JP2019028046A - Method for monitoring microbial suppression effect of coating film - Google Patents

Abstract

To provide a method for monitoring microbial suppression effect of coating film.SOLUTION: A method for monitoring microbial suppression effect of coating film formed on an object to be coated by applying a coating agent containing a polycarboxylic acid ion complex includes a partition step S101 in which a predetermined region is partitioned from another region of the application target surface of an object to be coated before applying the coating agent; a coating step S102 in which coating agent is applied to an intended surface of application to be applied to the coating material; an organic solvent extraction step S103 in which the coating film with the coating agent is formed on an object to be coated, and then the coating film of the partition region is extracted by extraction solvent; a quantitative step S104 in which the amount of cationic fungicide in the extract obtained by the organic solvent extraction step is determined by the quantitative step.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for monitoring the effect of inhibiting microbial growth, and in particular, a coating film formed on a coating object by coating a coating agent containing a polycarboxylic acid ion complex formed from a polycarboxylic acid and a cationic bactericidal agent. The present invention relates to a method for monitoring the effect of inhibiting the growth of microorganisms.

  Conventionally, antibacterial agents, fungicides, algaecides in many fields such as textiles, plastics, ceramics, tiles, concrete, adhesives, paints and other industrial products, detergents, toiletries, disinfectants, deodorants and other daily necessities A technique for suppressing the growth of microorganisms using an antimicrobial agent such as an agent is used.

  Agents used for antimicrobial agents include inorganic agents containing silver, copper, zinc, etc., organic nitrogen, organic sulfur, organic tin, organic phosphorus, organic halogen, quaternary ammonium In addition, organic drugs containing bignado-type and thiobendazole-type components are known.

  Most of these drugs are water-soluble and are extremely effective in controlling aqueous microorganisms. However, the antimicrobial effect is required to be maintained for a certain period after application as in the case of the coating agent in the technical field of the present invention. In this case, it is necessary to make the drug insoluble or hardly soluble in water and easily remain in the application part.

  As a drug insolubilized or hardly soluble in water, for example, Patent Document 1 discloses a glutamate ion complex formed from poly-γ-glutamic acid and a cationic fungicide. In Patent Document 1, examples of cationic fungicides include halide salts such as cetylpyridinium, laurylpyridium, benzethonium, benzalkonium, chlorhexidine, polyhexapyguanidine, and these are all water-soluble salts. By forming a complex with polyglutamate ions, it becomes insoluble in water, and by dissolving and coating in an organic solvent, a water-insoluble polyglutamate ion complex coating film can be formed on the surface of the coating agent.

  A glutamate ion complex formed from poly-γ-glutamic acid and a cationic fungicide is also disclosed in Patent Document 2, and Patent Document 3 uses poly (meth) acrylic acid instead of polyglutamic acid. A complex of poly (meth) acrylic acid and quaternary ammonium ions has been disclosed.

  According to the polyglutamate ion complex of Patent Document 1, the effect of suppressing the growth of microorganisms on the surface of an object is maintained for a long period of time by forming a poorly water-soluble polyglutamate ion complex coating film on the object surface. Is possible.

JP2014-122203A JP2010-222496 JP2015-163686A

  According to the polyglutamate ion complex of Patent Document 1, although propagation of microorganisms on the surface of the object on which the coating film is formed can be suppressed over a long period of time, a long time has passed, and the cationic sterilization in the coating film After the agent has flowed out, it is no longer possible to prevent the growth of microorganisms.

  Once microorganisms have propagated, it takes time to remove the microorganisms from the surface of the object, or if the object is a device, it may cause its failure. It is important to monitor whether

  There is also a need in the field to check whether the surface of an object is covered with a polyglutamate ion complex at a concentration that can reliably suppress the growth of microorganisms.

  Here, as a method for monitoring the effect of suppressing microorganisms, it is conceivable to perform a halo test in which a stainless piece or tile piece to which the polyglutamate ion complex of Patent Document 1 is adhered is placed on a medium in which microorganisms are propagated.

  However, the surface of an object covered with a polyglutamate ion complex is not always detachable, so the above halo test cannot always be performed, and the effect of suppressing microbial growth on the surface of the object is simple and rapid. Where monitoring is desired, according to the above halo test, preparation of the medium, adjustment of the cells on the medium, confirmation of halo formation for about 24 hours, and a very long time and effort are required.

  Also in Patent Documents 2 and 3, only the halo test is suggested as a method for monitoring the microbial inhibition effect as in Patent Document 1, and the same problems as in Patent Document 1 are not solved.

  The present invention has been made in view of the above problems, and its purpose is to ensure the effect of inhibiting microbial growth of a coating film formed on a coating object coated with a coating agent containing a polycarboxylic acid ion complex. In addition, the present invention provides a method for monitoring the microbial inhibitory effect of a coating film, which can be confirmed quickly and easily.

