JPH09194280A - Coated granular fertilizer having degradable coating film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the fertilizer which is compatible for both dissolution control and sufficient strength of the oxidative-degradable coating film of each of granules of the fertilizer by coating the surface of each of granules of a granular fertilizer with a specific resin contg. a substance capable of promoting polymer oxidative degradation via a specific resin contg. a biodegradable polyester. SOLUTION: The production of this fertilizer comprises: coating the surface of each of granules of a granular fertilizer with a resin contg. as its effective components, at least one biodegradable polyester and at least one polymer selected from among polyolefins, olefin-other monomer copolymers, polyvinylidene chlorides and vinylidene chloride-other monomer copolymers; and then, coating the surface of the resulting coating layer with a resin contg. as its effective component(s), at least one polymer selected from among polyolefins and olefin-other monomer copolymers, each of which contains at least one substance capable of promoting polymer oxidative degradation. This fertilizer has coating film strength sufficiently endurable in each of production, storage, distribution and application stages.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a coated granular fertilizer. More specifically, it relates to a coated granular fertilizer coated with a degradable coating.

[0002]

2. Description of the Related Art So far, a coated granular fertilizer coated with an inorganic substance such as resin or sulfur has been developed and disclosed as a fertilizer whose elution rate can be controlled (Japanese Patent Publication No. 54/54).
-3104, JP59-30679, JP54
-817, etc.). Among these fertilizers, those coated with a thermoplastic resin have been successively developed with technologies for controlling the elution rate and the temperature dependence of elution (JP-A-55-9495).
No. JP-A-54-97260), its elution function has been enhanced. These coated granular fertilizers have enabled an epoch-making labor-saving fertilization method represented by, for example, one-time fertilization of paddy rice. However, although the coated granular fertilizer coated with these resins has an excellent elution control function, the problem that the coating film forming the capsule remains in the soil forever after the fertilizer of the contents is eluted. Had. As a solution to this problem, there has been disclosed a coated granular fertilizer obtained by coating a granular fertilizer with a biodegradable resin, which has been attracting attention in recent years from the viewpoint of environmental problems. In Japanese Patent Publication No. 23517/1990, a coated granular fertilizer coated with poly-3-hydroxy-3-alkylpropionic acid is disclosed, and in Japanese Patent Laid-Open No. 5-85873, a coated granular fertilizer coated with polycaprolactone is disclosed in Japanese Patent Laid-Open No. 7-61884. No. 6,058,097 discloses coated granular fertilizer coated with poly-2-hydroxy-2-alkylacetic acid. All of these biodegradable resins are hydrophilic (polar)
It is a strong polyester, and due to its strong hydrophilicity, the bond is cleaved by a hydrolase produced by a microorganism and is decomposed and assimilated. The fact that the hydrophilicity (polarity) is strong means that the permeation of water vapor and water is large, and most of the coated granular fertilizers coated with these biodegradable resins have extremely fast elution. In addition, some substances take about 50 days to complete elution in aseptic water because they undergo a decomposing action from the time of application to soil, while some elution ends in about one week in soil. It was
To solve this problem, Japanese Patent Publication No. 23517/1990 and Japanese Patent Application Laid-Open No. 7-61884 disclose a technique in which a polyolefin resin such as polyethylene having a low water vapor permeability is blended to adjust the elution rate and the decomposition rate. Has been done.
This technology has dramatically expanded the range in which the elution rate and coating decomposition rate can be adjusted.

[0003]

