JP2009186659A - Elliptical polarizing plate, method of manufacturing elliptical polarizing plate, and image display apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an elliptical polarizing plate that is made thin and has satisfactory manufacturing efficiency as the elliptical polarizing plate capable of reducing difficulty of viewing a displayed image caused by the direction of a polarization axis even when a display surface is viewed through an optical member having a polarization action, for example, when the display surface is viewed through a sunglass and to provide an image display apparatus using the same. <P>SOLUTION: In the elliptical polarizing plate, a translucent protective film, an optically anisotropic element composed of a liquid crystal layer, a polarization element and the translucent protective film are layered in this order. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid crystal display panel used for a liquid crystal monitor such as a mobile phone, a portable information device, a camera, and a car navigation system, an image display device including the liquid crystal monitor, an electroluminescence element, and an elliptically polarizing plate used for a touch panel.

Since the liquid crystal display device itself does not emit light, it can be used in various ways to effectively transmit or reflect incident light, regardless of whether it is a transmissive type that illuminates from the back with a backlight or a reflective type that reflects incident light. Improvements have been made. In order to obtain sufficient contrast and achieve good display quality in either the transmissive type or the reflective type, the display modes include TN (twisted nematic) mode, STN (super twisted nematic) mode, ECB (Electrically). In many cases, a mode using a polarizing plate such as a controlled birefringence (IPS) mode, an in-plane switching (IPS) mode, a vertical alignment (VA) mode, or an optically compensated birefringence (OCB) mode is used.
In addition, it is known that a self-luminous electroluminescent element and a resistive pressure-sensitive touch panel are provided with a polarizing plate and a λ / 4 retardation plate in order from the outermost surface side to prevent external light reflection (Patent Document 1 and 2).

In such an image display device using a polarizing plate on the outermost surface, the display light emitted from the polarizing plate on the display side is all linearly polarized light. Therefore, when the image is observed through an optical member having a polarizing action, for example, when the display surface is viewed through sunglasses, the display image may become dark and may not be visible depending on the state. That is, it is a case where it sees at the angle which the polarization axis of display light and the absorption axis of sunglasses correspond.
In order to reduce the degree of difficulty in seeing the display image due to the direction of the polarization axis, a λ / 4 retardation plate is disposed outside the display-side polarizing plate to convert the linearly polarized light into circularly polarized light or A method of emitting as elliptically polarized light has been proposed (Patent Document 3). Most of the λ / 4 retardation plates use polymer films obtained by uniaxial stretching orientation of polycarbonate or the like, and their orientation axes in the long film form are usually limited to the stretching direction, that is, the MD direction. On the other hand, since the polarizing plate also uses a uniaxially stretched film such as polyvinyl alcohol, the absorption axis in the long film form is usually limited to the MD direction. Therefore, when an elliptically polarizing plate is manufactured by continuously laminating a polarizing plate and a retardation film from a long film form, it is limited to a special case where the absorption axis of the polarizing plate and the orientation axis of the retardation film are parallel. It was. In order to make the shaft arrangement other than parallel, it is necessary to cut out and paste the long film into a sheet, and there is a problem that the process is complicated and the productivity is poor. Furthermore, in the stretched and oriented retardation film, it is difficult to freely control the orientation of the polymer, and the degree of freedom in optical properties is limited. As described above, the absorption axis of the polarizing plate and the orientation axis of the retardation film have various axial arrangements, and it has not been possible to sufficiently meet the demand for an elliptically polarizing plate with excellent optical performance.

In order to solve this problem, for example, optical anisotropic elements in which a liquid crystalline polymer is aligned and fixed have been proposed (Patent Documents 4 and 5). Furthermore, a quarter wavelength plate made of a liquid crystal film in which a twisted nematic alignment structure is fixed has been proposed (Patent Documents 6 and 7).
When such a liquid crystalline polymer is used, since the orientation axis angle can be arbitrarily set, various elliptical polarizing plates can be produced by continuously laminating from a long film form, and it is thicker than a stretched film. There was an advantage that can be greatly reduced.
However, the display surface side polarizing plate is generally provided with a hard coat layer, an antireflection layer, an anti-sticking layer, a diffusion layer, an antiglare layer, and the like, and each layer having desired characteristics is directly formed on the liquid crystal layer. It was difficult.
Japanese Patent Laid-Open No. 8-322138 Japanese Patent Laid-Open No. 9-127858 JP 2005-352068 A JP-A-4-57017 JP-A-6-242317 JP 2002-48917 A JP 2004-309904 A

  An object of the present invention is to provide an elliptically polarizing plate that can reduce the degree to which a display image is difficult to see due to the direction of the polarization axis even when viewed through an optical member having a polarizing action, such as when viewing the display surface through sunglasses. An object of the present invention is to provide an elliptically polarizing plate that can be thinned and has good production efficiency, and an image display device using the elliptically polarizing plate.

  That is, the means for solving the above problems are as follows.

[1] An elliptically polarizing plate in which a translucent protective film, an optical anisotropic element made of a liquid crystal layer, a polarizing element, and a translucent protective film are laminated in this order.

[2] The elliptically polarizing plate according to [1], which is obtained from a translucent protective film, an optically anisotropic element, a polarizing element, and a translucent protective film in the form of a long film.

[3] The elliptically polarizing plate as described in [1] or [2] above, wherein the optical anisotropic element is a λ / 4 retardation plate.

[4] An optical anisotropic element made of a liquid crystal layer is laminated between the translucent protective film and the polarizing element on the side opposite to the optical anisotropic element side made of the liquid crystal layer of the polarizing element. The elliptically polarizing plate as described in any one of [1] to [3] above.

[5] The optically anisotropic element includes a nematic alignment or twisted nematic alignment liquid crystal layer in which the alignment is fixed after nematic alignment or twisted nematic alignment in a liquid crystal state. The elliptically polarizing plate as described in any one of [1] to [4] above.

[6] The product of the birefringence Δn and the thickness d (nm) of the liquid crystal layer of the optical anisotropic element with respect to light having a wavelength of 550 nm is set in the range of 100 nm to 300 nm, and the twist angle is 0 ° to 85 °. The elliptically polarizing plate according to any one of the above [1] to [5], which is set in a range of

[7] The elliptically polarizing plate according to any one of [1] to [6], wherein the translucent protective film is a cellulose polymer and / or a cycloolefin polymer.

[8] The elliptically polarizing plate according to any one of [1] to [7], wherein the elliptically polarizing plate has a thickness of 160 μm or less.

[9] At least one layer selected from a hard coat layer, an antireflection layer, an antisticking layer, a diffusion layer and an antiglare layer is formed on the surface of the translucent protective film opposite to the optically anisotropic layer. The elliptically polarizing plate according to any one of [1] to [8], which is provided as described above.

[10] The elliptically polarizing plate according to any one of the above [1] to [9], wherein the alignment direction of the liquid crystal molecules in the vicinity of any one of both surfaces of the liquid crystal layer is not parallel to the MD direction .

[11] An elliptically polarizing plate, wherein the elliptically polarizing plate according to any one of [1] to [10] is further laminated with at least one optical film.

[12] (1) First step of obtaining a laminate (A) composed of an alignment substrate / optically anisotropic element by performing a rubbing treatment on the alignment substrate to form an optically anisotropic element in which the liquid crystal layer is aligned and fixed. ,
(2) After the translucent protective film is adhered to the laminate (A) via the adhesive layer 1, the alignment substrate is peeled off and transferred to the translucent protective film, and the translucent protective film / adhesion Second step of obtaining a layered product (B) composed of the agent layer 1 / optically anisotropic element,
(3) By laminating the laminate (B) comprising the translucent protective film / adhesive layer 1 / optically anisotropic element, the polarizing element, and the translucent protective film via an adhesive, A third step of obtaining an elliptically polarizing plate comprising a translucent protective film / adhesive layer 1 / optically anisotropic element / adhesive layer 2 / polarizing element / adhesive layer 3 / translucent protective film;
The method for producing an elliptically polarizing plate as described in any one of [1] to [11] above, wherein at least each of the steps is performed.

