Polarizing plate group and liquid crystal panel

Abstract

The invention provides a polarizing plate group and a liquid crystal panel. The liquid crystal panel is required to further improve the contrast ratio under a specified visual angle. The polarizing plate group is used for being bonded to both surfaces of a liquid crystal cell having a specific liquid crystal layer. The liquid crystal display device has a first polarizing plate (10) disposed on one surface of the liquid crystal cell and a second polarizing plate (20) disposed on the other surface of the liquid crystal cell. The first polarizing plate (10) has a first polarizer (31), a phase difference layer, and a first protective film (32), the phase difference layer is disposed between the liquid crystal cell and the first polarizer (31), the phase difference layer satisfies formulae (1)-(3), and the first protective film (32) satisfies formulae (4)-(6). The second polarizing plate (20) has a second polarizer (51) and a second protective film (52). The second protective film (52) is disposed between the liquid crystal cell and the second polarizing plate (51), and the second protective film (52) satisfies formulae (7) and (8). The slow axis of the retardation layer is substantially parallel or substantially orthogonal to the absorption axis of the first polarizer (31).

Description

Technical Field

[0001] The present invention relates to a polarizing plate group and a liquid crystal panel. Background Art

[0002] Liquid crystal display devices (LCDs) are widely used not only for liquid crystal televisions but also for mobile applications such as personal computers and mobile phones, and in-vehicle applications such as car navigation systems. Generally, a liquid crystal display device has a liquid crystal panel member in which polarizing plates are bonded to both sides of a liquid crystal cell using an adhesive, and displays an image by controlling light from a backlight member using the liquid crystal panel member. In addition, organic EL display devices have also recently been widely used for mobile applications such as televisions and mobile phones, and in-vehicle applications such as car navigation systems, similar to liquid crystal display devices. In a liquid crystal display device, a retardation film is used to impart a wide viewing angle function.

[0003] The opportunity for polarizing plates to be mounted in vehicles as optical components of liquid crystal display devices has increased. For polarizing plates used in in-vehicle display devices, particularly wide viewing angle characteristics are required in order to reliably confirm the display from the driver's seat or the like. In particular, in a liquid crystal cell of the in-plane switching (IPS) mode, liquid crystal molecules are uniformly aligned (Japanese: homogeneous alignment) in a direction substantially parallel to the substrate surface in the absence of an electric field, and the liquid crystal molecules are rotated in a plane parallel to the substrate surface by applying a lateral electric field to control light transmission (white display) and light shielding (black display). As in the IPS mode, a liquid crystal panel of a lateral electric field mode in which liquid crystal molecules are uniformly aligned in the absence of an electric field has excellent viewing angle characteristics.

[0004] In Patent Document 1, a polarizing plate including a retardation film made of a cyclic olefin-based resin film is described for expanding the viewing angle. However, further improvement of the viewing angle characteristics is required. For example, improving the contrast at an azimuth angle of θ = 42.4° and an elevation angle of φ = 23.4° has become an index.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Patent No. 5383594 Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] It is necessary to further improve the viewing angle characteristics of in-vehicle liquid crystal display devices. For example, it is required to further improve the contrast at an azimuth angle of θ = 42.4° and an elevation angle of φ = 23.4°.

[0010] Means for Solving the Problems

[0011] The present invention provides the following polarizing plate group and liquid crystal panel.

[0012] [Invention 1]

[0013] A polarizing plate assembly is used to be respectively attached to both sides of a liquid crystal cell having a liquid crystal layer, the liquid crystal layer containing liquid crystal molecules uniformly oriented in the absence of an electric field.

[0014] The polarizing plate assembly has a first polarizing plate disposed on one side of the liquid crystal cell and a second polarizing plate disposed on the other side of the liquid crystal cell.

[0015] The first polarizing plate described above has a first polarizer, a phase difference layer, and a first protective film.

[0016] The aforementioned phase retardation layer is disposed between the aforementioned liquid crystal cell and the aforementioned first polarizer.

[0017] The aforementioned phase difference layer satisfies the following equations (1) to (3).

[0018] ny

[590] <nz

[590] <nx

[590] (1)

[0019] 0.8≤Re

[480] / Re

[590] ≤1.2 (2)

[0020] 100nm≤Re

[590] ≤150nm (3)

[0021] The first protective film mentioned above satisfies the following equations (4) to (6).

[0022] 0nm≤Re

[550] ≤5nm (4)

[0023] -5nm≤Rth

[550] ≤5nm (5)

[0024] -30nm≤Rth

[450] ≤-1.0nm (6)

[0025] The aforementioned second polarizing plate has a second polarizer and a second protective film.

[0026] The second protective film is disposed between the liquid crystal cell and the second polarizer.

[0027] The second protective film described above satisfies the following equations (7) and (8).

[0028] 0nm≤Re

[550] ≤5nm (7)

[0029] -5nm≤Rth

[550] ≤5nm (8)

[0030] The slow axis of the aforementioned phase difference layer is approximately parallel or approximately orthogonal to the absorption axis of the aforementioned first polarizer.

[0031] [Invention 2]

[0032] According to the polarizing plate assembly described in [Invention 1], the orthogonal transmittance of the first polarizer and the second polarizer at a wavelength of 410 nm is 0.05% or less.

[0033] [Invention 3]

[0034] According to the polarizing plate assembly described in [Invention 1] or [Invention 2], the second protective film described above also satisfies the following formula (9).

[0035] -30nm≤Rth

[450] ≤-1.0nm (9)

[0036] [Invention 4]

[0037] According to any one of [Invention 1] to [Invention 3], the polarizing plate assembly wherein the phase difference layer has a positive A plate and a positive C plate.

[0038] [Invention 5]

[0039] A liquid crystal panel having:

[0040] A liquid crystal cell having a liquid crystal layer containing liquid crystal molecules uniformly oriented in the absence of an electric field;

[0041] A first polarizing plate, which is disposed on one side of the aforementioned liquid crystal cell; and

[0042] The second polarizing plate is disposed on the other side of the aforementioned liquid crystal cell.

[0043] The first polarizing plate described above has a first polarizer, a phase difference layer, and a first protective film.

[0044] The aforementioned phase retardation layer is disposed between the aforementioned liquid crystal cell and the aforementioned first polarizer.

[0045] The aforementioned phase difference layer satisfies the following equations (1) to (3).

[0046] ny

[590] <nz

[590] <nx

[590] (1)

[0047] 0.8≤Re

[480] / Re

[590] ≤1.2 (2)

[0048] 100nm≤Re

[590] ≤150nm (3)

[0049] The first protective film mentioned above satisfies the following equations (4) to (6).

[0050] 0nm≤Re

[550] ≤5nm (4)

[0051] -5nm≤Rth

[550] ≤5nm (5)

[0052] -30nm≤Rth

[450] ≤-1.0nm (6)

[0053] The aforementioned second polarizing plate has a second polarizer and a second protective film.

[0054] The second protective film is disposed between the liquid crystal cell and the second polarizer.

[0055] The second protective film described above satisfies the following equations (7) and (8).

[0056] 0nm≤Re

[550] ≤5nm (7)

[0057] -5nm≤Rth

[550] ≤5nm (8)

[0058] The slow axis of the aforementioned phase retardation layer is approximately parallel to or approximately orthogonal to the absorption axis of the aforementioned first polarizer.

[0059] The absorption axis of the first polarizer is approximately orthogonal to the absorption axis of the second polarizer.

[0060] [Invention 6]

[0061] According to the liquid crystal panel described in [Invention 5], the second protective film also satisfies the following formula (9).

[0062] -30nm≤Rth

[450] ≤-1.0nm (9)

[0063] [Invention 7]

[0064] According to the liquid crystal panel described in [Invention 5] or [Invention 6], the cross-transmittance of the first polarizer and the second polarizer at a wavelength of 410 nm is 0.05% or less.

[0065] [Invention 8]

[0066] According to any one of [Invention 5] to [Invention 7], the liquid crystal panel wherein the phase difference layer has a positive A plate and a positive C plate.

[0067] Invention Effects

[0068] According to the polarizing plate assembly of the present invention, the contrast of the liquid crystal panel at an azimuth angle of θ42.4° and an elevation angle of φ23.4° can be further improved. Attached Figure Description

[0069] Figure 1(a) is a schematic cross-sectional view of one polarizer of the polarizer assembly of the present invention. Figure 1 (b) is a schematic cross-sectional view of another polarizing plate in the polarizing plate assembly of the present invention.

[0070] Figure 2 This is a schematic perspective view showing an example of a preferred axial configuration of the liquid crystal panel of the present invention.

[0071] Explanation of reference numerals in the attached figures

[0072] 10…First polarizing plate

[0073] 20…Second polarizing plate

[0074] 31… First polarizer

[0075] 32…First protective film

[0076] 32a…a first protective film

[0077] 32b…another first protective film

[0078] 35… Adhesive layer

[0079] 40…phase difference layer

[0080] 41… Positive A-plate

[0081] 42… Positive C plate

[0082] 51…Second polarizer

[0083] 52…Second protective film

[0084] 52a…a second protective film

[0085] 52b…another second protective film Detailed Implementation

[0086] The polarizing plate assembly of the present invention will be described below.

[0087] <Polarizing Plate Assembly>

[0088] like Figure 1 As shown in (a) and (b), the polarizing plate assembly is disposed in the liquid crystal cell 60 (see reference). Figure 2 The liquid crystal cell 60 consists of a first polarizing plate 10 on the observation side of one side and a second polarizing plate 20 on the back side of the other side.

