JP4761299B2 - Liquid crystal panel and liquid crystal display device - Google Patents

Description

  The present invention relates to a liquid crystal panel and a liquid crystal display device. More specifically, the present invention relates to a liquid crystal panel and a liquid crystal display device having excellent screen contrast and small color shift without adding complicated means.

  In the VA mode or OCB mode liquid crystal cell, the liquid crystal is aligned in the vertical direction. Therefore, when the liquid crystal panel is viewed from an oblique direction, the apparent liquid crystal is aligned in the oblique direction, and the polarization state of the light from the oblique direction is changed by the birefringence of the liquid crystal, and the polarizing plate The light leaks from.

  A polarizing plate blocks light by arranging it so that its absorption axes are orthogonal, but when the polarizing plate in such a laminated state is viewed from an oblique direction, the absorption axis of the apparent polarizing plate is non-orthogonal. In this state, light leakage from the polarizing plate occurs.

Therefore, a biaxial optical compensator satisfying the relationship of nx>ny> nz (nx is the refractive index in the slow axis direction, ny is the refractive index in the fast axis direction, and nz is the refractive index in the thickness direction) is used. There have been reports of techniques for compensating for the effects of liquid crystal birefringence and polarizing axis misalignment on light leakage (see Patent Documents 1 to 4). However, it does not satisfy both the improvement of the screen contrast and the reduction of the color shift.
JP 2003-270442 A JP 2003-315555 A JP 2004-4550 A JP 2005-77853 A

  The present invention has been made in order to solve the above-described conventional problems. The object of the present invention is to provide a liquid crystal panel and a liquid crystal display having excellent screen contrast and small color shift without adding complicated means. To provide an apparatus.

The liquid crystal panel of the present invention includes a first polarizer, a first optical compensation layer, a liquid crystal cell, a second optical compensation layer, and a second polarizer in this order, and the first optical compensation layer includes Formula (1) and Formula (2) are satisfied, the second optical compensation layer satisfies Formula (1) and Formula (3), and the slow axis of the first optical compensation layer is the first polarizer The slow axis of the second optical compensation layer is orthogonal to the absorption axis of the second polarizer:
nx>ny> nz (1)
2 ≦ (nx−nz) / (nx−ny) ≦ 20 (2)
0.97 <Δnd (x) / Δnd (590) <1.05 (3)
nx is the refractive index in the slow axis direction, ny is the refractive index in the fast axis direction, nz is the refractive index in the thickness direction, and Δnd (x) is an in-plane measured with light of wavelength x (450 nm ≦ x ≦ 700 nm). The phase difference value, Δnd (590), indicates an in-plane phase difference value measured with light having a wavelength of 590 nm.

  In a preferred embodiment, the first polarizer and the first optical compensation layer are disposed on the backlight side of the liquid crystal cell.

  In a preferred embodiment, the material constituting the optical compensation layer is at least one non-liquid crystalline material selected from the group consisting of polyamide, polyimide, polyester, polyetherketone, polyamideimide, and polyesterimide.

  In a preferred embodiment, the liquid crystal cell is in a VA mode or an OCB mode.

  According to another aspect of the present invention, a liquid crystal display device is provided. The liquid crystal display device of the present invention includes the liquid crystal panel.

  According to the present invention, it is possible to provide a liquid crystal panel and a liquid crystal display device that are excellent in screen contrast and have a small color shift without adding complicated means. Such an effect is obtained by arranging a specific first optical compensation layer and a first polarizer on one side of the liquid crystal cell so that the slow axis of the former is parallel to the absorption axis of the latter. It becomes conspicuous by arranging a specific second optical compensation layer and a second polarizer on the other side so that the former slow axis is perpendicular to the latter absorption axis to form a liquid crystal panel.

A. Configuration of Liquid Crystal Panel and Liquid Crystal Display Device Including the Same FIG. 1 is a schematic cross-sectional view illustrating a preferred example of a liquid crystal panel 100 of the present invention. The liquid crystal panel 100 includes a first polarizer 30, a first optical compensation layer 60, a liquid crystal cell 40, a second optical compensation layer 70, and a second polarizer 50 in this order. Practically, any appropriate protective film (not shown) may be provided on at least one side of the first polarizer 30 and at least one side of the second polarizer 50. A polarizer provided with a protective film on at least one side may be referred to as a polarizing plate. The first polarizer and the first optical compensation layer may be arranged on the viewing side or the backlight side of the liquid crystal cell, but are preferably arranged on the backlight side. .

  The slow axis of the first optical compensation layer is parallel to the absorption axis of the first polarizer. The slow axis of the second optical compensation layer is orthogonal to the absorption axis of the second polarizer. In order to have such a relationship, the first polarizer 30, the first optical compensation layer 60, the liquid crystal cell 40, the second optical compensation layer 70, and the second polarizer 50 are arranged as described above. Accordingly, it is possible to provide a liquid crystal panel and a liquid crystal display device that have excellent screen contrast and a small color shift.

  The liquid crystal cell 40 has a pair of glass substrates 41 and 42 and a liquid crystal layer 43 as a display medium disposed between the substrates. One substrate (active matrix substrate) 41 includes a switching element (typically a TFT) for controlling the electro-optical characteristics of the liquid crystal, and a scanning line for supplying a gate signal to the active element and a signal line for supplying a source signal. Provided (none shown). The other glass substrate (color filter substrate) 42 is provided with a color filter (not shown). The color filter may be provided on the active matrix substrate 41. A distance (cell gap) between the substrates 41 and 42 is controlled by a spacer 44. An alignment film (not shown) made of polyimide, for example, is provided on the side of the substrates 41 and 42 in contact with the liquid crystal layer 43.

  As a driving mode of the liquid crystal cell 40, any appropriate driving mode can be adopted as long as the effect of the present invention can be obtained. Specific examples of the drive mode include STN (Super Twisted Nematic) mode, TN (Twisted Nematic) mode, IPS (In-Plane Switching) mode, VA (Vertical Aligned Hidden Alignment mode), OCB (Optically Aligned Hiely mode) Examples include an aligned nematic (ASM) mode and an ASM (axially aligned microcell) mode. VA mode and OCB mode are preferred. This is because the color shift is remarkably improved.

  FIG. 2 is a schematic cross-sectional view illustrating the alignment state of liquid crystal molecules in the VA mode. As shown in FIG. 2A, the liquid crystal molecules are aligned perpendicular to the surfaces of the substrates 41 and 42 when no voltage is applied. Such vertical alignment can be realized by arranging a nematic liquid crystal having negative dielectric anisotropy between substrates on which a vertical alignment film (not shown) is formed. When light is incident from the surface of one substrate 41 in this state, the linearly polarized light that has passed through the first polarizer 30 and entered the liquid crystal layer 43 is the major axis of vertically aligned liquid crystal molecules. Proceed along the direction of Since birefringence does not occur in the major axis direction of the liquid crystal molecules, incident light travels without changing the polarization direction and is absorbed by the second polarizer 50 having a polarization axis orthogonal to the first polarizer 30. This provides a dark display when no voltage is applied (normally black mode). As shown in FIG. 2B, when a voltage is applied between the electrodes, the major axis of the liquid crystal molecules is aligned parallel to the substrate surface. Liquid crystal molecules exhibit birefringence with respect to linearly polarized light incident on the liquid crystal layer 43 in this state, and the polarization state of incident light changes according to the inclination of the liquid crystal molecules. Light that passes through the liquid crystal layer when a predetermined maximum voltage is applied becomes, for example, linearly polarized light whose polarization direction is rotated by 90 °, and therefore passes through the second polarizer 50 to obtain a bright display. When the voltage is not applied again, the display can be returned to the dark state by the orientation regulating force. In addition, gradation display can be performed by changing the intensity of transmitted light from the second polarizer 50 by changing the applied voltage to control the tilt of the liquid crystal molecules.

  FIG. 3 is a schematic cross-sectional view illustrating the alignment state of liquid crystal molecules in the OCB mode. The OCB mode is a driving mode in which the liquid crystal layer 43 is configured by so-called bend alignment. As shown in FIG. 3C, the bend alignment has a substantially parallel angle (alignment angle) when the alignment of nematic liquid crystal molecules is in the vicinity of the substrate, and the alignment plane increases toward the center of the liquid crystal layer. An alignment state that exhibits an angle perpendicular to the liquid crystal layer, gradually changes so as to be aligned with the opposing substrate surface as the distance from the center of the liquid crystal layer, and does not have a twisted structure throughout the liquid crystal layer. Such a bend orientation is formed as follows. As shown in FIG. 3A, in a state where no electric field or the like is applied (initial state), the liquid crystal molecules are substantially homogeneously aligned. However, the liquid crystal molecules have a pretilt angle, and the pretilt angle near the substrate is different from the pretilt angle near the opposite substrate. When a predetermined bias voltage (typically 1.5 V to 1.9 V) is applied here (when a low voltage is applied), a splay orientation as shown in FIG. A transition to bend orientation as shown can be achieved. When a display voltage (typically 5 V to 7 V) is applied from the bend alignment state (when a high voltage is applied), the liquid crystal molecules rise substantially perpendicular to the substrate surface as shown in FIG. In the normally white display mode, the light that has passed through the first polarizer 30 and entered the liquid crystal layer in the state of FIG. 3D when a high voltage is applied proceeds without changing the polarization direction. 2 is absorbed by the second polarizer 50. Therefore, a dark state is displayed. When the display voltage is lowered, it can return to the bend alignment and return to the bright display by the alignment regulating force of the rubbing process. In addition, gradation display is possible by changing the display voltage to control the tilt of the liquid crystal molecules to change the transmitted light intensity from the polarizer. Note that a liquid crystal display device having an OCB mode liquid crystal cell can switch the phase transition from the splay alignment state to the bend alignment state at a very high speed, so that the liquid crystal display device in other drive modes such as the TN mode and the IPS mode is used. In comparison, it has a feature of excellent moving image display characteristics.

  The OCB mode liquid crystal cell display mode can be used in either a normally white mode that takes a dark state (black display) when a high voltage is applied or a normally black mode that takes a bright state (white display) when a high voltage is applied. can do.

  The cell gap of the OCB mode liquid crystal cell is preferably 2 μm to 10 μm, more preferably 3 μm to 9 μm, and particularly preferably 4 μm to 8 μm. Within the above range, the response time can be shortened and good display characteristics can be obtained.

The nematic liquid crystal used in the OCB mode liquid crystal cell preferably has a positive dielectric anisotropy. Specific examples of nematic liquid crystals having positive dielectric anisotropy include those described in JP-A-9-176645. A commercially available nematic liquid crystal may be used as it is. Examples of the commercially available nematic liquid crystal include a product name “ZLI-4535” and a product name “ZLI-1132” manufactured by Merck. The difference between the ordinary refractive index (no) and the extraordinary refractive index (ne) of the nematic liquid crystal, that is, the birefringence (Δn _LC ) is appropriately selected depending on the response speed, transmittance, etc. of the liquid crystal. Is 0.05-0.30, more preferably 0.10-0.30, and still more preferably 0.12-0.30. Further, the pretilt angle of such nematic liquid crystal is preferably 1 ° to 10 °, more preferably 2 ° to 8 °, and particularly preferably 3 ° to 6 °. Within the above range, the response time can be shortened and good display characteristics can be obtained.

  The liquid crystal panel as described above is suitably used for liquid crystal display devices such as personal computers, liquid crystal televisions, mobile phones, personal digital assistants (PDAs), and projectors.

B. Polarizer The polarizers in the present invention (the first polarizer 30 and the second polarizer 50) are formed from a polyvinyl alcohol-based resin. As the polarizer in the present invention, a polyvinyl alcohol resin film dyed with a dichroic substance (typically iodine or a dichroic dye) and uniaxially stretched is preferably used. The polymerization degree of the polyvinyl alcohol resin constituting the polyvinyl alcohol resin film is preferably 100 to 5000, and more preferably 1400 to 4000. The polyvinyl alcohol-based resin film constituting the polarizer can be formed by any suitable method (for example, a casting method in which a solution obtained by dissolving a resin in water or an organic solvent is cast, a casting method, an extrusion method). . The thickness of the polarizer can be appropriately set according to the purpose and application of the liquid crystal display device or image display device used, but is preferably 5 to 80 μm.

  As a manufacturing method of a polarizer, the method of using the said polyvinyl alcohol-type resin film for the manufacturing process including a dyeing process, a bridge | crosslinking process, an extending | stretching process, a washing | cleaning process, and a drying process is employ | adopted. In each processing step except the drying step, the treatment is performed by immersing the polyvinyl alcohol-based resin film in a bath containing a solution used in each step. The order, number of times, and the presence / absence of each process of the dyeing process, the crosslinking process, the stretching process, the washing process, and the drying process can be appropriately set according to the purpose, materials used, conditions, and the like. For example, several processes may be performed simultaneously in one process, and a specific process may be omitted. More specifically, for example, the stretching process may be performed after the dyeing process, may be performed before the dyeing process, or may be performed simultaneously with the dyeing process and the crosslinking process. Further, for example, it can be suitably employed to perform the crosslinking treatment before and after the stretching treatment. Further, for example, the cleaning process may be performed after all the processes, or may be performed only after a specific process. Particularly preferably, the dyeing step, the crosslinking step, the stretching step, the washing step, and the drying step are performed in this order. Moreover, it is also a preferable aspect to perform a swelling process before a dyeing process.

(Swelling process)
The swelling step is a step of swelling the polyvinyl alcohol-based resin film. Typically, it is performed by immersing the polyvinyl alcohol resin film in a treatment bath (swelling bath) filled with water. By this treatment, dirt on the surface of the polyvinyl alcohol-based resin film and an anti-blocking agent can be washed, and unevenness such as uneven dyeing can be prevented by swelling the polyvinyl alcohol-based resin film. Glycerin, potassium iodide, or the like can be appropriately added to the swelling bath. The temperature of the swelling bath is preferably 20 to 60 ° C., more preferably 20 to 50 ° C., and the immersion time in the swelling bath is preferably 0.1 to 10 minutes, more preferably 1 to 7 minutes. In addition, since a polyvinyl alcohol-type resin film can also be swollen in the dyeing process mentioned later, this swelling process can also be abbreviate | omitted.

  When pulling up the film from the swelling bath, any appropriate liquid break roll such as a pinch roll may be used as necessary to prevent the occurrence of dripping, or the liquid may be removed with an air knife. Excess water may be removed by a method such as scraping off.

