for crop protection. Such microbes include viruses, bacteria, nematodes, fungi and beneficial protozoa. In particular, the solid particle for crop protection of the composition can be a herbicide, such as a sulfonylurea. The sulfonylurea may be, but is not limited to, the following: tribenuron-methyl, thifensulfuron, metsulfuron-methyl, bensulfuron-methyl, chlorimuron-ethyl, rimsulfuron and azimsulfuron. It is preferable that the weight ratio of the sulfonylurea to the weight of the associate be in the range of about 1/10 to 1/200. In a preferred embodiment, the partner is 2,4-D (2,4-dichlorophenoxyacetic acid) and the composition comprises tribenuron-methyl coated with a mixture of low molecular weight, partially oxidized polyethylene (EPOLENE E10) and paraffin. In another preferred embodiment, the partner is 2,4-D (2,4-dichlorophenoxyacetic acid), and the composition comprises tribunuron-methyl coated with wood rosin. Reference will now be made in detail to a suitable apparatus and process for making the composition for crop protection, described above. An example of such an apparatus is illustrated in Figures 1 and 2. Coating is understood to adhere a layer of a substance to the surface of a solid particle, and includes the encapsulation of substantially all, or all, of the surface of the particle. solid It should be noted that while one passes or circulates from the process of the present invention, it completely coats or encapsulates the solid particle, more than one step can be used to adhere the additional coating material to the solid particles, depending on the desired thickness of the coating. . The apparatus and process of the present invention can be used to make a crop protection composition comprising a solid particle for crop protection, solid coated with a coating material. In particular, the apparatus and process can be used to make a coated particle having a diameter in the range of about 0.5 to 50 m, and preferably less than about 30 m. The solid, coated crop protection particle made by the process of the present invention encompasses any solid particle for the protection of crops and any coating material. The solid particle can be either a solid particle for crop protection, chemical, such as a herbicide, an acaricide, an insecticide, a miticide, a plant growth regulator, a fungicide or a nematicide, or a solid particle for crop protection, microbial, such as beneficial viruses, nematodes, fungi, bacteria or protozoa. The coating material may be either wood rosin, rosin derivatives, waxes, fatty derivatives, sterols, long chain sterol esters and sulfur, as described above. Alternatively, the coating material may comprise any version of a synthetic latex, insoluble in water as described above. The apparatus and process as described below are particularly useful for making solid particles for crop protection, coated, which in particular have hitherto been too small in diameter to be achieved, ie those having a diameter in the range of 0.5. at 50 micrometers (μ), and in particular those having a diameter of less than 30 micrometers (μ). Furthermore, with the apparatus and process of the present invention, the force of the gas stream can be varied so that the particles released in the turbulence zone do not adhere to each other, resulting in a composition in which there is only one solid, individual particle in the core of each coating. Also, the solid, coated particles are not agglomerated, so that two or more individual particles do not adhere together by the coating. Therefore, this non-agglomeration, in particular, where the coated particles have a diameter in the range of about 5.0 to 50 micrometers (μ), was not possible with the processes of the prior art. In this manner, the size distribution of the solid, coated, non-agglomerated particles made by the apparatus and process of the present invention is such that a greater percentage of coated particles have a smaller diameter than could be previously achieved by the processes of the prior art. An implementation of the apparatus and the process as described below makes it possible for a very small, crystalline solid particle to be coated directly with a coating material, without the need for a suspension liquid, which is used in the prior art. In this implementation, which is the preferred implementation for the present invention, the coating material is in molten form before it is coated on the solid particle. By melt material is meant any substance at a temperature or above its melting point, but below its boiling point. When the coating material in a molten material, a liquid consisting of or comprising the coating material (it is understood that the liquid may include different components than only the coating material) is used in the apparatus and the process of the present invention. A less preferred form for the coating material of the present invention is where the coating material does not dissolve in a liquid, i.e., a slurry, where the slurry may comprise components other than the coating material. Examples of a slurry include an aqueous latex, or a colloidal form of a slurry, as described above. The least preferred form for the coating material of the present invention is where the coating material is dissolved in a liquid, i.e., a solution, where the solution may comprise components other than the coating material. An example of a solution is aqueous ammonia. An apparatus for coating a particle for crop protection, solid with a coating material according to the present invention is shown generally at 10 in Figure 1. The apparatus of the present invention comprises a first chamber, shown in FIG. 12 in Figures 1 and 2. A restrictor or flow reducer 14 is positioned at one end of the first chamber. The flow restrictor is typically placed at the downstream end of the first chamber, as shown in Figures 1 and 2. The flow restrictor 14 has an outlet end 14a, as shown in the detailed view of Figure 2 Although the flow restrictor is shown as a different element of the first chamber, it can be integrally formed with it, if desired. The flow restrictor of the present invention may have various configurations, since it serves to restrict the flow and thereby increases the pressure of the fluid that passes through it. Typically, the flow restrictor of the present invention is a nozzle. A first inlet line 16, or liquid, as shown in Figures 1 and 2 is placed in fluid