[0089] <First Polarizing Plate>

[0090] The first polarizer 10 has a polarizer (hereinafter also referred to as the first polarizer 31), a first protective film 32 (hereinafter also referred to as a first protective film 32a) laminated on one side of the first polarizer 31, a phase retardation layer 40 laminated on the other side, and a first protective film 32 (hereinafter also referred to as another first protective film 32b) laminated on the phase retardation layer 40.

[0091] [Polarizer #1]

[0092] In this invention, a polarizer is used, which is formed by adsorbing and oriented dichroic pigments such as iodine onto a polyvinyl alcohol (hereinafter also referred to as PVA)-based resin layer. Examples of such polarizers include: polarizers formed by dyeing a PVA-based resin film with dichroic pigments such as iodine and then uniaxially stretching it; and polarizers formed by coating a substrate film with a coating solution containing PVA-based resin, dyeing the PVA-based resin layer (which is the coating layer of the laminated film) with dichroic pigments such as iodine, and then uniaxially stretching the laminated film.

[0093] The polarizer is formed from a PVA-based resin obtained by saponifying a polyvinyl acetate-based resin. Besides polyvinyl acetate as a homopolymer of vinyl acetate, copolymers of vinyl acetate and other monomers that can be copolymerized with it can also be mentioned. Examples of other monomers that can be copolymerized include unsaturated carboxylic acids, olefins such as ethylene, vinyl ethers, and unsaturated sulfonic acids.

[0094] The saponification value of the PVA-based resin is preferably about 85 mol% or more, more preferably about 90 mol% or more, and even more preferably about 99 mol% to 100 mol%. The degree of polymerization of the PVA-based resin is 1000 to 10000, preferably 1500 to 5000. This PVA-based resin can be modified, for example, it can be aldehyde-modified polyvinyl formal, polyvinyl acetal, polyvinyl butyral, etc.

[0095] The thickness of the polarizer in this embodiment is preferably 5 to 50 μm, more preferably 8 to 28 μm, even more preferably 12 to 22 μm, and most preferably 12 to 15 μm. By making the thickness of the polarizer 5 μm or more, it is easy to manufacture a configuration that achieves the desired optical properties.

[0096] The cross-transmittance of the first polarizer 31 at a wavelength of 410 nm is preferably less than 0.05%, less than 0.03%, or less than 0.01%. The cross-transmittance of the first polarizer 31 at a wavelength of 410 nm can be greater than 0.001%. The cross-transmittance can be measured using a commercially available spectrophotometer. If the cross-transmittance is within the above range, the contrast ratio of the liquid crystal panel at an azimuth angle of θ42.4° and an elevation angle of φ23.4° can be further improved.

[0097] [Manufacturing method of the first polarizer]

[0098] There is no particular limitation on the manufacturing method of polarizers. A typical method is to send out a pre-wound polyvinyl alcohol resin film and perform processes such as swelling, dyeing, cross-linking, stretching, color correction, and washing. Another method includes stretching a laminate, which is obtained by coating a polyvinyl alcohol resin layer as a coating layer by coating a coating liquid containing polyvinyl alcohol resin onto a substrate film.

[0099] The swelling process involves immersing a polyvinyl alcohol (PVA) resin film in a swelling bath. This process removes surface contaminants and adhesives from the PVA resin film. Furthermore, by swelling the PVA resin film, uneven dyeing can be suppressed. The swelling bath typically uses a water-based medium, such as water, distilled water, or pure water. Surfactants and alcohols can be added to the swelling bath using conventional methods. Additionally, from the viewpoint of controlling the potassium content of the polarizing element, potassium iodide can be used in the swelling bath. In this case, the concentration of potassium iodide in the swelling bath is preferably 1.5% by mass or less, more preferably 1.0% by mass or less, and even more preferably 0.5% by mass or less.

[0100] The temperature of the swelling bath is preferably around 10–60°C, more preferably around 15–45°C, and even more preferably around 18–30°C. Furthermore, since the degree of swelling of the polyvinyl alcohol-based resin film is affected by the temperature of the swelling bath, the immersion time in the swelling bath cannot be fixed. It is preferably around 5–300 seconds, more preferably around 10–200 seconds, and even more preferably around 20–100 seconds. The swelling process can be performed only once or multiple times as needed.

[0101] The dyeing process involves immersing a polyvinyl alcohol (PVA) resin film in a dyeing bath (iodine solution), which allows dichroic substances such as iodine or dichroic dyes to be adsorbed and oriented on the PVA resin film. The iodine solution is typically an aqueous iodine solution containing iodine and iodides as a dissolving agent. It should be noted that examples of iodides include potassium iodide, lithium iodide, sodium iodide, zinc iodide, aluminum iodide, lead iodide, copper iodide, barium iodide, calcium iodide, tin iodide, and titanium iodide. Among these, potassium iodide is suitable from the viewpoint of controlling the potassium content in the polarization element.

[0102] In the staining bath, the concentration of iodine is preferably about 0.01 to 1% by mass, more preferably about 0.02 to 0.5% by mass. In the staining bath, the concentration of iodide is preferably about 0.01 to 10% by mass, more preferably about 0.05 to 5% by mass, and even more preferably about 0.1 to 3% by mass.

[0103] The temperature of the dyeing bath is preferably around 10–50°C, more preferably around 15–45°C, and even more preferably around 18–30°C. Furthermore, since the degree of dyeing of the polyvinyl alcohol-based resin film is affected by the temperature of the dyeing bath, the immersion time in the dyeing bath cannot be fixed; it is preferably around 10–300 seconds, more preferably around 20–240 seconds. The dyeing process can be performed only once or multiple times as needed.

[0104] The crosslinking process involves immersing a polyvinyl alcohol (PVA) resin film, which has been dyed in a dyeing process, in a treatment bath (crosslinking bath) containing a boron compound. The PVA resin film is crosslinked by the boron compound, allowing iodine molecules or dye molecules to adsorb onto the crosslinked structure. Examples of boron compounds include boric acid, borates, and borax. The crosslinking bath is typically an aqueous solution, but it can also be a mixture of water and an organic solvent that is miscible with water. Furthermore, from the viewpoint of controlling the potassium content in the polarizing element, the crosslinking bath preferably contains potassium iodide.

[0105] In the crosslinking bath, the concentration of the boron compound is preferably about 1 to 15% by mass, more preferably about 1.5 to 10% by mass, and even more preferably about 2 to 5% by mass. Furthermore, when potassium iodide is used in the crosslinking bath, the concentration of potassium iodide is preferably about 1 to 15% by mass, more preferably about 1.5 to 10% by mass, and even more preferably about 2 to 5% by mass.

[0106] The temperature of the crosslinking bath is preferably around 20–70°C, more preferably around 30–60°C. Furthermore, since the degree of crosslinking of the polyvinyl alcohol resin film is affected by the temperature of the crosslinking bath, the immersion time in the crosslinking bath cannot be fixed; it is preferably around 5–300 seconds, more preferably around 10–200 seconds. The crosslinking process can be performed only once, or multiple times as needed.

[0107] The stretching process is a process of stretching a polyvinyl alcohol (PVA) resin film to a specified ratio along at least one direction. Typically, the PVA resin film is uniaxially stretched along the transport direction (length direction). There are no particular restrictions on the stretching method; either wet stretching or dry stretching can be used. The stretching process can be performed once or multiple times as needed. The stretching process can be performed at any stage in the manufacturing of polarizing elements.

[0108] The treatment bath (stretching bath) in the wet stretching method can typically be water, or a mixture of water and an organic solvent miscible with water. From the viewpoint of controlling the potassium ion content in the polarization element, the stretching bath preferably contains potassium iodide. When potassium iodide is used in the stretching bath, its concentration is preferably about 0.1 to 15% by mass, more preferably about 2 to 10% by mass, and even more preferably about 3 to 6% by mass. Furthermore, from the viewpoint of suppressing film breakage during stretching, the treatment bath (stretching bath) may contain a boron compound. In this case, the concentration of the boron compound is preferably about 1 to 15% by mass, more preferably about 1.5 to 10% by mass, and even more preferably about 2 to 5% by mass.

[0109] The temperature of the stretching bath is preferably 25–80°C, more preferably 40–80°C, further preferably 50–75°C, and particularly preferably 65–75°C. Increasing the temperature of the stretching bath makes it easier to retain the second metal ions used in the metal ion treatment step described later within the PVA-based resin layer. By increasing the temperature of the stretching bath, it is possible to raise it to a temperature near or above the softening point of the PVA in the PVA-based resin layer. As a result, it is presumed that the crystallization ratio of PVA decreases, or the PVA crystals become smaller, and the uptake of the second metal ions increases. Furthermore, since the degree of stretching of the polyvinyl alcohol-based resin film is affected by the temperature of the stretching bath, the immersion time in the stretching bath cannot be fixed in general; it is preferably about 10–800 seconds, more preferably about 30–500 seconds. It should be noted that the stretching step in the wet stretching method can be performed alone, or it can be performed together with one or more of the following treatment steps: swelling, dyeing, crosslinking, and cleaning, or they can be combined. When performed in conjunction with one or more processing steps, the crosslinking process is particularly suitable for setting the temperature of the processing bath to 65-75°C, which is optimal for the stretching process. When stretching is performed in multiple processing baths, the temperature of at least one processing bath is preferably 65-75°C, and the immersion time in the processing bath at 65-75°C is preferably 40-200 seconds.

