JPH0123441B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a sublimable insect repellent that is solid at room temperature. [Prior Art and Problems to be Solved by the Invention] Conventionally, p-dichlorobenzene, naphthalene (naphthalene), and the like have been used as sublimation insect repellents. These insect repellents are widely used in general households, mainly as insect repellents for clothing, for example, to prevent damage to clothing caused by bur moths and Japanese burrs. Among them, p-dichlorobenzene has great insecticidal power, is fast-acting, and is relatively inexpensive, so it has been the mainstream of household insect repellents. In general, such insect repellents are required to have a long-term insect repellent effect in the space in which they are used, usually for several months, and to be harmless to the human body and not cause discomfort. . p-dichlorobenzene has been most often used as it satisfies these conditions to some extent. Measures such as adding fragrances have been taken to combat the pungent odor characteristic of p-dichlorobenzene. However, recently, environmental pollution due to p-dichlorobenzene has started to become a problem. That is, p
-Dichlorobenzene, like polychlorobiphenyl (RCB), belongs to aromatic chlorine compounds, and because it is more stable than necessary and difficult to decompose, it remains extremely persistent in the environment. According to a survey, P can be transmitted not only indoors but also from open spaces and wooded areas 80 meters away from houses.
-Dichlorobenzene was detected. p-Dichlorobenzene is also subject to a comprehensive chemical safety inspection by the Environment Agency. Furthermore, p-dichlorobenzene is said to cause liver damage, lung granulomas, cataracts, dermatitis, and the like. Moreover, the disadvantage of p-dichlorobenzene as an insect repellent for clothing is that it contains chlorine atoms in the molecule.
Gold threads and silver threads (made of silver or aluminum, etc.) in clothing may turn black.
To avoid this, naphthalene and aluminum have been used, but their sublimation rate is low, so they are not suitable for storage boxes that are opened and closed many times. Naphthalene is also an aromatic compound, and its toxicity and persistence are similar to p-dichlorobenzene. It emits a unique odor worse than naphthalene or p-dichlorobenzene. [Means for solving the problems and their effects] As a result of repeated research to develop a sublimation insect repellent that is free from the various problems mentioned above, the present inventors have found 1.
The present invention was completed by discovering that 3,5-trioxane (hereinafter simply referred to as trioxane) meets the purpose. That is, the present invention is a solid insect repellent containing trioxane as an active ingredient. In order to fully utilize the properties of trioxane, the trioxane content in the insect repellent should preferably exceed 99% by weight.
Furthermore, it is preferable to use trioxane with as high a purity as possible. Highly purified trioxane has a weak chloroform-like pleasant odor. In order to take advantage of this pleasant aroma and maintain the storage stability of trioxane, it is preferable that the amount of formic acid, which is an impurity in trioxane, is 20 ppm or less.
Particularly preferred is 10 ppm or less. Similarly, formaldehyde is preferably 50ppm or less, and 20ppm
The following are particularly preferred. Trioxane may also contain polyoxymethylene dimoxides as impurities, but these compounds have little effect on performance such as aroma, storage stability, and insect repellency. In order to further increase 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, thiocarbamoyl compounds, and organic trivalent phosphorus compounds. and so on. The amount of these stabilizers added varies depending on the type of stabilizer and other conditions, but is usually about 1 to 1000 ppm. There are no particular restrictions on the sterically hindered phenol, and it may be relatively low molecular weight such as 2,6-di-t-butyl-p-cresol, but considering its use as an insect repellent, Preferably, the stabilizer has low volatility. For example, among the sterically hindered phenols, pentaerythritol-tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3(3,5 -di-t-butyl-4
-hydroxyphenyl)propionate], and triethylene glycol-bis[3-(3-t
-butyl-4-hydroxy-5-methylphenyl)propionate] and the like are particularly preferred. Among the amines, high boiling point amines such as ethanolamines, particularly triethanolamine, are preferred. If desired, a small amount of flavoring agent can be added to the insect repellent of the present invention, but this is not strictly necessary since trioxane has its own pleasant scent. Further, a drug having a stronger insect repellent or insecticidal effect than trioxane can be added, but trioxane alone as an active ingredient is sufficient for the insect repellent effect. Since trioxane itself has a high sublimation rate, it has sufficient rapid action and the sublimation rate can be adjusted over a wide range under the conditions of use. By packaging the insect repellent in a membrane material and removing part of it when using it,
Sublimation can be limited to extend the period of use. The more stable the membrane material is physically and chemically, the better.
