JP2000191419A - Microbicidal composition used for laminating heat exchanger fins and heat exchanger fin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a microbicidal composition used for laminating heat exchanger fins, capable of inhibiting the generation of bacteria and fungi and preventing the generation of an unpleasant smell over a long period, and capable of maintaining a hydrophilic effect and a water-wetting effect over a long period, and to provide the heat exchanger fins. SOLUTION: This microbicidal composition used for laminating heat exchanger fins contains a polymeric microbicide and particles, has an eluted amount of <=0.2 g/m2 when immersed in 40 deg.C water for 120 hr and a water contact angle of <=25 deg., and further has a water contact angle of <=25 deg. also after immersed 40 deg.C water for 120 hr.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an antibacterial composition having excellent antibacterial and antifungal properties, hydrophilicity and durability, and a fin for a heat exchanger.

[0002]

2. Description of the Related Art Generally, in a heat exchanger used for an air conditioner, condensed water generated during cooling becomes water droplets and accumulates between fins to form a bridge of water. appear. As a measure to prevent such a phenomenon, the heat exchanger surface is made hydrophilic to prevent the formation of bridges due to water droplets.

As a method for hydrophilizing the surface of the fin for a heat exchanger, an aluminum plate is formed and processed to form an aluminum fin, which is assembled, then subjected to a chromate treatment, and a surface treatment agent is immersed in the fin and sprayed. In general, a method of applying by means such as a shower or the like is performed. The following are examples of the hydrophilic surface treatment agent treated by these methods. A method of applying water glass (for example, see JP-A-59-13)
078, etc.). A method of applying a solution mainly composed of an organic polymer resin such as a water-soluble polyamide resin to form a resin film (for example, disclosed in JP-A-61-250495).

[0004] Recently, as a measure to prevent unpleasant odors and the scattering of microorganisms at the start of heat exchanger operation due to microorganisms generated on the fin surface, a resin-based treating agent (for example, Japanese Unexamined Patent Publication No. 4-366396, etc.) has also been proposed.

[0005]

However, the fin treated by the above-mentioned method becomes powdery on the surface of the treated film with the passage of time, and this powdery material is scattered when ventilated, resulting in a bad smell of cement or chemical. appear. In addition, water glass is hydrolyzed by coagulated water generated during operation of the heat exchanger,
Since the fin surface becomes alkaline, corrosion is likely to occur, and there is also a problem in terms of environmental conservation because aluminum hydroxide powder, which is a corrosion product, is scattered.

On the other hand, the fins treated by the above method do not have sufficient water resistance of the coating, and the coating is easily dissolved by the coagulated water. Therefore, there are problems such as the persistence of hydrophilicity on the fin surface and the deterioration of corrosion resistance. In addition, there is a problem that the cost is high.

In recent years, air conditioners have been reduced in size and weight, and heat exchangers have been designed to be compact, so that the spacing between fins has been narrowed. Therefore, higher hydrophilicity has been required, and the contact angle with water has been 25 °. It is desired that:

Further, recently, since a comfortable living space is required, generation of odor by an air conditioner has been regarded as a problem. The conventional method proposed as a measure against the smell of the coating film at the beginning of use and the unpleasant odor at the start of operation due to the microorganisms generated in the air conditioner is still insufficient, and its improvement is required.

[0009] As described above, the method currently in practical use does not sufficiently satisfy such demands, and is more excellent in hydrophilicity and corrosion resistance, has no odor problem, and has excellent durability. Development of fins is desired.

[0010]

Means for Solving the Problems The present inventors have conducted intensive studies with the aim of solving the above problems, and as a result, have found that
By applying an antibacterial composition mainly composed of an antibacterial resin having both fungicidal properties and hydrophilicity to fins for heat exchangers, it suppresses the generation of bacteria and mold for a long time and prevents the generation of unpleasant odors. By adding fine particles and roughening the surface, it becomes easier to wet with water, in addition to the inherent hydrophilicity of the antibacterial resin, it has extremely high hydrophilicity, water wettability, and
It has been found that the effect lasts for a long time, and the present invention has been completed.

That is, a first aspect of the present invention is that the composition contains a high-molecular-weight antibacterial agent and fine particles, has an elution amount of 0.2 g / m ² or less when immersed in water at 40 ° C. for 120 hours, and 25 corners
The antibacterial composition for fin lamination for heat exchangers, wherein the contact angle of water after immersion in water at 40 ° C for 120 hours is 25 ° or less.

A second feature of the present invention is that the high-molecular antibacterial agent is a copolymer having at least one of an ammonium base, a phosphonium base and a sulfonium base in a main chain and / or a side chain. An antimicrobial composition for laminating fins for a heat exchanger according to the first invention.

[0013] A third aspect of the present invention is a fin for a heat exchanger, which is obtained by laminating the antibacterial composition according to the first aspect.

[0014] A fourth aspect of the present invention is a fin for a heat exchanger, which is obtained by laminating the antibacterial composition according to the second aspect.

The antibacterial composition and the fin for a heat exchanger of the present invention will be described below.

The antibacterial composition of the present invention comprises an antibacterial resin and fine particles.

