JP2019031041A - Conductive film for transfer - Google Patents

Abstract

To provide a conductive film for transfer making it possible to reduce hologramlike poor appearance.SOLUTION: A conductive film for transfer 10 includes a temporary support 11, a resin layer 12 disposed peelably from the temporary support 11, and a conductive layer 13 directly disposed on the resin layer 12. The conductive layer 13 is composed of a metal oxide. A 50 nm depth hardness of the resin layer according to nanoindentation method is 0.3 GPa or more, preferably 4 GPa or more. The resin layer 12 has a thickness of 1-20 μm.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a conductive film for transfer.

  Conventionally, as an electrode for touch sensors used in mobile devices, electromagnetic shielding, etc., a substrate such as a transparent resin film (for example, PET film, cycloolefin film), etc., an indium-tin composite oxide layer (ITO layer), etc. A transparent conductive film having a metal oxide layer (conductive layer) formed thereon is often used.

  On the other hand, in recent years, with the advent of wearable devices, foldable devices, etc., there has been a demand for transparent conductive films that are more flexible and have high bending resistance. As a means for improving the bending resistance, a means of reducing the stress applied to the conductive layer by reducing the thickness of the base material can be considered. However, from the viewpoint of handling and the like, there is a limit to the thin film of the transparent resin film constituting the base material, and the limit thickness of the transparent resin film is a barrier for improving bending resistance. As another means of improving bending resistance, a transparent conductive film having a conductive layer composed of a conductive polymer, metal nanowires, etc., instead of a metal oxide layer that is prone to cracking has been studied. It has problems in terms of transparency and transparency, and has not yet been fully introduced.

Japanese Patent No. 4893867

  The inventors of the present invention have found that the above problem can be solved by using a conductive film for transfer. This transfer conductive film is configured by forming a conductive layer on a resin layer formed on a temporary support by a method such as sputtering. If this conductive film for transfer is used, a laminate including a conductive layer can be transferred from a temporary support to an optical member or the like, and an optical laminate having no rigid substrate can be provided.

  Bending resistance can be improved by using a transfer conductive film, while an optical laminate (for example, a touch sensor; an image display device including a touch sensor) formed using a transfer conductive film has a hologram-like shape. A new problem has arisen that poor appearance (rainbow spots, striped patterns) tends to occur. Such an appearance defect is considered to occur as a result of the resin layer contracting when a conductive layer is formed on the resin layer (for example, during sputtering).

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a conductive film for transfer that can suppress a hologram-like appearance defect.

The transfer conductive film of the present invention comprises a temporary support, a resin layer provided so as to be peelable from the temporary support, and a conductive layer disposed directly on the resin layer. The resin layer is made of an oxide, and the resin layer has a 50 nm depth hardness by nanoindentation method of 0.3 GPa or more.
In one embodiment, the thickness of the resin layer is 1 μm to 20 μm.
In one embodiment, the 100 nm depth hardness by the nanoindentation method of the said resin layer is 0.2 GPa or more.
In one embodiment, the 50 nm depth elastic modulus by the nanoindentation method of the said resin layer is 4 GPa or more.
In one embodiment, the 100 nm depth elastic modulus by the nanoindentation method of the said resin layer is 4 GPa or more.
In one embodiment, the metal oxide is an indium-tin composite oxide.
In one embodiment, the metal oxide is a crystallized metal oxide.
In one embodiment, the conductive layer is patterned.
In one embodiment, the conductive film for transfer further includes a liquid crystal layer disposed between the resin layer and the temporary support.
According to another aspect of the present invention, an optical laminate is provided. The optical laminate includes an optical member, an adhesive layer, the conductive layer, and the resin layer, and the conductive layer is directly laminated on the liquid crystal layer.
According to yet another aspect of the invention, a touch device is provided. This touch sensor includes the optical laminated body.

  The conductive film for transfer of the present invention has a temporary support, a resin layer, and a conductive layer in this order. If the conductive film for transfer having such a configuration is used, a laminate composed of a liquid crystal layer and a conductive layer can be transferred to an optical member to form an optical laminate. Since the obtained optical layered body does not include a base material (a base material necessary for forming a conductive layer), it has excellent bending resistance. Moreover, since the electroconductive layer is comprised from the metal oxide, the electroconductive film for transfer of this invention is excellent in electroconductivity and light transmittance. Furthermore, in the optical laminate formed using the transfer conductive film of the present invention, a hologram-like appearance defect is prevented.

It is a schematic sectional drawing of the electroconductive film for transcription | transfer by one Embodiment of this invention. It is a schematic sectional drawing of the optical laminated body by one Embodiment of this invention. It is a schematic sectional drawing of the optical laminated body by another embodiment of this invention. It is a schematic sectional drawing of the optical laminated body by another embodiment of this invention. It is a photograph figure which shows the external appearance evaluation result of an Example and a comparative example.

(Definition of terms and symbols)
The definitions of terms and symbols in this specification are as follows.
(1) Refractive index (nx, ny, nz)
“Nx” is the refractive index in the direction in which the in-plane refractive index is maximum (ie, the slow axis direction), and “ny” is the direction orthogonal to the slow axis in the plane (ie, the fast axis direction). “Nz” is the refractive index in the thickness direction.
(2) In-plane retardation (Re)
“Re (550)” is an in-plane retardation measured with light having a wavelength of 550 nm at 23 ° C. Re (550) is obtained by the formula: Re = (nx−ny) × d, where d (nm) is the thickness of the layer (film). “Re (450)” is an in-plane retardation measured with light having a wavelength of 450 nm at 23 ° C.
(3) Thickness direction retardation (Rth)
“Rth (550)” is a retardation in the thickness direction measured with light having a wavelength of 550 nm at 23 ° C. Rth (550) is determined by the formula: Rth = (nx−nz) × d, where d (nm) is the thickness of the layer (film). “Rth (450)” is a retardation in the thickness direction measured with light having a wavelength of 450 nm at 23 ° C.
(4) Nz coefficient The Nz coefficient is obtained by Nz = Rth / Re.

