JPH0710707A - Transpiration wick made of porous ceramic, its production and chemicals transpiration method - Google Patents

Abstract

PURPOSE:To obtain a wick having high transpiration stability of chemicals with time, low activity and high stability to chemicals, stably usable for both oily and aqueous liquids, exhibiting high heat-resistance and enabling easy recycling and reuse. CONSTITUTION:This transpiration wick made of a porous ceramic material is composed of a liquid-ducking material obtained by calcining inorganic powder free from substances which are carbonized or dissipated in the form of CO gas or CO2 gas together with other gases in the calcination process in an oxidizing atmosphere. The liquid-sucking material is composed of a skeleton part made of an inorganic material (e.g. glass or ceramics) and through-holes included in the skeleton and enabling the migration of a solution to the surface of the wick, e.g. large-diameter channels included in the skeleton part and small-diameter connecting holes connecting the channels with each other and the channel with the surface of the wick. The liquid-sucking wick can be produced, e.g. by using raw material powder containing inorganic powder sinterable to form aggregates by heating to cause the formation of voids, forming the raw material powder to the wick form, drying the formed product and baking at the objective temperature, i.e., 1000-1450 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid absorption core made of porous ceramics for evaporation used in a wicking type heating evaporation device, a method for producing the same, and a method for evaporating a drug.

[0002]

[Prior art]

(1) Conventionally, as a method for heating and evaporating a drug for the purpose of insecticidal, a method using a mosquito coil or an electric mosquito mat has been popular. (2) In recent years, a method of immersing a porous absorbent core in a drug solution and heating the upper part of the core to heat and evaporate the drug (hereinafter referred to as a liquid system) is a method in which a mat or the like is replaced every time. It is receiving attention again because it does not need to be performed and the effect is stable for a long time. However, as the porous liquid absorbent core used in these liquid heating vaporizers, the felt was used as it was in the past, but in the case of felt, the problem that the liquid absorption amount is generally too large, There were problems such as the chemical liquid overflowing through the core during storage, transportation and use, and the problem that it was difficult to set the core correctly due to its flexibility.

(3) On the other hand, the liquid-absorbent core formed by fixing and molding the inorganic powder or the inorganic powder and the wood powder with the water-soluble paste material is disclosed in Japanese Examined Patent Publication Nos. 61-23163 and 59-40409.
JP, JP-A-63-244841, JP-A-63-74440, JP-A-1-296933, JP-A-2-39841, JP-A-2-174628, and JP-A-4-36137. It is shown in the publication. However, the absorbent core adhered with a water-soluble paste material has a problem that the chemical solution is often chemically decomposed due to the surface activity of the inorganic powder. There remains a problem that the absorbent core undergoes physical deterioration such as changes in shape and microstructure in the tissue and deterioration of mechanical strength due to dissolution, elution and swelling of the material.

(4) Further, Japanese Patent Laid-Open No. 3-72833 discloses an absorbent core having a structure having a porous liquid absorption / evaporation layer in the center and a holding material layer in the periphery. As a type, a liquid-absorbing core in which a central layer formed by bundling fibers is surrounded by a holding layer that allows a chemical solution to pass therethrough is illustrated. If the material used for this fiber core is water-resistant, it can be used in the above-mentioned aqueous chemicals, and the chemicals are not easily decomposed, but it is difficult to settle dimensionally due to its flexibility. However, difficulties in manufacturing are expected.

(5) Further, JP-A-4-117303 discloses a sintered core obtained by mixing and molding an inorganic powder, an organic powder and a binder and sintering the mixture at a high temperature. -20
Japanese Patent No. 0336 discloses a sintered core obtained by mixing and molding an inorganic powder and / or an organic powder and a binder to be carbonized and sintering the mixture at a high temperature.

This type of core can also be used for aqueous chemicals,
Although it has the advantage of being dimensionally stable, its structure has the following characteristics (a) to (c). (A) A microstructure of a porous body in which a porous frame (or wall) structure allows a chemical solution to pass through and evaporate from the surface by using interparticle pores such as small particles of primary particles or secondary small particles due to a sintering action as communication holes ( The so-called "unfired structure") has a specific surface area [m ² ·
g ^-1 ] is a big thing.

(B) Among the structures of the above (a), even if it has a cave having an extremely large diameter as compared with the diameter of the communicating hole, the space between the cave and between the cave and the liquid absorption core surface The wall structure between them is the "unfired" structure having the above-mentioned small particle pores (see FIG. 12 (b)). (C) In the liquid absorbent core, black tends to be preferred, and in many cases carbon particles remain in the particles in the porous tissue (see FIG. 12 (b)).

[0008]

However, any of the liquid absorbent cores having such a structure is carbonized or volatilized by CO gas, CO ₂ gas or other gas when the firing process is performed in an oxidizing atmosphere. Substances (eg natural and artificial fats and oils and their derivatives, processing, fractions, graphite, coal and their derivatives, processing, fractions, oil and their derivatives, processing, fractions, natural gas (Induction, processing, fractionation products, and animals and plants and their induction, processing, fractionation products, etc.) are formed in the raw material, so the following problems (1) to (5) occur. .

(1) Conventionally, the selection range of the physical properties of the liquid chemical (interfacial tension, viscosity, water-based or oil-based) has been narrowly limited by the material of the liquid absorbent core and the liquid absorbent function (porous microstructure). (2) Depending on the combination of drug solutions, the activity against drugs such as selective adsorption of drugs may occur. In other words, as mentioned above
The unglazed structure has a large specific surface area, and the surface activity of the raw material small particles is likely to remain, and the chemical resistance activity is likely to remain, such as residual activated carbon action.

(3) The "birefringent" structure has a problem that the mechanical strength is generally weaker than that of a dense porcelain wall structure. (4) The amount of transpiration of the drug per unit time decreases in proportion to the usage time due to long-term use. For example, a product having the use end date on the 60th day requires a concentration of a medicinal component that secures a desired medicinal effect by the transpiration amount per unit time on the 60th day. Since the large amount of transpiration before that also contains the same concentration of the medicinal component, the excessive medicinal component is always released, which is wasteful (see FIG. 13).

(5) Regeneration and firing in a general-purpose furnace operating in an air atmosphere is impossible. That is, in the above-described structure, in most cases, combustible carbon (carbide) particles are included as wall-constituting small particles, and since a general-purpose furnace that is inexpensive and easy to operate is operated in the atmosphere, In the case of re-firing in such a furnace, all the organic substances and carbides are gasified and the communicating hole diameter in the wall becomes large, making it impossible to reproduce the new liquid absorption core function.

