JP2017065151A - Transparent conductive laminate and touch panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transparent conductive laminate having excellent weather resistance and also having excellent conductivity and transparency.SOLUTION: A transparent conductive laminate is characterized in that on one side of a conductive layer comprising a conductive fibrous filler, a resin layer comprising conductive particles is provided, and the other side of the resin layer, which is opposite to the one side provided with the conductive layer, has a resistance value of 1 Ω/sq. or more and less than 1×10Ω/sq.SELECTED DRAWING: None

Description

The present invention relates to a transparent conductive laminate and a touch panel.

Conventionally, transparent and conductive thin films have been used as transparent electrodes for displays such as liquid crystal displays (LCD) and plasma display panels (PDP), touch panels, and solar cells. Examples of such thin films include: A transparent conductive thin plate in which a conductive film made of indium tin oxide (ITO) or the like is laminated on a glass substrate has been used.
However, since a transparent conductive thin plate using a glass substrate is inferior in flexibility, a vacuum deposition method has recently been used on a base film made of a flexible resin such as polyester (PET) film or polyethylene naphthalate (PEN). A conductive film provided with a conductive film made of ITO or the like by sputtering or sputtering has been mainly used.

However, since the conductive film made of ITO or the like was not flexible, there was a problem that when the conductive film was provided on a base film made of a flexible resin, cracks were likely to occur.
On the other hand, for example, a transparent conductor in which a transparent conductive layer containing metal nanowires is provided on a substrate is known (see, for example, Patent Document 1).
The transparent conductor described in Patent Document 1 is prepared by coating an aqueous dispersion in which metal nanowires are dispersed in a dispersion solvent on a substrate, preferably a hydrophilic polymer layer provided on a base material, and drying. The transparent conductive material produced by forming a transparent conductive layer with the method is in a state where metal nanowires are embedded in the base material or the hydrophilic polymer layer.

However, in such a conventional transparent conductor, in order to ensure sufficient conductive performance, a part of the metal nanowire is exposed from the surface of the transparent conductive layer or a large number of metal nanowires exist near the surface. Therefore, there was a problem that oxidation, halogenation, and sulfidation easily occurred, the surface resistance value fluctuated, and the weather resistance was inferior.

In order to solve such a problem, for example, a method of improving the weather resistance of the transparent conductor by forming an overcoat layer on the surface of the transparent conductive layer is considered.
However, if a thick overcoat layer is provided so that the metal nanowires are not oxidized or sulfided, the surface resistance value of the transparent conductor increases, and special processing is required when incorporating the module into the module, resulting in a significant decrease in yield. When a thin overcoat layer that can sufficiently secure the surface resistance value of the transparent conductive layer is provided, the weather resistance cannot be sufficiently improved.

For this reason, for example, Patent Document 2 discloses a method of providing an overcoat layer in which conductive particles are dispersed on a transparent conductive layer.
However, when maintaining the excellent conductivity of the transparent conductive layer containing metal nanowires even on the surface of the overcoat layer in which the conductive particles are dispersed, a large amount of conductive particles are added to the overcoat layer. Therefore, there is a problem that transparency is inferior.

JP 2010-084173 A Special table 2010-507199

The present invention has been made in view of the above situation, and has an object to provide a transparent conductive laminate having excellent weather resistance and excellent conductivity and transparency, and a touch panel using the transparent conductive laminate. It is what.

In the present invention, a resin layer containing energized particles is provided on one surface of a conductive layer containing a conductive fibrous filler, and the resistance value on the side opposite to the conductive layer side of the resin layer is 1Ω / □ or more and less than 1 × 10 ⁶ Ω / □.

In the transparent conductive laminate of the present invention, the conductive fibrous filler preferably has a fiber diameter of 200 nm or less and a fiber length of 1 μm or more.
The conductive fibrous filler is preferably at least one selected from the group consisting of conductive carbon fibers, metal fibers, and metal-coated synthetic fibers.
Moreover, it is preferable that a part of the said conductive fibrous filler protrudes from the resin layer side surface of the said conductive layer.
Moreover, it is preferable that the thickness of the said electroconductive layer is less than the fiber diameter of the said electroconductive fibrous filler.

It is preferable that the average particle diameter of the energized particles is larger than the thickness of the resin layer.
Moreover, it is preferable that the average particle diameter of the said electricity supply particle exists in the range of 80 to 200% with respect to the thickness of the said resin layer.

Moreover, this invention is also a touchscreen characterized by using the transparent conductive laminated body of this invention mentioned above.
Hereinafter, the present invention will be described in detail.
In the present specification, “resin” is a concept including monomers, oligomers, polymers and the like unless otherwise specified.

As a result of intensive studies in view of the above-mentioned present situation, the present inventors have found that in the transparent conductive laminate having a structure in which a resin layer is provided on the conductive layer, the conductive layer contains a conductive fibrous filler, The present inventors have found that a transparent conductive laminate having excellent weather resistance, electrical conductivity, and transparency can be obtained by making the resin layer contain energized particles, and the present invention has been completed.

