KR101814252B1

KR101814252B1 - Polarizing plate laminated with retardation layer and image display device

Info

Publication number: KR101814252B1
Application number: KR1020150126580A
Authority: KR
Inventors: 다케하루 기타가와; 다다시 고지마; 마사카즈 모치즈키
Original assignee: 닛토덴코 가부시키가이샤
Priority date: 2015-01-23
Filing date: 2015-09-07
Publication date: 2018-01-02
Also published as: KR20160091226A; CN105824069B; CN105824069A; JP2016136181A; JP5913648B1

Abstract

There is provided a thin polarizing plate with a retardation layer which is easy to adjust curl at the time of curing, curls at the time of heating, and further has excellent appearance durability upon heating. The polarizing plate with a retardation layer of the present invention has a polarizing plate including a first protective layer, a polarizer and a second protective layer, and a retardation layer. The thickness of the polarizing plate is 80 占 퐉 or less, and the thickness of the retardation layer is 60 占 퐉 or less. The difference between the thickness of the first protective layer and the thickness of the second protective layer is 10 占 퐉 or less and the difference between the thickness of the polarizing plate and the thickness of the retardation layer is 25 占 퐉 or less. The polarizer has a thickness of 12 占 퐉 or less, a boric acid content of 18% by weight or more, an iodine content of 2.1% by weight or more, and a single transmittance of 44.0% to 45.5%.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polarizing plate having a retardation layer and an image display device,

The present invention relates to a polarizing plate with a retardation layer and an image display apparatus using the same.

2. Description of the Related Art Recently, an image display apparatus typified by a liquid crystal display apparatus and an organic EL display apparatus is rapidly spreading. As the image display apparatus, a polarizing plate and a retardation plate are typically used. Practically, a polarizing plate with a retardation layer in which a polarizing plate and a retardation plate are integrated is widely used (for example, Japanese Patent Publication No. 3325560). Recently, with the demand for thinning of an image display apparatus becoming stronger , The demand for a thinner polarizing plate with a retardation layer becomes stronger. However, attempting to reduce the thickness of the polarizing plate with a retardation layer makes it difficult to adjust the curl at the time of bonding the polarizing plate and the retardation layer, or curling occurs when the polarizing plate with a retardation layer thus obtained is heated, There is a problem in that appearance durability at the time of heating is insufficient and stripe unevenness occurs. If one of the above three problems is attempted to be improved, the other one or two problems become more significant, and a thin polarizing plate with a retardation layer, which solves all of these problems, still can not be actually obtained.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-described problems of the prior art, and its main object is to provide a method of manufacturing a laminated film, which is capable of easily adjusting curl at the time of curing and curling at the time of heating, And to provide a polarizing plate.

The polarizing plate with a retardation layer of the present invention has a polarizing plate including a first protective layer, a polarizer and a second protective layer, and a retardation layer. The thickness of the polarizing plate is 80 占 퐉 or less, and the thickness of the retardation layer is 60 占 퐉 or less. The difference between the thickness of the first protective layer and the thickness of the second protective layer is 10 占 퐉 or less and the difference between the thickness of the polarizing plate and the thickness of the retardation layer is 25 占 퐉 or less. The polarizer has a thickness of 12 占 퐉 or less, a boric acid content of 18% by weight or more, an iodine content of 2.1% by weight or more, and a single transmittance of 44.0% to 45.5%.

In one embodiment, the retardation layer is composed of a resin film selected from a cyclic olefin based resin film and a polycarbonate based resin film.

In one embodiment, the retardation layer functions as a lambda / 4 plate.

According to another aspect of the present invention, an image display apparatus is provided. The image display apparatus includes the polarizing plate with a retardation layer.

According to the present invention, in the polarizing plate with a thin retardation layer, the thickness of the polarizing plate and the polarizer and the protective layer constituting the polarizing plate, the thickness of the retardation layer and the thickness difference thereof are optimized to a predetermined range, And the content of iodine is optimized, it is possible to actually obtain a thin polarizing plate with a retardation layer which is easy to adjust curl at the time of curing, suppresses curling at the time of heating, and further exhibits excellent appearance durability upon heating.

1 is a schematic cross-sectional view of a polarizing plate with a retardation layer according to an embodiment of the present invention.
2 is a photographic image showing the appearance after the heat resistance test of the polarizing plate with a retardation layer of Comparative Example 4. Fig.

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these embodiments.

(Definition of terms and symbols)

The definitions of the terms and symbols in the present specification are as follows.

(1) Refractive index (nx, ny, nz)

"Nx" is the refractive index in the direction in which the in-plane refractive index is the maximum (that is, the slow axis direction), "ny" is the refractive index in the direction perpendicular to the slow axis in the plane Refractive index in the thickness direction.

(2) In-plane retardation (Re)

"Re (λ)" is the in-plane retardation measured with light having a wavelength of λ nm at 23 ° C. For example, " Re (550) " is an in-plane retardation measured at a wavelength of 550 nm at 23 deg. Re (?) Is obtained by the formula: Re (?) = (Nx - ny) xd, where d (nm) is the thickness of the layer (film).

(3) The retardation in the thickness direction (Rth)

"Rth (?)" Is a retardation in the thickness direction measured by light having a wavelength of? Nm at 23 占 폚. For example, " Rth (550) " is the retardation in the thickness direction measured with light having a wavelength of 550 nm at 23 deg. Rth (?) Is obtained by the formula: Rth (?) = (Nx - nz) xd, where d (nm) is the thickness of the layer (film).

(4) Nz coefficient

The Nz coefficient is obtained by Nz = Rth / Re.

A. Overall Configuration of Polarizer with a Phase Difference Layer

1 is a schematic cross-sectional view of a polarizing plate with a retardation layer according to an embodiment of the present invention. The polarizing plate 100 with a retardation layer of the present embodiment has a polarizing plate 10 and a retardation layer 20 disposed on one side of the polarizing plate 10. The polarizing plate 10 includes a polarizer 11 and a first protective layer 12 disposed on one side of the polarizer 11 and a second protective layer 13 disposed on the other side of the polarizer 11 ). In the illustrated example, the retardation layer 20 is disposed on the second protective layer 13 side of the polarizing plate 10. In the embodiment of the present invention, the thickness of the polarizing plate 10 is 80 占 퐉 or less and the thickness of the retardation layer 20 is 60 占 퐉 or less. The difference between the thickness of the first protective layer 12 and the thickness of the second protective layer 13 is 10 占 퐉 or less and the difference between the thickness of the polarizing plate 10 and the thickness of the retardation layer 20 is 25 占 퐉 or less. The thickness of the polarizer 11 is 12 占 퐉 or less, the content of boric acid is 18% by weight or more, the content of iodine is 2.1% by weight or more, and the transmittance of single crystals is 44.0% to 45.5%. Hereinafter, each layer constituting the polarizing plate with a retardation layer and the optical film will be described in more detail.

B. Polarizer

B-1. Polarizer

As the polarizer 11, any appropriate polarizer may be employed. For example, the resin film forming the polarizer may be a single-layer resin film or a laminate of two or more layers.

