JPS5924117B2 - 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 slow-release and has excellent fall strength.

As a slow-release molded fertilizer, there is a molded fertilizer made by compression molding imbutylidene diurea, which is one of the reactants with aldehyde urea, and mineral heavy oil (Japanese Patent Publication No. 54-24942).
) is known and widely used.

This molded fertilizer has excellent durability, product hardness, shape retention in water,
All of them have excellent properties such as drop strength, but some crushing is unavoidable during long-distance transportation and handling such as loading and unloading, so something with even better drop strength was desired.

As a result of extensive research in order to obtain a molded fertilizer with excellent properties, especially drop strength, the present inventors discovered that a powdered form of nitrogen fertilizer, which is a reaction product of aldehyde diurea and is poorly soluble in water, and a specific The present invention was completed based on the knowledge that when compression molding an olefin-based low polymer, it is possible to obtain a slow-release molded fertilizer that is easy to mold and has excellent properties such as drop strength.

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 Nitrogen fertilizer powder and granules that are poorly soluble in water at 40°C
This is a molded fertilizer made by compression molding an olefin-based low polymer that is solid at room temperature and exhibits fluidity at the above temperatures.

The present invention will be explained in detail below.

Examples of the poorly water-soluble nitrogen fertilizer used in the present invention, which is a reaction product of an aldehyde with a carbon number of 4 or less and urea, include isobutyraldehyde, normal butyraldehyde, propionaldehyde, crotonaldehyde, acetaldehyde, formaldehyde, etc. It is obtained by reacting an aldehyde of 4 or less, or a mixture thereof, with urea, and specifically, imbutylidene diurea, normal butylidene diurea, propylidene diurea, crotonylidene diurea, ethylidene diurea, Examples include reaction products of formaldehyde and urea, which have the same solubility in water as isobutylidene diurea, etc. Typical examples include isobutylidene diurea, which is commercially available as a slow-release fertilizer, and chlorodehyde. Examples include granular materials such as nylidene diurea.

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

Examples of olefin-based low polymers that are solid at room temperature and exhibit fluidity at temperatures of 40°C or higher include ethylene, propylene, butene, imbutylene, monoolefins with 6 or more carbon atoms, or low polymers of olefin mixtures mainly composed of these. Specific examples include polyethylene wax produced as a by-product during the production of polyethylene resin, low-polymerization polypropylene, low-polymerization polybutene, and low-polymerization polyisobutylene produced as a by-product during the production of polypropylene resin.

These olefin-based low polymers are used in a fluidized state at a temperature of 40°C or higher, but if olefin-based low polymers are used at too high a temperature, there is a risk of decomposition of the nitrogen fertilizer powder, and This is not a good idea as it increases the cost of the heat source for heating the olefinic low polymer.

Usually, it is preferable to use an olefinic low polymer heated to 40 to 150°C, preferably 40 to 100°C.

Two or more kinds of olefin-based low polymers can be used in combination.

These olefin-based low polymers are usually used by being sprayed and mixed into nitrogen fertilizer powder before compression molding, or by being sprayed into the mold section of a molding machine during compression molding.

The amount added is 1-io, preferably 2 to 5% by weight, based on the nitrogen fertilizer powder.

If the amount is too small, the molding yield will decrease and the drop strength of the resulting molded fertilizer will also decrease.

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

In addition, if inorganic salts of lignin sulfonic acid, such as calcium salts, asphalt, or resins such as polyvinyl alcohol, rubber latex, vinyl acetate resin, petroleum resin, and coumaron resin are used together with the above olefin-based low polymer, This is preferable because it can improve the molding yield and provide a product with good hardness and appearance.

Considering the sustainability of fertilizer effect and formability, the volume of the shaped fertilizer is usually 5 to 1OOcIIt1, preferably 1O to 30
It is better to set it as crI@degree.

The hardness of the molded fertilizer varies depending on its shape and volume, but if it is too small, the shape retention will be poor and sufficient slow-release properties will not be obtained. It is best to choose conditions that will result in the following conditions:

The shaped fertilizer of the present invention may be made of nitrogenous fertilizers such as urea, ammonium nitrate, ammonium chloride, ammonium phosphorus, ammonium sulfate, superphosphate lime, heavy superphosphate lime, calcined phosphorous fertilizer, melted phosphorous fertilizer, heavy calcined phosphorous fertilizer, etc. It is also possible to contain phosphorus, phosphoric acid fertilizers such as magnesium superphosphate, potassium chloride, potassium sulfate, potassium silicate, and potassium fertilizers such as subpotassium fertilizers, as well as calcium, magnesium, zinc, boron, manganese, etc. hydroxides of alkali metals or alkaline earth metals for the purpose of improving formability,
Carbonates, oxides, etc. can also be added.

The shaped fertilizer of the present invention is easy to manufacture, has a good appearance, and has excellent product hardness and drop strength.
When fertilized, there is no initial salt concentration problem and the fertilizing effect can be maintained for a long period of time, so it is suitable for forestry, fruit trees, etc.
It is of great value for use in garden crops, general greening, lawns, seaweed, seaweed, 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 "% by weight", respectively.

In addition, hardness indicates the value measured by compressive fracture pressure using a Honya-style fracture hardness tester, and drop strength indicates the value obtained when 15 kg of the product is packed in a bag and allowed to drop twice from a height of 1.5 m onto a concrete floor. It is expressed as the weight ratio of the resulting crushed material to the product.

Example 1 and Comparative Examples 1 to 2 Isobutylidene diurea powder with a particle size of approximately 0.7 to 2 mm (manufactured by Mitsubishi Chemical Corporation, trade name I), conditioned to a moisture content of 6%
BDU), 4 parts 90 to isobutylidene diurea
Polyethylene wax (manufactured by Mitsubishi Chemical Industries, Ltd., average molecular weight 2000) heated to ℃ was added, and a wax mold (34
A molded fertilizer was produced by compression molding using a 34×20 mm briquette machine with a volume of 15.47 mm and spraying 2% liquid paraffin with respect to imbutylidene diurea into the mold.

The product appearance, hardness, and falling strength of the obtained molded fertilizer were as shown in Table 1 below.

For comparison, Example 2 and Comparative Example 3 in which the same amount of heavy oil (JIS Standard Type 3 No. 2, commonly known as C heavy oil No. 2) or asphalt was used instead of polyethylene wax. Along with polyethylene wax, a 16% aqueous solution of polyvinyl alcohol (manufactured by Nippon Gosei ■, trade name Gohsenol NH-18) was added at 5% to imbutylidene diurea, and compression molding was performed in the same manner as above to produce a molded fertilizer. did.

The product appearance, hardness and falling strength of the obtained molded fertilizer were as shown in Table 2 below.

For comparison, the results obtained when the same amount of heavy oil was used instead of polyethylene wax are also shown.

Claims (1)

[Scope of Claims] 1. A granular material of nitrogen fertilizer that is poorly soluble in water, which is a reaction product of an aldehyde having 4 or less carbon atoms and urea, and an olefin-based low polymer that exhibits fluidity at a temperature of 40°C or higher. Molded fertilizer made by compression molding. 2. The molded fertilizer according to claim 1, which is formed by compression molding the olefin-based low polymer in an amount of 1 to 10% by weight based on the nitrogen fertilizer powder.