JP5804206B2 - Antibacterial transparent film and antibacterial adhesive sheet - Google Patents

Description

The present invention relates to an antibacterial transparent film and an antibacterial pressure-sensitive adhesive sheet.
This invention claims priority based on Japanese Patent Application No. 2012-177395 for which it applied to Japan on August 9, 2012, and uses the content here.

A hard coat film having a hard coat layer may be attached to the surface of a display, a touch panel or the like for the purpose of increasing the surface hardness.
In recent years, products related to daily life have been given antibacterial properties, and hard coat films have also been proposed that have antibacterial properties.

  As a hard coat film having antibacterial properties, for example, Patent Document 1 has a curable resin layer containing an antibacterial agent having an average particle diameter of 0.1 to 50 μm on the surface of a plastic substrate, and the curable resin The hard coat film whose arithmetic mean roughness (Ra) of the surface of the layer side is 0.1-3.0 micrometers is disclosed. According to Patent Document 1, Ra is 0.1 μm or more, and the antibacterial agent having an average particle diameter of 0.1 μm or more is used, whereby the antibacterial agent is completely embedded in the curable resin layer. It is disclosed that it can prevent and exert an antibacterial effect.

Japanese Patent No. 3577145

By the way, as described above, since the hard coat film is attached to the surface of a display or a touch panel, it is required to have excellent transparency as well as hardness.
However, the hard coat film described in Patent Document 1 cannot provide sufficient transparency.

  As a method for improving the transparency, for example, the Ra value on the film surface can be lowered. However, in the case of the hard coat film described in Patent Document 1, when the Ra value is less than 0.1 μm, the antibacterial agent is completely embedded in the curable resin layer, and the antibacterial effect is not exhibited. Thus, it was difficult to achieve both antibacterial properties and transparency.

  An object of the present invention is to provide an antibacterial transparent film that can sufficiently exhibit an antibacterial effect and has excellent transparency, and an antibacterial pressure-sensitive adhesive sheet provided with the antibacterial transparent film.

The present invention has the following aspects.
[1] A plastic substrate and a curable resin layer containing an antibacterial agent provided on the plastic substrate, the average particle diameter of the antibacterial agent is 0.5 to 100 nm, and JIS B0601 The antibacterial transparent film whose arithmetic mean roughness (Ra) of the surface by the side of the said curable resin layer measured based on is less than 0.1 micrometer.
[2] The antibacterial transparent film according to [1], wherein the antibacterial agent is an inorganic oxide having an antibacterial metal component supported thereon.
[3] The antibacterial transparent film according to [1] or [2], wherein the curable resin layer is provided on the outermost layer of the antibacterial transparent film.
[4] The antibacterial transparent film according to any one of [1] to [3], wherein the curable resin layer includes a hard coat layer.
[5] Any of the above [1] to [4], wherein the haze value measured based on JIS K7136 is 2% or less, and the total light transmittance measured based on JIS K7361 is 90% or more. The antibacterial transparent film according to one item.
[6] An antibacterial adhesive sheet in which an adhesive layer is provided on the surface of the antibacterial transparent film according to any one of [1] to [5] on the plastic substrate side.

That is, the present invention has the following aspects.
<1> An antibacterial transparent film comprising a plastic substrate and a curable resin layer laminated on at least one surface of the plastic substrate, wherein the curable resin layer contains an antibacterial agent, An antibacterial agent having an average particle diameter of 0.5 to 100 nm and an arithmetic average roughness (Ra) measured in accordance with JIS B0601-1982 of the surface of the curable resin layer of less than 0.1 μm. Transparent film;
<2> The antibacterial transparent film according to <1>, wherein the antibacterial agent is an inorganic oxide supporting an antibacterial metal component;
<3> The antibacterial transparent film according to <1> or <2>, wherein the curable resin layer is provided on the outermost layer of the antibacterial transparent film;
<4> The antibacterial transparent film according to any one of <1> to <3>, wherein the curable resin layer is a hard coat layer;
<5> The antibacterial transparent film has a haze value measured on the basis of JIS K7136 of 2% or less, and a total light transmittance measured on the basis of JIS K7361 of 90% or more, <1> to <4> The antibacterial transparent film according to any one of the above;
<6> The antibacterial transparent film according to any one of <1> to <5> and an adhesive layer, and the plastic substrate of the antibacterial transparent film is laminated on the adhesive layer. , Antibacterial adhesive sheet.

  ADVANTAGE OF THE INVENTION According to this invention, the antibacterial transparent film which can fully exhibit an antibacterial effect and has outstanding transparency, and the antibacterial adhesive sheet provided with the said antibacterial transparent film can be provided.

It is sectional drawing which shows an example of an antibacterial transparent film. It is sectional drawing which shows the other example of an antimicrobial transparent film. It is sectional drawing which shows the other example of an antimicrobial transparent film. It is sectional drawing which shows the other example of an antimicrobial transparent film. It is sectional drawing which shows the other example of an antimicrobial transparent film. It is sectional drawing which shows an example of an antibacterial adhesive sheet. It is sectional drawing which shows the other example of an antibacterial adhesive sheet.

Hereinafter, the present invention will be described in detail.
[Antimicrobial transparent film]
FIG. 1 is a cross-sectional view showing a configuration of an antibacterial transparent film which is an embodiment of the present invention.
The antibacterial transparent film 10 of this example has a plastic substrate 11 and a curable resin layer 12 containing an antibacterial agent laminated on the plastic substrate 11. The curable resin layer 12 is provided on the outermost layer of the antibacterial transparent film 10 of this embodiment.

<Plastic substrate>
The plastic substrate 11 is not particularly limited as long as it has transparency, but the transparency of the plastic substrate 11 is preferably such that the total light transmittance measured based on JIS K7361 is 85% or more. . That is, in one embodiment of the present invention, the transparency of the plastic substrate 11 is measured by using a test piece of 3 × 3 cm or more, and using CIE standard light D65 as a light source as a light source. The total light transmittance defined as the ratio of the total transmitted light beam integrated by the integrating sphere to the light beam is preferably 85% or more.

Examples of the plastic substrate 11 include polyethylene terephthalate (PET) film, polyethylene naphthalate film, polypropylene terephthalate film, polybutylene terephthalate film, polypropylene naphthalate film, polyethylene film, polypropylene film, cellophane, diacetylcellulose film, and triacetylcellulose. Film, acetylcellulose butyrate film, polyvinyl chloride film, polyvinylidene chloride film, polyvinyl alcohol film, ethylene-vinyl acetate copolymer film, polystyrene film, polycarbonate film, polymethylpentene film, polysulfone film, polyether ether ketone film , Polyethersulfone fill , Polyetherimide film, a polyimide film, a fluororesin film, a polyamide film, and acrylic resin film.
Among these, a PET film is preferable from the viewpoints of transparency, weather resistance, solvent resistance, rigidity, cost, and the like. The breaking strength of the PET film is preferably 150 MPa or more, the breaking elongation is preferably 100% or more, and the thermal shrinkage ratio of the PET film by heat treatment at 150 ° C. for 30 minutes is 1.5. % Or less is preferable. The plastic substrate 11 may contain various additives. Examples of the additive include antioxidants, heat stabilizers, ultraviolet absorbers, organic particles, inorganic particles, pigments, dyes, antistatic agents, nucleating agents, and coupling agents.
The plastic substrate 11 may be subjected to a surface treatment in order to improve adhesion with the curable resin layer 12. Examples of the surface treatment include surface roughening treatment such as sand blast treatment and solvent treatment, corona discharge treatment, chromic acid treatment, flame treatment, hot air treatment, ozone / ultraviolet irradiation treatment, and the like.
The thickness of the plastic substrate 11 is preferably 10 to 500 μm, and more preferably 20 to 300 μm. If the thickness of the plastic substrate 11 is 10 μm or more, the antibacterial transparent film is hardly broken, and if it is 500 μm or less, the transparency can be maintained well and the handleability is also excellent.

<Curable resin layer>
The curable resin layer 12 is a layer containing a binder resin and an antibacterial agent. The binder resin includes at least a curable resin. Here, the “curable resin layer” means a layer obtained by curing a binder resin.
As will be described in detail later, the curable resin layer 12 is obtained by, for example, applying a curable resin layer forming composition containing an antibacterial agent and a binder resin to the plastic substrate 11 and drying and curing the coating film. . Hereinafter, each component which comprises the curable resin layer 12 is demonstrated.

