JPH02275792A - Coated granular fertilizer - Google Patents

Abstract

PURPOSE:To enable to supply a fertilizer component to crops at a suitable time by coating the surface of a granular fertilizer with two kinds of specific coating materials. CONSTITUTION:A coating solution containing a mixture comprising 20 to 99.9wt.% of one kind or more of the first coating materials selected from olefinic (co)polymers, vinylidene chloride (co)polymers, dienic polymers, waxes, petroleum resins, natural resins, fats, oils and modified products thereof and 0.1 to 10wt.% of one kind or more of the second coating materials selected from water-soluble or swellable resins (e.g. polyethylene oxide) is sprayed into a jetting tower 1 from a liquid nozzle 4. A granular fertilizer is also charged in the jetting tower 1 from a fertilizer-charging opening 2. The mixture in the tower 1 is fluidized with air supplied from a blower 10 through a heat exchanger 8 to coat the surface of the granular fertilizer with the mixture, followed by taking out the coated fertilizer from a discharging opening 7.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is an adjustable fertilizer with different durations of fertilizing effect. Regarding fertilizers.

(Prior Art) Conventionally, various fertilizers with adjustable fertilizer effects have been developed for the purpose of expressing fertilizer effects according to the growth of crops, and in particular, coated granular fertilizers in which the surface of granular fertilizers is covered with a coating material. Many have been disclosed and are commercially available. For example, U.S. Patent No. 3,295,950
No., Special Publication No. 1972-28927, Special Publication No. 1977-2845
No. 7, British Patent No. 815829, Special Publication No. 37-158
Although various materials have been proposed in Japanese Patent Publication No. 32 and Japanese Patent Publication No. 42-13681, it has been shown that it is difficult to control the elution rate of fertilizer components in all of them.

For these, Special Publication No. 60-21952, Special Publication No. 60-21952,
No. 3040 describes a coating method in which granular fertilizer is coated with a coating material containing polyolefin as a main component, by spraying a solution of the coating material onto the granular fertilizer and simultaneously drying it with a stream of hot air.The characteristics of this technology include: It has been shown that the elution rate can be adjusted and is in practical use.

(Problem to be solved by the invention) In a fertilizer, expressing the fertilizer effect according to the growth of the crop means that nutrients are supplied according to the needs of the crop during the period of crop generation in the environment where the crop grows. Therefore, the component elution pattern has been pointed out as an important factor in coated granular fertilizers. For coated granular fertilizers that have been proposed so far, the component elution rate (hereinafter referred to as
The differential leaching rate (differential leaching rate) is high in the first half of the total leaching period and gradually decreases in the second half, which tends to cause large differences compared to the nutrient requirement pattern of crops. In particular, a decrease in the differential elution rate in the second half causes a shift in fertilizer effectiveness to subsequent crops, which is unfavorable in terms of fertilizer management. It is desirable that component elution be completed within the targeted cultivation period in a pattern that matches the nutrient requirements of the crop.

(Means for Solving the Problem) The present inventors aimed to obtain a coated granular fertilizer in which the fertilizing period can be adjusted and the elution rate is adjusted, and the elution rate is adjusted to have a component elution pattern that matches the nutrient requirements of crops. Then, they investigated coating materials and coating methods and completed the present invention.

That is, the present invention provides that the surface of the granular fertilizer contains an olefin polymer, an olefin-containing copolymer, a vinylidene chloride polymer, a vinylidene chloride-containing copolymer, a diene polymer,
A first coating material that is one or more substances selected from waxes, petroleum resins, natural resins, oils and fats, and modified products thereof; and at least one substance selected from water-soluble or swollen resins. An effect-adjustable fertilizer coated with a mixture of a substance and a second coating material as an essential coating material,
Coated granules that can supply nutrients in accordance with the nutrient requirements of crops obtained by spraying a solution of the coating material onto granular fertilizers and simultaneously applying a high-speed hot air stream to that location to instantly dry it and covering it. It's fertilizer.

