JPH11152498A - Detergent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a detergent capable of effectively sterilizing microorganisms and fungi attached to a fin or the like of a heat-exchanger while keeping the detergent activities, and maintaining the activities for a long period. SOLUTION: This detergent contains a surfactant for removing fouling, a thickener for regulating a viscosity, a low boiling point material for imparting a foamability, and a water-soluble microbicide having sterilizing activities. The detergent is packed in a spraying can with an insoluble compressed gas so as to be jetted. At least one kind of benzoisothiazolone and 2,2'- methylenebis-4-chlorophenol is preferably used as the water-soluble microbicide. The content of the microbicide is preferably within the region of 0.01-10 wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fin for a number of heat exchangers used for heating or cooling a gas such as air,
The present invention relates to a cleaning agent used for cleaning a filter or a flocked member, or an apparatus or facility having an environment in which microorganisms can easily grow.

[0002]

2. Description of the Related Art Conventionally, a pH adjuster which is an acid or an alkali, a surfactant, a solvent, or a mixture thereof has been known as a cleaning agent used for cleaning such an apparatus or equipment. .

[0003] Also, JP-A-8-157899 discloses that a surfactant, a thickener, a low-boiling compound and the like are mixed,
By foaming as an aerosol, it becomes difficult to defoam, and by increasing the holding power on the fin surface of the heat exchanger,
Disclosed are fin cleaning agents that are prevented from escaping in a short time.

[0004]

However, the above-mentioned conventional cleaning agent does not contain a component for surely disinfecting and removing microorganisms and mold attached to the fins of the heat exchanger. The result is that it allows for growth easily,
Various adverse effects could occur. That is, during and after the operation of the heat exchanger, nuts such as moisture originating from moisture in the air and dust floating in the air adhere to the fins of the heat exchanger, and survived mainly after washing. An environment suitable for growth of microorganisms and the like is formed. As a result, it is easy to become a suitable growth place for microorganisms and molds including pathogens such as Legionella bacteria, which may cause health problems, and the grown molds may clog the drain hose and discharge condensed water. There was a risk of causing trouble.

[0005] Further, the cleaning component of the conventional cleaning agent has a weak bactericidal action, and it is necessary to try sterilization using a large amount of the cleaning agent. However, since the sterilization is not the original purpose, it is impossible to sufficiently sterilize it. could not.

Further, in the conventional cleaning agent, since the measures for lengthening the contact time between the cleaning agent and the fin are insufficient, the cleaning agent flows out with insufficient sterilization effect by the cleaning, and surviving microorganisms. Etc., and the effect of the detergent could not be fully utilized.

[0007] Further, in the conventional cleaning agent, no measures have been taken to prevent the adhesion of microorganisms and the like after washing. Therefore, in addition to microorganisms and the like that have not been sterilized by washing, microorganisms and the like that newly attach and grow. Could appear.

The present invention has been made by focusing on the problems existing in the prior art as described above. It is an object of the present invention to effectively sterilize microorganisms and mold attached to, for example, fins of a heat exchanger while maintaining a cleaning effect, and to provide a cleaning agent capable of maintaining this effect for a long period of time. It is in.

[0009]

In order to achieve the above-mentioned object, a cleaning agent according to the present invention is characterized in that an aqueous solution containing a surfactant is adjusted to a predetermined viscosity with a thickener, and a low-boiling compound is used. And a water-soluble bactericide.

[0010] The cleaning agent according to claim 2 is at least one selected from the group consisting of a thiazolone-based disinfectant, a chlorophenol-based disinfectant, and a quaternary ammonium salt-based disinfectant. Contains seeds.

The cleaning agent according to claim 3 is the same as the cleaning agent according to claim 1 or 2, except that the water-soluble disinfectant is used in an amount of 0.1 to 1%.
It is contained in the range of 01 to 10% by weight.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the cleaning agent of the present invention will be described in detail. The detergent contains a surfactant for removing dirt, a thickener for adjusting the viscosity, a low-boiling compound for imparting foaming properties, and a water-soluble bactericide having a bactericidal action. These detergent components are usually filled in the spray can together with an insoluble compressed gas for increasing the internal pressure in order to be discharged from the spray can as an aerosol.

