JP2000302585A - Coated granular fertilizer with decomposable coating film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To concurrently satisfy the quality requirements of stable coating film decomposability with respect to various kinds of soil, elution controllability over a long period and mechanical properties of a coated granular fertilizer with a decomposable coating film by coating a granular fertilizer with a coating film material containing wax, an aliphatic polyester and an α-olefin polymer in their respective specified contents. SOLUTION: The production process of this coated granular fertilizer comprises coating a granular fertilizer with a coating film material containing 5-90 wt.% of wax, 5 to 90 wt.% of an aliphatic polyester and 5 to 60 wt.% of an α-olefin polymer, or spraying fertilizer granules in a jetted or tumbled state with the coating material, wherein: as the wax used, polyethylene wax is preferred on account of its elution controllability and decomposability and the weight average molecular weight of such wax is <10,000; as the aliphatic polyester used, polycaprolactone is preferred on account of its easy availability and stable decomposability; and as the α-olefin polymer used, polyethylene, polypropylene, an ethylene-butene copolymer, or the like, is preferred.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION Coated fertilizers are widely used in the field of agriculture and the like for the purpose of labor saving of fertilization, efficient expression of fertilizer in accordance with plant growth, and reduction of fertilization amount. The present invention relates to such a coated fertilizer, and in particular, the coating of the coated fertilizer has an appropriate and stable degradability in soil, and has practical properties such as long-term dissolution characteristics and impact resistance. And a method for producing the same.

[0002]

2. Description of the Related Art Coated fertilizers are used in a wide variety of fields such as agriculture because they can supply the fertilizer components according to the growth of crops and have high utilization efficiency. Many physical properties are required for coated fertilizers. The proper dissolution of the fertilizer component, which is the original feature, is transported, stored, has the necessary mechanical strength and various physical properties required for various stresses applied during use, Excellent productivity is required. In recent years, in addition to these properties, attempts have been made to improve the degradability of the coating of the coated fertilizer in the natural environment, such as decomposition by light, oxidative decomposition, and biological decomposition in soil. Applied methods are known. Of these, biodegradation
It has the characteristic that it can be decomposed even in soil not exposed to light and has excellent storage properties under normal conditions.

[0003] Several types of coated fertilizers coated with a biodegradable coating have been known. As an example using aliphatic polyesters, Japanese Patent Publication No. 7-5
No. 05-23517, to which polycaprolactone as described in Japanese Patent Application Publication No.
Examples of applying polyhydroxycarboxylic acid as described in JP-A-33577 and JP-A-7-61884, JP-A-7-315076, JP-A-8-15
There is an example in which a diol dicarboxylic acid type polyester as described in JP-A-7290 is applied.

[0004] On the other hand, coated fertilizers using wax are also known, and are disclosed in JP-A Nos. 10-231190 and 10-2.
No. 91880 discloses a coated fertilizer having a decomposable property of a coating. Further, the present applicants have studied a technique of using a wax and a polyester resin in combination, and have disclosed in Japanese Patent Application Laid-Open Nos. 7-33576 and 9-26.
The invention described in Japanese Patent No. 3476 was performed.

[0005] As described above, many attempts have been made to impart degradability to a coating with a biodegradable material and to improve the performance of the original coated fertilizer. However, a further problem that must be overcome is the stable degradability of the coating to various soils. That is, although the conventional coated fertilizer does have biodegradability, its decomposition stability is not sufficiently satisfactory depending on the type of soil and the number of continuous uses. At the same time, satisfactory properties have not been obtained in terms of simultaneously satisfying various physical properties required for the coated fertilizer, such as long-term dissolution control properties and mechanical properties.

[0006]

The problems to be solved by the present invention are, as described above, a problem with coated fertilizers such as the ability to decompose a stable coating on various soils, the ability to control elution over a long period of time, and the mechanical properties. An object of the present invention is to provide a coated granular fertilizer that can simultaneously satisfy various required physical properties, mechanical strength, productivity, and the like.

