WO2021039585A1

WO2021039585A1 - Polarization film laminate provided with adhesive layer, and optical display panel in which polarization film laminate provided with adhesive layer is used

Info

Publication number: WO2021039585A1
Application number: PCT/JP2020/031457
Authority: WO
Inventors: 智之木村; 寛大小野; 雄祐外山; 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: 2020-08-20
Publication date: 2021-03-04
Also published as: TW202116950A; CN114302936B; CN114302936A; JP7309522B2; JP2021033164A; KR20220050912A

Abstract

Provided is a polarization film laminate, etc., with which it is possible to comprehensively solve the problems of polyenization, decoloration, and heating reddening.　A polarization film laminate comprising a polarization film that includes a polyvinyl-alcohol-based resin, and an adhesive layer provided directly to at least one surface of the polarization film or provided to the at least one surface with an optically transparent polarization-film-protecting film interposed therebetween, the adhesive layer including an adhesive polymer and an ionic compound, the adhesive polymer including 0.1-30 wt.% of polar-group-containing monomers as monomer units among all monomer components constituting the adhesive polymer, and the polarization film laminate having an iodine concentration and a moisture content such that, in an x-y orthogonal coordinate system in which the iodine concentration of the polarization film is represented on the x-axis and the moisture content of the polarization film laminate is represented on the y-axis, the iodine concentration and the moisture content are included within a region bounded by: a first line segment connecting a first coordinate point at an iodine concentration of 7.0 wt.% and a moisture content of 0.7 g/m², and a second coordinate point at an iodine concentration of 2.2 wt.% and a moisture content of 3.2 g/m²; a second line segment connecting the second coordinate point and a third coordinate point at an iodine concentration of 2.2 wt.% and a moisture content of 4.0 g/m²; a third line segment connecting the third coordinate point and a fourth coordinate point at an iodine concentration of 3.0 wt.% and a moisture content of 4.0 g/m²; a fourth line segment connecting the fourth coordinate point and a fifth coordinate point at an iodine concentration of 10.0 wt.% and a moisture content of 0.7 g/m²; and a fifth line segment connecting the first coordinate point and the fifth coordinate point.

Description

A polarizing film laminate with an adhesive layer and an optical display panel in which the polarizing film laminate with an adhesive layer is used.

The present invention relates to a polarizing film laminate with an adhesive layer and an optical display panel in which the polarizing film laminate with an adhesive layer is used.

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.

However, unlike smartphones and the like, powered vehicles are often used in harsh outdoor environments, and are used for optical display panels, especially optical display panels, depending on the usage environment such as high temperature or high humidity. The performance of the polarizing film laminate (polarizing plate) and the polarizing film (polarizer) used in the polarizing film laminate 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.

In addition, a liquid crystal display device equipped with a touch panel on the display screen has been put into practical use. As the touch panel, there are various types such as a capacitance type, a resistance film type, an optical type, an ultrasonic type, and an electromagnetic induction type, but the capacitance type is widely adopted. In recent years, a liquid crystal display device with a touch sensing function, which has a built-in capacitance sensor as a touch sensor unit, is often used.

When the polarizing film with an adhesive layer is attached to a liquid crystal cell during the manufacture of a liquid crystal display device, the release film is peeled from the adhesive layer of the polarizing film with an adhesive layer, but the release of the release film causes static electricity. Occurs. In addition, static electricity is also generated when the surface protective film of the polarizing film attached to the liquid crystal cell is peeled off or when the surface protective film of the cover window is peeled off. The static electricity generated in this way affects the orientation of the liquid crystal layer inside the liquid crystal display device and causes defects. The generation of static electricity can be suppressed, for example, by forming an antistatic layer on the outer surface of the polarizing film.

On the other hand, the capacitance sensor in the liquid crystal display device with a touch sensing function detects the weak capacitance formed by the transparent electrode pattern and the finger when the user's finger approaches the surface thereof. When a conductive layer such as an antistatic layer is provided between the transparent electrode pattern and the user's finger, the electric field between the drive electrode and the sensor electrode is disturbed, and the sensor electrode capacitance becomes unstable. The sensitivity of the touch panel decreases, which causes malfunction. A liquid crystal display device with a touch sensing function is required to suppress the generation of static electricity and the malfunction of the capacitance sensor. In Patent Document 4, in order to reduce the occurrence of display defects and malfunctions in the liquid crystal display device with a touch sensing function, the surface resistance value is 1.0 × 10 ⁹ to 1.0 × 10 ¹¹ Ω. It has been proposed to place a polarizing film having an antistatic layer of / □ on the visible side of the liquid crystal layer.

Japanese Unexamined Patent Publication No. 2003-29042 Japanese Unexamined Patent Publication No. 2014-102353 JP-A-2002-90546 Japanese Unexamined Patent Publication No. 2013-105154

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. This is a phenomenon in which the orthogonal transmittance increases when the polarizing film laminates are arranged in a cross Nicol 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. "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. ..
An object of the present invention is to comprehensively solve these three problems by adjusting the iodine concentration of the polarizing film and the water content of the polarizing film laminate.

Further, according to the polarizing film having the antistatic layer described in Patent Document 4, it is possible to suppress the generation of static electricity to some extent. However, in Patent Document 4, since the location where the antistatic layer is arranged is far from the fundamental position where static electricity is generated, it is not effective as compared with the case where the adhesive layer is provided with the antistatic function.

The pressure-sensitive adhesive layer containing an ionic compound is more effective than the antistatic layer provided on the polarizing film in suppressing the generation of static electricity and preventing uneven static electricity. However, it was found that the antistatic function of the pressure-sensitive adhesive layer containing the ionic compound deteriorates over time. In particular, in a humidified environment (after the humidification reliability test), the ionic compound in the pressure-sensitive adhesive layer segregates at the interface with the optical film (polarizing film) or migrates into the optical film (polarizing film). It was found that the surface resistance value of the pressure-sensitive adhesive layer was increased and the antistatic function was significantly reduced. It has been found that such a decrease in the antistatic function of the adhesive layer causes the occurrence of static electricity unevenness and malfunction of the liquid crystal display device with the touch sensing function.

In order to suppress the deterioration of the antistatic function over time, it is effective to introduce a polar group into the polymer forming the pressure-sensitive adhesive layer, but the present inventors have introduced the polar group into the pressure-sensitive adhesive polymer. It was found that this raises a new issue of worsening polyene formation. In the above-mentioned prior art, although the polyene formation of the polarizing film has been studied, the compatibility with the antistatic function of the pressure-sensitive adhesive layer has not been studied, and the problem is not disclosed at all.

The present inventors have focused on the effect of the polar group of the pressure-sensitive adhesive polymer on the performance of the polarizing film, and have completed the present invention. In the prior art, from the viewpoint of the relationship between the ratio of polar group-containing monomers in the monomer components constituting the pressure-sensitive adhesive polymer and the performance of the polarizing film laminate with the pressure-sensitive adhesive layer such as reliability of optical properties and antistatic function. Nothing was done to consider. The present inventors have found the amount of polar group-containing monomers in all the monomer components of the pressure-sensitive adhesive polymer, which is required to obtain a polarizing film laminate with a pressure-sensitive adhesive layer having excellent properties.

In order to solve the above problems, the polarizing film film laminate according to one aspect of the present invention protects a polarizing film containing a polyvinyl alcohol-based resin and a polarizing film that is directly or optically transparent on at least one surface of the polarizing film. A polarizing film laminate with an adhesive layer, comprising an adhesive layer provided via a film.
The pressure-sensitive adhesive layer contains a pressure-sensitive adhesive polymer and an ionic compound, and the pressure-sensitive adhesive polymer contains 0.1 to 30% by weight of a polar group-containing monomer as a monomer unit in all the monomer components constituting the pressure-sensitive adhesive polymer. There,
Iodine concentration 7 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 / m ^{2) of the polarizing film laminate is on the y-axis.} .0 wt. % And the first coordinate point with a water content of 0.7 g / m ² and an iodine concentration of 2.2 wt. % And a first line segment connecting a second coordinate point having a water content of 3.2 g / m ² , the second coordinate point and an iodine concentration of 2.2 wt. % And a second line segment connecting a third coordinate point having a water content of 4.0 g / m ² , the third coordinate point and an iodine concentration of 3.0 wt. % And a third line segment connecting the fourth coordinate point having a water content of 4.0 g / m ² , the fourth coordinate point and the iodine concentration 10.0 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. It is characterized by having the concentration of iodine contained and the amount of water.
The polarizing film film laminate with an adhesive layer of this embodiment comprehensively solves the problems of "polyene formation", "color loss", "heat redness", and "deterioration of antistatic function over time". can do.

In the polarizing film film laminate of the above aspect, the polar group-containing monomer may be an amide group-containing monomer and / or an alkoxyalkyl group-containing monomer. This also applies to (further) another aspect of the present invention.

In the polarizing film film laminate of the above aspect, the ionic compound may be an alkali metal salt and / or an organic cation-anion salt. This also applies to (further) another aspect of the present invention.

In the polarizing film film laminate of the above aspect, the pressure-sensitive adhesive layer may be provided on the polarizing film or the polarizing film protective film via a conductive layer. This also applies to (further) another aspect of the present invention.

In the polarizing film film laminate of the above aspect, the film thickness of the polarizing film may be 4 to 20 μm.

Further, in the polarizing film film laminate according to another aspect of the present invention, a polarizing film containing a polyvinyl alcohol-based resin and a polarizing film protective film which is directly or optically transparent is provided on at least one surface of the polarizing film. A polarizing film laminate with a pressure-sensitive adhesive layer, which comprises the pressure-sensitive adhesive layer.
The pressure-sensitive adhesive layer contains a pressure-sensitive adhesive polymer and an ionic compound, and the pressure-sensitive adhesive polymer contains 0.1 to 30% by weight of a polar group-containing monomer as a monomer unit in all the monomer components constituting the pressure-sensitive adhesive polymer. There,
Iodine concentration 4 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 / m ^{2) of the polarizing film laminate is on the y-axis.} .5 wt. The sixth coordinate point of% and water content of 2.0 g / m ² and the iodine concentration of 2.2 wt. % And a sixth line segment connecting the second coordinate point having a water content of 3.2 g / m ² , the second coordinate point and the iodine concentration of 2.2 wt. % And a second line segment connecting a third coordinate point having a water content of 4.0 g / m ² , the third coordinate point and an iodine concentration of 3.0 wt. % And a third line segment connecting the fourth coordinate point having a water content of 4.0 g / m ² , the fourth 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 3.3 g / m ² and the 8th line segment connecting the 6th coordinate point and the 7th coordinate point. It is characterized by having the concentration of iodine contained and the amount of water.

In the polarizing film film laminate of the above aspect, the sixth coordinate point has an iodine concentration of 4.0 wt. % And a coordinate point having a water content of 2.3 g / m ² , and the seventh coordinate point has an iodine concentration of 4.0 wt. It may be a coordinate point of% and a water content of 3.5 g / m ^2.

In the polarizing film film laminate of the above aspect, the film thickness of the polarizing film may be 11 to 20 μm.

The polarizing film film laminate according to still another aspect of the present invention is provided on at least one surface of the polarizing film containing a polyvinyl alcohol-based resin via a polarizing film protective film which is directly or optically transparent. A polarizing film laminate with an adhesive layer, which comprises an adhesive layer.
The pressure-sensitive adhesive layer contains a pressure-sensitive adhesive polymer and an ionic compound, and the pressure-sensitive adhesive polymer contains 0.1 to 30% by weight of a polar group-containing monomer as a monomer unit in all the monomer components constituting the pressure-sensitive adhesive polymer. There,
Iodine concentration 7 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 / m ^{2) of the polarizing film laminate is on the y-axis.} .0 wt. % And the first coordinate point with a water content of 0.7 g / m ^{2 and an iodine concentration of 3.0 wt.} The eleventh line segment connecting the eighth coordinate point of% and the water content of 2.6 g / m ² , the eighth coordinate point, and the iodine concentration of 6.0 wt. % And the tenth line segment connecting the ninth coordinate point having a water content of 2.6 g / m ² , the ninth coordinate point and the iodine concentration 10.0 wt. In the area surrounded by the 12th line segment connecting the 5th coordinate point of% and the water content of 0.7 g / m ² and the 5th line segment connecting the 1st coordinate point and the 5th coordinate point. It is characterized by having the concentration of iodine contained and the amount of water.
The polarizing film film laminate with an adhesive layer of this embodiment comprehensively solves the problems of "polyene formation", "color loss", "heat redness", and "deterioration of antistatic function over time". can do.

In the polarizing film film laminate of the above aspect, the eighth coordinate point has an iodine concentration of 4.5 wt. % And the sixth coordinate point having a water content of 2.0 g / m ² , and the ninth coordinate point has an iodine concentration of 7.2 wt. It may be the tenth coordinate point of% and the water content of 2.0 g / m ^2.

Further, 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, it is preferable that the polarizing film contains zinc.

Further, in the polarizing film film laminate of the above aspect, heating of 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 95 ° C./500 hours. It is preferable that the single transmittance after heating is the same as or larger than the single transmittance before heating.
Thereby, the problem of polyene formation can be effectively solved.

In the polarizing film film laminate of the above aspect, a sample composed of a polarizing film laminate and a glass plate laminated on both sides of the polarizing film laminate with an adhesive is applied by heat treatment at 95 ° C./500 hours. It is preferable that the amount of change in the orthogonal transmittance at a wavelength of 410 nm is less than 1% and the amount of change in the orthogonal transmittance at a wavelength of 700 nm 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 sample composed of a polarizing film laminate and a glass plate laminated on both sides of the polarizing film laminate with an adhesive is applied by heat treatment at 95 ° C./500 hours. It is preferable that the amount of change in the orthogonal transmittance at a wavelength of 410 nm is 1% or more and the amount of change in the orthogonal transmittance at a wavelength of 700 nm is less than 5%.
Thereby, the problem of heating redness can be effectively solved.

In the polarizing film film laminate of the above aspect, an antireflection layer is provided on the surface of the polarizing film on the visible side via a base material, and the moisture permeability of the antireflection film composed of the base material and the antireflection layer. but, it may be 15g / m ² · 24h or more.