(Dyeing process)
The dyeing step is typically performed by immersing the polyvinyl alcohol resin film in a treatment bath (dye bath) containing a dichroic substance such as iodine (sometimes referred to as adsorption or contact). Done. As the solvent used for the dye bath solution, water is generally used, but an appropriate amount of an organic solvent compatible with water may be added. The dichroic substance is used in a proportion of preferably 0.01 to 10 parts by weight, more preferably 0.02 to 7 parts by weight, and still more preferably 0.025 to 5 parts by weight with respect to 100 parts by weight of the solvent. .

  Any appropriate substance suitable for the present invention can be used as the dichroic substance, and examples thereof include iodine and organic dyes. Organic dyes include, for example, Red BR, Red LR, Red R, Pink LB, Rubin BL, Bordeaux GS, Sky Blue LG, Lemon Yellow, Blue BR, Blue 2R, Navy RY, Green LG, Violet LB, Violet B, Black H, Black B, Black GSP, Yellow 3G, Yellow R, Orange LR, Orange 3R, Scarlet GL, Scarlet KGL, Congo Red, Brilliant Violet BK, Spura Blue G, Spura Blue GL, Spura Orange GL, Direct Sky Blue, Direct First orange S, first black, etc. are mentioned.

  In the dyeing step, only one kind of dichroic substance may be used, or two or more kinds may be used in combination. In the case of using an organic dye, for example, it is preferable to combine two or more kinds from the viewpoint of achieving neutralization in the visible light region. As specific examples, for example, combinations of Congo Red and Spula Blue G, Spula Orange GL and Direct Sky Blue, Direct Sky Blue and First Black, and the like can be given.

  When iodine is used as the dichroic substance, the dye bath solution preferably further contains an auxiliary agent such as iodide. This is because the dyeing efficiency is improved. Specific examples of iodide include potassium iodide, lithium iodide, sodium iodide, zinc iodide, aluminum iodide, lead iodide, copper iodide, barium iodide, calcium iodide, tin iodide, and iodide. Titanium is mentioned. Among these, potassium iodide is preferable. The auxiliary is preferably used in a proportion of 0.02 to 20 parts by weight, more preferably 0.01 to 10 parts by weight, and still more preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the solvent. The ratio (weight ratio) of iodine and auxiliary agent (preferably potassium iodide) is preferably 1: 5 to 1: 100, more preferably 1: 6 to 1:80, still more preferably 1: 7 to 1:70. It is.

  The temperature of the dyeing bath is preferably 5 to 70 ° C, more preferably 5 to 42 ° C, and still more preferably 10 to 35 ° C. The immersion time in the dyeing bath is preferably 1 to 20 minutes, more preferably 2 to 10 minutes.

  In the dyeing process, the film may be stretched in a dyeing bath. The total draw ratio accumulated at this time is preferably 1.1 to 4.0 times.

  As the dyeing process in the dyeing process, in addition to the method of immersing in the dyeing bath as described above, for example, a method of applying or spraying an aqueous solution containing a dichroic substance onto a polyvinyl alcohol resin film may be used. Moreover, it is also possible to mix a dichroic substance in advance at the time of film formation in the previous step. In this case, the pre-process and the dyeing process are performed at the same time.

  When pulling up the film from the dyeing bath, any appropriate liquid break roll such as a pinch roll may be used as necessary to prevent the occurrence of dripping, or the liquid may be removed with an air knife. Excess water may be removed by a method such as scraping off.

(Crosslinking process)
The crosslinking step is typically performed by immersing the dyed polyvinyl alcohol resin film in a treatment bath (crosslinking bath) containing a crosslinking agent. Arbitrary appropriate crosslinking agents can be employ | adopted as a crosslinking agent. Specific examples of the crosslinking agent include boron compounds such as boric acid and borax, glyoxal, and glutaraldehyde. These can be used alone or in combination. When combining two or more types, for example, a combination of boric acid and borax is preferable, and the combination ratio (molar ratio) is preferably 4: 6 to 9: 1, more preferably 5.5: 4.5. -7: 3, more preferably 5.5: 4.5-6.5-3.5.

  As the solvent used for the solution of the crosslinking bath, water is generally used, but an appropriate amount of an organic solvent having compatibility with water may be added. The crosslinking agent is typically used at a ratio of 1 to 10 parts by weight with respect to 100 parts by weight of the solvent. When the concentration of the crosslinking agent is less than 1 part by weight, sufficient optical properties cannot often be obtained. When the concentration of the crosslinking agent exceeds 10 parts by weight, the stretching force generated in the film at the time of stretching increases, and for example, the obtained polarizing plate may shrink.

  It is preferable that the solution of the crosslinking bath further contains an auxiliary agent containing potassium iodide as an essential component. This is because it is easy to obtain uniform characteristics in the plane. The concentration of the auxiliary agent is preferably 0.05 to 15% by weight, more preferably 0.1 to 10% by weight, and still more preferably 0.5 to 8% by weight. Examples of auxiliary agents other than potassium iodide include lithium iodide, sodium iodide, zinc iodide, aluminum iodide, lead iodide, copper iodide, barium iodide, calcium iodide, tin iodide, and iodide. Titanium is mentioned. Only one of these may be used, or two or more may be used in combination.

  The temperature of the crosslinking bath is preferably 20 to 70 ° C, more preferably 40 to 60 ° C. The immersion time of the film in the crosslinking bath is preferably 1 second to 15 minutes, more preferably 5 seconds to 10 minutes.

  In the cross-linking step, a method of applying or spraying a cross-linking agent-containing solution onto the film may be employed as in the dyeing step. In the crosslinking step, the film may be stretched in a crosslinking bath. The total draw ratio accumulated at this time is preferably 1.1 to 4.0 times.

  When pulling up the film from the cross-linking bath, any appropriate liquid break roll such as a pinch roll may be used as necessary in order to prevent the occurrence of dripping. Excess water may be removed by a method such as scraping off.

(Stretching process)
The stretching process is a process of stretching the polyvinyl alcohol-based resin film. The stretching process may be performed at any stage as described above. Specifically, it may be performed after the dyeing process, may be performed before the dyeing process, may be performed simultaneously with the swelling process, the dyeing process, and the crosslinking process, or may be performed after the crosslinking process.

  The cumulative draw ratio of the polyvinyl alcohol-based resin film is preferably 2 to 7 times, more preferably 5 to 7 times, and still more preferably 5 to 6.5 times. When the cumulative draw ratio is less than 2, it may be difficult to obtain a polarizing plate with a high degree of polarization. When the cumulative draw ratio exceeds 7 times, the polyvinyl alcohol-based resin film (polarizer) may be easily broken. The thickness of the stretched film is preferably 3 to 75 μm, more preferably 5 to 50 μm.

  Arbitrary appropriate methods may be employ | adopted as a specific method of extending | stretching. Examples thereof include a wet stretching method in which a polyvinyl alcohol resin film is stretched in a warm aqueous solution, and a dry stretching method in which the water-containing polyvinyl alcohol resin film is stretched in air. When the wet stretching method is adopted, the polyvinyl alcohol-based resin film is stretched at a predetermined magnification in a treatment bath (stretching bath).

  As the solution for the stretching bath, a solution containing potassium iodide in a solvent such as water or an organic solvent (for example, ethanol) is preferably used. Other than potassium iodide, for example, various metal salts, boron or zinc compounds, lithium iodide, sodium iodide, zinc iodide, aluminum iodide, lead iodide, copper iodide, barium iodide, calcium iodide , Tin iodide, and titanium iodide may be included in one or more of these. Among these, it is preferable to contain boric acid. The concentration of potassium iodide is preferably 0.05 to 15% by weight, more preferably 0.1 to 10% by weight, and still more preferably 0.5 to 8% by weight. When boric acid and potassium iodide are used in combination, the combination ratio (weight ratio) is preferably 1: 0.1 to 1: 4, more preferably 1: 0.5 to 1: 3.

  The temperature of the stretching bath is preferably 30 to 70 ° C, more preferably 40 to 67 ° C, and further preferably 50 to 62 ° C. In the case of dry stretching, 50 to 180 ° C. is preferable.

  When pulling up the film from the stretching bath, any appropriate liquid break roll such as a pinch roll may be used as necessary to prevent the occurrence of dripping, or the liquid may be removed with an air knife. Excess water may be removed by a method such as scraping off.

(Washing process)
The washing step is typically performed by immersing the polyvinyl alcohol-based resin film subjected to the above-described various treatments in a treatment bath (water washing bath). An unnecessary residue of the polyvinyl alcohol-based resin film can be washed away by the washing step. The washing bath is an aqueous solution containing potassium iodide as an essential component. Other than potassium iodide, for example, lithium iodide, sodium iodide, zinc iodide, aluminum iodide, lead iodide, copper iodide, barium iodide, calcium iodide, tin iodide, titanium iodide, One or more of these may be included. The concentration of potassium iodide is preferably 0.05 to 15% by weight, more preferably 0.1 to 10% by weight, still more preferably 3 to 8% by weight, and particularly preferably 0.5 to 8% by weight. An auxiliary agent such as zinc sulfate or zinc chloride may be added to the aqueous iodide solution.

  The temperature of the washing bath is preferably 10 to 60 ° C, more preferably 15 to 40 ° C, and further preferably 30 to 40 ° C. The immersion time is preferably 1 second to 1 minute. The cleaning step may be performed only once, or may be performed a plurality of times as necessary. When implemented several times, the kind and density | concentration of the additive contained in the washing bath used for each process can be adjusted suitably. For example, the washing step includes a step of immersing the polymer film in an aqueous potassium iodide solution (0.1 to 10% by weight, 10 to 60 ° C.) for 1 second to 1 minute, and a step of rinsing with pure water.

  When pulling up the film from the washing bath, any appropriate liquid break roll such as a pinch roll may be used as necessary in order to prevent the occurrence of dripping. Excess water may be removed by a method such as scraping off.

(Drying process)
Any appropriate drying method (for example, natural drying, air drying, heat drying, etc.) can be adopted as the drying step. Heat drying is preferred. In the case of heat drying, the drying temperature is preferably 20 to 80 ° C, more preferably 20 to 60 ° C, still more preferably 20 to 45 ° C, and the drying time is preferably 1 to 10 minutes. A polarizer is obtained as described above.

B. As described above, practically, a protective film can be provided on at least one side of the first polarizer 30 and at least one side of the second polarizer 50. By providing the protective film, deterioration of the polarizer can be prevented.

  Any appropriate protective film can be adopted as the protective film. Examples of the material constituting the protective film include thermoplastic resins that are excellent in transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, and the like. Specific examples of such thermoplastic resins include acetate resins such as triacetyl cellulose (TAC), polyester resins, polyether sulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, acrylic resins, poly Examples include norbornene resin, cellulose resin, polyarylate resin, polystyrene resin, polyvinyl alcohol resin, polyacrylic resin, and mixtures thereof. Also, thermosetting resins such as acrylic, urethane, acrylic urethane, epoxy, and silicone, or ultraviolet curable resins may be used. From the viewpoint of polarization characteristics and durability, a TAC film whose surface is saponified with alkali or the like is preferable.

  Furthermore, for example, a polymer film formed from a resin composition as described in JP-A-2001-343529 (WO 01/37007) can also be used as a protective film. More specifically, it is a mixture of a thermoplastic resin having a substituted imide group or an unsubstituted imide group in the side chain and a thermoplastic resin having a substituted phenyl group or an unsubstituted phenyl group and a cyano group in the side chain. Specific examples include a resin composition having an alternating copolymer composed of isobutene and N-methylenemaleimide and an acrylonitrile / styrene copolymer. For example, an extruded product of such a resin composition can be used.

  The protective film is preferably transparent and not colored. Specifically, the thickness direction retardation Rth of the protective film is preferably −90 nm to +75 nm, more preferably −80 nm to +60 nm, and most preferably −70 nm to +45 nm. When the retardation Rth in the thickness direction of the protective film is within such a range, the optical coloring of the polarizer caused by the protective film can be eliminated.

  The thickness of the protective film can be appropriately set according to the purpose. The thickness of the protective film is typically 500 μm or less, preferably 5 to 300 μm, and more preferably 5 to 150 μm.

C. First Optical Compensation Layer The first optical compensation layer has a refractive index distribution represented by the formula (1):
nx>ny> nz (1).
Here, nx represents the refractive index in the slow axis direction, ny represents the refractive index in the fast axis direction, and nz represents the refractive index in the thickness direction. The slow axis refers to the direction in which the in-plane refractive index is maximized, and the fast axis refers to the direction perpendicular to the slow axis in the plane.

The first optical compensation layer satisfies formula (2):
2 ≦ (nx−nz) / (nx−ny) ≦ 20 (2).
Here, nx represents the refractive index in the slow axis direction, ny represents the refractive index in the fast axis direction, and nz represents the refractive index in the thickness direction. The slow axis refers to the direction in which the in-plane refractive index is maximized, and the fast axis refers to the direction perpendicular to the slow axis in the plane.

  (Nx−nz) / (nx−ny) may be referred to as an Nz coefficient. That is, the first optical compensation layer satisfies 2 ≦ Nz ≦ 20.

  The Nz coefficient of the first optical compensation layer can be optimized corresponding to the display mode of the liquid crystal cell.

  The Nz coefficient is preferably 2 ≦ Nz ≦ 10, more preferably 2 ≦ Nz ≦ 8, and further preferably 2 ≦ Nz ≦ 6.

  When the liquid crystal cell adopts the VA mode, the Nz coefficient is preferably 2 ≦ Nz ≦ 10, more preferably 2 ≦ Nz ≦ 8, and further preferably 2 ≦ Nz ≦ 6.

  When the liquid crystal cell adopts the OCB mode, the Nz coefficient is preferably 2 ≦ Nz ≦ 20, more preferably 2 ≦ Nz ≦ 10, and further preferably 2 ≦ Nz ≦ 8.

  The film in-plane retardation (front retardation) Δnd of the first optical compensation layer can be optimized corresponding to the display mode of the liquid crystal cell. The in-plane phase difference (front phase difference) Δnd is obtained by the formula: Δnd = (nx−ny) × d. Here, nx is the refractive index in the slow axis direction, ny is the refractive index in the fast axis direction, and d (nm) is the thickness of the birefringent layer. Typically, Δnd is measured using light having a wavelength of 590 nm.

  The lower limit of Δnd is preferably 5 nm or more, more preferably 10 nm or more, and most preferably 15 nm or more. When Δnd is less than 5 nm, the contrast in the oblique direction often decreases. On the other hand, the upper limit of Δnd is preferably 400 nm or less, more preferably 300 nm or less, further preferably 200 nm or less, particularly preferably 150 nm or less, particularly preferably 100 nm or less, and most preferably 80 nm or less. When Δnd exceeds 400 nm, the viewing angle often decreases. More specifically, when the liquid crystal cell adopts the VA mode, Δnd is preferably 5 to 150 nm, more preferably 10 to 100 nm, and most preferably 15 to 80 nm. When the liquid crystal cell adopts the OCB mode, Δnd is preferably 5 to 400 nm, more preferably 10 to 300 nm, and most preferably 15 to 200 nm.

