TWI555638B - Antibacterial transparent film and antibacterial adhesive sheet - Google Patents

Description

Antibacterial transparent film, and antibacterial adhesive sheet

The present invention relates to an antibacterial transparent film and an antibacterial adhesive sheet.

The present invention claims priority based on Japanese Patent Application No. 2012-177395, filed on Jan.

There is a case where a hard coat film having a hard coat layer is attached to the surface of a display or a touch panel or the like in order to increase the surface hardness.

In recent years, the number of products related to daily life has been increasing, and those who have been given antibacterial properties have also been proposed to have antibacterial properties.

As a hard coat film having an antibacterial property, for example, Patent Document 1 discloses a hard coat film having 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 above hardening The surface of the resin layer side has an arithmetic mean roughness (Ra) of 0.1 to 3.0 μm. According to Patent Document 1, it is possible to prevent the above-mentioned antibacterial agent from being completely embedded in the curable resin layer by using Ra to be 0.1 μm or more and using an antibacterial agent having an average particle diameter of 0.1 μm or more. Antibacterial effect.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 3577145

Further, the hard coat film is attached to the surface of a display or a touch panel as described above, and therefore, the hardness is required to have excellent transparency.

However, the hard coat film described in Patent Document 1 cannot obtain sufficient transparency.

As a method of improving transparency, for example, it is considered to reduce the value of Ra of the film surface. However, in the case of the hard coat film described in Patent Document 1, when the value of Ra is less than 0.1 μm, the antibacterial agent is completely embedded in the curable resin layer, and the antibacterial effect cannot be exhibited. Thus, it is difficult to have both antibacterial property and transparency.

An object of the present invention is to provide an antibacterial transparent film which can exhibit an excellent antibacterial effect and which has excellent transparency, and an antibacterial adhesive sheet comprising the above antibacterial transparent film.

The present invention has the following aspects.

[1] An antibacterial transparent film comprising a plastic substrate and a curable resin layer comprising an antibacterial agent disposed on the plastic substrate, wherein the antibacterial agent has an average particle diameter of 0.5 to 100 nm and is based on JIS B0601 The arithmetic mean roughness (Ra) of the surface of the hardened resin layer side measured was less than 0.1 μm.

[2] The antibacterial transparent film according to the above [1], wherein the antibacterial agent is one in which an inorganic oxide carries an antibacterial metal component.

[3] The antibacterial transparent film according to the above [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 hardening type resin layer comprises a hard coat layer.

[5] The antibacterial transparent film according to any one 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%. the above.

[6] An antibacterial adhesive sheet provided with an adhesive layer on the surface of the plastic substrate side of the antibacterial transparent film according to any one of the above [1] to [5].

That is, the present invention has the following aspects.

<1> An antibacterial transparent film comprising a plastic substrate and a hardened resin layer laminated on at least one surface of the plastic substrate, wherein the curable resin layer contains an antibacterial agent, and the antibacterial agent has 0.5~ The average particle diameter of 100 nm, the arithmetic mean roughness (Ra) of the surface of the hardened resin layer measured according to JIS B0601-1982 is less than 0.1 μm, and the antibacterial transparent film of <2>, wherein the above antibacterial agent An inorganic transparent film carrying an antibacterial metal component, wherein the antibacterial transparent film of the above-mentioned antibacterial transparent film 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 hardening type resin layer is a hard coat layer, and the antibacterial transparent film according to any one of <1> to <4> The haze value of the antibacterial transparent film measured by JIS K7136 is 2% or less, and the total light transmittance measured by JIS K7361 is 90% or more; <6> an antibacterial adhesive sheet comprising < The antibacterial transparent film and the adhesive layer according to any one of <5>, wherein the plastic substrate of the antibacterial transparent film is laminated on Said adhesive layer.

According to the present invention, it is possible to provide an antibacterial transparent film which can sufficiently exhibit an antibacterial effect and has excellent transparency, and an antibacterial adhesive sheet comprising the above antibacterial transparent film.

10‧‧‧Antibacterial transparent film

11‧‧‧Plastic substrate

12‧‧‧ hardened resin layer

12a‧‧‧hard coating

12b‧‧‧Anti-reflective layer

13‧‧‧Other layers

14‧‧‧Easy layer

20‧‧‧Antibacterial adhesive sheet

21‧‧‧Adhesive layer

22‧‧‧ peeling film

23‧‧‧Easy layer

Fig. 1 is a cross-sectional view showing an example of an antibacterial transparent film.

Fig. 2 is a cross-sectional view showing another example of the antibacterial transparent film.

Fig. 3 is a cross-sectional view showing another example of the antibacterial transparent film.

Fig. 4 is a cross-sectional view showing another example of the antibacterial transparent film.

Fig. 5 is a cross-sectional view showing another example of the antibacterial transparent film.

Fig. 6 is a cross-sectional view showing an example of an antimicrobial adhesive sheet.

Fig. 7 is a cross-sectional view showing another example of the antimicrobial adhesive sheet.

Hereinafter, the present invention will be described in detail.

[Antibacterial transparent film]

Fig. 1 is a cross-sectional view showing the structure of an antibacterial transparent film according to 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 the present embodiment.

<Plastic substrate>

The plastic substrate 11 is not particularly limited as long as it has transparency, and the transparency of the plastic substrate 11 is preferably 85% or more based on the total light transmittance measured in accordance with JIS K7361. That is, in one aspect of the present invention, the transparency of the plastic substrate 11 is preferably a total light transmittance of 85% or more, and the total light transmittance is defined as follows: using a test piece of 3 × 3 cm or more, CIE (International Commission on Illumination) standard light D65 as the light source, the ratio of the total transmitted beam of the test piece concentrated by the integrating sphere relative to the parallel incident beam.

Examples of the plastic substrate 11 include a polyethylene terephthalate (PET) film, a polyethylene naphthalate film, a polytrimethylene terephthalate film, and polybutylene terephthalate. Film, propylene naphthalate film, polyethylene film, polypropylene film, celecoxib, diethyl phthalocyanine film, triethylene fluorene cellulose film, acetonitrile cellulose butyrate film, polyvinyl chloride film , polyvinylidene chloride film, polyvinyl alcohol film, ethylene-vinyl acetate copolymer film, polystyrene Membrane, polycarbonate film, polymethylpentene film, polyfluorene film, polyether ether ketone film, polyether ruthenium film, polyether phthalimide film, polyimine film, fluororesin film, polyamide film An acrylic resin film or the like.

Among them, a PET film is preferred from the viewpoints of transparency, weather resistance, solvent resistance, rigidity, cost, and the like. Further, the rupture strength of the PET film is preferably 150 MPa or more, and the elongation at break is preferably 100% or more. Further, the heat shrinkage rate of the heat treatment at 150 ° C for 30 minutes of the PET film is preferably 1.5% or less. The plastic substrate 11 may also contain various additives. Examples of the additive include an antioxidant, a heat-resistant stabilizer, an ultraviolet absorber, organic particles, inorganic particles, a pigment, a dye, an antistatic agent, a nucleating agent, a coupling agent, and the like.

The plastic substrate 11 may be subjected to a surface treatment in order to improve the adhesion to the curable resin layer 12. Examples of the surface treatment include surface etching treatment such as embossing treatment or solvent treatment, corona discharge treatment, chromic acid treatment, flame treatment, hot air treatment, ozone irradiation treatment, and the like.

The thickness of the plastic substrate 11 is preferably from 10 to 500 μm, more preferably from 20 to 300 μm. When the thickness of the plastic substrate 11 is 10 μm or more, the antibacterial transparent film is less likely to be broken, and when it is 500 μm or less, the transparency can be favorably maintained, and the workability is also excellent.

<hardened resin layer>

The hardened resin layer 12 is a layer containing a binder resin and an antibacterial agent. The above binder resin contains at least a hardening type resin. Here, the "cured resin layer" means a layer obtained by curing a binder resin.

The hardened resin layer 12 is obtained by applying a composition for forming a cured resin layer containing an antibacterial agent and a binder resin to the plastic substrate 11 and drying and curing the coating film. Hereinafter, each component constituting the curable resin layer 12 will be described.

