JP2003137682A - Method of manufacturing coated bioactive granular material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a coated bioactive granular material from which volatile materials are removed by removing the volatile materials existing in the coated bioactive granular material obtained by spraying a coating material to the surfaces of core material particles containing bioactive materials and drying the coatings by ventilation of hot air. SOLUTION: The coated bioactive granular material removed with the volatile materials is manufactured by ventilating the coated bioactive granular material with the hot air at a ventilation rate below the minimum fluidization velocity of the coated bioactive granular material.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to hot air blowing of volatile substances present in coated bioactive particulates obtained by spraying and drying a coating on the surface of core material particles containing the bioactive substance. A method for producing a coated bioactive particle from which volatile substances have been removed by aeration by removing a volatile substance, characterized in that hot air is aerated at an aeration rate that is less than the minimum fluidization rate of the coated bioactive particle. The method for producing a coated bioactive granule from which volatile substances have been removed.

[0002]

2. Description of the Related Art If a volatile substance remains in a coated bioactive granular material obtained by spraying and drying a coating material on the surface of core material particles containing the biologically active substance, the coated biological material It is known that the function of controlling the elution of biologically active substances is impaired during storage of active granules (Japanese Patent Application No. 10-3545).
No. 86). It is known that the step of removing the volatile substance is effective for eliminating this, and a method of removing the volatile substance by aeration of hot air is known.

[0003]

However, although the volatile substances are removed by aeration of hot air, the coating film may be damaged and the elution control function of the bioactive particulate matter as the core material may be impaired. In addition, when hot air was aerated, there was a bias, and the concentration of volatile substances in the particulates was also biased.

[0004]

DISCLOSURE OF THE INVENTION The present inventors have conducted intensive studies in view of the above-mentioned problems of the prior art. as a result,
By lowering the concentration of volatile substances contained in the coated bioactive particles by aerating hot air at a certain level or less, it is possible to produce coated bioactive particles from which volatile substances have been removed without impairing the elution function. The present invention has been completed based on the findings and this finding. As is clear from the above description, an object of the present invention is to provide a method for producing a coated bioactive granular material from which volatile substances have been removed without impairing the elution function.

[0005]

The present invention comprises the following. (1) Volatile by removing the volatile substances present in the coated bioactive particles obtained by spraying and drying the coating material on the surface of the core material particles containing the bioactive substance by aeration with hot air A method for producing coated bioactive granules having depleted substances, characterized in that hot air is vented at an aeration rate that is less than the minimum fluidization rate of the coated bioactive granules. Method of manufacturing granular material.

(2) Aeration rate (wind speed) of hot air is 200c
The method for producing a coated bioactive granular material from which volatile substances have been removed according to claim 1, which has a m / sec or less.

(3) The method for producing coated bioactive granules from which volatile substances have been removed according to the above item 1, wherein the coated bioactive granules are those having an average particle diameter of 0.3 to 10 mm.

(4) The volatile substance according to the above-mentioned item 1, wherein the temperature of the hot air is less than (T-5) ° C when the melting point of the thermoplastic resin in the coating material is T ° C. Of the coated bioactive granules having been removed.

(5) The method for producing coated bioactive particulates from which volatile substances have been removed according to the above item 1, wherein the hot air aeration time is 0.05 to 2 hours.

(6) The method for producing coated bioactive particles from which volatile substances have been removed according to the above item 1, wherein the coating method is a method of spraying a coating material solution.

(7) The method for producing a coated bioactive granular material from which volatile substances have been removed according to the above item 1, wherein the coating material is a thermoplastic resin.

(8) The method for producing coated bioactive particles from which volatile substances have been removed according to the above item 1, wherein the coating material is an olefin polymer.

(9) The method for producing coated bioactive particles from which volatile substances have been removed according to the above-mentioned item 1, wherein the core material particles containing the bioactive substance are fertilizers.

(10) The coated bioactive granular material has a specific gravity of 0.5.
The method for producing coated bioactive granules from which volatile substances have been removed according to claim 1, which is a granule having ˜3 g / ml.

