JP2012213383A - Iron powder for coating seed, and seed - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide iron powder for coating seeds which scarcely falls off not only during sowing but also during transportation and enables coating with less variation in seeds, and iron powder-coated seeds that are coated with the iron powder for coating seeds.SOLUTION: In the iron powder for coating seeds, that is iron powder used for coating seeds, the ratio by mass of iron particles having a particle size of 63 μm or smaller is controlled to 0-75%, the ratio by mass of iron particles having a particle size larger than 63 μm but not larger than 150 μm is controlled to 25-100%, the ratio by mass of iron particles having a particle size larger than 150 μm is controlled to 0-50%, and the content ratio of metal iron is 30.0-99.0 mass%.

Description

  The present invention relates to an iron powder suitable for rice seed coating and a seed coated with iron powder.

  Along with the aging of farmers and the globalization of agricultural product distribution, labor saving in agricultural work and reduction in agricultural production costs are issues to be solved. In order to solve these problems, for example, in paddy rice cultivation, a direct sowing method in which seeds are directly sown in a field is becoming widespread for the purpose of eliminating the trouble of raising seedlings and transplanting. Among them, in order to increase the specific gravity of seeds, a technique using seeds coated with iron powder has been attracting attention because of its merit of preventing floating and outflow of seeds in paddy fields and preventing bird damage.

  Thus, in order to utilize the direct sowing cultivation method using the seed coated with iron powder, it is required that the coated iron powder film is difficult to peel off in the transportation and sowing process. When the iron powder coating peels, the specific gravity of the seeds decreases and the above-mentioned merits are not obtained. This is because the peeled fine iron powder can cause dust. For this reason, peeling of the iron powder coating must be suppressed as much as possible.

As a technique for attaching and solidifying iron powder on the surface of rice seeds, Patent Document 1 proposes the following technique as a method for producing iron powder-coated rice seeds.
“To the rice seeds, iron powder, and 0.5-2% by weight of sulfate (excluding calcium sulfate) and / or chloride in a mass ratio to the iron powder, and further granulated by adding water, An iron powder-coated rice seed production method characterized in that iron powder is attached to solidified rice seeds by rust generated by the oxidation reaction of metallic iron powder by supplying water and oxygen, and then dried. (See claim 1 of Patent Document 1)

  In the invention described in Patent Document 1, since the rice seeds are sown using a power spreader or a seeder, strength characteristics that do not collapse due to mechanical impact are necessary. The coating disintegration degree is measured by a method of measuring the degree of coating disintegration (hereinafter referred to as coating disintegration test), that is, a method of dropping a steel sheet having a thickness of 1.3 m to a steel plate with a thickness of 3 mm and giving a mechanical impact. It has been confirmed that practical strength is obtained.

  In Patent Document 1, no particular attention is paid to the iron powder particle size distribution, but when iron powder having the particle size distribution shown in Table 1 below is used for coating, In the disintegration test, it is said that practical impact strength can be maintained.

Japanese Patent No. 44441645

Regarding the adhesion strength of the iron powder coating, Patent Document 1 discusses the collapse of the iron powder coating due to the impact caused by the drop in the seeding process. Therefore, as a strength test, a disintegration test is performed in which a mechanical impact is applied by dropping the steel sheet 5 times from a height of 1.3 m to a steel plate having a thickness of 3 mm.
However, rice seeds are subjected to mechanical external force not only in the sowing process but also in the transport process, as described above. And the mechanical external force which a rice seed receives in a transportation process is the frictional force of the sliding and rolling which arise between seeds or between a seed and a container other than the impact by fall.

When receiving an impact due to dropping, the iron powder coating is peeled off by cracking, but when receiving a frictional force, it is gradually peeled off by abrasion.
Therefore, in order to prevent the iron powder coating from peeling off not only in the seeding process but also in the transportation process, a coating having strength against frictional force is required.
However, there has been no technology for realizing iron powder that can cover rice seeds with sufficient strength against sliding and rolling frictional stress of seeds or seeds coated with iron powder.

Moreover, as shown in Table 1, the particle size distribution of the iron powder described in Patent Document 1 has a large proportion of particle sizes of 63 μm or less.
However, when fine iron powder is used, the iron powder reacts rapidly with oxygen in the air, and the seed coated with the iron powder may be damaged by heat generation, or cause a fire when handling a large amount of iron powder. There are also concerns. In addition, since fine iron powder tends to generate dust, there is a problem that it is difficult to maintain a clean working environment.

