JP2019124918A - Laminated film and polarizing plate using the same - Google Patents

Abstract

To provide a polarizing plate 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 polarizing plate is provided, which comprises: a laminated film having features (a)-(c) below and comprising a base material film and an optically isotropic layer; a polarizer; and a retardation layer formed of a liquid crystal compound, laminated in the described order. (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 a polarizing plate with a retardation layer 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 to provide.

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 laminated film which has a base film and an optical isotropic layer which has the characteristics of following (a)-(c), the polarizing plate which has a retardation layer which consists of a polarizer and a liquid crystal compound in this order.
(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.
Item 2. A liquid crystal display device comprising the polarizing plate according to item 1.
Item 3.
An organic EL display device including the polarizing plate according to Item 1.

  By using the polarizing plate 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. In one embodiment, the polarizing plate with a retardation layer of the present invention is suitable for thinning, and it is used as a polarizing plate integrated with an optical compensation function of a liquid crystal display, and a circle for preventing reflection of organic EL display etc. It can be suitably used as a polarizing plate.

The polarizing plate has a laminated film having a substrate film of refractive index anisotropy having an irregular surface (rough surface) and an optically isotropic layer, a polarizer, and a retardation layer comprising a liquid crystal compound in this order. Is preferred. Hereinafter, simply referred to as “laminated film” means a laminated film of a substrate film of refractive index anisotropy having an uneven surface (roughened surface) and an optically isotropic layer. Moreover, what the polarizer was laminated | stacked on laminated | multilayer film may be called a "polarizer laminated film."
(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 a pressure-sensitive adhesive or a pressure-sensitive adhesive layer is used, a target is coated with a coating agent for pressure-sensitive adhesive and crosslinked or dried, or a substrate-less pressure-sensitive adhesive sheet is transferred. I mean one.

  The laminated film 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.

(Polarizer)
The type of polarizer used for the polarizing plate is not particularly limited. For example, a polarizer in which iodine or an organic dichroic dye is adsorbed to uniaxially stretched polyvinyl alcohol (PVA), a polarizer in which a liquid crystal compound and an organic dichroic dye are aligned, liquid crystalline dichroism Examples thereof include liquid crystal polarizers made of dyes, and wire grid type polarizers.

  In the case of a film-like polarizer in which iodine or an organic dichroic dye is adsorbed to uniaxially stretched polyvinyl alcohol (PVA), a laminated film can be laminated on at least one side of the polarizer to form a polarizing plate . The lamination can be performed using a PVA-based adhesive, an ultraviolet-curable adhesive, or a pressure-sensitive adhesive. In addition, the uneven surface of the film of refractive index anisotropy provided with the unevenness and the polarizer may be bonded with an adhesive or a pressure-sensitive adhesive having the characteristics corresponding to the optically isotropic layer. In this case, the film of the refractive index anisotropy and the adhesive or adhesive form a laminate film having the substrate film of refractive index anisotropy and the optically isotropic layer having the uneven surface in the present invention. The thickness of this type of polarizer is, for example, 5 to 50 μm, preferably 10 to 30 μm, and more preferably 12 to 25 μm. The thickness of the adhesive or pressure-sensitive adhesive is, for example, 1 to 10 μm, preferably 2 to 5 μm.

  In one embodiment, a polarizer in which PVA is applied to an unstretched or uniaxially stretched substrate and uniaxially stretched with the substrate to adsorb iodine or an organic dichroic dye (substrate laminated stretched polarizer) Is preferred. In this case, the polarizer laminated on the substrate and the laminated film are attached to each other with an adhesive or a pressure-sensitive adhesive, and then the substrate film used when forming the polarizer is peeled off, whereby a polarizing plate can be obtained. . In addition, the uneven surface of the film of refractive index anisotropy provided with the unevenness and the polarizer may be bonded with an adhesive or a pressure-sensitive adhesive having the characteristics corresponding to the optically isotropic layer. The thickness of the polarizer is, for example, 1 to 10 μm, preferably 2 to 8 μm, and more preferably 3 to 6 μm. The thickness of the adhesive or pressure-sensitive adhesive is, for example, 1 to 10 μm, preferably 2 to 5 μm.

  Thus, even a very thin polarizer is easy to handle due to the presence of a releasable support substrate, and a thin polarizer can be easily laminated to a polyester substrate film. By using such a thin polarizer, it is possible to further reduce the thickness. Many such polarizers are introduced, for example, in JP-A-2001-300521 and JP-A-2009-93074.

  The above-mentioned polarizer can be obtained, for example, by the following procedure. An unstretched or uniaxially stretched thermoplastic resin releasable support substrate uniaxially stretched in a direction perpendicular to the longitudinal direction is coated with PVA, and then the PVA is coated and the releasable support substrate of the thermoplastic resin and the PVA are laminated The body is stretched 2 to 20 times, preferably 3 to 15 times in the longitudinal direction. The stretching temperature is preferably 80 to 180 ° C, more preferably 100 to 160 ° C. Subsequently, the stretched laminate is immersed in a bath containing a dichroic dye to adsorb the dichroic dye. As a dichroic dye, iodine, an organic dye, etc. are mentioned, for example. When iodine is used, an aqueous solution of iodine and potassium iodide is preferred. Then, it is treated by being immersed in an aqueous solution of boric acid, washed with water and dried. In addition, you may perform 1.5 to 3 times extending | stretching as pre-stretching before adsorption | suction of a dichroic dye. This procedure is an example, and adsorption of the dichroic dye may be performed before stretching, or treatment with boric acid may be performed before adsorption of the dichroic dye. It may be stretched in a bath containing a dichroic dye or in a bath of an aqueous boric acid solution. Also, these steps may be divided into multiple stages and combined.

  As the releasable supporting substrate of the thermoplastic resin, polyester such as polyethylene terephthalate, polyolefin such as polypropylene and polyethylene, polyamide, polyurethane and the like are used. The releasability of the thermoplastic resin can be adjusted by carrying out corona treatment, providing a releasable coat, an easy adhesion coat or the like on the releasable supporting substrate of the thermoplastic resin.

A liquid crystalline polarizer is formed by applying a coating liquid containing a liquid crystal compound and an organic dichroic dye or a liquid crystalline dichroic dye to a laminated film and drying it, and then curing the film by light or heat. Then, polarizers can be stacked to form a polarizing plate. Examples of a method of orienting a liquid crystalline polarizer include a method of rubbing the surface of a laminated film, and a method of irradiating while applying polarized ultraviolet light and orienting and curing a liquid crystalline polarizer. In addition, since there is a certain degree of orientation control power on the substrate surface of the laminated film, orientation may be possible even by coating alone. In addition, it is also a preferable method to provide an orientation layer on the laminated film before providing a liquid crystalline polarizer. The following can be mentioned as a method of providing an orientation layer.
-A method of applying polyvinyl alcohol and its derivative, polyimide and its derivative, acrylic resin, polysiloxane derivative and the like and rubbing the surface thereof to form an alignment layer (rubbing alignment layer).
· A coating solution containing a polymer or monomer having a photoreactive group such as cinnamoyl group and chalcone group and a solvent is applied to a substrate film, and the film is oriented and cured by irradiating polarized ultraviolet light to form an alignment layer (photoalignment layer) And how to.
In addition, a base layer film of refractive index anisotropy having a concavo-convex surface is provided by providing a rubbing alignment layer having a characteristic corresponding to an optical isotropic layer on the concavo-convex surface of a refractive index anisotropic film having concavities and convexities. You may comprise a laminated film with the rubbing alignment layer which has property.

