JP7238325B2 - LAMINATED FILM AND POLARIZING PLATE USING THE SAME - Google Patents

Description

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

It has been known that when a birefringent film such as a polyester film is used under the environment of a fluorescent lamp or a cold cathode tube light source, iridescence caused by retardation occurs. Therefore, optically isotropic cellulose-based films have been used as protective films for polarizers used in liquid crystal displays and the like.

Recently, a technique has been proposed to eliminate iridescence by combining a film having a high retardation with a white light source having a continuous emission spectrum (e.g., Patent Document 1, Patent Document 2, etc.), which is compatible with polarized sunglasses. It has been put to practical use as a depolarizing film or a polarizer protective film in liquid crystal displays and the like. However, this technology is improved when using a light source with a sharp emission peak in the red region of the emission spectrum, such as a cold cathode tube light source or a KSF phosphor (a phosphor in which Mn is added to K ₂ SiF ₆ crystal). There was room for In addition, the film needs to be thick in order to ensure a high retardation, and there is a fear that it will not be able to sufficiently cope with the thinning of image display devices in recent years.

As a depolarizing film for a liquid crystal display using a light source with a steep emission peak, by providing unevenness on the surface of the film having birefringence, it is possible to locally reduce the wavelength to λ/4 or more within a region smaller than the level visible to the naked eye. A film in which retardation is generated has been proposed (for example, Patent Document 3). However, such prior art has the problem that the screen is white and the image is difficult to see in an environment of low contrast and strong external light.

JP 2011-215646 A WO2011/162198 JP 2017-161599 A

The present invention has been made against the background of such problems of the prior art. That is, the object of the present invention is to provide a polarizing plate with a retardation layer that can suppress iridescence and ensure high transparency and clear image displayability when used in an environment with a light source having a steep emission peak. to provide.

The present inventor has completed the present invention as a result of intensive studies to achieve this object.
That is, the present invention includes the following aspects.
Section 1.
A polarizing plate comprising, in this order, a laminate film having a substrate film and an optically isotropic layer, a polarizer, and a retardation layer made of a liquid crystal compound, which have the following characteristics (a) to (c).
(a) At least one surface of the substrate film is uneven, and the arithmetic mean roughness (Ra) of the uneven surface is 0.2 to 10 μm.
(b) The refractive index anisotropy (Bfnx-Bfny) of the base film is from 0.04 to 0.2.
(c) An optically isotropic layer is provided on the uneven surface of the base film, and the refractive index of the optically isotropic layer is from Bfny−0.15 to Bfnx+0.15.
(However, the refractive index in the slow axis direction of the base film is Bfnx, and the refractive index in the fast axis direction is Bfny.)
Section 2.
A liquid crystal display device comprising the polarizing plate according to Item 1.
Item 3.
An organic EL display device comprising the polarizing plate according to Item 1.

The polarizing plate of the present invention can suppress iridescence and ensure high transparency and vivid image display properties when used in an environment of a light source having a steep emission peak. In one embodiment, the polarizing plate with a retardation layer of the present invention is suitable for thinning, and can be used as a polarizing plate integrated with an optical compensation function for a liquid crystal display device, or as a circular antireflection plate for an organic EL display device or the like. It can be suitably used as a polarizing plate.

The polarizing plate comprises, in this order, a laminated film having a refractive index anisotropic base film having an uneven surface (roughened surface) and an optically isotropic layer, a polarizer, and a retardation layer made of a liquid crystal compound. is preferred. Hereinafter, the term "laminated film" simply means a laminated film of an optically isotropic layer and a refractive index anisotropic base film having an uneven surface (roughened surface). Also, a laminated film with a polarizer laminated thereon may be referred to as a "polarizer laminated film".
(Base film)
First, the base film will be explained.

At least the base film is not particularly limited as long as it can have refractive index anisotropy, and examples thereof include polyester, polyamide, polystyrene, syndiotactic polystyrene, polyamide, and polycarbonate. Among them, polyester is preferable because a film having high refractive index anisotropy can be easily obtained. Examples of polyester include polyethylene terephthalate, polyethylene naphthalate, polytetramethylene terephthalate, polytrimethylene terephthalate, etc. Among them, polyethylene terephthalate and polyethylene naphthalate are preferred. These polyesters include terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, cyclohexanedicarboxylic acid, and ethylene glycol, as long as they do not impair the mechanical properties, heat resistance, and dimensional stability of the film (for example, 10 mol % or less). . For example, in the case of a polyethylene terephthalate polymer, 1 to 2 mol of diethylene glycol, which is a by-product, is usually copolymerized during polymerization, and such a by-product may be contained.

The base film has birefringence. The lower limit of the slow axis 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 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 direction refractive index (Bfny) of the base film is preferably 1.62, more preferably 1.61, still more preferably 1.6.

The lower limit of the refractive index anisotropy (ΔBfNxy=Bfnx−Bfny) of the substrate 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, iridescence 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. When the upper limit is 0.2 or less, the mechanical strength in the fast axis direction can be adjusted within a practical range, and production is facilitated. The refractive index of the base film is a value measured under the condition of a wavelength of 589 nm.

The lower limit of the thickness of the base film before providing the uneven surface (before roughening) is preferably 15 μm, more preferably 20 μm, and still more preferably 25 μm. If the lower limit is 15 μm or more, excellent mechanical strength is obtained even if the thickness is reduced when the unevenness is imparted. The upper limit of the thickness of the base film before the uneven surface is provided is preferably 200 μm, more preferably 150 μm, still more preferably 100 μm, particularly preferably 90 μm, and most preferably 80 μm. If the upper limit is 200 μm or less, it is excellent in handleability and suitable for thinning (eg, for use in thin image display devices).

The lower limit of the in-plane retardation (Re) of the substrate film before imparting the uneven surface is preferably 2000 nm, more preferably 2500 nm, even more preferably 3000 nm, particularly preferably 3500 nm, most preferably 4000 nm. is. When the lower limit is 2000 nm or more, iridescence can be eliminated more effectively. The upper limit of the in-plane retardation (Re) of the substrate film before imparting the uneven surface is preferably 30000 nm, more preferably 20000 nm, even more preferably 15000 nm, still more preferably 12000 nm, and particularly preferably 10000 nm, more preferably 9000 nm, most preferably 8000 nm, most 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) between the in-plane retardation (Re) and the thickness direction retardation (Rth) of the base film before the uneven surface is imparted is preferably 0.2, more preferably 0.5, and even more preferably. is 0.6. When the lower limit is 0.2 or more, iridescence can be eliminated more effectively. The upper limit of Re/Rth of the base film before the rough surface is provided is preferably 2, more preferably 1.5, still more preferably 1.2, and particularly preferably 1 from the viewpoint of mechanical strength.

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

The lower limit of the plane orientation degree ΔP of the substrate film is preferably 0.08, more preferably 0.09, and still more preferably 0.1. When the lower limit is 0.08 or more, not only can iridescence be effectively eliminated, but also thickness unevenness of the film can be reduced. The upper limit of the plane orientation degree ΔP of the substrate film is preferably 0.15, more preferably 0.14, and still more preferably 0.13. When the upper limit is 0.15 or less, the refractive index anisotropy can be kept higher.

The substrate film is preferably uniaxially oriented in order to have refractive index anisotropy. Orientation can be carried out by a normal method suitable for each resin. For example, if the melted resin is extruded on a cooling roll to form a sheet, the cooling roll is set to a speed higher than the speed of the extruded resin, and the unstretched film that has been melted and extruded is heated. Examples include a method of stretching and orienting the film in the longitudinal direction with a group of rolled rolls, and a method of stretching and orienting the unstretched film melted and extruded in the transverse direction or oblique direction by heating in a tenter.

Among these, the method of orienting the base film includes a method of stretching and orienting a melted and extruded unstretched film in the longitudinal direction with a group of heated rolls, and a method of stretching the melted and extruded unstretched film. A method of orientation by heating in a tenter and stretching in a horizontal direction or an oblique direction is preferred. 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 transverse 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 orientation in the machine direction, it is weak (about 2.2 times or less) before stretching in the machine direction in order to increase the mechanical strength in the direction perpendicular to the orientation direction and to adjust the shrinkage characteristics. 2) transverse stretching may be added, or weak transverse stretching (about 1.5 times or less) may be added after longitudinal stretching. Similarly, even in the case of orientation in the transverse direction, a weak (about 2.2 times (less than 1.5 times) or weaker (less than about 1.5 times) stretching in the machine direction may be added after the stretching in the transverse direction. Further, in order to further increase the orientation in the orientation direction, the film may be slightly shrunk in the machine direction during or after stretching in the transverse direction. The width after shrinkage is preferably from 0.7 to 0.995 times, more preferably from 0.8 to 0.99 times, particularly preferably from 0.9 to 0.98 times the width during stretching. 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 stretching temperature (and preheating temperature) is preferably 80 to 150° C. both in the machine direction and in the transverse direction. Moreover, after stretching, in order to ensure the heat resistance of the base film, it is preferable to heat set at a temperature higher than the heating temperature during stretching. The heat setting temperature is preferably 150 to 250°C, more preferably 170 to 245°C.

