JP2007041073A - Liquid crystal display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal that is excellent in antireflection, scratch resistance and durability, has a wide viewing angle, does not give color to reflected light, and provides high contrast with a uniform display in a wide range of observation angles. To provide a display device.
In a VA mode liquid crystal display device having i (i is an integer of 1 or more) biaxial optical anisotropic plates and liquid crystal cells between a pair of polarizers, each biaxial optical In the optical laminated plate (O) formed by laminating all the biaxial optical anisotropic plates and the liquid crystal cells in addition to the specific relationship between the three principal refractive indexes of the anisotropic plates, | R ₄₀ −R ₀ | ≦ 35 nm is satisfied, an antireflection plate is provided on the observation side of the output side polarizer, and the antireflection plate contains specific components (A), (B), and (C). And a low refractive index layer made of a cured film of the product.
[Selection figure] None

Description

    The present invention relates to a liquid crystal display device. More specifically, the present invention is excellent in antireflection, scratch resistance and durability, has a wide viewing angle, does not give color to reflected light, and is high in uniform display over a wide range of observation angles. The present invention relates to a liquid crystal display device having contrast.

    Conventionally, a so-called TN mode in which liquid crystal having positive dielectric anisotropy is horizontally aligned between two substrates is mainly used as a liquid crystal display device (hereinafter sometimes abbreviated as LCD). . However, in such a TN mode, due to its driving characteristics, birefringence occurs due to liquid crystal molecules in the vicinity of the substrate even if black display is attempted. As a result, light leakage occurs and it is difficult to perform complete black display.

    On the other hand, in the vertical alignment mode, so-called vertical alignment (VA) mode, the liquid crystal molecules have a substantially vertical alignment with respect to the substrate surface in a non-driven state, so that light changes the polarization plane of the liquid crystal layer almost. As a result, almost complete black display is possible in a non-driven state by arranging polarizing plates above and below the substrate.

However, in the VA mode, almost complete black display is possible in the panel normal direction, but when the panel is observed from an oblique direction deviating from the normal direction, light leakage occurs due to the influence of the birefringence of the liquid crystal. There is a problem that the viewing angle becomes narrow.
Therefore, in order to obtain a wide viewing angle even in the VA mode, it is necessary to use one or more retardation films as in the TN mode.
For example, (Patent Document 1) discloses an example using a retardation plate that is biaxial in the form of n _x > _ny > _nz and has an in-plane retardation of 120 nm or less.
Further, in (Patent Document 2), a viewing angle is improved by using a biaxial retardation plate _{satisfying nx} > _ny > _nz, and setting the retardation ratio in the in-plane direction and the film thickness direction to 2 or more. In addition to this, an example in which the contrast is further improved by laminating an antiglare layer and an antireflection layer on the viewing side has been reported. This antireflection layer has a desired antireflection effect by laminating two or more high refractive index layers and low refractive index layers. However, this multi-layer antireflection layer has a large wavelength dependency of the antireflection effect, the reflected light is colored, and has a viewing angle dependency. In addition, a large-area multilayer film can be formed using a vacuum device. Has a problem in practical use due to poor productivity.

Japanese Patent No. 3330574 JP 2003-307735 A

    The present invention is excellent in antireflection, scratch resistance and durability, has a wide viewing angle, does not give color to reflected light, and provides a high contrast with a uniform display in a wide range of observation angles. The present invention has been made for the purpose of providing a liquid crystal display device.

As a result of intensive studies to solve the above-mentioned problems, the inventors have made a pair of polarizers composed of an output-side polarizer and an incident-side polarizer whose absorption axes are substantially perpendicular to each other. In the VA mode liquid crystal display device having i pieces (i is an integer of 1 or more) of biaxial optical anisotropic plates and liquid crystal cells between the three main refractions of the respective biaxial optical anisotropic plates. In the optical laminate (O) formed by laminating all of the biaxial optical anisotropic plates and the liquid crystal cells, the ratio is in a specific relationship, and | R ₄₀ −R ₀ | ≦ 35 nm A siloxane which is satisfied and has an antireflection plate on the observation side of the output side polarizer, the antireflection plate having hollow particles (A) having a particle size of 5 to 2000 nm, and a specific functional group in the molecule Acrylation with oligomer (B) and specific functional group in the molecule A display device having a low refractive index layer composed of a cured film of a composition containing the compound (C) has good black display quality from any direction, has a uniform and high contrast, and has an antireflection effect. The present invention has been found to be excellent, and the present invention has been completed based on this finding.
That is, the present invention
(1) Between a pair of polarizers composed of an output-side polarizer and an incident-side polarizer whose respective absorption axes are substantially perpendicular to each other, i (i is an integer of 1 or more) two A VA mode liquid crystal display device having an axial optical anisotropic plate and a liquid crystal cell,
Wherein the principal refractive indices n _x in each side of the biaxial optical anisotropic _plate, n y _(provided that n _x> n _y.), When the main refractive index in the thickness direction is n _{z,
n x>} n y> n _z
Satisfy the relationship
Retardation R ₀ when light having a wavelength of 550 nm is incident from the normal direction when no voltage is applied in the optical laminated plate (O) formed by laminating all the biaxial optical anisotropic plates and the liquid crystal cell. When measuring the retardation R ₄₀ when light having a wavelength of 550 nm is incident from a polar angle of 40 degrees,
| R ₄₀ -R ₀ | ≦ 35 nm
And satisfy the relationship
An antireflection plate is provided on the observation side of the output side polarizer,
This anti-reflection plate
Hollow particles (A) having a particle size of 5 to 2000 nm,
A siloxane oligomer (B) having a (meth) acryloyl group and a fluoroalkyl group, and
Acrylate compound (C) having (meth) acryloyl group
A liquid crystal display device having a low refractive index layer comprising a cured film of a composition comprising
(2) The liquid crystal display device according to (1), wherein a refractive index of the low refractive index layer is 1.40 or less,
(3) When no voltage is applied, the absorption axis of the output-side polarizer or the absorption axis of the incident-side polarizer and the slow axis in the plane of the optical laminated plate (O) are substantially parallel or substantially perpendicular. (1) or the liquid crystal display device according to (2),
Is to provide.

  The liquid crystal display device of the present invention is a method of an optical laminate (O) comprising a biaxial optical anisotropic plate having a specific refractive index, i biaxial optical anisotropic plates and a liquid crystal cell laminated. The difference between the retardation in the linear direction and the retardation at a polar angle of 40 degrees is small, and by providing a low refractive index layer on the observation side of the output side polarizer, the viewing angle is wide, there is no reflection, and the scratch resistance is excellent. , Black display quality is good from any direction, and it has a uniform and high contrast. Further, the slow axis of the optical laminated plate (O) formed by laminating at least one biaxial optical anisotropic plate and a liquid crystal cell has a positional relationship that is substantially parallel or substantially perpendicular to the absorption axis of the polarizer. In addition to compensating for the phase difference caused by the liquid crystal in the liquid crystal cell, the viewing angle of the polarizer can be compensated. Accordingly, it is possible to effectively compensate for the phase difference generated in the light transmitted through the liquid crystal cell to prevent light leakage and to obtain high contrast in all azimuth angles. The liquid crystal display device of the present invention can be suitably used as a large screen flat panel display or the like.

  The liquid crystal display device of the present invention includes a VA mode liquid crystal cell, i biaxial optical anisotropic plates, an exit side polarizer provided with an antireflection plate having a low refractive index layer, and an incident side polarization. It has at least a child.

<Liquid crystal cell>
In the VA mode liquid crystal cell used in the present invention, liquid crystal molecules are aligned substantially perpendicular to the substrate surface when no voltage is applied, and the liquid crystal molecules are aligned horizontally on the substrate surface when a voltage is applied. Specifically, a multi-domain vertical alignment (MVA) system, a patterned vertical alignment (PVA) system, and the like are known.

<Optical anisotropic plate>
Each biaxial optical anisotropic plate used in the present invention, the in-plane refractive index n _x, and n _y, and the refractive index in the thickness direction is n _z, relations of _{n x>} n _y> n _z It is a plate-like substance that has the same size as the display screen of a liquid crystal display device. Incidentally, the slow axis (x) direction indicating the _{n x,} the direction indicated _{n y} the fast axis of (y).
By satisfying the relation of _{n x> n y> n z} , even when viewed from an oblique direction the screen of the liquid crystal display device, there is no light leakage, it is possible to obtain an image of high contrast. Here, the contrast (CR), when the dark display when luminance _{Y OFF} of the liquid crystal display device, the brightness of the bright display time and the _{Y ON,} a value represented by Y ON _{/ Y OFF,} contrast The larger the value, the better the visibility. The bright display is the brightest state of the display screen of the liquid crystal display device, and the dark display is the darkest state of the display screen of the liquid crystal display device.

Each biaxial optical anisotropic plate used in the present invention, a single _layer, n _x> n _y> be those satisfying _{n z relationship,} optically anisotropic having a relation of _{n x>} n y = n _z square and _plate, may be such that to satisfy the relation of _{n x> n y> n z} by laminating an optical anisotropic plate having a relationship of _{n x = n y> n z} .

