KR20220124150A - Polarizing plate with retardation layer and image display device using same - Google Patents

Abstract

Provided is a thin polarizing plate with a retardation layer capable of suppressing corrosion of a metal member when applied to an image display device. The polarizing plate with a retardation layer of this invention contains the polarizing plate containing a polarizer, a retardation layer, and an adhesive layer in this order from the visual recognition side. The retardation layer is an alignment-solidified layer of a liquid crystal compound having a circularly polarizing function or an elliptically polarizing function. In a polarizing plate with a retardation layer, an iodine permeation suppressing layer, which is a solid or thermosetting material of a coating film of an organic solvent solution of a resin, is provided between the polarizer and the pressure-sensitive adhesive layer, and the glass transition temperature of the resin constituting the iodine permeation suppressing layer is 85°C or higher , and the weight average molecular weight (Mw) is 25000 or more.

Description

Polarizing plate with retardation layer and image display device using same

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

BACKGROUND ART In recent years, an image display device typified by a liquid crystal display device and an electroluminescent (EL) display device (eg, an organic EL display device, an inorganic EL display device) has spread rapidly. A polarizing plate and a retardation plate are typically used for an image display apparatus. Practically, a polarizing plate with a retardation layer in which a polarizing plate and a retardation plate are integrated is widely used (for example, Patent Document 1). this is getting stronger For the purpose of thinning a polarizing plate with a retardation layer, thinning (or omitting) of the protective layer of a polarizer with a large contribution to thickness and thinning of retardation film are progressing. However, when a thin polarizing plate with a retardation layer is applied to an image display apparatus, the metal member (for example, an electrode, a sensor, wiring, a metal layer) of an image display apparatus may corrode. Corrosion of such a metal member is remarkable in a high-temperature, high-humidity environment.

Japanese Patent Publication No. 3325560

The present invention has been made in order to solve the above conventional problems, and its main object is to provide a thin polarizing plate with a retardation layer capable of suppressing corrosion of a metal member when applied to an image display device.

The polarizing plate with a retardation layer of the present invention includes a polarizing plate including a polarizer, a retardation layer and an adhesive layer in this order from the visual side, and the retardation layer is an alignment-solidified layer of a liquid crystal compound having a circularly polarizing function or an elliptically polarizing function . In a polarizing plate with a retardation layer, an iodine permeation suppressing layer, which is a solid or thermosetting material of a coating film of an organic solvent solution of a resin, is provided between the polarizer and the pressure-sensitive adhesive layer, and the glass of the resin constituting the iodine permeation suppressing layer The transition temperature is 85°C or higher, and the weight average molecular weight (Mw) is 25000 or higher.

In one embodiment, the said iodine permeation suppression layer is provided between the said polarizer and the said retardation layer. In another embodiment, the iodine permeation suppressing layer is provided between the retardation layer and the pressure-sensitive adhesive layer.

In one embodiment, two or more layers of the said iodine permeation suppression layer are provided between the said polarizer and the said adhesive layer.

In one embodiment, the thickness of the said iodine permeation suppression layer is 0.05 micrometer - 10 micrometers.

In one embodiment, the glass transition temperature of the resin constituting the iodine permeation inhibiting layer is 90°C or higher.

In one embodiment, the resin constituting the iodine permeation inhibiting layer is a monomer mixture comprising more than 50 parts by weight of a (meth)acrylic monomer and more than 0 parts by weight and less than 50 parts by weight of a monomer represented by Formula (1). copolymers obtained by polymerizing:

(Wherein, X is at least 1 selected from the group consisting of a vinyl group, a (meth)acryl group, a styryl group, a (meth)acrylamide group, a vinyl ether group, an epoxy group, an oxetane group, a hydroxyl group, an amino group, an aldehyde group, and a carboxy group represents a functional group including a reactive group of a species, and R ¹ and R ² each independently represent a hydrogen atom, an aliphatic hydrocarbon group which may have a substituent, an aryl group which may have a substituent, or a heterocyclic group which may have a substituent , R ¹ and R ² may be linked to each other to form a ring).

In one embodiment, the retardation layer is a single layer, Re (550) of the retardation layer is 100 nm to 190 nm, and the angle between the slow axis of the retardation layer and the absorption axis of the polarizer is 40 ° to 50 ° .

In one embodiment, the retardation layer has a laminated structure of an alignment-solidified layer of a first liquid crystal compound and an alignment-solidified layer of a second liquid crystal compound; Re (550) of the alignment-solidified layer of the first liquid crystal compound is 200 nm to 300 nm, and the angle between its slow axis and the absorption axis of the polarizer is 10° to 20°; Re (550) of the alignment-solidified layer of the second liquid crystal compound is 100 nm to 190 nm, and the angle between the slow axis and the absorption axis of the polarizer is 70° to 80°.

In one embodiment, the said polarizing plate with a retardation layer further contains another retardation layer between the said retardation layer and the said adhesive layer, The refractive index characteristic of this other retardation layer shows the relationship of nz>nx=ny.

In one embodiment, the said polarizing plate with a retardation layer further contains the isotropic base material with a conductive layer or a conductive layer between the said iodine permeation suppression layer and the said adhesive layer.

In one embodiment, the total thickness of the said polarizing plate with a retardation layer is 60 micrometers or less.

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

In one embodiment, the said image display apparatus is an organic electroluminescent display apparatus or an inorganic electroluminescent display apparatus.

According to an embodiment of the present invention, by providing a specific iodine permeation suppressing layer at a predetermined position of a thin polarizing plate with a retardation layer, corrosion of a metal member can be suppressed when the polarizing plate with a retardation layer is applied to an image display device. have. The iodine permeation suppressing layer that can be used in the embodiment of the present invention is a solidified product or a thermosetting product of a coating film of an organic solvent solution of a resin, and the glass transition temperature of the resin constituting the iodine permeation suppressing layer is 85° C. or higher, Moreover, the weight average molecular weight (Mw) is 25000 or more.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic sectional drawing of the polarizing plate with retardation layer which concerns on one Embodiment of this invention.
1B is a schematic cross-sectional view of a polarizing plate with a retardation layer according to another embodiment of the present invention.
Fig. 2 is a schematic cross-sectional view of a polarizing plate with a retardation layer according to still another embodiment of the present invention.
Fig. 3 is a schematic cross-sectional view of a polarizing plate with a retardation layer according to still another embodiment of the present invention.
4 is a schematic cross-sectional view of a polarizing plate with a retardation layer according to still another embodiment of the present invention.
5 is a schematic cross-sectional view of a polarizing plate with a retardation layer according to still another embodiment of the present invention.

EMBODIMENT OF THE INVENTION Hereinafter, although embodiment of this invention is described, this invention is not limited to these embodiment.

(Definition of terms and symbols)

Definitions of 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 maximized (ie, the slow axis direction), 'ny' is the refractive index in the direction orthogonal to the slow axis in the plane (ie, the fast axis direction), and 'nz' is It is the refractive index in the thickness direction.

(2) In-plane phase difference (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 with light having a wavelength of 550 nm at 23°C. Re(λ) can be obtained by the formula: Re(λ)=(nx-ny)×d when the thickness of the layer (film) is d(nm).

(3) retardation in thickness direction (Rth)

'Rth(λ)' is the phase difference in the thickness direction measured with light having a wavelength of λnm at 23°C. For example, 'Rth (550)' is a phase difference in the thickness direction measured with light having a wavelength of 550 nm at 23°C. Rth(λ) can be obtained by the formula: Rth(λ)=(nx-nz)×d when the thickness of the layer (film) is d(nm).

(4) Nz coefficient

Nz coefficient can be calculated|required by Nz=Rth/Re.

(5) angle

When referring to an angle in this specification, the angle includes both clockwise and counterclockwise directions with respect to the reference direction. Thus, for example, '45°' means ±45°.

A. Overall configuration of polarizing plate with retardation layer

1A is a schematic cross-sectional view of a polarizing plate with a retardation layer according to one embodiment of the present invention; 1B is a schematic cross-sectional view of a polarizing plate with a retardation layer according to another embodiment of the present invention. The polarizing plates 100 and 101 with a retardation layer of FIGS. 1A and 1B each include the polarizing plate 10, the retardation layer 21, and the adhesive layer 30 in this order from the visual recognition side. The polarizing plate 10 typically includes a polarizer 11 and a protective layer 12 disposed on the viewer side of the polarizer 11 . Depending on the purpose, another protective layer (not shown) may be provided on the side opposite to the viewing side (protective layer 12 ) of the polarizer 11 . The retardation layer 20 is an alignment-solidified layer (hereinafter, simply referred to as a liquid-crystal alignment-solidified layer) of a liquid crystal compound having a circular polarization function or an elliptically polarization function. The pressure-sensitive adhesive layer 30 is provided as the outermost layer, and the polarizing plate with a retardation layer can be affixed to an image display device (substantially an image display cell).

In embodiment of this invention, the iodine permeation suppression layer 40 is provided between the polarizer 11 and the adhesive layer 30. The iodine permeation suppression layer 40 may be provided between the polarizer 11 and the retardation layer 20 (that is, adjacent to the polarizer 11) as shown in FIG. 1A, and as shown in FIG. 1B, the retardation You may provide between the layer 20 and the adhesive layer 30. When the iodine permeation suppression layer is provided between the polarizer and the retardation layer (especially when the iodine permeation suppression layer is adjacent to the polarizer), it is possible to suppress the migration of iodine from the polarizer in a high-temperature, high-humidity environment, and reliability is improved. There is an advantage. In the case where the iodine permeation suppressing layer is provided between the retardation layer and the pressure-sensitive adhesive layer (especially when the iodine permeation suppression layer is adjacent to the pressure-sensitive adhesive layer), a component (e.g., ultraviolet light) which is considered to affect corrosion of metals other than iodine. There is an advantage in that it is possible to simultaneously prevent migration into the adhesive with respect to the residual monomer component in the curing adhesive and the decomposition product of the photoinitiator, and the effect of inhibiting metal corrosion is further enhanced.

In a polarizing plate with a retardation layer, two or more layers of iodine permeation suppression layers may be provided between a polarizer and an adhesive layer (for example, FIG. 4 and FIG. 5). When a polarizing plate with a retardation layer has two or more layers of iodine permeation suppression layers, when a polarizing plate with a retardation layer is applied to an image display apparatus, corrosion of a metal member can be suppressed remarkably.

In the polarizing plate with retardation layer shown in FIG. 4, two iodine permeation suppression layers are provided between a polarizer and an adhesive layer. In the example shown in FIG. 4 , the iodine permeation suppressing layer is provided with two layers between the polarizer 11 and the retardation layer 20 and between the retardation layer 20 and the pressure-sensitive adhesive layer 30 . In one embodiment, the iodine permeation suppressing layer is provided adjacent to the polarizer. In another embodiment, the iodine permeation inhibiting layer is provided adjacent to the retardation layer. As used herein, “adjacent” refers to being directly laminated without interposing an adhesive layer or the like.