The present invention has been made to solve the above-mentioned conventional problems, and its purpose is to achieve the following (a).
The purpose of the present invention is to provide an absorbent core having excellent properties such as (h). (A) A liquid absorbent core that can be normally used regardless of whether it is water-based or oil-based.

(B) It is possible to easily provide a wide range of liquid-absorbent cores that can respond to the physical properties of the liquid chemicals such as the interfacial tension and viscosity of various liquid chemicals and that can obtain a predetermined liquid-absorption rate. (C) A liquid-absorbent core that does not cause selective drug adsorption, decomposition, synthesis, or other drug activity with respect to various drug liquids.

(D) A liquid-wicking core which has high mechanical strength and is easy to use when assembling, transporting, and finally using the apparatus. (E) Liquid-absorbent wick that does not require treatments such as mildew proofing, antiseptic, insect repellent, and flame retardant. (F) A liquid-wicking wick capable of saving consumption of the active drug ingredient due to its excellent aging characteristics of the evaporation rate of the drug solution.

(G) A liquid-wicking core which can be easily manufactured with general-purpose raw materials and equipment. (H) A heat-resistant liquid absorbent core that can be easily recycled by anyone in a general-purpose air atmosphere furnace.

[0016]

[Means for Solving the Problems]

[1] Means for Achieving the Object (1) The invention of claim 1 is an absorbent core obtained by firing an inorganic powder, wherein the absorbent core has an inorganic skeleton and the skeleton. A communication hole surrounded by a part that allows the solution to move to the surface of the absorbent core,
The gist is a liquid absorption core made of porous ceramics for transpiration, which is characterized by comprising:

The term "inorganic powder" as used herein means natural and artificial fats and oils and their derivatives, processed and fractionated products, graphite, coal and its derivatives, processed and fractionated products, petroleum and its derivatives,
Processing, fractionation products, natural gas induction, processing, fractionation products, animals and plants and their induction, processing, fractionation products, etc., which are carbonized or CO gas or CO ₂ gas in the firing process in an oxidizing atmosphere. Substances excluding substances that volatilize with other gases.

(2) According to the invention of claim 2, in the liquid absorbent core, a glass or ceramic skeleton portion, a large-diameter hole surrounded by the skeleton portion, and formed in the skeleton portion. The porous ceramics liquid absorption core for evaporation according to claim 1, further comprising: a small-diameter communication hole that communicates between the cave holes and between the cave hole and the surface of the liquid absorption core. To do.

Here, the glass or ceramic skeleton means a skeleton (wall) as shown in FIG. 12 (a), which is a "non-fired form" as shown in FIG. 12 (b). It does not mean the skeleton part (wall part). (3) The invention of claim 3 is a method for producing a liquid absorption core made of porous ceramics for evaporation according to claim 1 or claim 2, wherein the sintered agglomerate by heating is a cause of pore formation. Raw material powder including powder is molded into a liquid-absorbent core shape, and after drying, optional (either oxidizing, neutral or reducing)
The gist is a method for producing a liquid absorption core made of porous ceramics for evaporation, which is characterized by firing in an atmosphere of 1000 to 1450 ° C. as a target temperature.

(4) The invention according to claim 4 is the method for producing the liquid absorbent core made of porous ceramics for evaporation according to claim 1 or 2, which comprises an inorganic substance containing salt powder which causes pore formation. The raw material powder is used to form an absorbent core shape, which is dried and then fired in an arbitrary (oxidizing, neutral or reducing) atmosphere at a target temperature of 650 to 1450 ° C. The gist is a method for producing a liquid absorption core made of porous ceramics for evaporation, which comprises volatilizing or leaching the salt during or after the step.

(5) The invention according to claim 5 is characterized in that the salt powder which causes the formation of pores is contained in the inorganic powder which causes the sintered agglomerates due to heating to form pores. A method for producing a liquid absorption core made of a porous ceramic for evaporation according to the above.

(6) The invention of claim 6 is the same as claim 3,
A method for producing a vaporized absorbent core made of porous ceramics for vaporization according to claim 4 or 5, wherein the main control content is a firing temperature, and the subordinate control content is a firing temperature holding time. Thus, the gist is a method for producing a liquid absorption core made of porous ceramics for evaporation, which is characterized in that the state of the holes formed in the core is adjusted.

(7) The invention of claim 7 is an inorganic pigment, wherein the raw material powder is an oxide, hydroxide or salt of a metal selected from iron, manganese, cobalt, copper, chrome, nickel or titanium. 0.5 to 10 parts by weight is mixed with 100 parts by weight of the raw material other than the pigment, according to any one of claims 3, 4, 5 and 6. A gist is a method of manufacturing a liquid absorption core made of porous ceramics for evaporation.

(8) The invention of claim 8 is a vaporization method in which a solution containing a drug is absorbed in an absorbent core and the drug is evaporated, wherein the absorbent core is one of claims 1 or 2. A chemical vaporization method is characterized in that it is a liquid absorption core made of porous ceramics for vaporization.

(9) The invention according to claim 9 is characterized in that the solution containing the drug is an aqueous solution or an oily solution. (10) The invention of claim 10 provides the drug vaporization method according to claim 8 or claim 9, characterized in that the drug is a pyrethroid. [2] Outline of the present invention (1) The liquid absorption core made of porous ceramics for evaporation of the present invention is
Sintered particles of raw material powder particles are not used,
A eutectic skeleton similar to general-purpose ceramics (impermeable wall)
Is a porous body having a communication hole (in which the solution can be moved) generated in the inside of the skeleton, and in particular, a large-diameter cave hole formed in the skeleton and the inside of the skeleton (cave holes or cave holes). And a liquid-absorbent core surface), which is a porous body formed by both holes of communication holes which are small holes (see FIG. 12A).

According to the manufacturing method of the present invention, the small particles are melted during firing to form a dense impermeable wall which is melted together with the large particles. At that time, when a small portion of the tissue is melted and aggregated and moved. Since the communication hole and the cave hole are formed, the specific surface area S also has an extremely small value (see S in Table 3 of FIG. 3).

(2) Further, the meaning of this melting and firing is that a large amount of glass is contained in the structure, and the surface of the raw material particles is melted and surrounded by the glass. Therefore,
The drug stability, combined with the item (1), provides good performance (see Table 8 in FIG. 8). (3) The hole having the cave hole and the communicating hole of the present invention has a surface opening hole diameter (communication hole diameter) larger than the surface opening hole diameter of the conventional product (see FIG. 12 (b)) of "unfired". , And the number is small (it can be indicated by the porosity at the eye diameter),
Moreover, since the inside of the communication hole of the opening has a cave with a diameter significantly larger than the diameter of the communication hole, the growth of the chemical solution migration resistance layer due to the heat evaporation residue or the change (hereinafter, abbreviated as the change) is caused. It reaches a certain value faster than the conventional product, and thereafter a stable evaporation rate is secured (see Table 9 in FIG. 9). Therefore, the waste of the medicinal component is reduced (see FIG. 13).

