JP2010151910A - Elliptical polarizer and image display device employing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an elliptical polarizer capable of reducing a degree of difficulty in observing a display image even when the display image is observed through an optical member with polarizing action, in such a case that a display screen is observed through sunglasses, and to provide an image display device employing the elliptical polarizer. <P>SOLUTION: The cured layer of ultraviolet curable acrylic resin with a hard coat property and ultraviolet cutting property, an optical anisotropic element composed of a polymer having an alicyclic structure, a polarizing element, and a translucent protective film are laminated in the order to form the elliptical polarizer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an elliptically polarizing plate, 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 in which the elliptically polarizing plate is disposed, a liquid crystal display device including the liquid crystal monitor, an electroluminescence element, and a touch panel The present invention relates to various image display devices.

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 achieve a sufficient display quality with a transmissive type and a reflective type in order to achieve good display quality, display modes include TN (twisted nematic) mode, STN (super twisted nematic) mode, ECB (electrically controlled). There are a birefringence (IPS) mode, an in-plane switching (IPS) mode, a vertical alignment (VA) mode, and an optically compensated birefringence (OCB) mode, and a polarizing plate 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).

As described above, in the image display device using the polarizing plate on the outermost surface, the display light emitted from the polarizing plate on the display side is all linearly polarized light. On the other hand, many optical members such as sunglasses have a polarizing function. Therefore, for example, when the display light 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 one of the long films 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, it has not been possible to sufficiently meet the demand for an elliptically polarizing plate having various axes of the absorption axis of the polarizing plate and the orientation axis of the retardation film and having 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 anti-glare layer, etc., and the above-mentioned layers having desired characteristics are directly formed on the liquid crystal layer. It was difficult.
Japanese Patent Laid-Open No. 9-127858 JP 2005-352068 A JP-A-4-57017 JP-A-6-242317 Japanese Patent Application Laid-Open No. 2002-48917 Japanese Patent Laid-Open No. 2004-309904

  The object of the present invention is to provide an elliptically polarizing plate that can reduce the degree of difficulty in seeing the display image even when the display image of the image display device using the polarizing plate is observed through an optical member having a polarizing action such as sunglasses. An object is to provide an image display device using the same.

That is, the present invention is as follows.
[1] A cured layer of an ultraviolet curable acrylic resin having a hard coat property and an ultraviolet cut property, an optical anisotropic element made of a polymer having an alicyclic structure, a polarizing element, and a translucent protective film, Elliptical polarizing plates stacked in this order.
[2] The optical anisotropic element is a λ / 4 retardation plate, and is laminated so that the absorption axis of the polarizing element and the slow axis of the optical anisotropic element are 45 °. 1].
[3] The elliptically polarizing plate according to the above [1] or [2], wherein an optically anisotropic element made of a liquid crystal layer is laminated between the translucent protective film and the polarizing element.
[4] The elliptically polarizing plate according to any one of [1] to [3], wherein the translucent protective film is a cellulose polymer and / or a polymer having an alicyclic structure.
[5] The elliptically polarizing plate according to any one of [1] to [4], wherein the elliptically polarizing plate has a thickness of 150 μm or less.
[6] An elliptically polarizing plate, wherein the elliptically polarizing plate according to any one of [1] to [5] is further laminated with at least one optical film.
[7] An image display device in which the elliptically polarizing plate according to any one of [1] to [6] is disposed on the display surface side.
[8] The image display device according to [7], which is a liquid crystal display device, an electroluminescence element, or a touch panel.

  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. Moreover, since it can reduce in thickness significantly and can bond in a long film form, there exists an advantage which can rationalize a bonding process rather than the conventional method.

The present invention will be described below.
The layer structure of the elliptically polarizing plate of the present invention is as follows: (I) hardened layer of UV curable acrylic resin having hard coat property and UV cut property / optical anisotropic element / polarizing element comprising polymer having alicyclic structure / It consists of a translucent protective film.
In addition, for example, (II) hard coat property in which an optical anisotropic element is laminated between a translucent protective film and a polarizing element on the side opposite to the side where the optical anisotropic element is present with respect to the polarizing element. And a cured layer of an ultraviolet curable acrylic resin having ultraviolet cutability / an optically anisotropic element composed of a polymer having an alicyclic structure / a polarizing element / an optically anisotropic element composed of a liquid crystal layer / a translucent protective film. A layer structure may be used.
In addition, each layer may be laminated | stacked through the adhesive or the adhesive agent if needed.
In addition, the translucent protective film may be provided with an overcoat layer such as a hard coat layer, an antireflection layer, an antisticking layer, a diffusion layer or an antiglare layer, if necessary.

Hereafter, the structural member used for this invention is demonstrated in order.
First, the ultraviolet curable acrylic resin having hard coat properties and ultraviolet cut properties used in the present invention will be described.
The ultraviolet curable acrylic resin used in the present invention is mainly composed of a compound having an acryloyl group and / or a compound having a methacryloyl group (hereinafter, both are collectively referred to as (meth) acrylate), and if necessary, UV-cutting property. It is a composition which consists of a compound which provides the hard-coat property added if necessary and the ultraviolet absorber which adds.

Examples of (meth) acrylates include various monofunctional and polyfunctional (meth) acrylates and (meth) acrylate oligomers.
Monofunctional (meth) acrylate monomers include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, hydroxyethyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl ( And (meth) acrylate, isobornyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, and the like.