The present invention is a transparent conductive laminate in which a resin layer containing energized particles is provided on one surface of a conductive layer containing a conductive fibrous filler.
Here, in the transparent conductive laminate according to the present invention, "transparent" means having excellent light transmission performance, more specifically, the transparent conductive laminate of the present invention is The total light transmittance is 80% or more.
The total light transmittance is a value measured according to JIS K-7361. As a device used for the measurement, a reflection / transmittance meter HM-150 (Murakami Color Research Laboratory) can be mentioned.
Such a transparent conductive laminate of the present invention has a resistance value of 1 Ω / □ or more and less than 1 × 10 ⁶ Ω / □ on the side surface (hereinafter also referred to as surface) of the resin layer opposite to the conductive layer side. . If it is less than 1 Ω / □, the amount of the conductive fibrous filler added becomes too large, and the transparency becomes insufficient. If it is 1 × 10 ⁶ Ω / □ or more, the transparent conductive laminate of the present invention The conductive performance becomes insufficient.
The resistance value on the surface of the resin layer is preferably 10 Ω / □ or more, and preferably less than 1 × 10 ⁴ Ω / □.
In addition, the transparent conductive laminated body provided with the resin layer in which conductive fine particles are dispersed on the above-described conventional transparent conductive layer includes the conductive fine particles in the resin layer to the extent that the resistance value requirement is satisfied. When the conductive fine particles are contained in the resin layer to such an extent that the above-described transparency requirement cannot be satisfied, the above-described resistance value requirement cannot be satisfied.

The transparent conductive laminate of the present invention has excellent resistance as described above, although the resistance value of the surface of the resin layer is in the above range and has excellent conductivity.
Such coexistence of conductivity and transparency can be achieved because the resin layer has a predetermined configuration including conductive particles as described later. Furthermore, by having such a resin layer on the conductive layer, it is possible to suitably prevent the conductive fibrous filler contained in the conductive layer, which will be described later, from being oxidized or sulfided. The porous laminate has excellent weather resistance.

In the transparent conductive laminate of the present invention, the conductive layer contains a conductive fibrous filler.
In the present invention, the conductive layer may contain a binder resin in addition to the conductive fibrous filler. In this case, a part of the conductive fibrous filler is a resin layer of the conductive layer. It is preferable to protrude from the side surface (hereinafter also simply referred to as the surface).
The conductive laminate having such a conductive layer can have a low light haze value and high light transmission performance.
Moreover, by setting it as the structure which has an electroconductive fibrous filler in the said binder resin, the abrasion resistance of the said electroconductive layer will be especially excellent.

The binder resin is not particularly limited, and is preferably, for example, a transparent one. For example, an ionizing radiation curable resin that is a resin curable by ultraviolet rays or electron beams is cured by irradiation with ultraviolet rays or electron beams. Is preferred.
Examples of the ionizing radiation curable resin include compounds having one or more unsaturated bonds such as compounds having functional groups such as acrylates. Examples of the compound having one unsaturated bond include ethyl (meth) acrylate, ethylhexyl (meth) acrylate, styrene, methylstyrene, N-vinylpyrrolidone and the like. Examples of the compound having two or more unsaturated bonds include trimethylolpropane tri (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, and pentaerythritol. Tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) ) Acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, tripentaerythritol octa (meth) acrylate Rate, tetrapentaerythritol deca (meth) acrylate, isocyanuric acid tri (meth) acrylate, isocyanuric acid di (meth) acrylate, polyester tri (meth) acrylate, polyester di (meth) acrylate, bisphenol di (meth) acrylate, diglycerin Polyfunctional compounds such as tetra (meth) acrylate, adamantyl di (meth) acrylate, isoboronyl di (meth) acrylate, dicyclopentane di (meth) acrylate, tricyclodecane di (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate Etc. Among these, pentaerythritol triacrylate (PETA), dipentaerythritol hexaacrylate (DPHA), and pentaerythritol tetraacrylate (PETTA) are preferably used. In the present specification, “(meth) acrylate” refers to methacrylate and acrylate. In the present invention, as the ionizing radiation curable resin, a compound obtained by modifying the above-described compound with PO, EO or the like can also be used.

In addition to the above compounds, relatively low molecular weight polyester resins having unsaturated double bonds, polyether resins, acrylic resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, etc. It can be used as an ionizing radiation curable resin.

The ionizing radiation curable resin is used in combination with a solvent-drying resin (a thermoplastic resin or the like, which is a resin that forms a film only by drying the solvent added to adjust the solid content during coating). You can also. By using the solvent-drying resin in combination, film defects on the coating surface of the coating liquid can be effectively prevented when the conductive layer is formed.
The solvent-drying resin that can be used in combination with the ionizing radiation curable resin is not particularly limited, and a thermoplastic resin can be generally used.
The thermoplastic resin is not particularly limited. For example, a styrene resin, a (meth) acrylic resin, a vinyl acetate resin, a vinyl ether resin, a halogen-containing resin, an alicyclic olefin resin, a polycarbonate resin, or a polyester resin. Examples thereof include resins, polyamide-based resins, cellulose derivatives, silicone-based resins, rubbers, and elastomers. The thermoplastic resin is preferably amorphous and soluble in an organic solvent (particularly a common solvent capable of dissolving a plurality of polymers and curable compounds). In particular, from the viewpoint of transparency and weather resistance, styrene resins, (meth) acrylic resins, alicyclic olefin resins, polyester resins, cellulose derivatives (cellulose esters, etc.) and the like are preferable.