(Antimicrobial agent)
The average particle diameter of the antibacterial agent contained in the curable resin layer 12 is 0.5 to 100 nm, preferably 5 to 80 nm, and more preferably 8 to 40 nm.
As will be described in detail later, the arithmetic average roughness (Ra) of the surface of the antibacterial transparent film 10 on the side of the curable resin layer 12 (hereinafter, this surface is also referred to as “the surface of the antibacterial transparent film”) is 0.1 μm. Is less than. Even if the average particle diameter of the antibacterial agent is 100 nm or less, the present inventor does not impair the transparency when the surface Ra of the antibacterial transparent film 10 is less than 0.1 μm, and the antibacterial agent is a curable resin. It has been found that since it is not buried in the layer 12, it can exhibit a sufficient antibacterial effect, and further, the antibacterial agent does not fall off from the surface. However, when the average particle diameter of the antibacterial agent is less than 0.5 nm, it is difficult to produce the antibacterial agent. Here, “the antibacterial agent is buried” means that the whole antibacterial agent is covered with the binder resin constituting the curable resin layer 12. That is, if the average particle diameter of the antibacterial agent is 0.5 to 100 nm and the surface Ra of the antibacterial transparent film 10 is less than 0.1 μm, the antibacterial agent is not buried and a part of the antibacterial agent is embedded. The antibacterial transparent film 10 is preferably exposed on the surface and can exhibit a high antibacterial effect.
In addition, “sufficient antibacterial effect” means that the antibacterial activity value against Staphylococcus aureus and Escherichia coli is 2.0 or more based on JIS Z2801. That is, the antibacterial activity value defined as the logarithmic value of the number of bacteria after 24-hour culture of unprocessed product divided by the number of bacteria after 24-hour culture of antibacterial processed product is It means 2.0 or more (99% or more death rate).

Furthermore, the present inventors have found that when the average particle size of the antibacterial agent exceeds 100 nm, a sufficient antibacterial effect cannot be obtained. If the antibacterial action of the antibacterial agent is weak, the content of the antibacterial agent may be increased in order to obtain a sufficient antibacterial effect. However, as will be described in detail later, when the content of the antibacterial agent is increased, the transparency of the antibacterial transparent film 10 obtained is lowered, or the curable resin layer 12 is yellowed. In the present invention, by using an antibacterial agent having an average particle size of 0.5 nm to 100 nm, a sufficient antibacterial effect can be exhibited with a content that does not cause yellowing of the curable resin layer 12.
Moreover, since Ra on the surface of the antibacterial transparent film 10 is less than 0.1 μm, the antibacterial agent easily falls off the curable resin layer 12 when the average particle diameter of the antibacterial agent exceeds 100 nm.

The average particle diameter of the antibacterial agent is a value measured by the following method.
Using a transmission electron microscope, the maximum length of the antibacterial agent particle image (Dmax: maximum length at two points on the contour of the particle image) and the maximum length vertical length (DV-max: two parallel to the maximum length) The shortest length between the two straight lines when the particle image is sandwiched between the two straight lines is measured, and the geometric mean value (Dmax × DV-max) ^½ is taken as the particle diameter. With this method, the particle size of any 100 antibacterial agents is measured, and the arithmetic average value is taken as the average particle size.

Examples of antibacterial agents include organic antibacterial agents and inorganic antibacterial agents.
Examples of the organic antibacterial agent include hinokitiol, quaternary ammonium salt, TBZ (2- (4-thiazolyl) benzimidazole), OPP (o-phenylphenol) and the like.
The inorganic antibacterial agent is preferably an inorganic oxide carrying an antibacterial metal component. Although the antibacterial metal component alone can be contained in the curable resin layer 12 as an antibacterial agent, the use of an inorganic oxide supporting the antibacterial metal component as the antibacterial agent provides a superior antibacterial effect in a small amount. It is more preferable because it can be expressed.

Examples of the inorganic oxide include single inorganic oxides such as SiO ₂ , TiO ₂ , ZrO ₂ , Al ₂ O ₃ , Fe ₂ O ₃ , Sb ₂ O ₃ , WO ₃ , and CeO ₂ , and SiO ₂ -Al. ₂ O ₃ , SiO ₂ —TiO ₂ , SiO ₂ —ZrO ₂ , Al ₂ O ₃ —TiO ₂ , Al ₂ O ₃ —CeO ₂ , TiO ₂ —CeO ₂ , TiO ₂ —ZrO ₂ , SiO ₂ —TiO ₂ — composite oxides such as _{ZrO 2, SiO 2 -TiO 2 -CeO} 2 and the like, can be used one or more of these. Of these, SiO ₂ , TiO ₂ , and Al ₂ O ₃ are preferable, and SiO ₂ is particularly preferable in terms of excellent transparency.

The average particle size of the inorganic oxide is preferably 0.3 to 90 nm, more preferably 5 to 60 nm, and further preferably 6 to 30 nm. If the average particle diameter of the inorganic oxide is 0.3 nm or more, the antibacterial agent can be sufficiently exerted without being embedded in the curable resin layer 12. On the other hand, if the average particle size of the inorganic oxide is 90 nm or less, an antibacterial agent having an average particle size of 100 nm or less is easy to produce, and therefore the antibacterial agent is unlikely to fall off from the curable resin layer 12.
The average particle diameter of the inorganic oxide is a value measured by the same method as the average particle diameter of the antibacterial agent described above.

  As the antibacterial metal component, an antibacterial metal component used as an inorganic antibacterial agent can be used. Specifically, silver, copper, zinc, lead, tin, bismuth, cadmium, chromium, mercury, nickel, cobalt, etc. One or more of these can be used. Among these, silver, copper, and zinc are suitable as antibacterial metal components because they have deodorizing properties, antifungal properties, and algal barrier properties in addition to antibacterial properties, and are excellent in handleability. These antibacterial metal components are preferably supported on the above-mentioned inorganic oxides from the viewpoint of easy development of antibacterial properties.

  The content of the antibacterial metal component in the antibacterial agent, that is, the inorganic oxide supporting the antibacterial metal component, that is, the loading ratio of the antibacterial metal component is 0.001 mass relative to the total mass of the antibacterial agent. % Or more, more preferably 0.001 to 10% by mass, and even more preferably 0.05 to 5% by mass. When the content of the antibacterial metal component is 0.001% by mass or more, a sufficient antibacterial effect is easily obtained.

  The method for supporting the antibacterial metal component on the inorganic oxide is not particularly limited. For example, a colloidal particle having a negative charge is produced by attaching an inorganic compound to the surface of the inorganic oxide, and the colloidal particle is coated with the antibacterial metal By attaching the components, an antibacterial agent in which an antibacterial metal component is supported on an inorganic oxide can be obtained. That is, in one embodiment of the present invention, “supporting an antibacterial metal component on an inorganic oxide” means that the antibacterial metal component described above is applied to the surface of the inorganic oxide colloidally treated so as to have a negative charge. Means to adhere.

The inorganic oxide is not particularly limited as long as it has a negative charge, and examples thereof include SiO ₂ —Al ₂ O ₃ , SiO ₂ —TiO _2, and one or more of these can be used. . Of these, SiO ₂ —Al ₂ O ₃ is preferable.
Among SiO ₂ -Al ₂ O _3, is _SiO 2 _-Al 2 _{O 3} in particular mass ratio _{(SiO 2 / Al 2 O 3} ) is 1 / 1-5 / 1 preferred. A mass ratio within the above range is preferable because the antibacterial metal component can be sufficiently adhered to the colloid-treated inorganic oxide.

  The content of the antibacterial metal component is preferably 0.1 to 100 parts by mass and more preferably 1 to 30 parts by mass with respect to 100 parts by mass of the inorganic oxide. When the content of the antibacterial metal component is 0.1 parts by mass or more, sufficient antibacterial activity is obtained. On the other hand, even if the content of the antibacterial metal component exceeds 100 parts by mass, the antibacterial activity reaches its peak. Therefore, considering the manufacturing cost, the content of the antibacterial metal component is preferably 100 parts by mass or less.

  As the inorganic oxide used as the carrier, those having a porous structure containing a large number of pores (porous) of about 0.1 to 1.0 nm (for example, zeolite) are well known. However, when an antibacterial metal component is supported on an inorganic oxide having such a porous structure, the supported component adheres not only to the surface of the inorganic oxide but also to the porous interior, As a result, the contact rate between the antibacterial metal component and the bacterium is reduced and the antibacterial effect is lowered, so that a large amount of the antibacterial metal component is required for the expression of the antibacterial effect. In addition, zeolite is known to have problems of discoloration and high opacity over time, and is not suitable for application to an antibacterial transparent film. In response to such a problem, the antibacterial transparent film of the present invention is supported by treating the inorganic oxide so that the antibacterial metal component selectively adheres to the surface of the inorganic oxide. The surface exposure rate is increased, and a sufficient antibacterial effect can be obtained with a smaller amount of antibacterial metal component.

