JPH04200336A - Liquid-sucking wick for thermal evaporation - Google Patents

Abstract

PURPOSE:To obtain the subject liquid-sucking wick having excellent wick strength and dimensional stability and capable of effectively and stably dissipating an agent over a long period by mixing inorganic and/or organic powder with a binder carbonizable by high-temperature baking and baking the mixture after forming. CONSTITUTION:An inorganic powder and/or organic powder (e.g. cellulose powder) and optionally other additive are mixed with a binder (e.g. tar) carbonizable by high-temperature baking. The mixture is formed and baked to obtain the objective liquid-sucking wick 7 for thermal evaporation of an agent. The lower part of the liquid-sucking wick 7 is immersed in a liquid agent 2 (e.g. insecticide) contained in a container 1 to effect the suction of the liquid agent 2 into the liquid-sucking wick 7. At the same time, the top of the liquid-sucking wick 7 is heated with a heater 4 to evaporate the absorbed liquid agent 2. There is no dissolution and swelling of the binder in the liquid- sucking wick 7 with the liquid agent 2 and, accordingly, the clogging and the deterioration of the liquid-sucking wick 7 can be prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a liquid absorbent wick for heating transpiration, and more specifically,
A chemical liquid that is absorbed by immersing a part of a liquid-absorbing wick in a chemical liquid, absorbing the liquid into the wick, and heating the upper part of the wick, for the purpose of killing insects, sterilizing, deodorizing, fragrance, etc. This invention relates to a liquid absorbent wick used in a suction type heating evaporation device that evaporates water.

[Conventional technology]

For example, a heating method in which a part of a porous liquid-absorbing wick is immersed in an insecticidal liquid to absorb the insecticidal liquid into the wick, and the absorbed insecticidal liquid is evaporated by heating the upper part of the wick. The method of killing insects by transpiration has been known for a long time. For example, Japanese Utility Model Publication No. 43-25081 describes a method using direct heating, but direct heating causes severe decomposition of the drug, so indirect heating is generally preferred. As a method using indirect heating, a method of interposing felt or the like between the liquid absorbing wick and the heating element is disclosed in Japanese Utility Model Publication No. 36-12459 and Japanese Utility Model Publication No. 48-22585.
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. 43-28274, Japanese Utility Model Publication No. 44-8361, and Japanese Utility Model Publication No. 45-1491.
Publication No. 3, Utility Model Publication No. 19801, Utility Model Publication No. 45
-29244 publication, Japanese Patent Publication No. 61-23183,
It is described in JP-A-60-161902 and the like.

In addition, Japanese Patent Publication No. 81-23183 discloses that allethrin or its isomer is used as an insecticide, an insecticidal liquid prepared by dissolving it in a hydrocarbon solvent with a specific boiling point range is used, and as a porous liquid-absorbing core, Porous porcelain, inorganic fibers selected from asbestos hardened with gypsum and/or bentonite, as well as kaolin, talc, diatomaceous earth, perlite, bentonite, alumina, silica,
It has been proposed to use a liquid absorbent core made of an inorganic powder selected from silica alumina and titanium hardened with starch.

Furthermore, JP-A-60-161902 proposes an insecticidal liquid composition for liquid absorbent cores in which a specific antioxidant is added to an insecticide solution.

[Problem to be solved by the invention]

In the case of the heating transpiration method using the liquid absorbent core heating method described above, since the porous liquid absorbent core is generally made of felt, nonwoven fabric, asbestos, etc., the liquid absorption rate is relatively fast and the liquid absorbent core is heated. As time passes, only the solvent in the chemical solution evaporates, making it difficult for the drug to evaporate sufficiently, and high boiling point substances generated by thermal decomposition of the drug or high boiling point substances contained in the solvent may cause eye contact with the liquid absorption core. Since clogging is likely to occur, it has been difficult to maintain stable volatilization over a long period of time.

On the other hand, the above-mentioned Japanese Patent Publication No. 61-23183 proposes a method to improve to some extent the problem that only the solvent in the insecticidal liquid evaporates and stable insecticidal volatilization is difficult, and examples of the method are proposed. describes the use of a ceramic porous core as a liquid absorbent core. However, in general, ceramics need to be fired at extremely high temperatures and for a long time in order to ensure sufficient strength, and the cost of raw materials is also high, leading to problems such as increased manufacturing costs.
Even if the drug has good transpiration properties and strength, it has not yet been found to be satisfactory economically in terms of manufacturing cost, productivity, etc.

