JPS61136982A - Slow release fertilizer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a slow-release fertilizer that can be easily molded and easily handled by changing the speed arbitrarily.

[Prior Art and its Problems 1 Conventionally, liquid fertilizers and powder fertilizers have been mainly used in the cultivation of underwater plants such as seaweed for the purpose of improving yield and quality. In the case of liquid fertilizer, the fertilizer is placed in a container with a large number of micropores on its surface, and by immersing NiK in seawater, the fertilizer flows out into the sea little by little. However, this method does not eliminate the fertilizer itself.
There is a problem in that it is difficult to check the condition and therefore it is very difficult to know the timing to add fertilizer. Moreover, since it is a liquid, it is inconvenient to handle, and the sea is often rough in the winter, making it even dangerous to carry out such work in the harsh winter. On the other hand, powdered fertilizers are easier to handle than liquid fertilizers, but if you put them in a container, the elution port may get clogged, and if you put them in a mesh bag or the like and put them in water, the fertilizer will leach out in a short period of time. A large amount of heat is often required in order for the medicinal ingredients to continue to be effective, and there is a major problem in that the medicinal ingredients decompose due to such high temperatures. or,
Conventional fertilizers mentioned above have a relatively short duration of effect due to moldability problems, and even if you try to adjust the elution rate of medicinal ingredients depending on the amount of target plants, the season, or changes in the sea environment, it may be difficult to adjust the elution rate depending on the size of the molded product. Since there is no other way to do this than adjustment, there were issues that needed to be resolved, such as making it difficult to handle and requiring changes to manufacturing conditions, which could not be done easily.

[Means for Solving the Problems 1] In order to solve the above problems, the present inventors have conducted intensive research and have developed a slow-release fertilizer made by kneading a water-soluble resin, polyethylene glyfur, and medicinal ingredients. discovered that the initial objective could be achieved and completed the present invention.

That is, in the present invention, the blending amounts of two types of compounds, water-soluble resin and polyethylene glycol, are changed as appropriate, and due to the presence of polyethylene glycol, the medicinal ingredients can be easily molded at a relatively low temperature that does not decompose. It has an excellent feature of being very convenient in terms of handling.

Examples of water-soluble resins include polyvinyl alcohol resins, cellulose-based substances, water-soluble starches, polyacrylic 7mide resins, trimenalol melamine resins, and the most preferred are polyvinyl alcohol resins.

This polyvinyl alcohol resin has a saponification degree of 6.
5 to 100 mol%, more preferably 70 to 98 mol%,
Degree of polymerization 100-3,500, more preferably 300-2
, 500 is superior in terms of physical properties such as water solubility and moldability. Further, the resin may be modified polyvinyl alcohol into which a third component is introduced. Such third component is not particularly limited as long as it is copolymerized with vinyl acetate or graph Y is possible, but examples include (anhydrous) maleic acid, hexamaric acid, crotonic acid, itaconic acid, sodium (meth)anoate, and ethylene sulfone. Acid soda, sulfonic acid sorta (meth)7 acrylate, olefin sulfonic acid alkali l such as sulfonic acid soda, (monofurkyl)malate, disulfonic acid sodium furkyl malate, N-menalol acryl 7mide,
Amide group-containing monomers such as alkali salts of acrylamide alkylsulfonic acids, as well as N-vinylpyrrolidone and N-
Examples include vinylpyrrolidone derivatives. Specific examples of water-soluble resins other than polyvinyl alcohol-based resins include:
Carboxymethyl cellulose as a cellulose substance,
Examples of water-soluble starches such as methyl cellulose include a starch, roasted dextrinized starch, and oxidized starch.

The polyethylene glyfur to be kneaded with the above-mentioned water-soluble resin may be any commercially available polyethylene glycol, but preferably has a molecular weight of 400 to 20,000, more preferably 1,000.
．． ~15,000 is preferably used from the viewpoint of moldability and solubility of the molded product.

can be used in powder, granule, lump, solid, or liquid form as long as it can be molded by kneading it with a water-soluble resin or polyethylene glycol.