[0007]

Means for Solving the Problems As a result of intensive studies on the above problems, the present inventor has found that a coating material containing a specific amount of wax, a specific amount of aliphatic polyester, and a specific amount of α-olefin polymer is used. The present inventors have found that the coated granular fertilizer solves the above problems, and have completed the present invention. That is, the present invention relates to a coated granular fertilizer coated with a coating material containing 5-90% by weight of a wax, 5-90% by weight of an aliphatic polyester, and 5-60% by weight of an α-olefin polymer. Further, the present invention sprays a coating material containing 5-90% by weight of a wax, 5-90% by weight of an aliphatic polyester, and 5-60% by weight of an α-olefin polymer onto fertilizer particles in a jet or rolling state. And a method for producing a coated granular fertilizer.

The wax in the present invention includes petroleum wax such as paraffin wax, microcrystalline wax, petrolatum wax, synthetic hydrocarbon wax such as Fischer-Tropsch wax, polyethylene wax, modified polyethylene wax modified with carboxyl group, etc. Decomposition type polyethylene wax obtained by thermally or oxidatively decomposing polyethylene. The weight average molecular weight of these waxes is less than 10,000.
Among them, polyethylene wax is a preferred embodiment from the viewpoint of dissolution controllability and degradability. One of these waxes may be used alone, or two or more of them may be used in combination. In the present invention, the content of the wax in the coating material is 5 to 90% by weight.
And preferably 10 to 70% by weight. When the content of the wax in the coating material exceeds 90% by weight, the mechanical properties of the coating deteriorate, and the initial target dissolution controllability cannot be maintained. On the other hand, when the content of the wax in the coating material is less than 5%, stable decomposition of the coating film on various soils cannot be obtained.

The aliphatic polyester in the present invention is:
Examples thereof include polyesters obtained by polycondensation from aliphatic hydrocarbon diols and aliphatic hydrocarbon dicarboxylic acids, polycondensates of hydroxycarboxylic acids, and ring-opening polymers of cyclic esters. Aliphatic hydrocarbon diols have 2 to 20 carbon atoms
And ethylene glycol, to give a specific example.
Propylene glycol, trimethylene glycol, 1,
3-butanediol, 1,4-butanediol, 1,5
Examples thereof include -pentanediol and 1,6-hexanediol. On the other hand, the aliphatic hydrocarbon dicarboxylic acids are carboxylic acids having 2 to 24 carbon atoms, or esters or acid anhydrides thereof, and specific examples thereof include oxalic acid, malonic acid, succinic acid, glutaric acid, Examples thereof include adipic acid, pimelic acid, suberic acid, dimethyl succinate, dimethyl glutarate, dimethyl adipate, diethyl sebacate, succinic anhydride, glutaric anhydride, maleic acid, fumaric acid, dimethyl fumarate, and the like. Examples of polyesters obtained from these aliphatic hydrocarbon diols and aliphatic hydrocarbon dicarboxylic acids include polyethylene succinate, polyethylene adipate, polyethylene tetradecandeoate, polytetramethylene succinate, polytetramethylene adipate, and polyhexamethylene glutamate. And polyhexamethylene adipate. Examples of polycondensates of hydroxycarboxylic acids include polylactic acid and polyglutamic acid, and examples of ring-opening polymers include polycaprolactone. Among these aliphatic polyesters, preferred examples include polylactic acid, polycaprolactone, polyethylene succinate, polyethylene adipate and the like. Among them, polycaprolactone is particularly preferable in view of availability and stability of decomposition. In the present invention, the content of the aliphatic polyester in the coating material is 5 to 90%, preferably 5 to 50%. Furthermore, the content of the aliphatic polyester in the coating material exceeds 90% by weight,
If it is less than 5%, it will not be possible to obtain stable decomposability of the coating film on various soils.

The α-olefin polymer in the present invention includes a homopolymer of an α-olefin such as high-density or low-density polyethylene, polypropylene, poly-1-butene, ethylene / propylene copolymer, ethylene / 1-butene copolymer, ethylene -1-octene copolymer, butene-ethylene copolymer, copolymer of α-olefins such as butene-propylene copolymer, ethylene-ethyl methacrylate copolymer, ethylene such as ethylene-butyl methacrylate copolymer A weight average molecular weight of 10,000 or more of a copolymer of an α-olefin such as a methacrylate copolymer, an ethylene / vinyl acetate copolymer, an ethylene / carbon monoxide copolymer and a vinyl monomer or other monomers; Means Among these,
Preferred examples include polyethylene, polypropylene, ethylene / vinyl acetate copolymer, ethylene-butene, and ethylene-octene copolymer. From the viewpoints of elution controllability and mechanical strength, an ethylene copolymer is most preferred. The α-olefin polymer needs to have a molecular weight of 10,000 or more in view of its strength, and it is more preferable to use a polymer having a weight average molecular weight exceeding 30,000. These α-olefin polymers have a content in the coating material of 5 to 60.
% By weight, preferably 5 to 50% by weight. Further, when the content of the α-olefin polymer in the coating material exceeds 60% by weight, the decomposability of the coating decreases, and the effect of the present invention is hardly obtained. On the other hand, when the content is less than 5% by weight, the mechanical properties of the film are reduced, and it is difficult to maintain the elution controllability.

