JP2019124913A - Laminated film and polarizing plate produced using the same - Google Patents

Abstract

To provide a transparent conductive film which suppresses rainbow spots when used in an environment with a light source having a steep emission peak, and secures high transparency and capability to present clear images.SOLUTION: A transparent conductive film is provided, comprising a transparent conductive layer provided on at least one surface of a laminated film having features (a)-(c) below and comprising a base material film and an optically isotropic layer. (a) The base material film has a rugged surface having an arithmetic mean roughness (Ra) in a range of 0.2-10 μm provided on at least one side thereof. (b) The base material film has a refractive index anisotropy (Bfnx-Bfny) in a range of 0.04-0.2. (c) An optically isotropic layer having a refractive index in a range of Bfny-0.15 to Bfnx+0.15 is provided on top of the rugged surface of the base material film, where Bfnx represents a refractive index of the base material film in a slow axis direction and Bfny represents a refractive index in a fast axis direction.SELECTED DRAWING: None

Description

  The present invention relates to a laminated film and a polarizing plate using the same.

  It has been known that when a film having birefringence, such as a polyester film, is used in the environment of a fluorescent lamp or a cold cathode tube light source, rainbow marks due to retardation occur. Therefore, a cellulose-based film having optical isotropy has been used as a protective film of a polarizer used for a liquid crystal display or the like.

Recently, a technique has been proposed for eliminating rainbow marks by combining a film having high retardation with a white light source having a continuous emission spectrum (for example, Patent Document 1, Patent Document 2 etc.), and it corresponds to polarized sunglasses. It has been put to practical use in liquid crystal displays and the like as a depolarizing film or a polarizer protective film. However, this technique is improved when using a light source having a sharp emission peak in the red region of the emission spectrum such as a cold cathode tube light source or a KSF phosphor (phosphor obtained by adding Mn to K ₂ SiF ₆ crystal). There was room for In addition, in order to ensure high retardation, the film needs to have a thickness, and there is a possibility that it can not sufficiently cope with the recent thinning of the image display apparatus.

  As a depolarizing film of a liquid crystal display using a light source having a sharp emission peak, unevenness is provided on the surface of the film having birefringence, so that λ / 4 or more is locally within a region smaller than the level visible to the naked eye. A film in which a phase difference is generated has been proposed (for example, Patent Document 3). However, such conventional techniques have a problem that the screen becomes white and the image is difficult to see in a strong external light environment with low contrast.

JP, 2011-215646, A International Publication No. 2011/162198 JP, 2017-161599, A

  The present invention has been made on the background of the problems of the prior art. That is, an object of the present invention is to provide a transparent conductive film capable of suppressing rainbow marks and ensuring high transparency and vivid image displayability when used under an environment of a light source having a sharp emission peak. It is in.

As a result of intensive investigations to achieve such an object, the present inventor has completed the present invention.
That is, the present invention includes the following aspects.
Item 1.
The transparent conductive film which has a transparent conductive layer in the at least one surface of the laminated film which has a base film and an optical isotropic layer which has the characteristic of following (a)-(c).
(A) At least one surface of the base film is an uneven surface, and the arithmetic average roughness (Ra) of the uneven surface is 0.2 to 10 μm.
(B) The refractive index anisotropy (Bfnx-Bfny) of a base film is 0.04-0.2.
(C) The optically isotropic layer is provided on the uneven surface of the base film, and the refractive index of the optically isotropic layer is Bfny-0.15 to Bfnx + 0.15.
(However, let the refractive index in the slow axis direction of the base film be Bfnx and the refractive index in the fast axis direction be Bfny)
Item 2.
A touch panel containing the transparent conductive film according to Item 1.
Item 3.
An image display apparatus comprising the touch panel according to item 2. .

  With the transparent conductive film of the present invention, when used under an environment of a light source having a sharp emission peak, etc., rainbow spots can be suppressed, and high transparency and vivid image display performance can be secured.

The present invention is a transparent conductive film having a transparent conductive layer on at least one surface of a laminated film having a substrate film of refractive index anisotropy having an irregular surface (rough surface) and an optically isotropic layer. . Hereinafter, the laminated film having the transparent conductive layer is referred to as a transparent conductive film, and when simply referred to as a laminated film, it is possible to use a substrate film of refractive index anisotropy having an uneven surface (roughened surface) and an optically isotropic layer. A laminated film is meant.
(Base film)
First, the substrate film will be described.

  There is no particular limitation on at least the base film as long as it can give refractive index anisotropy, and polyester, polyamide, polystyrene, syndiotactic polystyrene, polyamide, polycarbonate and the like can be mentioned. Above all, polyester is preferable in that a film having a high refractive index anisotropy can be easily obtained. Examples of the polyester include polyethylene terephthalate, polyethylene naphthalate, polytetramethylene terephthalate, polytrimethylene terephthalate, etc. Among them, polyethylene terephthalate and polyethylene naphthalate are preferable. These polyesters are terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, cyclohexanedicarboxylic acid, ethylene glycol as long as mechanical properties, heat resistance and dimensional stability as a film are not impaired (for example, 10 mol% or less). Diethylene glycol, trimethylene glycol, tetramethylene glycol, and ethylene oxide (EO) 1-2 mole adduct of cyclohexanedimethanol bisphenol A may be copolymerized. For example, in the case of a polymer of polyethylene terephthalate, 1 to 2 moles of a by-product diethylene glycol is usually copolymerized during polymerization, but such a by-product may be contained.

  The base film has birefringence. The lower limit of the slow axis direction refractive index (Bfnx) of the base film is preferably 1.65, more preferably 1.66, still more preferably 1.67, and particularly preferably 1.68. The upper limit of the slow axis direction refractive index (Bfnx) of the base film is preferably 1.73, more preferably 1.72, still more preferably 1.71, and particularly preferably 1.7.

  The lower limit of the fast axis axial direction refractive index (Bfny) of the base film is preferably 1.53, more preferably 1.55, still more preferably 1.56, and particularly preferably 1.57. The upper limit of the fast axis axial direction refractive index (Bfny) of the base film is preferably 1.62, more preferably 1.61, and still more preferably 1.6.

  The lower limit of the refractive index anisotropy (ΔBfNxy = Bfnx−Bfny) of the base film is preferably 0.04, more preferably 0.05, still more preferably 0.06, and particularly preferably 0.07. When the lower limit is 0.04 or more, rainbow spots can be eliminated more effectively. The upper limit of the refractive index anisotropy of the substrate film is preferably 0.2, more preferably 0.18, still more preferably 0.17, and particularly preferably 0.16. If the upper limit is 0.2 or less, the mechanical strength in the fast axis direction can be adjusted to the practical range, and the manufacture is also facilitated. In addition, the refractive index of a base film is a value measured on the conditions of wavelength 589 nm.

  The lower limit of the thickness of the base film before the provision of the uneven surface (before the roughening) is preferably 15 μm, more preferably 20 μm, and still more preferably 25 μm. If the said minimum is 15 micrometers or more, even if thickness reduces at the time of uneven | corrugated provision, it has the outstanding mechanical strength. The upper limit of the thickness of the substrate film prior to the application of the uneven surface is preferably 200 μm, more preferably 150 μm, still more preferably 100 μm, particularly preferably 90 μm, and most preferably 80 μm. If the said upper limit is 200 micrometers or less, it is excellent in the handling property and suitable for making it thin (example: it uses for a thin image display apparatus).

  The lower limit of the in-plane retardation (Re) of the substrate film before the application of the uneven surface is preferably 2000 nm, more preferably 2500 nm, still more preferably 3000 nm, particularly preferably 3500 nm, most preferably 4000 nm. It is. Rainbow spots can be eliminated more effectively if the lower limit is 2000 nm or more. The upper limit of the in-plane retardation (Re) of the substrate film before the application of the uneven surface is preferably 30000 nm, more preferably 20000 nm, still more preferably 15000 nm, still more preferably 12000 nm, particularly preferably It is 10000 nm, more particularly preferably 9000 nm, most preferably 8000 nm and most particularly preferably 7500 nm. When the upper limit is 30000 nm or less, it is suitable for thinning.

  The lower limit of the ratio (Re / Rth) of the in-plane retardation (Re) to the retardation (Rth) in the thickness direction of the substrate film prior to the application of the uneven surface is preferably 0.2, more preferably 0.5, and still more preferably Is 0.6. When the lower limit is 0.2 or more, rainbow marks can be eliminated more effectively. The upper limit of Re / Rth of the substrate film before the provision of the uneven surface is preferably 2 in view of mechanical strength, more preferably 1.5, still more preferably 1.2, and particularly preferably 1.

  The lower limit of the Nz coefficient of the substrate film is preferably 1.3, more preferably 1.4, and still more preferably 1.45. When the lower limit is 1.3 or more, mechanical strength in the fast axis direction is also excellent. The upper limit of the Nz coefficient of the substrate film is preferably 2.5, more preferably 2.2, still more preferably 2, particularly preferably 1.8, and most preferably 1.7. When the upper limit is 2.5 or less, rainbow spots can be eliminated more effectively.

  The lower limit of the plane orientation degree ΔP of the base film is preferably 0.08, more preferably 0.09, and still more preferably 0.1. If the lower limit is 0.08 or more, it is possible not only to eliminate rainbow marks more effectively, but also to reduce thickness unevenness of the film. The upper limit of the plane orientation degree ΔP of the base film is preferably 0.15, more preferably 0.14, and still more preferably 0.13. Refractive index anisotropy can be kept higher as the upper limit is 0.15 or less.