(Antibacterial agents)

The antibacterial agent contained in the curable resin layer 12 has an average particle diameter of 0.5 to 100 nm, preferably 5 to 80 nm, more preferably 8 to 40 nm.

The details of the surface of the antibacterial transparent film 10 on the side of the hardened resin layer 12 (hereinafter, also referred to as the surface of the "antibacterial transparent film") have an arithmetic mean roughness (Ra) of less than 0.1. Mm. The present inventors have found that even if the average particle diameter of the antibacterial agent is 100 nm or less, if the Ra of the surface of the antibacterial transparent film 10 is less than 0.1 μm, the transparency is not impaired, and since the antibacterial agent is not buried in the curable resin layer 12, Therefore, a sufficient antibacterial effect can be exerted, and the antibacterial agent does not fall off from the surface. However, if the average particle diameter of the antibacterial agent is less than 0.5 nm, it is difficult to produce an antibacterial agent. Here, the term "buried with an antibacterial agent" means a state in which the entire antibacterial agent is covered with the binder resin constituting the curable resin layer 12. In other words, when the average particle diameter of the antibacterial agent is 0.5 to 100 nm and the Ra of the surface 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 partially exposed on the surface of the antibacterial transparent film 10. The state has a higher antibacterial effect and is therefore preferred.

In addition, the "sufficient antibacterial effect" means that the antibacterial activity value for Staphylococcus aureus and Escherichia coli based on JIS Z2801 is 2.0 or more. That is, it means that the antibacterial activity value defined as the number of bacteria in the unprocessed product after 24 hours of cultivation divided by the number of bacteria in the antibacterial processed product after 24 hours of cultivation is 2.0 or more for any of the above-mentioned bacteria. (more than 99% death rate).

Further, the inventors of the present application found that if the average particle diameter of the antibacterial agent exceeds 100 nm, it becomes impossible to obtain a sufficient antibacterial effect. When the antibacterial activity of the antibacterial agent is weak, in order to obtain a sufficient antibacterial effect, the content of the antibacterial agent may be increased. However, the details will be described later, and if the content of the antibacterial agent is increased, the transparency of the obtained antibacterial transparent film 10 is lowered, or the hardened resin layer 12 is yellowed. In the present invention, by using an antibacterial agent having an average particle diameter of 0.5 nm to 100 nm, the curable resin layer 12 can exhibit a sufficient antibacterial effect without causing yellowing.

Further, since the Ra of the surface of the antibacterial transparent film 10 is less than 0.1 μm, if the antibacterial When the average particle diameter of the agent exceeds 100 nm, the antibacterial agent easily falls off from the curable resin layer 12.

The average particle diameter of the antibacterial agent is a value measured by the following method.

The maximum length of the particle image of the antimicrobial agent using a transmission electron microscope (Dmax: the maximum length of 2 points on the contour of the particle image) and the maximum length of the vertical length (DV-max: parallel to the maximum length) The length of the shortest length between the two straight lines when the two images are held by the straight line is measured, and the geometric mean value (Dmax × DV - max) ^{1/2 of} the equal value is taken as the particle diameter. The particle diameter of any 100 antibacterial agents was measured by this method, and the arithmetic mean value of these was made into the average particle diameter.

Examples of the antibacterial agent include organic antibacterial agents and inorganic antibacterial agents.

Examples of the organic antibacterial agent include eucalyptus alcohol, a 4-grade ammonium salt, TBZ (2-(4-thiazolyl) benzimidazole), and OPP (o-phenylphenol).

The inorganic antibacterial agent is preferably an inorganic oxide supporting an antibacterial metal component. When the curable resin layer 12 contains an antibacterial metal component as an antibacterial agent, when an inorganic oxide supporting an antibacterial metal component is used as an antibacterial agent, an excellent antibacterial effect can be exhibited in a small amount, and thus it is preferable. .

Examples of the inorganic oxide include a single inorganic oxide such as SiO ₂ , TiO ₂ , ZrO ₂ , Al ₂ O ₃ , Fe ₂ O ₃ , Sb ₂ O ₃ , WO ₃ or CeO ₂ , or 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 -ZrO ₂ , a composite oxide such as SiO ₂ -TiO ₂ -CeO ₂ , one or more of these may be used. Among them, SiO ₂ , TiO ₂ , and Al ₂ O ₃ are preferable, and in particular, in terms of excellent transparency, SiO _{2 is} preferable.

The average particle diameter of the inorganic oxide is preferably from 0.3 to 90 nm, more preferably from 5 to 60 nm, still more preferably from 6 to 30 nm. When the average particle diameter of the inorganic oxide is 0.3 nm or more, the antibacterial agent can exhibit a sufficient antibacterial effect without being buried in the curable resin layer 12. On the other hand, when the average particle diameter of the inorganic oxide is 90 nm or less, it is easy to produce an antibacterial agent having an average particle diameter of 100 nm or less of the antibacterial agent, and therefore it is difficult for the antibacterial agent 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 above-mentioned antibacterial agent.

As the antibacterial metal component, an antibacterial metal component used as an inorganic antibacterial agent can be used, and specific examples thereof include silver, copper, zinc, lead, tin, antimony, cadmium, chromium, mercury, nickel, cobalt, and the like. One or more of these may be used. Among them, in addition to the antibacterial property, silver, copper, and zinc have odor resistance, mold resistance, and algae resistance, and are excellent in handleability. Therefore, it is preferable as an antibacterial metal component. These antibacterial metal components are preferably supported on the inorganic oxide in terms of ease of expression of the antibacterial property.

In the antibacterial agent, the inorganic oxide supporting the antibacterial metal component, the content of the antibacterial metal component, that is, the loading ratio of the antibacterial metal component is preferably 0.001% by mass or more based on the total mass of the antibacterial agent. More preferably, it is 0.001 to 10% by mass, and further 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 of supporting the antibacterial metal component on the inorganic oxide is not particularly limited. For example, the inorganic compound may be attached to the surface of the inorganic oxide to produce a colloidal particle having a negative charge, and the antimicrobial metal component may be attached thereto. The colloidal particles are obtained by the antibacterial agent in which the inorganic oxide carries the antibacterial metal component. In other words, in the aspect of the invention, "the antibacterial metal component is supported on the inorganic oxide" means that the antibacterial metal component is attached to the surface of the inorganic oxide which is colloidally treated in a negatively charged manner. .

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 and SiO ₂ -TiO ₂ . One or more of these may be used. Among them, SiO ₂ -Al ₂ O _{3 is} preferred.

SiO ₂ -Al ₂ O ₃ in particular mass ratio _{(SiO 2 / Al 2 O 3} ) SiO 1/1 ~ 5 / of 1 ₂ -Al ₂ O ₃ is preferred. When the mass ratio is within the above range, the antibacterial metal component can be sufficiently adhered to the colloid-treated inorganic oxide, which is preferable.

The content of the antibacterial metal component is preferably 0.1 to 100 parts by mass, more preferably 1 to 30 parts by mass, per 100 parts by mass of the inorganic oxide. When the content of the antibacterial metal component is 0.1 part by mass or more, sufficient antibacterial activity can be obtained. On the other hand, even if the content of the antibacterial metal component exceeds 100 parts by mass, the antibacterial activity reaches the limit. Therefore, in consideration of the production cost, the content of the antibacterial metal component is preferably 100 parts by mass or less.

Among the inorganic oxides used as the carrier, those having a porous structure (for example, zeolite or the like) containing a large amount of pores (pores) of about 0.1 to 1.0 nm are well known. However, when the antibacterial metal component is supported on such an inorganic oxide having a porous structure, the supported components adhere not only to the surface of the inorganic oxide but also to the inside of the porous material, and as a result, Since the contact ratio between the antibacterial metal component and the fungus is lowered and the antibacterial effect is lowered, a large amount of the antibacterial metal component is required in order to exhibit an antibacterial effect. Further, the zeolite is known to have a problem of discoloration or opacity over time, and is not suitable for use in an antibacterial transparent film. In order to solve this problem, the antibacterial transparent film of the present invention treats the inorganic oxide by selectively adhering the antibacterial metal component to the surface of the inorganic oxide, thereby allowing the supported antimicrobial metal component to be carried. The surface exposure rate is increased, and a sufficient antibacterial effect is obtained with a smaller amount of the antibacterial metal component.

