JP2017129829A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display device using a luminance improving film having high productivity.SOLUTION: The liquid crystal display device includes an upper polarizer 1, a liquid crystal cell 2, a lower polarizer 3, an optical rotation film 6, and a luminance improving film 7, in the described order. An angle α formed by a transmission axis of the lower polarizer and a transmission axis of the luminance improving film is 30° to 150°; the optical rotation film comprises a support 4 and an optical rotation element 5; the optical rotation film shows a dimensional change rate S satisfying |S|≤0.5, after heat-treated at 80°C for 24 hours; the support shows a retardation Re(550) of 0 nm to 10 nm at a wavelength of 550 nm; the support has a film thickness of 10 μm to 100 μm; and the optical rotation element and the luminance improving film are arranged via an adhesive or a pressure-sensitive adhesive 8.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a liquid crystal display device.

  Flat panel displays such as liquid crystal display devices (hereinafter also referred to as LCDs) have low power consumption and are increasingly used as space-saving image display devices year by year. In the flat panel display market in recent years, there has been development for power saving, high definition, and color reproducibility improvement as LCD performance improvement in both large-sized applications mainly for TV applications and small and medium-sized applications such as tablet PCs and smartphones. Progressing.

  With the power saving of the backlight, it has been proposed to provide a brightness enhancement film between the backlight and the backlight side polarizing plate. The brightness enhancement film is an optical element that transmits only light that vibrates in a specific polarization direction and reflects light that vibrates in another polarization direction among incident light that vibrates in all directions.

  In Patent Document 1, by combining an optical sheet member (such as DBEF (registered trademark) (Dual Brightness Enhancement Film)) between a backlight and a backlight-side polarizing plate, light from BL can be obtained through light recycling. A technique for improving the luminance while improving the utilization factor and saving power of the backlight is described.

In general, a commercially available liquid crystal display uses DBEF as disclosed in Patent Document 1, but DBEF has a fast axis parallel to the roll conveyance direction because of its manufacturing method. The polarization transmission axis is parallel to the transport direction. On the other hand, since a commercially available PVA type polarizer has an absorption axis parallel to the roll conveyance direction, there is a problem that light cannot be transmitted when DBEF and a PVA type polarizer are bonded with a roll-to-roll. is there.
Therefore, after punching out DBEF, there is a current situation in which it is necessary to take a method with very poor productivity, in which the DBEF is rotated by 90 ° and then bonded to the polarizing plate.

Japanese Patent No. 3448626 US Pat. No. 9,164,212 JP 2005-504333 Gazette

  In contrast, Patent Document 2 proposes polarization axis conversion using a λ / 2 film. On the other hand, as shown in Patent Document 2, in the form in which the rod-like liquid crystal is horizontally arranged in the 45 ° direction, it cannot be applied to the TN cell, and the color change at the oblique viewing angle is not excellent even in the panel such as IPS and VA. I understood.

  The reason why it cannot be applied to the TN cell is that the angle formed between the transmission axis of the polarizing plate and the transmission axis of the brightness enhancement film is not 90 ° but 45 °, and rotating the polarized light in the 45 ° direction is λ / In principle, it cannot be realized with two films.

  On the other hand, for example, Patent Document 3 considers the use of an optical rotatory element, and a method of forming an alignment layer on the surface of the polarizing element and aligning and fixing the liquid crystal material has been proposed. On the other hand, as described in Patent Document 3, in the form of coating directly on the polarizing element, it is necessary to perform the coating process twice on a very expensive brightness enhancement film, which significantly increases the production cost. There was a problem.

  Furthermore, it was necessary to align the alignment direction of the liquid crystal material in the direction of 90 ° with respect to the conveyance direction, and it was also found that the production line having a conveyance speed cannot be substantially manufactured.

  Therefore, an object of the present invention is to provide a liquid crystal display device using a brightness enhancement film with high productivity.

  The inventors of the present invention have a liquid crystal display device having a specific layer configuration by using an optical rotation film having a specific layer configuration and physical properties, so that a liquid crystal that does not deteriorate productivity even when a brightness enhancement film is used. It has been found that the display device can be.

  Moreover, it turned out that the curvature of a liquid crystal panel after a wet heat durability test and circular unevenness performance improve by setting it as the layer structure of this invention. The details of the mechanism are not clear, but the water that has passed through the brightness enhancement film is absorbed or blocked by the support, so that the water cannot reach the lower polarizer and the above performance is improved. I guess.

  In addition, with the recent increase in definition of liquid crystal cells, minute scratches resulting from rubbing between the lower polarizing plate and the brightness enhancement film have become a problem. On the other hand, it was found that this scratch can be improved by employing the layer structure of the present invention.

  Furthermore, in the state of a polarizing plate in which the lower polarizer, the optical rotatory film, and the brightness enhancement film are integrated, when punched according to the size of the liquid crystal cell, the optical rotatory film is punched only in the form including the support as in the present invention. It was also found that the aptitude improved.

  In particular, it was also found that this effect is remarkable in a configuration in which the polarization transmission axis of the brightness enhancement film and the polarization transmission axis of the polarizer are arranged at 90 °.

  Although the detailed mechanism is not clear, the present inventors presume as follows. In general, it is said that a polymer material becomes brittle as the degree of orientation increases. By having an optical rotatory element that rotates polarized light in between, a highly oriented polarizer and a highly oriented brightness enhancement film can be laminated with their orientation directions orthogonal to each other, and the brittle direction is dispersed. It is presumed that the substrate disposed between the brightness enhancement film and the polarizer is improved by the interaction of acting as a cushion.

  That is, it has been found that the above-described problem can be achieved by the following configuration.

[1] An upper polarizer, a liquid crystal cell, a lower polarizer, an optical rotation film, and a brightness enhancement film are provided in this order, and an angle α formed by the transmission axis of the lower polarizer and the transmission axis of the brightness enhancement film is 30. The optical rotation film is an optical rotation film including a support and an optical rotation element, and the dimensional change rate S after heat treatment at 80 ° C. for 24 hours satisfies | S | ≦ 0.5. The retardation Re (550) at a wavelength of 550 nm of the support is 0 nm to 10 nm, the thickness of the support is 10 μm to 100 μm, and the optical rotation element and the brightness enhancement film are interposed via an adhesive or a pressure-sensitive adhesive. Liquid crystal display device.
[2] The liquid crystal display device according to [1], wherein the optical rotator is an optical rotator including a retardation layer including a liquid crystal compound.
[3] The liquid crystal display device according to [2], wherein the optical rotator is an optical rotator including a retardation layer including a chiral agent.
[4] The liquid crystal display device according to [2] or [3], wherein the liquid crystal compound is a rod-like liquid crystal compound.
[5] The liquid crystal display device according to [2] or [3], wherein the optical rotator includes a laminate of a retardation layer containing a rod-like liquid crystalline compound and a retardation layer containing a discotic liquid crystalline compound.
[6] The liquid crystal display device according to any one of [1] to [5], wherein the optical rotator is an optical rotator that rotates polarized light incident on the optical rotator within a range of α ± 5 °.
[7] The liquid crystal display device according to [4] or [6], wherein the average major axis direction of molecules on the lower polarizer side of the optical rotator and the absorption axis of the lower polarizer are parallel.
[8] The liquid crystal display device according to any one of [1] to [7], wherein the retardation Re (550) at a wavelength of 550 nm of the optical rotatory film is 300 nm to 700 nm.
[9] The liquid crystal display device according to any one of [1] to [8], wherein the optical rotation element has a film thickness of 1 μm to 5 μm.

  ADVANTAGE OF THE INVENTION According to this invention, the liquid crystal display device using a brightness improvement film with high productivity can be provided.

It is a typical perspective view which shows the example of embodiment of the liquid crystal display device of this invention.

Hereinafter, the present invention will be described in detail.
The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments.
In the present specification, a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.
In this specification, the polarizing plate means a polarizing plate having a polarizing plate protective layer or a functional layer disposed on at least one of the polarizers, and the polarizer and the polarizing plate are used separately.
Further, in this specification, parallel and orthogonal do not mean parallel or orthogonal in a strict sense, but mean a range of ± 5 ° from parallel or orthogonal.

《Retardation》
In the present invention, Re (λ) and Rth (λ) respectively represent in-plane retardation and retardation in the thickness direction at a wavelength λ. Unless otherwise specified, the wavelength λ is 590 nm.

In the present invention, Re (λ) and Rth (λ) are values measured at a wavelength λ in AxoScan OPMF-1 (manufactured by Optoscience). By inputting the average refractive index ((Nx + Ny + Nz) / 3) and film thickness (d (μm)) in AxoScan,
Slow axis direction (°)
Re (λ) = R0 (λ)
Rth (λ) = (Nz− (Nx + Ny) / 2) × d is calculated.

<< refractive index >>
In the present invention, the refractive indexes Nx, Ny, and Nz are measured using an Abbe refractometer (NAR-4T, manufactured by Atago Co., Ltd.) and a sodium lamp (λ = 589 nm) as a light source. Moreover, when measuring wavelength dependence, it can measure in combination with an interference filter in multiwavelength Abbe refractometer DR-M2 (made by Atago Co., Ltd.).

  In addition, values in polymer handbooks (John Wiley & Sons, Inc.) and catalogs of various optical films can be used.

《Polarization rotation angle》
In the present invention, the rotation angle of polarized light is a value of Circular Retention calculated using AxoScan OPMF-1 (manufactured by Optoscience).

