JPS6340789A - Granular fertilizer coated with decomposable coating and manufacture - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a granular fertilizer coated with a degradable coating and a method for producing the same. More specifically, the present invention relates to the fertilizer coated with a degradable film containing poly-3-hydroxy-3-alkylpropionic acid as an essential resin component, and to the method for producing the fertilizer.

The coating according to the present invention is decomposed by soil microorganisms and does not ultimately remain in the soil.
Various auxiliaries or agents can be added to control the leaching of the granular fertilizer.

[Conventional technology]

Various studies have been conducted in order to match the elution of fertilizing ingredients in granular fertilizers applied to soil with the requirements associated with crop growth, or to prevent moisture absorption or caking during the distribution process of granular fertilizers. One such method is to coat the surface of granular fertilizer with a high molecular weight polymer. This coating can be either thermoset or thermoplastic. However, coating with such a high molecular weight polymer also has various problems as described below.

Examples of methods using thermosetting resins include styrenated alkyd resins and phenolic resins (British Patent No. 954.5).
55), fatty oil-modified alkyd resins, fatty oil dicyclopentadiene copolymers, diisocyanate-modified fatty oil polymers (Japanese Patent Publication No. 40-28,927), or phenol resins (Japanese Patent Publication No. 44-28,457) are shown. ing. Further, as a method of using a thermoplastic resin, for example, a copolymer (UK Patent No. 815,829) and vinyl acetate emulsion polymerization solution (Japanese Patent Publication No. 37-15.832).

As a problem when using a high molecular weight polymer, especially a thermoplastic resin solution or its emulsion polymer solution, as a coating material, Japanese Patent Publication No. 42-13, 881 describes coating the surface of granules with a liquid resin or a stringable resin. Due to the stringiness of the resin, the particles adhere to each other and form blocks at a length where only a few percent of the resin is coated, and it is difficult to coat the particles evenly and thickly without forming individual particles. has been done.

JP-A-50-99,858, JP-A-51-75,67
4, JP-A-53-98.265 relates to a coating method for granular fertilizer invented by the present inventors, but these publications describe blocking in the coating process by selecting the properties of the resin solution and drying conditions. A method has been shown that allows for efficient coating in one step without causing any problems.

JP-A-50-99,858 discloses that when granular fertilizer is coated with a coating material mainly composed of polyolefin, a solution of the coating material is sprayed onto the granular fertilizer, and at the same time the granular fertilizer is coated, it is dried with a high-speed hot air stream. A method of coating is shown. The features of this technology are: 1) It can be coated uniformly with an extremely thin coating, and 2) A surfactant is dispersed in the coating as an elution control agent to control the elution rate by tI! Im at the point where I can.

JP-A-51-75,874 discloses that polyvinylidene chloride resin and ethylene/vinyl acetate copolymer containing 5% by weight or less of vinyl acetate can uniformly cover granular fertilizer as an extremely thin film, similar to polyolefin resin. Disclosed.

Japanese Patent Publication No. 80-37,074 discloses that coating with a polyolefin resin, an ethylene vinyl acetate copolymer, and a surfactant can provide highly stable elution control.

Furthermore, JP 1986-3.040 and JP 55-1, 8
72 shows that by dispersing inorganic powder such as talc and sulfur into the polyolefin resin coating, the elution control function is maintained and at the same time, the disintegration and decomposition of the remaining capsules after elution is promoted. has been done.

These series of coating techniques by the present inventors are summarized,
It was put into practical use as a coated granular fertilizer coated with granular urea or chemical fertilizer, and came to be widely used as an excellent elution control fertilizer. Elution control for these fertilizers can be continuously adjusted for several hours to several years without changing the thickness of the coating, but they basically exhibit a slow-release elution pattern, and the capsules after elution are not exposed to light or oxygen. Deterioration 1: It has the property of decomposing. However, there has been a demand from related parties for the emergence of coated granular fertilizers of the slow-release type and time capsule type coated with more advanced microbially degradable materials, in which the capsules are quickly decomposed by microorganisms after release.

[Purpose of the invention]

In view of these circumstances, the inventors of the present invention developed a Slow-r that can be controlled arbitrarily and is based on microbially degradable materials.
The present invention was achieved through research on release type fertilizers and time capsule type fertilizers that do not elute until a predetermined period of time and then elute in a short period of time.