  Next, a coated polarizer in which a dichroic dye is blended with a liquid crystal compound will be described in detail. In the invention, the polarizing film may be provided directly on the laminated film as a substrate, but an orientation layer may be provided on the laminated film and the polarizing film may be provided thereon. In the present invention, the alignment film and the polarizing film may be collectively referred to as a polarizer, and when the polarizing film is provided without providing the alignment film on the laminated film, the polarizing film may be referred to as a polarizer. .

(Alignment layer)
The orientation layer can provide a polarization film having a higher degree of polarization by controlling the orientation direction of the polarization film. Any alignment layer may be used as the alignment layer as long as the liquid crystal compound of the polarizing film can be brought into a desired alignment state. Examples of the method for providing the alignment layer with an alignment state include rubbing on the surface, oblique deposition of an inorganic compound, and formation of a layer having microgrooves. Furthermore, it is also preferable to use a method of forming a photoalignment layer in which molecules are aligned by irradiation of polarized light to generate an alignment function. Two preferred examples of the rubbed alignment layer and the photoalignment layer are described below.

(Rubbed alignment layer)
As a polymer material used for the orientation layer formed by rubbing treatment, polyvinyl alcohol and its derivative, polyimide and its derivative, acrylic resin, polysiloxane derivative and the like are preferably used.

  First, a rubbing-treated alignment layer coating solution containing the above-mentioned polymer material is coated on a substrate film, and then dried by heating and the like to obtain an alignment layer before rubbing treatment. The coating solution for alignment layer may have a crosslinking agent.

  Any solvent that dissolves the polymer material can be used without limitation as a solvent for the rubbing treatment alignment layer coating solution. Specific examples thereof include alcohols such as water, methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol and cellosolve; ester solvents such as ethyl acetate, butyl acetate and gamma-butyrolactone; acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone And the like; aromatic hydrocarbon solvents such as toluene and xylene; and ether solvents such as tetrahydrofuran and dimethoxyethane. These solvents may be used alone or in combination.

  The concentration of the rubbing-treated alignment layer coating solution can be appropriately adjusted depending on the type of polymer and the thickness of the alignment layer to be produced, but is preferably 0.2 to 20% by mass in terms of solid content concentration. The range of 3 to 10% by mass is particularly preferable.

  Examples of the coating method include known methods such as a coating method such as a gravure coating method, a die coating method, a bar coating method and an applicator method, and a printing method such as a flexo method.

  The temperature of the heat drying depends on the base film, but in the case of PET, the range of 30 ° C. to 170 ° C. is preferable, more preferably 50 to 150 ° C., and still more preferably 70 to 130 ° C. When the drying temperature is low, it may be necessary to take a long drying time, which may result in poor productivity. If the drying temperature is too high, the orientation state of the substrate film is affected, the retardation may decrease, the heat shrinkage of the substrate film may increase, and the optical function as designed can not be achieved, and the flatness is bad. It may be said that The heating and drying time may be, for example, 0.5 to 30 minutes, more preferably 1 to 20 minutes, and still more preferably 2 to 10 minutes.

  The thickness of the rubbing alignment layer is preferably 0.01 to 10 μm, more preferably 0.05 to 5 μm, and particularly preferably 0.1 μm to 1 μm.

  The rubbing treatment can be carried out generally by rubbing the surface of the polymer layer with paper or cloth in a certain direction. In general, the surface of the alignment film is rubbed using a rubbing roller of a nonwoven fabric of nylon, polyester, acrylic or the like.

  Adjustment of the angle of the rubbing direction can be performed by adjusting the angle between the rubbing roller and the base film, and adjusting the transport speed of the base film and the number of rotations of the roller.

  In addition, it is also possible to carry out a rubbing process directly to a base film, and to make the base film surface have an orientation layer function, and also in this case is included in the technical scope of the present invention.

(Photo alignment layer)
Photo-alignment layer is an alignment film that is coated with a coating solution containing a polymer or monomer having a photo-reactive group and a solvent on a substrate film, and is irradiated with polarized light, preferably polarized ultraviolet light to give alignment control power. Say The photoreactive group refers to a group that generates liquid crystal alignment ability by light irradiation. Specifically, it generates a photoreaction that is the source of liquid crystal alignment ability, such as alignment induction or isomerization reaction of molecules generated by light irradiation, dimerization reaction, photocrosslinking reaction, or photolysis reaction. is there. Among the photoreactive groups, those which cause a dimerization reaction or a photocrosslinking reaction are preferable in that they are excellent in the orientation and maintain the smectic liquid crystal state of the polarizing film. The photoreactive group capable of causing the above reaction is preferably an unsaturated bond, particularly a double bond, and a group consisting of a C = C bond, a C = N bond, an N = N bond, a C 群 O bond Particularly preferred is a group having at least one selected from the group consisting of

  Examples of the photoreactive group having a C = C bond include a vinyl group, a polyene group, a stilbene group, a stilbazole group, a stilbazolium group, a chalcone group and a cinnamoyl group. Examples of photoreactive groups having a C = N bond include groups having structures such as aromatic Schiff bases and aromatic hydrazones. Examples of the photoreactive group having an N = N bond include an azobenzene group, an azonaphthalene group, an aromatic heterocyclic azo group, a bisazo group, a formazan group and the like, and a group having an azoxybenzene as a basic structure. As a photoreactive group having a C = O bond, a benzophenone group, a coumarin group, an anthraquinone group, a maleimide group and the like can be mentioned. These groups may have a substituent such as an alkyl group, an alkoxy group, an aryl group, an allyloxy group, a cyano group, an alkoxycarbonyl group, a hydroxyl group, a sulfonic acid group and a halogenated alkyl group.

  Among the above, a photoreactive group capable of causing a photodimerization reaction is preferable, and a cinnamoyl group and a chalcone group have a relatively small irradiation amount of polarized light necessary for photoalignment, and a photoalignment excellent in thermal stability and temporal stability It is preferable because a layer is easily obtained. As the polymer having a photoreactive group, those having a cinnamoyl group which has a cinnamic acid structure at the end of the polymer side chain are particularly preferable. Examples of the structure of the main chain include polyimide, polyamide, (meth) acrylic, polyester and the like.