The substance of the present invention is a coated granular fertilizer obtained by coating a surface of a granular fertilizer with a coating material. The coating material may contain an inorganic or organic filler, if necessary, in addition to the wax, the aliphatic polyester and the α-olefin polymer. The inorganic filler refers to talc, clay, calcium carbonate, bentonite, silica, diatomaceous earth, metal oxides such as titanium oxide, sulfur powder and the like. Among these, talc and clay can be mentioned as preferred examples. Organic fillers include starch and modified starch, agar,
Refers to powders such as xanthone. The total amount of the inorganic filler and the organic filler is at most 80% by weight, preferably at most 70% by weight, based on the total weight of the coating material. The type and amount of these fillers affect the mechanical strength, dissolution property, decomposability, etc. of the film, and the amount should be determined in consideration of these points. In addition, since a hydrophilic organic filler such as starch greatly affects dissolution controllability, the amount should be determined in consideration of this point of view.

The coating material of the present invention can contain, in addition to these, conventionally known emulsifiers, coloring agents, lubricants and other additives. There is no particular limitation on the emulsifier that can be used, and conventionally known emulsifiers such as anions, nonions, and cations can be used. Among them, nonionic emulsifiers are preferred. The emulsifier is usually used in a range of 10% by weight or less, preferably 5% by weight or less based on the total weight of the coating material. As the coloring agent, coloring pigments and dyes such as carbon black and titanium white can be used. Examples of additives include anti-blocking agents for the purpose of preventing the particles from sticking to each other, conventionally known irons for promoting the decomposition of the polymer under light irradiation conditions, photodecomposition catalysts such as nickel complexes, And waxes. In addition, the above-mentioned reference | standard film | membrane material shall contain an inorganic or organic filler, these emulsifiers, additives, etc. other than a wax, an aliphatic polyester, and an alpha-olefin polymer.

The substance of the present invention is a coated granular fertilizer obtained by coating the surface of a granular fertilizer with the above-mentioned coating material mixture. There is no particular limitation on the granular fertilizer, and conventionally known ones can be used.
Preferred examples include urea, aldehyde condensed urea, isobutyraldehyde condensed urea, formaldehyde condensed urea, guanylurea sulfate, oxamide and other nitrogen-containing organic compounds, lime nitrogen, ammonium nitrate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate. , Ammonium sulfate, ammonium compounds such as ammonium chloride,
Potassium nitrate, potassium phosphate Potassium salts such as potassium sulfate and potassium chloride, calcium salts such as calcium phosphate, calcium sulfate, calcium nitrate and calcium chloride, magnesium salts such as magnesium nitrate, magnesium chloride, magnesium phosphate and magnesium sulfate, ferrous nitrate Iron salts such as ferric nitrate, ferrous phosphate, ferric phosphate, ferrous sulfate, ferric sulfate, ferrous chloride, ferric chloride, and the like; One or more composites can be used. These granular fertilizers may contain a conventionally known binder for the purpose of maintaining the form and mechanical strength of the granular fertilizer. Examples of the binder include molasses, lignin, and modified products thereof. The granular fertilizer preferably has a smooth surface and a shape close to a sphere. Specifically, when the area when the granular particles are captured as a planar image is S and the outer peripheral length is A,
It is preferable that particles having A ² / 4πS in the range of 1.00 to 1.15 account for 60% or more of the whole. The crushing strength of the granular fertilizer is preferably 0.4 kg or more, more preferably 1.0 kg or more.

