JP2023050530A - Polarizing plate with adhesion suppressing layer and liquid crystal device using polarizing plate with adhesion suppressing layer - Google Patents

Abstract

To provide a liquid crystal display device in which an optical defect is suppressed while maintaining high luminance, and to provide a polarizing plate with an adhesion suppressing layer capable of achieving such a liquid crystal display device.SOLUTION: A polarizing plate with adhesion suppressing layer includes: a polarizing plate including a polarizer; and an adhesion suppressing layer arranged directly on one side of the polarizing plate or through an adhesive layer. The adhesion suppressing layer is a porous layer. A liquid crystal display device includes: a liquid crystal cell; a viewing side polarizing plate arranged on the viewing side of the liquid crystal cell; and the polarizing plate with the adhesion suppressing layer arranged on the side opposite to the viewing side of the liquid crystal cell. The polarizing plate with the adhesion suppressing layer is arranged so that the adhesion suppressing layer is opposite to the viewing side of the polarizing plate.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a polarizing plate with an adhesion-suppressing layer and a liquid crystal display device using the polarizing plate with an adhesion-suppressing layer.

2. Description of the Related Art In recent years, there has been remarkable spread of liquid crystal display devices as image display devices with low power consumption and space saving. Various optical films or optical sheets are used on the back side (backlight side) of the liquid crystal display device. Such an optical film or optical sheet typically has the function of condensing, diffusing, converging, polarizing or reflecting light by refracting, reflecting, diffracting, interfering or dispersing the light. Representative examples of such an optical film or optical sheet include a reflective polarizer (brightness enhancement film), a prism film (prism sheet), and a diffusion film (diffusion sheet).

JP-A-2012-2829

In the liquid crystal display device, the optical film or sheet as described above and the liquid crystal panel (substantially, the back side polarizing plate) are in physical contact (optically in close contact) to wet out (optically There may be optical defects such as a phenomenon where unevenness looks like wet spots), interference fringes (Newton rings), and a conspicuous light image of the backlight. SUMMARY OF THE INVENTION The present invention has been made to solve the above conventional problems, and a main object thereof is to provide a liquid crystal display device in which optical defects are suppressed while maintaining high luminance, and such a liquid crystal display device can be realized. An object of the present invention is to provide a polarizing plate with an adhesion suppression layer.

A polarizing plate with an adhesion suppression layer according to an embodiment of the present invention has a polarizing plate containing a polarizer and an adhesion suppression layer disposed on one side of the polarizing plate directly or via an adhesive layer, The adhesion suppressing layer is a porous layer.
In one embodiment, the adhesion suppression layer-attached polarizing plate is provided with another pressure-sensitive adhesive layer on the other side of the polarizing plate.
In one embodiment, the adhesion suppression layer has a water contact angle of 90° or more.
In one embodiment, the adhesion suppressing layer has a porosity of 30% by volume to 80% by volume. In one embodiment, the adhesion suppressing layer has a pore size of 2 nm to 500 nm. In one embodiment, the adhesion suppressing layer has a refractive index of 1.05 to 1.30. In one embodiment, the adhesion suppressing layer has a haze of 0.1% or more and less than 5.0%.
In one embodiment, the adhesion suppressing layer has a thickness of 0.1 μm to 100 μm.
According to another aspect of the invention, a liquid crystal display device is provided. This liquid crystal display device comprises a liquid crystal cell, a viewing side polarizing plate arranged on the viewing side of the liquid crystal cell, and the polarizing plate with an adhesion suppression layer arranged on the side opposite to the viewing side of the liquid crystal cell. have. The adhesion-suppressing layer-attached polarizing plate is arranged such that the adhesion-suppressing layer is on the opposite side of the polarizing plate to the viewing side.
In one embodiment, the liquid crystal display device has a backlight unit including a light source on the side opposite to the viewing side of the polarizing plate with the adhesion suppression layer.
In one embodiment, the liquid crystal display device has at least one optical film selected from a reflective polarizer, a diffusion film, and a prism film between the polarizing plate with an adhesion suppression layer and the backlight unit. further has
In one embodiment, in the liquid crystal display device, the optical film closest to the viewing side among the optical films is arranged with the polarizing plate with the adhesion suppression layer via an air layer. In another embodiment, the optical film closest to the viewer among the optical films is attached to the polarizing plate with the adhesion suppression layer.
A liquid crystal display device according to another embodiment of the present invention comprises a liquid crystal cell, a viewing-side polarizing plate arranged on the viewing side of the liquid crystal cell, and a back-side polarizing plate arranged on the side opposite to the viewing side of the liquid crystal cell. and a backlight unit, and at least one optical film disposed between the back-side polarizing plate and the backlight unit, wherein the optical film closest to the viewing side of the at least one optical film An adhesion suppression layer is formed on the viewing side, and the adhesion suppression layer is a porous layer.

According to the embodiments of the present invention, it is possible to obtain a liquid crystal display device in which optical defects are suppressed while maintaining high luminance, and a polarizing plate with an adhesion suppression layer capable of realizing such a liquid crystal display device.

1 is a schematic cross-sectional view of a polarizing plate with an adhesion suppression layer according to one embodiment of the present invention; FIG. 1 is a schematic cross-sectional view of a liquid crystal display device according to one embodiment of the present invention; FIG.

Although representative embodiments of the present invention will be described below, the present invention is not limited to these embodiments. The drawings are shown schematically for the sake of clarity, and the ratios of length, width, thickness, etc., and angles, etc. in the drawings are different from the actual ones.

A. Overall Configuration of Polarizing Plate with Adhesion Suppression Layer FIG. 1 is a schematic cross-sectional view of a polarizing plate with an adhesion suppression layer according to one embodiment of the present invention. A polarizing plate 100 with an adhesion suppression layer in the illustrated example has a polarizing plate 10 and an adhesion suppression layer 30 arranged on one side of the polarizing plate 10 with an adhesive layer 21 interposed therebetween. The adhesion-suppressing layer 30 may be formed directly on the polarizing plate (that is, without an adhesive layer or an adhesive layer interposed therebetween). That is, the adhesive layer 21 may be omitted. The polarizing plate 10 includes a polarizer 11, a first protective layer 12 arranged on one side of the polarizer 11, and a second protective layer 13 arranged on the other side of the polarizer 11. . Depending on the purpose, one of the first protective layer 12 and the second protective layer 13 may be omitted. The polarizing plate 100 with an adhesion suppression layer can be typically used as a rear-side polarizing plate in a liquid crystal display device. When the polarizing plate 100 with adhesion suppression layer is arranged on the back side of the liquid crystal cell, the adhesion suppression layer 30 is typically arranged on the opposite side of the polarizing plate 10 from the viewing side (liquid crystal cell side). In the polarizing plate with adhesion suppression layer 100, practically, another adhesive layer 22 is provided on the other side of the polarizing plate 10, and the polarizing plate with adhesion suppression layer 100 can be attached to the liquid crystal cell. It is It is preferable that a release liner (not shown) is temporarily adhered to the surface of another pressure-sensitive adhesive layer 22 until the polarizing plate with an adhesion suppression layer is used. By temporarily attaching the release liner, it is possible to protect the other pressure-sensitive adhesive layer and roll-form the polarizing plate with the adhesion-suppressing layer. Hereinafter, for the sake of convenience, the adhesive layer 21 may be referred to as the first adhesive layer, and the separate adhesive layer 22 may be referred to as the second adhesive layer.