The biaxial optical anisotropic plate used in the present invention is obtained by stretching a film made of a transparent resin.
The transparent resin can be used without any particular limitation as long as it is a resin having a total light transmittance of 80% or more when a 1 mm thick film is formed.
Specific examples of the transparent resin include polymers having an alicyclic structure, chain olefin polymers such as polyethylene and polypropylene, polycarbonate, polyester, polyethylene terephthalate, polyvinyl chloride, polysulfone, polyethersulfone, polystyrene, polyvinyl alcohol, Examples thereof include cellulose acetates such as polyacrylonitrile, polyarylate, polymethacrylate, and triacetyl cellulose, and (meth) acrylic acid ester-vinyl aromatic compound copolymers. These can be used alone or in combination. Among these, a polymer having an alicyclic structure and a chain olefin polymer are preferable, and a polymer having an alicyclic structure is particularly preferable because of excellent transparency, low hygroscopicity, dimensional stability, lightness, and the like. .

The method for producing the film made of the transparent resin is not particularly limited, and examples thereof include films obtained by a conventionally known method such as a solution casting method or a melt extrusion method. Among them, the melt extrusion method without using a solvent can reduce the content of volatile components, and a film having a large Rth of 100 μm or more can be easily produced. Also, the melt extrusion method is preferable from the viewpoint of production cost. Examples of the melt extrusion method include a method using a die, an inflation method, and the like, but a method using a T die is preferable because it is excellent in productivity and thickness accuracy. Note that Rth is retardation in the thickness direction of the biaxial optical anisotropic plate used in the present invention,
Rth = ((n _x + n _y ) / 2−n _z ) × a value defined by the thickness of the biaxial optical anisotropic plate.

  In the method for producing a film using a T-die, the transparent resin is put into an extruder having a T-die, and the temperature is usually 80 to 180 ° C. higher than the glass transition temperature of the transparent resin, preferably 100 higher than the glass transition temperature. The transparent resin is melted by raising the temperature to ˜150 ° C., the molten resin is extruded from a T die, and the resin is cooled with a cooling roll or the like to form a film. If the melting temperature of the resin is excessively low, the fluidity of the transparent resin may be insufficient, and conversely if excessively high, the transparent resin may deteriorate.

The made of a transparent resin film (hereinafter sometimes referred to as original film.) The method and the condition for stretching a may be appropriately selected from among _{n x>} n _y> n _z becomes a relationship procedures and conditions it can. As a preferable stretching method, a lateral uniaxial stretching method and a biaxial stretching method using a tenter stretching machine can be mentioned.

  Examples of the biaxial stretching method include a method of sequentially biaxial stretching in the vertical direction and the horizontal direction, and a method of biaxial stretching in the vertical direction and the horizontal direction at the same time. Among these, the method of simultaneous biaxial stretching is preferable in that the process can be simplified, the stretched film is difficult to break, and the Rth can be increased.

The simultaneous biaxial stretching method relaxes the stretched film by preheating the raw film (preheating process), biaxially stretching the preheated raw film simultaneously in the machine and transverse directions (stretching process). It has a process (heat setting process).
In the preheating step, the raw film is usually heated to a stretching temperature of −40 ° C. to a stretching temperature of + 20 ° C., preferably a stretching temperature of −30 ° C. to a stretching temperature of + 15 ° C.
In the stretching step, when the glass transition temperature of the transparent resin is Tg, the raw film is preferably stretched while being heated to Tg-30 ° C to Tg + 60 ° C, more preferably Tg-10 ° C to Tg + 50 ° C. The apparatus used for stretching is not particularly limited, and examples thereof include a pantograph type tenter, a screw type tenter, and a linear motor type tenter. The draw ratio is not particularly limited as long as a desired refractive index relationship can be obtained, but is usually 1.3 times or more, preferably 1.3 to 3 times.
In the heat setting step, the stretched film is usually room temperature to stretching temperature + 30 ° C., preferably stretching temperature −40 ° C. to stretching temperature + 20 ° C.

  Examples of the heating means (or temperature adjusting means) in the preheating step, the stretching step, and the heat setting step include an oven-type heating device, a radiation heating device, or a means for immersing in a temperature-adjusted liquid. Of these, an oven-type heating device is preferred. In the oven-type heating device, a method in which hot air is jetted from the nozzle to the upper and lower surfaces of the film is preferable because the temperature distribution in the film surface becomes small.

<Optical laminated plate (O) in which all the biaxial optical anisotropic plates and liquid crystal cells are laminated>
In the optical laminated plate (O) formed by laminating the total number of i biaxial optical anisotropic plates and the liquid crystal cell used in the present invention, light having a wavelength of 550 nm is normal direction when no voltage is applied. Satisfying the relationship of | R ₄₀ −R ₀ | ≦ 35 nm when measuring the retardation R ₀ when the light enters from the direction R, and the retardation R ₄₀ when the light having a wavelength of 550 nm enters from the direction of the polar angle of 40 degrees, Preferably, | R ₄₀ −R ₀ | ≦ 25 nm, and more preferably | R ₄₀ −R ₀ | ≦ 15 nm. When | R ₄₀ −R ₀ | is within the above range, the black display quality is improved and the contrast is improved when the display screen is viewed from an oblique direction. In the present invention, the retardation R ₀ is a retardation when light having a wavelength of 550 nm is incident from the position A (normal direction) as shown in FIG. R ₄₀ is a direction inclined 45 degrees in the plane from the direction of the slow axis (x) of the optical anisotropic plate as shown in FIG. 1 (that is, a direction inclined 45 degrees to the direction of the fast axis (y)), In addition, the retardation is obtained when light having a wavelength of 550 nm is incident from the position B, which is a direction (polar angle) inclined by 40 degrees from the normal line. Note that the polar angle is an angle when viewing the display screen of the liquid crystal display device by tilting from the front direction.

    Retardation is a high-speed spectroscopic ellipsometer [J. A. Woolam, M-2000U] is a value measured by entering light having a wavelength of 550 nm from the position A or B.

<Emission side polarizer and incident side polarizer>
The exit side polarizer and the entrance side polarizer used in the present invention can convert natural light into linearly polarized light. For example, a polarizer obtained by subjecting a film made of a vinyl alcohol polymer such as polyvinyl alcohol or partially formalized polyvinyl alcohol to dyeing, stretching or crosslinking with a dichroic substance such as iodine or a dichroic dye. Can be mentioned. The thicknesses of the exit-side polarizer and the entrance-side polarizer are not particularly limited, but usually a polarizer having a thickness of 5 to 80 μm is preferable. The exit-side polarizer is a polarizer provided closer to the viewing side of the liquid crystal display device of the present invention, and the incident-side polarizer is on the viewing side of the liquid crystal display device of the present invention. It is a polarizer provided in the far side. The observation side of the liquid crystal display device is the side on which the observer can visually recognize the display screen.

  The exit side polarizer and the entrance side polarizer usually have protective films laminated on both sides thereof. As the protective film, a film made of a polymer resin excellent in transparency, mechanical strength, thermal stability, moisture shielding properties and the like can be suitably used. Examples of such polymer resins include polymer resins having an alicyclic structure, cellulose polymer resins such as cellulose diacetate, cellulose triacetate, and cellulose acetate butyrate; polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and the like. The polyester polymer resin may be used. Polymer resin and polyester polymer resin having an alicyclic structure have good transparency, lightness, dimensional stability, and film thickness controllability, and cellulosic polymer resin has good transparency and lightness. Therefore, it can be suitably used.

  Examples of the polymer resin having an alicyclic structure include a norbornene polymer, a monocyclic olefin polymer, and a vinyl alicyclic hydrocarbon polymer. Among these, norbornene-based polymers can be suitably used because they have good transparency and moldability. Examples of the norbornene-based polymer include a ring-opening polymer of a norbornene-based monomer, a ring-opening copolymer of a norbornene-based monomer and another monomer, and a hydrogenated product of these polymers; Examples include addition polymers of monomers, addition copolymers of norbornene monomers and other monomers, and hydrogenated products of these polymers. Among these, a hydrogenated product of a ring-opening polymer or a ring-opening copolymer of a norbornene monomer is particularly preferable because it is excellent in transparency.

  The optical anisotropic plate is preferably used as a protective film for the exit-side polarizer or the entrance-side polarizer. By laminating the optical anisotropic plate on the liquid crystal cell side of the exit side polarizer or the entrance side polarizer, a normal protective film can be omitted, which contributes to thinning of the liquid crystal display device.

As a means for laminating the output side polarizer or the incident side polarizer and the protective film or the optical anisotropic plate, there is usually a method of bonding via an adhesive or a pressure sensitive adhesive. Examples of the adhesive or pressure-sensitive adhesive include acrylic, silicone-based, polyester-based, polyurethane-based, polyether-based, and rubber-based adhesives or pressure-sensitive adhesives. Among these, acrylic adhesives or pressure-sensitive adhesives can be suitably used because of their good heat resistance and transparency.
When bonding, the exit-side polarizer or the entrance-side polarizer, and the protective film or the optical anisotropic plate can be cut out to a desired size and bonded to each other. Or it is preferable to adhere | attach an incident side polarizer, a elongate protective film, or an optical anisotropic plate with a roll-to-roll.