Hereinafter, a case where SiO ₂ -Al ₂ O _{3 is} used as an inorganic compound will be exemplified, and an example of a method for producing an antibacterial agent will be specifically described.

First, particles of an inorganic oxide 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, and is about 1 to 20% by mass based on the total mass of the suspension. Then, an aqueous alkali solution (such as an aqueous sodium hydroxide solution) is added to the suspension so that the pH of the suspension becomes 10 to 11. By adjusting the pH of the suspension to 10 to 11, the surface of the inorganic oxide is partially dissolved and the reactivity with the inorganic oxide is improved. Then, the pH-adjusted suspension is heated to about 60 to 98 ° C as needed.

Then, a specific amount of sodium aluminate aqueous solution and a specific amount of water glass are simultaneously added to the suspension while stirring, and heated and aged at 60 to 98 ° C for 0.5 to 5 hours to adhere the SiO ₂ -Al ₂ O ₃ hydrate. On the surface of inorganic oxides. Thereafter, the alkali is removed by a de-alkali treatment using a cation exchange resin or the like to obtain an inorganic oxide (hereinafter sometimes referred to as "colloidal granular inorganic oxide") which is colloid-treated with a negative charge.

Further, an antibacterial metal component is dissolved in ammonia water to prepare an ammonia such as [Cu(NH ₃ ) ₄ ] ²⁺ , [Ag(NH ₃ ) ₂ ] ⁺ , [Zn(NH ₃ ) ₄ ] ²⁺ , which is an antibacterial metal component. The wrong salt aqueous solution is added to the previously obtained colloidal granular inorganic oxide while stirring, and the antibacterial metal component is adhered to the colloidal granular inorganic oxide to obtain an inorganic oxide-supporting antibacterial metal component. a suspension of the antibacterial agent. Thereafter, a decane coupling agent or the like may be added as needed and heated and aged.

The suspension of the antibacterial agent obtained in this manner or the suspension of the antibacterial agent after heating and aging is spray-dried and calcined to obtain a granular antibacterial agent.

The content of the antibacterial agent in the curable resin layer 12 is preferably 0.05 to 20% by mass, more preferably 0.1 to 10% by mass, even more preferably 0.1 to 10% by mass, based on the total mass of the solid content component of the composition for forming a cured resin layer. It is 0.2 to 5 mass%. When 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 is lowered, or the cured resin layer 12 tends to be yellowish.

In addition, the details will be described later, and 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 contains a reactive fluorochemical agent such as a fluorine-based antifouling agent as another component, the reactive fluorochemical agent may escape to the surface of the curable resin layer 12 over time, and thus The possibility of hindering the action of the antibacterial agent. Therefore, when the curable resin layer 12 contains a reactive fluorinating agent, it is preferred to increase the content of the antibacterial agent. For example, when the composition for forming a cured resin layer contains a reactive fluorinating agent in an amount of 0.1% by mass based on the total mass of the composition for forming a cured resin layer, the antibacterial in the composition for forming a curable resin layer Content of the agent The total mass of the solid content component of the composition for forming a cured resin layer is preferably 0.4% by mass or more. When the content of the antibacterial agent is 0.4% by mass or more, even if the reactive fluorinating agent escapes to the surface of the curable resin layer 12, the antibacterial effect can be sufficiently exhibited. In addition, when the composition for forming a cured resin layer contains 0.1% by mass of a reactive fluorinating agent, the content of the antibacterial agent is preferably 20% by mass or less from the viewpoint of preventing the decrease in the transparency or the yellowing.

(Binder resin)

The binder resin used in the hardened resin layer 12 contains at least a hardening type resin. Examples of the curable resin include a thermosetting resin, an active energy ray curable resin, and the like.

Examples of the thermosetting resin include a phenol resin, a urea resin, a diallyl phthalate resin, a melamine resin, an unsaturated polyester resin, a polyurethane resin, an epoxy resin, and an amine group. Alkyd resin, enamel resin, polyoxyalkylene resin, and the like.

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

The term "polyfunctional" means having two or more polymerizable unsaturated groups in the structure, and the "(meth)acrylic monomer" is a compound having at least a (meth)acryl fluorenyl group as a polymerizable unsaturated group. . The "(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(methyl) Acrylate, propylene oxide modified neopentyl glycol di(meth)acrylate, modified bisphenol A di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, polyethylene a bifunctional (meth) acrylate such as an alcohol (mass average molecular weight of 400) di(meth)acrylate; Pentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolpropane ethoxy tris(meth)acrylate, polyether tri(meth)acrylate, C3 Trifunctional (meth) acrylate such as alcohol propoxy tri(meth) acrylate; pentaerythritol tetra (meth) acrylate, pentaerythritol ethoxy tetra (meth) acrylate, di-trimethylolpropane tetra 4-functional (meth) acrylate such as (meth) acrylate; dipentaerythritol penta (meth) acrylate, propionic acid modified dipentaerythritol penta (meth) acrylate, dipentaerythritol monohydroxy penta (meth) acrylate A 5-functional or higher (meth) acrylate such as an ester or dipentaerythritol hexa(meth)acrylate.

These polyfunctional (meth)acrylic monomers may be used alone or in combination of two or more.

The polyfunctional (meth)acrylic monomer is preferably a tetrafunctional or higher (meth)acrylic monomer (preferably a 5-functional or higher (meth)acrylic monomer) as a main component, and 2 The ~3-functional (meth)acrylic monomer is a subcomponent. In other words, the ratio of the tetra- or higher-functional (meth)acrylic monomer is preferably 50% by mass or more and less than 95% by mass, more preferably 60%, based on the total mass of the polyfunctional (meth)acrylic monomer. More than % by mass and less than 90% by mass. Further, the ratio of the 2-3-functional (meth)acrylic monomer is preferably 5% by mass or more and less than 50% by mass, more preferably 10% by mass based on the total mass of the polyfunctional (meth)acrylic monomer. More than % and less than 40% by mass.

Among these, a tetrafunctional or higher (meth)acrylic monomer contributes to an increase in the hardness of the cured resin layer, and a 2-3 functional (meth)acrylic monomer contributes to an improvement in the softness of the cured resin layer. . Therefore, the above-mentioned tetrafunctional or higher (meth)acrylic monomer having a total mass of 50% by mass or more and less than 95% by mass based on the total mass of the polyfunctional (meth)acrylic monomer is contained, and When the bis(3-)-functional (meth)acrylic monomer is 5% by mass or more and less than 50% by mass based on the total mass of the polyfunctional (meth)acrylic monomer, the hardened type obtained is obtained. The resin layer 12 has high hardness and moderate flexibility, and is excellent in scratch resistance. The details will be described below, and the hardened tree can be used. The lipid layer 12 is made of a hard coat layer.

In the viewpoint of the transparency and the 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 from 30 to 98% by mass, and more preferably from 50 to 95% by mass, based on the total mass of the solid content component of the composition for forming a curable resin layer. When the content of the curable resin is 30% by mass or more, when the curable resin layer 12 is made into a hard coat layer, sufficient hard coat performance is easily obtained. On the other hand, when the content of the curable resin is 98% by mass or less, an auxiliary agent such as a photopolymerization initiator or a leveling agent may be added as an optional component, and hardening failure may occur, and the formation of the curable resin layer may be easily maintained. The composition is preferably suitable for application to the plastic substrate 11.

The binder resin may be composed only of the above-mentioned curable resin, or may be other resins. The details will be described later. When the cured resin layer 12 is formed into an antireflection layer, it is preferable to contain a polyfluorene oxide compound or a fluorine resin as another resin. In particular, when a polyfluorene oxide compound is contained, the cured resin layer 12 having a low refractive index can be obtained.