The conductive layer may contain a thermosetting resin.
The thermosetting resin is not particularly limited. For example, phenol resin, urea resin, diallyl phthalate resin, melamine resin, guanamine resin, unsaturated polyester resin, polyurethane resin, epoxy resin, aminoalkyd resin, melamine-urea cocondensation Examples thereof include resins, silicon resins, polysiloxane resins, and the like.

The conductive layer containing the binder resin is formed by, for example, applying the conductive fibrous filler, the solvent, and the composition for the conductive layer containing the monomer component of the binder resin on the base film described later. The coating film formed by drying can be formed by curing by ionizing radiation irradiation or the like.

Examples of the solvent contained in the conductive layer composition include alcohol (eg, methanol, ethanol, propanol, isopropanol, n-butanol, s-butanol, t-butanol, benzyl alcohol, PGME, ethylene glycol), ketone (Acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), ethers (dioxane, tetrahydrofuran, etc.), aliphatic hydrocarbons (hexane, etc.), alicyclic hydrocarbons (cyclohexane, etc.), aromatic hydrocarbons ( Toluene, xylene, etc.), halogenated carbons (dichloromethane, dichloroethane, etc.), esters (methyl acetate, ethyl acetate, butyl acetate, etc.), cellosolves (methyl cellosolve, ethyl cellosolve, etc.), cellosolve acetates, sulfoxide (Dimethyl sulfoxide), amides (dimethylformamide, dimethylacetamide, etc.) and the like can be exemplified, or a mixture thereof.

The conductive layer composition preferably further contains a photopolymerization initiator.
The photopolymerization initiator is not particularly limited, and known ones can be used. Specific examples include, for example, acetophenones, benzophenones, Michler benzoylbenzoate, α-amyloxime ester, thioxanthones, propio Examples include phenones, benzyls, benzoins, and acylphosphine oxides. In addition, it is preferable to use a mixture of photosensitizers, and specific examples thereof include n-butylamine, triethylamine, poly-n-butylphosphine, and the like.

As the photopolymerization initiator, when the resin component contained in the conductive layer composition is a resin system having a radical polymerizable unsaturated group, acetophenones, benzophenones, thioxanthones, benzoin, benzoin methyl ether, etc. Are preferably used alone or in combination. When the resin component is a resin system having a cationic polymerizable functional group, examples of the photopolymerization initiator include aromatic diazonium salts, aromatic sulfonium salts, aromatic iodonium salts, metallocene compounds, benzoin sulfonate esters, and the like. Are preferably used alone or as a mixture.

It is preferable that content of the said photoinitiator in the said composition for conductive layers is 0.5-10.0 mass parts with respect to 100 mass parts of said resin components. If the amount is less than 0.5 parts by mass, the hardness of the conductive layer to be formed may be insufficient, and if it exceeds 10.0 parts by mass, there is a possibility that the curing may be hindered. Absent.

Although it does not specifically limit as a content rate (solid content) of the raw material in the said composition for electroconductive layers, Usually, it is preferable to set it as 5-70 mass%, especially 25-60 mass%.

According to the purpose of increasing the hardness of the conductive layer, suppressing curing shrinkage, controlling the refractive index, etc., a conventionally known dispersant, surfactant, antistatic agent, Silane coupling agent, thickener, anti-coloring agent, coloring agent (pigment, dye), antifoaming agent, leveling agent, flame retardant, UV absorber, adhesion-imparting agent, polymerization inhibitor, antioxidant, surface modification An agent or the like may be added.
As the leveling agent, for example, silicone oil, fluorine-based surfactant and the like are preferable because the curable resin layer is prevented from having a Benard cell structure. When a resin composition containing a solvent is applied and dried, a surface tension difference or the like is generated between the coating film surface and the inner surface in the coating film, thereby causing many convections in the coating film. The structure generated by this convection is called a Benard cell structure, and causes problems such as the skin and coating defects in the conductive layer to be formed.

The method for preparing the composition for a conductive layer is not particularly limited as long as each component can be mixed uniformly. For example, the composition can be performed using a known apparatus such as a paint shaker, a bead mill, a kneader, or a mixer.

The material constituting the base film is not particularly limited. For example, polyester resin, acetate resin, polyethersulfone resin, polycarbonate resin, polyamide resin, polyimide resin, polyolefin resin, (meth) Examples include acrylic resins, polyvinyl chloride resins, polyvinylidene chloride resins, polystyrene resins, polyvinyl alcohol resins, polyarylate resins, polyphenylene sulfide resins, and the like. Of these, polyester resins, polycarbonate resins, and polyolefin resins are preferably used.

In addition, as said base film, the amorphous olefin polymer (Cyclo-Olefin-Polymer: COP) film which has alicyclic structure is mentioned. This is a base material in which a norbornene polymer, a monocyclic olefin polymer, a cyclic conjugated diene polymer, a vinyl alicyclic hydrocarbon polymer, and the like are used. Zeonoa (norbornene-based resin), Sumitrite FS-1700 manufactured by Sumitomo Bakelite, Arton (modified norbornene-based resin) manufactured by JSR, Appel (cyclic olefin copolymer) manufactured by Mitsui Chemicals, Topas (cyclic) manufactured by Ticona Olefin copolymer), Optretz OZ-1000 series (alicyclic acrylic resin) manufactured by Hitachi Chemical Co., Ltd., and the like.
Further, the FV series (low birefringence, low photoelastic modulus film) manufactured by Asahi Kasei Chemicals is also preferable as an alternative base material for triacetylcellulose.

