JP2017061069A - Transparent conductive film laminate and touch panel including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transparent conductive film laminate using a substrate including a polyester, enabling a sufficient material strength as well as a sufficient restrictive effect on iridescent irregularity, and also to provide a touch panel including the same.SOLUTION: A transparent conductive film laminate includes a transparent conductive membrane 6, a first transparent resin film 4, an adhesive layer 8 and a second transparent resin film 9 in this order. The first transparent resin film 4 is a biaxially-drawn polyester resin film. As a total phase difference of the first transparent resin film 4 and the second transparent resin film 9, an in-plane phase difference value is 150 nm or less and a thickness direction phase difference value is 1100 nm or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a transparent conductive film laminate having a transparent conductive film and a plurality of transparent resin films, and a touch panel including the same.

  Recently, with the spread of tablets, smartphones, and PCs with touch panels, opportunities to handle electronic devices outdoors have increased. When viewing the display outdoors, it is often viewed with polarized sunglasses. If a transparent conductive film using a polyethylene terephthalate (PET) film is used, the in-plane position of the PET film itself There is a problem that rainbow unevenness occurs due to the phase difference (generally 1000 to 2000 nm), and the visibility of the display is greatly reduced.

  For this reason, development of a transparent conductive film using a base material (polycycloolefin or the like) having a small retardation value has been advanced. However, polycycloolefins have disadvantages such as weak material strength, and the use of inexpensive and high-strength materials has been studied. Further, if the thickness is reduced in order to reduce the phase difference using another material, there is a problem that handling properties at the time of manufacturing and processing of the member are lowered.

  For this reason, Patent Document 1 proposes a transparent conductive film based on a transparent resin film made of stretched polyester or the like having an in-plane retardation value of 4000 nm or more. According to this transparent conductive film, color unevenness is less likely to occur even when viewed through polarized sunglasses.

Japanese Patent Laid-Open No. 2004-214069

  However, such a polyester film having a large in-plane retardation value has a demerit that the material strength is weak due to uniaxial stretching, and is difficult to handle as a general-purpose material.

  Accordingly, an object of the present invention is to provide a transparent conductive film laminate having sufficient material strength and sufficient rainbow unevenness suppression effect by using a substrate containing polyester, and a touch panel including the same. Is to provide.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have used a base material containing polyester to bring the entire in-plane retardation value and thickness direction retardation value within a predetermined range. The inventors have found that the above object can be achieved and have reached the present invention.

  That is, the transparent conductive film laminate of the present invention is a transparent conductive film laminate having a transparent conductive film, a first transparent resin film, an adhesive layer, and a second transparent resin film in this order, The one transparent resin film is a biaxially stretched polyester-based resin film, and the in-plane retardation value is 150 nm or less as a total retardation of the first transparent resin film and the second transparent resin film. The phase difference value is 1100 nm or less. In addition, the various physical property values in the present invention are values measured by a method employed in Examples and the like.

  In general, a biaxially stretched polyester-based resin film has sufficient material strength and is inexpensive, but has an in-plane retardation of about 1000 to 2000 nm, which is the basis of a transparent conductive film laminate. When used as a material, the effect of depolarizing polarized light by wavelength dispersion becomes insufficient, resulting in rainbow unevenness. On the other hand, as in the present invention, using a biaxially stretched polyester resin film, the in-plane retardation value as the total retardation is 150 nm or less and the thickness direction retardation value is 1100 nm or less. Thus, as the results of the examples show, a sufficient effect of suppressing rainbow unevenness can be obtained.

  The details of the reason are not clear, but are considered as follows. That is, when the in-plane retardation value as a whole is 150 nm or less, there is an action of circularly polarizing linearly polarized light (including elliptical polarization). This is because the thickness direction retardation value is 1100 nm or less. In combination, it is considered that a sufficient rainbow unevenness suppressing effect can be obtained because the change in the color tone with respect to the spread in the viewing direction can be suppressed.

  As a result, according to the transparent conductive film laminate of the present invention, a transparent conductive film laminate having sufficient material strength and sufficient rainbow unevenness suppression effect can be obtained by using a substrate containing polyester. Can provide the body.

  In the above, the first transparent resin film preferably has an in-plane retardation value of 150 nm or less and a thickness direction retardation value of 1100 nm or less. When the first transparent resin film has such a retardation value, the retardation value as described above can be realized as a whole by using an optically isotropic material as the second transparent resin film. Thus, a sufficient effect of suppressing rainbow unevenness can be easily obtained.

  The second transparent resin film preferably contains polycycloolefin, polycarbonate, triacetyl cellulose, polyvinyl alcohol, or cycloolefin copolymer. Such resins are classified as light isotropic materials, and together with the first transparent resin film as described above, the above retardation value can be realized as a whole, and a sufficient rainbow unevenness suppressing effect can be achieved. It becomes easy to obtain.

  Moreover, it is preferable that the thickness of said 1st transparent resin film is 5-50 micrometers. When the thickness is within such a range, a biaxially stretched polyester resin film having an in-plane retardation value of 150 nm or less and a thickness direction retardation value of 1100 nm or less can be easily produced at low cost. Moreover, sufficient handling property is obtained by laminating | stacking a 2nd transparent resin film.

  The first transparent resin film is a long or rectangular sheet, and the orientation axis is preferably 10 to 45 ° with respect to the long side or the short side. The transparent conductive film laminate is often used by being laminated on a rectangular optical display device such as a liquid crystal cell, and the light from the optical display device may be polarized in parallel or perpendicular to its long side. Many. For this reason, in this invention, it becomes easy to arrange | position a slow axis at an angle of 10-45 degrees with respect to polarization | polarized-light because an orientation axis has an angle of 10-45 degrees with respect to either edge, and it is transparent. The action of circularly polarizing polarized light is increased by the resin film, and a sufficient rainbow unevenness suppressing effect is easily obtained.

  Moreover, it is preferable to have at least one optical adjustment layer between the first transparent resin film and the transparent conductive film. Since the refractive index can be controlled by the optical adjustment layer, the difference in reflectance between the pattern forming part and the pattern opening when the transparent conductive film is patterned can be reduced, and the transparent conductive film pattern is difficult to see, such as a touch panel. Visibility is improved in the display device.

  It is preferable to have a cured resin layer on at least one surface of the first transparent resin film or the second transparent resin film. The cured resin layer functions as a hard coat layer for preventing scratches during transportation, and can also function as an anti-blocking layer by generating irregularities on the surface.

  On the other hand, the touch panel of the present invention is obtained using the transparent conductive film laminate of the present invention. By using the transparent conductive film laminate of the present invention, it is possible to provide a touch panel having sufficient material strength and sufficient rainbow unevenness suppression effect.

It is a typical sectional view of the transparent conductive film layered product concerning one embodiment of the present invention. It is a typical sectional view of the transparent conductive film layered product concerning one embodiment of the present invention. It is a typical sectional view of the transparent conductive film layered product concerning one embodiment of the present invention. It is a typical sectional view of the transparent conductive film layered product concerning one embodiment of the present invention.

<Structure of laminate>
The transparent conductive film laminated body of this invention has the transparent conductive film 6, the 1st transparent resin film 4, the adhesive bond layer 8, and the 2nd transparent resin film 9 in this order, as shown in FIGS. It is preferable to have at least one optical adjustment layer 7 between the first transparent resin film 4 and the transparent conductive film 6. In addition, as shown in FIGS. 2 to 3, at least one surface of the first transparent resin film 4 or the second transparent resin film 9 has a cured resin layer such as the anti-blocking layer 3 or the hard coat layer 5. May be. Further, as shown in FIG. 4, the transparent conductive film laminate has the pressure-sensitive adhesive layer 2 and the protective film 1 in this order on the side of the second transparent resin film 9 where the transparent conductive film 6 is not provided. In this case, the carrier film 10 is composed of the pressure-sensitive adhesive layer 2 and the protective film 1.

(First transparent resin film)
As the first transparent resin film, a biaxially stretched polyester resin film is used. “Biaxially stretched” means that the film is stretched in at least two directions, and the bi-directional stretching may be simultaneous or sequential.