communication with the first chamber for dosing a liquid comprising a coating material in the chamber. The liquid inlet line 16 measures the coating material in the first chamber 12 at the outlet of the flow restrictor 14, and preferably at the center of the flow restrictor when viewed along the axial length thereof. The liquid comprising the coating material is measured through the liquid inlet line 16 by a metering pump 18 of a storage vessel 20 containing the liquid as shown in Figure 1. It should be noted that when the The coating material is a molten material, the storage container 20 must be heated to a temperature above the melting temperature of the coating material in order to keep the coating material in molten form. The apparatus for coating a solid particle further includes a second inlet line 22 or gas, arranged in fluid communication with the first chamber as shown in Figures 1 and 2. In general, the gas inlet line should be placed in fluid communication with the first chamber upstream of the flow restrictor. The gas inlet line 22 injects a first gas stream through the flow restrictor to create a turbulence zone at the output of the flow restrictor. Turbulence secures the coating material to shear forces that atomize the liquid comprising the coating material. The first gas stream must have a sufficient stagnation pressure to accelerate the gas to at least one half the speed of sound, or greater, before entering the flow restrictor to ensure that a zone of turbulence of sufficient intensity will be formed in the output of the flow restrictor. The speed of sound for a particular gas stream, for example, air or nitrogen, will be dependent on the temperature of the gas stream. This is expressed by the equation for the speed of sound, c: c = VkgRT d) where = ratio of specific heats for the gas g = acceleration of gravity R = universal gas constant T = absolute temperature of the gas. In this way, the acceleration of the first gas stream is dependent on the temperature of the gas. As noted above, this is the pressurized gas that causes atomization of the liquid comprising the coating material. The pressure of this liquid in the liquid inlet line only needs to be sufficient to overcome the system pressure of the gas stream. It is preferable that the liquid inlet line has an axial length extended before the turbulence zone. If the liquid inlet line is too short, the flow restrictor becomes clogged. The apparatus of the present invention also comprises means placed on the second inlet and upstream line of the flow restrictor for heating the first gas stream prior to injection through the flow restrictor. Preferably, the heating means comprises a heater 24 as shown in Figure 1. Alternatively, the heating means may comprise a heat exchanger, a resistance heater, an electric heater, or any type of heating device. heating. The heater 24 is placed on the second inlet line 22. A pump 26 as shown in Figure 1, transports the first gas stream through the heater 24 and into the first chamber 12. When the coating material is a material When melted, the gas stream must be heated to a temperature of, or above the melting temperature of the molten material, to keep the molten material in liquid (ie molten) form. When a molten material is used, it is also helpful if auxiliary heat is provided for the first inlet line that supplies the molten material for injection, to prevent clogging of the line. The apparatus of the present invention further includes a hopper 28 as shown in Figures 1 and 2. The hopper 28 introduces a solid particle, and in particular, a crystalline, solid particle to the turbulence zone. It is preferable that the outlet end of the flow restrictor be placed in the first chamber below the hopper in the centerline of the hopper. This serves to ensure that the solid particles are introduced directly into the zone of turbulence. This is important because this increases operability by providing a configuration for feeding the solid particles more easily. Furthermore, as noted above, the turbulence holds the liquid comprising the coating material at shear forces that atomize this liquid. In addition, the cutting forces disperse and mix the atomized liquid with the solid particles, which allows the particles to be coated. It should be noted that with the present invention, when the coating material is in molten form, it is possible to directly coat the solid particle with the molten material, without the use of a suspension liquid. The hopper 29 can be fed directly from a storage container 30 as shown by the arrow 29 in Figure 1. The hopper of the present invention can include a dosing device for accurately dosing the particles in a particular relationship to the liquid fed from the liquid inlet line 16 in the turbulence zone. This dosage establishes the level of coating on the solid particle. Typically, the hopper of the present invention is opened to the atmosphere. When the coating material is a molten material, it is preferred that the solid particles are at room temperature because this facilitates solidification of the molten material after melting, which is initially at a higher temperature, coating the solid particle in the area of turbulence. The apparatus of the present invention may further include a second chamber 32 surrounding the first chamber as shown in Figures 1 and 2., the second chamber encloses the turbulence zone. The second chamber 32 has an inlet 34 for introducing a second gas stream into the second chamber. The entrance of the second chamber is preferably located at or near the upstream end of the second chamber 32. The outlet of the second chamber 32 is connected to a collection container, such as that shown at 36 in Figure 1. The second gas stream cools and transports the solid, coated particles to the collection container as illustrated by arrow 31 in Figure 2. In particular, when a solution or slurry is used, the solid of the solution or slurry thickens. it cools between the turbulence zone and the container to form a solid coating on the particle during the time the particle reaches the container. When a molten material is used, the coating material is cooled between the turbulence zone so that during the time the particle reaches the container, the solid coating is formed on the particle. The first gas stream, as well as the second gas stream, is discharged through the upper part of the collection vessel 36.

