WO2021039987A1

WO2021039987A1 - Polarizing film laminate, optical display panel in which said polarizing film laminate is used, polarizing film laminate with transparent adhesive layer, and polarizing film assembly

Info

Publication number: WO2021039987A1
Application number: PCT/JP2020/032666
Authority: WO
Inventors: 大祐大塚; 河村　亮; 章典伊▲崎▼; 周一谷; 哲郎竹田; 勝則高田; 木村　啓介; 山下　智弘; 杉野　洋一郎
Original assignee: 日東電工株式会社
Priority date: 2019-08-28
Filing date: 2020-08-28
Publication date: 2021-03-04
Also published as: KR20220054320A; CN114303080A

Abstract

Provided are, inter alia, a polarizing film laminate in which the effect of solar irradiation is suppressed, whereby the problems of polyene formation, color loss, and heat-induced reddening can be comprehensively overcome. In an orthogonal coordinate system having the iodine concentration (wt%) of a polarizing membrane along the x-axis and the moisture content (g/m²) of the polarizing film laminate along the y-axis, the iodine concentration and moisture content are contained within the region surrounded by a first line segment connecting a first coordinate point (x: 6.0, y: 0.7) and a second coordinate point (x: 1.8, y: 4.2), a second line segment connecting the second coordinate point and a third coordinate point (x: 1.8, y: 5.1), a third line segment connecting the third coordinate point and a fourth coordinate point (x: 5.7, y: 2.6), a fourth line segment connecting the fourth coordinate point and a fifth coordinate point (x: 7.0, y: 0.7), and a fifth line segment connecting the first coordinate point and the fifth coordinate point. In the present invention, a polarizing-membrane protective film is a light-absorbing layer having a light-absorption function, the film transmitting no more than 5% of light having a wavelength of 380 nm.

Description

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.

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.

In recent years, optical display panels such as liquid crystal panels and organic EL panels have been used not only for electronic devices such as smartphones and personal computers, and for electrical appliances such as IoT home appliances, but also for powered vehicles such as automobiles, trains, and airplanes. As for, various possibilities have been found. For example, it is conceivable to mount an optical display panel on the windshield, dashboard, exterior, and various other vehicle body parts of an automobile to provide various information to the driver and to transmit various information to the outside.

Along with such a situation, for example, further improvement of durability in a harsh environment such as in a powered vehicle is required. For example, it is used for an optical display panel, particularly a polarizing film laminate (polarizing plate) used for an optical display panel, and further for a polarizing film laminate due to a usage environment such as high temperature or high humidity or by irradiation with sunlight. The performance of the polarizing film (polarizer) is deteriorated, and in the worst case, it may become unusable.

Patent Document 1 discloses an example of a polarizing element having improved durability in a high temperature or high humidity environment, a polarizing plate using this polarizing element, and a liquid crystal display device using the polarizing plate. In terms of durability, red loss (polarization loss of long-wavelength light) in orthogonal Nicol that occurs when left under high temperature conditions is regarded as a problem, and in order to solve this problem, zinc is added. , It has been proposed to adjust this zinc content to a predetermined range in relation to the iodine content.

Similarly, Patent Document 2 relates to a polarizing plate used in an in-vehicle image display device having improved durability in a high temperature or high humidity environment, and here, the water content of the polarizing plate and the protective film. We are focusing on saturated water absorption. Polarized light for automobiles is required to have high temperature durability, but in a high temperature environment, the transmittance of the polarizing plate may be significantly lowered due to polyene formation. In order to solve this problem, Patent Document 2 describes it. It has been proposed to use a transparent protective film having a saturated water absorption within a predetermined range as a transparent protective film to be bonded to a polarizing element, and to reduce the water content of the polarizing plate.

Patent Document 3 also relates to a polarizing plate having improved durability under high temperature or high humidity, and here, attention is paid to the moisture content of the polarizing plate and the moisture permeability of the protective film. In a high temperature environment or the like, the inside of the polarizing plate becomes a high temperature and high humidity state, and as a result, the amount of change in the light transmittance, the degree of polarization, the hue of the image, etc. becomes large, and the reliability of the polarizing plate becomes low. Therefore, it has been proposed to attach a protective film having low moisture permeability in a state where the water content of the polarizer is reduced as much as possible.

Similarly, Patent Document 4 relates to a polarizing plate having improved durability under high temperature or high humidity or low temperature, and here, the polarizer can be deteriorated by ultraviolet rays or infrared rays, and It has been described that the visibility of a liquid crystal display (LCD) may deteriorate due to use at high temperature or under high temperature and high humidity. To solve these problems, an ultraviolet absorber or an ultraviolet absorber is applied to the protective film of the polarizing film. It has been proposed to include an infrared absorber to prevent fluctuations in transmittance.

Japanese Unexamined Patent Publication No. 2003-29042 Japanese Unexamined Patent Publication No. 2014-102353 JP-A-2002-90546 Japanese Unexamined Patent Publication No. 2006-184883

Regarding the polarizing film laminate used for the optical display panel, especially the optical display panel, and the polarizing film used for the polarizing film laminate, problems that occur in a high temperature or high humidity environment include "polyene formation" and "color loss". , And "heated reddish" are known.

In general, "polyenization" is a phenomenon in which the single transmittance of a polarizing film laminate is lowered by being placed in a high temperature or high humidity environment, and "color loss" and "heating reddening" are the same. When the polarizing film laminate is cross-nicoled and the orthogonal transmittance at a wavelength of 410 nm and a wavelength of 700 nm is measured by being placed in a high temperature or high humidity environment, the orthogonal transmittance is lowered. "Color loss" is a phenomenon in which the transmittance on the long wavelength side of about 700 nm and the short wavelength side of about 410 nm increases to cause color loss in black display, while "heat red discoloration" is particularly long of about 700 nm. It is known as a phenomenon in which the transmittance on the wavelength side increases and the polarizing film turns red.

Patent Document 1 mainly focuses on the problem of "color loss", Patent Document 2 mainly focuses on the problem of "polyenization", and Patent Document 3 mainly focuses on the problem of "heating reddening". The solutions proposed in each document are considered to be effective at least for solving individual problems. However, the inventions described in each patent document have not always been sufficient to comprehensively solve these problems. The fact that "polyenization", "color loss", and "heated reddening" are all interrelated through iodine and moisture, as well as through the temperature and humidity that affect moisture. Based on this, as a result of repeated diligent research, the applicant of the present application has found that these problems can be comprehensively solved by adjusting the iodine concentration of the polarizing film and the water content of the polarizing film laminate. ..

As a result of further diligent research, the applicant of the present application has found that sunlight, more accurately, ultraviolet rays, visible rays, and infrared rays contained in sunlight are "polyenized", "color loss", and "heated reddening". In addition to adjusting the iodine concentration of the polarizing film and the water content of the polarizing film laminate, it also suppresses the influence of sunlight by discovering that it promotes, especially, "polyene formation". By doing so, it was found that the problems of "polyene formation", "color loss", and "heated reddish color" can be solved more effectively.

In the present invention, in addition to adjusting the iodine concentration of the polarizing film and the water content of the polarizing film laminate, by suppressing the influence of sunlight irradiation, "polyene formation", "color loss", and "color loss", and " The purpose is to comprehensively solve these three problems, such as "heating reddening".

In order to solve the above problems, the polarizing film film laminate according to one aspect of the present invention has a polarizing film made of a polyvinyl alcohol-based resin and at least the surface of the polarizing film on the visible side directly or via another optical film. A polarizing film laminate provided with a bonded optically transparent polarizing film protective film, wherein the x-axis is the iodine concentration (wt.%) Of the polarizing film, and the y-axis is the polarizing film laminate. In the xy orthogonal coordinate system in which the water content (g / m ² ) was taken, the iodine concentration was 6.0 wt. % And the first coordinate point with a water content of 0.7 g / m ² and an iodine concentration of 1.8 wt. % And a first line segment connecting a second coordinate point having a water content of 4.2 g / m ² , the second coordinate point and an iodine concentration of 1.8 wt. % And a second line segment connecting a third coordinate point having a water content of 5.1 g / m ² , the third coordinate point and an iodine concentration of 5.7 wt. % And a third line segment connecting the fourth coordinate point having a water content of 2.6 g / m ² , the fourth coordinate point and the iodine concentration of 7.0 wt. In the area surrounded by the fourth line segment connecting the fifth coordinate point of% and the water content of 0.7 g / m ² and the fifth line segment connecting the first coordinate point and the fifth coordinate point. The polarizing film protective film having an iodine concentration and a water content contained therein 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.
According to the polarizing film film laminate of this aspect, the problems of "polyene formation", "color loss", and "heat reddening" can be comprehensively solved.

In the polarizing film film laminate of the above aspect, the film thickness of the polarizing film may be 4 to 30 μm.

Further, in the polarizing film film laminate according to another aspect of the present invention, the polarizing film made of a polyvinyl alcohol-based resin is optically bonded to at least the visible surface of the polarizing film directly or via another optical film. A polarizing film laminate provided with a transparent polarizing film protective film, the x-axis is the iodine concentration (wt.%) Of the polarizing film, and the y-axis is the water content (g / g /) of the polarizing film laminate. In the ^{xy orthogonal coordinate system in which m 2} ) was taken, the iodine concentration was 4.5 wt. The sixth coordinate point of% and water content of 1.9 g / m ² and the iodine concentration of 1.8 wt. % And a sixth line segment connecting the second coordinate point having a water content of 4.2 g / m ² , the second coordinate point and the iodine concentration of 1.8 wt. % And a second line segment connecting a third coordinate point having a water content of 5.1 g / m ² , the third coordinate point and an iodine concentration of 4.5 wt. In the area surrounded by the 7th line segment connecting the 7th coordinate point of% and the water content of 3.4 g / m ² and the 8th line segment connecting the 6th coordinate point and the 7th coordinate point. The polarizing film protective film having an iodine concentration and a water content contained therein 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.

In the polarizing film film laminate of the above aspect, the sixth coordinate point has an iodine concentration of 4.0 wt. % And the water content is 2.4 g / m ² , which is the eighth coordinate point, and the seventh coordinate point is the iodine concentration of 4.0 wt. It may be the ninth coordinate point of% and the water content of 3.7 g / m ^2.
Further, the sixth coordinate point has an iodine concentration of 3.7 wt. It is the tenth coordinate point of% and the water content of 2.6 g / m ² , and the seventh coordinate point may be the fourth coordinate point.

In the polarizing film film laminate of the above aspect, the film thickness of the polarizing film may be 11 to 30 μm.

Further, in the polarizing film film laminate according to another aspect of the present invention, the polarizing film made of a polyvinyl alcohol-based resin is optically bonded to at least the visible surface of the polarizing film directly or via another optical film. A polarizing film laminate provided with a transparent polarizing film protective film, the x-axis is the iodine concentration (wt.%) Of the polarizing film, and the y-axis is the water content (g / g /) of the polarizing film laminate. In the ^{xy orthogonal coordinate system in which m 2} ) was taken, the iodine concentration was 6.0 wt. % And the first coordinate point with a water content of 0.7 g / m ² and an iodine concentration of 3.7 wt. % And the ninth line segment connecting the tenth coordinate point having a water content of 2.6 g / m ² , the tenth coordinate point and the iodine concentration of 5.7 wt. The tenth line segment connecting the fourth coordinate point of% and the water content of 2.6 g / m ² , the fourth coordinate point, and the iodine concentration of 7.0 wt. In the area surrounded by the eleventh line segment connecting the fifth coordinate point of% and the water content of 0.7 g / m ² and the fifth line segment connecting the first coordinate point and the fifth coordinate point. The polarizing film protective film having an iodine concentration and a water content contained therein 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.

In the polarizing film film laminate of the above aspect, the film thickness of the polarizing film may be 4 to 11 μm.

Further, in the polarizing film film laminate of the above aspect, 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 has a wavelength of 400 nm. The light transmittance is preferably 70% or less.

Further, in the polarizing film film laminate of the above aspect, it is preferable that the polarizing film contains zinc.

Further, in the polarizing film film laminate of the above aspect, a sample composed of the polarizing film laminate and the glass plate laminated on both sides of the polarizing film laminate with an adhesive is provided at a black panel temperature of 89 ° C. and 30 ° C. % R. H. The single transmittance after irradiating xenon light in the wavelength range of 300 to 400 nm ^{for 200 hours with an irradiance of 100 W / m 2} is -0.5 or more as compared with the single transmittance before irradiation. Is preferable.
Thereby, the problem of polyene formation can be effectively solved.

In the polarizing film film laminate of the above aspect, a black panel temperature of 89 ° C., 30% R in a sample comprising a polarizing film laminate and a glass plate laminated on both sides of the polarizing film laminate with an adhesive. .. H. After irradiating xenone light in the wavelength range of 300 to 400 nm ^{for 200 hours with an irradiance of 100 W / m 2} , the amount of change in the orthogonal transmittance at a wavelength of 410 nm is less than 1% and at a wavelength of 700 nm. It is preferable that the amount of change in the orthogonal transmittance of is less than 5%.
As a result, the problem of color loss can be effectively solved.

In the polarizing film film laminate of the above aspect, a black panel temperature of 89 ° C., 30% R in a sample comprising a polarizing film laminate and a glass plate laminated on both sides of the polarizing film laminate with an adhesive. .. H. After irradiating xenone light in the wavelength range of 300 to 400 nm ^{for 200 hours with an irradiance of 100 W / m 2} , the amount of change in the orthogonal transmittance at a wavelength of 410 nm is 1% or more, and the wavelength is 700 nm. It is preferable that the amount of change in the orthogonal transmittance of is less than 5%.
Thereby, the problem of heating redness can be effectively solved.

Further, in order to solve the above problems, the optical display panel according to one aspect of the present invention is bonded to the optical display cell directly or via another optical film on one surface of the optical display cell. The optical display cell comprising the polarizing film laminate according to any one of the above and an optically transparent cover plate arranged along the polarizing film laminate on the side opposite to the optical display cell. An optical display panel attached to the vehicle body of a powered vehicle is characterized in that the polarizing film laminate and the transparent cover plate are adhered to each other by a transparent adhesive layer that fills the space between them without any gaps. To do.

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

Further, in the optical display panel of the above aspect, an ITO layer which is a component of the capacitive touch sensor may be provided between the transparent cover plate and the polarizing film laminate.

The polarizing film laminate with a transparent adhesive layer according to one aspect of the present invention is optically bonded to a polarizing film made of a polyvinyl alcohol-based resin directly or via another optical film on the surface of the polarizing film on at least the visible side. A polarizing film laminate provided with a transparent polarizing film protective film and a transparent adhesive layer laminated on the visual side of the polarizing film laminate are provided, and the iodine concentration (wt) of the polarizing film is provided on the x-axis. ^{In an xy orthogonal coordinate system in which the water content (g / m 2} ) of the polarizing film laminate was taken on the y-axis, the iodine concentration was 6.0 wt. % And the first coordinate point with a water content of 0.7 g / m ² and an iodine concentration of 1.8 wt. % And a first line segment connecting a second coordinate point having a water content of 4.2 g / m ² , the second coordinate point and an iodine concentration of 1.8 wt. % And a second line segment connecting a third coordinate point having a water content of 5.1 g / m ² , the third coordinate point and an iodine concentration of 5.7 wt. % And a third line segment connecting the fourth coordinate point having a water content of 2.6 g / m ² , the fourth coordinate point and the iodine concentration of 7.0 wt. In the area surrounded by the fourth line segment connecting the fifth coordinate point of% and the water content of 0.7 g / m ² and the fifth line segment connecting the first coordinate point and the fifth coordinate point. Of the transparent adhesive layer and the polarizing film protective film having the iodine concentration and the amount of water contained, at least the transparent adhesive layer is a light absorbing layer having a light absorbing ability, and the transparent adhesive layer and the polarizing film It is characterized in that the light transmittance of the laminated body of the protective film at a wavelength of 380 nm is 5% or less.