After confirming that poly(3-hydroxy-3-alkylpropionic acid), which is an essential coating material for the present invention, and especially the polymer whose alkyl group is methyl or ethyl, is an excellent microbial polymer material, In order to complete the present invention, attempts were made to coat the material by dissolving it in various solvents. In the case of the solvent solution, when it was added in the form of a spray, the coating material became sticky and the particles in the coating stuck together, making it impossible to coat a single particle. In addition, it was not possible to obtain a tough coating peculiar to polymers. As a result of trial and error, it became possible to coat a single grain with a uniform coating by the method described below, which is based on the coating method disclosed in JP-A-50-99-858 invented by the present inventors, and the present invention A method has been discovered and the invention has been completed.

In order to complete these technologies, it is necessary to find a polymer material that satisfies all of the following (1) to (2).

■ To find a strong polymer material that is easily decomposed by soil microorganisms (it is possible to develop a coating technology that uses a false material. ■ To be able to control elution of products coated with that material. ■ To be able to control elution from other materials.) A wide range of elution rate control is possible by combining with soil. ■ Elution control is possible even under conditions where soil microorganisms attack the soil.

In the early stages of these search studies, various polymeric materials were investigated and evaluated for their ability to be buried in soil and degraded by soil microorganisms.

It was found that some of these polymeric materials are subject to decomposition. Various coating processes have been investigated using these degradable materials, but most of them have not been able to provide a uniform coating process that can withstand elution control. Even if a uniform film could be coated, evaluation of the film's physical properties and water dissolution tests revealed that most of the films could not be put to practical use.

It was confirmed through an underwater dissolution test that the materials screened in this way can be further combined with other materials and used as a composite material, and the dissolution rate can be controlled over a wide range.

These materials were also tested for dissolution in soil under conditions where they were degraded by soil microorganisms.

By making composite materials, for example, if there are many polymeric materials that are non-degradable by microorganisms, the decomposition of the capsule itself in the soil could be suppressed, but this is not the case with the current Slow-r.
The present invention, which can be used as an release-type elution control fertilizer, was achieved as a result of long-term research and development.

As is clear from the above description, an object of the present invention is to provide a granular fertilizer coated with a film decomposable by soil microorganisms and a method for producing the same.

[Structure and effects of the invention]

The present invention (second invention) has the following main configurations (1) and (8) and embodiment configurations (2) to (5) or (7) to (9).

(1) A granular fertilizer coated with a degradable film containing poly-3-hydroxy-3-alkylpropionic acid as an active ingredient.

(2) The granular fertilizer according to item (1) above, wherein the alkyl group is a methyl group or an ethyl group.

(3) In addition to poly-3-hydroxy-3-alkylpropionic acid, the degradable coating is made of polyvinylidene chloride, polyolefin, rubber, ethylene/vinyl acetate copolymer, polystyrene, polymethyl methacrylate, ethylene/carbon monoxide, etc. Polymers, resins such as ethylene/vinyl acetate/carbon monoxide copolymers, ethylene/ethyl acrylate copolymers, ethylene methacrylic acid copolymers, paraffins, hydrogenated oils, solid fatty acids and their metal salts, beeswax, The granular fertilizer according to item (1) above, comprising one or more types selected from low-molecular resin substances such as wood wax petroleum resins and rosin.

(4) The degradable coating is inorganic or organic and contains poorly water-soluble or insoluble powder,
The granular 1lffl material described in item 3).

(5) The fertilizer according to item (4) above, wherein the inorganic powder is talc, clay, silica, diatomaceous earth, metal oxide, or sulfur powder, and the organic powder is starch or crotylidene diurea powder.

(6) An organic solvent solution of poly-3-hydroxy-3-alkylpropionic acid is added to a fluidized granular fertilizer in a spray form, and at the time of addition, a high-speed hot air stream is blown onto the granular fertilizer to remove the added organic solvent. A method for producing a granular fertilizer coated with a degradable film, which is characterized by instantaneously removing and drying an organic solvent in a solvent solution.

(7) In addition to poly-3-hydroxy-3-alkylpropionic acid in an organic solvent solution, polyvinylidene chloride, polyolefin, rubber, ethylene/vinyl acetate copolymer, polystyrene, polymethyl methacrylate, ethylene/
Carbon monoxide copolymer, ethylene/vinyl acetate/carbon monoxide copolymer, ethylene/ethyl acrylate copolymer, ethylene methacrylate copolymer resins, paraffin, hydrogenated oil, solid fatty acids, and their metal salts. ,
The manufacturing method according to item (6) above, wherein one or more substances selected from low-molecular resin substances such as animal wax, wood wax, petroleum resin, or rosin are dissolved and used.

