JPH1025179A - Degradable type coated granular fertilizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a degradable type coated granular fertilizer, hardly causing a degradation of the coating film even if the coated particle fertilizer is exposed to a sun light and having an improved activities for controlling an elution by coating a surface of a granular fertilizer coated with a resin film degradable by an irradiation of ultraviolet rays with a specific coating film. SOLUTION: This degradable coated granular fertilizer is obtained by coating a surface of a granular fertilizer coated with a resin film degradable by an irradiation of ultraviolet rays with a coating film containing a light screening agent and/or a light stabilizing agent and comprising a biodegradable and/or a water-soluble resin. Concretely, the coated granular fertilizer is obtained by coating the granular fertilizer with a resin selected from an olefin- carbon monoxide copolymer, an olefin-carbon monoxide-vinyl acetate copolymer, an olefin-vinyl ketone copolymer, a vinylidene chloride-vinyl ketone copolymer and a diene-based copolymer and degradable by the irradiation of the ultraviolet rays. The objective degradable coated granular fertilizer is obtained by charging the coated granular fertilizer from a fertilizer- charging opening 2 into a jetting tower 1, fluidizing the coated granular fertilizer by a jetting nitrogen gas introduced from a blower 10 through an orifice flowmeter P and a heat exchanger 8, spraying a coating liquid containing the light screening agent and/or the light stabilizing agent and comprising the biodegradable and/or the water-soluble resin from a liquid tank 11 through a single-fluid nozzle 4 to coat the surface of the coated granular fertilizer with the coating liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a fertilizer. More specifically, the present invention relates to a coated granular fertilizer coated with a coating that degrades and disintegrates when irradiated with ultraviolet light.

[0002]

2. Description of the Related Art In order to match the elution of fertilizer components of granular fertilizers applied to soil with the requirements associated with the growth of crops, or to prevent moisture absorption or solidification in the distribution process of granular fertilizers. Therefore, various studies have been made. One of the methods is to coat the surface of the granular fertilizer with a polymer. For this coating, either a thermosetting resin or a thermoplastic resin is used. Examples of the method using a thermosetting resin include a styrenated alkyd resin and a phenol resin (UK Patent No. 594555), a fatty oil-modified alkyd resin, a fatty oil dicyclopentadiene copolymer, and a diisocyanate-modified fatty oil copolymer (Japanese Patent Publication No. Sho. 40-28927
No.) or phenolic resin (JP-B-44-2845)
No. 7) is shown. As a method using a thermoplastic resin, for example, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyacrylonitrile, polyethylene, and polyfluorinated alkane, or a copolymer comprising two or more of these structural unit monomers (UK patent) No. 81582
No. 9), a vinyl acetate emulsion polymerization solution (JP-B-37-1583).
No. 2). As a problem when using a high-molecular polymer, especially a thermoplastic resin solution or an emulsion polymerization solution thereof as a coating material, Japanese Patent Publication No. 42-13681 discloses that a granular material is coated with a liquid or spinnable resin. Then, only a few percent of the resin is coated due to the spinnability of the resin, and the particles stick together and form blocks, and it is difficult to coat uniformly and thickly without individual particles. It is shown.

[0003] JP-A-50-99858 and JP-A-51-99858
JP-A-756574 and JP-A-53-88265 disclose a method in which the coating can be efficiently performed in one step without blocking in the coating step by selecting the properties of the resin solution and the drying conditions. Japanese Patent Application Laid-Open No. 50-93858 discloses that, when a granular fertilizer is coated with a coating material containing polyolefin as a main component, a solution of the coating material is sprayed on the granular fertilizer, and the coated granular fertilizer is dried at the same time as a high-speed hot air stream. A method of coating is shown. The features of this technology are:
The point is that the film can be uniformly coated with an extremely thin film, and the dissolution rate can be adjusted by dispersing a surfactant as a dissolution controlling agent in the film. JP-A-51-75874 discloses that a polyvinylidene chloride-based resin and an ethylene-vinyl acetate copolymer having a vinyl acetate portion of 5% by weight or less can uniformly coat a granular fertilizer as an extremely thin film simultaneously with a polyolefin resin. Is disclosed. Japanese Patent Publication No. 60-3707
No. 4 discloses that coating with a polyolefin-based resin, an ethylene-vinyl acetate copolymer and a surfactant can provide highly stable elution control. As described above, the granular fertilizer coated with the resin coating has developed its function. However, the main component of these coatings is a hardly decomposable resin, and there is a problem that the capsule after elution of the fertilizer remains in the soil for a long period of time. As a solution to this problem,
No. 516 discloses a photodegradable coating containing an ethylene / carbon monoxide copolymer as an active ingredient.
No. 23515 discloses a photo-degradable coating containing an ethylene / vinyl acetate / carbon monoxide copolymer as an active ingredient. The disclosure of these techniques has substantially solved the problem of capsule remaining after elution.

