KR101545799B1 - Coated granular fertilizer coated with disintegrating coating - Google Patents

Abstract

The present invention provides a coated granular fertilizer which can simultaneously satisfy mechanical strength, elution control property, productivity and the like required for a coating sample, has a rapid collapsing property of the coating, and is hard to float on the water surface of the surface. The coated granular fertilizer according to the present invention contains at least one? -Olefin (co) polymer (A) having a crystallization temperature (Tcmax) within a range of 95 ° C? Tcmax? 115 ° C, a crystallization temperature within a range of 65 ° C? Olefin (co) polymer (A) and wax (B) in the microstructure of the fertilizer coating is a granular fertilizer coated with a film containing at least one wax (B) and at least one filler (C) And the wax (B) is finely dispersed.

Description

≪ Desc / Clms Page number 1 > Coated granular fertilizer coated with disintegrating coating &

Various slow-acting fertilizers have been developed for the purpose of harvesting fertilizer or inducing ineffectiveness due to the growth of plants. Representative examples of slow-release fertilizers include coated fertilizers in which the surface of the fertilizer is coated with various resins or minerals. The present invention relates to such coated granular fertilizer, and it is an object of the present invention to provide a coated granular fertilizer which is excellent in film decayability after elution and has excellent practical properties such as elution characteristics and mechanical properties, So-called environmentally-friendly load-bearing granular fertilizer.

In recent years, there has been a problem in that the coating of the coated granular fertilizer put into the rice paddy (the shell after the completion of dissolution) is floated on the surface of the water during harvesting of the next year when it is fertilized and is discharged to the river. Particularly, as a fertilizer for water tanks, it is required as an important physical property that the coated granular fertilizer used in paddy fields does not float the film after completion of the elution.

Polyolefin resin, urethane resin, alkyd resin, sulfur and the like are often used as a coating material of the conventional coated granular fertilizer. Recently, in order to improve the degradability of the coating film, 5-201786 (Japanese Patent Application Laid-Open No. 7-91143), Japanese Patent Application Laid-Open No. 63-17286 (Japanese Patent Publication No. Hei 2-23516), Japanese Patent Laid-Open No. 8-59382 A technique disclosed in the publication is known. In addition, Japanese Patent Application Laid-Open No. 63-40789 (Japanese Patent Publication No. Hei 2-23517), Japanese Patent Application Laid-Open No. 3-146492, Japanese Patent Application Laid- 59382, and JP-A-7-33576 are known. However, these techniques are not necessarily sufficiently satisfactory in terms of the collapsing property of the coating film in the natural environment after the termination of the elution, and therefore, they do not have a satisfactory preventive effect on the coating film after the termination of the elution.

In addition, as a technique for reducing the floating rate of the coating after dissolution prevention in a rice plant, Japanese Patent Application Laid-Open No. 2002-242392 discloses a method for producing a coated granular fertilizer with a usual coating and then further coating with a hydrophilic material such as polyvinyl alcohol The coating on the hollow particles after the elution has been completed is in the form of a coating on the hollow particles (the coating is almost completely in the form of an overwhelmingly large amount as a coating floating on harnessing), and after the fertilizer dissolving solution or moisture disappears, It is impossible to completely prevent the generation of the air bubbles in the air.

Japanese Patent Application Laid-Open No. 5-201786 (Japanese Patent Application Laid-Open No. 7-91143) Japanese Patent Application Laid-Open No. 63-17286 (Japanese Patent Application Laid-Open No. 2-23516) Japanese Patent Application Laid-Open No. 8-59382 Japanese Patent Application Laid-Open No. 63-40789 (JP-A-2-23517) Japanese Patent Application Laid-Open No. 3-146492 Japanese Patent Application Laid-Open No. 8-59382 Japanese Patent Application Laid-Open No. 7-33576 Japanese Patent Application Laid-Open No. 2002-242392

A problem to be solved by the present invention is to provide a coated granular fertilizer which can simultaneously satisfy the mechanical strength, elution regulating property, productivity and the like required for a coating sample, has a rapid collapsing property of the coating, .