《Rotation angle of liquid crystalline compound》
In the present invention, the rotation angle of the liquid crystal compound is such that when the optical rotatory element contains the liquid crystal compound, an in-plane slow axis on one surface side and an in-plane slow axis on the opposite surface side. It is expressed as an angle formed by. The in-plane slow axis on each surface side is measured using AxoScan OPMF-1 (manufactured by Optoscience) and using the attached device analysis software.

<Liquid crystal display device>
FIG. 1 is a schematic cross-sectional view showing an example of an embodiment of a liquid crystal display device of the present invention. The liquid crystal display device 10 of the present invention has an upper polarizer 1, a liquid crystal cell 2, a lower polarizer 3, an optical rotation film 6 and a brightness enhancement film 7 in this order. Here, the angle α formed by the transmission axis of the lower polarizer 3 and the transmission axis of the brightness enhancement film 7 is 30 ° to 150 °. The optical rotatory film 6 includes a support 4 and an optical rotator 5, and the optical rotator 5 and the brightness enhancement film 7 are arranged with an adhesive or a pressure-sensitive adhesive 8 interposed therebetween.

[Polarizer]
In the present invention, the upper polarizer on the viewing side of the liquid crystal display device and the lower polarizer on the opposite side to the viewing side across the liquid crystal cell may be collectively referred to as a polarizer used in the present invention. .

  The polarizer used in the present invention is not particularly limited as long as it is a so-called linear polarizer having a function of converting natural light into specific linearly polarized light. The polarizer is not particularly limited, but an absorptive polarizer can be used.

  The material of the polarizer used in the present invention is not particularly limited, and a commonly used polarizer can be used. For example, an iodine polarizer, a dye polarizer using a dichroic dye, and a polyene Any of the system polarizers can be used.

  The polarizer used in the present invention may be used in the form of a polarizing plate in which a protective layer is bonded to at least one side. In the present invention, the viewing side protective film of the upper polarizer is the first protective film, the protective film opposite to the viewing side of the upper polarizer is the second protective film, and the viewing side protective film of the lower polarizer is the first. The protective film 3 and the protective film on the side opposite to the viewing side of the lower polarizer may be referred to as a fourth protective film. Moreover, the 1st-4th protective film may be named generically, and may be called the protective film used for this invention.

  The protective film used in the present invention may also serve as various functional layers. Various functional layers include various known layers such as an antireflection layer and an optically anisotropic layer. Moreover, the 4th protective film may serve as the optical rotation film used for this invention, and a brightness improvement film.

  The protective film used in the present invention may not be used depending on various applications. That is, the liquid crystal cell and the polarizer used in the present invention may be directly bonded without using the second and third protective films.

{Protective film}
As the protective film used in the present invention, various polymer films such as a polyester film, an acrylic film, and a cellulose acylate film can be used.

<Polyester film>
Examples of the polyester used in the polyester film used in the present invention include polyethylene terephthalate, polyethylene isophthalate, polyethylene 2,6-naphthalate, polybutylene terephthalate, and 1,4-cyclohexanedimethylene terephthalate. Two or more of them may be used. Of these, polyethylene terephthalate is preferably used.

Polyethylene terephthalate is a polyester having a structural unit derived from terephthalic acid as a dicarboxylic acid component and a structural unit derived from ethylene glycol as a diol component, and 80 mol% or more of all repeating units are preferably ethylene terephthalate. The structural unit derived from other copolymerization components may be included. Other copolymer components include isophthalic acid, p-β-oxyethoxybenzoic acid, 4,4′-dicarboxydiphenyl, 4,4′-dicarboxybenzophenone, bis (4-carboxyphenyl) ethane, adipic acid , Dicarboxylic acid components such as sebacic acid, 5-sodium sulfoisophthalic acid, 1,4-dicarboxycyclohexane, propylene glycol, butanediol, neopentyl glycol, diethylene glycol, cyclohexanediol, ethylene oxide adduct of bisphenol A, polyethylene glycol And diol components such as polypropylene glycol and polytetramethylene glycol. These dicarboxylic acid components and diol components can be used in combination of two or more if necessary. It is also possible to use an oxycarboxylic acid such as p-oxybenzoic acid in combination with the carboxylic acid component or diol component. As another copolymer component, a dicarboxylic acid component and / or a diol component containing a small amount of an amide bond, a urethane bond, an ether bond, a carbonate bond, or the like may be used. Polyethylene terephthalate can be produced by a direct polymerization method in which terephthalic acid and ethylene glycol and, if necessary, other dicarboxylic acid and / or other diol are directly reacted, dimethyl ester of terephthalic acid and ethylene glycol, and necessary Depending on the above, any production method such as a so-called transesterification method in which a dimethyl ester of another dicarboxylic acid and / or another diol is transesterified can be applied.

  The mass ratio of the polyester to the whole polyester film is usually 50 mass% or more, preferably 70 mass% or more, more preferably 90 mass% or more.

  Moreover, in this invention, since a polyester film generally has high intrinsic birefringence, it is hard to receive the optical influence, It is preferable to use it as a 1st protective film.

<Acrylic film>
The (meth) acrylic resin used for the acrylic film used in the present invention is not particularly limited, and any appropriate (meth) acrylic resin can be adopted. For example, poly (meth) acrylic acid ester such as polymethyl methacrylate, methyl methacrylate- (meth) acrylic acid copolymer, methyl methacrylate- (meth) acrylic acid ester copolymer, methyl methacrylate-acrylic acid ester -(Meth) acrylic acid copolymer, (meth) acrylic acid methyl-styrene copolymer (MS resin, etc.), polymer having an alicyclic hydrocarbon group (for example, methyl methacrylate-cyclohexyl methacrylate copolymer) And methyl methacrylate- (meth) acrylate norbornyl copolymer).
Preferably, it is poly (meth) acrylic acid ester such as poly (meth) acrylic acid methyl, and poly (meth) acrylic acid C1-6 alkyl ((meth) acrylic acid alkyl ester polymer having 1 to 6 carbon atoms). ) Is more preferable. More preferably, a methyl methacrylate resin containing methyl methacrylate as a main component (50 to 100% by mass, preferably 70 to 100% by mass) is used.

  Specific examples of the (meth) acrylic resin include, for example, Acrypet VH and Acrypet VRL20A manufactured by Mitsubishi Rayon Co., Ltd., and a high Tg (meth) acrylic resin obtained by intramolecular crosslinking or intramolecular cyclization reaction. .

  In the present invention, the (meth) acrylic resin has a (meth) acrylic resin having a glutaric anhydride structure and a lactone ring structure in that it has high heat resistance, high transparency, and high mechanical strength ( A (meth) acrylic resin and a (meth) acrylic resin having a glutarimide structure are preferred.

As the (meth) acrylic resin having a glutaric anhydride structure, the glutaric anhydride structure described in JP-A-2006-283013, JP-A-2006-335902, JP-A-2006-274118, or the like is used. The (meth) acrylic resin which has is mentioned.
Examples of the (meth) acrylic resin having a lactone ring structure include JP 2000-230016, JP 2001-151814, JP 2002-120326, JP 2002-254544, and JP 2005. Examples thereof include (meth) acrylic resins having a lactone ring structure described in Japanese Patent No. 146084.
Examples of the (meth) acrylic resin having a glutarimide structure include JP-A-2006-309033, JP-A-2006-317560, JP-A-2006-328329, JP-A-2006-328334, and JP-A-2006. No. 337491, JP-A 2006-337492, JP-A 2006-337493, JP-A 2006-337569, JP-A 2007-009182, etc. Resin.

  The (meth) acrylic resin has a Tg (glass transition temperature) of preferably 115 ° C. or higher, more preferably 120 ° C. or higher, still more preferably 125 ° C. or higher, and particularly preferably 130 ° C. or higher. The said (meth) acrylic-type resin film can become the thing excellent in durability by including (meth) acrylic-type resin whose Tg (glass transition temperature) is 115 degreeC or more as a main component. Although the upper limit of Tg of the said (meth) acrylic-type resin is not specifically limited, From viewpoints of a moldability etc., Preferably it is 170 degrees C or less.

  In the present invention, the acrylic film is generally a low birefringence material in general, and therefore can be applied to a portion where the influence of optical characteristics is large. That is, it is preferable to use as the second to third protective films. Moreover, since an acrylic film shows the outstanding hardness, it is also preferable to use it as a 1st protective film.

[Liquid crystal cell]
The liquid crystal cell used in the present invention is preferably a VA (Virtual Alignment) mode, an OCB (Optical Compensated Bend) mode, an IPS (In-Placed Switching) mode, or a TN (Twisted Nematic). Is not to be done.

  In a TN mode liquid crystal cell, rod-like liquid crystal molecules are substantially horizontally aligned when no voltage is applied, and are twisted and aligned at 60 to 120 °. The TN mode liquid crystal cell is most frequently used as a color TFT liquid crystal display device, and is described in many documents.