(11) The method for producing a coated bioactive granular material from which volatile substances have been removed according to the above item 7, wherein the fertilizer is urea.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below. The bioactive substance in the present invention is used for the purpose of growing crops, useful plants, plants such as agricultural products, protection, and increasing the yield depending on the purpose of use, improving the quality of crops, controlling diseases, and controlling pests. , Pest control, weed control, and further effects such as growth promotion, growth suppression and dwarfing of agricultural crops, and specific examples thereof include fertilizers, pesticides and microorganisms. Especially when used for coated bioactive granules,
When the bioactive substance is a fertilizer or a pesticide, a relatively high effect is obtained for its intended use.

As fertilizers, nitrogenous fertilizers, phosphate fertilizers,
In addition to potassium fertilizers, fertilizers containing essential plant elements such as calcium, magnesium, sulfur, iron, trace elements and silicon can be cited.

Specific examples of the nitrogenous fertilizer include ammonium sulfate, urea, and ammonium nitrate, as well as isobutyraldehyde condensed urea, acetaldehyde condensed urea, and the like. Phosphoric fertilizers include superphosphate lime, molten phosphorus fertilizer, and calcination. Examples of the fertilizer include phosphorus fertilizer and the like. Examples of the potassium fertilizer include potassium sulfate, chloride chloride, and silicic acid fertilizer, and the form thereof is not particularly limited. Further, advanced chemical fertilizers and compound fertilizers having a total content of the three components of the fertilizer of 30% or more, and further organic fertilizer may be used. Further, a fertilizer to which a nitrification inhibitor, urease inhibitor or pesticide is added may be used.

As pesticides, disease control agents, pest control agents,
Examples include pest control agents, weed control agents, and plant growth regulators. The disease control agent is an agent used for protecting agricultural crops and the like from harmful effects of pathogenic microorganisms, and mainly includes bactericides. The pest control agent is a chemical agent for controlling pests such as agricultural crops, and is mainly an insecticide.
The pest control agent is an agent used for controlling plant parasitic mites, plant parasitic nematodes, field worms, birds and other harmful animals that harm agricultural crops and the like. The weed control agent is a chemical agent used for controlling plants and plants that are harmful to agricultural crops and trees, and is also called a herbicide. The plant growth regulator is a drug used for the purpose of enhancing or suppressing physiological functions of plants.

The pesticide is preferably a solid powder at room temperature, but may be a liquid at room temperature. In the present invention, the pesticide may be water-soluble, sparingly water-soluble, or water-insoluble, and is not particularly limited. The pesticide may be one kind or may be composed of two or more kinds of complex components.

As the microorganism which is one of the bioactive substances, one having an effect of suppressing the propagation of pathogenic microorganisms can be used. What can be preferably used is an antibacterial active substance-producing bacterium. Specifically, it is a Pseudomonas bacterium having a high antibacterial substance-producing ability, for example, as a strain producing an antibiotic, Pseudomonas cepacia producing the antibiotic pyrrolenitrin, antibiotics phenazinecarboxylic acid and pyrrolenitrin, piortheolin, Pseudomonas producing cyanide, diacetylfuroglucinol, etc.
Further, there may be mentioned florescence, and further, a fluorescent Pseudomonas genus that produces an iron chelating substance siderophore and the like that does not allow iron in soil to be used for pathogenic bacteria but only for plants.

Examples of the other microorganisms include fluorescent Pseudomonas and Bacillus as growth-promoting rhizobacteria that produce growth-promoting substances such as Agrobacterium radiobacter, which produces bacteriocin agrosin 84, and plant hormones. . Particularly, CDU-degrading bacterial groups and strains of the genus Streptomyces have a remarkable deterrent against soil-borne pathogenic filamentous fungi and are preferably used.

The composition of the core material particles containing a bioactive substance is not particularly limited as long as it contains one or more bioactive substances. The bioactive substance may be granulated alone, and granulated using a carrier such as clay, kaolin, talc, bentonite, or calcium carbonate, or a binder such as polyvinyl alcohol, sodium carboxymethyl cellulose, or starch. It can be one. Also, if necessary, for example, a surfactant containing polyoxyethylene nonylphenyl ether, molasses, animal oil, vegetable oil, hydrogenated oil, fatty acid, fatty acid metal salt, paraffin, wax, glycerin, etc. may be contained. I do not care.

The method for granulating the core particles is not particularly limited, and examples thereof include extrusion granulation method, fluidized bed granulation method, tumbling granulation method, compression granulation method, and coating granulation method. The adsorption granulation method or the like can be used. In the present invention, any of these granulation methods may be used, but the extrusion granulation method is the simplest.