A. Overall configuration diagram 1 of a conductive film for transfer is a schematic cross-sectional view of a conductive film for transfer according to one embodiment of the present invention. The transfer conductive film 10 includes a temporary support 11, a resin layer 12 provided to be peelable from the temporary support 11, and a conductive layer 13 in this order. The conductive layer 13 is laminated directly on the resin layer 12 (that is, without an adhesive layer or the like).

  The transfer conductive film 10 can be used when a conductive layer is applied to the optical laminate. More specifically, the surface on the conductive layer 13 side is attached to another optical member (for example, an image element (for example, a liquid crystal panel or an organic EL panel), an optical film (for example, a retardation film), a polarizing plate, or the like). Then, the conductive layer can be applied to the optical layered body by transferring the layered body A composed of the resin layer 12 and the conductive layer 13 so that the temporary support 11 is peeled off. Conventionally, a conductive layer is applied to an optical laminate in a state of being formed on a substrate, and the optical laminate includes a substrate. If the conductive film for transfer of the present invention is used, a conductive layer is formed. In this case, an optical laminate that does not include a base material that is necessary can be formed. Usually, the base material is rigid because it functions as a support, but an optical laminate not including such a base material is excellent in flexibility. Moreover, in the optical laminated body which does not contain the said base material, when bent, there is little load concerning a conductive layer and it is hard to damage a conductive layer.

  Furthermore, if the conductive film for transfer of the present invention is used, a rigid base material is eliminated even in an optical laminate including an optical member that is easily damaged during a process for forming a conductive layer (for example, a heat treatment). be able to. For example, if the film including the polarizing plate is directly subjected to a treatment such as sputtering, the polarizing plate is damaged, but if the transfer conductive film of the present invention is used, the polarizing plate is not damaged. An optical laminate can be formed.

A-1. Conductive layer In one embodiment, the conductive layer may function as an electrode of a touch device.

  Preferably, the conductive layer is made of a metal oxide. Examples of the metal oxide include indium oxide, tin oxide, zinc oxide, indium-tin composite oxide, tin-antimony composite oxide, zinc-aluminum composite oxide, and indium-zinc composite oxide. Of these, indium-tin composite oxide (ITO) is preferable. The metal oxide may be a crystallized metal oxide. As described later, the crystallized metal oxide means a metal oxide obtained by forming a metal oxide film and then heating (for example, heating at 120 ° C. to 200 ° C.).

  The conductive layer is preferably light transmissive. The total light transmittance of the conductive layer is preferably 80% or more, more preferably 85% or more, and further preferably 90% or more. By forming a conductive layer from the metal oxide, a conductive layer with high light transmittance can be formed.

  The surface resistance value of the conductive layer is preferably 0.1Ω / □ to 1000Ω / □, more preferably 0.5Ω / □ to 500Ω / □, and particularly preferably 1Ω / □ to 250Ω / □. .

  In one embodiment, the conductive layer is formed directly on the resin layer. As a specific example of this embodiment, a metal oxide layer is formed on the resin layer by any appropriate film formation method (for example, vacuum deposition method, sputtering method, CVD method, ion plating method, spray method, etc.). And forming a conductive layer to obtain a conductive layer. The metal oxide layer may be used as a conductive layer as it is, or may be further heated to crystallize the metal oxide. The temperature at the time of heating is, for example, 120 ° C to 200 ° C.

  The thickness of the conductive layer is preferably 50 nm or less, and more preferably 40 nm or less. If it is such a range, the conductive layer excellent in light transmittance can be obtained. The lower limit of the thickness of the conductive layer is preferably 1 nm, more preferably 5 nm.

  The conductive layer may be patterned. Any appropriate method can be adopted as a patterning method depending on the form of the conductive layer. For example, it can be patterned by an etching method, a laser method, or the like. The shape of the pattern of the conductive layer may be any appropriate shape depending on the application. For example, the patterns described in JP-T-2011-511357, JP-A-2010-164938, JP-A-2008-310550, JP-T-2003-511799, and JP-T-2010-541109 are exemplified.

A-2. Resin Layer The 50 nm depth hardness of the resin layer by the nanoindentation method is preferably 0.3 GPa or more, more preferably 0.32 GPa or more, and further preferably 0.4 GPa or more. “Xnm depth hardness by nanoindentation method” and “Xnm depth elastic modulus by nanoindentation method” are the surface of the resin layer formed on the temporary support opposite to the temporary support. The load applied to the indenter and the indentation depth when the indenter is pushed in are continuously measured during loading and unloading, and the obtained load load-indentation depth curve is obtained. In this specification, the measurement conditions are as follows: evaluation temperature: 25 ° C., load / unloading speed: 1000 nm / s, and indentation depth: X nm. “Xnm depth hardness H by nanoindentation method” is calculated by the following formula (1) based on the load (maximum load Pmax) when pushed to Xnm and the contact area between the indenter and the sample (contact projection area Ac). Calculated.
The “Xnm depth elastic modulus Er by the nanoindentation method” is calculated from the inclination (contact rigidity S) at the time of unloading of the load load-indentation depth curve and the contact area between the indenter and the sample (projected area Ac). Is calculated by the following equation (2).

  In the present invention, by forming a conductive layer on the resin layer having the above-described hardness, a conductive film for transfer that can contribute to the realization of an optical laminate in which a hologram-like appearance defect is prevented is obtained. be able to. More specifically, if the resin layer is formed and a conductive layer is formed on the resin layer, the resin layer is not required by heating during the formation of the conductive layer (for example, heating for crystallizing the metal oxide). As a result, a conductive film for transfer excellent in appearance can be obtained. By using the conductive film for transfer, an image display device (for example, a touch device) having excellent display characteristics can be obtained. The upper limit of the 50 nm depth hardness by the nanoindentation method of the resin layer is preferably 5 GPa or less, more preferably 2 GPa or less.