Examples of the polyoxymethylene compound include an alkyl group (extended ethyl group, a propyl group, a butyl group, a hexyl group, a decyl group, etc.), a cycloalkyl group (cyclohexylene group, etc.), and an aryl group. (phenyl or the like), alkyl (methyl, ethyl, propyl, butyl, hexyl, octyl, decyl, etc.), cycloalkyl (cyclohexyl, etc.), alkenyl (vinyl, allyl) An organopolyoxyalkylene such as an acryl group, a butenyl group or a hexenyl group, or an aralkyl group (an aryl group such as a phenyl group or a tolyl group, a benzyl group or a phenylethyl group).

(other ingredients)

The composition for forming a cured resin layer is preferably a photopolymerization initiator in addition to the polyfunctional (meth)acrylic monomer and the antibacterial agent in order to promote the curing.

As the photopolymerization initiator, a known one can be used, and examples thereof include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin isobutyl ether, acetophenone, and dimethylamino phenyl b. Ketone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropane 1-ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2- Orolinyl-propan-1-one, 4-(2-hydroxyethoxy)phenyl-2(hydroxy-2-propyl)one, benzophenone, p-phenylbenzophenone, 4,4' -diethylaminobenzophenone, propiophenone, dichlorobenzophenone, 2-methyloxime, 2-ethylhydrazine, 2-tert-butylhydrazine, 2-aminopurine, 2-methyl 9-oxosulfur 2-ethyl 9-oxosulfur 2-chloro 9-oxosulfur 2,4-dimethyl 9-oxosulfur 2,4-diethyl 9-oxosulfur Benzene dimethyl ketal, acetophenone dimethyl ketal, p-dimethylamino benzoate, and the like. These photopolymerization initiators may be used alone or in combination of two or more.

The blending amount of the photopolymerization initiator is preferably from 0.5 to 10% by mass, and more preferably from 2 to 8% by mass, based on the total mass of the solid content component of the composition for forming a cured resin layer. When it is 0.5% by mass or more, it is difficult to cause curing failure of the resin. Even if it is more than 10% by mass, it is impossible to obtain a hardening promoting effect commensurate with the blending amount, and the cost is also high. Further, there is a cause that it remains in the hardened material and becomes yellow or escaping.

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

The composition for forming a cured resin layer may contain other components than those described above, without departing from the effects of the present invention. For example, it is possible to contain a known additive which is used for imparting other functions (anti-fouling property, antistatic property, ultraviolet shielding property, and the like) to the curable resin layer. Examples of such an additive include a reactive fluorine agent (for example, a fluorine-based antifouling agent for imparting antifouling properties or a fluorine-based antifouling agent for imparting slidability to a finger); and a coating for improving the suitability of the coating. a metal oxide fine particle (excluding an antibacterial agent), an antistatic resin, a conductive polymer for imparting antistatic properties, and metal oxide fine particles (for example, titanium oxide or the like) for imparting ultraviolet shielding properties. Except), UV absorbers, light stabilizers, etc.

Further, the antibacterial agent may be in the form of particles, but an oily organic antibacterial agent may be used in combination with the antibacterial agent.

When the curable resin layer 12 is formed as an antireflection layer, the curable resin layer forming composition preferably contains particles having a balloon (hollow) structure for lowering the refractive index.

The material of the balloon particles may be an organic system such as a styrene-acrylic resin or an inorganic system such as cerium oxide, and is not particularly limited. However, from the viewpoints of transparency and strength for maintaining voids, it is particularly preferable. Ceria.

The average particle diameter of the hollow ceria is preferably from 5 to 180 nm, more preferably from 30 to 100 nm. When the average particle diameter of the hollow ceria is 5 nm or more, the refractive index of the curable resin layer 12 is easily lowered. When the average particle diameter of the hollow ceria is 180 nm or less, the hollow ceria can be densely filled in the curable resin layer 12. Further, the average particle diameter is the same as the average particle diameter of the antibacterial agent, and is a value measured by an observation image of a transmission electron microscope or a scanning electron microscope.

Further, the more the hollow ceria-based hollow portion is, the more easily the refractive index is lowered. Therefore, it is preferable that the thickness of the outer casing is thinner than the average particle diameter. Here, the outer shell of the hollow ceria having a void inside can be observed by a transmission electron microscope (TEM). Further, the hollow portion can also be observed using a transmission electron microscope. In one aspect of the present invention, in the case where the hardened resin layer 12 contains hollow cerium oxide, the bulk density of the hollow cerium oxide is preferably 0.01 in order to lower the refractive index of the hardened resin layer 12. ~0.15g/ml.

When the curable resin layer 12 contains an inorganic antimony-containing compound, the content thereof is preferably from 20 to 80% by mass, more preferably from 30 to 80% by mass based on the total mass of the solid content component of the curable resin layer-forming composition. 70% by mass. When the content of the inorganic cerium-containing compound is 20% by mass or more, the refractive index of the curable resin layer 12 becomes sufficiently low, and it is easy to obtain a higher one. Transmittance. On the other hand, when the content of the inorganic cerium-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 composition for forming a cured resin layer may also contain a solvent.

As the solvent, for example, methanol, ethanol, isopropanol, acetone, methyl ethyl ketone, toluene, n-hexane, n-butanol, 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. These may be used alone or in combination of two or more.

In particular, since coating unevenness can be alleviated, it is preferred to use two or more solvents having different evaporation rates in combination. For example, at least two selected from the group consisting of methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, and propylene glycol monomethyl ether are preferably used in combination.

(function of hardened resin layer)

The hardened resin layer 12 can be formed into a hard coat layer or an antireflection layer according to the compounding composition of the binder resin.

When the hardened resin layer 12 is a hard coat layer, the thickness of the hardened resin layer 12 is preferably from 1 to 10 μm, more preferably from 2 to 8 μm. When the thickness of the hardened resin layer 12 is 1 μm or more, it is easy to obtain sufficient hard coat performance. When the thickness of the hardened resin layer 12 is 10 μm or less, the crimping control is facilitated, and the adhesion to the plastic substrate 11 or the transparency is further improved. Here, "crimping" means "warping" of the antibacterial transparent film due to hardening and shrinkage of the cured resin layer. Further, the thickness of the curable resin layer 12 is a value obtained by measuring the thickness of the plastic substrate from the thickness of the antibacterial transparent film by using a dial gauge.

Further, the refractive index of the hardened resin layer 12 is preferably from 1.40 to 2.00, more preferably from 1.45 to 1.80. When the refractive index of the hardened resin layer 12 is within the above range, it is easy to control the reflection of light.

When the hardened resin layer 12 is a hard coat layer, the antibacterial transparent film shown in FIG. 1 10 can be used as a hard coat film.

On the other hand, when the hardened resin layer 12 is an antireflection layer, the thickness of the hardened 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. Particularly good is 80~120nm. When the thickness of the hardened resin layer 12 is 50 nm or more, the antireflection effect obtained by the dryness of light is easily obtained. When the thickness of the hardened resin layer 12 is 150 nm or less, the adhesion to the plastic substrate 11 is improved.

Further, the refractive index of the hardened resin layer 12 is preferably from 1.25 to 1.45, more preferably from 1.30 to 1.40. When the refractive index of the hardened resin layer 12 is within the above range, it is easy to control the reflection of light.

When the hardened resin layer 12 is an antireflection layer, the antimicrobial transparent film 10 shown in Fig. 1 can be used as an antireflection film.

<physical property>

The arithmetic mean roughness (Ra) measured by JIS B0601-1982 on the surface of the antibacterial transparent film 10 on the surface of the cured resin layer 12 (the surface of the antibacterial transparent film) (hereinafter, sometimes referred to as "Ra ₁ ") It is less than 0.1 μm, preferably 0.05 μm or less. When the Ra of the surface of the antimicrobial transparent film 10 is less than 0.1 μm, the transparency is improved. The lower limit of Ra of the surface of the antibacterial transparent film 10 is not particularly limited as long as it has the effect of the present invention, and is preferably 0.001 μm or more.