[13] The method for producing an elliptically polarizing plate as described in [12] above, wherein the optically anisotropic element side of the laminate (B) is surface-treated.

[14] The method for producing an elliptically polarizing plate as described in [12] above, wherein the translucent protective film is surface-treated.

[15] The method for producing an elliptically polarizing plate as described in [13] or [14] above, wherein the surface treatment is saponification treatment or corona discharge treatment.

[16] An image display device in which the elliptically polarizing plate according to any one of [1] to [11] is disposed on the display surface side.

[17] A liquid crystal display device in which the elliptically polarizing plate according to any one of [1] to [11] is disposed on the display surface side.

[18] An electroluminescence device in which the elliptically polarizing plate according to any one of [1] to [11] is disposed on the display surface side.

[19] A touch panel in which the elliptically polarizing plate according to any one of [1] to [11] is disposed on the display surface side.

  According to the above configuration, since the emitted display light is circularly polarized light or elliptically polarized light, the display image is hardly visible due to the direction of the polarization axis even when the display surface is viewed through sunglasses. Can be reduced. In addition, it is possible to greatly reduce the thickness by making the optical anisotropic element a liquid crystal layer, and since it can be bonded in the form of a long film, there is an advantage that the bonding process can be streamlined from the conventional method, By disposing the translucent protective film on the outermost surface, a hard coat layer or the like can be easily provided.

  The present invention relates to an elliptically polarizing plate in which a translucent protective film, an optical anisotropic element composed of a liquid crystal layer, a polarizing element, and a translucent protective film are laminated in this order. By using such an elliptically polarizing plate, the number of layers constituting the elliptically polarizing plate is reduced rather than bonding an optically anisotropic element with an adhesive to a polarizing plate protected on both sides of the polarizing element with a translucent protective film. Thinning can be achieved. In addition, an optical anisotropic element is disposed between the translucent protective film and the polarizing element, and the translucent protective film is disposed on the outermost surface, so that hard coat treatment, antireflection treatment, antisticking treatment, antiglare treatment are performed. Etc. can be easily performed. However, it is difficult to bond the optical anisotropic element provided with the liquid crystal layer and the polarizing element. In the present invention, the problem is solved by surface-treating the optical anisotropic element or selecting an appropriate adhesive, and as a whole, the object of the present invention can be effectively achieved. .

Preferred embodiments of the present invention are described in detail below.
The layer structure of the elliptically polarizing plate obtained in the present invention is
(I) It consists of a translucent protective film / adhesive layer 1 / optical anisotropic element / adhesive layer 2 / polarizing element / adhesive layer 3 / translucent protective film.

Furthermore, the following layer configuration in which the optical anisotropic element is laminated between the translucent protective film and the polarizing element on the side opposite to the side where the optical anisotropic element is present with respect to the polarizing element. But you can.
(II) Translucent protective film / adhesive layer 1 / optical anisotropic element / adhesive layer 2 / polarizing element / adhesive layer 2 / optical anisotropic element / adhesive layer 1 / translucent protection the film

  Further, on both sides or one side of the translucent protective film surface, if necessary, one type of translucent overcoat layer member such as a hard coat layer, an antireflection layer, an anti-sticking layer, a diffusion layer, an antiglare layer, or the like Two or more kinds are further added, but in the present invention, an optical anisotropic element comprising a liquid crystal layer in which a nematic or twisted nematic alignment structure is fixed in a liquid crystal state for a compound or composition exhibiting liquid crystallinity is used. There is no particular limitation except for.

Hereafter, the structural member used for this invention is demonstrated in order.
First, the compounds and compositions exhibiting liquid crystal properties used in the present invention will be described.
The liquid crystal layer constituting the optical anisotropic element used in the present invention, for example, cools a compound or composition exhibiting liquid crystallinity aligned on an alignment treatment substrate (alignment substrate) to a glass transition temperature (Tg) or lower. Or by fixing the orientation by appropriately reacting. As the compound or composition exhibiting liquid crystallinity (hereinafter referred to as a liquid crystal composition), those mainly composed of a polymer liquid crystal material exhibiting positive uniaxiality are preferable. As such a polymer liquid crystal substance, a thermotropic liquid crystal polymer exhibiting liquid crystallinity when melted is used. The thermotropic liquid crystal polymer used is required to maintain the molecular alignment state of the liquid crystal phase even when cooled from the molten state (liquid crystal state) to Tg or less.

  The liquid crystal phase at the time of melting of the polymer liquid crystal material may be any molecular alignment structure such as smectic, nematic, twisted nematic, cholesteric, etc., and in a homogeneous alignment and homeotropic alignment state near the alignment substrate and near the air interface, respectively. There may be so-called hybrid alignment in which the average director of the polymer liquid crystal material is inclined from the normal direction of the film, or homeotropic alignment from the vicinity of the alignment substrate to the vicinity of the air interface may be used.

  As the polymer liquid crystal substance, various main chain type polymer liquid crystal substances, side chain type polymer liquid crystal substances, or a mixture thereof can be used. Main chain type polymer liquid crystal substances include polyester, polyamide, polycarbonate, polyimide, polyurethane, polybenzimidazole, polybenzoxazole, polybenzthiazole, polyazomethine, polyesteramide, polyester carbonate Type, polyesterimide type polymer liquid crystal, or a mixture thereof. Among these, semi-aromatic polyester polymer liquid crystals in which mesogenic groups giving liquid crystallinity and bent chains of polymethylene, polyethylene oxide, polysiloxane, etc. are alternately bonded, or wholly aromatic polyester polymers without bent chains Liquid crystals are desirable in the present invention. Further, as the side chain type polymer liquid crystal material, a material having a skeleton chain of a linear or cyclic structure such as polyacrylate, polymethacrylate, polyvinyl, polysiloxane, polyether, polymalonate, polyester, etc. Examples thereof include a polymer liquid crystal having a mesogenic group bonded as a side chain, or a mixture thereof. Among these, there are side-chain polymer liquid crystals in which a mesogenic group that gives liquid crystallinity is bonded to a skeleton chain through a spacer made of a bent chain, and polymer liquid crystals having a molecular structure having mesogens in both the main chain and the side chain. This is desirable in the present invention.

In addition, in order to induce twisted nematic alignment in the liquid crystal layer, a liquid crystal composition in which a chiral agent is added to the liquid crystalline composition or various liquid crystal materials or non-liquid crystal materials having at least one chiral structural unit are blended. It is particularly desirable that it is a composition.
Examples of the chiral structural unit include optically active 2-methyl-1,4-butanediol, 2,4-pentanediol, 1,2-propanediol, 2-chloro-1,4-butanediol, 2- Fluoro-1,4-butanediol, 2-bromo-1,4-butanediol, 2-ethyl-1,4-butanediol, 2-propyl-1,4-butanediol, 3-methylhexanediol, 3- Units derived from methyladipic acid, naproxen derivatives, camphoric acid, binaphthol, menthol or cholesteryl group-containing structural units or derivatives thereof (for example, derivatives such as diacetoxy compounds) can be used. The diols may be either R-form or S-form, and may be a mixture of R-form and S-form. These structural units are merely examples, and the present invention is not limited thereto.

  In addition, even in the case of oligomers and low-molecular liquid crystals, thermal crosslinking, photocrosslinking, etc. in a state where the alignment is fixed by cooling to below the liquid crystal transition temperature or liquid crystal transition temperature by introducing a crosslinkable group or blending of appropriate crosslinking agents. Those that can be polymerized by the above means are also included in the polymer liquid crystal. Even a discotic liquid crystal compound can be used without any problem. As the polymer liquid crystal, those showing optically positive or negative uniaxiality are usually used. Their optical characteristics are appropriately selected depending on the function required for the optical anisotropic element, but in the case of a liquid crystal layer with twisted nematic alignment, a polymer liquid crystal exhibiting positive uniaxiality is preferably used.

  Examples of the low-molecular liquid crystal include Schiff base, biphenyl, terphenyl, ester, thioester, stilbene, tolan, azoxy, azo, phenylcyclohexane, pyrimidine, cyclohexylcyclohexane, trimesic acid , Triphenylene-based, torquesen-based, phthalocyanine-based, low-molecular liquid crystal compounds having a porphyrin-based molecular skeleton, or a mixture of these compounds.