For the configuration as shown in Figures 1 and 2, the inlet 34 can be connected to a blower or fan, not shown, which supplies the second gas stream to the second chamber. However, the blower and the second chamber 32 can be removed, and the first gas stream can be used to cool the particles and to transport them to the container 36. In this case, the solid of the solution or slurry or the molten material it cools and solidifies on the particle in the atmosphere between the turbulence zone and the collection vessel and the coated particles fall into the collection vessel 36. It is preferable that the axial length of the turbulence zone be approximately ten times the diameter of the the second camera. This allows the presence at the output of the flow restrictor to be at a minimum. The solid particles are fed into the second chamber 32 as shown in Figures 1 and 2 near the outlet of the flow restrictor, which is preferably placed on the centerline of the hopper. If the pressure at the outlet is very large, the solid particles will flow back into the hopper.

The pressure of the second gas stream must be sufficient to assist in the transport of the solid particles, coated from the turbulence zone to the collection zone, but must be lower than the pressure of the first gas stream. This is because a relatively high speed difference between the first gas stream and the second gas stream produces a sufficient degree of turbulence to coat the solid particles. In addition, according to the present invention, there is provided a process for coating a particle for crop protection, solid with a coating material. It should be noted that the process of the present invention can be practiced using the apparatus illustrated in Figures 1 and 2, although it should be understood that the process of the present invention is not limited to the illustrated apparatus. The process comprises the steps of dosing a liquid comprising a coating material in a flow restrictor, such as the flow restrictor 14 as shown in Figures 1 and 2. The process of the present invention further comprises injecting a stream of gas, for example from a gas inlet line such as that shown at 22 in Figures 1 and 2, through the flow restrictor concurrently with the dosage of the liquid comprising the coating material in the flow restrictor, to create a zone of turbulence at the outlet of the flow restrictor. The shear stress in the turbulence zone atomizes the liquid comprising the coating material. The gas stream is heated before injecting it through the flow restrictor. The gas stream can be heated by a heater, such as heater 24 as shown in Figure 1. As noted above for the apparatus, when the liquid comprising the coating material is either a solution or a slurry , the gas stream is heated to a temperature sufficient to vaporize the liquid of the solution or slurry and leave the remaining solid thereof. When the coating material is in molten form, the gas stream must be heated to a temperature at or above the melting temperature of the molten material, to keep the molten material in a liquid (ie, molten) form. As also noted above for the apparatus, when a molten material is used, it is also useful if the auxiliary heat is provided to the first inlet line that supplies the molten material before injection, to prevent clogging of the line. The process of the present invention also comprises the step of adding a solid particle, and in particular, a solid, crystalline particle, to the zone of turbulence concurrently with the dosage of the liquid comprising the coating material and the injection of the stream of gas. This mixes the solid particle with the atomized liquid in the turbulence zone. This mixing in the turbulence zone coats the solid particle with the coating material. When the coating material used with the present invention is a molten material, it is possible to directly coat the solid, crystalline particle without the need for a suspension, as in the prior art. The solid particle is preferably measured in order to control the ratio of the solid and the liquid comprising the coating material, and thus the coating material, added in the turbulence zone. This sets the level of coating on the solid particle. When a solution or a slurry is used, such as a solution of ammonia, aqueous or an aqueous latex, respectively, the heat of the heated gas stream serves to evaporate the liquid from the solution or slurry, leaving the solid thereof. that remains to coat the particle. The mixing in the turbulence zone then coats the solid particle with the remaining solid of the solution or slurry. When a molten material is used, mixing in the turbulence zone coats the solid particle with the molten material. As noted above, the turbulence zone is formed by the injection of the high pressure gas stream through the flow restrictor. As discussed above with respect to the apparatus, it is preferable that the gas stream be accelerated to at least about one-half the speed of sound before the injection to ensure that a zone of turbulence of sufficient intensity is formed at the outlet of the flow restrictor. The residence time of the particles in the turbulence zone is determined by the geometry of the first chamber and the amount of gas injected from the gas inlet line. The average residence time of the solid particle within the turbulence zone is preferably less than 250 milli-seconds. More preferably, the average residence time of the solid particles within the turbulence zone is in the range of 25 to 250 milli-seconds. Short residence times can be achieved due to the action of the turbulence zone. Short residence times make the process of the present invention advantageous compared to conventional coating processes due to time, and therefore, the cost of the coating particles is reduced. Also, the short residence time makes possible the use of solid particles sensitive to heat, which thus prevents its chemical degradation and preserves the availaty of microbial solid particles.