The surfactant is selected from cationic, anionic, nonionic or amphoteric water-soluble surfactants according to the purpose and application. Examples of the cationic surfactant include hexadecyltrimethylammonium chloride, alkyl (coconut) dimethylbenzylammonium chloride, tetradecyldimethylbenzylammonium chloride, octadecyldimethylbenzylammonium chloride, and polyoxyethylene octadecylamine. Examples of the anionic surfactant include sodium dodecyl sulfate, sodium lauryl alcohol sulfate, sodium dodecylbenzenesulfonate, sodium alkylmethyltaurate, sodium laurylmethyltaurate, alkyl sulfate, sodium dioctylsulfosuccinate, And sodium nonyldiphenylether sulfonate.

Examples of the nonionic surfactant include polyoxyethylene oleyl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether,
Examples thereof include polyoxyethylene alkyl ether, polyoxyethylene nonylphenol ether, and polyoxyethylene octylphenol ether. Examples of the amphoteric surfactant include dimethylalkyl (coconut) betaine.

Further, the use of sodium dodecyl sulfate or the like, which has a bactericidal effect such as a protein denaturing action and a cell membrane destruction action, and has an excellent detergency, enables more effective sterilization, which is preferable. Furthermore, soap, which is an alkali metal salt of a natural organic fatty acid, may be used because the waste liquid after washing is rapidly decomposed by naturally existing microorganisms and the like and is environmentally friendly.

As the thickener, sodium alginate,
Alginate propylene glycol ester, carboxymethyl cellulose ester, carboxymethyl cellulose
Sodium, sodium starch glycolate, sodium starch phosphate, methyl cellulose, sodium polyacrylate, cellulose ester, alginic acid, casein, guar gum, gluten, starch, poly N-vinylacetamide, etc. Used to select. As these thickeners, those having appropriate stability and dispersibility in relation to other components are used. Particularly in an alkaline solution, cellulose esters are preferred because of their excellent properties.

If the viscosity of the washing liquid is too low, the stability of the foam is deteriorated, and the foaming and dripping occur quickly, so it is desirable that the viscosity does not fall below 5 cP (centipoise).
Conversely, if it is too high, the discharge performance will be poor when aerosols are used, and various adverse effects will occur. Therefore, it is preferable to adjust the viscosity of the cleaning liquid to be 5 to 1000 cP, more preferably 5 to 300 cP.

As the foaming agent, isopentane or normal pentane, which is a low-boiling compound having a boiling point of 10 to 40 ° C., is preferably used so as to foam effectively at room temperature. , But is not particularly limited. Further, in order to further enhance the effect of the foaming agent, a foaming aid may be added to the cleaning solution as needed.

As the foaming aid, HCFC-22 is used.
(CHClF ₂ ), HCFC-123 (C ₂ HCl ₂ F
₃ ), HCFC-124 (C ₂ HClF ₄ ), HCFC
_{-142b (C 2 H 3 ClF 2} ), HFC-125 (C
₂ HF ₅ ), HFC-134a (C ₂ H ₂ F ₄ ) or HFC-152a (C ₂ H ₄ F ₂ )
A mixture of less than 4% by weight of LPG composed of butane and propane or dimethyl ether can be used.

The disinfectant is selected from water-soluble disinfectants because the detergent is hydrophilic. That is,
At least one selected from thiazolone-based, chlorophenol-based, and quaternary ammonium salt-based fungicides is preferably used. Benzoisothiazolone for thiazolones,
In the chlorophenol system, 2,2'-methylenebis-4-
For chlorophenol and quaternary ammonium salts, it is preferable to use 1-dodecyl-2-methyl-3-benzylimidazolium chloride or benzalkonium chloride.

The concentration of the bactericide may be added to the detergent in the range of 0.01 to 10% by weight. If the concentration of this bactericide is less than 0.01% by weight, the concentration is too low to exhibit a sufficient bactericidal effect. Conversely, if the content exceeds 10% by weight, the sterilizing effect is excessive, but the production cost increases by increasing the concentration. Furthermore, 0.02 to 1% by weight against general bacteria and 0.1% against mold
Addition in the range of 1 to 1% by weight is more preferable because a necessary and sufficient bactericidal effect can be obtained.