In the embodiment of the invention, the adhesion suppression layer 30 is a porous layer. The adhesion suppressing layer 30 typically has a specific void (hole) structure as described later in Section C. As a result, the adhesion-preventing layer 30 can have a specific water contact angle, porosity, void size, refractive index, haze, and the like. The adhesion suppression layer 30 is typically the outermost layer on the side opposite to the viewing side of the adhesion suppression layer attached polarizing plate 100, and when the adhesion suppression layer attached polarizing plate is applied to a liquid crystal display device, the optical layer on the back side is used. Facing or adjacent to the film or optical sheet. A liquid crystal panel (substantially, It is possible to satisfactorily suppress optical adhesion (especially optical adhesion in a high-humidity environment) between the rear side polarizing plate) and the rear side optical film or optical sheet. As a result, when the polarizing plate with an adhesion suppression layer is applied to a liquid crystal display device, it is possible to realize a liquid crystal display device in which optical defects are suppressed while maintaining high luminance. Specifically, according to the embodiment of the present invention, wet-out, interference fringes (Newton rings), backlight light image, etc., especially in a high-humidity environment, are suppressed while maintaining high brightness. A liquid crystal display device can be realized. Furthermore, such a porous layer can make the above effect more remarkable than a layer having a so-called honeycomb structure or a structure similar thereto (for example, a structure in which a plurality of through holes are formed). .

The constituent elements of the polarizing plate with an adhesion suppressing layer will be described below.

B. Polarizing plate B-1. Polarizer Any appropriate polarizer can be employed as the polarizer 11 . For example, the resin film forming the polarizer may be a single-layer resin film or a laminate of two or more layers.

Specific examples of the polarizer composed of a single-layer resin film include hydrophilic polymer films such as polyvinyl alcohol (PVA) films, partially formalized PVA films, and partially saponified ethylene/vinyl acetate copolymer films. In addition, oriented polyene films such as those dyed with dichroic substances such as iodine and dichroic dyes and stretched, and dehydrated PVA and dehydrochlorinated polyvinyl chloride films. A polarizer obtained by dyeing a PVA-based film with iodine and uniaxially stretching the film is preferably used because of its excellent optical properties.

The dyeing with iodine is performed by, for example, immersing the PVA-based film in an aqueous iodine solution. The draw ratio of the uniaxial drawing is preferably 3 to 7 times. Stretching may be performed after the dyeing treatment, or may be performed while dyeing. Moreover, you may dye after extending|stretching. If necessary, the PVA-based film is subjected to swelling treatment, cross-linking treatment, washing treatment, drying treatment, and the like. For example, by immersing the PVA-based film in water and washing it with water before dyeing, not only can dirt and anti-blocking agents on the surface of the PVA-based film be washed away, but also the PVA-based film can be swollen to remove uneven dyeing. can be prevented.

Specific examples of the polarizer obtained using the laminate of two or more layers include a laminate of a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate, or a resin A polarizer obtained using a laminate of a base material and a PVA-based resin layer formed by coating on the resin base material can be mentioned. A polarizer obtained by using a laminate of a resin base material and a PVA-based resin layer formed by coating on the resin base material is obtained, for example, by applying a PVA-based resin solution to the resin base material and drying the resin base material. forming a PVA-based resin layer thereon to obtain a laminate of a resin substrate and a PVA-based resin layer; stretching and dyeing the laminate to use the PVA-based resin layer as a polarizer; obtain. In this embodiment, preferably, a polyvinyl alcohol-based resin layer containing a halide and a polyvinyl alcohol-based resin is formed on one side of the resin substrate. Stretching typically includes immersing the laminate in an aqueous boric acid solution for stretching. Furthermore, stretching may further include stretching the laminate in air at a high temperature (eg, 95° C. or higher) before stretching in an aqueous boric acid solution, if necessary. In addition, in the present embodiment, the laminate is preferably subjected to drying shrinkage treatment in which the laminate is heated while being conveyed in the longitudinal direction to shrink the laminate by 2% or more in the width direction. Typically, the manufacturing method of the present embodiment includes subjecting the laminate to an in-air auxiliary stretching treatment, a dyeing treatment, an underwater stretching treatment, and a drying shrinkage treatment in this order. By introducing auxiliary stretching, it is possible to improve the crystallinity of PVA and achieve high optical properties even when PVA is coated on a thermoplastic resin. At the same time, by increasing the orientation of PVA in advance, it is possible to prevent problems such as deterioration of orientation and dissolution of PVA when immersed in water in the subsequent dyeing process or stretching process, resulting in high optical properties. can be achieved. Furthermore, when the PVA-based resin layer is immersed in a liquid, disturbance of the orientation of the polyvinyl alcohol molecules and deterioration of the orientation can be suppressed as compared with the case where the PVA-based resin layer does not contain a halide. As a result, the optical properties of the polarizer obtained through treatment steps such as dyeing treatment and underwater stretching treatment in which the laminate is immersed in a liquid can be improved. Furthermore, the optical properties can be improved by shrinking the laminate in the width direction by drying shrinkage treatment. The obtained resin substrate/polarizer laminate may be used as it is (that is, the resin substrate may be used as a protective layer for the polarizer), and the resin substrate may be peeled off from the resin substrate/polarizer laminate. Any appropriate protective layer may be laminated according to the purpose on the peeled surface or on the surface opposite to the peeled surface. Details of the method for manufacturing such a polarizer are described in, for example, Japanese Patent Application Laid-Open No. 2012-73580 and Japanese Patent No. 6470455. These publications are incorporated herein by reference in their entirety.

The thickness of the polarizer is preferably 15 µm or less, more preferably 12 µm or less, still more preferably 10 µm or less, particularly preferably 8 µm or less, and particularly preferably 5 µm or less. A lower limit for the thickness of the polarizer can be, for example, 1 μm. If the thickness of the polarizer is within such a range, it is possible to satisfactorily suppress curling during heating, and obtain excellent durability in appearance during heating.

The polarizer preferably exhibits absorption dichroism at any wavelength of 380 nm to 780 nm. The single transmittance of the polarizer is, for example, 41.5% to 46.0%, preferably 43.0% to 46.0%, more preferably 44.5% to 46.0%. The degree of polarization of the polarizer is preferably 97.0% or higher, more preferably 99.0% or higher, still more preferably 99.9% or higher.