  Examples of the polyester resin include polyester resins selected from polyester, modified polyester, and blends thereof. As the polyester, for example, a polyester obtained by condensation polymerization of a carboxylic acid component and a polyol component can be used.

  Examples of the carboxylic acid component include aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and alicyclic dicarboxylic acids. Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, benzylmalonic acid, 1,4-naphthalic acid, diphenic acid, 4,4′-oxybenzoic acid, and 2,5-naphthalenedicarboxylic acid. Examples of the aliphatic dicarboxylic acid include malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, trimethyladipic acid, pimelic acid, 2,2-dimethylglutaric acid, azelaic acid, zebacic acid, fumaric acid, Maleic acid, itaconic acid, thiodipropionic acid, diglycolic acid are mentioned. Examples of the alicyclic dicarboxylic acid include 1,3-cyclopentane dicarboxylic acid, 1,2-cyclohexane dicarboxylic acid, 1,3-cyclopentane dicarboxylic acid, 1,4-cyclohexane dicarboxylic acid, and 2,5-norbornane dicarboxylic acid. Examples include acids and adamantane dicarboxylic acids. The carboxylic acid component may be a derivative such as ester, chloride, or acid anhydride. For example, dimethyl 1,4-cyclohexanedicarboxylate, dimethyl 2,6-naphthalenedicarboxylate, dimethyl isophthalate, dimethyl terephthalate And diphenyl terephthalate. A carboxylic acid component may be used independently and may use 2 or more types together.

  A typical example of the polyol component is a dihydric alcohol. Examples of the dihydric alcohol include aliphatic diols, alicyclic diols, and aromatic diols. Examples of the aliphatic diol include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 2,4-dimethyl-2-ethylhexane-1,3-diol, 2, 2-dimethyl-1,3-propanediol (neopentyl glycol), 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, 1,3- Examples include butadiol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, and 2,2,4-trimethyl-1,6-hexanediol. It is done. Examples of the alicyclic diol include 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, spiroglycol, tricyclodecane dimethanol, adamantanediol, 2,2,4 , 4-tetramethyl-1,3-cyclobutanediol. Examples of the aromatic diol include 4,4'-thiodiphenol, 4,4'-methylenediphenol, 4,4 '-(2-norbornylidene) diphenol, 4,4'-dihydroxybiphenol, o-, m- and p-dihydroxybenzene, 4,4'-isopropylidenephenol, 4,4'-isopropylidenebis (2,6-cyclophenol) 2,5-naphthalenediol and p-xylenediol. A polyol component may be used independently and may use 2 or more types together.

  Preferred carboxylic acid components include terephthalic acid, isophthalic acid, and 2,5-naphthalenedicarboxylic acid. Preferred polyol components include ethylene glycol, diethylene glycol, triethylene glycol, 1,4-butanediol, 1,3-cyclohexanedimethanol, and 1,4-cyclohexanedimethanol.

  The structure of the polyester is determined by the combination of monomers as described above. Accordingly, preferred polyester resins include, for example, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polycyclohexylene terephthalate, and copolymers, blends and modified products thereof. It is done.

  By using such a polyester resin and applying a production method including oblique stretching, a first transparent resin having a preferable in-plane retardation and an orientation axis direction and having a superior axial accuracy. A film can be obtained.

  In the present invention, the polyester resin may be a modified PET containing a repeating unit derived from cyclohexanedimethanol. In this case, the ratio of cyclohexanedimethanol in the polyol component is preferably more than 0 mol% and 10 mol% or less, more preferably more than 0 mol% and 3 mol% or less. The polyester-based resin may be a modified PET containing a repeating unit derived from isophthalic acid. In this case, the proportion of isophthalic acid in the carboxylic acid component is preferably more than 0 mol% and 20 mol% or less, more preferably more than 0 mol% and 10 mol% or less. Needless to say, these embodiments may be combined.

  The first transparent resin film is produced as a biaxially stretched long film (long body). In the present specification, the “long shape” refers to an elongated shape having a ratio of length to width of 10 or more. The ratio of the length to the width of the first transparent resin film is preferably 30 or more, more preferably 100 or more. In one embodiment, the first transparent resin film is a long body wound in a roll shape, and in another embodiment, the first transparent resin film is a rectangular sheet. .

  The orientation axis of the first transparent resin film preferably has an angle of 10 to 45 ° with respect to the long side or the short side, more preferably 20 to 45 °, and most preferably 30 to 45 °. preferable. In the transparent conductive film laminate of the present invention, the orientation axis of the first transparent resin film is disposed at an angle of 10 to 80 ° with respect to the vibration direction of the linearly polarized light emitted from the display device. Preferably, it is arranged at an angle of 20 to 70 °, more preferably at an angle of 30 to 60 °.

  For this reason, the direction of the slow axis of the long film is in the range of 30 ° to 60 °, preferably in the range of 38 ° to 52 °, more preferably 43 over the entire width direction of the film. More preferably, the slow axis direction forms an angle of about 45 ° with respect to the longitudinal direction. The first transparent resin film can be obtained as a first transparent resin film having a slow axis in an oblique direction with excellent axial accuracy by applying a production method including oblique stretching.

  The in-plane retardation R0 of the first transparent resin film is preferably 0 to 150 nm, more preferably 10 to 130 nm, and still more preferably 20 to 110 nm, from the viewpoint of further enhancing the effect of suppressing rainbow unevenness.

  Here, the in-plane retardation R0 is an in-plane retardation of the film measured with light having a wavelength of 590 nm at 23 ° C. R0 is determined by the formula: R0 = (nx−ny) × d, where d (nm) is the thickness of the film. Here, nx is the refractive index in the direction in which the in-plane refractive index is maximum (that is, the slow axis direction), and ny is the refractive index in the direction perpendicular to the slow axis in the plane.

  The thickness direction retardation Rth of the first transparent resin film is preferably 1100 nm or less, more preferably 350 to 950 nm, and still more preferably from the viewpoint of further enhancing the effect of suppressing rainbow unevenness and obtaining sufficient strength. 400-900 nm.

  Here, the thickness direction retardation Rth is the thickness direction retardation of the film measured with light having a wavelength of 590 nm at 23 ° C. Rth is determined by the formula: Rth = (nx−nz) × d, where d (nm) is the thickness of the film. Here, nx is the refractive index in the direction in which the in-plane refractive index is maximum (that is, the slow axis direction), and nz is the refractive index in the thickness direction.

  In the present invention, the phase difference ratio R0 / Rth is also important. From the viewpoint of enhancing the effect of suppressing rainbow unevenness and obtaining sufficient strength, the phase difference ratio R0 / Rth is 0.01 to 0.5. Is preferable, 0.02-0.47 is more preferable, and 0.04-0.45 is still more preferable.

  The first transparent resin film preferably has a dimensional shrinkage after heating at 80 ° C. for 240 hours of 2.0% or less, more preferably 1.0% or less.

  The first transparent resin film preferably has a crystallinity measured by X-ray diffraction (XRD) of 25% or more, more preferably 30% or more. The upper limit of the crystallinity is, for example, 70%. When the crystallinity is in such a range, there is an advantage that the film does not shrink when the stretched film is heated, and optical properties such as retardation and orientation angle are hardly changed.

  The thickness of the first transparent resin film is preferably 5 to 50 μm, more preferably 7 to 40 μm, and more preferably 10 to 30 μm from the viewpoint of obtaining the in-plane retardation and the thickness direction retardation as described above and enhancing the handling property. Is more preferable.

  The glass transition temperature of the polyester resin is preferably 65 ° C to 80 ° C, more preferably 70 ° C to 75 ° C. If the glass transition temperature is too low, the desired dimensional shrinkage rate may not be obtained. If the glass transition temperature is excessively high, the molding stability at the time of film molding may deteriorate, and the transparency of the film may be impaired. The glass transition temperature is determined according to JIS K 7121 (1987).

  The weight average molecular weight of the polyester resin is preferably 10,000 to 100,000, more preferably 15,000 to 50,000. If it is such a weight average molecular weight, the handling at the time of shaping | molding is easy, and the film which has the outstanding mechanical strength can be obtained.