Therefore, in the heating evaporation method using the liquid absorbent core heating method, a liquid absorbent core formed from inorganic powder is generally used, and the method for manufacturing such a liquid absorbent core is as follows.
A commonly used method is to knead inorganic powder with starch, semi-synthetic cellulose derivatives, carboxymethylcellulose (CMC), or other binders with water or hot water, and then extrude the mixture (see Japanese Patent Publication No. 81-23183 mentioned above). ).

However, when inorganic powder is simply hardened with a small amount of starch, the strength of the absorbent core is very weak and the moldability is poor, making it extremely difficult to manufacture the absorbent core. If this were to be done, a large amount of starch would be required and various problems would arise.

That is, starch is generally stored starch from plants, and pure starch is usually a mixture of about 80% amylose and about 20% amylopectin, which is insoluble in cold water and can be heated to 50-70°C. It becomes a viscous glue. However, the viscosity varies greatly depending on the temperature, and this change in viscosity can cause problems during production.Depending on the cooling method and concentration, problems such as starch aging, or the formation of micelles due to the orientation of amylose, and troubles due to the growth of mold, can occur during production. This has the disadvantage that it is difficult to ensure the stability of the product, as it may cause insufficient strength or strength deterioration later on. In addition, in order to improve the strength of the liquid absorbent core, it is necessary to use a large amount of starch, but as the amount increases, the liquid absorbent core loses its porosity, making it difficult to absorb the chemical solution and resulting in insufficient transpiration. It has its drawbacks. On the other hand, in the case of CMC, the purpose can be achieved by using a small amount compared to starch, but when both CMC and starch are heated while sucking up a chemical solution for a long time, decomposition etc. progress, resulting in strength deterioration. Furthermore, deterioration of binders such as starch and CMC affects the transpiration, decomposition, and polymerization of drugs, resulting in the problem that stable transpiration cannot be obtained over a long period of time.

Furthermore, the solidification state of water-soluble polymers such as starch and CMC changes depending on the humidity of the environment. In other words, when the humidity is high,
When these water-soluble polymers contain water, they become soft and the strength of the liquid absorbent core is significantly impaired.

In addition, if the liquid absorbent core is immersed in a chemical solution for a long period of time or heated while sucking up a chemical liquid, water-soluble polymers may be absorbed into the chemical liquid impregnated into the liquid absorbent core or even in the chemical liquid present around the core. It dissolves or swells in the liquid and gradually closes the voids (pores) in the porous liquid-absorbing core, making it difficult to absorb the chemical solution in a relatively short period of time, making it difficult to achieve stable transpiration over a long period of time. It becomes difficult.

In addition, absorbent cores molded using binders such as starch and CMC tend to crack or bend during the drying process after molding, and also require a long drying time. The dimensional stability of the liquid core was also poor, making it difficult to efficiently produce a liquid absorbent core of stable quality.

Furthermore, liquid absorbent cores using water-soluble polymers such as starch and CMC as binders cannot be used for aqueous chemical solutions because these binders have insufficient water resistance. A measure to solve this drawback is JP-A-2-
No. 231031 and Japanese Patent Application Laid-open No. 2-234 [F28], but the liquid absorbent core described in Japanese Patent Application No. 2-231031 has stabilized quality because it is used by cutting natural wood. is extremely difficult. On the other hand, JP-A-2-
The liquid absorbent core described in Japanese Patent No. 234628 has a double structure consisting of a central holding material and a surrounding porous liquid absorbent evaporation layer, so it has the disadvantage of requiring complicated molding processes.

Therefore, the purpose of the present invention is to solve the above problems and
To provide a liquid absorbent wick for heating and evaporation that hardly causes clogging of the liquid absorbent wick during heating use and can effectively transpire a sufficient amount of a drug over a long period of time.

Furthermore, the object of the present invention is to solve the problems caused by the binder as described above, and to provide a heating transpiration product that has excellent core strength, dimensional stability, and moldability, and that can be used regardless of whether the chemical is oil-based or water-based. Our purpose is to provide a liquid absorbent core.

A further object of the present invention is to provide a liquid absorbent wick for heating evaporation that can be manufactured with high productivity at low manufacturing cost and with constant quality.

[Means to solve the problem]

The liquid-absorbing wick for heating transpiration of the present invention absorbs the chemical liquid into the wick by immersing a part of the liquid-absorbing wick in a chemical liquid, and evaporates the absorbed chemical liquid by heating the upper part of the wick. It is a liquid-absorbing core used in the heating evaporation method, which is made by molding and firing a mixture of inorganic powder and/or organic powder mixed with a binder that can be carbonized by high-temperature firing along with other additives as necessary. It is characterized by certain things.

It is particularly preferable to use tar, pitch, or a mixture thereof as the binder, and it is particularly preferable that the firing temperature is 450 to 1300° C. on the surface of the core.