B-2. Protective Layers First protective layer 12 and second protective layer 13 are each formed of any suitable film that can be used as a protective layer for a polarizer. Specific examples of the material that is the main component of the film include cellulose-based resins such as triacetyl cellulose (TAC), polyester-based, polyvinyl alcohol-based, polycarbonate-based, polyamide-based, polyimide-based, polyethersulfone-based, and polysulfone-based resins. , polystyrene-based, cyclic olefin-based (for example, polynorbornene-based), polyolefin-based, (meth)acrylic-based, and acetate-based transparent resins. Thermosetting resins such as (meth)acrylic, urethane, (meth)acrylic urethane, epoxy, and silicone, or ultraviolet curable resins may also be used. In addition, for example, a glassy polymer such as a siloxane-based polymer can also be used. Further, polymer films described in JP-A-2001-343529 (WO01/37007) can also be used. Materials for this film include, for example, a resin composition containing a thermoplastic resin having a substituted or unsubstituted imide group in a side chain and a thermoplastic resin having a substituted or unsubstituted phenyl group and nitrile group in a side chain. can be used, for example, a resin composition comprising an alternating copolymer of isobutene and N-methylmaleimide and an acrylonitrile/styrene copolymer. The polymer film can be, for example, an extrudate of the resin composition. Preferably, the first protective layer 12 and the second protective layer 13 are each composed of a cellulose-based resin film, a cyclic olefin-based resin film, or a (meth)acrylic-based resin film.

The thicknesses of the first protective layer 12 and the second protective layer 13 are each typically 300 μm or less, preferably 100 μm or less, more preferably 5 μm to 80 μm, still more preferably 10 μm to 60 μm.

The first protective layer 12 and the second protective layer 13 may have the same structure or different structures.

The first protective layer 12 is preferably optically isotropic in one embodiment. As used herein, “optically isotropic” means that the in-plane retardation Re (550) is 0 nm to 10 nm and the thickness direction retardation Rth (550) is −10 nm to +10 nm. say.

C. Adhesion Suppression Layer As described above, the adhesion suppression layer is a porous layer having voids (pores) therein. The porosity of the adhesion suppression layer is preferably 30% to 80% by volume, more preferably 32% to 70% by volume, still more preferably 35% to 65% by volume, particularly preferably 40% by volume. % to 60% by volume. If the porosity is in this range, the contact area with the optical film or optical sheet on the back side of the liquid crystal display device can be reduced, so that excellent adhesion suppressing properties can be achieved. As a result, for example, wet-out can be suppressed satisfactorily. The porosity can be calculated by Lorentz-Lorenz's formula from refractive index values measured by an ellipsometer.

The adhesion-suppressing layer has a water contact angle of, for example, 90° or more, preferably 90° to 150°, still more preferably 90° to 140°, and particularly preferably 90° to 135°. If the water contact angle is in such a range, the effect of suppressing adhesion can be favorably exhibited. Furthermore, the water contact angle has the advantage of being easier to measure and control than porosity and the like. The contact angle can be measured, for example, using a "fully automatic contact angle meter DM700" manufactured by Kyowa Interface Science Co., Ltd.

The size of the voids (pores) in the adhesion suppressing layer refers to the diameter of the major axis of the diameter of the major axis and the diameter of the minor axis of the void (pore). The size of the voids (pores) is, for example, 2 nm to 500 nm, preferably 5 nm to 300 nm, more preferably 10 nm to 200 nm, still more preferably 20 nm to 100 nm. The size of the voids (pores) can be adjusted to a desired size depending on the purpose, application, and the like. The size of voids (pores) can be quantified by the BET test method. Specifically, 0.1 g of a sample (formed void layer or porous layer) was put into the capillary of a specific surface area measuring device (manufactured by Micromeritic: ASAP2020), and then dried under reduced pressure at room temperature for 24 hours. to degas the gas within the void structure. Then, by causing the sample to adsorb nitrogen gas, an adsorption isotherm is drawn to determine the pore size distribution. This allows the void size to be evaluated.

The adhesion suppressing layer preferably has a refractive index of 1.05 to 1.30, more preferably 1.08 to 1.28, still more preferably 1.10 to 1.27, and particularly preferably 1 .12 to 1.26, particularly preferably 1.14 to 1.25. If the refractive index is within this range, it is easy to achieve the desired porosity. Furthermore, if the refractive index is within such a range, good Fresnel reflection can be achieved, and good thin film interference can be achieved by a synergistic effect with the effect of controlling the thickness of the adhesion suppressing layer. can be done. As a result, good anti-reflection characteristics can be achieved, and for example, Newton rings (interference fringes) can be well suppressed. A refractive index refers to a refractive index measured at a wavelength of 550 nm unless otherwise specified.

The haze of the adhesion suppressing layer is preferably 0.1% or more and less than 5%, more preferably 0.2% or more and less than 4%, and still more preferably 0.3% or more and less than 3%. Haze can be measured, for example, by the following method. The haze is an indicator of the transparency of the adhesion suppressing layer.
The void layer or porous layer (adhesion suppressing layer) is cut into a size of 50 mm×50 mm and set in a haze meter (HM-150 manufactured by Murakami Color Research Laboratory) to measure the haze. The haze value is calculated using the following formula.
Haze (%) = [diffuse transmittance (%)/total light transmittance (%)] x 100 (%)

Any appropriate configuration can be adopted for the adhesion-suppressing layer as long as it satisfies the desired properties described above (that is, has a porous structure that can be specified by the properties described above). As the material constituting the adhesion suppression layer, for example, the materials described in WO 2004/113966, JP-A-2013-254183, and JP-A-2012-189802 can be employed. Specifically, for example, organosilicon compounds (organosilane compounds); silica-based compounds; hydrolyzable silanes, and partial hydrolysates and dehydration condensates thereof; organic polymers; silicon compounds containing silanol groups; Active silica obtained by contacting a salt with an acid or an ion exchange resin; Polymerizable monomers (e.g., (meth) acrylic monomers and styrene monomers); Curable resins (e.g., (meth) acrylic resins, fluorine containing resins, and urethane resins); and combinations thereof. The adhesion-preventing layer can be formed, for example, by coating, spraying or printing a solution or dispersion of such material.

The adhesion suppressing layer is a porous layer having voids (pores) therein, as described above. The porous layer, in one embodiment, comprises aerogels and/or particles (eg, hollow microparticles and/or porous particles). The adhesion-preventing layer may preferably be a nanoporous layer (specifically, a porous layer in which 90% or more of the micropores have a diameter within the range of 10 ⁻¹ nm to 10 ³ nm). Any appropriate particles can be adopted as the particles. The particles are typically composed of silica-based or silsesquioxane-based compounds. Particle shapes include, for example, spherical, plate-like, needle-like, string-like, and grape cluster-like shapes. Examples of string-like particles include particles in which a plurality of particles having a spherical, plate-like, or needle-like shape are linked in a beaded shape, and short fiber-like particles (for example, the particles described in JP-A-2001-188104). short fibrous particles), and combinations thereof. String-like particles may be linear or branched. Grape cluster-like particles include, for example, grape cluster-like particles obtained by aggregating a plurality of spherical, plate-like, and needle-like particles. The shape of the particles can be confirmed, for example, by observing them with a transmission electron microscope.