  The 100 nm depth hardness of the resin layer by the nanoindentation method is preferably 0.2 GPa or more, more preferably 0.3 GPa or more, and further preferably 0.4 GPa or more. If it is such a range, the said external appearance improvement effect of this invention will become remarkable. The upper limit of the 100 nm depth hardness by the nanoindentation method of the resin layer is preferably 5 GPa or less, more preferably 2 GPa or less.

  The 50 nm depth elastic modulus of the resin layer by the nanoindentation method is preferably 4 GPa or more, more preferably 4.2 GPa or more, and further preferably 5 GPa or more. If it is such a range, the said external appearance improvement effect of this invention will become remarkable. The upper limit of the 50 nm depth elastic modulus of the resin layer by the nanoindentation method is preferably 30 GPa or less, more preferably 20 GPa or less. The optical laminate obtained using the transfer conductive film having a resin layer having an elastic modulus of 30 GPa or less is more excellent in flexibility. In the optical layered body, when bent, the load applied to the conductive layer is small and the conductive layer is not easily damaged.

  The 100 nm depth elastic modulus of the resin layer by the nanoindentation method is preferably 4 GPa or more, more preferably 4.3 GPa or more, and further preferably 5 GPa or more. If it is such a range, the said external appearance improvement effect of this invention will become remarkable. The upper limit of the 100 nm depth elastic modulus of the resin layer by the nanoindentation method is preferably 30 GPa or less, more preferably 20 GPa or less. The optical laminate obtained using the transfer conductive film having a resin layer having an elastic modulus of 30 GPa or less is more excellent in flexibility. In the optical layered body, when bent, the load applied to the conductive layer is small and the conductive layer is not easily damaged.

  The hardness and elastic modulus can be controlled by the type of resin constituting the resin layer, the type / composition of the monomer component constituting the resin, the degree of polymerization, and the like.

  The thickness of the resin layer is preferably 1 μm to 20 μm, more preferably 1 μm to 15 μm, and still more preferably 1 μm to 10 μm. If it is such a range, the said external appearance improvement effect of this invention will become remarkable. Moreover, the optical laminated body obtained using the electroconductive film for transfer which has a resin layer whose thickness is the said range is more excellent in flexibility. In the optical layered body, when bent, the load applied to the conductive layer is small and the conductive layer is not easily damaged.

  The resin layer includes any appropriate resin. The resin may be a thermoplastic resin or a curable resin. Preferably, the resin layer includes a curable resin. As the curable resin constituting the resin layer, for example, an acrylic resin, an epoxy resin, a silicone resin, or a mixture thereof is used.

  The glass transition temperature of the resin constituting the resin layer is preferably 120 ° C to 300 ° C, more preferably 130 ° C to 250 ° C.

  The resin layer is formed by applying a resin layer forming composition on a temporary support and then curing the composition.

  Preferably, the resin layer forming composition contains a polyfunctional monomer, an oligomer derived from a polyfunctional monomer, and / or a prepolymer derived from a polyfunctional monomer as a curable compound serving as a main component. Examples of the polyfunctional monomer include tricyclodecane dimethanol diacrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane triacrylate, pentaerythritol tetra (meth) acrylate, and dimethylolpropanthate. Tetraacrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol (meth) acrylate, 1,9-nonanediol diacrylate, 1,10-decanediol (meth) acrylate, polyethylene glycol di (meth) acrylate , Polypropylene glycol di (meth) acrylate, dipropylene glycol diacrylate, isocyanuric acid tri (meth) acrylate, ethoxylated glycerin Triacrylate, and ethoxylated pentaerythritol tetraacrylate and the like. A polyfunctional monomer may be used independently and may be used in combination of multiple.

  The content ratio of the polyfunctional monomer, the oligomer derived from the polyfunctional monomer and the prepolymer derived from the polyfunctional monomer is preferably 30% by weight with respect to the total amount of the monomer, oligomer and prepolymer in the resin layer forming composition. -100% by weight, more preferably 40% by weight to 95% by weight, particularly preferably 50% by weight to 95% by weight.

  The resin layer forming composition may contain a monofunctional monomer. When the resin layer forming composition contains a monofunctional monomer, the content ratio of the monofunctional monomer is preferably 40% by weight or less based on the total amount of the monomer, oligomer and prepolymer in the resin layer forming composition. More preferably, it is 20% by weight or less.

  Examples of the monofunctional monomer include ethoxylated o-phenylphenol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, 2-ethylhexyl acrylate, lauryl acrylate, isooctyl acrylate, and isostearyl. Examples include acrylate, cyclohexyl acrylate, isophoronyl acrylate, benzyl acrylate, 2-hydroxy-3-phenoxy acrylate, acryloylmorpholine, 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and hydroxyethyl acrylamide. .

  The resin layer forming composition may contain urethane (meth) acrylate and / or urethane (meth) acrylate oligomer. The urethane (meth) acrylate can be obtained, for example, by reacting hydroxy (meth) acrylate obtained from (meth) acrylic acid or (meth) acrylic acid ester and polyol with diisocyanate. Urethane (meth) acrylates and urethane (meth) acrylate oligomers may be used alone or in combination.

  Examples of the (meth) acrylic acid ester include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, cyclohexyl (meth) acrylate, and the like.