  Specific alignment layers are described, for example, in JP-A-2006-285197, JP-A-2007-76839, JP-A-2007-138138, JP-A-2007-94071, JP-A-2007-121721, and the like. JP 2007-140465, JP 2007-156439, JP 2007-133184, JP 2009-109831, JP 2002-229039, JP 2002-265541, JP 2002 The alignment layer described in JP-A-317013, JP-A-2003-520878, JP-A-2004-529220, JP-A-2013-33248, JP-A-2015-7702, JP-A-2015-129210 is It can be mentioned.

  As a solvent of the coating liquid for forming a photoalignment layer, any polymer capable of dissolving a photoreactive group-containing polymer and a monomer can be used without limitation. As a specific example, those mentioned for the rubbing-treated alignment layer can be exemplified. It is also preferable to add a photopolymerization initiator, a polymerization inhibitor, and various stabilizers to the coating liquid for forming a photoalignment layer. In addition, a polymer having a photoreactive group and a polymer other than a monomer or a monomer having no photoreactive group copolymerizable with a monomer having a photoreactive group may be added.

  The concentration of the coating solution for forming a photoalignment layer, the coating method, and the drying conditions can also be exemplified by those described for the rubbing-treated alignment layer. The thickness is also the same as the preferred thickness of the rubbing alignment layer.

  By irradiating the light alignment layer before alignment obtained in this manner with polarized light, a light alignment layer can be obtained.

  Polarized light may be irradiated to the light alignment layer before alignment from the alignment layer surface. In addition, when making the orientation direction of a photo-alignment film parallel or perpendicular | vertical to the orientation direction of the base film of laminated | multilayer film, you may permeate | transmit laminated | multilayer film and it may irradiate.

  The wavelength of polarized light is preferably in the wavelength range in which the photoreactive group of the polymer or monomer having a photoreactive group can absorb light energy. Specifically, ultraviolet light having a wavelength of 250 to 400 nm is preferable.

  Examples of polarized light sources include xenon lamps, high pressure mercury lamps, ultra high pressure mercury lamps, metal halide lamps, ultraviolet light lasers such as KrF and ArF, and the like, and high pressure mercury lamps, ultra high pressure mercury lamps and metal halide lamps are preferred.

  Polarization is obtained, for example, by passing light from the light source through a polarizer. The direction of polarization can be adjusted by adjusting the polarization angle of the polarizer. Examples of the polarizer include polarizing filters, polarizing prisms such as Glan-Thomson and Glan-Teller, and wire grid type polarizers. The polarization is preferably substantially parallel light.

  By adjusting the angle of polarized light to be irradiated, the direction of the alignment control force of the light alignment layer can be arbitrarily adjusted.

The irradiation intensity varies depending on the type and amount of the polymerization initiator and the resin (monomer), but is preferably 10 to 10000 mJ / cm ² and more preferably ²⁰ to 5000 mJ / cm ^{2 based on} 365 nm.

(Polarizing film)
The polarizing film has a function as a polarizer that transmits polarized light in only one direction, and includes a dichroic dye.

(Dichroic dye)
The dichroic dye is a dye having a property in which the absorbance in the long axis direction of the molecule and the absorbance in the short axis direction are different.

  The dichroic dye is preferably one having an absorption maximum wavelength (λMAX) in the range of 300 to 700 nm. Such dichroic dyes include, for example, acridine dyes, oxazine dyes, cyanine dyes, naphthalene dyes, azo dyes and anthraquinone dyes, among which azo dyes are preferred. Examples of the azo dye include monoazo dyes, bisazo dyes, trisazo dyes, tetrakisazo dyes, stilbene azo dyes and the like, with preference given to bisazo dyes and trisazo dyes. The dichroic dyes may be used alone or in combination, but in order to adjust the color tone (achromatic color), it is preferable to combine two or more kinds. In particular, it is preferable to combine three or more types. In particular, it is preferable to combine three or more azo compounds.

  Examples of preferable azo compounds include the dyes described in JP-A-2007-126628, JP-A-2010-168570, JP-A-2013-101328, and JP-A-2013-210624.

  It is also a preferred form that the dichroic dye is a dichroic dye polymer introduced to the side chain of a polymer such as acrylic. Examples of these dichroic dye polymers include the polymers listed in JP-A-2016-4055, and polymers obtained by polymerizing the compounds of [Chemical 6] to [Chemical 12] of JP-A 2014-206682.

  The content of the dichroic dye in the polarizing film is preferably 0.1 to 30% by mass, more preferably 0.5 to 20% by mass, in the polarizing film, from the viewpoint of making the orientation of the dichroic dye excellent. 1.0 to 15% by mass is more preferable, and 2.0 to 10% by mass is particularly preferable.

  The polarizing film preferably further contains a polymerizable liquid crystal compound in order to improve the film strength, the degree of polarization, and the film uniformity. In addition, the thing after superposition | polymerization is also contained as a film | membrane as a polymeric liquid crystal compound here.

(Polymerizable liquid crystal compound)
The polymerizable liquid crystal compound is a compound having a polymerizable group and exhibiting liquid crystallinity. The polymerizable group means a group involved in the polymerization reaction, and is preferably a photopolymerizable group. The photopolymerizable group refers to a group capable of undergoing a polymerization reaction by an active radical or an acid generated from a photopolymerization initiator described later. Examples of the polymerizable group include vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyloxy group, methacryloyloxy group, oxiranyl group, oxetanyl group and the like. Among them, acryloyloxy group, methacryloyloxy group, vinyloxy group, oxiranyl group and oxetanyl group are preferable, and acryloyloxy group is more preferable. The compound exhibiting liquid crystallinity may be a thermotropic liquid crystal or a lyotropic liquid crystal, and may be a nematic liquid crystal or a smectic liquid crystal in the thermotropic liquid crystal.

  The polymerizable liquid crystal compound is preferably a smectic liquid crystal compound from the viewpoint that higher polarization properties can be obtained, and a higher order smectic liquid crystal compound is more preferable. When the liquid crystal phase formed by the polymerizable liquid crystal compound is a high-order smectic phase, a polarizing film having a higher degree of alignment order can be produced.

  Specific preferable polymerizable liquid crystal compounds are described, for example, in JP-A-2002-308832, JP-A-2007-16207, JP-A-2015-163596, JP-A-2007-510946, and JP-A-2013-114131. Publication WO 2005/045485, Lub et al. Recl. Trav. Chim. Those described in Pays-Bas, 115, 321-328 (1996) and the like.

  The content of the polymerizable liquid crystal compound in the polarizing film is preferably 70 to 99.5% by mass, more preferably 75 to 99% by mass, and further preferably 75 to 99% by mass from the viewpoint of enhancing the alignment of the polymerizable liquid crystal compound. Preferably it is 80-97 mass%, especially preferably 83-95 mass%.