Furthermore, the present invention provides the nutrient requirements for crops that can be obtained by spraying the solution of the first coating material onto the surface of the coated granular fertilizer and simultaneously applying a high-speed hot air flow to that position to instantly dry and coat the surface of the coated granular fertilizer. It is a coated granular fertilizer that can supply nutrients according to the conditions.

In the present invention, if necessary, an elution regulator, filler, etc. can be uniformly dispersed and used as a third coating material in the first coating layer and/or the second coating layer.

The first coating material in the present invention is as described above, but
Olefin polymers include polyethylene, polypropylene, ethylene/propylene copolymer, polybutene, butene/ethylene copolymer, butene/propylene copolymer,
Polystyrene, etc., and copolymers containing olefins include ethylene/vinyl acetate copolymers, ethylene/acrylic acid copolymers, ethylene/acrylic acid ester copolymers,
Copolymers containing vinylidene chloride, such as ethylene/methacrylic acid copolymers, ethylene/methacrylic acid ester copolymers, ethylene/carbon oxide copolymers, ethylene/vinyl acetate/carbon oxide copolymers, etc. is a vinylidene chloride/vinyl chloride copolymer, and a diene polymer is a butadiene polymer, an isoprene polymer, a chloroprene polymer, a butadiene/styrene copolymer, an EPDM polymer, or a styrene/isoprene copolymer. Waxes include beeswax, wood wax, paraffin, etc., natural resins include natural rubber, rosin, etc., and fats and oils and their modified products include hydrogenated oils, solid fatty acids, metal salts, etc. It is.

The second coating material is, for example, polyethylene oxide.

The weight percentage of the coating material of the present invention relative to the coated granules, that is, the coverage rate, is preferably in the range of 2 to 20% (by weight) in the first coating layer. When there is a second coating layer, its coverage is preferably in the range of 0.5 to 5% (by weight).

In addition, the first coating material component in the first coating layer accounts for 20 to 99.9% (weight) of the entire coating material, and the second coating component accounts for 0.1 to 10% (by weight) of the first coating material component. weight) is used in the mixing range. In addition, the third type can be mixed as necessary.
The coating material components include a surfactant as an elution regulator,
Talc, calcium carbonate, metal oxides, etc. can be used as insoluble fillers. It is essential that these mixtures are uniformly dispersed; if they are non-uniform,
Some of the particles become lopsided, damaging the continuous phase of the coating material and causing the coating to lose its effectiveness.

In the present invention, in the first coating or the second coating, a solution in which the coating material is dissolved or dispersed in a solvent such as chlorinated hydrocarbons is maintained at high temperature, and is added to the granular fertilizer in the form of a spray, and at the same time, it is sprayed at that position at high speed. A coated granular fertilizer can be obtained by instantly drying and coating the fertilizer by applying a stream of hot air.

(Example) An apparatus and method suitable for producing the granular fertilizer of the present invention will be shown.

Figure 1 shows a suitable example of the apparatus, in which 1 is a jet column with a column diameter of 2
00mm, height 1800mm, air jet diameter is 42mm,
It has a fertilizer inlet 2 and an exhaust gas outlet 3. The jet air is sent from the blower IO and reaches the jet tower via the orifice flow meter 9 and the heat exchanger 8, but the flow rate is controlled by the flow meter and the temperature is controlled by the heat exchanger, and the exhaust gas is sent from the exhaust gas outlet 3 to the outside of the tower. guided by. The granular fertilizer to be subjected to the coating treatment is introduced from the fertilizer inlet 2 while passing a predetermined amount of hot air to form a jet stream.

In the coating process, after the temperature of the coating particles reaches a predetermined temperature, the coating liquid is sprayed toward the jet stream through the liquid nozzle 4. The coating liquid is prepared by putting a predetermined amount of coating material and a solvent into a liquid tank 11, and stirring the mixture near the boiling point of the solvent. The supply of coating liquid is sent to the nozzle by a pump 5,
This system should have sufficient insulation to maintain the temperature.