The coated fertilizer in the present invention is a coated fertilizer in which the above-mentioned film is formed on the surface of a granular fertilizer, and the surface of the film may be further treated. For example,
It is possible to treat the inorganic powder for the purpose of improving the blocking of fertilizer particles, or to coat with wax or the like for the purpose of improving the angle of repose. The weight of the film covering the granular fertilizer is 1 to 30 parts by weight, preferably 3 to 30 parts by weight, and more preferably 3 to 20 parts by weight based on 100 parts by weight of the granular fertilizer. Exceeding this lower limit makes it difficult to control the eluted components as fertilizer. In addition, when the value exceeds the upper limit, there is a problem that the quality of the fertilizer deteriorates. The particle size of the coated granular fertilizer of the present invention is not particularly limited, but is usually 0.5 to 10 mm, preferably 1 to 5 m.
m. The shape of the coated granular fertilizer also depends on the shape of the raw fertilizer, but is preferably similarly close to a sphere, and preferably close to a true sphere with few irregularities.

Next, the present invention relates to a method for producing the coated granular fertilizer, wherein the coating material is sprayed on the fertilizer particles in a jet or rolling state. That is, a granular fertilizer is introduced into a jet or rolling device, and then, while maintaining the device at a predetermined temperature, a dispersion (solution) liquid containing a predetermined amount of a predetermined substance is supplied to manufacture a desired product. can do. The manufacturing method will be described below.

As the jet device or rolling device, a conventionally known device can be used. For these devices,
For example, it is disclosed in Japanese Patent Publication No. 54-3104. That is, it is a device in which a blower for sending hot air, a solution pump for sending a dispersion (solution) solution for coating, a spray nozzle, a thermometer, and the like are attached to the jet tower and the rolling tank body. A granular fertilizer to be coated is introduced into the device, and a gas at a predetermined temperature is blown from a blower or the like. In the case of a spout tower, it is adjusted so that a spout of fertilizer occurs stably in the apparatus. When the temperature inside the device reaches a desired temperature, a film can be formed on the surface of the granular fertilizer by supplying a predetermined dispersion (solution) solution from a spray nozzle. There is no particular limitation on the granular fertilizer, and those described above can be used. The particle size of the granular fertilizer may be appropriately set in consideration of the target particle size of the final product and the weight of the film. The shape of the granular fertilizer can greatly affect the performance of the coated fertilizer, and is preferably spherical. If the deviation from a true sphere is large, the dissolution and mechanical strength may be adversely affected.

Next, dispersion (melting) for forming a film
The liquid will be described. This dispersion (solution) liquid is a mixture of a resin component containing a wax, an aliphatic polyester and an α-olefin polymer, and if necessary, an inorganic or organic filler, various additives, and a solvent in which these are dissolved or dispersed. . The solvent used is preferably a solvent that dissolves wax, aliphatic polyester and α-olefin polymer. Preferred examples include aromatic solvents such as benzene, toluene, xylene and mesitylene, hexane, heptane, n-octane, 2-ethylhexane,
Examples include paraffins such as 2-ethylcyclohexane, and chlorinated hydrocarbons such as dichloromethane, trichloromethane, tetrachloromethane, trichloroethylene, and tetrachloroethylene. The above-mentioned dispersion (solution) liquid to be used in the production may be any as long as the contained one is dissolved or dispersed. From such a viewpoint, in the present specification, these mixtures are described as “dispersion (solution) liquid”. It is preferable that the wax, the aliphatic polyester and the α-olefin polymer are dissolved in the solvent, but the inorganic or organic filler is often used as a dispersion without being dissolved.

The solid concentration of the dispersion (solution) in the present invention is preferably 1 to 20% by weight, more preferably 3 to 20% by weight.
15% by weight. If the lower limit is deviated, the productivity is inferior. If the upper limit is deviated, the dissolution characteristics are adversely affected, and problems such as blocking are liable to occur. In forming the film, there is no particular limitation on the spraying temperature at the time of film formation, but usually a temperature of 30 ° C. or higher and a temperature at which particles do not adhere to each other is set. Specifically, 30-150 ° C
Degree, more preferably in the range of 30 to 100 ° C. The hot air should be set to a temperature and an air volume necessary for stably rolling or jetting the fertilizer particles and maintaining the above temperature. As these techniques, conventionally known techniques can be applied. INDUSTRIAL APPLICABILITY The coated fertilizer of the present invention has excellent mechanical strength, elution controllability, and film decomposability, and thus can be widely used as a fertilizer having a sustained release property. In particular, it is excellent in mechanical properties such as impact resistance, and is excellent in stable decomposability of a film in various types of soil, so that the load on the environment is small.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples and comparative examples of the present invention will be specifically described below. In addition, the test in an Example and a comparative example was based on the following method. <Water dissolution test> 5 parts by weight of the coated granular fertilizer was immersed in 200 parts by weight of distilled water. The fertilizer component dissolved in distilled water was measured at predetermined time intervals using a total agricultural soil analyzer ZA-II. The elution rate is expressed as a percentage of the eluted component relative to the fertilizer component contained in the original coated fertilizer.
The table shows the number of days required for 80% of the fertilizer component to elute, and the elution rate after three days (representing the initial elution rate).