  The polarizing film can be provided by coating a polarizing film composition paint. The polarizing film composition paint may contain a solvent, a polymerization initiator, a sensitizer, a polymerization inhibitor, a leveling agent, a polymerizable non-liquid crystal compound, a crosslinking agent, and the like.

  As the solvent, those exemplified as the solvent for the alignment layer coating solution are preferably used.

  The polymerization initiator is not limited as long as it can polymerize a polymerizable liquid crystal compound, but a photopolymerization initiator that generates an active radical by light is preferable. Examples of the polymerization initiator include benzoin compounds, benzophenone compounds, alkylphenone compounds, acyl phosphine oxide compounds, triazine compounds, iodonium salts and sulfonium salts.

  The sensitizer is preferably a photosensitizer, and examples thereof include xanthone compounds, anthracene compounds, phenothiazine, rubrene and the like.

  Examples of the polymerization inhibitor include hydroquinones, catechols and thiophenols.

  As the polymerizable non-liquid crystal compound, those copolymerized with the polymerizable liquid crystal compound are preferable. For example, when the polymerizable liquid crystal compound has a (meth) acryloyloxy group, (meth) crates may be mentioned. The (meth) acrylates may be monofunctional or polyfunctional. By using polyfunctional (meth) acrylates, the strength of the polarizing film can be improved. When a polymerizable non-liquid crystal compound is used, it is preferably 1 to 15% by mass, more preferably 2 to 10% by mass, and particularly preferably 3 to 7% by mass in the polarizing film. If it exceeds 15% by mass, the degree of polarization may decrease.

  Examples of the crosslinking agent include a polymerizable liquid crystal compound and a compound capable of reacting with a functional group of a polymerizable non-liquid crystal compound, and an isocyanate compound, melamine, an epoxy resin, an oxazoline compound, and the like.

  The polarizing film composition is provided directly on the substrate film or the alignment layer, and then dried, heated and cured as necessary to provide the polarizing film.

  As a coating method, as a coating method, a known method such as a coating method such as a gravure coating method, a die coating method, a bar coating method or an applicator method, or a printing method such as a flexo method is adopted.

  Drying directs the base film after application to a warm air dryer, an infrared dryer, etc., and 30-170 degreeC, More preferably, it is 50-150 degreeC, More preferably, it is 70-130 degreeC. The drying time is preferably 0.5 to 30 minutes, more preferably 1 to 20 minutes, and still more preferably 2 to 10 minutes.

  The heating can be performed to more strongly orient the dichroic dye and the polymerizable liquid crystal compound in the polarizing film. The heating temperature is preferably in the temperature range in which the polymerizable liquid crystal compound forms a liquid crystal phase.

When the polarizing film composition paint contains a polymerizable liquid crystal compound, it is preferable to cure. As a curing method, heating and light irradiation may be mentioned, and light irradiation is preferable. By curing, the dichroic dye can be fixed in an oriented state. Curing is preferably performed in a state in which a liquid crystal phase is formed in the polymerizable liquid crystal compound, and light curing may be performed at a temperature at which the liquid crystal phase is exhibited.
The light in light irradiation includes visible light, ultraviolet light and laser light. Ultraviolet light is preferred in terms of ease of handling.

  The irradiation intensity varies depending on the type and amount of the polymerization initiator and the resin (monomer), but is preferably 100 to 10,000 mJ / cm 2, and more preferably 200 to 5,000 mJ / cm 2 on the basis of 365 nm.

  By applying a polarizing film composition paint on the alignment layer, the polarizing film is oriented along the alignment direction of the alignment layer, and as a result, it has a polarized light transmission axis in a predetermined direction. When it coats a base material directly, without providing, it can also be made to orientate a polarizing film by irradiating polarization light and hardening composition for polarizing film formation.

  The thickness of the polarizing film is 0.1 to 5 μm, preferably 0.3 to 3 μm, and more preferably 0.5 to 2 μm.

(Lamination of polarizer and substrate film)
It is also preferable to provide a polarizing layer according to the above method on another releasable film, and to transfer the same to the base film, as well as a method in which an alignment layer or a polarizing layer is directly provided on the base film and laminated. It is a method. As a mold release film, the mold release support base material used by the above-mentioned release support base material laminated | stacked with the mold release support base material mentioned above is mentioned as a preferable example, A polyester film, a polypropylene film, etc. are mentioned. And particularly preferable release films. The release film may be subjected to a corona treatment, or provided with a release coat, an easy adhesion coat or the like to adjust the peeling force.

  The method for transferring the polarizing layer to the substrate film is also the same as the method for the releasable support substrate laminated polarizer laminated with the releasable support substrate described above.

  The thickness of the liquid crystalline polarizer is preferably 0.1 to 7 μm, more preferably 0.3 to 5 μm, and particularly preferably 0.5 to 3 μm. The thickness of the adhesive or pressure-sensitive adhesive is preferably 1 to 10 μm, more preferably 2 to 5 μm.

  In the case of the wire grid system, fine conductive wires may be provided on the laminated film of the present invention. When a fine groove is required to provide a fine conductive wire, a layer for providing a groove may be separately provided, or a layer for providing a groove may be an optical isotropic layer in the present invention.

  The angle between the transmission axis of the polarizer and the slow axis of the laminated film is not particularly limited, but the laminated film is used as a polarizer protective film of a polarizing plate for converting ordinary transmitted light into linearly polarized light. Are preferably parallel or perpendicular. “Parallel or vertical” is acceptable from 0 ° or 90 ° to preferably ± 10 °, even ± 7 °, in particular ± 5 °.

  In addition, when the laminated film is used as a polarizer protective film of a polarizing plate that emits light depolarized when used on the viewing side of an image display device, the transmission axis of the polarizer and the slow axis of the laminated film The angle formed is preferably 20 to 70 degrees, more preferably 25 to 65 degrees, still more preferably 30 to 60 degrees, and particularly preferably 35 to 55 degrees.

  In the above, the surface on which the polarizer of the laminated film of the present invention is laminated may be either a substrate film surface or an optically isotropic layer surface.

  Among these, it is composed of a polarizer (base laminate stretching polarizer) uniaxially stretched with a base material to adsorb iodine and an organic dichroic dye, in that the polarizing plate can be made thin, and a liquid layer compound Polarizers are preferred.

(Retardation layer)
It is preferable to provide a retardation layer on the side opposite to the laminated film of the polarizer. The phase difference layer is preferably made of a liquid crystal compound in that the thickness can be reduced. As a liquid crystal compound, a rod-like liquid crystal compound, a discotic liquid crystal compound, or the like can be used according to the purpose, such as a raw or negative A plate, a positive or negative C plate, an O plate or the like.