<Antireflection plate>
The liquid crystal display device of the present invention includes an antireflection plate on the observation side of the exit side polarizer. This antireflection plate has a low refractive index layer to be described later. The antireflection plate may have a high refractive index layer between the exit side polarizer and the low refractive index layer.

  In the antireflection plate, the maximum reflectance of light with an incident angle of 5 degrees and a wavelength of 430 nm to 700 nm from the viewing side is usually 1.4% or less, preferably 1.3% or less. The reflectance at a wavelength of 550 nm at an incident angle of 5 degrees is usually 0.7% or less, preferably 0.6% or less. Moreover, the maximum value of the reflectance at a wavelength of 430 nm to 700 nm at an incident angle of 20 degrees is usually 1.5% or less, preferably 1.4% or less. The reflectance at an incident angle of 20 degrees and a wavelength of 550 nm is usually 0.9% or less, preferably 0.8% or less. When each reflectance is in the above range, a liquid crystal display device having excellent visibility without reflection of external light and glare can be obtained. The reflectance can be measured using a spectrophotometer (for example, an ultraviolet-visible near-infrared spectrophotometer V-550, manufactured by JASCO Corporation).

The antireflection plate has a reflectance fluctuation of usually 20% or less, preferably 10% or less, before and after the steel wool test. If the variation in reflectance exceeds 20%, the screen may be blurred or glaring. The steel wool test is a test in which the surface of the low refractive index layer is rubbed back and forth 10 times in a state where a load of 0.025 MPa is applied to steel wool # 0000. The reflectance is measured five times at five arbitrary locations in the plane, and is calculated from the arithmetic average value of these measured values. The change in reflectance before and after the steel wool test was determined by the following formula (I). Rb represents the reflectance before the steel wool test, and Ra represents the reflectance after the steel wool test.
ΔR = (Rb−Ra) / Rb × 100 (%) (I)

Similarly, the antireflection plate has a variation in the total light transmittance before and after the steel wool test, usually within 10%, preferably within 8%, more preferably within 6%. The total light transmittance is measured five times at five locations in the plane, and is calculated from the arithmetic average value of these measured values. The fluctuation of the total light transmittance before and after the steel wool test was determined by the following formula (II). Rc represents the total light transmittance before the steel wool test, and Rd represents the total light transmittance after the steel wool test.
ΔR = (Rc−Rd) / Rc × 100 (%) (II)

In the antireflection plate, the surface resistance on the low refractive index layer side described later is preferably 1.0 × 10 ¹⁰ Ω / □ or less, more preferably 5.0 × 10 ⁹ Ω / □ or less. When the surface resistance is in such a range, dust or the like hardly adheres to the surface of the antireflection plate.

≪High refractive index layer≫
In the reflector used in the present invention, the high refractive index layer may be provided between the exit side polarizer and a low refractive index layer described later, if necessary. The high refractive index layer in the present invention is a layer having a higher refractive index than a low refractive index layer described later.
The refractive index n _{H of the} high refractive index layer is preferably 1.55 or more, and more preferably 1.60 or more. When the refractive index of the high refractive index layer is 1.55 or more, there is an advantage that the antireflection performance and scratch resistance in a wide band are improved and the design of the low refractive index layer laminated on the high refractive index layer becomes easy. is there. The refractive index can be determined using a known spectroscopic ellipsometer or the like.

  The high refractive index layer is a layer having a high surface hardness. Specifically, the high refractive index layer is a layer having a hardness of “HB” or higher in a pencil hardness test defined in JIS K5600-5-4. Although the average thickness of a high refractive index layer is not specifically limited, Usually, 0.5-30 micrometers, Preferably it is 3-15 micrometers.

  The material for forming the high refractive index layer should be selected and used so that the refractive index and surface hardness of the high refractive index layer are in the above-mentioned range, and a material having a high refractive index is preferably used, and a hard material is used. It is preferable. Examples thereof include organic materials such as silicone-based, melamine-based, epoxy-based, acrylic-based and urethane acrylate-based materials; inorganic materials such as silicon dioxide; Among these, urethane acrylate-based and polyfunctional acrylate-based materials can be preferably used because of their high adhesive strength and excellent productivity.

  The high refractive index layer may further contain inorganic oxide particles. By adding inorganic oxide particles to the high refractive index layer, it is possible to easily form a high refractive index layer having excellent surface scratch resistance and a refractive index of 1.55 or more. As the inorganic oxide particles used in the high refractive index layer, those having a high refractive index are preferable, and specifically, those having a refractive index of 1.6 or more, particularly 1.6 to 2.3 are preferable. Examples of such inorganic oxide particles include titania (titanium oxide), zirconia (zirconium oxide), zinc oxide, tin oxide, cerium oxide, antimony pentoxide, antimony-doped tin oxide (ATO), and phosphorus dope. Tin oxide (PTO), fluorine-doped tin oxide (FTO), tin-doped indium oxide (ITO), zinc-doped indium oxide (IZO), aluminum-doped zinc oxide (AZO), etc. be able to. Among these, antimony pentoxide is suitable as a component for adjusting the refractive index because it has a high refractive index and an excellent balance between conductivity and transparency. The primary particle diameter of the inorganic oxide particles is preferably 1 nm to 100 nm, more preferably 1 nm to 30 nm.

  The method for forming the high refractive index layer is not particularly limited. For example, the high refractive index layer can be obtained by applying the material for forming the high refractive index layer, drying, and curing the material. Examples of the substrate include the exit side polarizer and a film made of a resin. Before applying the material, the surface of the substrate may be subjected to plasma treatment, primer treatment, or the like to increase the peel strength of the high refractive index layer. As a curing method, a thermal curing method and an ultraviolet curing method can be used. Moreover, the resin for forming the substrate and the material for the high refractive index layer can be co-extruded to form a co-extruded film in which the resin for forming the substrate and the material are laminated. The surface of the high refractive index layer is preferably provided with an antiglare function. For example, the function can be realized by forming a convex shape on the surface.

≪Low refractive index layer≫
In the reflector used in the present invention, the low refractive index layer used in the present invention is a layer provided on the upper side (observation side) of the output side polarizer, or when the high refractive index layer is provided, It is a layer provided on the upper side of this high refractive index layer. The average thickness of the low refractive index layer is preferably 10 to 1000 nm, and more preferably 30 to 500 nm.

The low refractive index layer is a layer having a refractive index n _L of 1.45 or less, preferably n _L of 1.40 or less, and more preferably n _L of 1.35 to 1.40. . Moreover, it is preferable that the refractive index difference with the said output side polarizer or the said high refractive index layer which adjoins is 0.05-0.4. By providing such a low refractive index layer, it is possible to obtain a liquid crystal display device that is excellent in balance between visibility, scratch resistance, and strength and excellent in balance between antireflection performance and scratch resistance. Further, n _H ≧ 1.53 and (√n _H ) −0.2 <between the refractive index n _H of the high refractive index layer and the refractive index n _L of the low refractive index layer laminated thereon. It is preferable to have a relationship of n _L <(√n _H ) +0.2 in order to develop the antireflection function.

  In the antireflection plate used in the present invention, the low refractive index layer comprises a hollow particle (A) having a particle size of 5 to 2000 nm, a siloxane oligomer (B) having a (meth) acryloyl group and a fluoroalkyl group, and (meta ) A cured film of a composition containing an acrylate compound (C) having an acryloyl group. In the present invention, (meth) acryloyl means acryloyl and methacryloyl.

[Hollow particles (A)]
The hollow particles used in the present invention are particles having a hollow portion.
Further, the solvent used when preparing the hollow particles and / or the gas that enters during the drying may be present in the hollow part of the hollow particles, or a precursor described later for forming the hollow part of the hollow particles. The substance may remain in the hollow part.
The precursor material is a porous material that remains after removing some of the constituent components of the core particles from the core particles surrounded by the outer shell. As the core particles, porous composite oxide particles made of different types of inorganic oxides are used. The precursor material may remain slightly attached to the outer shell, or it may occupy most of the hollow portion of the hollow particles.
The solvent or gas may be present in the pores of the porous material. If the removal amount of the constituent components of the core particles at this time increases, the volume of the hollow part of the hollow particles increases, and hollow particles having a low refractive index are obtained. The transparent film obtained by blending these hollow particles has a low refractive index. Excellent antireflection performance at a high rate.

  The hollow particles (A) contained in the low refractive index layer used in the present invention have a particle size in the range of 5 to 2,000 nm, and preferably in the range of 20 to 100 nm. When the particle size of the hollow particles (A) is below the above range, the refractive index of the low refractive index layer is not sufficiently small, and when the particle size of the hollow particles (A) is within the above range, antireflection is performed. The transparency of the plate can be maintained, and the contribution due to diffuse reflection can be reduced. The particle diameter of the hollow particles here is a number average particle diameter by observation with a transmission electron microscope.

The outer shell of the hollow particle (A) may be porous having pores, or may be one in which the pores are closed and the cavity is sealed against the outside of the outer shell.
The outer shell preferably has a multilayer structure including an inner layer and an outer layer. The outer shell is preferably a plurality of inorganic oxide film layers including an inner first inorganic oxide film layer and an outer second inorganic oxide film layer. By providing the second inorganic oxide coating layer on the outer side, the outer shell can be densified by closing the pores of the outer shell, and hollow particles in which the inner cavity is sealed can be obtained.

