JP2017121744A - Light-transmitting conductive film laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light-transmitting conductive film laminate having excellent flex resistance.SOLUTION: A light-transmitting conductive film laminate 1 has a light-transmitting conductive film 2, an adhesive layer 3 and a protection film 4, the light-transmitting conductive film 2 has a conductive layer 6, a first hard coat layer 7, a first substrate film 5 and a second hard coat layer 8, the protection film 4 has a second substrate film 9 and an oligomer prevention layer 10, the first and second hard coat layers 7,8 each have a thickness of 0.5 μm or more and 3.0 μm or less, the oligomer prevention layer 10 has a thickness of 0.01 μm or more and 0.1 μm or less, the first and second hard coat layers 7,8 each have a pencil hardness of 5B or more and 3B or less, the oligomer prevention layer 10 has a pencil hardness of F or more and 2H or less, and the adhesive layer 3 has a storage elastic modulus of 4.0×10Pa or more and 2.0×10Pa or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a light transmissive conductive film laminate in which a protective film is disposed on a light transmissive conductive film having light transmissive and conductive properties.

  In recent years, touch panel liquid crystal display devices have been widely used in electronic devices such as smartphones, mobile phones, notebook computers, tablet PCs, copiers, and car navigation systems. In such a liquid crystal display device, a light transmissive conductive film in which a transparent conductive layer is laminated on a base film is used. Moreover, the protective film may be provided in the surface on the opposite side to the said transparent conductive layer of a base film. By providing the protective film, the surface of the base film opposite to the transparent conductive layer is prevented from being contaminated or damaged.

Patent Document 1 below discloses a light-transmitting conductive film laminate in which a protective film is bonded to a surface of a base film opposite to the transparent conductive layer via an adhesive layer. Patent Document 1 describes that the storage elastic modulus of the pressure-sensitive adhesive layer is 2.0 × 10 ⁵ Pa or more and less than 1.0 × 10 ⁷ Pa.

Japanese Patent No. 5529720

  The light-transmitting conductive film laminate as in Patent Document 1 may be bent at the time of inspection or use. If the light-transmitting conductive film laminate is bent, a crack may occur in the conductive layer. When a crack occurs in the conductive layer, there is a problem that sheet resistance (film resistance) increases.

  An object of the present invention is to provide a light-transmitting conductive film laminate having excellent bending resistance.

According to a wide aspect of the present invention, a light-transmitting conductive film having light transmittance and conductivity, a pressure-sensitive adhesive layer laminated on the surface of the light-transmitting conductive film, and the pressure-sensitive adhesive layer A protective film laminated on a surface opposite to the light transmissive conductive film, wherein the light transmissive conductive film is disposed on the surface of the conductive layer and the conductive layer. A coating layer; a first base film disposed on a surface of the first hard coat layer opposite to the conductive layer; and the first hard coat layer of the first base film; Has a second hard coat layer disposed on the surface on the opposite side, and the protective film has a second base film disposed on the opposite side to the pressure-sensitive adhesive layer, and the second Arranged on the surface of the base film and disposed on the adhesive layer side. An oligomer prevention layer, wherein the thickness of the first hard coat layer is 0.5 μm or more and 3.0 μm or less, and the thickness of the second hard coat layer is 0.5 μm or more, 3.0 μm or less, the thickness of the oligomer prevention layer is 0.01 μm or more and 0.1 μm or less, the pencil hardness of the first hard coat layer is 5B or more and 3B or less, and the second The pencil hardness of the hard coat layer is 5B or more and 3B or less, the pencil hardness of the oligomer prevention layer is F or more and 2H or less, and the storage elastic modulus at a frequency of 1 Hz and a temperature of 23 ° C. Is provided with a light-transmitting conductive film laminate having 4.0 × 10 ⁴ Pa or more and 2.0 × 10 ⁵ Pa or less.

  On the specific situation with the transparent electroconductive film laminated body which concerns on this invention, a said 1st hard-coat layer has a resin part and a filler.

  On the specific situation with the transparent electroconductive film laminated body which concerns on this invention, a said 2nd hard-coat layer has a resin part and a filler.

  The light-transmitting conductive film laminate according to the present invention is suitably used for a liquid crystal display device.

