Antibacterial film, touch panel, copier

Abstract

The present invention addresses the problem of providing an antibacterial film, a touch panel, and a copier that excel in all of finger sliding performance, antidazzle performance, fingerprint visibility, and fingerprint removing performance. The antibacterial film of the present invention has a base material and at least one antibacterial layer arranged on the base material, wherein: the antibacterial layer contains a binder, light diffusing particles, and antibacterial agent particles; the ratio of a water contact angle on a surface on the side opposite to a base material side of the antibacterial layer to an oleic acid contact angle on the surface on the side opposite to the base material side of the antibacterial layer is 7.0 or more; and the relationships of Formulas (1) and (2) are satisfied.

Description

[Technical Field]

[0001] This invention relates to an antibacterial film, a touch panel, and a photocopier. [Background technology]

[0002] Touch panels such as liquid crystal displays and organic EL displays often use protective films and shatterproof films for surface protection. Touch panels used in mobile devices such as game consoles and mobile phones are frequently used, and therefore have many opportunities for bacteria to adhere to them. Furthermore, touch panel displays installed in ticket vending machines at train stations, ATMs at banks, medical equipment in medical facilities, and ordering systems in restaurants are used by a large number of people, making them highly susceptible to various bacteria in their usage environment. Therefore, a technology has been proposed to apply an antibacterial film or sheet (hereinafter, both collectively referred to as antibacterial film) to the surface of the touch panel in order to suppress bacterial growth and reduce the risk of disease transmission.

[0003] For example, Patent Document 1 describes a substrate with an antibacterial layer comprising an optically anisotropic substrate and an antibacterial layer disposed on at least a portion of the surface of the substrate, wherein the antibacterial layer contains antibacterial agent fine particles having a specific average particle size and a binder, the thickness of the antibacterial layer is greater than 5 μm and less than or equal to 15 μm, and the tensile strength of the substrate is 200 MPa or more. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2016-185686 [Overview of the project] [Problems that the invention aims to solve]

[0005] Based on the technology described in Patent Document 1 and other documents, the present inventors further investigated antibacterial films and found that such antibacterial films were inferior in at least one of the following: finger glide, glare suppression, fingerprint visibility, and fingerprint removal properties. It was difficult to obtain an antibacterial film that was superior in all of the above simultaneously.

[0006] In view of the above circumstances, the present invention aims to provide an antibacterial film that is excellent in all aspects: finger glide, glare suppression, fingerprint visibility, and fingerprint removal. Furthermore, the present invention aims to provide a touch panel and a copier. [Means for solving the problem]

[0007] As a result of diligent research into the above problems, the inventors have found that the above problems can be solved by the following configuration.

[0008] [1] Substrate and An antibacterial film having at least one antibacterial layer disposed on the above-mentioned substrate, The above antibacterial layer contains a binder, light-diffusing particles, and antibacterial agent particles. The ratio of the water contact angle on the surface of the antibacterial layer to the oleic acid contact angle on the surface opposite to the substrate side is 7.0 or greater. An antibacterial film that satisfies the relationship between equation (1) and equation (2) described later, where x μm is the arithmetic surface roughness of the surface opposite to the substrate side of the antibacterial layer, and Ps μm is the average particle size of the light-diffusing particles. [2] The antimicrobial film described in [1], wherein the haze is 10% or less. [3] The antibacterial film according to [1] or [2], wherein the above-mentioned light-diffusing particles are acrylic resin particles. [4] The antibacterial film according to any one of [1] to [3], wherein the content of the above-mentioned light-diffusing particles is 1 to 15% by mass relative to the total mass of the above-mentioned antibacterial layer. [5] The antibacterial film according to any one of [1] to [4], wherein the antibacterial agent particles contain silver. 〔6〕 The antibacterial film according to any one of [1] to [5], wherein the antibacterial agent particles contain a silver-supported carrier. 〔7〕 The antibacterial film according to any one of [1] to [6], wherein the content of the antibacterial agent particles is 0.1 to 20% by mass based on the total mass of the antibacterial layer. 〔8〕 The antibacterial film according to any one of [1] to [7], wherein the thickness of the antibacterial layer is 0.01 to 10 μm. 〔9〕 The antibacterial film according to any one of [1] to [8], wherein the material constituting the base material is at least one selected from the group consisting of polyethylene terephthalate, triacetyl cellulose, and polycarbonate. 〔10〕 The antibacterial film according to any one of [1] to [9], wherein the antibacterial layer is disposed on one surface of the base material, and an adhesive layer is disposed on the surface of the base material opposite to the surface on which the antibacterial agent is disposed. 〔11〕 A touch panel comprising the antibacterial film according to any one of [1] to

[10] . 〔12〕 A copying machine comprising the antibacterial film according to any one of [1] to

[10] .

Advantages of the Invention

[0011] Hereinafter, the present invention will be described in detail. The description of the constituent elements described below may be based on representative embodiments of the present invention, but the present invention is not limited to such embodiments.

[0012] In this specification, a numerical range represented by "~" means a range including the numerical values described before and after "~" as the lower limit value and the upper limit value. In the numerical ranges described stepwise in this specification, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the upper limit value or the lower limit value of the numerical ranges described in other stepwise descriptions. Also, in the numerical ranges described in this specification, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the value shown in the examples. In this specification, the amount of each component in the composition means the total amount of a plurality of substances present in the composition when there are a plurality of substances corresponding to each component in the composition, unless otherwise specified. In this specification, the term "step" includes not only an independent step but also cases where it cannot be clearly distinguished from other steps, as long as the intended purpose of the step is achieved. In this specification, a combination of two or more preferred embodiments is a more preferred embodiment.

[0013] [Antibacterial Film] The antibacterial film according to the present invention (hereinafter, also referred to as "this antibacterial film") is a base material, an antibacterial film having at least one antibacterial layer disposed on the base material, where the antibacterial layer contains a binder, light diffusing particles, and antibacterial agent particles, the ratio of the water contact angle to the oleic acid contact angle on the surface of the antibacterial layer opposite to the base material side of the antibacterial layer (hereinafter, also referred to as "specific contact angle ratio") is 7.0 or more, When the arithmetic surface roughness of the surface of the antibacterial layer opposite the substrate side is x μm, and the average particle size of the light-diffusing particles is Ps μm, the relationship between equation (1) and equation (2), described later, is satisfied.

[0014] The mechanism by which the above configuration provides superior finger glide, glare suppression, fingerprint visibility, and fingerprint removal is not entirely clear, but the inventors speculate as follows. The inventors hypothesize that by adjusting the components contained in the antibacterial layer (for example, the binder described later, the light-diffusing particles described later, and the surfactant described later), Ra, and the particle size of the light-diffusing particles so that the specific contact ratio is 7.0 or higher and satisfies formulas (1) and (2), excellent finger glide, glare suppression, fingerprint visibility, and fingerprint removal can be achieved. Hereinafter, if at least one of the following effects—finger glare reduction, fingerprint visibility, and fingerprint removal—is superior, it will also be referred to as "the effects of the present invention are superior." The composition of this antibacterial film is described below.

[0015] Figure 1 is a cross-sectional view showing an example of the structure of the antibacterial film. The antibacterial film 110 has a substrate 101 and an antibacterial layer 102. The antibacterial layer 102 includes a binder (not shown), light-diffusing particles, and antibacterial agent particles. In the antibacterial film 110, the surface of the substrate 101 and the antibacterial layer 102 are in direct contact.

[0016] This antibacterial film is not limited to the configuration shown in Figure 1 and may have other configurations. In the antibacterial film shown in Figure 1, the antibacterial layer 102 is arranged on one surface of the substrate 101, but the antibacterial layer may be arranged on both sides of the substrate. In the antibacterial film 110 shown in Figure 1, the antibacterial layer 102 is arranged over the entire surface of the substrate 101, but the antibacterial layer may be arranged only on a part of the substrate.

[0017] In the antibacterial film 110 shown in Figure 1, an adhesive layer may be placed on the surface of the substrate 101 opposite to the surface on which the antibacterial layer 102 is located. In this case, a separator to protect the adhesive layer may be further attached to the surface of the adhesive layer opposite to the surface on which the substrate 101 is located. Furthermore, in the antibacterial film 110 shown in Figure 1, a protective sheet may be placed on the antibacterial layer 102 to protect the antibacterial layer 102. If a protective sheet is placed, it will be removed from the antibacterial film before use. In the antibacterial film 110 shown in Figure 1, the substrate 101 and the antibacterial layer 102 are in direct contact, but a primer layer may be included between the substrate and the antibacterial layer.

