JP2604239B2 - Liquid absorption wick and chemical evaporation method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a liquid absorbent core used in a wicking type heating and evaporating apparatus and a method for evaporating a medicine.

[Conventional technology]

Conventionally, as a method of heating and evaporating a drug for the purpose of insecticide or the like, (1) a so-called mosquito coil and (2) an electric mosquito coil mat have been favored.

In recent years, a system in which a porous liquid absorbent core is immersed in a drug solution and the upper portion of the core is heated to evaporate the drug by heating (hereinafter, referred to as a liquid system) is not required to replace a mat or the like each time.
It has attracted attention again because its effects are stable for a long time.

This method has been known for a long time, and for example, Japanese Utility Model Publication No. 43-25081 describes a method using direct heating. Method tends to be adopted. As a method of indirect heating, a method of heating with a felt or the like between the absorbent core and the heating element has been proposed.
JP-A-12459 and JP-B-46-22585, and a method of heating the liquid-absorbing core and the heating element at a constant interval is disclosed in JP-B-43-26274 and JP-B-44-8361. And JP-B-45-14913 and JP-B-45-292445.

However, the thing at this time had difficulty in long-term sustainability due to clogging of resin and the like, and eventually its advantages were not recognized compared to the mosquito coil and mosquito collecting mat, and it was not accepted by the market. I was

In recent years, this liquid-type mosquito trap has been re-recognized because not only changes in living consciousness and living environment due to improvement of life, but also technological advances in heating elements, development of effective and effective insecticidal ingredients in small amounts, It is thought to be due to the improvement of the quality of pharmaceutical raw materials including ingredients and the progress of plastic processing technology.

[Problems to be solved by the invention]

By the way, as a porous liquid absorbent core used in these liquid heating evaporators, felt was once used as it was, but in the case of felt, generally, the amount of liquid absorbed is too large, storage, transportation, During use, there are problems such as overflow of the chemical solution through the core, or difficulty in correctly setting the core due to its flexibility.

On the other hand, a liquid-absorbent core formed by fixing inorganic powder or inorganic powder and wood powder with a water-soluble glue is disclosed in JP-B-61-23163, JP-B-59-40409, and JP-A-63-24841. No.
This is disclosed in JP-A-63-63330 and JP-A-63-74440. The present inventors have also found a liquid-absorbent core in which calcium carbonate or magnesia or a powder containing organic powder is fixed with a glue, and have previously filed a patent application (Japanese Patent Application No. 63-328526).

However, these conventional liquid absorbent cores are very laborious to manufacture and have many technical difficulties (drying,
(Dimensional stability, reproducibility of performance, etc.) and the shape is limited. Furthermore, water-soluble sizing agents such as starch and CMC-Na are often used for these absorbent cores because they are advantageous in production, but even in this case, when the drug solution is an aqueous solution, the sizing agent is naturally used. However, there remains a problem that the liquid absorbent core is physically deteriorated by dissolution, elution, and swelling of the liquid absorbent, so that it cannot be used.

[Means for solving the problem]

The present inventors have been working diligently, and felt,
Fibers such as cotton, cloth, non-woven fabric, or balsa, lauan,
It is easy to make an absorbent core with a structure that holds the surroundings of timber such as Ramin and bamboo with plastics, metals, glass, inorganic fibers, artificial fibers, ceramics, etc., the volatilization amount is stable, and the adjustment is easy. In addition, it has been found that the drug is not limited to an oily solution but is particularly useful when the drug is an aqueous solution.

That is, the present invention provides a liquid-absorbing core having a structure having a porous liquid-absorbing evaporation layer at the center and a liquid-absorbing or non-liquid-absorbing holding material layer around the liquid-absorbing core.

Further, the present invention provides a liquid-type chemical heating and evaporating method using the absorbent core. Preferably, the drug is heated and evaporated using pyrethroid as a drug, and used for controlling pests such as mosquitoes and flies. The solution containing the drug may be an aqueous solution or an oil solution.