(8) The manufacturing method described in item (6) or item (7) above, wherein an inorganic or organic water-soluble or insoluble powder is further mixed and dispersed in an organic solvent solution.

(8) The production method according to item (8), wherein the inorganic powder is a powder of talc, clay, silica, diatomaceous earth, metal oxide, or sulfur, and the organic powder is a powder of starch or crotylidene diurea.

The present invention uses poly-3-hydroxy-3-alkylpropionic acid (chemical structure [D]) as a soil microbially degradable polymer material for forming a degradable film. Methylpropionic acid (chemical structure (H)), poly-3-hydroxy-3-ethylpropionic acid (chemical structure [■]), and 3-hydroxy-3-merulpropionic acid and 3-hydroxy-3-
It is a copolymer with ethylpropionic acid (chemical structure [■]), and basically has the following chemical structure, but
The bonds in the copolymer (■) may be random or block.

The granular fertilizer of the present invention comprises these poly-3-hydroxy-
Even when coated with a 3-alkylpropionic acid material, a sufficient elution control function can be obtained. That is, for example, urea, which has a high deliquescent solubility, can last several tens of days, and potassium sulfate, which has small physical properties, can last several hundreds of days. If elution is to be accelerated by these single materials, the degree of acceleration can be adjusted depending on the dispersion by dispersing the surfactant in the formed film, that is, in the capsule, or by dispersing powder as a filler. However, with these methods, although it is possible to shorten the elution period more than using a single material, it is difficult to extend it.

The surfactant that can be used in the present invention may be cationic, anionic, amphoteric, or nonionic; is important. If the hydrophilicity is too strong, the particles will not be uniformly dispersed in the film and will aggregate, causing film defects. Those with strong lipophilicity do not affect the coating, but they tend to be slightly less effective in promoting elution. The HLB of these surfactants is 15 or less, preferably in the range of 11-13.

The powder as a filler used in the present invention is a poorly water-soluble or insoluble powder, and either inorganic or organic powder can be used, but the particle size is less than half the thickness of the coating, preferably less than ζ. The one is good. These fillers are uniformly dispersed within the coating, but those with poor dispersibility require treatment to improve dispersibility, such as surface treatment with silicone or the like, or use of a surfactant to make them easier to disperse. Preferred examples of these inorganic powders include talc, calcium carbonate, clay,
Examples include diatomite, silica and its salts, metal oxide sulfur, and the like. Sulfur in these inorganic powders is a material that undergoes microbial decomposition, and has the advantage of being easily decomposed in soil as a component of the composite material of the coating. On the other hand, although organic powders are inferior to inorganic ones as fillers, they are often easily decomposed by microorganisms, and soil decomposition as composite materials has advantages over sulfur, such as starch and other starchy materials. Preferred materials include slow-release nitrogen fertilizers such as clotilidage urea, which generates NH3 through microbial decomposition in materials and soil. When these powders are used as fillers, as the amount used increases, the film strength tends to decrease regardless of which powder is used.

Another method of controlling the elution of fertilizing ingredients in the present invention is to use other polymeric materials or waxes as film-forming materials. This method is particularly effective in retarding dissolution compared to the case of a single material, but it can also be accelerated depending on the selection of composite materials. These methods can be used in combination with the first method, which is the promoting effect of incorporating surfactants and fillers, and are often desirable.

Examples of poly-3-hydroxy-3-alkylpropionic acid-based materials include polyvinylidene chloride and its copolymers, polyolefin-based resins, ethylene/carbon monoxide copolymers, ethylene/vinyl acetate copolymers, and ethylene/vinyl acetate copolymers. These include vinyl acetate/carbon monoxide copolymer, ethylene/ethyl acrylate copolymer, ethylene/methacrylic acid copolymer, rubber resin, polystyrene, polymethyl methacrylate, etc. Among these, polymeric materials such as polyvinylidene chloride and its copolymers, polyolefin resins, and ethylene/carbon monoxide copolymers are preferred materials for the purpose of delaying elution.

On the other hand, ethylene and
Vinyl acetate copolymers with particularly high vinyl acetate content (40
% by weight or more) and rubber (rubber-based resins), natural rubber, polyisoprene, polybutadiene, and styrene-butadiene random copolymer.