The polarizing film laminate with a transparent adhesive layer according to another aspect of the present invention is bonded to a polarizing film made of a polyvinyl alcohol-based resin directly or via another optical film on the surface of the polarizing film opposite to the visible side. A polarizing film laminate provided with an optically transparent polarizing film protective film and a transparent adhesive layer laminated on the visual side of the polarizing film laminate are provided, and iodine of the polarizing film is provided on the x-axis. In an xy orthogonal coordinate system in which the ^{concentration (wt.%) Is the water content (g / m 2} ) of the polarizing film laminate on the y-axis, the iodine concentration is 6.0 wt. % And the first coordinate point with a water content of 0.7 g / m ² and an iodine concentration of 1.8 wt. % And the first line segment connecting the second coordinate point having a water content of 4.2 g / m ² , the second coordinate point and the iodine concentration of 1.8 wt. % And a second line segment connecting a third coordinate point having a water content of 5.1 g / m ² , the third coordinate point and an iodine concentration of 5.7 wt. % And a third line segment connecting the fourth coordinate point having a water content of 2.6 g / m ² , the fourth coordinate point and the iodine concentration of 7.0 wt. In the area surrounded by the fourth line segment connecting the fifth coordinate point of% and the water content of 0.7 g / m ² and the fifth line segment connecting the first coordinate point and the fifth coordinate point. The transparent adhesive layer having an iodine concentration and a water content contained therein is a light absorbing layer having a light absorbing ability, and is characterized in that the light transmittance of the transparent adhesive layer at a wavelength of 380 nm is 5% or less. Have as.

The polarizing film assembly according to one aspect of the present invention is an optically transparent polarized light bonded to a polarizing film made of a polyvinyl alcohol-based resin directly to at least the surface of the polarizing film on the visible side or via another optical film. A polarizing film laminate provided with a film protective film, a transparent adhesive layer laminated on the visual side of the polarizing film laminate, and an optically transparent cover plate laminated on the visual side of the transparent adhesive layer. In the xy orthogonal coordinate system, the x-axis is the iodine concentration (wt.%) Of the polarizing film and the y-axis is the water content (g / m ^{2) of the polarizing film laminate.} Concentration 6.0 wt. % And the first coordinate point with a water content of 0.7 g / m ² and an iodine concentration of 1.8 wt. % And the first line segment connecting the second coordinate point having a water content of 4.2 g / m ² , the second coordinate point and the iodine concentration of 1.8 wt. % And a second line segment connecting a third coordinate point having a water content of 5.1 g / m ² , the third coordinate point and an iodine concentration of 5.7 wt. % And a third line segment connecting the fourth coordinate point having a water content of 2.6 g / m ² , the fourth coordinate point and the iodine concentration of 7.0 wt. In the area surrounded by the fourth line segment connecting the fifth coordinate point of% and the water content of 0.7 g / m ² and the fifth line segment connecting the first coordinate point and the fifth coordinate point. Of the polarizing film protective film, the transparent adhesive layer, and the transparent cover plate having the iodine concentration and the amount of water contained, at least the transparent cover plate is a light absorbing layer having a light absorbing ability, and the said. It is characterized in that the light transmittance of the polarizing film protective film, the transparent adhesive layer, and the laminated body of the transparent cover plate at a wavelength of 380 nm is 5% or less.

The polarizing film assembly according to another aspect of the present invention is optically bonded to a polarizing film made of a polyvinyl alcohol-based resin directly or via another optical film on the surface of the polarizing film opposite to the visible side. A polarizing film laminate provided with a transparent polarizing film protective film, a transparent adhesive layer laminated on the visible side of the polarizing film laminate, and an optically transparent laminate laminated on the visual side of the transparent adhesive layer. An xy orthogonal coordinate system provided with a cover plate, with the iodine concentration (wt.%) Of the polarizing film on the x-axis and the water content (g / m ^{2) of the polarizing film laminate on the y-axis.} The iodine concentration was 6.0 wt. % And the first coordinate point with a water content of 0.7 g / m ² and an iodine concentration of 1.8 wt. % And a first line segment connecting a second coordinate point having a water content of 4.2 g / m ² , the second coordinate point and an iodine concentration of 1.8 wt. % And a second line segment connecting a third coordinate point having a water content of 5.1 g / m ² , the third coordinate point and an iodine concentration of 5.7 wt. % And a third line segment connecting the fourth coordinate point having a water content of 2.6 g / m ² , the fourth coordinate point and the iodine concentration of 7.0 wt. In the area surrounded by the fourth line segment connecting the fifth coordinate point of% and the water content of 0.7 g / m ² and the fifth line segment connecting the first coordinate point and the fifth coordinate point. Of the transparent adhesive layer and the transparent cover plate having the iodine concentration and the amount of water contained, at least the transparent cover plate is a light absorption layer having a light absorbing ability, and the transparent adhesive layer and the transparent cover plate. It is characterized in that the light transmittance of the laminated body of the cover plate at a wavelength of 380 nm is 5% or less.

According to the present invention, in addition to adjusting the iodine concentration of the polarizing film and the water content of the polarizing film laminate, by suppressing the influence of sunlight irradiation, "polyene formation", "color loss", and The problem of "heating reddening" can be solved comprehensively.

It is a schematic diagram which shows the layer structure of an optical display panel. It is a figure explaining an example of the manufacturing method of the polarizing film. It is a figure which shows the layer structure example of the polarizing film protective film located on the viewing side. It is a figure which shows the calibration curve for determining the iodine concentration of a polarizing film. It is a figure which shows the structure for a reliability test. It is a figure which plotted the result of an Example and a comparative example centering on an Example. It is a figure which plotted the result of an Example and a comparative example centering on a comparative example.

Hereinafter, one preferred embodiment of the present invention will be described with reference to the accompanying drawings. Only suitable embodiments are shown for convenience of explanation, but of course, this is not intended to limit the invention.

The present invention relates to an optical display panel, for example, an optical display panel attached to the vehicle body of an automobile, a train, an airplane, or other powered traveling vehicle, and a polarizing film laminate used for the optical display panel. set to target. 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, for example, the optical display panel or the polarizing film laminate used in a smartphone or the like. It also includes the case where they are freely mounted or brought into a powered vehicle like a body. Furthermore, "mounted on the vehicle body" includes all situations in which an optical display panel or polarizing film laminate is used with a powered vehicle and may be exposed to high temperature or high humidity environments.

1. 1. Optical display panel FIG. 1 is a schematic view showing an example of the layer structure of the optical display panel 1. The optical display panel 1 is at least opposite to the optical display cell 10, the polarizing film laminate 12 laminated on one surface 10a side (visual side) of the optical display cell 10, and the optical display cell 10. Includes an optically transparent cover plate 14 arranged along the polarizing film laminate 12 on the side, that is, on the visual side. The optical display cell 10 and the polarizing film laminate 12 are adhered to each other without any voids by using a transparent adhesive layer made of a transparent adhesive (PSA) 11. Similarly, between the cover plate 14 and the polarizing film laminate 12, a transparent adhesive layer made of a transparent adhesive (OCA) 13 laminated on the visual side of the polarizing film laminate 12 is used so that there are no voids. Adhered to form a polarizing film assembly 19, including a cover plate 14, a transparent adhesive 13, and a polarizing film laminate 12. Another polarizing film laminate 17 is arranged on the other surface 10b side of the optical display cell 10 via a transparent adhesive (PSA) 16. In the present specification, unless otherwise specified, the term "adhesive" includes adhesive (pressure sensitive adhesive). The optical display cell 10 and the polarizing film laminate 12 may be directly bonded by the transparent adhesive 11, but if necessary, other optical films such as a retardation film and a viewing angle compensation film (not shown). ) May be adhered.

1-1. Optical display cell Examples of the optical display cell 10 include a liquid crystal cell and an organic EL cell.
As the organic EL cell, a cell in which a transparent electrode, an organic light emitting layer, and a metal electrode are sequentially laminated on a transparent substrate to form a light emitting body (organic electroluminescence light emitting body) or the like is preferably used. The organic light emitting layer is a laminate of various organic thin films, for example, 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, or a laminate of these. Various layer configurations can be adopted, such as a laminate of electron injection layers composed of a light emitting layer and a perylene derivative, or a laminate of hole injection layers, light emitting layers, and electron injection layers.

The liquid crystal cell includes 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, and a semi-transmissive semi-reflection that uses both external light and light from a light source. Any type liquid crystal cell may be used. When the liquid crystal cell utilizes the light from the light source, as shown in FIG. 1, the polarizing film laminate 17 is also arranged on the side opposite to the visible side of the optical display cell (liquid crystal cell) 10, and further. For example, a light source 18 such as a backlight is arranged. The polarizing film laminate 17 on the light source side and the liquid crystal cell 10 are adhered by an appropriate layer of a transparent adhesive 16. As the driving method of the liquid crystal cell, for example, any type such as VA mode, IPS mode, TN mode, STN mode and bend orientation (π type) can be used.

1-2. Cover plate Examples of the cover plate 14 include a transparent plate (window layer), a touch panel, and the like. As the transparent plate, a transparent plate having appropriate mechanical strength and thickness is used. As such a transparent plate, for example, a transparent resin plate such as an acrylic resin or a polycarbonate resin, a glass plate, or the like is used. The surface of the cover plate 14 may be subjected to a low reflection treatment by, for example, a low reflection film (not shown). As the touch panel, various touch panels such as a resistive film method, a capacitance method, an optical method, an ultrasonic method, and a glass plate or a transparent resin plate having a touch sensor function are used.

The cover plate 14 may contain an ultraviolet absorber to form a light absorbing layer having a light absorbing ability, in other words, the transmittance of the cover plate 14 to ultraviolet rays may be set to a desired value. For example, the cover plate 14 is formed of a transparent resin plate such as an acrylic resin or a polycarbonate resin, or a glass plate, and at the time of its production, for example, benzotriazole-based, benzophenone-based, salicylate phenyl ester-based, or triazine-based. Examples include UV absorbers. Examples of the benzotriazole-based ultraviolet absorber include 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- (2H-benzotriazole-2-yl) -p-cresol, and 2- (2H-benzotriazole). -2-yl) -4,6-di-tert-pentylphenol, 2- (2'-hydroxy-5'methacryloxyethylphenyl) -2H-benzotriazole and the like can be mentioned. Examples of the benzophenone-based ultraviolet absorber include 2-hydroxy-4-octoxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxy-4'-chlorobenzophenone, and 2,2-dihydroxy-4-methoxy. Benzophenone, 2,2-dihydroxy-4,4'-dimethoxybenzophenone and the like can be mentioned. Examples of the salicylic acid phenyl ester-based ultraviolet absorber include pt-butylphenyl salicylate ester and the like. Examples of the triazine-based ultraviolet absorber include 2,4-diphenyl-6- (2-hydroxy-4-methoxyphenyl) -1,3,5-triazine and 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-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 The cover plate 14 is illuminated by mixing an ultraviolet absorber such as -triazine, 2,4-diphenyl-6- (2-hydroxy-4-butoxyethoxyphenyl) -1,3,5-triazine in the transparent resin. It can be used as an absorbent layer. By providing the light absorption layer, the transmittance of ultraviolet rays in the polarizing film assembly 19 including the polarizing film laminate 12 can be set to a desired value, and more effectively, "polyene formation", "color loss", and "heated red". You can comprehensively solve the problem of "oddness". When only the cover plate 14 is used as the light absorption layer, for example, the transmittance at a wavelength of 380 nm is preferably 5% or less, more preferably 3% or less, still more preferably 2% or less. The lower limit is, for example, 0.1% or more and 1% or more. The transmittance at a wavelength of 390 nm is preferably 35% or less, more preferably 30% or less, still more preferably 28% or less. The lower limit is, for example, 10% or more, 20% or more, and 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, 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 and 85% or more. These transmittances indicate the transmittance of the cover plate 14 in the initial state. In addition to ultraviolet absorbers, phthalocyanine-based light absorbers, naphthalocyanine-based light absorbers, polymethine-based light absorbers, diphenylmethane-based light absorbers, triphenylmethane-based light absorbers, quinone-based light absorbers, and azo-based light absorbers. An infrared absorber such as a light absorber may be mixed.

When a capacitance type touch panel is used as the cover plate 14, it is preferable that a front transparent plate made of glass or a transparent resin plate is provided on the visual side of the touch panel. Further, in this case, an ITO layer (not shown) which is a component of the capacitive touch sensor is provided on the transparent adhesive 13 that joins the cover plate 14 and the polarizing film laminate 12.

1-3. Transparent Adhesive As the

transparent adhesives

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

transparent adhesives

11, 13 and 16.

The

transparent adhesives

11, 13, 16, for example, the transparent adhesive 13 (transparent adhesive layer) laminated on the visual side of the polarizing film laminate 12 contains an ultraviolet absorber to absorb light having a light absorbing ability. It may be a layer, in other words, the transmittance of the transparent adhesive to ultraviolet rays may be set to a desired value. For example, a transparent adhesive is formed of a (meth) acrylic pressure-sensitive adhesive, and at the time of its production, examples thereof include benzotriazole-based, benzophenone-based, salicylate phenyl ester-based, and triazine-based UV absorbers. Examples of the benzotriazole-based ultraviolet absorber include 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- (2H-benzotriazole-2-yl) -p-cresol, and 2- (2H-benzotriazole). -2-yl) -4,6-di-tert-pentylphenol, 2- (2'-hydroxy-5'methacryloxyethylphenyl) -2H-benzotriazole and the like can be mentioned. Examples of the benzophenone-based ultraviolet absorber include 2-hydroxy-4-octoxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxy-4'-chlorobenzophenone, and 2,2-dihydroxy-4-methoxy. Benzophenone, 2,2-dihydroxy-4,4'-dimethoxybenzophenone and the like can be mentioned. Examples of the salicylic acid phenyl ester-based ultraviolet absorber include pt-butylphenyl salicylate ester and the like. Examples of the triazine-based ultraviolet absorber include 2,4-diphenyl-6- (2-hydroxy-4-methoxyphenyl) -1,3,5-triazine and 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-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 -Light the transparent adhesive by mixing an ultraviolet absorber such as triazine, 2,4-diphenyl-6- (2-hydroxy-4-butoxyethoxyphenyl) -1,3,5-triazine in the transparent resin. It can be used as an absorbent layer. By providing such a light absorbing layer, it is more effective to set the transmittance of ultraviolet rays in the polarizing film laminate 12 with the transparent adhesive layer or the polarizing film assembly 19 including the polarizing film laminate 12 as a desired value. In addition, the problems of "polyene formation", "color loss", and "heating reddening" can be comprehensively solved. When only the transparent adhesive 13 is used as the light absorption layer, for example, the transmittance at a wavelength of 380 nm is preferably 5% or less, more preferably 3% or less, still more preferably 2% or less. The lower limit is, for example, 0.1% or more and 1% or more. The transmittance at a wavelength of 390 nm is preferably 35% or less, more preferably 30% or less, still more preferably 28% or less. The lower limit is, for example, 10% or more, 20% or more, and 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, 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 and 85% or more. These transmittances indicate the transmittance of the transparent adhesive in the initial state. In addition to ultraviolet absorbers, phthalocyanine-based light absorbers, naphthalocyanine-based light absorbers, polymethine-based light absorbers, diphenylmethane-based light absorbers, triphenylmethane-based light absorbers, quinone-based light absorbers, and azo-based light absorbers. An infrared absorber such as a light absorber may be mixed.