Further, in another aspect of the present invention, the surface of the antibacterial transparent film 10 on the side of the hardened resin layer 12 (the surface of the antibacterial transparent film) has an arithmetic mean roughness measured in accordance with ASME B46.12 (hereinafter, It is sometimes referred to as "Ra ₂ "), preferably less than 0.1 μm, more preferably 0.05 μm or less, and particularly preferably less than 0.03 μm.

Further, in another aspect of the present invention, the surface of the antibacterial transparent film 10 on the side of the cured resin layer 12 (the surface of the antibacterial transparent film) has an arithmetic mean roughness measured in accordance with JIS B0601-1994 (hereinafter, Also referred to as "Ra ₃ ") is preferably less than 0.1 μm.

<Measurement of Ra>

The arithmetic mean roughness (Ra ₁ to Ra ₃ ) of the surface of the curable resin layer side of the antibacterial transparent film can be measured by the measurement method shown below.

<Method for measuring Ra ₁ >

The surface of the hardened resin layer of the antibacterial transparent film can be measured according to JIS B0601-1982 using a universal surface shape measuring machine (manufactured by Otaru Research Co., Ltd., "MODEL SE-3C") having a terminal having a apex angle of 90 degrees and a radius of 2 μm. The surface of Ra ₁ .

<Method for measuring Ra ₂ >

The measurement area can be set to 10 μm × 10 μm 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 a single crystal Si according to ASME B46.12. The image was acquired, and the obtained image was processed to calculate Ra _{2 of} the obtained film surface. Further, as the probe, a Si single crystal probe is preferably used.

The image processing described above can also be realized by an image processing apparatus connected to the above-described scanning probe microscope. Further, the image processing device may be a memory and a central processing unit (CPU).

Specifically, a scanning probe microscope (Nanoscopel IV and Nanoscope IIIa manufactured by Veeco Co., Ltd.) was used, and a Si single crystal probe was used as a probe, and the measurement mode was set to Tapping mode, and the measurement area was set to 10 μm × 10 μm. Image acquisition. Preferably, the analysis software attached to the scanning probe microscope is used for the obtained image, and the Flatten treatment (0 times) and the first Planefit treatment (XY) are performed as image processing for removing the undulation. After that, the surface roughness was calculated.

<Method for measuring Ra ₃ >

An ultra-depth shape measuring microscope ("VK-8500" manufactured by Keyence Corporation) having a measuring light source having a diameter of 0.9 μm (wavelength: 685 nm) can be used, and a curable resin of an antibacterial transparent film can be measured according to JIS B0601-1994. Ra ₃ of the surface of the layer side.

The arithmetic surface roughness of the surface of the antibacterial transparent film 10 on the side of the cured resin layer 12 can be adjusted, for example, by the average particle diameter or the added amount of the antibacterial agent contained in the curable resin layer 12. Specifically, the larger the average particle diameter of the antibacterial agent and the more the amount of the antibacterial agent added, the more the arithmetic surface roughness (Ra ₁ , Ra ₂ or Ra ₃ ) tends to become larger, and the average particle size of the antibacterial agent. The smaller the diameter, and the smaller the amount of the antibacterial agent added, the more the Ra ₁ to Ra ₃ tend to become smaller.

Further, the haze value of the antibacterial transparent film 10 measured based on JIS K7136 is preferably 2% or less, and the total light transmittance is preferably 90% or more. Further, the haze value is preferably from 0.1 to 2%, more preferably from 0.3 to 1.5%. Further, the total light transmittance is preferably from 90 to 97%, more preferably from 91 to 95%. When the haze value and the total light transmittance of the antibacterial transparent film are within the above range, the antibacterial transparent film 10 can be preferably used as an optical application.

The haze value is based on the value measured in JIS K7136, and the total light transmittance is based on the value measured in JIS K7361. It means that the percentage of transmitted light that is 0.044 rad (2.5 degrees) or more from the incident light due to scattering by the light passing through the test piece by the light D65 of the CIE standard is used as a light source.

The haze value or total light transmittance of the antibacterial transparent film 10 can be determined by the kind of the resin constituting the plastic substrate 11, the kind of the binder resin constituting the cured resin layer 12, and the surface of the antimicrobial transparent film 10. Ra is adjusted.

<Method for Producing Antibacterial Transparent Film>

The antibacterial transparent film 10 can be produced, for example, in the following manner.

First, a composition for forming a curable resin layer is prepared by mixing an antibacterial agent, a binder resin, and other components as needed. When the curable resin layer 12 is a hard coat layer as described above, the curable resin layer forming composition is a hard coat layer forming composition, and when the curable resin layer 12 is an antireflection layer, it is hardened. The composition for forming a resin layer is a composition for forming an antireflection layer.

Then, the composition for forming a curing resin layer is applied to the plastic substrate 11, and the coating film is dried and cured, whereby the antibacterial property of the hardened resin layer 12 formed on the plastic substrate 11 is obtained. Transparent film 10.

Examples of the coating method of the composition for forming a curing resin layer include a knife coater, an air knife coater, a roll coater, a bar coater, a gravure coater, and a micro gravure coating. A method of a machine, a bar blade coater, a lip coater, a die coater, a curtain coater, a printer, and the like.

The coating amount of the composition for forming a cured resin layer is set in accordance with the thickness of the cured resin layer 12 to be formed.

In the case where the binder resin is an active energy ray-curable resin, the coating film can be cured by irradiation with an active energy ray, and when the binder resin is a thermosetting resin, heating can be used. The furnace or the infrared lamp or the like is heated to be hardened.

Examples of the active energy ray include ionizing radiation such as ultraviolet rays, electron beams, visible rays, and γ rays. Among them, ultraviolet rays are preferred in terms of versatility. As the light source of the ultraviolet light, 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, various electron beam accelerators such as a Kirklev-Walton type, a Van de Graaff type, a resonance transformer type, an insulated core transformer type, a linear type, a high frequency high voltage type, and a high frequency type can be used. The emitted electron beam.

The hardening by irradiation with an active energy ray is preferably carried out in the presence of an inert gas such as nitrogen. Further, the irradiation amount of the active energy ray is preferably from 50 to 2,000 mJ/cm ² , more preferably from 100 to 1,000 mJ/cm ² .

Hardening can be carried out in one stage, and can also be carried out in two stages of a pre-hardening step and a formal hardening step.

<Action 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. Further, the antibacterial transparent film 10 of the present invention reduces both the Ra of the surface of the curable resin layer side and the average particle diameter of the antibacterial agent, specifically, the arithmetic mean roughness of the surface of the curable resin layer (Ra) ₁ , Ra ₂ or Ra ₃ ) is less than 0.1 μm and contains an antibacterial agent having an average particle diameter of 0.5 to 100 nm, thereby having high transparency, and the antibacterial agent is not buried in the hardened resin layer. Give full play to the antibacterial effect.

Therefore, the antibacterial transparent film 10 of the present invention can sufficiently exhibit an antibacterial effect and is excellent in transparency.

In particular, when an antibacterial agent is used as the antibacterial agent, the antibacterial transparent film 10 can be expressed in a small amount, for example, by containing 0.05 to 20% by mass in the curable resin layer. The transparency is not lowered, and the cured resin layer 12 is less likely to be yellowish, which is preferable.

<Use>

The antibacterial transparent film 10 can be used as a hard coat film when the curable resin layer 12 is a hard coat layer, and can be used as an antireflection film when the curable resin layer 12 is an antireflection layer. .

<Other embodiment examples>

The antibacterial transparent film of the present invention is not limited to those shown in Fig. 1 . 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 in which all or a part thereof is removed or can be removed by treatment such as abrasion in the use of the antibacterial transparent film 10 or etching of a subsequent step. By removing all or a part of the other layer 13 during use or before use of the antimicrobial transparent film 10, the cured 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.

In the case where 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 it has the effect of the present invention, and examples thereof include the above-mentioned binder resin or an etching solution. A metal material such as copper that is etched. Again, its There is no need to contain an antibacterial agent in layer 13.