  Examples of the polyol include ethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, diethylene glycol, dipropylene glycol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, 1, 6-hexanediol, 1,9-nonanediol, 1,10-decanediol, 2,2,4-trimethyl-1,3-pentanediol, 3-methyl-1,5-pentanediol, neopentyl hydroxypivalate Glycol ester, tricyclodecane dimethylol, 1,4-cyclohexanediol, spiroglycol, tricyclodecane dimethylol, hydrogenated bisphenol A, ethylene oxide-added bisphenol A, propylene oxide-added bisphenol A, trime Ethane, trimethylol propane, glycerin, 3-methylpentane-1,3,5-triol, pentaerythritol, dipentaerythritol, tripentaerythritol, glucose, etc. can be mentioned.

  As said diisocyanate, various aromatic, aliphatic, or alicyclic diisocyanates can be used, for example. Specific examples of the diisocyanate include tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 2,4-tolylene diisocyanate, 4,4-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, 3,3-dimethyl-4,4. -Diphenyl diisocyanate, xylene diisocyanate, trimethylhexamethylene diisocyanate, 4,4-diphenylmethane diisocyanate, and hydrogenated products thereof.

  The total content of the urethane (meth) acrylate and urethane (meth) acrylate oligomers is preferably 5% by weight to 70% by weight with respect to the total amount of monomers, oligomers and prepolymers in the resin layer forming composition. More preferably, it is 5 to 50% by weight, and particularly preferably 5 to 30% by weight. If it is such a range, the resin layer excellent in the balance of hardness, a softness | flexibility, and adhesiveness can be formed.

  The resin layer forming composition preferably contains any appropriate photopolymerization initiator. Examples of the photopolymerization initiator include 2,2-dimethoxy-2-phenylacetophenone, acetophenone, benzophenone, xanthone, 3-methylacetophenone, 4-chlorobenzophenone, 4,4′-dimethoxybenzophenone, benzoinpropyl ether, benzyldimethyl Ketals, N, N, N ′, N′-tetramethyl-4,4′-diaminobenzophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, thioxanthone compounds, etc. Can be mentioned.

  The resin layer forming composition may or may not contain a solvent. Examples of the solvent include dibutyl ether, dimethoxymethane, methyl acetate, ethyl acetate, isobutyl acetate, methyl propionate, ethyl propionate, methanol, ethanol, methyl isobutyl ketone (MIBK), and the like. These may be used alone or in combination.

  The composition for forming a resin layer may further contain any appropriate additive. Examples of additives include leveling agents, anti-blocking agents, dispersion stabilizers, thixotropic agents, antioxidants, UV absorbers, antifoaming agents, thickeners, dispersants, surfactants, catalysts, fillers, and lubricants. And antistatic agents.

  Any appropriate method can be adopted as a method for applying the resin layer forming composition. Examples thereof include a bar coating method, a roll coating method, a gravure coating method, a rod coating method, a slot orifice coating method, a curtain coating method, a fountain coating method, and a comma coating method.

  Arbitrary appropriate hardening processing may be employ | adopted as a hardening method of the composition for resin layer formation. Typically, the curing process is performed by ultraviolet irradiation. The integrated light quantity of ultraviolet irradiation is preferably 200 mJ to 400 mJ.

  Before the resin layer forming composition is cured, the coating layer formed of the resin layer forming composition may be heated. The heating temperature is preferably 90 ° C to 140 ° C, more preferably 100 ° C to 130 ° C, and further preferably 105 ° C to 120 ° C.

A-3. Other layers The conductive film for transfer may further have other layers. For example, another resin layer and / or a liquid crystal layer may be disposed between the resin layer and the temporary support. The 50 nm depth hardness of another resin layer and / or liquid crystal layer by the nanoindentation method is preferably 0.1 GPa to 2.0 GPa, more preferably 0.15 GPa to 1.0 GPa. In the present invention, by providing a resin layer having hardness and elastic modulus as described in the section A-2, even if a relatively flexible layer (for example, another resin layer, a liquid crystal layer) is provided, A hologram-like appearance defect can be prevented. The other resin layer and liquid crystal layer are provided so as to be peelable from the temporary support.

  The liquid crystal layer includes any appropriate liquid crystal compound. In one embodiment, the liquid crystal layer has a refractive index characteristic of nz> nx ≧ ny.

  The thickness direction retardation Rth (550) of the liquid crystal layer is preferably −260 nm to −10 nm, more preferably −230 nm to −15 nm, and still more preferably −215 nm to −20 nm.

  In one embodiment, the liquid crystal layer has a refractive index of nx = ny. Here, “nx = ny” includes not only the case where nx and ny are exactly equal, but also the case where nx and ny are substantially equal. Specifically, Re (550) is less than 10 nm. In another embodiment, the liquid crystal layer has a refractive index relationship of nx> ny. In this case, the in-plane retardation Re (550) of the liquid crystal layer is preferably 10 nm to 150 nm, and more preferably 10 nm to 80 nm.

  The liquid crystal layer is a liquid crystal layer fixed in homeotropic alignment. The liquid crystal material (liquid crystal compound) that can be homeotropically aligned may be a liquid crystal monomer or a liquid crystal polymer. Specific examples of the liquid crystal compound and the method for forming the liquid crystal layer include the liquid crystal compounds and methods described in JP-A-2002-333642, [0020] to [0042].

  The thickness of the liquid crystal layer is preferably 0.1 μm to 10 μm, more preferably 0.1 μm to 5 μm, and still more preferably 0.2 μm to 3 μm.

  The total light transmittance of the liquid crystal layer is preferably 80% or more, more preferably 85% or more, and further preferably 90% or more.

A-4. Temporary Support As the resin constituting the temporary support, any appropriate resin can be used as long as the effects of the present invention are obtained. Examples of the resin constituting the temporary support include cycloolefin resins, polyimide resins, polyvinylidene chloride resins, polyvinyl chloride resins, polyethylene terephthalate resins, polyethylene naphthalate resins, and the like.