Typically, the solid particles are fed from a hopper, such as the hopper 28 as shown in Figures 1 and 2, which is open to the atmosphere. As noted above for the apparatus, when the coating material is a molten material, it is preferred that the solid particles be at room temperature because this facilitates solidification of the molten material after the molten material (which is initially at a higher temperature) coats the solid particles in the turbulence zone. The process of the present invention may further comprise the step of adding a second stream of gas upstream of the turbulence zone to cool and transport the solid, coated particle. This second gas stream is added through the chamber, such as the second chamber 32 as shown in Figures 1 and 2. As explained above for the apparatus, the pressure of the second gas stream must be sufficient to help to the transport of the solid particles, coated from the turbulence zone to the collection vessel, but must be lower than the pressure of the first gas stream in order to achieve the coating. When a thick solution or suspension is used, the solid cools and solidifies on the particle in the second chamber between the turbulence zone and a collection container, such as the collection zone 36 as described above. When a molten material is used, the molten material cools and solidifies on the particle in the second chamber between the turbulence zone and the collection vessel. When a second chamber is not included, the solid or molten material cools and solidifies on the particle in the atmosphere between the turbulence zone and the collection container, and the coated particles fall into the container. The present invention will be clarified by the following Examples, which are proposed to be purely exemplary of the invention.

EXAMPLE 1 This example is directed to the encapsulation of calcium carbonate with wood rosin. The calcium carbonate powder with an average particle size of 10 micrometers (m) was coated with wood rosin using the apparatus as shown in Figures 1 and 2, and as described above. The wood rosin, which has a melting point of 120 ° C, was heated to 140 ° C and kept at this temperature in an isolated bath. This wood rosin was dosed with a peristaltic pump at a speed of 681 g / min. The atomizing air was heated to 140 ° C and used at 7.0216 kg / cm2 (100 psig). The calcium carbonate was dosed in a screw feeder at a speed of 11.340 g / min. to the hopper of the apparatus as shown in Figures 1 and 2. The wood rosin encapsulated the calcium carbonate particle at a coating level of 6%. Uncoated calcium carbonate exposed to HCl will produce carbon dioxide gas due to the chemical reaction. The encapsulation is tested by placing the encapsulated particles in a bath of hydrochloric acid (HCl). There was no immediate effervescence of calcium carbonate indicating the protection of the entire surface provided by the wood rosin.