Further, the thickness of the other layer 13 is not particularly limited as long as it has the effect of the present invention, and is preferably 0.1 to 30 μm, more preferably 0.3 to 3 μm.

Further, 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, but may be, for example, the antibacterial transparent film 10 shown in Fig. 4, and the curable resin layer 12 may be composed of two layers. It can also be composed of three or more layers.

Further, the lower layer of the hardened resin layer 12 (the layer in contact with the plastic substrate 11) of the antimicrobial transparent film 10 shown in Fig. 4 is a hard coat layer 12a, and the upper layer (the layer at the outermost layer) is an antireflection layer 12b. .

When the curable resin layer 12 is composed of two or more layers, at least the layer located in the outermost layer contains an antibacterial agent. In the case where the curable resin layer 12 is composed of two or more layers, the total content of the antibacterial agents in each layer is set to 100% by mass based on the total content of all the solid components forming each layer (that is, the respective layers are formed). The total content of the solid content of the composition for forming a cured resin layer is 100% by mass, preferably 0.05 to 20% by mass, more preferably 0.1 to 10% by mass, still more preferably 0.2 to 5% by mass. When 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 be lowered, or the cured resin layer 12 tends to be yellowish. In the case where the resin layer 12 contains a reactive fluorinating agent, the total amount of the antibacterial agent in each layer is 100% by mass based on the total content of all solid components forming each layer (including 0.1% by mass of reactive fluorine). In the case of the agent, it 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 a composition of the same type of curable resin layer, or a composition for forming a different type of curable resin layer. The formed layer, but the hardened resin layer 12 is preferably at least Contains a hard coat. When the hardened resin layer 12 contains at least a hard coat layer, the antimicrobial transparent film 10 can be used as a hard coat film.

Further, for example, as shown in FIG. 4, when the curable resin layer 12 includes the hard coat layer 12a and the antireflection layer 12b, the antibacterial transparent film 10 having both the function of the hard coat film and the antireflection film can be obtained. In the case where the hardened resin layer 12 includes the hard coat layer 12a and the antireflection layer 12b, it is preferable that the antireflection layer 12b is on the outermost layer side. In other words, when the hardened resin layer 12 includes the hard coat layer 12a and the antireflection layer 12b, it is preferable to laminate the antireflection layer 12b on the hard coat layer 12a.

Further, the antibacterial transparent film 10 shown in FIGS. 1 to 4 is formed with a curable resin layer 12 on one surface of the plastic substrate 11, but may be formed on both sides of the plastic substrate 11, for example, as shown in FIG. Hardened resin layer 12.

[Antibacterial adhesive sheet]

Fig. 6 is a cross-sectional view showing the structure of an antimicrobial adhesive sheet according to an embodiment of the present invention.

The antibacterial adhesive sheet 20 of this example is provided with an adhesive layer 21 and a release sheet 22 in this order on the surface of the plastic substrate 11 side of the antimicrobial transparent film 10 shown in Fig. 1 . That is, in one aspect of the invention, the antimicrobial adhesive sheet is characterized in that it comprises a plastic substrate, a cured resin layer, an adhesive layer, and a release sheet, and the adhesive layer is laminated on the release sheet to adhere to the adhesive layer. The plastic substrate is laminated on the layer, and the hardened resin layer is laminated on the plastic substrate, the hardened resin layer contains an antibacterial agent, and the antibacterial agent has an average particle diameter of 0.5 to 100 nm, and the surface of the hardened resin layer is The arithmetic mean roughness (Ra ₁ , Ra ₂ , or Ra ₃ ) is less than 0.1 μm.

<adhesive layer>

The adhesive layer 21 is used to attach the antimicrobial transparent film 10 to the layer of the adherend.

As the adhesive constituting the adhesive layer 21, for example, a natural rubber-based adhesive, a synthetic rubber-based adhesive, an acrylic adhesive, a urethane-based adhesive, or a polyoxygen-based system is used. Adhesives, etc. Further, it may be any of a solvent system, a latex system, and a water system. Among them, in the case of use in an optical system, an acrylic solvent-based adhesive is particularly preferable from the viewpoints of transparency, weather resistance, durability, cost, and the like.

Other additives may also be added to the adhesive as needed. As other auxiliaries, there may be mentioned tackifiers, pH adjusters, adhesives, binders, crosslinking agents, adhesive microparticles, antifoaming agents, antiseptic and antifungal agents, pigments, inorganic fillers, stabilizers, A dampening agent, a wetting agent, and the like.

The thickness of the adhesive layer 21 can be adjusted within a range of 3 to 500 μm. 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 adhesive layer 21 is preferably adjusted in the range of 3 to 500 μm in accordance with the state of the antimicrobial transparent sheet 21. Further, the thickness is more preferably 4 to 300 μm, still more preferably 5 to 150 μm. If the thickness of the adhesive layer 21 is less than 3 μm, it is difficult to control the film thickness and it is likely to become uneven. On the other hand, when the thickness of the adhesive layer 21 exceeds 500 μm, an abnormality may occur in a manufacturing step such as drying or hardening. Further, there is a case where an abnormality such as overflow of the paste occurs in subsequent processing such as press.

<Peeling sheet>

The peeling sheet 22 is, for example, a base material for a release sheet and a release agent layer provided on the side of the adhesive layer 21 of the base material for a release sheet.

Examples of the base material for the release sheet include papers such as Daolin paper and cellophane, and plastic films such as polyethylene terephthalate film or polypropylene film.

As the release agent constituting the release agent layer, for example, a general-purpose addition or condensation type polyoxynitride type release agent or a long-chain alkyl group-containing compound can be used. In particular, an addition type polyfluorene-based release agent having high reactivity can be preferably used.

The thickness of the release sheet 22 is preferably 20 to 100 μm.

<Method for Producing Antibacterial Adhesive Sheet>

The antibacterial adhesive sheet 20 can be obtained, for example, by the following method: an antibacterial transparent film The surface of the plastic substrate 11 on the side of 10 (hereinafter, this surface is also referred to as "the back surface of the antibacterial transparent film") is coated with an adhesive to form the adhesive layer 21, and the release sheet 22 is bonded to the adhesive layer 21. Alternatively, it may be produced by applying an adhesive to the release sheet 22 to form an adhesive layer 21, and bonding the adhesive layer 21 to the back surface of the antimicrobial transparent film 10 to obtain an antimicrobial adhesive sheet 20.

Examples of the method of applying the adhesive include various coating methods exemplified in the description of the method for producing an antimicrobial transparent film.

<How to use>

When the antibacterial transparent film 10 is used, the release sheet 22 of the antimicrobial adhesive sheet 20 is peeled off to expose the adhesive layer 21, and the adhesive layer 21 is bonded to the adherend (for example, the surface of a display or a touch panel or the like).

<Action effect>

The antibacterial adhesive sheet 20 of the present embodiment described above is provided with the adhesive layer 21 on the surface of the plastic substrate 11 of the antibacterial transparent film 10 of the present invention. Therefore, the antibacterial transparent film 10 of the present invention can be used. Fitted to the adherend.

Further, since the antibacterial adhesive sheet 20 shown in Fig. 6 is provided with the release sheet 22 on the adhesive layer 21, the antibacterial transparent film 10 can be stored in a roll shape or the like before being stored and transported.

The antibacterial transparent film of the present invention and the antibacterial adhesive sheet have antibacterial activity at least for the strains of Escherichia coli and Staphylococcus aurous specified in Table 1 of JIS Z2801. Here, the "antibacterial activity" means that the antibacterial activity value measured based on JIS Z2801 is 2.0 or more. That is, it means that the antibacterial activity value defined as the number of bacteria in the unprocessed product after 24 hours of cultivation divided by the number of bacteria in the antibacterial processed product after 24 hours of cultivation is 2.0 or more for any of the above-mentioned bacteria. (more than 99% death rate).

<Another embodiment example>

The antibacterial adhesive sheet of the present invention is not limited to those shown in Fig. 6 . 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, the present invention will be described in detail by way of examples, but the invention should not be construed as limited.