  In a VA mode liquid crystal cell, rod-like liquid crystalline molecules are aligned substantially vertically when no voltage is applied. The VA mode liquid crystal cell includes (1) a narrowly defined VA mode liquid crystal cell in which rod-like liquid crystalline molecules are aligned substantially vertically when no voltage is applied, and substantially horizontally when a voltage is applied (Japanese Patent Laid-Open No. Hei 2-). 176625) (2) Liquid crystal cell (SID97, Digest of tech. Papers (Preliminary Proceed) 28 (1997) 845 in which the VA mode is converted into a multi-domain (MVA mode) for widening the viewing angle. ), (3) A liquid crystal cell in a mode (n-ASM mode) in which rod-like liquid crystalline molecules are substantially vertically aligned when no voltage is applied and twisted multi-domain alignment is applied when a voltage is applied (Preliminary collections 58-59 of the Japan Liquid Crystal Society) (1998)) and (4) SURVIVAL mode liquid crystal cells (announced at LCD International 98). Moreover, any of PVA (Patterned Vertical Alignment) type, optical alignment type (Optical Alignment), and PSA (Polymer-Stained Alignment) may be used. Details of these modes are described in JP-A-2006-215326 and JP-T-2008-538819.

  In an IPS mode liquid crystal cell, rod-like liquid crystal molecules are aligned substantially parallel to the substrate, and the liquid crystal molecules respond in a planar manner when an electric field parallel to the substrate surface is applied. The IPS mode displays black when no electric field is applied, and the absorption axes of the pair of upper and lower polarizing plates are orthogonal. JP-A-10-54982, JP-A-11-202323, and JP-A-9-292522 are methods for reducing leakage light at the time of black display in an oblique direction and improving a viewing angle using an optical compensation sheet. No. 11-133408, No. 11-305217, No. 10-307291, and the like.

  Here, in the IPS mode or VA mode liquid crystal cell, the transmission axis of the lower polarizer is usually arranged in the short side direction of the liquid crystal cell. When laminating the brightness enhancement film and the optical rotatory element by roll-to-roll, in order to produce the optical rotatory element on the brightness enhancement film by coating or the like, the rubbing direction needs to be the transport direction and 90 ° direction. Rubbing in the direction is difficult. Therefore, the effect of the present invention is particularly great in the case of a liquid crystal cell in which the side of the liquid crystal cell and the transmission axis of the polarizer are orthogonal or parallel like a liquid crystal cell of IPS mode or VA mode.

[Optical rotation film]
The optical rotatory film used in the present invention is an optical rotatory film including a support and an optical rotatory element.

{Dimension change rate S}
The dimensional change rate S after heat treatment at 80 ° C. for 24 hours of the optical rotatory film used in the present invention satisfies | S | ≦ 0.5. By setting the dimensional change rate S of the optical rotatory film in the above range, when the optical rotatory film and the brightness enhancement film are continuously bonded and produced, the curling of the optical rotatory film can be suppressed and the productivity can be improved.

  Here, as a method for adjusting the dimensional change rate S, for a support described later, a method of performing a pre-heat treatment, a method of using an amorphous polymer having a glass transition temperature of 100 ° C. or higher, and a crystal having a melting point of 150 ° C. or higher. And a method using a chiral polymer, and a method using a chiral agent when producing an optical rotatory element which will be described later.

From the viewpoint of curling more, | S | ≦ 0.4 is preferable, and | S | ≦ 0.3 is more preferable.
Here, the dimensional change rate S is a value measured by the following method.

<< Measurement method of dimensional change rate S >>
In the present invention, the dimensional change rate | S | before and after the lapse of 24 hours at 80 ° C. and 0% relative humidity is measured by the following method represented by the absolute value of L′−L0, and is a value expressed as a percentage.
A 100 mm × 30 mm sample was cut out with the film transport direction as the longitudinal direction. The initial length L0 is 100 mm.
Subsequently, the film length L ′ of the sample after 24 hours in an 80 ° C. relative humidity 0% environment was further measured for 2 hours in a 25 ° C. relative humidity 60% environment was measured.
S is represented by the following formula.
| S | = | L′−L0 | / L0 × 100

{Support}
The support used in the present invention is not particularly limited, and is not particularly limited as long as the dimensional change rate S described above can be satisfied when the optical rotation film is formed.

  As the support used in the present invention, various polymer films are preferred from the viewpoint of improving productivity by laminating an optical rotation film and a brightness enhancement film with roll-to-all. The polymer film is not particularly limited, but from the viewpoint of easily satisfying the dimensional change rate S, an amorphous polymer having a glass transition temperature of 100 ° C. or higher, or a crystalline polymer having a melting point of 150 ° C. or higher is used. It is preferable to use it.

  Specific examples of the amorphous polymer having a glass transition temperature of 100 ° C. or higher include cycloolefin polymers. A specific example of the crystalline polymer having a melting point of 150 ° C. or higher is a cellulose polymer.

<Optical properties of the support>
The retardation Re (550) at a wavelength of 550 nm of the support used in the present invention is 0 nm to 10 nm. The above range is preferable because the influence on the polarized light that has passed through the optical rotatory element can be reduced. The Re (550) of the support can be measured using the above-described retardation measuring method.

  Moreover, it is preferable that the retardation Rth (550) of the thickness direction in wavelength 550nm of the support body used for this invention is -50nm-50nm. By setting it as the said range, since the tint change when it sees from the diagonal direction can be made small, it is preferable. Rth (550) is preferably −30 nm to 30 nm, and more preferably −10 nm to 10 nm. The Rth (550) of the support can be measured using the above-described retardation measuring method.

<Film thickness of support>
The film thickness of the support used in the present invention is 10 μm to 100 μm. 10 micrometers-80 micrometers are preferable, and 10-40 micrometers is more preferable.

{Optical rotator}
The optical rotatory element used in the present invention is an optical element that rotates the polarization plane of polarized light emitted from a polarizer. The optical element for rotating the polarization plane of polarized light in the present invention creates a phase difference of π (λ / 2) with respect to the vibration of polarized light, as in a so-called general λ / 2 plate, resulting in a result. The optical element in which the vibration plane of polarized light is converted by 90 ° is not included.
In the present invention, having optical rotatory power means that linearly polarized light rotates and propagates in a medium while maintaining substantially linearly polarized light.

<Optical rotator thickness>
The film thickness of the optical rotatory element used in the present invention is preferably 1 μm to 5 μm.

<Optical characteristics of optical rotator>
The retardation Re (550) at a wavelength of 550 nm of the optical rotatory element used in the present invention is preferably 300 nm to 700 nm. By setting it as the said range, the color of a liquid crystal display device can be made uniform. Re (550) of the optical rotatory element can be measured using the above-described retardation measuring method. Re (550) is preferably 400 nm to 600 nm, and more preferably 420 nm to 480 nm.

  In addition, the optical rotatory element used in the present invention has a range of α ± 5 ° with respect to the angle α formed by the transmission axis of the lower polarizer and the transmission axis of the brightness enhancement film. It is preferable to rotate the light.

<Phase difference layer>
The optical rotatory element used in the present invention is preferably an optical rotatory element including a retardation layer.
Here, the retardation layer is preferably a retardation layer containing a liquid crystal compound or a chiral agent.

  In addition, when the optical rotatory element used in the present invention includes a retardation layer containing a liquid crystalline compound, the polarization rotation angle of the optical rotatory element and the rotational angle of the liquid crystalline compound are in the range of ± 10 °. preferable. It is more preferable that the values match within a range of ± 5 °, and it is even more preferable that the values match within a range of ± 3 °.

<Liquid crystal compound>
In general, liquid crystal compounds can be classified into a rod-shaped type and a disk-shaped type based on their shapes. In addition, there are low and high molecular types, respectively. Polymer generally refers to a polymer having a degree of polymerization of 100 or more (Polymer Physics / Phase Transition Dynamics, Masao Doi, 2 pages, Iwanami Shoten, 1992). In the present invention, any liquid crystal compound can be used, but a rod-like liquid crystal compound or a discotic liquid crystal compound (discotic liquid crystal compound) is preferably used. Two or more kinds of rod-like liquid crystalline compounds, two or more kinds of disc-like liquid crystalline compounds, or a mixture of a rod-like liquid crystalline compound and a disk-like liquid crystalline compound may be used. In order to fix the liquid crystalline compound, it is more preferable to use a rod-like liquid crystalline compound having a polymerizable group or a discotic liquid crystalline compound, and the liquid crystalline compound has 2 polymerizable groups in one molecule. It is more preferable to have the above. In the case where the liquid crystal compound is a mixture of two or more, it is preferable that at least one liquid crystal compound has two or more polymerizable groups in one molecule.

  As the rod-like liquid crystalline compound, for example, those described in claim 1 of JP-T-11-53019 and paragraphs [0026] to [0098] of JP-A-2005-289980 can be preferably used. As the tick liquid crystal compound, for example, those described in paragraphs [0020] to [0067] of JP-A-2007-108732 and paragraphs [0013] to [0108] of JP-A-2010-244038 are preferably used. However, it is not limited to these.

  The optical rotatory element used in the present invention may be an optical rotatory element formed by laminating a plurality of retardation layers, and includes a retardation layer containing a rod-like liquid crystalline compound and a retardation layer containing a discotic liquid crystalline compound. It is also preferable to make it an optical rotation element.

  When the optical rotatory element used in the present invention includes a retardation layer containing a rod-like liquid crystal compound, the liquid crystal display device can be made more homogeneous in color, so that the rod-like liquid crystal compound on the lower polarizer side of the optical rotator element can be used. The average major axis direction and the absorption axis of the lower polarizer are preferably parallel.

<Chiral agent>
The retardation layer used in the present invention may contain a chiral agent. The chiral agent is added to twist and align the liquid crystal compound. By producing the retardation layer of the present invention using a chiral agent, the influence of the coated substrate can be reduced as compared with the case where the coated substrate is arranged above and below, which is a normal method for producing an optical rotatory element, as described above. This is preferable because the dimensional change rate S can be reduced.

