JP3264810B2 - Coated granular fertilizer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a novel elution control technology for coated granular fertilizer which can maintain the fertilizing effect for a long period of time. More specifically, the present invention relates to an initially-suppressed slow-release coated granular fertilizer exhibiting the final elution after the initial elution is suppressed in accordance with the growth of a plant requiring a large amount of nutrients during the growing season.

[0002]

2. Description of the Related Art A slow-release coated fertilizer that controls the dissolution of fertilizer components by coating and encapsulating a granular fertilizer with a resin has great effects such as labor saving of agriculture and reduction of environmental load of fertilizer components. In recent years, its development has been remarkable. In other words, it prevents excessive fertilization, increases the efficiency of use of fertilizer components in crops, reduces the loss of fertilizer components to rivers, etc., and has a remarkable effect such as reducing the number of fertilizations. It is a well-known fact that it has achieved sufficient results for efficiency, efficiency and environmental conservation.

[0003] The most important point of the fertilization technique using the slow-release coated fertilizer is control of the dissolution rate of the fertilizer contained in the coated fertilizer. As a method of controlling the optimal dissolution rate for various crops, for example, Japanese Patent Publication No. 60-19552
Japanese Patent Publication No. 4-69598 discloses a technique using a coated fertilizer to which a hydrophilic resin is added, a technique described in Japanese Patent Publication No. 60-37074, and a technique using a coated fertilizer to which a hydrophilic resin and a surfactant are added. And the like, using a coated fertilizer to which the polyether / polyols described in (1) are added.

Further, considering the required amount of nutrients for plants, which require a larger amount of fertilizer during the growth period than at the childhood, the above-mentioned technique of coated fertilizer which shows a substantially uniform elution rate during the elution period is not sufficient. In recent years, studies on slow-release coated fertilizers having an initial dissolution inhibiting function, that is, coated fertilizers exhibiting sigmoid-type component dissolution, have been actively pursued. For example, an initial elution suppressing type coated fertilizer using a multilayer coating described in Japanese Patent Publication No. 5-29634, Japanese Patent Application Laid-Open No. 6-87684.
Japanese Patent Application Laid-Open No. 4-202078, a first layer containing an alkali substance and a second layer containing an alkali-soluble substance described in JP-A-4-202078. And an initial elution-suppressing type coated fertilizer using a coating composed of:

[0005] These coated fertilizers exhibiting elution of sigmoid-type components have realized high-performance fertilizers with higher utilization efficiency of fertilizer components. However, these initial elution-suppressing type coated fertilizers are not sufficient, and (1) the multilayer coating technique described in Japanese Patent Publication No. Hei 5-29634 discloses a ratio of the second layer (outer layer) to the first layer (inner layer). If the ratio is too high, full-scale elution in the latter half cannot be remarkably exhibited. Conversely, if the ratio is too low, the thickness itself of the second layer film becomes extremely thin, causing a variation in quality. (2) The elution control technique of adding a saccharide polymer described in JP-A-6-87684 is based on the drying treatment of the saccharide polymer. Insufficiency or poor dispersion of the saccharide polymer in the coating solution causes industrial problems such as extremely poor elution accuracy, and (3) JP-A-4-202078. , Alkali-soluble first layer and alkali-soluble The elution control technology comprising the second layer to which the substance is added cannot exert a sufficient effect unless the weight of the coating layer in the total weight is set to 10% by weight or more, deteriorating the quality as a fertilizer, and There was a problem of low industrial productivity due to the coating.

Further, Japanese Patent Publication No. 4-69598 discloses that
A coating technique in which a polyether polyol is dispersed is disclosed. However, as described on page 3 of the publication, the polyether polyol used in the present invention includes "polyethylene oxide and polypropylene oxide having OH groups at both ends. Or at least two O atoms per molecule
It is a “complex compound in which a polyalkylene oxide terminal group is bonded to another functional group and a plurality of molecules” having an H group.