  The thickness direction retardation Rth of the first optical compensation layer can be optimized corresponding to the display mode of the liquid crystal cell. Rth is determined by the formula: Rth = (nx−nz) × d. Typically, Rth is measured using light having a wavelength of 590 nm.

  The lower limit of Rth is preferably 10 nm or more, more preferably 20 nm or more, and most preferably 50 nm or more. When Rth is less than 10 nm, the contrast in the oblique direction often decreases. On the other hand, the upper limit of Rth is preferably 1000 nm or less, more preferably 500 nm or less, further preferably 400 nm or less, particularly preferably 300 nm or less, particularly preferably 280 nm or less, and most preferably 260 nm or less. If Rth exceeds 1000 nm, the optical compensation becomes too large, and as a result, the contrast in the oblique direction may be lowered.

  When the liquid crystal cell adopts the VA mode, Rth is preferably 10 to 300 nm, more preferably 20 to 280 nm, and most preferably 50 to 260 nm.

  When the liquid crystal cell adopts the OCB mode, Rth is preferably 10 to 1000 nm, more preferably 20 to 500 nm, and most preferably 50 to 400 nm.

  The first optical compensation layer may be a single layer or a laminate of two or more layers. In the case of a laminate, the material constituting each layer and the thickness of each layer can be appropriately set as long as the entire laminate has the optical characteristics as described above.

  As the thickness of the first optical compensation layer, any appropriate thickness can be adopted as long as the effects of the present invention are exhibited. Typically, the thickness of the first optical compensation layer is preferably 0.1 to 50 μm, more preferably 0.5 to 30 μm, and further preferably 1 to 20 μm. This is because an optical compensation layer that can contribute to thinning of the liquid crystal display device and has excellent viewing angle compensation performance and a uniform phase difference can be obtained.

  As a material constituting the first optical compensation layer, any appropriate material can be adopted as long as the above optical characteristics can be obtained. For example, such a material includes a non-liquid crystalline material. Particularly preferred are non-liquid crystalline polymers. Such a non-liquid crystal material, unlike the liquid crystal material, can form a film exhibiting optical uniaxial properties of nx> nz and ny> nz depending on its own properties regardless of the orientation of the substrate. As a result, not only an oriented substrate but also an unoriented substrate can be used. Furthermore, even when an unoriented substrate is used, the step of applying an alignment film on the surface, the step of laminating the alignment film, and the like can be omitted.

  As the non-liquid crystalline material, for example, polymers such as polyamide, polyimide, polyester, polyetherketone, polyamideimide, and polyesterimide are preferable because they are excellent in heat resistance, chemical resistance, transparency, and rich in rigidity. Any one of these polymers may be used alone, or a mixture of two or more having different functional groups such as a mixture of polyaryletherketone and polyamide may be used. . Among such polymers, polyimide is particularly preferable because of its high transparency, high orientation, and high stretchability.

  The molecular weight of the polymer is not particularly limited. For example, the weight average molecular weight (Mw) is preferably in the range of 1,000 to 1,000,000, more preferably in the range of 2,000 to 500,000. is there.

  As the polyimide, for example, a polyimide having high in-plane orientation and soluble in an organic solvent is preferable. Specifically, for example, it includes a condensation polymerization product of 9,9-bis (aminoaryl) fluorene and an aromatic tetracarboxylic dianhydride disclosed in JP 2000-511296 A, and has the following formula ( A polymer containing one or more repeating units shown in 1) can be used.

In the above formula (1), R ^{3 to} R ⁶ are each independently hydrogen, halogen, a phenyl group, a phenyl group substituted with ₁ to 4 halogen atoms or a C ₁ to ₁₀ alkyl group, and C _1. ~ At least one substituent selected from the group consisting of ₁₀ alkyl groups. ^Preferably, R 3 to R ⁶ are each independently, comprising halogen, phenyl group, from 1 to 4 halogen atoms or _C 1 _{~ 10} alkyl group-substituted phenyl group, and _C 1 _{~ 10} alkyl group At least one substituent selected from the group.

In the above formula (1), Z represents a tetravalent aromatic group C ₆ ~ _20, preferably a pyromellitic group, a polycyclic aromatic group, a derivative of a polycyclic aromatic group, or, It is group represented by following formula (2).

In the above formula (2), Z ′ is, for example, a covalent bond, C (R ⁷ ) ₂ group, CO group, O atom, S atom, SO ₂ group, Si (C ₂ H ₅ ) ₂ group, or NR ^Eight groups, and in the case of a plurality, they may be the same or different. W represents an integer from 1 to 10. Each R ⁷ is independently hydrogen or C (R ⁹ ) ₃ . R ⁸ is hydrogen, an alkyl group or a C ₆ ~ ₂₀ aryl group, the carbon atom number from 1 to about 20, for a plurality, may be different it may be respectively identical. Each R ⁹ is independently hydrogen, fluorine, or chlorine.

Examples of the polycyclic aromatic group include a tetravalent group derived from naphthalene, fluorene, benzofluorene or anthracene. Further, Examples of the substituted derivatives of the polycyclic aromatic group, for example, substituted with at least one alkyl group of C ₁ ~ _10, which is selected from the group consisting of fluorinated derivatives, and F or a halogen such as Cl And the above-mentioned polycyclic aromatic group.

  In addition, for example, a homopolymer described in JP-A-8-511812, wherein the repeating unit is represented by the following general formula (3) or (4), or the repeating unit is represented by the following general formula (5): The polyimide etc. which are shown are mentioned. In addition, the polyimide of following formula (5) is a preferable form of the homopolymer of following formula (3).

In the general formulas (3) to (5), G and G ′ are each independently, for example, a covalent bond, a CH ₂ group, a C (CH ₃ ) ₂ group, a C (CF ₃ ) ₂ group, a C ( CX ₃ ) ₂ groups (where X is a halogen), CO group, O atom, S atom, SO ₂ group, Si (CH ₂ CH ₃ ) ₂ group, and N (CH ₃ ) group Groups selected from the group consisting of, and may be the same or different.

In the above formulas (3) and (5), L is a substituent, and d and e represent the number of substitutions. L is, for example, a halogen, a C _1-3 alkyl group, a C _1-3 halogenated alkyl group, a phenyl group, or a substituted phenyl group, and in a plurality of cases, they may be the same or different. . As said substituted phenyl group, the substituted phenyl group which has at least 1 sort (s) of substituent selected from the group which consists of a halogen, a _C1-3 alkyl group, and a _C1-3 halogenated alkyl group, for example is mentioned. Examples of the halogen include fluorine, chlorine, bromine, and iodine. d is an integer from 0 to 2, and e is an integer from 0 to 3.

  In the above formulas (3) to (5), Q is a substituent, and f represents the number of substitutions. Q is, for example, selected from the group consisting of hydrogen, halogen, alkyl group, substituted alkyl group, nitro group, cyano group, thioalkyl group, alkoxy group, aryl group, substituted aryl group, alkyl ester group, and substituted alkyl ester group When Q is plural, they may be the same or different from each other. Examples of the halogen include fluorine, chlorine, bromine and iodine. As said substituted alkyl group, a halogenated alkyl group is mentioned, for example. Examples of the substituted aryl group include a halogenated aryl group. f is an integer from 0 to 4, g is an integer from 0 to 3, and h is an integer from 1 to 3. Further, g and h are preferably larger than 1.

In the above formula (4), R ¹⁰ and R ¹¹ are each independently a group selected from the group consisting of hydrogen, halogen, phenyl group, substituted phenyl group, alkyl group, and substituted alkyl group. Among these, R ¹⁰ and R ¹¹ are preferably each independently a halogenated alkyl group.

In the above formula (5), M ¹ and M ² are each independently, for example, a halogen, a C _1-3 alkyl group, a C _1-3 halogenated alkyl group, a phenyl group, or a substituted phenyl group. Examples of the halogen include fluorine, chlorine, bromine and iodine. Moreover, as said substituted phenyl group, the substituted phenyl group which has at least 1 sort (s) of substituent selected from the group which consists of a halogen, a _C1-3 alkyl group, and a _C1-3 halogenated alkyl group, for example is mentioned. .

  Specific examples of the polyimide represented by the above formula (3) include those represented by the following formula (6).

  Furthermore, examples of the polyimide include a copolymer obtained by appropriately copolymerizing an acid dianhydride other than the skeleton (repeating unit) as described above and a diamine.

  As said acid dianhydride, aromatic tetracarboxylic dianhydride is mentioned, for example. Examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride, benzophenone tetracarboxylic dianhydride, naphthalene tetracarboxylic dianhydride, heterocyclic aromatic tetracarboxylic dianhydride, 2 , 2′-substituted biphenyltetracarboxylic dianhydride and the like.

  Examples of the pyromellitic dianhydride include pyromellitic dianhydride, 3,6-diphenylpyromellitic dianhydride, 3,6-bis (trifluoromethyl) pyromellitic dianhydride, 3, Examples include 6-dibromopyromellitic dianhydride and 3,6-dichloropyromellitic dianhydride. Examples of the benzophenone tetracarboxylic dianhydride include 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 2,3,3 ′, 4′-benzophenone tetracarboxylic dianhydride, 2 , 2 ′, 3,3′-benzophenone tetracarboxylic dianhydride and the like. Examples of the naphthalenetetracarboxylic dianhydride include 2,3,6,7-naphthalene-tetracarboxylic dianhydride, 1,2,5,6-naphthalene-tetracarboxylic dianhydride, and 2,6. -Dichloro-naphthalene-1,4,5,8-tetracarboxylic dianhydride and the like. Examples of the heterocyclic aromatic tetracarboxylic dianhydride include, for example, thiophene-2,3,4,5-tetracarboxylic dianhydride, pyrazine-2,3,5,6-tetracarboxylic dianhydride. Pyridine-2,3,5,6-tetracarboxylic dianhydride and the like. Examples of the 2,2′-substituted biphenyltetracarboxylic dianhydride include 2,2′-dibromo-4,4 ′, 5,5′-biphenyltetracarboxylic dianhydride and 2,2′-dichloro. -4,4 ', 5,5'-biphenyltetracarboxylic dianhydride, 2,2'-bis (trifluoromethyl) -4,4', 5,5'-biphenyltetracarboxylic dianhydride, etc. Can be mentioned.

  Other examples of the aromatic tetracarboxylic dianhydride include 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and bis (2,3-dicarboxyphenyl) methane dianhydride. Bis (2,5,6-trifluoro-3,4-dicarboxyphenyl) methane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3 3-hexafluoropropane dianhydride, 4,4′-bis (3,4-dicarboxyphenyl) -2,2-diphenylpropane dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, 4,4′-oxydiphthalic dianhydride, bis (3,4-dicarboxyphenyl) sulfonic dianhydride, 3,3 ′, 4,4′-diphenylsulfone tetracarboxylic dianhydride, 4,4 ′ − [4,4′− Sopropylidene-di (p-phenyleneoxy)] bis (phthalic anhydride), N, N- (3,4-dicarboxyphenyl) -N-methylamine dianhydride, bis (3,4-dicarboxyphenyl) Examples include diethylsilane dianhydride.

  Among these, the aromatic tetracarboxylic dianhydride is preferably 2,2′-substituted biphenyltetracarboxylic dianhydride, more preferably 2,2′-bis (trihalomethyl) -4,4. ', 5,5'-biphenyltetracarboxylic dianhydride, more preferably 2,2'-bis (trifluoromethyl) -4,4', 5,5'-biphenyltetracarboxylic dianhydride It is.

  Examples of the diamine include aromatic diamines, and specific examples include benzene diamine, diaminobenzophenone, naphthalene diamine, heterocyclic aromatic diamine, and other aromatic diamines.

  Examples of the benzenediamine include o-, m- and p-phenylenediamine, 2,4-diaminotoluene, 1,4-diamino-2-methoxybenzene, 1,4-diamino-2-phenylbenzene and 1, Examples thereof include diamines selected from the group consisting of benzenediamines such as 3-diamino-4-chlorobenzene. Examples of the diaminobenzophenone include 2,2'-diaminobenzophenone and 3,3'-diaminobenzophenone. Examples of the naphthalenediamine include 1,8-diaminonaphthalene and 1,5-diaminonaphthalene. Examples of the heterocyclic aromatic diamine include 2,6-diaminopyridine, 2,4-diaminopyridine, and 2,4-diamino-S-triazine.

  In addition to the above, aromatic diamines include 4,4′-diaminobiphenyl, 4,4′-diaminodiphenylmethane, 4,4 ′-(9-fluorenylidene) -dianiline, 2,2′-bis (tri Fluoromethyl) -4,4′-diaminobiphenyl, 3,3′-dichloro-4,4′-diaminodiphenylmethane, 2,2′-dichloro-4,4′-diaminobiphenyl, 2,2 ′, 5,5 '-Tetrachlorobenzidine, 2,2-bis (4-aminophenoxyphenyl) propane, 2,2-bis (4-aminophenyl) propane, 2,2-bis (4-aminophenyl) -1,1,1 , 3,3,3-hexafluoropropane, 4,4′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 1,3-bis (3-aminophenoxy Benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, 4,4′-bis (3 -Aminophenoxy) biphenyl, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3 , 3-hexafluoropropane, 4,4′-diaminodiphenylthioether, 4,4′-diaminodiphenylsulfone, and the like.

  As said polyetherketone, the polyaryletherketone represented by following General formula (7) described in Unexamined-Japanese-Patent No. 2001-49110 is mentioned, for example.

  In the above formula (7), X represents a substituent, and q represents the number of substitutions. X is, for example, a halogen atom, a lower alkyl group, a halogenated alkyl group, a lower alkoxy group, or a halogenated alkoxy group, and when there are a plurality of X, they may be the same or different.

As said halogen atom, a fluorine atom, a bromine atom, a chlorine atom, and an iodine atom are mentioned, for example, Among these, a fluorine atom is preferable. Examples of the lower alkyl group, for example, preferably an alkyl group having a linear or branched C ₁ ~ _6, more preferably a straight-chain or branched alkyl group of C ₁ ~ _4. Specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group are preferable, and a methyl group and an ethyl group are particularly preferable. Examples of the halogenated alkyl group include halides of the lower alkyl group such as a trifluoromethyl group. Examples of the lower alkoxy group, for example, preferably a straight chain or branched chain alkoxy group of C ₁ ~ _6, more preferably a straight chain or branched chain alkoxy group of C ₁ ~ _4. Specifically, a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an isobutoxy group, a sec-butoxy group, and a tert-butoxy group are more preferable, and a methoxy group and an ethoxy group are particularly preferable. . Examples of the halogenated alkoxy group include halides of the lower alkoxy group such as a trifluoromethoxy group.

