JP2017008251A - Antibacterial coating agent composition, antibacterial coated film, and antibacterial and antifungal treatment method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antibacterial coating agent composition and an antibacterial coated film applicable to an aluminum-made fin member of a heat exchanger of an air-conditioning device, having sterilization effect, good in application property (wettability), providing a coated film formed after application which is thin and excellent in adhesiveness to a member and capable of maintaining antibacterial and antifungal effect over long time.SOLUTION: There are provided an antibacterial coated film containing (A) an aqueous urethane resin, (B) a hydrophilic water repellent agent and (C) an isothiazoline-based compound as essential components and containing one or more kind of antibacterial agent selected from an isothiazoline-based compound, a thiazole-based compound, a benzimidazole-based compound and an inorganic antibacterial agent, and an antibacterial coated film obtained by applying the same.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an antibacterial coating agent composition. In detail, the antibacterial coating agent composition which can be used for the inside of the air conditioner (excluding the electrical system) and the exterior, in particular, the aluminum fin member of the heat exchanger, is obtained by applying it. It relates to an antimicrobial coating.

An air conditioner or an air conditioner used for indoor air conditioning (in the present invention, these are collectively referred to as “air conditioner”) may emit a bad odor when the air conditioning operation is started or during operation.
As shown in FIG. 2, an example of an air conditioner used in general households sucks indoor air from the suction port, receives a cold / hot heat from the refrigerant through a filter, passes through a filter, and passes through a blower fan. Designed to blow out from the outlet. A wind direction plate for adjusting the wind direction is installed at the outlet. A drain pan for storing condensed water is installed in the lower part (front and back) of the heat exchanger.
Commercial air conditioning equipment (not shown) introduces fresh outside air from the inlet, mixes part of the indoor air, and is equipped with a filter, cooling coil, heating coil, and humidifier Air is supplied to the machine through the air supply fan, and cool air is supplied indoors through the air outlet, and at the same time, part of the indoor air is exhausted from the air outlet through the air fan, and part of the air is Designed to send to air conditioner. A drain pan (dew tray) for storing condensed water is installed below the cooling coil and the humidifier.

  The above-mentioned bad odor is caused by microorganisms such as mold and bacteria in the indoor air adhering to the heat exchanger together with garbage, and these microorganisms corrupting the deposits such as garbage at an appropriate temperature and humidity. It is said. In particular, the vicinity of a heat exchanger having fin members made of aluminum or aluminum alloy is in an environment in which condensation is likely to occur and mold tends to propagate. Even if cleaning is performed with the air-conditioning equipment installed, mold cannot be completely removed by normal cleaning alone, and mold grows again.

  Therefore, it has been proposed to precoat a heat exchanger with a resin paint to which an antibacterial agent is added (for example, see Patent Document 1). However, if the precoat treatment film is a thin film, the amount of the antibacterial agent added cannot be increased, so that the antibacterial and antifungal effect is insufficient. On the other hand, if the precoat treatment film is made thick, the amount of the antibacterial agent added can be increased, but if it is too thick (about 40 μm or more), there arises a problem of changing the heat efficiency of the heat exchanger. Furthermore, the fins of air conditioning equipment must be free from elution of the added antibacterial agent by running water because condensation occurs in summer, while the antibacterial agent must not volatilize due to heat in winter. If these are not satisfied, the antibacterial and antifungal effect will not be sustained.

  As described above, the coating agent for applying to the aluminum fin member or the like of the heat exchanger has a sterilizing effect, can form a thin film, maintains an antibacterial and antifungal effect for a long period of time, and is also effective for the fin member. What is excellent in applicability | paintability and the adhesiveness of a film are desired. Furthermore, when the coating is transparent, it can be coated on visible parts such as air outlets without impairing the aesthetics of the air conditioning equipment, but if the coating is cloudy, the range of use is visible. Not limited to inside air conditioning equipment.

JP-A-11-281294

  The present invention has been made in view of the above circumstances, and is applicable to an aluminum fin member of a heat exchanger of an air conditioner, has a sterilizing effect, and has applicability (wetability) to the member. An antibacterial coating agent composition and an antibacterial coating film that are good and have a thin film that is excellent in adhesion to a member with a thin film and that can maintain an antibacterial and antifungal effect over a long period of time. The issue is to provide.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have used a water-based urethane resin and a hydrophilic oil repellent in combination, added an isothiazoline-based compound as a main antibacterial agent, and dissolved them in an ethanol water mixed solvent. The antibacterial coating agent composition was prepared, and it was found that a film having excellent adhesion to the fin member and capable of forming a thin film and which does not lose the antibacterial and antifungal effect by running water was obtained, and the present invention was completed. It came to.

  That is, the gist of the present invention is as follows.

(1) An antibacterial coating agent composition comprising one or more antibacterial agents including (A) an aqueous urethane resin, (B) a hydrophilic oil repellent, and (C) an isothiazoline compound.
(2) The antibacterial property according to (1), wherein (C) the antibacterial agent is one or more antibacterial agents selected from isothiazoline compounds, thiazole compounds, benzimidazole compounds and inorganic antibacterial agents. Coating agent composition.
(3) The antibacterial coating agent composition according to (1) or (2), further comprising (D) ethanol.
(4) The content of the antibacterial coating agent composition is (A) water-based urethane resin: 1 to 20% by weight, (B) hydrophilic oil repellent: 0.1 to 5% by weight, (C) antibacterial agent: 0. The antibacterial coating agent composition according to (1), which is 1 to 5% by weight.
(5) An antibacterial coating film obtained by applying the antibacterial coating agent composition according to any one of (1) to (4).
(6) The antibacterial coating film according to (5), wherein the film thickness is 1 to 30 μm.

