JPH09132493A - Coated granular fertilizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce the sigmoid dissolution type fertilizer which shows the corresponding dissolution of fertilizer active ingredients to the growth of a plant and has a lesser variation in dissolved fertilizer quality and contains sufficient amounts of the high quality fertilizer active ingredients, with high industrial productivity by coating a granular fertilizer with a specific resin. SOLUTION: In the production of this coated fertilizer, a granular fertilizer (A) is obtained by granulating a mixture of at least two components selected from an organic synthetic fertilizer (component (a)) such as urea, a double salt (component (b)) contg. at least one constituent selected from ammonia nitrogen, nitrate nitrogen and potassium phosphate and a minute amount of a salt (component (c)) such as magnesium or iron salt, into spherical granules each having a 0.5 to 10mm diameter. Then, 100 pts.wt. of the granular fertilizer (A) is coated with 2 to 2O pts.wt. of a resin that is obtained by dissolving or dispersing a polyalkylene glycol (B) which has a molecular weight of 200 to 500,000 and each of the main chain terminal groups of which is a C1 to C4 lower alkylene ether group, into a thermoplastic resin (C) consisting of an olefinic polymer in an amount sufficient to provide a B/C ratio by weight of 0.05/99.95 to 10/90 and if necessary, further compounding the resulting resin composition (B+C) with <=60wt.% of a filler having a 0.1 to 50μm size, based on the total weight of these components of the coating material to be applied, to form a coating film on each of the granules of the fertilizer (A) by using a jet, tumbling or rotary pan process, or the like. Thus, the objective coated granular fertilizer can be produced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel elution control technique for coated granular fertilizer, which can maintain fertilization effect for a long period of time. More specifically, the present invention relates to an early-inhibition-type slow-release coated granular fertilizer that shows the main elution in the later stage after suppressing the elution in the early stage in accordance with plant growth that requires a large amount of nutrients during the growing period.

[0002]

2. Description of the Related Art A slow-release coated fertilizer that controls the elution of fertilizer components by coating a granular fertilizer with a resin and encapsulating the fertilizer components has great effects such as labor saving in agriculture and reduction of environmental load of fertilizer components. In recent years, its development has been remarkable. In other words, it is possible to prevent excessive fertilization, improve the utilization efficiency of fertilizer components to crops, reduce the loss of fertilizer components to rivers, etc., and further reduce the number of times fertilizer is applied. It is a well-known fact that it has achieved sufficient results in terms of efficiency, efficiency, and environmental protection.

The most important point of the fertilization technique using the slow-release coated fertilizer described above is the control of the elution rate of fertilizing components contained in the coated fertilizer. As a method for controlling the optimum dissolution rate for various crops, for example, Japanese Examined Patent Publication 60-21952.
Of using a coated fertilizer containing a hydrophilic resin described in JP-B No. 60-37074, and using a coated fertilizer containing a hydrophilic resin and a surfactant described in JP-B-60-37074, JP-B-4-69598 The technique of using the coated fertilizer to which the polyether / polyols described in 1 above are used and the like can be mentioned.

Further, considering the nutrient requirement of plants, which requires a large amount of fertilizer during the growth period as compared with that during childhood, the above-mentioned coated fertilizer technology showing an almost uniform dissolution rate within the dissolution period is sufficient. However, in recent years, studies have been actively conducted on a slow-release coated fertilizer having an initial dissolution suppressing function, that is, a coated fertilizer showing a sigmoid-type component elution. For example, an initial dissolution suppressing coated fertilizer using a multi-layer coating described in JP-B-5-29634, JP-A-6-87684.
Initial dissolution inhibiting type coated fertilizer using the method of adding a sugar polymer described in JP-A 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. An initial dissolution suppressing type coated fertilizer using a coating consisting of