  The thickness of the temporary support is preferably 8 μm to 500 μm, more preferably 50 μm to 250 μm.

  The adhesive strength of the temporary support to the resin layer at 23 ° C. is preferably 0.01 N / 25 mm to 1.00 N / 25 mm, and more preferably 0.01 N / 25 mm to 0.70 N / 25 mm. If it is such a range, the conductive film for transfer which can transfer the laminated body A easily can be obtained. The adhesive force was measured by a method according to JIS Z 0237: 2000, and the temporary support was peeled off at a tensile speed of 300 mm / min and a peeling angle of 180 ° from the manufactured conductive film for transfer. Say.

  The adhesive strength of the temporary support to the liquid crystal layer at 23 ° C. is preferably 0.01 N / 25 mm to 1.00 N / 25 mm, and more preferably 0.01 N / 25 mm to 0.70 N / 25 mm. If it is such a range, it is an electroconductive film for transfer provided with a liquid crystal as mentioned above, Comprising: The electroconductive film for transfer which can transfer the laminated body A easily can be obtained.

  You may perform various surface treatments with respect to the said temporary support body as needed. As the surface treatment, any appropriate method is adopted depending on the purpose. In one embodiment, a release layer may be provided on the surface of the temporary support on the liquid crystal layer side in order to facilitate peeling from the resin layer. The release layer can be a layer composed of any appropriate material as long as the adhesive force can be expressed, and is formed by, for example, a well-known release treatment (for example, application of a silicone release layer). Layer. In the case where a liquid crystal layer is provided, an alignment layer may be provided in order to improve the orientation of the liquid crystal layer.

B. Optical Laminate The optical laminate of the present invention includes a laminate A (a laminate comprising a liquid crystal layer and a conductive layer) transferred from the transfer conductive film. In one embodiment, a touch device comprising the optical stack is provided. In the touch device, the conductive layer functions as an electrode. The touch device is excellent in flexibility and useful in that the conductive layer is not easily damaged even when it is bent.

  FIG. 2 is a schematic cross-sectional view of an optical laminate according to one embodiment of the present invention. The optical laminate 100 includes an optical member 20, a conductive layer 13, and a resin layer 12 in this order. In one embodiment, the optical member 20 and the conductive layer 13 are laminated via the pressure-sensitive adhesive layer 30, and the pressure-sensitive adhesive layer 30 is in contact with the optical member 20 and the conductive layer 13.

  In the optical laminate 100, the laminate A composed of the conductive layer 13 and the resin layer 12 is a laminate transferred from the conductive film for transfer. The conductive layer 13 is formed directly on the resin layer 12.

  FIG. 3 is a schematic cross-sectional view of an optical laminate according to another embodiment of the present invention. The optical laminate 200 includes an optical member 20, a conductive layer 13, a resin layer 12, and another optical member 40 in this order. In one embodiment, the optical member 20 and the conductive layer 13 are laminated via the pressure-sensitive adhesive layer 30, and the pressure-sensitive adhesive layer 30 is in contact with the optical member 20 and the conductive layer 13. In one embodiment, resin layer 12 and another optical member 40 are laminated via pressure sensitive adhesive layer 30, and pressure sensitive adhesive layer 30 is in contact with resin layer 12 and another optical member 40. In addition, when the conductive film for transfer includes another layer (for example, a liquid crystal layer) between the resin layer and the temporary support, the optical member, the conductive layer, the resin layer, and the other An optical laminate including a layer and another optical member in this order may be provided. Another layer and another optical member may be laminated via an adhesive layer, and the adhesive layer is in contact with another layer and another optical member.

  Examples of the optical member 20 include an image element (for example, a liquid crystal panel and an organic EL panel), an optical film (for example, a retardation film), a polarizing plate, a circularly polarizing plate, and the like.

  In one embodiment, a polarizing plate or a circularly polarizing plate is used as the optical member 20. According to another embodiment, a polarizing plate or a circularly polarizing plate is used as another optical member 40. When applied to an image display device (for example, a touch device), the optical layered body may be arranged such that the conductive layer is closer to the viewing side than the polarizing plate or the circularly polarizing plate. You may arrange | position so that it may become an inner side (opposite side from a visual recognition side) from a polarizing plate.

B-1. Polarizing plate In one embodiment, an optical laminate in which a polarizing plate is used as an optical member or another optical member is provided. That is, an optical laminate including a polarizing plate, a conductive layer, and a resin layer in this order, or an optical laminate including a conductive layer, a resin layer, and a polarizing plate in this order is provided. Conventionally, when a conductive layer is formed directly on a film containing a polarizing plate by a conductive layer application treatment such as sputtering, there is a problem that the polarizing plate is damaged during the conductive layer application treatment. If a conductive film is used, an optical laminated body can be formed without damaging a polarizing plate. The example of the polarizing plate used for the said optical laminated body is demonstrated below.

  The polarizing plate includes a polarizer. The polarizing plate preferably further includes a protective film on one side or both sides of the polarizer.

  The thickness of the polarizer is not particularly limited, and an appropriate thickness can be adopted depending on the purpose. The thickness is typically about 1 μm to 80 μm. In one embodiment, a thin polarizer is used, and the thickness of the polarizer is preferably 20 μm or less, more preferably 15 μm or less, further preferably 10 μm or less, and particularly preferably 6 μm or less. It is. By using such a thin polarizer, a thin optical laminate can be obtained.

  The polarizer preferably exhibits absorption dichroism at any wavelength of 380 nm to 780 nm. The single transmittance of the polarizer is preferably 40.0% or more, more preferably 41.0% or more, further preferably 42.0% or more, and particularly preferably 43.0% or more. The polarization degree of the polarizer is preferably 99.8% or more, more preferably 99.9% or more, and further preferably 99.95% or more.