As a result of intensive investigation into the above problems, the present inventors have found that when an? -Olefin (co) polymer having a crystallization temperature in a specific range and a wax having a crystallization temperature within a specific range are used in combination in a coating film, (co) polymer and wax are phase-separated and the wax is finely dispersed, and that the granular fertilizer coated with such a film solves the above problems, and accomplished the present invention. That is, the present invention is as follows.

(1) at least one? -Olefin (co) polymer (A) having a crystallization temperature (Tcmax) within a range of 95 ° C? Tcmax? 115 ° C, at least one? (Co) polymer (A) and wax (B) are phase-separated in a microstructure of a fertilizer coating and a wax (B) and at least one filler (C) ) Is finely dispersed in the granular material.

(2) The coated granular fertilizer according to (1), wherein the wax (B) having a crystallization temperature within a range of 65 캜? Tcmax? 75 캜 is a curing oil or a solid fatty acid.

(3) The coated granular fertilizer according to (1) or (2), wherein the wax (B) in the coating film is contained in an amount of 20 to 60 mass% with respect to the total mass of the? -Olefin (co) polymer .

(4) at least one? -Olefin (co) polymer (A) having a crystallization temperature (Tcmax) within a range of 95 ° C? Tcmax? 115 ° C, at least one? (B) and at least one filler (C) is sprayed onto the granular fertilizer in a flowing state by means of a fractionation column (flow tower) system or a fluidized bed system, whereby the surface of the granular fertilizer A coated granular fertilizer according to any one of (1) to (3), which is obtained by a production method comprising a step of forming a coating film.

Since the coated granular fertilizer according to the present invention has a structure in which the? -Olefin (co) polymer (A) and the wax (B) are phase-separated and the wax (B) is finely dispersed in the microstructure of the fertilizer coating, After the fertilizer has eluted, the coating rapidly collapses to inhibit the formation of a film on the hollow particle, which is a problem in floating. In addition, such coated granular fertilizer can be produced by the same method as the conventional method for producing coated granular fertilizer using an? -Olefin (co) polymer (A), a wax (B) and a filler (C) But also satisfies the conditions required for conventional coated granular fertilizers such as elution characteristics and film strength. It is apparent from the results of the later examples that the coated granular fertilizer of the present invention has three advantages that the composition is good and the collapsibility is excellent and the coating is hardly lifted after harrowing when used in paddy fields.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a flow sheet
Fig. 2 is a view showing an example of a squeeze disc (orifice) used in the manufacturing apparatus of Fig. 1
3 is a TEM image of the cross-section of coated granular fertilizer of Example 1 (a), Comparative Example 3 (b), Comparative Example 5 (c) and Comparative Example 6 (d)

The? -olefin (co) polymer is a homopolymer of? -olefin or a copolymer of? -olefin and at least one other vinyl monomer. Specific examples include homopolymers of? -Olefins such as high-density or low-density polyethylene, polypropylene and poly-1-butene, homopolymers of ethylene-propylene copolymer, copolymers of ethylene and 1-butene, copolymers of ethylene and 1-octene, Copolymers of? -Olefins such as ethylene, propylene, butadiene, and butene-propylene copolymers; copolymers of? -Olefins such as ethylene-vinyl acetate copolymer and ethylene-carbon monoxide copolymer with vinyl monomers or other monomers.

In the present invention, as the? -Olefin (co) polymer (A), an? -Olefin (co) polymer having a crystallization temperature in the range of 95 ° C? Tcmax? Here, the crystallization temperature (Tcmax) in the present invention refers to a value measured by a differential scanning calorimeter (DSC). When the crystallization temperature is within the above range, when the wax (B) having a specific crystallization temperature is used in combination with the wax (B), it is possible to form a film capable of suppressing the floating problem in the natural environment, Generation of troubles such as clogging of piping and clogging of the nozzle at the time of manufacture are small.