  In order to achieve the above object, the invention described in claim 1 is a coating formed on a coating object by applying a coating agent containing a polycarboxylic acid ion complex formed from a polycarboxylic acid and a cationic bactericidal agent. A method for monitoring the effect of suppressing the growth of microorganisms in a film, wherein the predetermined region is partitioned from other regions of the coating target surface of the coating object before the coating agent containing the polycarboxylic acid ion complex is coated. And a coating step of coating the coating agent containing the polycarboxylic acid ion complex on the surface to be coated of the coating object, and a coating film formed by the coating agent containing the polycarboxylic acid ion complex on the coating object. After being formed, an organic solvent extraction step of extracting the coating film in the partition region using an organic solvent as an extraction solvent; Quantitative quantifying the amount of the cationic bactericidal agent in the resulting extract by serial organic solvent extraction step, characterized by having a.

  According to this configuration, first, even when the coating object portion on which the coating film is formed cannot be attached or detached, it is possible to monitor the effect of suppressing the growth of microorganisms in the coating film on the coating object. .

  Secondly, a predetermined region of the application target surface of the object to be applied is divided from other regions before application of the coating agent containing the polycarboxylic acid ion complex, and the application containing the polycarboxylic acid ion complex on the application planned surface Cationic contained in the coating film formed in the compartment area by applying organic solvent, extracting the coating film formed in the compartment area with an organic solvent, and quantifying the amount of cationic bactericidal agent in the extract It becomes possible to quickly and simply monitor the effect of inhibiting the growth of microorganisms in the coating film as the amount of the disinfectant.

  Preferred embodiments of the method for monitoring the effect of inhibiting microbial growth according to the present invention are as follows.

(1) The partitioning process is performed after the coating process, not before the coating process, and the partitioning from other areas of the predetermined area is marked with a mark surrounding the predetermined area on the planned application surface or the coating surface of the coating agent after the coating process. Is to do.
(2) A predetermined area is partitioned from another area by attaching a test piece that can be attached to and detached from the planned application surface.
(3) The test piece is made of the same material as the application target surface of the application object.
(4) The polycarboxylic acid is selected from the group consisting of poly-γ-glutamic acid, polyacrylic acid, polymethacrylic acid, a copolymer of methacrylic acid and acrylic acid, and a mixture of two or more thereof.
(5) The cationic fungicide is one or both of a quaternary ammonium salt and a biguanide fungicide.
(6) The organic solvent is selected from the group consisting of alcohols, ketones, esters, organic chlorines and hydrocarbons.

  According to the present invention, firstly, even if the coating object portion on which the coating film is formed cannot be attached or detached, the effect of suppressing the growth of microorganisms in the coating film on the coating object is surely performed. be able to.

  Secondly, a predetermined region of the application target surface of the object to be applied is divided from other regions before application of the coating agent containing the polycarboxylic acid ion complex, and the application containing the polycarboxylic acid ion complex on the application planned surface Cationic contained in the coating film formed in the compartment area by applying organic solvent, extracting the coating film formed in the compartment area with an organic solvent, and quantifying the amount of cationic bactericidal agent in the extract It becomes possible to quickly and simply monitor the effect of inhibiting the growth of microorganisms in the coating film as the amount of the disinfectant.

  Therefore, confirmation of the completion of the application work to obtain the prescribed microbial growth inhibitory effect, and confirmation / estimation of the re-application time required to maintain the microbial growth inhibitory effect are promptly performed at the site where the application object is installed. If the effect of inhibiting microbial growth is insufficient, it is possible to quickly take measures such as recoating the coating agent.

It is a flowchart figure for demonstrating the monitoring method of the microbial growth suppression effect of this invention. It is a figure which shows the cooling water system 2 containing the cooling tower 10 which is an example of a coating target object. It is the A section enlarged view of FIG. It is a flowchart for demonstrating the other example of the monitoring method of the microorganisms growth suppression effect of this invention.

  Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 and FIG. 1 show a method for monitoring the effect of inhibiting the growth of microorganisms in a coating film formed on a coating object by applying a coating agent containing a polycarboxylic acid ion complex formed from a polycarboxylic acid and a cationic bactericidal agent. This will be described with reference to FIG. FIG. 1 is a flow chart for explaining the method for monitoring the effect of inhibiting microbial growth of the present invention, and FIG. 2 is a perspective view showing a cooling tower which is an example of an object to be coated.

  First, the coating agent used in the present invention will be described.

<Coating agent>
The coating agent contains a polycarboxylic acid ion complex as an essential component. The polycarboxylate ion complex is a poorly water-soluble or water-insoluble substance formed by mixing a polycarboxylic acid and a cationic fungicide in a solvent or the like. In addition, slightly water-soluble (water-insoluble) means that the solubility in distilled water at 25 ° C. is less than 10 g / L, preferably less than 1 g / L.

(Polycarboxylic acid)
A polycarboxylic acid is an organic compound having two or more carboxyl groups in the molecule. The type of polycarboxylic acid used in the present invention is not particularly limited, but poly-γ-glutamic acid, polyacrylic acid and polymethacrylic acid are suitable, and a mixture of two or more of these polycarboxylic acids is used. May be. Moreover, the copolymer of acrylic acid and methacrylic acid may be sufficient.