On the other hand, looking at the current state of farming and fertilizing work, most of the farmers in Japan are part-time farmers, and it is rare to perform fertilization and tillage immediately before sowing as in the past. In general, a work system in which fertilizer is first applied to a soil surface several weeks before sowing on a holiday, tilling after a certain period of time, and seeding immediately after tilling or after a certain period of time is performed. In such a working system, the fertilizer is left on the soil surface for a certain period of time and is exposed to sunlight. There was no problem with conventional chemical fertilizers or fertilizers with hard-to-degrade coatings.However, in the case of photolytic decay-type fertilizers, depending on the coating composition, the coating deteriorates during the standing period and is added during tilling after the standing. In some cases, the coating was damaged by the impact and the dissolution function was impaired. As a countermeasure, a method of dispersing a light-blocking agent or a light stabilizer in the above-mentioned film has been proposed, but this method certainly suppresses the collapse (deterioration) of the film before the onset of fertilizer effect, but stabilizes the film. The action continues even after the end of the elution, resulting in a significant impairment of the photodisintegration function.

[0005]

SUMMARY OF THE INVENTION The present inventors have conducted intensive studies in view of the above-mentioned problems relating to a coated fertilizer having a photo-degradable coating, and as a result, surprisingly, they have found that a resin which can be destroyed by irradiation with ultraviolet rays is effective. A coated granular fertilizer in which the surface of a granular fertilizer is coated with a film as a component, wherein the surface of the coated granular fertilizer is effectively treated with a light blocking agent and / or a light stabilizer, and a biodegradable resin and / or a water-soluble resin. The present invention was completed by finding an extremely excellent effect on a coated granular fertilizer further coated with a coating as a component. As is apparent from the above description, an object of the present invention is to provide a coated fertilizer having a photo-degradable coating, in which the coating having a dissolution control function is degraded (degraded) even when exposed to sunlight for a certain period of time before the onset of fertilizer effect. An object of the present invention is to provide a coated granular fertilizer that does not undergo dissolution and undergoes disintegration (deterioration) after completion of dissolution.

[0006]

Means for Solving the Problems The present invention provides the following:
6 to 6.

(1) In a coated granular fertilizer coated on the surface of a granular fertilizer with a coating containing a resin which is disintegrated by irradiation with ultraviolet rays as an active ingredient, the surface of the coated granular fertilizer is a light blocking agent and / or a light stabilizer. Characterized by being coated with a coating consisting of at least one selected from a biodegradable resin and / or a water-soluble resin.

(2) The resin which is disintegrated by irradiation with ultraviolet rays is an olefin / carbon monoxide copolymer,
2. The disintegration type coated granular fertilizer according to the above item 1, which is at least one selected from carbon monoxide / vinyl acetate copolymer, olefin / vinyl ketone copolymer, vinylidene chloride / vinyl ketone copolymer, and diene polymer. .

[0009] (3) The disintegration type coated granular fertilizer according to the above (1), wherein the resin which is disintegrated by irradiation with ultraviolet rays is a vinyl resin containing a transition metal, a transition metal compound, and a transition metal complex.

(4) The collapsible coated granular fertilizer according to the above (1), wherein the light blocking agent is a pigment.

(5) The pigment is carbon black, lead chromate, zinc white, titanium white, iron oxide, Watchung®
ed, Pyragolone, chrome yellow, cadmium yellow, phthalocyanine blue, indanthrene blue, phthalocyanine green, chromium oxide green, chromium molybdate orange, benzylidene orange, chromium orange
Item 8. The coated granular fertilizer according to item 8.

(6) The disintegration-type coated granular fertilizer according to (1), wherein the light stabilizer is at least one selected from an ultraviolet absorber, a radical scavenger, and a quencher.