The base film preferably 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, even more 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 keep the light transmittance of the base film at a wavelength of 380 nm to 20% or less, it is desirable to appropriately adjust the type and concentration of the ultraviolet absorber to be blended in the base film, and the thickness of the base film. The ultraviolet absorbent used in the present invention includes organic ultraviolet absorbents and inorganic ultraviolet absorbents. From the viewpoint of transparency, organic UV absorbers are preferred. Examples of organic UV absorbers include benzotriazole-based, benzophenone-based, cyclic iminoester-based, and combinations thereof, but are not particularly limited as long as the light transmittance is within the range described above. From the viewpoint of durability, benzotriazole-based and cyclic iminoester-based are particularly preferred. When two or more ultraviolet absorbers are used in combination, ultraviolet rays of different wavelengths can be absorbed at the same time, so that the ultraviolet absorption effect can be further improved.

In addition to the ultraviolet absorber, it is also preferable to incorporate various additives into the substrate film within a range that does not impair the effects of the present invention. Examples of additives include inorganic particles, heat-resistant polymer particles, alkali metal compounds, alkaline earth metal compounds, phosphorus compounds, antistatic agents, light stabilizers, flame retardants, heat stabilizers, antioxidants, and anti-gelling agents. , surfactants, and the like. These additives can be used alone or in combination of two or more.
Moreover, in order to achieve high transparency, it is also preferred that the base film does not substantially contain particles. The term "substantially contains no particles" means, for example, in the case of inorganic particles, when the inorganic elements in the base film are quantified by fluorescent X-ray analysis, 50 ppm or less, preferably 10 ppm or less, particularly preferably less than the detection limit. means a content of

(Improvement of surface unevenness)
In the present invention, at least one surface of the substrate film has an uneven surface. The uneven surface may be provided only on one side of the base film, or may be provided on both sides. A substrate film having an uneven surface may be referred to as a roughened substrate film.

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

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

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

The lower limit of the maximum height (Ry) of the uneven surface of the roughened substrate film is preferably 2.0 μm, more preferably 3.0 μm, still more preferably 4.0 μm, and particularly preferably 4.5 μm. Yes, most preferably 5.0 μm. The upper limit of Ry is preferably 20 μm, more preferably 17 μm, even 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. be. The upper limit of Rp is preferably 15 μm, more preferably 12 μm, even more preferably 10 μm, particularly preferably 8 μm.

The lower limit of the maximum valley depth (Rv) of the uneven surface of the roughened substrate film is preferably 1.0 μm, more preferably 1.5 μm, even more preferably 2.0 μm, and particularly preferably 2.5 μm. is. The upper limit of Rv is preferably 15 μm, more preferably 12 μm, even 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 limits, iris spots can be eliminated more effectively. Productivity is excellent when the values of Ra, Rq, Rz, Ry, Rp, and Rv are at least the upper limits. Ra, Rq, Rz, Ry, Rp, and Rv are calculated from roughness curves measured using a contact roughness meter in accordance with JIS B0601-1994 or JIS B0601-2001.

By providing unevenness (roughening) on the surface of the base film, a retardation difference is provided in a minute area, and although there is coloring (rainbow spots) due to retardation in each area, the coloring is visually invisible. be able to. This retardation difference ΔRe can be represented 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, most preferably 100 nm. When the lower limit is 30 nm or more, iridescence can be eliminated more effectively. The upper limit of ΔRe is preferably 1500 nm, more preferably 1000 nm, still more preferably 800 nm, particularly preferably 500 nm, most preferably 300 nm. When the upper limit is 1500 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. 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, most preferably 300 μm. is. When the upper limit is 500 μm or less, it is possible to prevent a feeling of coloring or a feeling of flickering due to the retardation of each minute region. Sm is calculated from a roughness curve measured using a contact roughness meter in accordance with JIS B0601-1994.

The base film may become thinner than the original thickness by providing unevenness and roughening the surface. The lower limit of the thickness of the roughened substrate film is preferably 10 μm, more preferably 15 μm, even more preferably 20 μm, particularly preferably 25 μm, and most preferably 30 μm. When the lower limit is 10 μm or more, sufficient strength as a protective film can be ensured. The upper limit of the thickness of the roughened substrate film is preferably 150 μm, more preferably 120 μm, even more preferably 100 μm, particularly preferably 90 μm, and most preferably 80 μm. When the upper limit is 150 μm or less, it is suitable for thinning.
The thickness of the roughened base film is determined by embedding the roughened base film in epoxy resin, cutting out a section of the cross section, and observing it under a microscope. , the thickness is measured at 10 points at equal intervals, and the average value is calculated.

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

The method for providing unevenness is not particularly limited, and conventionally known methods for surface roughening treatment can be used. For example, sandblasting, sandpaper or file, treatment with a whetstone, etc., treatment with a sander (orbital sander, random sander, delta sander, belt sander, disc sander, roll sander, etc.), treatment with a metal brush, etc., chemical etching, mold Examples include shaping by pressing with. Of these, sandblasting, sanding, and chemical etching are preferred.
Sandblasting may be, for example, a method in which a roll-shaped base film is supplied to a centrifugal blast machine and an abrasive is projected 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 rotor blades, and the like. Further, the sandblasting treatment may be a method in which a substrate film is attached to a glass plate, set in air blasting, and an abrasive is blown onto the surface of the substrate film. In this case, the roughness can be adjusted by the type of abrasive, the size of the abrasive, the spraying pressure, the treatment time, and the like.
The treatment with a sander is, for example, a method in which a roll-shaped base film is guided to a conveying device having a roll sander attached to a part of the roll surface of the film conveying roll (roll sander). good. In this case, the roughness can be adjusted by the type of sanding paper, the rotation speed of the roll sander, the transport speed of the film, and the like. Also, the processing direction can be adjusted by the angle between the roll sander and the film, the rotation speed of the roll sander, the transport speed of the film, and the like.
In addition, sanding is performed by attaching urethane foam to a glass plate, then attaching a base film on top of it, and sanding the surface of the base film in four directions: vertical, horizontal, and diagonal (45 degrees, 135 degrees). It may be a method of processing from. Roughness can be adjusted by the type of sanding disk of the sander, processing time, and the like.
In addition, after sanding and sandblasting, the treated surface may be further polished with sandpaper or the like in order to remove local projections.
Chemical etching may be a method of immersing in an acid or alkaline solution, washing with water, peeling off the masking film, and drying. Roughness can be adjusted by immersion time or the like. Chemical etching is basically a double-sided treatment, but in the case of single-sided treatment, for example, a masking film is adhered to one side of the substrate film.

(optical isotropic layer)
An optically isotropic layer is preferably 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 that is not optically detectable, preferably 100 nm or less, more preferably 50 nm or less, and particularly preferably 20 nm or less. If the easy-adhesion layer satisfies the refractive index range of the optical isotropic layer described below, the easy-adhesion layer and the optically isotropic layer provided thereon together are regarded as one optically isotropic layer. be able to. Moreover, if the easy-adhesion layer has a sufficient thickness as an optically isotropic layer, the easy-adhesion layer may be regarded as an optically isotropic layer. By providing the optically isotropic layer, it is possible to reduce diffused reflection due to unevenness on the surface of the base film and ensure transparency. The preferable refractive index of the easy-adhesion layer is the same as the preferable refractive index range of the optically isotropic layer described below, and the method of adjusting 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, even more preferably Bfny-0.1, even more preferably Bfny-0.08, and 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, even more preferably Bfnx+0.1, even more preferably Bfnx+0.08, and particularly preferably Bfnx, most preferably Bfnx-0.02.
Within the above range, the contrast or sharpness of the image can be maintained, and the phenomenon that the screen becomes whitish when exposed to strong external light can be suppressed.

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

Although the composition of the optically isotropic layer is not particularly limited, 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, PMMA (polymethyl methacrylate) generally has a refractive index of about 1.49. In acrylic pressure-sensitive adhesives, a long-chain or branched alkyl group is often introduced, further lowering the refractive index. In order to increase the refractive index, it is effective to copolymerize an acrylic monomer having an aromatic group or copolymerize styrene.
Introducing a sulfur, bromine, fluorene group or the like into a polymer or resin is also a preferred method for increasing the refractive index. A thioepoxy resin or the like is preferable as the high refractive index resin.

Adding highly refractive fine particles to a polymer or resin is also a suitable method for adjusting the refractive index. The refractive index of the high refractive fine particles is preferably 1.60 to 2.74. Fine particles of TiO ₂ , ZrO ₂ , CeO ₂ , Al ₂ O ₃ , BaTiO ₃ , Nb ₂ O ₅ , SnO ₂ and the like can be used as high refractive particles. The high-refractive fine particles preferably have an average primary particle size of 3 nm to 100 nm as observed by TEM (transmission electron microscope). These high refractive fine particles may be used singly or in combination of two or more.
In the specification, "average primary particle size" or "average particle size of primary particles" refers to a 50% volume cumulative particle size. More specifically, 200 primary particles of the particles are observed under a microscope at an appropriate magnification, the diameter of each is measured, the volume is calculated, and the 50% particle size of the cumulative volume is taken as the average primary particle size. do.

The optically isotropic layer is preferably crosslinked and cured. The curing method is not particularly limited, and radiation curing such as heat curing, ultraviolet rays, and electron beams is preferable. Cross-linking agents for curing include isocyanate compounds, epoxy compounds, carbodiimides, oxazoline compounds, amino resins such as melamine, polyfunctional acrylates, and the like.

The optical isotropic layer is produced by applying a coating agent comprising the above components to the uneven surface of the base film, applying the release film to the uneven surface of the base film, and transferring the optical isotropic layer to the uneven surface of the base film. The optically isotropic layer provided on the film can be laminated by a method such as bonding to the uneven surface of the substrate film. In this case, the coating agent is preferably dissolved or diluted with a solvent so as to have a viscosity that facilitates coating. Moreover, the coating agent may be solventless as long as it is a radiation curing type coating agent such as acrylic.

