JPH0372833A - Liquid-absorbing wick and method for evaporating chemical - Google Patents

Abstract

PURPOSE:To obtain a liquid absorbing wick each having a liquid-absorbing and evaporating layer in the center and retaining material layer around and capable of readily producing and using without physical deterioration of the liquid-absorbing wick even when a chemical is aqueous solution and being stable in evaporating amount of the chemical and capable of readily controlling the chemical amount. CONSTITUTION:The objective liquid-absorbing wick each having a porous liquid- absorbing evaporating layer (e.g. cloth, paper, nonwoven fabric, felt, wool, etc., made of zoatic or vegetable fiber, polyester, nylon, etc.) in the center and a retaining material layer (e.g. plastic such as polyester or nylon, metal such as copper or iron, ceramic or glass) around. An insecticidal liquid is charged to a vessel 1 and heated by applying electricity to a heating element 4 for heating the surface of the liquid-absorbing wick to be preferably up to 70-140 deg.C according to the kind of insecticide.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a liquid absorbent wick used in a suction type heating evaporation device and a method for evaporating a drug.

[Conventional technology]

BACKGROUND ART Conventionally, as methods for heating and evaporating chemicals for the purpose of killing insects, etc., (1) so-called mosquito coils and (2) electric mosquito repellent mats have been popular.

In recent years, the method of immersing a porous liquid-absorbing core in a drug solution and heating the upper part of the core to heat and evaporate the drug (hereinafter referred to as the liquid method) has eliminated the need to replace the mat etc. every time. It has once again attracted attention due to its long-term, stable effects.

This method has been known for a long time, and 1 For example, a method using direct heating is described in Utility Model Publication No. 43-25081, but direct heating causes severe decomposition of the drug, so indirect heating is generally used. The zero-indirect heating method that tends to be adopted involves heating by interposing felt, etc. between the liquid absorbent wick and the heating element.
The method of heating the liquid absorbing wick and heating element by separating them at regular intervals is described in Japanese Utility Model Publication No. 43-26274, Japanese Utility Model Publication No. 44-8361, and Japanese Utility Model Publication No. 45-1491.
It is described in Publication No. 3 and Japanese Utility Model Publication No. 45-292445.

However, the products at that time had problems with long-term sustainability due to clogging of the resin, etc., and in the end, their advantages were not recognized compared to the mosquito coils and mosquito repellent mats, and they were not accepted in the market. It ended in

Recently, this liquid type mosquito repellent has been re-recognized because
In addition to changes in lifestyle awareness and the living environment due to improved lifestyles, technological advances in heating elements have occurred.

This is thought to be due to the development of insecticidal ingredients that are effective in small amounts, improvements in the quality of drug raw materials including active ingredients, and advances in plastic processing technology.

[Problem to be solved by the invention]

Now, in the past, felt was used as it is as the porous liquid-absorbing core used in these liquid-type heating evaporators, but in the case of felt, the amount of liquid absorbed is generally too large, and the amount of liquid absorbed during storage, transportation, etc. There are problems such as the chemical solution overflowing through the wick during use, or the wick being difficult to set correctly due to its flexibility.

On the other hand, a liquid-absorbing core made of inorganic powder or inorganic powder and wood flour, etc., fixed and molded using a water-soluble glue was developed under the Japanese Patent Publication No. 61-23163.
Publication No. 40409/1983, Japanese Patent Application Publication No. 1983-40409
This method is disclosed in Japanese Patent Application Laid-open No. 24841, Japanese Patent Application Laid-open No. 63-63330, and Japanese Patent Application Laid-Open No. 63-74440. In addition, the present inventors also discovered a liquid-absorbent core in which powder containing calcium carbonate, magnesia, or an organic powder was fixed to it with a glue, and filed a patent application (Japanese Patent Application No. 63-32852).
No. 6).

However, these conventional liquid absorbent cores are extremely time-consuming to manufacture, have many technical difficulties (dry dimensional stability, performance reproducibility, etc.), and are limited in shape. There is a problem. Furthermore, water-soluble glues such as starch and CM C-Na are often used for these liquid-absorbent cores because they are advantageous in manufacturing, but even in this case, if the chemical solution is an aqueous solution, it is natural that The problem remains that the absorbent core physically deteriorates due to dissolution, elution, and swelling of the adhesive, making it unusable.