In the polarizing plate with a retardation layer shown in FIG. 5, three layers of iodine permeation suppression layers are provided between a polarizer and an adhesive layer. In the example shown in FIG. 5 , two layers of the iodine permeation suppression layer are provided between the polarizer 11 and the retardation layer 20 , and one layer is provided between the retardation layer 20 and the pressure-sensitive adhesive layer 30 . is provided. One of the two iodine permeation suppressing layers between the polarizer 11 and the retardation layer 20 is provided adjacent to the polarizer, and the other is provided adjacent to the retardation layer.

In the polarizing plate with a retardation layer, 4 or more layers (for example, 4 layers, 5 layers, 6 layers) may be sufficient as an iodine permeation suppressing layer. The metal corrosion inhibitory effect can be heightened, so that there are many iodine permeation suppression layers. The number of iodine permeation suppressing layers may be set in consideration of cost, manufacturing efficiency, the total thickness of the polarizing plate with a retardation layer, and the like.

The iodine permeation suppressing layer is a solidified product or a thermosetting product of a coating film of an organic solvent solution of a resin. In addition, the glass transition temperature (Tg) of the resin constituting the iodine permeation inhibiting layer is 85°C or higher, and the weight average molecular weight (Mw) is 25000 or higher. By providing such an iodine permeation suppressing layer at a predetermined position on the polarizing plate with a retardation layer, when the polarizing plate with a retardation layer is applied to an image display device, the iodine in the polarizer transfers to an image display device (actually an image display cell) can be significantly suppressed. As a result, corrosion of the metal members (for example, an electrode, a sensor, wiring, a metal layer) of an image display apparatus can be suppressed remarkably. Such an effect is an effect peculiar to a thin-shaped polarizing plate with a retardation layer (typically, a retardation layer is a liquid-crystal orientation solidification layer of a polarizing plate with a retardation layer). That is, the present inventors newly discovered the problem that, when a thin polarizing plate with a retardation layer is applied to an image display apparatus, the metal member of an image display apparatus may be corroded, and since iodine exists in a corrosion part, such a metal It was clarified that the corrosion of the member could be attributed to iodine. And, as a result of trial and error, as a means for preventing the transfer of iodine to an image display device (substantially an image display cell), the above iodine permeation suppressing layer (a resin having specific Tg and Mw organic solvent solution is applied) The solidified layer or thermosetting layer of a film|membrane) was found useful and came to complete this invention. That is, such an effect solves a new problem which has not been previously known, and is an unexpectedly excellent effect. In addition, as will be described later, the iodine permeation suppressing layer can be formed very thinly, and by providing the iodine permeation suppressing layer, the protective layer on the viewing side and the opposite side can be omitted. It can also contribute to further thinning of a polarizing plate with a layer.

As shown in FIG. 2 , in the polarizing plate 102 with a retardation layer according to another embodiment, another retardation layer 50 and/or an isotropic substrate 60 with a conductive layer or a conductive layer may be provided. Another retardation layer 50 is typically provided between the retardation layer 20 and the pressure-sensitive adhesive layer 30 (ie, the outer side of the retardation layer 20). The other retardation layers typically exhibit a relationship of refractive index characteristics of nz>nx=ny. The conductive layer or isotropic substrate 60 with a conductive layer is typically provided between the iodine permeation suppressing layer 40 and the pressure-sensitive adhesive layer 30 (that is, outside the iodine permeation suppressing layer 40 ). The other retardation layer 50 and the conductive layer or the isotropic substrate 60 with a conductive layer are typically provided in this order from the retardation layer 20 side. In the illustrated example, an iodine permeation suppressing layer 40, a retardation layer 20, another retardation layer 50, and an isotropic substrate 60 with a conductive layer or a conductive layer are provided in this order from the viewing side, but the other retardation layer ( 50 ) is provided between the retardation 20 and the pressure-sensitive adhesive layer 30 , and an isotropic substrate 60 with a conductive layer or a conductive layer is provided between the iodine permeation suppression layer 40 and the pressure-sensitive adhesive layer 30 . Insofar as it is so, any suitable arrangement order may be employed. The other retardation layer 50 and the conductive layer or the isotropic substrate 60 with a conductive layer are arbitrary layers typically provided as needed, and either one or both may be abbreviate|omitted. In addition, for convenience, the retardation layer 20 may be called a 1st retardation layer, and the other retardation layer 50 may be called a 2nd retardation layer. When a conductive layer or an isotropic substrate with a conductive layer is provided, a polarizing plate with a retardation layer is applied to a so-called inner touch panel type input display device in which a touch sensor is embedded between an image display cell (eg, an organic EL cell) and a polarizing plate. can In the embodiment of the present invention, by providing the conductive layer or the isotropic substrate 60 with the conductive layer on the outside of the iodine permeation suppressing layer 40, corrosion of the conductive layer can be significantly suppressed.

As described above, the first retardation layer 20 is a liquid crystal alignment solidification layer. The 1st phase difference layer 20 may be a single layer as shown in FIG. 1A, FIG. 1B, and FIG. 2, The 1st liquid crystal alignment solidification layer 21 and the 2nd liquid crystal alignment solidification layer 22 as shown in FIG. You may have a laminated structure of

The above embodiments may be appropriately combined, and modifications apparent in the art may be added to the constituent elements in the above embodiments. For example, the 2nd retardation layer 50 and/or the isotropic base material 60 with a conductive layer or a conductive layer may be provided in the polarizing plate 101 with a retardation layer of FIG. 1B; The retardation layer 20 of the polarizing plate 101 with a retardation layer of FIG. 1B may have the same two-layer structure as FIG. 3; The 2nd retardation layer 50 and/or the isotropic base material 60 with a conductive layer or a conductive layer may be provided in the polarizing plate 103 with a retardation layer of FIG. 3; The iodine permeation suppression layer 40 of the polarizing plate 102 with a retardation layer of FIG. 2 may be provided between the retardation layer 20 and the conductive layer or the isotropic base material 60 with a conductive layer.

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

The polarizing plate with a retardation layer which concerns on embodiment of this invention may be single-leaf shape, or long picture shape may be sufficient as it. In the present specification, 'long shape' means an elongate shape having a sufficiently long length with respect to the width, and includes, for example, an elongated shape having a length of 10 times or more, preferably 20 times or more with respect to the width. The elongate polarizing plate with retardation layer can be wound in roll shape.

The total thickness of the polarizing plate with a retardation layer becomes like this. Preferably it is 60 micrometers or less, More preferably, it is 55 micrometers or less, More preferably, it is 50 micrometers or less, Especially preferably, it is 40 micrometers or less. The lower limit of the total thickness may be, for example, 28 μm. According to the embodiment of the present invention, such an extremely thin polarizing plate with a retardation layer can be realized, and even when such an extremely thin polarizing plate with a retardation layer is applied to an image display device, the metal member of the image display device (for example, an electrode) , sensor, wiring, metal layer) can be significantly suppressed. In addition, such a polarizing plate with a retardation layer may have extremely excellent flexibility and bending durability. Therefore, such a polarizing plate with a retardation layer can be applied especially suitably to a curved image display apparatus and/or a bendable or foldable image display apparatus. In addition, the total thickness of the polarizing plate with a retardation layer is the sum of the thickness of the polarizing plate, the retardation layer (the first retardation layer and the second retardation layer if present), the iodine permeation suppression layer and the adhesive layer or adhesive layer for laminating them. (that is, the total thickness of the polarizing plate with a retardation layer does not include the thickness of the conductive layer or isotropic substrate 60 with a conductive layer, and the pressure-sensitive adhesive layer 30 and the release film that can be temporarily attached to the surface thereof).

Practically, it is preferable that the peeling film is temporarily attached to the surface of the adhesive layer 30 until the polarizing plate with retardation layer is provided for use. By temporarily adhering a peeling film, while protecting an adhesive layer, roll formation of a polarizing plate with retardation layer is attained.

Hereinafter, the components of a polarizing plate with a retardation layer are demonstrated in more detail. In addition, since the structure well-known in the industry may be employ|adopted for the adhesive layer 30, description is abbreviate|omitted about the detailed structure of the adhesive layer.

B. Polarizer

B-1. polarizer

The polarizer is typically composed of a polyvinyl alcohol (PVA)-based resin film containing a dichroic material. The thickness of the polarizer is preferably 1 µm to 8 µm, more preferably 1 µm to 7 µm, and still more preferably 2 µm to 5 µm. If the thickness of a polarizer is such a range, it can contribute greatly to thickness reduction of a polarizing plate with a retardation layer. Moreover, in the thin polarizing plate with retardation layer using such a polarizer, the effect of this invention is remarkable.

The boric acid content of a polarizer becomes like this. Preferably it is 10 weight% or more, More preferably, they are 13 weight% - 25 weight%. By the synergistic effect with the iodine content mentioned later that the boric acid content of a polarizer is such a range, maintaining the easiness of the curl adjustment at the time of bonding favorably, and suppressing the curl at the time of a heating favorably, at the time of heating Appearance durability can be improved. Boric acid content is computable as the amount of boric acid contained in a light polarizer per unit weight using the following formula from a neutralization method, for example.

The iodine content of the polarizer is preferably 2% by weight or more, and more preferably 2% by weight to 10% by weight. Appearance at the time of heating, maintaining easiness of the curl adjustment at the time of bonding favorably by the synergistic effect with said boric acid content as the iodine content of a polarizer being such a range, and suppressing the curl at the time of a heating favorably Durability can be improved. In this specification, "iodine content" means the amount of all iodine contained in the polarizer (PVA-based resin film). More specifically, iodine in the polarizer is iodine ion (I ^- ), iodine molecule (I ₂ ), polyiodide ion (I ₃ ^- , I ₅ ^- ) and the like, and the iodine content in the present specification means the amount of iodine including all of these forms. The iodine content can be calculated by, for example, a calibration ray method of fluorescence X-ray analysis. Moreover, polyiodine ion exists in the state which formed the PVA-iodine complex in the polarizer. By forming such a complex, absorption dichroism can be expressed in the wavelength range of visible light. Specifically, the complex of PVA and triiodide ion (PVA·I ₃ ⁻ ) has an absorption peak around 470 nm, and the complex of PVA and iodide ion (PVA·I ₅ ⁻ ) has It has an absorption peak around 600 nm. As a result, polyiodine ions, depending on their form, can absorb light in a wide range of visible light. On the other hand, the iodine ion (I ⁻ ) has an absorption peak around 230 nm and does not substantially participate in the absorption of visible light. Therefore, polyiodine ions existing in a complex state with PVA may be mainly involved in the absorption performance of the polarizer.

The polarizer preferably exhibits absorption dichroism at any wavelength of 380 nm to 780 nm. The single transmittance (Ts) of the polarizer is preferably 40% to 48%, and more preferably 41% to 46%. The polarization degree (P) of the polarizer is preferably 97.0% or more, more preferably 99.0% or more, and still more preferably 99.9% or more. The single transmittance is typically measured using an ultraviolet/visible light spectrophotometer, and is a Y value obtained by correcting visibility. The polarization degree can be obtained by the following formula based on the parallel transmittance (Tp) and the orthogonal transmittance (Tc), which are typically measured using an ultraviolet/visible light spectrophotometer and corrected for visibility.