  Since the light transmissive conductive film laminate according to the present invention has the above-described configuration, it has excellent bending resistance. Since it is excellent in bending resistance, it is difficult for cracks to occur in the conductive layer and sheet resistance is unlikely to increase. Therefore, the light transmissive conductive film laminate of the present invention is excellent in reliability.

FIG. 1 is a schematic cross-sectional view of a light transmissive conductive film laminate according to an embodiment of the present invention. FIG. 2 is a schematic configuration diagram for explaining a bending resistance evaluation method.

  Hereinafter, the present invention will be described in detail.

  The light transmissive conductive film laminate according to the present invention includes a light transmissive conductive film, a pressure-sensitive adhesive layer, and a protective film. An adhesive layer is laminated on the surface of the light transmissive conductive film. The protective film is laminated | stacked on the surface on the opposite side to the said light transmissive conductive film of the said adhesive layer.

  The light transmissive conductive film includes a conductive layer, a first hard coat layer, a first base film, and a second hard coat layer. On the surface of the conductive layer, the first hard coat layer, the first base film, and the second hard coat layer are arranged in this order.

  The protective film includes a second base film and an oligomer prevention layer. The second base film is disposed on the side opposite to the pressure-sensitive adhesive layer. An oligomer prevention layer is laminated on the surface of the second base film. The said oligomer prevention layer is arrange | positioned at the said adhesive layer side, and is in contact with the said adhesive layer.

In the light transmissive conductive film laminate of the present invention, the thickness of the first hard coat layer is 0.5 μm or more and 3.0 μm or less. The thickness of the second hard coat layer is not less than 0.5 μm and not more than 3.0 μm. The oligomer prevention layer has a thickness of 0.01 μm or more and 0.1 μm or less. The pencil hardness of the first hard coat layer is 5B or more and 3B or less. The pencil hardness of the second hard coat layer is 5B or more and 3B or less. The pencil hardness of the oligomer prevention layer is F or more and 2H or less. The storage elastic modulus at a frequency of 1 Hz and a temperature of 23 ° C. of the pressure-sensitive adhesive layer is 4.0 × 10 ⁴ Pa or more and 2.0 × 10 ⁵ Pa or less.

  Since the light transmissive conductive film laminate of the present invention has the above-described configuration, it has excellent bending resistance. In addition, since the light-transmitting conductive film laminate of the present invention is excellent in bending resistance, cracks or the like hardly occur in the conductive layer even when bent at the time of inspection or use, and the sheet resistance is low. It is hard to rise. Therefore, the light transmissive conductive film laminate of the present invention is excellent in reliability.

  In addition, the light-transmitting conductive film laminate is used in a liquid crystal display device because the sheet resistance hardly increases even when the light-transmitting conductive film laminate according to the present invention is bent during inspection or use. If so, quality and reliability can be improved. Therefore, the light-transmitting conductive film laminate can be suitably used for a liquid crystal display device, and can be suitably used for a touch panel.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view of a light transmissive conductive film laminate according to an embodiment of the present invention. As shown in FIG. 1, the light transmissive conductive film laminate 1 includes a light transmissive conductive film 2, an adhesive layer 3, and a protective film 4. An adhesive layer 3 and a protective film 4 are arranged and laminated in this order on the light transmissive conductive film 2.

  The light transmissive conductive film 2 is a film having light transmittance and conductivity. The light transmissive conductive film 2 includes a conductive layer 6, a first hard coat layer 7, a first base film 5, and a second hard coat layer 8. On the surface of the conductive layer 6, the first hard coat layer 7, the first base film 5, and the second hard coat layer 8 are arranged and laminated in this order.

  The first base film 5 is made of a material having high light transmittance. The first base film 5 has a first surface 5a and a second surface 5b. The first surface 5a and the second surface 5b are opposed to each other. On the first surface 5a, the first hard coat layer 7 and the conductive layer 6 are arranged and laminated in this order. The first surface 5a is a surface on the side where the conductive layer 6 is disposed. The first base film 5 is a member disposed between the conductive layer 6 and the protective film 4 and is a support member for the conductive layer 6. The first hard coat layer 7 satisfies the specific thickness and the pencil hardness.