  The Tg of the polymer liquid crystal is preferably room temperature or higher, and more preferably 50 ° C. or higher in order to affect the alignment stability after alignment fixation. Tg can be adjusted by the type of monomer used for the synthesis of the polymer liquid crystal, the monomer ratio, the polymerization conditions, etc., but can also be adjusted by the crosslinking means as described above.

Next, the alignment substrate will be described.
Examples of the alignment substrate include thermosetting resins such as polyimide, epoxy resin, and phenol resin, polyamides such as nylon; polyetherimide; polyetherketone; polyetheretherketone (PEEK); polyketone; polyethersulfone; polyphenylenesulfide; Polyphenylene oxide; Polyester such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate; Polyacetal; Polycarbonate; Poly (meth) acrylate; Polymer film exemplified by thermoplastic resin such as polyvinyl alcohol can be used. Further, on the surface of the polymer film, a thin film made of the above-described other resin or various compounds known as liquid crystal aligning agents, for example, various surfactants, a layer made of a silane compound, a chromium complex or the like is formed. Also good. The polymer film is subjected to an alignment process such as a rubbing process and is provided on an alignment substrate. Furthermore, a metal thin plate such as aluminum or copper surface-treated with the above-mentioned aligning agent or the like can be used as the alignment substrate.

As described above, in order to align the liquid crystalline composition on the alignment substrate, usually a rubbing treatment is often performed.
Hereinafter, the rubbing process in the case of producing an optical anisotropic element in the form of a long film will be described. The rubbing process can be performed at a predetermined arbitrary angle with respect to the MD direction of the long alignment substrate. Although the angle of the rubbing direction with respect to the MD direction is appropriately set according to the function of the optical anisotropic element, it is usually preferable that the rubbing is performed obliquely with respect to the MD direction. The angle in the oblique direction is preferably in the range of −45 degrees to +45 degrees.

  The rubbing treatment can be performed by an arbitrary method. For example, a rubbing roll is arranged at an arbitrary angle with respect to the MD direction of the long film on a stage that conveys the long film in the MD direction. The rubbing roll is rotated while being conveyed in the MD direction to rub the film surface. The angle formed by the rubbing roll and the moving direction of the stage is a mechanism that can be freely adjusted, and an appropriate rubbing cloth material is stuck on the surface of the rubbing roll.

  Next, as a method of forming the liquid crystalline composition layer by bringing the liquid crystalline composition into contact with the rubbing-treated surface of the alignment substrate, for example, a method in which the liquid crystalline composition is dissolved in an appropriate solvent and applied or dried, or And a method of directly melting and extruding the liquid crystalline composition with a T die or the like. From the standpoint of film thickness uniformity, a solution coating and drying method is suitable. The method for applying the liquid crystalline composition solution is not particularly limited, and for example, a die coating method, a slot die coating method, a slide die coating method, a roll coating method, a bar coating method, a dip pulling method, or the like can be employed.

After coating, the solvent is removed by an appropriate drying method to form an unoriented liquid crystalline composition layer. Next, after aligning the liquid crystalline composition layer by heating at a predetermined temperature for a predetermined time, the alignment is fixed by cooling to Tg or less, or by curing by light irradiation and / or heat treatment and fixing. A liquid crystal layer can be formed.
As a method of light irradiation, a light source such as a metal halide lamp, a super high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a xenon lamp, an arc lamp, or a laser having a spectrum in a wavelength region suitable for reacting a liquid crystalline composition. Irradiate light. The dose per square centimeter is usually in the range of 1 to 2000 mJ, preferably 10 to 1000 mJ as the cumulative dose.
The temperature at the time of light irradiation needs to be in a temperature range in which the liquid crystalline composition takes liquid crystal alignment. In order to sufficiently enhance the curing effect, it is preferable to perform light irradiation at a temperature equal to or higher than Tg of the liquid crystalline composition.

  The liquid crystal layer constituting the optically anisotropic element has an optically anisotropic axis and a layer in which a nematic alignment structure aligned in one direction is fixed, or has an optically anisotropic axis and has one surface to the other. It means a layer in which a twisted nematic alignment structure having a structure in which the optical anisotropic axis is twisted across the surface is fixed. Therefore, this optically anisotropic element has characteristics equivalent to those obtained by stacking layers having optical anisotropy in multiple layers so that the optically anisotropic axis is continuously twisted. Similar to a twisted nematic liquid crystal cell, STN (super twisted nematic) liquid crystal cell, etc., it has retardation (= Δnd: value represented by product of birefringence Δn and thickness d) and a twist angle. Further, that the alignment structure is fixed means that the alignment structure is not disturbed and maintained under the condition of using the liquid crystal layer. A similar alignment state can be produced in a liquid crystal cell, but fixing the alignment structure eliminates the need for a substrate such as glass in the liquid crystal cell, and can achieve weight reduction, thinning, improved handling, and the like. The liquid crystal layer is preferably a temperature compensation type in which the retardation changes when the temperature environment changes, and the retardation also returns when the temperature is returned to the original temperature. The thickness of the liquid crystal layer is not particularly limited as long as the function of the optical anisotropic element is exhibited, and is suitably 0.05 μm to 100 μm, preferably 0.1 μm to 30 μm.

The product of the birefringence Δn and the thickness d (nm) and the twist angle of the liquid crystal layer depend on whether the application used is a liquid crystal display device or an electroluminescence element, but a liquid crystal with respect to light having a wavelength of 550 nm. The product of the birefringence Δn and the thickness d (nm) of the layer is preferably 100 nm or more and 300 nm or less, and the twist angle is preferably 0 ° or more and 85 ° or less from the viewpoint of optical characteristics. Furthermore, (1) 100 nm or more and 170 nm Or less and 0 degrees or more and 20 degrees or less, (1) 130 nm or more and 200 nm or less and 20 degrees or more and 40 degrees or less, (2) 150 nm or more and 250 nm or less and 40 degrees or more and 70 degrees or less, (3) 230 nm or more and 300 nm or less and 70 degrees or more. It is particularly preferable that one of the conditions of 85 degrees or less is satisfied. There are two types of twisting directions, but they may be right-handed or left-handed.
When the twist angle is 0 degree, it is particularly preferable to have a product of birefringence Δn corresponding to a λ / 4 retardation plate and a thickness d (nm).

Next, the adhesive layer used in the present invention will be described.
As a material for forming the adhesive layer provided on the liquid crystal layer of the optical anisotropic element, the material has sufficient adhesive force to the liquid crystal layer and the translucent protective film, and does not impair the optical characteristics of the liquid crystal layer. If there is no particular limitation, for example, acrylic resin, methacrylic resin, epoxy resin, ethylene-vinyl acetate copolymer system, rubber system, urethane system, polyvinyl ether system and mixtures thereof, thermosetting type And / or various reactive types such as a photo-curing type and an electron beam-curing type. These adhesive layers also include those having the function of a transparent protective layer (overcoat layer) that protects the liquid crystal layer. A pressure sensitive adhesive can also be used as the adhesive.

  Since the reaction (curing) conditions for the reactive substances vary depending on the components constituting the adhesive, the viscosity, the curing temperature, and the like, the conditions suitable for each may be selected. For example, in the case of the photo-curing type, it is preferable to add various known photoinitiators, and light sources such as metal halide lamps, ultra-high pressure mercury lamps, high-pressure mercury lamps, low-pressure mercury lamps, xenon lamps, arc lamps, lasers, synchrotron radiation sources, etc. The light may be irradiated to cause the reaction. The amount of irradiation per unit area (one square centimeter) is usually in the range of 1 to 2000 mJ, preferably 10 to 1000 mJ as the integrated irradiation amount. However, this is not the case when the absorption region of the photoinitiator and the spectrum of the light source are significantly different, or when the reactive compound itself has the ability to absorb the light source wavelength. In these cases, an appropriate photosensitizer or a method of using a mixture of two or more photoinitiators having different absorption wavelengths can be used. The acceleration voltage in the case of the electron beam curable type is usually 10 kV to 200 kV, preferably 50 kV to 100 kV.