Hereinafter, an example of a method for producing an antibacterial agent will be specifically described by taking as an example the case where SiO ₂ —Al ₂ O ₃ is employed as the inorganic compound.
First, inorganic oxide particles such as SiO ₂ are suspended in water. The concentration of the inorganic oxide in the suspension is not particularly limited as long as it has the effect of the present invention, but is about 1 to 20% by mass with respect to the total mass of the suspension. Next, an alkaline aqueous solution (such as an aqueous sodium hydroxide solution) is added to the suspension so that the suspension has a pH of 10 to 11. By adjusting the pH of the suspension to be 10 to 11, a part of the surface of the inorganic oxide is dissolved and the reactivity with the above-described inorganic oxide is increased. Next, the suspension after adjusting the pH as necessary is heated to about 60 to 98 ° C.
Next, a predetermined amount of sodium aluminate aqueous solution and a predetermined amount of water glass are simultaneously added to the suspension while stirring, and the mixture is heated and aged at 60 to 98 ° C. for 0.5 to 5 hours to form SiO 2 on the surface of the inorganic oxide. depositing a ₂ -Al ₂ O ₃ hydrate. Thereafter, the alkali is removed by carrying out a dealkalization treatment using a cation exchange resin or the like, and an inorganic oxide colloidally treated so as to have a negative charge (hereinafter referred to as “colloid particle-like inorganic oxide”). Sometimes get).
Separately, an antibacterial metal component is dissolved in ammonia water, and the antibacterial metal component [Cu (NH ₃ ) ₄ ] ²⁺ , [Ag (NH ₃ ) ₂ ] ⁺ , [Zn (NH ₃ ) ₄ ] ^2+, etc. Prepare an aqueous complex salt solution and add it to the colloidal particle-like inorganic oxide obtained above while stirring to attach the antibacterial metal component to the colloidal particle-like inorganic oxide. A suspension containing the antibacterial agent carried on is obtained. Thereafter, if necessary, a silane coupling agent or the like may be added and heat-aged.
The suspension of the antibacterial agent thus obtained or the suspension of the antibacterial agent after heat aging is spray-dried and fired to obtain a particulate antibacterial agent.

  The content of the antibacterial agent in the curable resin layer 12 is preferably 0.05 to 20% by mass, and 0.1 to 10% by mass in the total mass of the solid content of the curable resin layer forming composition. More preferably, it is 0.2-5 mass%. If the content of the antibacterial agent is 0.05% by mass or more, a sufficient antibacterial effect can be obtained. On the other hand, when the content of the antibacterial agent exceeds 20% by mass, the transparency of the obtained antibacterial transparent film tends to decrease, or the curable resin layer 12 tends to yellow.

  In addition, although mentioned later in detail, the curable resin layer 12 may contain components (other components) other than the antibacterial agent and the binder resin. However, when the curable resin layer 12 includes a reactive fluorine agent such as a fluorine-based antifouling agent as another component, the reactive fluorine agent bleeds out to the surface of the curable resin layer 12 over time. The action of the agent may be hindered. Therefore, when the curable resin layer 12 contains a reactive fluorine agent, it is preferable to increase the content of the antibacterial agent. For example, when the composition for forming a curable resin layer contains a reactive fluorine agent in an amount of 0.1% by mass with respect to the total mass of the composition for forming a curable resin layer, It is preferable that content of an antibacterial agent is 0.4 mass% or more with respect to the total mass of solid content of the composition for curable resin layer formation. When the content of the antibacterial agent is 0.4% by mass or more, the antibacterial effect can be sufficiently exhibited even if the reactive fluorine agent bleeds out on the surface of the curable resin layer 12. In addition, the content of the antibacterial agent when the composition for forming a curable resin layer contains 0.1% by mass of a reactive fluorine agent is preferably 20% by mass or less from the viewpoint of the above-described decrease in transparency and prevention of yellowing. .

(Binder resin)
The binder resin used for the curable resin layer 12 includes at least a curable resin. Examples of the curable resin include a thermosetting resin and an active energy ray curable resin.
Examples of the thermosetting resin include phenol resin, urea resin, diallyl phthalate resin, melamine resin, unsaturated polyester resin, polyurethane resin, epoxy resin, amino alkyd resin, silicon resin, polysiloxane resin, and the like.

  As the active energy ray-curable resin, a polymer obtained by polymerizing a polyfunctional (meth) acrylic monomer is preferable. Since such a polymer is a hard acrylic polymer having a crosslinked structure, it is excellent in surface hardness, transparency, scratch resistance and the like.

“Polyfunctional” means having two or more polymerizable unsaturated groups in its structure, and “(meth) acrylic monomer” is a compound having at least a (meth) acryloyl group as a polymerizable unsaturated group. It is. “(Meth) acryloyl group” means an acryloyl group or a methacryloyl group.
Examples of the polyfunctional (meth) acrylic monomer include the following monomers.
Dipropylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polyethylene glycol (mass average molecular weight 600) di (meth) acrylate, propylene oxide modified neopentyl glycol Bifunctional (meth) acrylates such as di (meth) acrylate, modified bisphenol A di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, polyethylene glycol (mass average molecular weight 400) di (meth) acrylate;
Trifunctional (meth) acrylates such as pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane ethoxytri (meth) acrylate, polyether tri (meth) acrylate, glycerin propoxytri (meth) acrylate, etc. ;
Tetrafunctional (meth) acrylates such as pentaerythritol tetra (meth) acrylate, pentaerythritol ethoxytetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate;
5 or more functional (meth) acrylates such as dipentaerythritol penta (meth) acrylate, propionic acid-modified dipentaerythritol penta (meth) acrylate, dipentaerythritol monohydroxypenta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, etc. etc.
These polyfunctional (meth) acrylic monomers may be used individually by 1 type, and may use 2 or more types together.

The polyfunctional (meth) acrylic monomer is mainly composed of a tetrafunctional or higher functional (meth) acrylic monomer (preferably a pentafunctional or higher functional (meth) acrylic monomer) and a 2-3 functional (meth) acrylic monomer as a subcomponent. It is preferable that That is, the proportion of the tetrafunctional or higher (meth) acrylic monomer is preferably 50% by mass or more and less than 95% by mass, and more preferably 60% by mass or more and less than 90% by mass with respect to the total mass of the polyfunctional (meth) acrylic monomer. preferable. Moreover, the ratio of the 2-3 trifunctional (meth) acrylic monomer is preferably 5% by mass or more and less than 50% by mass, and more preferably 10% by mass or more and less than 40% by mass with respect to the total mass of the polyfunctional (meth) acrylic monomer. preferable.
Among these, a tetra- or higher functional (meth) acrylic monomer contributes to an improvement in the hardness of the cured resin layer, and a 2-3 functional (meth) acrylic monomer contributes to an improvement in the flexibility of the cured resin layer. Therefore, as the binder resin, the tetrafunctional or higher functional (meth) acrylic monomer is contained in an amount of 50% by mass or more and less than 95% by mass with respect to the total mass of the polyfunctional (meth) acrylic monomer, and the 2-3 functional (meta). When the acrylic monomer is contained in an amount of 5% by mass or more and less than 50% by mass with respect to the total mass of the polyfunctional (meth) acrylic monomer, the resulting curable resin layer 12 has high hardness and appropriate flexibility, and is scratch resistant. As will be described later in detail, the curable resin layer 12 can be a hard coat layer.
Among these, from the viewpoint of transparency and durability, the curable resin layer is preferably a polymer obtained by polymerizing an active energy ray-curable “(meth) acrylic monomer”.

  The content of the curable resin in the curable resin layer 12 is preferably 30 to 98% by mass, and 50 to 95% by mass with respect to the total mass of the solid content of the curable resin layer forming composition. More preferably. If content of curable resin is 30 mass% or more, when making curable resin layer 12 into a hard-coat layer, sufficient hard-coat performance will be easy to be obtained. On the other hand, if the content of the curable resin is 98% by mass or less, an auxiliary agent such as a photopolymerization initiator or a leveling agent can be added as an optional component, and it is difficult for curing failure to occur. This is preferable because the coating suitability of the resin layer forming composition can be easily maintained.