  The light transmissive conductive film 2 has a portion with the conductive layer 6 and a portion without the conductive layer 6 on the surface of the first hard coat layer 7. The conductive layer 6 may be formed on the entire surface of the first hard coat layer 7 opposite to the first base film 5. In the present invention, the conductive layer 6 may be provided on the first hard coat layer 7 via an undercoat layer. The undercoat layer is, for example, a refractive index adjustment layer.

  A second hard coat layer 8 is disposed and laminated on the second surface 5 b of the first base film 5. The second surface 5b is a surface on the side where the pressure-sensitive adhesive layer 3 and the protective film 4 are arranged. The pressure-sensitive adhesive layer 3 is disposed and laminated on the opposite side of the second hard coat layer 8 from the first base film 5. The second hard coat layer 8 satisfies the specific thickness and the pencil hardness.

  The pressure-sensitive adhesive layer 3 has light transmittance. The pressure-sensitive adhesive layer 3 satisfies the specific storage elastic modulus. A protective film 4 is disposed and laminated on the side of the pressure-sensitive adhesive layer 3 opposite to the light transmissive conductive film 2.

  By providing the protective film 4, the surface of the pressure-sensitive adhesive layer 3 opposite to the light transmissive conductive film 2 is protected. In addition, by providing the protective film 4 and the pressure-sensitive adhesive layer 3, the surface of the light transmissive conductive film 2 on the second hard coat layer 8 side is protected.

  The protective film 4 includes a second base film 9 and an oligomer prevention layer 10. The second base film 9 is disposed on the side opposite to the pressure-sensitive adhesive layer 3. On the surface of the second base film 9, the oligomer prevention layer 10 is disposed and laminated. The oligomer prevention layer 10 is disposed on the pressure-sensitive adhesive layer 3 side and is in contact with the pressure-sensitive adhesive layer 3. The oligomer prevention layer 10 satisfies the specific thickness and the pencil hardness.

  Next, an example of the manufacturing method of the transparent conductive film laminated body 1 shown in FIG. 1 is demonstrated.

  The light transmissive conductive film laminate 1 can be produced, for example, by the following method.

  A first hard coat layer 7 is formed on the first surface 5 a of the first base film 5. Specifically, when an ultraviolet curable resin is used as the resin, a photocurable monomer and a photoinitiator are stirred in a diluent to prepare a coating solution. The obtained coating liquid is applied onto the first surface 5 a of the first base film 5, and the resin is cured by irradiating ultraviolet rays to form the first hard coat layer 7.

  Subsequently, the second hard coat layer 8 is formed on the second surface 5 b of the first base film 5. Specifically, when an ultraviolet curable resin is used as the resin, a photocurable monomer and a photoinitiator are stirred in a diluent to prepare a coating solution. The obtained coating liquid is applied to the second surface 5 b of the first base film 5, and the resin is cured by irradiating ultraviolet rays to form the second hard coat layer 8.

  Next, the pressure-sensitive adhesive layer 3 is formed on the surface of the second hard coat layer 8 opposite to the first base film 5. For example, when forming the pressure-sensitive adhesive layer 3 with a (meth) acrylic pressure-sensitive adhesive, a tackifying resin or the like is added to the (meth) acrylic polymer and the crosslinking agent as necessary, and a solvent is added to the pressure-sensitive adhesive layer. Make a solution. This adhesive solution is applied on the surface of the second hard coat layer 8 opposite to the first base film 5. While the solvent in the solution is removed by drying, the crosslinking of the (meth) acrylic polymer is advanced to form the pressure-sensitive adhesive layer 3.

  Subsequently, the protective film 4 is disposed on the surface of the pressure-sensitive adhesive layer 3 opposite to the second hard coat layer 8. The protective film 4 is arrange | positioned by bonding together on the surface of the adhesive layer 3 from the oligomer prevention layer 10 side. The oligomer prevention layer 10 can be formed on the surface of the second base film 9 by using, for example, a coating method, a spray method, a spin coating method, a vapor deposition method or a sputtering method.

  Next, by forming the conductive layer 6 on the first hard coat layer 7, the light transmissive conductive film laminate 1 can be produced.

  The method for forming the conductive layer is not particularly limited. For example, a method of etching a metal film formed by vapor deposition or sputtering, various printing methods such as screen printing or inkjet printing, and a known patterning method such as a photolithography method using a resist can be used. The formed conductive layer is preferably used with its crystallinity enhanced by annealing treatment.