2. 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 visible 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 visible side of the polarizing film 120. In addition to or instead of using the cover plate 14 and / or the transparent adhesive 13 as the light absorbing layer, the polarizing film protective film 121 may function as the light absorbing layer. By providing the light absorption layer, the problem of "polyene formation", "color loss", and "heat red discoloration" can be more effectively set by setting the ultraviolet transmittance of the polarizing film laminate 12 itself to a desired value. It can be solved comprehensively. Although not particularly shown, another optical film may be provided between the polarizing film 120 and the polarizing film

protective films

121 and 122.

The present invention is to comprehensively solve the problems caused by the usage environment such as high temperature or high humidity and by the irradiation of sunlight, particularly the problems of "polyenation", "color loss", and "heating reddening". In particular, attention is paid to the iodine concentration (wt.%) Of the polarizing film 120 and the water content (g / m ^{2) of the polarizing film laminate 12.} These values can be adjusted, for example, during the production of the polarizing film or the production of the polarizing film laminate.

2-1. Polarizing film The polarizing film 120 is made of a polyvinyl alcohol (PVA) -based resin film containing iodine. As the material of the PVA-based film applied to the polarizing film, PVA or a derivative thereof is used. Examples of the PVA derivative include polyvinyl formal, polyvinyl acetal and the like, olefins such as ethylene and propylene, unsaturated carboxylic acids such as acrylic acid, methacrylic acid and crotonic acid, alkyl esters thereof, and those modified with acrylamide and the like. Be done. As PVA, a PVA having a degree of polymerization of about 1000 to 10000 and a degree of saponification of about 80 to 100 mol% is generally used. PVA-based films made of these materials tend to contain moisture.

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

2-1-1. Production of Polarizing Film In the production of a polarizing film having a thickness of 6 μm or more, for example, a dyeing treatment in which the PVA-based film is dyed with iodine and a stretching treatment in which the PVA-based film is stretched in at least one direction are performed. Generally, a method is adopted in which the PVA-based film is subjected to a series of treatments including swelling, dyeing, cross-linking, stretching, washing with water and drying treatment.

The swelling treatment is performed, for example, by immersing a PVA-based film in a swelling bath (water bath). By this treatment, stains on the surface of the PVA-based film and blocking inhibitor are cleaned, and the PVA-based film is swollen to prevent non-uniformity such as uneven dyeing. Glycerin, potassium iodide and the like 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.

The dyeing treatment is performed, for example, by immersing a PVA-based film in an iodine solution. The iodine solution is usually an aqueous iodine solution and contains iodine and potassium iodide as a solubilizing agent. The iodine concentration is, for example, about 0.01 to 1% by weight, preferably 0.02 to 0.5% by weight. The potassium iodide concentration is, for example, about 0.01 to 10% by weight, preferably 0.02 to 8% by weight.

In the dyeing process, 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 in the range of 20 to 240 seconds. In the iodine dyeing treatment, conditions such as the concentration of the iodine solution, the immersion temperature of the PVA film in the iodine solution, and the immersion time are adjusted so that the iodine content and the potassium content in the PVA film are within the above ranges. Will be done.

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

The stretching treatment is a treatment in which the PVA-based film is stretched in at least one direction. Generally, the PVA-based film is uniaxially stretched in the transport direction (longitudinal direction). The stretching method is not particularly limited, and either a wet stretching method or a dry stretching method can be adopted. When the wet stretching method is adopted, the PVA-based film is stretched to a predetermined magnification in the treatment bath. As the solution of the stretching bath, a solution in which compounds necessary for various treatments are added to a solvent such as water or an organic solvent (for example, ethanol) is preferably used. Examples of the dry stretching method include an inter-roll stretching method, a heating roll stretching method, and a compression stretching method. In the production of the polarizing film, the stretching treatment may be performed at any stage. Specifically, it may be performed at the same time as swelling, staining, and cross-linking, and may be performed before or after each of these treatments. Further, the stretching may be performed in multiple stages. The cumulative draw ratio of the PVA-based film is, for example, 5 times or more, preferably about 5 to 7 times.

The PVA-based film (stretched film) subjected to each of the above treatments is subjected to a water washing treatment and a drying treatment according to a conventional method.

The water washing treatment is performed, for example, by immersing a PVA-based film in a water washing bath. The water washing bath may be pure water or an aqueous solution of iodide (for example, potassium iodide, sodium iodide, etc.). The concentration of the aqueous iodide solution is preferably 0.1 to 10% by weight. Auxiliary agents such as zinc sulfate and zinc chloride may be added to the aqueous iodide solution.

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, preferably 20 to 240 seconds. The water washing treatment may be carried out only once, or may be carried out a plurality of times as needed. When the water washing treatment is performed a plurality of times, the type and concentration of the additive contained in the water washing bath used for each treatment are appropriately adjusted.

The PVA-based film is dried by any suitable method (for example, natural drying, blast drying, heat drying).

2-1-2. Production of Polarizing Film A polarizing film having a film 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 preparation process for forming a PVA-based resin layer on a thermoplastic base material, a stretching treatment for stretching the PVA-based resin layer integrally with the thermoplastic resin base material, and a bicolor substance on the PVA resin layer. Includes dyeing treatment to be adsorbed. If necessary, insolubilization treatment, cross-linking treatment, drying treatment, cleaning treatment and the like of the PVA-based resin layer can also be applied. The stretching treatment can be carried out before or after the dyeing treatment, and either stretching method of air stretching or stretching in water such as an aqueous boric acid solution can be adopted. Further, the stretching may be a one-step stretching or a multi-step stretching of two or more steps.

An example of a method for manufacturing a polarizing film will be described with reference to FIG. Here, a polarizing film is produced by stretching a PVA-based resin layer formed on a resin base material integrally with the resin base material.

[Laminate body preparation process (A)]
First, an amorphous ester-based thermoplastic resin base material having a glass transition temperature of 75 ° C. and a thickness of 200 μm, for example, isophthalic acid copolymerized polyethylene terephthalate obtained by copolymerizing 6 mol% of isophthalic acid (hereinafter, “acrystalline PET””. 6 and a PVA aqueous solution having a concentration of 4 to 5% by weight in which a PVA powder having a degree of polymerization of 1000 or more and a degree of saponification of 99% or more is dissolved in water are prepared. Next, in the laminate manufacturing apparatus 20 provided with the coating means 21, the drying means 22, and the surface modification treatment apparatus 23, a PVA aqueous solution is applied to the amorphous PET base material 6 at a temperature of 50 to 60 ° C. After drying, a PVA layer 2 having a glass transition temperature of 80 ° C. and a thickness of 7 μm is formed on the PET substrate 6. As a result, the laminated body 7 including the PVA layer having a thickness of 7 μm is produced. At this time, the surface of the amorphous PET base material 6 is corona-treated by the surface modification treatment apparatus 23 to improve the adhesion between the amorphous PET base material 6 and the PVA layer 2 formed on the amorphous PET base material 6. Can be done.

Next, the laminate 7 containing the PVA layer is finally produced as a polarizing film having a thickness of 3 μm through the following treatments including a two-stage stretching treatment of auxiliary stretching in the air and stretching in boric acid in water.

[Aerial auxiliary stretching treatment (B)]
In the first-stage aerial auxiliary stretching treatment (B), the laminated body 7 containing the 7 μm-thick PVA layer 2 is stretched integrally with the PET base material 6, and the “stretched laminated body 8” containing the 5 μm-thick PVA layer 2 is formed. Generate. Specifically, in the aerial auxiliary stretching treatment device 30 in which the stretching means 31 is provided in the oven 33, the laminate 7 including the PVA layer 2 having a thickness of 7 μm is stretched in the oven 33 set to a stretching temperature environment of 130 ° C. It is stretched uniaxially at the free end so that the stretching ratio becomes 1.8 times through the means 31, and the stretched laminate 8 is produced. At this stage, the roll 8'of the stretched laminate 8 can be manufactured by the winding device 32 installed in the oven 30.

[Dyeing process (C)]
Next, the dyeing treatment (C) produces a colored laminate 9 in which iodine, which is a dichroic substance, is adsorbed on the 5 μm-thick PVA layer 2 in which PVA molecules are oriented. Specifically, in the dyeing apparatus 40 provided with the dyeing bath 42 of the dyeing solution 41, the stretched laminate 8 unwound from the feeding device 43 equipped with the roll 8'attached to the dyeing device 40 is iodine at a liquid temperature of 30 ° C. The stretched laminate 8 is immersed in a dyeing solution 41 containing potassium iodide for an arbitrary time so that the single transmittance of the PVA layer constituting the finally produced polarizing film is 40 to 44%. A colored laminate 9 in which iodine is adsorbed on the oriented PVA layer 2 is produced.

In this treatment, the dyeing solution 41 uses water as a solvent and has an iodine concentration of 0.30% by weight in order to prevent the PVA layer 2 contained in the stretched laminate 8 from being dissolved. Further, the staining solution 41 has a potassium iodide concentration of 2.1% by weight for dissolving iodine in water. The ratio of iodine to potassium iodide concentrations is 1: 7. More specifically, a 5 μm-thick PVA layer in which PVA molecules are oriented by immersing the stretched laminate 8 in a staining solution 41 having an iodine concentration of 0.30% by weight and a potassium iodide concentration of 2.1% by weight for 60 seconds. A colored laminate 9 in which iodine is adsorbed on 2 is produced.

[Boric acid water stretching treatment (D)]
The colored laminate 9 containing the iodine-oriented PVA layer 2 is further stretched by the second-stage boric acid water stretching treatment, and the optical film laminate containing the iodine-oriented PVA layer constituting the polarizing film having a thickness of 3 μm is further stretched. Generate body 60. Specifically, in the boric acid water stretching treatment device 50 provided with the boric acid bath 52 of the boric acid aqueous solution 51 and the stretching means 53, the colored laminate 9 continuously unwound from the dyeing device 40 is boric acid and iodide. It is immersed in a boric acid aqueous solution 51 containing potassium and set in a stretching temperature environment at a liquid temperature of 65 ° C., and then applied to a stretching means 53 provided in a boric acid aqueous treatment apparatus 50 so that the stretching ratio becomes 3.3 times. By stretching uniaxially at the free end, an optical film laminate 60 containing a PVA layer having a thickness of 3 μm is produced.

[Washing process (G)]
Next, the optical film laminate 60 including the polarizing film is preferably sent to the cleaning treatment (G) as it is. The purpose of the cleaning treatment (G) is to wash away unnecessary residues adhering to the surface of the polarizing film with the cleaning liquid 81 of the cleaning apparatus 80. However, the cleaning treatment (G) can be omitted, and the optical film laminate 60 including the removed polarizing film can be directly sent to the drying treatment (H).

[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 as a continuous web optical film laminate 60 by a winding device 91 attached to the drying apparatus 90, and a roll of the optical film laminate 60 including a polarizing film is rolled. Will be generated. As the drying treatment (H), any suitable method, for example, natural drying, blast drying, or heat drying can be adopted. For example, in the oven drying device 90, drying can be performed with warm air at 60 ° C. for 240 seconds.

2-1-3. Others The polarizing film preferably contains zinc. Since the polarizing film contains zinc, the decrease in transmittance and the deterioration of hue of the polarizing film laminate after the heating test tend to be suppressed. When the polarizing film contains zinc, the zinc content in the polarizing film is preferably 0.002 to 2% by weight, more preferably 0.01 to 1% by weight.

The polarizing film also preferably contains sulfate ions. Since the polarizing film contains sulfate ions, a decrease in the transmittance of the polarizing film laminate after the heating test tends to be 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 0.1 to 0.1 to 0.35% by weight. 0.25% by weight is more preferable. The content of sulfate ions in the polarizing film is calculated from the sulfur atom content.

In order to contain zinc in the polarizing film, it is preferable that zinc impregnation treatment is performed in the polarizing film manufacturing process. Further, in order to contain sulfate ions in the polarizing film, it is preferable that sulfate ion treatment is performed in the polarizing film manufacturing process.

The zinc impregnation treatment is performed, for example, by immersing a PVA-based film in a zinc salt solution. As the zinc salt, an inorganic salt compound in an aqueous solution such as zinc halide such as zinc chloride and zinc iodide, zinc sulfate and zinc acetate is suitable. Further, various zinc complex compounds may be used for the zinc impregnation treatment. Further, as the zinc salt solution, it is preferable to use an aqueous solution containing potassium ions and iodine ions with potassium iodide or the like because it is easy to impregnate the zinc ions. The potassium iodide concentration in the zinc salt solution is preferably about 0.5 to 10% by weight, more preferably 1 to 8% by weight.

Sulfate ion treatment is performed, for example, by immersing a PVA-based film in an aqueous solution containing a metal sulfate. The metal sulfate is preferably one in which the sulfate ion and the metal ion are easily separated in the treatment liquid, and the metal sulfate is easily introduced into the PVA-based film in the ion state. For example, the types of metals that form metal sulfates include alkali metals such as sodium and potassium; alkaline earth metals such as magnesium and calcium; transitions such as cobalt, nickel, zinc, chromium, aluminum, copper, manganese, and iron. Metal is mentioned.

In the production of the 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 the dyeing treatment or after the dyeing treatment. The zinc impregnation treatment and the sulfate ion treatment may be performed at the same time. It is preferable that the zinc impregnation treatment and the sulfate ion treatment are simultaneously performed by immersing the PVA-based film in a treatment bath containing zinc sulfate using zinc sulfate as the zinc salt and the metal sulfate. Further, the zinc salt and the metal sulfate can be allowed to coexist in the dyeing solution, and the zinc impregnation treatment and / or the sulfate ion treatment can be performed at the same time as the dyeing treatment. The zinc impregnation treatment and the sulfate ion treatment may be performed at the same time as the stretching.

2-2. Polarizing film protective film 2-2-1. Polarizing film protective film located on the side opposite to the viewing side In the polarizing film laminate 12 of FIG. 1, as a material constituting the polarizing film protective film 122 located on the side opposite to the viewing side of the polarizing film 120, for example, , A thermoplastic resin 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, polyether sulfone-based resins, polysulfone-based resins, polycarbonate-based resins, polyamide-based resins, polyimide-based resins, and polyolefin-based resins. , (Meta) acrylic resin, cyclic polyolefin resin (norbornen resin), polyarylate resin, polystyrene resin, PVA resin, and mixtures thereof.
The polarizing film protective film 122 may also have the function of a retardation film.

The thickness of the polarizing film protective film 122 is appropriately adjusted in order to adjust the water content of the polarizing film laminate. From the viewpoint of workability such as strength and handleability, thin layer property, etc., about 1 to 500 μm is preferable, 2 to 300 μm is more preferable, and 5 to 200 μm is further preferable.
The polarizing film protective film 122 may contain one or more kinds of arbitrary additives. Examples of additives include ultraviolet absorbers, antioxidants, lubricants, plasticizers, mold release agents, color retardants, flame retardants, nucleating agents, antistatic agents, pigments, colorants and the like.