However, a blend of a thermoplastic resin such as these polyolefin resins and a biodegradable polyester cannot obtain sufficient compatibility due to the difference in polarities of each other, and thus a blend of a single material cannot be obtained. It had a drawback that the film strength was extremely reduced compared to the film. In general,
When the fertilizer is actually manufactured, stored, distributed and used, the coating is subjected to considerable stress such as friction and impact. Especially in the field and paddy fields, automatic spraying machines have become popular in recent years due to the trend of labor saving. In general, an automatic spraying machine collides compressed air or fertilizer blown out by rotary blades with baffles with different angles to change the direction of scattering and uniformly disperse them in fields or paddy fields. Friction between machines and fertilizer particles when blown out, and collision with baffles cause cracks and scratches on the coating of coated fertilizer. When the coating has cracks or other flaws, it elutes from the flaws and elutes considerably faster than the originally designed elution period. In addition, since the manner of scratching differs depending on the situation, elution after scratching cannot be predicted at all. As described above, the characteristics of the coated granular fertilizer are proper elution control, and damage such as cracks and abrasions is a fatal obstacle for the coated granular fertilizer. In order to solve the problems of these biodegradable resin coatings, the present inventors have earnestly studied a coating composition that achieves both dissolution control of the biodegradable coating and coating strength. And finally, one or more polyesters having biodegradability on the surface of the granular fertilizer, polyolefin or a copolymer of olefin and other polymerized units, or polyvinylidene chloride or vinylidene chloride and other polymerized units. Polyolefins and their copolymers and polyvinylidene chloride and their copolymers, which are coated with a resin coating containing any one or more of the combined substances as an active ingredient and further contain a substance that accelerates the oxidative decomposition reaction of the polymer on the surface thereof. The present inventors have found that a coated granular fertilizer having a degradable coating characterized by being coated with a resin coating containing any one or more of the above as an active ingredient has extremely excellent coating properties and reached the present invention. As is clear from the above description, the object of the present invention is to provide a biodegradable polyester and a non-degradable polyolefin, or a copolymer of olefin and other polymerized units, polyvinylidene chloride, or vinylidene chloride and other A film that has a coating containing one or more selected from copolymers with polymerized units as an active ingredient, that can control elution for a long period of time, and can sufficiently withstand each scene of production, storage, distribution, and use. It is intended to provide a degradable film-coated granular fertilizer having strength.

[0004]

The present invention has the constitutions 1 to 12 described below. (1) One or more polyesters having biodegradability on the surface of granular fertilizer, and polyolefin, a copolymer of olefin and another polymerized unit, or polyvinylidene chloride or vinylidene chloride and another polymerized unit. Polyolefin coated with a resin coating containing one or more of the combined substances as an active ingredient and further containing one or more substances that accelerate the oxidative decomposition reaction of the polymer on the surface, or a copolymer of olefin and other polymerized units. A coated granular fertilizer having a degradable coating, characterized by being coated with a resin coating containing, as an active ingredient, one or more of a polymer, polyvinylidene chloride or a copolymer of vinylidene chloride and another polymerized unit. (2) Polyester having biodegradability is poly-3-hydroxy-3-alkylpropionic acid, poly-2-hydroxy-2-alkylacetic acid, polycaprolactone,
And the coated granular fertilizer according to item 1, which is an aliphatic polyester represented by the following general formula (1).

Embedded image (Here, R ¹ and R ² are each an alkylene group having 2 to 10 carbon atoms.) (3) In the above-mentioned item 2, wherein the alkyl group of poly-3-hydroxy-3-alkylpropionic acid is a methyl group or an ethyl group. The coated granular fertilizer described. (4) The coated granular fertilizer according to the above item 2, wherein the alkyl group of poly-2-hydroxy-2-alkylacetic acid is hydrogen, a methyl group or an ethyl group. (5) R of the aliphatic polyester represented by the general formula (1)
¹ is an alkylene group having 2 or / and 4 carbon atoms, and R ^{2 of the} aliphatic polyester represented by the general formula (1) is an alkylene group having 2 or / and 4 carbon atoms. Coated granular fertilizer. (6) Polyolefin or a copolymer of olefin and another polymer unit is polyethylene, polypropylene, ethylene / propylene copolymer, ethylene / vinyl acetate copolymer, ethylene / carbon monoxide copolymer, ethylene / vinyl acetate The coated granule according to the above item 1, which is one or more selected from carbon monoxide copolymer, ethylene / acrylate copolymer, ethylene / methacrylic acid copolymer, rubber-based resin, polystyrene, polymethylmethacrylate and the like. fertilizer. (7) The coated granular fertilizer according to item 1, wherein the polyvinylidene chloride or its copolymer is polyvinylidene chloride or a vinylidene chloride / vinyl chloride copolymer. (8) The substance that promotes the oxidative decomposition reaction is an unsaturated fatty acid having a -C = C-unsaturated bond, an unsaturated fatty acid ester,
8. The coated granular fertilizer according to any one of items 1 to 7, which is one or more kinds selected from fats and oils, diene polymers, transition metals, and transition metal compounds. (9) The coated granular fertilizer according to any one of items 1 to 8, wherein the substance that promotes the oxidative decomposition reaction is sublimable fine particles. (10) The coated granular fertilizer according to the above item 9, wherein the sublimable fine particle group is at least one selected from naphthalene, camphor, and sulfur. (11) The coated granular fertilizer according to any one of 1 to 10 above, which is formed by mixing a poorly water-soluble or water-insoluble organic or inorganic filler in the coating. (12) The inorganic filler is one or more selected from powders of talc, clay, diatomaceous earth, silica, calcium carbonate, zeolite, metal oxide or sulfur, and the organic filler is a sugar polymer and its derivative, or cloth. 12. The coated granular fertilizer according to the above item 11, which is one or more selected from powders of redendiurea, isobutylidene diurea and oxamide.