As specific examples of the polarizer composed of the single-layer resin film, a hydrophilic polymer film such as a polyvinyl alcohol (PVA) film, a partially formalized PVA film, and an ethylene / vinyl acetate copolymerization system partially saponified film, Dyes such as dyestuffs, and polyene-based oriented films such as dehydrated PVA and dehydrochlorinated polyvinyl chloride films. Preferably, a polarizer obtained by dying a PVA-based film with iodine and uniaxially stretching is used from the viewpoint of excellent optical characteristics.

The dyeing by iodine is carried out, for example, by immersing a PVA-based film in an iodine aqueous solution. The stretching ratio of the uniaxial stretching is preferably 3 to 7 times. The stretching may be performed after the dyeing treatment, or may be performed while dyeing. Further, it may be dyed after stretching. If necessary, swelling treatment, crosslinking treatment, washing treatment, drying treatment and the like are performed on the PVA film. For example, by dipping the PVA film in water before dying, the PVA film can be cleaned, and the PVA film can be swollen, thereby preventing uneven dyeing.

Specific examples of the polarizer obtained by using the laminate include a laminate of a resin substrate and a PVA resin layer (PVA resin film) laminated on the resin substrate, or a laminate of a resin substrate and a PVA resin layer And a polarizer obtained by using a laminate of A polarizer obtained by using a laminate of a resin substrate and a PVA resin layer formed on the resin substrate can be produced by, for example, applying a PVA resin solution to a resin substrate and drying the PVA resin layer to form a PVA resin layer on the resin substrate , Obtaining a laminate of a resin substrate and a PVA-based resin layer, stretching and staining the laminate to prepare a PVA-based resin layer as a polarizer. In the present embodiment, the stretching typically involves immersing the laminate in an aqueous solution of boric acid and stretching. In addition, the stretching may further include, if necessary, air-stretching the laminate at a high temperature (for example, 95 캜 or higher) before stretching in an aqueous solution of boric acid. The obtained laminate of the resin substrate / polarizer may be used as is (that is, the resin substrate may be the protective layer of the polarizer), the resin substrate is peeled from the laminate of the resin substrate / polarizer, May be laminated and used. Details of the method for producing such a polarizer are described in, for example, Japanese Laid-Open Patent Publication No. 2012-73580. This publication is incorporated herein by reference in its entirety.

The thickness of the polarizer is 12 占 퐉 or less, preferably 1 占 퐉 to 12 占 퐉, and more preferably 3 占 퐉 to 12 占 퐉, as described above. By setting the thickness of the polarizer to be in the above-described range in the thin polarizing plate with a retardation layer with optimized thickness and thickness difference, the content of boric acid in the polarizer, and the iodine content, the ease of curl adjustment at the time of coherence is maintained , It is possible to suppress streak streaks and to suppress curling at the time of heating while maintaining the appearance durability at the time of heating.

The boric acid content of the polarizer is 18 wt% or more, preferably 18 wt% to 25 wt%, as described above. By optimizing the boric acid content of the polarizer in such a range in a thin polarizing plate with a retardation layer with a predetermined layer thickness and thickness difference optimized, by the synergistic effect with optimization of the iodine content to be described later, It is possible to maintain the ease of use and to suppress curling at the time of heating while suppressing stripe unevenness and to improve the appearance durability during heating. The boric acid content can be calculated, for example, from the neutralization method as the amount of boric acid contained in the polarizer per unit weight by using the following equation.

The iodine content of the polarizer is 2.1% by weight or more, preferably 2.1% by weight to 3.5% by weight, as described above. It is possible to optimize the iodine content of the polarizer in such a thin polarizing plate with a predetermined layer thickness and thickness difference optimized in such a range so that the ease of curl adjustment at the time of curing by the synergistic effect with the optimization of the boric acid content Can be satisfactorily maintained, curling at the time of heating can be well suppressed, and stain unevenness can be suppressed, thereby improving the appearance durability during heating. In the present specification, the "iodine content" means the amount of all iodine contained in the polarizer (PVA resin film). More specifically, in the polarizer, iodine exists in the form of iodine ion (I ^- ), iodine molecule (I ₂ ), polyiodide ion (I ₃ ^- , I ₅ ^- ), The content means the amount of iodine including all of these forms. The iodine content can be calculated, for example, by the calibration curve method of fluorescent X-ray analysis. In addition, the poly iodide ion exists in the form of a PVA-iodine complex in the polarizer. By forming such a complex, the absorption dichroism can be expressed in the wavelength range of visible light. Specifically, the complex of PVA and triiodide (PVA · I ₃ ^- ) has an absorption peak near 470 nm, and the complex of PVA and oodide ion (PVA · I ₅ ^- Peak. As a result, the polyiodide ion can absorb light in a wide range of visible light depending on its form. On the other hand, the iodine ion (I < ^- >) has an absorption peak near 230 nm and is not substantially involved in the absorption of visible light. Therefore, the poly iodide ions present in the complex state with PVA can mainly be involved in the absorption performance of the polarizer.

It is one of the characteristics of the present invention that the boric acid content and the iodine content in the polarizer are set in the above-described range. That is, the boric acid content and the iodine content as described above can cope with a new problem caused by making the polarizer to have a very thin thickness as described above, and can contribute to improvement of the appearance durability of the resulting polarizing plate upon heating. More specifically, it is as follows. In the past, it was originally difficult to industrially produce such a very thin polarizer, but recently it has become possible to industrially produce such a very thin polarizer. In such a very thin polarizer, both the optical characteristics and the durability were initially insufficient when it became possible to manufacture. As a result of trial and error in order to solve such a problem, it has been found out that a polarizer excellent in optical characteristics and durability can be obtained by making the content of boric acid and the content of iodine of the polarizer higher than that of a conventional polarizer of a thicker type I could. Further, by setting the content of boric acid and the content of iodine in the polarizer in the above-described range in a thin polarizing plate with a retardation layer with a difference in thickness and thickness optimized, it is possible to maintain the ease of curling at the time of curing well, It was found that while the curl of the hour was well suppressed, it was possible to prevent streaks from streaking and improve the appearance durability at the time of heating. This effect is an unexpected and excellent effect in the knowledge obtained by applying the boric acid content and the iodine content to the polarizer of the polarizing plate with a retardation layer having such a specific structure.

The polarizer preferably exhibits absorption dichroism at a wavelength of 380 nm to 780 nm. The transmittance of the polarizer is 44.0% to 45.5%, preferably 44.5% to 45.0%, as described above. If the single transmittance of the polarizing plate with a thin film of the retardation layer is optimized in such a range as to optimize the difference in thickness and thickness of a predetermined layer, the synergistic effect of optimizing the boric acid content and the iodine content will facilitate ease of curl adjustment Can be satisfactorily maintained, curling at the time of heating can be well suppressed, and stain unevenness can be suppressed, thereby improving the appearance durability during heating. It is estimated that there may be a critical point of occurrence of streaking stains in a slightly larger unit transmittance of 45.5%.

The degree of polarization of the polarizer is preferably 99.9% or more, more preferably 99.95% or more, and further preferably 99.98% or more. According to the present invention, it is possible to realize a thin polarizing plate with a retardation layer which is easily curled at the time of curing and curls at the time of heating, and further has excellent durability at the time of heating, The above-described excellent polarization degree can be realized.