  Preferably, the polarizer is an iodine-based polarizer. More specifically, the polarizer may be composed of a polyvinyl alcohol resin (hereinafter referred to as “PVA resin”) film containing iodine.

  Arbitrary appropriate resin may be employ | adopted as PVA-type resin which forms the said PVA-type resin film. Examples thereof include polyvinyl alcohol and ethylene-vinyl alcohol copolymer. Polyvinyl alcohol is obtained by saponifying polyvinyl acetate. An ethylene-vinyl alcohol copolymer can be obtained by saponifying an ethylene-vinyl acetate copolymer. The degree of saponification of the PVA resin is usually 85 mol% to 100 mol%, preferably 95.0 mol% to 99.95 mol%, more preferably 99.0 mol% to 99.93 mol%. It is. The saponification degree can be determined according to JIS K 6726-1994. By using a PVA-based resin having such a saponification degree, a polarizer having excellent durability can be obtained. If the degree of saponification is too high, there is a risk of gelation.

  The average degree of polymerization of the PVA-based resin can be appropriately selected according to the purpose. Average polymerization degree is 1000-10000 normally, Preferably it is 1200-5000, More preferably, it is 1500-4500. The average degree of polymerization can be determined according to JIS K 6726-1994.

  As a manufacturing method of the said polarizer, the method (I) of extending | stretching and dye | staining a PVA-type resin film single-piece | unit, and the method of extending | stretching and dye | staining the laminated body (i) which has a resin base material and a polyvinyl alcohol-type resin layer ( II) and the like. Since the method (I) is a well-known and commonly used method in the art, detailed description thereof is omitted. In the production method (II), preferably, a laminate (i) having a resin base material and a polyvinyl alcohol resin layer formed on one side of the resin base material is stretched and dyed, A step of producing a polarizer. The laminate (i) can be formed by applying and drying a coating liquid containing a polyvinyl alcohol-based resin on a resin substrate. The laminate (i) may be formed by transferring a polyvinyl alcohol-based resin film onto a resin base material. Details of the production method (II) are described in, for example, Japanese Patent Application Laid-Open No. 2012-73580, which is incorporated herein by reference.

  Any appropriate resin film can be adopted as the protective film. Examples of the protective film forming material include polyester resins such as polyethylene terephthalate (PET), cellulose resins such as triacetyl cellulose (TAC), cycloolefin resins such as norbornene resins, and olefins such as polyethylene and polypropylene. Examples thereof include resins and (meth) acrylic resins. Of these, polyethylene terephthalate (PET) is preferable.

  In one embodiment, a (meth) acrylic resin having a glutarimide structure is used as the (meth) acrylic resin.

  The protective film and the polarizer are laminated via any appropriate adhesive layer. The resin base material used at the time of producing the polarizer can be peeled off before or after the protective film and the polarizer are laminated.

  The thickness of the protective film is preferably 5 μm to 55 μm, more preferably 10 μm to 50 μm, and still more preferably 15 μm to 45 μm.

B-2. Circular Polarizing Plate FIG. 4 is a schematic cross-sectional view of an optical laminate according to one embodiment of the present invention. The optical laminate 110 includes a circularly polarizing plate 21 as an optical member. The circularly polarizing plate 21 includes a polarizer 1 and a retardation layer 2. In one embodiment, the polarizer 1 is preferably disposed on the side opposite to the stacked body A (that is, the conductive layer) of the retardation layer 2. The circularly polarizing plate 21 and the laminate A are laminated via the pressure-sensitive adhesive layer 30, and the pressure-sensitive adhesive layer 30 is in contact with the retardation layer 2 and the conductive layer 13. In another embodiment, a circularly polarizing plate is used as another optical member, and an optical laminate including an optical member, a conductive layer, a resin layer, and a circularly polarizing plate (retardation layer / polarizer) in this order. The body is provided. Also in this embodiment, it is preferable that the polarizer is disposed on the side opposite to the laminate A (that is, the resin layer) of the retardation layer.

  In one embodiment, the circularly polarizing plate further includes a protective film (not shown) on the surface of the polarizer opposite to the retardation layer. The circularly polarizing plate may include another protective film (also referred to as an inner protective film: not shown) between the polarizer and the retardation layer. As a polarizer and a protective film, what was demonstrated by the said B-1 term may be used.

  The retardation layer can function as a λ / 4 plate. The in-plane retardation Re (550) of such a retardation layer is preferably 120 nm to 160 nm, and more preferably 135 nm to 155 nm. The retardation layer typically has a refractive index ellipsoid of nx> ny ≧ nz.

  Rth (550) of the retardation layer is preferably 120 nm to 300 nm, and more preferably 135 nm to 260 nm.

  The Nz coefficient of the retardation layer is, for example, 0.9 to 2, preferably 1 to 1.8, and more preferably 1 to 1.7.

  The polarizer and the retardation layer are laminated so that the absorption axis of the polarizer and the slow axis of the retardation layer form a predetermined angle. The angle formed between the absorption axis of the polarizer and the slow axis of the retardation layer is preferably 35 ° to 55 °, more preferably 38 ° to 52 °, and further preferably 40 ° to 50 °. The angle is more preferably 42 ° to 48 °, and particularly preferably 44 ° to 46 °. If the angle is in such a range, a desired circular polarization function can be realized. Note that when an angle is referred to in this specification, the angle includes both clockwise and counterclockwise angles unless otherwise specified.

  The thickness of the retardation layer can be set so as to function most appropriately as a λ / 4 plate. In other words, the thickness can be set so as to obtain a desired in-plane retardation. Specifically, the thickness of the retardation layer is preferably 10 μm to 80 μm, more preferably 10 μm to 60 μm, and most preferably 30 μm to 50 μm.