  The thickness of the adhesive varies depending on the components constituting the adhesive as described above, the strength of the adhesive, the use temperature, and the like, but is usually 1 to 50 μm, preferably 2 to 30 μm, and more preferably 3 to 10 μm. Outside this range, the adhesive strength is insufficient, or bleeding from the end is not preferable.

These adhesives can also contain various fine particles and surface modifiers for the purpose of controlling the optical properties or controlling the peelability and erosion properties of the substrate as long as the properties are not impaired.
Examples of the fine particles include fine particles having a refractive index different from that of the compound constituting the adhesive, conductive fine particles for improving antistatic performance without impairing transparency, and fine particles for improving wear resistance. Specifically, fine silica, fine alumina, ITO (Indium Tin Oxide) fine particles, silver fine particles, various synthetic resin fine particles and the like can be mentioned.
The surface modifier is not particularly limited as long as it has good compatibility with the adhesive and does not affect the curability of the adhesive or the optical performance after curing, and is an ionic or nonionic water-soluble interface. Activators, oil-soluble surfactants, polymer surfactants, fluorosurfactants, organometallic surfactants such as silicone, reactive surfactants, and the like can be used. In particular, fluorine-based surfactants such as perfluoroalkyl compounds and perfluoropolyether compounds, and organometallic surfactants such as silicone are particularly desirable because they have a large surface modification effect. The addition amount of the surface modifier is desirably in the range of 0.01 to 10% by mass with respect to the adhesive, more desirably 0.05 to 5% by mass, and further desirably 0.1 to 3% by mass. If the amount added is less than this range, the effect of addition becomes insufficient. On the other hand, if the amount added is too large, there is a risk of adverse effects such as an excessive decrease in adhesive strength. In addition, a surface modifier may be used independently and may use multiple types together as needed.
Furthermore, you may mix | blend various additives, such as antioxidant and a ultraviolet absorber, in the range which does not impair the effect of this invention.
The overcoat layer is more preferably resistant to various surface treatments described later.

Next, the polarizing element used in the present invention will be described.
The polarizing element that can be used in the present invention is not particularly limited, and various types can be used. Examples of polarizing elements include hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, and ethylene / vinyl acetate copolymer partially saponified films, and two colors such as iodine and dichroic dyes. And polyene-based oriented films such as those obtained by adsorbing a functional substance and uniaxially stretched, and polyvinyl chloride dehydrochlorinated products. Among these, those obtained by stretching a polyvinyl alcohol film and adsorbing and orienting a dichroic material (iodine, dye) are preferably used. The thickness of the polarizing element is not particularly limited, but is generally about 5 to 80 μm.

  A polarizing element in which a polyvinyl alcohol film is dyed with iodine and uniaxially stretched can be produced by, for example, dyeing polyvinyl alcohol by immersing it in an aqueous solution of iodine and stretching it 3 to 7 times the original length. If necessary, it can be immersed in an aqueous solution of boric acid or potassium iodide. Further, if necessary, the polyvinyl alcohol film may be immersed in water and washed before dyeing. In addition to washing the polyvinyl alcohol film surface with dirt and anti-blocking agents by washing the polyvinyl alcohol film with water, it also has the effect of preventing unevenness such as uneven coloring by swelling the polyvinyl alcohol film. is there. Stretching may be performed after dyeing with iodine, may be performed while dyeing, or may be dyed with iodine after stretching. The film can be stretched in an aqueous solution of boric acid or potassium iodide or in a water bath.

Next, the translucent protective film used in the present invention will be described.
As the translucent protective film, an optically isotropic substrate is preferable. For example, a triacetyl cellulose film such as Fujitac (product of Fujifilm) or Konicatak (product of Konica), Arton film (product of JSR) or ZEONOR Films, cycloolefin polymers such as ZEONEX film (product of ZEON Corporation), TPX film (product of Mitsui Chemicals), and acrylene film (product of MITSUBISHI RAYON Co., Ltd.) can be mentioned. From the viewpoint of moisture resistance and the like, triacetyl cellulose and cycloolefin polymers are preferable. Generally the thickness of a translucent protective film is 200 micrometers or less, and 1-100 micrometers is preferable. In particular, the thickness is preferably 5 to 50 μm.

As the translucent protective film, a film having a hard coat layer, antireflection treatment, antisticking, diffusion or antiglare treatment on the surface can be used.
The hard coat treatment is applied for the purpose of preventing scratches on the surface of the elliptical polarizing plate. For example, a hard film with an excellent UV curable resin such as acrylic or silicone is used to protect the cured film with excellent hardness and sliding properties. It can be formed by a method of adding to the surface of the film. The antireflection treatment is performed for the purpose of preventing the reflection of external light on the surface of the elliptically polarizing plate, and can be achieved by forming an antireflection film or the like according to the prior art. Further, the anti-sticking treatment is performed for the purpose of preventing adhesion with an adjacent layer.

  Anti-glare treatment is performed for the purpose of preventing external light from being reflected on the surface of the elliptically polarizing plate and obstructing the visibility of the light transmitted through the elliptically polarizing plate. For example, a rough surface by a sandblasting method or an embossing method. It can be formed by imparting a fine concavo-convex structure to the surface of the protective film by an appropriate method such as a conversion method or a blending method of transparent fine particles. The fine particles to be included in the formation of the surface fine concavo-convex structure are, for example, conductive materials made of silica, alumina, titania, zirconia, tin oxide, indium oxide, cadmium oxide, antimony oxide or the like having an average particle size of 0.5 to 50 μm. In some cases, transparent fine particles such as inorganic fine particles, organic fine particles composed of a crosslinked or uncrosslinked polymer, and the like are used. When forming a surface fine uneven structure, the amount of fine particles used is generally about 2 to 50 parts by weight, preferably 5 to 25 parts by weight, based on 100 parts by weight of the transparent resin forming the surface fine uneven structure. The antiglare layer may also serve as a diffusion layer (viewing angle expanding function or the like) for diffusing the light transmitted through the polarizing plate to expand the viewing angle.

  The antireflection layer, the antisticking layer, the diffusion layer, the antiglare layer, and the like can be provided on the translucent protective film itself, and separately provided as a separate optical layer from the translucent protective film layer. You can also.

Next, the manufacturing method of the elliptically polarizing plate of this invention is demonstrated in detail.
The layer structure of the elliptically polarizing plate obtained by the present invention has the following structure as shown in FIGS.
(I) Translucent protective film / adhesive layer 1 / optical anisotropic element / adhesive layer 2 / polarizing element / adhesive layer 3 / translucent protective film (II) translucent protective film / Adhesive layer 1 / optical anisotropic element / adhesive layer 2 / polarizing element / adhesive layer 2 / optical anisotropic element / adhesive layer 1 / translucent protective film

Although it does not specifically limit as a manufacturing method of an elliptically polarizing plate, It can manufacture with the following method as an example.
First, the manufacturing method of structure (I) is demonstrated.
Configuration (I) is
(1) A first step of performing a rubbing treatment on an alignment substrate to form an optical anisotropic element in which a liquid crystal layer is aligned and fixed to obtain a laminate (A) composed of the alignment substrate / optical anisotropic element;
(2) After the translucent protective film is adhered to the laminate (A) via the adhesive layer 1, the alignment substrate is peeled off and transferred to the translucent protective film, and the translucent protective film / adhesion Second step of obtaining a layered product (B) composed of the agent layer 1 / optically anisotropic element,
(3) By laminating the laminate (B) comprising the translucent protective film / adhesive layer 1 / optically anisotropic element, the polarizing element, and the translucent protective film via an adhesive, A third step of obtaining an elliptically polarizing plate comprising a translucent protective film / adhesive layer 1 / optically anisotropic element / adhesive layer 2 / polarizing element / adhesive layer 3 / translucent protective film;
It is characterized by passing through each process of at least.