The structure of the present invention will be described in detail below. Biodegradable polyester essential to the present invention, the body produced by microorganisms in the soil, in-vivo hydrolase, or other hydrolase present in the soil, or the action such as hydrolysis in normal soil environment Indicates that the main chain is cleaved by. The decomposition rate is not particularly specified, but may be selected according to the purpose of use. However, when it is made into capsules of the shape used for current resin-coated fertilizers, it takes several months to 10 months in soil.
It is considered to be a practical range to select from capsules that disintegrate in a period of about a year and lose their capsule shape. In principle, any polyester having this function can be used, but the biodegradable polyester shown below is a particularly recommended resin material.

As the biodegradable polyester material preferred in the present invention, polyester is poly-3-hydroxy-3-alkylpropionic acid and its copolymer,
Examples thereof include poly-2-hydroxy-2-alkylacetic acid and its copolymer, polycaprolactone, and its aliphatic polyester copolymer represented by the general formula (1).

[0007]

Embedded image (Here, R ¹ and R ² are each an alkyl group having 2 to 10 carbon atoms)

The poly-3-hydroxy-3-alkylpropionic acid having any composition represented by the general formula (2) can be used in the present invention, and more preferable material is poly-3. -Hydroxy-3-methylpropionic acid, poly-3-hydroxy-3-ethylpropionic acid, and a copolymer of 3-hydroxy-3-methylpropionic acid and 3-hydroxy-3-ethylpropionic acid. You can However, the copolymer of 3-hydroxy-3-methylpropionic acid and 3-hydroxy-3-ethylpropionic acid can achieve the object of the present invention regardless of whether it is a random bond or a block bond. .

[0009]

Embedded image (Where R is an alkyl group)

The poly-2-hydroxy-2-alkylacetic acid can be used in the present invention regardless of the composition represented by the general formula (3), but a more preferable material is poly-2-hydroxy-2-alkylacetic acid. Hydroxyacetic acid, poly-2-hydroxy-2-methylacetic acid, poly-2-hydroxy-2-ethylacetic acid, and 2-hydroxyacetic acid and 2
-Hydroxy-2-methylacetic acid copolymers. However, the copolymer of 2-hydroxyacetic acid and 2-hydroxy-2-methylacetic acid can achieve the object of the present invention regardless of whether it is a random bond or a block bond. These poly-2-hydroxy-2-alkylacetic acid monomers have L-type, D-type, D, L-type and three types of optical isomers. It can be used in the invention.

[0011]

Embedded image (Where R is an alkyl group)

The polycaprolactone has a composition represented by the general formula (4), R is an alkylene group, and C _n ═C ₂
Any of C to C ₅ can be used in the present invention.

[0013]

[Chemical 6] (Where R is an alkyl group)

The aliphatic polyester copolymer represented by the general formula (1) is obtained by a condensation reaction between a glycol having an alkylene group having 2 to 10 carbon atoms and a dicarboxylic acid or its anhydride. R ¹ has 2 carbon atoms
A glycol having an alkylene group of 10 to 10, such as ethylene glycol, propylene glycol, trimethylene glycol, butanediol 1,3, butanediol 1,4, pentanediol 1,5, 3-methylpentanediol 1,5, hexane. These are diols 1,6, heptanediols 1,7, octanediols 1,8, nonanediols 1,9, decanediols 1,10, neopentyl glycol and mixtures thereof. R ² has ² carbon atoms
An aliphatic dicarboxylic acid having 10 to 10 alkylene groups or an anhydride thereof, such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid, dodecanoic acid, succinic anhydride , Glutaric anhydride and mixtures thereof. Of the above glycols and dicarboxylic acids, butanediol 1,
The combination of 4 and succinic acid or its anhydride, ethylene glycol and succinic acid or its anhydride, butanediol 1,4 and adipic acid, and ethylene glycol and adipic acid are low in cost of raw materials and can be said to be desirable combinations in the present invention. . By using the biodegradable resin, biodegradability in soil can be imparted to the film of the resin-coated granular fertilizer.

