JPS5946915B2 - molded fertilizer - Google Patents

Description

[Detailed description of the invention] The present invention relates to shaped fertilizers.

Specifically, the present invention relates to a molded fertilizer that is easy to mold and has excellent slow-release properties and contains nitrogen, potassium, or both and phosphorus.

A slow-release molded fertilizer containing nitrogen, potassium, and phosphorus is produced by compression molding powdered imbutylidene diurea, a condensate of aldehyde and urea, potassium phosphate fertilizer, and mineral heavy oil. A molded fertilizer is known (Japanese Unexamined Patent Publication No. 134867/1986).

Molded fertilizer using this potassium phosphate fertilizer has excellent product hardness and drop strength, but it is prone to cracks (partial openings due to poor compression of raw materials) and defects during molding, and in general, potassium phosphate fertilizer is Because it is more easily soluble in water than imbutylidene diurea, there is a difference in the elution of fertilizing ingredients, and as a result, the slow-release properties of isobutylidene diurea tend to decrease slightly. However, improvements were desired.

As a result of extensive research in order to meet the above requirements, the present inventors have developed a method of using potassium silicate fertilizer as a potassium source, and using granular and mineral-based nitrogen fertilizer, which is a reaction product of aldehyde and urea and is sparingly soluble in water. When compression molding with heavy oil,
The present invention was completed by learning that it is possible to obtain a molded fertilizer that is easy to mold and has excellent slow release properties.

That is, the present invention aims to provide a slow-release molded fertilizer of excellent quality, and its gist is that water, which is a reaction product of an aldehyde having 4 or less carbon atoms and urea, is This is a molded fertilizer made by compressing and molding poorly soluble nitrogen fertilizer powder, potassium silicate fertilizer, and mineral heavy oil.

The present invention will be explained in detail below.

The poorly water-soluble nitrogen fertilizer used in the present invention, which is a reaction product of an aldehyde having 4 or less carbon atoms and urea, includes isobutyraldehyde, normal butyraldehyde, propionaldehyde, crotonaldehyde, acetaldehyde,
It is obtained by reacting an aldehyde having a carbon number of 4 or less, such as formaldehyde, or a mixture thereof with urea, and specifically, imbutylidene diurea, normal butylidene diurea, propylidene diurea, and tarotonylidene. Examples include diurea, ethylidene diurea, and a condensate of formaldehyde and urea that has the same solubility in water as isobutylidene diurea.A typical example is isobutylidene, which is commercially available as a slow-release fertilizer. Examples include powders such as diurea and crotonylidene diurea.

It is preferable to adjust the moisture content of the powder to about 1 to 15% by weight, preferably about 3 to 10% by weight, because compression molding is easy and a good product can be obtained.

Potassium silicate fertilizer is made from coal ash such as pulverized coal combustion ash (fly ash) or silica-alumina containing minerals with a similar composition, and is mixed with a potassium source such as potassium carbonate, potassium hydroxide, etc. 600~900'
It is obtained by reacting at a temperature of about C, and examples include the potassium silicate fertilizer described in "Fertilizer Yearbook, 1974 Edition," published by the Fertilizer Association Newspaper Department, January 20, 1978, page 289. .

The amount of potassium silicate fertilizer to be used is determined depending on the active ingredient ratio of the intended molded fertilizer, but as K2O, it is less than 2 times the total nitrogen (T-N) in the water-insoluble nitrogen fertilizer, preferably 0. The amount is preferably about 2 to 1.0 times the weight.

Examples of the mineral heavy oil include heavy oils such as C heavy oil and Minas heavy oil, spindle oils, dynamo oils, turbine oils, machine oils, mobile oils, liquid paraffin oils, and their analogs.

These mineral heavy oils are used by adding one or more of them to the raw material powder or by spraying them into the mold section of a molding machine during compression molding.

The amount added is 1 to 8% by weight, preferably 2 to 5% by weight based on the raw material powder.

If the amount is too small, the molding yield will decrease and the shape retention of the obtained molded fertilizer in water will decrease, making it impossible to obtain a molded fertilizer with excellent slow release properties.

On the other hand, if too much is used, the fertilizer effect will decrease, which is not preferable.

In addition, if inorganic salts of ligninsulfonic acid such as shrimp calcium salt, asphalt, or resins such as polyvinyl alcohol, rubber latex, vinyl acetate resin, petroleum resin, and coumaron resin are used together with the above mineral heavy oil, is preferable because it can improve the molding yield and provide a product with excellent strength and appearance.

The volume of the shaped fertilizer is usually 5 to 100 cf1i, preferably 10 to 30 cf1i, considering the sustainability of fertilizer effect and formability.
It is better to set it to cA.

In addition, the hardness of molded fertilizer varies depending on its shape and volume, but if it is too small, its shape retention will be poor and sufficient slow-release properties will not be obtained, and it will powder or crumble when handled, so the hardness To 2! ? It is preferable to select molding conditions that result in a pressure of /cwb or more (compressive fracture pressure measured by a Honya type fracture hardness tester).

The shaped fertilizer of the present invention includes the above-mentioned poorly water-soluble nitrogen fertilizer,
In addition to potassium silicate fertilizer, a slow-release molded fertilizer containing nitrogen, phosphoric acid, and potassium can be made by incorporating phosphoric acid fertilizers such as calcined phosphorous fertilizer, melted phosphorous fertilizer, heavy calcined phosphorus, and phosphate rock as a phosphorus component. Moreover, the physical properties of the shaped fertilizer can be improved.