The (-olefin) (co) polymer (A) having a crystallization temperature within the above range is not particularly limited, and an appropriate one of the? -Olefin (co) polymer (the product grade) exemplified above can be selected and used. Or low density polyethylene (including high pressure low density polyethylene (LDPE), straight chain short chain branched polyethylene (LLDPE), medium low pressure high density polyethylene (HDPE), metallocene catalyst straight chain short chain branched polyethylene (LLDPE) And particularly preferably low-density polyethylene. The polybutene may also be used as the? -Olefin (co) polymer (A). The? -olefin (co) polymer (A) may be used singly or as a mixture of two or more kinds.

It is preferable that the? -Olefin (co) polymer (A) to be incorporated in the coating film is constituted only by satisfying the above-mentioned condition concerning the crystallization temperature. However, (Co) polymer which does not satisfy the above-mentioned condition concerning the crystallization temperature as optional components is allowed to be used in combination with the? -Olefin (co) polymer (A) satisfying the above-mentioned condition concerning the crystallization temperature.

The? -Olefin (co) polymer (A) preferably has a density in the range of 0.920 to 0.975 g / cm 3 measured according to JIS K7112 in the production of the coating film. When the amount is within the above range, the coating of the coated granular fertilizer is easy to form and the solubility in an organic solvent is good, so that adjustment of the coating mixture is easy.

The? -Olefin (co) polymer (A) preferably has a weight average molecular weight measured by GPC of 20,000 or more and 250,000 or less, more preferably 30,000 or more and 200,000 or less in terms of the strength of the coating film. Here, the weight-average molecular weight measured by GPC was measured by placing a column (PLgel MIXED-B, manufactured by JEOL) on a high temperature GPC apparatus (PL-GPC210 type) manufactured by Polymer Laboratories Co., Refers to the value measured using standard polyethylene as an eluent, oven temperature 140 ° C and orthodichlorobenzene.

On the other hand,

Natural waxes (for example, plant waxes such as candelilla wax, carnauba wax, rice wax, wood wax and jojoba oil (hydrogenated wax), animal waxes such as beeswax, lanolin (hydrogenated), and wax Petroleum waxes such as paraffin wax (C40, C42), microcrystalline wax, petrolatum (soft, hard), and the like), mineral waxes such as wax, ozokerite,

Synthetic waxes such as synthetic waxes (e.g., synthetic hydrocarbons such as Fischer-Tropsch wax and polyethylene wax; modified waxes such as montan wax derivatives, paraffin wax derivatives and microcrystalline wax derivatives; cured castor oil (caster wax) Hydroxystearic acid amide, 12-hydroxystearic acid ester, fatty acids such as chlorinated hydrocarbons, fatty acid amides or esters, ketones, etc.),

Saturated fatty acids such as caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid,

.

The hydrogenated wax is also called a hardening oil and is obtained by hydrogenating (hydrogenating) the oil which is liquid at room temperature to increase the proportion of the saturated fatty acid having a higher melting point and solidifying it at room temperature. Among saturated fatty acids, those which are solid at room temperature are also referred to as " solid fatty acids ".

In the present invention, as the wax (B), a wax having a crystallization temperature in the range of 65 캜? Tcmax? 75 캜 is used. When the crystallization temperature is within the above range, the wax (B) is finely dispersed in the microstructure of the fertilizer film when it is used in combination with the? -Olefin (co) polymer (A) having a specific crystallization temperature. It is possible to form a film which has good collapse property and can suppress the floating problem to the water surface. In addition, the controllability of the film-forming property and the dissolution rate of the coated granular fertilizer is good and the fluctuation of the product quality during storage is small.

The wax (B) having a crystallization temperature within the above range is not particularly limited, and any suitable wax (grade of the product) may be selected and used. For example, waxes such as carnauba wax and rice wax; , Mineral waxes such as ozokerite and ceresin, petroleum waxes such as paraffin wax (C40 and C42), synthetic hydrocarbons such as Fischer-Tropsch wax, modified waxes such as montan wax derivatives, and hardened castor wax Hydrogenated wax (hydrogenated oil), and saturated fatty acids (solid fatty acids) such as behenic acid and lignoceric acid. Among them, hydrogenated wax (curing oil) such as hardened castor oil (castor wax) and saturated fatty acid (solid fatty acid) such as behenic acid and lignoceric acid are more preferable, and hardened castor oil (castor wax) is particularly preferable. Any one of these waxes (B) may be used alone, or two or more waxes may be used in combination.