[Operation and mode of the invention]

The liquid absorbent core for heat evaporation of the present invention is manufactured by molding and firing a mixture of an inorganic powder and/or an organic powder, a binder that can be carbonized by high-temperature firing, and other additives as necessary. Therefore, it can be manufactured with relatively high productivity, and the binder is carbonized and stabilized by firing, and since the powders are firmly bonded together, it has excellent core strength and dimensional stability.

In addition, when actually using a liquid absorbent wick for heating transpiration, one end of the liquid absorbent wick is immersed in a chemical solution, and for example, when an insecticide is used as an active ingredient, the wick surface temperature is 100 to 130°C. Generally, it is heated to At this time, CMC
, when using a liquid-absorbing core obtained by simply extruding and drying a mixture containing a water-soluble polymer such as starch as a binder, as mentioned above, the absorption caused by the dissolution or swelling of the binder by the chemical solution may occur. Although it has not been possible to completely avoid the clogging and deterioration of the liquid core, as well as the adverse effects on drug transpiration due to deterioration of the water-soluble polymer itself when heated to 100 to 130°C, as in the present invention, Liquid absorbent cores manufactured by firing are free from such problems. In other words, the binder is carbonized by firing and is stable, so it hardly dissolves or swells with chemicals, and since it is used at a temperature much lower than the firing temperature, the carbonized binder itself hardly ever deteriorates. do not. Therefore, there is no clogging of the liquid absorption core due to dissolution or swelling of the binder, and there is no adverse effect on drug transpiration due to deterioration of the binder itself, and sufficient drugs can be effectively and stably evaporated over a long period of time. can.

Furthermore, since the liquid absorbent wick for heating evaporation of the present invention has good dimensional stability as described above, it is possible to reduce liquid leakage during use. In other words, liquid leakage during use can be classified into two types: those caused by the flow of liquid inside the liquid-absorbent wick, and those caused by the gap between the liquid-absorbent wick and the container. This allows for tighter fitting with fewer gaps between the two, reducing fluid leakage.

The carbonizable binder used in the present invention includes tar, pitch, methylcellulose/hydroxypropylmethylcellulose copolymer (MC-HPMC), polyvinyl alcohol (PVA), polyvinyl butyral (PV
B), polymethyl methacrylate (PMMA), acrylic resin, polystyrene (PS), polypropylene (PP), polyethylene (PE), ethylene vinyl acetate copolymer (EVA), phenolic resin, polyethylene glycol (PEG), cellulose derivatives, CMC
, starch, urethane, wax, wax emulsion, etc. Among these, it is particularly preferable to use tar, pitch, or a mixture thereof.

In other words, when tar, pitch, or a mixture thereof is used, the residual carbon derived from these binders after firing has an excellent function of acting as a binder, so it is easier to achieve good strength than when using other binders. It has the advantage that it can be obtained from Also, these binders are
It is generally cheaper than other resins, and when mixed or extruded using these resins, molded products are extremely less sticky, easy to handle, and dimensionally stable, making high-speed molding possible. The production efficiency is much better than that of a general ceramic liquid absorbent core or a liquid absorbent core fixed using a water-soluble polymer. Therefore, it is possible to significantly reduce the manufacturing cost of the liquid absorbent core.

Tar and pitch are classified according to the type of their raw materials, and raw materials include coal, wood, petroleum, and the like. However, the tar and pitch used for liquid absorbent cores are easy to handle during molding, grades with various properties are commercialized, and they are easy to obtain and stable in quality. It is most preferable to use coal as a raw material because it is inexpensive, but it is not limited in nature.

Various inorganic powders and/or organic powders can be used as the base material of the liquid absorbent core, such as clay, talc, kaolin, diatomaceous earth, gypsum, perlite, bentonite, acid clay, volcanic rock, glass fiber, rock wool,
Can you give examples of Seviolite, clay, coke, graphite, wood flour, cellulose, valves, linters, polymer resins, etc.?
Naturally, it is not limited to these. Among these, diatomaceous earth, sepiolite, wood flour, cellulose, bulb, and linter are useful in ensuring the porosity and liquid absorbency necessary for the liquid absorbent core.

The liquid-absorbent core of the present invention is produced by adding and mixing at least one of the above-mentioned binders and, if necessary, additives described below to one or more of the above-mentioned base powders, and then molding the mixture by an appropriate method.
It can be manufactured by firing. The blending ratio of the binder to the base material powder can be appropriately selected depending on the desired porosity, liquid absorption rate, etc. of the resulting liquid absorbent core, but in general, in order to impart sufficient strength to the liquid absorbent core, Powder:
The blending ratio (weight ratio) of the binder is 100:1 to 80,
Preferably it is limited to a range of 100 to 60.