B-2. The first protective layer

The first protective layer 12 is formed of any suitable film that can be used as a protective layer of the polarizer. Specific examples of the material constituting the main component of the film include cellulose-based resins such as triacetylcellulose (TAC), polyester-based resins, polyvinyl alcohol-based resins, polycarbonate-based resins, polyamide-based resins, polyimide- (Meth) acrylate, acetate and the like, and the like can be given as examples of the transparent resin such as polyolefin resin, polystyrene resin, polynorbornene resin, polyolefin resin, Further, thermosetting resins such as (meth) acrylic resins, urethane resins, (meth) acrylic urethane resins, epoxy resins and silicon resins, and ultraviolet curable resins may also be used. In addition, for example, glassy polymers such as siloxane-based polymers may be mentioned. A polymer film described in Japanese Patent Application Laid-Open No. 2001-343529 (WO01 / 37007) may also be used. As a material of this film, for example, a resin composition containing a thermoplastic resin having a substituted or unsubstituted imide group in a side chain and a thermoplastic resin having a phenyl group and a substituted or unsubstituted phenyl group and a nitrile group in the side chain can be used. For example, a resin composition having an alternating copolymer composed of isobutene and N-methylmaleimide and an acrylonitrile-styrene copolymer may be mentioned. The polymer film may be, for example, an extrusion molded article of the resin composition.

As described later, the polarizing plate with a retardation layer of the present invention is typically disposed on the viewer side of the image display apparatus, and the first protective layer 12 is typically disposed on the viewer side thereof. Therefore, the first protective layer 12 may be subjected to surface treatment such as hard coat treatment, antireflection treatment, anti-sticking treatment, and antiglare treatment, if necessary.

The thickness of the first protective layer may be any suitable thickness as long as the difference between the thickness of the desired polarizing plate and the thickness of the second protective layer is obtained. The thickness of the first protective layer is, for example, 20 占 퐉 to 40 占 퐉, preferably 25 占 퐉 to 35 占 퐉. When the surface treatment is carried out, the thickness of the first protective layer is the thickness including the thickness of the surface treatment layer.

B-3. The second protective layer

The second protective layer 13 is also formed of any suitable film that can be used as the protective layer of the polarizer. The material that becomes the main component of the film is as described in the above section B-2 with respect to the first protective layer. The second protective layer 13 is preferably optically isotropic. In the present specification, "optically isotropic" means that the in-plane retardation Re (550) is from 0 to 10 nm and the retardation in the thickness direction Rth (550) is from -10 nm to +10 nm.

The thickness of the second protective layer is, for example, 15 mu m to 35 mu m, preferably 20 mu m to 30 mu m. The difference between the thickness of the first protective layer and the thickness of the second protective layer is 10 μm or less, preferably 7 μm or less, as described above. When the difference in thickness is in this range, the curl at the time of curing can be satisfactorily suppressed. The thickness of the first protective layer and the thickness of the second protective layer may be the same or the first protective layer may be thick or the second protective layer may be thick. Typically, the first protective layer is thicker than the second protective layer.

B-4. Characteristics of the whole polarizing plate

The thickness of the polarizing plate (the total thickness of the polarizer, the first protective layer and the second protective layer, and the thickness of the adhesive layer for laminating them) is 80 占 퐉 or less, preferably 50 占 퐉 to 70 占 퐉, as described above. By setting the thickness of the polarizing plate to such a range in a thin polarizing plate with a retardation layer having a predetermined layer thickness and thickness and optimized the boric acid content and iodine content of the polarizer, curling during heating can be suppressed well, The curl at the time of curing can be adjusted well while maintaining the appearance durability at the time of heating.

C. retardation layer

The retardation layer 20 may be composed of a retardation film having any suitable optical and / or mechanical properties depending on the purpose. The retardation layer 20 typically has a slow axis. In one embodiment, the angle? Between the slow axis of the retardation layer 20 and the absorption axis of the polarizer 11 is preferably 38 ° to 52 °, more preferably 42 ° to 48 ° , More preferably about 45 [deg.]. When the angle [theta] is within this range, a polarizing plate with a retardation layer having a very excellent circularly polarized light characteristic (as a result, a very excellent antireflection property) can be obtained by using a retardation layer as a? / 4 plate as described later .

The retardation layer preferably exhibits a refractive index characteristic of nx > ny > nz. The retardation layer is typically formed to impart antireflection properties to the polarizing plate, and in one embodiment, it can function as a lambda / 4 plate. In this case, the in-plane retardation Re (550) of the retardation layer is preferably 80 nm to 200 nm, more preferably 100 nm to 180 nm, further preferably 110 nm to 170 nm. Here, " ny = nz " includes not only cases where ny and nz are completely equal but also cases where they are substantially equivalent. Therefore, ny < nz may be obtained within a range that does not impair the effect of the present invention.

The Nz coefficient of the retardation layer is preferably 0.9 to 3, more preferably 0.9 to 2.5, still more preferably 0.9 to 1.5, and particularly preferably 0.9 to 1.3. By satisfying such a relationship, when a polarizing plate with a retardation layer to be obtained is used in an image display apparatus, a very excellent reflection color can be achieved.

The retardation layer may exhibit a reverse dispersion wavelength characteristic in which the retardation value increases according to the wavelength of the measurement light and may exhibit a positive wavelength dispersion characteristic in which the retardation value decreases with the wavelength of the measurement light, A flat wavelength dispersion characteristic that hardly changes depending on the wavelength may be exhibited. In one embodiment, the retardation layer exhibits a reverse dispersion wavelength characteristic. In this case, Re (450) / Re (550) of the retardation layer is preferably 0.8 or more and less than 1, and more preferably 0.8 or more and 0.95 or less. With such a configuration, an excellent antireflection characteristic can be realized. In another embodiment, the retardation layer exhibits flat wavelength dispersion characteristics. In this case, Re (450) / Re (550) of the retardation layer is preferably 0.99 to 1.03, and Re (650) / Re (550) is preferably 0.98 to 1.02. In this case, the retardation layer may have a laminated structure. Specifically, by arranging a retardation film functioning as a? / 2 plate and a retardation film serving as a? / 4 plate at a predetermined axial angle (for example, 50 ° to 70 °, preferably about 60 °) It is possible to obtain characteristics close to the reverse wavelength dispersion characteristic, and as a result, it is possible to realize an excellent antireflection characteristic.

The retardation layer has an absorption rate of 3% or less, preferably 2.5% or less, and more preferably 2% or less. By satisfying such a water absorption rate, it is possible to suppress a change in display characteristic over time. The water absorption can be obtained in accordance with JIS K 7209.

Retardation layer, the absolute value of photoelastic coefficient of preferably from 2 × 10 ^-11 ㎡ / N or less, and more preferably ^{2.0 × 10 -13 ㎡ / N ~} 1.5 × 10 -11 ㎡ / N, and more preferably And a resin of 1.0 x 10 ^-12 m 2 / N to 1.2 x 10 ^-11 m 2 / N. When the absolute value of the photoelastic coefficient is in this range, the retardation change does not occur well when shrinkage stress is generated at the time of heating. As a result, heat unevenness of the obtained image display device can be prevented well.