[0018] [Physical properties of antibacterial films] The following details the various physical properties that make up the antibacterial film described above.

[0019] <Specific contact angle ratio> The specific contact angle ratio is the ratio of the water contact angle on the surface of the antibacterial layer opposite the substrate side to the oleic acid contact angle on the surface of the antibacterial layer opposite the substrate side (water contact angle / oleic acid contact angle). The specific contact angle ratio is 7.0 or higher, preferably 8.0 or higher, more preferably 10.0 or higher, and even more preferably 11.0 or higher. There is no particular upper limit, but it is preferably 100 or less, and more preferably 50 or less.

[0020] The water contact angle on the surface of the antibacterial layer opposite the substrate side is preferably 20 degrees or more, and more preferably 50 degrees or more. There is no particular upper limit, but it is preferably 150 degrees or less, and more preferably 100 degrees or less. In this specification, the water contact angle refers to the water contact angle measured by the following method. Using a contact angle meter (FAMMS DM-701, manufactured by Kyowa Interface Science Co., Ltd.), a 2 μL drop of pure water is dropped onto the surface of the antibacterial layer opposite the substrate side, while the layer is kept horizontal. After 20 seconds, the contact angle is measured at 10 locations, and the arithmetic mean of the measurement results is taken as the water contact angle of the antibacterial layer. The test is conducted in accordance with the static drop method of JIS R 3257:1999 under room temperature conditions of 20°C.

[0021] The oleic acid contact angle on the surface of the antibacterial layer opposite the substrate side is often 150 degrees or less, preferably 100 degrees or less, more preferably 20 degrees or less, and even more preferably 10 degrees or less. There is no particular lower limit, but it is often greater than 0 degrees. In this specification, the oleic acid contact angle refers to the contact angle measured by the same method as the measurement of the water contact angle described above, except that water is replaced with oleic acid.

[0022] Methods for adjusting the specific contact angle ratio include, for example, changing the type of surfactant (e.g., a fluorine-based surfactant) and the amount of surfactant.

[0023] <Relationship with Equation (1)> In this antibacterial film, when the arithmetic surface roughness of the surface of the antibacterial layer opposite the substrate side is x μm, the relationship in equation (1) is satisfied. 0.10 ≤ x ≤ 0.20 (1) For example, if the arithmetic surface roughness (Ra) of the surface opposite the substrate side of the antibacterial layer is 0.15 μm, then x will be 0.15. In particular, for the effects of the present invention to be superior, the antibacterial film preferably satisfies the relationship of formula (1-1), more preferably satisfies the relationship of formula (1-2), and even more preferably satisfies the relationship of formula (1-3). 0.11 ≤ x ≤ 0.18 (1-1) 0.12 ≤ x ≤ 0.16 (1-2) 0.13 ≤ x ≤ 0.15 (1-3)

[0024] In this specification, the arithmetic surface roughness refers to the arithmetic surface roughness measured by the following method. In accordance with JIS B 0601:1994, the measurement can be performed by analyzing the shape of a 10 μm square area on the surface opposite to the substrate side of the antibacterial layer using a laser microscope (for example, KEYENCE's "VK-9500").

[0025] Methods for adjusting the above-mentioned arithmetic surface roughness include, for example, adjusting the average particle size of light-diffusing particles, the thickness of the antibacterial layer, the type and content of the binder, the application conditions of the antibacterial layer-forming composition in the antibacterial film manufacturing method (application method and application amount, etc.), and the heating conditions of the coated layer in the antibacterial film manufacturing method to the preferred embodiments described later.

[0026] <Relationship in Equation (2)> In this antibacterial film, when the arithmetic surface roughness of the surface of the antibacterial layer opposite the substrate side is x μm and the average particle size of the light-diffusing particles is Ps μm, the relationship in equation (2) is satisfied. 7.7x+1.0 ≦ Ps ≦ 7.7x+3.0 (2) In equation (2), x is as described above. For example, if the average particle size of the light-diffusing particles is 2.0 μm, then the above Ps will be 2.0. In particular, for the effects of the present invention to be superior, it is preferable that the antibacterial film satisfies the relationship of formula (2-1), and more preferably that it satisfies the relationship of formula (2-2). 7.7x+1.2 ≦ Ps ≦ 7.7x+2.8 (2-1) 7.7x+1.5 ≦ Ps ≦ 7.7x+2.5 (2-2)

[0027] In this specification, Ps refers to the average particle size measured by the following method. The 50% volume cumulative diameter (D50) was measured three times using a laser diffraction scattering particle size distribution analyzer manufactured by Horiba, Ltd., and the arithmetic mean of the obtained measurements was used. Furthermore, the above Ps was obtained by observing the light-diffusing particles with a scanning electron microscope (SEM) and measuring the diameter (particle size) of each particle. Alternatively, the particle size of 100 particles could be measured and their average value used as the average particle size.

[0028] <Hayes> The haze of the antibacterial film in the wavelength range of 380 to 750 nm is not particularly limited, but is preferably 10% or less, and more preferably 8% or less. The lower limit is not particularly limited, but is preferably 0% or more. The above haze can be measured in accordance with JIS K 7136(2000) using commercially available measuring devices such as the NDH5000 manufactured by Nippon Denshoku Industries Co., Ltd. One method for adjusting the haze mentioned above is to adjust the content of light-diffusing particles. The following provides a detailed description of each component that makes up the antibacterial film mentioned above.

[0029] [Base material] This antibacterial film has a base material. There are no particular restrictions on the substrate material; any known substrate material can be used. A transparent substrate is preferred as the base material. Here, a transparent substrate is defined as having a transmittance of 80% or more for light rays with wavelengths ranging from 380 to 780 nm. From the viewpoint of improving the mechanical strength of the base material, a stretched base material is preferred, and a biaxially stretched base material is more preferred. The stretching ratio is not particularly limited, but is preferably in the range of 1.5 times to 7 times. If the stretching ratio is less than 1.5 times, the mechanical strength may be insufficient, and if the stretching ratio exceeds 7 times, the thickness may lack uniformity. The stretching ratio is more preferably in the range of 2 times to 5 times. Particularly preferred stretching directions and ratios are in the range of 2 times to 5 times in two mutually orthogonal directions. The optical properties of the substrate are preferably such that the haze is 0.5 to 1.5% and the total light transmittance is 90% or more. The method for measuring the haze described above is as stated above.

[0030] Examples of materials that make up the base material include polyethylene terephthalate (PET), triacetylcellulose (TAC), polycarbonate (PC), polybutylene terephthalate (PBT), and polyimide. Among these, polyethylene terephthalate (PET), triacetylcellulose (TAC), or polycarbonate (PC) are preferred due to their ease of handling and excellent transparency. Examples of PET base materials include "Lumirror® U34" manufactured by Toray Industries, Inc., "Cosmoshine® A4300" manufactured by Toyobo Co., Ltd., and "O3916W" manufactured by Teijin Limited.

[0031] The shape of the substrate is not particularly limited, but examples include film and sheet forms. Furthermore, the surface of the substrate on which the antibacterial layer described later is placed may be flat or curved. A conventionally known easy-adhesion layer (primer layer) may be formed on the surface of the substrate on which the antibacterial layer is placed. The thickness of the substrate is not particularly limited, but is preferably 10 to 300 μm, and more preferably 50 to 150 μm. The thickness of the substrate is determined by measuring the thickness of 10 arbitrary points on the substrate with a micrometer and taking the arithmetic mean of the measurement results.

[0032] [Antibacterial layer] The antibacterial layer contains a binder, light-diffusing particles, and antibacterial agent particles.

[0033] <Antibacterial particles> There are no particular restrictions on the antimicrobial agent particles; known particulate antimicrobial agents can be used. Furthermore, as antibacterial agent particles, those that exhibit bactericidal effects against pathogenic bacteria such as Staphylococcus aureus and Escherichia coli are preferably used.