Hereinafter, the configuration of the present invention will be described in detail. The resin which is degraded by irradiation with ultraviolet light according to the present invention, by the absorption of light energy by the resin, cutting of the main chain or cross-linking inside the chain occurs, so-called cracks, hardening,
It refers to a resin that undergoes an aging phenomenon called collapse in a very short time. The resin which is disintegrated by irradiation with ultraviolet rays is not particularly limited, but an olefin / carbon monoxide copolymer, an olefin / carbon monoxide / vinyl acetate copolymer, an olefin / vinyl ketone copolymer, a vinylidene chloride / vinyl ketone Copolymers, diene polymers and the like,
Further, a polypropylene containing no stabilizer, an aliphatic polyester, and the like can also be cited as one of the resin materials which are easily disintegrated by irradiation with ultraviolet rays. Examples of the olefin monomer of the olefin / carbon monoxide copolymer, the olefin / carbon monoxide / vinyl acetate copolymer, and the olefin / vinyl ketone copolymer include ethylene, propylene, and butene. As the vinyl ketone, methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and methyl isopropyl vinyl ketone are preferable. Ethylene methyl vinyl ketone, ethylene methyl isopropyl vinyl ketone, and ethylene ethyl ketone are particularly effective vinyl ketones. Examples of the diene-based polymer include homopolymers of butadiene and isoprene, and copolymers containing these, such as butadiene-styrene copolymer, butadiene-acrylonitrile copolymer, and isoprene-styrene copolymer.

Further, in the present invention, the resin which is disintegrated by irradiation with ultraviolet rays may be a vinyl resin containing a transition metal, a transition metal compound or a transition metal complex. As transition metals and transition metal compounds, Cu, Ag, Zn, Cd,
Fine powder metal such as Cr, Mo, Mn, Fe, Co, Ni, metal oxide, metal halide, inorganic acid metal salt,
Organic acid metal salts and the like can be mentioned. The transition metal oxide is, for example, an inorganic pigment such as titania (particularly anatase type), chrome green oxide, or cobalt blue, and the transition metal halide is, for example, NiCl ₂ , NiBr ₂ , Co
Br ₃ , FeCl ₂ , FeCl ₃ , CrCl ₂ , CrC
l ₄ , MnCl ₂ , MnCl ₃ , TiCl ₄ , CuC
l, ZnCl ₂ etc., and inorganic acid transition metal salts include, for example, sulfuric acid, sulfurous acid, nitric acid, nitrous acid, carbonic acid, phosphoric acid, phosphorous acid and Zn, Cd, Cr, Mo, Mn, Fe, C
o, Ni, Cu and the like are finely pulverized salts, and the organic acid transition metal salt is, for example, an organic acid having 1 to 22 carbon atoms, that is, a transition metal of a saturated, unsaturated, aliphatic carboxylic acid or aromatic carboxylic acid. It is a salt, but is not limited to these. Examples of the transition metal complex include those comprising the above transition metal and a complexing agent such as acetonylacetonate, acetylacetonate, and dialkyldithiocarbamate.

As the vinyl resin, polyolefin, polyvinyl acetate, polyvinyl chloride, polyvinylidene chloride, polyacrylate, polymethyl methacrylate, polyacrylonitrile, polyvinyl ether, copolymers containing these, and mixtures of these polymers can be used. I can do it.

The above-mentioned polyolefins include polyethylene, polypropylene, polybutene, polystyrene and the like.
Propylene copolymer, butene / ethylene copolymer, butene / propylene copolymer, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / acrylic acid ester copolymer, ethylene / methacrylic acid copolymer Polymer, ethylene / methacrylate copolymer, ethylene / carbon monoxide copolymer, ethylene / carbon monoxide /
Examples thereof include vinyl acetate copolymer. Further, examples of the copolymer containing polyvinyl chloride include a vinyl chloride / vinyl acetate copolymer and a vinyl chloride / vinylidene chloride copolymer.