EXAMPLE 2 This Example is directed to a sulfonylurea herbicide coated with either wax or rosin coatings, which is measured in the form of a molten material. In this Example, the tribenuron methyl sulfonylurea herbicide, having a particle size ranging from about 2 to about 40 micrometers (m), was metered into a screw feeder at a rate of 600 g / min. The sulfonylurea herbicide was coated with rosin at 190 ° C, dosed with a gear pump at a speed of 75.6 g / min., Which corresponds to a coating level of 12.6% rosin, ie the weight of the coating of Rosin was 12.6% of the weight of the coated particle. A second batch of sulfonylurea herbicide was coated with wax at 110 ° C, dosed with a peristaltic pump at a speed of 56.4 g / min., which corresponds to a coating level of 9.4% wax. The wax was a mixture of a low molecular weight, partially oxidized polyethylene (EPOLENE E10) and paraffin. A first gas stream comprising nitrogen was injected through a flow restrictor, where the gas stream was at a pressure of 2.668-2.808 kg / cm2 (38-40 psi) just before the flow restrictor. The sulfonylurea herbicides are normally degraded in the presence of hormonal / phenoxy herbicides, such as 2, 4-D sodium and 2,4-D acid. In this way, the effectiveness of the coatings to inhibit this degradation was tested by measuring the degradation of the sulfonylurea herbicide when mixed in mixtures of 1/20 by weight with 2,4-D of sodium and acid 2, 4-D and It was aged for three weeks at 45 ° C. The uncoated sulfonylurea herbicide was tested in the same manner to provide control. The results were as follows: PERCENTAGE OF RELATIVE DEGRADATION OF TRIBEURON ETHEL Uncoated Coating 12.6% Wax Rosin Coating 9.4% 2, 4-D sodium 38.4% 0.0% 0.0% Acid 2, 4-D 21.2% 0.0% 1.7% Thus, the results show that the coating at a level of 12.6% by weight essentially results in the encapsulation of the particles. In general, degradation of 5% or less is suitable for such formulations. Additionally, sulfonylurea coated with wax and rosin was mixed with an ethoxylated silicone surfactant and water, and then sprayed on wild buckwheat, spring wheat and wild mustard. Both the efficiency for weed damage and the safety for spring wheat was equivalent for the coated or uncoated sulfonylurea herbicides. EXAMPLE 3 This example is directed to a relatively water soluble herbicide, bromacil (5-bromo-3-sec-butyl-6-methyluracil), having 815 ppm of water solubility, coated with stearic acid. In this example, solid bromacilous particles, having a particle size range of less than 1 μ to 30 μm maximum diameter, were dosed in a screw feeder at a rate of 1000 g / min. The bromacil was coated with stearic acid in the form of a molten material at a rate of 60 g / min. The stannic acid, which had a melting point of 70 ° C, was heated to 90 ° C and kept at this temperature in a storage vessel, such as a storage vessel 20 as described above. This coated material from the first step was collected and coated a second time, corresponding to a coating level of 6% and 12% in the first step and second step, respectively, although it should be noted that this is not necessary to coat the particles with more than one step in order to encapsulate the particles. A gas stream comprising nitrogen was injected through a flow restrictor, such as that shown in Figures 1 and 2. The gas stream was at a pressure of 4,915 kg / cm¿ (70 psi) just before the restrictor. flow . The particle size measurements were made using a Sympatec Helos. The Helos uses forward light scattering or scattering to measure the particle size distribution. A well-dispersed stream of dry particles is passed through a beam of collimated laser beams. The resulting diffraction pattern was simplified into a size distribution. The following table shows the particle size analysis of the uncoated bromacil, the bromacilo coated from the first step and bromacilo coated from the second step.