The wax (B) to be blended in the film is preferably composed only of satisfying the above-mentioned condition concerning the crystallization temperature. However, it is preferable that the wax (B) It is acceptable to use a wax which does not satisfy the above-mentioned condition with the wax (B) satisfying the above-mentioned condition concerning the crystallization temperature.

The wax (B) is preferably 20 to 60 mass%, more preferably 30 to 50 mass%, based on the total mass of the? -Olefin (co) polymer (A) and the wax (B). Within the above range, controllability of the film thickness and elution rate of the coated granular fertilizer is good and the collapsing property of the film in a natural environment is good.

As the filler (C) in the present invention, an inorganic filler and an organic filler can be used. Examples of inorganic fillers include metal oxides such as talc, clay, calcium carbonate, bentonite, silica, diatomaceous earth and titanium oxide, and sulfur powder. Of these, talc and clay are preferable examples. The organic filler refers to starch (such as corn starch) and modified starch, agar, and xanthan powder. The content of the entire film of the filler (C) with respect to the mass (total mass of the film material excluding the solvent) is preferably from 30 to 65 mass%. Within the above range, the decay of the film and the control of dissolution are good. When the content is less than 30 mass%, the collapse property may be insufficient. When the content is more than 65 mass%, the mechanical strength required for the coating sample is insufficient, so that the elution controllability may become insufficient due to impact on the coating film during production.

In the present invention, the incorporation of a photocatalytic accelerator and / or an oxidative decomposition accelerator into the film is more preferable because it is obtained by the decomposition by microorganisms and the synergistic effect with photodegradation and acid decomposition. As the photolysis accelerator, various organometallic compounds can be mentioned. Examples of the organic metal compound include organic metal complexes and organic acid metal salts. Of these, organometallic complexes and carboxylic acid metal compounds are preferable because they are easily controlled in photodegradability. As specific examples, organometallic complexes containing metals selected from iron, cobalt, nickel, copper, manganese, silver, palladium, molybdenum, chromium, tungsten and cerium can be suitably used. Preferred examples of the complexing agent include? -Diketones,? -Ketoesters, dialkyldithiocarbamates, dialkyldithiophosphates, alkylxanthates and mercaptobenzothiazoles including acetylacetone, and more specifically, Nickel dibutyl dithiocarbamate, nickel diethyl dithiocarbamate and iron acetylacetoacetone complex are preferably used. Examples of the carboxylic acid metal compound include iron compounds such as caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, behenic acid, oleic acid, linoleic acid and linolenic acid . These may be added alone or in combination of two or more kinds. The oxidative decomposition accelerator is not particularly limited and various organic metal compounds may be mentioned. Examples of the organic metal compound include organic metal complexes and organic acid metal salts. Among them, manganese stearate, cobalt stearate, manganese oleate, cobalt oleate, manganese acetylacetone, and acetylacetone cobalt can be given as examples of the effect of oxidative decomposition in the absence of light as in soil.

The ratio of the organometallic compound to the total mass of the film is preferably 0.0001 to 1 mass%, more preferably 0.001 to 0.5 mass%. When an organometallic complex is used as the organometallic compound, it is preferably contained in an amount of 0.02 to 20 × 10 ^-6 mol / g, more preferably 0.1 to 10 × 10 ^-6 mol / g, based on the mass of the entire film . If the content is less than 0.02 x 10 < ^-6 > mol / g, the effect of addition is insufficient and if it is more than 20 x 10 < ^-6 > mol / g, If the ratio is above, the disintegrable property or decomposition property after use of the coated granular material is obtained, and original quality is maintained during storage.