[0110] (Touch-up process)

[0111] The color matching process is a treatment to adjust the hue of the film. This can be done by immersing the cross-linked film in a color matching bath (a color matching solution stored in a color matching tank) for a specified time, and then pulling it out.

[0112] The complementary color solution may be an aqueous solution containing, for example, about 1 to 10 parts by mass of boric acid relative to 100 parts by mass of water. When the dichroic pigment used in the dyeing process is iodine, the complementary color solution preferably contains an iodide in addition to boric acid, and the amount of iodide relative to 100 parts by mass of water may be, for example, 1 to 30 parts by mass. Examples of iodides include potassium iodide and zinc iodide. Two or more iodides may also be contained. Furthermore, compounds other than iodides, such as sodium thiosulfate, potassium sulfite, and sodium sulfate, may also coexist. Additionally, nitrates may coexist. The nitrate may contain at least one selected from aluminum nitrate, copper nitrate, sodium nitrate, potassium nitrate, zinc nitrate, and magnesium nitrate. Zinc nitrate is preferably included in the nitrate.

[0113] In the complementary color solution, for example, when iodine is used as a dichroic pigment, a concentration can be used at a mass ratio of boric acid / iodide / water of 1–5 / 3–30 / 100. The temperature of the complementary color bath during film impregnation is typically 10–45°C, and the film impregnation time is typically 1–300 seconds, preferably 2–100 seconds.

[0114] Complementary color processing can be performed multiple times, for example, 2 to 5 times. In this case, the composition and temperature of each complementary color bath used only need to be within the above-mentioned range; they can be the same or different.

[0115] The cleaning process involves immersing the PVA-based resin film in a cleaning bath to remove foreign matter remaining on the surface of the PVA-based resin film. The cleaning bath typically uses a water-based medium, such as water, distilled water, or pure water. Furthermore, from the viewpoint of controlling the potassium content in the polarizing layer, the cleaning bath preferably contains potassium iodide. In this case, the concentration of potassium iodide in the cleaning bath is preferably about 1 to 10% by weight, more preferably about 1.5 to 4% by weight, and even more preferably about 1.8 to 3.8% by weight.

[0116] The temperature of the cleaning bath is preferably around 5–50°C, more preferably around 10–40°C, and even more preferably around 15–30°C. Since the degree of cleaning of the PVA resin film is affected by the temperature of the cleaning bath, the immersion time in the cleaning bath cannot be fixed. It is preferably around 1–100 seconds, more preferably around 2–50 seconds, and even more preferably around 3–20 seconds. The cleaning process can be performed only once or multiple times as needed.

[0117] Finally, a drying process is performed to dry the PVA-based resin film after the cleaning process to obtain the polarizing layer. Drying is carried out by any suitable method, such as natural drying, forced air drying, or heat drying. The drying temperature is, for example, 30–100°C, and the drying time is, for example, 30–600 seconds.

[0118] To ensure that the cross-transmittance of the first polarizer 31 at a wavelength of 410 nm is less than 0.05%, for example, the polyiodine (I3) in the PVA resin can be adjusted by making the iodine concentration in the dyeing process 0.3% by mass or more, making the amount of iodide in the color-correcting process 2 parts by mass or more relative to 100 parts by mass of water, and making the maximum drying temperature in the drying process 80°C or more. - / I5 - The balance of ) is achieved, thus creating the effect. By setting the orthogonal transmittance at a wavelength of 410nm to below 0.05%, the bluing effect in the tilted field of view can be suppressed, resulting in a further improvement in viewing angle contrast.

[0119] [Phase difference layer]

[0120] The phase difference layer 40 uses a phase difference layer that satisfies the following equations (1) to (3).

[0121] ny

[590] <nz

[590] <nx

[590] (1)

[0122] 0.8≤Re

[480] / Re

[590] ≤1.2 (2)

[0123] 100nm≤Re

[590] ≤150nm (3)

[0124] Here, nx[λ] is the refractive index in the x-direction (in-plane slow axis direction) of the film plane at wavelength λnm, ny[λ] is the refractive index in the y-direction (in-plane fast axis direction) of the film plane at wavelength λnm, and nz[λ] is the refractive index in the direction perpendicular to the film plane (thickness direction) at wavelength λnm. The in-plane phase difference Re[λ] at wavelength λnm is defined by the following equation (10). In addition, the phase difference Rth[λ] in the thickness direction at wavelength λnm is defined by the following equation (11).

[0125] Re[λ]=(nx[λ]-ny[λ])×d (10)

[0126] Rth[λ]={(nx[λ]+ny[λ]) / 2-nz[λ]}×d (11)

[0127] Here, d represents the film thickness (nm). The phase difference in the in-plane direction and the phase difference in the thickness direction can be measured using the methods described in the examples below.

[0128] The retardation layer 40 can be a single-layer retardation layer or a retardation layer composed of two or more laminated films. For example, a retardation layer composed of a positive A plate 41 and a positive C plate 42 is preferred. The slow axis of the retardation layer 40 is approximately parallel or approximately orthogonal to the absorption axis of the first polarizer 31. Approximately orthogonal means that the angle between the two directions is, for example, within the range of 90° ± 3°. Approximately parallel means that the angle between the two directions is, for example, within the range of 0° ± 3°.

[0129] The positive A plate 41 used in this invention refers to a phase retardation layer that satisfies the relationship nx

[590] > ny

[590] ≈ nz

[590] . Here, ny

[590] ≈ nz

[590] also includes the case where ny and nz are substantially equal at a wavelength of 590 nm. In this invention, substantially equal refractive indices means that the difference in refractive indices is within 0.005.

[0130] For example, olefin-based resin films formed using olefin-based resins can be cited as a positive A-plate 41. Examples of olefin-based resins include resins that primarily comprise structural units derived from alicyclic olefins such as ethylene and propylene, or norbornene, and their substituted derivatives (hereinafter, sometimes collectively referred to as "norbornene monomers"). "Primarily comprised structural units" means that the proportion of structural units contained in the resin, based on a molar ratio, is 50% or more. Olefin-based resins can be copolymers using two or more monomers.

[0131] The positive A plate 41 is preferably a cyclic olefin resin film formed using a cyclic olefin resin, which is a resin mainly comprising structural units derived from alicyclic olefins. Typical examples of alicyclic olefins constituting the cyclic olefin resin include norbornene monomers. Norbornene is a compound in which one carbon-carbon bond of norbornene becomes a double bond, and is named bicyclo[2,2,1]hept-2-ene according to IUPAC nomenclature. Examples of substitutes for norbornene include 3-substituted derivatives, 4-substituted derivatives, and 4,5-disubstituted derivatives, with the double bond position of norbornene set at the 1,2-position; further examples include dicyclopentadiene and dimethylbridged octahydronaphthalene.

[0132] Cyclic olefin resins may or may not contain a norbornene ring in their structural units. Examples of norbornene monomers that form cyclic olefin resins without a norbornene ring in their structural units include norbornene monomers that form 5-membered rings through ring-opening, such as norbornene, dicyclopentadiene, 1- or 4-methylnorbornene, and 4-phenylnorbornene. When the cyclic olefin resin is a copolymer, the molecular arrangement is not particularly limited; it can be a random copolymer, a block copolymer, or a graft copolymer.

[0133] More specific examples of cyclic olefin resins include ring-opening polymers of norbornene monomers, ring-opening copolymers of norbornene monomers with other monomers, polymer-modified products obtained by maleic acid addition, cyclopentadiene addition, etc., and polymers or copolymers obtained by hydrogenation of these monomers; addition polymers of norbornene monomers, and addition copolymers of norbornene monomers with other monomers. Other monomers used in the preparation of copolymers include α-olefins, cyclic olefins, and non-conjugated dienes. Furthermore, cyclic olefin resins may also be copolymers using one or more of norbornene monomers and other alicyclic olefins. Among these, resins obtained by hydrogenation of ring-opening polymers or ring-opening copolymers using norbornene monomers are preferred.

[0134] Commercially available products using the aforementioned cyclic olefin resins that utilize norbornene monomers are all designated by trade names, such as "Zeonex" and "Zeonor" sold by ZEON Corporation of Japan, and "Arton" sold by JSR Corporation. Films and stretched films of these cyclic olefin resins are also commercially available, for example, under trade names such as "Zeonor Film" manufactured by OPTES Corporation, "Arton Film" manufactured by JSR Corporation, and "Escena" manufactured by Sekisui Chemicals Co., Ltd.

[0135] As the positive A-plate 41, a film formed from a mixed resin containing two or more olefin resins, or a film formed from a mixed resin containing olefin resins and other thermoplastic resins, can also be used. For example, as a mixed resin containing two or more olefin resins, a mixture of cyclic olefin resins and chain aliphatic olefin resins as described above can be cited. When using a mixed resin containing olefin resins and other thermoplastic resins, the other thermoplastic resins are appropriately selected according to the purpose. Specific examples of other thermoplastic resins include polyvinyl chloride (PVC) resins, cellulose resins, polystyrene resins, acrylonitrile / butadiene / styrene copolymer resins, acrylonitrile / styrene copolymer resins, (meth)acrylic acid resins, polyvinyl acetate (PVC) resins, polyvinylidene chloride (PVDC) resins, polyamide resins, polyacetal resins, polycarbonate resins, modified polyphenylene ether (PPE) resins, polybutylene terephthalate (PET) resins, polyethylene terephthalate (PET) resins, polyphenylene sulfide (PPS) resins, polysulfone resins, polyethersulfone (PES) resins, polyetheretherketone (PEEK) resins, polyarylate resins, liquid crystal resins, polyamide-imide resins, polyimide resins, and polytetrafluoroethylene (PTFE) resins. These thermoplastic resins can be used individually or in combination of two or more. Furthermore, the aforementioned thermoplastic resins can also be used after undergoing any appropriate polymer modification. Examples of polymer modification include copolymerization, crosslinking, molecular end modification, and imparting stereoregularity.