The binder resin may be composed of only the curable resin described above, or may include other resins. Although mentioned later in detail, when making the curable resin layer 12 into an antireflection layer, it is preferable to contain a silicone compound and a fluorine-containing resin as other resin. In particular, when a silicone compound is included, a curable resin layer 12 having a low refractive index can be obtained.
Examples of the silicone compound include alkylene groups (ethylene group, propylene group, butylene group, hexylene group, octylene group, etc.), cycloalkylene groups (cyclohexylene group, etc.), arylene groups (phenylene group, etc.), and alkyl groups. (Methyl group, ethyl group, propyl group, butyl group, hexyl group, octyl group, decyl group, etc.), cycloalkyl group (cyclohexyl group, etc.), alkenyl group (vinyl group, allyl group, propenyl group, butenyl group, Hexenyl groups, etc.), aralkyl groups (aryl groups such as phenyl and tolyl groups, benzyl groups, phenylethyl groups, etc.) and the like.

(Other ingredients)
The curable resin layer forming composition preferably contains a photopolymerization initiator together with the polyfunctional (meth) acrylic monomer and the antibacterial agent in order to promote the curing.
Known photopolymerization initiators can be used such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2- Dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4 -(Methylthio) phenyl] -2-morpholino-propan-1-one, 4- (2-hydroxyethoxy) phenyl-2 (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4 4'-diethylaminobenzophenone, propiophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tertiarybutylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, Examples include 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal, p-dimethylamine benzoate. These photoinitiators may be used individually by 1 type, and may be used in combination of 2 or more type.
0.5-10 mass% is preferable with respect to the total mass of solid content of the composition for curable resin layer formation, and, as for the compounding quantity of a photoinitiator, 2-8 mass% is more preferable. If it is 0.5% by mass or more, poor curing of the resin hardly occurs. Even if it mixes exceeding 10 mass%, the hardening acceleration | stimulation effect corresponding to a compounding quantity is not acquired, but cost also becomes high. Moreover, it may remain in the cured product and cause yellowing or bleeding out.

  In addition to the photopolymerization initiator, a photosensitizer can be further contained. Examples of the photosensitizer include n-butylamine, triethylamine, and tri-n-butylphosphine.

The composition for curable resin layer formation may contain other components other than the above as long as the effects of the present invention are not impaired. For example, a known additive used for imparting other functions (antifouling properties, antistatic properties, ultraviolet shielding properties, etc.) other than antibacterial properties to the curable resin layer can be contained. Examples of such additives include reactive fluorine agents (for example, fluorine-based antifouling agents for imparting antifouling properties and fluorine-based lubricants for imparting slipperiness); and improving coating suitability. Leveling agent for: metal oxide fine particles for imparting antistatic performance (excluding antibacterial agents), antistatic resin, conductive polymer; metal oxide fine particles for imparting ultraviolet shielding properties (for example, titanium oxide) However, antibacterial agents are excluded.), Ultraviolet absorbers; light stabilizers and the like.
The antibacterial agent described above is in the form of particles, but an oily organic antibacterial agent may be used in combination with the antibacterial agent described above.

When the curable resin layer 12 is used as an antireflection layer, the curable resin layer forming composition preferably includes particles having a balloon (hollow) structure for lowering the refractive index.
The material of the balloon particles is not particularly limited, such as an organic system such as styrene-acrylic resin or an inorganic system such as silica, but silica is particularly preferable from the viewpoint of transparency and strength for maintaining voids.
The average particle diameter of the hollow silica is preferably 5 to 180 nm, and more preferably 30 to 100 nm. If the average particle diameter of the hollow silica is 5 nm or more, the refractive index of the curable resin layer 12 can be easily lowered. If the average particle diameter of the hollow silica is 180 nm or less, the curable resin layer 12 can be densely filled with the hollow silica. In addition, the said average particle diameter is a value measured by the observation image of a transmission electron microscope or a scanning electron microscope similarly to the average particle diameter of the above-mentioned antibacterial agent.
Moreover, since hollow silica has a tendency to reduce a refractive index, so that there are many hollow parts, that whose outer shell thickness is thin compared with an average particle diameter is preferable. Here, the outer shell of hollow silica having voids inside can be observed with a transmission electron microscope (TEM). The hollow portion can also be observed with a transmission electron microscope. In one aspect of the present invention, when the curable resin layer 12 contains hollow silica, the bulk density of the hollow silica is 0.01 to 0.00 in order to reduce the refractive index of the curable resin layer 12. It is preferably 15 g / ml.

  When the curable resin layer 12 contains an inorganic silicon-containing compound, the content is preferably 20 to 80% by mass relative to the total mass of the solid content of the curable resin layer forming composition, It is more preferable that it is 30-70 mass%. When the content of the inorganic silicon-containing compound is 20% by mass or more, the refractive index of the curable resin layer 12 is sufficiently low, and high light transmittance is easily obtained. On the other hand, if the content of the inorganic silicon-containing compound is 80% by mass or less, it is easy to suppress the shortage of the binder resin in the curable resin layer 12.

The curable resin layer forming composition may contain a solvent.
Examples of the solvent include methanol, ethanol, isopropanol, acetone, methyl ethyl ketone, toluene, n-hexane, n-butyl alcohol, methyl isobutyl ketone, methyl butyl ketone, ethyl butyl ketone, cyclohexanone, ethyl acetate, butyl acetate, propylene glycol monomethyl. Ether acetate, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, N-methyl-2-pyrrolidone and the like are used. These may be used alone or in combination of two or more.
In particular, since it is possible to reduce coating unevenness, it is preferable to use two or more solvents having different evaporation rates in combination. For example, it is preferable to use a mixture of at least two selected from methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, and propylene glycol monomethyl ether.

(Function of curable resin layer)
The curable resin layer 12 can be a hard coat layer or an antireflection layer depending on the composition of the binder resin.
When the curable resin layer 12 is a hard coat layer, the thickness of the curable resin layer 12 is preferably 1 to 10 μm, and more preferably 2 to 8 μm. If the thickness of the curable resin layer 12 is 1 μm or more, sufficient hard coat performance is easily obtained. If the thickness of the curable resin layer 12 is 10 μm or less, curl control becomes easy, and adhesion to the plastic substrate 11, transparency, and the like become better. Here, “curl” means “warping” of the antibacterial transparent film due to curing shrinkage of the cured resin layer. The thickness of the curable resin layer 12 is a value obtained by subtracting the thickness of the plastic substrate from the thickness of the antibacterial transparent film as measured using a dial gauge.
Further, the refractive index of the curable resin layer 12 is preferably 1.40 to 2.00, and more preferably 1.45 to 1.80. If the refractive index of the curable resin layer 12 is within the above range, it is easy to control the reflection of light.
When the curable resin layer 12 is a hard coat layer, the antibacterial transparent film 10 shown in FIG. 1 can be used as a hard coat film.

On the other hand, when the curable resin layer 12 is an antireflection layer, the thickness of the curable resin layer 12 is preferably larger than the average particle diameter of the antibacterial agent, preferably 50 to 150 nm, more preferably 60 to 140 nm, 80 ˜120 nm is particularly preferred. When the thickness of the curable resin layer 12 is 50 nm or more, an antireflection effect due to light interference is easily obtained. If the thickness of the curable resin layer 12 is 150 nm or less, the adhesion with the plastic substrate 11 becomes better.
The refractive index of the curable resin layer 12 is preferably 1.25 to 1.45, more preferably 1.30 to 1.40. If the refractive index of the curable resin layer 12 is within the above range, it is easy to control the reflection of light.
When the curable resin layer 12 is an antireflection layer, the antibacterial transparent film 10 shown in FIG. 1 can be used as an antireflection film.

<Physical properties>
Arithmetic mean roughness (Ra) measured in accordance with JIS B0601-1982 on the surface of the curable resin layer 12 side of the antibacterial transparent film 10 (surface of the antibacterial transparent film) (hereinafter referred to as “Ra ₁ ”) Is less than 0.1 μm, and preferably 0.05 μm or less. If Ra on the surface of the antibacterial transparent film 10 is less than 0.1 μm, the transparency is improved. The lower limit of Ra on the surface of the antibacterial transparent film 10 is not particularly limited as long as it has the effect of the present invention, but is preferably 0.001 μm or more.
Moreover, in another aspect of the present invention, the arithmetic average roughness (hereinafter referred to as the average roughness) measured according to ASME B46.12 of the surface of the curable resin layer 12 side of the antibacterial transparent film 10 (the surface of the antibacterial transparent film). “Ra ₂ ”) is preferably less than 0.1 μm, more preferably 0.05 μm or less, and particularly preferably less than 0.03 μm.
Moreover, in the other aspect of this invention, the arithmetic mean roughness (henceforth, following) measured based on JISB0601-1994 of the surface (surface of an antimicrobial transparent film) of the curable resin layer 12 side of the antimicrobial transparent film 10 side. “Ra ₃ ”) may be less than 0.1 μm.