Moreover, in patent document 1, as a method of coat | covering a rice seed with iron powder, it is "Sulfate (except calcium sulfate except 0.5-2% by mass ratio with respect to a rice seed, iron powder, and iron powder). ) And / or chloride, and then add water and granulate.
An important factor in coating the surface of rice seeds with iron powder is to eliminate variation between rice seeds, but Patent Document 1 does not disclose anything about this.

The present invention has been made to solve such a problem, and coated with the seed coating iron powder and the seed coating iron powder capable of realizing a coating with less dropping of the iron powder not only in the sowing process but also in the transport process. The purpose is to obtain iron powder coated seeds.
Another object of the present invention is to obtain a rice seed coating iron powder that is less likely to damage rice seeds and is easy to handle and an iron powder coated rice seed coated with the rice seed coating iron powder. .

The inventor observed the surface of the rice seed and examined what kind of iron powder was effective in preventing peeling.
The inventor has focused on the condition of the surface of rice seeds. As shown in FIG. 1, hair 5 grows on the surface of rice husk 3 which is the outermost shell of rice seed pod 1, and when the seed pod 1 is coated with iron powder, the elastic action of the hair 5 causes It is presumed that the adhesion force is increased by holding the iron powder arranged between the bristles 5 to the bristles 5.
As shown on page 21 of “Seeing the Microscopic Structure of Rice (by Takamasa Mezaki)”, the way the hairs 5 grow is also dense. In particular, it is considered that the adhesion force is increased by the iron powder being held by the hairs 5 at the site where the hairs 5 are dense, and the interval between the hairs 5 at this site is 50 to 150 μm.
From this, the inventor considers that there is an appropriate range for the particle diameter of the iron powder that can be firmly attached to the rice seeds by the holding action by the hair 5, and the iron powder particle diameter for effectively exhibiting this holding action. As a result, it was found that a particle diameter of more than 63 μm and 150 μm or less is preferable.
From this, the knowledge that the particle diameter exceeds 63 μm and includes 150 μm or less to some extent can be expected to be retained by the hair 5, and the amount of peeling of the coating film caused by seed rolling or slipping can be reduced. It was.

The inventor also examined the particle size of the iron powder that passes through the hair 5 and adheres directly to the surface of the rice seed, in addition to the adhesion due to the holding power of the hair 5 of the rice seed.
In general, the smaller the particle size of the powder, the higher the adhesion to the adherend. Therefore, the particle size of the iron powder is preferably small in the sense that it is directly attached to the surface of the rice seed.
As a result of examining the iron powder particle size that can be expected to pass directly between the rice seed hairs 5 and directly adhere to the surface of the rice seed, it was found that a predetermined amount of iron powder of 45 μm or less is preferable.
And by containing the iron powder of the said fine particle size in addition to the iron powder hold | maintained by the hair 5, the iron powder of a fine particle size adheres to the surface of a rice seed, and iron above the hair 5 by iron 5 The powder was retained, and the iron powder was double-coated, and the knowledge that the amount of peeling of the coating film caused by the rolling and slipping of seeds can be reduced was obtained.
However, if the iron powder having a small particle size is contained in a large amount, the above-described problems occur, so that it is necessary to be a predetermined amount or less.

  Further, if the particle size of the iron powder is too large, not only does it not easily enter the gap between the hairs 5, but also the gravity acting on the iron powder particles is large and the hairs 5 cannot hold the iron powder particles, so the adhesion effect is reduced. Presumed. Accordingly, it was also found that the ratio of the iron powder having a particle size of 150 μm or more is preferably set to a predetermined amount or less.

  Furthermore, when the rice seeds were coated with iron powder, the means for ensuring the progress of rusting of the iron powder and realizing stable coating were also examined. As a result, it has been found that by defining the content ratio of metallic iron in the iron powder, rust is surely generated and stable coating becomes possible.

  In addition, when the rice seeds were coated with iron powder, we examined the requirements for coating with less variation between the seeds, and found that the fluidity of iron powder and the angle of repose of iron powder were important factors. Got.

The present invention has been made on the basis of the above findings, and specifically comprises the following constitution.
(1) The iron powder for seed coating according to the present invention is an iron powder used for coating seeds,
The mass ratio of iron powder having a particle diameter of 63 μm or less is 0% or more and 75% or less, the mass ratio of iron powder having a particle diameter of more than 63 μm and 150 μm or less is 25% or more and 100% or less, and the particle diameter exceeds 150 μm. The mass ratio of the iron powder is 0% or more and 50% or less, and the content ratio of metallic iron is 30.0 mass% or more and 99.0 mass% or less.