[0136] When using a mixture of olefin-based resins and other thermoplastic resins, the content of the other thermoplastic resins is typically about 50% by weight or less relative to the total resin content, preferably about 40% by weight or less. By setting the content of the other thermoplastic resins within this range, a retardation film with a small absolute value of photoelasticity, exhibiting good wavelength dispersion characteristics, and possessing excellent durability, mechanical strength, and transparency can be obtained.

[0137] The A-grade sheet 41 may contain residual solvents, stabilizers, plasticizers, anti-aging agents, antistatic agents, and UV absorbers, among other ingredients, as needed. Additionally, leveling agents may be included to reduce surface roughness.

[0138] The positive A plate 41 preferably has an in-plane phase difference value, and the in-plane phase difference value Re

[590] at a wavelength of 590 nm can be 100 nm or more, preferably 105 nm or more, more preferably 110 nm or more, and can also be 150 nm or less, or 140 nm or less. The positive A plate 41 is preferably a stretch film.

[0139] In addition, as a wavelength dispersion characteristic of the positive A plate 41, Re

[480] / Re

[590] can be 0.8 or more, preferably 0.9 or more, can be 1.2 or less, and preferably 1.1 or less.

[0140] The thickness of the positive A plate 41 is not particularly limited, but is preferably 15 μm or more and 80 μm or less, more preferably 18 μm or more and 45 μm or less, and most preferably 20 μm or more and 30 μm or less. When the thickness of the retardation film is less than 15 μm, there is a tendency for the film to be difficult to operate and for the specified phase difference value to be difficult to be displayed. On the other hand, when the thickness of the retardation film exceeds 80 μm, the processability deteriorates, and there is a tendency for the transparency to decrease or the weight of the obtained polarizing plate to increase.

[0141] The positive A plate 41 can be obtained by stretching a resin film formed using the aforementioned resin. The resin film can be obtained, for example, by casting or melt extrusion of a solution containing the aforementioned olefin resin. When using a mixture of two or more resins to form the film, there are no particular limitations on the film-forming method. Examples include casting a film using a homogeneous solution obtained by mixing resin components with a solvent in a specified ratio, or melt extrusion of resin components in a specified ratio.

[0142] For stretching treatment of resin films, well-known methods include longitudinal uniaxial stretching, transverse uniaxial stretching with a tenter frame, simultaneous biaxial stretching, and successive biaxial stretching. In addition to appropriately adjusting the stretching ratio and stretching speed to obtain the desired phase difference value, the stretching treatment can be carried out by appropriately selecting various temperatures and modes such as preheating temperature, stretching temperature, heat setting temperature, and cooling temperature.

[0143] The phase retardation layer 40 is preferably composed of a stack of the positive A plate 41 and the positive C plate 42 described above. The positive C plate 42 is a phase retardation layer that satisfies nz

[590] > nx

[590] ≈ ny

[590] . Here, nx

[590] ≈ ny

[590] also includes the case where nx and ny are substantially equal at a wavelength of 590 nm.

[0144] As the positive C-plate 42, a known positive C-plate can be used. For example, as the positive C-plate 42, a solidified layer or cured layer of a liquid crystal composition in which the rod-shaped liquid crystal composition is oriented vertically is preferred.

[0145] Examples of liquid crystal compounds include those in which the liquid crystal phase is a nematic phase (nematic liquid crystals). Liquid crystal polymers and liquid crystal monomers can be used as examples of such liquid crystal compounds. The mechanism by which the liquid crystallization of the liquid crystal compound manifests can be lyotropic or thermotropic. Liquid crystal polymers and liquid crystal monomers can be used individually or in combination. Any suitable liquid crystal monomer can be used as the liquid crystal monomer. For example, polymerizable mesocrystalline compounds described in Japanese Patent Application Publication No. 2002-533742 (WO00 / 37585), EP358208 (US5211877), EP66137 (US4388453), WO93 / 22397, EP0261712, DE19504224, DE4408171, and GB2280445 can be used. Specific examples of such polymerizable mesocrystalline compounds include BASF's LC242, Merck's E7, and Wacker-Chem's LC-Sillicon-CC3767. Nematic liquid crystal monomers are preferred, for example. Detailed descriptions of specific examples of liquid crystal compounds and methods for forming the orientation-cured layer are provided in Japanese Patent Application Publication No. 2006-163343. This publication is incorporated herein by reference.

[0146] The liquid crystal curing layer can be configured to function optimally as the positive C-plate 42. In other words, the thickness can be set in a way that yields the desired optical properties. The thickness of the retardation layer is preferably 0.5 to 10 μm, more preferably 0.5 to 8 μm, and particularly preferably 0.5 to 5 μm.

[0147] The in-plane phase difference Re

[590] at a wavelength of 590 nm is preferably substantially zero for the positive C-plate 42. A substantially zero in-plane phase difference Re

[590] at a wavelength of 590 nm means that the absolute value of the in-plane phase difference is 10 nm or less. Furthermore, the phase difference in the thickness direction of the positive C-plate 42 at a wavelength of 590 nm can be -200 nm or more, preferably -170 nm or more, more preferably -150 nm or more, and can also be -10 nm or less, or -30 nm or less.

[0148] The phase difference layer 40 is adjusted by combining the positive A plate 41 and the positive C plate 42 to satisfy the above equations (1) to (3).

[0149] like Figure 2As shown, as a preferred embodiment, it is arranged such that the direction of the absorption axis of the first polarizer 31 (refer to the arrow) is substantially parallel to the direction of the slow axis of the positive A plate 41 contained in the retardation layer 40 (refer to the arrow). When laminated in this configuration, the positive C plate 42 contained in the retardation layer 40 is preferably arranged between the first polarizer 31 and the positive A plate 41 contained in the retardation layer 40.

[0150] Further, as another preferred embodiment, it is arranged such that the direction of the absorption axis of the first polarizer 31 (refer to the arrow) is substantially orthogonal to the direction of the slow axis of the positive A plate 41 contained in the retardation layer 40. When laminated in this configuration, the positive C plate 42 contained in the retardation layer 40 is preferably arranged on the surface of the positive A plate 41 contained in the retardation layer 40 opposite to the first polarizer 31.

[0151] [First protective film]

[0152] Another first protective film 32b in the first protective film 32 is laminated on the positive A plate 41. Another first protective film 32b satisfies the following formulas (4) to (6).

[0153] 0nm ≤ Re

[550] ≤ 5nm (4)

[0154] -5nm ≤ Rth

[550] ≤ 5nm (5)

[0155] -30nm ≤ Rth

[450] ≤ -1.0nm (6)

[0156] By making another first protective film 32b satisfy the above formulas (4) to (6), the viewing angle compensation effect brought by the retardation layer 40 can be further improved. For example, the contrast at the viewing angles of the azimuth angle θ42.4° and the elevation angle φ23.4° of the liquid crystal panel can be further improved.

[0157] The method of controlling another first protective film 32b within the numerical range of the above formulas (4) to (6) is not particularly limited.

[0158] The first protective film 32b can be a single-layer structure or can have a multi-layer structure of two or more layers. Although not particularly limited to materials, it can also be made by a combination of different wavelength dispersions and different inherent birefringences.

[0159] For example, as an example of a single-layer structure, the following method can be cited: a retardation adjuster (Japanese: レターデーション調整剤) with a large wavelength dispersion is added to the formed film obtained by the solvent casting method using a material with a small wavelength dispersion and a positive inherent birefringence, and the addition amount is adjusted to satisfy formula (5).

[0160] Another example is the biaxial stretching of a copolymer of polymeric units with inherent positive birefringence and low wavelength dispersion and polymeric units with inherent negative birefringence and high wavelength dispersion.

[0161] In a two-layer film structure, one method is to stack a layer with a positive Rth

[550] and a large Rth

[550] with low wavelength dispersion. In this case, each layer can be a coating layer, a cast film layer, or a combination of both. It may also include a liquid crystal alignment layer or a curing layer.

[0162] The Re

[550] of the other first protective film 32b can be less than 3 nm or less than 1 nm. The Rth

[550] of the other first protective film 32b can be less than 3 nm or less than 0 nm. The Rth

[450] of the other first protective film 32b can be less than -5 nm, less than -10 nm, greater than -25 nm, or greater than -20 nm.

[0163] The first protective film 32 is preferably made of a resin material with excellent transparency, mechanical strength, thermal stability, and moisture-blocking properties. There are no particular limitations on the material used for such a protective film; examples include films containing methyl methacrylate resins, polyolefin resins, cyclic olefin resins, polyvinyl chloride resins, cellulose resins, styrene resins, acrylonitrile-butadiene-styrene resins, acrylonitrile-styrene resins, polyvinyl acetate resins, polyvinylidene chloride resins, polyamide resins, polyacetal resins, polycarbonate resins, modified polyphenylene ether resins, polybutylene terephthalate resins, polyethylene terephthalate resins, polysulfone resins, polyethersulfone resins, polyarylate resins, polyamide-imide resins, and polyimide resins.