Further, in the polarizing film film laminate of the above aspect, a liquid crystal cell including a liquid crystal layer containing liquid crystal molecules oriented in one direction in the plane in a state where no electric field is applied, and a first liquid crystal cell arranged on one side of the liquid crystal cell. A polarizing film and a second polarizing film arranged on the other side of the liquid crystal cell so that the absorption axis is orthogonal to the absorption axis of the first polarizing film, the first polarizing film and the said A first retardation layer and a second retardation layer are arranged in order from the side of the first polarizing film with the liquid crystal cell, and the first retardation layer is delayed in the plane. When the refractive index in the phase axis x direction is nx1, the refractive index in the phase advance axis direction is ny1, and the refractive index in the thickness z direction is nz1, the relationship of nx1> ny1> nz1 is satisfied, and the second retardation layer is When the refractive index in the slow axis x direction in the plane is nx2, the refractive index in the phase advance axis direction is ny2, and the refractive index in the thickness z direction is nz2, it is preferable to satisfy the relationship of nz2> nx2 ≧ ny2.

Further, in the polarizing film film laminate of the above aspect, a liquid crystal cell including a liquid crystal layer containing liquid crystal molecules oriented in one direction in the plane in a state where no electric field is applied, and a first liquid crystal cell arranged on one side of the liquid crystal cell. A polarizing film and a second polarizing film arranged on the other side of the liquid crystal cell so that the absorption axis is orthogonal to the absorption axis of the first polarizing film, the first polarizing film and the said A first retardation layer and a second retardation layer are arranged in order from the side of the first polarizing film with the liquid crystal cell, and the first retardation layer is delayed in the plane. When the refractive index in the phase axis x direction is nx1, the refractive index in the phase advance axis direction is ny1, and the refractive index in the thickness z direction is nz1, the relationship of nz1> nx1 = ny1 is satisfied, and the second retardation layer is When the refractive index in the slow axis x direction in the plane is nx2, the refractive index in the phase advance axis direction is ny2, and the refractive index in the thickness z direction is nz2, it is preferable to satisfy the relationship of nx2> ny2 = nz2.

Furthermore, in the polarizing film film laminate of the above aspect, a liquid crystal cell including a liquid crystal layer containing liquid crystal molecules oriented in one direction in the plane in a state where no electric field is applied, and a polarizing film arranged on one side of the liquid crystal cell. A retardation layer is arranged between the polarizing film and the liquid crystal cell, and the retardation layer has an in-plane refractive index in the slow axis x direction of nx and is in the phase advance axis direction. When the refractive index is ny and the refractive index in the thickness z direction is nz, it is preferable to satisfy the relationship of nx> nz> ny.

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 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.

In the optical display panel of the above aspect, the optical display cell may have a built-in touch sensing function.
Alternatively, in the optical display panel of the above aspect, the optical display cell contains a liquid crystal layer containing liquid crystal molecules homogenically oriented in the absence of an electric field, and a first transparent substrate and a second transparent substrate sandwiching the liquid crystal layer on both sides. , And a touch sensing electrode portion related to a touch sensor and a touch drive function may be provided between the first transparent substrate and the second transparent substrate.
In the optical display panel of this aspect, the conductive layer may not be provided on the first transparent substrate on the visual side.

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.

According to the present invention, the problems of "polyene formation", "color loss", "heating redness", and "deterioration of antistatic function over time" can be comprehensively solved.

It is a schematic diagram which shows the layer structure of an optical display panel. It is sectional drawing which shows an example of the liquid crystal panel with a touch sensing function. It is sectional drawing which shows an example of the liquid crystal panel with a touch sensing function. It is sectional drawing which shows an example of the liquid crystal panel with a touch sensing function. It is a figure explaining an example of the manufacturing method of the polarizing film. 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.

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 provides optical display panels, particularly optical display panels attached to the vehicle bodies of automobiles, trains, airplanes, and other powered vehicles that travel by power, and polarizing film laminates used for the optical display panels. 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. Another polarizing film laminate 17 is arranged on the other surface 10b side of the optical display cell 10 via the transparent adhesive 16. The optical display cell 10, the polarizing film laminate 12, and the cover plate 14 are adhered by layers of

transparent adhesives

11 and 13 that fill the space between them without any gaps. 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 17. 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.

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.

An example of the case where the optical display panel of the present invention is a liquid crystal panel with a built-in touch sensing function will be described with reference to the drawings. With reference to FIG. 2, the liquid crystal panel with a built-in touch sensing function is the opposite of the liquid crystal cell C having the liquid crystal layer 23 and the touch sensor unit 25 and the first polarizing film 20 arranged on the visual side of the liquid crystal cell C. It has a second polarizing film 24 arranged on the side, a first pressure-sensitive adhesive layer 21 arranged between the first polarizing film 20 and the liquid crystal cell C. Each of the above-mentioned configurations of the liquid crystal panel with a built-in touch sensing function can be simply shown from the visual side, such as the first polarizing film 20 / first adhesive layer 21 / liquid crystal cell C / second polarizing film 24. In the liquid crystal panel with a built-in touch sensing function, the order of each configuration is simply shown, but other configurations may be appropriately provided between the configurations.

Specific examples of the liquid crystal panel with a built-in touch sensing function are shown in FIGS. 2 to 4, for example.

FIG. 2 is a so-called in-cell type liquid crystal panel with a built-in touch sensing function. From the viewing side, the first polarizing film 20 / first adhesive layer 21 / first transparent substrate 41 / touch sensor unit 25 / liquid crystal layer 23 / It has a structure of a drive electrode / sensor unit 26 / a second transparent substrate 42 / a second adhesive layer 22 / a second polarizing film 24. In the in-cell type liquid crystal panel with a built-in touch sensing function of FIG. 1, for example, the liquid crystal cell C has a touch sensor unit 25 and a drive electrode / sensor in the first and second glass substrates 41 and 42 (inside the liquid crystal cell) sandwiching the liquid crystal layer 23. It has a part 26.

Further, FIG. 3 is a modified example of a so-called in-cell type (semi-in-cell type) liquid crystal panel having a built-in touch sensing function. From the visual side, the first polarizing film 20 / first adhesive layer 21 / touch sensor unit 25 / first It has a configuration of 1 transparent substrate 41 / liquid crystal layer 23 / drive electrode / sensor unit 26 / second transparent substrate 42 / second adhesive layer 22 / second polarizing film 24. In the in-cell type liquid crystal panel with a built-in touch sensing function shown in FIG. 3, for example, the liquid crystal cell C is outside the first transparent substrate 41, and the touch sensor unit 25 is in direct contact with the first adhesive layer 21 and sandwiches the liquid crystal layer 23. A drive electrode / sensor unit 26 is provided on the side of the second transparent substrate 42 in the first and second glass substrates 41 and 42 (inside the liquid crystal cell).

Further, FIG. 4 is a so-called on-cell type liquid crystal panel with a built-in touch sensing function, and from the visual side, the first polarizing film 20 / first adhesive layer 21 / touch sensor unit 25 / drive electrode / sensor unit 26 / first. It has a configuration of 1 transparent substrate 41 / liquid crystal layer 23 / drive electrode 27 / second transparent substrate 42 / second adhesive layer 22 / second polarizing film 24. In the on-cell type liquid crystal panel with a built-in touch sensing function of FIG. 4, for example, the liquid crystal cell C has a touch sensor unit 25 and a drive electrode / sensor unit 26 outside the first transparent substrate 41, and the touch sensor unit 25 is the first. A drive electrode 27 is provided on the side of the second transparent substrate 42 in the first and second glass substrates 41 and 42 (inside the liquid crystal cell) that is in direct contact with the pressure-sensitive adhesive layer 21 and sandwiches the liquid crystal layer 23.

In the liquid crystal cell C, the first transparent substrate 41 and the second transparent substrate 42 can form a liquid crystal cell with the liquid crystal layer 23 interposed therebetween. A touch sensor unit 25, a drive electrode / sensor unit 26, a drive electrode 27, and the like are formed inside or outside the liquid crystal cell, depending on the form of the liquid crystal panel with a built-in touch sensing function. Further, a color filter substrate can be provided on the liquid crystal cell (first transparent substrate 41).

Examples of the material for forming the transparent substrate include glass or a polymer film. Examples of the polymer film include polyethylene terephthalate, polycycloolefin, polycarbonate and the like. When the transparent substrate is made of glass, its thickness is, for example, about 0.3 mm to 1 mm. When the transparent substrate is formed of a polymer film, its thickness is, for example, about 10 μm to 200 μm. The transparent substrate may have an easy-adhesion layer or a hard coat layer on its surface.

The touch sensor unit 25 (capacitance sensor), the drive electrode / sensor unit 26, and the drive electrode 27 are formed as a transparent conductive layer. The constituent material of the transparent conductive layer is not particularly limited, and for example, metals such as gold, silver, copper, platinum, palladium, aluminum, nickel, chromium, titanium, iron, cobalt, tin, magnesium, tungsten, and these metals. Examples include alloys. Examples of the constituent material of the transparent conductive layer include metal oxides of indium, tin, zinc, gallium, antimony, zirconium, and cadmium, and specifically, indium oxide, tin oxide, titanium oxide, cadmium oxide, and these. Examples thereof include metal oxides composed of a mixture of the above. In addition, other metal compounds made of copper iodide or the like are used. The metal oxide may further contain oxides of the metal atoms shown in the above group, if necessary. For example, indium oxide (ITO) containing tin oxide, tin oxide containing antimony, and the like are preferably used, and ITO is particularly preferably used. The ITO preferably contains 80 to 99% by weight of indium oxide and 1 to 20% by weight of tin oxide.

There is no limitation on the place where the touch sensor layer 25 is formed in the liquid crystal cell C, and the touch sensor layer 25 is formed according to the form of the liquid crystal panel with a built-in touch sensing function. For example, in FIGS. 2 to 4, the case where the touch sensor layer 25 is arranged between the first polarizing film 20 and the liquid crystal layer 23 is exemplified. The touch sensor layer 25 can be formed as a transparent electrode pattern on the first transparent substrate 41, for example. As for the drive electrode / sensor unit 26 and the drive electrode 27, a transparent electrode pattern can be formed according to a conventional method according to the form of the liquid crystal panel with a built-in touch sensing function. The transparent electrode pattern is usually electrically connected to a routing wire (not shown) formed at the end of the transparent substrate, and the routing wire is connected to a controller IC (not shown). As the shape of the transparent electrode pattern, in addition to the comb shape, any shape such as a stripe shape or a rhombus shape can be adopted depending on the application. The height of the transparent electrode pattern is, for example, 10 nm to 100 nm, and the width is 0.1 mm to 5 mm.

[Adhesive composition]
The pressure-sensitive adhesive composition that can be used for the transparent adhesive 11 and the like will be described.

The pressure-sensitive adhesive composition used in the present invention contains a pressure-sensitive adhesive polymer containing a polar group-containing monomer as a monomer unit, and an ionic compound.

<Adhesive polymer>
The pressure-sensitive adhesive polymer is not particularly limited as long as it is a polymer having adhesiveness, which is generally used as a base polymer for pressure-sensitive adhesives, but Tg is 0 ° C. or lower (usually -100 ° C.) for the reason that the adhesive performance can be easily balanced. A polymer of ° C. or higher) is suitable. Among such pressure-sensitive adhesive polymers, (meth) acrylic polymers and the like are preferably used.

The (meth) acrylic polymer usually contains an alkyl (meth) acrylate as a main component as a monomer unit. The (meth) acrylate means acrylate and / or methacrylate.

Examples of the alkyl (meth) acrylate constituting the main skeleton of the (meth) acrylic polymer include those having 1 to 18 carbon atoms of a linear or branched alkyl group. For example, the alkyl group includes methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, amyl group, hexyl group, cyclohexyl group, heptyl group, 2-ethylhexyl group, isooctyl group, nonyl group and decyl. Examples thereof include a group, an isodecyl group, a dodecyl group, an isomyristyl group, a lauryl group, a tridecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, an octadecyl group and the like. These can be used alone or in combination. The average carbon number of these alkyl groups is preferably 3 to 9.

A polar group-containing monomer is a compound containing a polar group in its structure and containing a polymerizable unsaturated double bond such as a (meth) acryloyl group or a vinyl group. Specific examples of the polar group-containing monomer include (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-isopropylacrylamide, N-methyl (meth) acrylamide, and N-. Butyl (meth) acrylamide, N-hexyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methylol-N-propane (meth) acrylamide, aminomethyl (meth) acrylamide, aminoethyl (meth) acrylamide, mercaptomethyl Acrylamide-based monomers such as (meth) acrylamide and mercaptoethyl (meth) acrylamide; N-acrylloyl heterocyclic monomers such as N- (meth) acryloylmorpholin, N- (meth) acryloylpiperidin, and N- (meth) acryloylpyrrolidin; Examples thereof include N-vinyl group-containing lactam-based monomers such as vinylpyrrolidone and N-vinyl-ε-caprolactam; alkoxyalkyl (meth) acrylates such as methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate.
The polar group-containing monomer is preferable in order to suppress an increase in the surface resistance value of the pressure-sensitive adhesive layer over time (particularly in a humidified environment) and to satisfy durability. In particular, N-vinyl group-containing lactam-based monomers and alkoxyalkyl (meth) acrylates are preferable, and N-vinylpyrrolidone and methoxyethyl acrylate are particularly preferable.

The weight ratio of the polar group-containing monomer to all the monomer components constituting the pressure-sensitive adhesive polymer is 0.1 to 30 weight from the viewpoint of suppressing an increase in the surface resistance value of the pressure-sensitive adhesive layer over time (particularly in a humid environment). %. The weight ratio is preferably 1% by weight or more, more preferably 3% by weight or more, still more preferably 5% by weight or more. On the other hand, if the weight ratio becomes too large, the polyene formation of the polarizing film tends to deteriorate. Therefore, the weight ratio is preferably 25% by weight or less, and more preferably 20% by weight or less.

