JPH07215804A - Controlling material for release of agrochemical or the like - Google Patents

Abstract

PURPOSE:To obtain a controlling material for release of an agrochemical having not only function of controlling release of an agrochemical, etc., but also func tion of improving soil by extremely simple and inexpensive production facilities by utilizing a natural material not causing fear of secondary environmental disruption. CONSTITUTION:An agrochemical, etc., are impregnated to stuck to a great number of pores of particles composed of coral fossil as a material. On the other hand, the diameters (d) of the particles are uniformed by taking advantage of the characteristic of water solubility of calcium carbonate as a main component of the coral fossil and duration time of release of the agrochemical, etc., impregnated and stuck to the pores, to soil is estimated and controlled from a dissolution and extinction time (t) of the particles.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is applicable to pesticides such as insecticides, pest control agents, fungicides, plant growth regulators and herbicides when they are sprayed or embedded in soil. TECHNICAL FIELD The present invention relates to a pesticide release control material capable of predictively controlling the release of pesticides so as to reach a certain amount at a particular time.

[0002]

2. Description of the Related Art In recent years, pesticides have become undecided in the fields of agriculture and horticulture, while the toxicity to humans and livestock and damage to the environment have increased, and existing drugs have been reviewed. Therefore, improvement of physical properties, formulation method, application method, etc. is required. Above all, attention has recently been paid to pesticide release control technology for improving application methods.

[0003] Many pesticide release control techniques mainly utilize the interaction between pesticides and polymer compounds. The technique is one for diffusing a drug in a polymer medium, for example, the highly toxic pesticide methylparathion. It is known that the above is encapsulated with a crosslinked polyamide-polyurea film to reduce toxicity and increase residual efficacy.

On the other hand, for example, a release control material prepared by adsorbing a pesticide on an adsorbent material such as white carbon, natural clay, talc, diatomaceous earth, calcium carbonate, bentonite, or attapulgite is sprayed on the soil. Techniques for increasing the residual effect are known.

Further, for example, a controlled release technique for holding a pesticide in a material having a capillary tube such as a hollow fiber, a porous plastic or a foam is well known.

[0006]

However, such conventional pesticide release control materials are used in order to emphasize the hardness and adsorption capacity of the material or the stability of the pesticide, or to add or release a function such as soil improvement. In order to control the time, a polymer agent, a binder and other chemicals are often added, which is not enough for environmental preservation of the soil after application, and there is a concern that the production cost will be high.

The object of the present invention is not only to provide a release control function for pesticides and the like but also to improve soil by using a natural material that does not cause a secondary environmental damage and using a very simple and inexpensive production facility. It is an object of the present invention to provide an excellent release control material for agricultural chemicals, which also has

[0008]

In order to achieve the above object, the present invention uses coral fossils from natural materials,
Since the coral fossil particles have a large number of pores,
Agrochemicals and the like are impregnated or attached into the pores, while the calcium carbonate, which is the main component of the coral fossil, is water-soluble, and the diameters of the particles are adjusted to specific values.
Then, as the particles elute from the surface layer, the agricultural chemicals in the pores are released into the soil, and the release continues until the dissolution of the particles is completed. The duration of release of pesticides impregnated or impregnated into the pores into the soil is predicted and controlled.

The coral fossil particles have a particle size of 0.8 mm for 1 hour, 1.0 mm for 5 hours, 1.2 mm for 1 day, 1.7 mm for 1 week, and 2. 2m
m for 1 month, 3.0 mm for 7 months, 3.3 mm for 1
It melts and disappears in 10 years at 4.8 mm per year.

Since many of the pores of the coral fossil particles are made of a natural material, most of them are clogged with impurities such as a diaphragm, carcasses of symbiotic algae, and foraminiferal shells. Therefore, the impregnation efficiency of agricultural chemicals is low in such a natural state. Therefore, the state in which the characteristic that calcium carbonate, which is the main component of coral fossils, is water-soluble is maintained, that is, the coral fossils are not in the crystalline form of calcite, but in the crystalline form of argonite, to remove the impurities in the pores. Is desired.

To meet the above requirements, coral fossil particles are fired in a temperature range of 200 to 250 ° C. in an air-shielded atmosphere. That is, for example, in concrete terms, coral fossil particles are put in a rotary firing furnace,
1 to 100 liters of nitrogen gas per second, or 1 to 2 per second
Firing is performed while supplying 50 liters of carbon dioxide gas.