Examples of the polyfunctional (meth) acrylate include those having 2, 3, 4, 5, 6, etc., such as ethylene glycol di (meth) acrylate and diethylene glycol di (meth) acrylate. 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, tris ((Meth) acryloxyethyl) isocyanurate, pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and the like. it can.
Moreover, desired hard coat property can also be provided by adjusting the polyfunctional (meth) acrylate amount in the resin.

  Examples of the (meth) acrylate oligomer include polyester (meth) acrylate, epoxy (meth) acrylate, urethane (meth) acrylate, polyether (meth) acrylate, and silicone (meth) acrylate. These may be a mixture. Moreover, you may use together the monomer copolymerizable with (meth) acrylate, for example, N-vinylformamide, N-vinylmorpholine, N-vinylpyrrolidone, styrene, etc. The (meth) acrylate monomer may be modified with ethylene oxide or propylene oxide for the purpose of achieving a hydrophilic / lipophilic balance.

  The ultraviolet absorber is preferably a particulate metal oxide made of an inorganic compound. The particulate metal oxide refers to those having an average primary particle diameter in the range of 1 to 100 nm and having an ultraviolet protection effect, and examples thereof include particulate titanium oxide, zinc oxide, cerium oxide, and iron oxide. It is preferable to use one or more of these particulate metal oxides in combination, preferably two or more. For example, it is preferable to combine titanium oxide and zinc oxide. The particle size distribution of the particulate metal oxide need not be particularly sharp and may be sharp or broad. The shape of the particulate metal oxide is not particularly limited, such as a spherical shape, a needle shape, a rod shape, a spindle shape, an indefinite shape, or a plate shape, and the crystal shape is not particularly limited to an amorphous shape, a rutile type, an anatase type, or the like.

  Further, these fine-particle metal oxides are conventionally known surface treatments such as fluorine compound treatment, silicone treatment, silicone resin treatment, pendant treatment, silane coupling agent treatment, titanium coupling agent treatment, oil agent treatment, N-acyl treatment. It is preferably surface-treated in advance by lysine treatment, polyacrylic acid treatment, metal soap treatment, amino acid treatment, inorganic compound treatment, plasma treatment, mechanochemical treatment, etc., especially silicone, silane, fluorine compounds, amino acid compounds It is preferable that the surface is water-repellent with one or more surface treatment agents selected from metal soaps.

  Examples of silicone treatment include coating and heat treatment of methyl hydrogen polysiloxane, examples of silane include alkylsilane treatment, and examples of fluorine compounds include perfluoroalkyl phosphate ester, perfluoropolyether, perfluoroalkyl silicone, perfluoro Alkyl / polyether co-modified silicones, perfluoroalkylsilanes, and the like are mentioned. Examples of amino acid compounds include N-lauroyl-L-lysine, and examples of metal soaps include aluminum stearate.

  Further, the particulate metal oxide used in the present invention is preferably provided with a metal oxide layer selected from silica and alumina on the particle surface in order to suppress the photocatalytic activity, and particularly preferably the particulate metal oxide. It is preferable that the above water-repellent surface treatment is performed after coating with silica and alumina. Moreover, photocatalytic activity can also be suppressed using the method of each gazette, such as Unexamined-Japanese-Patent No. 2001-191873, Unexamined-Japanese-Patent No. 2005-272267, and Unexamined-Japanese-Patent No. 2005-272270.

  Examples of commercially available fine particle metal oxides include, for example, “FINEX-25”, “FINEX-50”, “FINEX-75” (Sakai Chemical Industry Co., Ltd.), “MZ500” series. "MZ700" series (Taika Co., Ltd.) "ZnO-350" (Sumitomo Osaka Cement Co., Ltd.) and the like. Examples of the particulate titanium oxide include “TTO-55, 51, S, M, D” series (Ishihara Sangyo Co., Ltd.), “JR” series, “JA” series (Taika Co., Ltd.) and the like. In addition, examples of the particulate cerium oxide include high-purity cerium oxide sold by Nikki Co., Ltd. or Seimi Chemical Co., Ltd.

In addition, the thing surface-treated with various surface treating agents can be preferably used regardless of inorganic substances and organic substances. As the inorganic surface treatment agent, zirconium oxide, zinc oxide and the like are preferable. Examples of organic substances include siloxane, stearic acid, trimethylolpropane, and the like.
The amount of the surface treatment agent used is preferably from 3 to 45% by mass, more preferably from 5 to 35% by mass, based on the object to be processed. The higher the amount of treatment agent used, the better the dispersibility and the like, but the amount of metal oxide is relatively reduced and the absorption of ultraviolet rays is reduced, and the intended effect of cutting off ultraviolet rays is impaired. Therefore, it is preferable to select appropriately so that the above two performances can be compatible.

The ultraviolet absorber can be selected in coating amount according to the purpose, but is preferably used so that the metal oxide is 0.01 to 20 g / m ² . When the amount used is large, the absorption of ultraviolet rays increases, and when the amount is not more than the upper limit value, the decrease in transparency can be suppressed. A more preferable amount is 0.02 to 10 g / m ² , and further preferably 0.05 to ² g / m ² . As addition amount to an ultraviolet curable acrylic resin, it is 0.1-80 mass%, More preferably, it is 1-50 mass%, More preferably, it is 10-30 mass%.
In addition, organic compounds such as oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, and the like are also known as ultraviolet absorbers, but are not preferred from the viewpoint of bleeding resistance.