  The chiral agent is not particularly limited as long as it is compatible with the liquid crystal compound used in combination. Known chiral agents (for example, “Liquid Crystal Device Handbook” edited by Japan Society for the Promotion of Science 142nd Committee, Chapter 3-4-3, TN (twisted nematic), STN (Super Twisted Nematic), 199 pages, 1989 Can be used. The chiral agent generally contains an asymmetric carbon atom, but an axially asymmetric compound or a planar asymmetric compound containing no asymmetric carbon atom can also be used as the chiral agent. Examples of the axial asymmetric compound or the planar asymmetric compound include binaphthyl, helicene, paracyclophane, and derivatives thereof. Moreover, the chiral agent may have liquid crystallinity.

{Alignment film}
The optical rotatory film used in the present invention may have an alignment film in order to align the liquid crystalline compound when producing an optical rotatory element. The alignment film is disposed between the support and the optical rotator.

  Since the alignment film has a function of defining the alignment direction of the liquid crystalline compound, it is preferably used for realizing a preferred embodiment of the present invention. However, if the alignment state is fixed after the alignment of the liquid crystal compound, the alignment film plays the role and is not necessarily an essential component of the present invention.

The alignment film is an organic compound (eg, ω-tricosane) formed by rubbing treatment of an organic compound (preferably polymer), oblique deposition of an inorganic compound, formation of a layer having a microgroove, or Langmuir-Blodgett method (LB film). Acid, dioctadecylmethylammonium chloride, methyl stearylate). Furthermore, a method of forming an alignment film by applying an electric field, applying a magnetic field, or irradiating light (preferably polarized light) is also known.
The alignment film is preferably formed by rubbing a polymer film.

  Examples of the polymer used for forming the alignment film include, for example, methacrylate copolymers, styrene copolymers, polyolefins, polyvinyl alcohols and modified polymers described in paragraph [0022] of JP-A-8-338913. Examples include polyvinyl alcohol, poly (N-methylolacrylamide), polyester, polyimide, vinyl acetate copolymer, carboxymethyl cellulose, and polycarbonate.

  For example, the alignment film is formed by applying a solution containing the polymer as an alignment film forming material and an optional additive (for example, a cross-linking agent) on a support, and then drying (crosslinking) the coating film by heating. It can be formed by rubbing the film.

  For the rubbing treatment, a treatment method widely adopted as a liquid crystal alignment treatment process of LCD (liquid crystal display) can be applied. That is, a method of obtaining an alignment film by rubbing the surface of the coating film in a certain direction using paper, gauze, felt, rubber, nylon, polyester fiber or the like can be used. In general, the rubbing treatment is performed by rubbing about several times using a cloth in which fibers having a uniform length and thickness are flocked on average.

[Brightness enhancement film]
The brightness enhancement film used in the present invention is not particularly limited, and various known films can be used. Specific examples include a dielectric multilayer film described in Japanese Patent No. 04091978, 3M DBEF, 3M APF-v3, APF-v4, and the like.

  In the liquid crystal display device of the present invention, the angle α formed by the transmission axis of the lower polarizer and the transmission axis of the brightness enhancement film is 30 ° to 150 °. By setting it as this range, it becomes possible to produce while conveying a lower polarizer and a brightness improvement film by roll to roll, and productivity can be improved.

[Adhesive or adhesive]
In the liquid crystal display device of the present invention, the optical rotatory element in the optical rotatory film and the brightness enhancement film are arranged via an adhesive or an adhesive. Various known adhesives or pressure-sensitive adhesives can be used.

  The haze of the pressure-sensitive adhesive is preferably 10% to 85%, more preferably 25% to 70%, from the viewpoint of improving the color tone.

<Method of measuring haze>
In the present invention, haze is a value measured under the following conditions based on JIS K-7136 (2000).
[Device Name] Haze Meter NDH2000 (Nippon Denshoku Industries Co., Ltd.)
[Sample size] 50 mm x 50 mm
[Measurement environment] 55 ° C, relative humidity 55%

  Hereinafter, the present invention will be described in more detail based on examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the following examples.

<Production of support>
Supports SA to SL were prepared by the following method. Table 2 shows the physical properties of the prepared support.

[Production of Support SA]
The following support SA dope composition was filtered through a filter paper having an average pore diameter of 34 μm and a sintered metal filter having an average pore diameter of 10 μm, and then cast on a metal support at 20 ° C. (band casting machine). The film was peeled off at a solvent content of about 20% by mass, both ends in the width direction of the film were fixed with tenter clips, and dried while being stretched in the transverse direction at a stretch ratio of 1.1. Then, it dried further by conveying between the rolls of the heat processing apparatus, and produced support SA with a thickness of 20 μm.

─────────────────────────────────
Support SA Dope Composition ─────────────────────────────────
Cellulose acetate with an acetyl substitution degree of 2.88 100 parts by mass Polyester A 12 parts by mass The following A-3 compound 2 parts by mass Citric acid fatty acid monoglyceride (Poem K-37V, manufactured by Riken Vitamin) 2 parts by mass Methylene chloride 430 parts by mass Methanol 64 parts by mass ──────────────────────────────────

  Polyester A has a structure in which number average molecular weight Mn = 750, 1,2-cyclohexyldicarboxylic acid and ethylene glycol are polymerized 1: 1, and the ends are sealed with acetyl groups.

[Preparation of Support SB]
In the production of the support SA, a support SB having a thickness of 20 μm was produced in the same manner except that the dope composition was changed to the following support SB dope composition.
─────────────────────────────────
Support SB dope composition ─────────────────────────────────
Cellulose acetate having an acetyl substitution degree of 2.88 100 parts by mass The following polyester B 13 parts by mass Citric acid fatty acid monoglyceride (Poem K-37V, manufactured by Riken Vitamin Co., Ltd.) 2 parts by mass Methylene chloride 430 parts by mass Methanol 64 parts by mass ──────────────────────────────

[Preparation of Support SC]
In the production of the support SA, except that the solvent content at the time of peeling was about 40% by mass, the draw ratio was 1.3 times, and the casting amount was changed so that the film thickness after drying was 20 μm. Similarly, a support SC having a thickness of 20 μm was produced.

[Preparation of Support SD]
In the production of the support SA, except that the solvent content at the time of peeling was about 60% by mass, the draw ratio was 1.5 times, and the casting amount was changed so that the film thickness after drying was 20 μm. Similarly, a support SD having a thickness of 20 μm was produced.

[Preparation of support SE]
In the production of the support SA, the casting content was changed so that the solvent content at the time of peeling was about 15% by mass, the draw ratio was 1.05 times, and the film thickness after drying was 7 μm. Similarly, a support SE having a thickness of 7 μm was produced.

[Preparation of Support SF]
In the production of the support SA, the casting content was changed so that the solvent content at the time of peeling was about 20% by mass, the draw ratio was 1.05 times, and the film thickness after drying was 12 μm. Similarly, a support SF having a thickness of 12 μm was produced.

[Preparation of Support SG]
“TD40UL” manufactured by Fuji Film was used as the support SG.

[Preparation of Support SH]
The following support SH dope composition was filtered through a filter paper having an average pore diameter of 34 μm and a sintered metal filter having an average pore diameter of 10 μm, and then cast on a metal support at 20 ° C. (band casting machine). It peeled off in the state of solvent content rate of about 60 mass%, the both ends of the width direction of the film were fixed with the tenter clip, and it dried, extending | stretching by the draw ratio 1.1 times in the horizontal direction. Then, it dried further by conveying between the rolls of heat processing apparatus, and produced support body SH with a thickness of 80 micrometers.

─────────────────────────────────
Support SH Dope Composition ─────────────────────────────────
Cellulose acetate having an acetyl substitution degree of 2.88 100 parts by mass The above polyester B 17 parts by mass The above A-3 compound 2 parts by mass Citric acid fatty acid monoglyceride (Poem K-37V, manufactured by Riken Vitamin) 2 parts by mass methylene chloride (first solvent) 430 parts by mass Methanol (second solvent) 64 parts by mass ────────────────────────────────

[Preparation of Support SI]
In the production of the support SH, a support SI was produced in the same manner except that the amount of polyester B added was 19 parts by mass and the film thickness was 90 μm.

[Preparation of Support SJ]
In the production of the support SH, a support SJ was produced in the same manner except that the amount of polyester B added was 26 parts by mass and the film thickness was 120 μm.

[Preparation of Support SK]
Under an ethylene atmosphere, toluene and a phenylnorbornene-toluene solution were placed in an autoclave having a volume of 1.6 l so that the norbornene concentration was 20 mol / l and the total liquid volume was 640 ml. Methylaluminoxane (manufactured by Albemarle, MAO 20% toluene solution) was added with 5.88 mmol and methylene (cyclopentadienyl) (tetramethylcyclopentadienyl) zirconium dichloride 1.5 μmol based on Al, ethylene was introduced and pressure was added. Was kept at 0.2 MPa for 60 minutes at 80 ° C.

  After completion of the reaction, ethylene was depressurized while allowing to cool, and the system was replaced with nitrogen. Thereafter, 3.0 g of silica (made by Fuji Silysia Co., grade: G-3 particle size: 50 μm) whose adsorbed water content was adjusted to 10% by mass was added and reacted for 1 hour. The reaction solution was placed in a pressure filter (Advantech Toyo Co., Ltd., model KST-90-UH) set with filter paper (5C, 90 mm) and Celite (Wako Pure Chemical Industries, Ltd.), and pressure filtered with nitrogen for polymerization. The liquid was collected. The polymerization solution was added dropwise in 5 times amount of acetone to cause precipitation to obtain cycloolefin polymer SK. The weight average molecular weight of the cycloolefin polymer SK was 142,000, and the glass transition temperature was 140 ° C.