The polyolefin essential in the present invention, or
Copolymers of olefins with other polymerized units or polyvinylidene chloride or polynidene chloride with other polymerized units (hereinafter referred to as the resin) have a large polarity and a large water vapor permeability, that is, an elution rate. Because it is a material that is added to slow the elution rate of the fast biodegradable resin coating,
It is desirable to use one having a low polarity and a low water vapor permeability. Preferred polyolefins in the present invention or copolymers of olefins with other polymerized units include polyethylene, polypropylene, ethylene / propylene copolymers, ethylene / vinyl acetate copolymers, ethylene / carbon monoxide copolymers, ethylene. Vinyl acetate / carbon monoxide copolymer, ethylene / acrylate copolymer, ethylene / methacrylic acid copolymer, rubber resin, polystyrene,
Examples of the resin include polymethylmethacrylate, and any resin can be used as long as it has a low water vapor permeability.

Polyvinylidene chloride or a copolymer of vinylidene chloride and other polymerized units, which are preferred in the present invention, include polyvinylidene chloride, vinylidene chloride / vinyl chloride copolymer and the like. Any of these may be used as long as the resin has a low water vapor permeability like the polyolefin resin. What is effective as an oxidation promoter is an organic compound or polymer having a -C = C- unsaturated bond, and as the organic compound, an unsaturated fatty acid,
For example, oleic acid, linoleic acid, linolenic acid, arachidonic acid, erucic acid, palmitol acid, ricinoleic acid, eleostearic acid, etc., unsaturated fatty acid esters, such as oleic acid, linoleic acid, linolenic acid, arachidonic acid, erucic acid, palmitol. Acid, ricinoleic acid, methyl ester such as eleostearic acid, ethyl ester, propyl ester, isobutyl ester, etc., oils and fats, for example, linseed oil which is a drying oil, soybean oil, tung oil, sesame oil, semi-drying oil, rapeseed oil, Cottonseed oil, olive oil which is a non-drying oil, vegetable oil such as camellia oil, castor oil, and animal oil such as whale oil, beef tallow, fish oil, liver oil, and the like, and the polymer includes a diene polymer such as polybutadiene, polyisoprene, and styrene.
Butadiene copolymer, styrene-isoprene copolymer,
Examples thereof include, but are not limited to, acnylonitrile / butadiene copolymer.

Other oxidation promoters include transition metals and transition metal compounds, such as Cu, Ag, Zn and C.
Examples include fine powdery metals such as d, Cr, Mo, Mn, Fe, Co, and Ni, metal oxides, metal halides, inorganic acid metal salts, and organic acid metal salts. The transition metal oxide is, for example, an inorganic pigment such as titania (particularly anatase type), chrome oxide green, or cobalt blue. The transition metal halide is, for example, NiCl ₂ , NiBr ₂ ,
CoBr ₃ , FeCl ₂ , FeCl ₃ , CrCl ₂ , C
rCl ₄ , MnCl ₂ , MnCl ₃ , TiCl ₄ , Cu
Cl, ZnCl ₂ or the like, and the inorganic acid transition metal salt is, for example, sulfuric acid, sulfurous acid, nitric acid, nitrous acid, carbonic acid,
Phosphoric acid, phosphorous acid and Zn, Cd, Cr, Mo, Mn, Fe,
A finely divided salt of Co, Ni, Cu or the like, and an 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, aromatic carboxylic acid The salt is not limited to these.

Among substances having an unsaturated bond of -C = C-, an organic compound having a relatively low molecular weight such as a fatty acid, a fatty acid ester, and a fat and oil has a molecular weight of 0.5 to 40.
%, Preferably 1 to 30% is desirable. Below this range, the effect of promoting the oxidative decomposition of the polymer is insufficient, and above this range, the decomposition of the coating is further promoted, but the strength of the coating is reduced and the coating is not practical. Among substances having an unsaturated bond of -C = C-, those having a high molecular weight such as a diene polymer are added in an amount of 0.5 to 80%, preferably 1 to 70% by weight of the polymer composition. It is desirable to do. Similar to a low molecular weight organic compound, the oxidation promoting effect is insufficient below this range. In addition, polymers having unsaturated bonds, such as diene polymers, also have a function of accelerating the elution of the coating film. If the amount exceeds this range, the elution will be too fast to obtain a desired elution control.