With these coated fertilizers exhibiting sigmoid-type component elution, high-performance fertilizers having higher utilization efficiency of fertilizing components have been realized. However, these initial dissolution suppressing type coated fertilizers are not sufficient, and (1) the multilayer coating technique described in Japanese Patent Publication No. 5-29634 discloses a ratio of the second layer (outer layer) to the first layer (inner layer). However, if the ratio is too high, the full-scale elution in the latter half of the period cannot be remarkably exhibited. On the contrary, if the ratio is too low, the thickness of the second layer film itself becomes extremely thin, which causes quality variations. And the industrial productivity is low due to the multilayer coating. (2) The elution control technique of adding a sugar polymer described in JP-A-6-87684 is a drying treatment of the sugar polymer. Is insufficient or the sugar polymer is poorly dispersed in the coating solution, there are industrial problems such as extremely poor elution accuracy, and (3) described in JP-A-4-202078. , Alkali soluble with the first layer added with alkaline substance The elution control technology consisting of the second layer added with the substance cannot exert its sufficient effect unless the coating layer part weight in the total weight is 10% by weight or more, and the quality as a fertilizer is deteriorated, There is a problem that the industrial productivity is low because of the coating.

Further, Japanese Patent Publication No. 4-69598 discloses that
A coating technique in which a polyether polyol is dispersed is disclosed. As described on page 3 of the publication, the polyether polyol used in the present invention is a "polyethylene oxide and polypropylene oxide" having both OH groups at both ends. , Or at least 2 or more O in one molecule
It is a "complicated compound in which a polyalkylene oxide terminal group having an H group is combined with other functional groups and a plurality of molecules".

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

[0008]

DISCLOSURE OF THE INVENTION The present invention provides a coated granular fertilizer capable of sustaining a fertilizing effect for a long period of time and exhibiting the elution of a fertilizing component according to the growth of plants, that is, an initial fertilizer after fertilization. The sigmoid elution type, so-called initial elution suppression type coated granular fertilizer that suppresses the elution of active ingredients and shows the main elution in the latter period when the growth of plants is remarkable, using a single layer coating with high industrial productivity, and elution quality The purpose of the present invention is to provide a high-quality fertilizing ingredient with less variation.

[0009]

Means for Solving the Problems The inventors of the present invention have made earnest studies on the problems of the prior art as described above, and as a result, by using polyalkylene glycol having a specific structure as an elution control agent, a single layer coating is sufficient. It was discovered that it showed a good initial dissolution suppressing effect, and that it can exhibit full-scale dissolution thereafter.
The present invention has been reached. That is, the present invention relates to granular fertilizer 10
A coated granular fertilizer characterized in that 0 part by weight is coated with 2 to 20 parts by weight of a resin containing a polyalkylene glycol whose main chain end is a lower alkyl ether having 1 to 4 carbon atoms, and its preferable As an embodiment, the resin is a coated granular fertilizer characterized by being an olefin polymer, and further, the lower alkyl ether is a coated granular fertilizer characterized by being methyl ether.

The sigmoid type elution standard referred to in the present invention is D80, where the number of days showing 80% elution of fertilizer components in elution at 25 ° C. is D80 (hereinafter, this D80 is referred to as "elution type"). That is, the elution rate in one-fourth of the days is 12% or less. In other words, coated fertilizers that show linear elution show 20% elution in the first quarter of the eluate type, and the remaining three quarters.
Although 60% of the elution is shown in the period of, the sigmoidal elution is 12 in the first quarter of the elution type.
% Of the elution, and 68% or more of the elution in the remaining three quarters. More preferable sigmoid-type elution shows 10% or less of elution in the initial quarter period and 70% or more of elution type in the remaining three-quarter period. . Those exhibiting an elution of more than 12% in the initial quarter period are difficult to call sigmoid type and are not preferable.

