Polarizing film laminate, optical display panel in which polarizing film laminate is used, polarizing film laminate with transparent adhesive layer, and polarizing film assembly

Abstract

To provide a polarizing film laminate, etc., with which it is possible to suppress effects due to sunlight irradiation and thereby comprehensively solve the problems of polyenization, color loss and thermal reddening.SOLUTION: In an orthogonal coordinate system composed of an x-axis representing the iodine concentration (wt.%) of a polarizing film and a y-axis representing the moisture content (g / m2) of a polarizing film laminate, the x-y coordinate point has an iodine concentration and moisture content included in an area enclosed by a first segment linking a first coordinate point of (6.0, 0.7) and a second coordinate point of (1.8, 4.2), a second segment linking the second coordinate point and a third coordinate point of (1.8, 5.1), a third segment linking the third coordinate point and a fourth coordinate point of (5.7, 2.6), a fourth segment linking the fourth coordinate point and a fifth coordinate point of (7.0, 0.7) and a fifth segment linking the first coordinate point and the fifth coordinate point. The polarizing film laminate is a light absorption layer having light absorption ability, and the light transmissivity of which at wavelength 380 mm is 5% or less.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a polarizing film laminate, an optical display panel in which the polarizing film laminate is used, a polarizing film laminate with a transparent adhesive layer, and a polarizing film assembly. [Background technology]

[0002] In recent years, various possibilities have been found for optical display panels such as liquid crystal panels and organic electroluminescence (EL) panels, in addition to their use in electronic devices such as smartphones and personal computers, and electrical appliances such as IoT home appliances, as well as in motorized vehicles such as automobiles, trains, and airplanes. For example, optical display panels could be mounted on the windshield, dashboard, exterior, and other various parts of the vehicle body to provide various information to the driver and also to transmit various information to the outside.

[0003] In response to such circumstances, there is a demand for further improvement in durability in harsh environments, such as the inside of a motorized vehicle, etc. For example, the performance of optical display panels, particularly polarizing film laminates (polarizing plates) used in optical display panels, and further polarizing films (polarizers) used in polarizing film laminates, may deteriorate due to usage environments such as high temperature or high humidity, or due to exposure to sunlight, and in the worst case, may become unusable.

[0004] Patent Document 1 discloses a polarizer with improved durability in high temperature or high humidity environments, a polarizing plate using this polarizer, and an example of a liquid crystal display device using the polarizing plate. As for durability, the problem here is red loss (polarized loss of long wavelength light) in crossed Nicols that occurs when the film is left under high temperature conditions, and in order to solve this problem, it is proposed to add zinc and adjust the zinc content to a specified range in relation to the iodine content.

[0005] Similarly, Patent Document 2 relates to a polarizing plate used in an in-vehicle image display device with improved durability in high temperature or high humidity environments, and focuses on the moisture content of the polarizing plate and the saturated water absorption of the protective film. In-vehicle polarizing plates are required to have high temperature durability, and in high temperature environments, the transmittance of the polarizing plate may be significantly reduced due to polyenation. In order to solve this problem, Patent Document 2 proposes using a transparent protective film that is bonded to a polarizer and has a saturated water absorption within a predetermined range, and reducing the moisture content of the polarizing plate.

[0006] Patent Document 3 also relates to a polarizing plate with improved durability under high temperature or high humidity conditions, and focuses on the moisture content of the polarizing plate and the moisture permeability of the protective film. In a high temperature environment, the inside of the polarizing plate becomes hot and humid, which results in large changes in light transmittance, polarization degree, image hue, etc., and reduces the reliability of the polarizing plate. Therefore, it is proposed to attach a protective film with low moisture permeability to the polarizer in a state where the moisture content of the polarizer is reduced as much as possible.

[0007] Patent Document 4 also relates to a polarizing plate with improved durability under high temperature or high humidity conditions, or under low temperature conditions, and describes that polarizers can be deteriorated by ultraviolet or infrared rays, and that the visibility of liquid crystal display devices (LCDs) can be deteriorated when used at high temperatures or under high temperature and high humidity conditions. In order to solve these problems, it is proposed to prevent fluctuations in transmittance by incorporating an ultraviolet absorber or an infrared absorber into the protective film of the polarizing film. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2003-29042 A [Patent Document 2] JP 2014-102353 A [Patent Document 3] JP 2002-90546 A [Patent Document 4] JP 2006-184883 A Summary of the Invention [Problem to be solved by the invention]

[0009] With respect to optical display panels, particularly polarizing film laminates used in optical display panels and polarizing films used in polarizing film laminates, problems that are known to occur under high temperature or high humidity environments include "polyenation," "color loss," and "red discoloration upon heating."

[0010] In general, "polyenization" refers to a phenomenon in which the single transmittance of a polarizing film laminate decreases when placed in a high-temperature or high-humidity environment, and "color loss" and "heat reddening" refer to phenomena in which the crossed transmittance decreases when a polarizing film laminate is placed in a crossed Nicol configuration and the crossed transmittance is measured at wavelengths of 410 nm and 700 nm when placed in a high-temperature or high-humidity environment. "Color loss" is a phenomenon in which the transmittance increases, particularly on the long wavelength side of about 700 nm and the short wavelength side of about 410 nm, causing color loss in a black display, while "heat reddening" is a phenomenon in which the transmittance increases, particularly on the long wavelength side of about 700 nm, causing the polarizing film to turn red.

[0011] Patent Document 1 focuses mainly on the problem of "color loss", Patent Document 2 focuses mainly on the problem of "polyenation", and Patent Document 3 focuses mainly on the problem of "reddening by heat", and the solutions proposed in each document are considered to be effective at least for solving each problem. However, the inventions described in each patent document were not necessarily sufficient to comprehensively solve these problems. Based on the fact that "polyenation", "color loss", and "reddening by heat" are all interrelated through iodine and moisture, and further through temperature and humidity that affect moisture, the applicant of the present application has conducted extensive research and found that these problems can be comprehensively solved by adjusting the iodine concentration of the polarizing film and the moisture content of the polarizing film laminate.

[0012] As a result of further intensive research, the applicant has discovered that sunlight, or more precisely, the ultraviolet rays, visible light, and infrared rays contained in sunlight, promote "polyenization," "color loss," and "reddening upon heating," and in particular, promotes "polyenization." The applicant has come to the insight that the problems of "polyenization," "color loss," and "reddening upon heating" can be more effectively and comprehensively solved by adjusting the iodine concentration of the polarizing film and the moisture content of the polarizing film laminate, as well as by suppressing the effects of sunlight.

[0013] The present invention aims to comprehensively solve the three problems of "polyenation," "color loss," and "reddening upon heating" by adjusting the iodine concentration in the polarizing film and the moisture content in the polarizing film laminate, as well as by suppressing the effects of sunlight exposure. [Means for solving the problem]

[0014] In order to solve the above problems, a polarizing film laminate according to one aspect of the present invention is a polarizing film laminate including a polarizing film made of a polyvinyl alcohol-based resin and an optically transparent polarizing film protective film bonded to at least the viewing side surface of the polarizing film directly or via another optical film, and the x-axis represents the iodine concentration (wt.%) of the polarizing film, and the y-axis represents the moisture content (g / m2) of the polarizing film laminate. 2 ) in the xy Cartesian coordinate system, the iodine concentration is 6.0 wt.% and the water content is 0.7 g / m 2 The first coordinate point of the sample, the iodine concentration of 1.8 wt.% and the water content of 4.2 g / m 2 a first line segment connecting the second coordinate point and the second coordinate point; 2 a second line segment connecting the third coordinate point and the third coordinate point; 2 a third line segment connecting the fourth coordinate point and the fourth coordinate point; 2the iodine concentration and the moisture content are included within an area surrounded by a fourth line segment connecting the first coordinate point to the fifth coordinate point, and a fifth line segment connecting the first coordinate point to the fifth coordinate point, and the polarizing film protective film is a light absorbing layer having a light absorbing ability and is characterized in that the light transmittance at a wavelength of 380 nm is 5% or less. The polarizing film laminate of this embodiment can comprehensively solve the problems of "polyenation," "color loss," and "red discoloration upon heating."

[0015] In the polarizing film laminate of the above embodiment, the polarizing film may have a thickness of 4 to 30 μm.

[0016] In another embodiment of the polarizing film laminate of the present invention, the polarizing film laminate includes a polarizing film made of a polyvinyl alcohol resin and an optically transparent polarizing film protective film bonded to at least the viewing side surface of the polarizing film directly or via another optical film, and the x-axis represents the iodine concentration (wt.%) of the polarizing film, and the y-axis represents the moisture content (g / m 2 ) in the xy Cartesian coordinate system, the iodine concentration is 4.5 wt.% and the water content is 1.9 g / m 2 The sixth coordinate point, iodine concentration 1.8 wt.% and water content 4.2 g / m 2 a sixth line segment connecting the second coordinate point and the second coordinate point; 2 A second line segment connecting the third coordinate point and the third coordinate point having an iodine concentration of 4.5 wt.% and a water content of 3.4 g / m 2 the iodine concentration and moisture content are included within an area surrounded by a seventh line segment connecting the sixth coordinate point and the seventh coordinate point, and an eighth line segment connecting the sixth coordinate point and the seventh coordinate point, and the polarizing film protective film is a light absorbing layer having a light absorbing ability and is characterized in that the light transmittance at a wavelength of 380 nm is 5% or less.

[0017] In the polarizing film laminate of the above embodiment, the sixth coordinate point is a polarizing film having an iodine concentration of 4.0 wt.% and a water content of 2.4 g / m 2The seventh coordinate point is an iodine concentration of 4.0 wt.% and a water content of 3.7 g / m 2 It may be the ninth coordinate point of the The sixth coordinate point has an iodine concentration of 3.7 wt.% and a water content of 2.6 g / m 2 The seventh coordinate point may be the tenth coordinate point, and the seventh coordinate point may be the fourth coordinate point.

[0018] In the polarizing film laminate of the above embodiment, the polarizing film may have a thickness of 11 to 30 μm.

[0019] In another embodiment of the polarizing film laminate of the present invention, the polarizing film laminate includes a polarizing film made of a polyvinyl alcohol resin and an optically transparent polarizing film protective film bonded to at least the viewing side surface of the polarizing film directly or via another optical film, and the x-axis represents the iodine concentration (wt.%) of the polarizing film, and the y-axis represents the moisture content (g / m 2 ) in the xy Cartesian coordinate system, the iodine concentration is 6.0 wt.% and the water content is 0.7 g / m 2 The first coordinate point of the sample, the iodine concentration of 3.7 wt.% and the water content of 2.6 g / m 2 a ninth line segment connecting the tenth coordinate point and the iodine concentration of 5.7 wt.% and the water content of 2.6 g / m 2 a tenth line segment connecting the fourth coordinate point and the fourth coordinate point; an iodine concentration of 7.0 wt.% and a water content of 0.7 g / m 2 the iodine concentration and the moisture content are included within an area surrounded by an eleventh line segment connecting the first coordinate point to the fifth coordinate point, and a fifth line segment connecting the first coordinate point to the fifth coordinate point, and the polarizing film protective film is a light absorbing layer having a light absorbing ability and is characterized in that the light transmittance at a wavelength of 380 nm is 5% or less.

[0020] In the polarizing film laminate of the above embodiment, the polarizing film may have a thickness of 4 to 11 μm.

[0021] Furthermore, in the polarizing film laminate of the above embodiment, the polarizing film protective film preferably has a light transmittance of 35% or less at a wavelength of 390 nm, and the polarizing film protective film preferably has a light transmittance of 70% or less at a wavelength of 400 nm.

[0022] In the polarizing film laminate of the above embodiment, the polarizing film preferably contains zinc.

[0023] Furthermore, in the polarizing film laminate of the above embodiment, a sample consisting of a polarizing film laminate and glass plates laminated on both sides of the polarizing film laminate via an adhesive was subjected to irradiation with xenon light at an integrated irradiance of 100 W / m2 in a wavelength range of 300 to 400 nm in an atmosphere with a black panel temperature of 89°C and 30% RH. 2 It is preferable that the single-piece transmittance after irradiation for 200 hours is -0.5 or more compared to the single-piece transmittance before irradiation. This can effectively solve the problem of polyenation.

[0024] In the polarizing film laminate of the above embodiment, a sample comprising a polarizing film laminate and glass plates laminated on both sides of the polarizing film laminate via an adhesive has an irradiance of 100 W / m2, which is calculated by irradiating xenon light in a wavelength range of 300 to 400 nm under an atmosphere of a black panel temperature of 89°C and 30% RH. 2 After irradiation with UV light for 200 hours, it is preferable that the change in cross transmittance at a wavelength of 410 nm is less than 1% and the change in cross transmittance at a wavelength of 700 nm is less than 5%. This effectively solves the problem of color loss.

[0025] In the polarizing film laminate of the above embodiment, a sample comprising a polarizing film laminate and glass plates laminated on both sides of the polarizing film laminate via an adhesive has an irradiance of 100 W / m2, which is calculated by irradiating xenon light in a wavelength range of 300 to 400 nm under an atmosphere of a black panel temperature of 89°C and 30% RH. 2After irradiation with UV light for 200 hours, it is preferable that the change in cross transmittance at a wavelength of 410 nm is 1% or more and the change in cross transmittance at a wavelength of 700 nm is less than 5%. This effectively solves the problem of reddening due to heating.

[0026] Furthermore, in order to solve the above problems, an optical display panel according to one embodiment of the present invention is characterized as an optical display panel to be attached to the body of a powered vehicle, comprising an optical display cell, any of the above-described polarizing film laminates bonded to one side of the optical display cell directly or via another optical film, and an optically transparent cover plate arranged along the polarizing film laminate on the opposite side to the optical display cell, wherein the optical display cell, the polarizing film laminate, and the transparent cover plate are bonded by a transparent adhesive layer that fills the spaces between them so that there are no gaps.

[0027] In the optical display panel of the above aspect, the transparent cover plate may have a function as a capacitive touch sensor.

[0028] In the optical display panel of the above embodiment, an ITO layer serving as a component of a capacitive touch sensor may be provided between the transparent cover plate and the polarizing film laminate.

[0029] A polarizing film laminate with a transparent adhesive layer according to one embodiment of the present invention comprises a polarizing film made of a polyvinyl alcohol-based resin, a polarizing film laminate including an optically transparent polarizing film protective film bonded to at least the viewing side surface of the polarizing film directly or via another optical film, and a transparent adhesive layer laminated on the viewing side of the polarizing film laminate, and the x-axis represents the iodine concentration (wt.%) of the polarizing film, and the y-axis represents the moisture content (g / m) of the polarizing film laminate. 2 ) in the xy Cartesian coordinate system, the iodine concentration is 6.0 wt.% and the water content is 0.7 g / m 2 The first coordinate point of the sample, the iodine concentration of 1.8 wt.% and the water content of 4.2 g / m 2a first line segment connecting the second coordinate point and the second coordinate point; 2 a second line segment connecting the third coordinate point and the third coordinate point; 2 a third line segment connecting the fourth coordinate point and the fourth coordinate point; 2 the iodine concentration and moisture content are included within an area surrounded by a fourth line segment connecting the first coordinate point to the fifth coordinate point, and a fifth line segment connecting the first coordinate point to the fifth coordinate point, and of the transparent adhesive layer and the polarizing film protection film, at least the transparent adhesive layer is a light absorbing layer having light absorbing ability, and the laminate of the transparent adhesive layer and the polarizing film protection film has a light transmittance of 5% or less at a wavelength of 380 nm.

[0030] A polarizing film laminate with a transparent adhesive layer according to another embodiment of the present invention comprises a polarizing film made of a polyvinyl alcohol-based resin, a polarizing film laminate including an optically transparent polarizing film protective film bonded directly or via another optical film to the surface of the polarizing film opposite to the viewing side, and a transparent adhesive layer laminated on the viewing side of the polarizing film laminate, and the x-axis represents the iodine concentration (wt.%) of the polarizing film, and the y-axis represents the moisture content (g / m) of the polarizing film laminate. 2 ) in the xy Cartesian coordinate system, the iodine concentration is 6.0 wt.% and the water content is 0.7 g / m 2 The first coordinate point of the sample, the iodine concentration of 1.8 wt.% and the water content of 4.2 g / m 2 a first line segment connecting the second coordinate point and the second coordinate point; 2 a second line segment connecting the third coordinate point and the third coordinate point; 2 a third line segment connecting the fourth coordinate point and the fourth coordinate point; 2the iodine concentration and water content are included within an area surrounded by a fourth line segment connecting the first coordinate point to the fifth coordinate point, and a fifth line segment connecting the first coordinate point to the fifth coordinate point, the transparent adhesive layer is a light absorbing layer having light absorbing ability, and the transparent adhesive layer has a light transmittance of 5% or less at a wavelength of 380 nm.