  The substrate film is preferably uniaxially oriented in order to impart refractive index anisotropy. As an orientation method, it can carry out by the usual method according to each resin. For example, in the case of extruding a molten resin in the form of a sheet on a cooling roll, a method of orienting the cooling roll by setting it at a speed equal to or higher than the speed of the extruded resin, heating an unstretched film melted and extruded. The method of stretching and orienting in the longitudinal direction with the group of rolls, and the method of heating and stretching the molten and extruded unstretched film in the tenter and stretching and orienting in the transverse direction or in the oblique direction may be mentioned.

  Among these, as a method for orienting the base film, there is a method of stretching and orienting the unstretched film which has been melted and extruded in the longitudinal direction with a heated roll group, and the unstretched film which has been melted and extruded. Preferred is a method of heating in a tenter and stretching in a lateral direction or an oblique direction for orientation. The draw ratio in the longitudinal direction is preferably 2.5 to 10 times, more preferably 3 to 8 times, and particularly preferably 3.3 to 7 times. The draw ratio in the lateral direction or oblique direction is preferably 2.5 to 10 times, more preferably 3 to 8 times, and particularly preferably 3.3 to 7 times.

  In addition, even in the case of orienting in the longitudinal direction, it is weak before stretching in the longitudinal direction (about 2.2 times or less to increase mechanical strength in the direction perpendicular to the orientation direction or adjust shrinkage characteristics. ) After stretching in the longitudinal direction, or after stretching in the longitudinal direction, weak (about 1.5 times or less) transverse stretching may be added. Similarly, even in the case of transverse orientation, it is weak before stretching in the transverse direction (about 2.2 times) in order to increase the mechanical strength in the direction perpendicular to the orientation direction or to adjust the shrinkage characteristics. The following longitudinal stretching may be added, or a weak (about 1.5 times or less) longitudinal stretching may be added after the transverse stretching. In order to further increase the orientation in the orientation direction, the film may be slightly shrunk in the longitudinal direction during or after the transverse stretching. The width after contraction is preferably 0.7 to 0.995 times, more preferably 0.8 to 0.99 times, and particularly preferably 0.9 to 0.98 times the width at the time of drawing. The stretching in the longitudinal direction and the stretching in the transverse direction may be performed by a tenter-type simultaneous biaxial stretching machine.

  The temperature at the time of stretching (and the temperature of the preheating) is preferably 80 to 150 ° C. in both the longitudinal direction and the transverse direction. Moreover, after extending | stretching, in order to ensure the heat resistance of a base film, it is preferable to heat-set at high temperature from the heating temperature at the time of extending | stretching. As a heat setting temperature, 150-250 degreeC is preferable, More preferably, it is 170-245 degreeC.

  The base film desirably has a light transmittance of 20% or less at a wavelength of 380 nm. The light transmittance at a wavelength of 380 nm is more preferably 15% or less, further preferably 10% or less, and particularly preferably 5% or less. The light transmittance at a wavelength of 380 nm is measured in the direction perpendicular to the plane of the film, and can be measured using a spectrophotometer (for example, Hitachi U-3500).

  In order to make the light transmittance at a wavelength of 380 nm of the base film 20% or less, it is desirable to appropriately adjust the type, concentration, and thickness of the base film of the ultraviolet absorber blended in the base film. As a ultraviolet absorber used by this invention, an organic type ultraviolet absorber and an inorganic type ultraviolet absorber are mentioned. From the viewpoint of transparency, organic UV absorbers are preferred. Examples of the organic ultraviolet absorber include benzotriazole type, benzophenone type, cyclic imino ester type and the like, and combinations thereof, but there is no particular limitation as long as it is within the above-mentioned range of light transmittance. From the viewpoint of durability, benzotriazoles and cyclic imino esters are particularly preferred. When two or more types of ultraviolet absorbers are used in combination, ultraviolet rays of different wavelengths can be absorbed simultaneously, so that the ultraviolet absorption effect can be further improved.

It is also preferable to add various additives to the base film, as long as the effects of the present invention are not impaired, in addition to the ultraviolet light absorber. Additives include, for example, inorganic particles, heat resistant polymer particles, alkali metal compounds, alkaline earth metal compounds, phosphorus compounds, antistatic agents, light stabilizers, flame retardants, thermal stabilizers, antioxidants, antigelling agents And surfactants. These additives can be used alone or in combination of two or more.
Moreover, in order to exhibit high transparency, it is also preferable not to contain particle | grains in a base film substantially. The phrase "does not substantially contain particles" means, for example, in the case of inorganic particles, 50 ppm or less, preferably 10 ppm or less, particularly preferably the detection limit or less, when the inorganic element in the substrate film is quantified by fluorescent X-ray analysis. Mean the content of

(Surface irregularities)
In the present invention, an uneven surface is provided on at least one side of the substrate film. The uneven surface may be provided on only one side of the substrate film, or may be provided on both sides. In addition, the base film which has an uneven surface may be called the roughened base film.

  The lower limit of the arithmetic average roughness (Ra) of the irregular surface of the roughened substrate film is preferably 0.2 μm, more preferably 0.4 μm, still more preferably 0.6 μm, particularly preferably 0.7 μm Most preferably 0.8 μm. The upper limit of the Ra is preferably 10 μm, more preferably 7 μm, still more preferably 5 μm, particularly preferably 4 μm, and most preferably 3 μm.

  The lower limit of the root mean square roughness (Rq) of the irregular surface of the roughened base film is preferably 0.3 μm, more preferably 0.5 μm, still more preferably 0.7 μm, particularly preferably 0.9 It is μm, most preferably 1 μm. The upper limit of the Rq is preferably 13 μm, more preferably 10 μm, still more preferably 7 μm, particularly preferably 5 μm, and most preferably 4 μm.

  The lower limit of the ten-point average roughness (Rz) of the irregular surface of the roughened base film is preferably 1.0 μm, more preferably 2.0 μm, still more preferably 3.0 μm, and particularly preferably 3.5 It is μm, most preferably 4.0 μm. The upper limit of the Rz is preferably 15 μm, more preferably 12 μm, still more preferably 10 μm, and particularly preferably 8 μm.

  The lower limit of the maximum height (Ry) of the rough surface of the roughened base film is preferably 2.0 μm, more preferably 3.0 μm, still more preferably 4.0 μm, and particularly preferably 4.5 μm. And most preferably 5.0 μm. The upper limit of the Ry is preferably 20 μm, more preferably 17 μm, still more preferably 15 μm, and particularly preferably 13 μm.

  The lower limit of the maximum peak height (Rp) of the uneven surface of the roughened base film is preferably 1.0 μm, more preferably 1.5 μm, still more preferably 2.0 μm, and particularly preferably 2.5 μm. is there. The upper limit of the Rp is preferably 15 μm, more preferably 12 μm, still more preferably 10 μm, and particularly preferably 8 μm.

  The lower limit of the maximum valley depth (Rv) of the uneven surface of the roughened base film is preferably 1.0 μm, more preferably 1.5 μm, still more preferably 2.0 μm, and particularly preferably 2.5 μm. It is. The upper limit of the Rv is preferably 15 μm, more preferably 12 μm, still more preferably 10 μm, and particularly preferably 8 μm.

  When the values of Ra, Rq, Rz, Ry, Rp, and Rv are at least the lower limit, rainbow marks can be eliminated more effectively. When the values of Ra, Rq, Rz, Ry, Rp, and Rv are the upper limit or more, the productivity is excellent. Ra, Rq, Rz, Ry, Rp, and Rv are calculated from the roughness curve measured using a contact-type roughness meter in accordance with JIS B0601-1994 or JIS B0601-2001.

  By providing unevenness (roughening) on the surface of the substrate film, a retardation difference is provided in a very small area, and although coloring (rainbow spots) due to retardation in each area is made, the coloring is visually obscured be able to. The retardation difference ΔRe can be expressed by ΔRe = Ra × ΔBfNxy. The lower limit of ΔRe is preferably 30 nm, more preferably 50 nm, still more preferably 70 nm, particularly preferably 90 nm, and most preferably 100 nm. Rainbow spots can be eliminated more effectively if the lower limit is 30 nm or more. The upper limit of ΔRe is preferably 1500 nm, more preferably 1000 nm, still more preferably 800 nm, particularly preferably 500 nm, and most preferably 300 nm. When the upper limit is 1,500 nm or less, productivity is also excellent.

  The lower limit of the average spacing (Sm) of the unevenness of the roughened substrate film is preferably 5 μm, more preferably 10 μm, still more preferably 15 μm, particularly preferably 20 μm, and most preferably 25 μm. It is. When the lower limit is 5 μm or more, the slope of the unevenness becomes gentle and the image becomes clearer. The upper limit of the average spacing (Sm) of the unevenness of the roughened substrate film is preferably 500 μm, more preferably 450 μm, still more preferably 400 μm, particularly preferably 350 μm, and most preferably 300 μm. It is. When the upper limit is 500 μm or less, it is possible to prevent the coloring or flickering due to the retardation of each of the minute regions. Sm is calculated from a roughness curve measured using a contact-type roughness meter in accordance with JIS B0601-1994.

The base film may be thinner than the original thickness by providing the unevenness and roughening. The lower limit of the thickness of the roughened substrate film is preferably 10 μm, more preferably 15 μm, still more preferably 20 μm, particularly preferably 25 μm, and most preferably 30 μm. The intensity | strength as a protective film can fully be ensured as the said minimum is 10 micrometers or more. The upper limit of the thickness of the roughened substrate film is preferably 150 μm, more preferably 120 μm, still more preferably 100 μm, particularly preferably 90 μm, and most preferably 80 μm. The upper limit of 150 μm or less is suitable for thinning.
The roughened base film is embedded by embedding the roughened base film in an epoxy resin, and cutting a section of the cross section for microscopic observation, and the uneven surface is based on the center of the convex portion and the concave portion of the field of view The thickness of 10 points is measured at equal intervals, and it is calculated as the average value.