Polarization degree (%)={(Tp-Tc)/(Tp+Tc)} ^1/2 × 100

The polarizer may be typically manufactured using a laminate of two or more layers. As a specific example of the polarizer obtained using a laminated body, the polarizer obtained using the laminated body of the resin base material and the PVA system resin layer apply|coated to the said resin base material is mentioned. A polarizer obtained by using a laminate of a resin substrate and a PVA-based resin layer coated on the resin substrate is applied, for example, by applying a PVA-based resin solution to the resin substrate and drying the resin substrate to form a PVA-based resin layer on the resin substrate. obtaining a laminate of a base material and a PVA-based resin layer; stretching and dyeing the laminate to use the PVA-based resin layer as a polarizer; Stretching typically includes stretching by immersing the laminate in an aqueous boric acid solution. In addition, the stretching may further include air stretching the laminate at a high temperature (eg, 95° C. or higher) before stretching in an aqueous boric acid solution, if necessary. The obtained laminated body of resin substrate / polarizer may be used as it is (that is, the resin substrate may be used as a protective layer of polarizer), and the resin substrate is peeled from the laminate of resin substrate / polarizer, and the said peeling surface is used for the purpose. Any suitable protective layer may be laminated and used. The detail of the manufacturing method of such a polarizer is described in Unexamined-Japanese-Patent No. 2012-73580, and Japanese Patent No. 6470455, for example. These publications are incorporated herein by reference in their entirety.

The manufacturing method of a polarizer typically forms a polyvinyl alcohol-type resin layer containing a halide and a polyvinyl alcohol-type resin on one side of an elongate thermoplastic resin base material to make a laminated body, And air|air on the said laminated body It includes performing auxiliary stretching treatment, dyeing treatment, underwater stretching treatment, and drying shrinkage treatment in this order to shrink 2% or more in the width direction by heating while conveying in the longitudinal direction. Thereby, the polarizer in which the dispersion|variation of the optical characteristic was suppressed while having an extremely thin and excellent optical characteristic can be provided. That is, even when PVA is apply|coated on a thermoplastic resin by introduce|transducing auxiliary stretching, it becomes possible to improve the crystallinity of PVA, and it becomes possible to achieve high optical characteristic. In addition, by increasing the orientation of PVA in advance at the same time, when immersed in water in a subsequent dyeing process or stretching process, problems such as a decrease in orientation and dissolution of PVA can be prevented, and high optical properties can be achieved will do In addition, in the case where the PVA-based resin layer is immersed in a liquid, as compared to the case where the PVA-based resin layer does not contain a halide, disorder in the orientation of polyvinyl alcohol molecules and a decrease in orientation can be suppressed. Thereby, the optical characteristic of the polarizer obtained through the treatment process performed by immersing a laminated body in a liquid, such as a dyeing process and an underwater extending|stretching process, can be improved. Moreover, an optical characteristic can be improved by shrinking|contracting a laminated body in the width direction by dry shrinkage process.

B-2. protective layer

The protective layer 12 is formed from any suitable film which can be used as a protective layer of a polarizer. Specific examples of the material used as the main component of the film include cellulose resins such as triacetyl cellulose (TAC), polyester, polyvinyl alcohol, polycarbonate, polyamide, polyimide, polyethersulfone, and transparent resins such as polysulfone-based, polystyrene-based, polynorbornene-based, polyolefin-based, (meth)acrylic-based and acetate-based resins. Moreover, thermosetting resins, such as (meth)acrylic type, a urethane type, a (meth)acrylic urethane type, an epoxy type, a silicone type, or ultraviolet curable resin, etc. are mentioned. In addition, for example, glassy polymers, such as a siloxane type polymer, are mentioned. Further, the polymer film described in Japanese Patent Application Laid-Open No. 2001-343529 (WO01/37007) can also be used. As a material for 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 substituted or unsubstituted phenyl group and a nitrile group in the side chain can be used, for example, isobutene and N- and a resin composition containing an alternating copolymer composed of methylmaleimide and an acrylonitrile/styrene copolymer. The polymer film may be, for example, an extrusion molding of the resin composition.

The polarizing plate with a retardation layer is typically arrange|positioned on the visual recognition side of an image display apparatus so that it may mention later, and the protective layer 12 is typically arrange|positioned at the visual recognition side. Accordingly, the protective layer 12 may be subjected to a surface treatment such as a hard coat treatment, an antireflection treatment, an antistick treatment, or an antiglare treatment, if necessary. In addition/or, the protective layer 12 is subjected to a process for improving visibility when visually recognized through polarized sunglasses (typically, imparting a (other) circular polarization function, imparting an ultra-high phase difference) to the protective layer 12 if necessary. it may be By performing such a process, excellent visibility can be implement|achieved even when a display screen is visually recognized through polarization lenses, such as polarized sunglasses. Therefore, the polarizing plate with a retardation layer can be suitably applied also to the image display apparatus which can be used outdoors.

The thickness of the protective layer is preferably 10 µm to 50 µm, more preferably 10 µm to 30 µm. In addition, when the surface treatment is performed, the thickness of the outer side protective layer is the thickness including the thickness of the surface treatment layer.

C. First retardation layer

The first retardation layer 20 is a liquid crystal alignment solidification layer as described above. Since the difference between nx and ny of the retardation layer obtained by using the liquid crystal compound can be significantly increased compared to the non-liquid crystal material, the thickness of the retardation layer for obtaining a desired in-plane retardation can be significantly reduced. As a result, further thinning of the polarizing plate with a retardation layer can be implement|achieved. As used herein, the term "liquid crystal alignment-solidified layer" refers to a layer in which a liquid crystal compound is oriented in a predetermined direction in the layer and the alignment state thereof is fixed. In addition, the 'alignment-solidified layer' is a concept including an alignment-hardened layer obtained by curing a liquid crystal monomer as will be described later. In this embodiment, the rod-shaped liquid crystal compounds are typically oriented in a state aligned in the slow axis direction of the first retardation layer (homogeneous alignment).

As a liquid crystal compound, the liquid crystal compound (nematic liquid crystal) whose liquid crystal phase is a nematic phase is mentioned, for example. As such a liquid crystal compound, for example, a liquid crystal polymer or a liquid crystal monomer can be used. The liquid crystalline expression mechanism of the liquid crystal compound may be either lyotropic or thermotropic. A liquid crystal polymer and a liquid crystal monomer may be used independently, respectively, and may be combined.

When the liquid crystal compound is a liquid crystal monomer, the liquid crystal monomer is preferably a polymerizable monomer and a crosslinkable monomer. This is because the alignment state of the liquid crystal monomer can be fixed by polymerizing or crosslinking (ie curing) the liquid crystal monomer. After aligning the liquid crystal monomers, for example, by polymerizing or crosslinking the liquid crystal monomers, the alignment state can be fixed accordingly. Here, a polymer is formed by polymerization and a three-dimensional network structure is formed by crosslinking, but these are non-liquid crystalline. Accordingly, in the formed first phase difference layer, for example, transition to a liquid crystal phase, a glass phase, and a crystal phase according to a temperature change peculiar to a liquid crystal compound does not occur. As a result, the 1st retardation layer becomes a retardation layer excellent in stability which is not affected by temperature change.

The temperature range in which the liquid crystal monomer exhibits liquid crystallinity differs depending on the type thereof. Specifically, the temperature range is preferably 40°C to 120°C, more preferably 50°C to 100°C, and most preferably 60°C to 90°C.

Any suitable liquid crystal monomer may be employed as the liquid crystal monomer. For example, the polymerizable mesogenic compound described in Japanese Patent Application Publication 2002-533742 (WO00/37585), EP358208 (US5211877), EP66137 (US4388453), WO93/22397, EP0261712, DE19504224, DE4408171 and GB2280445, etc. can be used. Specific examples of such a polymerizable mesogenic compound include, for example, BASF's trade name LC242, Merck's trade name E7, and Wacker-Chem's trade name LC-Sillicon-CC3767. As the liquid crystal monomer, for example, a nematic liquid crystal monomer is preferable.

The liquid crystal alignment solidification layer performs an alignment treatment on the surface of a predetermined substrate, and applies a coating solution containing a liquid crystal compound to the surface to align the liquid crystal compound in a direction corresponding to the alignment treatment, thereby fixing the alignment state. It can be formed by In one embodiment, the substrate is any suitable resin film, and the liquid crystal alignment solidification layer formed on the substrate can be transferred to the surface of an adjacent layer (eg, a polarizer, an iodine permeation inhibiting layer).

As the alignment treatment, any appropriate alignment treatment may be employed. Specifically, a mechanical orientation process, a physical orientation process, and a chemical orientation process are mentioned. As a specific example of a mechanical orientation process, a rubbing process and an extending|stretching process are mentioned. Specific examples of the physical alignment treatment include magnetic field alignment treatment and electric field alignment treatment. As a specific example of a chemical orientation process, an oblique vapor deposition method and a photo-alignment process are mentioned. As for the processing conditions of various orientation treatments, any suitable conditions may be employed depending on the purpose.

The alignment of the liquid crystal compound is performed by treatment at a temperature that exhibits a liquid crystal phase depending on the kind of the liquid crystal compound. By performing such a temperature treatment, a liquid crystal compound takes a liquid crystal state, and the said liquid crystal compound orientates according to the orientation treatment direction of the surface of a base material.

The alignment state is fixed by cooling the liquid crystal compound aligned as described above in one embodiment. When the liquid crystal compound is a polymerizable monomer or a crosslinkable monomer, the alignment state is fixed by subjecting the liquid crystal compound aligned as described above to a polymerization treatment or a crosslinking treatment.

The specific example of a liquid crystal compound and the detail of the formation method of an alignment-solidified layer are described in Unexamined-Japanese-Patent No. 2006-163343. The disclosure of this publication is incorporated herein by reference.

In one embodiment, the first retardation layer 20 is a single layer as shown in FIGS. 1A, 1B and 2 . When the first retardation layer 20 is composed of a single layer, the thickness thereof is preferably 0.5 µm to 7 µm, more preferably 1 µm to 5 µm. By using a liquid crystal compound, the in-plane retardation equivalent to a resin film can be implement|achieved with thickness remarkably thinner than a resin film.

The first retardation layer has a circularly polarized light function or an elliptically polarized light function as described above. The first retardation layer typically exhibits a relationship of nx>ny=nz in refractive index characteristics. The first retardation layer is typically provided to impart antireflection properties to the polarizing plate, and when the first retardation layer is a single layer, it may function as a λ/4 plate. In this case, the in-plane retardation Re(550) of the first retardation layer is preferably 100 nm to 190 nm, more preferably 110 nm to 170 nm, still more preferably 130 nm to 160 nm. In addition, 'ny=nz' includes not only the case where ny and nz are completely the same, but also the case where 'ny=nz' is substantially the same. Therefore, there may be a case where ny>nz or ny<nz is not impaired in the effect of the present invention.

The Nz coefficient of the first retardation layer is preferably 0.9 to 1.5, more preferably 0.9 to 1.3. By satisfying such a relationship, when the obtained polarizing plate with a retardation layer is used for an image display apparatus, the very excellent reflection hue can be achieved.