  The molecular size of the polycarboxylic acid to be used is not particularly limited, but in the case of poly-γ-glutamic acid, the average molecular weight is preferably 10 kDa or more, and more preferably 100 kDa or more. In general, the larger the molecular size, the higher the performance such as strength. On the other hand, polycarboxylic acids having an excessively large molecular size are expensive to produce and may be technically difficult to produce. In addition, the average molecular weight of poly-γ-glutamic acid can be referred to a catalog value when a commercially available product is used in addition to a value measured by gel filtration chromatography or the like.

  When polyacrylic acid (homopolymer or copolymer of acrylic acid), polymethacrylic acid (homopolymer or copolymer of methacrylic acid), and a copolymer of acrylic acid and methacrylic acid are used as polycarboxylic acid The viscosity average molecular weight is preferably 100,000 or more and 1,000,000 or less.

  When the viscosity average molecular weight is less than 100,000, the strength of the formed ion complex becomes low, and it becomes difficult to form the ion complex alone such as heat forming. On the other hand, when the viscosity average molecular weight exceeds 1,000,000, the solubility is lost and spraying and coating (coating) cannot be performed, and the moldability (uniformity of the coating film) is deteriorated due to gelation.

  The viscosity average molecular weight is more preferably 150,000 or more, more preferably 200,000 or more, still more preferably 300,000 or more, particularly preferably 400,000 or more, more preferably 900,000 or less, 800, 000 or less is more preferred, 700,000 or less is more preferred, 600,000 or less is even more preferred, and 500,000 or less is particularly preferred.

  Viscosity average molecular weight is the average molecular weight obtained from the viscosity of the polymer. Normally, the viscosity average molecular weight of the polymer is measured by measuring the intrinsic viscosity [η] of a standard sample whose molecular weight is known and the intrinsic viscosity of the sample whose molecular weight is to be obtained. Is what you want. In this invention, it uses as a reference | standard of the molecular weight of the copolymer of polyacrylic acid, polymethacrylic acid, and the copolymer of polyacrylic acid and polymethacrylic acid.

  When any of the above polycarboxylic acids is used, a slightly water-soluble ion complex obtained after mixing with the following cationic bactericidal agent is used. The polycarboxylic acid ion complex can be produced by a known method. For example, an aqueous solution or aqueous dispersion of polycarboxylic acid is prepared, and if necessary, pretreatment such as neutralization is performed on this solution. Mixing with an aqueous cationic fungicide solution causes precipitation of a poorly soluble polycarboxylic acid ion complex. In addition, when there is a high possibility that water-soluble materials such as low-molecular carboxylic acids (water-soluble) are mixed after production, for example, the slightly water-soluble material should be separated from the aqueous dispersion by filtration or the like. You can also.

(Cationic fungicide)
The cationic fungicide used in the present invention ionically bonds with the carboxyl group of the polycarboxylic acid to form a complex. Although the kind is not specifically limited, Use of any one or both of a quaternary ammonium salt and a biguanide type fungicide is preferable.

  Examples of quaternary ammonium salts include cetylpyridinium chloride, benzethonium chloride, distearyldimethylammonium chloride, stearyldimethylbenzylammonium chloride, stearyltrimethylammonium chloride, lauryltrimethylammonium chloride, laurylpyridinium chloride, benzalkonium chloride, and dichloride chloride. Examples include decyldimethylammonium. Examples of the biguanide fungicide include chlorhexidine hydrochloride, chlorhexidine acetate, chlorhexidine gluconate, alexidine hydrochloride, alexidine acetate, and alexidine gluconate.

  Among these, cetylpyridinium chloride, benzethonium chloride, benzalkonium chloride, laurylpyridinium chloride, chlorhexidine hydrochloride, and chlorhexidine gluconate are preferable. These cationic fungicides may use only 1 type and may use 2 or more types.

(Coating agent adjustment)
As the coating agent used in the present invention, a solution in which a polycarboxylic acid ion complex is dissolved or dispersed in an organic solvent can be used.

  As the organic solvent for preparing the coating agent, one or more of the group consisting of alcohols, hydrocarbons, ketones, and esters can be used, but from the viewpoint of safety in handling and consideration for the environment, Alcohols such as methyl alcohol, ethyl alcohol and propyl alcohol are preferred, and ethyl alcohol is more preferred. Further, a mixed solution of ethyl alcohol and water may be used.

  The content concentration of the polycarboxylic acid ion complex in the coating agent is preferably 0.1 w / v% (mass / volume%) or more and 30 w / v% or less, more preferably 0.5 w / v% or more and 20 w / v% or less. preferable.

  When the content concentration of the polycarboxylic acid ion complex is less than 0.1 w / v%, it is necessary to repeat the coating / drying process until the predetermined concentration is reached, which is not preferable because the operation time becomes long. On the other hand, if it exceeds 30 w / v%, the viscosity of the coating agent becomes high and unevenness of the coating occurs, which is not preferable.

