WO2023190471A1 - Metal microparticle-containing dispersion exhibiting antimicrobial property with excellent long-term stability - Google Patents

Metal microparticle-containing dispersion exhibiting antimicrobial property with excellent long-term stability Download PDF

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WO2023190471A1
WO2023190471A1 PCT/JP2023/012418 JP2023012418W WO2023190471A1 WO 2023190471 A1 WO2023190471 A1 WO 2023190471A1 JP 2023012418 W JP2023012418 W JP 2023012418W WO 2023190471 A1 WO2023190471 A1 WO 2023190471A1
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Prior art keywords
fine particles
dispersion
metal fine
acid
mass
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PCT/JP2023/012418
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French (fr)
Japanese (ja)
Inventor
聡太朗 簾
和彰 大橋
泰啓 小坂
章子 小金井
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東洋製罐グループホールディングス株式会社
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Priority to JP2023547056A priority Critical patent/JP7392905B1/en
Publication of WO2023190471A1 publication Critical patent/WO2023190471A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B22F1/10—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material
    • B22F1/102—Metallic powder coated with organic material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F9/00—Making metallic powder or suspensions thereof

Definitions

  • the present invention relates to a dispersion liquid containing fine metal particles coated with ascorbic acid or the like, a dispersant, and/or a binder resin and having antimicrobial properties with excellent stability over time.
  • Patent Document 1 listed below describes an antiviral composition containing monovalent copper compound fine particles, a reducing agent, and a dispersion medium, and having a pH of 6 or less.
  • Patent Document 2 describes a copper-supported oxide having an average secondary particle size of 80 nm to 600 nm, in which at least one of copper particles and copper compound particles is supported on oxide particles, and a copper-supported oxide having an average secondary particle size of 1 ⁇ m.
  • Antiviral coatings with ⁇ 15 ⁇ m barium sulfate and a water-repellent resin binder have been described.
  • metal fine particles tend to aggregate and are difficult to disperse uniformly, especially when the dispersion is used as an antiviral composition, or when coated with a binder resin for paint. When used as a coating film, it has been difficult to efficiently exhibit the antiviral properties of metal fine particles.
  • a dispersion liquid with improved dispersibility of metal fine particles the present inventors have proposed a dispersion liquid containing metal fine particles coated with a fatty acid (Patent Documents 3 and 4).
  • Patent No. 5194185 Japanese Patent Application Publication No. 2015-205998 Japanese Patent Application Publication No. 2017-128809 JP 2018-100255 Publication
  • the surface of the metal fine particles is coated with a fatty acid and/or an ester compound of the fatty acid, thereby preventing agglomeration of the metal fine particles and dispersing the metal fine particles.
  • This enables uniform dispersion in the medium.
  • fine metal particles are used in combination with a certain dispersant or binder resin for paint, it has been possible to exhibit the excellent antiviral properties of fine metal particles immediately after preparing the dispersion liquid.
  • this dispersion liquid is stored for a long period of time, a problem arises in that the effects of the metal fine particles, such as antiviral properties, cannot be obtained.
  • the present inventors conducted intensive research and found that the effect of metal fine particles disappears when the dispersant or binder resin has an acidic functional group such as a carboxyl group. It was found that this was caused by ionization of the metal fine particles due to their coexistence with acidic functional groups.
  • an object of the present invention is to effectively suppress the ionization of metal fine particles in a dispersion containing a dispersant having an acidic functional group and/or a binder resin having an acidic functional group, and to improve the antimicrobial properties of the metal fine particles.
  • This invention relates to a dispersion liquid that can stably express over a long period of time.
  • a stabilizer comprising at least one of ascorbic acid, a derivative of ascorbic acid, and a reducing polyhydric phenol, metal fine particles, and a dispersant having an acidic functional group and/or a binder having an acidic functional group
  • a dispersion liquid containing a resin and the stabilizer in an amount of 150 parts by mass or more based on 100 parts by mass of metal fine particles.
  • the metal ion concentration derived from the metal fine particles is 100 ppm or less; (2) the content of the metal fine particles is 0.001 to 10% by mass; (3) the content of the stabilizer is 0.0015 to 15% by mass; (4) the surface of the metal fine particles is coated with the stabilizer; (5) the metal fine particles are made of copper or a copper compound, or silver or a silver compound; (6) the acidic functional group of the dispersant and binder resin is a carboxyl group; (7) the binder resin is any one of acrylic resin, polyester resin, and cellulose resin; (8) the surface of the metal fine particles is further coated with fatty acid and/or fatty acid ester; is suitable.
  • the present invention also provides metal fine particles whose surfaces are coated with a stabilizer comprising at least one of ascorbic acid, an ascorbic acid derivative, and a reducing polyhydric phenol. .
  • the metal fine particles of the present invention are preferably metal fine particles made of copper or a copper compound, or silver or a silver compound.
  • an antimicrobial molded article having a coating made of the above dispersion.
  • the surface of the metal fine particles is coated with a stabilizer consisting of at least one of ascorbic acid, a derivative of ascorbic acid, and a reducing polyhydric phenol, so that acidic functional groups such as carboxyl groups
  • a stabilizer consisting of at least one of ascorbic acid, a derivative of ascorbic acid, and a reducing polyhydric phenol, so that acidic functional groups such as carboxyl groups
  • the metal fine particles can be uniformly dispersed in the dispersion without agglomerating. Even when a coating film is formed as a product, it is possible to impart excellent antimicrobial properties to the coating film.
  • antimicrobial property is a general term for antiviral property, antifungal property, antibacterial property, etc., and refers to the effect of inactivating viruses and the like.
  • a coating dispersion in which a dispersion containing a dispersant having an acidic functional group obtained in Example 1 and Comparative Examples 1, 4, and 5 was mixed with an acrylic resin emulsion having an acidic functional group as a binder resin A
  • XRD X-ray diffraction
  • Example 6 and Comparative Example 7 in which the dispersions obtained in Example 1 and Comparative Example 1 were mixed with an acrylic resin emulsion having an acidic functional group as binder resin A, immediately after preparation and It is a photograph showing changes in appearance after a day has passed.
  • the active ingredient exhibiting antimicrobial properties is metal fine particles, and the oxidizing power of active oxygen generated from these metal fine particles denatures and decomposes the proteins of microorganisms such as viruses, and the metal fine particles also denature and decompose proteins of microorganisms such as viruses. It is thought that these metal particles can denature proteins and inactivate viruses by reacting with the thiol groups of Then, over time, the metal fine particles and this acidic functional group react with each other, resulting in metal ionization, making it impossible to obtain the desired antimicrobial properties.
  • the dispersion contains a dispersant having an acidic functional group and/or a binder resin having an acidic functional group, at least one of ascorbic acid, a derivative of ascorbic acid, and a reducing polyhydric phenol is used.
  • the stabilizing agent having a reducing property is contained in an amount of 150 parts by mass or more per 100 parts by mass of metal fine particles, thereby making it possible to exhibit the effect of suppressing ionization of metal fine particles. becomes.
  • a suitable content of the stabilizer for the metal fine particles is 150 to 8000 parts by mass of the stabilizer per 100 parts by mass of the metal fine particles when the dispersion liquid contains only a dispersant having an acidic group.
  • the stabilizer can be contained in an amount of 150 to 20,000 parts by weight, preferably 200 to 17,000 parts by weight, and more preferably 200 to 15,000 parts by weight per 100 parts by weight.
  • the content of the stabilizer there is no upper limit on the content of the stabilizer as long as the excess stabilizer not used to coat the surface of the metal fine particles can be uniformly dispersed in the dispersion; It is preferable that the content of the stabilizer is 15% by mass or less, further 8% by mass or less, particularly 6% by mass or less, and this makes it possible to use water or an aqueous solvent as a dispersion medium. Even when the stabilizer is present, it is possible to uniformly disperse the stabilizer, and this is also preferable from the economic point of view. Furthermore, if the content of the stabilizer becomes excessive, the appearance of the coating film obtained by applying the dispersion or coating dispersion will be impaired, so the above range is preferable.
  • the surface of the metal fine particles is coated and protected with a reducing stabilizer, thereby suppressing the reaction between the metal fine particles and the acidic functional groups of the dispersant and/or resin binder. It becomes possible to suppress the ionization of metal particles and maintain the state of metal fine particles stably for a long period of time.
  • metal particles which are active ingredients that exhibit antimicrobial properties, include metals such as copper, silver, gold, zinc, and nickel, and compounds of these metals. Copper or silver, or a compound of these metals, which can be expressed, is preferable, and copper or a copper compound, especially copper or a monovalent copper compound, is preferable from the viewpoint of excellent antiviral properties.
  • the metal fine particles preferably have an average primary particle size in the range of 10 to 500 nm, particularly 10 to 200 nm. When the average primary particle of the metal fine particles is within the above range, it becomes possible to efficiently exhibit excellent antimicrobial performance.
  • metal fine particles with such a small average primary particle size can efficiently generate active oxygen due to their high contact rate with oxygen, and can exhibit excellent antimicrobial performance.
  • the metal fine particle powder is preferably composed of primary particles having the above-mentioned average primary particle size, and the average secondary particle size is preferably in the range of 100 nm to 500 ⁇ m, particularly 100 nm to 100 ⁇ m, so that it can be obtained in a powder state.
  • the metal fine particles can be easily dispersed in a dispersion medium, and when mixed with a binder resin to form a paint dispersion, it has excellent handling properties such as coatability.
  • the average primary particle size in this specification refers to the average of two metal particles with no gaps between them, and the average secondary particle size is the average of the metal particles with no gaps between them. Particles are particles that are packed together and are averaged. Furthermore, the primary particle size can be measured using a scanning electron microscope (SEM), and the secondary particle size can be measured using dynamic light scattering (DLS).
  • SEM scanning electron microscope
  • DLS dynamic light scattering
  • the surface of the metal fine particles used in the present invention be coated with a fatty acid and/or a fatty acid ester. This, together with being coated with the above-mentioned stabilizer, further suppresses aggregation and oxidation of the metal fine particles, making it possible to obtain excellent antimicrobial properties and dispersibility.
  • the fatty acids that coat the surface of the metal fine particles include caprylic acid, capric acid, lauric acid, myristic acid, stearic acid, oleic acid, palmitic acid, n-decanoic acid, paratoic acid, succinic acid, malonic acid, tartaric acid, malic acid, Examples include glutaric acid, adipic acid, acetic acid, etc., and combinations of a plurality of these may be used, but palmitic acid and stearic acid are particularly preferred.
  • the ester compound that coats the surface of the metal fine particles is preferably an ester compound derived from fatty acids and polyols, which are raw materials in the method for producing metal fine particle powder of the present invention, which will be described later.
  • the metal fine particles are preferably contained in the dispersion in an amount of 0.001 to 10% by weight, preferably 0.002 to 5% by weight, particularly 0.05 to 1% by weight. Furthermore, as mentioned above, in the dispersion of the present invention, the ionization of the metal fine particles due to the reaction between the metal fine particles and the acidic functional group of the dispersant and/or the binder resin is suppressed. The metal ion concentration is reduced to 100 ppm or less, particularly 60 ppm or less.
  • the stabilizer used in the present invention is a stabilizer composed of at least one of ascorbic acid, a derivative of ascorbic acid, and a reducing polyhydric phenol, and has a reducing property capable of suppressing the ionization of metal fine particles, and has a reducing property that can suppress the ionization of metal fine particles.
  • a low molecular weight material that can be easily coated on a surface is preferred.
  • the solvent of the dispersion is water or an aqueous solvent, it is preferable that the solvent exhibits water solubility.
  • Ascorbic acid or its derivatives include ascorbic acid, calcium ascorbate, sodium ascorbate, ascorbic acid-2-glucoside, 2-o-methylascorbic acid, 3-o-methylascorbic acid, 2-o-ethylascorbic acid, 3-o-ethyl ascorbic acid, ascorbic acid-6-palmitate, ascorbic acid-6-stearate, ascorbic acid dipalmitate, 6-o-palmitoyl ascorbic acid-2-o-phosphate, 6-o-acyl -2-o- ⁇ -D-glucopyranosyl-L-ascorbic acid, magnesium ascorbic acid-2-phosphate, ascorbic acid-2-phosphate, sodium ascorbic acid-2-phosphate, ascorbic acid-2-sulfate, ascorbic acid Examples include potassium acid-2-sulfate, barium ascorbic acid-2-sulfate, disodium ascorbic acid-2-sulfate, and trisodium ascorbic acid-2-phosphate.
  • polyhydric phenols having reducing properties examples include polyhydric phenols such as resorcinol, alkylresorcinol, pyrogallol, catechol, alkylcatechol, hydroquinone, alkylhydroquinone, and phloroglucinol.
  • L-ascorbic acid can be preferably used from the viewpoints of coating properties on metal fine particles, reducing properties, and water solubility.
  • Dispersant with acidic functional group it is desirable to contain a dispersant in order to improve the dispersibility of metal fine particles in the dispersion. Since the metal fine particles of the present invention are coated with the above-mentioned stabilizer, ionization of the metal fine particles is suppressed, and therefore is particularly suitable when using a dispersant having an acidic functional group.
  • the dispersant preferably has at least an acidic functional group such as a carboxyl group, an acid anhydride group, a sulfonic acid group, a phosphoric acid group, and in addition to the above acidic functional groups, it also has an amino group, an imino group, an ammonium base,
  • the wetting and dispersing agent may have a star polymer structure having a basic functional group such as a heterocyclic group having a basic nitrogen atom or a comb-shaped polymer structure.
  • the dispersant preferably has an acid value in the range of 3 to 100 mgKOH/g, preferably 4 to 30 mgKOH/g, particularly 5 to 20 mgKOH/g.
  • the storage stability of the dispersion may be lower than when it is within the above range, whereas if the acid value is higher than the above range, the storage stability of the dispersion may be lower than when it is within the above range. There is a risk that the water resistance of the coating film will be lower than that of the above.
  • the dispersant used in the present invention preferably has a weight average molecular weight of 1,000 or more.
  • the weight average molecular weight of the dispersant is less than 1,000, sufficient steric hindrance by the acidic functional group or the acidic functional group and the basic functional group cannot be obtained.
  • the side chain or main chain skeleton to which these functional groups are bonded is not particularly limited, and can be made of polyester, polyacrylic, polyether, polyoxyalkylene, or the like.
  • the acidic functional group or the acidic functional group and the basic functional group of the dispersant strongly adsorb to the metal fine particles, giving the metal fine particles polarity, causing the metal fine particles to repel each other due to electric charge, and causing the metal fine particles to It is thought that the presence of a modifying group of a certain length on the surface forms steric hindrance, and as a result, the metal fine particles can be uniformly dispersed in the solvent without aggregation or sedimentation.
  • Dispersants that can be suitably used in the metal fine particle-containing dispersion of the present invention include, but are not limited to, DISPERBYK-102, 180, 182, 184, 190, 191, 192, 193, 194N, 199, 2060, 2061, 2090, 2095, 2096, 2155, 154 (manufactured by Big Chemie), Sokalan CP9, Lupasol FG, Pluronic PE6400, Pluronic PE6800, Lutropur MSA, Sokalan PA110S, Sokala n CP12S, Sokalan CP13S, Sokalan VA 64P, Lupasol HF, Plurafac LF300 , Pluronic RPE1740, Pluronic RPE3110, Degressal SD40 (manufactured by BASF), SC-0505K, AFB-1521, SC-1015F, AKM-0531, AKM-1511-60 (manufactured by NOF Corporation), among which In particular, DISPERB
  • the dispersant is preferably contained in an amount of 50 to 1000 parts by mass, particularly 100 to 500 parts by mass, per 100 parts by mass of the metal fine particles. If the amount of dispersant is less than the above range, the dispersibility of the metal fine particles will be inferior to that in the above range, while on the other hand, even if the amount of dispersant is greater than the above range, there will be no further effect. There is no hope of improving the performance, and there is a possibility that the economic efficiency will be inferior.
  • the dispersion of the present invention can form a coating film (hereinafter, when it contains a binder resin, it may be referred to as a "paint dispersion").
  • a coating film hereinafter, when it contains a binder resin, it may be referred to as a "paint dispersion”
  • the metal fine particles of the present invention are coated with the above-mentioned stabilizer, the ionization of the metal fine particles is suppressed even when the binder resin has an acidic functional group. This is particularly suitable when using a binder resin having an acidic functional group such as an acid group or a phosphoric acid group.
  • binder resins examples include phenol resins, epoxy resins, urethane resins, melamine resins, urea resins, alkyd resins, unsaturated polyester resins, silicone resins, acrylic resins, and polyester resins, which have been conventionally used as paints.
  • the dispersion of the present invention is preferably an aqueous dispersion, water-dispersible or water-soluble acrylic resins, polyester resins, and cellulose resins can be suitably used.
  • an electron beam curable resin can be used, but a self-crosslinking acrylic resin that does not use a curing agent can be particularly preferably used.
  • the binder resin is preferably added in an amount of 5,000 to 100,000 parts by mass per 100 parts by mass of the metal fine particles.
  • water-dispersible or water-soluble acrylic resins include acrylic resin emulsions obtained by emulsion polymerization of ethylenically unsaturated monomers having acidic functional groups such as carboxyl groups, acid anhydride groups, sulfonic acid groups, and phosphoric acid groups. can.