However, these do not exhibit the initial inhibitory effect characteristic of the polyalkylene glycol having a specific structure having an OH group at one terminal used in the present invention. Also,
In Japanese Patent Publication No. 60-37074, "Polyoxyethylene alkyl ethers" is described on page 3 of coating technology in which a hydrophilic resin and a surfactant are added. It is necessary to use an alkyl ether having a large number of carbon atoms such as polyoxyethylene lauryl ether, that is, a compound having an HLB of 20 or less for use. On the other hand, the polyalkylene glycol whose main chain terminal is a lower alkyl ether having 1 to 4 carbon atoms used in the present invention has a low hydrophobic effect of the alkyl group, resulting in a high HLB and a high surfactant concentration. It does not fall into the category.

[0008]

SUMMARY OF THE INVENTION The present invention provides a coated granular fertilizer which can maintain the fertilizing effect for a long period of time and shows the elution of the fertilizing component in accordance with the growth of the plant. The sigmoid elution type, a so-called initial elution suppression type coated granular fertilizer that suppresses the elution of the active ingredient and shows this elution in the late stage when plant growth is remarkable, using a single-layer coating with high industrial productivity, the elution quality An object of the present invention is to provide a high-quality fertilizing component with little variation in the composition.

[0009]

Means for Solving the Problems As a result of intensive studies on the problems of the prior art as described above, the present inventor has found that by using a polyalkylene glycol having a specific structure as an elution controlling agent, even a single-layer coating is sufficient. Has been found to exhibit an effective initial elution suppression effect and to exhibit full-scale elution in the future.
The present invention has been reached. That is, the present invention relates to a granular fertilizer 10
0 parts by weight contained a polyalkylene glycol in which the main chain terminal was a lower alkyl ether having 1 to 4 carbon atoms.
It is a coated granular fertilizer characterized by being coated with 2 to 20 parts by weight of an olefin polymer resin, and as a preferred embodiment thereof, the coated granular fertilizer is characterized in that the lower alkyl ether is methyl ether. .

The sigmoid-type elution criterion in the present invention is defined as D80 (hereinafter, this D80 is referred to as “elution type”) when the number of days when 80% of the fertilizer component is eluted at 25 ° C. The elution rate in 1/4 of the days is 12% or less. In other words, if the fertilizer is a coated fertilizer that shows linear elution, the elution type shows 20% elution in the initial quarter period and the remaining three-quarters.
The elution of the sigmoid type is 12% of the elution type in the initial quarter period.
% Or less, and 68% or more in the remaining 3/4 period. More preferred sigmoid-type elutions are those that show less than 10% elution in the initial quarter period and more than 70% elution in the remaining three quarters of the elution type. . Those which show elution of more than 12% in the initial quarter period are not preferable because they are hardly called sigmoid type.

The preferred elution type in the sigmoid type elution is 40 days to 300 days, more preferably 60 days to 240 days. If it is less than 40 days, the initial elution suppression period is shorter than 10 days and the effect of the inhibition is difficult to appear, and if it exceeds 300 days, the initial elution suppression period exceeds 75 days, and the fertilization effect after fertilization is reduced. Expression is extremely slow, which is not preferable.

The details will be described below. (1) Polyalkylene glycol whose main chain terminal is a lower alkyl ether The polyalkylene glycol whose main chain terminal is a lower alkyl ether used in the present invention is a compound represented by the following general formula. R—O— (CHR′—CH ₂ —O) _n —H (wherein, R is an alkyl group having 1 to 4 carbon atoms; R ′ is any one of hydrogen and a methyl group; n is an integer of 5 or more) The lower alkyl ether is an alkyl ether having 1 to 4 carbon atoms, such as methyl ether, ethyl ether, propyl ether, isopropyl ether, butyl ether, n-butyl ether, isobutyl ether,
t-butyl ether. The alkyl ether may be one kind or a plurality of the above-described alkyl ethers. In the case where R is hydrogen and the structure has OH groups at both terminals and an alkyl ether having 5 or more carbon atoms, the initial suppression effect, which is a feature of the present invention, is insufficient. Among these alkyl ethers, preferred is methyl ether.