  The lower limit of the in-plane retardation (Re) of the roughened substrate film is preferably 2000 nm, more preferably 2500 nm, still more preferably 3000 nm, particularly preferably 3500 nm, and most preferably 4000 nm. It is. Rainbow spots can be eliminated more effectively if the lower limit is 2000 nm or more. The upper limit of the in-plane retardation (Re) of the roughened base film is preferably 30000 nm, more preferably 20000 nm, still more preferably 15000 nm, still more preferably 12000 nm, particularly preferably 10000 nm. More preferably, it is 9000 nm, most preferably 8000 nm, and most preferably 7500 nm. When the upper limit is 30000 nm or less, it is suitable for thinning.

There are no particular limitations on the method for providing the surface asperity, and there may be mentioned conventionally known methods of surface roughening. For example, sand blasting treatment, sand paper or file, treatment with grindstone etc., treatment with sander (orbital sander, random sander, delta sander, belt sander, disc sander, roll sander etc), treatment with metal brush etc, chemical etching, mold And molding by pressing at Among these, sand blast treatment, treatment with a sander, and chemical etching are preferable.
The sandblasting process may be, for example, a method of supplying a roll-like base film to a centrifugal blast machine and projecting an abrasive onto the base film surface. In this case, the roughness can be adjusted by the type of abrasive, the size of the abrasive, the processing time, the speed of the rotary blade, and the like. Moreover, a sandblasting process may be the method of affixing a base film to a glass plate, setting to air blast, and spraying an abrasives on a base film surface. In this case, the roughness can be adjusted by the type of abrasive, the size of the abrasive, the blowing pressure, the processing time, and the like.
The processing by the sander is, for example, a method of guiding a roll-like base film to a conveyance device having a roll of sanding paper attached to the roll surface of a part of the film conveyance roll (roll sander). Good. In this case, the roughness can be adjusted by the type of sanding paper, the number of revolutions of the roll sander, the transport speed of the film, and the like. Also, the processing direction can be adjusted by the holding angle between the roll sander and the film, the number of rotations of the roll sander, the transport speed of the film, and the like.
In the sander processing, a urethane foam is attached to a glass plate, and a base film is further attached thereon, and the base film surface is vertically, horizontally, and diagonally (45 degrees, 135 degrees) in a total of four directions using a sander. It may be a method of processing from. The roughness can be adjusted depending on the type of sanding disc, processing time, etc.
In the sander treatment and sandblast treatment, the treated surface may be further polished with sand paper or the like in order to remove local protrusions.
The chemical etching may be a method in which the film is dipped in an acid or alkaline solution and washed with water, and then the masking film is peeled off and dried. The roughness can be adjusted by the immersion time or the like. Although chemical etching is basically double-sided processing, in the case of processing only one side, for example, a masking film is attached to one side of the base film.

(Optical isotropic layer)
It is preferable that the optically isotropic layer is provided on the uneven surface of the base film. The optically isotropic layer is preferably provided in contact with the uneven surface. "Provided in contact with" means that it is provided in direct contact with the uneven surface without interposing another layer. However, an easy adhesion layer may be provided to improve the adhesion between the uneven surface and the optically isotropic layer. The thickness of the easy adhesion layer is preferably a thickness which can not be detected optically, preferably 100 nm or less, more preferably 50 nm or less, and particularly preferably 20 nm or less. If the easily bonding layer satisfies the range of the refractive index of the following optically isotropic layer, the easily bonding layer and the optically isotropic layer provided thereon are regarded as one optically isotropic layer. be able to. In addition, if the easily bonding layer has a sufficient thickness as an optically isotropic layer, the easily bonding layer may be regarded as an optically isotropic layer. By providing the optically isotropic layer, irregular reflection due to the unevenness of the surface of the base film can be reduced, and transparency can be ensured. In addition, the preferable refractive index of the easily bonding layer is the same as the range of the preferable refractive index of the following optical isotropic layer, and the adjustment method of the refractive index is also the same.

The lower limit of the refractive index of the optically isotropic layer is preferably Bfny-0.15, more preferably Bfny-0.12, still more preferably Bfny-0.1, still more preferably Bfny-0.08, particularly preferably Bfny, most preferably Bfny + 0.02.
The upper limit of the refractive index of the optically isotropic layer is preferably Bfnx + 0.15, more preferably Bfnx + 0.12, still more preferably Bfnx + 0.1, still more preferably Bfnx + 0.08, particularly preferably It is Bfnx, most preferably Bfnx-0.02.
By setting the above-mentioned range, it is possible to maintain the contrast or the sharpness of the image and to suppress the phenomenon that the screen becomes whitish when strong external light is received.

  The lower limit of the refractive index of the optically isotropic layer is preferably 1.44, more preferably 1.47, still more preferably 1.49, still more preferably 1.51, and particularly preferably It is 1.53, more preferably 1.55, most preferably 1.57, most preferably 1.59. The upper limit of the refractive index of the optically isotropic layer is preferably 1.85, more preferably 1.83, still more preferably 1.80, still more preferably 1.78, particularly preferably It is 1.76, more particularly preferably 1.74, most preferably 1.72, most preferably 1.70 and most particularly preferably 1.68. By setting the above-mentioned range, it is possible to maintain the contrast or the sharpness of the image and to suppress the phenomenon that the screen becomes whitish when strong external light is received. The refractive index of the optically isotropic layer is also a value measured under the condition of wavelength 589 nm.

The composition of the optically isotropic layer is not particularly limited, but acrylic, polystyrene, polyester, polycarbonate, polyurethane, epoxy resin, thioepoxy resin and the like are preferable. By appropriately adjusting the composition, it is possible to set the refractive index within the above range. For example, in the case of PMMA (polymethyl methacrylate), the refractive index is generally about 1.49. Acrylic pressure sensitive adhesives often introduce long chain or branched alkyl groups, and the refractive index is further lowered. In order to increase the refractive index, it is effective to copolymerize an acrylic monomer having an aromatic group or to copolymerize styrene.
Introduction of sulfur, bromine, fluorene group or the like into a polymer or resin is also a preferable method for raising the refractive index, and an acrylic copolymerized with a monomer containing these, a fluorene group-containing polyester, a fluorene group-containing polycarbonate, A thioepoxy resin is preferable as the high refractive index resin.

Further, addition of high refractive fine particles in a polymer or resin is also a suitable method of adjusting the refractive index.
The refractive index of the high refractive fine particles is preferably 1.60 to 2.74. Examples of the high refractive particles include fine particles of TiO ₂ , ZrO ₂ , CeO ₂ , Al ₂ O ₃ , BaTiO ₃ , Nb ₂ O ₅ , and SnO ₂ . The high refractive fine particles preferably have an average primary particle diameter of 3 nm to 100 nm as measured by TEM (transmission electron microscopy). These high refractive particles may be used alone or in combination of two or more.
In the specification, “average primary particle size” or “average particle size of primary particles” refers to 50% particle size of volume accumulation. More specifically, 200 primary particles are observed with an appropriate magnification by microscopic observation, each diameter is measured to calculate its volume, and 50% particle diameter of its volume accumulation is taken as the average primary particle diameter. Do.

  The optically isotropic layer is preferably crosslinked and cured. The curing method is not particularly limited, and thermal curing, radiation curing such as ultraviolet light, electron beam and the like are preferable. Examples of the crosslinking agent for curing include isocyanate compounds, epoxy compounds, carbodiimides, oxazoline compounds, amino resins such as melamine, polyfunctional acrylates, and the like.

  The optically isotropic layer is formed by applying a coating agent comprising the above components to the irregular surface of the substrate film, transferring an optically isotropic layer prepared by applying to a release film to the irregular surface of the substrate film, or the like The optically isotropic layer provided on the film of (1) can be laminated by a method such as bonding to the uneven surface of the base film. In this case, the coating agent is preferably dissolved or diluted with a solvent to have a viscosity that facilitates coating. The coating agent may be a non-solvent as long as it is a radiation curing type coating agent such as acrylic.

  For example, acrylic or other radiation curing type coating agents usually contain a photopolymerizable compound.

  As a photopolymerizable compound, a photopolymerizable monomer, a photopolymerizable oligomer, and a photopolymerizable polymer are mentioned, These can be adjusted suitably and can be used. As the photopolymerizable compound, a combination of a photopolymerizable monomer and a photopolymerizable oligomer or a photopolymerizable polymer is preferable.

Photopolymerizable Monomer The photopolymerizable monomer is one having a weight average molecular weight of less than 1000. As the photopolymerizable monomer, a polyfunctional monomer having two or more (that is, bifunctional) photopolymerizable functional groups is preferable. In the present specification, the "weight average molecular weight" is a value obtained by dissolving in a solvent such as THF and the like, and converting to polystyrene by a gel permeation chromatography (GPC) method known to date.

  Examples of the polyfunctional monomer include tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, and di Pentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol Penta (meth) acrylate, tripentaerythritol octa (meth) acrylate, tetrapentaerythritol deca (meth) acrylate, iso Anuric acid tri (meth) acrylate, isocyanuric acid di (meth) acrylate, polyester tri (meth) acrylate, polyester di (meth) acrylate, bisphenol di (meth) acrylate, diglycerin tetra (meth) acrylate, adamantyl di (meth) Acrylate, isoboronyl di (meth) acrylate, dicyclopentadi (meth) acrylate, tricyclodecane di (meth) acrylate, and those obtained by modifying these with PO, EO or the like.