<Soil Dissolution Test 1> 5 parts by weight of the coated granular fertilizer was mixed and buried in 200 parts by weight of field soil A (Shin-Fujima area) adjusted to 60% of the maximum water capacity. A plurality of samples prepared in the same manner were prepared and stored in a thermostat at 25 ° C. The fertilizer particles are collected from the soil at regular intervals, and the remaining fertilizer components are collected from the whole agricultural soil analyzer Z.
It was measured by A-II type. The elution rate is shown as a percentage of the eluted component relative to the fertilizer component contained in the original coated fertilizer, and Table 1 shows the number of days required for the fertilizer component to elute 80% of the whole.

<Soil Dissolution Test 2> The dissolution rate was determined in the same manner as described in the soil dissolution test 1 except that the field soil A (Shintokuma area) was changed to the field soil B (Shizuoka city area). It was measured. Table 1 shows the number of days required for 80% of the fertilizer component to elute. The evaluation of the stable degradability by the type of soil was such that the difference in the number of elution days between soil dissolution test 1 and soil dissolution test 2 was 1
Those that were equal to or longer than the number of elution days in water within 0 days were regarded as having decomposition stability.

<Impact resistance test> Using a backpack type power sprayer (Maruyama Seisakusho, MDJ60GTS-26), the coated granular fertilizer is sprayed under the conditions of an engine throttle 4 and a shutter opening 7 and discharged from the tip of the injection pipe. Recovered fertilizer. A dissolution test was performed on the coated fertilizer before the test and after the sprayer test, and the difference was expressed as the difference (ΔA) in the dissolution rate on the 10th day. Therefore, the smaller the value of ΔA, the stronger the impact resistance to the sprayer test. Table 1 shows the values of ΔA. When the value of ΔA was 10% or less, the mechanical properties of the coating were considered to be stable.

<Decomposition Test> 300 parts by weight of field soil was mixed with 60 parts by weight of the coated granular fertilizer, spread thinly in a frame without a bottom, and left outdoors. Among the coated granular fertilizers after 3 years, the ratio was shown as a percentage of the total of those which did not maintain the shape of the original film at all. If this value is 50% or more, it is determined that there is decomposability, and the larger the value is, the better the decomposability is.

[0024]

Example 1 A coated granular fertilizer was manufactured using a jet device.
Was. That is, ethylene / vinyl acetate copolymer (trade name
 Evaflex 310, DuPont Mitsui Polychemical
0.8 parts by weight, polycaprolactone (trade name)
 Praxel H7, manufactured by Daicel Chemical Industries, Ltd.)
8 parts by weight, polyethylene wax (brand name Neowak
Su L, manufactured by Yashara Chemical Co., Ltd.)
0 parts by weight of tetrachloroethylene are added and the boiling point of the solvent is
These were dissolved by heating to reflux. Further
In this solution, 3.8 parts by weight of talc, polyoxyethylene
Nonyl phenyl ether (HLB value 13) 0.2 weight
Was added and stirred sufficiently to prepare a dispersion. 2-4mm
Granular potassium nitrate potassium having an average particle size of 3.0 mm
(N, P_TwoO_Five, K _TwoO component is 15% each) 100 weight
Part into the jet device and blow hot air to reduce the temperature inside the device.
At 60 ° C., a stable jet state occurred. Next,
The prepared dispersion is sent from the spray nozzle by the feed pump.
It took 10 minutes to feed the jet device. During this time, the jet device
The temperature of the hot air was adjusted so as to be 55 ± 2 ° C. So
After that, the hot air is switched to the cold air, and when the temperature falls below 35 ° C
The contents were taken out from the jet device at. Manufactured coated manure
The feed is 108 parts by weight, and almost all of the supplied solids
Was found to be coated. The obtained coated granular fertilizer
The physical properties of the ingredients were evaluated, and the results are shown in Table 1. Got
In the coated granular fertilizer, elution of the fertilizer component is controlled,
Excellent impact resistance and decomposition of the film after use
Excellent in properties and decomposition stability.