[0164] These resins can be used alone or in combination of two or more. Additionally, these resins can be used after any appropriate polymer modification, such as copolymerization, crosslinking, molecular terminaling, stereoregularity control, and mixing, including reactions between different polymers.

[0165] Among them, cellulose resin, (meth)acrylic resin, and polyethylene terephthalate resin are preferred as materials for the protective film.

[0166] Cellulose-based resins refer to cellulose organic esters or mixed cellulose organic esters obtained from raw materials such as cotton lint and wood pulp (broadleaf pulp, coniferous pulp), in which some or all of the hydrogen atoms in the hydroxyl groups of cellulose are replaced by acetyl groups, propionyl groups, and / or butyryl groups. Examples include cellulose-based resins containing cellulose acetates, propionates, butyrates, and mixtures thereof. Among these, triacetylcellulose membranes, diacetylcellulose membranes, cellulose acetate-propionate membranes, and cellulose acetate-butyrate membranes are preferred.

[0167] Methyl methacrylate resins refer to polymers containing 50% by weight or more methyl methacrylate units. The content of methyl methacrylate units is preferably 70% by weight or more, but can also be 100% by weight. Polymers containing 100% by weight of methyl methacrylate units are methyl methacrylate homopolymers obtained by polymerizing methyl methacrylate alone.

[0168] The methyl methacrylate resin can typically be obtained by polymerization of monofunctional monomers, polyfunctional monomers, free radical polymerization initiators, and chain transfer agents with methyl methacrylate as the main component.

[0169] There are no particular limitations on the monofunctional monomers that can copolymerize with methyl methacrylate. Examples include methyl methacrylates other than methyl methacrylates such as ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, 2-ethylhexyl methacrylate, and 2-hydroxyethyl methacrylate; and acrylates such as methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, 2-ethylhexyl acrylate, and 2-hydroxyethyl methacrylate. Hydroxyacrylates such as methyl 2-(hydroxymethyl)acrylate, methyl 3-(hydroxyethyl)acrylate, ethyl 2-(hydroxymethyl)acrylate, and butyl 2-(hydroxymethyl)acrylate; unsaturated acids such as methacrylic acid and acrylic acid; halogenated styrene such as chlorostyrene and bromostyrene; substituted styrene such as vinyltoluene and α-methylstyrene; unsaturated nitrile such as acrylonitrile and methacrylonitrile; unsaturated acid anhydrides such as maleic anhydride and citrate anhydride; and unsaturated imides such as phenylmaleimide and cyclohexylmaleimide. These monomers can be used individually or in combination of two or more.

[0170] There are no particular limitations on the multifunctional monomers that can copolymerize with methyl methacrylate. Examples include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, nonaethylene glycol di(meth)acrylate, and tetradecaethylene glycol (meth)acrylate, which are monomers obtained by esterifying the terminal hydroxyl groups of ethylene glycol or its oligomers with acrylic acid or methacrylate; monomers obtained by esterifying the terminal hydroxyl groups of propylene glycol or its oligomers with acrylic acid or methacrylate; neopentyl glycol di(meth)acrylate, hexanediol di(meth)acrylate, and butanediol di(meth)acrylate, which are monomers obtained by esterifying the hydroxyl groups of diols with acrylic acid or methacrylate. Monomers derived by esterification; monomers derived by esterifying the terminal hydroxyl groups of bisphenol A, its alkyl oxide adducts, or their halogenated derivatives with acrylic acid or methacrylate; monomers derived by esterifying polyols such as trimethylolpropane and pentaerythritol with acrylic acid or methacrylate, and monomers derived by ring-opening addition of glycidyl acrylate or glycidyl methacrylate epoxy groups to their terminal hydroxyl groups; monomers derived by ring-opening addition of glycidyl acrylate or glycidyl methacrylate epoxy groups to dicarboxylic acids such as succinic acid, adipic acid, terephthalic acid, phthalic acid, their halogenated derivatives, and their alkyl oxide adducts; aryl (meth)acrylates; and diaryl compounds such as divinylbenzene. Ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, and neopentyl glycol dimethacrylate are preferred.

[0171] Methyl methacrylate resins with such a composition can also be modified by further reacting the functional groups that copolymerize with the resin. Examples of such reactions include, for instance, the intramolecular demethanolization condensation reaction of the methyl acrylate group with the hydroxyl group of 2-(hydroxymethyl)acrylate, or the intramolecular dehydration condensation reaction of the carboxyl group of acrylic acid with the hydroxyl group of 2-(hydroxymethyl)acrylate.

[0172] Such methyl methacrylate resins are readily available in commercial products, for example, by trade name, SUMIPEX (manufactured by Sumitomo Chemical Co., Ltd.), ACRYPET (manufactured by Mitsubishi Rayon Co., Ltd.), DELPET (manufactured by Asahi Kasei Corporation), PARAPET (manufactured by Kuraray Co., Ltd.), and Acryviewa (manufactured by Nippon Shokubai Co., Ltd.).

[0173] Polyethylene terephthalate resins refer to resins in which at least 80 mol% of the repeating units are composed of polyethylene terephthalate, and may also contain other dicarboxylic acid components and diol components. There are no particular limitations on other dicarboxylic acid components; examples include isophthalic acid, p-β-oxyethoxybenzoic acid, 4,4'-dicarboxybiphenyl, 4,4'-dicarboxybenzophenone, bis(4-carboxyphenyl)ethane, adipic acid, sebacic acid, and 1,4-dicarboxycyclohexane, etc.

[0174] Other diol components are not specifically limited, but can include propylene glycol, butanediol, neopentyl glycol, diethylene glycol, cyclohexanediol, ethylene oxide adducts of bisphenol A, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol, etc.

[0175] These dicarboxylic acid and diol components can be used in combination of two or more as needed. Additionally, hydroxycarboxylic acids such as p-hydroxybenzoic acid can also be used in combination. Furthermore, as other copolymer components, dicarboxylic acid or diol components containing small amounts of amide bonds, carbamate bonds, ether bonds, and carbonate bonds can be used.

[0176] Methods for manufacturing polyethylene terephthalate (PET) resins include direct polycondensation of terephthalic acid and ethylene glycol (and other dicarboxylic acids or other diols as needed), polycondensation after transesterification of dialkyl terephthalic acid and ethylene glycol (and other dialkyl terephthalic acids or other diols as needed), and polycondensation of ethylene glycol esters of terephthalic acid (and other dicarboxylic acids as needed) (and other diol esters as needed) in the presence of a catalyst. Furthermore, solid-state polymerization can be performed as needed to increase the molecular weight or reduce low molecular weight components.

[0177] As a method for preparing a protective film for bonding to a polarizing film using cellulose-based resins, methyl methacrylate-based resins, and polyethylene terephthalate-based resins, the appropriate method can be selected, without particular limitation. For example, a solvent casting method can be used, in which resin dissolved in a solvent is cast onto a metallic tape or drum, and the solvent is dried to obtain a film; another method is a melt extrusion method, in which the resin is heated to above its melting temperature and mixed, extruded from a die, and cooled to obtain a film. In this melt extrusion method, a single-layer film can be extruded, or multiple layers can be extruded simultaneously.

[0178] In the resin material constituting the protective film, appropriate additives can be incorporated within a range that does not impair transparency. Examples of additives include antioxidants, ultraviolet absorbers, antistatic agents, lubricants, nucleating agents, antifogging agents, antiblocking agents, phase difference reducers, stabilizers, processing aids, plasticizers, impact-resistant additives, matting agents, antibacterial agents, and mildew inhibitors. More than one of these additives can be used, or a combination of several can be used.

[0179] The thickness of the protective film is not particularly limited; for example, it can be 5μm or more, 10μm or more, 20μm or more, or 30μm or more. It is typically below 120μm, but can also be below 110μm, 100μm or less, or even below 900μm. The protective film is usually a single-layer structure, but it can also have a multi-layer structure with two or more layers.

[0180] The protective film may have functional layers, such as hard coating, anti-glare layer, anti-reflective layer, and antistatic layer.

[0181] <Adhesive layer>

[0182] The stacking of the first polarizer 31 and the first protective film 32, the stacking of the phase retardation layer 40 and another first protective film 32b, and the stacking of the first polarizer 31 and the phase retardation layer 40 can use an adhesive layer formed using a known adhesive or an adhesive layer formed using a known adhesive.

[0183] Examples of adhesives include water-based adhesives, active energy radiation-cured adhesives, and thermosetting adhesives, with water-based adhesives and active energy radiation-cured adhesives being preferred. The thickness of the bonding layer formed using the adhesive can be, for example, 0.01 μm or more, 0.1 μm or more, 0.5 μm or more, or 1 μm or more; alternatively, it can be, for example, 20 μm or less, 15 μm or less, 10 μm or less, or 5 μm or less.

[0184] Examples of water-based adhesives include adhesives containing aqueous solutions of polyvinyl alcohol (PVA) resins and water-based two-component urethane emulsion adhesives. Among these, water-based adhesives containing aqueous solutions of PVA resins are particularly suitable. As for PVA resins, in addition to ethylene alcohol homopolymers obtained by saponifying polyvinyl acetate homopolymers, PVA copolymers obtained by saponifying copolymers of vinyl acetate and other monomers capable of copolymerization with it, or modified PVA polymers obtained by modifying their hydroxyl groups, can also be used. Water-based adhesives may contain crosslinking agents such as aldehyde compounds (glyoxal, etc.), epoxy compounds, melamine compounds, hydroxymethyl compounds, isocyanate compounds, amine compounds, and polyvalent metal salts.