The antibacterial resin in the present invention is a resin containing a high-molecular antibacterial agent. The polymer antibacterial agent is a polymer compound in which an organic antibacterial agent component is bonded to a main chain or a side chain. Although some organic antibacterial agents have relatively high antibacterial and antifungal properties, they are generally easily eluted and do not last long. Thus, by bonding an organic antibacterial agent component to the main chain or side chain of the polymer compound, antibacterial and antifungal properties can be maintained for a long time.

The organic antibacterial agent is a general term for natural extracts, low molecular weight organic compounds, and polymers having antibacterial properties, and generally contains elements such as nitrogen, sulfur, and phosphorus. For example,
Natural antibacterial agents include chitin, chitosan, wasabi extract, mustard extract, hinokitiol, tea extract, etc., and low-molecular-weight organic compounds include allyl isothiocyanate,
Quaternary ammonium salts such as polyoxyalkylenetrialkylammonium, benzalkonium chloride, hexamethylene biguanide hydrochloride, organic silicon quaternary ammonium salts, tri-n-butylhexadecylphosphonium chloride, tri-n-butyl Quaternary phosphonium salts such as tetradecylphosphonium chloride and tri-n-butylhexadecylphosphonium chloride, phenylamides, biguanides, tetraalkylphosphonium sulfoisophthalate or diesters thereof, imidazole / thiazole compounds, thiocarbides Compounds, pyridine / quinoline-based compounds, and the like, but are not limited thereto.

Among these organic antibacterial agents, onium salts such as ammonium bases, phosphonium bases and sulfonium bases, and antibacterial active groups such as phenylamide group and biguanide group are mainly used because of easy binding to a polymer substance. A polymer bonded to a chain or a side chain is preferred, and a phosphonium salt-based compound having high antibacterial activity and a broad antibacterial spectrum is particularly preferred.

The antibacterial resin in the present invention needs to contain a hydrophilic substance. By containing a hydrophilic substance, the antibacterial resin can be given hydrophilicity, and the antibacterial performance can be significantly improved. However, if a hydrophilic substance is simply mixed with the polyester resin, the hydrophilic substance gradually elutes during use, and the hydrophilicity of the antibacterial resin decreases. Therefore, it is necessary to copolymerize a hydrophilic substance with the antibacterial resin or to chemically bond the antibacterial resin with a curing agent or the like. Thereby, the elution of the hydrophilic substance can be suppressed, and the hydrophilicity can be prevented from decreasing with time.

The hydrophilic substance in the present invention is a substance having an excellent affinity for water, and is a substance which can be dissolved, dispersed or water-retaining, moisturizing and swellable in water. Generally, a hydrophilic group such as an amino group, an amide group, a carboxyl group or an alkali metal salt thereof, a sulfonic acid group or an alkali metal salt thereof, or a derivative thereof, or an ether bond is contained in one molecule.
An organic compound or a polymer compound containing at least one of these. Specific examples thereof include polyvinyl alcohol, starch, a homopolymer or copolymer of polyacrylic acid, a homopolymer or copolymer of polymethacrylic acid, and a homopolymer or copolymer of maleic anhydride (for example, maleic anhydride. Styrene copolymer), polyvinyl sulfonic acid or its copolymer or an alkali metal salt thereof, polyalkylene glycol such as polyethylene glycol (also known as polyethylene oxide) polypropylene glycol, polyethylene propylene glycol, polytetramethylene glycol, glycerin, polyglycerin Such as polyols or polymers thereof, glycerin, polyglycerin,
Examples of the water-soluble modified cellulose include hydroxyethyl cellulose, methyl cellulose, methyl hydroxypropyl cellulose, sodium carboxycellulose, cellulose nitrate carboxyl methyl ether and the like.

As the antibacterial resin satisfying the above requirements, a phosphonium base of a sulfonic acid group-containing aromatic dicarboxylic acid having a dicarboxylic acid component and a glycol component as main constituents and represented by the above general formula (1) is particularly preferred. A copolymer of a polyester resin and a hydrophilic substance is particularly desirable.
By copolymerizing the polyester resin with a hydrophilic substance, not only the hydrophilicity of the antibacterial resin is increased but also the antibacterial property is remarkably increased, and the effects of the hydrophilicity and the antibacterial and antifungal properties are maintained for a long time. preferable. Further, the fin material coated on the surface with the antimicrobial composition containing the antimicrobial resin as a main component has a small amount of the antimicrobial composition eluted, and has excellent hydrophilicity and corrosion resistance over a long period of time without a problem of odor, Ideal for heat exchanger fins.

[0023]

Embedded image (Where A is an aromatic group, X1 and X2 are ester-forming functional groups, R1, R2, R3 and R4 are alkyl groups, at least one of which is an alkyl group having 10 to 20 carbon atoms)

In the polyester resin having a phosphonium group of a sulfonic group-containing aromatic dicarboxylic acid of the present invention, a preferred embodiment is a phosphonium group of a sulfonic group-containing aromatic dicarboxylic acid represented by the above general formula (1). Is a polyester resin obtained by copolymerizing 1 to 50 mol% with respect to the total acid component, and more preferably a polyester resin obtained by copolymerizing the phosphonium base of the sulfonic acid group-containing aromatic dicarboxylic acid with 3 to 20 mol% based on the total acid component. It is.