In order to further enhance the cleaning effect of the cleaning agent,
A solvent or a pH adjuster is added to the detergent as required. As a solvent, alcohols or ethers are used as an auxiliary role to surely dissolve all the detergent components and to dissolve dirt and microorganisms during washing. The type and concentration of the solvent are not particularly limited, but it is preferable to use amino alcohols such as N-methyldiethanolamine or the like after adjusting the concentration to about 20%. If a solvent such as 70% ethanol having a bactericidal effect at the same time is selected and used in addition to the above-mentioned action and has a strong dissolving effect on cell components, an even stronger bactericidal effect is obtained. preferable.

As the pH adjuster, the pH of the washing solution is adjusted by using an acid or an alkali. An inorganic acid or an inorganic alkali which can be adjusted to an optimum pH may be appropriately selected and added in an appropriate amount. At present, a 1% caustic solution is generally used as a fin cleaner for a heat exchanger, and microorganisms are easily killed under strong alkaline conditions.
It is preferable to add an inorganic alkali. Further, when sodium metasilicate is used as an inorganic alkali, the same effect as hydrophilic processing can be imparted to the surface of the fin of the heat exchanger simultaneously with the pH adjustment, and there is an advantage that the heat exchange efficiency is improved, which is more preferable. .

In order to discharge the above-mentioned detergent component from the spray can as an aerosol, it is necessary to fill the spray can with an insoluble compressed gas together with the above-mentioned detergent component to increase the internal pressure of the can. is there. As the insoluble compressed gas, it is more preferable to use an inexpensive nitrogen gas having low reactivity with other substances, but any gas having similar properties can be used as appropriate.

Next, the action of the cleaning agent will be described for the case of a fin of a heat exchanger. First, the cover covering the fins of the heat exchanger is removed. Next, the spray can is vigorously shaken up and down to uniformly mix the above-mentioned components of the cleaning agent. As a result, the foaming agent and the foaming assistant are mixed well with the aqueous solution, and the pressure of the nitrogen gas, which is an insoluble compressed gas, increases in the spray can, so that the gas is easily discharged. In this state, the cleaning agent is sprayed toward the fins. When the cleaning agent is discharged, the cleaning agent component and the nitrogen gas are simultaneously discharged from the spray can to the outside. Since the cleaning liquid immediately after the discharge is in the form of a mist composed of liquid droplets, the cleaning liquid easily enters the gap between the fins of the heat exchanger and reaches the interior. Thereafter, the foaming agent and the foaming aid foam and the volume expands, so that the cleaning liquid further penetrates deep into the fins.

When the cleaning liquid stays on the fin surface, the cleaning liquid does not easily flow out of the fin surface and is held for a long time due to the thickening effect of the thickener in addition to the effect of foaming. While the cleaning liquid is held on the fin surface, the cleaning components in the cleaning liquid remove or sterilize dirt, microorganisms, and the like attached to the fin surface. That is, the hydrophilic stain component is eluted in water and the solvent, and the lipophilic stain component and cell constituents such as microorganisms are destroyed by the surfactant and the solvent, and float in a state of being dissolved in water.

Further, due to the foaming action of the foaming agent, dirt and microorganisms existing as a lump on the fin surface are destroyed while the surface layer structure is disturbed. Then, at the same time as the dissolved dirt, microorganisms and the like are separated from the surface layer structure and lifted, the penetration of the detergent through the disturbed portion is further promoted.

At this time, the microorganisms and molds adhering to the fin surface are killed by contact with the germicide.
Microorganisms and the like are continuously removed by the action of water, a solvent, a surfactant and a foaming agent as described above. In other words, a chain reaction in which microorganisms and the like existing in the lower layer are newly exposed, come into contact with the germicide in the cleaning solution, and are killed and removed is repeated.

These chain reactions are continued until the cleaning liquid has run off the fin surface or until the components in the cleaning agent have reached molecular saturation and have completely lost their capacity. Therefore, when a sufficient amount of the cleaning liquid is used, dirt and the like adhered to the fin surface can be completely destroyed and dissolved unless the cleaning liquid flows out of the fin surface.