[Manufacturing Example 1: Production of Antibacterial Agent A]

1 part by mass of cerium oxide A (trade name: AEROSIL 300, manufactured by EVONIK Co., Ltd., average particle diameter: 7 nm) was dispersed in 90 parts by mass of water to obtain an aqueous dispersion of cerium oxide. A 2% by mass aqueous sodium hydroxide solution was added thereto to adjust the pH to 10.

Further, water glass diluted to 0.1% by mass, 0.7% by mass aqueous sodium aluminate solution, and 0.05% by mass aqueous silver nitrate solution were separately prepared.

To 85.5 parts by mass of the aqueous dispersion of cerium oxide having a pH adjusted to 10, 13 parts by mass of the previously prepared water glass and 1.5 parts by mass of the aqueous sodium aluminate solution were added and reacted, and then the alkali removal was carried out. Treatment to obtain a bismuth aluminum suspension. 30 parts by mass of the previously prepared silver nitrate aqueous solution was added to 100 parts by mass of the obtained cerium aluminum suspension to obtain an antibacterial agent A carrying silver in cerium oxide.

The average particle diameter of the obtained antimicrobial agent A was measured in the following manner and found to be 10 nm.

<Measurement of average particle size of antibacterial agent>

The maximum length of the particle image of the antimicrobial agent using a transmission electron microscope (Dmax: the maximum length of 2 points on the contour of the particle image) and the maximum length of the vertical length (DV-max: parallel to the maximum length) The length of the shortest length between the two straight lines when the two images are held by the straight line is measured, and the geometric mean value (Dmax × DV - max) ^{1/2 of} the equal value is taken as the particle diameter. The particle diameter of 100 antibacterial agents was measured by this method, and the arithmetic mean value of these was made into the average particle diameter.

[Production Example 2: Production of Antibacterial Agent B]

In addition to the use of cerium oxide B (trade name AEROSIL MOX80, made by EVONIK) In the same manner as in Production Example 1, an antibacterial agent B carrying silver on ruthenium dioxide was obtained in the same manner as in Production Example 1 except that the amount of the particles was changed to 40 nm.

The average particle diameter of the obtained antimicrobial agent B was measured and found to be 50 nm.

[Production Example 3: Manufacturing of Antibacterial Agent C]

The ruthenium dioxide was supported in the same manner as in Production Example 1 except that 1 part by mass of ruthenium dioxide C (trade name: SIRPMA70 WT%-H01, manufactured by CIK NanoTek Co., Ltd., average particle diameter: 700 nm) was used instead of cerium oxide A. There is silver antibacterial agent C.

The average particle diameter of the obtained antimicrobial agent C was measured and found to be 800 nm.

[Example 1] <Preparation of a composition for forming a hard coat layer>

In a dilute solvent obtained by mixing methyl ethyl ketone (MEK) and cyclohexanone in a ratio of 1:1, the solid content is 40% by mass as a polyfunctional (meth)acrylic monomer. 63.6 parts by mass of a functional acrylate (trade name: DPHA, manufactured by Daicel Cytec Co., Ltd.), 27 parts by mass of diethylene glycol diacrylate (trade name: SR230, manufactured by Sartomer Co., Ltd.), and a photopolymerization initiator (trade name: IRGACURE 184, manufactured by BASF Corporation) 5 parts by mass, 4 parts by mass of a photostabilizer (trade name: TINUVIN 152, manufactured by BASF Corporation), and 0.4 parts by mass of an antibacterial agent A (average particle diameter: 10 nm) were prepared to prepare a composition (A) for forming a hard coat layer.

<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 a composition (A) for forming a hard coat layer was applied to the above-mentioned plastic substrate. Thereafter, the film was dried by heating at 80 ° C for 60 seconds, using a high-pressure mercury lamp ultraviolet irradiation machine (manufactured by EYE GRAPHICS Co., Ltd.) at a temperature of 160 W/cm, a lamp height of 13 cm, a belt speed of 10 m/min, and two passes under a nitrogen atmosphere. The ultraviolet ray was irradiated and hardened on a plastic substrate to form a hard coat layer having a thickness of 4 μm as a hardened resin layer, thereby obtaining an antibacterial transparent film.

[Embodiment 2]

The composition for forming a hard coat layer (B) was prepared in the same manner as in Example 1 except that the antibacterial agent B (average particle diameter: 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 (B) for hard coat layer formation was used.

[Example 3]

A hard coat layer was prepared in the same manner as in Example 1 except that the amount of the 6-functional acrylate was changed from 63.6 parts by mass to 63.2 parts by mass, and the amount of the antimicrobial agent A was changed from 0.4 parts by mass to 0.8 parts by mass. The composition for formation (C).

An antibacterial transparent film was obtained in the same manner as in Example 1 except that the obtained composition (C) for hard coat layer formation was used.

[Example 4]

An antibacterial transparent film was obtained in the same manner as in Example 1 except that the hard coating layer-forming composition (A) was applied to the plastic substrate in such a manner that the thickness of the hard-coated hard coat layer was 10 μm.

[Example 5] <Preparation of composition for forming an antireflection layer>

In a dilute solvent in which 1:1 mixture of methyl isobutyl ketone (MIBK) and n-butanol is mixed as a polyfunctional (meth)acrylic monomer, the solid content is 10% by mass. 45.6 parts by mass of a bifunctional acrylate (trade name: DPHA, manufactured by Daicel Cytec Co., Ltd.), 5 parts by mass of diethylene glycol diacrylate (trade name: SR230, manufactured by Sartomer Co., Ltd.), polyfluorene oxide (trade name Silaplane FM-0711, (manufactured by Chisso Co., Ltd.) 38 parts by mass of a hollow cerium oxide sol (manufactured by Nissin Chemicals Co., Ltd.) having a mass fraction of 60 nm and a photopolymerization initiator (trade name: IRGACURE 184, manufactured by BASF), 4 parts by mass, and light stable The antireflection layer-forming composition (D) was prepared by using 4 parts by mass of a chemical agent (trade name: TINUVIN 152, manufactured by BASF Corporation) and 0.4 parts by mass of an antibacterial agent A (average particle diameter: 10 nm).

<Manufacture of antibacterial transparent film>

The composition (A) for forming a hard coat layer was applied to a plastic substrate in the same manner as in Example 1 to dry and harden the coating film, and a hard coat layer having a thickness of 4 μm was formed on the plastic substrate.

Then, the composition (D) for forming an antireflection layer was applied to the hard coat layer in a bar. Thereafter, the film was dried by heating at 80 ° C for 60 seconds, using a high-pressure mercury lamp ultraviolet irradiation machine (manufactured by EYE GRAPHICS Co., Ltd.) at a temperature of 160 W/cm, a lamp height of 13 cm, a belt speed of 10 m/min, and two passes under a nitrogen atmosphere. The ultraviolet ray was irradiated and hardened on the hard coat layer to form an antireflection layer having a thickness of 100 nm to obtain an antibacterial transparent film. Further, the curable resin layer of the obtained antibacterial transparent film was composed of a hard coat layer having a thickness of 4 μm and a two-layer structure having an antireflection layer having a thickness of 100 nm.

[Embodiment 6]

In addition, the amount of the 6-functional acrylate was changed from 63.6 parts by mass to 63.4 parts by mass, and the amount of the antimicrobial agent A was changed from 0.4 parts by mass to 0.5 parts by mass, and further, a reactive fluorochemical agent (trade name MEGAFAC RS-) was used. 75. A composition for forming a hard coat layer (E) was prepared in the same manner as in Example 1 except that 0.1 parts by mass of 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 composition (F) for forming a hard coat layer was prepared in the same manner as in Example 1 except that the antibacterial agent C (average particle diameter: 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 hard coat layer-forming composition (F) was used.