A polyester resin in which the phosphonium base of a sulfonic acid group-containing aromatic dicarboxylic acid is copolymerized in an amount of not more than 1 mol% with respect to all the acid components does not easily provide antibacterial and antifungal properties. Further, when an attempt is made to copolymerize the phosphonium base of the sulfonic acid group-containing aromatic dicarboxylic acid in an amount of 50 mol% or more with respect to the total acid components, gelation occurs during the polymerization of the polyester and polymerization cannot be performed.

The dicarboxylic acid component used in the polyester resin in the present invention includes terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid and the like. . Further, an alicyclic dicarboxylic acid, an aliphatic dicarboxylic acid, a heterocyclic dicarboxylic acid, or the like may be used in combination within a range not to impair the content of the invention. 1,2-cyclohexanedicarboxylic acid as the alicyclic dicarboxylic acid,
Examples thereof include 1,3-cyclohexanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid. Examples of the aliphatic dicarboxylic acid include succinic acid, glutaric acid, adipic acid, sebacic acid, dodecanedicarboxylic acid, azelaic acid, eicoic acid, dimer acid and derivatives thereof. Heterocyclic dicarboxylic acids include pyridine carboxylic acid and its derivatives. Further, an oxycarboxylic acid such as p-oxybenzoic acid and a polyvalent carboxylic acid such as trimellitic anhydride and pyromellitic anhydride may be used in combination as long as the content of the invention is not impaired.

The dicarboxylic acid component contains 70 mol% of aromatic dicarboxylic acid from the viewpoint of practical durability when formed into a coating film.
It is preferable to include the above. As other dicarboxylic acids, 1,4-dicarboxylic acid, adipic acid and sebacic acid are particularly preferred.

As the glycol component, ethylene glycol, propylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,4-
Butanediol, 1,5-pentadiol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 2-methyl-1,5-pentanediol, 2,2-diethyl-1 Alkylene glycols such as 1,3-propanediol, 1,9-nonanediol and 1,10-decanediol, alicyclic glycols such as 1,2-cyclohexanedimethanol, alkylene oxide adducts of bisphenol A or F, diethylene glycol, Examples include polyethylene glycol, neopentyl glycol of hydroxypivalic acid (HPN), polypropylene glycol, polytetramethylene glycol, and the like. In addition, a small amount of a compound containing an amide bond, a urethane bond, an ether bond, or a carbonate bond may be contained.

Among the glycol components, ethylene glycol, neopentyl glycol, 2-methyl-1,3-propanediol, 1,6-hexanediol, and ethylene glycol, neopentyl glycol, and 1,6-hexanediol are more preferable than the practical durability when formed into a coating film. , 5-
Pentanediol, 3-methyl-1,5-pentanediol, and 1,4-cyclohexanedimethanol. Further, a polyhydric polyol such as trimethylolethane, trimethylolpropane, glycerin, pentaerythritol and the like may be used in combination as long as the content of the invention is not impaired.

Examples of the phosphonium salt of a sulfonic acid group-containing aromatic dicarboxylic acid include tri-n-sulfoisophthalic acid.
Butyldecylphosphonium salt, tri-n-butyloctadecylphosphonium sulfoisophthalate, tri-n-butyloctadecylphosphonium sulfoisophthalate,
Tri-n-butyloctadecylphosphonium sulfoisophthalate, tri-n-butylhexadecylphosphonium sulfoisophthalate, tri-n sulfoisophthalate
-Butyltetradecylphosphonium salt, sulfoisophthalic acid-n-butyldodecylphosphonium salt, 4-sulfonaphthalene-2,7-dicarboxylic acid tri-n-butyldecylphosphonium salt, 4-sulfonaphthalene-2,7-
Tri-n-butyloctadecylphosphonium dicarboxylate, tri-n-butylhexadecylphosphonium 4-sulfonaphthalene-2,7-dicarboxylate, tri-n-butyltetradecyl 4-sulfonaphthalene-2,7-dicarboxylate Phosphonium salt, 4-sulfonaphthalene-
Tri-n-butyldodecylphosphonium salt of 2,7-dicarboxylic acid, etc., and tri-n-butylhexadecylphosphonium sulfoisophthalate and tri-n-butyltetradecylphosphonium sulfoisophthalate from the viewpoint of antibacterial activity. And tri-n-butyldodecylphosphonium sulfoisophthalate are particularly preferred.

The above-mentioned phosphonium salts of aromatic dicarboxylic acids include sulfo-aromatic dicarboxylic acids or their sodium, potassium, ammonium salts and the like, as well as tri-n-butylhexadecylphosphonium bromide, tri-n-butyltetradecylphosphonium bromide and tri-n-butyltetradecylphosphonium bromide. It can be obtained by reacting a phosphonium salt such as n-butyldodecylphosphonium bromide. The reaction solvent at this time is not particularly limited, but water is most preferable.