  The polyester resin can be formed into a film by any appropriate method. The obtained polyester resin film can be made into a biaxially stretched film by a method of stretching biaxially and horizontally. At that time, as disclosed in JP-A-2015-72376, a first transparent resin film having an orientation axis in an oblique direction can be suitably obtained by using a production method including oblique stretching.

  That is, the left and right end portions of the film to be stretched are each gripped by variable pitch type left and right clips whose longitudinal clip pitches change (step A: gripping step); the film is preheated (step B) : Preheating step); changing the clip pitch of the left and right clips independently and stretching the film diagonally (step C: stretching step); if necessary, the clip pitch of the left and right clips is constant In this state, the film is heat-treated to be crystallized (step D: crystallization step); and a clip that holds the film is released (step E: release step); By the manufacturing method containing, the 1st transparent resin film used by this invention can be manufactured suitably.

  The first transparent resin film is subjected to an etching process such as sputtering, corona discharge, flame, ultraviolet irradiation, electron beam irradiation, chemical conversion, oxidation, and undercoating (adhesive layer) on the first transparent resin film in advance. You may make it improve adhesiveness with the optical adjustment layer, cured resin layer, transparent conductive film, etc. which are formed in this. Moreover, before forming an optical adjustment layer etc., you may remove and clean the surface of a 1st transparent resin film by solvent washing | cleaning, ultrasonic washing | cleaning, etc. as needed.

  (Second transparent resin film)

  As the second transparent resin film, any of various plastic films having transparency can be used as long as the total retardation is within a predetermined range in relation to the first transparent resin film. .

  Examples of the plastic film material include polyesters such as polyethylene terephthalate and polyethylene naphthalate, polycycloolefin, polyacetate, polyethersulfone, polycarbonate, triacetylcellulose, polyamide, polyimide, (meth) acrylic polymer, polychlorinated Examples include vinyl, polyvinylidene chloride, polystyrene, polyvinyl alcohol, polyarylate, polyphenylene sulfide, and the like. Among these materials, it is preferable to use polycycloolefin, polycarbonate, triacetyl cellulose, polyvinyl alcohol, and cycloolefin copolymer from the viewpoint of heat resistance during sputtering and total retardation within a predetermined range. That is, the second transparent resin film preferably contains a light isotropic material.

  By making the slow axis of the second transparent resin film perpendicular to the slow axis of the first transparent resin film, the total in-plane retardation R0 is made smaller than the in-plane retardation R0 of the first transparent resin film. The value is the difference between the in-plane retardation R0 of the first transparent resin film and the in-plane retardation R0 of the first transparent resin film. Similarly, by arranging both slow axes in an oblique direction, the total in-plane phase difference R0 can be reduced, but the case where both slow axes are orthogonal is the smallest in-plane position. It becomes a phase difference.

  For this reason, from the viewpoint of bringing the total phase difference within a predetermined range, the angle at which both slow axes are arranged is preferably 45 to 90 °, more preferably 80 to 90 °, and most preferably 90 °.

  Further, in consideration of the arrangement of the slow axes of both, the in-plane retardation R0 of the second transparent resin film is preferably 0 to 300 nm from the viewpoint of making the total retardation within a predetermined range. More preferably, it is 10-260 nm, More preferably, it is 20-220 nm.

  The thickness direction retardation Rth of the second transparent resin film is preferably 0 to 200 nm, more preferably 5 to 150 nm, and still more preferably from the viewpoint of further enhancing the effect of suppressing rainbow unevenness and obtaining sufficient strength. Is 10 to 100 nm. In addition, it is also possible to use the 2nd transparent resin film which has negative phase difference Rth from a viewpoint of reducing total thickness direction phase difference Rth. The total thickness direction phase difference Rth is determined by the sum of both phase differences Rth irrespective of the arrangement angle of the slow axis.

  The thickness of the second transparent resin film is preferably 30 to 200 μm, more preferably 50 to 180 μm, and more preferably 70 to 160 μm from the viewpoint of obtaining the in-plane retardation and the thickness direction retardation as described above and enhancing the handling property. Is more preferable.

  The second transparent resin film is subjected to etching treatment such as sputtering, corona discharge, flame, ultraviolet irradiation, electron beam irradiation, chemical conversion, oxidation, and undercoating treatment (adhesive layer) on the first transparent resin film in advance. You may make it improve adhesiveness with the optical adjustment layer, cured resin layer, transparent conductive film, etc. which are formed in this. Moreover, before forming an optical adjustment layer etc., you may remove and clean the surface of a 1st transparent resin film by solvent washing | cleaning, ultrasonic washing | cleaning, etc. as needed.

(Total phase difference)
In the present invention, the in-plane retardation R0 as the total retardation of the first transparent resin film and the second transparent resin film is 0 to 150 nm, and is more preferable from the viewpoint of further enhancing the effect of suppressing rainbow unevenness. Is 10 to 130 nm, more preferably 20 to 110 nm. Here, the total retardation is determined by measuring the in-plane retardation R0 of the laminate of the slow axis of the first transparent resin film and the second transparent resin film.

The thickness direction retardation Rth as the total retardation of the first transparent resin film and the second transparent resin film is 1100 nm or less, and from the viewpoint of obtaining a sufficient strength while further enhancing the effect of suppressing rainbow unevenness, More preferably, it is 400-950 nm, More preferably, it is 350-900 nm.

  In the present invention, the ratio R0 / Rth of the retardation as the total retardation of the first transparent resin film and the second transparent resin film is also important, and the effect of suppressing rainbow unevenness is further enhanced and sufficient strength is obtained. From the viewpoint of obtaining, the phase difference ratio R0 / Rth is preferably 0.01 to 0.5, more preferably 0.02 to 0.47, and still more preferably 0.04 to 0.45.

(Adhesive layer)
The adhesive layer can be formed of a curable adhesive such as an active energy ray curable type, a thermosetting type or a natural curable type, or a pressure sensitive adhesive (adhesive). It is preferred to use. In addition, as a pressure sensitive adhesive, the adhesive mentioned later can be used.

  For the formation of the active energy ray curable adhesive layer, for example, a radical curable adhesive is suitably used. Examples of the radical curable adhesive include active energy ray curable adhesives such as an electron beam curable type and an ultraviolet curable type. In particular, an active energy ray curable adhesive that can be cured in a short time is preferable, and an ultraviolet curable adhesive that can be cured with low energy is more preferable.

  The ultraviolet curable adhesive can be roughly classified into a radical polymerization curable adhesive and a cationic polymerization adhesive. In addition, the radical polymerization curable adhesive can be used as a thermosetting adhesive.

  Examples of the curable component of the radical polymerization curable adhesive include a compound having a (meth) acryloyl group and a compound having a vinyl group. These curable components may be monofunctional or bifunctional or higher. Moreover, these curable components can be used individually by 1 type or in combination of 2 or more types. As these curable components, for example, compounds having a (meth) acryloyl group are suitable.

  Specific examples of the compound having a (meth) acryloyl group include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, and 2-methyl-2-nitro. Propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, n-pentyl (meth) acrylate, t-pentyl (meth) Acrylate, 3-pentyl (meth) acrylate, 2,2-dimethylbutyl (meth) acrylate, n-hexyl (meth) acrylate, cetyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate 4-methyl-2- Ropirupenchiru (meth) acrylate, n- octadecyl (meth) (meth) acrylic acid (1-20 carbon atoms) such as acrylates alkyl esters.

  Examples of the compound having a (meth) acryloyl group include cycloalkyl (meth) acrylate (for example, cyclohexyl (meth) acrylate, cyclopentyl (meth) acrylate, etc.), aralkyl (meth) acrylate (for example, benzyl (meth)). Acrylates), polycyclic (meth) acrylates (for example, 2-isobornyl (meth) acrylate, 2-norbornylmethyl (meth) acrylate, 5-norbornen-2-yl-methyl (meth) acrylate, 3-methyl 2-norbornylmethyl (meth) acrylate, etc.), hydroxyl group-containing (meth) acrylic acid esters (eg, hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2,3-dihydroxypropylmethyl) Butyl (meth) methacrylate), alkoxy group or phenoxy group-containing (meth) acrylic acid esters (2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-methoxymethoxyethyl (meth) acrylate), 3-methoxybutyl (meth) acrylate, ethyl carbitol (meth) acrylate, phenoxyethyl (meth) acrylate, etc.), epoxy group-containing (meth) acrylic acid esters (for example, glycidyl (meth) acrylate, etc.), halogen-containing ( (Meth) acrylic acid esters (for example, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,2-trifluoroethylethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, hexafluoropro) Le (meth) acrylate, octafluoropentyl (meth) acrylate, heptadecafluorodecyl (meth) acrylate), alkylaminoalkyl (meth) acrylates (e.g., dimethylaminoethyl (meth) acrylate, etc.) and the like.