  One or more additives such as dyes, pigments, other preservatives, viscosity modifiers, coupling agents, and pH adjusters (acids, alkalis) may be added to the coating agent.

  Next, the coating agent will be described with respect to the coating agent.

(Application object)
The objects to be applied include cooling towers included in the cooling water system, which is a water-cooled cooling system, building window frames, heat exchangers for air conditioners, interior parts of hot and humid environments such as bathrooms and boiler rooms, toilets and kitchens, etc. Any equipment that requires a microbial growth-inhibiting effect, such as water, is the object to be applied.

  The material of the application object is not particularly limited, but any material used for the application object, including plastic, fiber, wood, concrete, brick, metal, metal oxide, ceramic, marble, glass, can be arbitrarily selected. You can choose.

  In the present invention, in a partitioning process to be described later, a predetermined region is partitioned from other regions in the planned application surface of the coating object. The predetermined area may be divided by attaching a test piece to the surface to be coated.

(Test pieces)
The test piece is a film, a tape, or a sheet having a predetermined area, and is formed so as to be detachable from the surface to be coated. As a material of a test piece, it selects from the raw material used for the above-mentioned application target object. Moreover, it is preferable to use the test piece of the same material as the material of the application | coating plan surface of a coating target object from a viewpoint of monitoring the microorganisms propagation suppression effect of the coating film apply | coated to the application | coating plan surface more correctly. However, it is not always necessary to use the same material, and any material can be used as long as the purpose of monitoring the effect of inhibiting the microbial growth of the coating film can be achieved.

<Monitoring method of microbial growth inhibition effect>
Next, the method for monitoring the effect of inhibiting the growth of microorganisms according to the present invention will be described by taking as an example the case where a cooling tower is used as an object to be coated.

  In the cooling tower (cooling tower), in order to evaporate the cooling water, it is brought into contact with the atmosphere. At that time, since the water scatters in the form of a mist (aerosol), not only the part that directly contacts the cooling water, The surrounding area becomes wet with cooling water.

  Microorganisms such as algae, bacteria, and fungi grow on the wetted parts (wetted parts), and slime (biofilm) is easily formed. Causes slime disorders such as obstruction. Therefore, in order to maintain the function of the cooling tower, it is important to monitor the effect of inhibiting the growth of microorganisms by the coating film.

  Here, as shown in FIG. 2, the cooling tower 10 includes a main body 11 and a blower 21 attached to the main body 11. An opening (ventilation port) is formed on the side wall of the main body 11. When the blower 21 is operated, air is discharged from the main body 11, the internal pressure is negatively inclined, and the outside air is drawn from the vent hole.

  A shielding member such as a louver 19 is installed at the vent, and rainwater, dust, and the like are blocked by the louver 19, but outside air flows into the main body 11 through a gap between the louvers 19.

  A filler 25 is disposed inside the main body 11, and the inflowing outside air passes through the filler 25 and is discharged from the blower 21 to the outside again. That is, an air flow through the filler 25 is generated inside the main body 11.

  The main body 11 is provided with watering means 30. The watering means 30 includes a watering tray 31 installed on the ceiling of the main body 11 and water supply means for supplying cooling water to the watering tray 31. Although a water supply means is not specifically limited, For example, it has the piping 33 embed | buried under the partition member 32 (watering bar) etc. of the watering tray 31, and cooling water is supplied to the watering tray 31 from this piping 33. A plurality of through holes are formed in the watering tray 31. The cooling water passes through the through holes and falls into the main body 11. The cooling water is sprinkled on the filler 25, and the cooling water passes through the filler 25. Fall.

  In the case of a cross flow type (cross flow type) cooling tower, air flows from the side wall of the main body 11 in a lateral direction, that is, substantially orthogonal to the cooling water dropping direction. On the other hand, in the case of a counterflow type (counter flow type) cooling tower, air flows from the lower part of the main body 11 to the upper part, that is, facing the falling cooling water. In either case, the cooling water comes into contact with air and at least a part of it evaporates.

  In the case of a hermetic cooling tower, piping is embedded in the filler 25. Cooling water different from the cooling water flows through the pipe, and the cooling water is cooled by heat of vaporization when the cooling water evaporates.

  On the other hand, in the case of an open type cooling tower, excessive cooling water itself that passes through the filler 25 without being evaporated becomes cooling water and is cooled by heat of vaporization during evaporation.

  In the case of an open type cooling tower, the cooling water dropped through the filler 25 is sent to the cooling device 40 (see FIG. 2) as cooling water. In the cooling device 40, the water to be cooled exchanges heat with the refrigerant, cools the refrigerant, and simultaneously heats itself to return to the cooling tower 10.

  The surface to be coated of the cooling tower 10 is not particularly limited, but microorganisms propagate in the portion wetted by the cooling water (wetted part) and slime is easily formed, so the portion wetted by the cooling water (wetted part) is applied. It is effective to use a planned surface.