The present invention provides a function in which a coating having an elution control function is not subjected to collapse (deterioration) even when exposed to sunlight for a certain period of time before the onset of fertilizer effect. However, after the onset of fertilizer effect (after the end of elution), it is necessary that the capsule (coating) which has been emptied and undergoes photolysis gradually disappears. Therefore, the inventors of the present invention apply the above-mentioned resin which is disintegrated by irradiation with ultraviolet rays to an active ingredient so that the resin is not disintegrated (deteriorated) before use and disintegrated (deteriorated) after use. Further, the surface of the coated granular fertilizer was coated with a film containing a light-blocking agent and / or a light stabilizer and a biodegradable resin and / or a water-soluble resin as active ingredients.

The purpose of using a biodegradable resin and / or a water-soluble resin in the present invention is that point. After mixing with the soil, the protective film is formed of a resin which is dissolved by microbial decomposition or irrigation or rainwater. And

As an example of the light blocking agent used in the present invention, a pigment can be mentioned. Pigments include carbon black, lead chromate, zinc white, titanium white, iron oxide, Watc
hun Red, Pyragolone, chrome yellow,
Cadmium yellow, phthalocyanine blue, indanthrene blue,
Phthalocyanine green, chromium oxide green, chromium molybdate orange, benzylidene orange, chrome orange and the like can be given, but not limited thereto. The most effective of these pigments is carbon black, and the hue next to carbon black is dark brown, followed by the hue including white cream color and titanium white. When carbon black is used, fine particle carbon, that is, channel carbon is particularly suitable. Further, among the channel carbons, fine-particle HCC carbon black is more preferable. The addition amount of these pigments depends on the type of pigment, but 2 to 5% is sufficient. The effect increases up to this range,
No further increase in the effect can be expected even if added more.

The light stabilizer used in the present invention is an ultraviolet absorber,
Any of a radical scavenger and a quencher can be used. Benzotriazole based UV absorbers,
There are benzophenone type, salicylate type, cyanoacrylate type, etc., hindered amine type as radical scavenger, and nickel complex type as quencher. These light stabilizers have a low molecular weight, and have the disadvantage that they bleed (leach) out of the resin during storage and the effect is not long lasting. In addition, depending on its polarity, it may be transferred to a resin layer which is disintegrated by irradiation with ultraviolet rays, and the disintegration of the capsule after elution may be reduced.Therefore, the present inventors use inorganic pigments, especially carbon. We recommend using black.

The biodegradable resin used in the present invention is not particularly limited as long as it is a polymer having a function of being decomposed by assimilation of microorganisms in soil. Polymers having various structures are known as resins exhibiting biodegradability. Most of them are polymers having a bond (easily degradable bond) such as ester bond, orthoester bond, acetal bond, ketal bond, acid anhydride bond, carbonate bond, etc., which are easily hydrolyzed or enzymatically decomposed in the molecular structure. . Examples of the biodegradable resin include polyglycolic acid, polylactic acid, poly-β-propiolactone, poly-γ-butyrolactone,
Poly-δ-valerolactone, polylactones such as poly-ε-caprolactone, poly-3-hydroxybutyrate, polyhydroxyalkanoates such as poly-3-hydroxybililate, chitin, chitosan, poly-p-dioxanone, Examples thereof include trimellilen carbonate polymer, polymalic acid, acid anhydride polymer, polyalkylcyanoacrylate, polysaccharides such as amylose, starch, and dextran, and copolymers thereof. In addition, polyglycolic acid / polyalkylene block copolymers (Japanese Unexamined Patent Application Publication No.
-100130), urethane polymer (Japanese Unexamined Patent Publication No. 63-63)
278924), β-malolactone polymer (JP-A-5
No. 6-26929), polyether glycol polymers (Japanese Patent Application Laid-Open No. 1-195862), polypeptides (Publication No. 63-502039), polyiminocarbonates (Macromolecules, Vol. 22, No. 5, p. 2).
029), polydepsipeptide (Japanese Patent Publication No. 1-2157)
No. 4), polyethylene glycol succinate (JP-A-50-47492), lignin analogous polymer (Japanese Patent Publication No.
A wide variety of polymers are known. In addition to these, wax can also be used as a biodegradable polymer for the protective film of the present invention. The wax is, for example, a vegetable wax such as a wood wax, a bayberry wax, and an owery curie wax, an animal wax such as a beeswax, an insect wax, a whale wax, and a petroleum wax such as a paraffin wax and a microcrystalline wax.