The particle size of the core particles is not particularly limited, but in the case of fertilizer, for example, 1.0 to 1
0.0 mm, and 0.3 to 3 in the case of pesticides.
It is preferably 0 mm. By using a sieve, an arbitrary particle size can be selected within the above range.

The specific gravity in the present invention is the specific gravity obtained from the volume of 100 g of the coated bioactive particles obtained by the wet method. The effect of the present invention is not particularly limited by the specific gravity of the coated bioactive granular material, but is 0.5 to 3 g / m 2.
It is preferably l. If it is less than the range, it becomes easy to flow due to ventilation, and in order to prevent the flow, a small amount of air must be used and it is difficult to obtain a sufficient ventilation effect. Further, it is difficult to obtain coated bioactive granules exceeding the above range, which is a range sufficient for industrial production.

Examples of the coating material of the coated bioactive particulate material include those containing a resin and those containing an inorganic substance such as sulfur. In the coating material containing a resin, the content ratio of the resin is preferably in the range of 10 to 100% by weight, more preferably 20 to 100, with respect to the coating material.
It is in the range of% by weight. Further, in the coating material containing the inorganic substance, the content ratio of the inorganic substance is 20 to 20% with respect to the coating material.
The range is preferably 100% by weight, more preferably 50 to 90% by weight.

The resin used for the coating material is not particularly limited, and examples thereof include thermoplastic resins, thermosetting resins, emulsions and the like. Specific examples of the thermoplastic resin include an olefin polymer, a vinylidene chloride polymer,
Examples thereof include diene polymers, waxes, polyesters, petroleum resins, natural resins, fats and oils and modified products thereof, and urethane resins.

As the olefin polymer, polyethylene, polypropylene, ethylene-propylene copolymer,
Ethylene-carbon monoxide copolymer, ethylene-hexene copolymer, ethylene-butadiene copolymer, polybutene,
Butene-ethylene copolymer, butene-propylene copolymer, polystyrene, ethylene-vinyl acetate copolymer, ethylene-vinyl acetate-carbon monoxide copolymer, ethylene-
Examples thereof include acrylic acid copolymers and ethylene-methacrylic acid ester copolymers, and examples of vinylidene chloride-based polymers include vinylidene chloride-vinyl chloride copolymers.

Examples of the diene polymer include a butadiene polymer, an isoprene polymer, a chloroprene polymer, a butadiene-styrene copolymer, an EPDM polymer and a styrene-isoprene copolymer. Here, the polyethylene may be any of high-density polyethylene (HDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and ultra-low-density polyethylene, such as melt flow rate and The molecular weight and the molecular weight distribution are not particularly limited.

Examples of the waxes include beeswax, wood wax, paraffin and the like, examples of the polyester include aliphatic polyesters such as polylactic acid and polycaprolactone and aromatic polyesters such as polyethylene terephthalate, and examples of the natural resin include: Examples thereof include natural rubber and rosin, and examples of fats and oils and modified products thereof include cured products, solid fatty acids and metal salts.

As the thermosetting resin, phenol resin,
Examples thereof include alkyd resin, unsaturated polyester, epoxy resin, silicon resin, urethane resin, and drying oil. These thermosetting resins have many combinations of monomers, but the types and combinations of the monomers are not limited in the present invention. Further, in addition to a polymer of monomers, a polymer of a dimer or a polymer, or a mixture thereof may be used.
Further, a mixture of a plurality of different types of resins may be used.

In the present invention, the volatile substance is a substance having a vapor pressure of 1 × 10 ⁻⁴ Pa or more at 25 ° C. The volatile substances contained in the coated bioactive particles include solvents used during resin polymerization (n-hexane etc.), water, surfactants, unreacted monomers, prepolymers having a low degree of polymerization, and solvents for coating material solutions. and so on.

The method of coating the surface of the core material particles containing the bioactive substance with the coating material is not particularly limited, and for example, a method of spraying a molten coating material on the surface of the core material particles, a solvent A method of spraying a coating material solution in which a coating material is dissolved on the surface of the core material particles, a method of attaching powder of the coating material to the surface of the core material particles and then melting the same, a monomer on the surface of the core material particles Examples include a method of spraying and reacting on the surfaces of the core material particles to form a resin (coating), and a dipping method in which the core material particles are dipped in a molten solution of the coating material or a coating solution.