Hereinafter, the manufacturing method from the 1st process to the 3rd process is explained in order.
First, the manufacturing method of the laminated body (A) which is a 1st process is demonstrated.
After rubbing the substrate with a cloth, etc., form a coating film of the liquid crystalline composition by an appropriate method, remove the solvent etc. if necessary, complete the alignment of the liquid crystal by heating, etc. The orientation of the liquid crystal composition layer is fixed by means suitable for the liquid crystal composition. Thus, it is possible to obtain a laminate (A) composed of an optical anisotropic element in which the liquid crystal alignment is fixed on the alignment substrate.

Subsequently, the manufacturing method of the laminated body (B) which is a 2nd process is demonstrated.
On the optically anisotropic element of the laminate (A) produced above, the adhesive layer 1 is formed, and the light-transmitting protective film and the laminate (A) are in close contact with each other via the adhesive layer 1, and then if necessary. After reacting (curing) the adhesive layer, the alignment substrate is peeled off, and the optical anisotropic element is transferred to the translucent protective film, whereby the laminate (B) can be obtained.

Next, the manufacturing method in the third step will be described.
The optically anisotropic element side of the laminate (B) is closely attached to one side of the polarizing element via the adhesive layer 2, and the other side is transparent via the adhesive layer 3. After adhering the light protective film, an elliptically polarizing plate can be obtained by reacting (curing) the adhesive layer as necessary.

Next, the manufacturing method of structure (II) is demonstrated.
Configuration (II) is
(1) A first step of performing a rubbing treatment on an alignment substrate to form an optical anisotropic element in which a liquid crystal layer is aligned and fixed to obtain a laminate (A) composed of the alignment substrate / optical anisotropic element;
(2) After the translucent protective film is adhered to the laminate (A) via the adhesive layer 1, the alignment substrate is peeled off and transferred to the translucent protective film, and the translucent protective film / adhesion Second step of obtaining a layered product (B) composed of the agent layer 1 / optically anisotropic element,
(3) The laminate (B) composed of a translucent protective film / adhesive layer 1 / optically anisotropic element, and the laminate composed of a polarizing element, an optically anisotropic element / adhesive layer 1 / translucent protective film. By adhering (B) via an adhesive, a translucent protective film / adhesive layer 1 / optical anisotropic element / adhesive layer 2 / polarizing element / adhesive layer 2 / third step of obtaining an elliptically polarizing plate comprising an optically anisotropic element / adhesive layer 1 / translucent protective film;
It is characterized by passing through each process of at least.

Hereinafter, the manufacturing method from the 1st process to the 3rd process is explained in order.
About the manufacturing method of the laminated body (A) which is the 1st process, and the manufacturing method of the laminated body (B) which is the 2nd process, it is the same as that of the 1st process of composition (I), and the 2nd process.
Next, the manufacturing method in the third step will be described.
After the optical element of the laminate (B) is closely attached to both sides of the polarizing element via the adhesive layer 2, the adhesive layer is reacted (cured) as necessary to react with the elliptical polarizing plate. Can be obtained.
The two optical anisotropic elements in the configuration (II) may have the same parameter or different parameters.

The optically anisotropic element is bonded to the polarizing element, but it is preferable to subject the translucent protective film, the polarizing element, and the optically anisotropic element to surface treatment before bonding.
For the surface treatment, a method suitable for each element or film may be used. Examples of such a method include saponification treatment, corona discharge treatment, flame treatment, etc. More preferably, for example, when triacetylcellulose is used. When saponification treatment is used, and when a cycloolefin polymer is used, corona discharge treatment is preferable.

  The saponification treatment is usually performed by contacting with an alkaline aqueous solution. As the alkaline aqueous solution, potassium hydroxide, sodium hydroxide or the like is used, and the alkali concentration is 0.1 to 10% by mass, preferably 0.5 to 5% by mass, more preferably about 1 to 3% by mass. A dilute solution is sufficient. As treatment conditions, mild conditions of 1 to 60 minutes at room temperature, preferably 30 minutes or less, more preferably 15 minutes or less are sufficient. Needless to say, it is necessary to thoroughly wash with water after the treatment. If the overcoat layer is provided on the liquid crystal layer, the liquid crystal layer will not be eroded or damaged in the saponification treatment step.

Similar to the above saponification treatment, the corona discharge treatment may be carried out under ordinary conditions, for example, on the surface of the translucent protective film in contact with the adhesive layer. The processing conditions vary depending on the type of substrate and corona processing apparatus to be used. For example, the energy density is preferably 1 to 300 W · min / m ² . The surface tension is increased by performing the corona discharge treatment, but it is desirable to increase the surface tension to 40 dyn / cm or more.

  Bonding of the optical anisotropic element and the polarizing element can be performed using an appropriate pressure-sensitive adhesive or adhesive (referred to as an adhesive in the present specification). Any adhesive can be used as long as it is translucent and optically isotropic, and examples thereof include acrylic, epoxy, ethylene-vinyl acetate, and rubber. May have a reactive group such as a photopolymerizable group, in which case it is necessary to perform a curing step suitable for reacting the reactive group after bonding. Among the above adhesives, acrylic adhesives are particularly preferably used.

The adhesive may be performed in the same manner as the formation of the liquid crystal layer, or a so-called non-carrier adhesive in which the adhesive layer is formed on a suitable substrate provided with an easy release treatment such as silicone. An adhesive may be used. The thickness of the adhesive layer may be in the same range as the above-mentioned adhesive.
Also, pressurization using a laminator, roll, pressurizer, etc. to improve the strength of bonding between the optically anisotropic element and the polarizing element, to prevent the generation of bubbles due to residual air at the bonding interface, etc. Heating or the like may be added.

Said optically anisotropic element, polarizing element, and translucent protective film can be laminated | stacked by superimposing continuously in the state aligned in MD direction in the form of a long film, respectively.
Further, in addition to the manufacturing method, these three members can apply an optical anisotropic element and a light-transmitting protection to the polarizing element even if the optical anisotropic element and the light-transmitting protective film are simultaneously bonded to both sides of the polarizing element. You may bond in order of a film.
The elliptically polarizing plate of the present invention thus obtained has a thickness of 160 μm or less, but is preferably 150 μm or less, more preferably 140 μm or less, from the demand for thinning of the image display device or the electroluminescence element.

  The optical film used in combination with the elliptically polarizing plate of the present invention is not particularly limited as long as it has a phase difference and is excellent in transparency and uniformity, and an optical compensation film made of a polymer stretched film or liquid crystal. Preferable examples can be given. Examples of the stretched polymer film include uniaxial or biaxial retardation films made of cellulose, polycarbonate, polyarylate, polysulfone, polyacryl, polyether sulfone, cycloolefin polymer, and the like. it can. Of these, polycarbonate is preferred from the viewpoint of cost and film uniformity.

  In addition, the optical compensation film made of liquid crystal is not particularly limited as long as it is a film that can utilize the optical anisotropy generated from the alignment state by aligning the liquid crystal. For example, known materials such as various optical functional films using nematic liquid crystal, discotic liquid crystal, smectic liquid crystal and the like can be used.

The optical film illustrated here may be used alone or in plural. Further, both a polymer stretched film and an optical compensation film made of liquid crystal can be used.
The product (retardation value) of birefringence Δn and thickness d (nm) of these optical films is the retardation value of the optical anisotropic element used in the present invention and the retardation of the liquid crystal cell constituting the image display device to be incorporated. Since it varies depending on the value, it cannot be generally determined, but it is usually 50 to 2000 nm, preferably 80 to 1000 nm.

Next, the image display device of the present invention will be described.
First, a liquid crystal display device to which the elliptically polarizing plate of the present invention is applied will be described.
A liquid crystal display device is generally composed of a polarizing plate, a liquid crystal cell, and a member such as a retardation compensation plate, a reflection layer, a light diffusion layer, a backlight, a front light, a light control film, a light guide plate, and a prism sheet as necessary. Although it comprises, in this invention, there is no restriction | limiting in particular except the point which uses the elliptically polarizing plate of this invention for at least 1 sheet of a polarizing plate.