The thickness of the retardation layer is 60 占 퐉 or less, preferably 40 占 퐉 to 55 占 퐉, as described above. By setting the thickness of the retardation layer in the thin polarizing plate with retardation layer with optimized thickness and thickness difference and the content of boric acid and iodine content of the polarizer within such a range, curling during heating can be suppressed well, The curl at the time of curing can be satisfactorily adjusted while suppressing stains and maintaining the appearance durability at the time of heating.

The difference between the thickness of the retardation layer 20 and the thickness of the polarizing plate 10 is 25 占 퐉 or less, preferably 18 占 퐉 or less, as described above. By setting the difference in the thickness in the thin polarizing plate with a retardation layer having a predetermined layer thickness and optimized for the boric acid content and iodine content of the polarizer within such a range, curling at the time of heating can be well suppressed, The curl at the time of curing can be adjusted well while maintaining the appearance durability of the cigarette. The thickness of the retardation layer and the thickness of the polarizing plate may be the same, the retardation layer may be thick, or the polarizing plate may be thick. Typically, the polarizing plate is thicker than the retardation layer.

The retardation layer 20 may be made of any suitable resin film capable of satisfying the above-described characteristics. Representative examples of such resins include, for example, cyclic olefin resins, polycarbonate resins, cellulosic resins, polyester resins, polyvinyl alcohol resins, polyamide resins, polyimide resins, polyether resins, polystyrene Based resins, and acrylic-based resins. Among them, a cyclic olefin resin or a polycarbonate resin can be preferably used.

The cyclic olefin resin is a generic name of a resin polymerized using a cyclic olefin as a polymerization unit and includes, for example, those described in JP-A-1-240517, JP-A-3-14882, 3-122137 and the like. Specific examples thereof include ring-opened (co) polymers of cyclic olefins, addition polymers of cyclic olefins, copolymers (typically, random copolymers) of cyclic olefins and? -Olefins such as ethylene and propylene, Graft-modified compounds modified with an unsaturated carboxylic acid or a derivative thereof, and hydrides thereof. Specific examples of cyclic olefins include norbornene monomers. The norbornene monomers include, for example, norbornene and its alkyl and / or alkylidene substituents such as 5-methyl-2-norbornene, 5-dimethyl- Ethyl-2-norbornene, 5-butyl-2-norbornene, and 5-ethylidene-2-norbornene; halogen-substituted polar group substituents such as dicyclopentadiene, 2,3-dihydro Dicyclopentadiene and the like; dimethanooctahydronaphthalene, its alkyl and / or alkylidene substituents, and polar substituents such as halogens such as 6-methyl-1,4: 5,8-dimethano-1 , 4,4a, 5,6,7,8,8a-octahydronaphthalene, 6-ethyl-1,4: 5,8-dimethano-1,4,4a, 5,6,7,8,8a Octahydronaphthalene, 6-ethylidene-1,4: 5,8-dimethano 1,4,4a, 5,6,7,8,8a-octahydronaphthalene, 6-chloro-1,4: 5 , 8-dimethano-1,4,4a, 5,6,7,8,8a-octahydronaphthalene, 6-cyano-1,4: 5,6,7,8,8a-octahydronaphthalene, 6-pyridyl-1,4: 5, Dimethano-1,4,4a, 5,6,7,8,8a-octahydronaphthalene, 6-methoxycarbonyl-1,4: 5,8-dimethano-1,4,4a , 5,6,7,8,8a-octahydronaphthalene, etc .; cyclic amides of cyclopentadiene such as 4,9: 5,8-dimethano-3a, 4,4a, 5,8 , 8a, 9,9a- octahydro-1H-benzoindene, 4,11: 5,10: 6,9-trimethano-3a, 4,4a, 5,5a, 6,9,9a, 10a, 11,11a- dodecahydro-1H-cyclopentanthracene, and the like.

In the present invention, other cycloolefins capable of ring-opening polymerization can be used in combination within a range not hindering the object of the present invention. Specific examples of such cycloolefins include, for example, compounds having one reactive double bond such as cyclopentene, cyclooctene, and 5,6-dihydrodicyclopentadiene.

The cyclic olefin resin preferably has a number average molecular weight (Mn) measured by a gel permeation chromatography (GPC) method using a toluene solvent of preferably 25,000 to 200,000, more preferably 30,000 to 100,000, and most preferably It is 40,000 ~ 80,000. When the number average molecular weight is within the above range, excellent mechanical strength and excellent solubility, moldability, and flexibility can be produced.

When the cyclic olefin resin is obtained by hydrogenating a ring-opening polymer of a norbornene monomer, the hydrogenation ratio is preferably 90% or more, more preferably 95% or more, and most preferably 99 %. With such a range, heat resistance and heat resistance are excellent.

A commercially available film may be used as the cyclic olefin based resin film. Specific examples thereof include trade names "Zeonex", "Zeonor" manufactured by Nippon Zeon Corporation, "Arton" manufactured by JSR Corporation, "Topaz" manufactured by TICONA Corporation, "APEL" .

The polycarbonate resin is preferably a resin composition comprising a structural unit derived from a dihydroxy compound represented by the following general formula (1), a structural unit derived from a dihydroxy compound represented by the following general formula (2) The dihydroxy compound represented by the formula (3), the dihydroxy compound represented by the following formula (4), the dihydroxy compound represented by the following formula (5) and the dihydroxy compound represented by the following formula (6) And a structural unit derived from at least one dihydroxy compound selected from the group consisting of

[Chemical Formula 1]

(1), R ₁ to R ₄ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 6 to 20 carbon atoms, Substituted or unsubstituted aryl group having 6 to 20 carbon atoms, and X is a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms, a substituted or unsubstituted cycloalkylene group having 6 to 20 carbon atoms, And m and n are each independently an integer of 0 to 5).

(2)

(3)

(In the above general formula (3), R ₅ represents a cycloalkylene group having a monocyclic structure of a substituted or unsubstituted monocyclic structure having 4 to 20 carbon atoms)

[Chemical Formula 4]

(In the general formula (4), R ₆ represents a substituted or unsubstituted monocyclic cycloalkylene group having 4 to 20 carbon atoms)

[Chemical Formula 5]

(In the general formula (5), R ₇ represents a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms, and p is an integer of 2 to 100)

[Chemical Formula 6]

(In the general formula (6), R ₁₁ represents an alkyl group having 2 to 20 carbon atoms or a group represented by the following formula (7)

(7)

<Dihydroxy compound represented by the above general formula (1)

Specific examples of the dihydroxy compound represented by the above general formula (1) include 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxy- (4-hydroxy-3-ethylphenyl) fluorene, 9,9-bis (4-hydroxy- Bis (4-hydroxy-3-isopropylphenyl) fluorene, 9,9-bis (4-hydroxy-3-cyclohexylphenyl) fluorene, 9,9-bis (4-hydroxy- (4-hydroxyphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene, 9,9- (3-methylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) ) -3-isobutylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3-cyclohexylphenyl) fluorene, 9,9-bis (4- (4- (2-hydroxyethoxy) -3,5-dimethylphenyl) fluorene, 9,9-bis 9,9-bis (4- (3-hydroxy-2,2-dimethylpropyl) -3-tert- (4-hydroxy-3-methylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) phenyl Fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3-methylphenyl) fluorene, Phenyl) fluorene.