  In the above formula (7), q is an integer from 0 to 4. In the above formula (7), it is preferable that q = 0 and that the carbonyl group bonded to both ends of the benzene ring and the oxygen atom of the ether are present in the para position.

In the above formula (7), R ¹ is a group represented by the following formula (8), and m is an integer of 0 or 1.

  In the formula (8), X ′ represents a substituent, and is the same as X in the formula (7), for example. In the above formula (8), when there are a plurality of X ′, they may be the same or different. q ′ represents the number of substitutions of X ′, an integer from 0 to 4, and q ′ = 0 is preferable. P is an integer of 0 or 1.

In the above formula (8), ^{R 2} represents a divalent aromatic group. Examples of the divalent aromatic group include an o-, m- or p-phenylene group, or naphthalene, biphenyl, anthracene, o-, m- or p-terphenyl, phenanthrene, dibenzofuran, biphenyl ether, or And divalent groups derived from biphenylsulfone. In these divalent aromatic groups, hydrogen directly bonded to the aromatic group may be substituted with a halogen atom, a lower alkyl group or a lower alkoxy group. Among these, R ² is preferably an aromatic group selected from the group consisting of the following formulas (9) to (15).

In the above formula (7), R ¹ is preferably a group represented by the following formula (16). In the following formula (16), R ² and p are as defined in the above formula (8).

  Furthermore, in said formula (7), n represents a polymerization degree, for example, is the range of 2-5000, Preferably, it is the range of 5-500. Further, the polymerization may be composed of repeating units having the same structure, or may be composed of repeating units having different structures. In the latter case, the polymerization mode of the repeating unit may be block polymerization or random polymerization.

  Furthermore, it is preferable that the end of the polyaryl ether ketone represented by the above formula (7) is fluorine on the p-tetrafluorobenzoylene group side and a hydrogen atom on the oxyalkylene group side. For example, it can be represented by the following general formula (17). In the following formula, n represents the same degree of polymerization as in the above formula (7).

  Specific examples of the polyaryletherketone represented by the above formula (7) include those represented by the following formulas (18) to (21). In each of the following formulas, n represents the above formula (7). Represents the same degree of polymerization.

  In addition to these, examples of the polyamide or polyester include polyamides and polyesters described in JP-T-10-508048, and their repeating units are represented by the following general formula (22), for example. Can be represented.

In the above formula (22), Y is O or NH. E is, for example, a covalent bond, a C ₂ alkylene group, a halogenated C ₂ alkylene group, a CH ₂ group, a C (CX ₃ ) ₂ group (where X is a halogen or hydrogen), a CO group, It is at least one group selected from the group consisting of O atom, S atom, SO ₂ group, Si (R) ₂ group, and N (R) group, and may be the same or different. . In E, R is at least one of a C _1-3 alkyl group and a C _1-3 halogenated alkyl group, and is in a meta position or a para position with respect to a carbonyl functional group or a Y group.

  In the formula (22), A and A ′ are substituents, and t and z represent the number of substitutions. P is an integer from 0 to 3, q is an integer from 1 to 3, and r is an integer from 0 to 3.

A is, for example, an alkoxy group represented by hydrogen, halogen, a C _1-3 alkyl group, a C _1-3 halogenated alkyl group, OR (where R is as defined above), An aryl group, a substituted aryl group by halogenation, etc., a C _1-9 alkoxycarbonyl group, a C _1-9 alkylcarbonyloxy group, a C _1-12 aryloxycarbonyl group, a C _1-12 arylcarbonyloxy group and substituted derivatives thereof, C _1-12 arylcarbamoyl group, and is selected from the group consisting of C _1-12 arylcarbonylamino group and a substituted derivative thereof, in the case of a plurality, may be different may be respectively identical. The above A ′ is, for example, selected from the group consisting of halogen, C _1-3 alkyl group, C _1-3 halogenated alkyl group, phenyl group and substituted phenyl group. It may be. Examples of the substituent on the phenyl ring of the substituted phenyl group include a halogen, a C _1-3 alkyl group, a C _1-3 halogenated alkyl group, and a combination thereof. The t is an integer from 0 to 4, and the z is an integer from 0 to 3.

  Among the repeating units of polyamide or polyester represented by the above formula (22), those represented by the following general formula (23) are preferable.

  In the above formula (23), A, A ′ and Y are as defined in the above formula (22), and v is an integer of 0 to 3, preferably 0 to 2. x and y are each 0 or 1, but are not 0 at the same time.

  Next, a method for manufacturing the first optical compensation layer will be described. As a manufacturing method of the first optical compensation layer, any appropriate method can be adopted as long as the effects of the present invention can be obtained.

  The first optical compensation layer is preferably after a solution of at least one polymer selected from the group consisting of polyamide, polyimide, polyester, polyetherketone, polyamideimide, and polyesterimide is applied to the transparent polymer film It is formed by drying, forming the polymer layer on a transparent polymer film, and stretching or shrinking the transparent polymer film and the polymer layer together.

  The solvent of the coating solution (polymer solution to be applied to the transparent polymer film) is not particularly limited. For example, halogen such as chloroform, dichloromethane, carbon tetrachloride, dichloroethane, tetrachloroethane, trichloroethylene, tetrachloroethylene, chlorobenzene, orthodichlorobenzene, etc. Hydrocarbons; phenols such as phenol and parachlorophenol; aromatic hydrocarbons such as benzene, toluene, xylene, methoxybenzene, 1,2-dimethoxybenzene; acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, cyclopenta Ketone solvents such as non-, 2-pyrrolidone and N-methyl-2-pyrrolidone; ester solvents such as ethyl acetate and butyl acetate; t-butyl alcohol, glycerin, ethylene glycol, Alcohol solvents such as reethylene glycol, ethylene glycol monomethyl ether, diethylene glycol dimethyl ether, propylene glycol, dipropylene glycol and 2-methyl-2,4-pentanediol; amide solvents such as dimethylformamide and dimethylacetamide; acetonitrile and butyronitrile Nitrile solvents such as: ether solvents such as diethyl ether, dibutyl ether, and tetrahydrofuran; carbon disulfide, ethyl cellosolve, butyl cellosolve, and the like. Of these, methyl isobutyl ketone is preferred. This is because it exhibits high solubility in non-liquid crystal materials and does not erode the substrate. These solvents may be used alone or in combination of two or more.

  As the concentration of the non-liquid crystalline polymer in the coating solution, any appropriate concentration can be adopted as long as the above optical compensation layer is obtained and coating is possible. For example, the solution preferably contains 5 to 50 parts by weight, more preferably 10 to 40 parts by weight of the non-liquid crystalline polymer with respect to 100 parts by weight of the solvent. A solution having such a concentration range has a viscosity that is easy to apply.

  The coating solution may further contain various additives such as a stabilizer, a plasticizer, and metals as necessary.

  The coating solution may further contain other different resins as necessary. Examples of such other resins include various general-purpose resins, engineering plastics, thermoplastic resins, and thermosetting resins. By using such a resin in combination, it is possible to form an optical compensation layer having appropriate mechanical strength and durability depending on the purpose.

  Examples of the general-purpose resin include polyethylene (PE), polypropylene (PP), polystyrene (PS), polymethyl methacrylate (PMMA), ABS resin, and AS resin. Examples of the engineering plastic include polyacetate (POM), polycarbonate (PC), polyamide (PA: nylon), polyethylene terephthalate (PET), and polybutylene terephthalate (PBT). Examples of the thermoplastic resin include polyphenylene sulfide (PPS), polyethersulfone (PES), polyketone (PK), polyimide (PI), polycyclohexanedimethanol terephthalate (PCT), polyarylate (PAR), and liquid crystal polymer. (LCP) and the like. As said thermosetting resin, an epoxy resin, a phenol novolak resin, etc. are mentioned, for example.

  The kind and amount of the different resin added to the coating solution can be appropriately set according to the purpose. For example, such a resin can be added in a proportion of preferably 0 to 50% by mass, more preferably 0 to 30% by mass with respect to the non-liquid crystalline polymer.

  Examples of the coating method for the solution include spin coating, roll coating, flow coating, printing, dip coating, casting film formation, bar coating, and gravure printing. Further, in the application, a polymer layer superposition method may be employed as necessary.

  After coating, for example, the solvent in the solution is evaporated and removed by drying such as natural drying, air drying, and heat drying (for example, 60 to 250 ° C.) to form a film-like optical compensation layer.

  In order to provide a difference in refractive index (nx> ny) in the plane of the first optical compensation layer and to have optical biaxiality (nx> ny> nz), polyamide, polyimide, polyester, polyether A solution of at least one polymer selected from the group consisting of ketone, polyamideimide, and polyesterimide is applied to the transparent polymer film and then dried to form the polymer layer on the transparent polymer film, It is preferable to stretch or shrink the transparent polymer film and the polymer layer integrally. More specifically, as a method by contraction, the transparent polymer film and the polymer layer are integrally contracted by applying the above solution to a transparent polymer film that has been subjected to stretching treatment and drying, thereby optically refining. Axiality can be achieved. As a method by stretching, the above solution is applied to an unstretched transparent polymer film, dried and stretched while heating, so that the transparent polymer film and the polymer layer are stretched integrally, and optical biaxiality is achieved. Can be achieved. In this way, a laminate in which the first optical compensation layer is formed on the transparent polymer film (hereinafter sometimes referred to as “laminate A”) is obtained.

  As the transparent polymer film, a film similar to a protective film for a polarizer (described in the section B) can be used.

  The first optical compensation layer is used by peeling the first optical compensation layer from the laminate A obtained above (a laminate in which the first optical compensation layer is formed on the transparent polymer film). Alternatively, the laminate A may be used as it is. When the laminate A is used as it is and further laminated with a polarizer, the transparent polymer film in the laminate A may act as a protective film for the polarizer.

D. Second optical compensation layer The second optical compensation layer has a refractive index distribution represented by the formula (1):
nx>ny> nz (1).
Here, nx represents the refractive index in the slow axis direction, ny represents the refractive index in the fast axis direction, and nz represents the refractive index in the thickness direction. The slow axis refers to the direction in which the in-plane refractive index is maximized, and the fast axis refers to the direction perpendicular to the slow axis in the plane.

The second optical compensation layer satisfies equation (3):
0.97 <Δnd (x) / Δnd (590) <1.05 (3).
Here, Δnd (x) is an in-plane retardation value measured with light of wavelength x (450 nm ≦ x ≦ 700 nm), and Δnd (590) is an in-plane retardation value measured with light of wavelength 590 nm. Show.

  Δnd (x) and Δnd (590) of the second optical compensation layer are preferably 20 to 200 nm, more preferably 40 to 180 nm, and still more preferably 60 to 160 nm. In the present invention, Δnd (590) of the second optical compensation layer is preferably larger than Δnd (590) of the first optical compensation layer.

  The thickness of the second optical compensation layer may be set so as to obtain a desired in-plane retardation. Specifically, when obtained by coating, the thickness is preferably 1 to 15 μm, more preferably 1.5 to 10 μm, and most preferably 2 to 8 μm. When obtained as a film, it is preferably 30 to 120 μm, more preferably 40 to 100 μm, and most preferably 50 to 90 μm.

  The second optical compensation layer can be typically formed by stretching a polymer film. For example, the second optical material having desired optical characteristics (for example, refractive index distribution, in-plane retardation, thickness direction retardation, Nz coefficient) by appropriately selecting the type of polymer, stretching conditions, stretching method, and the like. A compensation layer can be obtained.

  Any appropriate polymer can be adopted as the polymer constituting the polymer film. Specific examples include polycarbonate polymers, norbornene polymers, cellulose polymers, polyvinyl alcohol polymers, polysulfone polymers, and the like.

  Examples of norbornene resins include ring-opening (co) polymers of norbornene monomers, addition polymers of norbornene monomers, and copolymers of norbornene monomers and α-olefins such as ethylene and propylene (typically , Random copolymers), graft modified products obtained by modifying these with an unsaturated carboxylic acid or a derivative thereof, and hydrides thereof.

  Examples of the norbornene-based monomer used to obtain the norbornene-based resin include norbornene and alkyl and / or alkylidene substituted products thereof such as 5-methyl-2-norbornene, 5-dimethyl-2-norbornene, and 5-ethyl. 2-norbornene, 5-butyl-2-norbornene, 5-ethylidene-2-norbornene, etc., polar group substitution products such as halogens; dicyclopentadiene, 2,3-dihydrodicyclopentadiene, etc .; dimethanooctahydro Naphthalene, its alkyl and / or alkylidene substituents, and polar group substituents such as halogen such as 6-methyl-1,4: 5,8-dimethano-1,4,4a, 5,6,7,8, 8a-octahydronaphthalene, 6-ethyl-1,4: 5,8-dimethano-1, , 4a, 5,6,7,8,8a-octahydronaphthalene, 6-ethylidene-1,4: 5,8-dimethano-1,4,4a, 5,6,7,8,8a-octahydronaphthalene 6-chloro-1,4: 5,8-dimethano-1,4,4a, 5,6,7,8,8a-octahydronaphthalene, 6-cyano-1,4: 5,8-dimethano-1 , 4,4a, 5,6,7,8,8a-octahydronaphthalene, 6-pyridyl-1,4: 5,8-dimethano-1,4,4a, 5,6,7,8,8a-octa Hydronaphthalene, 6-methoxycarbonyl-1,4: 5,8-dimethano-1,4,4a, 5,6,7,8,8a-octahydronaphthalene and the like; 3-pentamer of cyclopentadiene, for example, 4,9: 5,8-dimethano-3a, 4,4a, 5,8,8a, 9, a-Octahydro-1H-benzoindene, 4,11: 5, 10: 6,9-trimethano-3a, 4,4a, 5,5a, 6,9,9a, 10,10a, 11,11a-dodecahydro-1H -Cyclopentaanthracene etc. are mentioned. These may be used alone or in combination of two or more.

  In order to obtain a norbornene-based resin, in addition to the norbornene-based monomer, other cycloolefins that can be ring-opening polymerized as cyclic olefins can be used in combination as long as the object of the present invention is not impaired. Specific examples of such cycloolefins include compounds having one reactive double bond such as cyclopentene, cyclooctene, and 5,6-dihydrodicyclopentadiene.