On the other hand, preferred waxy materials to be composited include paraffin, solid fats, especially hydrogenated oils, solid fatty acids and their divalent and trivalent metal salts, beeswax, wood wax, rosin, and petroleum resins. is a material that delays elution.

According to the present invention, a coated granular fertilizer having various functions can be produced using a poly-3-hydroxy-3-alkylpropionic acid-based material as a coating material. Granular fertilizers used as core materials have a variety of ingredients, particle sizes, shapes, etc., and even when imparting the same function, the coating state must be changed depending on the type, particle size, and shape of the fertilizer. For example, The practical film thickness of the coated granular fertilizer of the present invention is in the range of 20 to 200 particles, but the coverage rate for maintaining this film thickness varies greatly depending on the particle size (particle size) and shape. The thickness of these films is 20g
In the range below 200, it is difficult to sufficiently suppress elution.
There are almost no cases where a film thickness exceeding that required is required, and the preferred range is usually 20 to 120 g for the known slow-release type, and 80 to 200 g for the time capsule type.

In addition, the influence of the properties of granular fertilizer on the setting of the elution period Δ
received greatly. Even if the same particle size and shape, the same coating composition, and the same film are used, the type of fertilizer (e.g. urea,
The duration of elution may vary by more than 10 times depending on the amount of sulfur, potassium, etc.).

When designing the coated granular fertilizer of the present invention, first the type, particle size and shape of the fertilizer, which is the core substance, are determined, and then the film thickness and coverage are determined. Under these specific conditions, the sustainability of elution is investigated for slow-release type, but this method is based on the four methods mentioned above: surfactant, filler, specified polymer material, specified Combinations of one or more of the waxes described above are possible, and there are many combinations with the same long-lasting composition.

For example, in order to create a coating that has the same elution-sustaining function as a coating made only of poly-3-hydroxypropionic acid-based materials, we first add substances that retard the elution, such as polymeric materials such as polyethylene or waxes such as hydrogenated oil. Poly 3-hydroxy-3-hydroxy-3-alkylpropionic acid-based materials can be mixed to create a composition with increased elution sustainability, and fillers and surfactants can be added to promote elution.
This means that a material having the same elution sustaining function as a 3-alkylpropionic acid-based material can be produced.

Although there are infinite combinations based solely on elution sustainability, there are restrictions from other properties.

The first constraint is the strength of the coating; if the filler exceeds 80% of the coating weight, the coating strength will weaken, and when handled as a general-purpose fertilizer, the coating may be damaged and the elution control function may be impaired. . Similarly, when waxes such as paraffin and hardened oil used as elution retarders exceed 50 TI'f amount relative to other polymeric materials, problems occur in film strength.

The second constraint is the microbial degradability of the coating, and if there are many macromolecules that are not degradable by microorganisms in the coating V, the decomposition of the coating will be inhibited. This will vary depending on the presence or absence of a microbially degradable filler and its amount, but if this is not available, the amount of microbially non-degradable resin should be kept to less than 40% (by weight) of the polymer material, and if a microbially degradable filler is used. In most cases, it should be at most 60%.

The coated granular fertilizer of the present invention is covered with a film degradable by microorganisms, and is eroded by soil microorganisms, so it tends to elute more quickly than in water, particularly in soils with strong microbial activity. These tendencies can be adjusted by ■ increasing the proportion of polymeric materials that are non-degradable by microorganisms, ■ using a disinfectant in combination, and covering the surface with an ultra-thin protective film. It is difficult to provide exactly the same functionality as the one covered by. However, the product of the present invention is useful for today's agriculture as an elution control fertilizer, and is extremely significant as the first elution control fertilizer in the northern world made of microbially degradable polymeric materials.

Furthermore, the present invention can also produce a time capsule type fertilizer in which the film thickness is increased compared to the slow-release type to suppress elution, and the entire amount is eluted in a short period of time (when the film is broken due to II biodegradation). Although these elution suppression periods can be controlled to a certain degree by suppressing the decomposition described in (1), (2), and (2), they are still incomplete. However, the present invention is also significant as it opens the way to a completely controlled time capsule type fertilizer.