&Lt; Dihydroxy compound represented by the above general formula (2)

Examples of the dihydroxy compound represented by the general formula (2) include isosorbide, isomannide, and isoidide in the relation of stereoisomers. These may be used singly or in combination of two or more kinds. Among these dihydroxy compounds, isosorbide which is obtained by dehydration condensation of sorbitol which is abundantly present as a resource and which is produced from various starches which are easily available is most preferable in view of easiness to obtain and manufacture, optical property and moldability Do.

<Dihydroxy compound represented by the above general formula (3)

Examples of the dihydroxy compound represented by the general formula (3) include a compound containing a cycloalkylene group having a monocyclic structure (alicyclic dihydroxy compound). By employing a monolithic structure, it is possible to improve the toughness when the obtained polycarbonate resin is used as a film. Typical examples of the alicyclic dihydroxy compound include compounds containing a five-membered ring structure or a six-membered ring structure. 5-atom cyclic structure or 6-atom cyclic structure, the heat resistance of the obtained polycarbonate resin can be increased. The 6-membered ring structure may be fixed to the chair type or the boat type by covalent bonding. Specific examples include 1,2-cyclopentanediol, 1,3-cyclopentanediol, 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 4-cyclohexanediol, and the like. The dihydroxy compounds represented by the general formula (3) may be used alone or in combination of two or more.

<Dihydroxy compound represented by the above general formula (4)

Examples of the dihydroxy compound represented by the general formula (4) include a compound containing a cycloalkylene group having a monocyclic structure (an alicyclic dihydroxy compound). By employing a monolithic structure, it is possible to improve the toughness when the obtained polycarbonate resin is used as a film. As a typical example of the alicyclic dihydroxy compound, R ₆ in the general formula (4) is a group represented by the following general formula (Ia): wherein R ³ represents a hydrogen atom or a substituted or unsubstituted C1- An alkyl group having 1 to 12 carbon atoms). Specific preferred examples of such isomers include 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, and 1,4-cyclohexanedimethanol. They are easy to obtain and have excellent handling properties. The dihydroxy compounds represented by the general formula (4) may be used alone or in combination of two or more.

[Chemical Formula 8]

The compounds exemplified above with respect to the dihydroxy compounds represented by the general formulas (3) and (4) are examples of the alicyclic dihydroxy compounds which can be used, but are not limited thereto at all.

&Lt; Dihydroxy compound represented by the above general formula (5)

Specific examples of the dihydroxy compound represented by the general formula (5) include diethylene glycol, triethylene glycol, polyethylene glycol (molecular weight: 150 to 2000), and the like.

&Lt; Dihydroxy compound represented by the above general formula (6)

Specific examples of the dihydroxy compound represented by the general formula (6) include ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, or spiroglycols represented by the following formula (8) Among them, propylene glycol, 1,4-butanediol and spiroglycol are preferable.

[Chemical Formula 9]

A structural unit derived from a dihydroxy compound represented by the general formula (3), a structural unit derived from a dihydroxy compound represented by the general formula (4), and a structural unit derived from a dihydroxy compound represented by the general formula (5) Of the structural unit derived from the dihydroxy compound represented by the general formula (4) and / or the structural unit derived from the dihydroxy compound represented by the general formula (5) among the structural units derived from the dihydroxy compound represented by the general formula (6) Containing structural unit derived from a dihydroxy compound represented by the general formula (5), and more preferably contains a structural unit derived from a dihydroxy compound represented by the general formula (5). By containing the structural unit derived from the dihydroxy compound represented by the above general formula (5), the improvement of the stretchability is promoted.

The polycarbonate resin of the present embodiment may further contain a structural unit derived from another dihydroxy compound.

&Lt; Other dihydroxy compound >

Other dihydroxy compounds include, for example, bisphenols and the like. Examples of bisphenols include 2,2-bis (4-hydroxyphenyl) propane [= bisphenol A], 2,2-bis (4-hydroxy- Propane, 2,2-bis (4-hydroxy-3,5-diethylphenyl) propane, Bis (4-hydroxyphenyl) pentane, 2,4'-dihydroxy-diphenylmethane, bis (4-hydroxyphenyl) , Bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 3,3- (4-hydroxyphenyl) sulfone, 2,4'-dihydroxydiphenyl sulfone, bis (4-hydroxyphenyl) sulfide, 4,4'-dihydroxy Phenyl ether, 4,4'-dihydroxy-3,3'-dichlorodiphenyl ether, and 4,4'-dihydroxy-2,5-diethoxydiphenyl ether.

In the polycarbonate resin, the structural unit derived from the dihydroxy compound represented by the general formula (1) is at least 18 mol%, preferably at least 20 mol%, more preferably at least 25 mol%. If the structural unit is excessively small, the wavelength dependency of the reverse dispersion may not be obtained.

The dihydroxy compound represented by the general formula (3), the dihydroxy compound represented by the general formula (4), the dihydroxy compound represented by the general formula (5), and the dihydroxy compound represented by the general formula (6) Is preferably 25 mol% or more, more preferably 30 mol% or more, still more preferably 35 mol% or more in the above polycarbonate resin, Or more. If the structural units are excessively small, the toughness may be insufficient when formed into a film.

The glass transition temperature of the polycarbonate resin is preferably from 110 캜 to 150 캜, and more preferably from 120 캜 to 140 캜. If the glass transition temperature is excessively low, the heat resistance tends to deteriorate, and there is a possibility of causing a dimensional change after film formation, and furthermore, the image quality of the obtained organic EL panel may be lowered. If the glass transition temperature is excessively high, the molding stability at the time of film forming may deteriorate, and transparency of the film may be deteriorated. The glass transition temperature is determined in accordance with JIS K 7121 (1987).

The molecular weight of the polycarbonate resin can be represented by the reduced viscosity. The reduced viscosity was measured using a Ureterde viscosity tube at a temperature of 20.0 DEG C +/- 0.1 DEG C by precisely adjusting the polycarbonate concentration to 0.6 g / dL using methylene chloride as a solvent. The lower limit of the reduced viscosity is usually 0.30 dL / g, more preferably 0.35 dL / g or more. The upper limit of the reduced viscosity is usually 1.20 dL / g, more preferably 1.00 dL / g, and still more preferably 0.80 dL / g. If the reduced viscosity is lower than the above lower limit value, the mechanical strength of the molded article may be decreased. On the other hand, if the reduced viscosity is larger than the upper limit value, there is a case that the fluidity at the time of molding is lowered and the productivity and formability are lowered.

A commercially available film may be used as the polycarbonate-based resin film. Specific examples of commercially available products include trade names "Pure Ace WR-S", "Pure Ace WR-W", "Pure Ace WR-M" and trade name "NRF" manufactured by Nitto Denko Corporation.