[0185] When using a water-based adhesive, it is preferable to perform a drying process to remove water contained in the water-based adhesive after laminating it with the film to be bonded. After the drying process, a curing process can be performed, for example, at a temperature of 20–45°C.

[0186] Reactive energy radiation-curable adhesives refer to adhesives containing curable compounds that are cured by irradiation with reactive energy rays such as ultraviolet light, visible light, electron beams, and X-rays, preferably ultraviolet-curable adhesives. The curable compound can be a cationicly polymerizable curable compound or a free-radical polymerizable curable compound. Examples of cationicly polymerizable curable compounds include epoxy compounds (compounds having one or more epoxy groups within the molecule), oxetane compounds (compounds having one or more oxetane rings within the molecule), or combinations thereof. Examples of free-radical polymerizable curable compounds include (meth)acrylic acid compounds (compounds having one or more (meth)acryloyloxy groups within the molecule), other vinyl compounds with free-radical polymerizable double bonds, or combinations thereof. Cationicly polymerizable curable compounds and free-radical polymerizable curable compounds can be used in combination. Reactive energy radiation-curable adhesives typically also contain cationic polymerization initiators and / or free-radical polymerization initiators for initiating the curing reaction of the aforementioned curable compounds.

[0187] Adhesives exhibit adhesion by adhering themselves to the substrates, and are thus known as pressure-sensitive adhesives. Adhesives can be compositions primarily composed of resins such as (meth)acrylic, rubber, urethane, ester, silicone, and polyvinyl ether resins. Adhesive compositions based on (meth)acrylic resins, which offer excellent transparency, weather resistance, and heat resistance, are particularly suitable. Adhesives can be either radioactive ray-cured or thermosetting. The thickness of the bonded layer formed using the adhesive is typically 3 μm or more and 30 μm or less, preferably 3 μm or more and 25 μm or less.

[0188] As the (meth)acrylate resin (base polymer) contained in the adhesive composition, polymers or copolymers using one or more (meth)acrylates such as butyl (meth)acrylate, ethyl (meth)acrylate, isooctyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate as monomers are suitable. It is preferable to copolymerize the polar monomer with the base polymer. Examples of polar monomers include (meth)acrylate, 2-hydroxypropyl (meth)acrylate, hydroxyethyl (meth)acrylate, (meth)acrylamide, N,N-dimethylaminoethyl (meth)acrylate, and glycidyl (meth)acrylate, which have carboxyl, hydroxyl, amide, amino, or epoxy groups.

[0189] The adhesive composition may contain only the aforementioned base polymer, but typically also includes a crosslinking agent. Examples of crosslinking agents include those that are divalent or higher metal ions forming a carboxylic acid metal salt with a carboxyl group; those that are polyamine compounds forming an amide bond with a carboxyl group; those that are polyepoxides or polyols forming an ester bond with a carboxyl group; and those that are polyisocyanates forming an amide bond with a carboxyl group. Polyisocyanates are preferred.

[0190] It should be noted that, when using a water-based adhesive, it is preferable that the membrane of at least one of the first protective film 32 or the retardation layer 40 has a moisture permeability of 200 g / m³. 2 Water-based adhesives with a lifespan of 24 hours or more.

[0191] (Adhesive layer)

[0192] like Figure 1As shown in (a), the first polarizing plate 10 may have an adhesive layer 35 for attaching the first polarizing plate 10 to a display element of a liquid crystal display device, etc. The adhesive layer 35 is preferably disposed on another first protective film 32b. The adhesive layer 35 can be formed using an adhesive. Examples of adhesives used to form the aforementioned bonding layer include adhesives. The thickness of the adhesive layer 35 is not particularly limited, but is typically 3 μm or more and 50 μm or less, preferably 5 μm or more and 40 μm or less, and may also be 10 μm or more and 30 μm or less.

[0193] (Release film)

[0194] The first polarizing plate 10 may have a release film that can be peeled off relative to the adhesive layer 35. The release film is used to cover and protect the surface of the adhesive layer 35, or to support the adhesive layer 35. Examples of release films include those that have undergone a release treatment such as silicone treatment on the surface of the substrate resin film on the adhesive layer 35 side. Examples of resin materials constituting the substrate resin film include films formed using the resin materials described in the above-described substrate film. The substrate resin film may be a single-layer structure or a multi-layer structure with two or more layers.

[0195] (Manufacturing method of polarizing plate)

[0196] The manufacturing method of the first polarizer 10 is not particularly limited, and known methods can be used. For example, a laminate of the first polarizer 10 is produced by laminating a first protective film 32a on one side of the first polarizer 31 using a water-based adhesive, laminating a phase retardation layer 40 and another first protective film 32b on the other side of the first polarizer 31 using a water-based adhesive, and then drying the laminate to remove water from the water-based adhesive. Then, an adhesive layer 35 is laminated on the other first protective film 32b of the laminate, thereby obtaining the first polarizer 10 with an adhesive layer.

[0197] To improve the adhesion between the first protective film 32, the first polarizer 31, the phase retardation layer 40, and the functional layer constituting the first polarizer 10, surface activation treatment can be applied to the bonding surfaces of these films and layers. Examples of surface activation treatments include dry treatments such as corona treatment, plasma treatment, discharge treatment (glow discharge treatment, etc.), flame treatment, ozone treatment, UV ozone treatment, and ionizing active ray treatment (ultraviolet treatment, electron beam treatment, etc.); and wet treatments such as ultrasonic treatment, saponification treatment, and anchor coating treatment using solvents such as water and acetone. These surface activation treatments can be performed individually or in combination of two or more.

[0198] <Second Polarizing Plate>

[0199] The second polarizer 20 has a second polarizer 51 and a pair of protective films (hereinafter also referred to as second protective films 52) stacked on both sides of the second polarizer 51. Of the pair of second protective films 52, the second protective film 52 on the liquid crystal cell side is referred to as one second protective film 52a, and the second protective film 52 on the other side is referred to as another second protective film 52b. One second protective film 52a is disposed between the liquid crystal cell 60 and the second polarizer 51.

[0200] [Second polarizer]

[0201] The second polarizer 51 can be the same polarizer as the first polarizer 31 described above. Preferably, the cross-transmittance of the second polarizer 51 at a wavelength of 410 nm is 0.05% or less, specifically 0.03% or less, or 0.01% or less. The cross-transmittance of the second polarizer 51 at a wavelength of 410 nm can be 0.001% or more. If the cross-transmittance is within the above range, the contrast ratio of the liquid crystal panel at an azimuth angle θ42.4° and an elevation angle φ23.4° can be further improved.

[0202] [Second protective film]

[0203] The second protective film 52 can be the same as the first protective film 32 described above.

[0204] One of the pair of second protective films 52, the second protective film 52a, satisfies the following equations (7) and (8).

[0205] 0nm≤Re

[550] ≤5nm (7)

[0206] -5nm≤Rth

[550] ≤5nm (8)

[0207] A second protective film 52a preferably also satisfies the following formula (9).

[0208] -30nm≤Rth

[450] ≤-1.0nm (9)

[0209] If a second protective film 52a satisfies the above equations (7) to (9), then in addition to another first protective film 32b, a second protective film 52a can further improve the contrast of the liquid crystal panel at an azimuth angle of θ42.4° and an elevation angle of φ23.4°.

[0210] There are no particular restrictions on the method of controlling a second protective film 52a within the numerical range of the above formulas (7) to (9).

[0211] The second protective film 52 can be a single-layer structure or a multi-layer structure with two or more layers. Although not particularly limited to materials, it can also be made by a combination of different wavelength dispersions and different intrinsic birefringences.

[0212] For example, as an example of a single-layer structure, the following method can be cited: a retardation adjuster with a large wavelength dispersion is added to a formed film obtained by the solvent casting method using a material with a small wavelength dispersion and a positive intrinsic birefringence, and the addition amount is adjusted in a manner that satisfies equation (7).

[0213] In addition, a method of biaxially stretching a copolymer having a polymer unit with a positive intrinsic birefringence and a small wavelength dispersion and a polymer unit with a negative intrinsic birefringence and a high wavelength dispersion can also be cited.

[0214] In a two-layer film structure, a method of laminating a layer with a small wavelength dispersion and a positive Rth

[550] and a layer with a large wavelength dispersion and a negative Rth

[550] can be cited. In this case, each layer can be a coating layer, a cast film layer, or a combination of both. A liquid crystal orientation fixing layer or a curing layer can also be included.

[0215] The Re

[550] of the second protective film 52a can be 3 nm or less, or 1 nm or less. The Rth

[550] of the second protective film 52a can be 3 nm or less, or 0 nm or less. The Rth

[450] of the second protective film 52a can be -5 nm or less, or -10 nm or less, or -25 nm or more, or -20 nm or more.

[0216] Regarding the second protective film 52b used in the second polarizing plate, the same protective film as the above-mentioned first protective film 32 can be used. In addition, the adhesive for bonding each layer, the binder, and the manufacturing method of the polarizing plate can also adopt the same substances and methods as those of the above-mentioned first polarizing plate 10.

[0217] [Liquid Crystal Display Panel]

[0218] The liquid crystal display panel of the present invention can be manufactured by disposing the first polarizing plate 10 on one surface of the liquid crystal cell in the IPS mode and the second polarizing plate 20 on the other surface. The liquid crystal cell in the IPS mode includes a liquid crystal layer containing liquid crystal molecules that are uniformly oriented in the absence of an electric field. The liquid crystal display panel of the present invention can be used in either the E mode or the O mode. In either mode, it is arranged such that the initial orientation direction of the liquid crystal cell is parallel to the absorption axis direction of the second polarizing plate 51.