[0034] The shape of the antimicrobial agent particles is not particularly limited and may be spherical, ellipsoidal, rod-shaped, plate-shaped, needle-shaped, or irregularly shaped, for example.

[0035] The antimicrobial agent particles preferably contain metal. This is because metal ions are generated from the metal contained in the antimicrobial agent particles, and these metal ions act on microorganisms (hereinafter also referred to as "bacteria"), thereby exhibiting antimicrobial activity. Furthermore, in addition to its antibacterial effect against pathogenic bacteria, it is also preferable because it possesses antibacterial properties against fungi such as molds and antiviral properties against viruses. Examples of the above-mentioned viruses include influenza virus, SARS coronavirus (SARS-CoV), and novel coronavirus (SARS-CoV-2). For evaluating antiviral activity, known methods can be used, for example. Specifically, it is preferable to change the test virus to viruses such as influenza virus, SARS coronavirus, and novel coronavirus, and evaluate it using a method compliant with ISO 21702. Furthermore, the antiviral activity value is preferably greater than 1.0, more preferably 2.0 or higher, and even more preferably greater than 2.0.

[0036] Examples of the above-mentioned metals include silver, mercury, zinc, iron, lead, bismuth, titanium, tin, and nickel. Furthermore, the form of the metal contained in the antibacterial agent particles is not particularly limited and may take the form of metal particles, metal ions, and metal salts (including metal complexes). In particular, copper, zinc, or silver are preferred as the metal because the antibacterial layer has superior antibacterial properties, and silver is more preferred because it is highly safe and has a broad antibacterial spectrum. Furthermore, metal salts are preferred as the metal.

[0037] As for the antibacterial agent particles, antibacterial agent particles containing silver (hereinafter also referred to as "silver-based antibacterial agents") are preferred because the antibacterial layer has superior antibacterial properties. In other words, it is preferable that the above metal is silver. As a silver-based antimicrobial agent, it is sufficient that it contains silver (silver atoms), and the type is not particularly limited. Furthermore, the form of silver is not particularly limited; for example, it may be included in the form of metallic silver, silver ions, or silver salts (including silver complexes). For example, silver-based antimicrobial agents include silver particles that release silver ions slowly, or inorganic antimicrobial agents containing silver (e.g., silver and / or silver ions supported on a carrier). In this specification, silver complexes are included within the range of silver salts.

[0038] Examples of silver salts include silver acetate, silver acetylacetate, silver azide, silver acetylide, silver arsenate, silver benzoate, silver hydrogen fluoride, silver bromate, silver bromide, silver carbonate, silver chloride, silver chlorate, silver chromate, silver citrate, silver cyanate, silver cyanide, (cis,cis-1,5-cyclooctadiene)-1,1,1,5,5,5-hexafluoroacetylacetate silver, diethyldithiocarbamate silver, silver(I) fluoride, silver(II) fluoride, 7,7-dimethyl-1,1,1,2,2,3,3-heptafluoro-4,6-octanedionate silver, silver hexafluoroantimone, silver hexafluoroarsenate, silver hexafluorophosphate, silver iodate, and silver iodide. Examples include silver isothiocyanate, potassium silver cyanide, silver lactate, silver molybdate, silver nitrate, silver nitrite, silver(I) oxide, silver(II) oxide, silver oxalate, silver perchlorate, silver perfluorobutyrate, silver perfluoropropionate, silver permanganate, silver perrhenate, silver phosphate, silver picrate monohydrate, silver propionate, silver selenate, silver selenide, silver selenite, silver sulfadiazine, silver sulfate, silver sulfide, silver sulfite, silver telluride, silver tetrafluoroborate, silver tetraiodomucurate, silver tetratungstate, silver thiocyanate, silver p-toluenesulfonate, silver trifluoromethanesulfonate, silver trifluoroacetate, and silver vanadate. Examples of silver complexes include histidine silver complex, methionine silver complex, cysteine ​​silver complex, aspartate silver complex, pyrrolidone carboxylate silver complex, oxotetrahydrofuranate silver complex, and imidazole silver complex. As a silver-based antibacterial agent, a silver-supported carrier containing a carrier and silver supported on the carrier is preferred because it exhibits superior antibacterial properties.

[0039] The antimicrobial particles are preferably a carrier and a metal-supported carrier containing the above-mentioned metal supported on the carrier, with a silver-supported carrier being more preferred. The type of carrier is not particularly limited, and known carriers can be used. Examples of carriers include, but are not limited to, zeolite-based carriers, calcium silicate-based carriers, zirconium phosphate-based carriers, calcium phosphate-based carriers, zinc oxide-based carriers, soluble glass-based carriers, silica gel-based carriers, activated carbon-based carriers, titanium dioxide-based carriers, titania-based carriers, organometallic-based carriers, ion-exchange ceramic-based carriers, layered phosphate-quaternary ammonium salt-based carriers, and antibacterial stainless steel carriers.

[0040] More specifically, the materials that constitute the support include zinc calcium phosphate, calcium phosphate, zirconium phosphate, aluminum phosphate, calcium silicate, activated carbon, activated alumina, silica gel, zeolite, hydroxyapatite, zirconium phosphate, titanium phosphate, potassium titanate, hydrated bismuth oxide, hydrated zirconium oxide, and hydrotalcite. Examples of zeolites include natural zeolites such as chabasite, mordenite, erionite, and clinoptilolite, as well as synthetic zeolites such as type A zeolite, type X zeolite, and type Y zeolite. Furthermore, so-called ceramics are preferred as the carrier. Specifically, metal-supported ceramic particles are preferred as the antibacterial agent particles, and silver-supported ceramic particles are more preferred.

[0041] When the antimicrobial agent particles contain metal, the metal content is not particularly limited, but it is preferably 0.1 to 30% by mass, and more preferably 0.5 to 20% by mass, relative to the total mass of the antimicrobial agent particles (metal-supported carrier).

[0042] Examples of commercially available silver-based antibacterial agents include silver zeolite-based antibacterial agents such as "Zeomic" from Sinanen Zeomic Co., Ltd., "Silwell" from Fuji Silysia Chemical Co., Ltd., and "Bactenon" from Nippon Denshi Materials Co., Ltd.; silver-based antibacterial agents in which silver is supported on inorganic ion exchange ceramics, such as "Novaron" from Toagosei Co., Ltd. and "Atomy Ball" from Shokubai Kasei Kogyo Co., Ltd.; silver particles such as "Nano Silver" from Nippon Ion Co., Ltd.; and silver-supported ceramic particles (silver ceramic particles) in which silver is chemically bonded to ceramics, such as "Bactekiller" and "Bacterite" from Fuji Chemical Co., Ltd.

[0043] The average particle size of the antimicrobial agent is preferably 0.1 to 10 μm, and more preferably 0.3 to 3 μm, in terms of achieving a good balance between ease of handling and transparency of the antimicrobial layer. The average particle size of the antibacterial agent is determined by measuring the 50% volume cumulative diameter (D50) three times using a laser diffraction scattering particle size distribution analyzer manufactured by Horiba, Ltd., and using the arithmetic mean of the obtained measurements. Furthermore, the average particle size of the antibacterial agent particles was determined by observing the particles with a scanning electron microscope (SEM) or transmission electron microscope (TEM) and measuring the diameter (particle size) of each particle. Alternatively, the particle size of 100 particles could be measured and their average value used as the average particle size.

[0044] Antimicrobial agent particles may be used individually or in combination of two or more types. The content of antibacterial agent particles in the antibacterial layer is not particularly limited, but is preferably 0.1 to 20% by mass, more preferably 0.2 to 10% by mass, and even more preferably 1.0 to 7% by mass, relative to the total mass of the antibacterial layer.

[0045] If the antibacterial agent particles contain metal, the amount of antibacterial agent particles applied should be 3.0 mg / m² per unit area of ​​the antibacterial film, in terms of metal content, from the perspective of imparting antiviral properties. 2 Preferably, it is 5.0 mg / m² or more. 2 It is more preferable that the above conditions are met.

[0046] Furthermore, other antibacterial agents besides antibacterial particles may be used in combination with antibacterial particles. Other antimicrobial agents include, for example, organic antimicrobial agents such as phenol ether derivatives, imidazole derivatives, sulfone derivatives, N-haloalkylthio compounds, anilide derivatives, pyrrole derivatives, quaternary ammonium salts, pyridine compounds, triazine compounds, benzoisothiazoline compounds, and isothiazoline compounds. Furthermore, organic antibacterial agents also include natural antibacterial agents. An example of a natural antibacterial agent is chitosan, a basic polysaccharide obtained by hydrolyzing chitin contained in the shells of crabs or shrimp.