The first retardation layer may exhibit an inverse dispersion wavelength characteristic in which the phase difference value increases according to the wavelength of the measurement light, or may exhibit a positive wavelength dispersion characteristic in which the phase difference value decreases according to the wavelength of the measurement light, and the phase difference value is the wavelength of the measurement light You may exhibit flat wavelength dispersion characteristic which hardly changes even by this. In one embodiment, the first retardation layer exhibits an inverse 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, very excellent antireflection properties can be realized.

The angle θ between the slow axis of the first retardation layer 20 and the absorption axis of the polarizer 11 is preferably 40° to 50°, more preferably 42° to 48°, still more preferably about 45°. When the angle θ is within such a range, a polarizing plate with a retardation layer having very excellent circular polarization characteristics (as a result, very excellent antireflection characteristics) can be obtained by using the first retardation layer as a λ/4 plate as described above. .

In another embodiment, the first retardation layer 20 may have a laminated structure of the first liquid crystal alignment solidified layer 21 and the second liquid crystal aligned solidified layer 22 as shown in FIG. 3 . In this case, either one of the 1st liquid-crystal orientation solidified layer 21 and the 2nd liquid-crystal orientation solidified layer 22 can function as a λ/4 plate, and the other can function as a λ/2 plate. Accordingly, the thickness of the first liquid crystal alignment solidified layer 21 and the second liquid crystal alignment solidified layer 22 can be adjusted so that a desired in-plane retardation of the λ/4 plate or the λ/2 plate can be obtained. For example, when the 1st liquid crystal alignment solidification layer 21 functions as a λ/2 plate and the second liquid crystal alignment solidification layer 22 functions as a λ/4 plate, the thickness of the first liquid crystal alignment solidification layer 21 is, for example, 2.0 µm to 3.0 µm, and the thickness of the second liquid crystal alignment-solidified layer 22 is, for example, 1.0 µm to 2.0 µm. In this case, the in-plane retardation Re(550) of the first liquid crystal alignment solidified layer is preferably 200 nm to 300 nm, more preferably 230 nm to 290 nm, and still more preferably 250 nm to 280 nm. The in-plane retardation Re (550) of the second liquid crystal alignment solidified layer is the same as described above with respect to the single layer. The angle between the slow axis of the first liquid crystal alignment-solidified layer and the absorption axis of the polarizer is preferably 10° to 20°, more preferably 12° to 18°, and still more preferably about 15°. The angle between the slow axis of the second liquid crystal alignment-solidified layer and the absorption axis of the polarizer is preferably 70° to 80°, more preferably 72° to 78°, and still more preferably about 75°. With such a configuration, it is possible to obtain a characteristic close to the ideal reverse wavelength dispersion characteristic, and as a result, an extremely excellent antireflection characteristic can be realized. The liquid crystal compound constituting the first liquid crystal alignment solidified layer and the second liquid crystal alignment solidified layer, the method of forming the first liquid crystal alignment solidified layer and the second liquid crystal alignment solidified layer, optical properties, etc. are as described above with respect to the single layer.

D. Iodine Permeation Inhibiting Layer

The iodine permeation suppressing layer is a solidified product or a thermosetting product of a coating film of an organic solvent solution of a resin as described above. With such a structure, the thickness can be made very thin (for example, 10 µm or less). The thickness of the iodine permeation inhibiting layer is preferably 0.05 µm to 10 µm, more preferably 0.08 µm to 5 µm, still more preferably 0.1 µm to 1 µm, and particularly preferably 0.2 µm to 0.7 µm. . In addition, with such a configuration, the iodine permeation inhibiting layer can be formed directly on the adjacent layer (eg, polarizer, retardation layer) (ie, without interposing an adhesive layer or an adhesive layer). According to the embodiment of the present invention, since the polarizer, the retardation layer and the iodine permeation suppressing layer are very thin as described above, and the adhesive layer or the pressure-sensitive adhesive layer for laminating the iodine permeation suppressing layer can be omitted, the polarizing plate with a retardation layer The total thickness can be extremely thin. In addition, such an iodine permeation inhibiting layer has an advantage in that it is excellent in humidification durability because it has low hygroscopicity and moisture permeability compared to a solidified product of an aqueous coating film such as an aqueous solution or an aqueous dispersion. As a result, it is possible to realize a polarizing plate with a retardation layer excellent in durability that can maintain optical properties even in a high-temperature, high-humidity environment. Moreover, such an iodine permeation suppressing layer can suppress the adverse effect on the polarizing plate (polarizer) by ultraviolet irradiation compared with the hardened|cured material of an ultraviolet curable resin, for example. The iodine permeation suppressing layer is preferably a solidified product of a coating film of an organic solvent solution of a resin. The solidified material has smaller shrinkage during film molding compared to the cured product, and since it does not contain residual monomers, deterioration of the film itself is suppressed, and adverse effects on the polarizing plate (polarizer) caused by residual monomers, etc. can be suppressed. .

In addition, the glass transition temperature (Tg) of the resin constituting the iodine permeation inhibiting layer is 85°C or higher, and the weight average molecular weight (Mw) is 25000 or higher. When the Tg and Mw of the resin are in such ranges, the polarizer is very thin, due to a synergistic effect with the effect of forming the iodine permeation suppressing layer as a solid or thermosetting material of a coating film of an organic solvent solution of the resin. It is possible to remarkably suppress the migration of iodine in the image display cell. As a result, when a polarizing plate with a retardation layer is applied to an image display apparatus, corrosion of a metal member can be suppressed remarkably. Tg of the said resin becomes like this. Preferably it is 90 degreeC or more, More preferably, it is 100 degreeC or more, More preferably, it is 110 degreeC or more, Especially preferably, it is 120 degreeC or more. The upper limit of Tg may be, for example, 200°C. Mw of the said resin becomes like this. Preferably it is 30000 or more, More preferably, it is 35000 or more, More preferably, it is 40000 or more. The upper limit of Mw may be, for example, 150000.

As the resin constituting the iodine permeation suppressing layer, any appropriate thermoplastic resin or thermosetting resin can be used as long as it can form a solid or thermosetting product of a coating film of an organic solvent solution and has the above Tg and Mw. . Preferably it is a thermoplastic resin. As a thermoplastic resin, an acrylic resin and an epoxy resin are mentioned, for example. You may use combining an acrylic resin and an epoxy resin. Hereinafter, representative examples of the acrylic resin and the epoxy resin that can be used for the iodine permeation inhibiting layer will be described.

The acrylic resin typically contains, as a main component, a repeating unit derived from a (meth)acrylic acid ester monomer having a linear or branched structure. In this specification, (meth)acryl means acryl and/or methacryl. The acrylic resin may contain repeating units derived from any suitable copolymerization monomer according to the purpose. As a copolymerization monomer (copolymerization monomer), a carboxy group containing monomer, a hydroxyl group containing monomer, an amide group containing monomer, an aromatic ring containing (meth)acrylate, and a heterocyclic ring containing vinyl monomer are mentioned, for example. By appropriately setting the type, number, combination, copolymerization ratio, etc. of the monomer units, an acrylic resin having the above predetermined Mw can be obtained.

<Boron-containing acrylic resin>

The acrylic resin, in one embodiment, contains more than 50 parts by weight of a (meth)acrylic monomer and more than 0 parts by weight and less than 50 parts by weight of a monomer represented by Formula (1) (hereinafter sometimes referred to as a copolymerization monomer). a copolymer obtained by polymerizing a monomer mixture (hereinafter sometimes referred to as a boron-containing acrylic resin):

(Wherein, X is at least 1 selected from the group consisting of a vinyl group, a (meth)acryl group, a styryl group, a (meth)acrylamide group, a vinyl ether group, an epoxy group, an oxetane group, a hydroxyl group, an amino group, an aldehyde group, and a carboxy group represents a functional group including a reactive group of a species, and R ¹ and R ² each independently represent a hydrogen atom, an aliphatic hydrocarbon group which may have a substituent, an aryl group which may have a substituent, or a heterocyclic group which may have a substituent , R ¹ and R ² may be linked to each other to form a ring).

The boron-containing acrylic resin typically has a repeating unit represented by the following formula. By polymerizing the monomer mixture containing the copolymerized monomer represented by the formula (1) and the (meth)acrylic monomer, the boron-containing acrylic resin has a boron-containing substituent in the side chain (eg, a repeating unit of k in the following formula). Thereby, when an iodine permeation suppressing layer is arrange|positioned adjacent to a polarizer, adhesiveness with a polarizer can improve. The substituents containing boron may be continuously included in the boron-containing acrylic resin (that is, in a block shape) or may be included randomly.

(In the formula, R ⁶ represents an arbitrary functional group, and j and k represent an integer of 1 or more).

<(meth)acrylic monomer>

As the (meth)acrylic monomer, any appropriate (meth)acrylic monomer can be used. For example, the (meth)acrylic acid ester-type monomer which has a linear or branched structure, and the (meth)acrylic acid ester-type monomer which has a cyclic structure are mentioned.

Examples of the (meth)acrylic acid ester monomer having a linear or branched structure include methyl (meth)acrylate, ethyl (meth)acrylate, (meth)acrylate n-propyl, (meth)acrylate isopropyl, (meth)acrylic acid n- butyl, (meth)acrylate isobutyl, (meth)acrylate t-butyl, (meth)acrylate methyl 2-ethylhexyl, (meth)acrylic acid 2-hydroxyethyl, etc. are mentioned. Preferably, methyl (meth)acrylate is used. Only 1 type may be used for a (meth)acrylic acid ester type monomer, and may be used in combination of 2 or more type.

As the (meth)acrylic acid ester-based monomer having a cyclic structure, for example, (meth)acrylic acid cyclohexyl, (meth)acrylic acid benzyl, (meth)acrylic acid isobornyl, (meth)acrylic acid 1-adamantyl, (meth)acrylic acid dish Clopentenyl, (meth)acrylic acid dicyclopentenyloxyethyl, (meth)acrylic acid dicyclopentanyl, biphenyl (meth)acrylate, o-biphenyloxyethyl (meth)acrylate, o-biphenyloxyethoxy Ethyl (meth) acrylate, m-biphenyloxyethyl acrylate, p-biphenyloxyethyl (meth) acrylate, o-biphenyloxy-2-hydroxypropyl (meth) acrylate, p-biphenyloxy -2-hydroxypropyl (meth) acrylate, m-biphenyloxy-2-hydroxypropyl (meth) acrylate, N- (meth) acryloyloxyethyl-o-biphenyl-carbamate, N- Biphenyl groups such as (meth)acryloyloxyethyl-p-biphenyl-carbamate, N-(meth)acryloyloxyethyl-m-biphenyl-carbamate, and o-phenylphenol glycidyl ether acrylate A containing monomer, terphenyl (meth)acrylate, o-terphenyloxyethyl (meth)acrylate, etc. are mentioned. Preferably, (meth)acrylic acid 1-adamantyl and (meth)acrylic acid dicyclopentanyl are used. By using these monomers, a polymer having a high glass transition temperature can be obtained. These monomers may be used alone or in combination of two or more.