  The thickness of the outer shell of the hollow particles (A) is usually 1 to 50 nm, preferably 5 to 20 nm. The thickness of the outer shell of the hollow particles (A) is preferably in the range of 1/50 to 1/5 of the average particle diameter of the hollow particles.

  When the first inorganic oxide coating layer and the second inorganic oxide coating layer are provided as outer shells as described above, the total thickness of these layers may be in the range of 1 to 50 nm. For the densified outer shell, the thickness of the second inorganic oxide coating layer is preferably in the range of 20 to 40 nm.

  Composition comprising the hollow particles (A), the siloxane oligomer (B) having the (meth) acryloyl group and the fluoroalkyl group, and the acrylate compound (C) having the (meth) acryloyl group (coating liquid described later) The content of the hollow particles is not particularly limited, but is preferably 10 to 30% by weight. Within this range, both low refractive index properties and scratch resistance can be achieved.

The hollow particles (A) are preferably inorganic hollow particles, particularly silica-based hollow particles. The inorganic compound constituting the inorganic hollow _{particles, SiO 2, Al 2 O 3} , B 2 O 3, TiO 2, ZrO 2, SnO 2, Ce 2 O 3, P 2 O 5, Sb 2 O 3, MoO 3 _{, ZnO 2, WO 3, TiO} 2 -Al 2 O 3, TiO 2 -ZrO 2, In 2 O 3 -SnO 2, Sb 2 O 3 -SnO 2 or the like can be exemplified. These can be used alone or in combination of two or more.

  The hollow particles can be produced, for example, based on the method described in JP-A-2001-233611. Commercially available hollow particles may also be used. Moreover, in order to improve the bonding property with the siloxane oligomer (B) and the acrylate compound (C) described later, the hollow particles are obtained by reacting the hollow particles with a surfactant or a coupling agent. Hydrophilic groups such as hydroxyl groups and acryloyl groups may be introduced on the surface. As the surfactant or coupling agent, 3,3,3-trifluoropropyltrimethoxysilane, methyl-3,3,3-trifluoropropyldimethoxysilane, heptadecafluorodecylmethyldimethoxysilane, heptadecafluorodecyl Examples thereof include fluorine-containing organosilicon compounds such as trichlorosilane, heptadecafluorodecyltrimethoxysilane, and tridecafluorooctyltrimethoxysilane.

[Siloxane oligomer (B)]
The siloxane oligomer (B) contained in the low refractive index layer used in the present invention is a siloxane oligomer having a (meth) acryloyl group and a fluoroalkyl group. The siloxane oligomer (B) is a compound having a (meth) acryloyl group (b-1), a fluorine compound having a fluoroalkyl group and (b-2), the general formula _{X j SiY 4-j} (wherein, X Represents a monovalent hydrocarbon group which may have a substituent, j represents an integer of 0 to 2, and when j is 2, X may be the same or different. Represents a hydrolyzable group, and Y may be the same or different, and is preferably a condensate with a silane compound (b-3) having a hydrolyzable group.

(B-1) Compound having (meth) acryloyl group As the compound (b-1) having (meth) acryloyl group, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, hydroxyethyl Examples include (meth) acrylate, glycidyl methacrylate, allyl (meth) acrylate, alkyl (meth) acrylates such as 2-ethylhexyl methacrylate, and organosilanes having a (meth) acryloyl group.
Examples of the organosilane having the (meth) acryloyl group include 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, and 3-methacryloxypropylmethyldiethoxysilane. 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane, 3-acryloxypropylmethyldimethoxysilane, 3-acryloxypropylmethyldiethoxysilane, 3-methacryloxymethyltrimethoxysilane, 3-methacrylic Loxymethyltriethoxysilane, 3-methacryloxymethylmethyldimethoxysilane, 3-methacryloxymethylmethyldiethoxysilane, 3-acryloxymethyltrimethoxysilane, 3- Examples include acryloxymethyltriethoxysilane, 3-acryloxymethylmethyldimethoxysilane, 3-acryloxymethylmethyldiethoxysilane, and the like. Among these, 3-methacryloxy is considered due to handling properties, crosslinking density, reactivity, and the like. Propyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-acryloxypropyltrimethoxysilane, and 3-acryloxypropylmethyldimethoxysilane are preferred.

(B-2) Fluorine compound having a fluoroalkyl group As the fluorine compound (b-2) having a fluoroalkyl group, a condensate of a silane compound having a fluoroalkyl group or a monomer having a fluoroalkyl group A copolymer of this and a copolymerizable monomer may be mentioned.

  As the condensate of the silane compound having a fluoroalkyl group, perfluoroalkylalkoxysilane is preferably used from the viewpoint that a siloxane oligomer can be easily formed by a sol-gel reaction.

Examples of the perfluoroalkylalkoxysilane include, for example, the general formula (2): CF ₃ (CF ₂ ) _n CH ₂ CH ₂ Si (OR ′) ₃ (wherein R ′ is an alkyl having 1 to 5 carbon atoms. And n represents an integer of 0 to 12). Specifically, for example, trifluoropropyltrimethoxysilane, trifluoropropyltriethoxysilane, tridecafluorooctyltrimethoxysilane, tridecafluorooctyltriethoxysilane, heptadecafluorodecyltrimethoxysilane, heptadecafluorodecyltri Examples thereof include ethoxysilane. Among these, the compound wherein n is 2 to 6 is preferable. These can be used alone or in combination of two or more.

  Examples of the monomer having a fluoroalkyl group include fluoroolefins such as tetrafluoroethylene, hexafluoropropylene and 3,3,3-trifluoropropylene; perfluoro (methyl vinyl ether), perfluoro (ethyl vinyl ether), perfluoro (propyl). Examples include perfluoro (alkyl vinyl ethers) such as vinyl ether), perfluoro (butyl vinyl ether), and perfluoro (isobutyl vinyl ether); perfluoro (alkoxyalkyl vinyl ether) such as perfluoro (propoxypropyl vinyl ether); and the like. These can be used alone or in combination of two or more.

  Examples of the monomer copolymerizable with the monomer having a fluoroalkyl group include vinyl ether compounds such as methyl vinyl ether, ethyl vinyl ether and allyl vinyl ether, vinyl ester compounds such as vinyl acetate and vinyl butyrate, methyl (meth) acrylate, (Meth) acrylate compounds such as ethyl (meth) acrylate, hydroxyethyl (meth) acrylate, styrene compounds such as styrene and p-hydroxymethylstyrene, unsaturated carboxylic acid compounds such as crotonic acid, maleic acid and itaconic acid, and These derivatives can be mentioned.

(B-3) formula _X j _SiY silane compound the having a hydrolyzable group represented by _4-j, a silane compound having a hydrolyzable group represented by the general formula _{X j SiY 4-j} (b- In 3), X represents a monovalent hydrocarbon group which may have a substituent. Examples of the monovalent hydrocarbon group which may have a substituent include alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group and octyl group; cyclopentyl group and cyclohexyl group A cycloalkyl group such as a phenyl group, a 4-methylphenyl group, a 1-naphthyl group, a 2-naphthyl group, an aryl group which may have a substituent, an alkenyl group such as a vinyl group or an allyl group, a benzyl group, Aralkyl groups such as phenethyl group and 3-phenylpropyl group; haloalkyl groups such as chloromethyl group, γ-chloropropyl group and 3,3,3-trifluoropropyl group; alkenylcarbonyloxyalkyl such as γ-methacryloxypropyl group Group: alkyl group having an epoxy group such as γ-glycidoxypropyl group or 3,4-epoxycyclohexylethyl group Alkyl group having an amino group such as 3-aminopropyl group; an alkyl group having a mercapto group such as γ- mercaptopropyl group include a perfluoroalkyl group such as trifluoromethyl group. Among these, an alkyl group having 1 to 4 carbon atoms, a phenyl group, and a perfluoroalkyl group are preferable from the viewpoint of easy synthesis and availability.

Y represents a hydrolyzable group. The hydrolyzable group is a group that is hydrolyzed in the presence of an acid or a base catalyst as desired to give a — (O—Si) —O— bond. Specific examples of the hydrolyzable group include alkoxyl groups such as methoxy group, ethoxy group and propoxy group; acyloxy groups such as acetoxy group and propionyloxy group; oxime group (—O—N═C—R ¹ (R ² ) ), Enoxy group (—O—C (R ¹ ) = C (R ² ) R ³ ), amino group, aminoxy group (—O—N (R ¹ ) R ² ), amide group (—N (R ¹ )) -C (= O) -R ^2), and the like. In these groups, R ¹ , R ² and R ³ each independently represent a hydrogen atom or a monovalent hydrocarbon group. Among these, as Y, an alkoxyl group is preferable from the viewpoint of availability.

The general formula _{X j SiY 4-j} with a silane compound expressed (b-3), a silicon compound wherein k is an integer of 0 to 2 is preferred. Specific examples thereof include alkoxysilanes, acetoxysilanes, oxime silanes, enoxysilanes, aminosilanes, aminoxysilanes, amidosilanes and the like. Among these, alkoxysilanes are more preferable from the viewpoint of availability.