<Measurement of Ra>
The arithmetic average roughness (Ra ₁ to Ra ₃ ) of the surface of the antibacterial transparent film on the curable resin layer side can be measured by the following measurement method.
<Measurement method of Ra ₁ >
Curing type of antibacterial transparent film in accordance with JIS B0601-1982 using a universal surface shape measuring instrument (manufactured by Kosaka Laboratory Co., Ltd., “MODEL SE-3C”) having an apex angle of 90 ° and a radius of 2 μm. The Ra ₁ on the surface on the resin layer side can be measured.
<Measurement method of Ra ₂ >
Using a scanning probe microscope having a radius of curvature of 8 nm, a spring constant of 42 N / m, a resonance frequency of 320 KHz, and a material of single crystal Si based on ASME B46.12, the measurement area is 10 μm × 10 μm. It is possible to calculate the Ra _{2 of} the film surface obtained by performing capture and processing the obtained image. As the probe, it is preferable to use a Si single crystal probe.
The image processing may be realized by image processing means connected to the scanning probe microscope. The image processing means may include a memory and a central processing unit (CPU).
Specifically, using a scanning probe microscope (Neoscope IV and Nanoscope IIIa manufactured by Veeco), an Si single crystal probe is used as a probe, a measurement mode is set to Taping mode, and an image is captured with a measurement area of 10 μm × 10 μm. . After the obtained image is subjected to Flatten processing (0th order) and Planefit processing (XY) once as image processing for removing swell using the analysis software attached to the scanning probe microscope. It is preferable to calculate the surface roughness.
<Measurement method of Ra ₃ >
An antibacterial transparent film according to JIS B0601-1994 using an ultra-deep shape measuring microscope (manufactured by Keyence Corporation, “VK-8500”) having a light source for measuring laser light (wavelength 685 nm) having a diameter of 0.9 μm. The Ra ₃ on the surface of the curable resin layer side can be measured.

The above-mentioned arithmetic surface roughness of the surface of the antibacterial transparent film 10 on the side of the curable resin layer 12 can be adjusted by, for example, the average particle diameter or the added amount of the antibacterial agent contained in the curable resin layer 12. Specifically, the above-mentioned arithmetic surface roughness (Ra ₁ , Ra ₂ or Ra ₃ ) tends to increase as the average particle size of the antibacterial agent increases and as the amount of the antibacterial agent added increases. Ra _{1 to} Ra ₃ tend to be smaller as the average particle size of is smaller and the addition amount of the antibacterial agent is smaller.

  Moreover, it is preferable that the haze value measured based on JISK7136 of the antibacterial transparent film 10 is 2% or less, and it is preferable that a total light transmittance is 90% or more. Moreover, it is preferable that the said haze value is 0.1 to 2%, and it is more preferable that it is 0.3 to 1.5%. Moreover, it is preferable that the said total light transmittance is 90 to 97%, and it is more preferable that it is 91 to 95%. If the haze value and total light transmittance of the antibacterial transparent film are within the above ranges, the antibacterial transparent film 10 can be suitably used as an optical application.

The haze value is a value measured based on JIS K7136, and the total light transmittance is a value measured based on JIS K7361. This means the percentage of the transmitted light that passes through the test piece using the CIE standard light D65 as the light source and is deflected by 0.044 rad (2.5 degrees) or more from the incident light due to scattering.
The haze value and the total light transmittance of the antibacterial transparent film 10 are the types of resins constituting the plastic substrate 11, the types of binder resins constituting the curable resin layer 12, and the Ra of the surface of the antibacterial transparent film 10. Can be adjusted by.

<Method for producing antibacterial transparent film>
The antibacterial transparent film 10 can be manufactured, for example, as follows.
First, an antibacterial agent, a binder resin, and other components as necessary are mixed to prepare a curable resin layer forming composition. As described above, when the curable resin layer 12 is a hard coat layer, the curable resin layer forming composition is a hard coat layer forming composition. When the curable resin layer 12 is an antireflection layer, the curable resin layer 12 is a curable type. The resin layer forming composition is an antireflection layer forming composition.
Next, the antibacterial transparent film 10 in which the curable resin layer 12 is formed on the plastic substrate 11 is obtained by applying the curable resin layer forming composition to the plastic substrate 11 and drying and curing the coating film. can get.

Examples of the coating method of the curable resin layer forming composition include a blade coater, an air knife coater, a roll coater, a bar coater, a gravure coater, a micro gravure coater, a rod blade coater, a lip coater, a die coater, a curtain coater, and printing. The method using a machine etc. is mentioned.
The coating amount of the curable resin layer forming composition is set according to the thickness of the curable resin layer 12 to be formed.

When the binder resin is an active energy ray curable resin, the coating can be cured by irradiation with an active energy ray. When the binder resin is a thermosetting resin, a heating furnace or an infrared lamp is used. It can be cured by heating.
Examples of the active energy rays include ionizing radiation such as ultraviolet rays, electron beams, visible rays, and γ rays. Among them, ultraviolet rays are preferable from the viewpoint of versatility. As the ultraviolet light source, for example, a high pressure mercury lamp, a low pressure mercury lamp, an ultrahigh pressure mercury lamp, a metal halide lamp, a carbon arc, a xenon arc, an electrodeless ultraviolet lamp, or the like can be used.
As the electron beam, for example, an electron beam emitted from various electron beam accelerators such as a cockloftwald type, a bandecraft type, a resonant transformation type, an insulating core transformer type, a linear type, a dynamitron type, and a high frequency type can be used.
Curing by irradiation with active energy rays is preferably performed in the presence of an inert gas such as nitrogen. Moreover, 50-2000 mJ / cm < ² > is preferable and, as for the irradiation amount of the said active energy ray, 100-1000 mJ / cm < ² > is more preferable.
Curing may be performed in one stage, or may be performed in two stages, a preliminary curing process and a main curing process.

<Effect>
The antibacterial transparent film 10 of the present embodiment described above is provided with a curable resin layer 12 containing an antibacterial agent on the outermost layer. In addition, the antibacterial transparent film 10 of the present invention is specifically the aforementioned arithmetic average of the surface of the curable resin layer by reducing both the Ra on the surface of the curable resin layer and the average particle diameter of the antibacterial agent. By containing an antibacterial agent having a roughness (Ra ₁ , Ra ₂ , or Ra ₃ ) of less than 0.1 μm and an average particle diameter of 0.5 to 100 nm, the antibacterial agent has high transparency. A sufficient antibacterial effect can be exhibited without being embedded in the curable resin layer.
Therefore, the antibacterial transparent film 10 of the present invention can sufficiently exhibit the antibacterial effect and is excellent in transparency.

  In particular, by using an antibacterial metal component supported as an antibacterial agent, an excellent antibacterial effect can be expressed by including a small amount, for example, 0.05 to 20% by mass in the curable resin layer. It is preferable because the transparency of the antibacterial transparent film 10 does not decrease and the curable resin layer 12 is hardly yellowed.

<Application>
The antibacterial transparent film 10 can be used as, for example, a hard coat film when the curable resin layer 12 is a hard coat layer, and used as an antireflection film when the curable resin layer 12 is an antireflection layer. Can do.

<Another embodiment>
The antibacterial transparent film of the present invention is not limited to that shown in FIG. For example, as shown in FIG. 2, another layer 13 may be laminated on the curable resin layer 12. Here, the other layer 13 is a layer whose whole or a part is removed or can be removed by a process such as abrasion during use of the antibacterial transparent film 10 or subsequent etching. By removing all or a part of the other layer 13 during or before use of the antibacterial transparent film 10, the curable resin layer 12 is exposed and an antibacterial effect can be exhibited. However, in order to obtain an antibacterial effect from the start of use of the antibacterial transparent film 10, the curable resin layer is preferably provided on the outermost layer as shown in FIG.
When the other layer 13 is laminated on the curable resin layer 12, the material for forming the other layer 13 is not particularly limited as long as the material has the effect of the present invention. For example, the above-described binder resin or etching solution is used for the etching process. Metal materials such as copper that can be used. Further, the other layer 13 does not need to contain an antibacterial agent.
The thickness of the other layer 13 is not particularly limited as long as it has the effect of the present invention, but is preferably 0.1 to 30 μm, and more preferably 0.3 to 3 μm.