  T-type film having a resin melt kneader equipped with a 65 mmφ screw after drying the cycloolefin polymer SK synthesized above using a hot air dryer in which air is circulated for 2 hours at 70 ° C. to remove moisture. Using a melt extrusion molding machine (T die width 500 mm), extrusion molding was performed under molding conditions of a molten resin temperature of 240 ° C. and a T die temperature of 240 ° C. to prepare a support SK having a thickness of 20 μm.

[Preparation of Support SL]
In a 2 L four-necked flask equipped with a thermometer, condenser, stirrer, and Dean Stark, 307 parts by mass of methyl pyruvate, 171 parts by mass of 2-pyrrolidone, 1040 parts by mass of toluene, and 0.3 parts by mass of methoquinone as a polymerization inhibitor 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (4H-TEMPO) 0.6 parts by mass, p-toluenesulfonic acid monohydrate 3.8 parts by mass as a catalyst was added and stirred. The mixture was heated until the internal temperature reached 114 ° C. and reacted for 20 hours while distilling off water under reflux. After the reaction, toluene was distilled off with an evaporator, followed by distillation purification to obtain 203 parts by mass of methyl 2- (2-oxopyrrolidin-1-yl) acrylate (precursor SL).

  In a reaction vessel that can be sealed, 3 parts by mass of precursor SL and 87 parts by mass of methyl methacrylate (MMA) are added, and t-amylperoxy-2-ethylhexanoate (manufactured by Arkema Yoshitomi “ "Lupelox (registered trademark) 575") 0.1 parts by mass was added, and the mixture was immersed in an oil bath at 90 ° C and subjected to standing polymerization for 8 hours. The obtained polymer was reprecipitated with isopropanol and dried under reduced pressure to obtain a white polymer (material SL).

  Next, the material SL synthesized above was dried at 70 ° C. for 2 hours using a hot air dryer in which air was circulated to remove moisture, and then a T-die type having a resin melt kneader equipped with a 65 mmφ screw Using a film melt extrusion molding machine (T die width 500 mm), extrusion molding was performed under molding conditions of a molten resin temperature of 220 ° C. and a T die temperature of 220 ° C. to prepare a support SK having a thickness of 20 μm.

<Saponification treatment of support>
After passing the produced support bodies SA to SL through a dielectric heating roll having a temperature of 60 ° C. and raising the film surface temperature to 40 ° C., an alkali solution having the composition shown below is applied to one side of the film using a bar coater. It was applied at a coating amount of 14 ml / m 2 and heated to 110 ° C. It was transported for 10 seconds under a steam far infrared heater manufactured by Noritake Company Limited. Subsequently, 3 ml / m 2 of pure water was applied using the same bar coater. Next, washing with a fountain coater and draining with an air knife were repeated three times, and then transported to a drying zone at 70 ° C. for 10 seconds and dried to prepare an alkali saponified support.

─────────────────────────────────
Alkaline solution composition ─────────────────────────────────
Potassium hydroxide 4.7 parts by weight Water 15.8 parts by weight Isopropanol 63.7 parts by weight Surfactant: C ₁₄ H ₂₉ O (CH ₂ CH ₂ O) ₂₀ H 1.0 part by weight Propylene glycol 14.8 parts by weight ─────────────────────────────────

<Formation of alignment film>
An alignment film coating solution having the following composition was continuously applied to the prepared alkali-saponified supports SA to SL with a # 14 wire bar. Drying was performed with warm air of 60 ° C. for 60 seconds, and further with warm air of 100 ° C. for 120 seconds. The obtained coating film was continuously rubbed. At this time, the longitudinal direction and the conveying direction of the long film were parallel, and the rubbing angle was set to the rubbing angle shown in Table 2.

─────────────────────────────────
Composition of alignment film coating solution ─────────────────────────────────
Denatured polyvinyl alcohol 10 parts by weight Water 371 parts by weight Methanol 119 parts by weight Glutaraldehyde 0.5 parts by weight Photopolymerization initiator (Irgacure 2959, manufactured by BASF) 0.3 parts by weight ────────── ───────────────────────

<Production of optical rotation film>
An optical rotatory element was formed by the following method so as to obtain the combinations shown in Table 2 with respect to the prepared support members SA to SL with the alignment film, thereby preparing an optical rotatory film. In the table, RLC represents that an optical rotatory element was formed using the following rod-shaped liquid crystalline compound, DLC represents that an optical rotatory element was formed using the following discotic liquid crystalline compound, and lamination was the following rod-shaped liquid crystal It shows that an optical rotatory element was formed by laminating an active compound and a discotic liquid crystalline compound to produce an optical rotatory film.

  In Comparative Example 2, no optical rotatory element was formed. In Comparative Example 3, the following λ / 2 plate was formed instead of the optical rotatory element.

[Optical rotator formation using rod-like liquid crystalline compounds]
A coating solution having the following composition was applied to the surface of the prepared alignment film using a bar coater so as to have the thickness shown in Table 2. After drying at an ambient temperature of 95 ° C. for 90 seconds, cooling to room temperature, irradiating with ultraviolet rays (300 mJ / cm ² ) at 25 ° C., fixing the orientation of the liquid crystal compound, and forming an optical rotatory element using a rod-like liquid crystal compound did.

─────────────────────────────────
Rod-like liquid crystal compound coating solution ─────────────────────────────────
Methyl ethyl ketone 233 parts by mass Cyclohexanone 12 parts by mass The following rod-like liquid crystalline compound 201 83 parts by mass The following rod-like liquid crystalline compound 202 15 parts by mass The following rod-like liquid crystal compound 203 2 parts by mass Polyfunctional monomer A-TMMT (manufactured by Shin-Nakamura Chemical Co., Ltd.) ) 1 part by weight polymerization initiator IRGACURE 819 (manufactured by BASF) 4 parts by weight The following surfactant 1 0.05 part by weight The following surfactant 2 0.01 part by weight chiral agent In the table ──────── ────────────────────────

[Optical rotator formation using discotic liquid crystalline compounds]
A coating solution having the following composition was applied to the surface of the prepared alignment film using a bar coater so as to have the thickness shown in Table 2. An optical rotatory element using a discotic liquid crystalline compound after drying at an atmospheric temperature of 115 ° C. for 90 seconds, cooling to 90 ° C., and irradiating with ultraviolet rays (300 mJ / cm ² ) at 25 ° C. to fix the orientation of the liquid crystal compound. Formed.

─────────────────────────────────
Disc-like liquid crystal compound coating solution ──────────────────────────────────
Methyl ethyl ketone 241 parts by mass Cyclohexanone 13 parts by mass Discotic liquid crystalline compound 101 80 parts by mass Discotic liquid crystalline compound 102 20 parts by mass Polymerization initiator 1 3 parts by mass Polymerizable monomer 1 5 parts by mass Orientation aid 1 0.35 parts by mass Interface Activator 3 0.2 parts by mass The above chiral agent Listed in the table ─────────────────────────────────

[Formation of optical rotatory device by laminating rod-like liquid crystalline compound and discotic liquid crystalline compound]
A retardation layer was formed on the surface of the prepared alignment film in the same manner as the optical rotatory element formation using the rod-like liquid crystalline compound described above. On the formed retardation layer, the alignment film 2 was formed by the same procedure as the formation of the alignment film described above. A retardation layer was formed on the surface of the formed alignment film 2 by the same procedure as the optical rotator formation using the discotic liquid crystalline compound described above to form an optical rotatory element.

[Formation of λ / 2 plate]
A coating solution having the following composition was applied to the surface of the prepared alignment film using a bar coater so that the thickness after drying was 1.6 μm. After drying for 90 seconds at an ambient temperature of 95 ° C., cooling to room temperature, irradiating with ultraviolet rays (300 mJ / cm ² ) at 25 ° C., fixing the orientation of the liquid crystal compound, and a λ / 2 plate using a rod-like liquid crystal compound Formed.

─────────────────────────────────
λ / 2 plate coating solution ──────────────────────────────────
Methyl ethyl ketone 233 parts by mass Cyclohexanone 12 parts by mass Rod-like liquid crystalline compound 201 83 parts by mass Rod-like liquid crystalline compound 202 15 parts by mass Rod-like liquid crystal compound 203 2 parts by mass Polyfunctional monomer A-TMMT (manufactured by Shin-Nakamura Chemical Co., Ltd.) 1 part by mass Part polymerization initiator IRGACURE 819 (manufactured by BASF) 4 parts by weight surfactant 1 0.05 parts by weight surfactant 2 0.01 parts by weight ─────────────────── ──────────────

  The dimensional change rate | S |, Re (550), and the polarization rotation angle of the optical rotatory element were measured by the above-described methods for each optical rotation film produced. The results are shown in Table 2.

<Creating a polarizer>
A PVA film having a thickness of 45 μm is dyed by immersion in an iodine aqueous solution having an iodine concentration of 0.05% by mass at 30 ° C. for 60 seconds, and then immersed in an aqueous boric acid solution having a boric acid concentration of 4% by mass for 60 seconds. The film was longitudinally stretched 5 times the original length, and then dried at 50 ° C. for 4 minutes to obtain a polarizer having a thickness of 15 μm. At this time, the stretching direction and the absorption axis direction were parallel.