(4) The structure of the conventional porous body skeleton (wall) is a sintered product of small particles, which is a so-called "unfired" product having pores of small particles. Since the part (wall) is denser than that, the strength σ _b is also high (see Table 4 in FIG. 4 and FIG. 14).

Particularly, in the firing temperature range of the production method of the present invention, the target temperature t _B = 1175-1, which is a suitable example.
The mechanical strength of the absorbent core corresponding to 275 ° C is about 1.8 times higher than that of the conventional product. [3] Structural Examples and Application Examples of the Present Invention (1) The liquid absorbent core of the present invention uses various liquid chemical agents such as insecticides, bactericides, deodorants, and fragrances for the purpose of insecticide, sterilization, aroma and the like. It can be suitably used as a liquid absorption core of a vaporization device, for example, a liquid heating vaporization device for heating and dispersing a drug.

An example of an apparatus suitable for using the liquid absorbent core of the present invention is shown in FIG. In the figure, reference numeral 1 denotes a container containing a drug solution 2, and the container 1 is housed and held in a housing container 3 in a detachable manner. The upper part of the storage container 3 is open, and an annular (or a pair of semi-annular) heating element 4 is fixed to this open part. Reference numeral 5 is a power cord connected to the heating element 4. A drug solution inlet 6 is provided in the upper part of the container 1, and the upper part of the liquid absorbent core 7 in the drug solution inlet 6 is an annular heating element 4.
It is held in a substantially hermetically sealed shape so as to be arranged in the central portion of the. What is shown is an example of an apparatus suitable for using the liquid absorbent core of the present invention, but needless to say, apparatuses of various shapes can be used without being limited to this.

As the chemical liquid to be stored in the container 1, an insecticidal liquid, an aromatic liquid or the like is used depending on the purpose. When the device is used as a thermal evaporation insecticidal device, the insecticidal liquid is placed in the container 1, the heating element 4 is energized, and the surface temperature of the liquid absorbent core 7 is preferably 70 to 140 depending on the type of insecticide. Heat to ℃. If the heating temperature is too high, thermal decomposition or polymerization of the drug is likely to occur, and there is a problem that the amount of the transpiration effective component becomes low, and the accumulation of the high boiling point substance and the like generated as a result in the absorbent core, and This is likely to cause clogging of the core, which is not preferable. Further, if the heating temperature is too low, the evaporation of the active ingredient is naturally delayed, and in some cases, only the solvent is evaporated, which may hinder the evaporation of the active ingredient. Therefore, the optimum temperature is selected depending on the type of active ingredient, concentration, and volatility of the solvent.

(2) As the insecticide, a solution prepared by dissolving an insecticide in various solvents is used. As the solvent, those having a high flash point, no odor, and safe toxicology are preferable. The boiling point of the solvent used depends on the heating temperature of the absorbent core, but is preferably in the range of 150 to 350 ° C. Satisfying these conditions may include saturated aliphatic or alicyclic hydrocarbons having 12 or more carbon atoms, which are industrially available as normal paraffins, isoparaffins, or naphthene hydrocarbons. is there.

Of course, the solvent is not limited to these hydrocarbons as long as it satisfies the above conditions. For example, various nonionic surfactants, preferably polyoxyalkylene alkyl ether-based solubilizers (refer to those that can stabilize the insecticidal component in a clear state in water regardless of the presence or absence of micelle formation. In addition to the agent, water and
It also includes a solvent that is compatible with oil. ) Can be blended to eliminate the problem of flammability without using an aqueous insecticide.

(3) As the insecticide used in the present invention, various volatile insecticides conventionally used can be used, and pyrethroid insecticides, carbamate insecticides, organophosphorus insecticides and the like can be used. I can name it. Generally, a pyrethroid insecticide is preferably used because it is highly safe. For example, the insecticides shown in Table 5 of FIG. 5 and Table 6 of FIG. 6 can be adopted, and among them, the insecticides A to H are preferable in terms of their industrial availability, economic efficiency, efficacy and safety, and among them, the insecticides are particularly preferable. D
Is superior in terms of efficacy and economy.

The concentration of the effective insecticidal component in the insecticidal liquid is
A content of 0.5% by weight or more and 20% by weight or less is good. These insecticides may be used alone or in combination. In addition, if necessary, stabilizers, deodorants, synergists,
A small amount of dyes and other auxiliaries can be added to the liquid medicine.

(4) Similarly, when used for the purpose of aroma, various natural and artificial flavors can be used,
Eg natural animal and / or plant flavors, hydrocarbons,
Artificial fragrances such as alcohols, phenols, aldehydes, ketones, lactones, oxides, esters, etc. can be used alone or in a mixture of two or more. Further, depending on the purpose, various chemicals such as deodorants, bactericides, repellents, etc. can be used as long as they are vaporized by heating. The concentration of each kind of drug is preferably 0.5 to 10% by weight.

(5) The shape of the liquid absorbent core of the present invention is not limited to the rod-shaped core. The evaporation method is not limited to the heating method. Applications are not limited to insecticide, aroma and deodorant. [4] Description of a method for producing a porous ceramics liquid-wicking core for evaporation of the present invention (1) Among the methods for producing a liquid-wicking core, agglomeration nuclei (temperature) due to partial eutectic phenomenon in the tissue corresponding to the firing temperature A method for producing a eutectic agglomerate nuclei cross-linked porous ceramics formed by cross-linking between some non-deformable raw material particles and pores will be briefly described. This method has already been proposed in Japanese Patent Application Nos. 3-105947 and 4-116358.

That is, as the material components shown by the glaze formula, acidic component RO ₂ , neutral component R ₂ O ₃ , alkaline earth component RO,
The molar ratio of the alkali component R ₂ O satisfies the following formulas, or within a circle with a radius r represented by the following formula centered on the blending coordinate point (X, Y) determined by the following formula. While using, the raw material particle diameter of the neutral component R ₂ O ₃ is set to 10 to 60 [μm], and the alkaline earth metal component RO has a content ratio of the raw material particle diameter of 40 [μm] or more of 40.
Up to 70% by weight and 1.15 <θ <1.45 (where θ =
A method for producing a porous ceramic, that is, a method for producing a eutectic-aggregated nuclei-bridged porous ceramic, characterized by firing at a firing temperature t satisfying t ° C. × 10 ⁻³ ).