The coating film may contain a surfactant if it does not impair the effect of the present invention. Examples of the surfactant include polyethylene glycol, polypropylene glycol, water-soluble substances such as polyalkylene glycol and polyvinyl alcohol by copolymerization of ethylene glycol and propylene glycol, ether such as polyethylene glycol-alkyl ether and polyethylene glycol-branched alkyl ether Ester type nonionic surfactants such as polyethylene glycol-alkyl ester, polyethylene glycol-branched alkyl ester, cationic surfactants, anionic surfactants, amphoteric surfactants, and mixtures thereof, .

The content of the surfactant is not particularly limited, but it is preferably in the range of 0.01 to 10 mass%, and more preferably in the range of 0.1 to 5 mass% with respect to the mass of the entire film. The surfactant helps improve the dispersibility of the filler in the dissolving solution or emulsion in which the coating material or the like is dissolved or dissolved in the solvent, and if it is within the above range, the effect is sufficient and does not affect the dissolution rate control.

It is also possible to easily distinguish the coated granular fertilizer by adding a colorant such as an organic pigment, carbon black, or titanium white to the film.

The granular fertilizer to be coated is not particularly limited and any conventionally known fertilizer can be used. Preferable examples of the fertilizer component of the granular fertilizer include nitrogen-containing organic compounds such as urea, aldehyde condensation element, isobutylaldehyde condensation element, formaldehyde condensation element, guanyl sulfate element and oxamide, ammonium nitrate, ammonium dihydrogen phosphate, ammonium dihydrogen phosphate , Ammonium salts such as ammonium sulfate and ammonium chloride, nitrate compounds such as sodium nitrate, potassium salts such as potassium nitrate, potassium phosphate, potassium sulfate and potassium chloride, calcium salts such as calcium phosphate, calcium sulfate, calcium nitrate and calcium chloride, Magnesium chloride, magnesium chloride, magnesium phosphate and magnesium sulfate; magnesium salts such as ferric nitrate, ferric nitrate, ferrous phosphate, ferric phosphate, ferrous sulfate, ferric sulfate, Iron salts such as ferric chloride, and complex salts thereof, or complexes of two or more thereof.

These granular fertilizers may contain a conventionally known binder in order to maintain their shape and mechanical strength as a granular form. Examples of the binder include pulp molasses, lignin sulfonates and their modified products.

The thickness of the coating film can be appropriately selected depending on the type and composition of the coating material, the size of the fertilizer particles to be coated, and the dissolution pattern of the intended fertilizer component, but is preferably 10 to 100 mu m, more preferably 20 to 70 mu m on average . The covering ratio (the ratio of the film mass to the whole coated granular fertilizer) is preferably from 1 to 20 mass%, more preferably from 2 to 15 mass%. If this lower limit is exceeded, adjustment of the eluted component as fertilizer may become difficult. In addition, when the upper limit is exceeded, there may arise a problem of declining as fertilizer.

There is no particular limitation on the particle diameter of the coating-use fertilizer particles of the present invention, but the average particle diameter is usually 0.5 to 10 mm, preferably 1 to 5 mm. It is also preferable that the shape is close to spherical. Specifically, the circularity coefficient obtained by the following formula is preferably 0.7 or more, more preferably 0.75 or more, and still more preferably 0.8 or more. The maximum value of the circularity coefficient is 1, and the closer to 1, the closer the particle is to the circle, and the circularity coefficient decreases as the particle shape collapses from the circle.

The coated granular fertilizer of the present invention can be produced in the same manner as general coated granular fertilizers except that the specific? -Olefin (co) polymer (A), the wax (B) and the filler (C) have. For example, a dispersion or a solution containing a film component, or a step of forming a film on the surface of the granular fertilizer by spraying the melt to the granular fertilizer in a flowing state, Is used. From the reason that the suppression of the initial elution is good, the production method using the dispersion or the solution is preferable to the production method using the melt.

In order to bring the granular fertilizer into a fluid state, for example, granular fertilizer may be introduced into the granulation (jet flow) apparatus to cause classification. For this purpose, it is sufficient to use an apparatus of a fractionation tower method or a fluidized bed method, preferably a fractionation tower method. Fig. 1 and Fig. 2 show a schematic view of a fractionation column method used in the production method of the present invention.