  When used as optical compensation of a liquid crystal display device, the degree of retardation is appropriately set according to the type of liquid crystal cell and the properties of the liquid crystal compound used in the cell. For example, in the case of the TN system, an O-plate using discotic liquid crystal is preferably used. In the case of the VA system or the IPS system, a C plate or an A plate using a rod-like liquid crystal compound or a discotic liquid crystal compound is preferably used. In the case of the λ / 4 retardation layer or the λ / 2 retardation layer of the circularly polarizing plate, a rod-like compound is preferably used to form an A plate. These retardation layers may be used not only in a single layer but also in combination in a plurality of layers.

  As a liquid crystal compound used for these retardation layers, a polymerizable liquid crystal compound having a polymerizable group such as a double bond is preferable from the viewpoint that the alignment state can be fixed.

Examples of rod-like liquid crystal compounds include: JP-A-2002-030042, JP-A-2004-204190, JP-A-2005-263789, JP-A-2007-119415, JP-A-2007-186430, and the like. The rod-shaped liquid crystal compound which has a polymeric group described in the Hei 11-513360 gazette is mentioned.
As a specific compound,
_{CH 2 = CHCOO- (CH 2)} mO-Ph 1 -COO-Ph 2 -OCO-Ph 1 -O- (CH 2) n-OCO-CH = CH 2
_{CH 2 = CHCOO- (CH 2)} mO-Ph 1 -COO-NPh-OCO-Ph 1 -O- (CH 2) n-OCO-CH = CH 2
CH ₂ = CHCOO- (CH ₂ ) mOP ₁ h-COO-Ph ₂ -OCH _{3
CH 2 = CHCOO- (CH 2)} mO-Ph 1 -COO-Ph-Ph-CH 2 CH (CH 3) C 2 H 5
m and n are positive numbers of 2 to 6
Ph ₁ , Ph ₂ : 1,4-phenyl group (Ph ₂ may have a methyl group at 2-position)
NPh: 2, 6-naphthyl group is mentioned.
These are commercially available from BASF AG as LC 242 etc. and can be used.

  These rod-like liquid crystal compounds may be used in combination of two or more kinds in any ratio.

  Furthermore, examples of the discotic liquid crystal compound include benzene derivatives, tolxene derivatives, cyclohexane derivatives, azacrown-based and phenylacetylene-based macrocycles, and various compounds are described in JP-A-2001-155866. Is preferably used. Among them, a compound having a triphenylene ring represented by the following general formula is preferably used as the discotic compound.

Ｒ_１〜Ｒ_６はそれぞれ独立して水素、ハロゲン、アルキル基、−O−Ｘ；Ｘは、アルキル基、アシル基、アルコキシベンジル基、エポキシ変性アルコキシベンジル基、アクリロイルオキシ変性アルコキシベンジル基、アクリロイルオキシ変性アルキル基、又は下記の指式で示される基である。

R _{1 to} R ₆ each independently represent hydrogen, a halogen, an alkyl group, —O—X; X represents an alkyl group, an acyl group, an alkoxybenzyl group, an epoxy-modified alkoxybenzyl group, an acryloyloxy-modified alkoxybenzyl group, an acryloyloxy It is a modified alkyl group or a group shown by the following finger system.

（ここで、ｍは４〜１０であることが好ましい）

(Here, m is preferably 4 to 10)

  The retardation layer can be provided by coating a composition paint for retardation layer. The composition coating for retardation layer may contain a solvent, a polymerization initiator, a sensitizer, a polymerization inhibitor, a leveling agent, a polymerizable non-liquid crystal compound, a crosslinking agent, and the like. As these, those described for the alignment layer and the liquid crystal polarizer can be used.

  The composition for a retardation layer is directly coated on a polarizer (in the case of a transfer type, on a base film) or on an orientation layer, and then dried, heated and cured to provide a polarizing film. These conditions are also used as the conditions described for the alignment layer and the liquid crystal polarizer.

  The lamination of the retardation layer on the polarizer surface may be performed by applying a liquid crystal compound or an alignment layer to the polarizer, but the retardation layer may be provided on another releasable film according to the above method, It is also a preferred method to transfer this onto a polarizer. In the case of a plurality of retardation layers, it is not necessary to provide all the retardation layers by transfer, and the first layer on the polarizer is provided by coating on the polarizer, and the second layer on it is provided by transfer. It is good. The first layer and the second layer may be separately transferred, and the first layer and the second layer may be laminated on a release film (release substrate / second layer / first layer) and transferred. You may.

  A protective layer may be provided between the polarizer and the retardation layer. Disturbance of the polarizer due to the solvent in the case of providing the retardation layer by providing the protective layer or the solvent of the adhesive or adhesive used in transfer, or the influence on the polarizer due to the retardation layer, the adhesive layer or the additive of the adhesive It can prevent. In addition, a protective layer may be provided on the retardation layer or between the retardation layers. Similarly, it is possible to prevent the influence of the solvent, the effect of the adhesive and the adhesive when the adhesive and the adhesive are provided on the phase difference layer surface, for example, the effect of the solvent when the upper layer is coated .

  As a protective layer, the coated layer of transparent resin is mentioned. The transparent resin is not particularly limited to polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyester, polyurethane, polyamide, polystyrene, acrylic resin, epoxy resin and the like. A crosslinking agent may be added to these resins to form a crosslinked structure. Moreover, what hardened | cured the photocurable compositions, such as an acryl, may be used.

(Liquid crystal display device)
These polarizing plates can be used on the light source side polarizing plate of the liquid crystal display device, on either side as a viewing side polarizing plate, or on both sides. The polarizing plate is used by bonding the laminated film to the liquid crystal cell with the outer side. The bonding is preferably a substrate-less optical pressure-sensitive adhesive.

  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 polarizing plate having the retardation layer of the present invention is reduced to a level at which iridescence can not be recognized even in a liquid crystal display device having a light source having a sharp peak, and the half value width of the light emission peak of each color is narrow. The combination is a more preferred form. As the half width of the light source, the narrowest peak of the 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 width is 0.5 nm in terms of realistic values and measuring instrument resolution. Specifically, a QD light source or a light source using a KSF phosphor for a red region is mentioned as a suitable light source, and a KSF phosphor is used as one suitable light source.

  When the polarizing plate having the retardation layer of the present invention is used in accordance with the recent reduction in thickness, the thickness of the polarizing plate having the retardation layer is also preferably 20 to 80 μm, more preferably 25 to 70 μm. 28 to 60 μm. (Note that the thickness of the polarizing plate having a retardation layer as referred to herein means the thickness from the retardation layer to the laminated film, and a protective coating on a surface coating layer such as an antireflection layer of the laminated film or the like. Although layers are included, adhesive layers and adhesive layers for laminating a polarizing plate with other members are not included, and in the case of such a thin display, a light source of blue light emitting diode and yellow phosphor, A light source using a KSF phosphor, a QD light source, a white organic EL light source, and the like are preferable.