The polyalkylene glycol is at least one selected from the group consisting of an ethylene glycol polymer, a propylene glycol polymer, and an ethylene glycol-propylene glycol copolymer, and these may be used as a mixture. The main chain terminal used in the present invention has 1 to 4 carbon atoms.
The molecular weight of the polyalkylene glycol, which is a lower alkyl ether, is preferably from 200 to 500,000, more preferably from 300 to 100,000, and particularly preferably from 400 to 20,000. Molecular weight 200
In the following, the dissolution control becomes insufficient because the polyalkylene glycol dissipates from the film to the outside during the dissolution control period, and when the molecular weight is 500,000 or more, the effect of the main chain terminal is reduced. A sufficient effect cannot be obtained.

(2) Resin of olefin polymer The resin of the olefin polymer used in the present invention is, for example, ethylene homopolymer, ethylene-α-olefin copolymer, ethylene-carbon monoxide copolymer, ethylene- Vinyl acetate copolymer, saponified ethylene-vinyl acetate copolymer, ethylene-α-olefin-vinyl acetate copolymer,
Saponified ethylene-α-olefin-vinyl acetate copolymer, ethylene- (meth) acrylic acid copolymer, ethylene-α-olefin- (meth) acrylic acid copolymer, ethylene-alkyl (meth) acrylate Polymers, ethylene-α-olefin-alkyl (meth) acrylate copolymers, propylene homopolymers, propylene-ethylene copolymers, and propylene-α-olefin copolymers can be used. These resins may be used alone or in combination of two or more, and an appropriate compatibilizer may be used in combination. Among them, ethylene homopolymer, ethylene-α-olefin copolymer, ethylene-carbon monoxide copolymer, ethylene-vinyl acetate copolymer, saponified ethylene-vinyl acetate copolymer, ethylene-α- Olefin-vinyl acetate copolymer, ethylene-α-olefin-
Saponified vinyl acetate copolymer, ethylene- (meth) acrylic acid copolymer, ethylene-α-olefin- (meth) acrylic acid copolymer, ethylene-alkyl (meth) acrylate copolymer, ethylene-α Preferred are ethylene polymers such as -olefin-alkyl (meth) acrylate copolymers, and mixtures of two or more of these ethylene polymers.

The density of polyethylene represented by ethylene homopolymer and ethylene-α-olefin copolymer is 0.1.
It is preferably from 91 to 0.97 g / cm ³ , more preferably from 0.91 to 0.95 g / cm ³ . The production method is not limited, for example, those polymerized by a high pressure method, α-
Those copolymerized with an olefin and those copolymerized with an α-olefin by a low pressure method can also be suitably used. The MI of these polyethylenes is 0.1 to 100 g / 10 min (19
0 ° C, 2.16 kg load), more preferably 1 to 60/10 minutes (190 ° C, 2.16 kg load).

Ethylene-carbon monoxide copolymer, ethylene-vinyl acetate copolymer, saponified ethylene-vinyl acetate copolymer, ethylene α-olefin-vinyl acetate copolymer, ethylene α-olefin-vinyl acetate copolymer Saponified polymer, ethylene- (meth) acrylic acid copolymer, ethylene-α-olefin- (meth) acrylic acid copolymer, ethylene-alkyl (meth) acrylate copolymer,
The functional group content of the functional group-containing ethylene copolymer such as an ethylene-α-olefin-alkyl (meth) acrylate copolymer is preferably less than 50% by weight, more preferably 10% by weight or less. When the content of the functional group is 50% by weight or more, the effect of suppressing initial elution is reduced. These functional group-containing ethylene copolymers may be used by mixing the above-mentioned ethylene homopolymer or ethylene-α-olefin copolymer at an arbitrary ratio to reduce the apparent functional group content. Absent. The MI of these functional group-containing ethylene copolymers is 0.1 to 100 g / 10 min (at 190 ° C.,
2.16 kg load), more preferably,
0.5-60 / 10 minutes (190 ° C, 2.16 kg load)
It is.