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

The details will be described below. (1) Polyalkylene glycol whose main chain end is a lower alkyl ether The polyalkylene glycol whose main chain end is a lower alkyl ether used in the present invention is a compound represented by the following general formula. R-O- in _{(CHR'-CH 2 -O) n} -H ( wherein, R is an alkyl group having 1 to 4 carbon atoms; R 'is hydrogen, or 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, and examples thereof include methyl ether, ethyl ether, propyl ether, isopropyl ether, butyl ether, n-butyl ether, isobutyl ether,
It is t-butyl ether. The alkyl ether may be one kind or a plurality of the alkyl ethers described above. In the structure in which R is hydrogen and the both ends are OH groups, and the alkyl ether having 5 or more carbon atoms, the initial suppression effect, which is a feature of the present invention, is insufficient. Of these alkyl ethers, methyl ether is preferred.

The polyalkylene glycol is at least one selected from 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 polyalkylene glycol which is a lower alkyl ether is preferably 200 to 500,000, more preferably 300 to 100,000, and particularly preferably 400 to 20,000. Molecular weight is 200
In the following, the elution control becomes insufficient due to the polyalkylene glycol being dissipated from the film to the outside during the elution control period, and when the molecular weight is 500,000 or more, the effect of the main chain terminal becomes small. Not enough effect.

(2) Resin The resin used in the present invention is preferably a thermoplastic resin, such as 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- (meth) acrylic acid alkyl copolymer, ethylene-α-olefin- (meth) acrylic acid alkyl copolymer, propylene homopolymer, propylene-ethylene copolymer Polymers, propylene-α-olefin copolymers, polyolefin resins such as polybutene, polystyrene, HIP
Styrene-based resins such as S, AS, ABS and chlorine-containing resins such as vinylidene chloride can be used. These resins may be used alone or in combination of two or more,
You may use together a suitable compatibilizer. Among these, 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- ( Ethylene polymers such as alkyl (meth) acrylate copolymers and ethylene-α-olefin-alkyl (meth) acrylate copolymers, or a mixture of two or more of these ethylene polymers are preferable.

The density of polyethylene represented by ethylene homopolymer and ethylene-α-olefin copolymer is 0.
Preferably 91~0.97g / cm ^3, more preferably from 0.91~0.95g / cm ^3. Although the production method is not limited, for example, those polymerized by the high pressure method, α- by the solution method
Those copolymerized with an olefin and those copolymerized with an α-olefin by a low pressure method can also be preferably used. MI of these polyethylenes is 0.1 to 100 g / 10 min (19
0 ° C., 2.16 kg load) is preferable, and 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- (meth) acrylic acid alkyl copolymer,
The functional group content of the functional group-containing ethylene copolymer such as ethylene-α-olefin- (meth) acrylate copolymer is preferably less than 50% by weight, more preferably 10% by weight or less. When the functional group content is 50% by weight or more, the effect of suppressing the initial elution becomes low. These functional group-containing ethylene-based 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. MI of these functional group-containing ethylene-based copolymers is 0.1 to 100 g / 10 minutes (190 ° C,
2.16 kg load) is preferable, and more preferably,
0.5-60 / 10 minutes (190 ° C, 2.16kg load)
It is.

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

The presence state of the polyalkylene glycol in the resin is determined by the compatibility between the polyalkylene glycol and the resin, but the structure and molecular weight of the polyalkylene glycol, and the structure and molecular weight of the resin are properly determined. May be combined to dissolve to an inseparable state,
It may be finely dispersed to the micron order. The weight ratio of the resin to the polyalkylene glycol whose main chain terminal is a lower alkyl ether having 1 to 4 carbon atoms is preferably 0.05 to 99.95 to 10:90, and more preferably 0.1 to 99.9. 7:93, particularly preferably 0.15: 99.85-5: 95. If the weight ratio is less than 0.05: 99.95, the effect of the above polyalkylene glycol does not appear, and it becomes a coated fertilizer with an extremely slow elution, and if it 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 a suppressing effect.