Usually, stability of polyethylene, polypropylene, cellophane, or polyvinylidene chloride is sufficient.
Polyethylene and polypropylene are preferred membrane materials. The sublimation rate can also be adjusted by using a breathable membrane material such as a porous film or paper. As a packaging form, disc-shaped pellets can be packed in a rectangular shape, similar to the p-dichlorobenzene preparation. In addition, if the cylindrical pellets are packaged in such a way that the sides are tightly covered and a space is provided on at least one side of the bottom of the cylinder, the cross-sectional area of which gradually decreases as the distance from the bottom surface increases, the pellets can be packed at appropriate locations. The sublimation rate can be adjusted by cutting the packaging material to create an opening with an appropriate area. Trioxane can be used in powder or granule form or as shaped articles. For example, shaping into pellets can be carried out by compression molding of trioxane powder or by casting or extrusion molding of molten trioxane. The insect repellent of the present invention exhibits an insect repellent action not only against clothing pests but also against other insects such as cockroaches and ants. Furthermore, the insect repellent of the present invention does not cause the gold threads and silver threads of clothing to turn black. Furthermore, the insect repellent of the present invention can also be used as a fuel. In this case, the insect repellent of the present invention may be filled into a can, and the insect repellent can be used with a small opening, and the fuel can be ignited with a larger opening. The trioxane used in the present invention has a melting point of 64°C,
It is a substance with the molecular formula C ₃ H ₆ O ₃ and is a sublimated solid that is stable in air at room temperature. The acute toxicity of trioxane is low, and the intraperitoneal lethal dose for mice is approximately 8,500 mg/Kg. The non-mutagenicity of trioxane has been demonstrated in mice, rats, Drosophila, and Salmonella enterica. Trioxane also has no anesthetic properties. In this way, trioxane is a conventional insect repellent p-
It is a safer substance than dichlorobenzene and naphthalene. Also, trioxane has low persistence and therefore low environmental pollution. Trioxane is clearly distinguished from conventional insect repellents in the following ways: All three, p-dichlorobenzene, naphthalene, and sulfur, produce a black, sooty flame when combusted. In particular, p-dichlorobenzene burns while emitting chlorine-based toxic gas because of its chlorine content. Furthermore, all three of these substances are oil-soluble and insoluble or extremely sparingly soluble in water. Although trioxane has poor solubility in saturated hydrocarbons, it dissolves well in various other organic solvents, and also dissolves well in water. However, it is not deliquescent. What also sets trioxane apart from other insect repellents is that it produces a soot-free blue flame when burned. Although trioxane has a weaker insecticidal power than p-dichlorobenzene, it has sufficient repellency against trioxane for insects, and is sufficient for insect repellent performance. The present invention provides a safe insect repellent by fully utilizing the characteristics of trioxane. [Example] Next, the present invention will be explained in more detail with reference to Examples. Example 1 Trioxane powder containing 6 ppm of formic acid and 10 ppm of formaldehyde and having a purity of 99.9% by weight or more was compression molded to prepare an insect repellent in the form of white disc-shaped pellets with a diameter of 20 mm and a thickness of 5 mm. This insect repellent had the pleasant scent of trioxane. The cockroach, which has a large escape tendency, was selected as the experimental insect. One adult cockroach weighing 0.84 g was placed in a glass bottle with an inner diameter of 6 cm and a volume of 150 ml, and a piece of fried noodles with a length of 2 cm was given as bait. The insects quickly finished eating the food, so more