  Examples of the liquid contact portion include a watering tray 31, a watering tray cover 34, a pipe 33, a filler 25, a bottom wall of the main body 11, a flow path 41, and other members (sprinkler, strainer, lower water tank, various pipes), and the like. Or a louver 19, a blower 21, a partition member 32, a main body 11 ceiling (inner wall surface and outer wall surface), a main body 11 side wall (inner side surface and outer side surface), and cooling water droplets (mist). A member with high possibility of adhering may be used.

[Partition process (S101)]
In the partitioning step (see FIG. 1), a predetermined region is partitioned from other regions in the planned coating surface of the coating object before the coating agent containing the polycarboxylic acid ion complex is coated. For example, the predetermined area can be partitioned from another area by attaching a detachable test piece to a predetermined application surface of the application object.

  FIG. 3 is an enlarged view of a part A in FIG. 2 and shows a louver 19 as a surface to be coated. The test piece 50 is attached to the louver 19 by providing adhesion, a concave portion and a convex portion corresponding to the louver 19 and the test piece, and engaging with the concave portion and the convex portion, or hanging the test piece near the louver 19. Etc. Anything may be used. In the example of FIG. 3, a mode is shown in which screw holes are respectively provided in the louver 19 and the test piece 50 and screwed with screws 52.

  Further, the predetermined area of the predetermined application surface (in this case, the louver 19) may be divided from other areas by marking the predetermined area of the louver 19. The marking is performed by surrounding a predetermined area of the louver 19 with, for example, an oil marker, a seal, a tape, or the like (partitioning step (S101)).

[Coating process (S102)]
In the coating step (see FIG. 1), a coating agent containing a polycarboxylic acid ion complex is coated on the surface to be coated of the coating object. Prior to application, it is preferable that the surface to be applied be cleaned and dried in advance by various methods including brush cleaning, high pressure cleaning, and chemical cleaning. As a coating method of the coating agent, various coating methods including a brush coating method, a roller coating method, a spray spraying method, a dipping method, a coating method, and a printing method can be selected.

The application may be performed once, or the application may be repeated. In the case of repeating the coating, it is preferable to dry after coating and fix the coating of the polycarboxylic acid ion complex on the construction part, and then perform the next coating. The number of repetitions of coating varies depending on the concentration of the coating agent used, but as a cationic bactericidal agent constituting the polycarboxylic acid ion complex, 0.05 nmol to 10 nmol per square centimeter (cm ² ) of the wetted part, The series of steps of coating, drying, and film fixing is repeated once or more so that it is preferably 0.1 nmoL or more and 5 nmoL or less, more preferably 0.15 nmoL or more and 2 nmoL or less.

  If the amount of the cationic bactericidal agent is less than 0.05 nmol, the bactericidal agent distribution in the bactericidal agent film is likely to be uneven, and the possibility that the effect of suppressing microbial growth is reduced. On the other hand, if it exceeds 10 nmol, it is not realistic due to restrictions on working time and processing cost required for fixing the coating.

  In addition, each process of application | coating, drying, and film fixation may be performed in the state which mounted | wore the cooling water system 4 (cooling tower 10) with the components (apparatus) which has a wetted part, and the components (apparatus) which has a wetted part May be performed in a state of being removed from the cooling water system (cooling tower 10) (the coating step (S103)).

[Organic solvent extraction step (S104)]
In the organic solvent extraction step (see FIG. 1), after a coating film with a coating agent containing a polycarboxylic acid ion complex is formed on the object to be coated, the coating film in the partition region is used as the extraction solvent. Extract.

  As the organic solvent used in this step, one or more members selected from the group consisting of alcohols, hydrocarbons, ketones, esters, and organic chlorines can be used as the organic solvent. In consideration of the inside, alcohols such as methyl alcohol, ethyl alcohol, and propyl alcohol are preferable, and ethyl alcohol is more preferable. Further, a mixed solution of ethyl alcohol and water may be used.

  The test piece 50 is removed from the louver 19 and subjected to organic solvent extraction.

  As the organic solvent extraction method, a dipping method in which the organic solvent is immersed in an elution development, a wiping method in which the swab or cotton cloth impregnated with the organic solvent is wiped off, and the wiped cotton swab or cotton cloth is immersed in an organic solvent to be elution developed. Etc.

  In addition, when using the wiping method, organic solvent extraction can be performed with the test piece 50 attached to the louver 19. Moreover, also when not using a test piece for a division process, organic solvent extraction by a wiping off method is performed (above, organic solvent extraction process (S104)).

[Quantitative Step (S105)]
In the determination step (see FIG. 1), the amount of the cationic bactericide in the extract obtained by the organic solvent extraction step is determined. Examples of the quantitative method of the cationic bactericidal agent include an absorptiometric method, a titration method, a liquid chromatographic method, a colorimetric method, and a simple test paper method.

  As the simple test paper, for example, a quaternary ammonium salt test paper sold by Merck Co., Ltd. can be selected. The simple test strip method is particularly preferable because it can confirm the monitoring value immediately on-site and is convenient.