The water-soluble resin indispensable for the protective layer is not particularly limited as long as it has a function of dissolving in water or in a high moisture environment such as in soil.
Any of plant-based and animal-based natural water-soluble polymers, semi-synthetic water-soluble polymers, and synthetic water-soluble polymers may be used. As the water-soluble polymer used in the present invention, for example, soluble starch,
Starch-based natural products such as carboxymethyl starch and dextrin, natural substances such as sodium alginate, gum arabic, gelatin, casein, cellulose derivatives such as methylcellulose, polyvinyl alcohol, polyvinyl methyl ether, polyvinyl pyrrolidone, and vinyl pyrrolidone-vinyl acetate Examples include, but are not limited to, polymers, polyacrylamide, polyethylene glycol, polyethylene oxide, and polymers of acrylic acid, methacrylic acid or their esters or salts, or copolymers thereof. In the present invention, one or more selected from the above-mentioned biodegradable resins and water-soluble resins may be used. General-purpose resins such as polyethylene and polypropylene may be used as long as functions such as decomposability and water solubility are not impaired.

In the present invention, additives such as a filler and a surfactant can be used as long as the physical properties of the film and the dissolution control function are not impaired. The powder used as the filler used in the present invention is a poorly water-soluble or water-insoluble powder, and the particle size thereof is preferably half the thickness of the coating, preferably １ ／ or less. These fillers are uniformly dispersed in the coating, but those having poor dispersibility require a surface treatment with silicon or the like or a dispersibility improving treatment such as easy dispersion with a surfactant or the like. Preferred materials for these fillers include talc, calcium carbonate, clay, diatomaceous earth, silica and salts thereof. When these are used, the coating strength tends to decrease as the amount of use increases, regardless of which powder is used.

The surfactant which can be used in the present invention may be any of cationic, anionic, amphoteric and nonionic surfactants. Balance is important. If the hydrophilicity is too strong, it will not uniformly disperse in the coating but will aggregate and cause the formation of coating defects. Those with strong lipophilicity have no effect on the coating, but tend to have a slightly inferior dissolution promoting effect. HL of these surfactants
B is less than or equal to 15, preferably in the range of 11 to 13.

The present invention is applicable to granules containing any fertilizer component. For example, water-soluble fertilizers such as ammonium sulfate, salt ammonium, ammonium nitrate, urea, potassium chloride, nitrate potassium, sodium nitrate, ammonium phosphate, potassium phosphate, lime phosphate, and the like, and chelated iron, iron oxide, iron chloride, boric acid, borax, and sulfuric acid. It is particularly effective for fertilizers containing one or more components of water-soluble trace elements such as manganese, manganese chloride, zinc sulfate, copper sulfate, sodium molybdate, and ammonium molybdate. OMUP (clotilidene diurea), IBD
When applied to poorly water-soluble fertilizers such as U (isobutylidene diurea) and oxamide, the effective period of these fertilizers can be extended.

Known methods can be applied as a method for producing the coating of the present invention. For example, the jet coating method described above may be used.Also, similarly to the jet coating method, after dissolving in an organic solvent or an inorganic solvent, the solution is added to the coated fertilizer moving with a rotating pan, a rotating drum, etc., and hot air is blown. A method of forming and growing a film by drying at the same time may be used. However, when a pigment such as carbon black is used, there is a difference in the disintegration protection time depending on the quality of the dispersed state, and the pigment is coated with sufficient care so as not to aggregate in the biodegradable and / or water-soluble resin. Should.

[0027]

According to the present invention, there is provided a coated granular fertilizer which is a coating containing a resin which is disintegrated by irradiation with ultraviolet rays as an active ingredient and which covers the surface of the granular fertilizer. And / or a light stabilizer and a biodegradable resin and / or
Alternatively, it is a film containing a water-soluble resin as an active ingredient. According to the coating composition of the present invention, in a coated fertilizer having a photo-degradable coating, the coating having a dissolution control function does not undergo disintegration (deterioration) even when exposed to sunlight for a certain period of time before the onset of fertilization effect, and after the dissolution is completed. A coated granular fertilizer that undergoes rapid disintegration (deterioration) can be obtained.