On the other hand, the firing temperature can be set arbitrarily within a range that allows the production of a liquid absorbent core, but in order to ensure the necessary properties as a liquid absorbent core, it is preferable to maintain the temperature at 450 to 1300°C on the core surface.

In other words, if the firing temperature is less than 450°C, sufficient strength cannot be obtained, whereas if the firing temperature is higher than 1300°C, the carbonization of the binder or base material is significantly accelerated, and the binder exhibits an adsorption ability similar to activated carbon. This is not preferable because it hinders the evaporation of the chemical solution.

The firing time is also arbitrary, but considering ensuring the strength required for the liquid absorbent core, evaporation of chemicals, etc., and maintaining good manufacturing efficiency, the firing time should be 10 to 2 hours.
The duration is preferably 40 hours, preferably in the range of 40 to 150 hours, but is not particularly limited in nature.

In addition, the porous liquid-absorbent core may contain pigments, dyes, preservatives, other fixing agents, antioxidants, water and oil resistance improvers, flame retardants, sulfur, Other additives such as strength improvers such as zinc chloride may also be included.

Examples of antioxidants that can be added include the following. Namely, stearyl-β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2.
2'-methylene-bis(4-methyl-6-t-butylphenol), 2.2'-methylene-bis(4-ethyl-6-t-butylphenol), 4.4'-methylene-bis(4-methyl -6-t-butylphenol)
, 4.4'-methylene-bis(2゜6-di-t-butylphenol), 4.4'-butylidene-bis(3-methyl-6-t-butylphenol), 4.4'-thiobis(3-methyl -6-t-butylphenol), 1.3
゜5-trimethyl-2,4,6-1lis(3,5-di-
t-butyl-4-hydroquinebenzyl)benzene, 1,
1.3-tris-(2-methyl-5-t-butyl-4-
hydroxyphenyl)butane, tetrakis[methylene(
3,5-di-t-butyl-4-hydroxyhydrocinnamate)] methane, BHT, BHA, 3,5-di-t-
Butyl-4-hydroxyanisole, mercaptobenzimidazole, dilauryl-thio-di-propionate, 2-t-butyl-4-methoxyphenol, 3-t-
Butyl-4-methoxyphenol, 2,6-di-t-butyl-4-ethylphenol, α-tocopherol, ascorbic acid, erythorbic acid, 1,1-bis(4-hydroxyphenyl)cyclohexane, octadecyl-3
, 5-di-t-butyl-4-hydroxyhydrocinnamate, phenyl-β-naphthylamine, N,N-diphenyl-p-fuynylenediamine, 2,2.4-1 limeryl-1,2-dihydroquinoline Polymer, 6-nitoxy-2.2.4-)dimethyl-1,2-dihydroquinoline, 2.2-thiobis(4-methyl-6-t-butylphenol), 3.5-di-t-butyl-4- Hydroxy-penzyl phosphonate diethyl ester, bis(
Calcium (ethyl 5-di-t-butyl-4-hydroxybenzylphosphonate): polyethylene wax, octylated diphenylamine, tris[2-(3',5
'-di-t-butyl-4'-hydroxyhydro-cinnamoyloxyl)ethyl]isocyanurate, tris-(4-t-butyl-2,6-dimethyl-3-hydroxybenzyl)isocyanurate, 3,9-bis [1,1
-di-methyl-2-(β-(3-t-butyl-4-hydroxy-5-methyl-phenyl)propionyloxy)
ethyl]-2,4゜8.10-Tetraobeef
, 5] undecane, ditridecyl-3,3'-thiodipropionate, cimiristyl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, triethylene glycol-bisE3-C3 -t
-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanethiol bis[3-
(3゜5-di-t-butyl-4-hydroxyphenyl)
propionate], N,N'-hexamethylenebis(3,5-di-t-butyl-4-hydroxy-hydrocinnamamide), 2,2-thio-diethylenebis[3-(
3,5-dyl-t-butyl-4-hydroxyphenyl)propionate], N,N'-bis[3-(3,5-di-
t-Butyl-4-hydroxyphenyl)propionylcohydrazine, tris-(3,5-di-t-butyl-4-
hydroxybenzyl)-isocyanurate and 2.4-
Bis-(n-octylthio)-6-(4-hydroxy-
Examples include compounds such as 3,5-di-t-butylanilino-1,3,5-triazine.

These compounds can be used alone or in combination of two or more. Further, the addition method may be to add it to the obtained liquid absorbent core or add it to the drug solution, or it is arbitrary. When added to the liquid absorbent core, the amount used is 0.01 to 3% by weight, preferably 0.03 to 1% by weight, based on the amount of the core metal. When added to a drug solution, the amount is 0.0015 to 0.4% by weight, preferably 0.004 to 0.2% by weight, based on the total amount of the drug solution.