The present invention is applicable to granules containing all fertilizer components. Namely ammonium sulfate, ammonium chloride, ammonium nitrate, urea, chloride, potassium sulfate,
It is particularly effective for fertilizers containing single components useful as water-soluble fertilizers such as potassium nitrate, sodium nitrate, ammonia phosphate, potassium phosphate, and lime phosphate, or two or more of these components. Also OMUP (crocilidene diurea), IBD
When applied to poorly soluble fertilizers such as U (imbutylidene diurea) and oxamide, the effective period of these fertilizers can be extended.

The coating material of the method of the present invention can be dissolved in an organic solvent or dissolved in 1"f!
It is used by Ishi. The solvent used at this time is one that dissolves polymeric materials and waxes, and is soluble when heated to the poly-3-hydroxy-3-alkylpropionic acid-based material essential to the present invention. This solvent was selected from a group of solvents that cause the polymer to precipitate fine crystals and become cloudy when it is cold, but it becomes jelly-like. The solution for these coatings or the solution in which a predetermined filler is dispersed is kept at a high temperature so that the polymer material in the solution does not precipitate or become jelly-like, and is sprayed and granulated with a high-speed hot air stream. It is essential that the fertilizer be sprayed and the solvent be dried instantly.

The selection of the solvent in the method of the present invention is a necessary condition to prevent the particles from forming blocks and becoming cake-like due to the adhesiveness of the polymeric material during coating, and instant drying by high-speed hot air flow is a necessary condition for preventing the solution from forming a cake. 5. The polymer may precipitate during the cooling or concentration process through evaporation, inhibiting the original film formation of the polymer.
This is a necessary condition for achieving this goal.

The product of the present invention can be obtained by selecting the solvent and maintaining the drying conditions as described above, but the speed of the hot air flow that is injected together with the coating liquid is 1.
The number of layers is required to be 0.0 cm/sec or more, preferably 15 layers/sec or more.

When using powder as a filler in the coating according to the present invention, it is necessary to forcibly stir the powder in a dissolution tank or the like so that the powder is uniformly mixed in the organic solvent solution without settling or floating. It is necessary to adjust the viscosity of the coating material so that the viscosity of these coating liquids becomes 50 cp or less at the temperature in which they are used. 50c
If the viscosity is higher than p, even if the solvent is selected as described above, some blocking cannot be avoided, so in this case it is necessary to further dilute the solvent before use.

A spray layer device is the most suitable and most recommended device for performing coating while maintaining these conditions of the method of the present invention. The general shape of a spouted bed device is an inverted conical lower part, the lowermost part of which has an air outlet. When particles are placed in this tank and hot air is ejected from the jet nozzle, the particles are ejected upward, then fall into the tank and circulate as if they are ejected again. The product of the present invention can be easily obtained by installing a coating liquid spray nozzle at this spout and spraying the sprayed particles. At this time, the temperature of the particles during coating is maintained at an upper limit at which the polymeric material does not fuse or the coating is damaged.

The present invention will be explained below with reference to Examples.

Example (1) Selection of solvent used in the method of the present invention Poly(3-/\hydroxy-3-methylpropionic acid) was placed in a large test tube.
0.3g (molecular weight 750,000) and test solvent 3
Place Otsl in an oil bath and gradually raise the temperature (°C/win is the guideline) while stirring to dissolve. At this time, if signs of dissolution are seen, the temperature increase rate is further slowed down to determine the melting temperature. Once completely dissolved, stop stirring, remove from the oil bath, and allow to cool slowly by natural cooling. During this slow cooling process, some products may become cloudy or jelly-like, and the temperature at this time is considered to be the gel of this solution. Solvents that can be used in the present invention have a gel point. Examples of searches for such solvents are shown in Table 1.

Table 1 (2) Effect of accelerating elution of filler 1) Figure 1 shows the jet coating apparatus used for manufacturing the prototype in this example. l is a jet tower with a tower diameter of 200 mm and a height of 1
500mm, air outlet diameter 45mm, cone angle 50°,
It has a fertilizer input port 2 and an exhaust gas discharge port 3. Jet air is sent from the blower 10 and reaches the jet tower via an orifice flow meter 9 and a heat exchanger 8, but the flow rate is controlled by the flow meter, the temperature is controlled by the heat exchanger, and the exhaust air is discharged from the exhaust port 3 to the outside of the tower. derived. The granular fertilizer used for coating is introduced from the fertilizer inlet 2 while passing a predetermined hot air to form a jet stream. The hot air temperature is detected by thermometers T+, the particle temperature in the coating is T2, and the exhaust temperature is T3. When T2 reaches a predetermined temperature, the coating liquid is sprayed in the form of a spray through the fluid nozzle 4 toward the jet stream. The coating liquid is stirred in the liquid tank 11, and if powder is used, it is stirred so that the powder is uniformly dispersed in the coating chamber.The coating liquid is sent from the pump 5 and reaches the nozzle. The fertilizer is heated with steam so that the temperature does not drop below ℃. When the predetermined coverage rate is reached, the blower is stopped and the covered fertilizer is discharged from the extraction lower.