(A), wax (B) and filler (C) having a specific crystallization temperature according to the present invention, or a solution or melt containing the filler (A) and wax (B) are phase-separated and the wax (B) is finely dispersed in the microstructure of the fertilizer coating. The phase separation structure of such a microcrystal can be confirmed by observation with a TEM (transmission electron microscope) or the like.

Example

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

The crystallization temperature (Tcmax) of the? -Olefin (co) polymer and the wax of Examples and Comparative Examples was measured according to the following measurement method.

The sample 5 ± 0.5 mg was heated to 200 ° C at a rate of 5 ° C / min using a differential scanning calorimeter (DSC, DSC-60 manufactured by Shimadzu Corporation) and kept at 200 ° C for 5 minutes. An exothermic curve was obtained when the temperature was lowered to 5 ° C, and the peak temperature was defined as the crystallization temperature (Tcmax).

The α-olefin (co) polymer used in Examples and Comparative Examples, the abbreviation of the wax and the crystallization temperature (Tcmax) are shown in Table 1.

PO1: low-density polyethylene "Suntec-LD M2270" (manufactured by Asahi Chemical Industry Co., Ltd.)

PO2: low-density polyethylene "Suntec-LD M2203" (manufactured by Asahi Chemical Industry Co., Ltd.)

PO3: low-density polyethylene "Suntec-LD M2504" (manufactured by Asahi Chemical Industry Co., Ltd.)

PO4: linear low density polyethylene Trade name "Novatec -LL UF331" (manufactured by Japan Polyethylene Corporation)

PO5: high-density polyethylene "Suntec -HD J300" (manufactured by Asahi Chemical Industry Co., Ltd.)

PO6: Ethylene / 1-octene copolymer "ENGAGE 8150" (manufactured by Dow Chemical Japan)

PO7: Ethylene-vinyl acetate copolymer "EVAFLEX 360" (manufactured by Mitsui DuPont Chemical Co., Ltd.)

WAX1: Caster wax Product name "Caster wax # 100" (manufactured by Kokura Synthetic Industrial Co., Ltd.)

WAX2: Caster wax Product name " Caster wax A flake "

WAX3: lignoceric acid "reagent tetracosanoic acid" (manufactured by Kanto Chemical Co.)

WAX4: polyethylene wax Product name "CP ADWAX CPW90F" (manufactured by Nissho)

WAX5: microcrystalline wax " POLYLETS MPS-75 " (manufactured by Chusei Oil)

The abbreviations and contents of the? -Olefin (co) polymer and the coating material other than the wax used in the examples and comparative examples are as follows.

Talc: average particle diameter 10 탆

Cornstarch: particle size 12 ~ 18 ㎛

SA: hexaoxyethylene nonylphenyl ether (surfactant)

Fe: stearic iron (III) (manufactured by Kishida Chemical Co., Ltd., reagent grade, purity: 99% or more) (photolysis accelerator)

≪ Apparatus for producing coated granular material &

1, the fractionation column 1 had a columnar column of a diameter of 1,300 mm in column diameter (inner diameter), 8,500 mm in height, and 50 degrees in cone angle And has a granular fertilizer input port 15 and a granular granular fertilizer outlet port 13. The spray nozzle 2 is a circular-fluid spray nozzle, and 3 is granular fertilizer (core material). 6 is a solid gas separator, and 7 is a condenser. 8 is a blower (Roots type), and 12 is a heater. Reference numeral 9 denotes a preparation tank (melting tank) for mixing a reaction mixture with a stirrer, and 10 denotes a feed pump (diaphragm type). 14 is a guide tube (300 mm in diameter, 1,760 mm in length, covered with a fluorine resin), and 11 is a rectifying can. 21 is a squeeze disc.

Details of the squeeze disc 21 are shown in Fig. 2, the spray nozzle 2 was provided at the center of each spray hole 23, with a diameter of 154 mm, an inner diameter 45 mm of the spray hole 23, four spray holes (aperture ratio 34%). Further, the spray nozzle 2 was arranged on a circle having a diameter of 95 mm centered on the center of the squeezing disc 21.