  The norbornene-based resin preferably has a number average molecular weight (Mn) measured by a gel permeation chromatography (GPC) method using a toluene solvent, preferably 25,000 to 200,000, more preferably 30,000 to 100,000. Most preferably, it is 40,000-80,000. When the number average molecular weight is in the above range, a material having excellent mechanical strength and good solubility, moldability, and operability can be obtained.

  When the norbornene-based resin is obtained by hydrogenating a ring-opening polymer of a norbornene-based monomer, the hydrogenation rate is preferably 90% or more, more preferably 95% or more, and most preferably Is 99% or more. Within such a range, the heat deterioration resistance and light deterioration resistance are excellent.

  As the norbornene resin, various products are commercially available. Specific examples include trade names such as ZEONEX and ZEONOR manufactured by ZEON Corporation, ARTON manufactured by JSR Corporation, and TOPAS manufactured by TICONA Corporation.

E. Transparent Protective Layer The liquid crystal panel 100 of the present invention is provided with a transparent protective layer on the outside of the polarizer (the first polarizer 30 and / or the second polarizer 50) (ie, as the outermost layer) as necessary. You may have. By providing the transparent protective layer, deterioration of the polarizer can be prevented.

  Any appropriate protective layer may be employed as the transparent protective layer depending on the purpose. The transparent protective layer is made of, for example, a plastic film that is excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy, and the like. Specific examples of the resin constituting the plastic film include cellulose resin such as triacetyl cellulose (TAC), acetate resin, polyester resin, polyethersulfone resin, polysulfone resin, polycarbonate resin, polyamide resin, polyimide resin, polyolefin resin, acrylic resin. Resins, polynorbornene resins, polyarylate resins, polystyrene resins, polyvinyl alcohol resins, polyacrylic resins, and mixtures thereof. Also, thermosetting resins such as acrylic, urethane, acrylic urethane, epoxy, and silicone, or ultraviolet curable resins may be used. From the viewpoint of polarization characteristics and durability, a TAC film whose surface is saponified with alkali or the like is preferable.

  Furthermore, for example, a polymer film formed from a resin composition as described in JP-A-2001-343529 (WO 01/37007) can also be used for the transparent protective layer. More specifically, it is a mixture of a thermoplastic resin having a substituted imide group or an unsubstituted imide group in the side chain and a thermoplastic resin having a substituted phenyl group or an unsubstituted phenyl group and a cyano group in the side chain. Specific examples include a resin composition having an alternating copolymer composed of isobutene and N-methylenemaleimide and an acrylonitrile / styrene copolymer. For example, an extruded product of such a resin composition can be used.

  The transparent protective layer is transparent as the name suggests, and preferably has no color. Specifically, the thickness direction retardation Rth of the transparent protective layer is preferably −90 nm to +75 nm, more preferably −80 nm to +60 nm, and most preferably −70 nm to +45 nm. If the retardation Rth in the thickness direction of the transparent protective layer is in such a range, the optical coloring of the polarizer caused by the protective layer can be eliminated.

  The thickness of the transparent protective layer can be appropriately set according to the purpose. The thickness of the transparent protective layer is typically 500 μm or less, preferably 5 to 300 μm, and more preferably 5 to 150 μm.

F. Lamination of first polarizer and first optical compensation layer In the liquid crystal panel of the present invention, the first polarizer 30 and the first optical compensation layer 60 are laminated. One of the preferred embodiments is that the laminate A (a laminate in which the first optical compensation layer 60 is formed on the transparent protective film) is bonded to the first polarizer 30 via an adhesive layer. Become. As for the adhesion between the laminate A and the first polarizer 30, it is preferable to adhere the transparent protective film side of the laminate A to the first polarizer 30. In another preferred embodiment, the first polarizer 30 in which a polarizer protective film is laminated on at least one surface is bonded to the first optical compensation layer 60 through an adhesive layer. The first polarizer 30 having a polarizer protective film laminated on at least one side and the first optical compensation layer 60 are bonded to each other by the polarizer of the first polarizer 30 having a polarizer protective film laminated on at least one side. It is preferable to adhere the protective film side to the first optical compensation layer 60.

  A transparent protective layer may be bonded to the other side of the first polarizer 30.

  The adhesive layer is preferably a layer formed from a polyvinyl alcohol-based adhesive. The polyvinyl alcohol-based adhesive contains a polyvinyl alcohol-based resin and a crosslinking agent.

  The polyvinyl alcohol-based resin is not particularly limited. For example, polyvinyl alcohol obtained by saponifying polyvinyl acetate; a derivative thereof; and a saponified product of a copolymer with a monomer having copolymerizability with vinyl acetate. Modified polyvinyl alcohol obtained by acetalization, urethanization, etherification, grafting, phosphoric esterification, etc. of polyvinyl alcohol. Examples of the monomer include unsaturated carboxylic acids such as (anhydrous) maleic acid, fumaric acid, crotonic acid, itaconic acid, (meth) acrylic acid, and esters thereof; α-olefins such as ethylene and propylene, (meth) Examples include allyl sulfonic acid (soda), sulfonic acid soda (monoalkyl malate), disulfonic acid soda alkyl maleate, N-methylol acrylamide, acrylamide alkyl sulfonic acid alkali salt, N-vinyl pyrrolidone, N-vinyl pyrrolidone derivatives, and the like. . These polyvinyl alcohol resins may be used alone or in combination of two or more.

  From the viewpoint of adhesiveness, the polyvinyl alcohol-based resin preferably has an average degree of polymerization of 100 to 3000, more preferably 500 to 3000, and an average degree of saponification of preferably 85 to 100 mol%, more preferably 90. ˜100 mol%.

  As the polyvinyl alcohol resin, a polyvinyl alcohol resin having an acetoacetyl group can be used. A polyvinyl alcohol-based resin having an acetoacetyl group is a polyvinyl alcohol-based adhesive having a highly reactive functional group, and is preferable in terms of improving the durability of the obtained optical film.

  A polyvinyl alcohol-based resin containing an acetoacetyl group is obtained by reacting a polyvinyl alcohol-based resin with diketene by a known method. For example, a method in which a polyvinyl alcohol resin is dispersed in a solvent such as acetic acid and diketene is added thereto, and a polyvinyl alcohol resin is previously dissolved in a solvent such as dimethylformamide or dioxane, and diketene is added thereto. And the like. Moreover, the method of making diketene gas or liquid diketene contact directly to polyvinyl alcohol is mentioned.

  The degree of acetoacetyl group modification of the polyvinyl alcohol resin having an acetoacetyl group is not particularly limited as long as it is 0.1 mol% or more. If it is less than 0.1 mol%, the water resistance of the adhesive layer is insufficient, which is inappropriate. The degree of acetoacetyl modification is preferably 0.1 to 40 mol%, more preferably 1 to 20 mol%. When the degree of acetoacetyl modification exceeds 40 mol%, the number of reaction points with the cross-linking agent decreases, and the effect of improving water resistance is small. The degree of acetoacetyl modification is a value measured by NMR.

As said crosslinking agent, what is used for the polyvinyl alcohol-type adhesive agent can be especially used without a restriction | limiting.
As the crosslinking agent, a compound having at least two functional groups having reactivity with the polyvinyl alcohol resin can be used. For example, alkylene diamines having two alkylene groups and two amino groups such as ethylene diamine, triethylene amine, hexamethylene diamine (hexamethylene diamine is preferred); tolylene diisocyanate, hydrogenated tolylene diisocyanate, trimethylene propane tolylene Isocyanate adduct, triphenylmethane triisocyanate, methylene bis (4-phenylmethane triisocyanate, isophorone diisocyanate and isocyanates such as ketoxime block or phenol block; ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin di Or triglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylo Epoxys such as rupropane triglycidyl ether, diglycidyl aniline, diglycidyl amine; monoaldehydes such as formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde; glyoxal, malondialdehyde, succindialdehyde, glutardialdehyde, maleidialdehyde , Dialdehydes such as phthaldialdehyde; amino-formaldehyde resins such as methylol urea, methylol melamine, alkylated methylol urea, alkylated methylolated melamine, acetoguanamine, condensates of benzoguanamine and formaldehyde; sodium, potassium, magnesium Divalent metals such as calcium, aluminum, iron and nickel, or salts of trivalent metals and oxides thereof. Is to, melamine-based crosslinking agent is preferably, suitable in particular melamine.

  The amount of the crosslinking agent is preferably 0.1 to 35 parts by weight, more preferably 10 to 25 parts by weight with respect to 100 parts by weight of the polyvinyl alcohol resin. On the other hand, in order to further improve the durability, the crosslinking agent can be blended in an amount exceeding 30 parts by weight and not more than 46 parts by weight with respect to 100 parts by weight of the polyvinyl alcohol resin. In particular, when a polyvinyl alcohol-based resin containing an acetoacetyl group is used, it is preferable to use the crosslinking agent in an amount exceeding 30 parts by weight. Water resistance improves by mix | blending a crosslinking agent in the range of more than 30 weight part and 46 weight part or less.

  The polyvinyl alcohol-based adhesive further includes coupling agents such as silane coupling agents and titanium coupling agents, various tackifiers, ultraviolet absorbers, antioxidants, heat stabilizers, hydrolysis stabilizers, and the like. A stabilizer or the like can also be blended.

  The surface that is in contact with the first polarizer 30 (preferably, the transparent protective film surface of the laminate A or the polarizer protective film surface) can be subjected to an easy adhesion treatment in order to improve adhesion. Examples of the easy adhesion treatment include surface treatment such as corona treatment, plasma treatment, low-pressure UV treatment, and saponification treatment, and a method of forming an anchor layer, and these can be used in combination. Among these, a corona treatment, a method of forming an anchor layer, and a method of using these in combination are preferable.

  Examples of the anchor layer include a silicone layer having a reactive functional group. The material of the silicone layer having a reactive functional group is not particularly limited. For example, an isocyanate group-containing alkoxysilanol, an amino group-containing alkoxysilanol, a mercapto group-containing alkoxysilanol, a carboxy-containing alkoxysilanol, an epoxy group-containing Examples thereof include alkoxysilanols, vinyl-type unsaturated group-containing alkoxysilanols, halogen group-containing alkoxylanols, and isocyanate group-containing alkoxysilanols, and amino silanols are preferred. Furthermore, the adhesive force can be strengthened by adding a titanium-based catalyst or a tin-based catalyst for efficiently reacting the silanol. Moreover, you may add another additive to the silicone which has the said reactive functional group. Specifically, terpene resins, phenol resins, terpene-phenol resins, rosin resins, xylene resins and other tackifiers, UV absorbers, antioxidants, heat stabilizers and other stabilizers may be used.

  The silicone layer having the reactive functional group is formed by coating and drying by a known technique. The thickness of the silicone layer is preferably 1 to 100 nm, more preferably 10 to 50 nm after drying. During coating, silicone having a reactive functional group may be diluted with a solvent. The dilution solvent is not particularly limited, and examples thereof include alcohols. The dilution concentration is not particularly limited, but is preferably 1 to 5% by weight, more preferably 1 to 3% by weight.

  In the formation of the adhesive layer, the adhesive is applied to either the transparent protective film side of the laminate A or the adhesive surface side of the polarizer protective film to the first polarizer 30, either of the first polarizer 30. It is preferable to carry out by applying to the side or both sides. After laminating the transparent protective film surface of the laminate A or the adhesive surface of the polarizer protective film to the first polarizer 30 and the first polarizer 30, a drying step is performed to form a coating dry layer. It is preferable to form an adhesive layer. This can also be bonded after forming the adhesive layer. The bonding can be performed with a roll laminator or the like. The heating and drying temperature and drying time are appropriately determined according to the type of adhesive.

  The thickness of the adhesive layer is preferably 0.01 to 10 μm, more preferably 0.03 to 5 μm, since it is not preferable in terms of adhesiveness when the thickness after drying becomes too thick.

  The laminate of the first polarizer and the first optical compensation layer may further include an adhesive layer as at least one of the outermost layers (preferably, the first optical compensation layer side). The purpose of providing the pressure-sensitive adhesive layer is, for example, to adhere to another member such as another optical film or a liquid crystal cell.

  The pressure-sensitive adhesive forming the pressure-sensitive adhesive layer is not particularly limited. For example, an acrylic polymer, silicone polymer, polyester, polyurethane, polyamide, polyether, fluorine-based or rubber-based polymer is used as a base polymer. It can select suitably and can be used. In particular, those having excellent optical transparency such as an acrylic pressure-sensitive adhesive, exhibiting appropriate wettability, cohesiveness, and adhesive pressure-sensitive adhesive properties, and being excellent in weather resistance and heat resistance can be preferably used. In particular, an acrylic pressure-sensitive adhesive made of an acrylic polymer having 4 to 12 carbon atoms is preferable.

  In addition to the above, from the viewpoints of prevention of foaming phenomenon and peeling phenomenon due to moisture absorption, deterioration of optical characteristics due to thermal expansion difference and the like, prevention of warpage of liquid crystal cell, and high-quality and durable liquid crystal display device. A pressure-sensitive adhesive layer having a low moisture absorption rate and excellent heat resistance is preferred.

  The pressure-sensitive adhesive layer is, for example, a natural or synthetic resin, in particular, a tackifier resin, a filler or pigment made of glass fiber, glass beads, metal powder, other inorganic powders, a colorant, an antioxidant. An additive to be added to the pressure-sensitive adhesive layer such as an agent may be contained.

  The pressure-sensitive adhesive layer may be a pressure-sensitive adhesive layer containing fine particles and exhibiting light diffusibility.

  The attachment of the pressure-sensitive adhesive layer can be performed by an appropriate method. For example, a pressure sensitive adhesive solution of about 10 to 40% by weight in which a base polymer or a composition thereof is dissolved or dispersed in a solvent composed of a suitable solvent alone or a mixture such as toluene and ethyl acetate is prepared. A method of directly attaching it on an optical film (for example, the first optical compensation layer) by an appropriate development method such as a casting method or a coating method, or forming an adhesive layer on a separator according to the above, Is transferred to the surface of the optical film (for example, the first optical compensation layer).

  The pressure-sensitive adhesive layer can be provided on one side or both sides of an optical film (for example, the first optical compensation layer) as an overlapping layer of different compositions or types. Moreover, when providing in both surfaces, it can also be set as adhesive layers, such as a different composition, a kind, and thickness, in the front and back of an optical film.

  The thickness of the pressure-sensitive adhesive layer can be appropriately determined according to the purpose of use and adhesive force, and is preferably 1 to 40 μm, more preferably 5 to 30 μm, and particularly preferably 10 to 25 μm. When the thickness is less than 1 μm, the durability is deteriorated. When the thickness is more than 40 μm, floating or peeling due to foaming or the like is liable to occur, resulting in poor appearance.