The method for producing the polyester is not particularly limited, but a so-called direct polymerization method in which an oligomer obtained by directly reacting a dicarboxylic acid and a glycol is polycondensed,
A so-called transesterification method in which a dimethyl ester of a dicarboxylic acid and a glycol are subjected to transesterification and then polycondensation, and the like, may be used, and an arbitrary production method can be applied.

The antimicrobial resin of the present invention needs to contain a hydrophilic substance in the polyester resin containing a phosphonium base. In particular, it is preferable to copolymerize a hydrophilic substance with a polyester resin containing a phosphonium base. By copolymerizing a hydrophilic substance, hydrophilicity can be imparted to the polyester resin, and the antibacterial and antifungal properties are remarkably improved. By simply mixing a hydrophilic substance with the polyester resin, the hydrophilic substance gradually elutes during use, and the hydrophilicity of the antibacterial resin decreases. By copolymerizing a hydrophilic substance with the polyester resin,
Elution of a hydrophilic substance can be suppressed, and a decrease in hydrophilicity over time can be prevented.

The method of copolymerizing these hydrophilic groups with the polyester resin includes 5-sulfoisophthalic acid,
A metal salt such as sulfonaphthalene-2,7-dicarboxylic acid, 5 (4-sulfophenoxy) isophthalic acid or 2-
Sulfo-1,4-butanediol, 2,5-dimethyl-
A method of copolymerizing a dicarboxylic acid or glycol containing a sulfonic acid metal base such as a metal salt such as 3-sulfo-2,5-hexanediol with a polyester resin, an alkylene glycol such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. And a method of graft-polymerizing a vinyl-based monomer containing a hydrophilic group onto the polyester resin.

The vinyl monomer having a hydrophilic group that can be grafted onto the polyester resin in the present invention includes those containing a carboxyl group, a hydroxyl group, a sulfonic acid group, an amide group, etc., and can be changed to a hydrophilic group. Examples of groups that can be formed include those containing an acid anhydride group, a glycidyl group, a chloro group, and the like. Among them, those having a carboxyl group are most preferred. For example, monomers containing a carboxyl group or a salt thereof such as acrylic acid, methacrylic acid and salts thereof, and alkyl acrylates such as methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate and t-butyl acrylate , Alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, and t-butyl methacrylate; hydroxy-containing monomers such as 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate; acrylamide; N-methylacrylamide;
Amide group-containing monomers such as methyl methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, N-methoxymethyl acrylamide, N-methoxymethyl methacrylamide, N, N dimethylol acrylamide, N-phenylacrylamide, glycidyl acrylate, glycidyl Epoxy-containing monomers such as methacrylate are exemplified.

Other monomers having a hydrophilic group include, for example, monomers containing an epoxy group such as allyl glycidyl ether; monomers containing a sulfonic acid group or a salt thereof such as styrene sulfonic acid, vinyl sulfonic acid and salts thereof; Examples include monomers containing a carboxyl group or a salt thereof, such as crotonic acid, itaconic acid, maleic acid, fumaric acid, and salts thereof, and monomers containing an acid anhydride, such as maleic anhydride and itaconic anhydride. These can be used in combination with other monomers. Other monomers include, for example, vinyl isocyanate, allyl isocyanate, styrene, vinyl methyl ether, vinyl ethyl ether, acrylonitrile, methacrylonitrile, vinylidene chloride, vinyl acetate, vinyl chloride, and the like. Copolymerization can be performed using the type.

The ratio of the monomer having a hydrophilic group to the other monomer is preferably in the range of 30/70 to 100/0 in molar ratio. When the ratio of the monomer having a hydrophilic group is 3
If it is less than 0 mol%, the effect of increasing the hydrophilicity of the entire antibacterial resin is not sufficiently exhibited.

As a method for grafting a monomer containing a hydrophilic group to the polyester, a known graft polymerization method can be used. The following method is mentioned as a typical example. For example, a radical polymerization method in which radicals are generated in a main chain polymer substance by light, heat, radiation, or the like, and then the monomers are graft-polymerized, or AlCl is used.
3. There are a cation polymerization method in which cations are generated using a catalyst such as TiCl4, and an anion polymerization method in which anions are generated using metal Na, metal Li, or the like.

Further, there is a method in which a polymerizable unsaturated double bond is previously introduced into a polymer material of the main chain, and a vinyl monomer is reacted with the polymerizable unsaturated double bond. Examples of the monomer having a polymerizable unsaturated double bond used therein include fumaric acid, maleic acid, maleic anhydride, tetrahydromaleic anhydride and the like. The most preferred of these are fumaric acid, maleic acid, and 2,5-norbornene dicarboxylic acid.

Further, there is a method in which a main chain high molecular substance having a functional group introduced into a side chain is reacted with a branch polymer having a group which reacts with the above functional group at the terminal. For example the side chain -OH group, -SH group, -NH ₂ group, -COOH group, -C
A polymer having a hydrogen donating group such as an ONH ₂ group, and one end having an —N ＝ C ＝ O group, a —C ＝ C ＝ O group, and the following general formula (Formula 2)
A method of reacting with a vinyl copolymer which is a hydrogen accepting group such as a functional group represented by the following formula, or a method of reacting in the reverse combination.