(EL display device)
The polarizing plate of the present invention can also be suitably used as a circularly polarizing plate for preventing reflection of an EL display device or the like. In order to form a circularly polarizing plate, the retardation layer is preferably a quarter wavelength layer. The in-plane retardation of the 1⁄4 wavelength layer is preferably 100 to 180 nm, more preferably 120 to 150 nm.

  In addition, the quarter wavelength layer alone may not be a quarter wavelength in a wide wavelength range of visible light, and may be colored. In such a case, a half-wave layer may be further provided. In this case, it is preferable to provide a half-wave layer between the polarizer and the quarter-wave layer. 200-360 nm of the front retardation of a 1/2 wavelength layer is preferable, More preferably, it is 240-300 nm.

  When only a quarter wavelength layer is used as a circularly polarizing plate, the orientation axis (slow axis) of the quarter wavelength layer and the transmission axis of the polarizer are preferably 35 to 55 degrees, more preferably 40 degrees to 50 degrees, More preferably, it is 42 to 48 degrees.

  When combining a quarter wavelength layer and a half wavelength layer as a circularly polarizing plate, the angle (θ) of the orientation axis (slow axis) of the half wavelength layer and the transmission axis of the polarizer is 5 to 20 degrees Is preferred, and more preferably 7 to 17 degrees. The angle between the orientation axis (slow axis) of the half wavelength layer and the orientation axis (slow axis) of the quarter wavelength layer is preferably in the range of 2θ + 45 degrees ± 10 degrees, more preferably 2θ + 45 degrees ± 5 degrees And more preferably in the range of 2θ + 45 degrees ± 3 degrees. These angles can be controlled by the angle of rubbing or the irradiation angle of polarized ultraviolet light.

  Furthermore, it is also a preferable form to provide a C plate layer on the 1⁄4 wavelength layer in order to reduce a change in coloring when viewed obliquely. As the C plate layer, a positive or negative C plate layer is used in accordance with the characteristics of the quarter wavelength layer or the half wavelength layer.

As a method of laminating these retardation layers, for example, the following can be mentioned as long as it is a half wave layer and a quarter wave layer.
A half-wave layer is provided on the polarizer by transfer, and a quarter-wave layer is further provided on the half-wave layer by transfer.
A quarter wavelength layer and a half wavelength layer are provided in this order on the release film, and this is transferred onto the polarizer.
A half-wave layer is provided on the polarizer by coating, and a quarter-wave layer is provided by transfer.
A half-wave layer is provided on the polarizer by coating, and a quarter-wave layer is further provided by coating.
Various methods such as can be adopted.

  In addition, also in the case of laminating a C plate, a method of providing a C plate layer by coating or transferring on a quarter wavelength layer provided on a polarizer, a quarter wavelength layer to be transferred or pasted, quarter wavelength Various methods such as a method of pre-stacking on layers can be adopted.

  The thickness of the circularly polarizing plate obtained in this manner is preferably 100 μm or less. Further, the thickness is preferably 80 μm or less, particularly preferably 70 μm or less, and most preferably 60 μm or less.

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 F16 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 F14 provided the optically isotropic layer on both surfaces.

  A solution of Byron (registered trademark) 200 (RV 200) (made by Toyobo Co., Ltd.) in a 20% toluene / methyl ethyl ketone mixed solvent is applied to the uneven surface of a 20 cm × 30 cm roughened film B2 and then dried. Provided. The optically isotropic layer surfaces of the obtained two optically isotropic layer laminated films are overlapped, passed between rolls heated to 100 ° C., and passed between two rolls of the optically isotropic layer laminated film, and the optically isotropic layer laminated film I got F17. In addition, in the case of bonding, it bonded together so that the slow axis of roughening film B2 might become parallel. The refractive index of the Byron 200 is 1.55.

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

(Evaluation of laminated film)
(Observation of rainbow blotches under cross nicol)
The laminated film was placed between two polarizing plates arranged in cross nicol so that the slow axis of the base film was 45 degrees to the transmission axis of the polarizing plate on the light source side, and was about 60 cm from the polarizing plate on the viewing side The state of the transmitted light was observed from the front, 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 optically isotropic layer of the laminated film was on top, and a halogen lamp was irradiated from below, and the degree of whitening of the laminate was evaluated from the direction of 45 degrees diagonally upward according to the following criteria.
◎: 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.
In Examples 31 to 36, evaluation was performed using a polarizing plate. The results of Examples 31 to 36 are shown in Table 5.

Production of Polarizer A (Single-Layer Polarizer) A polyvinyl alcohol resin film having a saponification degree of 99.9% was introduced into a roll having a difference in peripheral speed, and uniaxial stretching was performed at 100 ° C. at a rate of 3 times. The resulting stretched polyvinyl alcohol stretched film is dyed in a mixed aqueous solution of potassium iodide (0.3%) and iodine (0.05%), and then 1.8 in a 10% aqueous solution of boric acid at 72 ° C. It was uniaxially stretched to double. Thereafter, the resultant was washed with ion-exchanged water, further immersed in a 6% aqueous potassium iodide solution, removed with an air knife, and then dried at 45 ° C. to obtain a polarizer. The thickness of the polarizer was 18 μm.

Production of Polarizer B (Base Laminated Polarizer) A polyester X was used as a thermoplastic resin substrate to prepare a 100 μm-thick unstretched film, and the unstretched film had a degree of polymerization of 2400 and a degree of saponification of 99 on one side. An aqueous solution of 9 mol% polyvinyl alcohol was applied and dried to form a PVA layer. The obtained laminate was stretched and wound in the longitudinal direction twice at 120 ° C. between rolls different in peripheral speed. Next, the resulting laminate is treated with a 4% aqueous boric acid solution for 30 seconds, and then dipped in a mixed aqueous solution of iodine (0.2%) and potassium iodide (1%) for 60 seconds for staining Subsequently, it was treated with a mixed aqueous solution of potassium iodide (3%) and boric acid (3%) for 30 seconds. Furthermore, this laminate is uniaxially stretched in the longitudinal direction in a 72 ° C. aqueous solution of boric acid (4%) and potassium iodide (5%), subsequently washed with a 4% aqueous solution of potassium iodide and the aqueous solution with an air knife. After removing, it was dried in an oven at 80 ° C., and both ends were slit and wound up to obtain a base laminate polarizer 1 having a width of 30 cm and a length of 1000 m. The total draw ratio was 6.5 times, and the thickness of the polarizer was 5 μm. In addition, the thickness embedded the base material lamination | stacking polarizer in an epoxy resin, cut out the slice, observed and read it with the optical microscope.

Method for producing polarizer C (liquid crystal compound polarizer (rubbing treatment)) (formation of rubbing alignment layer)
The coating for rubbing alignment layer of the following composition was applied to the laminated film using a bar coater, and dried at 120 ° C. for 3 minutes to form a film having a thickness of 200 nm. Subsequently, the surface of the obtained film was rubbed with a nylon blanket. The orientation control direction was adjusted by the rubbing direction.