  • carboxyl group-containing ethylenically unsaturated monomers such as acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, propyl acrylic acid, isopropyl acrylic acid, itaconic acid, maleic anhydride, and fumaric acid
  • p-vinylbenzene examples include sulfonic acid-containing ethylenically unsaturated monomers such as sulfonic acid and p-acrylamidopropanesulfonic acid, and phosphoric acid group-containing ethylenically unsaturated monomers such as phosphoric acid monoester of 2-hydroxyethyl acrylate.
  • an acrylic resin emulsion comprising a carboxyl group-containing ethylenically unsaturated monomer is preferred.
  • the acrylic resin emulsion can also contain (meth)acrylic acid alkyl esters and hydroxyl group-containing ethylenically unsaturated monomers.
  • the acid value of the acrylic resin is preferably in the range of 3 to 100 mgKOH/g. If it is lower than the above range, there is a risk that the storage stability of the dispersion will decrease, and when forming a coating, there is a risk that sufficient curability may not be obtained.On the other hand, if it is lower than the above range This may result in a decrease in polymerization stability and a decrease in the water resistance of the coating film.
  • the number average molecular weight of the acrylic resin is not particularly limited, but is preferably in the range of 10,000 to 50,000.
  • Water-dispersible or water-soluble polyester resins include polyester resins containing acidic functional groups such as carboxyl groups, acid anhydride groups, sulfonic acid groups, and phosphoric acid groups, and these components are included in the polyester resin dispersion. Although it may be coordinated on the surface, it is preferable that the monomer having the acidic functional group is present in the polyester resin skeleton as a copolymerization component.
  • Such monomers include carboxylic anhydrides such as phthalic anhydride, succinic anhydride, maleic anhydride, trimellitic anhydride, itaconic anhydride, citraconic anhydride, 5-sulfoisophthalic acid, 4-sulfonaphthalene-2
  • Examples include metal salts of sulfonic acid-containing monomers such as , 7-dicarboxylic acid, and 5(4-sulfophenoxy)isophthalic acid.
  • an acrylic resin-modified polyester resin obtained by graft-polymerizing a vinyl monomer having an acidic functional group onto a polyester resin may be used.
  • the monomer to be combined with the monomer having an acidic functional group to form a polyester resin is not particularly limited as long as it is commonly used in the polymerization of polyester resins.
  • the polycarboxylic acid component constituting the polyester resin include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, and naphthalene dicarboxylic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, and dodecanedione.
  • acids aliphatic dicarboxylic acids such as dimer acid, unsaturated dicarboxylic acids such as (anhydrous) maleic acid, fumaric acid, terpene-maleic acid adducts, 1,4-cyclohexanedicarboxylic acid, tetrahydrophthalic acid, hexahydroisophthalic acid,
  • examples include alicyclic dicarboxylic acids such as 1,2-cyclohexenedicarboxylic acid, trivalent or higher polyhydric carboxylic acids such as (anhydrous) trimellitic acid, (anhydrous) pyromellitic acid, and methylcyclohexenetricarboxylic acid. , one type or two or more types can be selected and used from these.
  • polyhydric alcohol component constituting the polyester resin examples include ethylene glycol, propylene glycol (1,2-propanediol), 1,3-propanediol, 1,4-butanediol, 1,2-butanediol, 1 , 3-butanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 2-ethyl- 2-Butyl-1,3-propanediol, 2,4-diethyl-1,5-pentanediol, 1-methyl-1,8-octanediol, 3-methyl-1,6-hexanediol, 4-methyl- Aliphatic glycols such as 1,7-heptanediol, 4-methyl-1,8-octanediol, 4-propy
  • the acid value of the polyester resin is preferably in the range of 3 to 100 mgKOH/g. If it is lower than the above range, there is a risk that the storage stability of the dispersion will be lower than when it is within the above range, and when forming a coating, there is a risk that sufficient curability may not be obtained. be. On the other hand, if the amount exceeds the above range, the polymerization stability may be lowered compared to the case where the amount is within the above range, and the water resistance of the coating film may also be lowered.
  • the number average molecular weight of the polyester resin is not particularly limited, but is preferably in the range of 5,000 to 30,000.
  • cellulose resins include cellulose and/or cellulose derivatives, and examples of cellulose derivatives include cellulose ether in which some or all of the hydroxyl groups of cellulose are etherified, and cellulose in which some or all of the hydroxyl groups of cellulose are esterified. Examples include esters.
  • cellulose resins examples include cellulose ethers such as methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxyethylmethylcellulose, hydroxypropylmethylcellulose, hydroxybutylmethylcellulose, ethylhydroxyethylcellulose, carboxymethylcellulose, carboxyethylcellulose, and carboxymethylhydroxyethylcellulose;
  • cellulose ethers such as methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxyethylmethylcellulose, hydroxypropylmethylcellulose, hydroxybutylmethylcellulose, ethylhydroxyethylcellulose, carboxymethylcellulose, carboxyethylcellulose, and carboxymethylhydroxyethylcellulose
  • cellose esters such as cellulose acetate, cellulose propionate, cellulose butyrate, cellulose acetate propionate, and cellulose acetate butyrate, and one or more types thereof can be selected and used.
  • carboxyalkylcelluloses such as carboxymethylcellulose and
  • Dispersion medium In the dispersion of the present invention, the following solvents can be used as the dispersion medium for dispersing the metal fine particles. , various water solvents such as ion-exchanged water and pure water, ester solvents such as methyl acetate, ethyl acetate, and butyl acetate, hydrocarbon solvents such as hexane, heptane, toluene, xylene, and cyclohexane, methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone.
  • various water solvents such as ion-exchanged water and pure water, ester solvents such as methyl acetate, ethyl acetate, and butyl acetate, hydrocarbon solvents such as hexane, heptane, toluene, xylene, and cyclohexane, methyl isobutyl ketone, methyl
  • aqueous solvents or aqueous mixed solvents can be preferably used, and particularly water or a mixed solvent of water and an amphipathic organic solvent such as alcohol is preferably used. I can do it.
  • metal fine particles can be uniformly dispersed in the various dispersion media described above for a long period of time without agglomeration or sedimentation. It is preferable that the liquid contains metal fine particles in an amount of 10% by mass or less, particularly 0.001 to 1% by mass.
  • a dispersant having an acidic functional group and/or a binder resin having an acidic functional group, a stabilizer and a solvent, an antioxidant, a surfactant, a curing agent, a catalyst, etc. , a polymerization initiator, and other components as necessary is added to a known formulation. It can also be contained.
  • the dispersion of the present invention can be prepared by the following manufacturing method.
  • First step A fatty acid metal salt is added to a polyol and heated to prepare a polyol solution containing metal fine particles whose surfaces are coated with a fatty acid and/or an ester compound of the fatty acid and the polyol.
  • the heating temperature is preferably lower than the decomposition starting temperature of the fatty acid metal salt used, and the heating and mixing time is preferably 60 to 360 minutes. If the heating temperature is equal to or higher than the decomposition start temperature of the fatty acid metal salt, the fatty acid and/or ester compound will not be coated on the metal fine particles, and the metal fine particles may be oxidized.
  • the decomposition start temperature is defined by JIS K 7120.
  • the amount of fatty acid metal salt blended is preferably in the range of 0.1 to 5% by mass based on the polyol.
  • the amount of the fatty acid metal salt is less than the above range, there is a possibility that sufficient antimicrobial properties cannot be imparted to the dispersion compared to when the amount is within the above range.
  • the amount of the fatty acid metal salt is greater than the above range, the economical efficiency is inferior to when the amount is within the above range.
  • the polyol include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, and glycerin, which are appropriately selected in combination with the low-boiling solvent described below.
  • a polyol solution containing fine metal particles coated with a fatty acid and/or an ester compound of the fatty acid and a polyol is mixed with a low boiling point solvent to prepare a mixed solution.
  • the low boiling point solvent is preferably added in an amount of 10 to 200% by mass based on the polyol.
  • Low boiling point solvents include esters such as methyl acetate, ethyl acetate, and butyl acetate, hydrocarbons such as hexane, heptane, toluene, xylene, and cyclohexane, and ketones such as methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone.
  • ester solvents are preferred, and among them, butyl acetate, ethyl acetate, and methyl isobutyl ketone are preferably used.
  • the low boiling point solvent is not compatible with the polyol, and it is preferable to combine the polyol and the low boiling point solvent so that the difference in solubility parameter (Sp value) between the polyol and the low boiling point solvent is 3 or more.
  • Sp value solubility parameter
  • Sp value diethylene glycol
  • butyl acetate Sp value: 8.4
  • the metal particles are sufficiently coated with the ester compound of fatty acid and polyol, so there is no need to intentionally blend the ester compound into the low boiling point solvent, but depending on the amount of coating in the first step, can also be blended.
  • a solution containing fine metal particles coated with a fatty acid and/or an ester compound of the fatty acid and the polyol in a polyol is obtained. Removal of the low boiling point solvent can be performed by conventionally known separation methods such as decantation and extraction.
  • recovery of the metal fine particles from the polyol can be performed by a conventionally known separation method such as membrane separation, centrifugation, decantation, etc., but is not limited thereto, but membrane separation is preferable.
  • the separated metal fine particles are thoroughly washed with water or a low boiling point solvent such as butyl acetate or hexane, and then heated and dried at 40 to 50°C for 60 to 360 minutes to sufficiently remove moisture, thereby removing fatty acids and esters. It is possible to obtain dry metal fine particle powder having a compound coating amount of 0.1 to 20% by mass.
  • the metal fine particle powder is added and mixed.
  • the dispersant is preferably added in an amount of 50 to 1000 parts by mass per 100 parts by mass of the metal fine particles.
  • a stabilizer such as L-ascorbic acid is added in an amount of 150 parts by mass or more per 100 parts by mass of the metal fine particles, and further mixing and dispersion treatment is performed to form the metal fine particles, the stabilizer, and the dispersion.
  • a dispersion containing the agent can be obtained.
  • the coating dispersion when the coating dispersion further contains a binder resin containing an acidic functional group, the dispersion prepared in the fourth step described above, the binder resin and It is prepared by uniformly mixing with a curing agent if necessary.
  • the binder resin is preferably added in an amount of 5,000 to 100,000 parts by mass per 100 parts by mass of the metal fine particles.
  • Metal fine particles containing a stabilizer in a low boiling point solvent can be produced by the following method in addition to the above-mentioned production method. That is, in the first step of the first production method described above, fatty acids and/or By preparing a dispersion of metal fine particles coated with the fatty acid ester compound and then passing through the second to fourth steps described above, a metal fine particle dispersion further containing a stabilizer can be obtained.
  • a fine metal particle powder containing the agent can be produced. That is, the polyol solution containing the metal fine particles coated with the fatty acid and/or the ester compound of the fatty acid and the polyol obtained in the first step of the first manufacturing method described above is used as it is, and the metal fine particles recovered from this solution are used. may be used.
  • the viscosity of the polyol dispersion is high due to excess fatty acid metal salts, free fatty acids or ester compounds, and other impurities, and it is difficult to remove the low boiling point solvent as it is, so dilute it with ethanol etc. to reduce the viscosity.
  • After lowering the temperature remove the solvent.
  • the fatty acid metal salt by heating in an inert atmosphere, adding the above-mentioned stabilizer or a stabilizer and an ester compound, and pulverizing and mixing it, it is possible to coat the fatty acid metal salt with at least the stabilizer.
  • the dispersion of the present invention can also be used as it is by spraying it onto a base material such as a nonwoven fabric, a resin film, or a textile product, and can be used as a molded article with a coating made of the dispersion of the present invention formed on the surface of the base material. I can do it.
  • a molded article can be obtained by preparing a paint dispersion containing a binder resin, applying this to the above-mentioned base material, and then baking and drying it to form a coating (coating film).
  • molded objects such as films, sheets, nonwoven fabrics, fibers, etc. can also be formed directly from the above coating dispersion and used.
  • Example 1 ⁇ Preparation of dispersion liquid containing metallic copper fine particles and dispersant> (Example 1) DIPERBYK-190 (manufactured by BYK Chemie, acid value 10 mgKOH/g) as a dispersant was added to distilled water in an amount of 100 parts by mass based on 100 parts by mass of metallic copper fine particles, and the mixture was stirred. Next, the metallic copper fine particle powder produced above was added so that the metallic copper component was 0.1% by mass, and ultrasonication was performed for 10 minutes.
  • DIPERBYK-190 manufactured by BYK Chemie, acid value 10 mgKOH/g
  • L-ascorbic acid was added in an amount of 1000 parts by mass based on 100 parts by mass of metallic copper microparticles, and ultrasonication was further performed for 10 minutes to obtain an ascorbic acid-containing metallic copper microparticle dispersion.
  • Example 2 A dispersion liquid was prepared in the same manner as in Example 1, except that the proportion of L-ascorbic acid was changed to 200 parts by mass per 100 parts by mass of metallic copper fine particles.
  • Example 3 A dispersion liquid was prepared in the same manner as in Example 1 except that the proportion of L-ascorbic acid was changed to 500 parts by mass per 100 parts by mass of metallic copper fine particles.
  • Example 4 A dispersion liquid was prepared in the same manner as in Example 1 except that L-ascorbic acid was changed to 3-o-ethyl-L-ascorbic acid and 6000 parts by mass was added to 100 parts by mass of metal copper fine particles.
  • Example 5 A dispersion liquid was prepared in the same manner as in Example 1 except that L-ascorbic acid was changed to pyrogallol, which is a polyhydric phenol having reducing properties.
  • Example 1 A dispersion was prepared in the same manner as in Example 1 except that L-ascorbic acid was not added.
  • Example 2 A dispersion was prepared in the same manner as in Example 1, except that L-ascorbic acid and DISPERBYK-190 were not added.
  • Example 3 A dispersion liquid was prepared in the same manner as in Example 1, except that the proportion of L-ascorbic acid was changed to 100 parts by mass relative to 100 parts by mass of metallic copper fine particles.
  • Example 4 A dispersion liquid was prepared in the same manner as in Example 1 except that citric acid was used instead of L-ascorbic acid.
  • Example 5 A dispersion liquid was prepared in the same manner as in Example 1 except that L-ascorbic acid was changed to sodium phosphinate monohydrate.
  • Example 6 A dispersion liquid was prepared in the same manner as in Example 1 except that L-ascorbic acid was changed to D-maltose monohydrate.
  • ⁇ Zeta potential measurement method For the zeta potential, a zeta potential/particle size/molecular weight measurement system ELSZ-2000ZS manufactured by Otsuka Electronics Co., Ltd. was used. The measurement was carried out using a standard cell unit at a measurement voltage of 60V. A change in the absolute value of the zeta potential compared to Comparative Example 1 in which no L-ascorbic acid was added indicates that L-ascorbic acid is acting on the surface of the metallic copper fine particles. Measurements were made for Examples 1 to 5 and Comparative Examples 1 to 6. The results are shown in Table 1.
  • Example 11 4.0% by mass of the metallic copper fine particle dispersion of Example 1 so that the metal component concentration was 0.1% by mass based on the solid content of binder resin B (self-crosslinking acrylic acid ester emulsion polymer), A paint dispersion was prepared by mixing 8.9% by mass of binder resin B, 86.6% by mass of pure water, and 0.5% by mass of ascorbic acid.
  • binder resin B self-crosslinking acrylic acid ester emulsion polymer
  • FIG. 1 shows X-ray diffraction (XRD) charts of the paint dispersions obtained in Example 6 and Comparative Examples 7, 10, and 11 after 3 months of preparation. It can be seen that metallic copper fine particles are present in the paint dispersion prepared in Example 6 even after 3 months have elapsed.
  • FIG. 2 shows X-ray diffraction charts of the paint dispersions obtained in Example 6 and Comparative Example 7 immediately after preparation and after 3 days. In the paint dispersion of Comparative Example 7, which was the same as Example 6 except that L-ascorbic acid was not added, no diffraction peak of metallic copper fine particles was detected after 3 days.
  • Example 11 The coating dispersion prepared in Example 11 was applied to an untreated nonwoven fabric with a brush, and then dried in a dryer at 80° C. for 5 minutes. Thereafter, it was dried for 3 minutes in a dryer at 150°C to obtain a nonwoven fabric (molded body) on which metallic copper fine particles were immobilized.
  • a paint dispersion liquid (Comparative example 13) was prepared by mixing 8.9% by mass of binder resin B and 87.1% by mass of pure water. The prepared paint dispersion was applied to an unprocessed nonwoven fabric with a brush, and then dried in a dryer at 80° C. for 5 minutes. Thereafter, it was dried for 3 minutes in a dryer at 150°C to obtain a nonwoven fabric (molded body) on which metallic copper fine particles were immobilized.
  • the test was conducted in accordance with JIS L 1922.
  • (1) Host cells are infected with a virus, and after culturing, cell debris is removed by centrifugation to obtain a virus suspension.
  • (2) The virus suspension obtained in (1) above is diluted 10 times with sterile distilled water and used as a test virus suspension.
  • Table 3 shows the appearance evaluation of the paint dispersions containing binder resin B (Example 11 and Comparative Example 13) immediately after preparation and after storage for 7 days. Immediately after preparation, no change in color was observed in either Example 11 or Comparative Example 13, but when stored at room temperature for 7 days, the paint dispersion of Example 11 did not cause any change in color. However, on the other hand, a change in color was observed in the paint dispersion of Comparative Example 13.