The thickness of the base film is preferably 1 to 100 μm. When the thickness is less than 1 μm, the mechanical strength of the transferred material may be insufficient. When the thickness exceeds 100 μm, the flexibility of the conductive film may be insufficient. The more preferable lower limit of the thickness of the substrate film is 20 μm, the more preferable upper limit is 80 μm, the still more preferable lower limit is 40 μm, and the still more preferable upper limit is 60 μm.

The substrate film may have been subjected to etching treatment or undercoating treatment such as sputtering, corona discharge, ultraviolet irradiation, electron beam irradiation, chemical conversion, oxidation, etc. on the surface in advance. By performing these treatments in advance, the adhesion with the conductive layer formed on the substrate film can be improved. Moreover, before forming a conductive layer, the base film surface may be dust-removed and cleaned by solvent washing | cleaning, ultrasonic washing | cleaning, etc. as needed.

The method for applying the conductive layer composition on the base film is not particularly limited, and examples thereof include spin coating, dipping, spraying, die coating, bar coating, roll coater, meniscus coater, Well-known methods, such as a flexographic printing method, a screen printing method, a pea coater method, can be mentioned.

In addition, as a method of irradiating ionizing radiation when curing the coating film after drying, for example, a light source such as an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc lamp, a black light fluorescent lamp, or a metal halide lamp is used. A method is mentioned.
Moreover, as a wavelength of an ultraviolet-ray, the wavelength range of 190-380 nm can be used. Specific examples of the electron beam source include various electron beam accelerators such as a cockcroft-wald type, a bandegraft type, a resonant transformer type, an insulated core transformer type, a linear type, a dynamitron type, and a high frequency type.

Moreover, when the said conductive layer contains the said binder resin, the thickness of the hardened | cured material of the said binder resin (henceforth a binder resin layer) in this conductive layer is less than the fiber diameter of the said conductive fibrous filler. It is preferable. When the thickness of the binder resin layer is equal to or larger than the fiber diameter of the conductive fibrous filler, the amount of binder resin entering the contact of the conductive fibrous filler increases, and the conduction of the conductive layer deteriorates, and the target resistance The value may not be obtained.
Specifically, the thickness of the binder resin layer is preferably 200 nm or less. When the thickness of the binder resin layer exceeds 200 nm, it is necessary to increase the fiber diameter of the conductive fibrous filler beyond a suitable range described later, so that the haze of the conductive laminate rises and the total light transmission is achieved. The rate may decrease and is optically unsuitable. The thickness of the binder resin layer is more preferably 50 nm or less, and further preferably 30 nm or less.
In addition, the thickness of the binder resin layer is, for example, an arbitrary 10 locations where the thickness was measured by observing the cross section of the conductive layer at 1000 to 500,000 times using an electron microscope such as SEM, STEM, or TEM. It can be obtained as an average value.
On the other hand, when the conductive layer does not contain the binder resin, since the conductive layer is composed of a conductive fibrous filler, the cross section in the thickness direction includes a portion where the conductive fibrous filler exists and A place that does not exist is observed. Where the conductive fibrous filler is present, there can be a place where the conductive fibrous filler is laminated alone and a place where two or more of the conductive fibrous fillers are laminated, but there are places where there is no conductive fibrous filler ( That is, when the thickness of the conductive layer is measured according to the above definition, the thickness of the conductive layer that does not contain the binder resin is usually the fiber of the conductive fibrous filler. It becomes less than the diameter.

The conductive fibrous filler preferably has a fiber diameter of 200 nm or less and a fiber length of 1 μm or more.
When the fiber diameter exceeds 200 nm, the transparency of the produced transparent conductive laminate may be insufficient. The preferable lower limit of the fiber diameter of the conductive fibrous filler is 10 nm from the viewpoint of the conductivity of the conductive layer, and the more preferable range of the fiber diameter is 15 to 180 nm.
Moreover, when the fiber length of the conductive fibrous filler is less than 1 μm, a conductive layer having sufficient conductive performance may not be formed, and aggregation may occur, resulting in an increase in haze value or a decrease in light transmission performance. Therefore, the upper limit of the fiber length is preferably 500 μm, the more preferable range of the fiber length is 3 to 300 μm, and the further preferable range is 10 to 30 μm.
The fiber diameter and fiber length of the conductive fibrous filler are, for example, the fiber diameter and fiber length of the conductive fibrous filler at 1000 to 500,000 times using an electron microscope such as SEM, STEM, or TEM. It can obtain | require as an average value of 10 places measured.

Such a conductive fibrous filler is preferably at least one selected from the group consisting of conductive carbon fibers, metal fibers, and metal-coated synthetic fibers.
Examples of the conductive carbon fiber include vapor grown carbon fiber (VGCF), carbon nanotube, wire cup, and wire wall. These conductive carbon fibers can use 1 type (s) or 2 or more types.

As said metal fiber, the fiber produced by the wire-drawing method or the cutting method which extends stainless steel, iron, gold | metal | money, silver, aluminum, nickel, titanium etc. thinly and long can be used, for example. Such metal fiber can use 1 type (s) or 2 or more types.

Examples of the metal-coated synthetic fibers include fibers obtained by coating acrylic fibers with gold, silver, aluminum, nickel, titanium, and the like. One or more kinds of such metal-coated synthetic fibers can be used.