The polarizing plate used for the liquid crystal display device is not particularly limited, and those obtained from the same polarizing element as those used for the elliptically polarizing plate described above can be used.
The liquid crystal cell is not particularly limited, and a general liquid crystal cell such as a liquid crystal layer sandwiched between a pair of transparent substrates provided with electrodes can be used.
The transparent substrate constituting the liquid crystal cell is not particularly limited as long as the liquid crystal material constituting the liquid crystal layer is aligned in a specific alignment direction. Specifically, a transparent substrate in which the substrate itself has a property of orienting liquid crystals, a transparent substrate in which an alignment film having the property of orienting liquid crystals is provided, but the substrate itself lacks the alignment ability. Either can be used. Moreover, a well-known thing can be used for the electrode of a liquid crystal cell. Usually, it can be provided on the surface of the transparent substrate in contact with the liquid crystal layer, and when a substrate having an alignment film is used, it can be provided between the substrate and the alignment film.

  The material exhibiting liquid crystallinity for forming the liquid crystal layer is not particularly limited, and examples thereof include various ordinary low-molecular liquid crystal substances, polymer liquid crystal substances, and mixtures thereof that can constitute various liquid crystal cells. In addition, a dye, a chiral agent, a non-liquid crystal substance, or the like can be added to these as long as liquid crystallinity is not impaired.

In addition to the electrode substrate and the liquid crystal layer, the liquid crystal cell may include various components necessary for forming various types of liquid crystal cells described later.
As the liquid crystal cell system, TN (Twisted Nematic) system, STN (Super Twisted Nematic) system, ECB (Electrically Controlled Birefringence) system, IPS (In-Plane Switching) system, VA (Vertical Alignment) system, OCB (Optically Compensated Birefringence (HAN) (Hybrid Aligned Nematic), ASM (Axially Symmetric Aligned Microcell), halftone gray scale, domain division, ferroelectric liquid crystal, display system using antiferroelectric liquid crystal, etc. There are various methods.

  Also, the liquid crystal cell driving method is not particularly limited, and a passive matrix method used for STN-LCDs, etc., and an active matrix method using active electrodes such as TFT (Thin Film Transistor) electrodes and TFD (Thin Film Diode) electrodes, Any driving method such as a plasma addressing method may be used.

  In the elliptically polarizing plate of the present invention disposed in these liquid crystal display devices, at least one of the disposed polarizing plates may be the elliptically polarizing plate of the present invention. It is more preferable to arrange in place of the plate.

  The retardation compensation plate used in the liquid crystal display device is not particularly limited as long as it has excellent transparency and uniformity, but a polymer stretched film or an optical compensation film made of liquid crystal can be preferably used. Examples of the stretched polymer film include uniaxial or biaxial retardation films made of cellulose, polycarbonate, polyarylate, polysulfone, polyacryl, polyether sulfone, cycloolefin polymer, and the like. it can. Of these, polycarbonate is preferred from the viewpoint of cost and film uniformity.

In addition, the optical compensation film made of liquid crystal is not particularly limited as long as it is a film that can utilize the optical anisotropy generated from the alignment state by aligning the liquid crystal. For example, known materials such as various optical functional films using nematic liquid crystal, discotic liquid crystal, smectic liquid crystal and the like can be used.
The phase difference compensator exemplified here may be used alone or in a plurality of sheets when constituting a liquid crystal display device. Further, both a polymer stretched film and an optical compensation film made of liquid crystal can be used.

  The reflective layer is not particularly limited, and is a metal such as aluminum, silver, gold, chromium, or platinum, an alloy containing them, an oxide such as magnesium oxide, a dielectric multilayer film, a liquid crystal exhibiting selective reflection, or these. The combination of these can be illustrated. These reflective layers may be flat or curved. In addition, the reflective layer is processed to have a surface shape such as a concavo-convex shape so as to have diffuse reflectivity, the liquid crystal cell is combined with an electrode on the electrode substrate opposite to the observer side, and the thickness of the reflective layer It may be a semi-transmissive reflective layer in which light is partially transmitted by thinning or forming a hole or the like, or a combination thereof.

  The light diffusion layer is not particularly limited as long as it has a property of diffusing incident light isotropically or anisotropically. For example, it may be composed of two or more regions, with a difference in refractive index between the regions, or with surface irregularities. Examples of the two or more regions having a refractive index difference between the regions include those in which particles having a refractive index different from that of the matrix are dispersed in the matrix. The diffusion layer itself may have an adhesive property.

The film thickness of the light diffusing layer is not particularly limited, but is usually preferably 10 μm or more and 500 μm or less.
Further, the total light transmittance of the light diffusion layer is preferably 50% or more, and particularly preferably 70% or more. Further, the haze value of the light diffusion layer is usually 10 to 95%, preferably 40 to 90%, and more preferably 60 to 90%.

  The backlight, front light, light control film, light guide plate, and prism sheet are not particularly limited, and known ones can be used.

  The liquid crystal display device of the present invention can be provided with other constituent members in addition to the constituent members described above. For example, by attaching a color filter to the liquid crystal display device of the present invention, a color liquid crystal display device capable of performing multicolor or full color display with high color purity can be manufactured.

Next, an organic electroluminescence element (organic EL display device) to which the elliptically polarizing plate of the present invention is applied will be described.
Generally, in an organic EL display device, a transparent electrode, an organic light emitting layer, and a metal electrode are sequentially laminated on a transparent substrate to form a light emitter (organic electroluminescent light emitter). Here, the organic light emitting layer is a laminate of various organic thin films, for example, a laminate of a hole injection layer made of a triphenylamine derivative and the like and a light emitting layer made of a fluorescent organic solid such as anthracene, Alternatively, a structure having various combinations such as a laminate of such a light emitting layer and an electron injection layer composed of a perylene derivative or the like, or a laminate of these hole injection layer, light emitting layer, and electron injection layer is known. It has been. As described above, in order to prevent reflection of external light, a circularly polarizing plate including a polarizing plate and a λ / 4 retardation plate is disposed on the viewer side (front side) of the organic EL display device as viewed from the viewer. However, when the elliptically polarizing plate of the present invention is applied to an organic EL display device, the elliptically polarizing plate of the present invention (translucent protective film / optically anisotropic element comprising a liquid crystal layer having a λ / 4 phase difference / polarized light). The element / translucent protective film) may be directly bonded to the λ / 4 retardation plate via an adhesive and placed on the observer side of the organic EL display device.

Next, a touch panel to which the elliptically polarizing plate of the present invention is applied will be described.
Generally, a touch panel has a structure in which a conductive layer is formed on glass or a film and the conductive layers formed on the film are arranged to face each other via a spacer, that is, for example, display / glass or film / conductive layer A / (spacer. ) / Conductive layer B / Film / Hard coat layer, etc. If the finger is pressed directly from the hard coat side with a pen, the film is curved only at that portion, and the conductive layer B is opposed to the hard coat side conductive layer B An input can be made by touching A, and the pressed position is recognized as an XY coordinate and input to a computer or the like. Therefore, it is used for applications such as car navigation, PDA (personal digital assistant), home appliances, and displays.

  When the elliptically polarizing plate of the present invention is applied to a touch panel, it may be the same as that applied to an organic EL display device, and comprises a polarizing plate and a λ / 4 retardation plate arranged to prevent reflection of external light. Instead of the circularly polarizing plate, the elliptically polarizing plate of the present invention (translucent protective film / optically anisotropic element comprising a liquid crystal layer having a λ / 4 phase difference / polarizing element / translucent protective film) is directly used. What is necessary is just to stick together to 4 phase difference plates through an adhesive agent, and to arrange | position to the observer side of a touch panel.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. The retardation Δnd in this example is a value at a wavelength of 550 nm unless otherwise specified.
In addition, each analysis method used in the Example is as follows.
(1) Measurement of logarithmic viscosity
Using an Ubbelohde viscometer, measurement was performed at 30 ° C. in a mixed solvent of phenol / tetrachloroethane (60/40 mass ratio).
(2) Microscope observation The alignment state of the liquid crystal was observed with an Olympus BH2 polarizing microscope.
(3) Ellipsometry measurement An ellipsometer (DVA-36VWLD) manufactured by Mizoji Optical Corporation was used.
(4) Film thickness measurement method SURFACE TEXTURE ANALYSIS SYSTEM Dektak 3030ST made by SLOAN was used. Moreover, the method of calculating | requiring a film thickness from the data of interference wave measurement (The JASCO Corporation UV / visible / near infrared spectrophotometer V-570) and refractive index data was used together.