The porous liquid-absorbing vaporized layer is an aggregate of fibers or powder that is stable to a chemical solution and does not decompose the chemical solution at room temperature and the temperature at which the drug is volatilized, and absorbs the chemical solution by capillary action. Specifically, various animal and plant fibers, artificial fibers such as polyester and nylon, cloth, paper, nonwoven fabric, felt, cotton, and the like made of inorganic fibers, balsa, lauan,
Timber with high water absorption, such as Ramin and bamboo, is suitable.

Further, in the present invention, the holding material is a tube-shaped material having mechanically sufficient strength, the material is in contact with a chemical solution, does not cause physical and chemical deterioration even when immersed, and a temperature at which the drug is volatile. Selected from those having sufficient heat resistance. For example, artificial fibers such as polyester and nylon, inorganic fibers, plastics such as polyethylene, polypropylene, and polyvinyl chloride; metals such as copper, brass, iron, stainless steel, and aluminum; ceramics; and glass.

Particularly preferred materials include a glass tube and an artificial fiber tube.

Glass tubes are made by braiding glass fiber into a braiding machine, then simply heat-treated, or coated with varnish or silicone varnish to impart thermal insulation and dried. The size of can be arbitrarily selected.

As the artificial fiber tube, for example, a polyester fiber tube is suitable, but various types are possible depending on the production method, surface treatment such as varnish, or blending with other materials, and can be selected according to the purpose of use.

The holding material is wrapped around the porous liquid absorbing layer, applied, coated, or covered in a bag shape, or formed into a tube, and then cut or stored or stored in the porous liquid absorbing layer. The intended liquid absorbent core can be obtained by means such as fusing.

If necessary, the liquid-immersion portion of the liquid-absorbing core may be replaced with another structure, or a hole may be provided at an appropriate position of the holding material layer to collect the overflowing liquid in a container.

The absorbent core obtained in this manner has an appropriate amount of absorbed liquid and a volatilization rate depending on the material and thickness of the liquid absorption evaporation layer, the type of the holding material, the density of the gap size, the surface area, the material of the coating film, and the like. In addition to being adjustable, the structure is held by the holding material layer, so that the excess amount of liquid absorbed in the conventional liquid absorbent core of felt alone, overflow of the chemical solution during storage, transportation, use, displacement of the liquid absorbent core, etc. And the like can be solved, and it is extremely useful.

The liquid absorbent core of the present invention can be colored with carbon black or another pigment as necessary. Further, antifungal, antiseptic, insect repellent, flame retardant, degreasing, and other treatments may be performed.

The liquid absorbent core of the present invention is suitably used as a liquid absorbent core of a liquid type chemical heating and evaporating apparatus for heating and scattering various kinds of insecticides, bactericides, deodorants, and fragrances for the purpose of insecticide, sterilization, aroma, and the like. Can be used.

An example of an apparatus suitable for using the absorbent core of the present invention is shown in the drawings. In the figure, reference numeral 1 denotes a container containing a chemical solution 2, and the container 1 is detachably housed and held in a storage container 3.
The upper portion of the storage container 3 is open, and an annular (or one-phase semi-annular) heating element 4 is fixed to the opening. 5 is a cord connected to the heating element 4. A liquid inlet 6 is provided at the upper part of the container 1, and a liquid absorbent core 7 is provided in the liquid inlet 6 so that the upper part thereof is disposed substantially in the center of the annular heating element 4. Is held in. The illustrated one is an example of an apparatus suitable for using the liquid-absorbing wick of the present invention, but it is needless to say that an apparatus of various shapes can be used without being limited to this.

As the chemical liquid stored in the container 1, an insecticidal liquid, an aromatic liquid, or the like is used depending on the purpose. When the above-mentioned apparatus is used as a heat transpiration insecticidal apparatus, an insecticide solution is put in the container 1 and the heating element 4 is energized, and the surface temperature of the liquid absorbent core 7 is preferably 70 to 140 depending on the kind of the insecticide. Heat to ℃. If the heating temperature is too high, there is a problem that thermal decomposition and polymerization of the drug are likely to occur, and the amount of the volatilized active ingredient decreases,
In addition, the resulting high-boiling substances and the like are liable to accumulate in the liquid-absorbing core and clogging of the core is liable to occur, which is not preferable. In addition, when the heating temperature is too low, the volatilization of the active ingredient is naturally slowed down. In some cases, only the material is volatilized, and the volatilization of the active ingredient is sometimes hindered.