  In order to improve the adhesion between the optical film (for example, the first optical compensation layer) and the pressure-sensitive adhesive layer, an anchor layer may be provided between the layers.

  As the anchor layer, an anchor layer selected from polyurethane, polyester and polymers containing an amino group in the molecule is preferably used, and polymers containing an amino group in the molecule are particularly preferably used. Polymers containing amino groups in the molecule are good because the amino groups in the molecule exhibit interactions such as reaction or ionic interaction with carboxyl groups in the adhesive and polar groups in the conductive polymer. Adhesion is ensured.

  Examples of the polymer containing an amino group in the molecule include, for example, polyethyleneimine, polyallylamine, polyvinylamine, polyvinylpyridine, polyvinylpyrrolidine, and amino-containing groups such as dimethylaminoethyl acrylate shown as a copolymerization monomer of the above-mentioned acrylic adhesive. Examples thereof include polymers of contained monomers.

  In order to impart antistatic properties to the anchor layer, an antistatic agent may be added. Antistatic agents for imparting antistatic properties include ionic surfactant systems, conductive polymer systems such as polyaniline, polythiophene, polypyrrole, and polyquinoxaline, and metal oxide systems such as tin oxide, antimony oxide, and indium oxide. In particular, a conductive polymer system is preferably used from the viewpoint of optical characteristics, appearance, antistatic effect, and stability of the antistatic effect when heated and humidified. Among these, water-soluble conductive polymers such as polyaniline and polythiophene or water-dispersible conductive polymers are particularly preferably used. This is because, when a water-soluble conductive polymer or a water-dispersible conductive polymer is used as a material for forming the antistatic layer, it is possible to suppress deterioration of the optical film substrate due to an organic solvent during the coating process.

  In the present invention, each layer such as the first polarizer 30, the first optical compensation layer 60, the adhesive layer, and the pressure-sensitive adhesive layer includes, for example, a salicylic acid ester compound, a benzophenol compound, a benzotriazole compound, Those having an ultraviolet absorbing ability by a method such as a method of treating with an ultraviolet absorber such as a cyanoacrylate compound or a nickel complex salt compound may be used.

G. Lamination of Second Polarizer and Second Optical Compensation Layer In the liquid crystal panel of the present invention, the second polarizer 50 and the second optical compensation layer 70 are laminated. One of the preferred embodiments is that a second polarizer 50 having a polarizer protective film laminated on at least one surface is bonded to the second optical compensation layer 70 via an adhesive layer. The adhesion between the second polarizer 50 having the polarizer protective film laminated on at least one side and the second optical compensation layer 70 is the polarizer of the second polarizer 50 having the polarizer protective film laminated on at least one side. It is preferable to adhere the protective film side to the second optical compensation layer 70.

  A transparent protective layer may be bonded to the other surface of the second polarizer 50.

  The adhesive layer is preferably a layer formed from a polyvinyl alcohol-based adhesive. The polyvinyl alcohol-based adhesive contains a polyvinyl alcohol-based resin and a crosslinking agent.

  As the polyvinyl alcohol-based resin and the cross-linking agent, the same polyvinyl alcohol-based resin and cross-linking agent as described in the section F can be used.

  The surface that is in contact with the second polarizer 50 (preferably the surface of the polarizer protective film) can be subjected to easy adhesion treatment in order to improve adhesion. Examples of the easy-adhesion treatment include the same methods as those described in the above section F, such as corona treatment, plasma treatment, low-pressure UV treatment, saponification treatment, and the like, and a method of forming an anchor layer. You can also. Among these, a corona treatment, a method of forming an anchor layer, and a method of using these in combination are preferable.

  The formation of the adhesive layer is performed by applying the adhesive on the adhesive surface side of the polarizer protective film to the second polarizer 50, on either side or both sides of the second polarizer 50. Is preferred. After adhering the adhesive surface of the polarizer protective film to the second polarizer 50 and the second polarizer 50, it is preferable to perform a drying step to form an adhesive layer composed of a coating dry layer. . This can also be bonded after forming the adhesive layer. The bonding can be performed with a roll laminator or the like. The heating and drying temperature and drying time are appropriately determined according to the type of adhesive.

  The thickness of the adhesive layer is preferably 0.01 to 10 μm, more preferably 0.03 to 5 μm, since it is not preferable in terms of adhesiveness when the thickness after drying becomes too thick.

  The laminate of the second polarizer 50 and the second optical compensation layer may further include an adhesive layer as at least one of the outermost layers (preferably, the second optical compensation layer side). The purpose of providing the pressure-sensitive adhesive layer is, for example, to adhere to another member such as another optical film or a liquid crystal cell.

  As the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer and the method of attaching the pressure-sensitive adhesive layer, the same pressure-sensitive adhesive as described in the above section F can be used.

  In order to improve the adhesion between the optical film (for example, the second optical compensation layer) and the pressure-sensitive adhesive layer, an anchor layer may be provided between the layers.

  As the anchor layer, an anchor layer similar to that described in the section F can be employed.

  In the present invention, each layer such as the second polarizer 50, the second optical compensation layer 70, the adhesive layer, and the pressure-sensitive adhesive layer includes, for example, a salicylic acid ester compound, a benzophenol compound, a benzotriazole compound, Those having an ultraviolet absorbing ability by a method such as a method of treating with an ultraviolet absorber such as a cyanoacrylate compound or a nickel complex salt compound may be used.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited by these Examples. The measuring method of each characteristic in an Example is as follows.

<Measurement of phase difference>
Refractive indexes nx, ny and nz of the sample film are measured by an automatic birefringence measuring apparatus (manufactured by Oji Scientific Instruments, automatic birefringence meter KOBRA21-ADH), and in-plane retardation Δnd and thickness direction retardation Rth are calculated. did. The measurement temperature was 23 ° C. and the measurement wavelength was 590 nm.

<Measurement of color shift>
Using ELDIM trade name “EZ Contrast 160D”, the azimuth angle was changed to 45 ° and the polar angle was changed to 0 to 80 °, and the color tone of the liquid crystal display device was measured and plotted on the XY chromaticity diagram. The azimuth angle and polar angle are as shown in FIG.

[Reference Example 1]: Preparation of Polarizer After a polyvinyl alcohol film is dyed in an aqueous solution containing iodine, the polarizer is uniaxially stretched 6 times between rolls having different speed ratios in an aqueous solution containing boric acid. Produced.

  [Reference Example 2]: Preparation of polyvinyl alcohol-based adhesive)

  A polyvinyl alcohol adhesive aqueous solution prepared by adjusting an aqueous solution containing 20 parts by weight of methylolmelamine to 100 parts by weight of an acetoacetyl-modified polyvinyl alcohol resin (degree of acetylation 13%) to a concentration of 0.5% by weight Prepared.

シクロペンタノンを、ポリエチレンテレフタレート上に塗布した後、これを厚み４０μｍのトリアセチルセルロースフィルム（富士写真フィルム（株）製、商品名「ＵＺ−ＴＡＣ」、Ｒｅ（５９０）＝３ｎｍ、Ｒｔｈ（５９０）＝４０ｎｍ）に貼り合わせた。これを１００℃で５分間乾燥した。乾燥後にポリエチレンテレフタレートフィルムを剥離した。得られたセルロース系フィルム（以下、０ＴＡＣと称することがある）は、Ｒｅ（５９０）＝０．２ｎｍ、Ｒｔｈ（５９０）＝５．４ｎｍであった。
ＴＡＣ（厚み４０μｍ）と偏光子と０ＴＡＣとを、ポリビニルアルコール系接着剤（０．５μｍ）で貼り合わせ、ＴＡＣ−偏光子−０ＴＡＣからなる偏光板（Ｂ１）を得た。
次に、第２の光学補償フィルムを、偏光板（Ｂ１）の偏光子の吸収軸と第２の光学補償フィルムの遅相軸（延伸軸）が直交するように、アクリル系粘着剤（厚み２０μｍ）を介して偏光板（Ｂ１）の０ＴＡＣ側に貼り合わせた。
上記で得られた２つの偏光板一体フィルムをそれぞれ偏光板の延伸軸が直交するように、液晶セルの上下（上側：偏光板（Ｂ１）一体フィルムの第２の光学補償フィルム側を貼り合わせ、下側：偏光板（Ａ１）一体フィルムのポリイミド層側を貼り合わせ）にアクリル系粘着剤（厚み２０μｍ）で貼り合せた。液晶セルは、市販の液晶ＴＶ（ＳＨＡＲＰ製の商品名「ＡＱＵＯＳ２６インチ」）から取り外して使用した。このＴＶの視野角特性（カラーシフト）をＥＬＤＩＭ製のＥＺＣｏｎｔｒａｓｔで測定した結果を図５に示す。図５では、偏光板の延伸軸と４５°の方位に視角を正面から８０°まで倒していった場合のカラーシフトを色度図上で示した。 ([TAC-polarizer-TAC]-(parallel) -polyimide layer-liquid crystal cell-zeonore- (orthogonal)-[0TAC-polarizer-TAC])
2,2'-bis (3,4-dicarboxyphenyl) hexafluoropropane) and 2,2'-bis (trifluoromethyl) -4, using cyclohexanone as a solvent on a triacetyl cellulose (TAC) substrate A solution prepared by preparing 15% by weight of a polyimide synthesized from 4′-diaminobiphenyl was applied to a thickness of 20 μm. Then, a thin film having a thickness of about 2.5 μm was obtained by drying at 100 ° C. for 10 minutes. The obtained film was stretched 1.05 times at 150 ° C. to prepare a first optical compensation film.
When the phase difference including the base material of the obtained first optical compensation film was measured using KOBRA 21-ADH manufactured by Oji Scientific, the relationship of nx>ny> nz was satisfied, and the in-plane retardation Δnd was 18 nm, The thickness direction retardation Rth was 137 nm, and the Nz coefficient (Nz = (nx−nz) / (nx−ny)) was 7.6.
The triacetylcellulose substrate of the first optical compensation film and the polarizer, and polyvinyl alcohol so that the absorption axis of the polarizer and the slow axis (stretching axis) of the first optical compensation film are coaxial (parallel). Bonding was performed using a system adhesive (0.5 μm). Furthermore, the side opposite to the first optical compensation film of the polarizer was bonded with a triacetyl cellulose base material (thickness 40 μm) and a polyvinyl alcohol-based adhesive (0.5 μm).
Thus, a polarizing plate (A1) composed of polyimide layer-TAC-polarizer-TAC was obtained.
Next, the product name “ZEONOR” (100 μm before stretching) made by Nippon Zeon, a norbornene-based film, is 1.25 times in the X-axis direction and 135 times 1.03 times in the Y-axis direction at 135 ° C. The film was axially stretched to produce a second optical compensation film (thickness after stretching was 90 μm).
When the retardation of the obtained second optical compensation film was measured using KOBRA 21-ADH manufactured by Oji Scientific Co., Ltd., the in-plane retardation Δnd was 78 nm, the thickness direction retardation Rth was 170 nm, and the Nz coefficient (Nz = (Nz = ( nx-nz) / (nx-ny)) was 2.2. Δnd (x) / Δnd (590) of the second optical compensation film measured with light having a wavelength x (450 nm ≦ x ≦ 700 nm) was as shown in Table 1.

After cyclopentanone was coated on polyethylene terephthalate, this was coated with a 40 μm thick triacetyl cellulose film (Fuji Photo Film Co., Ltd., trade name “UZ-TAC”, Re (590) = 3 nm, Rth (590) = 40 nm). This was dried at 100 ° C. for 5 minutes. After drying, the polyethylene terephthalate film was peeled off. The obtained cellulose-based film (hereinafter sometimes referred to as 0TAC) had Re (590) = 0.2 nm and Rth (590) = 5.4 nm.
TAC (thickness 40 μm), polarizer and 0TAC were bonded together with a polyvinyl alcohol adhesive (0.5 μm) to obtain a polarizing plate (B1) composed of TAC-polarizer-0TAC.
Next, an acrylic pressure-sensitive adhesive (thickness 20 μm) is used so that the absorption axis of the polarizer of the polarizing plate (B1) and the slow axis (stretching axis) of the second optical compensation film are orthogonal to each other. ) To the 0TAC side of the polarizing plate (B1).
The two polarizing plate integrated films obtained above are bonded to the upper and lower sides of the liquid crystal cell (upper side: polarizing plate (B1), the second optical compensation film side of the polarizing plate (B1) integrated film, so that the stretching axes of the polarizing plates are orthogonal to each other, Lower side: Affixed to the polarizing plate (A1) integrated film on the polyimide layer side) with an acrylic adhesive (thickness 20 μm). The liquid crystal cell was used after being removed from a commercially available liquid crystal TV (trade name “AQUAS26 inch” manufactured by SHARP). FIG. 5 shows the results of measuring the viewing angle characteristics (color shift) of this TV with EZContrast manufactured by ELDIM. FIG. 5 shows a color shift on the chromaticity diagram when the viewing angle is tilted from the front to 80 ° in the direction of 45 ° with respect to the stretching axis of the polarizing plate.