X = RO ₂ / (RO + R ₂ O) ... Y = R ₂ O ₃ / (RO + R ₂ O) ... Z = R ₂ O / (RO + R ₂ O) ... Z = 2.311 × 10 ⁵ xexp ( −12.28 × θ) ± exp (−3.8 × θ) ... Y ₁ <Y <Y ₂ ... However, Y ₁ = X−1.75, Y ₂ = X + 0.75 Y = −X + A (θ) However, A (θ) = 5808.75 × {1-exp (−6.7)
5 × θ)} − 5805.07 r = {A (θ + 0.05) −A (θ)} / 2 ^1/2 ... In this manufacturing method, the raw material particles of the neutral component (R ₂ O ₃ ) In addition to the diameter range, the raw material particle diameter range and the weight ratio of the alkaline earth metal component (RO), and the firing temperature t range, the ranges of the X, Y, and Z component ratios represented by the above formulas are all Is also determined by experiments, and good porous ceramics can be formed within this range. For the purpose of producing this absorbent core, the porosity (pore constitution, porosity, pore size) is controlled by determining one kind of raw material blending by the above formula, and then the porosity required by the absorbent core. The firing temperature indicating the above may be determined by an arbitrary temperature (hereinafter abbreviated as t _B ) on the lower temperature side than θ in the above equation. Also, R shown by the glaze formula
Is an oxide component that is usually used in the ceramic industry,
For example, Si, Zr, Al, Fe, Mg, Ca, N
Examples include elements such as a and K. Therefore, the acidic component RO ₂
Examples thereof include SiO ₂ and ZrO ₂ , and examples of neutral components include Al ₂ O ₃ , Fe ₂ O ₃ and alkaline earth components R.
As O, for example, CaO, MgO, and as the alkaline component, for example, Na ₂ O, K ₂ O, etc. can be used.

(2) As a method for obtaining a colored product, 100 parts by weight of the compounded product of the above (1) is used to oxidize an inorganic pigment (for example, iron, manganese, cobalt, copper, chrome, titanium, etc.). Powder, which is an appropriate mixture of a substance, a hydroxide, and a salt according to the purpose), is mixed in the raw material in an amount of 0.5 to 10 parts by weight, preferably 2 to 6 parts by weight.

(3) In the raw material composition of the above (1) and (2), oil and fat powder or liquid, synthetic resin powder or liquid, organic powder or liquid,
It is self-evident that even if carbon or hydrocarbon powder or the like is additionally compounded, it will be a porous ceramic raw material. The firing atmosphere at this time is limited by the oxygen content conditions. However, in general, it is easy to produce a weak one.

(4) When the above material is used for molding, a rod-shaped product is extruded from a die hole according to a conventional method and then cut into a predetermined length to obtain a rod-shaped liquid absorbent core molded product. (5) Except for the special case of the above item (3), the firing atmosphere is not particularly limited to the presence or absence of oxygen, and firing can be performed in various atmospheres such as an air atmosphere and a non-oxidizing atmosphere.

(6) As a function required by the liquid-wicking core, an appropriate pore size (meaning porous pore size, hereinafter the same) is required to control the liquid-absorption rate, the liquid-leakage rate, the evaporation rate, and the temporal change characteristics. It needs to be easily obtained. In the present method, if the same composition and the same firing temperature holding time are used, the porosity of the target pore diameter and porosity can be controlled only by controlling the target firing temperature (t _B ) lower than the firing temperature θ represented by the above formulas ,. A fine ceramics liquid absorbent core can be easily obtained.

(7) Firing temperature t according to the above manufacturing method
When a lower firing temperature t _B is required (for example, t _B <
1150 ° C.), an inorganic raw material mixture having a low temperature as a eutectic point,
For example, a method using glass powder and salt as raw materials, or RO
There is a method of using ceramic raw material and salt (or salts that volatilize at t _B or less, or salts that can be leached by a water bath or a special chemical after firing) with a particularly high compounding ratio of R ₂ O and R ₂ O as raw materials. Can be easily understood from the fact that it is disclosed in Japanese Patent Laid-Open No. 4-240167.

[0045]

[1] Operation relating to the method for producing the absorbent core (1) The method for producing the absorbent core according to claim 3 of the present invention utilizes the following properties and phenomena (a) to (d). .

(A) As for the firing temperature, if powders of the same component are used, the smaller the particle size, the lower the temperature at which the mutual reaction occurs. (B) The lower the content of the glaze R ₂ O ₃ component (eg, Al ₂ O ₃ ) is, the lower the eutectic point is.

(C) Glazed R ₂ O component (for example, Na ₂ O or K)
₂ O) has a very small eutectic point, and its eutectic point is significantly lowered. (D) The glaze RO component generates CO ₂ gas at a temperature much lower than the firing temperature of the ceramics (for example, CaCO ₃ and MgCO ₃ as raw materials have a dissociation pressure of 900 ° C. under 1 [atm], (540 ° C.), the outer diameter of the substance particles is hardly changed and the weight is reduced due to the formation of micropores at a low temperature close to the molecular level. After that, for example, when the temperature exceeds 1150 ° C., the agglomeration of the micropores and the eutectic action promote the agglomeration in the tissue, so that the micropores of 5 [μm] or more are initiated.

(2) Then, (a) to (1) of the above-mentioned (1)
Depending on the property and phenomenon of (d), the reaction and the change of the structure from small pores to large pores proceed as follows. (A) First, when the temperature exceeds 1150 ° C., the multi-component eutectic between the glaze-type components partially progresses among the small-sized particles (several [μm] or less) inside the tissue, and the amorphous (glass ), Viscous flow occurs, and larger particles of RO ₂ , R ₂ O ₃ ,
Aggregates into RO component particles. At this time, small holes more than a few [μm] begin to form.

(B) Next, when the firing temperature indicated by the composition is reached, eutectic fusion between the glaze-type components containing easily meltable even large-diameter particles progresses, resulting in the formation of large-diameter holes in the product. It progresses inside and on the surface. As a core mass in the coagulation field due to the amorphous substance by the final eutectic, the original shape is retained and remains until the end. Large particles of Al ₂ O ₃ component and secondary particles generated as a result of the fluidization are left. Although it is a lump, when it reaches around the firing temperature θ in the above formula, it is integrated as a skeleton (wall) of a porcelainized porous body having no original shape.