  In addition, as shown in FIG. 3, the antibacterial transparent film 10 may be provided with an easy adhesion layer 14 between the plastic substrate 11 and the curable resin layer 12.

Further, the curable resin layer 12 of the antibacterial transparent film 10 shown in FIG. 1 is composed of one layer. For example, like the antibacterial transparent film 10 shown in FIG. You may be comprised, and you may be comprised by 3 or more layers.
In addition, as for the curable resin layer 12 of the antibacterial transparent film 10 shown in FIG. 4, the lower layer (layer which contacts the plastic base material 11) is the hard-coat layer 12a, and the upper layer (layer located in the outermost layer) is an antireflection layer. 12b.

  In the case where the curable resin layer 12 is composed of two or more layers, an antibacterial agent is included in at least the layer located on the outermost layer. When the curable resin layer 12 is composed of two or more layers, the total content of the antibacterial agents in each layer is 100% by mass of the total content of all solid components forming each layer. Sometimes (that is, in a total of 100% by mass of the solid content of the composition for forming a curable resin layer constituting each layer), preferably 0.05 to 20% by mass, and more preferably 0.1 to 10% by mass. It is more preferable that the content is 0.2 to 5% by mass. If the content of the antibacterial agent is 0.05% by mass or more, a sufficient antibacterial effect can be obtained. On the other hand, when the content of the antibacterial agent exceeds 20% by mass, the transparency of the obtained antibacterial transparent film tends to decrease, or the curable resin layer 12 tends to yellow. When the resin layer 12 contains a reactive fluorine agent, the total content of antibacterial agents in each layer is 100% by mass of the total content of all solid components forming each layer (however, the reactive fluorine agent is 0%). 0.1% by mass) is preferably 0.4% by mass or more.

When the curable resin layer 12 is composed of two or more layers, each layer may be a layer formed of the same type of curable resin layer forming composition, or for different types of curable resin layer forming. Although it may be a layer formed from the composition, the curable resin layer 12 preferably includes at least a hard coat layer. If the curable resin layer 12 includes at least a hard coat layer, the antibacterial transparent film 10 can be used as a hard coat film.
For example, as shown in FIG. 4, if the curable resin layer 12 is composed of a hard coat layer 12a and an antireflection layer 12b, an antibacterial transparent material having both functions of a hard coat film and an antireflection film. Film 10 is obtained. In addition, when the curable resin layer 12 includes the hard coat layer 12a and the antireflection layer 12b, the antireflection layer 12b is preferably on the outermost layer side. That is, when the curable resin layer 12 includes the hard coat layer 12a and the antireflection layer 12b, the antireflection layer 12b is preferably laminated on the hard coat layer 12a.

  Moreover, although the curable resin layer 12 is formed in the single side | surface of the plastic base material 11, the antibacterial transparent film 10 shown in FIGS. 1-4 is hardened on both surfaces of the plastic base material 11, for example, as shown in FIG. A mold resin layer 12 may be formed.

[Antimicrobial adhesive sheet]
FIG. 6 is a cross-sectional view showing a configuration of an antibacterial pressure-sensitive adhesive sheet which is an embodiment of the present invention.
In the antibacterial adhesive sheet 20 of this example, an adhesive layer 21 and a release sheet 22 are provided in this order on the surface of the antibacterial transparent film 10 shown in FIG. That is, in one aspect of the present invention, the antibacterial adhesive sheet includes a plastic substrate, a curable resin layer, an adhesive layer, and a release sheet, and the adhesive layer is laminated on the release sheet. The plastic substrate is laminated on the adhesive layer, the curable resin layer is laminated on the plastic substrate, the curable resin layer contains an antibacterial agent, and the antibacterial agent is 0.5. It has an average particle diameter of ˜100 nm, and the arithmetic average roughness (Ra ₁ , Ra ₂ , or Ra ₃ ) on the surface of the curable resin layer is less than 0.1 μm.

<Adhesive layer>
The adhesive layer 21 is a layer for sticking the antibacterial transparent film 10 to an adherend.
As an adhesive which comprises the adhesion layer 21, a natural rubber adhesive, a synthetic rubber adhesive, an acrylic adhesive, a urethane adhesive, a silicone adhesive, etc. are used, for example. Moreover, any of solvent system, emulsion system, and water system may be sufficient. Among these, acrylic solvent-based pressure-sensitive adhesives are particularly preferable from the viewpoints of transparency, weather resistance, durability, cost and the like when used for optical system applications.
Other auxiliary agents may be added to the adhesive as necessary. Other auxiliary agents include thickeners, pH adjusters, tackifiers, binders, crosslinking agents, adhesive fine particles, antifoaming agents, antiseptic / antifungal agents, pigments, inorganic fillers, stabilizers, wetting agents, wetting agents. Etc.
The thickness of the adhesion layer 21 can be adjusted in the range of 3-500 micrometers. Here, the thickness of the adhesive layer 21 means the thickness from the interface between the release sheet 22 and the adhesive layer 21 to the interface between the adhesive layer 21 and the plastic substrate 11. The thickness of the pressure-sensitive adhesive layer 21 is preferably adjusted in the range of 3 to 500 μm according to the mode of the antibacterial transparent sheet 21. The thickness is more preferably 4 to 300 μm, and further preferably 5 to 150 μm. If the thickness of the pressure-sensitive adhesive layer 21 is less than 3 μm, it is difficult to control the film thickness, and unevenness tends to occur. On the other hand, when the thickness of the pressure-sensitive adhesive layer 21 exceeds 500 μm, problems may occur in the manufacturing process such as drying and curing. In addition, problems such as paste sticking out may occur in post-processing such as punching.

<Peeling sheet>
Examples of the release sheet 22 include a release sheet base material and a release agent layer provided on the pressure-sensitive adhesive layer 21 side of the release sheet base material.
Examples of the release sheet substrate include paper such as high-quality paper and glassine paper, and plastic films such as polyethylene terephthalate film and polypropylene film.
As the release agent constituting the release agent layer, for example, a general-purpose addition type or condensation type silicone release agent or a long-chain alkyl group-containing compound is used. In particular, an addition type silicone release agent having high reactivity is preferably used.
The thickness of the release sheet 22 is preferably 20 to 100 μm.

<Method for producing antibacterial adhesive sheet>
The antibacterial pressure-sensitive adhesive sheet 20 is formed, for example, by applying a pressure-sensitive adhesive to the surface of the antibacterial transparent film 10 on the side of the plastic substrate 11 (hereinafter, this surface is also referred to as “back surface of the antibacterial transparent film”). 21 is formed, and a release sheet 22 is stuck on the adhesive layer 21. Alternatively, the adhesive layer 21 is formed by applying an adhesive on the release sheet 22, and the antibacterial adhesive sheet 20 is obtained by pasting the adhesive layer 21 and the back surface of the antibacterial transparent film 10. May be.
Examples of the coating method of the pressure-sensitive adhesive include the various coating methods exemplified above in the description of the method for producing an antibacterial transparent film.

<How to use>
When using the antibacterial transparent film 10, the release sheet 22 of the antibacterial pressure-sensitive adhesive sheet 20 is peeled to expose the pressure-sensitive adhesive layer 21, and the pressure-sensitive adhesive layer 21 is attached to an adherend (for example, the surface of a display or a touch panel). To do.

<Effect>
Since the antibacterial pressure-sensitive adhesive sheet 20 of the present embodiment described above is provided with the pressure-sensitive adhesive layer 21 on the surface of the antibacterial transparent film 10 of the present invention on the plastic substrate 11 side, the antibacterial transparent film 10 of the present invention. Can be attached to the adherend.
In addition, since the antibacterial pressure-sensitive adhesive sheet 20 shown in FIG. 6 is provided with the release sheet 22 on the pressure-sensitive adhesive layer 21, the antibacterial transparent film 10 is stored and transported by being wound in a roll before use. It is possible.

  The antibacterial transparent film and the antibacterial pressure-sensitive adhesive sheet of the present invention have antibacterial activity against at least Escherichia coli and Staphylococcus aurous strains specified in Table 1 of JIS Z2801. Here, “antibacterial activity” means that the antibacterial activity value measured based on JIS Z2801 is 2.0 or more. That is, the antibacterial activity value defined as the logarithmic value of the number of bacteria after 24-hour culture of the unprocessed product divided by the number of bacteria after 24-hour culture of the antibacterial product is 2 for any of the aforementioned bacteria. 0.0 or higher (99% or higher death rate).