The resin used in the present invention may be compounded with a spherical and / or plate-like filler. The size of the filler is preferably 0.1 to 50 μm, more preferably 0.2 to 30 μm. If it exceeds 50 μm, many coating defects tend to occur. As the 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 powder, crotylidene 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, and may be subjected to a sieve treatment or the like in order to improve the uniformity of coating so that the particle diameters are made uniform. You can use it. The mixing ratio of the filler is 60% by weight of the filler with respect to the total weight of the coating.
The following is preferable, and when the filler exceeds 60% by weight, a sufficient effect of suppressing initial elution cannot be obtained. Even when compounding with a filler is performed, the coating is preferably 2 to 20 parts by weight with respect to 100 parts by weight of the granular fertilizer.

That is, the resin and the main chain end have 1 to 1 carbon atoms.
The composition ratio of the polyalkylene glycol, which is a lower alkyl ether of 4, and the filler is 36 to 99.95, respectively.
% By weight, 10.00 to 0.02% by weight, 60 to 0% by weight
Will be preferred. The method of forming a coating of the present invention includes
There is no particular limitation, the jet method in which the coating material is supplied with the solvent to the fertilizer flowing in the jet tower and dried with hot air, and the fertilizer rolling in the rolling drum is supplied with the coating material with the solvent and dried with hot air. It is possible to use a rolling system for rotating, a fertilizer rolling in a rotary pan, a rotary pan system in which a coating material is supplied together with a solvent and dried with hot air, and a combination thereof, such as a jet pan system. The spray nozzle for supplying the coating material together with the solvent is not particularly limited, and a one-liquid type nozzle, a gas-assisted two-liquid type nozzle, 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)
A double salt containing one or more components selected from ammoniacal nitrogen, nitrate nitrogen, phosphoric acid and potassium, for example, phosphorus nitrate ammonium salt, ammonium carbonate ammonium salt, NK chemical, ammonium sulfate, ammonium chloride salt, ammonium chloride salt, potassium carbonate salt, nitric acid salt. Inorganic fertilizers (chemical fertilizers) such as soda, ammonium phosphate, potassium phosphate, potassium phosphate, lime phosphate, etc. (c) Magnesium salt, iron salt, molybdenum salt, manganese salt, copper salt, zinc salt, and A material to which a trace element such as borate is added can be used. These are (a), (b), (c)
You may mix 2 or more types chosen from. The shape of the granular fertilizer may be spherical, angular, or cylindrical, but spherical is preferable in order to prevent coating defects. Further, the size thereof is preferably 0.5 to 10 mm diameter, and if it is less than 0.5 mm diameter or exceeds 10 mm diameter, there may be a problem in handling during fertilization.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The fertilizer, resin, polyalkylene glycol and filler used in the following examples are as follows. [Resin A] MI is 7.0 g / 10 minutes and density is 0.922.
g / cm ³ high-pressure low-density polyethylene (Ace Polyethylene M2270, manufactured by Asahi Kasei) [Resin B] MI 2.5 g / 10 min, vinyl acetate content 19% by weight ethylene-vinyl acetate copolymer (Eva Flex 460, manufactured by Mitsui DuPont Chemical Co., Ltd. [PEG-A] Molecular weight 4,000 with one end methylated
0 polyethylene glycol (UNIOX M400
No. 0, manufactured by NOF CORPORATION) [PEG-B] Molecular weight 2,000 with one end methylated
0 polyethylene glycol (Uniox M200
0, manufactured by NOF CORPORATION) [PEG-C] 4,000 molecular weight with OH groups at both ends
Polyethylene glycol (PEG # 4000, manufactured by NOF CORPORATION) [PEG-D] Polyethylene glycol having lauryl ether at one end (NONION K-230, manufactured by NOF CORPORATION) [Talc] NK talc (manufactured by Wandoh Industrial Co., Ltd.) [Fertilizer A] Advanced Chemical Fertilizer 15-15-15, Phosphorus Ankali (5 mesh sieve pass, and 7 mesh sieve on to have uniform particle size) [Fertilizer B] Chemical fertilizer 2-0-41, Sulfuric acid-based fertilizer (5 mesh) Sieve pass and 7 mesh sieve on which the particle size is uniform) [Fertilizer C] Chemical fertilizer 46-0-0, urea (5 mesh sieve pass and 7 mesh screen on and the particle size is uniform)