[0041]

Embedded image

The preferred weight ratio of the polyester as the main chain of the present invention to the vinyl monomer to be grafted is 99 /
It is in the range of 1 to 30/70. More preferably 95 /
5/50/50, most preferably 85 / 15-6.
It is in the range of 5/35. When the weight ratio of the polyester resin in the main chain is less than 30%, the graft polymerizable vinyl monomer remains completely unreacted, and the properties of the conventional polymer such as heat resistance, processability, and water resistance are impaired. . When the weight ratio of the polyester resin in the main chain exceeds 99%, the hydrophilicity of the whole antibacterial resin cannot be obtained.

In the present invention, in order to prevent the hydrophilicity from decreasing over time, it is preferable to incorporate a curing agent capable of reacting with either the polyester resin or the hydrophilic substance in the antibacterial resin. Examples of the curing agent include an oxazoline group-containing resin, an alkyl etherified aminoformaldehyde resin, an epoxy compound and an isocyanate compound. The addition of the curing agent has the advantage that changes in water contact angle and water leakage are reduced even under more severe conditions than the water resistance evaluation in the present invention.

The alkyl etherified aminoformaldehyde resin is, for example, formaldehyde or paraformaldehyde alkyl etherified with an alcohol having 1 to 4 carbon atoms such as methanol, ethanol, n-propanol, isopropanol and n-butanol. , N, N-ethylene urea, dicyandiamide, aminotriazine, and the like; methoxylated methylol benzoguanamine, methoxylated methylol-N, N-ethylene urea, methoxylated methylol dicyandiamide, methoxylated methylol melamine, butoxylated methylol Melamine, butoxylated methylol benzoguanamine, methoxylated / butoxylated mixed type methylol melamine, etc., are preferred. Melamine, butoxy methylol melamine, or a methoxylated / butoxylated mixed melamine, may be used alone or in combination.

Examples of the epoxy compound include diglycidyl ether of bisphenol A and oligomers thereof, diglycidyl ether of hydrogenated bisphenol A and oligomers thereof, diglycidyl orthoisophthalate, diglycidyl isophthalate, diglycidyl terephthalate, p -Diglycidyl oxybenzoate, diglycidyl tetrahydrophthalate,
Diglycidyl hexahydrophthalate, diglycidyl succinate, diglycidyl adipate, diglycidyl sebacate, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1, 6-hexanediol diglycidyl ether and polyalkylene glycol diglycidyl ethers, triglycidyl trimellitate, triglycidyl isocyanurate, 1,4-diglycidyloxybenzene, diglycidyl propylene urea, glycerol triglycidyl ether, trimethylol ethane Trig of triglycidyl ether, pentaerythritol tetraglycidyl ether, glycerol alkylene oxide adduct It can be mentioned glycidyl ethers.

Further, as the isocyanate compound, there are aromatic and aliphatic diisocyanates and trivalent or higher polyisocyanates, and either low molecular weight compounds or high molecular weight compounds may be used. For example, tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate or trimers of these isocyanate compounds, and excess of these isocyanate compounds The amount and, for example, ethylene glycol, propylene glycol, trimethylolpropane, glycerin, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, low molecular active hydrogen compounds such as triethanolamine or various polyester polyols, polyether polyols, polyamides By reacting with a high molecular weight active hydrogen compound, etc. Terminal isocyanate group-containing compounds, and the like to be. The isocyanate compound may be a blocked isocyanate.
Examples of the isocyanate blocking agent include phenols such as phenol, thiophenol, methylthiophenol, ethylthiophenol, cresol, xylenol, resorcinol, nitrophenol, chlorophenol, acetoxime, methylethylketoxime, oximes such as cyclohexanone oxime, methanol, Alcohols such as ethanol, propanol and butanol; halogen-substituted alcohols such as ethylene chlorohydrin and 1,3-dichloro-2-propanol;
Tertiary alcohols such as t-butanol and t-pentanol, ε-caprolactam, δ-valerolactam, γ
-Butyrolactam, lactams such as β-propyrolactam, and other active amines such as aromatic amines, imide rings, acetylacetone, acetoacetate, and malonic acid ethyl ester, mercaptans, imines, and urea. And diaryl compounds such as sodium bisulfite. The blocked isocyanate can be obtained by subjecting the above isocyanate compound to an isocyanate blocking agent to undergo an addition reaction by a known appropriate method.

Further, these crosslinking agents may be used in combination with known curing agents or accelerators selected according to their types.

The fine particles used in the present invention may be either organic particles or inorganic particles.
It is preferably from 5 to 10 μm. When the average particle diameter of the fine particles is 0.05 μm or less, the surface of the coating film is insufficiently roughened, and the hydrophilicity is not well exhibited. On the other hand, when the average particle diameter of the fine particles is 10 μm or more, the dispersibility of the particles deteriorates, and a good coating film cannot be formed.

In the present invention, the added amount of the fine particles is preferably at least 10% by weight based on the antibacterial composition. If the addition amount is 10% by weight or less, the surface of the coating film is insufficiently roughened, and the hydrophilicity is not well exhibited. The upper limit of the addition amount is not specified because it greatly varies depending on the density of the fine particles. However, if the addition amount of the fine particles is too large, the surface hardness of the coating film becomes extremely weak, which is not preferable.