  Moreover, as a compound which has (meth) acryloyl group other than the above, hydroxyethyl acrylamide, N-methylol acrylamide, N-methoxymethyl acrylamide (SP value 22.9), N-ethoxymethyl acrylamide, (meth) acrylamide, etc. Examples thereof include amide group-containing monomers. Moreover, nitrogen-containing monomers, such as acryloyl morpholine, etc. are mentioned.

  Examples of the curable component of the radical polymerization curable adhesive include compounds having a plurality of polymerizable double bonds such as a (meth) acryloyl group and a vinyl group, and the compound can be used as a crosslinking component. It can also be mixed with the adhesive component. Examples of the curable component that becomes such a crosslinking component include tripropylene glycol diacrylate, 1,9-nonanediol diacrylate, tricyclodecane dimethanol diacrylate, cyclic trimethylolpropane formal acrylate, dioxane glycol diacrylate, and EO. Modified diglycerin tetraacrylate, Aronix M-220 (manufactured by Toagosei Co., Ltd.), light acrylate 1,9ND-A (manufactured by Kyoeisha Chemical Co., Ltd.), light acrylate DGE-4A (manufactured by Kyoeisha Chemical Co., Ltd.), light acrylate DCP-A (kyoeisha) Chemicals), SR-531 (Sartomer), CD-536 (Sartomer) and the like. Moreover, various epoxy (meth) acrylates, urethane (meth) acrylates, polyester (meth) acrylates, various (meth) acrylate monomers, and the like are included as necessary.

  The radical polymerization curable adhesive contains the curable component, and in addition to the component, a radical polymerization initiator is added according to the type of curing. When the adhesive is used as an electron beam curable type, it is not particularly necessary that the adhesive contains a radical polymerization initiator, but when it is used as an ultraviolet curable type or a thermosetting type, radical polymerization is started. An agent is used. The usage-amount of a radical polymerization initiator is about 0.1-10 weight part normally per 100 weight part of sclerosing | hardenable components, Preferably, it is 0.5-3 weight part. Moreover, the radical polymerization curable adhesive may be added with a photosensitizer that increases the curing speed and sensitivity of the electron beam typified by a carbonyl compound, if necessary. The usage-amount of a photosensitizer is about 0.001-10 weight part normally per 100 weight part of sclerosing | hardenable components, Preferably, it is 0.01-3 weight part.

  Examples of the curable component of the cationic polymerization curable adhesive include compounds having an epoxy group or an oxetanyl group. The compound having an epoxy group is not particularly limited as long as it has at least two epoxy groups in the molecule, and various generally known curable epoxy compounds can be used. As a preferable epoxy compound, a compound having at least two epoxy groups and at least one aromatic ring in the molecule, or at least two epoxy groups in the molecule, at least one of which has an alicyclic ring. Examples thereof include a compound formed between two adjacent carbon atoms constituting it.

  In forming the adhesive layer, examples of the water-based curable adhesive include vinyl polymer, gelatin, vinyl latex, polyurethane, isocyanate, polyester, and epoxy. Such an adhesive layer composed of an aqueous adhesive can be formed as an aqueous solution coating / drying layer, etc., but when preparing the aqueous solution, a catalyst such as a crosslinking agent, other additives, and an acid can be used as necessary. Can be blended.

  As the water-based adhesive, an adhesive containing a vinyl polymer is preferably used, and the vinyl polymer is preferably a polyvinyl alcohol resin. Moreover, as a polyvinyl alcohol-type resin, the adhesive agent containing the polyvinyl alcohol-type resin which has an acetoacetyl group is more preferable from the point which improves durability. Moreover, as a crosslinking agent which can be mix | blended with a polyvinyl alcohol-type resin, the compound which has at least two functional groups reactive with a polyvinyl alcohol-type resin can be used preferably. For example, boric acid, borax, carboxylic acid compounds, alkyldiamines; isocyanates; epoxies; monoaldehydes; dialdehydes; amino-formaldehyde resins; and divalent or trivalent metal salts and oxides thereof Is mentioned.

  The adhesive that forms the curable adhesive layer may appropriately contain an additive if necessary. Examples of additives include coupling agents such as silane coupling agents and titanium coupling agents, adhesion promoters typified by ethylene oxide, additives that improve wettability with transparent protective films, acryloxy group compounds and hydrocarbons. Represented by systems (natural and synthetic resins), additives that improve mechanical strength and processability, UV absorbers, anti-aging agents, dyes, processing aids, ion trapping agents, antioxidants, tackifiers , Stabilizers such as fillers (other than metal compound fillers), plasticizers, leveling agents, foaming inhibitors, antistatic cracks, heat stabilizers, hydrolysis stabilizers, and the like.

  The adhesive coating method is appropriately selected depending on the viscosity of the adhesive and the target thickness. Examples of coating methods include reverse coaters, gravure coaters (direct, reverse and offset), bar reverse coaters, roll coaters, die coaters, bar coaters, rod coaters and the like. In addition, for coating, a method such as a dapping method can be appropriately used.

  Moreover, it is preferable that the thickness of an adhesive bond layer is 0.01-10 micrometers. More preferably, it is 0.1-5 micrometers, More preferably, it is 0.3-4 micrometers.

(Cured resin layer)
The cured resin layer was provided on the second principal surface side opposite to the first cured resin layer provided on one first principal surface side of the first transparent resin film or the second transparent resin film. And a second cured resin layer. Since the transparent resin film is easily scratched in each process such as formation of a transparent conductive film, patterning of the transparent conductive film, or mounting on an electronic device, the first cured resin is formed on both sides of the transparent resin film as described above. It is preferable to form a layer and a second cured resin layer.

  The cured resin layer is a layer obtained by curing a curable resin. As the resin to be used, those having sufficient strength as a film after forming the cured resin layer and having transparency can be used without particular limitation, but thermosetting resin, ultraviolet curable resin, electron beam curable resin, two-component Examples thereof include mixed resins. Among these, an ultraviolet curable resin that can efficiently form a cured resin layer by a simple processing operation by a curing treatment by ultraviolet irradiation is preferable.

  Examples of the ultraviolet curable resin include polyester-based, acrylic-based, urethane-based, amide-based, silicone-based, and epoxy-based resins, and include ultraviolet curable monomers, oligomers, polymers, and the like. The ultraviolet curable resin preferably used is an acrylic resin or an epoxy resin, more preferably an acrylic resin.

  The cured resin layer may contain particles. By blending the particles in the cured resin layer, ridges can be formed on the surface of the cured resin layer, and blocking resistance can be suitably imparted to the transparent conductive film.

  As said particle | grains, what has transparency, such as various metal oxides, glass, a plastics, can be especially used without a restriction | limiting. For example, inorganic particles such as silica, alumina, titania, zirconia, calcium oxide, polymethyl methacrylate, polystyrene, polyurethane, acrylic resin, acrylic-styrene copolymer, benzoguanamine, melamine, polycarbonate, and other cross-linked or uncrosslinked polymers. Examples include crosslinked organic particles and silicone particles. The particles can be used by appropriately selecting one type or two or more types, but organic particles are preferable. The organic particles are preferably acrylic resins from the viewpoint of refractive index.