Sample production in this example was carried out under the following conditions.

Solvent Nitrichloroethylene - Fluid nozzle
: Opening 0.8 intestinal layer full control type air volume
: 2.5m3/sin Fertilizer type: 5-8 +
Mech granular urea fertilizer input amount: 3 kg Coating liquid concentration: Solid content 2% (weight) Coating liquid supply amount: 0.2 kg/win Coating liquid supply time: 38 m1n Coverage rate: 5% (relative to fertilizer) 2) Elution The elution rate of the 7N+11 prototype sample was determined by the following method.

10g of sample was immersed in 200ml water and sealed for 2 hours.
Leave it at 5°C. After a predetermined period of time, the sample and water are separated and the urea eluted into the water is determined by quantitative analysis, and the percentage of total urea and eluted urea in the test sample is determined and used as the elution rate.

After measuring the dissolution rate, the sample (coated urea) was immersed in 200 μm of fresh water again, left to stand at 25°C, and the dissolution rate was determined again in the same manner. The number of days of standing on the horizontal axis and the cumulative dissolution rate on the vertical axis are drawn on a graph and connected with lines to form a dissolution rate curve.

3) The sample coating materials and coating conditions are shown in Table 2.

Table 2 Further, the results of elution rate measurement are shown in FIG.

(3) Example of combined use with waxes Sample preparation and measurement of elution rate were performed in the same manner as for front nail 2. The sample coating materials and coating conditions are shown in Table 3, and the results of elution rate measurement are shown in Figure 3.

Table 3 (4) Example of use in combination with polymeric materials Since a flammable solvent is used on the wood flow side, air-cooled and separated N2 gas is piped to the blower 10 in Figure 1, and N2 gas is used instead of air to blow the jet. coated. The conditions for sample production are as follows.

Solvent: Toluene Nozzle: Opening 0
．． 8■ Full control type (-fluid nozzle) N2 quantity
: 2.5 rn'/win Fertilizer type: 5~
8 Mesh granular urea fertilizer input M: 3 kg Coating liquid concentration: Solid content 2% (weight) Coating liquid supply, 5
1: Q, 15kg/win coating liquid supply time
: 5Qmin Coverage rate: 5% (relative to fertilizer) The elution rate measurement of the trial sample was carried out in the same manner as in the previous section 2.

The sample coating materials and coating conditions are shown in Table 4, and the results of elution rate measurement are shown in Figure 4.

Table 4 (5) Elution in soil and soil decomposition of film 1) Soil elution Paddy soil (Nagano Town, Minamata, sandy loam) was air-dried for 10 m.
The mixture was sieved using a sh sieve and the bottom of the sieve was used for testing. 250 g of soft soil is mixed with 2 g of the coated granular fertilizer sample of the present invention, placed in a 50 hu polyethylene bottle, and 150% of the maximum capacity water is added to form a paddy field and left at 25°C. After a predetermined period of time, the entire amount of soil containing the sample is transferred onto a 10 mesh sieve and sieved in water to separate the sample and soil.

Carefully pick up the sample remaining on the sieve one by one.
The entire amount is transferred to a mortar, ground and made up, and the urea in the solution that is filtered through dry filter paper is analyzed to determine the total amount of urea remaining in the coating. The elution rate in soil is calculated using the following formula.

The results of testing samples No. 13 to 16 are shown in the fifth
As shown in the figure.

2) Soil decomposition test for film: Each 5g sample of the present invention was made a pinhole using a sharp needle, and immersed in water at 30°C for 2 hours. ! Leave it to stand for a while to dissolve the urea inside and create an empty capsule. The empty capsules separated from the eluate were used in (1) for drying of the soil ±400g.
Mix with water, add water to reach 60% of the maximum water capacity, cover with polyvinylidene chloride film, and leave in a constant temperature bath at 30°C. The capsules are dug out every two months and the condition of the capsules is observed, and the evaporated moisture is corrected during this period. Table 5 shows these observation conditions.