When the said conductive layer contains the said binder resin, as content of the said conductive fibrous filler, it is preferable that it is 20-3000 mass parts with respect to 100 mass parts of said binder resins, for example. If the amount is less than 20 parts by mass, a conductive layer having sufficient conductivity may not be formed. If the amount exceeds 3000 parts by mass, the transparency of the transparent conductive laminate of the present invention may be insufficient. . Further, the amount of the binder resin that enters the contact of the conductive fibrous filler is increased, so that the conductivity of the conductive layer is deteriorated, and the transparent conductive laminate of the present invention may not obtain the target resistance value. The minimum with more preferable content of the said conductive fibrous filler is 50 mass parts, and a more preferable upper limit is 1000 mass parts.

When the said conductive layer contains binder resin, a part of said conductive fibrous filler may protrude from the surface (henceforth the surface) on the side of the resin layer mentioned later of the said conductive layer.
When the transparent conductive laminate of the present invention is produced by a transfer method to be described later, the side of the conductive layer provided on the release film is laminated so that the conductive layer and the resin layer face each other and pressed. In addition, if the conductive fibrous filler protrudes from the surface of the conductive layer (that is, the surface pressed against the resin layer of the conductive layer), the protruding conductive fibrous filler is embedded in the resin layer. As a result, the conductive performance of the obtained transparent conductive laminate is excellent, and further, the barrier property of the conductive layer is improved and the weather resistance is excellent.

When the said conductive layer contains binder resin, it is preferable that a part of said conductive fibrous filler protrudes in the range of 5-600 nm from the surface of the said conductive layer. In this invention, it is preferable that the perpendicular distance from the flat location where the conductive fibrous filler on the surface of the said conductive layer does not protrude to the front-end | tip of the protruding conductive fibrous filler is 600 nm or less. When the vertical distance exceeds 600 nm, the conductive fibrous filler may fall off from the conductive layer. A more preferable upper limit of the vertical distance is 200 nm.
Note that the vertical distance of the conductive fibrous filler protruding from the surface of the conductive layer is, for example, 1000 to 500,000 times using an electron microscope such as SEM, STEM, or TEM, and the surface of the conductive layer is observed. And the vertical distance from the flat portion of the surface of the conductive layer to the tip of the conductive fibrous filler measured can be obtained as an average value of 10 locations.

As a method for producing the transparent conductive laminate of the present invention, for example, a method including a transfer step of transferring the conductive layer to a resin layer using a transfer film having at least the conductive layer on a release film, After forming a conductive layer on the base film using the conductive layer composition described above, a method of forming a resin layer on the conductive layer using a resin layer composition described later, etc. Can be mentioned.

In the transparent conductive laminate of the present invention, the resin layer contains energized particles.
The energized particles are particles that play a role of imparting conductivity to the transparent conductive laminate of the present invention by imparting conductivity to the surface of the resin layer.
In order to fulfill the above role, the energized particles are in contact with the conductive fibrous filler of the conductive layer described above on the conductive layer side of the resin layer, and are exposed on the side surface opposite to the conductive layer side of the resin layer. Thus, it is preferably contained in the resin layer.

The conductive particles preferably have an average particle size larger than the thickness of the resin layer. When the average particle diameter of the energized particles is equal to or less than the thickness of the resin layer, the surface conductivity of the resin layer may be insufficient.
In addition, the said electrically-conductive particle can be contained in the state protruded from the surface of the said resin layer because the average particle diameter of the said electrically-conductive particle is larger than the thickness of the said resin layer.
Especially, it is preferable that the said electricity supply particle is contained in the said resin layer in the state protruded from both surfaces of the said resin layer. By containing the energized particles in the resin layer in this way, the contact with the conductive fibrous filler in the conductive layer becomes good, while the conductivity of the surface of the resin layer becomes good.
As a method for causing the conductive particles to protrude on both surfaces of the resin layer, for example, the conductive layer is formed by the transfer method described above on the resin layer containing the conductive particles having an average particle diameter larger than the thickness of the resin layer. A method is mentioned.

Moreover, it is preferable that the said electrically-conductive particle has an average particle diameter in the range of 80 to 200% with respect to the thickness of the said resin layer. If it is less than 80%, the conductivity of the surface of the resin layer is insufficient, and problems such as a decrease in transmittance may occur by increasing the amount of addition to compensate for it. If it exceeds 200%, the energized particles may fall off the resin layer. The more preferable lower limit of the ratio of the average particle diameter of the energized particles to the thickness of the resin layer is 101%, and the more preferable upper limit is 150%.
The average particle diameter of the energized particles is an average value of the particle diameters of 10 energized particles measured by observing the resin layer from the surface side with a microscope, and the thickness of the resin layer is the value of the present invention. When the conductive fibrous filler protrudes in the region where the conductive particles do not exist when the transparent conductive laminate is observed with a cross-sectional microscope, the distance from the protruding tip to the surface of the conductive layer is set as follows. It is the average value measured at any 10 locations.