[0031] A polarizing film assembly according to one aspect of the present invention includes a polarizing film made of a polyvinyl alcohol-based resin, a polarizing film laminate including an optically transparent polarizing film protective film bonded to at least the viewing side surface of the polarizing film directly or via another optical film, a transparent adhesive layer laminated on the viewing side of the polarizing film laminate, and an optically transparent cover plate laminated on the viewing side of the transparent adhesive layer, and the x-axis represents the iodine concentration (wt.%) of the polarizing film, and the y-axis represents the moisture content (g / m) of the polarizing film laminate. 2 ) in the xy Cartesian coordinate system, the iodine concentration is 6.0 wt.% and the water content is 0.7 g / m 2 The first coordinate point of the sample, the iodine concentration of 1.8 wt.% and the water content of 4.2 g / m 2 a first line segment connecting the second coordinate point and the second coordinate point; 2 a second line segment connecting the third coordinate point and the third coordinate point; 2 a third line segment connecting the fourth coordinate point and the fourth coordinate point; 2 the iodine concentration and moisture content are included within an area surrounded by a fourth line segment connecting the first coordinate point to the fifth coordinate point, a fourth line segment connecting the first coordinate point to the fifth coordinate point, and a fifth line segment connecting the first coordinate point to the fifth coordinate point, and among the polarizing film protection film, the transparent adhesive layer, and the transparent cover plate, at least the transparent cover plate is a light absorbing layer having light absorbing ability, and the laminate of the polarizing film protection film, the transparent adhesive layer, and the transparent cover plate has a light transmittance of 5% or less at a wavelength of 380 nm.

[0032] A polarizing film assembly according to another embodiment of the present invention includes a polarizing film laminate including a polarizing film made of a polyvinyl alcohol-based resin, an optically transparent polarizing film protective film bonded directly or via another optical film to the surface of the polarizing film opposite to the viewing side, a transparent adhesive layer laminated on the viewing side of the polarizing film laminate, and an optically transparent cover plate laminated on the viewing side of the transparent adhesive layer, and the x-axis represents the iodine concentration (wt.%) of the polarizing film, and the y-axis represents the moisture content (g / m) of the polarizing film laminate. 2 ) in the xy Cartesian coordinate system, the iodine concentration is 6.0 wt.% and the water content is 0.7 g / m 2 The first coordinate point of the sample, the iodine concentration of 1.8 wt.% and the water content of 4.2 g / m 2 a first line segment connecting the second coordinate point and the second coordinate point; 2 a second line segment connecting the third coordinate point and the third coordinate point; 2 a third line segment connecting the fourth coordinate point and the fourth coordinate point; 2 the iodine concentration and moisture content are included within an area surrounded by a fourth line segment connecting the first coordinate point to the fifth coordinate point, and a fifth line segment connecting the first coordinate point to the fifth coordinate point, and of the transparent adhesive layer and the transparent cover plate, at least the transparent cover plate is a light absorbing layer having light absorbing ability, and the laminate of the transparent adhesive layer and the transparent cover plate has a light transmittance of 5% or less at a wavelength of 380 nm. Effect of the Invention

[0033] According to the present invention, the problems of "polyenization," "color loss," and "reddening upon heating" can be comprehensively solved by adjusting the iodine concentration in the polarizing film and the moisture content in the polarizing film laminate, as well as by suppressing the effects of sunlight irradiation. [Brief description of the drawings]

[0034] [Figure 1] FIG. 2 is a schematic diagram showing a layer structure of an optical display panel. [Diagram 2] 1A to 1C are diagrams illustrating an example of a method for producing a polarizing film. [Diagram 3] FIG. 2 is a diagram showing an example of a layer structure of a polarizing film protective film located on the viewing side. [Figure 4] FIG. 13 is a diagram showing a calibration curve for determining the iodine concentration of a polarizing film. [Diagram 5] FIG. 1 is a diagram showing a structure for a reliability test. [Figure 6] FIG. 1 is a diagram in which the results of Examples and Comparative Examples are plotted with the results of Examples at the center. [Figure 7] FIG. 2 is a diagram in which the results of the Examples and Comparative Examples are plotted with the Comparative Examples at the center. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] Hereinafter, a preferred embodiment of the present invention will be described with reference to the accompanying drawings. For convenience of explanation, only the preferred embodiment is shown, and it is not intended to limit the present invention.

[0036] The present invention is directed to an optical display panel, for example, an optical display panel attached to the body of a motor vehicle such as an automobile, train, or airplane, and a polarizing film laminate used in the optical display panel. Here, "attached to the vehicle body" does not necessarily mean that the optical display panel or the polarizing film laminate is fixed to the vehicle body, but also means that the optical display panel or the polarizing film laminate is freely mounted or carried in the motor vehicle, for example, as in the case of an optical display panel or a polarizing film laminate used in a smartphone, etc. Furthermore, "attached to the vehicle body" includes all situations in which the optical display panel or the polarizing film laminate is used together with a motor vehicle and may be exposed to a high temperature or high humidity environment.

[0037] 1.Optical display panel FIG. 1 is a schematic diagram showing an example of a layer structure of an optical display panel 1. The optical display panel 1 includes at least an optical display cell 10, a polarizing film laminate 12 laminated on one surface 10a (the viewing side) of the optical display cell 10, and an optically transparent cover plate 14 arranged along the polarizing film laminate 12 on the side opposite to the optical display cell 10, i.e., the viewing side. The optical display cell 10 and the polarizing film laminate 12 are bonded together without any gaps using a transparent adhesive layer made of a transparent adhesive (PSA) 11. Similarly, the cover plate 14 and the polarizing film laminate 12 are bonded together without any gaps using a transparent adhesive layer made of a transparent adhesive (OCA) 13 laminated on the viewing side of the polarizing film laminate 12 to form a polarizing film assembly 19 including the cover plate 14, the transparent adhesive 13, and the polarizing film laminate 12. Another polarizing film laminate 17 is disposed on the other surface 10b side of the optical display cell 10 via a transparent adhesive (PSA) 16. In this specification, the term "adhesion" includes adhesion (pressure-sensitive adhesion) unless otherwise specified. The optical display cell 10 and the polarizing film laminate 12 may be directly adhered to each other by a transparent adhesive 11, but may also be adhered to each other via other optical films (not shown) such as a retardation film or a viewing angle compensation film, if necessary.

[0038] 1-1.Optical display cell Examples of the optical display cell 10 include a liquid crystal cell and an organic electroluminescent cell. As the organic EL cell, a light-emitting body (organic electroluminescence light-emitting body) formed by sequentially laminating a transparent electrode, an organic light-emitting layer, and a metal electrode on a transparent substrate is preferably used. The organic light-emitting layer is a laminate of various organic thin films, and various layer configurations can be adopted, such as a laminate of a hole injection layer made of a triphenylamine derivative or the like and a light-emitting layer made of a fluorescent organic solid such as anthracene, a laminate of these light-emitting layers and an electron injection layer made of a perylene derivative or the like, or a laminate of a hole injection layer, a light-emitting layer, and an electron injection layer.

[0039] The liquid crystal cell may be a reflective liquid crystal cell that uses external light, a transmissive liquid crystal cell that uses light from a light source such as a backlight 18, or a semi-transmissive semi-reflective liquid crystal cell that uses both external light and light from a light source. When the liquid crystal cell uses light from a light source, as shown in FIG. 1, a polarizing film laminate 17 is also arranged on the opposite side to the viewing side of the optical display cell (liquid crystal cell) 10, and a light source 18 such as a backlight is further arranged. The polarizing film laminate 17 on the light source side and the liquid crystal cell 10 are bonded by a layer of an appropriate transparent adhesive 16. The liquid crystal cell may be driven in any type such as VA mode, IPS mode, TN mode, STN mode, or bend orientation (π type).

[0040] 1-2.Cover plate Examples of the cover plate 14 include a transparent plate (window layer) and a touch panel. The transparent plate has appropriate mechanical strength and thickness. Such a transparent plate may be, for example, a transparent resin plate such as an acrylic resin or a polycarbonate resin, or a glass plate. The surface of the cover plate 14 may be subjected to low reflection treatment, for example, by a low reflection film (not shown). The touch panel may be, for example, a resistive film type, a capacitive type, an optical type, an ultrasonic type, or a glass plate or a transparent resin plate having a touch sensor function.

[0041] The cover plate 14 may contain an ultraviolet absorbing agent to form a light absorbing layer having light absorbing ability, in other words, the transmittance of the cover plate 14 to ultraviolet light may be set to a desired value. For example, the cover plate 14 may be formed of a transparent resin plate such as an acrylic resin or a polycarbonate resin, or a glass plate, and during the preparation, for example, a benzotriazole-based, benzophenone-based, salicylic acid phenyl ester-based, or triazine-based ultraviolet absorbing agent may be included. Examples of the benzotriazole-based ultraviolet absorbing agent include 2-(5-methyl-2-hydroxyphenyl)benzotriazole, 2-(2H-benzotriazol-2-yl)-p-cresol, 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol, and 2-(2'-hydroxy-5'methacryloxyethylphenyl)-2H-benzotriazole. Examples of benzophenone-based ultraviolet absorbers include 2-hydroxy-4-octoxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxy-4'-chlorobenzophenone, 2,2-dihydroxy-4-methoxybenzophenone, 2,2-dihydroxy-4,4'-dimethoxybenzophenone, etc. Examples of salicylic acid phenyl ester-based ultraviolet absorbers include pt-butylphenyl salicylic acid ester, etc.Examples of triazine-based ultraviolet absorbers include 2,4-diphenyl-6-(2-hydroxy-4-methoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-ethoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-(2-hydroxy-4-propoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-hetoxyphenyl)-1,3,5-triazine, and 2,4-diphenyl-6-(2-hydroxy-4-methoxyphenyl)-1,3,5-triazine. By mixing an ultraviolet absorbing agent such as 2,4-diphenyl-6-(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-dodecyloxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-benzyloxyphenyl)-1,3,5-triazine, or 2,4-diphenyl-6-(2-hydroxy-4-butoxyethoxyphenyl)-1,3,5-triazine into the transparent resin, the cover plate 14 can be used as a light absorbing layer. By providing a light absorbing layer, the transmittance of ultraviolet light in the polarizing film assembly 19 including the polarizing film laminate 12 can be set to a desired value, and the problems of "polyenization," "color loss," and "red discoloration upon heating" can be more effectively and comprehensively solved. In the case where only the cover plate 14 is used as the light absorbing layer, for example, the transmittance at a wavelength of 380 nm is preferably 5% or less, more preferably 3% or less, and even more preferably 2% or less. The lower limit is, for example, 0.1% or more, 1% or more. The transmittance at a wavelength of 390 nm is preferably 35% or less, more preferably 30% or less, and even more preferably 28% or less. The lower limit is, for example, 10% or more, 20% or more, or 25% or more. The transmittance at a wavelength of 400 nm is preferably 70% or less, more preferably 68% or less. The lower limit is, for example, 50% or more, 60% or more, or 65% or more. The transmittance at a wavelength of 420 nm is preferably 90% or less. The lower limit is, for example, 80% or more, or 85% or more. These transmittances indicate the transmittance of the cover plate 14 in the initial state.In addition to the ultraviolet absorber, an infrared absorber such as a phthalocyanine-based light absorber, a naphthalocyanine-based light absorber, a polymethine-based light absorber, a diphenylmethane-based light absorber, a triphenylmethane-based light absorber, a quinone-based light absorber, or an azo-based light absorber may be mixed.

[0042] When a capacitive touch panel is used as the cover plate 14, it is preferable to provide a front transparent plate made of glass or a transparent resin plate on the viewing side further than the touch panel. In this case, an ITO layer (not shown) that is a component of the capacitive touch sensor is provided on the transparent adhesive 13 that bonds the cover plate 14 and the polarizing film laminate 12.

[0043] 1-3. Transparent adhesive As the transparent adhesives 11, 13, and 16, various adhesives such as those disclosed in Japanese Patent No. 6071459 can be appropriately used. For example, a (meth)acrylic adhesive can be used, and a curing adhesive that does not contain (meth)acrylic acid can be used. As an example of the latter, for example, an isoprene-based UV-curing adhesive is preferably used. The isoprene-based UV-curing adhesive may contain an isoprene derivative in addition to isoprene as a monomer component. The adhesive may contain a monomer component other than an isoprene-based monomer. A (meth)acrylic acid derivative such as a (meth)acrylic acid ester may be contained as a monomer component. In addition, in order to suppress the decrease in transmittance due to polyenization of polyvinyl alcohol, it is effective to reduce the content of acid components in the transparent adhesives 11, 13, and 16.

[0044] The transparent adhesives 11, 13, and 16, for example, the transparent adhesive 13 (transparent adhesive layer) laminated on the viewing side of the polarizing film laminate 12, may contain an ultraviolet absorbing agent to form a light absorbing layer having light absorbing ability. In other words, the transmittance of the transparent adhesive to ultraviolet light may be set to a desired value. For example, the transparent adhesive is formed of a (meth)acrylic adhesive, and during the preparation, for example, benzotriazole-based, benzophenone-based, salicylic acid phenyl ester-based, and triazine-based ultraviolet absorbing agents may be included. Examples of benzotriazole-based ultraviolet absorbing agents include 2-(5-methyl-2-hydroxyphenyl)benzotriazole, 2-(2H-benzotriazol-2-yl)-p-cresol, 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol, and 2-(2'-hydroxy-5'methacryloxyethylphenyl)-2H-benzotriazole. Examples of benzophenone-based ultraviolet absorbers include 2-hydroxy-4-octoxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxy-4'-chlorobenzophenone, 2,2-dihydroxy-4-methoxybenzophenone, 2,2-dihydroxy-4,4'-dimethoxybenzophenone, etc. Examples of salicylic acid phenyl ester-based ultraviolet absorbers include pt-butylphenyl salicylic acid ester, etc.Examples of triazine-based ultraviolet absorbers include 2,4-diphenyl-6-(2-hydroxy-4-methoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-ethoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-(2-hydroxy-4-propoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-hetoxyphenyl)-1,3,5-triazine, and 2,4-diphenyl-6-(2-hydroxy-4-methoxyphenyl)-1,3,5-triazine. By mixing an ultraviolet absorber such as 2,4-diphenyl-6-(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-dodecyloxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-benzyloxyphenyl)-1,3,5-triazine, or 2,4-diphenyl-6-(2-hydroxy-4-butoxyethoxyphenyl)-1,3,5-triazine into the transparent resin, the transparent adhesive can be used as a light absorbing layer. By providing such a light absorbing layer, the transmittance of ultraviolet light in the polarizing film laminate 12 with the transparent adhesive layer or the polarizing film assembly 19 including the polarizing film laminate 12 can be set to a desired value, and the problems of "polyenization", "color loss", and "red discoloration upon heating" can be more effectively and comprehensively solved. In the case where only the transparent adhesive 13 is used as the light absorbing layer, for example, the transmittance at a wavelength of 380 nm is preferably 5% or less, more preferably 3% or less, and even more preferably 2% or less. The lower limit is, for example, 0.1% or more, 1% or more. The transmittance at a wavelength of 390 nm is preferably 35% or less, more preferably 30% or less, and even more preferably 28% or less. The lower limit is, for example, 10% or more, 20% or more, or 25% or more. The transmittance at a wavelength of 400 nm is preferably 70% or less, and more preferably 68% or less. The lower limit is, for example, 50% or more, 60% or more, or 65% or more. The transmittance at a wavelength of 420 nm is preferably 90% or less. The lower limit is, for example, 80% or more, or 85% or more. These transmittances indicate the transmittance of the transparent adhesive in the initial state.In addition to the ultraviolet absorber, an infrared absorber such as a phthalocyanine-based light absorber, a naphthalocyanine-based light absorber, a polymethine-based light absorber, a diphenylmethane-based light absorber, a triphenylmethane-based light absorber, a quinone-based light absorber, or an azo-based light absorber may be mixed.