([TAC-polarizer-TAC]-(parallel) -polyimide layer-liquid crystal cell-zeonore- (orthogonal)-[0TAC-polarizer-TAC])
2,2'-bis (3,4-dicarboxyphenyl) hexafluoropropane) and 2,2'-bis (trifluoromethyl) -4, using cyclohexanone as a solvent on a triacetyl cellulose (TAC) substrate A solution prepared by preparing 15% by weight of a polyimide synthesized from 4′-diaminobiphenyl was applied to a thickness of 20 μm. Then, a thin film having a thickness of about 2.5 μm was obtained by drying at 100 ° C. for 10 minutes. The obtained film was longitudinally stretched 1.05 times at 150 ° C. to prepare a first optical compensation film.
When the phase difference of the obtained first optical compensation film including the base material was measured using KOBRA 21-ADH manufactured by Oji Scientific, the relationship of nx>ny> nz was satisfied, and the in-plane retardation Δnd was 25 nm, The thickness direction retardation Rth was 150 nm, and the Nz coefficient (Nz = (nx−nz) / (nx−ny)) was 6.0.
The triacetylcellulose substrate of the first optical compensation film and the polarizer, and polyvinyl alcohol so that the absorption axis of the polarizer and the slow axis (stretching axis) of the first optical compensation film are coaxial (parallel). Bonding was performed using a system adhesive (0.5 μm). Furthermore, the side opposite to the first optical compensation film of the polarizer was bonded with a triacetyl cellulose base material (thickness 40 μm) and a polyvinyl alcohol-based adhesive (0.5 μm).
Thus, a polarizing plate (A2) composed of polyimide layer-TAC-polarizer-TAC was obtained.
Next, the product name “ZEONOR” (100 μm before stretching) made by Nippon Zeon, which is a norbornene-based film, is stretched at a fixed end of 1.5 times in the X-axis direction at 145 ° C. to obtain the second optical compensation. A film (thickness after stretching was 85 μm) was prepared.
When the retardation of the obtained second optical compensation film was measured using KOBRA 21-ADH manufactured by Oji Scientific Co., Ltd., the in-plane retardation Δnd was 100 nm, the thickness direction retardation Rth was 180 nm, and the Nz coefficient (Nz = (Nz = ( nx-nz) / (nx-ny)) was 1.8. Δnd (x) / Δnd (590) of the second optical compensation film measured with light having a wavelength x (450 nm ≦ x ≦ 700 nm) was the same as that shown in Table 1 above.
TAC (thickness 40 μm), polarizer and 0TAC were bonded together with a polyvinyl alcohol adhesive (0.5 μm) to obtain a polarizing plate (B2) composed of TAC-polarizer-0TAC.
Next, an acrylic pressure-sensitive adhesive (thickness 20 μm) is used so that the absorption axis of the polarizer of the polarizing plate (B2) and the slow axis (stretching axis) of the second optical compensation film are orthogonal to each other. ) To the 0TAC side of the polarizing plate (B2).
The two polarizing plate integrated films obtained above are bonded to the upper and lower sides of the liquid crystal cell (upper side: polarizing plate (B2), the second optical compensation film side of the polarizing plate (B2) integrated film) so that the stretching axes of the polarizing plates are orthogonal to each other. Lower side: Affixed to the polarizing plate (A2) integrated film with the polyimide layer side) with an acrylic adhesive (thickness 20 μm). The liquid crystal cell was used after being removed from a commercially available liquid crystal TV (trade name “AQUAS26 inch” manufactured by SHARP). FIG. 6 shows the results of measuring the viewing angle characteristics (color shift) of this TV with EZContrast manufactured by ELDIM. FIG. 6 shows the color shift on the chromaticity diagram when the viewing angle is tilted from the front to 80 ° in the direction of 45 ° with respect to the stretching axis of the polarizing plate.

([TAC-polarizer-TAC]-(parallel) -polyimide layer-liquid crystal cell-zeonore- (orthogonal)-[0TAC-polarizer-TAC])
2,2'-bis (3,4-dicarboxyphenyl) hexafluoropropane) and 2,2'-bis (trifluoromethyl) -4, using cyclohexanone as a solvent on a triacetyl cellulose (TAC) substrate A solution prepared by adding 15% by weight of a polyimide synthesized from 4′-diaminobiphenyl was applied to a thickness of 25 μm. Thereafter, a thin film having a thickness of about 2.7 μm was obtained by drying at 100 ° C. for 10 minutes. The obtained film was stretched 1.07 times at 150 ° C. to prepare a first optical compensation film.
When the phase difference of the obtained first optical compensation film including the base material was measured using KOBRA 21-ADH manufactured by Oji Scientific, the relationship of nx>ny> nz was satisfied, and the in-plane retardation Δnd was 35 nm, The thickness direction retardation Rth was 170 nm, and the Nz coefficient (Nz = (nx−nz) / (nx−ny)) was 4.9.
The triacetylcellulose substrate of the first optical compensation film and the polarizer, and polyvinyl alcohol so that the absorption axis of the polarizer and the slow axis (stretching axis) of the first optical compensation film are coaxial (parallel). Bonding was performed using a system adhesive (0.5 μm). Furthermore, the side opposite to the first optical compensation film of the polarizer was bonded with a triacetyl cellulose base material (thickness 40 μm) and a polyvinyl alcohol-based adhesive (0.5 μm).
Thus, a polarizing plate (A3) composed of polyimide layer-TAC-polarizer-TAC was obtained.
Next, the product name “ZEONOR” (100 μm before stretching) made by Nippon Zeon, a norbornene-based film, is 1.35 times in the X-axis direction and 135 times 1.03 times in the Y-axis direction. The film was axially stretched to produce a second optical compensation film (thickness after stretching was 83 μm).
When the retardation of the obtained second optical compensation film was measured using KOBRA 21-ADH manufactured by Oji Scientific Co., Ltd., the in-plane retardation Δnd was 130 nm, the thickness direction retardation Rth was 200 nm, and the Nz coefficient (Nz = (Nz = ( nx-nz) / (nx-ny)) was 1.5. Δnd (x) / Δnd (590) of the second optical compensation film measured with light having a wavelength x (450 nm ≦ x ≦ 700 nm) was the same as that shown in Table 1 above.
TAC (thickness 40 μm), polarizer and 0TAC were bonded together with a polyvinyl alcohol adhesive (0.5 μm) to obtain a polarizing plate (B3) comprising TAC-polarizer-0TAC.
Next, an acrylic pressure-sensitive adhesive (thickness 20 μm) is used so that the absorption axis of the polarizer of the polarizing plate (B3) and the slow axis (stretching axis) of the second optical compensation film are perpendicular to each other. ) To the 0TAC side of the polarizing plate (B3).
The two polarizing plate-integrated films obtained above are bonded to the upper and lower sides of the liquid crystal cell (upper side: polarizing plate (B3), the second optical compensation film side of the polarizing film (B3) integrated film) so that the stretching axes of the polarizing plates are orthogonal to each other, Lower side: Affixed to the polarizing plate (A3) integrated film with the polyimide layer side) with an acrylic adhesive (thickness 20 μm). The liquid crystal cell was used after being removed from a commercially available liquid crystal TV (trade name “AQUAS26 inch” manufactured by SHARP). FIG. 7 shows the results of measuring the viewing angle characteristics (color shift) of this TV with EZContrast manufactured by ELDIM. FIG. 7 shows the color shift on the chromaticity diagram when the viewing angle is tilted from the front to 80 ° in the direction of 45 ° with respect to the stretching axis of the polarizing plate.

([TAC-polarizer-TAC]-(parallel) -polyimide layer-liquid crystal cell-arton- (orthogonal)-[0TAC-polarizer-TAC])
2,2'-bis (3,4-dicarboxyphenyl) hexafluoropropane) and 2,2'-bis (trifluoromethyl) -4, using cyclohexanone as a solvent on a triacetyl cellulose (TAC) substrate A solution prepared by preparing 15% by weight of a polyimide synthesized from 4′-diaminobiphenyl was applied to a thickness of 20 μm. Then, a thin film having a thickness of about 2.5 μm was obtained by drying at 100 ° C. for 10 minutes. The obtained film was longitudinally stretched 1.05 times at 150 ° C. to prepare a first optical compensation film.
When the phase difference of the obtained first optical compensation film including the base material was measured using KOBRA 21-ADH manufactured by Oji Scientific, the relationship of nx>ny> nz was satisfied, and the in-plane retardation Δnd was 25 nm, The thickness direction retardation Rth was 150 nm, and the Nz coefficient (Nz = (nx−nz) / (nx−ny)) was 6.0.
The triacetylcellulose substrate of the first optical compensation film and the polarizer, and polyvinyl alcohol so that the absorption axis of the polarizer and the slow axis (stretching axis) of the first optical compensation film are coaxial (parallel). Bonding was performed using a system adhesive (0.5 μm). Furthermore, the side opposite to the first optical compensation film of the polarizer was bonded with a triacetyl cellulose base material (thickness 40 μm) and a polyvinyl alcohol-based adhesive (0.5 μm).
Thus, a polarizing plate (A4) composed of polyimide layer-TAC-polarizer-TAC was obtained.
Next, the product name “ARTON” (thickness before stretching: 100 μm) made by JSR, which is a norbornene-based film, is biaxially at 140 ° C. 1.3 times in the X-axis direction and 1.03 times in the Y-axis direction. The film was stretched to produce a second optical compensation film (thickness after stretching is 90 μm).
When the retardation of the obtained second optical compensation film was measured using KOBRA21-ADH manufactured by Oji Scientific Co., Ltd., the in-plane retardation Δnd was 103 nm, the thickness direction retardation Rth was 182 nm, and the Nz coefficient (Nz = (Nz = ( nx-nz) / (nx-ny)) was 1.8. Δnd (x) / Δnd (590) of the second optical compensation film measured with light of wavelength x (450 nm ≦ x ≦ 700 nm) is the same as that of Zeonore, which is the same norbornene-based film, that is, as described above. It was the same as Table 1.
TAC (thickness 40 μm), polarizer and 0TAC were bonded together with a polyvinyl alcohol adhesive (0.5 μm) to obtain a polarizing plate (B4) composed of TAC-polarizer-0TAC.
Next, an acrylic pressure-sensitive adhesive (thickness 20 μm) is used so that the absorption axis of the polarizer of the polarizing plate (B4) and the slow axis (stretching axis) of the second optical compensation film are perpendicular to each other. ) To the 0TAC side of the polarizing plate (B4).
The two polarizing plate-integrated films obtained above are bonded to the upper and lower sides of the liquid crystal cell (upper side: polarizing plate (B4) integrated film) on the second optical compensation film side so that the stretching axes of the polarizing plates are orthogonal to each other, Lower side: Affixed to the polarizing plate (A4) integrated film on the polyimide layer side) with an acrylic pressure-sensitive adhesive (thickness 20 μm). The liquid crystal cell was used after being removed from a commercially available liquid crystal TV (trade name “AQUAS26 inch” manufactured by SHARP). As a result of measuring the viewing angle characteristics (color shift) of this TV with EZContrast manufactured by ELDIM, the results almost the same as those of Example 2 were obtained.

[Comparative Example 1]
([TAC-polarizer-TAC]-(orthogonal) -polyimide layer-liquid crystal cell-SEG1224DU (manufactured by Nitto Denko))
2,2'-bis (3,4-dicarboxyphenyl) hexafluoropropane) and 2,2'-bis (trifluoromethyl) -4,4'- by using cyclohexanone as a solvent on a triacetyl cellulose substrate A solution prepared by preparing 15% by weight of a polyimide synthesized from diaminobiphenyl was applied to a thickness of 35 μm. Then, the thin film about 3.5 micrometers thick was obtained by drying for 10 minutes at 100 degreeC. The obtained film was stretched 1.2 times at 150 ° C. to prepare an optical compensation film (C1-1).
When the phase difference including the base material of the obtained optical compensation film (C1-1) was measured using KOBRA 21-ADH manufactured by Oji Scientific Co., the relationship of nx>ny> nz was satisfied, and the in-plane retardation Δnd was The thickness direction retardation Rth was 250 nm and the Nz coefficient (Nz = (nx−nz) / (nx−ny)) was 4.2.
The polyvinyl alcohol so that the absorption axis of the polarizer and the slow axis (stretching axis) of the optical compensation film (C1-1) are orthogonal to each other. Bonding was performed using a system adhesive (0.5 μm). Furthermore, the side opposite to the optical compensation film (C1-1) of the polarizer was bonded with a triacetylcellulose substrate (thickness 40 μm) and a polyvinyl alcohol-based adhesive (0.5 μm).
Thus, a polarizing plate (A5) composed of polyimide layer-TAC-polarizer-TAC was obtained.
The above-obtained polarizing plate integrated film and the polarizing plate SEG1224DU made by Nitto Denko are placed above and below the liquid crystal cell so that the stretching axes of the polarizing plates are perpendicular to each other (upper side: polarizing plate SEG1224DU made by Nitto Denko, lower side: polarizing plate (A5 ) Attached to the polyimide film side of the integral film) with an acrylic pressure-sensitive adhesive (thickness 20 μm). The liquid crystal cell was used after being removed from a commercially available liquid crystal TV (trade name “AQUAS26 inch” manufactured by SHARP). FIG. 8 shows the results of measuring the viewing angle characteristics (color shift) of this TV with EZContrast manufactured by ELDIM. FIG. 8 shows the color shift on the chromaticity diagram when the viewing angle is tilted from the front to 80 ° in the direction of 45 ° with respect to the stretching axis of the polarizing plate.

[Comparative Example 2]
([TAC-polarizer-0TAC]-(orthogonal) -N-TAC-liquid crystal cell- [0TAC-polarizer-TAC])
Konica N-TAC (trade name: KC8NYACS, cellulose acetate propionate film, Tg = about 145 ° C., thickness 80 μm) is laminated with an adhesive so that the stretching axis is coaxial, and an optical compensation film ( C2-1) was prepared.
When the retardation of the obtained optical compensation film (C2-1) was measured using KOBRA21-ADH manufactured by Oji Scientific, the relationship of nx>ny> nz was satisfied, the in-plane retardation Δnd was 80 nm, and the thickness direction The phase difference Rth was 300 nm, and the Nz coefficient (Nz = (nx−nz) / (nx−ny)) was 3.8.
TAC (thickness 40 μm), polarizer and 0TAC were bonded together with a polyvinyl alcohol adhesive (0.5 μm) to obtain a polarizing plate (A6) comprising TAC-polarizer-0TAC.
Next, the acrylic compensation film (C2-1) is coated with an acrylic adhesive so that the absorption axis of the polarizer of the polarizing plate (A6) and the slow axis (stretching axis) of the optical compensation film (C2-1) are orthogonal to each other. It bonded together to the 0TAC side of the polarizing plate (A6) through the agent (thickness 20 micrometers).
On the other hand, TAC (thickness 40 μm), polarizer and 0TAC were bonded together with a polyvinyl alcohol adhesive (0.5 μm) to obtain a polarizing plate (B6) comprising TAC-polarizer-0TAC.
The two polarizing plate-integrated films obtained above are bonded to the upper and lower sides (upper side: polarizing plate (B6) integrated film of the polarizing plate (B6), and the lower side: polarizing plate so that the stretching axes of the polarizing plates are orthogonal to each other. (A6) Bonded to the optical compensation film (C2-1) side of the integral film) with an acrylic pressure-sensitive adhesive (thickness 20 μm). The liquid crystal cell was used after being removed from a commercially available liquid crystal TV (trade name “AQUAS26 inch” manufactured by SHARP). FIG. 9 shows the results of measuring the viewing angle characteristics (color shift) of this TV with EZContrast manufactured by ELDIM. In FIG. 9, the color shift in the case where the viewing angle is tilted from the front to 80 ° in the direction of 45 ° with respect to the stretching axis of the polarizing plate is shown on the chromaticity diagram.