[0028]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited by the description of the examples. 1. Production Example 1 of the Fertilizer of the Present Invention FIG. 1 shows a jet encapsulation apparatus used in the production example. 1 is a jet tower having a tower diameter of 250 mm, a height of 2000 mm,
It has a fertilizer inlet 2 and an exhaust gas outlet 3 with a nitrogen gas outlet diameter of 50 mm and a cone angle of 50 degrees. The nitrogen gas for the jet is sent from the blower 10 and reaches the jet tower through the orifice flow meter 9 and the heat exchanger 8. The flow rate is controlled by the flow meter and the temperature is controlled by the heat exchanger. Is derived.
The granular fertilizer used for the encapsulation process is injected from the fertilizer input port 2 while passing a predetermined hot air (N ₂ gas) to form a jet. Hot air temperature T _1, the particle temperature during encapsulation T _2, the exhaust gas temperature is detected by thermometers T _a. T ₂
When the temperature reaches a predetermined temperature, the encapsulating liquid is sprayed through the one-fluid nozzle 4 toward the blasting particles. The coating liquid is stirred in the liquid tank 11 and, in the case of using powder, is stirred so that the powder is uniformly dispersed in the coating liquid. When the predetermined coverage is reached, the blower is stopped and the coated fertilizer is discharged from the outlet 7. In this production example, a sample was prototyped while maintaining the following basic conditions. Table 1 shows the coating composition.

One-fluid nozzle: 0.8 mm opening, full-con type Hot air volume: 4 m ³ / min Hot air temperature: 80 ± 2 ° C. Fertilizer type: granular urea of 6 to 7 mesh Fertilizer input amount: 10 kg Test solvent: toluene Coating solution concentration : Solid content 5.0% by weight Coating liquid supply amount: 0.25 kg / min * The coating liquid is sent from the pump 5 and reaches the nozzle.
Heat with steam so that the temperature does not drop below ℃. Encapsulation rate (to fertilizer): 10% * Coating is performed while maintaining the above conditions until a predetermined coating rate is reached.

[0030]

[Table 1]

Note. All units of coating composition are parts by weight. * 1: Ethylene / vinyl ketone copolymer, carbonyl content: 3.5 wt% * 2: Talc, average particle size: 10 μm * 3: Ethylene / carbon monoxide copolymer, CO = 0.95
wt%, MI = 0.75 * 4: Low density polyethylene, MI = 20, d = 0.92
2 * 5: iron diisononyl dithiocarbamate, 2.5 × 1
Polyethylene containing ^0-4 mol / 100 g * 6: Styrene / isoprene block copolymer, styrene / isoprene = 14/86, MI = 9, d = 0.92 * 7: Ferric stearate, reagent product * 8 : Average particle size 15 μm * 9: poly-3-hydroxy-3-methylpropionic acid, M _w = 750,000 * 10: carbon black, average particle size 65 μm * 11: poly-L-2-hydroxy-2 -Methyl acetic acid, _MW = 13,000 * 12: carbon black, average particle size 15 μm * 13: ε-polycaprolactone, M _W = 60,000 * 14: mica-like iron oxide, average particle size 40 μm * 15: polyvinyl Alcohol, degree of polymerization = 1,000,
Saponification degree = 86.5 mol% * 16: 2-hydroxy-4-methoxybenzophenone

2. Production Example 2 of Fertilizer of the Present Invention FIG. 2 shows a coated granular device used in Production Example 2. In the preparation of the coating solution, water and the coating material are put into a dissolving tank equipped with a stirrer, and the solvent is heated (with a boiling point of 5 to 10 ° C. or less as a guide), stirred and dissolved to obtain a resin solution having a solid content of 1% by weight. This solution is constantly stirred even after dissolution, and maintains a uniform dispersion state even when a filler is contained. To coat the fertilizer, the granular fertilizer is put into a rotating pan 4 and rolled. Hot air is blown into the fertilizer particles and the coating liquid is added from a spray nozzle 5 through a liquid tank 1, a pipe 2 and a pump 3 through a spray nozzle 5. Then, the solvent is evaporated to form a coating up to a predetermined coating rate to obtain a coated granular fertilizer. A sugar coating machine having a diameter of 30 cm is used as the rotating pan 4, and granular urea of 6 to 7 mesh is put in the rotating pan 4 and rotated at 30 rpm, and 200 m ³ / hr of 100 ± 2 ° C. (outlet temperature ) Is blown from about 20 cm from the particle rolling surface. After the coating liquid is dissolved and dispersed in the dissolution tank 1, it is maintained at about 50 ° C. while continuing stirring, and the coating liquid is sent to the spray nozzle 5 attached to the sugar-coating machine by the pump 3, and is atomized with compressed air. Rolling particles at a feed rate of 2 L / hr and a particle temperature of 50
It was added continuously so that it could be operated in the range of ~ 55 ° C, and the coating operation was performed until a predetermined coating rate was reached.