Moreover, you may use the silsesquioxane compound which has a (meth)acryloyl group instead of the said (meth)acrylic acid ester type monomer. By using the silsesquioxane compound, an acrylic polymer having a high glass transition temperature can be obtained. It is known that a silsesquioxane compound has frame|skeleton, such as various frame|skeleton structures, for example, cage structure, ladder structure, random structure. The silsesquioxane compound may contain only 1 type of these structures, and may contain 2 or more types. As a silsesquioxane compound, only 1 type may be used and may be used in combination of 2 or more type.

As the (meth)acryloyl group-containing silsesquioxane compound, for example, MAC grade of Dong-A Synthesis Co., Ltd. SQ series, and AC grade can be used. MAC grade is a silsesquioxane compound containing a methacryloyl group, and specifically, MAC-SQ TM-100, MAC-SQ SI-20, MAC-SQ HDM etc. are mentioned, for example. AC grade is a silsesquioxane compound containing an acryloyl group, and specifically, AC-SQ TA-100, AC-SQ SI-20, etc. are mentioned, for example.

The (meth)acrylic monomer is used in excess of 50 parts by weight based on 100 parts by weight of the monomer mixture.

<Copolymerized Monomer>

As a copolymerization monomer, the monomer represented by said Formula (1) is used. By using such a copolymerization monomer, the substituent containing a boron is introduce|transduced into the side chain of the polymer obtained. Only 1 type may be used for a copolymerization monomer, and may be used in combination of 2 or more type.

Examples of the aliphatic hydrocarbon group in the formula (1) include a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent, a cyclic alkyl group having 3 to 20 carbon atoms which may have a substituent, and an alkenyl group having 2 to 20 carbon atoms. can As said aryl group, a C6-C20 phenyl group which may have a substituent, a C10-20 naphthyl group which may have a substituent, etc. are mentioned. As the heterocyclic group, a 5-membered ring or a 6-membered ring containing at least one heteroatom which may have a substituent is exemplified. In addition, R ¹ and R ² may be connected to each other to form a ring. R ¹ and R ² are preferably a hydrogen atom or a linear or branched alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom.

The reactive group included in the functional group represented by X is a vinyl group, a (meth)acryl group, a styryl group, a (meth)acrylamide group, a vinyl ether group, an epoxy group, an oxetane group, a hydroxyl group, an amino group, an aldehyde group, and a carboxy group. at least one selected from Preferably, the reactive group is a (meth)acryl group and/or a (meth)acrylamide group. By having these reactive groups, when an iodine permeation suppressing layer is arrange|positioned adjacent to a polarizer, adhesiveness with a polarizer can further improve.

In one embodiment, it is preferable that the functional group represented by X is a functional group represented by Z-Y-. Here, Z is at least one selected from the group consisting of a vinyl group, a (meth)acryl group, a styryl group, a (meth)acrylamide group, a vinyl ether group, an epoxy group, an oxetane group, a hydroxyl group, an amino group, an aldehyde group, and a carboxy group. represents a functional group including a reactive group, and Y represents a phenylene group or an alkylene group.

As a copolymerization monomer, the following compounds can be used specifically,.

The copolymerization monomer is used in an amount of more than 0 parts by weight and less than 50 parts by weight with respect to 100 parts by weight of the monomer mixture. Preferably it is 0.01 weight part or more and less than 50 weight part, More preferably, it is 0.05 weight part - 20 weight part, More preferably, it is 0.1 weight part - 10 weight part, Especially preferably, it is 0.5 weight part - 5 weight part to be.

<Acrylic resin containing lactone ring, etc.>

In another embodiment, the acrylic resin includes a repeating unit having a ring structure selected from a lactone ring unit, a glutaric anhydride unit, a glutarimide unit, a maleic anhydride unit, and a maleimide (N-substituted maleimide) unit. . As for the repeating unit which has a ring structure, only one type may be contained in the repeating unit of an acrylic resin, and two or more types may be contained.

The lactone ring unit is preferably represented by the following general formula (2):

In general formula (2), R ² , R ³ and R ⁴ each independently represents a hydrogen atom or an organic residue having 1 to 20 carbon atoms. In addition, the organic moiety may include an oxygen atom. The acrylic resin may contain only a single lactone ring unit, and may contain a plurality of lactone ring units in which R ² , R ³ and R ⁴ in the general formula (2) are different. The acrylic resin having a lactone ring unit is described in, for example, Japanese Patent Application Laid-Open No. 2008-181078, the description of which is incorporated herein by reference.

The glutarimide unit is preferably represented by the following general formula (3):

In the general formula (3), R ¹¹ and R ¹² each independently represent hydrogen or an alkyl group having 1 to 8 carbon atoms, and R ¹³ is an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, or a cycloalkyl group having 6 to 10 carbon atoms. represents an aryl group of Preferably, in the general formula (3), R ¹¹ and R ¹² are each independently hydrogen or a methyl group, and R ¹³ is hydrogen, a methyl group, a butyl group or a cyclohexyl group. More preferably, R ¹¹ is a methyl group, and R ¹² is hydrogen, and R ¹³ is is a methyl group. The acrylic resin may contain only a single glutarimide unit, and may contain a plurality of glutarimide units having different R ¹¹ , R ¹² and R ¹³ in the general formula (3). Acrylic resins having a glutarimide unit are, for example, Japanese Patent Laid-Open Nos. 2006-309033, 2006-317560, Japanese Unexamined Patent Publication No. 2006-328334, and Japanese Unexamined Patent Publication No. 2006-337491 , Japanese Patent Application Laid-Open No. 2006-337492, Japanese Patent Application Laid-Open No. 2006-337493, and Japanese Patent Application Laid-Open No. 2006-337569, the description of which is incorporated herein by reference. In addition, about the glutaric acid anhydride unit, R ¹³ in the said General formula (3) Except that the substituted nitrogen atom becomes an oxygen atom, the above description of the glutarimide unit applies.

About the maleic anhydride unit and the maleimide (N-substituted maleimide) unit, since structures are specified from a name, a specific description is abbreviate|omitted.

The content ratio of the repeating unit having a ring structure in the acrylic resin is preferably 1 mol% to 50 mol%, more preferably 10 mol% to 40 mol%, still more preferably 20 mol% to 30 mol%. . Moreover, acrylic resin contains the repeating unit derived from said (meth)acrylic-type monomer as a main repeating unit.

<Epoxy resin>

As an epoxy resin, Preferably the epoxy resin which has an aromatic ring is used. By using the epoxy resin which has an aromatic ring as an epoxy resin, when an iodine permeation suppression layer is arrange|positioned adjacent to a polarizer, adhesiveness with a polarizer can improve. Moreover, when an adhesive layer is arrange|positioned adjacent to an iodine permeation suppression layer, anchoring force of an adhesive layer can improve. As an epoxy resin which has an aromatic ring, For example, bisphenol-type epoxy resins, such as a bisphenol A epoxy resin, a bisphenol F-type epoxy resin, and a bisphenol S-type epoxy resin; Novolak-type epoxy resins, such as a phenol novolak epoxy resin, a cresol novolak epoxy resin, and a hydroxybenzaldehyde phenol novolak epoxy resin; Polyfunctional epoxy resins, such as glycidyl ether of tetrahydroxyphenylmethane, glycidyl ether of tetrahydroxybenzophenone, and epoxidized polyvinyl phenol, naphthol type epoxy resin, naphthalene type epoxy resin, biphenyl type epoxy resin and the like. Preferably, a bisphenol A type epoxy resin, a biphenyl type epoxy resin, and a bisphenol F type epoxy resin are used. An epoxy resin may use only 1 type, and may use it in combination of 2 or more type.

The iodine permeation inhibiting layer may be formed by applying an organic solvent solution of the above resin to form a coating film, and then solidifying or thermosetting the coating film. As the organic solvent, any suitable organic solvent capable of dissolving or uniformly dispersing the acrylic resin can be used. Specific examples of the organic solvent include ethyl acetate, toluene, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), cyclopentanone, and cyclohexanone. The resin concentration of the solution is preferably 3 parts by weight to 20 parts by weight with respect to 100 parts by weight of the solvent. If it is such a resin density|concentration, a uniform coating film can be formed.

The solution may be applied to any suitable substrate or may be applied to an adjacent layer (eg, a polarizer, a retardation layer). When the solution is applied to the substrate, the solidified product of the coating film formed on the substrate (iodine permeation inhibiting layer) is transferred to the adjacent layer. When the solution is applied to an adjacent layer, the protective layer is directly formed on the adjacent layer by drying (solidifying) the coating film. Preferably, the solution is applied to the adjacent layer and the protective layer is formed directly on the adjacent layer. If it is such a structure, since the adhesive bond layer or adhesive layer required for transcription|transfer can be abbreviate|omitted, the polarizing plate with a retardation layer can be made further thinner. Any suitable method can be employ|adopted as a coating method of a solution. Specific examples include a roll coat method, a spin coat method, a wire bar coat method, a dip coat method, a die coat method, a curtain coat method, a spray coat method, and a knife coat method (comma coat method, etc.).

An iodine permeation inhibiting layer can be formed by solidifying or thermosetting the coating film of the solution. The heating temperature of solidification or thermosetting becomes like this. Preferably it is 100 degrees C or less, More preferably, it is 50 degreeC - 70 degreeC. If heating temperature is such a range, the bad influence to a polarizer can be prevented. The heating time may vary depending on the heating temperature. The heating time may be, for example, 1 minute to 10 minutes.

The iodine permeation inhibiting layer (substantially an organic solvent solution of the resin) may contain any suitable additive depending on the purpose. Specific examples of the additive include a UV absorber; leveling agent; antioxidants such as hindered phenols, phosphorus and sulfur; Stabilizers, such as a light stabilizer, a weathering stabilizer, and a heat stabilizer; Reinforcing materials, such as glass fiber and carbon fiber; near infrared absorbers; flame retardants such as tris (dibromopropyl) phosphate, triallyl phosphate, and antimony oxide; antistatic agents such as anionic, cationic, and nonionic surfactants; colorants such as inorganic pigments, organic pigments, and dyes; organic or inorganic fillers; resin modifiers; organic or inorganic fillers; plasticizer; lubricant; antistatic agent; flame retardant; and the like. The type, number, combination, addition amount, and the like of the additives may be appropriately set according to the purpose.

E. Second retardation layer

As described above, the second retardation layer may be a so-called positive C plate having a refractive index characteristic of nz>nx=ny. By using the positive C plate as the second retardation layer, reflection in the oblique direction can be prevented favorably, and the wide viewing angle of the antireflection function can be increased. In this case, the retardation Rth (550) in the thickness direction of the second retardation layer is preferably -50 nm to -300 nm, more preferably -70 nm to -250 nm, further preferably -90 nm to -200 nm, particularly preferably -100nm to -180nm. Here, 'nx=ny' includes not only the case where nx and ny are strictly the same, but also the case where nx and ny are substantially the same. That is, the in-plane retardation Re (550) of the second retardation layer may be less than 10 nm.