  The light transmissive conductive film laminate 1 may be used with the protective film 4 laminated, or may be used after the protective film 4 is peeled off.

  Hereinafter, the detail of each layer which comprises a transparent conductive film laminated body is demonstrated.

(Light transmissive conductive film)
The total thickness of the light transmissive conductive film is preferably 50 μm or more, more preferably 100 μm or more, preferably 300 μm or less, more preferably 200 μm or less.

A first substrate film;
The thickness of the first base film is preferably 2 μm or more, more preferably 10 μm or more, preferably 100 μm or less, more preferably 50 μm or less. When the thickness of the first base film is not less than the above lower limit and not more than the above upper limit, the bending resistance can be further enhanced.

  The first base film preferably has high light transmittance. Accordingly, the material for the first base film is not particularly limited. For example, polyolefin, polyethersulfone, polysulfone, polycarbonate, cycloolefin polymer, polyarylate, polyamide, polymethyl methacrylate, polyethylene terephthalate, polybutylene terephthalate. , Polyethylene naphthalate, triacetyl cellulose, and cellulose nanofibers. The material for the first base film may be used alone or in combination.

  Regarding the light transmittance of the first base film, the average transmittance in the visible light region with a wavelength of 380 to 780 nm is preferably 85% or more, more preferably 90% or more.

  Moreover, the 1st base film may contain various stabilizers, a ultraviolet absorber, a plasticizer, a lubricant, or a coloring agent.

First and second hard coat layers;
The thicknesses of the first and second hard coat layers are 0.5 μm or more and 3.0 μm or less, respectively. The pencil hardness of the first and second hard coat layers is 5B or more and 3B or less, respectively.

  By forming the first and second hard coat layers having the above specific thickness and pencil hardness, the bending resistance of the light transmissive conductive film laminate can be improved, The sheet resistance can be made difficult to increase. Specifically, when the thickness and pencil hardness of the first and second hard coat layers are within the above ranges, the first base film is hardly pulled. If the first base film is difficult to be pulled, cracks are unlikely to occur in the conductive layer, and the flex resistance of the light transmissive conductive film laminate is improved. As a result, even if the light transmissive conductive film laminate is bent, the sheet resistance of the light transmissive conductive film laminate is difficult to increase.

  From the viewpoint of further improving the bending resistance of the light transmissive conductive film laminate and making it difficult to further increase the sheet resistance, the thicknesses of the first and second hard coat layers are each preferably 0.6 μm or more, preferably Is 2.9 μm or less.

  Each of the first and second hard coat layers is preferably composed of a binder resin. The binder resin is preferably a cured resin. As the curable resin, a thermosetting resin, an active energy ray curable resin, or the like can be used. From the viewpoint of improving productivity and economy, the curable resin is preferably an ultraviolet curable resin.

  Examples of the photocurable monomer for forming the ultraviolet curable resin include 1,6-hexanediol diacrylate, 1,4-butanediol diacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, and tetraethylene glycol diacrylate. , Tripropylene glycol diacrylate, neopentyl glycol diacrylate, 1,4-butanediol dimethacrylate, poly (butanediol) diacrylate, tetraethylene glycol dimethacrylate, 1,3-butylene glycol diacrylate, triethylene glycol diacrylate Such as triisopropylene glycol diacrylate, polyethylene glycol diacrylate and bisphenol A dimethacrylate Triacrylate compounds such as trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol monohydroxytriacrylate and trimethylolpropane triethoxytriacrylate; of pentaerythritol tetraacrylate and di-trimethylolpropane tetraacrylate And tetraacrylate compounds such as dipentaerythritol (monohydroxy) pentaacrylate. As the ultraviolet curable resin, a polyfunctional acrylate having 5 or more functional groups may be used. The said polyfunctional acrylate may be used independently and may use multiple together. Moreover, you may add a photoinitiator, a photosensitizer, a leveling agent, a diluent, etc. to the said polyfunctional acrylate compound.

  Moreover, the 1st and 2nd hard-coat layer may be comprised with the resin part and the filler, respectively. When the first and second hard coat layers contain a filler, the bending resistance of the light transmissive conductive film laminate can be further enhanced. Each of the first and second hard coat layers may be constituted only by the resin portion.