The organic particles include cellulose particles, sodium acrylate polymer particles, sodium acrylate-acrylamide copolymer particles, acrylic acid-vinyl alcohol copolymer particles, and vinyl acetate-methyl acrylate copolymer. Representative examples include saponified particles, starch-polyacrylonitrile hydrolyzed particles, and starch-polyacrylate crosslinked particles.

Representative examples of the inorganic particles include particles of silica, alumina, titanium oxide, zirconium oxide, iron oxide, chromium oxide, calcium carbonate, calcium phosphate, calcium sulfate, magnesium carbonate, barium sulfate, and the like. Some inorganic particles have a very small primary particle diameter, but can be used when the secondary particle diameter falls within the above range.

The method of applying the antimicrobial composition of the present invention to fins for heat exchangers is carried out by appropriately adjusting the composition to a concentration suitable for application, using conventional coating methods such as dip coating, shower coating, spray coating, and roll coating. It is performed by applying to a heat exchanger fin molded by painting or the like, and then heating and drying.

Among the above-mentioned coating methods, dip coating is particularly preferred. When coating is performed by such dip coating,
An aqueous bath in which the solid concentration of the antibacterial composition is adjusted to a range of usually 2 to 30% by weight, preferably 5 to 10% by weight, is immersed in the bath with the preformed and assembled fins for heat exchanger. After raising, baking can be performed by baking at appropriate baking conditions, for example, at 100 to 180 ° C. for 1 to 10 minutes.

In the present invention, the application of the antibacterial composition forms a practical hydrophilic film even if it is applied to a fin for a heat exchanger that has been subjected to only degreasing and washing. It is preferable to apply a phosphoric acid chromate treatment or a chromate chromate treatment, which is a conventionally known surface treatment for aluminum, to the fin for application before applying it, since a coating having excellent corrosion resistance is formed.

The antibacterial coating thus formed is
The thickness is in the range of 0.2 to 5 μm, preferably 0.5 to 3 μm. When the film thickness is less than 0.2 μm, the hydrophilicity and antibacterial properties are insufficiently maintained, and when it exceeds 5 μm, the heat radiation efficiency of the heat exchanger fins may be reduced.

[0056]

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

The antibacterial preparations obtained in Examples and Comparative Examples are described below.
The method for measuring the physical properties of a metal plate having antifungal properties will be described.

1. Antibacterial test E. coli diluted with 1/50 broth 0.1 ml of a Coil (Escherichia coli) bacterial solution (concentration: 105 cells / ml) was dropped onto a 5 cm × 5 cm sample metal plate that had been sterilized with high pressure steam in advance, and the sample metal plate was subjected to high pressure steam sterilization. A polyethylene film was adhered. The test piece was transferred to a sterile petri dish and cultured at 37 ° C. for 24 hours. Then, the bacteria on the film were washed with 10 ml of SCDLP medium, diluted 10-fold, spread on a normal agar plate, and the number of bacteria was counted 24 hours later. The antibacterial rate was calculated by the following equation. Antibacterial rate = (1−number of bacteria measured / initial bacteria) × 100

2. Mold resistance test In accordance with JIS Z 2911 6.2.2, a 5 cm x 5 cm sample metal plate was stuck on a flat plate of an inorganic salt agar medium, and applied to a spore suspension of the following five mold strains: Spray 0.2 ml of the mixture containing 5% sucrose and add
After culturing at 1 ° C. for 28 days, the growth state of the mold was evaluated. (Test strain) Aspergillus niger ATCC 62
75 Penicillium citrinum ATCC
9849 Chaetomium globosum ATCC
6205 Rhizopus stolonifer ATCC
10404 Aureobasidium pullulans I
FO 6353 (mold resistance display) (1) Mold growth is 1/3 or more of sample area (2) Mold growth is within 1/3 of sample area (3) Mold growth is not recognized

3. Water Contact Angle Measurement The water contact angle of the coating film of the sample was measured at 25 ° C. and 50% relative humidity using a contact angle meter CA-X manufactured by Kyowa Science Co., Ltd.

4. Water wettability test Judgment was made based on the state of adhesion of water to the sample metal plate by spraying. ◎ indicates repelling water within 10% of the surface area, Δ indicates repelling water within 50%, and × indicates repelling water of 50% or more of the surface area. In practice, Δ is required, and ◎ is preferred.

[0062] 5. Odor prevention test The odor after the sample metal plate was left in a constant temperature and humidity oven at a temperature of 30 ° C and a relative humidity of 90% for 2 weeks was evaluated. ◎ indicates no odor, ○ indicates little odor, Δ indicates slightly odor, and X indicates a state where odor is clearly felt. In practice, Δ is required, and ◎ is preferred.

6. Water Resistance Test A sample metal plate was immersed in distilled water controlled at 40 ° C. ± 1 ° C. for 120 hours, taken out, dried at room temperature, and evaluated.

7. Elution Resistance Test The sample metal plate was immersed in distilled water controlled at 40 ° C. ± 1 ° C. for 120 hours, taken out, dried at room temperature, and the weight change before and after the water resistance test was measured.