Once the prescribed coating liquid has been supplied, the pump is stopped and then the blower is stopped. The coated fertilizer is removed from the extraction lower. 6 is a valve. In Figure 1, T1, T
2. T3 is a thermometer and SL is steam. In addition, in each of the present Examples, the coating with granular fertilizer was performed while maintaining the following basic conditions.

Liquid nozzle; Opening Q, 8mm full control hot air volume; 4 holes/
min Hot air temperature; 100°C Fertilizer seed 1; 5-7 mesh phosphorus and ankari fertilizer input amount;
5 kg Coating liquid concentration: Solid content 5 times % Coating liquid supply 11: 0, 5 kg/min Coating time: 10 minutes Coverage rate (relative to fertilizer): 5.5% by weight (However, surfactant bone is added) Solvent ; Tetrachlorethylene Next, a composition example and its nitrogen elution amount are shown.

By the above manufacturing method, coated phosphorus sulfate Azakari with various coating compositions shown in Tables 1 and 2 were manufactured, and the nitrogen elution amount of each was tested, and the results are also listed in Tables 1 and 2. did. N in Table 1.

1, No. 4, No. 6, and Nα1 in Table 2 are comparative examples.

The nitrogen elution patterns of Nα1, Nα2, and N063 in Table 1 are shown in Figure 2.
The nitrogen elution pattern of No. 2 is shown in FIG. FIG. 4 shows an elution pattern in which the number of days to reach 80% of the 80% release rate is set to 100 days. In addition, in Tables 1 and 2, nitrogen elution was performed in water at 25°C.

(Effects of the Invention) The coated granular fertilizer according to the present invention allows the duration of fertilizer effect to be adjusted with a small coating rate, and the component elution pattern is
It is more linear than conventional over the entire elution period and is thus preferred for normal crop nutrient uptake. Furthermore, since the amount of components remaining after the cultivation period of crops can be reduced, it has the effect of facilitating fertilizer management.

[Brief explanation of drawings]

Fig. 1 is a front view showing an example of an apparatus suitable for manufacturing the product of the present invention, and Fig. 2 is a front view showing an example of an apparatus suitable for manufacturing the product of the present invention.
3 is a graph showing the nitrogen elution pattern of Nα1 and No. 2 in Table 2. FIG. 4 is a graph showing the nitrogen elution pattern of No. 1, No. 2 and No. 3 in Table 1. The number of days to reach 80% nitrogen elution rate is 1.
It is a graph showing the elution pattern adjusted to day 00. 5... Pump 6... Valve 7... Outlet port 8... Heat exchanger 9... Orifice flow meter 10... Blower II
...Liquid tanks T1, T2, T3...Thermometer, SL...Steamed jet tower 2...Fertilizer inlet 3...Exhaust gas outlet 4...Fluid nozzle 2

Claims (3)

[Claims] (1) The surface of the granular fertilizer is made of olefin polymers, copolymers containing olefins, vinylidene chloride polymers, copolymers containing vinylidene chloride, diene polymers, waxes, petroleum resins, natural resins, oils and fats. A mixture of a first coating material that is one or more substances selected from modified substances and a second coating material that is at least one substance selected from resins that are soluble or swellable in water. A coated granular fertilizer characterized by being coated as an essential coating material. (2) The surface of the granular fertilizer contains olefin polymers, olefin-containing copolymers, vinylidene chloride polymers, vinylidene chloride-containing copolymers, diene polymers, waxes, petroleum resins, natural resins, oils and fats, and A mixture of a first coating material that is one or more substances selected from modified substances and a second coating material that is at least one substance selected from resins that are soluble or swellable in water. A coated granular fertilizer characterized in that the fertilizer is coated as an essential coating material, and the surface thereof is further coated with the above-mentioned first coating material as an essential coating material. (3) The coated granular fertilizer according to claim 1 or 2, wherein the ratio of the second coating material to the first coating material in the first coating layer is 0.1 to 10.0% (by weight).