  In addition, the quantity in the coating film of cationic sterilizers, such as a quaternary ammonium salt and a biguanide type | system | group fungicide, has a direct connection with the microbial growth suppression effect. Therefore, monitoring the amount of the cationic disinfectant in the coating film formed on the surface of the object is equivalent to monitoring the effect of inhibiting microbial growth by the coating film (the determination step (S105)).

  Therefore, according to the method for monitoring the microbial growth inhibitory effect of the present invention, the microbial growth inhibitory effect can be reliably monitored as the amount of the cationic bactericidal agent contained in the coating film.

  Further, according to this method, a predetermined region of the application target surface of the application object is partitioned from other regions before application of the coating agent containing the polycarboxylate ion complex, and the polycarboxylate ion complex is formed on the application target surface. The coating film is applied quickly and simply by the operation of extracting the coating film formed in the partition region with an organic solvent and quantifying the amount of the cationic bactericidal agent in the extract. It becomes possible to monitor the microbial growth inhibitory effect of the membrane.

  Further, by using the test piece 50, it is possible to extract the organic solvent by the dipping method, and therefore, it is possible to more easily determine the amount of the cationic bactericide with higher accuracy.

  In addition, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the meaning of invention. For example, in the above embodiment, the partitioning step is performed before the coating step, but is not limited thereto.

  FIG. 4 is a flowchart for explaining another example of the method for monitoring the effect of inhibiting microbial growth of the present invention. In the case where the predetermined area of the application target surface of the application object is partitioned from other areas by marking the application target surface with the mark including the predetermined area, as shown in the figure, a partitioning step (S101 ′) May be performed after the coating step (S102).

  Hereinafter, the present invention will be described more specifically with reference to examples.

[1. Monitoring the effect of inhibiting the growth of microorganisms in the coating film during the application of a coating agent containing a polycarboxylic acid ion complex]
Hereinafter, a test for confirming whether or not a coating film having a desired microbial growth inhibitory effect was formed on the coating object by applying the coating agent containing the polycarboxylic acid ion complex to the coating object was performed.

Example 1
A polycarboxylic acid ion complex (0.5 g) composed of poly-γ-glutamic acid and benzalkonium chloride was dissolved in 100 mL of a 70% ethanol aqueous solution to prepare a 0.5 (w / v%) coating agent. The poly-γ-L-glutamate ion complex was produced as follows.

  Poly-γ-L-glutamic acid sodium salt (1.0 g) having an average molecular weight of 1000 kD derived from the hyperhalophilic archaeon Natrialva Edipticia was dissolved in purified water to obtain a 2 w / v% solution. An 8 w / v% aqueous solution of benzalkonium chloride (2.4 g) kept at 60 ° C. was added to the solution. After confirming that a water-insoluble material was formed immediately after addition of benzalkonium chloride from an aqueous solution of poly-γ-L-glutamic acid sodium salt as a raw material, the mixture was further stirred at 25 ° C. for 2 hours. The obtained water-insoluble material was collected by filtration and then washed 3 times with 100 mL of purified water. It vacuum-dried and collect | recovered poly-gamma-glutamate ion complex (3.0g). From the result of 1H-NMR of the obtained poly-γ-glutamate ion complex, it was confirmed that poly-γ-L-glutamic acid and benzalkonium were bound at a molar ratio of 100: 100.

The surface to be coated of the louver 19 of the cooling tower 10 is previously cleaned with a high-pressure washing machine and dried, and then a 3 cm × 10 cm (area 30 cm ² ) polyvinyl chloride (PVC) test piece is screwed to the surface to be coated. It was divided from the other area | region of the application | coating plan surface by attaching.

Thereafter, the coating agent was applied by spraying onto the planned application surface including the test piece and other regions, and then air-dried to form a coating film on the louver 19. The target application amount (set application amount) of the coating agent was 0.25 nmol to 0.35 nmol per 1 cm ² of the surface of the louver 19 as benzalkonium chloride. If the set application amount is less than the lower limit value, the concentration of the cationic bactericidal agent is low to expect a microbial growth inhibitory effect for a predetermined period, and if it exceeds the upper limit value, there is no problem in terms of the microbial growth inhibitory effect. Set as excessive in terms.

After application, the test piece was collected and immersed in 10 mL of 99 v / v% ethyl alcohol to extract benzalkonium. The extract was made up to 10 mL with 99 v / v% ethyl alcohol, 1 mL of the extract was mixed with 9 mL of pure water, and quaternary ammonium salt test paper (MQuant (registered trademark) quaternary ammonium salt test, Merck Ltd.). Manufactured). As a result, the amount of benzalkonium in the coating film was 0.33 mol per 1 cm ² of coating film in terms of benzalkonium chloride, and it was confirmed that the coating work was performed according to the set coating amount.

(Example 2)
A polycarboxylic acid ion complex (0.5 g) composed of poly-γ-glutamic acid and cetylpyridinium chloride was dissolved in 100 mL of a 70% ethanol aqueous solution to prepare a 0.5 w / v% coating agent. The poly-γ-L-glutamate ion complex was produced as follows.