(2) Also, iron powder used to coat the seeds,
The mass ratio of iron powder having a particle diameter of 63 μm or less is 0% or more and 75% or less, the mass ratio of iron powder having a particle diameter of more than 63 μm and 150 μm or less is 25% or more and 100% or less, and the particle diameter exceeds 150 μm. The mass ratio of the iron powder is 0% or more and 50% or less, and the fluidity is 40 (sec / 50 g) or less.

(3) It is also an iron powder used to coat seeds,
The mass ratio of iron powder having a particle diameter of 63 μm or less is 0% or more and 75% or less, the mass ratio of iron powder having a particle diameter of more than 63 μm and 150 μm or less is 25% or more and 100% or less, and the particle diameter exceeds 150 μm. The mass ratio of the iron powder is 0% or more and 50% or less, and the angle of repose is 45 degrees or less.

(4) Moreover, in the thing in any one of said (1) thru | or (3), the mass ratio of the iron powder whose particle diameter is 45 micrometers or less is 0% or more and 30% or less, It is characterized by the above-mentioned. is there.

(5) Further, in any of the above (1) to (4), the mass ratio of the iron powder having a particle diameter of more than 63 μm and 150 μm or less is 50% or more. .

(6) Moreover, in the thing in any one of said (1) thru | or (5), iron powder is manufactured by the reduction method or the atomizing method.

(7) Moreover, the seed which concerns on this invention coat | covers the iron powder for seed coating | coated in any one of said (1) thru | or (6), It is characterized by the above-mentioned.

(8) In the above (7), the seed is a rice seed.

In the iron powder for seed coating according to the present invention, the mass ratio of the iron powder having a particle diameter of 63 μm or less is 0% or more and 75% or less, and the mass ratio of the iron powder having a particle diameter of more than 63 μm and 150 μm or less is 25% or more. 100% or less and the mass ratio of the iron powder having a particle diameter exceeding 150 μm is 0% or more and 50% or less, and the content ratio of metallic iron is 31.3% or more and 98.9% or less by mass. For example, seeds such as rice seeds with hair on the surface can be expected to be retained by hair, and a coating with less iron powder falling off can be realized not only in the sowing process but also in the transport process, and the formation of rust is ensured. A stable coating can be realized.
This makes it possible to save farm work and reduce production costs.

It is explanatory drawing explaining the state of the surface of a rice seed.

[Embodiment 1]
The iron powder for seed coating according to an embodiment of the present invention has a mass ratio of iron powder having a particle size of 63 μm or less and 0% or more and 75% or less, and a mass of iron powder having a particle size of more than 63 μm and 150 μm or less. The mass ratio of the iron powder having a ratio of 25% to 100% and a particle diameter exceeding 150 μm is 0% to 50%, and the content ratio of metallic iron is 30.0 mass% to 99.0 mass%. It is characterized by being.
Hereinafter, the reason why the particle size distribution and the content ratio of metallic iron are defined as described above will be described.

<Particle size distribution>
The reason why the iron powder having a particle diameter of more than 63 μm and not more than 150 μm is 25% or more is that the iron powder having a particle diameter of more than 63 μm and not more than 150 μm has a high probability of being held by the hair on the seed surface. By containing 25% or more of particles having a particle size, retention by hair can be expected, and a coating with less dropping of iron powder can be realized not only in the sowing process but also in the transport process. The mass ratio of the iron powder having a particle diameter of more than 63 μm and 150 μm or less is preferably 30% or more, and more preferably 50% or more.

  Moreover, the mass ratio of the iron powder having a particle size of 63 μm or less was set to 75% or less because when the content of the iron powder having a small particle size increases, the iron powder reacts rapidly with oxygen in the air, resulting in heat generation. There is a possibility that the seed coated with iron powder may be damaged or cause a fire when handling a large quantity. Furthermore, if the content of fine iron powder is large, dust is easily generated and a clean working environment is maintained. It is difficult. The mass ratio of iron powder having a particle size of 63 μm or less is preferably 70% or less.

In addition, as a more preferable content aspect of the iron powder having a particle diameter of 63 μm or less, the mass ratio of the iron powder having a particle diameter of 45 μm or less is 0% or more and 30% or less.
Iron powder having a particle diameter of 45 μm or less slips through the hair on the surface of the seed and has a strong adhesive force to adhere directly to the surface of the seed. Realized.