For example, a radiation-curing type coating agent such as acrylic usually contains a photopolymerizable compound.

Photopolymerizable compounds include photopolymerizable monomers, photopolymerizable oligomers, and photopolymerizable polymers, and these can be appropriately adjusted and used. The photopolymerizable compound is preferably a combination of a photopolymerizable monomer and a photopolymerizable oligomer or photopolymerizable polymer.

Photopolymerizable Monomer Photopolymerizable monomers are those having a weight average molecular weight of less than 1000. As the photopolymerizable monomer, a polyfunctional monomer having two (that is, bifunctional) or more photopolymerizable functional groups is preferable. As used herein, "weight average molecular weight" is a value obtained by dissolving in a solvent such as THF and converting to polystyrene by a conventionally known gel permeation chromatography (GPC) method.

Examples of polyfunctional monomers include tripropylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, 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, isocyanurate tri(meth)acrylate, isocyanurate di(meth)acrylate, polyester tri(meth)acrylate, polyester di( meth)acrylate, bisphenol di(meth)acrylate, diglycerin tetra(meth)acrylate, adamantyl di(meth)acrylate, isobornyl di(meth)acrylate, dicyclopentane di(meth)acrylate, tricyclodecane di(meth)acrylate, Those modified with PO, EO or the like can be mentioned.

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 with high hardness.

Photopolymerizable Oligomer The photopolymerizable oligomer has a weight average molecular weight of 1,000 or more and less than 10,000. As the photopolymerizable oligomer, a bifunctional or higher polyfunctional oligomer is preferred. Polyfunctional oligomers include polyester (meth)acrylate, urethane (meth)acrylate, polyester-urethane (meth)acrylate, polyether (meth)acrylate, polyol (meth)acrylate, melamine (meth)acrylate, and isocyanurate (meth)acrylate. Acrylate, epoxy (meth)acrylate, and the like.

Photopolymerizable Polymer The photopolymerizable polymer has a weight average molecular weight of 10,000 or more, preferably 10,000 or more and 80,000 or less, more preferably 10,000 or more and 40,000 or less. If the weight-average molecular weight exceeds 80,000, the resulting laminated film may have poor appearance due to poor coating suitability due to its high viscosity. As the photopolymerizable polymer, a polyfunctional polymer having two or more functionalities is preferable. Polyfunctional polymers include urethane (meth)acrylate, isocyanurate (meth)acrylate, polyester-urethane (meth)acrylate, epoxy (meth)acrylate and the like.

The coating agent may contain a polymerization initiator, a cross-linking agent catalyst, a polymerization inhibitor, an antioxidant, an ultraviolet absorber, a leveling agent, a surfactant, and the like, in addition to the above components.

Alternatively, the melted optically isotropic layer composition is extruded and laminated on the uneven surface of the base film, or the melted optically isotropic layer composition is extruded between the uneven surface of the base film and another film. A method such as lamination is also preferred.

The optically isotropic layer has a function of reducing irregular reflection on the uneven surface by being provided on the uneven surface, but may also have other functions. The optically isotropic layer may have functions such as a hard coat layer, an antireflection layer, an antiglare layer, and an antistatic layer. Also, the optically isotropic layer may be another film or sheet, a pressure-sensitive adhesive layer or an adhesive layer for bonding to a constituent member of a device.

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, most preferably 4 μm. When the thickness is 0.5 μm or more, the unevenness of the substrate film can be flattened, the haze can be reduced, and the 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, most preferably 10 μm. When the thickness is 30 μm or less, it is suitable for thinning.
The thickness of the optically isotropic layer is the 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, even more preferably 10 nm, and particularly preferably 5 nm, from the viewpoint of suppressing the occurrence of iridescence.

The upper limit of the refractive index difference between the refractive index in the direction of the highest refractive index and the refractive index in the direction of the lowest refractive index of the optically isotropic layer is preferably 0.01, and more It is preferably 0.007, more preferably 0.005, particularly preferably 0.003, most preferably 0.002.

(Laminated film)
The lower limit of the thickness of the laminated film is preferably 12 µm, more preferably 15 µm, even 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 handling in production or subsequent processing is facilitated.
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 the section with a microscope, measuring the thickness at 10 points at equal intervals, and calculating the average value.

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 a decrease in contrast and a screen from becoming whitish when exposed to strong external light.

In the case of the laminate film, only one side of the base film may be uneven, but if the ΔRe of the base film is relatively low or the roughness of the unevenness is relatively small, iridescence cannot be sufficiently eliminated. is preferably provided with an uneven surface and an optically isotropic layer on both sides.

The laminated film of the present invention may have two or more substrate films having an uneven surface (roughened surface), may have two or more optically isotropic layers, and may have an uneven surface (roughened surface). It may have a film or layer other than the substrate film having a flattened surface and the optically isotropic layer.
Examples of lamination include types 1 to 4 below.
(Type 1) Base film (uneven surface)/optical isotropic layer (adhesive or adhesive)/Other film (Type 2) Base film (uneven surface)/optical isotropic layer (adhesive or adhesive) / (Uneven surface) Base film (type 3) Base film (uneven surface) / Optical isotropic layer (adhesive or adhesive) / Other film / Optical isotropic layer (adhesive or adhesive) / (Uneven Surface) Base film (Type 4) Other film/Optical isotropic layer (adhesive or adhesive)/(Uneven surface) Base film (uneven surface)/Optical isotropic layer (adhesive or adhesive)/Other Film When the ΔBfNxy of the base film with 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 the following description of the application of the laminated film of the present invention, etc., the term "laminated film" includes the configurations of types 1 to 4 described above. In the case of types 2 to 4, the slow axes of the two base films are preferably parallel or perpendicular to each other, and preferably parallel from the viewpoint of ease of production. Here, "parallel or perpendicular" is allowed from 0 degree or 90 degrees, preferably ±10 degrees, further ±7 degrees, particularly ±5 degrees.

In addition, when referring to an adhesive or an adhesive layer in the specification, a coating agent for an adhesive is applied to an object and crosslinked or dried, or a substrate-less optical adhesive sheet is transferred. means something

Various functional layers may be provided on the surface of the laminated film in accordance with each application. Various functional layers include a hard coat layer, an antiglare layer, an antireflection layer, a low reflection layer, a conductive layer, an antistatic layer, a colored layer, an ultraviolet absorption 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 oriented, and a liquid crystalline dichroic A liquid crystalline polarizer made of a dye, a wire grid type polarizer, and the like can be mentioned.

In the case of a film-shaped polarizer in which iodine or an organic dichroic dye is adsorbed on uniaxially stretched polyvinyl alcohol (PVA), a polarizing plate can be obtained by laminating a laminated film on at least one side of the polarizer. . Lamination can be performed using a PVA-based adhesive, an ultraviolet curing adhesive, or a pressure-sensitive adhesive. Alternatively, the concave-convex surface of the refractive index anisotropic film provided with concaves and convexes and the polarizer may be bonded together with an adhesive or pressure-sensitive adhesive having properties corresponding to the optically isotropic layer. In this case, the refractive index anisotropic film and the adhesive or pressure-sensitive adhesive become the laminated film having the refractive index anisotropic base film having the uneven surface and the optically isotropic layer in the present invention. The thickness of this type of polarizer is, for example, 5-50 μm, preferably 10-30 μm, more preferably 12-25 μm. The thickness of the adhesive or adhesive is, for example, 1-10 μm, preferably 2-5 μm.

In one embodiment, a polarizer (substrate-laminated stretched polarizer) in which PVA is applied to an unstretched or uniaxially stretched substrate and uniaxially stretched together with the substrate to adsorb iodine or an organic dichroic dye. is preferred. In this case, a polarizing plate can be obtained by bonding a polarizer laminated on a base material and a laminated film together with an adhesive or a pressure-sensitive adhesive, and then peeling off the base film used to prepare the polarizer. . Alternatively, the concave-convex surface of the refractive index anisotropic film provided with concaves and convexes and the polarizer may be bonded together with an adhesive or pressure-sensitive adhesive having properties corresponding to the optically isotropic layer. The thickness of the polarizer is, for example, 1-10 μm, preferably 2-8 μm, more preferably 3-6 μm. The thickness of the adhesive or adhesive is, for example, 1-10 μm, preferably 2-5 μm.

Thus, even a very thin polarizer can be easily handled because of the presence of the releasable supporting substrate, and the thin polarizer can be easily laminated on the polyester substrate film. By using such a thin polarizer, it is possible to further reduce the thickness. Many such polarizers have been introduced, for example, in Japanese Unexamined Patent Publication No. 2001-350021 and Japanese Unexamined Patent Publication No. 2009-93074.

The above polarizer can be obtained, for example, by the following procedure. PVA is applied to a releasable supporting base material of thermoplastic resin which is unstretched or uniaxially stretched in the direction perpendicular to the longitudinal direction, and then PVA is applied to the releasable supporting base material of thermoplastic resin and PVA is laminated. The body is longitudinally stretched 2 to 20 times, preferably 3 to 15 times. 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. Dichroic dyes include, for example, iodine and organic dyes. When iodine is used, an aqueous solution of iodine and potassium iodide is preferred. Then, the substrate is immersed in an aqueous solution of boric acid for treatment, washed with water, and dried. It should be noted that the film may be stretched 1.5 to 3 times as preliminary stretching before adsorption of the dichroic dye. This procedure is an example, and the dichroic dye may be adsorbed before stretching, or the treatment with boric acid may be performed before the dichroic dye is adsorbed. The film may be stretched in a bath containing a dichroic dye or in an aqueous boric acid bath. Also, these steps may be divided into multiple stages and combined.