Under the sample production conditions of Table 5 (6) Example 2-1), the coating solution supply time was extended by 78 minutes (double) to increase the coverage by 10%.
Samples were prepared using the raw materials shown in Table 6 (for fertilizer). The dissolution rate of this sample in water was determined by the method of Example 2-2), and the dissolution rate in soil was determined by the method of Example 5-1). Ta.

Table 6

[Brief explanation of drawings]

FIG. 1 is a flow sheet of the apparatus used in the method of the present invention, and FIGS. 2 to 6 are detailed explanatory diagrams of the present invention. Patent applicant for the above Patent attorney: Chisso Corporation Yatabe Sasai Katsuhiko Uenonaka 22
Chi k 2. Name of the invention Granular fertilizer coated with a degradable film and its manufacturing method 3. Relationship with the case of the person making the amendment Patent applicant representative Sadao Nogi 4, attorney 6. No number of inventions increased by amendment. 7. Each column of the claims and detailed description of the invention of the specification to be amended. 8. The detailed statement of amendments will be amended as follows. A. Correct the entire text of the claims as shown in the attached sheet. The detailed description of the B0 invention is amended as follows. (1) Correct "wa," in line 10 of page 6 to "ni,". (2) On the last line of page 7, after “shi, mata”, “fertilizing ingredients”
Insert. (3) Insert "fertilizing ingredient" after "in cell type" on page 8, line 4. (4) Insert "degradability" after "microorganisms" in the fifth line from the bottom of the same page. (5) "Water-soluble" on page 13, line 15 is corrected to "poorly water-soluble." (6) Insert "-3-alkyl" after "3-hydroxy" on page 21, line 3. (7) On page 24, line 8, "precipitate crystals" is corrected to "precipitate as crystals." (8) On page 25, line 13, insert ``obtainable coated granular fertilizer'' after ``even if''. (9) On the 144th line of the same page, insert ", coating liquid" after "in this case". (10) "Figure 3" on page 31, line 4 is corrected to "Figures 3-1 and 3-2." (11) After “sample” on page 34, line 8, “wo”
Insert. (12) On the same page, line 111, “grind and female up” is changed to “
Grind and dissolve the ground sample in a volumetric flask with water to fill to the mark. (13) From rNo. 13 to IS on the second line from the bottom of the same page.”
is corrected to ``from rNoll to 14''. (14) Page 37, line 1, “Example 2-1) J to r (
2)-1) Correct to J. (15) In the 4th line of the same page, "Example 2-2) J is replaced with "(2)-
2)”. (1st) Change “Example 5-1) J” to “(5)-” on the 5th line of the same page.
1)”. 9. Attached documents (Full text of claims) At least 1 Attachment (Full text of claims) (1) A degradable coating containing poly-3-hydroxy-3-alkylpropionic acid as an active ingredient. A coated granular fertilizer. (2) The granular fertilizer according to claim (1), wherein the alkyl group is a methyl group or an ethyl group. (3) In addition to poly-3-hydroxy-3-alkylpropionic acid, the degradable coating is made of polyvinylidene chloride, polyolefin, rubber, ethylene/vinyl acetate copolymer, polystyrene, polymethyl methacrylate, ethylene/carbon monoxide, etc. Polymers, resins such as ethylene/vinyl acetate/carbon monoxide copolymer, ethylene e ethyl acrylate copolymer, ethylene methacrylic acid copolymer, paraffin, hydrogenated oil, solid fatty acids and their metal salts, beeswax, The granular fertilizer according to claim 1, comprising one or more substances selected from low-molecular resin substances such as wood wax petroleum resins and rosin. (4) Claim No. 1 in which the degradable coating is inorganic or organic and contains poorly water-soluble or insoluble powder.
or the granular fertilizer described in paragraph (3). (5) According to claim (4), the Muichiga powder is talc, clay, silica, diatomaceous, metal oxide, or sulfur powder, and the organic powder is starch or crotylidene diurea powder. Fertilizers listed. (6) An organic solvent solution of poly-3-hydroxy-3-alkylpropionic acid is added to a fluidized granular fertilizer in a spray form, and at the time of addition, a high-speed hot air stream is blown onto the granular fertilizer to remove the added organic solvent. A method for producing a granular fertilizer coated with a degradable film, which is characterized by instantaneously removing and drying an organic solvent in a solvent solution. (7) In addition to poly-3-hydroxy-3-alkylpropionic acid in an organic solvent solution, polyvinylidene chloride, polyolefin, rubber, ethylene/vinyl acetate copolymer, polystyrene, polymethyl methacrylate, ethylene/
Carbon monoxide copolymer, ethylene-vinyl acetate carbon monoxide copolymer, ethylene-ethyl acrylate copolymer, ethylene methacrylic acid copolymer resins, paraffin, hydrogenated oil, solid fatty acids and their metal salts. ,
The manufacturing method according to claim (6), wherein one or more substances selected from low-molecular resin substances such as beeswax, wood wax, petroleum resin, and rosin are dissolved and used. (8) The manufacturing method according to claim (6) or (7), wherein an inorganic or organic water-saving soluble or insoluble powder is further mixed and dispersed in the organic solvent solution. (9) Claim 8, wherein the inorganic powder is talc, clay, silica, diatomaceous, metal oxide, or sulfur powder, and the organic powder is starch or crotylidene diurea powder. Production method. Procedural amendment 1, 4jG indication Patent Application No. 183.901 of 1986 2, Title of invention Granular fertilizer coated with a degradable film and its manufacturing method 3, Person making the amendment Relationship with the case Patent applicant 3-6-32 Nakanoshima, Kita-ku, Osaka-shi, Osaka (530)
4. Agent 8. The number of inventions will not increase due to the amendment. 7. Detailed description of the invention in the specification subject to amendment. 8. I amend the statement of contents of the amendment as follows. (1) On page 18, line 11, after “acid-based materials”, write “
Insert "degradable coating material that can be used in combination with the above". that's all