  According to the present invention, an antibacterial coating agent composition that exhibits antibacterial and antifungal properties against a wide range of fungi and bacteria by combining an antibacterial agent containing water-based urethane resin, hydrophilic oil repellent and isothiazoline compounds as essential components Can be provided. Moreover, since the coating agent is hydrophilic, the coating operation is easy and the adhesion to the fin member is excellent. Spraying after normal washing and drying operations can give a strong antibacterial, antibacterial and antifungal effect, and can retain the antibacterial and antifungal effect for a long time after the condensed water of the heat exchanger flows. Since the coating film is a thin film, it can also be used as a pre-coating treatment film around the heat exchanger where condensation and mold easily propagate.

The surface schematic diagram of a fluorine-type hydrophilic oil repellent. Explanatory drawing which shows the structural example of an air conditioner.

Hereinafter, the present invention will be described in detail.
In the present invention, the term “antibacterial” refers to inhibiting the generation, growth, and proliferation of microorganisms, and particularly refers to inhibiting the growth of bacteria on the surface of products. The term “mold prevention” refers to inhibiting the generation, growth, and growth of mold. The above definitions of “antibacterial” and “antifungal” were based on the document “Antimicrobial / antifungal technology” (Toray Research Center, Inc., Research and Research Department, 2004, p22).

<(A) Water-based urethane resin>
The (A) water-based urethane resin used in the antibacterial coating agent composition of the present invention imparts film-forming properties and hydrophilicity when forming an antibacterial coating film, and supports the antibacterial agent in the coating film with running water. There is a function to prevent leakage. The water-based urethane resin can be used by being dispersed or dissolved in water or an aqueous solvent.
The polyisocyanate compound in the water-based urethane resin is not particularly limited, but a diisocyanate compound having two isocyanate groups per molecule is preferable. Of the polyisocyanate compounds, aliphatic polyisocyanate compounds and alicyclic polyisocyanate compounds are preferable, and aliphatic polyisocyanate compounds are particularly preferable. By using an aliphatic polyisocyanate compound, it is possible to obtain a coating film that is difficult to yellow, and the resulting coating film tends to have higher water resistance.

  Specific examples of the aliphatic polyisocyanate compound include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, or trimers of these isocyanates. These polyisocyanate compounds may be used alone or in combination of two or more. Among the aliphatic polyisocyanate compounds, those having hexamethylene diisocyanate trimer as an essential component are preferable.

The polyol compound in the water-based urethane resin is preferably a polyhydric alcohol having two or more hydroxyl groups in one molecule. By using a polyhydric alcohol, hydrophilicity can be imparted to the antibacterial coating agent composition, and it is easy to disperse or dissolve in water or a solvent. The adhesion to the aluminum fin member is also excellent.
Examples of the polyhydric alcohol having two or more hydroxyl groups in one molecule include diol compounds such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol and glycerin, triol compounds such as trimethylolpropane, pentaerythritol, and the like. And polyhydric alcohols such as tetraol compounds. Of the polyhydric alcohols, diol compounds are preferred. By using a diol compound, the viscosity increase at the time of preparing a coating agent composition can be suppressed, and liquid preparation tends to be facilitated.

  The water-based urethane resin in the present invention may be any one obtained by reacting (a) a polyisocyanate compound and (b) a polyol compound in the presence or absence of a catalyst. Although the said catalyst is not specifically limited, For example, an amine catalyst (A triethylamine, N-ethylmorpholine, a triethylenediamine etc.) etc. are mentioned. The amount of (b) used is preferably about 1.0 to 2.0 times on a molar basis with respect to (a).

Water-based urethane resin adheres to aluminum fin members of heat exchangers, air inlets, air inlets, air outlets, air outlet walls, fans, wind direction plates, dampers, upper and lower drain pans, drain piping, etc. Excellent in properties. Therefore, even when wind is received from the blower fan, there is no peeling or peeling of the coating film. In addition, it is possible to form a thin film that could not be achieved with a coating agent using an acrylic resin emulsion or a vinyl acetate resin emulsion as a film-forming material.
In addition, since the ventilation path of the air conditioner is a ventilation path of cold air and warm air, there is a special circumstance that the temperature change is very severe. Such a temperature change causes the coating film to continuously expand and contract. Therefore, the coating film is required to have excellent followability to expansion and contraction, not to be softened by warm air, and not to be embrittled by cold air. In that respect, the urethane resin is a preferable material in that the elongation at break of the coating film is large and the stretchability of the coating film is excellent.

  The content of the water-based urethane resin affects the film formability. The water-based urethane resin is preferably 1 to 20% by weight, more preferably 2 to 15% by weight, and particularly preferably 3 to 10% by weight based on the total weight of the antibacterial coating agent composition. If the content is within the above range, an antibacterial coating film excellent in adhesion to stainless steel, aluminum, aluminum alloy, etc., water resistance and antimicrobial agent supportability can be formed. If the content is 20% by weight or less, the viscosity of the antibacterial coating agent composition becomes too high, and there will be no inconvenience such as difficult application work.