  Examples of the tetraalkoxysilane in which j is 0 include tetramethoxysilane and tetraethoxysilane. Examples of the organotrialkoxysilane in which j is 1 include methyltrimethoxysilane, methyltriethoxysilane, and methyltriisosilane. Examples include propoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane and the like. Examples of the diorganodialkoxysilane in which j is 2 include dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, and methylphenyldimethoxysilane.

  Although the compounding quantity of a siloxane oligomer (B) is not specifically limited, It is preferable that it is 3-90 weight% with respect to the said composition (coating liquid mentioned later), and it is preferable that it is 5-80 weight%. 10 to 60% by weight is preferable. When it is within the above range, the refractive index of the low refractive index layer becomes an appropriate value, a sufficient antireflection effect is obtained, and the scratch resistance of the low refractive index layer is good.

  Although there is no restriction | limiting in particular about the molecular weight of a siloxane oligomer (B), The number average molecular weight (Mn) of polystyrene (standard solution) conversion measured with the gel permeation chromatograph using a cyclohexane as a solvent must be 5000 or more. preferable.

As a method for obtaining the siloxane oligomer (B), the compound (b-1) having the (meth) acryloyl group, the fluorine compound (b-2) having the fluoroalkyl group, and the silane compound (b-3). Can be obtained by condensation.
In the condensation, the ratio of each reaction component is not particularly limited, but is 5 to 70/30 to 70 in terms of a molar ratio of the compound (b-1) / the compound (b-2) / the compound (b-3). It is preferable to mix and condense so that it may become / 1-50 mol%, It is still more preferable to mix | blend and condense so that it may become 5-70 / 30-70 / 1-50 mol%. Furthermore, in the condensation, each reaction component is preferably heated in an alcohol solvent (eg, methanol, ethanol, etc.) in the presence of an organic acid (eg, oxalic acid, etc.).

[Acrylate compound (C)]
The acrylate compound (C) contained in the low refractive index layer used in the present invention has a (meth) acryloyl group.
From the viewpoint of effectively increasing the hardness of the antireflection plate, the acrylate compound (C) preferably does not contain a fluorine atom and has two or more (meth) acryloyl groups. Such compounds include neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolethane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, Dipentaerythritol tetra (meth) acrylate, alkyl-modified dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, alkyl-modified dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, caprolactone Examples include modified dipentaerythritol hexa (meth) acrylate and ditrimethylolpropane tetra (meth) acrylate. Kill. These can be used alone or in combination of two or more.

  The acrylate compound (C) may contain a fluorine atom from the viewpoint of effectively reducing the refractive index of the low refractive index layer. Examples of acrylate compounds containing fluorine atoms include 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3,3-pentafluoropropyl (meth) acrylate, and 2- (perfluorobutyl) ethyl. (Meth) acrylate, 3-perfluorobutyl-2-hydroxypropyl (meth) acrylate, 2- (perfluorohexyl) ethyl (meth) acrylate, 3-perfluorohexyl-2-hydroxypropyl (meth) acrylate, 2- (Perfluorooctyl) ethyl (meth) acrylate, 3-perfluorooctyl-2-hydroxypropyl (meth) acrylate, 2- (perfluorodecyl) ethyl (meth) acrylate, 2- (perfluoro-3-methylbutyl) ethyl (Meth) acrylate, 3- (par Fluoro-3-methylbutyl) -2-hydroxypropyl (meth) acrylate, 2- (perfluoro-5-methylhexyl) ethyl (meth) acrylate, 3- (perfluoro-5-methylhexyl) -2-hydroxypropyl ( (Meth) acrylate, 2- (perfluoro-7-methyloctyl) ethyl (meth) acrylate, 2- (perfluoro-7-methyloctyl) -2-hydroxypropyl (meth) acrylate, 1H, 1H, 3H-tetrafluoro Propyl (meth) acrylate, 1H, 1H, 5H-octafluoropentyl (meth) acrylate, 1H, 1H, 7H-dodecafluoroheptyl (meth) acrylate, 1H, 1H, 9H-hexadecafluorononyl (meth) acrylate, 1H -1- (trifluoromethyl) Lifluoroethyl (meth) acrylate, 1H, 1H, 3H-hexafluorobutyl (meth) acrylate, 2,2,3,3,4,4,5,5,6,6,7,7,8,8, Mention may be made of 9,9-hexadecafluoro-1,10-decandiol-diepoxy (meth) acrylate. These can be used alone or in combination of two or more.

  Although the compounding quantity of an acrylate compound (C) is not specifically limited, It is preferable that it is 5-90 weight% with respect to the said composition (coating liquid mentioned later), and it is preferable that it is 10-80 weight%. It is preferably 15 to 60% by weight. When it is within the above range, the refractive index of the low refractive index layer becomes an appropriate value, a sufficient antireflection effect is obtained, and the scratch resistance of the low refractive index layer is good.

  The low refractive index layer used in the present invention is a coating liquid (composition) containing the hollow particles (A), the siloxane oligomer (B), and the acrylate compound (C). It can be obtained by coating in the form of a film on another layer such as a refractive index layer, drying, and curing by ionizing radiation and / or heating.

  The said coating liquid mixes the said (A), (B), and (C) with the organic solvent which does not decompose | disassemble a hollow particle (A), a siloxane oligomer (B), and an acrylate compound (C). To be prepared. Examples of such organic solvents include alcohols such as isopropyl alcohol, methanol, and ethanol; ketones such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; esters such as ethyl acetate and butyl acetate; halogenated hydrocarbons; toluene, xylene, and the like Or aromatic hydrocarbons thereof; or mixtures thereof. The mixing ratio of the organic solvent and the (A), (B), and (C) is not particularly limited, but in the coating solution, the (A), (B), and (C) It is preferable to mix so that the total concentration is 0.1 to 20% by weight, preferably 0.5 to 10% by weight.

  The coating liquid contains a polymerization initiator (photo radical initiator or thermal radical initiator), a curing agent, a crosslinking agent, an ultraviolet blocker, an ultraviolet absorber, a surface conditioner (leveling agent), or other components. It may be included.

The coating method of the coating liquid is not particularly limited. Examples of the curing method include heating and actinic ray irradiation. Drying conditions and curing conditions can be appropriately determined according to the type of solvent used, such as boiling point and saturated vapor pressure. In particular, in order to suppress the other layers to be coated from being colored or decomposed, it is preferable to heat at a temperature within the range of 50 to 150 ° C. for 1 to 180 minutes. It is more preferable to heat at a temperature in the range of 75 to 105 ° C. for 5 to 60 minutes, and when irradiating actinic rays, it is preferable to use ultraviolet rays as the irradiation light. The irradiation energy is preferably from 50 to 500 mJ / cm ^2, more preferably 100~450mJ / cm ^2, further preferably 200 to 400 mJ / cm ^2.

≪Anti-fouling layer≫
In the antireflection plate used in the present invention, an antifouling layer may be further formed on the low refractive index layer (observation side) in order to enhance the antifouling property of the low refractive index layer. The material for forming the antifouling layer is not particularly limited as long as the function of the low refractive index layer is not impaired and the required performance as the antifouling layer is satisfied. Usually, a compound having a hydrophobic group can be preferably used. As specific examples, a perfluoroalkylsilane compound, a perfluoropolyethersilane compound, or a fluorine-containing silicone compound can be used. As the method for forming the antifouling layer, for example, a physical vapor deposition method such as vapor deposition or sputtering; a chemical vapor deposition method such as CVD; a wet coating method; The thickness of the antifouling layer is not particularly limited, but is usually preferably 20 nm or less, and more preferably 1 to 10 nm.

<Arrangement configuration of liquid crystal display device>
Here, an outline of the configuration of the liquid crystal display device of the present invention will be described.
In the liquid crystal display device of the present invention, there is no particular limitation as long as it is an arrangement having at least one optical anisotropic plate and a liquid crystal cell between the exit side polarizer and the entrance side polarizer.
2 and 3 are explanatory diagrams showing examples of the configuration of the liquid crystal display device of the present invention. The arrows in the figure represent the absorption axis for the polarizer and the in-plane slow axis for the biaxial optical anisotropic plate.
In FIG. 2, in the liquid crystal display device, an incident side polarizer 11, a biaxial optical anisotropic plate 12, a liquid crystal cell 13, an output side polarizer 14, and an antireflection plate 15 are stacked in this order. The slow axis in the plane of the biaxial optical anisotropic plate is in a positional relationship perpendicular to the absorption axis of the incident side polarizer. On the observation side of the exit-side polarizer 5, an antireflection plate having a low refractive index layer is provided.

  When there are two optical anisotropic plates used in the liquid crystal display device of the present invention, the optical anisotropic body-liquid crystal cell-optical anisotropic plate, optical anisotropic plate from the incident side polarizer toward the output side polarizer. Any arrangement of plate-optically anisotropic plate-liquid crystal cell or liquid crystal cell-optically anisotropic plate-optically anisotropic plate can be used. FIG. 3 shows an example. As shown in FIG. 3, the incident side polarizer 1, the optical anisotropic plate 2, the liquid crystal cell 3, the optical anisotropic plate 4, the output side polarizer 5, and the antireflection plate 6 are stacked in this order. The slow axis in the plane of the optical anisotropic plate 4 is parallel to the absorption axis of the incident side polarizer, and the slow axis in the plane of the optical anisotropic plate 2 is the absorption axis of the output side polarizer. And a parallel positional relationship.