  Examples of the filler include, but are not limited to, metal oxides such as silica, iron oxide, aluminum oxide, zinc oxide, titanium oxide, silicon dioxide, antimony oxide, zirconium oxide, tin oxide, cerium oxide, and indium-tin oxide. Product particles; resin particles such as silicone, (meth) acryl, styrene, melamine, and the like. More specifically, resin particles such as crosslinked poly (meth) methyl acrylate can be used. The said filler may be used independently and may use multiple together.

  The first and second hard coat layers may each contain various stabilizers, ultraviolet absorbers, plasticizers, lubricants, or colorants.

Undercoat layer;
The undercoat layer is, for example, a refractive index adjustment layer. By providing the undercoat layer, the difference in refractive index between the conductive layer and the first hard coat layer or the first base film can be reduced, so that the light transmissive conductive film and the light transmissive The light transmittance of the conductive film laminate can be further enhanced. Note that the undercoat layer may not be provided.

As a material constituting the undercoat layer, a material having a refractive index adjusting function or the like is appropriately selected, and an inorganic material such as SiO _x (x = 1.0 to 2.0), SiO ₂ , MgF ₂ , Al ₂ O ₃ or the like. Examples thereof include organic materials such as materials and acrylic resins, urethane resins, melamine resins, alkyd resins, and siloxane polymers.

  The undercoat layer can be formed by a vacuum deposition method, a sputtering method, an ion plating method, or a coating method.

Conductive layer;
The conductive layer is made of a light-transmitting conductive material. As the conductive material is not particularly limited, for example, IZO (indium zinc oxide) or, In-based oxides such as ITO (indium tin _oxide), Sn, such as SnO 2, FTO (fluorine-doped tin oxide) Oxide, AZO (aluminum zinc oxide), Zn oxide such as GZO (gallium zinc oxide), sodium, sodium-potassium alloy, lithium, magnesium, aluminum, magnesium-silver mixture, magnesium-indium mixture, aluminum - lithium alloy, Al / _Al 2 _{O 3} mixture, Al / LiF mixture, a metal such as gold, CuI, Ag nanowire (AgNW), such as carbon nanotubes (CNT) or conductive transparent polymers. The said electroconductive material may be used independently and may use multiple together.

From the viewpoint of further increasing the conductivity and further increasing the light transmittance, the conductive material is selected from In-based oxides such as IZO (indium zinc oxide) and ITO (indium tin oxide), SnO ₂ , FTO. Sn-based oxides such as (fluorine-doped tin oxide), Zn-based oxides such as AZO (aluminum zinc oxide) and GZO (gallium zinc oxide) are preferable, and ITO (indium tin oxide) is preferable. Is more preferable.

  The thickness of the conductive layer is preferably 12 nm or more, more preferably 17 nm or more, preferably 50 nm or less, more preferably 30 nm or less.

  When the thickness of a conductive layer is more than the said minimum, the electroconductivity of a transparent conductive film and a transparent conductive film laminated body can be improved further.

  Regarding the light transmittance of the conductive layer, the average transmittance in the visible light region is preferably 85% or more, more preferably 90% or more.

  A refractive index adjusting layer similar to the undercoat layer may be provided between the conductive layer and the hard coat layer.

(Adhesive layer)
The storage elastic modulus at a frequency of 1 Hz and a temperature of 23 ° C. of the pressure-sensitive adhesive layer is 4.0 × 10 ⁴ Pa or more and 2.0 × 10 ⁵ Pa or less. The storage elastic modulus is measured by dynamic viscoelasticity measurement. The dynamic viscoelasticity measurement is performed under conditions of a frequency of 1 Hz and a strain of 3% using a melt viscoelasticity measuring device.

  By forming the pressure-sensitive adhesive layer having the above specific storage elastic modulus, the bending resistance of the light transmissive conductive film laminate can be increased, and the sheet resistance of the light transmissive conductive film laminate is hardly increased. be able to. More specifically, when the storage elastic modulus of the pressure-sensitive adhesive layer is not less than the above lower limit, the first base film becomes difficult to be pulled, and the flex resistance of the light transmissive conductive film laminate is improved. Moreover, when the storage elastic modulus of an adhesive layer is below the said upper limit, a transparent conductive film becomes difficult to peel from an adhesive layer, and the bending resistance of a transparent conductive film laminated body improves. As a result, even if the light transmissive conductive film laminate is bent, the sheet resistance of the light transmissive conductive film laminate is difficult to increase.