Impregnation of pesticides into the pores of coral fossil particles is carried out when the pesticide is an emulsion or a liquid agent, and the ratio of the particles is 1.0 to the emulsion or liquid agent of 5.0 or less by weight ratio. It is achieved by immersing, taking out, and drying.

When the pesticide is a wettable powder or powder, by mixing the wettable powder or powder at a weight ratio of 0.1 to 1.0, the pores of the coral fossil particles are mixed. Impregnation or attachment of pesticides can be achieved.

[0014]

The coral fossil particles used in the present invention are weathered coral fossil reefs, and their composition is about 92% calcium carbonate. When the particles are sprayed in the soil or on the ground surface, 92% of the calcium carbonate component is water-soluble because it maintains the crystalline form of aragonite, and the water in the soil causes dissolution of each particle from the surface layer.

The relationship between the particle size of coral fossils and the dissolution disappearance time is as follows. First, the particles have a uniform spherical shape, and their apparent density ρ = 2.5 g / cm.
³ and then, assuming a solubility in water of the main component CaCO ₃ and 0.0015g / 100gH ₂ O, the diameter of the particles d, dissolution annihilation time t, the pH changes as a parameter, when log-log plot, FIG. 1 As shown in, all pH changes are shown in a relationship of equilibrium movement. When the equation of each straight line is obtained, it becomes 0.16 to time t, and p
The change in H is 0.077. Therefore, if this is calculated as a straight line equation, the particle diameter d is d (cm) = 0.077 × t ^0.16 (1) From the equation (1), the time t is t (hr) = (d / 0.007) ^{1 / 0.16} ... (2).

For example, when the particle diameter d = 0.1 cm,
Substituting that value into equation (2), t = (0.1 / 0.077) ^{1 / 0.16} = _0.16 √ (0.1 /
0.077) = 5.12 (hr), and when the particle diameter d = 0.3 cm, t = 4914 (hr) ≈205 days≈7 months.

Thus, the relationship between the particle diameter d and the dissolution disappearance time t is as shown in FIG. 1 and Table 1 from the above equations (1) and (2).

[0018]

[Table 1]

As described above, coral fossil particles have different times t in which they dissolve and disappear in soil depending on the size of the diameter d. Therefore, the particles are sieved and classified according to the size of the diameter, Selective use of particles of the desired size provides predictive control of pesticide release duration in soil.

When calcium carbonate, which is the main component of coral fossils, dissolves in the water in the soil, carbon dioxide is released by combining with the hydroxyl groups. Therefore, the amount of water in the soil increases and the diffusion of essential substances in the soil becomes easier, while the generated carbon dioxide gas improves the aeration in the soil to help the activity of aerobic microorganisms, and further becomes calcium hydroxide. By
It also has a soil improvement function such as keeping the soil that easily shifts to the acidic side to be weakly alkaline.

[0021]

EXAMPLE First, the composition of the coral fossil raw material used in this example will be shown in the order of wt% as follows. CaCo ₃ 91.67 CaO 51.36 Ca 36.71 MgO 2.20 Na 0.50 Sr 0.11 Si 0.04 P 0.028 Al 0.0055 B 0.0031 In the present invention, for example, such a composition is used. From the coral fossil raw material having the above, the release control material for agricultural chemicals is produced through a firing step and an impregnation or attachment step exemplified below.

First, the firing process of coral fossil particles will be described below. Particles of coral fossil having the above composition are stored in the hopper 2 via the screen 1 in FIG. 2, and the stored particles are sequentially supplied from the hopper 2 to the trans mill 3 in an appropriate amount. It In the trans mill 3, the coral fossil particles are crushed from large particles to small particles by a frictional action, and at the same time, sharp-angled projections of the particles are scraped off by a wear action and processed into a rounded non-projection shape.

Next, each particle processed by the trans mill 3 falls on the belt conveyor 4 from the lower discharge hole and is conveyed toward the screw conveyor 5. The screw conveyor 5 is provided at the entrance of the firing furnace 6, and each particle is pressure-fed into the firing furnace 6 by the rotation of the screw.

As shown in the figure, the firing furnace 6 has a cylindrical body 7 installed in a posture having a gentle gradient from the inlet to the outlet.
And a mechanism for imparting rotation to the cylindrical body, an atmosphere forming unit that shuts off air, and a hot air supplying unit.

