JPS63270604A - Liquid insect repellent - Google Patents

Abstract

PURPOSE:To obtain a fast effective liquid insect repellent which is composed of an aqueous solution containing trioxane as an active ingredient, thus being safety outdoor or indoor, because it is not inflammable and free from environmental pollution on acount of low toxicity and reduced residual effect. CONSTITUTION:The subject liquid insect repellent is an aqueous solution containing solid or melted trioxane which has insect-repelling action as such, preferably in a concentration of 8-11wt.%. In order to prepare a liquid insect repellent of increased storage stability, the trioxane desirably has purity as high as possible and stabilizers may be added. This repellent has fast-effecting properties and keeps the activity for a certain time, but does not kill insects and manifests its action against ants, bees, cockroaches, and other insects.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an insect repellent that is in the form of an aqueous solution at room temperature.

[Prior art 2] Problems to be solved by the invention: When a person stays at a fixed point outdoors for a fixed period of time.

For example, when eating lunch at picnics, hiking, garden parties, sports days, etc., ants, ground beetles, and mealbugs.

Everyone has often experienced the discomfort caused by insects such as stink bugs crawling around. In addition, people often suffer actual damage when they are bitten by ants or insects swarm around food outdoors or indoors. However, there have been few insect repellents suitable for such cases.

Since it quickly evaporates, its action hardly lasts. Furthermore, what is desired is insect repellent action, not insecticidal action. In other words, in such cases, it is sufficient to drive the insects away; however, killing the insects does not necessarily leave a strong residue and can cause environmental pollution. Furthermore, repellents used on human skin have an insufficient range of effectiveness. Furthermore, these conventional drugs are generally oil-soluble and are flammable to varying degrees, making them dangerous if used near open flames such as bonfires or stoves.

[Means for solving the problems and their effects] The present inventor has conducted repeated research to develop an insect repellent that can be used safely outdoors or indoors on the ground, unlike conventional insecticides and repellents. The present invention was completed by discovering that an aqueous solution of 1,3,5-trioxane (hereinafter simply referred to as trioxane) is suitable for this purpose.

That is, the present invention is based on the inventor's discovery that trioxane has its own insect repellent action, and unlike conventional insect repellents such as p-dichlorobenzene, naphthalene, and camphor, trioxane is water-soluble. It takes advantage of this unique property. The present invention is a liquid insect repellent whose active ingredient is an aqueous solution containing trioxane.

In the present invention, a higher concentration of trioxane is preferable in order to enhance the insect repellent effect, but in order to prevent crystal precipitation during use, the upper limit of trioxane concentration is preferably 15% by weight, particularly preferably 11% by weight. .

On the other hand, if the concentration of trioxane is too low, the efficacy will be weak and the amount used will be large.

The lower limit is preferably 5% by weight, particularly preferably 8% by weight.

There are no particular limitations on the method for preparing the trioxane aqueous solution. For example, trioxane melt or solid may be mixed with water at a predetermined ratio and dissolved.

The water used as a raw material does not need to be highly purified. Water quality comparable to that of tap water normally used for drinking water is sufficient. More purified water, such as distilled water or deionized water, can also be used.

The aqueous solution prepared in this manner can normally be stored for several months to several years, but in order to further improve the storage stability, it is preferable to use trioxane as a raw material of as high a purity as possible. The amount of formic acid, which is an impurity in the raw material trioxane, is preferably 20 ppm or less, particularly preferably 10 ppm or less, based on the trioxane. Further, the amount of formaldehyde is preferably 50 ppm or less relative to trioxane.

Particularly preferred is 20 ppm or less.

In order to further enhance storage stability, one or more stabilizers can be added. Generally used as trioxane stabilizers are substances that function as antioxidants or polymerization inhibitors, such as sterically hindered phenols, disulfides, amines, and thiocarbamoyl compounds.

and organic trivalent phosphorus compounds. The amount of these stabilizers added varies depending on the type of stabilizer, trioxane concentration in the solution, and other conditions, but it is usually 1 to 2 trioxane.
It is about 11,000 pp. These stabilizers, especially those that are sparingly soluble in water, can be easily dissolved by uniformly adding them to trioxane in advance.

Trioxane is stable in neutral or alkaline aqueous solutions. However, in strong acidity, hydrolysis occurs. Taking safety in use into consideration, the hydrogen ion concentration of the liquid insect repellent of the present invention is preferably adjusted to pH 6 to 8 in a range of pH 4 to 1O2.

Such a hydrogen ion concentration can usually be achieved without particular pH adjustment by using the above-mentioned raw materials. If necessary, pH adjustment can be carried out by any suitable method. For example, when the pH is in the acidic range, an appropriate amount of stabilizer amines may be added.

The liquid insect repellent of the present invention has a pleasant fragrance from trioxane itself, but an appropriate fragrance can be added if desired.

The liquid insect repellent of the invention can be applied, for example, by manual spraying or by a suitable aerosol method.

