JPH013093A - slow release coated 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 Field of Industrial Application The present invention provides a slow-release coated fertilizer, which is useful in the field of fertilizer industry.

BACKGROUND OF THE INVENTION Chemical fertilizers are generally fast-acting, and it is difficult to maintain their effectiveness over a long period of time. Furthermore, if a large amount of fertilizer is applied at once, there is a risk of damage to the salt concentration of agricultural crops and pollution of rivers due to fertilizer leaching. As a means to improve the above points, slow-release fertilizers coated with various resins have been proposed.

When attempting to produce a slow-release coated fertilizer using a spray coating method, the following coating resin systems are generally considered.

(+) Resin solution dissolved in organic solvent (2) Aqueous solution of water-soluble resin (3) 1. Aqueous emulsion of fat Problems to be solved by the invention When producing coated fertilizer using the above resin system, there are various problems. There are problems with this.

In the case of (1), since an organic solvent is used, [4] costs increase. There is also the risk of air pollution and fire during manufacturing. In the case of solvent recovery, equipment is required, which significantly increases equipment costs.

In the case of (2), since the resin is water-soluble, there is a limit to its ability as a protective film to essentially slow down the elution rate of the fertilizing ingredients and slow the effect.

In the case of (3), there are no problems like (1) and (2), but the following problems can be raised with aqueous emulsion-based coating materials.

■ Formation of a continuous film In the aqueous emulsion of resin, fine particles of resin exist in a dispersed state in water. In order to achieve sustained release of fertilizer components, it is necessary to cover the fertilizer with a uniform film. For this purpose, individual emulsion particles must be fused together to form a continuous coating.

■ If the glass transition temperature of the solidified coating film of the coated fertilizer is low, when temperature or load is applied, for example when fertilizers are piled up in bags in the summer, the coated fertilizers will fuse together on the surface of the coating film. , solidify.

Means for Solving the Problems As a result of intensive studies to solve the above two problems, we found that the resin film obtained from the coating material whose main component is an aqueous emulsion of resin has a glass transition temperature of 60°C or higher. For example, it has been revealed that coated fertilizers coated with the resin film exhibit excellent sustained release of fertilizer components and anti-caking properties among fertilizers.
The present invention has now been completed.

Here, the glass transition temperature of the resin film is the glass transition temperature of the coating film obtained when it is actually coated on fertilizer. This includes cases where

The present invention will be explained in detail below.

The present invention provides a slow-release coated fertilizer coated with a resin film having a glass transition temperature of 60° C. or higher, which is obtained by coating with a coating material containing an aqueous resin emulsion as a main component.

The slow-release coated fertilizer of the present invention can be obtained by spraying the coating material onto a solid fertilizer using a commonly used fluidized bed coating device, rotary drum coating device, or the like.

The resin emulsion in the present invention includes an aqueous emulsion of a single or copolymer obtained by polymerizing one or more of the following monomers, and furthermore,
A mixture of more than one aqueous emulsion can be used, and the resulting resin film can have a glass transition temperature of 60° C. or higher.

1) Aromatic vinyl compounds represented by styrene 2) Unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, fumaric acid, itaconic acid, neutralized salts thereof, and esters thereof.

3) Unsaturated carboxylic esters of alcohols further containing functional groups such as grinnor methacrylate, 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate.

4) Vinyl carboxylic acid ester represented by vinyl acetate.

5) Vinyl cyanide compounds represented by acrylonitrile.

6) Vinylamide compounds represented by acrylamide and methacrylamide.

7) Aliphatic diene represented by butadiene.

8) Olefin compounds such as ethylene, propylene, and isobutylene.

9) Halogen-substituted vinyl compounds represented by vinyl chloride and vinylidene chloride.

10) Di- and trivinyl compounds such as divinylbenzene, 1,4-butanediol diacrylate, trimethylol, propane triacrylate.

When producing an aqueous emulsion, polymerization initiators include thermal decomposition initiators such as persulfates, persulfate-ferrous, hydrogen peroxide-ferrous Fenton reagents, persulfate-sodium thiosulfate, etc. , persulfate-acidic sodium sulfite type, hydrogen peroxide-oxycarboxylic acid type, and other redox type initiators can be used. Further, as the emulsifier, ordinary polymer emulsifiers and low-molecular emulsifiers can be used, but they exhibit particularly good performance when used in combination. Polymer emulsifiers include water-soluble alkyd resins, low-molecular emulsifiers include fatty acid salts, higher alcohol sulfuric esters, anionic emulsifiers such as alkylaryl sulfonates, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenol ethers, A 7-ion emulsifier such as polyoxyethylene alkyl ester can be used.

Fertilizer coated with a resin film with a glass transition temperature lower than 60°C tends to solidify. This becomes even clearer when the glass transition temperature is 40°C or lower, and the coated fertilizer becomes solidified even when left at room temperature.

The amount of coating resin is preferably 2 to 15% by weight based on the fertilizer. When the amount is less than this, sufficient coating effect cannot be obtained and sustained release properties are not good. If the amount is too high, the price will be high (
Also, the ratio of the coating material in the coated fertilizer increases, making it impractical.