  The mode particle diameter of the particles can be appropriately set in consideration of the degree of protrusion of the cured resin layer and the thickness of a flat region other than the protrusion, and is not particularly limited. In addition, from the viewpoint of sufficiently imparting blocking resistance to the transparent conductive film and sufficiently suppressing increase in haze, the mode particle diameter of the particles is preferably 0.1 to 3 μm, and preferably 0.5 to 2. 5 μm is more preferable. In the present specification, “mode particle size” refers to a particle size showing the maximum value of particle distribution, using a flow type particle image analyzer (product name “FPTA-3000S” manufactured by Sysmex). , By measuring under predetermined conditions (Sheath solution: ethyl acetate, measurement mode: HPF measurement, measurement method: total count). The measurement sample is prepared by diluting the particles to 1.0% by weight with ethyl acetate and uniformly dispersing the particles using an ultrasonic cleaner.

  The content of the particles is preferably 0.05 to 1.0 part by weight, more preferably 0.1 to 0.5 part by weight, based on 100 parts by weight of the solid content of the resin composition. More preferably, it is 1 to 0.2 parts by weight. When the content of the particles in the cured resin layer is small, there is a tendency that bulges sufficient to impart blocking resistance and slipperiness to the surface of the cured resin layer are hardly formed. On the other hand, if the content of the particles is too large, the haze of the transparent conductive film increases due to light scattering by the particles, and the visibility tends to decrease. On the other hand, when the content of the particles is too large, streaks are generated during the formation of the cured resin layer (at the time of application of the solution), and the visibility may be impaired, or the electrical characteristics of the transparent conductive film may be uneven. There is a case.

  The cured resin layer is formed by applying a resin composition containing particles, a crosslinking agent, an initiator, a sensitizer and the like to be added to each curable resin as necessary on a transparent resin film, and the resin composition contains a solvent. Is obtained by drying the solvent and curing by application of either heat, active energy rays or both. For the heat, known means such as an air circulation oven or an IR heater can be used, but it is not limited to these methods. Examples of active energy rays include, but are not limited to, ultraviolet rays, electron beams, and gamma rays.

  The cured resin layer can be formed by the wet coating method (coating method) using the above materials. For example, in the case of forming indium oxide (ITO) containing tin oxide as the transparent conductive film, the crystallization time of the transparent conductive film can be shortened if the surface of the cured resin layer that is the base layer is smooth. From this point of view, the cured resin layer is preferably formed by a wet coating method.

  The thickness of the cured resin layer is preferably 0.5 μm to 5 μm, more preferably 0.7 μm to 3 μm, and most preferably 0.8 μm to 2 μm. When the thickness of the cured resin layer is within the above range, it is possible to prevent scratches and film wrinkles in the cured shrinkage of the cured resin layer, and it is possible to prevent the visibility of a touch panel and the like from being deteriorated.

(Transparent conductive film)
The transparent conductive film can be provided on the transparent resin film, but is preferably provided on the first cured resin layer provided on the first main surface side of the transparent resin film. The constituent material of the transparent conductive film is not particularly limited as long as it contains an inorganic substance. From the group consisting of indium, tin, zinc, gallium, antimony, titanium, silicon, zirconium, magnesium, aluminum, gold, silver, copper, palladium, tungsten A metal oxide of at least one selected metal is preferably used. The metal oxide may further contain a metal atom shown in the above group, if necessary. For example, indium oxide (ITO) containing tin oxide and tin oxide (ATO) containing antimony are preferably used. When using indium oxide containing tin oxide, the content of tin oxide is preferably 1 to 20% by weight, more preferably 3 to 15% by weight in the transparent conductive film.

The thickness of the transparent conductive film is not particularly limited, but the thickness is preferably 10 nm or more in order to obtain a continuous film having good conductivity with a surface resistance of 1 × 10 ³ Ω / □ or less. When the film thickness becomes too thick, the transparency is lowered, and it is preferably 15 to 35 nm, more preferably in the range of 20 to 30 nm. When the thickness of the transparent conductive film is less than 10 nm, the electrical resistance of the film surface increases and it becomes difficult to form a continuous film. Further, when the thickness of the transparent conductive film exceeds 35 nm, the transparency may be lowered.

  The formation method of a transparent conductive film is not specifically limited, A conventionally well-known method is employable. Specific examples include dry processes such as vacuum deposition, sputtering, and ion plating. In addition, an appropriate method can be adopted depending on the required film thickness. In addition, when forming a transparent conductive film on the 1st hardening resin layer, if the transparent conductive film is formed by dry processes, such as sputtering method, the surface of a transparent conductive film is the 1st hardening which is the foundation layer The surface shape of the resin layer is substantially maintained. Therefore, when a protrusion exists in the 1st cured resin layer, blocking resistance and slipperiness can be suitably given also to the transparent conductive film surface.

  The transparent conductive film can be crystallized by applying a heat annealing treatment (for example, at 80 to 150 ° C. for about 30 to 90 minutes in an air atmosphere) as necessary. By crystallizing the transparent conductive film, the transparency and durability are improved in addition to the resistance of the transparent conductive film being reduced. The means for converting the amorphous transparent conductive film into crystalline is not particularly limited, and an air circulation oven, an IR heater, or the like is used.

  Regarding the definition of “crystalline”, a transparent conductive film in which a transparent conductive film is formed on a transparent resin film is immersed in hydrochloric acid having a concentration of 5% by weight at 20 ° C. for 15 minutes, then washed with water and dried for 15 mm. When the inter-terminal resistance is measured with a tester and the inter-terminal resistance does not exceed 10 kΩ, it is assumed that the conversion of the ITO film to crystalline is completed.

  The transparent conductive film may be patterned by etching or the like. The patterning of the transparent conductive film can be performed using a conventionally known photolithography technique. An acid is preferably used as the etching solution. Examples of the acid include inorganic acids such as hydrogen chloride, hydrogen bromide, sulfuric acid, nitric acid, phosphoric acid, organic acids such as acetic acid, mixtures thereof, and aqueous solutions thereof. For example, in a transparent conductive film laminate used for a capacitive touch panel or a matrix resistive touch panel, the transparent conductive film is preferably patterned in a stripe shape. Note that, when the transparent conductive film is patterned by etching, if the transparent conductive film is first crystallized, patterning by etching may be difficult. Therefore, it is preferable to perform the annealing treatment of the transparent conductive film after patterning the transparent conductive film.

  The transparent conductive film may be amorphous or crystalline when a carrier film described later is laminated. For example, after a protective film is bonded to a transparent conductive film in which the transparent conductive film is in an amorphous state via an adhesive layer, the film can be converted into crystalline by annealing.

  The transparent conductive film may include metal nanowires. A metal nanowire is a conductive material having a metal material, a needle shape or a thread shape, and a diameter of nanometer. The metal nanowire may be linear or curved. If a transparent conductive layer composed of metal nanowires is used, the metal nanowires can be formed into a mesh shape, so that even with a small amount of metal nanowires, a good electrical conduction path can be formed, and transparent with low electrical resistance. A conductive film laminate can be obtained. Furthermore, when the metal nanowire has a mesh shape, an opening is formed in the mesh space, and a transparent conductive film laminate having a high light transmittance can be obtained.

  Any appropriate metal can be used as the metal constituting the metal nanowire as long as it is a highly conductive metal. As a metal which comprises the said metal nanowire, silver, gold | metal | money, copper, nickel etc. are mentioned, for example. Moreover, you may use the material which performed the plating process (for example, gold plating process) to these metals. Among these, silver, copper, or gold is preferable from the viewpoint of conductivity, and silver is more preferable.

(Optical adjustment layer)
In the present invention, one or more optical adjustment layers can be further included between the first transparent resin film or the first cured resin layer and the transparent conductive film. The optical adjustment layer increases the transmittance of the transparent conductive film laminate, and when the transparent conductive film is patterned, the transmittance difference or reflection between the pattern part where the pattern remains and the opening part where the pattern does not remain. It is used to obtain a transparent conductive film laminate that can reduce the rate difference and has excellent visibility.

  The refractive index of the optical adjustment layer is preferably 1.5 to 1.8, more preferably 1.51 to 1.78, and still more preferably 1.52 to 1.75. Thereby, the transmittance | permeability difference and a reflectance difference can be reduced, and the transparent conductive film laminated body excellent in visibility can be obtained.