[0047] <Binder> The antibacterial layer contains a binder. The binder is not particularly limited, and known binders can be used. Examples of binders include polyester resins, acrylic resins, methacrylic resins, resins made of methacrylic acid-maleic acid copolymers, polystyrene resins, fluororesins, polyimide resins, fluorinated polyimide resins, polyamide resins, polyamideimide resins, polyetherimide resins, cellulose acylate resins, polyurethane resins, polyetheretherketone resins, polycarbonate resins, alicyclic polyolefin resins, polyarylate resins, polyethersulfone resins, polysulfone resins, resins made of cycloolefin copolymers, fluorene ring-modified polycarbonate resins, alicyclic-modified polycarbonate resins, and fluorene ring-modified polyester resins.

[0048] A polymer having hydrophilic groups (hereinafter also referred to as "hydrophilic polymer") is preferred as the binder contained in the antibacterial layer. By containing a hydrophilic polymer in the antibacterial layer, the antibacterial layer exhibits greater hydrophilicity, resulting in superior antibacterial properties, and contaminants adhering to the surface of the antibacterial layer can be removed more easily by washing with a cleaning solution such as water.

[0049] The type of hydrophilic group is not particularly limited and includes, for example, polyoxyalkylene groups (e.g., polyoxyethylene groups, polyoxypropylene groups, and polyoxyalkylene groups in which oxyethylene groups and oxypropylene groups are block-bonded or randomly bonded), amino groups, carboxyl groups, alkali metal salts of carboxyl groups, hydroxyl groups, alkoxy groups, amide groups, carbamoyl groups, sulfonamide groups, sulfamoyl groups, sulfonic acid groups, and alkali metal salts of sulfonic acid groups. Among these, polyoxyalkylene groups are preferred. The structure of the main chain of the hydrophilic polymer is not particularly limited and includes, for example, polyurethane, poly(meth)acrylate, polystyrene, polyester, polyamide, polyimide, and polyurea. Note that the term "poly(meth)acrylate" is a concept that includes both polyacrylate and polymethacrylate.

[0050] As the hydrophilic polymer, a polymer obtained by polymerizing a monomer having the above-mentioned hydrophilic group (hereinafter also referred to as "hydrophilic monomer") is preferred. A hydrophilic monomer means a compound (monomer and / or oligomer) having the above-mentioned hydrophilic group and polymerizable group. The number of hydrophilic groups in the hydrophilic monomer is not particularly limited, but it is preferable to have one or more, more preferably 1 to 6, and even more preferably 1 to 3, in order to make the antibacterial layer more hydrophilic.

[0051] The type of polymerizable group in the hydrophilic monomer is not particularly limited, and examples include radical polymerizable groups, cationic polymerizable groups, and anionic polymerizable groups. Examples of radical polymerizable groups include (meth)acryloyl groups, acrylamide groups, vinyl groups, styryl groups, and allyl groups. Examples of cationic polymerizable groups include vinyl ether groups, oxyranyl groups, and oxetanyl groups. Among these, (meth)acryloyl groups are preferred. Note that the (meth)acryloyl group is a concept that includes both acryloyl groups and methacryloyl groups. The number of polymerizable groups in the hydrophilic monomer is not particularly limited, but two or more are preferred, two to six are more preferred, and two to three are even more preferred, in terms of superior mechanical strength of the resulting antibacterial layer.

[0052] One preferred embodiment of the hydrophilic monomer is a compound represented by the following formula (A).

[0053] [ka]

[0054] In formula (A), R1 represents a hydrogen atom or a substituent (a monovalent substituent). The type of substituent is not particularly limited and includes known substituents, such as hydrocarbon groups which may have heteroatoms (e.g., alkyl and aryl groups, etc.) and the hydrophilic group mentioned above. R2 represents a polymerizable group. The definition of a polymerizable group is as described above. L1 represents a single bond or a divalent linking group. The type of divalent linking group is not particularly limited and includes, for example, -O-, -CO-, -NH-, -CO-NH-, -COO-, -O-COO-, alkylene groups, arylene groups, heteroaryl groups, and combinations thereof. L2 represents a polyoxyalkylene group. A polyoxyalkylene group is a group represented by the following formula (B). Formula (B) *-(OR3) m -* In formula (B), R3 represents an alkylene group (e.g., an ethylene group, a propylene group). m represents an integer of 2 or more, preferably an integer between 2 and 10, and more preferably an integer between 2 and 6. * represents the bond position. n represents an integer between 1 and 4.

[0055] As the hydrophilic monomer having the hydrophilic group and polymerizable group described above, commercially available products can be used. Examples of such commercially available products include "NK Ester A-GLY-9E" manufactured by Shin Nakamura Chemical Industry Co., Ltd., "Miramer M4004" manufactured by Toyo Chemicals Co., Ltd., and "Miramer M3150" manufactured by Toyo Chemicals Co., Ltd.

[0056] When producing hydrophilic polymers, it is preferable to use polyfunctional monomers that do not have hydrophilic groups but have two or more polymerizable groups, as this results in superior mechanical strength of the antibacterial layer. This is because polyfunctional monomers act as so-called crosslinking agents, creating a three-dimensional network structure that facilitates the movement of metal ions such as silver ions, and thus enabling the production of hydrophilic polymers that exhibit superior antibacterial properties. For the reasons mentioned above, it is preferable to use two or more types of polyfunctional monomers. Polyfunctional monomers may or may not have hydrophilic groups. The number of polymerizable groups contained in the polyfunctional monomer is not particularly limited, but 2 to 10 groups are preferred, and 2 to 6 groups are more preferred, from the viewpoint of superior mechanical strength of the antibacterial layer and ease of handling. Examples of polyfunctional monomers include trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, dipentaerythritol hexaacrylate, pentaerythritol triacrylate, and pentaerythritol tetraacrylate. Commercially available polyfunctional monomers (crosslinking agents) can be used. Examples of such commercially available products include "DPHA-76" (dipentaerythritol hexaacrylate) manufactured by Toshin Oils Co., Ltd., "KAYARAD PET-30" (a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate) manufactured by Nippon Kayaku Co., Ltd., and "A-DPH" (dipentaerythritol hexaacrylate) manufactured by Shin Nakamura Chemical Industry Co., Ltd.

[0057] As the hydrophilic polymer, a copolymer consisting of the compound represented by formula (A) and a polyfunctional monomer is preferred. The mixing ratio of the compound represented by formula (A) and the polyfunctional monomer is not particularly limited, but the ratio of the content of the compound represented by formula (A) to the content of the polyfunctional monomer is preferably 0.01 to 10 by mass ratio, and more preferably 0.03 to 1.

[0058] You may use one type of binder alone, or two or more types in combination. The binder content in the antibacterial layer is not particularly limited, but is preferably 3 to 98% by mass, more preferably 5 to 95% by mass, and even more preferably 10 to 93% by mass, relative to the total mass of the antibacterial layer.

[0059] <Light-diffusing particles> The antibacterial layer contains light-diffusing particles. The light-diffusing particles are not particularly limited as long as they function as so-called matting agents, and may be organic particles, inorganic particles, or organic-inorganic composite particles. Examples of organic particles include resin particles. More specifically, these include silicone resin particles, acrylic resin particles such as polymethyl methacrylate (PMMA), nylon resin particles, styrene resin particles, polyethylene particles, urethane resin particles, and benzoguanamine particles. The organic particles may also have a hollow structure. Inorganic particles such as diamond, titanium oxide, zirconium oxide, lead oxide, lead carbonate, zinc oxide, zinc sulfide, antimony oxide, silicon oxide, and aluminum oxide can be used. Titanium oxide or aluminum oxide are preferred due to the ease of obtaining particles with suitable refractive indices. As light-diffusing particles, silicone resin particles or acrylic resin particles are preferred, and acrylic resin particles are more preferred, due to their superior anti-glare function through light scattering.