Further, an alkyl (meth) acrylate containing an aromatic ring such as phenoxyethyl (meth) acrylate and benzyl (meth) acrylate can be used. The alkyl (meth) acrylate containing an aromatic ring can be used by mixing a polymer obtained by polymerizing the same with the above-exemplified (meth) acrylic polymer, but from the viewpoint of transparency, it contains an aromatic ring. The alkyl (meth) acrylate is preferably used by copolymerizing with the alkyl (meth) acrylate.

One or more of the (meth) acrylic polymers having a polymerizable functional group having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group for the purpose of improving adhesiveness and heat resistance. The copolymerization monomer of can be introduced by copolymerization. Specific examples of such a copolymerization monomer include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 6 (meth) acrylate. Hydroxyl group-containing monomers such as -hydroxyhexyl, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate and (4-hydroxymethylcyclohexyl) -methylacrylate. Carboxyl group-containing monomers such as (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid; acid anhydrides such as maleic anhydride and itaconic anhydride Material-containing monomer; caprolactone adduct of acrylic acid; styrene sulfonic acid, allyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) acrylamide propane sulfonic acid, sulfopropyl (meth) acrylate, ( Meta) Examples thereof include sulfonic acid group-containing monomers such as acryloyloxynaphthalene sulfonic acid; and phosphoric acid group-containing monomers such as 2-hydroxyethyl acryloyl phosphate.

Among the above-mentioned copolymerized monomers, for example, carboxyl groups such as acrylic acid, (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Containing monomer: Acid anhydride group-containing monomer such as maleic anhydride and itaconic anhydride; caprolactone adduct of acrylic acid; styrene sulfonic acid and allyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) ) Sulfonic acid group-containing monomers such as acrylamide propanesulfonic acid, sulfopropyl (meth) acrylate, and (meth) acryloyloxynaphthalene sulfonic acid; acid components such as phosphoric acid group-containing monomers such as 2-hydroxyethylacryloyl phosphate are the pressure-sensitive adhesive layer. Although it is effective in improving the durability (suppressing peeling), when it is used excessively, it has an adverse effect on the polyene formation of the polarizing film, and the reworkability of the adhesive layer tends to decrease.

When an acid component is present, it is considered that an acid of a relatively weak acid system such as a carboxyl group-containing monomer is preferable from the viewpoint of the adverse effect of the acid, followed by a phosphoric acid group-containing monomer and a sulfonic acid group-containing. It may be a monomer or the like.

The upper limit of the amount of the acid component is less than 5% by weight, preferably less than 3% by weight, and more preferably less than 2% by weight, based on the amount of all the monomer components constituting the pressure-sensitive adhesive polymer. The lower limit of the amount of the acid component is preferably 0.01% by weight or more, more preferably 0.2% by weight or more, and further preferably 0.5% by weight or more based on the amount of all the monomer components constituting the pressure-sensitive adhesive polymer. preferable. If the amount of the acid component is small, the durability of the pressure-sensitive adhesive layer tends to decrease.

Examples of the monomer used for the purpose of modification include alkylamino (meth) acrylate such as aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, and t-butylaminoethyl (meth) acrylate. Alkyl-based monomers; vinyl acetate, vinyl propionate, methylvinylpyrrolidone, vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole, vinylimidazole, vinyloxazole, vinylmorpholin, N-vinylcarboxylic acid amides, styrene , Α-Methylstyrene, N-vinylcaprolactam and other vinyl-based monomers; cyanoacrylate-based monomers such as acrylonitrile and methacrylonitrile; epoxy group-containing acrylic monomers such as glycidyl (meth) acrylate; (meth) polyethylene glycol acrylate. Glycol-based acrylic ester monomers such as (meth) acrylate glycol glycol, (meth) methoxyethylene glycol acrylate, (meth) methoxypolypropylene glycol; tetrahydrofurfuryl (meth) acrylate, fluorine (meth) acrylate, silicone. Acrylic acid ester-based monomers such as (meth) acrylate and 2-methoxyethyl acrylate can also be used. Further, isoprene, butadiene, isobutylene, vinyl ether and the like can be mentioned.

Further, as a copolymerizable monomer other than the above, a silane-based monomer containing a silicon atom and the like can be mentioned. Examples of the silane-based monomer include 3-acryloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 4-vinylbutyltrimethoxysilane, 4-vinylbutyltriethoxysilane, and 8-vinyloctyltrimethoxysilane. , 8-Vinyloctyloxydecyltriethoxysilane, 10-methacryloyloxydecyltrimethoxysilane, 10-acryloyloxydecyltrimethoxysilane, 10-methacryloyloxydecyltriethoxysilane, 10-acryloyloxydecyltriethoxysilane and the like.

Examples of the copolymerization monomer include tripropylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, and neo. Pentyl glycol di (meth) acrylate, trimethyl propantri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate , Caprolactone-modified dipentaerythritol Hexa (meth) Acrylate and other (meth) acrylic acids and polyhydric alcohols such as esterified products such as (meth) acryloyl groups, vinyl groups and other unsaturated double bonds having two or more unsaturated double bonds Polyester (meth) acrylates and epoxys (meth) acrylates and epoxys in which two or more unsaturated double bonds such as (meth) acryloyl groups and vinyl groups are added as functional groups similar to the monomer components to the skeletons of sex monomers, polyesters, epoxys, urethanes, etc. Meta) acrylate, urethane (meth) acrylate and the like can also be used.

Among these copolymerizable monomers, a hydroxyl group-containing monomer and a carboxyl group-containing monomer are preferably used from the viewpoint of adhesiveness and durability. A hydroxyl group-containing monomer and a carboxyl group-containing monomer can be used in combination. These copolymerizable monomers serve as reaction points with the cross-linking agent when the pressure-sensitive adhesive composition contains the cross-linking agent. Since the hydroxyl group-containing monomer and the carboxyl group-containing monomer are highly reactive with the intermolecular cross-linking agent, they are preferably used for improving the cohesiveness and heat resistance of the obtained pressure-sensitive adhesive layer. The hydroxyl group-containing monomer is preferable in terms of reworkability, and the carboxyl group-containing monomer is preferable in terms of achieving both durability and reworkability.
The hydroxyl group-containing monomer is contained in an amount of about 0.01 to 30% by weight, preferably about 0.03 to 20% by weight, more preferably about 0.05 to 10% by weight, based on all the monomer components constituting the pressure-sensitive adhesive polymer. Can be used.

In addition to the above, the copolymerization monomer other than the acid component is about 0 to 30% by weight, preferably about 0.1 to 20%, and more preferably about 0.1 to 10% of all the monomer components constituting the pressure-sensitive adhesive polymer. Can be used in the amount of.

The weight average molecular weight (Mw) of the pressure-sensitive adhesive polymer used in the present invention is preferably 900,000 to 3,000,000. Considering durability, particularly heat resistance, the weight average molecular weight is more preferably 1.2 million to 2.5 million. When the weight average molecular weight is smaller than 900,000, the polymer component having a low molecular weight increases and the crosslink density of the gel (adhesive layer) becomes high, which makes the adhesive layer hard and impairs stress relaxation property. , Not preferable. Further, when the weight average molecular weight is larger than 3 million, the viscosity increases and gelation occurs during the polymerization of the polymer, which is not preferable.

The degree of polydispersity (weight average molecular weight (Mw) / number average molecular weight (Mn)) of the pressure-sensitive adhesive polymer used in the present invention is preferably 3.0 or less, more preferably 1.05 to 2.5. Yes, more preferably 1.05 to 2.0. When the degree of polydispersity (Mw / Mn) exceeds 3.0, the amount of low molecular weight polymer increases, and it is necessary to use a large amount of cross-linking agent in order to increase the gel fraction of the pressure-sensitive adhesive layer. , The excess cross-linking agent reacts with the polymer that has already gelled, and the cross-linking density of the gel (adhesive layer) increases, which makes the pressure-sensitive adhesive layer harder and impairs stress relaxation properties, which is preferable. Absent. In addition, when there are many low molecular weight polymers and a large amount of uncrosslinked polymers and oligomers (sol content), segregation occurs near the interface of the adhesive layer in contact with the adherend under heating and humidifying conditions. It is presumed that the crosslinked polymer or the like causes the pressure-sensitive adhesive layer to be destroyed, causing the pressure-sensitive adhesive layer to peel off. The weight average molecular weight and the degree of polydispersity (Mw / Mn) are measured by GPC (gel permeation chromatography) and obtained from the values calculated by polystyrene conversion.

For the production of the pressure-sensitive adhesive polymer used in the present invention, known production methods such as solution polymerization, bulk polymerization, emulsion polymerization, and various radical polymerizations can be appropriately selected. Further, the obtained pressure-sensitive adhesive polymer may be any of a random copolymer, a block copolymer, a graft copolymer and the like.

In solution polymerization, for example, ethyl acetate, toluene and the like are used as the polymerization solvent. As a specific example of solution polymerization, the reaction is carried out under the reaction conditions of about 10 minutes to 30 hours at about 50 to 70 ° C. by adding a polymerization initiator under an inert gas stream such as nitrogen. In particular, by shortening the polymerization time to about 30 minutes to 3 hours, the formation of low molecular weight oligomers produced in the latter stage of polymerization is suppressed, and the degree of polydispersity (Mw / Mn) is adjusted to a preferable range of 3.0 or less. be able to.

The polymerization initiator, chain transfer agent, emulsifier, etc. used for radical polymerization are not particularly limited and can be appropriately selected and used. The weight average molecular weight of the (meth) acrylic polymer can be controlled by the amount of the polymerization initiator and the chain transfer agent used, and the reaction conditions, and the amount of the (meth) acrylic polymer used is appropriately adjusted according to these types.

Examples of the polymerization initiator include 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-amidinopropane) dihydrochloride, and 2,2'-azobis [2- (5-methyl-2). -Imidazoline-2-yl) propane] dihydrochloride, 2,2'-azobis (2-methylpropionamidine) disulfate, 2,2'-azobis (N, N'-dimethyleneisobutylamidine), 2,2 Azo-based initiators such as'-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate (manufactured by Wako Pure Chemical Industries, Ltd., VA-057), persulfates such as potassium persulfate and ammonium persulfate. , Di (2-ethylhexyl) peroxydicarbonate, di (4-t-butylcyclohexyl) peroxydicarbonate, di-sec-butylperoxydicarbonate, t-butylperoxyneodecanoate, t-hexylper Oxypivalate, t-butylperoxypivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, di (4) Peroxides such as -methylbenzoyl) peroxide, dibenzoyl peroxide, t-butylperoxyisobutyrate, 1,1-di (t-hexylperoxy) cyclohexane, t-butylhydroperoxide, hydrogen peroxide, etc. Examples include, but are limited to, initiators, redox-based initiators that combine peroxides and reducing agents, such as combinations of persulfate and sodium hydrogen sulfite, and combinations of peroxide and sodium ascorbate. It's not something.

The polymerization initiator may be used alone or in combination of two or more, but the total content is 0.005 to 1 part by weight with respect to 100 parts by weight of the monomer. It is preferably about 0.02 to 0.5 parts by weight, and more preferably about 0.02 to 0.5 parts by weight.

In order to produce the (meth) acrylic polymer having the weight average molecular weight by using, for example, 2,2'-azobisisobutyronitrile as the polymerization initiator, the amount of the polymerization initiator used is a monomer. It is preferably about 0.06 to 0.2 parts by weight, more preferably about 0.08 to 0.175 parts by weight, based on 100 parts by weight of the total amount of the components.

Examples of the chain transfer agent include lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, 2-mercaptoethanol, thioglycolic acid, 2-ethylhexyl thioglucolate, and 2,3-dimercapto-1-propanol. The chain transfer agent may be used alone or in combination of two or more, but the total content is 0.1 part by weight with respect to 100 parts by weight of the total amount of the monomer components. It is below the degree.

Examples of the emulsifier used in the case of emulsion polymerization include anionic emulsifiers such as sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzene sulfonate, ammonium polyoxyethylene alkyl ether sulfate, and sodium polyoxyethylene alkyl phenyl ether sulfate, and polyoxy. Examples thereof include nonionic emulsifiers such as ethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, and polyoxyethylene-polyoxypropylene block polymer. These emulsifiers may be used alone or in combination of two or more.

Further, as an emulsifier into which a radically polymerizable functional group such as a propenyl group or an allyl ether group has been introduced as a reactive emulsifier, specifically, for example, Aqualon HS-10, HS-20, KH-10, BC-05. , BC-10, BC-20 (all manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), Adecaria Soap SE10N (manufactured by Asahi Denko Co., Ltd.) and the like. Since the reactive emulsifier is incorporated into the polymer chain after polymerization, it has good water resistance and is preferable. The amount of the emulsifier used is more preferably 0.3 to 5 parts by weight and 0.5 to 1 part by weight from the viewpoint of polymerization stability and mechanical stability with respect to 100 parts by weight of the total amount of the monomer components.

The pressure-sensitive adhesive polymer used in the present invention is usually one having a weight average molecular weight in the range of 300,000 to 4,000,000. Considering durability, particularly heat resistance, it is preferable to use one having a weight average molecular weight of 500,000 to 3,000,000. Further, it is more preferably 650,000 to 2 million. If the weight average molecular weight is less than 300,000, it is not preferable in terms of heat resistance. Further, when the weight average molecular weight is larger than 4 million, the adhesiveness and adhesive strength are lowered, which is also not preferable. The weight average molecular weight is a value measured by GPC (gel permeation chromatography) and calculated in terms of polystyrene.

The pressure-sensitive adhesive composition of the present invention contains an ionic compound. As the ionic compound, an alkali metal salt and / or an organic cation-anionic salt can be preferably used. As the alkali metal salt, an organic salt and an inorganic salt of the alkali metal can be used. In the present specification, the "organic cation-anion salt" refers to an organic salt whose cation portion is composed of an organic substance, and the anion portion may be an organic substance or an inorganic substance. There may be. The "organic cation-anionic salt" is also referred to as an ionic liquid or an ionic solid.