  Among these, pentaerythritol triacrylate (PETA), dipentaerythritol hexaacrylate (DPHA), pentaerythritol tetraacrylate (PETTA), dipentaerythritol pentaacrylate (DPPA) and the like are preferable from the viewpoint of obtaining a functional layer having high hardness.

Photopolymerizable Oligomer The photopolymerizable oligomer is one having a weight average molecular weight of 1,000 or more and less than 10,000. As a photopolymerizable oligomer, a bifunctional or higher polyfunctional oligomer is preferable. As a polyfunctional oligomer, polyester (meth) acrylate, urethane (meth) acrylate, polyester-urethane (meth) acrylate, polyether (meth) acrylate, polyol (meth) acrylate, melamine (meth) acrylate, isocyanurate (meth) Acrylate, epoxy (meth) acrylate, etc. are mentioned.

Photopolymerizable Polymer The photopolymerizable polymer has a weight average molecular weight of 10000 or more, and the weight average molecular weight is preferably 10000 or more and 80000 or less, and more preferably 10000 or more and 40000 or less. When the weight average molecular weight exceeds 80000, the coating suitability is lowered because the viscosity is high, and the appearance of the obtained laminated film may be deteriorated. As the photopolymerizable polymer, a bifunctional or higher polyfunctional polymer is preferable. As a polyfunctional polymer, urethane (meth) acrylate, isocyanurate (meth) acrylate, polyester-urethane (meth) acrylate, epoxy (meth) acrylate etc. are mentioned.

  The coating agent may contain, in addition to the components described above, a polymerization initiator, a catalyst for a crosslinking agent, a polymerization inhibitor, an antioxidant, an ultraviolet light absorber, a leveling agent, a surfactant, and the like.

  In addition, the optical isotropic layer composition is extruded and laminated on the irregular surface of the substrate film, and the optical isotropic layer composition is melted and extruded between the irregular surface of the substrate film and another film. And laminating are also preferable.

  The optically isotropic layer has the function of reducing irregular reflection of the uneven surface by being provided on the uneven surface, but may have other functions as well. The optically isotropic layer may have, for example, functions of a hard coat layer, an antireflective layer, an antiglare layer, an antistatic layer, and the like. The optically isotropic layer may be another film or sheet, a pressure-sensitive adhesive layer for bonding to a component of the apparatus, or an adhesive layer.

The lower limit of the thickness of the optically isotropic layer is preferably 0.5 μm, more preferably 1.0 μm, still more preferably 2 μm, particularly preferably 3 μm, and most preferably 4 μm. The unevenness | corrugation of a base film can be planarized, a haze can be reduced as the said thickness is 0.5 micrometer or more, and sharpness can be improved.
The upper limit of the thickness of the optically isotropic layer is preferably 30 μm, more preferably 25 μm, still more preferably 20 μm, particularly preferably 15 μm, and most preferably 10 μm. It is suitable for thickness reduction that the said thickness is 30 micrometers or less.
The thickness of the optically isotropic layer is a value obtained by subtracting the thickness of the roughened base film from the thickness of the laminated film described later.

  The upper limit of the in-plane retardation of the optically isotropic layer is preferably 50 nm, more preferably 30 nm, still more preferably 10 nm, particularly preferably 5 nm, from the viewpoint of suppressing the occurrence of rainbow marks.

  The upper limit of the refractive index difference between the refractive index in the direction of the highest refractive index of the optically isotropic layer and the refractive index in the direction of the lowest refractive index is preferably 0.01 from the viewpoint of suppressing the occurrence of rainbow marks Preferably it is 0.007, more preferably 0.005, particularly preferably 0.003 and most preferably 0.002.

(Laminated film)
The lower limit of the thickness of the laminated film is preferably 12 μm, more preferably 15 μm, still more preferably 18 μm, and particularly preferably 20 μm. When the lower limit is 12 μm or more, the strength of the laminated film is excellent, and the handling of production or subsequent processing becomes easy.
The upper limit of the thickness of the laminated film is preferably 180 μm, more preferably 150 μm, still more preferably 120 μm, particularly preferably 100 μm, and most preferably 90 μm. When the upper limit is 180 μm or less, it is suitable for thinning in various applications.
The thickness of the laminated film is calculated by embedding the laminated film in an epoxy resin, cutting out a section of the cross section, observing under a microscope, measuring the thickness of 10 points at regular intervals, and calculating the average value thereof.

  The upper limit of the haze of the laminated film is preferably 10%, more preferably 7%, still more preferably 5%, particularly preferably 4%, most preferably 3%, and most preferably Is 2.5%, most preferably 2%. When the upper limit is 10% or less, it is possible to more effectively suppress the reduction in contrast and the whitening of the screen when strong external light is received.

  In the laminated film, only one side of the substrate film may be an uneven surface, but when the ΔRe of the substrate film is relatively low or the roughness of the unevenness is relatively small and the rainbow spots are not sufficiently eliminated Preferably, the uneven surface and the optically isotropic layer are provided on both sides.

The laminated film of the present invention may have two or more base films having an irregular surface (rough surface), may have two or more optically isotropic layers, and may have an irregular surface (rough You may have films or layers other than the base film which has a planarizing surface, and an optical isotropic layer.
Examples of lamination include the following types 1 to 4 and the like.
(Type 1) base film (concave / convex surface) / optical isotropic layer (adhesive or pressure sensitive adhesive) / other film (type 2) base film (concave / convex surface) / optical isotropic layer (adhesive or pressure sensitive adhesive) / (Concave surface) base film (type 3) base film (concave surface) / optical isotropic layer (adhesive or pressure sensitive adhesive) / other film / optical isotropic layer (adhesive or pressure sensitive adhesive) / (concave or convex surface Surface) Base film (Type 4) Other film / Optical isotropic layer (adhesive or pressure sensitive adhesive) / (concave / convex surface) Base film (concave / convex surface) / Optical isotropic layer (adhesive or pressure sensitive adhesive) / others When the ΔBfNxy of the substrate film of refractive index anisotropy is relatively small or the roughness of the unevenness is relatively small, it is preferable to adopt the configuration of type 2 to type 4. In addition, in description of the use of the laminated film of the following this invention, etc., when calling it a laminated film, the structure of said type 1-4 shall also be included. In the case of type 2 to type 4, the slow axes of the two base films are preferably parallel or perpendicular to each other, and preferably parallel for ease of production. Here, “parallel or perpendicular” is acceptable from 0 degrees or 90 degrees to preferably ± 10 degrees, further ± 7 degrees, particularly ± 5 degrees.

  In the specification, when the term "pressure-sensitive adhesive" or "pressure-sensitive adhesive layer" is used, a target is coated with a coating agent for pressure-sensitive adhesive and crosslinked or dried, or a substrateless optical pressure-sensitive adhesive is transferred. Means

(Transparent conductive layer)
The transparent conductive layer is provided on at least one surface of the laminated film, and may be a base film surface or an optical isotropic layer surface. It may be provided on both sides. The transparent conductive layer is not particularly limited, and examples thereof include mesh printed matter of conductive paste, carbon nanotube-containing coat, self-assembled nano silver coat, needle-like conductive filler-containing coat, and metal oxide thin film. Among them, metal oxide thin films are preferable, and thin films of indium oxide, zinc oxide, tin oxide, indium tin oxide (ITO), tin antimony oxide, zinc aluminum oxide, indium zinc oxide and the like are preferable.

  The transparent conductive layer is preferably formed in a pattern of lines or grids by etching.

Hereinafter, the most preferable ITO thin film will be described in detail as an example.
The thickness of the transparent conductive layer is preferably 5 to 500 nm, more preferably 15 to 250 nm, and still more preferably 20 to 100 nm. According to the above thickness, it is possible to suppress the color caused by the conductive layer while securing the conductivity.

  The transparent conductive layer can be formed by a known method such as a vacuum evaporation method, a sputtering method, a CVD method, an ion plating method, a spray method or a sol-gel method.

  After forming the transparent conductive layer, a resist mask having a predetermined pattern is formed by photolithography, and then etching treatment may be performed to form a pattern or the like.

  The transparent conductive layer may be amorphous, but the obtained transparent conductive layer is heat treated at 130 to 180 ° C. for 0.5 to 2 hours to grow crystals to make the conductive layer crystalline and conductive. It is preferable to increase the property.

  It is also preferable to provide a hard coat layer and a refractive index adjustment layer as the lower layer of the conductive layer. The refractive index adjustment layer has the effect of making it difficult to see the pattern after etching. The refractive index adjustment layer may be a layer having a refractive index close to that of the conductive layer (high refractive index layer), and the high refractive index layer and the low refractive index layer are in this order (the high refractive index layer is closer to the transparent conductive layer) You may provide in order of becoming a position. In particular, it is preferable to provide a high refractive index layer and a low refractive index layer in this order.

(High refractive index layer)
The high refractive index layer may be provided directly on the substrate film and / or the optically isotropic layer, or via another film or layer (for example, an easy adhesion layer, a hard coat layer). The high refractive index layer is preferably a layer inside the low refractive index layer. The high refractive index layer may further have other functions and may be an optically isotropic layer.

  The refractive index of the high refractive index layer is preferably 1.55 to 1.85, more preferably 1.56 to 1.80, and still more preferably 1.56 to 1.75. The refractive index of the high refractive index layer is a value measured under the condition of wavelength 589 nm.