  The reason why the mass ratio of the iron powder having a particle diameter exceeding 150 μm is set to 50% or less is that the iron powder having a particle diameter exceeding 150 μm cannot be expected to be held by hair and directly attached to the seed surface. The purpose is to reduce things.

  In addition, the particle size distribution of iron powder can be evaluated by sieving using the method defined in JIS Z2510-2004.

  Examples of the method for producing iron powder in the present embodiment include reduced iron powder and atomized iron powder.

<Content ratio of metallic iron>
The content ratio of metallic iron in the iron powder for seed coating according to the present embodiment is 30.0 mass% or more and 99.0 mass% or less.
The reason why the content ratio of metallic iron is 30.0% by mass or more is that when the content ratio of metallic iron is less than 30.0% by mass, the amount of generated rust is small and the coating strength with iron powder becomes weak. It is preferable that it is 31.3 mass% or more.
Moreover, the content ratio of metallic iron was made 99.0% by mass or less because if the content ratio of metallic iron exceeds 99.0% by mass, the oxidation reaction at the time of rusting proceeds rapidly, and the calorific value at that time This greatly damages the seed and reduces the germination rate. It is preferable that it is 98.9 mass% or less.

Control of the content ratio of metallic iron in the iron powder for seed coating is performed as follows.
By controlling the oxygen concentration in the atmosphere in the atomizing process of iron powder, the atmospheric oxygen concentration in the reduced iron powder manufacturing process, and further the oxygen concentration and hydrogen concentration when finishing heat treatment of atomized iron powder and reduced iron powder, The degree of oxidation of the iron powder can be controlled, and consequently the content ratio of metallic iron in the iron powder can be controlled.

The method for seed coating with the iron powder for seed coating is not particularly limited.
For example, as shown in the “Iron Coating Direct Seeding Manual 2010 (edited by the National Agricultural Research Center for Agricultural and Food Industry, Kinki Chugoku Shikoku Research Center)” Any method such as a method using a known mixer may be used.
As the mixer, for example, a stirring blade type mixer (for example, a Henschel mixer) or a container rotation type mixer (for example, a V type mixer, a double cone mixer, a tilt rotation type bread type mixer, a rotary mulberry type mixer, etc.) can be used. .
Further, as shown in the iron coating soaking direct sowing manual 2010 described above, a coating reinforcing agent such as calcined gypsum can be used for iron powder coating.

According to the iron powder for seed coating of the present embodiment, retention by hair can be expected, for example, seeds such as rice seeds having hair on the seed surface, and iron powder is removed not only in the sowing process but also in the transport process. It is possible to realize a coating with a small amount of rust, and to realize a stable coating by ensuring the formation of rust.
In addition, the said effect of the iron powder for seed coating | coated which concerns on this Embodiment has been confirmed in Example 1 mentioned later.

[Embodiment 2]
In the iron powder for seed coating according to the present embodiment, the mass ratio of iron powder having a particle diameter of 63 μm or less is 0% or more and 75% or less, and the mass ratio of iron powder having a particle diameter of more than 63 μm and 150 μm or less is 25. % Or more and 100% or less, the mass ratio of the iron powder having a particle diameter exceeding 150 μm is 0% or more and 50% or less, and the fluidity is 40 (sec / 50 g) or less.
The particle size distribution is the same as in the first embodiment, and the reason for defining the particle size distribution is the same as in the first embodiment. In the following, the reason for defining the fluidity that is a feature of the present embodiment will be described.

<Fluidity>
The fluidity of the seed coating iron powder according to the present embodiment is set to 40 (sec / 50 g) or less.
The fluidity is defined in JIS Z2502: 2000 as a method for evaluating the fluidity of metals.
According to JIS Z2502: 2000, the rheometer is composed of a funnel, a funnel support, a support bar, and a support base, and the shape and dimensions of each dimension funnel are defined. Transfer 50 g of metal powder dried at 105 ± 5 ° C. to the funnel, open the orifice at the bottom of the funnel, and measure the time from the moment the orifice is opened until the last powder leaves the orifice. It evaluates that fluidity | liquidity is so favorable that said time is short.
The definition of fluidity is the time (sec) required for 50 g of powder to pass through the orifice, and the unit is (sec / 50 g).