The optical adjustment layer is formed of an inorganic material, an organic material, or a mixture of an inorganic material and an organic material. As a material for forming the optical adjustment layer, NaF, Na ₃ AlF ₆ , LiF, MgF ₂ , CaF _2, SiO ₂ , LaF ₃ , CeF ₃ , Al ₂ O ₃ , TiO ₂ , Ta ₂ O ₅ , ZrO ₂ , Examples thereof include inorganic substances such as ZnO, ZnS, and SiO _x (x is 1.5 or more and less than 2), and organic substances such as acrylic resins, epoxy resins, urethane resins, melamine resins, alkyd resins, and siloxane polymers. In particular, it is preferable to use a thermosetting resin made of a mixture of a melamine resin, an alkyd resin, and an organic silane condensate as the organic substance. The optical adjustment layer can be formed using the above materials by a coating method such as a wet method, a gravure coating method or a bar coating method, a vacuum deposition method, a sputtering method, an ion plating method, or the like.

  The optical adjustment layer may have nanoparticles having an average particle diameter of 1 nm to 500 nm. The content of the nanoparticles in the optical adjustment layer is preferably 0.1% by weight to 90% by weight. As described above, the average particle diameter of the nanoparticles used in the optical adjustment layer is preferably in the range of 1 nm to 500 nm, and more preferably 5 nm to 300 nm. Further, the content of the nanoparticles in the optical adjustment layer is more preferably 10% by weight to 80% by weight, and further preferably 20% by weight to 70% by weight. By containing nanoparticles in the optical adjustment layer, the refractive index of the optical adjustment layer itself can be easily adjusted.

  Examples of the inorganic oxide forming the nano fine particles include fine particles such as silicon oxide (silica), hollow nano silica, titanium oxide, aluminum oxide, zinc oxide, tin oxide, zirconium oxide, and niobium oxide. Among these, fine particles of silicon oxide (silica), titanium oxide, aluminum oxide, zinc oxide, tin oxide, zirconium oxide, and niobium oxide are preferable. These may be used alone or in combination of two or more.

  The thickness of the optical adjustment layer is preferably 10 nm to 200 nm, more preferably 20 nm to 150 nm, and further preferably 30 nm to 130 nm. If the thickness of the optical adjustment layer is too small, it is difficult to form a continuous film. Moreover, when the thickness of the optical adjustment layer is excessively large, the transparency of the transparent conductive film laminate tends to be reduced or cracks tend to occur.

(Metal layer, metal wiring)
In the present invention, it is also possible to provide a metal layer or a metal wiring on the transparent conductive film. The metal wiring can be formed by etching after forming the metal layer on the transparent conductive film, but is preferably formed using a photosensitive metal paste as follows. That is, after the transparent conductive film is patterned, the metal wiring is formed by applying a photosensitive conductive paste described later on the transparent resin film or the transparent conductive film, forming a photosensitive metal paste layer, and forming a photomask. The photosensitive metal paste layer is exposed through a photomask after being laminated or brought close to each other, then developed and patterned to obtain a drying process. That is, the metal wiring pattern can be formed by a known photolithography method or the like.

  The photosensitive conductive paste preferably includes conductive particles such as metal powder and a photosensitive organic component. The material of the conductive particles of the metal powder preferably contains at least one selected from the group consisting of Ag, Au, Pd, Ni, Cu, Al, and Pt, and more preferably Ag. The volume average particle diameter of the conductive particles of the metal powder is preferably 0.1 μm to 2.5 μm.

  The conductive particles other than the metal powder may be metal-coated resin particles in which the resin particle surfaces are coated with metal. As the material of the resin particles, the above-mentioned particles are included, but an acrylic resin is preferable. The metal-coated resin particles are obtained by reacting the surface of the resin particles with a silane coupling agent and coating the surface with metal. By using the silane coupling agent, the dispersion of the resin component is stabilized, and uniform metal-coated resin particles can be formed.

The photosensitive conductive paste may further contain glass frit. The glass frit preferably has a volume average particle size of 0.1 μm to 1.4 μm, a 90% particle size of 1 to 2 μm, and a top size of 4.5 μm or less. As the composition of the glass frit is not particularly limited, Bi ₂ O ₃ is are preferably blended in a range of 30% to 70% by weight relative to the total. Examples of the oxide that may be contained in addition to Bi ₂ O ₃ may include SiO ₂ , B ₂ O ₃ , ZrO ₂ , and Al ₂ O ₃ . Na ₂ O, K ₂ O, and Li ₂ O are preferably alkali-free glass frit that is substantially free of them.

  The photosensitive organic component preferably contains a photosensitive polymer and / or a photosensitive monomer. As the photosensitive polymer, a polymer of a component selected from a compound having a carbon-carbon double bond such as methyl (meth) acrylate, ethyl (meth) acrylate, or a side chain or molecule of an acrylic resin comprising these copolymers. Those having a photoreactive group added to the terminal are preferably used. Preferred photoreactive groups include ethylenically unsaturated groups such as vinyl, allyl, acrylic and methacrylic groups. The content of the photosensitive polymer is preferably 1 to 30% by weight and 2 to 30% by weight.

  Examples of the photosensitive monomer include (meth) acrylate monomers such as methacryl acrylate and ethyl acrylate, γ-methacryloxypropyltrimethoxysilane, 1-vinyl-2-pyrrolidone and the like, and one or more are used. can do.

  In the photosensitive conductive paste, the photosensitive organic component is preferably contained in an amount of 5 to 40% by weight with respect to 100 parts by weight of the metal powder in terms of light sensitivity, and more preferably 10 to 30 parts by weight. The photosensitive conductive paste of the present invention preferably uses a photopolymerization initiator, a sensitizer, a polymerization inhibitor, and an organic solvent as necessary.

  The thickness of the metal layer is not particularly limited. For example, when the pattern wiring is formed by removing a part of the surface of the metal layer by etching or the like, the thickness of the metal layer is appropriately set so that the formed pattern wiring has a desired resistance value. Therefore, the thickness of the metal layer is preferably 0.01 to 200 μm, and more preferably 0.05 to 100 μm. When the thickness of the metal layer is within the above range, the resistance of the pattern wiring does not become too high, and the power consumption of the device does not increase. In addition, the production efficiency of the metal layer is increased, the integrated heat amount during the film formation is reduced, and the film is less likely to be thermally wrinkled.

  When the transparent conductive film laminate is a transparent conductive film laminate for a touch panel used in combination with a display, the portion corresponding to the display portion is formed by a patterned transparent conductive film and is made from a photosensitive conductive paste The metal wiring thus used is used for a wiring portion of a non-display portion (for example, a peripheral portion). The transparent conductive film may be used even in a non-display portion, and in that case, metal wiring may be formed on the transparent conductive film.

<Carrier film>
In the present invention, the transparent conductive film laminate may have a carrier film. The carrier film has an adhesive layer on at least one surface side of the protective film. A carrier film bonds a transparent conductive film laminated body which can be peeled through an adhesive layer, and the 2nd main surface side of a transparent conductive film laminated body, and forms a transparent conductive film laminated body. When peeling a carrier film from a transparent conductive film laminated body, an adhesive layer may be peeled with a protective film, and only a protective film may be peeled.

(Protective film)
As a material for forming the protective film, a material excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy and the like is preferable. As the protective film, a film made of a crystalline resin or an amorphous resin can be used.

  Examples of the crystalline resin include polyester resins such as polyethylene terephthalate and polyethylene naphthalate, polyolefin resins such as polyethylene and polypropylene, triacetyl cellulose, polyvinyl alcohol, and cycloolefin copolymers. Polyester resins are preferred.

  Examples of the amorphous resin include cycloolefin resins and polycarbonate resins, and polycarbonate resins are preferable from the viewpoint of excellent light transmittance, scratch resistance, water resistance, and good mechanical properties. Examples of the polycarbonate-based resin include aliphatic polycarbonate, aromatic polycarbonate, and aliphatic-aromatic polycarbonate.

  As with the transparent resin film, the surface of the protective film is pre-treated with an etching process such as sputtering, corona discharge, flame, ultraviolet irradiation, electron beam irradiation, chemical conversion, oxidation, or undercoating (easily adhesive layer) on the surface. You may make it improve adhesiveness with the adhesive layer of this. In addition, before forming the pressure-sensitive adhesive layer, the surface of the protective film may be removed and cleaned by solvent cleaning or ultrasonic cleaning as necessary.