[0060] Light-diffusing particles may be used individually or in combination of two or more types. The content of light-diffusing particles is not particularly limited, but is preferably 1 to 15% by mass, more preferably 2 to 12% by mass, and even more preferably 3 to 8% by mass, relative to the total mass of the antibacterial layer.

[0061] <Optional ingredients> The antibacterial layer may contain any other components as long as it achieves the effects of the present invention. Optional components include, for example, dispersants, surfactants, photocatalytic materials, and hydrophilicity-imparting agents.

[0062] (Dispersant) The antibacterial layer may contain a dispersant. Dispersants are compounds that have the function of improving the dispersibility of antimicrobial agent particles. The dispersant is not particularly limited, and known dispersants can be used, but dispersants having an acidic group are preferred. Examples of acidic groups include carboxyl groups, sulfonic acid groups, and phosphate groups. Examples of commercially available dispersants include DISPERBYK-102, DISPERBYK-106, DISPERBYK-108, DISPERBYK-110, DISPERBYK-111, DISPERBYK-140, DISPERBYK-142, DISPERBYK-9076, DISPERBYK-118, and DISPERBYK-180 (all manufactured by Bic Chemie); Solsperse26000, Solsperse36000, and Solsperse41000 (all manufactured by Lubrizol); and Adisper PB821, Adisper PB822, Adisper PB824, and Adisper PB881 (all manufactured by Ajinomoto Fine Techno Co., Ltd.).

[0063] Dispersing agents may be used individually or in combination of two or more. If the antibacterial layer contains a dispersant, the dispersant content is preferably 10 to 500% by mass relative to the total mass of the antibacterial particles.

[0064] (Surfactants) The antibacterial layer may contain a surfactant. The surfactant allows the water contact angle and oleic acid contact angle of the surface of the antibacterial layer to be adjusted to a desired range. Furthermore, when forming the antibacterial layer by coating using the antibacterial layer forming composition described below, it is easier to form a coating film with a more uniform thickness and / or a smoother surface. The surfactant is not particularly limited, and known surfactants can be used. Examples of surfactants include nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants, with nonionic surfactants being preferred and fluorinated surfactants being more preferred.

[0065] Examples of nonionic surfactants include ester types such as glycerin fatty acid esters, sorbitan fatty acid esters, and sucrose fatty acid esters; ether types such as polyoxyethylene alkyl ethers and polyoxyethylene polyoxypropylene glycols; ester ether types such as fatty acid polyethylene glycols and fatty acid polyoxyethylene sorbitan; and alkanolamide types such as fatty acid alkanolamides. More specific examples of nonionic surfactants include polyethylene glycol mono(meth)acrylate, polyethylene glycol monolauryl ether, polyethylene glycol monostearyl ether, polyethylene glycol monocetyl ether, polyethylene glycol monolauryl ester, and polyethylene glycol monostearyl ester.

[0066] Examples of ionic surfactants include anionic surfactants such as alkyl sulfates, alkylbenzene sulfonates, and alkyl phosphates; cationic surfactants such as alkyltrimethylammonium salts and dialkyldimethylammonium salts; and amphoteric surfactants such as alkylcarboxybetaine.

[0067] Furthermore, examples of surfactants include fluorine-based surfactants. Examples of fluorine-based surfactants include the compounds described in paragraphs

[0082] to

[0090] of Japanese Patent Publication No. 2014-119605. Fluorine-based surfactants may also preferably contain polymerizable groups. Examples of surfactants containing polymerizable groups include X-71-1203E (manufactured by Shin-Etsu Chemical Co., Ltd.), the Futergent series (manufactured by Neos Corporation), Fluorosurf® FS-7072 (manufactured by Fluorotechnology Corporation), and Megafac® F-780-F, RS-101, RS-102, RS-718K, and RS-72-K (all manufactured by DIC Corporation).

[0068] As for fluorine-based surfactants, from the viewpoint of improving environmental suitability, it is preferable that the surfactant is derived from a substitute material for compounds having a linear perfluoroalkyl group with 7 or more carbon atoms, such as perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS).

[0069] Surfactants may be used individually or in combination of two or more types. If the antibacterial layer contains a surfactant, the surfactant content is preferably 0.1 to 10% by mass relative to the total mass of the antibacterial layer.

[0070] (Photocatalytic material) The antibacterial layer may contain a photocatalytic material that includes a metal oxide. The type of metal oxide contained in the photocatalytic material is not particularly limited, but examples include TiO2, ZnO, SrTiO3, CdS, GaP, InP, GaAs, BaTiO3, BaTiO4, BaTi4O9, K2NbO3, Nb2O5, Fe2O3, Ta2O5, K3Ta3Si2O3, WO3, SnO2, Bi2O3, BiVO4, NiO, Cu2O, SiC, MoS2, InPb, RuO2, CeO2, and Ta3N5, as well as layered oxides having at least one element selected from the group consisting of Ti, Nb, Ta, and V. Among these, metal oxides containing at least one metal atom selected from the group consisting of Zn, Ti, Ni, W, Cu, Sn, Fe, Sr, and Bi are preferred. The average particle size of photocatalytic materials (excluding those used as antibacterial agent particles) is not particularly limited, but is preferably between 1 nm and 2 μm. The average particle size of photocatalytic materials can be measured using the same method as for measuring the average particle size of antibacterial agent particles. When the antibacterial layer contains a photocatalytic material, the mass ratio of the antibacterial agent particles to the mass of the photocatalytic material (mass of antibacterial agent particles / mass of photocatalytic material) is preferably 0.01 to 20, more preferably 0.1 to 10, and even more preferably 0.3 to 3.

[0071] (Hydrophilicity imparting agent) The antibacterial layer may contain a hydrophilic agent. The hydrophilic agent is a compound that has the function of reducing the water contact angle on the surface of the antibacterial layer, and is intended to be a compound that is not included in the surfactants mentioned above. The hydrophilic agent is not particularly limited as long as it is a compound that has the function of reducing the water contact angle on the surface of the antibacterial layer, and examples include ethyl (meth)acrylate, n-butyl (meth)acrylate, and isobutyl (meth)acrylate. Hydrophilicity-imparting agents may be used individually or in combination of two or more types. If the antibacterial layer contains a hydrophilic agent, the hydrophilic agent content is preferably 0.1 to 30% by mass relative to the total mass of the antibacterial layer.

[0072] Other optional components that the antibacterial layer may contain include, for example, polymerization initiators, ultraviolet absorbers, fillers, antioxidants, anti-aging agents, antistatic agents, flame retardants, adhesion promoters, antioxidants, defoamers, leveling agents, matting agents, light stabilizers, deodorants, dyes, fragrances, and pigments, as described later.

[0073] <Physical properties of the antibacterial layer> (thickness) The thickness of the antibacterial layer is not particularly limited, but it is preferably 0.01 to 10 μm, more preferably 0.01 to 8 μm, and even more preferably 0.01 to 6 μm, as it provides a good balance of durability and transparency. The thickness of the antibacterial layer is measured by embedding a sample piece containing the antibacterial layer in resin, carving a cross-section with a microtome, and observing the carved cross-section with a scanning electron microscope. The thickness of the antibacterial layer is determined by measuring the thickness of the antibacterial layer at 10 arbitrary points in the antibacterial layer using the method described above, and taking the arithmetic mean of the measured values.

[0074] <Other layers> The antibacterial film may have layers other than the substrate and antibacterial layer described above. Other layers besides the substrate and antibacterial layer include an adhesive layer, a release film, the protective sheet mentioned above, and the easy-adhesion layer (primer layer) mentioned above.

[0075] The antibacterial film may have an adhesive layer. The adhesive layer is for attaching the antibacterial film to the antibacterial layer-forming surface of various devices. The adhesive layer can be any type that can attach the antibacterial film to various antibacterial layer-forming surfaces, and may be formed using a known adhesive. Examples of adhesives that can be used in the adhesive layer include (meth)acrylic adhesives, rubber adhesives, silicone adhesives, urethane adhesives, and polyester adhesives. (Meth)acrylic adhesives refer to acrylic adhesives and / or methacrylic adhesives. When an antibacterial film has an adhesive layer, it is preferable that the antibacterial layer is placed on one surface of the substrate, and the adhesive layer is placed on the surface of the substrate opposite to the surface where the antibacterial agent is placed. This ensures that when the antibacterial film is attached to the antibacterial layer-forming surface of the device, the antibacterial layer is positioned closer to the exposed surface.