<Production of adhesive>
Nitrogen gas was introduced into a reactor equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen inlet tube, and the air in the reactor was replaced with nitrogen gas. Thereafter, 85 parts by mass of butyl acrylate, 8 parts by mass of benzyl acrylate, 5 parts by mass of benzyl methacrylate, 1 part by mass of 6-hydroxyhexyl acrylate, 8 parts by mass of diethyl acrylamide and 65 parts by mass of a solvent (ethyl acetate) were added to the reaction apparatus. Thereafter, 0.1 part by mass of azobisisobutyronitrile was added as a polymerization initiator and reacted at 65 ° C. for 6 hours to obtain an acrylic copolymer solution.

  Table 1 shows 0.2 parts by mass of coronate HX (an isocyanurate of a hexamethylene diisocyanate compound) and silica melamine core-shell particles (particle diameter: 2 μm, refractive index: 1.65) with respect to the acrylic copolymer solution prepared above. The PSA composition of Examples 10 to 13 was obtained by adding and stirring and mixing. After applying this adhesive composition on a release film made of a polyethylene terephthalate (PET) film coated with a silicone resin, the solvent was removed by drying at 90 ° C., and then in an atmosphere of 23 ° C. and 50% RH. By aging for 7 days, a pressure-sensitive adhesive having a haze property (thickness 20 μm) formed by crosslinking the pressure-sensitive adhesive composition was produced.

  At this time, the haze of each pressure-sensitive adhesive was measured according to the method described above. The results are shown in Table 1.

<Preparation of upper polarizing plate (for IPS)>
The above-described saponification treatment was performed on LR05 manufactured by Fujifilm and ZRD40 manufactured by Fujifilm. Using a commercially available polyvinyl alcohol-based adhesive, LR05 and ZRD40 were bonded to both sides of the prepared polarizer to prepare an upper polarizing plate.

<Preparation of upper polarizing plate (for TN)>
The above-described saponification treatment was performed on Fujifilm LR05 and Fujifilm WV film. Using a commercially available polyvinyl alcohol-based adhesive, LR05 and a WV film were bonded to both surfaces of the prepared polarizer to prepare an upper polarizing plate.

<Preparation of Upper Polarizing Plate (for Example 22)>
[Preparation of polyester film 1]
The raw polyester 1 (Sb catalyst PET) is obtained by a continuous polymerization apparatus using a direct esterification method in which terephthalic acid and ethylene glycol are directly reacted to distill off water and esterify, followed by polycondensation under reduced pressure. Obtained.

(1) Esterification reaction In a first esterification reactor, 4.7 tons of high-purity terephthalic acid and 1.8 tons of ethylene glycol are mixed over 90 minutes to form a slurry, and continuously at a flow rate of 3800 kg / h. It supplied to the 1st esterification reaction tank. Further, an ethylene glycol solution of antimony trioxide was continuously supplied, and the reaction was carried out at a reaction vessel temperature of 250 ° C. with stirring and an average residence time of about 4.3 hours. At this time, antimony trioxide was continuously added so that the amount of Sb added was 150 ppm in terms of element.

  This reaction product was transferred to a second esterification reaction vessel, and reacted with stirring at a temperature in the reaction vessel of 250 ° C. and an average residence time of 1.2 hours. To the second esterification reaction tank, an ethylene glycol solution of magnesium acetate and an ethylene glycol solution of trimethyl phosphate are continuously supplied so that the added amount of Mg and the added amount of P are 65 ppm and 35 ppm in terms of element, respectively. did.

(2) Polycondensation reaction The esterification reaction product obtained above was continuously supplied to the first polycondensation reaction tank, and with stirring, the reaction temperature was 270 ° C. and the reaction tank internal pressure was 20 torr (2.67 × 10 −2). 3 MPa) at a mean residence time of about 1.8 hours.

  Further, it was transferred to the second double condensation reaction tank, and under this stirring condition, the reaction tank temperature was 276 ° C., the reaction tank pressure was 5 torr (6.67 × 10 −4 MPa), and the residence time was about 1.2 hours. (Polycondensation).

  Subsequently, it was further transferred to the third triple condensation reaction tank. In this reaction tank, the temperature in the reaction tank was 278 ° C., the pressure in the reaction tank was 1.5 torr (2.0 × 10 −4 MPa), and the residence time was 1.5 hours. Reaction (polycondensation) was carried out under conditions to obtain a reaction product (polyethylene terephthalate (PET)).

  Next, the obtained reaction product was discharged into cold water in a strand form and immediately cut to prepare polyester pellets (cross section: major axis: about 4 mm, minor axis: about 2 mm, length: about 3 mm).

  The obtained polymer had IV = 0.63. This polymer was designated as raw material polyester 1 (hereinafter abbreviated as PET1).

{Film forming process}
After 90 parts by mass of raw material polyester 1 (PET1) and 10 parts by mass of raw material polyester 2 (PET2) containing an ultraviolet absorber are dried to a water content of 20 ppm or less, the hopper 1 of a uniaxial kneading extruder 1 having a diameter of 50 mm is used. The melt was added to the extruder 1 at 300 ° C. (intermediate layer II layer).
Moreover, after drying PET1 to a water content of 20 ppm or less, it was put into a hopper 2 of a uniaxial kneading extruder 2 with a diameter of 30 mm and melted at 300 ° C. with the extruder 2 (outer layer I layer, outer layer III layer).
These two kinds of polymer melts are passed through one set of filtration devices each having a gear pump and a filter (opening 8 μm, that is, a pore diameter of 8 μm), and then from the extruder 1 in a two-type three-layer merge block. The extruded polymer was laminated on the intermediate layer (II layer) so that the polymer extruded from the extruder 2 became the outer layer (I layer and III layer), and extruded from a 120 mm wide die into a sheet.
The molten resin was extruded from the die under the conditions that the pressure fluctuation was 1% and the temperature distribution of the molten resin was 2%. Specifically, the back pressure was increased by 1% with respect to the average pressure in the barrel of the extruder, and the piping temperature of the extruder was heated at a temperature 2% higher than the average temperature in the barrel of the extruder.
The molten resin extruded from the die was extruded onto a cooling cast drum set at a temperature of 25 ° C., and was brought into close contact with the cooling cast drum using an electrostatic application method. The resin temperature during extrusion was 300 ° C. The resin temperature when closely contacting the cooling drum was 277 ° C. It peeled using the peeling roll arrange | positioned facing the cooling cast drum, and the unstretched polyester film 1 was obtained. At this time, the discharge amount of each extruder was adjusted so that the ratio of the thicknesses of the I layer, the II layer, and the III layer was 10:80:10.

{Formation of easy adhesion layer}
(1) Formation of hard coat layer side easy-adhesion layer The following compounds were mixed in the following ratio to prepare a coating liquid H1 for the hard coat layer-side easy adhesive layer.

・ Coating liquid H1 for hard coat layer side easy adhesion layer
60 parts by weight of the following polyester resin 3 25 parts by weight of the following acrylic resin 1 10 parts by weight of the following melamine compound 1 5 parts by weight of the following particles 1

Details of the compounds used are shown below.
-Polyester resin 3:
Polyester resin sulfonic acid aqueous dispersion monomer composition copolymerized with monomers of the following composition: (acid component) terephthalic acid / isophthalic acid / 5-sodium sulfoisophthalic acid // (diol component) ethylene glycol / 1,4- Butanediol / diethylene glycol = 56/40/4 // 70/20/10 (mol%)

・ Acrylic resin 1:
Aqueous dispersion of acrylic resin polymerized with monomers of the following composition Ethyl acrylate / n-butyl acrylate / methyl methacrylate / N-methylol acrylamide / acrylic acid = 65/21/10/2/2 (mass%) emulsion polymer ( Emulsifier: Anionic surfactant)
Melamine compound 1: Hexamethoxymethyl melamine Particle 1: Silica sol with an average particle size of 65 nm

(2) Formation of polarizer-side easy-adhesion layer The following compounds were mixed in the following ratio to prepare a coating liquid P1 for a polarizer-side easy-adhesion layer.

(2-1) Synthesis of copolymer polyester resin (A-1) Dimethyl terephthalate 194.2 parts by mass Dimethyl isophthalate 184.5 parts by mass Dimethyl-5-sodium sulfoisophthalate 14.8 parts by mass Diethylene glycol 233.5 parts by mass Ethylene glycol 136.6 parts by mass Tetra-n-butyl titanate 0.2 parts by mass The above compound was charged, and a transesterification reaction was performed at a temperature of 160 ° C to 220 ° C over 4 hours. Next, the temperature was raised to 255 ° C., and the pressure of the reaction system was gradually reduced, followed by reaction for 1 hour 30 minutes under a reduced pressure of 30 Pa to obtain a copolymerized polyester resin (A-1).

(2-2) Preparation of polyester aqueous dispersion (Aw-1) Copolyester resin (A-1) 30 parts by mass Ethylene glycol n-butyl ether 15 parts by mass Dissolved. After the resin was completely dissolved, 55 parts by mass of water was gradually added to the polyester solution while stirring. After the addition, the solution was cooled to room temperature while stirring to prepare a milky white polyester aqueous dispersion (Aw-1) having a solid content of 30% by mass.