(3) Coating The coated fertilizer referred to in the present invention refers to 100 parts by weight of granular fertilizer.
Resins 2 to 20 containing polyalkylene glycol having a lower alkyl ether having a main chain terminal of 1 to 4 carbon atoms
It was coated with parts by weight. When the amount of the resin is less than 2 parts by weight, coating defects (partially uncoated or partly thin coating) occur, and the initial elution suppressing effect does not appear. If the amount is more than the weight part, the quality as fertilizer is lowered, which is not preferable.

The state of presence of the polyalkylene glycol in the resin is determined by the compatibility between the polyalkylene glycol and the resin, and the structure and molecular weight of the polyalkylene glycol and the structure and molecular weight of the resin are appropriately determined. In combination, they may be dissolved until they cannot be separated,
It may be used by finely dispersing it to the order of microns. The weight ratio of the polyalkylene glycol whose lower end of the main chain is a lower alkyl ether having 1 to 4 carbon atoms to the resin is preferably from 0.05 to 99.95 to 10:90, more preferably from 0.1 to 99.9. The ratio is 7:93, particularly preferably 0.15: 99.85 to 5:95. When the weight ratio is less than 0.05 to 99.95, the effect of the above polyalkylene glycol does not appear, and the fertilizer becomes extremely slow-eluting. When the weight ratio exceeds 10:90, the effect of the above polyalkylene glycol is too large and the initial elution occurs. It tends to be a coated fertilizer that does not show an inhibitory effect.

The resin used in the present invention may be combined with a spherical and / or plate-like filler. The size of the filler is preferably from 0.1 to 50 μm, and more preferably from 0.2 to 30 μm. If it exceeds 50 μm, many coating defects tend to occur. As a filler, for example, talc, diatomaceous earth, kaolin, bentonite,
Inorganic fillers such as calcium carbonate, silica, mica, glass, and metal oxides such as alumina, or organic fillers such as starch, sugar compounds, chitin, chitosan, wood flour, clotilidene diurea, and mixtures thereof are preferably used. can do. Preferred are talc, diatomaceous earth, kaolin, bentonite, silica, mica, alumina, starch, sugar compounds, and mixtures thereof.

These fillers may be subjected to a surface treatment such as a silane treatment in order to improve the dispersibility in the resin, or may be subjected to a sieve treatment or the like in order to improve the uniformity of the coating, and the particle diameters thereof are made uniform. May be used. The mixing ratio of the filler is 60% by weight based on the total weight of the coating.
The following is preferred. If the amount of the filler exceeds 60% by weight, a sufficient initial elution suppressing effect cannot be obtained. Even when compounding with a filler is performed, the coating is preferably 2 to 20 parts by weight based on 100 parts by weight of the granular fertilizer.

That is, the resin and the main chain terminal have 1 to 1 carbon atoms.
The polyalkylene glycol as a lower alkyl ether of No. 4 and the filler have a composition ratio of 36 to 99.95, respectively.
% By weight, 10.00 to 0.02% by weight, 60 to 0% by weight
Is preferred. The method for forming a coating of the present invention includes:
There is no particular limitation, and the jet method in which the coating material is supplied with a solvent to the fertilizer flowing in the spout tower and dried with hot air, the coating material is supplied with the solvent to the fertilizer rolling in the rolling drum and dried with hot air A rolling method in which a coating material is supplied to a fertilizer that rolls in a rotating pan together with a solvent and dried with hot air, or a combination of these methods, for example, a jet pan method, can be used. There is no particular limitation on the spray nozzle that supplies the coating material together with the solvent, and a one-part nozzle, a two-part nozzle with gas assist, or the like can be used.