[0025]

Example 2 Ethylene / vinyl acetate copolymer (trade name)
1.2 parts by weight of Evaflex 310, manufactured by DuPont-Mitsui Polychemicals Co., Ltd., and polycaprolactone (trade name: Placcel H7, manufactured by Daicel Chemical Industries, Ltd.)
6 parts by weight, 300 parts per 1.2 parts by weight of polyethylene wax (trade name Sun Wax 171P, manufactured by Sanyo Chemical Co., Ltd.)
A part by weight of tetrachloroethylene was added, and the mixture was heated and refluxed to the boiling point of the solvent to dissolve them. further,
To this solution, 3.0 parts by weight of talc was added, and the mixture was sufficiently stirred to prepare a dispersion. 2. average particle size sieved at 2-4 mm
100 parts by weight of 0 mm granular potassium phosphate nitrate (N, P ₂ O ₅ , and K ₂ O components are each 15%) are charged into the jetting device, and hot air is blown into the device to maintain a stable jetting condition at a temperature of 60 ° C. in the device. Awakened. Next, the dispersion liquid prepared above was supplied to the jet device from the spray nozzle by the liquid sending pump in 10 minutes. During this time, the temperature of the hot air was adjusted to 55 ± 2 ° C. in the jet device. After that, switch hot air to cold air,
When the temperature became 35 ° C. or lower, the contents were taken out of the jet apparatus. The produced coated fertilizer was 106 parts by weight, and it was found that almost all of the supplied solid matter was covered. Each physical property of the obtained coated granular fertilizer was evaluated, and the results are shown in Table 1. The obtained coated granular fertilizer is controlled in elution of the fertilizer component, is excellent in impact resistance, and is excellent in the decomposability and decomposition stability of the film after use.

[0026]

Example 3 1.0 part by weight of an ethylene-octene copolymer (trade name: Engage, manufactured by Dow Chemical Co., Ltd.); 1.0 part by weight of polycaprolactone (trade name: Praxel H7, manufactured by Daicel Chemical Industries, Ltd.) To 4.0 parts by weight of polyethylene wax (trade name Neowax ACL, manufactured by Yasuhara Chemical Co., Ltd.), 300 parts by weight of tetrachloroethylene was added, and the mixture was heated and refluxed to the boiling point of the solvent to dissolve them. In addition, talc 4.
0 parts by weight was added, and the mixture was sufficiently stirred to prepare a dispersion. 100 parts by weight of granular potassium phosphate nitrate (N, P ₂ O ₅ , and K ₂ O components are each 15%) having an average particle diameter of 3.0 mm sieved at 2 to 4 mm are put into a jet apparatus, and hot air is blown. When the temperature in the apparatus was 60 ° C., a stable jet state was generated. Next, the dispersion liquid prepared above was supplied to the jet device from the spray nozzle by the liquid sending pump in 10 minutes. During this time, the temperature of the hot air was adjusted to 55 ± 2 ° C. in the jet device.
Thereafter, the hot air was switched to cold air, and when the temperature became 35 ° C. or less, the contents were taken out from the jet device. The produced coated fertilizer was 110 parts by weight, and it was found that almost all of the supplied solid matter was covered. Each physical property of the obtained coated granular fertilizer was evaluated, and the results are shown in Table 1. The obtained coated granular fertilizer is controlled in elution of the fertilizer component, is excellent in impact resistance, and is excellent in the decomposability and decomposition stability of the film after use.

[0027]