(C) As described above, since the core portion exists near the end of the firing process, the overall structure does not undergo any significant deformation or the entire structure is fluidized, and the shape during molding is 2 A porous ceramic is formed while maintaining the shape within the deformation of ˜3%. (3) The temperature of this final stage is represented by θ in the above formulas, and, but when the temperature is increased above the firing temperature indicated by the composition, the entire structure is softened and the pore diameter is reduced, finally. Make it non-porous. When the temperature is further raised, the entire structure is fluidized and becomes hot water.

(4) That is, the product manufactured by firing is
Although there is a desired final temperature θ depending on each compounding ratio, since this production method contains large-diameter particles of R ₂ O ₃ , its specific surface area is small, and therefore, the temperature of θ or less of the selected compound is less than θ. In the zone, R ₂ is involved in the eutectic field between small particles
The content ratio of O ₃ component becomes a small value, and the eutectic point is R _{2 of the} entire structure.
The temperature becomes lower than the temperature at which the O ₃ component content ratio comes.

For this reason, first, melting occurs at a temperature lower than θ in portions other than the large-diameter particles, and at that time, many small holes are formed. Next, as the temperature rises to θ, the formed body gradually becomes large-pore porosity by fusing innumerable small holes without causing a large dimensional change. (5) Even if a pigment is mixed within the range described in item (4) and item (2) of the column "Means", the item "1" in the column "Action" is described.
The basic changes described in paragraphs (1) and (2) do not change.

(6) From the above-mentioned action, the firing temperature satisfying the required function of the liquid absorbent core becomes the target temperature (t _B ° C) selected between θ and 650 ° C and above.
It is easy to understand. The manufacturing method of claim 4 is briefly described in the paragraph [4] (7) of the “means” column. [2] Action of Heating Evaporation Function Next, the rate control of the liquid absorption amount and the evaporation amount will be described. The following (1) to (4) are general theory, (5) is the operation of the conventional product, and (6) is the operation of the present method.

(1) From the Poiseuille's formula (Note 1), the formula of the capillary liquid absorption Qi after T time is derived. However, the physical properties of the chemical liquid such as the wet tension (σ · cos θ) and the viscosity η of the chemical liquid are constant because they are used for the same chemical liquid, so they are excluded.

[0055]

[Equation 1]

However, L: Liquid absorption distance (height) after T time σ · cos θ: Wetting tension η: Viscosity R: Capillary radius = do / 2 do: Capillary diameter dm: Rapid through hole diameter, determined by porosimeter method Pore diameter corresponding to median cumulative pore volume T: Absorption time Qi: Amount of influent in the absorbent core (rod) after T hours Ao: Cross-sectional area of the capillary A: Cross-sectional area of the absorbent core ( (Constant with a diameter of 7φ [mm]) ε _p : Porosity of the absorbent core From the above equation, it can be understood that Qi is proportional to the value of (ε _p · dm ^1/2 ). * Note 1: Chemical Engineering Society, Chemical Engineering Handbook, 5th revised edition, 2nd
Printing, Maruzen Co., Ltd., 1991.1.25, P246 (2) If Qi is smaller than the transpiration amount Qo, that is, if it is the minimum value (ε _p · dm ^1/2 ), Qo is liquid absorbing The porosity of the core, that is, the (ε _p · dm ^1/2 ) value, determines the rate.

(3) On the contrary, if the liquid absorption core is porous such that Qo <Qi, the driving force for the transpiration amount, that is, the heat reception, the transpiration area, the transpiration field temperature, and the transpiration field surface wind velocity will determine the rate. . (4) When the drug transfer resistance increases over time, Q at the beginning
o decreases with time. The cause of the increase in resistance to the movement of the chemical liquid is a transpiration residue or a change product (hereinafter, abbreviated as a residual product) of the chemical liquid. The properties of the residual metabolite are as follows: (a) When heated, it softens to become a liquid having a viscosity larger than the viscosity of the chemical liquid.

(B) It solidifies during cooling (when the liquid absorption core heating power source is not input). (5) Action in case of conventional product (a) Since the communication hole of the "unfired" wall in which the wall structure of the porous body is composed of the sintering of the small particles is a small particle interstitial hole, when heating, During the liquid phase of the residual metabolite, diffusion of the residual metabolite gradually progresses into the low-concentration liquid toward the center of the absorbent core (Fig. 1).
2 (b)). In the wall, the deposited thickness of the residual variation increases with time toward the center of the core.

(B) Since the high-viscosity layer increases in thickness from the outer periphery of the liquid absorbent core toward the center thereof in proportion to the accumulated evaporation amount, the diffusion coefficient D (proportional to the reciprocal of viscosity η) gradually decreases. Turn into. That is, the chemical transfer resistance increases in proportion to the cumulative evaporation amount, and the evaporation rate decreases in inverse proportion.

(C) The increase in the thickness of the residual product is
It also reduces the effective diffusion coefficient De = D · (ε _p / τ) (where ε _p is the porosity and τ is the labyrinth) in the porous body. In other words, increasing τ and decreasing ε _p are residual
It occurs due to the interaction of small particle pores in the bismuth-like wall. Therefore, De is further reduced due to the reduction of D in (b) above. (6) Operation in the case of the present invention (a) The wall structure of the porous ceramics according to the present method is dense, and in the case of having the cave holes and the communicating holes, the above-mentioned " There is a communication hole with a relatively larger diameter than the unglazed wall between the absorbent core surface and the internal cave, or between the cave and the cave. Of the communication holes near the surface, the small holes are residual compounds and the chemical solution moves. Increasing the resistance value is the same as for the "biscuit-like" wall, but of the surface opening hole diameters, the large-diameter communicating hole is the conventional "biscuit-like" shape.
Since the number is larger than that of the walls, the outflow of the chemical solution to the surface from the large-diameter communication hole having a small movement resistance becomes the main flow of the chemical solution supply to the evaporation field.

Even when depositing residual metabolites, the diameter of the opening is gradually reduced in the vicinity of the opening. However, since there is a cavern inside the opening, which is significantly larger than the communication hole, the radial center of the liquid absorbent core Even if there is a residue infiltrating into the pores, unlike a conventional product, unlike a conventional product, the development into a thick high-viscosity layer is prevented. The development of the layer that closes the opening around the opening diameter is mainly deposited on the surface of the absorbent core, and when heated, falls on the surface of the absorbent core due to gravity. That is, the growth of the chemical liquid movement resistance layer thickness stops at a certain constant thickness. The reason why the resistance thickness increases more rapidly (a phenomenon in which the evaporation rate decreases in a short period of time) than that of the conventional "birch-like" product is that it is deposited only on the surface.