The transition metal and the transition metal compound are contained in an amount of 0.05 to 20%, preferably 0.1 to 15% by weight of the polymer composition.
% Addition is desirable. Below this range, the effect of promoting oxidation is insufficient. Further, the addition amount is sufficient within the above range, and even if it is increased beyond the range, no improvement in the effect can be expected.
In addition, too much addition thereof is not suitable because it may cause deterioration of the coating due to overheating during manufacturing. For these oxidation promoters, a method of introducing a sensitive group such as -C = C- group which is susceptible to oxidative decomposition into a polymer film, and a method of introducing a substance having a catalytic action of oxidative decomposition such as a transition metal. In either case, the object of the present invention is achieved.

Further, in the present invention, sublimable fine particles can be mentioned as an oxidative decomposition promoting substance other than the above. The sublimable fine particles do not act directly on the polymer chain like the above-mentioned oxidative decomposition promoting substance, but the sublimable fine particles dispersed in the polymer composition are gradually sublimed after fertilization, resulting in In addition, fine voids are generated, the contact area with air is remarkably increased, and the partition walls of the oxidatively decomposable polymer composition are extremely thinned and are rapidly subjected to oxidative decomposition to easily collapse. Therefore,
The degree of sublimation of fine particles influences the period until the void is completed after fertilization. The oxidative decomposability of the polymer composition is proportional to the interface of voids (between voids and polymers), and the void interface is proportional to the ratio of sublimable fine particles and inversely proportional to the particle size. That is, the larger the proportion of addition and the smaller the particle diameter, the more the oxidative decomposition progresses, and it is planned to thoroughly study these combinations when designing the film.

The sublimable fine particles essential to the present invention are solid at room temperature and are insoluble or sparingly soluble in water and have a particle size of 0.
It has a particle size of 01 to 30 μm, preferably 0.1 to 20 μm, and is dispersed at 5 to 90%, preferably 10 to 80% of the coating weight. Preferred materials for the sublimable fine particles include naphthalene, camphor, and sulfur alone or in combination.

The method of slowing the elution rate of the biodegradable resin coating, which is one of the objects of the present invention, can be achieved by blending the polyester having a large water vapor permeability and the resin having a small water vapor permeability. This is because the water vapor permeability as a film is reduced by blending, and the polyesters are less likely to come into contact with microorganisms and hydrolases produced by microorganisms because the resins are mutually dispersed in the blend. It is thought to be due to this. However, if the resin is excessively mixed, the decomposability of the coating may be impaired.
It is desirable that the content be less than or equal to wt%, preferably less than or equal to 40 wt%. The elution rate should be set by selecting the resin within this range. However, blends of these resins having different polarities are generally poor in compatibility, and no matter how strong the coating strength of the resin alone before blending is, once blended, the strength is extremely lowered. However, in the present invention, the above-mentioned blend coating (this coating layer is described as a blend layer below) contains one or more substances that promote the oxidative decomposition reaction of the polymer, or a polyolefin or other polymerization. By further coating a coating containing a copolymer with a unit or polyvinylidene chloride or a copolymer of vinylidene chloride and another polymerization unit as an active ingredient (this coating layer is described as a protective layer below) It is possible to obtain a film strength that can withstand normal use. At this time, if the thickness of the protective film is made thicker, the strength is increased, but generally, it takes more time to decompose the oxidatively degradable film than the biodegradable film. In a situation where empty capsules after elution are likely to float in water and flow out, such as in paddy fields, prompt protective decomposition is required after elution, so it is desirable that the thickness of the protective film be as thin as possible. This film thickness should be arbitrarily set from the relationship between the required film strength and the decomposition rate.

When a further film strength is desired for the protective film having a limited film thickness, a resin material having high rubber elasticity such as ethylene / vinyl acetate copolymer may be selected and used. In the blend film of the polyester and the resin, the ratio of the blend is limited from the viewpoint of ensuring biodegradability as described above, and therefore there is a limit even if the elution rate is slowed by blending. When elution is controlled with a double coating,
Since the elution rate is almost determined by the characteristics of the layer with low water vapor permeability, when a slower elution rate is required, a resin with low water vapor permeability is used for the protective film, and the film with low water vapor permeability is used. The protective film may be formed of a composition. If a relatively high elution rate is required, a resin having a high water vapor permeability should be used. At this time, as a method of increasing the water vapor permeability of the protective film, a method of adding a sparingly water-soluble or water-insoluble filler to the protective film is recommended in addition to the selection of the resin. The sparingly water-soluble or water-insoluble filler may be used not only in the protective layer but also in the blend layer. The addition of the filler is not only useful in controlling elution as described above, but also advantageous in terms of cost if an inexpensive filler is used. However, the composition of the coating film should be determined in consideration of the fact that the addition of the filler causes a decrease in coating film strength, and should be used within a range that does not impair the effects of the present invention. Although it depends on the coating composition, it is recommended that the filler be added at 80% or less of the coating weight.