(4) Granular fertilizer The granular fertilizer used in the present invention is not particularly limited, and known granular chemical fertilizers can be used. For example, (a) urea,
Organic synthetic fertilizers such as isobutylidene urea, or (b)
Double salts containing at least one component selected from ammonia nitrogen, nitrate nitrogen, phosphoric acid, and potassium, such as phosphorus nitrate, potassium nitrate, NK Chemicals, ammonium sulfate, salt ammonium, ammonium nitrate, chloride potassium, sulfate potassium, and nitrate. Inorganic fertilizers (chemical fertilizers) such as soda, primary phosphorus, secondary phosphorus, potassium phosphate, lime phosphate, etc .; (c) magnesium salts, iron salts, molybdenum salts, manganese salts, copper salts, zinc salts; What added a trace element, such as a borate, can be used. These are (a), (b), (c)
And two or more selected from the above may be mixed. The shape of the granular fertilizer may be any of a spherical shape, a square shape, and a cylindrical shape, but a spherical shape is preferable for preventing coating defects. Further, the size is preferably 0.5 to 10 mm in diameter, and those having a diameter of less than 0.5 mm or more than 10 mm may cause trouble in handling during fertilization.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Fertilizers, resins, polyalkylene glycols and fillers used in the following examples are as follows. [Resin A] MI: 7.0 g / 10 min, density: 0.922
g / cm ³ high-pressure method low-density polyethylene (Ace Polyethylene M2270, manufactured by Asahi Kasei Kogyo Co., Ltd.) [Resin B] Ethylene-vinyl acetate copolymer (EVA) having an MI of 2.5 g / 10 min and a vinyl acetate content of 19% by weight Flex 460, manufactured by Mitsui DuPont Chemical) [PEG-A] Molecular weight of one end methylated 4,000
0 polyethylene glycol (Uniox M400
0, manufactured by NOF CORPORATION) [PEG-B] Molecular weight of 2,000 with one end methylated
0 polyethylene glycol (Uniox M200
0, manufactured by NOF CORPORATION) [PEG-C] molecular weight of 4,000 at both ends of OH groups
Polyethylene glycol (PEG # 4000, manufactured by Nippon Yushi) [PEG-D] Polyethylene glycol (nonionic K-230, manufactured by Nippon Oil & Fat) whose one end is lauryl ether [Talc] NK talc (manufactured by Wando Industry) [fertilizer A] Advanced Chemical Fertilizer 15-15-15, Phosphorus nitrate Akari (5 mesh sieve pass and 7 mesh sieve on with uniform particle size) [Fertilizer B] Chemical fertilizer 2-0-41, sulfate-based fertilizer (5 mesh) (Fertilizer C) chemical fertilizer 46-0-0, urea (5 mesh sieve pass and 7 mesh sieve on)

The abbreviations and analysis methods of the fertilizer components used for the elution evaluation are as follows. [AN] ammonia nitrogen (converted as N), indophenol method [NN] nitrate nitrogen (converted as N), 2,4-xylenol method [TN] total amount of AN and NN [TN elution rate] until a predetermined date [UN] urea nitrogen (converted as N), dimethylaminobenzaldehyde method [UN elution rate] The integrated value of the amount of TN eluted in water divided by the total TN content in the coated fertilizer and multiplied by 100 The integrated value of the amount of UN eluted into water up to a predetermined date is divided by the total UN content in the coated fertilizer and multiplied by 100. [WK] Water soluble Kari (converted as K ₂ O), flame photometry [WK dissolution rate] The integrated value of the dissolution amount of WK into water up to a predetermined date is divided by the total WK content in the coated fertilizer and multiplied by 100. Hereinafter, the present invention will be specifically described with reference to Examples and the like. And show its effect. In addition, Examples 1-3 and Comparative Examples 1-5 are:
In order to evaluate the fertilizer A of Phosphorus Akari, TN was used in Example 4.
In Comparative Example 6, WK was used as an evaluation of fertilizer B mainly composed of a potassium component, and Example 5 and Comparative Example 7 were used as UN in order to evaluate fertilizer C mainly composed of urea.