The amount to be used varies depending on the environment of use, so it cannot be generalized, but for example, apply 0.02% of the liquid insect repellent of the present invention on the ground in the shade.
If sprayed at a rate of ~0.1 ml/cm2 to a width of about 10 cm, an insect repellent zone can be formed.

The insect repellent effect usually lasts for about 0.5 to 2 hours. If you soak it in absorbent cotton and use it in a cool, dark place with little ventilation.

The action can be sustained for a longer period of time.

[Example] Next, the present invention will be explained in more detail with reference to Examples.

Example 1 Trioxane powder containing 15 ppm of formic acid and 28 ppm of formaldehyde was dissolved in deionized water (tap water deionized with an ion exchange resin) to prepare an aqueous solution with trioxane concentration of 6% by weight and pH of 5.8. . This aqueous solution was used as a liquid insect repellent.

Absorbent cotton impregnated with a 5% by weight sucrose aqueous solution was placed in two separate locations on the ground in a shady area in a residential area. On one side, 40 ml of the above-mentioned liquid insect repellent was uniformly sprayed in a ring shape of about 10 cm with an average radius of 20 cm centered on the absorbent cotton through fine pores. When observed after an hour, a large number of red ants had gathered in rows on the absorbent cotton that had not been sprayed with liquid insect repellent, and a wasp, which appeared to be a type of paper wasp, had also flown in. In contrast, no insects were attached to the absorbent cotton around which the liquid insect repellent had been sprayed.

Comparative Example 1 At the same time as the liquid insect repellent spraying experiment in Example 1, deionized water to which 10 ppm of formic acid and 10 ppm of formaldehyde were added (the concentrations of formic acid and formaldehyde in this solution were equal to 1 part of each of the liquid insect repellents used in Example 1). An experiment was carried out in the same manner as in Example 1, except that the liquid insect repellent of the present invention was used in place of the liquid insect repellent of the present invention.

When observed after 1 hour, two rows of red ants and two bees were found attached to the absorbent cotton, indicating that the solution used had no insect repellent effect at all.

Example 2 2 ppm formic acid and 3 ppm formaldehyde and pentaerythritol-tetrakis[3-
(3,5-di-t-butyl-4-hydroxyphenyl)
A trioxane powder containing 50 ppm of propionate and 200 ppm of triethanolamine was dissolved in tap water to prepare an aqueous solution with a trioxane concentration of 10% by weight and a pH of 7.5, which was used as a liquid insect repellent. This liquid insect repellent was stored for 6 months and then used against the ant matrix.

Countless red ants were entering the reinforced concrete building from the outside in a procession. Outside the building, 50 ml of the above-mentioned liquid insect repellent was sprayed in a width of about 10 cm within about 30 cm on both sides of the nine rows. A sprayer with a trigger was used for spraying. Immediately after spraying, the lines were disrupted, the ants that had been in the area where the liquid insect repellent was sprayed escaped, and no new ants entered the spray area. This condition continued for at least 2 hours after spraying. However, the next day, the line of red ants was back in shape. Furthermore, no dead ants were seen.

Example 3 and Comparative Example 2 200 ppm of 2,6-di-t-butyl-p-cresol and loopppm of triethanolamine were added as stabilizers to a trioxane melt containing 6 ppm of formic acid and 12 ppm of formaldehyde, and the mixture was dissolved in tap water. hand.

An aqueous solution with a trioxane concentration of 11% by weight and a pH of 7.1 was prepared and used as a liquid insect repellent.

The above liquid insect repellent was used inside the house. This house has a floorboard that can be opened and closed in the kitchen, and the space under the floorboard can be used as a storage area for things like rice bins and cooking oil.

There, they were constantly plagued by cockroaches.

I set up two commercially available sticky cockroach traps under the floor.
On one side, absorbent cotton with a width of 2 cm and a length of 60 cm impregnated with 36 ml of the above-mentioned liquid insect repellent, and on the other side, absorbent cotton with a length of 36 ml of tap water.
Absorbent cotton of the same width and length impregnated with 6 ml of cotton was placed in a ring shape. - When observed after being left for a week, no insects were caught in the trap that was surrounded by absorbent cotton impregnated with liquid insect repellent.

A total of 7 cockroaches of various sizes (1 to 5 cm in body length) were captured in the other trap.

[Effects of the Invention] Although the liquid insect repellent of the present invention is fast-acting and maintains its action for a certain period of time, it does not kill insects. The liquid insect repellent of the present invention is effective against ants, wasps, cockroaches and other insect jaws in general.

Trioxane, the active ingredient, has low toxicity and no persistence, so it does not pollute the environment. Furthermore, since the liquid insect repellent of the present invention is an aqueous solution, it is non-flammable and safe.

Patent applicant: Mitsubishi Gas Chemical Co., Ltd. Representative: Nagano Washo

Claims (1)

[Claims] A liquid insect repellent whose active ingredient is an aqueous solution containing trioxane.