Examples of the inorganic filler include powders of talc, clay, diatomaceous earth, silica, calcium carbonate, zeolite, metal oxide and sulfur, and examples of the organic filler include a sugar polymer and its derivative, or crotylidene diurea, Powders of isobutylidene diurea, oxamide and the like can be used.

Further, in the present invention, a surfactant can be added within the range where the film strength and the elution control function are not impaired. The surfactant that can be used in the present invention may be a cationic one, an anionic one, an amphoteric one or a nonionic one, but the balance of hydrophilicity and hydrophobicity of the surfactant may be used. It is important and should be added according to the blending conditions of the coating.

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. In addition, OMUP (Blackylidene 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.

The coating material according to the present invention is used by being dissolved or dispersed in an organic solvent. The solvent used at this time is one that dissolves polymer materials and waxes typified by toluene, and is soluble in the aliphatic polyester essential to the present invention when heated, but cooled. In some cases, the aliphatic polyester is selected from the group of organic solvents which precipitates as fine crystals and becomes cloudy or becomes jelly-like. These coating solutions or solutions in which fillers are dispersed are sprayed onto the rolling or fluidizing fertilizer particles together with a high-speed hot air stream in the form of a spray, and the solvent is instantaneously dried to form the coated granules of the present invention. You can get fertilizer. When a powder is mixed and used as a filler in the coating film of the present invention, it is necessary to forcibly stir in a dissolution tank or the like so that the powder is uniformly mixed in an organic solvent without settling or floating. Hereinafter, the present invention will be described with reference to examples.

Example 1. Manufacturing Example of Fertilizer of the Present Invention Manufacturing Method 1 FIG. 1 shows a jet encapsulation device used in the manufacturing 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 the fertilizer input port 2
From the above, a predetermined hot air is introduced while passing (N ₂ gas) to form a jet flow. Hot air temperature T _1, the particle temperature during encapsulation T _2, the exhaust gas temperature is detected by thermometers T _a.
When T ₂ reaches a predetermined temperature, the encapsulating liquid is sprayed through the one-fluid nozzle 4 toward the spray 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 manufacturing example, a sample was prototyped while maintaining the following basic conditions. One-fluid nozzle: Opening 0.8 mm Full-con type Hot air volume: 4 m ³ / min Hot air temperature: 80 ± 2 ° C Fertilizer type: 6-7 mesh granular urea Fertilizer input amount: 10 kg Test solvent: Toluene Coating liquid concentration: Solid content 5.0 wt% Coating liquid supply rate: 0.3 kg / min * Coating liquid is sent from pump 5 to the nozzle, but 80
Superheat with steam so that the temperature does not drop below ℃. * Covering is performed while maintaining the above conditions until the prescribed coverage is achieved.

Manufacturing Method 2 Using the same coating apparatus as used in Manufacturing Method 1, in this Manufacturing Example, a sample was prototyped while maintaining the following basic conditions. One-fluid nozzle: Opening 0.8 mm Full-con type Hot air flow rate: 4 m ³ / min Hot air temperature: 100 ± 2 ° C Fertilizer type: 6-7 mesh granular urea Fertilizer input amount: 10 kg Test solvent: Perchlorethylene Coating solution concentration: Solid content 5.0 wt% Coating liquid supply rate: 0.3 kg / min * The coating liquid is sent from the pump 5 to reach the nozzle, but 10
Superheat with steam so that the temperature does not drop below 0 ° C. * Covering is performed while maintaining the above conditions until the prescribed coverage is achieved.

Manufacturing Method 3 Using the same coating apparatus as used in Manufacturing Method 1, in this Manufacturing Example, a sample was prototyped while maintaining the following basic conditions. One-fluid nozzle: 0.8 mm opening Full-con type Hot air flow rate: 4 m ³ / min Hot air temperature: 100 ± 2 ° C Fertilizer type: 6-7 mesh granular urea Fertilizer input amount: 10 kg Test solvent: Ethyl acetate Coating solution concentration: Solid Min 5.0 wt% Coating liquid supply: 0.3 kg / min * Coating liquid is sent from pump 5 to the nozzle, but 70
Superheat with steam so that the temperature does not drop below ℃. * Covering is performed while maintaining the above conditions until the prescribed coverage is achieved.