  • the dispersion of the present invention can be directly applied to or impregnated into textile products, etc. to produce paper products, masks, wet tissues, air conditioner filters, air purifier filters, clothing, work clothes, curtains, carpets, automobile parts, packaging, etc. It becomes possible to apply antimicrobial coatings to textile products such as parts, freshness-preserving materials, sheets, towels, bath mats, diaper covers, stuffed animals, slippers, shoe insoles, and cleaning products such as wipers.
  • an aqueous solvent as a dispersion medium of a dispersion liquid, it can be used as a diluent for an aqueous composition, or by containing a binder resin in a dispersion liquid, an antimicrobial coating film can be formed on the surface. Molded products can be obtained. Furthermore, it can be used for medical devices, packaging films for medical devices, waste containers, garbage bags, wall and floor materials for nursing care facilities, hospitals, schools, and other public facilities, wax coating materials, vomit disposal tools, etc. can.

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Abstract

The present invention relates to a dispersion containing metal microparticles, a dispersant having an acidic functional group, and/or a binder resin having an acidic functional group. The present invention can provide a dispersion that is capable of stably exhibiting, over a long period of time, excellent antimicrobial properties possessed by the metal microparticles, said dispersion containing, in an amount equal to or greater than 150 parts by mass relative to 100 parts by mass of the metal microparticles, a stabilizer composed of at least one of an ascorbic acid, an ascorbic acid derivative, and a reducing polyhydric phenol, thereby effectively suppressing ionization of the metal microparticles.

Description

経時安定性に優れた抗微生物性を有する金属微粒子含有分散液Dispersion containing fine metal particles with antimicrobial properties and excellent stability over time
　本発明は、アスコルビン酸等で被覆された金属微粒子、分散剤及び／又はバインダー樹脂を含有する、経時安定性に優れた抗微生物性を有する分散液に関する。 The present invention relates to a dispersion liquid containing fine metal particles coated with ascorbic acid or the like, a dispersant, and/or a binder resin and having antimicrobial properties with excellent stability over time.
　銀や銅等の金属微粒子を有効成分とする抗菌性や、抗ウイルス性等を有する材料として、分散媒中に金属微粒子を分散させて成る分散液や、分散媒で希釈した塗料用のバインダー樹脂に金属微粒子を含有させて成る塗料分散液、或いは熱可塑性樹脂に溶融混錬させたり、熱硬化性樹脂に金属微粒子を含有させて成る樹脂組成物等、種々の形態で提供されている。
　例えば、下記特許文献１には、一価の銅化合物微粒子と、還元剤と、分散媒を含有し、ｐＨ６以下であることを特徴とする抗ウイルス組成物が記載されている。また下記特許文献２には、銅粒子及び銅化合物粒子の少なくともいずれか一方を酸化物粒子に担持した、平均二次粒子径が８０ｎｍ～６００ｎｍの銅担持酸化物と、平均二次粒子径が１μｍ～１５μｍの硫酸バリウムと撥水性の樹脂バインダーとを有する抗ウイルス性塗膜が記載されている。 Dispersions made by dispersing metal particles in a dispersion medium, and binder resins for paints diluted with a dispersion medium, as materials with antibacterial and antiviral properties that contain metal particles such as silver and copper as active ingredients. It is provided in various forms, such as a paint dispersion made by containing fine metal particles in a resin, a resin composition made by melting and kneading a thermoplastic resin, or a resin composition made by making a thermosetting resin contain fine metal particles.
For example, Patent Document 1 listed below describes an antiviral composition containing monovalent copper compound fine particles, a reducing agent, and a dispersion medium, and having a pH of 6 or less. Further, Patent Document 2 below describes a copper-supported oxide having an average secondary particle size of 80 nm to 600 nm, in which at least one of copper particles and copper compound particles is supported on oxide particles, and a copper-supported oxide having an average secondary particle size of 1 μm. Antiviral coatings with ~15 μm barium sulfate and a water-repellent resin binder have been described.
　しかしながら、金属微粒子は凝集しやすく、均一に分散させることは困難であり、特に、分散液を抗ウイルス組成物として利用する場合や、さらに塗料用のバインダー樹脂と混合してコーティングされた抗ウイルス性塗膜として用いる場合において、金属微粒子が有する抗ウイルス性を効率よく発現することが困難であった。
　金属微粒子の分散性が向上された分散液として、本発明者等により、脂肪酸で被覆された金属微粒子を含有する分散液が提案されている（特許文献３及び４）。 However, metal fine particles tend to aggregate and are difficult to disperse uniformly, especially when the dispersion is used as an antiviral composition, or when coated with a binder resin for paint. When used as a coating film, it has been difficult to efficiently exhibit the antiviral properties of metal fine particles.
As a dispersion liquid with improved dispersibility of metal fine particles, the present inventors have proposed a dispersion liquid containing metal fine particles coated with a fatty acid (Patent Documents 3 and 4).
特許第５１９４１８５号公報Patent No. 5194185 特開２０１５－２０５９９８号公報Japanese Patent Application Publication No. 2015-205998 特開２０１７－１２８８０９号公報Japanese Patent Application Publication No. 2017-128809 特開２０１８－１００２５５号公報JP 2018-100255 Publication
　上記特許文献３及び４に記載された金属微粒子含有分散液においては、金属微粒子表面が脂肪酸及び／又は該脂肪酸のエステル化合物によって被覆されることで、金属微粒子の凝集を防止し、金属微粒子が分散媒中に均一分散することが可能になる。
　しかしながら、金属微粒子を、ある特定の分散剤や塗料用などのバインダー樹脂と混合させて用いる場合に、分散液の調製直後には金属微粒子が有する優れた抗ウイルス性等を発現可能であったが、この分散液を長期間保管した場合には抗ウイルス性等の金属微粒子が有する効果が得られないという問題が生じる場合があった。このような問題を解決するために本発明者等が鋭意研究を行ったところ、金属微粒子が有する効果の消失は、分散剤やバインダー樹脂がカルボキシル基のような酸性官能基を有する場合に生じ、これは金属微粒子が酸性官能基と共存することによって、金属微粒子のイオン化に起因することが判明した。 In the metal fine particle-containing dispersions described in Patent Documents 3 and 4, the surface of the metal fine particles is coated with a fatty acid and/or an ester compound of the fatty acid, thereby preventing agglomeration of the metal fine particles and dispersing the metal fine particles. This enables uniform dispersion in the medium.
However, when fine metal particles are used in combination with a certain dispersant or binder resin for paint, it has been possible to exhibit the excellent antiviral properties of fine metal particles immediately after preparing the dispersion liquid. However, when this dispersion liquid is stored for a long period of time, a problem arises in that the effects of the metal fine particles, such as antiviral properties, cannot be obtained. In order to solve these problems, the present inventors conducted intensive research and found that the effect of metal fine particles disappears when the dispersant or binder resin has an acidic functional group such as a carboxyl group. It was found that this was caused by ionization of the metal fine particles due to their coexistence with acidic functional groups.
　従って本発明の目的は、酸性官能基を有する分散剤及び／又は酸性官能基を有するバインダー樹脂を含有する分散液において、金属微粒子のイオン化が有効に抑制され、金属微粒子が有する優れた抗微生物性を長期にわたって安定して発現可能な分散液に関する。 Therefore, an object of the present invention is to effectively suppress the ionization of metal fine particles in a dispersion containing a dispersant having an acidic functional group and/or a binder resin having an acidic functional group, and to improve the antimicrobial properties of the metal fine particles. This invention relates to a dispersion liquid that can stably express over a long period of time.
　本発明によれば、アスコルビン酸，アスコルビン酸の誘導体及び還元性多価フェノールの少なくとも１種から成る安定化剤、及び金属微粒子、並びに酸性官能基を有する分散剤及び／又は酸性官能基を有するバインダー樹脂を含有し、前記安定化剤を金属微粒子１００質量部に対して、１５０質量部以上の量で含有することを特徴とする分散液が提供される。 According to the present invention, a stabilizer comprising at least one of ascorbic acid, a derivative of ascorbic acid, and a reducing polyhydric phenol, metal fine particles, and a dispersant having an acidic functional group and/or a binder having an acidic functional group There is provided a dispersion liquid containing a resin and the stabilizer in an amount of 150 parts by mass or more based on 100 parts by mass of metal fine particles.
　本発明の分散液においては、
　（１）前記金属微粒子由来の金属イオン濃度が１００ｐｐｍ以下であること、
　（２）前記金属微粒子の含有量が０．００１～１０質量％であること、
　（３）前記安定化剤の含有量が０．００１５～１５質量％であること、
　（４）前記金属微粒子表面が、前記安定化剤によって被覆されていること、
　（５）前記金属微粒子が、銅又は銅化合物、或いは銀又は銀化合物から成ること、
　（６）前記分散剤及びバインダー樹脂の酸性官能基が、カルボキシル基であること、
　（７）前記バインダー樹脂が、アクリル樹脂，ポリエステル樹脂及びセルロース樹脂の何れかであること、
　（８）前記金属微粒子表面が、脂肪酸及び／又は脂肪酸エステルによって更に被覆されていること、
が好適である。 In the dispersion of the present invention,
(1) The metal ion concentration derived from the metal fine particles is 100 ppm or less;
(2) the content of the metal fine particles is 0.001 to 10% by mass;
(3) the content of the stabilizer is 0.0015 to 15% by mass;
(4) the surface of the metal fine particles is coated with the stabilizer;
(5) the metal fine particles are made of copper or a copper compound, or silver or a silver compound;
(6) the acidic functional group of the dispersant and binder resin is a carboxyl group;
(7) the binder resin is any one of acrylic resin, polyester resin, and cellulose resin;
(8) the surface of the metal fine particles is further coated with fatty acid and/or fatty acid ester;
is suitable.
　本発明によればまた、金属微粒子表面が、アスコルビン酸，アスコルビン酸の誘導体及び還元性多価フェノールの少なくとも１種から成る安定化剤で被覆されて成ることを特徴とする金属微粒子が提供される。
　本発明の金属微粒子においては、銅又は銅化合物、或いは銀又は銀化合物の何れかから成る金属微粒子であることが好適である。
　本発明によれば更に、上記分散液から成る被膜を有することを特徴とする抗微生物性成形体が提供される。 The present invention also provides metal fine particles whose surfaces are coated with a stabilizer comprising at least one of ascorbic acid, an ascorbic acid derivative, and a reducing polyhydric phenol. .
The metal fine particles of the present invention are preferably metal fine particles made of copper or a copper compound, or silver or a silver compound.
According to the present invention, there is further provided an antimicrobial molded article having a coating made of the above dispersion.
　本発明の分散液は、金属微粒子の表面が、アスコルビン酸，アスコルビン酸の誘導体及び還元性多価フェノールの少なくとも１種から成る安定化剤によって被覆されていることにより、カルボキシル基などの酸性官能基を有する分散剤及び／又は酸性官能基を有するバインダー樹脂を含有する分散液であっても、金属微粒子のイオン化が有効に抑制され、金属微粒子が有する優れた抗微生物性を長期にわたって発現することが可能になる。
　また金属微粒子表面が、上記安定化剤、或いは更に脂肪酸及び／又は脂肪酸エステルで被覆されていることにより、金属微粒子は分散液中で凝集することなく均一に分散可能となるため、例えば、塗料組成物として塗膜を形成した場合にも、塗膜に優れた抗微生物性を付与することが可能となる。 In the dispersion liquid of the present invention, the surface of the metal fine particles is coated with a stabilizer consisting of at least one of ascorbic acid, a derivative of ascorbic acid, and a reducing polyhydric phenol, so that acidic functional groups such as carboxyl groups Even in the case of a dispersion containing a dispersant having a dispersant and/or a binder resin having an acidic functional group, the ionization of metal fine particles can be effectively suppressed, and the excellent antimicrobial properties of metal fine particles can be expressed over a long period of time. It becomes possible.
Furthermore, since the surface of the metal fine particles is coated with the above-mentioned stabilizer or further with a fatty acid and/or a fatty acid ester, the metal fine particles can be uniformly dispersed in the dispersion without agglomerating. Even when a coating film is formed as a product, it is possible to impart excellent antimicrobial properties to the coating film.
　本発明の分散液の上述した効果は、後述する実施例の結果からも明らかである。すなわち、例えば、Ｌ－アスコルビン酸等の安定化剤を含有する分散液は、そのゼータ電位の変位から明らかなように、金属銅微粒子の表面に安定化剤が被覆されていると考えられ、これにより酸性官能基を有する分散剤及び／又は酸性官能基を有するバインダー樹脂と混合させ分散液（実施例１～１１）として、３日間経過後でも、金属銅微粒子のイオン化が抑制され、優れた抗微生物性が発現されている。
　これに対して、安定化剤が配合されていない場合（比較例１～２、７～８、１３）、アスコルビン酸を配合しているとしてもその量が少ない場合（比較例３、９）、或いは安定化剤を配合しているとしても、アスコルビン酸又はその誘導体、或いは還元性多価フェノール以外の安定化剤を配合した場合（比較例４～６、１０～１２）では、経時により抗微生物性が発現されていないことが明らかである。
　また図１に示すように、本発明の塗料分散液（実施例６）では、調製から３か月経過後でもＸＲＤ測定により金属銅由来の回折ピークが検出され、つまり金属銅が存在していることが明らかであるのに対し、比較例７，１０，１１の塗料分散液においては、金属銅の回折ピークは検出されず、金属銅微粒子が消失してしまっていることがわかる。 The above-mentioned effects of the dispersion of the present invention are also clear from the results of Examples described below. That is, for example, in a dispersion containing a stabilizer such as L-ascorbic acid, it is thought that the surface of metallic copper particles is coated with the stabilizer, as is clear from the change in zeta potential. When mixed with a dispersant having an acidic functional group and/or a binder resin having an acidic functional group to form a dispersion liquid (Examples 1 to 11), the ionization of the metallic copper fine particles was suppressed even after 3 days had passed, resulting in excellent resistance. Microbial properties are expressed.
On the other hand, when no stabilizer is blended (Comparative Examples 1-2, 7-8, 13), and even if ascorbic acid is blended, the amount is small (Comparative Examples 3, 9), Alternatively, even if a stabilizer is blended, in cases where a stabilizer other than ascorbic acid or its derivatives or reducing polyhydric phenol is blended (Comparative Examples 4 to 6, 10 to 12), antimicrobial effects may deteriorate over time. It is clear that sex is not expressed.
Furthermore, as shown in Figure 1, in the paint dispersion of the present invention (Example 6), a diffraction peak derived from metallic copper was detected by XRD measurement even after 3 months had passed from preparation, indicating that metallic copper was present. On the other hand, in the paint dispersions of Comparative Examples 7, 10, and 11, no diffraction peak of metallic copper was detected, indicating that the metallic copper fine particles had disappeared.
　なお、本明細書において、抗微生物性とは、抗ウイルス性、抗カビ性、抗菌性等を総称するものであり、ウイルス等を不活性化させる効果をいうものである。 In this specification, antimicrobial property is a general term for antiviral property, antifungal property, antibacterial property, etc., and refers to the effect of inactivating viruses and the like.
実施例１及び比較例１，４，５で得られた酸性官能基を有する分散剤を含む分散液と、さらにバインダー樹脂Ａとして酸性官能基を有するアクリル系樹脂エマルジョンとを混合した塗料分散液（実施例６及び比較例７，１０，１１）について、調製から３か月経過後のＸ線回折（ＸＲＤ）のチャートを示す図である。A coating dispersion (a coating dispersion) in which a dispersion containing a dispersant having an acidic functional group obtained in Example 1 and Comparative Examples 1, 4, and 5 was mixed with an acrylic resin emulsion having an acidic functional group as a binder resin A ( It is a figure which shows the X-ray diffraction (XRD) chart 3 months after preparation about Example 6 and Comparative Examples 7, 10, 11). 実施例１及び比較例１で得られた分散液と、さらにバインダー樹脂Ａとして酸性官能基を有するアクリル系樹脂エマルジョンとを混合した塗料分散液（実施例６及び比較例７）について、調製直後及び３日経過後のＸ線回折（ＸＲＤ）のチャートを示す図である。Regarding paint dispersions (Example 6 and Comparative Example 7) in which the dispersions obtained in Example 1 and Comparative Example 1 were further mixed with an acrylic resin emulsion having an acidic functional group as binder resin A, immediately after preparation and FIG. 3 is a diagram showing an X-ray diffraction (XRD) chart after 3 days. 実施例１及び比較例１で得られた分散液と、バインダー樹脂Ａとして酸性官能基を有するアクリル系樹脂エマルジョンとを混合した塗料分散液（実施例６及び比較例７）について、調製直後及び３日経過後の外観変化を示す写真である。Regarding paint dispersions (Example 6 and Comparative Example 7) in which the dispersions obtained in Example 1 and Comparative Example 1 were mixed with an acrylic resin emulsion having an acidic functional group as binder resin A, immediately after preparation and It is a photograph showing changes in appearance after a day has passed.