<Example 1>
(Preparation of liquid crystalline composition solution B, optically anisotropic element C and laminate A)
Polymerization was carried out at 270 ° C. for 12 hours in a nitrogen atmosphere using 50 mmol of terephthalic acid, 50 mmol of 2,6-naphthalenedicarboxylic acid, 40 mmol of methylhydroquinone diacetate, 60 mmol of catechol diacetate, and 60 mg of N-methylimidazole. The obtained reaction product was dissolved in tetrachloroethane and then purified by reprecipitation with methanol to obtain 14.7 g of a liquid crystalline polyester (polymer 1). This liquid crystalline polyester (Polymer 1) had a logarithmic viscosity of 0.17, a nematic phase as a liquid crystal phase, an isotropic phase-liquid crystal phase transition temperature of 250 ° C. or higher, and a glass transition point of 115 ° C.
Also, 90 mmol of biphenyl dicarbonyl chloride, 10 mmol of terephthaloyl chloride, and 105 mmol of S-2-methyl-1,4-butanediol are reacted in dichloromethane at room temperature for 20 hours, and the reaction solution is poured into methanol for reprecipitation. As a result, 12.0 g of liquid crystalline polyester (polymer 2) was obtained. The logarithmic viscosity of this liquid crystalline polyester (Polymer 2) was 0.12.
Next, a liquid crystal composition solution B was prepared by dissolving a mixed polymer composed of 19.82 g of polymer 1 and 0.18 g of polymer 2 in N-methylpyrrolidone so as to be 20% by mass.
While conveying a long PEEK film having a width of 650 mm and a thickness of 100 μm, a rubbing roll of 150 mmφ wound with a rayon cloth was continuously rubbed at high speed to obtain an oriented substrate film having a rubbing angle of 0 °. . Here, the rubbing angle is an angle in the counterclockwise direction from the MD direction when the rubbing surface is viewed from above.
The liquid crystalline composition solution B is continuously applied and dried on the oriented substrate film using a die coater to form an unoriented liquid crystalline composition layer, and then heat-treated at 150 ° C. for 10 minutes. Then, the liquid crystalline composition was aligned, and then cooled to room temperature to fix the alignment, thereby obtaining a laminate A of the optical anisotropic element C composed of a liquid crystal layer and a PEEK film. This liquid crystal layer had a twisted nematic orientation, a twist angle of −65 degrees, and Δnd of 190 nm.

(Preparation of laminated body B)
A commercially available UV curable adhesive (UV-3400, manufactured by Toagosei Co., Ltd.) was applied on the optically anisotropic element C of the laminate A as an adhesive layer 1 to a thickness of 5 μm, and a TAC film ( 40 μm, manufactured by Fuji Film Co., Ltd.) was laminated, and the adhesive layer 1 was cured by UV irradiation of about 600 mJ. Thereafter, the PEEK film is peeled off from the laminate in which the PEEK film / optically anisotropic element C / adhesive layer 1 / TAC film is integrated to transfer the optically anisotropic element C onto the TAC film, and the TAC film / A laminate B composed of adhesive layer 1 / optically anisotropic element C was obtained.

(Preparation of elliptically polarizing plate D)
A TAC film (40 μm, manufactured by Fuji Film Co., Ltd.) was immersed in a 2% by mass aqueous potassium hydroxide solution at room temperature for 5 minutes for saponification treatment, washed in running water, and dried. A saponified TAC film was continuously bonded to one surface of a polarizing element in which iodine was adsorbed to stretched polyvinyl alcohol using an acrylic adhesive. Further, the other surface of the polarizing element is subjected to corona treatment on the surface of the laminated body B on the optical anisotropic element C side under the condition of 250 W · min / m ² , and the corona treatment surface within 30 seconds after the corona treatment. An elliptically polarizing plate D as shown in FIG. 1 was produced by pasting together (on the optical anisotropic element C side). The total film thickness was about 130 μm and could be made thinner than usual. When this ellipse polarizing plate D was subjected to polarization analysis using an ellipsometer (DVA-36VWLD manufactured by Mizoji Optical Co., Ltd.), the ellipticity at a wavelength of 550 nm was 0.94, and it was an elliptically polarizing plate having good circular polarization characteristics. It was confirmed that there was.
When this elliptically polarizing plate D was optically inspected, no damage such as spots or scratches was found on the optical anisotropic element layer.
It has been found that providing a hard coat layer, an antireflection layer, an antisticking layer, a diffusion layer, an antiglare layer, and the like on the TAC film to be the outermost surface layer can be easily formed by existing techniques.

(Visibility on LCD)
For the commercially available IPS type liquid crystal television arranged in the order of the backlight, the lower polarizing plate, the IPS type liquid crystal cell, and the upper polarizing plate, as shown in FIG. The polarizing plate D was disposed so that the optical anisotropic element C was on the outside. As a result, it was found that even when the display surface was viewed through polarized sunglasses, the display image did not become dark and a good image could be confirmed.

<Example 2>
(Preparation of liquid crystalline composition solution E, optical anisotropic element F, and laminate G)
A liquid crystal composition solution E was prepared by dissolving in N-methylpyrrolidone so that the polymer 1 produced in Example 1 was 20% by mass. While conveying a long PEEK film with a width of 650 mm and a thickness of 100 μm, a 150 mmφ rubbing roll wrapped with a rayon cloth is set obliquely and rotated at a high speed for continuous rubbing, with a rubbing angle of 45 °. A substrate film was obtained. Here, the rubbing angle is an angle in the counterclockwise direction from the MD direction when the rubbing surface is viewed from above. The liquid crystalline composition solution E was continuously applied and dried on the oriented substrate film using a die coater to form an unoriented liquid crystalline composition layer, and then heat-treated at 150 ° C. for 10 minutes. Then, the liquid crystalline composition was aligned, then cooled to room temperature to fix the alignment, and a laminate G of the optically anisotropic element F composed of a liquid crystal layer and a PEEK film was obtained. This liquid crystal layer was nematically oriented, the twist angle was 0 degree, and Δnd was 140 nm.

(Preparation of laminated body H)
A commercially available UV curable adhesive (UV-3400, manufactured by Toagosei Co., Ltd.) was applied on the optically anisotropic element F of the laminate G as an adhesive layer 1 to a thickness of 5 μm, and a ZEONOR film ( A film thickness of 40 μm, manufactured by Nippon Zeon Co., Ltd.) was laminated, and the adhesive layer 1 was cured by UV irradiation of about 600 mJ. Thereafter, the PEEK film is peeled off from the laminate in which the PEEK film / optically anisotropic element F / adhesive layer 1 / Zeonor film is integrated to transfer the optically anisotropic element F onto the Zeonor film, and the Zeonor film / A laminate H composed of adhesive layer 1 / optically anisotropic element F was obtained.

(Preparation of adhesive)
As urethane-based adhesive, 100 parts of "EL-436A" (aqueous solution with a solid content of 35%) manufactured by Toyo Morton Co., Ltd., which is a polyester polyol prepolymer as the main agent, is used as Toyo Morton Co., Ltd., an isocyanate curing agent. 30 parts of “EL-436B” (100% active ingredient product) manufactured by the same method, and water was further added to dilute the solid content concentration to 20%. On the other hand, as a polyvinyl alcohol-based adhesive, a carboxyl group-modified polyvinyl alcohol “Kuraray Poval KL318” manufactured by Kuraray Co., Ltd. (a saponification product of a copolymer having a molar ratio of vinyl acetate and sodium itaconate of about 98: 2, saponification degree) A 3% aqueous solution having a molecular weight of about 85,000 was prepared. The obtained urethane adhesive and polyvinyl alcohol aqueous solution were mixed at a mass ratio of 1: 1 (20: 3 in terms of solid content mass ratio) to obtain a mixed adhesive.