[Comparative Example 2] <Preparation of a composition for forming a hard coat layer>

In a dilute solvent obtained by mixing methyl ethyl ketone (MEK) and cyclohexanone in a ratio of 1:1, the solid content is 40% by mass as a polyfunctional (meth)acrylic acid single. 53.6 parts by mass of a bifunctional acrylate (trade name: DPHA, manufactured by Daicel Cytec Co., Ltd.), 27 parts by mass of diethylene glycol diacrylate (trade name: SR230, manufactured by Sartomer Co., Ltd.), and a photopolymerization initiator (trade name: IRGACURE 184, 5 parts by mass, a light stabilizer (trade name: TINUVIN 152, manufactured by BASF Corporation), 4 parts by mass, cerium oxide (trade name: AZ-204, manufactured by Tosoh. Silica Co., Ltd.), 10 parts by mass, and an antibacterial agent A 0.4. A composition (G) for forming a hard coat layer was prepared in parts by mass.

<Manufacture of antibacterial transparent film>

A composition for forming a hard coat layer was applied to 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). The coating film was dried and hardened to form a hard coat layer having a thickness of 4 μm on the plastic substrate.

Then, the composition (D) for forming an antireflection layer was applied to the hard coat layer in a bar. Thereafter, the film was dried by heating at 80 ° C for 60 seconds, using a high-pressure mercury lamp ultraviolet irradiation machine (manufactured by EYE GRAPHICS Co., Ltd.) at a temperature of 160 W/cm, a lamp height of 13 cm, a belt speed of 10 m/min, and two passes under a nitrogen atmosphere. The ultraviolet ray was irradiated and hardened on the hard coat layer to form an antireflection layer having a thickness of 100 nm to obtain an antibacterial transparent film. Further, the curable resin layer of the obtained antibacterial transparent film was composed of a hard coat layer having a thickness of 4 μm and a two-layer structure having an antireflection layer having a thickness of 100 nm.

[Measurement, evaluation method]

The Ra of the surface of the antibacterial transparent film and the haze value and total light transmittance of the antibacterial transparent film were measured for the antibacterial transparent film obtained in each of the examples by the method shown below, and the pencil hardness, light resistance, and antibacterial property were evaluated. active. The results are shown in Table 1.

Further, Table 1 shows the average particle diameter and content of the antibacterial agent, the content of the reactive fluorinating agent, and the thickness of the curable resin layer in the cured resin layer of each example. In addition, the content of the antibacterial agent shown in Table 1 is an amount of 100% by mass of the solid content component of the composition for forming a hard coat layer or the composition for forming an antireflection layer. In addition, in Example 5 and Comparative Example 2, the total content of the antibacterial agent contained in the hard coat layer and the antireflection layer is shown in Table 1.

<Measurement of Ra>

Ra ₁ to Ra ₃ of the surface of the curable resin layer side of the antibacterial transparent film were measured. The results are shown in Table 1.

<Method for measuring Ra ₁ >

The surface of the hardened resin layer of the antibacterial transparent film can be measured according to JIS B0601-1982 using a universal surface shape measuring machine (manufactured by Otaru Research Co., Ltd., "MODEL SE-3C") having a terminal having a apex angle of 90 degrees and a radius of 2 μm. The surface of Ra ₁ .

<Method for measuring Ra ₂ >

The measurement area can be set to 10 μm × 10 μm 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 a single crystal Si according to ASME B46.12. The image was acquired, and the obtained image was processed to calculate Ra _{2 of} the obtained film surface. Further, as the probe, a Si single crystal probe is preferably used.

The image processing described above can also be realized by an image processing apparatus connected to the above-described scanning probe microscope. Further, the image processing device may be provided with a memory and a central processing unit (CPU).

Specifically, a scanning probe microscope (Nanoscopel IV and Nanoscope IIIa manufactured by Veeco Co., Ltd.) was used, and a Si single crystal probe was used as a probe, and the measurement mode was set to Tapping mode, and the measurement area was set to 10 μm × 10 μm. Image acquisition. Preferably, the analysis software attached to the scanning probe microscope is used for the obtained image, and the Flatten treatment (0 times) and the first Planefit treatment are performed as image processing for removing the undulation. After (XY), the surface roughness was calculated.

<Method for measuring Ra ₃ >

An ultra-depth shape measuring microscope ("VK-8500" manufactured by Keyence Corporation) having a measuring light source having a diameter of 0.9 μm (wavelength: 685 nm) can be used, and a curable resin of an antibacterial transparent film can be measured according to JIS B0601-1994. Ra ₃ of the surface of the layer side.

<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 antimicrobial 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 to a 2 mm-thick glass plate by a transparent tape, and a scratch test on the surface of the hardened resin layer side was performed using a pencil based on JIS K5400-1990. The judgment was evaluated by the damage of the hardened resin layer.

<Evaluation of light resistance>

Using a xenon arc lamp weathering tester manufactured by Suga Test Instruments, a xenon lamp is used as a light source, and light having a wavelength of 275 nm or more is set to have an irradiation amount of 60 W/m ² in a wavelength region of 300 to 400 nm, and is set. The side of the curable resin layer of the antibacterial transparent film was irradiated for 24 hours to carry out an accelerated exposure test.

The hue of the antibacterial transparent film before and after the exposure test was measured, and ΔE was obtained by the following formula, and the hue change was evaluated.

△E={(L ^* _b -L ^* _a ) ² +(a ^* _b -a ^* _a ) ² +(b ^* _b -b ^* _a ) ² } ^1/2

Further, in the formula, L ^* _b , a ^* _b , b ^* _b represent the hue (L ^* , a ^* , b ^* ) of the antibacterial transparent film before the exposure test, L ^* _a , a ^* _a , b ^* _a represents the hue (L ^* , a ^* , b ^* ) of the antibacterial transparent film after the exposure test.

<Evaluation of antibacterial activity>

The antibacterial activity values of Staphylococcus aureus and Escherichia coli were determined based on JIS Z2801.

According to Table 1, it is understood that the antibacterial transparent film obtained in each of Examples 1 to 6 in which the average particle diameter of the antibacterial agent is 0.5 to 100 nm and the Ra of the surface of the cured resin layer side is less than 0.1 μm can be sufficiently obtained. It exhibits an antibacterial effect and is excellent in transparency and light resistance. Further, the antibacterial transparent film obtained in each of the examples has a sufficient pencil hardness and is preferable 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 was 800 nm could not sufficiently exhibit the antibacterial effect.

The antibacterial transparent film obtained in Comparative Example 2 having a Ra of 0.3 to 0.5 μm on the surface of the hardened resin layer side was inferior in transparency.

10‧‧‧Antibacterial transparent film

11‧‧‧Plastic substrate

12‧‧‧ hardened resin layer

Claims (8)

An antibacterial transparent film comprising a plastic substrate and a hardened resin layer laminated on at least one side of the plastic substrate, wherein the curable resin layer contains an antibacterial agent, and the antibacterial agent has an average of 0.5 to 100 nm. The particle size, the arithmetic mean roughness (Ra) of the surface of the above-mentioned hardened resin layer measured according to JIS B0601-1982 is less than 0.1 μm. The antibacterial transparent film of claim 1, wherein the antibacterial agent is an inorganic oxide supporting an antibacterial metal component. The antibacterial transparent film of claim 1, wherein the hardened resin layer is provided on the outermost layer of the antibacterial transparent film. The antibacterial transparent film of claim 2, wherein the hardened resin layer is provided on the outermost layer of the antibacterial transparent film. The antimicrobial transparent film according to any one of claims 1 to 4, wherein the hardened resin layer comprises a hard coat layer. The antibacterial transparent film according to any one of claims 1 to 4, wherein the antibacterial transparent film has a haze value of 2% or less based on JIS K7136, and a total light transmittance of 90% based on JIS K7361. the above. The antibacterial transparent film of claim 5, wherein the antibacterial transparent film has a haze value of not more than 2% based on JIS K7136, and a total light transmittance of 90% or more measured based on JIS K7361. An antibacterial adhesive sheet comprising the antibacterial transparent film according to any one of claims 1 to 7 and an adhesive layer, and a plastic substrate having the above-mentioned antibacterial transparent film laminated on the adhesive layer.