[0045] 2. Polarizing film laminate The polarizing film laminate 12 includes at least a polarizing film 120 and a polarizing film protective film 121 bonded to at least the viewing side of the polarizing film 120. The polarizing film laminate 12 may further include a polarizing film protective film 122 on the side opposite to the viewing side of the polarizing film 120. In addition to or instead of using the cover plate 14 and / or the transparent adhesive 13 as a light absorbing layer, the polarizing film protective film 121 may function as a light absorbing layer. By providing a light absorbing layer, the ultraviolet transmittance of the polarizing film laminate 12 itself can be set to a desired value, and the problems of "polyenization", "color loss", and "red discoloration upon heating" can be more effectively and comprehensively solved. Although not particularly shown, another optical film may be provided between the polarizing film 120 and the polarizing film protective films 121 and 122.

[0046] In order to comprehensively solve the problems caused by use environments such as high temperature or high humidity and by irradiation with sunlight, particularly the problems of "polyenation," "color loss," and "red discoloration upon heating," the present invention focuses on the iodine concentration (wt.%) of the polarizing film 120 and the moisture content (g / m 2 ) of the polarizing film laminate 12. 2 These values ​​can be adjusted, for example, during the production of the polarizing film or the polarizing film laminate.

[0047] 2-1.Polarizing film The polarizing film 120 is made of a polyvinyl alcohol (PVA)-based resin film containing iodine. PVA or its derivatives are used as the material for the PVA-based film applied to the polarizing film. Examples of PVA derivatives include polyvinyl formal, polyvinyl acetal, etc., as well as those modified with olefins such as ethylene and propylene, unsaturated carboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, their alkyl esters, and acrylamide. PVA with a polymerization degree of about 1000 to 10000 and a saponification degree of about 80 to 100 mol % is generally used. PVA-based films made of these materials tend to easily absorb moisture.

[0048] The PVA-based film may contain additives such as a plasticizer. Examples of the plasticizer include polyols and their condensates, such as glycerin, diglycerin, triglycerin, ethylene glycol, propylene glycol, and polyethylene glycol. The amount of the plasticizer used is not particularly limited, but is preferably 20% by weight or less in the PVA-based film.

[0049] 2-1-1. Manufacturing of polarizing film In producing a polarizing film having a thickness of 6 μm or more, for example, the PVA-based film is subjected to a dyeing treatment in which the film is dyed with iodine, and a stretching treatment in which the film is stretched in at least one direction. In general, a method is adopted in which the PVA-based film is subjected to a series of treatments including swelling, dyeing, crosslinking, stretching, washing with water, and drying.

[0050] The swelling treatment is carried out, for example, by immersing the PVA-based film in a swelling bath (water bath). This treatment cleans the stains and antiblocking agent on the surface of the PVA-based film, and also swells the PVA-based film, thereby preventing non-uniformity such as uneven dyeing. Glycerin, potassium iodide, etc. may be appropriately added to the swelling bath. The temperature of the swelling bath is, for example, about 20 to 60°C, and the immersion time in the swelling bath is, for example, about 0.1 to 10 minutes.

[0051] The dyeing process is carried out, for example, by immersing the PVA film in an iodine solution. The iodine solution is usually an aqueous iodine solution, containing iodine and potassium iodide as a dissolving agent. The iodine concentration is, for example, about 0.01 to 1 wt%, and preferably 0.02 to 0.5 wt%. The potassium iodide concentration is, for example, about 0.01 to 10 wt%, and preferably 0.02 to 8 wt%.

[0052] In the dyeing treatment, the temperature of the iodine solution is, for example, about 20 to 50° C., preferably 25 to 40° C. The immersion time is, for example, about 10 to 300 seconds, preferably 20 to 240 seconds. In the iodine dyeing treatment, conditions such as the concentration of the iodine solution, the immersion temperature of the PVA-based film in the iodine solution, and the immersion time are adjusted so that the iodine content and potassium content in the PVA-based film are within the above-mentioned ranges.

[0053] The crosslinking treatment is carried out, for example, by immersing a PVA-based film dyed with iodine in a treatment bath containing a crosslinking agent. Any appropriate crosslinking agent is used as the crosslinking agent. Specific examples of the crosslinking agent include boric acid, boron compounds such as borax, glyoxal, glutaraldehyde, and the like. These are used alone or in combination. Water is generally used as a solvent for the crosslinking bath solution, but an appropriate amount of an organic solvent compatible with water may be added. The crosslinking agent is used in a ratio of, for example, 1 to 10 parts by weight with respect to 100 parts by weight of the solvent. It is desirable that the crosslinking bath solution further contains an auxiliary such as an iodide. The concentration of the auxiliary is preferably 0.05 to 15% by weight, more preferably 0.5 to 8% by weight. The temperature of the crosslinking bath is, for example, about 20 to 70°C, preferably 40 to 60°C. The immersion time in the crosslinking bath is, for example, about 1 second to 15 minutes, preferably 5 seconds to 10 minutes.

[0054] The stretching process is a process in which a PVA-based film is stretched in at least one direction. In general, the PVA-based film is uniaxially stretched in the conveying direction (longitudinal direction). The stretching method is not particularly limited, and either a wet stretching method or a dry stretching method can be used. When the wet stretching method is used, the PVA-based film is stretched to a predetermined ratio in a treatment bath. As a solution for the stretching bath, a solution in which a compound required for various treatments is added to a solvent such as water or an organic solvent (e.g., ethanol) is preferably used. Examples of the dry stretching method include a roll-to-roll stretching method, a heated roll stretching method, and a compression stretching method. In the production of a polarizing film, the stretching process may be performed at any stage. Specifically, it may be performed simultaneously with swelling, dyeing, and crosslinking, or may be performed before or after each of these treatments. In addition, the stretching may be performed in multiple stages. The cumulative stretching ratio of the PVA-based film is, for example, 5 times or more, and preferably about 5 to 7 times.

[0055] The PVA film (stretched film) that has been subjected to the above-mentioned treatments is subjected to water washing treatment and drying treatment according to a conventional method.

[0056] The water washing treatment is carried out, for example, by immersing the PVA film in a water washing bath. The water washing bath may be pure water or an aqueous solution of an iodide (e.g., potassium iodide, sodium iodide, etc.). The concentration of the aqueous iodide solution is preferably 0.1 to 10% by weight. An auxiliary such as zinc sulfate or zinc chloride may be added to the aqueous iodide solution.

[0057] The washing temperature is, for example, in the range of 5 to 50° C., preferably 10 to 45° C., and more preferably 15 to 40° C. The immersion time is, for example, about 10 to 300 seconds, and preferably 20 to 240 seconds. The washing treatment may be carried out only once, or may be carried out multiple times as necessary. When the washing treatment is carried out multiple times, the type and concentration of additives contained in the washing bath used for each treatment are appropriately adjusted.

[0058] The drying treatment of the PVA-based film is carried out by any appropriate method (for example, natural drying, air drying, heat drying).

[0059] 2-1-2. Manufacturing of polarizing film A polarizing film with a thickness of less than 6 μm can be produced, for example, by the production method disclosed in Japanese Patent No. 4751481. This production method includes a laminate production process in which a PVA-based resin layer is formed on a thermoplastic substrate, a stretching process in which the PVA-based resin layer is stretched together with the thermoplastic substrate, and a dyeing process in which a dichroic material is adsorbed on the PVA resin layer. If necessary, insolubilization and crosslinking processes, drying processes, washing processes, etc. of the PVA-based resin layer can also be applied. The stretching process can be carried out before or after the dyeing process, and any stretching method, such as air stretching or stretching in water, such as an aqueous boric acid solution, can be used. Furthermore, the stretching may be a one-stage stretching or a multi-stage stretching of two or more stages.

[0060] An example of a method for producing a polarizing film will be described with reference to Fig. 2. In this example, a PVA-based resin layer formed on a resin substrate is stretched together with the resin substrate to produce a polarizing film.

[0061] [Laminate preparation process (A)] First, a 200 μm thick amorphous ester thermoplastic resin substrate having a glass transition temperature of 75° C., for example, isophthalic acid copolymerized polyethylene terephthalate (hereinafter referred to as “amorphous PET”) 6 obtained by copolymerizing 6 mol% isophthalic acid, and a 4 to 5 wt % aqueous PVA solution obtained by dissolving PVA powder having a degree of polymerization of 1000 or more and a degree of saponification of 99% or more in water are prepared. Next, in a laminate preparation device 20 equipped with a coating means 21, a drying means 22, and a surface modification treatment device 23, the PVA aqueous solution is applied to the amorphous PET substrate 6, and dried at a temperature of 50 to 60° C. to form a 7 μm thick PVA layer 2 having a glass transition temperature of 80° C. on the PET substrate 6. This produces a laminate 7 including a 7 μm thick PVA layer. At this time, the surface of the amorphous PET substrate 6 is corona-treated by the surface modification treatment device 23, thereby improving the adhesion between the amorphous PET substrate 6 and the PVA layer 2 formed thereon.

[0062] Next, the laminate 7 including the PVA layer is subjected to the following processes including a two-stage stretching process of auxiliary stretching in air and stretching in boric acid water, and finally produced as a polarizing film having a thickness of 3 μm.

[0063] [Air-assisted stretching process (B)] In the first stage of the in-air auxiliary stretching process (B), the laminate 7 including the 7 μm-thick PVA layer 2 is stretched together with the PET substrate 6 to produce a "stretched laminate 8" including a 5 μm-thick PVA layer 2. Specifically, in an in-air auxiliary stretching processing device 30 in which a stretching means 31 is provided within an oven 33, the laminate 7 including the 7 μm-thick PVA layer 2 is subjected to the stretching means 31 of the oven 33 set to a stretching temperature environment of 130° C., and is stretched uniaxially at the free end to a stretch ratio of 1.8 times to produce a stretched laminate 8. At this stage, a roll 8' of the stretched laminate 8 can be produced by a winding device 32 provided next to the oven 30.

[0064] [Dyeing process (C)] Next, a dyeing process (C) is performed to produce a colored laminate 9 in which iodine, a dichroic material, is adsorbed onto the 5 μm-thick PVA layer 2 in which the PVA molecules are oriented. Specifically, in a dyeing device 40 equipped with a dye bath 42 of a dyeing solution 41, the stretched laminate 8 unwound from a unwinding device 43 equipped with a roll 8' attached to the dyeing device 40 is immersed in the dyeing solution 41 containing iodine and potassium iodide at a liquid temperature of 30° C. for an arbitrary time such that the single-unit transmittance of the PVA layer constituting the polarizing film to be finally produced is 40 to 44%, thereby producing a colored laminate 9 in which iodine is adsorbed onto the oriented PVA layer 2 of the stretched laminate 8.

[0065] In this treatment, the dyeing solution 41 contains water as a solvent and has an iodine concentration of 0.30% by weight so as not to dissolve the PVA layer 2 contained in the stretched laminate 8. The dyeing solution 41 also contains a potassium iodide concentration of 2.1% by weight so that the iodine is dissolved in water. The ratio of the concentrations of iodine and potassium iodide is 1:7. More specifically, the stretched laminate 8 is immersed for 60 seconds in the dyeing solution 41 having an iodine concentration of 0.30% by weight and a potassium iodide concentration of 2.1% by weight to produce a colored laminate 9 in which iodine is adsorbed into the 5 μm-thick PVA layer 2 in which the PVA molecules are oriented.

[0066] [Stretching treatment in boric acid water (D)] The colored laminate 9 including the PVA layer 2 in which iodine is oriented is further stretched by the second-stage stretching treatment in boric acid water to produce an optical film laminate 60 including a PVA layer in which iodine is oriented, which constitutes a 3 μm-thick polarizing film. Specifically, in a boric acid water stretching treatment device 50 equipped with a boric acid bath 52 of an aqueous boric acid solution 51 and a stretching means 53, the colored laminate 9 continuously fed from the dyeing device 40 is immersed in the boric acid aqueous solution 51 containing boric acid and potassium iodide and set to a stretching temperature environment of 65° C., and then is subjected to the stretching means 53 provided in the boric acid water treatment device 50 to uniaxially stretch the free end to a stretch ratio of 3.3 times, thereby producing an optical film laminate 60 including a 3 μm-thick PVA layer.

[0067] [Cleaning process (G)] Next, the optical film laminate 60 including the polarizing film is preferably sent directly to a cleaning process (G). The purpose of the cleaning process (G) is to wash away unnecessary residues adhering to the surface of the polarizing film with a cleaning liquid 81 in a cleaning device 80. However, the cleaning process (G) may be omitted, and the removed optical film laminate 60 including the polarizing film may be sent directly to a drying process (H).

[0068] [Drying process (H)] The washed optical film laminate 60 is sent to a drying process (H) where it is dried. Next, the dried optical film laminate 60 is wound up as a continuous web of the optical film laminate 60 by a winding device 91 attached to the drying device 90, and a roll of the optical film laminate 60 including the polarizing film is produced. Any appropriate method can be used for the drying process (H), for example, natural drying, air drying, or heat drying. For example, drying can be performed for 240 seconds with hot air at 60° C. in the drying device 90 of an oven.

[0069] 2-1-3.Other The polarizing film preferably contains zinc. When the polarizing film contains zinc, the decrease in transmittance and the deterioration in hue of the polarizing film laminate after a heating test tend to be suppressed. When the polarizing film contains zinc, the content of zinc in the polarizing film is preferably 0.002 to 2 wt%, more preferably 0.01 to 1 wt%.

[0070] The polarizing film preferably also contains sulfate ions. When the polarizing film contains sulfate ions, there is a tendency that a decrease in the transmittance of the polarizing film laminate after a heating test is suppressed. When the polarizing film contains sulfate ions, the content of sulfate ions in the polarizing film is preferably 0.02 to 0.45% by weight, more preferably 0.05 to 0.35% by weight, and further preferably 0.1 to 0.25% by weight. The content of sulfate ions in the polarizing film is calculated from the sulfur atom content.

[0071] In order to incorporate zinc into the polarizing film, it is preferable to carry out a zinc impregnation treatment in the manufacturing process of the polarizing film. In order to incorporate sulfate ions into the polarizing film, it is preferable to carry out a sulfate ion treatment in the manufacturing process of the polarizing film.

[0072] The zinc impregnation treatment is carried out, for example, by immersing the PVA-based film in a zinc salt solution. As the zinc salt, an inorganic salt compound such as an aqueous solution of zinc halide such as zinc chloride or zinc iodide, zinc sulfate, or zinc acetate is suitable. In addition, various zinc complex compounds may be used for the zinc impregnation treatment. In addition, it is preferable to use an aqueous solution of potassium ion and iodine ion by potassium iodide or the like as the zinc salt solution, since it is easy to impregnate the zinc ion. The concentration of potassium iodide in the zinc salt solution is about 0.5 to 10% by weight, and more preferably 1 to 8% by weight.

[0073] The sulfate ion treatment is carried out, for example, by immersing the PVA-based film in an aqueous solution containing a metal sulfate. The metal sulfate is preferably one that is easily separated into sulfate ions and metal ions in the treatment solution and is easily introduced into the PVA-based film in the form of ions. For example, metals that form metal sulfates include alkali metals such as sodium and potassium; alkaline earth metals such as magnesium and calcium; and transition metals such as cobalt, nickel, zinc, chromium, aluminum, copper, manganese, and iron.

[0074] In the production of a polarizing film, the zinc impregnation treatment and the sulfate ion treatment may be performed at any stage. That is, the zinc impregnation treatment and the sulfate ion treatment may be performed before or after the dyeing treatment. The zinc impregnation treatment and the sulfate ion treatment may be performed simultaneously. It is preferable to use zinc sulfate as the zinc salt and the metal sulfate salt, and to simultaneously perform the zinc impregnation treatment and the sulfate ion treatment by immersing the PVA-based film in a treatment bath containing zinc sulfate. In addition, the zinc salt and the metal sulfate salt may be present in a dyeing solution, and the zinc impregnation treatment and / or the sulfate ion treatment may be performed simultaneously with the dyeing treatment. The zinc impregnation treatment and the sulfate ion treatment may be performed simultaneously with the stretching.