<(B) Hydrophilic oil repellent>
The (B) hydrophilic oil repellent used in the antibacterial coating agent composition of the present invention has an effect of imparting hydrophilicity to the formed coating film. A hydrophilic lube repellent is a compound having both a hydrophilic group and a hydrophobic group in the molecule. The hydrophobic group is oriented on the surface in air and the hydrophilic group is oriented on the surface in water. Although the kind of hydrophilic oil repellent is not specifically limited, A fluorine-type hydrophilic oil repellent is preferable.

Perfluoroalkyl ethyl acrylate / 2-hydroxyethyl methacrylate copolymer (SR polymer) and the like are known as fluorine-based hydrophilic oil repellents. FIG. 1 is a schematic view of an SR polymer surface. In air, perfluoroalkyl (Rf) groups are oriented on the surface, and hydroxyl groups are lurked inside. On the other hand, the Rf group retreats in water, so that hydroxyl groups are relatively oriented on the surface. (Source: J. Soc. Cosmet. Chem. Japan Vol. 36, No. 1 2002)
As the fluorine-based hydrophilic oil repellent, other than the SR polymer, a similar polymer can be used. Examples thereof include a copolymer of (meth) acrylate having a C 3-20 perfluoroalkyl group and alkylene glycol (meth) acrylate.

  The hydrophilic oil repellent is preferably 0.1 to 5% by weight, more preferably 0.15 to 3% by weight, particularly preferably 0.2 to 1% by weight, based on the total weight of the antibacterial coating agent composition. It is good. When the content is within the above range, an antibacterial coating film having good antibacterial activity durability can be formed.

<(C) Antibacterial agent>
The antibacterial coating agent composition of the present invention contains at least one type or two or more types of antibacterial agents for the purpose of imparting antibacterial and antifungal properties to the coating film. The antibacterial agent contains an isothiazoline-based compound as an essential component. Isothiazoline compounds exhibit high activity and broad spectrum against bacteria and fungi. Since it has bactericidal and anticorrosive properties, there is no risk of corroding the aluminum fin material or the like. The isothiazoline compounds may be used alone or in combination of two or more. By using multiple species together, there is an advantage that the antibacterial activity against various bacteria can be enhanced.

Examples of the isothiazoline-based compound include compounds represented by the following formula (1) or formula (2). In the formula, R ¹¹ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and R ^{12 to} R ¹⁷ each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Examples of the alkyl group having 1 to 10 carbon atoms in R ^11, for example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, heptyl group, octyl group, nonyl group, decyl group. The alkyl group having 1 to 6 carbon atoms in R ¹² to R ^17, for example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group and the like.

  Preferred compounds among the isothiazoline-based compounds include 2-n-octyl-4-isothiazolin-3-one [OIT], 2-methyl-4-isothiazolin-3-one [MIT], 2-methyl-4, 5-trimethylene-4-isothiazolin-3-one [MTI], 1,2-benzisothiazolin-3-one [BIT], Nn-butyl-1,2-benzisothiazolin-3-one [Bu-BIT] Etc. These isothiazoline-based compounds have the advantage that they are antimicrobial, have no fear of volatilization even when exposed to high temperatures, and are easy to handle. Among these, OIT, MIT, BIT, and Bu-BIT are preferable, and OIT, MIT, and Bu-BIT are particularly preferable in terms of excellent solubility in water-based urethane resins and aqueous solvents.

  In order to obtain a broad antibacterial spectrum, it is more preferable to use two or more isothiazoline compounds in combination. In particular, when OIT is used in combination with MIT or Bu-BIT, it is preferable to use more OIT having excellent heat resistance than MIT or Bu-BIT. A preferable combination ratio (weight ratio) is in the range of OIT / MIT or Bu-BIT = 99/1 to 55/45, and more preferably in the range of 99/1 to 70/30. OIT exhibits a sufficient effect even by itself, but the bactericidal power against general bacteria can be enhanced by using MIT or Bu-BIT together. In particular, it is preferable to use OIT 5 times or more of MIT or Bu-BIT by weight ratio.

An isothiazoline-based compound may be used in combination with one or more antibacterial agents selected from other antibacterial agents.
Other antibacterial agents include silver compounds, zinc compounds, alcohol compounds, phenol compounds, quaternary ammonium salts, benzoic acids, chlorhexidine, sorbic acids, organic nitrogen compounds, sulfur compounds, 1,2-bis. Examples thereof include halogen compounds such as (bromoacetoxy) ethane and bis (1,4-bromoacetoxy) -2-butene, organic acid esters, organic iodine compounds, and pyrithione compounds such as zinc pyrithione (ZPT).
Among these antibacterial agents, thiazole compounds, benzimidazoles compounds, and inorganics have a very high activity and a broad spectrum against mold, and have a relatively high melting point and excellent volatility under hot air. Antibacterial agents are preferred. Specific examples of the compound include 2- (4-thiazolyl) benzimidazole [TBZ], 2- (methoxycarbonylamino) -1H-benzimidazole [BCM], 2- (4-thiocyanomethylthio) benzothiazole [ And pyrithione compounds such as zinc bis (2-pyridylthio-1-oxide) [zinc pyrithione: ZPT]. TBZ is sparingly soluble in water and organic solvents, but exhibits very high activity against mold and a broad spectrum, and has a high melting point (about 300 ° C.), so it has excellent volatility under hot air. The same applies to ZPT.