food was added. During the insect's feeding behavior, one of the insect repellents described above was gently placed at a position away from the insect. Within one minute, the insects escaped from the bottom of the bottle, passed through a polyethylene film tube that had been connected to the mouth of the bottle, and reached the insect cage at the end. Next, the insects were returned to the original bottle without damaging the insects, the bottle was covered with a metal lid, and the bottle was placed in a dark place. The lid had five holes with a diameter of 2 cm as ventilation holes. The course of events thereafter was as follows. 15 minutes later, the insects were behind the top lid of the bottle and appeared to be avoiding the trioxane. After 1 hour and 15 minutes, the insect fell to the bottom and was struggling with its belly facing up. The insect was gently picked up with tweezers and returned to its normal position. Three hours later, the insect was barely moving and was on the verge of death. After 24 hours, the insects were dead. Example 2 18 ppm formic acid and 40 ppm formaldehyde and triphenylphosphine as stabilizer
Particulate trioxane with a trioxane content of 99.2% by weight or more containing 300 ppm and a particle size of 2 to 5 mm was used as an insect repellent sample. There was no strange odor in the sample. We selected ants, which are highly aggregative, as experimental insects. The bottoms of six test tubes with a diameter of 24 mm and a length of 200 mm were filled with absorbent cotton impregnated with a 10% by weight granulated sugar aqueous solution, and placed horizontally with the mouths facing north on the ground in the shade where the brown ants are active. . Label the test tubes A to F in order from the east side, and set the intervals between each test tube to be 3 cm for A-B and E-F, and 3 cm for B-C and D-.
E was 6 cm, and CD was 9 cm. In test tube B
0.2g, 0.4g for D and 0.5g for E,
It was placed 2 cm inside the mouth of the test tube. 1 hour
When observed after 30 minutes, a large number of ants had gathered in a pattern in test tubes A, C, and F, which had not been treated with trioxane. Test tubes D and E containing trioxane contained no insects at all. Test tube B with a small amount of trioxane
There were two ants in there, but they weren't lining up. The two ants were not attached to the cotton wool and were wandering around in the middle of the test tube, seemingly unable to get out of the test tube. Example 3 8 ppm formic acid and 15 ppm formaldehyde and 100 ppm pentaerythritol-tetrakis [3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] as stabilizer and mixed ethanolamine (2% by weight monoethanolamine) An insect repellent in the form of white disk-shaped pellets with a diameter of 20 mm and a thickness of 5 mm was prepared by compression molding a trioxane powder having a trioxane content of 99.5 wt. Six brown ants with a body length of approximately 3 mm were placed in a 200 ml glass bottle, and a small piece of absorbent cotton impregnated with a 5% by weight aqueous granulated sugar solution was given as bait. Next, the insect repellent was placed in a glass bottle without touching the absorbent cotton. Cover the mouth of the bottle with a cotton cloth and secure it with a rubber band.
The lid is breathable. The course of events thereafter was as follows. Within 10 minutes, all six of them left the absorbent cotton, reached the top, and attached themselves to the back of the cotton cloth. After 30 minutes, the movement slowed down behind the cotton cloth. One hour later, all six of them had fallen to the bottom. The three animals were moving on cotton wool. The other three animals showed slow movement on the glass bottom. Two hours later, all six animals appeared to be dying on the glass bottom. 18 hours later, all of them were dead. Example 4 9 ppm formic acid and 12 ppm formaldehyde and 500 ppm 2,6-di-t-butyl-p-cresol and triethanolamine as stabilizers.
200g of trioxane melt with a trioxane content of 99.3% by weight or more including 100ppm was heated to an inner diameter of 8.2cm high.