After washing for a sufficient time, the fins are washed with water. At this time, most of the cleaning agent and dirt retained on the fin surface are washed away, but a very small amount of the cleaning agent adhered to the fin surface remains without flowing out due to the action of the thickener. After the fins are air-dried, they are covered and used, but the remaining detergent components dissolve again due to the adhesion of water droplets to the fins during use of the heat exchanger, and although the effect is low, the cleaning and disinfection action is low. It is ready to work.
Even if dust or microorganisms floating in the air newly adhere to the fins, the dust, microorganisms or the like are removed from the fins by the above-described weak cleaning and sterilizing action.

Also, soda metasilicate remaining in a small amount on the fin surface as a pH adjuster covers the fin surface and imparts hydrophilicity to the fin. As a result, water droplets attached to the fins are more likely to fall. Then, during and after use of the heat exchanger, water droplets adhering to the fin surface flow out, and at the same time dust or microorganisms newly adhering are quickly eliminated. In addition, the fin surface dries quickly. Further, an increase in the drainage capacity of the fin surface leads to an improvement in heat exchange efficiency.

The effects exerted by the above embodiment will be described below. According to the cleaning agent of the embodiment, the water-soluble bactericide makes it possible to surely sterilize microorganisms and molds attached to the fins, and the microorganisms and the like do not survive after the washing is completed, and especially logarithmic growth. It is possible to prevent the rapid resumption of the growth of microorganisms and the like in the early stage. According to the cleaning agent of the embodiment, the fin surface can be surely sterilized by the water-soluble germicide, and health damage by pathogenic bacteria including Legionella can be prevented. According to the cleaning agent of the embodiment, the fin surface can be surely cleaned and sterilized by the water-soluble germicide, and the possibility that the allergen substance or microorganisms are scattered in the room can be reduced. According to the cleaning agent of the embodiment, the fin surface can be reliably cleaned and sterilized by the water-soluble germicide, and dirt or microorganisms attached to the fin are scattered into the room, and circulated and re-emitted. The possibility of sticking to the fins is reduced. According to the cleaning agent of the embodiment, the fin surface can be surely sterilized by the water-soluble germicide, and it is possible to prevent the drain hose from clogging due to the transfer of the grown mold. According to the cleaning agent of the embodiment, the contact time between the cleaning liquid and the fin surface can be lengthened by the thickening effect of the thickening agent, and the cleaning effect and the disinfection effect of the cleaning agent can be effectively exhibited. . According to the cleaning agent of the embodiment, a higher effect can be obtained with a small amount of cleaning liquid for cleaning and sterilization due to the thickening effect of the thickener. According to the cleaning agent of the embodiment, the trace amount of the cleaning agent remaining by the thickener removes dirt or microorganisms newly attached to the fin after cleaning, so that the fin surface is kept clean even after cleaning. Can be maintained. According to the cleaning agent of the embodiment, the foaming action of the foaming agent disturbs a lump structure or colony formed by dirt or microorganisms on the fin surface, thereby enabling more effective cleaning and sterilization. According to the cleaning agent of the embodiment, by adding an inorganic alkali as a pH adjuster to increase the pH, it is possible to wash in an environment where microorganisms and the like are more easily killed. According to the cleaning agent of the embodiment, the sodium metasilicate is p
By using it as an H adjuster, dirt or microorganisms can be quickly discharged together with water droplets adhering to the fin surface after washing, and the fin surface can be kept clean and the contact time between microorganisms and moisture can be reduced. . Further, the efficiency of heat exchange through the fin surface can be increased and maintained at a high level.

[0033]

EXAMPLES Examples and comparative examples which embody the above embodiment will be described below. In each of the following examples,
% Means percent by weight. (Examples 1 to 6 and Comparative Example 1) 1.5% sodium metasilicate
Benzisothiazolone or 2,2 ′ in an aqueous solution containing 8.2% sodium nonyldiphenylether sulfonate and 20% N-methyldiethanolamine and having a cellulose ester dissolved so as to have a viscosity of 12 cP.
A test solution was prepared by adding -methylenebis-4-chlorophenol to the concentration shown in Table 1. Add bacteria collected from the soil to the test solution and incubate for 15 minutes.
After culturing, the seeds were bred on an agar medium and cultured at 37 ° C. for 24 hours. All tests except culturing were performed at 20 ° C.