Coating for rubbing alignment layer Completely saponified polyvinyl alcohol Molecular weight 800 2 parts by mass Ion-exchanged water 100 parts by mass

(Synthesis of polymerizable liquid crystal compound)
As described in paragraph [0134] of JP-A-2007-510946, and in Lub et al. Recl. Trav. Chim. The compounds of the following formula (A: upper stage) and (B: lower stage) were synthesized with reference to Pays-Bas, 115, 321-328 (1996).

  The dye (C) of the following formula was synthesized with reference to Example 1 of JP-A-63-301850.

  A dye (d) of the following formula was synthesized with reference to Example 2 of JP-B-5-49710.

  With reference to the method for producing the compound of the general formula (1) of JP-B-63-1357, a dye (E) of the following formula was synthesized.

(Formation of polarizing film)
75 parts by mass of compound (a), 25 parts by mass of compound (b), 2.5 parts by mass of dye (c), 2.5 parts by mass of dye (d), 2.5 parts by mass of dye (e), IRGACURE (R) A coating for a polarizing film consisting of 6 parts by mass of 369 E (manufactured by BASF Corp.) and 250 parts by mass of ortho-xylene was applied using a bar coater and dried at 110 ° C. for 3 minutes to form a 2 μm thick film. Subsequently, UV light was irradiated to provide a polarizer made of a liquid crystal compound.

Method for producing polarizer D (liquid crystal compound polarizer (photo alignment)) (synthesis of paint for photo alignment layer)
Based on the description of Example 1, Example 2, and Example 3 of JP-A-2013-33248, a 5% by mass solution of cyclopentanone in a polymer (F) of the following formula was produced.

偏光子Ｅ（転写型液晶化合物偏光子）の製造方法
基材として二軸延伸ポリエステルフィルムを用いた以外は偏光子Ｃと同様にした。

A method for producing a polarizer E (transfer type liquid crystal compound polarizer) The same as the polarizer C was used except that a biaxially stretched polyester film was used as a substrate.

(Formation of photo alignment layer)
The coating for the photoalignment layer of the above composition was applied to the laminated film using a bar coater, and dried at 80 ° C. for 1 minute to form a film having a thickness of 150 nm. Subsequently, polarized UV light was irradiated to laminate a photoalignment layer. The orientation control direction was controlled by the polarization direction of UV.

Production of λ / 4, λ / 2 Composite Phase Difference Layer Transfer Film A 50 μm-thick biaxially stretched polyethylene terephthalate (PET) film was rubbed as a substrate. A solution for forming a retardation layer was applied to the rubbing-treated surface by a bar coat method, dried and oriented, and then irradiated with ultraviolet rays to be cured, thereby providing a 1⁄4 wavelength layer on the biaxially stretched polyethylene terephthalate film. Furthermore, polyvinyl alcohol (polyvinyl alcohol 1000 completely saponified 2% by mass aqueous solution (0.2% surfactant)) was coated on the 1⁄4 wavelength layer and dried to obtain a polyvinyl alcohol film having a thickness of about 100 nm. Subsequently, the surface of the polyvinyl alcohol film was rubbed, a solution for forming a retardation layer was applied by a bar coat method to the rubbed surface of PVA, dried and oriented, and then irradiated with ultraviolet rays to be cured. A half-wave layer was provided so that the angle between the rubbing direction when providing the quarter-wave layer and the rubbing direction when providing the half-wave layer was 60 degrees.

Solution for forming a retardation layer LC242 (manufactured by BASF Corp.) 75 parts by mass 20 parts by mass of the following compound

トリメチロールプロパントリアクリレート ５質量部
イルガキュア３７９ ３質量部
界面活性剤 ０．１質量部
メチルエチルケトン ２５０質量部

Trimethylolpropane triacrylate 5 parts by weight Irgacure 379 3 parts by weight Surfactant 0.1 part by weight Methyl ethyl ketone 250 parts by weight

Production of λ / 4 phase difference layer transfer film Polyvinyl alcohol (Polyvinyl alcohol 1000 complete saponification type 2% by mass aqueous solution (0.2% surfactant)) is coated on a 50 μm thick biaxially stretched polyethylene terephthalate (PET) film, and dried Then, a polyvinyl alcohol film having a thickness of about 100 nm was obtained, and the surface of the polyvinyl alcohol film was subjected to rubbing treatment, and a solution for forming a retardation layer was applied to the rubbing treated surface of PVA by a bar coating method. After drying and alignment treatment, ultraviolet light was irradiated and cured to provide a λ / 4 wavelength layer.

  In these cases, the retardation was controlled by the thickness of the retardation layer. The thickness of the retardation layer was 1.2 μm for the quarter wavelength layer and 2.3 μm for the half wavelength layer.

Examples 1 to 26, Comparative Examples 1 to 6
A commercially available ultraviolet curable acrylic adhesive was applied to the base film surface or the optically isotropic layer surface of the laminated films F1 to F17 with an applicator. The polarizer surface of the polarizer B (base laminate polarizer) was bonded to this coated surface, and a high-pressure mercury lamp was irradiated from the laminate film surface to be cured. Thereafter, the substrate film of the substrate laminated polarizer was peeled off to laminate the polarizer. The slow axis of the base film of the laminated film and the light transmission axis of the polarizer were parallel to each other. A commercially available optical pressure-sensitive adhesive sheet is attached to this polarizer, the retardation surface of the transfer type λ / 4, λ / 2 composite retardation layer transfer film is attached to the optical pressure-sensitive adhesive surface, and the PET film of the substrate is peeled off. And a polarizing plate having a retardation layer was obtained. Bonding was performed such that the absorption axis of the polarizer, the alignment direction of the half wavelength layer (the rubbing direction was 15 degrees), and the alignment direction of the quarter wavelength layer (the rubbing direction) were 75 degrees.

Examples 27 to 30
A polarizing plate having a retardation layer was obtained in the same manner as in Examples 4, 5, 17 and 18 except that the slow axis of the base film of the laminated film and the light transmission axis of the polarizer were perpendicular to each other. .

Example 31

  The following high refractive index adhesive k is applied to the uneven surface of the film A1 having the uneven surface so as to have a thickness of 5 μm after drying, and the solvent is removed by heating to remove the solvent. The polarizer surface of the polarizer) was bonded, and a high pressure mercury lamp was irradiated from the laminated film surface to be cured. Thereafter, the substrate film of the substrate laminated polarizer was peeled off to laminate the polarizer. After that, λ / 4 and λ / 2 composite retardation layers were laminated in the same manner as above.

Preparation of high refractive index adhesive k 30 parts by mass of 2-ethylhexyl acrylate, 70 parts by mass of ethoxylated o-phenylphenol acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., product name: A-LEN-10) and 0. 25 parts by mass of azobisisobutyronitrile was reacted in ethyl acetate to obtain an ethyl acetate solution (solid content concentration: 30% by mass) of a copolymer (Mw = 400,000).