  The pressure-sensitive adhesive layer can be composed of a (meth) acrylic pressure-sensitive adhesive, a rubber-based pressure-sensitive adhesive, a urethane-based adhesive, or an epoxy-based adhesive. From the viewpoint of suppressing an increase in adhesive force due to heat treatment, the adhesive layer is preferably composed of a (meth) acrylic adhesive.

  The (meth) acrylic pressure-sensitive adhesive is a pressure-sensitive adhesive in which a crosslinking agent, a tackifier resin, various stabilizers, and the like are added to a (meth) acrylic polymer as necessary.

  The (meth) acrylic polymer is not particularly limited, but (meth) acrylic copolymer obtained by copolymerizing a mixed monomer containing a (meth) acrylic acid ester monomer and another copolymerizable monomer. A polymer is preferred.

  Although it does not specifically limit as said (meth) acrylic acid ester monomer, It is obtained by esterification reaction of the primary or secondary alkyl alcohol whose carbon number of an alkyl group is 1-12, and (meth) acrylic acid ( A (meth) acrylate monomer is preferable, and specific examples include ethyl (meth) acrylate, butyl (meth) acrylate, and (meth) acrylate-2-ethylhexyl. The said (meth) acrylic acid ester monomer may be used independently and may use multiple together.

  Examples of other polymerizable monomers that can be copolymerized include hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, and hydroxybutyl (meth) acrylate; Isobornyl (meth) acrylate, hydroxyalkyl (meth) acrylate, glycerin dimethacrylate, glycidyl (meth) acrylate, 2-methacryloyloxyethyl isocyanate, (meth) acrylic acid, itaconic acid, maleic anhydride, crotonic acid, malein Examples thereof include functional monomers such as acid and fumaric acid. The said other polymerizable monomer which can be copolymerized may be used independently, and may use multiple together.

  The crosslinking agent is not particularly limited, and for example, an isocyanate crosslinking agent, an epoxy crosslinking agent, a melamine crosslinking agent, a peroxide crosslinking agent, a urea crosslinking agent, a metal alkoxide crosslinking agent, a metal chelate crosslinking agent. Agents, metal salt crosslinking agents, carbodiimide crosslinking agents, oxazoline crosslinking agents, aziridine crosslinking agents, amine crosslinking agents, polyfunctional acrylates and the like. The above crosslinking agents may be used alone or in combination.

  The tackifying resin is not particularly limited, and examples thereof include petroleum resins such as aliphatic copolymers, aromatic copolymers, aliphatic / aromatic copolymers, and alicyclic copolymers. Coumarone-indene resin; terpene resin; terpene phenol resin; rosin resin such as polymerized rosin; phenol resin; xylene resin. The tackifying resin may be a hydrogenated resin. The tackifying resins may be used alone or in combination.

  The thickness of the pressure-sensitive adhesive layer is preferably 2 μm or more, more preferably 5 μm or more, preferably 50 μm or less, more preferably 30 μm or less. When the thickness of the pressure-sensitive adhesive layer is not less than the above lower limit and not more than the above upper limit, the bending resistance can be further enhanced.

(Protective film)
The total thickness of the protective film is preferably 10 μm or more, more preferably 30 μm or more, preferably 200 μm or less, more preferably 150 μm or less.

A second substrate film;
The second substrate film preferably has high light transmittance. However, the second base film may not have light transmittance. The material for the second base film is not particularly limited. For example, polyolefin, polyethersulfone, polysulfone, polycarbonate, cycloolefin polymer, polyarylate, polyamide, polymethyl methacrylate, polyethylene terephthalate, polybutylene terephthalate, Examples thereof include polyethylene naphthalate, triacetyl cellulose, and cellulose nanofiber.

  Regarding the light transmittance of the second base film, the average transmittance in the visible light region with a wavelength of 380 to 780 nm is preferably 85% or more, more preferably 90% or more.