Addition of these antioxidants provides effects such as prevention of thermal deterioration during heating use, prevention of drug decomposition and polymerization, and improvement of long-term red-time stability.

In addition, dilaurylthiodipropionate (DLTP) and distearylthiodipropionate-1-(DSTP) are used in combination with the above antioxidants as antioxidants that are generally called peroxide decomposers. You can also.

Furthermore, by using an ultraviolet absorber as a stabilizer, the light resistance during storage and use can be further improved.

The molded liquid-absorbent core of the present invention is microporous and absorbs much less chemical liquid than a liquid-absorbent core mainly made of fibrous material, so it can be used for a long period of time. It is appropriate as In particular, by setting the porosity in such a porous liquid-absorbing core to 20 to 50%, preferably 25 to 45%, it is possible to both reduce liquid leakage and achieve stable evaporation of the chemical over a long period of time.

That is, as mentioned above, liquid leakage can be classified into one due to the flow of liquid inside the liquid absorbent wick and one due to the gap between the liquid absorbent wick and the container.
By setting it to 5% or less, it is possible to suppress the flow of excessive liquid inside the liquid absorbent core, and it is possible to reduce liquid leakage. In addition, in order to ensure stable transpiration of chemical liquid over a long period of time as a liquid absorbent core used in a heating evaporation device, it is necessary to
% or more, preferably 25% or more is required.

Note that the porosity is measured and calculated as follows.

After placing the liquid absorbent wick in a desiccator and making it almost vacuum, put an aliphatic saturated hydrocarbon into the desiccator and immerse the liquid absorbent wick in it to bring it to atmospheric pressure, and calculate the weight increase of the liquid absorbent wick at this time. is measured, and the porosity is calculated using the following formula.

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

An example of a device suitable for using the liquid absorbent wick of the present invention is shown in the drawings. In the figure, 1 is a container containing a chemical solution 2;
is detachably stored and held in the storage container 3. The upper part of the storage container 3 is open, and a ring-shaped (
Alternatively, a pair of semi-annular heating elements 4 are fixedly attached.

5 is a cord connected to the heating element 4. A chemical solution inlet 6 is provided at the top of the container 1.
A liquid absorbent wick 7 is held such that its upper portion is disposed at the center of the annular heating element 4. What is illustrated is an example of a device suitable 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.

The chemical liquid stored in the container 1 may contain active ingredients such as insecticides, mothballs, repellents, fungicides, bactericides, deodorants, aromatics, etc., in a suitable solvent, such as aliphatic carbonization, depending on the purpose. A solution dissolved in hydrogen or the like is used. When the above device is used as a heating evaporation insecticide, an insecticidal liquid is put into the container 1, and the heating element 4 is energized so that the surface temperature of the liquid-absorbing core 7 is preferably 100 to 130, depending on the type of insecticide. Heat to ℃. If the heating temperature is too high, there is a problem that the drug is likely to thermally decompose or polymerize, resulting in a low amount of evaporated active ingredients, and as a result, high-boiling substances, etc., will accumulate in the liquid absorption core and the core will be damaged by this. This is not preferable because it tends to cause clogging.

As the above-mentioned insecticidal liquid, solutions of various insecticides dissolved in aliphatic hydrocarbon solvents can be used, but unsaturated aliphatic hydrocarbons alone are undesirable because of their unpleasant odor, and aliphatic saturated hydrocarbons are preferable. Optimal. However, the aliphatic unsaturated hydrocarbon may be contained in a quantitative proportion that does not cause the above-mentioned disadvantages. Also, among aliphatic saturated hydrocarbons, those with carbon numbers of 19 or more have high viscosity or are in a gel-like or solidified state, making it impossible for the insecticidal liquid to absorb smoothly into the liquid-absorbing core. , it is necessary that the number of carbon atoms is 18 or less. On the other hand, since the total effective transpiration rate of insecticidal components tends to decrease as the number of carbon atoms decreases, the number of carbon atoms needs to be 12 or more in order to obtain a sufficient transpiration rate. however,
There is no problem in blending aliphatic hydrocarbons outside the above range as long as the quantitative proportion does not cause the above-mentioned disadvantages.

Aliphatic saturated hydrocarbons that can be used in the present invention include dodecane (CI2), lysocane (CI3), tetradecane (CI4), pentadecane (CI5), hexadecane (C16), heptadecane (C17), octadecane (C+a) and Commercially available solvents containing these as main components, such as No. 0 Solvent H
(manufactured by Nippon Oil Co., Ltd.), No. O Solvent M (manufactured by Nippon Ishiura Co., Ltd.), normal paraffin (manufactured by Tamaishi/Texaco Chemical Co., Ltd.), IP Solvent 2028 (manufactured by Idemitsu Petrochemical Co., Ltd.), etc. can also be used. .