The rotating mechanism of the cylindrical body 7 is composed of a driven gear 8 provided along the circumferential direction of the outer peripheral surface of the cylindrical body 7 and a drive gear 10 mounted on the output shaft of the electric motor 9, whereby the driven gear 8 is engaged. The cylindrical body 7 is rotated four times per second, for example. The particles of the cylindrical body 7 are processed into a non-projection shape by further scraping the projections of the particles due to the rolling caused by the rotation, and the gas is sufficiently and evenly supplied between the particles by the rolling. A favorable atmosphere is created for the formation of pores, and the rolling is prevented from partially forming an atmosphere having a temperature higher than the set temperature in the particle group in the furnace. Stable work within the range is guaranteed.

An example of means for forming an air blocking atmosphere in the cylindrical body 7 is as follows. For example, nitrogen gas cylinder 1
1 is provided, and from there, 1 liter to 100 liters of nitrogen gas is supplied into the cylindrical body 7 through the gas reservoir 12 per second. Alternatively, instead of the nitrogen gas cylinder 11, a carbon dioxide gas cylinder 13 is provided, and 1 liter to 50 liters of carbon dioxide gas is supplied into the cylindrical body 7 from there through the gas reservoir 12 per second. By supplying the nitrogen gas or carbon dioxide gas, the oxygen-containing air in the cylindrical body 7 is removed. Therefore, the particles in the furnace are fired without the supply of oxygen. As described above, the firing proceeds in an atmosphere in which the supply of air, especially oxygen is blocked, so that the state of calcium carbonate CaCo ₃ which is the main component of the particles is maintained and the change to calcium oxide CaO is prevented. As a result, since the weak alkalinity of the particles is maintained, the particles are dissolved in the soil and the acidification of the soil is hindered to maintain a good soil condition.

The means for supplying hot air into the cylindrical body 7 is the combustion chamber 1
4 is provided, and hot air whose temperature is adjusted to 200 to 250 ° C. in the combustion chamber is supplied toward the cylindrical body 7 by the blower 15 and the contact time with the particles is 10 to 30 minutes. . The temperature of the hot air supplied is 200-25 °
Since it is in the range of C, in this temperature range, the crystal form of calcium carbonate, which is the main component of the coral fossil particles, does not change to the calcite crystal form, and the crystal form of the algonite is maintained even after firing. The degree is maintained, and the carcasses of the symbiotic algae remaining in the pores of the particles, the shells and partition walls of the foraminifera are melted or burned down to form a gap.

The particles that have been baked are stored in the second hopper 16
It is carried out into the crusher 17 via. Since the crusher 17 is constantly supplied with air at room temperature from the second blower 18, each particle in the machine is cooled rapidly and reaches room temperature,
It is crushed to a diameter within 5.0 mm.

The crushed particles are sent to the sorting machine 20 via the second belt conveyor 19, where they are classified according to the size of the particles.

Next, as shown in FIG. 3, the coral fossil particles, which have been calcined and the size of which has been determined, are sent to the step of impregnating or impregnating the agricultural chemicals. In this step, first, the particles are carried into the solid-liquid reaction device 23 from the hopper 21. The solid / liquid reaction device 23 is supplied with a liquid pesticide in an amount of 5 times the weight of the particles after firing from the chemical liquid tank 25. Therefore, the coral fossil particles and the liquid pesticide are reacted for 3 hours by the batch operation of the solid / liquid reaction device 23, and then the mixture thereof is carried out to the single-stage extrusion separator 24.

In the separator 24, the pesticide-impregnated particles and the liquid pesticide not impregnated into the particles are separated, and the separated liquid pesticide is returned to the chemical liquid tank 22, while the pesticide-impregnated particles are rotated. It is carried into the dryer 26.

The rotary dryer 26 includes a hot air fan 2
Since, for example, dry air of 80 ° C. is supplied from 5,
The particles in the machine are dried rapidly, and the dried particles are sent to a sorting machine 27, where they are sorted according to the size of the particles.

Thus, the coral fossil particles can be obtained by the burning means and the pesticide impregnation or impregnation means shown in the above embodiment.
An average of about 10 mg of pesticide can be impregnated or attached per 1 g of particles. For example, the herbicide simazine, paraquat, diphenamide, alachlor, per 1 g of particles,
It is possible to impregnate or impregnate 5 to 10 mg of methyl dymuron, tervanine, etc., 15 mg of pesticide parathion, and about 20 mg of bactericide iprodione.