As criteria for evaluating the bactericidal effect, a circle indicates that colonies formed by soil bacteria were not observed on the agar medium after culturing for 24 hours, and a cross indicates that colonies were confirmed. Table 1 shows the results. (Examples 7 to 12 and Comparative Example 2) The same operation as in Examples 1 to 6 and Comparative Example 1 was performed except that mold was used instead of soil bacteria. In the judgment of the grown mold, the mycelium of the mold was confirmed instead of the colony. Table 2 shows the results.

[0035]

[Table 1]

[0036]

[Table 2] From the results for soil bacteria in Table 1, soil bacteria were completely killed at a concentration of 0.01% or more for benzoisothiazolone and 0.02% or more for 2,2'-methylenebis-4-chlorophenol. I understood that. Also, from the results for the molds in Table 2, the fungi were completely killed at a concentration of 0.02% or more for benzoisothiazolone and 0.1% or more for 2,2'-methylenebis-4-chlorophenol. I was able to.

That is, in the detergent having the composition described in this embodiment, the content of benzoisothiazolone is 0.02% or more, and the content of 2,2'-methylenebis-4-chlorophenol is 0.1% or more. By adding at a concentration, a sufficient bactericidal effect against microorganisms and fungi could be exhibited. (Examples 13 and 14) 1.5% sodium metasilicate, 5
A test solution was prepared by adding 0.2% benzoisothiazolone to an aqueous solution containing 0.1% sodium nonyldiphenylether sulfonate and a cellulose ester dissolved so as to have a viscosity of 12 cP. Further, the test solution was filled in a spray can by adding 5% isopentane, 0.5% LPG and nitrogen gas at 35 ° C. to a pressure of 7 kg / cm ² at 35 ° C. It sprayed on each of pure aluminum (henceforth pure aluminum) and a hydrophilic fin. After leaving it for 15 minutes, it was sprayed with water and washed with water, and then attached to a heat exchanger and operated continuously for 3 days.

Then, the air-contact surface of the fin was placed on an agar medium for general bacteria or mold as it was, incubated at 30 ° C. for 3 days, and the agar medium without the fin was further cultured for 2 days. Here, the hydrophilic fins are aluminum fins coated with a hydrophilic resin and represent those currently used in heat exchangers. Also, a hydrophilic resin
Unfinished aluminum fins are simply referred to as pure aluminum. The bactericidal effect was evaluated in the same manner as in Examples 1 to 6 and Comparative Example 1. Table 3 shows the results. (Comparative Examples 3 and 4) The same operation as in Examples 13 and 14 was carried out without adding benzoisothiazolone as a bactericide. Table 3 shows the results.

[0039]

[Table 3] From the results shown in Table 3, it was proved that by washing both the pure aluminum and the hydrophilic fin with a detergent containing a bactericide, even if microorganisms and mold newly adhered, they were immediately eliminated. It has also been shown here that this effect is not lost immediately and is maintained for some time. (Example 15) Among aluminum fins coated with a hydrophilic resin and currently used in heat exchangers, the fins whose hydrophilicity was reduced due to deterioration (hereinafter referred to as deteriorated fins) were used. The same detergent used in Examples 13 and 14 was sprayed, left for 15 minutes and washed with water. The operation of naturally drying for 1 hour, immersing in water for 2 minutes, and naturally drying for 6 minutes was repeated 500 times, and a contact angle was measured by dropping a water drop on the horizontal surface of the deteriorated fin. In addition, the contact angle of the deteriorated fin immediately before the cleaning agent treatment was measured in advance. Table 4 shows the results. (Example 16) The same operation as in Example 15 was performed except that pure aluminum was used instead of the deteriorated fin. Table 4 shows the results.