Examples 32-34
The coating agents b, e and f for the optical isotropic layer are applied to the uneven surface of the film A1 having the uneven surface to a thickness of 5 μm, and the polarizer of the polarizer B (base laminate polarizer) is coated on this coated surface The surfaces were laminated, and a high pressure mercury lamp was irradiated from the laminated film surface to cure. Thereafter, the substrate film of the substrate laminated polarizer was peeled off to laminate the polarizer. After that, λ / 4 and λ / 2 composite retardation layers were laminated in the same manner as above.
Examples 35 and 36
Example 31 was the same as Example 33 except that B1 was used as a film having an uneven surface.

Example 37
A commercially available ultraviolet curable acrylic adhesive was applied to the optically isotropic layer surface of the laminated film F5 with an applicator. The polarizer surface of the polarizer E (transfer type liquid crystal compound polarizer) was bonded to this coated surface, and a high pressure mercury lamp was irradiated from the laminated film surface to be cured. Then, the base film of the transfer type liquid crystal compound polarizer was peeled off, and the polarizer was laminated. The slow axis of the base film of the laminated film and the light transmission axis of the polarizer were parallel to each other. A commercially available optical pressure-sensitive adhesive sheet was attached to the polarizer surface, the retardation surface of the transfer type λ / 4 retardation layer transfer film was attached to the optical pressure-sensitive adhesive surface, and the PET film of the substrate was peeled off. Bonding was performed such that the absorption axis of the polarizer and the alignment direction (rubbing direction) of the 1⁄4 wavelength layer were 45 degrees.

Example 38
A polarizer C (a liquid crystal compound polarizer (rubbing treatment)) was provided on the optically isotropic layer surface of the laminated film F5. Subsequently, in the same manner as in Example 37, a λ / 4 layer was provided.

Example 39
A polarizer D (liquid crystal compound polarizer (photo alignment)) was provided on the optically isotropic layer surface of the laminated film F5. Subsequently, in the same manner as in Example 37, a λ / 4 layer was provided.

Examples 40-42
A polarizer-retardation layer was provided on the base film surface of the designated laminated film F6 in the same manner as in Examples 37 to 39.

Example 43
Example 5 was the same as Example 5 except that the slow axis of the base film of the laminated film and the light transmission axis of the polarizer were 45 degrees.

Example 44
A polarizer C (liquid crystal compound polarizer (rubbing treatment)) was provided on the base film surface of the laminated film F6 such that the slow axis of the base film and the light transmission axis of the polarizer were 45 degrees. Furthermore, a λ / 4 layer was provided on the polarizer in the same manner as in Example 37.

Preparation of hard coat layer, low refractive index layer, high refractive index layer (composition for low refractive layer)
Pertron (TM) A-2508LR (manufactured by Pelnox Co., Ltd. hollow silica-containing type, refractive index 1.33 (Abbe method))
(Composition for high refractive layer)
Pertron (TM) A-2300 (Pernox Corporation refractive index 1.65 (Abbe method))
(Composition for hard coat)
Pertron (TM) A-2005 (Pernox Corporation)

  The above composition was coated on a target film with a bar coater, dried at 80 ° C., the solvent was removed, and ultraviolet rays were irradiated with a high pressure mercury lamp to be cured. In these compositions, Irgacure 184 (3% by mass, solid content) was used as a photopolymerization initiator. In the case of reducing the film thickness, it was adjusted by diluting with methyl isobutyl ketone.

Example 45
The low refractive index layer (3 micrometers in thickness) was provided in the base film surface of laminated | multilayer film F5. The other conditions were the same as in Example 5.

Example 46
A hard coat layer (3 μm in thickness) was provided on the base film surface of the laminated film F5, and a high refractive index layer (130 nm in thickness) and a low refractive index layer (86 nm in thickness) were further provided thereon. The other conditions were the same as in Example 5.

Example 47
Example 19 was carried out in the same manner as Example 19 except that a low refractive index layer (thickness 85 nm) was provided on the optically isotropic layer surface of the laminated film F6.

Example 48
Example 45 was carried out in the same manner as Example 45 except that a polarizer A (single-layer polarizer) was used as a polarizer.

  It evaluated by peeling off the circularly-polarizing plate of the portable terminal using commercially available organic EL, and putting the circularly-polarizing plate obtained above instead. The transmission axis direction of the polarizer of the circularly polarizing plate was made to be the same as the transmission axis direction of the original circularly polarizing plate. Evaluation observed the confirmation of the rainbow mark and the contrast of the image.

(Evaluation of circularly polarizing plate)
It evaluated by peeling off the circularly-polarizing plate of the portable terminal using commercially available organic EL, and putting the circularly-polarizing plate obtained above instead. The transmission axis direction of the polarizer of the circularly polarizing plate was made to be the same as the transmission axis direction of the original circularly polarizing plate. Evaluation observed the confirmation of the rainbow mark and the contrast of the image.

(Observation of rainbow blotches)
The display on the display was all white, and the presence of rainbow marks was confirmed by viewing from the front and the diagonal direction.
○: Rainbow spots were not observed Δ: Slight rainbow spots were observed ×: Rainbow spots were observed

(Observation of contrast)
The display on the display was a landscape image, and the fluorescent light from the tabletop was illuminated from above to observe the contrast from the front.
◎: vivid contrast remained.
○: A slight decrease in contrast was observed due to scattered light.
Δ: A decrease in contrast was observed, but observation of the image was possible.
X: Scattered light made the image difficult to see

(Anti-reflection effect)
○: The brightness of the drive wiring was recognized.
X: The brightness of the metal wiring was not noticeable.

(Depolarization)
Polarized sunglasses were worn and observed at an angle where the transmission axis of the polarizer was horizontal.
○: There was no blackout.
X: Blacked out and the screen disappeared.

  The configuration of each example and the evaluation results 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＊：偏光子を積層した表面
７＊：白化評価
８＊： 偏光子
９＊：偏光子の透過軸と基材フィルムの遅相軸との角度
１０＊：位相差層
１１＊：画像コントラスト
１２＊：虹斑評価
１３＊：反射防止効果
１４＊：偏光解消性

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 laminated with polarizer 7 *: Whitening evaluation 8 *: Polarizer 9 *: Angle 10 * between transmission axis of polarizer and slow axis of base film 10: retardation layer 11 *: image contrast 12 *: rainbow blotch evaluation 13 *: antireflection effect 14 *: Depolarization

  With the polarizing plate 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)

The laminated film which has a base film and an optical isotropic layer which has following feature (a)-(c), the polarizing plate which has a retardation layer which consists of a polarizer and a liquid crystal compound in this order.
(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 liquid crystal display device comprising the polarizing plate according to claim 1. An organic EL display device having the polarizing plate according to claim 1.