[0075] 2-2. Polarizing film protection film 2-2-1. Polarizing film protection film located on the opposite side to the viewing side 1, examples of materials constituting the polarizing film protective film 122 located on the opposite side to the viewing side of the polarizing film 120 include thermoplastic resins excellent in transparency, mechanical strength, and thermal stability. Specific examples of such thermoplastic resins include cellulose-based resins such as triacetyl cellulose, polyester-based resins, polyethersulfone-based resins, polysulfone-based resins, polycarbonate-based resins, polyamide-based resins, polyimide-based resins, polyolefin-based resins, (meth)acrylic-based resins, cyclic polyolefin-based resins (norbornene-based resins), polyarylate-based resins, polystyrene-based resins, PVA-based resins, and mixtures thereof. The polarizing film protection film 122 may also function as a retardation film.

[0076] The thickness of the polarizing film protection film 122 is appropriately adjusted in order to adjust the moisture content of the polarizing film laminate. From the viewpoints of strength, workability such as handleability, thinness, etc., the thickness is preferably about 1 to 500 μm, more preferably 2 to 300 μm, and even more preferably 5 to 200 μm. One or more kinds of additives may be contained in the polarizing film protection film 122. Examples of additives include ultraviolet absorbers, antioxidants, lubricants, plasticizers, release agents, coloring inhibitors, flame retardants, nucleating agents, antistatic agents, pigments, and colorants.

[0077] 2-2-2. Polarizing film protection film located on the viewing side In the polarizing film laminate 12 of FIG. 1, the polarizing film protective film 121 located on the viewing side of the polarizing film 120 is configured as a light absorbing layer having a light absorbing ability, in other words, the transmittance for ultraviolet rays is set to a desired value. For example, the polarizing film protective film 121 can be configured as a light absorbing layer having a light absorbing ability by including an ultraviolet absorbing agent, but it is not necessary to use an ultraviolet absorbing agent as long as the transmittance for ultraviolet rays can be set to a desired value. For example, an ultraviolet absorbing filter can be used instead of an ultraviolet absorbing agent to achieve a desired transmittance. When only the polarizing film protective film 121 is used as the light absorbing layer, for example, the transmittance at a wavelength of 380 nm is preferably 5% or less, more preferably 3% or less, and even more preferably 2% or less. The lower limit is, for example, 0.1% or more, 1% or more. The transmittance at a wavelength of 390 nm is preferably 35% or less, more preferably 30% or less, and even more preferably 28% or less. The lower limit is, for example, 10% or more, 20% or more, or 25% or more. The transmittance at a wavelength of 400 nm is preferably 70% or less, more preferably 68% or less. The lower limit is, for example, 50% or more, 60% or more, or 65% or more. The transmittance at a wavelength of 420 nm is preferably 90% or less. The lower limit is, for example, 80% or more, or 85% or more. In addition to the ultraviolet absorbing agent, an infrared absorbing agent such as a phthalocyanine light absorbing agent, a naphthalocyanine light absorbing agent, a polymethine light absorbing agent, a diphenylmethane light absorbing agent, a triphenylmethane light absorbing agent, a quinone light absorbing agent, or an azo light absorbing agent may be mixed.

[0078] As the polarizing film protection film 121, for example, the configurations shown in Fig. 3(a) to (c) can be adopted. Any of the polarizing film protection films 121A to C shown in Fig. 3(a) to (c) can be used as the polarizing film protection film 121 shown in Fig. 1. For convenience, these figures also show the polarizing film 120 and the polarizing film protection film 122 shown in Fig. 1 in addition to the polarizing film protection films 121A to C.

[0079] (A) Polarizing film protection film 121A 3(a) includes a polarizing film protective film layer 121A-1 and a coating layer 121A-2. The polarizing film protective film 121A having light absorbing ability can be formed, for example, by incorporating a light absorbing agent into the polarizing film protective film layer 121A-1 and / or by incorporating a light absorbing agent into the coating layer 121A-2.

[0080] Examples of materials constituting the polarizing film protective film layer 121A-1 include thermoplastic resins having excellent transparency, mechanical strength, and thermal stability. Specific examples of such thermoplastic resins include cellulose-based resins such as triacetyl cellulose, polyester-based resins, polyethersulfone-based resins, polysulfone-based resins, polycarbonate-based resins, polyamide-based resins, polyimide-based resins, polyolefin-based resins, (meth)acrylic-based resins, cyclic polyolefin-based resins (norbornene-based resins), polyarylate-based resins, polystyrene-based resins, PVA-based resins, and mixtures thereof. The polarizing film protective film may also function as a retardation film. The thickness of the polarizing film protective film layer 121A-1 is appropriately adjusted in order to adjust the moisture content of the polarizing film laminate 12. From the standpoints of strength, workability such as handleability, thinness, and the like, it is 20 to 60 μm, and preferably 30 to 50 μm. The polarizing film protective film layer 121A-1 may contain one or more kinds of additives, such as antioxidants, lubricants, plasticizers, release agents, coloring inhibitors, flame retardants, nucleating agents, antistatic agents, pigments, and colorants. Examples of the light absorbent contained in the polarizing film protective film layer 121A-1 include benzotriazole-based, benzophenone-based, salicylic acid phenyl ester-based, and triazine-based ultraviolet absorbents. Examples of the benzotriazole-based ultraviolet absorbent include 2-(5-methyl-2-hydroxyphenyl)benzotriazole, 2-(2H-benzotriazol-2-yl)-p-cresol, 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol, and 2-(2'-hydroxy-5'methacryloxyethylphenyl)-2H-benzotriazole. Examples of the benzophenone-based ultraviolet absorbent include 2-hydroxy-4-octoxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxy-4'-chlorobenzophenone, 2,2-dihydroxy-4-methoxybenzophenone, and 2,2-dihydroxy-4,4'-dimethoxybenzophenone. Examples of the salicylic acid phenyl ester-based ultraviolet absorber include pt-butylphenyl salicylic acid ester, etc. Examples of the triazine-based ultraviolet absorber include 2,4-diphenyl-6-(2-hydroxy-4-methoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-ethoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-(2-hydroxy-4-propoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6 ... Diphenyl-6-(2-hydroxy-4-hexyloxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-dodecyloxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-benzyloxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-butoxyethoxyphenyl)-1,3,5-triazine, and the like can be used.These light absorbing agents can be incorporated into the polarizing film protective film by mixing them therein.

[0081] Specific examples of the coating layer 121A-2 include a hard coat layer, an anti-glare layer, an anti-blocking layer, an anti-reflection layer, a conductive layer, and the like. Among them, the manufacturing method of the present invention is particularly useful when forming a hard coat layer. The material constituting the coating layer includes a resin material (monomer, oligomer, prepolymer, and / or polymer). In one embodiment, the resin material includes a thermosetting or photocurable compound. If a material for the coating layer containing a curable compound is used, a hard coat layer or an anti-glare layer can be formed. The curable compound may be any of a monomer, an oligomer, and a prepolymer. As the curable compound, a multifunctional monomer or oligomer may be used, and examples thereof include a monomer or oligomer having two or more (meth)acryloyl groups, a urethane (meth)acrylate or an oligomer of a urethane (meth)acrylate, an epoxy-based monomer or oligomer, and a silicone-based monomer or oligomer. The thickness of the coating layer 121A-2 is 10 μm or less, preferably 8 μm or less, and more preferably 6 μm or less in terms of thinness, etc. The lower limit is, for example, 1 μm or more, 2 μm or more, or 4 μm or more. Examples of the light absorbent contained in the coating layer 121A-2 include benzotriazole-based, benzophenone-based, salicylic acid phenyl ester-based, and triazine-based ultraviolet absorbents. Examples of the benzotriazole-based ultraviolet absorbent include 2-(5-methyl-2-hydroxyphenyl)benzotriazole, 2-(2H-benzotriazol-2-yl)-p-cresol, 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol, and 2-(2'-hydroxy-5'methacryloxyethylphenyl)-2H-benzotriazole. Examples of the benzophenone-based ultraviolet absorbent include 2-hydroxy-4-octoxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxy-4'-chlorobenzophenone, 2,2-dihydroxy-4-methoxybenzophenone, and 2,2-dihydroxy-4,4'-dimethoxybenzophenone. Examples of the salicylic acid phenyl ester-based ultraviolet absorber include pt-butylphenyl salicylic acid ester, etc. Examples of the triazine-based ultraviolet absorber include 2,4-diphenyl-6-(2-hydroxy-4-methoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-ethoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-(2-hydroxy-4-propoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6 ... Diphenyl-6-(2-hydroxy-4-hexyloxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-dodecyloxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-benzyloxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-butoxyethoxyphenyl)-1,3,5-triazine, and the like can be used.These light absorbing agents can be incorporated into the resin that forms the coating layer by mixing them therein.

[0082] In order to achieve the above transmittance, the total thickness of the light absorbing layer constituted by the polarizing film protective film layer 121A-1 and / or the coating layer 121A-2, i.e., the total thickness of the polarizing film protective film layer 121A-1 having light absorbing ability and / or the coating layer 121A-2 having light absorbing ability, is 25 to 65 μm, preferably 35 to 55 μm or less, and more preferably 40 to 50 μm, in order to obtain sufficient light absorbing ability and to have a thin layer structure.

[0083] (B) Polarizing film protection film 121B 3(b) includes a plurality of, here two, polarizing film protective film layers 121B-1 and 121B-3, and an adhesive layer 121B-2 that bonds the polarizing film protective film layers 121B-1 and 121B-3. The polarizing film protective film 121B having light absorbing ability can be formed, for example, by incorporating a light absorbing agent into either one or both of the polarizing film protective film layers 121B-1 and 121B-3.

[0084] The materials constituting the polarizing film protection film layers 121B-1 and 121B-3 can be the same as those constituting the polarizing film protection film layer 121A-1. The light absorbing agent contained in the polarizing film protective film layers 121B-1 and 121B-3 may be the same as the light absorbing agent contained in the polarizing film protective film layer 121A-1. These light absorbing agents may be contained in the polarizing film protective film layer 121A-1 in the same manner as in the polarizing film protective film layer 121A-1.

[0085] In order to achieve the above transmittance, the total thickness of the light absorbing layer constituted by the polarizing film protective film layers 121B-1 and 121B-3, i.e., the total thickness of the polarizing film protective film layers 121B-1 and 121B-3 having light absorbing ability, is 25 to 105 μm, preferably 60 to 100 μm, and more preferably 70 to 90 μm, in order to obtain sufficient light absorbing ability and to have a thin layer structure.

[0086] The adhesive layer 121B-2 may be, for example, an ultraviolet curing adhesive or a dope curing adhesive, which will be described later.

[0087] (C) Polarizing film protection film 121C The polarizing film protective film 121C shown in FIG. 3(c) includes only a polarizing film protective film layer 121C having light absorbing ability.

[0088] The material constituting the polarizing film protection film layer 121C can be the same as that of the polarizing film protection film layer 121A-1. The light absorbing agent contained in the polarizing film protective film layer 121C can be the same as the light absorbing agent contained in the polarizing film protective film layer 121A-1. These light absorbing agents can be contained in the polarizing film protective film layer 121A-1 in the same manner as in the polarizing film protective film layer 121A-1.

[0089] The thickness of the polarizing film protective film layer 121C, i.e., the thickness as a light absorbing layer, is 25 to 105 μm, preferably 60 to 100 μm, and more preferably 70 to 90 μm in terms of obtaining sufficient light absorbing ability and thin layer property, etc. The polarizing film protective film layer 121C can also be regarded as a combination of a plurality of polarizing film protective films 121B-1 and 121B-3 shown in Fig. 3(b) into one.

[0090] 2-2-3.Other The light absorbing layer may be formed by using any one of the cover plate 14, the transparent adhesive 13, and the polarizing film protective film 121, or by combining them. When the light absorbing layer is formed by combining a plurality of layers, the desired transmittance may be appropriately adjusted for the entire device, as in the case of a general device.

[0091] 2-3. Other optical films The polarizing film and the polarizing film protective films 121 and 122 may be directly bonded to each other, or may be laminated with other optical films. The other optical films are not particularly limited, and may be, for example, retardation films, viewing angle compensation films, etc. The retardation films as the other optical films may function as protective films.

[0092] As described above, the polarizing film protective films 121 and 122 may also function as retardation films, but in this case, the retardation film as another optical film may be omitted. On the other hand, even if the polarizing film protective film also functions as a retardation film, a retardation film may be provided as another optical film. In this case, two or more retardation films are substantially included.

[0093] 2-4.Adhesive As the adhesive layer 121B-2 shown in FIG. 3(b), the adhesive used to bond the polarizing film 120 to the polarizing film protective films 121 and 122, or the adhesive used to bond them to other optical films such as retardation films, for example, a radical polymerization curing (ultraviolet ray curing) adhesive, a cationic polymerization curing adhesive, or an aqueous (dope) adhesive can be used.

[0094] (Radical polymerization curing adhesive) The radical polymerization curing adhesive contains a radical polymerizable compound as a curable compound. The radical polymerizable compound may be a compound that is cured by active energy rays or a compound that is cured by heat. Examples of active energy rays include electron beams, ultraviolet rays, and visible light.

[0095] The radical polymerizable compound may be, for example, a compound having a radical polymerizable functional group having a carbon-carbon double bond, such as a (meth)acryloyl group or a vinyl group. As the radical polymerizable compound, a polyfunctional radical polymerizable compound is preferably used. The radical polymerizable compound may be used alone or in combination of two or more kinds. In addition, a polyfunctional radical polymerizable compound and a monofunctional radical polymerizable compound may be used in combination.

[0096] It is preferable to use a compound with a high logP value (octanol / water partition coefficient) as the polymerizable compound, and it is also preferable to select a compound with a high logP value as the radical polymerizable compound. Here, the logP value is an index representing the lipophilicity of a substance, and means the logarithm of the octanol / water partition coefficient. A high logP value means lipophilicity, that is, a low water absorption rate. The logP value can be measured (flask shaking method described in JIS-Z-7260) or calculated based on the structure of each compound that is a component (curable component, etc.) of the curable adhesive (ChemDraw Ultra manufactured by Cambridge Soft).

[0097] The logP value of the radically polymerizable compound is preferably equal to or greater than 2, more preferably equal to or greater than 3, and particularly preferably equal to or greater than 4. Within such a range, deterioration of the polarizer due to moisture can be prevented, and a polarizing film having excellent durability under high temperature and high humidity conditions can be obtained.

[0098] Examples of the polyfunctional radical polymerizable compound include tripropylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol diacrylate, 2-ethyl-2-butylpropanediol di(meth)acrylate, bisphenol A di(meth)acrylate, bisphenol A ethylene oxide adduct di(meth)acrylate, bisphenol A propylene oxide adduct di(meth)acrylate, bisphenol A diglycidyl ether di(meth)acrylate, neopentyl glycol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, ) acrylate, cyclic trimethylolpropane formal (meth)acrylate, dioxane glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, EO-modified diglycerin tetra(meth)acrylate, and other (meth)acrylate esters with polyhydric alcohols; 9,9-bis[4-(2-(meth)acryloyloxyethoxy)phenyl]fluorene; epoxy (meth)acrylate; urethane (meth)acrylate; polyester (meth)acrylate, and the like.

[0099] Among the polyfunctional radical polymerizable compounds, polyfunctional radical polymerizable compounds having a high logP value are preferred. Examples of such compounds include alicyclic (meth)acrylates such as tricyclodecane dimethanol di(meth)acrylate (logP=3.05) and isobornyl (meth)acrylate (logP=3.27); long-chain aliphatic (meth)acrylates such as 1,9-nonanediol di(meth)acrylate (logP=3.68) and 1,10-decanediol diacrylate (logP=4.10); multi-branched (meth)acrylates such as hydroxypivalic acid neopentyl glycol (meth)acrylic acid adduct (logP=3.35) and 2-ethyl-2-butylpropanediol di(meth)acrylate (logP=3.92); bis(meth)acrylates such as bis(meth)acrylates, ... Examples of the (meth)acrylates include aromatic ring-containing (meth)acrylates such as phenol A di(meth)acrylate (logP=5.46), bisphenol A ethylene oxide 4-mol adduct di(meth)acrylate (logP=5.15), bisphenol A propylene oxide 2-mol adduct di(meth)acrylate (logP=6.10), bisphenol A propylene oxide 4-mol adduct di(meth)acrylate (logP=6.43), 9,9-bis[4-(2-(meth)acryloyloxyethoxy)phenyl]fluorene (logP=7.48), and p-phenylphenol (meth)acrylate (logP=3.98).