The total content of the antibacterial agent affects the sterilizing power and antibacterial power of the coating film. For this reason, the antibacterial agent is preferably 0.1 to 5% by weight, more preferably 0.15 to 4% by weight, particularly preferably 0.2 to 3% by weight, based on the total weight of the antibacterial coating agent composition. % Should be good. If content is in the said range, the antibacterial coating agent composition which is excellent in bactericidal power and antibacterial power can be provided.
In addition, the other antibacterial agents described above can be used in combination with an isothiazoline-based compound within a range that does not inhibit the effect of the present invention, and the optimum composition is determined according to the place where the antibacterial coating agent composition is applied. good. In this case, it is preferable that the weight ratio of the isothiazoline-based compound is 50% or more of the total antibacterial agent from the viewpoint of imparting sufficient bactericidal power, antibacterial power, and antibacterial power durability to the coating film. More preferably, it is 70% or more, More preferably, it is 80% or more.

  In the antibacterial coating agent composition of the present invention, (D) ethanol is preferably used as a solvent for dissolving the components (A), (B), and (C). Ethanol has the effect of sterilizing mold and bacteria present on the target surface to which the antibacterial coating agent composition is applied. Ethanol may be used as a mixture with isopropyl alcohol, 1-propanol or the like.

  Ethanol or a mixture thereof is preferably 25 to 70% by weight, more preferably 30 to 60% by weight, and particularly preferably 35 to 55% by weight based on the total weight of the antibacterial coating agent composition. If content is in the said range, the antimicrobial coating agent composition which has the bactericidal power in which the water-based urethane resin is disperse | distributing uniformly or melt | dissolved will be obtained. The transparency of the coating film is also excellent.

  The antibacterial coating agent composition of the present invention preferably contains (E) a dispersant as a component for dispersing the antibacterial agent. A dispersing agent may be used independently and may use multiple types together. Examples of the dispersant include polyethylene glycol, propylene glycol, dipropylene glycol, glycerin, xylitol, and sorbitol. Among these dispersants, propylene glycol having an antibacterial action is preferable.

  The polyhydric alcohol used as a dispersant imparts hydrophilicity to the antibacterial coating, protects the antibacterial agent carried on the antibacterial coating from the dry state, and exerts the function of the antibacterial agent over a long period of time There is. In general, antibacterial agents cannot function sufficiently in a dry state, but by adding a polyhydric alcohol, it is possible to prevent molds and bacteria from becoming wild fungi with resistance to antibacterial agents. The polyhydric alcohol compound may be filled with an excess polyol compound used when the aqueous urethane resin is produced.

  The content of the dispersant is preferably 0.5 to 10% by weight, more preferably 0.7 to 7% by weight, particularly preferably 1 to 3% by weight, based on the total weight of the antibacterial coating agent composition. is there. If content is in the said range, the dispersibility of an antibacterial agent can be hold | maintained. Even if it exceeds 10% by weight, it is difficult to improve the effect greatly.

  The antibacterial coating agent composition of the present invention can be made into a composition by blending each of the above components (A) to (E), other components, and the like in a balanced amount of water. The water may be deionized water, pure water, or tap water. In addition to the above active ingredients, the antibacterial coating agent composition of the present invention comprises an ultraviolet absorber, a light stabilizer, a filler, a plasticizer, a pigment, a colorant, an antiseptic, an antifoaming agent, a surfactant, a charging agent. Arbitrary components, such as an inhibitor, a deodorant, a moisturizer, a pH adjuster, and a fragrance | flavor, can be added 1 type, or 2 or more types in the range which does not inhibit the effect by this invention.

  The viscosity required for the antibacterial coating agent composition varies depending on the means for applying it, such as brushing or spraying. Therefore, it is desirable to adjust the viscosity of the antibacterial coating agent composition by appropriately increasing or decreasing the content of each component according to the purpose.

  For example, an antifoaming agent can be included in order to stir the above-mentioned essential components and suppress foam generated when preparing an antibacterial coating agent. Moreover, in order to provide a deodorant effect, a deodorizer can be contained, and in order to improve the flame retardance of a coating film, a flame retardant can be contained. Although there is no restriction | limiting in particular regarding the kind of these antifoamer, a deodorizer, and a flame retardant, As a defoamer, a silicone type thing is preferable.

  The antibacterial / antifungal treatment method of the present invention includes a step of applying the antibacterial coating agent of the present invention. When applying an antibacterial coating agent, it is preferable to wipe and clean the surface to be coated before application in order to suppress the growth of mold and bacteria as much as possible. The wiping and cleaning may be performed by a method capable of removing mold and bacteria on the application target surface, and is not particularly limited. For example, a method of wiping the surface to be coated with a waste cloth, paper or the like containing 70% or more of alcohol (ethanol, isopropanol) can be used.

Next, the antibacterial coating agent composition of the present invention is applied to the surface to be coated after wiping and washing, and dried to form an antibacterial coating film. The coating can be performed by a known method such as a roll coating method, a spray coating method, a dipping method, a flow coating method, a spin coating method, a brush coating method, or a trowel coating method. Among these, the spray coating method is preferable because it is easy to form a thin film and can be applied to the inner part (for example, the upper drain pan) of the air conditioner using a long nozzle.
The coating amount is not particularly limited, but if the coating amount is small, it becomes impossible to uniformly apply to a desired location, so that sufficient antibacterial properties cannot be imparted to the coating film. On the other hand, if the coating amount is too large, it acts on the heat exchanger of the air conditioner and adversely affects the thermal efficiency. Therefore, the film thickness after drying is preferably 40 μm or less, more preferably about 1 to 30 μm. .
Drying after coating can be performed by natural drying or heating (preferably 70 ° C. or less) or forced drying by air blowing, and the drying time may be about 0.5 to 24 hours.