Among these phosphoric acid fertilizers, heavy calcined phosphorus is different from calcined phosphorous fertilizers and melted phosphorous fertilizers, and even when compression molded together with nitrogen fertilizers that are poorly soluble in water and mineral heavy oil, heavy calcined phosphorus tends to adhere to the molding machine. It was difficult to form, and it was necessary to use basic substances such as hydroxides, carbonates, and oxides of alkali metals or alkaline earth metals (Japanese Patent Application No. 53-2456-Japanese Patent Publication No. 56-5719). ), in the combination of the water-insoluble nitrogen fertilizer, potassium silicate fertilizer, and mineral heavy oil of the present invention, compression molding can be easily performed even if heavy sintered phosphorus is contained without using a basic substance in combination. I can do it.

The amount of phosphoric acid fertilizer to be used is determined by the active ingredient ratio of the intended molded fertilizer. The amount is preferably about 0.05 to 0.6 times the weight, preferably about 0.05 to 0.6 times the weight.

The molded fertilizer of the present invention has no inconveniences such as cracking or chipping during production, can be easily molded, has a good appearance, and has excellent product hardness and drop strength.

In addition, the potassium silicate fertilizer used in the present invention is itself a slow-release potassium fertilizer, and has a similar elution to that of nitrogen fertilizers that are poorly soluble in water. Since it does not reduce the slow-release properties of poorly soluble nitrogen fertilizers, it can maintain its fertilizing effect over a long period of time, and there is no initial salt concentration problem, making it suitable for forestry, fruit trees, tea trees, etc.
It is of great value for use in garden crops, lawns, etc.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof.

In the Examples, "part" and "part" indicate "part by weight" and "1% by weight", respectively.

In addition, hardness, drop strength, nitrogen elution rate, and withering rate were measured by the following methods.

(1) Hardness Compressive fracture pressure was measured using a Honya type fracture hardness tester.

(2) Pack the drop strength product 15 into a bag and place it on the concrete floor at a height of 1.
．． The weight ratio of the crushed material to the product when it is allowed to fall naturally from 5 m twice.

(3) Nitrogen elution rate: Bury the sample 10 cI'rL below the ground surface (field conditions),
Five samples were collected from each area at the specified time, and the amount of eluted nitrogen was calculated from the amount of residual nitrogen.

(4) Damage rate: 1/2500 a After filling sandy loam to the second minute of a Wagner pot, add 30 g of the sample as T-N, and plant one 3rd year Ayaga on top of it using sandy loam. Prepare 10 plants, and after planting, check the number of dead plants at the specified time.
The percentage of dead plants was defined as the mortality rate.

Example 1 and Comparative Example 1 43.8 parts of imbutylidene diurea powder (manufactured by Mitsubishi Chemical Corporation, registered trademark IBDU) with a particle size of 0.7 to 2 mm and a moisture content of approximately 6%, potassium silicate fertilizer (Made by Power Development ■,
T 5t0237.5%yT K2O21.6%,
29.1 parts (product containing 2021.3% of C-), 17.6 parts of calcined phosphorous fertilizer (manufactured by Onoda Chemical Industry ■, 36 calcined phosphorous fertilizer), Minas heavy oil (JIS standard Type 3 No. 2, commonly known as C heavy oil No. 2) ) and 5 parts of a 16% aqueous solution of polyvinyl alcohol (manufactured by Nippon Gosei ■, trade name Gohsenol NH-18) were stirred and mixed, using a pouring type (34 x 34 x 20 mm, volume: 15.4 c4) briquetting machine. , Compression molding was performed while spraying 2% spindle oil to imbutylidene diurea into the mold of a molding machine to obtain T-N12.
5%.

A molded fertilizer containing 56.4% of C-P2O and 206.2% of C- was obtained.

The product appearance, hardness, drop strength, nitrogen elution rate, and withering rate of the obtained molded fertilizer were as shown in Table 1 below.

For comparison, 29.1 parts of potassium phosphate fertilizer (potassium metaphosphate, manufactured by Taihei Kagaku Sangyo ■) was used instead of potassium silicate fertilizer, and T-N12 was obtained by compression molding in the same manner.
．． 4%, C-P2O523,5%, C-2010.
The appearance and measurement results of 7% molded fertilizer are also listed.

Example 2 Inbutylidene diurea 45. same as in Example 1.
Example 1 Compression molding was carried out in the same manner as in , and T-N was 13%.

A molded fertilizer containing 56.6% of C-P2O and 206.6% of C- was produced.

The physical properties of the obtained molded fertilizer were as shown in Table 2 below.

Example 3 Same isobutylidene diurea as in Example 1 64.
2 parts of potassium silicate fertilizer, 25.8 parts of potassium silicate fertilizer, 3 parts of Minas heavy oil, and 5 parts of a 16% aqueous solution of polyvinyl alcohol were stirred and mixed, and compression molding was performed in the same manner as in Example 1 to obtain T.
- A molded fertilizer containing 18% N and 3% CK2O was obtained.

The physical properties of the obtained molded fertilizer were as shown in Table 3 below.

Claims (1)

[Scope of Claims] 1. A molded fertilizer obtained by compression molding a granular material of a poorly water-soluble nitrogen fertilizer that is a reaction product of an aldehyde having 4 or less carbon atoms and urea, a potassium silicate fertilizer, and mineral heavy oil. . 2. A molded fertilizer obtained by compression molding a granular material of a poorly water-soluble nitrogen fertilizer, which is a reaction product of an aldehyde having 4 or less carbon atoms and urea, a potassium silicate fertilizer, a phosphoric acid fertilizer, and a mineral heavy oil.