The second retardation layer having a refractive index characteristic of nz>nx=ny may be formed of any suitable material. The second retardation layer preferably comprises a film comprising a liquid crystal material fixed in homeotropic orientation. The liquid crystal material (liquid crystal compound) capable of homeotropic alignment may be a liquid crystal monomer or a liquid crystal polymer. Specific examples of the liquid crystal compound and the method for forming the retardation layer include the liquid crystal compound described in [0020] to [0028] of Japanese Patent Application Laid-Open No. 2002-333642 and the method for forming the retardation layer. In this case, the thickness of the second retardation layer is preferably 0.5 µm to 10 µm, more preferably 0.5 µm to 8 µm, and still more preferably 0.5 µm to 5 µm.

F. Conductive layer or isotropic substrate with conductive layer

The conductive layer may be formed by depositing a metal oxide film on any suitable substrate by any suitable film forming method (eg, vacuum deposition, sputtering, CVD, ion plating, spraying, etc.). Examples of the metal oxide include indium oxide, tin oxide, zinc oxide, indium-tin composite oxide, tin-antimony composite oxide, zinc-aluminum composite oxide, and indium-zinc composite oxide. Among them, indium-tin composite oxide (ITO) is preferable.

When a conductive layer contains a metal oxide, the thickness of this conductive layer becomes like this. Preferably it is 50 nm or less, More preferably, it is 35 nm or less. The lower limit of the thickness of the conductive layer is preferably 10 nm.

The conductive layer may be transferred from the substrate to the first retardation layer (or the iodine permeation suppressing layer or the second retardation layer if present), and the conductive layer alone may be a constituent layer of a polarizing plate with a retardation layer, or laminated with the substrate As a sieve (substrate with a conductive layer), it may be laminated on the first retardation layer (or the iodine permeation suppressing layer or the second retardation layer if present). Preferably, the substrate is optically isotropic, so that the conductive layer can be used as an isotropic substrate with a conductive layer in a polarizing plate with a retardation layer.

As the optically isotropic substrate (isotropic substrate), any suitable isotropic substrate can be employed. As a material constituting the isotropic substrate, for example, a material having a main skeleton of a resin without a conjugated system such as a norbornene-based resin or an olefin-based resin, or having a cyclic structure such as a lactone ring or a glutarimide ring in the main chain of the acrylic resin materials, and the like. When such a material is used, when an isotropic base material is formed, expression of the phase difference accompanying the orientation of a molecular chain can be suppressed small. The thickness of the isotropic substrate is preferably 50 µm or less, and more preferably 35 µm or less. The lower limit of the thickness of the isotropic substrate is, for example, 20 µm.

The conductive layer and/or the conductive layer of the isotropic substrate with the conductive layer may be patterned as necessary. By patterning, a conductive portion and an insulating portion may be formed. As a result, an electrode can be formed. The electrode may function as a touch sensor electrode that senses a contact to the touch panel. Any suitable method can be employ|adopted as a patterning method. Specific examples of the patterning method include a wet etching method and a screen printing method.

G. Image display device

The polarizing plate with a retardation layer as described in item A to F above can be applied to an image display apparatus. Accordingly, an embodiment of the present invention includes an image display device using such a polarizing plate with a retardation layer. A liquid crystal display device and an electroluminescent (EL) display device (for example, organic electroluminescent display apparatus, inorganic electroluminescent display apparatus) are mentioned as a representative example of an image display apparatus. The image display apparatus which concerns on embodiment of this invention equips the visual recognition side with the said polarizing plate with a retardation layer as described in the said A to F terms. The polarizing plate with a retardation layer is laminated|stacked so that a retardation layer may become an image display cell (for example, a liquid crystal cell, an organic electroluminescent cell, an inorganic EL cell) side (a polarizer may become a visual recognition side). Although such an image display apparatus is very thin, corrosion of a metal member is suppressed remarkably. In one embodiment, the image display device has a curved shape (substantially curved display screen) and/or is bendable or foldable.

[Example]

Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited by these Examples. The measuring method of each characteristic is as follows. In addition, unless otherwise specified, 'part' and '%' in Examples and Comparative Examples are based on weight.

(1) thickness

The thickness of 10 µm or less was measured using an interference film thickness measuring instrument (manufactured by Otsuka Electronics, product name 'MCPD-3000'). The thickness exceeding 10 μm was measured using a digital micrometer (manufactured by Anritsu Corporation, product name 'KC-351C').

(2) Corrosive to metal (48 hours)

On one side of a 50 µm polyethylene terephthalate (PET) film, silver nanowire solution (manufactured by MERCK), nanowire size: 115 nm in diameter, 20 µm to 50 µm in length, isopropyl alcohol (IPA) having a solid content of 0.5% solution) was coated with a wire bar to a wet film thickness of 15 µm, and dried in an oven at 100° C. for 5 minutes to form a silver nanowire coating film. Subsequently, an overcoat liquid containing 99 parts of methyl isobutyl ketone (MIBK), 1 part of pentaerythritol tetraacrylate (PETA), and 0.03 parts of a photopolymerization initiator (manufactured by BASF, product name 'Irgacure 907') (Solid content concentration: about 1%) was coated on the surface of the silver nanowire coating film using a wire bar so that the wet film thickness was 10 µm, and dried in an oven at 100°C for 5 minutes. Next, the overcoat coating film was hardened by irradiating an active energy ray, and the metal film which has a structure of PET film/silver nanowire layer/overcoat layer (thickness 100 nm) was produced. This metal film was bonded to a 0.5 mm-thick glass plate using an adhesive (15 micrometers), and the laminated body of a metal film/adhesive agent/glass plate was obtained. When the resistance value of the obtained laminate was measured with a non-contact resistance measuring device (manufactured by Napson Corporation, product name 'EC-80'), it was 50 Ω/□.

The polarizing plate with retardation layer obtained by the Example and the comparative example was pasted together on the overcoat layer surface of the metal film of a laminated body, and it was set as the test sample. The resistance value of this test sample was measured with a non-contact resistance measuring device, and it was set as the initial resistance value. In addition, after subjecting the test sample to a reliability test (standing for 48 hours in an environment of 85°C/85% RH, and then leaving it for 2 hours in an environment of 23°C/55% RH), the resistance value is measured in the same manner as above. did. The resistance value increase rate was computed with the following formula|equation. In addition, when the measured value (resistance value) exceeded the measurement limit (1000 ohm/square) of a non-contact type resistance measuring instrument, it was assumed that the measured value was 1500 ohms/square.

Resistance value increase rate (%) = {(resistance value after reliability test-initial resistance value)/initial resistance value} x 100

In addition, the following criteria evaluated.

Good: resistance value increase rate is less than 200%

Poor: resistance value increase rate of 200% or more

(3) Metal corrosion (200 hours)

The polarizing plate with retardation layer obtained by the Example and the comparative example was bonded together on the overcoat layer formation surface of the metal film of the laminated body obtained by (2), and it was set as the test sample. The resistance value of this test sample was measured with a non-contact resistance measuring device, and it was set as the initial resistance value. In addition, after subjecting the test sample to a reliability test (standing for 200 hours in an environment of 85°C/85% RH, and then leaving it for 2 hours in an environment of 23°C/55% RH), the resistance value is measured in the same manner as above. did. The resistance value increase rate was computed with the following formula|equation. In addition, when the measured value (resistance value) exceeded the measurement limit (1000 ohm/square) of a non-contact type resistance measuring instrument, it was assumed that the measured value was 1500 ohms/square.

Resistance value increase rate (%) = {(resistance value after reliability test-initial resistance value)/initial resistance value} x 100

In addition, the following criteria evaluated.

Excellent: resistance value increase rate is less than 200%

Good: resistance value increase rate of 200% or more and less than 2000%

Poor: resistance value increase rate of 2000% or more

[Example 1]

1. Fabrication of polarizer

As a thermoplastic resin substrate, an amorphous isophthalic copolymerized polyethylene terephthalate film (thickness: 100 µm) having a long water absorption rate of 0.75% and a Tg of about 75°C was used. Corona treatment was performed on one side of the resin substrate.

Polyvinyl alcohol (polymerization degree 4200, saponification degree 99.2 mol%) and acetoacetyl-modified PVA (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name 'Gosewaimer Z410') in a ratio of 9: 1 to 100 parts by weight of a PVA-based resin mixed with potassium iodide 13 parts by weight was added and dissolved in water to prepare a PVA aqueous solution (coating solution).

By apply|coating the said PVA aqueous solution to the corona-treated surface of a resin base material, and drying at 60 degreeC, the PVA-type resin layer of thickness 13 micrometers was formed, and the laminated body was produced.

The obtained laminate was uniaxially stretched at the free end by 2.4 times in the longitudinal direction (longitudinal direction) between rolls having different circumferential speeds in an oven at 130°C (air-assisted stretching treatment).

Next, the laminate was immersed in an insolubilization bath (a boric acid aqueous solution obtained by blending 4 parts by weight of boric acid with respect to 100 parts by weight of water) at a liquid temperature of 40°C for 30 seconds (insolubilization treatment).

Next, in a dyeing bath (aqueous solution of iodine obtained by mixing iodine and potassium iodide in a weight ratio of 1:7 with respect to 100 parts by weight of water) at a liquid temperature of 30°C, the single transmittance (Ts) of the finally obtained polarizer is 43.0% or more It was immersed for 60 seconds while adjusting the concentration so as to be this (dyeing treatment).

Then, it was immersed in a crosslinking bath (a boric acid aqueous solution obtained by blending 3 parts by weight of potassium iodide with respect to 100 parts by weight of water and 5 parts by weight of boric acid) with a liquid temperature of 40°C for 30 seconds (crosslinking treatment).

Thereafter, while the laminate is immersed in an aqueous boric acid solution (boric acid concentration: 4.0 wt%, potassium iodide: 5 wt%) at a liquid temperature of 70 ° C. Uniaxial stretching was performed as much as possible (underwater stretching treatment).

Thereafter, the laminate was immersed in a washing bath (aqueous solution obtained by blending 4 parts by weight of potassium iodide with respect to 100 parts by weight of water) having a liquid temperature of 20°C (washing treatment).

Thereafter, while drying in an oven maintained at 90°C, it was brought into contact with a heating roll made of SUS whose surface temperature was maintained at 75°C for about 2 seconds (dry shrinkage treatment). The shrinkage ratio in the width direction of the laminate by the drying shrinkage treatment was 5.2%.

In this way, a polarizer having a thickness of 5 µm was formed on the resin substrate.

2. Fabrication of polarizing plate

On the surface (surface on the side opposite to the resin base material) of the polarizer obtained above, the HC-COP film was bonded together through the ultraviolet curing adhesive as a protective layer. Specifically, it coated so that the total thickness of a curable adhesive might be set to 1.0 micrometer, and it bonded together using the roll machine. Thereafter, UV rays were irradiated from the protective layer side to cure the adhesive. In addition, the HC-COP film is a film in which a hard coat (HC) layer (thickness 2 µm) is formed on a cycloolefin (COP) film (manufactured by Nippon Zeon, product name 'ZF12', thickness 25 µm), and the COP film is a polarizer It was made to become a side, and it bonded together. Next, the resin base material was peeled, and the polarizing plate which has the structure of protective layer (HC layer/COP film)/adhesive layer/polarizer was obtained.