As a method of coating the core material particles with a coating material containing a resin, a coating material solution prepared by dissolving a resin in the coating material in a solvent capable of dissolving the resin is attached to the surface of the core material particles by spraying. To form a coating (hereinafter referred to as "solution spraying method"), or a coating material melt obtained by melting the coating material by heating is adhered to the surface of the core material particles by spraying to form a coating film. A forming method (hereinafter referred to as "melting liquid spraying method") can be mentioned.

The coated bioactive particulate matter may be obtained by either method, but it has high production efficiency and
From the viewpoint of uniformity of the obtained coating film, a method of forming the coating film by spraying the coating material solution on the core material particles in a rolling or flowing state and then exposing to hot air is preferable.

The coated bioactive particles used in the present invention may be obtained by any method, but in view of high production efficiency, uniformity of the obtained coating film, etc. A solution spraying method is preferred in which the coating material solution is attached to the granular material in a fluidized state by spraying and then exposed to hot air to form a film.

The coated bioactive granules can be obtained by the above-mentioned production method, and specifically, for example, Japanese Patent Publication No. 60-3.
It can be obtained according to the method described in the embodiment section of JP-A-040.

The effect of removing the volatile substances remaining in the coated bioactive particles in the present invention is particularly remarkable when the coated bioactive particles are obtained by the solution spraying method. This is because in the solution spraying method, a large amount of solvent is used in obtaining the coating material solution, so that the concentration of volatile substances contained in the particulate matter after the coating step tends to be extremely high. Because there is.

An example of the coating apparatus used in the solution spraying method will be described with reference to the jet apparatus shown in FIG. In this method, in order to uniformly disperse the coating material insoluble in the solvent such as the inorganic filler in the coating material solution, it is necessary to vigorously stir the coating material solution.

This jetting apparatus transports the coating material dissolving liquid to the core material particles 3 in a jet state through the pipe 5, sprays it with the spray nozzle 2, and sprays it onto the surface of the core material particles 3 to spray the surface. Simultaneously with the coating, a high-temperature gas is made to flow into the jet tower 1 from the lower part into the guide tube 6, and the high-speed hot air flow instantly evaporates the solvent in the coating material solution adhering to the surface of the core material particles. It is to be dried. The gas used for drying the solvent collects the solvent in the condenser 13 and is reused.

The spraying time varies depending on the resin concentration of the coating material solution, the spray rate of the solution, the coating rate, etc., but these should be appropriately selected according to the purpose. Figure 1
As a fluidized bed type or jet bed type coating apparatus other than the jet apparatus shown in FIG.
No. 1 and Japanese Patent Publication No. 42-24282,
A device for forming a fountain-type fluidized bed of core material particles by a gas body and spraying a coating agent on the core material particle dispersion layer generated at the center can be mentioned. As a rotary type coating device, there is disclosed in Japanese Patent Application Laid-Open No. 7-31914. Japanese Patent Laid-Open No. 7-195
An apparatus for forming a coating film disclosed in Japanese Patent Application Laid-Open No. 007, in which a lifter provided on an inner circumference of a drum rotates to move the powder particles upward and then drop the powder particles to apply a coating agent to the surface of the falling particles. Can be mentioned.

As a coating apparatus other than the jet apparatus shown in FIG. 1 that can be used in the present invention, a fluidized bed type or jet layer type coating apparatus is disclosed in Japanese Examined Patent Publication Nos. 42-24281 and 42-24282. The apparatus for forming a fountain-type fluidized bed of core particles by a gas body and spraying the coating agent on the core particle dispersion layer generated at the center can be mentioned as a rotary coating apparatus. Kaihei 7-31
Japanese Patent Application Laid-Open No. 914 and Japanese Patent Application Laid-Open No. 7-195007 disclosed in Japanese Patent Application Laid-Open No. 7-195007, a lifter provided on the inner circumference of the drum by rotating the drum transfers the powder particles upward, and then drops the powder particles to coat the surface of the powder particles with a coating agent. A device for applying and forming a film can be mentioned.