As the releasable supporting base material of thermoplastic resin, polyester such as polyethylene terephthalate, polyolefin such as polypropylene and polyethylene, polyamide, polyurethane, and the like are used. The releasing force can be adjusted by applying a corona treatment to the releasing support base material of thermoplastic resin, providing a releasing coat or an easy-adhesion coating, or the like.

Liquid crystalline polarizers are made by coating a laminated film with a liquid crystal compound and an organic dichroic dye or a coating liquid containing a liquid crystalline dichroic dye, followed by drying and curing with light or heat. A polarizing plate can be obtained by laminating the polarizer. Examples of the method of orienting the liquid crystalline polarizer include a method of rubbing the surface of the laminated film, and a method of curing while aligning the liquid crystalline polarizer by irradiating polarized ultraviolet rays. In addition, since the substrate surface of the laminated film has a certain degree of orientation control power, it may be possible to orientate the film only by coating. It is also a preferable method to provide an orientation layer on the laminated film before providing the liquid crystalline polarizer. Methods for providing the orientation layer include the following.
A method of applying polyvinyl alcohol and its derivatives, polyimide and its derivatives, acrylic resin, polysiloxane derivative, etc. and rubbing the surface thereof to form an alignment layer (rubbing alignment layer).
・A coating liquid containing a polymer or monomer having a photoreactive group such as a cinnamoyl group and a chalcone group and a solvent is applied to the substrate film, and the alignment layer (photo-alignment layer) is formed by aligning and curing by irradiating polarized ultraviolet rays. and how.
In addition, a refractive index anisotropic substrate film having an uneven surface provided with a rubbed alignment layer having characteristics corresponding to an optical isotropic layer on the uneven surface of the refractive index anisotropic film and an optically isotropic film. A laminated film may be constructed with a rubbing orientation layer having properties.

Next, a coated polarizer obtained by blending a dichroic dye with a liquid crystalline compound will be described in detail. In the invention, the polarizing film may be directly provided on the laminated film as a substrate, or 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. .

(Orientation layer)
The alignment layer can provide a polarizing film with a higher degree of polarization by controlling the alignment direction of the polarizing film. As the alignment layer, any alignment layer may be used as long as it can bring the liquid crystal compound of the polarizing film into a desired alignment state. Methods for imparting an orientation state to the orientation layer include, for example, rubbing the surface, oblique vapor deposition of an inorganic compound, formation of a layer having microgrooves, and the like. Further, a method of forming a photo-alignment layer in which molecules are aligned by irradiating polarized light to produce an alignment function is also preferable. Two examples of preferable rubbing treatment alignment layer and photo alignment layer are described below.

(Rubbing treatment orientation layer)
Polyvinyl alcohol and its derivatives, polyimide and its derivatives, acrylic resins, polysiloxane derivatives and the like are preferably used as polymer materials for the alignment layer formed by rubbing.

First, a rubbing treatment orientation layer coating liquid containing the above polymer material is applied onto a substrate film, and then heat drying or the like is performed to obtain an orientation layer before rubbing treatment. The alignment layer coating solution may contain a cross-linking agent.

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

The concentration of the rubbing treatment alignment layer coating solution can be appropriately adjusted depending on the type of polymer and the thickness of the alignment layer to be produced. A range of 3 to 10% by weight is particularly preferred.

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

The temperature for drying by heating depends on the substrate film, but in the case of PET, it is preferably in the range of 30°C to 170°C, more preferably 50°C to 150°C, and still more preferably 70°C to 130°C. If the drying temperature is low, it may be necessary to take a long drying time, resulting in poor productivity. If the drying temperature is too high, it will affect the orientation of the base film, retardation will decrease, and the heat shrinkage of the base film will increase. There are cases where it becomes The heat drying time may be, for example, 0.5 to 30 minutes, more preferably 1 to 20 minutes, and even more preferably 2 to 10 minutes.

The thickness of the rubbed alignment layer is preferably 0.01 to 10 μm, more preferably 0.05 to 5 μm, especially 0.1 to 1 μm.

The rubbing treatment can generally be carried out by rubbing the surface of the polymer layer with paper or cloth in one direction. In general, the surface of the alignment film is subjected to rubbing treatment using a rubbing roller made of a raised cloth made of fibers such as nylon, polyester, and acrylic.

The angle of the rubbing direction can be adjusted by adjusting the angle between the rubbing roller and the base film, and by adjusting the conveying speed of the base film and the rotational speed of the roller.

It should be noted that it is also possible to impart an alignment layer function to the surface of the base film by directly rubbing the base film, and this case is also included in the technical scope of the present invention.

(Photo-alignment layer)
The photo-alignment layer is an alignment film obtained by coating a substrate film with a coating solution containing a polymer or monomer having a photoreactive group and a solvent, and imparting an alignment control force by irradiating polarized light, preferably polarized ultraviolet light. That's what I mean. A photoreactive group refers to a group capable of aligning a liquid crystal by irradiation with light. Specifically, it causes a photoreaction that is the origin of the liquid crystal alignment ability, such as orientation induction of molecules or isomerization reaction, dimerization reaction, photocrosslinking reaction, or photodecomposition reaction caused by light irradiation. be. Among the photoreactive groups, those that cause a dimerization reaction or a photocrosslinking reaction are preferable from the viewpoint of excellent orientation and maintaining 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 the group consisting of C=C bond, C=N bond, N=N bond and C=O bond. A group having at least one selected from the above is particularly preferred.

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

Among the above, a photoreactive group that can cause a photodimerization reaction is preferable, and a cinnamoyl group and a chalcone group have a relatively small amount of polarized light irradiation required for photoalignment, and photoalignment with excellent thermal stability and temporal stability. It is preferable because a layer is easily obtained. As the polymer having a photoreactive group, a polymer having a cinnamoyl group having a cinnamic acid structure at the end of the polymer side chain is particularly preferred. Examples of the structure of the main chain include polyimide, polyamide, (meth)acryl, polyester and the like.

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

As the solvent for the coating solution for forming the photo-alignment layer, any solvent can be used without limitation as long as it dissolves the polymer and monomer having a photoreactive group. As specific examples, those mentioned in the rubbing treatment orientation layer can be exemplified. It is also preferable to add a photopolymerization initiator, a polymerization inhibitor, and various stabilizers to the coating solution for forming the photo-alignment layer. Further, a monomer having no photoreactive group that can be copolymerized with a polymer or a monomer having a photoreactive group other than the polymer and the monomer having a photoreactive group may be added.

The concentration, coating method, and drying conditions of the coating liquid for forming the photo-alignment layer can also be exemplified by those mentioned for the rubbing treatment alignment layer. The thickness is also the same as the preferred thickness of the rubbing treatment alignment layer.

A photo-alignment layer is obtained by irradiating the photo-alignment layer thus obtained before alignment with polarized light.

Polarized light may be applied to the photo-alignment layer before alignment from the alignment layer surface. When the alignment direction of the photo-alignment film is parallel or perpendicular to the alignment direction of the base film of the laminated film, the light may be irradiated through the laminated film.

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

The polarized light source includes a xenon lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, an ultraviolet light laser such as KrF and ArF, and the like, and a high-pressure mercury lamp, an ultra-high-pressure mercury lamp and a metal halide lamp are preferred.

Polarized light 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-Thompson and Glan-Taylor, and wire grid type polarizers. Preferably, the polarized light is substantially parallel light.

By adjusting the angle of the irradiated polarized light, the direction of the alignment regulating force of the photo-alignment layer can be arbitrarily adjusted.

The irradiation intensity varies depending on the type and amount of polymerization initiator and resin (monomer), but is preferably 10 to 10,000 mJ/cm ² , more preferably 20 to 5,000 mJ/cm ² at 365 nm.

(polarizing film)
The polarizing film functions as a polarizer that transmits polarized light in only one direction, and contains a dichroic dye.

(Dichroic dye)
A dichroic dye is a dye that has different absorbances in the long-axis direction and the short-axis direction of the molecule.

The dichroic dye preferably has an absorption maximum wavelength (λMAX) in the range of 300-700 nm. Such dichroic dyes include, for example, acridine dyes, oxazine dyes, cyanine dyes, naphthalene dyes, azo dyes and anthraquinone dyes, with azo dyes being preferred. The azo dyes include monoazo dyes, bisazo dyes, trisazo dyes, tetrakisazo dyes and stilbenazo dyes, preferably bisazo dyes and trisazo dyes. The dichroic dyes may be used alone or in combination, but it is preferable to combine two or more of them in order to adjust the color tone (achromatic color). In particular, it is preferable to combine three or more kinds. In particular, it is preferable to combine three or more kinds of azo compounds.

Preferred azo compounds include 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 into the side chain of a polymer such as acryl. Examples of these dichroic dye polymers include polymers mentioned 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 improving the orientation of the dichroic dye. , more preferably 1.0 to 15% by mass, particularly preferably 2.0 to 10% by mass.

The polarizing film preferably further contains a polymerizable liquid crystal compound in order to improve film strength, degree of polarization, and film homogeneity. Here, the polymerizable liquid crystal compound includes a polymerized liquid crystal compound as a film.