  The thickness of the high refractive index layer is generally in the range of 20 to 2 μm, and it is suitable for the case where it is difficult to see the pattern only with the high refractive index layer or the case where the pattern is difficult to see in combination with the flat refractive index layer The thickness can be adjusted appropriately. The thickness of the high refractive index layer is preferably 20 to 200 nm, more preferably 30 to 190 nm, and more preferably 50 to 180 nm based on the concept of canceling the reflection of the interface by the thickness and refractive index of each refractive index layer. preferable. The high refractive index layer may be a plurality of layers, but two layers or less are preferable, and a single layer is more preferable. In the case of a plurality of layers, the total thickness of the plurality of layers is preferably the above thickness.

  When two high refractive index layers are used, it is preferable to further increase the refractive index of the high refractive index layer on the low refractive index layer side, and specifically, the refraction of the high refractive index layer on the low refractive index layer side The index is preferably 1.60 to 1.85, and the refractive index of the other high refractive index layer is preferably 1.55 to 1.70.

  The high refractive index layer is preferably made of a resin composition containing the particles and the resin mentioned in the optically isotropic layer. Among them, as high refractive index particles, antimony pentoxide particles (1.79), zinc oxide particles (1.90), titanium oxide particles (2.3 to 2.7), cerium oxide particles (1.95), Tin-doped indium oxide particles (1.95 to 2.00), antimony-doped tin oxide particles (1.75 to 1.85), yttrium oxide particles (1.87), and zirconium oxide particles (2.10) are preferred. . In the above parentheses, the refractive index of the material of each particle is shown. Among these, titanium oxide particles and zirconium oxide particles are preferable.

  In one embodiment, high refractive particles may be used in combination of two or more. In particular, addition of the first high refractive index particles and the second high refractive index particles having a smaller surface charge amount is also preferable in order to prevent aggregation. In addition, it is preferable that the high refractive index particles are surface-treated from the viewpoint of dispersibility.

  5-200 nm is preferable, as for the average particle diameter of the primary particle of high refractive particle | grains, 5-100 nm is more preferable, and 10-80 nm is more preferable.

  The content of the high refractive particles is preferably 30 to 400 parts by mass, more preferably 50 to 200 parts by mass, and 80 to 150 parts by mass with respect to 100 parts by mass of the resin composition. More preferable.

  In one embodiment, the high refractive index layer is preferably provided by the dry process mentioned in vapor deposition or film formation of ITO. In the case of the dry process, a composite oxide containing at least one selected from the group consisting of Ta, Nb, Zr and Ti and Si is preferable. For example, a composite oxide of Nb and Si, a composite oxide of Ti and Si, a composite oxide of Zr and Si, a composite oxide of Ta and Si, etc. may be mentioned. When the high refractive index layer is provided by a dry process, the refractive index of the high refractive index layer is preferably 1.60 to 1.95, and more preferably 1.65 to 1.90. In the case of a dry process, the thickness of the high refractive index layer is preferably 5 to 50 nm, more preferably 10 nm to 40 nm.

The thickness of the high refractive index layer may be appropriately adjusted in consideration of the refractive index and thickness of the low refractive index layer, the refractive index of the high refractive index layer, the thickness of the transparent conductive layer, and the refractive index in both wet process and dry process. it can.
(Low refractive index layer)
In one embodiment, it is preferable to further provide a low refractive index layer on the high refractive index layer. As a method of providing the low refractive index layer on the high refractive index layer, a method of coating the low refractive index layer composition on the high refractive index layer is preferable.

The refractive index of the low refractive index layer is preferably 1.50 or less, preferably 1.46 or less, preferably 1.45 or less, and more preferably 1.42 or less. Moreover, 1.20 or more is preferable and, as for the refractive index of a low-refractive-index layer, 1.25 or more is more preferable.
The refractive index of the low refractive index layer is a value measured under the condition of wavelength 589 nm.

  Although the thickness of the low refractive index layer is not limited, it is preferably 5 to 120 nm, more preferably 10 to 100 nm, and particularly preferably 15 to 70 nm.

  The low refractive index layer may be a single layer or two or more layers. When two or more low refractive index layers are provided, the refractive index and thickness of each low refractive index layer may be the same as or different from each other, but are preferably different from each other.

  The low refractive index layer is preferably (1) a layer comprising a resin composition containing low refractive index particles, (2) a layer comprising a fluorine resin which is a low refractive index resin, (3) silica or magnesium fluoride And (4) thin films of low refractive index substances such as silica, magnesium fluoride and the like.

  Examples of low refractive index particles include silica, magnesium fluoride and the like, among which hollow silica fine particles are preferable. Such hollow silica fine particles can be produced, for example, by the production method described in the example of JP-A-2005-099778.

  The average particle diameter of the primary particles of the low refractive index particles is preferably 5 to 200 nm, more preferably 5 to 100 nm, and still more preferably 10 to 80 nm.

  The low refractive index particle is more preferably one that has been surface-treated with a silane coupling agent, and in particular, one that is surface-treated with a silane coupling agent having a (meth) acryloyl group.

  The content of low refractive index particles in the low refractive index layer is preferably 10 to 250 parts by mass, more preferably 50 to 200 parts by mass, and still more preferably 100 to 180 parts by mass with respect to 100 parts by mass of the binder resin.

  As a binder resin used when providing a high refractive index layer and / or a low refractive index layer by coating, polyester, polyurethane, polyamide, a polycarbonate, and an acryl can be mentioned. Among them, acryl is preferable, and one obtained by polymerizing (crosslinking) a photopolymerizable compound by light irradiation is preferable.

  Examples of the photopolymerizable compound include photopolymerizable monomers, photopolymerizable oligomers, and photopolymerizable polymers, and these can be appropriately prepared and used. As the photopolymerizable compound, a combination of a photopolymerizable monomer and a photopolymerizable oligomer or a photopolymerizable polymer is preferable. Specifically, those listed as the optically isotropic layer can be used.

  In one embodiment, the high refractive index layer and / or the low refractive index layer is obtained by, for example, applying the resin composition containing the fine particles and the photopolymerizable compound to a substrate film and / or an optically isotropic layer and drying it. After that, the coating film-like resin composition can be formed by irradiating light such as ultraviolet light to polymerize (crosslink) the photopolymerizable compound.

  A thermoplastic resin, a thermosetting resin, a solvent, and a polymerization initiator may be added to the high refractive index layer and / or the low refractive index layer, as necessary. Furthermore, in the composition for a functional layer, conventionally known dispersants, surfactants, and antistatic agents can be used according to the purpose such as increasing the hardness of the functional layer, suppressing curing shrinkage, or controlling the refractive index. Silane coupling agents, thickeners, anti-coloring agents, coloring agents (pigments, dyes), antifoaming agents, leveling agents, flame retardants, UV absorbers, adhesion promoters, polymerization inhibitors, antioxidants, surface modification A texture agent, a lubricant and the like may be added.

  It is also preferable to appropriately add a known polysiloxane type or fluorine type antifouling agent to the low refractive index layer in order to improve fingerprint resistance. Preferred examples of the polysiloxane based antifouling agent include polyether modified polydimethylsiloxane having an acrylic group, polyether modified dimethylsiloxane, polyester modified dimethylsiloxane having an acrylic group, polyether modified polydimethylsiloxane, polyester modified polydimethyl. Siloxane, aralkyl modified polymethyl alkyl siloxane etc. are mentioned. The fluorine-based antifouling agent preferably has a substituent that contributes to the formation of the low refractive index layer or the compatibility with the low refractive index layer. The substituent may be one or more, and the plurality of substituents may be the same or different. Examples of preferable substituents include acryloyl group, methacryloyl group, vinyl group, aryl group, cinnamoyl group, epoxy group, oxetanyl group, hydroxyl group, polyoxyalkylene group, carboxyl group, amino group and the like.

The surface of the low refractive index layer may be an uneven surface (for example, an antiglare surface), but is preferably a smooth surface.
When the surface of the low refractive index layer is a smooth surface, the arithmetic average roughness Ra (JIS B 0601: 1994) of the surface of the low refractive index layer is preferably 20 nm or less, more preferably 15 nm or less, and further preferably Is 10 nm or less, particularly preferably 1 to 8 nm. The ten-point average roughness Rz (JIS B 0601: 1994) of the surface of the low refractive index layer is preferably 160 nm or less, more preferably 50 to 155 nm.

In order to make Ra of the low refractive index layer in the above range, for example, the following method can be adopted.
-Do not use particles with a particle diameter exceeding 1/2 of the thickness of the low refractive index layer in the low refractive index layer, the high refractive index layer, the hard coat layer or the like, or reduce the addition amount thereof.
-Reduce the surface roughness of the layers inside the low refractive index layer (high refractive index layer, base film layer, optically isotropic layer, hard coat layer, etc.).
-When the roughness of the substrate film and the optically isotropic layer is large, the surface is smoothed with a hard coat layer or the like.

(Hard coat layer)
The hard coat layer may be provided on the substrate film and / or the optically isotropic layer directly or through another film or layer. The hard coat layer may further have other functions and may be an optically isotropic layer.
The hard coat layer preferably has a pencil hardness of H or more, more preferably 2H or more. The hard coat layer can be provided, for example, by applying and curing a composition solution of a thermosetting resin or a radiation curable resin.

  As a thermosetting resin, an acrylic resin, a urethane resin, a phenol resin, a urea melamine resin, an epoxy resin, an unsaturated polyester resin, a silicone resin, a combination thereof, and the like can be mentioned. In the thermosetting resin composition, a curing agent is added to these curable resins as needed.