（分散液）
　本発明の分散液において、抗微生物性を示す有効成分は金属微粒子であり、この金属微粒子から発生する活性酸素の酸化力によって、ウイルス等の微生物の蛋白質を変性および分解すると共に、金属微粒子が蛋白質のチオール基と反応することによって蛋白質を変性させ、ウイルス等を不活性化できると考えられるが、この金属微粒子は、分散液中にカルボキシル基等の酸性官能基を有する分散剤やバインダー樹脂が存在すると、経時により金属微粒子とこの酸性官能基が反応して、金属イオン化を生じてしまい、所期の抗微生物性を得ることができない。
　本発明においては、酸性官能基を有する分散剤及び／又は酸性官能基を有するバインダー樹脂を含有する分散液であっても、アスコルビン酸，アスコルビン酸の誘導体及び還元性多価フェノールの少なくとも１種から成る還元性を有する安定化剤が、金属微粒子１００質量部に対して、１５０質量部以上の量で含有されていることが重要であり、これにより金属微粒子のイオン化抑制効果を発現することが可能となる。
　金属微粒子に対する安定化剤の好適な含有量は、分散液が酸性基を有する分散剤のみを含有する分散液の場合には、金属微粒子１００質量部に対して安定化剤を１５０～８０００質量部、好適には２００～６０００質量部、さらに好ましくは３００～２０００質量部の範囲で含有することができ、分散液が酸性基を有するバインダー樹脂を含有する塗料分散液である場合には、金属微粒子１００質量部に対して安定化剤を１５０～２００００質量部、好適には２００～１７０００質量部、さらに好ましくは２００～１５０００質量部の範囲で含有することができる。
　尚、安定化剤の含有量の上限については、金属微粒子表面の被覆に使用されなかった余剰の安定化剤が分散液中に均一に分散可能である限りその制限はないが、分散液中の安定化剤の含有量が１５質量％以下、さらに８質量％以下、特に６質量％以下の範囲となるように含有されていることが好適であり、これにより分散媒として水や水系溶媒を用いた場合にも、安定化剤を均一に分散させることが可能になると共に、経済性の点からも好適である。さらに安定化剤の含有量が過剰になると、分散液あるいは塗料分散液を塗布して得られる塗膜の外観を損なうため、上記範囲が好適である。
　本発明の分散液においては、還元性を有する安定化剤によって金属微粒子表面が被覆保護されることで、金属微粒子と分散剤及び／又は樹脂バインダーの酸性官能基との反応を抑制、つまり金属微粒子のイオン化を抑制して、長期にわたって金属微粒子の状態を安定的に維持することが可能となる。 (Dispersion liquid)
In the dispersion of the present invention, the active ingredient exhibiting antimicrobial properties is metal fine particles, and the oxidizing power of active oxygen generated from these metal fine particles denatures and decomposes the proteins of microorganisms such as viruses, and the metal fine particles also denature and decompose proteins of microorganisms such as viruses. It is thought that these metal particles can denature proteins and inactivate viruses by reacting with the thiol groups of Then, over time, the metal fine particles and this acidic functional group react with each other, resulting in metal ionization, making it impossible to obtain the desired antimicrobial properties.
In the present invention, even if the dispersion contains a dispersant having an acidic functional group and/or a binder resin having an acidic functional group, at least one of ascorbic acid, a derivative of ascorbic acid, and a reducing polyhydric phenol is used. It is important that the stabilizing agent having a reducing property is contained in an amount of 150 parts by mass or more per 100 parts by mass of metal fine particles, thereby making it possible to exhibit the effect of suppressing ionization of metal fine particles. becomes.
A suitable content of the stabilizer for the metal fine particles is 150 to 8000 parts by mass of the stabilizer per 100 parts by mass of the metal fine particles when the dispersion liquid contains only a dispersant having an acidic group. , preferably in the range of 200 to 6,000 parts by mass, more preferably 300 to 2,000 parts by mass, and when the dispersion is a paint dispersion containing a binder resin having an acidic group, fine metal particles The stabilizer can be contained in an amount of 150 to 20,000 parts by weight, preferably 200 to 17,000 parts by weight, and more preferably 200 to 15,000 parts by weight per 100 parts by weight.
There is no upper limit on the content of the stabilizer as long as the excess stabilizer not used to coat the surface of the metal fine particles can be uniformly dispersed in the dispersion; It is preferable that the content of the stabilizer is 15% by mass or less, further 8% by mass or less, particularly 6% by mass or less, and this makes it possible to use water or an aqueous solvent as a dispersion medium. Even when the stabilizer is present, it is possible to uniformly disperse the stabilizer, and this is also preferable from the economic point of view. Furthermore, if the content of the stabilizer becomes excessive, the appearance of the coating film obtained by applying the dispersion or coating dispersion will be impaired, so the above range is preferable.
In the dispersion liquid of the present invention, the surface of the metal fine particles is coated and protected with a reducing stabilizer, thereby suppressing the reaction between the metal fine particles and the acidic functional groups of the dispersant and/or resin binder. It becomes possible to suppress the ionization of metal particles and maintain the state of metal fine particles stably for a long period of time.
［金属微粒子］
　本発明の分散液において、抗微生物性を発現する有効成分である金属微粒子としては、銅、銀、金、亜鉛、ニッケル等の金属及びこれらの金属化合物を例示できるが、優れた抗微生物性を発現可能な銅又は銀、或いはこれら金属の化合物であることが好ましく、特に銅又は銅化合物、中でも銅又は一価銅化合物であることが優れた抗ウイルス性の点から好ましい。
　金属微粒子は、１０～５００ｎｍ、特に１０～２００ｎｍの範囲の平均一次粒径を有することが好適である。金属微粒子の平均一次粒子が上記範囲にあることにより、優れた抗微生物性能を効率よく発現することが可能になる。すなわち、このように平均一次粒径の小さい金属微粒子は、金属微粒子の酸素との接触率が高いことから、効率よく活性酸素を発生することができ、優れた抗微生物性能を発現することが可能になる。また金属微粒子粉末は、上記平均一次粒径を有する一次粒子から成り、平均二次粒子径が１００ｎｍ～５００μｍ、特に１００ｎｍ～１００μｍの範囲にあることが好適であり、これにより、粉末状態で得られた金属微粒子を容易に分散媒に分散させることができると共に、バインダー樹脂と混合させ塗料分散液にした際の塗工性等の取扱い性にも優れている。
　尚、本明細書でいう平均一次粒径とは、金属微粒子と金属微粒子との間に隙間がないものを一つの粒子とし、その平均をとったものをいい、平均二次粒径は、金属微粒子同士がパッキングした状態の粒子とし、その平均をとったものをいう。また、一次粒子径の測定は走査型電子顕微鏡（ＳＥＭ）、二次粒子径は動的光散乱（ＤＬＳ）により測定することができる。 [Metal fine particles]
In the dispersion of the present invention, metal particles, which are active ingredients that exhibit antimicrobial properties, include metals such as copper, silver, gold, zinc, and nickel, and compounds of these metals. Copper or silver, or a compound of these metals, which can be expressed, is preferable, and copper or a copper compound, especially copper or a monovalent copper compound, is preferable from the viewpoint of excellent antiviral properties.
The metal fine particles preferably have an average primary particle size in the range of 10 to 500 nm, particularly 10 to 200 nm. When the average primary particle of the metal fine particles is within the above range, it becomes possible to efficiently exhibit excellent antimicrobial performance. In other words, metal fine particles with such a small average primary particle size can efficiently generate active oxygen due to their high contact rate with oxygen, and can exhibit excellent antimicrobial performance. become. Further, the metal fine particle powder is preferably composed of primary particles having the above-mentioned average primary particle size, and the average secondary particle size is preferably in the range of 100 nm to 500 μm, particularly 100 nm to 100 μm, so that it can be obtained in a powder state. The metal fine particles can be easily dispersed in a dispersion medium, and when mixed with a binder resin to form a paint dispersion, it has excellent handling properties such as coatability.
Note that the average primary particle size in this specification refers to the average of two metal particles with no gaps between them, and the average secondary particle size is the average of the metal particles with no gaps between them. Particles are particles that are packed together and are averaged. Furthermore, the primary particle size can be measured using a scanning electron microscope (SEM), and the secondary particle size can be measured using dynamic light scattering (DLS).
　本発明で用いる金属微粒子は、その表面が、脂肪酸及び／又は脂肪酸エステルで被覆されていることがさらに好適である。これにより、上述した安定化剤で被覆されていることと相俟って、金属微粒子の凝集及び酸化が更に抑制され、優れた抗微生物性及び分散性を得ることができる。
　金属微粒子表面を被覆する脂肪酸としては、カプリル酸、カプリン酸、ラウリン酸、ミリスチン酸，ステアリン酸，オレイン酸，パルミチン酸，ｎ－デカン酸，パラトイル酸，コハク酸，マロン酸，酒石酸，リンゴ酸，グルタル酸，アジピン酸、酢酸等を例示することができ、これらは複数種の組み合わせであってもよいが、特にパルミチン酸、ステアリン酸であることが好適である。
　金属微粒子表面を被覆するエステル化合物は、後述する本発明の金属微粒子粉末の製造方法における原料である脂肪酸及びポリオールに由来するエステル化合物であることが好適であるが、原料由来以外のエステル化合物を配合することもでき、これらは異なるエステル化合物であってもよいが、好適には、原料由来のエステル化合物と同種のものであることが望ましい。
　金属微粒子表面を被覆する好適なエステル化合物としては、上記脂肪酸のエステル化合物と後述するポリオールとのエステル化合物、例えばこれに限定されないが、ジエチレングリコールジステアレート、エチレングリコールジステアレート、プロピレングリコールジステアレート、ポリエチレングリコールジステアレート、ポリプロピレングリコールジステアレート等を挙げることができる。 It is more preferable that the surface of the metal fine particles used in the present invention be coated with a fatty acid and/or a fatty acid ester. This, together with being coated with the above-mentioned stabilizer, further suppresses aggregation and oxidation of the metal fine particles, making it possible to obtain excellent antimicrobial properties and dispersibility.
The fatty acids that coat the surface of the metal fine particles include caprylic acid, capric acid, lauric acid, myristic acid, stearic acid, oleic acid, palmitic acid, n-decanoic acid, paratoic acid, succinic acid, malonic acid, tartaric acid, malic acid, Examples include glutaric acid, adipic acid, acetic acid, etc., and combinations of a plurality of these may be used, but palmitic acid and stearic acid are particularly preferred.
The ester compound that coats the surface of the metal fine particles is preferably an ester compound derived from fatty acids and polyols, which are raw materials in the method for producing metal fine particle powder of the present invention, which will be described later. Although these may be different ester compounds, it is preferable that they are of the same type as the ester compound derived from the raw material.
Suitable ester compounds for coating the surface of the metal fine particles include ester compounds of the above fatty acid ester compounds and polyols described below, such as, but not limited to, diethylene glycol distearate, ethylene glycol distearate, and propylene glycol distearate. , polyethylene glycol distearate, polypropylene glycol distearate, and the like.
　金属微粒子は、分散液中に０．００１～１０質量％、好ましくは０．００２～５質量％、特に０．０５～１質量％の量で含有されていることが好適である。
　また前述した通り、本発明の分散液において、金属微粒子と分散剤及び／又はバインダー樹脂の酸性官能基との反応による金属微粒子のイオン化が抑制されていることから、分散液中の金属微粒子由来の金属イオン濃度は１００ｐｐｍ以下、特に６０ｐｐｍ以下に低減されている。 The metal fine particles are preferably contained in the dispersion in an amount of 0.001 to 10% by weight, preferably 0.002 to 5% by weight, particularly 0.05 to 1% by weight.
Furthermore, as mentioned above, in the dispersion of the present invention, the ionization of the metal fine particles due to the reaction between the metal fine particles and the acidic functional group of the dispersant and/or the binder resin is suppressed. The metal ion concentration is reduced to 100 ppm or less, particularly 60 ppm or less.
［安定化剤］
　本発明に用いる安定化剤は、アスコルビン酸，アスコルビン酸の誘導体及び還元性多価フェノールの少なくとも１種から成る安定化剤であり、金属微粒子のイオン化を抑制可能な還元性を有すると共に、金属微粒子表面に容易に被覆可能な低分子量のものであることが好適である。また後述するように分散液の溶媒が水や水系溶媒の場合、水溶性を示すものであることが好適である。 [Stabilizer]
The stabilizer used in the present invention is a stabilizer composed of at least one of ascorbic acid, a derivative of ascorbic acid, and a reducing polyhydric phenol, and has a reducing property capable of suppressing the ionization of metal fine particles, and has a reducing property that can suppress the ionization of metal fine particles. A low molecular weight material that can be easily coated on a surface is preferred. Further, as described later, when the solvent of the dispersion is water or an aqueous solvent, it is preferable that the solvent exhibits water solubility.
　アスコルビン酸又はその誘導体としては、アスコルビン酸、アスコルビン酸カルシウム、アスコルビン酸ナトリウム、アスコルビン酸－２－グルコシド、２－ｏ－メチルアスコルビン酸、３－ｏ－メチルアスコルビン酸、２－ｏ－エチルアスコルビン酸、３－ｏ－エチルアスコルビン酸、アスコルビン酸－６－パルミテート、アスコルビン酸－６－ステアラート、アスコルビン酸二パルミチン酸エステル、６－ｏ－パルミトイルアスコルビン酸－２－ｏ－リン酸、６－ｏ－アシル－２－ｏ－α－Ｄ－グルコピラノシル－Ｌ－アスコルビン酸、アスコルビン酸－２－リン酸マグネシウム、アスコルビン酸－２－リン酸、アスコルビン酸－２－リン酸ナトリウム、アスコルビン酸－２－硫酸、アスコルビン酸－２－硫酸カリウム、アスコルビン酸－２－硫酸バリウム、アスコルビン酸－２－硫酸エステル二ナトリウム、アスコルビン酸－２－リン酸エステル三ナトリウム等を例示できる。
　また還元性を有する多価フェノールとしては、レゾルシノール、アルキルレゾルシノール、ピロガロール、カテコール、アルキルカテコール、ハイドロキノン、アルキルハイドロキノン、フロログルシノール等の多価フェノールを例示できる。
　本発明においては上記安定化剤の中でも、金属微粒子への被覆性、還元性及び水溶性の観点から、Ｌ－アスコルビン酸を好適に使用することができる。 Ascorbic acid or its derivatives include ascorbic acid, calcium ascorbate, sodium ascorbate, ascorbic acid-2-glucoside, 2-o-methylascorbic acid, 3-o-methylascorbic acid, 2-o-ethylascorbic acid, 3-o-ethyl ascorbic acid, ascorbic acid-6-palmitate, ascorbic acid-6-stearate, ascorbic acid dipalmitate, 6-o-palmitoyl ascorbic acid-2-o-phosphate, 6-o-acyl -2-o-α-D-glucopyranosyl-L-ascorbic acid, magnesium ascorbic acid-2-phosphate, ascorbic acid-2-phosphate, sodium ascorbic acid-2-phosphate, ascorbic acid-2-sulfate, ascorbic acid Examples include potassium acid-2-sulfate, barium ascorbic acid-2-sulfate, disodium ascorbic acid-2-sulfate, and trisodium ascorbic acid-2-phosphate.
Examples of polyhydric phenols having reducing properties include polyhydric phenols such as resorcinol, alkylresorcinol, pyrogallol, catechol, alkylcatechol, hydroquinone, alkylhydroquinone, and phloroglucinol.
In the present invention, among the above-mentioned stabilizers, L-ascorbic acid can be preferably used from the viewpoints of coating properties on metal fine particles, reducing properties, and water solubility.
［酸性官能基を有する分散剤］
　本発明においては、分散液中における金属微粒子の分散性を向上させるために分散剤を含有することが望ましい。本発明の金属微粒子は、上述した安定化剤で被覆されていることから、金属微粒子のイオン化が抑制されているので、酸性官能基を有する分散剤を用いる場合に特に好適である。
　すなわち、分散剤は、カルボキシル基、酸無水物基、スルホン酸基、リン酸基等の酸性の官能基を少なくとも有することが好ましく、また上記酸性官能基と共に、アミノ基、イミノ基、アンモニウム塩基、塩基性窒素原子を有する複素環基等の塩基性官能基を有するスターポリマー構造や、くし型ポリマー構造を有する湿潤分散剤であってもよい。
　分散剤は、酸価が３～１００ｍｇＫＯＨ／ｇ、好ましくは４～３０ｍｇＫＯＨ／ｇ、特に５～２０ｍｇＫＯＨ／ｇの範囲にあることが好適である。上記範囲よりも酸価が小さい場合は、分散液の保存安定性が上記範囲にある場合に比して低下するおそれがあり、一方上記範囲よりも酸価が大きい場合は、上記範囲にある場合に比して塗膜の耐水性が低下するおそれがある。 [Dispersant with acidic functional group]
In the present invention, it is desirable to contain a dispersant in order to improve the dispersibility of metal fine particles in the dispersion. Since the metal fine particles of the present invention are coated with the above-mentioned stabilizer, ionization of the metal fine particles is suppressed, and therefore is particularly suitable when using a dispersant having an acidic functional group.
That is, the dispersant preferably has at least an acidic functional group such as a carboxyl group, an acid anhydride group, a sulfonic acid group, a phosphoric acid group, and in addition to the above acidic functional groups, it also has an amino group, an imino group, an ammonium base, The wetting and dispersing agent may have a star polymer structure having a basic functional group such as a heterocyclic group having a basic nitrogen atom or a comb-shaped polymer structure.