  The antibacterial coating agent composition of the present invention is mainly composed of an intake port, an air outlet, a ventilation path wall, a fan, a wind direction plate, a damper, a drain pan (upper and lower), a drain pipe, and a heat exchanger aluminum constituting an air conditioner. It can apply | coat suitably to members, such as a fin-made member. The air conditioner may be an existing air conditioner or an unused (new) air conditioner, and the use is not limited. In addition to air-conditioning equipment, the present invention can also be applied to the antibacterial surface exposed to the same environment as the above members. Examples of such antibacterial surfaces include floors, walls, ceilings, outer wall materials, etc. of building structures; food production equipment; food storage; surface of water tanks; sink outlets;

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples. In the following examples and the like, “% by weight” is abbreviated as “%” unless otherwise specified.

The antibacterial agents used in Examples and Comparative Examples are as follows.
OIT; 2-n-octyl-4-isothiazolin-3-one MIT; 2-methyl-4-isothiazolin-3-one Bu-BIT; Nn-butyl-1,2-benzisothiazolin-3-one TBZ; 2- (4-thiazolyl) benzimidazole BCM; 2- (methoxycarbonylamino) -1H-benzimidazole ZPT; zinc pyrithione BAE; 1,2-bis (bromoacetoxy) ethane BAB; bis (1,4-bromoacetoxy)- 2-butene

(Examples 1-12)
Water (balance amount), antibacterial agent, fluorine-based hydrophilic oil repellent, antifoaming agent, and propylene glycol were mixed, and then the water-based urethane resin was added and stirred while stirring them. Thereafter, ethanol was added to prepare an antibacterial coating agent composition having the composition described in Table 1.

(Comparative Examples 1-3)
A coating agent composition having the composition shown in Table 1 and containing no fluorine-based hydrophilic oil repellent was prepared.

(Comparative Example 4)
A coating agent composition containing an acrylic resin emulsion was prepared instead of the water-based urethane resin.

  About the prepared antimicrobial coating agent composition (henceforth a chemical | medical agent), the applicability | paintability test, the bactericidal test, the halo test, the flowing water test, and the adhesiveness test were implemented by the following method. Table 2 shows the evaluation results and the thickness of the coating film formed on the aluminum plate.

(I) The wettability and the transparency of the coating film when the coating agent is applied to the aluminum plate are evaluated.

(Ii) Bactericidal power of the drug (a) Test bacteria (both using wild strains):
1: Alternaria sp.
2: 3 Species mixed bacteria ... Penicillium sp.
Cladosporium sp.
Aspergillus sp. (Aspergillus sp.)
3: General bacteria (b) Test method:
Preparation of drug solution: Prepare 2 ml of drug in a sterilized test tube.
Preparation of bacterial solution: The test bacteria are adjusted to 1 × 10 ⁵ cfu / ml with sterilized purified water.
Contact: 100 μl of the bacterial solution is added to the chemical solution and brought into contact for 30 seconds to obtain the test solution.
Smear: 100 μl of the test solution is smeared on PDALP medium (0.1% lecithin and 0.7% polysorbate 80 added to PDA medium). For general bacteria, smear on LP medium (0.1% lecithin and 0.7% polysorbate 80 added to standard agar medium).
(C) Culture conditions: 27 ° C. for 1 week, general bacteria at 37 ° C. for 1 week.
(D) Colony measurement: Comparison is made with an average value of N = 2 or 3.

(Iii) Antibacterial activity of drugs (Hello test)
(A) Test bacteria: (ii) Same as (a).
(B) Test method:
Spray the drug evenly onto a 125 mmφ filter paper (Advantech) (spray amount: approx. 2 ml) and let it air-dry overnight. Cut the filter paper to 28 mmφ. Take 1 platinum loop of the isolated strain and smear it on PDA medium. For general bacteria, smear on standard agar medium. Place the cut filter paper in the center.
(C) Culture conditions: PDA medium is 27 ° C. for 2 weeks, general bacteria is 37 ° C. for 2 weeks.
(D) Halo measurement: An average value of N = 3 is calculated and evaluated according to the following criteria.
No growth of hyphae is observed in the inoculated part of the “◯” sample or test piece.
The area of the growth part of the mycelium observed in the inoculated part of the “Δ” sample or test piece does not exceed 1/3 of the total area.
The area of the growth part of the mycelium observed in the inoculated part of the “x” sample or the test piece exceeds 1/3 of the total area.

(Iv) Check the antibacterial activity of a test piece (aluminum plate) from which the long-lasting antibacterial agent does not dissolve after running water .
(A) Test bacteria: (ii) Same as (a).
(B) Test method:
Apply the drug evenly on a 4cm square aluminum plate and let it air dry for one day. 50 cc / min running water is dropped on an air-dried aluminum plate for 48 hours. Air-dry for 1 day and night, and place an aluminum plate cut into a 1 cm square on the center of the PDA medium smeared with the test bacteria (standard agar medium is used for smearing general bacteria).
(C) Culture conditions: PDA medium at 27 ° C. for 2 weeks, standard agar medium at 37 ° C. for 2 weeks.
(D) Measurement of halo: Comparison is made with measured values of halo before running water and after running water (average value of N = 3).