[0219] In addition, as Figure 2As shown, the direction of the absorption axis (refer to the arrow) of the first polarizer 31 is orthogonal to the direction of the absorption axis (refer to the arrow) of the second polarizer 51.

[0220] A brightness enhancement film can also be placed between the LCD panel and the light source. The brightness enhancement film can be integrated with the polarizing plate on the light source side.

[0221] Example

[0222] The following examples illustrate the invention in more detail, but the invention is not limited to these examples. In the examples, parts and percentages representing content or usage are used as mass references unless otherwise specified. Furthermore, regarding angles, counterclockwise direction is considered positive.

[0223] <Preparation of Protective Film>

[0224] The following protective film has been prepared.

[0225] • Protective film E1: Triacetyl cellulose membrane with hard coating after saponification treatment (manufactured by Toppan Printing Co., Ltd., trade name "40FJCHCN-LMP", triacetyl cellulose membrane thickness: 40μm, hard coating thickness: 7μm).

[0226] • Protective film E2: A stacked phase retardation film as described in paragraph

[0147] of International Publication No. 2022 / 158482. This stacked phase retardation film comprises a liquid crystal layer and a cyclic olefin polymer film. The liquid crystal layer corresponds to the positive C plate 42. The cyclic olefin polymer film corresponds to the positive A plate 41.

[0227] The values ​​of Re

[480] and Re

[590] of the protective film E2 are 123.3 nm and 122.0 nm, respectively, and the ratio of Re

[480] to Re

[590] is 1.01. The protective film E2 satisfies equations (1) to (3).

[0228] <Making of Protective Film>

[0229] (Protective film A)

[0230] In this embodiment, the protective film A is composed of three layers: a cellulose acylate film, an alignment film, and a rod-shaped liquid crystal vertical alignment immobilization layer.

[0231] A commercially available cellulose acylated membrane TD80UL (manufactured by Fujifilm Corporation: 80 μm thickness) was immersed in a 1.5 mol / L NaOH aqueous solution (saponification solution) maintained at 55°C for 2 minutes, followed by washing with water. Then, it was immersed in a 0.05 mol / L sulfuric acid aqueous solution at 25°C for 30 seconds, and further washed with running water for 30 seconds to neutralize the membrane. After removing water by repeating this process three times using an air knife, the membrane was dried in a drying zone at 70°C for 15 seconds, thus producing a saponified membrane.

[0232] Next, referring to

[0320] to

[0328] of Japanese Patent Application Publication No. 2007-155972, a PVA-based alignment film and an optically anisotropic layer on which rod-shaped liquid crystals were vertically aligned were formed.

[0233] (Fabrication of the first optical anisotropy layer)

[0234] On one side of the cellulose acylated membrane prepared above, an alignment film coating solution with the following composition was continuously coated using a #14 wire rod. The membrane was dried with warm air at 60°C for 60 seconds, and then further dried with warm air at 100°C for 120 seconds to form an alignment film.

[0235] Composition of the orientation film coating solution

[0236] --------------------------

[0237] The following modified polyvinyl alcohol: 10 parts by weight

[0238] Water: 371 parts by weight

[0239] Methanol: 119 parts by weight

[0240] Glutaraldehyde: 0.5 parts by weight

[0241] --------------------------

[0242] [Chemical Formula 1]

[0243]

[0244] Regarding the coating solution containing the rod-shaped liquid crystal compound with the following composition, the film thickness was adjusted on the alignment film prepared above with Rth

[550] set to -55 nm. The solvent was dried in a process of continuously heating from room temperature to 80°C. Then, the rod-shaped liquid crystal compound was oriented by heating at 80°C for 90 seconds. Next, the film temperature was maintained at 60°C, and the orientation of the liquid crystal compound was fixed by UV irradiation to form an optically anisotropic layer.

[0245] Composition of coating liquid containing rod-shaped liquid crystal compounds

[0246] ----------------------------------

[0247] The following rod-shaped liquid crystal compound (I): 100 parts by mass

[0248] Photopolymerization initiator (Irgacure 907, manufactured by Ciba-Geigy): 3 parts by weight

[0249] Sensitizer (KAYACURE DETX, manufactured by Nippon Kayaku Co., Ltd.): 1 part by weight

[0250] The following fluoropolymers: 0.4 parts by weight

[0251] The following pyridinium salts: 1 part by weight

[0252] Methyl ethyl ketone: 172 parts by weight

[0253] ----------------------------------

[0254] [Chemical Formula 2]

[0255]

[0256] [Chemical Formula 3]

[0257]

[0258] [Chemical Formula 4]

[0259]

[0260] It was confirmed that an optically anisotropic layer was formed in which rod-shaped liquid crystal molecules were substantially perpendicular to the film surface.

[0261] It should be noted that the Rth at wavelengths of 450nm and 550nm and the Re at wavelength of 550nm for protective film A are shown in Table 2.

[0262] (Protective film B)

[0263] Compared to protective film A, the thickness of the cellulose acylate film was set to 40 μm, and the thickness of the rod-shaped liquid crystal vertical alignment immobilization layer was adjusted. Otherwise, protective film B was fabricated using the same procedure.

[0264] (Protective film C)

[0265] Compared to protective film A, the thickness of the cellulose acylate film was set to 20 μm, and the thickness of the rod-shaped liquid crystal vertical alignment immobilization layer was adjusted. Otherwise, protective film C was fabricated using the same procedure.

[0266] (Protective film D)

[0267] An acrylic resin film with a thickness of 40μm (manufactured by Toyo Steel Sheet Co., Ltd.: product name "HX-40NE") was used.

[0268] <Making of Polarizing Sheets>

[0269] (Example 1: Fabrication of a polarizer (1))

[0270] A 30 μm thick polyvinyl alcohol resin film was immersed in pure water at 21.5 °C for 79 seconds. It was then immersed in an aqueous solution at 23 °C containing 1.0 mM iodine in a potassium iodide / boric acid / water mass ratio of 2 / 2 / 100 for 151 seconds. Next, it was immersed in an aqueous solution at 62.0 °C in a potassium iodide / boric acid / water mass ratio of 2.5 / 4 / 100 for 76 seconds. Following this, it was immersed in an aqueous solution at 45 °C in a potassium iodide / boric acid / water mass ratio of 3 / 5.5 / 100 for 11 seconds. Finally, it was dried at 38 °C to obtain a 12 μm thick polarizer 1 formed by the adsorption and orientation of iodine in polyvinyl alcohol. Stretching was mainly performed during the dyeing and first crosslinking processes, with a total stretching ratio of 5.85 times. The orthogonal transmittance of the polarizer (1) at a wavelength of 410 nm was 0.002%. It should be noted that the thickness of the obtained polarizer was measured using a digital micrometer "MH-15M" manufactured by Nikon Corporation.

[0271] (Example 2: Fabrication of polarizer (2))

[0272] A 30 μm thick polyvinyl alcohol resin film was immersed in pure water at 21.5 °C for 79 seconds. It was then immersed in an aqueous solution at 23 °C containing 1.0 mM iodine in a potassium iodide / boric acid / water mass ratio of 2 / 2 / 100 for 151 seconds. Next, it was immersed in an aqueous solution at 62.0 °C in a potassium iodide / boric acid / water mass ratio of 2.5 / 4 / 100 for 76 seconds. Following this, it was immersed in an aqueous solution at 45 °C in a potassium iodide / boric acid / water mass ratio of 0.5 / 5.5 / 100 for 11 seconds. Finally, it was dried at 38 °C to obtain a 12 μm thick polarizer 2 formed by the adsorption and orientation of iodine in polyvinyl alcohol. Stretching was mainly performed during the dyeing and first crosslinking processes, with a total stretching ratio of 5.85 times. The orthogonal transmittance of the polarizer (2) at a wavelength of 410 nm was 0.060%. It should be noted that the thickness of the aforementioned polarizer 1, etc., was measured using a digital micrometer "MH-15M" manufactured by Nikon Corporation.

[0273] <Preparation of Adhesive Compositions>

[0274] (Manufacturing Example 3: Preparation of adhesive composition (1))

[0275] 50g of a modified polyvinyl alcohol resin containing acetyl groups (manufactured by Mitsubishi Chemical Co., Ltd.: GOHSENX Z-410) was dissolved in 950g of pure water, heated at 90°C for 2 hours, and then cooled to room temperature to obtain an acetyl group modified polyvinyl alcohol resin solution.

[0276] In the obtained acetoacetyl-modified polyvinyl alcohol resin solution, a 40% by mass solution of glyoxal, maleic acid, and pure water were combined in the amounts shown in Table 1 below to prepare an adhesive composition (1). It should be noted that Table 1 refers to the parts by mass of each component relative to 100 parts by mass of the adhesive composition.

[0277] [Table 1]

[0278]

[0279] <Preparation of Adhesive Layer>

[0280] The following adhesive layers were prepared.

[0281] • Adhesive layer A: A commercially available sheet of acrylic adhesive with 38μm PET on both sides, containing a release agent. The adhesive layer has a thickness of 5μm and a storage modulus of 0.14MPa.

[0282] • Adhesive layer B: A commercially available sheet of acrylic adhesive with 38μm PET backing and release agent on both sides. The adhesive layer is 25μm thick and has a storage modulus of 0.06MPa.

