JPH0224241B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a long-acting horticultural drug,
Specifically, when polymerizing ammonium acrylate and/or potassium acrylate dissolved in water in an amount of 2.5 molar or less, various horticultural chemicals are dissolved in the monomer aqueous solution and then polymerized to retain the above additive chemicals. The present invention relates to a method for obtaining a dry solid of a polymer.

Fertilizers, insecticides, fungicides,
Various chemicals such as chemical regulation agents are used. For example, in addition to the three main elements of NPK, which are essential fertilizer components for plants, Fe,
It is widely known that trace elements such as Cu, Mn, B, Zn, Mo and others are necessary. These trace elements may be applied as water-insoluble compounds or in the form of water-soluble salts. Water-soluble salts are easier to use by plants and have a faster effect, but they have the disadvantage of being easily washed away, especially in sandy soils, while water-insoluble salts are less likely to be washed away, but their utilization efficiency is also low.

By the way, if the water-soluble salt is uniformly dispersed in stable aqueous gel particles, sustainability can be maintained without lowering utilization efficiency. Furthermore, the elution rate can be easily adjusted by appropriately selecting the particle size of the aqueous gel.

However, known aqueous gels have drawbacks such as being unstable to microorganisms, requiring complicated processes, and increasing costs. If an aqueous gel containing useful ingredients can be obtained in the form of a dry solid, it is easy to grind it to an appropriate particle size, and it is undoubtedly advantageous in terms of transportation and other handling.

As a result of various studies on such conditions, the present inventor found that
The present invention was achieved by devising a method for easily obtaining a dry water-swellable polymer solid containing useful components.

That is, the present invention provides monomers with a
After uniformly dispersing and mixing the desired useful ingredients in a highly concentrated aqueous solution of acrylic acid neutralized product in the coexistence of 20,000 ppm of divinyl compound, polymerization is performed, and the water is vaporized by the heat generated during polymerization, followed by a drying process. This is a method to obtain a dry polymer solid containing the active ingredient without any oxidation.

Since all of the heat required for evaporation of water is generated by the heat of polymerization of the acrylic acid monomer, the water content in the monomer aqueous solution used for polymerization must be 2.5 times the molar amount or less of the acrylic acid monomer. If water is present in the above manner, the water content of the polymer after polymerization is high, so it cannot be pulverized as it is.

Acrylic acid subjected to polymerization is ammonium and/or potassium salt, and sodium salt may inhibit plant growth.

The divinyl compound coexisting in the monomer solution is used as a crosslinking agent to make the produced acrylic acid polymer insoluble in water, but a water-soluble compound such as methylenebisacrylamide is preferable, and an oil-soluble compound such as divinylbenzene is preferable. It is difficult to uniformly disperse the monomer in an aqueous solution.

To initiate the polymerization, azo compounds such as azobisisobutyronitrile, azobisamidinopropane, and azobisisocyanovaleric acid, which are initiators used in normal radical polymerization, and peroxidants such as sodium hydrogen persulfate and potassium persulfate are used. Sulfates can be used alone or in combination with reducing agents such as sodium bisulfite.

The top of the polymerization container must be open to vent the water vapor generated during polymerization.
It is desirable to polymerize on an endless belt.

Useful substances to coexist in the monomer aqueous solution are not limited to the trace elements listed above, but can be used for all chemicals as long as they can be uniformly dispersed in the monomer aqueous solution and remain in the polymer after polymerization. Needless to say, it is applicable.

Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to the Examples described below unless it exceeds the gist thereof.

Example 1 Collect 72 g of acrylic acid in a 300 ml glass beaker, and add 40 g of 25% ammonia water while cooling to below 50°C.
Mix and neutralize. Next, 14g of potassium carbonate
While defoaming, gradually add 700 mg of methylene bisacrylamide, 10 mg of ammonium molybdate, and 100 mg of nicotine sulfate, and mix uniformly. Adjust temperature to 40°C. Thereafter, 700 mg of azobisamidinopropane hydrochloride was added and mixed, and the mixture was immediately kept on a 70°C water bath. Transfer to a Teflon-coated shallow dish with an area of 100 cm ² and allow to polymerize.

3 minutes after water vapor stops coming out, take it out from the container, cool it, and crush it. Sample 1 is a powder sieved with 40 to 60 meshes using a standard sieve.

Sample 2 was a powder produced in the same manner as Sample 1 except that it did not contain nicotine sulfate.

Efficacy test 2 kg of sandy field soil from the banks of the Sagami River was divided into pots of sufficient size. Randomly divide the pots into 5 pots each for the test plots, and place sample 1 in the test plot and sample 2 in the target plot.
2 g of each was added to each pot and mixed uniformly. 1 liter was applied to each pair.

One liter of tap water was sprinkled on each target area.

One week later, one eggplant seedling was planted in each pot, and the condition thereafter was observed.

In the target plot, all the plants were infested with aphids within two weeks, whereas in the test plot, no insect damage was observed at all until harvest.

Claims (1)

[Claims] 1 2.5 to monomer in the presence of divinyl compound
By uniformly dispersing the useful ingredient in an aqueous solution of ammonium and/or potassium neutralized acrylic acid containing up to twice the molar amount of water, and then polymerizing it and vaporizing the water with the heat of polymerization,
A method for producing a long-lasting horticultural agent, characterized by obtaining a dry polymer solid that can be crushed without undergoing a drying process.