3. Deterioration promotion test of prototype sample "Soil leaving treatment" Paddy soil (Tamaki soil, Minamata city, Kumamoto prefecture) was air-dried and sieved with a 10 mesh sieve.
To 50 g, 60% of the maximum volume of water and a sample produced in the production example were put, mixed, put into a 500 ml polybin, and allowed to stand at 25 ° C. for 3 months. After the standing, the entire amount of the soil including the trial sample was transferred onto a 10 mesh sieve, and the trial sample and the soil were separated in water. "Outdoor exposure treatment" Length 15cm, width 15cm, depth 15c
m, place a 12-mesh pass of dried sand to a depth of 10 cm into a square vinyl chloride resin box, and arrange the above-mentioned soil-treated and non-soil-treated samples on the surface of the box to prevent rainwater from entering. 2m thick
m for 2 months (April 15 to June 15, 1-1 Noguchi-cho, Minamata City, Kumamoto Prefecture, unshaded vacant land at the Chisso Corporation Minamata Works). 5 g of each of the prototype samples subjected to the outdoor exposure treatment was taken, and a pinhole was made with a needle one by one, and the sample was allowed to stand still in water to completely elute the urea inside to form a hollow sample. Put the whole amount of this hollow sample into a V-type mixer
Stir and mix for 0 minutes. Thereafter, the mixture was passed through a 10-mesh sieve, and the percentage of the capsules that passed through was determined relative to the test capsules. For only the traces without leaving the prototype, or those without any traces, the above operation was not performed and the degree of collapse was set to 100%. Table 1 shows the results.

[Brief description of the drawings]

FIG. 1 is a process chart of a granular fertilizer used in Production Example 1 of the present invention.

[Explanation of symbols]

1: Jet column 2: Fertilizer turned inlet 3: gas outlet 4: A fluid nozzle 5: Pump 6: piping 7: Product outlet 8: heat exchanger 9: orifice flow meter 10: Blower 11: liquid tank T _1: Thermometer T ₂ : Thermometer T ₃ : Thermometer SL: Steam inlet

FIG. 2 is a process chart of a granular fertilizer used in Production Example 2 of the present invention.

[Explanation of symbols]

 1: liquid tank 2: piping 3: pump 4: rotating pan 5: spray nozzle 6: hot air blowing pipe

Claims (6)

[Claims] 1. A coated granular fertilizer coated on a surface of a granular fertilizer with a coating containing a resin which is disintegrated by irradiation with ultraviolet rays as an active ingredient, wherein the surface of the coated granular fertilizer is coated with a light blocking agent and / or a light stabilizer. A disintegrated coated granular fertilizer comprising an effective amount and coated with a coating comprising at least one selected from a biodegradable resin and / or a water-soluble resin. 2. A resin which is disintegrated by irradiation with ultraviolet rays is an olefin / carbon monoxide copolymer, an olefin / carbon monoxide / vinyl acetate copolymer, an olefin / vinyl ketone copolymer, a vinylidene chloride / vinyl ketone copolymer,
The disintegration-type coated granular fertilizer according to claim 1, which is at least one selected from diene polymers. 3. The disintegration-type coated granular fertilizer according to claim 1, wherein the resin which is disintegrated by irradiation with ultraviolet rays is a vinyl resin containing a transition metal, a transition metal compound, and a transition metal complex. 4. The disintegrable coated granular fertilizer according to claim 1, wherein the light blocking agent is a pigment. 5. The pigment is carbon black, lead chromate,
Zinc white, titanium white, iron oxide, Watchung Re
d, Pyragone, chrome yellow, cadmium yellow,
The disintegration-type coated granular fertilizer according to claim 4, which is at least one selected from phthalocyanine blue, indanthrene blue, phthalocyanine green, chromium oxide green, chromium molybdate orange, benzylidene orange, and chrome orange. 6. The disintegration-type coated granular fertilizer according to claim 1, wherein the light stabilizer is at least one selected from an ultraviolet absorber, a radical scavenger, and a quencher.