[0034]

As described in detail above, the present invention utilizes coral fossil particles, which are natural materials without the risk of secondary environmental damage, and further, the particles have a large number of pores. And that the calcium carbonate as the main component of the particles is water-soluble, while impregnating or adhering the pesticide or the like into the pores, while adjusting the particle size to a desired value, The duration of release of pesticides impregnated or attached to the pores of the particles into the soil can be predicted and controlled from the dissolution disappearance time of the particles.

Furthermore, the present invention also has a soil improving function such that the dissolution of calcium carbonate, which is the main component of coral fossil particles, in the soil prevents the acidity of the soil to make it weakly alkaline.

Further, the present invention has a great effect on the art since the release control material for agricultural chemicals having the soil improving function can be produced by a relatively simple and inexpensive process.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a relationship between a particle diameter d of a pesticide release controlling material according to the present invention and a dissolution disappearance time t thereof,

FIG. 2 is a schematic explanatory view mainly illustrating a firing step in a production process of a release control material for agricultural chemicals according to the present invention,

FIG. 3 is a schematic explanatory view illustrating the pesticide impregnation or attachment process in the production process of the pesticide release control material according to the present invention,

[Explanation of symbols]

 1 Screen 2 Hopper 3 Transmill 4 Belt Conveyor 5 Screw Conveyor 6 Firing Furnace 7 Cylindrical Body 8 Driven Gear 9 Electric Motor 10 Drive Gear 11 Nitrogen Gas Cylinder 12 Gas Reservoir 13 Carbon Dioxide Cylinder 14 Combustion Chamber 15 Blower 16 Second Hopper 17 Crusher 18 18th 2 Blower 10 Second belt conveyor 20 Sorting machine 21 Hopper 22 Chemical liquid tank 23 Solid / liquid reaction device 24 Single-stage extrusion type centrifugal separator 25 Hot air fan 26 Rotary dryer 27 Sorting machine

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[Procedure amendment]

[Submission date] March 15, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 5

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 6

[Correction method] Change

[Correction content]

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

Since many of the pores of the coral fossil particles are made of a natural material, most of them are clogged with impurities such as a diaphragm, carcasses of symbiotic algae, and foraminiferal shells. Therefore, the impregnation efficiency of agricultural chemicals is low in such a natural state. Therefore, the state in which calcium carbonate, which is the main component of coral fossils, maintains the property of being water-soluble, that is, the coral fossils are not in the crystalline form of calcite, but in the crystalline form of aragonite, the impurities in the pores can be removed. desired.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction content]

To meet the above requirements, coral fossil particles are fired in a temperature range of 200 to 250 ° C. in an air-shielded atmosphere. That is, for example, in concrete terms, coral fossil particles are put in a rotary firing furnace,
1 to 100 liters of nitrogen gas per minute, or 1 to 1 minute per minute
Firing is performed while supplying 50 liters of carbon dioxide gas.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction content]

[0021]

EXAMPLE First, the composition of the coral fossil raw material used in this example will be shown in the order of wt% as follows. CaCO ₃ 91.67 CaO 51.36 Ca 36.71 MgO 2.20 Na 0.50 Sr 0.11 Si 0.04 P 0.028 Al 0.0055 B 0.0031 In the present invention, for example, such a composition is used. From the coral fossil raw material having the above, the release control material for agricultural chemicals is produced through a firing step and an impregnation or attachment step exemplified below.

[Procedure correction 6]

[Document name to be amended] Statement

[Name of item to be corrected] 0025

[Correction method] Change

[Correction content]

The rotating mechanism of the cylindrical body 7 is composed of a driven gear 8 provided along the circumferential direction of the outer peripheral surface of the cylindrical body 7 and a drive gear 10 mounted on the output shaft of the electric motor 9, whereby the driven gear 8 is engaged. The cylindrical body 7 is rotated four times per minute, for example. The particles of the cylindrical body 7 are processed into a non-projection shape by further scraping the projections of the particles due to the rolling caused by the rotation, and the gas is sufficiently and evenly supplied between the particles by the rolling. A favorable atmosphere is created for the formation of pores, and the rolling is prevented from partially forming an atmosphere having a temperature higher than the set temperature in the particle group in the furnace. Stable work within the range is guaranteed.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0026