Example 4 Ethylene / vinyl acetate copolymer (trade name)
Evaflex 310, 3.0 parts by weight, manufactured by Du Pont-Mitsui Polychemicals Co., Ltd., polycaprolactone (trade name: Placcel H7, manufactured by Daicel Chemical Industries, Ltd.)
To 0 parts by weight and 2.0 parts by weight of polyethylene wax (trade name Neowax ACL, manufactured by Yashara Chemical Co., Ltd.), 300 parts by weight of tetrachloroethylene was added, and the mixture was heated and refluxed to the boiling point of the solvent to dissolve them. Further, 4.0 parts by weight of talc was added to this solution, and the mixture was sufficiently stirred to prepare a dispersion. Granular potassium phosphate nitrate (N, P ₂ O ₅ , K ₂ O) having an average particle size of 3.0 mm sieved at 2-4 mm
(Each component is 15%) 100 parts by weight are charged into a jet device,
Hot air was blown to generate a stable jet state at a temperature of 60 ° C. in the apparatus. Next, the dispersion liquid prepared above was supplied to the jet device from the spray nozzle by the liquid sending pump in 10 minutes. During this time, the temperature of the hot air was adjusted to 55 ± 2 ° C. in the jet device. Thereafter, the hot air was switched to cold air, and when the temperature became 35 ° C. or less, the contents were taken out from the jet device. The produced coated fertilizer was 110 parts by weight, and it was found that almost all of the supplied solid matter was covered. Evaluate each physical property of the obtained coated granular fertilizer,
Table 1 shows the results. The obtained coated granular fertilizer is controlled in elution of the fertilizer component, is excellent in impact resistance, and is excellent in the decomposability and decomposition stability of the film after use.

[0028]

Example 5 Ethylene / vinyl acetate copolymer (trade name)
0.7 parts by weight of Evaflex 310, manufactured by Du Pont-Mitsui Polychemicals Co., Ltd., and polycaprolactone (trade name: Placcel H7, manufactured by Daicel Chemical Industries, Ltd.)
4 parts by weight, 300 parts per 2.8 parts by weight of polyethylene wax (trade name Sun Wax 171P, manufactured by Sanyo Chemical Co., Ltd.)
A part by weight of tetrachloroethylene was added, and the mixture was heated and refluxed to the boiling point of the solvent to dissolve them. further,
To this solution, 2.1 parts by weight of talc was added, and sufficiently stirred to prepare a dispersion. 2. average particle size sieved at 2-4 mm
100 parts by weight of 0 mm granular potassium phosphate nitrate (N, P ₂ O ₅ , and K ₂ O components are each 15%) are charged into the jetting device, and hot air is blown into the device to maintain a stable jetting condition at a temperature of 60 ° C. in the device. Awakened. Next, the dispersion liquid prepared above was supplied to the jet device from the spray nozzle by the liquid sending pump in 10 minutes. During this time, the temperature of the hot air was adjusted to 55 ± 2 ° C. in the jet device. After that, switch hot air to cold air,
When the temperature became 35 ° C. or lower, the contents were taken out of the jet apparatus. The produced coated fertilizer was 107 parts by weight, and it was found that almost all of the supplied solid matter was covered. Each physical property of the obtained coated granular fertilizer was evaluated, and the results are shown in Table 1. The obtained coated granular fertilizer is controlled in elution of the fertilizer component, is excellent in impact resistance, and is excellent in the decomposability and decomposition stability of the film after use.

[0029]

[Comparative Example 1] A coated granular fertilizer was manufactured using a jet device.
Was. That is, ethylene / vinyl acetate copolymer (trade name
 Evaflex 310, DuPont Mitsui Polychemical
1.4 parts by weight, polycaprolactone (trade name)
 Praxel H7, manufactured by Daicel Chemical Industries, Ltd.)
2 parts by weight, polyethylene wax (brand name Neowak
SACL, Yashara Chemical Co., Ltd.) 2.4 parts by weight
300 parts by weight of tetrachloroethylene are added and the solvent
These were dissolved by heating and refluxing to the boiling point. Sa
Further, 4.0 parts by weight of talc was added to this solution, and thoroughly stirred.
To prepare a dispersion. Average particles sieved at 2-4mm
Granular phosphoric acid potassium nitrate having a diameter of 3.0 mm (N, P_TwoO _Five, K_TwoO
(Each component is 15%) 100 parts by weight are charged into a jet device,
Hot air is blown and the temperature inside the device is stable at 60 ° C.
Awakened. Next, the dispersion prepared above
It takes 10 minutes from the spray nozzle by the jet
Supplied. During this time, the temperature inside the jet device will be 55 ± 2 ° C.
The temperature of the hot air was adjusted. Then cut hot air into cold air
When the temperature drops below 35 ° C, the contents are
I took it out. 108 parts by weight of the coated fertilizer produced
And that almost all of the supplied solids are covered.
I understood. Evaluate each physical property of the obtained coated granular fertilizer,
Table 1 shows the results. The obtained coated granular fertilizer is used
It was found that the decomposability of the later film was inferior.