[Means to solve the problem]

The inventors of the present invention, while conducting intensive studies, found that felt, cotton,
It is easy to create a liquid-absorbing core with a structure in which fibers such as cloth, non-woven fabric, or lumber such as balsa, lauan, lamin, and bamboo are held in place by materials such as plastic, metal, glass, inorganic fibers, artificial ays, and ceramics, and they are easy to vaporize. It has been found that the amount is stable and easy to adjust, and that it is particularly useful when the drug is not limited to an oily solution but an aqueous solution.

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

Another aspect of the present invention provides a liquid-type drug heating evaporation method using the liquid-absorbing core. Preferably, a pyrethroid is used as the drug, and the drug is heat-evaporated and used for the purpose of controlling pests such as mosquitoes and flies. In addition, even if the solution containing the drug is an aqueous solution, as a porous liquid absorbing evaporation layer, it can be used at room temperature and at the drug volatilization temperature. , is an aggregate of fibers or powder that is stable against chemical solutions and does not decompose, and absorbs chemical solutions through capillary action.

Specifically, various animal and plant fibers, artificial fibers such as polyester and nylon, fabrics made of non-41!1 fibers, non-woven fabrics, felt, cotton, etc., and highly water-resistant materials such as balsa, lauan, lamin, and bamboo. Timber is preferred.

In addition, in the present invention, the retaining material is a tube-like material that has sufficient mechanical strength, does not undergo physical or chemical deterioration even when it comes into contact with or immerses in a chemical solution, and is maintained at a temperature that allows the chemical to volatilize. 0 selected from those having sufficient heat resistance, for example,
Examples include 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 glass tubes and artificial 111
An example is m-tube.

Glass tubes can be made by simply applying heat treatment to the glass edge wire after being made into a braided tube using a string-making machine, or by applying varnish, silicone varnish, etc. to give it thermal insulation properties and then drying it. The diameter can be arbitrarily selected.

For example, a polyester fiber tube is suitable as an artificial fiber tube, but various types are possible depending on the manufacturing method, surface treatment such as varnish, combination with other materials, etc., and can be selected depending on the purpose of use. .

The above-mentioned porous liquid-absorbing and evaporative layer is wrapped, pasted, and coated with a retaining material, or it is covered in a bag shape, or it is made into a tube-like shape, and the porous liquid-absorbing and transpiring layer is housed and held, and then cut or The desired liquid absorbent core can be obtained by means such as fusing.

If necessary, the chemical liquid immersion part of the liquid absorbent core may be replaced with another structure, or holes may be provided at appropriate locations in the holding material layer to collect overflowing chemical liquid into a container.

In addition to being able to adjust the amount of liquid absorbed and volatilization rate depending on the size, density, surface area, and material of the coating film, etc.

Because it has a structure in which it is held with a retaining material layer, it eliminates the problems associated with conventional liquid-absorbing wicks, such as excessive liquid absorption, overflowing of chemical liquid during storage, transportation, and use, and misalignment of the liquid-absorbing wick. This is extremely useful.

The liquid-absorbent core of the present invention can be colored with carbon black or other pigments, if necessary.

Further, anti-mildew, antiseptic, insect repellent, flame retardant, degreasing, and other treatments may be applied.

The liquid-absorbing core of the present invention is intended for insecticidal, sterilizing, fragrance, etc.
It can be suitably used as a liquid-absorbing core of a liquid-type chemical heating evaporation device that heats and scatters chemicals such as various insecticides, bactericides, deodorants, and fragrances.

In Figure 0, which shows an example of a device suitable for using the liquid-absorbing core of the present invention, l is a container containing a chemical solution 2;
1 is detachably stored and held in the storage container 3.

The upper part of the storage container 3 is open, and a ring-shaped (or a pair of semi-ring-shaped) heating elements 4 are fixed to this open part. 5 is a cord connected to the heating element 4.