[0100] When a polyfunctional radical polymerizable compound and a monofunctional radical polymerizable compound are used in combination, the content of the polyfunctional radical polymerizable compound is preferably 20 to 97% by weight, more preferably 50 to 95% by weight, further preferably 75 to 92% by weight, and particularly preferably 80 to 92% by weight, based on the total amount of the radical polymerizable compounds. If the content is within such a range, a polarizing film having excellent durability under high temperature and high humidity conditions can be obtained.

[0101] The monofunctional radically polymerizable compound may, for example, be a (meth)acrylamide derivative having a (meth)acrylamide group. By using the (meth)acrylamide derivative, a pressure-sensitive adhesive layer having excellent adhesive properties can be formed with high productivity. Specific examples of the (meth)acrylamide derivative include N-alkyl group-containing (meth)acrylamide derivatives such as N-methyl(meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, N-butyl(meth)acrylamide, and N-hexyl(meth)acrylamide; N-hydroxyalkyl group-containing (meth)acrylamide derivatives such as N-methylol(meth)acrylamide, N-hydroxyethyl(meth)acrylamide, and N-methylol-N-propane(meth)acrylamide; N-aminoalkyl group-containing (meth)acrylamide derivatives such as aminomethyl(meth)acrylamide and aminoethyl(meth)acrylamide; N-alkoxy group-containing (meth)acrylamide derivatives such as N-methoxymethylacrylamide and N-ethoxymethylacrylamide; and N-mercaptoalkyl group-containing (meth)acrylamide derivatives such as mercaptomethyl(meth)acrylamide and mercaptoethyl(meth)acrylamide. In addition, examples of heterocycle-containing (meth)acrylamide derivatives in which the nitrogen atom of the (meth)acrylamide group forms a heterocycle include N-acryloylmorpholine, N-acryloylpiperidine, N-methacryloylpiperidine, and N-acryloylpyrrolidine. Among these, N-hydroxyalkyl group-containing (meth)acrylamide derivatives are preferred, and N-hydroxyethyl(meth)acrylamide is more preferred.

[0102] In addition, examples of the monofunctional radical polymerizable compound that can be used include (meth)acrylic acid derivatives having a (meth)acryloyloxy group; carboxyl group-containing monomers such as (meth)acrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid; lactam-based vinyl monomers such as N-vinylpyrrolidone, N-vinyl-ε-caprolactam, and methylvinylpyrrolidone; and vinyl monomers having a nitrogen-containing heterocycle such as vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole, vinylimidazole, vinyloxazole, and vinylmorpholine.

[0103] When a polyfunctional radical polymerizable compound and a monofunctional radical polymerizable compound are used in combination, the content of the monofunctional radical polymerizable compound is preferably 3 to 80% by weight, more preferably 5 to 50% by weight, further preferably 8 to 25% by weight, and particularly preferably 8 to 20% by weight, based on the total amount of the radical polymerizable compounds. If the content is within such a range, a polarizing film having excellent durability under high temperature and high humidity conditions can be obtained.

[0104] The radical polymerization curing adhesive may further include other additives. When the radical polymerization curing adhesive includes a curable compound that is cured by active energy rays, the adhesive may further include, for example, a photopolymerization initiator, a photoacid generator, a silane coupling agent, etc. When the radical polymerization curing adhesive includes a curable compound that is cured by heat, the adhesive may further include a thermal polymerization initiator, a silane coupling agent, etc. Examples of other additives include polymerization inhibitors, polymerization initiator assistants, leveling agents, wettability improvers, surfactants, plasticizers, ultraviolet absorbers, inorganic fillers, pigments, dyes, etc.

[0105] (cationic polymerization curing adhesive) The cationic polymerization curing adhesive contains a cationic polymerizable compound as a curing compound. Examples of the cationic polymerizable compound include compounds having an epoxy group and / or an oxetanyl group. Compounds having an epoxy group that have at least two epoxy groups in the molecule are preferably used. Examples of compounds having an epoxy group include compounds having at least two epoxy groups and at least one aromatic ring (aromatic epoxy compounds), compounds having at least two epoxy groups in the molecule, at least one of which is formed between two adjacent carbon atoms constituting an alicyclic ring (alicyclic epoxy compounds), and the like.

[0106] The cationic polymerization curing adhesive preferably contains a photo-cationic polymerization initiator. The photo-cationic polymerization initiator generates cationic species or Lewis acid by irradiation with active energy rays such as visible light, ultraviolet light, X-rays, and electron beams, and initiates a polymerization reaction of the epoxy group or oxetanyl group. The cationic polymerization curing adhesive may further contain the additive.

[0107] (Water-based adhesive) As the aqueous adhesive, for example, an aqueous solution of an aqueous adhesive such as an isocyanate-based adhesive, a PVA-based adhesive, a gelatin-based adhesive, a vinyl-based latex-based adhesive, or a water-based polyester adhesive (for example, solid content concentration of 0.5 to 60% by weight) is suitably used.

[0108] The adhesive may be applied to the polarizing film 120, the polarizing film protective films 121 and 122, or other optical films, or to both of them. In general, a suitable method is to immerse the polarizing film in an aqueous solution of the adhesive, and then laminate the polarizing film protective films 121 and 122 with a roll laminator or the like. The thickness of the adhesive layer is not particularly limited, but is, for example, about 30 nm to 1000 nm after drying.

[0109] After the polarizing film, the polarizing film protective film, and other optical films are laminated via the adhesive, the laminate is subjected to a drying treatment. The drying process of the laminate is performed not only for the purpose of drying and solidifying the adhesive, but also for the purpose of reducing the moisture content to improve the initial optical properties of the polarizing film laminate. Heat drying is generally used as the drying method. The drying conditions are preferably in the range of 50 to 95°C, more preferably in the range of 60 to 85°C.

[0110] The drying conditions for the laminate are not particularly limited, but in consideration of the efficiency and practicality of the treatment, the drying temperature is preferably 50° C. or higher, and from the viewpoint of making the optical properties of the polarizing film laminate uniform, the drying temperature is preferably 95° C. or lower. The drying temperature can also be increased stepwise within the above temperature range.

[0111] The drying of the laminate can be carried out successively to the bonding treatment of the polarizing film, the polarizing film protective film, and other optical films. Alternatively, the laminate of the polarizing film, the polarizing film protective film, and other optical films may be once wound into a roll, and then dried as a separate treatment.

[0112] In general, high temperature and long drying conditions are required to reduce the moisture content of a polarizing film laminate. High temperature and long drying times are preferable from the viewpoint of reducing the moisture content of the polarizing film laminate, but on the other hand, they may lead to a deterioration in the optical properties, etc., of the polarizing film laminate. By using a polarizing film protective film with a low saturated water absorption amount or a polarizing film protective film with high moisture permeability, the moisture content of the polarizing film laminate can be adjusted to the desired range without adopting harsh drying conditions.

[0113] 2-5.Adhesive The adhesives described above in "1-3. Transparent adhesive" can be used in the same manner.

[0114] 3. Reliability evaluation items Several phenomena that may occur in polarizing film laminates, namely, polyenation, color loss, and red discoloration due to heat, are evaluated. Although the mechanism by which each phenomenon occurs is not entirely clear, it is assumed that it is roughly as follows.

[0115] <Polyenation> In a high temperature and high humidity environment, the single transmittance of the polarizing film laminate decreases. In addition, the single transmittance of the polarizing film laminate also decreases when exposed to light in the ultraviolet or visible light range. This decrease is presumed to be caused by the conversion of PVA to polyene. Polyenes are -(CH=CH) n -, which can be formed in the polarizing film by heating or light energy. Polyenes significantly reduce the transmittance of the polarizing film. In addition, PVA-polyiodine complexes are destroyed in high temperature and humidity environments and in environments exposed to ultraviolet and visible light, resulting in the formation of I - and I2 is likely to be produced. As shown in chemical formula 1 below, the polyenation of PVA is thought to occur when a dehydration reaction is promoted by iodine (I2) generated in a high-temperature, high-humidity environment or under irradiation with ultraviolet or visible light, together with heat and light energy. (chemical formula 1) JPEG2024164144000002.jpg40150 It is believed that when the PVA-polyiodine complex present in the polarizing film is broken down by heating or light energy, the generated I2 and the OH groups in the PVA form a charge-transfer complex (HO···I2), which then undergoes polyenation via the OI groups.

[0116] <Color loss> In iodine-dyed and stretched PVA-based films (polarizing films), iodine is I3 - and I5 - In the form of polyiodine ions, they form a complex with the oriented PVA (PVA polyiodine complex). At this time, crosslinking points are formed in the PVA by crosslinking agents such as boric acid, which allows the PVA to maintain its orientation. However, when the polarizing film is placed under high temperature and humidity, or under irradiation with ultraviolet or visible light, hydrolysis of the boric acid crosslink occurs, the orientation of the PVA decreases, and the PVA polyiodine complex collapses. This reduces the visible light absorption based on the PVA polyiodine complex, and increases the transmittance on the long wavelength side of about 700 nm and the short wavelength side of about 410 nm. Thus, when the polarizing film is placed under high temperature and humidity, or under irradiation with ultraviolet or visible light, color loss occurs in the black display.

[0117] <Heating red discoloration> In iodine-dyed and stretched PVA-based films (polarizing films), iodine is I3 - and I5 - It forms a complex with PVA in the form of polyiodine ion (PVA polyiodine complex). I3 - has a broad absorption peak around 470 nm, and I5 - has a broad absorption peak around 600 nm. - The complex is responsible for the absorption of the short wavelength side (blue side), and PVA-I5 - The complex is responsible for absorption on the longer wavelength side (red side). However, this PVA-I5 - The complex is sensitive to heat and light energy, and when the polarizing film is exposed to high temperatures or to ultraviolet or visible light, the PVA and I5 - The complex formation with I5 is broken. - will decompose. Therefore, in polarizing films placed under high temperatures or in an environment exposed to ultraviolet or visible light, PVA-I5, which is responsible for absorbing longer wavelengths, is - As the amount of the complex decreases, the transmittance on the long wavelength side of about 700 nm increases, causing the polarizing film to turn red.

[0118] 4. Examples and Comparative Examples Examples will be described below together with comparative examples, but the present invention is not limited to those described in these examples. As examples and comparative examples, the "thickness of the polarizing film (μm)" and / or the "iodine concentration of the polarizing film (wt.%)" and / or the "moisture content of the polarizing film laminate (g / m 2 ) and prepared samples of various polarizing film laminates with different "transmittance" for short wavelength light (380 μm, etc.).

[0119] <Thickness of polarizing film> The thickness (μm) of the polarizing film is measured using a spectroscopic film thickness meter MCPD-1000 (manufactured by Otsuka Electronics Co., Ltd.). The thickness of the polarizing film protective film is also measured using this. The polarizing film contained in the sample can be taken out by immersing the sample in a solvent and dissolving the polarizing film protective film. For example, the solvent can be dichloromethane when the polarizing film protective film is a triacetyl cellulose resin, cyclohexane when the polarizing film protective film is a cycloolefin resin, or methyl ethyl ketone when the polarizing film protective film is an acrylic resin. In addition, when the resin of the polarizing film protective film provided on one side of the polarizing film is different from the resin of the polarizing film protective film provided on the other side, each resin is dissolved in turn using the above-mentioned solvent.

[0120] <Iodine concentration in polarizing film> The iodine concentration (wt. %) of the polarizing film can be changed during production of the polarizing film, for example, by adjusting the concentration of the aqueous iodine solution in which the PVA film or PVA layer is immersed or the immersion time. The iodine concentration of the polarizing film is measured by the following method. The polarizing film contained in the sample can be taken out by immersing the sample in a solvent and dissolving the polarizing film protective film, in the same manner as in measuring the film thickness of the polarizing film. (X-ray fluorescence measurement) When measuring the iodine concentration of the polarizing film, the iodine concentration is first quantified using the calibration curve method of X-ray fluorescence analysis using a fluorescent X-ray analyzer ZSX-PRIMUS IV (manufactured by Rigaku Corporation). The value directly obtained by the X-ray fluorescence analyzer is not the concentration of each element, but the X-ray fluorescence intensity (kcps) of the wavelength specific to each element. Therefore, to obtain the iodine concentration in the polarizing film, it is necessary to convert the X-ray fluorescence intensity to the concentration using a calibration curve. In this specification, the iodine concentration of the polarizing film means the iodine concentration (wt%) based on the weight of the polarizing film.

[0121] (Creating a calibration curve) The calibration curve is prepared according to the following procedure. 1. Seven types of PVA solutions containing known concentrations of iodine were prepared by dissolving a known amount of potassium iodide in a PVA solution. These PVA solutions were applied to polyethylene terephthalate, dried, and then peeled off to prepare samples 1 to 7 of PVA films containing known concentrations of iodine. The iodine concentration (wt%) of the PVA film is calculated using the following formula 1. [Formula 1] Iodine concentration (wt%) = {amount of potassium iodide (g) / (amount of potassium iodide (g)+amount of PVA (g))} x (127 / 166) (Molecular weight of iodine: 127, molecular weight of potassium: 39)

[0122] 2. For the prepared PVA film, the fluorescent X-ray intensity (kcps) corresponding to iodine is measured using a fluorescent X-ray analyzer ZSX-PRIMUS IV (manufactured by Rigaku Corporation). The fluorescent X-ray intensity (kcps) is the peak value of the fluorescent X-ray spectrum. In addition, the film thickness of the prepared PVA film is measured using a spectroscopic film thickness meter MCPD-1000 (manufactured by Otsuka Electronics Co., Ltd.).

[0123] 3. The fluorescent X-ray intensity was divided by the thickness of the PVA film (μm) to obtain the fluorescent X-ray intensity per unit thickness of the film (kcps / μm). The iodine concentration and fluorescent X-ray intensity per unit thickness of each sample are shown in Table 1.

[0124] [Table 1]

[0125] 4. Based on the results shown in Table 1, a calibration curve is created with the fluorescent X-ray intensity (kcps / μm) per unit thickness of the PVA film on the horizontal axis and the iodine concentration (wt%) contained in the PVA film on the vertical axis. The created calibration curve is shown in Figure 4. The formula for calculating the iodine concentration from the fluorescent X-ray intensity per unit thickness of the PVA film using the calibration curve is determined as Equation 2. Note that R2 in Figure 4 is the correlation coefficient. [Formula 2] (Iodine concentration) (wt%) = 14.474 × (fluorescent X-ray intensity per unit thickness of PVA film) (kcps / μm)

[0126] (Calculation of iodine concentration) The fluorescent X-ray intensity obtained by measuring the sample is divided by the thickness to obtain the fluorescent X-ray intensity per unit thickness (kcps / μm). The fluorescent X-ray intensity per unit thickness of each sample is substituted into Equation 2 to obtain the iodine concentration.

[0127] <Moisture Content of Polarizing Film Laminate> Moisture content of polarizing film laminate (g / m 2 ) can be determined mainly by adjusting the film thickness of the polarizing film and the material and thickness of the polarizing film protective film bonded to the polarizing film. It can also be adjusted by crosslinking treatment (boric acid content, etc.) during the production of the polarizing film. The moisture content of the polarizing film laminate is measured by the following method. First, the polarizing film laminate obtained in each of the examples and comparative examples is cut into a square of 0.1 m×0.1 m. The cut sample is placed in a thermo-hygrostat and left for 48 hours in an environment with a temperature of 23°C and a relative humidity of 55%. After that, the sample is taken out in a clean room set to the same environment as inside the thermo-hygrostat, i.e., a temperature of 23°C and a relative humidity of 55%, and its weight is measured within 5 minutes after taking out. The weight of the sample at this time is defined as the initial weight W1 (g). Note that, within approximately 15 minutes after taking out, even if the temperature in the clean room fluctuates by about 2°C to 3°C and the relative humidity in the clean room fluctuates by about ±10%, there is no substantial effect on the initial weight. Next, the removed sample is placed in a dryer and dried at 120°C for 2 hours. After that, the dried sample is removed from the clean room set at a temperature of 23°C and a relative humidity of approximately 55% as described above, and its weight is measured within 10 minutes after removal. The weight of the sample at this time is taken as the post-drying weight W2 (g). Unlike the above, the reason for the period being within 10 minutes instead of within 5 minutes is to take cooling time into consideration. As with the above, if the sample is dried within approximately 15 minutes after removal, there is no substantial effect on the post-drying weight. From the initial weight W1 and the weight after drying W2 of the sample thus obtained, the equilibrium moisture content M (g / m 2 ) is calculated using the following formula. (Formula) M=(W1-W2) / (0.1×0.1) In the present invention, the "moisture content of the polarizing film laminate" means the equilibrium moisture content calculated by the above-mentioned method.