Diameter in Bieracilic Beams Coated against uncoated Fraction of Stearic Acid 6% acid 11.9% acid Bromacillic Stearic Zero Stearic Particle Without first step Second step Coating 5% smaller 0.7 0.8 0.9 than 10% smaller 1.0 1.2 1.3 than 16 % lower 1.3 1.8 1.9 than 50% lower 4.6 5.5 5.4 than 90% lower 12.0 20.0 19.3 than Each of the bromacil size fractions were coated, and the size analysis shows that the coated particles exist as non-agglomerated, discrete, individual particles. The tiniest particles were still present, but with a slight increase in size as a result of being coated.

EXAMPLE 4 This Example is directed to a sulfonylurea herbicide coated with wood rosin (melting point 50-54 ° C) which was then further mixed with an associated low melting herbicide in a carrier. In this Example, the chlorimuron ethyl sulfonylurea herbicide, having a particle size ranging from about 2 to about 40 μ, was metered into a screw feeder at a rate of 1000 g / min. The chlorimuron ethyl sulfonylurea herbicide was coated in successive steps with rosin at 185-190 ° C, dosed with a peristatic pump at a rate of 81 g / min, which corresponds to a final coating level of 27.5% rosin, that is, the weight of the rosin coating was 27.5% of the weight of the coated particle. A first gas stream comprising nitrogen was injected through the flow restrictor, where the gas stream was at a pressure of 43-.915 kg / cm2 (70 psi) just before the flow restrictor. Sulfonylurea herbicides are normally degraded in the presence of organophosphorus herbicides, such as anilofos. In this way, the effectiveness of the coating to inhibit this degradation was tested by measuring the degradation of the chlorimuron ethyl sulfonylurea herbicide when mixed in 1/100 wt. Mixtures with anilophos (present as 50% loaded silica) and aged for two weeks at 54 ° C. The chlorimuron ethyl sulfonylurea herbicide was tested in the same manner to provide control. The results were as follows: PERCENTAGE OF RELATIVE DEGRADATION OF CLORIMURON ETILO Uncoated Rosin coating 27.5% Anilofos on silica 56% 0.0% In this way, the results show the coating at a level of 27.5% by weight which essentially resulted in the encapsulation of the particles.

EXAMPLE 5 This example is directed to the preparation of a wax-coated herbicide which is then subsequently mixed with anilophos on silica, in Example 6. In this Example, the metsulfuron methyl sulfonylurea herbicide, having a particle size varying from about at approximately 40 μ was dosed in a screw feeder at a rate of 512 g / min. The methylsulfuron methyl that was coated was at 154 ° C, was dosed with a peristaltic pump at a speed of 64 g / min., Which corresponds to a coating level of 8.4% wax. The coating was a mixture of a low molecular weight, partially oxidized polyethylene (EPOLENE ElO) and paraffin. A gas stream comprising nitrogen was injected through a flow restrictor, where the gas stream was at a pressure of 4,915 kg / cm ^ (70 psi) just before the flow restrictor.

EXAMPLE 6 In this Example, the coated sulfonylureas (5, 6 from the list below) of Example 4 and 5 were subsequently mixed with a milled mixture with anilofos hammer, wetting agent, dispersant, and diluent (1,2,3,4 of the list below) to give a wettable, chemically stable powder. 1. 60% of anilophos on silica 4.17 g 2. Morwet D425 * 1.00 g 3. Morwet EFW ** 0.20 g 4. Celite 209 *** 4.57 g 5. Metsulfuron methyl coated 0.028 g with wax of Ex.5 6. Chloride ethyl coated with 0.035 g rosin of Ex.4 * a common anionic dispersant, condensed naphthalene sulfonate, sold under the trademark "MORWET'®" D425 by the Witco Corporation of Greenwich, Connecticut ** an anionic, common wetting agent, alkyl naphthalene sulfonate, sold under the trademark "MORWET®" EFW by the Witco Corporation of Greenwich, Connecticut. *** a carrier of diatomaceous earth, expired under the commercial name "CELITE" 209 by the Celite Corporation of Lompac, California. The coated methyl methosulfuron and ethyl chlorimuron (ingredients 5 and 6 in the above list) were extracted from the wettable powder (ingredients 1-6 in the previous list) and each one was tested by High Liquid Chromatography Pressure (CLAP) at 25 ° C for its chemical identity.