A chemical liquid inlet 6 is provided in the upper part of the container 1, and a liquid absorbent wick 7 is inserted into the chemical liquid inlet 6 so that its upper part is disposed in the center of the annular heating element 4. The one shown in the figure, which is held in a tightly sealed manner, is an example of a suitable device for using the liquid absorbent wick of the present invention, but it goes without saying that the device is not limited to this, and devices of various shapes can be used.

As the chemical liquid stored in the container 1, an insecticidal liquid, an aromatic liquid, etc. are used depending on the purpose. When the above device is used as a heat evaporation insecticide, put the insecticidal liquid into the container l,
The heating element 4 is energized and heated so that the surface temperature of the liquid-absorbing core 7 is preferably 70 to 140° C. depending on the type of insecticide. If the heating temperature is too high, there is a problem that thermal decomposition or polymerization of the drug tends to occur, and the amount of volatile active ingredients decreases.
In addition, this is undesirable because high boiling point substances generated as a result tend to accumulate in the liquid absorption core and cause clogging of the core.Also, if the heating temperature is too low, the active ingredients Volatilization becomes slow, and in some cases, only the solvent is volatilized, and the volatilization of the active ingredient may be hindered.

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

As the above-mentioned insecticidal liquid, a solution in which an insecticide is dissolved in various solvents is used. As a solvent, it has a high flash point and has no odor.
It is preferable to use a solvent that is toxic and safe in the palm of your hand.Also, the boiling point of the solvent used depends on the heating temperature of the liquid-absorbing core, but the boiling point is 150
Those within the range of ~350°C are preferred. Those satisfying these conditions include saturated aliphatic or alicyclic hydrocarbons having 12 or more carbon atoms, and these include normal paraffins, imparaffins, and naphthenes. It is industrially available as a hydrocarbon. In addition,
As the aromatic hydrocarbon, phenylxylylethane or the like can be used as an odorless solvent. Of course, as long as the solvent satisfies the above conditions, it is not limited to these hydrocarbons. Regardless of whether the insecticidal ingredient is stabilized in a clear state in water or not, it is made into an aqueous insecticidal liquid by blending it with ordinary surfactants as well as solvents that are compatible with water and oil. It can also solve sexual problems.

As the insecticide used in the present invention, various conventionally used volatile insecticides can be used, including pyrethroid insecticides, carbamate insecticides, organophosphorus insecticides, and the like. Generally, pyrethroid insecticides are preferably used because of their high safety, and examples include the following insecticides.