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

The polymerizable liquid crystal compound is preferably a smectic liquid crystal compound, and more preferably a high-order smectic liquid crystal compound, in that higher polarizing properties can be obtained. When the liquid crystal phase formed by the polymerizable liquid crystal compound is a high-order smectic phase, a polarizing film with a higher degree of orientational order can be produced.

Specific preferred polymerizable liquid crystal compounds, for example, JP-A-2002-308832, JP-A-2007-16207, JP-A-2015-163596, JP-A-2007-510946, JP-A-2013-114131 Publication, WO2005/045485, Lub et al. Recl. Trav. Chim. 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 70 to 99.5% by mass in the polarizing film from the viewpoint of increasing the orientation of the polymerizable liquid crystal compound. It is preferably 80 to 97% by mass, particularly preferably 83 to 95% by mass.

The polarizing film can be provided by applying 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 cross-linking agent, and the like.

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

The polymerization initiator is not limited as long as it polymerizes the polymerizable liquid crystal compound, but is preferably a photopolymerization initiator that generates active radicals upon exposure to light. Examples of polymerization initiators include benzoin compounds, benzophenone compounds, alkylphenone compounds, acylphosphine oxide compounds, triazine compounds, iodonium salts and sulfonium salts.

The sensitizer is preferably a photosensitizer such as a xanthone compound, anthracene compound, phenothiazine, rubrene and the like.

Polymerization inhibitors include hydroquinones, catechols, and thiophenols.

As the polymerizable non-liquid crystal compound, one that is copolymerized with the polymerizable liquid crystal compound is preferable. (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, 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 cross-linking agent include compounds capable of reacting with functional groups of polymerizable liquid crystal compounds and polymerizable non-liquid crystal compounds, such as isocyanate compounds, melamine, epoxy resins, and oxazoline compounds.

A polarizing film is provided by directly applying a polarizing film composition coating onto a substrate film or an alignment layer, and then drying, heating, and curing as necessary.

As a coating method, a coating method such as a gravure coating method, a die coating method, a bar coating method and an applicator method, or a known method such as a printing method such as a flexographic method is employed.

For drying, the base film after coating is led to a warm air dryer, an infrared dryer, or the like, and dried at 30 to 170°C, more preferably 50 to 150°C, more preferably 70 to 130°C. The drying time is preferably 0.5 to 30 minutes, more preferably 1 to 20 minutes, even more preferably 2 to 10 minutes.

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 within a temperature range in which the polymerizable liquid crystal compound forms a liquid crystal phase.

When the polarizing film composition coating contains a polymerizable liquid crystal compound, it is preferably cured. Curing methods include heating and light irradiation, and light irradiation is preferred. Curing can fix the dichroic dye 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 curing may be performed by light irradiation at a temperature exhibiting a liquid crystal phase.
Light for light irradiation includes visible light, ultraviolet light, and laser light. Ultraviolet light is preferred because it is easy to handle.

The irradiation intensity varies depending on the type and amount of the polymerization initiator and resin (monomer), but is preferably 100 to 10000 mJ/cm2, more preferably 200 to 5000 mJ/cm2, based on 365 nm.

By applying the polarizing film composition paint on the alignment layer, the polarizing film orients the dye along the alignment direction of the alignment layer, and as a result, has a polarization transmission axis in a predetermined direction. When the composition is applied directly to the substrate without providing the polarizing film, the polarizing film can be oriented by curing the polarizing film-forming composition by irradiating it with polarized light.

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

(Lamination of polarizer and base film)
In addition to the method of directly providing an alignment layer or a polarizing layer on a base film and laminating them, it is also preferable to provide a polarizing layer on another release film according to the above method and transfer this to the base film. The method. Preferred examples of the release film include the release support substrate laminated with the release support substrate described above and the release support substrate used in the laminated polarizer, such as polyester film and polypropylene film. , as a particularly preferred release film. The release film may be subjected to corona treatment, or provided with a release coat or an easy-adhesion coat to adjust the release force.

The method of transferring the polarizing layer to the substrate film is also the same as the above-described method for the releasing supporting substrate-laminated polarizer laminated with the releasing supporting substrate.

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

In the case of a wire grid system, fine conductive wires may be provided on the laminated film of the present invention. When fine grooves are required to provide fine conductive wires, a separate layer for providing the grooves may be provided, or the layer for providing the grooves may be the optically isotropic layer of the present invention.

The angle formed by the transmission axis of the polarizer and the slow axis of the laminated film is not particularly limited, but when the laminated film is used as a polarizer protective film for a polarizing plate for linearly polarizing normal transmitted light. are preferably parallel or perpendicular. "Parallel or perpendicular" is allowed from 0 or 90 degrees, preferably ±10 degrees, further ±7 degrees, especially ±5 degrees.

Further, when the laminated film is used as a polarizer protective film for a polarizing plate that emits depolarized light, such as 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 by the two 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.

The surface of the laminated film of the present invention on which the polarizer is laminated may be either the substrate film surface or the optically isotropic layer surface.

Among these, polarizers that are uniaxially stretched together with a substrate to adsorb iodine and organic dichroic dyes (stretched substrate laminated polarizers) and liquid phase compounds are used in terms of making the polarizing plate thinner. Polarizers are preferred.

(retardation layer)
A retardation layer is preferably provided on the opposite side of the polarizer to the laminated film. The retardation layer is preferably made of a liquid crystal compound because it can be made thinner. As the liquid crystal compound, a raw or negative A plate, a positive or negative C plate, an O plate, or a rod-shaped liquid crystal compound or a discotic liquid crystal compound can be used according to the purpose.

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 when used as optical compensation for a liquid crystal display device. 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 A plate using a rod-like liquid crystal compound or discotic liquid crystal compound is preferably used. In the case of a λ/4 retardation layer and a λ/2 retardation layer of a circularly polarizing plate, an A plate is preferably used using a rod-like compound. These retardation layers may be used not only as a single layer, but also as a combination of a plurality of layers.

As the liquid crystal compound used in 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 A rod-like liquid crystal compound having a polymerizable group described in JP-A-11-513360 can be mentioned.
As a specific compound,
_CH2 =CHCOO-( _CH2 )mO- _Ph1 -COO- _Ph2 -OCO-Ph1 _- O-( _CH2 )n-OCO-CH= _CH2
CH2 =CHCOO-( _CH2 )mO- _Ph1 -COO-NPh-OCO-Ph1 _- O-( _CH2 )n-OCO-CH= _CH2
CH2 =CHCOO-( _CH2 ) _mOP1h -COO- _{Ph2- OCH3
CH2} =CHCOO-( _CH2 )mO- _{Ph1 -} COO-Ph-Ph- _CH2CH ( _CH3 ) _C2H5
m and n are positive numbers from 2 to 6
Ph ₁ , Ph ₂ : 1,4-phenyl group (Ph ₂ may be a methyl group at the 2-position)
NPh: includes 2,6-naphthyl groups.
These are commercially available as LC242 from BASF and can be used.

A plurality of these rod-like liquid crystal compounds may be used in combination at any ratio.

Discotic liquid crystal compounds include benzene derivatives, truxene derivatives, cyclohexane derivatives, azacrown-based macrocycles, and phenylacetylene-based macrocycles. is preferably used. Among them, as the discotic compound, a compound having a triphenylene ring represented by the following general formula is preferably used.

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 are each independently hydrogen, halogen, alkyl group, —O—X; X is alkyl group, acyl group, alkoxybenzyl group, epoxy-modified alkoxybenzyl group, acryloyloxy-modified alkoxybenzyl group, acryloyloxy It is a modified alkyl group or a group represented by the following formula.

（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 applying a composition paint for retardation layer. The composition paint 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 cross-linking agent, and the like. As these materials, the materials described in the alignment layer and the liquid crystal polarizer can be used.

A polarizing film is provided by directly coating the retardation layer composition paint on a polarizer (on a substrate film in the case of a transfer type) or an alignment layer, followed by drying, heating and curing. As for these conditions, the conditions explained in the sections of the alignment layer and the liquid crystal polarizer are preferably used.

Lamination of the retardation layer on the polarizer surface may be provided by applying a liquid crystal compound or an alignment layer to the polarizer, but a retardation layer is provided on another release film according to the above method, Transferring this onto a polarizer is also a preferred method. In the case of multiple retardation layers, it is not necessary to apply all the retardation layers by transfer. The first layer on the polarizer is applied by coating, and the second layer is applied by transfer. can be The first layer and the second layer may be transferred separately, and the first layer and the second layer are laminated on the release film (release substrate / second layer / first layer) and transferred. You can

A protective layer may be provided between the polarizer and the retardation layer. By providing a protective layer, the polarizer is disturbed by the solvent used when providing the retardation layer, the solvent of the adhesive or adhesive used for transfer, and the effects of additives in the retardation layer, adhesive layer, and adhesive on the polarizer. can be prevented. 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 when applying the upper layer, the influence of the solvent when applying the adhesive or adhesive to the retardation layer surface and bonding it to other members, or the influence of the adhesive or the adhesive. .

Examples of the protective layer include a coating layer of transparent resin. As the transparent resin, polyvinyl alcohol, ethylene vinyl alcohol copolymer, polyester, polyurethane, polyamide, polystyrene, acrylic resin, epoxy resin and the like are not particularly limited. A cross-linking agent may be added to these resins to form a cross-linked structure. Moreover, what hardened the photocurable compositions, such as acryl, may be used.