The reason why the fluidity of the seed coating iron powder is set to 40 (sec / 50 g) or less is to reduce variation in the coating of the seed coating iron powder among the seeds.
The relationship between coating variation and fluidity will be described below.
As a method of coating seeds with iron powder for seed coating, iron powder for seed coating, calcined gypsum (calcium sulfate hydrate) and seeds are put into a rotating container, and iron powder and gypsum are sprayed on the seed surface while spraying water. Coating. In such a process, when the fluidity of the seed coating iron powder is large, adhesion unevenness occurs, and the variation in the coating of the seed coating iron powder among the seeds increases. Conversely, if the fluidity of the seed coating iron powder is small, adhesion unevenness does not occur, and the variation in coating between seeds is reduced.

The method for controlling the fluidity of the seed-coated iron powder is performed as follows.
The particle size distribution and shape of the iron powder have a great influence on the fluidity. Therefore, for example, to control the fluidity of water atomized iron powder, the particle size distribution and particle shape of the iron powder are controlled by the flow rate and diameter of the molten steel flow dropped from the nozzle, the flow rate of spray water, the flow rate and the spray angle, As a result, the fluidity can be controlled.
For reduced iron powder, the particle size distribution and particle shape of the iron powder can be controlled by selecting the raw iron oxide before reduction and the grinding method of the product after reduction. Can be controlled.

According to the iron powder for seed coating of the present embodiment, retention by hair can be expected, for example, seeds such as rice seeds having hair on the seed surface, and iron powder is removed not only in the sowing process but also in the transport process. Therefore, a stable coating can be realized by preventing variation in coating between seeds.
In addition, the said effect of the iron powder for seed coating | coated which concerns on this Embodiment has been confirmed in Example 2 mentioned later.

[Embodiment 3]
In the iron powder for seed coating according to the present embodiment, the mass ratio of iron powder having a particle diameter of 63 μm or less is 0% or more and 75% or less, and the mass ratio of iron powder having a particle diameter of more than 63 μm and 150 μm or less is 25. % To 100% and the mass ratio of the iron powder having a particle diameter exceeding 150 μm is 0% to 50%, and the angle of repose is 45 degrees or less.
The particle size distribution is the same as in the first embodiment, and the reason for defining the particle size distribution is the same as in the first embodiment. In the following, the reason for defining the angle of repose, which is a feature of the present embodiment, will be described.

<Repose angle>
The angle of repose of the iron powder for seed coating according to the present embodiment is set to 45 degrees or less.
The angle of repose is the angle of the slope that maintains stability without spontaneous collapse when the seed coating iron powder is stacked, and the higher the fluidity, the smaller the angle of repose.
The reason why the angle of repose of the iron powder for seed coating is set to 45 degrees or less is to reduce the variation in the coating of the iron powder for seed coating between the seeds.

The relationship between the coating variation and the angle of repose will be described below.
As a method of coating seeds with iron powder for seed coating, iron powder for seed coating, calcined gypsum (calcium sulfate hydrate) and seeds are put into a rotating container, and iron powder and gypsum are sprayed on the seed surface while spraying water. Coating. In such a process, if the angle of repose of the iron powder for seed coating is large and the fluidity is low, uneven adhesion occurs, and the dispersion of the coating of the iron powder for seed coating between the seeds increases. Conversely, if the angle of repose of the iron powder for seed coating is small and the fluidity is high, uneven adhesion does not occur and the variation in coating between seeds is reduced.

The method for controlling the angle of repose of the iron powder for seed coating is as follows.
The particle size distribution and shape of the iron powder have a great influence on the angle of repose. Therefore, for example, in order to control the angle of repose for water atomized iron powder, the particle size distribution and particle shape of iron powder are controlled by the flow velocity and diameter of the molten steel flow dropped from the nozzle, the flow rate of spray water, the flow velocity and the spray angle, As a result, the angle of repose of the iron powder can be controlled.
For reduced iron powder, the particle size distribution and particle shape of the iron powder can be controlled by selecting the raw iron oxide before reduction and the grinding method of the product after reduction. As a result, the angle of repose of the iron powder is controlled. Can be controlled.

According to the iron powder for seed coating of the present embodiment, retention by hair can be expected, for example, seeds such as rice seeds having hair on the seed surface, and iron powder is removed not only in the sowing process but also in the transport process. Therefore, a stable coating can be realized by preventing variation in coating between seeds.
In addition, the said effect of the iron powder for seed coating | coated which concerns on this Embodiment has been confirmed in Example 3 mentioned later.

  Since the experiment which confirms the effect of the iron powder for seed coating | coated shown to this Embodiment 1-3 was demonstrated in the following Examples 1-3.