The dispersant preferably has an acid value in the range of 3 to 100 mgKOH/g, preferably 4 to 30 mgKOH/g, particularly 5 to 20 mgKOH/g. If the acid value is lower than the above range, the storage stability of the dispersion may be lower than when it is within the above range, whereas if the acid value is higher than the above range, the storage stability of the dispersion may be lower than when it is within the above range. There is a risk that the water resistance of the coating film will be lower than that of the above.
　本発明における分散剤は、重量平均分子量が１，０００以上であることが好適である。分散剤の重量平均分子量が１，０００未満の場合は、酸性官能基、或いは酸性官能基及び塩基性官能基の十分な立体障害を受けられない。また、これらの官能基が結合する側鎖又は主鎖骨格は、特に制限されず、ポリエステルやポリアクリル、ポリエーテル、ポリオキシアルキレン等から成ることができる。
　上記分散剤の酸性官能基、或いは酸性官能基及び塩基性官能基が、金属微粒子に強固に吸着することにより、金属微粒子に極性が与えられて、金属微粒子同士が電荷により反発すると共に、金属微粒子表面にある程度の長さの修飾基が存在することによって立体障害を形成し、その結果、金属微粒子は溶媒中で凝集や沈降することなく、均一に分散することが可能になると考えられる。
　本発明の金属微粒子含有分散液に好適に使用できる分散剤としては、これに限定されないが、ＤＩＳＰＥＲＢＹＫ－１０２、１８０、１８２、１８４、１９０、１９１、１９２、１９３、１９４Ｎ、１９９、２０６０、２０６１、２０９０、２０９５、２０９６、２１５５、１５４（ビック・ケミー社製）、Ｓｏｋａｌａｎ　ＣＰ９、Ｌｕｐａｓｏｌ　ＦＧ、Ｐｌｕｒｏｎｉｃ　ＰＥ６４００、Ｐｌｕｒｏｎｉｃ　ＰＥ６８００、Ｌｕｔｒｏｐｕｒ　ＭＳＡ、Ｓｏｋａｌａｎ　ＰＡ１１０Ｓ、Ｓｏｋａｌａｎ　ＣＰ１２Ｓ、Ｓｏｋａｌａｎ　ＣＰ１３Ｓ、Ｓｏｋａｌａｎ　ＶＡ　６４Ｐ、Ｌｕｐａｓｏｌ　ＨＦ、Ｐｌｕｒａｆａｃ　ＬＦ３００，Ｐｌｕｒｏｎｉｃ　ＲＰＥ１７４０、Ｐｌｕｒｏｎｉｃ　ＲＰＥ３１１０、Ｄｅｇｒｅｓｓａｌ　ＳＤ４０（ＢＡＳＦ社製）、ＳＣ－０５０５Ｋ、ＡＦＢ－１５２１、ＳＣ－１０１５Ｆ、ＡＫＭ－０５３１、ＡＫＭ－１５１１－６０（日油社製）を挙げることができ、その中でも特に、ＤＩＳＰＥＲＢＹＫ－１０２、１９０、２０６０、が好適である。 The dispersant used in the present invention preferably has a weight average molecular weight of 1,000 or more. When the weight average molecular weight of the dispersant is less than 1,000, sufficient steric hindrance by the acidic functional group or the acidic functional group and the basic functional group cannot be obtained. Furthermore, the side chain or main chain skeleton to which these functional groups are bonded is not particularly limited, and can be made of polyester, polyacrylic, polyether, polyoxyalkylene, or the like.
The acidic functional group or the acidic functional group and the basic functional group of the dispersant strongly adsorb to the metal fine particles, giving the metal fine particles polarity, causing the metal fine particles to repel each other due to electric charge, and causing the metal fine particles to It is thought that the presence of a modifying group of a certain length on the surface forms steric hindrance, and as a result, the metal fine particles can be uniformly dispersed in the solvent without aggregation or sedimentation.
Dispersants that can be suitably used in the metal fine particle-containing dispersion of the present invention include, but are not limited to, DISPERBYK-102, 180, 182, 184, 190, 191, 192, 193, 194N, 199, 2060, 2061, 2090, 2095, 2096, 2155, 154 (manufactured by Big Chemie), Sokalan CP9, Lupasol FG, Pluronic PE6400, Pluronic PE6800, Lutropur MSA, Sokalan PA110S, Sokala n CP12S, Sokalan CP13S, Sokalan VA 64P, Lupasol HF, Plurafac LF300 , Pluronic RPE1740, Pluronic RPE3110, Degressal SD40 (manufactured by BASF), SC-0505K, AFB-1521, SC-1015F, AKM-0531, AKM-1511-60 (manufactured by NOF Corporation), among which In particular, DISPERBYK-102, 190, and 2060 are suitable.
　分散剤は、金属微粒子１００質量部に対して、５０～１０００質量部、特に１００～５００質量部の量で含有されていることが好適である。上記範囲よりも分散剤の量が少ない場合には、金属微粒子の分散性が上記範囲にある場合に比して劣るようになり、一方上記範囲よりも分散剤の量が多くても更なる効果の向上は望めず、経済性に劣るおそれがある。 The dispersant is preferably contained in an amount of 50 to 1000 parts by mass, particularly 100 to 500 parts by mass, per 100 parts by mass of the metal fine particles. If the amount of dispersant is less than the above range, the dispersibility of the metal fine particles will be inferior to that in the above range, while on the other hand, even if the amount of dispersant is greater than the above range, there will be no further effect. There is no hope of improving the performance, and there is a possibility that the economic efficiency will be inferior.
［酸性官能基を有するバインダー樹脂］
　本発明の分散液においては、バインダー樹脂を含有することにより、塗膜を形成可能な分散液（以下、バインダー樹脂を含有する場合には「塗料分散液」ということがある）とすることができる。本発明の金属微粒子は、上述した安定化剤で被覆されていることから、バインダー樹脂が酸性官能基を有する場合でも金属微粒子のイオン化が抑制されているので、カルボキシル基、酸無水物基、スルホン酸基、リン酸基等の酸性の官能基を有するバインダー樹脂を用いる場合に特に好適である。
　バインダー樹脂としては、従来から塗料として使用されていた、フェノール樹脂、エポキシ樹脂、ウレタン樹脂、メラミン樹脂、尿素樹脂、アルキド樹脂、不飽和ポリエステル樹脂、シリコーン樹脂、アクリル系樹脂、ポリエステル樹脂等を例示することができるが、本発明の分散液は、水性分散液であることが好適であることから、水分散性又は水溶性の、アクリル樹脂、ポリエステル樹脂、セルロース樹脂を好適に使用することができる。
　本発明においては電子線硬化型の樹脂を使用することもできるが、特に、硬化剤を使用しない自己架橋型のアクリル系樹脂を好適に使用することができる。
　バインダー樹脂は、金属微粒子１００質量部に対して５０００～１０００００質量部の量で添加することが好適である。 [Binder resin with acidic functional group]
By containing a binder resin, the dispersion of the present invention can form a coating film (hereinafter, when it contains a binder resin, it may be referred to as a "paint dispersion"). . Since the metal fine particles of the present invention are coated with the above-mentioned stabilizer, the ionization of the metal fine particles is suppressed even when the binder resin has an acidic functional group. This is particularly suitable when using a binder resin having an acidic functional group such as an acid group or a phosphoric acid group.
Examples of binder resins include phenol resins, epoxy resins, urethane resins, melamine resins, urea resins, alkyd resins, unsaturated polyester resins, silicone resins, acrylic resins, and polyester resins, which have been conventionally used as paints. However, since the dispersion of the present invention is preferably an aqueous dispersion, water-dispersible or water-soluble acrylic resins, polyester resins, and cellulose resins can be suitably used.
In the present invention, an electron beam curable resin can be used, but a self-crosslinking acrylic resin that does not use a curing agent can be particularly preferably used.
The binder resin is preferably added in an amount of 5,000 to 100,000 parts by mass per 100 parts by mass of the metal fine particles.
＜アクリル樹脂＞
　水分散性又は水溶性のアクリル樹脂としては、カルボキシル基、酸無水物基、スルホン酸基、リン酸基等の酸性官能基を有するエチレン性不飽和モノマーを乳化重合して成るアクリル樹脂エマルジョンを例示できる。具体的には、アクリル酸、メタクリル酸、クロトン酸、イソクロトン酸、プロピルアクリル酸、イソプロピルアクリル酸、イタコン酸、無水マレイン酸及びフマル酸等のカルボキシル基含有エチレン性不飽和モノマーや、ｐ－ビニルベンゼンスルホン酸、ｐ－アクリルアミドプロパンスルホン酸等のスルホン酸含有エチレン性不飽和モノマー、２－ヒドロキシエチルアクリレートのリン酸モノエステル等のリン酸基含有エチレン性不飽和モノマーを例示することができる。これらの中でも、カルボキシル基含有エチレン不飽和モノマーから成るアクリル樹脂エマルジョンであることが好適である。
　またアクリル樹脂エマルジョンは、上記エチレン性不飽和モノマーの他、（メタ）アクリル酸アルキルエステルエステルや水酸基含有エチレン性不飽和モノマーを含有することもできる。 <Acrylic resin>
Examples of water-dispersible or water-soluble acrylic resins include acrylic resin emulsions obtained by emulsion polymerization of ethylenically unsaturated monomers having acidic functional groups such as carboxyl groups, acid anhydride groups, sulfonic acid groups, and phosphoric acid groups. can. Specifically, carboxyl group-containing ethylenically unsaturated monomers such as acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, propyl acrylic acid, isopropyl acrylic acid, itaconic acid, maleic anhydride, and fumaric acid, p-vinylbenzene Examples include sulfonic acid-containing ethylenically unsaturated monomers such as sulfonic acid and p-acrylamidopropanesulfonic acid, and phosphoric acid group-containing ethylenically unsaturated monomers such as phosphoric acid monoester of 2-hydroxyethyl acrylate. Among these, an acrylic resin emulsion comprising a carboxyl group-containing ethylenically unsaturated monomer is preferred.
In addition to the ethylenically unsaturated monomers mentioned above, the acrylic resin emulsion can also contain (meth)acrylic acid alkyl esters and hydroxyl group-containing ethylenically unsaturated monomers.
　アクリル樹脂の酸価は、３～１００ｍｇＫＯＨ／ｇの範囲にあることが好適である。上記範囲よりも低い場合には、分散液の保存安定性が低下するおそれがあると共に、塗膜形成する場合には、十分な硬化性を得ることができないおそれがあり、一方上記範囲よりも高いと重合安定性が低下すると共に、塗膜の耐水性が低下するおそれがある。
　アクリル樹脂の数平均分子量は、特に限定されないが、１００００～５００００の範囲にあることが好ましい。上記範囲よりも小さい場合には、上記範囲にある場合に比して塗膜を形成する場合に十分な塗膜強度が得られないおそれがあり、一方上記範囲よりも大きい場合には、上記範囲にある場合に比して塗料安定性に低下するおそれがある。
　またアクリル樹脂エマルジョンには、アクリル樹脂の分散性を向上するために、アンモニア類、アミン類、或いはアルカリ金属などの塩基性化合物を添加して、カルボン酸の一部が中和されていてもよい。 The acid value of the acrylic resin is preferably in the range of 3 to 100 mgKOH/g. If it is lower than the above range, there is a risk that the storage stability of the dispersion will decrease, and when forming a coating, there is a risk that sufficient curability may not be obtained.On the other hand, if it is lower than the above range This may result in a decrease in polymerization stability and a decrease in the water resistance of the coating film.
The number average molecular weight of the acrylic resin is not particularly limited, but is preferably in the range of 10,000 to 50,000. If it is smaller than the above range, there is a risk that sufficient coating film strength will not be obtained when forming a coating compared to when it is within the above range, while if it is larger than the above range, then There is a risk that the stability of the paint will be lower than that in the case of
Furthermore, in order to improve the dispersibility of the acrylic resin, basic compounds such as ammonia, amines, or alkali metals may be added to the acrylic resin emulsion to neutralize a portion of the carboxylic acid. .
＜ポリエステル樹脂＞
　水分散性又は水溶性のポリエステル樹脂としては、カルボキシル基、酸無水物基、スルホン酸基、リン酸基等の酸性官能基を含有するポリエステル樹脂であり、これらの成分は、ポリエステル樹脂分散体の表面に配位されたものであってもよいが、上記酸性官能基を有するモノマーを共重合成分として、ポリエステル樹脂骨格中に存在するものであることが好適である。
　このようなモノマーとしては、無水フタル酸、無水コハク酸、無水マレイン酸、無水トリメリット酸、無水イタコン酸、無水シトラコン酸等のカルボン酸無水物、５－スルホイソフタル酸，４－スルホナフタレン－２，７－ジカルボン酸、５（４－スルホフェノキシ）イソフタル酸等のスルホン酸含有モノマーの金属塩等を例示できる。
　また酸性官能基を有するビニル系モノマーをポリエステル樹脂にグラフト重合させたアクリル樹脂変性ポリエステル樹脂でもよい。 <Polyester resin>
Water-dispersible or water-soluble polyester resins include polyester resins containing acidic functional groups such as carboxyl groups, acid anhydride groups, sulfonic acid groups, and phosphoric acid groups, and these components are included in the polyester resin dispersion. Although it may be coordinated on the surface, it is preferable that the monomer having the acidic functional group is present in the polyester resin skeleton as a copolymerization component.
Such monomers include carboxylic anhydrides such as phthalic anhydride, succinic anhydride, maleic anhydride, trimellitic anhydride, itaconic anhydride, citraconic anhydride, 5-sulfoisophthalic acid, 4-sulfonaphthalene-2 Examples include metal salts of sulfonic acid-containing monomers such as , 7-dicarboxylic acid, and 5(4-sulfophenoxy)isophthalic acid.
Alternatively, an acrylic resin-modified polyester resin obtained by graft-polymerizing a vinyl monomer having an acidic functional group onto a polyester resin may be used.
　前記酸性官能基を有するモノマーと組み合わせてポリエステル樹脂を形成するモノマーとしてはポリエステル樹脂の重合に通常用いられるものであれば特に限定されない。
　ポリエステル樹脂を構成する多価カルボン酸成分としては、例えばテレフタル酸、イソフタル酸、オルソフタル酸、ナフタレンジカルボン酸等の芳香族ジカルボン酸、コハク酸、グルタル酸、アジピン酸、アゼライン酸、セバシン酸、ドデカンジオン酸、ダイマー酸等の脂肪族ジカルボン酸、（無水）マレイン酸、フマル酸、テルペン－マレイン酸付加体などの不飽和ジカルボン酸、１，４－シクロヘキサンジカルボン酸、テトラヒドロフタル酸、ヘキサヒドロイソフタル酸、１，２－シクロヘキセンジカルボン酸などの脂環族ジカルボン酸、（無水）トリメリット酸、（無水）ピロメリット酸、メチルシクロへキセントリカルボン酸等の３価以上の多価カルボン酸等を挙げることができ、これらの中から１種または２種以上を選択して使用できる。
　ポリエステル樹脂を構成する多価アルコール成分としては、例えば、エチレングリコール、プロピレングリコール（１，２－プロパンジオール）、１，３－プロパンジオール、１，４－ブタンジオール、１，２－ブタンジオール、１，３－ブタンジオール、２－メチル－１，３－プロパンジオール、ネオペンチルグリコール、１，５－ペンタンジオール、１，６－ヘキサンジオール、３－メチル－１，５－ペンタンジオール、２－エチル－２－ブチル－１，３－プロパンジオール、２，４－ジエチル－１，５－ペンタンジオール、１－メチル－１，８－オクタンジオール、３－メチル－１，６－ヘキサンジオール、４－メチル－１，７－ヘプタンジオール、４－メチル－１，８－オクタンジオール、４－プロピル－１，８－オクタンジオール、１，９－ノナンジオール、などの脂肪族グリコール、ジエチレングリコール、トリエチレングリコール、ポリエチレングリコール、ポリプロピレングリコール、ポリテトラメチレングリコール等のエーテルグリコール類、１，４－シクロヘキサンジメタノール、１，３－シクロヘキサンジメタノール、１，２－シクロヘキサンジメタノール、トリシクロデカングリコール類、水添加ビスフェノール類等の脂環族ポリアルコール、トリメチロールプロパン、トリメチロールエタン、ペンタエリスリトール等の３価以上のポリアルコール等を挙げることができ、これらの中から１種または２種以上を選択して使用できる。 The monomer to be combined with the monomer having an acidic functional group to form a polyester resin is not particularly limited as long as it is commonly used in the polymerization of polyester resins.
Examples of the polycarboxylic acid component constituting the polyester resin include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, and naphthalene dicarboxylic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, and dodecanedione. acids, aliphatic dicarboxylic acids such as dimer acid, unsaturated dicarboxylic acids such as (anhydrous) maleic acid, fumaric acid, terpene-maleic acid adducts, 1,4-cyclohexanedicarboxylic acid, tetrahydrophthalic acid, hexahydroisophthalic acid, Examples include alicyclic dicarboxylic acids such as 1,2-cyclohexenedicarboxylic acid, trivalent or higher polyhydric carboxylic acids such as (anhydrous) trimellitic acid, (anhydrous) pyromellitic acid, and methylcyclohexenetricarboxylic acid. , one type or two or more types can be selected and used from these.