(a) 3-allyl-2-methylcyclobent-2-en-4-one-1-yl di-cis/trans-chrysanthemate (generic name: allethrin, trade name: pinamine, manufactured by Sumitomo Chemical Co., Ltd.) (b) ) 3-allyl-2-methylcyclobent-2-en-4-one-1-yl d-cis/trans-chrysanthemate (trade name: Pinamin Forte, manufactured by Sumitomo Chemical Co., Ltd., hereinafter abbreviated as insecticide A) ) (c) d-3-allyl-2-methylcycloventer 2-
En-4-one-l-yl d-) Lansu chrysanthemate (trade name Exrin, manufactured by Sumitomo Chemical Co., Ltd.) (d) 3-allyl-2-methylcyclopent-2-en-4-one-1 -yl d-trans-chrysanthemate (-grain temperature bioallethrin) (e) 2-methyl-4-oxo-3-(2-propynyl)cycloventer-2-enyl chrysanthemate (f) (S)-2 -Methyl-4-oxo-3-(2-propynyl)cyclopent-2-enyl d-cis/trans-chrysanthemate (-grain temperature prarethrin, hereinafter abbreviated as insecticide B) (g) N-(3, 4,5,6-titrahydrophthalimido)methyl di-cis/trans-chrysanthemate (generic name: phthalthrin, trade name: neopinamine, manufactured by Sumitomo Chemical Co., Ltd.) (h) 3-phenoxybenzyl 2-(4-ethoxy) phenyl)-2-methylpropyl ether (-Kokuonko Tofenbrox) (i) 5-benzyl-3-furylmethyl d-cis/trans-chrysanthemate (generic name Resmethrin, trade name Crossronforte, Sumitomo Chemical) Manufactured by Kogyo Co., Ltd. (hereinafter abbreviated as insecticide C) (j) 5-propargyl-2-furylmethylchrysanthemate (generic name: flamethrin)
(k) 5-propargyl-2-furylmethyl d-cis/
Trans-chrysanthemate (trade name: Pinamine D Forte, manufactured by Sumitomo Chemical Co., Ltd., hereinafter abbreviated as insecticide) (1) 3-phenoxybenzyl 2,2-dimethyl-3
-(2,2-dichlorovinyl)cyclopropanecarboxylate (-grain vermethrin, trade name Exmin, manufactured by Sumitomo Chemical Co., Ltd., hereinafter abbreviated as insecticide E) (m) 3-phenoxybenzyl d-cis/tran Sucrysanthemate (generic name Phenothrin, trade name Sumitrin, manufactured by Sumitomo Chemical Co., Ltd., hereinafter abbreviated as Insecticide F) (n) α-cyano-3-phenoxybenzyl α-inpropyl-4-chlorophenylacetate (general (o)(S)-α-cyano-3-phenoxybenzyl
(S)-α-isopropyl-4-chlorophenylacetate (-kokuonkosfenvalerate) (p)(S)-α-cyano-3-phenoxybenzyl
(lR,3R)-3-(2,2-dichlorovinyl)-2
,2-dimethylcyclopropanecarboxylate (q)(R3)-α-cyano-3-phenoxybenzyl (IR3)-cis/trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxy rate (-cypermethrin) (r) α-cyano-3-phenoxybenzyl d-cis/
Trans-chrysanthemate (-grain temperature cyphenotrin) (S) α-cyano-3-phenoxybenzyl 2.2,3
．． 3-tetramethylcyclopropanecarboxylate (
-grain temperature fenpropathrin) (t) ((pentafluorophenyl)-methyl) (IR,3R)-3-(2,2-
dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate (-some names phenfluthrin) (u)l-
Ethynyl-2-methyl-2-pentenyl d-cis/trans-chrysanthemate (generic name: empenthrin, hereinafter abbreviated as insecticide G) (v) 3-allyl-2-methyl-cyclobenter-2-ene-4- On-1-yl 2,23.3-tetramethylcyclopropanecarboxylate (-grain terrarethrin) (w) l-ethynyl-2-methyl-2-pentenyl 2
, 2,3.3-tetramethylcyclopropanecarboxylate (x) l-ethynyl-2-methyl-2-pentenyl 2
．． 2-dimethyl-3-(2,2-dichlorovinyl)cyclopropanecarboxylate (y)N-(3,4,5,
6-titrahydrophthalimido) methyl d-cis/trans-chrysanthemate (trade name Neopinamine Forte, manufactured by Sumitomo Chemical Co., Ltd., hereinafter abbreviated as Insecticide H) (2) Dimethyl (4-ethoxyphenyl) (3-(3-
Phenoxy-4-fluorophenyl)propyl)silane Among these, insecticides A to H are preferred in terms of industrial availability, economic efficiency, efficacy, and safety.

Among them, insecticides are superior in terms of efficacy and economy.

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

These insecticides may be used alone or in combination.

In addition, stabilizers, deodorants, synergists, pigments,
Small amounts of other auxiliaries can also be added to the drug solution.

Similarly, when used for aromatic purposes, a variety of natural and artificial fragrances can be used, such as natural fragrances of animal and/or vegetable origin, hydrocarbons, alcohols, phenols, aldehydes, ketones, lactones, These include artificial fragrances such as oxides and esters, and one type of these can be used alone, or two or more types can be used in combination. Furthermore, depending on the purpose, various chemicals such as deodorants, disinfectants, and repellents can be used as long as they are volatilized by heating. The concentration of these various drugs is 0.
．． 5 to 10% by weight is preferred.

〔Example〕

The present invention will be described below based on Examples, but the present invention is not limited thereto.