2-2-2. Polarizing film protective 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 containing an ultraviolet absorber, but it is sufficient if the transmittance for ultraviolet rays can be set to a desired value. It is not always necessary to use an ultraviolet absorber. For example, an ultraviolet absorbing filter may be used instead of the ultraviolet absorber to obtain a desired transmittance. When only the polarizing film protective film 121 is used as the light absorption layer, for example, the transmittance at a wavelength of 380 nm is preferably 5% or less, more preferably 3% or less, still more preferably 2% or less. The lower limit is, for example, 0.1% or more and 1% or more. The transmittance at a wavelength of 390 nm is preferably 35% or less, more preferably 30% or less, still more preferably 28% or less. The lower limit is, for example, 10% or more, 20% or more, and 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, 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 and 85% or more. In addition to ultraviolet absorbers, phthalocyanine-based light absorbers, naphthalocyanine-based light absorbers, polymethine-based light absorbers, diphenylmethane-based light absorbers, triphenylmethane-based light absorbers, quinone-based light absorbers, and azo-based light absorbers. An infrared absorber such as a light absorber may be mixed.

As the polarizing film protective film 121, for example, the configurations shown in FIGS. 3A to 3C can be adopted. Any of the polarizing film protective films 121A to C shown in FIGS. 3A to 3C can be used as the polarizing film protective film 121 shown in FIG. For convenience, in addition to the polarizing film protective films 121A to C, the polarizing film 120 and the polarizing film protective film 122 shown in FIG. 1 are also shown in these figures.

(A) Polarizing film protective film 121A
The polarizing film protective film 121A shown in FIG. 3A includes a polarizing film protective film layer 121A-1 and a coating layer 121A-2. The polarizing film protective film 121A having a light absorbing ability is obtained, for example, by containing a light absorbing agent in the polarizing film protective film layer 121A-1 and / or by containing a light absorbing agent in the coating layer 121A-2. Can be formed.

Examples of the material constituting the polarizing film protective film layer 121A-1 include a thermoplastic resin 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, polyether sulfone-based resins, polysulfone-based resins, polycarbonate-based resins, polyamide-based resins, polyimide-based resins, and polyolefin-based resins. , (Meta) acrylic resin, cyclic polyolefin resin (norbornen resin), polyarylate resin, polystyrene resin, PVA resin, and mixtures thereof. The polarizing film protective film may have the function of a retardation film.
The thickness of the polarizing film protective film layer 121A-1 is appropriately adjusted in order to adjust the water content of the polarizing film laminate 12. It is 20 to 60 μm, preferably 30 to 50 μm from the viewpoint of workability such as strength and handleability, and thin layer property.
One or more kinds of arbitrary additives may be contained in the polarizing film protective film layer 121A-1. Examples of the additive include antioxidants, lubricants, plasticizers, mold release agents, colorants, flame retardants, nucleating agents, antistatic agents, pigments, colorants and the like.
Examples of the light absorber contained in the polarizing film protective film layer 121A-1 include benzotriazole-based, benzophenone-based, salicylate phenyl ester-based, and triazine-based ultraviolet absorbers. Examples of the benzotriazole-based ultraviolet absorber include 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- (2H-benzotriazole-2-yl) -p-cresol, and 2- (2H-benzotriazole). -2-yl) -4,6-di-tert-pentylphenol, 2- (2'-hydroxy-5'methacryloxyethylphenyl) -2H-benzotriazole and the like can be mentioned. Examples of the benzophenone-based ultraviolet absorber include 2-hydroxy-4-octoxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxy-4'-chlorobenzophenone, and 2,2-dihydroxy-4-methoxy. Benzophenone, 2,2-dihydroxy-4,4'-dimethoxybenzophenone and the like can be mentioned. Examples of the salicylic acid phenyl ester-based ultraviolet absorber include pt-butylphenyl salicylate ester and the like. Examples of the triazine-based ultraviolet absorber include 2,4-diphenyl-6- (2-hydroxy-4-methoxyphenyl) -1,3,5-triazine and 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-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 absorbers can be contained by mixing in a polarizing film protective film.

Specific examples of the coating layer 121A-2 include a hard coat layer, an anti-glare layer, an anti-blocking layer, an antireflection layer, a conductive layer and the like. Among them, the production method of the present invention is particularly useful when forming a hard coat layer. Materials constituting the coating layer include resin materials (monomers, oligomers, prepolymers and / or polymers). In one embodiment, the resin material comprises a thermosetting or photocurable curable compound. A hard coat layer or an anti-glare layer can be formed by using a coating layer material containing a curable compound. The curable compound may be any of a monomer, an oligomer and a prepolymer. A polyfunctional monomer or oligomer can be used as the curable compound, for example, a monomer or oligomer having two or more (meth) acryloyl groups, a urethane (meth) acrylate or a urethane (meth) acrylate oligomer, an epoxy-based monomer or Examples thereof include oligomers, silicone-based monomers and oligomers.
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 and the like. The lower limit is, for example, 1 μm or more, 2 μm or more, and 4 μm or more.
Examples of the light absorber contained in the coating layer 121A-2 include benzotriazole-based, benzophenone-based, salicylic acid phenyl ester-based, and triazine-based ultraviolet absorbers. Examples of the benzotriazole-based ultraviolet absorber include 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- (2H-benzotriazole-2-yl) -p-cresol, and 2- (2H-benzotriazole). -2-yl) -4,6-di-tert-pentylphenol, 2- (2'-hydroxy-5'methacryloxyethylphenyl) -2H-benzotriazole and the like can be mentioned. Examples of the benzophenone-based ultraviolet absorber include 2-hydroxy-4-octoxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxy-4'-chlorobenzophenone, and 2,2-dihydroxy-4-methoxy. Benzophenone, 2,2-dihydroxy-4,4'-dimethoxybenzophenone and the like can be mentioned. Examples of the salicylic acid phenyl ester-based ultraviolet absorber include pt-butylphenyl salicylate ester and the like. Examples of the triazine-based ultraviolet absorber include 2,4-diphenyl-6- (2-hydroxy-4-methoxyphenyl) -1,3,5-triazine and 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-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 absorbers can be contained by mixing with the resin forming the coating layer.

In order to achieve the above transmittance, the total thickness of the light absorbing layer composed of the polarizing film protective film layer 121A-1 and / or the coating layer 121A-2, that is, the polarizing film protection having a light absorbing ability The total thickness of the film layer 121A-1 and / or the coating layer 121A-2 having a light absorbing ability is 25 to 65 μm, preferably 35 to 55 μm from the viewpoint of obtaining sufficient light absorbing ability and thinning property. Hereinafter, it is more preferably 40 to 50 μm.

(B) Polarizing film protective film 121B
The polarizing film protective film 121B shown in FIG. 3 (b) includes a plurality of polarizing film protective film layers 121B-1 and 121B-3, and these polarizing film protective film layers 121B-1 and 121B-. Includes an adhesive layer 121B-2 to which 3 is bonded. The polarizing film protective film 121B having a light absorbing ability can be formed, for example, by including a light absorbing agent in either or both of the polarizing film protective film layers 121B-1 and 121B-3.

As the material constituting the polarizing film protective film layers 121B-1 and 121B-3, the same material as the optical film protective film layer 121A-1 can be used.
Further, as the light absorber contained in the polarizing film protective film layers 121B-1 and 121B-3, the same light absorber contained in the polarizing film protective film layer 121A-1 can be used. These light absorbers can be contained in the same manner as the polarizing film protective film layer 121A-1.

In order to achieve the above transmittance, the total thickness of the light absorbing layer composed of the polarizing film protective film layers 121B-1 and 121B-3, that is, the polarizing film protective film layer 121B-1 having a light absorbing ability, The total thickness of 121B-3 is 25 to 105 μm, preferably 60 to 100 μm, and more preferably 70 to 90 μm from the viewpoint of obtaining sufficient light absorption capacity and thin layer property.

As the adhesive layer 121B-2, for example, an ultraviolet curable adhesive or a dope curable adhesive, which will be described later, can be used.

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

As the material constituting the polarizing film protective film layer 121C, the same material as that of the optical film protective film layer 121A-1 can be used.
Further, as the light absorber contained in the polarizing film protective film layer 121C, the same light absorber contained in the polarizing film protective film layer 121A-1 can be used. These light absorbers can be contained in the same manner as the polarizing film protective film layer 121A-1.

The thickness of the polarizing film protective film layer 121C, that is, the thickness as a light absorption layer is 25 to 105 μm, preferably 60 to 100 μm, more preferably 70 to 90 μm from the viewpoint of obtaining sufficient light absorption ability and thin layer property. Is. The polarizing film protective film layer 121C can also be regarded as a combination of the plurality of polarizing film protective films 121B-1 and 121B-3 shown in FIG. 3B.

2-2-3. In addition, any of the cover plate 14, the transparent adhesive 13, and the polarizing film protective film 121 may be used, or a combination thereof may be used to form a light absorption layer. When a plurality of layers are combined to form a light absorption layer, the desired transmittance may be appropriately adjusted for the entire device as in the case of a general device.

2-3. The other optical film The polarizing film and the polarizing film

protective films

121 and 122 may be directly bonded or laminated with another optical film. The other optical film is not particularly limited, but for example, a retardation film, a viewing angle compensation film, or the like can be used. The retardation film as another optical film may have a function as a protective film.

As described above, the polarizing film

protective films

121 and 122 may have the function of a retardation film, but in this case, the retardation film as another optical film may be omitted. On the other hand, even when the polarizing film protective film also has the function of the retardation film, the retardation film can be provided as another optical film. In this case, substantially two or more retardation films will be included.

2-4. Adhesive The adhesive used to bond the adhesive layer 121B-2 shown in FIG. 3B, the polarizing film 120 and the polarizing film

protective films

121 and 122, or other optical films such as a retardation film and them. As the adhesive used for bonding with, for example, a radical polymerization curable (ultraviolet curable) adhesive, a cationic polymerization curable adhesive, or an aqueous (dope type) adhesive can be used.

(Radical polymerization curing type adhesive)
The radical polymerization curable adhesive contains a radical polymerizable compound as a curable compound. The radically polymerizable compound may be a compound that is cured by active energy rays or a compound that is cured by heat. Examples of the active energy ray include an electron beam, ultraviolet rays, visible light and the like.

Examples of the radically polymerizable compound include compounds having a radically polymerizable functional group having a carbon-carbon double bond such as a (meth) acryloyl group and a vinyl group. As the radically polymerizable compound, a polyfunctional radically polymerizable compound is preferably used. Only one type of radically polymerizable compound may be used alone, or two or more types may be used in combination. Further, the polyfunctional radical polymerizable compound and the monofunctional radical polymerizable compound may be used in combination.

As the polymerizable compound, it is preferable to use a compound having a high logP value (octanol / water partition coefficient), and as the radical polymerizable compound, it is preferable to select a compound having a high logP value. Here, the logP value is an index showing the lipophilicity of a substance, and means a logarithmic value of the partition coefficient of octanol / water. A high logP value means that it is lipophilic, that is, it has a low water absorption rate. The logP value can be measured (the flask dipping method described in JIS-Z-7260), and is calculated based on the structure of each compound which is a constituent component (curable component, etc.) of the curable adhesive. It can also be calculated (ChemDraw Ultra manufactured by Cambridge Soft).

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

Examples of the polyfunctional radical polymerizable compound include tripropylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and 1,9-nonanediol di (). Meta) 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 Propropylene oxide adduct Di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, neopentyl glycol di (meth) acrylate, tricyclodecanedimethanol di (meth) acrylate, cyclic trimethyl propanformal (meth) Acrylate, dioxane glycol di (meth) acrylate, trimethylpropantri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) ) Acrylate, esterified product of (meth) acrylate such as EO-modified diglycerin tetra (meth) acrylate and polyhydric alcohol; 9,9-bis [4- (2- (meth) acryloyloxyethoxy) phenyl] fluorene; epoxy Examples thereof include (meth) acrylate; urethane (meth) acrylate; polyester (meth) acrylate and the like.

Among the polyfunctional radical polymerizable compounds, a polyfunctional radical polymerizable compound having a high logP value is preferable. Examples of such compounds include alicyclic (meth) acrylates such as tricyclodecanedimethanol di (meth) acrylate (logP = 3.05) and isobornyl (meth) acrylate (logP = 3.27); Long-chain aliphatic (meth) acrylates such as 9-nonanediol di (meth) acrylate (logP = 3.68), 1,10-decanediol diacrylate (logP = 4.10); neopentyl glycol hydroxypivalate ( Multi-branched (meth) acrylates such as meta) acrylic acid adduct (logP = 3.35), 2-ethyl-2-butylpropanediol di (meth) acrylate (logP = 3.92); bisphenol A di (meth) Acrylate (logP = 5.46), Di (meth) acrylate with 4 mol of bisphenol A ethylene oxide (logP = 5.15), Di (meth) acrylate with 2 mol of bisphenol Apropylene oxide (logP = 6.10) , Bisphenol Apropylene oxide 4 mol Additive Di (meth) acrylate (logP = 6.43), 9,9-bis [4- (2- (meth) acryloyloxyethoxy) phenyl] fluorene (logP = 7.48) , (Meta) acrylate containing an aromatic ring such as p-phenylphenol (meth) acrylate (logP = 3.98) and the like.

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

Examples of the monofunctional radically polymerizable compound include (meth) acrylamide derivatives having a (meth) acrylamide group. By using the (meth) acrylamide derivative, a pressure-sensitive adhesive layer having excellent adhesiveness can be formed with high productivity. Specific examples of the (meth) acrylamide derivative include N-methyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, and N. -N-alkyl group-containing (meth) acrylamide derivatives such as butyl (meth) acrylamide and N-hexyl (meth) acrylamide; N-methylol (meth) acrylamide, N-hydroxyethyl (meth) acrylamide, N-methylol-N- N-hydroxyalkyl group-containing (meth) acrylamide derivatives such as propane (meth) acrylamide; N-aminoalkyl group-containing (meth) acrylamide derivatives such as aminomethyl (meth) acrylamide and aminoethyl (meth) acrylamide; N-methoxymethyl N-alkoxy group-containing (meth) acrylamide derivatives such as acrylamide and N-ethoxymethylacrylamide; N-mercaptoalkyl group-containing (meth) acrylamide derivatives such as mercaptomethyl (meth) acrylamide and mercaptoethyl (meth) acrylamide can be mentioned. .. Further, as a heterocyclic-containing (meth) acrylamide derivative in which the nitrogen atom of the (meth) acrylamide group forms a heterocycle, for example, N-acrylloylmorpholine, N-acrylloylpiperidin, N-methacryloylpiperidin, N-acrylloylpyridine and the like. May be used. Among these, an N-hydroxyalkyl group-containing (meth) acrylamide derivative is preferable, and N-hydroxyethyl (meth) acrylamide is more preferable.

Further, as the monofunctional radical polymerizable compound, a (meth) acrylic acid derivative having a (meth) acryloyloxy group; (meth) acrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, croton. Carboxyl group-containing monomers such as acid and isocrotonic acid; lactam-based vinyl monomers such as N-vinylpyrrolidone, N-vinyl-ε-caprolactam and methylvinylpyrrolidone; vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole , Vinyl imidazole, vinyl oxazole, vinyl morpholin, and other vinyl-based monomers having a nitrogen-containing heterocycle may be used.