(Production Example 1 of Polyester Resin) Stirrer,
Dimethyl terephthalate 515 in a stainless steel autoclave equipped with a thermometer and a partial reflux condenser
Parts, dimethyl isophthalate 360 parts, 5-sulfodimethylisophthalic acid tri-n-butyldodecylphosphonium salt 161 parts, ethylene glycol 450 parts, neopentyl glycol 450 parts, and tetra-n-butyl titanate 0.52 parts, The transesterification reaction was performed for 4 hours from 160 to 220 ° C. Then fumaric acid 2
9 parts were added, the temperature was raised to 200 to 220 ° C. over 1 hour, and the reaction system was gradually decompressed, and then reacted under a reduced pressure of 0.2 mmHg for 2 hours to obtain a polyester (A-1). The composition of the polyester is as shown in Table 1.

[0066]

[Table 1]

The polyesters (A-2, A-3, A-4) shown in Table 1 were produced in the same manner.

(Production Example 1 of Aqueous Dispersion of Graft Polymer) 300 parts of polyester (A-1), 360 parts of methyl ethyl ketone, 120 parts of isopropyl alcohol were placed in a reactor equipped with a stirrer, a thermometer, a reflux device and a fixed-rate dropping device. It was placed,
The resin was heated and stirred to dissolve the resin under reflux. After the resin is completely dissolved, 60 parts of acrylic acid and 40 parts of ethyl acrylate
Parts, a mixture of 1.5 parts of octyl mercaptan, 6 parts of azobisisobutyronitrile, and 90 parts of methyl ethyl ketone.
And a solution dissolved in a mixture of 30 parts of isopropyl alcohol were added dropwise to the polyester solution over 2 hours, and the mixture was further reacted for 3 hours to obtain a graft polymer solution. Then, after cooling the graft polymer solution to room temperature, 56 parts of triethylamine was added and neutralized, and then 800 parts of ion-exchanged water was added and stirred for 30 minutes. Thereafter, the solvent remaining in the solvent was distilled off by heating to obtain an aqueous graft polymer dispersion (B-1). The polyester (A-2, A-3) was graft-polymerized by the same method to obtain a graft polymer aqueous dispersion (B-2, B-3).

(Production Example of Polyester Aqueous Dispersion) A reactor equipped with a stirrer, a thermometer, a reflux device and a fixed-rate dropping device was charged with 300 parts of polyester (A-4), 360 parts of methyl ethyl ketone, and 120 parts of isopropyl alcohol. The resin was heated and stirred to dissolve the resin under reflux. Then, the polyester solution was cooled to room temperature, and then deionized water 80
0 parts were added and stirred for 30 minutes. Thereafter, the solvent remaining in the solvent is distilled off by heating, and the aqueous polyester dispersion (B-
4) was obtained.

(Production Example 2 of Aqueous Dispersion of Graft Polymer) In a reactor equipped with a stirrer, a thermometer, a reflux device and a metering device, 100 parts of polyester (A-1), 360 parts of methyl ethyl ketone, 120 parts of isopropyl alcohol It was placed,
The resin was heated and stirred to dissolve the resin under reflux. After the resin has completely dissolved, 180 parts of acrylic acid and 1 part of ethyl acrylate
A solution prepared by dissolving a mixture of 20 parts, 4.5 parts of octyl mercaptan and 18 parts of azobisisobutyronitrile in a mixture of 270 parts of methyl ethyl ketone and 90 parts of isopropyl alcohol was dropped into the polyester solution over 2 hours. The reaction was further performed for 3 hours to obtain a graft polymer solution. Then, after cooling the graft polymer solution to room temperature, 150 parts of triethylamine was added and neutralized, and then 800 parts of ion-exchanged water was added and stirred for 30 minutes. Thereafter, the solvent remaining in the solvent was distilled off by heating to obtain an aqueous graft polymer dispersion (B-5).

Example 1 Graft polymer aqueous dispersion (B-1) was treated with water at a solid content of 10%.
Oxazoline based on 100 parts of diluted solution
Crosslinking agent (Nippon Shokubai Co., Ltd., Epocros, solid content 40%) 2
Part, silica fine particles (Aeroji manufactured by Nippon Aerosil Co., Ltd.)
5) and stirring until the silica fine particles are sufficiently dispersed.
Stirred. Preliminary on 0.2mm thick aluminum alloy plate
Coating-type chromate treatment to form an inorganic corrosion-resistant coating with a coating amount of 1
0mg / m ^TwoCoat liquid on a metal plate coated to
With a solid content of 1 g / m by dip coating^TwoBecomes
And then heat treated at 150 ° C for 5 minutes
A plate was made. Table 2 shows the characteristics of this resin laminated metal plate.
Was. Antibacterial and antibacterial properties before and after elution resistance and water resistance test
Viability, water contact angle, water wettability, odor prevention, all good
Was.