3. Preparation of the first alignment-solidified layer and the second alignment-solidified layer constituting the retardation layer

10 g of a polymerizable liquid crystal exhibiting a nematic liquid crystal phase (manufactured by BASF: trade name 'Paliocolor LC242', represented by the following formula) and a photopolymerization initiator for the polymerizable liquid crystal compound (manufactured by BASF: trade name ' 3 g of Irgacure 907') was dissolved in 40 g of toluene to prepare a liquid crystal composition (coating solution).

The surface of a polyethylene terephthalate (PET) film (thickness 38 µm) was rubbed using a rubbing cloth, followed by orientation treatment. The direction of orientation treatment was made so that it might become a 15 degree direction as seen from the visual recognition side with respect to the direction of the absorption axis of a polarizer when bonding to a polarizing plate. The liquid crystal compound was orientated by coating the said liquid crystal coating liquid on the surface of this orientation treatment with a bar coater, and heat-drying at 90 degreeC for 2 minute(s). Thus, the liquid crystal layer formed was irradiated with light of 1 mJ/cm< ² > using a metal halide lamp, and the liquid-crystal orientation solidification layer A was formed on PET film by hardening the said liquid-crystal layer. The thickness of the liquid-crystal alignment solidification layer A was 2.5 micrometers, and in-plane retardation Re(550) was 270 nm. Moreover, the liquid-crystal orientation solidification layer A had refractive index distribution of nx>ny=nz.

A liquid-crystal alignment solidification layer B was formed on the PET film in the same manner as above except that the coating thickness was changed and the orientation treatment direction was set to be 75° when viewed from the visual side with respect to the direction of the absorption axis of the polarizer. The thickness of the liquid-crystal alignment solidification layer B was 1.5 micrometers, and the in-plane retardation Re(550) was 140 nm. Moreover, the liquid-crystal orientation solidification layer B had refractive index distribution of nx>ny=nz.

4. Formation of retardation layer

On the polarizer surface of the polarizing plate obtained in said 2., the liquid-crystal orientation solidified layer A and the liquid-crystal orientation solidified layer B obtained in said 3. were transcribe|transferred in this order. At this time, the angle between the absorption axis of the polarizer and the slow axis of the liquid crystal alignment and solidification layer A is 15°, and the angle between the absorption axis of the polarizer and the slow axis of the liquid crystal alignment and solidification layer B is 75°, and transfer (bonding) is performed. was done. In addition, each transcription|transfer (bonding) was performed through the ultraviolet curing adhesive agent (1.0 micrometer in thickness) used in said 2. In this way, a laminate having the configuration of a protective layer (HC layer/COP film)/adhesive layer/polarizer/adhesive layer/retardation layer (first liquid crystal alignment solidified layer/adhesive layer/second liquid crystal alignment solidified layer) was produced did.

5. Preparation of polarizing plate with retardation layer

20 parts of acrylic resin (made by Kusumoto Chemical Co., Ltd., product name 'B-811', Tg: 110 degreeC, Mw: 40000) was melt|dissolved in 80 parts of methyl ethyl ketone, and the resin solution (20%) was obtained. This resin solution is applied to the surface of the second liquid crystal alignment solidified layer of the laminate obtained in 4. above using a wire bar, and the coating film is dried at 60° C. for 5 minutes, which is constituted as a solidified product of the coating film of the organic solvent solution of the resin. An iodine permeation inhibiting layer (thickness: 0.5 µm) was formed. Next, an adhesive layer (thickness 15 µm) is provided on the surface of the iodine permeation suppression layer, and protective layer (HC layer/COP film)/adhesive layer/polarizer/adhesive layer/retardation layer (first liquid crystal alignment solidified layer/adhesive layer/ The polarizing plate with retardation layer which has the structure of 2nd liquid-crystal orientation solidification layer) / iodine permeation|transmission suppression layer / adhesive layer was obtained. The total thickness of the obtained polarizing plate with retardation layer was 39.5 micrometers. The obtained polarizing plate with retardation layer was used for evaluation of said (2) and (3). In addition, with respect to metal corrosion, it was compared with Comparative Example 1 (described later) in which an iodine permeation inhibiting layer was not formed. A result is shown in Table 1 and Table 2.

[Example 2]

97.0 parts of methyl methacrylate (MMA, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd., trade name 'methyl methacrylate monomer'), 3.0 parts of the copolymerization monomer represented by the general formula (1e), a polymerization initiator (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., 0.2 parts of trade name '2,2'-azobis(isobutyronitrile)') were dissolved in 200 parts of toluene. Then, the polymerization reaction was performed for 5.5 hours while heating to 70 degreeC in nitrogen atmosphere, and the boron containing acrylic resin solution (solid content concentration: 33%) was obtained. Tg of the obtained boron-containing acrylic polymer was 110 degreeC, and Mw was 80000. A polarizing plate with a retardation layer was produced in the same manner as in Example 1, except that this boron-containing acrylic polymer was used instead of the acrylic resin 'B-811' and the thickness of the iodine permeation suppressing layer was set to 0.3 µm. The obtained polarizing plate with retardation layer was used for evaluation similar to Example 1. A result is shown in Table 1 and Table 2.

[Example 3]

A polarizing plate with a retardation layer was produced in the same manner as in Example 2 except that the thickness of the iodine permeation suppressing layer was set to 0.5 µm. The obtained polarizing plate with retardation layer was used for evaluation similar to Example 1. A result is shown in Table 1 and Table 2.

[Example 4]

A polarizing plate with retardation layer was carried out in the same manner as in Example 1 except that a thermoplastic epoxy resin (manufactured by Mitsubishi Chemical Co., Ltd., trade name 'jER (registered trademark) 1256B40', Tg: 100°C, Mw: 45000) was used instead of the acrylic resin 'B-811' was produced. The obtained polarizing plate with retardation layer was used for evaluation similar to Example 1. A result is shown in Table 1 and Table 2.

[Example 5]

A thermoplastic epoxy resin (manufactured by Mitsubishi Chemical Co., Ltd., trade name 'jER (registered trademark) YX7200B35', Tg: 150°C, Mw: 30000) was used instead of the acrylic resin 'B-811', and the thickness of the iodine permeation inhibiting layer was 0.3 µm Except having set it as Example 1, it carried out similarly to Example 1, and produced the polarizing plate with retardation layer. The obtained polarizing plate with retardation layer was used for evaluation similar to Example 1. A result is shown in Table 1 and Table 2.

[Example 6]

A polarizing plate with a retardation layer was produced in the same manner as in Example 5 except that the thickness of the iodine permeation suppressing layer was set to 0.5 µm. The obtained polarizing plate with retardation layer was used for evaluation similar to Example 1. A result is shown in Table 1 and Table 2.

[Example 7]

Example 1 except for using a blend of 15 parts of 'B-811' instead of acrylic resin 'B-811' and 85 parts (in terms of solid content) of a thermoplastic epoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name 'jER (registered trademark) YX6954BH30') It carried out similarly, and produced the polarizing plate with retardation layer. The blend had a Tg of 125° C. and a Mw of 38000. The obtained polarizing plate with retardation layer was used for evaluation similar to Example 1. A result is shown in Table 1 and Table 2.

[Example 8]

The resin blend used in Example 7 was applied and dried on the polarizer side of the polarizing plate having the configuration of a protective layer (HC layer/COP film)/adhesive layer/polarizer obtained in Example 1 2., and an organic solvent solution of the resin An iodine permeation suppressing layer (thickness of 0.5 µm) constituted as a solidified product of the coating film was formed. On the surface of the iodine permeation suppression layer, in the same manner as in Example 1, the liquid crystal alignment solidified layer A and the liquid crystal alignment solidified layer B were transferred in this order, and protective layer (HC layer/COP film)/adhesive layer/polarizer/iodine permeation suppression layer A polarizing plate with a retardation layer having a structure of /adhesive layer/retardation layer (1st liquid-crystal orientation-solidified layer)/adhesive layer/2nd liquid-crystal orientation-solidified layer)/adhesive layer was obtained. The obtained polarizing plate with retardation layer was used for evaluation similar to Example 1. A result is shown in Table 1 and Table 2.

[Example 9]

A laminate having the configuration of a protective layer (HC layer/COP film)/adhesive layer/polarizer/iodine permeation suppressing layer was prepared in the same manner as in Example 8 except that the boron-containing acrylic polymer in Example 2 was used. Next, as in Example 1, except that 15 parts of the boron-containing acrylic polymer in Example 2 and 85 parts (in terms of solid content) of a thermoplastic epoxy resin (manufactured by Mitsubishi Chemical Co., Ltd., trade name 'jER (registered trademark) YX6954BH30') were used as a blend. Thus, protective layer (HC layer / COP film) / adhesive layer / polarizer / iodine permeation suppression layer / adhesive layer / retardation layer (first liquid crystal alignment solidified layer / adhesive layer / second liquid crystal alignment solidified layer) / iodine permeation suppressing layer / The polarizing plate with retardation layer which has the structure of an adhesive layer was obtained. The total thickness of the obtained polarizing plate with retardation layer was 40 micrometers. The obtained polarizing plate with retardation layer was used for evaluation similar to Example 1. A result is shown in Table 2.

[Example 10]

Between the polarizer and the retardation layer, 15 parts of the boron-containing acrylic polymer obtained in Example 2 and a thermoplastic epoxy resin (manufactured by Mitsubishi Chemical Co., Ltd., trade name 'jER (registered trademark) YX6954BH30 ') Except having used the blend with 85 parts (solid content conversion), it carried out similarly to Example 9, and obtained the polarizing plate with retardation layer. The total thickness of the obtained polarizing plate with retardation layer was 40 micrometers. The obtained polarizing plate with retardation layer was used for evaluation similar to Example 1. A result is shown in Table 2.

[Example 11]

The protective layer ( HC layer/COP film)/adhesive layer/polarizer/adhesive layer/iodine permeation suppressing layer/retardation layer (first liquid crystal alignment solidified layer/adhesive layer/second liquid crystal alignment solidified layer)/iodine permeation suppressing layer/adhesive layer A polarizing plate with a retardation layer having The total thickness of the obtained polarizing plate with retardation layer was 40 micrometers. The obtained polarizing plate with retardation layer was used for evaluation similar to Example 1. A result is shown in Table 2.

[Example 12]

As in Example 9, between the polarizer and the retardation layer, except that an iodine permeation suppressing layer was further formed at a position adjacent to the polarizer, in the same manner as in Example 11, protective layer (HC layer/COP film)/adhesive layer/ Polarizer / iodine permeation suppressing layer / adhesive layer / iodine permeation suppressing layer / retardation layer (first liquid crystal alignment solidified layer / adhesive layer / second liquid crystal alignment solidified layer) / iodine permeation suppressing layer / with a retardation layer having the structure of an adhesive layer A polarizing plate was obtained. The total thickness of the obtained polarizing plate with retardation layer was 40.5 micrometers. The obtained polarizing plate with retardation layer was used for evaluation similar to Example 1. A result is shown in Table 2.