2. Evaluation of Prototype Samples Table 1 shows the composition of the coated granular fertilizer produced by the method of the production example.

[0032]

[Table 1]

Note to Table 1 * 1 Poly-3-hydroxy-3-methylpropionic acid Mw = 750,000 * 2 Talc average particle size 10 μm * 3 Ethylene / carbon monoxide copolymer MI = 0.75
CO = 0.95 wt% * 4 1,4 butanediol-succinic acid copolymer Mw
= 67,000 * 5 Low density polyethylene MI = 20 d = 0.92
2 * 6 Poly-L-2-hydroxy-2-methylacetic acid Mw = 150,000 * 7

[0034]

Embedded image

N = 400 * 8 ethylene / vinyl acetate copolymer MI = 20 V
Ac = 33 wt% * 9 Reagent product * 10 Reagent product * 11 Reagent product * 12 Vinylidene chloride / vinyl chloride copolymer Vcl =
10 wt% * 13 Clay Average particle size 10 μm * 14 Reagent product * 15 Copolymer-type atactic polypropylene containing 3% ethylene Mw = 60,000 * 16 Crotylidene diurea powder Average particle size 10 μm * 17 Syndiotactic 1,2-polybutadiene M
FI = 3 d = 0.901 * 18 Poly-D, L-2-hydroxy-2-methylacetic acid Mw = 150,000 * 19 Poly-L-2-hydroxy-2-ethylacetic acid Mw = 150,000 * 20 Ethylene glycol / succinic acid copolymer Mw =
65,000 * 21 m. Paraffin wax with p = 69 to 73 ° C. * 22 Iron oxide average particle size 10 μm * 23 Zeolite average particle size 10 μm * 24 Sulfur average particle size 10 μm * 25 1,4 butanediol-adipic acid copolymer 5
9,000 * 26 diatomaceous earth average particle size 10 μm * 27 calcium carbonate average particle size 10 μm * 28 naphthalene average particle size 10 μm

Damage Treatment Method An apparatus for comparing the impact resistance of trial-made coated granular fertilizer coatings is shown in FIG. The compressed air separately compressed by the compressor is adjusted by the valve 1 and is supplied to the pipe 5 through the orifice flow meter 2. The inner diameter of the pipe is 100 mm and the length L is 5 m.
The wind speed in the pipe is 50 m / sec. The prototype coated granular fertilizer is put into the hopper 3 and supplied to the pipe through the rotary valve 4. The prototype coated granular fertilizer was carried by the wind, and a part of it collided with the collision plate (shown in Fig. 3) provided in the pipe and was stored in the receiver 7. The remaining prototype coated granular fertilizer was repaired. The air is removed at 8 and is discharged into the atmosphere through the exhaust port 9. The prototype coated granular fertilizer stored in the receiver was taken out and used as a damage-treated sample. Evaluation of Prototype Samples 10 g of the trial-coated granular fertilizers before and after the damage treatment are immersed in 200 ml of water and left standing at 25 ° C. After a predetermined period, it is divided into fertilizer and water, and urea eluted in the water is determined by quantitative analysis. 200 ml of fresh water is added to the fertilizer, and the fertilizer is allowed to stand at 25 ° C. again, and the same analysis is performed after a predetermined period. By repeating such operations, the relationship between the total elution of urea dissolved in water and the number of days was graphed to prepare an elution rate curve.
You can know the number of days to reach the% dissolution rate. Table 2 shows the evaluation results. The 24-hour dissolution of the dissolution item in Table 2 is the dissolution rate in water after 25 hours at 25 ° C. in the dissolution measurement, and the 80% number of days of dissolution was determined by preparing an dissolution rate curve in the dissolution rate measurement. .

[0037]

[Table 2]

[0038]

INDUSTRIAL APPLICABILITY According to the present invention, a biodegradable polyester and a non-decomposable polyolefin, a copolymer of olefin and other polymerized units, or polyvinylidene chloride or vinylidene chloride and other polymerized units are copolymerized. With a coating containing one or more selected from coalescence as an active ingredient, a degradable coating that can control elution for a long period of time and has sufficient strength to withstand production, storage, distribution and use is realized. did it.