As described above, the hard coat property can be imparted by adjusting the amount of the polyfunctional (meth) acrylate, but it is preferable to add inorganic fine particles imparting the hard coat property. Examples of the inorganic fine particles include silicon dioxide particles, titanium dioxide particles, aluminum oxide particles, tin oxide particles, calcium carbonate particles, barium sulfate particles, talc, kaolin and calcium sulfate particles. Of these, silicon dioxide particles (colloidal silica) are particularly preferred.
The average particle size of the inorganic fine particles is preferably 1 to 2000 nm, more preferably 2 to 1000 nm, further preferably 5 to 500 nm, and most preferably 10 to 200 nm.
Commercially available products such as “Aerosil” R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, TT600 (manufactured by Nippon Aerosil Co., Ltd.) can be used as the silicon dioxide fine particles. .

The inorganic fine particles are preferably surface-treated with a silane coupling agent in consideration of dispersibility. The silane coupling agent preferably has a functional group that can be chemically bonded to the (meth) acrylate serving as the binder polymer. For example, a silane coupling agent having an ethylenically unsaturated group as a polymerizable group and a crosslinkable group is used. preferable.
The addition amount of the inorganic fine particles can be adjusted according to the amount of the polyfunctional (meth) acrylate and the kind and addition amount of the UV absorber, and cannot be generally determined, but preferably the total amount of the UV curable acrylic resin It is 10 mass%-70 mass% in the inside. Outside this range, the hard coat property is insufficient or the applicability is deteriorated.

  In addition, other known (meth) acrylate oligomers and various additives such as a photopolymerization initiator, a surface modifier, a viscosity modifier, a tackifier, an antiblocking agent, an oxidation agent may be added to the resin as necessary. An inhibitor, an antistatic agent, a heat stabilizer, an impact resistance improver, and the like may be included.

  Examples of the photopolymerization initiator include known photopolymerization initiators such as benzoin alkyl ethers, benzyl methyl ketal, hydroxyphenyl ketone, 1,1-dichloroacetophenone, thioxanthones, hexaarylbiimidazoles, acylphosphine. Examples thereof include benzophenones combined with oxides or amines. These may be used as a mixture and, if necessary, a sensitizer may be used in combination. The amount of the photopolymerization initiator used is 0.1 to 10% by mass, preferably 0.5 to 7% by mass, of the ultraviolet curable acrylic resin. Outside this range, polymerization is difficult to proceed, and light resistance due to cleaved initiator residue deteriorates.

As the surface modifier, in order to ensure surface uniformity such as coating unevenness, drying unevenness, point defects, etc., it is preferable to use either a fluorine-based surfactant or a silicone-based surfactant, or both. Fluorine-based surfactants are preferably used because their effects appear with a smaller addition amount.
Examples of the viscosity modifier and tackifier include coumarone / indene resin, terpene resin, rosin ester resin, and petroleum resin.

  The ultraviolet curable acrylic resin having a hard coat property and an ultraviolet cut property used in the present invention can be prepared by a known method. For example, required components other than the photopolymerization initiator and, if necessary, a solvent can be added and dispersed in a medium using a disperser. Examples of dispersers include sand grinder mills (eg, pinned bead mills), high speed impeller mills, pebble mills, roller mills, attritors and colloid mills. A sand grinder mill and a high-speed impeller mill are particularly preferred. Further, preliminary dispersion processing may be performed. As examples of the dispersing group used for the preliminary dispersion treatment, a ball mill, a three-roll mill, a kneader, and an extruder can be used.

  The solvent is appropriately selected according to the coating method. For example, alcohols such as ethanol, isopropanol, n-butanol, diacetone alcohol, 2-butoxyethanol, 1-methoxy-2-butoxyethanol, 1-methoxy- Glycol ethers such as 2-propanol and 1-ethoxy-2-propanol, ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate, butyl acetate and propylene glycol monoacetate, toluene, xylene and the like are preferably used.

After completion of the dispersion, a photopolymerization initiator can be added to obtain an ultraviolet curable acrylic resin composition having hard coat properties and ultraviolet cut properties.
The application of the UV curable acrylic resin having hard coat properties and UV cut properties is not particularly limited as long as the application is performed uniformly, for example, roll coating, gravure coating, bar coating, rod coating, curtain coating, A method such as die coating can be used.

When a solvent is used, it is preferable to provide means for drying the solvent after coating. The drying conditions vary depending on the type and amount of the (meth) acrylate compound and solvent used, and thus cannot be determined unconditionally, but are usually 20 ° C to 150 ° C, preferably 40 ° C to 100 ° C. Outside this range, it is not preferable because it takes time to dry the solvent and adversely affects the coated material. Examples of the drying apparatus include an oven and a continuous drying furnace.
The coating film thickness after drying is preferably 0.5 to 20 μm, and more preferably 1 to 10 μm.

Next, the ultraviolet curable acrylic resin is cured by irradiating light from a light source capable of emitting light having a wavelength suitable for the photopolymerization initiator used, such as a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a metal halide lamp, or a carbon arc. The ultraviolet irradiation amount ^is preferably ^{100mJ / cm 2 ~2000mJ / cm 2} , more preferably ^{300mJ / cm 2 ~1500mJ / cm 2} .
The pencil hardness of the surface of the cured layer of the ultraviolet curable acrylic resin having hard coat properties and ultraviolet cut properties is 2H or higher, preferably 3H or higher.
The ultraviolet ray cutting property is preferably such that the ultraviolet ray transmittance in the range of 300 nm to 370 nm is 30% or less. More preferably, it is 10% or less, and further preferably 5% or less.