As the insecticide used in the present invention, various conventionally used transpirable insecticides can be used, including pyrethroid insecticides, carbamate insecticides, organophosphorus insecticides, and the like. Generally, pyrethroid insecticides are preferably used because they are highly safe, and examples include the following insecticides.

・3-allyl-2-methylcyclopent-2-ene-4
-on-1-yl dB-cis/trans-chrysanthemate (generic name allethrin).

Product name: Pinamine (manufactured by Sumitomo Chemical Co., Ltd.)・3-allyl-2-methylcyclopent-2-nin-4-one-1
-yl d-cis/trans-chrysanthemate (generic name dfi, d-T2O-allethrin; trade name Pinamine Forte; manufactured by Sumitomo Chemical Co., Ltd.) ・d-3-allyl-2-methylcyclopenta-2- En-4-one-1-yl d-1 lansu chrysanthemate (generic name: d, d-T2O-allethrin; trade name: Exrin: manufactured by Sumitomo Chemical Co., Ltd.) ・3-allyl-2-methylcycloventer 2 ~en-4
-on-1-yl d-trans-chrysanthemate (
Product name Bioallethrin)・2-methyl-4-oxo-
N-(
3,4,5,6-titrahydrophthalimido)-methyl
dj7-cis/trans-chrysanthemate (generic name: phthalthrin; trade name: neopinamine; manufactured by Sumitomo Chemical Co., Ltd.) φ5-benzyl-3-furylmethyl d-cis/
Trans-chrysanthemate (generic name: d-T2O-resmethrin; trade name: Crysuronforte; manufactured by Sumitomo Chemical Co., Ltd.) ・5-(2-propynyl)-3-furylmethyl d-cis/trans-chrysanthemate ( -Ship name d-T80-
Framethrin: trade name Pinamine-D forte) ・3-phenoxybenzyl-2,2-dimethyl-3-(
2',2'-dichloro)vinylcyclopropane carboxylate (-ship name Vermethrin: trade name Exmin: Sumitomo Chemical Co., Ltd. % formula %) chrysanthemate (-ship name Fetutrin: trade name Sumitrin: Sumitomo Chemical Co., Ltd. )・α-cyanophenoxybenzyl isopropyl-4-chlorophenylacetate (-Ship name: Fuenvalerate: Trade name: Sumicidine: manufactured by Sumitomo Chemical Co., Ltd.)・(S)-α-cyano-3-phenoxybenzyl (I
R, cis)-3-(2,2-dichlorovinyl)2.2-
Dimethylcyclopropanecarboxylate (R,S)-α-cyano-3-phenoquinbenzyl (IR,l5)-cis/trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxy Rate (-ship name Cypermethrin) ・α-cyano-3-phenoxybenzyl d-cis/trans-crisanthemate (-ship name Cyphenotrin: trade name Gokylate) ・1-ethynyl-2-methyl-2-pentenyl cis/
Transcucli Santemato (-Ship name Emventrine:
(Product name: Hehathlin)・3-allyl-2-methyl-cyclobenter-2-en-4-one-1-yl-2,2,
3゜3-Tetramethylcyclopropanecarboxylate (generic name Terrarethrin) ・2-(para-ethoxyphenyl)-2-methylpropyl-3-phenoxybenzyl ether (-Funameko Tofuenbrox) el-ethynyl-2-methyl -2-pentenyl-2,2
,3,3-tetramethylcyclopropanecarboxylate 1-ethynyl-2-methyl-2-pentenyl-2,2
-dimethyl-3-(2,2-dichlorovinyl)cyclopropane-1-carboxylate 2,3.4,5.6-bentafluorobenzyl-3-
(2,2-Dichlorovinyl)-2゜2-dimethylcyclopropanecarboxylate The concentration of the effective insecticidal component in the insecticidal liquid is preferably 0.5% by weight or more and 5% by weight or less, preferably 0.5% by weight or more and 5% by weight or less. It is used at concentrations ranging from 5 to 3% by weight. Taking mosquito killer as an example, Pinamin Forte has 1.5■
/hr or more, bioallethrin at 1.2mg/hr or more, equisrin at 0.6mg/hr or more, and etotsuku at 0.3-g/hr or more to exhibit sufficient mosquito-killing effect. Therefore, it is preferable to use ETOTSUKU as the insecticide since a sufficient mosquito-killing effect can be achieved using a low-concentration insecticidal liquid.