  The radiation curable resin is preferably a compound having a radiation curable functional group, and as the radiation curable functional group, an ethylenic unsaturated bond group such as (meth) acryloyl group, vinyl group, allyl group, epoxy group And oxetanyl groups. Among these, as the ionizing radiation-curable compound, a compound having an ethylenically unsaturated bond group is preferable, and a compound having two or more ethylenically unsaturated bond groups is more preferable, and in particular, two ethylenically unsaturated bond groups The polyfunctional (meth) acrylate compound having the above is more preferable. The polyfunctional (meth) acrylate compound may be a monomer, an oligomer or a polymer.

As specific examples of these, those mentioned as the binder resin of the low refractive index layer are used.
In order to achieve the hardness as a hard coat, the compound having a radiation curable functional group preferably contains 50% by mass or more of a bifunctional or higher monomer, and more preferably 70% by mass or more. Furthermore, in the compound having a radiation curable functional group, the content of the trifunctional or higher monomer is preferably 50% by mass or more, and more preferably 70% by mass or more.
The compound which has the said radiation curable functional group can be used 1 type or in combination of 2 or more types.

  The thickness of the hard coat layer is preferably in the range of 0.1 to 100 μm, and more preferably in the range of 0.8 to 20 μm.

The refractive index of the hard coat layer is more preferably 1.45 to 1.70, and still more preferably 1.50 to 1.60.
The refractive index of the hard coat layer is a value measured under the condition of wavelength 589 nm.

  In order to adjust the refractive index of the hard coat layer, there are mentioned a method of adjusting the refractive index of the resin, and a method of adjusting the refractive index of the particles when adding the particles. Examples of the particles include those exemplified as particles of the optically isotropic layer or the low refractive index layer.

(Antistatic layer)
It is also a preferable form to separately provide an antistatic layer. The antistatic layer is formed between the base film and the high refractive index layer, between the optically isotropic layer and the high refractive index layer, between the base film and the hard coat layer, and between the optically isotropic layer and the hard coat layer. In the meantime, it is preferable to provide in the surface etc. by which the high refractive index layer of a base film or optically isotropic layer is not laminated | stacked. The antistatic layer preferably comprises an antistatic agent and a binder resin.

  Examples of antistatic agents include quaternary ammonium salts, conductive polymers such as polyaniline and polythiophene, needle-like metal fillers, conductive high refractive index fine particles such as tin-doped indium oxide fine particles, and antimony-doped tin oxide fine particles, and combinations thereof Be

  As the binder resin, polyester, polyurethane, polyamide, acrylic or the like is used.

  An antistatic agent may be added to the hard coat layer, and the hard coat layer may function as the antistatic layer. As the antistatic agent to be added to the hard coat layer, conventionally known ones can be used. For example, cationic antistatic agents such as quaternary ammonium salt, fine particles such as tin-doped indium oxide (ITO), conductive polymer Etc. can be used. It is preferable that content of the said antistatic agent is 1-30 mass% with respect to the total mass of the total solid of a hard-coat layer.

  The laminated film of the present invention may be provided with various functional layers on the surface according to each application. The various functional layers include a hard coat layer, an antiglare layer, an antireflective layer, a low reflection layer, a conductive layer, an antistatic layer, a colored layer, an ultraviolet absorbing layer, an antifouling layer, an adhesive layer and the like.

(Use of laminated film)
The laminated film of the present invention is not only an optical polarizer film such as a polarizer protective film or a depolarizing film, a transparent conductive substrate film such as a touch panel, an anti-scattering film, a surface design-imparting film, etc. It can be used in various fields such as films and films for decoration.

  In one embodiment, it is preferable to use a transparent conductive laminated film for a touch panel. Among them, it is preferable to use for a capacitive touch panel.

  When using as a touch panel, two films provided with a transparent conductive layer only on one side may be combined to form a touch sensor, or the transparent conductive film of the present invention and a film such as TAC or COP, or a general PET. The touch sensor may be configured in combination with a transparent conductive film as a substrate. Furthermore, a combination of the transparent conductive film of the present invention and a transparent conductive layer provided on another component such as a surface cover glass may be used as a touch sensor. In addition, transparent conductive layers may be provided on both sides of the laminated film to form a touch sensor.

  When pasting the transparent conductive film of the present invention as a constitution of a touch sensor, a pressure-sensitive adhesive without substrate for optics, an ultraviolet-ray or thermosetting adhesive, etc., and a conventionally used adhesive or adhesive are used without limitation. be able to.

  The transparent conductive film can be used to prevent rainbow marks and coloring which occur when viewing a liquid crystal display device or an organic EL display device provided with a circularly polarizing plate with polarizing sunglasses. In this case, the angle between the transmission axis direction of the polarizer of the most visible side polarizing plate of the display device and the slow axis or fast axis of the base film of the laminated film is preferably 20 to 45 degrees. The angle is more preferably 25 to 45 degrees, still more preferably 30 to 45 degrees, and particularly preferably 35 to 45 degrees. If the above range is exceeded, the change in brightness (depending on the viewing angle) may be large when the display is viewed with the head tilted.

The transparent conductive film of the present invention and the transparent conductive film of the present invention are used in combination with a biaxially stretched PET film (retardation of 500 nm or more and less than 3000) generally used as a substrate for shatterproof films and transparent conductive films and the transparent conductive film of the present invention. The arrangement order of general biaxially oriented PET films is arbitrary.
When the transmission axis of the viewing side polarizer of the image display device is approximately 45 degrees to the short side of the image display device and the transparent conductive film is placed on the viewing side of the transparent resin molded product, the base of the laminated film The angle between the slow axis or fast axis of the material film and the transmission axis of the polarizer is preferably 20 degrees or less, more preferably 15 degrees or less, and still more preferably 10 degrees or less.

  When a general biaxially stretched PET film is used in a plurality, it is preferable that the transparent conductive film of the present invention is provided on the most visible side or the most light source side. Such arrangement can effectively prevent rainbow marks and coloring.

  In the case of a liquid crystal display device or an organic EL display device of a VA system or an IPS system, the transmission axis of the viewing side polarizer is generally parallel or perpendicular to the vertical direction (short side direction) of the screen. When a transparent conductive film is disposed in such a display device, the slow axis of the substrate film is preferably disposed at about 45 degrees (45 degrees ± 10 degrees or less) with the transmission axis of the polarizer.

In the case of a liquid crystal display device of the TN type, generally, the transmission axis of the viewing side polarizer is approximately 45 degrees in the vertical direction (short side direction) of the screen. When the transparent conductive film is disposed on the most light source side, the slow axis of the base film is preferably disposed at about 45 degrees (45 degrees ± 10 degrees or less) with the transmission axis of the polarizer. On the other hand, when the transparent conductive film is disposed on the most visible side, the slow axis of the base film is substantially parallel (0 ° ± 10 ° or less) or nearly perpendicular (90 ° ± 10 ° or less) to the transmission axis of the polarizer Is preferred.
In the above, the most light source side and the most visible side are generally biaxially stretched PET films provided as a scattering prevention film and a transparent conductive film on the viewing side from the polarizing plate of a liquid crystal display device or an EL display device Among the transparent conductive films of the present invention having a retardation of 500 nm or more and less than 3000, the light source side means the most visible side.

  The touch panel using the transparent conductive film of the present invention is provided on the front surface of the display device. The display device is not particularly limited, such as a liquid crystal display device or an organic electroluminescent display device. In the case of a liquid crystal display device, various light sources can be used without iridescence, and among them, light sources of blue light emitting diode and yellow phosphor, light sources using KSF phosphor, QD light source and the like are preferable.

(Display device)

  Backlights of liquid crystal display devices include blue light emitting diode and yellow fluorescent light source, blue-green red light emitting diode light source, blue light emitting diode, green fluorescent light and red fluorescent light source, wavelength conversion light source by quantum dots, semiconductor A laser light source, a cold cathode tube, etc. can be used without particular limitation.

  The display device including the transparent conductive film according to the present invention is reduced to a level at which iridescence can not be recognized even when having a light source having a sharp emission peak, and a light source having a narrow half width of emission peak of each color. The combination with is a more preferable form. The half width of the light emission peak having the narrowest half width is preferably 25 nm or less, more preferably 20 nm or less, still more preferably 15 nm or less, particularly preferably 10 nm or less. The lower limit of the half bandwidth is 0.5 nm in terms of realistic values or resolution of the measuring instrument. Specifically, a QD (quantum dot) light source and a light source using a KSF phosphor for the red region are mentioned as preferable light sources, and the most preferable light source is one using a KSF phosphor.

Hereinafter, the present invention will be more specifically described with reference to examples. The present invention is not limited to the following examples, and can be implemented with appropriate modifications as long as they are compatible with the spirit of the present invention. These are all included in the technical scope of the present invention.
The evaluation method of the physical property in an Example is as follows.

(1) Slow axial refractive index (Bfnx), fast axial refractive index (Bfny), and refractive index anisotropy (ΔBfNxy) of base film
The orientation axis direction of the substrate film before roughening is determined using a molecular orientation meter (MOA-6004 type molecular orientation meter, manufactured by Oji Scientific Instruments Co., Ltd.), and 4 cm so that the orientation axis direction becomes a long side. A rectangle of 2 cm in size was cut out and used as a measurement sample. About this sample, the refractive index (Bfnx, Bfny) of the orthogonal biaxial and the refractive index (Bfnz) in the thickness direction are measured using an Abbe refractometer (manufactured by Atago Co., NAR-4T, measurement wavelength 589 nm). The absolute value (| Bfny-Bfnx |) of the difference between the two refractive indexes is taken as the refractive index anisotropy (ΔBfNxy). In addition, the refractive index of the roughened base film can be measured by polishing with a water-resistant paper or the like to flatten the roughened surface.