When the coated bioactive particles are obtained by the solution spraying method, the solvent used is not particularly limited,
Since the solubility characteristics for each solvent differ depending on the type of resin used for coating, the solvent may be selected according to the resin used. For example, when using an olefin polymer, an olefin copolymer, a vinylidene chloride polymer, a vinylidene chloride copolymer or the like as a resin, a chlorine-based solvent or a hydrocarbon-based solvent is preferable, and among them, tetrachloroethylene, trichloroethylene, and toluene are used. If
It is a particularly preferable solvent because a dense and uniform film can be obtained.

In the present invention, the step of lowering the concentration of volatile substances contained in the coated bioactive granules comprises forming a coating film on the surfaces of the core particles, and then removing the volatile substances from the coated bioactive granules. It is a ventilation step for removing. The aeration step is effective for removing the solvent, particularly when the solution spray method is used as the coating method.

When the coating film is formed on the surface of the core material particles a plurality of times and then the final product is obtained, ventilation may be carried out after the coating film has been completely formed. You may ventilate every time. In addition, the ventilation process,
It may be performed in the above-mentioned coating device, or may be performed by a ventilation device separately from the coating device.

In order to treat with a gas containing almost no volatile substance, a gas containing almost no volatile substance is obtained, and after spraying the coated bioactive granules, a space for ventilation is provided. Should be quickly discharged from. The effect of removing volatile substances can be obtained regardless of the temperature of the gas, but a higher effect can be obtained by selecting an appropriate temperature.

When the gas after the aeration treatment is circulated and reused, the harmful effect can be alleviated by using the gas after separating and purifying the volatile substances by using activated carbon or the like and then using the gas again. The concentration of volatile substances in the gas is preferably below the dew point.

The state of the coated bioactive particles during the aeration treatment is not particularly limited, but is preferably in a fluid or rolling state. When performing the aeration treatment with the gas, it is preferable to consider an aeration inflow method or a shape of an aeration device that does not cause a nonuniform flow of the gas in the aerated coated bioactive particulate matter.

The temperature of the coated bioactive granules preferable for aeration is not particularly limited, but when the coating material contains a thermoplastic resin, the melting point of the thermoplastic resin contained in the coating material is T ° C. In that case, the temperature is preferably lower than (T-5) ° C. When the thermoplastic resin is single, the melting point of the resin is T ° C., and when there are two or more kinds, the melting points of the respective resins are compared and the higher melting point is T ° C. However, when the aeration treatment is carried out under the temperature condition and the inconvenience that the coated bioactive particles are aggregated with each other occurs, it is preferable to perform the treatment at a temperature not higher than the melting point of the resin having a lower melting point. The melting point of the resin can be measured using a known analyzer such as DSC. When the aeration treatment with the gas is performed, the temperature of the coated bioactive particles can be controlled by appropriately adjusting the temperature of the gas. If the melting point of the component contained in the core material particles or the temperature at which it deteriorates is lower than the melting point of the resin used for the coating, this is designated as T.

The aeration time is not uniform depending on the thickness of the coating and the concentration of volatile substances contained in the coated bioactive particles immediately after production, but is preferably 0.05 to 2 hours. The volatile substances removed by aeration from the coated bioactive particles immediately after coating can be recovered by, for example, cooling, compression, or an adsorbent such as activated carbon. Therefore, volatile substances can be reused in the coating process by recycling without being discharged as waste, which is environmentally friendly.
It can be said that this is also a preferable treatment method in terms of cost. In particular, when recovering a large amount of volatile substances, a method of recovering with a condenser is effective. When using a condenser, the cooling temperature is affected by the concentration of volatile substances after recycling. The amount of volatile substances remaining in the coated bioactive particles is greatly influenced by the concentration of volatile substances contained in the recycle gas obtained by separating and purifying the volatile substances. A method using activated carbon is effective as a method for reducing this concentration.

However, a method for separating and purifying volatile substances suitable for treating low-concentration volatile substances such as activated carbon is such that the treatment of a gas containing high-concentration volatile substances or a large amount of gases requires It is not suitable because the processing capacity drops sharply.