[0025]

Example 1 (1) Preparation of coating liquid 112.8 g of resin A, 7.2 g of PEG-A, and 120 g of talc were prepared as coating raw materials. Resin A and PE
GA is converted to a solvent, tetrachloroethylene 2,800.
The resulting solution was charged into the same ml, heated to 130 ° C. and maintained for 1 hour to prepare a uniform solution, and talc was mixed with stirring to prepare a coating solution. (2) Coating of fertilizer 3,000 g of fertilizer A was charged into a jet-type coating device described in JP-B-60-37074, and the bed temperature was set to 70.
The temperature was raised to 0 ° C., and the coating solution was supplied for 10 minutes to coat the fertilizer while maintaining the bed temperature at 70 ° C. by evaporating tetrachloroethylene with hot air at 110 ° C.
The obtained coated fertilizer weighed 3,235 g. (3) Component elution evaluation of coated fertilizer 3,235 g of the obtained coated fertilizer was reduced and 10 g of sampling was performed three times.
The dissolution in water was evaluated in a 25 ° C. incubator after adding pure water (ml). The elution type for TN of this coated fertilizer is 73 days, an initial quarter period of 18
The elution rate on the day was 2.7%, and a coated fertilizer showing sigmoid-type elution was obtained.

[0026]

Example 2 112.8 g of resin A was used as a coating material.
And fertilizer was coated in the same manner as in Example 1, except that 7.2 g of PEG-B and 120 g of talc were used. The obtained coated fertilizer weighed 3,238 g. When the elution was evaluated in the same manner as in Example 1, the elution type for TN was 70 days, and the elution rate on the 18th day, which was the first quarter period, was 3.5%, indicating that the sigmoid type was used. , A coated fertilizer exhibiting the dissolution of was obtained.

[0027]

Comparative Example 1 112.8 g of resin A was used as a coating material.
And fertilizer was coated in the same manner as in Example 1 except that 7.2 g of PEG-C and 120 g of talc were used. The obtained coated fertilizer weighed 3,236 g. When the elution was evaluated in the same manner as in Example 1, the elution type for TN was 69 days, and the elution rate on the 17th day, which was the first quarter period, was 25.2%, indicating that the non-sigmoid was used. A general coated fertilizer with mold elution was obtained.

[0028]

Comparative Example 2 114.0 g of resin A as a coating material
The fertilizer was coated in the same manner as in Example 1 except that PEG-D was 6.0 g and talc was 120 g. The obtained coated fertilizer weighed 3,236 g. When the elution was evaluated in the same manner as in Example 1, the elution type for TN was 64 days, and the elution rate on the 16th day, which is the first quarter period, was 38.6%, indicating that the non-sigmoidal A general coated fertilizer with mold elution was obtained.

[0029]

Example 3 116.4 g of resin A as a coating material
The fertilizer was coated in the same manner as in Example 1, except that PEG-A was 3.6 g and talc was 120 g. The obtained coated fertilizer weighed 3,237 g. When the elution was evaluated in the same manner as in Example 1, the elution type for TN was 140 days, and the initial quarter period was 35.
The elution rate on the day was 4.7%, and a coated fertilizer showing sigmoid-type elution was obtained.

[0030]

Comparative Example 3 106.8 g of resin A as a coating material
The fertilizer was coated in the same manner as in Example 1, except that PEG-A was 13.2 g and talc was 120 g.
The obtained coated fertilizer weighed 3,235 g. When the dissolution evaluation was performed in the same manner as in Example 1, the dissolution type relating to TN was 57 days, which was an initial quarter period of 14 days.
On the day, the elution rate was 29.0%, and a non-sigmoidal elution general coated fertilizer was obtained.

[0031]

Comparative Example 4 120.0 g of resin A as a coating material
And fertilizer was coated in the same manner as in Example 1 except that talc was changed to 120 g. The resulting coated fertilizer was 3,23
6 g. When the elution was evaluated in the same manner as in Example 1, the elution type for TN was 408 days, and the elution rate on the 102nd day, which is the first quarter period, was 17.1.
%, The dissolution was extremely slow, and a non-sigmoid dissolution coated fertilizer was obtained.