Further, when the heating is stopped, the infiltration of the chemical solution into the semi-solidified or solidified portion is continuously changed in the case of "a biscuit-like" state, but in the product of this method, the discontinuous portion is the mainstream. The only continuous point is the layer portion that covers the large opening. (B) Due to the above-mentioned characteristics of the ceramic porous body produced by the present method, the present method enables a rapid increase in resistance to the movement of the chemical liquid, and a stable long-term transpiration due to a constant resistance thereafter (line segment in FIG. 13 (a)). A-C-B-F, line segment A in FIG.
Referring -C-B ₁ -F ₁ aging characteristic line). In addition, FIG.
As shown in (a), the characteristic curve A-C-B- showing the product of this method.
From F, the line A-B-F shown by the conventional product requires an excessive amount of transpiration. Furthermore, the content rate of the medicinal component contained in the transpiration amount G per unit time corresponding to the end-of-use period E is:
It is the same even when the transpiration amount is larger than G. That is, FIG.
The hatched portion shown in (a) shows the amount of the product of the present method that is more advantageous than the conventional product when the usage period is the same. Further, in FIG. 13B, when the total amount of evaporation is the same as that of the conventional product, according to this method, the usage time T ₁ (= E ₁ −E)
Indicates that can be extended.

(C) The amount of transpiration can be easily increased or decreased by increasing or decreasing the area of the heat receiving and transpiration field. For example, the method of increasing / decreasing the length of the heat receiving portion of the liquid absorbent core is an easy embodiment. (D) According to Poiseuille's formula, (A · ε _p · dm ^1/2 )
Even if the value is fixed, it is obvious that the evaporation amount can be controlled to be increased or decreased by changing the physical properties such as the interfacial tension and the viscosity of the chemical liquid.

[0064]

EXAMPLES The present invention will be described below based on examples, but the present invention is not limited thereto. [1] Fabrication of liquid absorption core made of porous ceramics for evaporation (1) As for raw materials, ceramic raw materials No. 1 to 5 having the composition (% by weight) as shown in Table 1 of FIG. 1 are prepared and mixed. Then, sample Nos. A1 to A3 in Table 2 were prepared so that the X, Y, and Z molar compounding ratios and raw material particle diameters in Table 2 in FIG.

(2) As a black pigment, the product name K manufactured by Kawamura Chemical Co., Ltd. was used for 100 parts of the sample Nos. A1 to A3.
R960 (composition Fe ₂ O ₃ , MnO, CoO), or KR
350 (composition Fe ₂ O ₃ , Cr ₂ O ₃ , MnO, CoO)
Was mixed with 0.5 part, 1 part, 2 parts, 3 parts, 4 parts, 8 parts, and 16 parts, respectively.

(3) For molding, according to a conventional method, that is, after kneading the sample with water, a rod-shaped long-shaped product is extruded from the 7φ [mm] die opening hole of the exit plate of the screw type extruder, and the piano Cut with a line at a specified length of 67 to 75 [mm],
A molded product of 7φ [mm] × 67 to 75 [mm] was obtained.

(4) Next, according to a conventional method, drying was carried out so that the occurrence of drying unevenness was reduced. (5) For firing, raise the temperature in an atmosphere of zero atmosphere 3
[H] and baking temperature retention time was 4 [h], and baking was performed in a stacked state in a bowl. The firing temperature was set to 1150 to 1300 ° C., and the products by firing temperature were obtained in the 25 ° C. section. At this time,
Standard firing temperature θ = 1.35 described by the above formula
Firing at a temperature lower than (t = 1350 ° C.) is because the pore size of the porous body is different from the purpose of the liquid absorption core of the drug of this example.
This is to prevent the pore size from becoming too large. [2] Product characteristic test (1) For the liquid absorbent core manufactured by the method described above,
The porosity was investigated by the porosimeter method. Also,
The color tone was observed, and the transpiration characteristics were examined by the same experiment as the transpiration experiment described later. As a result, the sample No. A1
Among the absorbent cores produced from A3, the one made of sample No. A1 was excellent in terms of porosity and transpiration property. Further, among the liquid absorbent cores having different black pigments, those containing 4 parts were excellent in terms of color tone, porosity and transpiration property.

(2) Here, a black pigment KR350 is added to 100 parts of the product having this excellent performance, that is, sample No. A1.
Fig. 3 shows the result of the porosity test of the raw material product containing 4 parts of
Table 3 and FIG. 10 and FIG. This Table 3 and FIG.
As is clear from the above, the communication pore diameter dm corresponding to the median value based on the pore volume in the tissue increases as the firing temperature t rises, and the porosity ε _p also slightly increases as t increases. It has become a big price. Further, as shown in FIG. 11, it can be seen that the value indicating the inhalation function (ε _p · dm ^1/2 ) increases as t increases.

(3) Furthermore, the strength of this product is
It was measured by a bending strength test of 601. The results are shown in Table 4 of FIG. 4 and FIG. As shown in FIG. 14, the firing temperature t
The liquid absorbent core baked in the range of 1175 to 1275 ° C. has the strength of the product of this example, which is slightly less than twice that of the conventional product (about 1.8).
It is understood that the strength is twice as high. Also, in the impact resistance test by dropping in the state of being mounted in the container, the result was as good as the strength, and the handling convenience in practical use was significantly better than the conventional product. [3] Experiment of oil absorption (water) amount and liquid absorption speed of liquid absorbent core Next, an experiment of oil absorption (water) amount and liquid absorption speed of the liquid absorbent core of this example was conducted. For comparison, a liquid absorbent core of the following comparative example was also manufactured and the same experiment was conducted.

(1) Liquid-wicking core of the example First, a diagram in which a baking temperature was changed by using a raw material in which 4 parts of the black pigment KR350 was mixed with 100 parts of the liquid-absorbing core of the present example (Sample No. A1) The oil absorption amount, the water absorption amount, and the liquid absorption speed were measured for Examples 1 to 5) in Table 7 of Table 7. The results are also shown in Table 7.

In this example and the following comparative examples, the oil absorption amount is the weight [g] of normal paraffin absorbed per 1 mL of the liquid absorption core, and the oil absorption rate is 7% of the liquid absorption core.
The time required for the normal paraffin to reach the apex by cutting it to 0 [mm] and immersing the lower part 15 [mm] in the normal paraffin at room temperature.

Unless otherwise specified, normal paraffin refers to a fraction having 14 to 16 carbon atoms. Further, the water absorption amount and water absorption rate are measured in the same manner as described above for an aqueous solution containing 40% by weight of a solubilizing agent (diethyleneoxybutyl ether).