Similarly, when used for aroma purposes, various natural and artificial fragrances can be used, such as animal and vegetable natural fragrances, hydrocarbons, alcohols, phenols, aldehydes, ketones, lactones, oxides, etc. , esters, and other artificial fragrances, which can be used alone or in combination of two or more. For example, limonene etc. to aliphatic hydrocarbon 0.5~l,
When dissolved at Qwt/wt%, it was confirmed that when heated to 100 to 130°C using the porous liquid-absorbing core of the present invention, it stably emits a moderate fragrance over a predetermined period from the initial stage of heating until the aromatic liquid disappears. are doing.

Furthermore, depending on the purpose, various chemicals such as deodorants, bactericidal agents, and repellents can be used as long as they evaporate by heating. The concentration of these various drugs is 0.5 to 1.
0% by weight is preferred.

Incidentally, a masking agent such as a fragrance can also be blended into the above-mentioned chemical solution.

〔Example〕

The present invention will be specifically described below with reference to Examples.

Examples 1 to 12 The components of the formulation shown in Table 1 below were mixed, extruded, and then fired so that the surface temperature of the core was 800°C. Sample No. 1-800.2-800... ...11
-800.12-800 (the numbers 1 to 12 are the example numbers, and 800 is the firing temperature. The same applies hereinafter).

Hereinafter, unless otherwise specified, the firing temperature is assumed to be at the core surface.

In addition, for Examples 1, 3, and 6, the firing temperature was 300
Sample No.

1-300...1-1500.3-300...
...3-1500.6-300...6-1
500 samples of 15 types were also created.

For all samples, the size of the liquid absorbent core is approximately 7+1I11. The length was 70 dragons.

Table 1 (Parts by weight) Comparative Examples 1 to 6 The ingredients of the formulation shown in Table 2 below were mixed with water or hot water, extruded, and then dried to form a mold with a diameter of 7 mrss and a length of 7.
A liquid absorbent core with a size of 0 m+i was manufactured.

Table-2 Clay 45 45 45 35 77 77 Diatom ± 17 17 10 40 20 20 Test Example 1 [Strength at high humidity] 24 hours or more, 25°C, 75% R, H, and 25°C, 9
The strength of the liquid absorbent core left in an environment of 0% R and H was measured by the following method.

Support 1 cIn each on a flat plate from both ends of the liquid absorbent wick, place a round bar with a diameter of 1 cm and a length of 30 mm perpendicular to the core at the center of the wick, and apply pressure from the top of the round bar to measure the strength just before the wick breaks. was measured. The results are shown in Table-3.

Table 3, Core strength [Unit: kgF] As is clear from the results shown in Table 3 above, the core produced by firing as in the example of the present invention has a strength of 75% at 25°C.
The strengths at R, H, and 25°C, 90% R, H are almost the same, whereas the cores molded using water-soluble polymers such as CMC and starch as in Comparative Examples 2 and 3 have It can be seen that high humidity causes significant strength deterioration.

In addition, sample No. 1-3GO, 6-300 of the example
For example, if the firing temperature is 300℃, the strength is 25℃.
It can be seen that , 75% R, H, 25°C, and 90% R, H are all low. On the other hand, it can be seen that the core produced by firing at a temperature of 450° C. or higher can ensure good strength without being affected by environmental humidity.

Test Example 2 [Dimensional Stability] Example Sample No. 2-800.5-800°8-
Dimensional stability was measured by taking out 100 samples of 450.8-800.8-1200 and Comparative Example 1.4, measuring their diameters, and determining the standard deviation. The results are shown in Table 4.

Table 4 As shown above, the core produced by firing as in the example has a much more stable core diameter than the core formed using a water-soluble polymer as in the comparative example. Thereby, the core manufactured by firing can reduce leakage.

Test Example 3 [Transpiration Test - Oil-Based Chemical Solution] A porous liquid-absorbing core was set in a heating evaporator shown in the drawing. The liquid inside the container is 50 ml of a mixed aliphatic saturated hydrocarbon solution having 14 to 17 carbon atoms containing the insecticide shown in Table 5.

Electricity was applied to the heating element to heat the upper side of the liquid absorbent wick to 120° C., and the amount of insecticide transpired per heating time was measured. The results are shown in Table-6.

The amount of transpiration and evaporated vapor were trapped for a unit time using a column packed with phosphoric acid gel at regular intervals, extracted with chloroform, concentrated, and quantitatively analyzed using a gas chromatograph.