Regarding the iron powder for seed coating according to the first embodiment, an experiment for confirming the effect of the particle size distribution was conducted.
Rice seeds were coated using Invention Examples 1 to 9, which are iron powders having various particle size distributions as Invention Examples. Moreover, as a comparative example, rice seeds were coated using Comparative Examples 1 to 4 which are iron powders having a particle size distribution outside the range of the particle size distribution of the present invention.
In addition, the metal iron content ratios of Invention Examples 1 to 9 and Comparative Examples 1 to 4 were controlled to be substantially constant 88% by mass.

Iron powder coating (coating) was performed according to the method described in the above-mentioned “Iron Coating Direct Sowing Manual 2010”. Specifically, it is as follows.
First, seed candy, calcined gypsum and several types of iron powder were prepared. Next, 5 kg of iron powder and 0.5 kg of calcined gypsum are coated on 10 kg of seed (seed seed) while spraying an appropriate amount of water using an inclined rotary type bread mixer, and further 0.25 kg of calcined gypsum Coated to finish.
A method for evaluating the strength of the coating film against rolling friction and sliding friction of seed coated with iron powder has not been established.
Therefore, the coating strength was investigated in accordance with the test method described in JPMA P 11-1992 “Method for measuring the Latra value of metal compact”. This test method will be referred to as a ratra test.

In the ratra test, 20 ± 0.05 g of seed coated with iron powder was enclosed in a rattle tester cage, and the cage was rotated 1000 times at a rotation speed of 87 ± 10 rpm. According to this method, rolling and sliding frictional forces are applied between the seeds and between the seeds and the inner surface of the basket container as the seeds flow while rolling in the basket.
Therefore, when this method is applied, the strength of the coating film when the rolling friction force and the sliding friction force are applied in combination can be evaluated.
Table 2 shows the particle size distribution of the iron powder and the weight reduction rate in the ratra test. The weight reduction rate was obtained from the following calculation formula.
Weight reduction rate = (mass of coating peeled off in ratra test) / (mass of seed before test) × 100 (%)
Therefore, it can be determined that the smaller the weight reduction rate, the higher the strength of the coating.

As shown in Table 2, all of the examples described in Invention Examples 1 to 9 are “the mass ratio of the iron powder having a particle diameter of 63 μm or less is 0% or more and 75% or less, and the particle diameter is more than 63 μm and 150 μm or less. Is within the range of the particle size distribution of the present invention, wherein the mass ratio of the iron powder is 25% or more and 100% or less and the mass ratio of the iron powder having a particle diameter of more than 150 μm is 0% or more and 50% or less. The weight reduction rate is less than 4%.
On the other hand, in Comparative Examples 1 to 4 outside the above range of the particle size distribution, the weight reduction rate in the ratra test is 4% or more.
From this, it was demonstrated that the weight reduction rate can be significantly suppressed by making the particle size distribution of the iron powder within the range of the present invention.
In Table 2, the numbers whose particle size distributions in Comparative Examples 1 to 4 are outside the scope of the present invention are underlined.

  In Invention Examples 1, 2, 3, 4, and 6, the mass ratio of the iron powder having a particle diameter of more than 63 μm and 150 μm or less is 50% or more and the mass ratio of the iron powder of 45 μm or less is 30% or less. Since the weight reduction rate in the ratra test is as low as 3.5% or less, the mass ratio of the iron powder having a particle diameter exceeding 63 μm and 150 μm or less is increased, and the iron powder having a particle diameter of 45 μm or less. It can be seen that the adhesion of the iron powder can be increased by reducing the mass ratio.

Next, in order to confirm the effect of defining the metal iron content ratio of the seed coating iron powder according to Embodiment 1 to a predetermined value, as an example of the invention, the particle size distribution is within the scope of the present invention, and the metal iron content ratio Rice seeds were coated using Invention Examples 10 to 14 having an amount of 30.0% by mass to 99.0% by mass.
Further, as comparative examples, the particle size distribution is within the scope of the present invention, but the ratio of metallic iron outside the scope of the invention is 20.8% by mass of comparative example 5 and 99.3% by mass of comparative example 6. Rice seeds were coated.
In this experiment, since the main purpose was to confirm the effect on the content ratio of metallic iron, the particle size distribution was controlled to be almost the same.
Table 3 shows the particle size distribution of the iron powder for seed coating, the metal iron content ratio, the weight reduction rate in the ratra test, and the germination rate.
In addition, the germination rate was evaluated according to the “germination test” described in the iron-coated flooded direct seeding manual 2010 described above. Specifically, about 100 seeds and 20 mL of water were placed in a 9 cm diameter petri dish, and the seeds that were not germinated seeds were counted after standing at 25 ° C. for 1 week, and the germination rate was calculated.