Next, the polymer having an alicyclic structure used in the present invention will be described.
The polymer having an alicyclic structure used in the present invention has an alicyclic structure in a repeating unit of the polymer, a polymer containing an alicyclic structure in the main chain, and a side chain. Any polymer containing an alicyclic structure can be used.
Examples of the alicyclic structure include a cycloalkane structure and a cycloalkene structure, and a cycloalkane structure is preferable from the viewpoint of thermal stability. Although carbon number which comprises an alicyclic structure does not have a restriction | limiting in particular, Usually, 4-30 pieces, Preferably it is 5-20 pieces, More preferably, it is 5-15 pieces. When the number of carbon atoms constituting the alicyclic structure is in this range, a transparent plastic film excellent in heat resistance and flexibility can be obtained, and preferably used as a film-like support for the elliptically polarizing plate of the present invention. it can.
The proportion of the repeating unit having an alicyclic structure in the alicyclic structure-containing polymer can be appropriately selected according to the purpose of use, but is usually 50% by mass or more, preferably 70% by mass or more, more preferably 90% by mass or more. If the number of repeating units having an alicyclic structure is too small, the heat resistance is undesirably lowered. In addition, repeating units other than the repeating unit which has an alicyclic structure in an alicyclic structure containing polymer are suitably selected according to the intended purpose.

  Specific examples of the alicyclic structure-containing polymer include (i) a norbornene polymer, (ii) a monocyclic olefin polymer, (iii) a cyclic conjugated diene polymer, and (iv) a vinyl alicyclic polymer. Examples include hydrocarbon polymers and their hydrides. Among these, norbornene-based polymers are preferable from the viewpoints of transparency and moldability.

(I) Norbornene-based polymer Specific examples of the norbornene-based polymer include ring-opening polymers of norbornene-based monomers, and ring-opening of norbornene-based monomers and other monomers capable of ring-opening polymerization. Examples thereof include copolymers, hydrides thereof, addition polymers of norbornene monomers, addition polymers with other monomers copolymerizable with norbornene monomers, and the like. Among these, from the viewpoint of transparency, a hydride of a ring-opening (co) polymer of a norbornene-based monomer is particularly preferable.

Examples of the norbornene-based monomer include dicyclo [2.2.1] hept-2-ene (common name: norbornene), tricyclo [4.3.0.1 ^2.5 ] dec-3-ene (conventional). Name: methanotetrahydrofluorene), tetracyclo [4.4.0.1 ^2.5 . 1 ^7.10 ] dodec-3-ene (tetracyclododecene) and the like, and these compounds may have a substituent. Examples of the substituent include an alkyl group, an alkenyl group, an alkoxycarbonyl group, and a carboxyl group. Further, these substituents may be the same or different from each other and may be bonded to the ring. Norbornene monomers can be used alone or in combination of two or more.

Examples of other monomers capable of ring-opening polymerization with norbornene monomers include, for example, monocyclic olefins such as cyclohexene, cycloheptene, and cyclooctene and derivatives thereof; cyclic conjugated dienes such as cyclohexadiene and cycloheptadiene; Derivatives thereof; and the like.
Ring-opening polymers of norbornene-based monomers and ring-opening copolymers of norbornene-based monomers and other monomers copolymerizable therewith are polymerized in the presence of a ring-opening polymerization catalyst. Can be obtained. Known ring-opening polymerization catalysts can be used.
A ring-opening polymer of a norbornene-based monomer or a hydride of a ring-opening copolymer of a norbornene-based monomer and another monomer capable of ring-opening polymerization uses a known hydrogenation catalyst, and carbon- It is obtained by hydrogenating carbon unsaturated bonds, preferably 90% or more.

  Other monomers that can be addition copolymerized with norbornene monomers include, for example, α-olefins having 2 to 20 carbon atoms such as ethylene and propylene, and derivatives thereof; cycloolefins such as cyclobutene and cyclopentene, and derivatives thereof. A non-conjugated diene such as 1,4-hexadiene; These monomers can be used alone or in combination of two or more. In these, an alpha olefin is preferable and ethylene is more preferable.

  The addition polymer of norbornene monomer and the addition copolymer of norbornene monomer and other monomer copolymerizable with it must be polymerized in the presence of an addition polymerization catalyst. Can be obtained. As the addition polymerization catalyst, a known catalyst can be used.

  Examples of the norbornene-based (co) polymer include those manufactured by Nippon Zeon Co., Ltd., trade names “ZEONOR” and “ZEONEX”; manufactured by JSR Corporation, and trade names “ARTON”; manufactured by Hitachi Chemical Co., Ltd. Trade name “OPTOREZ”; trade name “APEL” manufactured by Mitsui Chemicals, Inc. is commercially available.

(Ii) Monocyclic cycloolefin polymer Examples of the monocyclic cycloolefin polymer include addition polymer polymers such as cyclohexene, cycloheptene, and cyclooctene.

(Iii) Cyclic conjugated diene polymers and their hydrides Examples of cyclic conjugated diene polymers include 1,2-addition polymerization of cyclic conjugated diene monomers such as cyclopentadiene and cyclohexadiene, or 1, Examples include 4-addition polymerized polymers and hydrides thereof.