The adhesion-suppressing layer can be typically formed by coating, spraying or printing as described above. With such a structure, the adhesion suppressing layer can be formed much more easily than sputtering or the like, and the adverse effect on the polarizing plate is much less. Any appropriate method can be adopted for printing. Specifically, the printing method may be a plate-type printing method such as gravure printing, offset printing, or flexographic printing, or a plateless printing method such as inkjet printing, laser printing, or electrostatic printing. good. The adhesion-suppressing layer may be directly formed on the polarizing plate, or may be transferred to the polarizing plate after being formed by coating on any appropriate base material.

In one embodiment, the adhesion-suppressing layer is composed of one type or a plurality of types of structural units that form a fine void structure, and the structural units are chemically bonded to each other through catalytic action. Examples of the shape of the structural unit include particulate, fibrous, rod-like, and tabular. A structural unit may have only one shape, or may have a combination of two or more shapes. Such a void layer can be formed, for example, by chemically bonding microporous particles together in the void layer forming step. In addition, in the embodiment of the present invention, the shape of the "particle" (for example, the microporous particles) is not particularly limited, and may be, for example, spherical or other shape. Further, in the embodiment of the present invention, the microporous particles may be, for example, sol-gel beaded particles, nanoparticles (hollow nanosilica/nanoballoon particles), nanofibers, and the like. Microporous particles typically include inorganic material. Specific examples of inorganic substances include silicon (Si), magnesium (Mg), aluminum (Al), titanium (Ti), zinc (Zn), and zirconium (Zr). These may be used alone or in combination of two or more. In one embodiment, the microporous particles are, for example, silicon compound microporous particles, and the porous body is, for example, a silicone porous body. Another form of the adhesion-suppressing layer having at least a portion of the porous layer and/or the air layer is, for example, composed of fibrous substances such as nanofibers, and the fibrous substances are entangled to form voids. There is a void layer forming The method for producing such a void layer is not particularly limited, and is, for example, the same as in the case of the void layer of the porous body in which the microporous particles are chemically bonded to each other. Still another form includes a void layer using hollow nanoparticles or nanoclay, and a void layer formed using hollow nanoballoons or magnesium fluoride. The void layer may be a void layer composed of a single constituent substance, or may be a void layer composed of a plurality of constituent substances. The void layer may be composed of a single form described above, or may be composed of a plurality of forms described above.

In the present embodiment, the porous structure of the porous body may be, for example, an open cell structure with continuous pore structures. The open cell structure means that the pore structure is three-dimensionally connected, for example, in the silicone porous material described above, and can be said to be a state in which the internal voids of the pore structure are continuous. Porosity can be increased by the porous body having an open-cell structure. However, when closed-cell particles (particles having individual pore structures) such as hollow silica are used, an open-cell structure cannot be formed. On the other hand, for example, when using silica sol particles (pulverized gel-like silicon compound that forms a sol), the particles have a three-dimensional dendritic structure, so the coating film (including pulverized gel-like silicon compound) By sedimentation and deposition of the dendritic particles in the sol coating film), it is possible to easily form an open cell structure. The adhesion suppressing layer more preferably has a monolithic structure in which the open cell structure contains a plurality of pore distributions. A monolithic structure means, for example, a hierarchical structure including a structure in which nano-sized fine voids exist and an open-cell structure in which the nano-sized voids are aggregated. In the case of forming a monolithic structure, for example, it is possible to achieve both film strength and high porosity by imparting film strength with fine pores and imparting high porosity with coarse open-cell pores. Such a monolithic structure can be preferably formed by controlling the pore distribution of the void structure produced in the gel (gelled silicon compound) prior to pulverization into silica sol particles. Further, for example, when pulverizing the gelled silicon compound, a monolithic structure can be formed by controlling the particle size distribution of the silica sol particles after pulverization to a desired size.

The adhesion-suppressing layer contains, for example, pulverized gel compounds as described above, and the pulverized materials are chemically bonded to each other. The form of chemical bonding (chemical bonding) between the pulverized particles in the adhesion suppressing layer is not particularly limited, and examples thereof include cross-linking, covalent bonding, and hydrogen bonding.

The thickness of the adhesion suppressing layer can be appropriately set according to the purpose. The thickness of the adhesion suppressing layer is, for example, 0.1 μm (100 nm) to 100 μm, and can be, for example, 0.1 μm (100 nm) to 20 μm. The thickness of the adhesion suppression layer may be, for example, 100 nm to 800 nm, or may be, for example, 150 nm to 750 nm, or may be, for example, 200 nm to 700 nm, or may be, for example, may be 250 nm to 650 nm, Further, it may be, for example, 300 nm to 600 nm, or may be, for example, 350 nm to 550 nm. Further, the thickness of the adhesion suppressing layer may be, for example, 100 nm to 80 μm, may be, for example, 200 nm to 70 μm, may be, for example, be 300 nm to 60 μm, and may be, for example, may be 400 nm to 50 μm. and may be, for example, between 500 nm and 40 μm. Furthermore, the thickness of the adhesion-suppressing layer may be, for example, 10 μm to 100 μm, or may be, for example, 20 μm to 90 μm, may be, for example, be 30 μm to 80 μm, or may be, for example, be 40 μm to 70 μm. It may be, for example, 60 μm to 100 μm, or it may be, for example, 70 μm to 100 μm, or it may be, for example, 80 μm to 90 μm. The thickness of the adhesion suppressing layer may be, for example, 1 μm to 20 μm, or may be, for example, 3 μm to 15 μm, or may be, for example, 5 μm to 12 μm, or may be, for example, 7 μm to 10 μm.

Details of the specific configuration and formation method of the adhesion suppressing layer are described, for example, in International Publication No. 2019/151073. The description of the publication is incorporated herein by reference.

D. First Adhesive Layer The first adhesive layer 21 typically has hardness to the extent that the adhesive constituting the adhesive layer does not permeate into the voids of the adhesion suppressing layer under normal conditions. The storage modulus at 23° C. of the adhesive constituting the first adhesive layer is, for example, 1.0×10 ⁵ (Pa) to 1.0×10 ⁷ (Pa), preferably 1.3×10 ⁵ (Pa) to 1.0×10 ⁶ (Pa), more preferably 1.5×10 ⁵ (Pa) to 5.0×10 ⁵ (Pa). By setting the storage elastic modulus of the first pressure-sensitive adhesive layer adjacent to the adhesion-suppressing layer (porous layer) to the above range, the pressure-sensitive adhesive constituting the first pressure-sensitive adhesive layer is absorbed into the voids of the adhesion-suppressing layer. Since the penetration can be prevented, the adhesion suppressing layer can maintain the structure, properties and effects as a porous layer. The storage modulus is measured in accordance with the method described in JIS K7244-1 "Plastics - Test method for dynamic mechanical properties" under the condition of a frequency of 1 Hz and a temperature increase rate of 5 ° C./ in the range of -50 ° C. to 150 ° C. It is determined by reading the value at 23° C. when measured in minutes.