The abbreviations of fertilizer components used in the elution evaluation and the analytical methods 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] up to a predetermined date The accumulated value of the amount of TN dissolved in water was divided by the total TN content in the coated fertilizer and multiplied by 100. [UN] Urea nitrogen (converted as N), dimethylaminobenzaldehyde method [UN dissolution rate] The integrated value of the amount of UN dissolved in water up to a predetermined date is divided by the total UN content in the coated fertilizer and multiplied by 100 [WK] Water-soluble potassium (calculated as K ₂ O), flame photometric method [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 phosphorous nitrate Akari, TN was used in Example 4
In Comparative Example 6, WK was used as the scale for the elution evaluation because the fertilizer B mainly containing potassium was evaluated, and in Example 5 and Comparative Example 7, the fertilizer C mainly containing urea was evaluated as UN, respectively.

[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 raw materials for coating. Resin A and PE
G-A is the solvent tetrachloroethylene 2,800
A uniform solution was prepared by charging the solution in ml, heating it to 130 ° C. and holding it for 1 hour, and further mixing talc with stirring to prepare a coating solution. (2) Coating of fertilizer 3,000 g of fertilizer A was charged into the jet type coating apparatus described in Japanese Patent Publication No. 60-37074, and the bed temperature was set to 70.
The fertilizer was coated by supplying the above coating solution for 10 minutes while elevating the temperature to 0 ° C and evaporating tetrachloroethylene with hot air at 110 ° C to maintain the bed temperature at 70 ° C.
The obtained coated fertilizer was 3,235 g. (3) Evaluation of component elution of coated fertilizer The obtained coated fertilizer (3,235 g) was divided into 10 g samples three times, and 200 g was collected for each 10 g sample.
After adding ml of pure water, the elution evaluation in water was performed in an incubator at 25 ° C. The elution type for TN of this coated fertilizer is 73 days, an initial quarter period 18
The dissolution rate on the day was 2.7%, and a coated fertilizer showing sigmoidal dissolution was obtained.

[0026]

[Example 2] 112.8 g of Resin A as a raw material for coating
Then, the fertilizer was coated in the same manner as in Example 1 except that PEG-B was 7.2 g and talc was 120 g. The obtained coated fertilizer was 3,238 g. When the elution evaluation was performed in the same manner as in Example 1, the elution type for TN was 70 days, the elution rate on the 18th day, which is the first quarter, was 3.5%, and the sigmoid type was found. A coated fertilizer having an elution of was obtained.

[0027]

Comparative Example 1 112.8 g of Resin A as a raw material for coating
Then, the fertilizer was coated in the same manner as in Example 1 except that PEG-C was 7.2 g and talc was 120 g. The obtained coated fertilizer was 3,236 g. When the elution evaluation was performed by the same method as in Example 1, the elution type for TN was 69 days, and the elution rate on the 17th day, which is the initial quarter, was 25.2%, indicating that non-sigmoid A general coated fertilizer with mold elution was obtained.

[0028]

[Comparative Example 2] 114.0 g of Resin A as a raw material for coating
Then, 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 was 3,236 g. When the elution evaluation was performed by the same method 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, was 38.6%, indicating that non-sigmoid A general coated fertilizer with mold elution was obtained.

[0029]

Example 3 116.4 g of Resin A as a raw material for coating
Then, 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 was 3,237 g. When the elution evaluation was carried out in the same manner as in Example 1, the elution type for TN was 140 days, which was an initial quarter period.
The dissolution rate on the day was 4.7%, and a coated fertilizer showing a sigmoidal dissolution was obtained.