The blending ratio of water-soluble resin and polyethylene glycol medicinal ingredients can be changed at any time as needed, but the blended amounts of water-soluble resin and polyethylene glycol greatly affect the elution rate of the medicinal ingredient and the dissolution rate of the molded product itself. , Depending on the purpose, water-soluble resin: polyethylene glycol = 5
:95-95:5 (weight ratio), more preferably 35:6
Mix within the range of 5 to 95:5. Assuming that the content of medicinal ingredients is constant, the higher the amount of polyethylene glycol, the faster the dissolution rate tends to be, and the solubility of the water-soluble resin,
For example, the higher the degree of saponification of polyvinyl alcohol, the faster the rate tends to be. However, outside this range, the moldability and dissolution rate become impractical. 0.
When kneading and molding 0.001 to 90 parts by weight, more preferably 0.05 to 90 parts by weight of the medicinal ingredient, any known means may be employed. For example, the most commonly used method is roll kneading, which is thoroughly kneaded using sleeve screws, twin screws, etc., and then molded into rods, tubes, spheres, films, sheets, and strips by press molding, injection molding, squeeze roll molding, extrusion molding, etc. It is molded into any shape such as F land shape or am shape. In this case, a molding temperature of about 15 to 90°C is sufficient. In addition, when the blending ratio of the three components, especially the water-soluble resin component, increases, the viscosity of the kneaded product may become high and it may become difficult to knead. Processing part Water, alcohol, etc. may be added and kneaded before molding.

[Effect 1] As mentioned above, the fertilizer of the present invention can be used as a means of dissolving in water at a desired dissolution rate by appropriately controlling the blending ratio, sometimes the blending ratio of water-soluble resin and polyethylene glycol. When applying a highly concentrated fertilizer for hydroponic cultivation, the molded fertilizer may be dumped directly into the water or the sea, but it is usually sufficient to place it in a net bag or the like and place it in the water or the sea as appropriate. The dosage of fertilizer is not limited to a certain period of time, but in terms of medicinal ingredients, it is approximately 0.00% per day.
It is arranged so that it becomes 1-100g/m'. Of course, it is possible to bury it not only in water but also in any place where there is moisture, such as by burying it in good soil or leaving it in a swamp.

The slow-release fertilizer of the present invention includes the above-mentioned water-soluble resin, polyethylene glyfur, and other ingredients such as Il-free fillers within a range that does not impair the moldability of the medicinal ingredients and the dissolution into water.
Antifoaming agents and the like can be optionally added.

[Example 1] Hereinafter, the slow-release fertilizer of the present invention will be explained in more detail with reference to Examples. However, in the examples, "parts" or "%" should be changed as appropriate. Add 3 parts of water to this, mix, thoroughly knead using a twin-screw extruder, and then heat at 50'C. A spherical test piece with a diameter of 5 cm was created by press molding, and the moldability at that time and the dissolution rate when the test piece was immersed in 10ffi of 18°C salt water (3% 'a) as fertilizer were evaluated. Examined.

The moldability and dissolution rate were evaluated using the following means.

・Moldability ○: Hardness and shape stability that cause no problems in handling Δ: Moldability is possible, but it is brittle or easily deformed.
Inconvenient in handling ×: Unable to be molded/dissolution rate The time until the test piece completely disappeared was measured.

It is written in the table.

(hereinafter referred to as respectful) (Note) SV: Saponification degree P: Degree of polymerization

Claims (1)

[Claims] 1. A slow-release fertilizer made by kneading and molding a water-soluble resin, polyethylene glycol, and medicinal ingredients. 2. The slow-release fertilizer according to claim 1, wherein the water-soluble resin is a polyvinyl alcohol resin. 3. The molecular weight of polyethylene glycol is 400-20,
000. The slow release fertilizer according to claim 1, which is 000. 4. Claim 1 for use as fertilizer for underwater plants
Slow-release fertilizer as described in section.