  Poly-γ-L-glutamic acid sodium salt (1.0 g) having an average molecular weight of 1000 kD derived from the hyperhalophilic archaeon Natrialva edipitiaca (1.0 g) was dissolved in purified water to obtain a 2 w / v% solution. Cetylpyridinium chloride (2.4 g) kept at 60 ° C. was added to the solution. After confirming that a water-insoluble material was formed immediately after the addition of cetylpyridinium chloride from an aqueous solution of the raw material poly-γ-L-glutamic acid sodium salt, the mixture was further kept at 60 ° C. for 4 hours. The obtained water-insoluble material was collected by filtration and then washed 3 times with 100 mL of purified water. It vacuum-dried and collect | recovered poly-gamma-L-glutamate ion complex (3.0g) as a powder. From the result of 1H-NMR of the obtained poly-γ-L-glutamate ion complex, it was confirmed that poly-γ-L-glutamic acid and cetylpyridinium were bound at a molar ratio of 100: 100.

The same procedure as in Example 1 was performed from the mounting of the test piece (compartment process) to the determination of the amount of the cationic bactericide in the coating film (quantification process). As a result, the amount of quaternary ammonium salt (cetylpyridinium chloride, cationic fungicide) in the coating film is 0.34 nmoL per 1 cm ² of coating film in terms of benzalkonium chloride, and the coating work is performed according to the set coating amount. Was confirmed.

(Examples 3-9, 12-17)
When applying polycarboxylic acid ion complex-containing coating agent in the same manner as in Example 1 except that the polycarboxylic acid ion complex, the set coating amount and the extraction solvent used in the organic solvent extraction step were changed as shown in Table 1. The effect of inhibiting the growth of microorganisms in the coating film was monitored.

(Example 10)
The coating step and the partitioning step were performed in the same manner as in Example 1 except that the polycarboxylic acid ion complex and the set coating amount were changed as shown in Table 1. It shows below about an organic-solvent extraction process and a fixed_quantity | assay process.

That is, after the coating agent was applied to the surface to be coated and the coating film was formed by air drying, the test piece was collected, immersed in 20 mL of chloroform, extracted, and then 0.1 mL of 0.1 W / W% bromophenol sodium solution in the extract Then, 20 mL of water was added, and the mixture was vigorously stirred for 1 minute or longer to extract cetylpyridinium in the chloroform layer. Next, as a result of measuring cetylpyridinium by the sodium tetraphenylborate titration method, the amount of cetylpyridinium in the coating film is 0.35 mol per 1 cm ² of coating film in terms of benzalkonium chloride, and the coating work according to the set coating amount. Was confirmed to have been implemented.

(Example 11)
The coating step and the partitioning step were performed in the same manner as in Example 1 except that the polycarboxylic acid ion complex and the set coating amount were changed as shown in Table 1. It shows below about an organic-solvent extraction process and a fixed_quantity | assay process.

That is, after application of the coating agent on the surface to be coated and formation of a coating film by air drying, the test piece was collected, immersed in 10 mL of normal hexane, extracted, and then evaporated of normal hexane, and then 20 mL of chloroform, 0.1 W / 0.1 mL of W% sodium bromophenol solution and 20 mL of water were added, and the mixture was vigorously stirred for 1 minute or more to extract cetylpyridinium in the chloroform layer. Next, as a result of measuring cetylpyridinium by the sodium tetraphenylborate titration method, the amount of cetylpyridinium in the coating film was 0.33 mol per cm ² of coating film in terms of benzalkonium chloride, and the coating operation was performed according to the set coating amount. Was confirmed to have been implemented.

  The results are shown in Table 1.

  In Table 1, the set application amount and the measured application amount of Examples 7 and 8 are the total amount of two types of cationic fungicides. The polycarboxylic acid ion complexes of Examples 3 to 8 were produced under the same conditions as in Example 1 except that the type of the cationic bactericidal agent was changed, and the polycarboxylic acid ion complexes of Examples 9 to 11 were prepared in Example 2. The polycarboxylate ion complexes of Examples 12 to 14 were prepared by changing the HDPB (hexadecylpyridinium bromide) to the substances shown in Table 1, and the method described in paragraph [0076] of JP-A-2015-163686. It is manufactured by.

  Moreover, the polycarboxylic acid ion complex of Example 15 was produced by the same method as Example 13 except that polyacrylic acid was changed to polymethacrylic acid (manufactured by Aldrich, weight average molecular weight to 9500). 16 polycarboxylic acid ion complex was changed to Example 12 except that polyacrylic acid was changed to an equimolar mixture of poly-γ-glutamic acid used in Example 1 and polyacrylic acid used in Example 12. The polycarboxylic acid ion complex of Example 17 was prepared in the same manner as the polyacrylic acid used in Example 12 and the polymethacrylic acid used in Example 15 in an equimolar amount. The product was produced in the same manner as in Example 12 except that the mixture was changed to a mixture.