  From the viewpoint of improving workability and the like, the thickness of the protective film is preferably 20 to 150 μm, more preferably 30 to 100 μm, and still more preferably 40 to 80 μm.

(Adhesive layer)
The pressure-sensitive adhesive layer can be used without particular limitation as long as it has transparency. Specifically, for example, acrylic polymers, silicone polymers, polyesters, polyurethanes, polyamides, polyvinyl ethers, vinyl acetate / vinyl chloride copolymers, modified polyolefins, epoxy systems, fluorine systems, natural rubbers, rubbers such as synthetic rubbers, etc. Those having the above polymer as a base polymer can be appropriately selected and used. In particular, an acrylic pressure-sensitive adhesive is preferably used from the viewpoint that it is excellent in optical transparency, exhibits adhesive properties such as appropriate wettability, cohesiveness and adhesiveness, and is excellent in weather resistance and heat resistance.

  The method for forming the pressure-sensitive adhesive layer is not particularly limited. The pressure-sensitive adhesive composition is applied to a release liner, dried and then transferred to a base film (transfer method), and the pressure-sensitive adhesive composition is directly applied to a protective film. And a drying method (direct copying method) and a co-extrusion method. In addition, a tackifier, a plasticizer, a filler, an antioxidant, an ultraviolet absorber, a silane coupling agent, and the like can be appropriately used as the pressure-sensitive adhesive. The preferable thickness of the pressure-sensitive adhesive layer is 5 μm to 100 μm, more preferably 10 μm to 50 μm, and more preferably 15 μm to 35 μm.

<Characteristics of transparent conductive film laminate>
In the transparent conductive film laminate of the present invention, Δx is preferably 0.15 or less, Δy is 0.20 or less, and Δx is 0.2 or less, as variations in xy color of evaluation of rainbow unevenness in Examples. More preferably, it is 13 or less and Δy is 0.17 or less.

  Further, in order to achieve this, when a transparent resin film is used alone, Δx is preferably 0.15 or less and Δy is 0.20 or less, and Δx is 0 or less, as variations in xy color specification. .13 or less and Δy is more preferably 0.17 or less.

<Touch panel>
The transparent conductive film laminate in which the carrier film or the protective film is peeled off from the transparent conductive film laminate can be suitably applied as a transparent electrode of electronic devices such as a capacitive touch panel and a resistive film touch panel, for example.

  In forming the touch panel, other base materials such as glass and a polymer film can be bonded to one or both main surfaces of the transparent conductive film laminate described above via a transparent adhesive layer. For example, you may form the laminated body by which the transparent base | substrate was bonded together through the transparent adhesive layer on the surface by which the transparent conductive film laminated body of the transparent conductive film is not formed. The transparent substrate may be composed of a single substrate film or may be a laminate of two or more substrate films (for example, laminated via a transparent adhesive layer). A hard coat layer can also be provided on the outer surface of the transparent substrate to be bonded to the transparent conductive film laminate. As described above, the pressure-sensitive adhesive layer used for bonding the transparent conductive film laminate and the substrate can be used without particular limitation as long as it has transparency.

  When the transparent conductive film laminate of the present invention is used for forming a touch panel, by using a low retardation polyester as a base material, it has sufficient material strength, the material cost is low, and the productivity is good. And the touch panel which has a transparent conductive film laminated body from which the suppression effect of sufficient rainbow nonuniformity is acquired can be provided. If it is other than a touch panel use, it can be used for the shield use which shields the electromagnetic waves and noise emitted from an electronic device.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail using an Example, this invention is not limited to a following example. In addition, the physical property etc. in an Example etc. were measured as follows.

(Phase difference)
The in-plane retardation of the transparent resin film was measured at a measurement wavelength of 590 nm in a 23 ° C. environment using a polarization / phase difference measurement system (product name “AxoScan” manufactured by Axometrics). Similarly, the phase difference was measured when the film was tilted by 40 ° with the slow axis direction and the fast axis direction as the center of rotation. In addition, the order of the measured value of the phase difference was determined so as to coincide with the wavelength dispersion of the phase difference of the transparent resin film obtained in advance. From these measured values, an in-plane retardation value (R0) and a thickness direction retardation value (Rth) of the transparent resin film were calculated.

(Measurement of thickness)
Thickness was measured with a micro gauge thickness gauge (manufactured by Mitutoyo Corporation) for those having a thickness of 1 μm or more. The thickness of less than 1 μm and the thickness of the optical adjustment layer were measured with an instantaneous multi-photometry system (MCPD2000 manufactured by Otsuka Electronics Co., Ltd.). For nano-sized thickness like the thickness of ITO film etc., FB-2000A (manufactured by Hitachi High-Technologies Co., Ltd.) is used to prepare a sample for cross-sectional observation, and cross-sectional TEM observation is HF-2000 (manufactured by Hitachi High-Technologies Corporation). Was used to measure the film thickness. The evaluation results are shown in Table 1.

(Evaluation of rainbow unevenness)
As a method for evaluating the rainbow unevenness, a variation evaluation with an xy color specification and a four-stage evaluation (◎ to ×) by silent vision were performed.

  The xy color variation was evaluated using a conoscope (manufactured by Autotronic-Melchers, Conoscope), and a commercially available polarizing plate was placed on a high-luminance backlight. A transparent conductive film is placed so that the direction of the slow axis (that is, the orientation axis) of the first transparent resin film is 45 ° with respect to the absorption axis of the first polarizing plate. The second polarizing plate is further placed on the conductive film so that the absorption axis is orthogonal to the absorption axis of the first polarizing plate, and all directions (polar angle 0 ° to 80 °, azimuth angle 0 °) The x value and the y value were measured with a conoscope from ˜360 °, and the variation in the xy color at that time was evaluated. As Δx and Δy are smaller, the rainbow unevenness is suppressed, and Δx is 0.15 or less and Δy is 0.20 or less, which is a good rainbow unevenness suppression standard.

  In addition, the four-level evaluation by silent vision is that x: the hue changes significantly with respect to the angle change, Δ: the angle range where the hue changes significantly is a range of approximately polar angle 40-60 °, ◯: The angle range in which the hue changes remarkably is in the range of approximately 40 to 50 ° polar angle, and is narrower than the above 2. A: The hue changes with respect to the angle change Almost no confirmation was made.

[Examples 1-1 to 1-8]
By changing the biaxial stretching conditions, various polyethylene terephthalates (PET) having in-plane retardation values (R0), thickness direction retardation values (Rth) and thicknesses as shown in Table 1 can be used as the first transparent resin. Prepared as a film.

  Using this as a base material, a zirconia particle-containing UV curable composition having a refractive index of 1.62 (manufactured by JSR Corporation, trade name “OPSTA Z7412”) was applied as an optical adjustment layer on one surface thereof to form a coating layer. Subsequently, the coating layer was irradiated with ultraviolet rays from the side on which the coating layer was formed, and an optical adjustment layer was formed so as to have a thickness of 100 nm.

Next, the first transparent resin film on which the optical adjustment layer is formed is put into a take-up sputtering apparatus, and an amorphous indium tin oxide layer (composition: 27 nm in thickness) is formed on the surface of the optical adjustment layer. SnO ₂ : 10 wt%) was formed to form a transparent conductive film. In this way, a transparent conductive film was produced.

  On the other hand, as the optically isotropic second transparent resin film, the in-plane retardation value (R0) is 3 nm, the thickness direction retardation value (Rth) is 100 nm, and the thickness is 40 μm. The product name “ZEONOR (registered trademark)” was prepared.

By normal solution polymerization, an acrylic polymer having a weight average molecular weight of 600,000 was obtained with butyl acrylate / acrylic acid = 100/6 (weight ratio). An acrylic pressure-sensitive adhesive was prepared by adding 6 parts by weight of an epoxy-based crosslinking agent (trade name “Tetrad C (registered trademark)”) manufactured by Mitsubishi Gas Chemical Co., Ltd. to 100 parts by weight of the acrylic polymer.
The acrylic adhesive was applied to one side of the second transparent resin film and heated at 150 ° C. for 90 seconds to form an adhesive layer having a thickness of 10 μm. Next, the surface of the pressure-sensitive adhesive layer is bonded with a silicone-treated surface of a PET release liner (thickness 25 μm) having a silicone treatment on one side, stored at 50 ° C. for 2 days, and a second transparent resin film with a release liner. Was made.