In addition, in the following Examples and Comparative Examples, the oil absorption amount refers to the weight of normal paraffin absorbed per 1 cc of core (3
), and the oil absorption rate refers to the time it takes for normal paraffin to reach the core ring when a liquid absorbent core is cut into 70 mm pieces and its lower 35 mm is immersed in the norm + u < rough-in at room temperature.

Unless otherwise specified, normal paraffins refer to fractions having 14 to 16 carbon atoms.

The water absorption amount and water absorption rate were measured in the same manner as above for an aqueous solution containing 40% by weight of a solubilizer (diethylene oxybutyl ether).

Examples 1 to 9 Cylindrical felt with a diameter of 6 mm and a length of 70 mm, cloth (cotton 1
00%), boso ester m fiber or glass cool was wound with a silicone glass tube, polyester ta fiber tube or glass tube to form the liquid absorbent core of the present invention.

The oil absorption amount, oil absorption rate, or water absorption amount and water absorption rate of these liquid absorbent cores were as shown in Table 1.

Table 1 Comparative Example 1 100 parts of diatomaceous earth, wood flour (manufactured by Casino Co., Ltd., K-100
) 48 parts, activated carbon (manufactured by Takeda Pharmaceutical Co., Ltd., white fic) 1
2 parts, 40 parts of α-starch and 274 parts of water were added and kneaded,
This was extruded and air-dried to obtain a liquid absorbent core having the same dimensions as above.

The oil absorption amount 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
Department, CM C-N a 8MA, Sumilizer BP-7
6 (manufactured by Sumitomo Chemical Co., Ltd., antioxidant) 0.92
A liquid absorbent wick having the same dimensions as above was prepared from the above. The oil absorption amount was 0.32 g/cc, and the oil absorption rate was 9 hours.

Volatilization test example The liquid absorbent wicks obtained in Examples 1, 2, and 3゜6.7, commercially available liquid absorbent wicks (manufactured by Company A, washed with hexane and dried), and comparison were placed in the heating evaporator shown in the drawing. The liquid-absorbing cores obtained in Examples 1 and 2 were set, and 1.8% insecticide D was added.
, 35 g of a chemical solution containing 40% by weight of normal paraffin or diethylene oxybutyl ether dissolved in water was added, and the side of the core was heated to 120"c! to conduct a volatilization test. When the chemical solution was insufficient, only a new chemical solution was replenished at that point.The volatilization test examined (1) the amount of chemical solution decreased per hour and (2) the amount of pesticide volatilized per hour.In (2), the amount of pesticide volatilized was constant. The insecticides were trapped with a silica gel-packed column every hour, extracted with acetone, and analyzed by gas chromatography.

The results are shown in Table 2.

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

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

〔Effect of the invention〕

As explained in detail above, the liquid absorbent core of the present invention is very easy to manufacture, and is superior in structure and performance to conventional ones. Easy to adjust.

Therefore, the drug evaporation method of the present invention using this liquid-absorbing wick also exhibits effects superior to conventional methods, and can be carried out without physical deterioration of the liquid-absorbing wick even when the drug is an aqueous solution.

[Brief explanation of drawings]

The drawing is a longitudinal sectional view of an embodiment of an apparatus suitable for carrying out the method of the invention. In the figure, 1... Container 2... Chemical solution 3... Storage container 5... Code 4... Heating element 6... Chemical solution inlet 7... Liquid absorbing core Dainippon Yomugiku Co., Ltd. company

Claims (5)

[Claims] (1) A liquid-absorbing core with a structure having a porous liquid-absorbing evaporation layer in the center and a retaining material layer around the periphery. (2) In a transpiration method in which a solution containing a drug is absorbed into a liquid absorbent core and the liquid absorbent core is heated to evaporate the drug, the liquid absorbent core is the liquid absorbent core according to claim 1. Characteristic drug evaporation method. (3) The method for evaporating a chemical according to claim 2, wherein the solution is an aqueous solution. (4) The method for evaporating a drug according to claim 2, wherein the solution is an oily solution. (5) The method for evaporating a drug according to claim 2, 3 or 4, wherein the drug is a pyrethroid.