Any appropriate pressure-sensitive adhesive may be used as the pressure-sensitive adhesive constituting the first pressure-sensitive adhesive layer as long as it has the properties as described above. The adhesive typically includes an acrylic adhesive (acrylic adhesive composition). An acrylic pressure-sensitive adhesive composition typically contains a (meth)acrylic polymer as a main component (base polymer). The (meth)acrylic polymer can be contained in the PSA composition in a proportion of, for example, 50% by weight or more, preferably 70% by weight or more, more preferably 90% by weight or more, based on the solid content of the PSA composition. A (meth)acrylic polymer contains alkyl (meth)acrylate as a main component as a monomer unit. (Meth)acrylate refers to acrylate and/or methacrylate. Alkyl groups of alkyl (meth)acrylates include, for example, linear or branched alkyl groups having 1 to 18 carbon atoms. The average number of carbon atoms in the alkyl group is preferably 3-9. Monomers constituting (meth)acrylic polymers include, in addition to alkyl (meth)acrylates, carboxyl group-containing monomers, hydroxyl group-containing monomers, amide group-containing monomers, aromatic ring-containing (meth)acrylates, and heterocyclic ring-containing (meth)acrylates. Comonomers such as acrylates are included. The comonomer is preferably a hydroxyl group-containing monomer and/or a heterocycle-containing (meth)acrylate, more preferably N-acryloylmorpholine. The acrylic pressure-sensitive adhesive composition can preferably contain a silane coupling agent and/or a cross-linking agent. Silane coupling agents include, for example, epoxy group-containing silane coupling agents. Examples of cross-linking agents include isocyanate-based cross-linking agents and peroxide-based cross-linking agents. Details of such a pressure-sensitive adhesive layer or acrylic pressure-sensitive adhesive composition are described, for example, in Japanese Patent No. 4140736, and the description of the patent publication is incorporated herein by reference.

The thickness of the first adhesive layer is preferably 5 μm to 30 μm, more preferably 10 μm to 25 μm. If the thickness of the first pressure-sensitive adhesive layer is within such a range, there is an advantage that the influence of the thickness of the first pressure-sensitive adhesive layer on the overall thickness is small while maintaining sufficient adhesion.

E. Second Adhesive Layer The second adhesive layer 22 is composed of any suitable adhesive for bonding the polarizing plate to the liquid crystal cell. Specifically, the second pressure-sensitive adhesive layer can be composed of pressure-sensitive adhesives widely used in the industry. The thickness of the second adhesive layer may be, for example, 5 μm to 200 μm, or may be, for example, 10 μm to 150 μm.

F. Liquid Crystal Display Device The polarizing plate with an adhesion suppressing layer according to the above items A to E can be used as a back side polarizing plate of a liquid crystal display device. Therefore, the embodiments of the present invention also include a liquid crystal display device using such a polarizing plate with an adhesion suppression layer. FIG. 2 is a schematic cross-sectional view of a liquid crystal display according to one embodiment of the invention. The liquid crystal display device 200 of the illustrated example includes a liquid crystal cell 130, a viewing side polarizing plate 110 arranged on the viewing side of the liquid crystal cell 130, and the above items A to E arranged on the side opposite to the viewing side of the liquid crystal cell 130. and a polarizing plate 100 with an adhesion suppression layer described in . Typically, the absorption axis direction of the polarizer of the viewer-side polarizing plate 110 and the absorption axis direction of the polarizer of the polarizing plate with adhesion suppression layer 100 are substantially perpendicular to each other. The adhesion suppression layer-attached polarizing plate 100 is attached to the liquid crystal cell 130 via the second adhesive layer 22 . Therefore, the adhesion suppressing layer 30 is arranged on the side opposite to the viewing side (liquid crystal cell side) of the polarizing plate 10 .

The liquid crystal cell 130 has a viewer-side substrate 132 , a back-side substrate 131 , and a liquid crystal layer 133 sandwiched between the viewer-side substrate 132 and the back-side substrate 131 and containing liquid crystal molecules as a display medium. In a general configuration, one substrate (typically, the viewer-side substrate 132) is provided with a color filter and a black matrix, and the other substrate (typically, the rear-side substrate 131) is provided with A switching element for controlling electro-optical characteristics of liquid crystal, a signal line for applying a gate signal and a source signal to the switching element, a pixel electrode and a counter electrode are provided. The spacing (cell gap) between the substrates is controlled by a spacer or the like. An alignment film made of polyimide, for example, can be provided on the side of the substrate that is in contact with the liquid crystal layer.

The liquid crystal layer may contain liquid crystal molecules aligned in a homogeneous alignment in the absence of an electric field, or may contain liquid crystal molecules aligned in a homeotropic alignment in the absence of an electric field. "Homogeneous alignment of liquid crystal molecules" refers to a state in which the alignment vectors of liquid crystal molecules are aligned parallel to the plane of the substrate as a result of the interaction between the alignment-treated substrate and the liquid crystal molecules; The term "tropically aligned liquid crystal molecules" refers to a state in which the alignment vectors of the liquid crystal molecules are aligned perpendicular to the plane of the substrate as a result of the interaction between the liquid crystal molecules and the substrate subjected to the alignment treatment. A representative example of a driving mode using a liquid crystal layer of homogeneous alignment is an in-plane switching (IPS) mode. A typical example of a drive mode using a homeotropically aligned liquid crystal layer is a vertical alignment (VA) mode. Note that the drive mode is not limited in the embodiment of the present invention, and any appropriate drive mode can be adopted according to the purpose.

Practically, the liquid crystal display device 100 has a backlight unit 170 on the side opposite to the viewing side of the polarizing plate 100 with an adhesion suppression layer. A backlight unit includes a light source. The illustrated backlight unit 170 is of edge light type and typically includes a light source 171 and a light guide plate 172 . Any other appropriate type (for example, direct type) may be employed as the backlight unit. A direct type backlight unit (not shown) typically includes a light source arranged vertically below a liquid crystal panel (liquid crystal cell and both polarizing plates) and a diffusion film or diffusion sheet arranged above the light source. , have

In one embodiment, the liquid crystal display device 200 may further have at least one optical film between the polarizing plate 100 with an adhesion suppression layer and the backlight unit 170 . Examples of optical films include reflective polarizers (brightness enhancement films), prism films (prism sheets), and diffusion films (diffusion sheets). Each of these optical films may be used alone or in combination of two or more. For example, two prism films may be used. In the illustrated liquid crystal display device 200, for example, a reflective polarizer 140, a diffusion film 150, and a prism film 160 are arranged in this order from the polarizing plate 100 with an adhesion suppression layer. The prism film is typically arranged so that the convex portion of the unit prisms is on the polarizing plate side with the adhesion suppressing layer. The arrangement order of the optical films can be appropriately changed depending on the purpose. By using the polarizing plate with an adhesion suppression layer according to the embodiment of the present invention, wet-out, interference fringes (Newton rings), backlight light image, etc., especially in a high-humidity environment can be reduced while maintaining high brightness. A suppressed liquid crystal display device can be realized, and the functions of these optical films can be favorably maintained.