(2) Liquid absorbent core of Comparative Example (a) Comparative Example 1 43.0% by weight of talc powder, 30.0% by weight of raw coke powder,
A powder consisting of 6.0% by weight of wood powder, 19.0% by weight of kaolin clay and 2.0% by weight of starch was mixed well, and 30.0% by weight of water was added to this powder and kneaded. did. This was pressure-extruded with an extrusion molding machine having a 7.0 [mm] nozzle, and the obtained rod-shaped molded product was air-dried,
A conventional liquid absorbent core of Comparative Example 1 was obtained by firing at 1000 ° C.
Then, the same experiment as in Examples 1 to 5 was conducted on the liquid absorbent core. Hereinafter, the experimental method is the same.

(B) Comparative Example 2 A powder composed of 53.0% by weight of mica powder, 22.0% by weight of kaolin clay, 20.0% by weight of acrylic resin powder and 5.0% by weight of carboxymethyl cellulose was well mixed,
To this, 30.0% by weight of water based on the total amount of powder was added and kneaded. This was extruded in the same manner as in Comparative Example 1,
Firing was performed to obtain the absorbent core of Comparative Example 2.

(C) Comparative Example 3 Diatomaceous earth 50.0% by weight, wood powder 24.0% by weight, activated carbon 2
To a mixture of 4.0% by weight and 2.0% by weight of starch, 130.0% by weight of water based on the total amount of powder was added and kneaded, and the mixture was extruded and air-dried to absorb the water of Comparative Example 3. A liquid core was obtained.

(D) Comparative Example 4 Similarly, the absorbent core of Comparative Example 4 was prepared from 14.0% by weight of diatomaceous earth, 35.0% by weight of clay, 49.0% by weight of calcined gypsum and 2.0% by weight of CMC-Na. Created. The oil absorption of the liquid absorbent core was 0.30 [g / mL] and the oil absorption rate was 9 hours. still,
When the absorbent cores of Comparative Examples 3 and 4 were immersed in an aqueous insecticidal solution,
It swelled and deteriorated and could not be used.

(E) Comparative Example 5 According to the composition of Comparative Example 1, 43.0% by weight of talc powder, 30.0% by weight of raw coke powder, 6.0% by weight of wood powder, 19.0% by weight of kaolin clay. %, Starch 2.0% by weight, kneading is performed by adding 50.0% by weight of water to a large amount of the whole powder, and the mixture is extruded and then molded at 50 to 80 ° C. until the water content becomes 1% by weight or less. When it was dried with, a phenomenon that the shape of the core was broken was observed, and it was impossible as a liquid absorbent core.

As is apparent from Table 7 in FIG.
Wick 5 is to identical formulations products by large pore size dm with increasing firing temperature t _B is increased (but less increase in porosity epsilon _p proportional to oil absorption), (epsilon _p · d
It has been shown that the liquid absorption rate determined by m ^1/2 ) is also increasing, that is, the liquid rising to the top of the liquid absorbing core is short. Further, since a wide range of liquid absorption rate can be obtained by t _B , it is shown that the physical properties of the target drug solution can be widely selected according to the purpose. Furthermore, whether the target chemical liquid is oily or aqueous, the same results are shown and stable.

On the other hand, among the comparative examples, those of Comparative Examples 3 to 5 without the firing operation could not be used stably with respect to the aqueous liquid. Further, Comparative Examples 1 and 2 with the firing operation also had water resistance and oil resistance, but were inferior in chemical stability described later. Further, since the porosity depends on the volatilization residual pores of organic substances and carbides, Comparative Examples 1 and 2 drastically and continuously change the porosity by changing t _B with the same composition as in the example. It is difficult to get it done. [4] Chemical stability test of liquid absorbent cores The liquid absorbent cores of Examples 1, 2, 3, 4 and Comparative Examples 1, 2, 3, 4 were crushed, and 3 g of the obtained powder was used as insecticide K. Of 1.8
Absorbing a drug solution containing 40% by weight of normal ethylene paraffin or 40% by weight of diethyleneoxybutyl ether, the powder is sealed and stored at 130 ° C for 8 hours, and the residual rate [%] of these insecticidal active ingredients is stored. Compared. The results are shown in Table 8 of FIG.

As is clear from Table 8, both the oil-based and the water-based insecticides of this example are suitable because the residual ratio of the insecticidal active ingredient is 91% or more, which is suitable. , Both are 86% or less. [5] Evaporation test of liquid absorption wick The liquid absorption wicks of Examples 1, 2 and 4 and the liquid absorption wicks of Comparative Examples 1, 3 and 4 were set in the heating vaporizer shown in FIG. 15, and the insecticide D1. A chemical solution 45 [mL] prepared by dissolving 8% by weight of water in water containing 40% by weight of normal paraffin or diethylene oxybutyl ether was placed in a container, and the side surface of the absorbent core was heated to 120 ° C. to perform a transpiration experiment. When the chemical solution was insufficient before the predetermined heating time, only the chemical solution was newly replenished at that time.

In the transpiration test, (1) the amount of reduction of the chemical solution per hour and (2) the amount of volatilization of the insecticide per hour were examined.
In (2), a silica gel packed column was trapped at regular intervals, and the insecticide was extracted with acetone and analyzed by gas chromatography. The results are shown in Table 9 of FIG. still,
In Table 9, the value (a) in the upper part of each example is the chemical liquid evaporation amount [g
/ H], and the lower value (b) is the transpiration amount of the insecticide [mg /
h] is represented.

As is clear from Table 9, the present example is suitable because the change in the amount of reduction of the chemical solution per hour and the change in the amount of volatilized insecticide per hour are small even if the heating time is long. is there. On the other hand, in the case of the comparative example, as the heating time becomes longer, the change in the reduction amount of the chemical solution per hour and the change in the insecticide volatilization amount per time increase.

That is, as a result of the above chemical stability test and transpiration test, by using the absorbent core of the present invention, the one having a furan ring or carbon-carbon triple bond like insecticide D is a drug. Is stable in this heating evaporation method,
It was possible to obtain the effect that the amount of transpiration of the chemical liquid and the active ingredient for insecticidal activity hardly decreased with time.

[0084]

The present invention has the following effects due to the above configuration. (1) Alkali resistance, acid resistance, oil resistance, water resistance, etc. are superior to conventional products. It can be stably used for both oily and aqueous chemicals.