When the polyfunctional radical polymerizable compound and the monofunctional radical polymerizable compound are used in combination, the content ratio of the monofunctional radical polymerizable is preferably 3 to 80% by weight based on the total amount of the radical polymerizable compound, and 5 to 50% by weight. By weight% is more preferred, 8 to 25% by weight is even more preferred, and 8 to 20% by weight is particularly preferred. Within such a range, a polarizing film having excellent durability under high temperature and high humidity can be obtained.

The radical polymerization curable adhesive may further contain other additives. When the radical polymerization curable adhesive contains a curable compound that is cured by active energy rays, the adhesive may further contain, for example, a photopolymerization initiator, a photoacid generator, a silane coupling agent, and the like. When the radical polymerization curable adhesive contains a curable compound that is cured by heat, the adhesive may further contain a thermal polymerization initiator, a silane coupling agent, and the like. In addition, examples of other additives include polymerization inhibitors, polymerization initiators, leveling agents, wettability improvers, surfactants, plasticizers, ultraviolet absorbers, inorganic fillers, pigments, dyes and the like. ..

(Cynic polymerization curable adhesive)
The cationically polymerizable curable adhesive contains a cationically polymerizable compound as a curable compound. Examples of the cationically polymerizable compound include compounds having an epoxy group and / or an oxetanyl group. As the compound having an epoxy group, a compound having at least two epoxy groups in the molecule is preferably used. Examples of the compound having an epoxy group include a compound having at least two epoxy groups and at least one aromatic ring (aromatic epoxy compound), and at least two epoxy groups in the molecule, of which at least. One is a compound (alicyclic epoxy compound) formed between two adjacent carbon atoms constituting an alicyclic ring.

The cationic polymerization curable adhesive preferably contains a photocationic polymerization initiator. The photocationic polymerization initiator generates a cationic species or Lewis acid by irradiation with active energy rays such as visible light, ultraviolet rays, X-rays, and electron beams, and initiates a polymerization reaction of an epoxy group or an oxetanyl group. In addition, the cationic polymerization curable adhesive may further contain the above-mentioned additive.

(Aqueous adhesive)
Examples of the water-based adhesive include aqueous solutions of water-based adhesives such as isocyanate-based adhesives, PVA-based adhesives, gelatin-based adhesives, vinyl-based latex-based adhesives, and water-based polyesters (for example, solid content concentration of 0.5 to 60% by weight). ) Is preferably used.

The adhesive may be applied to any of the polarizing film 120, the polarizing film

protective films

121 and 122, and other optical films, or both of them. Generally, a method in which the polarizing film is immersed in an aqueous adhesive solution and then laminated with the polarizing film

protective films

121 and 122 by a roll laminator or the like is preferable. The thickness of the adhesive layer is not particularly limited, but is, for example, about 30 nm to 1000 nm after drying.

After the polarizing film, the polarizing film protective film, and other optical films are laminated via an adhesive, this laminate is subjected to a drying treatment. In this step of drying the laminated body, in addition to the purpose of drying and solidifying the adhesive, the purpose is to reduce the amount of water that improves the initial optical characteristics of the polarizing film laminated body. As a drying method, heat drying is common. The drying conditions are preferably in the range of 50 to 95 ° C and more preferably in the range of 60 to 85 ° C.

The drying conditions of the laminate are not particularly limited, but considering the efficiency and practicality of the treatment, the drying temperature is preferably 50 ° C. or higher, and 95 from the viewpoint of making the optical characteristics of the polarizing film laminate uniform. ℃ or less is preferable. The drying temperature can be raised stepwise within the above temperature range.

The laminate can be dried continuously with the bonding treatment of the polarizing film, the polarizing film protective film, and other optical films. Further, after the laminate of the polarizing film, the polarizing film protective film, and other optical films is once wound in a roll state, drying may be performed as another treatment.

Generally, in order to reduce the water content of the polarizing film laminate, high temperature and long-term drying conditions are required. Drying at a high temperature for a long time is preferable from the viewpoint of reducing the water content of the polarizing film laminate, but on the other hand, it may lead to deterioration of the optical characteristics of the polarizing film laminate. By using a polarizing film protective film having a small saturated water absorption and a polarizing film protective film having a high moisture permeability, the water content of the polarizing film laminate can be adjusted within the desired range without adopting harsh drying conditions. Can be done.

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

3. 3. Reliability evaluation items Multiple phenomena that can occur in the polarizing film laminate, that is, polyene formation, color loss, and heating red discoloration, are evaluated. The mechanism by which each phenomenon occurs is not always clear, but it is presumed to be roughly as follows.

<Polyene>
In a high temperature and high humidity environment, the single transmittance of the polarizing film laminate decreases. Further, even when light is irradiated in the ultraviolet region or the visible light region, the single transmittance of the polarizing film laminate is similarly lowered. This decrease is presumed to be due to polyene formation of PVA. The polyene refers to − (CH = CH) _n − and can be formed in the polarizing film by heating or light energy. Polyenes significantly reduce the transmittance of the polarizing film. Further, in the light irradiation environment of high temperature and high humidity environment or the ultraviolet region and the visible light region is destroyed PVA- polyiodine complex I ^- and I ₂ are likely to be generated.
_{As shown in Chemical Formula 1 below, PVA is polyene-ized by the iodine (I 2} ) generated in a high-temperature and high-humidity environment or in a light irradiation environment in the ultraviolet region or visible light region, and heating or light energy. It is thought to occur when the dehydration reaction is promoted.
(Chemical formula 1)

_{I 2} generated when the PVA-polyiodine complex existing in the polarizing film is broken by heating or light energy and the OH group in PVA form a charge transfer complex (HO ... I ₂ ), and then the OI group is formed. It is thought that it will become polyene via.

<Color loss>
It is iodine staining, and the stretched PVA-based film (polarizer), iodine I ₃ ^- and I ₅ ^- in the form of a polyiodine ion, to form a oriented PVA complexes (PVA polyiodine complex ). At this time, the PVA has a cross-linking point formed by a cross-linking agent such as boric acid, whereby the orientation is maintained.
However, when the polarizing film is placed in a high temperature and high humidity environment or in a light irradiation environment in an ultraviolet region or a visible light region, hydrolysis of boric acid crosslinks occurs, the orientation of PVA decreases, and the PVA polyiodine complex Collapse occurs. As a result, the visible light absorption based on the PVA polyiodine complex is reduced, and the transmittance on the long wavelength side of about 700 nm and the short wavelength side of about 410 nm is increased. In this way, in a polarizing film placed in a high temperature and high humidity environment or in a light irradiation environment in an ultraviolet region or a visible light region, color loss occurs in a black display.

<Heating redness>
Is iodine staining, and the stretched PVA-based film (polarizer), iodine I ₃ ^- and I ₅ ^- polyiodide in the form of iodine ions to form a PVA complexes (PVA polyiodine complex) of. I ₃ ^- has a broad absorption peak near 470 nm, and I ₅ ^- has a broad absorption peak near 600 nm. That is, the PVA-I ₃ ^- complex is responsible for absorption on the short wavelength side (blue side), and the PVA-I ₅ ^- complex is responsible for absorption on the long wavelength side (red side).
However, the PVA-I ₅ ^- complexes weakly to the heat or light energy, the polarizing film and a high temperature, when placed under light irradiation environment in the ultraviolet region or visible region PVA and I ₅ ^- is complexation with collapse, I ₅ ^- would decompose.
Therefore, in a polarizing film placed at a high temperature or in a light irradiation environment in an ultraviolet region or a visible light region, the PVA-I ₅ ^- complex responsible for absorption on the long wavelength side is reduced, that is, the length is about 700 nm. The transmittance on the wavelength side increases, and the polarizing film turns red.

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

<Film thickness of polarizing film>
The film 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. As the solvent, for example, dichloromethane is used when the polarizing film protective film is a triacetyl cellulose resin, cyclohexane is used when the polarizing film protective film is a cycloolefin resin, and methyl ethyl ketone is used when the polarizing film protective film is an acrylic resin. , Can be used respectively. If the resin of the polarizing film protective film provided on one surface of the polarizing film and the resin of the polarizing film protective film provided on the other surface are different, the respective resins are used as the above-mentioned solvent. Dissolve in sequence using.

<Iodine concentration of polarizing film>
The iodine concentration (wt.%) Of the polarizing film can be changed, for example, by adjusting the concentration of the iodine aqueous solution for immersing the PVA-based film or the PVA layer and the immersion time during the production of the polarizing film.
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 when measuring the film thickness of the polarizing film.
(Fluorescent X-ray measurement)
When measuring the iodine concentration of the polarizing film, first, the iodine concentration is quantified by using the calibration curve method of fluorescent X-ray analysis. A fluorescent X-ray analyzer ZSX-PRIMUS IV (manufactured by Rigaku Co., Ltd.) is used as the apparatus.
The value directly obtained by the fluorescent X-ray analyzer is not the concentration of each element, but the fluorescent X-ray intensity (kcps) of the wavelength peculiar to each element. Therefore, in order to determine the iodine concentration contained in the polarizing film, it is necessary to convert the fluorescent X-ray intensity into a concentration using a calibration curve. The iodine concentration of the polarizing film in the present specification and the like means the iodine concentration (wt%) based on the weight of the polarizing film.

(Creation of calibration curve)
Create a calibration curve according to the following procedure.
1. 1. A known amount of potassium iodide was dissolved in a PVA aqueous solution to prepare 7 kinds of PVA aqueous solutions containing iodine having a known concentration. This PVA aqueous solution is applied to polyethylene terephthalate, dried, and then peeled off to prepare samples 1 to 7 of PVA films containing iodine having a known concentration.
The iodine concentration (wt%) of the PVA film is calculated by the following formula 1.
[Formula 1] Iodine concentration (wt%) = {potassium iodide amount (g) / (potassium iodide amount (g) + PVA amount (g))} x (127/166)
(Molecular weight of iodine: 127 Molecular weight of potassium: 39)

2. The fluorescent X-ray intensity (kcps) corresponding to iodine is measured on the produced PVA film using a fluorescent X-ray analyzer ZSX-PRIMUS IV (manufactured by Rigaku Co., Ltd.). The fluorescent X-ray intensity (kcps) is the peak value of the fluorescent X-ray spectrum. Further, the film thickness of the produced PVA film is measured using a spectroscopic film thickness meter MCPD-1000 (manufactured by Otsuka Electronics Co., Ltd.).

3. The fluorescent X-ray intensity is divided by the thickness of the PVA film (μm) to obtain the fluorescent X-ray intensity per unit thickness of the film (kcps / μm). Table 1 shows the iodine concentration of each sample and the fluorescent X-ray intensity per unit thickness.

4. Based on the results shown in Table 1, calibration is performed 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. Create a line. The prepared calibration curve is shown in FIG. Formula 2 is used to determine the iodine concentration from the fluorescent X-ray intensity per unit thickness of the PVA film from the calibration curve. R2 in FIG. 4 is a correlation coefficient.
[Formula 2]
(Iodine concentration) (wt%) = 14.474 × (fluorescent X-ray intensity per unit thickness of PVA film) (kcps / μm)

(Calculation of iodine concentration)
The fluorescent X-ray intensity obtained in the sample measurement is divided by the thickness to obtain the fluorescent X-ray intensity (kcps / μm) per unit thickness. The iodine concentration is obtained by substituting the fluorescent X-ray intensity per unit thickness of each sample into Equation 2.

<Moisture content of polarizing film laminate>
The water content (g / m ² ) of the polarizing film laminate can be determined mainly by adjusting the film thickness of the polarizing film, the material and thickness of the polarizing film protective film bonded to the polarizing film, and the like. It can also be adjusted by a cross-linking treatment (boric acid content, etc.) at the time of manufacturing the polarizing film.
The water content of the polarizing film laminate is measured by the following method.
First, the polarizing film laminates obtained in Examples and Comparative Examples are cut into a square of 0.1 m × 0.1 m.
The cut sample is placed in a constant temperature and humidity chamber and left for 48 hours in an environment with a temperature of 23 ° C. and a relative humidity of 55%. Then, the sample is taken out in the same environment as in the constant temperature and humidity chamber, that is, in a clean room set to a temperature of 23 ° C. and a relative humidity of 55%, and the weight is measured within 5 minutes after taking out. The sample weight at this time is defined as the initial weight W1 (g). If it is within about 15 minutes after taking out, even if the temperature in the clean room fluctuates by about 2 ° C to 3 ° C, or even if the relative humidity in the clean room fluctuates by about ± 10%, the initial weight Has no substantial effect on.
Next, the taken-out sample is put into a dryer and dried at 120 ° C. for 2 hours. Then, the sample dried in a clean room set to the above-mentioned temperature of 23 ° C. and relative humidity of about 55% is taken out, and the weight is measured within 10 minutes after taking out. The sample weight at this time is the weight W2 (g) after drying. Unlike the above, the reason why it is set within 10 minutes instead of within 5 minutes is in consideration of the cooling time. As in the above, if it is within about 15 minutes after taking out, the weight after drying is not substantially affected.
From the initial weight W1 of the sample thus obtained and the weight W2 after drying, the equilibrium water content M (g / m ² ) of the polarizing film laminate is calculated from the following formula.
(Equation) M = (W1-W2) / (0.1 × 0.1)
The "moisture content of the polarizing film laminate" as used in the present invention means the equilibrium moisture content calculated by the above method.

<Light absorption capacity>
In order to evaluate the effect of suppressing the influence of short-wavelength light, the polarizing film protection located on the visual side of the polarizing film according to the JIS-Z-8701 color display method for each of the wavelengths of 380 μm, 390 μm, 400 μm, and 420 μm The transmittance of the film was measured. For the measurement, U-4100 manufactured by Hitachi, Ltd. was used.

[Example 1]
(Creation of polarizing film)
As the resin base material, a long amorphous isophthalic copolymerized polyethylene terephthalate film (isophthalic acid group modification degree 5 mol%, thickness: 100 μm) was used. (Degree of polymerization = ethylene isophthalate unit / (ethylene terephthalate unit + ethylene isophthalate unit)) One surface of the resin base material is subjected to corona treatment (treatment condition: 55 W · min / m2), and the corona treated surface is subjected to corona treatment. PVA blended with 90 parts by weight of PVA (degree of polymerization 4200, degree of saponification 99.2 mol%) and 10 parts by weight of acetoacetyl-modified PVA (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "Gosefimer Z410") and PVA. An aqueous solution containing potassium iodide so as to be 13 parts by weight was applied at room temperature. Then, it was dried at 60 ° C. to form a PVA-based resin layer having a thickness of 13 μm, and a laminate was prepared.
The obtained laminate was stretched 2.4 times in the longitudinal direction (longitudinal direction) between rolls having different peripheral speeds in an oven at 130 ° C. (aerial auxiliary stretching).
Next, the laminate was immersed in an insolubilizing bath at a liquid temperature of 40 ° C. (an aqueous boric acid solution obtained by blending 4 parts by weight of boric acid with 100 parts by weight of water) for 30 seconds (insolubilization treatment).
Next, a dyeing bath having a liquid temperature of 30 ° C. (an aqueous iodine solution obtained by mixing iodine and potassium iodide in a weight ratio of 1: 7 with respect to 100 parts by weight of water) so as to have a specified transmittance. It was immersed for 60 seconds while adjusting the concentration (dyeing treatment).
Next, it was immersed in a cross-linked bath at a liquid temperature of 40 ° C. (an aqueous boric acid solution obtained by blending 3 parts by weight of potassium iodide and 5 parts by weight of boric acid with respect to 100 parts by weight of water) for 30 seconds. (Crossing treatment).
Then, while immersing the laminate in a boric acid aqueous solution (boric acid concentration 3.0% by weight) at a liquid temperature of 70 ° C., the total draw ratio is 5.5 in the longitudinal direction (longitudinal direction) between rolls having different peripheral speeds. Uniaxial stretching was performed so as to double (stretching in water).
Then, the laminate was immersed in a washing bath at a liquid temperature of 20 ° C. (an aqueous solution obtained by blending 4 parts by weight of potassium iodide with 100 parts by weight of water) (cleaning treatment).
Then, while drying (drying treatment) in an oven kept at 90 ° C., the metal roll made of SUS whose surface temperature was kept at 75 ° C. was brought into contact with the metal roll for 2 seconds or more (heat roll drying treatment).
In this way, a polarizing film having a thickness of 5.4 μm was obtained on the resin substrate.