[Comparative Example 1]

Except not having formed the iodine permeation suppression layer, it carried out similarly to Example 1, and produced the polarizing plate with a retardation layer. The obtained polarizing plate with retardation layer was used for evaluation similar to Example 1. A result is shown in Table 1 and Table 2.

[Comparative Example 2]

A polarizing plate with a retardation layer was produced in the same manner as in Example 1 except that acrylic resin 'B-723' (manufactured by Kusumoto Chemical Co., Ltd., Tg: 54°C, Mw: 200000) was used instead of acrylic resin 'B-811'. The obtained polarizing plate with retardation layer was used for evaluation similar to Example 1. A result is shown in Table 1 and Table 2.

[Comparative Example 3]

In the same manner as in Example 1, except that a photocurable epoxy resin (manufactured by Mitsubishi Chemical Co., Ltd., trade name 'jER (registered trademark) 828', and 'CPI100P' manufactured by San Afro Co., Ltd. was used as a photopolymerization initiator) instead of the acrylic resin 'B-811' Thus, a polarizing plate with a retardation layer was produced. The obtained polarizing plate with retardation layer was used for evaluation similar to Example 1. A result is shown in Table 1 and Table 2.

[Comparative Example 4]

A polarizing plate with a retardation layer was prepared in the same manner as in Example 1 except that a PVA-based resin (manufactured by Mitsubishi Chemical Co., Ltd., trade name 'Gosenol Z200', Tg: 80°C, Mw: 8800) was used instead of the acrylic resin 'B-811' . The obtained polarizing plate with retardation layer was used for evaluation similar to Example 1. A result is shown in Table 1 and Table 2.

[Reference Example 1]

1. Fabrication of polarizing plate

It carried out similarly to Example 1, and obtained the polarizing plate which has the structure of protective layer (HC layer/COP film)/polarizer.

2. Preparation of retardation film constituting retardation layer

2-1. Polymerization of polyester carbonate-based resins

Polymerization was carried out using a batch polymerization apparatus consisting of two vertical reactors equipped with stirring blades and a reflux condenser controlled at 100°C. Bis[9-(2-phenoxycarbonylethyl)fluoren-9-yl]methane 29.60 parts by mass (0.046 mol), isosorbide (ISB) 29.21 parts by mass (0.200 mol), spiroglycol (SPG) 42.28 mass Parts (0.139 mol), 63.77 parts by mass (0.298 mol) of diphenyl carbonate (DPC), and 1.19×10 ^-2 parts by mass (6.78×10 ^-5 mol) of calcium acetate monohydrate as a catalyst were added. After replacing the inside of the reactor with reduced pressure nitrogen, heating was performed with a heat medium, and stirring was started when the internal temperature reached 100°C. The internal temperature was made to reach 220 degreeC 40 minutes after the start of temperature increase, and while controlling so that this temperature might be maintained, pressure reduction was started, and it was set to 13.3 kPa in 90 minutes after reaching 220 degreeC. The phenol vapor produced by the polymerization reaction was led to a reflux condenser at 100° C., the monomer component contained in a small amount in the phenol vapor was returned to the reactor, and the uncondensed phenol vapor was led to the condenser at 45° C. and recovered. After nitrogen was introduced into the first reactor and the pressure was returned to atmospheric pressure, the oligomerized reaction solution in the first reactor was transferred to the second reactor. Then, the temperature rise and pressure reduction in the 2nd reactor were started, and it was set as the internal temperature of 240 degreeC and the pressure of 0.2 kPa in 50 minutes. Thereafter, polymerization was allowed to proceed until a predetermined stirring power was reached. At the time when a predetermined power was reached, nitrogen was introduced into the reactor and the pressure was restored, the resulting polyester carbonate-based resin was extruded into water, and the strands were cut to obtain pellets.

2-2. Production of retardation film

After vacuum drying the obtained polyester carbonate-based resin (pellet) at 80 ° C. for 5 hours, a single screw extruder (manufactured by Toshiba Machinery Co., Ltd., cylinder set temperature: 250 ° C.), T-die (width 200 mm, set temperature: 250 ° C.), A 135-micrometer-thick long resin film was produced using the film film forming apparatus provided with the chilled roll (setting temperature: 120-130 degreeC) and the winder. The obtained elongate resin film was extended|stretched by the extending|stretching temperature of 133 degreeC, and a draw ratio of 2.8 times in the width direction, and the 53-micrometer-thick retardation film was obtained. Re(550) of the obtained retardation film was 141 nm, Re(450)/Re(550) was 0.82, and Nz coefficient was 1.12.

3. Preparation of polarizing plate with retardation layer

On the polarizer surface of the polarizing plate obtained in said 1., the retardation film obtained in said 2. was bonded through the acrylic adhesive (5 micrometers in thickness). At this time, it bonded together so that the absorption axis of a polarizer and the slow axis of retardation film might make the angle of 45 degrees. Moreover, the adhesive layer similar to Example 1 was provided on the surface of the retardation layer. In this way, the polarizing plate with retardation layer which has the structure of protective layer / adhesive agent layer / polarizer / adhesive layer / retardation layer (stretched film of a resin film) / adhesive layer was obtained. The total thickness of the obtained polarizing plate with retardation layer was 91 micrometers. The obtained polarizing plate with retardation layer was used for evaluation similar to Example 1. A result is shown in Table 1 and Table 2.

[Table 1]

[Table 2]

[evaluation]

As is clear from Table 1, the polarizing plate with a retardation layer of the embodiment of the present invention forms an iodine permeation suppressing layer composed of a solidified product of a coating product of an organic solvent solution of a resin having predetermined Tg and Mw, thereby forming a metal under a high temperature and high humidity environment. Corrosion can be significantly suppressed. Therefore, it turns out that the polarizing plate with a retardation layer of the Example of this invention can suppress corrosion of a metal member, when it applies to an image display apparatus. Moreover, it turns out that such a metal corrosion property is a subject peculiar to a very thin polarizing plate with retardation layer evidently from Reference Example 1.

As is clear from Table 2, the polarizing plates with retardation layer of Examples 9 to 12 of the present invention contain two or three layers of iodine permeation suppression layers, so that even when put in for a long time (200 hours) in a high-temperature, high-humidity environment, metal corrosion is remarkable. can be suppressed. Therefore, when the polarizing plate with retardation layer of Examples 9-12 of this invention is applied to an image display apparatus, it turns out that corrosion of a metal member can be suppressed remarkably.

[Industrial Applicability]

The polarizing plate with a retardation layer of this invention is used suitably as a circular polarizing plate for liquid crystal display devices, organic electroluminescent display devices, and inorganic electroluminescent display devices.

10: polarizer
11: Polarizer
12: protective layer
20: retardation layer
30: adhesive layer
40: iodine permeation inhibiting layer
100: polarizing plate with retardation layer
101: polarizing plate with retardation layer
102: polarizing plate with retardation layer
103: polarizing plate with retardation layer
104: polarizing plate with retardation layer
105: polarizing plate with retardation layer

Claims (14)

A polarizing plate including a polarizer, a retardation layer and an adhesive layer are included in this order from the viewer side,
The retardation layer is an alignment-solidified layer of a liquid crystal compound having a circular polarization function or an elliptically polarization function,
An iodine permeation inhibiting layer is provided between the polarizer and the pressure-sensitive adhesive layer, which is a solid or thermosetting product of a coating film of a solution,
The glass transition temperature of the resin constituting the iodine permeation inhibiting layer is 85 ℃ or more, and the weight average molecular weight (Mw) is 25000 or more,
Polarizing plate with retardation layer. According to claim 1,
A polarizing plate with a retardation layer, wherein the iodine permeation suppressing layer is provided between the polarizer and the retardation layer. According to claim 1,
The polarizing plate with a retardation layer in which the said iodine permeation suppressing layer is provided between the said retardation layer and the said adhesive layer. According to claim 1,
The polarizing plate with a retardation layer in which the said iodine permeation suppression layer is provided in two or more layers between the said polarizer and the said adhesive layer. 5. The method according to any one of claims 1 to 4,
The thickness of the said iodine permeation suppression layer is 0.05-10 micrometers, The polarizing plate with retardation layer. 6. The method according to any one of claims 1 to 5,
A polarizing plate with a retardation layer, wherein the glass transition temperature of the resin constituting the iodine permeation suppressing layer is 90° C. or higher. 7. The method according to any one of claims 1 to 6,
A copolymer obtained by polymerizing a monomer mixture in which the resin constituting the iodine permeation inhibiting layer contains more than 50 parts by weight of a (meth)acrylic monomer and more than 0 parts by weight and less than 50 parts by weight of a monomer represented by Formula (1) A polarizing plate with a retardation layer comprising:

In the formula, X is at least one selected from the group consisting of a vinyl group, a (meth)acryl group, a styryl group, a (meth)acrylamide group, a vinyl ether group, an epoxy group, an oxetane group, a hydroxyl group, an amino group, an aldehyde group, and a carboxy group represents a functional group including a reactive group of, R ¹ and R ² each independently represent a hydrogen atom, an aliphatic hydrocarbon group which may have a substituent, an aryl group which may have a substituent or a heterocyclic group which may have a substituent, R ¹ and R ² may be connected to each other to form a ring. 8. The method according to any one of claims 1 to 7,
The retardation layer is a single layer,
Re (550) of the retardation layer is 100 nm to 190 nm,
An angle between the slow axis of the retardation layer and the absorption axis of the polarizer is 40° to 50°,
Polarizing plate with retardation layer. 8. The method according to any one of claims 1 to 7,
The retardation layer has a laminated structure of the alignment-solidified layer of the first liquid crystal compound and the alignment-solidified layer of the second liquid crystal compound,
Re (550) of the alignment-solidified layer of the first liquid crystal compound is 200 nm to 300 nm, and an angle between its slow axis and the absorption axis of the polarizer is 10° to 20°,
Re (550) of the alignment-solidified layer of the second liquid crystal compound is 100 nm to 190 nm, and the angle between its slow axis and the absorption axis of the polarizer is 70 ° to 80 °,
Polarizing plate with retardation layer. 10. The method according to any one of claims 1 to 9,
A polarizing plate with a retardation layer, further comprising another retardation layer between the retardation layer and the pressure-sensitive adhesive layer, wherein the refractive index characteristic of the other retardation layer exhibits a relationship of nz>nx=ny. 11. The method according to any one of claims 1 to 10,
A polarizing plate with a retardation layer, further comprising an isotropic substrate with a conductive layer or a conductive layer between the iodine permeation suppression layer and the pressure-sensitive adhesive layer. 12. The method according to any one of claims 1 to 11,
A polarizing plate with a retardation layer whose total thickness is 60 micrometers or less. An image display device provided with the polarizing plate with a retardation layer in any one of Claims 1-12. 14. The method of claim 13,
The image display apparatus which is an organic electroluminescent display apparatus or an inorganic electroluminescent display apparatus.

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