(V) Adhesiveness of coating film 1 Adhesion to an aluminum plate air-dried day and night is evaluated.
Using an elcometer 107 crosshatch cutter (Innext, Inc.), a wound with a length of about 20 mm is made on the coating film formed on the aluminum plate and cut in the same manner at right angles to the cut to form a lattice pattern. A cellophane tape is applied to the lattice pattern divided into 100, and then peeled off. Observe the peeling condition of the coating material and evaluate it according to the following criteria.
"ISO classification 0" The cut edges are completely smooth and no squares of the grid are peeled off.
A small flake-shaped peeling is seen at the intersection of “ISO classification 1” cuts.
There is a flake-like flaking of the coating along the “ISO Class 2” edge or the point where the cuts meet.
Flakes off partially or entirely along the edge of the “ISO classification 3” cut, or some or all of the different parts of the square are peeled off.
The coating is flake-off partially or entirely along the edge of the “ISO Class 4” cut. Part or all of the square part is peeled off.
Further flaking (peeling) that does not apply to "ISO classification 5" classification 4.

From the results of Table 2, the antibacterial coating agent composition of the present invention is a combination of two isothiazoline antibacterial agents (OIT / MIT (Examples 1, 4, 10), OIT / Bu-BIT (Example 5)). In addition, in the combination of the isothiazoline antibacterial agent and other antibacterial agents (Examples 6 to 7, 11 to 12), excellent sterilization effect (bacterial survival rate 0%), antibacterial activity (halo diameter) and antibacterial activity Sustained power (halo diameter after 48 hours of running water) was observed. The sterilizing effect, antibacterial activity, and antibacterial activity persistence were also observed when the antibacterial agent content was 0.2 to 0.3% by weight (Example 3). In the case of using OIT alone (Example 8), sterilization effect and antibacterial activity were recognized, but compared with the case of using it together with other antibacterial agents, the bactericidal activity against general bacteria and the antibacterial activity against 3 species mixed bacteria Slightly inferior in terms.
The bactericidal power against general bacteria tended to depend on the amount of MIT added. Further, the antibacterial activity (halo diameter) tends to depend on the amount of OIT added, and the halo diameter decreased as the amount of OIT added decreased.
The antibacterial coating agent composition of the present invention was excellent in antibacterial sustainability (the effect was not lost by running water) because halo was confirmed even after running for 48 hours in all test sections, and adhesiveness to the aluminum plate It was confirmed to be excellent.
However, the antibacterial coating agent compositions of Example 6 and Example 7 were solidified over time and were not suitable for spraying.
In addition, the antibacterial coating agent compositions of Examples 11 and 12 containing TBZ, BCM and ZPT (all of which are sparingly soluble powders) are used in places other than visible places such as the air outlet because the coating film becomes cloudy. Is desirable.

  On the other hand, since the coating agent compositions of Comparative Examples 1 to 3 that do not contain a hydrophilic oil repellent agent exhibit a slight water repellency when applied to an aluminum plate (poor wettability), when applied to a heat exchanger, water droplets appear. There is a possibility that a bridge is formed between the fins and a water splash phenomenon occurs in which water droplets fly from the air outlet. Furthermore, if it is not hydrophilic, contamination accumulates and heat exchange efficiency is hindered. In addition, the coating agent compositions of Comparative Examples 2 and 3 not containing an isothiazoline-based compound have inferior antibacterial activity, and the tendency is remarkable when propylene glycol is not added (Comparative Example 2). . The coating composition of Comparative Example 4 based on an acrylic resin had a result equivalent to the example of the present invention (bacterial survival rate 0%), but the film thickness of the coating film was about 50 μm. It was not applicable to the exchanger.

(Example 13)
The product of the present invention (Example 1) was compared with the antibacterial, antibacterial and antifungal coating agents of other companies. The evaluation method of the bactericidal power and antibacterial power of the drug was based on Example 1 except that the test bacteria shown below were used. The test results are shown in Tables 3 and 4.

<Test bacteria (both use wild strains)>
1: Alternaria sp.
2: 3 Species mixed bacteria ... Penicillium sp.
Cladosporium sp.
Aspergillus sp. (Aspergillus sp.)

  From the results shown in Table 3, the sterilization effect was confirmed in all test sections for Alternaria. About 3 species mixed bacteria, the sterilization effect was not able to be confirmed in the other brands Y and Z. The test plot that had 100% sterilization effect for both test bacteria was the product of the present invention and the product X of other companies.

  From the results shown in Table 4, the product of the present invention was found to have high antibacterial activity against both Alternaria and three species mixed bacteria.

(Example 14)
The product of the present invention (Example 1) and the antibacterial / antibacterial / antifungal coating agent (hereinafter referred to as a drug) of the other company's product are applied to the test piece, and the antibacterial activity value for the test piece coated with the drug is obtained. The antibacterial effect was evaluated. The results are shown in Table 5. The evaluation method is shown below.