<Alkali metal salt>
Examples of the alkali metal ion constituting the cation part of the alkali metal salt include lithium, sodium, and potassium ions. Among these alkali metal ions, lithium ions are preferable.

The anionic portion of the alkali metal salt may be composed of an organic substance or an inorganic substance. The anion portion of the organic salt, for _{^{_{example, CH 3 COO -, CF 3}}} COO -, CH 3 SO 3 -, CF 3 SO 3 -, (CF 3 SO 2) 3 C -, C 4 F 9 SO 3 ^{_{_{^{-, C 3 F 7 COO -}}}} , (CF 3 SO 2) (CF 3 CO) N -, -O 3 S (CF 2) 3 SO 3 -, PF 6 -, CO 3 2-, or the following general formula ( 1) to (4), (1) :( C n F 2n + 1 SO 2) 2 n - ( where, n is an integer of from 1 to _{10), (2): CF 2} (C m F 2m SO 2) ₂ N ^- (where, m is an integer of from 1 to 10), (3): - O 3 S (CF 2) l SO 3 - ( where, l is an integer of from 1 to 10), (4) :( C _p _{_{^{F 2p + 1 SO 2) N}}} - (C q F 2q + 1 SO 2), ( where, p, q is an integer of 1 to 10), in represented by those such as are used. In particular, the anion portion containing a fluorine atom is preferably used because an ionic compound having good ionic dissociation property can be obtained. The anion portion constituting the inorganic ^{^{^{salts, Cl -, Br -, I}}} -, AlCl 4 -, Al 2 Cl 7 -, BF 4 -, PF 6 -, ClO 4 -, NO 3 -, AsF 6 -, SbF _{^{_{^{6 -, NbF 6 -, TaF}}}} 6 -, (CN) 2 N -, and the like can be used. Examples of the anionic _{_{_{portion, (CF 3 SO 2) 2}}} N -, (C 2 F 5 SO 2) 2 N -, wherein represented by formula (1) etc., (perfluoroalkyl sulfonyl) imide are preferable, especially ( _{_{_{^{CF 3 SO 2) 2 N -}}}} , in represented by (trifluoromethanesulfonyl) imide are preferable.

Specific examples of the organic salt of the alkali metal include sodium acetate, sodium alginate, sodium lignin sulfonate, sodium toluene sulfonate, LiCF ₃ SO ₃ , Li (CF ₃ SO ₂ ) ₂ N, and Li (CF ₃ SO _2). ) ₂ N, Li (C ₂ F ₅ SO ₂ ) ₂ N, Li (C ₄ F ₉ SO ₂ ) ₂ N, Li (CF ₃ SO ₂ ) ₃ C, KO ₃ S (CF ₂ ) ₃ SO ₃ K, _{_{_{LiO 3 S (CF 2) 3}}} SO 3 K , and the like, among these _{_{LiCF 3 SO 3, Li (CF}} 3 SO 2) 2 N, Li (C 2 F 5 SO 2) 2 N, Li (C 4 F ₉ SO ₂ ) ₂ N, Li (CF ₃ SO ₂ ) ₃ C, etc. are preferable, and Li (CF ₃ SO ₂ ) ₂ N, Li (C ₂ F ₅ SO ₂ ) ₂ N, Li (C ₄ F ₉ SO) ₂₎ bis (fluorosulfonyl) more preferably a fluorine-containing lithium imide salt imide lithium salts such as ₂ N, in particular (perfluoroalkyl sulfonyl) imide lithium salts are preferred. In addition, 4,4,5,5-tetrafluoro-1,3,2-dithiazolidine-1,1,3,3-tetraoxide lithium salt and the like can be mentioned.

Inorganic salts of alkali metals include lithium perchlorate and lithium iodide.

<Organic cation-anion salt>
The organic cation-anion salt used in the present invention is composed of a cation component and an anion component, and the cation component is composed of an organic substance. Specific examples of the cation component include pyridinium cation, piperidinium cation, pyrrolidinium cation, pyrroline skeleton cation, pyrrole skeleton cation, imidazolium cation, tetrahydropyrimidinium cation, and dihydropyrimidinium cation. Examples thereof include pyrazolium cation, pyrazolinium cation, tetraalkylammonium cation, trialkylsulfonium cation, tetraalkylphosphonium cation and the like.

The anionic component, ^{^{^{e.g., Cl -, Br -, I}}} -, AlCl 4 -, Al 2 Cl 7 -, BF 4 -, PF 6 -, ClO 4 -, NO 3 -, CH 3 COO -, CF 3 COO ^{_{_{^{-, CH 3 SO 3 -,}}}} CF 3 SO 3 -, (CF 3 SO 2) 3 C -, AsF 6 -, SbF 6 -, NbF 6 -, TaF 6 -, (CN) 2 N -, C 4 F _{_{^{_{9 SO 3 -, C 3 F}}}} 7 COO -, ((CF 3 SO 2) (CF 3 CO) N -, -O 3 S (CF 2) 3 SO 3 -, or the following general formula (1) to (4 _{), (1) :( C n} F 2n + 1 SO 2) 2 n - ( where, n is an integer of from 1 to _{10), (2): CF 2} (C m F 2m SO 2) 2 n - ( where , m integer of 1 ~ 10), (3) : - O 3 S (CF 2) l SO 3 - ( where, l is an integer of from 1 to _{10), (4) :( C p} F 2p + 1 SO _{^{_{2) N -. (C q}}} F 2q + 1 SO 2), ( where, p, q is an integer of 1 to 10), in represented by those such as are used among other things, an anionic component containing a fluorine atom, It is preferably used because an ionic compound having good ionic dissociation property can be obtained.

As the organic cation-anion salt, a compound composed of a combination of the above cation component and an anion component is appropriately selected and used. Preferred specific examples of the organic cation-anion salt include, for example, methyltrioctylammonium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-propylpyrrolidinium bis (trifluoromethanesulfonyl) imide, ethylmethylimidazolium bis ( Fluorosulfonylimide). Of these, 1-methyl-1-propylpyrrolidinium bis (trifluoromethanesulfonyl) imide and ethyl methylimidazolium bis (fluorosulfonylimide) are more preferable.

Examples of the ionic compound include inorganic salts such as ammonium chloride, aluminum chloride, copper chloride, ferric chloride, ferric chloride and ammonium sulfate, in addition to the above-mentioned alkali metal salt and organic cation-anionic salt. ..

The ionic compound may be used alone or in combination of two or more in order to obtain a desired surface resistance value of the pressure-sensitive adhesive layer.

The proportion of the ionic compound in the pressure-sensitive adhesive composition of the present invention can be appropriately adjusted so as to satisfy the antistatic properties of the pressure-sensitive adhesive layer and the sensitivity of the touch panel. For example, the weight ratio and polarization of the polar group-containing monomer introduced into the pressure-sensitive adhesive polymer so that the surface resistance value of the pressure-sensitive adhesive layer is in the range of 1.0 × 10 ⁸ to 1.0 × 10 ^{12 Ω / □.} It is preferable to adjust the ratio of the ionic compound according to the type of the liquid crystal panel with a built-in touch sensing function while considering the type of the transparent protective film of the film. For example, in the in-cell type liquid crystal panel with a built-in touch sensing function shown in FIG. 2, the surface resistance value of the first pressure-sensitive adhesive layer is preferably controlled in the range of ^{1 × 10 8} to 1 × 10 ^{10 Ω / □.} Further, in the semi-in-cell type liquid crystal panel shown in FIG. 3 or the on-cell type liquid crystal panel with a built-in touch sensing function shown in FIG. 4, the surface resistance value of the first adhesive layer is 1 × 10 ¹⁰ to 1 × 10 ¹² Ω / □. It is preferable to control the range.

Further, the first pressure-sensitive adhesive layer is controlled so as to satisfy the fluctuation ratio (b / a) ≤ 5 of the surface resistance value. The a is immediately after producing the first polarizing film with the pressure-sensitive adhesive layer in which the first pressure-sensitive adhesive layer is provided on the first polarizing film and the separator is provided on the first pressure-sensitive adhesive layer. It is the surface resistance value of the first pressure-sensitive adhesive layer when the separator is peeled off, and b is the first polarizing film with the pressure-sensitive adhesive layer put into a humid environment of 60 ° C./95% RH for 250 hours, and further 40. It is the surface resistance value of the first pressure-sensitive adhesive layer when the separator is peeled off after being dried at ° C. for 1 hour. When the fluctuation ratio (b / a) exceeds 5, the antistatic function of the pressure-sensitive adhesive layer in a humidified environment is deteriorated. The fluctuation ratio (b / a) is preferably 5 or less, more preferably 3.5 or less, further preferably 2.5 or less, and further preferably 2 or less. Most preferably, it is 1.5 or less.

The ratio of the ionic compound is preferably 0.01 parts by weight or more with respect to 100 parts by weight of the pressure-sensitive adhesive polymer, for example. It is preferable to use 0.01 part by weight or more of the ionic compound in order to improve the antistatic performance. From this point of view, the ionic compound is preferably 0.1 part by weight or more, more preferably 0.5 part by weight or more. On the other hand, if the amount of the ionic compound increases, the surface resistance value becomes too low, and the sensitivity of the touch panel may decrease due to the baseline fluctuation (malfunction at the time of touch caused by the surface resistance value being too low). Further, when the amount of the ionic compound increases, the ionic compound may be precipitated, and further, humidification peeling is likely to occur. From this point of view, the ionic compound is usually preferably 40 parts by weight or less, more preferably 30 parts by weight or less, further preferably 20 parts by weight or less, and preferably 10 parts by weight or less. Most preferred.
As will be described later, the amount of the ionic compound added to the pressure-sensitive adhesive layer can be reduced by providing the pressure-sensitive adhesive layer on the polarizing film via the conductive layer.

<Other components in the adhesive composition>
Further, the pressure-sensitive adhesive composition used in the present invention may contain a cross-linking agent. As the cross-linking agent, an organic cross-linking agent or a polyfunctional metal chelate can be used. Examples of the organic cross-linking agent include isocyanate-based cross-linking agents, peroxide-based cross-linking agents, epoxy-based cross-linking agents, and imine-based cross-linking agents. A polyfunctional metal chelate is one in which a polyvalent metal is covalently or coordinated to an organic compound. Examples of the polyvalent metal atom include Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn, Ti and the like. can give. Examples of the atom in the organic compound having a covalent bond or a coordination bond include an oxygen atom and the like, and examples of the organic compound include an alkyl ester, an alcohol compound, a carboxylic acid compound, an ether compound and a ketone compound.

As the cross-linking agent, an isocyanate-based cross-linking agent and / or a peroxide-type cross-linking agent is preferable. Examples of the compound related to the isocyanate-based cross-linking agent include isocyanate monomers such as tolylene diisocyanate, chlorphenylene diisocyanate, tetramethylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, and hydrogenated diphenylmethane diisocyanate, and these isocyanate monomers. Examples include isocyanate compounds added with trimetylolpropane and the like, isocyanurates, bullet-type compounds, and urethane prepolymer-type isocyanates which have been subjected to an addition reaction such as polyether polyols, polyester polyols, acrylic polyols, polybutadiene polyols, and polyisoprene polyols. be able to. Particularly preferred is a polyisocyanate compound, which is one selected from the group consisting of hexamethylene diisocyanate, hydrogenated xylylene diisocyanate, and isophorone diisocyanate, or a polyisocyanate compound derived thereto. Here, one selected from the group consisting of hexamethylene diisocyanate, hydrogenated xylylene diisocyanate, and isophorone diisocyanate or a polyisocyanate compound derived thereto includes hexamethylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, and polyol modification. Hexamethylene diisocyanate, polyol-modified hydrogenated xylylene diisocyanate, trimmer-type hydrogenated xylylene diisocyanate, polyol-modified isophorone diisocyanate and the like are included. The exemplified polyisocyanate compound is particularly preferable because the reaction with the hydroxyl group proceeds rapidly by using the acid and the base contained in the polymer as a catalyst, which contributes to the speed of cross-linking.

The peroxide-type cross-linking agent can be appropriately used as long as it generates radically active species by heating or light irradiation to promote cross-linking of the base polymer of the pressure-sensitive adhesive composition, but it is suitable for workability and stability. In consideration, it is preferable to use a peroxide having a half-life temperature of 80 ° C. to 160 ° C. for 1 minute, and more preferably to use a peroxide having a half-life temperature of 90 ° C. to 140 ° C.

Examples of peroxides that can be used as a cross-linking agent include di (2-ethylhexyl) peroxydicarbonate (1 minute half-life temperature: 90.6 ° C.) and di (4-t-butylcyclohexyl) peroxydi. Carbonate (1 minute half-life temperature: 92.1 ° C), di-sec-butylperoxydicarbonate (1 minute half-life temperature: 92.4 ° C), t-butylperoxyneodecanoate (1 minute half-life) Temperature: 103.5 ° C), t-hexyl peroxypivalate (1 minute half-life temperature: 109.1 ° C), t-butyl peroxypivalate (1 minute half-life temperature: 110.3 ° C), dilauroyl Peroxide (1 minute half-life temperature: 116.4 ° C), di-n-octanoyl peroxide (1 minute half-life temperature: 117.4 ° C), 1,1,3,3-tetramethylbutylperoxy- 2-Ethylhexanoate (1 minute half-life temperature: 124.3 ° C), di (4-methylbenzoyl) peroxide (1 minute half-life temperature: 128.2 ° C), dibenzoyl peroxide (1 minute half-life temperature) : 130.0 ° C.), t-Butylperoxyisobutyrate (1 minute half-life temperature: 136.1 ° C.), 1,1-di (t-hexylperoxy) cyclohexane (1 minute half-life temperature: 149. 2 ° C) and the like. Among them, di (4-t-butylcyclohexyl) peroxydicarbonate (1 minute half-life temperature: 92.1 ° C.) and dilauroyl peroxide (1 minute half-life temperature: 116.) Since the cross-linking reaction efficiency is particularly excellent. 4 ° C.), dibenzoyl peroxide (1 minute half-life temperature: 130.0 ° C.) and the like.