As for the optical films as described above, in one embodiment, all the optical films are incorporated into the housing of the backlight unit. In this case, the optical film closest to the viewing side among the optical films is arranged with an air layer interposed between the polarizing plate with the adhesion suppression layer. Further, in such an embodiment, typically, the respective films are not adhered to each other in the housing, but are substantially separated with an air layer interposed therebetween.

In another embodiment of the optical film, the optical film closest to the viewer is attached to the polarizing plate with the adhesion suppression layer. That is, the optical film closest to the viewer can be integrated with the polarizing plate with the adhesion suppression layer. In this case, all the remaining optical films may be successively laminated to be integrated with the polarizing plate with an adhesion suppression layer; It may be integrated with the polarizing plate with an adhesion suppression layer, and part of it may be incorporated in the housing of the backlight unit; all the remaining optical films may be incorporated in the housing of the backlight unit. Note that lamination can be performed via any appropriate adhesive layer (adhesive layer or adhesive layer).

In the embodiment of the present invention, the same effect can be obtained if the adhesion suppressing layer faces or is adjacent to the back side polarizing plate. Therefore, the adhesion suppressing layer may be formed on the viewing side of the optical film closest to the viewing side among the optical films on the backlight side, instead of being formed on the back side of the back side polarizing plate (not shown). .

EXAMPLES The present invention will be specifically described below with reference to Examples, but the present invention is not limited to these Examples. Evaluation items in the examples are as follows. "Parts" and "%" in the examples are by weight unless otherwise specified.

(1) Water contact angle of adhesion suppression layer The adhesion suppression layer formed in the example was measured using a "fully automatic contact angle meter DM700" manufactured by Kyowa Interface Science Co., Ltd.

(2) Porosity of Adhesion Suppressing Layer An adhesion suppressing layer similar to that of the example was formed on a substrate (acrylic film) to prepare a laminate. The X-ray reflectance of the total reflection region of the obtained adhesion-suppressing layer of the laminate was measured using an X-ray diffractometer (manufactured by RIGAKU, product name "RINT-2000"). Furthermore, after fitting the Intensity and 2θ, the film density (g/cm ³ ) was calculated from the total reflection critical angle of the laminate, and the porosity (%) was calculated from the following formula.
Porosity (%) = 45.48 x film density (g/cm ³ ) + 100 (%)

(3) Refractive index of adhesion suppression layer The adhesion suppression layer formed in the example was measured using an ellipsometer.

(4) Haze of adhesion suppressing layer The adhesion suppressing layer formed in Examples was measured using a haze meter.

(5) Wet-out The liquid crystal display devices obtained in Examples and Comparative Examples were placed in an oven at a temperature of 60° C. and a relative humidity of 95% for 24 hours, and after taking them out, the presence or absence of wet-out was visually observed. was evaluated according to the criteria of
○ (Good): Wet-out was not observed × (Poor): Wet-out was observed

(6) Luminance A white screen was displayed on the liquid crystal display devices obtained in Examples and Comparative Examples, and the luminance of the white screen display was measured using a luminance meter (manufactured by AUTONIC-MELCHERS, trade name "Conoscope"). It was evaluated as a ratio when the luminance of the liquid crystal display device of Comparative Example 1 was defined as "100".

[Production Example 1] Production of polarizing plate (production of polarizer)
A long amorphous isophthalic copolymerized polyethylene terephthalate film (thickness: 100 μm) having a Tg of about 75° C. was used as the thermoplastic resin substrate, and one side of the resin substrate was subjected to corona treatment.
Polyvinyl alcohol (degree of polymerization: 4,200, degree of saponification: 99.2 mol%) and acetoacetyl-modified PVA (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "GOSEFIMER") were mixed at a ratio of 9:1, and 100 parts by weight of PVA-based resin. was added with 13 parts by weight of potassium iodide and dissolved in water to prepare an aqueous PVA solution (coating solution).
The above PVA aqueous solution was applied to the corona-treated surface of the resin base material and dried at 60° C. to form a PVA-based resin layer having a thickness of 13 μm, thereby producing a laminate.
The resulting laminate was uniaxially stretched 2.4 times in the machine direction (longitudinal direction) in an oven at 130° C. (in-air auxiliary stretching treatment).
Next, the laminate was immersed in an insolubilizing bath (an aqueous boric acid solution obtained by mixing 4 parts by weight of boric acid with 100 parts by weight of water) at a liquid temperature of 40° C. for 30 seconds (insolubilizing treatment).
Then, the finally obtained polarizer is added to a dyeing bath (iodine aqueous solution obtained by blending iodine and potassium iodide at a weight ratio of 1:7 with respect to 100 parts by weight of water) at a liquid temperature of 30 ° C. It was immersed for 60 seconds while adjusting the concentration so that the single transmittance (Ts) was a desired value (dyeing treatment).
Next, it was immersed for 30 seconds in a cross-linking bath at a liquid temperature of 40°C (an aqueous solution of boric acid 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). (crosslinking treatment).
After that, while immersing the laminate in an aqueous solution of boric acid (boric acid concentration: 4% by weight, potassium iodide concentration: 5% by weight) at a liquid temperature of 70° C., the laminate was moved vertically (longitudinally) between rolls with different peripheral speeds. Uniaxial stretching was performed so that the stretching ratio was 5.5 times (underwater stretching treatment).
After that, the laminate was immersed in a washing bath (aqueous solution obtained by blending 4 parts by weight of potassium iodide with 100 parts by weight of water) at a liquid temperature of 20° C. (washing treatment).
Thereafter, while drying in an oven maintained at about 90° C., it was brought into contact with a heating roll made of SUS whose surface temperature was maintained at about 75° C. (dry shrinkage treatment).
In this manner, a polarizer having a thickness of about 5 μm was formed on the resin base material to obtain a polarizing plate having a structure of resin base material/polarizer.

(Preparation of polarizing plate)
A triacetyl cellulose (TAC) film (thickness: 25 μm) was attached to the surface of the obtained polarizer (the surface opposite to the resin substrate). Next, the resin substrate is peeled off, and an acrylic film (thickness 20 μm) is attached to the peeled surface, TAC film (outer or backlight side protective layer) / polarizer / acrylic film (inner or liquid crystal cell side protective layer). A polarizing plate P1 having the structure of was obtained.