(Preparation of elliptically polarizing plate I)
The mixed adhesive prepared as an adhesive layer was applied to both surfaces of the polarizing element in which iodine was adsorbed to stretched polyvinyl alcohol within 1 minute after mixing, and the optically anisotropic element F side of the laminate H was coated. The surface was subjected to corona treatment under the condition of 250 W · min / m ² , and the corona treatment surface (optical anisotropic element F side) was bonded to produce an elliptically polarizing plate I as shown in FIG. The total film thickness was about 140 μm, which was thinner than usual. When this ellipse polarizing plate I was subjected to ellipsometry with an ellipsometer (DVA-36VWLD, manufactured by Mizoji Optical Co., Ltd.), the ellipticity at a wavelength of 550 nm was 0.96, and it was confirmed that it had good circular polarization characteristics. It was. When this elliptically polarizing plate I was optically inspected, no damage such as spots or scratches was found on the liquid crystal layer.

(Visibility on organic EL display)
For the commercially available organic EL display arranged in the order of the organic EL element, the λ / 4 film, and the polarizing plate, the elliptically polarizing plate I produced above is arranged instead of the λ / 4 film and the polarizing plate, and FIG. An organic EL display as shown was produced. As a result, it was found that even when the display surface was viewed through polarized sunglasses, the display image did not become dark and a good image could be confirmed.

(Visibility on LCD with touch panel)
For the commercially available liquid crystal display device with a touch panel arranged in the order of backlight, liquid crystal display device, touch panel, λ / 4 film, and upper polarizing plate, the elliptically polarized light produced above instead of λ / 4 film and upper polarizing plate A liquid crystal display device with a touch panel as shown in FIG. As a result, it was found that even when the display surface was viewed through polarized sunglasses, the display image did not become dark and a good image could be confirmed.

<Comparative Example 1>
A commercially available polarizing plate (TAC film / polarizing element / TAC film: SRW062 manufactured by Sumitomo Chemical Co., Ltd.), a λ / 4 film (Δnd 140 nm) made of a polycarbonate film has an absorption axis of the polarizing plate and a slow axis of the polycarbonate film is 45. They were pasted together so that it was right. Similar to Example 1 and Example 2, by disposing on the outermost surface of the liquid crystal display, organic EL display, or touch panel, image degradation due to polarized sunglasses disappeared, but the total film thickness became about 170 μm, and the thickness was thin. It turned out that it is inferior in terms of conversion.
Hard coat layer, antireflection layer, antisticking layer, diffusion layer, antiglare layer, etc. on the outermost polycarbonate film are difficult to apply. Was found to be thicker.

<Comparative Example 2>
An elliptically polarizing plate J was produced in the same manner as in Example 1 except that the laminate B produced in Example 1 was bonded to the polarizing element on the TAC film side opposite to the optical anisotropic element C side. The total film thickness was about 130 μm.
Similar to Example 1 and Example 2, by disposing the liquid crystal display, the organic EL display, and the touch panel on the outermost surface, the image degradation due to the polarized sunglasses disappeared, but the optical anisotropic element C on the outermost surface was removed. It is difficult to provide a hard coat layer, an antireflection layer, an anti-sticking layer, a diffusion layer, an antiglare layer, etc., and it is understood that the total film thickness becomes thick because a film having a surface treatment layer is bonded separately. Moreover, it turned out that a manufacturing process also becomes complicated.

1 is an elevational sectional view schematically showing an elliptically polarizing plate (I) of the present invention. It is a three-dimensional cross-sectional view schematically showing the elliptically polarizing plate (II) of the present invention. 1 is a conceptual diagram of a liquid crystal display used in Example 1. FIG. 6 is a conceptual diagram of an organic EL display used in Example 2. FIG. It is a conceptual diagram of the liquid crystal display device with a touch panel used in Example 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Elliptical polarizing plate 2 Translucent protective film 3 Adhesive layer 1
4 Optical anisotropic element 5 Adhesive layer 2
6 Polarizing element 7 Adhesive layer 3
8 translucent protective film 9 IPS type liquid crystal cell 10 lower polarizing plate 11 backlight 12 elliptical polarizing plate 13 transparent glass substrate 14 anode 15 light emitting layer 16 cathode 17 organic EL element 18 touch panel 19 liquid crystal display device

Claims (19)

  An elliptically polarizing plate in which a translucent protective film, an optical anisotropic element made of a liquid crystal layer, a polarizing element, and a translucent protective film are laminated in this order.   The elliptically polarizing plate according to claim 1, wherein the elliptically polarizing plate is obtained from a translucent protective film, an optical anisotropic element, a polarizing element, and a translucent protective film in the form of a long film.   The elliptically polarizing plate according to claim 1 or 2, wherein the optically anisotropic element is a λ / 4 retardation plate.   An optical anisotropic element made of a liquid crystal layer is laminated between the light-transmitting protective film and the polarizing element on the side opposite to the optical anisotropic element side made of the liquid crystal layer of the polarizing element. The elliptically polarizing plate according to any one of claims 1 to 3.   The optically anisotropic element includes a nematic alignment or twisted nematic alignment liquid crystal layer in which the alignment is fixed after nematic alignment or twisted nematic alignment in a liquid crystal state of a liquid crystalline composition exhibiting at least positive uniaxiality. The elliptically polarizing plate according to any one of claims 1 to 4.   The product of the birefringence Δn and the thickness d (nm) of the liquid crystal layer of the optical anisotropic element with respect to light having a wavelength of 550 nm is set in the range of 100 nm to 300 nm and the twist angle is in the range of 0 ° to 85 °. The elliptically polarizing plate according to claim 1, wherein the elliptically polarizing plate is set.   The translucent protective film is a cellulose polymer and / or a cycloolefin polymer, and the elliptically polarizing plate according to any one of claims 1 to 6.   The elliptically polarizing plate according to claim 1, wherein the elliptically polarizing plate has a thickness of 160 μm or less.   At least one layer selected from a hard coat layer, an antireflection layer, an antisticking layer, a diffusion layer and an antiglare layer is provided on the surface of the translucent protective film opposite to the optically anisotropic layer. The elliptically polarizing plate according to claim 1, wherein the elliptically polarizing plate is provided.   The elliptically polarizing plate according to any one of claims 1 to 9, wherein the alignment direction of liquid crystal molecules in the vicinity of either one of both surfaces of the liquid crystal layer is not parallel to the MD direction.   An elliptically polarizing plate, wherein at least one optical film is further laminated on the elliptically polarizing plate according to claim 1. (1) A first step of performing a rubbing treatment on an alignment substrate to form an optical anisotropic element in which a liquid crystal layer is aligned and fixed to obtain a laminate (A) composed of the alignment substrate / optical anisotropic element;
(2) After the translucent protective film is adhered to the laminate (A) via the adhesive layer 1, the alignment substrate is peeled off and transferred to the translucent protective film, and the translucent protective film / adhesion Second step of obtaining a layered product (B) composed of the agent layer 1 / optically anisotropic element,
(3) By laminating the laminate (B) comprising the translucent protective film / adhesive layer 1 / optically anisotropic element, the polarizing element, and the translucent protective film via an adhesive, A third step of obtaining an elliptically polarizing plate comprising a translucent protective film / adhesive layer 1 / optically anisotropic element / adhesive layer 2 / polarizing element / adhesive layer 3 / translucent protective film;
The method for producing an elliptically polarizing plate according to any one of claims 1 to 11, wherein at least each of the steps is performed.   The method for producing an elliptically polarizing plate according to claim 12, wherein the optically anisotropic element side of the laminate (B) is surface-treated.   The method for producing an elliptically polarizing plate according to claim 12, wherein the translucent protective film is surface-treated.   The method for producing an elliptically polarizing plate according to claim 13 or 14, wherein the surface treatment is a saponification treatment or a corona discharge treatment.   The image display apparatus which has arrange | positioned the elliptically polarizing plate in any one of Claims 1-11 on the display surface side.   The liquid crystal display device which has arrange | positioned the elliptically polarizing plate in any one of Claims 1-11 on the display surface side.   The electroluminescent element which has arrange | positioned the elliptically polarizing plate in any one of Claims 1-11 on the display surface side.   The touch panel which has arrange | positioned the elliptically polarizing plate in any one of Claims 1-11 on the display surface side.

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