  As shown in Table 1, also in Examples 3 to 17, the measured coating amount of the quaternary ammonium salt (cationic fungicide) in the coating film is within the range of the set coating amount, and the coating work according to the set coating amount. Was confirmed to have been implemented.

[2. Monitoring of the effect of inhibiting the microbial growth of the coating after a long period of time after applying the coating agent containing the polycarboxylic acid ion complex]
(Example 18)
After monitoring the microbial growth inhibition effect of the coating film at the time of application construction in Example 1, operation of the cooling tower 10 was started. One month after the start of operation, another test piece attached to the louver 19 of the cooling tower 10 was collected and immersed in 10 mL of 99 v / v% ethyl alcohol to extract benzalkonium. The extract was made up to 10 mL with 99 v / v% ethyl alcohol, 1 mL of the extract was mixed with 9 mL of pure water, and quaternary ammonium salt test paper (MQuant (registered trademark) quaternary ammonium salt test, manufactured by Merck & Co., Inc.). ).

(Example 19 to Example 23)
Similarly to Example 18, the cooling tower 10 was started to be operated after monitoring the microbial growth inhibition effect of the coating film during the application work of Examples 2, 6 to 8, and 16. One month after the start of operation, other test pieces attached to the louver 19 of the cooling tower 10 were collected and immersed in 10 mL of 99 v / v% ethyl alcohol to extract the cationic bactericidal agent. The extract was made up to 10 mL with 99 v / v% ethyl alcohol, 1 mL of the extract was mixed with 9 mL of pure water, and quaternary ammonium salt test paper (MQuant (registered trademark) quaternary ammonium salt test, Merck Ltd.). Manufactured). The monitoring tests after the lapse of one month corresponding to Examples 2, 6 to 8, and 16 were set to Examples 19 to 23, respectively.

(Example 24)
After monitoring the microbial growth inhibition effect of the coating film at the time of application construction in Example 1, operation of the cooling tower 10 was started. After one month, two months, and three months from the start of operation, separate test pieces were collected and immersed in 10 mL of 99 v / v% ethyl alcohol to extract cetylpyridinium. After each extract was made up to 10 mL with 99 v / v% ethyl alcohol, 1 mL of the extract was mixed with 9 mL of pure water, and quaternary ammonium salt test paper (MQuant® quaternary ammonium salt test, Merck Ltd.) Measured by company).

  The results are shown in Table 2.

  As shown in Table 2, in Examples 18 to 24, it was found that the cationic fungicide remained even after a long period of time and a maximum of 3 months (Example 24). In addition, as a result of visual observation of the surface of the louver 19 in the vicinity where the test piece was attached, the adhesion of algae and microorganisms was slight in all examples, and the effect of inhibiting the growth of microorganisms by the coating film was maintained. It could be confirmed.

10 Cooling tower (application object)
19 louvers (surface to be coated)
50 test pieces

Claims (7)

A method for monitoring the effect of inhibiting the growth of microorganisms in a coating film formed on a coating object by application of a coating agent containing a polycarboxylic acid ion complex formed from a polycarboxylic acid and a cationic fungicide,
A partitioning step of partitioning a predetermined region from another region of the coating target surface of the coating object before coating of the coating agent containing the polycarboxylic acid ion complex;
An application step of applying an application agent containing the polycarboxylic acid ion complex to the application scheduled surface of the application object;
An organic solvent extraction step of extracting the coating film in the partition region using an organic solvent as an extraction solvent after a coating film by a coating agent containing the polycarboxylate ion complex is formed on the object to be coated;
A quantitative step of quantifying the amount of the cationic bactericidal agent in the extract obtained by the organic solvent extraction step;
A method for monitoring the effect of inhibiting microbial growth, comprising: The partitioning step is performed after the coating step rather than before the coating step;
The division from the other region of the predetermined region is that a mark surrounding the predetermined region is made on the planned application surface or the coating surface of the coating agent after the coating step. Monitoring method.   The method for monitoring a microbial growth inhibitory effect according to claim 1, wherein the division from the other area of the predetermined area is performed by attaching a test piece that is detachable to the planned application surface.   The method for monitoring a microbial growth inhibitory effect according to claim 3, wherein the test piece is made of the same material as the application target surface of the application object.   The polycarboxylic acid is selected from the group consisting of poly-γ-glutamic acid, polyacrylic acid, polymethacrylic acid, a copolymer of methacrylic acid and acrylic acid, and a mixture of two or more thereof. The monitoring method of the microbial growth inhibitory effect of any one of Claims 1.   The method for monitoring a microbial growth inhibitory effect according to any one of claims 1 to 5, wherein the cationic fungicide is one or both of a quaternary ammonium salt and a biguanide fungicide.   The method for monitoring a microbial growth inhibition effect according to any one of claims 1 to 6, wherein the organic solvent is selected from the group consisting of alcohols, ketones, esters, organic chlorines, and hydrocarbons.

Images