JPH0529634B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of Industrial Application) The present invention relates to a coated granular fertilizer that is capable of supplying nutrients at an appropriate time according to the nutrient requirements of crops, in a fertilizer effect-adjustable fertilizer with different durations of fertilizer effect. (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. 3295950, Japanese Patent Publication No. 40-28927,
Various materials have been proposed in Japanese Patent Publication No. 44-28457, British Patent No. 815829, Japanese Patent Publication No. 37-15832, Japanese Patent Publication No. 42-13681, etc., but none of them have the ability to adjust the elution rate of fertilizer components. has been shown to be difficult. For these, Special Publication No. 60-21952, Special Publication No. 60
-3040 describes a coating method in which granular fertilizer is coated with a coating material mainly composed of polyolefin, 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 the case of fertilizer, expressing the fertilizer effect according to the growth of crops means that nutrients are supplied according to the needs of the crops during the period of crop production in the environment where the crops are produced. Therefore, in the case of coated granular fertilizers, the component elution pattern has been pointed out as an important factor. In coated granular fertilizers that have been proposed in the past, the component elution rate for each predetermined period (hereinafter referred to as the differential elution rate) is high in the first half of the total elution period, and gradually decreases in the second half, depending on the nutrient demand pattern of crops. A large difference is likely to occur. especially,
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. We investigated coating materials and coating methods.
This led to the completion of the present invention. That is, the present invention provides that 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, A first coating material that is one or more substances selected from oils and fats and modified products thereof, and a second coating material that is at least one substance selected from resins that are soluble or swellable in water. A solution of the above-mentioned mixture is sprayed onto the granular fertilizer, and at the same time, a high-speed hot air stream is applied to that position to instantly dry and coat the granular fertilizer.
This product provides a coated granular fertilizer that can supply nutrients according to the nutrient requirements of crops, which is obtained by spraying a solution of coating material and simultaneously applying a high-speed hot air stream to the area to instantly dry and coat the area. be. In the present invention, if necessary, an elution regulator, a 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 the olefin polymer refers to polyethylene,
Polypropylene, ethylene/propylene copolymer, polybutene, butene/ethylene copolymer, butene/propylene copolymer, polystyrene, etc. Copolymers containing olefins include ethylene/propylene copolymer, etc.
Vinyl acetate copolymer, ethylene/acrylic acid copolymer, ethylene/acrylic acid ester copolymer,
Ethylene/methacrylic acid copolymer, ethylene/
These include methacrylic acid ester copolymers, ethylene/carbon monoxide copolymers, ethylene/vinyl acetate/carbon monoxide copolymers, etc. Copolymers containing vinylidene chloride include vinylidene chloride/vinyl chloride copolymers. The diene polymers include butadiene polymers, isoprene polymers, chloroprene polymers,
Butadiene/styrene copolymer, EPDM polymer,
Styrene/isoprene copolymer, etc. Waxes include beeswax, wood wax, paraffin, etc. Natural resins include natural rubber, rosin, etc.
Fats and oils and modified products thereof include hydrogenated oils, solid fatty acids, metal salts, and the like. The second coating material is a substance that is soluble or swellable in water, such as polyether polyols, such as ethylene oxide polymer, propylene oxide polymer, ethylene oxide-propylene oxide copolymer, and highly water-absorbing and swelling substances. Examples include isobutylene polymers, acrylic acid-vinyl alcohol copolymers, polyethylene oxide modified resins, sodium acrylate polymers, starch graft polymers, and starches. The weight percentage of the coating material of the present invention relative to the coated granules, that is, the coverage rate is 2 to 20% in the first coating layer.
(weight) is a preferable range. The coverage rate of the second coating layer 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 10.0% (weight) of the first coating material component.
It is used in a mixed range of In addition, as the third coating material components that can be mixed as necessary, a surfactant as an elution regulator, talc as an insoluble filler, calcium carbonate, diatomaceous earth, kaolin, bentonite, silica metal oxide, etc. may be used. I can do it. It is an essential requirement that these mixtures be uniformly dispersed; if they are non-uniform, some of the fine particles will be concentrated and the continuous phase of the coating material will be impaired, 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) The location and method suitable for creating the granular fertilizer of the present invention will be shown. Figure 1 shows a suitable example of the device, 1 is a jet tower with a tower diameter of 200 mm, a height of 180 mm, and an air jet diameter of 42 mm.
It has a fertilizer inlet 2 and an exhaust gas outlet 3. The jet air is sent from the blower 10, passes through the orifice flow meter 9 and the heat exchanger 8, and reaches the jet tower.The flow rate is controlled by the flow meter, 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 in a spray form 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, the system being sufficiently insulated to maintain the temperature. Once the specified coating liquid has been supplied, stop the pump and then stop the blower. The coated fertilizer is taken out from the outlet 7. 6 is a valve. In FIG. 1, T1,
T2 and T3 are thermometers, and SL is steam. In addition, in all of the present examples, the following basic conditions were maintained and the coating with granular fertilizer was performed. Liquid nozzle: Opening 0.8mm full control type Hot air volume: 4m ² /min Hot air temperature: 100℃ Fertilizer type: 5-7mesh Phosphorus Nitrate Fertilizer input amount: 5Kg Coating liquid concentration: Solid content 5% by weight Coating liquid supply amount; 0.5Kg/min Covering time: 10 minutes Coverage rate (relative to fertilizer): 5.5% by weight (surfactant added) Solvent: Tetrachlorethylene Next, a composition example and its nitrogen elution amount are shown. By the above manufacturing method, coated phosphorus nitrate coatings having various coating compositions shown in Table 1 were manufactured, and the nitrogen elution amount of each was tested. The results are also listed in Table 1. No. 1 in Table 1 is a comparative example. The nitrogen elution patterns of No. 1 and No. 2 in Table 1 are shown in FIG. In Table 1, nitrogen elution was performed in water at 25°C.

【table】

[Table] (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 its component elution pattern minimizes initial elution and subsequent elution. It is a type of coated granular fertilizer that is completely different from conventional fertilizers in that it can be applied quickly and is suitable for the absorption of nutrients by ordinary crops. 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 the drawing]

Figure 1 is a front view showing an example of an apparatus suitable for manufacturing the product of the present invention, and Figure 2 is No. 1 and No. 2 in Table 1.
2 is a graph showing the nitrogen elution pattern of . 1... Jet tower, 2... Fertilizer inlet, 3... Exhaust gas outlet, 4... Fluid nozzle, 5... Pump, 6
...Valve, 7...Outlet port, 8...Heat exchanger, 9
... Orifice flow meter, 10 ... Blower, 11
...Liquid tank, T1, T2, T3...Thermometer,
SL...Steam.

Claims (1)

[Claims] 1. The surface of the granular fertilizer contains an olefin polymer, an olefin-containing copolymer, a vinylidene chloride polymer,
a first coating material that is one or more substances selected from copolymers containing vinylidene chloride, diene polymers, waxes, petroleum resins, natural resins, oils and fats, and modified products thereof; It is coated with a mixture with a second coating material which is at least one substance selected from resins that dissolve or swell as an essential coating material, and the surface thereof is further coated with the above-mentioned first coating material as an essential coating material. A coated granular fertilizer characterized by: 2. The coated granular fertilizer according to claim 1, 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).