In a preferred liquid crystal display device of the present invention, in the state where no voltage is applied, the absorption axis of the output-side polarizer or the absorption axis of the incident-side polarizer, at least one biaxial optical anisotropic plate, and the liquid crystal The slow axis in the plane of the optical laminate (O) formed by laminating the cells is substantially parallel or substantially perpendicular. “Substantially parallel” means that when the angle is displayed at 0 to 90 degrees, the angle between the two axes is 0 to 3 degrees, more preferably 0 to 1 degree. Means an angle of 87 to 90 degrees, more preferably 89 to 90 degrees. An optical laminated plate obtained by laminating the absorption axis of the output-side polarizer or the absorption axis of the incident-side polarizer, at least one biaxial optical anisotropic plate, and the liquid crystal cell in a state where no voltage is applied. When the angle formed by the slow axis in the plane (O) is within the above range, the black display quality is improved. The direction of the slow axis in the plane of the optical laminated plate (O) formed by laminating at least one of the biaxial optical anisotropic plate and the liquid crystal cell in the state where no voltage is applied is when R ₀ is measured. Can be requested.

  The exit-side polarizer and the entrance-side polarizer used in the liquid crystal display device of the present invention have a positional relationship in which their absorption axes are substantially vertical. When the angle formed by the two axes of the incident side polarizer and the output side polarizer is within the above range, the black display quality of the display screen of the liquid crystal display device is improved.

  The liquid crystal display device of the present invention includes the low refractive index layer on the observation side of the output side polarizer. Preferably, the high refractive index layer and the low refractive index layer are provided in this order from the exit side polarizer toward the observation side (that is, the high refractive index layer and the low refractive index layer are liquid crystal from the observation side. An array of a low refractive index layer, a high refractive index layer, and an exit-side polarizer can be formed toward the cell). By providing the low refractive index layer on the observation side of the output side polarizer, the contrast of the liquid crystal display device of the present invention can be further effectively improved.

In the liquid crystal display device of the present invention, other films or layers may be provided in addition to the exit side polarizer, the entrance side polarizer, the optical anisotropic plate, the liquid crystal cell, and the antireflection plate. For example, a prism array sheet, a lens array sheet, a light diffusing plate, a light guide plate, a diffusing sheet, a brightness enhancement film, and the like can be arranged in one or more layers at appropriate positions. In the liquid crystal display device of the present invention, a cold cathode tube, a mercury flat lamp, a light emitting diode, electroluminescence, or the like can be used as a backlight.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.
In the following Examples and Comparative Examples, a vertical alignment mode liquid crystal cell having a thickness of 2.74 μm, a positive dielectric anisotropy, a birefringence of Δn = 0.09884 at a wavelength of 550 nm, and a pretilt angle of 90 degrees was manufactured. did.
In Examples and Comparative Examples, measurement and evaluation were performed by the following methods.
(1) Thickness After embedding the optical laminate in epoxy resin, slice it to a thickness of 0.05 μm using a microtome [Daiwa Koki Kogyo Co., Ltd., RUB-2100], and cross section using a transmission electron microscope. Observe and measure. About an optical laminated board, it measures for every layer.
(2) Main refractive index of optical anisotropic plate Using an automatic birefringence meter [Oji Scientific Instruments Co., Ltd., KOBRA-21], under conditions of temperature 20 ° C. ± 2 ° C. and humidity 60 ± 5%, wavelength 550 nm the light, measuring the refractive indices n _x in the slow axis direction in a _plane, the refractive index n _y in the slow axis direction and in-plane perpendicular directions in the _plane, the refractive index n _z in the thickness direction.
(3) Retardation High-speed spectroscopic ellipsometer [J. A. Using Woollam, M-2000U], R ₀ and R ₄₀ are measured under conditions of a temperature of 20 ° C. ± 2 ° C. and a humidity of 60 ± 5%.
(4) Viewing angle characteristics With the background of the screen of the liquid crystal display device set to black, white characters are displayed on the screen to display the screen from the front and diagonal directions within a polar angle of 80 degrees. Observe visually.
○: White characters can be read
×: Characters cannot be read (5) Contrast ratio The liquid crystal display device is installed in an environment with an ambient brightness of 100 lux, and the brightness at 5 degrees from the front when the display screen is dark and bright is displayed. It measures using a luminance meter (Topcon company make, color luminance meter BM-7). Then, the ratio between the brightness of bright display and the brightness of dark display (= brightness of bright display / brightness of dark display) is calculated, and this is used as contrast (CR). The greater the contrast (CR), the better the visibility.
(6) Reflectance Using a spectrophotometer [Nippon Bunko Co., Ltd., UV-visible near-infrared spectrophotometer V-570]], the reflection spectrum was measured at an incident angle of 5 degrees, and the reflectance in light having a wavelength of 550 nm was measured. Ask.
(7) Refractive index of low refractive index layer and high refractive index layer High-speed spectroscopic ellipsometer [J. A. Woollam, M-2000U], spectrum at a wavelength range of 400 to 1000 nm when measured at 20 ° C. ± 2 ° C. and humidity 60 ± 5% at incident angles of 55, 60 and 65 degrees, respectively. Calculate from
(8) Scratch resistance The surface is reciprocated 10 times in a state where a load of 0.025 MPa is applied to steel wool # 0000, and the surface state after the test is visually observed.
○: Scratches are not recognized
Δ: Slightly scratched
X: Scratches are recognized (9) Visibility In the state where the display screen of the liquid crystal display device is black, the display on the screen is visually observed, and the following three-stage evaluation is performed.
○: No glare or reflection
Δ: Some glare and reflections can be seen
X: Glare and reflection can be seen (10) Broadband property A liquid crystal display device is installed in an environment with a brightness of 100 lux, and the reflected color is visually observed.
○: Reflection color is black
X: Reflection color is blue (11) number average molecular weight and weight average molecular weight A gel permeation chromatograph [Tosoh Corporation, HLC8020] is used to prepare a calibration curve with a standard solution and measured as a converted value.
(12) Antifouling property When a magic ink (trade name: McKee, manufactured by ZEBRA) is attached to the surface of the antireflection plate and then wiped with a cellulose nonwoven fabric (trade name: Bencott M-3, manufactured by Asahi Kasei). Visually judge the condition.
○: Can be completely wiped off
×: Wipe marks remain

(Production Example 1) (Preparation of raw film)
A pellet of a norbornene polymer (trade name: ZEONOR 1420R, manufactured by Nippon Zeon Co., Ltd., glass transition temperature: 136 ° C., saturated water absorption: less than 0.01% by weight) is 110 using a hot air dryer in which air is circulated. Dry at 4 ° C. for 4 hours. Then, a short disk extrusion having a coat hanger type T-die having a lip width of 650 mm with an average surface roughness Ra = 0.04 μm, in which a leaf disk-shaped polymer filter (filtration accuracy of 30 μm) is installed, and the tip of the die lip is chrome-plated Using a machine, the pellets were melt extruded at 260 ° C. to obtain an original film having a thickness of 200 μm and a width of 600 mm.

(Production Example 2) (Production of optical anisotropic plate 1)
The raw film obtained in Production Example 1 was subjected to simultaneous biaxial stretching using an oven temperature (preheating temperature, stretching temperature, heat setting temperature) of 138 ° C., a film feeding speed of 1 m / min, and a chuck moving accuracy within ± 1%. Simultaneous biaxial stretching was performed at a longitudinal stretching ratio of 1.41 times and a lateral stretching ratio of 1.41 times to obtain an optical anisotropic plate 1 having a thickness of 100 μm. The resulting principal refractive index of the optically anisotropic plate _{1, n x = 1.53068, n y} = 1.53018, were n z = 1.52913.

(Production Example 3) (Production of optical anisotropic plate 2)
An optical anisotropic plate 2 having a thickness of 100 μm was obtained by performing the same operation as in Production Example 2 except that the oven temperature was set to 134 ° C. in Production Example 2. The resulting principal refractive index of the optically anisotropic plate _{2, n x = 1.53108, n y} = 1.53038, were n z = 1.52853.

(Production Example 4) (Preparation of composition H1 for forming a high refractive layer)
Hexafunctional urethane acrylate oligomer (trade name: NK Oligo U-6HA, Shin-Nakamura Chemical Co., Ltd.) 30 parts, butyl acrylate 40 parts, isoboronyl methacrylate (trade name: NK Ester IB, Shin-Nakamura Chemical Co., Ltd.) 30 parts, 5 parts of styrene beads (particle size 3.5 μm) and 10 parts of 2,2-diphenylethane-1-one were mixed with a homogenizer, and a 40 wt% MIBK solution of antimony pentoxide fine particles (average particle diameter 20 nm: the hydroxyl group is a pyrochlore structure) Are bonded at a ratio of 1 to the antimony atoms appearing on the surface of the coating layer in such a ratio that the weight of the antimony pentoxide fine particles accounts for 50% by weight of the total solids of the coating liquid for forming a high refractive index layer. A composition H1 for forming a high refractive index layer was prepared.