[0128] <Light absorption capacity> To evaluate the effect of suppressing the influence of short wavelength light, the transmittance of the polarizing film protective film located on the viewing side of the polarizing film was measured for each of the wavelengths of 380 μm, 390 μm, 400 μm, and 420 μm according to the JIS-Z-8701 color display method. The measurement was performed using Hitachi's U-4100.

[0129] [Example 1] (Creating a polarizing film) A long amorphous isophthalic copolymerized polyethylene terephthalate film (isophthalic acid group modification degree 5 mol%, thickness: 100 μm) was used as the resin substrate. (Modification degree = ethylene isophthalate unit / (ethylene terephthalate unit + ethylene isophthalate unit)) One side of the resin substrate was subjected to corona treatment (treatment conditions: 55 W·min / m2), and this corona-treated side was coated at room temperature with an aqueous solution of PVA (polymerization degree 4200, saponification degree 99.2 mol%) 90 parts by weight and acetoacetyl-modified PVA (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., product name "GOHSEFYMER Z410") 10 parts by weight, and potassium iodide was mixed at 13 parts by weight relative to the PVA. It was then dried at 60°C to form a PVA-based resin layer with a thickness of 13 μm, and a laminate was produced. The obtained laminate was uniaxially stretched at its free end to 2.4 times its original size in the machine direction (longitudinal direction) between rolls with different peripheral speeds in an oven at 130° C. (auxiliary air stretching). Next, the laminate was immersed in an insolubilizing bath (a boric acid aqueous solution obtained by mixing 4 parts by weight of boric acid with 100 parts by weight of water) at a liquid temperature of 40° C. for 30 seconds (insolubilizing treatment). Next, the fabric was immersed in a dye bath (an aqueous iodine solution obtained by mixing iodine and potassium iodide in a weight ratio of 1:7 with 100 parts by weight of water) at a liquid temperature of 30°C for 60 seconds while adjusting the concentration to obtain the specified transmittance (dyeing process). Next, the piece was immersed in a crosslinking bath (a boric acid aqueous solution obtained by mixing 3 parts by weight of potassium iodide and 5 parts by weight of boric acid with respect to 100 parts by weight of water) at a liquid temperature of 40° C. for 30 seconds (crosslinking treatment). Thereafter, the laminate was immersed in an aqueous boric acid solution (boric acid concentration: 3.0% by weight) at a liquid temperature of 70°C and uniaxially stretched in the longitudinal direction (longitudinal direction) between rolls with different peripheral speeds to a total stretch ratio of 5.5 times (underwater stretching). Thereafter, the laminate was immersed in a cleaning bath (an aqueous solution obtained by mixing 4 parts by weight of potassium iodide with 100 parts by weight of water) at a liquid temperature of 20° C. (cleaning treatment). Thereafter, the coated film was dried in an oven maintained at 90° C. (drying treatment) while being brought into contact with a SUS metal roll whose surface temperature was maintained at 75° C. for 2 seconds or more (hot roll drying treatment). In this manner, a polarizing film having a thickness of 5.4 μm was obtained on the resin substrate.

[0130] (Creation of polarizing film laminate) A polarizing film protective film was not provided on the surface of the obtained polarizing film opposite to the resin substrate (one surface of the polarizing film, in other words, the surface opposite to the viewing side of the polarizing film), while a polarizing film protective film having light absorption ability, consisting of a triacetyl cellulose film (manufactured by Konica Minolta, product name "KC4UY", thickness 40 μm) containing a light absorbent and a hard coat layer (thickness 5 μm) containing a light absorbent arranged on the viewing side, was bonded to the surface of the obtained polarizing film from which the resin substrate was peeled off (the other surface of the polarizing film, in other words, the surface on the viewing side of the polarizing film) via an ultraviolet curing adhesive described later. Specifically, the curing adhesive was applied so that the total thickness of the curing adhesive was 1.0 μm, and the adhesive was bonded using a rolling machine. Thereafter, UV rays were irradiated from the other surface side to cure the adhesive, and a polarizing film laminate including a polarizing film and a polarizing film protective film having light absorption ability on the other surface of the polarizing film was obtained. The above-mentioned triacetyl cellulose film contains a predetermined amount of a light absorber (ultraviolet absorbing agent). On the other hand, the hard coat layer contains a light absorber, Tinosorb S (manufactured by BASF), so that the triacetyl cellulose film and the hard coat layer as a whole have a transmittance as shown in the absorption capacity in Tables 2 and 3 described below. Details of the UV-curable adhesive are as follows. An adhesive was prepared by mixing 40 parts by weight of N-hydroxyethylacrylamide (HEAA), 60 parts by weight of acryloylmorpholine (ACMO), and 3 parts by weight of a photoinitiator "IRGACURE 819" (manufactured by BASF). The adhesive was applied onto a polarizing film so that the adhesive layer would be 1.0 μm thick after curing, and the adhesive was cured by irradiating it with UV rays as active energy rays. UV irradiation was performed using a gallium-filled metal halide lamp, irradiation device: Light HAMMER10 manufactured by Fusion UV Systems, Inc., bulb: V bulb, peak irradiance: 1600 mW / cm. 2 , cumulative dose 1000 / mJ / cm 2(wavelength 380-440 nm) was used, and the UV irradiance was measured using a Sola-Check system manufactured by Solatell.

[0131] (Measurement of iodine concentration) The polarizing film was taken out of the polarizing film laminate using cyclohexane as a solvent, and the iodine concentration of the polarizing film was measured.

[0132] (Transmittance measurement) The polarizing film protective film located on the viewing side of the polarizing film, that is, the polarizing film protective film consisting of the triacetyl cellulose film and the hard coat layer, was peeled off from the polarizing film laminate, and the transmittance of the polarizing film protective film was measured.

[0133] [Example 2] When the polarizing film of Example 1 was produced, the iodine concentration was changed by adjusting the concentration of the iodine aqueous solution and the immersion time in the dyeing treatment. In addition, when preparing the polarizing film laminate of Example 1, a cycloolefin film (ZEONORFILM, 13 μm, manufactured by ZEON CORPORATION) was bonded to one side of the polarizing film as a polarizing film protective film via an ultraviolet-curable adhesive. Since this cycloolefin film is provided on one side of the polarizing film, it does not affect the value of the light absorption ability. Meanwhile, the other side of the polarizing film had the same configuration as the other side of Example 1. In addition, the moisture content of the polarizing film laminate was changed. The rest is the same as in the first embodiment.

[0134] [Comparative Example 1] In producing the polarizing film laminate of Example 1, one side of the polarizing film had the same configuration as that of the one side of Example 1, while a 20 μm-thick transparent protective film (manufactured by Nitto Denko Corporation) made of a modified acrylic polymer having a lactone ring structure was bonded to the other side of the polarizing film via an ultraviolet-curable adhesive so that the total thickness of the curable adhesive was 1.0 μm in the same manner as in Example 1. In addition, the moisture content of the polarizing film laminate was changed. The rest is the same as in the first embodiment.

[0135] [Comparative Example 2] In producing the polarizing film laminate of Example 2, one side of the polarizing film had the same configuration as that of the one side of Example 2, while a cycloolefin film (ZEON Corporation, Zeonorfilm, 25 μm) was bonded to the other side of the polarizing film via an ultraviolet-curable adhesive so that the total thickness of the curable adhesive was 1.0 μm in the same manner as in Example 1. In addition, the moisture content of the polarizing film laminate was changed. The rest is the same as in the second embodiment.

[0136] [Comparative Example 3] When the polarizing film of Example 1 was produced, the iodine concentration was changed by adjusting the concentration of the iodine aqueous solution and the immersion time in the dyeing treatment. In producing the polarizing film laminate of Example 1, a cycloolefin film (ZEONORFILM, 17 μm, manufactured by ZEON CORPORATION) was bonded as a polarizing film protective film to one side of the polarizing film via an ultraviolet-curable adhesive so that the total thickness of the curable adhesive was 1.0 μm in the same manner as in Example 1. Meanwhile, the other side of the polarizing film had the same configuration as the other side of Example 1. Furthermore, the moisture content of the polarizing film laminate was changed. The rest is the same as in the first embodiment.

[0137] [Comparative Example 4] In producing the polarizing film laminate of Comparative Example 3, one side of the polarizing film had the same structure as that of the one side of Comparative Example 3. On the other hand, no polarizing film protective film was provided on the other side of the polarizing film. In addition, the moisture content of the polarizing film laminate was changed. The rest is the same as in Comparative Example 3.

[0138] [Example 3] (Creating a polarizing film) A PVA film with an average degree of polymerization of 2700 and a thickness of 30 μm was dyed and stretched between rolls with different peripheral speed ratios. First, the PVA film was immersed in a water bath at 30° C. for 1 minute to swell and stretched 1.2 times in the transport direction, and then immersed in an aqueous solution (liquid temperature 30° C.) of potassium iodide (0.03 wt %) and iodine (0.3 wt %) for 1 minute to stretch 3 times (based on unstretched film) in the transport direction while dyeing. Next, this stretched film was immersed in an aqueous solution (bath liquid) of boric acid (4 wt %) and potassium iodide (5 wt %) for 30 seconds to stretch 6 times (based on unstretched film) in the transport direction. After stretching, the film was dried in an oven at 40° C. for 3 minutes to obtain a polarizing film with a thickness of 12.0 μm.

[0139] (Creation of polarizing film laminate) As the adhesive, a doped curing adhesive was used, more specifically, an aqueous solution containing a polyvinyl alcohol resin (average polymerization degree 1200, saponification degree 98.5 mol%, acetoacetylation degree 5 mol%) containing an acetoacetyl group and methylol melamine in a weight ratio of 3:1. Using this adhesive, a transparent protective film (manufactured by Nitto Denko Corporation) having a thickness of 20 μm and made of a modified acrylic polymer having a lactone ring structure was bonded to one side of the polarizing film under a temperature condition of 30° C. Specifically, the doped curing adhesive was applied so that the total thickness of the doped curing adhesive became 1.0 μm, and the film was bonded using a rolling machine. On the other hand, the polarizing film protective film having light absorption ability, that is, the polarizing film protective film used in Example 1, that is, the polarizing film protective film consisting of a triacetyl cellulose film containing a light absorbent and a hard coat layer containing a light absorbent arranged on the viewing side of the doped curing adhesive, was bonded to the other side of the polarizing film using the same doped curing adhesive in the same manner as the one side, instead of using an ultraviolet curing adhesive. The film was then heated and dried in an oven at 70°C for 5 minutes to obtain a polarizing film laminate having a polarizing film protective film that does not absorb light on one side of the polarizing film and a polarizing film protective film that has light absorption on the other side. (Measurement of iodine concentration) The polarizing film was removed from the polarizing film laminate using dichloromethane and methyl ethyl ketone as a solvent, and the iodine concentration of the polarizing film was measured.

[0140] (Transmittance measurement) The transmittance was measured in the same manner as in Example 1.

[0141] [Comparative Example 5] In preparing the polarizing film laminate of Example 3, the one surface was made to have the same structure as that of Example 3, and a polarizing film protective film having a light absorbing ability, which is composed of a triacetyl cellulose film (manufactured by Konica Minolta, product name "KC2UA", thickness 25 μm) containing a light absorbent and a hard coat layer (manufactured by Nitto Denko Corporation, thickness 9 μm) having no light absorbing ability arranged on the viewing side, was bonded to the other surface by the same method as that of Example 3 via a doped curing adhesive so that the total thickness of the curing adhesive was 1.0 μm. In addition, the moisture content of the polarizing film laminate was changed. The hard coat layer was formed by the following method. First, a hard coat layer forming material is prepared. This is prepared by adding 5 parts by weight of a photopolymerization initiator (BASF, product name "IRGACURE906") and 0.01 parts by weight of a leveling agent (DIC, product name "GRANDIC PC4100") per 100 parts by weight of the solid content in the solution to a resin solution (DIC, product name "UNIDIC 17-806", solid content concentration 80% by weight) in which an ultraviolet-curable resin monomer or oligomer mainly composed of urethane acrylate is dissolved in butyl acetate, and adding cyclopentanone (hereinafter referred to as "CPN") and propylene glycol monomethyl ether (hereinafter referred to as "PGM") in a ratio of 45:55 to the above blended liquid so that the solid content concentration in the above solution becomes 36% by weight. The hard coat layer forming material prepared in this way was applied onto a transparent protective film to form a coating film so that the thickness of the hard coat after curing becomes 9 μm. Next, the coating was dried at 90° C. for 1 minute, and then irradiated with ultraviolet light from a high-pressure mercury lamp at an integrated light intensity of 300 mJ / cm 2 to cure the coating. The rest is the same as in the third embodiment.

[0142] [Example 4] (Creating a polarizing film) A PVA film with an average degree of polymerization of 2700 and a thickness of 45 μm was stretched and conveyed between rolls with different peripheral speed ratios while being dyed. First, the PVA film was immersed in a water bath at 30° C. for 1 minute to swell and stretched 1.2 times in the conveying direction, and then immersed in an aqueous solution (liquid temperature 30° C.) of potassium iodide (0.03 wt%) and iodine (0.3 wt%) for 1 minute to stretch 3 times (based on unstretched film) in the conveying direction while being dyed. Next, this stretched film was stretched 6 times (based on unstretched film) in the conveying direction while being immersed in an aqueous solution (bath liquid) of boric acid (4 wt%), potassium iodide (5 wt%) and zinc sulfate (3.5 wt%) for 30 seconds. After stretching, the film was dried in an oven at 40° C. for 3 minutes to obtain a polarizing film with a thickness of 18.0 μm. (Creation of polarizing film laminate) A 30 μm-thick transparent protective film (manufactured by Nitto Denko Corporation) made of a modified acrylic polymer having a lactone ring structure was bonded to one surface of the polarizing film via a dope-curing adhesive in the same manner as in Example 3. Meanwhile, the other surface of the polarizing film had the same configuration as the other surface of Example 3. The rest is the same as in the third embodiment.

[0143] [Example 5] In preparing the polarizing film laminate of Example 4, the one surface had the same configuration as in Example 4, and a polarizing film protective film having light absorption ability was bonded to the other surface via a doped curable adhesive in the same manner as in Example 3, the polarizing film protective film being composed of a triacetyl cellulose film containing a light absorber (manufactured by Fujifilm Corporation, product name "TJ40ULF", thickness 40 μm), a triacetyl cellulose film containing a light absorber (manufactured by Konica Minolta, product name "KC4UY", thickness 40 μm) placed on the viewing side thereof, and a hard coat layer not having light absorption ability (manufactured by Nitto Denko Corporation, thickness 9 μm) placed on the viewing side thereof, so that the total thickness of the curable adhesive was 1.0 μm. A triacetyl cellulose film (manufactured by Fujifilm Corporation, product name "TJ40ULF", thickness 40 μm) and a triacetyl cellulose film (manufactured by Konica Minolta, product name "KC4UY", thickness 40 μm) were bonded together via an ultraviolet-curing adhesive in the same manner as in Example 1 so that the total thickness of the curing adhesive was 1.0 μm. (Measurement of iodine concentration) The polarizing film was removed from the polarizing film laminate using dichloromethane and methyl ethyl ketone as a solvent, and the iodine concentration of the polarizing film was measured.