These coated sulfonylureas were aged at an accelerated rate for 2 weeks at 54 ° C and again tested by CLAP. As can be seen from the subsequent results, the same amount of coated sulfonylurea was quantified by CLAP after accelerated aging. In this way, the sulfonylureas coated according to the present invention had excellent chemical stability.

Assay (CLAP) sample at 25 ° C-0.20% metsulfuron methyl (non-aged) sample at 54 ° C-0.20% metsulfuron methyl (aged) sample at 25 ° C-0.25% ethyl chlorimuron (not aged) sample at 54 ° C-0.25% ethyl chlorimuron (aged) In comparable tests on metsulfuron methyl and uncoated ethyl chlorimuron, the respective uncoated sulfonylurea decomposed during accelerated aging, so that there was much less sulfonylurea in the aged formulation. In addition, aged, metsulfuron methyl and chlorimuron ethyl were tested by a Long Tube Sedimentation (LTS) test, which indicates the dispersion integrity of a solid formulation back to individual particles. Only 0.001 ml of large particles resulted from the bottom of the sedimentation tube after 1 minute, 0.002 ml resulted after 3 minutes, and 0.004 resulted after 5 minutes. In this way, the coated sulfonylureas made in accordance with the present invention had good dispersion properties. Additional advantages and modifications readily occur to those skilled in the art. Therefore, the invention, in its broader aspects, is not limited to the specific details, representative apparatus and illustrative examples shown and described. Accordingly, deviations from such details can be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Having described the invention as above, the content of the following claims is claimed as property.

Claims (20)

1. A composition for the protection of crops, characterized in that it comprises a solid particle for the protection of crops, mononuclear, coated with water-insoluble coating material, wherein the coating material is selected from the group consisting of: wood rosin, derivatives of rosin, waxes, fatty derivatives, sterols, long-chain sterol esters and sulfur, and the diameter of the composition for crop protection is in the range of 0.5 to 50 micrometers.

2. The composition for the protection of crops according to claim 1, characterized in that the rosin derivatives are selected from the group consisting of: partially dimerized rosin, partially hydrogenated rosin, divalent metal salts, tri-valent metal salts, adducts of maleic acid / anhydride, fumaric acid / anhydride adducts and pentaerythritol adducts.

3. The composition for crop protection according to claim 1, characterized in that the wax is selected from the group consisting of natural waxes and synthetic waxes.

4. The composition for crop protection according to claim 1, characterized in that the fatty derivatives are selected from the group consisting of acids, metal salts of the acids, acid amides, alcohols and esters.

5. A composition for the protection of crops, characterized in that it comprises a solid, mononuclear, crop protection particle coated with a water-insoluble coating material, wherein the coating material is a synthetic latex polymer selected from the group consisting of of: a homopolymer of a first group of monomers and a co-polymer made from the first group of monomers combined with at least one monomer of a second group of monomers, and the diameter of the composition for crop protection is in the range of 0.5 to 50 micrometers.

6. The composition for crop protection according to claim 15, characterized in that the first group of monomers includes ethylene, propylene, styrene, alpha-methylstyrene, vinyl chloride, alkyl acrylate, alkyl methacrylate, vinyl acetate, tetrafluoroethylene, acrylonitrile, alkylene, chloroprene, divinylbenzene and vinylalkyl esters, and the second group includes acrylic acid, methacrylic acid, vinyl alcohol, vinyl pyrrolidone and acrylamide.

7. The composition for crop protection according to claim 5, characterized in that the second group of monomers includes acrylic acid, methacrylic acid, vinyl alcohol, vinyl pyrrolidone and acrylamide.

8. A crop protection composition, characterized in that it comprises a solid, mononuclear crop protection particle coated with a water insoluble coating material, wherein the coating material is a synthetic latex polymer selected from the group consisting of : poly (ethylene terephthalate), polyamide resin, synthetic polyterpene, synthetic poly (beta-pinene) and cellulose esters, and the diameter of the composition for crop protection is in the range of 0.5 to 50 micrometers.