(Iv) Vinyl alicyclic hydrocarbon polymer and hydride thereof The vinyl alicyclic hydrocarbon polymer is a polymer having a repeating unit derived from vinyl cycloalkane or vinyl cycloalkene. Examples of the vinyl alicyclic hydrocarbon polymer include polymers of vinyl alicyclic hydrocarbon compounds such as vinyl cyclohexane and hydrides thereof; polymers of vinyl aromatic hydrocarbon compounds such as styrene and α-methyl styrene. And hydrides of the aromatic ring moiety. The vinyl alicyclic hydrocarbon polymer is a random copolymer of a vinyl alicyclic hydrocarbon compound or a vinyl aromatic hydrocarbon compound and another monomer copolymerizable with these monomers, It may be a copolymer such as a block copolymer and a hydride thereof.

  The molecular weight of the polymer having an alicyclic structure used in the present invention is the weight in terms of polyisoprene or polystyrene measured by gel permeation chromatography using cyclohexane (toluene when the polymer is not dissolved) as a solvent. The average molecular weight is usually in the range of 10,000 to 300,000, preferably 20,000 to 200,000. When the molecular weight is in such a range, the mechanical strength and molding processability of the transparent plastic film are highly balanced, and it is suitable as a constituent material of the elliptically polarizing plate of the present invention.

The glass transition temperature of the polymer having an alicyclic structure may be appropriately selected according to the purpose of use, but is preferably 80 ° C or higher, more preferably in the range of 100 ° C to 250 ° C. When the glass transition temperature is in such a range, it is excellent in durability without causing deformation or stress during use at high temperatures, and is suitable as a constituent material of the elliptically polarizing plate of the present invention.
The optical anisotropic element comprising a polymer having an alicyclic structure in the present invention can be obtained by forming the polymer into a film and stretching it as necessary. The polymer can be molded by a known molding method.

Examples of the method for forming the film include a solution casting method and a melt extrusion method. Among these, the melt extrusion molding method is preferable from the viewpoint of reducing the content of volatile components and the thickness unevenness in the film and productivity. Further, examples of the melt extrusion molding method include a method using a die such as a T die and an inflation method, but a method using a T die is preferable in terms of excellent thickness accuracy.
When a method using a T die is employed as a method for forming a film, the melting temperature in an extruder having a T die is preferably 80 ° C. to 180 ° C. higher than the glass transition temperature of the polymer used. It is more preferable to set the temperature to be higher by 150 ° C. If the melting temperature in the extruder is excessively low, the fluidity of the polymer is lowered. Conversely, if the melting temperature is excessively high, the polymer may be deteriorated.

Furthermore, it is preferable to pre-dry the polymer used before forming into a film. For example, the preliminary drying is performed using a hot air dryer in the form of pellets. The drying temperature is preferably 100 ° C. or more, and the drying time is preferably 2 hours or more. By performing preliminary drying, the amount of volatile components in the film can be reduced. Furthermore, foaming of the extruded polymer can be prevented.
The polymer to be used preferably has a saturated water absorption of less than 0.05%. By using a material having a saturated water absorption rate of less than 0.05%, when forming a laminate on the resulting film, moisture may be released and the quality may deteriorate or productivity may decrease. Absent. Further, the film does not expand and contract due to moisture absorption, and the laminated layer does not peel from the film. In particular, when used in a large-screen liquid crystal display device, it is possible to eliminate image quality deterioration caused by dimensional changes due to moisture absorption.

  5-150 micrometers is preferable, as for the thickness of a film, 20-120 micrometers is more preferable, and 20-80 micrometers is still more preferable. If the thickness of the film is equal to or greater than the lower limit, problems such as a decrease in film strength are unlikely to occur. If the thickness is equal to or less than the upper limit, the mass increases excessively, particularly when used for a large television of 20 inches or more. This is preferable because it is less likely to cause disadvantages such as being disadvantageous.

When the obtained film exhibits the desired optical anisotropy, it is not necessary to perform stretching, but when the optical anisotropy is insufficient, the film is stretched by a known stretching method to express the desired optical anisotropy. You can do it. Desirable optical anisotropy is that the film exhibits the function of a λ / 4 retardation plate.
For example, by obtaining a film having a film major axis direction and a slow axis of 45 ° by the method of Japanese Patent Application Laid-Open No. 2008-221834, roll-to-roll is possible at the time of bonding with a polarizing element. .

As an optical anisotropic element composed of a liquid crystal layer, a known low-molecular liquid crystalline compound, a composition composed of a high-molecular liquid crystalline compound or a mixture thereof is developed and oriented by a known method, and the orientation is fixed. As the liquid crystal phase, nematic, twisted nematic, smectic phase and the like can be used, and as the alignment form, homogeneous, tilt, hybrid tilt, and homeotropic alignment can be mentioned.
The retardation (optical anisotropy Δn × liquid crystal layer thickness) of the optical anisotropic element composed of the liquid crystal layer may be appropriately selected depending on the use of the elliptically polarizing plate of the present invention, but is usually 50 nm to 2000 nm, preferably 80 nm to 1000 nm. It is. Outside this range, the desired effect cannot be seen, and coloring may appear depending on the viewing direction.
In addition, although the liquid crystal layer may be formed on the support film, the form which peeled the support film from the request | requirement of film thickness is preferable.

  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, for example, by dyeing polyvinyl alcohol 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 and anti-blocking agent by washing the polyvinyl alcohol film with water, it also has the effect of preventing unevenness such as uneven dyeing 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.

  As the translucent protective film provided on one surface of the polarizing element, an optically isotropic substrate is preferable. For example, a triacetyl cellulose film such as Fujitac (product of Fujifilm) or Konicatak (product of Konica), Polymers with an alicyclic structure such as Arton Film (product of JSR), Zeonore Film, Zeonex Film (product of Nippon Zeon), TPX Film (product of Mitsui Chemicals), and Acryprene Film (product of Mitsubishi Rayon) Although it is mentioned, the polymer which has a triacetyl cellulose and an alicyclic structure from the heat resistance, moisture resistance, etc. when it is set as an elliptically polarizing plate is preferable. Generally the thickness of a translucent protective film is 150 micrometers, 1-100 micrometers is preferable and it is especially preferable to set it as 5-50 micrometers.