Therefore, the coated bioactive particles after coating are subjected to primary aeration by a method using a recirculating gas obtained by separating and purifying volatile substances with a condenser suitable for treating a large amount of volatile substances with high concentration. Secondary aeration using a method suitable for separating and purifying low-concentration volatile substances enables efficient and effective removal to low concentrations. The removal method by secondary aeration is not particularly limited, and examples thereof include a method of heating the coated bioactive particulates to the extent that the coating is not damaged by hot air, infrared irradiation, microwave, reduced pressure, reduced pressure hot air, steam blowing, or the like. be able to. A method of separating and refining the recirculated gas by secondary aeration is a method in which the method of treating with activated carbon has a high separation and refining ability and is excellent in the effect of lowering the volatile substance concentration of the coated bioactive substance, which is a preferable method.

The activated carbon used can be reused by removing volatile substances by heating. The volatile substances generated at this time can be recovered by cooling or compression cooling. Further, the primary ventilation can be performed by circulating a ventilation gas in the coating device that has performed the coating. Since this method can be manufactured without having a primary ventilation device separately from the coating device, it is effective in reducing the manufacturing cost and is a preferable method.

In order to prevent the coating applied to the particles from being damaged by the aeration treatment and the dissolution control from being impaired, the present inventors have achieved this by aerating the particles in a non-flowing state. Found.

The ventilation device is not particularly limited.
For example, a method of allowing particles to stand in a cylindrical tank and ventilating the particles upward from below can be exemplified. Further, the particles may be stirred. As for the stirring method, in order to prevent the coating from being damaged by stirring, stirring by rolling of the apparatus is preferable to stirring by stirring blades. Even in this case, it is preferable that the stirring is gentle enough to avoid damage to the coating.

The air volume of the ventilation gas in the present invention is preferably less than the minimum flowing air volume. When the content is more than the above range, the coated bioactive granules flow, and the coating is easily scratched by the physical external force, and the generation of scratches impairs the elution control.

The wind velocity lower than the minimum fluidization velocity in the present invention means a state in which a gas in a state where particles are not in a fluidized state is flowing upward from below. Here, the minimum fluidization rate (Umf) is a value calculated by the following formula. Umf = (dp ^ 2 × (ρs−ρf) g) / (1650
× μ) (when Ar <1.9 × 10 ^ 4) Umf = (dp × (ρs−ρf) g) / (24.5 ×
ρf) (when Ar> 2.45 × 10 ^ 7) where Ar = (dp ^ 3 × ρf × (ρs−ρf) g) μ ^ 2
(Ar: Archimedes number) dp: Particle diameter (m) ρs: Particle density (kg / m3) ρ
f: Fluid density (kg / m3), μ: Fluid viscosity (Pa · s)
g: Gravity acceleration (m / s2) (Chemical Engineering February 1988 issue P.
64 (Assistant Professor Kamimaki, Hokkaido University) "

Further, if the hot air velocity is 200 cm / sec or less, it is possible to industrially ventilate a general coated bioactive granule, which is a preferable air flow range. If it is below the range, the flow of the ventilation gas in the ventilation device becomes uneven, and the ventilation state of the coated bioactive granules tends to become uneven. When the content is more than the above range, the air volume of a general coated bioactive granular material starts to flow and the cost becomes higher in industrial production as compared with the aeration effect.

The particle size of the coated bioactive granules varies from 0.3 mm to 1 depending on the core particles, as described above.
The range of 0 mm is preferable. When it is below the range, the resistance becomes large when a sufficient amount of air is passed for aeration in the aeration step, and the coated bioactive particles easily flow. If it is above the range, the workability of applying the coated bioactive granules to plants may deteriorate.

The concentration of the volatile substance contained in the coated granular material is preferably 500 ppm or less, and 100 ppm or less, in order to avoid a change in the elution control during storage of the coated granular material. It is possible to favorably suppress the time-dependent change in the release function when the coated bioactive particles are stored for a long period of time. Further, in the present invention, the concentration is 10
The content is more preferably ppm or less, further preferably 5 ppm or less, and particularly preferably 1 ppm or less.

Further, in the case of producing a coated bioactive granular material having a time-release type sustained-release function, the concentration is 10 pp.
m or less, more preferably 1 pp
m or less. More preferably, it is below the detection limit.
The concentration of the volatile substance contained in these coated bioactive particles can be measured by a known analysis method such as gas chromatography (for example, ECD) by extracting with a solvent such as benzene or normal hexane.

[0063]

EXAMPLES The present invention will be described below with reference to examples.
The invention should not be limited by these examples. In addition, "%" in the following examples is "% by weight" unless otherwise specified.