[Production Example 2] Preparation of coating solution for forming adhesion-suppressing layer (1) Gelation of silicon compound To 2.2 g of dimethylsulfoxide (DMSO), methyltrimethoxysilane (MTMS), which is a precursor of the silicon compound, was added to 0. Mixture A was prepared by dissolving .95 g. 0.5 g of a 0.01 mol/L oxalic acid aqueous solution is added to this mixed solution A, and MTMS is hydrolyzed by stirring at room temperature for 30 minutes to generate a mixed solution B containing tris(hydroxy)methylsilane. bottom.
After adding 0.38 g of 28% by weight ammonia water and 0.2 g of pure water to 5.5 g of DMSO, the mixture B was further added and stirred at room temperature for 15 minutes to obtain Tris ( Hydroxy)methylsilane was gelled to obtain a mixed liquid C containing a gelled silicon compound.
(2) Aging Treatment Mixture C containing the gel-like silicon compound prepared as described above was incubated as it was at 40° C. for 20 hours to perform an aging treatment.
(3) Pulverization Next, the gel-like silicon compound aged as described above was pulverized into granules with a size of several mm to several cm using a spatula. Next, 40 g of isopropyl alcohol (IPA) was added to the mixed liquid C, and after lightly stirring, the mixture was allowed to stand at room temperature for 6 hours, and the solvent and catalyst in the gel were decanted. By performing the same decantation treatment three times, the solvent was replaced and a mixed liquid D was obtained. Next, the gelled silicon compound in the mixed liquid D was pulverized (high-pressure medialess pulverization). The pulverization treatment (high-pressure medialess pulverization) uses a homogenizer (manufactured by SMT Co., Ltd., trade name "UH-50"), and 1.85 g of the gel compound in the mixed liquid D and 1.85 g of IPA are added to a 5 cc screw bottle. After weighing 15 g, it was pulverized for 2 minutes under conditions of 50 W and 20 kHz.
By this pulverization treatment, the gel-like silicon compound in the mixture D was pulverized, so that the mixture D became the sol E of the pulverized product. The volume average particle diameter, which indicates the variation in particle size of the pulverized material contained in the mixed liquid E, was confirmed by a dynamic light scattering type Nanotrack particle size analyzer (manufactured by Nikkiso Co., Ltd., UPA-EX150 type), and was 0.50 to 0. .70. Furthermore, 0.062 g of a 1.5% by weight MEK (methyl ethyl ketone) solution of a photobase generator (Wako Pure Chemical Industries, Ltd.: trade name WPBG266) was added to 0.75 g of this sol liquid (mixture C′). A 5% concentration MEK solution of bis(trimethoxysilyl)ethane was added at a rate of 0.036 g to obtain a coating liquid I for forming an adhesion suppressing layer.

[Production Example 3] Preparation of coating solution for forming adhesion suppression layer Add 13 parts of water to 20 parts of alumina sol solution (4.9% concentration: manufactured by Kawaken Fine Chemicals), heat at 80 ° C., and then add ₃ parts of NH3. added. Furthermore, it heated at 80 degreeC for 10 hours, and obtained the gel-like compound. A coating solution II for forming an adhesion suppressing layer was obtained in the same manner as in Production Example 2, except that this gel compound was used in place of the gel compound in Production Example 2.

[Production Example 4] Formation of first adhesive layer In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a cooler, 90.7 parts of butyl acrylate, 6 parts of N-acryloylmorpholine, acrylic 3 parts of an acid, 0.3 parts of 2-hydroxybutyl acrylate, and 0.1 parts by weight of 2,2′-azobisisobutyronitrile as a polymerization initiator were charged together with 100 g of ethyl acetate, and nitrogen gas was introduced while gently stirring. After purging with nitrogen, the temperature of the liquid in the flask was maintained at around 55° C., and the polymerization reaction was carried out for 8 hours to prepare an acrylic polymer solution. Based on 100 parts of the solid content of the obtained acrylic polymer solution, 0.2 parts of an isocyanate cross-linking agent (Coronate L manufactured by Nippon Polyurethane Industry Co., Ltd., an adduct of tolylene diisocyanate of trimethylolpropane), benzoyl peroxide (Japan An acrylic pressure-sensitive adhesive solution was prepared by blending 0.3 parts of Nyper BMT manufactured by Yushi Co., Ltd. and 0.2 parts of γ-glycidoxypropylmethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.: KBM-403). Next, the above acrylic adhesive solution was applied to one side of a polyethylene terephthalate (PET) film (Mitsubishi Chemical Polyester Film Co., Ltd., thickness: 38 μm) that had been subjected to silicone treatment, and the adhesive layer after drying had a thickness of 20 μm. and dried at 150° C. for 3 minutes to form a pressure-sensitive adhesive layer PSA1. The storage elastic modulus of the obtained adhesive at 23° C. was 1.3×10 ⁵ (Pa).

[Production Example 5] Formation of Second Adhesive Layer 99 parts of butyl acrylate, 1 part of 4-hydroxybutyl acrylate, and 1 part of 4-hydroxybutyl acrylate were added to a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a cooler to initiate polymerization. 0.1 part of 2,2'-azobisisobutyronitrile as a reagent was charged together with 100 parts of ethyl acetate, and nitrogen gas was introduced while gently stirring to replace nitrogen gas. , the polymerization reaction was carried out for 8 hours to prepare an acrylic polymer solution. Based on 100 parts of the solid content of the obtained acrylic polymer solution, 0.1 part of an isocyanate cross-linking agent (Takenate D110N manufactured by Mitsui Takeda Chemicals, trimethylolpropane xylylene diisocyanate), benzoyl peroxide (manufactured by NOF Co., Ltd. Nyper BMT) and 0.2 parts of γ-glycidoxypropylmethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.: KBM-403) were blended to prepare a solution of an acrylic pressure-sensitive adhesive composition. Next, the solution of the acrylic pressure-sensitive adhesive composition was applied to one side of a polyethylene terephthalate film (separator film: MRF38, manufactured by Mitsubishi Chemical Polyester Film Co., Ltd.) treated with a silicone release agent, and the mixture was heated at 150°C for 3 minutes. After drying, a pressure-sensitive adhesive layer PSA2 having a thickness of 20 μm was formed on the surface of the separator film. The storage elastic modulus of the obtained adhesive at 23° C. was 8.2×10 ⁴ (Pa).

[Example 1]
The adhesion suppressing layer-forming coating solution I obtained in Production Example 2 was applied to the surface of the TAC film of the polarizing plate P1 obtained in Production Example 1. The coating film was dried at a temperature of 100° C. for 1 minute, then irradiated with ultraviolet rays at an integrated light amount of 350 mJ/cm ² , and further aged at 60° C. for 20 hours to form an adhesion suppressing layer. The adhesion-suppressing layer had a water contact angle of 130° and a porosity of 59%. Thus, a polarizing plate with an adhesion suppression layer was obtained.

A liquid crystal panel was taken out from a commercially available liquid crystal display device (manufactured by LG, product name “43UH7710”). The configuration on the viewing side of the liquid crystal panel was left as it was, and the optical film on the backlight side was removed. Next, the polarizing plate with an adhesion suppression layer obtained above is attached to the surface of the liquid crystal panel from which the optical film has been removed (backlight side surface) via the second adhesive layer PSA2 obtained in Production Example 5. Matched. On the other hand, after removing the optical film in the housing of the backlight unit taken out from the liquid crystal display device, the diffusion film and the prism film were incorporated into the housing in order from the liquid crystal panel side. The prism film was assembled in the housing so that the convex portion of the unit prism was on the diffusion film side. A liquid crystal display device was obtained by combining the backlight unit incorporating the optical film with the liquid crystal panel. The obtained liquid crystal display device was subjected to the evaluations of (5) and (6) above. Table 1 shows the results.