It was injected into 3.6cm tin cans and canned. After the contents had solidified, about a quarter of the circumference of the bottom of the can was opened with a can opener and used as an insect repellent. Then, open the entire bottom of this can, which was already partially opened, and place it under a stainless steel beaker with a diameter of 14 cm placed on a tripod with a distance of 2 cm between the bottom of the beaker and the opening of the can. I placed it like this. I put 500g of water at 25°C into a beaker, covered it with a watch glass, and ignited the insect repellent in the can with a stick. The insect repellent ignited easily and burned with a soot-free blue flame. No strange odor was generated during combustion. Water reached boiling point 14 minutes after ignition. After boiling for 16 minutes, the can was put on a steel lid and the fire was extinguished. Trioxane weight loss during combustion is 66g;
The weight loss of water in the beaker was 64 g. Also, no soot was attached to the bottom of this beaker. Example 5 7 ppm formic acid and 9 ppm formaldehyde and triethylene glycol-bis- as stabilizer
[3-(3-t-Butyl-4-hydroxy-5-methylphenyl)propionate] A trioxane melt containing 80 ppm of trioxane and 20 ppm of triethanolamine and having a trioxane content of 99.8% by weight or more is injected into a mold and solidified to form a bottom diameter. Two insect repellents in the form of white cylindrical pellets measuring 10 mm in height and 30 mm in height were prepared. One of the insect repellents was placed in a polyethylene film tube of the same diameter (film thickness 0.04 mm) to cover the sides. Next, the open end of the tube was melt-cut while being heated and stretched, and the tube was crimped and sealed into a conical shape. Prepare two 500ml beakers, each with a diameter of 10cm.
A piece of aluminum foil having a thickness of 15 μm was placed on one side, and on the other side, coated pellets with an opening cut approximately in the center of the conical part of the package were placed, and uncoated pellets were placed on the other side. The beaker was sealed with polyethylene film and left at room temperature in summer for 3 months. No abnormality occurred on the surface of the aluminum foil, including the surface that was in contact with the uncoated pellets. Examples 6-7 and Comparative Examples 1-6 5 ppm formic acid and 8 ppm formaldehyde and 50 ppm 1,6-hexanediol-bis[3(3,5-di-t-butyl-4-hydroxyphenyl)propionate] as a stabilizer. and trioxane content including 8 ppm triethanolamine
A white disc-shaped insect repellent having a diameter of 20 mm and a thickness of 5 mm was prepared by compression molding trioxane powder containing 99.9% by weight or more. This was subjected to a test against clothing pests. Put 10 insect pests and a piece of 3cm square wool woven cloth into a 500ml glass bottle, place one insect repellent pellet away from the wool woven cloth, seal the bottle, and cool to a temperature of 24°C.
It was left undisturbed in a dark place at ~26°C. For comparison, commercially available insect repellents p-dichlorobenzene and naphthalene (both 21 mm in diameter, flat disk-shaped pellets) and the case without insect repellent were similarly tested. The degree of feeding damage to the wool woven fabric was evaluated by inspection in the following four grades. A... No feeding damage B... Only traces of feeding damage C... Intermediate between B and D D... Severe feeding damage, degree of feeding damage without insect repellent When targeting burr larvae with a body length of about 6 mm as a pest (Example 6 and Comparison) The results of Examples 1 to 3) are shown in Table 1, and the results are shown in Table 1.
The results of 6) are shown in Table 2.

【table】

[Table] [Effects of the Invention] The insect repellent of the present invention has a large insect repellent effect, has no pungent odor, and has a rather pleasant fragrance, and is harmless to the human body.
Will not discolor silver thread. Furthermore, the insect repellent of the present invention can also be used as a fuel.

Claims (1)

[Claims] 1. A solid insect repellent containing trioxane as an active ingredient. 2. The solid insect repellent according to claim 1, wherein the trioxane content exceeds 99% by weight.