[0076] The thickness of the adhesive layer is not particularly limited, but is preferably 1 to 30 μm, and more preferably 2 to 20 μm. The adhesive strength of the adhesive layer is not particularly limited, but 2 to 20 cN / 25 mm is preferred. If the adhesive strength is 2 cN / 25 mm or higher, peeling is less likely to occur when it is attached to a surface such as a touch panel. On the other hand, if the adhesive strength is 20 cN / 25 mm or lower, the antibacterial film can be peeled off smoothly.

[0077] If the antibacterial film has an adhesive layer, it is preferable that the antibacterial film further has a release film. The release film is adhered to the adhesive layer to protect it until the antibacterial film is used. Any release film that can protect the adhesive layer can be used, and known release films can be used. Examples of release films include silicone compounds, long-chain alkyl compounds, and polyvinyl alcohol carbamates. The thickness of the release film is not particularly limited, but is preferably 1 to 30 μm, and more preferably 2 to 20 μm.

[0078] [Method for manufacturing antibacterial film] The method for manufacturing an antibacterial film is not particularly limited as long as it can produce an antibacterial film having a substrate and an antibacterial layer disposed on the substrate. Examples of methods for manufacturing an antibacterial film include forming an antibacterial layer on a substrate, forming a substrate on an antibacterial layer, laminating a pre-formed antibacterial layer and a pre-formed substrate together, and bonding the antibacterial layer and the substrate while forming them by co-extrusion or the like. In particular, a method (coating method) for forming an antibacterial film is preferred, which involves applying an antibacterial layer-forming composition to a predetermined position on a substrate to form a coating film, and then drying and / or curing the coating film. More preferably, the method comprises the steps of: applying an antibacterial layer-forming composition to a predetermined position on a substrate to form a coating film; heating and drying the coating film; and curing the coating film by irradiating it with ultraviolet light to form an antibacterial layer.

[0079] The antimicrobial layer-forming composition contains at least antimicrobial particles, a binder, and light-diffusing particles. If the binder is a polymer obtained by polymerizing monomers, the antimicrobial layer-forming composition may contain at least antimicrobial particles, monomers (e.g., hydrophilic monomers and polyfunctional monomers), and light-diffusing particles. The antibacterial layer-forming composition will be described later.

[0080] The method for applying the antibacterial layer-forming composition to the surface of the substrate is not particularly limited, and known application methods can be applied. Examples of methods for applying the antibacterial layer-forming composition to the surface of the substrate include spraying, wire bar coating, extrusion coating, direct gravure coating, reverse gravure coating, inkjet, die coating, electrostatic coating, and wiping.

[0081] An antibacterial layer is formed by drying and / or curing the coating film formed on the surface of the substrate by the above coating method. A method for removing the solvent from the coated film of the antibacterial layer-forming composition and drying it is, for example, heat treatment. The conditions for the heat treatment are not particularly limited, but for example, the heating temperature is preferably 20 to 150°C, and more preferably 20 to 60°C. The heating time is preferably 15 to 600 seconds.

[0082] The antibacterial layer may be formed by curing the coated film of the antibacterial layer-forming composition containing monomers through exposure treatment. The exposure treatment is not particularly limited, but 190 mJ / cm² is recommended. 2 It is preferable to cure the coated film by irradiating it with ultraviolet light at the above dose. There is no particular upper limit to the irradiation dose, but 600 mJ / cm² is preferable. 2 The following are preferable. For ultraviolet irradiation, ultraviolet light emitted from sources such as ultra-high pressure mercury lamps, high-pressure mercury lamps, low-pressure mercury lamps, carbon arc lamps, xenon arc lamps, and metal halide lamps can be used.

[0083] <Composition for forming antibacterial layer> The antimicrobial layer-forming composition comprises at least antimicrobial agent particles, a binder or monomer, and light-diffusing particles. The antibacterial layer-forming composition may contain any of the above-mentioned optional components included in the antibacterial layer. The antibacterial layer-forming composition preferably contains a solvent. Furthermore, if the antibacterial layer-forming composition contains a monomer, it is preferable that it further contains a polymerization initiator. When the antibacterial layer-forming composition contains a polymerization initiator, the antibacterial layer containing the polymer has superior mechanical strength. The components other than the solvent and polymerization initiator have already been described, including their preferred embodiments.

[0084] (solvent) The solvent included in the antibacterial layer-forming composition is not particularly limited and includes water and organic solvents. In particular, it is preferable that the solvent contains an organic solvent, as this makes it easier to achieve a more uniform thickness of the coated film. Examples of organic solvents include methanol, ethanol, acetone, methyl ethyl ketone, cyclohexane, ethyl acetate, ethylene dichloride, tetrahydrofuran, toluene, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, acetylacetone, cyclohexanone, diacetone alcohol, ethylene glycol monomethyl ether acetate, ethylene glycol ethyl ether acetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether acetate, 3-methoxypropanol, methoxymethoxyethanol, diethylene glycol monomethyl ether Examples include ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether acetate, n-propanol, isopropanol, n-butanol, 2-butanol, i-butanol, t-butanol, n-pentanol, t-amyl alcohol, n-hexanol, caprylic alcohol, lauryl alcohol, myristyl alcohol, phenylethyl alcohol, ethylene glycol, ethylene glycol mono-n-butyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol mono-n-butyl ether, tetraethylene glycol mono-n-butyl ether, and dipropylene glycol monobutyl ether.

[0085] The solvent may be used alone or in combination of two or more types. The solid content in the antibacterial layer-forming composition, i.e., the total content of components other than the solvent, is not particularly limited, but it is preferably 1 to 50% by mass of the total mass of the antibacterial layer-forming composition, as this facilitates the formation of a coating film with more uniform thickness.

[0086] (Polymerization initiator) The polymerization initiator is not particularly limited, and known polymerization initiators can be used. Examples of polymerization initiators include thermal polymerization initiators and photopolymerization initiators, with photopolymerization initiators being preferred due to their superior reaction efficiency. Examples of polymerization initiators include aromatic ketones such as benzophenone and phenylphosphine oxide; α-hydroxyalkylphenone compounds (BASF products such as IRGACURE 184, 127, 2959, and DAROCUR 1173); and phenylphosphine oxide compounds (monoacylphosphine oxide: BASF product IRGACURE TPO and bisacylphosphine oxide: BASF product IRGACURE 819).

[0087] Polymerization initiators may be used individually or in combination of two or more. When the antibacterial layer-forming composition contains a polymerization initiator, the content of the polymerization initiator is not particularly limited, but it is preferably 0.1 to 15% by mass, and more preferably 1 to 6% by mass, relative to the monomer content.

[0088] The antibacterial layer-forming composition can be prepared by mixing the above components. The order in which the above components are mixed is not particularly limited, however, if the antibacterial layer-forming composition contains a dispersant, the antibacterial agent particles and the dispersant may be mixed first to prepare a dispersion in which the antibacterial agent particles are dispersed.

[0089] [Uses of antibacterial film] This antibacterial film can be applied to a variety of uses. For example, by placing the antibacterial film on the surface of various items, antibacterial properties can be imparted to the surface of those items. Furthermore, by placing this antibacterial film on the transparent substrate surface of devices such as displays, it can be used as an anti-glare antibacterial film with excellent image visibility. In particular, it is preferable to manufacture a touch panel with an antibacterial film by placing this antibacterial film on the surface of the image display area of ​​the touch panel. This antibacterial film provides good antibacterial properties, good anti-glare properties, and good image visibility, even when fingers or other objects frequently come into contact with the touch panel during operation.

[0090] The applications of touch panels with antibacterial film are not particularly limited and can be used as input devices and image display devices in electronic devices such as personal computers, mobile phones, game consoles, medical equipment, automated teller machines (ATMs), ordering machines, ticket vending machines, photocopiers, and car navigation systems. [Examples]

[0091] The present invention will be described in more detail below based on the following examples. The materials, amounts used, proportions, processing content, and processing procedures shown in the following examples can be modified as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted as being limited by the following examples.