Examples of the polyhydric alcohol component constituting the polyester resin include ethylene glycol, propylene glycol (1,2-propanediol), 1,3-propanediol, 1,4-butanediol, 1,2-butanediol, 1 , 3-butanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 2-ethyl- 2-Butyl-1,3-propanediol, 2,4-diethyl-1,5-pentanediol, 1-methyl-1,8-octanediol, 3-methyl-1,6-hexanediol, 4-methyl- Aliphatic glycols such as 1,7-heptanediol, 4-methyl-1,8-octanediol, 4-propyl-1,8-octanediol, 1,9-nonanediol, diethylene glycol, triethylene glycol, polyethylene glycol , ether glycols such as polypropylene glycol and polytetramethylene glycol, 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,2-cyclohexanedimethanol, tricyclodecane glycols, water-added bisphenols, etc. Examples include alicyclic polyalcohols, trivalent or higher polyalcohols such as trimethylolpropane, trimethylolethane, and pentaerythritol, and one or more of these can be selected and used.
　ポリエステル樹脂の酸価は、３～１００ｍｇＫＯＨ／ｇの範囲にあることが好適である。上記範囲よりも低い場合には、上記範囲にある場合に比して分散液の保存安定性が低下するおそれがあると共に、塗膜形成する場合には十分な硬化性を得ることができないおそれがある。一方上記範囲よりも多い場合には、上記範囲にある場合に比して重合安定性が低下すると共に、塗膜の耐水性が低下するおそれがある。
　ポリエステル樹脂の数平均分子量は、特に限定されないが、５０００～３００００の範囲にあることが好適である。上記範囲よりも小さい場合には、上記範囲にある場合に比して塗膜を形成する場合に十分な塗膜強度が得られないおそれがあり、一方上記範囲よりも大きい場合には、上記範囲にある場合に比して塗料安定性に低下するおそれがある。 The acid value of the polyester resin is preferably in the range of 3 to 100 mgKOH/g. If it is lower than the above range, there is a risk that the storage stability of the dispersion will be lower than when it is within the above range, and when forming a coating, there is a risk that sufficient curability may not be obtained. be. On the other hand, if the amount exceeds the above range, the polymerization stability may be lowered compared to the case where the amount is within the above range, and the water resistance of the coating film may also be lowered.
The number average molecular weight of the polyester resin is not particularly limited, but is preferably in the range of 5,000 to 30,000. If it is smaller than the above range, there is a risk that sufficient coating film strength will not be obtained when forming a coating compared to when it is within the above range, while if it is larger than the above range, then There is a risk that the stability of the paint will be lower than that in the case of
＜セルロース樹脂＞
　セルロース樹脂としては、セルロース及び／又はセルロース誘導体を例示でき、セルロース誘導体としては、セルロースの水酸基の一部又は全部がエーテル化されたセルロースエーテル、セルロースの水酸基の一部又は全部がエステル化されたセルロースエステル等を挙げることができる。
　このようなセルロース樹脂としては、例えば、メチルセルロース、ヒドロキシエチルセルロース、ヒドロキシプロピルセルロース、ヒドロキシエチルメチルセルロース、ヒドロキシプロピルメチルセルロース、ヒドロキシブチルメチルセルロース、エチルヒドロキシエチルセルロース、カルボキシメチルセルロース、カルボキシエチルセルロース、カルボキシメチルヒドロキシエチルセルロース等のセルロースエーテル、セルロースアセテート、セルロースプロピオネート、セルロースブチレート、セルロースアセテートプロピオネート、セルロースアセテートブチレート等のセロースエステルを挙げることができ、これらの中から１種または２種以上を選択して使用できる。
　これらの中でも、酸性官能基を有することが好適であることから、カルボキシメチルセルロース、カルボキシエチルセルロース等のカルボキシアルキルセルロースを好適に使用できる。
　セルロース樹脂の数平均分子量は、特に限定されないが、１００００～２０００００の範囲にあることが好適である。 <Cellulose resin>
Examples of cellulose resins include cellulose and/or cellulose derivatives, and examples of cellulose derivatives include cellulose ether in which some or all of the hydroxyl groups of cellulose are etherified, and cellulose in which some or all of the hydroxyl groups of cellulose are esterified. Examples include esters.
Examples of such cellulose resins include cellulose ethers such as methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxyethylmethylcellulose, hydroxypropylmethylcellulose, hydroxybutylmethylcellulose, ethylhydroxyethylcellulose, carboxymethylcellulose, carboxyethylcellulose, and carboxymethylhydroxyethylcellulose; Examples include cellose esters such as cellulose acetate, cellulose propionate, cellulose butyrate, cellulose acetate propionate, and cellulose acetate butyrate, and one or more types thereof can be selected and used.
Among these, carboxyalkylcelluloses such as carboxymethylcellulose and carboxyethylcellulose can be preferably used because they preferably have acidic functional groups.
The number average molecular weight of the cellulose resin is not particularly limited, but is preferably in the range of 10,000 to 200,000.
［分散媒］
　本発明の分散液において、金属微粒子を分散させる分散媒としては以下の溶媒を使用することができ、後述する金属微粒子粉末を回収した後に、メタノール、エタノール、イソプロピルアルコール等のアルコール系溶剤、蒸留水、イオン交換水、純水等の各種水溶媒、酢酸メチル、酢酸エチル、酢酸ブチル等のエステル系溶媒、ヘキサン、ヘプタン、トルエン、キシレン、シクロヘキサン等の炭化水素系溶媒、メチルイソブチルケトン、メチルエチルケトン、シクロヘキサノン等のケトン溶媒、エチレングリコール、ジエチレングリコール、エチレングリコール、ポリエチレングリコール、ポリプロピレングリコール、グリセリン等のポリオール系溶剤等に分散させて用いることができる。これら分散媒の中でも、水溶媒、又は水系の混合溶媒等を好適に使用することができ、特に水、又は水とアルコール等の両親媒性の有機溶剤との混合溶媒等を好適に使用することができる。 [Dispersion medium]
In the dispersion of the present invention, the following solvents can be used as the dispersion medium for dispersing the metal fine particles. , various water solvents such as ion-exchanged water and pure water, ester solvents such as methyl acetate, ethyl acetate, and butyl acetate, hydrocarbon solvents such as hexane, heptane, toluene, xylene, and cyclohexane, methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone. It can be used by dispersing it in a ketone solvent such as ethylene glycol, diethylene glycol, ethylene glycol, polyethylene glycol, polypropylene glycol, or a polyol solvent such as glycerin. Among these dispersion media, aqueous solvents or aqueous mixed solvents can be preferably used, and particularly water or a mixed solvent of water and an amphipathic organic solvent such as alcohol is preferably used. I can do it.
　本発明の分散液においては、上述した種々の分散媒中に、金属微粒子が凝集や沈降することなく、長期にわたって均一に分散可能であるが、抗微生物性と分散性のバランスの観点から、分散液中に１０質量％以下の量、特に０．００１～１質量％の量で金属微粒子を含有することが好ましい。 In the dispersion liquid of the present invention, metal fine particles can be uniformly dispersed in the various dispersion media described above for a long period of time without agglomeration or sedimentation. It is preferable that the liquid contains metal fine particles in an amount of 10% by mass or less, particularly 0.001 to 1% by mass.
［その他］
　本発明の分散液においては、上記金属微粒子、酸性官能基を有する分散剤及び／又は酸性官能基を有するバインダー樹脂、安定化剤及び溶媒以外に、酸化防止剤、界面活性剤、硬化剤、触媒、重合開始剤等、必要に応じて他の成分を含有することもできる。
　例えば、分散液が、バインダー樹脂としてカルボキシル基含有ポリエステル樹脂を有する塗料分散液である場合には、カルボキシル基と反応可能な官能基を有するアミノ樹脂やレゾール型フェノール樹脂等の硬化剤を公知の処方で含有することもできる。 [others]
In the dispersion of the present invention, in addition to the metal fine particles, a dispersant having an acidic functional group and/or a binder resin having an acidic functional group, a stabilizer and a solvent, an antioxidant, a surfactant, a curing agent, a catalyst, etc. , a polymerization initiator, and other components as necessary.
For example, when the dispersion liquid is a paint dispersion liquid having a carboxyl group-containing polyester resin as a binder resin, a curing agent such as an amino resin or a resol type phenol resin having a functional group capable of reacting with a carboxyl group is added to a known formulation. It can also be contained.
（分散液の製造方法）
　本発明の分散液は以下の製造方法によって調製することができる。
（１）第一工程
　脂肪酸金属塩をポリオールに添加し、これを加熱することにより、脂肪酸及び／又はこの脂肪酸とポリオールのエステル化合物が表面に被覆された金属微粒子を含むポリオール溶液を調製する。加熱温度は、用いる脂肪酸金属塩の分解開始温度未満の温度であり、加熱混合の時間は、６０～３６０分であることが好適である。加熱温度が脂肪酸金属塩の分解開始温度以上であると、脂肪酸及び／又はエステル化合物が金属微粒子に被覆されず、金属微粒子は酸化されるおそれがある。尚、分解開始温度は、ＪＩＳ　Ｋ　７１２０により定義されている。 (Method for manufacturing dispersion)
The dispersion of the present invention can be prepared by the following manufacturing method.
(1) First step A fatty acid metal salt is added to a polyol and heated to prepare a polyol solution containing metal fine particles whose surfaces are coated with a fatty acid and/or an ester compound of the fatty acid and the polyol. The heating temperature is preferably lower than the decomposition starting temperature of the fatty acid metal salt used, and the heating and mixing time is preferably 60 to 360 minutes. If the heating temperature is equal to or higher than the decomposition start temperature of the fatty acid metal salt, the fatty acid and/or ester compound will not be coated on the metal fine particles, and the metal fine particles may be oxidized. Note that the decomposition start temperature is defined by JIS K 7120.
　脂肪酸金属塩の配合量は、ポリオール当たり０．１～５質量％の範囲にあることが好ましい。上記範囲よりも脂肪酸金属塩の量が少ない場合には、上記範囲にある場合に比して十分な抗微生物性を分散液に付与することができないおそれがある。一方上記範囲よりも脂肪酸金属塩の量が多い場合には上記範囲にある場合に比して、経済性が劣る。
　ポリオールとしては、エチレングリコール、ジエチレングリコール、トリエチレングリコール、ポリエチレングリコール、ポリプロピレングリコール、グリセリンを挙げることができ、後述する低沸点溶媒との組み合わせで適宜選択する。 The amount of fatty acid metal salt blended is preferably in the range of 0.1 to 5% by mass based on the polyol. When the amount of the fatty acid metal salt is less than the above range, there is a possibility that sufficient antimicrobial properties cannot be imparted to the dispersion compared to when the amount is within the above range. On the other hand, when the amount of the fatty acid metal salt is greater than the above range, the economical efficiency is inferior to when the amount is within the above range.
Examples of the polyol include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, and glycerin, which are appropriately selected in combination with the low-boiling solvent described below.
（２）第二工程
　次いで、脂肪酸及び／又は該脂肪酸とポリオールのエステル化合物で被覆された金属微粒子を含むポリオール溶液と低沸点溶媒とを混合し、混合液を調製する。
　低沸点溶媒は、ポリオールに対して１０～２００質量％の量で添加することが好ましい。
　低沸点溶媒としては、酢酸メチル、酢酸エチル、酢酸ブチル等のエステル類、ヘキサン、ヘプタン、トルエン、キシレン、シクロヘキサン等の炭化水素類、メチルイソブチルケトン、メチルエチルケトン、シクロヘキサノン等のケトン類等の低沸点溶媒を例示することができるが、エステル系溶媒が好ましく、中でも、酢酸ブチル、酢酸エチル、メチルイソブチルケトンを好適に使用できる。低沸点溶媒は、ポリオールと相溶しないことが重要であり、ポリオールと低沸点溶媒の溶解度パラメータ（Ｓｐ値）の差が３以上となるように組み合わせることが好ましい。
　好適には、ポリオールとしてジエチレングリコール（Ｓｐ値：１２．６）を用いた場合には、低沸点溶媒として酢酸ブチル（Ｓｐ値：８．４）を用いることが望ましい。 (2) Second step Next, a polyol solution containing fine metal particles coated with a fatty acid and/or an ester compound of the fatty acid and a polyol is mixed with a low boiling point solvent to prepare a mixed solution.
The low boiling point solvent is preferably added in an amount of 10 to 200% by mass based on the polyol.
Low boiling point solvents include esters such as methyl acetate, ethyl acetate, and butyl acetate, hydrocarbons such as hexane, heptane, toluene, xylene, and cyclohexane, and ketones such as methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone. For example, ester solvents are preferred, and among them, butyl acetate, ethyl acetate, and methyl isobutyl ketone are preferably used. It is important that the low boiling point solvent is not compatible with the polyol, and it is preferable to combine the polyol and the low boiling point solvent so that the difference in solubility parameter (Sp value) between the polyol and the low boiling point solvent is 3 or more.
Preferably, when diethylene glycol (Sp value: 12.6) is used as the polyol, it is desirable to use butyl acetate (Sp value: 8.4) as the low boiling point solvent.
（３）第三工程
　上記混合液を、０～４０℃の温度で３０～１２０分間静置することにより、ポリオール及び低沸点溶媒を相分離させる。混合液が相分離されると、混合液中に存在していた過剰な脂肪酸金属塩、遊離脂肪酸又は脂肪酸のエステル化合物、或いは不純物が低沸点溶媒側に抽出され、脂肪酸及び／又は該脂肪酸とポリオールのエステル化合物で被覆された金属微粒子はポリオール中に沈殿した状態で残存する。
　前述した第一工程で、金属微粒子には脂肪酸とポリオールのエステル化合物が充分に被覆されていることから、低沸点溶媒にエステル化合物をあえて配合する必要はないが、第一工程での被覆量によっては、配合することもできる。
　次いで、相分離された混合液から低沸点溶媒を除去することにより、ポリオール中に脂肪酸及び／又は該脂肪酸とポリオールのエステル化合物で被覆された金属微粒子を含む溶液が得られる。
　低沸点溶媒の除去は、デカンテーション、抽出等の、従来公知の分離方法によって行うことができる。
　またポリオールから金属微粒子粉末の回収は、膜分離、遠心分離、デカンテーション等、従来公知の分離方法により行うことができ、これに限定されないが、膜分離によることが好適である。
　分離された金属微粒子は、水、或いは酢酸ブチルやヘキサン等の低沸点溶媒で十分洗浄した後、４０～５０℃で６０～３６０分加熱乾燥して水分を十分に除去することにより、脂肪酸及びエステル化合物の被覆量が０．１～２０質量％である乾燥状態の金属微粒子粉末を得ることができる。 (3) Third step The above-mentioned mixed solution is allowed to stand at a temperature of 0 to 40°C for 30 to 120 minutes to cause phase separation of the polyol and the low boiling point solvent. When the mixed liquid is phase separated, excess fatty acid metal salts, free fatty acids, fatty acid ester compounds, or impurities present in the mixed liquid are extracted to the low boiling point solvent side, and the fatty acid and/or the fatty acid and the polyol are extracted. The metal fine particles coated with the ester compound remain in the polyol in a precipitated state.
In the first step mentioned above, the metal particles are sufficiently coated with the ester compound of fatty acid and polyol, so there is no need to intentionally blend the ester compound into the low boiling point solvent, but depending on the amount of coating in the first step, can also be blended.
Next, by removing the low boiling point solvent from the phase-separated mixture, a solution containing fine metal particles coated with a fatty acid and/or an ester compound of the fatty acid and the polyol in a polyol is obtained.
Removal of the low boiling point solvent can be performed by conventionally known separation methods such as decantation and extraction.
Further, recovery of the metal fine particles from the polyol can be performed by a conventionally known separation method such as membrane separation, centrifugation, decantation, etc., but is not limited thereto, but membrane separation is preferable.
The separated metal fine particles are thoroughly washed with water or a low boiling point solvent such as butyl acetate or hexane, and then heated and dried at 40 to 50°C for 60 to 360 minutes to sufficiently remove moisture, thereby removing fatty acids and esters. It is possible to obtain dry metal fine particle powder having a compound coating amount of 0.1 to 20% by mass.
（４）第四工程
　水等の分散媒に、必要により前述した分散剤を添加して混合した後、上記金属微粒子粉末を添加して混合する。分散剤は、金属微粒子１００質量部に対して５０～１０００質量部の量で添加することが好適である。この際、超音波分散機、ホモジナイザー、ミキサー等を用いて金属微粒子が均一に分散されるように分散処理を施すことが好ましい。
　次いで、Ｌ－アスコルビン酸等の安定化剤を、金属微粒子１００質量部に対して１５０質量部以上の量で添加した後、更に混合・分散処理を行うことにより、金属微粒子及び安定化剤、分散剤を含有する分散液を得ることができる。 (4) Fourth step After adding and mixing the above-mentioned dispersant to a dispersion medium such as water, if necessary, the metal fine particle powder is added and mixed. The dispersant is preferably added in an amount of 50 to 1000 parts by mass per 100 parts by mass of the metal fine particles. At this time, it is preferable to perform a dispersion treatment using an ultrasonic disperser, a homogenizer, a mixer, etc. so that the metal fine particles are uniformly dispersed.
