JPH07238002A - Nonvolatile earthworm control agent composed of high-concentration hinokitiol - Google Patents

Abstract

PURPOSE:To obtain an earthworm control liquid useful for growth and protection of lawns in a golf course by admixing volatile hinokitiol with a polyvalent alcohol such as glycerin to prepare an nonvolatile solution. CONSTITUTION:This earthworm control liquid is composed of an nonvolatile solution containing high-concentration hinokitiol and prepared by mixing volatile hinokitiol in a polyvalent alcohol selected from glycerin, propylene glycol, 1,3- butanediol and their analogous compounds. The concentration of hinokitiol in this liquid is preferably 5 to 6wt.% and a weak base component is preferably further admixed therewith in an amount of <=1 equivalent based on hinokitiol. As the weak base, arginine, tris (hydroxymethyl) aminomethane, 2-amino-2- methyl-1,3-propanediol, 2-amino-2-methylpropanol or an analogous compound thereof is preferably used. Hinokitiol in this liquid preparation is useful as a lawn growth protecting agent substitutable for the conventional agrochemicals and excellent in residual effect.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to lawn protection for lawns of golf courses which have spread to cover all of Japan. In recent years, the development of golf courses has become popular for the world-famous sport; golf. For this reason, the destruction of the natural environment has been attracting attention each year, and opposition to its development is also faltering. One of the most serious damages to nature on the golf course is the use of pesticides for lawn protection. Contamination of drinking water from the drinking water of the residents around the golf course has become a major social problem. This problem is increasing social contact year by year. Hinokitiol was a research target of the present inventors because of its high effect as a lawn growth protective agent instead of pesticide, but its low residual life. Since hinokitiol is volatile, it is difficult to maintain its effect when applied outdoors. Therefore, it is necessary to develop a non-volatile solution.

[0002]

2. Description of the Related Art Organophosphorus agents, carbamate agents and the like are used as lawn insecticides and fungicides. When spraying these pesticides, workers have inhaled and suffered from acute poisoning such as general malaise, headache, dizziness, nausea, consciousness clouding and respiratory paralysis. In addition, since it is less susceptible to decomposition in the environment, it easily remains, and as a result of being transferred from soil to groundwater, pollution of drinking water has become a problem. Currently, the use of pesticides on golf courses is being regulated by the national and local governments, and substances with low toxicity and high biodegradability are desired. Hinokitiol is a natural product that has strong antibacterial activity and insecticidal activity, has low toxicity to humans and plants, and is biodegradable and does not remain in the environment for a long time. Currently, hinokitiol is industrially synthesized, and its range of application is expanding in combination with its cost reduction and effect. However, since hinokitiol is poorly soluble in water, its use is limited. Therefore, in the prior art, Japanese Patent Application Laid-Open No. 51-2946 discloses that hinokitiol sodium salt is dissolved in ethanol and then neutralized with acetic acid to solubilize it in water.
JP-A-60-139640 discloses a method for preparing an aqueous solution containing a few% of hinokitiol using water of crystallization with anhydrous inorganic acid or organic acid sodium salt. However, the conventional use of the hinokitiol aqueous solution is merely described as pharmaceuticals, pesticides and the like.

[0003]

[Summary of the Invention] Hinokitiol, which is an active ingredient of the present invention, is an essential oil component of Hinoki cypress plants such as Taiwan Hinoki, Hiba, and Japanese cedar, and has various physiological activities, and is widely used in cosmetics, preservatives, insecticides and the like. It is applied. The present inventors have the effect of controlling the earthworms and insect larvae living in the ground in hinokitiol, and when applied to lawns and the like, to moles that invade to seek them as food,
We paid attention to the fact that it is possible to prevent harm such as digging up the soil and cutting the roots. However, since hinokitiol is volatile, it is difficult to maintain its effect when it is sprayed outdoors like pesticides. Therefore, we have developed a formulation of hinokitiol that can be used as a persistent agricultural chemical by using a solvent that dissolves hinokitiol well and that is difficult to volatilize. Even if this formulation is sprayed, the solvent and the main agent do not volatilize rapidly, and the hinokitiol continues to remain in the state of a solution. Since it adheres to the body surface of earthworms and pests in a state of being dispersed in a molecular form, it is more easily absorbed than the contact of solids in the state of being deposited, and the effect manifests quickly and reliably. The solvent used here is also required to be less irritating to the human body and plants, in addition to being less volatile. As a result of intensive studies, it was found that this requirement can be satisfied by using polyhydric alcohols as a solvent. Monohydric aliphatic alcohols (methanol, ethanol, propanol, etc.) are commonly used as solvents, but they have an inhibitory effect on central nervous system functions, and
It has the drawback of being irritating to mucous membranes. However, when the number of hydroxyl groups in the aliphatic alcohol increases, the central depressant effect disappears and the stimulative effect is alleviated. Further, the polyhydric alcohol has a stronger intermolecular force and has a higher boiling point than a monohydric alcohol having the same carbon number. The polyhydric alcohol used in the present invention is used in foods and cosmetics, glycerin,
Examples include propylene glycol and 1,3-butanediol. It is well known that all of them have high safety and low irritation due to their use. Hinokitiol dissolves in these polyhydric alcohols to any concentration. Also, these polyhydric alcohols are freely miscible with water.
Although the preparation is diluted to an appropriate concentration for actual spraying, it can be diluted with "water" which is the cheapest solvent, so that the preparation of the present invention is very practical. That is, by spraying a solution of a formulation in which hinokitiol is diluted with water to a concentration of about 0.3%, earthworms and larvae of the soil are exterminated, and vegetation such as lawns is protected from moles that are predators. Furthermore, in order to form a stable solution even in a state in which a formulation containing hinokitiol, which is poorly soluble in water, at a high concentration is diluted with water, the present invention uses an organic solvent that dissolves hinokitiol well and is freely miscible with water. In addition to, it is characterized by containing a base. Hinokitiol is a weak acid, and by adding 1 equivalent or less of a base thereto, a salt stable in water is formed. The type of base does not matter, but in consideration of the characteristics that it is well soluble in the polyhydric alcohol used and water, and has little irritation to humans and plants, arginine and tris (hydroxymethyl) aminomethane are used. , 2-amino-2-methyl-1,3-propanediol, 2-amino-2-methylpropanol and the like were used. Since these are weak bases and do not contain an excessive amount, the liquidity of the preparation is near neutral and irritation is small. On the other hand, hinokitiol has a strong chelating action, and easily forms a colored metal chelate. EDTA is also included as a sequestering agent to prevent the inclusion of metals from the diluting water and spraying equipment.