[0092] [Example 1] [Preparation of antibacterial layer-forming composition] The following components were mixed in a container, and the resulting mixture was stirred to prepare an antibacterial layer-forming composition (Composition A-1). The solid content concentration of Composition A-1 was 49.9% by mass. Monomer 1: 23.4 parts by mass of "DPHA-76" manufactured by Toshin Oils Co., Ltd. (dipentaerythritol hexaacrylate, polyfunctional monomer, solids content 76% by mass) Monomer 2: 26.7 parts by mass of "KAYARAD PET-30" manufactured by Nippon Kayaku Co., Ltd. (a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate, a polyfunctional monomer) Monomer 3: 1.9 parts by mass of "NK Ester A-GLY-9E" (ethylene oxide 9 molar modified glycerin triacrylate) manufactured by Shin-Nakamura Chemical Industry Co., Ltd. • Antimicrobial agent particles: Zirconium phosphate-based silver antimicrobial agent (manufactured by Fuji Chemical Co., Ltd., average particle size 1.0 μm, silver content 3.7% by mass, zirconium phosphate-based carrier) 0.5 parts by mass • Light-diffusing particles: 1.8 parts by mass of "MX-300" manufactured by Soken Chemical Co., Ltd. (polymethyl methacrylate (PMMA), acrylic resin particles, average particle size 3.0 μm) • Polymerization initiator: 1.0 part by mass of BASF's "IRGACURE (Omnirad) 184" • Dispersant: 0.2 parts by mass of "DISPERBYK-180" manufactured by BYK chemie. • Surfactant: Neos Co., Ltd. "Futergent 650AC" (fluorine-based surfactant, solid content 30% by mass) 0.2 parts by mass • Solvent: 1-Methoxy-2-propanol 44.3 parts by mass

[0093] [Manufacturing of antibacterial films] Composition A-1 was applied to the surface of the easy-adhesion layer side of a 100 μm thick PET (Polyethylene terephthalate) substrate (manufactured by Fujifilm Corporation) which was formed by laminating easy-adhesion layers. The coated film was then heated at 60°C for 2 minutes to dry, and then 290 mJ / cm² was applied to the coated film. 2 The monomer was cured by irradiating it with ultraviolet light at a specified intensity to form an antibacterial layer B-1, thereby obtaining an antibacterial film B-1. The thickness of the formed antibacterial layer B-1 was 6.0 μm. The PET substrate was prepared in accordance with the example described in Japanese Patent Application Publication No. 2015-163457. The thickness of the antibacterial layer was measured by embedding the antibacterial film in resin, carving a cross-section with a microtome, and observing the carved cross-section with a scanning electron microscope. The thickness of the antibacterial layer was obtained by measuring the thickness at 10 arbitrary points in the antibacterial layer using the method described above and taking the arithmetic mean of the measured values. In the following examples and comparative examples, the thickness of the antibacterial layer was measured using the same method.

[0094] [Example 2] An antibacterial film was obtained using the same procedure as in Example 1, except that the amount of zirconium phosphate-based silver antibacterial agent used was changed to 1.0 part by mass.

[0095] [Example 3] An antibacterial film was obtained using the same procedure as in Example 1, except that the amount of zirconium phosphate-based silver antibacterial agent used was changed to 1.5 parts by mass.

[0096] [Example 4] An antibacterial film was obtained using the same procedure as in Example 1, except that the dispersant DISPERBYK-180 in Example 1 was replaced with Azisper PB881 (manufactured by Ajinomoto Fine Techno Co., Ltd.).

[0097] [Example 5] An antibacterial film was obtained using the same procedure as in Example 1, except that the dispersant DISPERBYK-180 in Example 2 was replaced with Azisper PB881 (manufactured by Ajinomoto Fine Techno Co., Ltd.).

[0098] [Comparative Example 1] Except for the absence of "MX-300" manufactured by Soken Chemical Co., Ltd., coating composition A-2 was prepared and a film was manufactured to obtain antibacterial film B-2 using the same procedure as in Example 1.

[0099] [Comparative Example 2] [Preparation of antibacterial layer-forming composition] The following components were mixed in a container, and the resulting mixture was stirred to prepare an antibacterial layer-forming composition (Composition A-3). The solid content concentration of Composition A-3 was 26.0% by mass. Monomer 1: 13.6 parts by mass of "DPHA-76" manufactured by Toshin Oils Co., Ltd. (dipentaerythritol hexaacrylate, polyfunctional monomer, solids content 76% by mass) Monomer 2: 10.4 parts by mass of "KAYARAD PET-30" manufactured by Nippon Kayaku Co., Ltd. (a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate, a polyfunctional monomer) • Monomer 3: 1.3 parts by mass of "NK Ester A-GLY-9E" (ethylene oxide 9 molar modified glycerin triacrylate) manufactured by Shin-Nakamura Chemical Industry Co., Ltd. • Antimicrobial agent particles: Zirconium phosphate-based silver antimicrobial agent (manufactured by Fuji Chemical Co., Ltd., average particle size 1.0 μm, silver content 3.7% by mass, zirconium phosphate-based carrier) 0.7 parts by mass • Light-diffusing particles: 2.0 parts by mass of "MX-300" manufactured by Soken Chemical Co., Ltd. (acrylic resin particles, average particle size 3.0 μm) • Polymerization initiator: 0.7 parts by mass of BASF's "IRGACURE (Omnirad) 184" • Dispersant: 3.3 parts by mass of "DISPERBYK-180" manufactured by BYK chemie. • Surfactant: Shin-Etsu Chemical Co., Ltd. "X-71-1203E" (urethane acrylate-based fluororesin composed of 2-isocyanate ethyl acrylate and ethylene glycol, solid content 20% by mass) 0.3 parts by mass • Solvent 1: Isopropyl alcohol 22.1 parts by mass • Solvent 2: 1-Methoxy-2-propylacetate 23.1 parts by mass • Solvent 3: 1-Methoxy-2-propanol 25.2 parts by mass

[0100] [Manufacturing of antibacterial films] Composition A-3, obtained above, was applied to the surface of the easy-adhesion layer side of a 100 μm thick PET substrate (manufactured by Fujifilm Corporation) which was formed by laminating easy-adhesion layers. Next, the coated film was heated at 60°C for 2 minutes to dry, and then 290 mJ / cm² was applied to the coated film. 2 The monomer was cured by irradiating it with ultraviolet light at a specified intensity to form an antibacterial layer B-3, thereby obtaining an antibacterial film B-3. The thickness of the formed antibacterial layer B-3 was 2.5 μm.

[0101] [Comparative Example 3] [Preparation of antibacterial layer-forming composition] The following components were mixed in a container, and the resulting mixture was stirred to prepare an antibacterial layer-forming composition (Composition A-4). • Hydrophilic monomer: Miramer M4004 (manufactured by Toyo Chemicals Co., Ltd.) 44 parts by mass • Hydrophilic monomer: Miramer M3150 (manufactured by Toyo Chemicals Co., Ltd.) 44 parts by mass • Crosslinking agent: A-DPH (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) 29 parts by mass • Polymerization initiator: IRGACURE® 184 (manufactured by BASF) 3 parts by mass • Antimicrobial agent particles: Silver ceramic particle dispersion (manufactured by Fuji Chemical Co., Ltd.) (zinc calcium phosphate carrier, average particle size 0.55 μm, solid content concentration 25% by mass) 40 parts by mass • Solvent: 1-Methoxy-2-propanol 90 parts by mass

[0102] [Manufacturing of antibacterial films] Composition A-4 was applied to the surface of the easy-adhesion layer side of a 100 μm thick PET substrate (manufactured by Fujifilm Corporation) which was formed by laminating easy-adhesion layers. The coated film was then heated at 60°C for 2 minutes to dry, and then 290 mJ / cm² was applied to the coated film. 2 The monomer was cured by irradiating it with ultraviolet light at a specified intensity to form an antibacterial layer B-4, thereby obtaining an antibacterial film B-4. The thickness of the formed antibacterial layer B-4 was 10 μm.

[0103] [Comparative Example 4] An antibacterial film was obtained using the same procedure as in Comparative Example 1, except that the amount of zirconium phosphate-based silver antibacterial agent used was changed to 1.0 part by mass.

[0104] [Comparative Example 5] An antibacterial film was obtained using the same procedure as in Comparative Example 1, except that the amount of zirconium phosphate-based silver antibacterial agent used was changed to 1.5 parts by mass.