In the transparent conductive laminate of the present invention, the conductive particles are particularly fine particles made of a conductive material capable of conducting the conductive fibrous filler in the conductive layer and the surface of the resin layer. Without being limited, known fine particles can be used. Especially, since it is excellent in electroconductivity and can electrically connect the conductive fibrous filler in the conductive layer and the surface of the resin layer, the conductive particles react with the atmosphere components used and have conductivity. In order to suppress the decrease, it is preferable to use stable and highly conductive metal particles or resin beads surface-treated with a metal having the same characteristics. In particular, beads treated with gold and nickel are electrically conductive. It is suitable because it has a high reactivity and the reactivity with the atmosphere is low.
The content of the conductive particles in the resin layer is appropriately adjusted within the range in which the above-described resistance value can be obtained, and is preferably 0.01 to 5.00% by mass. If it is less than 0.01% by mass, the weather resistance of the transparent conductive laminate of the present invention may be insufficient, and if it exceeds 5.00% by mass, problems such as a decrease in transmittance may occur. There is. The minimum with more preferable content of the said electrically-conductive particle is 0.03 mass%, and a more preferable upper limit is 1.00 mass%.

As a resin component which comprises the said resin layer, it is preferable that it is an insulating material, For example, the material similar to the binder resin of the electroconductive layer mentioned above is mentioned.
Moreover, the said resin layer can be formed using the composition for resin layers similar to the composition for conductive layers mentioned above except containing the said electricity supply particle | grains.

The thickness of the resin layer is preferably 0.2 to 10 μm. When it is less than 0.2 μm, the weather resistance of the transparent conductive laminate of the present invention may be insufficient, and when it exceeds 10 μm, curling may occur. A more preferable lower limit of the thickness of the resin layer is 0.5 μm, a more preferable upper limit is 7 μm, a still more preferable lower limit is 1 μm, and a further preferable upper limit is 6 μm.

When manufacturing the transparent conductive laminated body of this invention by the method which has the said transfer process, the transfer film which has an electroconductive layer at least on a release film is used.
The release film of the transfer film is not particularly limited, and examples thereof include conventionally known ones such as an untreated polyethylene terephthalate (PET) film.
As a method for transferring the conductive layer to the resin layer using the transfer film, the transfer film described above is laminated so that the side of the conductive layer is on the resin layer side, pressed, and then the release film is peeled off. The method of letting it be mentioned.

As described above, the transparent conductive laminate of the present invention thus produced has a total light transmittance of 80% or more, preferably 88% or more, more preferably 89% or more. In addition, the transparent conductive laminate of the present invention preferably has a haze value of 5% or less. If the haze value exceeds 5%, the optical performance of the transparent conductive laminate of the present invention may be insufficient, and the transparency may be insufficient. A preferable upper limit of the haze value is 1.5%, and a more preferable upper limit is 1.2%.
In addition, the said haze value is the sum total of an internal haze value and a surface haze value, and is a value measured according to JIS K-7136. As a device used for the measurement, a reflection / transmittance meter HM-150 (Murakami Color Research Laboratory) can be mentioned.
Moreover, it is preferable that the haze value derived from the said conductive fibrous filler is 4% or less, More preferably, it is 1.5% or less, More preferably, it is 0.8% or less. The haze value derived from the conductive fibrous filler is a highly transparent adhesive transfer tape (Optically Clear Adhesive Tape :) on both surfaces of the same film as the conductive layer described above except that the conductive fibrous filler is not included. Sample 1 prepared by attaching HCA to sample 0 prepared by bonding to glass using OCA) and bonding the glass to both surfaces of the above-described conductive layer containing conductive fibrous filler using OCA. The haze measured for H was H1, and the haze determined by H1-H0 was the haze value derived from the conductive fibrous filler.
The glass used for measuring the haze value derived from the conductive fibrous filler is 1.1 mm thick soda glass, and OCA is a sample using 3M OCA, 8146-2 (tape thickness 50 μm). Use.

The transparent conductive laminate of the present invention is excellent in weather resistance. For example, when the transparent conductive laminate of the present invention is subjected to a weather resistance test under the conditions of a temperature of 60 ° C. and a humidity of 95% or a temperature of 85 ° C., the change rate of the resistance value on the surface of the resin layer is the weather resistance. It is preferable that it is −10% to + 10% before and after the test.

The transparent conductive laminate of the present invention can be used as a transparent electrode for displays such as liquid crystal displays (LCD) and plasma display panels (PDP), touch panels and solar cells. A touch panel using such a transparent conductive laminate of the present invention is also one aspect of the present invention.

Since the transparent conductive laminate of the present invention has the above-described configuration, it has extremely high weather resistance, and has conductivity and transparency. For this reason, the transparent conductive laminate of the present invention can be suitably used for displays such as liquid crystal displays (LCDs) and plasma display panels (PDPs), and transparent electrodes such as touch panels and solar cells. Is particularly suitable.

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples and comparative examples.
In the text, “part” or “%” is based on mass unless otherwise specified.

Example 1
(Preparation of transparent conductive laminate)
As the base film, a polyester film having a thickness of 50 [mu] m (A4100, Toyobo Co., Ltd.) was used, the untreated surface of the polyester film, coating the following conductive layer composition was coated so as to be 10 mg / m ² After drying at 70 ° C. for 1 minute, a conductive layer is formed, on which the following resin layer composition is applied so that the thickness after drying is 4 μm to form a coating film at 70 ° C. After drying for 1 minute, UV irradiation was performed at UV 350 mJ to form a resin layer and a transparent conductive laminate.