<Another embodiment>
The antimicrobial pressure-sensitive adhesive sheet of the present invention is not limited to that shown in FIG. For example, as shown in FIG. 7, an easy adhesion layer 23 may be provided between the plastic substrate 11 and the adhesive layer 21.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited by the following description.

[Production Example 1: Production of antibacterial agent A]
1 part by mass of silica A (trade name: AEROSIL 300, EVONIK, average particle diameter: 7 nm) was dispersed in 90 parts by mass of water to obtain an aqueous dispersion of silica. A 2% by mass aqueous sodium hydroxide solution was added thereto to adjust the pH to 10.
Separately, water glass diluted to 0.1% by mass, a 0.7% by mass sodium aluminate aqueous solution, and a 0.05% by mass silver nitrate aqueous solution were prepared.
After adding 13 parts by mass of the water glass prepared previously and 1.5 parts by mass of the sodium aluminate aqueous solution to 85.5 parts by mass of the silica aqueous dispersion whose pH is adjusted to 10, the alkali removal treatment is performed. Thus, a silica alumina suspension was obtained. 30 parts by mass of the previously prepared silver nitrate aqueous solution was added to 100 parts by mass of the obtained silica-alumina suspension to obtain an antibacterial agent A in which silver was supported on silica.
It was 10 nm when the average particle diameter of the obtained antibacterial agent A was measured as follows.

<Measurement of average particle size of antibacterial agent>
Using a transmission electron microscope, the maximum length of the antibacterial agent particle image (Dmax: maximum length at two points on the contour of the particle image) and the maximum length vertical length (DV-max: two parallel to the maximum length) (The shortest length between the two straight lines when the particle image is sandwiched between these straight lines) was measured, and the geometric mean value (Dmax × DV-max) ^1/2 was taken as the particle diameter. With this method, the particle diameter was measured for 100 antibacterial agents, and the arithmetic average value was defined as the average particle diameter.

[Production Example 2: Production of antibacterial agent B]
An antibacterial agent B in which silver is supported on silica is prepared in the same manner as in Production Example 1 except that 1 part by mass of silica B (trade name: AEROSIL MOX80, manufactured by EVONIK, average particle size: 40 nm) is used instead of silica A. Obtained.
It was 50 nm when the average particle diameter of the obtained antibacterial agent B was measured.

[Production Example 3: Production of antibacterial agent C]
Antibacterial in which silver is supported on silica in the same manner as in Production Example 1 except that 1 part by mass of silica C (trade name: SIRPMA 70WT% -H01, manufactured by CIK Nanotech Co., Ltd., average particle diameter: 700 nm) is used instead of silica A Agent C was obtained.
It was 800 nm when the average particle diameter of the obtained antibacterial agent C was measured.

[Example 1]
<Preparation of composition for forming hard coat layer>
As polyfunctional (meth) acrylic monomer, 6 functional acrylate (trade name DPHA, manufactured by Daicel-Cytec) 63.6 parts by mass, diethylene glycol diacrylate (trade name SR230, manufactured by Sartomer) 27 parts by mass, photopolymerization initiator (commodity) Name IRGACURE184, manufactured by BASF) 5 parts by mass, light stabilizer (trade name TINUVIN152, manufactured by BASF) 4 parts by mass, and antibacterial agent A (average particle size 10 nm) 0.4 parts by mass, methyl ethyl ketone (MEK) and A hard coat layer-forming composition (A) was prepared by mixing in a diluent solvent in which cyclohexanone was mixed 1: 1 so that the solid content was 40% by mass.

<Manufacture of antibacterial transparent film>
As a plastic substrate, a PET film (trade name: A4300, manufactured by Toyobo Co., Ltd.) having a thickness of 75 μm was used, and the hard coat layer forming composition (A) was bar-coated on the plastic substrate. Thereafter, it is heated and dried at 80 ° C. for 60 seconds, and using a high-pressure mercury lamp ultraviolet ray irradiator (made by Eye Graphics Co., Ltd.) under a nitrogen atmosphere under the conditions of 160 W / cm, lamp height of 13 cm, belt speed of 10 m / min, and 2 pass. Was irradiated with ultraviolet rays, and a hard coat layer having a thickness of 4 μm was cured and formed on a plastic substrate as a curable resin layer to obtain an antibacterial transparent film.

[Example 2]
A hard coat layer forming composition (B) was prepared in the same manner as in Example 1 except that the antibacterial agent B (average particle size 50 nm) was used instead of the antibacterial agent A.
An antibacterial transparent film was obtained in the same manner as in Example 1 except that the obtained composition for forming a hard coat layer (B) was used.

[Example 3]
Example 1 except that the amount of hexafunctional acrylate was changed from 63.6 parts by mass to 63.2 parts by mass, and the amount of antibacterial agent A was changed from 0.4 parts by mass to 0.8 parts by mass. Similarly, a composition (C) for forming a hard coat layer was prepared.
An antibacterial transparent film was obtained in the same manner as in Example 1 except that the obtained composition for forming a hard coat layer (C) was used.

[Example 4]
An antibacterial transparent film was obtained in the same manner as in Example 1 except that the hard coat layer-forming composition (A) was applied to a plastic substrate so that the thickness of the hard coat layer after curing was 10 μm.

[Example 5]
<Preparation of composition for forming antireflection layer>
As a polyfunctional (meth) acrylic monomer, 45.6 parts by mass of hexafunctional acrylate (trade name DPHA, manufactured by Daicel-Cytec), 5 parts by mass of diethylene glycol diacrylate (trade name: SR230, manufactured by Sartomer), silicone compound (trade name: Sila) Plain FM-0711 (manufactured by Chisso Corporation) 3 parts by mass, hollow silica sol (manufactured by JGC Catalysts & Chemicals Co., Ltd.) 38 parts by mass, photopolymerization initiator (trade name IRGACURE184, manufactured by BASF) 4 parts by mass, light stability Dilution of 1: 1 mixing of methyl isobutyl ketone (MIBK) and n-butanol with 4 parts by mass of an agent (trade name TINUVIN 152, manufactured by BASF) and 0.4 parts by mass of antibacterial agent A (average particle size 10 nm) An anti-reflective layer-forming composition (D) mixed with a solvent so that the solid content is 10% by mass It was prepared.

<Manufacture of antibacterial transparent film>
In the same manner as in Example 1, the hard coat layer-forming composition (A) was applied to a plastic substrate by bar coating, and the coating film was dried and cured to form a hard coat layer having a thickness of 4 μm on the plastic substrate. .
Subsequently, the antireflection layer-forming composition (D) was bar-coated on the hard coat layer. Thereafter, it is heated and dried at 80 ° C. for 60 seconds, and using a high-pressure mercury lamp ultraviolet ray irradiator (made by Eye Graphics Co., Ltd.) under a nitrogen atmosphere under the conditions of 160 W / cm, lamp height of 13 cm, belt speed of 10 m / min, and 2 pass. The antireflection layer having a thickness of 100 nm was cured and formed on the hard coat layer to obtain an antibacterial transparent film. In addition, the curable resin layer of the obtained antibacterial transparent film has a two-layer structure including a hard coat layer having a thickness of 4 μm and an antireflection layer having a thickness of 100 nm.

[Example 6]
The amount of hexafunctional acrylate was changed from 63.6 parts by mass to 63.4 parts by mass, the amount of antibacterial agent A was changed from 0.4 parts by mass to 0.5 parts by mass, and a reactive fluorine agent ( A composition (E) for forming a hard coat layer was prepared in the same manner as in Example 1 except that 0.1 part by mass (trade name Megafac RS-75, manufactured by DIC Corporation) was used.
An antibacterial transparent film was obtained in the same manner as in Example 1 except that the obtained hard coat layer forming composition (E) was used.

[Comparative Example 1]
A hard coat layer forming composition (F) was prepared in the same manner as in Example 1 except that the antibacterial agent C (average particle size 800 nm) was used instead of the antibacterial agent A.
An antibacterial transparent film was obtained in the same manner as in Example 1 except that the obtained composition for forming a hard coat layer (F) was used.