[Correction method] Change

[Correction content]

An example of means for forming an air blocking atmosphere in the cylindrical body 7 is as follows. For example, nitrogen gas cylinder 1
1 is provided and nitrogen gas of 1 liter to 100 liters per minute is supplied into the cylindrical body 7 via the gas reservoir 12. Alternatively, instead of the nitrogen gas cylinder 11, a carbon dioxide gas cylinder 13 is provided, and 1 liter to 50 liters of carbon dioxide gas per minute is supplied into the cylindrical body 7 via the gas reservoir 12 from there. By supplying the nitrogen gas or carbon dioxide gas, the oxygen-containing air in the cylindrical body 7 is removed. Therefore, the particles in the furnace are fired without the supply of oxygen. As described above, the firing proceeds in an atmosphere in which the supply of air, especially oxygen is blocked, so that the state of calcium carbonate CaCO ₃ , which is the main component of the particles, is maintained and the change to calcium oxide CaO is prevented. As a result, since the weak alkalinity of the particles is maintained, the particles are dissolved in the soil and the acidification of the soil is hindered to maintain a good soil condition.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Name of item to be corrected] 0027

[Correction method] Change

[Correction content]

The means for supplying hot air into the cylindrical body 7 is the combustion chamber 1
4 is provided, and hot air whose temperature is adjusted to 200 to 250 ° C. in the combustion chamber is supplied toward the cylindrical body 7 by the blower 15 and the contact time with the particles is 10 to 30 minutes. . The temperature of the hot air supplied is 200-250
Since the temperature is in the range of ° C, the crystal form of calcium carbonate, which is the main component of the coral fossil particles, does not change to the calcite crystal form in this temperature range, and the crystal form of aragonite is maintained even after firing. The degree is maintained, and the carcasses of symbiotic algae, the shells of foraminifera, the diaphragm, etc. remaining in the pores of the particles are melted or burned to form gaps.

[Procedure Amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0035

[Correction method] Change

[Correction content]

Furthermore, the present invention also has a soil improving function such that the dissolution of calcium carbonate, which is the main component of coral fossil particles, in soil prevents acidification of the soil and makes it weakly alkaline.

Claims (8)

[Claims] 1. A pesticide or the like is impregnated or attached into a large number of pores of particles made of coral fossils, while utilizing the characteristic that calcium carbonate, which is the main component of the coral fossils, is water-soluble. By aligning the diameter of the particles to a specific value, the pesticide characterized by predicting the duration of release of the pesticides impregnated or impregnated in the pores into the soil from the dissolution disappearance time of the particles Equal emission control material. 2. As a measure of the dissolution and disappearance time of the particles,
Particle size 0.8 mm for 1 hour, 1.0 mm for 5 hours, 1.2
3. mm for 1 day, 1.7 mm for 1 week, 2.2 mm for 1 month, 3.0 mm for 7 months, 3.3 mm for 1 year, 4.
The pesticide release control material according to claim 1, wherein the material is 8 mm for 10 years. 3. The pesticide release control material according to claim 1, wherein the particles are fired within a temperature range in which the crystal form of aragonite is maintained, as means for expanding and maintaining a large number of pores included in the particles. 4. The pesticide release control material according to claim 3, wherein, as the firing means, the particles are fired in a temperature range of 200 to 250 ° C. in an atmosphere in which air is shut off. 5. As a means for forming a firing atmosphere in which air is shut off, 1 to 100 per second is placed in a rotary firing furnace containing the particles.
The pesticide release control material according to claim 4, wherein liter of nitrogen gas is supplied. 6. The pesticide release control material according to claim 5, wherein carbon dioxide gas of 1 to 50 liters per second is supplied instead of nitrogen gas. 7. As a means for impregnating or adhering a pesticide or the like into the pores of the particles, when the pesticide or the like is an emulsion or a liquid agent, the particles 1 to the emulsion or the liquid agent 5.0 or less by weight ratio are used. The pesticide release-controlling material according to claim 1, which is soaked in a ratio of 0.0, taken out, and then dried. 8. As a means for impregnating or adhering a pesticide or the like into the pores of the particles, when the pesticide or the like is a wettable powder or a powder, the weight ratio to the wettable powder or the powder is 0.1. The pesticide release control material according to claim 1, wherein the particles are mixed at a ratio of 1.0.