(Liquid crystal display device)
These polarizing plates can be used on either side of the liquid crystal display device as the light source side polarizing plate, the viewing side polarizing plate, or both. A polarizing plate is used by bonding it to a liquid crystal cell with the laminated film facing outward. For bonding, an optical pressure-sensitive adhesive that does not require a substrate is preferable.

Backlights for liquid crystal displays include blue light emitting diodes and yellow phosphor light sources, blue, green and red light emitting diode light sources, blue light emitting diodes, green phosphors, and red phosphor light sources, wavelength conversion light sources using quantum dots, and semiconductors. A laser light source, a cold cathode tube, or the like can be used without particular limitation.

In the polarizing plate having the retardation layer of the present invention, even in a liquid crystal display device having a light source having a sharp peak, rainbow spots are reduced to a level that cannot be recognized, and the half width of the emission peak of each color is narrow. A combination is the more preferred form. As for the half width of the light source, the peak with the narrowest half width is preferably 25 nm or less, more preferably 20 nm or less, even more preferably 15 nm or less, and particularly preferably 10 nm or less. The lower limit of the half-value width is 0.5 nm in terms of a realistic value and the resolution of the measuring instrument. Specifically, suitable light sources include a QD light source and a light source using a KSF phosphor for the red region, and one suitable light source is a light source using a KSF phosphor.

When the polarizing plate having a retardation layer of the present invention is used in accordance with recent thinning, the thickness of the polarizing plate having a retardation layer is preferably 20 to 80 μm, more preferably 25 to 70 μm, and still more preferably. 28 to 60 μm. (The thickness of the polarizing plate having a retardation layer here means the thickness from the retardation layer to the laminated film, and the surface coating layer such as the antireflection layer of the laminated film and the protective coat on the retardation layer Layers are included, but adhesive layers and adhesive layers for laminating the polarizing plate with other members are not included.In the case of such a thin display, a blue light emitting diode and a yellow phosphor light source, 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 an antireflection circularly polarizing plate for EL display devices and the like. In order to obtain a circularly polarizing plate, the retardation layer is preferably a quarter-wave layer. The front retardation of the quarter-wave layer is preferably 100-180 nm, more preferably 120-150 nm.

In addition, the 1/4 wavelength layer alone does not provide a 1/4 wavelength in a wide wavelength range of visible light, which may cause coloring. In such a case, an additional 1/2 wavelength layer may be provided. In this case, it is preferable to provide a half-wave layer between the polarizer and the quarter-wave layer. The front retardation of the half-wave layer is preferably 200-360 nm, more preferably 240-300 nm.

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

When a quarter-wave layer and a half-wave layer are used in combination as a circularly polarizing plate, the angle (θ) between the orientation axis (slow axis) of the half-wave 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-wave layer and the orientation axis (slow axis) of the quarter-wave layer is preferably in the range of 2θ+45°±10°, more preferably 2θ+45°±5°. and more preferably 2θ+45°±3°. These angles can be controlled by the rubbing angle and the irradiation angle of polarized ultraviolet rays.

Furthermore, it is also a preferred form to provide a C plate layer on the quarter wavelength layer in order to reduce changes in coloring when viewed obliquely. A positive or negative C plate layer is used according to the characteristics of a quarter wavelength layer or a half wavelength layer.

As a lamination method of these retardation layers, in the case of a 1/2 wavelength layer and a 1/4 wavelength layer, for example, the following can be mentioned.
- A 1/2 wavelength layer is provided on the polarizer by transfer, and a 1/4 wavelength layer is provided thereon by transfer.
- A 1/4 wavelength layer and a 1/2 wavelength layer are provided in this order on a release film and transferred onto a polarizer.
• A half-wave layer is provided on the polarizer by coating, and a quarter-wave layer is provided by transfer.
• A 1/2 wavelength layer is provided on the polarizer by coating, and a 1/4 wavelength layer is further provided by coating.
Various methods such as can be adopted.

Also, when laminating a C plate, a method of applying or transferring a C plate layer on a quarter wavelength layer provided on a polarizer, a method of transferring or bonding a quarter wavelength layer, a quarter wavelength Various methods such as a method of preliminarily laminating layers can be employed.

The thickness of the circularly polarizing plate thus obtained is preferably 100 μm or less. Furthermore, it 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 described more specifically with reference to examples. The present invention is not limited to the following examples, and it is possible to carry out the present invention with appropriate modifications within the scope of the gist of the present invention. All of them are included in the technical scope of the present invention.
Methods for evaluating physical properties in Examples are as follows.

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

(2) Thickness d of raw film
Using an electric micrometer (Millitron 1245D manufactured by Fineruff Co.), the thickness was measured at five points, and the average value was obtained.

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

(4) Nz Coefficient A value obtained by |Bfnx−Bfnz|/|Bfnx−Bfny| was used as the Nz coefficient.

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

(6) Retardation in thickness direction (Rth)
The retardation in the thickness direction is obtained by multiplying the two birefringences ΔBfNxz (=|Bfnx−Bfnz|) and ΔBfNyz (=|Bfny−Bfnz|) when viewed from the cross section in the thickness direction of the film by the film thickness d. is a parameter that indicates the average retardation obtained by Bfnx, Bfny, Bfnz and the film thickness d (nm) are obtained in the same manner as described above, and the average value of (ΔBfNxz×d) and (ΔBfNyz×d) is calculated to calculate the thickness direction retardation (Rth). Calculated: Rth=(ΔBfNxz×d+ΔBfNyz×d)/2.

(7) Surface roughness (Ra, Rq, Rz, Ry, Rp, Rv, Sm)
Each parameter of the surface roughness is obtained from a roughness curve measured using a contact roughness meter (Mitutoyo, SJ-410, detector: 178-396-2, stylus: standard stylus 122AC731 (2 μm)). asked. The settings are as follows.
Curve: R
Filter: GAUSS
λc: 0.8mm
λs: 2.5 µm
Measuring length: 5mm
Measurement speed: 0.5mm/s
Rq was determined according to JIS B0601-2001, and others were determined according to JIS B0601-1994.

(8) Thickness of optically isotropic layer The thickness of the roughened base film and laminated film was determined by embedding each film in epoxy resin, cutting out a section of the cross section, and observing it under a microscope. The thickness was measured and taken as the average value. A polarizing microscope was used when the interface was difficult to see. In addition, 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 an optically anisotropic layer on a release film on an uneven surface, the refractive index of a sample peeled off from the release film was measured so as to have a thickness of about 20 μm. It was measured in the same manner as the base film. It was confirmed that nx, ny, and nz are the same value.

(Production of easy-adhesion layer component)
(Polymerization of polyester resin)
194.2 parts by weight of dimethyl terephthalate, 184.5 parts by weight of dimethyl isophthalate, and 14.8 parts by weight of dimethyl-5-sodium sulfoisophthalate were added to a stainless steel autoclave equipped with an agitator, thermometer, and partial reflux condenser. , 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 carried out at a temperature of 160° C. to 220° C. over 4 hours. Then, the temperature was raised to 255° C., and the pressure in the reaction system was gradually reduced, followed by reaction under a reduced pressure of 30 Pa for 1 hour and 30 minutes to obtain a copolymerized polyester resin. The resulting copolymerized polyester resin was pale yellow and transparent. When the reduced viscosity of the copolymerized polyester resin was measured, it was 0.70 dl/g. The glass transition temperature by DSC was 40°C.

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

(Polymerization of block polyisocyanate-based cross-linking agent used in easy-adhesion layer)
A flask equipped with a stirrer, a thermometer, and a reflux condenser was charged with 100 parts by mass of a polyisocyanate compound having an isocyanurate structure made from hexamethylene diisocyanate (Duranate TPA, manufactured by Asahi Kasei Chemicals) and 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 held at 70° C. for 4 hours in a nitrogen atmosphere. After that, the temperature of the reaction solution was lowered to 50° C., and 47 parts by mass of methyl ethyl ketoxime was added dropwise. By measuring the infrared spectrum of the reaction solution, it was confirmed that the absorption of isocyanate groups had disappeared, and an aqueous blocked polyisocyanate dispersion having a solid content of 75% by mass was obtained.

(Adjustment of coating liquid for easy adhesion layer)
A P1 coating solution was prepared by mixing the following coating agents.
Water 50.00% by mass
Isopropanol 33.00% by mass
Polyester water dispersion 12.00% by mass
Block isocyanate-based cross-linking agent 0.80% by mass
Particles 1.40% by mass
(Silica sol with an average particle size of 100 nm, solid content concentration of 40% by mass)
Catalyst (organotin compound solid content concentration 14% by mass) 0.30% by mass
Surfactant 0.50% by mass
(Silicone type, solid content concentration 10% by mass)

(Manufacture of polyester resin for film)
(Production Example 1-Polyester X)
When the temperature of the esterification reactor reaches 200° C., 86.4 parts by mass of terephthalic acid and 64.6 parts by mass of ethylene glycol are charged, and 0.017 parts by mass of antimony trioxide as a catalyst is added while stirring. , 0.064 parts by mass of magnesium acetate tetrahydrate, and 0.16 parts by mass of triethylamine were charged. Then, the pressure was increased and the temperature was increased, and the pressure esterification reaction was performed under the conditions of gauge pressure 0.34 MPa and 240° C., then the pressure in the esterification reactor 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. After 15 minutes, dispersion treatment was performed with a high-pressure disperser. After 15 minutes, the obtained esterification reaction product was transferred to a polycondensation reactor, and polycondensation reaction was performed at 280°C under reduced pressure.