(2) Thickness d of original film
The thickness at five points was measured using an electric micrometer (Filt Luff, Millitron 1245D), and the average value was determined.

(3) In-plane retardation (Re)
The in-plane retardation (Re) was determined from the product (ΔBfNxy × d) of the anisotropy of the refractive index (ΔBfNxy) and the thickness d (nm) of the film.

(4) Nz coefficient The value obtained by | Bfnx-Bfnz | / | Bfnx-Bfny |

(5) Degree of plane orientation (ΔP)
The value obtained by (Bfnx + Bfny) / 2-Bfnz was taken as the degree of plane orientation (ΔP).

(6) Thickness direction retardation (Rth)
The thickness direction retardation is obtained by multiplying the film thickness d by two birefringence ΔBfNxz (= | Bfnx-Bfnz |) and ΔBfNyz (= | Bfny-Bfnz |) as viewed from the cross section in the film thickness direction. It is a parameter which shows the average of the retardation obtained. Find Bfnx, Bfny, Bfnz and film thickness d (nm) by the same method as above, calculate the average value of (ΔBfNxz × d) and (ΔBfNyz × d), and calculate the thickness direction retardation (Rth) Obtained: Rth = (ΔBfNxz × d + ΔBfNyz × d) / 2.

(7) Surface roughness (Ra, Rq, Rz, Ry, Rp, Rv, Sm)
Each parameter of surface roughness was measured from a roughness curve measured using a contact roughness meter (Mitutoyo SJ-410, detector: 178-396-2, stylus: standard stylus 122 AC 731 (2 μm)). I asked. The setting was as follows.
Curve: R
Filter: GAUSS
λc: 0.8 mm
λs: 2.5 μm
Measurement length: 5 mm
Measurement speed: 0.5 mm / s
In addition, Rq was calculated | required based on JISB0601-2001 and others based on JISB0601-1994.

(8) Thickness of Optically Isotropic Layer The thickness of the roughened base film and laminated film is as follows: embedded each film in an epoxy resin, cut out a section of the cross section, and observe with a microscope to obtain 10 points at equal intervals. The thickness was measured and taken as the average value. In addition, when the interface was hard to see, a polarization microscope was used. Moreover, the uneven surface of the roughened base film was based on the center of the convex portion and the concave portion in the field of view. The thickness of the optically isotropic layer was determined by subtracting the thickness of the roughened base film from the thickness of the laminated film.

(9) Refractive index of optically isotropic layer Under the same conditions as in the case of providing the optically anisotropic layer on the uneven surface of the mold release film, the thickness is about 20 μm, and the refractive index of the sample peeled from the mold release film It measured by carrying out similarly to the base film. It was confirmed that nx, ny and nz had the same value.

(Production of easy adhesion layer components)
(Polymerization of polyester resin)
In a stainless steel autoclave equipped with a stirrer, a thermometer, and a partial reflux condenser, 194.2 parts by mass of dimethyl terephthalate, 184.5 parts by mass of dimethyl isophthalate, 14.8 parts by mass of dimethyl-5-sodium sulfoisophthalate Then, 233.5 parts by mass of diethylene glycol, 136.6 parts by mass of ethylene glycol and 0.2 parts by mass of tetra-n-butyl titanate were charged, and transesterification was performed at a temperature of 160 ° C. to 220 ° C. for 4 hours. Then, the temperature was raised to 255 ° C., and the reaction system was gradually depressurized, and then reacted under a reduced pressure of 30 Pa for 1 hour and 30 minutes to obtain a copolyester resin. The resulting copolyester resin was pale yellow and transparent. The reduced viscosity of the copolyester resin was measured and found to be 0.70 dl / g. The glass transition temperature by DSC was 40.degree.

(Preparation of polyester water dispersion)
In a reactor equipped with a stirrer, a thermometer and a reflux apparatus, 30 parts by mass of the copolymerized polyester resin and 15 parts by mass of ethylene glycol n-butyl ether were added, and the mixture was heated and stirred at 110 ° C. to dissolve the resin. After the resin was completely dissolved, 55 parts by weight of water was gradually added to the polyester solution while stirring. After the addition, the solution was cooled to room temperature while being stirred to prepare a milky white polyester water dispersion having a solid content of 30% by mass.

(Polymerization of block polyisocyanate type crosslinking agent used in easy adhesion layer)
100 parts by mass of polyisocyanate compound having isocyanurate structure (Duranate TPA, manufactured by Asahi Kasei Chemicals Corp.) having hexamethylene diisocyanate as a raw material in a flask equipped with a stirrer, thermometer, and reflux condenser, 55 parts by mass of propylene glycol monomethyl ether acetate And 30 parts by mass of polyethylene glycol monomethyl ether (average molecular weight 750) were charged, and maintained at 70 ° C. for 4 hours under a nitrogen atmosphere. Thereafter, the reaction solution temperature was lowered to 50 ° C., and 47 parts by mass of methyl ethyl ketoxime was dropped. The infrared spectrum of the reaction solution was measured to confirm that the absorption of the isocyanate group disappeared, and a block polyisocyanate water dispersion having a solid content of 75% by mass was obtained.

(Preparation of coating solution for easy adhesion layer)
The following coating agents were mixed to prepare a P1 coating solution.
Water 50.00 mass%
Isopropanol 33.00 mass%
Polyester water dispersion 12.00 mass%
Blocked isocyanate type crosslinking agent 0.80 mass%
Particles 1.40% by mass
(Silica sol with an average particle size of 100 nm, solid concentration 40% by mass)
Catalyst (Organotin-based compound solid concentration 14% by mass) 0.30% by mass
0.50 mass% of surfactant
(Silicone, solid content 10% by mass)

(Production of polyester resin for film)
(Production Example 1-Polyester X)
The temperature of the esterification reactor was raised, and when it reached 200 ° C., 86.4 parts by mass of terephthalic acid and 64.6 parts by mass of ethylene glycol were charged, and 0.017 parts by mass of antimony trioxide as a catalyst while stirring Then, 0.064 parts by mass of magnesium acetate tetrahydrate and 0.16 parts by mass of triethylamine were charged. Then, the temperature was raised under pressure, and a pressure esterification reaction was carried out under conditions of a gauge pressure of 0.34 MPa and 240 ° C. Then, the esterification reaction vessel was returned to normal pressure, and 0.014 parts by mass of phosphoric acid was added . Furthermore, the temperature was raised to 260 ° C. over 15 minutes, and 0.012 parts by mass of trimethyl phosphate was added. Then, after 15 minutes, dispersion treatment was carried out with a high pressure disperser, and after 15 minutes, the obtained esterification reaction product was transferred to a polycondensation reaction can, and a polycondensation reaction was performed at 280 ° C. under reduced pressure.

  After completion of the polycondensation reaction, filtration treatment is carried out with a Naslon (registered trademark) filter with a 95% cut diameter of 5 μm, extruded in a strand form from a nozzle, and cooling water subjected to filtration treatment (pore diameter: 1 μm or less) It was cooled, solidified, and cut into pellets. The intrinsic viscosity of the obtained polyethylene terephthalate resin (X) was 0.62 dl / g, and substantially no inert particles and internally precipitated particles were contained. (Hereafter, it is abbreviated as PET (X).)

(Production of original film A, B)
The PET (X) resin pellet containing no particles is supplied to an extruder as a raw material for a film, sheeted and extruded from a die, and then wound around a casting drum having a surface temperature of 30 ° C. using an electrostatic application casting method. It solidified by cooling and produced the unstretched film. Next, the P1 coating solution is applied to both sides of this unstretched PET film so that the coating amount after drying is 0.12 g / m ² by reverse roll method, and then it is directed to a dryer and dried at 80 ° C. for 20 seconds did.

The unstretched film on which this coated layer was formed was guided to a tenter stretching machine, and while holding the end of the film with a clip, it was guided to a hot air zone at a temperature of 135 ° C. and stretched 3.8 times in the width direction. Next, while maintaining the width stretched in the width direction, the film is treated at a temperature of 225 ° C. for 30 seconds, and then both ends of the film cooled to 130 ° C. are cut with a shear blade and a tension of 0.5 kg / mm ² The ear portion was cut off with the above, and wound up to obtain an original film A having a film thickness of 80 μm.

  A film was produced in the same manner as in the raw film A except that the line speed after casting was increased to change the thickness of the unstretched film, and a raw film B having a different film thickness was obtained.

(Production of original film C)
An unstretched film (coated with an easily adhesive layer) prepared by the same method as the raw film A is heated to 105 ° C. using a heated roll group and an infrared heater, and then a roll group having a peripheral speed difference The film was drawn by 2.0 times in the running direction, and then introduced into a hot air zone at a temperature of 135 ° C. by a method similar to that for the raw film A, and then stretched by 4.0 times in the width direction to obtain a raw film C.

(Raw film D)
An unstretched film (coated with an easily adhesive layer) prepared by the same method as the raw film A is heated to 105 ° C. using a heated roll group and an infrared heater, and then a roll group having a peripheral speed difference After stretching 3.5 times in the running direction, the film was introduced into a hot air zone at a temperature of 135 ° C. in the same manner as in the raw film A and stretched 3.5 times in the width direction to obtain a raw film D.