The retardation layer 20 is obtained, for example, by stretching a film formed from the cyclic olefin resin or the polycarbonate resin. As a method of forming a film from a cyclic olefin resin or a polycarbonate resin, any suitable molding process may be employed. Specific examples thereof include compression molding, transfer molding, injection molding, extrusion molding, blow molding, powder molding, FRP molding, cast coating (e.g., casting) Extrusion molding method or cast coating method is preferable. This is because the smoothness of the obtained film can be enhanced and favorable optical uniformity can be obtained. The molding conditions can be appropriately set according to the composition and kind of the resin to be used, the desired properties of the retardation layer, and the like. As described above, since many film products are commercially available in the cyclic olefin-based resin and the polycarbonate-based resin, the commercially available film may be directly provided in the stretching treatment.

The thickness of the resin film (unstretched film) can be set to any appropriate value depending on the desired thickness of the retardation film, desired optical properties, stretching conditions to be described later, and the like. And preferably from 50 mu m to 300 mu m.

The stretching may be carried out by any appropriate stretching method, stretching conditions (for example, stretching temperature, stretching magnification, stretching direction). Specifically, various stretching methods such as free-standing elongation, fixed-end elongation, free-end shrinkage, and fixed-end shrinkage can be used alone, or simultaneously or sequentially. The stretching direction can also be performed in various directions and dimensions such as the longitudinal direction, the width direction, the thickness direction, and the oblique direction. The stretching temperature is preferably Tg - 30 ° C to Tg + 60 ° C, more preferably Tg - 10 ° C to Tg + 50 ° C, relative to the glass transition temperature (Tg) of the resin film.

By appropriately selecting the stretching method and stretching conditions, a retardation film having the desired optical properties (for example, refractive index characteristics, in-plane retardation, and Nz coefficient) can be obtained.

In one embodiment, the retardation film is produced by uniaxially stretching or uniaxially stretching the resin film. As a specific example of the monolayer uniaxial stretching, there is a method of stretching in the transverse direction (transverse direction) while running the resin film in the longitudinal direction. The draw ratio is preferably 1.1 to 3.5 times.

In another embodiment, the retardation film can be produced by continuously tilting the elongated resin film in the direction of the angle? With respect to the longitudinal direction. By employing the tilted stretching, a elongated stretched film having an orientation angle (a slow axis in the direction of the angle?) With respect to the longitudinal direction of the film is obtained. For example, in the lamination with a polarizer It is possible to roll-to-roll, and the manufacturing process can be simplified. The angle? May be an angle formed by the absorption axis of the polarizer and the slow axis of the retardation layer in the polarizing plate with a retardation layer. As described above, the angle? Is preferably 38 ° to 52 °, more preferably 42 ° to 48 °, and still more preferably about 45 °.

Examples of the stretching machine used for the tensional stretching include a tenter stretcher capable of imparting a feed force or a pulling force or a pulling force at right and left different speeds in the transverse and / or longitudinal direction. Examples of the tenter-type stretching machine include a transverse uniaxial stretching machine and a simultaneous biaxial stretching machine. Any suitable stretching machine can be used as long as a longitudinally stretched resin film can be continuously tilted and stretched.

By properly controlling the left and right velocities in the stretcher, a retardation layer (substantially a long-axis phase retardation film) having the desired in-plane retardation and having a retardation axis in the desired direction can be obtained.

The stretching temperature of the film may vary depending on the desired in-plane retardation value and thickness of the retardation layer, the type of resin used, the thickness of the film to be used, the stretching magnification, and the like. Specifically, the stretching temperature is preferably Tg - 30 ° C to Tg + 30 ° C, more preferably Tg - 15 ° C to Tg + 15 ° C, and most preferably Tg - 10 ° C to Tg + 10 ° C. By stretching at such a temperature, a retardation layer having suitable properties in the present invention can be obtained. Tg is the glass transition temperature of the constituent material of the film.

D. Other

The polarizing plate with a retardation layer according to the embodiment of the present invention may further include another retardation layer. The optical properties (for example, refractive index characteristics, in-plane retardation, Nz coefficient, photoelastic coefficient), thickness, arrangement position and the like of other retardation layers can be appropriately set according to the purpose.

Any suitable pressure-sensitive adhesive layer or adhesive layer is used for the lamination of the layers constituting the polarizing plate with a retardation layer of the present invention. The pressure-sensitive adhesive layer is typically formed of an acrylic pressure-sensitive adhesive. The adhesive layer is typically formed of a polyvinyl alcohol-based adhesive.

Although not shown, a pressure-sensitive adhesive layer may be formed on the surface of the retardation layer 20 of the polarizing plate with a retardation layer (in the case where another retardation layer is formed, the surface of the outermost retardation layer). Since the pressure-sensitive adhesive layer is formed in advance, it can be easily attached to other optical members or image display devices. It is preferable that a release film is adhered to the surface of the pressure-sensitive adhesive layer until it is provided for use.

E. Image display

The polarizing plate with a retardation layer described in the above items A to C can be applied to an image display apparatus. Therefore, the present invention includes an image display apparatus using such a polarizing plate with a retardation layer. Typical examples of the image display apparatus include a liquid crystal display apparatus and an organic EL display apparatus. The image display apparatus according to the embodiment of the present invention has the polarizing plate with a retardation layer described in the items A to C above on its viewing side. The polarizing plate with a retardation layer is laminated such that the retardation layer is on the display panel (for example, liquid crystal panel, organic EL panel) side (polarizer is on the viewer side).

Example

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to these Examples. The measurement method of each characteristic is as follows.

(1) Thickness

And measurement was performed using a digital micrometer (KC-351C manufactured by Anritsu).

(2) The unit transmittance of the polarizer

With respect to the polarizing plates used in Examples and Comparative Examples, the ultraviolet visible spectrophotometer (V7100 manufactured by Nihon Spectroscope, Ltd.) was used to measure a simple transmittance of the polarizer. Here, the transmittance is a Y value obtained by performing visibility correction by measuring with a 2-degree field of view (C light source) of JIS Z 8701.

(3) Boric acid content of polarizer

The polarizers used in Examples and Comparative Examples were heated and dried (at 120 DEG C for 2 hours) and then pulverized to obtain an evaluation sample having a weight of 1 g. 1 g of the sample for evaluation was dissolved in 500 ml of water at 95 캜. 10 g of mannitol and 2 ml of bromothymol blue solution (BTB solution) were added to the obtained aqueous solution to prepare a sample solution. To this sample solution, 0.1 mol / l of sodium hydroxide was dropped until a neutralization point was reached, and the boric acid content ratio (% by weight) was calculated from the drop amount based on the following equation.

(4) iodine content of polarizer

The polarizers used in Examples and Comparative Examples were cut into a predetermined size and used as samples for evaluation. The iodine concentration of the sample for evaluation was determined by the calibration curve method of fluorescent X-ray analysis. The apparatus used was a fluorescent X-ray analyzer ZSX of Rigaku Co., Ltd.

(5) the retardation value of the retardation layer and the Nz coefficient

Samples of 50 mm x 50 mm were cut out from the retardation layer used in Examples and Comparative Examples to obtain measurement samples. The measured samples were measured for in-plane retardation and thickness retardation using Axoscan manufactured by Axometrics. The measurement wavelength of the in-plane retardation was 450 nm and 550 nm, the measurement wavelength of the retardation in the thickness direction was 550 nm, and the measurement temperature was 23 占 폚. The Nz coefficient was calculated from the in-plane retardation and thickness direction retardation obtained.