(Creation of polarizing film laminate)
A polarizing film protective film is 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 visible side of the polarizing film). On the surface from which the resin base material has been peeled off (the other surface of the polarizing film, in other words, the surface on the visual side of the polarizing film), triacetyl cellulose containing a light absorber as a polarizing film protective film having a light absorbing ability. An ultraviolet curable type polarizing film protective film composed of a film (manufactured by Konica Minolta, trade name "KC4UY", thickness 40 μm) and a hard coat layer (thickness 5 μm) containing a light absorber arranged on the visible side thereof. They were joined via an adhesive. Specifically, the curable adhesive was coated so that the total thickness was 1.0 μm, and the adhesive was joined using a roll machine. Then, UV light is irradiated from the other surface side to cure the adhesive to obtain a polarizing film laminate containing a polarizing film and a polarizing film protective film having a light absorbing ability on the other surface of the polarizing film. It was.
The above-mentioned triacetyl cellulose film contains a predetermined amount of a light absorber (ultraviolet absorber). On the other hand, the hard coat layer is a light absorber Tinosorb S (manufactured by BASF) so that the triacetyl cellulose film and the entire hard coat layer have the transmittances shown in Tables 2 and 3 described later. Was contained.
The 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 acryloyl morpholine (ACMO), and 3 parts by weight of the photoinitiator "IRGACURE 819" (manufactured by BASF). The adhesive layer was applied onto a polarizing film so that the thickness of the adhesive layer after curing was 1.0 μm, and was irradiated with ultraviolet rays as active energy rays to cure the adhesive. For ultraviolet irradiation, gallium-filled metal halide lamp, irradiation device: Fusion UV Systems, Light HAMMER10 manufactured by Inc., valve: V valve, peak illuminance: 1600 mW / cm ² , cumulative irradiation amount 1000 / mJ / cm ² (wavelength 380 to 440 nm). ), And the illuminance of ultraviolet rays was measured using a Solar-Check system manufactured by Solartell.

(Measurement of iodine concentration)
By using cyclohexane as a solvent, the polarizing film was taken out from the polarizing film laminate, and the iodine concentration of the polarizing film was measured.

(Measurement of transmittance)
The polarizing film protective film located on the visual side of the polarizing film, that is, the polarizing film protective film composed of the triacetyl cellulose film and the hard coat layer is peeled off from the polarizing film laminate to increase the transmittance of the polarizing film protective film. It was measured.

[Example 2]
In the preparation of the polarizing film of Example 1, the concentration of the iodine aqueous solution and the immersion time were adjusted in the dyeing treatment to change the iodine concentration.
Further, when producing the polarizing film laminate of Example 1, a cycloolefin-based film (Zeonoa film, 13 μm, manufactured by Nippon Zeon Co., Ltd.) was applied as a polarizing film protective film on one surface of the polarizing film, and an ultraviolet curable adhesive was applied. It was joined through. Since this cycloolefin-based film is provided on one surface of the polarizing film, it does not affect the value of the light absorption capacity. On the other hand, the other surface of the polarizing film has the same configuration as the other surface of the first embodiment. In addition, the water content of the polarizing film laminate was changed.
Others are the same as in Example 1.

[Comparative Example 1]
In producing the polarizing film laminate of Example 1, one surface of the polarizing film has the same configuration as the above-mentioned one surface of Example 1, while the other surface of the polarizing film has a lactone ring structure. A transparent protective film (manufactured by Nitto Denko Co., Ltd.) having a thickness of 20 μm made of a modified acrylic polymer was applied through an ultraviolet curable adhesive in the same manner as in Example 1 so that the total thickness of the curable adhesive was 1.0 μm. It was joined. In addition, the water content of the polarizing film laminate was changed.
Others are the same as in Example 1.

[Comparative Example 2]
In producing the polarizing film laminate of Example 2, one surface of the polarizing film has the same configuration as the above one surface of Example 2, while the other surface of the polarizing film has a cycloolefin film (Japan). Zeon Co., Ltd., Zeonoa film, 25 μm) was bonded via an ultraviolet curable adhesive in the same manner as in Example 1 so that the total thickness of the curable adhesive was 1.0 μm. In addition, the water content of the polarizing film laminate was changed.
Others are the same as in Example 2.

[Comparative Example 3]
In the preparation of the polarizing film of Example 1, the concentration of the iodine aqueous solution and the immersion time were adjusted in the dyeing treatment to change the iodine concentration.
Further, in producing the polarizing film laminate of Example 1, a cycloolefin-based film (Zeonoa film, 17 μm, manufactured by Nippon Zeon Co., Ltd.) was used as a polarizing film protective film on one surface of the polarizing film. In the same manner, the curable adhesives were bonded via an ultraviolet curable adhesive so that the total thickness of the curable adhesive was 1.0 μm. On the other hand, the other surface of the polarizing film has the same configuration as the other surface of the first embodiment. Furthermore, the water content of the polarizing film laminate was changed.
Others are the same as in Example 1.

[Comparative Example 4]
In producing the polarizing film laminate of Comparative Example 3, one surface of the polarizing film had the same configuration as the above-mentioned one surface of Comparative Example 3. On the other hand, no polarizing film protective film was provided on the other surface of the polarizing film. In addition, the water content of the polarizing film laminate was changed.
Others are the same as in Comparative Example 3.

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

(Creation of polarizing film laminate)
As the adhesive, a dope-curable curable adhesive, more specifically, a polyvinyl alcohol resin containing an acetoacetyl group (average degree of polymerization 1200, saponification degree 98.5 mol%, acetoacetylation degree 5 mol%). An aqueous solution containing methylol melamine at a weight ratio of 3: 1 was used. Using this adhesive, a transparent protective film (manufactured by Nitto Denko KK) with a thickness of 20 μm made of a modified acrylic polymer having a lactone ring structure was bonded to one surface of a polarizing film under a temperature condition of 30 ° C. .. Specifically, the dope-curable adhesive was coated so as to have a total thickness of 1.0 μm, and bonded using a roll machine. On the other hand, on the other surface of the polarizing film, as a polarizing film protective film having a light absorbing ability, the polarizing film protective film used in Example 1, that is, a triacetyl cellulose film containing a light absorber, and a visible side thereof. The polarizing film protective film composed of the hard coat layer containing the light absorber arranged in the above was bonded not with the ultraviolet curable adhesive but with the same dope curable curable adhesive in the same manner as one surface. .. Then, it is heated and dried in an oven at 70 ° C. for 5 minutes to have a polarizing film and a polarizing film protective film having no light absorbing ability on one surface of the polarizing film and having light absorbing ability on the other surface. A polarizing film laminate having a polarizing film protective film was obtained.
(Measurement of iodine concentration)
By using dichloromethane and methyl ethyl ketone as solvents, the polarizing film was taken out from the polarizing film laminate, and the iodine concentration of the polarizing film was measured.

(Measurement of transmittance)
The transmittance was measured by the same method as in Example 1.

[Comparative Example 5]
In producing the polarizing film laminate of Example 3, one of the above surfaces has the same configuration as that of Example 3, and the other surface contains a light absorber as a polarizing film protective film having a light absorbing ability. A polarizing film protective film composed of an acetyl cellulose film (manufactured by Konica Minolta, trade name "KC2UA", thickness 25 μm) and a hard coat layer (manufactured by Nitto Denko Co., Ltd., thickness 9 μm) arranged on the visible side thereof that does not have light absorbing ability. Was joined via a dope-curable adhesive so that the total thickness of the curable adhesive was 1.0 μm in the same manner as in Example 3. In addition, the water 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 a resin solution in which an ultraviolet curable resin monomer or oligomer containing urethane acrylate as a main component is dissolved in butyl acetate (manufactured by DIC Corporation, trade name "Unidic 17-806". Solid content concentration 80% by weight). In addition, 5 parts by weight of a photopolymerization initiator (manufactured by BASF Co., Ltd., product name "IRGACURE906") and a leveling agent (manufactured by DIC Corporation, product name "GRANDIC PC4100") per 100 parts by weight of the solid content in the solution. ) Is added in an amount of 0.01 part by weight, and cyclopentanone (hereinafter referred to as “CPN”) and propylene glycol monomethyl ether (hereinafter referred to as “CPN”) are added to the above-mentioned compounding solution so that the solid content concentration in the solution becomes 36% by weight. It is made by adding (denoted as "PGM") in a ratio of 45:55. The hard coat layer forming material thus produced was coated on a transparent protective film so that the thickness of the hard coat after curing was 9 μm to form a coating film. Then, it was dried at 90 ° C. for 1 minute, and then irradiated with ultraviolet rays having an integrated light intensity of 300 mJ / cm2 with a high-pressure mercury lamp to cure the coating film.
Others are the same as in Example 3.

[Example 4]
(Creation of polarizing film)
A PVA film having an average degree of polymerization of 2700 and a thickness of 45 μm was stretched and conveyed while being dyed between rolls having different peripheral speed ratios. First, the PVA film was swelled by immersing it in a water bath at 30 ° C. for 1 minute, stretched 1.2 times in the transport direction, and then potassium iodide (0.03% by weight) and iodine (0.3% by weight). ) Was immersed in an aqueous solution (liquid temperature 30 ° C.) for 1 minute to stretch the film three times in the transport direction (based on unstretched film) while dyeing. Next, the stretched film is immersed in an aqueous solution (bath) of boric acid (4% by weight), potassium iodide (5% by weight) and zinc sulfate (3.5% by weight) for 30 seconds in the transport direction. Was stretched 6 times (based on unstretched film). After stretching, it was dried in an oven at 40 ° C. for 3 minutes to obtain a polarizing film having a thickness of 18.0 μm.
(Creation of polarizing film laminate)
A transparent protective film (manufactured by Nitto Denko KK) with a thickness of 30 μm made of a modified acrylic polymer having a lactone ring structure is bonded to one surface of the polarizing film in the same manner as in Example 3 via a dope-curable adhesive. I let you. On the other hand, the other surface of the polarizing film has the same configuration as the other surface of the third embodiment.
Others are the same as in Example 3.

[Example 5]
In producing the polarizing film laminate of Example 4, one of the above surfaces has the same configuration as that of Example 4, and the other surface contains a light absorber as a polarizing film protective film having a light absorbing ability. Acetylcellulose film (manufactured by Fujifilm, trade name "TJ40ULF", thickness 40 μm), triacetylcellulose film containing a light absorber placed on the visible side (manufactured by Konica Minolta, trade name "KC4UY", thickness 40 μm), A polarizing film protective film composed of a hard coat layer (manufactured by Nitto Denko Co., Ltd., thickness 9 μm) arranged on the visible side and having no light absorbing ability was used in the same manner as in Example 3, and the total thickness of the curable adhesive was 1.0 μm. It was joined via a dope-curable adhesive so that The triacetyl cellulose film (manufactured by Fujifilm, trade name "TJ40ULF", thickness 40 μm) and the triacetyl cellulose film (manufactured by Konica Minolta, trade name "KC4UY", thickness 40 μm) are used in the same manner as in Example 1. The curable adhesive was bonded via an ultraviolet curable adhesive so that the total thickness of the curable adhesive was 1.0 μm.
(Measurement of iodine concentration)
By using dichloromethane and methyl ethyl ketone as solvents, the polarizing film was taken out from the polarizing film laminate, and the iodine concentration of the polarizing film was measured.

(Measurement of transmittance)
From the polarizing film laminate, the polarizing film protective film located on the visual side of the polarizing film, that is, the polarizing film protective film composed of a triacetyl cellulose film, another triacetyl cellulose film, and a hard coat layer is peeled off. , The transmittance of the polarizing film protective film was measured.

[Comparative Example 6]
In producing the polarizing film laminate of Example 4, a transparent protective film (manufactured by Nitto Denko Co., Ltd.) having a thickness of 30 μm made of a modified acrylic polymer having a lactone ring structure was applied to one surface of the polarizing film in the same manner as in Example 3. By the method, they were joined via a dope-curable adhesive. On the other hand, a triacetyl cellulose film (manufactured by Fuji Film Co., Ltd., trade name "TJ40ULF", thickness 40 μm) containing a light absorber as a polarizing film protective film having a light absorbing ability on the other surface of the polarizing film absorbs light. A polarizing film protective film having a hard coat layer (manufactured by Nitto Denko Co., Ltd., thickness 9 μm) formed with no function is dope-cured by the same method as in Example 3 so that the total thickness of the curable adhesive is 1.0 μm. They were joined via an adhesive. In addition, the water content of the polarizing film laminate was changed.
Others are the same as in Example 4.

[Comparative Example 7]
In the preparation of 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. In addition, the water content of the polarizing film laminate was changed.
Others are the same as in Comparative Example 6.

[Comparative Example 8]
In the preparation of 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. In addition, the water content of the polarizing film laminate was changed.
Others are the same as in Example 4.

[Example 6]
In the preparation of 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. In addition, the water content of the polarizing film laminate was changed.
Others are the same as in Example 4.

[Example 7]
(Creation of polarizing film)
In the stretching treatment of the polarizing film of Example 3, a PVA film having a thickness of 75 μm was stretched and conveyed to obtain a polarizing film having a thickness of 28 μm. Further, in the dyeing treatment, the iodine concentration was changed by adjusting the concentration of the iodine aqueous solution and the immersion time.
(Creation of polarizing film laminate)
The other surface of one surface of the polarizing film has the same configuration as the one surface and the other surface of the polarizing film of Example 4, respectively. In addition, the water content of the polarizing film laminate was changed.
Others are the same as in Example 4.

[Example 8]
In producing the polarizing film laminate of Example 7, the water content of the polarizing film laminate was changed. Further, in Example 7, similarly to Example 4, when the film was stretched 6 times in the transport direction (based on the unstretched film), it was immersed in an aqueous solution (bath) of zinc sulfate (3.5% by weight). ..
Other conditions are the same as in Example 7.

[Comparative Example 9]
(Creation of polarizing film)
The polarizing film of Example 7 was used.
(Creation of polarizing film laminate)
One surface of the polarizing film has the same configuration as the one surface of the polarizing films of Examples 4 to 8 and Comparative Example 8. On the other hand, on the other surface of the polarizing film, a triacetyl cellulose film containing a light absorber as a polarizing film protective film having the same configuration as the other surface of the polarizing film of Comparative Example 5, that is, having a light absorbing ability, A polarizing film protective film composed of a hard coat layer having no light absorbing ability arranged on the visible side is doped and cured by the same method as in Example 3 so that the total thickness of the curing adhesive is 1.0 μm. They were joined via an agent. In addition, the water content of the polarizing film laminate was changed.
Other conditions are the same as in Example 7.