[0032]

Comparative Example 5 64.0 g of resin A was used as a coating material,
The fertilizer was coated in the same manner as in Example 1 except that the resin B was 56.0 g and the talc was 120 g. The obtained coated fertilizer weighed 3,238 g. When the elution was evaluated in the same manner as in Example 1, the elution type for TN was 75 days, and the elution rate on the 19th day, which was the first quarter period, was 26.9%. A general coated fertilizer with mold elution was obtained.

[0033]

Example 4 Except that fertilizer B was used instead of fertilizer A,
The fertilizer was coated in the same manner as in Example 1. The obtained coated fertilizer weighed 3,235 g. The dissolution evaluation was performed in the same manner as in Example 1 except that the dissolution was evaluated as the WK dissolution rate. The dissolution type related to WK was 68 days, and the dissolution rate on the 17th day, which is the first quarter period, was 2 days. .1%
A coated fertilizer exhibiting sigmoid-type elution was obtained.

[0034]

Comparative Example 5 114.0 g of resin A as a coating material
The fertilizer was coated in the same manner as in Example 4, except that PEG-D was 6.0 g and talc was 120 g. The obtained coated fertilizer weighed 3,236 g. When the elution was evaluated in the same manner as in Example 4, the elution type for WK was 63 days, and the elution rate on the 16th day, which was the first quarter period, was 17.2%, indicating that the non-sigmoid was not used. A general coated fertilizer with mold elution was obtained.

[0035]

Example 5 Fertilizer C was used in place of fertilizer A, and 238.8 g of resin A and 1.2 g of PEG-A were used as coating raw materials.
The fertilizer was coated in the same manner as in Example 1 except that the amount was changed to g. The resulting coated fertilizer weighed 3,232 g. Since fertilizer C is a urea-based fertilizer, dissolution evaluation was performed by UN. As a result, the dissolution type with respect to UN of the coated fertilizer was 92 days, and the dissolution rate on the 23rd day, which is the first quarter period, was 4.7%. Obtained.

[0036]

Comparative Example 7 238.8 g of resin A as coating material
The fertilizer was coated in the same manner as in Example 5, except that PEG-C was 1.2 g and talc was 120 g. The obtained coated fertilizer weighed 3,233 g. When the dissolution evaluation was performed in the same manner as in Example 5, the dissolution type for UN was 86 days, and the dissolution rate on the 22nd day, which is the first quarter period, was 28.1%, indicating that the non-sigmoid was not used. A general coated fertilizer with mold elution was obtained. The above Examples 1 to 5 and Comparative Examples 1 to 7 are collectively shown in Table 1, and TN, W
The elution rates of K and UN are shown in FIGS.

[0037]

[Table 1]

[0038]

According to the present invention, it is possible to obtain a coated granular fertilizer exhibiting elution of fertilizer components according to the growth of plants, thereby saving labor in the agricultural field and improving the utilization rate of fertilizer components.
And environmental conservation can be achieved.

[Brief description of the drawings]

FIG. 1 is a diagram showing the TN elution rate for each elapsed day in Examples 1 and 2 and Comparative Examples 1 and 2.

FIG. 2 is a diagram showing the TN elution rate for each elapsed day in Example 3 and Comparative Examples 3 to 5.

FIG. 3 is a graph showing the WK elution rate for each elapsed day in Example 4 and Comparative Example 6.

FIG. 4 is a view showing the UN elution rate for each elapsed day in Example 5 and Comparative Example 7.

Claims (3)

(57) [Claims] 1. A method for coating 100 parts by weight of a granular fertilizer with 2 to 20 parts by weight of an olefin polymer resin containing a polyalkylene glycol having a lower alkyl ether having a main chain terminal of 1 to 4 carbon atoms. Characterized coated granular fertilizer. 2. The coated granular fertilizer according to claim 1 , wherein the lower alkyl ether is methyl ether. 3. A polyalkylene glycol having a main chain terminal being a lower alkyl ether having 1 to 4 carbon atoms ;
The weight ratio of the resin of the polymer is 0.05 to 99.95.
Characterized in that from a 10 to 90 claim 1 or
3. The coated granular fertilizer according to 2.