Note that the elution rate of the fertilizing ingredients can be adjusted by changing the coverage rate. Furthermore, it is possible to adjust the elution rate of the fertilizing component by changing the type of monomer constituting the aqueous resin emulsion or by selecting a combination of a mixture of two or more resin aqueous emulsions.

In the coating film forming process, a film forming aid or a plasticizer may be used in combination, if necessary, in order to improve the film forming properties of the emulsion particles.

As the film-forming aid or plasticizer, commonly used film-forming aids or plasticizers can be used, and specifically, butyl carbitonopebutyl cellosolve, phenyl cellosolve, dibutyl phthalate, dioctyl phthalate, butyl carpitol. Examples include acetate, xy/lene, pendylalconopehexylene criconopequinlucerosolve, 2-ethylhexylcellosolve, octylcellosolve, and the like.

The amount of film-forming aid and plasticizer used varies depending on the glass transition temperature of the aqueous emulsion of the resin used. A resin with poor film-forming properties will not be able to promote the formation of a continuous film and will not improve the sustained release properties.
The resulting coated fertilizer will solidify more easily. Furthermore, it is expensive and not common.

For coating systems with low caking resistance, significant caking prevention can be achieved by dusting coated fertilizers made with Aerosil, talc, etc., and using resin emulsions with low caking resistance. It is effective when used.

Table 1 illustrates the composition of the aqueous resin emulsion specifically used in the Examples and Comparative Examples.

Chapter 1 Table The aqueous emulsion is prepared as follows.

Charge the emulsifier and water into a reactor and stir. The temperature is raised to 80° C. and 10% of the monomer is initially added. Next, 90% of the aqueous solution of polymerization initiator is added. After a while, start dropping the remaining monomer. The dropwise addition was completed in about 3 hours, the remaining polymerization initiator was added, and the mixture was aged for 1 hour. The reaction temperature is kept constant at about 80°C. After the reaction is completed, the mixture is cooled, neutralized with aqueous ammonia, and filtered through cloth.

The glass transition temperature of the resin film was determined by measuring the coating film scraped from the coated fertilizer produced in the example using a DSC measurement device: Seiko Electronics at a temperature increase rate of 10°C/min. It is something.

For the glass transition point, the value at the location indicated by the arrow in the chart in FIG. 3 was adopted.

The method of the present invention can be used for various solid fertilizers such as powder, granules, and granular fertilizers, but is particularly suitable for granular fertilizers. Examples of granular fertilizers include Phosphorous Ankari No. 1 (manufactured by Asahi Kasei Kogyo Co., Ltd.), Shioka Rinyan No. 1, Advanced Chemical Fertilizer No. 777 (manufactured by Nippon Kagaku Co., Ltd.), and KH12-8-10 (manufactured by Kyowa Hakko Kogyo Co., Ltd.). be done.

In the examples, KHII-8-10 was used.

In the examples, a coating apparatus shown in FIG. 1 was used,
A coated fertilizer was produced.

Examples and comparative examples of the present invention are shown below.

Example 1 Film-forming aid; octyl cellosolve 14 parts by weight water
28 parts by weight of the coating material was applied to 500 parts by weight of granular fertilizer at about 80°C.

Example 2 Film-forming aid: Hekinlucerosolve 7 tflfm water 35 parts by weight of the coating material was coated on 500 parts by weight of granular fertilizer at about 75°C.

Example 3 Film-forming aid Nibutylcarpitol 14 parts by weight Water
28 parts by weight of the coating material was applied to 500 parts by weight of granular fertilizer at about 80°C.

Comparative Example 1 500 parts by weight of granular fertilizer was coated with 42 parts by weight of water at about 43°C.

Comparative example 2 water 42
500 parts by weight of the granular fertilizer was coated with the heavy nitrogen coating material at about 35°C.

In Examples 1 to 3, there was no change in the coated fertilizer even under the conditions of 40°C and a load of 250 g/c11, but in the comparative example, severe caking occurred under the conditions.

The sustained release properties are shown in Figure 2. FIG. 2 shows the elution rate of ammonia nitrogen when the coated fertilizer Log obtained in the example was immersed in 20 Qml of water at a water temperature of 30°C.

Effects of the Invention According to the present invention, by coating a solid fertilizer with a coating material whose main component is an aqueous emul/con of various resins, the resin film has a glass transition temperature of 60°C or higher, and is excellent in aqueous emulsion systems. A slow-release coated fertilizer having sustained release properties and caking resistance can be obtained.

In addition, the coating treatment does not require any special method and is very easy to manufacture, and almost no solvents are used, so there is no risk of disaster or pollution. Furthermore, the coated fertilizer has a glossy appearance and is very beautiful and has high commercial value.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a fluidized bed coating apparatus used in Examples and Comparative Examples. FIG. 2 shows the elution rate of coated fertilizers produced in Examples and Comparative Examples. Figures -1 to 3, ratio -1゜2 are examples 1 to 3.
3, Comparative Examples 1 and 2 are shown, respectively. FIG. 3 is a chart showing changes in the glass transition temperature of the coating film. Grant applicant (102) Kyowa Hakko Kogyo Co., Ltd. Figure 1 Figure 2 Number of days at sea (θ)

Claims (1)

[Claims] A slow-release coated fertilizer coated with a resin film having a glass transition temperature of 60°C or higher.