(Production Example 5) (Adjustment of composition L1 for forming a low refractive index layer)
200 parts of ethanol was put into a four-necked reaction flask equipped with a reflux tube, and 120 parts of oxalic acid was added little by little to this ethanol with stirring to prepare an ethanol solution of oxalic acid. The solution was then heated to its reflux temperature, and 50 parts of 3-acryloxypropyltrimethoxysilane (compound (b-1)), heptadecafluorooctylethyltrimethoxysilane (compound (b -2)) 50 parts, 10 parts tetramethoxysilane (compound (b-3)), 20 parts dipentaerythritol hexaacrylate (acrylate compound (C)) and 2-hydroxy-2-methyl-1-phenylpropane-1 -5 parts of ON (polymerization initiator) was added dropwise with stirring and mixing. Even after completion of the dropwise addition, heating was continued for 5 hours under reflux, followed by cooling.
Next, a hollow silica isopropanol dispersion sol (manufactured by Catalyst Kasei Kogyo Co., Ltd., solid content 20% by weight, average primary particle diameter of about 35 nm, outer shell thickness of about 8 nm) (hollow particles (A)) Was added so that the solid content was 70% by weight, and diluted with methanol so that the solid content was 1% by weight, to prepare a composition L1 for forming a low refractive index layer.

(Production Example 6) (Adjustment of composition L2 for forming a low refractive index layer)
Low refractive index in the same manner as in Production Example 5 except that 20 parts of 3- (perfluorooctyl) ethyl acrylate (acrylate compound (C)), which is a fluorine-containing acrylate compound, was used instead of dipentaerythritol hexaacrylate. A rate layer forming composition L2 was prepared.

(Production Example 7) (Adjustment of composition L3 for forming a low refractive index layer)
A composition for forming a low refractive index layer in the same manner as in Production Example 5, except that 60 parts of tetramethoxysilane which is a siloxane oligomer having no fluoroalkyl group is used instead of 50 parts of heptadecafluorooctylethyltrimethoxysilane. L3 was prepared.

(Production Example 8) (Adjustment of composition L4 for forming a low refractive index layer)
412 parts of methanol was added to 152 parts of tetramethoxysilane, 18 parts of water and 18 parts of 0.01N hydrochloric acid were mixed, and this was mixed well using a disper. The mixture was stirred for 2 hours in a constant temperature bath at 25 ° C., and the weight average molecular weight was adjusted to 850 to obtain a silicone resin. Next, silica methanol sol (Nissan Chemical Industries, Ltd., PMA-ST, average particle size of 10 to 20 nm), which is a non-hollow particle, is added to this silicone resin solution in a weight ratio of silica methanol sol / silicone based on solid content. The resin (condensed compound equivalent) was added so as to be 80/20, and further diluted with methanol so that the total solid content was 3%, to prepare a composition L4 for forming a low refractive index layer.

(Production Example 9) (Production of Polarizer)
A 85 μm-thick PVA film [Kuraray Co., Ltd., Vinylon # 8500] is attached to the chuck, stretched 2.5 times, and heated to 30 ° C. in an aqueous solution containing 0.2 g / L iodine and 60 g / L potassium iodide. And then immersed in an aqueous solution containing 70 g / L of boric acid and 30 g / L of potassium iodide, and uniaxially stretched 6.0 times in this state and held for 5 minutes. Finally, it was dried at room temperature for 24 hours to obtain a polarizer having an average thickness of 30 μm and a polarization degree of 99.5%.

(Production Example 10) (Production of Polarizer P)
Triacetyl cellulose film [Konica Minolta (Ltd.), KC8UX2M] on one surface of a 1.5 mol / L isopropyl alcohol solution of potassium hydroxide 25 mL / ^{m 2} was applied, and dried for 5 seconds at 25 ° C.. Next, the film was washed with running water for 10 seconds, and the surface of the film was dried by blowing air at 25 ° C. In this way, only one surface of the triacetylcellulose film was saponified.
The surface of the saponified film is laminated on one side of the polarizer obtained in Production Example 9 and bonded by a roll-to-roll method using a polyvinyl alcohol adhesive, and triacetylcellulose is applied to the incident side of the polarizer. Films were laminated to obtain a polarizer P.

(Production Example 11) (Preparation of polarizing plate with low refractive index layer (TAC substrate))
One side of a triacetyl cellulose film (KC8UX2M) manufactured by Konica Minolta Co., Ltd. was coated with 25 ml / m ^{2 of} 1.5 N potassium hydroxide in isopropyl alcohol and dried at 25 ° C. for 5 seconds. The surface of the film was dried by washing with running water for 10 seconds and blowing air at 25 ° C. In this way, only one surface of the triacetylcellulose film was saponified.
On the other side, a double-sided substrate film having a surface tension of 0.055 N / m is obtained by performing a corona discharge treatment with an output of 0.8 kW using a high-frequency transmitter (high-frequency power supply AGI-024 manufactured by Kasuga Electric Co., Ltd.). Obtained.
Next, the composition H1 for forming a high refractive index layer obtained in Production Example 4 was applied to the surface of the base film subjected to corona discharge treatment using a die coater, and then dried in an oven at 80 ° C. And dried for 5 minutes to obtain a film. Then, the laminated film 1A which irradiated with the ultraviolet-ray (integrated irradiation amount 300mJ / cm < ² >) and laminated | stacked the high refractive index layer of thickness 5 micrometers was obtained. The refractive index of the high refractive index layer was 1.62.
The low refractive index layer-forming composition L1 obtained in Production Example 5 is applied to the laminated film 1A on the high refractive index layer side with a wire bar coater, and left to stand for 1 hour to dry. Is heated at 120 ° C. for 10 minutes in an oxygen atmosphere, and then the laminated film is irradiated with ultraviolet rays so that the cumulative amount of ultraviolet rays is 400 mJ / cm ² from the coating side, and the low refractive index obtained by laminating a low refractive index layer having a thickness of 100 nm. A base material with a rate layer (TAC base material) was obtained. Roll-to-roll using a polyvinyl alcohol-based adhesive so that the saponified surface of the obtained base material with a low refractive index layer (TAC base material) overlaps one side of the polarizer obtained in Production Example 9. By laminating by the method, a polarizing plate with a low refractive index layer (TAC substrate) 2A was obtained. The pencil hardness was 2H.

(Production Example 12) (Preparation of polarizing plate with low refractive index layer (COP substrate))
On both surfaces of the raw film obtained in Production Example 1, corona discharge treatment was performed at a power of 0.8 KW using a high frequency transmitter (high frequency power supply AGI-024 manufactured by Kasuga Denki Co., Ltd.), and the surface tension was 0.072 N / m base film was obtained.
Next, the high refractive index layer forming composition H1 obtained in Production Example 4 was applied to one side of the base film using a die coater and dried in a drying furnace at 80 ° C. for 5 minutes. A coating was obtained. Then, the laminated film 1B which irradiated with the ultraviolet-ray (integrated irradiation amount 300mJ / cm < ² >) and laminated | stacked the high refractive index layer of thickness 5 micrometers was obtained. The refractive index of the high refractive index layer was 1.62.
The low refractive index layer-forming composition L2 obtained in Production Example 5 is applied to the high refractive index layer side of the laminated film 1B with a wire bar coater, left to stand for 1 hour, and dried. The film was heat treated at 120 ° C. for 10 minutes in an oxygen atmosphere, and then the laminated film was irradiated with ultraviolet rays so that the accumulated ultraviolet light amount was 400 mJ / cm ² from the coating side, and a low refractive index layer having a thickness of 100 nm was laminated. A base material with a refractive index layer (COP base material) was obtained. Acrylic adhesive so that the surface of the obtained low refractive index layer-attached base material (COP base material) on which the low refractive index layer is not laminated overlaps one side of the polarizer obtained in Production Example 9. Were bonded together by a roll-to-roll method to obtain a polarizing plate with a low refractive index layer (COP substrate) 2C. The pencil hardness was H.

Example 1 (Production of Liquid Crystal Display Device 1)
Optical anisotropic plate 1 obtained in Production Example 2 (referred to as optical anisotropic plate 1a), VA mode liquid crystal cell (thickness 2.74 μm, positive dielectric anisotropy, wavelength 550 nm birefringence Δn = 0.09884) , A pretilt angle of 90 degrees) and another optical anisotropic plate 1 (referred to as an optical anisotropic plate 1b), the slow axis of the optical anisotropic plate 1a and the slow axis of the optical anisotropic plate 1b. The optical laminated plate 1 was produced by laminating in this order so as to be vertical.
Retardation _{R 0} when light of wavelength 550nm is incident perpendicularly of the obtained optical laminate 1 is 2 nm, retardation _{R 40} when light of wavelength 550nm is incident polar angle 40 degrees, 13 nm met It was. | R ₄₀ −R ₀ | was 11 nm.
Subsequently, the surface of the polarizer P obtained in Production Example 10 in which the absorption axis of the polarizer P and the slow axis of the optical anisotropic plate 1a are perpendicular and the protective film is not laminated is the optical anisotropic plate 1a. And laminated with the optical laminated plate 1 so as to be in contact with each other.
Furthermore, the polarizing plate with a low refractive index layer (TAC base material) 2A obtained in Production Example 11 is compared with the slow axis of the optical anisotropic plate 1b and the absorption axis of the polarizing plate with low refractive index layer (TAC base material) 2A. Is laminated with the optical laminated plate 1 so that the surface of the polarizing plate with a low refractive index layer (TAC substrate) 2A on which the low refractive index layer is not laminated is in contact with the optical anisotropic plate 1b, A liquid crystal display device 1 was produced. At this time, the polarizing plate with a low refractive index layer was placed on the observation side of the liquid crystal display device. The evaluation results of the manufactured liquid crystal display device 1 are shown in Table 1.