[Brief description of the drawings]

FIG. 1 is an apparatus for producing coated granular fertilizer according to the present invention.

FIG. 2 is an impact resistance evaluation device according to the present invention.

3 is an impact plate used in the apparatus of FIG.

[Explanation of symbols]

1 Jet Tower 2 Fertilizer Inlet 3 Exhaust Gas Outlet 4 One Fluid Nozzle 5 Pump 6 Liquid Piping 7 Fertilizer Plate Outlet 8 Heat Exchanger 9 Orifice Flowmeter 10 Blower 11 Liquid Tank 12 Pump 13 Liquid Tank T ₁ Thermometer T ₂ Thermometer T ₃ Thermometer 14 Valve 15 Orifice flowmeter 16 Hopper 17 Rotary valve 18 Piping 19 Impact plate 20 Receiver 21 Repair device 22 Discharge port 23 Compressed air

Claims (12)

[Claims] 1. A surface of a granular fertilizer comprising one or more polyesters having biodegradability and a polyolefin, a copolymer of an olefin and another polymerized unit, polyvinylidene chloride, or vinylidene chloride and another polymerized unit. Polyolefin coated with a resin coating containing any one or more of copolymers as an active ingredient, and further containing one or more substances accelerating the oxidative decomposition reaction of the polymer on the surface thereof, or an olefin and other polymerized units. Coated granular fertilizer having a degradable coating, characterized in that it is coated with a resin coating containing as an active ingredient any one or more of the above-mentioned copolymer or polyvinylidene chloride or a copolymer of vinylidene chloride and other polymerized units. . 2. A biodegradable polyester is represented by poly-3-hydroxy-3-alkylpropionic acid, poly-2-hydroxy-2-alkylacetic acid, polycaprolactone, and the following general formula (1). The coated granular fertilizer according to claim 1, which is an aliphatic polyester. Embedded image (Here, R ¹ and R ² are each an alkylene group having 2 to 10 carbon atoms) 3. The coated granular fertilizer according to claim 2, wherein the alkyl group of poly-3-hydroxy-3-alkylpropionic acid is a methyl group or an ethyl group. 4. The coated granular fertilizer according to claim 2, wherein the alkyl group of poly-2-hydroxy-2-alkylacetic acid is hydrogen, methyl group or ethyl group. Wherein R ¹ aliphatic polyester represented by the general formula (1) is an alkylene group having 2 or / and 4 carbon atoms, an aliphatic polyester represented by the general formula (1) R ²
Is an alkylene group having 2 or / and 4 carbon atoms.
The coated granular fertilizer according to 1. 6. A copolymer of polyolefin or olefin with other polymerized units is polyethylene, polypropylene, ethylene / propylene copolymer, ethylene / vinyl acetate copolymer, ethylene / carbon monoxide copolymer, ethylene / acetic acid. Vinyl / carbon monoxide copolymer, ethylene / acrylate copolymer, ethylene / methacrylic acid copolymer,
The coated granular fertilizer according to claim 1, which is at least one selected from rubber-based resins, polystyrene, polymethylmethacrylate, and the like. 7. The coated granular fertilizer according to claim 1, wherein the polyvinylidene chloride or its copolymer is polyvinylidene chloride or a vinylidene chloride / vinyl chloride copolymer. 8. The substance which promotes the oxidative decomposition reaction is -C =
8. One or more selected from unsaturated fatty acids having C-unsaturated bonds, unsaturated fatty acid esters, oils and fats, diene polymers, transition metals and transition metal compounds.
The coated granular fertilizer according to any one of 1. 9. The coated granular fertilizer according to claim 1, wherein the substance that promotes the oxidative decomposition reaction is sublimable fine particles. 10. The coated granular fertilizer according to claim 9, wherein the sublimable fine particle group is at least one selected from naphthalene, camphor, and sulfur. 11. The coated granular fertilizer according to claim 1, which is formed by mixing a poorly water-soluble or water-insoluble organic or inorganic filler in the coating. 12. The inorganic filler is one or more selected from powders of talc, clay, diatomaceous earth, silica, calcium carbonate, zeolite, metal oxide or sulfur, and the organic filler is a sugar polymer or its derivative, Alternatively, the coated granular fertilizer according to claim 11, which is one or more kinds selected from powders of clothylidene diurea, isobutylidene diurea, and oxamide.