(Preparation of composition for conductive layer)
Using nucleation process and particle growth as shown below using ethylene glycol (EG) as the reducing agent and polyvinylpyrrolidone (PVP: PVP: average molecular weight 1.3 million, manufactured by Aldrich) as the shape control agent and protective colloid agent, respectively. The process was separated and particle formation was performed to obtain a conductive fibrous filler. A conductive layer composition was prepared using the obtained conductive fibrous filler.

(Nucleation process)
While stirring 100 mL of the EG solution maintained at 160 ° C. in the reaction vessel, 2.0 mL of an EG solution of silver nitrate (silver nitrate concentration: 1.0 mol / L) was added at a constant flow rate over 1 minute.
Thereafter, the silver ions were reduced while being held at 160 ° C. for 10 minutes to form silver core particles. The reaction solution exhibited a yellow color derived from surface plasmon absorption of nano-sized silver fine particles, and it was confirmed that silver ions were reduced to form silver fine particles (nuclear particles).
Subsequently, 10.0 mL of an EG solution of PVP (PVP concentration: 3.0 × 10 ⁻¹ mol / L) was added at a constant flow rate over 10 minutes.

(Particle growth process)
The reaction liquid containing the core particles after the nucleation step is held at 160 ° C. with stirring, 100 mL of an EG solution of silver nitrate (silver nitrate concentration: 1.0 × 10 ⁻¹ mol / L), and PVP 100 mL of EG solution (PVP concentration: 3.0 × 10 ⁻¹ mol / L) was added over 120 minutes at a constant flow rate using the double jet method.
In this particle growth process, the reaction solution was collected every 30 minutes and confirmed with an electron microscope. As a result, the core particles formed in the nucleation process grew into a wire-like form over time. Formation of new fine particles in the process was not observed. About the finally obtained conductive fibrous filler (silver nanowire), an electron micrograph is taken and the major axis direction and the minor axis direction particle size of 300 conductive fibrous filler images are measured to perform arithmetic. The average was calculated. The average particle size in the minor axis direction was 100 nm, and the average length in the major axis direction was 40 μm.

(Demineralized water washing process)
After cooling the reaction solution after completing the particle formation step to room temperature, it was subjected to a desalted water washing treatment using an ultrafiltration membrane having a fractional molecular weight of 0.2 μm, and the solvent was replaced with ethanol. Finally, the liquid volume was concentrated to 100 mL to prepare an EtOH dispersion of conductive fibrous filler.

A dilution solvent was added to the obtained silver nanowire EtOH dispersion to prepare a composition for a conductive layer having a silver nanowire concentration of 0.1% by mass. The dilution solvent was 70% by mass IPA and 30% by mass cyclohexanone.

(Adjustment of resin layer composition)
KAYARAD PET-30 (pentaerythritol triacrylate / pentaerythritol tetraacrylate mixture, manufactured by Nippon Kayaku Co., Ltd.) 30% by mass
Irgacure 184 (BASF) 1.5% by mass
MEK 50% by mass
Cyclohexanone 18.45% by mass
Energized particles Bright 20GNR-4.6EH Nippon Chemical Industry Co., Ltd. 0.05% by mass

(Example 2)
A transparent conductive laminate was obtained in the same manner as in Example 1 except that in the production of the transparent conductive laminate, the coating amount of the composition for the conductive layer was changed to 12 mg / m ² .

(Example 3)
In producing the transparent conductive laminate, a transparent conductive laminate was obtained in the same manner as in Example 1 except that the coating amount of the composition for the conductive layer was changed to 15 mg / m ² .

Example 4
A transparent conductive laminate was obtained in the same manner as in Example 1 except that in the production of the transparent conductive laminate, the coating amount of the composition for the conductive layer was changed to 25 mg / m ² .

(Example 5)
A transparent conductive laminate was obtained in the same manner as in Example 1 except that in the production of the transparent conductive laminate, the coating amount of the composition for the conductive layer was changed to 50 mg / m ² .

(Comparative Example 1)
In producing the transparent conductive laminate, a transparent conductive laminate was obtained in the same manner as in Example 1, except that the resin layer composition was changed to the following composition.
(Adjustment of resin layer composition)
KAYARAD PET-30 (pentaerythritol triacrylate / pentaerythritol tetraacrylate mixture, manufactured by Nippon Kayaku Co., Ltd.) 30% by mass
Irgacure 184 (BASF) 1.5% by mass
MEK 50% by mass
Cyclohexanone 18.5% by mass

(Comparative Example 2)
In the production of the transparent conductive laminate, a transparent conductive laminate was obtained in the same manner as in Example 1 except that the thickness of the resin layer composition after drying was changed to 6.5 μm.

(Comparative Example 3)
Using a 50 μm thick polyester film (A4100, manufactured by Toyobo Co., Ltd.), the same resin layer composition as in Example 1 was applied to the untreated surface of the polyester film so that the thickness after drying was 4 μm. After drying at 70 ° C. for 1 minute, UV irradiation was performed at 350 mJ to form a resin layer and a transparent conductive laminate was prepared.

(Reference Example 1)
In the production of the transparent conductive laminate, a transparent conductive laminate was obtained in the same manner as in Comparative Example 1 except that the thickness after drying of the resin layer composition was changed to 100 nm.

(Reference Example 2)
A transparent conductive laminate was obtained in the same manner as in Comparative Example 3 except that the resin layer composition was changed to the following composition in the production of the transparent conductive laminate.