(6) Curl adjustment in concert

With respect to the fusion of the polarizing plate and the retardation layer, the tension on the polarizing plate side and the tension on the retardation layer side at the time of curing were made the same, and the curled state of the laminated film cut out into a size of 100 mm x 100 mm was confirmed.

Easy to adjust (good): Curl amount less than 10 mm

Difficult to adjust (unsuitable): Curl amount exceeds 10 mm

(7) curling during heating

The polarizing plate with a retardation layer obtained in Examples and Comparative Examples was cut into a size of 100 mm x 100 mm and stored in a heating oven at 85 캜 for 30 minutes and taken out to confirm the state of curl in a state in which the release film was peeled off. The evaluation criteria are as follows.

Permissible range: Curl amount less than 10 mm

Non-conforming: curl exceeded 10 mm

(8) Appearance durability during heating

The cover glass and the antireflection film on the surface side of a smartphone (product name " Galaxy-S5 ") manufactured by Samsung Electronics Japan Co., Ltd. were peeled off and the polarizing plate with a retardation layer obtained in Examples and Comparative Examples was peeled off with an acrylic pressure- 15 mu m) was used as a sample for evaluation. The sample for evaluation was stored in an oven at 85 캜 for 240 hours, taken out, and its appearance was visually confirmed. The evaluation criteria are as follows.

Good: no streaks on the stripe were observed

Bad: Streaked stain is visible

[Reference Example 1: Production of Polarizer]

A long roll of a polyvinyl alcohol (PVA) based resin film (product name "PE3000", manufactured by Kuraray Co., Ltd.) having a thickness of 30 탆 was uniaxially stretched in the longitudinal direction to 5.9 times in the longitudinal direction by a roll stretching machine, Crosslinking and washing treatment were carried out, and finally a drying treatment was carried out to prepare Polarizer 1 having a thickness of 12 탆.

Specifically, the swelling treatment was conducted at a stretching ratio of 2.2 times while being treated with pure water at 20 占 폚. Then, in the dyeing treatment, the film was stretched to 1.4 times while being treated in an aqueous solution of 30 DEG C at a weight ratio of iodine and potassium iodide adjusted to an iodine concentration of 1: 7 such that the ultraviolet transmittance of the resulting polarizer was 45.0%. In the crosslinking treatment, a two-stage crosslinking treatment was employed, and in the first-stage crosslinking treatment, the solution was stretched 1.2 times while being treated in an aqueous solution of boric acid and potassium iodide dissolved at 40 占 폚. The content of boric acid in the aqueous solution of the crosslinking treatment in the first step was 5.0 wt%, and the content of potassium iodide was 3.0 wt%. The crosslinking treatment in the second step was carried out in an aqueous solution of boric acid and potassium iodide dissolved at 65 DEG C while being stretched to 1.6 times. The content of boric acid in the aqueous solution of the crosslinking treatment in the second step was 4.3% by weight, and the content of potassium iodide was 5.0% by weight. The cleaning treatment was performed with an aqueous solution of potassium iodide at 20 占 폚. The potassium iodide content in the aqueous solution for the washing treatment was 2.6 wt%. Finally, the drying treatment was conducted at 70 캜 for 5 minutes to obtain Polarizer 1.

A TAC film (product name: KC2UA, thickness: 25 占 퐉, corresponding to the second protective layer) manufactured by Konica Minolta Co., Ltd. was applied to both surfaces of the obtained polarizer 1 via a polyvinyl alcohol adhesive agent and a hard coat treatment A HC-TAC film (thickness: 32 탆, having a hard coat (HC) layer formed thereon) was adhered to each of the first protective layer / polarizer 1 / second protective layer 1.

[Reference Example 2: Production of polarizing plate]

A long roll of a polyvinyl alcohol (PVA) based resin film (manufactured by Kuraray Co., Ltd., product name " PE2000 ") having a thickness of 20 탆 was used and the iodine concentration of the dyeing solution was adjusted so that the polarizing element had a single light transmittance of 44.5% And Polarizer 2 having a thickness of 8 탆 was obtained in the same manner as in Reference Example 1 except that the stretching magnification in the second stage crosslinking treatment was 1.5 times. Polarizer 2 having the structure of first protective layer / polarizer 2 / second protective layer was obtained in the same manner as in Reference Example 1 except that Polarizer 2 was used.

[Reference Example 3: Production of polarizing plate]

Polarizer 3 having a thickness of 23 占 퐉 was obtained in the same manner as in Reference Example 1 except that a long roll of a polyvinyl alcohol (PVA) based resin film (manufactured by Kuraray Co., Ltd., product name: " PE6000 ") having a thickness of 60 占 퐉 was used.

An HC-TAC film (thickness: 46 占 퐉, thickness: 20 占 퐉) having an HC layer formed on one side of a TAC film (product name: KC4UY) manufactured by Konica Minolta Co., Ltd. by HC treatment was applied to both surfaces of the obtained polarizer 3 via a polyvinyl alcohol- (Corresponding to the first protective layer) and an acrylic film (thickness: 20 탆, corresponding to the second protective layer) were laminated to obtain the polarizing plate 3 having the configuration of the first protective layer / polarizer 3 / second protective layer.

[Reference Example 4: Preparation of polarizer]

On both sides of the polarizer 3 obtained in Reference Example 3, a TAC film (product name: KC2UA thickness: 25 mu m, corresponding to the second protective layer) of Konica Minolta Co., Ltd. and a side surface of the TAC film produced by Konica Minolta Co., HC-TAC film (having a thickness of 32 탆, corresponding to the first protective layer) having an HC layer formed by the HC treatment was laminated to obtain a polarizing plate 4 having the configuration of the first protective layer / polarizer 3 / second protective layer .

[Reference Example 5: Production of polarizing plate]

Polarizer 5 was prepared in the same manner as in Reference Example 1 except that the iodine concentration of the dye solution was adjusted so that the mass transmittance of the polarizer was 45.6%. A polarizing plate 5 having the configuration of the first protective layer / polarizer 5 / second protective layer was obtained in the same manner as in Reference Example 1 except that the polarizer 5 was used.

[Reference Example 6: Production of polarizing plate]

Polarizer 6 was prepared in the same manner as in Reference Example 1 except that the boric acid content in the aqueous solution of the second crosslinking treatment was 3.0% by weight. A polarizing plate 6 having the configuration of the first protective layer / polarizer 6 / second protective layer was obtained in the same manner as in Reference Example 1 except that the polarizer 6 was used.

[Reference Example 7: Preparation of retardation film constituting retardation layer]

7-1. Production of polycarbonate resin film

26.5 parts by mass of isosorbide (ISB), 100.5 parts by mass of 9,9- [4- (2-hydroxyethoxy) phenyl] fluorene (BHEPF), 1,4-cyclohexanedimethanol ), 105.1 parts by mass of diphenyl carbonate (DPC), and 0.591 part by mass of cesium carbonate (0.2 mass% aqueous solution) as a catalyst were charged into a reaction vessel, respectively, and under nitrogen atmosphere, as the first step of the reaction, The temperature of the reaction vessel was adjusted to 150 캜, and the raw material was dissolved while stirring as required (about 15 minutes).