[0004]

【Example】

Example 1 A state in which a solution was prepared by changing the concentration of hinokitiol stepwise and a solution state when the solution was diluted with water to a hinokitiol concentration of 0.3% are shown. 1,3-Butanediol was used as the solvent. Hinokitiol (W / V%) 1 2 5 10 20 40 ──────────────────────────────────── Preparation Immediately soluble state − − − − − − Dissolved state ++ ++ ++ ++ ++ ++ +++ (Solubility: − Clear ++ Emulsified state +++ Two-phase separation) For 1,3-butanediol Hinokitiol was dissolved at any concentration. When diluted with water, it becomes a finely emulsified state. If it is used immediately after dilution, it can be used as an earthworm repellent.

Example 2 A state of a solution prepared by changing the concentration of hinokitiol stepwise and further adding 1 equivalent of Tris to the amount of hinokitiol, and diluting the solution with water to a hinokitiol concentration of 0.3%. The melting state of the sample is shown. 1,3-Butanediol was used as the solvent. Hinokitiol (W / V%) 1 2 5 10 20 Tris (W / V%) 0.9 1.8 4.5 9 18 ─────────────────────────── ────────── Solubility immediately after preparation − − − − − Solubility upon dilution − − − − ++ (Solubility: − Clear ++ Emulsified state +++ Two-phase separation) 1,3-Butane Hinokitiol and Tosuri were dissolved in the diol at any concentration. When the concentration was 10% or less, a clear solution was obtained even when diluted with water.

[0006]

[0007] Both the formulations of Example 1 and Example 2 can be diluted with water at any ratio. The obtained diluted solution is clear and does not become cloudy even when stored at 5 ° C. for 6 months.

Example 5 Twenty earthworms each (body length; average 72 mm, fresh weight; average 0.
23g) A container with soil (volume of soil: 50l, surface: 20 x 60)
cm). Prepare three containers. Place the container in a well-ventilated area and spray 50 ml of each test solution onto the surface of the soil with a sprayer. Observe at regular intervals and count the number of individuals dying by crawling to the surface. On the last day of the test, soil is removed from the container and the number of dead earthworms inside is also counted. Test solution The solution of Example 1 is diluted 20 times with water. Test solution 0.3% hinokitiol ethanol solution. Test solution Hinokitiol 0.3%, sodium hydroxide
Aqueous solution containing 1%. The results are shown in Table 1. Although the concentration of hinokitiol in the test solution was the same, the number of dead earthworms was conspicuous only in the test solution of Example 1.

[0009]

[Table 1] Number of dead earthworms (cumulative) Test period (days) 0 1 3 5 10 15 30 ──────────────────────── ────────────── Test solution 0 4 5 5 7 9 18 Test solution 0 2 2 2 3 3 7 Test solution 0 2 3 3 4 4 7

Example 6 Twenty paper discs (thickness: 1.5 mm, diameter: 8 mm) are prepared for each test solution of Example 3. Drop 0.10 ml of each test solution on a paper disk and place it in a well-ventilated outdoor area. Take a paper disk in a flask at regular intervals, add 10 ml of 2% ferric chloride solution and 10 ml of dichloromethane, and stir well. The organic layer is separated, the aqueous layer is thoroughly washed with dichloromethane, and the organic layer and the washing solution collected in advance are combined to make exactly 25 ml, and this is used as the sample solution. Measure the absorbance of the sample solution at a wavelength of 425 nm. Separately, the standard solution of hinokitiol is similarly operated, and the amount of hinokitiol in the paper disk is quantified by the absolute calibration curve method. Table 2 shows the quantitative values and the results of measuring the changes over time. Although the concentration of hinokitiol in the test solution was the same, only the test solution of Example 1 showed a small decrease in hinokitiol due to volatilization.

[0011]

[Table 2] Amount of hinokitiol in paper disc (μg) Test period (days) 0 1 3 5 10 ─────────────────────────── ────── Test solution 321 310 287 304 273 Test solution 328 281 257 186 121 Test solution 294 265 242 171 107

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Claims (5)

[Claims] 1. An earthworm controlling liquid agent comprising a non-volatile solution containing a high concentration of hinokitiol in a polyhydric alcohol. 2. The liquid preparation according to claim 1, wherein the polyhydric alcohol is selected from glycerin, propylene glycol, 1,3-butanediol and the like. 3. The liquid agent according to claim 1, which is a transparent non-volatile solution in which the concentration of hinokitiol in the polyhydric alcohol is 5 to 6%. 4. The liquid preparation according to claim 1, wherein the nonvolatile solution according to claim 1 is mixed with a weak base component in an amount of 1 equivalent or less with respect to hinokitiol, and has few side effects on plants, mammals, and humans. 5. The weak base is selected from arginine, tris (hydroxymethyl) aminomethane, 2-amino-2-methyl-1,3-propanediol, 2-amino-2-methylpropanol and the like. The liquid preparation described in.