  In Invention Examples 10-14, when the metal iron content ratio is arranged in descending order, Invention Examples 11, 10, 14, 12, 13 are obtained. When the weight reduction rate in these ratra tests is seen, the above order is the weight reduction. The order is from the one with the lowest rate. From this, it can be inferred that by increasing the content ratio of metallic iron, the occurrence of rust could be ensured and the strength of the coating could be increased.

On the other hand, in Comparative Example 5, the content ratio of metallic iron is as small as 20.8% by mass, and as a result, the weight reduction rate in the Latra test is as high as 21.3%. From this, it is surmised that since the metal iron content ratio is low outside the scope of the invention, the occurrence of rust is insufficient and the coating strength is lowered.
Moreover, in the comparative example 6 whose metal iron content rate is 99.3% by mass, the weight reduction rate in the ratra test is not as high as 3.2%, but the germination rate is as low as 63%. This is presumed that the oxidation reaction at the time of the occurrence of rust progresses rapidly, and the amount of heat generated at that time is large, causing damage to the seeds.

  As described above, it is confirmed that the coating with high coating strength can be realized without damaging the seeds by setting the metal iron content ratio of the iron powder for seed coating to 30.0 mass% or more and 99.0 mass% or less. It was done.

Experiments were conducted for the case where the fluidity of the iron powder for seed coating according to Embodiment 2 was within the scope of the invention and the particle size distribution was changed in the same manner as in Example 1.
Table 4 shows the particle size distribution of the iron powder and the weight reduction rate in the ratra test.

The particle size distribution in Invention Examples 15 to 23 is substantially the same as that of Invention Examples 1 to 9 of Example 1, and the particle size distribution in Comparative Examples 7 to 10 is substantially the same as that of Comparative Examples 1 to 4 of Example 1.
Regarding the fluidity, both the inventive example and the comparative example were controlled to 40 (sec / 50 g) or less, which is the scope of the invention, specifically, 26.5 (sec / 50 g) to 39.5 (sec / 50 g). did.
The rice seed coating method with iron powder, the ratra test method and the like are the same as those shown in Example 1.

  As shown in Table 4, the weight reduction rate was the same as the result shown in Table 2 of Example 1, and it was confirmed that the influence of the particle size distribution was large on the weight reduction rate. That is, when the particle size distribution is within the scope of the invention, the adhesion of iron powder to rice seeds can be increased.

Next, in order to confirm the effect of the fluidity of the iron powder for seed coating according to the present invention, as an example of the present invention, the particle size distribution is within the scope of the present invention and the fluidity is 30.5 (sec / 50 g). ) Rice seeds were coated using Invention Examples 24-26 of 35.0 (sec / 50 g) and 40.0 (sec / 50 g).
Further, as comparative examples, the particle size distribution is within the scope of the present invention, but the comparative example 11 has a very high fluidity, and the comparative example 12 has no iron powder coating.
Table 5 shows the average mass (mg) and standard deviation (mg) of the iron powder-coated seed mass (100 grains) and the germination rate (%) corresponding to the particle size distribution and fluidity of the seed-coated iron powder. The method for evaluating the germination rate is the same as that shown in Example 1.

As Table 5 shows, the thing of invention example 24-26 has the standard deviation (mg) of iron powder coating seed mass (100 grains) smaller than 11 (mg). It can also be seen that the smaller the fluidity, the smaller the standard deviation. And the thing of invention examples 24-26 has a germination rate of 95% or more, and is quite high. In particular, when the fluidity is 35 (sec / 50 g) or less, the standard deviation is 7.2 (mg) or less and the germination rate is 99% or more.
On the other hand, the thing of the comparative example 11 has a standard deviation exceeding 15 (mg), and the germination rate is as low as 85%.
From the above, it can be seen that by reducing the fluidity of the seed coating iron powder, the variation in coating of the seed coating iron powder on the seed is reduced, and the germination rate is increased.
Further, if the fluidity is 40 (sec / 50g) or less, the germination rate is preferably 95% or more, and if the fluidity is 35 (sec / 50g) or less, the germination rate is 99% or more. It turns out that it is more preferable.

Experiments were conducted for the case where the repose angle of the iron powder for seed coating according to Embodiment 3 was within the invention range and the particle size distribution was changed in the same manner as in Example 1.
Table 6 shows the particle size distribution of the iron powder and the weight reduction rate in the ratra test.