After the polycondensation reaction is completed, filtration is performed with a NASLON (registered trademark) filter having a 95% cut diameter of 5 μm, extruded from the nozzle in strand form, and cooling water that has been pre-filtered (pore size: 1 μm or less) is filtered. It was cooled, solidified and cut into pellets. The resulting polyethylene terephthalate resin (X) had an intrinsic viscosity of 0.62 dl/g and contained substantially no inert particles or internal precipitated particles. (Hereinafter abbreviated as PET (X).)

(Production of raw films A and B)
PET (X) resin pellets containing no particles as a raw material for film are supplied to an extruder, extruded in a sheet form from a nozzle, and then wound around a casting drum with a surface temperature of 30 ° C. using an electrostatic casting method. It was cooled and solidified to produce an unstretched film. Next, the P1 coating liquid was applied to both sides of this unstretched PET film by a reverse roll method so that the coating amount after drying was 0.12 g / m ² , and then led to a dryer and dried at 80 ° C. for 20 seconds. bottom.

The unstretched film with the coating layer formed thereon was guided to a tenter stretching machine, and while holding the ends of the film with clips, 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, it was treated at a temperature of 225 ° C. for 30 seconds, and then cut at both ends of the film cooled to 130 ° C. with a shear blade, and a tension of 0.5 kg / mm ² After cutting off the selvages, the film was wound up to obtain a raw film A having a film thickness of 80 μm.

A raw film B having a different film thickness was obtained in the same manner as the raw film A except that the thickness of the unstretched film was changed by increasing the line speed after casting.

(Manufacturing raw film C)
An unstretched film (coated with an easy-adhesion layer) produced 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 with a peripheral speed difference. After being stretched 2.0 times in the running direction in the same manner as the raw film A, it was led to a hot air zone at a temperature of 135° C. and stretched 4.0 times in the width direction to obtain a raw film C.

(Original film D)
An unstretched film (coated with an easy-adhesion layer) produced 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 with a peripheral speed difference. After the film was stretched 3.5 times in the running direction, it was led to a hot air zone at a temperature of 135° C. and stretched 3.5 times in the width direction by the same method as for raw film A, to obtain raw film D.

(Production of surface-roughened film)
Attach urethane foam to a glass plate, and then attach the periphery of the original film A with double-sided tape. 45 degrees and 135 degrees) to obtain a surface-roughened film A1.
The periphery of raw film A was attached to a glass plate with double-sided tape, set in a dry sandblaster, and treated by spraying an abrasive (sandblasting) to obtain surface-roughened film A2.
A masking film made of polypropylene film is attached to one side of the original film A, which is immersed in a 38% potassium hydroxide aqueous solution (95 ° C.) (chemical etching), washed with water, and then the masking film is peeled off and dried. A surface-roughened film A4 was obtained.
Various surface-roughened films shown in Table 2 were obtained from raw films A, B, C, and D by changing the belt sander conditions (sanding belt type, etc.) and sandblasting conditions (abrasive particle size, etc.). rice field.
A #320 sanding belt was used to manufacture B1 and C1, and a #180 sanding belt was used to manufacture A3 and D1. Abrasives of the sand blaster were used in the order of A5, A6, B2 and A2.
In addition, in order to eliminate the influence of local projections, the belt-sanded and sandblasted surfaces were lightly polished with #400 sandpaper.

(Production of laminated films F1 to F17)
(Preparation of coating agent for optically isotropic layer)
As a coating agent for the optically isotropic layer, those shown in Table 3 were prepared.

On the uneven surface of the surface roughened film A1 of 20 cm × 30 cm, the above-mentioned easy adhesion layer diluted 4 times with a solution of water / isopropanol = 2/1 is applied and dried to obtain an easy adhesion of about 30 nm. layer was established. Further, the coating agent a for the optically isotropic layer was applied thereon with an applicator, and then cured from the coated surface with a high-pressure mercury lamp to obtain a laminated film F1.

Laminated films F2 to F16 were obtained in the same manner as in Example 1, except that the type of surface-roughened film and/or coating agent was changed. Note that the laminated film F14 was provided with an optical isotropic layer on both sides.

A solution of Vylon (registered trademark) 200 (RV200) (manufactured by Toyobo Co., Ltd.) in a 20% toluene/methyl ethyl ketone mixed solvent is applied to the uneven surface of the 20 cm × 30 cm roughened film B2, and then dried to form an optically isotropic layer. was established. The optically isotropic layer surfaces of the obtained two optically isotropic layered laminated films are superimposed and passed between rolls heated to 100° C. to bond the two optically isotropic layered laminated films to obtain an optically isotropic layered laminated film. F17 was obtained. In addition, the slow axes of the surface-roughened film B2 were bonded together so that they were parallel to each other. Byron 200 has a refractive index of 1.55.

Table 4 shows the structures and physical properties of the laminated films F1 to F17.

(Evaluation of laminated film)
(Observation of rainbow spots under crossed Nicols)
The laminated film was placed between two polarizing plates arranged in crossed Nicols so that the slow axis of the base film was at 45 degrees with the transmission axis of the polarizing plate on the light source side, and about 60 cm away from the polarizing plate on the viewing side. The state of transmitted light was observed from the front, and the presence or absence of iridescence was evaluated according to the following criteria. A cold cathode tube was used as the light source.
○: No iridescence was observed △: Slight iridescence was observed ×: Iridescence was observed

(whitening)
With the optically isotropic layer of the laminate film facing upward, the laminate was irradiated with a halogen lamp from below, and the degree of whitening of the laminate was evaluated from an obliquely upward direction of 45 degrees according to the following criteria.
A: Almost no whitening was observed.
◯: Slight whitening was observed, but the transparency was high.
Δ: Whitening was observed, and the transparency was slightly inferior.
x: Whitening was observed, and the transparency was also low.
Incidentally, Examples 31 to 36 were evaluated using a polarizing plate. The results of Examples 31-36 are listed in Table 5.

Production of polarizer A (single-layer polarizer) A polyvinyl alcohol resin film having a degree of saponification of 99.9% was led to rolls with different peripheral speeds and uniaxially stretched 3 times at 100°C. The obtained stretched polyvinyl alcohol stretched film was dyed in a mixed aqueous solution of potassium iodide (0.3%) and iodine (0.05%), and then dyed in a 10% aqueous solution of boric acid at 72° C. to 1.8%. It was uniaxially stretched twice. Thereafter, the film was washed with ion-exchanged water, immersed in a 6% potassium iodide aqueous solution, and dried at 45° C. to obtain a polarizer after removing the aqueous solution with an air knife. The thickness of the polarizer was 18 μm.

Production of polarizer B (substrate-laminated polarizer) An unstretched film having a thickness of 100 μm was prepared using polyester X as a thermoplastic resin substrate, and a degree of polymerization of 2400 and a degree of saponification of 99 were applied to one side of the unstretched film. A PVA layer was formed by applying and drying an aqueous solution of .9 mol % polyvinyl alcohol. The resulting laminate was stretched twice in the longitudinal direction between rolls having different peripheral speeds at 120° C. and wound up. Next, the obtained laminate was treated with a 4% boric acid aqueous solution for 30 seconds, and then immersed in a mixed aqueous solution of iodine (0.2%) and potassium iodide (1%) for 60 seconds for dyeing. , followed by treatment with a mixed aqueous solution of potassium iodide (3%) and boric acid (3%) for 30 seconds. Furthermore, this laminate was uniaxially stretched in the longitudinal direction in a mixed aqueous solution of boric acid (4%) and potassium iodide (5%) at 72° C., washed with a 4% potassium iodide aqueous solution, and the aqueous solution was removed with an air knife. After the removal, the film was dried in an oven at 80° C., both ends were slit and wound up to obtain a substrate-laminated 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. The thickness was read by embedding the base-material-laminated polarizer in an epoxy resin, cutting out a slice, and observing it with an optical microscope.

Method for manufacturing polarizer C (liquid crystal compound polarizer (rubbing treatment)) (formation of rubbing alignment layer)
A rubbing alignment layer paint having 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 raised cloth. The alignment control direction was adjusted by the rubbing direction.

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

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

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

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

A dye (e) of the following formula was synthesized with reference to the method for producing the compound of general formula (1) in JP-B-63-1357.

(Formation of polarizing film)
Compound (a) 75 parts by mass, compound (b) 25 parts by mass, dye (c) 2.5 parts by mass, dye (d) 2.5 parts by mass, dye (e) 2.5 parts by mass, IRGACURE (R) A polarizing film paint consisting of 6 parts by mass of 369E (manufactured by BASF) 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 film with a thickness of 2 μm. Subsequently, UV light was applied, and a polarizer made of a liquid crystal compound was provided.