≪ Process for producing coated granular fertilizer >

The coated granular fertilizer was prepared by the following method using the above production apparatus. The heated air stream flows from the lower part of the separation column 1 toward the upper part, passes through the solid gas separator 6, and the air stream is cooled in the condenser 7 to condense and recover the organic solvent. The airflow passing through the condenser 7 passes through the heater 12 from the blower 8 and is heated and circulated so as to be guided to the classification tower 1 again as a hot air stream. First, the granular fertilizer (core material) 3 is fed from the granular fertilizer input port 15 while blowing air maintained at 150 ° C. in the jet hole 23 to the fractionation tower 1 by using the blower 8 And the granular fertilizer 3 is put in a sorted state. At this time, the flow rate and temperature of the heated air stream were adjusted so that the granular fertilizer temperature was 65 ± 2 ° C. The flow rate of the airflow was controlled by measuring with a flow meter installed between the blower 8 and the rectifying can 11, and the temperature of the heated air stream was adjusted while measuring the granular fertilizer temperature and the outlet temperature of the fractionation tower. The circulating air volume is 3,000 ㎥ / h and the input amount of granular fertilizer is 1,000 ㎏.

As the granular fertilizer, an urea (particle diameter: 3.0 mm to 3.6 mm, average particle diameter: 3.4 mm) was used.

≪ Examples 1 to 16 and Comparative Examples 1 to 6 >

The coated granular fertilizer was produced by using the above production apparatus according to the film material composition (unit mass%) and the film mass (the mass of the coating film on the coated granular fertilizer) shown in Table 2. As a result, the coated granular fertilizer was obtained in Examples 1 to 16 and Comparative Examples 1, 3, 5, and 6 without problems in manufacturability, but in Comparative Examples 2 and 4, there was a problem in manufacturability and no coated granular fertilizer was obtained. Therefore, the following characteristic evaluation was performed using only the coated granular fertilizer obtained in Examples 1 to 16 and Comparative Examples 1, 3, 5, and 6.

<Characteristic evaluation of coated granular fertilizer>

(I) Observation of structure of coating

For each of the coated granular fertilizers obtained in the above Examples and Comparative Examples, the structure of the coating section was observed with the following apparatus.

Device: TEM HITACHI H-7100

Condition: 125 kV

As a result of observation of the cross-section of the coating, it was confirmed that PO1 and WAX1 were phase-separated and WAX1 was finely dispersed in the coated cross-section of the coated granular fertilizer of Example 1 and Examples 7 to 16. Also in Example 2 and Example 3, PO1 and WAX2 (WAX3) were phase-separated and WAX2 (WAX3) was finely dispersed. Also in Examples 4 to 6, PO2 (PO3, PO4) and WAX1 were phase-separated and WAX1 was finely dispersed.

On the other hand, the coated cross-section of the coated granular fertilizer of Comparative Example 1 was only WAX1. In Comparative Example 3, the phase separation of PO1 and WAX4 was not observed and the structure of WAX4 was not finely dispersed. In Comparative Example 5, the phase separation of PO1, PO6 and WAX4 was not observed, and PO6 and WAX4 were not finely dispersed. Also in Comparative Example 6, the phase separation between PO1 and PO7 was not observed, and the PO7 was not finely dispersed.

3 (a) to 3 (d) show the TEM images of the coated cross-sections of the coated granular fertilizers of Example 1, Comparative Example 3, Comparative Example 5 and Comparative Example 6, respectively. In Example 1 (a), WAX1 appears as a white round contrast and is finely dispersed in a matrix of PO1 (lamellar structure). On the other hand, in Comparative Example 3, Comparative Example 5, and Comparative Example 6 (b, c, and d), phase separation is not observed and only the lamellar of polyolefin appears in the image.