Next, a stabilizer such as L-ascorbic acid is added in an amount of 150 parts by mass or more per 100 parts by mass of the metal fine particles, and further mixing and dispersion treatment is performed to form the metal fine particles, the stabilizer, and the dispersion. A dispersion containing the agent can be obtained.
（５）第五工程
　本発明の分散液において、さらに酸性官能基を含有するバインダー樹脂を含有する塗料分散液とする場合には、上述した第四工程で調製された分散液と、バインダー樹脂及び必要により硬化剤とを均一混合することにより調製する。バインダー樹脂は、金属微粒子１００質量部に対して５０００～１０００００質量部の量で添加することが好適である。 (5) Fifth step In the dispersion of the present invention, when the coating dispersion further contains a binder resin containing an acidic functional group, the dispersion prepared in the fourth step described above, the binder resin and It is prepared by uniformly mixing with a curing agent if necessary. The binder resin is preferably added in an amount of 5,000 to 100,000 parts by mass per 100 parts by mass of the metal fine particles.
（第二の製造方法）
　低沸点溶媒中に、安定化剤を含有する金属微粒子の製造方法は上述した製造方法の他、以下の方法によっても調製することができる。
　すなわち、上述した第一の製造方法における第一の工程において、脂肪酸金属塩に代えて、脂肪酸及び金属化合物の組み合わせを添加する以外は第一の製造方法と同様に行うことにより、脂肪酸及び／又は該脂肪酸のエステル化合物で被覆した金属微粒子の分散液を調製し、次いで上述した第二工程～第四工程を経ることにより、更に安定化剤を含有する金属微粒子分散液を得ることができる。 (Second manufacturing method)
Metal fine particles containing a stabilizer in a low boiling point solvent can be produced by the following method in addition to the above-mentioned production method.
That is, in the first step of the first production method described above, fatty acids and/or By preparing a dispersion of metal fine particles coated with the fatty acid ester compound and then passing through the second to fourth steps described above, a metal fine particle dispersion further containing a stabilizer can be obtained.
（他の製造方法）
　上記第一の製造方法及び第二の製造方法によれば、Ｌ－アスコルビン酸等の安定化剤を含有する金属微粒子含有分散液を効率よく製造することができるが、以下の方法によっても安定化剤を含有する金属微粒子粉末を製造することができる。
　すなわち、前述した第一の製造方法の第一工程で得られた脂肪酸及び／又は該脂肪酸とポリオールのエステル化合物で被覆された金属微粒子を含むポリオール溶液をそのまま使用し、この溶液から回収した金属微粒子を使用してもよい。その場合、過剰の脂肪酸金属塩、或いは遊離の脂肪酸又はエステル化合物の他、不純物のためにポリオール分散液の粘度が大きく、そのまま低沸点溶媒を除去することが困難なので、エタノール等で希釈して粘度を下げてから溶媒を除去する。
　また脂肪酸金属塩を不活性雰囲気下で加熱して還元した後、前述した安定化剤、或いは安定化剤とエステル化合物を添加して、これを粉砕混合することによって、少なくとも安定化剤で被覆された金属微粒子粉末、或いは安定化剤とエステル化合物で被覆された金属微粒子粉末を製造し、これと酸性官能基を有する分散剤及び／又は酸性官能基を有するバインダー樹脂とを溶媒に混合して調製することもできる。 (Other manufacturing methods)
According to the first production method and the second production method described above, it is possible to efficiently produce a metal fine particle-containing dispersion containing a stabilizer such as L-ascorbic acid, but stabilization can also be achieved by the following method. A fine metal particle powder containing the agent can be produced.
That is, the polyol solution containing the metal fine particles coated with the fatty acid and/or the ester compound of the fatty acid and the polyol obtained in the first step of the first manufacturing method described above is used as it is, and the metal fine particles recovered from this solution are used. may be used. In that case, the viscosity of the polyol dispersion is high due to excess fatty acid metal salts, free fatty acids or ester compounds, and other impurities, and it is difficult to remove the low boiling point solvent as it is, so dilute it with ethanol etc. to reduce the viscosity. After lowering the temperature, remove the solvent.
In addition, after reducing the fatty acid metal salt by heating in an inert atmosphere, adding the above-mentioned stabilizer or a stabilizer and an ester compound, and pulverizing and mixing it, it is possible to coat the fatty acid metal salt with at least the stabilizer. Prepared by producing metal fine particle powder coated with a stabilizer and an ester compound, and mixing this with a dispersant having an acidic functional group and/or a binder resin having an acidic functional group in a solvent. You can also.
（分散液の用途）
　本発明の分散液は、不織布や樹脂フィルム或いは繊維製品等の基材に噴霧してそのまま使用することもでき、上記基材表面に本発明の分散液からなる被膜を形成した成形体とすることができる。またバインダー樹脂を含有する塗料分散液とし、これを上記基材に塗工した後、焼付乾燥して被膜（塗膜）を形成して成る成形体とすることもできる。更に上記塗料分散液からフィルム、シート、不織布、繊維等の成形体を直接成形して使用することもできる。 (Applications of dispersion)
The dispersion of the present invention can also be used as it is by spraying it onto a base material such as a nonwoven fabric, a resin film, or a textile product, and can be used as a molded article with a coating made of the dispersion of the present invention formed on the surface of the base material. I can do it. Alternatively, a molded article can be obtained by preparing a paint dispersion containing a binder resin, applying this to the above-mentioned base material, and then baking and drying it to form a coating (coating film). Furthermore, molded objects such as films, sheets, nonwoven fabrics, fibers, etc. can also be formed directly from the above coating dispersion and used.
＜金属銅ナノ粒子の合成＞
　ジエチレングリコールに対してステアリン酸銅（ＩＩ）２．５質量％を加え、加熱攪拌した。１９０℃に達した時点から２時間加熱した後、１１０℃まで冷却し、酢酸ブチルを加え約１分間攪拌した。その後、静置しジエチレングリコール層と酢酸ブチル層を分離させ、酢酸ブチル層を除去し、金属銅微粒子を含むジエチレングリコール溶液を得た。このジエチレングリコール分散液を孔径１０μｍメンブレンフィルターで吸引濾過し、水洗後、５０℃で２時間乾燥されることで金属銅微粒子粉末を得た。 <Synthesis of metallic copper nanoparticles>
2.5% by mass of copper(II) stearate was added to diethylene glycol, and the mixture was heated and stirred. After heating for 2 hours after reaching 190°C, the mixture was cooled to 110°C, and butyl acetate was added and stirred for about 1 minute. Thereafter, the mixture was allowed to stand still to separate the diethylene glycol layer and the butyl acetate layer, and the butyl acetate layer was removed to obtain a diethylene glycol solution containing metallic copper fine particles. This diethylene glycol dispersion was suction-filtered through a membrane filter with a pore size of 10 μm, washed with water, and then dried at 50° C. for 2 hours to obtain metallic copper fine particle powder.
＜金属銅微粒子及び分散剤を含む、分散液の作製＞
（実施例１）
　蒸留水に、分散剤としてＤＩＰＥＲＢＹＫ－１９０（ビック・ケミー社製、酸価１０ｍｇＫＯＨ／ｇ）を金属銅微粒子１００質量部に対して１００質量部になるように加えて攪拌した。次いで、上記で作製した金属銅微粒子粉末を金属銅成分が０．１質量％になるように添加し、１０分間超音波処理を行った。その後、Ｌ－アスコルビン酸を金属銅微粒子１００質量部に対して１０００質量部になるように添加し、さらに１０分間超音波処理を行うことで、アスコルビン酸含有金属銅微粒子分散液を得た。 <Preparation of dispersion liquid containing metallic copper fine particles and dispersant>
(Example 1)
DIPERBYK-190 (manufactured by BYK Chemie, acid value 10 mgKOH/g) as a dispersant was added to distilled water in an amount of 100 parts by mass based on 100 parts by mass of metallic copper fine particles, and the mixture was stirred. Next, the metallic copper fine particle powder produced above was added so that the metallic copper component was 0.1% by mass, and ultrasonication was performed for 10 minutes. Thereafter, L-ascorbic acid was added in an amount of 1000 parts by mass based on 100 parts by mass of metallic copper microparticles, and ultrasonication was further performed for 10 minutes to obtain an ascorbic acid-containing metallic copper microparticle dispersion.
（実施例２）
　Ｌ－アスコルビン酸の割合を金属銅微粒子１００質量部に対して２００質量部に変更した以外は実施例１と同様に分散液を作製した。 (Example 2)
A dispersion liquid was prepared in the same manner as in Example 1, except that the proportion of L-ascorbic acid was changed to 200 parts by mass per 100 parts by mass of metallic copper fine particles.
（実施例３）
　Ｌ－アスコルビン酸の割合を金属銅微粒子１００質量部に対して５００質量部に変更した以外は実施例１と同様に分散液を作製した。 (Example 3)
A dispersion liquid was prepared in the same manner as in Example 1 except that the proportion of L-ascorbic acid was changed to 500 parts by mass per 100 parts by mass of metallic copper fine particles.
（実施例４）
　Ｌ－アスコルビン酸を、３－ｏ－エチル－Ｌ－アスコルビン酸に変更し、金属銅微粒子１００質量部に対して６０００質量部加えた以外は実施例１と同様に分散液を作製した。 (Example 4)
A dispersion liquid was prepared in the same manner as in Example 1 except that L-ascorbic acid was changed to 3-o-ethyl-L-ascorbic acid and 6000 parts by mass was added to 100 parts by mass of metal copper fine particles.
（実施例５）
　Ｌ－アスコルビン酸を、還元性を有する多価フェノールであるピロガロールに変更した以外は実施例１と同様に分散液を作製した。 (Example 5)
A dispersion liquid was prepared in the same manner as in Example 1 except that L-ascorbic acid was changed to pyrogallol, which is a polyhydric phenol having reducing properties.
（比較例１）
　Ｌ－アスコルビン酸を加えなかった以外は実施例１と同様に分散液を作製した。 (Comparative example 1)
A dispersion was prepared in the same manner as in Example 1 except that L-ascorbic acid was not added.
（比較例２）
　Ｌ－アスコルビン酸およびＤＩＳＰＥＲＢＹＫ－１９０を加えなかった以外は、実施例１と同様に分散液を作製した (Comparative example 2)
A dispersion was prepared in the same manner as in Example 1, except that L-ascorbic acid and DISPERBYK-190 were not added.
（比較例３）
　Ｌ－アスコルビン酸の割合を金属銅微粒子１００質量部に対して１００質量部に変更した以外は実施例１と同様に分散液を作製した。 (Comparative example 3)
A dispersion liquid was prepared in the same manner as in Example 1, except that the proportion of L-ascorbic acid was changed to 100 parts by mass relative to 100 parts by mass of metallic copper fine particles.
（比較例４）
　Ｌ－アスコルビン酸をクエン酸に変更した以外は実施例１と同様に分散液を作製した。 (Comparative example 4)
A dispersion liquid was prepared in the same manner as in Example 1 except that citric acid was used instead of L-ascorbic acid.
（比較例５）
　Ｌ－アスコルビン酸をホスフィン酸ナトリウム１水和物に変更した以外は実施例１と同様に分散液を作製した。 (Comparative example 5)
A dispersion liquid was prepared in the same manner as in Example 1 except that L-ascorbic acid was changed to sodium phosphinate monohydrate.
（比較例６）
　Ｌ－アスコルビン酸をＤ－マルトース１水和物に変更した以外は実施例１と同様に分散液を作製した。 (Comparative example 6)
A dispersion liquid was prepared in the same manner as in Example 1 except that L-ascorbic acid was changed to D-maltose monohydrate.
＜ゼータ電位測定方法＞
　ゼータ電位は、大塚電子（株）社製ゼータ電位・粒径・分子量測定システム　ＥＬＳＺ－２０００ＺＳを用いた。測定には、標準セルユニットを用い、測定電圧６０Ｖで実施した。Ｌ－アスコルビン酸を加えなかった比較例１と比べて、ゼータ電位の絶対値が変化すれば、Ｌ－アスコルビン酸が金属銅微粒子表面に作用していることを示している。実施例１～５、比較例１～６について測定した。結果を表１に示す。 <Zeta potential measurement method>
For the zeta potential, a zeta potential/particle size/molecular weight measurement system ELSZ-2000ZS manufactured by Otsuka Electronics Co., Ltd. was used. The measurement was carried out using a standard cell unit at a measurement voltage of 60V. A change in the absolute value of the zeta potential compared to Comparative Example 1 in which no L-ascorbic acid was added indicates that L-ascorbic acid is acting on the surface of the metallic copper fine particles. Measurements were made for Examples 1 to 5 and Comparative Examples 1 to 6. The results are shown in Table 1.
＜分散液の外観評価＞
　安定化剤を用いない場合では、時間経過とともに水色に変化する現象が確認されるが、これは、分散液中の金属銅微粒子がイオン化している、すなわち、抗微生物性能が失われていることを意味している。そこで、本願の安定化剤を併用することにより金属銅微粒子のイオン化が抑制可能かどうかを、以下の方法で確認した。
　作製した分散液を室温で３日間静置して、分散液の色味を目視で確認した。分散液の色味が水色に変化していないものを〇（金属銅微粒子が維持されている）、色味が水色に変化したものを×（金属銅微粒子がイオン化している）とした。結果を表１に示す。 <Appearance evaluation of dispersion>
When no stabilizer is used, a phenomenon in which the dispersion turns light blue over time is observed, but this indicates that the metallic copper fine particles in the dispersion are ionized, that is, the antimicrobial performance has been lost. It means. Therefore, it was confirmed by the following method whether the ionization of metallic copper fine particles could be suppressed by using the stabilizer of the present application in combination.
The prepared dispersion was allowed to stand at room temperature for 3 days, and the color of the dispersion was visually confirmed. A case where the color of the dispersion liquid did not change to light blue was rated as ○ (metallic copper fine particles were maintained), and a case where the color changed to light blue was rated as × (metallic copper fine particles were ionized). The results are shown in Table 1.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
＜金属銅微粒子、分散剤及びバインダー樹脂を含む、塗料分散液の作製＞
（実施例６～１０）
　バインダー樹脂Ａとして酸性官能基を有するアクリル系樹脂エマルジョン４ｍｌと、実施例１～５で作製した分散液１ｍｌをそれぞれ混合することで、金属銅微粒子、分散剤及びバインダー樹脂を含む、塗料分散液を得た。 <Preparation of paint dispersion containing metallic copper fine particles, dispersant, and binder resin>
(Examples 6 to 10)
By mixing 4 ml of an acrylic resin emulsion having an acidic functional group as binder resin A and 1 ml of the dispersions prepared in Examples 1 to 5, a paint dispersion containing metallic copper fine particles, a dispersant, and a binder resin was prepared. Obtained.
（比較例７～１２）
　バインダー樹脂Ａとして酸性官能基を有するアクリル系樹脂エマルジョン４ｍｌと、比較例１～６で作製した分散液１ｍｌをそれぞれ混合することで、金属銅微粒子、分散剤及びバインダー樹脂を含む、塗料分散液を得た。 (Comparative Examples 7 to 12)
By mixing 4 ml of an acrylic resin emulsion having an acidic functional group as binder resin A and 1 ml of the dispersions prepared in Comparative Examples 1 to 6, a paint dispersion containing metallic copper fine particles, a dispersant, and a binder resin was prepared. Obtained.
（実施例１１）
　バインダー樹脂Ｂ（自己架橋型アクリル酸エステル乳化重合物）の固形分に対して金属成分濃度が０．１質量％になるように、実施例１の金属銅微粒子分散液４．０質量％と、バインダー樹脂Ｂ８．９質量％、純水８６．６質量％、アスコルビン酸０．５質量％をそれぞれ混合して塗料分散液を作製した。 (Example 11)
4.0% by mass of the metallic copper fine particle dispersion of Example 1 so that the metal component concentration was 0.1% by mass based on the solid content of binder resin B (self-crosslinking acrylic acid ester emulsion polymer), A paint dispersion was prepared by mixing 8.9% by mass of binder resin B, 86.6% by mass of pure water, and 0.5% by mass of ascorbic acid.
＜Ｘ線回折測定＞
　実施例６及び比較例７，１０，１１で得られた塗料分散液について、それぞれ調製から、３か月経過後のＸ線回折（ＸＲＤ）によるチャートを図１に示す。実施例６からなる塗料分散液は３か月経過後でも金属銅微粒子が存在していることがわかる。
　また実施例６及び比較例７で得られた塗料分散液について、調製直後及び３日経過後のＸ線回折によるチャートを図２に示す。Ｌ－アスコルビン酸を添加しない以外は実施例６と同様の比較例７の塗料分散液は、３日経過後には既に金属銅微粒子の回折ピークは検出されなかった。 <X-ray diffraction measurement>
FIG. 1 shows X-ray diffraction (XRD) charts of the paint dispersions obtained in Example 6 and Comparative Examples 7, 10, and 11 after 3 months of preparation. It can be seen that metallic copper fine particles are present in the paint dispersion prepared in Example 6 even after 3 months have elapsed.
Further, FIG. 2 shows X-ray diffraction charts of the paint dispersions obtained in Example 6 and Comparative Example 7 immediately after preparation and after 3 days. In the paint dispersion of Comparative Example 7, which was the same as Example 6 except that L-ascorbic acid was not added, no diffraction peak of metallic copper fine particles was detected after 3 days.
