JPH0655647B2 - Sterilizing and fungicide solution - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a bactericidal / moldicidal solution. For more details,
It relates to a solution containing 2-benzimidazole carbamate.

(B) Conventional Technology It is known that 2-benzimidazole carbamate, especially methyl 2-benzimidazole carbamate, can be used as a bactericidal / fungicidal agent for agricultural / horticultural / industrial purposes.

Generally, when using a bactericidal / moldicidal agent for agricultural and horticultural applications, the following methods are applied to plants and the like.

(a) Spray the plants as a solution.

(b) Inject the solution into the tree under pressure.

(c) Immerse plant roots, seeds, etc. in the solution.

(d) The drug is mixed in the soil for planting. Also,
When the sterilizing / moldicidal agent is used for industrial purposes, it is sprayed on the object as (e) solution, for example.

(f) Immerse the object in the solution.

(g) Press into the target with the solution.

(h) Apply the solution to the object.

(i) When the target is liquid, the drug is added to and mixed with the target.

Etc. can be used.

Therefore, when using a bactericidal / moldicidal agent, it is preferable that it can be used in the form of a solution or an aqueous solution, and it is particularly advantageous that the concentration of the active ingredient in the solution is high. For example
In the method (b), the high-concentration solution requires a smaller amount of injection liquid, and thus the treatment operation becomes easier. Also, when used as a low-concentration solution, it is advantageous to dilute the high-concentration solution with water immediately before use because the storage space and transportation cost of the drug can be reduced.

However, methyl 2-benzimidazolecarbamate is a solid at room temperature, its solubility in water and general organic solvents is extremely low, and the method of forming a solution is limited.

Japanese Examined Patent Publication (Kokoku) No. 45-11319 discloses that a solution having a concentration of methyl 2-benzimidazolecarbamate of 2000 ppm or less can be prepared by using an acid whose pH can be 3.0 or less, and glacial acetic acid and 70 % Glycolic acid aqueous solution contains about 10% methyl 2-benzimidazolecarbamate.
It is disclosed to dissolve by weight.

JP-A-49-93537 discloses that an ethylene glycol solution or an aqueous solution in which the concentration of methyl 2-benzimidazolecarbamate is 10% is obtained by coexisting equimolar or more of propanesultone with methyl 2-benzimidazolecarbamate. Is disclosed.

Further, in JP-A-58-67608, a solution of methyl 2-benzimidazolecarbamate having a concentration of 0.01 to 5% by weight is prepared by adding a salt of methyl 2-benzimidazolecarbamate to water together with a weak acid. What can be done, and weak acids used here include, for example, fluoroboric acid, hexafluorosilicic acid, monoesters or diesters of phosphoric acid and alcohols, sulfamic acid, aliphatic or aromatic sulfonic acids (for example, 4-phenolsulfonic acid). It is disclosed.

(C) Problems to be Solved by the Invention According to the conventional technique as described above, when an inorganic strong acid whose pH can be adjusted to 3.0 or less is used, a solution having a concentration of methyl 2-benzimidazolecarbamate of 2000 ppm or less is used. When a weak inorganic acid is used, a solution having a methyl 2-benzimidazolecarbamate concentration of 5% by weight or less is obtained. A solution with a methylate concentration of less than about 10% by weight is obtained.

However, it would be even more advantageous if a solution with a higher concentration of methyl 2-benzimidazole carbamate was obtained. Therefore, it has been desired to find a solvent capable of forming methyl 2-benzimidazolecarbamate into a solution having a higher concentration.

As a result of earnest studies on the solvent for methyl 2-benzimidazolecarbamate, the present inventors have found that a mixed solution containing hypophosphorous acid and a specific organic carboxylic acid dissolves methyl 2-benzimidazolecarbamate at a remarkably high concentration. They have found that they are solvents capable of being used, that is, hypophosphorous acid and an organic carboxylic acid function as remarkably excellent solubilizing agents when they are used in combination, and arrived at the present invention.

(D) Means for Solving the Problems Thus, according to the present invention, 2-benzimidazole carbamic acid ester is mixed with hypophosphorous acid and a lower fatty acid selected from formic acid, acetic acid and propionic acid in an aqueous solvent. A sterilizing and fungicide solution characterized by being dissolved is provided.

The 2-benzimidazole carbamic acid ester which is the object of the present invention refers to 2-benzimidazole carbamic acid lower alkyl ester, and particularly the following formula: Methyl 2-benzimidazole carbamate represented by is preferable. This compound is commercially available with a purity of about 99% and is an off-white powder having a melting point of about 300 ° C. Commercially available products are "MERGAL BCM" and "Preventol Tr
It is known to have a product name such as ial Product OC3015 ”.

The 2-benzimidazolecarbamic acid ester used in the present invention does not necessarily have to be a pure product, and may be a commercially available product as described above or one containing impurities derived from the manufacturing process.

In the present invention, an aqueous medium solution of hypophosphorous acid and a water-soluble organic carboxylic acid is used to dissolve the 2-benzimidazolecarbamic acid ester. Here, the aqueous medium refers to water or a solvent composed mainly of water, and in this, for example,
Alcohols such as methanol and ethanol, ethylene glycol, polyethylene glycol with a molecular weight of up to 400,
Glycols such as propylene glycol, glycerin,
Organic solvents such as dimethylformamide and dimethylsulfoxide may be contained, and these organic solvents may be preferable in terms of improving permeability and wettability and lowering the freezing point.