[0030]

[Comparative Example 2] A coated granular fertilizer was manufactured using a jet device.
Was. That is, polycaprolactone (trade name Pluxe
Le H7, manufactured by Daicel Chemical Industries, Ltd.) 1.2 parts by weight,
Ethylene / vinyl acetate copolymer
310, manufactured by Mitsui Dupont Polychemical Co., Ltd.) 0.2
Parts by weight, polyethylene wax
ACL, manufactured by Yashara Chemical Co., Ltd.)
00 parts by weight of tetrachloroethylene were added,
These were dissolved by heat reflux to the point. Further
, 4.0 parts by weight of talc was added to this solution,
To prepare a dispersion. Average particle size sieved at 2-4mm
3.0 mm granular phosphoric acid potassium nitrate (N, P_TwoO _Five, K_TwoO
100% by weight is injected into the jetting device and heat
Blows air to maintain a stable jet at 60 ° C
Awakened. Next, the dispersion prepared above is supplied to a liquid sending pump.
Takes 10 minutes from the spray nozzle to the jet device
Supplied. During this time, the temperature inside the jet device should be 55 ± 2 ° C.
The temperature of the hot air was adjusted. Then switch hot air to cold air
When the temperature drops below 35 ° C, the contents are removed from the jet device.
Started. The produced coated fertilizer is 108 parts by weight,
It is clear that almost all of the supplied solids are covered.
won. Evaluate each physical property of the obtained coated granular fertilizer,
Table 1 shows the results. The resulting coated granular fertilizer is impact resistant
Turned out to be inferior.

[0031]

[Comparative Example 3] A coated granular fertilizer was manufactured using a jet device.
Was. That is, polycaprolactone (trade name Pluxe
2.6 parts by weight of Le H7, manufactured by Daicel Chemical Industries, Ltd.
Polyethylene wax (trade name Neo Wax ACL,
0.2 parts by weight of Yashara Chemical Co., Ltd.
Vinyl acetate copolymer (trade name Evaflex 310,
3 per 1.2 parts by weight of Mitsui Dupont Polychemical Co., Ltd.
00 parts by weight of tetrachloroethylene were added,
These were dissolved by heat reflux to the point. Further
, 4.0 parts by weight of talc was added to this solution,
To prepare a dispersion. Average particle size sieved at 2-4mm
3.0 mm granular phosphoric acid potassium nitrate (N, P_TwoO _Five, K_TwoO
100% by weight is injected into the jetting device and heat
Blows air to maintain a stable jet at 60 ° C
Awakened. Next, the dispersion prepared above is supplied to a liquid sending pump.
Takes 10 minutes from the spray nozzle to the jet device
Supplied. During this time, the temperature inside the jet device should be 55 ± 2 ° C.
The temperature of the hot air was adjusted. Then switch hot air to cold air
When the temperature drops below 35 ° C, the contents are removed from the jet device.
Started. The produced coated fertilizer is 108 parts by weight,
It is clear that almost all of the supplied solids are covered.
won. Evaluate each physical property of the obtained coated granular fertilizer,
Table 1 shows the results. The resulting coated granular fertilizer is used for soil seeds.
Degradability varies depending on the type of the product, and degradation stability is poor.
won.

[0032]

[Table 1]

[0033]

According to the present invention, the coating of the coated fertilizer has an appropriate and stable degradability in soil, and has excellent practical properties such as elution characteristics and impact resistance over a long period of time. A coated granular fertilizer can be provided.

Claims (5)

[Claims] 1 to 5% by weight of a wax, 5 to 90% by weight of an aliphatic polyester, and an α-olefin polymer 5.
A coated granular fertilizer coated with a coating material containing up to 60% by weight. 2. The coated granular fertilizer according to claim 1, wherein the wax is a polyethylene wax. 3. The coated granular fertilizer according to claim 1, wherein the aliphatic polyester is polycaprolactone. 4. The coated granular fertilizer according to claim 1, wherein the α-olefin polymer is an ethylene copolymer. 5. A fertilizer particle in a jet or tumbling state, comprising 5-90% by weight of wax and 5-% aliphatic polyester.
A method for producing a coated granular fertilizer, comprising spraying a coating material containing 90% by weight and 5 to 60% by weight of an α-olefin polymer.