Next, the manufacturing method of the elliptically polarizing plate of this invention is demonstrated.
Although there are various layer configurations of the elliptically polarizing plate obtained in the present invention, for example, the following configurations can be exemplified.
(I) Hardened layer of UV curable acrylic resin having hard coat property and UV cut property / Optical anisotropy / polarizing element / translucent protective film made of polymer having alicyclic structure (II) Hard coat property In addition, a cured layer of an ultraviolet curable acrylic resin having ultraviolet cutability / an optical anisotropy composed of a polymer having an alicyclic structure / a polarizing element / an optical anisotropic element composed of a liquid crystal layer / a translucent protective film Each layer may be laminated via a pressure-sensitive adhesive or an adhesive (hereinafter referred to as an adhesive / adhesive) as necessary.

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) An ultraviolet curable acrylic resin layer having a hard coat property and an ultraviolet cut property is formed on an optically anisotropic element made of a polymer having an alicyclic structure, and the acrylic resin layer is cured, A step of obtaining a laminate (A) comprising an optically anisotropic element comprising a cured layer of an ultraviolet curable acrylic resin having ultraviolet cutability / a polymer having an alicyclic structure;
(2) Cured layer / grease of ultraviolet curable acrylic resin having hard coat property and ultraviolet cut property by laminating the laminate (A), the polarizing element, and the translucent protective film via an adhesive / adhesive. It can be manufactured by a step of obtaining an optical anisotropic element / viscous / adhesive layer / polarizing element / viscous / adhesive layer / translucent protective film made of a polymer having a cyclic structure.

Next, the manufacturing method of structure (II) is demonstrated.
Configuration (II) is
(1) An ultraviolet curable acrylic resin layer having a hard coat property and an ultraviolet cut property is formed on an optically anisotropic element made of a polymer having an alicyclic structure, and the acrylic resin layer is cured, A step of obtaining a laminate (A) comprising an optically anisotropic element comprising a cured layer of an ultraviolet curable acrylic resin having ultraviolet cutability / a polymer having an alicyclic structure;
(2) Ultraviolet rays having hard coat properties and UV-cutting properties by adhering the laminate (A), a polarizing element, an optically anisotropic element comprising a liquid crystal layer, and a translucent protective film via an adhesive / adhesive. Cured layer of curable acrylic resin / Optical anisotropic element made of polymer having alicyclic structure / Tacky / adhesive layer / Polarizing element / Tacky / adhesive layer / Optical anisotropic element made of liquid crystal layer / Tacky / adhesion It can manufacture by the process of obtaining an agent layer / translucent protective film.
In addition, when laminating each layer, the surface may be subjected to treatment such as corona discharge treatment.

The above-mentioned adhesive / adhesive is not particularly limited as long as it is an optical grade having an appropriate adhesive force at both interfaces, for example, acrylic polymer system, epoxy resin system, ethylene-vinyl acetate copolymer system, rubber Various reactive types such as thermosetting type and / or a mixture type thereof, thermosetting type and / or photocurable type, electron beam curable type, etc., but light (UV) curable type is easy to process. It is preferable from the above.
Among them, like UV curable acrylic adhesives and adhesives, those with excellent optical transparency, moderate wettability, cohesiveness and adhesive properties, and excellent weather resistance and heat resistance are preferred. Can be used.

Acrylic viscosity / adhesives include various (meth) acrylic monofunctional and polyfunctional monomers, oligomers such as polyester (meth) acrylate and polyurethane (meth) acrylate, photopolymerization initiators, viscosity adjustment An agent (thickening agent), an additive such as a surfactant or a dispersant, and the like may be added as appropriate. In addition, the reaction (curing) conditions of the UV curable adhesive / adhesive change depending on the components constituting the adhesive / adhesive, the viscosity, the reaction temperature, and the like. Well, for example, light beams such as ultra-high pressure mercury lamp, high pressure mercury lamp, low pressure mercury lamp, carbon arc, xenon arc, metal halide lamp can be used. The amount of active energy rays to be irradiated is arbitrary as long as the photopolymerization initiator generates radicals, but ultraviolet rays of 200 to 400 nm are 0.1 to 1000 mJ / cm ² , preferably 10 to 600 mJ / cm ² . Irradiate in range. The acceleration voltage in the case of the electron beam curable type is usually 10 kV to 200 kV, preferably 25 kV to 100 kV.

  The photopolymerization initiator is not particularly limited as long as it generates radicals by active energy rays such as ultraviolet rays. Specific examples include acetophenones, benzoin ethers, benzophenones, thioxanthones, benzyl ketals, acylphosphine oxides, bisimidazole derivatives used in conventional UV curable adhesives and paints. And trihalomethyl group derivatives.

  The addition amount of a photoinitiator is 0.01-15 mass parts with respect to 100 mass parts of structural components of an adhesive agent, Preferably it is 0.1-7 mass parts. Two or more of these photopolymerization initiators may be used in combination. A sensitizer having an amino group such as ethyl dimethylaminobenzoate may be used in combination.