(II) Evaluation of dissolution characteristics

5 g of each coated granular fertilizer obtained in the above-mentioned Examples and Comparative Examples was placed in a polyethylene outlet, filled with 200 ml of distilled water, and the plug was sealed. This dissolution was maintained in an incubator at 25 ° C. and after 7 days elapsed, the total nitrogen eluted into the distilled water was measured. The dissolution rate of the coated granular fertilizer is expressed as a percentage of total nitrogen eluted to the total nitrogen contained in the original coated granular fertilizer. It was judged that the dissolution characteristics were good when the dissolution rate obtained by the above method was 10% or less.

(III) Evaluation of Film Strength (Power Spreader Test)

500 g of each coated granular fertilizer obtained in the examples and comparative examples was discharged from the tip of the tube (injection tube) under the conditions of engine throttle 4 and shutter opening degree 7 using a bag-type power distributor (Maruyama Seisakusho, MDJ60GTS-26) The coated granulated fertilizer was recovered. 20 g of the coated granular fertilizer before the test and 20 g of the granular granular fertilizer recovered from the spreader together with 400 ml of distilled water were placed in a polyethylene bag and kept in an incubator at 25 ° C. Ten days later, each sample was picked from an incubator, sample liquid was sampled, and total nitrogen was measured to calculate the dissolution rate of each coated granular fertilizer. It was judged that the film strength was good when the value obtained by subtracting the dissolution rate of the coated granular fertilizer before the test from the dissolution rate of the coated granular fertilizer after the spreader test was 10% or less.

(IV) Evaluation of collapsibility

Each of the coated granular fertilizers obtained in the above Examples and Comparative Examples was put into water to elute the fertilizer components and dried for 1 month in a ventilation dryer set at 45 캜. As shown in Fig. 3, the obtained hollow coated particles were charged with 25 particles each into sea sand (20 to 35 mesh) under agitation at 300 rpm, and after 5 minutes, the particles were recovered and the collapse rate was calculated from the following formula.

It was judged that the calculated decay rate was 70% or more and that less than 70% was unsatisfactory.

(V) Evaluation of injuries

The cultivation of water plants using each of the coated granular fertilizers obtained in the above Examples and Comparative Examples was carried out for 2 consecutive years in a field in Ionami-ku, Susono City, Shizuoka Prefecture. Fertilization was conducted once in the first year and twice in the next year.

After one year, the packing was harrowed and the injured particles were recovered and the rate of injury for the first year was calculated from the following formula.

After two years, the packing was harrowed and the injured particles were recovered and the rate of injury for the second year was calculated from the following equation.

1. Classification tower (jet tower)
2. Spray nozzle
3. Granular fertilizer (core material)
4. Circulation air piping
5. Mixture supply piping
6. Solid gas separator
7. Condenser
8. Blower
9. Preparation of coating mixture (melting tank)
10. Pumping pump
11. Rectified can
12. Heater
13. Granular fertilizer outlet
14. Guide tube
15. Granular fertilizer input
21. Squeeze disc
22. Disc body
23. Spout

Claims (4)

At least one? -Olefin (co) polymer (A) having a crystallization temperature (Tcmax) within a range of 95 占 폚? Tcmax? 115 占 폚, at least one wax (B) having a crystallization temperature within a range of 65 占 폚? Wherein the wax (B) in the coating film is coated with a coating containing at least one filler (C) in an amount of 20 to 60 mass% based on the total mass of the? -Olefin (co) polymer (A) and the wax (B) % Of the total amount of the wax (B) and the wax (B) is finely dispersed in the microstructure of the coating film of an olefin (co) polymer (A) and the wax (B). The method according to claim 1,
Wherein the wax (B) having a crystallization temperature within a range of 65 캜? Tcmax? 75 캜 is a hardened oil or a solid fatty acid. The method according to claim 1,
At least one? -Olefin (co) polymer (A) having a crystallization temperature (Tcmax) within a range of 95 占 폚? Tcmax? 115 占 폚, at least one wax (B) having a crystallization temperature within a range of 65 占 폚? And a step of forming a coating film on the surface of the granular fertilizer by supplying a dispersion or a solution or a melt containing at least one filler (C) to the granular fertilizer in a flowing state by a fractionation tower type or fluidized bed type apparatus in the form of powder By weight based on the total weight of the granular fertilizer. delete

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