(Example 2) (Production of liquid crystal display device 2)
In Production Example 11, the low refractive index layer-forming composition L2 obtained in Production Example 6 was used instead of the low refractive index layer-forming composition L1, and the low refractive index was produced in the same manner as in Production Example 11. A polarizing plate with a layer (TAC substrate) 2B was obtained.
Next, in Example 1, in place of the polarizing plate with a low refractive index layer (TAC substrate) 2A, a liquid crystal was produced in the same manner as in Example 1 except that this polarizing plate with a low refractive index layer (TAC substrate) 2B was used. A display device 2 was obtained. The evaluation results of the manufactured liquid crystal display device 2 are shown in Table 1.

(Example 3) (Production of liquid crystal display device 3)
Example 1 except that the polarizing plate with a low refractive index layer (TAC substrate) 2A obtained in Production Example 12 was used instead of the polarizing plate with a low refractive index layer (TAC substrate) 2A in Example 1. A liquid crystal display device 3 was obtained in the same manner. The evaluation results of the manufactured liquid crystal display device 3 are shown in Table 1.

Example 4 (Production of liquid crystal display device 4)
Instead of the optical anisotropic plate 1b, a triacetylcellulose film (nx = 1.48020, ny = 1.48014, nz = 1.479967) having a thickness of 80 μm was used, and in Production Example 3 instead of the optical anisotropic plate 1a, An optical laminated plate 2 was produced in the same manner as in Example 1 except that the obtained optical anisotropic plate 2 was used.
The resulting retardation _{R 0} when light of wavelength 550nm is incident perpendicularly of the optical laminate 2 is 65 nm, retardation _{R 40} when light of wavelength 550nm is incident polar angle 40 degrees, 49 nm met It was. | R ₄₀ −R ₀ | was 16 nm.
Next, the surface of the polarizer P obtained in Production Example 10 in which the absorption axis of the polarizer P and the slow axis of the optical anisotropic plate 2 are perpendicular and the protective film is not laminated is the optical anisotropic plate 2. And laminated with the optical laminated plate 2 so as to be in contact with each other.
Furthermore, the polarizing plate with a low refractive index layer (TAC base material) 2A obtained in Production Example 11 is composed of the slow axis of the triacetyl cellulose film and the absorption axis of the polarizing plate with a low refractive index layer (TAC base material) 2A. The liquid crystal display is laminated with the optical laminated plate 2 so that the surface of the polarizing plate with a low refractive index layer (TAC base material) 2A which is vertical and is not laminated with the low refractive index layer is in contact with the triacetyl cellulose film. Device 4 was made. At this time, the polarizing plate with a low refractive index layer was placed on the observation side of the liquid crystal display device. The evaluation results of the manufactured liquid crystal display device 4 are shown in Table 1.

Example 5 (Production of liquid crystal display device 5)
In the optical laminated plate 2 obtained in Example 4 and the polarizer P obtained in Production Example 10, the absorption axis of the polarizer P and the slow axis of the optical anisotropic plate 2 are perpendicular to each other, and the protective film The layers were stacked so that the surfaces on which the layers were not stacked were in contact with the optical anisotropic plate 2.
Further, the optical laminated plate 2 and the polarizing plate with a low refractive index layer (COP base material) 2C obtained in Production Example 12 were combined with the slow axis of the triacetyl cellulose film and the polarizing plate with a low refractive index layer (COP base material). 2C is laminated so that the absorption axis of 2C is perpendicular and the surface of the polarizing plate with a low refractive index layer (COP base material) 2C on which the low refractive index layer is not laminated is in contact with the triacetylcellulose film. Device 5 was made. At this time, the polarizing plate with a low refractive index layer was placed on the observation side of the liquid crystal display device. The evaluation results of the manufactured liquid crystal display device 5 are shown in Table 1.

(Comparative Example 1) (Production of liquid crystal display device 6)
Instead of the optically anisotropic plates 1a and 1b, a triacetyl cellulose film (n _x = 1.48020, n _y = 1.48014, n _z = 1.479967) having a thickness of 80 μm was used one by one. An optical laminated plate 3 was produced in the same manner as in Example 1.
Retardation _{R 0} when light of wavelength 550nm is incident perpendicularly of the obtained optical laminate 3 is 3 nm, retardation _{R 40} when light of wavelength 550nm is incident polar angle 40 degrees, 41 nm met It was. | _R 40 -R ₀ | was 38nm.
Next, the surface of the optical laminate 2 and the polarizer P obtained in Production Example 13 is such that the absorption axis of the polarizer P and the slow axis of the triacetyl cellulose film are perpendicular and the protective film is not laminated. It laminated | stacked so that a triacetyl cellulose film might be contact | connected.
Further, the optical laminate 2 and the polarizing plate with a low refractive index layer (TAC base material) 2A obtained in Production Example 14 were combined with the slow axis of the triacetyl cellulose film and the polarizing plate with a low refractive index layer (TAC base material). 2A is laminated so that the absorption axis of 2A is perpendicular, and the surface of the polarizing plate with a low refractive index layer (TAC substrate) 2A on which the low refractive index layer is not laminated is in contact with the triacetyl cellulose film, Device 6 was made. At this time, the polarizing plate with a low refractive index layer was placed on the observation side of the liquid crystal display device. The evaluation results of the manufactured liquid crystal display device 6 are shown in Table 1.

(Comparative Example 2) (Production of liquid crystal display device 7)
In Production Example 11, the low refractive index layer-forming composition L3 obtained in Production Example 7 was used in place of the low refractive index layer-forming composition L1, and the low refractive index was produced in the same manner as in Production Example 11. A layered polarizing plate (TAC substrate) 2D was obtained.
Next, the same method as in Example 1 except that this polarizing plate with a low refractive index layer (TAC substrate) 2D was used instead of the polarizing plate with a low refractive index layer (TAC substrate) 2A in Example 1. Thus, a liquid crystal display device 7 was produced. The evaluation results of the obtained liquid crystal display device 7 are shown in Table 1.

(Comparative Example 3) (Production of liquid crystal display device 8)
In Production Example 11, the low refractive index layer-forming composition L4 obtained in Production Example 8 was used in place of the low refractive index layer-forming composition L1, and the low refractive index was produced in the same manner as in Production Example 11. A layered polarizing plate (TAC substrate) 2E was produced.
Next, the same method as in Example 1 except that this polarizing plate with a low refractive index layer (TAC substrate) 2E was used instead of the polarizing plate with a low refractive index layer (TAC substrate) 2A in Example 1. Thus, a liquid crystal display device 8 was produced. The evaluation results of the obtained liquid crystal display device 8 are shown in Table 1.

It is an explanatory view of a measuring method of retardation R _40. It is a block diagram of the one aspect | mode of the liquid crystal display device of this invention. It is a block diagram of the one aspect | mode of the liquid crystal display device of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,11 ... Polarizer, 2,12 ... Optical anisotropic plate, 3,13 ... Liquid crystal cell, 4,14 ... Optical anisotropic plate, 5,15 ... Polarizer, 6,15 ... Antireflection plate

Claims (3)

Between a pair of polarizers composed of an output-side polarizer and an incident-side polarizer whose absorption axes are substantially perpendicular to each other, i (i is an integer of 1 or more) biaxial optics A vertical alignment mode liquid crystal display device having an anisotropic plate and a liquid crystal cell,
Wherein the principal refractive indices n _x in each side of the biaxial optical anisotropic _plate, n y _(provided that n _x> n _y.), When the main refractive index in the thickness direction is n _z,
nx > _ny > _nz
Satisfy the relationship
In the optical laminated plate (O) formed by laminating all the biaxial optical anisotropic plates and the liquid crystal cell, retardation is obtained when light having a wavelength of 550 nm is incident from the normal direction when no voltage is applied. R _0, the retardation when light having a wavelength of 550nm is incident from the direction of the polar angle of 40 degrees when measuring the _{R 40,}
| R ₄₀ -R ₀ | ≦ 35 nm
And satisfy the relationship
An antireflection plate is provided on the observation side of the output side polarizer,
This anti-reflection plate
Hollow particles (A) having a particle size of 5 to 2000 nm,
A siloxane oligomer (B) having a (meth) acryloyl group and a fluoroalkyl group, and
Acrylate compound (C) having (meth) acryloyl group
A liquid crystal display device comprising a low refractive index layer comprising a cured film of a composition comprising: 2. The liquid crystal display device according to claim 1, wherein a refractive index of the low refractive index layer is 1.40 or less. 2. The no-voltage application state, the absorption axis of the exit-side polarizer or the absorption axis of the entrance-side polarizer and the in-plane slow axis of the optical laminated plate (O) are substantially parallel or substantially perpendicular. Or the liquid crystal display device of 2.

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