(Production of surface roughened film)
Affix polyurethane foam to a glass plate and affix the periphery of the original film A with a double-sided tape on top of that, and use this hand-held belt sander (sanding belt # 320) to hold the original film surface vertically, horizontally or diagonally The surface roughened film A1 was obtained by processing from a total of 4 directions of 45 degrees and 135 degrees.
The periphery of the raw film A was attached to a glass plate with a double-sided tape, set in a dry sand blaster, and treated by blowing an abrasive (sand blast treatment) to obtain a surface roughened film A2.
A masking film made of polypropylene film is laminated on one side of the raw film A, dipped in a 38% aqueous potassium hydroxide solution (95 ° C.) (chemical etching), washed with water, peeled off and dried. The surface roughened film A4 was obtained.
The surface roughened films shown in Table 2 are obtained from the raw films A, B, C, and D by changing the conditions of the belt sander (type of the sanding belt, etc.) and the conditions of the sand blast (particle diameter of the abrasive). The
The # 320 sanding belt was used for the production of B1 and C1, and the # 180 sanding belt was used for the production of A3 and D1. Moreover, the abrasives of the sand blaster used a large thing in order of A5, A6, B2, and A2.
In the belt sander treatment and sand blast treatment, the treated surface was lightly polished with # 400 sandpaper to remove the influence of local protrusions.

(Production of laminated films F1 to F17)
(Preparation of coating agent for optically isotropic layer)
What was shown in Table 3 as a coating agent for optical isotropic layers was prepared.

  A surface of the surface roughening film A1 of 20 cm × 30 cm is coated with a four-fold diluted solution of the above-mentioned easy adhesion layer with a solution of water / isopropanol = 2/1 and dried, and the adhesion is about 30 nm A layer was provided. Furthermore, after coating agent a for optical isotropic layers with an applicator with an applicator, it was made to harden | cure from a coated surface with a high pressure mercury lamp, and laminated film F1 was obtained.

  Laminated films F2 to F8 and F10 to F17 were obtained in the same manner as in Example 1 except that the type of the surface roughened film and / or the coating agent was changed. In addition, the laminated film F15 provided the optically isotropic layer on both surfaces.

  A surface of the surface roughening film A1 of 20 cm × 30 cm is coated with a four-fold diluted solution of the above-mentioned easy adhesion layer with a solution of water / isopropanol = 2/1 and dried, and the adhesion is about 30 nm A layer was provided. Furthermore, a coating agent a for an optical isotropic layer is coated thereon with an applicator, and then a surface nickel-plated metal plate mold provided with a concavo-convex structure to overlap the coated surface to give anti-glare properties is overlaid. From the surface, it was cured with a high pressure mercury lamp to obtain a laminated film F9 having an antiglare property to the optically isotropic layer.

  The configuration and physical properties of the laminated films F1 to F17 are shown in Table 4.

Examples 1 to 13 and Comparative Examples 1 to 3 Preparation of a Transparent Conductive Film Having a Transparent Conductive Layer on the Optically Isotropic Layer Surface A long film of biaxially stretched polyester film (A4300) manufactured by Toyobo Co., Ltd. One of them was attached at intervals of about 20 m so that the optically isotropic layer surface was facing up, and was wound to make a film roll. This film roll is introduced into a take-up type sputtering apparatus, and a 20 nm-thick indium tin oxide layer (argon gas 98% and oxygen 2% 0.4 Pa) is formed on the surface (optically isotropic layer surface) as a transparent conductive layer. In the atmosphere, sputtering was performed using a sintered body consisting of 97% by weight of indium oxide and 3% by weight of tin oxide, and then annealing treatment was performed to crystallize the ITO layer to prepare a transparent conductive film.

Examples 14 to 26, Comparative Examples 4 to 6
Peltron (TM) A-2005 (manufactured by Pelnox Co., Ltd.) was applied to the base film surface of the laminated films F1 to F17, and ultraviolet rays were irradiated to form a hard coat layer having a thickness of 5 μm. The obtained laminated film is attached to a biaxially stretched polyester film (A4300) manufactured by Toyobo Co., Ltd. so that the base film surface (hard coated surface) is a surface, and the surface (hard coated surface) as in Example 1 ) Was provided with a transparent conductive layer to produce a transparent conductive film.

Example 25
A high refractive index layer A (opstar KZ 6728 (manufactured by Arakawa Chemical Co., Ltd.) refractive index 1.74) was provided on the optically isotropic layer surface of the laminated film F4 so as to have a thickness of 1.5 μm. Then, in the same manner as in Example 1, a transparent conductive layer was provided on the surface (high refractive index layer A) to prepare a transparent conductive film.

Example 26
A hard coat layer was provided on the base film surface of the laminated film F5 in the same manner as in Example 14, and a high refractive index layer A was provided on the hard coat layer surface to a thickness of 1.5 μm. Then, in the same manner as in Example 1, a transparent conductive layer was provided on the surface (high refractive index layer A) to prepare a transparent conductive film.

Example 27
A low refractive index layer C (opstar TU-2362 (manufactured by Arakawa Chemical Co., Ltd.) refractive index 1.40) was provided on the optically isotropic layer surface of the laminated film F7 so as to have a thickness of 10 nm. Then, as in Example 1, a transparent conductive layer was provided on the surface (low refractive index layer C) to prepare a transparent conductive film.

Example 28
A transparent conductive film was produced in the same manner as in Example 25 except that the low refractive index layer C was provided on the high refractive index layer A so as to have a thickness of 10 nm.

Example 29
A transparent conductive film was produced in the same manner as in Example 26 except that the low refractive index layer C was provided on the high refractive index layer A so as to have a thickness of 10 nm.

Example 30
A high refractive index layer B (opstar Z7415 (manufactured by Arakawa Chemical Co., Ltd.) refractive index 1.65) is provided on the base film surface of the laminated film F5 so as to have a thickness of 150 nm, and a low refractive index layer C further having a thickness of 30 nm It was set up to be Then, as in Example 1, a transparent conductive layer was provided on the surface (low refractive index layer C) to prepare a transparent conductive film.

Example 31
A hard coat layer was provided on the base film surface of the laminated film F5 as in Example 14, and a high refractive index layer B was provided on the hard coat layer surface to a thickness of 150 nm. Using a silicon target doped with boron on the high refractive index layer B by sputtering, film formation is carried out in a mixed atmosphere consisting of 80% by volume of argon gas and 20% by volume of nitrogen gas A refractive index layer (refractive index 1.90, thickness 10 nm) is provided, and subsequently, in a mixed atmosphere consisting of 95% by volume of argon gas and 5% by volume of oxygen gas using a silicon target doped with boron by sputtering method A low refractive index layer made of silicon oxide (refractive index (n3) is 1.46, thickness 30 nm) was provided. Furthermore, a transparent conductive layer was provided on this low refractive index layer in the same manner as in Example 1 to prepare a transparent conductive film.

(Evaluation of transparent conductive film)
(Observation of rainbow blotches)
The transparent conductive layer is on the viewing side so that the slow axis of the base film is 45 degrees to the transmission axis of the polarizing plate on the light source side between two polarizing plates in which the transparent conductive film is disposed in cross nicol The state of transmitted light was observed from the front approximately 60 cm away from the polarizing plate on the viewing side, and the presence or absence of rainbow marks was evaluated according to the following criteria. In addition, the light source used the cold cathode tube.
○: Rainbow spots were not observed Δ: Slight rainbow spots were observed ×: Rainbow spots were observed

(Whitening)
The transparent conductive film was irradiated with a halogen lamp from below, and the whitening degree of the transparent conductive film was evaluated from the direction of 45 degrees obliquely upward according to the following criteria. The transparent conductive film had the transparent conductive layer on top.
◎: Almost no whitening was observed.
○: A slight whitening was observed, but the transparency was high.
Δ: Whitening was observed, and the transparency was somewhat inferior.
X: Whitening occurred and transparency was low.

(Bone visible)
The transparent conductive layer of the transparent conductive film was patterned into stripes of 1 mm in conductive layer and 1 mm in space by etching. The obtained patterned transparent conductive film was placed on a black paper and irradiated with a halogen lamp from above to evaluate whether the pattern could be confirmed.
◎: The pattern was not seen.
○: The pattern was slightly visible △: The pattern was clearly visible

  The structure, physical properties, and evaluation results of the transparent conductive film are shown in Table 5.

１＊：積層フィルム番号
２＊：粗面化フィルム番号
３＊：凹凸面
４＊：光学等方性層コート剤
５＊：光学等方層屈折率
６＊：透明導電層を設けた表面
７＊：ハードコート層の有無
８＊：虹斑評価
９＊：白化評価
１０＊：高屈折率層の有無
１１＊：低屈折率層の有無
１２＊：骨見え

1 *: laminated film number 2 *: roughened film number 3 *: uneven surface 4 *: optical isotropic layer coating agent 5 *: optical isotropic layer refractive index 6 *: surface 7 * provided with a transparent conductive layer : Hard coat layer present 8 *: rainbow blotch evaluation 9 *: whitening evaluation 10 *: high refractive index layer present 11 *: low refractive index layer present 12 *: bone visible

  With the transparent conductive film of the present invention, when used under an environment of a light source having a sharp peak etc., rainbow spots can be suppressed, and high transparency and vivid image display performance can be secured.

Claims (3)

A transparent conductive film having a transparent conductive layer on at least one surface of a laminate film having a base film and an optically isotropic layer, having the following features (a) to (c).
(A) At least one surface of the base film is an uneven surface, and the arithmetic average roughness (Ra) of the uneven surface is 0.2 to 10 μm.
(B) The refractive index anisotropy (Bfnx-Bfny) of a base film is 0.04-0.2.
(C) The optically isotropic layer is provided on the uneven surface of the base film, and the refractive index of the optically isotropic layer is Bfny-0.15 to Bfnx + 0.15.
(However, let the refractive index in the slow axis direction of the base film be Bfnx and the refractive index in the fast axis direction be Bfny) A touch panel comprising the transparent conductive film according to claim 1. An image display apparatus comprising the touch panel according to claim 2.