Method for manufacturing polarizer D (liquid crystal compound polarizer (photo-alignment)) (synthesis of paint for photo-alignment layer)
Based on the descriptions of Examples 1, 2, and 3 of JP-A-2013-33248, a 5% by mass cyclopentanone solution of 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。

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

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

Production of λ/4 and λ/2 Composite Retardation Layer Transfer Film A biaxially oriented polyethylene terephthalate (PET) film having a thickness of 50 μm was rubbed as a substrate. A retardation layer-forming solution was applied to the rubbed surface by a bar coating method, dried, oriented, and cured by irradiation with ultraviolet rays to provide a quarter-wave layer on the biaxially stretched polyethylene terephthalate film. Furthermore, polyvinyl alcohol (polyvinyl alcohol 1000 completely saponified type 2 mass% aqueous solution (surfactant 0.2%) was applied on the quarter-wave layer and dried to obtain a polyvinyl alcohol film with a thickness of about 100 nm. Subsequently, the surface of the polyvinyl alcohol film was subjected to rubbing treatment, and the rubbing-treated surface of PVA was coated with a solution for forming a retardation layer by a bar coating method, dried, and after orientation treatment, was cured by irradiating with ultraviolet rays. A 1/2 wavelength layer was provided, and the angle between the rubbing direction when providing the 1/4 wavelength layer and the rubbing direction when providing the 1/2 wavelength layer was 60 degrees.

Retardation layer forming solution LC242 (manufactured by BASF) 75 parts by mass The following compound 20 parts by mass

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 mass Irgacure 379 3 parts by mass Surfactant 0.1 parts by mass Methyl ethyl ketone 250 parts by mass

Manufacture of λ/4 retardation layer transfer film Polyvinyl alcohol (polyvinyl alcohol 1000 completely saponified 2% by mass aqueous solution (surfactant 0.2%) is applied to a 50 μm thick biaxially stretched polyethylene terephthalate (PET) film, and dried. A polyvinyl alcohol film having a thickness of about 100 nm was obtained, and then the surface of the polyvinyl alcohol film was subjected to a rubbing treatment. After drying and orientation treatment, it was cured by irradiating with ultraviolet rays to form a λ/4 wavelength layer.

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

Examples 1-26, Comparative Examples 1-6
A commercially available UV-curable acrylic adhesive was applied to the substrate film surface or the optically isotropic layer surface of the laminated films F1 to F17 using an applicator. The polarizer surface of the polarizer B (substrate-laminated polarizer) was adhered to the coated surface, and the laminated film surface was irradiated with a high-pressure mercury lamp for curing. 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 made parallel. A commercially available optical 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 adhesive surface, and the PET film as the base material is peeled off. to obtain a polarizing plate having a retardation layer. The bonding was performed so that the absorption axis of the polarizer, the alignment direction of the half-wave layer (the rubbing direction is 15 degrees) and the alignment direction of the quarter-wave layer (the rubbing direction) are 75 degrees.

Examples 27-30
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 an uneven surface so that the thickness after drying is 5 μm, and the solvent is removed by heating. The polarizer surface of the polarizer) was bonded together, and the laminated film surface was irradiated with a high-pressure mercury lamp 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.

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 0.5 parts by mass as a polymerization initiator. 25 parts by mass of azobisisobutyronitrile was reacted in ethyl acetate to obtain an ethyl acetate solution of a copolymer (Mw=400,000) (solid concentration: 30% by mass).

Examples 32-34
Coating agents b, e, and f for the optical isotropic layer were applied to the uneven surface of the film A1 having the uneven surface so as to have a thickness of 5 μm, and the polarizer of the polarizer B (substrate laminated polarizer) was applied to the coated surface. The surfaces of the laminated film were laminated together and cured by irradiating a high-pressure mercury lamp from the laminated film surface. 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, 36
The same procedures as in Examples 31 and 33 were performed except that B1 was used as the film having an uneven surface.

Example 37
A commercially available UV-curable acrylic adhesive was applied to the optically isotropic layer surface of the laminated film F5 using an applicator. The polarizer surface of the polarizer E (transfer type liquid crystal compound polarizer) was adhered to the coated surface, and the laminated film surface was irradiated with a high-pressure mercury lamp to cure. After that, 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 made parallel. A commercially available optical pressure-sensitive adhesive sheet was adhered to the polarizer surface, the retardation surface of the transfer type λ/4 retardation layer transfer film was adhered to the optical pressure-sensitive adhesive surface, and the PET film as the substrate was peeled off. The bonding was performed so that the absorption axis of the polarizer and the alignment direction (rubbing direction) of the quarter-wave layer were at 45 degrees.

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

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

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

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

Example 44
A polarizer C (liquid crystal compound polarizer (rubbing treatment)) was provided on the base film surface of the laminate film F6 so that the slow axis of the base film and the light transmission axis of the polarizer were at 45 degrees. Further, 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, and high refractive index layer (composition for low refractive index layer)
Peltron (TM) A-2508LR (manufactured by Pernox Co., Ltd., hollow silica-containing type, refractive index 1.33 (Abbe method))
(Composition for high refractive layer)
Peltron (TM) A-2300 (manufactured by Pelnox Co., Ltd., refractive index 1.65 (Abbe method))
(Composition for hard coat)
Peltron (TM) A-2005 (manufactured by Pelnox Co., Ltd.)

After coating the above composition on the target film with a bar coater, it was dried at 80° C. to remove the solvent, and further cured by irradiation with ultraviolet light from a high-pressure mercury lamp. In these compositions, Irgacure 184 (3% by weight, based on solid content) was used as a photopolymerization initiator. When thinning the film thickness, it was adjusted by diluting with methyl isobutyl ketone.

Example 45
A low refractive index layer (thickness: 3 μm) was provided on the base film surface of the laminated film F5. Other than this, the procedure was the same as in Example 5.

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

Example 47
The procedure of Example 19 was repeated 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
The same procedure as in Example 45 was repeated except that polarizer A (single-layer polarizer) was used as the polarizer.

The circularly polarizing plate of a portable terminal using a commercially available organic EL was peeled off, and instead the circularly polarizing plate obtained above was placed for evaluation. The direction of the transmission axis of the polarizer of the circularly polarizing plate was set to be the same as the direction of the transmission axis of the original circularly polarizing plate. For the evaluation, confirmation of the iridescence and contrast of the image were observed.

(Evaluation of circularly polarizing plate)
The circularly polarizing plate of a portable terminal using a commercially available organic EL was peeled off, and instead the circularly polarizing plate obtained above was placed for evaluation. The direction of the transmission axis of the polarizer of the circularly polarizing plate was set to be the same as the direction of the transmission axis of the original circularly polarizing plate. For the evaluation, confirmation of the iridescence and contrast of the image were observed.

(Observation of rainbow spots)
The display was set to solid white, and the presence or absence of iridescence was confirmed by viewing from the front and oblique directions.
○: No iridescence was observed △: Slight iridescence was observed ×: Iridescence was observed

(observation of contrast)
The image of the scenery was displayed on the display, and the contrast from the front was observed by illuminating the light from the fluorescent lamp on the table from above.
⊚: Vivid contrast remained.
Good: A slight reduction in contrast was observed due to scattered light.
Δ: A decrease in contrast was observed, but the image could be observed.
×: Image became difficult to see due to scattered light

(Anti-reflection effect)
◯: Brightness of the drive wiring was observed.
x: The brilliance of the metal wiring was not conspicuous.

(depolarization)
Polarized sunglasses were worn, and observation was made at an angle in which the transmission axis of the polarizer was horizontal.
A: There was no blackout.
×: Blacked out and the screen became invisible.

Table 5 shows the configuration and evaluation results of each example.

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*: optically isotropic layer coating agent 5*: optically isotropic layer refractive index 6*: polarizer laminated surface 7*: Whitening evaluation 8*: Polarizer 9*: Angle between the transmission axis of the polarizer and the slow axis of the base film 10*: Retardation layer 11*: Image contrast 12*: Rainbow spot evaluation 13*: Antireflection effect 14 *: depolarization

The polarizing plate of the present invention can suppress iridescence and ensure high transparency and vivid image display when used in an environment of a light source having a steep peak.

Claims (7)

A polarizing plate having, in this order, a laminated film having a substrate film and an optically isotropic layer, a polarizer, and a retardation layer made of a liquid crystal compound, which has the following characteristics (a) to ( h ).
(a) At least one surface of the substrate film is uneven, and the arithmetic mean roughness (Ra) of the uneven surface is 0.4 to 4 μm.
(b) The refractive index anisotropy (ΔBfNxy) of the base film is 0.07 to 0.2.
(c) An optically isotropic layer is provided on the uneven surface of the base film, and the refractive index of the optically isotropic layer is from Bfny−0.15 to Bfnx+0.15 and is 1.57 or more. .
(However, the refractive index in the slow axis direction of the base film is Bfnx, the refractive index in the fast axis direction is Bfny , and ΔBfNxy=Bfnx−Bfny )
(d) The substrate film has a retardation difference (ΔRe) of 90 to 800 nm.
(However, ΔRe=Ra×ΔBfNxy)
(e) The in-plane retardation of the substrate film is 3000 to 30000 nm.
(f) Bfnx of the base film is 1.67 to 1.73.
(g) The base film is a polyester film.
(h) The optically isotropic layer is provided in direct contact with the irregular surface without any other layer interposed therebetween, or is provided only via the easy-adhesion layer. 2. The polarizing plate according to claim 1, wherein the base film has a plane orientation degree (ΔP) of 0.09 to 0.15. 3. The polarizing plate according to claim 1, wherein the optically isotropic layer has a refractive index of Bfny to Bfnx. 4. The polarizing plate according to claim 1, wherein the optically isotropic layer has a refractive index of Bfny+0.02 to Bfnx. A liquid crystal display device comprising the polarizing plate according to any one of claims 1 to 4. An organic EL display device comprising the polarizing plate according to any one of claims 1 to 4. 6. The liquid crystal display device according to claim 5, comprising a QD (quantum dot) light source and/or a light source using a KSF phosphor for the red region.