(Adjustment of resin layer composition)
KAYARAD PET-30 (Pentaerythritol triacrylate / pentaerythritol tetraacrylate mixture, manufactured by Nippon Kayaku Co., Ltd.) 29% by mass
Irgacure 184 (BASF) 1.5% by mass
MEK 50% by mass
Cyclohexanone 18.5% by mass
Energized particles Bright 20GNR-4.6EH Nippon Chemical Industry Co., Ltd. 1.0% by mass

The following evaluation was performed about the electroconductive film obtained by the Example, the comparative example, and the reference example. The results are shown in Table 1.

(Total light transmittance)
The total light transmittance of the conductive film was measured by a method based on JIS K7105 using a haze meter (HM150) manufactured by Murakami Color Research Laboratory.

(Haze)
The haze of the conductive film was measured by a method based on JIS K7105 using a haze meter (HM150) manufactured by Murakami Color Research Laboratory.

(Heid derived from conductive fibrous filler)
The haze measured by bonding both surfaces of the transparent conductive laminate not containing the conductive fibrous filler prepared in Comparative Example 5 to the glass using OCA was H0, and both sides of the transparent conductive laminate prepared by others were OCA. The haze measured by bonding to a glass using H1 was H1, and the haze determined by H1-H0 was Haze H2 derived from the conductive fibrous filler.
At this time, a glass sample was prepared using 1.1 mm thick soda glass, and OCA using OCA8146-2 manufactured by 3M.

(Contact resistance value)
In accordance with JIS K7194: 1994 (resistivity test method by 4-probe method of conductive plastics), using a Lorester GP (MCP-T610 type) manufactured by Mitsubishi Chemical Corporation, the conductive layer of each transparent conductive laminate The resistance value on the side was measured.

(Non-contact resistance value)
The resistance value on the conductive layer side of each transparent conductive laminate was measured using a non-destructive resistance measuring instrument (EC-80P) manufactured by NAPSON.

(Continuity test)
Each transparent conductive laminate is cut to a length of 5 cm × 10 cm, and silver paste is applied to the outermost surface of the resin layer at both ends on the short side with a width of 2 mm × length of 5 cm and a thickness of 100 to 120 μm, followed by natural drying for 1 hour. An evaluation sample was prepared. A terminal of a tester was applied to the silver paste portion to confirm whether conduction was obtained from the outermost surface of the resin layer. In addition, Fujikura Kasei Co., Ltd. make and model number D-550 were used for the silver paste.

(Weather resistance test)
Each transparent conductive laminate was cut to a size of 10 cm × 10 cm, and a sample was prepared by bonding the surface of the base film opposite to the surface including the conductive layer and glass. After measuring the non-contact resistance value of each sample, a storage test was performed by leaving it in an 85 ° C. dry environment and 65 ° C. and 90% environment for 500 hours, and then the non-contact resistance value was measured again. Resistance resistance increase rate after storage test = (Non-contact resistance value after test) / (Non-contact resistance value before test) / Weather resistance test to calculate the increase rate of non-contact resistance value before and after the test It was.

As shown in Table 1, the transparent conductive laminates according to the examples had excellent weather resistance and excellent conductivity and transparency.
On the other hand, since the transparent conductive laminate according to Comparative Example 1 did not contain energized particles in the resin layer, and the transparent conductive laminate according to Comparative Example 2 had a thick resin layer, the Comparative Example The transparent conductive laminate according to No. 3 was inferior in conductivity because no conductive layer was provided.
In addition, the transparent conductive laminate according to Reference Example 1 was inferior in weather resistance because the thickness of the resin layer was thin, and the transparent conductive laminate according to Reference Example 2 was thick in the resin layer, The electroconductivity was excellent because the content of the energized particles was large, but the total light transmittance was low and the transparency was poor.

The transparent conductive laminate of the present invention is excellent in weather resistance, conductivity and transparency, and is transparent in displays such as liquid crystal displays (LCD) and plasma display panels (PDP), touch panels and solar cells. It can be suitably used for an electrode, particularly for a transparent electrode of a touch panel.

Claims (8)

On one surface of the conductive layer containing the conductive fibrous filler, a resin layer containing energized particles is provided,
A transparent conductive laminate, wherein a resistance value of the resin layer on a side surface opposite to the conductive layer side is 1 Ω / □ or more and less than 1 × 10 ⁶ Ω / □. The transparent conductive laminate according to claim 1, wherein the conductive fibrous filler has a fiber diameter of 200 nm or less and a fiber length of 1 μm or more. The transparent conductive laminate according to claim 1, wherein the conductive fibrous filler is at least one selected from the group consisting of conductive carbon fibers, metal fibers, and metal-coated synthetic fibers. 4. The transparent conductive laminate according to claim 1, wherein a part of the conductive fibrous filler protrudes from a surface of the conductive layer on the resin layer side. The transparent conductive laminate according to claim 1, 2, 3, or 4, wherein the thickness of the conductive layer is less than the fiber diameter of the conductive fibrous filler. The transparent conductive laminate according to claim 1, 2, 3, 4 or 5, wherein the average particle diameter of the energized particles is larger than the thickness of the resin layer. The transparent conductive laminate according to claim 1, 2, 3, 4, 5 or 6, wherein the average particle diameter of the energized particles is in the range of 80 to 200% with respect to the thickness of the resin layer. A touch panel comprising the transparent conductive laminate according to claim 1, 2, 3, 4, 5, 6 or 7.