Hypophosphorous acid is represented by the chemical formula H ₃ PO ₂ , is one of the strong inorganic acids, and the pure one has a melting point of about 26.5 ° C.
It is deliquescent and is usually used in the form of an aqueous solution of 30 to 50% by weight. Therefore, the hypophosphorous acid used in the present invention may be an aqueous solution having such a concentration, and may have a lower concentration or a higher concentration. Of course, you can use a pure product.

On the other hand, the lower fatty acid used in the present invention is preferably water-soluble (particularly having an ionization constant of 10 ⁻³ to 10 ⁻⁵ ) and liquid at room temperature, but lower fatty acids such as formic acid, acetic acid and propionic acid are particularly preferable. .

When the concentration of 2-benzimidazolecarbamic acid ester is X% by weight, the concentration of hypophosphorous acid is Y% by weight, and the concentration of lower fatty acid is Z% by weight, the compounding ratio of each component must satisfy the following formula. .

Y ≧ 0.4 (X−10)> 0 Z ≧ 0.5X X + Y + Z ≦ 100 When the above formula is not satisfied, the 2-benzimidazolecarbamic acid ester is not completely dissolved, and the solution becomes cloudy and 2-benzimidazole is present. It is not preferred because it causes precipitation or crystallization of carbamic acid ester or its salt.

The weight of hypophosphorous acid and lower fatty acid referred to here is
It means the total of free hypophosphorous acid and lower fatty acid, and hypophosphorous acid and lower fatty acid in a salt-forming state, which are contained in the respective solutions.

The mixing ratio of hypophosphorous acid is less than 1.6 parts by weight per 1 part by weight of methyl 2-benzimidazolecarbamate (1.6X>
Y) is sufficient, and it is not necessary to further mix it.

In the solution of the present invention, the content (ie concentration) of methyl 2-benzimidazole carbamate can be 42% by weight or higher. In the present invention, a solution having a methyl 2-benzimidazole carbamate content of more than 10% by weight (for example, a solution having a content of 11% by weight or more), which could not be obtained at all, can be obtained.

This effect is based on the effect that the 2-benzimidazolecarbamic acid ester contained in the solution forms a salt with hypophosphorous acid and / or an organic carboxylic acid to be stably solubilized to a high concentration. it is conceivable that.

To prepare the solution of the present invention, for example, 2-benzimidazolecarbamic acid ester may be added and mixed to a mixed solution of a high-concentration hypophosphorous acid aqueous solution and a lower fatty acid.
When the 2-benzimidazole carbamic acid ester is mixed and dissolved, it can be rapidly dissolved by heating.

The solution of the 2-benzimidazolecarbamic acid ester thus obtained is useful from the viewpoint of storage and transportation, which can be used as a bactericidal and / or fungicide directly or as diluted as described above.

It should be noted that the solution of the present invention may contain a corrosion inhibitor, a dye, and additionally an effective substance having a bactericidal action to the extent that the effects of the present invention are not impaired.

(E) Example (Example) Methyl 2-benzimidazole carbamate, hypophosphorous acid, lower fatty acid and water were heated as necessary so that the compounding ratio (weight ratio) shown in Tables 1 to 3 was achieved. While mixing and stirring, a methyl 2-benzimidazole carbamate solution was obtained.

Each of the composition liquids in Tables 1 to 3 completely dissolved methyl 2-benzimidazolecarbamate.

(Comparative Example) Mixing methyl 2-benzimidazolecarbamate with an aqueous phosphoric acid solution so that the compounding ratio of methyl 2-benzimidazolecarbamate is 3.0% by weight, phosphoric acid 48.5% by weight and water 48.5% by weight. It was stirred. As a result 2
-Methyl benzimidazole carbamate was not completely dissolved, the solution became cloudy, and a large amount of precipitate of methyl 2-benzimidazole carbamate remained.

(F) Effect of the Invention According to the solution of the present invention, the concentration of 2-benzimidazolecarbamic acid ester is higher than that of the conventional one (for example, 42% by weight).
The above) can be stably contained in a solution state, and this solution can be diluted with water and used at any concentration.

Therefore, when using 2-benzimidazole carbamic acid ester as a bactericidal and fungicide,
It is extremely useful in terms of storage and transportation.

Claims (3)

[Claims] 1. A sterilization method comprising dissolving 2-benzimidazole carbamic acid ester in an aqueous medium using hypophosphorous acid and a lower fatty acid selected from formic acid, acetic acid and propionic acid. • A fungicide solution. 2. A 2-benzimidazole carbamic acid ester, a hypophosphorous acid and a lower fatty acid are represented by the following formula: 1.6 X> Y ≧ 0.4 (X-10)> 0 Z ≧ 0.5X X + Y + X ≦ 100 [where X is 2 -The concentration of benzimidazole carbamate, Y is the concentration of hypophosphorous acid, and Z is the concentration of lower fatty acids. (The unit is wt%)]. 3. The solution according to claim 1 or 2, wherein the 2-benzimidazole carbamate ester is methyl 2-benzimidazole carbamate.