The half-life of peroxide is an index showing the decomposition rate of peroxide, and means the time until the residual amount of peroxide is halved. The decomposition temperature for obtaining a half-life at an arbitrary time and the half-life time at an arbitrary temperature are described in the manufacturer's catalog, etc. For example, "Organic peroxide catalog 9th edition" of Nippon Oil & Fats Co., Ltd. (May 2003) ”and so on.

The amount of the cross-linking agent used is preferably 0.01 to 20 parts by weight, more preferably 0.03 to 10 parts by weight, based on 100 parts by weight of the pressure-sensitive adhesive polymer. If the amount of the cross-linking agent is less than 0.01 parts by weight, the cohesive force of the adhesive tends to be insufficient and foaming may occur during heating. On the other hand, if the amount is more than 20 parts by weight, the moisture resistance is not sufficient. Peeling is likely to occur in reliability tests and the like.

One type of the isocyanate-based cross-linking agent may be used alone, or two or more types may be mixed and used, but the content as a whole is as described above with respect to 100 parts by weight of the pressure-sensitive adhesive polymer. The polyisocyanate compound cross-linking agent is preferably contained in an amount of 0.01 to 2 parts by weight, more preferably 0.02 to 2 parts by weight, and preferably 0.05 to 1.5 parts by weight. Is even more preferable. It can be appropriately contained in consideration of cohesive force, prevention of peeling in durability test, and the like.

One type of the peroxide may be used alone, or two or more types may be mixed and used, but the content as a whole is the above amount with respect to 100 parts by weight of the pressure-sensitive adhesive polymer. The oxide is 0.01 to 2 parts by weight, preferably 0.04 to 1.5 parts by weight, and more preferably 0.05 to 1 part by weight. It is appropriately selected within this range in order to adjust workability, reworkability, crosslink stability, peelability and the like.

As a method for measuring the amount of peroxide decomposition remaining after the reaction treatment, for example, HPLC (high performance liquid chromatography) can be used.

More specifically, for example, about 0.2 g of the pressure-sensitive adhesive composition after the reaction treatment is taken out, immersed in 10 ml of ethyl acetate, extracted by shaking at 120 rpm for 3 hours at 25 ° C. with a shaker, and then at room temperature. Let stand for 3 days. Next, 10 ml of acetonitrile was added, and the mixture was shaken at 120 rpm at 25 ° C. for 30 minutes, and about 10 μl of the extract obtained by filtering with a membrane filter (0.45 μm) was injected into HPLC for analysis, and after the reaction treatment. It can be the amount of peroxide.

It is particularly preferable to add a silane coupling agent as an additive. Examples of the silane coupling agent include silicon compounds having an epoxy structure such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane; Amino group-containing silicon compounds such as 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyldimethoxysilane; 3-chloro Propyltrimethoxysilane; (meth) acrylic group-containing silane coupling agent such as acetoacetyl group-containing trimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane; 3-isocyanatepropyltriethoxysilane Such as isocyanate group-containing silane coupling agent and the like can be mentioned. In particular, 3-glycidoxypropyltrimethoxysilane and acetoacetyl group-containing trimethoxysilane are preferably used because they can effectively suppress peeling. The silane coupling agent can impart durability, particularly the effect of suppressing peeling in a humidified environment. The amount of the silane coupling agent used is 1 part by weight or less, more preferably 0.01 to 1 part by weight, preferably 0.02 to 0.6 parts by weight, based on 100 parts by weight of the pressure-sensitive adhesive polymer. If the amount of the silane coupling agent used is large, the adhesive force to the liquid crystal cell is excessively increased, which may affect the reworkability and the like.

Further, the pressure-sensitive adhesive composition used in the present invention may contain other known additives. For example, the pressure-sensitive adhesive composition contains powders such as colorants and pigments, dyes, and surfactants. Plasticizers, tackifiers, surface lubricants, leveling agents, softeners, antioxidants, anti-aging agents, light stabilizers, UV absorbers, polymerization inhibitors, inorganic or organic fillers, metal powders, particulates , Foil-like material and the like can be appropriately added depending on the intended use. Further, a redox system to which a reducing agent is added may be adopted within a controllable range.

A pressure-sensitive adhesive layer is formed by the pressure-sensitive adhesive composition. In forming the pressure-sensitive adhesive layer, it is necessary to adjust the amount of the entire cross-linking agent added and to fully consider the effects of the cross-linking treatment temperature and the cross-linking treatment time. preferable.

It is possible to adjust the cross-linking treatment temperature and cross-linking treatment time depending on the cross-linking agent used. The crosslinking treatment temperature is preferably 170 ° C. or lower.

Further, the cross-linking treatment may be performed at the temperature at the time of the drying step of the pressure-sensitive adhesive layer, or a separate cross-linking treatment step may be provided after the drying step.

The crosslinking treatment time can be set in consideration of productivity and workability, but is usually about 0.2 to 20 minutes, preferably about 0.5 to 10 minutes.
[Adhesive layer]
The pressure-sensitive adhesive layer will be described.

The polarizing film laminate with an adhesive layer of the present invention has an adhesive layer provided on at least one surface of the polarizing film directly or via an optically transparent polarizing film protective film.

As a method of forming the pressure-sensitive adhesive layer, for example, a method of applying the pressure-sensitive adhesive composition to a separator or the like which has been peeled off, drying and removing a polymerization solvent or the like to form a pressure-sensitive adhesive layer, and then transferring the pressure-sensitive adhesive layer to an optical film, or Examples thereof include a method of applying the pressure-sensitive adhesive composition to an optical film and drying and removing a polymerization solvent or the like to form a pressure-sensitive adhesive layer on the optical film. When applying the pressure-sensitive adhesive, one or more solvents other than the polymerization solvent may be newly added as appropriate.

A silicone release liner is preferably used as the release-treated separator. In the step of applying the pressure-sensitive adhesive composition on such a liner and drying it to form a pressure-sensitive adhesive layer, as a method of drying the pressure-sensitive adhesive, an appropriate method can be appropriately adopted depending on the purpose. Preferably, a method of overheating and drying the coating film is used. The heating and drying temperature is preferably 40 ° C. to 200 ° C., more preferably 50 ° C. to 180 ° C., and particularly preferably 70 ° C. to 170 ° C. By setting the heating temperature within the above range, an adhesive layer having excellent adhesive properties can be obtained.

As the drying time, an appropriate time can be adopted as appropriate. The drying time is preferably 5 seconds to 20 minutes, more preferably 5 seconds to 10 minutes, and particularly preferably 10 seconds to 5 minutes.

Further, the pressure-sensitive adhesive layer can be formed after forming an anchor layer on the surface of the polarizing film laminate or performing various easy-adhesion treatments such as corona treatment and plasma treatment. The surface of the pressure-sensitive adhesive layer may be subjected to an easy-adhesion treatment.

When using these, it is desirable that the anchor layer and adhesive layer formed when the pressure-sensitive adhesive layer is provided on the surface of the polarizing film laminate also be an acid-free system.

As a specific method for forming the anchor layer, a solution containing a urethane polymer (manufactured by Nagase ChemteX Corporation: Denatron B510-C, etc.) is solidified with a water / isopropyl alcohol (65:35 volume ratio) mixed solution. The content was adjusted to 0.2% by weight, and the adjusted solution was applied to the polarizing film laminate using Meyerbar # 5 and dried at 50 ° C. for 30 seconds to form an anchor coat layer having a thickness of 25 nm. There is a method of forming.

<Conductive layer>
The polarizing film laminate of the present invention includes a pressure-sensitive adhesive layer containing an ionic compound, and the pressure-sensitive adhesive layer may be provided on the polarizing film via a conductive layer.

Since the antistatic function is improved by providing the conductive layer, even if the amount of the ionic compound added to the pressure-sensitive adhesive layer is reduced and the surface resistance value of the pressure-sensitive adhesive layer is set high, the static electricity unevenness of the liquid crystal display device can be prevented. Can be suppressed. Reducing the amount of ionic compounds added to the pressure-sensitive adhesive layer also tends to reduce the amount of polar monomers required to prevent segregation of the ionic compounds and migration to the polarizing film laminate, resulting in less. It becomes easy to suppress the polyene formation of the polarizing film. Therefore, it is preferable to provide the conductive layer on the polarizing film laminate because it tends to be easy to achieve both deterioration of the antistatic function with time and polyene formation of the polarizing film.

The thickness of the conductive layer is preferably 1 μm or less, preferably 0.01 to 0.5 μm, preferably 0.01, from the viewpoint of stability of the surface resistance value and adhesion to the pressure-sensitive adhesive layer 21. It is preferably about 0.2 μm, and more preferably 0.01 to 0.1 μm. Further, the surface resistance value of the conductive layer ^{is preferably 1 × 10 2} to 1 × 10 ¹² Ω / □ from the viewpoint of the antistatic function, and is preferably 1 × 10 ² to 1 × 10 ¹¹ Ω / □. Is preferable, and more preferably 1 × 10 ² to 1 × 10 ¹⁰ Ω. Further, when the polarizing film laminate of the present invention is applied to a liquid crystal panel having a built-in touch sensing function, the surface resistance value of the conductive layer is 1 × 10 ⁷ to 1 from the viewpoint of achieving both a malfunction of the capacitance sensor and an antistatic function. It is preferably 1 × 10 ¹² Ω / □, preferably 1 × 10 ⁷ to 1 × 10 ¹¹ Ω / □, and more preferably 1 × 10 ⁷ to 1 × 10 ¹⁰ Ω.

The conductive layer can be formed from various antistatic agent compositions. As the antistatic agent forming the conductive layer, an ionic surfactant system, a conductive polymer, conductive fine particles, carbon nanotubes and the like can be used.

Among these antistatic agents, conductive polymers and carbon nanotubes are preferably used from the viewpoint of optical properties, appearance, antistatic effect, and stability of the antistatic effect during heat and humidification. In particular, conductive polymers such as polyaniline and polythiophene are preferably used. As the conductive polymer, an organic solvent-soluble, water-soluble, or water-dispersible polymer can be appropriately used, but a water-soluble conductive polymer or a water-dispersible conductive polymer is preferably used. The water-soluble conductive polymer and the water-dispersible conductive polymer can be prepared as an aqueous solution or an aqueous dispersion as a coating liquid for forming the antistatic layer, and the coating liquid does not need to use a non-aqueous organic solvent and is organic. This is because the deterioration of the optical film base material due to the solvent can be suppressed. The aqueous solution or the aqueous dispersion can contain an aqueous solvent in addition to water. For example, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec-amyl alcohol, tert-amyl alcohol, 1-ethyl-1. -Alcohols such as propanol, 2-methyl-1-butanol, n-hexanol, cyclohexanol and the like can be mentioned.

Further, the water-soluble conductive polymer such as polyaniline and polythiophene or the water-dispersible conductive polymer preferably has a hydrophilic functional group in the molecule. Examples of the hydrophilic functional group include a sulfon group, an amino group, an amide group, an imino group, a quaternary ammonium base, a hydroxyl group, a mercapto group, a hydrazino group, a carboxyl group, a sulfate ester group, a phosphoric acid ester group, or a salt thereof. And so on. By having a hydrophilic functional group in the molecule, it becomes easy to be dissolved in water or dispersed in water in the form of fine particles, and the water-soluble conductive polymer or the water-dispersible conductive polymer can be easily prepared.

Examples of commercially available water-soluble conductive polymers include polyaniline sulfonic acid (manufactured by Mitsubishi Rayon, weight average molecular weight of 150,000 in terms of polystyrene). Examples of commercially available water-dispersible conductive polymers include polythiophene-based conductive polymers (manufactured by Nagase Chemtech, trade name, Denatron series).

Further, as a material for forming the conductive layer, a binder component can be added together with the antistatic agent for the purpose of improving the film-forming property of the antistatic agent and the adhesion to the optical film. When the antistatic agent is a water-soluble conductive polymer or a water-based material of the water-dispersible conductive polymer, a water-soluble or water-dispersible binder component is used. Examples of binders include oxazoline group-containing polymers, polyurethane resins, polyester resins, acrylic resins, polyether resins, cellulose resins, polyvinyl alcohol resins, epoxy resins, polyvinylpyrrolidone, polystyrene resins, polyethylene glycol, etc. Examples include pentaerythritol. In particular, polyurethane-based resins, polyester-based resins, and acrylic-based resins are preferable. One or two or more of these binders can be appropriately used according to the intended use.

The amount of antistatic agent and binder used depends on their types, but it is preferable to control the surface resistance value of the obtained conductive layer within an appropriate range.

Various methods are used as the method for forming the pressure-sensitive adhesive layer. Specifically, for example, roll coat, kiss roll coat, gravure coat, reverse coat, roll brush, spray coat, dip roll coat, bar coat, knife coat, air knife coat, curtain coat, lip coat, die coater, etc. Examples include a method such as an extrusion coating method.

The thickness of the pressure-sensitive adhesive layer is not particularly limited, and is, for example, about 1 to 500 μm. It is preferably 1 to 250 μm, more preferably 1 to 100 μm, and even more preferably 1 to 35 μm.
By reducing the thickness of the pressure-sensitive adhesive layer, the total amount of acid in the pressure-sensitive adhesive with respect to the polarizing film can be reduced, and the influence on the polyene formation of the polarizing film laminate with the pressure-sensitive adhesive layer can be reduced.
In addition, the adhesive strength usually decreases as the thickness of the adhesive layer decreases, and the adhesive durability such as floating and peeling decreases due to the shrinkage stress of the polarizing plate due to the shrinkage of the polarizing film under high temperature and high humidity. There is a tendency, and it is not preferable to reduce the thickness of the pressure-sensitive adhesive layer. However, by reducing the thickness of the polarizing film, the shrinkage stress of the polarizing plate can be reduced, and as a result, the adhesive durability can be maintained or improved even if the thickness of the adhesive layer is reduced.

When the pressure-sensitive adhesive layer is exposed, the pressure-sensitive adhesive layer may be protected by a sheet (separator) that has been peeled off until it is put into practical use.