[0105] [Comparative Example 6] An antibacterial film was obtained using the same procedure as in Comparative Example 4, except that the dispersant DISPERBYK-180 in Comparative Example 4 was replaced with Azisper PB881 (manufactured by Ajinomoto Fine Techno Co., Ltd.).

[0106] [Comparative Example 7] An antibacterial film was obtained using the same procedure as in Comparative Example 2, except that the amount of zirconium phosphate-based silver antibacterial agent used was changed to 1.0 part by mass.

[0107] [Comparative Example 8] An antibacterial film was obtained using the same procedure as in Comparative Example 2, except that the amount of zirconium phosphate-based silver antibacterial agent used was changed to 1.5 parts by mass.

[0108] [Comparative Example 9] An antibacterial film was obtained using the same procedure as in Comparative Example 7, except that the dispersant DISPERBYK-180 in Comparative Example 7 was replaced with Azisper PB881 (manufactured by Ajinomoto Fine Techno Co., Ltd.).

[0109] [Measurement and Evaluation] [Measurement of contact angle] The water contact angle and oleic acid contact angle on the surface of each antibacterial film obtained above, opposite to the substrate side of the antibacterial layer, were measured using a contact angle meter (Drop Master DM-501Hi, manufactured by Kyowa Interface Science Co., Ltd.) in accordance with the static droplet method of JIS R 3257:1999, under room temperature conditions of 20°C.

[0110] [Measurement of the average particle size of light-diffusing particles] The average particle size of light-diffusing particles in the antibacterial layer was determined by taking a cross-section of the antibacterial layer in each of the antibacterial films obtained above and measuring the diameter from the SEM (JEOL Ltd. "JSM-6700F") image. The particle size of 100 particles was measured, and the average value of these measurements was taken as the average particle size of the light-diffusing particles.

[0111] [Measurement of surface roughness Ra] The arithmetic surface roughness Ra (μm) of the surface of the antibacterial layer on the side opposite to the substrate side of each antibacterial film obtained above was determined by analyzing the shape of a 10 μm square area of ​​the surface of the antibacterial layer using a laser microscope (KEYENCE "VK-9500") in accordance with JIS B 0601:1994, and calculating the arithmetic surface roughness Ra (μm) using a general-purpose program attached to this device.

[0112] [Measurement of haze] The haze (%) of each antibacterial film obtained above was measured using a haze meter (NDH2000 haze meter manufactured by Nippon Denshoku Co., Ltd.).

[0113] [Evaluation of finger glide] The finger-slipperiness of the antibacterial films in each example and comparative example was evaluated by a sensory test in which a tester's finger was placed on the antibacterial film and rubbed horizontally for 60 mm, checking for any feeling of resistance or sticking. The evaluation of finger-slipperiness was performed based on the following criteria. "A": There was no catch. "B": There was a slight catch. "C": There was something that was bothering me. "D": There was a lot of resistance.

[0114] [Evaluation of glare suppression] The antibacterial films of each example and comparative example were laminated by attaching them to the surface of a tablet device (Apple's "iPhone® SE"). The glare of the displayed image observed through each antibacterial film was evaluated by a sensory test conducted by observing it from a distance of 30 cm from the front (normal direction to the display surface). The evaluation of glare suppression was performed based on the following criteria. "A": It lacked glare. "B": There was a slight glare. "C": It had a glare. "D": It had a very strong glare.

[0115] [Evaluation of fingerprint visibility] The antibacterial films of each example and comparative example were placed on black paper, and the fingerprints of an adult male's thumb were applied to the surface of each antibacterial film. The fingerprints were then observed from a distance of 30 cm from the front (normal direction to the surface of the black paper) to perform a sensory evaluation. The fingerprint visibility was evaluated based on the following criteria. "A": The fingerprint was difficult to see. "B": Fingerprints were somewhat visible. "C": Fingerprints were easily visible. "D": Fingerprints were very easy to see.

[0116] [Evaluation of fingerprint removal properties] The antibacterial films of each example and comparative example were placed on black paper. Fingerprints were then applied to the surface of each antibacterial film using the thumb of an adult male, which had been pressed against a tissue paper pre-impregnated with oleic acid. After that, the fingerprints applied to each antibacterial film were rubbed 10 times with a rolled-up tissue paper. The fingerprints were then observed from a distance of 30 cm from the front (normal to the surface of the black paper) and evaluated through a sensory test. Fingerprint removal performance was evaluated based on the following criteria. "A": The fingerprint was difficult to see. "B": Fingerprints were somewhat visible. "C": The fingerprint was visible. "D": The fingerprint was very visible.

[0117] 〔Evaluation of antiviral property〕 For the obtained antibacterial film, the antiviral property was evaluated using a method compliant with ISO 21702. Using influenza A virus as the test virus, the test virus concentration was adjusted to 1.6×10 7 (PFU / mL), 0.4 mL was inoculated onto each antibacterial film, and the average of the common logarithm of the infectious titer (Ut) (PFU / cm 2 ) after 24 hours and the average of the common logarithm of the infectious titer (At) (PFU / cm 2 ) after 24 hours inoculated onto an untreated PET film instead of each antibacterial film were measured. From the obtained values, the antiviral activity value R = Ut - At was determined, and the antiviral property was evaluated as anti-influenza virus property. Also, except that the above influenza A virus was changed to the novel coronavirus, the antiviral property was evaluated as anti-novel coronavirus property in the same procedure as above.

[0118] Table 1 below shows the composition, measurement results and evaluation results of the antibacterial films manufactured in each example and comparative example. In the table, the column of "A / B" represents the ratio of the water contact angle to the oleic acid contact angle (water contact angle / oleic acid contact angle). For the columns of "Formula (1)" and "Formula (2)", the case where each formula is satisfied is designated as "A", and the case where each formula is not satisfied is designated as "B".

[0119]

Table 1

[0120] From the results shown in Table 1, it was confirmed that this antibacterial film is excellent in all of finger slipperiness, glare suppression, fingerprint visibility and fingerprint removability, and also excellent in antiviral property.

Explanation of symbols

[0121] 101 Base material 102 Antibacterial layer 110 Antibacterial Film

Claims

1. Substrate and An antibacterial film having at least one antibacterial layer disposed on the substrate, The antibacterial layer contains a binder, light-diffusing particles, and antibacterial agent particles. The ratio of the water contact angle on the surface of the antibacterial layer to the oleic acid contact angle on the surface opposite to the substrate side is 7.0 or greater. An antibacterial film that satisfies the relationships of equations (1) and (2), where x μm is the arithmetic surface roughness of the surface of the antibacterial layer opposite to the substrate side, and Ps μm is the average particle size of the light-diffusing particles. 0.10 ≦ x ≦ 0.20 (1) 7.7x+1.0 ≦ Ps ≦ 7.7x+3.0 (2)

2. The antibacterial film according to claim 1, wherein the haze is 10% or less.

3. The antibacterial film according to claim 1 or 2, wherein the light-diffusing particles are acrylic resin particles.

4. The antibacterial film according to any one of claims 1 to 3, wherein the content of the light-diffusing particles is 1 to 15% by mass with respect to the total mass of the antibacterial layer.

5. The antibacterial film according to any one of claims 1 to 4, wherein the antibacterial agent particles contain silver.

6. The antibacterial film according to any one of claims 1 to 5, wherein the antibacterial agent particles contain a silver-supported carrier.

7. The antibacterial film according to any one of claims 1 to 6, wherein the content of the antibacterial agent particles is 0.1 to 20% by mass with respect to the total mass of the antibacterial layer.

8. The antibacterial film according to any one of claims 1 to 7, wherein the thickness of the antibacterial layer is 0.01 to 10 μm.

9. The antibacterial film according to any one of claims 1 to 8, wherein the material constituting the substrate is at least one selected from the group consisting of polyethylene terephthalate, triacetylcellulose, and polycarbonate.

10. The antibacterial film according to any one of claims 1 to 9, wherein the antibacterial layer is disposed on one surface of the substrate, and an adhesive layer is disposed on the surface of the substrate opposite to the surface on which the antibacterial layer is disposed.

11. A touch panel comprising an antibacterial film according to any one of claims 1 to 10.

12. A copier comprising the antibacterial film described in any one of claims 1 to 10.

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