Example 2 In the same manner as in Example 1, except that the aqueous graft polymer dispersion (B-2) was used in place of the aqueous graft polymer dispersion (B-1). A resin laminated metal sheet having a coating film on the surface layer was produced. Table 2 shows the characteristics of the resin laminated metal plate. Antibacterial property, antifungal property, water contact angle, water wettability, odor prevention property before and after elution resistance and water resistance test,
Everything was good.

Comparative Example 1 The procedure of Example 1 was repeated, except that the aqueous graft polymer dispersion (B-3) was used in place of the aqueous graft polymer dispersion (B-1). A resin laminated metal sheet having a coating film on the surface layer was produced. Table 2 shows the characteristics of the resin laminated metal plate. Since the resin does not contain an antibacterial component, it has no antibacterial and antifungal properties, and has no odor preventing property.

Comparative Example 2 A surface layer was formed in the same manner as in Example 1 except that an aqueous dispersion of polyester (B-4) was used instead of the aqueous dispersion of graft polymer (B-1). A resin laminated metal sheet having a coating film was produced. Table 2 shows the characteristics of the resin laminated metal plate. Since the resin does not contain a hydrophilic component, the water contact angle and water wettability are poor. Also, the antibacterial properties are significantly reduced.

Comparative Example 3 An oxazoline-based crosslinking agent (Epocross, 40% solids, manufactured by Nippon Shokubai Co., Ltd.) was added to 100 parts of the aqueous polyester dispersion (B-4) diluted with water to a solid content of 10%. Department,
Silica fine particles (Aerosil manufactured by Nippon Aerosil Co., Ltd.)
5 parts, polyacrylic acid aqueous solution (weight average molecular weight 500
(0, solid content: 50%) and stirred until the silica fine particles were sufficiently dispersed. The coating solution was applied by dip coating to a 0.2 mm-thick aluminum alloy plate, which was previously coated with a chromate treatment to form an inorganic corrosion-resistant coating on the metal plate so that the coating amount was 10 mg / m ² . After application so that the application amount was 1 g / m ² , heat treatment was performed at 150 ° C. for 5 minutes to produce a resin laminated metal sheet. Table 2 shows the characteristics of the resin laminated metal plate. Since only the hydrophilic component was blended, there was no water resistance, and almost all of the coating layer was removed in the elution resistance test.

Comparative Example 4 The procedure of Example 1 was repeated, except that the aqueous graft polymer dispersion (B-5) was used in place of the aqueous graft polymer dispersion (B-1). A resin laminated metal sheet having a coating film on the surface layer was produced. Table 2 shows the characteristics of the resin laminated metal plate. Since the grafting amount of the hydrophilic component was too large, there was no water resistance, and almost all of the coating layer was removed in the elution resistance test.

COMPARATIVE EXAMPLE 5 An inorganic corrosion-resistant film having a coating amount of 10 mg / mm was applied on an aluminum alloy plate having a thickness of 0.2 mm in advance by a coating type chromate treatment.
An aqueous graft polymer dispersion (B-1) was diluted with water to a solid content of 10% on a metal plate coated so as to have a m ² thickness,
2 parts of an oxazoline cross-linking agent (Nippon Shokubai Co., Ltd., solid content 40%) was added, and a sufficiently stirred liquid was applied by dip coating so that the applied amount of the solid content was 1 g / m ^2, and then at 150 ° C. for 5 minutes. Heat treatment was performed to produce a resin laminated metal plate. Table 2 shows the characteristics of the resin laminated metal plate. Unless fine particles are added, the water contact angle and water wettability are poor.

[0078]

[Table 2]

[0079]

The antibacterial composition of the present invention is excellent in antibacterial and antifungal properties, hydrophilicity and durability, and the fin material coated with the antibacterial composition for a long period of time It is ideal for heat exchanger fins because it suppresses the generation of bacteria and mold and has no odor problem.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shigetsugu Konagaya 2-1-1 Katata, Otsu-shi, Shiga F-term in Toyobo Co., Ltd. Research Laboratory 4D075 CA37 CA45 DC16 EB31 EB35 4F100 AA20H AB10 AB31 AL01A AL01B BA02 CA12A CA12B DE01A DE01B EH46 EJ69 GB90 JB05 JC00 JL00 4H011 AA02 AA03 BA02 BB04 BB07 BB17 BB19 BC03 BC19 DA17 DD07 DE15 DH02 DH04 DH19 DH25 4J038 BA021 BA091 BA111 GA02 CR071 GA031 NA00 NA03 NA06 PB06

Claims (4)

[Claims] 1. A composition comprising a polymer antibacterial agent and fine particles,
Leaching amount of 0.2 g / m when immersed in water at 120 ° C for 120 hours
² is an antimicrobial composition having a water contact angle of 25 ° or less, and a water contact angle of 25 ° or less after immersion in water at 40 ° C. for 120 hours. Antimicrobial composition for container fin lamination. 2. The heat exchange, wherein the polymer antibacterial agent according to claim 1 is a copolymer having at least one of an ammonium base, a phosphonium base and a sulfonium base in a main chain and / or a side chain. Antimicrobial composition for container fin lamination. 3. A fin for a heat exchanger comprising the antibacterial composition according to claim 1 laminated. 4. A fin for a heat exchanger comprising the antibacterial composition according to claim 2 laminated.