The particle size distribution in Invention Examples 27 to 35 is substantially the same as that of Invention Examples 1 to 9 of Example 1, and the particle size distribution in Comparative Examples 13 to 16 is substantially the same as that of Comparative Examples 1 to 4 of Example 1.
In addition, the angle of repose was controlled to 45 degrees or less, which is the scope of the invention in both the inventive example and the comparative example, specifically 31 to 45 degrees.
The rice seed coating method with iron powder, the ratra test method and the like are the same as those shown in Example 1.

  As shown in Table 6, the weight reduction rate was the same as the result shown in Table 2 of Example 1, and it was confirmed that the influence of the particle size distribution was large regarding the weight reduction rate. That is, when the particle size distribution is within the scope of the invention, the adhesion of iron powder to rice seeds can be increased.

Next, in order to confirm the effect of defining the angle of repose of the iron powder for seed coating according to the present invention, as an example of the present invention, the particle size distribution is within the range of the present invention, and the angle of repose is 34 degrees and 40 degrees. The rice seeds were coated using Inventive Examples 36 to 38 at 45 degrees.
Further, as comparative examples, the particle size distribution is within the scope of the present invention, but comparative example 17 having an angle of repose of 47 degrees and comparative example 18 without iron powder coating were used.
Table 7 shows the average particle size (mg) and standard deviation (mg) of the iron powder-coated seed mass (100 grains) and the germination rate (%) corresponding to the particle size distribution and angle of repose of the seed-coated iron powder. The method for evaluating the germination rate is the same as that shown in Example 1.

As shown in Table 7, those described in Invention Examples 36 to 38 have a standard deviation (mg) of the iron powder-coated seed mass (100 grains) smaller than 11 (mg). It can also be seen that the smaller the angle of repose, the smaller the standard deviation. And the thing of invention examples 36-38 has a germination rate of 95% or more, and is quite high. In particular, if the angle of repose is 40 degrees or less, the standard deviation is 7.2 (mg) or less and the germination rate is 99% or more.
In contrast, in Comparative Example 17, the standard deviation exceeds 15 (mg) and the germination rate is as low as 85%.
From the above, it can be seen that by reducing the angle of repose of the iron powder for seed coating, the variation of the coating of the iron powder for seed coating on the seed is reduced and the germination rate is increased.
In addition, it can be seen that if the angle of repose is 45 degrees or less, the germination rate is 95% or more, and more preferably if the angle of repose is 40 degrees or less, the germination rate is 99% or more.

1 seed rice 3 rice husk 5 hair

Claims (8)

Iron powder used to coat seeds,
The mass ratio of iron powder having a particle diameter of 63 μm or less is 0% or more and 75% or less, the mass ratio of iron powder having a particle diameter of more than 63 μm and 150 μm or less is 25% or more and 100% or less, and the particle diameter exceeds 150 μm. An iron powder for seed coating, wherein the mass ratio of iron powder is 0% or more and 50% or less, and the content ratio of metallic iron is 30.0 mass% or more and 99.0 mass% or less. Iron powder used to coat seeds,
The mass ratio of iron powder having a particle diameter of 63 μm or less is 0% or more and 75% or less, the mass ratio of iron powder having a particle diameter of more than 63 μm and 150 μm or less is 25% or more and 100% or less, and the particle diameter exceeds 150 μm. An iron powder for seed coating, wherein the mass ratio of the iron powder is 0% or more and 50% or less and the fluidity is 40 (sec / 50 g) or less. Iron powder used to coat seeds,
The mass ratio of iron powder having a particle diameter of 63 μm or less is 0% or more and 75% or less, the mass ratio of iron powder having a particle diameter of more than 63 μm and 150 μm or less is 25% or more and 100% or less, and the particle diameter exceeds 150 μm. An iron powder for seed coating, wherein the mass ratio of the iron powder is 0% or more and 50% or less, and the angle of repose is 45 degrees or less.   The iron powder for seed coating according to any one of claims 1 to 3, wherein a mass ratio of iron powder having a particle diameter of 45 µm or less is 0% or more and 30% or less.   The iron powder for seed coating according to any one of claims 1 to 4, wherein a mass ratio of the iron powder having a particle diameter of more than 63 µm and not more than 150 µm is 50% or more.   The iron powder for seed coating according to any one of claims 1 to 5, wherein the iron powder is produced by a reduction method or an atomization method.   A seed obtained by coating a seed with the iron powder for seed coating according to any one of claims 1 to 6.   The seed according to claim 7, wherein the seed is a rice seed.

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