  The second base film may contain various stabilizers, ultraviolet absorbers, plasticizers, lubricants, or colorants.

Oligomer prevention layer;
The oligomer prevention layer is a layer for preventing migration of oligomer components present in the second base film.

  The thickness of the oligomer prevention layer is 0.01 μm or more and 0.1 μm or less. Moreover, the pencil hardness of an oligomer prevention layer is F or more and 2H or less.

  By forming the oligomer prevention layer having the above-mentioned specific thickness and pencil hardness, the bending resistance of the light transmissive conductive film laminate can be increased, and the sheet resistance of the light transmissive conductive film laminate is difficult to increase. can do. More specifically, when the thickness of the oligomer prevention layer and the pencil hardness are within the above ranges, the first base film is hardly pulled. If the first base film is difficult to be pulled, cracks are unlikely to occur in the conductive layer, and the flex resistance of the light transmissive conductive film laminate is improved. As a result, even if the light transmissive conductive film laminate is bent, the sheet resistance of the light transmissive conductive film laminate is difficult to increase.

  From the viewpoint of further improving the bending resistance of the light transmissive conductive film laminate and making it difficult to further increase the sheet resistance, the thickness of the oligomer prevention layer is preferably 0.02 μm or more, preferably 0.09 μm or less. .

  The oligomer prevention layer can be composed of an inorganic material or an organic material. From the viewpoint of more surely preventing migration of the oligomer component, it is preferable to use an inorganic oxide such as silicon oxide. Moreover, you may provide about 100 nm release layer formed with the silicone release agent etc. on the surface of the oligomer prevention layer.

  Hereinafter, the present invention will be described in more detail based on specific examples. The present invention is not limited to the following examples.

Example 1
Forming a first hard coat layer;
100 parts by weight of urethane acrylate oligomer as a photocurable monomer, 140 parts by weight of a mixed solvent of toluene and methyl isobutyl ketone (MIBK) as a diluent solvent, 7 parts by weight of Irgacure 194 (manufactured by BASF) as a photoinitiator Were mixed and stirred to prepare a first coating solution.

The first coating solution was applied on the surface of one side of a 50 μm thick PET film and dried. After drying, the resin was cured by irradiating UV light of 200 mJ / cm ^{2 with} a high-pressure mercury lamp to form a first hard coat layer having a thickness of 1.1 μm.

Formation of a second hard coat layer;
100 parts by weight of urethane acrylate oligomer as a photocurable monomer, 140 parts by weight of a mixed solvent of toluene and methyl isobutyl ketone (MIBK) as a diluent solvent, 7 parts by weight of Irgacure 194 (manufactured by BASF) as a photoinitiator Were mixed and stirred to prepare a second coating solution.

The second coating liquid was applied on the surface of the PET film opposite to the first hard coat layer side and dried. After drying, the resin was cured by irradiating UV light of 200 mJ / cm ^{2 with} a high-pressure mercury lamp to form a second hard coat layer having a thickness of 1.2 μm.

Forming an adhesive layer;
By applying a solution of an acrylic pressure-sensitive adhesive (manufactured by Sekisui Chemical Co., Ltd.) on the surface of the second hard coat layer opposite to the PET film, the storage elastic modulus is 1.10 × by heating and drying. A pressure-sensitive adhesive layer of 10 ⁵ Pa was formed. The storage elastic modulus of the pressure-sensitive adhesive layer was measured by dynamic viscoelasticity measurement. In the dynamic viscoelasticity measurement, the temperature dependency was measured using a melt viscoelasticity measuring apparatus (manufactured by TA Instruments Japan, product number “ARES-G2”) under the following conditions.

Temperature increase rate: 3 ° C / min
Frequency: 1Hz
Strain: 3%
Temperature range: -50 ° C to 200 ° C
Parallel plate: 8mmφ
Sample thickness: 2mm

Forming a protective film;
Next, a protective film was prepared in which a silicon oxide layer as an oligomer prevention layer having a thickness of 0.03 μm was formed on the surface of a PET film (thickness: 125 μm) as a base film. This protective film was bonded to the pressure-sensitive adhesive layer from the oligomer prevention layer side.