Examples of the constituent material of the separator include plastic films such as polyethylene, polypropylene, polyethylene terephthalate, and polyester film, porous materials such as paper, cloth, and non-woven fabric, nets, foam sheets, metal foils, and laminates thereof. A thin leaf body can be mentioned, but a plastic film is preferably used because of its excellent surface smoothness.

The plastic film is not particularly limited as long as it can protect the pressure-sensitive adhesive layer, and is, for example, a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, a polyvinyl chloride film, and a vinyl chloride co-weight. Examples thereof include a coalesced film, a polyethylene terephthalate film, a polybutylene terephthalate film, a polyurethane film, and an ethylene-vinyl acetate copolymer film.

The thickness of the separator is usually about 5 to 200 μm, preferably about 5 to 100 μm. If necessary, the separator may be used for mold release and antifouling treatment with a silicone-based, fluorine-based, long-chain alkyl-based or fatty acid amide-based mold release agent, silica powder, etc., as well as a coating type, a kneading type, and a vapor deposition type. It is also possible to apply antistatic treatment such as. In particular, the peelability of the separator from the pressure-sensitive adhesive layer can be further enhanced by appropriately performing a peeling treatment such as a silicone treatment, a long-chain alkyl treatment, or a fluorine treatment on the surface of the separator.

The peeled sheet used in the production of the polarizing film laminate with the adhesive layer can be used as it is as a separator for the polarizing film laminate with the adhesive layer, thereby simplifying the process. Can be done.

2. 2. Polarizing film laminate With reference to FIG. 1 again, the polarizing film laminate 12 includes at least one of the polarizing film 120 and at least one surface of the polarizing film 120, for example, the polarizing film protective film 121 bonded to the visible side. Including. As in the present embodiment, the polarizing film is protected on both sides of the polarizing film 120, that is, on both the viewing side and the opposite side of the polarizing film 120 via an appropriate adhesive (not shown). The

films

121 and 122 may be bonded, respectively. 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 comprehensively solves the problems that occur in a high temperature or high humidity environment, particularly the problems of "polyene formation", "color loss", and "heat redness", and in particular, the iodine concentration of the polarizing film 120. We are paying attention to (wt.%) And the water content (g / m2) 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 of the aerial auxiliary stretching treatment (B), the laminate 7 containing the PVA layer 2 having a thickness of 7 μm is stretched integrally with the PET base material 6, and the “stretched laminate 8” containing the PVA layer 2 having a thickness of 5 μm 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 Examples of the material constituting the polarizing film

protective films

121 and 122 include thermoplastic resins having excellent transparency, mechanical strength, and thermal stability. Specific examples of such thermoplastic resins include cellulose-based resins such as triacetyl cellulose, polyester-based resins, 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 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 may contain one or more kinds of arbitrary additives. Examples of the additive include an ultraviolet absorber, an antioxidant, a lubricant, a plasticizer, a mold release agent, a colorant, a flame retardant, a nucleating agent, an antistatic agent, a pigment, a colorant and the like.

2-3. The other optical film The polarizing film and the polarizing film protective film 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 film 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. Adhesives For bonding the polarizing film 120 and the polarizing film

protective films

121 and 122, or for bonding other optical films such as retardation films and them, for example, a radical polymerization curable adhesive or a cationic polymerization curable adhesive. Agents and water-based adhesives 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. As the radically polymerizable compound, only one kind may be used alone, or two or more kinds 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 with an adhesive layer, that is, polyene formation, color loss, heat redness, and "deterioration of antistatic function over time" 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. It is speculated that this decrease is due to polyene formation of PVA. Polyene refers to − (CH = CH) _n − and can be formed in a polarizing film by heating. Polyenes significantly reduce the transmittance of the polarizing film. Further, in a high temperature and high humidity environment, the PVA-polyiodine complex is easily ^{destroyed to generate I −} and I _2.
As shown in Chemical Formula 1 below, PVA polyeneization is thought to occur when the dehydration reaction is promoted by heating _{with iodine (I 2) produced in a high-temperature and high-humidity environment.}
(Chemical formula 1)

_{I 2} generated when the PVA-polyiodine complex existing in the polarizing film is broken by heating and the OH group in PVA form a charge transfer complex (HO ... I ₂ ), and then polyene via the OI group. It is thought that it will become. When the pressure-sensitive adhesive layer contains a large amount of polar group-containing monomers, it is considered that the amount of water contained in the pressure-sensitive adhesive layer increases and the moisture permeability of the pressure-sensitive adhesive layer decreases, further promoting polyene formation.

<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 under high temperature and high humidity, hydrolysis of boric acid cross-linking occurs, the orientation of PVA is lowered, and the PVA polyiodine complex is disintegrated. 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 the polarizing film placed under high temperature and high humidity, color loss occurs in the 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, this PVA-I ₅ ^- complex is vulnerable to heating, and when the polarizing film is placed at a high temperature, the complex formation _{between PVA and I 5} ^-- _{complexes and I 5} ^-- is decomposed.
Therefore, in the polarizing film placed at a high temperature, the PVA-I ₅ ^- complex responsible for absorption on the long wavelength side decreases, that is, the transmittance on the long wavelength side of about 700 nm increases, and the polarizing film turns red. Resulting in.

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 /)". Samples of various polarizing film laminates with different m ^{2) ”were prepared.}

<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 (% by weight) 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. ^{R 2} in FIG. 6 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.

(Creation of adhesive layer A)
First, 70.9 parts of butyl acrylate, 18 parts of benzyl acrylate, 5 parts of methoxyethyl acrylate, 5 parts of N-vinylpyrrolidone, and acrylic in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a cooler. A monomer mixture was obtained by charging 1 part of acid and 0.1 part of 4-hydroxybutyl acrylate. Further, 0.1 part of 2,2'-azobisisobutyronitrile was charged together with 100 parts of ethyl acetate as a polymerization initiator with respect to 100 parts of the monomer mixture (solid content). Nitrogen gas was introduced into the flask and replaced with nitrogen while gently stirring the mixture. A solution of an acrylic polymer having a weight average molecular weight (Mw) of 1.7 million and Mw / Mn = 3.9 was prepared by carrying out a polymerization reaction for 8 hours while maintaining the liquid temperature in the flask at around 55 ° C.

Next, with respect to 100 parts of the solid content of the acrylic polymer solution, 0.45 parts of an isocyanate cross-linking agent (Coronate L manufactured by Toso Co., Ltd., Trimethylol propanetolylene diisocyanate) and benzoyl sulfide (manufactured by Nippon Oil & Fats Co., Ltd .: Niper) BMT) 0.1 part, bis (trifluoromethanesulfonyl) imidelithium (LiTFSI, manufactured by Mitsubishi Materials) 5 parts and γ-glycidoxypropylmethoxysilane (manufactured by Shinetsu Chemical Industry Co., Ltd .: KBM-403) 0.2 parts A solution of the acrylic pressure-sensitive adhesive composition was prepared by further blending.

Next, the obtained solution was applied to one side of a separator (MRF38 manufactured by Mitsubishi Chemical Polyester Film Corporation). The separator was a polyethylene terephthalate film treated with a silicone-based release agent. The obtained coating film was dried at 155 ° C. for 1 minute to form an adhesive layer A on the surface of the separator. The thickness of the pressure-sensitive adhesive layer was 20 μm.

(Creation of adhesive layer B)
First, 99 parts by weight of butyl acrylate (hereinafter the same), 1.0 part of 4-hydroxybutyl acrylate, and 2,2 in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube and a cooler. '-0.3 parts of azobisisobutyronitrile was charged with 100 parts of ethyl acetate. Nitrogen gas was introduced into the flask and replaced with nitrogen while gently stirring the mixture. A solution of an acrylic polymer having a weight average molecular weight (Mw) of 1.65 million and Mw / Mn = 3.7 was prepared by carrying out a polymerization reaction for 4 hours while maintaining the liquid temperature in the flask at around 55 ° C.

Next, 0.3 parts of dibenzoyl sulphonyl (Nippon Yushi Co., Ltd .: Niper BMT) and 0.1 parts of trimethylolpropanexylene diisulfate (Mitsui Takeda Chemical Co., Ltd.) per 100 parts of the solid content of this acrylic polymer solution. Co., Ltd .): Takenate D110N), 5 parts of bis (trifluoromethanesulfonyl) imidelithium (LiTFSI, manufactured by Mitsubishi Materials Co., Ltd.), and 0.2 parts of silane coupling agent (manufactured by Ryokuken Kagaku Co., Ltd .: A-100, The pressure-sensitive adhesive composition was prepared by blending an acetoacetyl group-containing silane coupling agent).

Next, the obtained solution was applied to one side of a separator (MRF38 manufactured by Mitsubishi Chemical Polyester Film Corporation). The separator was a polyethylene terephthalate film treated with a silicone-based release agent. The obtained coating film was dried at 155 ° C. for 1 minute to form an adhesive layer B on the surface of the separator. The thickness of the pressure-sensitive adhesive layer was 20 μm.

(Creation of adhesive layer C)
In the preparation of the pressure-sensitive adhesive layer A, except that the composition of the acrylic polymer was 60.9 parts of butyl acrylate, 18 parts of benzyl acrylate, 20 parts of methoxyethyl acrylate, 1 part of acrylic acid, and 0.1 part of 4-hydroxybutyl acrylate. In the same manner, the pressure-sensitive adhesive layer C was prepared. The weight average molecular weight (Mw) of the acrylic polymer was 1.6 million and Mw / Mn = 3.8.

(Creation of adhesive layer D)
In the preparation of the pressure-sensitive adhesive layer A, except that the composition of the acrylic polymer was 74.9 parts of butyl acrylate, 18 parts of benzyl acrylate, 6 parts of methoxyethyl acrylate, 1 part of acrylic acid, and 0.1 part of 4-hydroxybutyl acrylate. In the same manner, the pressure-sensitive adhesive layer D was prepared. The weight average molecular weight (Mw) of the acrylic polymer was 1.7 million and Mw / Mn = 3.8.

(Creation of adhesive layer E)
In the preparation of the pressure-sensitive adhesive layer A, the composition of the acrylic polymer was 79.5 parts of butyl acrylate, 18 parts of benzyl acrylate, 1 part of N-vinylpyrrolidone, 1 part of acrylic acid, and 0.5 part of 4-hydroxybutyl acrylate. The pressure-sensitive adhesive layer E was prepared in the same manner except that the amount of bis (trifluoromethanesulfonyl) imidelithium (LiTFSI, manufactured by Mitsubishi Materials Co., Ltd.) was 0.5 parts at the time of adjusting the pressure-sensitive adhesive composition. The weight average molecular weight (Mw) of the acrylic polymer was 1.8 million and Mw / Mn = 4.0.

(Creation of adhesive layer F)
In the preparation of the pressure-sensitive adhesive layer A, the pressure-sensitive adhesive F was prepared in the same manner except that the acrylic polymer was polymerized in the following procedure.
70 parts by weight of methoxyethyl acrylate, 29 parts by weight of butyl acrylate, 1.0 part of 4-hydroxybutyl acrylate, and 2, in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube and a cooler. 0.05 parts of 2'-azobisisobutyronitrile was charged together with 120 parts of ethyl acetate. Nitrogen gas was introduced into the flask and replaced with nitrogen while gently stirring the mixture. After the polymerization reaction was carried out for 3 hours while maintaining the liquid temperature in the flask at around 65 ° C., the liquid temperature was raised to around 75 ° C. and further reacted for 1 hour to obtain a weight average molecular weight (Mw) of 1.66 million. A solution of an acrylic polymer with Mw / Mn = 4.2 was prepared.

[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 / m ² ), and this 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"). An aqueous solution containing potassium iodide so as to be 13 parts by weight based on PVA 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 cycloolefin-based film (manufactured by Nippon Zeon Co., Ltd., ZT12, 18 μm) was bonded to the surface of the obtained polarizing film opposite to the resin substrate via an ultraviolet curable adhesive as a polarizing film protective film. Specifically, the curable adhesive described below was coated so that the total thickness was 1.0 μm, and the adhesives were joined using a roll machine. Then, a UV ray was irradiated from the cycloolefin film side to cure the adhesive. Next, the resin base material was peeled off to obtain a cycloolefin-based polarizing film protective film and a polarizing film laminate containing the polarizing film.
The details of the 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.

(Removal of polarizing film)
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.

(Creation of polarizing film laminate with adhesive layer)
By transferring the pressure-sensitive adhesive layer A to the surface of the polarizing film of the polarizing film laminate, the polarizing film laminate with the pressure-sensitive adhesive layer of Example 1 was produced.

[Example 2]
In the production of the polarizing film of Example 1, in the dyeing treatment, the concentration of the aqueous iodine solution and the immersion time were adjusted to change the iodine concentration, and the thickness of the polarizing film protective film was adjusted to obtain the polarizing film laminate. The amount of water was changed. Other conditions are the same as in Example 1.

[Example 3]
In the production of the polarizing film of Example 1, in the dyeing treatment, the concentration of the aqueous iodine solution and the immersion time were adjusted to change the iodine concentration, and the thickness of the polarizing film protective film was adjusted to obtain the polarizing film laminate. The amount of water was changed. Further, in producing the polarizing film laminate of Example 1, a cycloolefin-based film (ZF12, 13 μm, manufactured by Nippon Zeon Corporation) was bonded as a polarizing film protective film. Other conditions are the same as in Example 1.

[Example 4]
In producing the polarizing film laminate of Example 1, a triacetyl cellulose film-based film (TJ40UL manufactured by Fuji Film Co., Ltd., thickness 40 μm) was bonded as a polarizing film protective film. Further, in the preparation of the polarizing film of Example 1, the iodine concentration was changed by adjusting the concentration of the iodine aqueous solution and the immersion time in the dyeing treatment. Other conditions are the same as in Example 1.

[Example 5]
In producing the polarizing film laminate of Example 1, a transparent protective film (manufactured by Nitto Denko Co., Ltd.) having a thickness of 40 μm made of a modified acrylic polymer having a lactone ring structure was bonded as a polarizing film protective film. Further, in the preparation of the polarizing film of Example 1, the iodine concentration was changed by adjusting the concentration of the iodine aqueous solution and the immersion time in the dyeing treatment. Other conditions are the same as in Example 1.