[0040]

[Table 4] From the results in Table 4, it was proved that both the deteriorated fins and the pure aluminum could significantly reduce the contact angle by the treatment with the cleaning agent, increase the wettability, and maintain a high level over a long period of time. . Further, regardless of the degree of deterioration of the hydrophilic resin coat, the hydrophilicity could be newly imparted by the detergent treatment. (Examples 17 to 19) The same cleaning agents as those used in Examples 13 and 14 were sprayed on the respective types of fins shown in Table 5, left for 15 minutes and washed with water. Then, after natural drying for 1 hour, it was immersed in running water for 1 to 4 weeks, taken out every week, and measured for a contact angle. Here, the cleaning fin is a fin cleaner which is usually used as a fin cleaner.
Refers to degraded fins sprayed three times with 30% caustic solution at 30 minute intervals. Table 5 shows the results. (Comparative Examples 5 and 6) The same operation as in Examples 17 to 19 was performed using fins that had not been subjected to a detergent treatment. Table 5 shows the results.

[0041]

[Table 5] From the results in Table 5, even for the deteriorated fins and the fins washed three times by the same method as that usually performed, the contact angle is reduced by the cleaning agent treatment as in the case of pure aluminum,
It was shown that the wettability was increased. That is, it was possible to improve the wettability of the fins, which were reduced by the deterioration and the normal cleaning treatment. In addition, this effect was maintained without significant decline even after at least 4 weeks.

The above-described embodiment can be modified as follows. -The fins, filters, or flocked members of the heat exchanger are made of a material such as a metal such as iron or stainless steel, a synthetic resin, or a ceramic.

With such a configuration, it can be used for cleaning and sterilizing various types of heat exchangers. Further, technical ideas that can be grasped from the embodiment will be described below. The cleaning agent according to any one of claims 1 to 3, which is used for a heat exchanger.

With this configuration, the dirt and microorganisms attached can be effectively washed away and sterilized by the continuous use of the heat exchanger. The cleaning agent according to any one of claims 1 to 3, which is used for at least one selected from a fin, a filter, and a flocked member of a heat exchanger.

In the case of such a configuration, by continuously using the heat exchanger, dirt, microorganisms, and the like adhering to the fins, the filter, or the flocked member can be effectively washed and removed and sterilized. The detergent according to any one of claims 1 to 3, wherein the surfactant is a soap made of an alkali metal salt of a natural organic fatty acid.

With such a configuration, the biodegradability of the waste liquid after washing is good, and environmental pollution can be prevented. -The cleaning agent according to any one of claims 1 to 3, wherein the water-soluble bactericide is at least one selected from benzoisothiazolone and 2,2'-methylenebis-4-chlorophenol.

With this configuration, a more reliable sterilizing effect can be exhibited. The cleaning agent according to claim 3, wherein the content of the water-soluble bactericide is in a range of 0.02 to 1% by weight.

With this configuration, the content of the bactericide in the detergent can be reduced within a range where the bactericidal effect can be sufficiently exhibited. The cleaning agent according to claim 1, further comprising a foaming aid.

With this configuration, the foaming effect can be further enhanced, and concomitantly the cleaning and sterilizing effects can be enhanced. The cleaning agent according to claim 1, further comprising a solvent.

With this configuration, the cleaning and sterilizing effects can be further enhanced. The cleaning agent according to claim 1, wherein the cleaning agent is adjusted to an appropriate pH by further adding a pH adjusting agent.

In such a configuration, the cleaning and disinfection effects can be further enhanced by appropriately adjusting the pH of the cleaning solution.

[0052]

As described above in detail, according to the present invention, the following effects can be obtained. According to the first aspect of the present invention, it is possible to effectively sterilize microorganisms and molds attached to, for example, fins of a heat exchanger while maintaining the cleaning effect, and to maintain the sterilizing effect for a long time.

According to the cleaning agent of the second aspect, in addition to the effect of the first aspect, the sterilizing effect can be reliably improved. According to the cleaning agent of claim 3,
In addition to the effects of the invention described in claim 1 or claim 2, a bactericidal effect can be effectively exhibited with a small content.

Claims (3)

[Claims] 1. A cleaning agent containing an aqueous solution containing a surfactant, which is adjusted to a predetermined viscosity with a thickener, foamed with a low-boiling compound, and contains a water-soluble bactericide. 2. The bactericide according to claim 1, wherein the water-soluble bactericide is at least one selected from a thiazolone-based bactericide, a chlorophenol-based bactericide, and a quaternary ammonium salt-based bactericide. Washing soap. 3. The content of the water-soluble bactericide is 0.0
The cleaning agent according to claim 1, wherein the amount is in a range of 1 to 10% by weight.