JP2982933B2 - Fertilizer coating composition and coated granular fertilizer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating composition for a coated granular fertilizer and a coated granular fertilizer capable of supplying an appropriate amount of nutrients at a necessary time for a crop by coating the surface of the granular fertilizer with a water-resistant resin.

[0002]

BACKGROUND OF THE INVENTION Chemical fertilizers are generally water-soluble and are therefore fast-acting. But,
Due to its water solubility, component loss (decrease in utilization rate) due to runoff, denitrification, etc. is large, and it is difficult to maintain the fertilizing effect for a long period of time. In addition, there is a possibility that a local imbalance at the time of fertilization may cause concentration disturbance to agricultural products.

[0003] One of the fertilization methods that do not cause concentration disturbance to agricultural products is the application of a coated fertilizer. The coated fertilizer is a fertilizer in which the surface of a granular fertilizer is coated with an organic or inorganic coating material to control the elution of the internal fertilizer components. Among them, an organic coating material using a resin or the like is effective in terms of the component control function, and occupies the mainstream.

[0004] After the elution of fertilizer is completed for all of these materials, most of the coating materials remain in the soil for a long time, imposing a burden on the ecosystem environment. In particular, in recent years, with the rise of eco-friendly eco-friendly agriculture, it is required that the coating material used for the coated fertilizer be decomposed in the soil as soon as possible after the fertilizing component elutes. However, since organic solvents are generally used in the production of coated fertilizers using organic coating materials using alkyd resins and the like known as biodegradable types, sufficient attention and measures are required for their toxicity, flammability, etc. . In particular, in recent years, with the rise of environmental problems, recovery of solvents, environmental pollution, and the like have been raised. Therefore, in order to solve such a problem, a coating material capable of obtaining a coated granular fertilizer without using an organic solvent having a problem of recovery and environmental pollution was studied. It was not always satisfactory in terms of elution control.

[0005]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above problems, and have found that a mixture of an alkyd resin and a glycerin rosin ester (improved water resistance and adhesion to fertilizer) and boil oil By mixing (improvement of film forming property), a water-resistant coating material excellent in film forming property was found, and the present invention was reached.

That is, the present invention relates to a fertilizer coating composition comprising an oil-modified alkyd resin, an unsaturated oil having a conjugated double bond in the molecule and a glycerin rosin ester, or a boil oil. The present invention provides a coated granular fertilizer coated on the outer layer of the present invention.

The oil-modified alkyd resin used in the present invention is a polybasic acid such as phthalic anhydride or maleic anhydride, a polyhydric alcohol such as pentaerythritol or glycerin, and a natural vegetable oil or vegetable fat or natural animal fat as a denaturant. A general product obtained by heat condensation may be used, and the type thereof is not particularly limited.

[0008] Examples of natural vegetable oils or vegetable fats include
Examples include soybean oil, linseed oil, tung oil, surfflower oil, coconut oil, palm oil and the like. Natural animal oils include, for example, beef tallow. The molecular weight is preferably in the range of 500 to 5000. When the molecular weight is less than 500, the film formed by the reaction with the unsaturated oil is brittle, and the curing and drying speed is slow, so that it takes a long time to form the film. On the other hand, when the molecular weight is 50
If it exceeds 00, the viscosity becomes high and it is difficult to efficiently and uniformly form a coating.

Examples of the unsaturated oil having a conjugated double bond in the molecule include tung oil and dehydrated castor oil. Tung oil is mainly composed of eleostearic acid having a conjugated double bond. Dehydrated castor oil is rich in 9,11 linoleic acid with conjugated double bonds. These tung oil, dehydrated castor oil and the like can be used as they are or by purifying the target components.

[0010] These unsaturated oils have the effect of diluting the alkyd resin to lower the viscosity and, in addition, crosslink the unsaturated oils with each other or the alkyd resin in the presence of a metal soap to form a resin (solidify).

The mixing ratio of the above oil-modified alkyd resin and unsaturated oil is usually preferably in the range of 2: 8 to 7: 3 by weight. When the proportion of the oil-modified alkyd resin is less than this range, the purified coating is brittle and has poor water resistance. If the ratio of the oil-modified alkyd resin is larger than this range,
It is difficult to coat efficiently because the viscosity is too high.

As the metal soaps, naphthenic acids or octylic acids such as manganese, cobalt, zirconium, nickel, iron and lead can be used. For example, zirconium octylate, manganese naphthenate, cobalt octylate alone or a mixture thereof can be used, and the amount thereof is 0.5 to the total of the oil-modified alkyd resin and the unsaturated oil.
A range of 3% by weight is preferred. Below this, the reaction speed is slow, and above this, uniform film formation becomes difficult.

The rosin acid glycerin ester is obtained by heating gum rosin, wood rosin, tall oil rosin, glycerin, polyglycerin and glycerin pitch under normal pressure. The addition amount of rosin acid glycerin ester is preferably in the range of 5 to 25% by weight of the total of the mixture of the oil-modified alkyd resin and the unsaturated oil. Below this, the expected effect cannot be obtained. On the other hand, if it is more than this, it is difficult to form a uniform film because the viscosity is too high, resulting in poor water resistance.