Therefore, the optimum temperature is selected depending on the type and concentration of the active ingredient, the volatility of the solvent, and the like.

As the insecticide, a solution in which an insecticide is dissolved in various solvents is used. As the solvent, those having a high flash point, no odor, and toxicologically safe are preferred. Further, the boiling point of the solvent used depends on the heating temperature of the absorbent core,
Those falling within the range of 0 to 350 ° C are preferred. Those satisfying these conditions include saturated aliphatic or alicyclic hydrocarbons having 12 or more carbon atoms, and these are commercially available as normal paraffin, isoparaffin or naphthenic hydrocarbon. In addition, as the aromatic hydrocarbon, phenylxylylethane or the like can be used as an odorless solvent. Of course, the solvent is not limited to these hydrocarbons as long as the solvent satisfies the above conditions. For example, various nonionic surfactants, preferably polyoxyalkylene alkyl ether-based solubilizers (which can stabilize insecticidal components in water in a clear state regardless of the presence or absence of micelles, and include ordinary surfactants) In addition to the agent,
It includes solvents that are compatible with water and oil. ) Can be used as an aqueous insecticidal solution to eliminate the problem of flammability.

As the insecticide used in the present invention, various volatile insecticides conventionally used can be used, and examples thereof include pyrethroid-based insecticides, carbamate-based insecticides, and organic phosphorus-based insecticides. Generally, pyrethroid insecticides are preferably used because of their high safety, and examples thereof include the following insecticides.