[Example 9]
In the preparation of the polarizing film of Example 4, the concentration of the iodine aqueous solution and the immersion time were adjusted in the dyeing treatment to change the iodine concentration.
Others are the same as in Example 4.

[Example 10]
In the preparation of the polarizing film of Example 3, the iodine concentration was changed by adjusting the concentration of the iodine aqueous solution and the immersion time in the dyeing treatment.
Further, in producing the polarizing film laminate of Example 3, as a transparent protective film made of a modified acrylic polymer having a lactone ring structure to be bonded to one surface of the polarizing film, instead of the transparent protective film having a thickness of 20 μm, A transparent protective film (manufactured by Nitto Denko Co., Ltd.) having a thickness of 30 μm was used. Furthermore, the water content of the polarizing film laminate was changed.
Others are the same as in Example 3.

[Comparative Example 10]
In the preparation of the polarizing film of Example 9, 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 9, a transparent protective film (manufactured by Nitto Denko Co., Ltd.) having a thickness of 30 μm made of a modified acrylic polymer having a lactone ring structure was applied to one surface of the polarizing film in the same manner as in Example 3. By the method, they were joined via a dope-curable adhesive. On the other hand, a triacetyl cellulose film (manufactured by Fuji Film Co., Ltd., trade name "TJ40ULF", thickness 40 μm) containing a light absorber as a polarizing film protective film having a light absorbing ability on the other surface of the polarizing film absorbs light. A polarizing film protective film having a hard coat layer (manufactured by Nitto Denko Co., Ltd., thickness 9 μm) formed with no function is dope-cured by the same method as in Example 3 so that the total thickness of the curable adhesive is 1.0 μm. They were joined via an adhesive. In addition, the water content of the polarizing film laminate was changed.
Others are the same as in Example 9.

[Example 11]
In the preparation of the polarizing film of Example 3, the iodine concentration was changed by adjusting the concentration of the iodine aqueous solution and the immersion time in the dyeing treatment.
Further, in producing the polarizing film laminate of Example 3, a dope-curable curable adhesive was used as an adhesive, and more specifically, a polyvinyl alcohol resin containing an acetoacetyl group (average degree of polymerization 1200, saponification degree 98). An aqueous solution containing .5 mol%, acetoacetylation degree 5 mol%) and methylol melamine in a weight ratio of 3: 1 was used. Using this adhesive, a transparent protective film having a thickness of 25 μm made of triacetyl cellulose was bonded to one surface of the polarizing film. Specifically, the dope-curable adhesive was coated so as to have a total thickness of 1.0 μm, and bonded using a roll machine. On the other hand, on the other surface of the polarizing film, as a polarizing film protective film having a light absorbing ability, the polarizing film protective film used in Example 1, that is, a triacetyl cellulose film containing a light absorber, and a visible side thereof. The polarizing film protective film composed of the hard coat layer containing the light absorber arranged in the above was bonded not with the ultraviolet curable adhesive but with the same dope curable curable adhesive in the same manner as one surface. .. Then, it is heated and dried in an oven at 70 ° C. for 5 minutes to have a polarizing film and a polarizing film protective film having no light absorbing ability on one surface of the polarizing film and having light absorbing ability on the other surface. A polarizing film laminate having a polarizing film protective film was obtained.

[Comparative Example 11]
In producing the polarizing film laminate of Example 11, as an adhesive, a dope-curable curable adhesive, more specifically, a polyvinyl alcohol resin containing an acetoacetyl group (average degree of polymerization 1200, saponification degree 98.5). An aqueous solution containing methylol melamine and methylol melamine at a weight ratio of 3: 1 was used. Using this adhesive, a transparent protective film having a thickness of 25 μm made of triacetyl cellulose was bonded to one surface of the polarizing film. Specifically, the dope-curable adhesive was coated so as to have a total thickness of 1.0 μm, and bonded using a roll machine. On the other hand, on the other surface of the polarizing film, as a polarizing film protective film having a light absorbing ability, the polarizing film protective film used in Comparative Example 5, that is, a triacetyl cellulose film containing a light absorber, and a visible side thereof. A polarizing film protective film composed of a hard coat layer containing no light absorber was bonded to one surface using the same dope-curable curable adhesive in the same manner as one surface, instead of the ultraviolet-curable adhesive. ..

[Comparative Example 12]
In the preparation of the polarizing film of Example 11, the concentration of the iodine aqueous solution and the immersion time were adjusted in the dyeing treatment to change the iodine concentration.
Others are the same as in Example 11.

[Comparative Example 13]
In the preparation of the polarizing film of Comparative Example 11, the concentration of the iodine aqueous solution and the immersion time were adjusted in the dyeing treatment to change the iodine concentration.
Others are the same as in Comparative Example 11.

4-1. Reliability Test Using the polarizing film laminates 12 obtained in Examples and Comparative Examples, as shown in FIG. 5, glass plates (Matsunami Glass) were placed on both sides of the polarizing film laminates 12 via

transparent adhesives

11 and 13, respectively. A sample was made by laminating a slide glass made of glass, product number: S2000423, specifications: water edge polishing 65 x 165 mm, thickness 1.3 mm).

As an adhesive, CS98210US (manufactured by Nitto Denko) with a thickness of 200 μm was used on one surface of the polarizing film laminate, and used for the polarizing film laminate (manufactured by Nitto Denko) of CRT1794YCU on the other surface of the polarizing film laminate. An acrylic adhesive (thickness 20 μm) was used. The acrylic pressure-sensitive adhesive used on the other side was prepared by placing 99 parts by weight of butyl acrylate (the same applies hereinafter) and 4-hydroxybutyl acrylate in a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer and a stirrer. 0 part and 0.3 part of 2,2'-azobisisobutyronitrile were added together with ethyl acetate and reacted at 60 ° for 4 hours under a nitrogen gas stream, and then ethyl acetate was added to the reaction solution. A solution containing an acrylic polymer having a weight average molecular weight of 1.65 million (solid content concentration: 30% by weight) was obtained, and 0.3 part of dibenzoyl peroxide (manufactured by Nippon Oil & Fat Co., Ltd.) per 100 parts of the solid content of this acrylic polymer solution was obtained. ): Niper BMT), 0.1 part of trimetyl propanthylene diisocyanate (Mitsui Takeda Chemical Co., Ltd .: Takenate D110N), and 0.2 part of silane coupling agent (manufactured by Ryokuken Kagaku Co., Ltd .: A-). It was obtained by blending 100, an acetoacetyl group-containing silane coupling agent).

A xenon light irradiation test was performed on each sample using a xenon weather meter (manufactured by Suga Test Instruments Co., Ltd .: NX75).
(Xenon light irradiation test)
Black panel temperature 89 ° C., 30% R. H. In this atmosphere, the sample is irradiated with xenon light for 200 hours at an ^{irradiance of 100 W / m 2 integrated in a wavelength range of 300 to 400 nm.} The light source used was a xenon lamp (manufactured by Suga Test Instruments Co., Ltd.) with a daylight filter (manufactured by Suga Test Instruments Co., Ltd.) attached. After 200 hours of irradiation, color loss and heat redness were evaluated, and after 200 hours of irradiation, polyene formation was also evaluated.

4-2. Evaluation Criteria The evaluation criteria for polyene formation, heating redness, and color loss are shown below.

<Polyene>
The single transmittance of the sample was measured before and after the xenon light irradiation test, and the amount of change ΔTs in the single transmittance was calculated by the following formula.
(Equation) ΔTs = Ts xenon 200-Ts ₀
Here, Ts ₀ is the simple substance transmittance of the sample before xenon irradiation, and Ts xenon 200 is the simple substance transmittance after the xenon light irradiation test.
When the single transmittance after irradiation with xenon light for 200 hours was −0.5 or more as compared with the single transmittance before irradiation with xenon light, it was evaluated that the problem of polyene formation was within an acceptable range and there was no problem. When the single transmittance after irradiation with xenon light for 200 hours was −0.2 or more as compared with the single transmittance before irradiation with xenon light, it was evaluated that the problem of polyene formation was not a problem. Furthermore, when the single transmittance after irradiation with xenon light for 200 hours is the same as or larger than the single transmittance before irradiation with xenon light, it was evaluated that the problem of polyene formation is not a problem.
The single transmittance was measured for the above sample using a spectrophotometer (product name "DOT-3" manufactured by Murakami Color Technology Research Institute Co., Ltd.). The simple substance transmittance can be obtained according to JlS Z 8701.

<Color loss / heating red discoloration>
Before and after the xenon light irradiation test, the sample was placed on the cross Nicol and the orthogonal transmittances (%) at wavelengths of 410 nm and 700 nm were measured by the spectrophotometer, respectively, and the respective changes, ΔHs ₄₁₀ and ΔHs _700, were determined. ..
Those satisfying all of the following two conditions were evaluated as "color loss" of the sample.
-Change amount ΔHs ₄₁₀ is 1% or more-Change amount ΔHs ₇₀₀ is 5% or more In other words, the change amount of the orthogonal transmittance at a wavelength of 410 nm after irradiation with xenone light for 200 hours is less than 1% and the wavelength is 700 nm. When the amount of change in the orthogonal transmittance in was less than 5%, it was evaluated that there was no problem of color loss.
In addition, those satisfying the following conditions were evaluated as "heated redness" of the sample.
-Change amount ΔHs ₄₁₀ is less than 1% -Change amount ΔHs ₇₀₀ is 5% or more In other words, the amount of change in orthogonal transmittance at a wavelength of 410 nm after irradiation with xenone light for 200 hours is 1% or more and a wavelength of 700 nm. When the amount of change in the orthogonal transmittance in was less than 5%, it was evaluated that the problem of heating redness did not exist.

The evaluation results in each example and comparative example are shown in Tables 2 and 3 below.

5. Summary of Evaluation Results FIG. 6 is a plot of the results of Examples and Comparative Examples centered on the Examples in the xy orthogonal coordinate system. Furthermore, when the results of the Examples and the Comparative Examples overlap, " The results of "Examples" are shown, and conversely, FIG. 7 is a plot of the results of Examples and Comparative Examples centered on Comparative Examples, and more specifically, the results of Examples and Comparative Examples. When are duplicated, the result of "comparative example" is shown. The x-axis (horizontal axis) indicates the iodine concentration (wt.%) Of the polarizing film, and the y-axis (vertical axis) indicates the water content (g / m ² ) of the polarizing film laminate.

(1) From the results of plotting and common general knowledge, in general, when the iodine concentration is low and the water content is too small, the problem of heating redness that occurs in a high temperature state is likely to occur, while the iodine concentration is high and the water content is high. If is too large, it can be said that problems of polyenization and color loss are likely to occur. Further, when the iodine concentration is low and the water content is too large, the problem of color loss that occurs in a high temperature and high humidity state is likely to occur, and in this case, the problem of polyene formation is likely to occur as the iodine concentration increases. it can. In particular, a transition region (Comparative Example 1) between them was also found between the color loss and the polyene formation. Although the result of heating redness is not particularly shown in FIG. 6, it can be said that it is clear from common general knowledge that this phenomenon occurs when the iodine concentration is low and the water content is too small.
On the other hand, when both the iodine concentration and the water content are neither too large nor too small and the two are in a balanced state, therefore, the iodine concentration and the water content can be such a balance. If it fits within the area of, it can be seen that heating redness, polyene formation, and color loss can all be comprehensively resolved. For example, all the results of the examples have a small amount of water but a large iodine concentration around the plot showing the results of Example 2, that is, the iodine concentration of 6.0 wt. % And a coordinate point of 0.7 g / m ² (hereinafter referred to as the first coordinate point) and the periphery of the plot showing the result of Example 7 in which the iodine concentration is (most) small but the water content is large, that is, the iodine concentration. 1.8 wt. % And the partition line "α" passing through the coordinate point of 4.2 g / m ² (hereinafter referred to as the second coordinate point), that is, above y = (239.4-35x) / 42 and Around the plot showing the results of Example 6, where the water content is (most) high but the iodine concentration is (lowest), that is, the iodine concentration is 1.8 wt. % And a coordinate point of 5.1 g / m ² (hereinafter referred to as the third coordinate point) and the periphery of the plot showing the results of Example 1 in which the iodine concentration is (most) high but the water content is (lowest). , Iodine concentration 7.0 wt. % And the partition line "β" passing through the coordinate point of 0.7 g / m ² (hereinafter referred to as the fifth coordinate point), that is, located below y = (344.4-44x) / 52. There is. Therefore, at least, the region partitioned by these partition lines "α" and "β" should be regarded as a line showing the requirements necessary to comprehensively solve all of heating redness, polyene formation, and color loss. Can be done. Further, considering the result of the comparative example, the coordinate point that can be connected to each of the third coordinate point and the fifth coordinate point without including the comparative example, that is, the iodine concentration is 5.7 wt. A coordinate point of% and a water content of 2.6 g / m ² (hereinafter referred to as a fourth coordinate point) can also be considered. That is, all the results of the examples are below the partition line "γ1" passing between the third coordinate point and the fourth coordinate point, that is, y = (243.9-25x) / 39, and the first It is positioned below the partition line "γ2" that passes between the 4th coordinate point and the 5th coordinate point, that is, y = (142.1-19x) / 13. In addition, these partition lines "α", "β", "γ1", and "γ2" are all polarizing films having a film thickness of about 4 to 30 μm, regardless of the film thickness of the polarizing film. It is to be applied with respect to.

(2) From these facts, in particular, for all the polarizing films having a film thickness of about 4 to 30 μm, the iodine concentration and the water content of the polarizing film laminate are, for example, the region surrounded by a to e, and further details. The iodine concentration is 6.0 wt. % And the first coordinate point (“a” in the figure) having a water content of 0.7 g / m ^{2 and an iodine concentration of 1.8 wt.} The first line segment connecting the second coordinate point (“b” in the figure) of% and the water content of 4.2 g / m ^{2, the second coordinate point “b”, and the iodine concentration of 1.8 wt.} The second line segment connecting the third coordinate point (“c” in the figure) of% and the water content of 5.1 g / m ^{2, the third coordinate point “c”, and the iodine concentration of 5.7 wt.} The third line segment connecting the fourth coordinate point (“d” in the figure) of% and the water content of 2.6 g / m ^{2, the fourth coordinate point “d”, and the iodine concentration of 7.0 wt.} % And the fourth line segment connecting the fifth coordinate point (“e” in the figure) of 0.7 g / m ^{2 and the first coordinate point “a” and the fifth coordinate point “e”.} When it is included in the region surrounded by the fifth line segment to be connected, it can be seen that all of "polyenization", "color loss", and "heating red discoloration" can be comprehensively solved.