[0030]

Comparative Example 3 106.8 g of Resin A as a raw material for coating
Then, the fertilizer was coated in the same manner as in Example 1 except that 13.2 g of PEG-A and 120 g of talc were used.
The obtained coated fertilizer was 3,235 g. When the elution evaluation was performed in the same manner as in Example 1, the elution type for TN was 57 days, which was an initial quarter period.
The elution rate on the day was 29.0%, and a non-sigmoid elution general coated fertilizer was obtained.

[0031]

Comparative Example 4 120.0 g of Resin A as a raw material for coating
Then, the fertilizer was coated in the same manner as in Example 1 except that the amount of talc was changed to 120 g. The obtained coated fertilizer is 3,23
6 g. When the elution evaluation was carried out in the same manner as in Example 1, the elution type of TN was 408 days, and the elution rate on the 102nd day, which is a period of the initial quarter, was 17.1.
%, The elution was extremely slow, and a non-sigmoidal elution coated fertilizer was obtained.

[0032]

Comparative Example 5 64.0 g of Resin A as a raw material for coating,
The fertilizer was coated in the same manner as in Example 1 except that the amount of Resin B was 56.0 g and the amount of talc was 120 g. The obtained coated fertilizer was 3,238 g. When the elution evaluation was performed 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 is the first quarter, was 26.9%, indicating that non-sigmoid 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 was 3,235 g. When the elution evaluation was carried out in the same manner as in Example 1 except that the evaluation was the WK elution rate, the elution type for WK was 68 days, and the elution rate for 17 days, which is the initial quarter, was 2 days. .1%,
A coated fertilizer having a sigmoidal elution was obtained.

[0034]

[Comparative Example 5] 114.0 g of Resin A as a raw material for coating
Then, 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 was 3,236 g. When the elution evaluation was carried out 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 is the first quarter, was 17.2%, indicating that non-sigmoid A general coated fertilizer with mold elution was obtained.

[0035]

Example 5 Fertilizer C was used instead of Fertilizer A, and 238.8 g of Resin A and 1.2 of PEG-A were used as raw materials for coating.
Fertilizer was coated in the same manner as in Example 1 except that the amount was changed to g. The obtained coated fertilizer was 3,232 g. Since the fertilizer C is a urea-based fertilizer, the elution evaluation was performed by UN. As a result, the elution type of UN for this coated fertilizer was 92 days, and the elution rate on the 23rd day, which is the first quarter, was 4.7%, indicating that the coated fertilizer showing sigmoidal elution was Was obtained.

[0036]

Comparative Example 7 238.8 g of Resin A as a raw material for coating
Then, 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 was 3,233 g. When the elution evaluation was performed by the same method as in Example 5, the elution type of UN was 86 days, the elution rate on the 22nd day, which is the period of the initial quarter, was 28.1%, and it was a non-sigmoid. 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]

Industrial Applicability According to the present invention, it is possible to obtain a coated granular fertilizer exhibiting the 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.
Also, environmental protection 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 number of elapsed days in Example 3 and Comparative Examples 3 to 5.

FIG. 3 is a diagram showing the WK elution rate for each number of elapsed days in Example 4 and Comparative Example 6.

FIG. 4 is a diagram showing the UN elution rate for each number of elapsed days in Example 5 and Comparative Example 7.

Claims (3)

[Claims] 1. Coated granules, characterized in that 100 parts by weight of granular fertilizer is coated with 2 to 20 parts by weight of a resin containing a polyalkylene glycol whose main chain end is a lower alkyl ether having 1 to 4 carbon atoms. fertilizer. 2. The coated granular fertilizer according to claim 1, wherein the resin is an olefin polymer. 3. The coated granular fertilizer according to claim 1, wherein the lower alkyl ether is methyl ether.