1. Coating Method of Coated Bioactive Granules The apparatus shown in FIG. 1 was used to produce coated granular fertilizers. Tower diameter 250 mm, height 2000 mm, air outlet diameter 50 m
The hot hot air flowed from the lower part to the upper part into the jet tower 1 having a shape of m and a cone angle of 60 degrees. The high-temperature hot air is blown from the blower 10, passes through the orifice flow meter 9, is heated to a high temperature by the heat exchanger 8, is introduced into the jet tower 1, and is discharged from the exhaust gas outlet 3 installed at the upper part of the jet tower 1. After discharging and collecting the solvent with a condenser, the gas was circulated for reuse. Inside the jet tower 1 in which the high-temperature hot air is circulated, granular urea having a particle diameter of 2.0 to 3.4 mm and a circularity coefficient of 0.8 as core material particles containing a bioactive substance,
10 kg from the inlet 2 installed on the side of the jet tower 1
It is charged and the granular urea 5 is jetted as shown in FIG. At this time, the flow rate and the hot air temperature were 4 m ³ / min for the flow rate (orifice flow meter 9) and the hot air temperature (hot air temperature T1).
Granular urea 5 is heated at 100 ° C ± 2 ° C and the particle temperature is 70
The coating was started after reaching ± 2 ° C (core material particle temperature T2). The flow rate was adjusted while measuring with an orifice flow meter.

On the other hand, polyethylene (low density polyethylene d = 0.9) was used as the coating material composition (parts by weight) in the dissolution tank 11.
18 [g / cm ³ ] (Density JIS K6760), MI = 22 [g / 10
min] (melt index JIS K6760), melting point 1
20 ° C.) 50, corn starch 4.9, talc (average particle size 10 μm) 45, iron stearate (reagent product) 0.1 and toluene as a solvent, and mix and stir at 100 ° C. ± 2 ° C. Dissolves the resin by 1.5% by weight
As a result, a mixed solution 12 of uniform coating material was obtained. The dissolution tank 11 was constantly stirred until the coating was completed. The mixed solution 12
Is transported at a flow rate of 0.1 kg / min to a spray nozzle 4 which is an opening 0.8 mm full-con type one-fluid nozzle installed in the lower part of the jet tower 1 by a pump 6, and is sprayed on the flowing granular fertilizer 5. And then sprayed. At this time, the temperature of the mixed solution 12 was maintained at 100 ° C ± 2 ° C. The dissolution tank 11 and the pipe from the dissolution tank 11 to the spray nozzle 4 were made into a double structure, and the mixed dissolution liquid 12 was transported through a steam while heating so as not to be lower than 80 ° C. The blowing process starts when the powder temperature T2 of the flowing granular fertilizer 5 reaches 70 ° C., and the core material particles are measured while measuring the hot air temperature of T1, the core material particle temperature of T2, and the exhaust temperature of T3. The temperature T2 was maintained at 70 ° C ± 2 ° C. The coating was sprayed for a predetermined time until the coating became 8.5% by weight of the coated granular fertilizer. Then, the blower 10 was stopped, and the coated granular fertilizer 5 was discharged from the outlet 7 at the bottom of the jet tower 1 to obtain a coated granular fertilizer. Further, the coverage is a ratio of the weight (A) of the coating to the coated bioactive particles, where the sum of the weight (A) of the coated bioactive particles and the weight (B) of the coating is 100% by weight. B x 100 / (A +
B)].

2. Aeration step 500g of the coated granular urea fertilizer obtained in "1. Method of coating coated bioactive particulates" is put into the aeration device of FIG.
Aeration was carried out by introducing air into the apparatus through the hot air introduction tube under the conditions shown in Table 2 and ventilating. As the test gas, air having a volatile substance (trichloroethylene, perchlorethylene, toluene) concentration of less than 1 ppm was used. Specifically, the exhaust gas is continuously discharged from the upper opening, treated with a solvent recovery device, and then reused as a gas for aeration treatment.

3. Production of coated bioactive granules (Comparative Example 1)
˜2, Examples 1 to 9) The coated bioactive granules produced according to “1. Coating method of coated bioactive granules” are used in “2. Aeration was performed according to the method of "aeration step".