9. The crop protection composition according to any of claims 1, 5 or 8, characterized in that the solid culture protection particle comprises a low melting active substance and a solid, porous, inert carrier particle, and the low melting point active substance is absorbed in the solid, porous, inert carrier particle.

10. The composition for crop protection according to any of claims 1, 5 or 8, characterized in that the particle for the protection of crops, solid is a herbicide.

11. The composition for crop protection according to claim 10, characterized in that the herbicide is a sulfonylurea.

12. The composition for crop protection according to claim 11, characterized in that the coating is a mixture of low molecular weight, partially oxidized polyethylene and paraffin, and the sulfonylurea is tribenuron methyl.

13. A process for coating a particle for crop protection, solid with a coating material, the process is characterized in that it comprises the steps of: (a) dosing a coating material in a flow restrictor; (b) injecting a gas stream through the flow restrictor concurrently with step (a) to create a turbulence zone at the outlet of the flow restrictor, whereby the coating material is atomized; (c) heating the gas stream before injecting the gas stream through the flow restrictor; and (d) adding a particle for crop protection, solid to the zone of turbulence concurrently with steps (a) and (b) for mixing the solid particle with the atomized coating material, wherein mixing in the turbulence zone coats the particle for crop protection, solid with the coating material to form a crop protection composition having a diameter in the range of 0.5 to 50 micrometers.

14. A product made by the process according to claim 13.

15. A crop protection mixture, characterized in that it includes: (a) a crop protection partner comprising a solid particle; and (b) a crop protection composition comprising: a solid mononuclear crop protection particle coated with a water insoluble coating material, wherein the coating material is a synthetic latex polymer selected from the group which consists of: a homopolymer of a first group of monomers and a co-polymer made from the first group of monomers combined with at least one monomer of a second group of monomers, and the diameter of the composition for crop protection is in the range from 0.5 to 50 micrometers.

16. A crop protection mixture, characterized in that it includes: (a) a crop protection partner comprising a solid particle; and (b) a crop protection composition, comprising: a solid, mononuclear crop protection particle coated with a water insoluble coating material, wherein the coating material is a latex polymer, synthetic, selected from the group consisting of: poly (ethylene terephthalate), polyamide resin, synthetic polyterpene, synthetic poly (beta-pinene) and cellulose esters, and the diameter of the composition for crop protection is in the range of 0.5 to 50 micrometers

17. A crop protection mixture, characterized in that it includes: (a) a crop protection partner comprising a solid particle; and (b) a composition for crop protection, comprising: a solid, mononuclear, crop protection particle coated with a coating material, wherein the coating material is selected from the group consisting of: wood rosin , rosin derivatives, waxes, fatty derivatives, sterols, long-chain sterol esters and sulfur, and the diameter of the composition for crop protection is in the range of 0.5 to 50 micrometers.

18. The mixture according to claim 17, characterized in that the solid particle of the composition is a sulfonylurea and the weight ratio of the sulfonylurea to the weight of the associate is in the range of about 1/10 to 1/200.

19. The mixture according to claim 18, characterized in that the partner is 2,4-D (2,4-dichlorophenoxyacetic acid), the sulfonylurea is tribenuron-methyl, and the coating material is a mixture of low molecular weight polyethylene, partially oxidized and paraffin.

20. The mixture according to claim 18, characterized in that the associated is 2,4-D (2,4-dichlorophenoxyacetic acid), the sulfonylurea is tribenuron-methyl and the coating material is wood rosin. SUMMARY OF THE INVENTION A composition comprising a solid mononuclear crop protection particle coated with a water insoluble coating material has a diameter in the range of 0.5 to 50 μ. This composition is made by a process that results in substantial non-agglomeration of the coated particles. In a particular embodiment, a crop protection composition comprises a solid, mononuclear crop protection particle coated with either wood rosin, rosin derivatives, waxes, fatty derivatives, sterols, chain sterol esters. long and sulfur. Alternatively, the coating material may be a synthetic latex polymer, insoluble in water. The composition can be used in a mixture that also includes a chemical crop protection partner comprising a solid particle. The associate ordinarily degrades the particle for crop protection, solid when it is stored or aged together as a mixture of solid particles. However, when the solid particle of the composition is coated, this degradation is prevented.