(A) 3-allyl-2-methylcyclopenta-2-en-4-one-1-yl dl-cis / trans-chrysanthemate (general name: Aresulin, trade name: Pinamine, manufactured by Sumitomo Chemical Co., Ltd.) b) 3-allyl-2-methylcyclopenta-2-en-4-one-1-yl d-cis / trans-chrysanthemate (trade name: Pinamine Forte, manufactured by Sumitomo Chemical Co., Ltd .; hereinafter, insecticide A) (C) d-3-allyl-2-methylcyclopenta-2-
En-4-one-1-yl d-trans-chrysanthemate (trade name: Exulin, manufactured by Sumitomo Chemical Co., Ltd.) (d) 3-allyl-2-methylcyclopenta-2-en-4-one-1 -Yl d-trans-chrysanthemate (generic name bioarrestrin) (e) 2-methyl-4-oxo-3- (2-propynyl) cyclopenta-2-enyl chrysanthemate (f) (S) -2- Methyl-4-oxo-3- (2-propynyl) cyclopenta-2-enyl d-cis / trans-chrysanthemate (general name: plerethrin, hereinafter abbreviated as insecticide B) (g) N- (3,4, 5,6-tetrahydrophthalimido) methyl dl-cis / trans-chrysanthemate (general name: phthalsulin, trade name: neopinamine, manufactured by Sumitomo Chemical Co., Ltd.) (h) 3-phenoxybenzyl 2- (4-ethoxyphenyl) -2-methylpropyl ether (generic name etofenprox) (i) 5-benzyl-3-furylmethyl d-cis / trans-chrysanthemate (generic name resmethrin, trade name Croslon) (J) 5-propargyl-2-furylmethylchrysanthemate (common name frametrine) (k) 5-propargyl-2-furylmethyl d-cis / Trans-chrysanthemate (Pinamine D Forte, manufactured by Sumitomo Chemical Co., Ltd .; hereinafter abbreviated as insecticide D) (l) 3-phenoxybenzyl 2,2-dimethyl-3-
(2,2-dichlorovinyl) cyclopropanecarboxylate (generic name: permethrin, trade name: Exmin, manufactured by Sumitomo Chemical Co., Ltd .; hereinafter abbreviated as insecticide E) (m) 3-phenoxybenzyl d-cis / trans-
Chrysanthemate (generic name phenothrin, trade name Smithline, manufactured by Sumitomo Chemical Co., Ltd., hereinafter abbreviated as insecticide F) (n) α-cyano-3-phenoxybenzyl α-isopropyl-4-chlorophenyl acetate (generic name fenvale Rate, trade name Sumicidin, manufactured by Sumitomo Chemical Co., Ltd.) (o) (S) -α-cyano-3-phenoxybenzyl
(S) -α-isopropyl-4-chlorophenyl acetate (generic name esfenvalerate) (p) (S) -α-cyano-3-phenoxybenzyl
(1R, 3R) -3- (2,2-dichlorovinyl) -2,2-dimethylcyclopropanecarboxylate (q) (RS) -α-cyano-3-phenoxybenzyl
(1RS) -cis / trans-3- (2,2-dichlorovinyl) -2,2-dimethylcyclopropanecarboxylate (generic name cypermethrin) (r) α-cyano-3-phenoxybenzyl d-cis / trans -Chrysanthemate (generic name cyphenothrin) (s) α-cyano-3-phenoxybenzyl 2,2,3,3
-Tetramethylcyclopropanecarboxylate (generic name fenpropatrin) (t) [(pentafluorophenyl) -methyl] (1R, 3
R) -3- (2,2-Dichlorovinyl) -2,2-dimethylcyclopropanecarboxylate (generic name fenfluthrin) (u) 1-ethynyl-2-methyl-2-pentenyl d
-Cis / trans-chrysanthemate (generic name empentrin, hereinafter abbreviated as insecticide G) (v) 3-allyl-2-methyl-cyclopenta-2-en-4-one-1-yl 2,2,3 , 3-Tetramethylcyclopropanecarboxylate (general name teraresulin) (w) 1-ethynyl-2-methyl-2-pentenyl 2,
2,3,3-tetramethylcyclopropanecarboxylate (x) 1-ethynyl-2-methyl-2-pentenyl 2,
2-dimethyl-3- (2,2-dichlorovinyl) cyclopropanecarboxylate (y) N- (3,4,5,6-tetrahydrophthalimido) methyl d-cis / trans-chrysanthemate (brand name Neo Pinamine Forte, manufactured by Sumitomo Chemical Co., Ltd., hereinafter abbreviated as insecticide H) (z) Dimethyl (4-ethoxyphenyl) @ 3- (3-
Phenoxy-4-fluorophenyl) propyl disilane Among these, insecticides A to H are preferable in view of their industrial availability, economy, efficacy and safety, and above all, insecticide D
Are superior in terms of efficacy and economy.

The concentration of the active ingredient in the insecticidal solution is preferably 0.5% by weight or more and 20% by weight or less, and more preferably 0.5 to 8% by weight.

These pesticides may be used alone or in combination.

Further, if necessary, a small amount of a stabilizer, a deodorant, a synergist, a dye, and other auxiliaries can be added to the chemical solution.

Similarly, when used for aroma purposes, various natural and artificial flavors can be used, such as natural animal and / or vegetable flavors, hydrocarbons, alcohols, phenols, aldehydes, ketones, lactones, These are artificial flavors such as oxides and esters. One of these can be used alone, or two or more can be used in combination. Furthermore, various chemicals such as a deodorant, a bactericide, and a repellent can be used depending on the purpose as long as the chemicals are volatilized by heating. As such various drug concentrations
0.5 to 10% by weight is preferred.

〔Example〕

Hereinafter, the present invention will be described based on examples, but the present invention is not limited thereto.

In the following Examples and Comparative Examples, the oil absorption amount is the weight (g) of normal paraffin absorbed per cc of the core, and the oil absorption speed is obtained by cutting the liquid absorption core into 70 mm and cutting the lower 35 mm at room temperature. It refers to the time when normal paraffin reaches the top of the core after being immersed in normal paraffin.