Claims (1)

[Scope of Claims] (1) A granular fertilizer coated with a degradable film containing poly-3-hydroxy-3-alkylpropionic acid as an active ingredient. (2) The granular fertilizer according to claim (1), wherein the alkyl group is a methyl group or an ethyl group. (3) In addition to poly-3-hydroxy-3-alkylpropionic acid, the degradable coating is made of polyvinylidene chloride, polyolefin, rubber, ethylene/vinyl acetate copolymer, polystyrene, polymethyl methacrylate, ethylene/carbon monoxide, etc. Polymers, resins such as ethylene/vinyl acetate/carbon monoxide copolymers, ethylene/ethyl acrylate copolymers, ethylene methacrylic acid copolymers, paraffins, hydrogenated oils, solid fatty acids and their metal salts, beeswax, The granular fertilizer according to claim 1, comprising one or more substances selected from low-molecular resin substances such as wood wax petroleum resins and rosin. (4) Claim No. 1 in which the degradable coating is inorganic or organic and contains poorly water-soluble or insoluble powder.
or the granular fertilizer described in paragraph (3). (5) Claim 4, wherein the inorganic powder is talc, clay, silica, diatomaceous earth, metal oxide, or sulfur powder, and the organic powder is starch or crotylidene diurea powder. fertilizer. (6) An organic solvent solution of poly-3-hydroxy-3-alkylpropionic acid is added to a fluidized granular fertilizer in a spray form, and at the time of addition, a high-speed hot air stream is blown onto the granular fertilizer to remove the added organic solvent. A method for producing a granular fertilizer coated with a degradable film, which is characterized by instantaneously removing and drying an organic solvent in a solvent solution. (7) In addition to poly-3-hydroxy-3-alkylpropionic acid in an organic solvent solution, polyvinylidene chloride, polyolefin, rubber, ethylene/vinyl acetate copolymer, polystyrene, polymethyl methacrylate, ethylene/
Carbon monoxide copolymer, ethylene/vinyl acetate/carbon monoxide copolymer, ethylene/ethyl acrylate copolymer, ethylene methacrylate copolymer resins, paraffin, hydrogenated oil, solid fatty acids, and their metal salts. ,
The manufacturing method according to claim (6), wherein one or more substances selected from low-molecular resin substances such as beeswax, wood wax, petroleum resin, and rosin are dissolved and used. (8) Claims (6) or (7) further include mixing and dispersing an inorganic or organic water-soluble or insoluble powder in an organic solvent solution.
) The manufacturing method described in section 2. (9) Claim 8, wherein the inorganic powder is talc, clay, silica, diatomaceous earth, metal oxide, or sulfur powder, and the organic powder is starch or crotylidene diurea powder. Production method.