[Example 6]
(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, 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 12.0 μm polarizing film.

(Creation of polarizing film laminate)
An aqueous solution containing a polyvinyl alcohol resin containing an acetoacetyl group (average degree of polymerization 1200, saponification degree 98.5 mol%, acetoacetylation degree 5 mol%) and methylol melamine at a weight ratio of 3: 1 as an adhesive. Was used. Using this adhesive, a transparent protective film (manufactured by Nitto Denko Co., Ltd.) with a thickness of 20 μm made of a modified acrylic polymer having a lactone ring structure is applied to one surface of the polarizing film under a temperature condition of 30 ° C. A 27 μm-thick transparent protective film having a 2 μm-thick hard coat layer (HC) formed on a 25 μm-thick triacetyl cellulose film (manufactured by Konica Minolta, trade name “KC2UA”) is bonded to the surface by a roll bonding machine. Subsequently, the mixture was heated and dried at 70 ° C. for 5 minutes in an oven to obtain a polarizing film laminate in which transparent protective films were bonded to both sides of the polarizing film.
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 2 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 / cm 2 with a high-pressure mercury lamp to cure the coating film.}
(Removal of polarizing film)
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.

(Creation of polarizing film laminate with adhesive layer)
By transferring the pressure-sensitive adhesive layer A to the surface of the acrylic transparent protective film of the polarizing film laminate, the polarizing film laminate with the pressure-sensitive adhesive layer of Example 6 was produced.

[Example 7]
In the preparation of the polarizing film of Example 6, the iodine concentration was changed by adjusting the concentration of the iodine aqueous solution and the immersion time in the dyeing treatment. Further, in the production of the polarizing film laminate of Example 6, a transparent protective film having a thickness of 30 μm made of a modified acrylic polymer having a lactone ring structure as a polarizing film protective film on one surface of the obtained polarizing film (Nitto). A transparent protective film having a thickness of 49 μm formed with a triacetyl cellulose film having a thickness of 40 μm (manufactured by Konica Minolta, trade name “KC4UY”) having a thickness of 9 μm was bonded to the other surface. Other conditions are the same as in Example 6.

[Example 8]
In Example 7, a polarizing film laminate with an adhesive layer was prepared in the same manner except that the pressure-sensitive adhesive layer C was transferred to the surface of the acrylic transparent protective film of the polarizing film laminate.

[Example 9]
In the preparation of the polarizing film of Example 6, in the stretching treatment, a PVA film having a thickness of 45 μm was stretched and conveyed to obtain a polarizing film having a thickness of 18.0 μm, and in the dyeing treatment, the concentration of the iodine aqueous solution and the immersion time were adjusted. The iodine concentration was changed. Further, in the production of the polarizing film laminate of Example 6, a transparent protective film having a thickness of 30 μm made of a modified acrylic polymer having a lactone ring structure as a polarizing film protective film on one surface of the obtained polarizing film (Nitto). A triacetyl cellulose film-based film (TJ40UL manufactured by Fuji Film Co., Ltd., thickness 40 μm) was bonded to the other surface of the film manufactured by Denko Co., Ltd. Other conditions are the same as in Example 6.

[Example 10] to [Example 13]
In the preparation of the polarizing film of Example 9, in the dyeing treatment, the concentration of the aqueous iodine solution and the immersion time were adjusted to change the iodine concentration, and the thickness of the polarizing film protective film was adjusted to obtain the polarizing film laminate. The amount of water was changed. Other conditions are the same as in Example 9.

[Example 14]
In Example 9, a polarizing film laminate with an adhesive layer was prepared in the same manner except that the pressure-sensitive adhesive layer C was transferred to the surface of the acrylic transparent protective film of the polarizing film laminate.

[Example 15]
In Example 9, a polarizing film laminate with an adhesive layer was prepared in the same manner except that the pressure-sensitive adhesive layer D was transferred to the surface of the acrylic transparent protective film of the polarizing film laminate.

[Example 16]
In Example 9, a polarizing film laminate with an adhesive layer was prepared in the same manner except that the pressure-sensitive adhesive layer E was transferred to the surface of the acrylic transparent protective film of the polarizing film laminate.

[Example 17]
(Preparation of material for forming conductive layer)
Solution containing 10 to 50% by weight of thiophene polymer (trade name: Denatron P-580W, manufactured by Nagase ChemteX Corporation) 8.6 parts, solution containing oxazoline group-containing acrylic polymer (trade name: Epocross) WS-700, manufactured by Nippon Catalyst Co., Ltd.) and 90.4 parts of water were mixed to prepare a coating solution for forming a conductive layer having a solid content concentration of 0.5% by weight. The obtained coating liquid for forming a conductive layer contained 0.04% by weight of a polythiophene-based polymer and 0.25% by weight of an oxazoline group-containing acrylic polymer.
(Preparation of polarizing film laminate with conductive layer)
The coating liquid for forming a conductive layer is applied to the acrylic film side of the polarizing film laminate of Example 9 so that the thickness after drying is 0.06 μm, and dried at 80 ° C. for 2 minutes to form a conductive layer. did. The obtained conductive layer contained 8% by weight and 50% by weight, respectively, of a thiophene-based polymer and an oxazoline group-containing acrylic polymer.
(Creation of polarizing film laminate with adhesive layer)
By transferring the pressure-sensitive adhesive layer E to the surface of the polarizing film laminate on which the conductive layer was formed, the polarizing film laminate with the pressure-sensitive adhesive layer of Example 17 was produced.

[Comparative Example 1] to [Comparative Example 2]
In the production of the polarizing film of Example 1, in the dyeing treatment, the concentration of the aqueous iodine solution and the immersion time were adjusted to change the iodine concentration, and the thickness of the polarizing film protective film was adjusted to obtain the polarizing film laminate. The amount of water was changed.
Further, the pressure-sensitive adhesive layer B was transferred to the surface of the polarizing film of the polarizing film laminate to prepare the polarizing film laminates with the pressure-sensitive adhesive layers of Comparative Examples 1 and 2. Other conditions are the same as in Example 1.

[Comparative Example 3] to [Comparative Example 4]
In the production of the polarizing film of Example 6, in the dyeing treatment, the concentration of the aqueous iodine solution and the immersion time were adjusted to change the iodine concentration, and the thickness of the polarizing film protective film was adjusted to obtain the polarizing film laminate. The amount of water was changed.
Further, the pressure-sensitive adhesive layer B was transferred to the surface of the acrylic transparent protective film of the polarizing film laminate to prepare the polarizing film laminates with the pressure-sensitive adhesive layers of Comparative Examples 3 and 4. Other conditions are the same as in Example 6.

[Comparative Example 5]
In the production of the polarizing film of Example 7, in the dyeing treatment, the concentration of the aqueous iodine solution and the immersion time were adjusted to change the iodine concentration, and the thickness of the polarizing film protective film was adjusted to obtain the polarizing film laminate. The amount of water was changed.
Further, the pressure-sensitive adhesive layer B was transferred to the surface of the acrylic transparent protective film of the polarizing film laminate to prepare the polarizing film laminate with the pressure-sensitive adhesive layer of Comparative Example 5. Other conditions are the same as in Example 7.

[Comparative Example 6]
In the preparation of the polarizing film of Example 9, in the dyeing treatment, the concentration of the aqueous iodine solution and the immersion time were adjusted to change the iodine concentration, and the thickness of the polarizing film protective film was adjusted to obtain the polarizing film laminate. The amount of water was changed.
Further, the pressure-sensitive adhesive layer B was transferred to the surface of the acrylic transparent protective film of the polarizing film laminate to prepare the polarizing film laminate with the pressure-sensitive adhesive layer of Comparative Example 6. Other conditions are the same as in Example 9.

[Comparative Example 7]
(Creation of polarizing film)
In the stretching treatment of the polarizing film of Example 9, a PVA film having a thickness of 60 μm was stretched and conveyed to obtain a polarizing film having a thickness of 22.0 μm. Further, in the dyeing treatment, the concentration of the iodine aqueous solution and the immersion time were adjusted to change the iodine concentration, and the thickness of the polarizing film protective film was adjusted to change the water content of the polarizing film laminate. Other conditions are the same as in Example 9.
(Creation of polarizing film laminate)
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 obtained polarizing film as a polarizing film protective film, and a thickness of 40 μm was applied to the other surface. A transparent protective film having a thickness of 49 μm formed with HC having a thickness of 9 μm was bonded to a triacetyl cellulose film (manufactured by Konica Minolta, trade name “KC4UY”). Other processing is the same as in Example 9.
(Removal of polarizing film)
The conditions for taking out are the same as in Example 9.
(Creation of polarizing film laminate with adhesive layer)
By transferring the pressure-sensitive adhesive layer B to the surface of the acrylic transparent protective film of the polarizing film laminate, the polarizing film laminate with the pressure-sensitive adhesive layer of Comparative Example 7 was produced.

[Comparative Example 8]
In the preparation of the polarizing film of Comparative Example 7, in the dyeing treatment, the concentration of the aqueous iodine solution and the immersion time were adjusted to change the iodine concentration, and the thickness of the polarizing film protective film was adjusted to adjust the thickness of the polarizing film protective film. The amount of water was changed. Further, a transparent protective film (manufactured by Nitto Denko Co., Ltd.) having a thickness of 20 μm made of a modified acrylic polymer having a lactone ring structure was bonded to one surface of the polarizing film as a polarizing film protective film. Other conditions are the same as in Comparative Example 7.

[Comparative Example 9]
In the stretching treatment of the polarizing film of Example 9, 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 concentration of the iodine aqueous solution and the immersion time were adjusted to change the iodine concentration, and the thickness of the polarizing film protective film was adjusted to change the water content of the polarizing film laminate.
Further, the pressure-sensitive adhesive layer B was transferred to the surface of the acrylic transparent protective film of the polarizing film laminate to prepare the polarizing film laminate with the pressure-sensitive adhesive layer of Comparative Example 9. Other conditions are the same as in Example 9.

[Comparative Example 10]
In Comparative Example 9, the polarizing film laminate with the pressure-sensitive adhesive layer of Comparative Example 10 was prepared in the same manner except that the pressure-sensitive adhesive layer C was transferred to the surface of the acrylic transparent protective film of the polarizing film laminate.

[Comparative Example 11]
In Comparative Example 6, the polarizing film laminate with the pressure-sensitive adhesive layer of Comparative Example 11 was prepared in the same manner except that the pressure-sensitive adhesive layer F was transferred to the surface of the acrylic transparent protective film of the polarizing film laminate.

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

adhesives

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

As the pressure-sensitive adhesive, CS9868US (manufactured by Nitto Denko KK) with a thickness of 200 μm was used on the surface of the polarizing film laminate on which the pressure-sensitive adhesive layers A to D were not provided.

The sample was left at 95 ° C. for 250 hours (95 ° C./250H) to evaluate color loss and redness due to heating, and after being left at 95 ° C. for 500 hours (95 ° C./500H), polyene formation was 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 heating test at 95 ° C./500H, and the amount of change ΔTs in the single transmittance was calculated by the following formula.
(Equation) ΔTs = Ts ₅₀₀ −Ts ₀
Here, Ts ₀ is the simple substance transmittance of the sample before heating, and Ts ₅₀₀ is the simple substance transmittance after heating at 95 ° C./500 H.
A negative value of the amount of change ΔTs was evaluated as “polyene formation (decrease in simple substance transmittance)” of the sample. In other words, when the simple substance transmittance after heating at 95 ° C./500 hours was the same as or larger than the simple substance transmittance before heating, it was evaluated that the problem of polyene formation did not exist.
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 heating test at 95 ° C./250H, the samples were placed on the cross Nicol and the orthogonal transmittances (%) at wavelengths of 410 nm and 700 nm were measured by the spectrophotometers, and the respective changes were ΔHs ₄₁₀ and ΔHs _700. Asked.
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 by heat treatment at 95 ° C./500 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 change amount of the orthogonal transmittance at a wavelength of 410 nm by heat treatment at 95 ° C./500 hours is 1% or more and the wavelength is 700 nm. When the amount of change in the orthogonal transmittance in was less than 5%, it was evaluated that the problem of heating reddening did not exist.

The following evaluation was performed on the polarizing film with an adhesive layer obtained in the above Examples and Comparative Examples. The evaluation results are shown in Table 1. In each evaluation, immediately after the polarizing film with the pressure-sensitive adhesive layer was produced in the "initial stage", the obtained polarizing film with the pressure-sensitive adhesive layer was placed in the humidified environment at 60 ° C./95% RH for 250 hours "after humidification". It is a value measured for each after being charged and further dried at 40 ° C. for 1 hour.

<Initial surface resistance value (Ω / □)>
After peeling the separator film from the polarizing film laminate with the pressure-sensitive adhesive layer, the surface resistance value on the surface of the pressure-sensitive adhesive layer was measured. The measurement was performed using MCP-HT450 manufactured by Mitsubishi Chemical Analytech Co., Ltd. under the conditions of an applied voltage of 250 V and an applied time of 10 seconds.

<Surface resistance value after reliability test (Ω / □)>
The polarizing film laminate with the pressure-sensitive adhesive layer was placed in a humidified environment at 60 ° C./95% RH for 500 hours, further dried at 40 ° C. for 1 hour, and then the separator film was peeled off to determine the surface resistance value of the surface of the pressure-sensitive adhesive layer. It was measured. The measurement was performed using MCP-HT450 manufactured by Mitsubishi Chemical Analytech Co., Ltd. under the conditions of an applied voltage of 250 V and an applied time of 10 seconds.
The fluctuation ratio (b / a) in Table 1 is a value calculated from the "initial" surface resistance value (a) and the "after reliability test" surface resistance value (b) (second decimal place). Rounded value).

The evaluation results in each Example and Comparative Example are shown in Table 2 below.