  The formation of the adhesive / adhesive layer can be performed by an appropriate method. As an example, for example, a 10-40 mass% adhesive / adhesive solution in which a base polymer or a composition thereof is dissolved or dispersed in a solvent composed of a single solvent or a mixture of appropriate solvents such as toluene and ethyl acetate. A method in which it is directly attached on an optical anisotropic element, a polarizing element, etc. by an appropriate development method such as a casting method or a coating method, or by forming an adhesive / adhesive layer on a separator And a method of transferring the light onto the optical anisotropic element or the polarizing element.

  The thickness of the adhesive / adhesive layer is not particularly limited as long as the members to be laminated can be adhered and sufficient adhesion can be maintained, and is appropriately selected according to the properties of the adhesive / adhesive and the adhesive / adhesive member can do. Since there is a strong demand for reduction in the total thickness of the resulting laminate (elliptical polarizing plate), the thickness of the adhesive / adhesive is preferably thin, but is usually 2 to 80 μm, preferably 5 to 50 μm, more preferably 5 to 5 μm. 40 μm. Outside this range, it is not preferable because the adhesive strength is insufficient, or it oozes out from the end portion during lamination or storage of the laminate.

An optically anisotropic element comprising a polymer having the above alicyclic structure, for example, a film having a film major axis direction and a slow axis of 45 °, and a polarizing element by the method of JP-A-2008-221835 The optically anisotropic element composed of a liquid crystal layer and the translucent protective film can be laminated in a roll-to-roll form as it is in the form of a long film.
The thickness of the elliptically polarizing plate of the present invention thus obtained is preferably 150 μm or less.

  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. As the polymer stretched film, a uniaxial or biaxial retardation film composed of a cellulose-based, polycarbonate-based, polyarylate-based, polysulfone-based, polyacryl-based, polyethersulfone-based, polymer having an alicyclic structure, or the like. It can be illustrated. 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.

The elliptically polarizing plate of the present invention can be applied to various image display devices such as liquid crystal display devices, electroluminescence elements, touch panels and the like.
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, it replaces with a display surface side polarizing plate, and there is no restriction | limiting in particular except the point which uses the elliptically polarizing plate of this invention.

The polarizing plate used in the liquid crystal display device is not particularly limited, and a polarizing plate obtained from the same polarizing element as that used in the above-described elliptical circular polarizing plate 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 having the property of aligning the liquid crystal itself, a substrate itself lacking alignment ability, but a transparent substrate provided with an alignment film having the property of aligning liquid crystal, etc. Can also 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.

  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. As the polymer stretched film, a uniaxial or biaxial retardation film composed of a cellulose-based, polycarbonate-based, polyarylate-based, polysulfone-based, polyacryl-based, polyethersulfone-based, polymer having an alicyclic structure, or the like. It can be illustrated. 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 to give 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 making 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. In general, 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 emitting body (organic electroluminescence light emitting body). 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 may be disposed directly on the observer side of the organic EL display device via a sticky / adhesive.

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. What is necessary is just to arrange | position the elliptically polarizing plate of this invention directly to the observer side of a touch panel through an adhesive agent instead of a circularly-polarizing plate.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. The analysis and measurement methods used in the examples are as follows.
(1) Microscope observation The alignment state of the liquid crystal was observed with an Olympus BH2 polarizing microscope.
(2) Measurement of logarithmic viscosity Using an Ubbelohde viscometer, it was measured at 30 ° C. in a phenol / tetrachloroethane (60/40 mass ratio) mixed solvent.
(3) Ellipsometry measurement An ellipsometer (DVA-36VWLD) manufactured by Mizoji Optical Corporation was used.
(4) Hard coat property test JIS-K5600-5-4 Evaluation by the scratch hardness method was performed.
(5) UV absorption measurement UV absorption measurement was performed with an ultraviolet-visible spectrophotometer V-570 (manufactured by JASCO Corporation).

[Example 1]
UV clear T7735 (manufactured by Resino Color Kogyo Co., Ltd.) as a UV curable acrylic resin having a hard coat property and an ultraviolet cut property on a commercially available λ / 4 retardation film (45 ° obliquely stretched ZEONOR: manufactured by ZEON CORPORATION) After pre-drying at 70 ° C. for 2 minutes, the resin is irradiated with 1000 mJ / cm ² at a strength of 100 mW / cm ² or higher with a high-pressure mercury lamp to cure the UV-curable acrylic resin having hard coat properties and UV-cutting properties. A laminate A composed of a layer (4 μm thick) / λ / 4 retardation film was obtained. The ultraviolet-visible light spectrum of the laminate A and 45 ° obliquely stretched zeonore is shown in FIG.
Next, a polarizing plate (adhesive / polarizing element / triacetyl cellulose (TAC) film) is placed on the retardation film side of the laminate, and the absorption axis of the polarizing element and the slow axis of the λ / 4 retardation film are 45 ° C. Then, an elliptically polarizing plate (cured layer of UV curable acrylic resin / λ / 4 retardation film / adhesive / polarizing element / TAC film) was obtained.
The thickness of the obtained elliptically polarizing plate was 106 μm, and the pencil hardness of the cured layer of the ultraviolet curable acrylic resin was 3H.

[Comparative Example 1]
On a commercially available λ / 4 retardation film (45 ° obliquely stretched ZEONOR: manufactured by Nippon Zeon Co., Ltd.), a polarizing plate (adhesive / polarizing element / TAC film) is added to the absorption axis of the polarizing plate and the λ / 4 retardation film. A laminated elliptically polarizing plate (retardation film / adhesive / polarizing element / TAC film) was obtained so that the slow axis was 45 ° C. The obtained elliptically polarizing plate is thinner than Example 1 (102 μm), but the pencil hardness is H and the surface hardness is inferior. Further, as shown in FIG. 1, ultraviolet rays are transmitted, and the deterioration of the polarizing element is promoted.