<Method for evaluating antibacterial activity of drug-coated specimen>
(1) Test bacteria (using wild strain): Cladosporium sp.
(2) Test method:
Preparation of test piece: Apply the drug evenly on an aluminum plate and dry it all day and night.
Bacterial solution preparation: The isolated strain is picked and suspended in sterilized purified water so as to be 1 × 10 ⁵ cfu / ml.
Contact: 100 μl of the bacterial solution is taken and brought into contact with the aluminum plate coated with the drug.
Washing out: After contact for a specified time, wash out with 10 ml of sterilized physiological saline. 100 μl of the washed bacterial solution is smeared on PDA medium, and the number of bacteria in the washed solution is determined.
Evaluation: The bacteriostatic activity value is obtained by the following method, and the antibacterial / deodorant effect is determined.
Bacteriostatic activity value = {log (standard cloth, viable count after 18 hours culture) -log (standard cloth, viable count immediately after inoculation)}-{log (sample, viable count after 18 hours culture) -log (sample, inoculation) Immediately after the number of viable bacteria)}
Determination: Bacteriostatic activity value ≧ 2.0 was determined to be acceptable.
(3) Culture conditions: PDA medium 27 ° C., 18 hours.
(4) Counting of colonies: Comparison is made with an average value of N = 3.
(5) Evaluation of drug adhesion: As in Example 1, an aluminum plate that was air-dried for one day was used.

From the results in Table 5, the product of the present invention was excellent in the transparency (film thickness: about 15 μm) of the coating film and the antibacterial and antifungal properties. Adhesiveness was good for both the aluminum plate and the copper plate. Since water-based polyurethane resin and fluorine-based hydrophilic oil repellent (fluorine polymer) are blended, it is considered that the adhesiveness is excellent.
On the other hand, the other company's product X is concerned about the use to the place seen from the outside since the coating film is colored. The adhesiveness was also poor, and all of the drug had moved to the cellophane tape side. Since the adhesive state of the drug is extremely poor and easily peels off from the plate, it is considered that the residual effect of the drug is not exhibited. Competitor Y had good coating film transparency and chemical adhesiveness on both the aluminum plate and the copper plate, but no antifungal property was observed.

(Example 15)
The antibacterial sustainability after running water was confirmed using a test piece (aluminum plate) from which the drug hardly dissolves. After the drug was applied to the aluminum plate, the difference in antibacterial activity with and without heat treatment (60 ° C. for 30 minutes) was also evaluated. The evaluation method was based on Example 1 except that the test bacteria shown below were used.

<Test bacteria (both use wild strains)>
1: Alternaria sp.
2: 3 Species mixed bacteria ... Penicillium sp.
Cladosporium sp.
Aspergillus sp. (Aspergillus sp.)
3: General bacteria

  From the results shown in Table 6, the product of the present invention slightly increased or decreased with or without heat treatment, but there was almost no influence by heat treatment. The product of the present invention was found to have a halo after running water in any of the test sections, and it was confirmed that the antibacterial activity persistence was higher than those of other companies.

(Example 16)
About this invention product (Example 1), the flowing water limit in each test section was confirmed and evaluated. The results are shown in Table 7. The evaluation method is shown below.

<Running water limit test method>
(1) Test bacteria (both use wild strains)
1: Alternaria sp.
2: 3 Species mixed bacteria ... Penicillium sp.
Cladosporium sp.
Aspergillus sp. (Aspergillus sp.)
3: General bacteria (2) Test method:
Apply the drug evenly on a 4cm square aluminum plate and let it air dry for one day. 50 cc / min running water is dropped onto an air-dried aluminum plate for 120 hours.
* Severe test conditions equivalent to about 3.5 years with 120 hours of running water.
Air-dry for 1 day and night, and place an aluminum plate cut into a 1 cm square on the center of the PDA medium smeared with the test bacteria (standard agar medium is used for smearing general bacteria).
(3) Culture conditions: PDA medium at 27 ° C. for 2 weeks, standard agar medium at 37 ° C. for 2 weeks.
(4) Measurement of halo: Comparison between measured values of halo before running water and after running water (average value of N = 3).

  From the results shown in Table 7, halo was confirmed even after running water for 120 hours in the test area of Alternaria.

(Example 17)
The product of the present invention (Example 1) was applied to a rest room air conditioner of a food factory so as to have an average film thickness of about 15 μm. The application target surface was an upper drain pan, a main drain pan, a fan, a blower outlet, a blowout blade, a heat exchanger front surface, and a heat exchanger rear surface.
The experiment was carried out by the following three methods and compared with the case where only the member was disassembled and cleaned.
(1) The product of the present invention is applied after normal wall-mounted cleaning.
(2) The product of the present invention is applied without washing.
(3) The product of the present invention is applied after disassembling and cleaning the members.

  The degree of mold contamination on each application target surface was evaluated in five stages based on the evaluation criteria shown in Table 8. The results are shown in Table 9.

From the results of Tables 8 and 9, it can be seen that by applying the present invention product after wall-washing, the number of attached fungi and the number of airborne fungi on the air conditioner member are significantly reduced, and the effect is generally maintained even after 3 months of construction. I understand.
When the product of the present invention is applied to a contaminated part without wall-washing, the agent cannot be permeated into the part where the medicine is difficult to reach by spraying, such as a fan, and the contamination should be reduced. I could not.
In addition, although the degree of contamination is reduced by disassembly and cleaning under the drain pump, fan, air outlet, and heat exchanger, a clean environment can be obtained by applying the product of the present invention. On the other hand, when only decomposition cleaning was performed, the number of attached fungi decreased after cleaning, but became severely contaminated after 3 months of construction.