[0283] <Making of Polarizing Plates>

[0284] (Example 4: Fabrication of the first polarizing plate (10-1))

[0285] On one side (one side) of the polarizer (1) manufactured in Manufacturing Example 1, the side without the hard coating layer of the protective film E1 is laminated with the adhesive composition (1) prepared in Manufacturing Example 3. On the other side of the polarizer (1), a protective film E2 (polarizer (30-1)) is laminated with the adhesive composition (1) prepared in Manufacturing Example 3. Furthermore, on the protective film E2 side, a protective film A is laminated with adhesive layer A and bonded using a roller laminator. At this time, the liquid crystal layer of E2 is arranged on the polarizer side with the slow axis of the positive A plate 41 substantially parallel to the absorption axis of the first polarizer 31. Furthermore, an adhesive layer B is laminated on the protective film A and dried at 75°C for 8 minutes to obtain the first polarizer (10-1). The first polarizer (10-1) has a layer structure of "polarizer (30-1) / adhesive layer A / protective film A / adhesive layer B / PET with release agent".

[0286] (Example 5: Fabrication of the first polarizing plate (10-2), (10-3), (10-5))

[0287] The protective film A of the first polarizing plate (10-1) was replaced with protective films B, C, and D to produce the first polarizing plates (10-2), (10-3), and (10-5).

[0288] (Example 6: Fabrication of the first polarizing plate (10-4))

[0289] The polarizer (1) in the polarizer (30-1) of the first polarizer (10-2) was replaced with polarizer (2) to make the first polarizer (10-4).

[0290] Protective films A to D correspond to another first protective film 32b. Polarizers (1) to (2) correspond to the first polarizer 31. The first polarizing plates (10-1) to (10-5) correspond to the first polarizing plate 10.

[0291] Table 2 shows the composition of the first polarizing plates (10-1) to (10-5). It should be noted that adhesive composition (1) and adhesive layers A and B are omitted in Table 2.

[0292] [Table 2]

[0293]

[0294] The properties of each material in the first polarizing plate (10-1) to (10-5) were determined using the following method.

[0295] <Determination of in-plane phase difference and thickness direction phase difference>

[0296] The in-plane phase difference (Re) and thickness direction phase difference (Rth) at various wavelengths were measured using a phase difference meter "KOBRA (registered trademark)-WPR" manufactured by Oji Measurement Equipment Co., Ltd., which is based on the parallel Nicol rotation method, at a temperature of 23°C, to investigate wavelength dispersion.

[0297] <Determination of the cross-transmittance of a polarizer at a wavelength of 410 nm>

[0298] The cross transmittance of polarizers (1) and (2) at a wavelength of 410 nm was measured using a spectrophotometer with an integrating sphere ("V7100" manufactured by Nippon Spectrophotometer Co., Ltd., 2-degree field of view; C light source).

[0299] <Making of Polarizing Plates>

[0300] (Example 7: Fabrication of the second polarizing plate (20-1))

[0301] On one side of the polarizer (1) manufactured in Manufacturing Example 1, a protective film D is laminated using the adhesive composition (1) prepared in Manufacturing Example 3, and then laminated using a roller laminator. On the other side of the polarizer (1), the side of the protective film E1 without the hard coating layer is laminated using the adhesive composition (1) prepared in Manufacturing Example 3. Then, it is dried at 75°C for 8 minutes to obtain the second polarizer (20-1). It should be noted that the thickness of the adhesive layer formed by the adhesive composition (1) after drying is 80 nm. Protective film D corresponds to one second protective film 52a. Protective film E1 corresponds to another second protective film 52b. Polarizer (1) corresponds to the second polarizer 51. The second polarizer (20-1) corresponds to the second polarizer 20.

[0302] The configuration of the second polarizing plate (20-1) is shown in Table 3.

[0303] [Table 3]

[0304]

[0305] <Evaluation of Polarizing Plate Assembly>

[0306] The Pioneer AVIC-RZ120 car navigation system was disassembled, and the upper and lower polarizing plates of the liquid crystal cell (60-1) were peeled off. This liquid crystal cell (60-1) is an IPS-type liquid crystal cell. The polarizing plates obtained in Examples 4 to 7 were prepared to replace the original polarizing plates. The protective film A to D sides of the first polarizing plate 10 and the protective film D side of the second polarizing plate 20 were bonded to the liquid crystal cell (60-1) using a pressure-sensitive adhesive. That is, the first polarizing plates (10-1) to (10-5) were bonded to the viewing side, and the second polarizing plate (20-1) was bonded to the TFT side.

[0307] <Evaluation of visual contrast>

[0308] After reassembling the car navigation system and turning on the backlight, the contrast ratio at azimuth angle θ42.4° / elevation angle φ23.4° was measured using an ELDIM EZCONTRAST 160R LCD viewing angle measuring device. The viewing angle contrast ratio was evaluated according to the following benchmarks. The results are shown in Table 4.

[0309] It should be noted that, according to the polarizing plate assembly of the present invention, the contrast can also be improved, for example, at an azimuth angle of θ42.4° and an elevation angle of φ156.6°, in addition to the specified viewing angles mentioned above.

[0310] • Evaluation criteria for viewing angle contrast

[0311] 2A (Exceptionally Excellent): Viewing angle contrast ratio of 750 or higher

[0312] A (Excellent): Viewing contrast ratio is above 700 and below 750.

[0313] B (Good): Viewing contrast ratio is above 650 and below 700.

[0314] C (Acceptable): Viewing contrast ratio is above 600 and below 650.

[0315] D (Not allowed): Viewing contrast ratio less than 600

[0316] [Table 4]

[0317]

Claims

1. A polarizing plate set for respectively bonding to both faces of a liquid crystal cell provided with a liquid crystal layer containing liquid crystal molecules that are uniformly oriented in the absence of an electric field, the polarizing plate set having a first polarizing plate disposed on one face of the liquid crystal cell and a second polarizing plate disposed on the other face of the liquid crystal cell, the first polarizing plate having a first polarizing sheet, a phase difference layer, and a first protective film, the phase difference layer being disposed between the liquid crystal cell and the first polarizing sheet, the phase difference layer satisfying the following formulas (1) to (3), ny[590] < nz[590] < nx[590] (1) 0.8 < Re[480] / Re[590] < 1.2 (2) 100 nm < Re[590] < 150 nm (3) the first protective film satisfying the following formulas (4) to (6), 0 nm < Re[550] < 5 nm (4) -5 nm < Rth[550] < 5 nm (5) -30 nm < Rth[450] < -1.0 nm (6) the second polarizing plate having a second polarizing sheet and a second protective film, the second protective film being disposed between the liquid crystal cell and the second polarizing sheet, the second protective film satisfying the following formulas (7) and (8), 0 nm < Re[550] < 5 nm (7) -5 nm < Rth[550] < 5 nm (8) the slow axis of the phase difference layer is substantially parallel or substantially orthogonal to the absorption axis of the first polarizing sheet. The orthogonal transmittance at a wavelength of 410 nm of the first polarizing sheet and the second polarizing sheet is 0.05% or less. The second protective film further satisfies the following formula (9), -30 nm < Rth[450] < -1.0 nm (9). The phase difference layer has a positive A-plate and a positive C-plate.

5. A liquid crystal panel having:

2. The polarizing plate set according to claim 1, wherein a liquid crystal cell provided with a liquid crystal layer containing liquid crystal molecules that are uniformly oriented in the absence of an electric field; 3. The polarizing plate set according to claim 1 or 2, wherein a first polarizing plate disposed on one face of the liquid crystal cell; and a second polarizing plate disposed on the other face of the liquid crystal cell, 4. The polarizing plate set according to claim 1 or 2, wherein the first polarizing plate having a first polarizing sheet, a phase difference layer, and a first protective film, the phase difference layer being disposed between the liquid crystal cell and the first polarizing sheet, the phase difference layer satisfying the following formulas (1) to (3), ny[590] < nz[590] < nx[590] (1) 0.8 < Re[480] / Re[590] < 1.2 (2) 100 nm < Re[590] < 150 nm (3) the first protective film satisfying the following formulas (4) to (6), 0 nm < Re[550] < 5 nm (4) -5 nm < Rth[550] < 5 nm (5) -30 nm < Rth[450] < -1.0 nm (6) the second polarizing plate having a second polarizing sheet and a second protective film, the second protective film being disposed between the liquid crystal cell and the second polarizing sheet, the second protective film satisfying the following formulas (7) and (8), 0 nm < Re[550] < 5 nm (7) -5 nm < Rth[550] < 5 nm (8) ​ ​ ​ ​ ​ ​ ​ ​ 0 nm < Re[550] < 5 nm (7) -5 nm < Rth[550] < 5 nm (8) the slow axis of the phase difference layer is substantially parallel or substantially orthogonal to the absorption axis of the first polarizing plate, the absorption axis of the first polarizing plate is substantially orthogonal to the absorption axis of the second polarizing plate.

6. The liquid crystal panel of claim 5, wherein, the second protective film also satisfies the following formula (9), -30 nm < Rth[450] < -1.0 nm (9).

7. The liquid crystal panel according to claim 5 or 6, wherein the orthogonal transmittance at a wavelength of 410 nm of the first polarizing plate and the second polarizing plate is 0.05% or less.

8. The liquid crystal panel according to claim 5 or 6, wherein the phase difference layer has a positive A-plate and a positive C-plate.

Images