(2-3) Preparation of aqueous polyvinyl alcohol solution (Bw-1) 90 parts by mass of water was added, and while stirring, polyvinyl alcohol resin (manufactured by Kuraray) having a saponification degree of 88% and a polymerization degree of 500 (B-1) 10 masses Part was added gradually. After the addition, the solution was heated to 95 ° C. while stirring to dissolve the resin. After dissolution, the mixture was cooled to room temperature with stirring to prepare a polyvinyl alcohol aqueous solution (Bw-1) having a solid content of 10% by mass.

Polyisocyanate compound having isocyanurate structure made from hexamethylene diisocyanate (Duranate TPA manufactured by Asahi Kasei Chemicals)
100 parts by mass Propylene glycol monomethyl ether acetate 55 parts by mass Polyethylene glycol monomethyl ether (average molecular weight 750) 30 parts by mass The above compound was charged and held at 70 ° C. for 4 hours in a nitrogen atmosphere. Thereafter, the reaction solution temperature was lowered to 50 ° C., and 47 parts by mass of methyl ethyl ketoxime was added dropwise. The infrared spectrum of the reaction solution was measured to confirm that the absorption of the isocyanate group had disappeared, and a block polyisocyanate aqueous dispersion (C-1) having a solid content of 75% by mass was obtained.

The following coating agent was mixed and the coating liquid P1 for polarizer side easily bonding layers from which the mass ratio of polyester-type resin (A-1) / polyvinyl alcohol-type resin (B-1) becomes 70/30 was produced.
Water 40.61 mass%
Isopropanol 30.00% by mass
Polyester water dispersion (Aw-1) 11.67 mass%
Polyvinyl alcohol aqueous solution (Bw-1) 15.00 mass%
Block isocyanate-based crosslinking agent (C-1) 0.67% by mass
Particles (silica sol with an average particle diameter of 100 nm, solid content concentration 40% by mass)
1.25% by mass
Catalyst (organotin-based compound solid concentration 14% by mass) 0.3% by mass
Surfactant (silicon-based, solid content concentration 10% by mass) 0.5% by mass

(3) Application of easy-adhesion layer to both surfaces of polyester film In the bar coating method using a wire bar, the following coating liquid H1 for the hard coat layer-side easy-adhesion layer is applied to one side of the unstretched polyester film 1 The coating liquid P1 for the polarizer-side easy-adhesion layer was applied to the surface using a wire bar while adjusting the coating amount after drying so that both surfaces were 0.12 g / m2.

(Horizontal stretching process)
-Preheating section-
The preheating temperature was 90 ° C., and the mixture was heated to a temperature at which stretching was possible.

-Extension part-
The unstretched polyester film 1 coated and preheated with an easy-adhesion layer is guided to a tenter (transverse stretching machine), and the ends of the film are gripped with clips, while the TD direction (film width direction, The film was transversely stretched under the following conditions in the transverse direction) to obtain a film having a width of 5 m.
"conditions"
-Transverse stretching temperature: 90 ° C
・ Horizontal stretch ratio: 4.3 times

-Heat fixing part-
Next, a heat setting treatment was performed while controlling the film surface temperature of the polyester film within the following range.
<Condition>
・ Heat setting temperature: 180 ℃
・ Heat setting time: 15 seconds

-Thermal relaxation part-
The polyester film after heat setting was heated to the following temperature to relax the film.
-Thermal relaxation temperature: 170 ° C
-Thermal relaxation rate: TD direction (film width direction, lateral direction) 2%

-Cooling section-
Next, the polyester film after heat relaxation was cooled at a cooling temperature of 50 ° C.

-Film collection and film division-
After cooling, the polyester film 1 was divided into 1.4 m widths in the width direction, and the chuck portion was trimmed. Then, after extruding (knurling) at a width of 10 mm on both ends of each divided roll, it was wound up 2000 m at a tension of 18 kg / m. As described above, three rolls of a uniaxially stretched polyester film 1 having a strip shape (long shape) having a thickness of 100 μm and a width of 1.4 m were produced.

(Formation by applying a hard coat layer)
Thereafter, the surface of the polyester film 1 coated with the coating liquid H1 for the hard-coat layer-side easy-adhesion layer was coated and dried with a mixed coating liquid (acrylic-1) having the following composition so that the dry film thickness was 5 μm. A hard coat layer was formed by irradiating with ultraviolet rays to obtain a polyester film 1 having a single-side hard coat layer and a single-side easy-adhesion layer.
Dipentaerythritol hexaacrylate 85 parts by mass 2-hydroxy-3-phenoxypropyl acrylate 15 parts by mass photopolymerization initiator (trade name: Irgacure 184, manufactured by Ciba Specialty Chemicals)
5 parts by weight methyl ethyl ketone 200 parts by weight

  The above-described saponification treatment was performed on the produced single-sided hard coat, the polyester film 1 with a single-sided easy-adhesion layer, and ZRD40 manufactured by Fuji Film. Using a commercially available polyvinyl alcohol-based adhesive, the polyester film 1 and ZRD 40 were bonded to both surfaces of the above-prepared polarizer to prepare an upper polarizing plate for Example 22.

<Preparation of Upper Polarizing Plate (for Example 23)>
A lower polarizing plate for Example 23 was produced in the same manner as in the production of the above upper polarizing plate (for IPS) except that the produced support SK was used instead of ZRD40.

<Preparation of Upper Polarizing Plate (for Example 24)>
A lower polarizing plate for Example 24 was produced in the same manner as in the production of the lower polarizing plate (for IPS) except that the produced support SL was used instead of ZRD40.

<Preparation of lower polarizing plate (for IPS)>
The above-described saponification treatment was performed on Fujifilm ZRD40. When the support of the optical rotatory film to be bonded is a cellulose-based support, a commercially available polyvinyl alcohol-based adhesive is used. In other cases, an epoxy-based adhesive is used. The optical rotation films prepared above were bonded together. At this time, they were bonded together so that the support side of the optical rotation film was on the polarizer side.

Thereafter, using the adhesive in the table, the optical rotatory element side of the optical rotatory film and APF-V4 manufactured by 3M were bonded together by roll-to-roll to produce a lower polarizing plate. At this time, bonding was performed so that the angle α formed by the transmission axis of the polarizer and the transmission axis of APF-V4 was a value in the table.
In the table, those having an adhesive haze of 0% indicate that a commercially available adhesive SK2057 (manufactured by Soken Chemical) was used.

<Preparation of Lower Polarizing Plate (for Example 23)>
A lower polarizing plate for Example 23 was manufactured in the same manner as in the preparation of the lower polarizing plate described above (for IPS) except that the prepared support SK was used instead of ZRD40.

<Preparation of Lower Polarizing Plate (for Example 24)>
A lower polarizing plate for Example 24 was produced in the same manner as in the production of the lower polarizing plate (for IPS) except that the produced support SL was used instead of ZRD40.

<Preparation of lower polarizing plate (for TN)>
The saponification process mentioned above was performed with respect to the Fujifilm WV film. Using a commercially available polyvinyl alcohol-based adhesive, the WV film and each of the produced optical rotation films were bonded to both surfaces of the produced polarizer by roll-to-roll. At this time, they were bonded together so that the support side of the optical rotation film was on the polarizer side.

  Thereafter, using a commercially available adhesive SK2057 (manufactured by Soken Chemical Co., Ltd.), the optical rotatory element side of the optical rotatory film and APF-V4 manufactured by 3M were bonded together to produce a lower polarizing plate. At this time, bonding was performed so that the angle α formed by the transmission axis of the polarizer and the transmission axis of APF-V4 was a value in the table.

  About the lower side polarizing plate of the comparative example 1, the lower side polarizing plate was produced, without bonding APF-V4.

  The lower polarizing plate of Comparative Example 5 was bonded so that the ZRD 40 and the optical rotatory film were reversed, that is, the optical rotatory film on the side to be bonded to the liquid crystal cell and the ZRD 40 on the side to be bonded to the APF-V4. It was.

  For the lower polarizing plates of Comparative Examples 6 and 7, the same procedure as the formation of the alignment film and the formation of the optical rotation element using the rod-like liquid crystalline compound was performed on the prepared polarizer instead of each optical rotation film. An optical rotatory element was formed to produce a lower polarizing plate.

  In addition, since the polarizing plate was broken during the production of the lower polarizing plate of Comparative Example 6 and the liquid crystal display device could not be produced, Comparative Example 7 was a roll-to-roll process using an optical rotator and an APF-V4. A polarizing plate was produced by batch bonding without cutting and bonding after cutting.

<Measurement of polarizing plate curl>
A glass having a thickness of 100 μm, a length of 100 mm and a width of 50 mm was prepared, and the produced lower polarizing plate was cut into the same size as the glass, and a commercially available adhesive SK2057 ( Bonding was performed using a product manufactured by Soken Chemical.

Then, after maintaining for 3 days in an environment of 50 ° C. and 85% relative humidity, it was transferred to an environment of 25 ° C. and 60% relative humidity, and after 24 hours, the height of the warp of the glass was measured and evaluated according to the following criteria. The results are shown in Table 2.
A: 0 or more and less than 2 mm B: 2 mm or more and less than 5 mm C: 5 mm or more

<Evaluation of punching aptitude>
The produced lower polarizing plate was cut to a size of 100 × 100 mm with a Thomson blade, the punched end face was observed using a microscope, and the depth of the crack was evaluated according to the following criteria. The results are shown in Table 2.
A: No crack was observed.
B: A slight crack having a depth of less than 0.2 mm was confirmed.
C: A crack having a depth of 0.2 mm or more was confirmed.