  The second transparent resin film with a release liner was peeled off from the release liner, and then bonded to the first transparent resin film on which the optical adjustment layer was formed to produce a transparent conductive film laminate. Bonding was performed so that the slow axis of the first transparent resin film and the slow axis of the second transparent resin film were at an angle of 30 °.

[Comparative Examples 1-1 to 1-10]
In Example 1-1, various polyethylene terephthalates (PET) having in-plane retardation values (R0), thickness direction retardation values (Rth) and thicknesses as shown in Table 1 are used as the first transparent resin film. A transparent conductive film laminate was produced under exactly the same conditions as in Example 1-1 except that.

  The evaluation results of the above transparent conductive film laminate are shown in Table 1.

  As the results of Table 1 show, the transparent conductive film laminates of Examples 1-1 to 1-8 have a total in-plane retardation value of 150 nm or less and a thickness direction retardation value of 1100 nm or less. Δx was 0.16 or less and Δy was 0.20 or less, and the results were also good in the silent evaluation, and sufficient rainbow unevenness suppression was possible. This means that rainbow unevenness when the display is viewed through polarized sunglasses can be suppressed. On the other hand, in Comparative Examples 1-1 to 1-10 in which the in-plane retardation value exceeds 150 nm or the thickness direction retardation value exceeds 1100 nm, at least one of Δx and Δy is large, and the result of the silent evaluation is also obtained. Unfortunately, the effect of suppressing rainbow unevenness was insufficient.

[Examples 2-1 to 2-8]
In Examples 1-1 to 1-8, instead of using the optically isotropic second transparent resin film, the same conditions except that a quarter wavelength cycloolefin resin film is used as the second transparent resin film. A transparent conductive film laminate was produced.

In addition, as a 1/4 wavelength cycloolefin resin film, an in-plane retardation value (R0) is 140 nm, a thickness direction retardation value (Rth) is 80 nm, and a thickness is 100 μm. The name “ZEONOR®”) was used. The pasting was performed so that the slow axis of the first transparent resin film and the slow axis of the second transparent resin film were at an angle of 45 °.

[Comparative Examples 2-1 to 2-10]
In Example 2-1, various polyethylene terephthalates (PET) having in-plane retardation values (R0), thickness direction retardation values (Rth) and thicknesses as shown in Table 1 are used as the first transparent resin film. A transparent conductive film laminate was produced under exactly the same conditions as in Example 2-1, except that this was done.

  Table 2 shows the evaluation results of the transparent conductive film laminate.

  As the result of Table 2 shows, since the transparent conductive film laminated body of Examples 2-1 to 2-8 has an in-plane retardation value of 150 nm or less and a thickness direction retardation value of 1100 nm or less, Δx is It was 0.16 or less, and Δy was 0.20 or less, and it was also a good result in the silent evaluation, and sufficient rainbow unevenness suppression was possible. This means that rainbow unevenness when the display is viewed through polarized sunglasses can be suppressed. On the other hand, in Comparative Examples 2-1 to 2-10 in which the in-plane retardation value exceeds 150 nm or the thickness direction retardation value exceeds 1100 nm, at least one of Δx and Δy is large, and the result of the silent evaluation is also obtained. Unfortunately, the effect of suppressing rainbow unevenness was insufficient.

[Example 3]
In Example 1-1, the transparent conductive film laminate was prepared under the same conditions as in Example 1-1 except that a cured resin layer was formed on the first transparent resin film as follows. Produced.

  First, 100 parts by weight of an ultraviolet curable resin composition (trade name “UNIDIC (registered trademark) RS29-120” manufactured by DIC Corporation) and acrylic spherical particles having a mode particle diameter of 1.9 μm (manufactured by Soken Chemical Co., Ltd.) And a curable resin composition containing spherical particles, containing 0.2 part by weight of a trade name “MX-180TA”).

  The prepared curable resin composition containing spherical particles was applied to one surface of a PET substrate (first transparent resin film) with a thickness of 50 μm to form an application layer. Next, the coating layer was irradiated with ultraviolet rays from the side on which the coating layer was formed, and a second cured resin layer was formed so as to have a thickness of 1.0 μm. A first cured resin layer was formed on the other surface of the PET substrate by the same method except that spherical particles were not added, so that the thickness was 1.0 μm. The optical adjustment layer and the transparent conductive film were formed on the surface of the first cured resin layer.

  As a result of evaluating the rainbow unevenness of the obtained transparent conductive film laminate, it has substantially the same Δx and Δy as in Example 1-1, and is also a good result in the silent evaluation, which is sufficient Rainbow unevenness suppression was possible.

[Example 4]
In Example 1-1, a transparent conductive film laminate was produced under exactly the same conditions as Example 1-1 except that an active energy ray-curable adhesive was used instead of the adhesive.

  50 parts by weight of hydroxyethylacrylamide, 30 parts by weight of methyl acrylate, 40 parts by weight of Aronix M-220 (manufactured by Toagosei Co., Ltd.) and 1.5 parts by weight of IRGACURE907 (manufactured by Ciba Japan) are mixed and stirred at 50 ° C. for 1 hour. An active energy ray-curable adhesive was obtained.

  MCD coater (manufactured by Fuji Machinery Co., Ltd.) (cell shape: honeycomb, number of gravure rolls: 1000 / inch, rotational speed 140% / line speed) is used for the first transparent resin film with the above active energy ray-curable adhesive. The adhesive layer was applied so that the thickness of the adhesive layer was 1 μm. Subsequently, the 2nd transparent resin film was bonded together through the said active energy ray hardening-type adhesive agent. Thereafter, the first transparent resin film was irradiated with ultraviolet rays (wavelength 365 nm) of a high-pressure mercury lamp from the side to cure the adhesive, and a transparent conductive film laminate was obtained.

  As a result of evaluating the rainbow unevenness of the obtained transparent conductive film laminate, it has substantially the same Δx and Δy as in Example 1-1, and is also a good result in the silent evaluation, which is sufficient Rainbow unevenness suppression was possible.

DESCRIPTION OF SYMBOLS 1 Protective film 2 Adhesive layer 3 2nd cured resin layer (anti-blocking layer)
4 First transparent resin film 5 First cured resin layer (hard coat layer)
6 Transparent conductive film 7 Optical adjustment layer 8 Adhesive layer 9 Second transparent resin film 10 Carrier film

Claims (8)

A transparent conductive film laminate having a transparent conductive film, a first transparent resin film, an adhesive layer and a second transparent resin film in this order,
The first transparent resin film is a biaxially stretched polyester resin film,
A transparent conductive film laminate having an in-plane retardation value of 150 nm or less and a thickness direction retardation value of 1100 nm or less as a total retardation of the first transparent resin film and the second transparent resin film.   2. The transparent conductive film laminate according to claim 1, wherein the first transparent resin film has an in-plane retardation value of 150 nm or less and a thickness direction retardation value of 1100 nm or less.   The transparent conductive film laminate according to claim 1, wherein the second transparent resin film contains polycycloolefin, polycarbonate, triacetyl cellulose, polyvinyl alcohol, and a cycloolefin copolymer.   The thickness of said 1st transparent resin film is 5-50 micrometers, The transparent conductive film laminated body in any one of Claims 1-3.   The first transparent resin film is a long or rectangular sheet, and the orientation axis has an angle of 10 to 45 ° with respect to the long side or the short side. The transparent conductive film laminated body of description.   The transparent conductive film laminated body of any one of Claims 1-5 which has an at least 1 layer of optical adjustment layer between said 1st transparent resin film and said transparent conductive film.   The transparent conductive film laminated body of any one of Claims 1-6 which has a cured resin layer in the at least one surface of said 1st transparent resin film or said 2nd transparent resin film. The touch panel obtained using the transparent conductive film laminated body of any one of Claims 1-7.