Subsequently, the pressure in the reaction vessel was changed from the atmospheric pressure to 13.3 ㎪, and the temperature of the reaction vessel was raised to 190 캜 for 1 hour, and the resulting phenol was taken out of the reaction vessel.

After the temperature in the reaction vessel was maintained at 190 캜 for 15 minutes, the pressure in the reaction vessel was set to 6.67 으로서, and the temperature of the reaction vessel was elevated to 230 캜 for 15 minutes. Was taken out of the reaction vessel. The stirring torque of the stirrer was raised. Therefore, the temperature was raised to 250 DEG C for 8 minutes, and the pressure in the reaction vessel was reduced to 0.200 mPa or lower in order to remove the additional phenol. After reaching a predetermined stirring torque, the reaction was terminated, and the resulting reaction product was extruded into water and pelletized to obtain 47.4 mol% / 37.1 mol% / 15.5 mol% of BHEPF / ISB / 1,4- Of a polycarbonate resin.

The obtained polycarbonate resin had a glass transition temperature of 136.6 占 폚 and a reduced viscosity of 0.395 dL / g.

The polycarbonate resin thus obtained was vacuum-dried at 80 占 폚 for 5 hours and then dried in a single screw extruder (manufactured by Isuzu Chemical Co., screw diameter 25 mm, cylinder set temperature 220 占 폚), T die (width 200 mm, set temperature 220 占 폚) A polycarbonate resin film having a thickness of 120 占 퐉 was produced using a film forming apparatus equipped with a stirrer, a stirrer, a stirrer, a stirrer, a stirrer, a stirrer,

7-2. Production of retardation film

Using the tenter stretcher, the resultant polycarbonate resin film was transversely stretched to obtain a retardation film having a thickness of 50 占 퐉. At that time, the stretching magnification was 250%, and the stretching temperature was set to 137 to 139 캜.

Re (550) of the obtained retardation film was 137 to 147 nm, Re (450) / Re (550) was 0.89, Nz coefficient was 1.21, and the orientation angle (direction of the slow axis) was 90 degrees with respect to the long axis direction. This retardation film was used as the retardation layer 1.

[Reference Example 8: retardation film constituting retardation layer]

A commercially available cycloolefin-based retardation film (product name "ZeonoAfilm" manufactured by Nippon Zeon Co., Ltd., thickness: 47 μm, Re (550) = 140 μm) was used as the retardation layer 2.

[Reference Example 9: Production of retardation film constituting retardation layer]

(Trade name: KUZ-Film # 270, thickness: 33 μm, Re (550) = 270 nm) manufactured by Kaneka Corporation and a cycloolefin-based retardation film B KUZ-film # 140, thickness: 28 占 퐉, Re (550) = 140 nm) were laminated via an acrylic adhesive layer having a thickness of 5 占 퐉 so that the angle formed by the respective slow axes was 60 占 폚, . This laminated retardation film was used as the retardation layer 3.

[Example 1]

The second protective layer of the polarizing plate 1 and the retardation layer 1 were bonded to each other via an acrylic adhesive layer having a thickness of 12 占 퐉 so that the absorption axis of the polarizer and the retardation axis of the retardation layer form an angle of 45 占 to obtain a retardation film- . The obtained polarizing plate 1 with a retardation layer was provided for the evaluation of (6) to (8). The results are shown in Table 1.

[Example 2]

A polarizing plate 2 with a retardation layer was obtained in the same manner as in Example 1 except that the polarizing plate 2 was used. The obtained polarizing plate 2 with a retardation layer was provided for the evaluation of (6) to (8). The results are shown in Table 1.

[Example 3]

A polarizing plate 3 with a retardation layer was obtained in the same manner as in Example 1 except that the retardation layer 2 was used. The obtained polarizing plate 3 with a retardation layer was provided for the evaluation of (6) to (8). The results are shown in Table 1.

[Comparative Example 1]

The angle formed by the absorption axis of the polarizer and the slow axis of the retardation film A is 15 ° and the angle between the absorption axis of the polarizer and the retardation axis of the retardation film B is And a polarizing plate 4 with a retardation layer was obtained by interposing an acrylic adhesive layer having a thickness of 12 탆 therebetween. The resulting polarizing plate 4 with a retardation layer was provided for the evaluation of (6) to (8). The results are shown in Table 1.

[Comparative Example 2]

A polarizing plate 5 with a retardation layer was obtained in the same manner as in Example 1 except that the polarizing plate 3 was used. The obtained polarizing plate 5 with a retardation layer was provided for the evaluation of (6) to (8). The results are shown in Table 1.

[Comparative Example 3]

A polarizing plate 6 with a retardation layer was obtained in the same manner as in Comparative Example 1 except that the polarizing plate 4 was used. The resulting polarizing plate 6 with a retardation layer was provided for the evaluation of (6) to (8). The results are shown in Table 1.

[Comparative Example 4]

A polarizing plate 7 with a retardation layer was obtained in the same manner as in Example 1 except that the polarizing plate 5 was used. The obtained polarizing plate 7 with a retardation layer was provided for the evaluation of (6) to (8). The results are shown in Table 1. Further, a photographic image showing the appearance after the heat resistance test is shown in Fig.

[Comparative Example 5]

A polarizing plate 8 with a retardation layer was obtained in the same manner as in Example 1 except that the polarizing plate 6 was used. The resulting polarizing plate with a retardation layer 8 was provided for the evaluation of (6) to (8). The results are shown in Table 1.

As is evident from Table 1, the polarizing plate with a retardation layer according to the example of the present invention had good results in ease of curl adjustment at the time of curing, curling at the time of heating, and appearance durability at the time of heating. On the other hand, in the polarizing plate with a retardation layer of the comparative example, at least one of such evaluation characteristics was insufficient. That is, according to the present invention, it is found that a thin polarizing plate with a retardation layer satisfying all the above three evaluation characteristics, which is difficult in the prior art, can be obtained by optimizing predetermined requirements of the polarizing plate and the retardation layer constituting the polarizing plate with a retardation layer have.

The polarizing plate with a retardation layer of the present invention is preferably used for an image display apparatus such as a liquid crystal display apparatus and an organic EL display apparatus.

10: polarizer
11: Polarizer
12: first protective layer
13: second protective layer
20: retardation layer
100: Polarizer with retardation layer

Claims

A polarizer and a retardation layer including a first protective layer, a polarizer and a second protective layer,
The thickness of the polarizing plate is 80 占 퐉 or less, the thickness of the retardation layer is 60 占 퐉 or less,
Wherein the difference between the thickness of the first protective layer and the thickness of the second protective layer is 10 占 퐉 or less,
The difference between the thickness of the polarizing plate and the thickness of the retardation layer is 25 占 퐉 or less,
Wherein the thickness of the polarizer is 12 占 퐉 or less, the content of boric acid is 18 wt% to 25 wt%, the content of iodine is 2.1 wt% to 3.5 wt%, and the transmittance of the single crystal is 44.0% to 45.5%.

The method according to claim 1,
Wherein the retardation layer is composed of a resin film selected from a cyclic olefin based resin film and a polycarbonate based resin film.

The method according to claim 1,
And the retardation layer functions as a lambda / 4 plate.

An image display device comprising the polarizing plate with a retardation layer according to any one of claims 1 to 3.