[0014] Boil oil is obtained by heating a drying oil under normal pressure to give an appropriate consistency, decolorizing, and adding a drying agent to improve drying properties. Examples of the drying oil include linseed oil, eno oil, Tung oil, hemp oil, soybean oil, sardine oil. The amount of the boil oil added is preferably in the range of 10 to 40% by weight of the total of the mixture of the oil-modified alkyd resin, the unsaturated oil and the glycerin rosin ester. Below this, the minimum film thickness of the film is small, making it difficult to form a film, resulting in poor water resistance. On the other hand, if it is more than this, the curing speed becomes slow, and it takes a long time to form a coating film.

In a fertilizer coating composition comprising an oil-modified alkyd resin, an unsaturated oil having a covalent double bond in the molecule, and a rosin acid ester, the compounding composition is such that the amount of the rosin acid ester added is the same as that of the oil-modified alkyd resin. A range of 5 to 25% by weight of the total of the mixture with the unsaturated oil is preferred. Below this, the expected effect cannot be obtained. On the other hand, if it is more than this, it is difficult to form a uniform film because the viscosity is too high, resulting in poor water resistance. Oil-modified alkyd resin, unsaturated oil having a conjugated double bond in the molecule, a fertilizer coating composition comprising rosin acid ester and boil oil, the amount of boil oil added oil-modified alkyd resin and unsaturated oil and The range of 10 to 40% by weight of the total with the rosin acid ester is preferred. Below this, the minimum film thickness of the film is small and the film formability is difficult, resulting in poor water resistance. On the other hand, if it is more than this, the curing speed becomes slow, and it takes a long time to form a coating film.

The fertilizer to be coated in the present invention may be a commonly used simple fertilizer such as salt ammonium, urea or chloride, compound fertilizer such as NK chemical, phosphoric acid phosphorus and phosphorus nitrate, and granular organic fertilizer.
There is no particular limitation. Further, as the coating method, as is well known, each of a rolling type such as a fluidized bed and a rotating drum may be used.

[0017]

The present invention will now be described in detail with reference to Examples.
It is not limited to such an embodiment.

Example 1 In a fluidized-bed apparatus having a tower diameter of 10 cm, the average particle diameter was 3.3 mm.
Of urea was charged, and hot air was fed from the lower part at 70 m ³ / Hr to flow and maintained at 80 ° C. On the other hand, 6
Two fluids of an alkyd coating material (30 parts by weight of a 60% soybean oil-modified alkyd resin, 50 parts by weight of tung oil, 3 parts by weight of a metal soap, and 2 parts by weight of an anti-skinning agent) heated to 0 ° C. and 15 parts by weight of rosin acid glycerin ester 1.7 g /
The spray was sprayed onto the fertilizer granules at a speed of min to obtain a coated granular fertilizer having a constant film thickness. Similarly, a coating material having the composition shown in Table 1 was sprayed to obtain a coated granular fertilizer having a constant film thickness. The coverage was 11%.

Here, the coverage is a ratio obtained by dividing the total weight of the alkyd-based coating material and glycerin rosin acid ester by the total weight of the alkyd-based coating material, glycerin rosin acid ester and fertilizer. The same applies to the following embodiments. The average molecular weight of the 60% soybean oil-modified alkyd resin used in Example 1 was 3000, and the metal soap was zirconium octylate, cobalt octylate,
Manganese naphthenate mixed at a weight ratio of 6: 3: 1 was used. In addition, dibutylhydroxytoluene was used as the anti-skinning agent.

[0020]

[Table 1]

The obtained coated granular fertilizer was subjected to a nitrogen (N) dissolution test. The results are shown in Table 2. The measurement of this dissolution rate is carried out by putting the coated granular fertilizer into a certain amount of water and heating at 25 ° C.
After leaving for a certain period of time, the fertilizer and the solution are separated, and the amount of nitrogen eluted in water is determined and determined.

[0022]

[Table 2]

Example 2 A fluidized-bed apparatus having a tower diameter of 10 cm had an average particle diameter of 3.1 mm.
Nitrogen Kari Kasei C20 (N: 20%, K ₂ O: 10
%), And heated at 70 m ³ / Hr from below to flow and maintain the temperature at 105 ° C. On the other hand, 6
A coating material having the composition shown in Table 3 heated to 0 ° C. was sprayed onto the fertilizer granules at a rate of 1 g / min using a two-fluid nozzle to obtain a coated granular fertilizer having a constant film thickness. Its coverage was 9%. The composition of the alkyd coating material is the same as in Example 1.

[0024]

[Table 3]

The obtained coated granular fertilizer is nitrogen (N)
Was subjected to a dissolution test. Table 4 shows the results. The measurement of the dissolution rate is in accordance with Example 1.

[0026]

[Table 4]

Example 3 Table 5 shows the results of a film forming property and a water permeability test of the coating material used in Example 1. The film forming property and water permeability test method are shown below.