[Comparative Example 2]
On a commercially available λ / 4 retardation film (45 ° obliquely stretched ZEONOR: manufactured by Nippon Zeon Co., Ltd.), a polarizing plate (adhesive / polarizing element / TAC film) is added to the absorption axis of the polarizing plate and the λ / 4 retardation film. After laminating so that the slow axis is 45 ° C., hard coat TAC (45 μm) is pasted to the surface of the retardation film with an adhesive instead of UV curable acrylic resin with hard coat properties and UV cut properties. As a result, an elliptically polarizing plate (hard coat TAC / adhesive / retardation film / adhesive / polarizing element / TAC film) was obtained. The thickness of the elliptically polarizing plate thus obtained is 170 μm, which is inferior in terms of thickness compared to that of Example 1.

[Example 2]
(Preparation of liquid crystalline composition solution, optical anisotropic element A and laminate B)
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. Next, 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 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.
By reacting 90 mmol of biphenyl dicarbonyl chloride, 10 mmol of terephthaloyl chloride, and 105 mmol of S-2-methyl-1,4-butanediol in dichloromethane at room temperature for 20 hours, the reaction solution is poured into methanol and reprecipitated. 12.0 g of liquid crystalline polyester (polymer 2) was obtained. The logarithmic viscosity of polymer 2 was 0.12.
A mixed polymer composed of 19.82 g of polymer 1 and 0.18 g of polymer 2 was dissolved in N-methylpyrrolidone so as to be 20% by mass to prepare a liquid crystal composition solution.
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 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. The liquid crystalline composition was aligned, then cooled to room temperature to fix the alignment, and a laminate B of the optical anisotropic element A composed of a liquid crystal layer and a PEEK film was obtained. This liquid crystal layer was nematically aligned and Δnd was 140 nm.

(Preparation of laminate C)
A commercially available UV curable adhesive (UV-3400, manufactured by Toagosei Co., Ltd.) was applied as an adhesive layer 1 to the thickness of 5 μm on the optical anisotropic element A of the laminate B, and a TAC film ( 40 [mu] m, 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 A / adhesive layer 1 / TAC film is integrated to transfer the optically anisotropic element A onto the TAC film, and the TAC film / A laminate C composed of adhesive layer 1 / optically anisotropic element A was obtained.

(Preparation of elliptically polarizing plate D)
On one side of the polarizing element in which iodine was adsorbed to the stretched polyvinyl alcohol, an acrylic adhesive was used to continuously bond the laminated body C on the optical anisotropic element A side. The other surface of the polarizing element is subjected to corona treatment on the zeonore surface of the laminate A produced in Example 1 under the condition of 250 W · min / m ² , and within 30 seconds after the corona treatment, the corona treatment surface Were bonded together to produce an elliptically polarizing plate D. 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 the elliptically polarizing plate having good circular polarization characteristics was obtained. 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.

(Visibility on LCD)
Using one elliptical polarizing plate D above, instead of the upper polarizing plate, a commercially available IPS liquid crystal television arranged in the order of the backlight, the lower polarizing plate, the IPS liquid crystal cell, and the upper polarizing plate, The elliptically polarizing plate D produced in Example 2 was disposed so that the optical anisotropic element A 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.

(Visibility on organic EL display)
Example 1 in place of the λ / 4 film and the polarizing plate for a commercially available organic EL display in which the above-mentioned elliptical polarizing plate D is used and arranged in the order of the organic EL element, the λ / 4 film, and the polarizing plate. The elliptically polarizing plate D produced in the above was placed. 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)
Using one elliptical polarizing plate D, a λ / 4 film and an upper polarizing plate are used for a commercially available liquid crystal display device with a touch panel arranged in the order of a liquid crystal display device, a touch panel, a λ / 4 film, and an upper polarizing plate. Instead of this, the elliptically polarizing plate D produced in Example 2 was disposed. 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.

The ultraviolet visible light spectrum of the laminated body A obtained in Example 1 and 45 degree diagonally stretched zeonore is shown.

Claims (8)

  A cured layer of an ultraviolet curable acrylic resin having a hard coat property and an ultraviolet cut property, an optical anisotropic element made of a polymer having an alicyclic structure, a polarizing element, and a translucent protective film are laminated in this order. An elliptical polarizing plate.   The optically anisotropic element is a λ / 4 retardation plate, and is laminated so that the absorption axis of the polarizing element and the slow axis of the optically anisotropic element are 45 °. Elliptical polarizing plate.   3. The elliptically polarizing plate according to claim 1, wherein an optical anisotropic element made of a liquid crystal layer is laminated between the translucent protective film and the polarizing element.   4. The elliptically polarizing plate according to claim 1, wherein the translucent protective film is a cellulosic polymer and / or a polymer having an alicyclic structure.   The elliptically polarizing plate according to claim 1, wherein the elliptically polarizing plate has a thickness of 150 μm or less.   6. An elliptically polarizing plate, further comprising at least one optical film laminated on the elliptically polarizing plate according to claim 1.   The image display apparatus which has arrange | positioned the elliptically polarizing plate in any one of Claims 1-6 on the display surface side.   The image display device according to claim 7, wherein the image display device is a liquid crystal display device, an electroluminescence element, or a touch panel.

Images