  The retardation layer may exhibit reverse dispersion wavelength characteristics in which the retardation value increases with the wavelength of the measurement light, or may exhibit positive wavelength dispersion characteristics in which the retardation value decreases with the wavelength of the measurement light. The phase difference value may exhibit a flat chromatic dispersion characteristic that hardly changes depending on the wavelength of the measurement light.

  The λ / 4 plate is preferably a stretched polymer film. Specifically, a λ / 4 plate can be obtained by appropriately selecting the type of polymer and the stretching treatment (for example, stretching method, stretching temperature, stretching ratio, stretching direction).

  Any appropriate resin is used as the resin for forming the polymer film. Specific examples include resins constituting positive birefringent films such as cycloolefin resins such as polynorbornene, polycarbonate resins, cellulose resins, polyvinyl alcohol resins, polysulfone resins, and the like. Of these, norbornene resins and polycarbonate resins are preferable. The details of the resin forming the polymer film are described in, for example, JP-A-2014-010291. The description is incorporated herein by reference.

  Various products are commercially available as the polynorbornene. Specific examples include trade names “ZEONEX” and “ZEONOR” manufactured by ZEON CORPORATION, “Arton” manufactured by JSR, “TOPAS” trade name manufactured by TICONA, and trade names manufactured by Mitsui Chemicals, Inc. “APEL” may be mentioned.

  Examples of the stretching method include lateral uniaxial stretching, fixed end biaxial stretching, and sequential biaxial stretching. A specific example of the fixed-end biaxial stretching includes a method of stretching a polymer film in the short direction (lateral direction) while running in the longitudinal direction. This method can be apparently lateral uniaxial stretching. Also, oblique stretching can be employed. By adopting oblique stretching, a long stretched film having an orientation axis (slow axis) at a predetermined angle with respect to the width direction can be obtained.

  The thickness of the stretched film is typically 5 μm to 80 μm, preferably 15 μm to 60 μm, and more preferably 25 μm to 45 μm.

B-3. Pressure-sensitive adhesive layer The pressure-sensitive adhesive layer is formed of any appropriate pressure-sensitive adhesive. In one embodiment, the adhesive includes an adhesive resin, and examples of the resin include acrylic resins, acrylic urethane resins, urethane resins, and silicone resins. Among these, an acrylic pressure-sensitive adhesive containing an acrylic resin is preferable.

  The pressure-sensitive adhesive may further contain any appropriate additive as required. Examples of the additive include a crosslinking agent, a tackifier, a plasticizer, a pigment, a dye, a filler, an anti-aging agent, a conductive material, an ultraviolet absorber, a light stabilizer, a release modifier, a softener, and a surfactant. , Flame retardants, antioxidants and the like. As the crosslinking agent, isocyanate crosslinking agent, epoxy crosslinking agent, peroxide crosslinking agent, melamine crosslinking agent, urea crosslinking agent, metal alkoxide crosslinking agent, metal chelate crosslinking agent, metal salt crosslinking agent, A carbodiimide type crosslinking agent, an oxazoline type crosslinking agent, an aziridine type crosslinking agent, an amine type crosslinking agent, etc. are mentioned.

  The thickness of the pressure-sensitive adhesive layer is preferably 5 μm to 100 μm, more preferably 10 μm to 50 μm.

B-4. Other layers The optical layered body may include any appropriate other layer as necessary. Examples of the other layers include a hard coat layer, an antiglare layer, an antireflection layer, and a color filter layer.

C. Manufacturing method of optical laminated body The manufacturing method of the optical laminated body of this invention includes transferring the laminated body A containing a liquid crystal layer and a conductive layer to the optical member from the said electroconductive film for transfer. In one embodiment, in this manufacturing method, a conductive layer and an optical member are laminated via an adhesive layer. As the conductive film for transfer, the optical member, and the pressure-sensitive adhesive layer, those described in the above sections A and B are used.

  After transferring the laminate A to the optical member, another optical member may be laminated on the resin layer of the laminate A via an adhesive layer.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples at all. The evaluation methods in the examples are as follows. The thickness was measured using a Peacock precision measuring instrument digital gauge cordless type “DG-205” manufactured by Ozaki Seisakusho.

[Example 1]
A resin layer was formed on the temporary support using the polyethylene terephthalate base material (trade name “Panapeel” manufactured by Panac Co., Ltd.) subjected to the release treatment as a temporary support.
Urethane-based multifunctional acrylate A (trade name “UNIDIC ELS888”) and urethane-based multifunctional acrylate B (product name “UNIDIC RS28-605”, manufactured by DIC) as a binder resin. A coating composition prepared by mixing urethane-based polyfunctional acrylate B at a weight ratio of 8: 2 and diluting with ethyl acetate was prepared using a gravure coater on the release-treated surface of the temporary support. The thickness after drying was 5 μm, and then the coating layer was heated at 80 ° C. Next, the high-pressure mercury lamp was irradiated with ultraviolet rays with an integrated light amount of 250 mJ / cm ² to provide a temporary support. And a laminate comprising a resin layer was obtained.
This laminate was put into a take-up type sputtering apparatus, and an indium tin oxide layer (thickness: 30 nm) was formed on the surface of the resin layer. Sputtering treatment was performed in a 0.4 Pa atmosphere composed of 98% argon gas and 2% oxygen using a sintered body composed of 97 wt% indium oxide and 3 wt% tin oxide. Thereafter, the indium tin oxide was converted from amorphous to crystalline by heating at 130 ° C. for 90 minutes to obtain a conductive film for transfer (conductive layer / resin layer / temporary support).

[Example 2]
Transferring in the same manner as in Example 1 except that the weight ratio of the urethane polyfunctional acrylate A and the urethane polyfunctional acrylate B was urethane polyfunctional acrylate A: urethane polyfunctional acrylate B = 2: 8. A conductive film was obtained.