Forming a conductive layer;
An ITO layer (conductive layer) having a thickness of 18 nm was deposited on the surface of the first hard coat layer. The PET film on which the ITO layer was deposited was heated in an oven at 150 ° C. for 60 minutes. A dry film resist was applied to the obtained film, and exposure and development were performed. Subsequently, the etching, peeling, washing, and drying steps were performed in this order, and the ITO layer was patterned to obtain a light transmissive conductive film laminate.

(Examples 2 to 16 and Comparative Examples 1 to 16)
The first hard coat layer was changed to the first hard coat layer having the thickness and pencil hardness described in Table 1, and the second hard coat layer was changed to the first hard coat layer having the thickness and pencil hardness described in Table 1. Except that the layer was changed to a layer, the oligomer prevention layer was changed to an oligomer prevention layer having the thickness and pencil hardness described in Table 1, and the pressure-sensitive adhesive layer was changed to a pressure-sensitive adhesive layer having a storage modulus shown in Table 1. A light-transmitting conductive film laminate was produced in the same manner as in Example 1.

(Evaluation)
The following evaluation was performed about the light transmissive conductive film laminated body obtained by Examples 1-16 and Comparative Examples 1-16. The results are shown in Table 1 below.

Flex resistance;
About the obtained light-transmitting conductive film laminated body, the bending resistance was evaluated according to the following criteria.

  With the conductive layer facing upward, as shown in FIG. 2, the light transmissive conductive film laminate 1 is wound around a stainless steel rod 11 having a diameter of 11 mm, and a first load 12 of 500 g and a second load of 500 g. Both ends of the light-transmitting conductive film laminate 1 were pulled vertically downward with a load 13, the light-transmitting conductive film laminate 1 was slid, and the resistance value was measured by a four-probe method for each reciprocation. The value obtained by dividing the resistance value after 10 reciprocations by the initial resistance value was defined as the change value.

○: Change value is less than 1.3 ×: Change value is 1.3 or more

  Details and results are shown in Table 1 below.

DESCRIPTION OF SYMBOLS 1 ... Light transmissive conductive film laminated body 2 ... Light transmissive conductive film 3 ... Adhesive layer 4 ... Protective film 5 ... 1st base film 5a ... 1st surface 5b ... 2nd surface 6 ... Conductive layer 7 ... 1st hard coat layer 8 ... 2nd hard coat layer 9 ... 2nd base film 10 ... Oligomer prevention layer 11 ... Rod 12 ... 1st load 13 ... 2nd load

Claims (4)

A light transmissive conductive film having light transmissive and conductive properties;
An adhesive layer laminated on the surface of the light transmissive conductive film;
A protective film laminated on the surface of the pressure-sensitive adhesive layer opposite to the light-transmissive conductive film;
With
The light transmissive conductive film is disposed on a conductive layer, a first hard coat layer disposed on the surface of the conductive layer, and a surface of the first hard coat layer opposite to the conductive layer. And a second hard coat layer disposed on the surface of the first base film opposite to the first hard coat layer, and
The protective film is disposed on the second base film disposed on the opposite side of the pressure-sensitive adhesive layer, on the surface of the second base film, and disposed on the pressure-sensitive adhesive layer side. An oligomer prevention layer,
The thickness of the first hard coat layer is 0.5 μm or more and 3.0 μm or less,
The thickness of the second hard coat layer is 0.5 μm or more and 3.0 μm or less,
The oligomer prevention layer has a thickness of 0.01 μm or more and 0.1 μm or less,
The pencil hardness of the first hard coat layer is 5B or more and 3B or less,
The pencil hardness of the second hard coat layer is 5B or more and 3B or less,
The oligomer hardness of the oligomer prevention layer is F or more and 2H or less,
The light-transmitting conductive film laminate, wherein the pressure-sensitive adhesive layer has a storage elastic modulus at a frequency of 1 Hz and a temperature of 23 ° C. of 4.0 × 10 ⁴ Pa or more and 2.0 × 10 ⁵ Pa or less.   The light-transmitting conductive film laminate according to claim 1, wherein the first hard coat layer has a resin portion and a filler.   The light-transmitting conductive film laminate according to claim 1 or 2, wherein the second hard coat layer has a resin portion and a filler.   The transparent electroconductive film laminated body of any one of Claims 1-3 used for a liquid crystal display device.

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