4. Method for measuring volatile substances Using benzene as an extracting solvent, 0.5 g of coated granular urea fertilizer was immersed in 50 ml of the extracting solvent at room temperature for 1 week to extract the volatile substances. An analytical sample was prepared. The analysis sample was analyzed for volatile substances by gas chromatography (detector: ECD (extraction solvent: benzene), FID (extraction solvent: normal hexane)) to obtain the concentration of volatile substances. The results are shown in Table 1.

5. Method of measuring dissolution rate 2 g of 10 g of coated granular urea fertilizer was immersed in 200 ml of water.
The mixture was allowed to stand at 5 ° C., and after 3 days, it was divided into coated granular urea fertilizer and water, and urea eluted in water was obtained by quantitative analysis and listed in Table 1.

[0070]

[Table 1]

As is clear from the results shown in Table 1, Comparative Example 1
Contains a high concentration of volatile substances, and Comparative Example 2 removes the volatile substances but impairs the elution control, whereas Examples 1 to 11 are volatile without impairing the elution control. The substance concentration can be reduced sufficiently.

[0072]

By using the production method of the present invention, it is possible to sufficiently reduce the concentration of volatile substances without impairing the elution control of the obtained coated bioactive particles.

[Brief description of drawings]

Figure 1: Flow sheet diagram of spouted bed

[Fig. 2] Venting device diagram

[Explanation of symbols]

1. Spout tower 2. Granular material input port 3. Exhaust gas outlet 4. spray nozzle 5. Core material particles 6. pump 7. Outlet 8. Heat exchanger 9. Orifice flow meter 10. Blower 11. Melting tank 12. Mixed solution of coating materials 13. condenser 14. Solvent recovery liquid 15. Dust remover T1. Hot air thermometer T2. Granule thermometer T3. Exhaust thermometer SL. steam

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C05C 9/00 C05C 9/00 A C05G 5/00 C05G 5/00 Z F term (reference) 4G004 BA01 BA02 4H011 AA01 AA03 AB01 AB03 AC01 AC04 AE01 BB21 BC01 BC06 BC18 BC19 BC20 BC22 DA02 DA04 DC07 DC08 DC10 DH02 DH03 DH04 DH05 DH07 DH10 DH13 4H061 AA02 BB15 DD18 EE03 EE36 FF08 GG15 GG18LL16 LL15 GG19 LL05 HGG19 LL05 HGG19 LL05 HGGLL

Claims (11)

[Claims] 1. A volatile substance present in a coated bioactive granular material obtained by spraying and drying a coating material on the surface of core material particles containing a bioactive substance is removed by aeration with hot air. Claims: 1. A method for producing a volatile-free coated bioactive granulate, characterized in that hot air is vented at an aeration rate below the minimum fluidization rate of the coated bioactive granules. Method for producing bioactive granules. 2. The method for producing a coated bioactive granular material from which volatile substances have been removed according to claim 1, wherein an aeration rate (air velocity) of hot air is 200 cm / sec or less. 3. The coated bioactive particles have an average particle size of 0.3.
The method for producing a coated bioactive particle from which volatile substances have been removed according to claim 1, which is a particle having a size of 10 mm. 4. The volatile substance according to claim 1, wherein the temperature of the hot air is less than (T-5) ° C. when the melting point of the thermoplastic resin in the coating material used is T ° C. A method for producing a removed coated bioactive particulate. 5. The method for producing a coated bioactive granular material from which volatile substances have been removed according to claim 1, wherein aeration time of hot air is 0.05 to 2 hours. 6. The method for producing a coated bioactive granular material from which volatile substances have been removed according to claim 1, wherein the coating method is a method of spraying a coating material solution. 7. The method for producing a coated bioactive granular material free from volatile substances according to claim 1, wherein the coating material is a thermoplastic resin. 8. The method for producing a coated bioactive granular material from which volatile substances have been removed according to claim 1, wherein the coating material is an olefin polymer. 9. The method for producing a coated bioactive granular material from which volatile substances have been removed according to claim 1, wherein the core material particles containing the bioactive substance are fertilizers. 10. The coated bioactive granular material has a specific gravity of 0.5 to 3.
A process for the preparation of volatile-depleted coated bioactive granules according to claim 1, which is a granulate with g / ml. 11. The method for producing a coated bioactive granular material free from volatile substances according to claim 9, wherein the fertilizer is urea.