[0144] (Transmittance measurement) The polarizing film protective film located on the viewing side of the polarizing film, i.e., a polarizing film protective film consisting of a triacetyl cellulose film, another triacetyl cellulose film, and a hard coat layer, was peeled off from the polarizing film laminate, and the transmittance of the polarizing film protective film was measured.

[0145] [Comparative Example 6] In preparing the polarizing film laminate of Example 4, a transparent protective film (manufactured by Nitto Denko Corporation) having a thickness of 30 μm and made of a modified acrylic polymer having a lactone ring structure was bonded to one surface of the polarizing film via a doped curing adhesive in the same manner as in Example 3. On the other hand, a polarizing film protective film having a light absorbing ability, which was a triacetyl cellulose film (manufactured by Fuji Film Corporation, product name "TJ40ULF", thickness 40 μm) containing a light absorbent and a hard coat layer (manufactured by Nitto Denko Corporation, thickness 9 μm) having no light absorbing ability, was bonded to the other surface of the polarizing film via a doped curing adhesive in the same manner as in Example 3 so that the total thickness of the curing adhesive was 1.0 μm. In addition, the moisture content of the polarizing film laminate was changed. The rest is the same as in the fourth embodiment.

[0146] [Comparative Example 7] When producing the polarizing film laminate of Comparative Example 6, the iodine concentration was changed by adjusting the concentration of the iodine aqueous solution and the immersion time in the dyeing treatment. Also, the water content of the polarizing film laminate was changed. The rest is the same as in Comparative Example 6.

[0147] [Comparative Example 8] In producing the polarizing film laminate of Example 4, the iodine concentration was changed by adjusting the concentration of the iodine aqueous solution and the immersion time in the dyeing treatment. Also, the water content of the polarizing film laminate was changed. The rest is the same as in the fourth embodiment.

[0148] [Example 6] In producing the polarizing film laminate of Example 4, the iodine concentration was changed by adjusting the concentration of the iodine aqueous solution and the immersion time in the dyeing treatment. Also, the water content of the polarizing film laminate was changed. The rest is the same as in the fourth embodiment.

[0149] [Example 7] (Creating a polarizing film) In the preparation of the polarizing film of Example 3, a 75 μm-thick PVA film was stretched and conveyed to obtain a 28 μm-thick polarizing film in the stretching process. In the dyeing process, the iodine concentration was changed by adjusting the concentration of the iodine aqueous solution and the immersion time. (Creation of polarizing film laminate) One side and the other side of the polarizing film had the same configuration as the one side and the other side of the polarizing film in Example 4. In addition, the moisture content of the polarizing film laminate was changed. The rest is the same as in the fourth embodiment.

[0150] [Example 8] The water content of the polarizing film laminate was changed when producing the polarizing film laminate of Example 7. In Example 7, similarly to Example 4, the film was immersed in an aqueous solution (bath liquid) of zinc sulfate (3.5 wt %) when stretched 6 times (based on the unstretched film) in the conveying direction. The other conditions were the same as those in Example 7.

[0151] [Comparative Example 9] (Creating a polarizing film) The polarizing film of Example 7 was used. (Creation of polarizing film laminate) One surface of the polarizing film had the same structure as that of the one surface of the polarizing film in Examples 4 to 8 and Comparative Example 8. On the other hand, a polarizing film protective film having the same structure as that of the other surface of the polarizing film in Comparative Example 5, that is, a polarizing film protective film having light absorbing ability, which was composed of a triacetyl cellulose film containing a light absorbent and a hard coat layer not having light absorbing ability arranged on the viewing side thereof, was bonded to the other surface of the polarizing film via a doped curing adhesive in the same manner as in Example 3 so that the total thickness of the curing adhesive became 1.0 μm. In addition, the moisture content of the polarizing film laminate was changed. The other conditions were the same as those in Example 7.

[0152] [Example 9] When the polarizing film of Example 4 was produced, the iodine concentration was changed by adjusting the concentration of the iodine aqueous solution and the immersion time in the dyeing treatment. The rest is the same as in the fourth embodiment.

[0153] [Example 10] When the polarizing film of Example 3 was produced, the iodine concentration was changed by adjusting the concentration of the iodine aqueous solution and the immersion time in the dyeing treatment. In addition, when preparing the polarizing film laminate of Example 3, a 30 μm-thick transparent protective film (manufactured by Nitto Denko Corporation) was used as the transparent protective film made of a modified acrylic polymer having a lactone ring structure and bonded to one side of the polarizing film, instead of a 20 μm-thick transparent protective film. Furthermore, the moisture content of the polarizing film laminate was changed. The rest is the same as in the third embodiment.

[0154] [Comparative Example 10] When preparing the polarizing film of Example 9, the concentration of the iodine solution and the immersion time were adjusted in the dyeing treatment to change the iodine concentration. In preparing the polarizing film laminate of Example 9, a transparent protective film (manufactured by Nitto Denko Corporation) having a thickness of 30 μm and made of a modified acrylic polymer having a lactone ring structure was bonded to one surface of the polarizing film via a doped curing adhesive in the same manner as in Example 3. On the other hand, a polarizing film protective film having a light absorbing ability, which was a triacetyl cellulose film (manufactured by Fuji Film Corporation, product name "TJ40ULF", thickness 40 μm) containing a light absorbent and a hard coat layer (manufactured by Nitto Denko Corporation, thickness 9 μm) having no light absorbing ability, was bonded to the other surface of the polarizing film via a doped curing adhesive in the same manner as in Example 3 so that the total thickness of the curing adhesive was 1.0 μm. In addition, the moisture content of the polarizing film laminate was changed. The rest is the same as in Example 9.

[0155] [Example 11] When the polarizing film of Example 3 was produced, the iodine concentration was changed by adjusting the concentration of the iodine aqueous solution and the immersion time in the dyeing treatment. In addition, when preparing the polarizing film laminate of Example 3, a doped curing adhesive was used as the adhesive, more specifically, an aqueous solution containing a polyvinyl alcohol resin (average polymerization degree 1200, saponification degree 98.5 mol%, acetoacetylation degree 5 mol%) containing an acetoacetyl group and methylol melamine in a weight ratio of 3:1. A transparent protective film made of triacetyl cellulose and having a thickness of 25 μm was bonded to one side of the polarizing film using this adhesive. Specifically, the doped curing adhesive was applied so that the total thickness of the doped curing adhesive became 1.0 μm, and the film was bonded using a rolling machine. On the other hand, the polarizing film protective film having a light absorbing ability, that is, the polarizing film protective film used in Example 1, that is, the polarizing film protective film made of a triacetyl cellulose film containing a light absorbent and a hard coat layer containing a light absorbent arranged on the viewing side of the doped curing adhesive, was bonded to the other side of the polarizing film using the same method as that for the one side, instead of using an ultraviolet curing adhesive. The film was then heated and dried in an oven at 70°C for 5 minutes to obtain a polarizing film laminate having a polarizing film protective film that does not absorb light on one side of the polarizing film and a polarizing film protective film that has light absorption on the other side.

[0156] [Comparative Example 11] In preparing the polarizing film laminate of Example 11, a doped curing adhesive was used as the adhesive, more specifically, an aqueous solution containing a polyvinyl alcohol resin (average polymerization degree 1200, saponification degree 98.5 mol%, acetoacetylation degree 5 mol%) containing an acetoacetyl group and methylol melamine in a weight ratio of 3:1. A transparent protective film made of triacetyl cellulose and having a thickness of 25 μm was bonded to one side of the polarizing film using this adhesive. Specifically, the doped curing adhesive was applied so that the total thickness of the adhesive became 1.0 μm, and the film was bonded using a rolling machine. On the other hand, the polarizing film protective film having a light absorbing ability, that is, the polarizing film protective film used in Comparative Example 5, that is, the polarizing film protective film made of a triacetyl cellulose film containing a light absorbent and a hard coat layer not containing a light absorbent arranged on the viewing side of the triacetyl cellulose film, was bonded to the other side of the polarizing film using the same doped curing adhesive in the same manner as the one side, instead of the ultraviolet curing adhesive.

[0157] [Comparative Example 12] When preparing the polarizing film of Example 11, the iodine concentration was changed by adjusting the concentration of the iodine aqueous solution and the immersion time in the dyeing treatment. The rest is the same as in Example 11.

[0158] [Comparative Example 13] When preparing the polarizing film of Comparative Example 11, the concentration of iodine in the dyeing treatment was changed by adjusting the concentration of the iodine aqueous solution and the immersion time. The rest is the same as in Comparative Example 11.

[0159] 4-1. Reliability testing The polarizing film laminate 12 obtained in the Examples and Comparative Examples was used to prepare a sample, in which glass plates (Matsunami Glass slide glass, product number: S2000423, specifications: water-polished edge, 65 × 165 mm, thickness 1.3 mm) were laminated on both sides of the polarizing film laminate 12 via transparent adhesives 11 and 13, as shown in Figure 5.

[0160] As the adhesive, CS98210US (manufactured by Nitto Denko Corporation) with a thickness of 200 μm was used on one side of the polarizing film laminate, and an acrylic adhesive (thickness of 20 μm) used in the polarizing film laminate of CRT1794YCU (manufactured by Nitto Denko Corporation) was used on the other side of the polarizing film laminate. The acrylic adhesive used on the other side was obtained by adding 99 parts by weight (hereinafter the same) of butyl acrylate, 1.0 part of 4-hydroxybutyl acrylate, and 0.3 parts of 2,2'-azobisisobutyronitrile together with ethyl acetate to a reaction vessel equipped with a cooling tube, nitrogen inlet tube, thermometer, and stirrer, and reacting them at 60° for 4 hours under a nitrogen gas stream, and then adding ethyl acetate to the reaction liquid to obtain a solution containing an acrylic polymer with a weight average molecular weight of 1.65 million (solids concentration 30% by weight), and blending 0.3 parts of dibenzoyl peroxide (Niper BMT, manufactured by Nippon Oil & Fats Co., Ltd.), 0.1 parts of trimethylolpropane xylene diisocyanate (Takenate D110N, manufactured by Mitsui Takeda Chemical Co., Ltd.), and 0.2 parts of silane coupling agent (A-100, acetoacetyl group-containing silane coupling agent, manufactured by Midoriken Chemical Co., Ltd.) per 100 parts of solids of this acrylic polymer solution.

[0161] A xenon light irradiation test was carried out on each sample using a xenon weather meter (NX75 manufactured by Suga Test Instruments Co., Ltd.). (Xenon light irradiation test) The sample was exposed to xenon light in the wavelength range of 300 to 400 nm at an integrated irradiance of 100 W / m2 under an atmosphere of black panel temperature of 89°C and 30% RH. 2 The sample was irradiated with light for 200 hours. A xenon lamp (manufactured by Suga Test Instruments Co., Ltd.) equipped with a daylight filter (manufactured by Suga Test Instruments Co., Ltd.) was used as the light source. After 200 hours of irradiation, the color loss and reddening due to heat were evaluated, and after 200 hours of irradiation, the polyenation was evaluated.

[0162] Evaluation criteria The evaluation criteria for polyenation, reddening on heating, and color loss are shown below.

[0163] <Polyenation> The single-piece transmittance of the sample was measured before and after the xenon light irradiation test, and the change in single-piece transmittance, ΔTs, was calculated using the following formula. (Formula) ΔTs = Ts xenon 200 - Ts0 Here, Ts0 is the single unit transmittance of the sample before xenon irradiation, and TsXenon200 is the single unit transmittance after the xenon light irradiation test. When the single unit transmittance after 200 hours of xenon light irradiation was -0.5 or more compared to the single unit transmittance before xenon light irradiation, the problem of polyenization was evaluated as being within the acceptable range and not a problem. When the single unit transmittance after 200 hours of xenon light irradiation was -0.2 or more compared to the single unit transmittance before xenon light irradiation, the problem of polyenization was evaluated as being even less of a problem. Furthermore, when the single unit transmittance after 200 hours of xenon light irradiation was the same as or greater than the single unit transmittance before xenon light irradiation, the problem of polyenization was evaluated as being even less of a problem. The single transmittance of the above sample was measured using a spectrophotometer (product name "DOT-3" manufactured by Murakami Color Research Laboratory Co., Ltd.) The single transmittance can be determined in accordance with JIS Z 8701.

[0164] <Color loss / reddening due to heat> Before and after the xenon light irradiation test, the sample was placed in a crossed Nicol position and the cross transmittance (%) at wavelengths of 410 nm and 700 nm was measured using the above spectrophotometer. 410 and ΔHs 700 asked for. A sample that met both of the following two conditions was evaluated as having "color loss." Change ΔHs 410 More than 1% Change ΔHs 700 More than 5% In other words, if the change in cross transmittance at a wavelength of 410 nm after irradiation with xenon light for 200 hours is less than 1% and the change in cross transmittance at a wavelength of 700 nm is less than 5%, it is determined that there is no problem with color loss. Moreover, samples that met the following conditions were evaluated as "reddened by heating." Change ΔHs410 Less than 1% Change ΔHs 700 More than 5% In other words, if the change in cross transmittance at a wavelength of 410 nm after irradiation with xenon light for 200 hours is 1% or more and the change in cross transmittance at a wavelength of 700 nm is less than 5%, it is determined that there is no problem with reddening due to heating.

[0165] The evaluation results for each of the Examples and Comparative Examples are shown in Tables 2 and 3 below.

[0166] [Table 2]

[0167] [Table 3]

[0168] 5. Summary of evaluation results FIG. 6 is a plot of the results of the Examples and Comparative Examples in an xy Cartesian coordinate system with the Examples at the center, and more specifically, when the results of the Examples and Comparative Examples overlap, the results of the "Examples" are shown. Conversely, FIG. 7 is a plot of the results of the Examples and Comparative Examples with the Comparative Examples at the center, and more specifically, when the results of the Examples and Comparative Examples overlap, the results of the "Comparative Examples" are shown. The x-axis (horizontal axis) represents the iodine concentration (wt.%) of the polarizing film, and the y-axis (vertical axis) represents the moisture content (g / m 2 ) respectively.

[0169] (1) From the plotted results and technical common sense, it can be said that, in general, when the iodine concentration is low and the moisture content is too low, the problem of heat reddening occurring in high temperature conditions is likely to occur, while when the iodine concentration is high and the moisture content is too high, the problem of polyenation and color loss is likely to occur. Also, when the iodine concentration is low and the moisture content is too high, the problem of color loss occurring in high temperature and high humidity conditions is likely to occur, and in this case, as the iodine concentration increases, the problem of polyenation is likely to occur. In particular, a transitional region (Comparative Example 1) between color loss and polyenation was also found. Although the results of heat reddening are not particularly shown in Figure 6, it can be said that it is clear from technical common sense that this phenomenon occurs when the iodine concentration is low and the moisture content is too low. On the other hand, when the iodine concentration and the moisture content are neither too high nor too low, but are in a balanced state, and therefore when the iodine concentration and the moisture content are within a predetermined range where such a balance can be achieved, it can be seen that all of the problems of reddening due to heating, polyenation, and color loss can be comprehensively solved. For example, all of the results of the Examples are around the plot showing the results of Example 2, which has a small moisture content but a large iodine concentration, that is, an iodine concentration of 6.0 wt.% and a moisture content of 0.7 g / m 2 (hereinafter, the first coordinate point) and the periphery of the plot showing the results of Example 7, which has the lowest iodine concentration but the highest water content, i.e., an iodine concentration of 1.8 wt.% and a water content of 4.2 g / m 2 The area around the plot showing the results of Example 6, which has the highest water content but the lowest iodine concentration, i.e., the area around the partition line "α" passing through the coordinate point (hereinafter, the second coordinate point) of Example 6, i.e., the area around the plot showing the results of Example 6, which has the highest water content but the lowest iodine concentration ... 2 (hereinafter, the third coordinate point) and the periphery of the plot showing the results of Example 1, which has the highest iodine concentration but the lowest water content, i.e., an iodine concentration of 7.0 wt.% and a water content of 0.7 g / m 2The third coordinate point is located below the dividing line "β" that passes through the coordinate point (hereinafter referred to as the fifth coordinate point) of 344.4-44x / 52, i.e., y=(344.4-44x) / 52. Therefore, at least the area divided by these dividing lines "α" and "β" can be regarded as a line indicating the requirements necessary to comprehensively solve all of the problems of reddening due to heating, polyenation, and color loss. Furthermore, taking into consideration the results of the comparative example, the coordinate points that can be connected to each of the third coordinate point and the fifth coordinate point without including the comparative example, i.e., iodine concentration of 5.7 wt.% and moisture content of 2.6 g / m 2 (hereinafter, the fourth coordinate point) can also be considered. That is, all the results of the examples are positioned below the partition line "γ1" passing through the third and fourth coordinate points, i.e., y=(243.9-25x) / 39, and below the partition line "γ2" passing through the fourth and fifth coordinate points, i.e., y=(142.1-19x) / 13. Note that these partition lines "α", "β", "γ1" and "γ2" are applicable regardless of the thickness of the polarizing film, and more specifically, to all polarizing films having a thickness of about 4 to 30 μm.