<Appropriate polarizing plate processing>
In preparation of the said lower side polarizing plate, the processing reference at the time of bonding an optical rotation film and APF-V4 with a roll toe roll was evaluated on the following reference | standard. The results are shown in Table 2.
A: Bonded without any particular problem.
B: Bonding was possible, but the polarizing plate was curled.
C: It broke and could not be bonded.

<Production of liquid crystal display device>
A liquid crystal display device was produced by combining the liquid crystal display device, the upper polarizing plate and the lower polarizing plate so as to have the combinations shown in Table 2. Here, when the cell mode was IPS, each liquid crystal display device was produced according to the production of the following IPS liquid crystal display device, and when the cell mode was TN, according to the production of the following TN liquid crystal display device.

[Production of IPS liquid crystal display device]
The viewing-side polarizing plate and the backlight-side polarizing plate of a commercially available liquid crystal display device (manufactured by LGE, 32LF5800) are peeled off, and the above-prepared upper polarizing plate and lower polarizing plate are bonded using a commercially available adhesive, and the liquid crystal display device Was made. At this time, the transmission axis of the lower polarizing plate and the long side of the liquid crystal cell are set so that the crossing angle of the transmission axis of the upper polarizing plate and the transmission axis of the lower polarizing plate becomes the value of the upper and lower polarizing plate angles in Table 2. Bonding was performed so that the crossing angle was the angle of the lower polarizing plate in Table 2. The upper polarizing plate was arranged so that ZRD 40 was on the liquid crystal cell side, and the lower polarizing plate was arranged so that ZRD 40 was on the liquid crystal cell side and APF-V4 was on the backlight side.

[Production of TN liquid crystal display device]
The viewing side polarizing plate and the backlight side polarizing plate of a commercially available liquid crystal display device (LGE 22M37D-B) are peeled off, and the above-prepared upper polarizing plate and lower polarizing plate are bonded together using a commercially available adhesive. A liquid crystal display device was produced. At this time, the transmission axis of the lower polarizing plate and the long side of the liquid crystal cell are set so that the crossing angle of the transmission axis of the upper polarizing plate and the transmission axis of the lower polarizing plate becomes the value of the upper and lower polarizing plate angles in Table 2. Bonding was performed so that the crossing angle was the angle of the lower polarizing plate in Table 2. The upper polarizing plate was arranged so that the WV film was on the liquid crystal cell side, and the lower polarizing plate was arranged so that the WV film was on the liquid crystal cell side and APF-V4 was on the backlight side.

<< Evaluation of transmission axis matching >>
In each of the produced liquid crystal display devices, the case where the polarization axis of polarized light incident on the lower polarizer and the transmission axis of the lower polarizer were aligned was evaluated as A, and the case where they were not aligned was evaluated as C. The results are shown in Table 2. In addition, about the liquid crystal display device without a brightness enhancement film, it described as "-".

<Evaluation of front brightness>
Each of the liquid crystal display devices produced above displayed black (L0) to white (L7), and in each display, the luminance was measured using a measuring instrument (EZ-Contrast XL88, manufactured by ELDIM). The results are shown in Table 2.
Evaluation was made based on the following criteria using the liquid crystal display device of Comparative Example 1 as a reference.
A: 130% or more with respect to the front luminance of the liquid crystal display device of Comparative Example 1.
B: 120% or more and less than 130% with respect to the front luminance of the liquid crystal display device of Comparative Example 1.
C: Less than 120% with respect to the front luminance of the liquid crystal display device of Comparative Example 1.

<< Evaluation of front color >>
Using the measuring device (EZ-Contrast XL88, manufactured by ELDIM) during black display of each of the liquid crystal display devices produced in the dark room, the chromaticity u ′ of each sample at an azimuth angle of 0 ° at a polar angle of 0 ° (each sample) ), V ′ (each sample) was measured, and the difference Δu′v ′ between the chromaticities u ′ (comparative example 1) and v ′ (comparative example 1) of Comparative Example 1 was calculated by the following equation.
Δu′v′φ = √ ((u ′ (Comparative Example 1) −u ′ (each sample)) 2+ (v ′ (Comparative Example 1) −v ′ (each sample)) 2)

Of Δu′v′φ calculated for each azimuth angle, the maximum value was defined as the color change amount Δu′v ′ in the evaluation sample, and evaluation was performed according to the following criteria. The results are shown in Table 2.
A: Δu′v ′ is 0.000 or more and less than 0.003 B: Δu′v ′ is 0.003 or more and less than 0.005 C: Δu′v ′ is 0.005 or more and less than 0.008 D: Δu'v 'is 0.008 or more

<Evaluation of diagonal colors>
Using a measuring device (EZ-Contrast XL88, manufactured by ELDIM) during black display of each of the liquid crystal display devices produced in the dark room, 345 ° counterclockwise from an azimuth angle of 0 ° (horizontal direction) at a polar angle of 60 °. Chromaticity u ', v' is measured in increments of 15 ° until chromaticity at each azimuth angle φ of 60 ° polar angle with respect to chromaticity (u'0, v'0) of polar angle 60 ° and azimuth angle 0 °. The difference Δu′v′φ of (u′φ, v′φ) was calculated by the following formula.
Δu′v′φ = √ ((u′φ−u′0) 2+ (v′φ−v′0) 2)

Of Δu′v′φ calculated for each azimuth angle, the maximum value was defined as the color change amount Δu′v ′ in the evaluation sample, and evaluation was performed according to the following criteria. The results are shown in Table 2.
A: Δu′v ′ is 0.00 or more and less than 0.03 B: Δu′v ′ is 0.03 or more and less than 0.05 C: Δu′v ′ is 0.05 or more and less than 0.08 D: Δu'v 'is 0.08 or more

<< Evaluation of panel warpage >>
Each liquid crystal display device produced above is held for 3 days in an environment of 50 ° C. and a relative humidity of 85%, then moved to an environment of 25 ° C. and a relative humidity of 60%, kept on in a black display state, and visually observed after 4 hours. The light unevenness caused by panel warpage was evaluated according to the following criteria. The results are shown in Table 2.
A: Unevenness is not visually recognized under an environment with an illuminance of 100 lx B: Unevenness is hardly visually recognized under an environment with an illuminance of 100 lx C: Light unevenness is visually recognized under an environment of an illuminance of 100 lx D: Clear under an environment with an illuminance of 100 lx Unevenness is visually recognized E: Clear unevenness is visually recognized in an environment with illuminance of 300 lx

  Example 22 is a system in which the first protective film of the polarizing plate is changed from ZRD 40 to the polyester film 1 with respect to Example 15, but surprisingly, it is at a level where no warping of the panel is recognized. It improved.

<Evaluation of circular unevenness>
Each liquid crystal display device produced above was held for 3 days in an environment of 50 ° C. and 85% relative humidity,
It moved to the environment of 25 degreeC and 60% of relative humidity, continued lighting in the black display state, and observed visually 48 hours later, and evaluated the light nonuniformity on the following reference | standard. The results are shown in Table 2.
A: Unevenness is hardly visually recognized in an environment with an illuminance of 20 lx B: Light unevenness is visually recognized in an environment with an illuminance of 100 lx C: Clear unevenness is visually recognized in an environment with an illuminance of 300 lx

DESCRIPTION OF SYMBOLS 10 Liquid crystal display device 1 Upper polarizer 2 Liquid crystal cell 3 Lower polarizer 4 Support body 5 Optical rotator 6 Optical rotatory film 7 Brightness enhancement film 8 Adhesive or adhesive α Transmission axis of lower polarizer and transmission axis of brightness enhancement film Angle α

Claims (9)

It has an upper polarizer, a liquid crystal cell, a lower polarizer, an optical rotation film, and a brightness enhancement film in this order,
The angle α formed by the transmission axis of the lower polarizer and the transmission axis of the brightness enhancement film is 30 ° to 150 °,
The optical rotation film is an optical rotation film including a support and an optical rotation element,
The dimensional change rate S after heat treatment at 80 ° C. for 24 hours of the optical rotation film satisfies | S | ≦ 0.5,
Retardation Re (550) at a wavelength of 550 nm of the support is 0 nm to 10 nm,
The film thickness of the support is 10 μm to 100 μm,
A liquid crystal display device in which the optical rotator and the brightness enhancement film are arranged via an adhesive or a pressure-sensitive adhesive.   The liquid crystal display device according to claim 1, wherein the optical rotatory element is an optical rotatory element including a retardation layer including a liquid crystalline compound.   The liquid crystal display device according to claim 2, wherein the optical rotatory element is an optical rotatory element including a retardation layer including a chiral agent.   The liquid crystal display device according to claim 2, wherein the liquid crystal compound is a rod-like liquid crystal compound.   4. The liquid crystal display device according to claim 2, wherein the optical rotator includes a laminate of a retardation layer containing a rod-like liquid crystalline compound and a retardation layer containing a discotic liquid crystalline compound.   The liquid crystal display device according to claim 1, wherein the optical rotator is an optical rotator that rotates polarized light incident on the optical rotator within a range of α ± 5 °.   The liquid crystal display device according to claim 4 or 6, wherein an average major axis direction of molecules on the lower polarizer side of the optical rotator is parallel to an absorption axis of the lower polarizer.   The liquid crystal display device according to any one of claims 1 to 7, wherein a retardation Re (550) at a wavelength of 550 nm of the optical rotatory film is 300 nm to 700 nm.   The liquid crystal display device according to claim 1, wherein a film thickness of the optical rotatory element is 1 μm to 5 μm.