Table-5 Table-6 (1) [Unit: mg/hr] Table-6 (2)
[Unit: Gourd g/hr] Table-6 (3) [Unit: a+g/hr Table-6 (4) [Unit: a+g/hr]
hr] As is clear from Table 6, the calcination temperature has a large effect on the transpiration of the drug, and the calcination temperature of 1300
The core produced at temperatures below 0.degree. C. exhibits stable drug evaporation over a long period of 400 hours without adding antioxidants or the like. On the other hand, a firing temperature of 1500° C. is not preferable because the amount of chemical transpiration per unit time decreases significantly.

In addition, with the core molded using a water-soluble polymer as in the comparative example, a significant decrease in drug evaporation is observed as the usage time increases.

Test Example 4 [Transpiration test - aqueous chemical solution] An aqueous solution containing the antibacterial and antifungal agents shown in Table 7 was prepared.

Table-7 Chemical solution No., ■, ■, ■ are for the purpose of improving dispersibility.
Each drug was premixed with twice the amount of polyoxyethylene nonylphenyl ether and then made into an aqueous solution.

Chemical solution ■ is used as chemical solution 2 of the heating evaporator shown in the drawing.

Using ■ and ■, example sample No. 2-8Q Q
.

6-800.8-800 and each liquid absorbent core of Comparative Examples 2 and 6 were set.

When observing the liquid absorbent wicks 72 hours after setting them, it was found that the liquid absorbent wicks of Comparative Examples 2 and 6 collapsed in the container.
It was not possible to confirm the antibacterial and antifungal effect.

On the other hand, Example sample No. 2-800.6-800
．． Since no abnormality was observed in each liquid absorbent core of No. 8-800, the following tests were further conducted.

Test Example 5 [Test to Confirm Antibacterial and Antifungal Effect] An agar medium coated with a spore suspension obtained by culturing fallen bacteria was placed in a 511 glass water tank.

A heating evaporator is placed in this glass aquarium to remove 30 CI from the agar medium.
The upper surface of the liquid-absorbing core was heated to 105° C. by energizing the heating element.

The glass tank was covered with a lid, and the cells were tightly sealed and cultured at a constant temperature of 25°C.

A control without a heating evaporator was also cultured under the same conditions. The results are shown in Table-8.

Table-8 No growth of 12 bacteria was observed.

±: Slight growth of bacteria is observed.

+, Bacterial growth is less than 1/3 of the total area.

廿: Growth of bacteria or about 1/3 to 2/3 of the total area.

+ Bacterial growth or more than 2/3 of the total area.

As is clear from the results shown in Table 8 above, the core produced by firing according to the present invention exhibits stable effects even when using an aqueous chemical solution, whereas the Cores molded using polymers cannot be used at all with aqueous chemical solutions.

〔Effect of the invention〕

As described above, the liquid absorbent core for heating evaporation of the present invention is essentially formed by molding and firing a mixture of inorganic powder and/or organic powder and a binder that can be carbonized by high-temperature firing. The following effects and benefits can be obtained.

b) By firing, the base material powder is firmly bound by the binder, resulting in excellent core strength and dimensional stability.

(1) Since the binder does not dissolve or swell with the chemical solution, and is not affected by the heating temperature during heating, there is no clogging or deterioration of the liquid absorbent wick caused by these, and the drug can be used for a long period of time. can be evaporated effectively and stably.

c) In addition, it can be used regardless of whether the chemical is oil-based or aqueous, and stable transpiration can be obtained during heating in either case.

2) Furthermore, good core strength can be maintained over a long period of time without being affected by the humidity of the surrounding environment.

f) In particular, by using tar, pitch, or a mixture thereof as a binder, good moldability can be obtained, and a liquid absorbent core of stable quality can be manufactured with good productivity and at low manufacturing cost.

f) It has excellent dimensional stability, so it can be tightly fitted into a container and prevents liquid leakage.

Other effects and advantages of the present invention will be readily apparent to those skilled in the art from the content of this specification.

[Brief explanation of the drawing]

The drawing is a longitudinal sectional view of an embodiment of an apparatus suitable for carrying out the method of the invention. 1 is a container, 2 is an insecticidal liquid, 4 is a heating element, and 7 is a liquid absorbing core.

Claims (3)

[Claims] (1) Liquid absorption used in a heating evaporation method in which a part of the liquid absorption core is immersed in a chemical liquid, the chemical liquid is absorbed into the core, and the absorbed chemical liquid is evaporated by heating the upper part of the core. A heating evaporation core, which is formed by molding and firing a mixture of an inorganic powder and/or an organic powder, along with other additives if necessary, and a binder that can be carbonized by high-temperature firing. Liquid absorbent wick for use. (2) The liquid absorbent wick for heating evaporation according to claim 1, wherein the binder is tar, pitch, or a mixture thereof. (3) The liquid-absorbing core for heating evaporation according to claim 1 or 2, wherein the core surface is fired at a firing temperature of 450 to 1300°C.