(2) Since the liquid absorbing function tailored to the properties of the target liquid chemical can be easily achieved only by controlling the firing temperature during the production of the liquid absorbent core, a wide range of liquid chemicals can be selected. In addition, even with the same amount of chemical liquid, it became possible to select a wide range of possible evaporation time. (3) The chemical activity is stable with a small value. In other words, with regard to porosity, the specific surface area is significantly smaller than that of the conventional product because the pore size is larger than that of the conventional product, and there is almost no expression of surface activity of the raw material particles due to the glassy porcelain in the tissue. As a result, there is almost no activity against chemicals such as the action of separating and adsorbing the drug or the action of promoting decomposition polymerization. For example, even if a compound having a furan ring or a carbon-carbon triple bond, such as insecticide D, is a drug, there is almost no decrease in the insecticidal active ingredient over time.

(4) Judging from the result of transpiration, the main use range is 1150 to 1275 ° C., but the mechanical strength is about 1.8 in comparison with the conventional “non-fired” product having the same function. It is about twice as durable. Further, the same result was obtained in the impact resistance test by dropping in the state of being mounted in the container, and the handling convenience in practical use was significantly improved.

(5) Unlike conventional products, since it is made of the same material as general-purpose porcelain products, it is unnecessary to treat it against mildew, antiseptic, insect repellent, flame retardant, etc. (6) The time-dependent change characteristics of the drug transpiration rate are excellent. That is, since a constant chemical vaporization rate can be maintained for a long period of time, the effect of a chemical such as an insecticide lasts long. Alternatively, it is possible to save consumption of the active pharmaceutical ingredient.

(7) High heat resistance. At a temperature of about 50 to 100 ° C. or lower than the firing temperature at the time of production, for example, when a simple regeneration firing is performed in an atmosphere of zero atmosphere, since there is no change in the microstructure and color tone of the porous structure, an inexpensive gas furnace or the like is used. This product has excellent recyclability so that the same product as a new product can be easily obtained. on the other hand,
The conventional sintered product is a sintered product in which a large amount of carbon particles are left in the particles of the porous wall structure, and when the re-baking at 500 to 600 ° C is performed in the atmosphere without atmosphere, the carbon particles disappear and the diameter of the communicating pores increases. However, it is impossible to obtain the same function as a new product. In addition, conventional non-sintered products often contain a large amount of organic substances instead of carbides, and many cannot even retain their shape when heated at 600 ° C.

[Brief description of drawings]

FIG. 1 is a table showing components of raw material powder as Table 1.

FIG. 2 is a diagram showing a composition of raw materials of a sample as Table 2.

FIG. 3 is a table showing the relationship between the firing temperature and the communication hole diameter as Table 3.

FIG. 4 is a table showing the relationship between firing temperature and strength as Table 4.

FIG. 5 is a diagram showing a list of insecticides as Table 5.

FIG. 6 is a diagram showing the continuation of the list of insecticides as Table 6.

FIG. 7 is a table showing the characteristics due to the porosity of the liquid absorbent core.

FIG. 8 is a diagram showing a residual ratio of drug components as Table 8.

FIG. 9 is a table showing characteristics of changes in transpiration rate with time.

FIG. 10 is a graph showing the relationship between the firing temperature and the communication pore diameter and porosity.

FIG. 11 is a graph showing the relationship between the firing temperature and the liquid absorption rate proportional value.

FIG. 12 is an explanatory diagram showing structures of a liquid absorbent core of the present invention and a conventional liquid absorbent core.

FIG. 13 is a graph showing the relationship between liquid absorption time and transpiration amount.

FIG. 14 is a graph showing the relationship between firing temperature and strength.

FIG. 15 is an explanatory view showing the structure of a container in which a liquid absorbent core is used.

[Explanation of symbols]

1 ... container 2 ... chemical solution
3 ... Storage container 4 ... Heating element 5 ... Cord
6 ... Chemical injection port 7 ... Liquid absorbent core

Claims (10)

[Claims] 1. A liquid absorbent core formed by firing an inorganic powder, wherein the liquid absorbent core has an inorganic skeleton and a communication in which the solution is movable to the surface of the liquid absorbent core surrounded by the skeleton. A porous ceramics liquid-wicking core for transpiration, comprising: 2. The liquid absorbent core has a glass or ceramic skeleton portion, a large-diameter cave hole surrounded by the skeleton portion, the cave holes formed in the skeleton portion, and the cave holes. The porous ceramic liquid absorbent core for evaporation according to claim 1, further comprising: a small-diameter communication hole that communicates the hole with the liquid absorbent core surface. 3. The method for producing a porous ceramic liquid absorbent core for evaporation according to claim 1 or 2, wherein the raw material powder contains an inorganic powder in which sintered agglomerates due to heating cause pore formation. Is used to form a liquid-absorbent core, which is then dried and then fired at a target temperature of 1000 to 1450 ° C., to produce a liquid-wicking porous ceramic liquid core for evaporation. 4. A method for producing a porous ceramic liquid absorbent core for evaporation according to claim 1 or 2, wherein an inorganic raw material powder containing a salt powder that causes pores is used, After being formed into a liquid core shape and dried, 650 to 1
A method for producing a porous ceramic liquid absorbent core for evaporation, which comprises firing at 450 ° C. as a target temperature, and volatilizing or leaching the salt during or after the production step. 5. The porous ceramics for transpiration according to claim 4, wherein the salt powder that causes pores is contained in the inorganic powder that causes the sintered agglomerates due to heating to generate pores. Method for manufacturing liquid absorbent core. 6. A method for producing a liquid absorption core made of porous ceramics for evaporation according to claim 3, wherein the main control content is a firing temperature, A method for producing a liquid absorbent core made of porous ceramics for evaporation, characterized in that the state of the pores formed in the core body is adjusted by setting the content of the barrel control as the firing temperature holding time. 7. An inorganic pigment, which is an oxide, hydroxide or salt of a metal selected from iron, manganese, cobalt, copper, chrome, nickel or titanium, is added to the raw material powder in an amount of 100% by weight of the raw material other than the pigment. 0.5 to 10 parts by weight of the liquid is mixed with the parts, and the liquid absorbent made of porous ceramics for evaporation according to any one of claims 3, 4, 5 and 6. Method for manufacturing core. 8. A solution containing a drug is absorbed into an absorbent core,
A transpiration method for evaporating a drug, wherein the wick is the wicking porous ceramics wick according to claim 1 or 2. 9. The method for evaporating a drug according to claim 8, wherein the solution containing the drug is an aqueous solution or an oily solution. 10. The drug vaporization method according to claim 8, wherein the drug is pyrethroid.