(1) Test Method for Film Formability The alkyd-based coating material and rosin acid glycerin ester mixture are sufficiently stirred with a homomixer to form a uniform solution. The solution was placed on a glass plate (15 cm ×
7 cm) and dried at 90 ° C. for 1 hour. After drying, the state of film formation on the glass plate was visually observed.

(2) Water Permeability Test Method Preparation of PVA Film A PVA film is cut into 16 cm × 8 cm. A glass plate (15 cm × 7
cm) at both ends with adhesive tape. Coating method Apply to the PVA film surface with a 25 μm applicator. Drying The applied PVA film is dried at 90 ° C. for 1 hour. Water Permeability After drying, water droplets are dropped on the surface of the applied PVA film, and the water permeation time is measured.

[0030]

[Table 5]

Example 4 Tung oil in the alkyd-based coating material used in C of Example 1 was partially replaced with boil oil, and a test for the minimum film thickness and water permeability of a coating film using boil oil was conducted. Table 6 shows the mixing ratio of tung oil and boil oil in the alkyd coating material and the results.

The method for measuring the minimum film thickness and the method for testing the water permeability are shown below. (1) Method for measuring minimum film thickness A mixture of the coating material and boil oil is sufficiently stirred with a homomixer to form a uniform solution. The solution was applied to a glass plate (15 cm × 7 cm) with a 50 μm applicator,
Dry for 0 minutes. After drying, the minimum thickness of the coating film on the glass plate was measured with a surface roughness meter.

(2) Test Method for Water Permeability According to Example 3.

[0034]

[Table 6]

Example 5 In a fluidized-bed apparatus having a tower diameter of 10 cm, the average particle diameter was 3.3 mm.
Of urea was charged, and hot air was fed from the lower part at 70 m ³ / Hr to flow and maintained at 80 ° C. On the other hand, 6
85 parts by weight of the alkyd-based coating material prepared in Example 4 heated to 0 ° C. and 15 parts by weight of rosin acid glycerin ester were sprayed onto fertilizer granules at a rate of 1.7 g / min using a two-fluid nozzle to be constant. A coated granular fertilizer with a film thickness was obtained. The coverage was 11%.

The coated granular fertilizer thus obtained was subjected to a nitrogen (N) dissolution test. The compounding ratio of tung oil and boil oil as the coating material is the same as in Example 4. Table 7 shows the results. The measurement of the dissolution rate is in accordance with Example 1.

[0037]

[Table 7]

Example 6 An average particle diameter of 3.1 mm was applied to a fluidized-bed apparatus having a tower diameter of 10 cm.
Nitrogen Kari Kasei C20 (N: 20%, K ₂ O: 10
%), And heated at 70 m ³ / Hr from below to flow and maintain the temperature at 105 ° C. On the other hand, 6
85 parts by weight of the alkyd coating material prepared variously in Example 4 heated to 0 ° C. and 15 parts by weight of rosin acid glycerin ester were sprayed onto fertilizer grains at a rate of 1 g / min using a two-fluid nozzle to obtain a constant film thickness. To obtain a coated granular fertilizer. The coverage was 9%.

The obtained coated granular fertilizer was subjected to a nitrogen (N) dissolution test. The compounding ratio of tung oil and boil oil as the coating material is the same as in Example 4. Table 8 shows the results. The measurement of the dissolution rate is in accordance with Example 1.

[0040]

[Table 8]

[0041]

Since the coating composition of the present invention does not contain an organic solvent, there is no danger of flammability or the like, and there is no problem of environmental pollution. Further, by using the coating composition of the present invention, the dissolution rate of the granular fertilizer can be adjusted, and the fertilizer effect can be maintained for a long time.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Sadaharu Misumi 5253 Oki Ube, Oji, Ube City, Yamaguchi Prefecture Inside the Ube Laboratory, Central Glass Co., Ltd. (72) Inventor Hiroshi Hotta 6-10-3 Minamitsukaguchicho, Amagasaki City, Hyogo Prefecture Inside Shinto Paint Co., Ltd. (72) Osamu Kondo 6-10 Minamitsukaguchicho, Amagasaki City, Hyogo Prefecture No. 73 in Shinto Paint Co., Ltd. (56) References JP-A-5-4887 (JP, A) JP-A-1-108188 (JP, A) JP-A-54-66260 (JP, A) JP-A Sho 49-24752 (JP, A) JP-A-7-69770 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C05G 3/00 103 C05G 5/00

Claims (3)

(57) [Claims] 1. A fertilizer coating composition comprising an oil-modified alkyd resin, an unsaturated oil having a conjugated double bond in the molecule, and glycerin rosinate. 2. A fertilizer coating composition comprising an oil-modified alkyd resin, an unsaturated oil having a conjugated double bond in the molecule, glycerin rosin ester and boil oil. 3. A coated granular fertilizer wherein the surface of the granular fertilizer is mainly coated with a mixture of an oil-modified alkyd resin, an unsaturated oil having a double bond in a molecule, a glycerin rosinate, and boil oil.