[Comparative Example 2]
<Preparation of composition for forming hard coat layer>
6-functional acrylate (trade name DPHA, manufactured by Daicel Cytec Co., Ltd.) 53.6 parts by mass as a polyfunctional (meth) acrylic monomer, 27 parts by mass of diethylene glycol diacrylate (trade name SR230, manufactured by Sartomer), photopolymerization initiator (product) Name IRGACURE184, manufactured by BASF) 5 parts by mass, light stabilizer (trade name TINUVIN152, manufactured by BASF) 4 parts by mass, silica (trade name AZ-204, manufactured by Tosoh Silica) 10 parts by mass, and antibacterial agent A0 A hard coat layer forming composition (G) was prepared by mixing 4 parts by mass with a dilution solvent in which methyl ethyl ketone (MEK) and cyclohexanone were mixed at a ratio of 1: 1 so that the solid content was 40% by mass.

<Manufacture of antibacterial transparent film>
A composition for forming a hard coat layer (G) on a plastic substrate in the same manner as in Example 1, except that the composition for forming a hard coat layer (G) was used instead of the composition for forming a hard coat layer (A). ), And the coating film was dried and cured to form a 4 μm thick hard coat layer on the plastic substrate.
Subsequently, the antireflection layer-forming composition (D) was bar-coated on the hard coat layer. Thereafter, it is heated and dried at 80 ° C. for 60 seconds, and using a high-pressure mercury lamp ultraviolet ray irradiator (made by Eye Graphics Co., Ltd.) under a nitrogen atmosphere under the conditions of 160 W / cm, lamp height of 13 cm, belt speed of 10 m / min, and 2 pass. The antireflection layer having a thickness of 100 nm was cured and formed on the hard coat layer to obtain an antibacterial transparent film. In addition, the curable resin layer of the obtained antibacterial transparent film has a two-layer structure including a hard coat layer having a thickness of 4 μm and an antireflection layer having a thickness of 100 nm.

[Measurement and evaluation method]
For the antibacterial transparent film obtained in each example, Ra of the surface of the antibacterial transparent film, the haze value and the total light transmittance of the antibacterial transparent film are measured by the following methods, and the pencil hardness and light resistance are measured. The antibacterial activity was evaluated. The results are shown in Table 1.
Table 1 shows the average particle diameter and content of the antibacterial agent in the curable resin layer of each example, the content of the reactive fluorine agent, and the thickness of the curable resin layer. In addition, content of the antibacterial agent shown in Table 1 is the quantity in 100 mass% of solid content of the composition for hard-coat layer formation or the composition for antireflection layer formation. For Example 5 and Comparative Example 2, the total content of antibacterial agents contained in the hard coat layer and the antireflection layer is shown in Table 1.

<Measurement of Ra>
Ra ₁ to Ra ₃ on the surface of the curable resin layer side of the antibacterial transparent film were measured. The results are shown in Table 1.
<Measurement method of Ra ₁ >
Curing type of antibacterial transparent film in accordance with JIS B0601-1982 using a universal surface shape measuring instrument (manufactured by Kosaka Laboratory Co., Ltd., “MODEL SE-3C”) having an apex angle of 90 ° and a radius of 2 μm. The Ra ₁ on the surface on the resin layer side can be measured.
<Measurement method of Ra ₂ >
Using a scanning probe microscope having a radius of curvature of 8 nm, a spring constant of 42 N / m, a resonance frequency of 320 KHz, and a material of single crystal Si based on ASME B46.12, the measurement area is 10 μm × 10 μm. It is possible to calculate the Ra _{2 of} the film surface obtained by performing capture and processing the obtained image. As the probe, it is preferable to use a Si single crystal probe.
The image processing may be realized by image processing means connected to the scanning probe microscope. The addition processing means may include a memory and a central processing unit (CPU).
Specifically, using a scanning probe microscope (Neoscope IV and Nanoscope IIIa manufactured by Veeco), an Si single crystal probe is used as a probe, a measurement mode is set to Taping mode, and an image is captured with a measurement area of 10 μm × 10 μm. . After the obtained image is subjected to Flatten processing (0th order) and Planefit processing (XY) once as image processing for removing swell using the analysis software attached to the scanning probe microscope. It is preferable to calculate the surface roughness.
<Measurement method of Ra ₃ >
An antibacterial transparent film according to JIS B0601-1994 using an ultra-deep shape measuring microscope (manufactured by Keyence Corporation, “VK-8500”) having a light source for measuring laser light (wavelength 685 nm) having a diameter of 0.9 μm. The Ra ₃ on the surface of the curable resin layer side can be measured.

<Measurement of haze value>
The haze value of the antibacterial transparent film was measured using NDH5000 manufactured by Nippon Denshoku Co., Ltd. based on JIS K7136.

<Measurement of total light transmittance>
The total light transmittance of the antibacterial transparent film was measured using NDH5000 manufactured by Nippon Denshoku Co., Ltd. based on JIS K7361.

<Evaluation of pencil hardness>
The plastic substrate side of the antibacterial transparent film was fixed on a 2 mm-thick glass plate with a cellophane tape, and based on JIS K5400-1990, the surface of the curable resin layer side was scratched with a pencil. Determination was evaluated by cracking of the curable resin layer.

<Evaluation of light resistance>
Using a xenon weather meter manufactured by Suga Test Instruments, using a xenon lamp as a light source, light of a wavelength of 275 nm or more is set to an irradiation amount of 60 W / m ^{2 in} a wavelength range of 300 to 400 nm, and a curable resin for an antibacterial transparent film An accelerated exposure test was conducted by irradiating from the layer side for 24 hours.
The hue of the antibacterial transparent film before and after the accelerated exposure test was measured, ΔE was obtained from the following formula, and the hue change was evaluated.
ΔE = {(L ^* _b− L ^* _a ) ² + (a ^* _b− a ^* _a ) ² + (b ^* _b− b ^* _a ) ² } ^1/2
In the formula, L ^* _b , a ^* _b and b ^* _b indicate the hue (L ^* , a ^* , b ^* ) of the antibacterial transparent film before the accelerated exposure test, and L ^* _a , a ^* _a , b ^* _a hue of antibacterial transparent film after accelerated exposure test ^{(L *, a *, b} *) shows a.

<Evaluation of antibacterial activity>
Based on JIS Z2801, antibacterial activity values of Staphylococcus aureus and Escherichia coli were measured.

As can be seen from Table 1, the average particle diameter of the antibacterial agent is 0.5 to 100 nm, and the Ra on the surface of the curable resin layer side is less than 0.1 μm. The antibacterial transparent film exhibited a sufficient antibacterial effect, was excellent in transparency, and had light resistance. Moreover, the antibacterial transparent film obtained in each example had sufficient pencil hardness, and was suitable as a hard coat film.
On the other hand, the antibacterial transparent film obtained in Comparative Example 1 in which the average particle diameter of the antibacterial agent is 800 nm cannot sufficiently exhibit the antibacterial effect.
The antibacterial transparent film obtained in Comparative Example 2 in which Ra on the surface of the curable resin layer side was 0.3 to 0.5 μm was inferior in transparency.

DESCRIPTION OF SYMBOLS 10 Antibacterial transparent film 11 Plastic base material 12 Curable resin layer 12a Hard coat layer 12b Antireflection layer 13 Other layers 14 Easy-adhesion layer 20 Antibacterial adhesive sheet 21 Adhesive layer 22 Release sheet 23 Easy-adhesion layer

Claims (6)

  An antibacterial transparent film comprising a plastic substrate and a curable resin layer laminated on at least one surface of the plastic substrate, wherein the curable resin layer contains an antibacterial agent, An antibacterial transparent film having an average particle diameter of 0.5 to 100 nm and having an arithmetic average roughness (Ra) of less than 0.1 μm measured on the surface of the curable resin layer according to JIS B0601-1982.   The antibacterial transparent film according to claim 1, wherein the antibacterial agent is an inorganic oxide carrying an antibacterial metal component.   The antibacterial transparent film according to claim 1 or 2, wherein the curable resin layer is provided on the outermost layer of the antibacterial transparent film.   The antibacterial transparent film according to any one of claims 1 to 3, wherein the curable resin layer includes a hard coat layer.   The haze value measured based on JIS K7136 of the antibacterial transparent film is 2% or less, and the total light transmittance measured based on JIS K7361 is 90% or more. The antibacterial transparent film according to claim 1.   An antibacterial pressure-sensitive adhesive sheet comprising the antibacterial transparent film according to any one of claims 1 to 5 and an adhesive layer, wherein a plastic substrate of the antibacterial transparent film is laminated on the adhesive layer. .

Images