[Example 2]
The adhesion suppressing layer-forming coating liquid I obtained in Production Example 2 was applied to an acrylic film (substrate). Subsequent procedures were the same as in Example 1 to form an adhesion suppressing layer on the substrate. The resulting adhesion-suppressing layer was transferred onto the TAC film surface of the polarizing plate P1 obtained in Production Example 1 via the first pressure-sensitive adhesive layer PSA1 obtained in Production Example 4. Thus, a polarizing plate with an adhesion suppression layer was obtained. Subsequent procedures were carried out in the same manner as in Example 1 to obtain a liquid crystal display device. The obtained liquid crystal display device was subjected to the same evaluation as in Example 1. Table 1 shows the results.

[Example 3]
A liquid crystal display device was obtained in the same manner as in Example 1, except that a prism film was used instead of the diffusion film as the optical film of the backlight unit (that is, two prism films were used). The obtained liquid crystal display device was subjected to the same evaluation as in Example 1. Table 1 shows the results.

[Example 4]
A liquid crystal display device was obtained in the same manner as in Example 1, except that a reflective polarizer (brightness enhancement film) was used instead of the diffusion film as the optical film of the backlight unit. The obtained liquid crystal display device was subjected to the same evaluation as in Example 1. Table 1 shows the results.

[Example 5]
In the same manner as in Example 1 except that the adhesion suppression layer-forming coating solution II (Production Example 3) was used instead of the adhesion suppression layer-forming coating solution I (Production Example 2), a polarized light with an adhesion suppression layer was prepared. got a board The adhesion-suppressing layer had a water contact angle of 90° and a porosity of 40%. Subsequent procedures were carried out in the same manner as in Example 1 to obtain a liquid crystal display device. The obtained liquid crystal display device was subjected to the same evaluation as in Example 1. Table 1 shows the results.

[Example 6]
A liquid crystal display device was obtained in the same manner as in Example 1, except that instead of incorporating the diffusion film into the housing of the backlight unit, it was attached to the adhesion suppression layer of the polarizing plate with the adhesion suppression layer via an adhesive. . The prism film was incorporated in the housing of the backlight unit in the same manner as in Example 1. The obtained liquid crystal display device was subjected to the same evaluation as in Example 1. Table 1 shows the results.

[Comparative Example 1]
A liquid crystal display device was obtained in the same manner as in Example 4, except that the polarizing plate P1 obtained in Production Example 1 was used as it was (that is, no adhesion suppression layer was formed). The obtained liquid crystal display device was subjected to the same evaluation as in Example 1. Table 1 shows the results.

[Example 7]
A liquid crystal display device was obtained in the same manner as in Example 1, except that the adhesion suppressing layer was formed on the viewing side of the diffusion film instead of forming it on the polarizing plate P1. The obtained liquid crystal display device was subjected to the same evaluation as in Example 1. Table 1 shows the results.

[Example 8]
A liquid crystal display device was obtained in the same manner as in Example 3, except that the adhesion suppressing layer was formed on the viewing side of the prism film on the viewing side instead of forming it on the polarizing plate P1. The obtained liquid crystal display device was subjected to the same evaluation as in Example 1. Table 1 shows the results.

[evaluation]
As is clear from Table 1, the polarizing plate with an adhesion suppression layer and the liquid crystal display device using the polarizing plate of the example of the present invention satisfactorily suppress wet-out while maintaining brightness.

A polarizing plate with an adhesion suppression layer according to an embodiment of the present invention can be suitably used as a rear side polarizing plate of a liquid crystal display device, and a liquid crystal display device according to an embodiment of the present invention can be suitably used as various image display devices.

REFERENCE SIGNS LIST 10 polarizing plate 11 polarizer 12 first protective layer 13 second protective layer 21 first adhesive layer 22 second adhesive layer 30 adhesion suppression layer 100 polarizing plate with adhesion suppression layer 110 viewing side polarizing plate 130 liquid crystal Cell 170 Backlight unit 200 Liquid crystal display device

Claims (14)

A polarizing plate containing a polarizer, and an adhesion suppression layer disposed directly on one side of the polarizing plate or via an adhesive layer,
The adhesion suppression layer is a porous layer,
A polarizing plate with an adhesion suppression layer. 2. The polarizing plate with an adhesion suppression layer according to claim 1, wherein another pressure-sensitive adhesive layer is provided on the other side of said polarizing plate. 3. The polarizing plate with an adhesion-suppressing layer according to claim 1, wherein the adhesion-suppressing layer has a water contact angle of 90[deg.] or more. 4. The polarizing plate with an adhesion suppression layer according to claim 1, wherein the adhesion suppression layer has a porosity of 30% by volume to 80% by volume. 5. The polarizing plate with an adhesion suppression layer according to claim 4, wherein the adhesion suppression layer has a void size of 2 nm to 500 nm. 6. The polarizing plate with an adhesion suppression layer according to claim 5, wherein the adhesion suppression layer has a refractive index of 1.05 to 1.30. 7. The polarizing plate with an adhesion suppression layer according to claim 6, wherein the adhesion suppression layer has a haze of 0.1% or more and less than 5.0%. 8. The polarizing plate with an adhesion suppression layer according to claim 1, wherein the adhesion suppression layer has a thickness of 0.1 μm to 100 μm. A liquid crystal cell, a viewing side polarizing plate arranged on the viewing side of the liquid crystal cell, and a polarizing plate with an adhesion suppression layer according to any one of claims 1 to 8 arranged on the side opposite to the viewing side of the liquid crystal cell. and
The adhesion-suppressing layer-attached polarizing plate is arranged such that the adhesion-suppressing layer is on the side opposite to the viewing side of the polarizing plate.
Liquid crystal display. 10. The liquid crystal display device according to claim 9, further comprising a backlight unit including a light source on the side opposite to the viewing side of the polarizing plate with the adhesion suppression layer. 11. The liquid crystal display device according to claim 10, further comprising at least one optical film selected from a reflective polarizer, a diffusion film, and a prism film between the polarizing plate with an adhesion suppression layer and the backlight unit. . 12. The liquid crystal display device according to claim 11, wherein the optical film closest to the viewing side among the optical films is arranged with the polarizing plate with the adhesion suppression layer via an air layer. 12. The liquid crystal display device according to claim 11, wherein the optical film closest to the viewer among the optical films is attached to the polarizing plate with the adhesion suppression layer. A liquid crystal cell, a viewing side polarizing plate arranged on the viewing side of the liquid crystal cell, a back side polarizing plate arranged on the side opposite to the viewing side of the liquid crystal cell, a backlight unit, and the back side polarizing plate at least one optical film disposed between the backlight unit;
An adhesion suppression layer is formed on the viewing side of the optical film closest to the viewing side of the at least one optical film, and the adhesion suppression layer is a porous layer.
Liquid crystal display.

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