[0170] (2) From these facts, it was found that, for all polarizing films having a thickness of about 4 to 30 μm, the iodine concentration and the moisture content of the polarizing film laminate were, for example, within the range surrounded by a to e, more specifically, the iodine concentration of 6.0 wt.% and the moisture content of 0.7 g / m 2 The first coordinate point ("a" in the figure) and the iodine concentration of 1.8 wt.% and the water content of 4.2 g / m 2 The first line segment connecting the second coordinate point ("b" in the figure) of the first coordinate point "b" and the second coordinate point "b" of the second coordinate point "b" of the first ... 2 The second line segment connecting the third coordinate point ("c" in the figure) of the iodine concentration of 5.7 wt.% and the water content of 2.6 g / m 2 The third line segment connecting the fourth coordinate point ("d" in the figure) of the iodine concentration of 7.0 wt.% and the water content of 0.7 g / m 2It can be seen that when the color of the resin composition is contained within the area surrounded by the fourth line segment connecting the first coordinate point "a" and the fifth coordinate point "e" (in the figure), and the fifth line segment connecting the first coordinate point "a" and the fifth coordinate point "e", all of the problems of "polyenation", "color loss", and "reddening on heating" can be comprehensively solved.

[0171] (3) Similarly, for a polarizing film having a thickness of about 11 to 30 μm, the iodine concentration and the moisture content of the polarizing film laminate are within the region surrounded by f, b, c, and g, more specifically, the iodine concentration is 4.5 wt.% and the moisture content is 1.9 g / m 2 The sixth line segment connecting the sixth coordinate point ("f" in the figure) and the second coordinate point "b", the second line segment connecting the second coordinate point "b" and the third coordinate point "c", the third line segment connecting the third coordinate point "c" and the iodine concentration of 4.5 wt.% and the moisture content of 3.4 g / m 2 It can be seen that when the color of the resin composition is contained within the area surrounded by the seventh line segment connecting the sixth coordinate point "f" and the seventh coordinate point "g" ("g" in the figure), and the eighth line segment connecting the sixth coordinate point "f" and the seventh coordinate point "g", all of the problems of "polyenation", "color loss", and "reddening upon heating" can be comprehensively solved. In particular, the sixth coordinate point "f" has an iodine concentration of 4.0 wt.% and a water content of 2.4 g / m 2 The eighth coordinate point ("f-1" in the figure) of the sample is the iodine concentration of 4.0 wt.% and the water content of 3.7 g / m 2 It is believed that favorable results will be obtained when the ninth coordinate point ("g-1" in the figure) is the iodine concentration of 3.7 wt.% and the water content of 2.6 g / m 2 It is believed that favorable results will also be obtained if the tenth coordinate point ("h" in the figure) and the seventh coordinate point "g" is the fourth coordinate point "d."

[0172] (4) Furthermore, in particular for polarizing films having a thickness of about 4 to 11 μm, when the iodine concentration and the moisture content of the polarizing film laminate are included in the area surrounded by a, h, d, and e, more specifically, the area surrounded by the ninth line segment connecting the first coordinate point "a" and the tenth coordinate point "h", the eleventh line segment connecting the tenth coordinate point "h" and the fourth coordinate point "d", and the fifth line segment connecting the first coordinate point "a" and the fifth coordinate point "e", it can be found that all of the problems "polyenization", "color loss", and "reddening upon heating" can be comprehensively solved.

[0173] Furthermore, as is clear from a comparison between FIG. 6 and FIG. 7, by providing a light absorbing layer having a light absorbing ability, it is found that, in particular, polyenation is effectively prevented.

[0174] In the above embodiment, a light absorbent is added to the polarizing film protective film. However, the same results are obtained when the above reliability test is performed by adding a light absorbent (ultraviolet ray absorbent) to the transparent adhesive (OCA) 13 (transparent adhesive layer). The same results are obtained when the above reliability test is performed by adding a light absorbent (ultraviolet ray absorbent) to the cover plate 14 (transparent cover plate). In this case, the reliability test is performed using the cover plate 14 instead of a glass plate (Matsunami Glass Slide Glass, Product No. S2000423, Specifications: Water Edge Polished 65×165 mm, Thickness 1.3 mm) on the viewing side of the transparent adhesive 13. [Explanation of symbols]

[0175] 1 Optical display panel 10 Optical display cell 11 Transparent adhesive 12 Polarizing film laminate 13 Transparent adhesive 14 Transparent cover plate 120 Polarizing Film 121 Light-absorbing polarizing film protection film 122 Polarizing film protection film

Claims

1. A polarizing film laminate including a polarizing film made of a polyvinyl alcohol-based resin and an optically transparent polarizing film protective film bonded directly or via another optical film to at least a viewing side surface of the polarizing film, The x-axis represents the iodine concentration (wt.%) of the polarizing film, and the y-axis represents the water content (g / m 2 ) in the xy Cartesian coordinate system, Iodine concentration 6.0 wt. % and water content 0.7 g / m 2 The first coordinate point of the iodine concentration is 1.8 wt. % and the water content is 4.2 g / m 2 a first line segment connecting the second coordinate point of The second coordinate point, the iodine concentration of 1.8 wt. % and the water content of 5.1 g / m 2 a second line segment connecting the third coordinate point of The third coordinate point, an iodine concentration of 7.0 wt. % and a water content of 0.7 g / m 2 a third line segment connecting the fourth coordinate point of A fourth line segment connecting the first coordinate point and the fourth coordinate point. The iodine concentration and water content are included in the area surrounded by (excluding the area where the iodine concentration is 4.0 wt.% or more), The polarizing film laminate is characterized in that the polarizing film protective film is a light absorbing layer having a light absorbing ability and has a light transmittance of 5% or less at a wavelength of 380 nm.

2. 2. The polarizing film laminate according to claim 1, wherein the polarizing film has a thickness of 11 to 30 μm.

3. A polarizing film laminate including a polarizing film made of a polyvinyl alcohol-based resin and an optically transparent polarizing film protective film bonded directly or via another optical film to at least a viewing side surface of the polarizing film, The x-axis represents the iodine concentration (wt.%) of the polarizing film, and the y-axis represents the water content (g / m 2 ) in the xy Cartesian coordinate system, Iodine concentration 6.0 wt. % and water content 0.7 g / m 2 The first coordinate point of the iodine concentration is 1.8 wt. % and the water content is 4.2 g / m 2 a first line segment connecting the second coordinate point of The second coordinate point, the iodine concentration of 1.8 wt. % and the water content of 5.1 g / m 2 a second line segment connecting the third coordinate point of The third coordinate point, an iodine concentration of 7.0 wt. % and a water content of 0.7 g / m 2 a third line segment connecting the fourth coordinate point of A fourth line segment connecting the first coordinate point and the fourth coordinate point. (wherein the moisture content is 1.0 g / m 2 The iodine concentration and water content are contained within the above area (excluding the above area), The polarizing film laminate is characterized in that the polarizing film protective film is a light absorbing layer having a light absorbing ability and has a light transmittance of 5% or less at a wavelength of 380 nm.

4. The polarizing film laminate according to claim 3, wherein the polarizing film has a thickness of 4 to 11 μm.

5. 5. The polarizing film laminate according to claim 1, wherein the polarizing film protective film has a transmittance of 35% or less for light having a wavelength of 390 nm.

6. 6. The polarizing film laminate according to claim 1, wherein the polarizing film protective film has a transmittance of 70% or less for light having a wavelength of 400 nm.

7. The polarizing film laminate according to claim 1 , wherein the polarizing film contains zinc.

8. A sample comprising the polarizing film laminate according to any one of claims 1 to 11 and glass plates laminated on both sides of the polarizing film laminate via an adhesive was subjected to a black panel temperature of 89°C and an atmosphere of 30% RH with xenon light having an integrated irradiance of 100 W / m2 in the wavelength range of 300 to 400 nm. 2 8. The polarizing film laminate according to claim 1, wherein the single-unit transmittance after irradiation for 200 hours is -0.5 or more compared to the single-unit transmittance before the irradiation.

9. A sample comprising the polarizing film laminate according to any one of claims 1 to 8 and glass plates laminated on both sides of the polarizing film laminate via an adhesive has an irradiance of 100 W / m2, calculated by irradiating xenon light in the wavelength range of 300 to 400 nm under an atmosphere of a black panel temperature of 89°C and 30% RH. 2 9. The polarizing film laminate according to claim 1 , wherein after irradiation with at least one of these polarizing elements for 200 hours, a change in cross transmittance at a wavelength of 410 nm is less than 1% and a change in cross transmittance at a wavelength of 700 nm is less than 5%.

10. A sample comprising the polarizing film laminate according to any one of claims 1 to 9 and glass plates laminated on both sides of the polarizing film laminate via an adhesive has an irradiance of 100 W / m2, calculated by irradiating xenon light in the wavelength range of 300 to 400 nm under an atmosphere of a black panel temperature of 89°C and 30% RH. 2 10. The polarizing film laminate according to claim 1 , wherein, after being irradiated with at least one of 100 nm for 200 hours, a change in cross transmittance at a wavelength of 410 nm is 1% or more and a change in cross transmittance at a wavelength of 700 nm is less than 5%.

11. an optical display cell; The polarizing film laminate according to any one of claims 1 to 10, which is bonded to one surface of the optical display cell directly or via another optical film; an optically transparent cover plate disposed along the polarizing film stack on an opposite side to the optical display cell; Equipped with The optical display cell, the polarizing film laminate, and the transparent cover plate are bonded together by a transparent adhesive layer that fills the gaps between them without leaving any gaps. An optical display panel comprising:

12. The optical display panel according to claim 11 , wherein the transparent cover plate has a function of a capacitive touch sensor.

13. 13. The optical display panel of claim 12, further comprising an ITO layer, which is a component of a capacitive touch sensor, between the transparent cover plate and the polarizing film laminate.

14. a polarizing film laminate including a polarizing film made of a polyvinyl alcohol-based resin and an optically transparent polarizing film protective film bonded directly or via another optical film to at least a viewing side surface of the polarizing film; a transparent adhesive layer laminated on the viewing side of the polarizing film laminate, The x-axis represents the iodine concentration (wt.%) of the polarizing film, and the y-axis represents the water content (g / m 2 ) in the xy Cartesian coordinate system, Iodine concentration 6.0 wt. % and water content 0.7 g / m 2 The first coordinate point of the iodine concentration is 1.8 wt. % and the water content is 4.2 g / m 2 a first line segment connecting the second coordinate point of The second coordinate point, the iodine concentration of 1.8 wt. % and the water content of 5.1 g / m 2 a second line segment connecting the third coordinate point of The third coordinate point; Iodine concentration 7.0 wt. % and water content 0.7 g / m 2 a third line segment connecting the fourth coordinate point of A fourth line segment connecting the first coordinate point and the fourth coordinate point. The iodine concentration and water content are included in the area surrounded by (excluding the area where the iodine concentration is 4.0 wt.% or more), Among the transparent adhesive layer and the polarizing film protective film, at least the transparent adhesive layer is a light absorbing layer having a light absorbing ability, A polarizing film laminate with a transparent adhesive layer, characterized in that a laminate of the transparent adhesive layer and the polarizing film protection film has a light transmittance of 5% or less at a wavelength of 380 nm.

15. a polarizing film laminate including a polarizing film made of a polyvinyl alcohol-based resin and an optically transparent polarizing film protective film bonded directly or via another optical film to a surface of the polarizing film opposite to a viewing side; a transparent adhesive layer laminated on the viewing side of the polarizing film laminate, The x-axis represents the iodine concentration (wt.%) of the polarizing film, and the y-axis represents the water content (g / m 2 ) in the xy Cartesian coordinate system, Iodine concentration 6.0 wt. % and water content 0.7 g / m 2 The first coordinate point of the iodine concentration is 1.8 wt. % and the water content is 4.2 g / m 2 a first line segment connecting the second coordinate point of The second coordinate point, the iodine concentration of 1.8 wt. % and the water content of 5.1 g / m 2 a second line segment connecting the third coordinate point of The third coordinate point; Iodine concentration 7.0 wt. % and water content 0.7 g / m 2 a third line segment connecting the fourth coordinate point of The iodine concentration and the moisture content are included in a region surrounded by a fourth line segment connecting the first coordinate point and the fourth coordinate point (excluding a region where the iodine concentration is 4.0 wt. % or more), The transparent adhesive layer is a light absorbing layer having a light absorbing ability, A polarizing film laminate with a transparent adhesive layer, wherein the transparent adhesive layer has a light transmittance of 5% or less at a wavelength of 380 nm.

16. a polarizing film laminate including a polarizing film made of a polyvinyl alcohol-based resin and an optically transparent polarizing film protective film bonded directly or via another optical film to at least a viewing side surface of the polarizing film; a transparent adhesive layer laminated on the viewing side of the polarizing film laminate; an optically transparent cover plate laminated on the viewing side of the transparent adhesive layer; The x-axis represents the iodine concentration (wt.%) of the polarizing film, and the y-axis represents the water content (g / m 2 ) in the xy Cartesian coordinate system, Iodine concentration 6.0 wt. % and water content 0.7 g / m 2 The first coordinate point of the iodine concentration is 1.8 wt. % and the water content is 4.2 g / m 2 a first line segment connecting the second coordinate point of The second coordinate point, the iodine concentration of 1.8 wt. % and the water content of 5.1 g / m 2 a second line segment connecting the third coordinate point of The third coordinate point; Iodine concentration 7.0 wt. % and water content 0.7 g / m 2 a third line segment connecting the fourth coordinate point of A fourth line segment connecting the first coordinate point and the fourth coordinate point. The iodine concentration and water content are included in the area surrounded by (excluding the area where the iodine concentration is 4.0 wt.% or more), Among the polarizing film protection film, the transparent adhesive layer, and the transparent cover plate, at least the transparent cover plate is a light absorbing layer having a light absorbing ability, a polarizing film assembly, characterized in that a laminate of the polarizing film protection film, the transparent adhesive layer and the transparent cover plate has a light transmittance of 5% or less at a wavelength of 380 nm.

17. a polarizing film laminate including a polarizing film made of a polyvinyl alcohol-based resin and an optically transparent polarizing film protective film bonded directly or via another optical film to a surface of the polarizing film opposite to a viewing side; a transparent adhesive layer laminated on the viewing side of the polarizing film laminate; an optically transparent cover plate laminated on the viewing side of the transparent adhesive layer; The x-axis represents the iodine concentration (wt.%) of the polarizing film, and the y-axis represents the water content (g / m 2 ) in the xy Cartesian coordinate system, Iodine concentration 6.0 wt. % and water content 0.7 g / m 2 The first coordinate point of the iodine concentration is 1.8 wt. % and the water content is 4.2 g / m 2 a first line segment connecting the second coordinate point of The second coordinate point, the iodine concentration of 1.8 wt. % and the water content of 5.1 g / m 2 a second line segment connecting the third coordinate point of The third coordinate point; Iodine concentration 7.0 wt. % and water content 0.7 g / m 2 a third line segment connecting the fourth coordinate point of The iodine concentration and the moisture content are included in a region surrounded by a fourth line segment connecting the first coordinate point and the fourth coordinate point (excluding a region where the iodine concentration is 4.0 wt. % or more), Among the transparent adhesive layer and the transparent cover plate, at least the transparent cover plate is a light absorbing layer having a light absorbing ability, A polarizing film assembly, characterized in that a laminate of the transparent adhesive layer and the transparent cover plate has a light transmittance of 5% or less at a wavelength of 380 nm.

Images