5. Summary of Evaluation Results FIG. 8 is a plot of the results of Examples and Comparative Examples (excluding Comparative Example 11) in an xy orthogonal coordinate system. 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, transition regions (Comparative Examples 13 and 15) between them were also found between the color loss and the polyene formation.
On the other hand, when the iodine concentration and the water content are within the predetermined regions, it can be seen that all of the heating redness, polyene formation, and color loss can be comprehensively solved. For example, all the results of the examples are around the plot showing the results of Example 3 having the smallest water content, i.e. iodine concentration 7.0 wt. % And a water content 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 9 having the smallest iodine concentration, that is, the iodine concentration of 2.2 wt. % And the partition line "α" passing through the coordinate point of 3.2 g / m ² (hereinafter referred to as the second coordinate point), that is, the upper side of y = (1043-125x) / 240 and the most. Around the plot showing the results of Example 8 with a large amount of water, i.e. iodine concentration 3.0 wt. % And a coordinate point of 4.0 g / m ² (hereinafter referred to as the fourth coordinate point) and the periphery of the plot showing the result of Example 2 having the largest iodine concentration, that is, the iodine concentration of 10.0 wt. It is positioned below the partition line "β" passing through the coordinate point of% and the water content of 0.7 g / m ² (hereinafter, the fifth coordinate point), that is, y = (379-33x) / 70. Therefore, the region partitioned by these partition lines "α" and "β" can be regarded as a line showing the requirements necessary for comprehensively solving all of heating redness, polyene formation, and color loss. .. It should be noted that these partition lines "α" and "β" are applied to all polarizing films having a film thickness of about 4 to 20 μm, regardless of the film thickness of the polarizing film. ..
Further, in Comparative Example 6 in which the pressure-sensitive adhesive B (which does not contain the polar group-containing monomer) was used, the surface resistance value was significantly increased, while the pressure-sensitive adhesive was used as the pressure-sensitive adhesive F (70% by weight of the polar group-containing monomer). In Comparative Example 11 changed to (including), it was confirmed that the resistance value did not change because the bleeding of the ionic compound could be prevented, but polyene formation would occur. From this, it is presumed that if a polar group-containing monomer is used in excess of a predetermined amount in the monomer component of the pressure-sensitive adhesive polymer, polyene formation is promoted.

(2) Further, from the results of plotting and common general knowledge, in particular, for all polarizing films having a film thickness of about 4 to 20 μm, the iodine concentration and the water content of the polarizing film laminate are surrounded by a to e. More specifically, the iodine concentration is 7.0 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 2.2 wt.} The first line segment connecting the second coordinate point (“b” in the figure) of% and the water content of 3.2 g / m ^{2, the second coordinate point “b”, and the iodine concentration of 2.2 wt.} The second line segment connecting the third coordinate point (“c” in the figure) of% and the water content of 4.0 g / m ^{2, the third coordinate point “c”, and the iodine concentration of 3.0 wt.} The third line segment connecting the fourth coordinate point (“d” in the figure) of% and the water content of 4.0 g / m ^{2, the fourth coordinate point “d”, and the iodine concentration 10.0 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 20 μm, the region in which the iodine concentration and the water content of the polarizing film laminate are surrounded by f, b, c, d, and g, further details. The iodine concentration is 4.5 wt. A sixth line segment connecting the sixth coordinate point (“f” in the figure) with a% and water content of 2.0 g / m ² and the second coordinate point “b”, the second coordinate point “b” and the third. 2. The second line segment connecting the coordinate point "c", the third line segment connecting the third coordinate point "c" and the fourth coordinate point "d", the fourth coordinate point "d" and the iodine concentration 4. 5 wt. % And the 7th line segment connecting the 7th coordinate point (“g” in the figure) of 3.3 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 2.3 g / m ^{2, which is} the coordinate point “f-1”, and the seventh coordinate point “g” is the iodine concentration of 4.0 wt. It is considered that a preferable result can be obtained when the coordinate point “g-1” has% and a water content of 3.5 g / m ^2.
For a polarizing film having a film thickness of about 11 to 20 μm, the iodine concentration and the water content of the polarizing film laminate are surrounded by f, b, c, d, and g, and a line connecting h and i. Regions partitioned by line segments, more specifically iodine concentration 3.3 wt. The ninth line segment connecting the eighth coordinate point (“h” in the figure) and the second coordinate point “b” with% and water content of 2.6 g / m ^{2, the second coordinate point “b” and the third.} The second line segment connecting the coordinate point "c", the third line segment connecting the third coordinate point "c" and the fourth coordinate point "d", the fourth coordinate point "d" and the seventh coordinate point. 6. The seventh line segment connecting "g", the eighth line segment connecting the sixth coordinate point "f" and the seventh coordinate point "g", the eighth coordinate point "h", and the iodine concentration 6. 0 wt. % And a water content of 2.6 g / m ² when it is contained in the area surrounded by the tenth line segment connecting the ninth coordinate point (“i” in the figure), “polyene formation” and “color loss”. It is presumed that better results will be obtained in all of "heated reddening".

(4) Further, for a polarizing film having a film thickness of about 4 to 11 μm, preferably a film thickness of 4 to 7 μm, more preferably a film thickness of 4.5 to 6 μm, the iodine concentration and the lamination of the polarizing film The region where the water content of the body is surrounded by a, h, i, and e, and more specifically, the eleventh line segment and the eighth coordinate connecting the first coordinate point "a" and the eighth coordinate point "h". A tenth line segment connecting the point "h" and the ninth coordinate point "i", a twelfth line segment connecting the ninth coordinate point "i" and the fifth coordinate point "e", and a first coordinate point. Includes all of "polyenization", "color loss", and "heating reddening" when included in the area surrounded by the fifth line segment connecting "a" and the fifth coordinate point "e". It turns out that it can be solved.
In particular, the 8th coordinate point "h" is the 6th coordinate point "f", and the 9th coordinate point "i" is the iodine concentration of 7.2 wt. It is considered that a preferable result can be obtained when it is the tenth coordinate point (“j” in the figure) of% and the water content of 2.0 g / m ^2.
Further, for a polarizing film having a film thickness of about 4 to 11 μm, preferably a film thickness of 4 to 7 μm, more preferably a film thickness of 4.5 to 6 μm, the iodine concentration and the water content of the polarizing film laminate However, the region surrounded by a, k, i, and e, more specifically, the first coordinate point “a” and the iodine concentration of 6.0 wt. The thirteenth line segment connecting the eleventh coordinate point (“k” in the figure) of% and the water content of 1.2 g / m ^{2, connecting the eleventh coordinate point “k” and the ninth coordinate point “i”.} The 14th line segment, the 12th line segment connecting the 9th coordinate point "i" and the 5th coordinate point "e", and the 12th line segment connecting the 1st coordinate point "a" and the 5th coordinate point "e". It is presumed that better results can be obtained in all of "polyenization", "color loss", and "heating reddening" when they are included in the region surrounded by the line segment 5. In particular, the eleventh coordinate point "k" has an iodine concentration of 6.5 wt. % And a coordinate point (k-1) having a water content of 1.0 g / m ² , and the ninth coordinate point “i” has an iodine concentration of 6.5 wt. It is considered that more preferable results can be obtained when the coordinate point (i-1) is% and the water content is 2.3 g / m ^2.

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 122 Polarizing film

protective film

20, 24 First,

second polarization Films

21, 22 First and second adhesive layers 23 Liquid crystal layer 25 Touch sensor unit 26 Drive electrode and sensor unit 27

Drive electrodes

41, 42 First and second transparent substrates C Liquid crystal cell

Claims

A polarizing film with an adhesive layer, comprising a polarizing film containing a polyvinyl alcohol-based resin and an adhesive layer provided on at least one surface of the polarizing film directly or via an optically transparent polarizing film protective film. It is a laminated body
The pressure-sensitive adhesive layer contains a pressure-sensitive adhesive polymer and an ionic compound, and the pressure-sensitive adhesive polymer contains 0.1 to 30% by weight of a polar group-containing monomer as a monomer unit in all the monomer components constituting the pressure-sensitive adhesive polymer. There,
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 / m 2) of the polarizing film laminate is on the y-axis.
Iodine concentration 7.0 wt. % And the first coordinate point with a water content of 0.7 g / m 2 and an iodine concentration of 2.2 wt. % And the first line segment connecting the second coordinate point with a water content of 3.2 g / m 2.
The second coordinate point and the iodine concentration of 2.2 wt. % And a second line segment connecting the third coordinate point with a water content of 4.0 g / m 2.
The third coordinate point and the iodine concentration of 3.0 wt. % And a third line segment connecting the fourth coordinate point with a water content of 4.0 g / m 2.
The fourth coordinate point and the iodine concentration of 10.0 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. A polarizing film laminate having an iodine concentration and a water content contained therein.
The polarizing film laminate according to claim 1, wherein the polar group-containing monomer is an amide group-containing monomer and / or an alkoxyalkyl group-containing monomer.
The polarizing film laminate according to claim 1 or 2, wherein the ionic compound is an alkali metal salt and / or an organic cation-anionic salt.
The polarizing film laminate according to any one of claims 1 to 3, wherein the pressure-sensitive adhesive layer is provided on the polarizing film or the polarizing film protective film via a conductive layer.
The polarizing film laminate according to any one of claims 1 to 4, wherein the polarizing film has a film thickness of 4 to 20 μm.
Lamination of a polarizing film with an adhesive layer, comprising a polarizing film containing a polyvinyl alcohol-based resin and an adhesive layer provided on at least one surface of the polarizing film directly or via an optically transparent polarizing film protective film. The body
The pressure-sensitive adhesive layer contains a pressure-sensitive adhesive polymer and an ionic compound, and the pressure-sensitive adhesive polymer contains 0.1 to 30% by weight of a polar group-containing monomer as a monomer unit in all the monomer components constituting the pressure-sensitive adhesive polymer. There,
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 / m 2) of the polarizing film laminate is on the y-axis.
Iodine concentration 4.5 wt. The sixth coordinate point of% and water content of 2.0 g / m 2 and the iodine concentration of 2.2 wt. % And a sixth line segment connecting the second coordinate point with a water content of 3.2 g / m 2.
The second coordinate point and the iodine concentration of 2.2 wt. % And a second line segment connecting the third coordinate point with a water content of 4.0 g / m 2.
The third coordinate point and the iodine concentration of 3.0 wt. % And a third line segment connecting the fourth coordinate point with a water content of 4.0 g / m 2.
The fourth coordinate point and the 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 3.3 g / m 2 and the 8th line segment connecting the 6th coordinate point and the 7th coordinate point. A polarizing film laminate having an iodine concentration and a water content contained therein.
The sixth coordinate point has an iodine concentration of 4.0 wt. % And a coordinate point having a water content of 2.3 g / m 2 , and the seventh coordinate point has an iodine concentration of 4.0 wt. The polarizing film laminate according to claim 6, which is a coordinate point of% and a water content of 3.5 g / m 2.
The polarizing film laminate according to claim 6 or 7, wherein the polarizing film has a film thickness of 11 to 20 μm.
Lamination of a polarizing film with an adhesive layer, comprising a polarizing film containing a polyvinyl alcohol-based resin and an adhesive layer provided on at least one surface of the polarizing film directly or via an optically transparent polarizing film protective film. The body
The pressure-sensitive adhesive layer contains a pressure-sensitive adhesive polymer and an ionic compound, and the pressure-sensitive adhesive polymer contains 0.1 to 30% by weight of a polar group-containing monomer as a monomer unit in all the monomer components constituting the pressure-sensitive adhesive polymer. There,
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 / m 2) of the polarizing film laminate is on the y-axis.
Iodine concentration 7.0 wt. % And the first coordinate point with a water content of 0.7 g / m 2 and an iodine concentration of 3.3 wt. % And the eleventh line segment connecting the eighth coordinate point of 2.6 g / m 2
The eighth coordinate point and the iodine concentration of 6.0 wt. % And the tenth line segment connecting the ninth coordinate point of 2.6 g / m 2
The 9th coordinate point and the iodine concentration 10.0 wt. In the area surrounded by the twelfth 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. A polarizing film laminate having an iodine concentration and a water content contained therein.
The eighth coordinate point has an iodine concentration of 4.5 wt. % And the sixth coordinate point having a water content of 2.0 g / m 2 , and the ninth coordinate point has an iodine concentration of 7.2 wt. The polarizing film laminate according to claim 9, which is the tenth coordinate point of% and a water content of 2.0 g / m 2.
The polarizing film laminate according to claim 9 or 10, 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 11, wherein the polarizing film contains zinc.
After heating at 95 ° C./500 hours 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. The polarizing film laminate according to any one of claims 1 to 12, wherein the single transmittance of the above is the same as or larger than the single transmittance before heating.
A heat treatment at 95 ° C./500 hours for 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 with an adhesive. The polarizing film laminate according to any one of claims 1 to 13, wherein the amount of change in the orthogonal transmittance at a wavelength of 410 nm is less than 1%, and the amount of change in the orthogonal transmittance at a wavelength of 700 nm is less than 5%. body.
A heat treatment at 95 ° C./500 hours for 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 with an adhesive. The polarizing film laminate according to any one of claims 1 to 13, wherein the amount of change in the orthogonal transmittance at a wavelength of 410 nm is 1% or more, and the amount of change in the orthogonal transmittance at a wavelength of 700 nm is less than 5%. body.
Optical display cell and
The polarizing film laminate according to any one of claims 1 to 15, 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 16, wherein the optical display cell has a built-in touch sensing function.
The optical display cell contains a liquid crystal layer containing liquid crystal molecules homogenically oriented in the absence of an electric field, a first transparent substrate and a second transparent substrate sandwiching the liquid crystal layer on both sides, and the first transparent substrate and the first transparent substrate. 2. The optical display panel according to claim 16, further comprising a touch sensor and a touch sensing electrode portion related to a touch drive function between the transparent substrate and the transparent substrate.
The optical display panel according to claim 18, wherein the first transparent substrate on the visual side is not provided with a conductive layer.
The optical display panel according to claim 16, wherein the transparent cover plate has a function of a capacitive touch sensor.
The optical display panel according to claim 17, wherein an ITO layer as a component of a capacitive touch sensor is provided between the transparent cover plate and the polarizing film laminate.