[Comparative Example 3]
([TAC-polarizer-0TAC]-(orthogonal) -zeonore-liquid crystal cell-SEG1224DU (manufactured by Nitto Denko))
A product name “ZEONOR” (100 μm before stretching) made by Nippon Zeon, which is a norbornene-based film, was biaxially stretched at 135 ° C. by 1.5 times in the X-axis direction and 1.05 times in the Y-axis direction. An optical compensation film (C3-1) (thickness after stretching was 84 μm) was prepared.
When the retardation of the obtained optical compensation film (C3-1) was measured using KOBRA21-ADH manufactured by Oji Scientific, the relationship of nx>ny> nz was satisfied, the in-plane retardation Δnd was 60 nm, and the thickness direction The phase difference Rth was 250 nm, and the Nz coefficient (Nz = (nx−nz) / (nx−ny)) was 4.2.
TAC (thickness 40 μm), polarizer and 0TAC were bonded together with a polyvinyl alcohol adhesive (0.5 μm) to obtain a polarizing plate (A7) comprising TAC-polarizer-0TAC.
Next, the acrylic compensation film (C3-1) is coated with an acrylic adhesive so that the absorption axis of the polarizer of the polarizing plate (A7) and the slow axis (stretching axis) of the optical compensation film (C3-1) are orthogonal to each other. It bonded together to the 0TAC side of the polarizing plate (A7) through the agent (thickness 20 micrometers).
The upper and lower sides of the liquid crystal cell (the upper side: Nitto Denko polarizing plate SEG1224DU, the lower side: polarizing plate (A7) so that the polarizing plate integrated film obtained above and the polarizing plate SEG1224DU made by Nitto Denko are orthogonal to each other. ) Attached to the optical compensation film (C3-1) side of the integral film) with an acrylic pressure-sensitive adhesive (thickness 20 μm). The liquid crystal cell was used after being removed from a commercially available liquid crystal TV (trade name “AQUAS26 inch” manufactured by SHARP). FIG. 10 shows the results of measuring the viewing angle characteristics (color shift) of this TV with EZContrast manufactured by ELDIM. FIG. 10 shows a color shift on the chromaticity diagram when the viewing angle is tilted from the front to 80 ° in the direction of 45 ° with respect to the stretching axis of the polarizing plate.

[Comparative Example 4]
([TAC-polarizer-0TAC]-(parallel) -polyimide layer-liquid crystal cell-polyimide layer- (orthogonal)-[0TAC-polarizer-TAC])
TAC (thickness 40 μm), polarizer and 0TAC are bonded together with a polyvinyl alcohol adhesive (0.5 μm), and two polarizing plates ((A8) and (B8)) made of TAC-polarizer-0TAC are produced. did.
Next, from 2,2′-bis (3,4-dicarboxyphenyl) hexafluoropropane) and 2,2′-bis (trifluoromethyl) -4,4′-diaminobiphenyl) using cyclohexanone as a solvent A solution prepared by synthesizing 15% by weight of the synthesized polyimide was applied to a trade name “ZEONOR” manufactured by Nippon Zeon Co., Ltd. with a thickness of 25 μm (the thickness before stretching was 100 μm), and after drying at 100 ° C. for 10 minutes, a solution was obtained. The resulting film was stretched 150% at 140 ° C. Only the polyimide layer is bonded to the 0TAC side of the polarizing plate (A8) so that the absorption axis of the polarizer and the slow axis (stretching axis) of the polyimide layer are coaxial (parallel). An optical compensation film (C4-1) was prepared by transferring using an agent.
On the other hand, only the polyimide layer is bonded to the 0TAC side of the polarizing plate (B8) so that the absorption axis of the polarizer and the slow axis (stretching axis) of the polyimide layer are orthogonal to each other. An optical compensation film (C4-2) was prepared by transferring using an agent.
When the phase difference of the polyimide layer alone was measured using KOBRA21-ADH manufactured by Oji Scientific, the relationship of nx>ny> nz was satisfied, the in-plane retardation Δnd was 18 nm, the thickness direction retardation Rth was 137 nm, and the Nz coefficient (Nz = (nx−nz) / (nx−ny)) was 7.6.
The two optical compensation films (C4-1) and (C4-2) obtained above are vertically (upper side: optical compensation film (C4-2) of the liquid crystal cell so that the stretching axes of the polarizing plates are orthogonal to each other. The polyimide layer side was bonded together, and the lower side: the polyimide layer side of the optical compensation film (C4-1) was bonded with an acrylic adhesive (thickness 20 μm). The liquid crystal cell was used after being removed from a commercially available liquid crystal TV (trade name “AQUAS26 inch” manufactured by SHARP). FIG. 11 shows the results of measuring the viewing angle characteristics (color shift) of this TV with EZContrast manufactured by ELDIM. In FIG. 11, the color shift when the viewing angle is tilted from the front to 80 ° in the direction of 45 ° with the stretching axis of the polarizing plate is shown on the chromaticity diagram.

[Comparative Example 5]
([TAC-Polarizer-0TAC]-(Parallel) -Zeonor-Liquid Crystal Cell-Zeonor- (Parallel)-[0TAC-Polarizer-TAC])
The product name “ZEONOR” (100 μm before stretching) made by Nippon Zeon, a norbornene-based film, was biaxially stretched at 140 ° C. 1.2 times in the X-axis direction and 1.1 times in the Y-axis direction. An optical compensation film (C5-1) (thickness after stretching was 91 μm) was prepared.
When the retardation of the obtained optical compensation film (C5-1) was measured using KOBRA21-ADH manufactured by Oji Scientific, the relationship of nx>ny> nz was satisfied, the in-plane retardation Δnd was 23 nm, and the thickness direction The phase difference Rth was 143 nm, and the Nz coefficient (Nz = (nx−nz) / (nx−ny)) was 6.2.
TAC (thickness 40 μm), polarizer and 0TAC were bonded together with a polyvinyl alcohol adhesive (0.5 μm) to obtain a polarizing plate (A9) composed of TAC-polarizer-0TAC.
Next, the optical compensation film (C5-1) is so arranged that the absorption axis of the polarizer of the polarizing plate (A9) and the slow axis (stretching axis) of the optical compensation film (C5-1) are coaxial (parallel). Then, it was bonded to the 0TAC side of the polarizing plate (A9) through an acrylic adhesive (thickness 20 μm).
Next, a product name “ZEONOR” (Zeonor) (manufactured by ZEON Corporation), which is a norbornene-based film, is stretched at a fixed end of 1.5 times in the X-axis direction at 145 ° C. to obtain an optical compensation film (C5 -2) (The thickness after stretching is 80 μm).
When the retardation of the obtained optical compensation film (C5-2) was measured using KOBRA21-ADH manufactured by Oji Scientific, the relationship of nx>ny> nz was satisfied, the in-plane retardation Δnd was 100 nm, and the thickness direction The phase difference Rth was 180 nm, and the Nz coefficient (Nz = (nx−nz) / (nx−ny)) was 1.8.
TAC (thickness 40 μm), polarizer and 0TAC were bonded together with a polyvinyl alcohol adhesive (0.5 μm) to obtain a polarizing plate (B9) comprising TAC-polarizer-0TAC.
Next, the optical compensation film (C5-2) is arranged so that the absorption axis of the polarizer of the polarizing plate (B9) and the slow axis (stretching axis) of the optical compensation film (C5-2) are coaxial (parallel). Then, it was bonded to the 0TAC side of the polarizing plate (B9) through an acrylic adhesive (thickness 20 μm).
Attach the upper and lower sides of the liquid crystal cell (upper side: polarizing plate (B9): optical compensation film (C5-2) side of the two polarizing plate integrated films obtained above so that the polarizing axes of the polarizing plates are orthogonal to each other. The lower side: the polarizing plate (A9) integrated film was bonded to the optical compensation film (C5-1) side) with an acrylic pressure-sensitive adhesive (thickness 20 μm). The liquid crystal cell was used after being removed from a commercially available liquid crystal TV (trade name “AQUAS26 inch” manufactured by SHARP). FIG. 12 shows the results of measuring the viewing angle characteristics (color shift) of this TV with EZContrast manufactured by ELDIM. FIG. 12 shows a color shift on the chromaticity diagram when the viewing angle is tilted from the front to 80 ° in the direction of 45 ° with respect to the stretching axis of the polarizing plate.

[Comparative Example 6]
([TAC-polarizer-0TAC]-(parallel) -polyimide layer- (orthogonal) -zeonore-liquid crystal cell-SEG1224DU (manufactured by Nitto Denko))
A norbornene film having a thickness of 100 μm (trade name “ZEONOR” manufactured by Nippon Zeon Co., Ltd.) is stretched 180% at 175 ° C. to obtain a stretched film having a thickness of 60 μm, and then polyimide is coated thereon and longitudinally stretched. An optical compensation film (C6-1) was obtained.
When the retardation of the obtained optical compensation film (C6-1) was measured using KOBRA21-ADH manufactured by Oji Scientific, the relationship of nx>ny> nz was satisfied, the in-plane retardation Δnd was 64 nm, and the thickness direction The phase difference Rth was 265 nm, and the Nz coefficient (Nz = (nx−nz) / (nx−ny)) was 4.1.
TAC (thickness 40 μm), polarizer and 0TAC were bonded together with a polyvinyl alcohol adhesive (0.5 μm) to obtain a polarizing plate (A10) comprising TAC-polarizer-0TAC.
Next, in the optical compensation film (C6-1), the absorption axis of the polarizer of the polarizing plate (A10) and the slow axis (stretching axis) of the polyimide layer of the optical compensation film (C6-1) are coaxial (parallel). Thus, it bonded together to the 0TAC side of a polarizing plate (A10) through the acrylic adhesive (thickness 20 micrometers).
The upper and lower sides of the liquid crystal cell (the upper side: Nitto Denko polarizing plate SEG1224DU, the lower side: polarizing plate (A10) so that the polarizing plate integrated film obtained above and the polarizing plate SEG1224DU made by Nitto Denko are orthogonal to each other. ) Attached to the ZEONOR layer side of the integral film) with an acrylic adhesive (thickness 20 μm). The liquid crystal cell was used after being removed from a commercially available liquid crystal TV (trade name “AQUAS26 inch” manufactured by SHARP). FIG. 13 shows the results of measuring the viewing angle characteristics (color shift) of this TV with EZContrast manufactured by ELDIM. FIG. 13 shows the color shift on the chromaticity diagram when the viewing angle is tilted from the front to 80 ° in the direction of 45 ° with respect to the stretching axis of the polarizing plate.

  As is apparent from FIGS. 5 to 13, it can be seen that the liquid crystal panels obtained in Examples 1 to 4 have significantly better color shift than the liquid crystal panels obtained in Comparative Examples 1 to 6.

  The liquid crystal panel of the present invention and the liquid crystal display device including the liquid crystal panel can be suitably applied to a liquid crystal television, a mobile phone, and the like.

It is a schematic sectional drawing of the liquid crystal panel by preferable embodiment of this invention. When the liquid crystal display device of this invention employ | adopts a VA mode liquid crystal cell, it is a schematic sectional drawing explaining the orientation state of the liquid crystal molecule of a liquid crystal layer. When the liquid crystal display device of this invention employ | adopts the liquid crystal cell of OCB mode, it is a schematic sectional drawing explaining the orientation state of the liquid crystal molecule of a liquid crystal layer. It is a schematic diagram explaining the azimuth angle and polar angle in the measurement of a color shift. It is XY chromaticity diagram which shows the measurement result of the color shift about the liquid crystal panel of Example 1 of this invention when changing an azimuth angle to a 45 degree direction and a polar angle from 0 to 80 degrees. It is XY chromaticity diagram which shows the measurement result of a color shift about the liquid crystal panel of Example 2 of this invention when changing an azimuth angle to a 45 degree direction and a polar angle from 0 to 80 degrees. It is XY chromaticity diagram which shows the measurement result of a color shift about the liquid crystal panel of Example 3 of this invention when changing an azimuth angle in a 45 degree direction and a polar angle from 0 to 80 degrees. It is an XY chromaticity diagram showing the measurement result of the color shift when the azimuth angle is changed to 45 ° and the polar angle is changed from 0 ° to 80 ° for the liquid crystal panel of Comparative Example 1. It is an XY chromaticity diagram showing the measurement result of the color shift when the azimuth angle is changed to 45 ° and the polar angle is changed from 0 ° to 80 ° for the liquid crystal panel of Comparative Example 2. It is an XY chromaticity diagram showing the measurement result of the color shift when the azimuth angle is changed to 45 ° and the polar angle is changed from 0 ° to 80 ° for the liquid crystal panel of Comparative Example 3. It is an XY chromaticity diagram showing the measurement result of color shift when the azimuth angle is changed to 45 ° and the polar angle is changed from 0 ° to 80 ° for the liquid crystal panel of Comparative Example 4. FIG. 10 is an XY chromaticity diagram showing measurement results of color shift when the azimuth angle is changed to 45 ° and the polar angle is changed from 0 ° to 80 ° for the liquid crystal panel of Comparative Example 5; FIG. 16 is an XY chromaticity diagram showing measurement results of color shift when the azimuth angle is changed to 45 ° and the polar angle is changed from 0 ° to 80 ° for the liquid crystal panel of Comparative Example 6;

Explanation of symbols

30 First Polarizer 40 Liquid Crystal Cell 50 Second Polarizer 60 First Optical Compensation Layer 70 Second Optical Compensation Layer 100 Liquid Crystal Panel

Claims (3)

Comprising a first polarizer, a first optical compensation layer, a liquid crystal cell, a second optical compensation layer, and a second polarizer in this order,
The first polarizer and the first optical compensation layer are disposed on the backlight side of the liquid crystal cell;
The liquid crystal cell is in VA mode or OCB mode;
The first optical compensation layer satisfies the formulas (1) and (2), the second optical compensation layer satisfies the formulas (1) and (3),
The slow axis of the first optical compensation layer is parallel to the absorption axis of the first polarizer, and the slow axis of the second optical compensation layer is orthogonal to the absorption axis of the second polarizer. LCD panel:
nx>ny> nz (1)
2 ≦ (nx−nz) / (nx−ny) ≦ 20 (2)
0.97 <Δnd (x) / Δnd (590) <1.05 (3)
nx is the refractive index in the slow axis direction, ny is the refractive index in the fast axis direction, nz is the refractive index in the thickness direction, and Δnd (x) is an in-plane measured with light of wavelength x (450 nm ≦ x ≦ 700 nm). The phase difference value, Δnd (590), indicates an in-plane phase difference value measured with light having a wavelength of 590 nm. Material forming the first optical compensation layer is at least one non-liquid crystalline materials polyamide, polyimide, polyester, polyether ketone is selected from the group consisting of polyamideimide and polyesterimide, according to claim 1, A liquid crystal panel as described in 1. A liquid crystal display device comprising the liquid crystal panel according to claim 1 .

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