(3) Similarly, particularly for a polarizing film having a film thickness of about 11 to 30 μm, the iodine concentration and the water content of the polarizing film laminate are surrounded by f, b, c, and g, and more specifically. , Iodine concentration 4.5 wt. The sixth line segment connecting the sixth coordinate point (“f” in the figure) and the second coordinate point “b” with% and water content of 1.9 g / m ^{2, the second coordinate point “b” and the third.} The second line segment connecting the coordinate point "c", the third coordinate point "c" and the iodine concentration 4.5 wt. % And the 7th line segment connecting the 7th coordinate point (“g” in the figure) of 3.4 g / m ^{2 and the 6th coordinate point “f” and the 7th coordinate point “g”.} It can be seen that all of "polyenization", "color loss", and "heating red discoloration" can be comprehensively solved when they are included in the region surrounded by the eighth line segment connecting them.
In particular, the sixth coordinate point "f" has an iodine concentration of 4.0 wt. % And the water content is 2.4 g / m ² , which is the 8th coordinate point (“f-1” in the figure), and the 7th coordinate point “g” is the iodine concentration of 4.0 wt. It is considered that a preferable result can be obtained when it is the ninth coordinate point (“g-1” in the figure) of% and the water content of 3.7 g / m ^2. The sixth coordinate point "f" has an iodine concentration of 3.7 wt. % And the water content is 2.6 g / m ² , which is the 10th coordinate point (“h” in the figure), and the 7th coordinate point “g” is also the 4th coordinate point “d”, which is a preferable result. Is considered to be obtained.

(4) Further, particularly for a polarizing film having a film thickness of about 4 to 11 μm, a region in which the iodine concentration and the water content of the polarizing film laminate are surrounded by a, h, d, and e, more specifically, A ninth line segment connecting the first coordinate point "a" and the tenth coordinate point "h", an eleventh line segment connecting the tenth coordinate point "h" and the fourth coordinate point "d", and a first line segment. When it is included in the area surrounded by the fifth line segment connecting the 1st coordinate point "a" and the 5th coordinate point "e", "polyenization", "color loss", and "heating reddening" It turns out that everything can be solved comprehensively.

Further, as is clear from the comparison between FIGS. 6 and 7, it can be seen that the polyene formation is effectively prevented by providing the light absorption layer having a light absorption ability.

In the above embodiment, an example in which a light absorber was added to the polarizing film protective film was shown. However, the same result can be obtained even when the transparent adhesive (OCA) 13 (transparent adhesive layer) contains a light absorber (ultraviolet absorber) and the above reliability test is performed. Further, the same result can be obtained even when the cover plate 14 (transparent cover plate) contains a light absorber (ultraviolet absorber) and the above reliability test is performed. In that case, use the cover plate 14 instead of the glass plate (Matsunami glass slide glass, product number: S2000423, specifications: water edge polishing 65 x 165 mm, thickness 1.3 mm) on the visible side of the transparent adhesive 13. Perform a reliability test.

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 Polarizing film protective film with light absorption capacity 122 Polarizing film protective film

Claims

A polarizing film laminate comprising a polarizing film made of a polyvinyl alcohol-based resin and an optically transparent polarizing film protective film bonded directly to at least the viewing side surface of the polarizing film or via another optical film. hand,
In an xy Cartesian coordinate system in which the iodine concentration (wt.%) Of the polarizing film is on the x-axis and the water content (g / m2) of the polarizing film laminate is on the y-axis.
Iodine concentration 6.0 wt. % And the first coordinate point with a water content of 0.7 g / m2 and an iodine concentration of 1.8 wt. % And the first line segment connecting the second coordinate point with a water content of 4.2 g / m2,
The second coordinate point and the iodine concentration of 1.8 wt. % And a second line segment connecting the third coordinate point with a water content of 5.1 g / m2,
The third coordinate point and the iodine concentration of 5.7 wt. % And a third line segment connecting the fourth coordinate point with a water content of 2.6 g / m2,
The fourth coordinate point and the iodine concentration of 7.0 wt. Included in the area surrounded by the fourth line segment connecting the fifth coordinate point of% and the water content of 0.7 g / m2 and the fifth line segment connecting the first coordinate point and the fifth coordinate point. Has an iodine concentration and water content
The polarizing film protective film is a light absorbing layer having a light absorbing ability, and is a polarizing film laminate characterized by having a light transmittance of 5% or less at a wavelength of 380 nm.
The polarizing film laminate according to claim 1, wherein the polarizing film has a film thickness of 4 to 30 μm.
A polarizing film laminate comprising a polarizing film made of a polyvinyl alcohol-based resin and an optically transparent polarizing film protective film bonded directly to at least the viewing side surface of the polarizing film or via another optical film. hand,
In an xy Cartesian coordinate system in which the iodine concentration (wt.%) Of the polarizing film is on the x-axis and the water content (g / m2) of the polarizing film laminate is on the y-axis.
Iodine concentration 4.5 wt. % And the sixth coordinate point of 1.9 g / m2 of water content and the iodine concentration of 1.8 wt. % And a sixth line segment connecting the second coordinate point with a water content of 4.2 g / m2,
The second coordinate point and the iodine concentration of 1.8 wt. % And a second line segment connecting the third coordinate point with a water content of 5.1 g / m2,
The third coordinate point and the iodine concentration of 4.5 wt. Included in the area surrounded by the 7th line segment connecting the 7th coordinate point of% and the water content of 3.4 g / m2 and the 8th line segment connecting the 6th coordinate point and the 7th coordinate point. Has an iodine concentration and water content
The polarizing film protective film is a light absorbing layer having a light absorbing ability, and is a polarizing film laminate characterized by having a light transmittance of 5% or less at a wavelength of 380 nm.
The sixth coordinate point has an iodine concentration of 4.0 wt. % And the water content is 2.4 g / m2, which is the eighth coordinate point, and the seventh coordinate point is the iodine concentration of 4.0 wt. The polarizing film laminate according to claim 3, which is a ninth coordinate point having a% and a water content of 3.7 g / m2.
The sixth coordinate point has an iodine concentration of 3.7 wt. The polarizing film laminate according to claim 3, wherein the 10th coordinate point has a% and a water content of 2.6 g / m2, and the 7th coordinate point is the 4th coordinate point.
The polarizing film laminate according to claim 3 or 4, wherein the polarizing film has a film thickness of 11 to 30 μm.
A polarizing film laminate comprising a polarizing film made of a polyvinyl alcohol-based resin and an optically transparent polarizing film protective film bonded directly to at least the viewing side surface of the polarizing film or via another optical film. hand,
In an xy Cartesian coordinate system in which the iodine concentration (wt.%) Of the polarizing film is on the x-axis and the water content (g / m2) of the polarizing film laminate is on the y-axis.
Iodine concentration 6.0 wt. % And the first coordinate point with a water content of 0.7 g / m2 and an iodine concentration of 3.7 wt. % And the ninth line segment connecting the tenth coordinate point with a water content of 2.6 g / m2,
The tenth coordinate point and the iodine concentration of 5.7 wt. % And the tenth line segment connecting the fourth coordinate point with a water content of 2.6 g / m2,
The fourth coordinate point and the iodine concentration of 7.0 wt. % And the eleventh line segment connecting the fifth coordinate point with a water content of 0.7 g / m2,
as well as
It has an iodine concentration and a water content contained in a region surrounded by a fifth line segment connecting the first coordinate point and the fifth coordinate point.
The polarizing film protective film is a light absorbing layer having a light absorbing ability, and is a polarizing film laminate characterized by having a light transmittance of 5% or less at a wavelength of 380 nm.
The polarizing film laminate according to claim 7, wherein the polarizing film has a film thickness of 4 to 11 μm.
The polarizing film laminate according to any one of claims 1 to 8, wherein the polarizing film protective film has a light transmittance of 35% or less at a wavelength of 390 nm.
)
The polarizing film laminate according to any one of claims 1 to 9, wherein the polarizing film protective film has a light transmittance of 70% or less at a wavelength of 400 nm.
The polarizing film laminate according to any one of claims 1 to 10, wherein the polarizing film contains zinc.
A sample composed of the polarizing film laminate according to any one of claims 1 to 11 and a glass plate laminated on both sides of the polarizing film laminate with an adhesive, a black panel temperature of 89 ° C. and 30%. R. H. The single transmittance after irradiating xenone light in the wavelength range of 300 to 400 nm for 200 hours with an irradiance of 100 W / m2 is -0.5 or more as compared with the single transmittance before irradiation. The polarizing film laminate according to any one of claims 1 to 11.
A black panel temperature of 89 ° C., 30% in a sample comprising the polarizing film laminate according to any one of claims 1 to 12 and a glass plate laminated on both sides of the polarizing film laminate with an adhesive. R. H. After irradiating xenon light in the wavelength range of 300 to 400 nm for 200 hours with an irradiance of 100 W / m2, the amount of change in the orthogonal transmittance at a wavelength of 410 nm is less than 1% and at a wavelength of 700 nm. The polarizing film laminate according to any one of claims 1 to 12, wherein the amount of change in the orthogonal transmittance is less than 5%.
A sample comprising the polarizing film laminate according to any one of claims 1 to 13 and a glass plate laminated on both sides of the polarizing film laminate via an adhesive, at a black panel temperature of 89 ° C. and 30%. R. H. After irradiating xenon light in the wavelength range of 300 to 400 nm for 200 hours with an irradiance of 100 W / m2, the amount of change in the orthogonal transmittance at a wavelength of 410 nm is 1% or more, and the wavelength is 700 nm. The polarizing film laminate according to any one of claims 1 to 13, wherein the amount of change in the orthogonal transmittance is less than 5%.
Optical display cell and
The polarizing film laminate according to any one of claims 1 to 14, which is bonded directly to one surface of the optical display cell or via another optical film.
An optically transparent cover plate arranged along the polarizing film laminate on the side opposite to the optical display cell,
With
The optical display cell, the polarizing film laminate, and the transparent cover plate are adhered to each other by a transparent adhesive layer that fills the space between them without any voids.
An optical display panel that features this.
The optical display panel according to claim 15, wherein the transparent cover plate has a function of a capacitive touch sensor.
The optical display panel according to claim 16, wherein an ITO layer as a component of a capacitive touch sensor is provided between the transparent cover plate and the polarizing film laminate.
A polarizing film laminate provided with a polarizing film made of a polyvinyl alcohol-based resin and an optically transparent polarizing film protective film bonded directly to at least the viewing side surface of the polarizing film or via another optical film.
A transparent adhesive layer laminated on the visual side of the polarizing film laminate is provided.
In an xy Cartesian coordinate system in which the iodine concentration (wt.%) Of the polarizing film is on the x-axis and the water content (g / m2) of the polarizing film laminate is on the y-axis.
Iodine concentration 6.0 wt. % And the first coordinate point with a water content of 0.7 g / m2 and an iodine concentration of 1.8 wt. % And the first line segment connecting the second coordinate point with a water content of 4.2 g / m2,
The second coordinate point and the iodine concentration of 1.8 wt. % And a second line segment connecting the third coordinate point with a water content of 5.1 g / m2,
The third coordinate point and the iodine concentration of 5.7 wt. % And a third line segment connecting the fourth coordinate point with a water content of 2.6 g / m2,
The fourth coordinate point and the iodine concentration of 7.0 wt. Included in the area surrounded by the fourth line segment connecting the fifth coordinate point of% and the water content of 0.7 g / m2 and the fifth line segment connecting the first coordinate point and the fifth coordinate point. Has an iodine concentration and water content
Of 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 the light transmittance of the transparent adhesive layer and the laminate of the polarizing film protective film at a wavelength of 380 nm is 5% or less.
A polarizing film laminate comprising a polarizing film made of a polyvinyl alcohol-based resin and an optically transparent polarizing film protective film bonded directly to the surface of the polarizing film on the side opposite to the visible side or via another optical film. When,
A transparent adhesive layer laminated on the visual side of the polarizing film laminate is provided.
In an xy Cartesian coordinate system in which the iodine concentration (wt.%) Of the polarizing film is on the x-axis and the water content (g / m2) of the polarizing film laminate is on the y-axis.
Iodine concentration 6.0 wt. % And the first coordinate point with a water content of 0.7 g / m2 and an iodine concentration of 1.8 wt. % And the first line segment connecting the second coordinate point with a water content of 4.2 g / m2,
The second coordinate point and the iodine concentration of 1.8 wt. % And a second line segment connecting the third coordinate point with a water content of 5.1 g / m2,
The third coordinate point and the iodine concentration of 5.7 wt. % And a third line segment connecting the fourth coordinate point with a water content of 2.6 g / m2,
The fourth coordinate point and the iodine concentration of 7.0 wt. Included in the area surrounded by the fourth line segment connecting the fifth coordinate point of% and the water content of 0.7 g / m2 and the fifth line segment connecting the first coordinate point and the fifth coordinate point. Has an iodine concentration and water content
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 the light transmittance of the transparent adhesive layer at a wavelength of 380 nm is 5% or less.
A polarizing film laminate provided with a polarizing film made of a polyvinyl alcohol-based resin and an optically transparent polarizing film protective film bonded directly to at least the viewing side surface of the polarizing film or via another optical film.
A transparent adhesive layer laminated on the visual side of the polarizing film laminate,
An optically transparent cover plate laminated on the visual side of the transparent adhesive layer is provided.
In an xy Cartesian coordinate system in which the iodine concentration (wt.%) Of the polarizing film is on the x-axis and the water content (g / m2) of the polarizing film laminate is on the y-axis.
Iodine concentration 6.0 wt. % And the first coordinate point with a water content of 0.7 g / m2 and an iodine concentration of 1.8 wt. % And the first line segment connecting the second coordinate point with a water content of 4.2 g / m2,
The second coordinate point and the iodine concentration of 1.8 wt. % And a second line segment connecting the third coordinate point with a water content of 5.1 g / m2,
The third coordinate point and the iodine concentration of 5.7 wt. % And a third line segment connecting the fourth coordinate point with a water content of 2.6 g / m2,
The fourth coordinate point and the iodine concentration of 7.0 wt. Included in the area surrounded by the fourth line segment connecting the fifth coordinate point of% and the water content of 0.7 g / m2 and the fifth line segment connecting the first coordinate point and the fifth coordinate point. Has an iodine concentration and water content
Of the polarizing film protective 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 the light transmittance of the polarizing film protective film, the transparent adhesive layer, and the laminated body of the transparent cover plate at a wavelength of 380 nm is 5% or less.
A polarizing film laminate comprising a polarizing film made of a polyvinyl alcohol-based resin and an optically transparent polarizing film protective film bonded directly to the surface of the polarizing film on the side opposite to the visible side or via another optical film. When,
A transparent adhesive layer laminated on the visual side of the polarizing film laminate,
An optically transparent cover plate laminated on the visual side of the transparent adhesive layer is provided.
In an xy Cartesian coordinate system in which the iodine concentration (wt.%) Of the polarizing film is on the x-axis and the water content (g / m2) of the polarizing film laminate is on the y-axis.
Iodine concentration 6.0 wt. % And the first coordinate point with a water content of 0.7 g / m2 and an iodine concentration of 1.8 wt. % And the first line segment connecting the second coordinate point with a water content of 4.2 g / m2,
The second coordinate point and the iodine concentration of 1.8 wt. % And a second line segment connecting the third coordinate point with a water content of 5.1 g / m2,
The third coordinate point and the iodine concentration of 5.7 wt. % And a third line segment connecting the fourth coordinate point with a water content of 2.6 g / m2,
The fourth coordinate point and the iodine concentration of 7.0 wt. Included in the area surrounded by the fourth line segment connecting the fifth coordinate point of% and the water content of 0.7 g / m2 and the fifth line segment connecting the first coordinate point and the fifth coordinate point. Has an iodine concentration and water content
Of 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 the light transmittance of the transparent adhesive layer and the laminated body of the transparent cover plate at a wavelength of 380 nm is 5% or less.