Unless otherwise specified, normal paraffin refers to a fraction having 14 to 16 carbon atoms.

The amount of water absorption and the rate of water absorption are measured in the same manner as described above for an aqueous solution containing 40% by weight of a solubilizing agent (diethyleneoxybutyl ether).

Examples 1 to 9 A cylindrical felt having a diameter of 6 mm and a length of 70 mm, a cloth (cotton 100
%), A silicone glass tube, a polyester fiber tube or a glass tube was wrapped around polyester fiber or glass wool, and processed into the liquid-absorbent core of the present invention. The oil absorption amount, oil absorption speed or water absorption amount and water absorption speed of these liquid absorbent cores were as shown in Table 1.

Comparative Example 1 Diatomaceous earth 100 parts, wood flour (K-100, manufactured by Casino Inc.) 48
Part, activated carbon (Takeda Pharmaceutical Co., Ltd., Shirasagi C) 12 parts, α
274 parts of water was added to 40 parts of starch, kneaded, extruded, and air-dried to obtain a liquid absorbent core having the same dimensions as above. The oil absorption was 0.33 g / cc, and the oil absorption rate was 8 hours.

Comparative Example 2 Similarly, 40 parts of diatomaceous earth, 100 parts of clay, 160 parts of gypsum, CM
A liquid absorbent core having the same dimensions as above was prepared from 8 parts of C-Na and 0.92 parts of Sumilizer-BP-76 (manufactured by Sumitomo Chemical Co., Ltd., antioxidant). The oil absorption was 0.32 g / cc, and the oil absorption rate was 9 hours.

Example of volatilization test Absorbent wicks obtained in Examples 1, 2, 3, 6, and 7 and commercially available absorbent wicks (manufactured by Company A, whose chemicals were washed off with hexane and dried) in a heating evaporator shown in the drawing, and comparison Each of the absorbent cores obtained in Examples 1 and 2 was set, and 35 g of a drug solution obtained by dissolving 1.8% of insecticide D and 1% of BHT in normal paraffin or water containing 40% by weight of diethyleneoxybutyl ether was added. Was heated to 120 ° C. to perform a volatilization test. When the chemical solution became insufficient by the predetermined heating time, only the chemical solution was newly replenished at that time. In the volatilization test, (1) the amount of the chemical solution decreased per hour and (2) the amount of the insecticide volatilized per hour were examined. In (2), the insecticide was trapped with a silica gel packed column at regular intervals, the insecticide was extracted with acetone, and analyzed by gas chromatogram.

 Table 2 shows the results.

1) In the table, the values in the upper row represent the amount of chemical solution volatilized (g / hr).

2) In the table, the values in the lower row represent the amount of pesticide volatilized (mg / hr).

〔The invention's effect〕

As described in detail above, the liquid-absorbent core of the present invention is very easy to manufacture, and is also superior in structure and performance to the conventional one. Is easy.

Therefore, the method for vaporizing the drug of the present invention using the liquid absorbent core also has an effect exceeding that of the conventional method, and can be carried out without physical change of the liquid absorbent core even when the drug is an aqueous solution.

[Brief description of the drawings]

The drawing is a longitudinal section showing one embodiment of an apparatus suitable for carrying out the method of the present invention. In the figure, 1 ... container, 2 ... chemical solution 3 ... container container, 4 ... heating element 5 ... cord, 6 ... chemical liquid inlet 7 ... liquid absorption core

Claims (5)

(57) [Claims] 1. A liquid absorbent core having a structure in which a porous liquid absorbent evaporation layer is provided at the center and a holding material layer is provided around the porous liquid absorbent evaporation layer. 2. A vaporization method in which a solution containing a drug is absorbed into an absorbent core, and the absorbent core is heated to evaporate the drug, wherein the absorbent core is the absorbent core according to claim 1. A method for evaporating a drug, comprising: 3. The method according to claim 2, wherein said solution is an aqueous solution. 4. The method according to claim 2, wherein said solution is an oily solution. 5. The method according to claim 2, wherein the drug is pyrethroid.