＜塗料分散液の外観評価＞
　安定化剤を用いない場合では、時間経過とともに水色に変化する現象が確認された。これは、塗料分散液中の金属銅微粒子がイオン化している、すなわち、抗微生物性能が失われていることを意味している。
　そこで、本願の安定化剤を併用するにより金属銅微粒子のイオン化が抑制可能かどうかを、以下の方法で確認した。
　作製した塗料分散液を室温で３日間静置した。続いて遠心分離により、塗料分散液中に含まれる金属銅微粒子を完全に沈降させた。その後、塗料分散液の色味を目視で確認した。塗料分散液の色味が水色に変化していないものを〇（金属銅微粒子成分が維持されている）、色味が水色に変化したものを×（金属銅微粒子成分がイオン化している）とした。実施例６～１１、比較例７～１２についてそれぞれ確認した。結果を表２に示すと共に、実施例６及び比較例７の塗料分散液の調製直後及び３日経過後の写真を図３に示した。 <Appearance evaluation of paint dispersion>
When no stabilizer was used, a phenomenon in which the color changed to light blue over time was observed. This means that the metallic copper fine particles in the paint dispersion are ionized, that is, the antimicrobial performance is lost.
Therefore, it was confirmed by the following method whether the ionization of metal copper fine particles could be suppressed by using the stabilizer of the present application in combination.
The prepared paint dispersion was allowed to stand at room temperature for 3 days. Subsequently, the metallic copper fine particles contained in the paint dispersion were completely sedimented by centrifugation. Thereafter, the color of the paint dispersion was visually confirmed. If the color of the paint dispersion has not changed to light blue, it is marked as ○ (metallic copper fine particle component is maintained), and if the color has changed to light blue, it is marked as × (metallic copper fine particle component is ionized). did. Each of Examples 6 to 11 and Comparative Examples 7 to 12 was confirmed. The results are shown in Table 2, and photographs of the paint dispersions of Example 6 and Comparative Example 7 immediately after preparation and after 3 days are shown in FIG.
＜塗料分散液中の金属イオン濃度測定＞
　作製した塗料分散液を室温で３日間静置した。続いて遠心分離により、塗料分散液中に含まれる金属銅微粒子を完全に沈降させた。その後、上澄み液１ｍｌを量り取り、るつぼに加えた。次に、るつぼを（株）デンケン社製卓上マッフル炉ＫＤＦ　Ｐ９０／９０Ｇを用いて、６００℃で１時間加熱し、有機物を分解した。続いて、るつぼに蒸留水４ｍｌと硝酸１ｍｌ加え、１２０℃で１時間ホットプレートにて加熱を行った。加熱終了後、２０ｍｌメスフラスコを用いてメスアップを行い、０．４５μｍメンブレンフィルターを用いて処理液をろ過した。ろ液中に含まれる金属濃度をＴｈｅｒｍｏ　Ｆｉｓｈｅｒ　Ｓｃｉｅｎｔｉｆｉｃ（株）　ｉＣＡＰ　ＰＲＯ　ｓｅｒｉｅｓ　ＩＣＰ－ＯＥＳを用いて測定を行った。実施例６～１１、比較例７～１２を用いてそれぞれ作製した塗料分散液について測定を行い、その結果を表２に示す。 <Measurement of metal ion concentration in paint dispersion>
The prepared paint dispersion was allowed to stand at room temperature for 3 days. Subsequently, the metallic copper fine particles contained in the paint dispersion were completely sedimented by centrifugation. Thereafter, 1 ml of the supernatant liquid was weighed out and added to the crucible. Next, the crucible was heated at 600° C. for 1 hour using a tabletop muffle furnace KDF P90/90G manufactured by Denken Co., Ltd. to decompose the organic matter. Subsequently, 4 ml of distilled water and 1 ml of nitric acid were added to the crucible, and heated on a hot plate at 120° C. for 1 hour. After heating, a 20 ml volumetric flask was used to make up the volume, and the treated liquid was filtered using a 0.45 μm membrane filter. The metal concentration contained in the filtrate was measured using Thermo Fisher Scientific Co., Ltd. iCAP PRO series ICP-OES. Measurements were performed on the paint dispersions prepared using Examples 6 to 11 and Comparative Examples 7 to 12, and the results are shown in Table 2.
＜塗料分散液中における金属銅微粒子の結晶構造の測定＞
　作製した塗料分散液を室温で３日間静置した。続いて遠心分離により、塗料分散液中に含まれる金属銅微粒子を完全に沈降させた。（株）リガク社製Ｘ線回折装置　Ｓｍａｒｔ　Ｌａｂを用いて、回収した固形分中に含まれる、金属銅微粒子の結晶構造を測定した。金属銅微粒子に由来する回折ピークが確認できたものを〇（金属銅微粒子の結晶構造が維持されている）、金属銅微粒子に由来する回折ピークが確認できないものを×（金属銅微粒子の結晶構造を有しない）とした。実施例６～１１、比較例７～１２を用いてそれぞれ作製した塗料分散液について確認した。結果を表２に示す。 <Measurement of crystal structure of metallic copper fine particles in paint dispersion>
The prepared paint dispersion was allowed to stand at room temperature for 3 days. Subsequently, the metallic copper fine particles contained in the paint dispersion were completely sedimented by centrifugation. Using an X-ray diffractometer Smart Lab manufactured by Rigaku Co., Ltd., the crystal structure of the metallic copper fine particles contained in the recovered solid content was measured. Those in which a diffraction peak originating from the metallic copper microparticles can be confirmed are ○ (the crystal structure of the metallic copper microparticles is maintained), and those in which the diffraction peak originating from the metallic copper microparticles cannot be confirmed are marked as × (crystal structure of the metallic copper microparticles). ). The paint dispersions prepared using Examples 6 to 11 and Comparative Examples 7 to 12 were confirmed. The results are shown in Table 2.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
＜抗ウイルス性評価＞
　実施例１１で作製した塗料分散液を未加工の不織布に対して刷毛塗りした後、８０℃の乾燥機で５分間乾燥させた。その後、１５０℃の乾燥機で３分間乾燥させ、金属銅微粒子が固定化された不織布（成形体）を得た。 <Antiviral evaluation>
The coating dispersion prepared in Example 11 was applied to an untreated nonwoven fabric with a brush, and then dried in a dryer at 80° C. for 5 minutes. Thereafter, it was dried for 3 minutes in a dryer at 150°C to obtain a nonwoven fabric (molded body) on which metallic copper fine particles were immobilized.
（比較例１３）
　バインダー樹脂Ｂ（自己架橋型アクリル酸エステル乳化重合物）の固形分に対して金属成分濃度が０．１質量％になるように、比較例１の金属銅微粒子分散液４．０質量％と、バインダー樹脂Ｂ８．９質量％、純水８７．１質量％をそれぞれ混合して塗料分散液（比較例１３）を作製した。作製した塗料分散液を未加工の不織布に対して刷毛塗りした後、８０℃の乾燥機で５分間乾燥させた。その後、１５０℃の乾燥機で３分間乾燥させ、金属銅微粒子が固定化された不織布（成形体）を得た。 (Comparative example 13)
4.0% by mass of the metallic copper fine particle dispersion of Comparative Example 1 so that the metal component concentration was 0.1% by mass based on the solid content of binder resin B (self-crosslinking acrylic acid ester emulsion polymer), A paint dispersion liquid (Comparative Example 13) was prepared by mixing 8.9% by mass of binder resin B and 87.1% by mass of pure water. The prepared paint dispersion was applied to an unprocessed nonwoven fabric with a brush, and then dried in a dryer at 80° C. for 5 minutes. Thereafter, it was dried for 3 minutes in a dryer at 150°C to obtain a nonwoven fabric (molded body) on which metallic copper fine particles were immobilized.
＜不織布の抗ウイルス性評価方法＞
　ＪＩＳ　Ｌ　１９２２　に準じた試験方法で実施した。
　（１）宿主細胞にウイルスを感染させ、培養後、遠心分離により細胞残渣を除去したものをウイルス懸濁液とする。
　（２）上記（１）のウイルス懸濁液を滅菌蒸留水で１０倍希釈したものを試験ウイルス懸濁液とする。
　（３）不織布の試験片０．４ｇに試験ウイルス懸濁液０．２ｍｌを接種する。
　（４）２５℃２時間放置後、ＳＣＤＬＰ培地２０ｍｌを加え、ボルテックスミキサーで攪拌し、検体からウイルスを洗い出す。
　（５）プラーク測定法にてウイルス感染価を測定し、抗ウイルス活性値を算出する。
　（６）抗ウイルス活性値が３．０以上であれば、そのウイルスに対して十分な抗ウイルス性があると判断できる。 <Method for evaluating antiviral properties of nonwoven fabric>
The test was conducted in accordance with JIS L 1922.
(1) Host cells are infected with a virus, and after culturing, cell debris is removed by centrifugation to obtain a virus suspension.
(2) The virus suspension obtained in (1) above is diluted 10 times with sterile distilled water and used as a test virus suspension.
(3) Inoculate 0.2 ml of the test virus suspension onto 0.4 g of a nonwoven fabric test piece.
(4) After leaving at 25°C for 2 hours, add 20 ml of SCDLP medium and stir with a vortex mixer to wash out the virus from the sample.
(5) Measure the virus infectivity by plaque measurement and calculate the antiviral activity value.
(6) If the antiviral activity value is 3.0 or more, it can be determined that there is sufficient antiviral activity against the virus.
　バインダー樹脂Ｂを含む塗料分散液（実施例１１と比較例１３）の外観評価として、作製直後および７日間保管後の結果を表３に示す。作製直後は、実施例１１と比較例１３のいずれも色味の変化は確認されなかったが、室温下で７日間保管したものでは、実施例１１の塗料分散液は色味の変化を生じなかったが、一方、比較例１３の塗料分散液では色味の変化が確認された。 Table 3 shows the appearance evaluation of the paint dispersions containing binder resin B (Example 11 and Comparative Example 13) immediately after preparation and after storage for 7 days. Immediately after preparation, no change in color was observed in either Example 11 or Comparative Example 13, but when stored at room temperature for 7 days, the paint dispersion of Example 11 did not cause any change in color. However, on the other hand, a change in color was observed in the paint dispersion of Comparative Example 13.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
　表３に記載した作製直後、および７日間保管後の塗料分散液を用いて、それぞれ不織布に塗布し、得られた不織布の抗ウイルス性の評価を行った。その結果を表４に示す。 The paint dispersions listed in Table 3 immediately after preparation and after storage for 7 days were applied to nonwoven fabrics, and the antiviral properties of the obtained nonwoven fabrics were evaluated. The results are shown in Table 4.
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
　本発明の分散液は、繊維製品等に直接塗布或いは含浸させることにより、紙製品、マスク、ウエットティッシュ、エアコンフィルター、空気清浄機用フィルター、衣服、作業服、カーテン、カーペット、自動車用部材、包装部材、鮮度保持材、シーツ、タオル、バスマット、おむつカバー、ぬいぐるみ、スリッパ、靴インソール、ワイパーなどの掃除用品等の繊維製品に抗微生物性を有する被膜を付与することが可能になる。
　また分散液の分散媒として水系溶媒を用いることにより、水系の組成物の希釈剤として使用することや、或いは分散液中にバインダー樹脂を含有することにより、抗微生物性の塗膜を表面に有する成形品を得ることができる。
　更に、医療用具、医療用具の包装フィルム、廃棄容器、ゴミ袋、介護施設或いは病院や学校などの公共施設の壁材や床材、ワックスコート材、吐しゃ物の処理用具などに使用することができる。
　更にまた、衛生製品以外にも、フィルム、金属板、ガラス板、船舶用塗料、熱交換器フィン、或いは食器等のセラミックス製品、ゴム製品、蛇口等の金属製品、加湿器用添加剤、液体洗剤、イオン吸着剤、消臭剤など各種用途に適用可能である。 The dispersion of the present invention can be directly applied to or impregnated into textile products, etc. to produce paper products, masks, wet tissues, air conditioner filters, air purifier filters, clothing, work clothes, curtains, carpets, automobile parts, packaging, etc. It becomes possible to apply antimicrobial coatings to textile products such as parts, freshness-preserving materials, sheets, towels, bath mats, diaper covers, stuffed animals, slippers, shoe insoles, and cleaning products such as wipers.
In addition, by using an aqueous solvent as a dispersion medium of a dispersion liquid, it can be used as a diluent for an aqueous composition, or by containing a binder resin in a dispersion liquid, an antimicrobial coating film can be formed on the surface. Molded products can be obtained.
Furthermore, it can be used for medical devices, packaging films for medical devices, waste containers, garbage bags, wall and floor materials for nursing care facilities, hospitals, schools, and other public facilities, wax coating materials, vomit disposal tools, etc. can.
Furthermore, in addition to sanitary products, we also produce films, metal plates, glass plates, marine paints, heat exchanger fins, ceramic products such as tableware, rubber products, metal products such as faucets, additives for humidifiers, liquid detergents, It can be applied to various uses such as ion adsorbents and deodorants.

Claims (12)

  1. 　アスコルビン酸，アスコルビン酸の誘導体及び還元性多価フェノールの少なくとも１種から成る安定化剤、及び金属微粒子、並びに酸性官能基を有する分散剤及び／又は酸性官能基を有するバインダー樹脂を含有し、前記安定化剤が金属微粒子１００質量部に対して、１５０質量部以上の量で含有することを特徴とする分散液。 A stabilizer consisting of at least one of ascorbic acid, a derivative of ascorbic acid, and a reducing polyhydric phenol, metal fine particles, and a dispersant having an acidic functional group and/or a binder resin having an acidic functional group; A dispersion liquid characterized in that the stabilizer is contained in an amount of 150 parts by mass or more based on 100 parts by mass of metal fine particles.
  2. 　前記金属微粒子由来の金属イオン濃度が１００ｐｐｍ以下である請求項１記載の分散液。 The dispersion according to claim 1, wherein the metal ion concentration derived from the metal fine particles is 100 ppm or less.
  3. 　前記金属微粒子の含有量が０．００１～１０質量％である請求項１又は２記載の分散液。 The dispersion according to claim 1 or 2, wherein the content of the metal fine particles is 0.001 to 10% by mass.
  4. 　前記安定化剤の含有量が０．００１５～１５質量％である請求項１～３の何れかに記載の分散液。 The dispersion according to any one of claims 1 to 3, wherein the content of the stabilizer is 0.0015 to 15% by mass.
  5. 　前記金属微粒子表面が、前記安定化剤によって被覆されている請求項１～４の何れかに記載の分散液。 The dispersion liquid according to any one of claims 1 to 4, wherein the surface of the metal fine particles is coated with the stabilizer.
  6. 　前記金属微粒子が、銅又は銅化合物、或いは銀又は銀化合物から成る請求項１～５の何れかに記載の分散液。 The dispersion liquid according to any one of claims 1 to 5, wherein the metal fine particles are made of copper or a copper compound, or silver or a silver compound.
  7. 　前記分散剤及びバインダー樹脂の酸性官能基が、カルボキシル基である請求項１～６の何れかに記載の分散液。 The dispersion liquid according to any one of claims 1 to 6, wherein the acidic functional group of the dispersant and binder resin is a carboxyl group.
  8. 　前記バインダー樹脂が、アクリル樹脂，ポリエステル樹脂及びセルロース樹脂の何れかである請求項１～７の何れかに記載の分散液。 The dispersion according to any one of claims 1 to 7, wherein the binder resin is any one of an acrylic resin, a polyester resin, and a cellulose resin.
  9. 　前記金属微粒子表面が、脂肪酸及び／又は脂肪酸エステルによって更に被覆されている請求項１～８の何れかに記載の分散液。 The dispersion liquid according to any one of claims 1 to 8, wherein the surface of the metal fine particles is further coated with a fatty acid and/or a fatty acid ester.
  10. 　金属微粒子表面に、アスコルビン酸，アスコルビン酸の誘導体及び還元性多価フェノールの少なくとも１種から成る安定化剤が被覆されて成ることを特徴とする金属微粒子。 A metal fine particle characterized in that the surface of the metal fine particle is coated with a stabilizer consisting of at least one of ascorbic acid, an ascorbic acid derivative, and a reducing polyhydric phenol.
  11. 　前記金属微粒子が、銅又は銅化合物、或いは銀又は銀化合物の何れかである請求項１０記載の金属微粒子。 The metal fine particles according to claim 10, wherein the metal fine particles are either copper or a copper compound, or silver or a silver compound.
  12. 　請求項１～９の何れかに記載の分散液から成る被膜を有することを特徴とする抗微生物性成形体。 An antimicrobial molded article comprising a coating made of the dispersion according to any one of claims 1 to 9.
PCT/JP2023/012418 2022-03-31 2023-03-28 Metal microparticle-containing dispersion exhibiting antimicrobial property with excellent long-term stability WO2023190471A1 (en)

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JP2009221505A (en) * 2008-03-14 2009-10-01 Dowa Electronics Materials Co Ltd Silver nanoparticle coated with gallic acid or its derivative
JP2014008506A (en) * 2012-06-27 2014-01-20 Mitsubishi Materials Corp SnAgCu SYSTEM SOLDER POWDER AND PASTE FOR SOLDER USING THE SAME
JP2017137472A (en) * 2016-01-29 2017-08-10 東洋インキＳｃホールディングス株式会社 Conductive composition, method for producing the same, and conductive material
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