[Example 3]
A liquid crystal layer was formed on the temporary support by using the polyethylene terephthalate base material (trade name “Panapeel” manufactured by Panac Co., Ltd.) subjected to the release treatment as a temporary support.
20 parts by weight of a side chain type liquid crystal polymer represented by the following chemical formula (I) (numbers 65 and 35 in the formula indicate mol% of the monomer units and are represented by block polymer for convenience: weight average molecular weight 5000), Dissolve 80 parts by weight of a polymerizable liquid crystal exhibiting a nematic liquid crystal phase (manufactured by BASF: trade name Palicolor LC242) and 5 parts by weight of a photopolymerization initiator (trade name: Irgacure 907, manufactured by Ciba Specialty Chemicals) in 200 parts by weight of cyclopentanone. Thus, a liquid crystal coating solution was prepared. And after apply | coating the said coating liquid to PET film (temporary support body) with a bar coater, the liquid crystal was orientated by heat-drying for 4 minutes at 80 degreeC. The liquid crystal layer was irradiated with ultraviolet rays to cure the liquid crystal layer, thereby forming a liquid crystal solidified layer (thickness: 0.58 μm) on the PET film (temporary support). The in-plane retardation Re (550) of this liquid crystal layer is 0 nm, the thickness direction retardation Rth (550) is −71 nm (nx: 1.5326, ny: 1.5326, nz: 1.6550), and nz. Refractive index characteristics of> nx = ny were shown.

Next, a resin layer was formed on the liquid crystal layer by the same method as in Example 1.
Next, the laminate composed of the support, the liquid crystal layer, and the resin layer was put into a sputtering apparatus, and an amorphous indium tin oxide layer having a thickness of 30 nm was formed on the surface of the liquid crystal layer. Thereafter, indium tin oxide was converted from amorphous to crystalline by heat treatment at 130 ° C. for 90 minutes to obtain a conductive film for transfer (conductive layer / resin layer / liquid crystal layer / temporary support). .

[Comparative Example 1]
Using the polyethylene terephthalate base material (trade name “Panapeel”, manufactured by Panac Co., Ltd.) subjected to the release treatment in the same manner as in Example 3 as a temporary support, the following method was used on the temporary support. A liquid crystal layer was formed.
Next, the laminate composed of the temporary support and the liquid crystal layer was put into a sputtering apparatus, and an amorphous indium tin oxide layer having a thickness of 30 nm was formed on the surface of the liquid crystal layer. Then, indium tin oxide was converted from amorphous to crystalline by heat treatment at 130 ° C. for 90 minutes to obtain a conductive film for transfer (conductive layer / liquid crystal layer / temporary support).

[Evaluation]
(1) Hardness and elastic modulus of resin layer and liquid crystal layer Hysitron Inc. A load factor-indentation depth curve was obtained using a Tribodenter manufactured by the company, and the hardness H and elastic modulus Er were measured by the nanoindentation method. The indenter was Berkovich (triangular pyramid type), single indentation measurement, and the measurement environment was 25 ° C. The indentation depth was 20 nm, 50 nm, and 100 nm.
The hardness H was calculated by the following formula (1) from the load (maximum load Pmax) when the indenter was pushed to the above-mentioned indentation depth and the contact area between the indenter and the sample (contact projected area Ac).
Further, the elastic modulus Er was calculated by the following formula (2) from the inclination at the time of unloading of the load load-indentation depth curve (contact rigidity S) and the contact area between the indenter and the sample (projected area Ac).
Table 1 shows the evaluation results of the hardness H and the elastic modulus Er.
(2) Appearance evaluation The presence or absence of a hologram was confirmed visually. The evaluation results are shown in Table 1.
Moreover, about Example 1, Example 2, and the comparative example 1, it was confirmed using a microscope whether the regular wavy undulation was observed on the conductive layer surface. The evaluation results are shown in FIG.

  As is clear from Table 1, the transfer conductive film of the present invention includes a resin layer adjacent to the conductive layer, and the 50 nm depth hardness of the resin layer by the nanoindentation method is 0.3 GPa or more. , Hologram-like appearance defects can be suppressed.

DESCRIPTION OF SYMBOLS 10 Transfer conductive film 11 Temporary support 12 Resin layer 13 Conductive layer 20 Optical member

Claims (11)

A temporary support, a resin layer provided so as to be peelable from the temporary support, and a conductive layer disposed directly on the resin layer,
The conductive layer is composed of a metal oxide;
The resin layer has a 50 nm depth hardness by nanoindentation method of 0.3 GPa or more.
Transfer conductive film.   The conductive film for transfer according to claim 1, wherein the resin layer has a thickness of 1 μm to 20 μm.   The conductive film for transfer according to claim 1 or 2, wherein the resin layer has a 100 nm depth hardness by a nanoindentation method of 0.2 GPa or more.   The conductive film for transfer according to any one of claims 1 to 3, wherein the resin layer has a 50 nm depth elastic modulus by nanoindentation method of 4 GPa or more.   The conductive film for transfer according to any one of claims 1 to 4, wherein the resin layer has a 100 nm depth elastic modulus of 4 GPa or more by a nanoindentation method.   The conductive film for transfer according to any one of claims 1 to 5, wherein the metal oxide is an indium-tin composite oxide.   The conductive film for transfer according to claim 1, wherein the metal oxide is a crystallized metal oxide.   The conductive film for transfer according to claim 1, wherein the conductive layer is patterned.   The conductive film for transfer according to any one of claims 1 to 8, further comprising a liquid crystal layer disposed between the resin layer and the temporary support. An optical member, a pressure-sensitive adhesive layer, the conductive layer according to claim 1, 6, 7 or 8, and the resin layer according to any one of claims 1 to 5,
The conductive layer is directly laminated on the liquid crystal layer;
Optical laminate.   A touch device comprising the optical laminate according to claim 10.