  The antibacterial coating of the present invention not only imparts antibacterial / antifungal properties to the member but also maintains its effect for a long period of time. Since the film is transparent, it can be widely applied to air conditioner components, and it has a remarkable feature that was not found in conventional antibacterial coating agents in that the thermal efficiency does not change even when applied to a heat exchanger. . By applying it to the components of the air conditioner, it is possible to suppress the growth of bacteria and mold, and no bad odor is generated during the operation period, so that a comfortable indoor environment can be provided. In addition, by forming the antibacterial / antifungal film, the frequency of cleaning the air conditioner can be lowered, so that an effect in terms of work and economy can be expected. Therefore, the contribution to the improvement of the indoor environment in food factories, pharmaceutical factories, hospitals, schools, offices, automobiles, vehicles, general households, etc. is extremely large.

  The antibacterial coating agent of the present invention can be widely used for textile products such as curtains, clothes, shoes, bags, etc .; metal products such as sinks and drains, and plastic products.

The present invention relates to an antibacterial coating agent composition. In detail, the antibacterial coating agent composition which can be used for the inside of the air conditioner (excluding the electrical system) and the exterior, in particular, the aluminum fin member of the heat exchanger, is obtained by applying it. The present invention relates to an antibacterial coating and an antibacterial / antifungal treatment method .

The present invention has been made in view of the above circumstances, and is applicable to an aluminum fin member of a heat exchanger of an air conditioner, has a sterilizing effect, and has applicability (wetability) to the member. An antibacterial coating agent composition and an antibacterial coating film , which are good and the film formed after coating is a thin film and excellent in adhesion to a member and can maintain an antibacterial and antifungal effect over a long period of time , An object is to provide an antibacterial / antifungal treatment method .

(1) (A) Water-based urethane resin, (B) Copolymer of perfluoroalkylethyl acrylate and 2-hydroxyethyl methacrylate, or (meth) acrylate and alkylene having a C3-20 perfluoroalkyl group Fluorine-based hydrophilic oil repellent comprising a copolymer with glycol (meth) acrylate , ( C) one or more antibacterial agents including isothiazoline-based compounds , and (D) ethanol . Coating agent composition.
( 2 ) The content of the antibacterial coating agent composition is (A) water-based urethane resin: 1 to 20% by weight, (B) fluorine-based hydrophilic oil repellent: 0.1 to 5% by weight, (C) antibacterial agent: The antibacterial coating agent composition according to the above (1), which is 0.1 to 5% by weight and (D) ethanol: 25 to 70% by weight .
(3) The antibacterial coating composition according to (1) or (2 ), further comprising (E) a dispersant, such as polyethylene glycol, propylene glycol, dipropylene glycol, glycerin, xylitol, or sorbitol.
( 4 ) The above (1) to (3) , wherein the antibacterial agent (C) is one or more antibacterial agents selected from isothiazoline compounds, thiazole compounds, benzimidazole compounds and inorganic antibacterial agents. Any antibacterial coating agent composition of description.
(5) The antibacterial coating agent composition according to any one of the above (1) to (4), wherein the (C) isothiazoline compound is one or more selected from isothiazoline-3-one compounds.
(6) The antibacterial coating agent composition according to any one of (1) to (5), which is used for a member of an air conditioner.
( 7 ) The antibacterial coating film formed from the antibacterial coating agent composition in any one of said (1)-( 6 ).
( 8 ) The antibacterial coating film according to ( 7 ), wherein the film thickness is 1 to 30 μm.
(9) Suction port, air outlet, ventilating wall, fan, wind direction plate, damper, drain pan, drain pipe, heat exchanger made of aluminum for the air conditioner having the antibacterial coating film according to (7) or (8) Fin member.
(10) The antibacterial coating agent composition according to any one of the above (1) to (6) is used as a suction port, an air outlet, a ventilation path wall, a fan, a wind direction plate, a damper, a drain pan, a drain pipe, and heat exchange of an air conditioner. A method for forming an antibacterial coating film, characterized in that it is applied to an aluminum fin member of a vessel and dried to form a coating film having a thickness of 1 to 30 μm.
(11) An antibacterial / antifungal treatment characterized in that the antibacterial coating agent composition according to any one of (1) to (6) is applied to a surface to be applied and dried to form an antibacterial coating film. Method.

Claims (6)

  An antibacterial coating agent composition comprising (A) an aqueous urethane resin, (B) a hydrophilic oil repellent, and (C) one or more antibacterial agents including an isothiazoline compound.   (C) The antibacterial coating agent composition according to claim 1, wherein the antibacterial agent is one or more antibacterial agents selected from isothiazoline compounds, thiazole compounds, benzimidazole compounds and inorganic antibacterial agents. .   The antibacterial coating agent composition according to claim 1 or 2, further comprising (D) ethanol.   The content of the antibacterial coating agent composition is (A) water-based urethane resin: 1 to 20% by weight, (B) hydrophilic oil repellent: 0.1 to 5% by weight, (C) antibacterial agent: 0.1 to 5 The antibacterial coating agent composition according to claim 1, wherein the composition is% by weight.   The antimicrobial coating film obtained by apply | coating the antimicrobial coating agent composition in any one of Claims 1-4.   The antibacterial coating film of Claim 5 whose film thickness is 1-30 micrometers.

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